[mbedTLS] Enable TLS 1.3 support

Move library initialization to module registration functions.

Only set library debug threshold when verbose output is enabled.

TLSv1.3 functions seems to be a bit more verbose then expected, and
generate a lot of noise. Yet, some level of debugging without
recompiling the engine would be nice. We should discuss this upstream.

1 files changed, 9233 insertions, 0 deletions

diff --git a/thirdparty/mbedtls/library/psa_crypto.c b/thirdparty/mbedtls/library/psa_crypto.c
new file mode 100644
index 0000000000..c4f41db10b
--- /dev/null
+++ b/thirdparty/mbedtls/library/psa_crypto.c
@@ -0,0 +1,9233 @@
+/*
+ *  PSA crypto layer on top of Mbed TLS crypto
+ */
+/*
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+
+#include "common.h"
+#include "psa_crypto_core_common.h"
+
+#if defined(MBEDTLS_PSA_CRYPTO_C)
+
+#if defined(MBEDTLS_PSA_CRYPTO_CONFIG)
+#include "check_crypto_config.h"
+#endif
+
+#include "psa/crypto.h"
+#include "psa/crypto_values.h"
+
+#include "psa_crypto_cipher.h"
+#include "psa_crypto_core.h"
+#include "psa_crypto_invasive.h"
+#include "psa_crypto_driver_wrappers.h"
+#include "psa_crypto_driver_wrappers_no_static.h"
+#include "psa_crypto_ecp.h"
+#include "psa_crypto_ffdh.h"
+#include "psa_crypto_hash.h"
+#include "psa_crypto_mac.h"
+#include "psa_crypto_rsa.h"
+#include "psa_crypto_ecp.h"
+#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
+#include "psa_crypto_se.h"
+#endif
+#include "psa_crypto_slot_management.h"
+/* Include internal declarations that are useful for implementing persistently
+ * stored keys. */
+#include "psa_crypto_storage.h"
+
+#include "psa_crypto_random_impl.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include "mbedtls/platform.h"
+
+#include "mbedtls/aes.h"
+#include "mbedtls/asn1.h"
+#include "mbedtls/asn1write.h"
+#include "mbedtls/bignum.h"
+#include "mbedtls/camellia.h"
+#include "mbedtls/chacha20.h"
+#include "mbedtls/chachapoly.h"
+#include "mbedtls/cipher.h"
+#include "mbedtls/ccm.h"
+#include "mbedtls/cmac.h"
+#include "mbedtls/constant_time.h"
+#include "mbedtls/des.h"
+#include "mbedtls/ecdh.h"
+#include "mbedtls/ecp.h"
+#include "mbedtls/entropy.h"
+#include "mbedtls/error.h"
+#include "mbedtls/gcm.h"
+#include "mbedtls/md5.h"
+#include "mbedtls/pk.h"
+#include "pk_wrap.h"
+#include "mbedtls/platform_util.h"
+#include "mbedtls/error.h"
+#include "mbedtls/ripemd160.h"
+#include "mbedtls/rsa.h"
+#include "mbedtls/sha1.h"
+#include "mbedtls/sha256.h"
+#include "mbedtls/sha512.h"
+#include "mbedtls/psa_util.h"
+#include "mbedtls/threading.h"
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF) ||          \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT) ||  \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND)
+#define BUILTIN_ALG_ANY_HKDF 1
+#endif
+
+/****************************************************************/
+/* Global data, support functions and library management */
+/****************************************************************/
+
+static int key_type_is_raw_bytes(psa_key_type_t type)
+{
+    return PSA_KEY_TYPE_IS_UNSTRUCTURED(type);
+}
+
+/* Values for psa_global_data_t::rng_state */
+#define RNG_NOT_INITIALIZED 0
+#define RNG_INITIALIZED 1
+#define RNG_SEEDED 2
+
+/* IDs for PSA crypto subsystems. Starts at 1 to catch potential uninitialized
+ * variables as arguments. */
+typedef enum {
+    PSA_CRYPTO_SUBSYSTEM_DRIVER_WRAPPERS = 1,
+    PSA_CRYPTO_SUBSYSTEM_KEY_SLOTS,
+    PSA_CRYPTO_SUBSYSTEM_RNG,
+    PSA_CRYPTO_SUBSYSTEM_TRANSACTION,
+} mbedtls_psa_crypto_subsystem;
+
+/* Initialization flags for global_data::initialized */
+#define PSA_CRYPTO_SUBSYSTEM_DRIVER_WRAPPERS_INITIALIZED    0x01
+#define PSA_CRYPTO_SUBSYSTEM_KEY_SLOTS_INITIALIZED          0x02
+#define PSA_CRYPTO_SUBSYSTEM_TRANSACTION_INITIALIZED        0x04
+
+#define PSA_CRYPTO_SUBSYSTEM_ALL_INITIALISED                ( \
+        PSA_CRYPTO_SUBSYSTEM_DRIVER_WRAPPERS_INITIALIZED | \
+        PSA_CRYPTO_SUBSYSTEM_KEY_SLOTS_INITIALIZED | \
+        PSA_CRYPTO_SUBSYSTEM_TRANSACTION_INITIALIZED)
+
+typedef struct {
+    uint8_t initialized;
+    uint8_t rng_state;
+    mbedtls_psa_random_context_t rng;
+} psa_global_data_t;
+
+static psa_global_data_t global_data;
+
+static uint8_t psa_get_initialized(void)
+{
+    uint8_t initialized;
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_lock(&mbedtls_threading_psa_rngdata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+    initialized = global_data.rng_state == RNG_SEEDED;
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_unlock(&mbedtls_threading_psa_rngdata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_lock(&mbedtls_threading_psa_globaldata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+    initialized =
+        (initialized && (global_data.initialized == PSA_CRYPTO_SUBSYSTEM_ALL_INITIALISED));
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_unlock(&mbedtls_threading_psa_globaldata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+    return initialized;
+}
+
+static uint8_t psa_get_drivers_initialized(void)
+{
+    uint8_t initialized;
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_lock(&mbedtls_threading_psa_globaldata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+    initialized = (global_data.initialized & PSA_CRYPTO_SUBSYSTEM_DRIVER_WRAPPERS_INITIALIZED) != 0;
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_unlock(&mbedtls_threading_psa_globaldata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+    return initialized;
+}
+
+#define GUARD_MODULE_INITIALIZED        \
+    if (psa_get_initialized() == 0)     \
+    return PSA_ERROR_BAD_STATE;
+
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+
+/* Declare a local copy of an input buffer and a variable that will be used
+ * to store a pointer to the start of the buffer.
+ *
+ * Note: This macro must be called before any operations which may jump to
+ * the exit label, so that the local input copy object is safe to be freed.
+ *
+ * Assumptions:
+ * - input is the name of a pointer to the buffer to be copied
+ * - The name LOCAL_INPUT_COPY_OF_input is unused in the current scope
+ * - input_copy_name is a name that is unused in the current scope
+ */
+#define LOCAL_INPUT_DECLARE(input, input_copy_name) \
+    psa_crypto_local_input_t LOCAL_INPUT_COPY_OF_##input = PSA_CRYPTO_LOCAL_INPUT_INIT; \
+    const uint8_t *input_copy_name = NULL;
+
+/* Allocate a copy of the buffer input and set the pointer input_copy to
+ * point to the start of the copy.
+ *
+ * Assumptions:
+ * - psa_status_t status exists
+ * - An exit label is declared
+ * - input is the name of a pointer to the buffer to be copied
+ * - LOCAL_INPUT_DECLARE(input, input_copy) has previously been called
+ */
+#define LOCAL_INPUT_ALLOC(input, length, input_copy) \
+    status = psa_crypto_local_input_alloc(input, length, \
+                                          &LOCAL_INPUT_COPY_OF_##input); \
+    if (status != PSA_SUCCESS) { \
+        goto exit; \
+    } \
+    input_copy = LOCAL_INPUT_COPY_OF_##input.buffer;
+
+/* Free the local input copy allocated previously by LOCAL_INPUT_ALLOC()
+ *
+ * Assumptions:
+ * - input_copy is the name of the input copy pointer set by LOCAL_INPUT_ALLOC()
+ * - input is the name of the original buffer that was copied
+ */
+#define LOCAL_INPUT_FREE(input, input_copy) \
+    input_copy = NULL; \
+    psa_crypto_local_input_free(&LOCAL_INPUT_COPY_OF_##input);
+
+/* Declare a local copy of an output buffer and a variable that will be used
+ * to store a pointer to the start of the buffer.
+ *
+ * Note: This macro must be called before any operations which may jump to
+ * the exit label, so that the local output copy object is safe to be freed.
+ *
+ * Assumptions:
+ * - output is the name of a pointer to the buffer to be copied
+ * - The name LOCAL_OUTPUT_COPY_OF_output is unused in the current scope
+ * - output_copy_name is a name that is unused in the current scope
+ */
+#define LOCAL_OUTPUT_DECLARE(output, output_copy_name) \
+    psa_crypto_local_output_t LOCAL_OUTPUT_COPY_OF_##output = PSA_CRYPTO_LOCAL_OUTPUT_INIT; \
+    uint8_t *output_copy_name = NULL;
+
+/* Allocate a copy of the buffer output and set the pointer output_copy to
+ * point to the start of the copy.
+ *
+ * Assumptions:
+ * - psa_status_t status exists
+ * - An exit label is declared
+ * - output is the name of a pointer to the buffer to be copied
+ * - LOCAL_OUTPUT_DECLARE(output, output_copy) has previously been called
+ */
+#define LOCAL_OUTPUT_ALLOC(output, length, output_copy) \
+    status = psa_crypto_local_output_alloc(output, length, \
+                                           &LOCAL_OUTPUT_COPY_OF_##output); \
+    if (status != PSA_SUCCESS) { \
+        goto exit; \
+    } \
+    output_copy = LOCAL_OUTPUT_COPY_OF_##output.buffer;
+
+/* Free the local output copy allocated previously by LOCAL_OUTPUT_ALLOC()
+ * after first copying back its contents to the original buffer.
+ *
+ * Assumptions:
+ * - psa_status_t status exists
+ * - output_copy is the name of the output copy pointer set by LOCAL_OUTPUT_ALLOC()
+ * - output is the name of the original buffer that was copied
+ */
+#define LOCAL_OUTPUT_FREE(output, output_copy) \
+    output_copy = NULL; \
+    do { \
+        psa_status_t local_output_status; \
+        local_output_status = psa_crypto_local_output_free(&LOCAL_OUTPUT_COPY_OF_##output); \
+        if (local_output_status != PSA_SUCCESS) { \
+            /* Since this error case is an internal error, it's more serious than \
+             * any existing error code and so it's fine to overwrite the existing \
+             * status. */ \
+            status = local_output_status; \
+        } \
+    } while (0)
+#else /* !MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS */
+#define LOCAL_INPUT_DECLARE(input, input_copy_name) \
+    const uint8_t *input_copy_name = NULL;
+#define LOCAL_INPUT_ALLOC(input, length, input_copy) \
+    input_copy = input;
+#define LOCAL_INPUT_FREE(input, input_copy) \
+    input_copy = NULL;
+#define LOCAL_OUTPUT_DECLARE(output, output_copy_name) \
+    uint8_t *output_copy_name = NULL;
+#define LOCAL_OUTPUT_ALLOC(output, length, output_copy) \
+    output_copy = output;
+#define LOCAL_OUTPUT_FREE(output, output_copy) \
+    output_copy = NULL;
+#endif /* !MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS */
+
+
+int psa_can_do_hash(psa_algorithm_t hash_alg)
+{
+    (void) hash_alg;
+    return psa_get_drivers_initialized();
+}
+
+int psa_can_do_cipher(psa_key_type_t key_type, psa_algorithm_t cipher_alg)
+{
+    (void) key_type;
+    (void) cipher_alg;
+    return psa_get_drivers_initialized();
+}
+
+
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_KEY_PAIR_IMPORT) ||       \
+    defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_PUBLIC_KEY) ||     \
+    defined(PSA_WANT_KEY_TYPE_DH_KEY_PAIR_GENERATE)
+static int psa_is_dh_key_size_valid(size_t bits)
+{
+    switch (bits) {
+#if defined(PSA_WANT_DH_RFC7919_2048)
+        case 2048:
+            return 1;
+#endif /* PSA_WANT_DH_RFC7919_2048 */
+#if defined(PSA_WANT_DH_RFC7919_3072)
+        case 3072:
+            return 1;
+#endif /* PSA_WANT_DH_RFC7919_3072 */
+#if defined(PSA_WANT_DH_RFC7919_4096)
+        case 4096:
+            return 1;
+#endif /* PSA_WANT_DH_RFC7919_4096 */
+#if defined(PSA_WANT_DH_RFC7919_6144)
+        case 6144:
+            return 1;
+#endif /* PSA_WANT_DH_RFC7919_6144 */
+#if defined(PSA_WANT_DH_RFC7919_8192)
+        case 8192:
+            return 1;
+#endif /* PSA_WANT_DH_RFC7919_8192 */
+        default:
+            return 0;
+    }
+}
+#endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_KEY_PAIR_IMPORT ||
+          MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_PUBLIC_KEY ||
+          PSA_WANT_KEY_TYPE_DH_KEY_PAIR_GENERATE */
+
+psa_status_t mbedtls_to_psa_error(int ret)
+{
+    /* Mbed TLS error codes can combine a high-level error code and a
+     * low-level error code. The low-level error usually reflects the
+     * root cause better, so dispatch on that preferably. */
+    int low_level_ret = -(-ret & 0x007f);
+    switch (low_level_ret != 0 ? low_level_ret : ret) {
+        case 0:
+            return PSA_SUCCESS;
+
+#if defined(MBEDTLS_AES_C)
+        case MBEDTLS_ERR_AES_INVALID_KEY_LENGTH:
+        case MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH:
+            return PSA_ERROR_NOT_SUPPORTED;
+        case MBEDTLS_ERR_AES_BAD_INPUT_DATA:
+            return PSA_ERROR_INVALID_ARGUMENT;
+#endif
+
+#if defined(MBEDTLS_ASN1_PARSE_C) || defined(MBEDTLS_ASN1_WRITE_C)
+        case MBEDTLS_ERR_ASN1_OUT_OF_DATA:
+        case MBEDTLS_ERR_ASN1_UNEXPECTED_TAG:
+        case MBEDTLS_ERR_ASN1_INVALID_LENGTH:
+        case MBEDTLS_ERR_ASN1_LENGTH_MISMATCH:
+        case MBEDTLS_ERR_ASN1_INVALID_DATA:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_ASN1_ALLOC_FAILED:
+            return PSA_ERROR_INSUFFICIENT_MEMORY;
+        case MBEDTLS_ERR_ASN1_BUF_TOO_SMALL:
+            return PSA_ERROR_BUFFER_TOO_SMALL;
+#endif
+
+#if defined(MBEDTLS_CAMELLIA_C)
+        case MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA:
+        case MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH:
+            return PSA_ERROR_NOT_SUPPORTED;
+#endif
+
+#if defined(MBEDTLS_CCM_C)
+        case MBEDTLS_ERR_CCM_BAD_INPUT:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_CCM_AUTH_FAILED:
+            return PSA_ERROR_INVALID_SIGNATURE;
+#endif
+
+#if defined(MBEDTLS_CHACHA20_C)
+        case MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA:
+            return PSA_ERROR_INVALID_ARGUMENT;
+#endif
+
+#if defined(MBEDTLS_CHACHAPOLY_C)
+        case MBEDTLS_ERR_CHACHAPOLY_BAD_STATE:
+            return PSA_ERROR_BAD_STATE;
+        case MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED:
+            return PSA_ERROR_INVALID_SIGNATURE;
+#endif
+
+#if defined(MBEDTLS_CIPHER_C)
+        case MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE:
+            return PSA_ERROR_NOT_SUPPORTED;
+        case MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_CIPHER_ALLOC_FAILED:
+            return PSA_ERROR_INSUFFICIENT_MEMORY;
+        case MBEDTLS_ERR_CIPHER_INVALID_PADDING:
+            return PSA_ERROR_INVALID_PADDING;
+        case MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_CIPHER_AUTH_FAILED:
+            return PSA_ERROR_INVALID_SIGNATURE;
+        case MBEDTLS_ERR_CIPHER_INVALID_CONTEXT:
+            return PSA_ERROR_CORRUPTION_DETECTED;
+#endif
+
+#if !(defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) ||      \
+            defined(MBEDTLS_PSA_HMAC_DRBG_MD_TYPE))
+        /* Only check CTR_DRBG error codes if underlying mbedtls_xxx
+         * functions are passed a CTR_DRBG instance. */
+        case MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED:
+            return PSA_ERROR_INSUFFICIENT_ENTROPY;
+        case MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG:
+        case MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG:
+            return PSA_ERROR_NOT_SUPPORTED;
+        case MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR:
+            return PSA_ERROR_INSUFFICIENT_ENTROPY;
+#endif
+
+#if defined(MBEDTLS_DES_C)
+        case MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH:
+            return PSA_ERROR_NOT_SUPPORTED;
+#endif
+
+        case MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED:
+        case MBEDTLS_ERR_ENTROPY_NO_STRONG_SOURCE:
+        case MBEDTLS_ERR_ENTROPY_SOURCE_FAILED:
+            return PSA_ERROR_INSUFFICIENT_ENTROPY;
+
+#if defined(MBEDTLS_GCM_C)
+        case MBEDTLS_ERR_GCM_AUTH_FAILED:
+            return PSA_ERROR_INVALID_SIGNATURE;
+        case MBEDTLS_ERR_GCM_BUFFER_TOO_SMALL:
+            return PSA_ERROR_BUFFER_TOO_SMALL;
+        case MBEDTLS_ERR_GCM_BAD_INPUT:
+            return PSA_ERROR_INVALID_ARGUMENT;
+#endif
+
+#if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) &&        \
+            defined(MBEDTLS_PSA_HMAC_DRBG_MD_TYPE)
+        /* Only check HMAC_DRBG error codes if underlying mbedtls_xxx
+         * functions are passed a HMAC_DRBG instance. */
+        case MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED:
+            return PSA_ERROR_INSUFFICIENT_ENTROPY;
+        case MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG:
+        case MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG:
+            return PSA_ERROR_NOT_SUPPORTED;
+        case MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR:
+            return PSA_ERROR_INSUFFICIENT_ENTROPY;
+#endif
+
+#if defined(MBEDTLS_MD_LIGHT)
+        case MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE:
+            return PSA_ERROR_NOT_SUPPORTED;
+        case MBEDTLS_ERR_MD_BAD_INPUT_DATA:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_MD_ALLOC_FAILED:
+            return PSA_ERROR_INSUFFICIENT_MEMORY;
+#if defined(MBEDTLS_FS_IO)
+        case MBEDTLS_ERR_MD_FILE_IO_ERROR:
+            return PSA_ERROR_STORAGE_FAILURE;
+#endif
+#endif
+
+#if defined(MBEDTLS_BIGNUM_C)
+#if defined(MBEDTLS_FS_IO)
+        case MBEDTLS_ERR_MPI_FILE_IO_ERROR:
+            return PSA_ERROR_STORAGE_FAILURE;
+#endif
+        case MBEDTLS_ERR_MPI_BAD_INPUT_DATA:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_MPI_INVALID_CHARACTER:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL:
+            return PSA_ERROR_BUFFER_TOO_SMALL;
+        case MBEDTLS_ERR_MPI_NEGATIVE_VALUE:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_MPI_DIVISION_BY_ZERO:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_MPI_NOT_ACCEPTABLE:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_MPI_ALLOC_FAILED:
+            return PSA_ERROR_INSUFFICIENT_MEMORY;
+#endif
+
+#if defined(MBEDTLS_PK_C)
+        case MBEDTLS_ERR_PK_ALLOC_FAILED:
+            return PSA_ERROR_INSUFFICIENT_MEMORY;
+        case MBEDTLS_ERR_PK_TYPE_MISMATCH:
+        case MBEDTLS_ERR_PK_BAD_INPUT_DATA:
+            return PSA_ERROR_INVALID_ARGUMENT;
+#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) || defined(MBEDTLS_FS_IO) || \
+            defined(MBEDTLS_PSA_ITS_FILE_C)
+        case MBEDTLS_ERR_PK_FILE_IO_ERROR:
+            return PSA_ERROR_STORAGE_FAILURE;
+#endif
+        case MBEDTLS_ERR_PK_KEY_INVALID_VERSION:
+        case MBEDTLS_ERR_PK_KEY_INVALID_FORMAT:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_PK_UNKNOWN_PK_ALG:
+            return PSA_ERROR_NOT_SUPPORTED;
+        case MBEDTLS_ERR_PK_PASSWORD_REQUIRED:
+        case MBEDTLS_ERR_PK_PASSWORD_MISMATCH:
+            return PSA_ERROR_NOT_PERMITTED;
+        case MBEDTLS_ERR_PK_INVALID_PUBKEY:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_PK_INVALID_ALG:
+        case MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE:
+        case MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE:
+            return PSA_ERROR_NOT_SUPPORTED;
+        case MBEDTLS_ERR_PK_SIG_LEN_MISMATCH:
+            return PSA_ERROR_INVALID_SIGNATURE;
+        case MBEDTLS_ERR_PK_BUFFER_TOO_SMALL:
+            return PSA_ERROR_BUFFER_TOO_SMALL;
+#endif
+
+        case MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED:
+            return PSA_ERROR_HARDWARE_FAILURE;
+        case MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED:
+            return PSA_ERROR_NOT_SUPPORTED;
+
+#if defined(MBEDTLS_RSA_C)
+        case MBEDTLS_ERR_RSA_BAD_INPUT_DATA:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_RSA_INVALID_PADDING:
+            return PSA_ERROR_INVALID_PADDING;
+        case MBEDTLS_ERR_RSA_KEY_GEN_FAILED:
+            return PSA_ERROR_HARDWARE_FAILURE;
+        case MBEDTLS_ERR_RSA_KEY_CHECK_FAILED:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_RSA_PUBLIC_FAILED:
+        case MBEDTLS_ERR_RSA_PRIVATE_FAILED:
+            return PSA_ERROR_CORRUPTION_DETECTED;
+        case MBEDTLS_ERR_RSA_VERIFY_FAILED:
+            return PSA_ERROR_INVALID_SIGNATURE;
+        case MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE:
+            return PSA_ERROR_BUFFER_TOO_SMALL;
+        case MBEDTLS_ERR_RSA_RNG_FAILED:
+            return PSA_ERROR_INSUFFICIENT_ENTROPY;
+#endif
+
+#if defined(MBEDTLS_ECP_LIGHT)
+        case MBEDTLS_ERR_ECP_BAD_INPUT_DATA:
+        case MBEDTLS_ERR_ECP_INVALID_KEY:
+            return PSA_ERROR_INVALID_ARGUMENT;
+        case MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL:
+            return PSA_ERROR_BUFFER_TOO_SMALL;
+        case MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE:
+            return PSA_ERROR_NOT_SUPPORTED;
+        case MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH:
+        case MBEDTLS_ERR_ECP_VERIFY_FAILED:
+            return PSA_ERROR_INVALID_SIGNATURE;
+        case MBEDTLS_ERR_ECP_ALLOC_FAILED:
+            return PSA_ERROR_INSUFFICIENT_MEMORY;
+        case MBEDTLS_ERR_ECP_RANDOM_FAILED:
+            return PSA_ERROR_INSUFFICIENT_ENTROPY;
+
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+        case MBEDTLS_ERR_ECP_IN_PROGRESS:
+            return PSA_OPERATION_INCOMPLETE;
+#endif
+#endif
+
+        case MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED:
+            return PSA_ERROR_CORRUPTION_DETECTED;
+
+        default:
+            return PSA_ERROR_GENERIC_ERROR;
+    }
+}
+
+/**
+ * \brief                       For output buffers which contain "tags"
+ *                              (outputs that may be checked for validity like
+ *                              hashes, MACs and signatures), fill the unused
+ *                              part of the output buffer (the whole buffer on
+ *                              error, the trailing part on success) with
+ *                              something that isn't a valid tag (barring an
+ *                              attack on the tag and deliberately-crafted
+ *                              input), in case the caller doesn't check the
+ *                              return status properly.
+ *
+ * \param output_buffer         Pointer to buffer to wipe. May not be NULL
+ *                              unless \p output_buffer_size is zero.
+ * \param status                Status of function called to generate
+ *                              output_buffer originally
+ * \param output_buffer_size    Size of output buffer. If zero, \p output_buffer
+ *                              could be NULL.
+ * \param output_buffer_length  Length of data written to output_buffer, must be
+ *                              less than \p output_buffer_size
+ */
+static void psa_wipe_tag_output_buffer(uint8_t *output_buffer, psa_status_t status,
+                                       size_t output_buffer_size, size_t output_buffer_length)
+{
+    size_t offset = 0;
+
+    if (output_buffer_size == 0) {
+        /* If output_buffer_size is 0 then we have nothing to do. We must not
+           call memset because output_buffer may be NULL in this case */
+        return;
+    }
+
+    if (status == PSA_SUCCESS) {
+        offset = output_buffer_length;
+    }
+
+    memset(output_buffer + offset, '!', output_buffer_size - offset);
+}
+
+
+psa_status_t psa_validate_unstructured_key_bit_size(psa_key_type_t type,
+                                                    size_t bits)
+{
+    /* Check that the bit size is acceptable for the key type */
+    switch (type) {
+        case PSA_KEY_TYPE_RAW_DATA:
+        case PSA_KEY_TYPE_HMAC:
+        case PSA_KEY_TYPE_DERIVE:
+        case PSA_KEY_TYPE_PASSWORD:
+        case PSA_KEY_TYPE_PASSWORD_HASH:
+            break;
+#if defined(PSA_WANT_KEY_TYPE_AES)
+        case PSA_KEY_TYPE_AES:
+            if (bits != 128 && bits != 192 && bits != 256) {
+                return PSA_ERROR_INVALID_ARGUMENT;
+            }
+            break;
+#endif
+#if defined(PSA_WANT_KEY_TYPE_ARIA)
+        case PSA_KEY_TYPE_ARIA:
+            if (bits != 128 && bits != 192 && bits != 256) {
+                return PSA_ERROR_INVALID_ARGUMENT;
+            }
+            break;
+#endif
+#if defined(PSA_WANT_KEY_TYPE_CAMELLIA)
+        case PSA_KEY_TYPE_CAMELLIA:
+            if (bits != 128 && bits != 192 && bits != 256) {
+                return PSA_ERROR_INVALID_ARGUMENT;
+            }
+            break;
+#endif
+#if defined(PSA_WANT_KEY_TYPE_DES)
+        case PSA_KEY_TYPE_DES:
+            if (bits != 64 && bits != 128 && bits != 192) {
+                return PSA_ERROR_INVALID_ARGUMENT;
+            }
+            break;
+#endif
+#if defined(PSA_WANT_KEY_TYPE_CHACHA20)
+        case PSA_KEY_TYPE_CHACHA20:
+            if (bits != 256) {
+                return PSA_ERROR_INVALID_ARGUMENT;
+            }
+            break;
+#endif
+        default:
+            return PSA_ERROR_NOT_SUPPORTED;
+    }
+    if (bits % 8 != 0) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    return PSA_SUCCESS;
+}
+
+/** Check whether a given key type is valid for use with a given MAC algorithm
+ *
+ * Upon successful return of this function, the behavior of #PSA_MAC_LENGTH
+ * when called with the validated \p algorithm and \p key_type is well-defined.
+ *
+ * \param[in] algorithm     The specific MAC algorithm (can be wildcard).
+ * \param[in] key_type      The key type of the key to be used with the
+ *                          \p algorithm.
+ *
+ * \retval #PSA_SUCCESS
+ *         The \p key_type is valid for use with the \p algorithm
+ * \retval #PSA_ERROR_INVALID_ARGUMENT
+ *         The \p key_type is not valid for use with the \p algorithm
+ */
+MBEDTLS_STATIC_TESTABLE psa_status_t psa_mac_key_can_do(
+    psa_algorithm_t algorithm,
+    psa_key_type_t key_type)
+{
+    if (PSA_ALG_IS_HMAC(algorithm)) {
+        if (key_type == PSA_KEY_TYPE_HMAC) {
+            return PSA_SUCCESS;
+        }
+    }
+
+    if (PSA_ALG_IS_BLOCK_CIPHER_MAC(algorithm)) {
+        /* Check that we're calling PSA_BLOCK_CIPHER_BLOCK_LENGTH with a cipher
+         * key. */
+        if ((key_type & PSA_KEY_TYPE_CATEGORY_MASK) ==
+            PSA_KEY_TYPE_CATEGORY_SYMMETRIC) {
+            /* PSA_BLOCK_CIPHER_BLOCK_LENGTH returns 1 for stream ciphers and
+             * the block length (larger than 1) for block ciphers. */
+            if (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) > 1) {
+                return PSA_SUCCESS;
+            }
+        }
+    }
+
+    return PSA_ERROR_INVALID_ARGUMENT;
+}
+
+psa_status_t psa_allocate_buffer_to_slot(psa_key_slot_t *slot,
+                                         size_t buffer_length)
+{
+    if (slot->key.data != NULL) {
+        return PSA_ERROR_ALREADY_EXISTS;
+    }
+
+    slot->key.data = mbedtls_calloc(1, buffer_length);
+    if (slot->key.data == NULL) {
+        return PSA_ERROR_INSUFFICIENT_MEMORY;
+    }
+
+    slot->key.bytes = buffer_length;
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_copy_key_material_into_slot(psa_key_slot_t *slot,
+                                             const uint8_t *data,
+                                             size_t data_length)
+{
+    psa_status_t status = psa_allocate_buffer_to_slot(slot,
+                                                      data_length);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    memcpy(slot->key.data, data, data_length);
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_import_key_into_slot(
+    const psa_key_attributes_t *attributes,
+    const uint8_t *data, size_t data_length,
+    uint8_t *key_buffer, size_t key_buffer_size,
+    size_t *key_buffer_length, size_t *bits)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_type_t type = attributes->type;
+
+    /* zero-length keys are never supported. */
+    if (data_length == 0) {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    if (key_type_is_raw_bytes(type)) {
+        *bits = PSA_BYTES_TO_BITS(data_length);
+
+        status = psa_validate_unstructured_key_bit_size(attributes->type,
+                                                        *bits);
+        if (status != PSA_SUCCESS) {
+            return status;
+        }
+
+        /* Copy the key material. */
+        memcpy(key_buffer, data, data_length);
+        *key_buffer_length = data_length;
+        (void) key_buffer_size;
+
+        return PSA_SUCCESS;
+    } else if (PSA_KEY_TYPE_IS_ASYMMETRIC(type)) {
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_KEY_PAIR_IMPORT) || \
+        defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_PUBLIC_KEY)
+        if (PSA_KEY_TYPE_IS_DH(type)) {
+            if (psa_is_dh_key_size_valid(PSA_BYTES_TO_BITS(data_length)) == 0) {
+                return PSA_ERROR_NOT_SUPPORTED;
+            }
+            return mbedtls_psa_ffdh_import_key(attributes,
+                                               data, data_length,
+                                               key_buffer, key_buffer_size,
+                                               key_buffer_length,
+                                               bits);
+        }
+#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_KEY_PAIR_IMPORT) ||
+        * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_PUBLIC_KEY) */
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_IMPORT) || \
+        defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY)
+        if (PSA_KEY_TYPE_IS_ECC(type)) {
+            return mbedtls_psa_ecp_import_key(attributes,
+                                              data, data_length,
+                                              key_buffer, key_buffer_size,
+                                              key_buffer_length,
+                                              bits);
+        }
+#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_IMPORT) ||
+        * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) */
+#if (defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR_IMPORT) && \
+        defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR_EXPORT)) || \
+        defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY)
+        if (PSA_KEY_TYPE_IS_RSA(type)) {
+            return mbedtls_psa_rsa_import_key(attributes,
+                                              data, data_length,
+                                              key_buffer, key_buffer_size,
+                                              key_buffer_length,
+                                              bits);
+        }
+#endif /* (defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR_IMPORT) &&
+           defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR_EXPORT)) ||
+        * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */
+    }
+
+    return PSA_ERROR_NOT_SUPPORTED;
+}
+
+/** Calculate the intersection of two algorithm usage policies.
+ *
+ * Return 0 (which allows no operation) on incompatibility.
+ */
+static psa_algorithm_t psa_key_policy_algorithm_intersection(
+    psa_key_type_t key_type,
+    psa_algorithm_t alg1,
+    psa_algorithm_t alg2)
+{
+    /* Common case: both sides actually specify the same policy. */
+    if (alg1 == alg2) {
+        return alg1;
+    }
+    /* If the policies are from the same hash-and-sign family, check
+     * if one is a wildcard. If so the other has the specific algorithm. */
+    if (PSA_ALG_IS_SIGN_HASH(alg1) &&
+        PSA_ALG_IS_SIGN_HASH(alg2) &&
+        (alg1 & ~PSA_ALG_HASH_MASK) == (alg2 & ~PSA_ALG_HASH_MASK)) {
+        if (PSA_ALG_SIGN_GET_HASH(alg1) == PSA_ALG_ANY_HASH) {
+            return alg2;
+        }
+        if (PSA_ALG_SIGN_GET_HASH(alg2) == PSA_ALG_ANY_HASH) {
+            return alg1;
+        }
+    }
+    /* If the policies are from the same AEAD family, check whether
+     * one of them is a minimum-tag-length wildcard. Calculate the most
+     * restrictive tag length. */
+    if (PSA_ALG_IS_AEAD(alg1) && PSA_ALG_IS_AEAD(alg2) &&
+        (PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg1, 0) ==
+         PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg2, 0))) {
+        size_t alg1_len = PSA_ALG_AEAD_GET_TAG_LENGTH(alg1);
+        size_t alg2_len = PSA_ALG_AEAD_GET_TAG_LENGTH(alg2);
+        size_t restricted_len = alg1_len > alg2_len ? alg1_len : alg2_len;
+
+        /* If both are wildcards, return most restrictive wildcard */
+        if (((alg1 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0) &&
+            ((alg2 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0)) {
+            return PSA_ALG_AEAD_WITH_AT_LEAST_THIS_LENGTH_TAG(
+                alg1, restricted_len);
+        }
+        /* If only one is a wildcard, return specific algorithm if compatible. */
+        if (((alg1 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0) &&
+            (alg1_len <= alg2_len)) {
+            return alg2;
+        }
+        if (((alg2 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0) &&
+            (alg2_len <= alg1_len)) {
+            return alg1;
+        }
+    }
+    /* If the policies are from the same MAC family, check whether one
+     * of them is a minimum-MAC-length policy. Calculate the most
+     * restrictive tag length. */
+    if (PSA_ALG_IS_MAC(alg1) && PSA_ALG_IS_MAC(alg2) &&
+        (PSA_ALG_FULL_LENGTH_MAC(alg1) ==
+         PSA_ALG_FULL_LENGTH_MAC(alg2))) {
+        /* Validate the combination of key type and algorithm. Since the base
+         * algorithm of alg1 and alg2 are the same, we only need this once. */
+        if (PSA_SUCCESS != psa_mac_key_can_do(alg1, key_type)) {
+            return 0;
+        }
+
+        /* Get the (exact or at-least) output lengths for both sides of the
+         * requested intersection. None of the currently supported algorithms
+         * have an output length dependent on the actual key size, so setting it
+         * to a bogus value of 0 is currently OK.
+         *
+         * Note that for at-least-this-length wildcard algorithms, the output
+         * length is set to the shortest allowed length, which allows us to
+         * calculate the most restrictive tag length for the intersection. */
+        size_t alg1_len = PSA_MAC_LENGTH(key_type, 0, alg1);
+        size_t alg2_len = PSA_MAC_LENGTH(key_type, 0, alg2);
+        size_t restricted_len = alg1_len > alg2_len ? alg1_len : alg2_len;
+
+        /* If both are wildcards, return most restrictive wildcard */
+        if (((alg1 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0) &&
+            ((alg2 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0)) {
+            return PSA_ALG_AT_LEAST_THIS_LENGTH_MAC(alg1, restricted_len);
+        }
+
+        /* If only one is an at-least-this-length policy, the intersection would
+         * be the other (fixed-length) policy as long as said fixed length is
+         * equal to or larger than the shortest allowed length. */
+        if ((alg1 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0) {
+            return (alg1_len <= alg2_len) ? alg2 : 0;
+        }
+        if ((alg2 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0) {
+            return (alg2_len <= alg1_len) ? alg1 : 0;
+        }
+
+        /* If none of them are wildcards, check whether they define the same tag
+         * length. This is still possible here when one is default-length and
+         * the other specific-length. Ensure to always return the
+         * specific-length version for the intersection. */
+        if (alg1_len == alg2_len) {
+            return PSA_ALG_TRUNCATED_MAC(alg1, alg1_len);
+        }
+    }
+    /* If the policies are incompatible, allow nothing. */
+    return 0;
+}
+
+static int psa_key_algorithm_permits(psa_key_type_t key_type,
+                                     psa_algorithm_t policy_alg,
+                                     psa_algorithm_t requested_alg)
+{
+    /* Common case: the policy only allows requested_alg. */
+    if (requested_alg == policy_alg) {
+        return 1;
+    }
+    /* If policy_alg is a hash-and-sign with a wildcard for the hash,
+     * and requested_alg is the same hash-and-sign family with any hash,
+     * then requested_alg is compliant with policy_alg. */
+    if (PSA_ALG_IS_SIGN_HASH(requested_alg) &&
+        PSA_ALG_SIGN_GET_HASH(policy_alg) == PSA_ALG_ANY_HASH) {
+        return (policy_alg & ~PSA_ALG_HASH_MASK) ==
+               (requested_alg & ~PSA_ALG_HASH_MASK);
+    }
+    /* If policy_alg is a wildcard AEAD algorithm of the same base as
+     * the requested algorithm, check the requested tag length to be
+     * equal-length or longer than the wildcard-specified length. */
+    if (PSA_ALG_IS_AEAD(policy_alg) &&
+        PSA_ALG_IS_AEAD(requested_alg) &&
+        (PSA_ALG_AEAD_WITH_SHORTENED_TAG(policy_alg, 0) ==
+         PSA_ALG_AEAD_WITH_SHORTENED_TAG(requested_alg, 0)) &&
+        ((policy_alg & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) != 0)) {
+        return PSA_ALG_AEAD_GET_TAG_LENGTH(policy_alg) <=
+               PSA_ALG_AEAD_GET_TAG_LENGTH(requested_alg);
+    }
+    /* If policy_alg is a MAC algorithm of the same base as the requested
+     * algorithm, check whether their MAC lengths are compatible. */
+    if (PSA_ALG_IS_MAC(policy_alg) &&
+        PSA_ALG_IS_MAC(requested_alg) &&
+        (PSA_ALG_FULL_LENGTH_MAC(policy_alg) ==
+         PSA_ALG_FULL_LENGTH_MAC(requested_alg))) {
+        /* Validate the combination of key type and algorithm. Since the policy
+         * and requested algorithms are the same, we only need this once. */
+        if (PSA_SUCCESS != psa_mac_key_can_do(policy_alg, key_type)) {
+            return 0;
+        }
+
+        /* Get both the requested output length for the algorithm which is to be
+         * verified, and the default output length for the base algorithm.
+         * Note that none of the currently supported algorithms have an output
+         * length dependent on actual key size, so setting it to a bogus value
+         * of 0 is currently OK. */
+        size_t requested_output_length = PSA_MAC_LENGTH(
+            key_type, 0, requested_alg);
+        size_t default_output_length = PSA_MAC_LENGTH(
+            key_type, 0,
+            PSA_ALG_FULL_LENGTH_MAC(requested_alg));
+
+        /* If the policy is default-length, only allow an algorithm with
+         * a declared exact-length matching the default. */
+        if (PSA_MAC_TRUNCATED_LENGTH(policy_alg) == 0) {
+            return requested_output_length == default_output_length;
+        }
+
+        /* If the requested algorithm is default-length, allow it if the policy
+         * length exactly matches the default length. */
+        if (PSA_MAC_TRUNCATED_LENGTH(requested_alg) == 0 &&
+            PSA_MAC_TRUNCATED_LENGTH(policy_alg) == default_output_length) {
+            return 1;
+        }
+
+        /* If policy_alg is an at-least-this-length wildcard MAC algorithm,
+         * check for the requested MAC length to be equal to or longer than the
+         * minimum allowed length. */
+        if ((policy_alg & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) != 0) {
+            return PSA_MAC_TRUNCATED_LENGTH(policy_alg) <=
+                   requested_output_length;
+        }
+    }
+    /* If policy_alg is a generic key agreement operation, then using it for
+     * a key derivation with that key agreement should also be allowed. This
+     * behaviour is expected to be defined in a future specification version. */
+    if (PSA_ALG_IS_RAW_KEY_AGREEMENT(policy_alg) &&
+        PSA_ALG_IS_KEY_AGREEMENT(requested_alg)) {
+        return PSA_ALG_KEY_AGREEMENT_GET_BASE(requested_alg) ==
+               policy_alg;
+    }
+    /* If it isn't explicitly permitted, it's forbidden. */
+    return 0;
+}
+
+/** Test whether a policy permits an algorithm.
+ *
+ * The caller must test usage flags separately.
+ *
+ * \note This function requires providing the key type for which the policy is
+ *       being validated, since some algorithm policy definitions (e.g. MAC)
+ *       have different properties depending on what kind of cipher it is
+ *       combined with.
+ *
+ * \retval PSA_SUCCESS                  When \p alg is a specific algorithm
+ *                                      allowed by the \p policy.
+ * \retval PSA_ERROR_INVALID_ARGUMENT   When \p alg is not a specific algorithm
+ * \retval PSA_ERROR_NOT_PERMITTED      When \p alg is a specific algorithm, but
+ *                                      the \p policy does not allow it.
+ */
+static psa_status_t psa_key_policy_permits(const psa_key_policy_t *policy,
+                                           psa_key_type_t key_type,
+                                           psa_algorithm_t alg)
+{
+    /* '0' is not a valid algorithm */
+    if (alg == 0) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    /* A requested algorithm cannot be a wildcard. */
+    if (PSA_ALG_IS_WILDCARD(alg)) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    if (psa_key_algorithm_permits(key_type, policy->alg, alg) ||
+        psa_key_algorithm_permits(key_type, policy->alg2, alg)) {
+        return PSA_SUCCESS;
+    } else {
+        return PSA_ERROR_NOT_PERMITTED;
+    }
+}
+
+/** Restrict a key policy based on a constraint.
+ *
+ * \note This function requires providing the key type for which the policy is
+ *       being restricted, since some algorithm policy definitions (e.g. MAC)
+ *       have different properties depending on what kind of cipher it is
+ *       combined with.
+ *
+ * \param[in] key_type      The key type for which to restrict the policy
+ * \param[in,out] policy    The policy to restrict.
+ * \param[in] constraint    The policy constraint to apply.
+ *
+ * \retval #PSA_SUCCESS
+ *         \c *policy contains the intersection of the original value of
+ *         \c *policy and \c *constraint.
+ * \retval #PSA_ERROR_INVALID_ARGUMENT
+ *         \c key_type, \c *policy and \c *constraint are incompatible.
+ *         \c *policy is unchanged.
+ */
+static psa_status_t psa_restrict_key_policy(
+    psa_key_type_t key_type,
+    psa_key_policy_t *policy,
+    const psa_key_policy_t *constraint)
+{
+    psa_algorithm_t intersection_alg =
+        psa_key_policy_algorithm_intersection(key_type, policy->alg,
+                                              constraint->alg);
+    psa_algorithm_t intersection_alg2 =
+        psa_key_policy_algorithm_intersection(key_type, policy->alg2,
+                                              constraint->alg2);
+    if (intersection_alg == 0 && policy->alg != 0 && constraint->alg != 0) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+    if (intersection_alg2 == 0 && policy->alg2 != 0 && constraint->alg2 != 0) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+    policy->usage &= constraint->usage;
+    policy->alg = intersection_alg;
+    policy->alg2 = intersection_alg2;
+    return PSA_SUCCESS;
+}
+
+/** Get the description of a key given its identifier and policy constraints
+ *  and lock it.
+ *
+ * The key must have allow all the usage flags set in \p usage. If \p alg is
+ * nonzero, the key must allow operations with this algorithm. If \p alg is
+ * zero, the algorithm is not checked.
+ *
+ * In case of a persistent key, the function loads the description of the key
+ * into a key slot if not already done.
+ *
+ * On success, the returned key slot has been registered for reading.
+ * It is the responsibility of the caller to then unregister
+ * once they have finished reading the contents of the slot.
+ * The caller unregisters by calling psa_unregister_read() or
+ * psa_unregister_read_under_mutex(). psa_unregister_read() must be called
+ * if and only if the caller already holds the global key slot mutex
+ * (when mutexes are enabled). psa_unregister_read_under_mutex() encapsulates
+ * the unregister with mutex lock and unlock operations.
+ */
+static psa_status_t psa_get_and_lock_key_slot_with_policy(
+    mbedtls_svc_key_id_t key,
+    psa_key_slot_t **p_slot,
+    psa_key_usage_t usage,
+    psa_algorithm_t alg)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot = NULL;
+
+    status = psa_get_and_lock_key_slot(key, p_slot);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+    slot = *p_slot;
+
+    /* Enforce that usage policy for the key slot contains all the flags
+     * required by the usage parameter. There is one exception: public
+     * keys can always be exported, so we treat public key objects as
+     * if they had the export flag. */
+    if (PSA_KEY_TYPE_IS_PUBLIC_KEY(slot->attr.type)) {
+        usage &= ~PSA_KEY_USAGE_EXPORT;
+    }
+
+    if ((slot->attr.policy.usage & usage) != usage) {
+        status = PSA_ERROR_NOT_PERMITTED;
+        goto error;
+    }
+
+    /* Enforce that the usage policy permits the requested algorithm. */
+    if (alg != 0) {
+        status = psa_key_policy_permits(&slot->attr.policy,
+                                        slot->attr.type,
+                                        alg);
+        if (status != PSA_SUCCESS) {
+            goto error;
+        }
+    }
+
+    return PSA_SUCCESS;
+
+error:
+    *p_slot = NULL;
+    psa_unregister_read_under_mutex(slot);
+
+    return status;
+}
+
+/** Get a key slot containing a transparent key and lock it.
+ *
+ * A transparent key is a key for which the key material is directly
+ * available, as opposed to a key in a secure element and/or to be used
+ * by a secure element.
+ *
+ * This is a temporary function that may be used instead of
+ * psa_get_and_lock_key_slot_with_policy() when there is no opaque key support
+ * for a cryptographic operation.
+ *
+ * On success, the returned key slot has been registered for reading.
+ * It is the responsibility of the caller to then unregister
+ * once they have finished reading the contents of the slot.
+ * The caller unregisters by calling psa_unregister_read() or
+ * psa_unregister_read_under_mutex(). psa_unregister_read() must be called
+ * if and only if the caller already holds the global key slot mutex
+ * (when mutexes are enabled). psa_unregister_read_under_mutex() encapsulates
+ * psa_unregister_read() with mutex lock and unlock operations.
+ */
+static psa_status_t psa_get_and_lock_transparent_key_slot_with_policy(
+    mbedtls_svc_key_id_t key,
+    psa_key_slot_t **p_slot,
+    psa_key_usage_t usage,
+    psa_algorithm_t alg)
+{
+    psa_status_t status = psa_get_and_lock_key_slot_with_policy(key, p_slot,
+                                                                usage, alg);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    if (psa_key_lifetime_is_external((*p_slot)->attr.lifetime)) {
+        psa_unregister_read_under_mutex(*p_slot);
+        *p_slot = NULL;
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_remove_key_data_from_memory(psa_key_slot_t *slot)
+{
+    if (slot->key.data != NULL) {
+        mbedtls_zeroize_and_free(slot->key.data, slot->key.bytes);
+    }
+
+    slot->key.data = NULL;
+    slot->key.bytes = 0;
+
+    return PSA_SUCCESS;
+}
+
+/** Completely wipe a slot in memory, including its policy.
+ * Persistent storage is not affected. */
+psa_status_t psa_wipe_key_slot(psa_key_slot_t *slot)
+{
+    psa_status_t status = psa_remove_key_data_from_memory(slot);
+
+    /*
+     * As the return error code may not be handled in case of multiple errors,
+     * do our best to report an unexpected amount of registered readers or
+     * an unexpected state.
+     * Assert with MBEDTLS_TEST_HOOK_TEST_ASSERT that the slot is valid for
+     * wiping.
+     * if the MBEDTLS_TEST_HOOKS configuration option is enabled and the
+     * function is called as part of the execution of a test suite, the
+     * execution of the test suite is stopped in error if the assertion fails.
+     */
+    switch (slot->state) {
+        case PSA_SLOT_FULL:
+        /* In this state psa_wipe_key_slot() must only be called if the
+         * caller is the last reader. */
+        case PSA_SLOT_PENDING_DELETION:
+            /* In this state psa_wipe_key_slot() must only be called if the
+             * caller is the last reader. */
+            if (slot->var.occupied.registered_readers != 1) {
+                MBEDTLS_TEST_HOOK_TEST_ASSERT(slot->var.occupied.registered_readers == 1);
+                status = PSA_ERROR_CORRUPTION_DETECTED;
+            }
+            break;
+        case PSA_SLOT_FILLING:
+            /* In this state registered_readers must be 0. */
+            if (slot->var.occupied.registered_readers != 0) {
+                MBEDTLS_TEST_HOOK_TEST_ASSERT(slot->var.occupied.registered_readers == 0);
+                status = PSA_ERROR_CORRUPTION_DETECTED;
+            }
+            break;
+        case PSA_SLOT_EMPTY:
+            /* The slot is already empty, it cannot be wiped. */
+            MBEDTLS_TEST_HOOK_TEST_ASSERT(slot->state != PSA_SLOT_EMPTY);
+            status = PSA_ERROR_CORRUPTION_DETECTED;
+            break;
+        default:
+            /* The slot's state is invalid. */
+            status = PSA_ERROR_CORRUPTION_DETECTED;
+    }
+
+#if defined(MBEDTLS_PSA_KEY_STORE_DYNAMIC)
+    size_t slice_index = slot->slice_index;
+#endif /* MBEDTLS_PSA_KEY_STORE_DYNAMIC */
+
+
+    /* Multipart operations may still be using the key. This is safe
+     * because all multipart operation objects are independent from
+     * the key slot: if they need to access the key after the setup
+     * phase, they have a copy of the key. Note that this means that
+     * key material can linger until all operations are completed. */
+    /* At this point, key material and other type-specific content has
+     * been wiped. Clear remaining metadata. We can call memset and not
+     * zeroize because the metadata is not particularly sensitive.
+     * This memset also sets the slot's state to PSA_SLOT_EMPTY. */
+    memset(slot, 0, sizeof(*slot));
+
+#if defined(MBEDTLS_PSA_KEY_STORE_DYNAMIC)
+    /* If the slot is already corrupted, something went deeply wrong,
+     * like a thread still using the slot or a stray pointer leading
+     * to the slot's memory being used for another object. Let the slot
+     * leak rather than make the corruption worse. */
+    if (status == PSA_SUCCESS) {
+        status = psa_free_key_slot(slice_index, slot);
+    }
+#endif /* MBEDTLS_PSA_KEY_STORE_DYNAMIC */
+
+    return status;
+}
+
+psa_status_t psa_destroy_key(mbedtls_svc_key_id_t key)
+{
+    psa_key_slot_t *slot;
+    psa_status_t status; /* status of the last operation */
+    psa_status_t overall_status = PSA_SUCCESS;
+#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
+    psa_se_drv_table_entry_t *driver;
+#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
+
+    if (mbedtls_svc_key_id_is_null(key)) {
+        return PSA_SUCCESS;
+    }
+
+    /*
+     * Get the description of the key in a key slot, and register to read it.
+     * In the case of a persistent key, this will load the key description
+     * from persistent memory if not done yet.
+     * We cannot avoid this loading as without it we don't know if
+     * the key is operated by an SE or not and this information is needed by
+     * the current implementation. */
+    status = psa_get_and_lock_key_slot(key, &slot);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+#if defined(MBEDTLS_THREADING_C)
+    /* We cannot unlock between setting the state to PENDING_DELETION
+     * and destroying the key in storage, as otherwise another thread
+     * could load the key into a new slot and the key will not be
+     * fully destroyed. */
+    PSA_THREADING_CHK_GOTO_EXIT(mbedtls_mutex_lock(
+                                    &mbedtls_threading_key_slot_mutex));
+
+    if (slot->state == PSA_SLOT_PENDING_DELETION) {
+        /* Another thread has destroyed the key between us locking the slot
+         * and us gaining the mutex. Unregister from the slot,
+         * and report that the key does not exist. */
+        status = psa_unregister_read(slot);
+
+        PSA_THREADING_CHK_RET(mbedtls_mutex_unlock(
+                                  &mbedtls_threading_key_slot_mutex));
+        return (status == PSA_SUCCESS) ? PSA_ERROR_INVALID_HANDLE : status;
+    }
+#endif
+    /* Set the key slot containing the key description's state to
+     * PENDING_DELETION. This stops new operations from registering
+     * to read the slot. Current readers can safely continue to access
+     * the key within the slot; the last registered reader will
+     * automatically wipe the slot when they call psa_unregister_read().
+     * If the key is persistent, we can now delete the copy of the key
+     * from memory. If the key is opaque, we require the driver to
+     * deal with the deletion. */
+    overall_status = psa_key_slot_state_transition(slot, PSA_SLOT_FULL,
+                                                   PSA_SLOT_PENDING_DELETION);
+
+    if (overall_status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    if (PSA_KEY_LIFETIME_IS_READ_ONLY(slot->attr.lifetime)) {
+        /* Refuse the destruction of a read-only key (which may or may not work
+         * if we attempt it, depending on whether the key is merely read-only
+         * by policy or actually physically read-only).
+         * Just do the best we can, which is to wipe the copy in memory
+         * (done in this function's cleanup code). */
+        overall_status = PSA_ERROR_NOT_PERMITTED;
+        goto exit;
+    }
+
+#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
+    driver = psa_get_se_driver_entry(slot->attr.lifetime);
+    if (driver != NULL) {
+        /* For a key in a secure element, we need to do three things:
+         * remove the key file in internal storage, destroy the
+         * key inside the secure element, and update the driver's
+         * persistent data. Start a transaction that will encompass these
+         * three actions. */
+        psa_crypto_prepare_transaction(PSA_CRYPTO_TRANSACTION_DESTROY_KEY);
+        psa_crypto_transaction.key.lifetime = slot->attr.lifetime;
+        psa_crypto_transaction.key.slot = psa_key_slot_get_slot_number(slot);
+        psa_crypto_transaction.key.id = slot->attr.id;
+        status = psa_crypto_save_transaction();
+        if (status != PSA_SUCCESS) {
+            (void) psa_crypto_stop_transaction();
+            /* We should still try to destroy the key in the secure
+             * element and the key metadata in storage. This is especially
+             * important if the error is that the storage is full.
+             * But how to do it exactly without risking an inconsistent
+             * state after a reset?
+             * https://github.com/ARMmbed/mbed-crypto/issues/215
+             */
+            overall_status = status;
+            goto exit;
+        }
+
+        status = psa_destroy_se_key(driver,
+                                    psa_key_slot_get_slot_number(slot));
+        if (overall_status == PSA_SUCCESS) {
+            overall_status = status;
+        }
+    }
+#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
+
+#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
+    if (!PSA_KEY_LIFETIME_IS_VOLATILE(slot->attr.lifetime)) {
+        /* Destroy the copy of the persistent key from storage.
+         * The slot will still hold a copy of the key until the last reader
+         * unregisters. */
+        status = psa_destroy_persistent_key(slot->attr.id);
+        if (overall_status == PSA_SUCCESS) {
+            overall_status = status;
+        }
+    }
+#endif /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */
+
+#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
+    if (driver != NULL) {
+        status = psa_save_se_persistent_data(driver);
+        if (overall_status == PSA_SUCCESS) {
+            overall_status = status;
+        }
+        status = psa_crypto_stop_transaction();
+        if (overall_status == PSA_SUCCESS) {
+            overall_status = status;
+        }
+    }
+#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
+
+exit:
+    /* Unregister from reading the slot. If we are the last active reader
+     * then this will wipe the slot. */
+    status = psa_unregister_read(slot);
+    /* Prioritize CORRUPTION_DETECTED from unregistering over
+     * a storage error. */
+    if (status != PSA_SUCCESS) {
+        overall_status = status;
+    }
+
+#if defined(MBEDTLS_THREADING_C)
+    /* Don't overwrite existing errors if the unlock fails. */
+    status = overall_status;
+    PSA_THREADING_CHK_RET(mbedtls_mutex_unlock(
+                              &mbedtls_threading_key_slot_mutex));
+#endif
+
+    return overall_status;
+}
+
+/** Retrieve all the publicly-accessible attributes of a key.
+ */
+psa_status_t psa_get_key_attributes(mbedtls_svc_key_id_t key,
+                                    psa_key_attributes_t *attributes)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+
+    psa_reset_key_attributes(attributes);
+
+    status = psa_get_and_lock_key_slot_with_policy(key, &slot, 0, 0);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    *attributes = slot->attr;
+
+#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
+    if (psa_get_se_driver_entry(slot->attr.lifetime) != NULL) {
+        psa_set_key_slot_number(attributes,
+                                psa_key_slot_get_slot_number(slot));
+    }
+#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
+
+    return psa_unregister_read_under_mutex(slot);
+}
+
+#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
+psa_status_t psa_get_key_slot_number(
+    const psa_key_attributes_t *attributes,
+    psa_key_slot_number_t *slot_number)
+{
+    if (attributes->has_slot_number) {
+        *slot_number = attributes->slot_number;
+        return PSA_SUCCESS;
+    } else {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+}
+#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
+
+static psa_status_t psa_export_key_buffer_internal(const uint8_t *key_buffer,
+                                                   size_t key_buffer_size,
+                                                   uint8_t *data,
+                                                   size_t data_size,
+                                                   size_t *data_length)
+{
+    if (key_buffer_size > data_size) {
+        return PSA_ERROR_BUFFER_TOO_SMALL;
+    }
+    memcpy(data, key_buffer, key_buffer_size);
+    memset(data + key_buffer_size, 0,
+           data_size - key_buffer_size);
+    *data_length = key_buffer_size;
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_export_key_internal(
+    const psa_key_attributes_t *attributes,
+    const uint8_t *key_buffer, size_t key_buffer_size,
+    uint8_t *data, size_t data_size, size_t *data_length)
+{
+    psa_key_type_t type = attributes->type;
+
+    if (key_type_is_raw_bytes(type) ||
+        PSA_KEY_TYPE_IS_RSA(type)   ||
+        PSA_KEY_TYPE_IS_ECC(type)   ||
+        PSA_KEY_TYPE_IS_DH(type)) {
+        return psa_export_key_buffer_internal(
+            key_buffer, key_buffer_size,
+            data, data_size, data_length);
+    } else {
+        /* This shouldn't happen in the reference implementation, but
+           it is valid for a special-purpose implementation to omit
+           support for exporting certain key types. */
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+}
+
+psa_status_t psa_export_key(mbedtls_svc_key_id_t key,
+                            uint8_t *data_external,
+                            size_t data_size,
+                            size_t *data_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+    LOCAL_OUTPUT_DECLARE(data_external, data);
+
+    /* Reject a zero-length output buffer now, since this can never be a
+     * valid key representation. This way we know that data must be a valid
+     * pointer and we can do things like memset(data, ..., data_size). */
+    if (data_size == 0) {
+        return PSA_ERROR_BUFFER_TOO_SMALL;
+    }
+
+    /* Set the key to empty now, so that even when there are errors, we always
+     * set data_length to a value between 0 and data_size. On error, setting
+     * the key to empty is a good choice because an empty key representation is
+     * unlikely to be accepted anywhere. */
+    *data_length = 0;
+
+    /* Export requires the EXPORT flag. There is an exception for public keys,
+     * which don't require any flag, but
+     * psa_get_and_lock_key_slot_with_policy() takes care of this.
+     */
+    status = psa_get_and_lock_key_slot_with_policy(key, &slot,
+                                                   PSA_KEY_USAGE_EXPORT, 0);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    LOCAL_OUTPUT_ALLOC(data_external, data_size, data);
+
+    status = psa_driver_wrapper_export_key(&slot->attr,
+                                           slot->key.data, slot->key.bytes,
+                                           data, data_size, data_length);
+
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    LOCAL_OUTPUT_FREE(data_external, data);
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+psa_status_t psa_export_public_key_internal(
+    const psa_key_attributes_t *attributes,
+    const uint8_t *key_buffer,
+    size_t key_buffer_size,
+    uint8_t *data,
+    size_t data_size,
+    size_t *data_length)
+{
+    psa_key_type_t type = attributes->type;
+
+    if (PSA_KEY_TYPE_IS_PUBLIC_KEY(type) &&
+        (PSA_KEY_TYPE_IS_RSA(type) || PSA_KEY_TYPE_IS_ECC(type) ||
+         PSA_KEY_TYPE_IS_DH(type))) {
+        /* Exporting public -> public */
+        return psa_export_key_buffer_internal(
+            key_buffer, key_buffer_size,
+            data, data_size, data_length);
+    } else if (PSA_KEY_TYPE_IS_RSA(type)) {
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR_EXPORT) || \
+        defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY)
+        return mbedtls_psa_rsa_export_public_key(attributes,
+                                                 key_buffer,
+                                                 key_buffer_size,
+                                                 data,
+                                                 data_size,
+                                                 data_length);
+#else
+        /* We don't know how to convert a private RSA key to public. */
+        return PSA_ERROR_NOT_SUPPORTED;
+#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR_EXPORT) ||
+        * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */
+    } else if (PSA_KEY_TYPE_IS_ECC(type)) {
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_EXPORT) || \
+        defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY)
+        return mbedtls_psa_ecp_export_public_key(attributes,
+                                                 key_buffer,
+                                                 key_buffer_size,
+                                                 data,
+                                                 data_size,
+                                                 data_length);
+#else
+        /* We don't know how to convert a private ECC key to public */
+        return PSA_ERROR_NOT_SUPPORTED;
+#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_EXPORT) ||
+        * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) */
+    } else if (PSA_KEY_TYPE_IS_DH(type)) {
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_KEY_PAIR_EXPORT) || \
+        defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_PUBLIC_KEY)
+        return mbedtls_psa_ffdh_export_public_key(attributes,
+                                                  key_buffer,
+                                                  key_buffer_size,
+                                                  data, data_size,
+                                                  data_length);
+#else
+        return PSA_ERROR_NOT_SUPPORTED;
+#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_KEY_PAIR_EXPORT) ||
+        * defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_PUBLIC_KEY) */
+    } else {
+        (void) key_buffer;
+        (void) key_buffer_size;
+        (void) data;
+        (void) data_size;
+        (void) data_length;
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+}
+
+psa_status_t psa_export_public_key(mbedtls_svc_key_id_t key,
+                                   uint8_t *data_external,
+                                   size_t data_size,
+                                   size_t *data_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+
+    LOCAL_OUTPUT_DECLARE(data_external, data);
+
+    /* Reject a zero-length output buffer now, since this can never be a
+     * valid key representation. This way we know that data must be a valid
+     * pointer and we can do things like memset(data, ..., data_size). */
+    if (data_size == 0) {
+        return PSA_ERROR_BUFFER_TOO_SMALL;
+    }
+
+    /* Set the key to empty now, so that even when there are errors, we always
+     * set data_length to a value between 0 and data_size. On error, setting
+     * the key to empty is a good choice because an empty key representation is
+     * unlikely to be accepted anywhere. */
+    *data_length = 0;
+
+    /* Exporting a public key doesn't require a usage flag. */
+    status = psa_get_and_lock_key_slot_with_policy(key, &slot, 0, 0);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    LOCAL_OUTPUT_ALLOC(data_external, data_size, data);
+
+    if (!PSA_KEY_TYPE_IS_ASYMMETRIC(slot->attr.type)) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    status = psa_driver_wrapper_export_public_key(
+        &slot->attr, slot->key.data, slot->key.bytes,
+        data, data_size, data_length);
+
+exit:
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    LOCAL_OUTPUT_FREE(data_external, data);
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+/** Validate that a key policy is internally well-formed.
+ *
+ * This function only rejects invalid policies. It does not validate the
+ * consistency of the policy with respect to other attributes of the key
+ * such as the key type.
+ */
+static psa_status_t psa_validate_key_policy(const psa_key_policy_t *policy)
+{
+    if ((policy->usage & ~(PSA_KEY_USAGE_EXPORT |
+                           PSA_KEY_USAGE_COPY |
+                           PSA_KEY_USAGE_ENCRYPT |
+                           PSA_KEY_USAGE_DECRYPT |
+                           PSA_KEY_USAGE_SIGN_MESSAGE |
+                           PSA_KEY_USAGE_VERIFY_MESSAGE |
+                           PSA_KEY_USAGE_SIGN_HASH |
+                           PSA_KEY_USAGE_VERIFY_HASH |
+                           PSA_KEY_USAGE_VERIFY_DERIVATION |
+                           PSA_KEY_USAGE_DERIVE)) != 0) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    return PSA_SUCCESS;
+}
+
+/** Validate the internal consistency of key attributes.
+ *
+ * This function only rejects invalid attribute values. If does not
+ * validate the consistency of the attributes with any key data that may
+ * be involved in the creation of the key.
+ *
+ * Call this function early in the key creation process.
+ *
+ * \param[in] attributes    Key attributes for the new key.
+ * \param[out] p_drv        On any return, the driver for the key, if any.
+ *                          NULL for a transparent key.
+ *
+ */
+static psa_status_t psa_validate_key_attributes(
+    const psa_key_attributes_t *attributes,
+    psa_se_drv_table_entry_t **p_drv)
+{
+    psa_status_t status = PSA_ERROR_INVALID_ARGUMENT;
+    psa_key_lifetime_t lifetime = psa_get_key_lifetime(attributes);
+    mbedtls_svc_key_id_t key = psa_get_key_id(attributes);
+
+    status = psa_validate_key_location(lifetime, p_drv);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    status = psa_validate_key_persistence(lifetime);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    if (PSA_KEY_LIFETIME_IS_VOLATILE(lifetime)) {
+        if (MBEDTLS_SVC_KEY_ID_GET_KEY_ID(key) != 0) {
+            return PSA_ERROR_INVALID_ARGUMENT;
+        }
+    } else {
+        if (!psa_is_valid_key_id(psa_get_key_id(attributes), 0)) {
+            return PSA_ERROR_INVALID_ARGUMENT;
+        }
+    }
+
+    status = psa_validate_key_policy(&attributes->policy);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    /* Refuse to create overly large keys.
+     * Note that this doesn't trigger on import if the attributes don't
+     * explicitly specify a size (so psa_get_key_bits returns 0), so
+     * psa_import_key() needs its own checks. */
+    if (psa_get_key_bits(attributes) > PSA_MAX_KEY_BITS) {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    return PSA_SUCCESS;
+}
+
+/** Prepare a key slot to receive key material.
+ *
+ * This function allocates a key slot and sets its metadata.
+ *
+ * If this function fails, call psa_fail_key_creation().
+ *
+ * This function is intended to be used as follows:
+ * -# Call psa_start_key_creation() to allocate a key slot, prepare
+ *    it with the specified attributes, and in case of a volatile key assign it
+ *    a volatile key identifier.
+ * -# Populate the slot with the key material.
+ * -# Call psa_finish_key_creation() to finalize the creation of the slot.
+ * In case of failure at any step, stop the sequence and call
+ * psa_fail_key_creation().
+ *
+ * On success, the key slot's state is PSA_SLOT_FILLING.
+ * It is the responsibility of the caller to change the slot's state to
+ * PSA_SLOT_EMPTY/FULL once key creation has finished.
+ *
+ * \param method            An identification of the calling function.
+ * \param[in] attributes    Key attributes for the new key.
+ * \param[out] p_slot       On success, a pointer to the prepared slot.
+ * \param[out] p_drv        On any return, the driver for the key, if any.
+ *                          NULL for a transparent key.
+ *
+ * \retval #PSA_SUCCESS
+ *         The key slot is ready to receive key material.
+ * \return If this function fails, the key slot is an invalid state.
+ *         You must call psa_fail_key_creation() to wipe and free the slot.
+ */
+static psa_status_t psa_start_key_creation(
+    psa_key_creation_method_t method,
+    const psa_key_attributes_t *attributes,
+    psa_key_slot_t **p_slot,
+    psa_se_drv_table_entry_t **p_drv)
+{
+    psa_status_t status;
+
+    (void) method;
+    *p_drv = NULL;
+
+    status = psa_validate_key_attributes(attributes, p_drv);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    int key_is_volatile = PSA_KEY_LIFETIME_IS_VOLATILE(attributes->lifetime);
+    psa_key_id_t volatile_key_id;
+
+#if defined(MBEDTLS_THREADING_C)
+    PSA_THREADING_CHK_RET(mbedtls_mutex_lock(
+                              &mbedtls_threading_key_slot_mutex));
+#endif
+    status = psa_reserve_free_key_slot(
+        key_is_volatile ? &volatile_key_id : NULL,
+        p_slot);
+#if defined(MBEDTLS_THREADING_C)
+    PSA_THREADING_CHK_RET(mbedtls_mutex_unlock(
+                              &mbedtls_threading_key_slot_mutex));
+#endif
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+    psa_key_slot_t *slot = *p_slot;
+
+    /* We're storing the declared bit-size of the key. It's up to each
+     * creation mechanism to verify that this information is correct.
+     * It's automatically correct for mechanisms that use the bit-size as
+     * an input (generate, device) but not for those where the bit-size
+     * is optional (import, copy). In case of a volatile key, assign it the
+     * volatile key identifier associated to the slot returned to contain its
+     * definition. */
+
+    slot->attr = *attributes;
+    if (key_is_volatile) {
+#if !defined(MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER)
+        slot->attr.id = volatile_key_id;
+#else
+        slot->attr.id.key_id = volatile_key_id;
+#endif
+    }
+
+#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
+    /* For a key in a secure element, we need to do three things
+     * when creating or registering a persistent key:
+     * create the key file in internal storage, create the
+     * key inside the secure element, and update the driver's
+     * persistent data. This is done by starting a transaction that will
+     * encompass these three actions.
+     * For registering a volatile key, we just need to find an appropriate
+     * slot number inside the SE. Since the key is designated volatile, creating
+     * a transaction is not required. */
+    /* The first thing to do is to find a slot number for the new key.
+     * We save the slot number in persistent storage as part of the
+     * transaction data. It will be needed to recover if the power
+     * fails during the key creation process, to clean up on the secure
+     * element side after restarting. Obtaining a slot number from the
+     * secure element driver updates its persistent state, but we do not yet
+     * save the driver's persistent state, so that if the power fails,
+     * we can roll back to a state where the key doesn't exist. */
+    if (*p_drv != NULL) {
+        psa_key_slot_number_t slot_number;
+        status = psa_find_se_slot_for_key(attributes, method, *p_drv,
+                                          &slot_number);
+        if (status != PSA_SUCCESS) {
+            return status;
+        }
+
+        if (!PSA_KEY_LIFETIME_IS_VOLATILE(attributes->lifetime)) {
+            psa_crypto_prepare_transaction(PSA_CRYPTO_TRANSACTION_CREATE_KEY);
+            psa_crypto_transaction.key.lifetime = slot->attr.lifetime;
+            psa_crypto_transaction.key.slot = slot_number;
+            psa_crypto_transaction.key.id = slot->attr.id;
+            status = psa_crypto_save_transaction();
+            if (status != PSA_SUCCESS) {
+                (void) psa_crypto_stop_transaction();
+                return status;
+            }
+        }
+
+        status = psa_copy_key_material_into_slot(
+            slot, (uint8_t *) (&slot_number), sizeof(slot_number));
+        if (status != PSA_SUCCESS) {
+            return status;
+        }
+    }
+
+    if (*p_drv == NULL && method == PSA_KEY_CREATION_REGISTER) {
+        /* Key registration only makes sense with a secure element. */
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
+
+    return PSA_SUCCESS;
+}
+
+/** Finalize the creation of a key once its key material has been set.
+ *
+ * This entails writing the key to persistent storage.
+ *
+ * If this function fails, call psa_fail_key_creation().
+ * See the documentation of psa_start_key_creation() for the intended use
+ * of this function.
+ *
+ * If the finalization succeeds, the function sets the key slot's state to
+ * PSA_SLOT_FULL, and the key slot can no longer be accessed as part of the
+ * key creation process.
+ *
+ * \param[in,out] slot  Pointer to the slot with key material.
+ * \param[in] driver    The secure element driver for the key,
+ *                      or NULL for a transparent key.
+ * \param[out] key      On success, identifier of the key. Note that the
+ *                      key identifier is also stored in the key slot.
+ *
+ * \retval #PSA_SUCCESS
+ *         The key was successfully created.
+ * \retval #PSA_ERROR_INSUFFICIENT_MEMORY \emptydescription
+ * \retval #PSA_ERROR_INSUFFICIENT_STORAGE \emptydescription
+ * \retval #PSA_ERROR_ALREADY_EXISTS \emptydescription
+ * \retval #PSA_ERROR_DATA_INVALID \emptydescription
+ * \retval #PSA_ERROR_DATA_CORRUPT \emptydescription
+ * \retval #PSA_ERROR_STORAGE_FAILURE \emptydescription
+ *
+ * \return If this function fails, the key slot is an invalid state.
+ *         You must call psa_fail_key_creation() to wipe and free the slot.
+ */
+static psa_status_t psa_finish_key_creation(
+    psa_key_slot_t *slot,
+    psa_se_drv_table_entry_t *driver,
+    mbedtls_svc_key_id_t *key)
+{
+    psa_status_t status = PSA_SUCCESS;
+    (void) slot;
+    (void) driver;
+
+#if defined(MBEDTLS_THREADING_C)
+    PSA_THREADING_CHK_RET(mbedtls_mutex_lock(
+                              &mbedtls_threading_key_slot_mutex));
+#endif
+
+#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
+    if (!PSA_KEY_LIFETIME_IS_VOLATILE(slot->attr.lifetime)) {
+#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
+        if (driver != NULL) {
+            psa_se_key_data_storage_t data;
+            psa_key_slot_number_t slot_number =
+                psa_key_slot_get_slot_number(slot);
+
+            MBEDTLS_STATIC_ASSERT(sizeof(slot_number) ==
+                                  sizeof(data.slot_number),
+                                  "Slot number size does not match psa_se_key_data_storage_t");
+
+            memcpy(&data.slot_number, &slot_number, sizeof(slot_number));
+            status = psa_save_persistent_key(&slot->attr,
+                                             (uint8_t *) &data,
+                                             sizeof(data));
+        } else
+#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
+        {
+            /* Key material is saved in export representation in the slot, so
+             * just pass the slot buffer for storage. */
+            status = psa_save_persistent_key(&slot->attr,
+                                             slot->key.data,
+                                             slot->key.bytes);
+        }
+    }
+#endif /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */
+
+#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
+    /* Finish the transaction for a key creation. This does not
+     * happen when registering an existing key. Detect this case
+     * by checking whether a transaction is in progress (actual
+     * creation of a persistent key in a secure element requires a transaction,
+     * but registration or volatile key creation doesn't use one). */
+    if (driver != NULL &&
+        psa_crypto_transaction.unknown.type == PSA_CRYPTO_TRANSACTION_CREATE_KEY) {
+        status = psa_save_se_persistent_data(driver);
+        if (status != PSA_SUCCESS) {
+            psa_destroy_persistent_key(slot->attr.id);
+
+#if defined(MBEDTLS_THREADING_C)
+            PSA_THREADING_CHK_RET(mbedtls_mutex_unlock(
+                                      &mbedtls_threading_key_slot_mutex));
+#endif
+            return status;
+        }
+        status = psa_crypto_stop_transaction();
+    }
+#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
+
+    if (status == PSA_SUCCESS) {
+        *key = slot->attr.id;
+        status = psa_key_slot_state_transition(slot, PSA_SLOT_FILLING,
+                                               PSA_SLOT_FULL);
+        if (status != PSA_SUCCESS) {
+            *key = MBEDTLS_SVC_KEY_ID_INIT;
+        }
+    }
+
+#if defined(MBEDTLS_THREADING_C)
+    PSA_THREADING_CHK_RET(mbedtls_mutex_unlock(
+                              &mbedtls_threading_key_slot_mutex));
+#endif
+    return status;
+}
+
+/** Abort the creation of a key.
+ *
+ * You may call this function after calling psa_start_key_creation(),
+ * or after psa_finish_key_creation() fails. In other circumstances, this
+ * function may not clean up persistent storage.
+ * See the documentation of psa_start_key_creation() for the intended use
+ * of this function. Sets the slot's state to PSA_SLOT_EMPTY.
+ *
+ * \param[in,out] slot  Pointer to the slot with key material.
+ * \param[in] driver    The secure element driver for the key,
+ *                      or NULL for a transparent key.
+ */
+static void psa_fail_key_creation(psa_key_slot_t *slot,
+                                  psa_se_drv_table_entry_t *driver)
+{
+    (void) driver;
+
+    if (slot == NULL) {
+        return;
+    }
+
+#if defined(MBEDTLS_THREADING_C)
+    /* If the lock operation fails we still wipe the slot.
+     * Operations will no longer work after a failed lock,
+     * but we still need to wipe the slot of confidential data. */
+    mbedtls_mutex_lock(&mbedtls_threading_key_slot_mutex);
+#endif
+
+#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
+    /* TODO: If the key has already been created in the secure
+     * element, and the failure happened later (when saving metadata
+     * to internal storage), we need to destroy the key in the secure
+     * element.
+     * https://github.com/ARMmbed/mbed-crypto/issues/217
+     */
+
+    /* Abort the ongoing transaction if any (there may not be one if
+     * the creation process failed before starting one, or if the
+     * key creation is a registration of a key in a secure element).
+     * Earlier functions must already have done what it takes to undo any
+     * partial creation. All that's left is to update the transaction data
+     * itself. */
+    (void) psa_crypto_stop_transaction();
+#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
+
+    psa_wipe_key_slot(slot);
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_unlock(&mbedtls_threading_key_slot_mutex);
+#endif
+}
+
+/** Validate optional attributes during key creation.
+ *
+ * Some key attributes are optional during key creation. If they are
+ * specified in the attributes structure, check that they are consistent
+ * with the data in the slot.
+ *
+ * This function should be called near the end of key creation, after
+ * the slot in memory is fully populated but before saving persistent data.
+ */
+static psa_status_t psa_validate_optional_attributes(
+    const psa_key_slot_t *slot,
+    const psa_key_attributes_t *attributes)
+{
+    if (attributes->type != 0) {
+        if (attributes->type != slot->attr.type) {
+            return PSA_ERROR_INVALID_ARGUMENT;
+        }
+    }
+
+    if (attributes->bits != 0) {
+        if (attributes->bits != slot->attr.bits) {
+            return PSA_ERROR_INVALID_ARGUMENT;
+        }
+    }
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_import_key(const psa_key_attributes_t *attributes,
+                            const uint8_t *data_external,
+                            size_t data_length,
+                            mbedtls_svc_key_id_t *key)
+{
+    psa_status_t status;
+    LOCAL_INPUT_DECLARE(data_external, data);
+    psa_key_slot_t *slot = NULL;
+    psa_se_drv_table_entry_t *driver = NULL;
+    size_t bits;
+    size_t storage_size = data_length;
+
+    *key = MBEDTLS_SVC_KEY_ID_INIT;
+
+    /* Reject zero-length symmetric keys (including raw data key objects).
+     * This also rejects any key which might be encoded as an empty string,
+     * which is never valid. */
+    if (data_length == 0) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    /* Ensure that the bytes-to-bits conversion cannot overflow. */
+    if (data_length > SIZE_MAX / 8) {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    LOCAL_INPUT_ALLOC(data_external, data_length, data);
+
+    status = psa_start_key_creation(PSA_KEY_CREATION_IMPORT, attributes,
+                                    &slot, &driver);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    /* In the case of a transparent key or an opaque key stored in local
+     * storage ( thus not in the case of importing a key in a secure element
+     * with storage ( MBEDTLS_PSA_CRYPTO_SE_C ) ),we have to allocate a
+     * buffer to hold the imported key material. */
+    if (slot->key.data == NULL) {
+        if (psa_key_lifetime_is_external(attributes->lifetime)) {
+            status = psa_driver_wrapper_get_key_buffer_size_from_key_data(
+                attributes, data, data_length, &storage_size);
+            if (status != PSA_SUCCESS) {
+                goto exit;
+            }
+        }
+        status = psa_allocate_buffer_to_slot(slot, storage_size);
+        if (status != PSA_SUCCESS) {
+            goto exit;
+        }
+    }
+
+    bits = slot->attr.bits;
+    status = psa_driver_wrapper_import_key(attributes,
+                                           data, data_length,
+                                           slot->key.data,
+                                           slot->key.bytes,
+                                           &slot->key.bytes, &bits);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    if (slot->attr.bits == 0) {
+        slot->attr.bits = (psa_key_bits_t) bits;
+    } else if (bits != slot->attr.bits) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    /* Enforce a size limit, and in particular ensure that the bit
+     * size fits in its representation type.*/
+    if (bits > PSA_MAX_KEY_BITS) {
+        status = PSA_ERROR_NOT_SUPPORTED;
+        goto exit;
+    }
+    status = psa_validate_optional_attributes(slot, attributes);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = psa_finish_key_creation(slot, driver, key);
+exit:
+    LOCAL_INPUT_FREE(data_external, data);
+    if (status != PSA_SUCCESS) {
+        psa_fail_key_creation(slot, driver);
+    }
+
+    return status;
+}
+
+#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
+psa_status_t mbedtls_psa_register_se_key(
+    const psa_key_attributes_t *attributes)
+{
+    psa_status_t status;
+    psa_key_slot_t *slot = NULL;
+    psa_se_drv_table_entry_t *driver = NULL;
+    mbedtls_svc_key_id_t key = MBEDTLS_SVC_KEY_ID_INIT;
+
+    /* Leaving attributes unspecified is not currently supported.
+     * It could make sense to query the key type and size from the
+     * secure element, but not all secure elements support this
+     * and the driver HAL doesn't currently support it. */
+    if (psa_get_key_type(attributes) == PSA_KEY_TYPE_NONE) {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+    if (psa_get_key_bits(attributes) == 0) {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    /* Not usable with volatile keys, even with an appropriate location,
+     * due to the API design.
+     * https://github.com/Mbed-TLS/mbedtls/issues/9253
+     */
+    if (PSA_KEY_LIFETIME_IS_VOLATILE(psa_get_key_lifetime(attributes))) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    status = psa_start_key_creation(PSA_KEY_CREATION_REGISTER, attributes,
+                                    &slot, &driver);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = psa_finish_key_creation(slot, driver, &key);
+
+exit:
+    if (status != PSA_SUCCESS) {
+        psa_fail_key_creation(slot, driver);
+    }
+
+    /* Registration doesn't keep the key in RAM. */
+    psa_close_key(key);
+    return status;
+}
+#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
+
+psa_status_t psa_copy_key(mbedtls_svc_key_id_t source_key,
+                          const psa_key_attributes_t *specified_attributes,
+                          mbedtls_svc_key_id_t *target_key)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *source_slot = NULL;
+    psa_key_slot_t *target_slot = NULL;
+    psa_key_attributes_t actual_attributes = *specified_attributes;
+    psa_se_drv_table_entry_t *driver = NULL;
+    size_t storage_size = 0;
+
+    *target_key = MBEDTLS_SVC_KEY_ID_INIT;
+
+    status = psa_get_and_lock_key_slot_with_policy(
+        source_key, &source_slot, PSA_KEY_USAGE_COPY, 0);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = psa_validate_optional_attributes(source_slot,
+                                              specified_attributes);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    /* The target key type and number of bits have been validated by
+     * psa_validate_optional_attributes() to be either equal to zero or
+     * equal to the ones of the source key. So it is safe to inherit
+     * them from the source key now."
+     * */
+    actual_attributes.bits = source_slot->attr.bits;
+    actual_attributes.type = source_slot->attr.type;
+
+
+    status = psa_restrict_key_policy(source_slot->attr.type,
+                                     &actual_attributes.policy,
+                                     &source_slot->attr.policy);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = psa_start_key_creation(PSA_KEY_CREATION_COPY, &actual_attributes,
+                                    &target_slot, &driver);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+    if (PSA_KEY_LIFETIME_GET_LOCATION(target_slot->attr.lifetime) !=
+        PSA_KEY_LIFETIME_GET_LOCATION(source_slot->attr.lifetime)) {
+        /*
+         * If the source and target keys are stored in different locations,
+         * the source key would need to be exported as plaintext and re-imported
+         * in the other location. This has security implications which have not
+         * been fully mapped. For now, this can be achieved through
+         * appropriate API invocations from the application, if needed.
+         * */
+        status = PSA_ERROR_NOT_SUPPORTED;
+        goto exit;
+    }
+    /*
+     * When the source and target keys are within the same location,
+     * - For transparent keys it is a blind copy without any driver invocation,
+     * - For opaque keys this translates to an invocation of the drivers'
+     *   copy_key entry point through the dispatch layer.
+     * */
+    if (psa_key_lifetime_is_external(actual_attributes.lifetime)) {
+        status = psa_driver_wrapper_get_key_buffer_size(&actual_attributes,
+                                                        &storage_size);
+        if (status != PSA_SUCCESS) {
+            goto exit;
+        }
+
+        status = psa_allocate_buffer_to_slot(target_slot, storage_size);
+        if (status != PSA_SUCCESS) {
+            goto exit;
+        }
+
+        status = psa_driver_wrapper_copy_key(&actual_attributes,
+                                             source_slot->key.data,
+                                             source_slot->key.bytes,
+                                             target_slot->key.data,
+                                             target_slot->key.bytes,
+                                             &target_slot->key.bytes);
+        if (status != PSA_SUCCESS) {
+            goto exit;
+        }
+    } else {
+        status = psa_copy_key_material_into_slot(target_slot,
+                                                 source_slot->key.data,
+                                                 source_slot->key.bytes);
+        if (status != PSA_SUCCESS) {
+            goto exit;
+        }
+    }
+    status = psa_finish_key_creation(target_slot, driver, target_key);
+exit:
+    if (status != PSA_SUCCESS) {
+        psa_fail_key_creation(target_slot, driver);
+    }
+
+    unlock_status = psa_unregister_read_under_mutex(source_slot);
+
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+
+
+/****************************************************************/
+/* Message digests */
+/****************************************************************/
+
+psa_status_t psa_hash_abort(psa_hash_operation_t *operation)
+{
+    /* Aborting a non-active operation is allowed */
+    if (operation->id == 0) {
+        return PSA_SUCCESS;
+    }
+
+    psa_status_t status = psa_driver_wrapper_hash_abort(operation);
+    operation->id = 0;
+
+    return status;
+}
+
+psa_status_t psa_hash_setup(psa_hash_operation_t *operation,
+                            psa_algorithm_t alg)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    /* A context must be freshly initialized before it can be set up. */
+    if (operation->id != 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (!PSA_ALG_IS_HASH(alg)) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    /* Ensure all of the context is zeroized, since PSA_HASH_OPERATION_INIT only
+     * directly zeroes the int-sized dummy member of the context union. */
+    memset(&operation->ctx, 0, sizeof(operation->ctx));
+
+    status = psa_driver_wrapper_hash_setup(operation, alg);
+
+exit:
+    if (status != PSA_SUCCESS) {
+        psa_hash_abort(operation);
+    }
+
+    return status;
+}
+
+psa_status_t psa_hash_update(psa_hash_operation_t *operation,
+                             const uint8_t *input_external,
+                             size_t input_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_INPUT_DECLARE(input_external, input);
+
+    if (operation->id == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    /* Don't require hash implementations to behave correctly on a
+     * zero-length input, which may have an invalid pointer. */
+    if (input_length == 0) {
+        return PSA_SUCCESS;
+    }
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    status = psa_driver_wrapper_hash_update(operation, input, input_length);
+
+exit:
+    if (status != PSA_SUCCESS) {
+        psa_hash_abort(operation);
+    }
+
+    LOCAL_INPUT_FREE(input_external, input);
+    return status;
+}
+
+static psa_status_t psa_hash_finish_internal(psa_hash_operation_t *operation,
+                                             uint8_t *hash,
+                                             size_t hash_size,
+                                             size_t *hash_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    *hash_length = 0;
+    if (operation->id == 0) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    status = psa_driver_wrapper_hash_finish(
+        operation, hash, hash_size, hash_length);
+    psa_hash_abort(operation);
+
+    return status;
+}
+
+psa_status_t psa_hash_finish(psa_hash_operation_t *operation,
+                             uint8_t *hash_external,
+                             size_t hash_size,
+                             size_t *hash_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_OUTPUT_DECLARE(hash_external, hash);
+
+    LOCAL_OUTPUT_ALLOC(hash_external, hash_size, hash);
+    status = psa_hash_finish_internal(operation, hash, hash_size, hash_length);
+
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+    LOCAL_OUTPUT_FREE(hash_external, hash);
+    return status;
+}
+
+psa_status_t psa_hash_verify(psa_hash_operation_t *operation,
+                             const uint8_t *hash_external,
+                             size_t hash_length)
+{
+    uint8_t actual_hash[PSA_HASH_MAX_SIZE];
+    size_t actual_hash_length;
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_INPUT_DECLARE(hash_external, hash);
+
+    status = psa_hash_finish_internal(
+        operation,
+        actual_hash, sizeof(actual_hash),
+        &actual_hash_length);
+
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    if (actual_hash_length != hash_length) {
+        status = PSA_ERROR_INVALID_SIGNATURE;
+        goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(hash_external, hash_length, hash);
+    if (mbedtls_ct_memcmp(hash, actual_hash, actual_hash_length) != 0) {
+        status = PSA_ERROR_INVALID_SIGNATURE;
+    }
+
+exit:
+    mbedtls_platform_zeroize(actual_hash, sizeof(actual_hash));
+    if (status != PSA_SUCCESS) {
+        psa_hash_abort(operation);
+    }
+    LOCAL_INPUT_FREE(hash_external, hash);
+    return status;
+}
+
+psa_status_t psa_hash_compute(psa_algorithm_t alg,
+                              const uint8_t *input_external, size_t input_length,
+                              uint8_t *hash_external, size_t hash_size,
+                              size_t *hash_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_OUTPUT_DECLARE(hash_external, hash);
+
+    *hash_length = 0;
+    if (!PSA_ALG_IS_HASH(alg)) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    LOCAL_OUTPUT_ALLOC(hash_external, hash_size, hash);
+    status = psa_driver_wrapper_hash_compute(alg, input, input_length,
+                                             hash, hash_size, hash_length);
+
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+    LOCAL_INPUT_FREE(input_external, input);
+    LOCAL_OUTPUT_FREE(hash_external, hash);
+    return status;
+}
+
+psa_status_t psa_hash_compare(psa_algorithm_t alg,
+                              const uint8_t *input_external, size_t input_length,
+                              const uint8_t *hash_external, size_t hash_length)
+{
+    uint8_t actual_hash[PSA_HASH_MAX_SIZE];
+    size_t actual_hash_length;
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_INPUT_DECLARE(hash_external, hash);
+
+    if (!PSA_ALG_IS_HASH(alg)) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        return status;
+    }
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    status = psa_driver_wrapper_hash_compute(
+        alg, input, input_length,
+        actual_hash, sizeof(actual_hash),
+        &actual_hash_length);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+    if (actual_hash_length != hash_length) {
+        status = PSA_ERROR_INVALID_SIGNATURE;
+        goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(hash_external, hash_length, hash);
+    if (mbedtls_ct_memcmp(hash, actual_hash, actual_hash_length) != 0) {
+        status = PSA_ERROR_INVALID_SIGNATURE;
+    }
+
+exit:
+    mbedtls_platform_zeroize(actual_hash, sizeof(actual_hash));
+
+    LOCAL_INPUT_FREE(input_external, input);
+    LOCAL_INPUT_FREE(hash_external, hash);
+
+    return status;
+}
+
+psa_status_t psa_hash_clone(const psa_hash_operation_t *source_operation,
+                            psa_hash_operation_t *target_operation)
+{
+    if (source_operation->id == 0 ||
+        target_operation->id != 0) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    psa_status_t status = psa_driver_wrapper_hash_clone(source_operation,
+                                                        target_operation);
+    if (status != PSA_SUCCESS) {
+        psa_hash_abort(target_operation);
+    }
+
+    return status;
+}
+
+
+/****************************************************************/
+/* MAC */
+/****************************************************************/
+
+psa_status_t psa_mac_abort(psa_mac_operation_t *operation)
+{
+    /* Aborting a non-active operation is allowed */
+    if (operation->id == 0) {
+        return PSA_SUCCESS;
+    }
+
+    psa_status_t status = psa_driver_wrapper_mac_abort(operation);
+    operation->mac_size = 0;
+    operation->is_sign = 0;
+    operation->id = 0;
+
+    return status;
+}
+
+static psa_status_t psa_mac_finalize_alg_and_key_validation(
+    psa_algorithm_t alg,
+    const psa_key_attributes_t *attributes,
+    uint8_t *mac_size)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_type_t key_type = psa_get_key_type(attributes);
+    size_t key_bits = psa_get_key_bits(attributes);
+
+    if (!PSA_ALG_IS_MAC(alg)) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    /* Validate the combination of key type and algorithm */
+    status = psa_mac_key_can_do(alg, key_type);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    /* Get the output length for the algorithm and key combination */
+    *mac_size = PSA_MAC_LENGTH(key_type, key_bits, alg);
+
+    if (*mac_size < 4) {
+        /* A very short MAC is too short for security since it can be
+         * brute-forced. Ancient protocols with 32-bit MACs do exist,
+         * so we make this our minimum, even though 32 bits is still
+         * too small for security. */
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    if (*mac_size > PSA_MAC_LENGTH(key_type, key_bits,
+                                   PSA_ALG_FULL_LENGTH_MAC(alg))) {
+        /* It's impossible to "truncate" to a larger length than the full length
+         * of the algorithm. */
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    if (*mac_size > PSA_MAC_MAX_SIZE) {
+        /* PSA_MAC_LENGTH returns the correct length even for a MAC algorithm
+         * that is disabled in the compile-time configuration. The result can
+         * therefore be larger than PSA_MAC_MAX_SIZE, which does take the
+         * configuration into account. In this case, force a return of
+         * PSA_ERROR_NOT_SUPPORTED here. Otherwise psa_mac_verify(), or
+         * psa_mac_compute(mac_size=PSA_MAC_MAX_SIZE), would return
+         * PSA_ERROR_BUFFER_TOO_SMALL for an unsupported algorithm whose MAC size
+         * is larger than PSA_MAC_MAX_SIZE, which is misleading and which breaks
+         * systematically generated tests. */
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    return PSA_SUCCESS;
+}
+
+static psa_status_t psa_mac_setup(psa_mac_operation_t *operation,
+                                  mbedtls_svc_key_id_t key,
+                                  psa_algorithm_t alg,
+                                  int is_sign)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot = NULL;
+
+    /* A context must be freshly initialized before it can be set up. */
+    if (operation->id != 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(
+        key,
+        &slot,
+        is_sign ? PSA_KEY_USAGE_SIGN_MESSAGE : PSA_KEY_USAGE_VERIFY_MESSAGE,
+        alg);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = psa_mac_finalize_alg_and_key_validation(alg, &slot->attr,
+                                                     &operation->mac_size);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    operation->is_sign = is_sign;
+    /* Dispatch the MAC setup call with validated input */
+    if (is_sign) {
+        status = psa_driver_wrapper_mac_sign_setup(operation,
+                                                   &slot->attr,
+                                                   slot->key.data,
+                                                   slot->key.bytes,
+                                                   alg);
+    } else {
+        status = psa_driver_wrapper_mac_verify_setup(operation,
+                                                     &slot->attr,
+                                                     slot->key.data,
+                                                     slot->key.bytes,
+                                                     alg);
+    }
+
+exit:
+    if (status != PSA_SUCCESS) {
+        psa_mac_abort(operation);
+    }
+
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+psa_status_t psa_mac_sign_setup(psa_mac_operation_t *operation,
+                                mbedtls_svc_key_id_t key,
+                                psa_algorithm_t alg)
+{
+    return psa_mac_setup(operation, key, alg, 1);
+}
+
+psa_status_t psa_mac_verify_setup(psa_mac_operation_t *operation,
+                                  mbedtls_svc_key_id_t key,
+                                  psa_algorithm_t alg)
+{
+    return psa_mac_setup(operation, key, alg, 0);
+}
+
+psa_status_t psa_mac_update(psa_mac_operation_t *operation,
+                            const uint8_t *input_external,
+                            size_t input_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_INPUT_DECLARE(input_external, input);
+
+    if (operation->id == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        return status;
+    }
+
+    /* Don't require hash implementations to behave correctly on a
+     * zero-length input, which may have an invalid pointer. */
+    if (input_length == 0) {
+        status = PSA_SUCCESS;
+        return status;
+    }
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    status = psa_driver_wrapper_mac_update(operation, input, input_length);
+
+    if (status != PSA_SUCCESS) {
+        psa_mac_abort(operation);
+    }
+
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+    LOCAL_INPUT_FREE(input_external, input);
+
+    return status;
+}
+
+psa_status_t psa_mac_sign_finish(psa_mac_operation_t *operation,
+                                 uint8_t *mac_external,
+                                 size_t mac_size,
+                                 size_t *mac_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t abort_status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_OUTPUT_DECLARE(mac_external, mac);
+    LOCAL_OUTPUT_ALLOC(mac_external, mac_size, mac);
+
+    if (operation->id == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (!operation->is_sign) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    /* Sanity check. This will guarantee that mac_size != 0 (and so mac != NULL)
+     * once all the error checks are done. */
+    if (operation->mac_size == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (mac_size < operation->mac_size) {
+        status = PSA_ERROR_BUFFER_TOO_SMALL;
+        goto exit;
+    }
+
+
+    status = psa_driver_wrapper_mac_sign_finish(operation,
+                                                mac, operation->mac_size,
+                                                mac_length);
+
+exit:
+    /* In case of success, set the potential excess room in the output buffer
+     * to an invalid value, to avoid potentially leaking a longer MAC.
+     * In case of error, set the output length and content to a safe default,
+     * such that in case the caller misses an error check, the output would be
+     * an unachievable MAC.
+     */
+    if (status != PSA_SUCCESS) {
+        *mac_length = mac_size;
+        operation->mac_size = 0;
+    }
+
+    if (mac != NULL) {
+        psa_wipe_tag_output_buffer(mac, status, mac_size, *mac_length);
+    }
+
+    abort_status = psa_mac_abort(operation);
+    LOCAL_OUTPUT_FREE(mac_external, mac);
+
+    return status == PSA_SUCCESS ? abort_status : status;
+}
+
+psa_status_t psa_mac_verify_finish(psa_mac_operation_t *operation,
+                                   const uint8_t *mac_external,
+                                   size_t mac_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t abort_status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_INPUT_DECLARE(mac_external, mac);
+
+    if (operation->id == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (operation->is_sign) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (operation->mac_size != mac_length) {
+        status = PSA_ERROR_INVALID_SIGNATURE;
+        goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(mac_external, mac_length, mac);
+    status = psa_driver_wrapper_mac_verify_finish(operation,
+                                                  mac, mac_length);
+
+exit:
+    abort_status = psa_mac_abort(operation);
+    LOCAL_INPUT_FREE(mac_external, mac);
+
+    return status == PSA_SUCCESS ? abort_status : status;
+}
+
+static psa_status_t psa_mac_compute_internal(mbedtls_svc_key_id_t key,
+                                             psa_algorithm_t alg,
+                                             const uint8_t *input,
+                                             size_t input_length,
+                                             uint8_t *mac,
+                                             size_t mac_size,
+                                             size_t *mac_length,
+                                             int is_sign)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+    uint8_t operation_mac_size = 0;
+
+    status = psa_get_and_lock_key_slot_with_policy(
+        key,
+        &slot,
+        is_sign ? PSA_KEY_USAGE_SIGN_MESSAGE : PSA_KEY_USAGE_VERIFY_MESSAGE,
+        alg);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = psa_mac_finalize_alg_and_key_validation(alg, &slot->attr,
+                                                     &operation_mac_size);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    if (mac_size < operation_mac_size) {
+        status = PSA_ERROR_BUFFER_TOO_SMALL;
+        goto exit;
+    }
+
+    status = psa_driver_wrapper_mac_compute(
+        &slot->attr,
+        slot->key.data, slot->key.bytes,
+        alg,
+        input, input_length,
+        mac, operation_mac_size, mac_length);
+
+exit:
+    /* In case of success, set the potential excess room in the output buffer
+     * to an invalid value, to avoid potentially leaking a longer MAC.
+     * In case of error, set the output length and content to a safe default,
+     * such that in case the caller misses an error check, the output would be
+     * an unachievable MAC.
+     */
+    if (status != PSA_SUCCESS) {
+        *mac_length = mac_size;
+        operation_mac_size = 0;
+    }
+
+    psa_wipe_tag_output_buffer(mac, status, mac_size, *mac_length);
+
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+psa_status_t psa_mac_compute(mbedtls_svc_key_id_t key,
+                             psa_algorithm_t alg,
+                             const uint8_t *input_external,
+                             size_t input_length,
+                             uint8_t *mac_external,
+                             size_t mac_size,
+                             size_t *mac_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_OUTPUT_DECLARE(mac_external, mac);
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    LOCAL_OUTPUT_ALLOC(mac_external, mac_size, mac);
+    status = psa_mac_compute_internal(key, alg,
+                                      input, input_length,
+                                      mac, mac_size, mac_length, 1);
+
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+    LOCAL_INPUT_FREE(input_external, input);
+    LOCAL_OUTPUT_FREE(mac_external, mac);
+
+    return status;
+}
+
+psa_status_t psa_mac_verify(mbedtls_svc_key_id_t key,
+                            psa_algorithm_t alg,
+                            const uint8_t *input_external,
+                            size_t input_length,
+                            const uint8_t *mac_external,
+                            size_t mac_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    uint8_t actual_mac[PSA_MAC_MAX_SIZE];
+    size_t actual_mac_length;
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_INPUT_DECLARE(mac_external, mac);
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    status = psa_mac_compute_internal(key, alg,
+                                      input, input_length,
+                                      actual_mac, sizeof(actual_mac),
+                                      &actual_mac_length, 0);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    if (mac_length != actual_mac_length) {
+        status = PSA_ERROR_INVALID_SIGNATURE;
+        goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(mac_external, mac_length, mac);
+    if (mbedtls_ct_memcmp(mac, actual_mac, actual_mac_length) != 0) {
+        status = PSA_ERROR_INVALID_SIGNATURE;
+        goto exit;
+    }
+
+exit:
+    mbedtls_platform_zeroize(actual_mac, sizeof(actual_mac));
+    LOCAL_INPUT_FREE(input_external, input);
+    LOCAL_INPUT_FREE(mac_external, mac);
+
+    return status;
+}
+
+/****************************************************************/
+/* Asymmetric cryptography */
+/****************************************************************/
+
+static psa_status_t psa_sign_verify_check_alg(int input_is_message,
+                                              psa_algorithm_t alg)
+{
+    if (input_is_message) {
+        if (!PSA_ALG_IS_SIGN_MESSAGE(alg)) {
+            return PSA_ERROR_INVALID_ARGUMENT;
+        }
+
+        if (PSA_ALG_IS_SIGN_HASH(alg)) {
+            if (!PSA_ALG_IS_HASH(PSA_ALG_SIGN_GET_HASH(alg))) {
+                return PSA_ERROR_INVALID_ARGUMENT;
+            }
+        }
+    } else {
+        if (!PSA_ALG_IS_SIGN_HASH(alg)) {
+            return PSA_ERROR_INVALID_ARGUMENT;
+        }
+    }
+
+    return PSA_SUCCESS;
+}
+
+static psa_status_t psa_sign_internal(mbedtls_svc_key_id_t key,
+                                      int input_is_message,
+                                      psa_algorithm_t alg,
+                                      const uint8_t *input,
+                                      size_t input_length,
+                                      uint8_t *signature,
+                                      size_t signature_size,
+                                      size_t *signature_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+
+    *signature_length = 0;
+
+    status = psa_sign_verify_check_alg(input_is_message, alg);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    /* Immediately reject a zero-length signature buffer. This guarantees
+     * that signature must be a valid pointer. (On the other hand, the input
+     * buffer can in principle be empty since it doesn't actually have
+     * to be a hash.) */
+    if (signature_size == 0) {
+        return PSA_ERROR_BUFFER_TOO_SMALL;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(
+        key, &slot,
+        input_is_message ? PSA_KEY_USAGE_SIGN_MESSAGE :
+        PSA_KEY_USAGE_SIGN_HASH,
+        alg);
+
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    if (!PSA_KEY_TYPE_IS_KEY_PAIR(slot->attr.type)) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    if (input_is_message) {
+        status = psa_driver_wrapper_sign_message(
+            &slot->attr, slot->key.data, slot->key.bytes,
+            alg, input, input_length,
+            signature, signature_size, signature_length);
+    } else {
+
+        status = psa_driver_wrapper_sign_hash(
+            &slot->attr, slot->key.data, slot->key.bytes,
+            alg, input, input_length,
+            signature, signature_size, signature_length);
+    }
+
+
+exit:
+    psa_wipe_tag_output_buffer(signature, status, signature_size,
+                               *signature_length);
+
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+static psa_status_t psa_verify_internal(mbedtls_svc_key_id_t key,
+                                        int input_is_message,
+                                        psa_algorithm_t alg,
+                                        const uint8_t *input,
+                                        size_t input_length,
+                                        const uint8_t *signature,
+                                        size_t signature_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+
+    status = psa_sign_verify_check_alg(input_is_message, alg);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(
+        key, &slot,
+        input_is_message ? PSA_KEY_USAGE_VERIFY_MESSAGE :
+        PSA_KEY_USAGE_VERIFY_HASH,
+        alg);
+
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    if (input_is_message) {
+        status = psa_driver_wrapper_verify_message(
+            &slot->attr, slot->key.data, slot->key.bytes,
+            alg, input, input_length,
+            signature, signature_length);
+    } else {
+        status = psa_driver_wrapper_verify_hash(
+            &slot->attr, slot->key.data, slot->key.bytes,
+            alg, input, input_length,
+            signature, signature_length);
+    }
+
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+
+}
+
+psa_status_t psa_sign_message_builtin(
+    const psa_key_attributes_t *attributes,
+    const uint8_t *key_buffer,
+    size_t key_buffer_size,
+    psa_algorithm_t alg,
+    const uint8_t *input,
+    size_t input_length,
+    uint8_t *signature,
+    size_t signature_size,
+    size_t *signature_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    if (PSA_ALG_IS_SIGN_HASH(alg)) {
+        size_t hash_length;
+        uint8_t hash[PSA_HASH_MAX_SIZE];
+
+        status = psa_driver_wrapper_hash_compute(
+            PSA_ALG_SIGN_GET_HASH(alg),
+            input, input_length,
+            hash, sizeof(hash), &hash_length);
+
+        if (status != PSA_SUCCESS) {
+            return status;
+        }
+
+        return psa_driver_wrapper_sign_hash(
+            attributes, key_buffer, key_buffer_size,
+            alg, hash, hash_length,
+            signature, signature_size, signature_length);
+    }
+
+    return PSA_ERROR_NOT_SUPPORTED;
+}
+
+psa_status_t psa_sign_message(mbedtls_svc_key_id_t key,
+                              psa_algorithm_t alg,
+                              const uint8_t *input_external,
+                              size_t input_length,
+                              uint8_t *signature_external,
+                              size_t signature_size,
+                              size_t *signature_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_OUTPUT_DECLARE(signature_external, signature);
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    LOCAL_OUTPUT_ALLOC(signature_external, signature_size, signature);
+    status = psa_sign_internal(key, 1, alg, input, input_length, signature,
+                               signature_size, signature_length);
+
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+    LOCAL_INPUT_FREE(input_external, input);
+    LOCAL_OUTPUT_FREE(signature_external, signature);
+    return status;
+}
+
+psa_status_t psa_verify_message_builtin(
+    const psa_key_attributes_t *attributes,
+    const uint8_t *key_buffer,
+    size_t key_buffer_size,
+    psa_algorithm_t alg,
+    const uint8_t *input,
+    size_t input_length,
+    const uint8_t *signature,
+    size_t signature_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    if (PSA_ALG_IS_SIGN_HASH(alg)) {
+        size_t hash_length;
+        uint8_t hash[PSA_HASH_MAX_SIZE];
+
+        status = psa_driver_wrapper_hash_compute(
+            PSA_ALG_SIGN_GET_HASH(alg),
+            input, input_length,
+            hash, sizeof(hash), &hash_length);
+
+        if (status != PSA_SUCCESS) {
+            return status;
+        }
+
+        return psa_driver_wrapper_verify_hash(
+            attributes, key_buffer, key_buffer_size,
+            alg, hash, hash_length,
+            signature, signature_length);
+    }
+
+    return PSA_ERROR_NOT_SUPPORTED;
+}
+
+psa_status_t psa_verify_message(mbedtls_svc_key_id_t key,
+                                psa_algorithm_t alg,
+                                const uint8_t *input_external,
+                                size_t input_length,
+                                const uint8_t *signature_external,
+                                size_t signature_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_INPUT_DECLARE(signature_external, signature);
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    LOCAL_INPUT_ALLOC(signature_external, signature_length, signature);
+    status = psa_verify_internal(key, 1, alg, input, input_length, signature,
+                                 signature_length);
+
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+    LOCAL_INPUT_FREE(input_external, input);
+    LOCAL_INPUT_FREE(signature_external, signature);
+
+    return status;
+}
+
+psa_status_t psa_sign_hash_builtin(
+    const psa_key_attributes_t *attributes,
+    const uint8_t *key_buffer, size_t key_buffer_size,
+    psa_algorithm_t alg, const uint8_t *hash, size_t hash_length,
+    uint8_t *signature, size_t signature_size, size_t *signature_length)
+{
+    if (attributes->type == PSA_KEY_TYPE_RSA_KEY_PAIR) {
+        if (PSA_ALG_IS_RSA_PKCS1V15_SIGN(alg) ||
+            PSA_ALG_IS_RSA_PSS(alg)) {
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || \
+            defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS)
+            return mbedtls_psa_rsa_sign_hash(
+                attributes,
+                key_buffer, key_buffer_size,
+                alg, hash, hash_length,
+                signature, signature_size, signature_length);
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) */
+        } else {
+            return PSA_ERROR_INVALID_ARGUMENT;
+        }
+    } else if (PSA_KEY_TYPE_IS_ECC(attributes->type)) {
+        if (PSA_ALG_IS_ECDSA(alg)) {
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
+            defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
+            return mbedtls_psa_ecdsa_sign_hash(
+                attributes,
+                key_buffer, key_buffer_size,
+                alg, hash, hash_length,
+                signature, signature_size, signature_length);
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
+        } else {
+            return PSA_ERROR_INVALID_ARGUMENT;
+        }
+    }
+
+    (void) key_buffer;
+    (void) key_buffer_size;
+    (void) hash;
+    (void) hash_length;
+    (void) signature;
+    (void) signature_size;
+    (void) signature_length;
+
+    return PSA_ERROR_NOT_SUPPORTED;
+}
+
+psa_status_t psa_sign_hash(mbedtls_svc_key_id_t key,
+                           psa_algorithm_t alg,
+                           const uint8_t *hash_external,
+                           size_t hash_length,
+                           uint8_t *signature_external,
+                           size_t signature_size,
+                           size_t *signature_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_INPUT_DECLARE(hash_external, hash);
+    LOCAL_OUTPUT_DECLARE(signature_external, signature);
+
+    LOCAL_INPUT_ALLOC(hash_external, hash_length, hash);
+    LOCAL_OUTPUT_ALLOC(signature_external, signature_size, signature);
+    status = psa_sign_internal(key, 0, alg, hash, hash_length, signature,
+                               signature_size, signature_length);
+
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+    LOCAL_INPUT_FREE(hash_external, hash);
+    LOCAL_OUTPUT_FREE(signature_external, signature);
+
+    return status;
+}
+
+psa_status_t psa_verify_hash_builtin(
+    const psa_key_attributes_t *attributes,
+    const uint8_t *key_buffer, size_t key_buffer_size,
+    psa_algorithm_t alg, const uint8_t *hash, size_t hash_length,
+    const uint8_t *signature, size_t signature_length)
+{
+    if (PSA_KEY_TYPE_IS_RSA(attributes->type)) {
+        if (PSA_ALG_IS_RSA_PKCS1V15_SIGN(alg) ||
+            PSA_ALG_IS_RSA_PSS(alg)) {
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || \
+            defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS)
+            return mbedtls_psa_rsa_verify_hash(
+                attributes,
+                key_buffer, key_buffer_size,
+                alg, hash, hash_length,
+                signature, signature_length);
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) */
+        } else {
+            return PSA_ERROR_INVALID_ARGUMENT;
+        }
+    } else if (PSA_KEY_TYPE_IS_ECC(attributes->type)) {
+        if (PSA_ALG_IS_ECDSA(alg)) {
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
+            defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
+            return mbedtls_psa_ecdsa_verify_hash(
+                attributes,
+                key_buffer, key_buffer_size,
+                alg, hash, hash_length,
+                signature, signature_length);
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
+        } else {
+            return PSA_ERROR_INVALID_ARGUMENT;
+        }
+    }
+
+    (void) key_buffer;
+    (void) key_buffer_size;
+    (void) hash;
+    (void) hash_length;
+    (void) signature;
+    (void) signature_length;
+
+    return PSA_ERROR_NOT_SUPPORTED;
+}
+
+psa_status_t psa_verify_hash(mbedtls_svc_key_id_t key,
+                             psa_algorithm_t alg,
+                             const uint8_t *hash_external,
+                             size_t hash_length,
+                             const uint8_t *signature_external,
+                             size_t signature_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_INPUT_DECLARE(hash_external, hash);
+    LOCAL_INPUT_DECLARE(signature_external, signature);
+
+    LOCAL_INPUT_ALLOC(hash_external, hash_length, hash);
+    LOCAL_INPUT_ALLOC(signature_external, signature_length, signature);
+    status = psa_verify_internal(key, 0, alg, hash, hash_length, signature,
+                                 signature_length);
+
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+    LOCAL_INPUT_FREE(hash_external, hash);
+    LOCAL_INPUT_FREE(signature_external, signature);
+
+    return status;
+}
+
+psa_status_t psa_asymmetric_encrypt(mbedtls_svc_key_id_t key,
+                                    psa_algorithm_t alg,
+                                    const uint8_t *input_external,
+                                    size_t input_length,
+                                    const uint8_t *salt_external,
+                                    size_t salt_length,
+                                    uint8_t *output_external,
+                                    size_t output_size,
+                                    size_t *output_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_INPUT_DECLARE(salt_external, salt);
+    LOCAL_OUTPUT_DECLARE(output_external, output);
+
+    (void) input;
+    (void) input_length;
+    (void) salt;
+    (void) output;
+    (void) output_size;
+
+    *output_length = 0;
+
+    if (!PSA_ALG_IS_RSA_OAEP(alg) && salt_length != 0) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(
+        key, &slot, PSA_KEY_USAGE_ENCRYPT, alg);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+    if (!(PSA_KEY_TYPE_IS_PUBLIC_KEY(slot->attr.type) ||
+          PSA_KEY_TYPE_IS_KEY_PAIR(slot->attr.type))) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    LOCAL_INPUT_ALLOC(salt_external, salt_length, salt);
+    LOCAL_OUTPUT_ALLOC(output_external, output_size, output);
+
+    status = psa_driver_wrapper_asymmetric_encrypt(
+        &slot->attr, slot->key.data, slot->key.bytes,
+        alg, input, input_length, salt, salt_length,
+        output, output_size, output_length);
+exit:
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    LOCAL_INPUT_FREE(input_external, input);
+    LOCAL_INPUT_FREE(salt_external, salt);
+    LOCAL_OUTPUT_FREE(output_external, output);
+
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+psa_status_t psa_asymmetric_decrypt(mbedtls_svc_key_id_t key,
+                                    psa_algorithm_t alg,
+                                    const uint8_t *input_external,
+                                    size_t input_length,
+                                    const uint8_t *salt_external,
+                                    size_t salt_length,
+                                    uint8_t *output_external,
+                                    size_t output_size,
+                                    size_t *output_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_INPUT_DECLARE(salt_external, salt);
+    LOCAL_OUTPUT_DECLARE(output_external, output);
+
+    (void) input;
+    (void) input_length;
+    (void) salt;
+    (void) output;
+    (void) output_size;
+
+    *output_length = 0;
+
+    if (!PSA_ALG_IS_RSA_OAEP(alg) && salt_length != 0) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(
+        key, &slot, PSA_KEY_USAGE_DECRYPT, alg);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+    if (!PSA_KEY_TYPE_IS_KEY_PAIR(slot->attr.type)) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    LOCAL_INPUT_ALLOC(salt_external, salt_length, salt);
+    LOCAL_OUTPUT_ALLOC(output_external, output_size, output);
+
+    status = psa_driver_wrapper_asymmetric_decrypt(
+        &slot->attr, slot->key.data, slot->key.bytes,
+        alg, input, input_length, salt, salt_length,
+        output, output_size, output_length);
+
+exit:
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    LOCAL_INPUT_FREE(input_external, input);
+    LOCAL_INPUT_FREE(salt_external, salt);
+    LOCAL_OUTPUT_FREE(output_external, output);
+
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+/****************************************************************/
+/* Asymmetric interruptible cryptography                        */
+/****************************************************************/
+
+static uint32_t psa_interruptible_max_ops = PSA_INTERRUPTIBLE_MAX_OPS_UNLIMITED;
+
+void psa_interruptible_set_max_ops(uint32_t max_ops)
+{
+    psa_interruptible_max_ops = max_ops;
+}
+
+uint32_t psa_interruptible_get_max_ops(void)
+{
+    return psa_interruptible_max_ops;
+}
+
+uint32_t psa_sign_hash_get_num_ops(
+    const psa_sign_hash_interruptible_operation_t *operation)
+{
+    return operation->num_ops;
+}
+
+uint32_t psa_verify_hash_get_num_ops(
+    const psa_verify_hash_interruptible_operation_t *operation)
+{
+    return operation->num_ops;
+}
+
+static psa_status_t psa_sign_hash_abort_internal(
+    psa_sign_hash_interruptible_operation_t *operation)
+{
+    if (operation->id == 0) {
+        /* The object has (apparently) been initialized but it is not (yet)
+         * in use. It's ok to call abort on such an object, and there's
+         * nothing to do. */
+        return PSA_SUCCESS;
+    }
+
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    status = psa_driver_wrapper_sign_hash_abort(operation);
+
+    operation->id = 0;
+
+    /* Do not clear either the error_occurred or num_ops elements here as they
+     * only want to be cleared by the application calling abort, not by abort
+     * being called at completion of an operation. */
+
+    return status;
+}
+
+psa_status_t psa_sign_hash_start(
+    psa_sign_hash_interruptible_operation_t *operation,
+    mbedtls_svc_key_id_t key, psa_algorithm_t alg,
+    const uint8_t *hash_external, size_t hash_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+
+    LOCAL_INPUT_DECLARE(hash_external, hash);
+
+    /* Check that start has not been previously called, or operation has not
+     * previously errored. */
+    if (operation->id != 0 || operation->error_occurred) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    status = psa_sign_verify_check_alg(0, alg);
+    if (status != PSA_SUCCESS) {
+        operation->error_occurred = 1;
+        return status;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(key, &slot,
+                                                   PSA_KEY_USAGE_SIGN_HASH,
+                                                   alg);
+
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    if (!PSA_KEY_TYPE_IS_KEY_PAIR(slot->attr.type)) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(hash_external, hash_length, hash);
+
+    /* Ensure ops count gets reset, in case of operation re-use. */
+    operation->num_ops = 0;
+
+    status = psa_driver_wrapper_sign_hash_start(operation, &slot->attr,
+                                                slot->key.data,
+                                                slot->key.bytes, alg,
+                                                hash, hash_length);
+exit:
+
+    if (status != PSA_SUCCESS) {
+        operation->error_occurred = 1;
+        psa_sign_hash_abort_internal(operation);
+    }
+
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    if (unlock_status != PSA_SUCCESS) {
+        operation->error_occurred = 1;
+    }
+
+    LOCAL_INPUT_FREE(hash_external, hash);
+
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+
+psa_status_t psa_sign_hash_complete(
+    psa_sign_hash_interruptible_operation_t *operation,
+    uint8_t *signature_external, size_t signature_size,
+    size_t *signature_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    LOCAL_OUTPUT_DECLARE(signature_external, signature);
+
+    *signature_length = 0;
+
+    /* Check that start has been called first, and that operation has not
+     * previously errored. */
+    if (operation->id == 0 || operation->error_occurred) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    /* Immediately reject a zero-length signature buffer. This guarantees that
+     * signature must be a valid pointer. */
+    if (signature_size == 0) {
+        status = PSA_ERROR_BUFFER_TOO_SMALL;
+        goto exit;
+    }
+
+    LOCAL_OUTPUT_ALLOC(signature_external, signature_size, signature);
+
+    status = psa_driver_wrapper_sign_hash_complete(operation, signature,
+                                                   signature_size,
+                                                   signature_length);
+
+    /* Update ops count with work done. */
+    operation->num_ops = psa_driver_wrapper_sign_hash_get_num_ops(operation);
+
+exit:
+
+    if (signature != NULL) {
+        psa_wipe_tag_output_buffer(signature, status, signature_size,
+                                   *signature_length);
+    }
+
+    if (status != PSA_OPERATION_INCOMPLETE) {
+        if (status != PSA_SUCCESS) {
+            operation->error_occurred = 1;
+        }
+
+        psa_sign_hash_abort_internal(operation);
+    }
+
+    LOCAL_OUTPUT_FREE(signature_external, signature);
+
+    return status;
+}
+
+psa_status_t psa_sign_hash_abort(
+    psa_sign_hash_interruptible_operation_t *operation)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    status = psa_sign_hash_abort_internal(operation);
+
+    /* We clear the number of ops done here, so that it is not cleared when
+     * the operation fails or succeeds, only on manual abort. */
+    operation->num_ops = 0;
+
+    /* Likewise, failure state. */
+    operation->error_occurred = 0;
+
+    return status;
+}
+
+static psa_status_t psa_verify_hash_abort_internal(
+    psa_verify_hash_interruptible_operation_t *operation)
+{
+    if (operation->id == 0) {
+        /* The object has (apparently) been initialized but it is not (yet)
+         * in use. It's ok to call abort on such an object, and there's
+         * nothing to do. */
+        return PSA_SUCCESS;
+    }
+
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    status = psa_driver_wrapper_verify_hash_abort(operation);
+
+    operation->id = 0;
+
+    /* Do not clear either the error_occurred or num_ops elements here as they
+     * only want to be cleared by the application calling abort, not by abort
+     * being called at completion of an operation. */
+
+    return status;
+}
+
+psa_status_t psa_verify_hash_start(
+    psa_verify_hash_interruptible_operation_t *operation,
+    mbedtls_svc_key_id_t key, psa_algorithm_t alg,
+    const uint8_t *hash_external, size_t hash_length,
+    const uint8_t *signature_external, size_t signature_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+
+    LOCAL_INPUT_DECLARE(hash_external, hash);
+    LOCAL_INPUT_DECLARE(signature_external, signature);
+
+    /* Check that start has not been previously called, or operation has not
+     * previously errored. */
+    if (operation->id != 0 || operation->error_occurred) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    status = psa_sign_verify_check_alg(0, alg);
+    if (status != PSA_SUCCESS) {
+        operation->error_occurred = 1;
+        return status;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(key, &slot,
+                                                   PSA_KEY_USAGE_VERIFY_HASH,
+                                                   alg);
+
+    if (status != PSA_SUCCESS) {
+        operation->error_occurred = 1;
+        return status;
+    }
+
+    LOCAL_INPUT_ALLOC(hash_external, hash_length, hash);
+    LOCAL_INPUT_ALLOC(signature_external, signature_length, signature);
+
+    /* Ensure ops count gets reset, in case of operation re-use. */
+    operation->num_ops = 0;
+
+    status = psa_driver_wrapper_verify_hash_start(operation, &slot->attr,
+                                                  slot->key.data,
+                                                  slot->key.bytes,
+                                                  alg, hash, hash_length,
+                                                  signature, signature_length);
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+
+    if (status != PSA_SUCCESS) {
+        operation->error_occurred = 1;
+        psa_verify_hash_abort_internal(operation);
+    }
+
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    if (unlock_status != PSA_SUCCESS) {
+        operation->error_occurred = 1;
+    }
+
+    LOCAL_INPUT_FREE(hash_external, hash);
+    LOCAL_INPUT_FREE(signature_external, signature);
+
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+psa_status_t psa_verify_hash_complete(
+    psa_verify_hash_interruptible_operation_t *operation)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    /* Check that start has been called first, and that operation has not
+     * previously errored. */
+    if (operation->id == 0 || operation->error_occurred) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    status = psa_driver_wrapper_verify_hash_complete(operation);
+
+    /* Update ops count with work done. */
+    operation->num_ops = psa_driver_wrapper_verify_hash_get_num_ops(
+        operation);
+
+exit:
+
+    if (status != PSA_OPERATION_INCOMPLETE) {
+        if (status != PSA_SUCCESS) {
+            operation->error_occurred = 1;
+        }
+
+        psa_verify_hash_abort_internal(operation);
+    }
+
+    return status;
+}
+
+psa_status_t psa_verify_hash_abort(
+    psa_verify_hash_interruptible_operation_t *operation)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    status = psa_verify_hash_abort_internal(operation);
+
+    /* We clear the number of ops done here, so that it is not cleared when
+     * the operation fails or succeeds, only on manual abort. */
+    operation->num_ops = 0;
+
+    /* Likewise, failure state. */
+    operation->error_occurred = 0;
+
+    return status;
+}
+
+/****************************************************************/
+/* Asymmetric interruptible cryptography internal               */
+/* implementations                                              */
+/****************************************************************/
+
+void mbedtls_psa_interruptible_set_max_ops(uint32_t max_ops)
+{
+
+#if (defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)) && \
+    defined(MBEDTLS_ECP_RESTARTABLE)
+
+    /* Internal implementation uses zero to indicate infinite number max ops,
+     * therefore avoid this value, and set to minimum possible. */
+    if (max_ops == 0) {
+        max_ops = 1;
+    }
+
+    mbedtls_ecp_set_max_ops(max_ops);
+#else
+    (void) max_ops;
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) &&
+        * defined( MBEDTLS_ECP_RESTARTABLE ) */
+}
+
+uint32_t mbedtls_psa_sign_hash_get_num_ops(
+    const mbedtls_psa_sign_hash_interruptible_operation_t *operation)
+{
+#if (defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)) && \
+    defined(MBEDTLS_ECP_RESTARTABLE)
+
+    return operation->num_ops;
+#else
+    (void) operation;
+    return 0;
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) &&
+        * defined( MBEDTLS_ECP_RESTARTABLE ) */
+}
+
+uint32_t mbedtls_psa_verify_hash_get_num_ops(
+    const mbedtls_psa_verify_hash_interruptible_operation_t *operation)
+{
+    #if (defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)) && \
+    defined(MBEDTLS_ECP_RESTARTABLE)
+
+    return operation->num_ops;
+#else
+    (void) operation;
+    return 0;
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) &&
+        * defined( MBEDTLS_ECP_RESTARTABLE ) */
+}
+
+psa_status_t mbedtls_psa_sign_hash_start(
+    mbedtls_psa_sign_hash_interruptible_operation_t *operation,
+    const psa_key_attributes_t *attributes, const uint8_t *key_buffer,
+    size_t key_buffer_size, psa_algorithm_t alg,
+    const uint8_t *hash, size_t hash_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    size_t required_hash_length;
+
+    if (!PSA_KEY_TYPE_IS_ECC(attributes->type)) {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    if (!PSA_ALG_IS_ECDSA(alg)) {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+#if (defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)) && \
+    defined(MBEDTLS_ECP_RESTARTABLE)
+
+    mbedtls_ecdsa_restart_init(&operation->restart_ctx);
+
+    /* Ensure num_ops is zero'ed in case of context re-use. */
+    operation->num_ops = 0;
+
+    status = mbedtls_psa_ecp_load_representation(attributes->type,
+                                                 attributes->bits,
+                                                 key_buffer,
+                                                 key_buffer_size,
+                                                 &operation->ctx);
+
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    operation->coordinate_bytes = PSA_BITS_TO_BYTES(
+        operation->ctx->grp.nbits);
+
+    psa_algorithm_t hash_alg = PSA_ALG_SIGN_GET_HASH(alg);
+    operation->md_alg = mbedtls_md_type_from_psa_alg(hash_alg);
+    operation->alg = alg;
+
+    /* We only need to store the same length of hash as the private key size
+     * here, it would be truncated by the internal implementation anyway. */
+    required_hash_length = (hash_length < operation->coordinate_bytes ?
+                            hash_length : operation->coordinate_bytes);
+
+    if (required_hash_length > sizeof(operation->hash)) {
+        /* Shouldn't happen, but better safe than sorry. */
+        return PSA_ERROR_CORRUPTION_DETECTED;
+    }
+
+    memcpy(operation->hash, hash, required_hash_length);
+    operation->hash_length = required_hash_length;
+
+    return PSA_SUCCESS;
+
+#else
+    (void) operation;
+    (void) key_buffer;
+    (void) key_buffer_size;
+    (void) alg;
+    (void) hash;
+    (void) hash_length;
+    (void) status;
+    (void) required_hash_length;
+
+    return PSA_ERROR_NOT_SUPPORTED;
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) &&
+        * defined( MBEDTLS_ECP_RESTARTABLE ) */
+}
+
+psa_status_t mbedtls_psa_sign_hash_complete(
+    mbedtls_psa_sign_hash_interruptible_operation_t *operation,
+    uint8_t *signature, size_t signature_size,
+    size_t *signature_length)
+{
+#if (defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)) && \
+    defined(MBEDTLS_ECP_RESTARTABLE)
+
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    mbedtls_mpi r;
+    mbedtls_mpi s;
+
+    mbedtls_mpi_init(&r);
+    mbedtls_mpi_init(&s);
+
+    /* Ensure max_ops is set to the current value (or default). */
+    mbedtls_psa_interruptible_set_max_ops(psa_interruptible_get_max_ops());
+
+    if (signature_size < 2 * operation->coordinate_bytes) {
+        status = PSA_ERROR_BUFFER_TOO_SMALL;
+        goto exit;
+    }
+
+    if (PSA_ALG_ECDSA_IS_DETERMINISTIC(operation->alg)) {
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
+        status = mbedtls_to_psa_error(
+            mbedtls_ecdsa_sign_det_restartable(&operation->ctx->grp,
+                                               &r,
+                                               &s,
+                                               &operation->ctx->d,
+                                               operation->hash,
+                                               operation->hash_length,
+                                               operation->md_alg,
+                                               mbedtls_psa_get_random,
+                                               MBEDTLS_PSA_RANDOM_STATE,
+                                               &operation->restart_ctx));
+#else /* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
+        status = PSA_ERROR_NOT_SUPPORTED;
+        goto exit;
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
+    } else {
+        status = mbedtls_to_psa_error(
+            mbedtls_ecdsa_sign_restartable(&operation->ctx->grp,
+                                           &r,
+                                           &s,
+                                           &operation->ctx->d,
+                                           operation->hash,
+                                           operation->hash_length,
+                                           mbedtls_psa_get_random,
+                                           MBEDTLS_PSA_RANDOM_STATE,
+                                           mbedtls_psa_get_random,
+                                           MBEDTLS_PSA_RANDOM_STATE,
+                                           &operation->restart_ctx));
+    }
+
+    /* Hide the fact that the restart context only holds a delta of number of
+     * ops done during the last operation, not an absolute value. */
+    operation->num_ops += operation->restart_ctx.ecp.ops_done;
+
+    if (status == PSA_SUCCESS) {
+        status =  mbedtls_to_psa_error(
+            mbedtls_mpi_write_binary(&r,
+                                     signature,
+                                     operation->coordinate_bytes)
+            );
+
+        if (status != PSA_SUCCESS) {
+            goto exit;
+        }
+
+        status =  mbedtls_to_psa_error(
+            mbedtls_mpi_write_binary(&s,
+                                     signature +
+                                     operation->coordinate_bytes,
+                                     operation->coordinate_bytes)
+            );
+
+        if (status != PSA_SUCCESS) {
+            goto exit;
+        }
+
+        *signature_length = operation->coordinate_bytes * 2;
+
+        status = PSA_SUCCESS;
+    }
+
+exit:
+
+    mbedtls_mpi_free(&r);
+    mbedtls_mpi_free(&s);
+    return status;
+
+ #else
+
+    (void) operation;
+    (void) signature;
+    (void) signature_size;
+    (void) signature_length;
+
+    return PSA_ERROR_NOT_SUPPORTED;
+
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) &&
+        * defined( MBEDTLS_ECP_RESTARTABLE ) */
+}
+
+psa_status_t mbedtls_psa_sign_hash_abort(
+    mbedtls_psa_sign_hash_interruptible_operation_t *operation)
+{
+
+#if (defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)) && \
+    defined(MBEDTLS_ECP_RESTARTABLE)
+
+    if (operation->ctx) {
+        mbedtls_ecdsa_free(operation->ctx);
+        mbedtls_free(operation->ctx);
+        operation->ctx = NULL;
+    }
+
+    mbedtls_ecdsa_restart_free(&operation->restart_ctx);
+
+    operation->num_ops = 0;
+
+    return PSA_SUCCESS;
+
+#else
+
+    (void) operation;
+
+    return PSA_ERROR_NOT_SUPPORTED;
+
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) &&
+        * defined( MBEDTLS_ECP_RESTARTABLE ) */
+}
+
+psa_status_t mbedtls_psa_verify_hash_start(
+    mbedtls_psa_verify_hash_interruptible_operation_t *operation,
+    const psa_key_attributes_t *attributes,
+    const uint8_t *key_buffer, size_t key_buffer_size,
+    psa_algorithm_t alg,
+    const uint8_t *hash, size_t hash_length,
+    const uint8_t *signature, size_t signature_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    size_t coordinate_bytes = 0;
+    size_t required_hash_length = 0;
+
+    if (!PSA_KEY_TYPE_IS_ECC(attributes->type)) {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    if (!PSA_ALG_IS_ECDSA(alg)) {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+#if (defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)) && \
+    defined(MBEDTLS_ECP_RESTARTABLE)
+
+    mbedtls_ecdsa_restart_init(&operation->restart_ctx);
+    mbedtls_mpi_init(&operation->r);
+    mbedtls_mpi_init(&operation->s);
+
+    /* Ensure num_ops is zero'ed in case of context re-use. */
+    operation->num_ops = 0;
+
+    status = mbedtls_psa_ecp_load_representation(attributes->type,
+                                                 attributes->bits,
+                                                 key_buffer,
+                                                 key_buffer_size,
+                                                 &operation->ctx);
+
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    coordinate_bytes = PSA_BITS_TO_BYTES(operation->ctx->grp.nbits);
+
+    if (signature_length != 2 * coordinate_bytes) {
+        return PSA_ERROR_INVALID_SIGNATURE;
+    }
+
+    status = mbedtls_to_psa_error(
+        mbedtls_mpi_read_binary(&operation->r,
+                                signature,
+                                coordinate_bytes));
+
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    status = mbedtls_to_psa_error(
+        mbedtls_mpi_read_binary(&operation->s,
+                                signature +
+                                coordinate_bytes,
+                                coordinate_bytes));
+
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    status = mbedtls_psa_ecp_load_public_part(operation->ctx);
+
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    /* We only need to store the same length of hash as the private key size
+     * here, it would be truncated by the internal implementation anyway. */
+    required_hash_length = (hash_length < coordinate_bytes ? hash_length :
+                            coordinate_bytes);
+
+    if (required_hash_length > sizeof(operation->hash)) {
+        /* Shouldn't happen, but better safe than sorry. */
+        return PSA_ERROR_CORRUPTION_DETECTED;
+    }
+
+    memcpy(operation->hash, hash, required_hash_length);
+    operation->hash_length = required_hash_length;
+
+    return PSA_SUCCESS;
+#else
+    (void) operation;
+    (void) key_buffer;
+    (void) key_buffer_size;
+    (void) alg;
+    (void) hash;
+    (void) hash_length;
+    (void) signature;
+    (void) signature_length;
+    (void) status;
+    (void) coordinate_bytes;
+    (void) required_hash_length;
+
+    return PSA_ERROR_NOT_SUPPORTED;
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) &&
+        * defined( MBEDTLS_ECP_RESTARTABLE ) */
+}
+
+psa_status_t mbedtls_psa_verify_hash_complete(
+    mbedtls_psa_verify_hash_interruptible_operation_t *operation)
+{
+
+#if (defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)) && \
+    defined(MBEDTLS_ECP_RESTARTABLE)
+
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    /* Ensure max_ops is set to the current value (or default). */
+    mbedtls_psa_interruptible_set_max_ops(psa_interruptible_get_max_ops());
+
+    status = mbedtls_to_psa_error(
+        mbedtls_ecdsa_verify_restartable(&operation->ctx->grp,
+                                         operation->hash,
+                                         operation->hash_length,
+                                         &operation->ctx->Q,
+                                         &operation->r,
+                                         &operation->s,
+                                         &operation->restart_ctx));
+
+    /* Hide the fact that the restart context only holds a delta of number of
+     * ops done during the last operation, not an absolute value. */
+    operation->num_ops += operation->restart_ctx.ecp.ops_done;
+
+    return status;
+#else
+    (void) operation;
+
+    return PSA_ERROR_NOT_SUPPORTED;
+
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) &&
+        * defined( MBEDTLS_ECP_RESTARTABLE ) */
+}
+
+psa_status_t mbedtls_psa_verify_hash_abort(
+    mbedtls_psa_verify_hash_interruptible_operation_t *operation)
+{
+
+#if (defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)) && \
+    defined(MBEDTLS_ECP_RESTARTABLE)
+
+    if (operation->ctx) {
+        mbedtls_ecdsa_free(operation->ctx);
+        mbedtls_free(operation->ctx);
+        operation->ctx = NULL;
+    }
+
+    mbedtls_ecdsa_restart_free(&operation->restart_ctx);
+
+    operation->num_ops = 0;
+
+    mbedtls_mpi_free(&operation->r);
+    mbedtls_mpi_free(&operation->s);
+
+    return PSA_SUCCESS;
+
+#else
+    (void) operation;
+
+    return PSA_ERROR_NOT_SUPPORTED;
+
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) &&
+        * defined( MBEDTLS_ECP_RESTARTABLE ) */
+}
+
+static psa_status_t psa_generate_random_internal(uint8_t *output,
+                                                 size_t output_size)
+{
+    GUARD_MODULE_INITIALIZED;
+
+#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
+
+    psa_status_t status;
+    size_t output_length = 0;
+    status = mbedtls_psa_external_get_random(&global_data.rng,
+                                             output, output_size,
+                                             &output_length);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+    /* Breaking up a request into smaller chunks is currently not supported
+     * for the external RNG interface. */
+    if (output_length != output_size) {
+        return PSA_ERROR_INSUFFICIENT_ENTROPY;
+    }
+    return PSA_SUCCESS;
+
+#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
+
+    while (output_size > 0) {
+        int ret = MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED;
+        size_t request_size =
+            (output_size > MBEDTLS_PSA_RANDOM_MAX_REQUEST ?
+             MBEDTLS_PSA_RANDOM_MAX_REQUEST :
+             output_size);
+#if defined(MBEDTLS_CTR_DRBG_C)
+        ret = mbedtls_ctr_drbg_random(&global_data.rng.drbg, output, request_size);
+#elif defined(MBEDTLS_HMAC_DRBG_C)
+        ret = mbedtls_hmac_drbg_random(&global_data.rng.drbg, output, request_size);
+#endif /* !MBEDTLS_CTR_DRBG_C && !MBEDTLS_HMAC_DRBG_C */
+        if (ret != 0) {
+            return mbedtls_to_psa_error(ret);
+        }
+        output_size -= request_size;
+        output += request_size;
+    }
+    return PSA_SUCCESS;
+#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
+}
+
+
+/****************************************************************/
+/* Symmetric cryptography */
+/****************************************************************/
+
+static psa_status_t psa_cipher_setup(psa_cipher_operation_t *operation,
+                                     mbedtls_svc_key_id_t key,
+                                     psa_algorithm_t alg,
+                                     mbedtls_operation_t cipher_operation)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot = NULL;
+    psa_key_usage_t usage = (cipher_operation == MBEDTLS_ENCRYPT ?
+                             PSA_KEY_USAGE_ENCRYPT :
+                             PSA_KEY_USAGE_DECRYPT);
+
+    /* A context must be freshly initialized before it can be set up. */
+    if (operation->id != 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (!PSA_ALG_IS_CIPHER(alg)) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(key, &slot, usage, alg);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    /* Initialize the operation struct members, except for id. The id member
+     * is used to indicate to psa_cipher_abort that there are resources to free,
+     * so we only set it (in the driver wrapper) after resources have been
+     * allocated/initialized. */
+    operation->iv_set = 0;
+    if (alg == PSA_ALG_ECB_NO_PADDING) {
+        operation->iv_required = 0;
+    } else {
+        operation->iv_required = 1;
+    }
+    operation->default_iv_length = PSA_CIPHER_IV_LENGTH(slot->attr.type, alg);
+
+    /* Try doing the operation through a driver before using software fallback. */
+    if (cipher_operation == MBEDTLS_ENCRYPT) {
+        status = psa_driver_wrapper_cipher_encrypt_setup(operation,
+                                                         &slot->attr,
+                                                         slot->key.data,
+                                                         slot->key.bytes,
+                                                         alg);
+    } else {
+        status = psa_driver_wrapper_cipher_decrypt_setup(operation,
+                                                         &slot->attr,
+                                                         slot->key.data,
+                                                         slot->key.bytes,
+                                                         alg);
+    }
+
+exit:
+    if (status != PSA_SUCCESS) {
+        psa_cipher_abort(operation);
+    }
+
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+psa_status_t psa_cipher_encrypt_setup(psa_cipher_operation_t *operation,
+                                      mbedtls_svc_key_id_t key,
+                                      psa_algorithm_t alg)
+{
+    return psa_cipher_setup(operation, key, alg, MBEDTLS_ENCRYPT);
+}
+
+psa_status_t psa_cipher_decrypt_setup(psa_cipher_operation_t *operation,
+                                      mbedtls_svc_key_id_t key,
+                                      psa_algorithm_t alg)
+{
+    return psa_cipher_setup(operation, key, alg, MBEDTLS_DECRYPT);
+}
+
+psa_status_t psa_cipher_generate_iv(psa_cipher_operation_t *operation,
+                                    uint8_t *iv_external,
+                                    size_t iv_size,
+                                    size_t *iv_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    size_t default_iv_length = 0;
+
+    LOCAL_OUTPUT_DECLARE(iv_external, iv);
+
+    if (operation->id == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (operation->iv_set || !operation->iv_required) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    default_iv_length = operation->default_iv_length;
+    if (iv_size < default_iv_length) {
+        status = PSA_ERROR_BUFFER_TOO_SMALL;
+        goto exit;
+    }
+
+    if (default_iv_length > PSA_CIPHER_IV_MAX_SIZE) {
+        status = PSA_ERROR_GENERIC_ERROR;
+        goto exit;
+    }
+
+    LOCAL_OUTPUT_ALLOC(iv_external, default_iv_length, iv);
+
+    status = psa_generate_random_internal(iv, default_iv_length);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = psa_driver_wrapper_cipher_set_iv(operation,
+                                              iv, default_iv_length);
+
+exit:
+    if (status == PSA_SUCCESS) {
+        *iv_length = default_iv_length;
+        operation->iv_set = 1;
+    } else {
+        *iv_length = 0;
+        psa_cipher_abort(operation);
+        if (iv != NULL) {
+            mbedtls_platform_zeroize(iv, default_iv_length);
+        }
+    }
+
+    LOCAL_OUTPUT_FREE(iv_external, iv);
+    return status;
+}
+
+psa_status_t psa_cipher_set_iv(psa_cipher_operation_t *operation,
+                               const uint8_t *iv_external,
+                               size_t iv_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    LOCAL_INPUT_DECLARE(iv_external, iv);
+
+    if (operation->id == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (operation->iv_set || !operation->iv_required) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (iv_length > PSA_CIPHER_IV_MAX_SIZE) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(iv_external, iv_length, iv);
+
+    status = psa_driver_wrapper_cipher_set_iv(operation,
+                                              iv,
+                                              iv_length);
+
+exit:
+    if (status == PSA_SUCCESS) {
+        operation->iv_set = 1;
+    } else {
+        psa_cipher_abort(operation);
+    }
+
+    LOCAL_INPUT_FREE(iv_external, iv);
+
+    return status;
+}
+
+psa_status_t psa_cipher_update(psa_cipher_operation_t *operation,
+                               const uint8_t *input_external,
+                               size_t input_length,
+                               uint8_t *output_external,
+                               size_t output_size,
+                               size_t *output_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_OUTPUT_DECLARE(output_external, output);
+
+    if (operation->id == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (operation->iv_required && !operation->iv_set) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    LOCAL_OUTPUT_ALLOC(output_external, output_size, output);
+
+    status = psa_driver_wrapper_cipher_update(operation,
+                                              input,
+                                              input_length,
+                                              output,
+                                              output_size,
+                                              output_length);
+
+exit:
+    if (status != PSA_SUCCESS) {
+        psa_cipher_abort(operation);
+    }
+
+    LOCAL_INPUT_FREE(input_external, input);
+    LOCAL_OUTPUT_FREE(output_external, output);
+
+    return status;
+}
+
+psa_status_t psa_cipher_finish(psa_cipher_operation_t *operation,
+                               uint8_t *output_external,
+                               size_t output_size,
+                               size_t *output_length)
+{
+    psa_status_t status = PSA_ERROR_GENERIC_ERROR;
+
+    LOCAL_OUTPUT_DECLARE(output_external, output);
+
+    if (operation->id == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (operation->iv_required && !operation->iv_set) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    LOCAL_OUTPUT_ALLOC(output_external, output_size, output);
+
+    status = psa_driver_wrapper_cipher_finish(operation,
+                                              output,
+                                              output_size,
+                                              output_length);
+
+exit:
+    if (status == PSA_SUCCESS) {
+        status = psa_cipher_abort(operation);
+    } else {
+        *output_length = 0;
+        (void) psa_cipher_abort(operation);
+    }
+
+    LOCAL_OUTPUT_FREE(output_external, output);
+
+    return status;
+}
+
+psa_status_t psa_cipher_abort(psa_cipher_operation_t *operation)
+{
+    if (operation->id == 0) {
+        /* The object has (apparently) been initialized but it is not (yet)
+         * in use. It's ok to call abort on such an object, and there's
+         * nothing to do. */
+        return PSA_SUCCESS;
+    }
+
+    psa_driver_wrapper_cipher_abort(operation);
+
+    operation->id = 0;
+    operation->iv_set = 0;
+    operation->iv_required = 0;
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_cipher_encrypt(mbedtls_svc_key_id_t key,
+                                psa_algorithm_t alg,
+                                const uint8_t *input_external,
+                                size_t input_length,
+                                uint8_t *output_external,
+                                size_t output_size,
+                                size_t *output_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot = NULL;
+    uint8_t local_iv[PSA_CIPHER_IV_MAX_SIZE];
+    size_t default_iv_length = 0;
+
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_OUTPUT_DECLARE(output_external, output);
+
+    if (!PSA_ALG_IS_CIPHER(alg)) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(key, &slot,
+                                                   PSA_KEY_USAGE_ENCRYPT,
+                                                   alg);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    default_iv_length = PSA_CIPHER_IV_LENGTH(slot->attr.type, alg);
+    if (default_iv_length > PSA_CIPHER_IV_MAX_SIZE) {
+        status = PSA_ERROR_GENERIC_ERROR;
+        goto exit;
+    }
+
+    if (default_iv_length > 0) {
+        if (output_size < default_iv_length) {
+            status = PSA_ERROR_BUFFER_TOO_SMALL;
+            goto exit;
+        }
+
+        status = psa_generate_random_internal(local_iv, default_iv_length);
+        if (status != PSA_SUCCESS) {
+            goto exit;
+        }
+    }
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    LOCAL_OUTPUT_ALLOC(output_external, output_size, output);
+
+    status = psa_driver_wrapper_cipher_encrypt(
+        &slot->attr, slot->key.data, slot->key.bytes,
+        alg, local_iv, default_iv_length, input, input_length,
+        psa_crypto_buffer_offset(output, default_iv_length),
+        output_size - default_iv_length, output_length);
+
+exit:
+    unlock_status = psa_unregister_read_under_mutex(slot);
+    if (status == PSA_SUCCESS) {
+        status = unlock_status;
+    }
+
+    if (status == PSA_SUCCESS) {
+        if (default_iv_length > 0) {
+            memcpy(output, local_iv, default_iv_length);
+        }
+        *output_length += default_iv_length;
+    } else {
+        *output_length = 0;
+    }
+
+    LOCAL_INPUT_FREE(input_external, input);
+    LOCAL_OUTPUT_FREE(output_external, output);
+
+    return status;
+}
+
+psa_status_t psa_cipher_decrypt(mbedtls_svc_key_id_t key,
+                                psa_algorithm_t alg,
+                                const uint8_t *input_external,
+                                size_t input_length,
+                                uint8_t *output_external,
+                                size_t output_size,
+                                size_t *output_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot = NULL;
+
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_OUTPUT_DECLARE(output_external, output);
+
+    if (!PSA_ALG_IS_CIPHER(alg)) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(key, &slot,
+                                                   PSA_KEY_USAGE_DECRYPT,
+                                                   alg);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    if (input_length < PSA_CIPHER_IV_LENGTH(slot->attr.type, alg)) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    LOCAL_OUTPUT_ALLOC(output_external, output_size, output);
+
+    status = psa_driver_wrapper_cipher_decrypt(
+        &slot->attr, slot->key.data, slot->key.bytes,
+        alg, input, input_length,
+        output, output_size, output_length);
+
+exit:
+    unlock_status = psa_unregister_read_under_mutex(slot);
+    if (status == PSA_SUCCESS) {
+        status = unlock_status;
+    }
+
+    if (status != PSA_SUCCESS) {
+        *output_length = 0;
+    }
+
+    LOCAL_INPUT_FREE(input_external, input);
+    LOCAL_OUTPUT_FREE(output_external, output);
+
+    return status;
+}
+
+
+/****************************************************************/
+/* AEAD */
+/****************************************************************/
+
+/* Helper function to get the base algorithm from its variants. */
+static psa_algorithm_t psa_aead_get_base_algorithm(psa_algorithm_t alg)
+{
+    return PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG(alg);
+}
+
+/* Helper function to perform common nonce length checks. */
+static psa_status_t psa_aead_check_nonce_length(psa_algorithm_t alg,
+                                                size_t nonce_length)
+{
+    psa_algorithm_t base_alg = psa_aead_get_base_algorithm(alg);
+
+    switch (base_alg) {
+#if defined(PSA_WANT_ALG_GCM)
+        case PSA_ALG_GCM:
+            /* Not checking max nonce size here as GCM spec allows almost
+             * arbitrarily large nonces. Please note that we do not generally
+             * recommend the usage of nonces of greater length than
+             * PSA_AEAD_NONCE_MAX_SIZE, as large nonces are hashed to a shorter
+             * size, which can then lead to collisions if you encrypt a very
+             * large number of messages.*/
+            if (nonce_length != 0) {
+                return PSA_SUCCESS;
+            }
+            break;
+#endif /* PSA_WANT_ALG_GCM */
+#if defined(PSA_WANT_ALG_CCM)
+        case PSA_ALG_CCM:
+            if (nonce_length >= 7 && nonce_length <= 13) {
+                return PSA_SUCCESS;
+            }
+            break;
+#endif /* PSA_WANT_ALG_CCM */
+#if defined(PSA_WANT_ALG_CHACHA20_POLY1305)
+        case PSA_ALG_CHACHA20_POLY1305:
+            if (nonce_length == 12) {
+                return PSA_SUCCESS;
+            } else if (nonce_length == 8) {
+                return PSA_ERROR_NOT_SUPPORTED;
+            }
+            break;
+#endif /* PSA_WANT_ALG_CHACHA20_POLY1305 */
+        default:
+            (void) nonce_length;
+            return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    return PSA_ERROR_INVALID_ARGUMENT;
+}
+
+static psa_status_t psa_aead_check_algorithm(psa_algorithm_t alg)
+{
+    if (!PSA_ALG_IS_AEAD(alg) || PSA_ALG_IS_WILDCARD(alg)) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_aead_encrypt(mbedtls_svc_key_id_t key,
+                              psa_algorithm_t alg,
+                              const uint8_t *nonce_external,
+                              size_t nonce_length,
+                              const uint8_t *additional_data_external,
+                              size_t additional_data_length,
+                              const uint8_t *plaintext_external,
+                              size_t plaintext_length,
+                              uint8_t *ciphertext_external,
+                              size_t ciphertext_size,
+                              size_t *ciphertext_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+
+    LOCAL_INPUT_DECLARE(nonce_external, nonce);
+    LOCAL_INPUT_DECLARE(additional_data_external, additional_data);
+    LOCAL_INPUT_DECLARE(plaintext_external, plaintext);
+    LOCAL_OUTPUT_DECLARE(ciphertext_external, ciphertext);
+
+    *ciphertext_length = 0;
+
+    status = psa_aead_check_algorithm(alg);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(
+        key, &slot, PSA_KEY_USAGE_ENCRYPT, alg);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    LOCAL_INPUT_ALLOC(nonce_external, nonce_length, nonce);
+    LOCAL_INPUT_ALLOC(additional_data_external, additional_data_length, additional_data);
+    LOCAL_INPUT_ALLOC(plaintext_external, plaintext_length, plaintext);
+    LOCAL_OUTPUT_ALLOC(ciphertext_external, ciphertext_size, ciphertext);
+
+    status = psa_aead_check_nonce_length(alg, nonce_length);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = psa_driver_wrapper_aead_encrypt(
+        &slot->attr, slot->key.data, slot->key.bytes,
+        alg,
+        nonce, nonce_length,
+        additional_data, additional_data_length,
+        plaintext, plaintext_length,
+        ciphertext, ciphertext_size, ciphertext_length);
+
+    if (status != PSA_SUCCESS && ciphertext_size != 0) {
+        memset(ciphertext, 0, ciphertext_size);
+    }
+
+exit:
+    LOCAL_INPUT_FREE(nonce_external, nonce);
+    LOCAL_INPUT_FREE(additional_data_external, additional_data);
+    LOCAL_INPUT_FREE(plaintext_external, plaintext);
+    LOCAL_OUTPUT_FREE(ciphertext_external, ciphertext);
+
+    psa_unregister_read_under_mutex(slot);
+
+    return status;
+}
+
+psa_status_t psa_aead_decrypt(mbedtls_svc_key_id_t key,
+                              psa_algorithm_t alg,
+                              const uint8_t *nonce_external,
+                              size_t nonce_length,
+                              const uint8_t *additional_data_external,
+                              size_t additional_data_length,
+                              const uint8_t *ciphertext_external,
+                              size_t ciphertext_length,
+                              uint8_t *plaintext_external,
+                              size_t plaintext_size,
+                              size_t *plaintext_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+
+    LOCAL_INPUT_DECLARE(nonce_external, nonce);
+    LOCAL_INPUT_DECLARE(additional_data_external, additional_data);
+    LOCAL_INPUT_DECLARE(ciphertext_external, ciphertext);
+    LOCAL_OUTPUT_DECLARE(plaintext_external, plaintext);
+
+    *plaintext_length = 0;
+
+    status = psa_aead_check_algorithm(alg);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(
+        key, &slot, PSA_KEY_USAGE_DECRYPT, alg);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    LOCAL_INPUT_ALLOC(nonce_external, nonce_length, nonce);
+    LOCAL_INPUT_ALLOC(additional_data_external, additional_data_length,
+                      additional_data);
+    LOCAL_INPUT_ALLOC(ciphertext_external, ciphertext_length, ciphertext);
+    LOCAL_OUTPUT_ALLOC(plaintext_external, plaintext_size, plaintext);
+
+    status = psa_aead_check_nonce_length(alg, nonce_length);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = psa_driver_wrapper_aead_decrypt(
+        &slot->attr, slot->key.data, slot->key.bytes,
+        alg,
+        nonce, nonce_length,
+        additional_data, additional_data_length,
+        ciphertext, ciphertext_length,
+        plaintext, plaintext_size, plaintext_length);
+
+    if (status != PSA_SUCCESS && plaintext_size != 0) {
+        memset(plaintext, 0, plaintext_size);
+    }
+
+exit:
+    LOCAL_INPUT_FREE(nonce_external, nonce);
+    LOCAL_INPUT_FREE(additional_data_external, additional_data);
+    LOCAL_INPUT_FREE(ciphertext_external, ciphertext);
+    LOCAL_OUTPUT_FREE(plaintext_external, plaintext);
+
+    psa_unregister_read_under_mutex(slot);
+
+    return status;
+}
+
+static psa_status_t psa_validate_tag_length(psa_algorithm_t alg)
+{
+    const uint8_t tag_len = PSA_ALG_AEAD_GET_TAG_LENGTH(alg);
+
+    switch (PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg, 0)) {
+#if defined(PSA_WANT_ALG_CCM)
+        case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CCM, 0):
+            /* CCM allows the following tag lengths: 4, 6, 8, 10, 12, 14, 16.*/
+            if (tag_len < 4 || tag_len > 16 || tag_len % 2) {
+                return PSA_ERROR_INVALID_ARGUMENT;
+            }
+            break;
+#endif /* PSA_WANT_ALG_CCM */
+
+#if defined(PSA_WANT_ALG_GCM)
+        case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_GCM, 0):
+            /* GCM allows the following tag lengths: 4, 8, 12, 13, 14, 15, 16. */
+            if (tag_len != 4 && tag_len != 8 && (tag_len < 12 || tag_len > 16)) {
+                return PSA_ERROR_INVALID_ARGUMENT;
+            }
+            break;
+#endif /* PSA_WANT_ALG_GCM */
+
+#if defined(PSA_WANT_ALG_CHACHA20_POLY1305)
+        case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CHACHA20_POLY1305, 0):
+            /* We only support the default tag length. */
+            if (tag_len != 16) {
+                return PSA_ERROR_INVALID_ARGUMENT;
+            }
+            break;
+#endif /* PSA_WANT_ALG_CHACHA20_POLY1305 */
+
+        default:
+            (void) tag_len;
+            return PSA_ERROR_NOT_SUPPORTED;
+    }
+    return PSA_SUCCESS;
+}
+
+/* Set the key for a multipart authenticated operation. */
+static psa_status_t psa_aead_setup(psa_aead_operation_t *operation,
+                                   int is_encrypt,
+                                   mbedtls_svc_key_id_t key,
+                                   psa_algorithm_t alg)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot = NULL;
+    psa_key_usage_t key_usage = 0;
+
+    status = psa_aead_check_algorithm(alg);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    if (operation->id != 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (operation->nonce_set || operation->lengths_set ||
+        operation->ad_started || operation->body_started) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (is_encrypt) {
+        key_usage = PSA_KEY_USAGE_ENCRYPT;
+    } else {
+        key_usage = PSA_KEY_USAGE_DECRYPT;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(key, &slot, key_usage,
+                                                   alg);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    if ((status = psa_validate_tag_length(alg)) != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    if (is_encrypt) {
+        status = psa_driver_wrapper_aead_encrypt_setup(operation,
+                                                       &slot->attr,
+                                                       slot->key.data,
+                                                       slot->key.bytes,
+                                                       alg);
+    } else {
+        status = psa_driver_wrapper_aead_decrypt_setup(operation,
+                                                       &slot->attr,
+                                                       slot->key.data,
+                                                       slot->key.bytes,
+                                                       alg);
+    }
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    operation->key_type = psa_get_key_type(&slot->attr);
+
+exit:
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    if (status == PSA_SUCCESS) {
+        status = unlock_status;
+        operation->alg = psa_aead_get_base_algorithm(alg);
+        operation->is_encrypt = is_encrypt;
+    } else {
+        psa_aead_abort(operation);
+    }
+
+    return status;
+}
+
+/* Set the key for a multipart authenticated encryption operation. */
+psa_status_t psa_aead_encrypt_setup(psa_aead_operation_t *operation,
+                                    mbedtls_svc_key_id_t key,
+                                    psa_algorithm_t alg)
+{
+    return psa_aead_setup(operation, 1, key, alg);
+}
+
+/* Set the key for a multipart authenticated decryption operation. */
+psa_status_t psa_aead_decrypt_setup(psa_aead_operation_t *operation,
+                                    mbedtls_svc_key_id_t key,
+                                    psa_algorithm_t alg)
+{
+    return psa_aead_setup(operation, 0, key, alg);
+}
+
+static psa_status_t psa_aead_set_nonce_internal(psa_aead_operation_t *operation,
+                                                const uint8_t *nonce,
+                                                size_t nonce_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    if (operation->id == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (operation->nonce_set) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    status = psa_aead_check_nonce_length(operation->alg, nonce_length);
+    if (status != PSA_SUCCESS) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    status = psa_driver_wrapper_aead_set_nonce(operation, nonce,
+                                               nonce_length);
+
+exit:
+    if (status == PSA_SUCCESS) {
+        operation->nonce_set = 1;
+    } else {
+        psa_aead_abort(operation);
+    }
+
+    return status;
+}
+
+/* Generate a random nonce / IV for multipart AEAD operation */
+psa_status_t psa_aead_generate_nonce(psa_aead_operation_t *operation,
+                                     uint8_t *nonce_external,
+                                     size_t nonce_size,
+                                     size_t *nonce_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    uint8_t local_nonce[PSA_AEAD_NONCE_MAX_SIZE];
+    size_t required_nonce_size = 0;
+
+    LOCAL_OUTPUT_DECLARE(nonce_external, nonce);
+    LOCAL_OUTPUT_ALLOC(nonce_external, nonce_size, nonce);
+
+    *nonce_length = 0;
+
+    if (operation->id == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (operation->nonce_set || !operation->is_encrypt) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    /* For CCM, this size may not be correct according to the PSA
+     * specification. The PSA Crypto 1.0.1 specification states:
+     *
+     * CCM encodes the plaintext length pLen in L octets, with L the smallest
+     * integer >= 2 where pLen < 2^(8L). The nonce length is then 15 - L bytes.
+     *
+     * However this restriction that L has to be the smallest integer is not
+     * applied in practice, and it is not implementable here since the
+     * plaintext length may or may not be known at this time. */
+    required_nonce_size = PSA_AEAD_NONCE_LENGTH(operation->key_type,
+                                                operation->alg);
+    if (nonce_size < required_nonce_size) {
+        status = PSA_ERROR_BUFFER_TOO_SMALL;
+        goto exit;
+    }
+
+    status = psa_generate_random_internal(local_nonce, required_nonce_size);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = psa_aead_set_nonce_internal(operation, local_nonce,
+                                         required_nonce_size);
+
+exit:
+    if (status == PSA_SUCCESS) {
+        memcpy(nonce, local_nonce, required_nonce_size);
+        *nonce_length = required_nonce_size;
+    } else {
+        psa_aead_abort(operation);
+    }
+
+    LOCAL_OUTPUT_FREE(nonce_external, nonce);
+
+    return status;
+}
+
+/* Set the nonce for a multipart authenticated encryption or decryption
+   operation.*/
+psa_status_t psa_aead_set_nonce(psa_aead_operation_t *operation,
+                                const uint8_t *nonce_external,
+                                size_t nonce_length)
+{
+    psa_status_t status;
+
+    LOCAL_INPUT_DECLARE(nonce_external, nonce);
+    LOCAL_INPUT_ALLOC(nonce_external, nonce_length, nonce);
+
+    status = psa_aead_set_nonce_internal(operation, nonce, nonce_length);
+
+/* Exit label is only needed for buffer copying, prevent unused warnings. */
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+
+    LOCAL_INPUT_FREE(nonce_external, nonce);
+
+    return status;
+}
+
+/* Declare the lengths of the message and additional data for multipart AEAD. */
+psa_status_t psa_aead_set_lengths(psa_aead_operation_t *operation,
+                                  size_t ad_length,
+                                  size_t plaintext_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    if (operation->id == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (operation->lengths_set || operation->ad_started ||
+        operation->body_started) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    switch (operation->alg) {
+#if defined(PSA_WANT_ALG_GCM)
+        case PSA_ALG_GCM:
+            /* Lengths can only be too large for GCM if size_t is bigger than 32
+             * bits. Without the guard this code will generate warnings on 32bit
+             * builds. */
+#if SIZE_MAX > UINT32_MAX
+            if (((uint64_t) ad_length) >> 61 != 0 ||
+                ((uint64_t) plaintext_length) > 0xFFFFFFFE0ull) {
+                status = PSA_ERROR_INVALID_ARGUMENT;
+                goto exit;
+            }
+#endif
+            break;
+#endif /* PSA_WANT_ALG_GCM */
+#if defined(PSA_WANT_ALG_CCM)
+        case PSA_ALG_CCM:
+            if (ad_length > 0xFF00) {
+                status = PSA_ERROR_INVALID_ARGUMENT;
+                goto exit;
+            }
+            break;
+#endif /* PSA_WANT_ALG_CCM */
+#if defined(PSA_WANT_ALG_CHACHA20_POLY1305)
+        case PSA_ALG_CHACHA20_POLY1305:
+            /* No length restrictions for ChaChaPoly. */
+            break;
+#endif /* PSA_WANT_ALG_CHACHA20_POLY1305 */
+        default:
+            break;
+    }
+
+    status = psa_driver_wrapper_aead_set_lengths(operation, ad_length,
+                                                 plaintext_length);
+
+exit:
+    if (status == PSA_SUCCESS) {
+        operation->ad_remaining = ad_length;
+        operation->body_remaining = plaintext_length;
+        operation->lengths_set = 1;
+    } else {
+        psa_aead_abort(operation);
+    }
+
+    return status;
+}
+
+/* Pass additional data to an active multipart AEAD operation. */
+psa_status_t psa_aead_update_ad(psa_aead_operation_t *operation,
+                                const uint8_t *input_external,
+                                size_t input_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+
+    if (operation->id == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (!operation->nonce_set || operation->body_started) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    /* No input to add (zero length), nothing to do. */
+    if (input_length == 0) {
+        status = PSA_SUCCESS;
+        goto exit;
+    }
+
+    if (operation->lengths_set) {
+        if (operation->ad_remaining < input_length) {
+            status = PSA_ERROR_INVALID_ARGUMENT;
+            goto exit;
+        }
+
+        operation->ad_remaining -= input_length;
+    }
+#if defined(PSA_WANT_ALG_CCM)
+    else if (operation->alg == PSA_ALG_CCM) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+#endif /* PSA_WANT_ALG_CCM */
+
+    status = psa_driver_wrapper_aead_update_ad(operation, input,
+                                               input_length);
+
+exit:
+    if (status == PSA_SUCCESS) {
+        operation->ad_started = 1;
+    } else {
+        psa_aead_abort(operation);
+    }
+
+    LOCAL_INPUT_FREE(input_external, input);
+
+    return status;
+}
+
+/* Encrypt or decrypt a message fragment in an active multipart AEAD
+   operation.*/
+psa_status_t psa_aead_update(psa_aead_operation_t *operation,
+                             const uint8_t *input_external,
+                             size_t input_length,
+                             uint8_t *output_external,
+                             size_t output_size,
+                             size_t *output_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_OUTPUT_DECLARE(output_external, output);
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    LOCAL_OUTPUT_ALLOC(output_external, output_size, output);
+
+    *output_length = 0;
+
+    if (operation->id == 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (!operation->nonce_set) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (operation->lengths_set) {
+        /* Additional data length was supplied, but not all the additional
+           data was supplied.*/
+        if (operation->ad_remaining != 0) {
+            status = PSA_ERROR_INVALID_ARGUMENT;
+            goto exit;
+        }
+
+        /* Too much data provided. */
+        if (operation->body_remaining < input_length) {
+            status = PSA_ERROR_INVALID_ARGUMENT;
+            goto exit;
+        }
+
+        operation->body_remaining -= input_length;
+    }
+#if defined(PSA_WANT_ALG_CCM)
+    else if (operation->alg == PSA_ALG_CCM) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+#endif /* PSA_WANT_ALG_CCM */
+
+    status = psa_driver_wrapper_aead_update(operation, input, input_length,
+                                            output, output_size,
+                                            output_length);
+
+exit:
+    if (status == PSA_SUCCESS) {
+        operation->body_started = 1;
+    } else {
+        psa_aead_abort(operation);
+    }
+
+    LOCAL_INPUT_FREE(input_external, input);
+    LOCAL_OUTPUT_FREE(output_external, output);
+
+    return status;
+}
+
+static psa_status_t psa_aead_final_checks(const psa_aead_operation_t *operation)
+{
+    if (operation->id == 0 || !operation->nonce_set) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (operation->lengths_set && (operation->ad_remaining != 0 ||
+                                   operation->body_remaining != 0)) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    return PSA_SUCCESS;
+}
+
+/* Finish encrypting a message in a multipart AEAD operation. */
+psa_status_t psa_aead_finish(psa_aead_operation_t *operation,
+                             uint8_t *ciphertext_external,
+                             size_t ciphertext_size,
+                             size_t *ciphertext_length,
+                             uint8_t *tag_external,
+                             size_t tag_size,
+                             size_t *tag_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    LOCAL_OUTPUT_DECLARE(ciphertext_external, ciphertext);
+    LOCAL_OUTPUT_DECLARE(tag_external, tag);
+
+    LOCAL_OUTPUT_ALLOC(ciphertext_external, ciphertext_size, ciphertext);
+    LOCAL_OUTPUT_ALLOC(tag_external, tag_size, tag);
+
+    *ciphertext_length = 0;
+    *tag_length = tag_size;
+
+    status = psa_aead_final_checks(operation);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    if (!operation->is_encrypt) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    status = psa_driver_wrapper_aead_finish(operation, ciphertext,
+                                            ciphertext_size,
+                                            ciphertext_length,
+                                            tag, tag_size, tag_length);
+
+exit:
+
+
+    /* In case the operation fails and the user fails to check for failure or
+     * the zero tag size, make sure the tag is set to something implausible.
+     * Even if the operation succeeds, make sure we clear the rest of the
+     * buffer to prevent potential leakage of anything previously placed in
+     * the same buffer.*/
+    psa_wipe_tag_output_buffer(tag, status, tag_size, *tag_length);
+
+    psa_aead_abort(operation);
+
+    LOCAL_OUTPUT_FREE(ciphertext_external, ciphertext);
+    LOCAL_OUTPUT_FREE(tag_external, tag);
+
+    return status;
+}
+
+/* Finish authenticating and decrypting a message in a multipart AEAD
+   operation.*/
+psa_status_t psa_aead_verify(psa_aead_operation_t *operation,
+                             uint8_t *plaintext_external,
+                             size_t plaintext_size,
+                             size_t *plaintext_length,
+                             const uint8_t *tag_external,
+                             size_t tag_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    LOCAL_OUTPUT_DECLARE(plaintext_external, plaintext);
+    LOCAL_INPUT_DECLARE(tag_external, tag);
+
+    LOCAL_OUTPUT_ALLOC(plaintext_external, plaintext_size, plaintext);
+    LOCAL_INPUT_ALLOC(tag_external, tag_length, tag);
+
+    *plaintext_length = 0;
+
+    status = psa_aead_final_checks(operation);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    if (operation->is_encrypt) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    status = psa_driver_wrapper_aead_verify(operation, plaintext,
+                                            plaintext_size,
+                                            plaintext_length,
+                                            tag, tag_length);
+
+exit:
+    psa_aead_abort(operation);
+
+    LOCAL_OUTPUT_FREE(plaintext_external, plaintext);
+    LOCAL_INPUT_FREE(tag_external, tag);
+
+    return status;
+}
+
+/* Abort an AEAD operation. */
+psa_status_t psa_aead_abort(psa_aead_operation_t *operation)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    if (operation->id == 0) {
+        /* The object has (apparently) been initialized but it is not (yet)
+         * in use. It's ok to call abort on such an object, and there's
+         * nothing to do. */
+        return PSA_SUCCESS;
+    }
+
+    status = psa_driver_wrapper_aead_abort(operation);
+
+    memset(operation, 0, sizeof(*operation));
+
+    return status;
+}
+
+/****************************************************************/
+/* Generators */
+/****************************************************************/
+
+#if defined(BUILTIN_ALG_ANY_HKDF) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS) || \
+    defined(PSA_HAVE_SOFT_PBKDF2)
+#define AT_LEAST_ONE_BUILTIN_KDF
+#endif /* At least one builtin KDF */
+
+#if defined(BUILTIN_ALG_ANY_HKDF) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
+static psa_status_t psa_key_derivation_start_hmac(
+    psa_mac_operation_t *operation,
+    psa_algorithm_t hash_alg,
+    const uint8_t *hmac_key,
+    size_t hmac_key_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
+    psa_set_key_type(&attributes, PSA_KEY_TYPE_HMAC);
+    psa_set_key_bits(&attributes, PSA_BYTES_TO_BITS(hmac_key_length));
+    psa_set_key_usage_flags(&attributes, PSA_KEY_USAGE_SIGN_HASH);
+
+    operation->is_sign = 1;
+    operation->mac_size = PSA_HASH_LENGTH(hash_alg);
+
+    status = psa_driver_wrapper_mac_sign_setup(operation,
+                                               &attributes,
+                                               hmac_key, hmac_key_length,
+                                               PSA_ALG_HMAC(hash_alg));
+
+    psa_reset_key_attributes(&attributes);
+    return status;
+}
+#endif /* KDF algorithms reliant on HMAC */
+
+#define HKDF_STATE_INIT 0 /* no input yet */
+#define HKDF_STATE_STARTED 1 /* got salt */
+#define HKDF_STATE_KEYED 2 /* got key */
+#define HKDF_STATE_OUTPUT 3 /* output started */
+
+static psa_algorithm_t psa_key_derivation_get_kdf_alg(
+    const psa_key_derivation_operation_t *operation)
+{
+    if (PSA_ALG_IS_KEY_AGREEMENT(operation->alg)) {
+        return PSA_ALG_KEY_AGREEMENT_GET_KDF(operation->alg);
+    } else {
+        return operation->alg;
+    }
+}
+
+psa_status_t psa_key_derivation_abort(psa_key_derivation_operation_t *operation)
+{
+    psa_status_t status = PSA_SUCCESS;
+    psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg(operation);
+    if (kdf_alg == 0) {
+        /* The object has (apparently) been initialized but it is not
+         * in use. It's ok to call abort on such an object, and there's
+         * nothing to do. */
+    } else
+#if defined(BUILTIN_ALG_ANY_HKDF)
+    if (PSA_ALG_IS_ANY_HKDF(kdf_alg)) {
+        mbedtls_free(operation->ctx.hkdf.info);
+        status = psa_mac_abort(&operation->ctx.hkdf.hmac);
+    } else
+#endif /* BUILTIN_ALG_ANY_HKDF */
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
+    if (PSA_ALG_IS_TLS12_PRF(kdf_alg) ||
+        /* TLS-1.2 PSK-to-MS KDF uses the same core as TLS-1.2 PRF */
+        PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg)) {
+        if (operation->ctx.tls12_prf.secret != NULL) {
+            mbedtls_zeroize_and_free(operation->ctx.tls12_prf.secret,
+                                     operation->ctx.tls12_prf.secret_length);
+        }
+
+        if (operation->ctx.tls12_prf.seed != NULL) {
+            mbedtls_zeroize_and_free(operation->ctx.tls12_prf.seed,
+                                     operation->ctx.tls12_prf.seed_length);
+        }
+
+        if (operation->ctx.tls12_prf.label != NULL) {
+            mbedtls_zeroize_and_free(operation->ctx.tls12_prf.label,
+                                     operation->ctx.tls12_prf.label_length);
+        }
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
+        if (operation->ctx.tls12_prf.other_secret != NULL) {
+            mbedtls_zeroize_and_free(operation->ctx.tls12_prf.other_secret,
+                                     operation->ctx.tls12_prf.other_secret_length);
+        }
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
+        status = PSA_SUCCESS;
+
+        /* We leave the fields Ai and output_block to be erased safely by the
+         * mbedtls_platform_zeroize() in the end of this function. */
+    } else
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) ||
+        * defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) */
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS)
+    if (kdf_alg == PSA_ALG_TLS12_ECJPAKE_TO_PMS) {
+        mbedtls_platform_zeroize(operation->ctx.tls12_ecjpake_to_pms.data,
+                                 sizeof(operation->ctx.tls12_ecjpake_to_pms.data));
+    } else
+#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS) */
+#if defined(PSA_HAVE_SOFT_PBKDF2)
+    if (PSA_ALG_IS_PBKDF2(kdf_alg)) {
+        if (operation->ctx.pbkdf2.salt != NULL) {
+            mbedtls_zeroize_and_free(operation->ctx.pbkdf2.salt,
+                                     operation->ctx.pbkdf2.salt_length);
+        }
+
+        status = PSA_SUCCESS;
+    } else
+#endif /* defined(PSA_HAVE_SOFT_PBKDF2) */
+    {
+        status = PSA_ERROR_BAD_STATE;
+    }
+    mbedtls_platform_zeroize(operation, sizeof(*operation));
+    return status;
+}
+
+psa_status_t psa_key_derivation_get_capacity(const psa_key_derivation_operation_t *operation,
+                                             size_t *capacity)
+{
+    if (operation->alg == 0) {
+        /* This is a blank key derivation operation. */
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    *capacity = operation->capacity;
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_key_derivation_set_capacity(psa_key_derivation_operation_t *operation,
+                                             size_t capacity)
+{
+    if (operation->alg == 0) {
+        return PSA_ERROR_BAD_STATE;
+    }
+    if (capacity > operation->capacity) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+    operation->capacity = capacity;
+    return PSA_SUCCESS;
+}
+
+#if defined(BUILTIN_ALG_ANY_HKDF)
+/* Read some bytes from an HKDF-based operation. */
+static psa_status_t psa_key_derivation_hkdf_read(psa_hkdf_key_derivation_t *hkdf,
+                                                 psa_algorithm_t kdf_alg,
+                                                 uint8_t *output,
+                                                 size_t output_length)
+{
+    psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH(kdf_alg);
+    uint8_t hash_length = PSA_HASH_LENGTH(hash_alg);
+    size_t hmac_output_length;
+    psa_status_t status;
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT)
+    const uint8_t last_block = PSA_ALG_IS_HKDF_EXTRACT(kdf_alg) ? 0 : 0xff;
+#else
+    const uint8_t last_block = 0xff;
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT */
+
+    if (hkdf->state < HKDF_STATE_KEYED ||
+        (!hkdf->info_set
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT)
+         && !PSA_ALG_IS_HKDF_EXTRACT(kdf_alg)
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT */
+        )) {
+        return PSA_ERROR_BAD_STATE;
+    }
+    hkdf->state = HKDF_STATE_OUTPUT;
+
+    while (output_length != 0) {
+        /* Copy what remains of the current block */
+        uint8_t n = hash_length - hkdf->offset_in_block;
+        if (n > output_length) {
+            n = (uint8_t) output_length;
+        }
+        memcpy(output, hkdf->output_block + hkdf->offset_in_block, n);
+        output += n;
+        output_length -= n;
+        hkdf->offset_in_block += n;
+        if (output_length == 0) {
+            break;
+        }
+        /* We can't be wanting more output after the last block, otherwise
+         * the capacity check in psa_key_derivation_output_bytes() would have
+         * prevented this call. It could happen only if the operation
+         * object was corrupted or if this function is called directly
+         * inside the library. */
+        if (hkdf->block_number == last_block) {
+            return PSA_ERROR_BAD_STATE;
+        }
+
+        /* We need a new block */
+        ++hkdf->block_number;
+        hkdf->offset_in_block = 0;
+
+        status = psa_key_derivation_start_hmac(&hkdf->hmac,
+                                               hash_alg,
+                                               hkdf->prk,
+                                               hash_length);
+        if (status != PSA_SUCCESS) {
+            return status;
+        }
+
+        if (hkdf->block_number != 1) {
+            status = psa_mac_update(&hkdf->hmac,
+                                    hkdf->output_block,
+                                    hash_length);
+            if (status != PSA_SUCCESS) {
+                return status;
+            }
+        }
+        status = psa_mac_update(&hkdf->hmac,
+                                hkdf->info,
+                                hkdf->info_length);
+        if (status != PSA_SUCCESS) {
+            return status;
+        }
+        status = psa_mac_update(&hkdf->hmac,
+                                &hkdf->block_number, 1);
+        if (status != PSA_SUCCESS) {
+            return status;
+        }
+        status = psa_mac_sign_finish(&hkdf->hmac,
+                                     hkdf->output_block,
+                                     sizeof(hkdf->output_block),
+                                     &hmac_output_length);
+        if (status != PSA_SUCCESS) {
+            return status;
+        }
+    }
+
+    return PSA_SUCCESS;
+}
+#endif /* BUILTIN_ALG_ANY_HKDF */
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
+static psa_status_t psa_key_derivation_tls12_prf_generate_next_block(
+    psa_tls12_prf_key_derivation_t *tls12_prf,
+    psa_algorithm_t alg)
+{
+    psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH(alg);
+    uint8_t hash_length = PSA_HASH_LENGTH(hash_alg);
+    psa_mac_operation_t hmac = PSA_MAC_OPERATION_INIT;
+    size_t hmac_output_length;
+    psa_status_t status, cleanup_status;
+
+    /* We can't be wanting more output after block 0xff, otherwise
+     * the capacity check in psa_key_derivation_output_bytes() would have
+     * prevented this call. It could happen only if the operation
+     * object was corrupted or if this function is called directly
+     * inside the library. */
+    if (tls12_prf->block_number == 0xff) {
+        return PSA_ERROR_CORRUPTION_DETECTED;
+    }
+
+    /* We need a new block */
+    ++tls12_prf->block_number;
+    tls12_prf->left_in_block = hash_length;
+
+    /* Recall the definition of the TLS-1.2-PRF from RFC 5246:
+     *
+     * PRF(secret, label, seed) = P_<hash>(secret, label + seed)
+     *
+     * P_hash(secret, seed) = HMAC_hash(secret, A(1) + seed) +
+     *                        HMAC_hash(secret, A(2) + seed) +
+     *                        HMAC_hash(secret, A(3) + seed) + ...
+     *
+     * A(0) = seed
+     * A(i) = HMAC_hash(secret, A(i-1))
+     *
+     * The `psa_tls12_prf_key_derivation` structure saves the block
+     * `HMAC_hash(secret, A(i) + seed)` from which the output
+     * is currently extracted as `output_block` and where i is
+     * `block_number`.
+     */
+
+    status = psa_key_derivation_start_hmac(&hmac,
+                                           hash_alg,
+                                           tls12_prf->secret,
+                                           tls12_prf->secret_length);
+    if (status != PSA_SUCCESS) {
+        goto cleanup;
+    }
+
+    /* Calculate A(i) where i = tls12_prf->block_number. */
+    if (tls12_prf->block_number == 1) {
+        /* A(1) = HMAC_hash(secret, A(0)), where A(0) = seed. (The RFC overloads
+         * the variable seed and in this instance means it in the context of the
+         * P_hash function, where seed = label + seed.) */
+        status = psa_mac_update(&hmac,
+                                tls12_prf->label,
+                                tls12_prf->label_length);
+        if (status != PSA_SUCCESS) {
+            goto cleanup;
+        }
+        status = psa_mac_update(&hmac,
+                                tls12_prf->seed,
+                                tls12_prf->seed_length);
+        if (status != PSA_SUCCESS) {
+            goto cleanup;
+        }
+    } else {
+        /* A(i) = HMAC_hash(secret, A(i-1)) */
+        status = psa_mac_update(&hmac, tls12_prf->Ai, hash_length);
+        if (status != PSA_SUCCESS) {
+            goto cleanup;
+        }
+    }
+
+    status = psa_mac_sign_finish(&hmac,
+                                 tls12_prf->Ai, hash_length,
+                                 &hmac_output_length);
+    if (hmac_output_length != hash_length) {
+        status = PSA_ERROR_CORRUPTION_DETECTED;
+    }
+    if (status != PSA_SUCCESS) {
+        goto cleanup;
+    }
+
+    /* Calculate HMAC_hash(secret, A(i) + label + seed). */
+    status = psa_key_derivation_start_hmac(&hmac,
+                                           hash_alg,
+                                           tls12_prf->secret,
+                                           tls12_prf->secret_length);
+    if (status != PSA_SUCCESS) {
+        goto cleanup;
+    }
+    status = psa_mac_update(&hmac, tls12_prf->Ai, hash_length);
+    if (status != PSA_SUCCESS) {
+        goto cleanup;
+    }
+    status = psa_mac_update(&hmac, tls12_prf->label, tls12_prf->label_length);
+    if (status != PSA_SUCCESS) {
+        goto cleanup;
+    }
+    status = psa_mac_update(&hmac, tls12_prf->seed, tls12_prf->seed_length);
+    if (status != PSA_SUCCESS) {
+        goto cleanup;
+    }
+    status = psa_mac_sign_finish(&hmac,
+                                 tls12_prf->output_block, hash_length,
+                                 &hmac_output_length);
+    if (status != PSA_SUCCESS) {
+        goto cleanup;
+    }
+
+
+cleanup:
+    cleanup_status = psa_mac_abort(&hmac);
+    if (status == PSA_SUCCESS && cleanup_status != PSA_SUCCESS) {
+        status = cleanup_status;
+    }
+
+    return status;
+}
+
+static psa_status_t psa_key_derivation_tls12_prf_read(
+    psa_tls12_prf_key_derivation_t *tls12_prf,
+    psa_algorithm_t alg,
+    uint8_t *output,
+    size_t output_length)
+{
+    psa_algorithm_t hash_alg = PSA_ALG_TLS12_PRF_GET_HASH(alg);
+    uint8_t hash_length = PSA_HASH_LENGTH(hash_alg);
+    psa_status_t status;
+    uint8_t offset, length;
+
+    switch (tls12_prf->state) {
+        case PSA_TLS12_PRF_STATE_LABEL_SET:
+            tls12_prf->state = PSA_TLS12_PRF_STATE_OUTPUT;
+            break;
+        case PSA_TLS12_PRF_STATE_OUTPUT:
+            break;
+        default:
+            return PSA_ERROR_BAD_STATE;
+    }
+
+    while (output_length != 0) {
+        /* Check if we have fully processed the current block. */
+        if (tls12_prf->left_in_block == 0) {
+            status = psa_key_derivation_tls12_prf_generate_next_block(tls12_prf,
+                                                                      alg);
+            if (status != PSA_SUCCESS) {
+                return status;
+            }
+
+            continue;
+        }
+
+        if (tls12_prf->left_in_block > output_length) {
+            length = (uint8_t) output_length;
+        } else {
+            length = tls12_prf->left_in_block;
+        }
+
+        offset = hash_length - tls12_prf->left_in_block;
+        memcpy(output, tls12_prf->output_block + offset, length);
+        output += length;
+        output_length -= length;
+        tls12_prf->left_in_block -= length;
+    }
+
+    return PSA_SUCCESS;
+}
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF ||
+        * MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS)
+static psa_status_t psa_key_derivation_tls12_ecjpake_to_pms_read(
+    psa_tls12_ecjpake_to_pms_t *ecjpake,
+    uint8_t *output,
+    size_t output_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    size_t output_size = 0;
+
+    if (output_length != 32) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    status = psa_hash_compute(PSA_ALG_SHA_256, ecjpake->data,
+                              PSA_TLS12_ECJPAKE_TO_PMS_DATA_SIZE, output, output_length,
+                              &output_size);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    if (output_size != output_length) {
+        return PSA_ERROR_GENERIC_ERROR;
+    }
+
+    return PSA_SUCCESS;
+}
+#endif
+
+#if defined(PSA_HAVE_SOFT_PBKDF2)
+static psa_status_t psa_key_derivation_pbkdf2_generate_block(
+    psa_pbkdf2_key_derivation_t *pbkdf2,
+    psa_algorithm_t prf_alg,
+    uint8_t prf_output_length,
+    psa_key_attributes_t *attributes)
+{
+    psa_status_t status;
+    psa_mac_operation_t mac_operation = PSA_MAC_OPERATION_INIT;
+    size_t mac_output_length;
+    uint8_t U_i[PSA_MAC_MAX_SIZE];
+    uint8_t *U_accumulator = pbkdf2->output_block;
+    uint64_t i;
+    uint8_t block_counter[4];
+
+    mac_operation.is_sign = 1;
+    mac_operation.mac_size = prf_output_length;
+    MBEDTLS_PUT_UINT32_BE(pbkdf2->block_number, block_counter, 0);
+
+    status = psa_driver_wrapper_mac_sign_setup(&mac_operation,
+                                               attributes,
+                                               pbkdf2->password,
+                                               pbkdf2->password_length,
+                                               prf_alg);
+    if (status != PSA_SUCCESS) {
+        goto cleanup;
+    }
+    status = psa_mac_update(&mac_operation, pbkdf2->salt, pbkdf2->salt_length);
+    if (status != PSA_SUCCESS) {
+        goto cleanup;
+    }
+    status = psa_mac_update(&mac_operation, block_counter, sizeof(block_counter));
+    if (status != PSA_SUCCESS) {
+        goto cleanup;
+    }
+    status = psa_mac_sign_finish(&mac_operation, U_i, sizeof(U_i),
+                                 &mac_output_length);
+    if (status != PSA_SUCCESS) {
+        goto cleanup;
+    }
+
+    if (mac_output_length != prf_output_length) {
+        status = PSA_ERROR_CORRUPTION_DETECTED;
+        goto cleanup;
+    }
+
+    memcpy(U_accumulator, U_i, prf_output_length);
+
+    for (i = 1; i < pbkdf2->input_cost; i++) {
+        /* We are passing prf_output_length as mac_size because the driver
+         * function directly sets mac_output_length as mac_size upon success.
+         * See https://github.com/Mbed-TLS/mbedtls/issues/7801 */
+        status = psa_driver_wrapper_mac_compute(attributes,
+                                                pbkdf2->password,
+                                                pbkdf2->password_length,
+                                                prf_alg, U_i, prf_output_length,
+                                                U_i, prf_output_length,
+                                                &mac_output_length);
+        if (status != PSA_SUCCESS) {
+            goto cleanup;
+        }
+
+        mbedtls_xor(U_accumulator, U_accumulator, U_i, prf_output_length);
+    }
+
+cleanup:
+    /* Zeroise buffers to clear sensitive data from memory. */
+    mbedtls_platform_zeroize(U_i, PSA_MAC_MAX_SIZE);
+    return status;
+}
+
+static psa_status_t psa_key_derivation_pbkdf2_read(
+    psa_pbkdf2_key_derivation_t *pbkdf2,
+    psa_algorithm_t kdf_alg,
+    uint8_t *output,
+    size_t output_length)
+{
+    psa_status_t status;
+    psa_algorithm_t prf_alg;
+    uint8_t prf_output_length;
+    psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
+    psa_set_key_bits(&attributes, PSA_BYTES_TO_BITS(pbkdf2->password_length));
+    psa_set_key_usage_flags(&attributes, PSA_KEY_USAGE_SIGN_MESSAGE);
+
+    if (PSA_ALG_IS_PBKDF2_HMAC(kdf_alg)) {
+        prf_alg = PSA_ALG_HMAC(PSA_ALG_PBKDF2_HMAC_GET_HASH(kdf_alg));
+        prf_output_length = PSA_HASH_LENGTH(prf_alg);
+        psa_set_key_type(&attributes, PSA_KEY_TYPE_HMAC);
+    } else if (kdf_alg == PSA_ALG_PBKDF2_AES_CMAC_PRF_128) {
+        prf_alg = PSA_ALG_CMAC;
+        prf_output_length = PSA_MAC_LENGTH(PSA_KEY_TYPE_AES, 128U, PSA_ALG_CMAC);
+        psa_set_key_type(&attributes, PSA_KEY_TYPE_AES);
+    } else {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    switch (pbkdf2->state) {
+        case PSA_PBKDF2_STATE_PASSWORD_SET:
+            /* Initially we need a new block so bytes_used is equal to block size*/
+            pbkdf2->bytes_used = prf_output_length;
+            pbkdf2->state = PSA_PBKDF2_STATE_OUTPUT;
+            break;
+        case PSA_PBKDF2_STATE_OUTPUT:
+            break;
+        default:
+            return PSA_ERROR_BAD_STATE;
+    }
+
+    while (output_length != 0) {
+        uint8_t n = prf_output_length - pbkdf2->bytes_used;
+        if (n > output_length) {
+            n = (uint8_t) output_length;
+        }
+        memcpy(output, pbkdf2->output_block + pbkdf2->bytes_used, n);
+        output += n;
+        output_length -= n;
+        pbkdf2->bytes_used += n;
+
+        if (output_length == 0) {
+            break;
+        }
+
+        /* We need a new block */
+        pbkdf2->bytes_used = 0;
+        pbkdf2->block_number++;
+
+        status = psa_key_derivation_pbkdf2_generate_block(pbkdf2, prf_alg,
+                                                          prf_output_length,
+                                                          &attributes);
+        if (status != PSA_SUCCESS) {
+            return status;
+        }
+    }
+
+    return PSA_SUCCESS;
+}
+#endif /* PSA_HAVE_SOFT_PBKDF2 */
+
+psa_status_t psa_key_derivation_output_bytes(
+    psa_key_derivation_operation_t *operation,
+    uint8_t *output_external,
+    size_t output_length)
+{
+    psa_status_t status;
+    LOCAL_OUTPUT_DECLARE(output_external, output);
+
+    psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg(operation);
+
+    if (operation->alg == 0) {
+        /* This is a blank operation. */
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (output_length == 0 && operation->capacity == 0) {
+        /* Edge case: this is a finished operation, and 0 bytes
+         * were requested. The right error in this case could
+         * be either INSUFFICIENT_CAPACITY or BAD_STATE. Return
+         * INSUFFICIENT_CAPACITY, which is right for a finished
+         * operation, for consistency with the case when
+         * output_length > 0. */
+        return PSA_ERROR_INSUFFICIENT_DATA;
+    }
+
+    LOCAL_OUTPUT_ALLOC(output_external, output_length, output);
+    if (output_length > operation->capacity) {
+        operation->capacity = 0;
+        /* Go through the error path to wipe all confidential data now
+         * that the operation object is useless. */
+        status = PSA_ERROR_INSUFFICIENT_DATA;
+        goto exit;
+    }
+
+    operation->capacity -= output_length;
+
+#if defined(BUILTIN_ALG_ANY_HKDF)
+    if (PSA_ALG_IS_ANY_HKDF(kdf_alg)) {
+        status = psa_key_derivation_hkdf_read(&operation->ctx.hkdf, kdf_alg,
+                                              output, output_length);
+    } else
+#endif /* BUILTIN_ALG_ANY_HKDF */
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
+    if (PSA_ALG_IS_TLS12_PRF(kdf_alg) ||
+        PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg)) {
+        status = psa_key_derivation_tls12_prf_read(&operation->ctx.tls12_prf,
+                                                   kdf_alg, output,
+                                                   output_length);
+    } else
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF ||
+        * MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS)
+    if (kdf_alg == PSA_ALG_TLS12_ECJPAKE_TO_PMS) {
+        status = psa_key_derivation_tls12_ecjpake_to_pms_read(
+            &operation->ctx.tls12_ecjpake_to_pms, output, output_length);
+    } else
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS */
+#if defined(PSA_HAVE_SOFT_PBKDF2)
+    if (PSA_ALG_IS_PBKDF2(kdf_alg)) {
+        status = psa_key_derivation_pbkdf2_read(&operation->ctx.pbkdf2, kdf_alg,
+                                                output, output_length);
+    } else
+#endif /* PSA_HAVE_SOFT_PBKDF2 */
+
+    {
+        (void) kdf_alg;
+        status = PSA_ERROR_BAD_STATE;
+        LOCAL_OUTPUT_FREE(output_external, output);
+
+        return status;
+    }
+
+exit:
+    if (status != PSA_SUCCESS) {
+        /* Preserve the algorithm upon errors, but clear all sensitive state.
+         * This allows us to differentiate between exhausted operations and
+         * blank operations, so we can return PSA_ERROR_BAD_STATE on blank
+         * operations. */
+        psa_algorithm_t alg = operation->alg;
+        psa_key_derivation_abort(operation);
+        operation->alg = alg;
+        if (output != NULL) {
+            memset(output, '!', output_length);
+        }
+    }
+
+    LOCAL_OUTPUT_FREE(output_external, output);
+    return status;
+}
+
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES)
+static void psa_des_set_key_parity(uint8_t *data, size_t data_size)
+{
+    if (data_size >= 8) {
+        mbedtls_des_key_set_parity(data);
+    }
+    if (data_size >= 16) {
+        mbedtls_des_key_set_parity(data + 8);
+    }
+    if (data_size >= 24) {
+        mbedtls_des_key_set_parity(data + 16);
+    }
+}
+#endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES */
+
+/*
+ * ECC keys on a Weierstrass elliptic curve require the generation
+ * of a private key which is an integer
+ * in the range [1, N - 1], where N is the boundary of the private key domain:
+ * N is the prime p for Diffie-Hellman, or the order of the
+ * curve’s base point for ECC.
+ *
+ * Let m be the bit size of N, such that 2^m > N >= 2^(m-1).
+ * This function generates the private key using the following process:
+ *
+ * 1. Draw a byte string of length ceiling(m/8) bytes.
+ * 2. If m is not a multiple of 8, set the most significant
+ *    (8 * ceiling(m/8) - m) bits of the first byte in the string to zero.
+ * 3. Convert the string to integer k by decoding it as a big-endian byte string.
+ * 4. If k > N - 2, discard the result and return to step 1.
+ * 5. Output k + 1 as the private key.
+ *
+ * This method allows compliance to NIST standards, specifically the methods titled
+ * Key-Pair Generation by Testing Candidates in the following publications:
+ * - NIST Special Publication 800-56A: Recommendation for Pair-Wise Key-Establishment
+ *   Schemes Using Discrete Logarithm Cryptography [SP800-56A] §5.6.1.1.4 for
+ *   Diffie-Hellman keys.
+ *
+ * - [SP800-56A] §5.6.1.2.2 or FIPS Publication 186-4: Digital Signature
+ *   Standard (DSS) [FIPS186-4] §B.4.2 for elliptic curve keys.
+ *
+ * Note: Function allocates memory for *data buffer, so given *data should be
+ *       always NULL.
+ */
+#if defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR_DERIVE)
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_DERIVE)
+static psa_status_t psa_generate_derived_ecc_key_weierstrass_helper(
+    psa_key_slot_t *slot,
+    size_t bits,
+    psa_key_derivation_operation_t *operation,
+    uint8_t **data
+    )
+{
+    unsigned key_out_of_range = 1;
+    mbedtls_mpi k;
+    mbedtls_mpi diff_N_2;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    size_t m;
+    size_t m_bytes;
+
+    mbedtls_mpi_init(&k);
+    mbedtls_mpi_init(&diff_N_2);
+
+    psa_ecc_family_t curve = PSA_KEY_TYPE_ECC_GET_FAMILY(
+        slot->attr.type);
+    mbedtls_ecp_group_id grp_id =
+        mbedtls_ecc_group_from_psa(curve, bits);
+
+    if (grp_id == MBEDTLS_ECP_DP_NONE) {
+        ret = MBEDTLS_ERR_ASN1_INVALID_DATA;
+        goto cleanup;
+    }
+
+    mbedtls_ecp_group ecp_group;
+    mbedtls_ecp_group_init(&ecp_group);
+
+    MBEDTLS_MPI_CHK(mbedtls_ecp_group_load(&ecp_group, grp_id));
+
+    /* N is the boundary of the private key domain (ecp_group.N). */
+    /* Let m be the bit size of N. */
+    m = ecp_group.nbits;
+
+    m_bytes = PSA_BITS_TO_BYTES(m);
+
+    /* Calculate N - 2 - it will be needed later. */
+    MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&diff_N_2, &ecp_group.N, 2));
+
+    /* Note: This function is always called with *data == NULL and it
+     * allocates memory for the data buffer. */
+    *data = mbedtls_calloc(1, m_bytes);
+    if (*data == NULL) {
+        ret = MBEDTLS_ERR_ASN1_ALLOC_FAILED;
+        goto cleanup;
+    }
+
+    while (key_out_of_range) {
+        /* 1. Draw a byte string of length ceiling(m/8) bytes. */
+        if ((status = psa_key_derivation_output_bytes(operation, *data, m_bytes)) != 0) {
+            goto cleanup;
+        }
+
+        /* 2. If m is not a multiple of 8 */
+        if (m % 8 != 0) {
+            /* Set the most significant
+             * (8 * ceiling(m/8) - m) bits of the first byte in
+             * the string to zero.
+             */
+            uint8_t clear_bit_mask = (1 << (m % 8)) - 1;
+            (*data)[0] &= clear_bit_mask;
+        }
+
+        /* 3. Convert the string to integer k by decoding it as a
+         *    big-endian byte string.
+         */
+        MBEDTLS_MPI_CHK(mbedtls_mpi_read_binary(&k, *data, m_bytes));
+
+        /* 4. If k > N - 2, discard the result and return to step 1.
+         *    Result of comparison is returned. When it indicates error
+         *    then this function is called again.
+         */
+        MBEDTLS_MPI_CHK(mbedtls_mpi_lt_mpi_ct(&diff_N_2, &k, &key_out_of_range));
+    }
+
+    /* 5. Output k + 1 as the private key. */
+    MBEDTLS_MPI_CHK(mbedtls_mpi_add_int(&k, &k, 1));
+    MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&k, *data, m_bytes));
+cleanup:
+    if (ret != 0) {
+        status = mbedtls_to_psa_error(ret);
+    }
+    if (status != PSA_SUCCESS) {
+        mbedtls_free(*data);
+        *data = NULL;
+    }
+    mbedtls_mpi_free(&k);
+    mbedtls_mpi_free(&diff_N_2);
+    return status;
+}
+
+/* ECC keys on a Montgomery elliptic curve draws a byte string whose length
+ * is determined by the curve, and sets the mandatory bits accordingly. That is:
+ *
+ * - Curve25519 (PSA_ECC_FAMILY_MONTGOMERY, 255 bits):
+ *   draw a 32-byte string and process it as specified in
+ *   Elliptic Curves for Security [RFC7748] §5.
+ *
+ * - Curve448 (PSA_ECC_FAMILY_MONTGOMERY, 448 bits):
+ *   draw a 56-byte string and process it as specified in [RFC7748] §5.
+ *
+ * Note: Function allocates memory for *data buffer, so given *data should be
+ *       always NULL.
+ */
+
+static psa_status_t psa_generate_derived_ecc_key_montgomery_helper(
+    size_t bits,
+    psa_key_derivation_operation_t *operation,
+    uint8_t **data
+    )
+{
+    size_t output_length;
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    switch (bits) {
+        case 255:
+            output_length = 32;
+            break;
+        case 448:
+            output_length = 56;
+            break;
+        default:
+            return PSA_ERROR_INVALID_ARGUMENT;
+            break;
+    }
+
+    *data = mbedtls_calloc(1, output_length);
+
+    if (*data == NULL) {
+        return PSA_ERROR_INSUFFICIENT_MEMORY;
+    }
+
+    status = psa_key_derivation_output_bytes(operation, *data, output_length);
+
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    switch (bits) {
+        case 255:
+            (*data)[0] &= 248;
+            (*data)[31] &= 127;
+            (*data)[31] |= 64;
+            break;
+        case 448:
+            (*data)[0] &= 252;
+            (*data)[55] |= 128;
+            break;
+        default:
+            return PSA_ERROR_CORRUPTION_DETECTED;
+            break;
+    }
+
+    return status;
+}
+#else /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_DERIVE */
+static psa_status_t psa_generate_derived_ecc_key_weierstrass_helper(
+    psa_key_slot_t *slot, size_t bits,
+    psa_key_derivation_operation_t *operation, uint8_t **data)
+{
+    (void) slot;
+    (void) bits;
+    (void) operation;
+    (void) data;
+    return PSA_ERROR_NOT_SUPPORTED;
+}
+
+static psa_status_t psa_generate_derived_ecc_key_montgomery_helper(
+    size_t bits, psa_key_derivation_operation_t *operation, uint8_t **data)
+{
+    (void) bits;
+    (void) operation;
+    (void) data;
+    return PSA_ERROR_NOT_SUPPORTED;
+}
+#endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_DERIVE */
+#endif /* PSA_WANT_KEY_TYPE_ECC_KEY_PAIR_DERIVE */
+
+static psa_status_t psa_generate_derived_key_internal(
+    psa_key_slot_t *slot,
+    size_t bits,
+    psa_key_derivation_operation_t *operation)
+{
+    uint8_t *data = NULL;
+    size_t bytes = PSA_BITS_TO_BYTES(bits);
+    size_t storage_size = bytes;
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    if (PSA_KEY_TYPE_IS_PUBLIC_KEY(slot->attr.type)) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+#if defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR_DERIVE) || \
+    defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_DERIVE)
+    if (PSA_KEY_TYPE_IS_ECC(slot->attr.type)) {
+        psa_ecc_family_t curve = PSA_KEY_TYPE_ECC_GET_FAMILY(slot->attr.type);
+        if (PSA_ECC_FAMILY_IS_WEIERSTRASS(curve)) {
+            /* Weierstrass elliptic curve */
+            status = psa_generate_derived_ecc_key_weierstrass_helper(slot, bits, operation, &data);
+            if (status != PSA_SUCCESS) {
+                goto exit;
+            }
+        } else {
+            /* Montgomery elliptic curve */
+            status = psa_generate_derived_ecc_key_montgomery_helper(bits, operation, &data);
+            if (status != PSA_SUCCESS) {
+                goto exit;
+            }
+        }
+    } else
+#endif /* defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR_DERIVE) ||
+          defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_DERIVE) */
+    if (key_type_is_raw_bytes(slot->attr.type)) {
+        if (bits % 8 != 0) {
+            return PSA_ERROR_INVALID_ARGUMENT;
+        }
+        data = mbedtls_calloc(1, bytes);
+        if (data == NULL) {
+            return PSA_ERROR_INSUFFICIENT_MEMORY;
+        }
+
+        status = psa_key_derivation_output_bytes(operation, data, bytes);
+        if (status != PSA_SUCCESS) {
+            goto exit;
+        }
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES)
+        if (slot->attr.type == PSA_KEY_TYPE_DES) {
+            psa_des_set_key_parity(data, bytes);
+        }
+#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES) */
+    } else {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    slot->attr.bits = (psa_key_bits_t) bits;
+
+    if (psa_key_lifetime_is_external(slot->attr.lifetime)) {
+        status = psa_driver_wrapper_get_key_buffer_size(&slot->attr,
+                                                        &storage_size);
+        if (status != PSA_SUCCESS) {
+            goto exit;
+        }
+    }
+    status = psa_allocate_buffer_to_slot(slot, storage_size);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = psa_driver_wrapper_import_key(&slot->attr,
+                                           data, bytes,
+                                           slot->key.data,
+                                           slot->key.bytes,
+                                           &slot->key.bytes, &bits);
+    if (bits != slot->attr.bits) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+exit:
+    mbedtls_free(data);
+    return status;
+}
+
+static const psa_custom_key_parameters_t default_custom_production =
+    PSA_CUSTOM_KEY_PARAMETERS_INIT;
+
+int psa_custom_key_parameters_are_default(
+    const psa_custom_key_parameters_t *custom,
+    size_t custom_data_length)
+{
+    if (custom->flags != 0) {
+        return 0;
+    }
+    if (custom_data_length != 0) {
+        return 0;
+    }
+    return 1;
+}
+
+psa_status_t psa_key_derivation_output_key_custom(
+    const psa_key_attributes_t *attributes,
+    psa_key_derivation_operation_t *operation,
+    const psa_custom_key_parameters_t *custom,
+    const uint8_t *custom_data,
+    size_t custom_data_length,
+    mbedtls_svc_key_id_t *key)
+{
+    psa_status_t status;
+    psa_key_slot_t *slot = NULL;
+    psa_se_drv_table_entry_t *driver = NULL;
+
+    *key = MBEDTLS_SVC_KEY_ID_INIT;
+
+    /* Reject any attempt to create a zero-length key so that we don't
+     * risk tripping up later, e.g. on a malloc(0) that returns NULL. */
+    if (psa_get_key_bits(attributes) == 0) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    (void) custom_data;         /* We only accept 0-length data */
+    if (!psa_custom_key_parameters_are_default(custom, custom_data_length)) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    if (operation->alg == PSA_ALG_NONE) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (!operation->can_output_key) {
+        return PSA_ERROR_NOT_PERMITTED;
+    }
+
+    status = psa_start_key_creation(PSA_KEY_CREATION_DERIVE, attributes,
+                                    &slot, &driver);
+#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
+    if (driver != NULL) {
+        /* Deriving a key in a secure element is not implemented yet. */
+        status = PSA_ERROR_NOT_SUPPORTED;
+    }
+#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
+    if (status == PSA_SUCCESS) {
+        status = psa_generate_derived_key_internal(slot,
+                                                   attributes->bits,
+                                                   operation);
+    }
+    if (status == PSA_SUCCESS) {
+        status = psa_finish_key_creation(slot, driver, key);
+    }
+    if (status != PSA_SUCCESS) {
+        psa_fail_key_creation(slot, driver);
+    }
+
+    return status;
+}
+
+psa_status_t psa_key_derivation_output_key_ext(
+    const psa_key_attributes_t *attributes,
+    psa_key_derivation_operation_t *operation,
+    const psa_key_production_parameters_t *params,
+    size_t params_data_length,
+    mbedtls_svc_key_id_t *key)
+{
+    return psa_key_derivation_output_key_custom(
+        attributes, operation,
+        (const psa_custom_key_parameters_t *) params,
+        params->data, params_data_length,
+        key);
+}
+
+psa_status_t psa_key_derivation_output_key(
+    const psa_key_attributes_t *attributes,
+    psa_key_derivation_operation_t *operation,
+    mbedtls_svc_key_id_t *key)
+{
+    return psa_key_derivation_output_key_custom(attributes, operation,
+                                                &default_custom_production,
+                                                NULL, 0,
+                                                key);
+}
+
+
+/****************************************************************/
+/* Key derivation */
+/****************************************************************/
+
+#if defined(AT_LEAST_ONE_BUILTIN_KDF)
+static int is_kdf_alg_supported(psa_algorithm_t kdf_alg)
+{
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF)
+    if (PSA_ALG_IS_HKDF(kdf_alg)) {
+        return 1;
+    }
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT)
+    if (PSA_ALG_IS_HKDF_EXTRACT(kdf_alg)) {
+        return 1;
+    }
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND)
+    if (PSA_ALG_IS_HKDF_EXPAND(kdf_alg)) {
+        return 1;
+    }
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF)
+    if (PSA_ALG_IS_TLS12_PRF(kdf_alg)) {
+        return 1;
+    }
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
+    if (PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg)) {
+        return 1;
+    }
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS)
+    if (kdf_alg == PSA_ALG_TLS12_ECJPAKE_TO_PMS) {
+        return 1;
+    }
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_PBKDF2_HMAC)
+    if (PSA_ALG_IS_PBKDF2_HMAC(kdf_alg)) {
+        return 1;
+    }
+#endif
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_PBKDF2_AES_CMAC_PRF_128)
+    if (kdf_alg == PSA_ALG_PBKDF2_AES_CMAC_PRF_128) {
+        return 1;
+    }
+#endif
+    return 0;
+}
+
+static psa_status_t psa_hash_try_support(psa_algorithm_t alg)
+{
+    psa_hash_operation_t operation = PSA_HASH_OPERATION_INIT;
+    psa_status_t status = psa_hash_setup(&operation, alg);
+    psa_hash_abort(&operation);
+    return status;
+}
+
+static psa_status_t psa_key_derivation_set_maximum_capacity(
+    psa_key_derivation_operation_t *operation,
+    psa_algorithm_t kdf_alg)
+{
+#if defined(PSA_WANT_ALG_TLS12_ECJPAKE_TO_PMS)
+    if (kdf_alg == PSA_ALG_TLS12_ECJPAKE_TO_PMS) {
+        operation->capacity = PSA_HASH_LENGTH(PSA_ALG_SHA_256);
+        return PSA_SUCCESS;
+    }
+#endif
+#if defined(PSA_WANT_ALG_PBKDF2_AES_CMAC_PRF_128)
+    if (kdf_alg == PSA_ALG_PBKDF2_AES_CMAC_PRF_128) {
+#if (SIZE_MAX > UINT32_MAX)
+        operation->capacity = UINT32_MAX * (size_t) PSA_MAC_LENGTH(
+            PSA_KEY_TYPE_AES,
+            128U,
+            PSA_ALG_CMAC);
+#else
+        operation->capacity = SIZE_MAX;
+#endif
+        return PSA_SUCCESS;
+    }
+#endif /* PSA_WANT_ALG_PBKDF2_AES_CMAC_PRF_128 */
+
+    /* After this point, if kdf_alg is not valid then value of hash_alg may be
+     * invalid or meaningless but it does not affect this function */
+    psa_algorithm_t hash_alg = PSA_ALG_GET_HASH(kdf_alg);
+    size_t hash_size = PSA_HASH_LENGTH(hash_alg);
+    if (hash_size == 0) {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    /* Make sure that hash_alg is a supported hash algorithm. Otherwise
+     * we might fail later, which is somewhat unfriendly and potentially
+     * risk-prone. */
+    psa_status_t status = psa_hash_try_support(hash_alg);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+#if defined(PSA_WANT_ALG_HKDF)
+    if (PSA_ALG_IS_HKDF(kdf_alg)) {
+        operation->capacity = 255 * hash_size;
+    } else
+#endif
+#if defined(PSA_WANT_ALG_HKDF_EXTRACT)
+    if (PSA_ALG_IS_HKDF_EXTRACT(kdf_alg)) {
+        operation->capacity = hash_size;
+    } else
+#endif
+#if defined(PSA_WANT_ALG_HKDF_EXPAND)
+    if (PSA_ALG_IS_HKDF_EXPAND(kdf_alg)) {
+        operation->capacity = 255 * hash_size;
+    } else
+#endif
+#if defined(PSA_WANT_ALG_TLS12_PRF)
+    if (PSA_ALG_IS_TLS12_PRF(kdf_alg) &&
+        (hash_alg == PSA_ALG_SHA_256 || hash_alg == PSA_ALG_SHA_384)) {
+        operation->capacity = SIZE_MAX;
+    } else
+#endif
+#if defined(PSA_WANT_ALG_TLS12_PSK_TO_MS)
+    if (PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg) &&
+        (hash_alg == PSA_ALG_SHA_256 || hash_alg == PSA_ALG_SHA_384)) {
+        /* Master Secret is always 48 bytes
+         * https://datatracker.ietf.org/doc/html/rfc5246.html#section-8.1 */
+        operation->capacity = 48U;
+    } else
+#endif
+#if defined(PSA_WANT_ALG_PBKDF2_HMAC)
+    if (PSA_ALG_IS_PBKDF2_HMAC(kdf_alg)) {
+#if (SIZE_MAX > UINT32_MAX)
+        operation->capacity = UINT32_MAX * hash_size;
+#else
+        operation->capacity = SIZE_MAX;
+#endif
+    } else
+#endif /* PSA_WANT_ALG_PBKDF2_HMAC */
+    {
+        (void) hash_size;
+        status = PSA_ERROR_NOT_SUPPORTED;
+    }
+    return status;
+}
+
+static psa_status_t psa_key_derivation_setup_kdf(
+    psa_key_derivation_operation_t *operation,
+    psa_algorithm_t kdf_alg)
+{
+    /* Make sure that operation->ctx is properly zero-initialised. (Macro
+     * initialisers for this union leave some bytes unspecified.) */
+    memset(&operation->ctx, 0, sizeof(operation->ctx));
+
+    /* Make sure that kdf_alg is a supported key derivation algorithm. */
+    if (!is_kdf_alg_supported(kdf_alg)) {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    psa_status_t status = psa_key_derivation_set_maximum_capacity(operation,
+                                                                  kdf_alg);
+    return status;
+}
+
+static psa_status_t psa_key_agreement_try_support(psa_algorithm_t alg)
+{
+#if defined(PSA_WANT_ALG_ECDH)
+    if (alg == PSA_ALG_ECDH) {
+        return PSA_SUCCESS;
+    }
+#endif
+#if defined(PSA_WANT_ALG_FFDH)
+    if (alg == PSA_ALG_FFDH) {
+        return PSA_SUCCESS;
+    }
+#endif
+    (void) alg;
+    return PSA_ERROR_NOT_SUPPORTED;
+}
+
+static int psa_key_derivation_allows_free_form_secret_input(
+    psa_algorithm_t kdf_alg)
+{
+#if defined(PSA_WANT_ALG_TLS12_ECJPAKE_TO_PMS)
+    if (kdf_alg == PSA_ALG_TLS12_ECJPAKE_TO_PMS) {
+        return 0;
+    }
+#endif
+    (void) kdf_alg;
+    return 1;
+}
+#endif /* AT_LEAST_ONE_BUILTIN_KDF */
+
+psa_status_t psa_key_derivation_setup(psa_key_derivation_operation_t *operation,
+                                      psa_algorithm_t alg)
+{
+    psa_status_t status;
+
+    if (operation->alg != 0) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (PSA_ALG_IS_RAW_KEY_AGREEMENT(alg)) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    } else if (PSA_ALG_IS_KEY_AGREEMENT(alg)) {
+#if defined(AT_LEAST_ONE_BUILTIN_KDF)
+        psa_algorithm_t kdf_alg = PSA_ALG_KEY_AGREEMENT_GET_KDF(alg);
+        psa_algorithm_t ka_alg = PSA_ALG_KEY_AGREEMENT_GET_BASE(alg);
+        status = psa_key_agreement_try_support(ka_alg);
+        if (status != PSA_SUCCESS) {
+            return status;
+        }
+        if (!psa_key_derivation_allows_free_form_secret_input(kdf_alg)) {
+            return PSA_ERROR_INVALID_ARGUMENT;
+        }
+        status = psa_key_derivation_setup_kdf(operation, kdf_alg);
+#else
+        return PSA_ERROR_NOT_SUPPORTED;
+#endif /* AT_LEAST_ONE_BUILTIN_KDF */
+    } else if (PSA_ALG_IS_KEY_DERIVATION(alg)) {
+#if defined(AT_LEAST_ONE_BUILTIN_KDF)
+        status = psa_key_derivation_setup_kdf(operation, alg);
+#else
+        return PSA_ERROR_NOT_SUPPORTED;
+#endif /* AT_LEAST_ONE_BUILTIN_KDF */
+    } else {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    if (status == PSA_SUCCESS) {
+        operation->alg = alg;
+    }
+    return status;
+}
+
+#if defined(BUILTIN_ALG_ANY_HKDF)
+static psa_status_t psa_hkdf_input(psa_hkdf_key_derivation_t *hkdf,
+                                   psa_algorithm_t kdf_alg,
+                                   psa_key_derivation_step_t step,
+                                   const uint8_t *data,
+                                   size_t data_length)
+{
+    psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH(kdf_alg);
+    psa_status_t status;
+    switch (step) {
+        case PSA_KEY_DERIVATION_INPUT_SALT:
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND)
+            if (PSA_ALG_IS_HKDF_EXPAND(kdf_alg)) {
+                return PSA_ERROR_INVALID_ARGUMENT;
+            }
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND */
+            if (hkdf->state != HKDF_STATE_INIT) {
+                return PSA_ERROR_BAD_STATE;
+            } else {
+                status = psa_key_derivation_start_hmac(&hkdf->hmac,
+                                                       hash_alg,
+                                                       data, data_length);
+                if (status != PSA_SUCCESS) {
+                    return status;
+                }
+                hkdf->state = HKDF_STATE_STARTED;
+                return PSA_SUCCESS;
+            }
+        case PSA_KEY_DERIVATION_INPUT_SECRET:
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND)
+            if (PSA_ALG_IS_HKDF_EXPAND(kdf_alg)) {
+                /* We shouldn't be in different state as HKDF_EXPAND only allows
+                 * two inputs: SECRET (this case) and INFO which does not modify
+                 * the state. It could happen only if the hkdf
+                 * object was corrupted. */
+                if (hkdf->state != HKDF_STATE_INIT) {
+                    return PSA_ERROR_BAD_STATE;
+                }
+
+                /* Allow only input that fits expected prk size */
+                if (data_length != PSA_HASH_LENGTH(hash_alg)) {
+                    return PSA_ERROR_INVALID_ARGUMENT;
+                }
+
+                memcpy(hkdf->prk, data, data_length);
+            } else
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND */
+            {
+                /* HKDF: If no salt was provided, use an empty salt.
+                 * HKDF-EXTRACT: salt is mandatory. */
+                if (hkdf->state == HKDF_STATE_INIT) {
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT)
+                    if (PSA_ALG_IS_HKDF_EXTRACT(kdf_alg)) {
+                        return PSA_ERROR_BAD_STATE;
+                    }
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT */
+                    status = psa_key_derivation_start_hmac(&hkdf->hmac,
+                                                           hash_alg,
+                                                           NULL, 0);
+                    if (status != PSA_SUCCESS) {
+                        return status;
+                    }
+                    hkdf->state = HKDF_STATE_STARTED;
+                }
+                if (hkdf->state != HKDF_STATE_STARTED) {
+                    return PSA_ERROR_BAD_STATE;
+                }
+                status = psa_mac_update(&hkdf->hmac,
+                                        data, data_length);
+                if (status != PSA_SUCCESS) {
+                    return status;
+                }
+                status = psa_mac_sign_finish(&hkdf->hmac,
+                                             hkdf->prk,
+                                             sizeof(hkdf->prk),
+                                             &data_length);
+                if (status != PSA_SUCCESS) {
+                    return status;
+                }
+            }
+
+            hkdf->state = HKDF_STATE_KEYED;
+            hkdf->block_number = 0;
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT)
+            if (PSA_ALG_IS_HKDF_EXTRACT(kdf_alg)) {
+                /* The only block of output is the PRK. */
+                memcpy(hkdf->output_block, hkdf->prk, PSA_HASH_LENGTH(hash_alg));
+                hkdf->offset_in_block = 0;
+            } else
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT */
+            {
+                /* Block 0 is empty, and the next block will be
+                 * generated by psa_key_derivation_hkdf_read(). */
+                hkdf->offset_in_block = PSA_HASH_LENGTH(hash_alg);
+            }
+
+            return PSA_SUCCESS;
+        case PSA_KEY_DERIVATION_INPUT_INFO:
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT)
+            if (PSA_ALG_IS_HKDF_EXTRACT(kdf_alg)) {
+                return PSA_ERROR_INVALID_ARGUMENT;
+            }
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT */
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND)
+            if (PSA_ALG_IS_HKDF_EXPAND(kdf_alg) &&
+                hkdf->state == HKDF_STATE_INIT) {
+                return PSA_ERROR_BAD_STATE;
+            }
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT */
+            if (hkdf->state == HKDF_STATE_OUTPUT) {
+                return PSA_ERROR_BAD_STATE;
+            }
+            if (hkdf->info_set) {
+                return PSA_ERROR_BAD_STATE;
+            }
+            hkdf->info_length = data_length;
+            if (data_length != 0) {
+                hkdf->info = mbedtls_calloc(1, data_length);
+                if (hkdf->info == NULL) {
+                    return PSA_ERROR_INSUFFICIENT_MEMORY;
+                }
+                memcpy(hkdf->info, data, data_length);
+            }
+            hkdf->info_set = 1;
+            return PSA_SUCCESS;
+        default:
+            return PSA_ERROR_INVALID_ARGUMENT;
+    }
+}
+#endif /* BUILTIN_ALG_ANY_HKDF */
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
+static psa_status_t psa_tls12_prf_set_seed(psa_tls12_prf_key_derivation_t *prf,
+                                           const uint8_t *data,
+                                           size_t data_length)
+{
+    if (prf->state != PSA_TLS12_PRF_STATE_INIT) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (data_length != 0) {
+        prf->seed = mbedtls_calloc(1, data_length);
+        if (prf->seed == NULL) {
+            return PSA_ERROR_INSUFFICIENT_MEMORY;
+        }
+
+        memcpy(prf->seed, data, data_length);
+        prf->seed_length = data_length;
+    }
+
+    prf->state = PSA_TLS12_PRF_STATE_SEED_SET;
+
+    return PSA_SUCCESS;
+}
+
+static psa_status_t psa_tls12_prf_set_key(psa_tls12_prf_key_derivation_t *prf,
+                                          const uint8_t *data,
+                                          size_t data_length)
+{
+    if (prf->state != PSA_TLS12_PRF_STATE_SEED_SET &&
+        prf->state != PSA_TLS12_PRF_STATE_OTHER_KEY_SET) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (data_length != 0) {
+        prf->secret = mbedtls_calloc(1, data_length);
+        if (prf->secret == NULL) {
+            return PSA_ERROR_INSUFFICIENT_MEMORY;
+        }
+
+        memcpy(prf->secret, data, data_length);
+        prf->secret_length = data_length;
+    }
+
+    prf->state = PSA_TLS12_PRF_STATE_KEY_SET;
+
+    return PSA_SUCCESS;
+}
+
+static psa_status_t psa_tls12_prf_set_label(psa_tls12_prf_key_derivation_t *prf,
+                                            const uint8_t *data,
+                                            size_t data_length)
+{
+    if (prf->state != PSA_TLS12_PRF_STATE_KEY_SET) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (data_length != 0) {
+        prf->label = mbedtls_calloc(1, data_length);
+        if (prf->label == NULL) {
+            return PSA_ERROR_INSUFFICIENT_MEMORY;
+        }
+
+        memcpy(prf->label, data, data_length);
+        prf->label_length = data_length;
+    }
+
+    prf->state = PSA_TLS12_PRF_STATE_LABEL_SET;
+
+    return PSA_SUCCESS;
+}
+
+static psa_status_t psa_tls12_prf_input(psa_tls12_prf_key_derivation_t *prf,
+                                        psa_key_derivation_step_t step,
+                                        const uint8_t *data,
+                                        size_t data_length)
+{
+    switch (step) {
+        case PSA_KEY_DERIVATION_INPUT_SEED:
+            return psa_tls12_prf_set_seed(prf, data, data_length);
+        case PSA_KEY_DERIVATION_INPUT_SECRET:
+            return psa_tls12_prf_set_key(prf, data, data_length);
+        case PSA_KEY_DERIVATION_INPUT_LABEL:
+            return psa_tls12_prf_set_label(prf, data, data_length);
+        default:
+            return PSA_ERROR_INVALID_ARGUMENT;
+    }
+}
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) ||
+        * MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
+static psa_status_t psa_tls12_prf_psk_to_ms_set_key(
+    psa_tls12_prf_key_derivation_t *prf,
+    const uint8_t *data,
+    size_t data_length)
+{
+    psa_status_t status;
+    const size_t pms_len = (prf->state == PSA_TLS12_PRF_STATE_OTHER_KEY_SET ?
+                            4 + data_length + prf->other_secret_length :
+                            4 + 2 * data_length);
+
+    if (data_length > PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    uint8_t *pms = mbedtls_calloc(1, pms_len);
+    if (pms == NULL) {
+        return PSA_ERROR_INSUFFICIENT_MEMORY;
+    }
+    uint8_t *cur = pms;
+
+    /* pure-PSK:
+     * Quoting RFC 4279, Section 2:
+     *
+     * The premaster secret is formed as follows: if the PSK is N octets
+     * long, concatenate a uint16 with the value N, N zero octets, a second
+     * uint16 with the value N, and the PSK itself.
+     *
+     * mixed-PSK:
+     * In a DHE-PSK, RSA-PSK, ECDHE-PSK the premaster secret is formed as
+     * follows: concatenate a uint16 with the length of the other secret,
+     * the other secret itself, uint16 with the length of PSK, and the
+     * PSK itself.
+     * For details please check:
+     * - RFC 4279, Section 4 for the definition of RSA-PSK,
+     * - RFC 4279, Section 3 for the definition of DHE-PSK,
+     * - RFC 5489 for the definition of ECDHE-PSK.
+     */
+
+    if (prf->state == PSA_TLS12_PRF_STATE_OTHER_KEY_SET) {
+        *cur++ = MBEDTLS_BYTE_1(prf->other_secret_length);
+        *cur++ = MBEDTLS_BYTE_0(prf->other_secret_length);
+        if (prf->other_secret_length != 0) {
+            memcpy(cur, prf->other_secret, prf->other_secret_length);
+            mbedtls_platform_zeroize(prf->other_secret, prf->other_secret_length);
+            cur += prf->other_secret_length;
+        }
+    } else {
+        *cur++ = MBEDTLS_BYTE_1(data_length);
+        *cur++ = MBEDTLS_BYTE_0(data_length);
+        memset(cur, 0, data_length);
+        cur += data_length;
+    }
+
+    *cur++ = MBEDTLS_BYTE_1(data_length);
+    *cur++ = MBEDTLS_BYTE_0(data_length);
+    memcpy(cur, data, data_length);
+    cur += data_length;
+
+    status = psa_tls12_prf_set_key(prf, pms, (size_t) (cur - pms));
+
+    mbedtls_zeroize_and_free(pms, pms_len);
+    return status;
+}
+
+static psa_status_t psa_tls12_prf_psk_to_ms_set_other_key(
+    psa_tls12_prf_key_derivation_t *prf,
+    const uint8_t *data,
+    size_t data_length)
+{
+    if (prf->state != PSA_TLS12_PRF_STATE_SEED_SET) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (data_length != 0) {
+        prf->other_secret = mbedtls_calloc(1, data_length);
+        if (prf->other_secret == NULL) {
+            return PSA_ERROR_INSUFFICIENT_MEMORY;
+        }
+
+        memcpy(prf->other_secret, data, data_length);
+        prf->other_secret_length = data_length;
+    } else {
+        prf->other_secret_length = 0;
+    }
+
+    prf->state = PSA_TLS12_PRF_STATE_OTHER_KEY_SET;
+
+    return PSA_SUCCESS;
+}
+
+static psa_status_t psa_tls12_prf_psk_to_ms_input(
+    psa_tls12_prf_key_derivation_t *prf,
+    psa_key_derivation_step_t step,
+    const uint8_t *data,
+    size_t data_length)
+{
+    switch (step) {
+        case PSA_KEY_DERIVATION_INPUT_SECRET:
+            return psa_tls12_prf_psk_to_ms_set_key(prf,
+                                                   data, data_length);
+            break;
+        case PSA_KEY_DERIVATION_INPUT_OTHER_SECRET:
+            return psa_tls12_prf_psk_to_ms_set_other_key(prf,
+                                                         data,
+                                                         data_length);
+            break;
+        default:
+            return psa_tls12_prf_input(prf, step, data, data_length);
+            break;
+
+    }
+}
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS)
+static psa_status_t psa_tls12_ecjpake_to_pms_input(
+    psa_tls12_ecjpake_to_pms_t *ecjpake,
+    psa_key_derivation_step_t step,
+    const uint8_t *data,
+    size_t data_length)
+{
+    if (data_length != PSA_TLS12_ECJPAKE_TO_PMS_INPUT_SIZE ||
+        step != PSA_KEY_DERIVATION_INPUT_SECRET) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    /* Check if the passed point is in an uncompressed form */
+    if (data[0] != 0x04) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    /* Only K.X has to be extracted - bytes 1 to 32 inclusive. */
+    memcpy(ecjpake->data, data + 1, PSA_TLS12_ECJPAKE_TO_PMS_DATA_SIZE);
+
+    return PSA_SUCCESS;
+}
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS */
+
+#if defined(PSA_HAVE_SOFT_PBKDF2)
+static psa_status_t psa_pbkdf2_set_input_cost(
+    psa_pbkdf2_key_derivation_t *pbkdf2,
+    psa_key_derivation_step_t step,
+    uint64_t data)
+{
+    if (step != PSA_KEY_DERIVATION_INPUT_COST) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    if (pbkdf2->state != PSA_PBKDF2_STATE_INIT) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (data > PSA_VENDOR_PBKDF2_MAX_ITERATIONS) {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    if (data == 0) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    pbkdf2->input_cost = data;
+    pbkdf2->state = PSA_PBKDF2_STATE_INPUT_COST_SET;
+
+    return PSA_SUCCESS;
+}
+
+static psa_status_t psa_pbkdf2_set_salt(psa_pbkdf2_key_derivation_t *pbkdf2,
+                                        const uint8_t *data,
+                                        size_t data_length)
+{
+    if (pbkdf2->state == PSA_PBKDF2_STATE_INPUT_COST_SET) {
+        pbkdf2->state = PSA_PBKDF2_STATE_SALT_SET;
+    } else if (pbkdf2->state == PSA_PBKDF2_STATE_SALT_SET) {
+        /* Appending to existing salt. No state change. */
+    } else {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (data_length == 0) {
+        /* Appending an empty string, nothing to do. */
+    } else {
+        uint8_t *next_salt;
+
+        next_salt = mbedtls_calloc(1, data_length + pbkdf2->salt_length);
+        if (next_salt == NULL) {
+            return PSA_ERROR_INSUFFICIENT_MEMORY;
+        }
+
+        if (pbkdf2->salt_length != 0) {
+            memcpy(next_salt, pbkdf2->salt, pbkdf2->salt_length);
+        }
+        memcpy(next_salt + pbkdf2->salt_length, data, data_length);
+        pbkdf2->salt_length += data_length;
+        mbedtls_free(pbkdf2->salt);
+        pbkdf2->salt = next_salt;
+    }
+    return PSA_SUCCESS;
+}
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_PBKDF2_HMAC)
+static psa_status_t psa_pbkdf2_hmac_set_password(psa_algorithm_t hash_alg,
+                                                 const uint8_t *input,
+                                                 size_t input_len,
+                                                 uint8_t *output,
+                                                 size_t *output_len)
+{
+    psa_status_t status = PSA_SUCCESS;
+    if (input_len > PSA_HASH_BLOCK_LENGTH(hash_alg)) {
+        return psa_hash_compute(hash_alg, input, input_len, output,
+                                PSA_HMAC_MAX_HASH_BLOCK_SIZE, output_len);
+    } else if (input_len > 0) {
+        memcpy(output, input, input_len);
+    }
+    *output_len = PSA_HASH_BLOCK_LENGTH(hash_alg);
+    return status;
+}
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_PBKDF2_HMAC */
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_PBKDF2_AES_CMAC_PRF_128)
+static psa_status_t psa_pbkdf2_cmac_set_password(const uint8_t *input,
+                                                 size_t input_len,
+                                                 uint8_t *output,
+                                                 size_t *output_len)
+{
+    psa_status_t status = PSA_SUCCESS;
+    if (input_len != PSA_MAC_LENGTH(PSA_KEY_TYPE_AES, 128U, PSA_ALG_CMAC)) {
+        psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
+        uint8_t zeros[16] = { 0 };
+        psa_set_key_type(&attributes, PSA_KEY_TYPE_AES);
+        psa_set_key_bits(&attributes, PSA_BYTES_TO_BITS(sizeof(zeros)));
+        psa_set_key_usage_flags(&attributes, PSA_KEY_USAGE_SIGN_MESSAGE);
+        /* Passing PSA_MAC_LENGTH(PSA_KEY_TYPE_AES, 128U, PSA_ALG_CMAC) as
+         * mac_size as the driver function sets mac_output_length = mac_size
+         * on success. See https://github.com/Mbed-TLS/mbedtls/issues/7801 */
+        status = psa_driver_wrapper_mac_compute(&attributes,
+                                                zeros, sizeof(zeros),
+                                                PSA_ALG_CMAC, input, input_len,
+                                                output,
+                                                PSA_MAC_LENGTH(PSA_KEY_TYPE_AES,
+                                                               128U,
+                                                               PSA_ALG_CMAC),
+                                                output_len);
+    } else {
+        memcpy(output, input, input_len);
+        *output_len = PSA_MAC_LENGTH(PSA_KEY_TYPE_AES, 128U, PSA_ALG_CMAC);
+    }
+    return status;
+}
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_PBKDF2_AES_CMAC_PRF_128 */
+
+static psa_status_t psa_pbkdf2_set_password(psa_pbkdf2_key_derivation_t *pbkdf2,
+                                            psa_algorithm_t kdf_alg,
+                                            const uint8_t *data,
+                                            size_t data_length)
+{
+    psa_status_t status = PSA_SUCCESS;
+    if (pbkdf2->state != PSA_PBKDF2_STATE_SALT_SET) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_PBKDF2_HMAC)
+    if (PSA_ALG_IS_PBKDF2_HMAC(kdf_alg)) {
+        psa_algorithm_t hash_alg = PSA_ALG_PBKDF2_HMAC_GET_HASH(kdf_alg);
+        status = psa_pbkdf2_hmac_set_password(hash_alg, data, data_length,
+                                              pbkdf2->password,
+                                              &pbkdf2->password_length);
+    } else
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_PBKDF2_HMAC */
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_PBKDF2_AES_CMAC_PRF_128)
+    if (kdf_alg == PSA_ALG_PBKDF2_AES_CMAC_PRF_128) {
+        status = psa_pbkdf2_cmac_set_password(data, data_length,
+                                              pbkdf2->password,
+                                              &pbkdf2->password_length);
+    } else
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_PBKDF2_AES_CMAC_PRF_128 */
+    {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    pbkdf2->state = PSA_PBKDF2_STATE_PASSWORD_SET;
+
+    return status;
+}
+
+static psa_status_t psa_pbkdf2_input(psa_pbkdf2_key_derivation_t *pbkdf2,
+                                     psa_algorithm_t kdf_alg,
+                                     psa_key_derivation_step_t step,
+                                     const uint8_t *data,
+                                     size_t data_length)
+{
+    switch (step) {
+        case PSA_KEY_DERIVATION_INPUT_SALT:
+            return psa_pbkdf2_set_salt(pbkdf2, data, data_length);
+        case PSA_KEY_DERIVATION_INPUT_PASSWORD:
+            return psa_pbkdf2_set_password(pbkdf2, kdf_alg, data, data_length);
+        default:
+            return PSA_ERROR_INVALID_ARGUMENT;
+    }
+}
+#endif /* PSA_HAVE_SOFT_PBKDF2 */
+
+/** Check whether the given key type is acceptable for the given
+ * input step of a key derivation.
+ *
+ * Secret inputs must have the type #PSA_KEY_TYPE_DERIVE.
+ * Non-secret inputs must have the type #PSA_KEY_TYPE_RAW_DATA.
+ * Both secret and non-secret inputs can alternatively have the type
+ * #PSA_KEY_TYPE_NONE, which is never the type of a key object, meaning
+ * that the input was passed as a buffer rather than via a key object.
+ */
+static int psa_key_derivation_check_input_type(
+    psa_key_derivation_step_t step,
+    psa_key_type_t key_type)
+{
+    switch (step) {
+        case PSA_KEY_DERIVATION_INPUT_SECRET:
+            if (key_type == PSA_KEY_TYPE_DERIVE) {
+                return PSA_SUCCESS;
+            }
+            if (key_type == PSA_KEY_TYPE_NONE) {
+                return PSA_SUCCESS;
+            }
+            break;
+        case PSA_KEY_DERIVATION_INPUT_OTHER_SECRET:
+            if (key_type == PSA_KEY_TYPE_DERIVE) {
+                return PSA_SUCCESS;
+            }
+            if (key_type == PSA_KEY_TYPE_NONE) {
+                return PSA_SUCCESS;
+            }
+            break;
+        case PSA_KEY_DERIVATION_INPUT_LABEL:
+        case PSA_KEY_DERIVATION_INPUT_SALT:
+        case PSA_KEY_DERIVATION_INPUT_INFO:
+        case PSA_KEY_DERIVATION_INPUT_SEED:
+            if (key_type == PSA_KEY_TYPE_RAW_DATA) {
+                return PSA_SUCCESS;
+            }
+            if (key_type == PSA_KEY_TYPE_NONE) {
+                return PSA_SUCCESS;
+            }
+            break;
+        case PSA_KEY_DERIVATION_INPUT_PASSWORD:
+            if (key_type == PSA_KEY_TYPE_PASSWORD) {
+                return PSA_SUCCESS;
+            }
+            if (key_type == PSA_KEY_TYPE_DERIVE) {
+                return PSA_SUCCESS;
+            }
+            if (key_type == PSA_KEY_TYPE_NONE) {
+                return PSA_SUCCESS;
+            }
+            break;
+    }
+    return PSA_ERROR_INVALID_ARGUMENT;
+}
+
+static psa_status_t psa_key_derivation_input_internal(
+    psa_key_derivation_operation_t *operation,
+    psa_key_derivation_step_t step,
+    psa_key_type_t key_type,
+    const uint8_t *data,
+    size_t data_length)
+{
+    psa_status_t status;
+    psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg(operation);
+
+    status = psa_key_derivation_check_input_type(step, key_type);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+#if defined(BUILTIN_ALG_ANY_HKDF)
+    if (PSA_ALG_IS_ANY_HKDF(kdf_alg)) {
+        status = psa_hkdf_input(&operation->ctx.hkdf, kdf_alg,
+                                step, data, data_length);
+    } else
+#endif /* BUILTIN_ALG_ANY_HKDF */
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF)
+    if (PSA_ALG_IS_TLS12_PRF(kdf_alg)) {
+        status = psa_tls12_prf_input(&operation->ctx.tls12_prf,
+                                     step, data, data_length);
+    } else
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF */
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
+    if (PSA_ALG_IS_TLS12_PSK_TO_MS(kdf_alg)) {
+        status = psa_tls12_prf_psk_to_ms_input(&operation->ctx.tls12_prf,
+                                               step, data, data_length);
+    } else
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS)
+    if (kdf_alg == PSA_ALG_TLS12_ECJPAKE_TO_PMS) {
+        status = psa_tls12_ecjpake_to_pms_input(
+            &operation->ctx.tls12_ecjpake_to_pms, step, data, data_length);
+    } else
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_ECJPAKE_TO_PMS */
+#if defined(PSA_HAVE_SOFT_PBKDF2)
+    if (PSA_ALG_IS_PBKDF2(kdf_alg)) {
+        status = psa_pbkdf2_input(&operation->ctx.pbkdf2, kdf_alg,
+                                  step, data, data_length);
+    } else
+#endif /* PSA_HAVE_SOFT_PBKDF2 */
+    {
+        /* This can't happen unless the operation object was not initialized */
+        (void) data;
+        (void) data_length;
+        (void) kdf_alg;
+        return PSA_ERROR_BAD_STATE;
+    }
+
+exit:
+    if (status != PSA_SUCCESS) {
+        psa_key_derivation_abort(operation);
+    }
+    return status;
+}
+
+static psa_status_t psa_key_derivation_input_integer_internal(
+    psa_key_derivation_operation_t *operation,
+    psa_key_derivation_step_t step,
+    uint64_t value)
+{
+    psa_status_t status;
+    psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg(operation);
+
+#if defined(PSA_HAVE_SOFT_PBKDF2)
+    if (PSA_ALG_IS_PBKDF2(kdf_alg)) {
+        status = psa_pbkdf2_set_input_cost(
+            &operation->ctx.pbkdf2, step, value);
+    } else
+#endif /* PSA_HAVE_SOFT_PBKDF2 */
+    {
+        (void) step;
+        (void) value;
+        (void) kdf_alg;
+        status = PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    if (status != PSA_SUCCESS) {
+        psa_key_derivation_abort(operation);
+    }
+    return status;
+}
+
+psa_status_t psa_key_derivation_input_bytes(
+    psa_key_derivation_operation_t *operation,
+    psa_key_derivation_step_t step,
+    const uint8_t *data_external,
+    size_t data_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_INPUT_DECLARE(data_external, data);
+
+    LOCAL_INPUT_ALLOC(data_external, data_length, data);
+
+    status = psa_key_derivation_input_internal(operation, step,
+                                               PSA_KEY_TYPE_NONE,
+                                               data, data_length);
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+    LOCAL_INPUT_FREE(data_external, data);
+    return status;
+}
+
+psa_status_t psa_key_derivation_input_integer(
+    psa_key_derivation_operation_t *operation,
+    psa_key_derivation_step_t step,
+    uint64_t value)
+{
+    return psa_key_derivation_input_integer_internal(operation, step, value);
+}
+
+psa_status_t psa_key_derivation_input_key(
+    psa_key_derivation_operation_t *operation,
+    psa_key_derivation_step_t step,
+    mbedtls_svc_key_id_t key)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+
+    status = psa_get_and_lock_transparent_key_slot_with_policy(
+        key, &slot, PSA_KEY_USAGE_DERIVE, operation->alg);
+    if (status != PSA_SUCCESS) {
+        psa_key_derivation_abort(operation);
+        return status;
+    }
+
+    /* Passing a key object as a SECRET or PASSWORD input unlocks the
+     * permission to output to a key object. */
+    if (step == PSA_KEY_DERIVATION_INPUT_SECRET ||
+        step == PSA_KEY_DERIVATION_INPUT_PASSWORD) {
+        operation->can_output_key = 1;
+    }
+
+    status = psa_key_derivation_input_internal(operation,
+                                               step, slot->attr.type,
+                                               slot->key.data,
+                                               slot->key.bytes);
+
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+
+
+/****************************************************************/
+/* Key agreement */
+/****************************************************************/
+
+psa_status_t psa_key_agreement_raw_builtin(const psa_key_attributes_t *attributes,
+                                           const uint8_t *key_buffer,
+                                           size_t key_buffer_size,
+                                           psa_algorithm_t alg,
+                                           const uint8_t *peer_key,
+                                           size_t peer_key_length,
+                                           uint8_t *shared_secret,
+                                           size_t shared_secret_size,
+                                           size_t *shared_secret_length)
+{
+    switch (alg) {
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH)
+        case PSA_ALG_ECDH:
+            return mbedtls_psa_key_agreement_ecdh(attributes, key_buffer,
+                                                  key_buffer_size, alg,
+                                                  peer_key, peer_key_length,
+                                                  shared_secret,
+                                                  shared_secret_size,
+                                                  shared_secret_length);
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_ECDH */
+
+#if defined(MBEDTLS_PSA_BUILTIN_ALG_FFDH)
+        case PSA_ALG_FFDH:
+            return mbedtls_psa_ffdh_key_agreement(attributes,
+                                                  peer_key,
+                                                  peer_key_length,
+                                                  key_buffer,
+                                                  key_buffer_size,
+                                                  shared_secret,
+                                                  shared_secret_size,
+                                                  shared_secret_length);
+#endif /* MBEDTLS_PSA_BUILTIN_ALG_FFDH */
+
+        default:
+            (void) attributes;
+            (void) key_buffer;
+            (void) key_buffer_size;
+            (void) peer_key;
+            (void) peer_key_length;
+            (void) shared_secret;
+            (void) shared_secret_size;
+            (void) shared_secret_length;
+            return PSA_ERROR_NOT_SUPPORTED;
+    }
+}
+
+/** Internal function for raw key agreement
+ *  Calls the driver wrapper which will hand off key agreement task
+ *  to the driver's implementation if a driver is present.
+ *  Fallback specified in the driver wrapper is built-in raw key agreement
+ *  (psa_key_agreement_raw_builtin).
+ */
+static psa_status_t psa_key_agreement_raw_internal(psa_algorithm_t alg,
+                                                   psa_key_slot_t *private_key,
+                                                   const uint8_t *peer_key,
+                                                   size_t peer_key_length,
+                                                   uint8_t *shared_secret,
+                                                   size_t shared_secret_size,
+                                                   size_t *shared_secret_length)
+{
+    if (!PSA_ALG_IS_RAW_KEY_AGREEMENT(alg)) {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    return psa_driver_wrapper_key_agreement(&private_key->attr,
+                                            private_key->key.data,
+                                            private_key->key.bytes, alg,
+                                            peer_key, peer_key_length,
+                                            shared_secret,
+                                            shared_secret_size,
+                                            shared_secret_length);
+}
+
+/* Note that if this function fails, you must call psa_key_derivation_abort()
+ * to potentially free embedded data structures and wipe confidential data.
+ */
+static psa_status_t psa_key_agreement_internal(psa_key_derivation_operation_t *operation,
+                                               psa_key_derivation_step_t step,
+                                               psa_key_slot_t *private_key,
+                                               const uint8_t *peer_key,
+                                               size_t peer_key_length)
+{
+    psa_status_t status;
+    uint8_t shared_secret[PSA_RAW_KEY_AGREEMENT_OUTPUT_MAX_SIZE] = { 0 };
+    size_t shared_secret_length = 0;
+    psa_algorithm_t ka_alg = PSA_ALG_KEY_AGREEMENT_GET_BASE(operation->alg);
+
+    /* Step 1: run the secret agreement algorithm to generate the shared
+     * secret. */
+    status = psa_key_agreement_raw_internal(ka_alg,
+                                            private_key,
+                                            peer_key, peer_key_length,
+                                            shared_secret,
+                                            sizeof(shared_secret),
+                                            &shared_secret_length);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    /* Step 2: set up the key derivation to generate key material from
+     * the shared secret. A shared secret is permitted wherever a key
+     * of type DERIVE is permitted. */
+    status = psa_key_derivation_input_internal(operation, step,
+                                               PSA_KEY_TYPE_DERIVE,
+                                               shared_secret,
+                                               shared_secret_length);
+exit:
+    mbedtls_platform_zeroize(shared_secret, shared_secret_length);
+    return status;
+}
+
+psa_status_t psa_key_derivation_key_agreement(psa_key_derivation_operation_t *operation,
+                                              psa_key_derivation_step_t step,
+                                              mbedtls_svc_key_id_t private_key,
+                                              const uint8_t *peer_key_external,
+                                              size_t peer_key_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot;
+    LOCAL_INPUT_DECLARE(peer_key_external, peer_key);
+
+    if (!PSA_ALG_IS_KEY_AGREEMENT(operation->alg)) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+    status = psa_get_and_lock_transparent_key_slot_with_policy(
+        private_key, &slot, PSA_KEY_USAGE_DERIVE, operation->alg);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    LOCAL_INPUT_ALLOC(peer_key_external, peer_key_length, peer_key);
+    status = psa_key_agreement_internal(operation, step,
+                                        slot,
+                                        peer_key, peer_key_length);
+
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+    if (status != PSA_SUCCESS) {
+        psa_key_derivation_abort(operation);
+    } else {
+        /* If a private key has been added as SECRET, we allow the derived
+         * key material to be used as a key in PSA Crypto. */
+        if (step == PSA_KEY_DERIVATION_INPUT_SECRET) {
+            operation->can_output_key = 1;
+        }
+    }
+
+    unlock_status = psa_unregister_read_under_mutex(slot);
+    LOCAL_INPUT_FREE(peer_key_external, peer_key);
+
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+psa_status_t psa_raw_key_agreement(psa_algorithm_t alg,
+                                   mbedtls_svc_key_id_t private_key,
+                                   const uint8_t *peer_key_external,
+                                   size_t peer_key_length,
+                                   uint8_t *output_external,
+                                   size_t output_size,
+                                   size_t *output_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot = NULL;
+    size_t expected_length;
+    LOCAL_INPUT_DECLARE(peer_key_external, peer_key);
+    LOCAL_OUTPUT_DECLARE(output_external, output);
+    LOCAL_OUTPUT_ALLOC(output_external, output_size, output);
+
+    if (!PSA_ALG_IS_KEY_AGREEMENT(alg)) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+    status = psa_get_and_lock_transparent_key_slot_with_policy(
+        private_key, &slot, PSA_KEY_USAGE_DERIVE, alg);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    /* PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE() is in general an upper bound
+     * for the output size. The PSA specification only guarantees that this
+     * function works if output_size >= PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(...),
+     * but it might be nice to allow smaller buffers if the output fits.
+     * At the time of writing this comment, with only ECDH implemented,
+     * PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE() is exact so the point is moot.
+     * If FFDH is implemented, PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE() can easily
+     * be exact for it as well. */
+    expected_length =
+        PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(slot->attr.type, slot->attr.bits);
+    if (output_size < expected_length) {
+        status = PSA_ERROR_BUFFER_TOO_SMALL;
+        goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(peer_key_external, peer_key_length, peer_key);
+    status = psa_key_agreement_raw_internal(alg, slot,
+                                            peer_key, peer_key_length,
+                                            output, output_size,
+                                            output_length);
+
+exit:
+    /* Check for successful allocation of output,
+     * with an unsuccessful status. */
+    if (output != NULL && status != PSA_SUCCESS) {
+        /* If an error happens and is not handled properly, the output
+         * may be used as a key to protect sensitive data. Arrange for such
+         * a key to be random, which is likely to result in decryption or
+         * verification errors. This is better than filling the buffer with
+         * some constant data such as zeros, which would result in the data
+         * being protected with a reproducible, easily knowable key.
+         */
+        psa_generate_random_internal(output, output_size);
+        *output_length = output_size;
+    }
+
+    if (output == NULL) {
+        /* output allocation failed. */
+        *output_length = 0;
+    }
+
+    unlock_status = psa_unregister_read_under_mutex(slot);
+
+    LOCAL_INPUT_FREE(peer_key_external, peer_key);
+    LOCAL_OUTPUT_FREE(output_external, output);
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+
+/****************************************************************/
+/* Random generation */
+/****************************************************************/
+
+#if defined(MBEDTLS_PSA_INJECT_ENTROPY)
+#include "entropy_poll.h"
+#endif
+
+/** Initialize the PSA random generator.
+ *
+ *  Note: the mbedtls_threading_psa_rngdata_mutex should be held when calling
+ *  this function if mutexes are enabled.
+ */
+static void mbedtls_psa_random_init(mbedtls_psa_random_context_t *rng)
+{
+#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
+    memset(rng, 0, sizeof(*rng));
+#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
+
+    /* Set default configuration if
+     * mbedtls_psa_crypto_configure_entropy_sources() hasn't been called. */
+    if (rng->entropy_init == NULL) {
+        rng->entropy_init = mbedtls_entropy_init;
+    }
+    if (rng->entropy_free == NULL) {
+        rng->entropy_free = mbedtls_entropy_free;
+    }
+
+    rng->entropy_init(&rng->entropy);
+#if defined(MBEDTLS_PSA_INJECT_ENTROPY) && \
+    defined(MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES)
+    /* The PSA entropy injection feature depends on using NV seed as an entropy
+     * source. Add NV seed as an entropy source for PSA entropy injection. */
+    mbedtls_entropy_add_source(&rng->entropy,
+                               mbedtls_nv_seed_poll, NULL,
+                               MBEDTLS_ENTROPY_BLOCK_SIZE,
+                               MBEDTLS_ENTROPY_SOURCE_STRONG);
+#endif
+
+    mbedtls_psa_drbg_init(&rng->drbg);
+#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
+}
+
+/** Deinitialize the PSA random generator.
+ *
+ *  Note: the mbedtls_threading_psa_rngdata_mutex should be held when calling
+ *  this function if mutexes are enabled.
+ */
+static void mbedtls_psa_random_free(mbedtls_psa_random_context_t *rng)
+{
+#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
+    memset(rng, 0, sizeof(*rng));
+#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
+    mbedtls_psa_drbg_free(&rng->drbg);
+    rng->entropy_free(&rng->entropy);
+#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
+}
+
+/** Seed the PSA random generator.
+ */
+static psa_status_t mbedtls_psa_random_seed(mbedtls_psa_random_context_t *rng)
+{
+#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
+    /* Do nothing: the external RNG seeds itself. */
+    (void) rng;
+    return PSA_SUCCESS;
+#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
+    const unsigned char drbg_seed[] = "PSA";
+    int ret = mbedtls_psa_drbg_seed(&rng->drbg, &rng->entropy,
+                                    drbg_seed, sizeof(drbg_seed) - 1);
+    return mbedtls_to_psa_error(ret);
+#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
+}
+
+psa_status_t psa_generate_random(uint8_t *output_external,
+                                 size_t output_size)
+{
+    psa_status_t status;
+
+    LOCAL_OUTPUT_DECLARE(output_external, output);
+    LOCAL_OUTPUT_ALLOC(output_external, output_size, output);
+
+    status = psa_generate_random_internal(output, output_size);
+
+#if !defined(MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS)
+exit:
+#endif
+    LOCAL_OUTPUT_FREE(output_external, output);
+    return status;
+}
+
+#if defined(MBEDTLS_PSA_INJECT_ENTROPY)
+psa_status_t mbedtls_psa_inject_entropy(const uint8_t *seed,
+                                        size_t seed_size)
+{
+    if (psa_get_initialized()) {
+        return PSA_ERROR_NOT_PERMITTED;
+    }
+
+    if (((seed_size < MBEDTLS_ENTROPY_MIN_PLATFORM) ||
+         (seed_size < MBEDTLS_ENTROPY_BLOCK_SIZE)) ||
+        (seed_size > MBEDTLS_ENTROPY_MAX_SEED_SIZE)) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    return mbedtls_psa_storage_inject_entropy(seed, seed_size);
+}
+#endif /* MBEDTLS_PSA_INJECT_ENTROPY */
+
+/** Validate the key type and size for key generation
+ *
+ * \param  type  The key type
+ * \param  bits  The number of bits of the key
+ *
+ * \retval #PSA_SUCCESS
+ *         The key type and size are valid.
+ * \retval #PSA_ERROR_INVALID_ARGUMENT
+ *         The size in bits of the key is not valid.
+ * \retval #PSA_ERROR_NOT_SUPPORTED
+ *         The type and/or the size in bits of the key or the combination of
+ *         the two is not supported.
+ */
+static psa_status_t psa_validate_key_type_and_size_for_key_generation(
+    psa_key_type_t type, size_t bits)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    if (key_type_is_raw_bytes(type)) {
+        status = psa_validate_unstructured_key_bit_size(type, bits);
+        if (status != PSA_SUCCESS) {
+            return status;
+        }
+    } else
+#if defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_GENERATE)
+    if (PSA_KEY_TYPE_IS_RSA(type) && PSA_KEY_TYPE_IS_KEY_PAIR(type)) {
+        if (bits > PSA_VENDOR_RSA_MAX_KEY_BITS) {
+            return PSA_ERROR_NOT_SUPPORTED;
+        }
+        if (bits < PSA_VENDOR_RSA_GENERATE_MIN_KEY_BITS) {
+            return PSA_ERROR_NOT_SUPPORTED;
+        }
+
+        /* Accept only byte-aligned keys, for the same reasons as
+         * in psa_import_rsa_key(). */
+        if (bits % 8 != 0) {
+            return PSA_ERROR_NOT_SUPPORTED;
+        }
+    } else
+#endif /* defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_GENERATE) */
+
+#if defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR_GENERATE)
+    if (PSA_KEY_TYPE_IS_ECC(type) && PSA_KEY_TYPE_IS_KEY_PAIR(type)) {
+        /* To avoid empty block, return successfully here. */
+        return PSA_SUCCESS;
+    } else
+#endif /* defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR_GENERATE) */
+
+#if defined(PSA_WANT_KEY_TYPE_DH_KEY_PAIR_GENERATE)
+    if (PSA_KEY_TYPE_IS_DH(type) && PSA_KEY_TYPE_IS_KEY_PAIR(type)) {
+        if (psa_is_dh_key_size_valid(bits) == 0) {
+            return PSA_ERROR_NOT_SUPPORTED;
+        }
+    } else
+#endif /* defined(PSA_WANT_KEY_TYPE_DH_KEY_PAIR_GENERATE) */
+    {
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_generate_key_internal(
+    const psa_key_attributes_t *attributes,
+    const psa_custom_key_parameters_t *custom,
+    const uint8_t *custom_data,
+    size_t custom_data_length,
+    uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_type_t type = attributes->type;
+
+    /* Only used for RSA */
+    (void) custom;
+    (void) custom_data;
+    (void) custom_data_length;
+
+    if (key_type_is_raw_bytes(type)) {
+        status = psa_generate_random_internal(key_buffer, key_buffer_size);
+        if (status != PSA_SUCCESS) {
+            return status;
+        }
+
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES)
+        if (type == PSA_KEY_TYPE_DES) {
+            psa_des_set_key_parity(key_buffer, key_buffer_size);
+        }
+#endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES */
+    } else
+
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR_GENERATE)
+    if (type == PSA_KEY_TYPE_RSA_KEY_PAIR) {
+        return mbedtls_psa_rsa_generate_key(attributes,
+                                            custom_data, custom_data_length,
+                                            key_buffer,
+                                            key_buffer_size,
+                                            key_buffer_length);
+    } else
+#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR_GENERATE) */
+
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_GENERATE)
+    if (PSA_KEY_TYPE_IS_ECC(type) && PSA_KEY_TYPE_IS_KEY_PAIR(type)) {
+        return mbedtls_psa_ecp_generate_key(attributes,
+                                            key_buffer,
+                                            key_buffer_size,
+                                            key_buffer_length);
+    } else
+#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_GENERATE) */
+
+#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_KEY_PAIR_GENERATE)
+    if (PSA_KEY_TYPE_IS_DH(type) && PSA_KEY_TYPE_IS_KEY_PAIR(type)) {
+        return mbedtls_psa_ffdh_generate_key(attributes,
+                                             key_buffer,
+                                             key_buffer_size,
+                                             key_buffer_length);
+    } else
+#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DH_KEY_PAIR_GENERATE) */
+    {
+        (void) key_buffer_length;
+        return PSA_ERROR_NOT_SUPPORTED;
+    }
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_generate_key_custom(const psa_key_attributes_t *attributes,
+                                     const psa_custom_key_parameters_t *custom,
+                                     const uint8_t *custom_data,
+                                     size_t custom_data_length,
+                                     mbedtls_svc_key_id_t *key)
+{
+    psa_status_t status;
+    psa_key_slot_t *slot = NULL;
+    psa_se_drv_table_entry_t *driver = NULL;
+    size_t key_buffer_size;
+
+    *key = MBEDTLS_SVC_KEY_ID_INIT;
+
+    /* Reject any attempt to create a zero-length key so that we don't
+     * risk tripping up later, e.g. on a malloc(0) that returns NULL. */
+    if (psa_get_key_bits(attributes) == 0) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    /* Reject any attempt to create a public key. */
+    if (PSA_KEY_TYPE_IS_PUBLIC_KEY(attributes->type)) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+#if defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_GENERATE)
+    if (attributes->type == PSA_KEY_TYPE_RSA_KEY_PAIR) {
+        if (custom->flags != 0) {
+            return PSA_ERROR_INVALID_ARGUMENT;
+        }
+    } else
+#endif
+    if (!psa_custom_key_parameters_are_default(custom, custom_data_length)) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    status = psa_start_key_creation(PSA_KEY_CREATION_GENERATE, attributes,
+                                    &slot, &driver);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    /* In the case of a transparent key or an opaque key stored in local
+     * storage ( thus not in the case of generating a key in a secure element
+     * with storage ( MBEDTLS_PSA_CRYPTO_SE_C ) ),we have to allocate a
+     * buffer to hold the generated key material. */
+    if (slot->key.data == NULL) {
+        if (PSA_KEY_LIFETIME_GET_LOCATION(attributes->lifetime) ==
+            PSA_KEY_LOCATION_LOCAL_STORAGE) {
+            status = psa_validate_key_type_and_size_for_key_generation(
+                attributes->type, attributes->bits);
+            if (status != PSA_SUCCESS) {
+                goto exit;
+            }
+
+            key_buffer_size = PSA_EXPORT_KEY_OUTPUT_SIZE(
+                attributes->type,
+                attributes->bits);
+        } else {
+            status = psa_driver_wrapper_get_key_buffer_size(
+                attributes, &key_buffer_size);
+            if (status != PSA_SUCCESS) {
+                goto exit;
+            }
+        }
+
+        status = psa_allocate_buffer_to_slot(slot, key_buffer_size);
+        if (status != PSA_SUCCESS) {
+            goto exit;
+        }
+    }
+
+    status = psa_driver_wrapper_generate_key(attributes,
+                                             custom,
+                                             custom_data, custom_data_length,
+                                             slot->key.data, slot->key.bytes,
+                                             &slot->key.bytes);
+    if (status != PSA_SUCCESS) {
+        psa_remove_key_data_from_memory(slot);
+    }
+
+exit:
+    if (status == PSA_SUCCESS) {
+        status = psa_finish_key_creation(slot, driver, key);
+    }
+    if (status != PSA_SUCCESS) {
+        psa_fail_key_creation(slot, driver);
+    }
+
+    return status;
+}
+
+psa_status_t psa_generate_key_ext(const psa_key_attributes_t *attributes,
+                                  const psa_key_production_parameters_t *params,
+                                  size_t params_data_length,
+                                  mbedtls_svc_key_id_t *key)
+{
+    return psa_generate_key_custom(
+        attributes,
+        (const psa_custom_key_parameters_t *) params,
+        params->data, params_data_length,
+        key);
+}
+
+psa_status_t psa_generate_key(const psa_key_attributes_t *attributes,
+                              mbedtls_svc_key_id_t *key)
+{
+    return psa_generate_key_custom(attributes,
+                                   &default_custom_production,
+                                   NULL, 0,
+                                   key);
+}
+
+/****************************************************************/
+/* Module setup */
+/****************************************************************/
+
+#if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
+psa_status_t mbedtls_psa_crypto_configure_entropy_sources(
+    void (* entropy_init)(mbedtls_entropy_context *ctx),
+    void (* entropy_free)(mbedtls_entropy_context *ctx))
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_lock(&mbedtls_threading_psa_rngdata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+    if (global_data.rng_state != RNG_NOT_INITIALIZED) {
+        status = PSA_ERROR_BAD_STATE;
+    } else {
+        global_data.rng.entropy_init = entropy_init;
+        global_data.rng.entropy_free = entropy_free;
+        status = PSA_SUCCESS;
+    }
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_unlock(&mbedtls_threading_psa_rngdata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+    return status;
+}
+#endif /* !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) */
+
+void mbedtls_psa_crypto_free(void)
+{
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_lock(&mbedtls_threading_psa_globaldata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+    /* Nothing to do to free transaction. */
+    if (global_data.initialized & PSA_CRYPTO_SUBSYSTEM_TRANSACTION_INITIALIZED) {
+        global_data.initialized &= ~PSA_CRYPTO_SUBSYSTEM_TRANSACTION_INITIALIZED;
+    }
+
+    if (global_data.initialized & PSA_CRYPTO_SUBSYSTEM_KEY_SLOTS_INITIALIZED) {
+        psa_wipe_all_key_slots();
+        global_data.initialized &= ~PSA_CRYPTO_SUBSYSTEM_KEY_SLOTS_INITIALIZED;
+    }
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_unlock(&mbedtls_threading_psa_globaldata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_lock(&mbedtls_threading_psa_rngdata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+    if (global_data.rng_state != RNG_NOT_INITIALIZED) {
+        mbedtls_psa_random_free(&global_data.rng);
+    }
+    global_data.rng_state = RNG_NOT_INITIALIZED;
+    mbedtls_platform_zeroize(&global_data.rng, sizeof(global_data.rng));
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_unlock(&mbedtls_threading_psa_rngdata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_lock(&mbedtls_threading_psa_globaldata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+    /* Terminate drivers */
+    if (global_data.initialized & PSA_CRYPTO_SUBSYSTEM_DRIVER_WRAPPERS_INITIALIZED) {
+        psa_driver_wrapper_free();
+        global_data.initialized &= ~PSA_CRYPTO_SUBSYSTEM_DRIVER_WRAPPERS_INITIALIZED;
+    }
+
+#if defined(MBEDTLS_THREADING_C)
+    mbedtls_mutex_unlock(&mbedtls_threading_psa_globaldata_mutex);
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+}
+
+#if defined(PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS)
+/** Recover a transaction that was interrupted by a power failure.
+ *
+ * This function is called during initialization, before psa_crypto_init()
+ * returns. If this function returns a failure status, the initialization
+ * fails.
+ */
+static psa_status_t psa_crypto_recover_transaction(
+    const psa_crypto_transaction_t *transaction)
+{
+    switch (transaction->unknown.type) {
+        case PSA_CRYPTO_TRANSACTION_CREATE_KEY:
+        case PSA_CRYPTO_TRANSACTION_DESTROY_KEY:
+        /* TODO - fall through to the failure case until this
+         * is implemented.
+         * https://github.com/ARMmbed/mbed-crypto/issues/218
+         */
+        default:
+            /* We found an unsupported transaction in the storage.
+             * We don't know what state the storage is in. Give up. */
+            return PSA_ERROR_DATA_INVALID;
+    }
+}
+#endif /* PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS */
+
+static psa_status_t mbedtls_psa_crypto_init_subsystem(mbedtls_psa_crypto_subsystem subsystem)
+{
+    psa_status_t status = PSA_SUCCESS;
+    uint8_t driver_wrappers_initialized = 0;
+
+    switch (subsystem) {
+        case PSA_CRYPTO_SUBSYSTEM_DRIVER_WRAPPERS:
+
+#if defined(MBEDTLS_THREADING_C)
+            PSA_THREADING_CHK_GOTO_EXIT(mbedtls_mutex_lock(&mbedtls_threading_psa_globaldata_mutex));
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+            if (!(global_data.initialized & PSA_CRYPTO_SUBSYSTEM_DRIVER_WRAPPERS_INITIALIZED)) {
+                /* Init drivers */
+                status = psa_driver_wrapper_init();
+
+                /* Drivers need shutdown regardless of startup errors. */
+                global_data.initialized |= PSA_CRYPTO_SUBSYSTEM_DRIVER_WRAPPERS_INITIALIZED;
+
+
+            }
+#if defined(MBEDTLS_THREADING_C)
+            PSA_THREADING_CHK_GOTO_EXIT(mbedtls_mutex_unlock(
+                                            &mbedtls_threading_psa_globaldata_mutex));
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+            break;
+
+        case PSA_CRYPTO_SUBSYSTEM_KEY_SLOTS:
+
+#if defined(MBEDTLS_THREADING_C)
+            PSA_THREADING_CHK_GOTO_EXIT(mbedtls_mutex_lock(&mbedtls_threading_psa_globaldata_mutex));
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+            if (!(global_data.initialized & PSA_CRYPTO_SUBSYSTEM_KEY_SLOTS_INITIALIZED)) {
+                status = psa_initialize_key_slots();
+
+                /* Need to wipe keys even if initialization fails. */
+                global_data.initialized |= PSA_CRYPTO_SUBSYSTEM_KEY_SLOTS_INITIALIZED;
+
+            }
+#if defined(MBEDTLS_THREADING_C)
+            PSA_THREADING_CHK_GOTO_EXIT(mbedtls_mutex_unlock(
+                                            &mbedtls_threading_psa_globaldata_mutex));
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+            break;
+
+        case PSA_CRYPTO_SUBSYSTEM_RNG:
+
+#if defined(MBEDTLS_THREADING_C)
+            PSA_THREADING_CHK_GOTO_EXIT(mbedtls_mutex_lock(&mbedtls_threading_psa_globaldata_mutex));
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+            driver_wrappers_initialized =
+                (global_data.initialized & PSA_CRYPTO_SUBSYSTEM_DRIVER_WRAPPERS_INITIALIZED);
+
+#if defined(MBEDTLS_THREADING_C)
+            PSA_THREADING_CHK_GOTO_EXIT(mbedtls_mutex_unlock(
+                                            &mbedtls_threading_psa_globaldata_mutex));
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+            /* Need to use separate mutex here, as initialisation can require
+             * testing of init flags, which requires locking the global data
+             * mutex. */
+#if defined(MBEDTLS_THREADING_C)
+            PSA_THREADING_CHK_GOTO_EXIT(mbedtls_mutex_lock(&mbedtls_threading_psa_rngdata_mutex));
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+            /* Initialize and seed the random generator. */
+            if (global_data.rng_state == RNG_NOT_INITIALIZED && driver_wrappers_initialized) {
+                mbedtls_psa_random_init(&global_data.rng);
+                global_data.rng_state = RNG_INITIALIZED;
+
+                status = mbedtls_psa_random_seed(&global_data.rng);
+                if (status == PSA_SUCCESS) {
+                    global_data.rng_state = RNG_SEEDED;
+                }
+            }
+
+#if defined(MBEDTLS_THREADING_C)
+            PSA_THREADING_CHK_GOTO_EXIT(mbedtls_mutex_unlock(
+                                            &mbedtls_threading_psa_rngdata_mutex));
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+            break;
+
+        case PSA_CRYPTO_SUBSYSTEM_TRANSACTION:
+
+#if defined(MBEDTLS_THREADING_C)
+            PSA_THREADING_CHK_GOTO_EXIT(mbedtls_mutex_lock(&mbedtls_threading_psa_globaldata_mutex));
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+            if (!(global_data.initialized & PSA_CRYPTO_SUBSYSTEM_TRANSACTION_INITIALIZED)) {
+#if defined(PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS)
+                status = psa_crypto_load_transaction();
+                if (status == PSA_SUCCESS) {
+                    status = psa_crypto_recover_transaction(&psa_crypto_transaction);
+                    if (status == PSA_SUCCESS) {
+                        global_data.initialized |= PSA_CRYPTO_SUBSYSTEM_TRANSACTION_INITIALIZED;
+                    }
+                    status = psa_crypto_stop_transaction();
+                } else if (status == PSA_ERROR_DOES_NOT_EXIST) {
+                    /* There's no transaction to complete. It's all good. */
+                    global_data.initialized |= PSA_CRYPTO_SUBSYSTEM_TRANSACTION_INITIALIZED;
+                    status = PSA_SUCCESS;
+                }
+#else /* defined(PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS) */
+                global_data.initialized |= PSA_CRYPTO_SUBSYSTEM_TRANSACTION_INITIALIZED;
+                status = PSA_SUCCESS;
+#endif /* defined(PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS) */
+            }
+
+#if defined(MBEDTLS_THREADING_C)
+            PSA_THREADING_CHK_GOTO_EXIT(mbedtls_mutex_unlock(
+                                            &mbedtls_threading_psa_globaldata_mutex));
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+            break;
+
+        default:
+            status = PSA_ERROR_CORRUPTION_DETECTED;
+    }
+
+    /* Exit label only required when using threading macros. */
+#if defined(MBEDTLS_THREADING_C)
+exit:
+#endif /* defined(MBEDTLS_THREADING_C) */
+
+    return status;
+}
+
+psa_status_t psa_crypto_init(void)
+{
+    psa_status_t status;
+
+    /* Double initialization is explicitly allowed. Early out if everything is
+     * done. */
+    if (psa_get_initialized()) {
+        return PSA_SUCCESS;
+    }
+
+    status = mbedtls_psa_crypto_init_subsystem(PSA_CRYPTO_SUBSYSTEM_DRIVER_WRAPPERS);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = mbedtls_psa_crypto_init_subsystem(PSA_CRYPTO_SUBSYSTEM_KEY_SLOTS);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = mbedtls_psa_crypto_init_subsystem(PSA_CRYPTO_SUBSYSTEM_RNG);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = mbedtls_psa_crypto_init_subsystem(PSA_CRYPTO_SUBSYSTEM_TRANSACTION);
+
+exit:
+
+    if (status != PSA_SUCCESS) {
+        mbedtls_psa_crypto_free();
+    }
+
+    return status;
+}
+
+#if defined(PSA_WANT_ALG_SOME_PAKE)
+psa_status_t psa_crypto_driver_pake_get_password_len(
+    const psa_crypto_driver_pake_inputs_t *inputs,
+    size_t *password_len)
+{
+    if (inputs->password_len == 0) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    *password_len = inputs->password_len;
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_crypto_driver_pake_get_password(
+    const psa_crypto_driver_pake_inputs_t *inputs,
+    uint8_t *buffer, size_t buffer_size, size_t *buffer_length)
+{
+    if (inputs->password_len == 0) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (buffer_size < inputs->password_len) {
+        return PSA_ERROR_BUFFER_TOO_SMALL;
+    }
+
+    memcpy(buffer, inputs->password, inputs->password_len);
+    *buffer_length = inputs->password_len;
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_crypto_driver_pake_get_user_len(
+    const psa_crypto_driver_pake_inputs_t *inputs,
+    size_t *user_len)
+{
+    if (inputs->user_len == 0) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    *user_len = inputs->user_len;
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_crypto_driver_pake_get_user(
+    const psa_crypto_driver_pake_inputs_t *inputs,
+    uint8_t *user_id, size_t user_id_size, size_t *user_id_len)
+{
+    if (inputs->user_len == 0) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (user_id_size < inputs->user_len) {
+        return PSA_ERROR_BUFFER_TOO_SMALL;
+    }
+
+    memcpy(user_id, inputs->user, inputs->user_len);
+    *user_id_len = inputs->user_len;
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_crypto_driver_pake_get_peer_len(
+    const psa_crypto_driver_pake_inputs_t *inputs,
+    size_t *peer_len)
+{
+    if (inputs->peer_len == 0) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    *peer_len = inputs->peer_len;
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_crypto_driver_pake_get_peer(
+    const psa_crypto_driver_pake_inputs_t *inputs,
+    uint8_t *peer_id, size_t peer_id_size, size_t *peer_id_length)
+{
+    if (inputs->peer_len == 0) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (peer_id_size < inputs->peer_len) {
+        return PSA_ERROR_BUFFER_TOO_SMALL;
+    }
+
+    memcpy(peer_id, inputs->peer, inputs->peer_len);
+    *peer_id_length = inputs->peer_len;
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_crypto_driver_pake_get_cipher_suite(
+    const psa_crypto_driver_pake_inputs_t *inputs,
+    psa_pake_cipher_suite_t *cipher_suite)
+{
+    if (inputs->cipher_suite.algorithm == PSA_ALG_NONE) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    *cipher_suite = inputs->cipher_suite;
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_pake_setup(
+    psa_pake_operation_t *operation,
+    const psa_pake_cipher_suite_t *cipher_suite)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    if (operation->stage != PSA_PAKE_OPERATION_STAGE_SETUP) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (PSA_ALG_IS_PAKE(cipher_suite->algorithm) == 0 ||
+        PSA_ALG_IS_HASH(cipher_suite->hash) == 0) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    memset(&operation->data.inputs, 0, sizeof(operation->data.inputs));
+
+    operation->alg = cipher_suite->algorithm;
+    operation->primitive = PSA_PAKE_PRIMITIVE(cipher_suite->type,
+                                              cipher_suite->family, cipher_suite->bits);
+    operation->data.inputs.cipher_suite = *cipher_suite;
+
+#if defined(PSA_WANT_ALG_JPAKE)
+    if (operation->alg == PSA_ALG_JPAKE) {
+        psa_jpake_computation_stage_t *computation_stage =
+            &operation->computation_stage.jpake;
+
+        memset(computation_stage, 0, sizeof(*computation_stage));
+        computation_stage->step = PSA_PAKE_STEP_KEY_SHARE;
+    } else
+#endif /* PSA_WANT_ALG_JPAKE */
+    {
+        status = PSA_ERROR_NOT_SUPPORTED;
+        goto exit;
+    }
+
+    operation->stage = PSA_PAKE_OPERATION_STAGE_COLLECT_INPUTS;
+
+    return PSA_SUCCESS;
+exit:
+    psa_pake_abort(operation);
+    return status;
+}
+
+psa_status_t psa_pake_set_password_key(
+    psa_pake_operation_t *operation,
+    mbedtls_svc_key_id_t password)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_key_slot_t *slot = NULL;
+    psa_key_type_t type;
+
+    if (operation->stage != PSA_PAKE_OPERATION_STAGE_COLLECT_INPUTS) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    status = psa_get_and_lock_key_slot_with_policy(password, &slot,
+                                                   PSA_KEY_USAGE_DERIVE,
+                                                   operation->alg);
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    type = psa_get_key_type(&slot->attr);
+
+    if (type != PSA_KEY_TYPE_PASSWORD &&
+        type != PSA_KEY_TYPE_PASSWORD_HASH) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    operation->data.inputs.password = mbedtls_calloc(1, slot->key.bytes);
+    if (operation->data.inputs.password == NULL) {
+        status = PSA_ERROR_INSUFFICIENT_MEMORY;
+        goto exit;
+    }
+
+    memcpy(operation->data.inputs.password, slot->key.data, slot->key.bytes);
+    operation->data.inputs.password_len = slot->key.bytes;
+    operation->data.inputs.attributes = slot->attr;
+
+exit:
+    if (status != PSA_SUCCESS) {
+        psa_pake_abort(operation);
+    }
+    unlock_status = psa_unregister_read_under_mutex(slot);
+    return (status == PSA_SUCCESS) ? unlock_status : status;
+}
+
+psa_status_t psa_pake_set_user(
+    psa_pake_operation_t *operation,
+    const uint8_t *user_id_external,
+    size_t user_id_len)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_INPUT_DECLARE(user_id_external, user_id);
+
+    if (operation->stage != PSA_PAKE_OPERATION_STAGE_COLLECT_INPUTS) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (user_id_len == 0) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    if (operation->data.inputs.user_len != 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    operation->data.inputs.user = mbedtls_calloc(1, user_id_len);
+    if (operation->data.inputs.user == NULL) {
+        status = PSA_ERROR_INSUFFICIENT_MEMORY;
+        goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(user_id_external, user_id_len, user_id);
+
+    memcpy(operation->data.inputs.user, user_id, user_id_len);
+    operation->data.inputs.user_len = user_id_len;
+
+    status = PSA_SUCCESS;
+
+exit:
+    LOCAL_INPUT_FREE(user_id_external, user_id);
+    if (status != PSA_SUCCESS) {
+        psa_pake_abort(operation);
+    }
+    return status;
+}
+
+psa_status_t psa_pake_set_peer(
+    psa_pake_operation_t *operation,
+    const uint8_t *peer_id_external,
+    size_t peer_id_len)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    LOCAL_INPUT_DECLARE(peer_id_external, peer_id);
+
+    if (operation->stage != PSA_PAKE_OPERATION_STAGE_COLLECT_INPUTS) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (peer_id_len == 0) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    if (operation->data.inputs.peer_len != 0) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    operation->data.inputs.peer = mbedtls_calloc(1, peer_id_len);
+    if (operation->data.inputs.peer == NULL) {
+        status = PSA_ERROR_INSUFFICIENT_MEMORY;
+        goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(peer_id_external, peer_id_len, peer_id);
+
+    memcpy(operation->data.inputs.peer, peer_id, peer_id_len);
+    operation->data.inputs.peer_len = peer_id_len;
+
+    status = PSA_SUCCESS;
+
+exit:
+    LOCAL_INPUT_FREE(peer_id_external, peer_id);
+    if (status != PSA_SUCCESS) {
+        psa_pake_abort(operation);
+    }
+    return status;
+}
+
+psa_status_t psa_pake_set_role(
+    psa_pake_operation_t *operation,
+    psa_pake_role_t role)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    if (operation->stage != PSA_PAKE_OPERATION_STAGE_COLLECT_INPUTS) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    switch (operation->alg) {
+#if defined(PSA_WANT_ALG_JPAKE)
+        case PSA_ALG_JPAKE:
+            if (role == PSA_PAKE_ROLE_NONE) {
+                return PSA_SUCCESS;
+            }
+            status = PSA_ERROR_INVALID_ARGUMENT;
+            break;
+#endif
+        default:
+            (void) role;
+            status = PSA_ERROR_NOT_SUPPORTED;
+            goto exit;
+    }
+exit:
+    psa_pake_abort(operation);
+    return status;
+}
+
+/* Auxiliary function to convert core computation stage to single driver step. */
+#if defined(PSA_WANT_ALG_JPAKE)
+static psa_crypto_driver_pake_step_t convert_jpake_computation_stage_to_driver_step(
+    psa_jpake_computation_stage_t *stage)
+{
+    psa_crypto_driver_pake_step_t key_share_step;
+    if (stage->round == PSA_JPAKE_FIRST) {
+        int is_x1;
+
+        if (stage->io_mode == PSA_JPAKE_OUTPUT) {
+            is_x1 = (stage->outputs < 1);
+        } else {
+            is_x1 = (stage->inputs < 1);
+        }
+
+        key_share_step = is_x1 ?
+                         PSA_JPAKE_X1_STEP_KEY_SHARE :
+                         PSA_JPAKE_X2_STEP_KEY_SHARE;
+    } else if (stage->round == PSA_JPAKE_SECOND) {
+        key_share_step = (stage->io_mode == PSA_JPAKE_OUTPUT) ?
+                         PSA_JPAKE_X2S_STEP_KEY_SHARE :
+                         PSA_JPAKE_X4S_STEP_KEY_SHARE;
+    } else {
+        return PSA_JPAKE_STEP_INVALID;
+    }
+    return (psa_crypto_driver_pake_step_t) (key_share_step + stage->step - PSA_PAKE_STEP_KEY_SHARE);
+}
+#endif /* PSA_WANT_ALG_JPAKE */
+
+static psa_status_t psa_pake_complete_inputs(
+    psa_pake_operation_t *operation)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    /* Create copy of the inputs on stack as inputs share memory
+       with the driver context which will be setup by the driver. */
+    psa_crypto_driver_pake_inputs_t inputs = operation->data.inputs;
+
+    if (inputs.password_len == 0) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (operation->alg == PSA_ALG_JPAKE) {
+        if (inputs.user_len == 0 || inputs.peer_len == 0) {
+            return PSA_ERROR_BAD_STATE;
+        }
+    }
+
+    /* Clear driver context */
+    mbedtls_platform_zeroize(&operation->data, sizeof(operation->data));
+
+    status = psa_driver_wrapper_pake_setup(operation, &inputs);
+
+    /* Driver is responsible for creating its own copy of the password. */
+    mbedtls_zeroize_and_free(inputs.password, inputs.password_len);
+
+    /* User and peer are translated to role. */
+    mbedtls_free(inputs.user);
+    mbedtls_free(inputs.peer);
+
+    if (status == PSA_SUCCESS) {
+#if defined(PSA_WANT_ALG_JPAKE)
+        if (operation->alg == PSA_ALG_JPAKE) {
+            operation->stage = PSA_PAKE_OPERATION_STAGE_COMPUTATION;
+        } else
+#endif /* PSA_WANT_ALG_JPAKE */
+        {
+            status = PSA_ERROR_NOT_SUPPORTED;
+        }
+    }
+    return status;
+}
+
+#if defined(PSA_WANT_ALG_JPAKE)
+static psa_status_t psa_jpake_prologue(
+    psa_pake_operation_t *operation,
+    psa_pake_step_t step,
+    psa_jpake_io_mode_t io_mode)
+{
+    if (step != PSA_PAKE_STEP_KEY_SHARE &&
+        step != PSA_PAKE_STEP_ZK_PUBLIC &&
+        step != PSA_PAKE_STEP_ZK_PROOF) {
+        return PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    psa_jpake_computation_stage_t *computation_stage =
+        &operation->computation_stage.jpake;
+
+    if (computation_stage->round != PSA_JPAKE_FIRST &&
+        computation_stage->round != PSA_JPAKE_SECOND) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    /* Check that the step we are given is the one we were expecting */
+    if (step != computation_stage->step) {
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    if (step == PSA_PAKE_STEP_KEY_SHARE &&
+        computation_stage->inputs == 0 &&
+        computation_stage->outputs == 0) {
+        /* Start of the round, so function decides whether we are inputting
+         * or outputting */
+        computation_stage->io_mode = io_mode;
+    } else if (computation_stage->io_mode != io_mode) {
+        /* Middle of the round so the mode we are in must match the function
+         * called by the user */
+        return PSA_ERROR_BAD_STATE;
+    }
+
+    return PSA_SUCCESS;
+}
+
+static psa_status_t psa_jpake_epilogue(
+    psa_pake_operation_t *operation,
+    psa_jpake_io_mode_t io_mode)
+{
+    psa_jpake_computation_stage_t *stage =
+        &operation->computation_stage.jpake;
+
+    if (stage->step == PSA_PAKE_STEP_ZK_PROOF) {
+        /* End of an input/output */
+        if (io_mode == PSA_JPAKE_INPUT) {
+            stage->inputs++;
+            if (stage->inputs == PSA_JPAKE_EXPECTED_INPUTS(stage->round)) {
+                stage->io_mode = PSA_JPAKE_OUTPUT;
+            }
+        }
+        if (io_mode == PSA_JPAKE_OUTPUT) {
+            stage->outputs++;
+            if (stage->outputs == PSA_JPAKE_EXPECTED_OUTPUTS(stage->round)) {
+                stage->io_mode = PSA_JPAKE_INPUT;
+            }
+        }
+        if (stage->inputs == PSA_JPAKE_EXPECTED_INPUTS(stage->round) &&
+            stage->outputs == PSA_JPAKE_EXPECTED_OUTPUTS(stage->round)) {
+            /* End of a round, move to the next round */
+            stage->inputs = 0;
+            stage->outputs = 0;
+            stage->round++;
+        }
+        stage->step = PSA_PAKE_STEP_KEY_SHARE;
+    } else {
+        stage->step++;
+    }
+    return PSA_SUCCESS;
+}
+
+#endif /* PSA_WANT_ALG_JPAKE */
+
+psa_status_t psa_pake_output(
+    psa_pake_operation_t *operation,
+    psa_pake_step_t step,
+    uint8_t *output_external,
+    size_t output_size,
+    size_t *output_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_crypto_driver_pake_step_t driver_step = PSA_JPAKE_STEP_INVALID;
+    LOCAL_OUTPUT_DECLARE(output_external, output);
+    *output_length = 0;
+
+    if (operation->stage == PSA_PAKE_OPERATION_STAGE_COLLECT_INPUTS) {
+        status = psa_pake_complete_inputs(operation);
+        if (status != PSA_SUCCESS) {
+            goto exit;
+        }
+    }
+
+    if (operation->stage != PSA_PAKE_OPERATION_STAGE_COMPUTATION) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (output_size == 0) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    switch (operation->alg) {
+#if defined(PSA_WANT_ALG_JPAKE)
+        case PSA_ALG_JPAKE:
+            status = psa_jpake_prologue(operation, step, PSA_JPAKE_OUTPUT);
+            if (status != PSA_SUCCESS) {
+                goto exit;
+            }
+            driver_step = convert_jpake_computation_stage_to_driver_step(
+                &operation->computation_stage.jpake);
+            break;
+#endif /* PSA_WANT_ALG_JPAKE */
+        default:
+            (void) step;
+            status = PSA_ERROR_NOT_SUPPORTED;
+            goto exit;
+    }
+
+    LOCAL_OUTPUT_ALLOC(output_external, output_size, output);
+
+    status = psa_driver_wrapper_pake_output(operation, driver_step,
+                                            output, output_size, output_length);
+
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    switch (operation->alg) {
+#if defined(PSA_WANT_ALG_JPAKE)
+        case PSA_ALG_JPAKE:
+            status = psa_jpake_epilogue(operation, PSA_JPAKE_OUTPUT);
+            if (status != PSA_SUCCESS) {
+                goto exit;
+            }
+            break;
+#endif /* PSA_WANT_ALG_JPAKE */
+        default:
+            status = PSA_ERROR_NOT_SUPPORTED;
+            goto exit;
+    }
+
+exit:
+    LOCAL_OUTPUT_FREE(output_external, output);
+    if (status != PSA_SUCCESS) {
+        psa_pake_abort(operation);
+    }
+    return status;
+}
+
+psa_status_t psa_pake_input(
+    psa_pake_operation_t *operation,
+    psa_pake_step_t step,
+    const uint8_t *input_external,
+    size_t input_length)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_crypto_driver_pake_step_t driver_step = PSA_JPAKE_STEP_INVALID;
+    const size_t max_input_length = (size_t) PSA_PAKE_INPUT_SIZE(operation->alg,
+                                                                 operation->primitive,
+                                                                 step);
+    LOCAL_INPUT_DECLARE(input_external, input);
+
+    if (operation->stage == PSA_PAKE_OPERATION_STAGE_COLLECT_INPUTS) {
+        status = psa_pake_complete_inputs(operation);
+        if (status != PSA_SUCCESS) {
+            goto exit;
+        }
+    }
+
+    if (operation->stage != PSA_PAKE_OPERATION_STAGE_COMPUTATION) {
+        status =  PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+    if (input_length == 0 || input_length > max_input_length) {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+    switch (operation->alg) {
+#if defined(PSA_WANT_ALG_JPAKE)
+        case PSA_ALG_JPAKE:
+            status = psa_jpake_prologue(operation, step, PSA_JPAKE_INPUT);
+            if (status != PSA_SUCCESS) {
+                goto exit;
+            }
+            driver_step = convert_jpake_computation_stage_to_driver_step(
+                &operation->computation_stage.jpake);
+            break;
+#endif /* PSA_WANT_ALG_JPAKE */
+        default:
+            (void) step;
+            status = PSA_ERROR_NOT_SUPPORTED;
+            goto exit;
+    }
+
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    status = psa_driver_wrapper_pake_input(operation, driver_step,
+                                           input, input_length);
+
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    switch (operation->alg) {
+#if defined(PSA_WANT_ALG_JPAKE)
+        case PSA_ALG_JPAKE:
+            status = psa_jpake_epilogue(operation, PSA_JPAKE_INPUT);
+            if (status != PSA_SUCCESS) {
+                goto exit;
+            }
+            break;
+#endif /* PSA_WANT_ALG_JPAKE */
+        default:
+            status = PSA_ERROR_NOT_SUPPORTED;
+            goto exit;
+    }
+
+exit:
+    LOCAL_INPUT_FREE(input_external, input);
+    if (status != PSA_SUCCESS) {
+        psa_pake_abort(operation);
+    }
+    return status;
+}
+
+psa_status_t psa_pake_get_implicit_key(
+    psa_pake_operation_t *operation,
+    psa_key_derivation_operation_t *output)
+{
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+    psa_status_t abort_status = PSA_ERROR_CORRUPTION_DETECTED;
+    uint8_t shared_key[MBEDTLS_PSA_JPAKE_BUFFER_SIZE];
+    size_t shared_key_len = 0;
+
+    if (operation->stage != PSA_PAKE_OPERATION_STAGE_COMPUTATION) {
+        status = PSA_ERROR_BAD_STATE;
+        goto exit;
+    }
+
+#if defined(PSA_WANT_ALG_JPAKE)
+    if (operation->alg == PSA_ALG_JPAKE) {
+        psa_jpake_computation_stage_t *computation_stage =
+            &operation->computation_stage.jpake;
+        if (computation_stage->round != PSA_JPAKE_FINISHED) {
+            status = PSA_ERROR_BAD_STATE;
+            goto exit;
+        }
+    } else
+#endif /* PSA_WANT_ALG_JPAKE */
+    {
+        status = PSA_ERROR_NOT_SUPPORTED;
+        goto exit;
+    }
+
+    status = psa_driver_wrapper_pake_get_implicit_key(operation,
+                                                      shared_key,
+                                                      sizeof(shared_key),
+                                                      &shared_key_len);
+
+    if (status != PSA_SUCCESS) {
+        goto exit;
+    }
+
+    status = psa_key_derivation_input_bytes(output,
+                                            PSA_KEY_DERIVATION_INPUT_SECRET,
+                                            shared_key,
+                                            shared_key_len);
+
+    mbedtls_platform_zeroize(shared_key, sizeof(shared_key));
+exit:
+    abort_status = psa_pake_abort(operation);
+    return status == PSA_SUCCESS ? abort_status : status;
+}
+
+psa_status_t psa_pake_abort(
+    psa_pake_operation_t *operation)
+{
+    psa_status_t status = PSA_SUCCESS;
+
+    if (operation->stage == PSA_PAKE_OPERATION_STAGE_COMPUTATION) {
+        status = psa_driver_wrapper_pake_abort(operation);
+    }
+
+    if (operation->stage == PSA_PAKE_OPERATION_STAGE_COLLECT_INPUTS) {
+        if (operation->data.inputs.password != NULL) {
+            mbedtls_zeroize_and_free(operation->data.inputs.password,
+                                     operation->data.inputs.password_len);
+        }
+        if (operation->data.inputs.user != NULL) {
+            mbedtls_free(operation->data.inputs.user);
+        }
+        if (operation->data.inputs.peer != NULL) {
+            mbedtls_free(operation->data.inputs.peer);
+        }
+    }
+    memset(operation, 0, sizeof(psa_pake_operation_t));
+
+    return status;
+}
+#endif /* PSA_WANT_ALG_SOME_PAKE */
+
+/* Memory copying test hooks. These are called before input copy, after input
+ * copy, before output copy and after output copy, respectively.
+ * They are used by memory-poisoning tests to temporarily unpoison buffers
+ * while they are copied. */
+#if defined(MBEDTLS_TEST_HOOKS)
+void (*psa_input_pre_copy_hook)(const uint8_t *input, size_t input_len) = NULL;
+void (*psa_input_post_copy_hook)(const uint8_t *input, size_t input_len) = NULL;
+void (*psa_output_pre_copy_hook)(const uint8_t *output, size_t output_len) = NULL;
+void (*psa_output_post_copy_hook)(const uint8_t *output, size_t output_len) = NULL;
+#endif
+
+/** Copy from an input buffer to a local copy.
+ *
+ * \param[in] input             Pointer to input buffer.
+ * \param[in] input_len         Length of the input buffer.
+ * \param[out] input_copy       Pointer to a local copy in which to store the input data.
+ * \param[out] input_copy_len   Length of the local copy buffer.
+ * \return                      #PSA_SUCCESS, if the buffer was successfully
+ *                              copied.
+ * \return                      #PSA_ERROR_CORRUPTION_DETECTED, if the local
+ *                              copy is too small to hold contents of the
+ *                              input buffer.
+ */
+MBEDTLS_STATIC_TESTABLE
+psa_status_t psa_crypto_copy_input(const uint8_t *input, size_t input_len,
+                                   uint8_t *input_copy, size_t input_copy_len)
+{
+    if (input_len > input_copy_len) {
+        return PSA_ERROR_CORRUPTION_DETECTED;
+    }
+
+#if defined(MBEDTLS_TEST_HOOKS)
+    if (psa_input_pre_copy_hook != NULL) {
+        psa_input_pre_copy_hook(input, input_len);
+    }
+#endif
+
+    if (input_len > 0) {
+        memcpy(input_copy, input, input_len);
+    }
+
+#if defined(MBEDTLS_TEST_HOOKS)
+    if (psa_input_post_copy_hook != NULL) {
+        psa_input_post_copy_hook(input, input_len);
+    }
+#endif
+
+    return PSA_SUCCESS;
+}
+
+/** Copy from a local output buffer into a user-supplied one.
+ *
+ * \param[in] output_copy       Pointer to a local buffer containing the output.
+ * \param[in] output_copy_len   Length of the local buffer.
+ * \param[out] output           Pointer to user-supplied output buffer.
+ * \param[out] output_len       Length of the user-supplied output buffer.
+ * \return                      #PSA_SUCCESS, if the buffer was successfully
+ *                              copied.
+ * \return                      #PSA_ERROR_BUFFER_TOO_SMALL, if the
+ *                              user-supplied output buffer is too small to
+ *                              hold the contents of the local buffer.
+ */
+MBEDTLS_STATIC_TESTABLE
+psa_status_t psa_crypto_copy_output(const uint8_t *output_copy, size_t output_copy_len,
+                                    uint8_t *output, size_t output_len)
+{
+    if (output_len < output_copy_len) {
+        return PSA_ERROR_BUFFER_TOO_SMALL;
+    }
+
+#if defined(MBEDTLS_TEST_HOOKS)
+    if (psa_output_pre_copy_hook != NULL) {
+        psa_output_pre_copy_hook(output, output_len);
+    }
+#endif
+
+    if (output_copy_len > 0) {
+        memcpy(output, output_copy, output_copy_len);
+    }
+
+#if defined(MBEDTLS_TEST_HOOKS)
+    if (psa_output_post_copy_hook != NULL) {
+        psa_output_post_copy_hook(output, output_len);
+    }
+#endif
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_crypto_local_input_alloc(const uint8_t *input, size_t input_len,
+                                          psa_crypto_local_input_t *local_input)
+{
+    psa_status_t status;
+
+    *local_input = PSA_CRYPTO_LOCAL_INPUT_INIT;
+
+    if (input_len == 0) {
+        return PSA_SUCCESS;
+    }
+
+    local_input->buffer = mbedtls_calloc(input_len, 1);
+    if (local_input->buffer == NULL) {
+        /* Since we dealt with the zero-length case above, we know that
+         * a NULL return value means a failure of allocation. */
+        return PSA_ERROR_INSUFFICIENT_MEMORY;
+    }
+    /* From now on, we must free local_input->buffer on error. */
+
+    local_input->length = input_len;
+
+    status = psa_crypto_copy_input(input, input_len,
+                                   local_input->buffer, local_input->length);
+    if (status != PSA_SUCCESS) {
+        goto error;
+    }
+
+    return PSA_SUCCESS;
+
+error:
+    mbedtls_free(local_input->buffer);
+    local_input->buffer = NULL;
+    local_input->length = 0;
+    return status;
+}
+
+void psa_crypto_local_input_free(psa_crypto_local_input_t *local_input)
+{
+    mbedtls_free(local_input->buffer);
+    local_input->buffer = NULL;
+    local_input->length = 0;
+}
+
+psa_status_t psa_crypto_local_output_alloc(uint8_t *output, size_t output_len,
+                                           psa_crypto_local_output_t *local_output)
+{
+    *local_output = PSA_CRYPTO_LOCAL_OUTPUT_INIT;
+
+    if (output_len == 0) {
+        return PSA_SUCCESS;
+    }
+    local_output->buffer = mbedtls_calloc(output_len, 1);
+    if (local_output->buffer == NULL) {
+        /* Since we dealt with the zero-length case above, we know that
+         * a NULL return value means a failure of allocation. */
+        return PSA_ERROR_INSUFFICIENT_MEMORY;
+    }
+    local_output->length = output_len;
+    local_output->original = output;
+
+    return PSA_SUCCESS;
+}
+
+psa_status_t psa_crypto_local_output_free(psa_crypto_local_output_t *local_output)
+{
+    psa_status_t status;
+
+    if (local_output->buffer == NULL) {
+        local_output->length = 0;
+        return PSA_SUCCESS;
+    }
+    if (local_output->original == NULL) {
+        /* We have an internal copy but nothing to copy back to. */
+        return PSA_ERROR_CORRUPTION_DETECTED;
+    }
+
+    status = psa_crypto_copy_output(local_output->buffer, local_output->length,
+                                    local_output->original, local_output->length);
+    if (status != PSA_SUCCESS) {
+        return status;
+    }
+
+    mbedtls_free(local_output->buffer);
+    local_output->buffer = NULL;
+    local_output->length = 0;
+
+    return PSA_SUCCESS;
+}
+
+#endif /* MBEDTLS_PSA_CRYPTO_C */