diff options
Diffstat (limited to 'thirdparty/mbedtls/library/psa_crypto_se.c')
| -rw-r--r-- | thirdparty/mbedtls/library/psa_crypto_se.c | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/thirdparty/mbedtls/library/psa_crypto_se.c b/thirdparty/mbedtls/library/psa_crypto_se.c new file mode 100644 index 0000000000..7a36a4f3a5 --- /dev/null +++ b/thirdparty/mbedtls/library/psa_crypto_se.c @@ -0,0 +1,373 @@ +/* + * PSA crypto support for secure element drivers + */ +/* + * Copyright The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later + */ + +#include "common.h" + +#if defined(MBEDTLS_PSA_CRYPTO_SE_C) + +#include <stdint.h> +#include <string.h> + +#include "psa/crypto_se_driver.h" + +#include "psa_crypto_se.h" + +#if defined(MBEDTLS_PSA_ITS_FILE_C) +#include "psa_crypto_its.h" +#else /* Native ITS implementation */ +#include "psa/error.h" +#include "psa/internal_trusted_storage.h" +#endif + +#include "mbedtls/platform.h" + + + +/****************************************************************/ +/* Driver lookup */ +/****************************************************************/ + +/* This structure is identical to psa_drv_se_context_t declared in + * `crypto_se_driver.h`, except that some parts are writable here + * (non-const, or pointer to non-const). */ +typedef struct { + void *persistent_data; + size_t persistent_data_size; + uintptr_t transient_data; +} psa_drv_se_internal_context_t; + +struct psa_se_drv_table_entry_s { + psa_key_location_t location; + const psa_drv_se_t *methods; + union { + psa_drv_se_internal_context_t internal; + psa_drv_se_context_t context; + } u; +}; + +static psa_se_drv_table_entry_t driver_table[PSA_MAX_SE_DRIVERS]; + +psa_se_drv_table_entry_t *psa_get_se_driver_entry( + psa_key_lifetime_t lifetime) +{ + size_t i; + psa_key_location_t location = PSA_KEY_LIFETIME_GET_LOCATION(lifetime); + /* In the driver table, location=0 means an entry that isn't used. + * No driver has a location of 0 because it's a reserved value + * (which designates transparent keys). Make sure we never return + * a driver entry for location 0. */ + if (location == 0) { + return NULL; + } + for (i = 0; i < PSA_MAX_SE_DRIVERS; i++) { + if (driver_table[i].location == location) { + return &driver_table[i]; + } + } + return NULL; +} + +const psa_drv_se_t *psa_get_se_driver_methods( + const psa_se_drv_table_entry_t *driver) +{ + return driver->methods; +} + +psa_drv_se_context_t *psa_get_se_driver_context( + psa_se_drv_table_entry_t *driver) +{ + return &driver->u.context; +} + +int psa_get_se_driver(psa_key_lifetime_t lifetime, + const psa_drv_se_t **p_methods, + psa_drv_se_context_t **p_drv_context) +{ + psa_se_drv_table_entry_t *driver = psa_get_se_driver_entry(lifetime); + if (p_methods != NULL) { + *p_methods = (driver ? driver->methods : NULL); + } + if (p_drv_context != NULL) { + *p_drv_context = (driver ? &driver->u.context : NULL); + } + return driver != NULL; +} + + + +/****************************************************************/ +/* Persistent data management */ +/****************************************************************/ + +static psa_status_t psa_get_se_driver_its_file_uid( + const psa_se_drv_table_entry_t *driver, + psa_storage_uid_t *uid) +{ + if (driver->location > PSA_MAX_SE_LOCATION) { + return PSA_ERROR_NOT_SUPPORTED; + } + + /* ITS file sizes are limited to 32 bits. */ + if (driver->u.internal.persistent_data_size > UINT32_MAX) { + return PSA_ERROR_NOT_SUPPORTED; + } + + /* See the documentation of PSA_CRYPTO_SE_DRIVER_ITS_UID_BASE. */ + *uid = PSA_CRYPTO_SE_DRIVER_ITS_UID_BASE + driver->location; + return PSA_SUCCESS; +} + +psa_status_t psa_load_se_persistent_data( + const psa_se_drv_table_entry_t *driver) +{ + psa_status_t status; + psa_storage_uid_t uid; + size_t length; + + status = psa_get_se_driver_its_file_uid(driver, &uid); + if (status != PSA_SUCCESS) { + return status; + } + + /* Read the amount of persistent data that the driver requests. + * If the data in storage is larger, it is truncated. If the data + * in storage is smaller, silently keep what is already at the end + * of the output buffer. */ + /* psa_get_se_driver_its_file_uid ensures that the size_t + * persistent_data_size is in range, but compilers don't know that, + * so cast to reassure them. */ + return psa_its_get(uid, 0, + (uint32_t) driver->u.internal.persistent_data_size, + driver->u.internal.persistent_data, + &length); +} + +psa_status_t psa_save_se_persistent_data( + const psa_se_drv_table_entry_t *driver) +{ + psa_status_t status; + psa_storage_uid_t uid; + + status = psa_get_se_driver_its_file_uid(driver, &uid); + if (status != PSA_SUCCESS) { + return status; + } + + /* psa_get_se_driver_its_file_uid ensures that the size_t + * persistent_data_size is in range, but compilers don't know that, + * so cast to reassure them. */ + return psa_its_set(uid, + (uint32_t) driver->u.internal.persistent_data_size, + driver->u.internal.persistent_data, + 0); +} + +psa_status_t psa_destroy_se_persistent_data(psa_key_location_t location) +{ + psa_storage_uid_t uid; + if (location > PSA_MAX_SE_LOCATION) { + return PSA_ERROR_NOT_SUPPORTED; + } + uid = PSA_CRYPTO_SE_DRIVER_ITS_UID_BASE + location; + return psa_its_remove(uid); +} + +psa_status_t psa_find_se_slot_for_key( + const psa_key_attributes_t *attributes, + psa_key_creation_method_t method, + psa_se_drv_table_entry_t *driver, + psa_key_slot_number_t *slot_number) +{ + psa_status_t status; + psa_key_location_t key_location = + PSA_KEY_LIFETIME_GET_LOCATION(psa_get_key_lifetime(attributes)); + + /* If the location is wrong, it's a bug in the library. */ + if (driver->location != key_location) { + return PSA_ERROR_CORRUPTION_DETECTED; + } + + /* If the driver doesn't support key creation in any way, give up now. */ + if (driver->methods->key_management == NULL) { + return PSA_ERROR_NOT_SUPPORTED; + } + + if (psa_get_key_slot_number(attributes, slot_number) == PSA_SUCCESS) { + /* The application wants to use a specific slot. Allow it if + * the driver supports it. On a system with isolation, + * the crypto service must check that the application is + * permitted to request this slot. */ + psa_drv_se_validate_slot_number_t p_validate_slot_number = + driver->methods->key_management->p_validate_slot_number; + if (p_validate_slot_number == NULL) { + return PSA_ERROR_NOT_SUPPORTED; + } + status = p_validate_slot_number(&driver->u.context, + driver->u.internal.persistent_data, + attributes, method, + *slot_number); + } else if (method == PSA_KEY_CREATION_REGISTER) { + /* The application didn't specify a slot number. This doesn't + * make sense when registering a slot. */ + return PSA_ERROR_INVALID_ARGUMENT; + } else { + /* The application didn't tell us which slot to use. Let the driver + * choose. This is the normal case. */ + psa_drv_se_allocate_key_t p_allocate = + driver->methods->key_management->p_allocate; + if (p_allocate == NULL) { + return PSA_ERROR_NOT_SUPPORTED; + } + status = p_allocate(&driver->u.context, + driver->u.internal.persistent_data, + attributes, method, + slot_number); + } + return status; +} + +psa_status_t psa_destroy_se_key(psa_se_drv_table_entry_t *driver, + psa_key_slot_number_t slot_number) +{ + psa_status_t status; + psa_status_t storage_status; + /* Normally a missing method would mean that the action is not + * supported. But psa_destroy_key() is not supposed to return + * PSA_ERROR_NOT_SUPPORTED: if you can create a key, you should + * be able to destroy it. The only use case for a driver that + * does not have a way to destroy keys at all is if the keys are + * locked in a read-only state: we can use the keys but not + * destroy them. Hence, if the driver doesn't support destroying + * keys, it's really a lack of permission. */ + if (driver->methods->key_management == NULL || + driver->methods->key_management->p_destroy == NULL) { + return PSA_ERROR_NOT_PERMITTED; + } + status = driver->methods->key_management->p_destroy( + &driver->u.context, + driver->u.internal.persistent_data, + slot_number); + storage_status = psa_save_se_persistent_data(driver); + return status == PSA_SUCCESS ? storage_status : status; +} + +psa_status_t psa_init_all_se_drivers(void) +{ + size_t i; + for (i = 0; i < PSA_MAX_SE_DRIVERS; i++) { + psa_se_drv_table_entry_t *driver = &driver_table[i]; + if (driver->location == 0) { + continue; /* skipping unused entry */ + } + const psa_drv_se_t *methods = psa_get_se_driver_methods(driver); + if (methods->p_init != NULL) { + psa_status_t status = methods->p_init( + &driver->u.context, + driver->u.internal.persistent_data, + driver->location); + if (status != PSA_SUCCESS) { + return status; + } + status = psa_save_se_persistent_data(driver); + if (status != PSA_SUCCESS) { + return status; + } + } + } + return PSA_SUCCESS; +} + + + +/****************************************************************/ +/* Driver registration */ +/****************************************************************/ + +psa_status_t psa_register_se_driver( + psa_key_location_t location, + const psa_drv_se_t *methods) +{ + size_t i; + psa_status_t status; + + if (methods->hal_version != PSA_DRV_SE_HAL_VERSION) { + return PSA_ERROR_NOT_SUPPORTED; + } + /* Driver table entries are 0-initialized. 0 is not a valid driver + * location because it means a transparent key. */ + MBEDTLS_STATIC_ASSERT(PSA_KEY_LOCATION_LOCAL_STORAGE == 0, + "Secure element support requires 0 to mean a local key"); + + if (location == PSA_KEY_LOCATION_LOCAL_STORAGE) { + return PSA_ERROR_INVALID_ARGUMENT; + } + if (location > PSA_MAX_SE_LOCATION) { + return PSA_ERROR_NOT_SUPPORTED; + } + + for (i = 0; i < PSA_MAX_SE_DRIVERS; i++) { + if (driver_table[i].location == 0) { + break; + } + /* Check that location isn't already in use up to the first free + * entry. Since entries are created in order and never deleted, + * there can't be a used entry after the first free entry. */ + if (driver_table[i].location == location) { + return PSA_ERROR_ALREADY_EXISTS; + } + } + if (i == PSA_MAX_SE_DRIVERS) { + return PSA_ERROR_INSUFFICIENT_MEMORY; + } + + driver_table[i].location = location; + driver_table[i].methods = methods; + driver_table[i].u.internal.persistent_data_size = + methods->persistent_data_size; + + if (methods->persistent_data_size != 0) { + driver_table[i].u.internal.persistent_data = + mbedtls_calloc(1, methods->persistent_data_size); + if (driver_table[i].u.internal.persistent_data == NULL) { + status = PSA_ERROR_INSUFFICIENT_MEMORY; + goto error; + } + /* Load the driver's persistent data. On first use, the persistent + * data does not exist in storage, and is initialized to + * all-bits-zero by the calloc call just above. */ + status = psa_load_se_persistent_data(&driver_table[i]); + if (status != PSA_SUCCESS && status != PSA_ERROR_DOES_NOT_EXIST) { + goto error; + } + } + + return PSA_SUCCESS; + +error: + memset(&driver_table[i], 0, sizeof(driver_table[i])); + return status; +} + +void psa_unregister_all_se_drivers(void) +{ + size_t i; + for (i = 0; i < PSA_MAX_SE_DRIVERS; i++) { + if (driver_table[i].u.internal.persistent_data != NULL) { + mbedtls_free(driver_table[i].u.internal.persistent_data); + } + } + memset(driver_table, 0, sizeof(driver_table)); +} + + + +/****************************************************************/ +/* The end */ +/****************************************************************/ + +#endif /* MBEDTLS_PSA_CRYPTO_SE_C */ |