diff options
Diffstat (limited to 'thirdparty/mbedtls/library/ssl_tls13_client.c')
| -rw-r--r-- | thirdparty/mbedtls/library/ssl_tls13_client.c | 3181 |
1 files changed, 3181 insertions, 0 deletions
diff --git a/thirdparty/mbedtls/library/ssl_tls13_client.c b/thirdparty/mbedtls/library/ssl_tls13_client.c new file mode 100644 index 0000000000..7fcc394319 --- /dev/null +++ b/thirdparty/mbedtls/library/ssl_tls13_client.c @@ -0,0 +1,3181 @@ +/* + * TLS 1.3 client-side functions + * + * Copyright The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later + */ + +#include "common.h" + +#if defined(MBEDTLS_SSL_CLI_C) && defined(MBEDTLS_SSL_PROTO_TLS1_3) + +#include <string.h> + +#include "debug_internal.h" +#include "mbedtls/error.h" +#include "mbedtls/platform.h" + +#include "ssl_misc.h" +#include "ssl_client.h" +#include "ssl_tls13_keys.h" +#include "ssl_debug_helpers.h" +#include "mbedtls/psa_util.h" + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED) +/* Define a local translating function to save code size by not using too many + * arguments in each translating place. */ +static int local_err_translation(psa_status_t status) +{ + return psa_status_to_mbedtls(status, psa_to_ssl_errors, + ARRAY_LENGTH(psa_to_ssl_errors), + psa_generic_status_to_mbedtls); +} +#define PSA_TO_MBEDTLS_ERR(status) local_err_translation(status) +#endif + +/* Write extensions */ + +/* + * ssl_tls13_write_supported_versions_ext(): + * + * struct { + * ProtocolVersion versions<2..254>; + * } SupportedVersions; + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_write_supported_versions_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + unsigned char *end, + size_t *out_len) +{ + unsigned char *p = buf; + unsigned char versions_len = (ssl->handshake->min_tls_version <= + MBEDTLS_SSL_VERSION_TLS1_2) ? 4 : 2; + + *out_len = 0; + + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding supported versions extension")); + + /* Check if we have space to write the extension: + * - extension_type (2 bytes) + * - extension_data_length (2 bytes) + * - versions_length (1 byte ) + * - versions (2 or 4 bytes) + */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 5 + versions_len); + + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS, p, 0); + MBEDTLS_PUT_UINT16_BE(versions_len + 1, p, 2); + p += 4; + + /* Length of versions */ + *p++ = versions_len; + + /* Write values of supported versions. + * They are defined by the configuration. + * Currently, we advertise only TLS 1.3 or both TLS 1.3 and TLS 1.2. + */ + mbedtls_ssl_write_version(p, MBEDTLS_SSL_TRANSPORT_STREAM, + MBEDTLS_SSL_VERSION_TLS1_3); + MBEDTLS_SSL_DEBUG_MSG(3, ("supported version: [3:4]")); + + + if (ssl->handshake->min_tls_version <= MBEDTLS_SSL_VERSION_TLS1_2) { + mbedtls_ssl_write_version(p + 2, MBEDTLS_SSL_TRANSPORT_STREAM, + MBEDTLS_SSL_VERSION_TLS1_2); + MBEDTLS_SSL_DEBUG_MSG(3, ("supported version: [3:3]")); + } + + *out_len = 5 + versions_len; + + mbedtls_ssl_tls13_set_hs_sent_ext_mask( + ssl, MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS); + + return 0; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_parse_supported_versions_ext(mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end) +{ + ((void) ssl); + + MBEDTLS_SSL_CHK_BUF_READ_PTR(buf, end, 2); + if (mbedtls_ssl_read_version(buf, ssl->conf->transport) != + MBEDTLS_SSL_VERSION_TLS1_3) { + MBEDTLS_SSL_DEBUG_MSG(1, ("unexpected version")); + + MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, + MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + + if (&buf[2] != end) { + MBEDTLS_SSL_DEBUG_MSG( + 1, ("supported_versions ext data length incorrect")); + MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, + MBEDTLS_ERR_SSL_DECODE_ERROR); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + return 0; +} + +#if defined(MBEDTLS_SSL_ALPN) +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_parse_alpn_ext(mbedtls_ssl_context *ssl, + const unsigned char *buf, size_t len) +{ + const unsigned char *p = buf; + const unsigned char *end = buf + len; + size_t protocol_name_list_len, protocol_name_len; + const unsigned char *protocol_name_list_end; + + /* If we didn't send it, the server shouldn't send it */ + if (ssl->conf->alpn_list == NULL) { + return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; + } + + /* + * opaque ProtocolName<1..2^8-1>; + * + * struct { + * ProtocolName protocol_name_list<2..2^16-1> + * } ProtocolNameList; + * + * the "ProtocolNameList" MUST contain exactly one "ProtocolName" + */ + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 2); + protocol_name_list_len = MBEDTLS_GET_UINT16_BE(p, 0); + p += 2; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, protocol_name_list_len); + protocol_name_list_end = p + protocol_name_list_len; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, protocol_name_list_end, 1); + protocol_name_len = *p++; + + /* Check that the server chosen protocol was in our list and save it */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, protocol_name_list_end, protocol_name_len); + for (const char **alpn = ssl->conf->alpn_list; *alpn != NULL; alpn++) { + if (protocol_name_len == strlen(*alpn) && + memcmp(p, *alpn, protocol_name_len) == 0) { + ssl->alpn_chosen = *alpn; + return 0; + } + } + + return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; +} +#endif /* MBEDTLS_SSL_ALPN */ + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_reset_key_share(mbedtls_ssl_context *ssl) +{ + uint16_t group_id = ssl->handshake->offered_group_id; + + if (group_id == 0) { + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED) + if (mbedtls_ssl_tls13_named_group_is_ecdhe(group_id) || + mbedtls_ssl_tls13_named_group_is_ffdh(group_id)) { + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; + + /* Destroy generated private key. */ + status = psa_destroy_key(ssl->handshake->xxdh_psa_privkey); + if (status != PSA_SUCCESS) { + ret = PSA_TO_MBEDTLS_ERR(status); + MBEDTLS_SSL_DEBUG_RET(1, "psa_destroy_key", ret); + return ret; + } + + ssl->handshake->xxdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT; + return 0; + } else +#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED */ + if (0 /* other KEMs? */) { + /* Do something */ + } + + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; +} + +/* + * Functions for writing key_share extension. + */ +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED) +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_get_default_group_id(mbedtls_ssl_context *ssl, + uint16_t *group_id) +{ + int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; + + +#if defined(PSA_WANT_ALG_ECDH) || defined(PSA_WANT_ALG_FFDH) + const uint16_t *group_list = mbedtls_ssl_get_groups(ssl); + /* Pick first available ECDHE group compatible with TLS 1.3 */ + if (group_list == NULL) { + return MBEDTLS_ERR_SSL_BAD_CONFIG; + } + + for (; *group_list != 0; group_list++) { +#if defined(PSA_WANT_ALG_ECDH) + if ((mbedtls_ssl_get_psa_curve_info_from_tls_id( + *group_list, NULL, NULL) == PSA_SUCCESS) && + mbedtls_ssl_tls13_named_group_is_ecdhe(*group_list)) { + *group_id = *group_list; + return 0; + } +#endif +#if defined(PSA_WANT_ALG_FFDH) + if (mbedtls_ssl_tls13_named_group_is_ffdh(*group_list)) { + *group_id = *group_list; + return 0; + } +#endif + } +#else + ((void) ssl); + ((void) group_id); +#endif /* PSA_WANT_ALG_ECDH || PSA_WANT_ALG_FFDH */ + + return ret; +} + +/* + * ssl_tls13_write_key_share_ext + * + * Structure of key_share extension in ClientHello: + * + * struct { + * NamedGroup group; + * opaque key_exchange<1..2^16-1>; + * } KeyShareEntry; + * struct { + * KeyShareEntry client_shares<0..2^16-1>; + * } KeyShareClientHello; + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_write_key_share_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + unsigned char *end, + size_t *out_len) +{ + unsigned char *p = buf; + unsigned char *client_shares; /* Start of client_shares */ + size_t client_shares_len; /* Length of client_shares */ + uint16_t group_id; + int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; + + *out_len = 0; + + /* Check if we have space for header and length fields: + * - extension_type (2 bytes) + * - extension_data_length (2 bytes) + * - client_shares_length (2 bytes) + */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 6); + p += 6; + + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello: adding key share extension")); + + /* HRR could already have requested something else. */ + group_id = ssl->handshake->offered_group_id; + if (!mbedtls_ssl_tls13_named_group_is_ecdhe(group_id) && + !mbedtls_ssl_tls13_named_group_is_ffdh(group_id)) { + MBEDTLS_SSL_PROC_CHK(ssl_tls13_get_default_group_id(ssl, + &group_id)); + } + + /* + * Dispatch to type-specific key generation function. + * + * So far, we're only supporting ECDHE. With the introduction + * of PQC KEMs, we'll want to have multiple branches, one per + * type of KEM, and dispatch to the corresponding crypto. And + * only one key share entry is allowed. + */ + client_shares = p; +#if defined(PSA_WANT_ALG_ECDH) || defined(PSA_WANT_ALG_FFDH) + if (mbedtls_ssl_tls13_named_group_is_ecdhe(group_id) || + mbedtls_ssl_tls13_named_group_is_ffdh(group_id)) { + /* Pointer to group */ + unsigned char *group = p; + /* Length of key_exchange */ + size_t key_exchange_len = 0; + + /* Check there is space for header of KeyShareEntry + * - group (2 bytes) + * - key_exchange_length (2 bytes) + */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 4); + p += 4; + ret = mbedtls_ssl_tls13_generate_and_write_xxdh_key_exchange( + ssl, group_id, p, end, &key_exchange_len); + p += key_exchange_len; + if (ret != 0) { + return ret; + } + + /* Write group */ + MBEDTLS_PUT_UINT16_BE(group_id, group, 0); + /* Write key_exchange_length */ + MBEDTLS_PUT_UINT16_BE(key_exchange_len, group, 2); + } else +#endif /* PSA_WANT_ALG_ECDH || PSA_WANT_ALG_FFDH */ + if (0 /* other KEMs? */) { + /* Do something */ + } else { + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + + /* Length of client_shares */ + client_shares_len = p - client_shares; + if (client_shares_len == 0) { + MBEDTLS_SSL_DEBUG_MSG(1, ("No key share defined.")); + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + /* Write extension_type */ + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_KEY_SHARE, buf, 0); + /* Write extension_data_length */ + MBEDTLS_PUT_UINT16_BE(client_shares_len + 2, buf, 2); + /* Write client_shares_length */ + MBEDTLS_PUT_UINT16_BE(client_shares_len, buf, 4); + + /* Update offered_group_id field */ + ssl->handshake->offered_group_id = group_id; + + /* Output the total length of key_share extension. */ + *out_len = p - buf; + + MBEDTLS_SSL_DEBUG_BUF( + 3, "client hello, key_share extension", buf, *out_len); + + mbedtls_ssl_tls13_set_hs_sent_ext_mask(ssl, MBEDTLS_TLS_EXT_KEY_SHARE); + +cleanup: + + return ret; +} +#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED */ + +/* + * ssl_tls13_parse_hrr_key_share_ext() + * Parse key_share extension in Hello Retry Request + * + * struct { + * NamedGroup selected_group; + * } KeyShareHelloRetryRequest; + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_parse_hrr_key_share_ext(mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end) +{ +#if defined(PSA_WANT_ALG_ECDH) || defined(PSA_WANT_ALG_FFDH) + const unsigned char *p = buf; + int selected_group; + int found = 0; + + const uint16_t *group_list = mbedtls_ssl_get_groups(ssl); + if (group_list == NULL) { + return MBEDTLS_ERR_SSL_BAD_CONFIG; + } + + MBEDTLS_SSL_DEBUG_BUF(3, "key_share extension", p, end - buf); + + /* Read selected_group */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 2); + selected_group = MBEDTLS_GET_UINT16_BE(p, 0); + MBEDTLS_SSL_DEBUG_MSG(3, ("selected_group ( %d )", selected_group)); + + /* Upon receipt of this extension in a HelloRetryRequest, the client + * MUST first verify that the selected_group field corresponds to a + * group which was provided in the "supported_groups" extension in the + * original ClientHello. + * The supported_group was based on the info in ssl->conf->group_list. + * + * If the server provided a key share that was not sent in the ClientHello + * then the client MUST abort the handshake with an "illegal_parameter" alert. + */ + for (; *group_list != 0; group_list++) { +#if defined(PSA_WANT_ALG_ECDH) + if (mbedtls_ssl_tls13_named_group_is_ecdhe(*group_list)) { + if ((mbedtls_ssl_get_psa_curve_info_from_tls_id( + *group_list, NULL, NULL) == PSA_ERROR_NOT_SUPPORTED) || + *group_list != selected_group) { + found = 1; + break; + } + } +#endif /* PSA_WANT_ALG_ECDH */ +#if defined(PSA_WANT_ALG_FFDH) + if (mbedtls_ssl_tls13_named_group_is_ffdh(*group_list)) { + found = 1; + break; + } +#endif /* PSA_WANT_ALG_FFDH */ + } + + /* Client MUST verify that the selected_group field does not + * correspond to a group which was provided in the "key_share" + * extension in the original ClientHello. If the server sent an + * HRR message with a key share already provided in the + * ClientHello then the client MUST abort the handshake with + * an "illegal_parameter" alert. + */ + if (found == 0 || selected_group == ssl->handshake->offered_group_id) { + MBEDTLS_SSL_DEBUG_MSG(1, ("Invalid key share in HRR")); + MBEDTLS_SSL_PEND_FATAL_ALERT( + MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, + MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + + /* Remember server's preference for next ClientHello */ + ssl->handshake->offered_group_id = selected_group; + + return 0; +#else /* PSA_WANT_ALG_ECDH || PSA_WANT_ALG_FFDH */ + (void) ssl; + (void) buf; + (void) end; + return MBEDTLS_ERR_SSL_BAD_CONFIG; +#endif /* PSA_WANT_ALG_ECDH || PSA_WANT_ALG_FFDH */ +} + +/* + * ssl_tls13_parse_key_share_ext() + * Parse key_share extension in Server Hello + * + * struct { + * KeyShareEntry server_share; + * } KeyShareServerHello; + * struct { + * NamedGroup group; + * opaque key_exchange<1..2^16-1>; + * } KeyShareEntry; + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_parse_key_share_ext(mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + const unsigned char *p = buf; + uint16_t group, offered_group; + + /* ... + * NamedGroup group; (2 bytes) + * ... + */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 2); + group = MBEDTLS_GET_UINT16_BE(p, 0); + p += 2; + + /* Check that the chosen group matches the one we offered. */ + offered_group = ssl->handshake->offered_group_id; + if (offered_group != group) { + MBEDTLS_SSL_DEBUG_MSG( + 1, ("Invalid server key share, our group %u, their group %u", + (unsigned) offered_group, (unsigned) group)); + MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE, + MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE); + return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; + } + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED) + if (mbedtls_ssl_tls13_named_group_is_ecdhe(group) || + mbedtls_ssl_tls13_named_group_is_ffdh(group)) { + MBEDTLS_SSL_DEBUG_MSG(2, + ("DHE group name: %s", mbedtls_ssl_named_group_to_str(group))); + ret = mbedtls_ssl_tls13_read_public_xxdhe_share(ssl, p, end - p); + if (ret != 0) { + return ret; + } + } else +#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED */ + if (0 /* other KEMs? */) { + /* Do something */ + } else { + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + + return ret; +} + +/* + * ssl_tls13_parse_cookie_ext() + * Parse cookie extension in Hello Retry Request + * + * struct { + * opaque cookie<1..2^16-1>; + * } Cookie; + * + * When sending a HelloRetryRequest, the server MAY provide a "cookie" + * extension to the client (this is an exception to the usual rule that + * the only extensions that may be sent are those that appear in the + * ClientHello). When sending the new ClientHello, the client MUST copy + * the contents of the extension received in the HelloRetryRequest into + * a "cookie" extension in the new ClientHello. Clients MUST NOT use + * cookies in their initial ClientHello in subsequent connections. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_parse_cookie_ext(mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end) +{ + uint16_t cookie_len; + const unsigned char *p = buf; + mbedtls_ssl_handshake_params *handshake = ssl->handshake; + + /* Retrieve length field of cookie */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 2); + cookie_len = MBEDTLS_GET_UINT16_BE(p, 0); + p += 2; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, cookie_len); + MBEDTLS_SSL_DEBUG_BUF(3, "cookie extension", p, cookie_len); + + mbedtls_free(handshake->cookie); + handshake->cookie_len = 0; + handshake->cookie = mbedtls_calloc(1, cookie_len); + if (handshake->cookie == NULL) { + MBEDTLS_SSL_DEBUG_MSG(1, + ("alloc failed ( %ud bytes )", + cookie_len)); + return MBEDTLS_ERR_SSL_ALLOC_FAILED; + } + + memcpy(handshake->cookie, p, cookie_len); + handshake->cookie_len = cookie_len; + + return 0; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_write_cookie_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + unsigned char *end, + size_t *out_len) +{ + unsigned char *p = buf; + *out_len = 0; + mbedtls_ssl_handshake_params *handshake = ssl->handshake; + + if (handshake->cookie == NULL) { + MBEDTLS_SSL_DEBUG_MSG(3, ("no cookie to send; skip extension")); + return 0; + } + + MBEDTLS_SSL_DEBUG_BUF(3, "client hello, cookie", + handshake->cookie, + handshake->cookie_len); + + MBEDTLS_SSL_CHK_BUF_PTR(p, end, handshake->cookie_len + 6); + + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding cookie extension")); + + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_COOKIE, p, 0); + MBEDTLS_PUT_UINT16_BE(handshake->cookie_len + 2, p, 2); + MBEDTLS_PUT_UINT16_BE(handshake->cookie_len, p, 4); + p += 6; + + /* Cookie */ + memcpy(p, handshake->cookie, handshake->cookie_len); + + *out_len = handshake->cookie_len + 6; + + mbedtls_ssl_tls13_set_hs_sent_ext_mask(ssl, MBEDTLS_TLS_EXT_COOKIE); + + return 0; +} + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) +/* + * ssl_tls13_write_psk_key_exchange_modes_ext() structure: + * + * enum { psk_ke( 0 ), psk_dhe_ke( 1 ), ( 255 ) } PskKeyExchangeMode; + * + * struct { + * PskKeyExchangeMode ke_modes<1..255>; + * } PskKeyExchangeModes; + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_write_psk_key_exchange_modes_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + unsigned char *end, + size_t *out_len) +{ + unsigned char *p = buf; + int ke_modes_len = 0; + + ((void) ke_modes_len); + *out_len = 0; + + /* Skip writing extension if no PSK key exchange mode + * is enabled in the config. + */ + if (!mbedtls_ssl_conf_tls13_is_some_psk_enabled(ssl)) { + MBEDTLS_SSL_DEBUG_MSG(3, ("skip psk_key_exchange_modes extension")); + return 0; + } + + /* Require 7 bytes of data, otherwise fail, + * even if extension might be shorter. + */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 7); + MBEDTLS_SSL_DEBUG_MSG( + 3, ("client hello, adding psk_key_exchange_modes extension")); + + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_PSK_KEY_EXCHANGE_MODES, p, 0); + + /* Skip extension length (2 bytes) and + * ke_modes length (1 byte) for now. + */ + p += 5; + + if (mbedtls_ssl_conf_tls13_is_psk_ephemeral_enabled(ssl)) { + *p++ = MBEDTLS_SSL_TLS1_3_PSK_MODE_ECDHE; + ke_modes_len++; + + MBEDTLS_SSL_DEBUG_MSG(4, ("Adding PSK-ECDHE key exchange mode")); + } + + if (mbedtls_ssl_conf_tls13_is_psk_enabled(ssl)) { + *p++ = MBEDTLS_SSL_TLS1_3_PSK_MODE_PURE; + ke_modes_len++; + + MBEDTLS_SSL_DEBUG_MSG(4, ("Adding pure PSK key exchange mode")); + } + + /* Now write the extension and ke_modes length */ + MBEDTLS_PUT_UINT16_BE(ke_modes_len + 1, buf, 2); + buf[4] = ke_modes_len; + + *out_len = p - buf; + + mbedtls_ssl_tls13_set_hs_sent_ext_mask( + ssl, MBEDTLS_TLS_EXT_PSK_KEY_EXCHANGE_MODES); + + return 0; +} + +static psa_algorithm_t ssl_tls13_get_ciphersuite_hash_alg(int ciphersuite) +{ + const mbedtls_ssl_ciphersuite_t *ciphersuite_info = NULL; + ciphersuite_info = mbedtls_ssl_ciphersuite_from_id(ciphersuite); + + if (ciphersuite_info != NULL) { + return mbedtls_md_psa_alg_from_type((mbedtls_md_type_t) ciphersuite_info->mac); + } + + return PSA_ALG_NONE; +} + +#if defined(MBEDTLS_SSL_SESSION_TICKETS) +static int ssl_tls13_has_configured_ticket(mbedtls_ssl_context *ssl) +{ + mbedtls_ssl_session *session = ssl->session_negotiate; + return ssl->handshake->resume && + session != NULL && session->ticket != NULL && + mbedtls_ssl_conf_tls13_is_kex_mode_enabled( + ssl, mbedtls_ssl_tls13_session_get_ticket_flags( + session, MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ALL)); +} + +#if defined(MBEDTLS_SSL_EARLY_DATA) +static int ssl_tls13_early_data_has_valid_ticket(mbedtls_ssl_context *ssl) +{ + mbedtls_ssl_session *session = ssl->session_negotiate; + return ssl->handshake->resume && + session->tls_version == MBEDTLS_SSL_VERSION_TLS1_3 && + mbedtls_ssl_tls13_session_ticket_allow_early_data(session) && + mbedtls_ssl_tls13_cipher_suite_is_offered(ssl, session->ciphersuite); +} +#endif + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_ticket_get_identity(mbedtls_ssl_context *ssl, + psa_algorithm_t *hash_alg, + const unsigned char **identity, + size_t *identity_len) +{ + mbedtls_ssl_session *session = ssl->session_negotiate; + + if (!ssl_tls13_has_configured_ticket(ssl)) { + return -1; + } + + *hash_alg = ssl_tls13_get_ciphersuite_hash_alg(session->ciphersuite); + *identity = session->ticket; + *identity_len = session->ticket_len; + return 0; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_ticket_get_psk(mbedtls_ssl_context *ssl, + psa_algorithm_t *hash_alg, + const unsigned char **psk, + size_t *psk_len) +{ + + mbedtls_ssl_session *session = ssl->session_negotiate; + + if (!ssl_tls13_has_configured_ticket(ssl)) { + return -1; + } + + *hash_alg = ssl_tls13_get_ciphersuite_hash_alg(session->ciphersuite); + *psk = session->resumption_key; + *psk_len = session->resumption_key_len; + + return 0; +} +#endif /* MBEDTLS_SSL_SESSION_TICKETS */ + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_psk_get_identity(mbedtls_ssl_context *ssl, + psa_algorithm_t *hash_alg, + const unsigned char **identity, + size_t *identity_len) +{ + + if (!mbedtls_ssl_conf_has_static_psk(ssl->conf)) { + return -1; + } + + *hash_alg = PSA_ALG_SHA_256; + *identity = ssl->conf->psk_identity; + *identity_len = ssl->conf->psk_identity_len; + return 0; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_psk_get_psk(mbedtls_ssl_context *ssl, + psa_algorithm_t *hash_alg, + const unsigned char **psk, + size_t *psk_len) +{ + + if (!mbedtls_ssl_conf_has_static_psk(ssl->conf)) { + return -1; + } + + *hash_alg = PSA_ALG_SHA_256; + *psk = ssl->conf->psk; + *psk_len = ssl->conf->psk_len; + return 0; +} + +static int ssl_tls13_get_configured_psk_count(mbedtls_ssl_context *ssl) +{ + int configured_psk_count = 0; +#if defined(MBEDTLS_SSL_SESSION_TICKETS) + if (ssl_tls13_has_configured_ticket(ssl)) { + MBEDTLS_SSL_DEBUG_MSG(3, ("Ticket is configured")); + configured_psk_count++; + } +#endif + if (mbedtls_ssl_conf_has_static_psk(ssl->conf)) { + MBEDTLS_SSL_DEBUG_MSG(3, ("PSK is configured")); + configured_psk_count++; + } + return configured_psk_count; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_write_identity(mbedtls_ssl_context *ssl, + unsigned char *buf, + unsigned char *end, + const unsigned char *identity, + size_t identity_len, + uint32_t obfuscated_ticket_age, + size_t *out_len) +{ + ((void) ssl); + *out_len = 0; + + /* + * - identity_len (2 bytes) + * - identity (psk_identity_len bytes) + * - obfuscated_ticket_age (4 bytes) + */ + MBEDTLS_SSL_CHK_BUF_PTR(buf, end, 6 + identity_len); + + MBEDTLS_PUT_UINT16_BE(identity_len, buf, 0); + memcpy(buf + 2, identity, identity_len); + MBEDTLS_PUT_UINT32_BE(obfuscated_ticket_age, buf, 2 + identity_len); + + MBEDTLS_SSL_DEBUG_BUF(4, "write identity", buf, 6 + identity_len); + + *out_len = 6 + identity_len; + + return 0; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_write_binder(mbedtls_ssl_context *ssl, + unsigned char *buf, + unsigned char *end, + int psk_type, + psa_algorithm_t hash_alg, + const unsigned char *psk, + size_t psk_len, + size_t *out_len) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + unsigned char binder_len; + unsigned char transcript[MBEDTLS_TLS1_3_MD_MAX_SIZE]; + size_t transcript_len = 0; + + *out_len = 0; + + binder_len = PSA_HASH_LENGTH(hash_alg); + + /* + * - binder_len (1 bytes) + * - binder (binder_len bytes) + */ + MBEDTLS_SSL_CHK_BUF_PTR(buf, end, 1 + binder_len); + + buf[0] = binder_len; + + /* Get current state of handshake transcript. */ + ret = mbedtls_ssl_get_handshake_transcript( + ssl, mbedtls_md_type_from_psa_alg(hash_alg), + transcript, sizeof(transcript), &transcript_len); + if (ret != 0) { + return ret; + } + + ret = mbedtls_ssl_tls13_create_psk_binder(ssl, hash_alg, + psk, psk_len, psk_type, + transcript, buf + 1); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_tls13_create_psk_binder", ret); + return ret; + } + MBEDTLS_SSL_DEBUG_BUF(4, "write binder", buf, 1 + binder_len); + + *out_len = 1 + binder_len; + + return 0; +} + +/* + * mbedtls_ssl_tls13_write_identities_of_pre_shared_key_ext() structure: + * + * struct { + * opaque identity<1..2^16-1>; + * uint32 obfuscated_ticket_age; + * } PskIdentity; + * + * opaque PskBinderEntry<32..255>; + * + * struct { + * PskIdentity identities<7..2^16-1>; + * PskBinderEntry binders<33..2^16-1>; + * } OfferedPsks; + * + * struct { + * select (Handshake.msg_type) { + * case client_hello: OfferedPsks; + * ... + * }; + * } PreSharedKeyExtension; + * + */ +int mbedtls_ssl_tls13_write_identities_of_pre_shared_key_ext( + mbedtls_ssl_context *ssl, unsigned char *buf, unsigned char *end, + size_t *out_len, size_t *binders_len) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + int configured_psk_count = 0; + unsigned char *p = buf; + psa_algorithm_t hash_alg = PSA_ALG_NONE; + const unsigned char *identity; + size_t identity_len; + size_t l_binders_len = 0; + size_t output_len; + + *out_len = 0; + *binders_len = 0; + + /* Check if we have any PSKs to offer. If no, skip pre_shared_key */ + configured_psk_count = ssl_tls13_get_configured_psk_count(ssl); + if (configured_psk_count == 0) { + MBEDTLS_SSL_DEBUG_MSG(3, ("skip pre_shared_key extensions")); + return 0; + } + + MBEDTLS_SSL_DEBUG_MSG(4, ("Pre-configured PSK number = %d", + configured_psk_count)); + + /* Check if we have space to write the extension, binders included. + * - extension_type (2 bytes) + * - extension_data_len (2 bytes) + * - identities_len (2 bytes) + */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 6); + p += 6; + +#if defined(MBEDTLS_SSL_SESSION_TICKETS) + if (ssl_tls13_ticket_get_identity( + ssl, &hash_alg, &identity, &identity_len) == 0) { +#if defined(MBEDTLS_HAVE_TIME) + mbedtls_ms_time_t now = mbedtls_ms_time(); + mbedtls_ssl_session *session = ssl->session_negotiate; + /* The ticket age has been checked to be smaller than the + * `ticket_lifetime` in ssl_prepare_client_hello() which is smaller than + * 7 days (enforced in ssl_tls13_parse_new_session_ticket()) . Thus the + * cast to `uint32_t` of the ticket age is safe. */ + uint32_t obfuscated_ticket_age = + (uint32_t) (now - session->ticket_reception_time); + obfuscated_ticket_age += session->ticket_age_add; + + ret = ssl_tls13_write_identity(ssl, p, end, + identity, identity_len, + obfuscated_ticket_age, + &output_len); +#else + ret = ssl_tls13_write_identity(ssl, p, end, identity, identity_len, + 0, &output_len); +#endif /* MBEDTLS_HAVE_TIME */ + if (ret != 0) { + return ret; + } + + p += output_len; + l_binders_len += 1 + PSA_HASH_LENGTH(hash_alg); + } +#endif /* MBEDTLS_SSL_SESSION_TICKETS */ + + if (ssl_tls13_psk_get_identity( + ssl, &hash_alg, &identity, &identity_len) == 0) { + + ret = ssl_tls13_write_identity(ssl, p, end, identity, identity_len, 0, + &output_len); + if (ret != 0) { + return ret; + } + + p += output_len; + l_binders_len += 1 + PSA_HASH_LENGTH(hash_alg); + } + + MBEDTLS_SSL_DEBUG_MSG(3, + ("client hello, adding pre_shared_key extension, " + "omitting PSK binder list")); + + /* Take into account the two bytes for the length of the binders. */ + l_binders_len += 2; + /* Check if there is enough space for binders */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, l_binders_len); + + /* + * - extension_type (2 bytes) + * - extension_data_len (2 bytes) + * - identities_len (2 bytes) + */ + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_PRE_SHARED_KEY, buf, 0); + MBEDTLS_PUT_UINT16_BE(p - buf - 4 + l_binders_len, buf, 2); + MBEDTLS_PUT_UINT16_BE(p - buf - 6, buf, 4); + + *out_len = (p - buf) + l_binders_len; + *binders_len = l_binders_len; + + MBEDTLS_SSL_DEBUG_BUF(3, "pre_shared_key identities", buf, p - buf); + + return 0; +} + +int mbedtls_ssl_tls13_write_binders_of_pre_shared_key_ext( + mbedtls_ssl_context *ssl, unsigned char *buf, unsigned char *end) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + unsigned char *p = buf; + psa_algorithm_t hash_alg = PSA_ALG_NONE; + const unsigned char *psk; + size_t psk_len; + size_t output_len; + + /* Check if we have space to write binders_len. + * - binders_len (2 bytes) + */ + MBEDTLS_SSL_CHK_BUF_PTR(p, end, 2); + p += 2; + +#if defined(MBEDTLS_SSL_SESSION_TICKETS) + if (ssl_tls13_ticket_get_psk(ssl, &hash_alg, &psk, &psk_len) == 0) { + + ret = ssl_tls13_write_binder(ssl, p, end, + MBEDTLS_SSL_TLS1_3_PSK_RESUMPTION, + hash_alg, psk, psk_len, + &output_len); + if (ret != 0) { + return ret; + } + p += output_len; + } +#endif /* MBEDTLS_SSL_SESSION_TICKETS */ + + if (ssl_tls13_psk_get_psk(ssl, &hash_alg, &psk, &psk_len) == 0) { + + ret = ssl_tls13_write_binder(ssl, p, end, + MBEDTLS_SSL_TLS1_3_PSK_EXTERNAL, + hash_alg, psk, psk_len, + &output_len); + if (ret != 0) { + return ret; + } + p += output_len; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding PSK binder list.")); + + /* + * - binders_len (2 bytes) + */ + MBEDTLS_PUT_UINT16_BE(p - buf - 2, buf, 0); + + MBEDTLS_SSL_DEBUG_BUF(3, "pre_shared_key binders", buf, p - buf); + + mbedtls_ssl_tls13_set_hs_sent_ext_mask( + ssl, MBEDTLS_TLS_EXT_PRE_SHARED_KEY); + + return 0; +} + +/* + * struct { + * opaque identity<1..2^16-1>; + * uint32 obfuscated_ticket_age; + * } PskIdentity; + * + * opaque PskBinderEntry<32..255>; + * + * struct { + * + * select (Handshake.msg_type) { + * ... + * case server_hello: uint16 selected_identity; + * }; + * + * } PreSharedKeyExtension; + * + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_parse_server_pre_shared_key_ext(mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + int selected_identity; + const unsigned char *psk; + size_t psk_len; + psa_algorithm_t hash_alg; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(buf, end, 2); + selected_identity = MBEDTLS_GET_UINT16_BE(buf, 0); + ssl->handshake->selected_identity = (uint16_t) selected_identity; + + MBEDTLS_SSL_DEBUG_MSG(3, ("selected_identity = %d", selected_identity)); + + if (selected_identity >= ssl_tls13_get_configured_psk_count(ssl)) { + MBEDTLS_SSL_DEBUG_MSG(1, ("Invalid PSK identity.")); + + MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, + MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + +#if defined(MBEDTLS_SSL_SESSION_TICKETS) + if (selected_identity == 0 && ssl_tls13_has_configured_ticket(ssl)) { + ret = ssl_tls13_ticket_get_psk(ssl, &hash_alg, &psk, &psk_len); + } else +#endif + if (mbedtls_ssl_conf_has_static_psk(ssl->conf)) { + ret = ssl_tls13_psk_get_psk(ssl, &hash_alg, &psk, &psk_len); + } else { + MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + if (ret != 0) { + return ret; + } + + if (mbedtls_md_psa_alg_from_type((mbedtls_md_type_t) ssl->handshake->ciphersuite_info->mac) + != hash_alg) { + MBEDTLS_SSL_DEBUG_MSG( + 1, ("Invalid ciphersuite for external psk.")); + + MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, + MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + + ret = mbedtls_ssl_set_hs_psk(ssl, psk, psk_len); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_set_hs_psk", ret); + return ret; + } + + return 0; +} +#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */ + +int mbedtls_ssl_tls13_write_client_hello_exts(mbedtls_ssl_context *ssl, + unsigned char *buf, + unsigned char *end, + size_t *out_len) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + unsigned char *p = buf; + size_t ext_len; + + *out_len = 0; + + /* Write supported_versions extension + * + * Supported Versions Extension is mandatory with TLS 1.3. + */ + ret = ssl_tls13_write_supported_versions_ext(ssl, p, end, &ext_len); + if (ret != 0) { + return ret; + } + p += ext_len; + + /* Echo the cookie if the server provided one in its preceding + * HelloRetryRequest message. + */ + ret = ssl_tls13_write_cookie_ext(ssl, p, end, &ext_len); + if (ret != 0) { + return ret; + } + p += ext_len; + +#if defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT) + ret = mbedtls_ssl_tls13_write_record_size_limit_ext( + ssl, p, end, &ext_len); + if (ret != 0) { + return ret; + } + p += ext_len; +#endif + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_EPHEMERAL_ENABLED) + if (mbedtls_ssl_conf_tls13_is_some_ephemeral_enabled(ssl)) { + ret = ssl_tls13_write_key_share_ext(ssl, p, end, &ext_len); + if (ret != 0) { + return ret; + } + p += ext_len; + } +#endif + +#if defined(MBEDTLS_SSL_EARLY_DATA) + /* In the first ClientHello, write the early data indication extension if + * necessary and update the early data state. + * If an HRR has been received and thus we are currently writing the + * second ClientHello, the second ClientHello must not contain an early + * data extension and the early data state must stay as it is: + * MBEDTLS_SSL_EARLY_DATA_STATE_NO_IND_SENT or + * MBEDTLS_SSL_EARLY_DATA_STATE_REJECTED. + */ + if (!ssl->handshake->hello_retry_request_flag) { + if (mbedtls_ssl_conf_tls13_is_some_psk_enabled(ssl) && + ssl_tls13_early_data_has_valid_ticket(ssl) && + ssl->conf->early_data_enabled == MBEDTLS_SSL_EARLY_DATA_ENABLED) { + ret = mbedtls_ssl_tls13_write_early_data_ext( + ssl, 0, p, end, &ext_len); + if (ret != 0) { + return ret; + } + p += ext_len; + + ssl->early_data_state = MBEDTLS_SSL_EARLY_DATA_STATE_IND_SENT; + } else { + ssl->early_data_state = MBEDTLS_SSL_EARLY_DATA_STATE_NO_IND_SENT; + } + } +#endif /* MBEDTLS_SSL_EARLY_DATA */ + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) + /* For PSK-based key exchange we need the pre_shared_key extension + * and the psk_key_exchange_modes extension. + * + * The pre_shared_key extension MUST be the last extension in the + * ClientHello. Servers MUST check that it is the last extension and + * otherwise fail the handshake with an "illegal_parameter" alert. + * + * Add the psk_key_exchange_modes extension. + */ + ret = ssl_tls13_write_psk_key_exchange_modes_ext(ssl, p, end, &ext_len); + if (ret != 0) { + return ret; + } + p += ext_len; +#endif + + *out_len = p - buf; + + return 0; +} + +int mbedtls_ssl_tls13_finalize_client_hello(mbedtls_ssl_context *ssl) +{ + ((void) ssl); + +#if defined(MBEDTLS_SSL_EARLY_DATA) + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + psa_algorithm_t hash_alg = PSA_ALG_NONE; + const unsigned char *psk; + size_t psk_len; + const mbedtls_ssl_ciphersuite_t *ciphersuite_info; + + if (ssl->early_data_state == MBEDTLS_SSL_EARLY_DATA_STATE_IND_SENT) { + MBEDTLS_SSL_DEBUG_MSG( + 1, ("Set hs psk for early data when writing the first psk")); + + ret = ssl_tls13_ticket_get_psk(ssl, &hash_alg, &psk, &psk_len); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET( + 1, "ssl_tls13_ticket_get_psk", ret); + return ret; + } + + ret = mbedtls_ssl_set_hs_psk(ssl, psk, psk_len); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_set_hs_psk", ret); + return ret; + } + + /* + * Early data are going to be encrypted using the ciphersuite + * associated with the pre-shared key used for the handshake. + * Note that if the server rejects early data, the handshake + * based on the pre-shared key may complete successfully + * with a selected ciphersuite different from the ciphersuite + * associated with the pre-shared key. Only the hashes of the + * two ciphersuites have to be the same. In that case, the + * encrypted handshake data and application data are + * encrypted using a different ciphersuite than the one used for + * the rejected early data. + */ + ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( + ssl->session_negotiate->ciphersuite); + ssl->handshake->ciphersuite_info = ciphersuite_info; + + /* Enable psk and psk_ephemeral to make stage early happy */ + ssl->handshake->key_exchange_mode = + MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ALL; + + /* Start the TLS 1.3 key schedule: + * Set the PSK and derive early secret. + */ + ret = mbedtls_ssl_tls13_key_schedule_stage_early(ssl); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET( + 1, "mbedtls_ssl_tls13_key_schedule_stage_early", ret); + return ret; + } + + /* Derive early data key material */ + ret = mbedtls_ssl_tls13_compute_early_transform(ssl); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET( + 1, "mbedtls_ssl_tls13_compute_early_transform", ret); + return ret; + } + +#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE) + mbedtls_ssl_handshake_set_state( + ssl, MBEDTLS_SSL_CLIENT_CCS_AFTER_CLIENT_HELLO); +#else + MBEDTLS_SSL_DEBUG_MSG( + 1, ("Switch to early data keys for outbound traffic")); + mbedtls_ssl_set_outbound_transform( + ssl, ssl->handshake->transform_earlydata); + ssl->early_data_state = MBEDTLS_SSL_EARLY_DATA_STATE_CAN_WRITE; +#endif + } +#endif /* MBEDTLS_SSL_EARLY_DATA */ + return 0; +} +/* + * Functions for parsing and processing Server Hello + */ + +/** + * \brief Detect if the ServerHello contains a supported_versions extension + * or not. + * + * \param[in] ssl SSL context + * \param[in] buf Buffer containing the ServerHello message + * \param[in] end End of the buffer containing the ServerHello message + * + * \return 0 if the ServerHello does not contain a supported_versions extension + * \return 1 if the ServerHello contains a supported_versions extension + * \return A negative value if an error occurred while parsing the ServerHello. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_is_supported_versions_ext_present( + mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end) +{ + const unsigned char *p = buf; + size_t legacy_session_id_echo_len; + const unsigned char *supported_versions_data; + const unsigned char *supported_versions_data_end; + + /* + * Check there is enough data to access the legacy_session_id_echo vector + * length: + * - legacy_version 2 bytes + * - random MBEDTLS_SERVER_HELLO_RANDOM_LEN bytes + * - legacy_session_id_echo length 1 byte + */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, MBEDTLS_SERVER_HELLO_RANDOM_LEN + 3); + p += MBEDTLS_SERVER_HELLO_RANDOM_LEN + 2; + legacy_session_id_echo_len = *p; + + /* + * Jump to the extensions, jumping over: + * - legacy_session_id_echo (legacy_session_id_echo_len + 1) bytes + * - cipher_suite 2 bytes + * - legacy_compression_method 1 byte + */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, legacy_session_id_echo_len + 4); + p += legacy_session_id_echo_len + 4; + + return mbedtls_ssl_tls13_is_supported_versions_ext_present_in_exts( + ssl, p, end, + &supported_versions_data, &supported_versions_data_end); +} + +/* Returns a negative value on failure, and otherwise + * - 1 if the last eight bytes of the ServerHello random bytes indicate that + * the server is TLS 1.3 capable but negotiating TLS 1.2 or below. + * - 0 otherwise + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_is_downgrade_negotiation(mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end) +{ + /* First seven bytes of the magic downgrade strings, see RFC 8446 4.1.3 */ + static const unsigned char magic_downgrade_string[] = + { 0x44, 0x4F, 0x57, 0x4E, 0x47, 0x52, 0x44 }; + const unsigned char *last_eight_bytes_of_random; + unsigned char last_byte_of_random; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(buf, end, MBEDTLS_SERVER_HELLO_RANDOM_LEN + 2); + last_eight_bytes_of_random = buf + 2 + MBEDTLS_SERVER_HELLO_RANDOM_LEN - 8; + + if (memcmp(last_eight_bytes_of_random, + magic_downgrade_string, + sizeof(magic_downgrade_string)) == 0) { + last_byte_of_random = last_eight_bytes_of_random[7]; + return last_byte_of_random == 0 || + last_byte_of_random == 1; + } + + return 0; +} + +/* Returns a negative value on failure, and otherwise + * - SSL_SERVER_HELLO or + * - SSL_SERVER_HELLO_HRR + * to indicate which message is expected and to be parsed next. + */ +#define SSL_SERVER_HELLO 0 +#define SSL_SERVER_HELLO_HRR 1 +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_server_hello_is_hrr(mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end) +{ + + /* Check whether this message is a HelloRetryRequest ( HRR ) message. + * + * Server Hello and HRR are only distinguished by Random set to the + * special value of the SHA-256 of "HelloRetryRequest". + * + * struct { + * ProtocolVersion legacy_version = 0x0303; + * Random random; + * opaque legacy_session_id_echo<0..32>; + * CipherSuite cipher_suite; + * uint8 legacy_compression_method = 0; + * Extension extensions<6..2^16-1>; + * } ServerHello; + * + */ + MBEDTLS_SSL_CHK_BUF_READ_PTR( + buf, end, 2 + sizeof(mbedtls_ssl_tls13_hello_retry_request_magic)); + + if (memcmp(buf + 2, mbedtls_ssl_tls13_hello_retry_request_magic, + sizeof(mbedtls_ssl_tls13_hello_retry_request_magic)) == 0) { + return SSL_SERVER_HELLO_HRR; + } + + return SSL_SERVER_HELLO; +} + +/* + * Returns a negative value on failure, and otherwise + * - SSL_SERVER_HELLO or + * - SSL_SERVER_HELLO_HRR or + * - SSL_SERVER_HELLO_TLS1_2 + */ +#define SSL_SERVER_HELLO_TLS1_2 2 +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_preprocess_server_hello(mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + mbedtls_ssl_handshake_params *handshake = ssl->handshake; + + MBEDTLS_SSL_PROC_CHK_NEG(ssl_tls13_is_supported_versions_ext_present( + ssl, buf, end)); + + if (ret == 0) { + MBEDTLS_SSL_PROC_CHK_NEG( + ssl_tls13_is_downgrade_negotiation(ssl, buf, end)); + + /* If the server is negotiating TLS 1.2 or below and: + * . we did not propose TLS 1.2 or + * . the server responded it is TLS 1.3 capable but negotiating a lower + * version of the protocol and thus we are under downgrade attack + * abort the handshake with an "illegal parameter" alert. + */ + if (handshake->min_tls_version > MBEDTLS_SSL_VERSION_TLS1_2 || ret) { + MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, + MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + + /* + * Version 1.2 of the protocol has been negotiated, set the + * ssl->keep_current_message flag for the ServerHello to be kept and + * parsed as a TLS 1.2 ServerHello. We also change ssl->tls_version to + * MBEDTLS_SSL_VERSION_TLS1_2 thus from now on mbedtls_ssl_handshake_step() + * will dispatch to the TLS 1.2 state machine. + */ + ssl->keep_current_message = 1; + ssl->tls_version = MBEDTLS_SSL_VERSION_TLS1_2; + MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_add_hs_msg_to_checksum( + ssl, MBEDTLS_SSL_HS_SERVER_HELLO, + buf, (size_t) (end - buf))); + + if (mbedtls_ssl_conf_tls13_is_some_ephemeral_enabled(ssl)) { + ret = ssl_tls13_reset_key_share(ssl); + if (ret != 0) { + return ret; + } + } + + return SSL_SERVER_HELLO_TLS1_2; + } + + ssl->session_negotiate->tls_version = ssl->tls_version; + ssl->session_negotiate->endpoint = ssl->conf->endpoint; + + handshake->received_extensions = MBEDTLS_SSL_EXT_MASK_NONE; + + ret = ssl_server_hello_is_hrr(ssl, buf, end); + switch (ret) { + case SSL_SERVER_HELLO: + MBEDTLS_SSL_DEBUG_MSG(2, ("received ServerHello message")); + break; + case SSL_SERVER_HELLO_HRR: + MBEDTLS_SSL_DEBUG_MSG(2, ("received HelloRetryRequest message")); + /* If a client receives a second HelloRetryRequest in the same + * connection (i.e., where the ClientHello was itself in response + * to a HelloRetryRequest), it MUST abort the handshake with an + * "unexpected_message" alert. + */ + if (handshake->hello_retry_request_flag) { + MBEDTLS_SSL_DEBUG_MSG(1, ("Multiple HRRs received")); + MBEDTLS_SSL_PEND_FATAL_ALERT( + MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE, + MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE); + return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; + } + /* + * Clients must abort the handshake with an "illegal_parameter" + * alert if the HelloRetryRequest would not result in any change + * in the ClientHello. + * In a PSK only key exchange that what we expect. + */ + if (!mbedtls_ssl_conf_tls13_is_some_ephemeral_enabled(ssl)) { + MBEDTLS_SSL_DEBUG_MSG(1, + ("Unexpected HRR in pure PSK key exchange.")); + MBEDTLS_SSL_PEND_FATAL_ALERT( + MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, + MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + + handshake->hello_retry_request_flag = 1; + + break; + } + +cleanup: + + return ret; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_check_server_hello_session_id_echo(mbedtls_ssl_context *ssl, + const unsigned char **buf, + const unsigned char *end) +{ + const unsigned char *p = *buf; + size_t legacy_session_id_echo_len; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 1); + legacy_session_id_echo_len = *p++; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, legacy_session_id_echo_len); + + /* legacy_session_id_echo */ + if (ssl->session_negotiate->id_len != legacy_session_id_echo_len || + memcmp(ssl->session_negotiate->id, p, legacy_session_id_echo_len) != 0) { + MBEDTLS_SSL_DEBUG_BUF(3, "Expected Session ID", + ssl->session_negotiate->id, + ssl->session_negotiate->id_len); + MBEDTLS_SSL_DEBUG_BUF(3, "Received Session ID", p, + legacy_session_id_echo_len); + + MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, + MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); + + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + + p += legacy_session_id_echo_len; + *buf = p; + + MBEDTLS_SSL_DEBUG_BUF(3, "Session ID", ssl->session_negotiate->id, + ssl->session_negotiate->id_len); + return 0; +} + +/* Parse ServerHello message and configure context + * + * struct { + * ProtocolVersion legacy_version = 0x0303; // TLS 1.2 + * Random random; + * opaque legacy_session_id_echo<0..32>; + * CipherSuite cipher_suite; + * uint8 legacy_compression_method = 0; + * Extension extensions<6..2^16-1>; + * } ServerHello; + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_parse_server_hello(mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end, + int is_hrr) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + const unsigned char *p = buf; + mbedtls_ssl_handshake_params *handshake = ssl->handshake; + size_t extensions_len; + const unsigned char *extensions_end; + uint16_t cipher_suite; + const mbedtls_ssl_ciphersuite_t *ciphersuite_info; + int fatal_alert = 0; + uint32_t allowed_extensions_mask; + int hs_msg_type = is_hrr ? MBEDTLS_SSL_TLS1_3_HS_HELLO_RETRY_REQUEST : + MBEDTLS_SSL_HS_SERVER_HELLO; + + /* + * Check there is space for minimal fields + * + * - legacy_version ( 2 bytes) + * - random (MBEDTLS_SERVER_HELLO_RANDOM_LEN bytes) + * - legacy_session_id_echo ( 1 byte ), minimum size + * - cipher_suite ( 2 bytes) + * - legacy_compression_method ( 1 byte ) + */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, MBEDTLS_SERVER_HELLO_RANDOM_LEN + 6); + + MBEDTLS_SSL_DEBUG_BUF(4, "server hello", p, end - p); + MBEDTLS_SSL_DEBUG_BUF(3, "server hello, version", p, 2); + + /* ... + * ProtocolVersion legacy_version = 0x0303; // TLS 1.2 + * ... + * with ProtocolVersion defined as: + * uint16 ProtocolVersion; + */ + if (mbedtls_ssl_read_version(p, ssl->conf->transport) != + MBEDTLS_SSL_VERSION_TLS1_2) { + MBEDTLS_SSL_DEBUG_MSG(1, ("Unsupported version of TLS.")); + MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION, + MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION); + ret = MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION; + goto cleanup; + } + p += 2; + + /* ... + * Random random; + * ... + * with Random defined as: + * opaque Random[MBEDTLS_SERVER_HELLO_RANDOM_LEN]; + */ + if (!is_hrr) { + memcpy(&handshake->randbytes[MBEDTLS_CLIENT_HELLO_RANDOM_LEN], p, + MBEDTLS_SERVER_HELLO_RANDOM_LEN); + MBEDTLS_SSL_DEBUG_BUF(3, "server hello, random bytes", + p, MBEDTLS_SERVER_HELLO_RANDOM_LEN); + } + p += MBEDTLS_SERVER_HELLO_RANDOM_LEN; + + /* ... + * opaque legacy_session_id_echo<0..32>; + * ... + */ + if (ssl_tls13_check_server_hello_session_id_echo(ssl, &p, end) != 0) { + fatal_alert = MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER; + goto cleanup; + } + + /* ... + * CipherSuite cipher_suite; + * ... + * with CipherSuite defined as: + * uint8 CipherSuite[2]; + */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 2); + cipher_suite = MBEDTLS_GET_UINT16_BE(p, 0); + p += 2; + + + ciphersuite_info = mbedtls_ssl_ciphersuite_from_id(cipher_suite); + /* + * Check whether this ciphersuite is valid and offered. + */ + if ((mbedtls_ssl_validate_ciphersuite(ssl, ciphersuite_info, + ssl->tls_version, + ssl->tls_version) != 0) || + !mbedtls_ssl_tls13_cipher_suite_is_offered(ssl, cipher_suite)) { + fatal_alert = MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER; + } + /* + * If we received an HRR before and that the proposed selected + * ciphersuite in this server hello is not the same as the one + * proposed in the HRR, we abort the handshake and send an + * "illegal_parameter" alert. + */ + else if ((!is_hrr) && handshake->hello_retry_request_flag && + (cipher_suite != ssl->session_negotiate->ciphersuite)) { + fatal_alert = MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER; + } + + if (fatal_alert == MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER) { + MBEDTLS_SSL_DEBUG_MSG(1, ("invalid ciphersuite(%04x) parameter", + cipher_suite)); + goto cleanup; + } + + /* Configure ciphersuites */ + mbedtls_ssl_optimize_checksum(ssl, ciphersuite_info); + + handshake->ciphersuite_info = ciphersuite_info; + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, chosen ciphersuite: ( %04x ) - %s", + cipher_suite, ciphersuite_info->name)); + +#if defined(MBEDTLS_HAVE_TIME) + ssl->session_negotiate->start = mbedtls_time(NULL); +#endif /* MBEDTLS_HAVE_TIME */ + + /* ... + * uint8 legacy_compression_method = 0; + * ... + */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 1); + if (p[0] != MBEDTLS_SSL_COMPRESS_NULL) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad legacy compression method")); + fatal_alert = MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER; + goto cleanup; + } + p++; + + /* ... + * Extension extensions<6..2^16-1>; + * ... + * struct { + * ExtensionType extension_type; (2 bytes) + * opaque extension_data<0..2^16-1>; + * } Extension; + */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 2); + extensions_len = MBEDTLS_GET_UINT16_BE(p, 0); + p += 2; + + /* Check extensions do not go beyond the buffer of data. */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, extensions_len); + extensions_end = p + extensions_len; + + MBEDTLS_SSL_DEBUG_BUF(3, "server hello extensions", p, extensions_len); + + handshake->received_extensions = MBEDTLS_SSL_EXT_MASK_NONE; + allowed_extensions_mask = is_hrr ? + MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_HRR : + MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_SH; + + while (p < extensions_end) { + unsigned int extension_type; + size_t extension_data_len; + const unsigned char *extension_data_end; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, extensions_end, 4); + extension_type = MBEDTLS_GET_UINT16_BE(p, 0); + extension_data_len = MBEDTLS_GET_UINT16_BE(p, 2); + p += 4; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, extensions_end, extension_data_len); + extension_data_end = p + extension_data_len; + + ret = mbedtls_ssl_tls13_check_received_extension( + ssl, hs_msg_type, extension_type, allowed_extensions_mask); + if (ret != 0) { + return ret; + } + + switch (extension_type) { + case MBEDTLS_TLS_EXT_COOKIE: + + ret = ssl_tls13_parse_cookie_ext(ssl, + p, extension_data_end); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, + "ssl_tls13_parse_cookie_ext", + ret); + goto cleanup; + } + break; + + case MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS: + ret = ssl_tls13_parse_supported_versions_ext(ssl, + p, + extension_data_end); + if (ret != 0) { + goto cleanup; + } + break; + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) + case MBEDTLS_TLS_EXT_PRE_SHARED_KEY: + MBEDTLS_SSL_DEBUG_MSG(3, ("found pre_shared_key extension")); + + if ((ret = ssl_tls13_parse_server_pre_shared_key_ext( + ssl, p, extension_data_end)) != 0) { + MBEDTLS_SSL_DEBUG_RET( + 1, ("ssl_tls13_parse_server_pre_shared_key_ext"), ret); + return ret; + } + break; +#endif + + case MBEDTLS_TLS_EXT_KEY_SHARE: + MBEDTLS_SSL_DEBUG_MSG(3, ("found key_shares extension")); + if (!mbedtls_ssl_conf_tls13_is_some_ephemeral_enabled(ssl)) { + fatal_alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT; + goto cleanup; + } + + if (is_hrr) { + ret = ssl_tls13_parse_hrr_key_share_ext(ssl, + p, extension_data_end); + } else { + ret = ssl_tls13_parse_key_share_ext(ssl, + p, extension_data_end); + } + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, + "ssl_tls13_parse_key_share_ext", + ret); + goto cleanup; + } + break; + + default: + ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR; + goto cleanup; + } + + p += extension_data_len; + } + + MBEDTLS_SSL_PRINT_EXTS(3, hs_msg_type, handshake->received_extensions); + +cleanup: + + if (fatal_alert == MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT) { + MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT, + MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION); + ret = MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION; + } else if (fatal_alert == MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER) { + MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, + MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); + ret = MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + return ret; +} + +#if defined(MBEDTLS_DEBUG_C) +static const char *ssl_tls13_get_kex_mode_str(int mode) +{ + switch (mode) { + case MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK: + return "psk"; + case MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL: + return "ephemeral"; + case MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL: + return "psk_ephemeral"; + default: + return "unknown mode"; + } +} +#endif /* MBEDTLS_DEBUG_C */ + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_postprocess_server_hello(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + mbedtls_ssl_handshake_params *handshake = ssl->handshake; + + /* Determine the key exchange mode: + * 1) If both the pre_shared_key and key_share extensions were received + * then the key exchange mode is PSK with EPHEMERAL. + * 2) If only the pre_shared_key extension was received then the key + * exchange mode is PSK-only. + * 3) If only the key_share extension was received then the key + * exchange mode is EPHEMERAL-only. + */ + switch (handshake->received_extensions & + (MBEDTLS_SSL_EXT_MASK(PRE_SHARED_KEY) | + MBEDTLS_SSL_EXT_MASK(KEY_SHARE))) { + /* Only the pre_shared_key extension was received */ + case MBEDTLS_SSL_EXT_MASK(PRE_SHARED_KEY): + handshake->key_exchange_mode = + MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK; + break; + + /* Only the key_share extension was received */ + case MBEDTLS_SSL_EXT_MASK(KEY_SHARE): + handshake->key_exchange_mode = + MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL; + break; + + /* Both the pre_shared_key and key_share extensions were received */ + case (MBEDTLS_SSL_EXT_MASK(PRE_SHARED_KEY) | + MBEDTLS_SSL_EXT_MASK(KEY_SHARE)): + handshake->key_exchange_mode = + MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL; + break; + + /* Neither pre_shared_key nor key_share extension was received */ + default: + MBEDTLS_SSL_DEBUG_MSG(1, ("Unknown key exchange.")); + ret = MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; + goto cleanup; + } + + if (!mbedtls_ssl_conf_tls13_is_kex_mode_enabled( + ssl, handshake->key_exchange_mode)) { + ret = MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; + MBEDTLS_SSL_DEBUG_MSG( + 2, ("Key exchange mode(%s) is not supported.", + ssl_tls13_get_kex_mode_str(handshake->key_exchange_mode))); + goto cleanup; + } + + MBEDTLS_SSL_DEBUG_MSG( + 3, ("Selected key exchange mode: %s", + ssl_tls13_get_kex_mode_str(handshake->key_exchange_mode))); + + /* Start the TLS 1.3 key scheduling if not already done. + * + * If we proposed early data then we have already derived an + * early secret using the selected PSK and its associated hash. + * It means that if the negotiated key exchange mode is psk or + * psk_ephemeral, we have already correctly computed the + * early secret and thus we do not do it again. In all other + * cases we compute it here. + */ +#if defined(MBEDTLS_SSL_EARLY_DATA) + if (ssl->early_data_state == MBEDTLS_SSL_EARLY_DATA_STATE_NO_IND_SENT || + handshake->key_exchange_mode == + MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL) +#endif + { + ret = mbedtls_ssl_tls13_key_schedule_stage_early(ssl); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET( + 1, "mbedtls_ssl_tls13_key_schedule_stage_early", ret); + goto cleanup; + } + } + + ret = mbedtls_ssl_tls13_compute_handshake_transform(ssl); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, + "mbedtls_ssl_tls13_compute_handshake_transform", + ret); + goto cleanup; + } + + mbedtls_ssl_set_inbound_transform(ssl, handshake->transform_handshake); + MBEDTLS_SSL_DEBUG_MSG(1, ("Switch to handshake keys for inbound traffic")); + ssl->session_in = ssl->session_negotiate; + +cleanup: + if (ret != 0) { + MBEDTLS_SSL_PEND_FATAL_ALERT( + MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE, + MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE); + } + + return ret; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_postprocess_hrr(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + + mbedtls_ssl_session_reset_msg_layer(ssl, 0); + + /* + * We are going to re-generate a shared secret corresponding to the group + * selected by the server, which is different from the group for which we + * generated a shared secret in the first client hello. + * Thus, reset the shared secret. + */ + ret = ssl_tls13_reset_key_share(ssl); + if (ret != 0) { + return ret; + } + + ssl->session_negotiate->ciphersuite = ssl->handshake->ciphersuite_info->id; + +#if defined(MBEDTLS_SSL_EARLY_DATA) + if (ssl->early_data_state != MBEDTLS_SSL_EARLY_DATA_STATE_NO_IND_SENT) { + ssl->early_data_state = MBEDTLS_SSL_EARLY_DATA_STATE_REJECTED; + } +#endif + + return 0; +} + +/* + * Wait and parse ServerHello handshake message. + * Handler for MBEDTLS_SSL_SERVER_HELLO + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_process_server_hello(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + unsigned char *buf = NULL; + size_t buf_len = 0; + int is_hrr = 0; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> %s", __func__)); + + MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_tls13_fetch_handshake_msg( + ssl, MBEDTLS_SSL_HS_SERVER_HELLO, &buf, &buf_len)); + + ret = ssl_tls13_preprocess_server_hello(ssl, buf, buf + buf_len); + if (ret < 0) { + goto cleanup; + } else { + is_hrr = (ret == SSL_SERVER_HELLO_HRR); + } + + if (ret == SSL_SERVER_HELLO_TLS1_2) { + ret = 0; + goto cleanup; + } + + MBEDTLS_SSL_PROC_CHK(ssl_tls13_parse_server_hello(ssl, buf, + buf + buf_len, + is_hrr)); + if (is_hrr) { + MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_reset_transcript_for_hrr(ssl)); + } + + MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_add_hs_msg_to_checksum( + ssl, MBEDTLS_SSL_HS_SERVER_HELLO, buf, buf_len)); + + if (is_hrr) { + MBEDTLS_SSL_PROC_CHK(ssl_tls13_postprocess_hrr(ssl)); +#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE) + /* If not offering early data, the client sends a dummy CCS record + * immediately before its second flight. This may either be before + * its second ClientHello or before its encrypted handshake flight. + */ + mbedtls_ssl_handshake_set_state( + ssl, MBEDTLS_SSL_CLIENT_CCS_BEFORE_2ND_CLIENT_HELLO); +#else + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_HELLO); +#endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */ + } else { + MBEDTLS_SSL_PROC_CHK(ssl_tls13_postprocess_server_hello(ssl)); + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_ENCRYPTED_EXTENSIONS); + } + +cleanup: + MBEDTLS_SSL_DEBUG_MSG(2, ("<= %s ( %s )", __func__, + is_hrr ? "HelloRetryRequest" : "ServerHello")); + return ret; +} + +/* + * + * Handler for MBEDTLS_SSL_ENCRYPTED_EXTENSIONS + * + * The EncryptedExtensions message contains any extensions which + * should be protected, i.e., any which are not needed to establish + * the cryptographic context. + */ + +/* Parse EncryptedExtensions message + * struct { + * Extension extensions<0..2^16-1>; + * } EncryptedExtensions; + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_parse_encrypted_extensions(mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end) +{ + int ret = 0; + size_t extensions_len; + const unsigned char *p = buf; + const unsigned char *extensions_end; + mbedtls_ssl_handshake_params *handshake = ssl->handshake; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 2); + extensions_len = MBEDTLS_GET_UINT16_BE(p, 0); + p += 2; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, extensions_len); + extensions_end = p + extensions_len; + + MBEDTLS_SSL_DEBUG_BUF(3, "encrypted extensions", p, extensions_len); + + handshake->received_extensions = MBEDTLS_SSL_EXT_MASK_NONE; + + while (p < extensions_end) { + unsigned int extension_type; + size_t extension_data_len; + + /* + * struct { + * ExtensionType extension_type; (2 bytes) + * opaque extension_data<0..2^16-1>; + * } Extension; + */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, extensions_end, 4); + extension_type = MBEDTLS_GET_UINT16_BE(p, 0); + extension_data_len = MBEDTLS_GET_UINT16_BE(p, 2); + p += 4; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, extensions_end, extension_data_len); + + ret = mbedtls_ssl_tls13_check_received_extension( + ssl, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS, extension_type, + MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_EE); + if (ret != 0) { + return ret; + } + + switch (extension_type) { +#if defined(MBEDTLS_SSL_ALPN) + case MBEDTLS_TLS_EXT_ALPN: + MBEDTLS_SSL_DEBUG_MSG(3, ("found alpn extension")); + + if ((ret = ssl_tls13_parse_alpn_ext( + ssl, p, (size_t) extension_data_len)) != 0) { + return ret; + } + + break; +#endif /* MBEDTLS_SSL_ALPN */ + +#if defined(MBEDTLS_SSL_EARLY_DATA) + case MBEDTLS_TLS_EXT_EARLY_DATA: + + if (extension_data_len != 0) { + /* The message must be empty. */ + MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, + MBEDTLS_ERR_SSL_DECODE_ERROR); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + break; +#endif /* MBEDTLS_SSL_EARLY_DATA */ + +#if defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT) + case MBEDTLS_TLS_EXT_RECORD_SIZE_LIMIT: + MBEDTLS_SSL_DEBUG_MSG(3, ("found record_size_limit extension")); + + ret = mbedtls_ssl_tls13_parse_record_size_limit_ext( + ssl, p, p + extension_data_len); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET( + 1, ("mbedtls_ssl_tls13_parse_record_size_limit_ext"), ret); + return ret; + } + break; +#endif /* MBEDTLS_SSL_RECORD_SIZE_LIMIT */ + + default: + MBEDTLS_SSL_PRINT_EXT( + 3, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS, + extension_type, "( ignored )"); + break; + } + + p += extension_data_len; + } + + if ((handshake->received_extensions & MBEDTLS_SSL_EXT_MASK(RECORD_SIZE_LIMIT)) && + (handshake->received_extensions & MBEDTLS_SSL_EXT_MASK(MAX_FRAGMENT_LENGTH))) { + MBEDTLS_SSL_DEBUG_MSG(3, + ( + "Record size limit extension cannot be used with max fragment length extension")); + MBEDTLS_SSL_PEND_FATAL_ALERT( + MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, + MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + + MBEDTLS_SSL_PRINT_EXTS(3, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS, + handshake->received_extensions); + + /* Check that we consumed all the message. */ + if (p != end) { + MBEDTLS_SSL_DEBUG_MSG(1, ("EncryptedExtension lengths misaligned")); + MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, + MBEDTLS_ERR_SSL_DECODE_ERROR); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + return ret; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_process_encrypted_extensions(mbedtls_ssl_context *ssl) +{ + int ret; + unsigned char *buf; + size_t buf_len; + mbedtls_ssl_handshake_params *handshake = ssl->handshake; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse encrypted extensions")); + + MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_tls13_fetch_handshake_msg( + ssl, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS, + &buf, &buf_len)); + + /* Process the message contents */ + MBEDTLS_SSL_PROC_CHK( + ssl_tls13_parse_encrypted_extensions(ssl, buf, buf + buf_len)); + +#if defined(MBEDTLS_SSL_EARLY_DATA) + if (handshake->received_extensions & MBEDTLS_SSL_EXT_MASK(EARLY_DATA)) { + /* RFC8446 4.2.11 + * If the server supplies an "early_data" extension, the + * client MUST verify that the server's selected_identity + * is 0. If any other value is returned, the client MUST + * abort the handshake with an "illegal_parameter" alert. + * + * RFC 8446 4.2.10 + * In order to accept early data, the server MUST have accepted a PSK + * cipher suite and selected the first key offered in the client's + * "pre_shared_key" extension. In addition, it MUST verify that the + * following values are the same as those associated with the + * selected PSK: + * - The TLS version number + * - The selected cipher suite + * - The selected ALPN [RFC7301] protocol, if any + * + * The server has sent an early data extension in its Encrypted + * Extension message thus accepted to receive early data. We + * check here that the additional constraints on the handshake + * parameters, when early data are exchanged, are met, + * namely: + * - a PSK has been selected for the handshake + * - the selected PSK for the handshake was the first one proposed + * by the client. + * - the selected ciphersuite for the handshake is the ciphersuite + * associated with the selected PSK. + */ + if ((!mbedtls_ssl_tls13_key_exchange_mode_with_psk(ssl)) || + handshake->selected_identity != 0 || + handshake->ciphersuite_info->id != + ssl->session_negotiate->ciphersuite) { + + MBEDTLS_SSL_PEND_FATAL_ALERT( + MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, + MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + + ssl->early_data_state = MBEDTLS_SSL_EARLY_DATA_STATE_ACCEPTED; + } else if (ssl->early_data_state != + MBEDTLS_SSL_EARLY_DATA_STATE_NO_IND_SENT) { + ssl->early_data_state = MBEDTLS_SSL_EARLY_DATA_STATE_REJECTED; + } +#endif + + /* + * In case the client has proposed a PSK associated with a ticket, + * `ssl->session_negotiate->ciphersuite` still contains at this point the + * identifier of the ciphersuite associated with the ticket. This is that + * way because, if an exchange of early data is agreed upon, we need + * it to check that the ciphersuite selected for the handshake is the + * ticket ciphersuite (see above). This information is not needed + * anymore thus we can now set it to the identifier of the ciphersuite + * used in this session under negotiation. + */ + ssl->session_negotiate->ciphersuite = handshake->ciphersuite_info->id; + + MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_add_hs_msg_to_checksum( + ssl, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS, + buf, buf_len)); + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED) + if (mbedtls_ssl_tls13_key_exchange_mode_with_psk(ssl)) { + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_SERVER_FINISHED); + } else { + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CERTIFICATE_REQUEST); + } +#else + ((void) ssl); + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_SERVER_FINISHED); +#endif + +cleanup: + + MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse encrypted extensions")); + return ret; + +} + +#if defined(MBEDTLS_SSL_EARLY_DATA) +/* + * Handler for MBEDTLS_SSL_END_OF_EARLY_DATA + * + * RFC 8446 section 4.5 + * + * struct {} EndOfEarlyData; + * + * If the server sent an "early_data" extension in EncryptedExtensions, the + * client MUST send an EndOfEarlyData message after receiving the server + * Finished. Otherwise, the client MUST NOT send an EndOfEarlyData message. + */ + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_write_end_of_early_data(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + unsigned char *buf = NULL; + size_t buf_len; + MBEDTLS_SSL_DEBUG_MSG(2, ("=> write EndOfEarlyData")); + + MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_start_handshake_msg( + ssl, MBEDTLS_SSL_HS_END_OF_EARLY_DATA, + &buf, &buf_len)); + + MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_add_hs_hdr_to_checksum( + ssl, MBEDTLS_SSL_HS_END_OF_EARLY_DATA, 0)); + + MBEDTLS_SSL_PROC_CHK( + mbedtls_ssl_finish_handshake_msg(ssl, buf_len, 0)); + + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE); + +cleanup: + + MBEDTLS_SSL_DEBUG_MSG(2, ("<= write EndOfEarlyData")); + return ret; +} + +int mbedtls_ssl_get_early_data_status(mbedtls_ssl_context *ssl) +{ + if ((ssl->conf->endpoint != MBEDTLS_SSL_IS_CLIENT) || + (!mbedtls_ssl_is_handshake_over(ssl))) { + return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; + } + + switch (ssl->early_data_state) { + case MBEDTLS_SSL_EARLY_DATA_STATE_NO_IND_SENT: + return MBEDTLS_SSL_EARLY_DATA_STATUS_NOT_INDICATED; + break; + + case MBEDTLS_SSL_EARLY_DATA_STATE_REJECTED: + return MBEDTLS_SSL_EARLY_DATA_STATUS_REJECTED; + break; + + case MBEDTLS_SSL_EARLY_DATA_STATE_SERVER_FINISHED_RECEIVED: + return MBEDTLS_SSL_EARLY_DATA_STATUS_ACCEPTED; + break; + + default: + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } +} +#endif /* MBEDTLS_SSL_EARLY_DATA */ + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED) +/* + * STATE HANDLING: CertificateRequest + * + */ +#define SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST 0 +#define SSL_CERTIFICATE_REQUEST_SKIP 1 +/* Coordination: + * Deals with the ambiguity of not knowing if a CertificateRequest + * will be sent. Returns a negative code on failure, or + * - SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST + * - SSL_CERTIFICATE_REQUEST_SKIP + * indicating if a Certificate Request is expected or not. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_certificate_request_coordinate(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + + if ((ret = mbedtls_ssl_read_record(ssl, 0)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_read_record", ret); + return ret; + } + ssl->keep_current_message = 1; + + if ((ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE) && + (ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE_REQUEST)) { + MBEDTLS_SSL_DEBUG_MSG(3, ("got a certificate request")); + return SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("got no certificate request")); + + return SSL_CERTIFICATE_REQUEST_SKIP; +} + +/* + * ssl_tls13_parse_certificate_request() + * Parse certificate request + * struct { + * opaque certificate_request_context<0..2^8-1>; + * Extension extensions<2..2^16-1>; + * } CertificateRequest; + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_parse_certificate_request(mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + const unsigned char *p = buf; + size_t certificate_request_context_len = 0; + size_t extensions_len = 0; + const unsigned char *extensions_end; + mbedtls_ssl_handshake_params *handshake = ssl->handshake; + + /* ... + * opaque certificate_request_context<0..2^8-1> + * ... + */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 1); + certificate_request_context_len = (size_t) p[0]; + p += 1; + + if (certificate_request_context_len > 0) { + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, certificate_request_context_len); + MBEDTLS_SSL_DEBUG_BUF(3, "Certificate Request Context", + p, certificate_request_context_len); + + handshake->certificate_request_context = + mbedtls_calloc(1, certificate_request_context_len); + if (handshake->certificate_request_context == NULL) { + MBEDTLS_SSL_DEBUG_MSG(1, ("buffer too small")); + return MBEDTLS_ERR_SSL_ALLOC_FAILED; + } + memcpy(handshake->certificate_request_context, p, + certificate_request_context_len); + p += certificate_request_context_len; + } + + /* ... + * Extension extensions<2..2^16-1>; + * ... + */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 2); + extensions_len = MBEDTLS_GET_UINT16_BE(p, 0); + p += 2; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, extensions_len); + extensions_end = p + extensions_len; + + handshake->received_extensions = MBEDTLS_SSL_EXT_MASK_NONE; + + while (p < extensions_end) { + unsigned int extension_type; + size_t extension_data_len; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, extensions_end, 4); + extension_type = MBEDTLS_GET_UINT16_BE(p, 0); + extension_data_len = MBEDTLS_GET_UINT16_BE(p, 2); + p += 4; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, extensions_end, extension_data_len); + + ret = mbedtls_ssl_tls13_check_received_extension( + ssl, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, extension_type, + MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_CR); + if (ret != 0) { + return ret; + } + + switch (extension_type) { + case MBEDTLS_TLS_EXT_SIG_ALG: + MBEDTLS_SSL_DEBUG_MSG(3, + ("found signature algorithms extension")); + ret = mbedtls_ssl_parse_sig_alg_ext(ssl, p, + p + extension_data_len); + if (ret != 0) { + return ret; + } + + break; + + default: + MBEDTLS_SSL_PRINT_EXT( + 3, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, + extension_type, "( ignored )"); + break; + } + + p += extension_data_len; + } + + MBEDTLS_SSL_PRINT_EXTS(3, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, + handshake->received_extensions); + + /* Check that we consumed all the message. */ + if (p != end) { + MBEDTLS_SSL_DEBUG_MSG(1, + ("CertificateRequest misaligned")); + goto decode_error; + } + + /* RFC 8446 section 4.3.2 + * + * The "signature_algorithms" extension MUST be specified + */ + if ((handshake->received_extensions & MBEDTLS_SSL_EXT_MASK(SIG_ALG)) == 0) { + MBEDTLS_SSL_DEBUG_MSG(3, + ("no signature algorithms extension found")); + goto decode_error; + } + + ssl->handshake->client_auth = 1; + return 0; + +decode_error: + MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, + MBEDTLS_ERR_SSL_DECODE_ERROR); + return MBEDTLS_ERR_SSL_DECODE_ERROR; +} + +/* + * Handler for MBEDTLS_SSL_CERTIFICATE_REQUEST + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_process_certificate_request(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse certificate request")); + + MBEDTLS_SSL_PROC_CHK_NEG(ssl_tls13_certificate_request_coordinate(ssl)); + + if (ret == SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST) { + unsigned char *buf; + size_t buf_len; + + MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_tls13_fetch_handshake_msg( + ssl, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, + &buf, &buf_len)); + + MBEDTLS_SSL_PROC_CHK(ssl_tls13_parse_certificate_request( + ssl, buf, buf + buf_len)); + + MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_add_hs_msg_to_checksum( + ssl, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, + buf, buf_len)); + } else if (ret == SSL_CERTIFICATE_REQUEST_SKIP) { + ret = 0; + } else { + MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); + ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR; + goto cleanup; + } + + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_SERVER_CERTIFICATE); + +cleanup: + + MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse certificate request")); + return ret; +} + +/* + * Handler for MBEDTLS_SSL_SERVER_CERTIFICATE + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_process_server_certificate(mbedtls_ssl_context *ssl) +{ + int ret; + + ret = mbedtls_ssl_tls13_process_certificate(ssl); + if (ret != 0) { + return ret; + } + + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CERTIFICATE_VERIFY); + return 0; +} + +/* + * Handler for MBEDTLS_SSL_CERTIFICATE_VERIFY + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_process_certificate_verify(mbedtls_ssl_context *ssl) +{ + int ret; + + ret = mbedtls_ssl_tls13_process_certificate_verify(ssl); + if (ret != 0) { + return ret; + } + + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_SERVER_FINISHED); + return 0; +} +#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED */ + +/* + * Handler for MBEDTLS_SSL_SERVER_FINISHED + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_process_server_finished(mbedtls_ssl_context *ssl) +{ + int ret; + + ret = mbedtls_ssl_tls13_process_finished_message(ssl); + if (ret != 0) { + return ret; + } + + ret = mbedtls_ssl_tls13_compute_application_transform(ssl); + if (ret != 0) { + MBEDTLS_SSL_PEND_FATAL_ALERT( + MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE, + MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE); + return ret; + } + +#if defined(MBEDTLS_SSL_EARLY_DATA) + if (ssl->early_data_state == MBEDTLS_SSL_EARLY_DATA_STATE_ACCEPTED) { + ssl->early_data_state = MBEDTLS_SSL_EARLY_DATA_STATE_SERVER_FINISHED_RECEIVED; + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_END_OF_EARLY_DATA); + } else +#endif /* MBEDTLS_SSL_EARLY_DATA */ + { +#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE) + mbedtls_ssl_handshake_set_state( + ssl, MBEDTLS_SSL_CLIENT_CCS_AFTER_SERVER_FINISHED); +#else + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE); +#endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */ + } + + return 0; +} + +/* + * Handler for MBEDTLS_SSL_CLIENT_CERTIFICATE + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_write_client_certificate(mbedtls_ssl_context *ssl) +{ + int non_empty_certificate_msg = 0; + + MBEDTLS_SSL_DEBUG_MSG(1, + ("Switch to handshake traffic keys for outbound traffic")); + mbedtls_ssl_set_outbound_transform(ssl, ssl->handshake->transform_handshake); + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED) + if (ssl->handshake->client_auth) { + int ret = mbedtls_ssl_tls13_write_certificate(ssl); + if (ret != 0) { + return ret; + } + + if (mbedtls_ssl_own_cert(ssl) != NULL) { + non_empty_certificate_msg = 1; + } + } else { + MBEDTLS_SSL_DEBUG_MSG(2, ("skip write certificate")); + } +#endif + + if (non_empty_certificate_msg) { + mbedtls_ssl_handshake_set_state(ssl, + MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY); + } else { + MBEDTLS_SSL_DEBUG_MSG(2, ("skip write certificate verify")); + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_FINISHED); + } + + return 0; +} + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED) +/* + * Handler for MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_write_client_certificate_verify(mbedtls_ssl_context *ssl) +{ + int ret = mbedtls_ssl_tls13_write_certificate_verify(ssl); + + if (ret == 0) { + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_FINISHED); + } + + return ret; +} +#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED */ + +/* + * Handler for MBEDTLS_SSL_CLIENT_FINISHED + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_write_client_finished(mbedtls_ssl_context *ssl) +{ + int ret; + + ret = mbedtls_ssl_tls13_write_finished_message(ssl); + if (ret != 0) { + return ret; + } + + ret = mbedtls_ssl_tls13_compute_resumption_master_secret(ssl); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET( + 1, "mbedtls_ssl_tls13_compute_resumption_master_secret ", ret); + return ret; + } + + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_FLUSH_BUFFERS); + return 0; +} + +/* + * Handler for MBEDTLS_SSL_FLUSH_BUFFERS + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_flush_buffers(mbedtls_ssl_context *ssl) +{ + MBEDTLS_SSL_DEBUG_MSG(2, ("handshake: done")); + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_HANDSHAKE_WRAPUP); + return 0; +} + +/* + * Handler for MBEDTLS_SSL_HANDSHAKE_WRAPUP + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_handshake_wrapup(mbedtls_ssl_context *ssl) +{ + + mbedtls_ssl_tls13_handshake_wrapup(ssl); + + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_HANDSHAKE_OVER); + return 0; +} + +#if defined(MBEDTLS_SSL_SESSION_TICKETS) + +#if defined(MBEDTLS_SSL_EARLY_DATA) +/* From RFC 8446 section 4.2.10 + * + * struct { + * select (Handshake.msg_type) { + * case new_session_ticket: uint32 max_early_data_size; + * ... + * }; + * } EarlyDataIndication; + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_parse_new_session_ticket_early_data_ext( + mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end) +{ + mbedtls_ssl_session *session = ssl->session; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(buf, end, 4); + + session->max_early_data_size = MBEDTLS_GET_UINT32_BE(buf, 0); + mbedtls_ssl_tls13_session_set_ticket_flags( + session, MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_EARLY_DATA); + MBEDTLS_SSL_DEBUG_MSG( + 3, ("received max_early_data_size: %u", + (unsigned int) session->max_early_data_size)); + + return 0; +} +#endif /* MBEDTLS_SSL_EARLY_DATA */ + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_parse_new_session_ticket_exts(mbedtls_ssl_context *ssl, + const unsigned char *buf, + const unsigned char *end) +{ + mbedtls_ssl_handshake_params *handshake = ssl->handshake; + const unsigned char *p = buf; + + + handshake->received_extensions = MBEDTLS_SSL_EXT_MASK_NONE; + + while (p < end) { + unsigned int extension_type; + size_t extension_data_len; + int ret; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 4); + extension_type = MBEDTLS_GET_UINT16_BE(p, 0); + extension_data_len = MBEDTLS_GET_UINT16_BE(p, 2); + p += 4; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, extension_data_len); + + ret = mbedtls_ssl_tls13_check_received_extension( + ssl, MBEDTLS_SSL_HS_NEW_SESSION_TICKET, extension_type, + MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_NST); + if (ret != 0) { + return ret; + } + + switch (extension_type) { +#if defined(MBEDTLS_SSL_EARLY_DATA) + case MBEDTLS_TLS_EXT_EARLY_DATA: + ret = ssl_tls13_parse_new_session_ticket_early_data_ext( + ssl, p, p + extension_data_len); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET( + 1, "ssl_tls13_parse_new_session_ticket_early_data_ext", + ret); + } + break; +#endif /* MBEDTLS_SSL_EARLY_DATA */ + + default: + MBEDTLS_SSL_PRINT_EXT( + 3, MBEDTLS_SSL_HS_NEW_SESSION_TICKET, + extension_type, "( ignored )"); + break; + } + + p += extension_data_len; + } + + MBEDTLS_SSL_PRINT_EXTS(3, MBEDTLS_SSL_HS_NEW_SESSION_TICKET, + handshake->received_extensions); + + return 0; +} + +/* + * From RFC8446, page 74 + * + * struct { + * uint32 ticket_lifetime; + * uint32 ticket_age_add; + * opaque ticket_nonce<0..255>; + * opaque ticket<1..2^16-1>; + * Extension extensions<0..2^16-2>; + * } NewSessionTicket; + * + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_parse_new_session_ticket(mbedtls_ssl_context *ssl, + unsigned char *buf, + unsigned char *end, + unsigned char **ticket_nonce, + size_t *ticket_nonce_len) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + unsigned char *p = buf; + mbedtls_ssl_session *session = ssl->session; + size_t ticket_len; + unsigned char *ticket; + size_t extensions_len; + + *ticket_nonce = NULL; + *ticket_nonce_len = 0; + /* + * ticket_lifetime 4 bytes + * ticket_age_add 4 bytes + * ticket_nonce_len 1 byte + */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 9); + + session->ticket_lifetime = MBEDTLS_GET_UINT32_BE(p, 0); + MBEDTLS_SSL_DEBUG_MSG(3, + ("ticket_lifetime: %u", + (unsigned int) session->ticket_lifetime)); + if (session->ticket_lifetime > + MBEDTLS_SSL_TLS1_3_MAX_ALLOWED_TICKET_LIFETIME) { + MBEDTLS_SSL_DEBUG_MSG(3, ("ticket_lifetime exceeds 7 days.")); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + + session->ticket_age_add = MBEDTLS_GET_UINT32_BE(p, 4); + MBEDTLS_SSL_DEBUG_MSG(3, + ("ticket_age_add: %u", + (unsigned int) session->ticket_age_add)); + + *ticket_nonce_len = p[8]; + p += 9; + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, *ticket_nonce_len); + *ticket_nonce = p; + MBEDTLS_SSL_DEBUG_BUF(3, "ticket_nonce:", *ticket_nonce, *ticket_nonce_len); + p += *ticket_nonce_len; + + /* Ticket */ + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 2); + ticket_len = MBEDTLS_GET_UINT16_BE(p, 0); + p += 2; + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, ticket_len); + MBEDTLS_SSL_DEBUG_BUF(3, "received ticket", p, ticket_len); + + /* Check if we previously received a ticket already. */ + if (session->ticket != NULL || session->ticket_len > 0) { + mbedtls_free(session->ticket); + session->ticket = NULL; + session->ticket_len = 0; + } + + if ((ticket = mbedtls_calloc(1, ticket_len)) == NULL) { + MBEDTLS_SSL_DEBUG_MSG(1, ("ticket alloc failed")); + return MBEDTLS_ERR_SSL_ALLOC_FAILED; + } + memcpy(ticket, p, ticket_len); + p += ticket_len; + session->ticket = ticket; + session->ticket_len = ticket_len; + + /* Clear all flags in ticket_flags */ + mbedtls_ssl_tls13_session_clear_ticket_flags( + session, MBEDTLS_SSL_TLS1_3_TICKET_FLAGS_MASK); + + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 2); + extensions_len = MBEDTLS_GET_UINT16_BE(p, 0); + p += 2; + MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, extensions_len); + + MBEDTLS_SSL_DEBUG_BUF(3, "ticket extension", p, extensions_len); + + ret = ssl_tls13_parse_new_session_ticket_exts(ssl, p, p + extensions_len); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, + "ssl_tls13_parse_new_session_ticket_exts", + ret); + return ret; + } + + return 0; +} + +/* Non negative return values for ssl_tls13_postprocess_new_session_ticket(). + * - POSTPROCESS_NEW_SESSION_TICKET_SIGNAL, all good, we have to signal the + * application that a valid ticket has been received. + * - POSTPROCESS_NEW_SESSION_TICKET_DISCARD, no fatal error, we keep the + * connection alive but we do not signal the ticket to the application. + */ +#define POSTPROCESS_NEW_SESSION_TICKET_SIGNAL 0 +#define POSTPROCESS_NEW_SESSION_TICKET_DISCARD 1 +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_postprocess_new_session_ticket(mbedtls_ssl_context *ssl, + unsigned char *ticket_nonce, + size_t ticket_nonce_len) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + mbedtls_ssl_session *session = ssl->session; + const mbedtls_ssl_ciphersuite_t *ciphersuite_info; + psa_algorithm_t psa_hash_alg; + int hash_length; + + if (session->ticket_lifetime == 0) { + return POSTPROCESS_NEW_SESSION_TICKET_DISCARD; + } + +#if defined(MBEDTLS_HAVE_TIME) + /* Store ticket creation time */ + session->ticket_reception_time = mbedtls_ms_time(); +#endif + + ciphersuite_info = mbedtls_ssl_ciphersuite_from_id(session->ciphersuite); + if (ciphersuite_info == NULL) { + MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + + psa_hash_alg = mbedtls_md_psa_alg_from_type((mbedtls_md_type_t) ciphersuite_info->mac); + hash_length = PSA_HASH_LENGTH(psa_hash_alg); + if (hash_length == -1 || + (size_t) hash_length > sizeof(session->resumption_key)) { + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + + + MBEDTLS_SSL_DEBUG_BUF(3, "resumption_master_secret", + session->app_secrets.resumption_master_secret, + hash_length); + + /* Compute resumption key + * + * HKDF-Expand-Label( resumption_master_secret, + * "resumption", ticket_nonce, Hash.length ) + */ + ret = mbedtls_ssl_tls13_hkdf_expand_label( + psa_hash_alg, + session->app_secrets.resumption_master_secret, + hash_length, + MBEDTLS_SSL_TLS1_3_LBL_WITH_LEN(resumption), + ticket_nonce, + ticket_nonce_len, + session->resumption_key, + hash_length); + + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(2, + "Creating the ticket-resumed PSK failed", + ret); + return ret; + } + + session->resumption_key_len = hash_length; + + MBEDTLS_SSL_DEBUG_BUF(3, "Ticket-resumed PSK", + session->resumption_key, + session->resumption_key_len); + + /* Set ticket_flags depends on the selected key exchange modes */ + mbedtls_ssl_tls13_session_set_ticket_flags( + session, ssl->conf->tls13_kex_modes); + MBEDTLS_SSL_PRINT_TICKET_FLAGS(4, session->ticket_flags); + + return POSTPROCESS_NEW_SESSION_TICKET_SIGNAL; +} + +/* + * Handler for MBEDTLS_SSL_TLS1_3_NEW_SESSION_TICKET + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_tls13_process_new_session_ticket(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + unsigned char *buf; + size_t buf_len; + unsigned char *ticket_nonce; + size_t ticket_nonce_len; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse new session ticket")); + + MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_tls13_fetch_handshake_msg( + ssl, MBEDTLS_SSL_HS_NEW_SESSION_TICKET, + &buf, &buf_len)); + + /* + * We are about to update (maybe only partially) ticket data thus block + * any session export for the time being. + */ + ssl->session->exported = 1; + + MBEDTLS_SSL_PROC_CHK(ssl_tls13_parse_new_session_ticket( + ssl, buf, buf + buf_len, + &ticket_nonce, &ticket_nonce_len)); + + MBEDTLS_SSL_PROC_CHK_NEG(ssl_tls13_postprocess_new_session_ticket( + ssl, ticket_nonce, ticket_nonce_len)); + + switch (ret) { + case POSTPROCESS_NEW_SESSION_TICKET_SIGNAL: + /* + * All good, we have received a new valid ticket, session data can + * be exported now and we signal the ticket to the application. + */ + ssl->session->exported = 0; + ret = MBEDTLS_ERR_SSL_RECEIVED_NEW_SESSION_TICKET; + break; + + case POSTPROCESS_NEW_SESSION_TICKET_DISCARD: + ret = 0; + MBEDTLS_SSL_DEBUG_MSG(2, ("Discard new session ticket")); + break; + + default: + ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_HANDSHAKE_OVER); + +cleanup: + + MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse new session ticket")); + return ret; +} +#endif /* MBEDTLS_SSL_SESSION_TICKETS */ + +int mbedtls_ssl_tls13_handshake_client_step(mbedtls_ssl_context *ssl) +{ + int ret = 0; + + switch (ssl->state) { + case MBEDTLS_SSL_HELLO_REQUEST: + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_HELLO); + break; + + case MBEDTLS_SSL_CLIENT_HELLO: + ret = mbedtls_ssl_write_client_hello(ssl); + break; + + case MBEDTLS_SSL_SERVER_HELLO: + ret = ssl_tls13_process_server_hello(ssl); + break; + + case MBEDTLS_SSL_ENCRYPTED_EXTENSIONS: + ret = ssl_tls13_process_encrypted_extensions(ssl); + break; + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED) + case MBEDTLS_SSL_CERTIFICATE_REQUEST: + ret = ssl_tls13_process_certificate_request(ssl); + break; + + case MBEDTLS_SSL_SERVER_CERTIFICATE: + ret = ssl_tls13_process_server_certificate(ssl); + break; + + case MBEDTLS_SSL_CERTIFICATE_VERIFY: + ret = ssl_tls13_process_certificate_verify(ssl); + break; +#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED */ + + case MBEDTLS_SSL_SERVER_FINISHED: + ret = ssl_tls13_process_server_finished(ssl); + break; + +#if defined(MBEDTLS_SSL_EARLY_DATA) + case MBEDTLS_SSL_END_OF_EARLY_DATA: + ret = ssl_tls13_write_end_of_early_data(ssl); + break; +#endif + + case MBEDTLS_SSL_CLIENT_CERTIFICATE: + ret = ssl_tls13_write_client_certificate(ssl); + break; + +#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED) + case MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY: + ret = ssl_tls13_write_client_certificate_verify(ssl); + break; +#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED */ + + case MBEDTLS_SSL_CLIENT_FINISHED: + ret = ssl_tls13_write_client_finished(ssl); + break; + + case MBEDTLS_SSL_FLUSH_BUFFERS: + ret = ssl_tls13_flush_buffers(ssl); + break; + + case MBEDTLS_SSL_HANDSHAKE_WRAPUP: + ret = ssl_tls13_handshake_wrapup(ssl); + break; + + /* + * Injection of dummy-CCS's for middlebox compatibility + */ +#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE) + case MBEDTLS_SSL_CLIENT_CCS_BEFORE_2ND_CLIENT_HELLO: + ret = mbedtls_ssl_tls13_write_change_cipher_spec(ssl); + if (ret != 0) { + break; + } + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_HELLO); + break; + + case MBEDTLS_SSL_CLIENT_CCS_AFTER_SERVER_FINISHED: + ret = mbedtls_ssl_tls13_write_change_cipher_spec(ssl); + if (ret != 0) { + break; + } + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE); + break; + +#if defined(MBEDTLS_SSL_EARLY_DATA) + case MBEDTLS_SSL_CLIENT_CCS_AFTER_CLIENT_HELLO: + ret = mbedtls_ssl_tls13_write_change_cipher_spec(ssl); + if (ret == 0) { + mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_SERVER_HELLO); + + MBEDTLS_SSL_DEBUG_MSG( + 1, ("Switch to early data keys for outbound traffic")); + mbedtls_ssl_set_outbound_transform( + ssl, ssl->handshake->transform_earlydata); + ssl->early_data_state = MBEDTLS_SSL_EARLY_DATA_STATE_CAN_WRITE; + } + break; +#endif /* MBEDTLS_SSL_EARLY_DATA */ +#endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */ + +#if defined(MBEDTLS_SSL_SESSION_TICKETS) + case MBEDTLS_SSL_TLS1_3_NEW_SESSION_TICKET: + ret = ssl_tls13_process_new_session_ticket(ssl); + break; +#endif /* MBEDTLS_SSL_SESSION_TICKETS */ + + default: + MBEDTLS_SSL_DEBUG_MSG(1, ("invalid state %d", ssl->state)); + return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; + } + + return ret; +} + +#endif /* MBEDTLS_SSL_CLI_C && MBEDTLS_SSL_PROTO_TLS1_3 */ |