| /* |
| * TLS 1.3 server-side functions |
| * |
| * Copyright The Mbed TLS Contributors |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| * not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "common.h" |
| |
| #if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_PROTO_TLS1_3) |
| |
| #include "mbedtls/debug.h" |
| #include "mbedtls/error.h" |
| #include "mbedtls/platform.h" |
| #include "mbedtls/constant_time.h" |
| |
| #include "ssl_misc.h" |
| #include "ssl_tls13_keys.h" |
| #include "ssl_debug_helpers.h" |
| |
| |
| static const mbedtls_ssl_ciphersuite_t *ssl_tls13_validate_peer_ciphersuite( |
| mbedtls_ssl_context *ssl, |
| unsigned int cipher_suite) |
| { |
| const mbedtls_ssl_ciphersuite_t *ciphersuite_info; |
| if (!mbedtls_ssl_tls13_cipher_suite_is_offered(ssl, cipher_suite)) { |
| return NULL; |
| } |
| |
| ciphersuite_info = mbedtls_ssl_ciphersuite_from_id(cipher_suite); |
| if ((mbedtls_ssl_validate_ciphersuite(ssl, ciphersuite_info, |
| ssl->tls_version, |
| ssl->tls_version) != 0)) { |
| return NULL; |
| } |
| return ciphersuite_info; |
| } |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) |
| /* From RFC 8446: |
| * |
| * 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_parse_key_exchange_modes_ext(mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| const unsigned char *end) |
| { |
| const unsigned char *p = buf; |
| size_t ke_modes_len; |
| int ke_modes = 0; |
| |
| /* Read ke_modes length (1 Byte) */ |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 1); |
| ke_modes_len = *p++; |
| /* Currently, there are only two PSK modes, so even without looking |
| * at the content, something's wrong if the list has more than 2 items. */ |
| if (ke_modes_len > 2) { |
| MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, |
| MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); |
| return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; |
| } |
| |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, ke_modes_len); |
| |
| while (ke_modes_len-- != 0) { |
| switch (*p++) { |
| case MBEDTLS_SSL_TLS1_3_PSK_MODE_PURE: |
| ke_modes |= MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK; |
| MBEDTLS_SSL_DEBUG_MSG(3, ("Found PSK KEX MODE")); |
| break; |
| case MBEDTLS_SSL_TLS1_3_PSK_MODE_ECDHE: |
| ke_modes |= MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL; |
| MBEDTLS_SSL_DEBUG_MSG(3, ("Found PSK_EPHEMERAL KEX MODE")); |
| break; |
| default: |
| MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, |
| MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); |
| return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; |
| } |
| } |
| |
| ssl->handshake->tls13_kex_modes = ke_modes; |
| return 0; |
| } |
| |
| #define SSL_TLS1_3_OFFERED_PSK_NOT_MATCH 1 |
| #define SSL_TLS1_3_OFFERED_PSK_MATCH 0 |
| |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_offered_psks_check_identity_match_ticket( |
| mbedtls_ssl_context *ssl, |
| const unsigned char *identity, |
| size_t identity_len, |
| uint32_t obfuscated_ticket_age, |
| mbedtls_ssl_session *session) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *ticket_buffer; |
| #if defined(MBEDTLS_HAVE_TIME) |
| mbedtls_time_t now; |
| uint64_t age_in_s; |
| int64_t age_diff_in_ms; |
| #endif |
| |
| ((void) obfuscated_ticket_age); |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("=> check_identity_match_ticket")); |
| |
| /* Ticket parser is not configured, Skip */ |
| if (ssl->conf->f_ticket_parse == NULL || identity_len == 0) { |
| return 0; |
| } |
| |
| /* We create a copy of the encrypted ticket since the ticket parsing |
| * function is allowed to use its input buffer as an output buffer |
| * (in-place decryption). We do, however, need the original buffer for |
| * computing the PSK binder value. |
| */ |
| ticket_buffer = mbedtls_calloc(1, identity_len); |
| if (ticket_buffer == NULL) { |
| MBEDTLS_SSL_DEBUG_MSG(1, ("buffer too small")); |
| return MBEDTLS_ERR_SSL_ALLOC_FAILED; |
| } |
| memcpy(ticket_buffer, identity, identity_len); |
| |
| if ((ret = ssl->conf->f_ticket_parse(ssl->conf->p_ticket, |
| session, |
| ticket_buffer, identity_len)) != 0) { |
| if (ret == MBEDTLS_ERR_SSL_INVALID_MAC) { |
| MBEDTLS_SSL_DEBUG_MSG(3, ("ticket is not authentic")); |
| } else if (ret == MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED) { |
| MBEDTLS_SSL_DEBUG_MSG(3, ("ticket is expired")); |
| } else { |
| MBEDTLS_SSL_DEBUG_RET(1, "ticket_parse", ret); |
| } |
| } |
| |
| /* We delete the temporary buffer */ |
| mbedtls_free(ticket_buffer); |
| |
| if (ret != 0) { |
| goto exit; |
| } |
| |
| /* RFC 8446 section 4.2.9 |
| * |
| * Servers SHOULD NOT send NewSessionTicket with tickets that are not |
| * compatible with the advertised modes; however, if a server does so, |
| * the impact will just be that the client's attempts at resumption fail. |
| * |
| * We regard the ticket with incompatible key exchange modes as not match. |
| */ |
| ret = MBEDTLS_ERR_ERROR_GENERIC_ERROR; |
| MBEDTLS_SSL_PRINT_TICKET_FLAGS(4, |
| session->ticket_flags); |
| if (mbedtls_ssl_tls13_check_kex_modes( |
| ssl, |
| mbedtls_ssl_session_get_ticket_flags( |
| session, |
| MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ALL))) { |
| MBEDTLS_SSL_DEBUG_MSG(3, ("No suitable key exchange mode")); |
| goto exit; |
| } |
| |
| ret = MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED; |
| #if defined(MBEDTLS_HAVE_TIME) |
| now = mbedtls_time(NULL); |
| |
| if (now < session->start) { |
| MBEDTLS_SSL_DEBUG_MSG( |
| 3, ("Invalid ticket start time ( now=%" MBEDTLS_PRINTF_LONGLONG |
| ", start=%" MBEDTLS_PRINTF_LONGLONG " )", |
| (long long) now, (long long) session->start)); |
| goto exit; |
| } |
| |
| age_in_s = (uint64_t) (now - session->start); |
| |
| /* RFC 8446 section 4.6.1 |
| * |
| * Servers MUST NOT use any value greater than 604800 seconds (7 days). |
| * |
| * RFC 8446 section 4.2.11.1 |
| * |
| * Clients MUST NOT attempt to use tickets which have ages greater than |
| * the "ticket_lifetime" value which was provided with the ticket. |
| * |
| * For time being, the age MUST be less than 604800 seconds (7 days). |
| */ |
| if (age_in_s > 604800) { |
| MBEDTLS_SSL_DEBUG_MSG( |
| 3, ("Ticket age exceeds limitation ticket_age=%lu", |
| (long unsigned int) age_in_s)); |
| goto exit; |
| } |
| |
| /* RFC 8446 section 4.2.10 |
| * |
| * For PSKs provisioned via NewSessionTicket, a server MUST validate that |
| * the ticket age for the selected PSK identity (computed by subtracting |
| * ticket_age_add from PskIdentity.obfuscated_ticket_age modulo 2^32) is |
| * within a small tolerance of the time since the ticket was issued. |
| * |
| * NOTE: When `now == session->start`, `age_diff_in_ms` may be negative |
| * as the age units are different on the server (s) and in the |
| * client (ms) side. Add a -1000 ms tolerance window to take this |
| * into account. |
| */ |
| age_diff_in_ms = age_in_s * 1000; |
| age_diff_in_ms -= (obfuscated_ticket_age - session->ticket_age_add); |
| if (age_diff_in_ms <= -1000 || |
| age_diff_in_ms > MBEDTLS_SSL_TLS1_3_TICKET_AGE_TOLERANCE) { |
| MBEDTLS_SSL_DEBUG_MSG( |
| 3, ("Ticket age outside tolerance window ( diff=%d )", |
| (int) age_diff_in_ms)); |
| goto exit; |
| } |
| |
| ret = 0; |
| |
| #endif /* MBEDTLS_HAVE_TIME */ |
| |
| exit: |
| if (ret != 0) { |
| mbedtls_ssl_session_free(session); |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("<= check_identity_match_ticket")); |
| return ret; |
| } |
| #endif /* MBEDTLS_SSL_SESSION_TICKETS */ |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_offered_psks_check_identity_match( |
| mbedtls_ssl_context *ssl, |
| const unsigned char *identity, |
| size_t identity_len, |
| uint32_t obfuscated_ticket_age, |
| int *psk_type, |
| mbedtls_ssl_session *session) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| ((void) session); |
| ((void) obfuscated_ticket_age); |
| *psk_type = MBEDTLS_SSL_TLS1_3_PSK_EXTERNAL; |
| |
| MBEDTLS_SSL_DEBUG_BUF(4, "identity", identity, identity_len); |
| ssl->handshake->resume = 0; |
| |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| if (ssl_tls13_offered_psks_check_identity_match_ticket( |
| ssl, identity, identity_len, obfuscated_ticket_age, |
| session) == SSL_TLS1_3_OFFERED_PSK_MATCH) { |
| ssl->handshake->resume = 1; |
| *psk_type = MBEDTLS_SSL_TLS1_3_PSK_RESUMPTION; |
| ret = mbedtls_ssl_set_hs_psk(ssl, |
| session->resumption_key, |
| session->resumption_key_len); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_set_hs_psk", ret); |
| return ret; |
| } |
| |
| MBEDTLS_SSL_DEBUG_BUF(4, "Ticket-resumed PSK:", |
| session->resumption_key, |
| session->resumption_key_len); |
| MBEDTLS_SSL_DEBUG_MSG(4, ("ticket: obfuscated_ticket_age: %u", |
| (unsigned) obfuscated_ticket_age)); |
| return SSL_TLS1_3_OFFERED_PSK_MATCH; |
| } |
| #endif /* MBEDTLS_SSL_SESSION_TICKETS */ |
| |
| /* Check identity with external configured function */ |
| if (ssl->conf->f_psk != NULL) { |
| if (ssl->conf->f_psk( |
| ssl->conf->p_psk, ssl, identity, identity_len) == 0) { |
| return SSL_TLS1_3_OFFERED_PSK_MATCH; |
| } |
| return SSL_TLS1_3_OFFERED_PSK_NOT_MATCH; |
| } |
| |
| MBEDTLS_SSL_DEBUG_BUF(5, "identity", identity, identity_len); |
| /* Check identity with pre-configured psk */ |
| if (ssl->conf->psk_identity != NULL && |
| identity_len == ssl->conf->psk_identity_len && |
| mbedtls_ct_memcmp(ssl->conf->psk_identity, |
| identity, identity_len) == 0) { |
| ret = mbedtls_ssl_set_hs_psk(ssl, ssl->conf->psk, ssl->conf->psk_len); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_set_hs_psk", ret); |
| return ret; |
| } |
| return SSL_TLS1_3_OFFERED_PSK_MATCH; |
| } |
| |
| return SSL_TLS1_3_OFFERED_PSK_NOT_MATCH; |
| } |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_offered_psks_check_binder_match(mbedtls_ssl_context *ssl, |
| const unsigned char *binder, |
| size_t binder_len, |
| int psk_type, |
| psa_algorithm_t psk_hash_alg) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| unsigned char transcript[PSA_HASH_MAX_SIZE]; |
| size_t transcript_len; |
| unsigned char *psk; |
| size_t psk_len; |
| unsigned char server_computed_binder[PSA_HASH_MAX_SIZE]; |
| |
| /* Get current state of handshake transcript. */ |
| ret = mbedtls_ssl_get_handshake_transcript( |
| ssl, mbedtls_hash_info_md_from_psa(psk_hash_alg), |
| transcript, sizeof(transcript), &transcript_len); |
| if (ret != 0) { |
| return ret; |
| } |
| |
| ret = mbedtls_ssl_tls13_export_handshake_psk(ssl, &psk, &psk_len); |
| if (ret != 0) { |
| return ret; |
| } |
| |
| ret = mbedtls_ssl_tls13_create_psk_binder(ssl, psk_hash_alg, |
| psk, psk_len, psk_type, |
| transcript, |
| server_computed_binder); |
| #if defined(MBEDTLS_USE_PSA_CRYPTO) |
| mbedtls_free((void *) psk); |
| #endif |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_MSG(1, ("PSK binder calculation failed.")); |
| return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; |
| } |
| |
| MBEDTLS_SSL_DEBUG_BUF(3, "psk binder ( computed ): ", |
| server_computed_binder, transcript_len); |
| MBEDTLS_SSL_DEBUG_BUF(3, "psk binder ( received ): ", binder, binder_len); |
| |
| if (mbedtls_ct_memcmp(server_computed_binder, binder, binder_len) == 0) { |
| return SSL_TLS1_3_OFFERED_PSK_MATCH; |
| } |
| |
| mbedtls_platform_zeroize(server_computed_binder, |
| sizeof(server_computed_binder)); |
| return SSL_TLS1_3_OFFERED_PSK_NOT_MATCH; |
| } |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_select_ciphersuite_for_psk( |
| mbedtls_ssl_context *ssl, |
| const unsigned char *cipher_suites, |
| const unsigned char *cipher_suites_end, |
| uint16_t *selected_ciphersuite, |
| const mbedtls_ssl_ciphersuite_t **selected_ciphersuite_info) |
| { |
| psa_algorithm_t psk_hash_alg = PSA_ALG_SHA_256; |
| |
| *selected_ciphersuite = 0; |
| *selected_ciphersuite_info = NULL; |
| |
| /* RFC 8446, page 55. |
| * |
| * For externally established PSKs, the Hash algorithm MUST be set when the |
| * PSK is established or default to SHA-256 if no such algorithm is defined. |
| * |
| */ |
| |
| /* |
| * Search for a matching ciphersuite |
| */ |
| for (const unsigned char *p = cipher_suites; |
| p < cipher_suites_end; p += 2) { |
| uint16_t cipher_suite; |
| const mbedtls_ssl_ciphersuite_t *ciphersuite_info; |
| |
| cipher_suite = MBEDTLS_GET_UINT16_BE(p, 0); |
| ciphersuite_info = ssl_tls13_validate_peer_ciphersuite(ssl, |
| cipher_suite); |
| if (ciphersuite_info == NULL) { |
| continue; |
| } |
| |
| /* MAC of selected ciphersuite MUST be same with PSK binder if exist. |
| * Otherwise, client should reject. |
| */ |
| if (psk_hash_alg == mbedtls_psa_translate_md(ciphersuite_info->mac)) { |
| *selected_ciphersuite = cipher_suite; |
| *selected_ciphersuite_info = ciphersuite_info; |
| return 0; |
| } |
| } |
| MBEDTLS_SSL_DEBUG_MSG(2, ("No matched ciphersuite")); |
| return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; |
| } |
| |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_select_ciphersuite_for_resumption( |
| mbedtls_ssl_context *ssl, |
| const unsigned char *cipher_suites, |
| const unsigned char *cipher_suites_end, |
| mbedtls_ssl_session *session, |
| uint16_t *selected_ciphersuite, |
| const mbedtls_ssl_ciphersuite_t **selected_ciphersuite_info) |
| { |
| |
| *selected_ciphersuite = 0; |
| *selected_ciphersuite_info = NULL; |
| for (const unsigned char *p = cipher_suites; p < cipher_suites_end; p += 2) { |
| uint16_t cipher_suite = MBEDTLS_GET_UINT16_BE(p, 0); |
| const mbedtls_ssl_ciphersuite_t *ciphersuite_info; |
| |
| if (cipher_suite != session->ciphersuite) { |
| continue; |
| } |
| |
| ciphersuite_info = ssl_tls13_validate_peer_ciphersuite(ssl, |
| cipher_suite); |
| if (ciphersuite_info == NULL) { |
| continue; |
| } |
| |
| *selected_ciphersuite = cipher_suite; |
| *selected_ciphersuite_info = ciphersuite_info; |
| |
| return 0; |
| } |
| |
| return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; |
| } |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_session_copy_ticket(mbedtls_ssl_session *dst, |
| const mbedtls_ssl_session *src) |
| { |
| dst->ticket_age_add = src->ticket_age_add; |
| dst->ticket_flags = src->ticket_flags; |
| dst->resumption_key_len = src->resumption_key_len; |
| if (src->resumption_key_len == 0) { |
| return MBEDTLS_ERR_SSL_INTERNAL_ERROR; |
| } |
| memcpy(dst->resumption_key, src->resumption_key, src->resumption_key_len); |
| |
| return 0; |
| } |
| #endif /* MBEDTLS_SSL_SESSION_TICKETS */ |
| |
| /* Parser for pre_shared_key extension in client hello |
| * 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; |
| */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_parse_pre_shared_key_ext(mbedtls_ssl_context *ssl, |
| const unsigned char *pre_shared_key_ext, |
| const unsigned char *pre_shared_key_ext_end, |
| const unsigned char *ciphersuites, |
| const unsigned char *ciphersuites_end) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| const unsigned char *identities = pre_shared_key_ext; |
| const unsigned char *p_identity_len; |
| size_t identities_len; |
| const unsigned char *identities_end; |
| const unsigned char *binders; |
| const unsigned char *p_binder_len; |
| size_t binders_len; |
| const unsigned char *binders_end; |
| int matched_identity = -1; |
| int identity_id = -1; |
| |
| MBEDTLS_SSL_DEBUG_BUF(3, "pre_shared_key extension", |
| pre_shared_key_ext, |
| pre_shared_key_ext_end - pre_shared_key_ext); |
| |
| /* identities_len 2 bytes |
| * identities_data >= 7 bytes |
| */ |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(identities, pre_shared_key_ext_end, 7 + 2); |
| identities_len = MBEDTLS_GET_UINT16_BE(identities, 0); |
| p_identity_len = identities + 2; |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p_identity_len, pre_shared_key_ext_end, |
| identities_len); |
| identities_end = p_identity_len + identities_len; |
| |
| /* binders_len 2 bytes |
| * binders >= 33 bytes |
| */ |
| binders = identities_end; |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(binders, pre_shared_key_ext_end, 33 + 2); |
| binders_len = MBEDTLS_GET_UINT16_BE(binders, 0); |
| p_binder_len = binders + 2; |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p_binder_len, pre_shared_key_ext_end, binders_len); |
| binders_end = p_binder_len + binders_len; |
| |
| ret = ssl->handshake->update_checksum(ssl, pre_shared_key_ext, |
| identities_end - pre_shared_key_ext); |
| if (0 != ret) { |
| MBEDTLS_SSL_DEBUG_RET(1, ("update_checksum"), ret); |
| return ret; |
| } |
| |
| while (p_identity_len < identities_end && p_binder_len < binders_end) { |
| const unsigned char *identity; |
| size_t identity_len; |
| uint32_t obfuscated_ticket_age; |
| const unsigned char *binder; |
| size_t binder_len; |
| int psk_type; |
| uint16_t cipher_suite; |
| const mbedtls_ssl_ciphersuite_t *ciphersuite_info; |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| mbedtls_ssl_session session; |
| mbedtls_ssl_session_init(&session); |
| #endif |
| |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p_identity_len, identities_end, 2 + 1 + 4); |
| identity_len = MBEDTLS_GET_UINT16_BE(p_identity_len, 0); |
| identity = p_identity_len + 2; |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(identity, identities_end, identity_len + 4); |
| obfuscated_ticket_age = MBEDTLS_GET_UINT32_BE(identity, identity_len); |
| p_identity_len += identity_len + 6; |
| |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p_binder_len, binders_end, 1 + 32); |
| binder_len = *p_binder_len; |
| binder = p_binder_len + 1; |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(binder, binders_end, binder_len); |
| p_binder_len += binder_len + 1; |
| |
| identity_id++; |
| if (matched_identity != -1) { |
| continue; |
| } |
| |
| ret = ssl_tls13_offered_psks_check_identity_match( |
| ssl, identity, identity_len, obfuscated_ticket_age, |
| &psk_type, &session); |
| if (ret != SSL_TLS1_3_OFFERED_PSK_MATCH) { |
| continue; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG(4, ("found matched identity")); |
| switch (psk_type) { |
| case MBEDTLS_SSL_TLS1_3_PSK_EXTERNAL: |
| ret = ssl_tls13_select_ciphersuite_for_psk( |
| ssl, ciphersuites, ciphersuites_end, |
| &cipher_suite, &ciphersuite_info); |
| break; |
| case MBEDTLS_SSL_TLS1_3_PSK_RESUMPTION: |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| ret = ssl_tls13_select_ciphersuite_for_resumption( |
| ssl, ciphersuites, ciphersuites_end, &session, |
| &cipher_suite, &ciphersuite_info); |
| if (ret != 0) { |
| mbedtls_ssl_session_free(&session); |
| } |
| #else |
| ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; |
| #endif |
| break; |
| default: |
| return MBEDTLS_ERR_SSL_INTERNAL_ERROR; |
| } |
| if (ret != 0) { |
| /* See below, no cipher_suite available, abort handshake */ |
| MBEDTLS_SSL_PEND_FATAL_ALERT( |
| MBEDTLS_SSL_ALERT_MSG_DECRYPT_ERROR, |
| MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE); |
| MBEDTLS_SSL_DEBUG_RET( |
| 2, "ssl_tls13_select_ciphersuite", ret); |
| return ret; |
| } |
| |
| ret = ssl_tls13_offered_psks_check_binder_match( |
| ssl, binder, binder_len, psk_type, |
| mbedtls_psa_translate_md(ciphersuite_info->mac)); |
| if (ret != SSL_TLS1_3_OFFERED_PSK_MATCH) { |
| /* For security reasons, the handshake should be aborted when we |
| * fail to validate a binder value. See RFC 8446 section 4.2.11.2 |
| * and appendix E.6. */ |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| mbedtls_ssl_session_free(&session); |
| #endif |
| MBEDTLS_SSL_DEBUG_MSG(3, ("Invalid binder.")); |
| MBEDTLS_SSL_DEBUG_RET(1, |
| "ssl_tls13_offered_psks_check_binder_match", ret); |
| MBEDTLS_SSL_PEND_FATAL_ALERT( |
| MBEDTLS_SSL_ALERT_MSG_DECRYPT_ERROR, |
| MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE); |
| return ret; |
| } |
| |
| matched_identity = identity_id; |
| |
| /* Update handshake parameters */ |
| ssl->handshake->ciphersuite_info = ciphersuite_info; |
| ssl->session_negotiate->ciphersuite = cipher_suite; |
| MBEDTLS_SSL_DEBUG_MSG(2, ("overwrite ciphersuite: %04x - %s", |
| cipher_suite, ciphersuite_info->name)); |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| if (psk_type == MBEDTLS_SSL_TLS1_3_PSK_RESUMPTION) { |
| ret = ssl_tls13_session_copy_ticket(ssl->session_negotiate, |
| &session); |
| mbedtls_ssl_session_free(&session); |
| if (ret != 0) { |
| return ret; |
| } |
| } |
| #endif /* MBEDTLS_SSL_SESSION_TICKETS */ |
| } |
| |
| if (p_identity_len != identities_end || p_binder_len != binders_end) { |
| MBEDTLS_SSL_DEBUG_MSG(3, ("pre_shared_key extension decode error")); |
| MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, |
| MBEDTLS_ERR_SSL_DECODE_ERROR); |
| return MBEDTLS_ERR_SSL_DECODE_ERROR; |
| } |
| |
| /* Update the handshake transcript with the binder list. */ |
| ret = ssl->handshake->update_checksum(ssl, |
| identities_end, |
| (size_t) (binders_end - identities_end)); |
| if (0 != ret) { |
| MBEDTLS_SSL_DEBUG_RET(1, ("update_checksum"), ret); |
| return ret; |
| } |
| if (matched_identity == -1) { |
| MBEDTLS_SSL_DEBUG_MSG(3, ("No matched PSK or ticket.")); |
| return MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY; |
| } |
| |
| ssl->handshake->selected_identity = (uint16_t) matched_identity; |
| MBEDTLS_SSL_DEBUG_MSG(3, ("Pre shared key found")); |
| |
| return 0; |
| } |
| |
| /* |
| * struct { |
| * select ( Handshake.msg_type ) { |
| * .... |
| * case server_hello: |
| * uint16 selected_identity; |
| * } |
| * } PreSharedKeyExtension; |
| */ |
| static int ssl_tls13_write_server_pre_shared_key_ext(mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| unsigned char *end, |
| size_t *olen) |
| { |
| unsigned char *p = (unsigned char *) buf; |
| |
| *olen = 0; |
| |
| int not_using_psk = 0; |
| #if defined(MBEDTLS_USE_PSA_CRYPTO) |
| not_using_psk = (mbedtls_svc_key_id_is_null(ssl->handshake->psk_opaque)); |
| #else |
| not_using_psk = (ssl->handshake->psk == NULL); |
| #endif |
| if (not_using_psk) { |
| /* We shouldn't have called this extension writer unless we've |
| * chosen to use a PSK. */ |
| return MBEDTLS_ERR_SSL_INTERNAL_ERROR; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, adding pre_shared_key extension")); |
| MBEDTLS_SSL_CHK_BUF_PTR(p, end, 6); |
| |
| MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_PRE_SHARED_KEY, p, 0); |
| MBEDTLS_PUT_UINT16_BE(2, p, 2); |
| |
| MBEDTLS_PUT_UINT16_BE(ssl->handshake->selected_identity, p, 4); |
| |
| *olen = 6; |
| |
| MBEDTLS_SSL_DEBUG_MSG(4, ("sent selected_identity: %u", |
| ssl->handshake->selected_identity)); |
| |
| mbedtls_ssl_tls13_set_hs_sent_ext_mask(ssl, MBEDTLS_TLS_EXT_PRE_SHARED_KEY); |
| |
| return 0; |
| } |
| |
| #endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */ |
| |
| /* From RFC 8446: |
| * struct { |
| * ProtocolVersion versions<2..254>; |
| * } SupportedVersions; |
| */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_parse_supported_versions_ext(mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| const unsigned char *end) |
| { |
| const unsigned char *p = buf; |
| size_t versions_len; |
| const unsigned char *versions_end; |
| uint16_t tls_version; |
| int tls13_supported = 0; |
| |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 1); |
| versions_len = p[0]; |
| p += 1; |
| |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, versions_len); |
| versions_end = p + versions_len; |
| while (p < versions_end) { |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, versions_end, 2); |
| tls_version = mbedtls_ssl_read_version(p, ssl->conf->transport); |
| p += 2; |
| |
| /* In this implementation we only support TLS 1.3 and DTLS 1.3. */ |
| if (tls_version == MBEDTLS_SSL_VERSION_TLS1_3) { |
| tls13_supported = 1; |
| break; |
| } |
| } |
| |
| if (!tls13_supported) { |
| MBEDTLS_SSL_DEBUG_MSG(1, ("TLS 1.3 is not supported by the client")); |
| |
| MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION, |
| MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION); |
| return MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG(1, ("Negotiated version. Supported is [%04x]", |
| (unsigned int) tls_version)); |
| |
| return 0; |
| } |
| |
| #if defined(MBEDTLS_ECDH_C) |
| /* |
| * |
| * From RFC 8446: |
| * enum { |
| * ... (0xFFFF) |
| * } NamedGroup; |
| * struct { |
| * NamedGroup named_group_list<2..2^16-1>; |
| * } NamedGroupList; |
| */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_parse_supported_groups_ext(mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| const unsigned char *end) |
| { |
| const unsigned char *p = buf; |
| size_t named_group_list_len; |
| const unsigned char *named_group_list_end; |
| |
| MBEDTLS_SSL_DEBUG_BUF(3, "supported_groups extension", p, end - buf); |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 2); |
| named_group_list_len = MBEDTLS_GET_UINT16_BE(p, 0); |
| p += 2; |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, named_group_list_len); |
| named_group_list_end = p + named_group_list_len; |
| ssl->handshake->hrr_selected_group = 0; |
| |
| while (p < named_group_list_end) { |
| uint16_t named_group; |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, named_group_list_end, 2); |
| named_group = MBEDTLS_GET_UINT16_BE(p, 0); |
| p += 2; |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, |
| ("got named group: %s(%04x)", |
| mbedtls_ssl_named_group_to_str(named_group), |
| named_group)); |
| |
| if (!mbedtls_ssl_named_group_is_offered(ssl, named_group) || |
| !mbedtls_ssl_named_group_is_supported(named_group) || |
| ssl->handshake->hrr_selected_group != 0) { |
| continue; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, |
| ("add named group %s(%04x) into received list.", |
| mbedtls_ssl_named_group_to_str(named_group), |
| named_group)); |
| |
| ssl->handshake->hrr_selected_group = named_group; |
| } |
| |
| return 0; |
| |
| } |
| #endif /* MBEDTLS_ECDH_C */ |
| |
| #define SSL_TLS1_3_PARSE_KEY_SHARES_EXT_NO_MATCH 1 |
| |
| #if defined(MBEDTLS_ECDH_C) |
| /* |
| * ssl_tls13_parse_key_shares_ext() verifies whether the information in the |
| * extension is correct and stores the first acceptable key share and its associated group. |
| * |
| * Possible return values are: |
| * - 0: Successful processing of the client provided key share extension. |
| * - SSL_TLS1_3_PARSE_KEY_SHARES_EXT_NO_MATCH: The key shares provided by the client |
| * does not match a group supported by the server. A HelloRetryRequest will |
| * be needed. |
| * - A negative value for fatal errors. |
| */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_parse_key_shares_ext(mbedtls_ssl_context *ssl, |
| const unsigned char *buf, |
| const unsigned char *end) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char const *p = buf; |
| unsigned char const *client_shares_end; |
| size_t client_shares_len; |
| |
| /* From RFC 8446: |
| * |
| * struct { |
| * KeyShareEntry client_shares<0..2^16-1>; |
| * } KeyShareClientHello; |
| * |
| */ |
| |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 2); |
| client_shares_len = MBEDTLS_GET_UINT16_BE(p, 0); |
| p += 2; |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, client_shares_len); |
| |
| ssl->handshake->offered_group_id = 0; |
| client_shares_end = p + client_shares_len; |
| |
| /* We try to find a suitable key share entry and copy it to the |
| * handshake context. Later, we have to find out whether we can do |
| * something with the provided key share or whether we have to |
| * dismiss it and send a HelloRetryRequest message. |
| */ |
| |
| while (p < client_shares_end) { |
| uint16_t group; |
| size_t key_exchange_len; |
| const unsigned char *key_exchange; |
| |
| /* |
| * struct { |
| * NamedGroup group; |
| * opaque key_exchange<1..2^16-1>; |
| * } KeyShareEntry; |
| */ |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, client_shares_end, 4); |
| group = MBEDTLS_GET_UINT16_BE(p, 0); |
| key_exchange_len = MBEDTLS_GET_UINT16_BE(p, 2); |
| p += 4; |
| key_exchange = p; |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, client_shares_end, key_exchange_len); |
| p += key_exchange_len; |
| |
| /* Continue parsing even if we have already found a match, |
| * for input validation purposes. |
| */ |
| if (!mbedtls_ssl_named_group_is_offered(ssl, group) || |
| !mbedtls_ssl_named_group_is_supported(group) || |
| ssl->handshake->offered_group_id != 0) { |
| continue; |
| } |
| |
| /* |
| * For now, we only support ECDHE groups. |
| */ |
| if (mbedtls_ssl_tls13_named_group_is_ecdhe(group)) { |
| MBEDTLS_SSL_DEBUG_MSG(2, ("ECDH group: %s (%04x)", |
| mbedtls_ssl_named_group_to_str(group), |
| group)); |
| ret = mbedtls_ssl_tls13_read_public_ecdhe_share( |
| ssl, key_exchange - 2, key_exchange_len + 2); |
| if (ret != 0) { |
| return ret; |
| } |
| |
| } else { |
| MBEDTLS_SSL_DEBUG_MSG(4, ("Unrecognized NamedGroup %u", |
| (unsigned) group)); |
| continue; |
| } |
| |
| ssl->handshake->offered_group_id = group; |
| } |
| |
| |
| if (ssl->handshake->offered_group_id == 0) { |
| MBEDTLS_SSL_DEBUG_MSG(1, ("no matching key share")); |
| return SSL_TLS1_3_PARSE_KEY_SHARES_EXT_NO_MATCH; |
| } |
| return 0; |
| } |
| #endif /* MBEDTLS_ECDH_C */ |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_client_hello_has_exts(mbedtls_ssl_context *ssl, |
| int exts_mask) |
| { |
| int masked = ssl->handshake->received_extensions & exts_mask; |
| return masked == exts_mask; |
| } |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED) |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_client_hello_has_exts_for_ephemeral_key_exchange( |
| mbedtls_ssl_context *ssl) |
| { |
| return ssl_tls13_client_hello_has_exts( |
| ssl, |
| MBEDTLS_SSL_EXT_MASK(SUPPORTED_GROUPS) | |
| MBEDTLS_SSL_EXT_MASK(KEY_SHARE) | |
| MBEDTLS_SSL_EXT_MASK(SIG_ALG)); |
| } |
| #endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED */ |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED) |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_client_hello_has_exts_for_psk_key_exchange( |
| mbedtls_ssl_context *ssl) |
| { |
| return ssl_tls13_client_hello_has_exts( |
| ssl, |
| MBEDTLS_SSL_EXT_MASK(PRE_SHARED_KEY) | |
| MBEDTLS_SSL_EXT_MASK(PSK_KEY_EXCHANGE_MODES)); |
| } |
| #endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED */ |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED) |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_client_hello_has_exts_for_psk_ephemeral_key_exchange( |
| mbedtls_ssl_context *ssl) |
| { |
| return ssl_tls13_client_hello_has_exts( |
| ssl, |
| MBEDTLS_SSL_EXT_MASK(SUPPORTED_GROUPS) | |
| MBEDTLS_SSL_EXT_MASK(KEY_SHARE) | |
| MBEDTLS_SSL_EXT_MASK(PRE_SHARED_KEY) | |
| MBEDTLS_SSL_EXT_MASK(PSK_KEY_EXCHANGE_MODES)); |
| } |
| #endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED */ |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_check_ephemeral_key_exchange(mbedtls_ssl_context *ssl) |
| { |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED) |
| return mbedtls_ssl_conf_tls13_ephemeral_enabled(ssl) && |
| ssl_tls13_client_hello_has_exts_for_ephemeral_key_exchange(ssl); |
| #else |
| ((void) ssl); |
| return 0; |
| #endif |
| } |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_check_psk_key_exchange(mbedtls_ssl_context *ssl) |
| { |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED) |
| return mbedtls_ssl_conf_tls13_psk_enabled(ssl) && |
| mbedtls_ssl_tls13_psk_enabled(ssl) && |
| ssl_tls13_client_hello_has_exts_for_psk_key_exchange(ssl); |
| #else |
| ((void) ssl); |
| return 0; |
| #endif |
| } |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_check_psk_ephemeral_key_exchange(mbedtls_ssl_context *ssl) |
| { |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED) |
| return mbedtls_ssl_conf_tls13_psk_ephemeral_enabled(ssl) && |
| mbedtls_ssl_tls13_psk_ephemeral_enabled(ssl) && |
| ssl_tls13_client_hello_has_exts_for_psk_ephemeral_key_exchange(ssl); |
| #else |
| ((void) ssl); |
| return 0; |
| #endif |
| } |
| |
| static int ssl_tls13_determine_key_exchange_mode(mbedtls_ssl_context *ssl) |
| { |
| /* |
| * Determine the key exchange algorithm to use. |
| * There are three types of key exchanges supported in TLS 1.3: |
| * - (EC)DH with ECDSA, |
| * - (EC)DH with PSK, |
| * - plain PSK. |
| * |
| * The PSK-based key exchanges may additionally be used with 0-RTT. |
| * |
| * Our built-in order of preference is |
| * 1 ) (EC)DHE-PSK Mode ( psk_ephemeral ) |
| * 2 ) Certificate Mode ( ephemeral ) |
| * 3 ) Plain PSK Mode ( psk ) |
| */ |
| |
| ssl->handshake->key_exchange_mode = MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_NONE; |
| |
| if (ssl_tls13_check_psk_ephemeral_key_exchange(ssl)) { |
| ssl->handshake->key_exchange_mode = |
| MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL; |
| MBEDTLS_SSL_DEBUG_MSG(2, ("key exchange mode: psk_ephemeral")); |
| } else |
| if (ssl_tls13_check_ephemeral_key_exchange(ssl)) { |
| ssl->handshake->key_exchange_mode = |
| MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL; |
| MBEDTLS_SSL_DEBUG_MSG(2, ("key exchange mode: ephemeral")); |
| } else |
| if (ssl_tls13_check_psk_key_exchange(ssl)) { |
| ssl->handshake->key_exchange_mode = |
| MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK; |
| MBEDTLS_SSL_DEBUG_MSG(2, ("key exchange mode: psk")); |
| } else { |
| MBEDTLS_SSL_DEBUG_MSG( |
| 1, |
| ("ClientHello message misses mandatory extensions.")); |
| MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_MISSING_EXTENSION, |
| MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); |
| return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; |
| } |
| |
| return 0; |
| |
| } |
| |
| #if defined(MBEDTLS_X509_CRT_PARSE_C) && \ |
| defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED) |
| |
| #if defined(MBEDTLS_USE_PSA_CRYPTO) |
| static psa_algorithm_t ssl_tls13_iana_sig_alg_to_psa_alg(uint16_t sig_alg) |
| { |
| switch (sig_alg) { |
| case MBEDTLS_TLS1_3_SIG_ECDSA_SECP256R1_SHA256: |
| return PSA_ALG_ECDSA(PSA_ALG_SHA_256); |
| case MBEDTLS_TLS1_3_SIG_ECDSA_SECP384R1_SHA384: |
| return PSA_ALG_ECDSA(PSA_ALG_SHA_384); |
| case MBEDTLS_TLS1_3_SIG_ECDSA_SECP521R1_SHA512: |
| return PSA_ALG_ECDSA(PSA_ALG_SHA_512); |
| case MBEDTLS_TLS1_3_SIG_RSA_PSS_RSAE_SHA256: |
| return PSA_ALG_RSA_PSS(PSA_ALG_SHA_256); |
| case MBEDTLS_TLS1_3_SIG_RSA_PSS_RSAE_SHA384: |
| return PSA_ALG_RSA_PSS(PSA_ALG_SHA_384); |
| case MBEDTLS_TLS1_3_SIG_RSA_PSS_RSAE_SHA512: |
| return PSA_ALG_RSA_PSS(PSA_ALG_SHA_512); |
| case MBEDTLS_TLS1_3_SIG_RSA_PKCS1_SHA256: |
| return PSA_ALG_RSA_PKCS1V15_SIGN(PSA_ALG_SHA_256); |
| case MBEDTLS_TLS1_3_SIG_RSA_PKCS1_SHA384: |
| return PSA_ALG_RSA_PKCS1V15_SIGN(PSA_ALG_SHA_384); |
| case MBEDTLS_TLS1_3_SIG_RSA_PKCS1_SHA512: |
| return PSA_ALG_RSA_PKCS1V15_SIGN(PSA_ALG_SHA_512); |
| default: |
| return PSA_ALG_NONE; |
| } |
| } |
| #endif /* MBEDTLS_USE_PSA_CRYPTO */ |
| |
| /* |
| * Pick best ( private key, certificate chain ) pair based on the signature |
| * algorithms supported by the client. |
| */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_pick_key_cert(mbedtls_ssl_context *ssl) |
| { |
| mbedtls_ssl_key_cert *key_cert, *key_cert_list; |
| const uint16_t *sig_alg = ssl->handshake->received_sig_algs; |
| |
| #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) |
| if (ssl->handshake->sni_key_cert != NULL) { |
| key_cert_list = ssl->handshake->sni_key_cert; |
| } else |
| #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */ |
| key_cert_list = ssl->conf->key_cert; |
| |
| if (key_cert_list == NULL) { |
| MBEDTLS_SSL_DEBUG_MSG(3, ("server has no certificate")); |
| return -1; |
| } |
| |
| for (; *sig_alg != MBEDTLS_TLS1_3_SIG_NONE; sig_alg++) { |
| if (!mbedtls_ssl_sig_alg_is_offered(ssl, *sig_alg)) { |
| continue; |
| } |
| |
| if (!mbedtls_ssl_tls13_sig_alg_for_cert_verify_is_supported(*sig_alg)) { |
| continue; |
| } |
| |
| for (key_cert = key_cert_list; key_cert != NULL; |
| key_cert = key_cert->next) { |
| #if defined(MBEDTLS_USE_PSA_CRYPTO) |
| psa_algorithm_t psa_alg = PSA_ALG_NONE; |
| #endif /* MBEDTLS_USE_PSA_CRYPTO */ |
| |
| MBEDTLS_SSL_DEBUG_CRT(3, "certificate (chain) candidate", |
| key_cert->cert); |
| |
| /* |
| * This avoids sending the client a cert it'll reject based on |
| * keyUsage or other extensions. |
| */ |
| if (mbedtls_x509_crt_check_key_usage( |
| key_cert->cert, MBEDTLS_X509_KU_DIGITAL_SIGNATURE) != 0 || |
| mbedtls_x509_crt_check_extended_key_usage( |
| key_cert->cert, MBEDTLS_OID_SERVER_AUTH, |
| MBEDTLS_OID_SIZE(MBEDTLS_OID_SERVER_AUTH)) != 0) { |
| MBEDTLS_SSL_DEBUG_MSG(3, ("certificate mismatch: " |
| "(extended) key usage extension")); |
| continue; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG(3, |
| ("ssl_tls13_pick_key_cert:" |
| "check signature algorithm %s [%04x]", |
| mbedtls_ssl_sig_alg_to_str(*sig_alg), |
| *sig_alg)); |
| #if defined(MBEDTLS_USE_PSA_CRYPTO) |
| psa_alg = ssl_tls13_iana_sig_alg_to_psa_alg(*sig_alg); |
| #endif /* MBEDTLS_USE_PSA_CRYPTO */ |
| |
| if (mbedtls_ssl_tls13_check_sig_alg_cert_key_match( |
| *sig_alg, &key_cert->cert->pk) |
| #if defined(MBEDTLS_USE_PSA_CRYPTO) |
| && psa_alg != PSA_ALG_NONE && |
| mbedtls_pk_can_do_ext(&key_cert->cert->pk, psa_alg, |
| PSA_KEY_USAGE_SIGN_HASH) == 1 |
| #endif /* MBEDTLS_USE_PSA_CRYPTO */ |
| ) { |
| ssl->handshake->key_cert = key_cert; |
| MBEDTLS_SSL_DEBUG_MSG(3, |
| ("ssl_tls13_pick_key_cert:" |
| "selected signature algorithm" |
| " %s [%04x]", |
| mbedtls_ssl_sig_alg_to_str(*sig_alg), |
| *sig_alg)); |
| MBEDTLS_SSL_DEBUG_CRT( |
| 3, "selected certificate (chain)", |
| ssl->handshake->key_cert->cert); |
| return 0; |
| } |
| } |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("ssl_tls13_pick_key_cert:" |
| "no suitable certificate found")); |
| return -1; |
| } |
| #endif /* MBEDTLS_X509_CRT_PARSE_C && |
| MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED */ |
| |
| /* |
| * |
| * STATE HANDLING: ClientHello |
| * |
| * There are three possible classes of outcomes when parsing the ClientHello: |
| * |
| * 1) The ClientHello was well-formed and matched the server's configuration. |
| * |
| * In this case, the server progresses to sending its ServerHello. |
| * |
| * 2) The ClientHello was well-formed but didn't match the server's |
| * configuration. |
| * |
| * For example, the client might not have offered a key share which |
| * the server supports, or the server might require a cookie. |
| * |
| * In this case, the server sends a HelloRetryRequest. |
| * |
| * 3) The ClientHello was ill-formed |
| * |
| * In this case, we abort the handshake. |
| * |
| */ |
| |
| /* |
| * Structure of this message: |
| * |
| * uint16 ProtocolVersion; |
| * opaque Random[32]; |
| * uint8 CipherSuite[2]; // Cryptographic suite selector |
| * |
| * struct { |
| * ProtocolVersion legacy_version = 0x0303; // TLS v1.2 |
| * Random random; |
| * opaque legacy_session_id<0..32>; |
| * CipherSuite cipher_suites<2..2^16-2>; |
| * opaque legacy_compression_methods<1..2^8-1>; |
| * Extension extensions<8..2^16-1>; |
| * } ClientHello; |
| */ |
| |
| #define SSL_CLIENT_HELLO_OK 0 |
| #define SSL_CLIENT_HELLO_HRR_REQUIRED 1 |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_parse_client_hello(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 legacy_session_id_len; |
| size_t cipher_suites_len; |
| const unsigned char *cipher_suites_end; |
| size_t extensions_len; |
| const unsigned char *extensions_end; |
| mbedtls_ssl_handshake_params *handshake = ssl->handshake; |
| int hrr_required = 0; |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) |
| const unsigned char *cipher_suites; |
| const unsigned char *pre_shared_key_ext = NULL; |
| const unsigned char *pre_shared_key_ext_end = NULL; |
| #endif |
| |
| /* |
| * ClientHello layout: |
| * 0 . 1 protocol version |
| * 2 . 33 random bytes |
| * 34 . 34 session id length ( 1 byte ) |
| * 35 . 34+x session id |
| * .. . .. ciphersuite list length ( 2 bytes ) |
| * .. . .. ciphersuite list |
| * .. . .. compression alg. list length ( 1 byte ) |
| * .. . .. compression alg. list |
| * .. . .. extensions length ( 2 bytes, optional ) |
| * .. . .. extensions ( optional ) |
| */ |
| |
| /* |
| * Minimal length ( with everything empty and extensions omitted ) is |
| * 2 + 32 + 1 + 2 + 1 = 38 bytes. Check that first, so that we can |
| * read at least up to session id length without worrying. |
| */ |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 38); |
| |
| /* ... |
| * 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); |
| return MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION; |
| } |
| p += 2; |
| |
| /* |
| * Only support TLS 1.3 currently, temporarily set the version. |
| */ |
| ssl->tls_version = MBEDTLS_SSL_VERSION_TLS1_3; |
| |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| /* Store minor version for later use with ticket serialization. */ |
| ssl->session_negotiate->tls_version = MBEDTLS_SSL_VERSION_TLS1_3; |
| ssl->session_negotiate->endpoint = ssl->conf->endpoint; |
| #endif |
| |
| /* ... |
| * Random random; |
| * ... |
| * with Random defined as: |
| * opaque Random[32]; |
| */ |
| MBEDTLS_SSL_DEBUG_BUF(3, "client hello, random bytes", |
| p, MBEDTLS_CLIENT_HELLO_RANDOM_LEN); |
| |
| memcpy(&handshake->randbytes[0], p, MBEDTLS_CLIENT_HELLO_RANDOM_LEN); |
| p += MBEDTLS_CLIENT_HELLO_RANDOM_LEN; |
| |
| /* ... |
| * opaque legacy_session_id<0..32>; |
| * ... |
| */ |
| legacy_session_id_len = p[0]; |
| p++; |
| |
| if (legacy_session_id_len > sizeof(ssl->session_negotiate->id)) { |
| MBEDTLS_SSL_DEBUG_MSG(1, ("bad client hello message")); |
| return MBEDTLS_ERR_SSL_DECODE_ERROR; |
| } |
| |
| ssl->session_negotiate->id_len = legacy_session_id_len; |
| MBEDTLS_SSL_DEBUG_BUF(3, "client hello, session id", |
| p, legacy_session_id_len); |
| /* |
| * Check we have enough data for the legacy session identifier |
| * and the ciphersuite list length. |
| */ |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, legacy_session_id_len + 2); |
| |
| memcpy(&ssl->session_negotiate->id[0], p, legacy_session_id_len); |
| p += legacy_session_id_len; |
| |
| cipher_suites_len = MBEDTLS_GET_UINT16_BE(p, 0); |
| p += 2; |
| |
| /* |
| * The length of the ciphersuite list has to be even. |
| */ |
| if (cipher_suites_len & 1) { |
| MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, |
| MBEDTLS_ERR_SSL_DECODE_ERROR); |
| return MBEDTLS_ERR_SSL_DECODE_ERROR; |
| } |
| |
| /* Check we have enough data for the ciphersuite list, the legacy |
| * compression methods and the length of the extensions. |
| * |
| * cipher_suites cipher_suites_len bytes |
| * legacy_compression_methods 2 bytes |
| * extensions_len 2 bytes |
| */ |
| MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, cipher_suites_len + 2 + 2); |
| |
| /* ... |
| * CipherSuite cipher_suites<2..2^16-2>; |
| * ... |
| * with CipherSuite defined as: |
| * uint8 CipherSuite[2]; |
| */ |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) |
| cipher_suites = p; |
| #endif |
| cipher_suites_end = p + cipher_suites_len; |
| MBEDTLS_SSL_DEBUG_BUF(3, "client hello, ciphersuitelist", |
| p, cipher_suites_len); |
| |
| /* |
| * Search for a matching ciphersuite |
| */ |
| for (; p < cipher_suites_end; p += 2) { |
| uint16_t cipher_suite; |
| const mbedtls_ssl_ciphersuite_t *ciphersuite_info; |
| |
| /* |
| * "cipher_suite_end - p is even" is an invariant of the loop. As |
| * cipher_suites_end - p > 0, we have cipher_suites_end - p >= 2 and |
| * it is thus safe to read two bytes. |
| */ |
| cipher_suite = MBEDTLS_GET_UINT16_BE(p, 0); |
| ciphersuite_info = ssl_tls13_validate_peer_ciphersuite( |
| ssl, cipher_suite); |
| if (ciphersuite_info == NULL) { |
| continue; |
| } |
| |
| ssl->session_negotiate->ciphersuite = cipher_suite; |
| handshake->ciphersuite_info = ciphersuite_info; |
| MBEDTLS_SSL_DEBUG_MSG(2, ("selected ciphersuite: %04x - %s", |
| cipher_suite, |
| ciphersuite_info->name)); |
| break; |
| } |
| |
| if (handshake->ciphersuite_info == NULL) { |
| MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE, |
| MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE); |
| return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; |
| } |
| p = cipher_suites_end; |
| |
| /* ... |
| * opaque legacy_compression_methods<1..2^8-1>; |
| * ... |
| */ |
| if (p[0] != 1 || p[1] != MBEDTLS_SSL_COMPRESS_NULL) { |
| MBEDTLS_SSL_DEBUG_MSG(1, ("bad legacy compression method")); |
| MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER, |
| MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER); |
| return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; |
| } |
| p += 2; |
| |
| /* ... |
| * Extension extensions<8..2^16-1>; |
| * ... |
| * with Extension defined as: |
| * struct { |
| * ExtensionType extension_type; |
| * opaque extension_data<0..2^16-1>; |
| * } Extension; |
| */ |
| 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, "client hello 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; |
| const unsigned char *extension_data_end; |
| |
| /* RFC 8446, section 4.2.11 |
| * |
| * The "pre_shared_key" extension MUST be the last extension in the |
| * ClientHello (this facilitates implementation as described below). |
| * Servers MUST check that it is the last extension and otherwise fail |
| * the handshake with an "illegal_parameter" alert. |
| */ |
| if (handshake->received_extensions & MBEDTLS_SSL_EXT_MASK(PRE_SHARED_KEY)) { |
| MBEDTLS_SSL_DEBUG_MSG( |
| 3, ("pre_shared_key is not last 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_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, MBEDTLS_SSL_HS_CLIENT_HELLO, extension_type, |
| MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_CH); |
| if (ret != 0) { |
| return ret; |
| } |
| |
| switch (extension_type) { |
| #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) |
| case MBEDTLS_TLS_EXT_SERVERNAME: |
| MBEDTLS_SSL_DEBUG_MSG(3, ("found ServerName extension")); |
| ret = mbedtls_ssl_parse_server_name_ext(ssl, p, |
| extension_data_end); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET( |
| 1, "mbedtls_ssl_parse_servername_ext", ret); |
| return ret; |
| } |
| break; |
| #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */ |
| |
| #if defined(MBEDTLS_ECDH_C) |
| case MBEDTLS_TLS_EXT_SUPPORTED_GROUPS: |
| MBEDTLS_SSL_DEBUG_MSG(3, ("found supported group extension")); |
| |
| /* Supported Groups Extension |
| * |
| * When sent by the client, the "supported_groups" extension |
| * indicates the named groups which the client supports, |
| * ordered from most preferred to least preferred. |
| */ |
| ret = ssl_tls13_parse_supported_groups_ext( |
| ssl, p, extension_data_end); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, |
| "mbedtls_ssl_parse_supported_groups_ext", ret); |
| return ret; |
| } |
| |
| break; |
| #endif /* MBEDTLS_ECDH_C */ |
| |
| #if defined(MBEDTLS_ECDH_C) |
| case MBEDTLS_TLS_EXT_KEY_SHARE: |
| MBEDTLS_SSL_DEBUG_MSG(3, ("found key share extension")); |
| |
| /* |
| * Key Share Extension |
| * |
| * When sent by the client, the "key_share" extension |
| * contains the endpoint's cryptographic parameters for |
| * ECDHE/DHE key establishment methods. |
| */ |
| ret = ssl_tls13_parse_key_shares_ext( |
| ssl, p, extension_data_end); |
| if (ret == SSL_TLS1_3_PARSE_KEY_SHARES_EXT_NO_MATCH) { |
| MBEDTLS_SSL_DEBUG_MSG(2, ("HRR needed ")); |
| hrr_required = 1; |
| } |
| |
| if (ret < 0) { |
| MBEDTLS_SSL_DEBUG_RET( |
| 1, "ssl_tls13_parse_key_shares_ext", ret); |
| return ret; |
| } |
| |
| break; |
| #endif /* MBEDTLS_ECDH_C */ |
| |
| case MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS: |
| MBEDTLS_SSL_DEBUG_MSG(3, ("found supported versions extension")); |
| |
| ret = ssl_tls13_parse_supported_versions_ext( |
| ssl, p, extension_data_end); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, |
| ("ssl_tls13_parse_supported_versions_ext"), ret); |
| return ret; |
| } |
| break; |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) |
| case MBEDTLS_TLS_EXT_PSK_KEY_EXCHANGE_MODES: |
| MBEDTLS_SSL_DEBUG_MSG(3, ("found psk key exchange modes extension")); |
| |
| ret = ssl_tls13_parse_key_exchange_modes_ext( |
| ssl, p, extension_data_end); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET( |
| 1, "ssl_tls13_parse_key_exchange_modes_ext", ret); |
| return ret; |
| } |
| |
| break; |
| #endif |
| |
| case MBEDTLS_TLS_EXT_PRE_SHARED_KEY: |
| MBEDTLS_SSL_DEBUG_MSG(3, ("found pre_shared_key extension")); |
| if ((handshake->received_extensions & |
| MBEDTLS_SSL_EXT_MASK(PSK_KEY_EXCHANGE_MODES)) == 0) { |
| 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_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) |
| /* Delay processing of the PSK identity once we have |
| * found out which algorithms to use. We keep a pointer |
| * to the buffer and the size for later processing. |
| */ |
| pre_shared_key_ext = p; |
| pre_shared_key_ext_end = extension_data_end; |
| #endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */ |
| break; |
| |
| #if defined(MBEDTLS_SSL_ALPN) |
| case MBEDTLS_TLS_EXT_ALPN: |
| MBEDTLS_SSL_DEBUG_MSG(3, ("found alpn extension")); |
| |
| ret = mbedtls_ssl_parse_alpn_ext(ssl, p, extension_data_end); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET( |
| 1, ("mbedtls_ssl_parse_alpn_ext"), ret); |
| return ret; |
| } |
| break; |
| #endif /* MBEDTLS_SSL_ALPN */ |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED) |
| case MBEDTLS_TLS_EXT_SIG_ALG: |
| MBEDTLS_SSL_DEBUG_MSG(3, ("found signature_algorithms extension")); |
| |
| ret = mbedtls_ssl_parse_sig_alg_ext( |
| ssl, p, extension_data_end); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_MSG(1, |
| ( |
| "ssl_parse_supported_signature_algorithms_server_ext ( %d )", |
| ret)); |
| return ret; |
| } |
| break; |
| #endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED */ |
| |
| #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, extension_data_end); |
| |
| /* TODO: Return unconditionally here until we handle the record size limit correctly. |
| * Once handled correctly, only return in case of errors. */ |
| return ret; |
| |
| break; |
| #endif /* MBEDTLS_SSL_RECORD_SIZE_LIMIT */ |
| |
| default: |
| MBEDTLS_SSL_PRINT_EXT( |
| 3, MBEDTLS_SSL_HS_CLIENT_HELLO, |
| extension_type, "( ignored )"); |
| break; |
| } |
| |
| p += extension_data_len; |
| } |
| |
| MBEDTLS_SSL_PRINT_EXTS(3, MBEDTLS_SSL_HS_CLIENT_HELLO, |
| handshake->received_extensions); |
| |
| ret = mbedtls_ssl_add_hs_hdr_to_checksum(ssl, |
| MBEDTLS_SSL_HS_CLIENT_HELLO, |
| p - buf); |
| if (0 != ret) { |
| MBEDTLS_SSL_DEBUG_RET(1, ("mbedtls_ssl_add_hs_hdr_to_checksum"), ret); |
| return ret; |
| } |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) |
| /* Update checksum with either |
| * - The entire content of the CH message, if no PSK extension is present |
| * - The content up to but excluding the PSK extension, if present. |
| */ |
| /* If we've settled on a PSK-based exchange, parse PSK identity ext */ |
| if (mbedtls_ssl_tls13_some_psk_enabled(ssl) && |
| mbedtls_ssl_conf_tls13_some_psk_enabled(ssl) && |
| (handshake->received_extensions & MBEDTLS_SSL_EXT_MASK(PRE_SHARED_KEY))) { |
| ret = handshake->update_checksum(ssl, buf, |
| pre_shared_key_ext - buf); |
| if (0 != ret) { |
| MBEDTLS_SSL_DEBUG_RET(1, ("update_checksum"), ret); |
| return ret; |
| } |
| ret = ssl_tls13_parse_pre_shared_key_ext(ssl, |
| pre_shared_key_ext, |
| pre_shared_key_ext_end, |
| cipher_suites, |
| cipher_suites_end); |
| if (ret == MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY) { |
| handshake->received_extensions &= ~MBEDTLS_SSL_EXT_MASK(PRE_SHARED_KEY); |
| } else if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET( |
| 1, "ssl_tls13_parse_pre_shared_key_ext", ret); |
| return ret; |
| } |
| } else |
| #endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */ |
| { |
| ret = handshake->update_checksum(ssl, buf, p - buf); |
| if (0 != ret) { |
| MBEDTLS_SSL_DEBUG_RET(1, ("update_checksum"), ret); |
| return ret; |
| } |
| } |
| |
| ret = ssl_tls13_determine_key_exchange_mode(ssl); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| mbedtls_ssl_optimize_checksum(ssl, handshake->ciphersuite_info); |
| |
| return hrr_required ? SSL_CLIENT_HELLO_HRR_REQUIRED : SSL_CLIENT_HELLO_OK; |
| } |
| |
| /* Update the handshake state machine */ |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_postprocess_client_hello(mbedtls_ssl_context *ssl) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| /* |
| * Server certificate selection |
| */ |
| if (ssl->conf->f_cert_cb && (ret = ssl->conf->f_cert_cb(ssl)) != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, "f_cert_cb", ret); |
| return ret; |
| } |
| #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) |
| ssl->handshake->sni_name = NULL; |
| ssl->handshake->sni_name_len = 0; |
| #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */ |
| |
| ret = mbedtls_ssl_tls13_key_schedule_stage_early(ssl); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, |
| "mbedtls_ssl_tls1_3_key_schedule_stage_early", ret); |
| return ret; |
| } |
| |
| return 0; |
| |
| } |
| |
| /* |
| * Main entry point from the state machine; orchestrates the otherfunctions. |
| */ |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_process_client_hello(mbedtls_ssl_context *ssl) |
| { |
| |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *buf = NULL; |
| size_t buflen = 0; |
| int parse_client_hello_ret; |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse client hello")); |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_tls13_fetch_handshake_msg( |
| ssl, MBEDTLS_SSL_HS_CLIENT_HELLO, |
| &buf, &buflen)); |
| |
| MBEDTLS_SSL_PROC_CHK_NEG(ssl_tls13_parse_client_hello(ssl, buf, |
| buf + buflen)); |
| parse_client_hello_ret = ret; /* Store return value of parse_client_hello, |
| * only SSL_CLIENT_HELLO_OK or |
| * SSL_CLIENT_HELLO_HRR_REQUIRED at this |
| * stage as negative error codes are handled |
| * by MBEDTLS_SSL_PROC_CHK_NEG. */ |
| |
| MBEDTLS_SSL_PROC_CHK(ssl_tls13_postprocess_client_hello(ssl)); |
| |
| if (parse_client_hello_ret == SSL_CLIENT_HELLO_OK) { |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_SERVER_HELLO); |
| } else { |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_HELLO_RETRY_REQUEST); |
| } |
| |
| cleanup: |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse client hello")); |
| return ret; |
| } |
| |
| /* |
| * Handler for MBEDTLS_SSL_SERVER_HELLO |
| */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_prepare_server_hello(mbedtls_ssl_context *ssl) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *server_randbytes = |
| ssl->handshake->randbytes + MBEDTLS_CLIENT_HELLO_RANDOM_LEN; |
| if (ssl->conf->f_rng == NULL) { |
| MBEDTLS_SSL_DEBUG_MSG(1, ("no RNG provided")); |
| return MBEDTLS_ERR_SSL_NO_RNG; |
| } |
| |
| if ((ret = ssl->conf->f_rng(ssl->conf->p_rng, server_randbytes, |
| MBEDTLS_SERVER_HELLO_RANDOM_LEN)) != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, "f_rng", ret); |
| return ret; |
| } |
| |
| MBEDTLS_SSL_DEBUG_BUF(3, "server hello, random bytes", server_randbytes, |
| MBEDTLS_SERVER_HELLO_RANDOM_LEN); |
| |
| #if defined(MBEDTLS_HAVE_TIME) |
| ssl->session_negotiate->start = time(NULL); |
| #endif /* MBEDTLS_HAVE_TIME */ |
| |
| return ret; |
| } |
| |
| /* |
| * ssl_tls13_write_server_hello_supported_versions_ext (): |
| * |
| * struct { |
| * ProtocolVersion selected_version; |
| * } SupportedVersions; |
| */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_write_server_hello_supported_versions_ext( |
| mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| unsigned char *end, |
| size_t *out_len) |
| { |
| *out_len = 0; |
| |
| MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, write selected version")); |
| |
| /* Check if we have space to write the extension: |
| * - extension_type (2 bytes) |
| * - extension_data_length (2 bytes) |
| * - selected_version (2 bytes) |
| */ |
| MBEDTLS_SSL_CHK_BUF_PTR(buf, end, 6); |
| |
| MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS, buf, 0); |
| |
| MBEDTLS_PUT_UINT16_BE(2, buf, 2); |
| |
| mbedtls_ssl_write_version(buf + 4, |
| ssl->conf->transport, |
| ssl->tls_version); |
| |
| MBEDTLS_SSL_DEBUG_MSG(3, ("supported version: [%04x]", |
| ssl->tls_version)); |
| |
| *out_len = 6; |
| |
| mbedtls_ssl_tls13_set_hs_sent_ext_mask( |
| ssl, MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS); |
| |
| return 0; |
| } |
| |
| |
| |
| /* Generate and export a single key share. For hybrid KEMs, this can |
| * be called multiple times with the different components of the hybrid. */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_generate_and_write_key_share(mbedtls_ssl_context *ssl, |
| uint16_t named_group, |
| unsigned char *buf, |
| unsigned char *end, |
| size_t *out_len) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| *out_len = 0; |
| |
| #if defined(MBEDTLS_ECDH_C) |
| if (mbedtls_ssl_tls13_named_group_is_ecdhe(named_group)) { |
| ret = mbedtls_ssl_tls13_generate_and_write_ecdh_key_exchange( |
| ssl, named_group, buf, end, out_len); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET( |
| 1, "mbedtls_ssl_tls13_generate_and_write_ecdh_key_exchange", |
| ret); |
| return ret; |
| } |
| } else |
| #endif /* MBEDTLS_ECDH_C */ |
| if (0 /* Other kinds of KEMs */) { |
| } else { |
| ((void) ssl); |
| ((void) named_group); |
| ((void) buf); |
| ((void) end); |
| ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR; |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * ssl_tls13_write_key_share_ext |
| * |
| * Structure of key_share extension in ServerHello: |
| * |
| * struct { |
| * NamedGroup group; |
| * opaque key_exchange<1..2^16-1>; |
| * } KeyShareEntry; |
| * struct { |
| * KeyShareEntry server_share; |
| * } KeyShareServerHello; |
| */ |
| 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) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *p = buf; |
| uint16_t group = ssl->handshake->offered_group_id; |
| unsigned char *server_share = buf + 4; |
| size_t key_exchange_length; |
| |
| *out_len = 0; |
| |
| MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, adding key share extension")); |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("server hello, write selected_group: %s (%04x)", |
| mbedtls_ssl_named_group_to_str(group), |
| group)); |
| |
| /* Check if we have space for header and length fields: |
| * - extension_type (2 bytes) |
| * - extension_data_length (2 bytes) |
| * - group (2 bytes) |
| * - key_exchange_length (2 bytes) |
| */ |
| MBEDTLS_SSL_CHK_BUF_PTR(p, end, 8); |
| MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_KEY_SHARE, p, 0); |
| MBEDTLS_PUT_UINT16_BE(group, server_share, 0); |
| p += 8; |
| |
| /* When we introduce PQC-ECDHE hybrids, we'll want to call this |
| * function multiple times. */ |
| ret = ssl_tls13_generate_and_write_key_share( |
| ssl, group, server_share + 4, end, &key_exchange_length); |
| if (ret != 0) { |
| return ret; |
| } |
| p += key_exchange_length; |
| |
| MBEDTLS_PUT_UINT16_BE(key_exchange_length, server_share + 2, 0); |
| |
| MBEDTLS_PUT_UINT16_BE(p - server_share, buf, 2); |
| |
| *out_len = p - buf; |
| |
| mbedtls_ssl_tls13_set_hs_sent_ext_mask(ssl, MBEDTLS_TLS_EXT_KEY_SHARE); |
| |
| return 0; |
| } |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_write_hrr_key_share_ext(mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| unsigned char *end, |
| size_t *out_len) |
| { |
| uint16_t selected_group = ssl->handshake->hrr_selected_group; |
| /* key_share Extension |
| * |
| * struct { |
| * select (Handshake.msg_type) { |
| * ... |
| * case hello_retry_request: |
| * NamedGroup selected_group; |
| * ... |
| * }; |
| * } KeyShare; |
| */ |
| |
| *out_len = 0; |
| |
| /* |
| * For a pure PSK key exchange, there is no group to agree upon. The purpose |
| * of the HRR is then to transmit a cookie to force the client to demonstrate |
| * reachability at their apparent network address (primarily useful for DTLS). |
| */ |
| if (!mbedtls_ssl_tls13_key_exchange_mode_with_ephemeral(ssl)) { |
| return 0; |
| } |
| |
| /* We should only send the key_share extension if the client's initial |
| * key share was not acceptable. */ |
| if (ssl->handshake->offered_group_id != 0) { |
| MBEDTLS_SSL_DEBUG_MSG(4, ("Skip key_share extension in HRR")); |
| return 0; |
| } |
| |
| if (selected_group == 0) { |
| MBEDTLS_SSL_DEBUG_MSG(1, ("no matching named group found")); |
| return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; |
| } |
| |
| /* Check if we have enough space: |
| * - extension_type (2 bytes) |
| * - extension_data_length (2 bytes) |
| * - selected_group (2 bytes) |
| */ |
| MBEDTLS_SSL_CHK_BUF_PTR(buf, end, 6); |
| |
| MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_KEY_SHARE, buf, 0); |
| MBEDTLS_PUT_UINT16_BE(2, buf, 2); |
| MBEDTLS_PUT_UINT16_BE(selected_group, buf, 4); |
| |
| MBEDTLS_SSL_DEBUG_MSG(3, |
| ("HRR selected_group: %s (%x)", |
| mbedtls_ssl_named_group_to_str(selected_group), |
| selected_group)); |
| |
| *out_len = 6; |
| |
| mbedtls_ssl_tls13_set_hs_sent_ext_mask(ssl, MBEDTLS_TLS_EXT_KEY_SHARE); |
| |
| return 0; |
| } |
| |
| /* |
| * Structure of ServerHello message: |
| * |
| * struct { |
| * ProtocolVersion legacy_version = 0x0303; // TLS v1.2 |
| * 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_write_server_hello_body(mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| unsigned char *end, |
| size_t *out_len, |
| int is_hrr) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *p = buf; |
| unsigned char *p_extensions_len; |
| size_t output_len; |
| |
| *out_len = 0; |
| ssl->handshake->sent_extensions = MBEDTLS_SSL_EXT_MASK_NONE; |
| |
| /* ... |
| * ProtocolVersion legacy_version = 0x0303; // TLS 1.2 |
| * ... |
| * with ProtocolVersion defined as: |
| * uint16 ProtocolVersion; |
| */ |
| MBEDTLS_SSL_CHK_BUF_PTR(p, end, 2); |
| MBEDTLS_PUT_UINT16_BE(0x0303, p, 0); |
| p += 2; |
| |
| /* ... |
| * Random random; |
| * ... |
| * with Random defined as: |
| * opaque Random[MBEDTLS_SERVER_HELLO_RANDOM_LEN]; |
| */ |
| MBEDTLS_SSL_CHK_BUF_PTR(p, end, MBEDTLS_SERVER_HELLO_RANDOM_LEN); |
| if (is_hrr) { |
| memcpy(p, mbedtls_ssl_tls13_hello_retry_request_magic, |
| MBEDTLS_SERVER_HELLO_RANDOM_LEN); |
| } else { |
| memcpy(p, &ssl->handshake->randbytes[MBEDTLS_CLIENT_HELLO_RANDOM_LEN], |
| 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>; |
| * ... |
| */ |
| MBEDTLS_SSL_CHK_BUF_PTR(p, end, 1 + ssl->session_negotiate->id_len); |
| *p++ = (unsigned char) ssl->session_negotiate->id_len; |
| if (ssl->session_negotiate->id_len > 0) { |
| memcpy(p, &ssl->session_negotiate->id[0], |
| ssl->session_negotiate->id_len); |
| p += ssl->session_negotiate->id_len; |
| |
| MBEDTLS_SSL_DEBUG_BUF(3, "session id", ssl->session_negotiate->id, |
| ssl->session_negotiate->id_len); |
| } |
| |
| /* ... |
| * CipherSuite cipher_suite; |
| * ... |
| * with CipherSuite defined as: |
| * uint8 CipherSuite[2]; |
| */ |
| MBEDTLS_SSL_CHK_BUF_PTR(p, end, 2); |
| MBEDTLS_PUT_UINT16_BE(ssl->session_negotiate->ciphersuite, p, 0); |
| p += 2; |
| MBEDTLS_SSL_DEBUG_MSG(3, |
| ("server hello, chosen ciphersuite: %s ( id=%d )", |
| mbedtls_ssl_get_ciphersuite_name( |
| ssl->session_negotiate->ciphersuite), |
| ssl->session_negotiate->ciphersuite)); |
| |
| /* ... |
| * uint8 legacy_compression_method = 0; |
| * ... |
| */ |
| MBEDTLS_SSL_CHK_BUF_PTR(p, end, 1); |
| *p++ = MBEDTLS_SSL_COMPRESS_NULL; |
| |
| /* ... |
| * Extension extensions<6..2^16-1>; |
| * ... |
| * struct { |
| * ExtensionType extension_type; (2 bytes) |
| * opaque extension_data<0..2^16-1>; |
| * } Extension; |
| */ |
| MBEDTLS_SSL_CHK_BUF_PTR(p, end, 2); |
| p_extensions_len = p; |
| p += 2; |
| |
| if ((ret = ssl_tls13_write_server_hello_supported_versions_ext( |
| ssl, p, end, &output_len)) != 0) { |
| MBEDTLS_SSL_DEBUG_RET( |
| 1, "ssl_tls13_write_server_hello_supported_versions_ext", ret); |
| return ret; |
| } |
| p += output_len; |
| |
| if (mbedtls_ssl_tls13_key_exchange_mode_with_ephemeral(ssl)) { |
| if (is_hrr) { |
| ret = ssl_tls13_write_hrr_key_share_ext(ssl, p, end, &output_len); |
| } else { |
| ret = ssl_tls13_write_key_share_ext(ssl, p, end, &output_len); |
| } |
| if (ret != 0) { |
| return ret; |
| } |
| p += output_len; |
| } |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) |
| if (!is_hrr && mbedtls_ssl_tls13_key_exchange_mode_with_psk(ssl)) { |
| ret = ssl_tls13_write_server_pre_shared_key_ext(ssl, p, end, &output_len); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, "ssl_tls13_write_server_pre_shared_key_ext", |
| ret); |
| return ret; |
| } |
| p += output_len; |
| } |
| #endif |
| |
| MBEDTLS_PUT_UINT16_BE(p - p_extensions_len - 2, p_extensions_len, 0); |
| |
| MBEDTLS_SSL_DEBUG_BUF(4, "server hello extensions", |
| p_extensions_len, p - p_extensions_len); |
| |
| *out_len = p - buf; |
| |
| MBEDTLS_SSL_DEBUG_BUF(3, "server hello", buf, *out_len); |
| |
| MBEDTLS_SSL_PRINT_EXTS( |
| 3, is_hrr ? MBEDTLS_SSL_TLS1_3_HS_HELLO_RETRY_REQUEST : |
| MBEDTLS_SSL_HS_SERVER_HELLO, |
| ssl->handshake->sent_extensions); |
| |
| return ret; |
| } |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_finalize_server_hello(mbedtls_ssl_context *ssl) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| ret = mbedtls_ssl_tls13_compute_handshake_transform(ssl); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, |
| "mbedtls_ssl_tls13_compute_handshake_transform", |
| ret); |
| return ret; |
| } |
| |
| return ret; |
| } |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_write_server_hello(mbedtls_ssl_context *ssl) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *buf; |
| size_t buf_len, msg_len; |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("=> write server hello")); |
| |
| MBEDTLS_SSL_PROC_CHK(ssl_tls13_prepare_server_hello(ssl)); |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_start_handshake_msg(ssl, |
| MBEDTLS_SSL_HS_SERVER_HELLO, &buf, |
| &buf_len)); |
| |
| MBEDTLS_SSL_PROC_CHK(ssl_tls13_write_server_hello_body(ssl, buf, |
| buf + buf_len, |
| &msg_len, |
| 0)); |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_add_hs_msg_to_checksum( |
| ssl, MBEDTLS_SSL_HS_SERVER_HELLO, buf, msg_len)); |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_finish_handshake_msg( |
| ssl, buf_len, msg_len)); |
| |
| MBEDTLS_SSL_PROC_CHK(ssl_tls13_finalize_server_hello(ssl)); |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE) |
| /* The server sends a dummy change_cipher_spec record immediately |
| * after its first handshake message. This may either be after |
| * a ServerHello or a HelloRetryRequest. |
| */ |
| mbedtls_ssl_handshake_set_state( |
| ssl, MBEDTLS_SSL_SERVER_CCS_AFTER_SERVER_HELLO); |
| #else |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_ENCRYPTED_EXTENSIONS); |
| #endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */ |
| |
| cleanup: |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("<= write server hello")); |
| return ret; |
| } |
| |
| |
| /* |
| * Handler for MBEDTLS_SSL_HELLO_RETRY_REQUEST |
| */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_prepare_hello_retry_request(mbedtls_ssl_context *ssl) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| if (ssl->handshake->hello_retry_request_count > 0) { |
| MBEDTLS_SSL_DEBUG_MSG(1, ("Too many HRRs")); |
| MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE, |
| MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE); |
| return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; |
| } |
| |
| /* |
| * Create stateless transcript hash for HRR |
| */ |
| MBEDTLS_SSL_DEBUG_MSG(4, ("Reset transcript for HRR")); |
| ret = mbedtls_ssl_reset_transcript_for_hrr(ssl); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_reset_transcript_for_hrr", ret); |
| return ret; |
| } |
| mbedtls_ssl_session_reset_msg_layer(ssl, 0); |
| |
| return 0; |
| } |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_write_hello_retry_request(mbedtls_ssl_context *ssl) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *buf; |
| size_t buf_len, msg_len; |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("=> write hello retry request")); |
| |
| MBEDTLS_SSL_PROC_CHK(ssl_tls13_prepare_hello_retry_request(ssl)); |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_start_handshake_msg( |
| ssl, MBEDTLS_SSL_HS_SERVER_HELLO, |
| &buf, &buf_len)); |
| |
| MBEDTLS_SSL_PROC_CHK(ssl_tls13_write_server_hello_body(ssl, buf, |
| buf + buf_len, |
| &msg_len, |
| 1)); |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_add_hs_msg_to_checksum( |
| ssl, MBEDTLS_SSL_HS_SERVER_HELLO, buf, msg_len)); |
| |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_finish_handshake_msg(ssl, buf_len, |
| msg_len)); |
| |
| ssl->handshake->hello_retry_request_count++; |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE) |
| /* The server sends a dummy change_cipher_spec record immediately |
| * after its first handshake message. This may either be after |
| * a ServerHello or a HelloRetryRequest. |
| */ |
| mbedtls_ssl_handshake_set_state( |
| ssl, MBEDTLS_SSL_SERVER_CCS_AFTER_HELLO_RETRY_REQUEST); |
| #else |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_HELLO); |
| #endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */ |
| |
| cleanup: |
| MBEDTLS_SSL_DEBUG_MSG(2, ("<= write hello retry request")); |
| return ret; |
| } |
| |
| /* |
| * Handler for MBEDTLS_SSL_ENCRYPTED_EXTENSIONS |
| */ |
| |
| /* |
| * struct { |
| * Extension extensions<0..2 ^ 16 - 1>; |
| * } EncryptedExtensions; |
| * |
| */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_write_encrypted_extensions_body(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 extensions_len = 0; |
| unsigned char *p_extensions_len; |
| size_t output_len; |
| |
| *out_len = 0; |
| |
| MBEDTLS_SSL_CHK_BUF_PTR(p, end, 2); |
| p_extensions_len = p; |
| p += 2; |
| |
| ((void) ssl); |
| ((void) ret); |
| ((void) output_len); |
| |
| #if defined(MBEDTLS_SSL_ALPN) |
| ret = mbedtls_ssl_write_alpn_ext(ssl, p, end, &output_len); |
| if (ret != 0) { |
| return ret; |
| } |
| p += output_len; |
| #endif /* MBEDTLS_SSL_ALPN */ |
| |
| extensions_len = (p - p_extensions_len) - 2; |
| MBEDTLS_PUT_UINT16_BE(extensions_len, p_extensions_len, 0); |
| |
| *out_len = p - buf; |
| |
| MBEDTLS_SSL_DEBUG_BUF(4, "encrypted extensions", buf, *out_len); |
| |
| MBEDTLS_SSL_PRINT_EXTS( |
| 3, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS, ssl->handshake->sent_extensions); |
| |
| return 0; |
| } |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_write_encrypted_extensions(mbedtls_ssl_context *ssl) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *buf; |
| size_t buf_len, msg_len; |
| |
| mbedtls_ssl_set_outbound_transform(ssl, |
| ssl->handshake->transform_handshake); |
| MBEDTLS_SSL_DEBUG_MSG( |
| 3, ("switching to handshake transform for outbound data")); |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("=> write encrypted extensions")); |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_start_handshake_msg(ssl, |
| MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS, &buf, |
| &buf_len)); |
| |
| MBEDTLS_SSL_PROC_CHK(ssl_tls13_write_encrypted_extensions_body( |
| ssl, buf, buf + buf_len, &msg_len)); |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_add_hs_msg_to_checksum( |
| ssl, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS, buf, msg_len)); |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_finish_handshake_msg( |
| ssl, buf_len, msg_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 |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_SERVER_FINISHED); |
| #endif |
| |
| cleanup: |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("<= write encrypted extensions")); |
| return ret; |
| } |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED) |
| #define SSL_CERTIFICATE_REQUEST_SEND_REQUEST 0 |
| #define SSL_CERTIFICATE_REQUEST_SKIP 1 |
| /* Coordination: |
| * Check whether a CertificateRequest message should be written. |
| * Returns a negative code on failure, or |
| * - SSL_CERTIFICATE_REQUEST_SEND_REQUEST |
| * - SSL_CERTIFICATE_REQUEST_SKIP |
| * indicating if the writing of the CertificateRequest |
| * should be skipped or not. |
| */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_certificate_request_coordinate(mbedtls_ssl_context *ssl) |
| { |
| int authmode; |
| |
| #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) |
| if (ssl->handshake->sni_authmode != MBEDTLS_SSL_VERIFY_UNSET) { |
| authmode = ssl->handshake->sni_authmode; |
| } else |
| #endif |
| authmode = ssl->conf->authmode; |
| |
| if (authmode == MBEDTLS_SSL_VERIFY_NONE) { |
| ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_SKIP_VERIFY; |
| return SSL_CERTIFICATE_REQUEST_SKIP; |
| } |
| |
| ssl->handshake->certificate_request_sent = 1; |
| |
| return SSL_CERTIFICATE_REQUEST_SEND_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_write_certificate_request_body(mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| const unsigned char *end, |
| size_t *out_len) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *p = buf; |
| size_t output_len = 0; |
| unsigned char *p_extensions_len; |
| |
| *out_len = 0; |
| |
| /* Check if we have enough space: |
| * - certificate_request_context (1 byte) |
| * - extensions length (2 bytes) |
| */ |
| MBEDTLS_SSL_CHK_BUF_PTR(p, end, 3); |
| |
| /* |
| * Write certificate_request_context |
| */ |
| /* |
| * We use a zero length context for the normal handshake |
| * messages. For post-authentication handshake messages |
| * this request context would be set to a non-zero value. |
| */ |
| *p++ = 0x0; |
| |
| /* |
| * Write extensions |
| */ |
| /* The extensions must contain the signature_algorithms. */ |
| p_extensions_len = p; |
| p += 2; |
| ret = mbedtls_ssl_write_sig_alg_ext(ssl, p, end, &output_len); |
| if (ret != 0) { |
| return ret; |
| } |
| |
| p += output_len; |
| MBEDTLS_PUT_UINT16_BE(p - p_extensions_len - 2, p_extensions_len, 0); |
| |
| *out_len = p - buf; |
| |
| MBEDTLS_SSL_PRINT_EXTS( |
| 3, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, ssl->handshake->sent_extensions); |
| |
| return 0; |
| } |
| |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_write_certificate_request(mbedtls_ssl_context *ssl) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("=> write certificate request")); |
| |
| MBEDTLS_SSL_PROC_CHK_NEG(ssl_tls13_certificate_request_coordinate(ssl)); |
| |
| if (ret == SSL_CERTIFICATE_REQUEST_SEND_REQUEST) { |
| unsigned char *buf; |
| size_t buf_len, msg_len; |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_start_handshake_msg(ssl, |
| MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, |
| &buf, &buf_len)); |
| |
| MBEDTLS_SSL_PROC_CHK(ssl_tls13_write_certificate_request_body( |
| ssl, buf, buf + buf_len, &msg_len)); |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_add_hs_msg_to_checksum( |
| ssl, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, buf, msg_len)); |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_finish_handshake_msg( |
| ssl, buf_len, msg_len)); |
| } else if (ret == SSL_CERTIFICATE_REQUEST_SKIP) { |
| MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip write certificate request")); |
| 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, ("<= write certificate request")); |
| return ret; |
| } |
| |
| /* |
| * Handler for MBEDTLS_SSL_SERVER_CERTIFICATE |
| */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_write_server_certificate(mbedtls_ssl_context *ssl) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| #if defined(MBEDTLS_X509_CRT_PARSE_C) |
| if ((ssl_tls13_pick_key_cert(ssl) != 0) || |
| mbedtls_ssl_own_cert(ssl) == NULL) { |
| MBEDTLS_SSL_DEBUG_MSG(2, ("No certificate available.")); |
| MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE, |
| MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE); |
| return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; |
| } |
| #endif /* MBEDTLS_X509_CRT_PARSE_C */ |
| |
| ret = mbedtls_ssl_tls13_write_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_write_certificate_verify(mbedtls_ssl_context *ssl) |
| { |
| int ret = mbedtls_ssl_tls13_write_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_write_server_finished(mbedtls_ssl_context *ssl) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| ret = mbedtls_ssl_tls13_write_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; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG(1, ("Switch to handshake keys for inbound traffic")); |
| mbedtls_ssl_set_inbound_transform(ssl, ssl->handshake->transform_handshake); |
| |
| if (ssl->handshake->certificate_request_sent) { |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE); |
| } else { |
| MBEDTLS_SSL_DEBUG_MSG(2, ("skip parse certificate")); |
| MBEDTLS_SSL_DEBUG_MSG(2, ("skip parse certificate verify")); |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_FINISHED); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Handler for MBEDTLS_SSL_CLIENT_FINISHED |
| */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_process_client_finished(mbedtls_ssl_context *ssl) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| ret = mbedtls_ssl_tls13_process_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); |
| } |
| |
| 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_DEBUG_MSG(2, ("handshake: done")); |
| |
| mbedtls_ssl_tls13_handshake_wrapup(ssl); |
| |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) && \ |
| defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) |
| /* TODO: Remove the check of SOME_PSK_ENABLED since SESSION_TICKETS requires |
| * SOME_PSK_ENABLED to be enabled. Here is just to make CI happy. It is |
| * expected to be resolved with issue#6395. |
| */ |
| /* Sent NewSessionTicket message only when client supports PSK */ |
| if (mbedtls_ssl_tls13_some_psk_enabled(ssl)) { |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_TLS1_3_NEW_SESSION_TICKET); |
| } else |
| #endif |
| { |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_HANDSHAKE_OVER); |
| } |
| return 0; |
| } |
| |
| /* |
| * Handler for MBEDTLS_SSL_TLS1_3_NEW_SESSION_TICKET |
| */ |
| #define SSL_NEW_SESSION_TICKET_SKIP 0 |
| #define SSL_NEW_SESSION_TICKET_WRITE 1 |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_write_new_session_ticket_coordinate(mbedtls_ssl_context *ssl) |
| { |
| /* Check whether the use of session tickets is enabled */ |
| if (ssl->conf->f_ticket_write == NULL) { |
| MBEDTLS_SSL_DEBUG_MSG(2, ("NewSessionTicket: disabled," |
| " callback is not set")); |
| return SSL_NEW_SESSION_TICKET_SKIP; |
| } |
| if (ssl->conf->new_session_tickets_count == 0) { |
| MBEDTLS_SSL_DEBUG_MSG(2, ("NewSessionTicket: disabled," |
| " configured count is zero")); |
| return SSL_NEW_SESSION_TICKET_SKIP; |
| } |
| |
| if (ssl->handshake->new_session_tickets_count == 0) { |
| MBEDTLS_SSL_DEBUG_MSG(2, ("NewSessionTicket: all tickets have " |
| "been sent.")); |
| return SSL_NEW_SESSION_TICKET_SKIP; |
| } |
| |
| return SSL_NEW_SESSION_TICKET_WRITE; |
| } |
| |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_prepare_new_session_ticket(mbedtls_ssl_context *ssl, |
| unsigned char *ticket_nonce, |
| size_t ticket_nonce_size) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| mbedtls_ssl_session *session = ssl->session; |
| mbedtls_ssl_ciphersuite_t *ciphersuite_info; |
| psa_algorithm_t psa_hash_alg; |
| int hash_length; |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("=> prepare NewSessionTicket msg")); |
| |
| #if defined(MBEDTLS_HAVE_TIME) |
| session->start = mbedtls_time(NULL); |
| #endif |
| |
| /* Set ticket_flags depends on the advertised psk key exchange mode */ |
| mbedtls_ssl_session_clear_ticket_flags( |
| session, MBEDTLS_SSL_TLS1_3_TICKET_FLAGS_MASK); |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED) |
| mbedtls_ssl_session_set_ticket_flags( |
| session, ssl->handshake->tls13_kex_modes); |
| #endif |
| MBEDTLS_SSL_PRINT_TICKET_FLAGS(4, session->ticket_flags); |
| |
| /* Generate ticket_age_add */ |
| if ((ret = ssl->conf->f_rng(ssl->conf->p_rng, |
| (unsigned char *) &session->ticket_age_add, |
| sizeof(session->ticket_age_add)) != 0)) { |
| MBEDTLS_SSL_DEBUG_RET(1, "generate_ticket_age_add", ret); |
| return ret; |
| } |
| MBEDTLS_SSL_DEBUG_MSG(3, ("ticket_age_add: %u", |
| (unsigned int) session->ticket_age_add)); |
| |
| /* Generate ticket_nonce */ |
| ret = ssl->conf->f_rng(ssl->conf->p_rng, ticket_nonce, ticket_nonce_size); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, "generate_ticket_nonce", ret); |
| return ret; |
| } |
| MBEDTLS_SSL_DEBUG_BUF(3, "ticket_nonce:", |
| ticket_nonce, ticket_nonce_size); |
| |
| ciphersuite_info = |
| (mbedtls_ssl_ciphersuite_t *) ssl->handshake->ciphersuite_info; |
| psa_hash_alg = mbedtls_psa_translate_md(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; |
| } |
| |
| /* In this code the psk key length equals the length of the hash */ |
| session->resumption_key_len = hash_length; |
| session->ciphersuite = ciphersuite_info->id; |
| |
| /* 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_size, |
| session->resumption_key, |
| hash_length); |
| |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(2, |
| "Creating the ticket-resumed PSK failed", |
| ret); |
| return ret; |
| } |
| MBEDTLS_SSL_DEBUG_BUF(3, "Ticket-resumed PSK", |
| session->resumption_key, |
| session->resumption_key_len); |
| |
| MBEDTLS_SSL_DEBUG_BUF(3, "resumption_master_secret", |
| session->app_secrets.resumption_master_secret, |
| hash_length); |
| |
| return 0; |
| } |
| |
| /* This function creates a NewSessionTicket message in the following format: |
| * |
| * 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; |
| * |
| * The ticket inside the NewSessionTicket message is an encrypted container |
| * carrying the necessary information so that the server is later able to |
| * re-start the communication. |
| * |
| * The following fields are placed inside the ticket by the |
| * f_ticket_write() function: |
| * |
| * - creation time (start) |
| * - flags (flags) |
| * - age add (ticket_age_add) |
| * - key (key) |
| * - key length (key_len) |
| * - ciphersuite (ciphersuite) |
| */ |
| MBEDTLS_CHECK_RETURN_CRITICAL |
| static int ssl_tls13_write_new_session_ticket_body(mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| unsigned char *end, |
| size_t *out_len, |
| unsigned char *ticket_nonce, |
| size_t ticket_nonce_size) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| unsigned char *p = buf; |
| mbedtls_ssl_session *session = ssl->session; |
| size_t ticket_len; |
| uint32_t ticket_lifetime; |
| |
| *out_len = 0; |
| MBEDTLS_SSL_DEBUG_MSG(2, ("=> write NewSessionTicket msg")); |
| |
| /* |
| * ticket_lifetime 4 bytes |
| * ticket_age_add 4 bytes |
| * ticket_nonce 1 + ticket_nonce_size bytes |
| * ticket >=2 bytes |
| */ |
| MBEDTLS_SSL_CHK_BUF_PTR(p, end, 4 + 4 + 1 + ticket_nonce_size + 2); |
| |
| /* Generate ticket and ticket_lifetime */ |
| ret = ssl->conf->f_ticket_write(ssl->conf->p_ticket, |
| session, |
| p + 9 + ticket_nonce_size + 2, |
| end, |
| &ticket_len, |
| &ticket_lifetime); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, "write_ticket", ret); |
| return ret; |
| } |
| /* RFC 8446 4.6.1 |
| * ticket_lifetime: Indicates the lifetime in seconds as a 32-bit |
| * unsigned integer in network byte order from the time of ticket |
| * issuance. Servers MUST NOT use any value greater than |
| * 604800 seconds (7 days). The value of zero indicates that the |
| * ticket should be discarded immediately. Clients MUST NOT cache |
| * tickets for longer than 7 days, regardless of the ticket_lifetime, |
| * and MAY delete tickets earlier based on local policy. A server |
| * MAY treat a ticket as valid for a shorter period of time than what |
| * is stated in the ticket_lifetime. |
| */ |
| if (ticket_lifetime > 604800) { |
| ticket_lifetime = 604800; |
| } |
| MBEDTLS_PUT_UINT32_BE(ticket_lifetime, p, 0); |
| MBEDTLS_SSL_DEBUG_MSG(3, ("ticket_lifetime: %u", |
| (unsigned int) ticket_lifetime)); |
| |
| /* Write ticket_age_add */ |
| MBEDTLS_PUT_UINT32_BE(session->ticket_age_add, p, 4); |
| MBEDTLS_SSL_DEBUG_MSG(3, ("ticket_age_add: %u", |
| (unsigned int) session->ticket_age_add)); |
| |
| /* Write ticket_nonce */ |
| p[8] = (unsigned char) ticket_nonce_size; |
| if (ticket_nonce_size > 0) { |
| memcpy(p + 9, ticket_nonce, ticket_nonce_size); |
| } |
| p += 9 + ticket_nonce_size; |
| |
| /* Write ticket */ |
| MBEDTLS_PUT_UINT16_BE(ticket_len, p, 0); |
| p += 2; |
| MBEDTLS_SSL_DEBUG_BUF(4, "ticket", p, ticket_len); |
| p += ticket_len; |
| |
| /* Ticket Extensions |
| * |
| * Note: We currently don't have any extensions. |
| * Set length to zero. |
| */ |
| ssl->handshake->sent_extensions = MBEDTLS_SSL_EXT_MASK_NONE; |
| |
| MBEDTLS_SSL_CHK_BUF_PTR(p, end, 2); |
| MBEDTLS_PUT_UINT16_BE(0, p, 0); |
| p += 2; |
| |
| *out_len = p - buf; |
| MBEDTLS_SSL_DEBUG_BUF(4, "ticket", buf, *out_len); |
| MBEDTLS_SSL_DEBUG_MSG(2, ("<= write new session ticket")); |
| |
| MBEDTLS_SSL_PRINT_EXTS( |
| 3, MBEDTLS_SSL_HS_NEW_SESSION_TICKET, ssl->handshake->sent_extensions); |
| |
| return 0; |
| } |
| |
| /* |
| * Handler for MBEDTLS_SSL_TLS1_3_NEW_SESSION_TICKET |
| */ |
| static int ssl_tls13_write_new_session_ticket(mbedtls_ssl_context *ssl) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| MBEDTLS_SSL_PROC_CHK_NEG(ssl_tls13_write_new_session_ticket_coordinate(ssl)); |
| |
| if (ret == SSL_NEW_SESSION_TICKET_WRITE) { |
| unsigned char ticket_nonce[MBEDTLS_SSL_TLS1_3_TICKET_NONCE_LENGTH]; |
| unsigned char *buf; |
| size_t buf_len, msg_len; |
| |
| MBEDTLS_SSL_PROC_CHK(ssl_tls13_prepare_new_session_ticket( |
| ssl, ticket_nonce, sizeof(ticket_nonce))); |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_start_handshake_msg(ssl, |
| MBEDTLS_SSL_HS_NEW_SESSION_TICKET, |
| &buf, &buf_len)); |
| |
| MBEDTLS_SSL_PROC_CHK(ssl_tls13_write_new_session_ticket_body( |
| ssl, buf, buf + buf_len, &msg_len, |
| ticket_nonce, sizeof(ticket_nonce))); |
| |
| MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_finish_handshake_msg( |
| ssl, buf_len, msg_len)); |
| |
| /* Limit session tickets count to one when resumption connection. |
| * |
| * See document of mbedtls_ssl_conf_new_session_tickets. |
| */ |
| if (ssl->handshake->resume == 1) { |
| ssl->handshake->new_session_tickets_count = 0; |
| } else { |
| ssl->handshake->new_session_tickets_count--; |
| } |
| |
| mbedtls_ssl_handshake_set_state( |
| ssl, MBEDTLS_SSL_TLS1_3_NEW_SESSION_TICKET_FLUSH); |
| } else { |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_HANDSHAKE_OVER); |
| } |
| |
| cleanup: |
| |
| return ret; |
| } |
| #endif /* MBEDTLS_SSL_SESSION_TICKETS */ |
| |
| /* |
| * TLS 1.3 State Machine -- server side |
| */ |
| int mbedtls_ssl_tls13_handshake_server_step(mbedtls_ssl_context *ssl) |
| { |
| int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; |
| |
| if (ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER || ssl->handshake == NULL) { |
| return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; |
| } |
| |
| MBEDTLS_SSL_DEBUG_MSG(2, ("tls13 server state: %s(%d)", |
| mbedtls_ssl_states_str(ssl->state), |
| ssl->state)); |
| |
| switch (ssl->state) { |
| /* start state */ |
| case MBEDTLS_SSL_HELLO_REQUEST: |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_HELLO); |
| ret = 0; |
| break; |
| |
| case MBEDTLS_SSL_CLIENT_HELLO: |
| ret = ssl_tls13_process_client_hello(ssl); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, "ssl_tls13_process_client_hello", ret); |
| } |
| break; |
| |
| case MBEDTLS_SSL_HELLO_RETRY_REQUEST: |
| ret = ssl_tls13_write_hello_retry_request(ssl); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, "ssl_tls13_write_hello_retry_request", ret); |
| return ret; |
| } |
| break; |
| |
| case MBEDTLS_SSL_SERVER_HELLO: |
| ret = ssl_tls13_write_server_hello(ssl); |
| break; |
| |
| case MBEDTLS_SSL_ENCRYPTED_EXTENSIONS: |
| ret = ssl_tls13_write_encrypted_extensions(ssl); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, "ssl_tls13_write_encrypted_extensions", ret); |
| return ret; |
| } |
| break; |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED) |
| case MBEDTLS_SSL_CERTIFICATE_REQUEST: |
| ret = ssl_tls13_write_certificate_request(ssl); |
| break; |
| |
| case MBEDTLS_SSL_SERVER_CERTIFICATE: |
| ret = ssl_tls13_write_server_certificate(ssl); |
| break; |
| |
| case MBEDTLS_SSL_CERTIFICATE_VERIFY: |
| ret = ssl_tls13_write_certificate_verify(ssl); |
| break; |
| #endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED */ |
| |
| /* |
| * Injection of dummy-CCS's for middlebox compatibility |
| */ |
| #if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE) |
| case MBEDTLS_SSL_SERVER_CCS_AFTER_HELLO_RETRY_REQUEST: |
| ret = mbedtls_ssl_tls13_write_change_cipher_spec(ssl); |
| if (ret == 0) { |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_CLIENT_HELLO); |
| } |
| break; |
| |
| case MBEDTLS_SSL_SERVER_CCS_AFTER_SERVER_HELLO: |
| ret = mbedtls_ssl_tls13_write_change_cipher_spec(ssl); |
| if (ret == 0) { |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_ENCRYPTED_EXTENSIONS); |
| } |
| break; |
| #endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */ |
| |
| case MBEDTLS_SSL_SERVER_FINISHED: |
| ret = ssl_tls13_write_server_finished(ssl); |
| break; |
| |
| case MBEDTLS_SSL_CLIENT_FINISHED: |
| ret = ssl_tls13_process_client_finished(ssl); |
| break; |
| |
| case MBEDTLS_SSL_HANDSHAKE_WRAPUP: |
| ret = ssl_tls13_handshake_wrapup(ssl); |
| break; |
| |
| #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED) |
| case MBEDTLS_SSL_CLIENT_CERTIFICATE: |
| ret = mbedtls_ssl_tls13_process_certificate(ssl); |
| if (ret == 0) { |
| if (ssl->session_negotiate->peer_cert != NULL) { |
| mbedtls_ssl_handshake_set_state( |
| ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY); |
| } else { |
| MBEDTLS_SSL_DEBUG_MSG(2, ("skip parse certificate verify")); |
| mbedtls_ssl_handshake_set_state( |
| ssl, MBEDTLS_SSL_CLIENT_FINISHED); |
| } |
| } |
| break; |
| |
| case MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY: |
| ret = mbedtls_ssl_tls13_process_certificate_verify(ssl); |
| if (ret == 0) { |
| mbedtls_ssl_handshake_set_state( |
| ssl, MBEDTLS_SSL_CLIENT_FINISHED); |
| } |
| break; |
| #endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED */ |
| |
| #if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| case MBEDTLS_SSL_TLS1_3_NEW_SESSION_TICKET: |
| ret = ssl_tls13_write_new_session_ticket(ssl); |
| if (ret != 0) { |
| MBEDTLS_SSL_DEBUG_RET(1, |
| "ssl_tls13_write_new_session_ticket ", |
| ret); |
| } |
| break; |
| case MBEDTLS_SSL_TLS1_3_NEW_SESSION_TICKET_FLUSH: |
| /* This state is necessary to do the flush of the New Session |
| * Ticket message written in MBEDTLS_SSL_TLS1_3_NEW_SESSION_TICKET |
| * as part of ssl_prepare_handshake_step. |
| */ |
| ret = 0; |
| |
| if (ssl->handshake->new_session_tickets_count == 0) { |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_HANDSHAKE_OVER); |
| } else { |
| mbedtls_ssl_handshake_set_state(ssl, MBEDTLS_SSL_TLS1_3_NEW_SESSION_TICKET); |
| } |
| break; |
| |
| #endif /* MBEDTLS_SSL_SESSION_TICKETS */ |
| |
| default: |
| MBEDTLS_SSL_DEBUG_MSG(1, ("invalid state %d", ssl->state)); |
| return MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; |
| } |
| |
| return ret; |
| } |
| |
| #endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_PROTO_TLS1_3 */ |