/* * TLS client-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_CLI_C) && defined(MBEDTLS_SSL_PROTO_TLS1_2) #include "mbedtls/platform.h" #include "mbedtls/ssl.h" #include "ssl_client.h" #include "ssl_misc.h" #include "mbedtls/debug.h" #include "mbedtls/error.h" #include "mbedtls/constant_time.h" #if defined(MBEDTLS_USE_PSA_CRYPTO) #include "mbedtls/psa_util.h" #include "psa/crypto.h" #endif /* MBEDTLS_USE_PSA_CRYPTO */ #include #include #if defined(MBEDTLS_HAVE_TIME) #include "mbedtls/platform_time.h" #endif #if defined(MBEDTLS_SSL_SESSION_TICKETS) #include "mbedtls/platform_util.h" #endif #include "hash_info.h" #if defined(MBEDTLS_SSL_RENEGOTIATION) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_write_renegotiation_ext(mbedtls_ssl_context *ssl, unsigned char *buf, const unsigned char *end, size_t *olen) { unsigned char *p = buf; *olen = 0; /* We're always including a TLS_EMPTY_RENEGOTIATION_INFO_SCSV in the * initial ClientHello, in which case also adding the renegotiation * info extension is NOT RECOMMENDED as per RFC 5746 Section 3.4. */ if (ssl->renego_status != MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS) { return 0; } MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding renegotiation extension")); MBEDTLS_SSL_CHK_BUF_PTR(p, end, 5 + ssl->verify_data_len); /* * Secure renegotiation */ MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_RENEGOTIATION_INFO, p, 0); p += 2; *p++ = 0x00; *p++ = MBEDTLS_BYTE_0(ssl->verify_data_len + 1); *p++ = MBEDTLS_BYTE_0(ssl->verify_data_len); memcpy(p, ssl->own_verify_data, ssl->verify_data_len); *olen = 5 + ssl->verify_data_len; return 0; } #endif /* MBEDTLS_SSL_RENEGOTIATION */ #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \ defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_write_supported_point_formats_ext(mbedtls_ssl_context *ssl, unsigned char *buf, const unsigned char *end, size_t *olen) { unsigned char *p = buf; (void) ssl; /* ssl used for debugging only */ *olen = 0; MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding supported_point_formats extension")); MBEDTLS_SSL_CHK_BUF_PTR(p, end, 6); MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS, p, 0); p += 2; *p++ = 0x00; *p++ = 2; *p++ = 1; *p++ = MBEDTLS_ECP_PF_UNCOMPRESSED; *olen = 6; return 0; } #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C || MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_write_ecjpake_kkpp_ext(mbedtls_ssl_context *ssl, unsigned char *buf, const unsigned char *end, size_t *olen) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; unsigned char *p = buf; size_t kkpp_len = 0; *olen = 0; /* Skip costly extension if we can't use EC J-PAKE anyway */ #if defined(MBEDTLS_USE_PSA_CRYPTO) if (ssl->handshake->psa_pake_ctx_is_ok != 1) { return 0; } #else if (mbedtls_ecjpake_check(&ssl->handshake->ecjpake_ctx) != 0) { return 0; } #endif /* MBEDTLS_USE_PSA_CRYPTO */ MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding ecjpake_kkpp extension")); MBEDTLS_SSL_CHK_BUF_PTR(p, end, 4); MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_ECJPAKE_KKPP, p, 0); p += 2; /* * We may need to send ClientHello multiple times for Hello verification. * We don't want to compute fresh values every time (both for performance * and consistency reasons), so cache the extension content. */ if (ssl->handshake->ecjpake_cache == NULL || ssl->handshake->ecjpake_cache_len == 0) { MBEDTLS_SSL_DEBUG_MSG(3, ("generating new ecjpake parameters")); #if defined(MBEDTLS_USE_PSA_CRYPTO) ret = mbedtls_psa_ecjpake_write_round(&ssl->handshake->psa_pake_ctx, p + 2, end - p - 2, &kkpp_len, MBEDTLS_ECJPAKE_ROUND_ONE); if (ret != 0) { psa_destroy_key(ssl->handshake->psa_pake_password); psa_pake_abort(&ssl->handshake->psa_pake_ctx); MBEDTLS_SSL_DEBUG_RET(1, "psa_pake_output", ret); return ret; } #else ret = mbedtls_ecjpake_write_round_one(&ssl->handshake->ecjpake_ctx, p + 2, end - p - 2, &kkpp_len, ssl->conf->f_rng, ssl->conf->p_rng); if (ret != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecjpake_write_round_one", ret); return ret; } #endif /* MBEDTLS_USE_PSA_CRYPTO */ ssl->handshake->ecjpake_cache = mbedtls_calloc(1, kkpp_len); if (ssl->handshake->ecjpake_cache == NULL) { MBEDTLS_SSL_DEBUG_MSG(1, ("allocation failed")); return MBEDTLS_ERR_SSL_ALLOC_FAILED; } memcpy(ssl->handshake->ecjpake_cache, p + 2, kkpp_len); ssl->handshake->ecjpake_cache_len = kkpp_len; } else { MBEDTLS_SSL_DEBUG_MSG(3, ("re-using cached ecjpake parameters")); kkpp_len = ssl->handshake->ecjpake_cache_len; MBEDTLS_SSL_CHK_BUF_PTR(p + 2, end, kkpp_len); memcpy(p + 2, ssl->handshake->ecjpake_cache, kkpp_len); } MBEDTLS_PUT_UINT16_BE(kkpp_len, p, 0); p += 2; *olen = kkpp_len + 4; return 0; } #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_write_cid_ext(mbedtls_ssl_context *ssl, unsigned char *buf, const unsigned char *end, size_t *olen) { unsigned char *p = buf; size_t ext_len; /* * struct { * opaque cid<0..2^8-1>; * } ConnectionId; */ *olen = 0; if (ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM || ssl->negotiate_cid == MBEDTLS_SSL_CID_DISABLED) { return 0; } MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding CID extension")); /* ssl->own_cid_len is at most MBEDTLS_SSL_CID_IN_LEN_MAX * which is at most 255, so the increment cannot overflow. */ MBEDTLS_SSL_CHK_BUF_PTR(p, end, (unsigned) (ssl->own_cid_len + 5)); /* Add extension ID + size */ MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_CID, p, 0); p += 2; ext_len = (size_t) ssl->own_cid_len + 1; MBEDTLS_PUT_UINT16_BE(ext_len, p, 0); p += 2; *p++ = (uint8_t) ssl->own_cid_len; memcpy(p, ssl->own_cid, ssl->own_cid_len); *olen = ssl->own_cid_len + 5; return 0; } #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_write_max_fragment_length_ext(mbedtls_ssl_context *ssl, unsigned char *buf, const unsigned char *end, size_t *olen) { unsigned char *p = buf; *olen = 0; if (ssl->conf->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE) { return 0; } MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding max_fragment_length extension")); MBEDTLS_SSL_CHK_BUF_PTR(p, end, 5); MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH, p, 0); p += 2; *p++ = 0x00; *p++ = 1; *p++ = ssl->conf->mfl_code; *olen = 5; return 0; } #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */ #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_write_encrypt_then_mac_ext(mbedtls_ssl_context *ssl, unsigned char *buf, const unsigned char *end, size_t *olen) { unsigned char *p = buf; *olen = 0; if (ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED) { return 0; } MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding encrypt_then_mac extension")); MBEDTLS_SSL_CHK_BUF_PTR(p, end, 4); MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC, p, 0); p += 2; *p++ = 0x00; *p++ = 0x00; *olen = 4; return 0; } #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_write_extended_ms_ext(mbedtls_ssl_context *ssl, unsigned char *buf, const unsigned char *end, size_t *olen) { unsigned char *p = buf; *olen = 0; if (ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED) { return 0; } MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding extended_master_secret extension")); MBEDTLS_SSL_CHK_BUF_PTR(p, end, 4); MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET, p, 0); p += 2; *p++ = 0x00; *p++ = 0x00; *olen = 4; return 0; } #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_write_session_ticket_ext(mbedtls_ssl_context *ssl, unsigned char *buf, const unsigned char *end, size_t *olen) { unsigned char *p = buf; size_t tlen = ssl->session_negotiate->ticket_len; *olen = 0; if (ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED) { return 0; } MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding session ticket extension")); /* The addition is safe here since the ticket length is 16 bit. */ MBEDTLS_SSL_CHK_BUF_PTR(p, end, 4 + tlen); MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_SESSION_TICKET, p, 0); p += 2; MBEDTLS_PUT_UINT16_BE(tlen, p, 0); p += 2; *olen = 4; if (ssl->session_negotiate->ticket == NULL || tlen == 0) { return 0; } MBEDTLS_SSL_DEBUG_MSG(3, ("sending session ticket of length %" MBEDTLS_PRINTF_SIZET, tlen)); memcpy(p, ssl->session_negotiate->ticket, tlen); *olen += tlen; return 0; } #endif /* MBEDTLS_SSL_SESSION_TICKETS */ #if defined(MBEDTLS_SSL_DTLS_SRTP) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_write_use_srtp_ext(mbedtls_ssl_context *ssl, unsigned char *buf, const unsigned char *end, size_t *olen) { unsigned char *p = buf; size_t protection_profiles_index = 0, ext_len = 0; uint16_t mki_len = 0, profile_value = 0; *olen = 0; if ((ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM) || (ssl->conf->dtls_srtp_profile_list == NULL) || (ssl->conf->dtls_srtp_profile_list_len == 0)) { return 0; } /* RFC 5764 section 4.1.1 * uint8 SRTPProtectionProfile[2]; * * struct { * SRTPProtectionProfiles SRTPProtectionProfiles; * opaque srtp_mki<0..255>; * } UseSRTPData; * SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>; */ if (ssl->conf->dtls_srtp_mki_support == MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED) { mki_len = ssl->dtls_srtp_info.mki_len; } /* Extension length = 2 bytes for profiles length, * ssl->conf->dtls_srtp_profile_list_len * 2 (each profile is 2 bytes length ), * 1 byte for srtp_mki vector length and the mki_len value */ ext_len = 2 + 2 * (ssl->conf->dtls_srtp_profile_list_len) + 1 + mki_len; MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, adding use_srtp extension")); /* Check there is room in the buffer for the extension + 4 bytes * - the extension tag (2 bytes) * - the extension length (2 bytes) */ MBEDTLS_SSL_CHK_BUF_PTR(p, end, ext_len + 4); MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_USE_SRTP, p, 0); p += 2; MBEDTLS_PUT_UINT16_BE(ext_len, p, 0); p += 2; /* protection profile length: 2*(ssl->conf->dtls_srtp_profile_list_len) */ /* micro-optimization: * the list size is limited to MBEDTLS_TLS_SRTP_MAX_PROFILE_LIST_LENGTH * which is lower than 127, so the upper byte of the length is always 0 * For the documentation, the more generic code is left in comments * *p++ = (unsigned char)( ( ( 2 * ssl->conf->dtls_srtp_profile_list_len ) * >> 8 ) & 0xFF ); */ *p++ = 0; *p++ = MBEDTLS_BYTE_0(2 * ssl->conf->dtls_srtp_profile_list_len); for (protection_profiles_index = 0; protection_profiles_index < ssl->conf->dtls_srtp_profile_list_len; protection_profiles_index++) { profile_value = mbedtls_ssl_check_srtp_profile_value (ssl->conf->dtls_srtp_profile_list[protection_profiles_index]); if (profile_value != MBEDTLS_TLS_SRTP_UNSET) { MBEDTLS_SSL_DEBUG_MSG(3, ("ssl_write_use_srtp_ext, add profile: %04x", profile_value)); MBEDTLS_PUT_UINT16_BE(profile_value, p, 0); p += 2; } else { /* * Note: we shall never arrive here as protection profiles * is checked by mbedtls_ssl_conf_dtls_srtp_protection_profiles function */ MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, " "illegal DTLS-SRTP protection profile %d", ssl->conf->dtls_srtp_profile_list[protection_profiles_index] )); return MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; } } *p++ = mki_len & 0xFF; if (mki_len != 0) { memcpy(p, ssl->dtls_srtp_info.mki_value, mki_len); /* * Increment p to point to the current position. */ p += mki_len; MBEDTLS_SSL_DEBUG_BUF(3, "sending mki", ssl->dtls_srtp_info.mki_value, ssl->dtls_srtp_info.mki_len); } /* * total extension length: extension type (2 bytes) * + extension length (2 bytes) * + protection profile length (2 bytes) * + 2 * number of protection profiles * + srtp_mki vector length(1 byte) * + mki value */ *olen = p - buf; return 0; } #endif /* MBEDTLS_SSL_DTLS_SRTP */ int mbedtls_ssl_tls12_write_client_hello_exts(mbedtls_ssl_context *ssl, unsigned char *buf, const unsigned char *end, int uses_ec, size_t *out_len) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; unsigned char *p = buf; size_t ext_len = 0; (void) ssl; (void) end; (void) uses_ec; (void) ret; (void) ext_len; *out_len = 0; /* Note that TLS_EMPTY_RENEGOTIATION_INFO_SCSV is always added * even if MBEDTLS_SSL_RENEGOTIATION is not defined. */ #if defined(MBEDTLS_SSL_RENEGOTIATION) if ((ret = ssl_write_renegotiation_ext(ssl, p, end, &ext_len)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "ssl_write_renegotiation_ext", ret); return ret; } p += ext_len; #endif #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \ defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) if (uses_ec) { if ((ret = ssl_write_supported_point_formats_ext(ssl, p, end, &ext_len)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "ssl_write_supported_point_formats_ext", ret); return ret; } p += ext_len; } #endif #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) if ((ret = ssl_write_ecjpake_kkpp_ext(ssl, p, end, &ext_len)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "ssl_write_ecjpake_kkpp_ext", ret); return ret; } p += ext_len; #endif #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) if ((ret = ssl_write_cid_ext(ssl, p, end, &ext_len)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "ssl_write_cid_ext", ret); return ret; } p += ext_len; #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) if ((ret = ssl_write_max_fragment_length_ext(ssl, p, end, &ext_len)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "ssl_write_max_fragment_length_ext", ret); return ret; } p += ext_len; #endif #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) if ((ret = ssl_write_encrypt_then_mac_ext(ssl, p, end, &ext_len)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "ssl_write_encrypt_then_mac_ext", ret); return ret; } p += ext_len; #endif #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) if ((ret = ssl_write_extended_ms_ext(ssl, p, end, &ext_len)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "ssl_write_extended_ms_ext", ret); return ret; } p += ext_len; #endif #if defined(MBEDTLS_SSL_DTLS_SRTP) if ((ret = ssl_write_use_srtp_ext(ssl, p, end, &ext_len)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "ssl_write_use_srtp_ext", ret); return ret; } p += ext_len; #endif #if defined(MBEDTLS_SSL_SESSION_TICKETS) if ((ret = ssl_write_session_ticket_ext(ssl, p, end, &ext_len)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "ssl_write_session_ticket_ext", ret); return ret; } p += ext_len; #endif *out_len = p - buf; return 0; } MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_renegotiation_info(mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len) { #if defined(MBEDTLS_SSL_RENEGOTIATION) if (ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE) { /* Check verify-data in constant-time. The length OTOH is no secret */ if (len != 1 + ssl->verify_data_len * 2 || buf[0] != ssl->verify_data_len * 2 || mbedtls_ct_memcmp(buf + 1, ssl->own_verify_data, ssl->verify_data_len) != 0 || mbedtls_ct_memcmp(buf + 1 + ssl->verify_data_len, ssl->peer_verify_data, ssl->verify_data_len) != 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("non-matching renegotiation info")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } } else #endif /* MBEDTLS_SSL_RENEGOTIATION */ { if (len != 1 || buf[0] != 0x00) { MBEDTLS_SSL_DEBUG_MSG(1, ("non-zero length renegotiation info")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION; } return 0; } #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_max_fragment_length_ext(mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len) { /* * server should use the extension only if we did, * and if so the server's value should match ours (and len is always 1) */ if (ssl->conf->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE || len != 1 || buf[0] != ssl->conf->mfl_code) { MBEDTLS_SSL_DEBUG_MSG(1, ("non-matching max fragment length extension")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER); return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; } return 0; } #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */ #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_cid_ext(mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len) { size_t peer_cid_len; if ( /* CID extension only makes sense in DTLS */ ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM || /* The server must only send the CID extension if we have offered it. */ ssl->negotiate_cid == MBEDTLS_SSL_CID_DISABLED) { MBEDTLS_SSL_DEBUG_MSG(1, ("CID extension unexpected")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT); return MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION; } if (len == 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("CID extension invalid")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } peer_cid_len = *buf++; len--; if (peer_cid_len > MBEDTLS_SSL_CID_OUT_LEN_MAX) { MBEDTLS_SSL_DEBUG_MSG(1, ("CID extension invalid")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER); return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; } if (len != peer_cid_len) { MBEDTLS_SSL_DEBUG_MSG(1, ("CID extension invalid")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } ssl->handshake->cid_in_use = MBEDTLS_SSL_CID_ENABLED; ssl->handshake->peer_cid_len = (uint8_t) peer_cid_len; memcpy(ssl->handshake->peer_cid, buf, peer_cid_len); MBEDTLS_SSL_DEBUG_MSG(3, ("Use of CID extension negotiated")); MBEDTLS_SSL_DEBUG_BUF(3, "Server CID", buf, peer_cid_len); return 0; } #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_encrypt_then_mac_ext(mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len) { if (ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED || len != 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("non-matching encrypt-then-MAC extension")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT); return MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION; } ((void) buf); ssl->session_negotiate->encrypt_then_mac = MBEDTLS_SSL_ETM_ENABLED; return 0; } #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_extended_ms_ext(mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len) { if (ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED || len != 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("non-matching extended master secret extension")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT); return MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION; } ((void) buf); ssl->handshake->extended_ms = MBEDTLS_SSL_EXTENDED_MS_ENABLED; return 0; } #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_session_ticket_ext(mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len) { if (ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED || len != 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("non-matching session ticket extension")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT); return MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION; } ((void) buf); ssl->handshake->new_session_ticket = 1; return 0; } #endif /* MBEDTLS_SSL_SESSION_TICKETS */ #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \ defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_supported_point_formats_ext(mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len) { size_t list_size; const unsigned char *p; if (len == 0 || (size_t) (buf[0] + 1) != len) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server hello message")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } list_size = buf[0]; p = buf + 1; while (list_size > 0) { if (p[0] == MBEDTLS_ECP_PF_UNCOMPRESSED || p[0] == MBEDTLS_ECP_PF_COMPRESSED) { #if !defined(MBEDTLS_USE_PSA_CRYPTO) && \ (defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C)) ssl->handshake->ecdh_ctx.point_format = p[0]; #endif /* !MBEDTLS_USE_PSA_CRYPTO && ( MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ) */ #if !defined(MBEDTLS_USE_PSA_CRYPTO) && \ defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) mbedtls_ecjpake_set_point_format(&ssl->handshake->ecjpake_ctx, p[0]); #endif /* !MBEDTLS_USE_PSA_CRYPTO && MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ MBEDTLS_SSL_DEBUG_MSG(4, ("point format selected: %d", p[0])); return 0; } list_size--; p++; } MBEDTLS_SSL_DEBUG_MSG(1, ("no point format in common")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C || MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_ecjpake_kkpp(mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; if (ssl->handshake->ciphersuite_info->key_exchange != MBEDTLS_KEY_EXCHANGE_ECJPAKE) { MBEDTLS_SSL_DEBUG_MSG(3, ("skip ecjpake kkpp extension")); return 0; } /* If we got here, we no longer need our cached extension */ mbedtls_free(ssl->handshake->ecjpake_cache); ssl->handshake->ecjpake_cache = NULL; ssl->handshake->ecjpake_cache_len = 0; #if defined(MBEDTLS_USE_PSA_CRYPTO) if ((ret = mbedtls_psa_ecjpake_read_round( &ssl->handshake->psa_pake_ctx, buf, len, MBEDTLS_ECJPAKE_ROUND_ONE)) != 0) { psa_destroy_key(ssl->handshake->psa_pake_password); psa_pake_abort(&ssl->handshake->psa_pake_ctx); MBEDTLS_SSL_DEBUG_RET(1, "psa_pake_input round one", ret); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); return ret; } return 0; #else if ((ret = mbedtls_ecjpake_read_round_one(&ssl->handshake->ecjpake_ctx, buf, len)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecjpake_read_round_one", ret); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); return ret; } return 0; #endif /* MBEDTLS_USE_PSA_CRYPTO */ } #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ #if defined(MBEDTLS_SSL_ALPN) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_alpn_ext(mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len) { size_t list_len, name_len; const char **p; /* If we didn't send it, the server shouldn't send it */ if (ssl->conf->alpn_list == NULL) { MBEDTLS_SSL_DEBUG_MSG(1, ("non-matching ALPN extension")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT); return MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION; } /* * opaque ProtocolName<1..2^8-1>; * * struct { * ProtocolName protocol_name_list<2..2^16-1> * } ProtocolNameList; * * the "ProtocolNameList" MUST contain exactly one "ProtocolName" */ /* Min length is 2 (list_len) + 1 (name_len) + 1 (name) */ if (len < 4) { mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } list_len = (buf[0] << 8) | buf[1]; if (list_len != len - 2) { mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } name_len = buf[2]; if (name_len != list_len - 1) { mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } /* Check that the server chosen protocol was in our list and save it */ for (p = ssl->conf->alpn_list; *p != NULL; p++) { if (name_len == strlen(*p) && memcmp(buf + 3, *p, name_len) == 0) { ssl->alpn_chosen = *p; return 0; } } MBEDTLS_SSL_DEBUG_MSG(1, ("ALPN extension: no matching protocol")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } #endif /* MBEDTLS_SSL_ALPN */ #if defined(MBEDTLS_SSL_DTLS_SRTP) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_use_srtp_ext(mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len) { mbedtls_ssl_srtp_profile server_protection = MBEDTLS_TLS_SRTP_UNSET; size_t i, mki_len = 0; uint16_t server_protection_profile_value = 0; /* If use_srtp is not configured, just ignore the extension */ if ((ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM) || (ssl->conf->dtls_srtp_profile_list == NULL) || (ssl->conf->dtls_srtp_profile_list_len == 0)) { return 0; } /* RFC 5764 section 4.1.1 * uint8 SRTPProtectionProfile[2]; * * struct { * SRTPProtectionProfiles SRTPProtectionProfiles; * opaque srtp_mki<0..255>; * } UseSRTPData; * SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>; * */ if (ssl->conf->dtls_srtp_mki_support == MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED) { mki_len = ssl->dtls_srtp_info.mki_len; } /* * Length is 5 + optional mki_value : one protection profile length (2 bytes) * + protection profile (2 bytes) * + mki_len(1 byte) * and optional srtp_mki */ if ((len < 5) || (len != (buf[4] + 5u))) { return MBEDTLS_ERR_SSL_DECODE_ERROR; } /* * get the server protection profile */ /* * protection profile length must be 0x0002 as we must have only * one protection profile in server Hello */ if ((buf[0] != 0) || (buf[1] != 2)) { return MBEDTLS_ERR_SSL_DECODE_ERROR; } server_protection_profile_value = (buf[2] << 8) | buf[3]; server_protection = mbedtls_ssl_check_srtp_profile_value( server_protection_profile_value); if (server_protection != MBEDTLS_TLS_SRTP_UNSET) { MBEDTLS_SSL_DEBUG_MSG(3, ("found srtp profile: %s", mbedtls_ssl_get_srtp_profile_as_string( server_protection))); } ssl->dtls_srtp_info.chosen_dtls_srtp_profile = MBEDTLS_TLS_SRTP_UNSET; /* * Check we have the server profile in our list */ for (i = 0; i < ssl->conf->dtls_srtp_profile_list_len; i++) { if (server_protection == ssl->conf->dtls_srtp_profile_list[i]) { ssl->dtls_srtp_info.chosen_dtls_srtp_profile = ssl->conf->dtls_srtp_profile_list[i]; MBEDTLS_SSL_DEBUG_MSG(3, ("selected srtp profile: %s", mbedtls_ssl_get_srtp_profile_as_string( server_protection))); break; } } /* If no match was found : server problem, it shall never answer with incompatible profile */ if (ssl->dtls_srtp_info.chosen_dtls_srtp_profile == MBEDTLS_TLS_SRTP_UNSET) { mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } /* If server does not use mki in its reply, make sure the client won't keep * one as negotiated */ if (len == 5) { ssl->dtls_srtp_info.mki_len = 0; } /* * RFC5764: * If the client detects a nonzero-length MKI in the server's response * that is different than the one the client offered, then the client * MUST abort the handshake and SHOULD send an invalid_parameter alert. */ if (len > 5 && (buf[4] != mki_len || (memcmp(ssl->dtls_srtp_info.mki_value, &buf[5], mki_len)))) { mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER); return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; } #if defined(MBEDTLS_DEBUG_C) if (len > 5) { MBEDTLS_SSL_DEBUG_BUF(3, "received mki", ssl->dtls_srtp_info.mki_value, ssl->dtls_srtp_info.mki_len); } #endif return 0; } #endif /* MBEDTLS_SSL_DTLS_SRTP */ /* * Parse HelloVerifyRequest. Only called after verifying the HS type. */ #if defined(MBEDTLS_SSL_PROTO_DTLS) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_hello_verify_request(mbedtls_ssl_context *ssl) { const unsigned char *p = ssl->in_msg + mbedtls_ssl_hs_hdr_len(ssl); uint16_t dtls_legacy_version; #if !defined(MBEDTLS_SSL_PROTO_TLS1_3) uint8_t cookie_len; #else uint16_t cookie_len; #endif MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse hello verify request")); /* Check that there is enough room for: * - 2 bytes of version * - 1 byte of cookie_len */ if (mbedtls_ssl_hs_hdr_len(ssl) + 3 > ssl->in_msglen) { MBEDTLS_SSL_DEBUG_MSG(1, ("incoming HelloVerifyRequest message is too short")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } /* * struct { * ProtocolVersion server_version; * opaque cookie<0..2^8-1>; * } HelloVerifyRequest; */ MBEDTLS_SSL_DEBUG_BUF(3, "server version", p, 2); dtls_legacy_version = MBEDTLS_GET_UINT16_BE(p, 0); p += 2; /* * Since the RFC is not clear on this point, accept DTLS 1.0 (0xfeff) * The DTLS 1.3 (current draft) renames ProtocolVersion server_version to * legacy_version and locks the value of legacy_version to 0xfefd (DTLS 1.2) */ if (dtls_legacy_version != 0xfefd && dtls_legacy_version != 0xfeff) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server version")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION); return MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION; } cookie_len = *p++; if ((ssl->in_msg + ssl->in_msglen) - p < cookie_len) { MBEDTLS_SSL_DEBUG_MSG(1, ("cookie length does not match incoming message size")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } MBEDTLS_SSL_DEBUG_BUF(3, "cookie", p, cookie_len); mbedtls_free(ssl->handshake->cookie); ssl->handshake->cookie = mbedtls_calloc(1, cookie_len); if (ssl->handshake->cookie == NULL) { MBEDTLS_SSL_DEBUG_MSG(1, ("alloc failed (%d bytes)", cookie_len)); return MBEDTLS_ERR_SSL_ALLOC_FAILED; } memcpy(ssl->handshake->cookie, p, cookie_len); ssl->handshake->cookie_len = cookie_len; /* Start over at ClientHello */ ssl->state = MBEDTLS_SSL_CLIENT_HELLO; mbedtls_ssl_reset_checksum(ssl); mbedtls_ssl_recv_flight_completed(ssl); MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse hello verify request")); return 0; } #endif /* MBEDTLS_SSL_PROTO_DTLS */ MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_server_hello(mbedtls_ssl_context *ssl) { int ret, i; size_t n; size_t ext_len; unsigned char *buf, *ext; unsigned char comp; #if defined(MBEDTLS_SSL_RENEGOTIATION) int renegotiation_info_seen = 0; #endif int handshake_failure = 0; const mbedtls_ssl_ciphersuite_t *suite_info; MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse server hello")); if ((ret = mbedtls_ssl_read_record(ssl, 1)) != 0) { /* No alert on a read error. */ MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_read_record", ret); return ret; } buf = ssl->in_msg; if (ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE) { #if defined(MBEDTLS_SSL_RENEGOTIATION) if (ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS) { ssl->renego_records_seen++; if (ssl->conf->renego_max_records >= 0 && ssl->renego_records_seen > ssl->conf->renego_max_records) { MBEDTLS_SSL_DEBUG_MSG(1, ("renegotiation requested, but not honored by server")); return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; } MBEDTLS_SSL_DEBUG_MSG(1, ("non-handshake message during renegotiation")); ssl->keep_current_message = 1; return MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO; } #endif /* MBEDTLS_SSL_RENEGOTIATION */ MBEDTLS_SSL_DEBUG_MSG(1, ("bad server hello message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE); return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; } #if defined(MBEDTLS_SSL_PROTO_DTLS) if (ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM) { if (buf[0] == MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST) { MBEDTLS_SSL_DEBUG_MSG(2, ("received hello verify request")); MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse server hello")); return ssl_parse_hello_verify_request(ssl); } else { /* We made it through the verification process */ mbedtls_free(ssl->handshake->cookie); ssl->handshake->cookie = NULL; ssl->handshake->cookie_len = 0; } } #endif /* MBEDTLS_SSL_PROTO_DTLS */ if (ssl->in_hslen < 38 + mbedtls_ssl_hs_hdr_len(ssl) || buf[0] != MBEDTLS_SSL_HS_SERVER_HELLO) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server hello message")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } /* * 0 . 1 server_version * 2 . 33 random (maybe including 4 bytes of Unix time) * 34 . 34 session_id length = n * 35 . 34+n session_id * 35+n . 36+n cipher_suite * 37+n . 37+n compression_method * * 38+n . 39+n extensions length (optional) * 40+n . .. extensions */ buf += mbedtls_ssl_hs_hdr_len(ssl); MBEDTLS_SSL_DEBUG_BUF(3, "server hello, version", buf, 2); ssl->tls_version = mbedtls_ssl_read_version(buf, ssl->conf->transport); ssl->session_negotiate->tls_version = ssl->tls_version; if (ssl->tls_version < ssl->conf->min_tls_version || ssl->tls_version > ssl->conf->max_tls_version) { MBEDTLS_SSL_DEBUG_MSG(1, ( "server version out of bounds - min: [0x%x], server: [0x%x], max: [0x%x]", (unsigned) ssl->conf->min_tls_version, (unsigned) ssl->tls_version, (unsigned) ssl->conf->max_tls_version)); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION); return MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION; } MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, current time: %lu", ((unsigned long) buf[2] << 24) | ((unsigned long) buf[3] << 16) | ((unsigned long) buf[4] << 8) | ((unsigned long) buf[5]))); memcpy(ssl->handshake->randbytes + 32, buf + 2, 32); n = buf[34]; MBEDTLS_SSL_DEBUG_BUF(3, "server hello, random bytes", buf + 2, 32); if (n > 32) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server hello message")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } if (ssl->in_hslen > mbedtls_ssl_hs_hdr_len(ssl) + 39 + n) { ext_len = ((buf[38 + n] << 8) | (buf[39 + n])); if ((ext_len > 0 && ext_len < 4) || ssl->in_hslen != mbedtls_ssl_hs_hdr_len(ssl) + 40 + n + ext_len) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server hello message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } } else if (ssl->in_hslen == mbedtls_ssl_hs_hdr_len(ssl) + 38 + n) { ext_len = 0; } else { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server hello message")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } /* ciphersuite (used later) */ i = (buf[35 + n] << 8) | buf[36 + n]; /* * Read and check compression */ comp = buf[37 + n]; if (comp != MBEDTLS_SSL_COMPRESS_NULL) { MBEDTLS_SSL_DEBUG_MSG(1, ("server hello, bad compression: %d", comp)); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER); return MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; } /* * Initialize update checksum functions */ ssl->handshake->ciphersuite_info = mbedtls_ssl_ciphersuite_from_id(i); if (ssl->handshake->ciphersuite_info == NULL) { MBEDTLS_SSL_DEBUG_MSG(1, ("ciphersuite info for %04x not found", (unsigned int) i)); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR); return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; } mbedtls_ssl_optimize_checksum(ssl, ssl->handshake->ciphersuite_info); MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, session id len.: %" MBEDTLS_PRINTF_SIZET, n)); MBEDTLS_SSL_DEBUG_BUF(3, "server hello, session id", buf + 35, n); /* * Check if the session can be resumed */ if (ssl->handshake->resume == 0 || n == 0 || #if defined(MBEDTLS_SSL_RENEGOTIATION) ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE || #endif ssl->session_negotiate->ciphersuite != i || ssl->session_negotiate->id_len != n || memcmp(ssl->session_negotiate->id, buf + 35, n) != 0) { ssl->state++; ssl->handshake->resume = 0; #if defined(MBEDTLS_HAVE_TIME) ssl->session_negotiate->start = mbedtls_time(NULL); #endif ssl->session_negotiate->ciphersuite = i; ssl->session_negotiate->id_len = n; memcpy(ssl->session_negotiate->id, buf + 35, n); } else { ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC; } MBEDTLS_SSL_DEBUG_MSG(3, ("%s session has been resumed", ssl->handshake->resume ? "a" : "no")); MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, chosen ciphersuite: %04x", (unsigned) i)); MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, compress alg.: %d", buf[37 + n])); /* * Perform cipher suite validation in same way as in ssl_write_client_hello. */ i = 0; while (1) { if (ssl->conf->ciphersuite_list[i] == 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server hello message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER); return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; } if (ssl->conf->ciphersuite_list[i++] == ssl->session_negotiate->ciphersuite) { break; } } suite_info = mbedtls_ssl_ciphersuite_from_id( ssl->session_negotiate->ciphersuite); if (mbedtls_ssl_validate_ciphersuite(ssl, suite_info, ssl->tls_version, ssl->tls_version) != 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server hello message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, chosen ciphersuite: %s", suite_info->name)); #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (suite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA && ssl->tls_version == MBEDTLS_SSL_VERSION_TLS1_2) { ssl->handshake->ecrs_enabled = 1; } #endif if (comp != MBEDTLS_SSL_COMPRESS_NULL) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server hello message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER); return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; } ext = buf + 40 + n; MBEDTLS_SSL_DEBUG_MSG(2, ("server hello, total extension length: %" MBEDTLS_PRINTF_SIZET, ext_len)); while (ext_len) { unsigned int ext_id = ((ext[0] << 8) | (ext[1])); unsigned int ext_size = ((ext[2] << 8) | (ext[3])); if (ext_size + 4 > ext_len) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server hello message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } switch (ext_id) { case MBEDTLS_TLS_EXT_RENEGOTIATION_INFO: MBEDTLS_SSL_DEBUG_MSG(3, ("found renegotiation extension")); #if defined(MBEDTLS_SSL_RENEGOTIATION) renegotiation_info_seen = 1; #endif if ((ret = ssl_parse_renegotiation_info(ssl, ext + 4, ext_size)) != 0) { return ret; } break; #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) case MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH: MBEDTLS_SSL_DEBUG_MSG(3, ("found max_fragment_length extension")); if ((ret = ssl_parse_max_fragment_length_ext(ssl, ext + 4, ext_size)) != 0) { return ret; } break; #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */ #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) case MBEDTLS_TLS_EXT_CID: MBEDTLS_SSL_DEBUG_MSG(3, ("found CID extension")); if ((ret = ssl_parse_cid_ext(ssl, ext + 4, ext_size)) != 0) { return ret; } break; #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) case MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC: MBEDTLS_SSL_DEBUG_MSG(3, ("found encrypt_then_mac extension")); if ((ret = ssl_parse_encrypt_then_mac_ext(ssl, ext + 4, ext_size)) != 0) { return ret; } break; #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */ #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) case MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET: MBEDTLS_SSL_DEBUG_MSG(3, ("found extended_master_secret extension")); if ((ret = ssl_parse_extended_ms_ext(ssl, ext + 4, ext_size)) != 0) { return ret; } break; #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) case MBEDTLS_TLS_EXT_SESSION_TICKET: MBEDTLS_SSL_DEBUG_MSG(3, ("found session_ticket extension")); if ((ret = ssl_parse_session_ticket_ext(ssl, ext + 4, ext_size)) != 0) { return ret; } break; #endif /* MBEDTLS_SSL_SESSION_TICKETS */ #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \ defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) case MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS: MBEDTLS_SSL_DEBUG_MSG(3, ("found supported_point_formats extension")); if ((ret = ssl_parse_supported_point_formats_ext(ssl, ext + 4, ext_size)) != 0) { return ret; } break; #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C || MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) case MBEDTLS_TLS_EXT_ECJPAKE_KKPP: MBEDTLS_SSL_DEBUG_MSG(3, ("found ecjpake_kkpp extension")); if ((ret = ssl_parse_ecjpake_kkpp(ssl, ext + 4, ext_size)) != 0) { return ret; } break; #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ #if defined(MBEDTLS_SSL_ALPN) case MBEDTLS_TLS_EXT_ALPN: MBEDTLS_SSL_DEBUG_MSG(3, ("found alpn extension")); if ((ret = ssl_parse_alpn_ext(ssl, ext + 4, ext_size)) != 0) { return ret; } break; #endif /* MBEDTLS_SSL_ALPN */ #if defined(MBEDTLS_SSL_DTLS_SRTP) case MBEDTLS_TLS_EXT_USE_SRTP: MBEDTLS_SSL_DEBUG_MSG(3, ("found use_srtp extension")); if ((ret = ssl_parse_use_srtp_ext(ssl, ext + 4, ext_size)) != 0) { return ret; } break; #endif /* MBEDTLS_SSL_DTLS_SRTP */ default: MBEDTLS_SSL_DEBUG_MSG(3, ("unknown extension found: %u (ignoring)", ext_id)); } ext_len -= 4 + ext_size; ext += 4 + ext_size; if (ext_len > 0 && ext_len < 4) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server hello message")); return MBEDTLS_ERR_SSL_DECODE_ERROR; } } /* * mbedtls_ssl_derive_keys() has to be called after the parsing of the * extensions. It sets the transform data for the resumed session which in * case of DTLS includes the server CID extracted from the CID extension. */ if (ssl->handshake->resume) { if ((ret = mbedtls_ssl_derive_keys(ssl)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_derive_keys", ret); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR); return ret; } } /* * Renegotiation security checks */ if (ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION && ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE) { MBEDTLS_SSL_DEBUG_MSG(1, ("legacy renegotiation, breaking off handshake")); handshake_failure = 1; } #if defined(MBEDTLS_SSL_RENEGOTIATION) else if (ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS && ssl->secure_renegotiation == MBEDTLS_SSL_SECURE_RENEGOTIATION && renegotiation_info_seen == 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("renegotiation_info extension missing (secure)")); handshake_failure = 1; } else if (ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS && ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION && ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION) { MBEDTLS_SSL_DEBUG_MSG(1, ("legacy renegotiation not allowed")); handshake_failure = 1; } else if (ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS && ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION && renegotiation_info_seen == 1) { MBEDTLS_SSL_DEBUG_MSG(1, ("renegotiation_info extension present (legacy)")); handshake_failure = 1; } #endif /* MBEDTLS_SSL_RENEGOTIATION */ if (handshake_failure == 1) { mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse server hello")); return 0; } #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_server_dh_params(mbedtls_ssl_context *ssl, unsigned char **p, unsigned char *end) { int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; size_t dhm_actual_bitlen; /* * Ephemeral DH parameters: * * struct { * opaque dh_p<1..2^16-1>; * opaque dh_g<1..2^16-1>; * opaque dh_Ys<1..2^16-1>; * } ServerDHParams; */ if ((ret = mbedtls_dhm_read_params(&ssl->handshake->dhm_ctx, p, end)) != 0) { MBEDTLS_SSL_DEBUG_RET(2, ("mbedtls_dhm_read_params"), ret); return ret; } dhm_actual_bitlen = mbedtls_dhm_get_bitlen(&ssl->handshake->dhm_ctx); if (dhm_actual_bitlen < ssl->conf->dhm_min_bitlen) { MBEDTLS_SSL_DEBUG_MSG(1, ("DHM prime too short: %" MBEDTLS_PRINTF_SIZET " < %u", dhm_actual_bitlen, ssl->conf->dhm_min_bitlen)); return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } MBEDTLS_SSL_DEBUG_MPI(3, "DHM: P ", &ssl->handshake->dhm_ctx.P); MBEDTLS_SSL_DEBUG_MPI(3, "DHM: G ", &ssl->handshake->dhm_ctx.G); MBEDTLS_SSL_DEBUG_MPI(3, "DHM: GY", &ssl->handshake->dhm_ctx.GY); return ret; } #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED || MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */ #if defined(MBEDTLS_USE_PSA_CRYPTO) #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_server_ecdh_params(mbedtls_ssl_context *ssl, unsigned char **p, unsigned char *end) { uint16_t tls_id; uint8_t ecpoint_len; mbedtls_ssl_handshake_params *handshake = ssl->handshake; psa_ecc_family_t ec_psa_family = 0; size_t ec_bits = 0; /* * struct { * ECParameters curve_params; * ECPoint public; * } ServerECDHParams; * * 1 curve_type (must be "named_curve") * 2..3 NamedCurve * 4 ECPoint.len * 5+ ECPoint contents */ if (end - *p < 4) { return MBEDTLS_ERR_SSL_DECODE_ERROR; } /* First byte is curve_type; only named_curve is handled */ if (*(*p)++ != MBEDTLS_ECP_TLS_NAMED_CURVE) { return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } /* Next two bytes are the namedcurve value */ tls_id = *(*p)++; tls_id <<= 8; tls_id |= *(*p)++; /* Check it's a curve we offered */ if (mbedtls_ssl_check_curve_tls_id(ssl, tls_id) != 0) { MBEDTLS_SSL_DEBUG_MSG(2, ("bad server key exchange message (ECDHE curve): %u", (unsigned) tls_id)); return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } /* Convert EC's TLS ID to PSA key type. */ if (mbedtls_ssl_get_psa_curve_info_from_tls_id(tls_id, &ec_psa_family, &ec_bits) == PSA_ERROR_NOT_SUPPORTED) { return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } handshake->ecdh_psa_type = PSA_KEY_TYPE_ECC_KEY_PAIR(ec_psa_family); handshake->ecdh_bits = ec_bits; /* Keep a copy of the peer's public key */ ecpoint_len = *(*p)++; if ((size_t) (end - *p) < ecpoint_len) { return MBEDTLS_ERR_SSL_DECODE_ERROR; } if (ecpoint_len > sizeof(handshake->ecdh_psa_peerkey)) { return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } memcpy(handshake->ecdh_psa_peerkey, *p, ecpoint_len); handshake->ecdh_psa_peerkey_len = ecpoint_len; *p += ecpoint_len; return 0; } #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */ #else #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_check_server_ecdh_params(const mbedtls_ssl_context *ssl) { uint16_t tls_id; mbedtls_ecp_group_id grp_id; #if defined(MBEDTLS_ECDH_LEGACY_CONTEXT) grp_id = ssl->handshake->ecdh_ctx.grp.id; #else grp_id = ssl->handshake->ecdh_ctx.grp_id; #endif tls_id = mbedtls_ssl_get_tls_id_from_ecp_group_id(grp_id); if (tls_id == 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); return MBEDTLS_ERR_SSL_INTERNAL_ERROR; } MBEDTLS_SSL_DEBUG_MSG(2, ("ECDH curve: %s", mbedtls_ssl_get_curve_name_from_tls_id(tls_id))); if (mbedtls_ssl_check_curve(ssl, grp_id) != 0) { return -1; } MBEDTLS_SSL_DEBUG_ECDH(3, &ssl->handshake->ecdh_ctx, MBEDTLS_DEBUG_ECDH_QP); return 0; } #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_server_ecdh_params(mbedtls_ssl_context *ssl, unsigned char **p, unsigned char *end) { int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; /* * Ephemeral ECDH parameters: * * struct { * ECParameters curve_params; * ECPoint public; * } ServerECDHParams; */ if ((ret = mbedtls_ecdh_read_params(&ssl->handshake->ecdh_ctx, (const unsigned char **) p, end)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, ("mbedtls_ecdh_read_params"), ret); #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (ret == MBEDTLS_ERR_ECP_IN_PROGRESS) { ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS; } #endif return ret; } if (ssl_check_server_ecdh_params(ssl) != 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server key exchange message (ECDHE curve)")); return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } return ret; } #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED || \ MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED || \ MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */ #endif /* !MBEDTLS_USE_PSA_CRYPTO */ #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_server_psk_hint(mbedtls_ssl_context *ssl, unsigned char **p, unsigned char *end) { int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; uint16_t len; ((void) ssl); /* * PSK parameters: * * opaque psk_identity_hint<0..2^16-1>; */ if (end - (*p) < 2) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server key exchange message (psk_identity_hint length)")); return MBEDTLS_ERR_SSL_DECODE_ERROR; } len = (*p)[0] << 8 | (*p)[1]; *p += 2; if (end - (*p) < len) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server key exchange message (psk_identity_hint length)")); return MBEDTLS_ERR_SSL_DECODE_ERROR; } /* * Note: we currently ignore the PSK identity hint, as we only allow one * PSK to be provisioned on the client. This could be changed later if * someone needs that feature. */ *p += len; ret = 0; return ret; } #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) /* * Generate a pre-master secret and encrypt it with the server's RSA key */ MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_write_encrypted_pms(mbedtls_ssl_context *ssl, size_t offset, size_t *olen, size_t pms_offset) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t len_bytes = 2; unsigned char *p = ssl->handshake->premaster + pms_offset; mbedtls_pk_context *peer_pk; if (offset + len_bytes > MBEDTLS_SSL_OUT_CONTENT_LEN) { MBEDTLS_SSL_DEBUG_MSG(1, ("buffer too small for encrypted pms")); return MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL; } /* * Generate (part of) the pre-master as * struct { * ProtocolVersion client_version; * opaque random[46]; * } PreMasterSecret; */ mbedtls_ssl_write_version(p, ssl->conf->transport, MBEDTLS_SSL_VERSION_TLS1_2); if ((ret = ssl->conf->f_rng(ssl->conf->p_rng, p + 2, 46)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "f_rng", ret); return ret; } ssl->handshake->pmslen = 48; #if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) peer_pk = &ssl->handshake->peer_pubkey; #else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ if (ssl->session_negotiate->peer_cert == NULL) { /* Should never happen */ MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); return MBEDTLS_ERR_SSL_INTERNAL_ERROR; } peer_pk = &ssl->session_negotiate->peer_cert->pk; #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ /* * Now write it out, encrypted */ if (!mbedtls_pk_can_do(peer_pk, MBEDTLS_PK_RSA)) { MBEDTLS_SSL_DEBUG_MSG(1, ("certificate key type mismatch")); return MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH; } if ((ret = mbedtls_pk_encrypt(peer_pk, p, ssl->handshake->pmslen, ssl->out_msg + offset + len_bytes, olen, MBEDTLS_SSL_OUT_CONTENT_LEN - offset - len_bytes, ssl->conf->f_rng, ssl->conf->p_rng)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_rsa_pkcs1_encrypt", ret); return ret; } if (len_bytes == 2) { MBEDTLS_PUT_UINT16_BE(*olen, ssl->out_msg, offset); *olen += 2; } #if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) /* We don't need the peer's public key anymore. Free it. */ mbedtls_pk_free(peer_pk); #endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ return 0; } #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED || MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_get_ecdh_params_from_cert(mbedtls_ssl_context *ssl) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; const mbedtls_ecp_keypair *peer_key; mbedtls_pk_context *peer_pk; #if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) peer_pk = &ssl->handshake->peer_pubkey; #else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ if (ssl->session_negotiate->peer_cert == NULL) { /* Should never happen */ MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); return MBEDTLS_ERR_SSL_INTERNAL_ERROR; } peer_pk = &ssl->session_negotiate->peer_cert->pk; #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ /* This is a public key, so it can't be opaque, so can_do() is a good * enough check to ensure pk_ec() is safe to use below. */ if (!mbedtls_pk_can_do(peer_pk, MBEDTLS_PK_ECKEY)) { MBEDTLS_SSL_DEBUG_MSG(1, ("server key not ECDH capable")); return MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH; } peer_key = mbedtls_pk_ec(*peer_pk); #if defined(MBEDTLS_USE_PSA_CRYPTO) size_t olen = 0; uint16_t tls_id = 0; psa_ecc_family_t ecc_family; if (mbedtls_ssl_check_curve(ssl, peer_key->grp.id) != 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server certificate (ECDH curve)")); return MBEDTLS_ERR_SSL_BAD_CERTIFICATE; } tls_id = mbedtls_ssl_get_tls_id_from_ecp_group_id(peer_key->grp.id); if (tls_id == 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("ECC group %u not suported", peer_key->grp.id)); return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; } /* If the above conversion to TLS ID was fine, then also this one will be, so there is no need to check the return value here */ mbedtls_ssl_get_psa_curve_info_from_tls_id(tls_id, &ecc_family, &ssl->handshake->ecdh_bits); ssl->handshake->ecdh_psa_type = PSA_KEY_TYPE_ECC_KEY_PAIR(ecc_family); /* Store peer's public key in psa format. */ ret = mbedtls_ecp_point_write_binary(&peer_key->grp, &peer_key->Q, MBEDTLS_ECP_PF_UNCOMPRESSED, &olen, ssl->handshake->ecdh_psa_peerkey, MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH); if (ret != 0) { MBEDTLS_SSL_DEBUG_RET(1, ("mbedtls_ecp_point_write_binary"), ret); return ret; } ssl->handshake->ecdh_psa_peerkey_len = olen; #else if ((ret = mbedtls_ecdh_get_params(&ssl->handshake->ecdh_ctx, peer_key, MBEDTLS_ECDH_THEIRS)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, ("mbedtls_ecdh_get_params"), ret); return ret; } if (ssl_check_server_ecdh_params(ssl) != 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server certificate (ECDH curve)")); return MBEDTLS_ERR_SSL_BAD_CERTIFICATE; } #endif #if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) /* We don't need the peer's public key anymore. Free it, * so that more RAM is available for upcoming expensive * operations like ECDHE. */ mbedtls_pk_free(peer_pk); #endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ return ret; } #endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_server_key_exchange(mbedtls_ssl_context *ssl) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info; unsigned char *p = NULL, *end = NULL; MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse server key exchange")); #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA) { MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip parse server key exchange")); ssl->state++; return 0; } ((void) p); ((void) end); #endif #if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_RSA || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA) { if ((ret = ssl_get_ecdh_params_from_cert(ssl)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "ssl_get_ecdh_params_from_cert", ret); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); return ret; } MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip parse server key exchange")); ssl->state++; return 0; } ((void) p); ((void) end); #endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (ssl->handshake->ecrs_enabled && ssl->handshake->ecrs_state == ssl_ecrs_ske_start_processing) { goto start_processing; } #endif if ((ret = mbedtls_ssl_read_record(ssl, 1)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_read_record", ret); return ret; } if (ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server key exchange message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE); return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; } /* * ServerKeyExchange may be skipped with PSK and RSA-PSK when the server * doesn't use a psk_identity_hint */ if (ssl->in_msg[0] != MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE) { if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK) { /* Current message is probably either * CertificateRequest or ServerHelloDone */ ssl->keep_current_message = 1; goto exit; } MBEDTLS_SSL_DEBUG_MSG(1, ("server key exchange message must not be skipped")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE); return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; } #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (ssl->handshake->ecrs_enabled) { ssl->handshake->ecrs_state = ssl_ecrs_ske_start_processing; } start_processing: #endif p = ssl->in_msg + mbedtls_ssl_hs_hdr_len(ssl); end = ssl->in_msg + ssl->in_hslen; MBEDTLS_SSL_DEBUG_BUF(3, "server key exchange", p, end - p); #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK) { if (ssl_parse_server_psk_hint(ssl, &p, end) != 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server key exchange message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } } /* FALLTHROUGH */ #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK) { ; /* nothing more to do */ } else #endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED || MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_RSA || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK) { if (ssl_parse_server_dh_params(ssl, &p, end) != 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server key exchange message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER); return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; } } else #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED || MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_RSA || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA) { if (ssl_parse_server_ecdh_params(ssl, &p, end) != 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server key exchange message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER); return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; } } else #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE) { #if defined(MBEDTLS_USE_PSA_CRYPTO) /* * The first 3 bytes are: * [0] MBEDTLS_ECP_TLS_NAMED_CURVE * [1, 2] elliptic curve's TLS ID * * However since we only support secp256r1 for now, we check only * that TLS ID here */ uint16_t read_tls_id = MBEDTLS_GET_UINT16_BE(p, 1); uint16_t exp_tls_id = mbedtls_ssl_get_tls_id_from_ecp_group_id( MBEDTLS_ECP_DP_SECP256R1); if (exp_tls_id == 0) { return MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; } if ((*p != MBEDTLS_ECP_TLS_NAMED_CURVE) || (read_tls_id != exp_tls_id)) { return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; } p += 3; if ((ret = mbedtls_psa_ecjpake_read_round( &ssl->handshake->psa_pake_ctx, p, end - p, MBEDTLS_ECJPAKE_ROUND_TWO)) != 0) { psa_destroy_key(ssl->handshake->psa_pake_password); psa_pake_abort(&ssl->handshake->psa_pake_ctx); MBEDTLS_SSL_DEBUG_RET(1, "psa_pake_input round two", ret); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } #else ret = mbedtls_ecjpake_read_round_two(&ssl->handshake->ecjpake_ctx, p, end - p); if (ret != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecjpake_read_round_two", ret); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; } #endif /* MBEDTLS_USE_PSA_CRYPTO */ } else #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ { MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); return MBEDTLS_ERR_SSL_INTERNAL_ERROR; } #if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) if (mbedtls_ssl_ciphersuite_uses_server_signature(ciphersuite_info)) { size_t sig_len, hashlen; unsigned char hash[MBEDTLS_HASH_MAX_SIZE]; mbedtls_md_type_t md_alg = MBEDTLS_MD_NONE; mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE; unsigned char *params = ssl->in_msg + mbedtls_ssl_hs_hdr_len(ssl); size_t params_len = p - params; void *rs_ctx = NULL; uint16_t sig_alg; mbedtls_pk_context *peer_pk; #if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) peer_pk = &ssl->handshake->peer_pubkey; #else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ if (ssl->session_negotiate->peer_cert == NULL) { /* Should never happen */ MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); return MBEDTLS_ERR_SSL_INTERNAL_ERROR; } peer_pk = &ssl->session_negotiate->peer_cert->pk; #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ /* * Handle the digitally-signed structure */ MBEDTLS_SSL_CHK_BUF_READ_PTR(p, end, 2); sig_alg = MBEDTLS_GET_UINT16_BE(p, 0); if (mbedtls_ssl_get_pk_type_and_md_alg_from_sig_alg( sig_alg, &pk_alg, &md_alg) != 0 && !mbedtls_ssl_sig_alg_is_offered(ssl, sig_alg) && !mbedtls_ssl_sig_alg_is_supported(ssl, sig_alg)) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server key exchange message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER); return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; } p += 2; if (!mbedtls_pk_can_do(peer_pk, pk_alg)) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server key exchange message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER); return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; } /* * Read signature */ if (p > end - 2) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server key exchange message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } sig_len = (p[0] << 8) | p[1]; p += 2; if (p != end - sig_len) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server key exchange message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } MBEDTLS_SSL_DEBUG_BUF(3, "signature", p, sig_len); /* * Compute the hash that has been signed */ if (md_alg != MBEDTLS_MD_NONE) { ret = mbedtls_ssl_get_key_exchange_md_tls1_2(ssl, hash, &hashlen, params, params_len, md_alg); if (ret != 0) { return ret; } } else { MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); return MBEDTLS_ERR_SSL_INTERNAL_ERROR; } MBEDTLS_SSL_DEBUG_BUF(3, "parameters hash", hash, hashlen); /* * Verify signature */ if (!mbedtls_pk_can_do(peer_pk, pk_alg)) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server key exchange message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); return MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH; } #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (ssl->handshake->ecrs_enabled) { rs_ctx = &ssl->handshake->ecrs_ctx.pk; } #endif #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT) if (pk_alg == MBEDTLS_PK_RSASSA_PSS) { mbedtls_pk_rsassa_pss_options rsassa_pss_options; rsassa_pss_options.mgf1_hash_id = md_alg; rsassa_pss_options.expected_salt_len = mbedtls_hash_info_get_size(md_alg); if (rsassa_pss_options.expected_salt_len == 0) { return MBEDTLS_ERR_SSL_INTERNAL_ERROR; } ret = mbedtls_pk_verify_ext(pk_alg, &rsassa_pss_options, peer_pk, md_alg, hash, hashlen, p, sig_len); } else #endif /* MBEDTLS_X509_RSASSA_PSS_SUPPORT */ ret = mbedtls_pk_verify_restartable(peer_pk, md_alg, hash, hashlen, p, sig_len, rs_ctx); if (ret != 0) { int send_alert_msg = 1; #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) send_alert_msg = (ret != MBEDTLS_ERR_ECP_IN_PROGRESS); #endif if (send_alert_msg) { mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECRYPT_ERROR); } MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_pk_verify", ret); #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (ret == MBEDTLS_ERR_ECP_IN_PROGRESS) { ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS; } #endif return ret; } #if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) /* We don't need the peer's public key anymore. Free it, * so that more RAM is available for upcoming expensive * operations like ECDHE. */ mbedtls_pk_free(peer_pk); #endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ } #endif /* MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED */ exit: ssl->state++; MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse server key exchange")); return 0; } #if !defined(MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_certificate_request(mbedtls_ssl_context *ssl) { const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info; MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse certificate request")); if (!mbedtls_ssl_ciphersuite_cert_req_allowed(ciphersuite_info)) { MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip parse certificate request")); ssl->state++; return 0; } MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); return MBEDTLS_ERR_SSL_INTERNAL_ERROR; } #else /* MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */ MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_certificate_request(mbedtls_ssl_context *ssl) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; unsigned char *buf; size_t n = 0; size_t cert_type_len = 0, dn_len = 0; const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info; size_t sig_alg_len; #if defined(MBEDTLS_DEBUG_C) unsigned char *sig_alg; unsigned char *dn; #endif MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse certificate request")); if (!mbedtls_ssl_ciphersuite_cert_req_allowed(ciphersuite_info)) { MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip parse certificate request")); ssl->state++; return 0; } if ((ret = mbedtls_ssl_read_record(ssl, 1)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_read_record", ret); return ret; } if (ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad certificate request message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE); return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; } ssl->state++; ssl->handshake->client_auth = (ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE_REQUEST); MBEDTLS_SSL_DEBUG_MSG(3, ("got %s certificate request", ssl->handshake->client_auth ? "a" : "no")); if (ssl->handshake->client_auth == 0) { /* Current message is probably the ServerHelloDone */ ssl->keep_current_message = 1; goto exit; } /* * struct { * ClientCertificateType certificate_types<1..2^8-1>; * SignatureAndHashAlgorithm * supported_signature_algorithms<2^16-1>; -- TLS 1.2 only * DistinguishedName certificate_authorities<0..2^16-1>; * } CertificateRequest; * * Since we only support a single certificate on clients, let's just * ignore all the information that's supposed to help us pick a * certificate. * * We could check that our certificate matches the request, and bail out * if it doesn't, but it's simpler to just send the certificate anyway, * and give the server the opportunity to decide if it should terminate * the connection when it doesn't like our certificate. * * Same goes for the hash in TLS 1.2's signature_algorithms: at this * point we only have one hash available (see comments in * write_certificate_verify), so let's just use what we have. * * However, we still minimally parse the message to check it is at least * superficially sane. */ buf = ssl->in_msg; /* certificate_types */ if (ssl->in_hslen <= mbedtls_ssl_hs_hdr_len(ssl)) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad certificate request message")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } cert_type_len = buf[mbedtls_ssl_hs_hdr_len(ssl)]; n = cert_type_len; /* * In the subsequent code there are two paths that read from buf: * * the length of the signature algorithms field (if minor version of * SSL is 3), * * distinguished name length otherwise. * Both reach at most the index: * ...hdr_len + 2 + n, * therefore the buffer length at this point must be greater than that * regardless of the actual code path. */ if (ssl->in_hslen <= mbedtls_ssl_hs_hdr_len(ssl) + 2 + n) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad certificate request message")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } /* supported_signature_algorithms */ sig_alg_len = ((buf[mbedtls_ssl_hs_hdr_len(ssl) + 1 + n] << 8) | (buf[mbedtls_ssl_hs_hdr_len(ssl) + 2 + n])); /* * The furthest access in buf is in the loop few lines below: * sig_alg[i + 1], * where: * sig_alg = buf + ...hdr_len + 3 + n, * max(i) = sig_alg_len - 1. * Therefore the furthest access is: * buf[...hdr_len + 3 + n + sig_alg_len - 1 + 1], * which reduces to: * buf[...hdr_len + 3 + n + sig_alg_len], * which is one less than we need the buf to be. */ if (ssl->in_hslen <= mbedtls_ssl_hs_hdr_len(ssl) + 3 + n + sig_alg_len) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad certificate request message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } #if defined(MBEDTLS_DEBUG_C) sig_alg = buf + mbedtls_ssl_hs_hdr_len(ssl) + 3 + n; for (size_t i = 0; i < sig_alg_len; i += 2) { MBEDTLS_SSL_DEBUG_MSG(3, ("Supported Signature Algorithm found: %02x %02x", sig_alg[i], sig_alg[i + 1])); } #endif n += 2 + sig_alg_len; /* certificate_authorities */ dn_len = ((buf[mbedtls_ssl_hs_hdr_len(ssl) + 1 + n] << 8) | (buf[mbedtls_ssl_hs_hdr_len(ssl) + 2 + n])); n += dn_len; if (ssl->in_hslen != mbedtls_ssl_hs_hdr_len(ssl) + 3 + n) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad certificate request message")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } #if defined(MBEDTLS_DEBUG_C) dn = buf + mbedtls_ssl_hs_hdr_len(ssl) + 3 + n - dn_len; for (size_t i = 0, dni_len = 0; i < dn_len; i += 2 + dni_len) { unsigned char *p = dn + i + 2; mbedtls_x509_name name; size_t asn1_len; char s[MBEDTLS_X509_MAX_DN_NAME_SIZE]; memset(&name, 0, sizeof(name)); dni_len = MBEDTLS_GET_UINT16_BE(dn + i, 0); if (dni_len > dn_len - i - 2 || mbedtls_asn1_get_tag(&p, p + dni_len, &asn1_len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE) != 0 || mbedtls_x509_get_name(&p, p + asn1_len, &name) != 0) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad certificate request message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } MBEDTLS_SSL_DEBUG_MSG(3, ("DN hint: %.*s", mbedtls_x509_dn_gets(s, sizeof(s), &name), s)); mbedtls_asn1_free_named_data_list_shallow(name.next); } #endif exit: MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse certificate request")); return 0; } #endif /* MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */ MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_server_hello_done(mbedtls_ssl_context *ssl) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse server hello done")); if ((ret = mbedtls_ssl_read_record(ssl, 1)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_read_record", ret); return ret; } if (ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server hello done message")); return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; } if (ssl->in_hslen != mbedtls_ssl_hs_hdr_len(ssl) || ssl->in_msg[0] != MBEDTLS_SSL_HS_SERVER_HELLO_DONE) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad server hello done message")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } ssl->state++; #if defined(MBEDTLS_SSL_PROTO_DTLS) if (ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM) { mbedtls_ssl_recv_flight_completed(ssl); } #endif MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse server hello done")); return 0; } MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_write_client_key_exchange(mbedtls_ssl_context *ssl) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; size_t header_len; size_t content_len; const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info; MBEDTLS_SSL_DEBUG_MSG(2, ("=> write client key exchange")); #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_RSA) { /* * DHM key exchange -- send G^X mod P */ content_len = mbedtls_dhm_get_len(&ssl->handshake->dhm_ctx); MBEDTLS_PUT_UINT16_BE(content_len, ssl->out_msg, 4); header_len = 6; ret = mbedtls_dhm_make_public(&ssl->handshake->dhm_ctx, (int) mbedtls_dhm_get_len(&ssl->handshake->dhm_ctx), &ssl->out_msg[header_len], content_len, ssl->conf->f_rng, ssl->conf->p_rng); if (ret != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_dhm_make_public", ret); return ret; } MBEDTLS_SSL_DEBUG_MPI(3, "DHM: X ", &ssl->handshake->dhm_ctx.X); MBEDTLS_SSL_DEBUG_MPI(3, "DHM: GX", &ssl->handshake->dhm_ctx.GX); if ((ret = mbedtls_dhm_calc_secret(&ssl->handshake->dhm_ctx, ssl->handshake->premaster, MBEDTLS_PREMASTER_SIZE, &ssl->handshake->pmslen, ssl->conf->f_rng, ssl->conf->p_rng)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_dhm_calc_secret", ret); return ret; } MBEDTLS_SSL_DEBUG_MPI(3, "DHM: K ", &ssl->handshake->dhm_ctx.K); } else #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_RSA || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_RSA || ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA) { #if defined(MBEDTLS_USE_PSA_CRYPTO) psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t destruction_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_attributes_t key_attributes; mbedtls_ssl_handshake_params *handshake = ssl->handshake; header_len = 4; MBEDTLS_SSL_DEBUG_MSG(1, ("Perform PSA-based ECDH computation.")); /* * Generate EC private key for ECDHE exchange. */ /* The master secret is obtained from the shared ECDH secret by * applying the TLS 1.2 PRF with a specific salt and label. While * the PSA Crypto API encourages combining key agreement schemes * such as ECDH with fixed KDFs such as TLS 1.2 PRF, it does not * yet support the provisioning of salt + label to the KDF. * For the time being, we therefore need to split the computation * of the ECDH secret and the application of the TLS 1.2 PRF. */ key_attributes = psa_key_attributes_init(); psa_set_key_usage_flags(&key_attributes, PSA_KEY_USAGE_DERIVE); psa_set_key_algorithm(&key_attributes, PSA_ALG_ECDH); psa_set_key_type(&key_attributes, handshake->ecdh_psa_type); psa_set_key_bits(&key_attributes, handshake->ecdh_bits); /* Generate ECDH private key. */ status = psa_generate_key(&key_attributes, &handshake->ecdh_psa_privkey); if (status != PSA_SUCCESS) { return MBEDTLS_ERR_SSL_HW_ACCEL_FAILED; } /* Export the public part of the ECDH private key from PSA. * The export format is an ECPoint structure as expected by TLS, * but we just need to add a length byte before that. */ unsigned char *own_pubkey = ssl->out_msg + header_len + 1; unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN; size_t own_pubkey_max_len = (size_t) (end - own_pubkey); size_t own_pubkey_len; status = psa_export_public_key(handshake->ecdh_psa_privkey, own_pubkey, own_pubkey_max_len, &own_pubkey_len); if (status != PSA_SUCCESS) { psa_destroy_key(handshake->ecdh_psa_privkey); handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT; return MBEDTLS_ERR_SSL_HW_ACCEL_FAILED; } ssl->out_msg[header_len] = (unsigned char) own_pubkey_len; content_len = own_pubkey_len + 1; /* The ECDH secret is the premaster secret used for key derivation. */ /* Compute ECDH shared secret. */ status = psa_raw_key_agreement(PSA_ALG_ECDH, handshake->ecdh_psa_privkey, handshake->ecdh_psa_peerkey, handshake->ecdh_psa_peerkey_len, ssl->handshake->premaster, sizeof(ssl->handshake->premaster), &ssl->handshake->pmslen); destruction_status = psa_destroy_key(handshake->ecdh_psa_privkey); handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT; if (status != PSA_SUCCESS || destruction_status != PSA_SUCCESS) { return MBEDTLS_ERR_SSL_HW_ACCEL_FAILED; } #else /* * ECDH key exchange -- send client public value */ header_len = 4; #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (ssl->handshake->ecrs_enabled) { if (ssl->handshake->ecrs_state == ssl_ecrs_cke_ecdh_calc_secret) { goto ecdh_calc_secret; } mbedtls_ecdh_enable_restart(&ssl->handshake->ecdh_ctx); } #endif ret = mbedtls_ecdh_make_public(&ssl->handshake->ecdh_ctx, &content_len, &ssl->out_msg[header_len], 1000, ssl->conf->f_rng, ssl->conf->p_rng); if (ret != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecdh_make_public", ret); #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (ret == MBEDTLS_ERR_ECP_IN_PROGRESS) { ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS; } #endif return ret; } MBEDTLS_SSL_DEBUG_ECDH(3, &ssl->handshake->ecdh_ctx, MBEDTLS_DEBUG_ECDH_Q); #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (ssl->handshake->ecrs_enabled) { ssl->handshake->ecrs_n = content_len; ssl->handshake->ecrs_state = ssl_ecrs_cke_ecdh_calc_secret; } ecdh_calc_secret: if (ssl->handshake->ecrs_enabled) { content_len = ssl->handshake->ecrs_n; } #endif if ((ret = mbedtls_ecdh_calc_secret(&ssl->handshake->ecdh_ctx, &ssl->handshake->pmslen, ssl->handshake->premaster, MBEDTLS_MPI_MAX_SIZE, ssl->conf->f_rng, ssl->conf->p_rng)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecdh_calc_secret", ret); #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (ret == MBEDTLS_ERR_ECP_IN_PROGRESS) { ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS; } #endif return ret; } MBEDTLS_SSL_DEBUG_ECDH(3, &ssl->handshake->ecdh_ctx, MBEDTLS_DEBUG_ECDH_Z); #endif /* MBEDTLS_USE_PSA_CRYPTO */ } else #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ #if defined(MBEDTLS_USE_PSA_CRYPTO) && \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; psa_status_t destruction_status = PSA_ERROR_CORRUPTION_DETECTED; psa_key_attributes_t key_attributes; mbedtls_ssl_handshake_params *handshake = ssl->handshake; /* * opaque psk_identity<0..2^16-1>; */ if (mbedtls_ssl_conf_has_static_psk(ssl->conf) == 0) { /* We don't offer PSK suites if we don't have a PSK, * and we check that the server's choice is among the * ciphersuites we offered, so this should never happen. */ return MBEDTLS_ERR_SSL_INTERNAL_ERROR; } /* uint16 to store content length */ const size_t content_len_size = 2; header_len = 4; if (header_len + content_len_size + ssl->conf->psk_identity_len > MBEDTLS_SSL_OUT_CONTENT_LEN) { MBEDTLS_SSL_DEBUG_MSG(1, ("psk identity too long or SSL buffer too short")); return MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL; } unsigned char *p = ssl->out_msg + header_len; *p++ = MBEDTLS_BYTE_1(ssl->conf->psk_identity_len); *p++ = MBEDTLS_BYTE_0(ssl->conf->psk_identity_len); header_len += content_len_size; memcpy(p, ssl->conf->psk_identity, ssl->conf->psk_identity_len); p += ssl->conf->psk_identity_len; header_len += ssl->conf->psk_identity_len; MBEDTLS_SSL_DEBUG_MSG(1, ("Perform PSA-based ECDH computation.")); /* * Generate EC private key for ECDHE exchange. */ /* The master secret is obtained from the shared ECDH secret by * applying the TLS 1.2 PRF with a specific salt and label. While * the PSA Crypto API encourages combining key agreement schemes * such as ECDH with fixed KDFs such as TLS 1.2 PRF, it does not * yet support the provisioning of salt + label to the KDF. * For the time being, we therefore need to split the computation * of the ECDH secret and the application of the TLS 1.2 PRF. */ key_attributes = psa_key_attributes_init(); psa_set_key_usage_flags(&key_attributes, PSA_KEY_USAGE_DERIVE); psa_set_key_algorithm(&key_attributes, PSA_ALG_ECDH); psa_set_key_type(&key_attributes, handshake->ecdh_psa_type); psa_set_key_bits(&key_attributes, handshake->ecdh_bits); /* Generate ECDH private key. */ status = psa_generate_key(&key_attributes, &handshake->ecdh_psa_privkey); if (status != PSA_SUCCESS) { return psa_ssl_status_to_mbedtls(status); } /* Export the public part of the ECDH private key from PSA. * The export format is an ECPoint structure as expected by TLS, * but we just need to add a length byte before that. */ unsigned char *own_pubkey = p + 1; unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN; size_t own_pubkey_max_len = (size_t) (end - own_pubkey); size_t own_pubkey_len = 0; status = psa_export_public_key(handshake->ecdh_psa_privkey, own_pubkey, own_pubkey_max_len, &own_pubkey_len); if (status != PSA_SUCCESS) { psa_destroy_key(handshake->ecdh_psa_privkey); handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT; return psa_ssl_status_to_mbedtls(status); } *p = (unsigned char) own_pubkey_len; content_len = own_pubkey_len + 1; /* As RFC 5489 section 2, the premaster secret is formed as follows: * - a uint16 containing the length (in octets) of the ECDH computation * - the octet string produced by the ECDH computation * - a uint16 containing the length (in octets) of the PSK * - the PSK itself */ unsigned char *pms = ssl->handshake->premaster; const unsigned char * const pms_end = pms + sizeof(ssl->handshake->premaster); /* uint16 to store length (in octets) of the ECDH computation */ const size_t zlen_size = 2; size_t zlen = 0; /* Perform ECDH computation after the uint16 reserved for the length */ status = psa_raw_key_agreement(PSA_ALG_ECDH, handshake->ecdh_psa_privkey, handshake->ecdh_psa_peerkey, handshake->ecdh_psa_peerkey_len, pms + zlen_size, pms_end - (pms + zlen_size), &zlen); destruction_status = psa_destroy_key(handshake->ecdh_psa_privkey); handshake->ecdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT; if (status != PSA_SUCCESS) { return psa_ssl_status_to_mbedtls(status); } else if (destruction_status != PSA_SUCCESS) { return psa_ssl_status_to_mbedtls(destruction_status); } /* Write the ECDH computation length before the ECDH computation */ MBEDTLS_PUT_UINT16_BE(zlen, pms, 0); pms += zlen_size + zlen; } else #endif /* MBEDTLS_USE_PSA_CRYPTO && MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) if (mbedtls_ssl_ciphersuite_uses_psk(ciphersuite_info)) { /* * opaque psk_identity<0..2^16-1>; */ if (mbedtls_ssl_conf_has_static_psk(ssl->conf) == 0) { /* We don't offer PSK suites if we don't have a PSK, * and we check that the server's choice is among the * ciphersuites we offered, so this should never happen. */ return MBEDTLS_ERR_SSL_INTERNAL_ERROR; } header_len = 4; content_len = ssl->conf->psk_identity_len; if (header_len + 2 + content_len > MBEDTLS_SSL_OUT_CONTENT_LEN) { MBEDTLS_SSL_DEBUG_MSG(1, ("psk identity too long or SSL buffer too short")); return MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL; } ssl->out_msg[header_len++] = MBEDTLS_BYTE_1(content_len); ssl->out_msg[header_len++] = MBEDTLS_BYTE_0(content_len); memcpy(ssl->out_msg + header_len, ssl->conf->psk_identity, ssl->conf->psk_identity_len); header_len += ssl->conf->psk_identity_len; #if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK) { content_len = 0; } else #endif #if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK) { if ((ret = ssl_write_encrypted_pms(ssl, header_len, &content_len, 2)) != 0) { return ret; } } else #endif #if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK) { /* * ClientDiffieHellmanPublic public (DHM send G^X mod P) */ content_len = mbedtls_dhm_get_len(&ssl->handshake->dhm_ctx); if (header_len + 2 + content_len > MBEDTLS_SSL_OUT_CONTENT_LEN) { MBEDTLS_SSL_DEBUG_MSG(1, ("psk identity or DHM size too long or SSL buffer too short")); return MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL; } ssl->out_msg[header_len++] = MBEDTLS_BYTE_1(content_len); ssl->out_msg[header_len++] = MBEDTLS_BYTE_0(content_len); ret = mbedtls_dhm_make_public(&ssl->handshake->dhm_ctx, (int) mbedtls_dhm_get_len(&ssl->handshake->dhm_ctx), &ssl->out_msg[header_len], content_len, ssl->conf->f_rng, ssl->conf->p_rng); if (ret != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_dhm_make_public", ret); return ret; } #if defined(MBEDTLS_USE_PSA_CRYPTO) unsigned char *pms = ssl->handshake->premaster; unsigned char *pms_end = pms + sizeof(ssl->handshake->premaster); size_t pms_len; /* Write length only when we know the actual value */ if ((ret = mbedtls_dhm_calc_secret(&ssl->handshake->dhm_ctx, pms + 2, pms_end - (pms + 2), &pms_len, ssl->conf->f_rng, ssl->conf->p_rng)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_dhm_calc_secret", ret); return ret; } MBEDTLS_PUT_UINT16_BE(pms_len, pms, 0); pms += 2 + pms_len; MBEDTLS_SSL_DEBUG_MPI(3, "DHM: K ", &ssl->handshake->dhm_ctx.K); #endif } else #endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */ #if !defined(MBEDTLS_USE_PSA_CRYPTO) && \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK) { /* * ClientECDiffieHellmanPublic public; */ ret = mbedtls_ecdh_make_public(&ssl->handshake->ecdh_ctx, &content_len, &ssl->out_msg[header_len], MBEDTLS_SSL_OUT_CONTENT_LEN - header_len, ssl->conf->f_rng, ssl->conf->p_rng); if (ret != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecdh_make_public", ret); return ret; } MBEDTLS_SSL_DEBUG_ECDH(3, &ssl->handshake->ecdh_ctx, MBEDTLS_DEBUG_ECDH_Q); } else #endif /* !MBEDTLS_USE_PSA_CRYPTO && MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */ { MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); return MBEDTLS_ERR_SSL_INTERNAL_ERROR; } #if !defined(MBEDTLS_USE_PSA_CRYPTO) if ((ret = mbedtls_ssl_psk_derive_premaster(ssl, ciphersuite_info->key_exchange)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_psk_derive_premaster", ret); return ret; } #endif /* !MBEDTLS_USE_PSA_CRYPTO */ } else #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA) { header_len = 4; if ((ret = ssl_write_encrypted_pms(ssl, header_len, &content_len, 0)) != 0) { return ret; } } else #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */ #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE) { header_len = 4; #if defined(MBEDTLS_USE_PSA_CRYPTO) unsigned char *out_p = ssl->out_msg + header_len; unsigned char *end_p = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN - header_len; ret = mbedtls_psa_ecjpake_write_round(&ssl->handshake->psa_pake_ctx, out_p, end_p - out_p, &content_len, MBEDTLS_ECJPAKE_ROUND_TWO); if (ret != 0) { psa_destroy_key(ssl->handshake->psa_pake_password); psa_pake_abort(&ssl->handshake->psa_pake_ctx); MBEDTLS_SSL_DEBUG_RET(1, "psa_pake_output", ret); return ret; } #else ret = mbedtls_ecjpake_write_round_two(&ssl->handshake->ecjpake_ctx, ssl->out_msg + header_len, MBEDTLS_SSL_OUT_CONTENT_LEN - header_len, &content_len, ssl->conf->f_rng, ssl->conf->p_rng); if (ret != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecjpake_write_round_two", ret); return ret; } ret = mbedtls_ecjpake_derive_secret(&ssl->handshake->ecjpake_ctx, ssl->handshake->premaster, 32, &ssl->handshake->pmslen, ssl->conf->f_rng, ssl->conf->p_rng); if (ret != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecjpake_derive_secret", ret); return ret; } #endif /* MBEDTLS_USE_PSA_CRYPTO */ } else #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */ { ((void) ciphersuite_info); MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); return MBEDTLS_ERR_SSL_INTERNAL_ERROR; } ssl->out_msglen = header_len + content_len; ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; ssl->out_msg[0] = MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE; ssl->state++; if ((ret = mbedtls_ssl_write_handshake_msg(ssl)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_write_handshake_msg", ret); return ret; } MBEDTLS_SSL_DEBUG_MSG(2, ("<= write client key exchange")); return 0; } #if !defined(MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_write_certificate_verify(mbedtls_ssl_context *ssl) { const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info; int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; MBEDTLS_SSL_DEBUG_MSG(2, ("=> write certificate verify")); if ((ret = mbedtls_ssl_derive_keys(ssl)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_derive_keys", ret); return ret; } if (!mbedtls_ssl_ciphersuite_cert_req_allowed(ciphersuite_info)) { MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip write certificate verify")); ssl->state++; return 0; } MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); return MBEDTLS_ERR_SSL_INTERNAL_ERROR; } #else /* !MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */ MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_write_certificate_verify(mbedtls_ssl_context *ssl) { int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; const mbedtls_ssl_ciphersuite_t *ciphersuite_info = ssl->handshake->ciphersuite_info; size_t n = 0, offset = 0; unsigned char hash[48]; unsigned char *hash_start = hash; mbedtls_md_type_t md_alg = MBEDTLS_MD_NONE; size_t hashlen; void *rs_ctx = NULL; #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) size_t out_buf_len = ssl->out_buf_len - (ssl->out_msg - ssl->out_buf); #else size_t out_buf_len = MBEDTLS_SSL_OUT_BUFFER_LEN - (ssl->out_msg - ssl->out_buf); #endif MBEDTLS_SSL_DEBUG_MSG(2, ("=> write certificate verify")); #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (ssl->handshake->ecrs_enabled && ssl->handshake->ecrs_state == ssl_ecrs_crt_vrfy_sign) { goto sign; } #endif if ((ret = mbedtls_ssl_derive_keys(ssl)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_derive_keys", ret); return ret; } if (!mbedtls_ssl_ciphersuite_cert_req_allowed(ciphersuite_info)) { MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip write certificate verify")); ssl->state++; return 0; } if (ssl->handshake->client_auth == 0 || mbedtls_ssl_own_cert(ssl) == NULL) { MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip write certificate verify")); ssl->state++; return 0; } if (mbedtls_ssl_own_key(ssl) == NULL) { MBEDTLS_SSL_DEBUG_MSG(1, ("got no private key for certificate")); return MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED; } /* * Make a signature of the handshake digests */ #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (ssl->handshake->ecrs_enabled) { ssl->handshake->ecrs_state = ssl_ecrs_crt_vrfy_sign; } sign: #endif ssl->handshake->calc_verify(ssl, hash, &hashlen); /* * digitally-signed struct { * opaque handshake_messages[handshake_messages_length]; * }; * * Taking shortcut here. We assume that the server always allows the * PRF Hash function and has sent it in the allowed signature * algorithms list received in the Certificate Request message. * * Until we encounter a server that does not, we will take this * shortcut. * * Reason: Otherwise we should have running hashes for SHA512 and * SHA224 in order to satisfy 'weird' needs from the server * side. */ if (ssl->handshake->ciphersuite_info->mac == MBEDTLS_MD_SHA384) { md_alg = MBEDTLS_MD_SHA384; ssl->out_msg[4] = MBEDTLS_SSL_HASH_SHA384; } else { md_alg = MBEDTLS_MD_SHA256; ssl->out_msg[4] = MBEDTLS_SSL_HASH_SHA256; } ssl->out_msg[5] = mbedtls_ssl_sig_from_pk(mbedtls_ssl_own_key(ssl)); /* Info from md_alg will be used instead */ hashlen = 0; offset = 2; #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (ssl->handshake->ecrs_enabled) { rs_ctx = &ssl->handshake->ecrs_ctx.pk; } #endif if ((ret = mbedtls_pk_sign_restartable(mbedtls_ssl_own_key(ssl), md_alg, hash_start, hashlen, ssl->out_msg + 6 + offset, out_buf_len - 6 - offset, &n, ssl->conf->f_rng, ssl->conf->p_rng, rs_ctx)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_pk_sign", ret); #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if (ret == MBEDTLS_ERR_ECP_IN_PROGRESS) { ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS; } #endif return ret; } MBEDTLS_PUT_UINT16_BE(n, ssl->out_msg, offset + 4); ssl->out_msglen = 6 + n + offset; ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; ssl->out_msg[0] = MBEDTLS_SSL_HS_CERTIFICATE_VERIFY; ssl->state++; if ((ret = mbedtls_ssl_write_handshake_msg(ssl)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_write_handshake_msg", ret); return ret; } MBEDTLS_SSL_DEBUG_MSG(2, ("<= write certificate verify")); return ret; } #endif /* MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_new_session_ticket(mbedtls_ssl_context *ssl) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; uint32_t lifetime; size_t ticket_len; unsigned char *ticket; const unsigned char *msg; MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse new session ticket")); if ((ret = mbedtls_ssl_read_record(ssl, 1)) != 0) { MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_read_record", ret); return ret; } if (ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad new session ticket message")); mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE); return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; } /* * struct { * uint32 ticket_lifetime_hint; * opaque ticket<0..2^16-1>; * } NewSessionTicket; * * 0 . 3 ticket_lifetime_hint * 4 . 5 ticket_len (n) * 6 . 5+n ticket content */ if (ssl->in_msg[0] != MBEDTLS_SSL_HS_NEW_SESSION_TICKET || ssl->in_hslen < 6 + mbedtls_ssl_hs_hdr_len(ssl)) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad new session ticket message")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } msg = ssl->in_msg + mbedtls_ssl_hs_hdr_len(ssl); lifetime = (((uint32_t) msg[0]) << 24) | (msg[1] << 16) | (msg[2] << 8) | (msg[3]); ticket_len = (msg[4] << 8) | (msg[5]); if (ticket_len + 6 + mbedtls_ssl_hs_hdr_len(ssl) != ssl->in_hslen) { MBEDTLS_SSL_DEBUG_MSG(1, ("bad new session ticket message")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); return MBEDTLS_ERR_SSL_DECODE_ERROR; } MBEDTLS_SSL_DEBUG_MSG(3, ("ticket length: %" MBEDTLS_PRINTF_SIZET, ticket_len)); /* We're not waiting for a NewSessionTicket message any more */ ssl->handshake->new_session_ticket = 0; ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC; /* * Zero-length ticket means the server changed his mind and doesn't want * to send a ticket after all, so just forget it */ if (ticket_len == 0) { return 0; } if (ssl->session != NULL && ssl->session->ticket != NULL) { mbedtls_platform_zeroize(ssl->session->ticket, ssl->session->ticket_len); mbedtls_free(ssl->session->ticket); ssl->session->ticket = NULL; ssl->session->ticket_len = 0; } mbedtls_platform_zeroize(ssl->session_negotiate->ticket, ssl->session_negotiate->ticket_len); mbedtls_free(ssl->session_negotiate->ticket); ssl->session_negotiate->ticket = NULL; ssl->session_negotiate->ticket_len = 0; if ((ticket = mbedtls_calloc(1, ticket_len)) == NULL) { MBEDTLS_SSL_DEBUG_MSG(1, ("ticket alloc failed")); mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR); return MBEDTLS_ERR_SSL_ALLOC_FAILED; } memcpy(ticket, msg + 6, ticket_len); ssl->session_negotiate->ticket = ticket; ssl->session_negotiate->ticket_len = ticket_len; ssl->session_negotiate->ticket_lifetime = lifetime; /* * RFC 5077 section 3.4: * "If the client receives a session ticket from the server, then it * discards any Session ID that was sent in the ServerHello." */ MBEDTLS_SSL_DEBUG_MSG(3, ("ticket in use, discarding session id")); ssl->session_negotiate->id_len = 0; MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse new session ticket")); return 0; } #endif /* MBEDTLS_SSL_SESSION_TICKETS */ /* * SSL handshake -- client side -- single step */ int mbedtls_ssl_handshake_client_step(mbedtls_ssl_context *ssl) { int ret = 0; /* Change state now, so that it is right in mbedtls_ssl_read_record(), used * by DTLS for dropping out-of-sequence ChangeCipherSpec records */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) if (ssl->state == MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC && ssl->handshake->new_session_ticket != 0) { ssl->state = MBEDTLS_SSL_NEW_SESSION_TICKET; } #endif switch (ssl->state) { case MBEDTLS_SSL_HELLO_REQUEST: ssl->state = MBEDTLS_SSL_CLIENT_HELLO; break; /* * ==> ClientHello */ case MBEDTLS_SSL_CLIENT_HELLO: ret = mbedtls_ssl_write_client_hello(ssl); break; /* * <== ServerHello * Certificate * ( ServerKeyExchange ) * ( CertificateRequest ) * ServerHelloDone */ case MBEDTLS_SSL_SERVER_HELLO: ret = ssl_parse_server_hello(ssl); break; case MBEDTLS_SSL_SERVER_CERTIFICATE: ret = mbedtls_ssl_parse_certificate(ssl); break; case MBEDTLS_SSL_SERVER_KEY_EXCHANGE: ret = ssl_parse_server_key_exchange(ssl); break; case MBEDTLS_SSL_CERTIFICATE_REQUEST: ret = ssl_parse_certificate_request(ssl); break; case MBEDTLS_SSL_SERVER_HELLO_DONE: ret = ssl_parse_server_hello_done(ssl); break; /* * ==> ( Certificate/Alert ) * ClientKeyExchange * ( CertificateVerify ) * ChangeCipherSpec * Finished */ case MBEDTLS_SSL_CLIENT_CERTIFICATE: ret = mbedtls_ssl_write_certificate(ssl); break; case MBEDTLS_SSL_CLIENT_KEY_EXCHANGE: ret = ssl_write_client_key_exchange(ssl); break; case MBEDTLS_SSL_CERTIFICATE_VERIFY: ret = ssl_write_certificate_verify(ssl); break; case MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC: ret = mbedtls_ssl_write_change_cipher_spec(ssl); break; case MBEDTLS_SSL_CLIENT_FINISHED: ret = mbedtls_ssl_write_finished(ssl); break; /* * <== ( NewSessionTicket ) * ChangeCipherSpec * Finished */ #if defined(MBEDTLS_SSL_SESSION_TICKETS) case MBEDTLS_SSL_NEW_SESSION_TICKET: ret = ssl_parse_new_session_ticket(ssl); break; #endif case MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC: ret = mbedtls_ssl_parse_change_cipher_spec(ssl); break; case MBEDTLS_SSL_SERVER_FINISHED: ret = mbedtls_ssl_parse_finished(ssl); break; case MBEDTLS_SSL_FLUSH_BUFFERS: MBEDTLS_SSL_DEBUG_MSG(2, ("handshake: done")); ssl->state = MBEDTLS_SSL_HANDSHAKE_WRAPUP; break; case MBEDTLS_SSL_HANDSHAKE_WRAPUP: mbedtls_ssl_handshake_wrapup(ssl); break; default: MBEDTLS_SSL_DEBUG_MSG(1, ("invalid state %d", ssl->state)); return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; } return ret; } #endif /* MBEDTLS_SSL_CLI_C && MBEDTLS_SSL_PROTO_TLS1_2 */