/* * 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) #if defined(MBEDTLS_PLATFORM_C) #include "mbedtls/platform.h" #else #include #define mbedtls_calloc calloc #define mbedtls_free free #endif #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 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) int mbedtls_ssl_conf_has_static_psk( mbedtls_ssl_config const *conf ) { if( conf->psk_identity == NULL || conf->psk_identity_len == 0 ) { return( 0 ); } #if defined(MBEDTLS_USE_PSA_CRYPTO) if( ! mbedtls_svc_key_id_is_null( conf->psk_opaque ) ) return( 1 ); #endif /* MBEDTLS_USE_PSA_CRYPTO */ if( conf->psk != NULL && conf->psk_len != 0 ) return( 1 ); return( 0 ); } #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */ #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 an 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; *olen = 0; /* Skip costly extension if we can't use EC J-PAKE anyway */ if( mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 ) return( 0 ); 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" ) ); 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 ); } 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; /* * Quoting draft-ietf-tls-dtls-connection-id-05 * https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05 * * 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_KEY_EXCHANGE_ECJPAKE_ENABLED) mbedtls_ecjpake_set_point_format( &ssl->handshake->ecjpake_ctx, p[0] ); #endif 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( ( 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_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; unsigned char cookie_len; 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->verify_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->verify_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->compression != comp || 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->compression = comp; ssl->session_negotiate->id_len = n; memcpy( ssl->session_negotiate->id, buf + 35, n ); } else { ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC; 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 ); } } 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 ); } ssl->session_negotiate->compression = comp; 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 ); } } /* * 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_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) #if defined(MBEDTLS_USE_PSA_CRYPTO) 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; size_t ecdh_bits = 0; uint8_t ecpoint_len; mbedtls_ssl_handshake_params *handshake = ssl->handshake; /* * 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 group to PSA key type. */ if( ( handshake->ecdh_psa_type = mbedtls_psa_parse_tls_ecc_group( tls_id, &ecdh_bits ) ) == 0 ) { return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE ); } handshake->ecdh_bits = ecdh_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 ); } #else MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_check_server_ecdh_params( const mbedtls_ssl_context *ssl ) { const mbedtls_ecp_curve_info *curve_info; 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 curve_info = mbedtls_ecp_curve_info_from_grp_id( grp_id ); if( curve_info == NULL ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); } MBEDTLS_SSL_DEBUG_MSG( 2, ( "ECDH curve: %s", curve_info->name ) ); 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 ); } 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_USE_PSA_CRYPTO */ #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */ #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 PKS identity hint, as we only allow one * PSK to be provisionned 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_DHE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) MBEDTLS_CHECK_RETURN_CRITICAL static int ssl_parse_signature_algorithm( mbedtls_ssl_context *ssl, unsigned char **p, unsigned char *end, mbedtls_md_type_t *md_alg, mbedtls_pk_type_t *pk_alg ) { *md_alg = MBEDTLS_MD_NONE; *pk_alg = MBEDTLS_PK_NONE; if( (*p) + 2 > end ) return( MBEDTLS_ERR_SSL_DECODE_ERROR ); /* * Get hash algorithm */ if( ( *md_alg = mbedtls_ssl_md_alg_from_hash( (*p)[0] ) ) == MBEDTLS_MD_NONE ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Server used unsupported HashAlgorithm %d", *(p)[0] ) ); return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE ); } /* * Get signature algorithm */ if( ( *pk_alg = mbedtls_ssl_pk_alg_from_sig( (*p)[1] ) ) == MBEDTLS_PK_NONE ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "server used unsupported SignatureAlgorithm %d", (*p)[1] ) ); return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE ); } /* * Check if the signature algorithm is acceptable */ if( !mbedtls_ssl_sig_alg_is_offered( ssl, MBEDTLS_GET_UINT16_BE( *p, 0 ) ) ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "server used HashAlgorithm %d that was not offered", *(p)[0] ) ); return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE ); } MBEDTLS_SSL_DEBUG_MSG( 2, ( "Server used SignatureAlgorithm %d", (*p)[1] ) ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "Server used HashAlgorithm %d", (*p)[0] ) ); *p += 2; return( 0 ); } #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED || MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_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 ecdh_bits = 0; size_t olen = 0; 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 ); } ssl->handshake->ecdh_psa_type = PSA_KEY_TYPE_ECC_KEY_PAIR( mbedtls_ecc_group_to_psa( peer_key->grp.id, &ecdh_bits ) ); if( ssl->handshake->ecdh_psa_type == 0 || ecdh_bits > 0xffff ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "Invalid ecc group conversion to psa." ) ); return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER ); } ssl->handshake->ecdh_bits = (uint16_t) ecdh_bits; /* 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 ) { 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 ); } } 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; #if defined(MBEDTLS_USE_PSA_CRYPTO) unsigned char hash[PSA_HASH_MAX_SIZE]; #else unsigned char hash[MBEDTLS_MD_MAX_SIZE]; #endif 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; mbedtls_pk_context * peer_pk; /* * Handle the digitally-signed structure */ if( ssl_parse_signature_algorithm( ssl, &p, end, &md_alg, &pk_alg ) != 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 ); } if( pk_alg != mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info ) ) { 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 ); #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 */ /* * 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( ( ret = mbedtls_pk_verify_restartable( peer_pk, md_alg, hash, hashlen, p, sig_len, rs_ctx ) ) != 0 ) { #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED) if( ret != MBEDTLS_ERR_ECP_IN_PROGRESS ) #endif 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; #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: %d,%d", 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 ); } 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; 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 ); } } 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_SERVER_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_SERVER_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 */