diff options
Diffstat (limited to 'thirdparty/mbedtls/library/ssl_tls12_server.c')
-rw-r--r-- | thirdparty/mbedtls/library/ssl_tls12_server.c | 4432 |
1 files changed, 4432 insertions, 0 deletions
diff --git a/thirdparty/mbedtls/library/ssl_tls12_server.c b/thirdparty/mbedtls/library/ssl_tls12_server.c new file mode 100644 index 0000000000..b49a8ae6a6 --- /dev/null +++ b/thirdparty/mbedtls/library/ssl_tls12_server.c @@ -0,0 +1,4432 @@ +/* + * TLS server-side functions + * + * Copyright The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later + */ + +#include "common.h" + +#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_PROTO_TLS1_2) + +#include "mbedtls/platform.h" + +#include "mbedtls/ssl.h" +#include "ssl_misc.h" +#include "debug_internal.h" +#include "mbedtls/error.h" +#include "mbedtls/platform_util.h" +#include "constant_time_internal.h" +#include "mbedtls/constant_time.h" + +#include <string.h> + +#if defined(MBEDTLS_USE_PSA_CRYPTO) +/* Define a local translating function to save code size by not using too many + * arguments in each translating place. */ +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDH_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDHE_ENABLED) +static int local_err_translation(psa_status_t status) +{ + return psa_status_to_mbedtls(status, psa_to_ssl_errors, + ARRAY_LENGTH(psa_to_ssl_errors), + psa_generic_status_to_mbedtls); +} +#define PSA_TO_MBEDTLS_ERR(status) local_err_translation(status) +#endif +#endif + +#if defined(MBEDTLS_ECP_C) +#include "mbedtls/ecp.h" +#endif + +#if defined(MBEDTLS_HAVE_TIME) +#include "mbedtls/platform_time.h" +#endif + +#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) +int mbedtls_ssl_set_client_transport_id(mbedtls_ssl_context *ssl, + const unsigned char *info, + size_t ilen) +{ + if (ssl->conf->endpoint != MBEDTLS_SSL_IS_SERVER) { + return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; + } + + mbedtls_free(ssl->cli_id); + + if ((ssl->cli_id = mbedtls_calloc(1, ilen)) == NULL) { + return MBEDTLS_ERR_SSL_ALLOC_FAILED; + } + + memcpy(ssl->cli_id, info, ilen); + ssl->cli_id_len = ilen; + + return 0; +} + +void mbedtls_ssl_conf_dtls_cookies(mbedtls_ssl_config *conf, + mbedtls_ssl_cookie_write_t *f_cookie_write, + mbedtls_ssl_cookie_check_t *f_cookie_check, + void *p_cookie) +{ + conf->f_cookie_write = f_cookie_write; + conf->f_cookie_check = f_cookie_check; + conf->p_cookie = p_cookie; +} +#endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */ + +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_conf_has_psk_or_cb(mbedtls_ssl_config const *conf) +{ + if (conf->f_psk != NULL) { + return 1; + } + + if (conf->psk_identity_len == 0 || conf->psk_identity == NULL) { + 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 */ + +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 || + buf[0] != ssl->verify_data_len || + mbedtls_ct_memcmp(buf + 1, 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] != 0x0) { + 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_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) +/* + * Function for parsing a supported groups (TLS 1.3) or supported elliptic + * curves (TLS 1.2) extension. + * + * The "extension_data" field of a supported groups extension contains a + * "NamedGroupList" value (TLS 1.3 RFC8446): + * enum { + * secp256r1(0x0017), secp384r1(0x0018), secp521r1(0x0019), + * x25519(0x001D), x448(0x001E), + * ffdhe2048(0x0100), ffdhe3072(0x0101), ffdhe4096(0x0102), + * ffdhe6144(0x0103), ffdhe8192(0x0104), + * ffdhe_private_use(0x01FC..0x01FF), + * ecdhe_private_use(0xFE00..0xFEFF), + * (0xFFFF) + * } NamedGroup; + * struct { + * NamedGroup named_group_list<2..2^16-1>; + * } NamedGroupList; + * + * The "extension_data" field of a supported elliptic curves extension contains + * a "NamedCurveList" value (TLS 1.2 RFC 8422): + * enum { + * deprecated(1..22), + * secp256r1 (23), secp384r1 (24), secp521r1 (25), + * x25519(29), x448(30), + * reserved (0xFE00..0xFEFF), + * deprecated(0xFF01..0xFF02), + * (0xFFFF) + * } NamedCurve; + * struct { + * NamedCurve named_curve_list<2..2^16-1> + * } NamedCurveList; + * + * The TLS 1.3 supported groups extension was defined to be a compatible + * generalization of the TLS 1.2 supported elliptic curves extension. They both + * share the same extension identifier. + * + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_parse_supported_groups_ext(mbedtls_ssl_context *ssl, + const unsigned char *buf, + size_t len) +{ + size_t list_size, our_size; + const unsigned char *p; + uint16_t *curves_tls_id; + + if (len < 2) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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 = MBEDTLS_GET_UINT16_BE(buf, 0); + if (list_size + 2 != len || + list_size % 2 != 0) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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; + } + + /* Should never happen unless client duplicates the extension */ + if (ssl->handshake->curves_tls_id != NULL) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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; + } + + /* Don't allow our peer to make us allocate too much memory, + * and leave room for a final 0 */ + our_size = list_size / 2 + 1; + if (our_size > MBEDTLS_ECP_DP_MAX) { + our_size = MBEDTLS_ECP_DP_MAX; + } + + if ((curves_tls_id = mbedtls_calloc(our_size, + sizeof(*curves_tls_id))) == NULL) { + mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, + MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR); + return MBEDTLS_ERR_SSL_ALLOC_FAILED; + } + + ssl->handshake->curves_tls_id = curves_tls_id; + + p = buf + 2; + while (list_size > 0 && our_size > 1) { + uint16_t curr_tls_id = MBEDTLS_GET_UINT16_BE(p, 0); + + if (mbedtls_ssl_get_ecp_group_id_from_tls_id(curr_tls_id) != + MBEDTLS_ECP_DP_NONE) { + *curves_tls_id++ = curr_tls_id; + our_size--; + } + + list_size -= 2; + p += 2; + } + + return 0; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_parse_supported_point_formats(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 client 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_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED) + ssl->handshake->ecdh_ctx.point_format = p[0]; +#endif /* !MBEDTLS_USE_PSA_CRYPTO && MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED */ +#if !defined(MBEDTLS_USE_PSA_CRYPTO) && \ + defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) + mbedtls_ecjpake_set_point_format(&ssl->handshake->ecjpake_ctx, + p[0]); +#endif /* !MBEDTLS_USE_PSA_CRYPTO && MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ + MBEDTLS_SSL_DEBUG_MSG(4, ("point format selected: %d", p[0])); + return 0; + } + + list_size--; + p++; + } + + return 0; +} +#endif /* MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED || + MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED || + 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 defined(MBEDTLS_USE_PSA_CRYPTO) + if (ssl->handshake->psa_pake_ctx_is_ok != 1) +#else + if (mbedtls_ecjpake_check(&ssl->handshake->ecjpake_ctx) != 0) +#endif /* MBEDTLS_USE_PSA_CRYPTO */ + { + MBEDTLS_SSL_DEBUG_MSG(3, ("skip ecjpake kkpp extension")); + return 0; + } + +#if defined(MBEDTLS_USE_PSA_CRYPTO) + if ((ret = mbedtls_psa_ecjpake_read_round( + &ssl->handshake->psa_pake_ctx, buf, len, + MBEDTLS_ECJPAKE_ROUND_ONE)) != 0) { + psa_destroy_key(ssl->handshake->psa_pake_password); + psa_pake_abort(&ssl->handshake->psa_pake_ctx); + + MBEDTLS_SSL_DEBUG_RET(1, "psa_pake_input round one", ret); + mbedtls_ssl_send_alert_message( + ssl, + MBEDTLS_SSL_ALERT_LEVEL_FATAL, + MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); + + return ret; + } +#else + if ((ret = mbedtls_ecjpake_read_round_one(&ssl->handshake->ecjpake_ctx, + buf, len)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecjpake_read_round_one", ret); + mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, + MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER); + return ret; + } +#endif /* MBEDTLS_USE_PSA_CRYPTO */ + + /* Only mark the extension as OK when we're sure it is */ + ssl->handshake->cli_exts |= MBEDTLS_TLS_EXT_ECJPAKE_KKPP_OK; + + return 0; +} +#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ + +#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) +{ + if (len != 1 || buf[0] >= MBEDTLS_SSL_MAX_FRAG_LEN_INVALID) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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->mfl_code = buf[0]; + + 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; + + /* CID extension only makes sense in DTLS */ + if (ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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; + } + + /* + * struct { + * opaque cid<0..2^8-1>; + * } ConnectionId; + */ + + if (len < 1) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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; + } + + peer_cid_len = *buf++; + len--; + + if (len != peer_cid_len) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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; + } + + /* Ignore CID if the user has disabled its use. */ + if (ssl->negotiate_cid == MBEDTLS_SSL_CID_DISABLED) { + /* Leave ssl->handshake->cid_in_use in its default + * value of MBEDTLS_SSL_CID_DISABLED. */ + MBEDTLS_SSL_DEBUG_MSG(3, ("Client sent CID extension, but CID disabled")); + return 0; + } + + if (peer_cid_len > MBEDTLS_SSL_CID_OUT_LEN_MAX) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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->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, "Client 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 (len != 0) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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; + } + + ((void) buf); + + if (ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED) { + 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 (len != 0) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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; + } + + ((void) buf); + + if (ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_ENABLED) { + 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, + unsigned char *buf, + size_t len) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + mbedtls_ssl_session session; + + mbedtls_ssl_session_init(&session); + + if (ssl->conf->f_ticket_parse == NULL || + ssl->conf->f_ticket_write == NULL) { + return 0; + } + + /* Remember the client asked us to send a new ticket */ + ssl->handshake->new_session_ticket = 1; + + MBEDTLS_SSL_DEBUG_MSG(3, ("ticket length: %" MBEDTLS_PRINTF_SIZET, len)); + + if (len == 0) { + return 0; + } + +#if defined(MBEDTLS_SSL_RENEGOTIATION) + if (ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE) { + MBEDTLS_SSL_DEBUG_MSG(3, ("ticket rejected: renegotiating")); + return 0; + } +#endif /* MBEDTLS_SSL_RENEGOTIATION */ + + /* + * Failures are ok: just ignore the ticket and proceed. + */ + if ((ret = ssl->conf->f_ticket_parse(ssl->conf->p_ticket, &session, + buf, len)) != 0) { + mbedtls_ssl_session_free(&session); + + if (ret == MBEDTLS_ERR_SSL_INVALID_MAC) { + MBEDTLS_SSL_DEBUG_MSG(3, ("ticket is not authentic")); + } else if (ret == MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED) { + MBEDTLS_SSL_DEBUG_MSG(3, ("ticket is expired")); + } else { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_ticket_parse", ret); + } + + return 0; + } + + /* + * Keep the session ID sent by the client, since we MUST send it back to + * inform them we're accepting the ticket (RFC 5077 section 3.4) + */ + session.id_len = ssl->session_negotiate->id_len; + memcpy(&session.id, ssl->session_negotiate->id, session.id_len); + + mbedtls_ssl_session_free(ssl->session_negotiate); + memcpy(ssl->session_negotiate, &session, sizeof(mbedtls_ssl_session)); + + /* Zeroize instead of free as we copied the content */ + mbedtls_platform_zeroize(&session, sizeof(mbedtls_ssl_session)); + + MBEDTLS_SSL_DEBUG_MSG(3, ("session successfully restored from ticket")); + + ssl->handshake->resume = 1; + + /* Don't send a new ticket after all, this one is OK */ + ssl->handshake->new_session_ticket = 0; + + return 0; +} +#endif /* MBEDTLS_SSL_SESSION_TICKETS */ + +#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 client_protection = MBEDTLS_TLS_SRTP_UNSET; + size_t i, j; + size_t profile_length; + uint16_t mki_length; + /*! 2 bytes for profile length and 1 byte for mki len */ + const size_t size_of_lengths = 3; + + /* 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; + } + + /* RFC5764 section 4.1.1 + * uint8 SRTPProtectionProfile[2]; + * + * struct { + * SRTPProtectionProfiles SRTPProtectionProfiles; + * opaque srtp_mki<0..255>; + * } UseSRTPData; + + * SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>; + */ + + /* + * Min length is 5: at least one protection profile(2 bytes) + * and length(2 bytes) + srtp_mki length(1 byte) + * Check here that we have at least 2 bytes of protection profiles length + * and one of srtp_mki length + */ + if (len < size_of_lengths) { + mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, + MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + ssl->dtls_srtp_info.chosen_dtls_srtp_profile = MBEDTLS_TLS_SRTP_UNSET; + + /* first 2 bytes are protection profile length(in bytes) */ + profile_length = (buf[0] << 8) | buf[1]; + buf += 2; + + /* The profile length cannot be bigger than input buffer size - lengths fields */ + if (profile_length > len - size_of_lengths || + profile_length % 2 != 0) { /* profiles are 2 bytes long, so the length must be even */ + mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, + MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + /* + * parse the extension list values are defined in + * http://www.iana.org/assignments/srtp-protection/srtp-protection.xhtml + */ + for (j = 0; j < profile_length; j += 2) { + uint16_t protection_profile_value = buf[j] << 8 | buf[j + 1]; + client_protection = mbedtls_ssl_check_srtp_profile_value(protection_profile_value); + + if (client_protection != MBEDTLS_TLS_SRTP_UNSET) { + MBEDTLS_SSL_DEBUG_MSG(3, ("found srtp profile: %s", + mbedtls_ssl_get_srtp_profile_as_string( + client_protection))); + } else { + continue; + } + /* check if suggested profile is in our list */ + for (i = 0; i < ssl->conf->dtls_srtp_profile_list_len; i++) { + if (client_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( + client_protection))); + break; + } + } + if (ssl->dtls_srtp_info.chosen_dtls_srtp_profile != MBEDTLS_TLS_SRTP_UNSET) { + break; + } + } + buf += profile_length; /* buf points to the mki length */ + mki_length = *buf; + buf++; + + if (mki_length > MBEDTLS_TLS_SRTP_MAX_MKI_LENGTH || + mki_length + profile_length + size_of_lengths != len) { + mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, + MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + /* Parse the mki only if present and mki is supported locally */ + if (ssl->conf->dtls_srtp_mki_support == MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED && + mki_length > 0) { + ssl->dtls_srtp_info.mki_len = mki_length; + + memcpy(ssl->dtls_srtp_info.mki_value, buf, mki_length); + + MBEDTLS_SSL_DEBUG_BUF(3, "using mki", ssl->dtls_srtp_info.mki_value, + ssl->dtls_srtp_info.mki_len); + } + + return 0; +} +#endif /* MBEDTLS_SSL_DTLS_SRTP */ + +/* + * Auxiliary functions for ServerHello parsing and related actions + */ + +#if defined(MBEDTLS_X509_CRT_PARSE_C) +/* + * Return 0 if the given key uses one of the acceptable curves, -1 otherwise + */ +#if defined(MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED) +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_check_key_curve(mbedtls_pk_context *pk, + uint16_t *curves_tls_id) +{ + uint16_t *curr_tls_id = curves_tls_id; + mbedtls_ecp_group_id grp_id = mbedtls_pk_get_ec_group_id(pk); + mbedtls_ecp_group_id curr_grp_id; + + while (*curr_tls_id != 0) { + curr_grp_id = mbedtls_ssl_get_ecp_group_id_from_tls_id(*curr_tls_id); + if (curr_grp_id == grp_id) { + return 0; + } + curr_tls_id++; + } + + return -1; +} +#endif /* MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED */ + +/* + * Try picking a certificate for this ciphersuite, + * return 0 on success and -1 on failure. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_pick_cert(mbedtls_ssl_context *ssl, + const mbedtls_ssl_ciphersuite_t *ciphersuite_info) +{ + mbedtls_ssl_key_cert *cur, *list; +#if defined(MBEDTLS_USE_PSA_CRYPTO) + psa_algorithm_t pk_alg = + mbedtls_ssl_get_ciphersuite_sig_pk_psa_alg(ciphersuite_info); + psa_key_usage_t pk_usage = + mbedtls_ssl_get_ciphersuite_sig_pk_psa_usage(ciphersuite_info); +#else + mbedtls_pk_type_t pk_alg = + mbedtls_ssl_get_ciphersuite_sig_pk_alg(ciphersuite_info); +#endif /* MBEDTLS_USE_PSA_CRYPTO */ + uint32_t flags; + +#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) + if (ssl->handshake->sni_key_cert != NULL) { + list = ssl->handshake->sni_key_cert; + } else +#endif + list = ssl->conf->key_cert; + + int pk_alg_is_none = 0; +#if defined(MBEDTLS_USE_PSA_CRYPTO) + pk_alg_is_none = (pk_alg == PSA_ALG_NONE); +#else + pk_alg_is_none = (pk_alg == MBEDTLS_PK_NONE); +#endif /* MBEDTLS_USE_PSA_CRYPTO */ + if (pk_alg_is_none) { + return 0; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("ciphersuite requires certificate")); + + if (list == NULL) { + MBEDTLS_SSL_DEBUG_MSG(3, ("server has no certificate")); + return -1; + } + + for (cur = list; cur != NULL; cur = cur->next) { + flags = 0; + MBEDTLS_SSL_DEBUG_CRT(3, "candidate certificate chain, certificate", + cur->cert); + + int key_type_matches = 0; +#if defined(MBEDTLS_USE_PSA_CRYPTO) +#if defined(MBEDTLS_SSL_ASYNC_PRIVATE) + key_type_matches = ((ssl->conf->f_async_sign_start != NULL || + ssl->conf->f_async_decrypt_start != NULL || + mbedtls_pk_can_do_ext(cur->key, pk_alg, pk_usage)) && + mbedtls_pk_can_do_ext(&cur->cert->pk, pk_alg, pk_usage)); +#else + key_type_matches = ( + mbedtls_pk_can_do_ext(cur->key, pk_alg, pk_usage)); +#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */ +#else + key_type_matches = mbedtls_pk_can_do(&cur->cert->pk, pk_alg); +#endif /* MBEDTLS_USE_PSA_CRYPTO */ + if (!key_type_matches) { + MBEDTLS_SSL_DEBUG_MSG(3, ("certificate mismatch: key type")); + continue; + } + + /* + * This avoids sending the client a cert it'll reject based on + * keyUsage or other extensions. + * + * It also allows the user to provision different certificates for + * different uses based on keyUsage, eg if they want to avoid signing + * and decrypting with the same RSA key. + */ + if (mbedtls_ssl_check_cert_usage(cur->cert, ciphersuite_info, + MBEDTLS_SSL_IS_SERVER, &flags) != 0) { + MBEDTLS_SSL_DEBUG_MSG(3, ("certificate mismatch: " + "(extended) key usage extension")); + continue; + } + +#if defined(MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED) + if (pk_alg == MBEDTLS_PK_ECDSA && + ssl_check_key_curve(&cur->cert->pk, + ssl->handshake->curves_tls_id) != 0) { + MBEDTLS_SSL_DEBUG_MSG(3, ("certificate mismatch: elliptic curve")); + continue; + } +#endif + + /* If we get there, we got a winner */ + break; + } + + /* Do not update ssl->handshake->key_cert unless there is a match */ + if (cur != NULL) { + ssl->handshake->key_cert = cur; + MBEDTLS_SSL_DEBUG_CRT(3, "selected certificate chain, certificate", + ssl->handshake->key_cert->cert); + return 0; + } + + return -1; +} +#endif /* MBEDTLS_X509_CRT_PARSE_C */ + +/* + * Check if a given ciphersuite is suitable for use with our config/keys/etc + * Sets ciphersuite_info only if the suite matches. + */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_ciphersuite_match(mbedtls_ssl_context *ssl, int suite_id, + const mbedtls_ssl_ciphersuite_t **ciphersuite_info) +{ + const mbedtls_ssl_ciphersuite_t *suite_info; + +#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) + mbedtls_pk_type_t sig_type; +#endif + + suite_info = mbedtls_ssl_ciphersuite_from_id(suite_id); + if (suite_info == NULL) { + MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("trying ciphersuite: %#04x (%s)", + (unsigned int) suite_id, suite_info->name)); + + if (suite_info->min_tls_version > ssl->tls_version || + suite_info->max_tls_version < ssl->tls_version) { + MBEDTLS_SSL_DEBUG_MSG(3, ("ciphersuite mismatch: version")); + return 0; + } + +#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) + if (suite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE && + (ssl->handshake->cli_exts & MBEDTLS_TLS_EXT_ECJPAKE_KKPP_OK) == 0) { + MBEDTLS_SSL_DEBUG_MSG(3, ("ciphersuite mismatch: ecjpake " + "not configured or ext missing")); + return 0; + } +#endif + + +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED) + if (mbedtls_ssl_ciphersuite_uses_ec(suite_info) && + (ssl->handshake->curves_tls_id == NULL || + ssl->handshake->curves_tls_id[0] == 0)) { + MBEDTLS_SSL_DEBUG_MSG(3, ("ciphersuite mismatch: " + "no common elliptic curve")); + return 0; + } +#endif + +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) + /* If the ciphersuite requires a pre-shared key and we don't + * have one, skip it now rather than failing later */ + if (mbedtls_ssl_ciphersuite_uses_psk(suite_info) && + ssl_conf_has_psk_or_cb(ssl->conf) == 0) { + MBEDTLS_SSL_DEBUG_MSG(3, ("ciphersuite mismatch: no pre-shared key")); + return 0; + } +#endif + +#if defined(MBEDTLS_X509_CRT_PARSE_C) + /* + * Final check: if ciphersuite requires us to have a + * certificate/key of a particular type: + * - select the appropriate certificate if we have one, or + * - try the next ciphersuite if we don't + * This must be done last since we modify the key_cert list. + */ + if (ssl_pick_cert(ssl, suite_info) != 0) { + MBEDTLS_SSL_DEBUG_MSG(3, ("ciphersuite mismatch: " + "no suitable certificate")); + return 0; + } +#endif + +#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) + /* If the ciphersuite requires signing, check whether + * a suitable hash algorithm is present. */ + sig_type = mbedtls_ssl_get_ciphersuite_sig_alg(suite_info); + if (sig_type != MBEDTLS_PK_NONE && + mbedtls_ssl_tls12_get_preferred_hash_for_sig_alg( + ssl, mbedtls_ssl_sig_from_pk_alg(sig_type)) == MBEDTLS_SSL_HASH_NONE) { + MBEDTLS_SSL_DEBUG_MSG(3, ("ciphersuite mismatch: no suitable hash algorithm " + "for signature algorithm %u", (unsigned) sig_type)); + return 0; + } + +#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */ + + *ciphersuite_info = suite_info; + return 0; +} + +/* This function doesn't alert on errors that happen early during + ClientHello parsing because they might indicate that the client is + not talking SSL/TLS at all and would not understand our alert. */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_parse_client_hello(mbedtls_ssl_context *ssl) +{ + int ret, got_common_suite; + size_t i, j; + size_t ciph_offset, comp_offset, ext_offset; + size_t msg_len, ciph_len, sess_len, comp_len, ext_len; +#if defined(MBEDTLS_SSL_PROTO_DTLS) + size_t cookie_offset, cookie_len; +#endif + unsigned char *buf, *p, *ext; +#if defined(MBEDTLS_SSL_RENEGOTIATION) + int renegotiation_info_seen = 0; +#endif + int handshake_failure = 0; + const int *ciphersuites; + const mbedtls_ssl_ciphersuite_t *ciphersuite_info; + + /* If there is no signature-algorithm extension present, + * we need to fall back to the default values for allowed + * signature-hash pairs. */ +#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) + int sig_hash_alg_ext_present = 0; +#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */ + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse client hello")); + + int renegotiating; + +#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) +read_record_header: +#endif + /* + * If renegotiating, then the input was read with mbedtls_ssl_read_record(), + * otherwise read it ourselves manually in order to support SSLv2 + * ClientHello, which doesn't use the same record layer format. + * Otherwise in a scenario of TLS 1.3/TLS 1.2 version negotiation, the + * ClientHello has been already fully fetched by the TLS 1.3 code and the + * flag ssl->keep_current_message is raised. + */ + renegotiating = 0; +#if defined(MBEDTLS_SSL_RENEGOTIATION) + renegotiating = (ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE); +#endif + if (!renegotiating && !ssl->keep_current_message) { + if ((ret = mbedtls_ssl_fetch_input(ssl, 5)) != 0) { + /* No alert on a read error. */ + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_fetch_input", ret); + return ret; + } + } + + buf = ssl->in_hdr; + + MBEDTLS_SSL_DEBUG_BUF(4, "record header", buf, mbedtls_ssl_in_hdr_len(ssl)); + + /* + * TLS Client Hello + * + * Record layer: + * 0 . 0 message type + * 1 . 2 protocol version + * 3 . 11 DTLS: epoch + record sequence number + * 3 . 4 message length + */ + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, message type: %d", + buf[0])); + + if (buf[0] != MBEDTLS_SSL_MSG_HANDSHAKE) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client hello message")); + return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, message len.: %d", + MBEDTLS_GET_UINT16_BE(ssl->in_len, 0))); + + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello, protocol version: [%d:%d]", + buf[1], buf[2])); + + /* For DTLS if this is the initial handshake, remember the client sequence + * number to use it in our next message (RFC 6347 4.2.1) */ +#if defined(MBEDTLS_SSL_PROTO_DTLS) + if (ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM +#if defined(MBEDTLS_SSL_RENEGOTIATION) + && ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE +#endif + ) { + /* Epoch should be 0 for initial handshakes */ + if (ssl->in_ctr[0] != 0 || ssl->in_ctr[1] != 0) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client hello message")); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + + memcpy(&ssl->cur_out_ctr[2], ssl->in_ctr + 2, + sizeof(ssl->cur_out_ctr) - 2); + +#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY) + if (mbedtls_ssl_dtls_replay_check(ssl) != 0) { + MBEDTLS_SSL_DEBUG_MSG(1, ("replayed record, discarding")); + ssl->next_record_offset = 0; + ssl->in_left = 0; + goto read_record_header; + } + + /* No MAC to check yet, so we can update right now */ + mbedtls_ssl_dtls_replay_update(ssl); +#endif + } +#endif /* MBEDTLS_SSL_PROTO_DTLS */ + + msg_len = MBEDTLS_GET_UINT16_BE(ssl->in_len, 0); + +#if defined(MBEDTLS_SSL_RENEGOTIATION) + if (ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE) { + /* Set by mbedtls_ssl_read_record() */ + msg_len = ssl->in_hslen; + } else +#endif + { + if (ssl->keep_current_message) { + ssl->keep_current_message = 0; + } else { + if (msg_len > MBEDTLS_SSL_IN_CONTENT_LEN) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client hello message")); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + + if ((ret = mbedtls_ssl_fetch_input(ssl, + mbedtls_ssl_in_hdr_len(ssl) + msg_len)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_fetch_input", ret); + return ret; + } + + /* Done reading this record, get ready for the next one */ +#if defined(MBEDTLS_SSL_PROTO_DTLS) + if (ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM) { + ssl->next_record_offset = msg_len + mbedtls_ssl_in_hdr_len(ssl); + } else +#endif + ssl->in_left = 0; + } + } + + buf = ssl->in_msg; + + MBEDTLS_SSL_DEBUG_BUF(4, "record contents", buf, msg_len); + + ret = ssl->handshake->update_checksum(ssl, buf, msg_len); + if (0 != ret) { + MBEDTLS_SSL_DEBUG_RET(1, ("update_checksum"), ret); + return ret; + } + + /* + * Handshake layer: + * 0 . 0 handshake type + * 1 . 3 handshake length + * 4 . 5 DTLS only: message sequence number + * 6 . 8 DTLS only: fragment offset + * 9 . 11 DTLS only: fragment length + */ + if (msg_len < mbedtls_ssl_hs_hdr_len(ssl)) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client hello message")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello v3, handshake type: %d", buf[0])); + + if (buf[0] != MBEDTLS_SSL_HS_CLIENT_HELLO) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client hello message")); + return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; + } + { + size_t handshake_len = MBEDTLS_GET_UINT24_BE(buf, 1); + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello v3, handshake len.: %u", + (unsigned) handshake_len)); + + /* The record layer has a record size limit of 2^14 - 1 and + * fragmentation is not supported, so buf[1] should be zero. */ + if (buf[1] != 0) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client hello message: %u != 0", + (unsigned) buf[1])); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + /* We don't support fragmentation of ClientHello (yet?) */ + if (msg_len != mbedtls_ssl_hs_hdr_len(ssl) + handshake_len) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client hello message: %u != %u + %u", + (unsigned) msg_len, + (unsigned) mbedtls_ssl_hs_hdr_len(ssl), + (unsigned) handshake_len)); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + } + +#if defined(MBEDTLS_SSL_PROTO_DTLS) + if (ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM) { + /* + * Copy the client's handshake message_seq on initial handshakes, + * check sequence number on renego. + */ +#if defined(MBEDTLS_SSL_RENEGOTIATION) + if (ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS) { + /* This couldn't be done in ssl_prepare_handshake_record() */ + unsigned int cli_msg_seq = (unsigned int) MBEDTLS_GET_UINT16_BE(ssl->in_msg, 4); + if (cli_msg_seq != ssl->handshake->in_msg_seq) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client hello message_seq: " + "%u (expected %u)", cli_msg_seq, + ssl->handshake->in_msg_seq)); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + ssl->handshake->in_msg_seq++; + } else +#endif + { + unsigned int cli_msg_seq = (unsigned int) MBEDTLS_GET_UINT16_BE(ssl->in_msg, 4); + ssl->handshake->out_msg_seq = cli_msg_seq; + ssl->handshake->in_msg_seq = cli_msg_seq + 1; + } + { + /* + * For now we don't support fragmentation, so make sure + * fragment_offset == 0 and fragment_length == length + */ + size_t fragment_offset, fragment_length, length; + fragment_offset = MBEDTLS_GET_UINT24_BE(ssl->in_msg, 6); + fragment_length = MBEDTLS_GET_UINT24_BE(ssl->in_msg, 9); + length = MBEDTLS_GET_UINT24_BE(ssl->in_msg, 1); + MBEDTLS_SSL_DEBUG_MSG( + 4, ("fragment_offset=%u fragment_length=%u length=%u", + (unsigned) fragment_offset, (unsigned) fragment_length, + (unsigned) length)); + if (fragment_offset != 0 || length != fragment_length) { + MBEDTLS_SSL_DEBUG_MSG(1, ("ClientHello fragmentation not supported")); + return MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; + } + } + } +#endif /* MBEDTLS_SSL_PROTO_DTLS */ + + buf += mbedtls_ssl_hs_hdr_len(ssl); + msg_len -= mbedtls_ssl_hs_hdr_len(ssl); + + /* + * ClientHello layout: + * 0 . 1 protocol version + * 2 . 33 random bytes (starting with 4 bytes of Unix time) + * 34 . 34 session id length (1 byte) + * 35 . 34+x session id, where x = session id length from byte 34 + * 35+x . 35+x DTLS only: cookie length (1 byte) + * 36+x . .. DTLS only: cookie + * .. . .. ciphersuite list length (2 bytes) + * .. . .. ciphersuite list + * .. . .. compression alg. list length (1 byte) + * .. . .. compression alg. list + * .. . .. extensions length (2 bytes, optional) + * .. . .. extensions (optional) + */ + + /* + * Minimal length (with everything empty and extensions omitted) is + * 2 + 32 + 1 + 2 + 1 = 38 bytes. Check that first, so that we can + * read at least up to session id length without worrying. + */ + if (msg_len < 38) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client hello message")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + /* + * Check and save the protocol version + */ + MBEDTLS_SSL_DEBUG_BUF(3, "client hello, version", buf, 2); + + ssl->tls_version = (mbedtls_ssl_protocol_version) mbedtls_ssl_read_version(buf, + ssl->conf->transport); + ssl->session_negotiate->tls_version = ssl->tls_version; + ssl->session_negotiate->endpoint = ssl->conf->endpoint; + + if (ssl->tls_version != MBEDTLS_SSL_VERSION_TLS1_2) { + MBEDTLS_SSL_DEBUG_MSG(1, ("server only supports TLS 1.2")); + mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, + MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION); + return MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION; + } + + /* + * Save client random (inc. Unix time) + */ + MBEDTLS_SSL_DEBUG_BUF(3, "client hello, random bytes", buf + 2, 32); + + memcpy(ssl->handshake->randbytes, buf + 2, 32); + + /* + * Check the session ID length and save session ID + */ + sess_len = buf[34]; + + if (sess_len > sizeof(ssl->session_negotiate->id) || + sess_len + 34 + 2 > msg_len) { /* 2 for cipherlist length field */ + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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; + } + + MBEDTLS_SSL_DEBUG_BUF(3, "client hello, session id", buf + 35, sess_len); + + ssl->session_negotiate->id_len = sess_len; + memset(ssl->session_negotiate->id, 0, + sizeof(ssl->session_negotiate->id)); + memcpy(ssl->session_negotiate->id, buf + 35, + ssl->session_negotiate->id_len); + + /* + * Check the cookie length and content + */ +#if defined(MBEDTLS_SSL_PROTO_DTLS) + if (ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM) { + cookie_offset = 35 + sess_len; + cookie_len = buf[cookie_offset]; + + if (cookie_offset + 1 + cookie_len + 2 > msg_len) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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; + } + + MBEDTLS_SSL_DEBUG_BUF(3, "client hello, cookie", + buf + cookie_offset + 1, cookie_len); + +#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) + if (ssl->conf->f_cookie_check != NULL +#if defined(MBEDTLS_SSL_RENEGOTIATION) + && ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE +#endif + ) { + if (ssl->conf->f_cookie_check(ssl->conf->p_cookie, + buf + cookie_offset + 1, cookie_len, + ssl->cli_id, ssl->cli_id_len) != 0) { + MBEDTLS_SSL_DEBUG_MSG(2, ("cookie verification failed")); + ssl->handshake->cookie_verify_result = 1; + } else { + MBEDTLS_SSL_DEBUG_MSG(2, ("cookie verification passed")); + ssl->handshake->cookie_verify_result = 0; + } + } else +#endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */ + { + /* We know we didn't send a cookie, so it should be empty */ + if (cookie_len != 0) { + /* This may be an attacker's probe, so don't send an alert */ + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client hello message")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + MBEDTLS_SSL_DEBUG_MSG(2, ("cookie verification skipped")); + } + + /* + * Check the ciphersuitelist length (will be parsed later) + */ + ciph_offset = cookie_offset + 1 + cookie_len; + } else +#endif /* MBEDTLS_SSL_PROTO_DTLS */ + ciph_offset = 35 + sess_len; + + ciph_len = MBEDTLS_GET_UINT16_BE(buf, ciph_offset); + + if (ciph_len < 2 || + ciph_len + 2 + ciph_offset + 1 > msg_len || /* 1 for comp. alg. len */ + (ciph_len % 2) != 0) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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; + } + + MBEDTLS_SSL_DEBUG_BUF(3, "client hello, ciphersuitelist", + buf + ciph_offset + 2, ciph_len); + + /* + * Check the compression algorithm's length. + * The list contents are ignored because implementing + * MBEDTLS_SSL_COMPRESS_NULL is mandatory and is the only + * option supported by Mbed TLS. + */ + comp_offset = ciph_offset + 2 + ciph_len; + + comp_len = buf[comp_offset]; + + if (comp_len < 1 || + comp_len > 16 || + comp_len + comp_offset + 1 > msg_len) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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; + } + + MBEDTLS_SSL_DEBUG_BUF(3, "client hello, compression", + buf + comp_offset + 1, comp_len); + + /* + * Check the extension length + */ + ext_offset = comp_offset + 1 + comp_len; + if (msg_len > ext_offset) { + if (msg_len < ext_offset + 2) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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; + } + + ext_len = MBEDTLS_GET_UINT16_BE(buf, ext_offset); + + if (msg_len != ext_offset + 2 + ext_len) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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 { + ext_len = 0; + } + + ext = buf + ext_offset + 2; + MBEDTLS_SSL_DEBUG_BUF(3, "client hello extensions", ext, ext_len); + + while (ext_len != 0) { + unsigned int ext_id; + unsigned int ext_size; + if (ext_len < 4) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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; + } + ext_id = MBEDTLS_GET_UINT16_BE(ext, 0); + ext_size = MBEDTLS_GET_UINT16_BE(ext, 2); + + if (ext_size + 4 > ext_len) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client 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) { +#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) + case MBEDTLS_TLS_EXT_SERVERNAME: + MBEDTLS_SSL_DEBUG_MSG(3, ("found ServerName extension")); + ret = mbedtls_ssl_parse_server_name_ext(ssl, ext + 4, + ext + 4 + ext_size); + if (ret != 0) { + return ret; + } + break; +#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */ + + case MBEDTLS_TLS_EXT_RENEGOTIATION_INFO: + MBEDTLS_SSL_DEBUG_MSG(3, ("found renegotiation extension")); +#if defined(MBEDTLS_SSL_RENEGOTIATION) + renegotiation_info_seen = 1; +#endif + + ret = ssl_parse_renegotiation_info(ssl, ext + 4, ext_size); + if (ret != 0) { + return ret; + } + break; + +#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) + case MBEDTLS_TLS_EXT_SIG_ALG: + MBEDTLS_SSL_DEBUG_MSG(3, ("found signature_algorithms extension")); + + ret = mbedtls_ssl_parse_sig_alg_ext(ssl, ext + 4, ext + 4 + ext_size); + if (ret != 0) { + return ret; + } + + sig_hash_alg_ext_present = 1; + break; +#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */ + +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) + case MBEDTLS_TLS_EXT_SUPPORTED_GROUPS: + MBEDTLS_SSL_DEBUG_MSG(3, ("found supported elliptic curves extension")); + + ret = ssl_parse_supported_groups_ext(ssl, ext + 4, ext_size); + if (ret != 0) { + return ret; + } + break; + + case MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS: + MBEDTLS_SSL_DEBUG_MSG(3, ("found supported point formats extension")); + ssl->handshake->cli_exts |= MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT; + + ret = ssl_parse_supported_point_formats(ssl, ext + 4, ext_size); + if (ret != 0) { + return ret; + } + break; +#endif /* MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED || \ + MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED || + 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")); + + ret = ssl_parse_ecjpake_kkpp(ssl, ext + 4, ext_size); + if (ret != 0) { + return ret; + } + break; +#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ + +#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) + case MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH: + MBEDTLS_SSL_DEBUG_MSG(3, ("found max fragment length extension")); + + ret = ssl_parse_max_fragment_length_ext(ssl, ext + 4, ext_size); + if (ret != 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")); + + ret = ssl_parse_cid_ext(ssl, ext + 4, ext_size); + if (ret != 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")); + + ret = ssl_parse_encrypt_then_mac_ext(ssl, ext + 4, ext_size); + if (ret != 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")); + + ret = ssl_parse_extended_ms_ext(ssl, ext + 4, ext_size); + if (ret != 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")); + + ret = ssl_parse_session_ticket_ext(ssl, ext + 4, ext_size); + if (ret != 0) { + return ret; + } + break; +#endif /* MBEDTLS_SSL_SESSION_TICKETS */ + +#if defined(MBEDTLS_SSL_ALPN) + case MBEDTLS_TLS_EXT_ALPN: + MBEDTLS_SSL_DEBUG_MSG(3, ("found alpn extension")); + + ret = mbedtls_ssl_parse_alpn_ext(ssl, ext + 4, + ext + 4 + ext_size); + if (ret != 0) { + return ret; + } + break; +#endif /* MBEDTLS_SSL_SESSION_TICKETS */ + +#if defined(MBEDTLS_SSL_DTLS_SRTP) + case MBEDTLS_TLS_EXT_USE_SRTP: + MBEDTLS_SSL_DEBUG_MSG(3, ("found use_srtp extension")); + + ret = ssl_parse_use_srtp_ext(ssl, ext + 4, ext_size); + if (ret != 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 defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) + + /* + * Try to fall back to default hash SHA1 if the client + * hasn't provided any preferred signature-hash combinations. + */ + if (!sig_hash_alg_ext_present) { + uint16_t *received_sig_algs = ssl->handshake->received_sig_algs; + const uint16_t default_sig_algs[] = { +#if defined(MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED) + MBEDTLS_SSL_TLS12_SIG_AND_HASH_ALG(MBEDTLS_SSL_SIG_ECDSA, + MBEDTLS_SSL_HASH_SHA1), +#endif +#if defined(MBEDTLS_RSA_C) + MBEDTLS_SSL_TLS12_SIG_AND_HASH_ALG(MBEDTLS_SSL_SIG_RSA, + MBEDTLS_SSL_HASH_SHA1), +#endif + MBEDTLS_TLS_SIG_NONE + }; + + MBEDTLS_STATIC_ASSERT(sizeof(default_sig_algs) / sizeof(default_sig_algs[0]) + <= MBEDTLS_RECEIVED_SIG_ALGS_SIZE, + "default_sig_algs is too big"); + + memcpy(received_sig_algs, default_sig_algs, sizeof(default_sig_algs)); + } + +#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */ + + /* + * Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV + */ + for (i = 0, p = buf + ciph_offset + 2; i < ciph_len; i += 2, p += 2) { + if (p[0] == 0 && p[1] == MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO) { + MBEDTLS_SSL_DEBUG_MSG(3, ("received TLS_EMPTY_RENEGOTIATION_INFO ")); +#if defined(MBEDTLS_SSL_RENEGOTIATION) + if (ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS) { + MBEDTLS_SSL_DEBUG_MSG(1, ("received RENEGOTIATION SCSV " + "during renegotiation")); + mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, + MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); + return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; + } +#endif + ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION; + break; + } + } + + /* + * Renegotiation security checks + */ + if (ssl->secure_renegotiation != MBEDTLS_SSL_SECURE_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; + } + + /* + * Server certification selection (after processing TLS extensions) + */ + if (ssl->conf->f_cert_cb && (ret = ssl->conf->f_cert_cb(ssl)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "f_cert_cb", ret); + return ret; + } +#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) + ssl->handshake->sni_name = NULL; + ssl->handshake->sni_name_len = 0; +#endif + + /* + * Search for a matching ciphersuite + * (At the end because we need information from the EC-based extensions + * and certificate from the SNI callback triggered by the SNI extension + * or certificate from server certificate selection callback.) + */ + got_common_suite = 0; + ciphersuites = ssl->conf->ciphersuite_list; + ciphersuite_info = NULL; + + if (ssl->conf->respect_cli_pref == MBEDTLS_SSL_SRV_CIPHERSUITE_ORDER_CLIENT) { + for (j = 0, p = buf + ciph_offset + 2; j < ciph_len; j += 2, p += 2) { + for (i = 0; ciphersuites[i] != 0; i++) { + if (MBEDTLS_GET_UINT16_BE(p, 0) != ciphersuites[i]) { + continue; + } + + got_common_suite = 1; + + if ((ret = ssl_ciphersuite_match(ssl, ciphersuites[i], + &ciphersuite_info)) != 0) { + return ret; + } + + if (ciphersuite_info != NULL) { + goto have_ciphersuite; + } + } + } + } else { + for (i = 0; ciphersuites[i] != 0; i++) { + for (j = 0, p = buf + ciph_offset + 2; j < ciph_len; j += 2, p += 2) { + if (MBEDTLS_GET_UINT16_BE(p, 0) != ciphersuites[i]) { + continue; + } + + got_common_suite = 1; + + if ((ret = ssl_ciphersuite_match(ssl, ciphersuites[i], + &ciphersuite_info)) != 0) { + return ret; + } + + if (ciphersuite_info != NULL) { + goto have_ciphersuite; + } + } + } + } + + if (got_common_suite) { + MBEDTLS_SSL_DEBUG_MSG(1, ("got ciphersuites in common, " + "but none of them usable")); + mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, + MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE); + return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; + } else { + MBEDTLS_SSL_DEBUG_MSG(1, ("got no ciphersuites 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; + } + +have_ciphersuite: + MBEDTLS_SSL_DEBUG_MSG(2, ("selected ciphersuite: %s", ciphersuite_info->name)); + + ssl->session_negotiate->ciphersuite = ciphersuites[i]; + ssl->handshake->ciphersuite_info = ciphersuite_info; + + ssl->state++; + +#if defined(MBEDTLS_SSL_PROTO_DTLS) + if (ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM) { + mbedtls_ssl_recv_flight_completed(ssl); + } +#endif + + /* Debugging-only output for testsuite */ +#if defined(MBEDTLS_DEBUG_C) && \ + defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) + mbedtls_pk_type_t sig_alg = mbedtls_ssl_get_ciphersuite_sig_alg(ciphersuite_info); + if (sig_alg != MBEDTLS_PK_NONE) { + unsigned int sig_hash = mbedtls_ssl_tls12_get_preferred_hash_for_sig_alg( + ssl, mbedtls_ssl_sig_from_pk_alg(sig_alg)); + MBEDTLS_SSL_DEBUG_MSG(3, ("client hello v3, signature_algorithm ext: %u", + sig_hash)); + } else { + MBEDTLS_SSL_DEBUG_MSG(3, ("no hash algorithm for signature algorithm " + "%u - should not happen", (unsigned) sig_alg)); + } +#endif + + MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse client hello")); + + return 0; +} + +#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) +static void ssl_write_cid_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + size_t *olen) +{ + unsigned char *p = buf; + size_t ext_len; + const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN; + + *olen = 0; + + /* Skip writing the extension if we don't want to use it or if + * the client hasn't offered it. */ + if (ssl->handshake->cid_in_use == MBEDTLS_SSL_CID_DISABLED) { + return; + } + + /* ssl->own_cid_len is at most MBEDTLS_SSL_CID_IN_LEN_MAX + * which is at most 255, so the increment cannot overflow. */ + if (end < p || (size_t) (end - p) < (unsigned) (ssl->own_cid_len + 5)) { + MBEDTLS_SSL_DEBUG_MSG(1, ("buffer too small")); + return; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, adding CID extension")); + + /* + * struct { + * opaque cid<0..2^8-1>; + * } ConnectionId; + */ + 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; +} +#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */ + +#if defined(MBEDTLS_SSL_SOME_SUITES_USE_CBC_ETM) +static void ssl_write_encrypt_then_mac_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + size_t *olen) +{ + unsigned char *p = buf; + const mbedtls_ssl_ciphersuite_t *suite = NULL; + + /* + * RFC 7366: "If a server receives an encrypt-then-MAC request extension + * from a client and then selects a stream or Authenticated Encryption + * with Associated Data (AEAD) ciphersuite, it MUST NOT send an + * encrypt-then-MAC response extension back to the client." + */ + suite = mbedtls_ssl_ciphersuite_from_id( + ssl->session_negotiate->ciphersuite); + if (suite == NULL) { + ssl->session_negotiate->encrypt_then_mac = MBEDTLS_SSL_ETM_DISABLED; + } else { + mbedtls_ssl_mode_t ssl_mode = + mbedtls_ssl_get_mode_from_ciphersuite( + ssl->session_negotiate->encrypt_then_mac, + suite); + + if (ssl_mode != MBEDTLS_SSL_MODE_CBC_ETM) { + ssl->session_negotiate->encrypt_then_mac = MBEDTLS_SSL_ETM_DISABLED; + } + } + + if (ssl->session_negotiate->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED) { + *olen = 0; + return; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, adding encrypt then mac extension")); + + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC, p, 0); + p += 2; + + *p++ = 0x00; + *p++ = 0x00; + + *olen = 4; +} +#endif /* MBEDTLS_SSL_SOME_SUITES_USE_CBC_ETM */ + +#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) +static void ssl_write_extended_ms_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + size_t *olen) +{ + unsigned char *p = buf; + + if (ssl->handshake->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED) { + *olen = 0; + return; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, adding extended master secret " + "extension")); + + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET, p, 0); + p += 2; + + *p++ = 0x00; + *p++ = 0x00; + + *olen = 4; +} +#endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */ + +#if defined(MBEDTLS_SSL_SESSION_TICKETS) +static void ssl_write_session_ticket_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + size_t *olen) +{ + unsigned char *p = buf; + + if (ssl->handshake->new_session_ticket == 0) { + *olen = 0; + return; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, adding session ticket extension")); + + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_SESSION_TICKET, p, 0); + p += 2; + + *p++ = 0x00; + *p++ = 0x00; + + *olen = 4; +} +#endif /* MBEDTLS_SSL_SESSION_TICKETS */ + +static void ssl_write_renegotiation_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + size_t *olen) +{ + unsigned char *p = buf; + + if (ssl->secure_renegotiation != MBEDTLS_SSL_SECURE_RENEGOTIATION) { + *olen = 0; + return; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, secure renegotiation extension")); + + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_RENEGOTIATION_INFO, p, 0); + p += 2; + +#if defined(MBEDTLS_SSL_RENEGOTIATION) + if (ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE) { + *p++ = 0x00; + *p++ = (ssl->verify_data_len * 2 + 1) & 0xFF; + *p++ = ssl->verify_data_len * 2 & 0xFF; + + memcpy(p, ssl->peer_verify_data, ssl->verify_data_len); + p += ssl->verify_data_len; + memcpy(p, ssl->own_verify_data, ssl->verify_data_len); + p += ssl->verify_data_len; + } else +#endif /* MBEDTLS_SSL_RENEGOTIATION */ + { + *p++ = 0x00; + *p++ = 0x01; + *p++ = 0x00; + } + + *olen = (size_t) (p - buf); +} + +#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) +static void ssl_write_max_fragment_length_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + size_t *olen) +{ + unsigned char *p = buf; + + if (ssl->session_negotiate->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE) { + *olen = 0; + return; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, max_fragment_length extension")); + + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH, p, 0); + p += 2; + + *p++ = 0x00; + *p++ = 1; + + *p++ = ssl->session_negotiate->mfl_code; + + *olen = 5; +} +#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */ + +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) +static void ssl_write_supported_point_formats_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + size_t *olen) +{ + unsigned char *p = buf; + ((void) ssl); + + if ((ssl->handshake->cli_exts & + MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT) == 0) { + *olen = 0; + return; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, supported_point_formats extension")); + + 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; +} +#endif /* MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED || + MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED || + MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ + +#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) +static void ssl_write_ecjpake_kkpp_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + size_t *olen) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + unsigned char *p = buf; + const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN; + size_t kkpp_len; + + *olen = 0; + + /* Skip costly computation if not needed */ + if (ssl->handshake->ciphersuite_info->key_exchange != + MBEDTLS_KEY_EXCHANGE_ECJPAKE) { + return; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, ecjpake kkpp extension")); + + if (end - p < 4) { + MBEDTLS_SSL_DEBUG_MSG(1, ("buffer too small")); + return; + } + + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_ECJPAKE_KKPP, p, 0); + p += 2; + +#if defined(MBEDTLS_USE_PSA_CRYPTO) + ret = mbedtls_psa_ecjpake_write_round(&ssl->handshake->psa_pake_ctx, + p + 2, (size_t) (end - p - 2), &kkpp_len, + MBEDTLS_ECJPAKE_ROUND_ONE); + if (ret != 0) { + psa_destroy_key(ssl->handshake->psa_pake_password); + psa_pake_abort(&ssl->handshake->psa_pake_ctx); + MBEDTLS_SSL_DEBUG_RET(1, "psa_pake_output", ret); + return; + } +#else + ret = mbedtls_ecjpake_write_round_one(&ssl->handshake->ecjpake_ctx, + p + 2, (size_t) (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; + } +#endif /* MBEDTLS_USE_PSA_CRYPTO */ + + MBEDTLS_PUT_UINT16_BE(kkpp_len, p, 0); + p += 2; + + *olen = kkpp_len + 4; +} +#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ + +#if defined(MBEDTLS_SSL_DTLS_SRTP) && defined(MBEDTLS_SSL_PROTO_DTLS) +static void ssl_write_use_srtp_ext(mbedtls_ssl_context *ssl, + unsigned char *buf, + size_t *olen) +{ + size_t mki_len = 0, ext_len = 0; + uint16_t profile_value = 0; + const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN; + + *olen = 0; + + if ((ssl->conf->transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM) || + (ssl->dtls_srtp_info.chosen_dtls_srtp_profile == MBEDTLS_TLS_SRTP_UNSET)) { + return; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, adding use_srtp extension")); + + if (ssl->conf->dtls_srtp_mki_support == MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED) { + mki_len = ssl->dtls_srtp_info.mki_len; + } + + /* The extension total size is 9 bytes : + * - 2 bytes for the extension tag + * - 2 bytes for the total size + * - 2 bytes for the protection profile length + * - 2 bytes for the protection profile + * - 1 byte for the mki length + * + the actual mki length + * Check we have enough room in the output buffer */ + if ((size_t) (end - buf) < mki_len + 9) { + MBEDTLS_SSL_DEBUG_MSG(1, ("buffer too small")); + return; + } + + /* extension */ + MBEDTLS_PUT_UINT16_BE(MBEDTLS_TLS_EXT_USE_SRTP, buf, 0); + /* + * total length 5 and mki value: only one profile(2 bytes) + * and length(2 bytes) and srtp_mki ) + */ + ext_len = 5 + mki_len; + MBEDTLS_PUT_UINT16_BE(ext_len, buf, 2); + + /* protection profile length: 2 */ + buf[4] = 0x00; + buf[5] = 0x02; + profile_value = mbedtls_ssl_check_srtp_profile_value( + ssl->dtls_srtp_info.chosen_dtls_srtp_profile); + if (profile_value != MBEDTLS_TLS_SRTP_UNSET) { + MBEDTLS_PUT_UINT16_BE(profile_value, buf, 6); + } else { + MBEDTLS_SSL_DEBUG_MSG(1, ("use_srtp extension invalid profile")); + return; + } + + buf[8] = mki_len & 0xFF; + memcpy(&buf[9], ssl->dtls_srtp_info.mki_value, mki_len); + + *olen = 9 + mki_len; +} +#endif /* MBEDTLS_SSL_DTLS_SRTP */ + +#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_write_hello_verify_request(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + unsigned char *p = ssl->out_msg + 4; + unsigned char *cookie_len_byte; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> write hello verify request")); + + /* + * struct { + * ProtocolVersion server_version; + * opaque cookie<0..2^8-1>; + * } HelloVerifyRequest; + */ + + /* The RFC is not clear on this point, but sending the actual negotiated + * version looks like the most interoperable thing to do. */ + mbedtls_ssl_write_version(p, ssl->conf->transport, ssl->tls_version); + MBEDTLS_SSL_DEBUG_BUF(3, "server version", p, 2); + p += 2; + + /* If we get here, f_cookie_check is not null */ + if (ssl->conf->f_cookie_write == NULL) { + MBEDTLS_SSL_DEBUG_MSG(1, ("inconsistent cookie callbacks")); + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + + /* Skip length byte until we know the length */ + cookie_len_byte = p++; + + if ((ret = ssl->conf->f_cookie_write(ssl->conf->p_cookie, + &p, ssl->out_buf + MBEDTLS_SSL_OUT_BUFFER_LEN, + ssl->cli_id, ssl->cli_id_len)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "f_cookie_write", ret); + return ret; + } + + *cookie_len_byte = (unsigned char) (p - (cookie_len_byte + 1)); + + MBEDTLS_SSL_DEBUG_BUF(3, "cookie sent", cookie_len_byte + 1, *cookie_len_byte); + + ssl->out_msglen = (size_t) (p - ssl->out_msg); + ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; + ssl->out_msg[0] = MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST; + + ssl->state = MBEDTLS_SSL_SERVER_HELLO_VERIFY_REQUEST_SENT; + + if ((ret = mbedtls_ssl_write_handshake_msg(ssl)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_write_handshake_msg", ret); + return ret; + } + +#if defined(MBEDTLS_SSL_PROTO_DTLS) + if (ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && + (ret = mbedtls_ssl_flight_transmit(ssl)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_flight_transmit", ret); + return ret; + } +#endif /* MBEDTLS_SSL_PROTO_DTLS */ + + MBEDTLS_SSL_DEBUG_MSG(2, ("<= write hello verify request")); + + return 0; +} +#endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */ + +static void ssl_handle_id_based_session_resumption(mbedtls_ssl_context *ssl) +{ + int ret; + mbedtls_ssl_session session_tmp; + mbedtls_ssl_session * const session = ssl->session_negotiate; + + /* Resume is 0 by default, see ssl_handshake_init(). + * It may be already set to 1 by ssl_parse_session_ticket_ext(). */ + if (ssl->handshake->resume == 1) { + return; + } + if (session->id_len == 0) { + return; + } + if (ssl->conf->f_get_cache == NULL) { + return; + } +#if defined(MBEDTLS_SSL_RENEGOTIATION) + if (ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE) { + return; + } +#endif + + mbedtls_ssl_session_init(&session_tmp); + + ret = ssl->conf->f_get_cache(ssl->conf->p_cache, + session->id, + session->id_len, + &session_tmp); + if (ret != 0) { + goto exit; + } + + if (session->ciphersuite != session_tmp.ciphersuite) { + /* Mismatch between cached and negotiated session */ + goto exit; + } + + /* Move semantics */ + mbedtls_ssl_session_free(session); + *session = session_tmp; + memset(&session_tmp, 0, sizeof(session_tmp)); + + MBEDTLS_SSL_DEBUG_MSG(3, ("session successfully restored from cache")); + ssl->handshake->resume = 1; + +exit: + + mbedtls_ssl_session_free(&session_tmp); +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_write_server_hello(mbedtls_ssl_context *ssl) +{ +#if defined(MBEDTLS_HAVE_TIME) + mbedtls_time_t t; +#endif + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t olen, ext_len = 0, n; + unsigned char *buf, *p; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> write server hello")); + +#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) + if (ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && + ssl->handshake->cookie_verify_result != 0) { + MBEDTLS_SSL_DEBUG_MSG(2, ("client hello was not authenticated")); + MBEDTLS_SSL_DEBUG_MSG(2, ("<= write server hello")); + + return ssl_write_hello_verify_request(ssl); + } +#endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */ + + /* + * 0 . 0 handshake type + * 1 . 3 handshake length + * 4 . 5 protocol version + * 6 . 9 UNIX time() + * 10 . 37 random bytes + */ + buf = ssl->out_msg; + p = buf + 4; + + mbedtls_ssl_write_version(p, ssl->conf->transport, ssl->tls_version); + p += 2; + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, chosen version: [%d:%d]", + buf[4], buf[5])); + +#if defined(MBEDTLS_HAVE_TIME) + t = mbedtls_time(NULL); + MBEDTLS_PUT_UINT32_BE(t, p, 0); + p += 4; + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, current time: %" MBEDTLS_PRINTF_LONGLONG, + (long long) t)); +#else + if ((ret = ssl->conf->f_rng(ssl->conf->p_rng, p, 4)) != 0) { + return ret; + } + + p += 4; +#endif /* MBEDTLS_HAVE_TIME */ + + if ((ret = ssl->conf->f_rng(ssl->conf->p_rng, p, 20)) != 0) { + return ret; + } + p += 20; + +#if defined(MBEDTLS_SSL_PROTO_TLS1_3) + /* + * RFC 8446 + * TLS 1.3 has a downgrade protection mechanism embedded in the server's + * random value. TLS 1.3 servers which negotiate TLS 1.2 or below in + * response to a ClientHello MUST set the last 8 bytes of their Random + * value specially in their ServerHello. + */ + if (mbedtls_ssl_conf_is_tls13_enabled(ssl->conf)) { + static const unsigned char magic_tls12_downgrade_string[] = + { 'D', 'O', 'W', 'N', 'G', 'R', 'D', 1 }; + + MBEDTLS_STATIC_ASSERT( + sizeof(magic_tls12_downgrade_string) == 8, + "magic_tls12_downgrade_string does not have the expected size"); + + memcpy(p, magic_tls12_downgrade_string, + sizeof(magic_tls12_downgrade_string)); + } else +#endif + { + if ((ret = ssl->conf->f_rng(ssl->conf->p_rng, p, 8)) != 0) { + return ret; + } + } + p += 8; + + memcpy(ssl->handshake->randbytes + 32, buf + 6, 32); + + MBEDTLS_SSL_DEBUG_BUF(3, "server hello, random bytes", buf + 6, 32); + + ssl_handle_id_based_session_resumption(ssl); + + if (ssl->handshake->resume == 0) { + /* + * New session, create a new session id, + * unless we're about to issue a session ticket + */ + ssl->state++; + +#if defined(MBEDTLS_HAVE_TIME) + ssl->session_negotiate->start = mbedtls_time(NULL); +#endif + +#if defined(MBEDTLS_SSL_SESSION_TICKETS) + if (ssl->handshake->new_session_ticket != 0) { + ssl->session_negotiate->id_len = n = 0; + memset(ssl->session_negotiate->id, 0, 32); + } else +#endif /* MBEDTLS_SSL_SESSION_TICKETS */ + { + ssl->session_negotiate->id_len = n = 32; + if ((ret = ssl->conf->f_rng(ssl->conf->p_rng, ssl->session_negotiate->id, + n)) != 0) { + return ret; + } + } + } else { + /* + * Resuming a session + */ + n = ssl->session_negotiate->id_len; + 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); + return ret; + } + } + + /* + * 38 . 38 session id length + * 39 . 38+n session id + * 39+n . 40+n chosen ciphersuite + * 41+n . 41+n chosen compression alg. + * 42+n . 43+n extensions length + * 44+n . 43+n+m extensions + */ + *p++ = (unsigned char) ssl->session_negotiate->id_len; + memcpy(p, ssl->session_negotiate->id, ssl->session_negotiate->id_len); + p += ssl->session_negotiate->id_len; + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, session id len.: %" MBEDTLS_PRINTF_SIZET, n)); + MBEDTLS_SSL_DEBUG_BUF(3, "server hello, session id", buf + 39, n); + MBEDTLS_SSL_DEBUG_MSG(3, ("%s session has been resumed", + ssl->handshake->resume ? "a" : "no")); + + MBEDTLS_PUT_UINT16_BE(ssl->session_negotiate->ciphersuite, p, 0); + p += 2; + *p++ = MBEDTLS_BYTE_0(MBEDTLS_SSL_COMPRESS_NULL); + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, chosen ciphersuite: %s", + mbedtls_ssl_get_ciphersuite_name(ssl->session_negotiate->ciphersuite))); + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, compress alg.: 0x%02X", + (unsigned int) MBEDTLS_SSL_COMPRESS_NULL)); + + /* + * First write extensions, then the total length + */ + ssl_write_renegotiation_ext(ssl, p + 2 + ext_len, &olen); + ext_len += olen; + +#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) + ssl_write_max_fragment_length_ext(ssl, p + 2 + ext_len, &olen); + ext_len += olen; +#endif + +#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) + ssl_write_cid_ext(ssl, p + 2 + ext_len, &olen); + ext_len += olen; +#endif + +#if defined(MBEDTLS_SSL_SOME_SUITES_USE_CBC_ETM) + ssl_write_encrypt_then_mac_ext(ssl, p + 2 + ext_len, &olen); + ext_len += olen; +#endif + +#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET) + ssl_write_extended_ms_ext(ssl, p + 2 + ext_len, &olen); + ext_len += olen; +#endif + +#if defined(MBEDTLS_SSL_SESSION_TICKETS) + ssl_write_session_ticket_ext(ssl, p + 2 + ext_len, &olen); + ext_len += olen; +#endif + +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDH_OR_ECDHE_1_2_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) + const mbedtls_ssl_ciphersuite_t *suite = + mbedtls_ssl_ciphersuite_from_id(ssl->session_negotiate->ciphersuite); + if (suite != NULL && mbedtls_ssl_ciphersuite_uses_ec(suite)) { + ssl_write_supported_point_formats_ext(ssl, p + 2 + ext_len, &olen); + ext_len += olen; + } +#endif + +#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) + ssl_write_ecjpake_kkpp_ext(ssl, p + 2 + ext_len, &olen); + ext_len += olen; +#endif + +#if defined(MBEDTLS_SSL_ALPN) + unsigned char *end = buf + MBEDTLS_SSL_OUT_CONTENT_LEN - 4; + if ((ret = mbedtls_ssl_write_alpn_ext(ssl, p + 2 + ext_len, end, &olen)) + != 0) { + return ret; + } + + ext_len += olen; +#endif + +#if defined(MBEDTLS_SSL_DTLS_SRTP) + ssl_write_use_srtp_ext(ssl, p + 2 + ext_len, &olen); + ext_len += olen; +#endif + + MBEDTLS_SSL_DEBUG_MSG(3, ("server hello, total extension length: %" MBEDTLS_PRINTF_SIZET, + ext_len)); + + if (ext_len > 0) { + MBEDTLS_PUT_UINT16_BE(ext_len, p, 0); + p += 2 + ext_len; + } + + ssl->out_msglen = (size_t) (p - buf); + ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; + ssl->out_msg[0] = MBEDTLS_SSL_HS_SERVER_HELLO; + + ret = mbedtls_ssl_write_handshake_msg(ssl); + + MBEDTLS_SSL_DEBUG_MSG(2, ("<= write server hello")); + + return ret; +} + +#if !defined(MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED) +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_write_certificate_request(mbedtls_ssl_context *ssl) +{ + const mbedtls_ssl_ciphersuite_t *ciphersuite_info = + ssl->handshake->ciphersuite_info; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> write certificate request")); + + if (!mbedtls_ssl_ciphersuite_cert_req_allowed(ciphersuite_info)) { + MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip write 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_write_certificate_request(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; + const mbedtls_ssl_ciphersuite_t *ciphersuite_info = + ssl->handshake->ciphersuite_info; + uint16_t dn_size, total_dn_size; /* excluding length bytes */ + size_t ct_len, sa_len; /* including length bytes */ + unsigned char *buf, *p; + const unsigned char * const end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN; + const mbedtls_x509_crt *crt; + int authmode; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> write certificate request")); + + ssl->state++; + +#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) + if (ssl->handshake->sni_authmode != MBEDTLS_SSL_VERIFY_UNSET) { + authmode = ssl->handshake->sni_authmode; + } else +#endif + authmode = ssl->conf->authmode; + + if (!mbedtls_ssl_ciphersuite_cert_req_allowed(ciphersuite_info) || + authmode == MBEDTLS_SSL_VERIFY_NONE) { + MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip write certificate request")); + return 0; + } + + /* + * 0 . 0 handshake type + * 1 . 3 handshake length + * 4 . 4 cert type count + * 5 .. m-1 cert types + * m .. m+1 sig alg length (TLS 1.2 only) + * m+1 .. n-1 SignatureAndHashAlgorithms (TLS 1.2 only) + * n .. n+1 length of all DNs + * n+2 .. n+3 length of DN 1 + * n+4 .. ... Distinguished Name #1 + * ... .. ... length of DN 2, etc. + */ + buf = ssl->out_msg; + p = buf + 4; + + /* + * Supported certificate types + * + * ClientCertificateType certificate_types<1..2^8-1>; + * enum { (255) } ClientCertificateType; + */ + ct_len = 0; + +#if defined(MBEDTLS_RSA_C) + p[1 + ct_len++] = MBEDTLS_SSL_CERT_TYPE_RSA_SIGN; +#endif +#if defined(MBEDTLS_KEY_EXCHANGE_ECDSA_CERT_REQ_ALLOWED_ENABLED) + p[1 + ct_len++] = MBEDTLS_SSL_CERT_TYPE_ECDSA_SIGN; +#endif + + p[0] = (unsigned char) ct_len++; + p += ct_len; + + sa_len = 0; + + /* + * Add signature_algorithms for verify (TLS 1.2) + * + * SignatureAndHashAlgorithm supported_signature_algorithms<2..2^16-2>; + * + * struct { + * HashAlgorithm hash; + * SignatureAlgorithm signature; + * } SignatureAndHashAlgorithm; + * + * enum { (255) } HashAlgorithm; + * enum { (255) } SignatureAlgorithm; + */ + const uint16_t *sig_alg = mbedtls_ssl_get_sig_algs(ssl); + if (sig_alg == NULL) { + return MBEDTLS_ERR_SSL_BAD_CONFIG; + } + + for (; *sig_alg != MBEDTLS_TLS_SIG_NONE; sig_alg++) { + unsigned char hash = MBEDTLS_BYTE_1(*sig_alg); + + if (mbedtls_ssl_set_calc_verify_md(ssl, hash)) { + continue; + } + if (!mbedtls_ssl_sig_alg_is_supported(ssl, *sig_alg)) { + continue; + } + + /* Write elements at offsets starting from 1 (offset 0 is for the + * length). Thus the offset of each element is the length of the + * partial list including that element. */ + sa_len += 2; + MBEDTLS_PUT_UINT16_BE(*sig_alg, p, sa_len); + + } + + /* Fill in list length. */ + MBEDTLS_PUT_UINT16_BE(sa_len, p, 0); + sa_len += 2; + p += sa_len; + + /* + * DistinguishedName certificate_authorities<0..2^16-1>; + * opaque DistinguishedName<1..2^16-1>; + */ + p += 2; + + total_dn_size = 0; + + if (ssl->conf->cert_req_ca_list == MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED) { + /* NOTE: If trusted certificates are provisioned + * via a CA callback (configured through + * `mbedtls_ssl_conf_ca_cb()`, then the + * CertificateRequest is currently left empty. */ + +#if defined(MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED) +#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) + if (ssl->handshake->dn_hints != NULL) { + crt = ssl->handshake->dn_hints; + } else +#endif + if (ssl->conf->dn_hints != NULL) { + crt = ssl->conf->dn_hints; + } else +#endif +#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) + if (ssl->handshake->sni_ca_chain != NULL) { + crt = ssl->handshake->sni_ca_chain; + } else +#endif + crt = ssl->conf->ca_chain; + + while (crt != NULL && crt->version != 0) { + /* It follows from RFC 5280 A.1 that this length + * can be represented in at most 11 bits. */ + dn_size = (uint16_t) crt->subject_raw.len; + + if (end < p || (size_t) (end - p) < 2 + (size_t) dn_size) { + MBEDTLS_SSL_DEBUG_MSG(1, ("skipping CAs: buffer too short")); + break; + } + + MBEDTLS_PUT_UINT16_BE(dn_size, p, 0); + p += 2; + memcpy(p, crt->subject_raw.p, dn_size); + p += dn_size; + + MBEDTLS_SSL_DEBUG_BUF(3, "requested DN", p - dn_size, dn_size); + + total_dn_size += (unsigned short) (2 + dn_size); + crt = crt->next; + } + } + + ssl->out_msglen = (size_t) (p - buf); + ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; + ssl->out_msg[0] = MBEDTLS_SSL_HS_CERTIFICATE_REQUEST; + MBEDTLS_PUT_UINT16_BE(total_dn_size, ssl->out_msg, 4 + ct_len + sa_len); + + ret = mbedtls_ssl_write_handshake_msg(ssl); + + MBEDTLS_SSL_DEBUG_MSG(2, ("<= write certificate request")); + + return ret; +} +#endif /* MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED */ + +#if (defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)) +#if defined(MBEDTLS_USE_PSA_CRYPTO) +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_get_ecdh_params_from_cert(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; + mbedtls_pk_context *pk; + mbedtls_pk_type_t pk_type; + psa_key_attributes_t key_attributes = PSA_KEY_ATTRIBUTES_INIT; + unsigned char buf[PSA_KEY_EXPORT_ECC_KEY_PAIR_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)]; + size_t key_len; +#if !defined(MBEDTLS_PK_USE_PSA_EC_DATA) + uint16_t tls_id = 0; + psa_key_type_t key_type = PSA_KEY_TYPE_NONE; + mbedtls_ecp_group_id grp_id; + mbedtls_ecp_keypair *key; +#endif /* !MBEDTLS_PK_USE_PSA_EC_DATA */ + + pk = mbedtls_ssl_own_key(ssl); + + if (pk == NULL) { + return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; + } + + pk_type = mbedtls_pk_get_type(pk); + + switch (pk_type) { + case MBEDTLS_PK_OPAQUE: +#if defined(MBEDTLS_PK_USE_PSA_EC_DATA) + case MBEDTLS_PK_ECKEY: + case MBEDTLS_PK_ECKEY_DH: + case MBEDTLS_PK_ECDSA: +#endif /* MBEDTLS_PK_USE_PSA_EC_DATA */ + if (!mbedtls_pk_can_do(pk, MBEDTLS_PK_ECKEY)) { + return MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH; + } + + /* Get the attributes of the key previously parsed by PK module in + * order to extract its type and length (in bits). */ + status = psa_get_key_attributes(pk->priv_id, &key_attributes); + if (status != PSA_SUCCESS) { + ret = PSA_TO_MBEDTLS_ERR(status); + goto exit; + } + ssl->handshake->xxdh_psa_type = psa_get_key_type(&key_attributes); + ssl->handshake->xxdh_psa_bits = psa_get_key_bits(&key_attributes); + + if (pk_type == MBEDTLS_PK_OPAQUE) { + /* Opaque key is created by the user (externally from Mbed TLS) + * so we assume it already has the right algorithm and flags + * set. Just copy its ID as reference. */ + ssl->handshake->xxdh_psa_privkey = pk->priv_id; + ssl->handshake->xxdh_psa_privkey_is_external = 1; + } else { + /* PK_ECKEY[_DH] and PK_ECDSA instead as parsed from the PK + * module and only have ECDSA capabilities. Since we need + * them for ECDH later, we export and then re-import them with + * proper flags and algorithm. Of course We also set key's type + * and bits that we just got above. */ + 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, + PSA_KEY_TYPE_ECC_KEY_PAIR(ssl->handshake->xxdh_psa_type)); + psa_set_key_bits(&key_attributes, ssl->handshake->xxdh_psa_bits); + + status = psa_export_key(pk->priv_id, buf, sizeof(buf), &key_len); + if (status != PSA_SUCCESS) { + ret = PSA_TO_MBEDTLS_ERR(status); + goto exit; + } + status = psa_import_key(&key_attributes, buf, key_len, + &ssl->handshake->xxdh_psa_privkey); + if (status != PSA_SUCCESS) { + ret = PSA_TO_MBEDTLS_ERR(status); + goto exit; + } + + /* Set this key as owned by the TLS library: it will be its duty + * to clear it exit. */ + ssl->handshake->xxdh_psa_privkey_is_external = 0; + } + + ret = 0; + break; +#if !defined(MBEDTLS_PK_USE_PSA_EC_DATA) + case MBEDTLS_PK_ECKEY: + case MBEDTLS_PK_ECKEY_DH: + case MBEDTLS_PK_ECDSA: + key = mbedtls_pk_ec_rw(*pk); + grp_id = mbedtls_pk_get_ec_group_id(pk); + if (grp_id == MBEDTLS_ECP_DP_NONE) { + return MBEDTLS_ERR_ECP_BAD_INPUT_DATA; + } + tls_id = mbedtls_ssl_get_tls_id_from_ecp_group_id(grp_id); + if (tls_id == 0) { + /* This elliptic curve is not supported */ + return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; + } + + /* If the above conversion to TLS ID was fine, then also this one will + be, so there is no need to check the return value here */ + mbedtls_ssl_get_psa_curve_info_from_tls_id(tls_id, &key_type, + &ssl->handshake->xxdh_psa_bits); + + ssl->handshake->xxdh_psa_type = key_type; + + 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, + PSA_KEY_TYPE_ECC_KEY_PAIR(ssl->handshake->xxdh_psa_type)); + psa_set_key_bits(&key_attributes, ssl->handshake->xxdh_psa_bits); + + ret = mbedtls_ecp_write_key_ext(key, &key_len, buf, sizeof(buf)); + if (ret != 0) { + mbedtls_platform_zeroize(buf, sizeof(buf)); + break; + } + + status = psa_import_key(&key_attributes, buf, key_len, + &ssl->handshake->xxdh_psa_privkey); + if (status != PSA_SUCCESS) { + ret = PSA_TO_MBEDTLS_ERR(status); + mbedtls_platform_zeroize(buf, sizeof(buf)); + break; + } + + mbedtls_platform_zeroize(buf, sizeof(buf)); + ret = 0; + break; +#endif /* !MBEDTLS_PK_USE_PSA_EC_DATA */ + default: + ret = MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH; + } + +exit: + psa_reset_key_attributes(&key_attributes); + mbedtls_platform_zeroize(buf, sizeof(buf)); + + return ret; +} +#else /* MBEDTLS_USE_PSA_CRYPTO */ +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_pk_context *private_key = mbedtls_ssl_own_key(ssl); + if (private_key == NULL) { + MBEDTLS_SSL_DEBUG_MSG(1, ("got no server private key")); + return MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED; + } + + if (!mbedtls_pk_can_do(private_key, MBEDTLS_PK_ECKEY)) { + MBEDTLS_SSL_DEBUG_MSG(1, ("server key not ECDH capable")); + return MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH; + } + + if ((ret = mbedtls_ecdh_get_params(&ssl->handshake->ecdh_ctx, + mbedtls_pk_ec_ro(*mbedtls_ssl_own_key(ssl)), + MBEDTLS_ECDH_OURS)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, ("mbedtls_ecdh_get_params"), ret); + return ret; + } + + return 0; +} +#endif /* MBEDTLS_USE_PSA_CRYPTO */ +#endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || + MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ + +#if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) && \ + defined(MBEDTLS_SSL_ASYNC_PRIVATE) +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_resume_server_key_exchange(mbedtls_ssl_context *ssl, + size_t *signature_len) +{ + /* Append the signature to ssl->out_msg, leaving 2 bytes for the + * signature length which will be added in ssl_write_server_key_exchange + * after the call to ssl_prepare_server_key_exchange. + * ssl_write_server_key_exchange also takes care of incrementing + * ssl->out_msglen. */ + unsigned char *sig_start = ssl->out_msg + ssl->out_msglen + 2; + size_t sig_max_len = (ssl->out_buf + MBEDTLS_SSL_OUT_CONTENT_LEN + - sig_start); + int ret = ssl->conf->f_async_resume(ssl, + sig_start, signature_len, sig_max_len); + if (ret != MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS) { + ssl->handshake->async_in_progress = 0; + mbedtls_ssl_set_async_operation_data(ssl, NULL); + } + MBEDTLS_SSL_DEBUG_RET(2, "ssl_resume_server_key_exchange", ret); + return ret; +} +#endif /* defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) && + defined(MBEDTLS_SSL_ASYNC_PRIVATE) */ + +/* Prepare the ServerKeyExchange message, up to and including + * calculating the signature if any, but excluding formatting the + * signature and sending the message. */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_prepare_server_key_exchange(mbedtls_ssl_context *ssl, + size_t *signature_len) +{ + const mbedtls_ssl_ciphersuite_t *ciphersuite_info = + ssl->handshake->ciphersuite_info; + +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PFS_ENABLED) +#if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) + unsigned char *dig_signed = NULL; +#endif /* MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED */ +#endif /* MBEDTLS_KEY_EXCHANGE_SOME_PFS_ENABLED */ + + (void) ciphersuite_info; /* unused in some configurations */ +#if !defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) + (void) signature_len; +#endif /* MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED */ + +#if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) +#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH) + size_t out_buf_len = ssl->out_buf_len - (size_t) (ssl->out_msg - ssl->out_buf); +#else + size_t out_buf_len = MBEDTLS_SSL_OUT_BUFFER_LEN - (size_t) (ssl->out_msg - ssl->out_buf); +#endif +#endif + + ssl->out_msglen = 4; /* header (type:1, length:3) to be written later */ + + /* + * + * Part 1: Provide key exchange parameters for chosen ciphersuite. + * + */ + + /* + * - ECJPAKE key exchanges + */ +#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) + if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE) { + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; +#if defined(MBEDTLS_USE_PSA_CRYPTO) + unsigned char *out_p = ssl->out_msg + ssl->out_msglen; + unsigned char *end_p = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN - + ssl->out_msglen; + size_t output_offset = 0; + size_t output_len = 0; + + /* + * The first 3 bytes are: + * [0] MBEDTLS_ECP_TLS_NAMED_CURVE + * [1, 2] elliptic curve's TLS ID + * + * However since we only support secp256r1 for now, we hardcode its + * TLS ID here + */ + uint16_t tls_id = mbedtls_ssl_get_tls_id_from_ecp_group_id( + MBEDTLS_ECP_DP_SECP256R1); + if (tls_id == 0) { + return MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; + } + *out_p = MBEDTLS_ECP_TLS_NAMED_CURVE; + MBEDTLS_PUT_UINT16_BE(tls_id, out_p, 1); + output_offset += 3; + + ret = mbedtls_psa_ecjpake_write_round(&ssl->handshake->psa_pake_ctx, + out_p + output_offset, + end_p - out_p - output_offset, &output_len, + MBEDTLS_ECJPAKE_ROUND_TWO); + if (ret != 0) { + psa_destroy_key(ssl->handshake->psa_pake_password); + psa_pake_abort(&ssl->handshake->psa_pake_ctx); + MBEDTLS_SSL_DEBUG_RET(1, "psa_pake_output", ret); + return ret; + } + + output_offset += output_len; + ssl->out_msglen += output_offset; +#else + size_t len = 0; + + ret = mbedtls_ecjpake_write_round_two( + &ssl->handshake->ecjpake_ctx, + ssl->out_msg + ssl->out_msglen, + MBEDTLS_SSL_OUT_CONTENT_LEN - ssl->out_msglen, &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; + } + + ssl->out_msglen += len; +#endif /* MBEDTLS_USE_PSA_CRYPTO */ + } +#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ + + /* + * For (EC)DHE key exchanges with PSK, parameters are prefixed by support + * identity hint (RFC 4279, Sec. 3). Until someone needs this feature, + * we use empty support identity hints here. + **/ +#if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) + if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK) { + ssl->out_msg[ssl->out_msglen++] = 0x00; + ssl->out_msg[ssl->out_msglen++] = 0x00; + } +#endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED || + MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */ + + /* + * - DHE key exchanges + */ +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_DHE_ENABLED) + if (mbedtls_ssl_ciphersuite_uses_dhe(ciphersuite_info)) { + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t len = 0; + + if (ssl->conf->dhm_P.p == NULL || ssl->conf->dhm_G.p == NULL) { + MBEDTLS_SSL_DEBUG_MSG(1, ("no DH parameters set")); + return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; + } + + /* + * 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_set_group(&ssl->handshake->dhm_ctx, + &ssl->conf->dhm_P, + &ssl->conf->dhm_G)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_dhm_set_group", ret); + return ret; + } + + if ((ret = mbedtls_dhm_make_params( + &ssl->handshake->dhm_ctx, + (int) mbedtls_dhm_get_len(&ssl->handshake->dhm_ctx), + ssl->out_msg + ssl->out_msglen, &len, + ssl->conf->f_rng, ssl->conf->p_rng)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_dhm_make_params", ret); + return ret; + } + +#if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) + dig_signed = ssl->out_msg + ssl->out_msglen; +#endif + + ssl->out_msglen += len; + + MBEDTLS_SSL_DEBUG_MPI(3, "DHM: X ", &ssl->handshake->dhm_ctx.X); + 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: GX", &ssl->handshake->dhm_ctx.GX); + } +#endif /* MBEDTLS_KEY_EXCHANGE_SOME_DHE_ENABLED */ + + /* + * - ECDHE key exchanges + */ +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDHE_ENABLED) + if (mbedtls_ssl_ciphersuite_uses_ecdhe(ciphersuite_info)) { + /* + * Ephemeral ECDH parameters: + * + * struct { + * ECParameters curve_params; + * ECPoint public; + * } ServerECDHParams; + */ + uint16_t *curr_tls_id = ssl->handshake->curves_tls_id; + const uint16_t *group_list = mbedtls_ssl_get_groups(ssl); + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t len = 0; + + /* Match our preference list against the offered curves */ + if ((group_list == NULL) || (curr_tls_id == NULL)) { + return MBEDTLS_ERR_SSL_BAD_CONFIG; + } + for (; *group_list != 0; group_list++) { + for (curr_tls_id = ssl->handshake->curves_tls_id; + *curr_tls_id != 0; curr_tls_id++) { + if (*curr_tls_id == *group_list) { + goto curve_matching_done; + } + } + } + +curve_matching_done: + if (*curr_tls_id == 0) { + MBEDTLS_SSL_DEBUG_MSG(1, ("no matching curve for ECDHE")); + return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; + } + + MBEDTLS_SSL_DEBUG_MSG(2, ("ECDHE curve: %s", + mbedtls_ssl_get_curve_name_from_tls_id(*curr_tls_id))); + +#if defined(MBEDTLS_USE_PSA_CRYPTO) + psa_status_t status = PSA_ERROR_GENERIC_ERROR; + psa_key_attributes_t key_attributes; + mbedtls_ssl_handshake_params *handshake = ssl->handshake; + uint8_t *p = ssl->out_msg + ssl->out_msglen; + const size_t header_size = 4; // curve_type(1), namedcurve(2), + // data length(1) + const size_t data_length_size = 1; + psa_key_type_t key_type = PSA_KEY_TYPE_NONE; + size_t ec_bits = 0; + + MBEDTLS_SSL_DEBUG_MSG(1, ("Perform PSA-based ECDH computation.")); + + /* Convert EC's TLS ID to PSA key type. */ + if (mbedtls_ssl_get_psa_curve_info_from_tls_id(*curr_tls_id, + &key_type, + &ec_bits) == PSA_ERROR_NOT_SUPPORTED) { + MBEDTLS_SSL_DEBUG_MSG(1, ("Invalid ecc group parse.")); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + handshake->xxdh_psa_type = key_type; + handshake->xxdh_psa_bits = ec_bits; + + 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->xxdh_psa_type); + psa_set_key_bits(&key_attributes, handshake->xxdh_psa_bits); + + /* + * ECParameters curve_params + * + * First byte is curve_type, always named_curve + */ + *p++ = MBEDTLS_ECP_TLS_NAMED_CURVE; + + /* + * Next two bytes are the namedcurve value + */ + MBEDTLS_PUT_UINT16_BE(*curr_tls_id, p, 0); + p += 2; + + /* Generate ECDH private key. */ + status = psa_generate_key(&key_attributes, + &handshake->xxdh_psa_privkey); + if (status != PSA_SUCCESS) { + ret = PSA_TO_MBEDTLS_ERR(status); + MBEDTLS_SSL_DEBUG_RET(1, "psa_generate_key", ret); + return ret; + } + + /* + * ECPoint public + * + * First byte is data length. + * It will be filled later. p holds now the data length location. + */ + + /* Export the public part of the ECDH private key from PSA. + * Make one byte space for the length. + */ + unsigned char *own_pubkey = p + data_length_size; + + size_t own_pubkey_max_len = (size_t) (MBEDTLS_SSL_OUT_CONTENT_LEN + - (own_pubkey - ssl->out_msg)); + + status = psa_export_public_key(handshake->xxdh_psa_privkey, + own_pubkey, own_pubkey_max_len, + &len); + if (status != PSA_SUCCESS) { + ret = PSA_TO_MBEDTLS_ERR(status); + MBEDTLS_SSL_DEBUG_RET(1, "psa_export_public_key", ret); + (void) psa_destroy_key(handshake->xxdh_psa_privkey); + handshake->xxdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT; + return ret; + } + + /* Store the length of the exported public key. */ + *p = (uint8_t) len; + + /* Determine full message length. */ + len += header_size; +#else + mbedtls_ecp_group_id curr_grp_id = + mbedtls_ssl_get_ecp_group_id_from_tls_id(*curr_tls_id); + + if ((ret = mbedtls_ecdh_setup(&ssl->handshake->ecdh_ctx, + curr_grp_id)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecp_group_load", ret); + return ret; + } + + if ((ret = mbedtls_ecdh_make_params( + &ssl->handshake->ecdh_ctx, &len, + ssl->out_msg + ssl->out_msglen, + MBEDTLS_SSL_OUT_CONTENT_LEN - ssl->out_msglen, + ssl->conf->f_rng, ssl->conf->p_rng)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecdh_make_params", ret); + return ret; + } + + MBEDTLS_SSL_DEBUG_ECDH(3, &ssl->handshake->ecdh_ctx, + MBEDTLS_DEBUG_ECDH_Q); +#endif /* MBEDTLS_USE_PSA_CRYPTO */ + +#if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) + dig_signed = ssl->out_msg + ssl->out_msglen; +#endif + + ssl->out_msglen += len; + } +#endif /* MBEDTLS_KEY_EXCHANGE_SOME_ECDHE_ENABLED */ + + /* + * + * Part 2: For key exchanges involving the server signing the + * exchange parameters, compute and add the signature here. + * + */ +#if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) + if (mbedtls_ssl_ciphersuite_uses_server_signature(ciphersuite_info)) { + if (dig_signed == NULL) { + MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + + size_t dig_signed_len = (size_t) (ssl->out_msg + ssl->out_msglen - dig_signed); + size_t hashlen = 0; + unsigned char hash[MBEDTLS_MD_MAX_SIZE]; + + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + + /* + * 2.1: Choose hash algorithm: + * For TLS 1.2, obey signature-hash-algorithm extension + * to choose appropriate hash. + */ + + mbedtls_pk_type_t sig_alg = + mbedtls_ssl_get_ciphersuite_sig_pk_alg(ciphersuite_info); + + unsigned char sig_hash = + (unsigned char) mbedtls_ssl_tls12_get_preferred_hash_for_sig_alg( + ssl, mbedtls_ssl_sig_from_pk_alg(sig_alg)); + + mbedtls_md_type_t md_alg = mbedtls_ssl_md_alg_from_hash(sig_hash); + + /* For TLS 1.2, obey signature-hash-algorithm extension + * (RFC 5246, Sec. 7.4.1.4.1). */ + if (sig_alg == MBEDTLS_PK_NONE || md_alg == MBEDTLS_MD_NONE) { + MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); + /* (... because we choose a cipher suite + * only if there is a matching hash.) */ + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + + MBEDTLS_SSL_DEBUG_MSG(3, ("pick hash algorithm %u for signing", (unsigned) md_alg)); + + /* + * 2.2: Compute the hash to be signed + */ + if (md_alg != MBEDTLS_MD_NONE) { + ret = mbedtls_ssl_get_key_exchange_md_tls1_2(ssl, hash, &hashlen, + dig_signed, + dig_signed_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); + + /* + * 2.3: Compute and add the signature + */ + /* + * We need to specify signature and hash algorithm explicitly through + * a prefix to the signature. + * + * struct { + * HashAlgorithm hash; + * SignatureAlgorithm signature; + * } SignatureAndHashAlgorithm; + * + * struct { + * SignatureAndHashAlgorithm algorithm; + * opaque signature<0..2^16-1>; + * } DigitallySigned; + * + */ + + ssl->out_msg[ssl->out_msglen++] = mbedtls_ssl_hash_from_md_alg(md_alg); + ssl->out_msg[ssl->out_msglen++] = mbedtls_ssl_sig_from_pk_alg(sig_alg); + +#if defined(MBEDTLS_SSL_ASYNC_PRIVATE) + if (ssl->conf->f_async_sign_start != NULL) { + ret = ssl->conf->f_async_sign_start(ssl, + mbedtls_ssl_own_cert(ssl), + md_alg, hash, hashlen); + switch (ret) { + case MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH: + /* act as if f_async_sign was null */ + break; + case 0: + ssl->handshake->async_in_progress = 1; + return ssl_resume_server_key_exchange(ssl, signature_len); + case MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS: + ssl->handshake->async_in_progress = 1; + return MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS; + default: + MBEDTLS_SSL_DEBUG_RET(1, "f_async_sign_start", ret); + return ret; + } + } +#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */ + + if (mbedtls_ssl_own_key(ssl) == NULL) { + MBEDTLS_SSL_DEBUG_MSG(1, ("got no private key")); + return MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED; + } + + /* Append the signature to ssl->out_msg, leaving 2 bytes for the + * signature length which will be added in ssl_write_server_key_exchange + * after the call to ssl_prepare_server_key_exchange. + * ssl_write_server_key_exchange also takes care of incrementing + * ssl->out_msglen. */ + if ((ret = mbedtls_pk_sign(mbedtls_ssl_own_key(ssl), + md_alg, hash, hashlen, + ssl->out_msg + ssl->out_msglen + 2, + out_buf_len - ssl->out_msglen - 2, + signature_len, + ssl->conf->f_rng, + ssl->conf->p_rng)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_pk_sign", ret); + return ret; + } + } +#endif /* MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED */ + + return 0; +} + +/* Prepare the ServerKeyExchange message and send it. For ciphersuites + * that do not include a ServerKeyExchange message, do nothing. Either + * way, if successful, move on to the next step in the SSL state + * machine. */ +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_write_server_key_exchange(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t signature_len = 0; +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_NON_PFS_ENABLED) + const mbedtls_ssl_ciphersuite_t *ciphersuite_info = + ssl->handshake->ciphersuite_info; +#endif /* MBEDTLS_KEY_EXCHANGE_SOME_NON_PFS_ENABLED */ + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> write server key exchange")); + +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_NON_PFS_ENABLED) + /* Extract static ECDH parameters and abort if ServerKeyExchange + * is not needed. */ + if (mbedtls_ssl_ciphersuite_no_pfs(ciphersuite_info)) { + /* For suites involving ECDH, extract DH parameters + * from certificate at this point. */ +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_ECDH_ENABLED) + if (mbedtls_ssl_ciphersuite_uses_ecdh(ciphersuite_info)) { + ret = ssl_get_ecdh_params_from_cert(ssl); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "ssl_get_ecdh_params_from_cert", ret); + return ret; + } + } +#endif /* MBEDTLS_KEY_EXCHANGE_SOME_ECDH_ENABLED */ + + /* Key exchanges not involving ephemeral keys don't use + * ServerKeyExchange, so end here. */ + MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip write server key exchange")); + ssl->state++; + return 0; + } +#endif /* MBEDTLS_KEY_EXCHANGE_SOME_NON_PFS_ENABLED */ + +#if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) && \ + defined(MBEDTLS_SSL_ASYNC_PRIVATE) + /* If we have already prepared the message and there is an ongoing + * signature operation, resume signing. */ + if (ssl->handshake->async_in_progress != 0) { + MBEDTLS_SSL_DEBUG_MSG(2, ("resuming signature operation")); + ret = ssl_resume_server_key_exchange(ssl, &signature_len); + } else +#endif /* defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) && + defined(MBEDTLS_SSL_ASYNC_PRIVATE) */ + { + /* ServerKeyExchange is needed. Prepare the message. */ + ret = ssl_prepare_server_key_exchange(ssl, &signature_len); + } + + if (ret != 0) { + /* If we're starting to write a new message, set ssl->out_msglen + * to 0. But if we're resuming after an asynchronous message, + * out_msglen is the amount of data written so far and mst be + * preserved. */ + if (ret == MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS) { + MBEDTLS_SSL_DEBUG_MSG(2, ("<= write server key exchange (pending)")); + } else { + ssl->out_msglen = 0; + } + return ret; + } + + /* If there is a signature, write its length. + * ssl_prepare_server_key_exchange already wrote the signature + * itself at its proper place in the output buffer. */ +#if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED) + if (signature_len != 0) { + ssl->out_msg[ssl->out_msglen++] = MBEDTLS_BYTE_1(signature_len); + ssl->out_msg[ssl->out_msglen++] = MBEDTLS_BYTE_0(signature_len); + + MBEDTLS_SSL_DEBUG_BUF(3, "my signature", + ssl->out_msg + ssl->out_msglen, + signature_len); + + /* Skip over the already-written signature */ + ssl->out_msglen += signature_len; + } +#endif /* MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED */ + + /* Add header and send. */ + ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; + ssl->out_msg[0] = MBEDTLS_SSL_HS_SERVER_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 server key exchange")); + return 0; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_write_server_hello_done(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> write server hello done")); + + ssl->out_msglen = 4; + ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; + ssl->out_msg[0] = MBEDTLS_SSL_HS_SERVER_HELLO_DONE; + + ssl->state++; + +#if defined(MBEDTLS_SSL_PROTO_DTLS) + if (ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM) { + mbedtls_ssl_send_flight_completed(ssl); + } +#endif + + if ((ret = mbedtls_ssl_write_handshake_msg(ssl)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_write_handshake_msg", ret); + return ret; + } + +#if defined(MBEDTLS_SSL_PROTO_DTLS) + if (ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM && + (ret = mbedtls_ssl_flight_transmit(ssl)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_flight_transmit", ret); + return ret; + } +#endif /* MBEDTLS_SSL_PROTO_DTLS */ + + MBEDTLS_SSL_DEBUG_MSG(2, ("<= write server hello done")); + + 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_client_dh_public(mbedtls_ssl_context *ssl, unsigned char **p, + const unsigned char *end) +{ + int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; + size_t n; + + /* + * Receive G^Y mod P, premaster = (G^Y)^X mod P + */ + if (*p + 2 > end) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client key exchange message")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + n = MBEDTLS_GET_UINT16_BE(*p, 0); + *p += 2; + + if (*p + n > end) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client key exchange message")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + if ((ret = mbedtls_dhm_read_public(&ssl->handshake->dhm_ctx, *p, n)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_dhm_read_public", ret); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + *p += n; + + 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_RSA_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) + +#if defined(MBEDTLS_SSL_ASYNC_PRIVATE) +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_resume_decrypt_pms(mbedtls_ssl_context *ssl, + unsigned char *peer_pms, + size_t *peer_pmslen, + size_t peer_pmssize) +{ + int ret = ssl->conf->f_async_resume(ssl, + peer_pms, peer_pmslen, peer_pmssize); + if (ret != MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS) { + ssl->handshake->async_in_progress = 0; + mbedtls_ssl_set_async_operation_data(ssl, NULL); + } + MBEDTLS_SSL_DEBUG_RET(2, "ssl_decrypt_encrypted_pms", ret); + return ret; +} +#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */ + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_decrypt_encrypted_pms(mbedtls_ssl_context *ssl, + const unsigned char *p, + const unsigned char *end, + unsigned char *peer_pms, + size_t *peer_pmslen, + size_t peer_pmssize) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + + mbedtls_x509_crt *own_cert = mbedtls_ssl_own_cert(ssl); + if (own_cert == NULL) { + MBEDTLS_SSL_DEBUG_MSG(1, ("got no local certificate")); + return MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE; + } + mbedtls_pk_context *public_key = &own_cert->pk; + mbedtls_pk_context *private_key = mbedtls_ssl_own_key(ssl); + size_t len = mbedtls_pk_get_len(public_key); + +#if defined(MBEDTLS_SSL_ASYNC_PRIVATE) + /* If we have already started decoding the message and there is an ongoing + * decryption operation, resume signing. */ + if (ssl->handshake->async_in_progress != 0) { + MBEDTLS_SSL_DEBUG_MSG(2, ("resuming decryption operation")); + return ssl_resume_decrypt_pms(ssl, + peer_pms, peer_pmslen, peer_pmssize); + } +#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */ + + /* + * Prepare to decrypt the premaster using own private RSA key + */ + if (p + 2 > end) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client key exchange message")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + if (*p++ != MBEDTLS_BYTE_1(len) || + *p++ != MBEDTLS_BYTE_0(len)) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client key exchange message")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + if (p + len != end) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client key exchange message")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + /* + * Decrypt the premaster secret + */ +#if defined(MBEDTLS_SSL_ASYNC_PRIVATE) + if (ssl->conf->f_async_decrypt_start != NULL) { + ret = ssl->conf->f_async_decrypt_start(ssl, + mbedtls_ssl_own_cert(ssl), + p, len); + switch (ret) { + case MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH: + /* act as if f_async_decrypt_start was null */ + break; + case 0: + ssl->handshake->async_in_progress = 1; + return ssl_resume_decrypt_pms(ssl, + peer_pms, + peer_pmslen, + peer_pmssize); + case MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS: + ssl->handshake->async_in_progress = 1; + return MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS; + default: + MBEDTLS_SSL_DEBUG_RET(1, "f_async_decrypt_start", ret); + return ret; + } + } +#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */ + + if (!mbedtls_pk_can_do(private_key, MBEDTLS_PK_RSA)) { + MBEDTLS_SSL_DEBUG_MSG(1, ("got no RSA private key")); + return MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED; + } + + ret = mbedtls_pk_decrypt(private_key, p, len, + peer_pms, peer_pmslen, peer_pmssize, + ssl->conf->f_rng, ssl->conf->p_rng); + return ret; +} + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_parse_encrypted_pms(mbedtls_ssl_context *ssl, + const unsigned char *p, + const unsigned char *end, + size_t pms_offset) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + unsigned char *pms = ssl->handshake->premaster + pms_offset; + unsigned char ver[2]; + unsigned char fake_pms[48], peer_pms[48]; + size_t peer_pmslen; + mbedtls_ct_condition_t diff; + + /* In case of a failure in decryption, the decryption may write less than + * 2 bytes of output, but we always read the first two bytes. It doesn't + * matter in the end because diff will be nonzero in that case due to + * ret being nonzero, and we only care whether diff is 0. + * But do initialize peer_pms and peer_pmslen for robustness anyway. This + * also makes memory analyzers happy (don't access uninitialized memory, + * even if it's an unsigned char). */ + peer_pms[0] = peer_pms[1] = ~0; + peer_pmslen = 0; + + ret = ssl_decrypt_encrypted_pms(ssl, p, end, + peer_pms, + &peer_pmslen, + sizeof(peer_pms)); + +#if defined(MBEDTLS_SSL_ASYNC_PRIVATE) + if (ret == MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS) { + return ret; + } +#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */ + + mbedtls_ssl_write_version(ver, ssl->conf->transport, + ssl->session_negotiate->tls_version); + + /* Avoid data-dependent branches while checking for invalid + * padding, to protect against timing-based Bleichenbacher-type + * attacks. */ + diff = mbedtls_ct_bool(ret); + diff = mbedtls_ct_bool_or(diff, mbedtls_ct_uint_ne(peer_pmslen, 48)); + diff = mbedtls_ct_bool_or(diff, mbedtls_ct_uint_ne(peer_pms[0], ver[0])); + diff = mbedtls_ct_bool_or(diff, mbedtls_ct_uint_ne(peer_pms[1], ver[1])); + + /* + * Protection against Bleichenbacher's attack: invalid PKCS#1 v1.5 padding + * must not cause the connection to end immediately; instead, send a + * bad_record_mac later in the handshake. + * To protect against timing-based variants of the attack, we must + * not have any branch that depends on whether the decryption was + * successful. In particular, always generate the fake premaster secret, + * regardless of whether it will ultimately influence the output or not. + */ + ret = ssl->conf->f_rng(ssl->conf->p_rng, fake_pms, sizeof(fake_pms)); + if (ret != 0) { + /* It's ok to abort on an RNG failure, since this does not reveal + * anything about the RSA decryption. */ + return ret; + } + +#if defined(MBEDTLS_SSL_DEBUG_ALL) + if (diff != MBEDTLS_CT_FALSE) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client key exchange message")); + } +#endif + + if (sizeof(ssl->handshake->premaster) < pms_offset || + sizeof(ssl->handshake->premaster) - pms_offset < 48) { + MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + ssl->handshake->pmslen = 48; + + /* Set pms to either the true or the fake PMS, without + * data-dependent branches. */ + mbedtls_ct_memcpy_if(diff, pms, fake_pms, peer_pms, ssl->handshake->pmslen); + + return 0; +} +#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED || + MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */ + +#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_parse_client_psk_identity(mbedtls_ssl_context *ssl, unsigned char **p, + const unsigned char *end) +{ + int ret = 0; + uint16_t n; + + if (ssl_conf_has_psk_or_cb(ssl->conf) == 0) { + MBEDTLS_SSL_DEBUG_MSG(1, ("got no pre-shared key")); + return MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED; + } + + /* + * Receive client pre-shared key identity name + */ + if (end - *p < 2) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client key exchange message")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + n = MBEDTLS_GET_UINT16_BE(*p, 0); + *p += 2; + + if (n == 0 || n > end - *p) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client key exchange message")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + if (ssl->conf->f_psk != NULL) { + if (ssl->conf->f_psk(ssl->conf->p_psk, ssl, *p, n) != 0) { + ret = MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY; + } + } else { + /* Identity is not a big secret since clients send it in the clear, + * but treat it carefully anyway, just in case */ + if (n != ssl->conf->psk_identity_len || + mbedtls_ct_memcmp(ssl->conf->psk_identity, *p, n) != 0) { + ret = MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY; + } + } + + if (ret == MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY) { + MBEDTLS_SSL_DEBUG_BUF(3, "Unknown PSK identity", *p, n); + mbedtls_ssl_send_alert_message(ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, + MBEDTLS_SSL_ALERT_MSG_UNKNOWN_PSK_IDENTITY); + return MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY; + } + + *p += n; + + return 0; +} +#endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */ + +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_parse_client_key_exchange(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + const mbedtls_ssl_ciphersuite_t *ciphersuite_info; + unsigned char *p, *end; + + ciphersuite_info = ssl->handshake->ciphersuite_info; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse client key exchange")); + +#if defined(MBEDTLS_SSL_ASYNC_PRIVATE) && \ + (defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) || \ + defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)) + if ((ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK || + ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA) && + (ssl->handshake->async_in_progress != 0)) { + /* We've already read a record and there is an asynchronous + * operation in progress to decrypt it. So skip reading the + * record. */ + MBEDTLS_SSL_DEBUG_MSG(3, ("will resume decryption of previously-read record")); + } else +#endif + if ((ret = mbedtls_ssl_read_record(ssl, 1)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_read_record", ret); + return ret; + } + + p = ssl->in_msg + mbedtls_ssl_hs_hdr_len(ssl); + end = ssl->in_msg + ssl->in_hslen; + + if (ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client key exchange message")); + return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; + } + + if (ssl->in_msg[0] != MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client key exchange message")); + return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; + } + +#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) + if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_RSA) { + if ((ret = ssl_parse_client_dh_public(ssl, &p, end)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, ("ssl_parse_client_dh_public"), ret); + return ret; + } + + if (p != end) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client key exchange")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + 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 MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + 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) + size_t data_len = (size_t) (*p++); + size_t buf_len = (size_t) (end - p); + psa_status_t status = PSA_ERROR_GENERIC_ERROR; + mbedtls_ssl_handshake_params *handshake = ssl->handshake; + + MBEDTLS_SSL_DEBUG_MSG(3, ("Read the peer's public key.")); + + /* + * We must have at least two bytes (1 for length, at least 1 for data) + */ + if (buf_len < 2) { + MBEDTLS_SSL_DEBUG_MSG(1, ("Invalid buffer length: %" MBEDTLS_PRINTF_SIZET, + buf_len)); + return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; + } + + if (data_len < 1 || data_len > buf_len) { + MBEDTLS_SSL_DEBUG_MSG(1, ("Invalid data length: %" MBEDTLS_PRINTF_SIZET + " > %" MBEDTLS_PRINTF_SIZET, + data_len, buf_len)); + return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; + } + + /* Store peer's ECDH public key. */ + if (data_len > sizeof(handshake->xxdh_psa_peerkey)) { + MBEDTLS_SSL_DEBUG_MSG(1, ("Invalid public key length: %" MBEDTLS_PRINTF_SIZET + " > %" MBEDTLS_PRINTF_SIZET, + data_len, + sizeof(handshake->xxdh_psa_peerkey))); + return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; + } + memcpy(handshake->xxdh_psa_peerkey, p, data_len); + handshake->xxdh_psa_peerkey_len = data_len; + + /* Compute ECDH shared secret. */ + status = psa_raw_key_agreement( + PSA_ALG_ECDH, handshake->xxdh_psa_privkey, + handshake->xxdh_psa_peerkey, handshake->xxdh_psa_peerkey_len, + handshake->premaster, sizeof(handshake->premaster), + &handshake->pmslen); + if (status != PSA_SUCCESS) { + ret = PSA_TO_MBEDTLS_ERR(status); + MBEDTLS_SSL_DEBUG_RET(1, "psa_raw_key_agreement", ret); + if (handshake->xxdh_psa_privkey_is_external == 0) { + (void) psa_destroy_key(handshake->xxdh_psa_privkey); + } + handshake->xxdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT; + return ret; + } + + if (handshake->xxdh_psa_privkey_is_external == 0) { + status = psa_destroy_key(handshake->xxdh_psa_privkey); + + if (status != PSA_SUCCESS) { + ret = PSA_TO_MBEDTLS_ERR(status); + MBEDTLS_SSL_DEBUG_RET(1, "psa_destroy_key", ret); + return ret; + } + } + handshake->xxdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT; +#else + if ((ret = mbedtls_ecdh_read_public(&ssl->handshake->ecdh_ctx, + p, (size_t) (end - p))) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecdh_read_public", ret); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + MBEDTLS_SSL_DEBUG_ECDH(3, &ssl->handshake->ecdh_ctx, + MBEDTLS_DEBUG_ECDH_QP); + + 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); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + 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_KEY_EXCHANGE_PSK_ENABLED) + if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK) { + if ((ret = ssl_parse_client_psk_identity(ssl, &p, end)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, ("ssl_parse_client_psk_identity"), ret); + return ret; + } + + if (p != end) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client key exchange")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + +#if !defined(MBEDTLS_USE_PSA_CRYPTO) + if ((ret = mbedtls_ssl_psk_derive_premaster(ssl, + (mbedtls_key_exchange_type_t) 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_PSK_ENABLED */ +#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED) + if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK) { +#if defined(MBEDTLS_SSL_ASYNC_PRIVATE) + if (ssl->handshake->async_in_progress != 0) { + /* There is an asynchronous operation in progress to + * decrypt the encrypted premaster secret, so skip + * directly to resuming this operation. */ + MBEDTLS_SSL_DEBUG_MSG(3, ("PSK identity already parsed")); + /* Update p to skip the PSK identity. ssl_parse_encrypted_pms + * won't actually use it, but maintain p anyway for robustness. */ + p += ssl->conf->psk_identity_len + 2; + } else +#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */ + if ((ret = ssl_parse_client_psk_identity(ssl, &p, end)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, ("ssl_parse_client_psk_identity"), ret); + return ret; + } + + if ((ret = ssl_parse_encrypted_pms(ssl, p, end, 2)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, ("ssl_parse_encrypted_pms"), ret); + return ret; + } + +#if !defined(MBEDTLS_USE_PSA_CRYPTO) + if ((ret = mbedtls_ssl_psk_derive_premaster(ssl, + (mbedtls_key_exchange_type_t) 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_RSA_PSK_ENABLED */ +#if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED) + if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK) { + if ((ret = ssl_parse_client_psk_identity(ssl, &p, end)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, ("ssl_parse_client_psk_identity"), ret); + return ret; + } + if ((ret = ssl_parse_client_dh_public(ssl, &p, end)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, ("ssl_parse_client_dh_public"), ret); + return ret; + } + + if (p != end) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad client key exchange")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + +#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); +#else + if ((ret = mbedtls_ssl_psk_derive_premaster(ssl, + (mbedtls_key_exchange_type_t) 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_DHE_PSK_ENABLED */ +#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) + if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK) { +#if defined(MBEDTLS_USE_PSA_CRYPTO) + psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; + psa_status_t destruction_status = PSA_ERROR_CORRUPTION_DETECTED; + uint8_t ecpoint_len; + + mbedtls_ssl_handshake_params *handshake = ssl->handshake; + + if ((ret = ssl_parse_client_psk_identity(ssl, &p, end)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, ("ssl_parse_client_psk_identity"), ret); + psa_destroy_key(handshake->xxdh_psa_privkey); + handshake->xxdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT; + return ret; + } + + /* Keep a copy of the peer's public key */ + if (p >= end) { + psa_destroy_key(handshake->xxdh_psa_privkey); + handshake->xxdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT; + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + ecpoint_len = *(p++); + if ((size_t) (end - p) < ecpoint_len) { + psa_destroy_key(handshake->xxdh_psa_privkey); + handshake->xxdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT; + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + /* When FFDH is enabled, the array handshake->xxdh_psa_peer_key size takes into account + the sizes of the FFDH keys which are at least 2048 bits. + The size of the array is thus greater than 256 bytes which is greater than any + possible value of ecpoint_len (type uint8_t) and the check below can be skipped.*/ +#if !defined(PSA_WANT_ALG_FFDH) + if (ecpoint_len > sizeof(handshake->xxdh_psa_peerkey)) { + psa_destroy_key(handshake->xxdh_psa_privkey); + handshake->xxdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT; + return MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE; + } +#else + MBEDTLS_STATIC_ASSERT(sizeof(handshake->xxdh_psa_peerkey) >= UINT8_MAX, + "peer key buffer too small"); +#endif + + memcpy(handshake->xxdh_psa_peerkey, p, ecpoint_len); + handshake->xxdh_psa_peerkey_len = ecpoint_len; + p += ecpoint_len; + + /* 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 *psm = ssl->handshake->premaster; + const unsigned char * const psm_end = + psm + sizeof(ssl->handshake->premaster); + /* uint16 to store length (in octets) of the ECDH computation */ + const size_t zlen_size = 2; + size_t zlen = 0; + + /* Compute ECDH shared secret. */ + status = psa_raw_key_agreement(PSA_ALG_ECDH, + handshake->xxdh_psa_privkey, + handshake->xxdh_psa_peerkey, + handshake->xxdh_psa_peerkey_len, + psm + zlen_size, + psm_end - (psm + zlen_size), + &zlen); + + destruction_status = psa_destroy_key(handshake->xxdh_psa_privkey); + handshake->xxdh_psa_privkey = MBEDTLS_SVC_KEY_ID_INIT; + + if (status != PSA_SUCCESS) { + return PSA_TO_MBEDTLS_ERR(status); + } else if (destruction_status != PSA_SUCCESS) { + return PSA_TO_MBEDTLS_ERR(destruction_status); + } + + /* Write the ECDH computation length before the ECDH computation */ + MBEDTLS_PUT_UINT16_BE(zlen, psm, 0); + psm += zlen_size + zlen; + +#else /* MBEDTLS_USE_PSA_CRYPTO */ + if ((ret = ssl_parse_client_psk_identity(ssl, &p, end)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, ("ssl_parse_client_psk_identity"), ret); + return ret; + } + + if ((ret = mbedtls_ecdh_read_public(&ssl->handshake->ecdh_ctx, + p, (size_t) (end - p))) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecdh_read_public", ret); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + MBEDTLS_SSL_DEBUG_ECDH(3, &ssl->handshake->ecdh_ctx, + MBEDTLS_DEBUG_ECDH_QP); + + if ((ret = mbedtls_ssl_psk_derive_premaster(ssl, + (mbedtls_key_exchange_type_t) 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_ECDHE_PSK_ENABLED */ +#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) + if (ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA) { + if ((ret = ssl_parse_encrypted_pms(ssl, p, end, 0)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, ("ssl_parse_parse_encrypted_pms_secret"), ret); + 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) { +#if defined(MBEDTLS_USE_PSA_CRYPTO) + if ((ret = mbedtls_psa_ecjpake_read_round( + &ssl->handshake->psa_pake_ctx, p, (size_t) (end - p), + MBEDTLS_ECJPAKE_ROUND_TWO)) != 0) { + psa_destroy_key(ssl->handshake->psa_pake_password); + psa_pake_abort(&ssl->handshake->psa_pake_ctx); + + MBEDTLS_SSL_DEBUG_RET(1, "psa_pake_input round two", ret); + return ret; + } +#else + ret = mbedtls_ecjpake_read_round_two(&ssl->handshake->ecjpake_ctx, + p, (size_t) (end - p)); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecjpake_read_round_two", ret); + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + + ret = mbedtls_ecjpake_derive_secret(&ssl->handshake->ecjpake_ctx, + ssl->handshake->premaster, 32, &ssl->handshake->pmslen, + ssl->conf->f_rng, ssl->conf->p_rng); + if (ret != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ecjpake_derive_secret", ret); + return ret; + } +#endif /* MBEDTLS_USE_PSA_CRYPTO */ + } else +#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */ + { + MBEDTLS_SSL_DEBUG_MSG(1, ("should never happen")); + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + + if ((ret = mbedtls_ssl_derive_keys(ssl)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_derive_keys", ret); + return ret; + } + + ssl->state++; + + MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse client key exchange")); + + return 0; +} + +#if !defined(MBEDTLS_KEY_EXCHANGE_CERT_REQ_ALLOWED_ENABLED) +MBEDTLS_CHECK_RETURN_CRITICAL +static int ssl_parse_certificate_verify(mbedtls_ssl_context *ssl) +{ + const mbedtls_ssl_ciphersuite_t *ciphersuite_info = + ssl->handshake->ciphersuite_info; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse certificate verify")); + + if (!mbedtls_ssl_ciphersuite_cert_req_allowed(ciphersuite_info)) { + MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip parse 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_parse_certificate_verify(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE; + size_t i, sig_len; + unsigned char hash[48]; + unsigned char *hash_start = hash; + size_t hashlen; + mbedtls_pk_type_t pk_alg; + mbedtls_md_type_t md_alg; + const mbedtls_ssl_ciphersuite_t *ciphersuite_info = + ssl->handshake->ciphersuite_info; + mbedtls_pk_context *peer_pk; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse certificate verify")); + + if (!mbedtls_ssl_ciphersuite_cert_req_allowed(ciphersuite_info)) { + MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip parse certificate verify")); + ssl->state++; + return 0; + } + +#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) + if (ssl->session_negotiate->peer_cert == NULL) { + MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip parse certificate verify")); + ssl->state++; + return 0; + } +#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ + if (ssl->session_negotiate->peer_cert_digest == NULL) { + MBEDTLS_SSL_DEBUG_MSG(2, ("<= skip parse certificate verify")); + ssl->state++; + return 0; + } +#endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ + + /* Read the message without adding it to the checksum */ + ret = mbedtls_ssl_read_record(ssl, 0 /* no checksum update */); + if (0 != ret) { + MBEDTLS_SSL_DEBUG_RET(1, ("mbedtls_ssl_read_record"), ret); + return ret; + } + + ssl->state++; + + /* Process the message contents */ + if (ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE || + ssl->in_msg[0] != MBEDTLS_SSL_HS_CERTIFICATE_VERIFY) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad certificate verify message")); + return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; + } + + i = mbedtls_ssl_hs_hdr_len(ssl); + +#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 */ + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + peer_pk = &ssl->session_negotiate->peer_cert->pk; +#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */ + + /* + * struct { + * SignatureAndHashAlgorithm algorithm; -- TLS 1.2 only + * opaque signature<0..2^16-1>; + * } DigitallySigned; + */ + if (i + 2 > ssl->in_hslen) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad certificate verify message")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + /* + * Hash + */ + md_alg = mbedtls_ssl_md_alg_from_hash(ssl->in_msg[i]); + + if (md_alg == MBEDTLS_MD_NONE || mbedtls_ssl_set_calc_verify_md(ssl, ssl->in_msg[i])) { + MBEDTLS_SSL_DEBUG_MSG(1, ("peer not adhering to requested sig_alg" + " for verify message")); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + +#if !defined(MBEDTLS_MD_SHA1) + if (MBEDTLS_MD_SHA1 == md_alg) { + hash_start += 16; + } +#endif + + /* Info from md_alg will be used instead */ + hashlen = 0; + + i++; + + /* + * Signature + */ + if ((pk_alg = mbedtls_ssl_pk_alg_from_sig(ssl->in_msg[i])) + == MBEDTLS_PK_NONE) { + MBEDTLS_SSL_DEBUG_MSG(1, ("peer not adhering to requested sig_alg" + " for verify message")); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + + /* + * Check the certificate's key type matches the signature alg + */ + if (!mbedtls_pk_can_do(peer_pk, pk_alg)) { + MBEDTLS_SSL_DEBUG_MSG(1, ("sig_alg doesn't match cert key")); + return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER; + } + + i++; + + if (i + 2 > ssl->in_hslen) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad certificate verify message")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + sig_len = MBEDTLS_GET_UINT16_BE(ssl->in_msg, i); + i += 2; + + if (i + sig_len != ssl->in_hslen) { + MBEDTLS_SSL_DEBUG_MSG(1, ("bad certificate verify message")); + return MBEDTLS_ERR_SSL_DECODE_ERROR; + } + + /* Calculate hash and verify signature */ + { + size_t dummy_hlen; + ret = ssl->handshake->calc_verify(ssl, hash, &dummy_hlen); + if (0 != ret) { + MBEDTLS_SSL_DEBUG_RET(1, ("calc_verify"), ret); + return ret; + } + } + + if ((ret = mbedtls_pk_verify(peer_pk, + md_alg, hash_start, hashlen, + ssl->in_msg + i, sig_len)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_pk_verify", ret); + return ret; + } + + ret = mbedtls_ssl_update_handshake_status(ssl); + if (0 != ret) { + MBEDTLS_SSL_DEBUG_RET(1, ("mbedtls_ssl_update_handshake_status"), ret); + return ret; + } + + MBEDTLS_SSL_DEBUG_MSG(2, ("<= parse 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_write_new_session_ticket(mbedtls_ssl_context *ssl) +{ + int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; + size_t tlen; + uint32_t lifetime; + + MBEDTLS_SSL_DEBUG_MSG(2, ("=> write new session ticket")); + + ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE; + ssl->out_msg[0] = MBEDTLS_SSL_HS_NEW_SESSION_TICKET; + + /* + * struct { + * uint32 ticket_lifetime_hint; + * opaque ticket<0..2^16-1>; + * } NewSessionTicket; + * + * 4 . 7 ticket_lifetime_hint (0 = unspecified) + * 8 . 9 ticket_len (n) + * 10 . 9+n ticket content + */ + +#if defined(MBEDTLS_HAVE_TIME) + ssl->session_negotiate->ticket_creation_time = mbedtls_ms_time(); +#endif + if ((ret = ssl->conf->f_ticket_write(ssl->conf->p_ticket, + ssl->session_negotiate, + ssl->out_msg + 10, + ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN, + &tlen, &lifetime)) != 0) { + MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_ticket_write", ret); + tlen = 0; + } + + MBEDTLS_PUT_UINT32_BE(lifetime, ssl->out_msg, 4); + MBEDTLS_PUT_UINT16_BE(tlen, ssl->out_msg, 8); + ssl->out_msglen = 10 + tlen; + + /* + * Morally equivalent to updating ssl->state, but NewSessionTicket and + * ChangeCipherSpec share the same state. + */ + ssl->handshake->new_session_ticket = 0; + + 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 new session ticket")); + + return 0; +} +#endif /* MBEDTLS_SSL_SESSION_TICKETS */ + +/* + * SSL handshake -- server side -- single step + */ +int mbedtls_ssl_handshake_server_step(mbedtls_ssl_context *ssl) +{ + int ret = 0; + + MBEDTLS_SSL_DEBUG_MSG(2, ("server state: %d", ssl->state)); + + switch (ssl->state) { + case MBEDTLS_SSL_HELLO_REQUEST: + ssl->state = MBEDTLS_SSL_CLIENT_HELLO; + break; + + /* + * <== ClientHello + */ + case MBEDTLS_SSL_CLIENT_HELLO: + ret = ssl_parse_client_hello(ssl); + break; + +#if defined(MBEDTLS_SSL_PROTO_DTLS) + case MBEDTLS_SSL_SERVER_HELLO_VERIFY_REQUEST_SENT: + return MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED; +#endif + + /* + * ==> ServerHello + * Certificate + * ( ServerKeyExchange ) + * ( CertificateRequest ) + * ServerHelloDone + */ + case MBEDTLS_SSL_SERVER_HELLO: + ret = ssl_write_server_hello(ssl); + break; + + case MBEDTLS_SSL_SERVER_CERTIFICATE: + ret = mbedtls_ssl_write_certificate(ssl); + break; + + case MBEDTLS_SSL_SERVER_KEY_EXCHANGE: + ret = ssl_write_server_key_exchange(ssl); + break; + + case MBEDTLS_SSL_CERTIFICATE_REQUEST: + ret = ssl_write_certificate_request(ssl); + break; + + case MBEDTLS_SSL_SERVER_HELLO_DONE: + ret = ssl_write_server_hello_done(ssl); + break; + + /* + * <== ( Certificate/Alert ) + * ClientKeyExchange + * ( CertificateVerify ) + * ChangeCipherSpec + * Finished + */ + case MBEDTLS_SSL_CLIENT_CERTIFICATE: + ret = mbedtls_ssl_parse_certificate(ssl); + break; + + case MBEDTLS_SSL_CLIENT_KEY_EXCHANGE: + ret = ssl_parse_client_key_exchange(ssl); + break; + + case MBEDTLS_SSL_CERTIFICATE_VERIFY: + ret = ssl_parse_certificate_verify(ssl); + break; + + case MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC: + ret = mbedtls_ssl_parse_change_cipher_spec(ssl); + break; + + case MBEDTLS_SSL_CLIENT_FINISHED: + ret = mbedtls_ssl_parse_finished(ssl); + break; + + /* + * ==> ( NewSessionTicket ) + * ChangeCipherSpec + * Finished + */ + case MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC: +#if defined(MBEDTLS_SSL_SESSION_TICKETS) + if (ssl->handshake->new_session_ticket != 0) { + ret = ssl_write_new_session_ticket(ssl); + } else +#endif + ret = mbedtls_ssl_write_change_cipher_spec(ssl); + break; + + case MBEDTLS_SSL_SERVER_FINISHED: + ret = mbedtls_ssl_write_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; +} + +void mbedtls_ssl_conf_preference_order(mbedtls_ssl_config *conf, int order) +{ + conf->respect_cli_pref = order; +} + +#endif /* MBEDTLS_SSL_SRV_C && MBEDTLS_SSL_PROTO_TLS1_2 */ |