/
ssl_tls12_server.c
4415 lines (3755 loc) · 156 KB
/
ssl_tls12_server.c
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/*
* TLS server-side functions
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "common.h"
#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_PROTO_TLS1_2)
#include "mbedtls/platform.h"
#include "mbedtls/ssl.h"
#include "ssl_misc.h"
#include "mbedtls/debug.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 = ((buf[0] << 8) | (buf[1]));
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_ec_ro(*pk)->grp.id;
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",
(ssl->in_len[0] << 8) | ssl->in_len[1]));
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;
}