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17c3531b4b
mbedtls/library/ssl_cli.c
Andrzej Kurek 17c3531b4b Add missing volatile identifiers before fi-related variables 
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-12-31 09:56:42 -05:00

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/*
* SSLv3/TLSv1 client-side functions
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* 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.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_SSL_CLI_C)
#include "mbedtls/platform.h"
#if !defined(MBEDTLS_PLATFORM_C)
#include <stdlib.h>
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#include "mbedtls/debug.h"
#include "mbedtls/ssl.h"
#include "mbedtls/ssl_internal.h"
#include <string.h>
#include <stdint.h>
#if defined(MBEDTLS_HAVE_TIME)
#include "mbedtls/platform_time.h"
#endif
#include "mbedtls/platform.h"
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
#include "mbedtls/platform_util.h"
#endif
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) && !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
static void ssl_write_hostname_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
size_t hostname_len;
*olen = 0;
if( ssl->hostname == NULL )
return;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding server name extension: %s",
ssl->hostname ) );
hostname_len = strlen( ssl->hostname );
if( end < p || (size_t)( end - p ) < hostname_len + 9 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
/*
* Sect. 3, RFC 6066 (TLS Extensions Definitions)
*
* In order to provide any of the server names, clients MAY include an
* extension of type "server_name" in the (extended) client hello. The
* "extension_data" field of this extension SHALL contain
* "ServerNameList" where:
*
* struct {
* NameType name_type;
* select (name_type) {
* case host_name: HostName;
* } name;
* } ServerName;
*
* enum {
* host_name(0), (255)
* } NameType;
*
* opaque HostName<1..2^16-1>;
*
* struct {
* ServerName server_name_list<1..2^16-1>
* } ServerNameList;
*
*/
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_SERVERNAME );
p = mbedtls_platform_put_uint16_be( p, hostname_len + 5 );
p = mbedtls_platform_put_uint16_be( p, hostname_len + 3 );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME ) & 0xFF );
p = mbedtls_platform_put_uint16_be( p, hostname_len );
mbedtls_platform_memcpy( p, ssl->hostname, hostname_len );
*olen = hostname_len + 9;
}
#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION && !MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION */
#if defined(MBEDTLS_SSL_RENEGOTIATION)
static void ssl_write_renegotiation_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
*olen = 0;
/* We're always including an TLS_EMPTY_RENEGOTIATION_INFO_SCSV in the
* initial ClientHello, in which case also adding the renegotiation
* info extension is NOT RECOMMENDED as per RFC 5746 Section 3.4. */
if( ssl->renego_status != MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
return;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding renegotiation extension" ) );
if( end < p || (size_t)( end - p ) < 5 + ssl->verify_data_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
/*
* Secure renegotiation
*/
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_RENEGOTIATION_INFO );
*p++ = 0x00;
*p++ = ( ssl->verify_data_len + 1 ) & 0xFF;
*p++ = ssl->verify_data_len & 0xFF;
mbedtls_platform_memcpy( p, ssl->own_verify_data, ssl->verify_data_len );
*olen = 5 + ssl->verify_data_len;
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
/*
* Only if we handle at least one key exchange that needs signatures.
*/
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
static void ssl_write_signature_algorithms_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
size_t sig_alg_len = 0;
#if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_USE_TINYCRYPT)
unsigned char *sig_alg_list = buf + 6;
#endif
*olen = 0;
if( mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) !=
MBEDTLS_SSL_MINOR_VERSION_3 )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding signature_algorithms extension" ) );
MBEDTLS_SSL_BEGIN_FOR_EACH_SIG_HASH_TLS( hash )
((void) hash);
#if defined(MBEDTLS_ECDSA_C) || defined(MBEDTLS_USE_TINYCRYPT)
sig_alg_len += 2;
#endif
#if defined(MBEDTLS_RSA_C)
sig_alg_len += 2;
#endif
MBEDTLS_SSL_END_FOR_EACH_SIG_HASH_TLS
if( end < p || (size_t)( end - p ) < sig_alg_len + 6 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
/*
* Prepare signature_algorithms extension (TLS 1.2)
*/
sig_alg_len = 0;
MBEDTLS_SSL_BEGIN_FOR_EACH_SIG_HASH_TLS( hash )
#if defined(MBEDTLS_ECDSA_C) || defined(MBEDTLS_USE_TINYCRYPT)
sig_alg_list[sig_alg_len++] = hash;
sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_ECDSA;
#endif
#if defined(MBEDTLS_RSA_C)
sig_alg_list[sig_alg_len++] = hash;
sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_RSA;
#endif
MBEDTLS_SSL_END_FOR_EACH_SIG_HASH_TLS
/*
* enum {
* none(0), md5(1), sha1(2), sha224(3), sha256(4), sha384(5),
* sha512(6), (255)
* } HashAlgorithm;
*
* enum { anonymous(0), rsa(1), dsa(2), ecdsa(3), (255) }
* SignatureAlgorithm;
*
* struct {
* HashAlgorithm hash;
* SignatureAlgorithm signature;
* } SignatureAndHashAlgorithm;
*
* SignatureAndHashAlgorithm
* supported_signature_algorithms<2..2^16-2>;
*/
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_SIG_ALG );
p = mbedtls_platform_put_uint16_be( p, ( sig_alg_len + 2 ) );
p = mbedtls_platform_put_uint16_be( p, sig_alg_len );
*olen = 6 + sig_alg_len;
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
#if defined(MBEDTLS_ECDH_C) || \
defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_USE_TINYCRYPT) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
static size_t ssl_get_ec_curve_list_length( mbedtls_ssl_context *ssl )
{
size_t ec_list_len = 0;
MBEDTLS_SSL_BEGIN_FOR_EACH_SUPPORTED_EC_TLS_ID( tls_id )
((void) tls_id);
ec_list_len++;
MBEDTLS_SSL_END_FOR_EACH_SUPPORTED_EC_TLS_ID
return( ec_list_len );
}
static void ssl_write_supported_elliptic_curves_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
size_t elliptic_curve_len = 0;
*olen = 0;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported_elliptic_curves extension" ) );
/* Each elliptic curve is encoded in 2 bytes. */
elliptic_curve_len = 2 * ssl_get_ec_curve_list_length( ssl );
if( elliptic_curve_len == 0 )
return;
if( end < p || (size_t)( end - p ) < 6 + elliptic_curve_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES );
p = mbedtls_platform_put_uint16_be( p, elliptic_curve_len + 2 );
p = mbedtls_platform_put_uint16_be( p, elliptic_curve_len );
MBEDTLS_SSL_BEGIN_FOR_EACH_SUPPORTED_EC_TLS_ID( tls_id )
p = mbedtls_platform_put_uint16_be( p, tls_id );
MBEDTLS_SSL_END_FOR_EACH_SUPPORTED_EC_TLS_ID
*olen = 6 + elliptic_curve_len;
}
static void ssl_write_supported_point_formats_ext( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
*olen = 0;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported_point_formats extension" ) );
if( end < p || (size_t)( end - p ) < 6 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS );
*p++ = 0x00;
*p++ = 2;
*p++ = 1;
*p++ = MBEDTLS_SSL_EC_PF_UNCOMPRESSED;
*olen = 6;
}
#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C || MBEDTLS_USE_TINYCRYPT ||
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;
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
size_t kkpp_len;
*olen = 0;
/* Skip costly extension if we can't use EC J-PAKE anyway */
if( mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 )
return;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding ecjpake_kkpp extension" ) );
if( end - p < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_ECJPAKE_KKPP );
/*
* We may need to send ClientHello multiple times for Hello verification.
* We don't want to compute fresh values every time (both for performance
* and consistency reasons), so cache the extension content.
*/
if( ssl->handshake->ecjpake_cache == NULL ||
ssl->handshake->ecjpake_cache_len == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "generating new ecjpake parameters" ) );
ret = mbedtls_ecjpake_write_round_one( &ssl->handshake->ecjpake_ctx,
p + 2, end - p - 2, &kkpp_len,
mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1 , "mbedtls_ecjpake_write_round_one", ret );
return;
}
ssl->handshake->ecjpake_cache = mbedtls_calloc( 1, kkpp_len );
if( ssl->handshake->ecjpake_cache == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "allocation failed" ) );
return;
}
mbedtls_platform_memcpy( ssl->handshake->ecjpake_cache, p + 2, kkpp_len );
ssl->handshake->ecjpake_cache_len = kkpp_len;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "re-using cached ecjpake parameters" ) );
kkpp_len = ssl->handshake->ecjpake_cache_len;
if( (size_t)( end - p - 2 ) < kkpp_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
mbedtls_platform_memcpy( p + 2, ssl->handshake->ecjpake_cache, kkpp_len );
}
p = mbedtls_platform_put_uint16_be( p, kkpp_len );
*olen = kkpp_len + 4;
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#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;
/*
* Quoting draft-ietf-tls-dtls-connection-id-05
* https://tools.ietf.org/html/draft-ietf-tls-dtls-connection-id-05
*
* struct {
* opaque cid<0..2^8-1>;
* } ConnectionId;
*/
*olen = 0;
if( MBEDTLS_SSL_TRANSPORT_IS_TLS( ssl->conf->transport ) ||
ssl->negotiate_cid == MBEDTLS_SSL_CID_DISABLED )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding CID extension" ) );
/* ssl->own_cid_len is at most MBEDTLS_SSL_CID_IN_LEN_MAX
* which is at most 255, so the increment cannot overflow. */
if( end < p || (size_t)( end - p ) < (unsigned)( ssl->own_cid_len + 5 ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
/* Add extension ID + size */
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_CID );
ext_len = (size_t) ssl->own_cid_len + 1;
p = mbedtls_platform_put_uint16_be( p, ext_len );
*p++ = (uint8_t) ssl->own_cid_len;
/* Not using more secure mbedtls_platform_memcpy as cid is public */
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_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;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
*olen = 0;
if( ssl->conf->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE ) {
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding max_fragment_length extension" ) );
if( end < p || (size_t)( end - p ) < 5 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH );
*p++ = 0x00;
*p++ = 1;
*p++ = ssl->conf->mfl_code;
*olen = 5;
}
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
static void ssl_write_truncated_hmac_ext( mbedtls_ssl_context *ssl,
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
*olen = 0;
if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding truncated_hmac extension" ) );
if( end < p || (size_t)( end - p ) < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_TRUNCATED_HMAC );
*p++ = 0x00;
*p++ = 0x00;
*olen = 4;
}
#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
static void ssl_write_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
*olen = 0;
if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ==
MBEDTLS_SSL_MINOR_VERSION_0 )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding encrypt_then_mac "
"extension" ) );
if( end < p || (size_t)( end - p ) < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC );
*p++ = 0x00;
*p++ = 0x00;
*olen = 4;
}
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
#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;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
*olen = 0;
if( mbedtls_ssl_conf_get_ems( ssl->conf ) ==
MBEDTLS_SSL_EXTENDED_MS_DISABLED ||
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ==
MBEDTLS_SSL_MINOR_VERSION_0 )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding extended_master_secret "
"extension" ) );
if( end < p || (size_t)( end - p ) < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET );
*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;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
size_t tlen = ssl->session_negotiate->ticket_len;
*olen = 0;
if( ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding session ticket extension" ) );
if( end < p || (size_t)( end - p ) < 4 + tlen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_SESSION_TICKET );
p = mbedtls_platform_put_uint16_be( p, tlen );
*olen = 4;
if( ssl->session_negotiate->ticket == NULL || tlen == 0 )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "sending session ticket of length %d", tlen ) );
mbedtls_platform_memcpy( p, ssl->session_negotiate->ticket, tlen );
*olen += tlen;
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_SSL_ALPN)
static void ssl_write_alpn_ext( mbedtls_ssl_context *ssl,
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_OUT_CONTENT_LEN;
size_t alpnlen = 0;
const char **cur;
*olen = 0;
if( ssl->conf->alpn_list == NULL )
{
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding alpn extension" ) );
for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
alpnlen += (unsigned char)( strlen( *cur ) & 0xFF ) + 1;
if( end < p || (size_t)( end - p ) < 6 + alpnlen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
return;
}
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_TLS_EXT_ALPN );
/*
* opaque ProtocolName<1..2^8-1>;
*
* struct {
* ProtocolName protocol_name_list<2..2^16-1>
* } ProtocolNameList;
*/
/* Skip writing extension and list length for now */
p += 4;
for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
{
*p = (unsigned char)( strlen( *cur ) & 0xFF );
mbedtls_platform_memcpy( p + 1, *cur, *p );
p += 1 + *p;
}
*olen = p - buf;
/* List length = olen - 2 (ext_type) - 2 (ext_len) - 2 (list_len) */
(void)mbedtls_platform_put_uint16_be( &buf[4], ( *olen - 6 ) );
/* Extension length = olen - 2 (ext_type) - 2 (ext_len) */
(void)mbedtls_platform_put_uint16_be( &buf[2], ( *olen - 4 ) );
}
#endif /* MBEDTLS_SSL_ALPN */
/*
* Generate random bytes for ClientHello
*/
static int ssl_generate_random( mbedtls_ssl_context *ssl )
{
volatile int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
unsigned char *p = ssl->handshake->randbytes;
#if defined(MBEDTLS_HAVE_TIME)
mbedtls_time_t t;
#endif
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_UNSET;
/*
* When responding to a verify request, MUST reuse random (RFC 6347 4.2.1)
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) &&
ssl->handshake->verify_cookie != NULL )
{
return( 0 );
}
#endif
#if defined(MBEDTLS_HAVE_TIME)
t = mbedtls_time( NULL );
p = mbedtls_platform_put_uint32_be( p, (uint32_t) t );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, current time: %lu", t ) );
#else
if( ( ret = mbedtls_ssl_conf_get_frng( ssl->conf )
( mbedtls_ssl_conf_get_prng( ssl->conf ), p, 4 ) ) != 0 )
{
return( ret );
}
p += 4;
#endif /* MBEDTLS_HAVE_TIME */
ret = mbedtls_ssl_conf_get_frng( ssl->conf )
( mbedtls_ssl_conf_get_prng( ssl->conf ), p, 28 );
if( ret == 0 )
{
mbedtls_platform_random_delay();
if( ret == 0 )
{
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_SET;
return( 0 );
}
else
{
ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
}
}
return( ret );
}
/**
* \brief Validate cipher suite against config in SSL context.
*
* \param suite_info cipher suite to validate
* \param ssl SSL context
* \param min_minor_ver Minimal minor version to accept a cipher suite
* \param max_minor_ver Maximal minor version to accept a cipher suite
*
* \return 0 if valid, else 1
*/
static int ssl_validate_ciphersuite( mbedtls_ssl_ciphersuite_handle_t suite_info,
const mbedtls_ssl_context * ssl,
int min_minor_ver, int max_minor_ver )
{
(void) ssl;
if( suite_info == MBEDTLS_SSL_CIPHERSUITE_INVALID_HANDLE )
return( 1 );
if( mbedtls_ssl_ver_gt( mbedtls_ssl_suite_get_min_minor_ver( suite_info ),
max_minor_ver ) ||
mbedtls_ssl_ver_lt( mbedtls_ssl_suite_get_max_minor_ver( suite_info ),
min_minor_ver ) )
{
return( 1 );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) &&
( mbedtls_ssl_suite_get_flags( suite_info ) &
MBEDTLS_CIPHERSUITE_NODTLS ) != 0 )
{
return( 1 );
}
#endif
#if defined(MBEDTLS_ARC4_C)
if( ssl->conf->arc4_disabled == MBEDTLS_SSL_ARC4_DISABLED &&
mbedtls_ssl_suite_get_cipher( suite_info ) == MBEDTLS_CIPHER_ARC4_128 )
{
return( 1 );
}
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( suite_info ) ==
MBEDTLS_KEY_EXCHANGE_ECJPAKE &&
mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 )
{
return( 1 );
}
#endif
return( 0 );
}
static int ssl_write_client_hello( mbedtls_ssl_context *ssl )
{
int ret;
size_t i, n, olen, ext_len = 0;
unsigned char *buf;
unsigned char *p, *q;
unsigned char offer_compress;
#if defined(MBEDTLS_USE_TINYCRYPT) || \
defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
int uses_ec = 0;
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write client hello" ) );
if( mbedtls_ssl_conf_get_frng( ssl->conf ) == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "no RNG provided") );
return( MBEDTLS_ERR_SSL_NO_RNG );
}
if( mbedtls_ssl_get_renego_status( ssl ) == MBEDTLS_SSL_INITIAL_HANDSHAKE )
{
#if !defined(MBEDTLS_SSL_CONF_FIXED_MAJOR_VER)
ssl->major_ver = mbedtls_ssl_conf_get_min_major_ver( ssl->conf );
#endif /* !MBEDTLS_SSL_CONF_FIXED_MAJOR_VER */
#if !defined(MBEDTLS_SSL_CONF_FIXED_MINOR_VER)
ssl->minor_ver = mbedtls_ssl_conf_get_min_minor_ver( ssl->conf );
#endif /* !MBEDTLS_SSL_CONF_FIXED_MINOR_VER */
}
if( mbedtls_ssl_conf_get_max_major_ver( ssl->conf ) == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "configured max major version is invalid, "
"consider using mbedtls_ssl_config_defaults()" ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
/*
* 0 . 0 handshake type
* 1 . 3 handshake length
* 4 . 5 highest version supported
* 6 . 9 current UNIX time
* 10 . 37 random bytes
*/
buf = ssl->out_msg;
p = buf + 4;
mbedtls_ssl_write_version( mbedtls_ssl_conf_get_max_major_ver( ssl->conf ),
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ),
mbedtls_ssl_conf_get_transport( ssl->conf ), p );
p += 2;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, max version: [%d:%d]",
buf[4], buf[5] ) );
if( ( ret = ssl_generate_random( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_generate_random", ret );
return( ret );
}
mbedtls_platform_memcpy( p, ssl->handshake->randbytes, 32 );
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes", p, 32 );
p += 32;
/*
* 38 . 38 session id length
* 39 . 39+n session id
* 39+n . 39+n DTLS only: cookie length (1 byte)
* 40+n . .. DTSL only: cookie
* .. . .. ciphersuitelist length (2 bytes)
* .. . .. ciphersuitelist
* .. . .. compression methods length (1 byte)
* .. . .. compression methods
* .. . .. extensions length (2 bytes)
* .. . .. extensions
*/
/*
* We'll write a session of non-zero length if resumption was requested
* by the user, we're not renegotiating, and the session ID is of
* appropriate length. Otherwise make the length 0 (for now, see next code
* block for behaviour with tickets).
*/
if( mbedtls_ssl_handshake_get_resume( ssl->handshake ) == MBEDTLS_SSL_FI_FLAG_UNSET ||
mbedtls_ssl_get_renego_status( ssl ) != MBEDTLS_SSL_INITIAL_HANDSHAKE ||
ssl->session_negotiate->id_len < 16 ||
ssl->session_negotiate->id_len > 32 )
{
n = 0;
}
else
{
n = ssl->session_negotiate->id_len;
}
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
/*
* RFC 5077 section 3.4: "When presenting a ticket, the client MAY
* generate and include a Session ID in the TLS ClientHello."
*/
if( mbedtls_ssl_get_renego_status( ssl ) == MBEDTLS_SSL_INITIAL_HANDSHAKE &&
ssl->session_negotiate->ticket != NULL &&
ssl->session_negotiate->ticket_len != 0 )
{
ret = mbedtls_ssl_conf_get_frng( ssl->conf )
( mbedtls_ssl_conf_get_prng( ssl->conf ), ssl->session_negotiate->id, 32 );
if( ret != 0 )
return( ret );
ssl->session_negotiate->id_len = n = 32;
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
*p++ = (unsigned char) n;
for( i = 0; i < n; i++ )
*p++ = ssl->session_negotiate->id[i];
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, session id len.: %d", n ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id", buf + 39, n );
/*
* DTLS cookie
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) )
{
if( ssl->handshake->verify_cookie == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "no verify cookie to send" ) );
*p++ = 0;
}
else
{
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, cookie",
ssl->handshake->verify_cookie,
ssl->handshake->verify_cookie_len );
*p++ = ssl->handshake->verify_cookie_len;
mbedtls_platform_memcpy( p, ssl->handshake->verify_cookie,
ssl->handshake->verify_cookie_len );
p += ssl->handshake->verify_cookie_len;
}
}
#endif
/*
* Ciphersuite list
*/
/* Skip writing ciphersuite length for now */
n = 0;
q = p;
p += 2;
MBEDTLS_SSL_BEGIN_FOR_EACH_CIPHERSUITE( ssl,
mbedtls_ssl_get_minor_ver( ssl ),
ciphersuite_info )
{
if( ssl_validate_ciphersuite( ciphersuite_info, ssl,
mbedtls_ssl_conf_get_min_minor_ver( ssl->conf ),
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ) != 0 )
{
continue;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, add ciphersuite: %04x",
mbedtls_ssl_suite_get_id( ciphersuite_info ) ) );
#if defined(MBEDTLS_USE_TINYCRYPT) || \
defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
uses_ec |= mbedtls_ssl_ciphersuite_uses_ec( ciphersuite_info );
#endif
n++;
*p++ = (unsigned char)(
mbedtls_ssl_suite_get_id( ciphersuite_info ) >> 8 );
*p++ = (unsigned char)(
mbedtls_ssl_suite_get_id( ciphersuite_info ) );
}
MBEDTLS_SSL_END_FOR_EACH_CIPHERSUITE
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, got %d ciphersuites (excluding SCSVs)", n ) );
/*
* Add TLS_EMPTY_RENEGOTIATION_INFO_SCSV
*/
if( mbedtls_ssl_get_renego_status( ssl ) == MBEDTLS_SSL_INITIAL_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "adding EMPTY_RENEGOTIATION_INFO_SCSV" ) );
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO );
n++;
}
/* Some versions of OpenSSL don't handle it correctly if not at end */
#if defined(MBEDTLS_SSL_FALLBACK_SCSV)
if( ssl->conf->fallback == MBEDTLS_SSL_IS_FALLBACK )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "adding FALLBACK_SCSV" ) );
p = mbedtls_platform_put_uint16_be( p, MBEDTLS_SSL_FALLBACK_SCSV_VALUE );
n++;
}
#endif
*q++ = (unsigned char)( n >> 7 );
*q++ = (unsigned char)( n << 1 );
#if defined(MBEDTLS_ZLIB_SUPPORT)
offer_compress = 1;
#else
offer_compress = 0;
#endif
/*
* We don't support compression with DTLS right now: if many records come
* in the same datagram, uncompressing one could overwrite the next one.
* We don't want to add complexity for handling that case unless there is
* an actual need for it.
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) )
offer_compress = 0;
#endif
if( offer_compress )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 2 ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d %d",
MBEDTLS_SSL_COMPRESS_DEFLATE, MBEDTLS_SSL_COMPRESS_NULL ) );
*p++ = 2;
*p++ = MBEDTLS_SSL_COMPRESS_DEFLATE;
*p++ = MBEDTLS_SSL_COMPRESS_NULL;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 1 ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d",
MBEDTLS_SSL_COMPRESS_NULL ) );
*p++ = 1;
*p++ = MBEDTLS_SSL_COMPRESS_NULL;
}
// First write extensions, then the total length
//
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) && !defined(MBEDTLS_X509_REMOVE_HOSTNAME_VERIFICATION)
ssl_write_hostname_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
/* Note that TLS_EMPTY_RENEGOTIATION_INFO_SCSV is always added
* even if MBEDTLS_SSL_RENEGOTIATION is not defined. */
#if defined(MBEDTLS_SSL_RENEGOTIATION)
ssl_write_renegotiation_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
ssl_write_signature_algorithms_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(MBEDTLS_USE_TINYCRYPT) || \
defined(MBEDTLS_ECDH_C) || \
defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_USE_TINYCRYPT) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
if( uses_ec )
{
ssl_write_supported_elliptic_curves_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
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_DTLS_CONNECTION_ID)
ssl_write_cid_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
#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_TRUNCATED_HMAC)
ssl_write_truncated_hmac_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
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_ALPN)
ssl_write_alpn_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
/* olen unused if all extensions are disabled */
((void) olen);
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, total extension length: %d",
ext_len ) );
if( ext_len > 0 )
{
p = mbedtls_platform_put_uint16_be( p, ext_len );
p += ext_len;
}
ssl->out_msglen = p - buf;
ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = MBEDTLS_SSL_HS_CLIENT_HELLO;
ssl->state = MBEDTLS_SSL_SERVER_HELLO;
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) )
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( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) )
{
#if defined(MBEDTLS_SSL_IMMEDIATE_TRANSMISSION)
mbedtls_ssl_immediate_flight_done( ssl );
#else
if( ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_flight_transmit", ret );
return( ret );
}
#endif
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write client hello" ) );
return( 0 );
}
static int ssl_parse_renegotiation_info( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
{
/* Check verify-data in constant-time. The length OTOH is no secret */
if( len != 1 + ssl->verify_data_len * 2 ||
buf[0] != ssl->verify_data_len * 2 ||
mbedtls_platform_memequal( buf + 1,
ssl->own_verify_data, ssl->verify_data_len ) != 0 ||
mbedtls_platform_memequal( buf + 1 + ssl->verify_data_len,
ssl->peer_verify_data, ssl->verify_data_len ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching renegotiation info" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
}
else
#endif /* MBEDTLS_SSL_RENEGOTIATION */
{
if( len != 1 || buf[0] != 0x00 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-zero length renegotiation info" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
}
return( 0 );
}
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
static int ssl_parse_max_fragment_length_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
/*
* server should use the extension only if we did,
* and if so the server's value should match ours (and len is always 1)
*/
if( ssl->conf->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE ||
len != 1 ||
buf[0] != ssl->conf->mfl_code )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching max fragment length extension" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
return( 0 );
}
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
static int ssl_parse_truncated_hmac_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED ||
len != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching truncated HMAC extension" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
ssl->session_negotiate->trunc_hmac = MBEDTLS_SSL_TRUNC_HMAC_ENABLED;
return( 0 );
}
#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
static int ssl_parse_cid_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
size_t peer_cid_len;
if( /* CID extension only makes sense in DTLS */
MBEDTLS_SSL_TRANSPORT_IS_TLS( ssl->conf->transport ) ||
/* The server must only send the CID extension if we have offered it. */
ssl->negotiate_cid == MBEDTLS_SSL_CID_DISABLED )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "CID extension unexpected" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
if( len == 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "CID extension invalid" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
peer_cid_len = *buf++;
len--;
if( peer_cid_len > MBEDTLS_SSL_CID_OUT_LEN_MAX )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "CID extension invalid" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
if( len != peer_cid_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "CID extension invalid" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
ssl->handshake->cid_in_use = MBEDTLS_SSL_CID_ENABLED;
ssl->handshake->peer_cid_len = (uint8_t) peer_cid_len;
/* Not using more secure mbedtls_platform_memcpy as peer_cid is public */
memcpy( ssl->handshake->peer_cid, buf, peer_cid_len );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Use of CID extension negotiated" ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "Server CID", buf, peer_cid_len );
return( 0 );
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
static int ssl_parse_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
mbedtls_ssl_get_minor_ver( ssl ) == MBEDTLS_SSL_MINOR_VERSION_0 ||
len != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching encrypt-then-MAC extension" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
ssl->session_negotiate->encrypt_then_mac = MBEDTLS_SSL_ETM_ENABLED;
return( 0 );
}
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
static int ssl_parse_extended_ms_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
if( mbedtls_ssl_conf_get_ems( ssl->conf ) ==
MBEDTLS_SSL_EXTENDED_MS_DISABLED ||
mbedtls_ssl_get_minor_ver( ssl ) == MBEDTLS_SSL_MINOR_VERSION_0 ||
len != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching extended master secret extension" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
return( 0 );
}
#endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
static int ssl_parse_session_ticket_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
if( ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED ||
len != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching session ticket extension" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
ssl->handshake->new_session_ticket = 1;
return( 0 );
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_ECDH_C) || \
defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) || \
defined(MBEDTLS_USE_TINYCRYPT)
static int ssl_parse_supported_point_formats_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
size_t list_size;
const unsigned char *p;
if( len == 0 || (size_t)( buf[0] + 1 ) != len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
list_size = buf[0];
p = buf + 1;
while( list_size > 0 )
{
if( p[0] == MBEDTLS_SSL_EC_PF_UNCOMPRESSED ||
p[0] == MBEDTLS_SSL_EC_PF_COMPRESSED )
{
#if defined(MBEDTLS_ECDH_C)
ssl->handshake->ecdh_ctx.point_format = p[0];
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
ssl->handshake->ecjpake_ctx.point_format = p[0];
#endif
MBEDTLS_SSL_DEBUG_MSG( 4, ( "point format selected: %d", p[0] ) );
return( 0 );
}
list_size--;
p++;
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "no point format in common" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C || MBEDTLS_USE_TINYCRYPT ||
MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
static int ssl_parse_ecjpake_kkpp( mbedtls_ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
int ret;
if( mbedtls_ssl_suite_get_key_exchange(
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake ) )
!= MBEDTLS_KEY_EXCHANGE_ECJPAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip ecjpake kkpp extension" ) );
return( 0 );
}
/* If we got here, we no longer need our cached extension */
mbedtls_free( ssl->handshake->ecjpake_cache );
ssl->handshake->ecjpake_cache = NULL;
ssl->handshake->ecjpake_cache_len = 0;
if( ( ret = mbedtls_ecjpake_read_round_one( &ssl->handshake->ecjpake_ctx,
buf, len ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_one", ret );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( ret );
}
return( 0 );
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_SSL_ALPN)
static int ssl_parse_alpn_ext( mbedtls_ssl_context *ssl,
const unsigned char *buf, size_t len )
{
size_t list_len, name_len;
const char **p;
/* If we didn't send it, the server shouldn't send it */
if( ssl->conf->alpn_list == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching ALPN extension" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/*
* opaque ProtocolName<1..2^8-1>;
*
* struct {
* ProtocolName protocol_name_list<2..2^16-1>
* } ProtocolNameList;
*
* the "ProtocolNameList" MUST contain exactly one "ProtocolName"
*/
/* Min length is 2 (list_len) + 1 (name_len) + 1 (name) */
if( len < 4 )
{
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
list_len = mbedtls_platform_get_uint16_be( buf );
if( list_len != len - 2 )
{
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
name_len = buf[2];
if( name_len != list_len - 1 )
{
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/* Check that the server chosen protocol was in our list and save it */
for( p = ssl->conf->alpn_list; *p != NULL; p++ )
{
if( name_len == strlen( *p ) &&
mbedtls_platform_memequal( buf + 3, *p, name_len ) == 0 )
{
ssl->alpn_chosen = *p;
return( 0 );
}
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "ALPN extension: no matching protocol" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
#endif /* MBEDTLS_SSL_ALPN */
/*
* Parse HelloVerifyRequest. Only called after verifying the HS type.
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
static int ssl_parse_hello_verify_request( mbedtls_ssl_context *ssl )
{
const unsigned char *p = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
int major_ver, minor_ver;
unsigned char cookie_len;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse hello verify request" ) );
/* Check that there is enough room for:
* - 2 bytes of version
* - 1 byte of cookie_len
*/
if( mbedtls_ssl_hs_hdr_len( ssl ) + 3 > ssl->in_msglen )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "incoming HelloVerifyRequest message is too short" ) );
mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/*
* struct {
* ProtocolVersion server_version;
* opaque cookie<0..2^8-1>;
* } HelloVerifyRequest;
*/
MBEDTLS_SSL_DEBUG_BUF( 3, "server version", p, 2 );
mbedtls_ssl_read_version( &major_ver, &minor_ver,
mbedtls_ssl_conf_get_transport( ssl->conf ), p );
p += 2;
/*
* Since the RFC is not clear on this point, accept DTLS 1.0 (TLS 1.1)
* even is lower than our min version.
*/
if( mbedtls_ssl_ver_lt( major_ver, MBEDTLS_SSL_MAJOR_VERSION_3 ) ||
mbedtls_ssl_ver_lt( minor_ver, MBEDTLS_SSL_MINOR_VERSION_2 ) ||
mbedtls_ssl_ver_gt( major_ver,
mbedtls_ssl_conf_get_max_major_ver( ssl->conf ) ) ||
mbedtls_ssl_ver_gt( minor_ver,
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server version" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
}
cookie_len = *p++;
if( ( ssl->in_msg + ssl->in_msglen ) - p < cookie_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1,
( "cookie length does not match incoming message size" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "cookie", p, cookie_len );
mbedtls_free( ssl->handshake->verify_cookie );
ssl->handshake->verify_cookie = mbedtls_calloc( 1, cookie_len );
if( ssl->handshake->verify_cookie == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc failed (%d bytes)", cookie_len ) );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
mbedtls_platform_memcpy( ssl->handshake->verify_cookie, p, cookie_len );
ssl->handshake->verify_cookie_len = cookie_len;
/* Start over at ClientHello */
ssl->state = MBEDTLS_SSL_CLIENT_HELLO;
mbedtls_ssl_reset_checksum( ssl );
mbedtls_ssl_recv_flight_completed( ssl );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse hello verify request" ) );
return( 0 );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
static int ssl_parse_server_hello( mbedtls_ssl_context *ssl )
{
int ret, i;
size_t n;
size_t ext_len;
unsigned char *buf, *ext;
unsigned char comp;
#if defined(MBEDTLS_ZLIB_SUPPORT)
int accept_comp;
#endif
#if defined(MBEDTLS_SSL_RENEGOTIATION)
int renegotiation_info_seen = 0;
#endif
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
int extended_ms_seen = 0;
#endif
int handshake_failure = 0;
/* The ciphersuite chosen by the server. */
mbedtls_ssl_ciphersuite_handle_t server_suite_info;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server hello" ) );
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
/* No alert on a read error. */
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
buf = ssl->in_msg;
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
{
#if defined(MBEDTLS_SSL_RENEGOTIATION)
if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
{
ssl->renego_records_seen++;
if( ssl->conf->renego_max_records >= 0 &&
ssl->renego_records_seen > ssl->conf->renego_max_records )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation requested, "
"but not honored by server" ) );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-handshake message during renego" ) );
ssl->keep_current_message = 1;
return( MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO );
}
#endif /* MBEDTLS_SSL_RENEGOTIATION */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) )
{
if( buf[0] == MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "received hello verify request" ) );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello" ) );
return( ssl_parse_hello_verify_request( ssl ) );
}
else
{
/* We made it through the verification process */
mbedtls_free( ssl->handshake->verify_cookie );
ssl->handshake->verify_cookie = NULL;
ssl->handshake->verify_cookie_len = 0;
}
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
if( ssl->in_hslen < 38 + mbedtls_ssl_hs_hdr_len( ssl ) ||
buf[0] != MBEDTLS_SSL_HS_SERVER_HELLO )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/*
* 0 . 1 server_version
* 2 . 33 random (maybe including 4 bytes of Unix time)
* 34 . 34 session_id length = n
* 35 . 34+n session_id
* 35+n . 36+n cipher_suite
* 37+n . 37+n compression_method
*
* 38+n . 39+n extensions length (optional)
* 40+n . .. extensions
*/
buf += mbedtls_ssl_hs_hdr_len( ssl );
{
int major_ver, minor_ver;
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, version", buf + 0, 2 );
mbedtls_ssl_read_version( &major_ver, &minor_ver,
mbedtls_ssl_conf_get_transport( ssl->conf ),
buf + 0 );
if( mbedtls_ssl_ver_lt( major_ver,
mbedtls_ssl_conf_get_min_major_ver( ssl->conf ) ) ||
mbedtls_ssl_ver_lt( minor_ver,
mbedtls_ssl_conf_get_min_minor_ver( ssl->conf ) ) ||
mbedtls_ssl_ver_gt( major_ver,
mbedtls_ssl_conf_get_max_major_ver( ssl->conf ) ) ||
mbedtls_ssl_ver_gt( minor_ver,
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "server version out of bounds - "
" min: [%d:%d], server: [%d:%d], max: [%d:%d]",
mbedtls_ssl_conf_get_min_major_ver( ssl->conf ),
mbedtls_ssl_conf_get_min_minor_ver( ssl->conf ),
major_ver, minor_ver,
mbedtls_ssl_conf_get_max_major_ver( ssl->conf ),
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
}
#if !defined(MBEDTLS_SSL_CONF_FIXED_MINOR_VER)
ssl->minor_ver = minor_ver;
#endif /* !MBEDTLS_SSL_CONF_FIXED_MINOR_VER */
#if !defined(MBEDTLS_SSL_CONF_FIXED_MAJOR_VER)
ssl->major_ver = major_ver;
#endif /* !MBEDTLS_SSL_CONF_FIXED_MAJOR_VER */
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu",
(unsigned long)mbedtls_platform_get_uint32_be( &buf[2] ) ) );
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_UNSET;
mbedtls_platform_memcpy( ssl->handshake->randbytes + 32, buf + 2, 32 );
if( mbedtls_platform_memequal( ssl->handshake->randbytes + 32, buf + 2, 32 ) == 0 )
{
ssl->handshake->hello_random_set = MBEDTLS_SSL_FI_FLAG_SET;
}
n = buf[34];
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 2, 32 );
if( n > 32 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
if( ssl->in_hslen > mbedtls_ssl_hs_hdr_len( ssl ) + 39 + n )
{
ext_len = mbedtls_platform_get_uint16_be( &buf[38 + n] );
if( ( ext_len > 0 && ext_len < 4 ) ||
ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) + 40 + n + ext_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
}
else if( ssl->in_hslen == mbedtls_ssl_hs_hdr_len( ssl ) + 38 + n )
{
ext_len = 0;
}
else
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
/* ciphersuite (used later) */
i = (int)mbedtls_platform_get_uint16_be( &buf[ 35 + n ] );
/*
* Read and check compression
*/
comp = buf[37 + n];
#if defined(MBEDTLS_ZLIB_SUPPORT)
/* See comments in ssl_write_client_hello() */
accept_comp = MBEDTLS_SSL_TRANSPORT_IS_TLS( ssl->conf->transport );
if( comp != MBEDTLS_SSL_COMPRESS_NULL &&
( comp != MBEDTLS_SSL_COMPRESS_DEFLATE || accept_comp == 0 ) )
#else /* MBEDTLS_ZLIB_SUPPORT */
if( comp != MBEDTLS_SSL_COMPRESS_NULL )
#endif/* MBEDTLS_ZLIB_SUPPORT */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "server hello, bad compression: %d", comp ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
}
/*
* Initialize update checksum functions
*/
server_suite_info = mbedtls_ssl_ciphersuite_from_id( i );
#if !defined(MBEDTLS_SSL_CONF_SINGLE_CIPHERSUITE)
ssl->handshake->ciphersuite_info = server_suite_info;
#endif
if( server_suite_info == MBEDTLS_SSL_CIPHERSUITE_INVALID_HANDLE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "ciphersuite info for %04x not found", i ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %d", n ) );
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, session id", buf + 35, n );
/*
* Check if the session can be resumed
*
* We're only resuming a session if it was requested (handshake->resume
* already set to 1 by mbedtls_ssl_set_session()), and further conditions
* are satisfied (not renegotiating, ID and ciphersuite match, etc).
*
* Update handshake->resume to the value it will keep for the rest of the
* handshake, and that will be used to determine the relative order
* client/server last flights, as well as in handshake_wrapup().
*/
#if !defined(MBEDTLS_SSL_NO_SESSION_RESUMPTION)
if( n == 0 ||
mbedtls_ssl_get_renego_status( ssl ) != MBEDTLS_SSL_INITIAL_HANDSHAKE ||
mbedtls_ssl_session_get_ciphersuite( ssl->session_negotiate ) != i ||
mbedtls_ssl_session_get_compression( ssl->session_negotiate ) != comp ||
ssl->session_negotiate->id_len != n ||
mbedtls_platform_memequal( ssl->session_negotiate->id, buf + 35, n ) != 0 )
{
ssl->handshake->resume = MBEDTLS_SSL_FI_FLAG_UNSET;
}
#endif /* !MBEDTLS_SSL_NO_SESSION_RESUMPTION */
if( mbedtls_ssl_handshake_get_resume( ssl->handshake ) == MBEDTLS_SSL_FI_FLAG_SET )
{
/* Resume a session */
ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC;
if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
return( ret );
}
}
else
{
/* Start a new session */
ssl->state = MBEDTLS_SSL_SERVER_CERTIFICATE;
#if defined(MBEDTLS_HAVE_TIME)
ssl->session_negotiate->start = mbedtls_time( NULL );
#endif
#if !defined(MBEDTLS_SSL_CONF_SINGLE_CIPHERSUITE)
ssl->session_negotiate->ciphersuite = i;
#endif /* MBEDTLS_SSL_CONF_SINGLE_CIPHERSUITE */
#if defined(MBEDTLS_ZLIB_SUPPORT)
ssl->session_negotiate->compression = comp;
#endif
ssl->session_negotiate->id_len = n;
/* Not using more secure mbedtls_platform_memcpy as id is public */
memcpy( ssl->session_negotiate->id, buf + 35, n );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "%s session has been resumed",
mbedtls_ssl_handshake_get_resume( ssl->handshake ) ? "a" : "no" ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %04x", i ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: %d", buf[37 + n] ) );
/*
* Perform cipher suite validation in same way as in ssl_write_client_hello.
*/
MBEDTLS_SSL_BEGIN_FOR_EACH_CIPHERSUITE( ssl,
mbedtls_ssl_get_minor_ver( ssl ),
ciphersuite_info )
{
if( ssl_validate_ciphersuite( ciphersuite_info, ssl,
mbedtls_ssl_conf_get_min_minor_ver( ssl->conf ),
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ) ) != 0 )
{
continue;
}
if( ciphersuite_info != server_suite_info )
continue;
goto server_picked_valid_suite;
}
MBEDTLS_SSL_END_FOR_EACH_CIPHERSUITE
/* If we reach this code-path, the server's chosen ciphersuite
* wasn't among those advertised by us. */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
server_picked_valid_suite:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %s",
mbedtls_ssl_suite_get_name( server_suite_info ) ) );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( mbedtls_ssl_suite_get_key_exchange( server_suite_info ) ==
MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA &&
mbedtls_ssl_get_minor_ver( ssl ) == MBEDTLS_SSL_MINOR_VERSION_3 )
{
ssl->handshake->ecrs_enabled = 1;
}
#endif
if( comp != MBEDTLS_SSL_COMPRESS_NULL
#if defined(MBEDTLS_ZLIB_SUPPORT)
&& comp != MBEDTLS_SSL_COMPRESS_DEFLATE
#endif
)
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
#if defined(MBEDTLS_ZLIB_SUPPORT)
ssl->session_negotiate->compression = comp;
#endif
ext = buf + 40 + n;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "server hello, total extension length: %d",
ext_len ) );
while( ext_len )
{
unsigned int ext_id = (unsigned int)
mbedtls_platform_get_uint16_be( ext );
unsigned int ext_size = (unsigned int)
mbedtls_platform_get_uint16_be( &ext[2] );
if( ext_size + 4 > ext_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
switch( ext_id )
{
case MBEDTLS_TLS_EXT_RENEGOTIATION_INFO:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) );
#if defined(MBEDTLS_SSL_RENEGOTIATION)
renegotiation_info_seen = 1;
#endif
if( ( ret = ssl_parse_renegotiation_info( ssl, ext + 4,
ext_size ) ) != 0 )
return( ret );
break;
#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
case MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found max_fragment_length extension" ) );
if( ( ret = ssl_parse_max_fragment_length_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
case MBEDTLS_TLS_EXT_TRUNCATED_HMAC:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found truncated_hmac extension" ) );
if( ( ret = ssl_parse_truncated_hmac_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
case MBEDTLS_TLS_EXT_CID:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found CID extension" ) );
if( ( ret = ssl_parse_cid_ext( ssl,
ext + 4,
ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
case MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found encrypt_then_mac extension" ) );
if( ( ret = ssl_parse_encrypt_then_mac_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
case MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found extended_master_secret extension" ) );
if( ( ret = ssl_parse_extended_ms_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
extended_ms_seen = 1;
break;
#endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
case MBEDTLS_TLS_EXT_SESSION_TICKET:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found session_ticket extension" ) );
if( ( ret = ssl_parse_session_ticket_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
#if defined(MBEDTLS_USE_TINYCRYPT) || \
defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
case MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found supported_point_formats extension" ) );
if( ( ret = ssl_parse_supported_point_formats_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
case MBEDTLS_TLS_EXT_ECJPAKE_KKPP:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found ecjpake_kkpp extension" ) );
if( ( ret = ssl_parse_ecjpake_kkpp( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
#if defined(MBEDTLS_SSL_ALPN)
case MBEDTLS_TLS_EXT_ALPN:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found alpn extension" ) );
if( ( ret = ssl_parse_alpn_ext( ssl, ext + 4, ext_size ) ) != 0 )
return( ret );
break;
#endif /* MBEDTLS_SSL_ALPN */
default:
MBEDTLS_SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)",
ext_id ) );
}
ext_len -= 4 + ext_size;
ext += 4 + ext_size;
if( ext_len > 0 && ext_len < 4 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
}
/*
* Renegotiation security checks
*/
if( ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
mbedtls_ssl_conf_get_allow_legacy_renegotiation( ssl->conf ) ==
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 &&
mbedtls_ssl_conf_get_allow_legacy_renegotiation( ssl->conf ) ==
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 */
/*
* Check if extended master secret is being enforced
*/
#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
if( mbedtls_ssl_conf_get_ems( ssl->conf ) ==
MBEDTLS_SSL_EXTENDED_MS_ENABLED )
{
if( extended_ms_seen )
{
#if !defined(MBEDTLS_SSL_EXTENDED_MS_ENFORCED)
ssl->handshake->extended_ms = MBEDTLS_SSL_EXTENDED_MS_ENABLED;
#endif /* !MBEDTLS_SSL_EXTENDED_MS_ENFORCED */
}
else if( mbedtls_ssl_conf_get_ems_enforced( ssl->conf ) ==
MBEDTLS_SSL_EXTENDED_MS_ENFORCE_ENABLED )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Peer not offering extended master "
"secret, while it is enforced") );
handshake_failure = 1;
}
}
#endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
if( handshake_failure == 1 )
{
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello" ) );
return( 0 );
}
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
static int ssl_parse_server_dh_params( mbedtls_ssl_context *ssl, unsigned char **p,
unsigned char *end )
{
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
/*
* Ephemeral DH parameters:
*
* struct {
* opaque dh_p<1..2^16-1>;
* opaque dh_g<1..2^16-1>;
* opaque dh_Ys<1..2^16-1>;
* } ServerDHParams;
*/
if( ( ret = mbedtls_dhm_read_params( &ssl->handshake->dhm_ctx, p, end ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 2, ( "mbedtls_dhm_read_params" ), ret );
return( ret );
}
if( ssl->handshake->dhm_ctx.len * 8 < ssl->conf->dhm_min_bitlen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "DHM prime too short: %d < %d",
ssl->handshake->dhm_ctx.len * 8,
ssl->conf->dhm_min_bitlen ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->handshake->dhm_ctx.P );
MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->handshake->dhm_ctx.G );
MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY );
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
#if defined(MBEDTLS_ECDH_C) && \
( defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) )
static int ssl_check_server_ecdh_params( const mbedtls_ssl_context *ssl )
{
const mbedtls_ecp_curve_info *curve_info;
mbedtls_ecp_group_id grp_id;
#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
grp_id = ssl->handshake->ecdh_ctx.grp.id;
#else
grp_id = ssl->handshake->ecdh_ctx.grp_id;
#endif
curve_info = mbedtls_ecp_curve_info_from_grp_id( grp_id );
if( curve_info == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "ECDH curve: %s", curve_info->name ) );
#if defined(MBEDTLS_ECP_C)
if( mbedtls_ssl_check_curve( ssl, grp_id ) != 0 )
#else
if( ssl->handshake->ecdh_ctx.grp.nbits < 163 ||
ssl->handshake->ecdh_ctx.grp.nbits > 521 )
#endif
return( -1 );
MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
MBEDTLS_DEBUG_ECDH_QP );
return( 0 );
}
#endif /* MBEDTLS_ECDH_C &&
( MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED ) */
#if defined(MBEDTLS_ECDH_C) && \
( defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED))
static int ssl_parse_server_ecdh_params( mbedtls_ssl_context *ssl,
unsigned char **p,
unsigned char *end )
{
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
/*
* Ephemeral ECDH parameters:
*
* struct {
* ECParameters curve_params;
* ECPoint public;
* } ServerECDHParams;
*/
if( ( ret = mbedtls_ecdh_read_params( &ssl->handshake->ecdh_ctx,
(const unsigned char **) p, end ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_read_params" ), ret );
return( ret );
}
if( ssl_check_server_ecdh_params( ssl ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message (ECDHE curve)" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
return( ret );
}
#endif /* MBEDTLS_ECDH_C &&
( MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED ) */
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
static int ssl_parse_server_psk_hint( mbedtls_ssl_context *ssl,
unsigned char **p,
unsigned char *end )
{
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
size_t len;
((void) ssl);
/*
* PSK parameters:
*
* opaque psk_identity_hint<0..2^16-1>;
*/
if( end - (*p) < 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message "
"(psk_identity_hint length)" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
len = mbedtls_platform_get_uint16_be( *p );
*p += 2;
if( end - (*p) < (int) len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message "
"(psk_identity_hint length)" ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
/*
* Note: we currently ignore the PKS identity hint, as we only allow one
* PSK to be provisionned on the client. This could be changed later if
* someone needs that feature.
*/
*p += len;
ret = 0;
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
/* This function assumes that `out` points to a writable buffer
* of size 48 Bytes if `add_length_tag == 0` and size 50 Bytes
* if `add_length_tag != 0`. */
static int ssl_rsa_generate_partial_pms( mbedtls_ssl_context *ssl,
unsigned char* out,
unsigned add_length_tag )
{
volatile int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
/*
* Generate (part of) the pre-master secret as
* struct {
* [ uint16 length(48) ]
* ProtocolVersion client_version;
* opaque random[46];
* } PreMasterSecret;
*/
if( add_length_tag )
{
out[0] = 0;
out[1] = 48;
out += 2;
}
mbedtls_ssl_write_version( mbedtls_ssl_conf_get_max_major_ver( ssl->conf ),
mbedtls_ssl_conf_get_max_minor_ver( ssl->conf ),
mbedtls_ssl_conf_get_transport( ssl->conf ), out );
ret = mbedtls_ssl_conf_get_frng( ssl->conf )
( mbedtls_ssl_conf_get_prng( ssl->conf ), out + 2, 46 );
if( ret == 0 )
{
mbedtls_platform_random_delay();
if( ret == 0 )
{
ssl->handshake->premaster_generated = MBEDTLS_SSL_FI_FLAG_SET;
return( 0 );
}
else
{
ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
}
}
MBEDTLS_SSL_DEBUG_RET( 1, "f_rng", ret );
return( ret );
}
/*
* Encrypt the randomly chosen part of the Premaster Secret with the
* server's RSA key and write it to the provided buffer.
*/
static int ssl_rsa_encrypt_partial_pms( mbedtls_ssl_context *ssl,
unsigned char const *ppms,
unsigned char *out, size_t buflen,
size_t *olen )
{
volatile int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
size_t len_bytes = mbedtls_ssl_get_minor_ver( ssl ) ==
MBEDTLS_SSL_MINOR_VERSION_0 ? 0 : 2;
mbedtls_pk_context *peer_pk = NULL;
if( buflen < len_bytes )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small for encrypted pms" ) );
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
}
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
if( ssl->handshake->got_peer_pubkey )
peer_pk = &ssl->handshake->peer_pubkey;
#else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
if( ssl->session_negotiate->peer_cert != NULL )
{
ret = mbedtls_x509_crt_pk_acquire( ssl->session_negotiate->peer_cert,
&peer_pk );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_x509_crt_pk_acquire", ret );
return( ret );
}
}
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
if( peer_pk == NULL )
{
/* Should never happen */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/*
* Encrypt the partial premaster secret and write it out.
*/
if( ! mbedtls_pk_can_do( peer_pk, MBEDTLS_PK_RSA ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "certificate key type mismatch" ) );
ret = MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH;
goto cleanup;
}
ret = mbedtls_pk_encrypt( peer_pk,
ppms, 48, out + len_bytes,
olen, buflen - len_bytes,
mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret == 0 )
{
mbedtls_platform_random_delay();
if( ret == 0 )
{
ssl->handshake->premaster_generated = MBEDTLS_SSL_FI_FLAG_SET;
}
else
{
ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_rsa_pkcs1_encrypt", ret );
goto cleanup;
}
}
else
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_rsa_pkcs1_encrypt", ret );
goto cleanup;
}
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( len_bytes == 2 )
{
(void)mbedtls_platform_put_uint16_be( out, *olen );
*olen += 2;
}
#endif
cleanup:
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
/* We don't need the peer's public key anymore. Free it. */
mbedtls_pk_free( peer_pk );
#else
mbedtls_x509_crt_pk_release( ssl->session_negotiate->peer_cert );
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
static int ssl_parse_signature_algorithm( mbedtls_ssl_context *ssl,
unsigned char **p,
unsigned char *end,
mbedtls_md_type_t *md_alg,
mbedtls_pk_type_t *pk_alg )
{
((void) ssl);
*md_alg = MBEDTLS_MD_NONE;
*pk_alg = MBEDTLS_PK_NONE;
/* Only in TLS 1.2 */
if( mbedtls_ssl_get_minor_ver( ssl ) != MBEDTLS_SSL_MINOR_VERSION_3 )
{
return( 0 );
}
if( (*p) + 2 > end )
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
/*
* Get hash algorithm
*/
if( ( *md_alg = mbedtls_ssl_md_alg_from_hash( (*p)[0] ) ) == MBEDTLS_MD_NONE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Server used unsupported "
"HashAlgorithm %d", *(p)[0] ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
/*
* Get signature algorithm
*/
if( ( *pk_alg = mbedtls_ssl_pk_alg_from_sig( (*p)[1] ) ) == MBEDTLS_PK_NONE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "server used unsupported "
"SignatureAlgorithm %d", (*p)[1] ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
/*
* Check if the hash is acceptable
*/
if( mbedtls_ssl_check_sig_hash( ssl, *md_alg ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "server used HashAlgorithm %d that was not offered",
*(p)[0] ) );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Server used SignatureAlgorithm %d", (*p)[1] ) );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Server used HashAlgorithm %d", (*p)[0] ) );
*p += 2;
return( 0 );
}
#endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
#if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl )
{
int ret;
mbedtls_pk_context * peer_pk;
/* Acquire peer's PK context: In case we store peer's entire
* certificate, we extract the context from it. Otherwise,
* we can use a temporary copy we've made for the purpose of
* signature verification. */
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
peer_pk = &ssl->handshake->peer_pubkey;
#else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
if( ssl->session_negotiate->peer_cert == NULL )
{
/* Should never happen */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
ret = mbedtls_x509_crt_pk_acquire( ssl->session_negotiate->peer_cert,
&peer_pk );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_x509_crt_pk_acquire", ret );
return( ret );
}
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
if( ! mbedtls_pk_can_do( peer_pk, MBEDTLS_PK_ECKEY ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) );
ret = MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH;
goto cleanup;
}
/* Extract ECDH parameters from peer's PK context. */
{
#if defined(MBEDTLS_USE_TINYCRYPT)
mbedtls_uecc_keypair *peer_key =
mbedtls_pk_uecc( *peer_pk );
mbedtls_platform_memcpy( ssl->handshake->ecdh_peerkey,
peer_key->public_key,
sizeof( ssl->handshake->ecdh_peerkey ) );
#else /* MBEDTLS_USE_TINYCRYPT */
const mbedtls_ecp_keypair *peer_key;
peer_key = mbedtls_pk_ec( *peer_pk );
if( ( ret = mbedtls_ecdh_get_params( &ssl->handshake->ecdh_ctx, peer_key,
MBEDTLS_ECDH_THEIRS ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_get_params" ), ret );
goto cleanup;
}
if( ssl_check_server_ecdh_params( ssl ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server certificate (ECDH curve)" ) );
ret = MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE;
goto cleanup;
}
#endif /* MBEDTLS_USE_TINYCRYPT */
}
cleanup:
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
/* We don't need the peer's public key anymore. Free it,
* so that more RAM is available for upcoming expensive
* operations like ECDHE. */
mbedtls_pk_free( peer_pk );
#else
mbedtls_x509_crt_pk_release( ssl->session_negotiate->peer_cert );
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
/*
*
* STATE HANDLING: ServerKeyExchange
*
*/
/*
* Overview
*/
/* Main entry point; orchestrates the other functions. */
static int ssl_process_in_server_key_exchange( mbedtls_ssl_context *ssl );
/* Coordination:
* Check if a ServerKeyExchange message is expected, and skip if not.
* Returns a negative code on failure, or
* - SSL_SRV_KEY_EXCHANGE_SKIP
* - SSL_SRV_KEY_EXCHANGE_EXPECTED
* indicating if a ServerKeyExchange message is expected or not.
*/
#define SSL_SRV_KEY_EXCHANGE_SKIP 0
#define SSL_SRV_KEY_EXCHANGE_EXPECTED 1
static int ssl_in_server_key_exchange_coordinate( mbedtls_ssl_context *ssl );
/* Preparation
* If applicable, prepare DH parameters from Server certificate. */
static int ssl_in_server_key_exchange_prepare( mbedtls_ssl_context *ssl );
/* Parse SrvKeyExchange message and store contents
* (PSK or DH parameters) in handshake structure. */
static int ssl_in_server_key_exchange_parse( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t buflen );
/* Update the handshake state */
static int ssl_in_server_key_exchange_postprocess( mbedtls_ssl_context *ssl );
/*
* Implementation
*/
static int ssl_in_server_key_exchange_prepare( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
((void) ciphersuite_info);
/* If applicable, extract static DH parameters from Server CRT. */
#if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info ) ==
MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info ) ==
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
{
int ret;
if( ( ret = ssl_get_ecdh_params_from_cert( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "ssl_get_ecdh_params_from_cert", ret );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
return( ret );
}
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
return( 0 );
}
static int ssl_in_server_key_exchange_coordinate( mbedtls_ssl_context *ssl )
{
int ret;
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
/* The ServerKeyExchange message is not used for
* - RSA or
* - static ECDH
* ciphersuites.
* It MAY be used in PSK or RSA-PSK.
*/
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info ) ==
MBEDTLS_KEY_EXCHANGE_RSA )
{
return( SSL_SRV_KEY_EXCHANGE_SKIP );
}
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info ) ==
MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info ) ==
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
{
return( SSL_SRV_KEY_EXCHANGE_SKIP );
}
#endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
/*
* ServerKeyExchange may be skipped with PSK and RSA-PSK when the server
* doesn't use a psk_identity_hint. Peek at next message to decide whether
* the ServerKeyExchange is being skipped or not.
*/
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA_PSK )
{
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
ssl->keep_current_message = 1;
if( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
ssl->in_msg[0] != MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE )
{
/* Current message is probably either
* CertificateRequest or ServerHelloDone */
return( SSL_SRV_KEY_EXCHANGE_SKIP );
}
}
return( SSL_SRV_KEY_EXCHANGE_EXPECTED );
}
static int ssl_in_server_key_exchange_parse( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t buflen )
{
/*
* Initialising to an error value would need a significant
* structural change to provide default flow assumes failure
*/
volatile int ret = 0;
volatile int ret_fi = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
unsigned char *p;
unsigned char *end;
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
p = buf + mbedtls_ssl_hs_hdr_len( ssl );
end = buf + buflen;
MBEDTLS_SSL_DEBUG_BUF( 3, "server key exchange", p, end - p );
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
{
if( ssl_parse_server_psk_hint( ssl, &p, end ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
} /* FALLTROUGH */
#endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA_PSK )
{
; /* nothing more to do */
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED ||
MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_DHE_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_DHE_PSK )
{
if( ssl_parse_server_dh_params( ssl, &p, end ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
#if defined(MBEDTLS_USE_TINYCRYPT)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA )
{
static const unsigned char ecdh_group[] = {
MBEDTLS_SSL_EC_TLS_NAMED_CURVE,
0 /* high bits of secp256r1 TLS ID */,
23 /* low bits of secp256r1 TLS ID */,
};
/* Check for fixed ECDH parameter preamble. */
if( (size_t)( end - p ) < sizeof( ecdh_group ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad server key exchange (too short)" ) );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
if( mbedtls_platform_memequal( p, ecdh_group, sizeof( ecdh_group ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Bad server key exchange (unexpected header)" ) );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
p += sizeof( ecdh_group );
/* Read server's key share. */
if( mbedtls_ssl_ecdh_read_peerkey( ssl, &p, end ) != 0 )
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
else
#endif /* MBEDTLS_USE_TINYCRYPT */
#if defined(MBEDTLS_ECDH_C) && \
( defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \
defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ) )
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA )
{
if( ssl_parse_server_ecdh_params( ssl, &p, end ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
}
else
#endif /* MBEDTLS_ECDH_C &&
( MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED ||
MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ) */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECJPAKE )
{
ret = mbedtls_ecjpake_read_round_two( &ssl->handshake->ecjpake_ctx,
p, end - p );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_two", ret );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
{
((void) ret);
((void) ret_fi);
((void) p);
((void) end);
((void) ciphersuite_info);
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED)
if( mbedtls_ssl_ciphersuite_uses_server_signature( ciphersuite_info ) )
{
size_t sig_len, hashlen;
unsigned char hash[64];
mbedtls_md_type_t md_alg = MBEDTLS_MD_NONE;
mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE;
unsigned char *params = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
size_t params_len = p - params;
void * volatile rs_ctx = NULL;
mbedtls_pk_context * peer_pk;
/*
* Handle the digitally-signed structure
*/
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( mbedtls_ssl_get_minor_ver( ssl ) == MBEDTLS_SSL_MINOR_VERSION_3 )
{
if( ssl_parse_signature_algorithm( ssl, &p, end,
&md_alg, &pk_alg ) != 0 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
if( pk_alg != mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
}
else
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
if( mbedtls_ssl_ver_lt( mbedtls_ssl_get_minor_ver( ssl ),
MBEDTLS_SSL_MINOR_VERSION_3 ) )
{
pk_alg = mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info );
/* Default hash for ECDSA is SHA-1 */
if( pk_alg == MBEDTLS_PK_ECDSA && md_alg == MBEDTLS_MD_NONE )
md_alg = MBEDTLS_MD_SHA1;
}
else
#endif
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
/*
* Read signature
*/
if( p > end - 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
sig_len = mbedtls_platform_get_uint16_be( p );
p += 2;
if( p != end - sig_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "signature", p, sig_len );
/*
* Compute the hash that has been signed
*/
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
if( md_alg == MBEDTLS_MD_NONE )
{
hashlen = 36;
ret = mbedtls_ssl_get_key_exchange_md_ssl_tls( ssl, hash, params,
params_len );
if( ret != 0 )
return( ret );
}
else
#endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \
MBEDTLS_SSL_PROTO_TLS1_1 */
#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( md_alg != MBEDTLS_MD_NONE )
{
ret = mbedtls_ssl_get_key_exchange_md_tls1_2( ssl, hash, &hashlen,
params, params_len,
md_alg );
if( ret != 0 )
return( ret );
}
else
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
MBEDTLS_SSL_PROTO_TLS1_2 */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen );
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
peer_pk = &ssl->handshake->peer_pubkey;
#else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
if( ssl->session_negotiate->peer_cert == NULL )
{
/* Should never happen */
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
ret = mbedtls_x509_crt_pk_acquire( ssl->session_negotiate->peer_cert,
&peer_pk );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_x509_crt_pk_acquire", ret );
return( ret );
}
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
/*
* Verify signature
*/
if( !mbedtls_pk_can_do( peer_pk, pk_alg ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
mbedtls_x509_crt_pk_release( ssl->session_negotiate->peer_cert );
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
}
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled )
rs_ctx = &ssl->handshake->ecrs_ctx.pk;
#endif
ret = mbedtls_pk_verify_restartable( peer_pk,
md_alg, hash, hashlen, p, sig_len, rs_ctx );
if( ret == 0 )
{
mbedtls_platform_random_delay();
if( rs_ctx == NULL )
{
ret_fi = mbedtls_pk_verify_restartable( peer_pk,
md_alg, hash, hashlen, p, sig_len, rs_ctx );
}
else
{
ret_fi = 0;
}
if( ret == 0 && ret_fi == 0 )
{
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
/* We don't need the peer's public key anymore. Free it,
* so that more RAM is available for upcoming expensive
* operations like ECDHE. */
mbedtls_pk_free( peer_pk );
#else
mbedtls_x509_crt_pk_release(
ssl->session_negotiate->peer_cert );
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
return( ret );
}
else
{
return( MBEDTLS_ERR_PLATFORM_FAULT_DETECTED );
}
}
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ret != MBEDTLS_ERR_ECP_IN_PROGRESS )
#endif
{
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECRYPT_ERROR );
}
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_verify", ret );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS;
#endif
#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
mbedtls_x509_crt_pk_release( ssl->session_negotiate->peer_cert );
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
}
#endif /* MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED */
return( ret );
}
static int ssl_in_server_key_exchange_postprocess( mbedtls_ssl_context *ssl )
{
ssl->state = MBEDTLS_SSL_CERTIFICATE_REQUEST;
return( 0 );
}
static int ssl_process_in_server_key_exchange( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server key exchange" ) );
/* Preparation:
* Potentially extract DH parameters from Server's certificate.
*
* Consider: Why don't we do this as post-processing after
* the server certificate has been read?
*/
MBEDTLS_SSL_CHK( ssl_in_server_key_exchange_prepare( ssl ) );
/* Coordination:
* Check if we expect a ServerKeyExchange */
MBEDTLS_SSL_CHK( ssl_in_server_key_exchange_coordinate( ssl ) );
if( ret == SSL_SRV_KEY_EXCHANGE_EXPECTED )
{
/* Reading step */
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ||
ssl->in_msg[0] != MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
ret = MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE;
goto cleanup;
}
else
{
MBEDTLS_SSL_CHK( ssl_in_server_key_exchange_parse( ssl, ssl->in_msg,
ssl->in_hslen ) );
}
}
else if( ret == SSL_SRV_KEY_EXCHANGE_SKIP )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) );
}
/* Update state */
MBEDTLS_SSL_CHK( ssl_in_server_key_exchange_postprocess( ssl ) );
cleanup:
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ret == MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS )
ssl->keep_current_message = 1;
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server key exchange" ) );
return( ret );
}
#if ! defined(MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED)
static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
if( ! mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
ssl->state = MBEDTLS_SSL_SERVER_HELLO_DONE;
return( 0 );
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#else /* MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
static int ssl_parse_certificate_request( mbedtls_ssl_context *ssl )
{
int ret;
unsigned char *buf;
size_t n = 0;
size_t cert_type_len = 0, dn_len = 0;
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
if( ! mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
ssl->state = MBEDTLS_SSL_SERVER_HELLO_DONE;
return( 0 );
}
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
ssl->state = MBEDTLS_SSL_SERVER_HELLO_DONE;
ssl->client_auth = ( ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE_REQUEST );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "got %s certificate request",
ssl->client_auth ? "a" : "no" ) );
if( ssl->client_auth == 0 )
{
/* Current message is probably the ServerHelloDone */
ssl->keep_current_message = 1;
goto exit;
}
/*
* struct {
* ClientCertificateType certificate_types<1..2^8-1>;
* SignatureAndHashAlgorithm
* supported_signature_algorithms<2^16-1>; -- TLS 1.2 only
* DistinguishedName certificate_authorities<0..2^16-1>;
* } CertificateRequest;
*
* Since we only support a single certificate on clients, let's just
* ignore all the information that's supposed to help us pick a
* certificate.
*
* We could check that our certificate matches the request, and bail out
* if it doesn't, but it's simpler to just send the certificate anyway,
* and give the server the opportunity to decide if it should terminate
* the connection when it doesn't like our certificate.
*
* Same goes for the hash in TLS 1.2's signature_algorithms: at this
* point we only have one hash available (see comments in
* write_certificate_verify), so let's just use what we have.
*
* However, we still minimally parse the message to check it is at least
* superficially sane.
*/
buf = ssl->in_msg;
/* certificate_types */
if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
cert_type_len = buf[mbedtls_ssl_hs_hdr_len( ssl )];
n = cert_type_len;
/*
* In the subsequent code there are two paths that read from buf:
* * the length of the signature algorithms field (if minor version of
* SSL is 3),
* * distinguished name length otherwise.
* Both reach at most the index:
* ...hdr_len + 2 + n,
* therefore the buffer length at this point must be greater than that
* regardless of the actual code path.
*/
if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) + 2 + n )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
/* supported_signature_algorithms */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( mbedtls_ssl_get_minor_ver( ssl ) == MBEDTLS_SSL_MINOR_VERSION_3 )
{
size_t sig_alg_len = mbedtls_platform_get_uint16_be( &buf[mbedtls_ssl_hs_hdr_len( ssl ) + 1 + n] );
#if defined(MBEDTLS_DEBUG_C)
unsigned char* sig_alg;
size_t i;
#endif
/*
* The furthest access in buf is in the loop few lines below:
* sig_alg[i + 1],
* where:
* sig_alg = buf + ...hdr_len + 3 + n,
* max(i) = sig_alg_len - 1.
* Therefore the furthest access is:
* buf[...hdr_len + 3 + n + sig_alg_len - 1 + 1],
* which reduces to:
* buf[...hdr_len + 3 + n + sig_alg_len],
* which is one less than we need the buf to be.
*/
if( ssl->in_hslen <= mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n + sig_alg_len )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
#if defined(MBEDTLS_DEBUG_C)
sig_alg = buf + mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n;
for( i = 0; i < sig_alg_len; i += 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Supported Signature Algorithm found: %d"
",%d", sig_alg[i], sig_alg[i + 1] ) );
}
#endif
n += 2 + sig_alg_len;
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
/* certificate_authorities */
dn_len = mbedtls_platform_get_uint16_be( &buf[mbedtls_ssl_hs_hdr_len( ssl ) + 1 + n] );
n += dn_len;
if( ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) + 3 + n )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST );
}
exit:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate request" ) );
return( 0 );
}
#endif /* MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
static int ssl_parse_server_hello_done( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server hello done" ) );
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello done message" ) );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
if( ssl->in_hslen != mbedtls_ssl_hs_hdr_len( ssl ) ||
ssl->in_msg[0] != MBEDTLS_SSL_HS_SERVER_HELLO_DONE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server hello done message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO_DONE );
}
ssl->state = MBEDTLS_SSL_CLIENT_CERTIFICATE;
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) )
mbedtls_ssl_recv_flight_completed( ssl );
#endif
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse server hello done" ) );
return( ret );
}
/*
*
* STATE HANDLING: Client Key Exchange
*
*/
/*
* Overview
*/
/* Main entry point; orchestrates the other functions */
static int ssl_process_out_client_key_exchange( mbedtls_ssl_context *ssl );
/* Preparation
* - For ECDH: Generate client params and derive premaster secret
* - For RSA-suites: Encrypt PMS
* - For ECJPAKE: Do Round 2
*/
static int ssl_out_client_key_exchange_prepare( mbedtls_ssl_context *ssl );
static int ssl_out_client_key_exchange_write( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t buflen,
size_t *olen );
static int ssl_out_client_key_exchange_postprocess( mbedtls_ssl_context *ssl );
/*
* Implementation
*/
static int ssl_process_out_client_key_exchange( mbedtls_ssl_context *ssl )
{
int ret = 0;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> process client key exchange" ) );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_state == ssl_ecrs_cke_ecdh_calc_secret )
goto cli_key_exchange_postprocess;
if( ssl->handshake->ecrs_enabled )
mbedtls_ecdh_enable_restart( &ssl->handshake->ecdh_ctx );
#endif
MBEDTLS_SSL_CHK( ssl_out_client_key_exchange_prepare( ssl ) );
/* Prepare CertificateVerify message in output buffer. */
MBEDTLS_SSL_CHK( ssl_out_client_key_exchange_write( ssl, ssl->out_msg,
MBEDTLS_SSL_MAX_CONTENT_LEN,
&ssl->out_msglen ) );
ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE;
/* Calculate secrets and update state */
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled )
ssl->handshake->ecrs_state = ssl_ecrs_cke_ecdh_calc_secret;
cli_key_exchange_postprocess:
#endif
ret = ssl_out_client_key_exchange_postprocess( ssl );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS;
#endif /* MBEDTLS_SSL__ECP_RESTARTABLE */
MBEDTLS_SSL_CHK( ret );
/* Dispatch message */
MBEDTLS_SSL_CHK( mbedtls_ssl_write_handshake_msg( ssl ) );
/* NOTE: For the new messaging layer, the postprocessing step
* might come after the dispatching step if the latter
* doesn't send the message immediately.
* At the moment, we must do the postprocessing
* prior to the dispatching because if the latter
* returns WANT_WRITE, we want the handshake state
* to be updated in order to not enter
* this function again on retry. */
cleanup:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= process client key exchange" ) );
return( ret );
}
static int ssl_out_client_key_exchange_prepare( mbedtls_ssl_context *ssl )
{
int ret = 0;
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
((void) ret);
((void) ciphersuite_info);
/* TODO: The current API for DH and ECDH does not allow
* to separate public key generation from public key export.
*
* Ideally, we would like to pick the private (EC)DH keys
* in this preparation step, exporting the corresponding
* public key in the writing step only.
*
* The necessary extension of the (EC)DH API is being
* considered, but until then we perform the public
* generation + export in the writing step.
*
*/
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA_PSK )
{
/* For RSA-PSK, the premaster secret is composed of
* - Length tag with value 48, encoded as a uint16
* - 2 bytes indicating the TLS version
* - 46 randomly chosen bytes
* - the chosen PSK.
* The following call takes care of all but the PSK. */
ret = ssl_rsa_generate_partial_pms( ssl, ssl->handshake->premaster,
1 /* Add length tag */ );
if( ret != 0 )
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA )
{
/* For RSA, the premaster secret is composed of
* - 2 bytes indicating the TLS version
* - 46 randomly chosen bytes
* which the following call generates. */
ret = ssl_rsa_generate_partial_pms( ssl, ssl->handshake->premaster,
0 /* Omit length tag */ );
if( ret != 0 )
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
return( 0 );
}
/* Warning: Despite accepting a length argument, this function is currently
* still lacking some bounds checks and assumes that `buf` has length
* `MBEDTLS_SSL_OUT_CONTENT_LEN`. Eventually, it should be rewritten to work
* with any buffer + length pair, returning MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL
* on insufficient writing space. */
static int ssl_out_client_key_exchange_write( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t buflen,
size_t *olen )
{
int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
unsigned char *p, *end;
size_t n;
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
/* NOTE: This function will generate different messages
* when it's called multiple times, because it currently
* includes private/public key generation in case of
* (EC)DH ciphersuites.
*
* It is therefore not suitable to be registered as a callback
* for retransmission, if such get introduced at some point.
*
* Also see the documentation of ssl_out_client_key_exchange_prepare().
*/
p = buf + 4;
end = buf + buflen;
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_DHE_RSA )
{
/*
* DHM key exchange -- send G^X mod P
*/
n = ssl->handshake->dhm_ctx.len;
if( (size_t)( end - p ) < n + 2 )
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
p = mbedtls_platform_put_uint16_be( p, n );
ret = mbedtls_dhm_make_public( &ssl->handshake->dhm_ctx,
(int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ),
p, n, mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_make_public", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: X ", &ssl->handshake->dhm_ctx.X );
MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GX", &ssl->handshake->dhm_ctx.GX );
p += n;
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED */
#if defined(MBEDTLS_USE_TINYCRYPT)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
{
((void) n);
((void) ret);
if( (size_t)( end - p ) < 2 * NUM_ECC_BYTES + 2 )
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
*p++ = 2 * NUM_ECC_BYTES + 1;
*p++ = 0x04; /* uncompressed point presentation */
#if defined(MBEDTLS_SSL_EARLY_KEY_COMPUTATION)
mbedtls_platform_memcpy( p, ssl->handshake->ecdh_publickey,
2 * NUM_ECC_BYTES );
#else
ret = uECC_make_key( p, ssl->handshake->ecdh_privkey );
if( ret == UECC_FAULT_DETECTED )
return( MBEDTLS_ERR_PLATFORM_FAULT_DETECTED );
if( ret != UECC_SUCCESS )
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
#endif /* MBEDTLS_SSL_EARLY_KEY_COMPUTATION && MBEDTLS_USE_TINYCRYPT */
p += 2 * NUM_ECC_BYTES;
}
else
#endif /* MBEDTLS_USE_TINYCRYPT */
#if defined(MBEDTLS_ECDH_C) && \
( 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( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
{
/*
* ECDH key exchange -- generate and send client public value
*/
/* NOTE: If we ever switch the ECDH stack/API to allow
* independent key generation and export, we should have
* generated our key share in the preparation step, and
* we'd only do the export here. */
ret = mbedtls_ecdh_make_public( &ssl->handshake->ecdh_ctx,
&n, p, end - p,
mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_make_public", ret );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS;
#endif
return( ret );
}
MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
MBEDTLS_DEBUG_ECDH_Q );
p += n;
}
else
#endif /* MBEDTLS_ECDH_C && (
( 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__SOME__PSK_ENABLED)
if( mbedtls_ssl_ciphersuite_uses_psk( ciphersuite_info ) )
{
/*
* opaque psk_identity<0..2^16-1>;
*/
if( ssl->conf->psk == NULL || ssl->conf->psk_identity == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no private key for PSK" ) );
return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
}
n = ssl->conf->psk_identity_len;
if( buflen < n + 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "psk identity too long or "
"SSL buffer too short" ) );
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
}
p = mbedtls_platform_put_uint16_be( p, n );
mbedtls_platform_memcpy( p, ssl->conf->psk_identity, n );
p += ssl->conf->psk_identity_len;
#if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_PSK )
{
((void) ret);
((void) end);
}
else
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA_PSK )
{
if( ( ret = ssl_rsa_encrypt_partial_pms( ssl,
ssl->handshake->premaster + 2,
p, end - p, &n ) ) != 0 )
return( ret );
p += n;
}
else
#endif
#if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_DHE_PSK )
{
/*
* ClientDiffieHellmanPublic public (DHM send G^X mod P)
*/
((void) end);
n = ssl->handshake->dhm_ctx.len;
if( buflen < n + 2 )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "psk identity or DHM size too long"
" or SSL buffer too short" ) );
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
}
p = mbedtls_platform_put_uint16_be( p, n );
ret = mbedtls_dhm_make_public( &ssl->handshake->dhm_ctx,
(int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ),
p, n, mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_make_public", ret );
return( ret );
}
p += n;
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
{
#if defined(MBEDTLS_USE_TINYCRYPT)
((void) n);
if( (size_t)( end - p ) < 2 * NUM_ECC_BYTES + 2 )
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
*p++ = 2 * NUM_ECC_BYTES + 1;
*p++ = 0x04; /* uncompressed point presentation */
ret = uECC_make_key( p, ssl->handshake->ecdh_privkey );
if( ret == UECC_FAULT_DETECTED )
return( MBEDTLS_ERR_PLATFORM_FAULT_DETECTED );
if( ret != UECC_SUCCESS )
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
p += 2 * NUM_ECC_BYTES;
#else /* MBEDTLS_USE_TINYCRYPT */
/*
* ClientECDiffieHellmanPublic public;
*/
ret = mbedtls_ecdh_make_public( &ssl->handshake->ecdh_ctx, &n,
p, buflen,
mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_make_public", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Q", &ssl->handshake->ecdh_ctx.Q );
p += n;
#endif /* MBEDTLS_USE_TINYCRYPT */
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
}
else
#endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_RSA )
{
if( ( ret = ssl_rsa_encrypt_partial_pms( ssl, ssl->handshake->premaster,
p, end - p, &n ) ) != 0 )
return( ret );
p += n;
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
if( mbedtls_ssl_suite_get_key_exchange( ciphersuite_info )
== MBEDTLS_KEY_EXCHANGE_ECJPAKE )
{
ret = mbedtls_ecjpake_write_round_two( &ssl->handshake->ecjpake_ctx,
p, end - p, &n,
mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ) );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_write_round_two", ret );
return( ret );
}
p += n;
}
else
#endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
{
((void) ciphersuite_info);
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
*olen = p - buf;
return( 0 );
}
static int ssl_out_client_key_exchange_postprocess( mbedtls_ssl_context *ssl )
{
int ret;
if( ( ret = mbedtls_ssl_build_pms( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_build_pms", ret );
return( ret );
}
ssl->state = MBEDTLS_SSL_CERTIFICATE_VERIFY;
return( 0 );
}
#if !defined(MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED)
static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
{
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
int ret;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) );
if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
return( ret );
}
if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
ssl->state = MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC;
return( 0 );
}
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#else /* !MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
static int ssl_write_certificate_verify( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
mbedtls_ssl_ciphersuite_handle_t ciphersuite_info =
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake );
size_t n = 0, offset = 0;
unsigned char hash[48];
unsigned char *hash_start = hash;
mbedtls_md_type_t md_alg = MBEDTLS_MD_NONE;
size_t hashlen;
void *rs_ctx = NULL;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled &&
ssl->handshake->ecrs_state == ssl_ecrs_crt_vrfy_sign )
{
goto sign;
}
#endif
if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
return( ret );
}
if( !mbedtls_ssl_ciphersuite_cert_req_allowed( ciphersuite_info ) )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
ssl->state = MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC;
return( 0 );
}
if( ssl->client_auth == 0 || mbedtls_ssl_own_cert( ssl ) == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) );
ssl->state = MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC;
return( 0 );
}
if( mbedtls_ssl_own_key( ssl ) == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no private key for certificate" ) );
return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
}
/*
* Make a signature of the handshake digests
*/
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled )
ssl->handshake->ecrs_state = ssl_ecrs_crt_vrfy_sign;
sign:
#endif
mbedtls_ssl_calc_verify(
mbedtls_ssl_get_minor_ver( ssl ),
mbedtls_ssl_suite_get_mac( ciphersuite_info ),
ssl, hash, &hashlen );
#if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
defined(MBEDTLS_SSL_PROTO_TLS1_1)
if( mbedtls_ssl_get_minor_ver( ssl ) != MBEDTLS_SSL_MINOR_VERSION_3 )
{
/*
* digitally-signed struct {
* opaque md5_hash[16];
* opaque sha_hash[20];
* };
*
* md5_hash
* MD5(handshake_messages);
*
* sha_hash
* SHA(handshake_messages);
*/
md_alg = MBEDTLS_MD_NONE;
/*
* For ECDSA, default hash is SHA-1 only
*/
if( mbedtls_pk_can_do( mbedtls_ssl_own_key( ssl ), MBEDTLS_PK_ECDSA ) )
{
hash_start += 16;
hashlen -= 16;
md_alg = MBEDTLS_MD_SHA1;
}
}
else
#endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \
MBEDTLS_SSL_PROTO_TLS1_1 */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
if( mbedtls_ssl_get_minor_ver( ssl ) == MBEDTLS_SSL_MINOR_VERSION_3 )
{
/*
* digitally-signed struct {
* opaque handshake_messages[handshake_messages_length];
* };
*
* Taking shortcut here. We assume that the server always allows the
* PRF Hash function and has sent it in the allowed signature
* algorithms list received in the Certificate Request message.
*
* Until we encounter a server that does not, we will take this
* shortcut.
*
* Reason: Otherwise we should have running hashes for SHA512 and SHA224
* in order to satisfy 'weird' needs from the server side.
*/
if( mbedtls_ssl_suite_get_mac(
mbedtls_ssl_handshake_get_ciphersuite( ssl->handshake ) )
== MBEDTLS_MD_SHA384 )
{
md_alg = MBEDTLS_MD_SHA384;
ssl->out_msg[4] = MBEDTLS_SSL_HASH_SHA384;
}
else
{
md_alg = MBEDTLS_MD_SHA256;
ssl->out_msg[4] = MBEDTLS_SSL_HASH_SHA256;
}
ssl->out_msg[5] = mbedtls_ssl_sig_from_pk( mbedtls_ssl_own_key( ssl ) );
/* Info from md_alg will be used instead */
hashlen = 0;
offset = 2;
}
else
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
}
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ssl->handshake->ecrs_enabled )
rs_ctx = &ssl->handshake->ecrs_ctx.pk;
#endif
if( ( ret = mbedtls_pk_sign_restartable( mbedtls_ssl_own_key( ssl ),
md_alg, hash_start, hashlen,
ssl->out_msg + 6 + offset, &n,
mbedtls_ssl_conf_get_frng( ssl->conf ),
mbedtls_ssl_conf_get_prng( ssl->conf ), rs_ctx ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_sign", ret );
#if defined(MBEDTLS_SSL__ECP_RESTARTABLE)
if( ret == MBEDTLS_ERR_ECP_IN_PROGRESS )
ret = MBEDTLS_ERR_SSL_CRYPTO_IN_PROGRESS;
#endif
return( ret );
}
(void)mbedtls_platform_put_uint16_be( &ssl->out_msg[4 + offset], n );
ssl->out_msglen = 6 + n + offset;
ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
ssl->out_msg[0] = MBEDTLS_SSL_HS_CERTIFICATE_VERIFY;
ssl->state = MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC;
if( ( ret = mbedtls_ssl_write_handshake_msg( ssl ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_handshake_msg", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write certificate verify" ) );
return( ret );
}
#endif /* MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
static int ssl_parse_new_session_ticket( mbedtls_ssl_context *ssl )
{
int ret;
uint32_t lifetime;
size_t ticket_len;
unsigned char *ticket;
const unsigned char *msg;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse new session ticket" ) );
if( ( ret = mbedtls_ssl_read_record( ssl, 1 ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
return( ret );
}
if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE );
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
}
/*
* struct {
* uint32 ticket_lifetime_hint;
* opaque ticket<0..2^16-1>;
* } NewSessionTicket;
*
* 0 . 3 ticket_lifetime_hint
* 4 . 5 ticket_len (n)
* 6 . 5+n ticket content
*/
if( ssl->in_msg[0] != MBEDTLS_SSL_HS_NEW_SESSION_TICKET ||
ssl->in_hslen < 6 + mbedtls_ssl_hs_hdr_len( ssl ) )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_NEW_SESSION_TICKET );
}
msg = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
lifetime = (uint32_t)mbedtls_platform_get_uint32_be( msg );
ticket_len = mbedtls_platform_get_uint16_be( &msg[4] );
if( ticket_len + 6 + mbedtls_ssl_hs_hdr_len( ssl ) != ssl->in_hslen )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
return( MBEDTLS_ERR_SSL_BAD_HS_NEW_SESSION_TICKET );
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket length: %d", ticket_len ) );
/* We're not waiting for a NewSessionTicket message any more */
ssl->handshake->new_session_ticket = 0;
ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC;
/*
* Zero-length ticket means the server changed his mind and doesn't want
* to send a ticket after all, so just forget it
*/
if( ticket_len == 0 )
return( 0 );
if( ssl->session != NULL && ssl->session->ticket != NULL )
{
mbedtls_platform_zeroize( ssl->session->ticket,
ssl->session->ticket_len );
mbedtls_free( ssl->session->ticket );
ssl->session->ticket = NULL;
ssl->session->ticket_len = 0;
}
mbedtls_platform_zeroize( ssl->session_negotiate->ticket,
ssl->session_negotiate->ticket_len );
mbedtls_free( ssl->session_negotiate->ticket );
ssl->session_negotiate->ticket = NULL;
ssl->session_negotiate->ticket_len = 0;
if( ( ticket = mbedtls_calloc( 1, ticket_len ) ) == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "ticket alloc failed" ) );
mbedtls_ssl_pend_fatal_alert( ssl,
MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
}
mbedtls_platform_memcpy( ticket, msg + 6, ticket_len );
ssl->session_negotiate->ticket = ticket;
ssl->session_negotiate->ticket_len = ticket_len;
ssl->session_negotiate->ticket_lifetime = lifetime;
/*
* RFC 5077 section 3.4:
* "If the client receives a session ticket from the server, then it
* discards any Session ID that was sent in the ServerHello."
*/
MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket in use, discarding session id" ) );
ssl->session_negotiate->id_len = 0;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse new session ticket" ) );
return( 0 );
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
/*
* SSL handshake -- client side -- single step
*/
int mbedtls_ssl_handshake_client_step( mbedtls_ssl_context *ssl )
{
int ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
#if defined(MBEDTLS_SSL_DELAYED_SERVER_CERT_VERIFICATION)
void *rs_ctx = NULL;
int authmode;
#endif /* MBEDTLS_SSL_DELAYED_SERVER_CERT_VERIFICATION */
if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER || ssl->handshake == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "client state: %d", ssl->state ) );
if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
return( ret );
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( MBEDTLS_SSL_TRANSPORT_IS_DTLS( ssl->conf->transport ) &&
ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING )
{
if( ( ret = mbedtls_ssl_flight_transmit( ssl ) ) != 0 )
return( ret );
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
/* Change state now, so that it is right in mbedtls_ssl_read_record(), used
* by DTLS for dropping out-of-sequence ChangeCipherSpec records */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
if( ssl->state == MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC &&
ssl->handshake->new_session_ticket != 0 )
{
ssl->state = MBEDTLS_SSL_SERVER_NEW_SESSION_TICKET;
}
#endif
ret = MBEDTLS_ERR_PLATFORM_FAULT_DETECTED;
switch( ssl->state )
{
case MBEDTLS_SSL_HELLO_REQUEST:
ssl->state = MBEDTLS_SSL_CLIENT_HELLO;
ret = 0;
break;
/*
* ==> ClientHello
*/
case MBEDTLS_SSL_CLIENT_HELLO:
ret = ssl_write_client_hello( ssl );
break;
/*
* <== ServerHello
* Certificate
* ( ServerKeyExchange )
* ( CertificateRequest )
* ServerHelloDone
*/
case MBEDTLS_SSL_SERVER_HELLO:
#if defined(MBEDTLS_SSL_EARLY_KEY_COMPUTATION) && defined(MBEDTLS_USE_TINYCRYPT)
{
volatile uint8_t ecdhe_computed = ssl->handshake->ecdhe_computed;
/* Make sure that the ECDHE pre-computation is only done once */
if( ecdhe_computed == 0 )
{
ret = uECC_make_key( ssl->handshake->ecdh_publickey, ssl->handshake->ecdh_privkey );
if( ret == UECC_FAULT_DETECTED )
return( MBEDTLS_ERR_PLATFORM_FAULT_DETECTED );
if( ret != UECC_SUCCESS )
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
ssl->handshake->ecdhe_computed = 1;
ecdhe_computed = 1;
}
if( ecdhe_computed == 0 || ssl->handshake->ecdhe_computed == 0 )
return( MBEDTLS_ERR_PLATFORM_FAULT_DETECTED );
}
#endif /* MBEDTLS_SSL_EARLY_KEY_COMPUTATION && MBEDTLS_USE_TINYCRYPT */
ret = ssl_parse_server_hello( ssl );
break;
case MBEDTLS_SSL_SERVER_CERTIFICATE:
ret = mbedtls_ssl_parse_certificate( ssl );
break;
case MBEDTLS_SSL_SERVER_KEY_EXCHANGE:
ret = ssl_process_in_server_key_exchange( ssl );
break;
case MBEDTLS_SSL_CERTIFICATE_REQUEST:
ret = ssl_parse_certificate_request( ssl );
break;
case MBEDTLS_SSL_SERVER_HELLO_DONE:
ret = ssl_parse_server_hello_done( ssl );
break;
/*
* ==> ( Certificate/Alert )
* ClientKeyExchange
* ( CertificateVerify )
* ChangeCipherSpec
* Finished
*/
case MBEDTLS_SSL_CLIENT_CERTIFICATE:
ret = mbedtls_ssl_write_certificate( ssl );
break;
case MBEDTLS_SSL_CLIENT_KEY_EXCHANGE:
ret = ssl_process_out_client_key_exchange( ssl );
break;
case MBEDTLS_SSL_CERTIFICATE_VERIFY:
ret = ssl_write_certificate_verify( ssl );
break;
case MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC:
ret = mbedtls_ssl_write_change_cipher_spec( ssl );
break;
case MBEDTLS_SSL_CLIENT_FINISHED:
#if defined(MBEDTLS_SSL_DELAYED_SERVER_CERT_VERIFICATION)
#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
authmode = ssl->handshake->sni_authmode != MBEDTLS_SSL_VERIFY_UNSET
? ssl->handshake->sni_authmode
: mbedtls_ssl_conf_get_authmode( ssl->conf );
#else
authmode = mbedtls_ssl_conf_get_authmode( ssl->conf );
#endif
MBEDTLS_SSL_DEBUG_MSG( 3, ( "execute delayed server certificate verification" ) );
ret = mbedtls_ssl_parse_delayed_certificate_verify( ssl, authmode,
ssl->session_negotiate->peer_cert, rs_ctx );
if( ret != 0 )
break;
#endif /* MBEDTLS_SSL_DELAYED_SERVER_CERT_VERIFICATION */
ret = mbedtls_ssl_write_finished( ssl );
break;
/*
* <== ( NewSessionTicket )
* ChangeCipherSpec
* Finished
*/
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
case MBEDTLS_SSL_SERVER_NEW_SESSION_TICKET:
ret = ssl_parse_new_session_ticket( ssl );
break;
#endif
case MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC:
ret = mbedtls_ssl_parse_change_cipher_spec( ssl );
break;
case MBEDTLS_SSL_SERVER_FINISHED:
ret = mbedtls_ssl_parse_finished( ssl );
break;
case MBEDTLS_SSL_FLUSH_BUFFERS:
MBEDTLS_SSL_DEBUG_MSG( 2, ( "handshake: done" ) );
ssl->state = MBEDTLS_SSL_HANDSHAKE_WRAPUP;
ret = 0;
break;
case MBEDTLS_SSL_HANDSHAKE_WRAPUP:
ret = mbedtls_ssl_handshake_wrapup( ssl );
break;
case MBEDTLS_SSL_INVALID:
default:
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) );
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
}
return( ret );
}
#endif /* MBEDTLS_SSL_CLI_C */
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