7840f81303
Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
2065 lines
67 KiB
C
2065 lines
67 KiB
C
/*
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* TLS 1.3 client-side functions
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*
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* Copyright The Mbed TLS Contributors
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may
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* not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* This file is part of mbed TLS ( https://tls.mbed.org )
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*/
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#include "common.h"
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#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
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#if defined(MBEDTLS_SSL_CLI_C)
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#include <string.h>
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#include "mbedtls/debug.h"
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#include "mbedtls/error.h"
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#include "mbedtls/platform.h"
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#include "ssl_misc.h"
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#include "ecdh_misc.h"
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#include "ssl_tls13_keys.h"
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#include "ssl_debug_helpers.h"
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/* Write extensions */
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/*
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* ssl_tls13_write_supported_versions_ext():
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*
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* struct {
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* ProtocolVersion versions<2..254>;
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* } SupportedVersions;
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*/
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static int ssl_tls13_write_supported_versions_ext( mbedtls_ssl_context *ssl,
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unsigned char *buf,
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unsigned char *end,
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size_t *out_len )
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{
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unsigned char *p = buf;
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*out_len = 0;
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MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported versions extension" ) );
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/* Check if we have space to write the extension:
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* - extension_type (2 bytes)
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* - extension_data_length (2 bytes)
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* - versions_length (1 byte )
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* - versions (2 bytes)
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*/
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MBEDTLS_SSL_CHK_BUF_PTR( p, end, 7 );
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/* Write extension_type */
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MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS, p, 0 );
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/* Write extension_data_length */
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MBEDTLS_PUT_UINT16_BE( 3, p, 2 );
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p += 4;
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/* Length of versions */
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*p++ = 0x2;
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/* Write values of supported versions.
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*
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* They are defined by the configuration.
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*
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* Currently, only one version is advertised.
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*/
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mbedtls_ssl_write_version( ssl->conf->max_major_ver,
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ssl->conf->max_minor_ver,
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ssl->conf->transport, p );
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MBEDTLS_SSL_DEBUG_MSG( 3, ( "supported version: [%d:%d]",
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ssl->conf->max_major_ver,
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ssl->conf->max_minor_ver ) );
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*out_len = 7;
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return( 0 );
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}
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static int ssl_tls13_parse_supported_versions_ext( mbedtls_ssl_context *ssl,
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const unsigned char *buf,
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const unsigned char *end )
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{
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((void) ssl);
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MBEDTLS_SSL_CHK_BUF_READ_PTR( buf, end, 2);
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if( buf[0] != MBEDTLS_SSL_MAJOR_VERSION_3 ||
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buf[1] != MBEDTLS_SSL_MINOR_VERSION_4 )
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{
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "unexpected version" ) );
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MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
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MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER);
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return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
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}
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return( 0 );
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}
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#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
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static int ssl_tls13_reset_key_share( mbedtls_ssl_context *ssl )
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{
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uint16_t group_id = ssl->handshake->offered_group_id;
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if( group_id == 0 )
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return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
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#if defined(MBEDTLS_ECDH_C)
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if( mbedtls_ssl_tls13_named_group_is_ecdhe( group_id ) )
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{
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mbedtls_ecdh_free( &ssl->handshake->ecdh_ctx );
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return( 0 );
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}
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else
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#endif /* MBEDTLS_ECDH_C */
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if( 0 /* other KEMs? */ )
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{
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/* Do something */
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}
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return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
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}
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/*
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* Functions for writing key_share extension.
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*/
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#if defined(MBEDTLS_ECDH_C)
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static int ssl_tls13_generate_and_write_ecdh_key_exchange(
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mbedtls_ssl_context *ssl,
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uint16_t named_group,
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unsigned char *buf,
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unsigned char *end,
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size_t *out_len )
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{
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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const mbedtls_ecp_curve_info *curve_info =
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mbedtls_ecp_curve_info_from_tls_id( named_group );
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if( curve_info == NULL )
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return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
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MBEDTLS_SSL_DEBUG_MSG( 3, ( "offer curve %s", curve_info->name ) );
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if( ( ret = mbedtls_ecdh_setup_no_everest( &ssl->handshake->ecdh_ctx,
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curve_info->grp_id ) ) != 0 )
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{
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MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_setup_no_everest", ret );
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return( ret );
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}
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ret = mbedtls_ecdh_tls13_make_params( &ssl->handshake->ecdh_ctx, out_len,
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buf, end - buf,
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ssl->conf->f_rng, ssl->conf->p_rng );
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if( ret != 0 )
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{
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MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_tls13_make_params", ret );
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return( ret );
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}
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MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
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MBEDTLS_DEBUG_ECDH_Q );
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return( 0 );
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}
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#endif /* MBEDTLS_ECDH_C */
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static int ssl_tls13_get_default_group_id( mbedtls_ssl_context *ssl,
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uint16_t *group_id )
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{
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int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
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#if defined(MBEDTLS_ECDH_C)
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const uint16_t *group_list = mbedtls_ssl_get_groups( ssl );
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/* Pick first available ECDHE group compatible with TLS 1.3 */
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if( group_list == NULL )
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return( MBEDTLS_ERR_SSL_BAD_CONFIG );
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for ( ; *group_list != 0; group_list++ )
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{
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const mbedtls_ecp_curve_info *curve_info;
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curve_info = mbedtls_ecp_curve_info_from_tls_id( *group_list );
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if( curve_info != NULL &&
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mbedtls_ssl_tls13_named_group_is_ecdhe( *group_list ) )
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{
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*group_id = *group_list;
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return( 0 );
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}
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}
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#else
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((void) ssl);
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((void) group_id);
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#endif /* MBEDTLS_ECDH_C */
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/*
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* Add DHE named groups here.
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* Pick first available DHE group compatible with TLS 1.3
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*/
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return( ret );
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}
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/*
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* ssl_tls13_write_key_share_ext
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*
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* Structure of key_share extension in ClientHello:
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*
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* struct {
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* NamedGroup group;
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* opaque key_exchange<1..2^16-1>;
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* } KeyShareEntry;
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* struct {
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* KeyShareEntry client_shares<0..2^16-1>;
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* } KeyShareClientHello;
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*/
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static int ssl_tls13_write_key_share_ext( mbedtls_ssl_context *ssl,
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unsigned char *buf,
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unsigned char *end,
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size_t *out_len )
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{
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unsigned char *p = buf;
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unsigned char *client_shares; /* Start of client_shares */
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size_t client_shares_len; /* Length of client_shares */
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uint16_t group_id;
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int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
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*out_len = 0;
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/* Check if we have space for header and length fields:
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* - extension_type (2 bytes)
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* - extension_data_length (2 bytes)
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* - client_shares_length (2 bytes)
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*/
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MBEDTLS_SSL_CHK_BUF_PTR( p, end, 6 );
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p += 6;
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MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello: adding key share extension" ) );
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/* HRR could already have requested something else. */
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group_id = ssl->handshake->offered_group_id;
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if( !mbedtls_ssl_tls13_named_group_is_ecdhe( group_id ) &&
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!mbedtls_ssl_tls13_named_group_is_dhe( group_id ) )
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{
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MBEDTLS_SSL_PROC_CHK( ssl_tls13_get_default_group_id( ssl,
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&group_id ) );
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}
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/*
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* Dispatch to type-specific key generation function.
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*
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* So far, we're only supporting ECDHE. With the introduction
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* of PQC KEMs, we'll want to have multiple branches, one per
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* type of KEM, and dispatch to the corresponding crypto. And
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* only one key share entry is allowed.
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*/
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client_shares = p;
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#if defined(MBEDTLS_ECDH_C)
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if( mbedtls_ssl_tls13_named_group_is_ecdhe( group_id ) )
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{
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/* Pointer to group */
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unsigned char *group = p;
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/* Length of key_exchange */
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size_t key_exchange_len;
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/* Check there is space for header of KeyShareEntry
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* - group (2 bytes)
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* - key_exchange_length (2 bytes)
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*/
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MBEDTLS_SSL_CHK_BUF_PTR( p, end, 4 );
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p += 4;
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ret = ssl_tls13_generate_and_write_ecdh_key_exchange( ssl, group_id,
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p, end,
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&key_exchange_len );
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p += key_exchange_len;
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if( ret != 0 )
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return( ret );
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/* Write group */
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MBEDTLS_PUT_UINT16_BE( group_id, group, 0 );
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/* Write key_exchange_length */
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MBEDTLS_PUT_UINT16_BE( key_exchange_len, group, 2 );
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}
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else
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#endif /* MBEDTLS_ECDH_C */
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if( 0 /* other KEMs? */ )
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{
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/* Do something */
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}
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else
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return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
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/* Length of client_shares */
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client_shares_len = p - client_shares;
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if( client_shares_len == 0)
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{
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "No key share defined." ) );
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return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
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}
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/* Write extension_type */
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MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_KEY_SHARE, buf, 0 );
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/* Write extension_data_length */
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MBEDTLS_PUT_UINT16_BE( client_shares_len + 2, buf, 2 );
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/* Write client_shares_length */
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MBEDTLS_PUT_UINT16_BE( client_shares_len, buf, 4 );
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/* Update offered_group_id field */
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ssl->handshake->offered_group_id = group_id;
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/* Output the total length of key_share extension. */
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*out_len = p - buf;
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MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, key_share extension", buf, *out_len );
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ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_KEY_SHARE;
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cleanup:
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return( ret );
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}
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#if defined(MBEDTLS_ECDH_C)
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static int ssl_tls13_check_ecdh_params( const mbedtls_ssl_context *ssl )
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{
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const mbedtls_ecp_curve_info *curve_info;
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mbedtls_ecp_group_id grp_id;
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#if defined(MBEDTLS_ECDH_LEGACY_CONTEXT)
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grp_id = ssl->handshake->ecdh_ctx.grp.id;
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#else
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grp_id = ssl->handshake->ecdh_ctx.grp_id;
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#endif
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curve_info = mbedtls_ecp_curve_info_from_grp_id( grp_id );
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if( curve_info == NULL )
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{
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
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return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
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}
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MBEDTLS_SSL_DEBUG_MSG( 2, ( "ECDH curve: %s", curve_info->name ) );
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if( mbedtls_ssl_check_curve( ssl, grp_id ) != 0 )
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return( -1 );
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MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
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MBEDTLS_DEBUG_ECDH_QP );
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return( 0 );
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}
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static int ssl_tls13_read_public_ecdhe_share( mbedtls_ssl_context *ssl,
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const unsigned char *buf,
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size_t buf_len )
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{
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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ret = mbedtls_ecdh_tls13_read_public( &ssl->handshake->ecdh_ctx,
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buf, buf_len );
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if( ret != 0 )
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{
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MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_tls13_read_public" ), ret );
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MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
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MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
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return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
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}
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if( ssl_tls13_check_ecdh_params( ssl ) != 0 )
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{
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "ssl_tls13_check_ecdh_params() failed!" ) );
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MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
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MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
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return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
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}
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return( 0 );
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}
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#endif /* MBEDTLS_ECDH_C */
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/*
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* ssl_tls13_parse_hrr_key_share_ext()
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* Parse key_share extension in Hello Retry Request
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*
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* struct {
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* NamedGroup selected_group;
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* } KeyShareHelloRetryRequest;
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*/
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static int ssl_tls13_parse_hrr_key_share_ext( mbedtls_ssl_context *ssl,
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const unsigned char *buf,
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const unsigned char *end )
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{
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const mbedtls_ecp_curve_info *curve_info = NULL;
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const unsigned char *p = buf;
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int selected_group;
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int found = 0;
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const uint16_t *group_list = mbedtls_ssl_get_groups( ssl );
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if( group_list == NULL )
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return( MBEDTLS_ERR_SSL_BAD_CONFIG );
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MBEDTLS_SSL_DEBUG_BUF( 3, "key_share extension", p, end - buf );
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/* Read selected_group */
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MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
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selected_group = MBEDTLS_GET_UINT16_BE( p, 0 );
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MBEDTLS_SSL_DEBUG_MSG( 3, ( "selected_group ( %d )", selected_group ) );
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/* Upon receipt of this extension in a HelloRetryRequest, the client
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* MUST first verify that the selected_group field corresponds to a
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* group which was provided in the "supported_groups" extension in the
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* original ClientHello.
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* The supported_group was based on the info in ssl->conf->group_list.
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*
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* If the server provided a key share that was not sent in the ClientHello
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* then the client MUST abort the handshake with an "illegal_parameter" alert.
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*/
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for( ; *group_list != 0; group_list++ )
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{
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curve_info = mbedtls_ecp_curve_info_from_tls_id( *group_list );
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if( curve_info == NULL || curve_info->tls_id != selected_group )
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continue;
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/* We found a match */
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found = 1;
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break;
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}
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/* Client MUST verify that the selected_group field does not
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* correspond to a group which was provided in the "key_share"
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* extension in the original ClientHello. If the server sent an
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* HRR message with a key share already provided in the
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* ClientHello then the client MUST abort the handshake with
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* an "illegal_parameter" alert.
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*/
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if( found == 0 || selected_group == ssl->handshake->offered_group_id )
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{
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "Invalid key share in HRR" ) );
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MBEDTLS_SSL_PEND_FATAL_ALERT(
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MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
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MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
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return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
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}
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/* Remember server's preference for next ClientHello */
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ssl->handshake->offered_group_id = selected_group;
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return( 0 );
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}
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/*
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* ssl_tls13_parse_key_share_ext()
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* Parse key_share extension in Server Hello
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*
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* struct {
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* KeyShareEntry server_share;
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* } KeyShareServerHello;
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* struct {
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* NamedGroup group;
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* opaque key_exchange<1..2^16-1>;
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* } KeyShareEntry;
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*/
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static int ssl_tls13_parse_key_share_ext( mbedtls_ssl_context *ssl,
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const unsigned char *buf,
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const unsigned char *end )
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{
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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const unsigned char *p = buf;
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uint16_t group, offered_group;
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|
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/* ...
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* NamedGroup group; (2 bytes)
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* ...
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*/
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MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
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group = MBEDTLS_GET_UINT16_BE( p, 0 );
|
|
p += 2;
|
|
|
|
/* Check that the chosen group matches the one we offered. */
|
|
offered_group = ssl->handshake->offered_group_id;
|
|
if( offered_group != group )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1,
|
|
( "Invalid server key share, our group %u, their group %u",
|
|
(unsigned) offered_group, (unsigned) group ) );
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE,
|
|
MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
|
|
return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
|
|
}
|
|
|
|
#if defined(MBEDTLS_ECDH_C)
|
|
if( mbedtls_ssl_tls13_named_group_is_ecdhe( group ) )
|
|
{
|
|
/* Complete ECDHE key agreement */
|
|
ret = ssl_tls13_read_public_ecdhe_share( ssl, p, end - p );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_ECDH_C */
|
|
if( 0 /* other KEMs? */ )
|
|
{
|
|
/* Do something */
|
|
}
|
|
else
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
|
|
ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_KEY_SHARE;
|
|
return( ret );
|
|
}
|
|
|
|
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
|
|
|
|
/*
|
|
* ssl_tls13_parse_cookie_ext()
|
|
* Parse cookie extension in Hello Retry Request
|
|
*
|
|
* struct {
|
|
* opaque cookie<1..2^16-1>;
|
|
* } Cookie;
|
|
*
|
|
* When sending a HelloRetryRequest, the server MAY provide a "cookie"
|
|
* extension to the client (this is an exception to the usual rule that
|
|
* the only extensions that may be sent are those that appear in the
|
|
* ClientHello). When sending the new ClientHello, the client MUST copy
|
|
* the contents of the extension received in the HelloRetryRequest into
|
|
* a "cookie" extension in the new ClientHello. Clients MUST NOT use
|
|
* cookies in their initial ClientHello in subsequent connections.
|
|
*/
|
|
static int ssl_tls13_parse_cookie_ext( mbedtls_ssl_context *ssl,
|
|
const unsigned char *buf,
|
|
const unsigned char *end )
|
|
{
|
|
size_t cookie_len;
|
|
const unsigned char *p = buf;
|
|
mbedtls_ssl_handshake_params *handshake = ssl->handshake;
|
|
|
|
/* Retrieve length field of cookie */
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
|
|
cookie_len = MBEDTLS_GET_UINT16_BE( p, 0 );
|
|
p += 2;
|
|
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, cookie_len );
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "cookie extension", p, cookie_len );
|
|
|
|
mbedtls_free( handshake->verify_cookie );
|
|
handshake->verify_cookie_len = 0;
|
|
handshake->verify_cookie = mbedtls_calloc( 1, cookie_len );
|
|
if( handshake->verify_cookie == NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1,
|
|
( "alloc failed ( %" MBEDTLS_PRINTF_SIZET " bytes )",
|
|
cookie_len ) );
|
|
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
|
|
}
|
|
|
|
memcpy( handshake->verify_cookie, p, cookie_len );
|
|
handshake->verify_cookie_len = (unsigned char) cookie_len;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/* Write cipher_suites
|
|
* CipherSuite cipher_suites<2..2^16-2>;
|
|
*/
|
|
static int ssl_tls13_write_client_hello_cipher_suites(
|
|
mbedtls_ssl_context *ssl,
|
|
unsigned char *buf,
|
|
unsigned char *end,
|
|
size_t *out_len )
|
|
{
|
|
unsigned char *p = buf;
|
|
const int *ciphersuite_list;
|
|
unsigned char *cipher_suites; /* Start of the cipher_suites list */
|
|
size_t cipher_suites_len;
|
|
|
|
*out_len = 0 ;
|
|
|
|
/*
|
|
* Ciphersuite list
|
|
*
|
|
* This is a list of the symmetric cipher options supported by
|
|
* the client, specifically the record protection algorithm
|
|
* ( including secret key length ) and a hash to be used with
|
|
* HKDF, in descending order of client preference.
|
|
*/
|
|
ciphersuite_list = ssl->conf->ciphersuite_list;
|
|
|
|
/* Check there is space for the cipher suite list length (2 bytes). */
|
|
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
|
|
p += 2;
|
|
|
|
/* Write cipher_suites */
|
|
cipher_suites = p;
|
|
for ( size_t i = 0; ciphersuite_list[i] != 0; i++ )
|
|
{
|
|
int cipher_suite = ciphersuite_list[i];
|
|
const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
|
|
|
|
ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( cipher_suite );
|
|
if( ciphersuite_info == NULL )
|
|
continue;
|
|
if( !( MBEDTLS_SSL_MINOR_VERSION_4 >= ciphersuite_info->min_minor_ver &&
|
|
MBEDTLS_SSL_MINOR_VERSION_4 <= ciphersuite_info->max_minor_ver ) )
|
|
continue;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, add ciphersuite: %04x, %s",
|
|
(unsigned int) cipher_suite,
|
|
ciphersuite_info->name ) );
|
|
|
|
/* Check there is space for the cipher suite identifier (2 bytes). */
|
|
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
|
|
MBEDTLS_PUT_UINT16_BE( cipher_suite, p, 0 );
|
|
p += 2;
|
|
}
|
|
|
|
/* Write the cipher_suites length in number of bytes */
|
|
cipher_suites_len = p - cipher_suites;
|
|
MBEDTLS_PUT_UINT16_BE( cipher_suites_len, buf, 0 );
|
|
MBEDTLS_SSL_DEBUG_MSG( 3,
|
|
( "client hello, got %" MBEDTLS_PRINTF_SIZET " cipher suites",
|
|
cipher_suites_len/2 ) );
|
|
|
|
/* Output the total length of cipher_suites field. */
|
|
*out_len = p - buf;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Structure of ClientHello message:
|
|
*
|
|
* struct {
|
|
* ProtocolVersion legacy_version = 0x0303; // TLS v1.2
|
|
* Random random;
|
|
* opaque legacy_session_id<0..32>;
|
|
* CipherSuite cipher_suites<2..2^16-2>;
|
|
* opaque legacy_compression_methods<1..2^8-1>;
|
|
* Extension extensions<8..2^16-1>;
|
|
* } ClientHello;
|
|
*/
|
|
static int ssl_tls13_write_client_hello_body( mbedtls_ssl_context *ssl,
|
|
unsigned char *buf,
|
|
unsigned char *end,
|
|
size_t *out_len )
|
|
{
|
|
|
|
int ret;
|
|
unsigned char *p_extensions_len; /* Pointer to extensions length */
|
|
size_t output_len; /* Length of buffer used by function */
|
|
size_t extensions_len; /* Length of the list of extensions*/
|
|
|
|
/* Buffer management */
|
|
unsigned char *p = buf;
|
|
|
|
*out_len = 0;
|
|
|
|
/* No validation needed here. It has been done by ssl_conf_check() */
|
|
ssl->major_ver = ssl->conf->min_major_ver;
|
|
ssl->minor_ver = ssl->conf->min_minor_ver;
|
|
|
|
/*
|
|
* Write legacy_version
|
|
* ProtocolVersion legacy_version = 0x0303; // TLS v1.2
|
|
*
|
|
* For TLS 1.3 we use the legacy version number {0x03, 0x03}
|
|
* instead of the true version number.
|
|
*/
|
|
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
|
|
MBEDTLS_PUT_UINT16_BE( 0x0303, p, 0 );
|
|
p += 2;
|
|
|
|
/* Write the random bytes ( random ).*/
|
|
MBEDTLS_SSL_CHK_BUF_PTR( p, end, MBEDTLS_CLIENT_HELLO_RANDOM_LEN );
|
|
memcpy( p, ssl->handshake->randbytes, MBEDTLS_CLIENT_HELLO_RANDOM_LEN );
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes",
|
|
p, MBEDTLS_CLIENT_HELLO_RANDOM_LEN );
|
|
p += MBEDTLS_CLIENT_HELLO_RANDOM_LEN;
|
|
|
|
/*
|
|
* Write legacy_session_id
|
|
*
|
|
* Versions of TLS before TLS 1.3 supported a "session resumption" feature
|
|
* which has been merged with pre-shared keys in this version. A client
|
|
* which has a cached session ID set by a pre-TLS 1.3 server SHOULD set
|
|
* this field to that value. In compatibility mode, this field MUST be
|
|
* non-empty, so a client not offering a pre-TLS 1.3 session MUST generate
|
|
* a new 32-byte value. This value need not be random but SHOULD be
|
|
* unpredictable to avoid implementations fixating on a specific value
|
|
* ( also known as ossification ). Otherwise, it MUST be set as a zero-length
|
|
* vector ( i.e., a zero-valued single byte length field ).
|
|
*/
|
|
#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE)
|
|
MBEDTLS_SSL_CHK_BUF_PTR( p, end, ssl->session_negotiate->id_len + 1 );
|
|
*p++ = (unsigned char)ssl->session_negotiate->id_len;
|
|
memcpy( p, ssl->session_negotiate->id, ssl->session_negotiate->id_len );
|
|
p += ssl->session_negotiate->id_len;
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "session id", ssl->session_negotiate->id,
|
|
ssl->session_negotiate->id_len );
|
|
#else
|
|
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 1 );
|
|
*p++ = 0; /* session id length set to zero */
|
|
#endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */
|
|
|
|
/* Write cipher_suites */
|
|
ret = ssl_tls13_write_client_hello_cipher_suites( ssl, p, end, &output_len );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
p += output_len;
|
|
|
|
/* Write legacy_compression_methods
|
|
*
|
|
* For every TLS 1.3 ClientHello, this vector MUST contain exactly
|
|
* one byte set to zero, which corresponds to the 'null' compression
|
|
* method in prior versions of TLS.
|
|
*/
|
|
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
|
|
*p++ = 1;
|
|
*p++ = MBEDTLS_SSL_COMPRESS_NULL;
|
|
|
|
/* Write extensions */
|
|
|
|
/* Keeping track of the included extensions */
|
|
ssl->handshake->extensions_present = MBEDTLS_SSL_EXT_NONE;
|
|
|
|
/* First write extensions, then the total length */
|
|
MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
|
|
p_extensions_len = p;
|
|
p += 2;
|
|
|
|
/* Write supported_versions extension
|
|
*
|
|
* Supported Versions Extension is mandatory with TLS 1.3.
|
|
*/
|
|
ret = ssl_tls13_write_supported_versions_ext( ssl, p, end, &output_len );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
p += output_len;
|
|
|
|
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
|
|
|
|
/*
|
|
* Add the extensions related to (EC)DHE ephemeral key establishment only if
|
|
* enabled as per the configuration.
|
|
*/
|
|
if( mbedtls_ssl_conf_tls13_some_ephemeral_enabled( ssl ) )
|
|
{
|
|
ret = mbedtls_ssl_write_supported_groups_ext( ssl, p, end, &output_len );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
p += output_len;
|
|
|
|
ret = ssl_tls13_write_key_share_ext( ssl, p, end, &output_len );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
p += output_len;
|
|
|
|
ret = mbedtls_ssl_write_sig_alg_ext( ssl, p, end, &output_len );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
p += output_len;
|
|
}
|
|
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
|
|
|
|
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
|
|
/* Write server name extension */
|
|
ret = mbedtls_ssl_write_hostname_ext( ssl, p, end, &output_len );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
p += output_len;
|
|
#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
|
|
|
|
/* Add more extensions here */
|
|
|
|
/* Write the length of the list of extensions. */
|
|
extensions_len = p - p_extensions_len - 2;
|
|
MBEDTLS_PUT_UINT16_BE( extensions_len, p_extensions_len, 0 );
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, total extension length: %" MBEDTLS_PRINTF_SIZET ,
|
|
extensions_len ) );
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "client hello extensions", p_extensions_len, extensions_len );
|
|
|
|
*out_len = p - buf;
|
|
return( 0 );
|
|
}
|
|
|
|
static int ssl_tls13_finalize_client_hello( mbedtls_ssl_context *ssl )
|
|
{
|
|
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_HELLO );
|
|
return( 0 );
|
|
}
|
|
|
|
static int ssl_tls13_prepare_client_hello( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret;
|
|
|
|
if( ssl->conf->f_rng == NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "no RNG provided" ) );
|
|
return( MBEDTLS_ERR_SSL_NO_RNG );
|
|
}
|
|
|
|
if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng,
|
|
ssl->handshake->randbytes,
|
|
MBEDTLS_CLIENT_HELLO_RANDOM_LEN ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "f_rng", ret );
|
|
return( ret );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE)
|
|
/*
|
|
* Create a session identifier for the purpose of middlebox compatibility
|
|
* only if one has not been created already.
|
|
*/
|
|
if( ssl->session_negotiate->id_len == 0 )
|
|
{
|
|
/* Creating a session id with 32 byte length */
|
|
if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng,
|
|
ssl->session_negotiate->id, 32 ) ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "creating session id failed", ret );
|
|
return( ret );
|
|
}
|
|
ssl->session_negotiate->id_len = 32;
|
|
}
|
|
#endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Write ClientHello handshake message.
|
|
* Handler for MBEDTLS_SSL_CLIENT_HELLO
|
|
*/
|
|
static int ssl_tls13_write_client_hello( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = 0;
|
|
unsigned char *buf;
|
|
size_t buf_len, msg_len;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write client hello" ) );
|
|
|
|
MBEDTLS_SSL_PROC_CHK( ssl_tls13_prepare_client_hello( ssl ) );
|
|
|
|
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_start_handshake_msg(
|
|
ssl, MBEDTLS_SSL_HS_CLIENT_HELLO,
|
|
&buf, &buf_len ) );
|
|
|
|
MBEDTLS_SSL_PROC_CHK( ssl_tls13_write_client_hello_body( ssl, buf,
|
|
buf + buf_len,
|
|
&msg_len ) );
|
|
|
|
mbedtls_ssl_tls13_add_hs_hdr_to_checksum( ssl,
|
|
MBEDTLS_SSL_HS_CLIENT_HELLO,
|
|
msg_len );
|
|
ssl->handshake->update_checksum( ssl, buf, msg_len );
|
|
|
|
MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_client_hello( ssl ) );
|
|
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_finish_handshake_msg( ssl,
|
|
buf_len,
|
|
msg_len ) );
|
|
|
|
cleanup:
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write client hello" ) );
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Functions for parsing and processing Server Hello
|
|
*/
|
|
/* Returns a negative value on failure, and otherwise
|
|
* - SSL_SERVER_HELLO_COORDINATE_HELLO or
|
|
* - SSL_SERVER_HELLO_COORDINATE_HRR
|
|
* to indicate which message is expected and to be parsed next.
|
|
*/
|
|
#define SSL_SERVER_HELLO_COORDINATE_HELLO 0
|
|
#define SSL_SERVER_HELLO_COORDINATE_HRR 1
|
|
static int ssl_server_hello_is_hrr( mbedtls_ssl_context *ssl,
|
|
const unsigned char *buf,
|
|
const unsigned char *end )
|
|
{
|
|
static const unsigned char magic_hrr_string[MBEDTLS_SERVER_HELLO_RANDOM_LEN] =
|
|
{ 0xCF, 0x21, 0xAD, 0x74, 0xE5, 0x9A, 0x61, 0x11,
|
|
0xBE, 0x1D, 0x8C, 0x02, 0x1E, 0x65, 0xB8, 0x91,
|
|
0xC2, 0xA2, 0x11, 0x16, 0x7A, 0xBB, 0x8C, 0x5E,
|
|
0x07, 0x9E, 0x09, 0xE2, 0xC8, 0xA8, 0x33 ,0x9C };
|
|
|
|
/* Check whether this message is a HelloRetryRequest ( HRR ) message.
|
|
*
|
|
* Server Hello and HRR are only distinguished by Random set to the
|
|
* special value of the SHA-256 of "HelloRetryRequest".
|
|
*
|
|
* struct {
|
|
* ProtocolVersion legacy_version = 0x0303;
|
|
* Random random;
|
|
* opaque legacy_session_id_echo<0..32>;
|
|
* CipherSuite cipher_suite;
|
|
* uint8 legacy_compression_method = 0;
|
|
* Extension extensions<6..2^16-1>;
|
|
* } ServerHello;
|
|
*
|
|
*/
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( buf, end, 2 + sizeof( magic_hrr_string ) );
|
|
|
|
if( memcmp( buf + 2, magic_hrr_string, sizeof( magic_hrr_string ) ) == 0 )
|
|
{
|
|
return( SSL_SERVER_HELLO_COORDINATE_HRR );
|
|
}
|
|
|
|
return( SSL_SERVER_HELLO_COORDINATE_HELLO );
|
|
}
|
|
|
|
/* Fetch and preprocess
|
|
* Returns a negative value on failure, and otherwise
|
|
* - SSL_SERVER_HELLO_COORDINATE_HELLO or
|
|
* - SSL_SERVER_HELLO_COORDINATE_HRR
|
|
*/
|
|
static int ssl_tls13_server_hello_coordinate( mbedtls_ssl_context *ssl,
|
|
unsigned char **buf,
|
|
size_t *buf_len )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_fetch_handshake_msg( ssl,
|
|
MBEDTLS_SSL_HS_SERVER_HELLO,
|
|
buf, buf_len ) );
|
|
|
|
ret = ssl_server_hello_is_hrr( ssl, *buf, *buf + *buf_len );
|
|
switch( ret )
|
|
{
|
|
case SSL_SERVER_HELLO_COORDINATE_HELLO:
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "received ServerHello message" ) );
|
|
break;
|
|
case SSL_SERVER_HELLO_COORDINATE_HRR:
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "received HelloRetryRequest message" ) );
|
|
/* If a client receives a second
|
|
* HelloRetryRequest in the same connection (i.e., where the ClientHello
|
|
* was itself in response to a HelloRetryRequest), it MUST abort the
|
|
* handshake with an "unexpected_message" alert.
|
|
*/
|
|
if( ssl->handshake->hello_retry_request_count > 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Multiple HRRs received" ) );
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE,
|
|
MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
|
|
return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
|
|
}
|
|
/*
|
|
* Clients must abort the handshake with an "illegal_parameter"
|
|
* alert if the HelloRetryRequest would not result in any change
|
|
* in the ClientHello.
|
|
* In a PSK only key exchange that what we expect.
|
|
*/
|
|
if( ! mbedtls_ssl_conf_tls13_some_ephemeral_enabled( ssl ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1,
|
|
( "Unexpected HRR in pure PSK key exchange." ) );
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT(
|
|
MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
|
|
MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER);
|
|
return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
|
|
}
|
|
|
|
ssl->handshake->hello_retry_request_count++;
|
|
|
|
break;
|
|
}
|
|
|
|
cleanup:
|
|
|
|
return( ret );
|
|
}
|
|
|
|
static int ssl_tls13_check_server_hello_session_id_echo( mbedtls_ssl_context *ssl,
|
|
const unsigned char **buf,
|
|
const unsigned char *end )
|
|
{
|
|
const unsigned char *p = *buf;
|
|
size_t legacy_session_id_echo_len;
|
|
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 1 );
|
|
legacy_session_id_echo_len = *p++ ;
|
|
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, legacy_session_id_echo_len );
|
|
|
|
/* legacy_session_id_echo */
|
|
if( ssl->session_negotiate->id_len != legacy_session_id_echo_len ||
|
|
memcmp( ssl->session_negotiate->id, p , legacy_session_id_echo_len ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "Expected Session ID",
|
|
ssl->session_negotiate->id,
|
|
ssl->session_negotiate->id_len );
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "Received Session ID", p,
|
|
legacy_session_id_echo_len );
|
|
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
|
|
MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER);
|
|
|
|
return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
|
|
}
|
|
|
|
p += legacy_session_id_echo_len;
|
|
*buf = p;
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "Session ID", ssl->session_negotiate->id,
|
|
ssl->session_negotiate->id_len );
|
|
return( 0 );
|
|
}
|
|
|
|
static int ssl_tls13_cipher_suite_is_offered( mbedtls_ssl_context *ssl,
|
|
int cipher_suite )
|
|
{
|
|
const int *ciphersuite_list = ssl->conf->ciphersuite_list;
|
|
|
|
/* Check whether we have offered this ciphersuite */
|
|
for ( size_t i = 0; ciphersuite_list[i] != 0; i++ )
|
|
{
|
|
if( ciphersuite_list[i] == cipher_suite )
|
|
{
|
|
return( 1 );
|
|
}
|
|
}
|
|
return( 0 );
|
|
}
|
|
|
|
/* Parse ServerHello message and configure context
|
|
*
|
|
* struct {
|
|
* ProtocolVersion legacy_version = 0x0303; // TLS 1.2
|
|
* Random random;
|
|
* opaque legacy_session_id_echo<0..32>;
|
|
* CipherSuite cipher_suite;
|
|
* uint8 legacy_compression_method = 0;
|
|
* Extension extensions<6..2^16-1>;
|
|
* } ServerHello;
|
|
*/
|
|
static int ssl_tls13_parse_server_hello( mbedtls_ssl_context *ssl,
|
|
const unsigned char *buf,
|
|
const unsigned char *end,
|
|
int is_hrr )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
const unsigned char *p = buf;
|
|
mbedtls_ssl_handshake_params *handshake = ssl->handshake;
|
|
size_t extensions_len;
|
|
const unsigned char *extensions_end;
|
|
uint16_t cipher_suite;
|
|
const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
|
|
int supported_versions_ext_found = 0;
|
|
int fatal_alert = 0;
|
|
|
|
/*
|
|
* Check there is space for minimal fields
|
|
*
|
|
* - legacy_version ( 2 bytes)
|
|
* - random (MBEDTLS_SERVER_HELLO_RANDOM_LEN bytes)
|
|
* - legacy_session_id_echo ( 1 byte ), minimum size
|
|
* - cipher_suite ( 2 bytes)
|
|
* - legacy_compression_method ( 1 byte )
|
|
*/
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, MBEDTLS_SERVER_HELLO_RANDOM_LEN + 6 );
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 4, "server hello", p, end - p );
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, version", p, 2 );
|
|
|
|
/* ...
|
|
* ProtocolVersion legacy_version = 0x0303; // TLS 1.2
|
|
* ...
|
|
* with ProtocolVersion defined as:
|
|
* uint16 ProtocolVersion;
|
|
*/
|
|
if( !( p[0] == MBEDTLS_SSL_MAJOR_VERSION_3 &&
|
|
p[1] == MBEDTLS_SSL_MINOR_VERSION_3 ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Unsupported version of TLS." ) );
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION,
|
|
MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION );
|
|
ret = MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION;
|
|
goto cleanup;
|
|
}
|
|
p += 2;
|
|
|
|
/* ...
|
|
* Random random;
|
|
* ...
|
|
* with Random defined as:
|
|
* opaque Random[MBEDTLS_SERVER_HELLO_RANDOM_LEN];
|
|
*/
|
|
if( !is_hrr )
|
|
{
|
|
memcpy( &handshake->randbytes[MBEDTLS_CLIENT_HELLO_RANDOM_LEN], p,
|
|
MBEDTLS_SERVER_HELLO_RANDOM_LEN );
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes",
|
|
p, MBEDTLS_SERVER_HELLO_RANDOM_LEN );
|
|
}
|
|
p += MBEDTLS_SERVER_HELLO_RANDOM_LEN;
|
|
|
|
/* ...
|
|
* opaque legacy_session_id_echo<0..32>;
|
|
* ...
|
|
*/
|
|
if( ssl_tls13_check_server_hello_session_id_echo( ssl, &p, end ) != 0 )
|
|
{
|
|
fatal_alert = MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER;
|
|
goto cleanup;
|
|
}
|
|
|
|
/* ...
|
|
* CipherSuite cipher_suite;
|
|
* ...
|
|
* with CipherSuite defined as:
|
|
* uint8 CipherSuite[2];
|
|
*/
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
|
|
cipher_suite = MBEDTLS_GET_UINT16_BE( p, 0 );
|
|
p += 2;
|
|
|
|
|
|
ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( cipher_suite );
|
|
/*
|
|
* Check whether this ciphersuite is supported and offered.
|
|
* Via the force_ciphersuite version we may have instructed the client
|
|
* to use a different ciphersuite.
|
|
*/
|
|
if( ciphersuite_info == NULL ||
|
|
ssl_tls13_cipher_suite_is_offered( ssl, cipher_suite ) == 0 )
|
|
{
|
|
fatal_alert = MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER;
|
|
}
|
|
/*
|
|
* If we received an HRR before and that the proposed selected
|
|
* ciphersuite in this server hello is not the same as the one
|
|
* proposed in the HRR, we abort the handshake and send an
|
|
* "illegal_parameter" alert.
|
|
*/
|
|
else if( ( !is_hrr ) && ( handshake->hello_retry_request_count > 0 ) &&
|
|
( cipher_suite != ssl->session_negotiate->ciphersuite ) )
|
|
{
|
|
fatal_alert = MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER;
|
|
}
|
|
|
|
if( fatal_alert == MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid ciphersuite(%04x) parameter",
|
|
cipher_suite ) );
|
|
goto cleanup;
|
|
}
|
|
|
|
/* Configure ciphersuites */
|
|
mbedtls_ssl_optimize_checksum( ssl, ciphersuite_info );
|
|
|
|
handshake->ciphersuite_info = ciphersuite_info;
|
|
ssl->session_negotiate->ciphersuite = cipher_suite;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: ( %04x ) - %s",
|
|
cipher_suite, ciphersuite_info->name ) );
|
|
|
|
#if defined(MBEDTLS_HAVE_TIME)
|
|
ssl->session_negotiate->start = time( NULL );
|
|
#endif /* MBEDTLS_HAVE_TIME */
|
|
|
|
/* ...
|
|
* uint8 legacy_compression_method = 0;
|
|
* ...
|
|
*/
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 1 );
|
|
if( p[0] != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad legacy compression method" ) );
|
|
fatal_alert = MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER;
|
|
goto cleanup;
|
|
}
|
|
p++;
|
|
|
|
/* ...
|
|
* Extension extensions<6..2^16-1>;
|
|
* ...
|
|
* struct {
|
|
* ExtensionType extension_type; (2 bytes)
|
|
* opaque extension_data<0..2^16-1>;
|
|
* } Extension;
|
|
*/
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
|
|
extensions_len = MBEDTLS_GET_UINT16_BE( p, 0 );
|
|
p += 2;
|
|
|
|
/* Check extensions do not go beyond the buffer of data. */
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, extensions_len );
|
|
extensions_end = p + extensions_len;
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "server hello extensions", p, extensions_len );
|
|
|
|
while( p < extensions_end )
|
|
{
|
|
unsigned int extension_type;
|
|
size_t extension_data_len;
|
|
const unsigned char *extension_data_end;
|
|
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, 4 );
|
|
extension_type = MBEDTLS_GET_UINT16_BE( p, 0 );
|
|
extension_data_len = MBEDTLS_GET_UINT16_BE( p, 2 );
|
|
p += 4;
|
|
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, extension_data_len );
|
|
extension_data_end = p + extension_data_len;
|
|
|
|
switch( extension_type )
|
|
{
|
|
case MBEDTLS_TLS_EXT_COOKIE:
|
|
|
|
if( !is_hrr )
|
|
{
|
|
fatal_alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT;
|
|
goto cleanup;
|
|
}
|
|
|
|
ret = ssl_tls13_parse_cookie_ext( ssl,
|
|
p, extension_data_end );
|
|
if( ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1,
|
|
"ssl_tls13_parse_cookie_ext",
|
|
ret );
|
|
goto cleanup;
|
|
}
|
|
break;
|
|
|
|
case MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS:
|
|
supported_versions_ext_found = 1;
|
|
MBEDTLS_SSL_DEBUG_MSG( 3,
|
|
( "found supported_versions extension" ) );
|
|
|
|
ret = ssl_tls13_parse_supported_versions_ext( ssl,
|
|
p,
|
|
extension_data_end );
|
|
if( ret != 0 )
|
|
goto cleanup;
|
|
break;
|
|
|
|
case MBEDTLS_TLS_EXT_PRE_SHARED_KEY:
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found pre_shared_key extension." ) );
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "pre_shared_key:Not supported yet" ) );
|
|
|
|
fatal_alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT;
|
|
goto cleanup;
|
|
|
|
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
|
|
case MBEDTLS_TLS_EXT_KEY_SHARE:
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found key_shares extension" ) );
|
|
if( ! mbedtls_ssl_conf_tls13_some_ephemeral_enabled( ssl ) )
|
|
{
|
|
fatal_alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT;
|
|
goto cleanup;
|
|
}
|
|
|
|
if( is_hrr )
|
|
ret = ssl_tls13_parse_hrr_key_share_ext( ssl,
|
|
p, extension_data_end );
|
|
else
|
|
ret = ssl_tls13_parse_key_share_ext( ssl,
|
|
p, extension_data_end );
|
|
if( ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1,
|
|
"ssl_tls13_parse_key_share_ext",
|
|
ret );
|
|
goto cleanup;
|
|
}
|
|
break;
|
|
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
|
|
|
|
default:
|
|
MBEDTLS_SSL_DEBUG_MSG(
|
|
3,
|
|
( "unknown extension found: %u ( ignoring )",
|
|
extension_type ) );
|
|
|
|
fatal_alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT;
|
|
goto cleanup;
|
|
}
|
|
|
|
p += extension_data_len;
|
|
}
|
|
|
|
if( !supported_versions_ext_found )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "supported_versions not found" ) );
|
|
fatal_alert = MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER;
|
|
goto cleanup;
|
|
}
|
|
|
|
cleanup:
|
|
|
|
if( fatal_alert == MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT )
|
|
{
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT,
|
|
MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION );
|
|
ret = MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION;
|
|
}
|
|
else if ( fatal_alert == MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER )
|
|
{
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
|
|
MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
|
|
ret = MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER;
|
|
}
|
|
return( ret );
|
|
}
|
|
|
|
static int ssl_tls13_postprocess_server_hello( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
mbedtls_ssl_key_set traffic_keys;
|
|
mbedtls_ssl_transform *transform_handshake = NULL;
|
|
mbedtls_ssl_handshake_params *handshake = ssl->handshake;
|
|
|
|
/* Determine the key exchange mode:
|
|
* 1) If both the pre_shared_key and key_share extensions were received
|
|
* then the key exchange mode is PSK with EPHEMERAL.
|
|
* 2) If only the pre_shared_key extension was received then the key
|
|
* exchange mode is PSK-only.
|
|
* 3) If only the key_share extension was received then the key
|
|
* exchange mode is EPHEMERAL-only.
|
|
*/
|
|
switch( handshake->extensions_present &
|
|
( MBEDTLS_SSL_EXT_PRE_SHARED_KEY | MBEDTLS_SSL_EXT_KEY_SHARE ) )
|
|
{
|
|
/* Only the pre_shared_key extension was received */
|
|
case MBEDTLS_SSL_EXT_PRE_SHARED_KEY:
|
|
handshake->tls13_kex_modes = MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK;
|
|
break;
|
|
|
|
/* Only the key_share extension was received */
|
|
case MBEDTLS_SSL_EXT_KEY_SHARE:
|
|
handshake->tls13_kex_modes = MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL;
|
|
break;
|
|
|
|
/* Both the pre_shared_key and key_share extensions were received */
|
|
case ( MBEDTLS_SSL_EXT_PRE_SHARED_KEY | MBEDTLS_SSL_EXT_KEY_SHARE ):
|
|
handshake->tls13_kex_modes = MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL;
|
|
break;
|
|
|
|
/* Neither pre_shared_key nor key_share extension was received */
|
|
default:
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Unknown key exchange." ) );
|
|
ret = MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE;
|
|
goto cleanup;
|
|
}
|
|
|
|
/* Start the TLS 1.3 key schedule: Set the PSK and derive early secret.
|
|
*
|
|
* TODO: We don't have to do this in case we offered 0-RTT and the
|
|
* server accepted it. In this case, we could skip generating
|
|
* the early secret. */
|
|
ret = mbedtls_ssl_tls13_key_schedule_stage_early( ssl );
|
|
if( ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_key_schedule_stage_early_data",
|
|
ret );
|
|
goto cleanup;
|
|
}
|
|
|
|
/* Compute handshake secret */
|
|
ret = mbedtls_ssl_tls13_key_schedule_stage_handshake( ssl );
|
|
if( ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_derive_master_secret", ret );
|
|
goto cleanup;
|
|
}
|
|
|
|
/* Next evolution in key schedule: Establish handshake secret and
|
|
* key material. */
|
|
ret = mbedtls_ssl_tls13_generate_handshake_keys( ssl, &traffic_keys );
|
|
if( ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_generate_handshake_keys",
|
|
ret );
|
|
goto cleanup;
|
|
}
|
|
|
|
transform_handshake = mbedtls_calloc( 1, sizeof( mbedtls_ssl_transform ) );
|
|
if( transform_handshake == NULL )
|
|
{
|
|
ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
|
|
goto cleanup;
|
|
}
|
|
|
|
ret = mbedtls_ssl_tls13_populate_transform( transform_handshake,
|
|
ssl->conf->endpoint,
|
|
ssl->session_negotiate->ciphersuite,
|
|
&traffic_keys,
|
|
ssl );
|
|
if( ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_populate_transform", ret );
|
|
goto cleanup;
|
|
}
|
|
|
|
handshake->transform_handshake = transform_handshake;
|
|
mbedtls_ssl_set_inbound_transform( ssl, transform_handshake );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Switch to handshake keys for inbound traffic" ) );
|
|
ssl->session_in = ssl->session_negotiate;
|
|
|
|
/*
|
|
* State machine update
|
|
*/
|
|
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_ENCRYPTED_EXTENSIONS );
|
|
|
|
cleanup:
|
|
|
|
mbedtls_platform_zeroize( &traffic_keys, sizeof( traffic_keys ) );
|
|
if( ret != 0 )
|
|
{
|
|
mbedtls_free( transform_handshake );
|
|
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT(
|
|
MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE,
|
|
MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
|
|
}
|
|
return( ret );
|
|
}
|
|
|
|
static int ssl_tls13_postprocess_hrr( mbedtls_ssl_context *ssl )
|
|
{
|
|
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE)
|
|
/* If not offering early data, the client sends a dummy CCS record
|
|
* immediately before its second flight. This may either be before
|
|
* its second ClientHello or before its encrypted handshake flight.
|
|
*/
|
|
mbedtls_ssl_handshake_set_state( ssl,
|
|
MBEDTLS_SSL_CLIENT_CCS_BEFORE_2ND_CLIENT_HELLO );
|
|
#else
|
|
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_HELLO );
|
|
#endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */
|
|
|
|
mbedtls_ssl_session_reset_msg_layer( ssl, 0 );
|
|
|
|
/*
|
|
* We are going to re-generate a shared secret corresponding to the group
|
|
* selected by the server, which is different from the group for which we
|
|
* generated a shared secret in the first client hello.
|
|
* Thus, reset the shared secret.
|
|
*/
|
|
ret = ssl_tls13_reset_key_share( ssl );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
#else
|
|
((void) ssl);
|
|
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Wait and parse ServerHello handshake message.
|
|
* Handler for MBEDTLS_SSL_SERVER_HELLO
|
|
*/
|
|
static int ssl_tls13_process_server_hello( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
unsigned char *buf = NULL;
|
|
size_t buf_len = 0;
|
|
int is_hrr = 0;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> %s", __func__ ) );
|
|
|
|
/* Coordination step
|
|
* - Fetch record
|
|
* - Make sure it's either a ServerHello or a HRR.
|
|
* - Switch processing routine in case of HRR
|
|
*/
|
|
ssl->major_ver = MBEDTLS_SSL_MAJOR_VERSION_3;
|
|
ssl->handshake->extensions_present = MBEDTLS_SSL_EXT_NONE;
|
|
|
|
ret = ssl_tls13_server_hello_coordinate( ssl, &buf, &buf_len );
|
|
if( ret < 0 )
|
|
goto cleanup;
|
|
else
|
|
is_hrr = ( ret == SSL_SERVER_HELLO_COORDINATE_HRR );
|
|
|
|
MBEDTLS_SSL_PROC_CHK( ssl_tls13_parse_server_hello( ssl, buf,
|
|
buf + buf_len,
|
|
is_hrr ) );
|
|
if( is_hrr )
|
|
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_reset_transcript_for_hrr( ssl ) );
|
|
|
|
mbedtls_ssl_tls13_add_hs_msg_to_checksum( ssl,
|
|
MBEDTLS_SSL_HS_SERVER_HELLO,
|
|
buf, buf_len );
|
|
|
|
if( is_hrr )
|
|
MBEDTLS_SSL_PROC_CHK( ssl_tls13_postprocess_hrr( ssl ) );
|
|
else
|
|
MBEDTLS_SSL_PROC_CHK( ssl_tls13_postprocess_server_hello( ssl ) );
|
|
|
|
cleanup:
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= %s ( %s )", __func__,
|
|
is_hrr?"HelloRetryRequest":"ServerHello" ) );
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
*
|
|
* EncryptedExtensions message
|
|
*
|
|
* The EncryptedExtensions message contains any extensions which
|
|
* should be protected, i.e., any which are not needed to establish
|
|
* the cryptographic context.
|
|
*/
|
|
|
|
/*
|
|
* Overview
|
|
*/
|
|
|
|
/* Main entry point; orchestrates the other functions */
|
|
static int ssl_tls13_process_encrypted_extensions( mbedtls_ssl_context *ssl );
|
|
|
|
static int ssl_tls13_parse_encrypted_extensions( mbedtls_ssl_context *ssl,
|
|
const unsigned char *buf,
|
|
const unsigned char *end );
|
|
static int ssl_tls13_postprocess_encrypted_extensions( mbedtls_ssl_context *ssl );
|
|
|
|
/*
|
|
* Handler for MBEDTLS_SSL_ENCRYPTED_EXTENSIONS
|
|
*/
|
|
static int ssl_tls13_process_encrypted_extensions( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret;
|
|
unsigned char *buf;
|
|
size_t buf_len;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse encrypted extensions" ) );
|
|
|
|
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_fetch_handshake_msg( ssl,
|
|
MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS,
|
|
&buf, &buf_len ) );
|
|
|
|
/* Process the message contents */
|
|
MBEDTLS_SSL_PROC_CHK(
|
|
ssl_tls13_parse_encrypted_extensions( ssl, buf, buf + buf_len ) );
|
|
|
|
mbedtls_ssl_tls13_add_hs_msg_to_checksum(
|
|
ssl, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS, buf, buf_len );
|
|
|
|
MBEDTLS_SSL_PROC_CHK( ssl_tls13_postprocess_encrypted_extensions( ssl ) );
|
|
|
|
cleanup:
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse encrypted extensions" ) );
|
|
return( ret );
|
|
|
|
}
|
|
|
|
/* Parse EncryptedExtensions message
|
|
* struct {
|
|
* Extension extensions<0..2^16-1>;
|
|
* } EncryptedExtensions;
|
|
*/
|
|
static int ssl_tls13_parse_encrypted_extensions( mbedtls_ssl_context *ssl,
|
|
const unsigned char *buf,
|
|
const unsigned char *end )
|
|
{
|
|
int ret = 0;
|
|
size_t extensions_len;
|
|
const unsigned char *p = buf;
|
|
const unsigned char *extensions_end;
|
|
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
|
|
extensions_len = MBEDTLS_GET_UINT16_BE( p, 0 );
|
|
p += 2;
|
|
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "encrypted extensions", p, extensions_len );
|
|
extensions_end = p + extensions_len;
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, extensions_len );
|
|
|
|
while( p < extensions_end )
|
|
{
|
|
unsigned int extension_type;
|
|
size_t extension_data_len;
|
|
|
|
/*
|
|
* struct {
|
|
* ExtensionType extension_type; (2 bytes)
|
|
* opaque extension_data<0..2^16-1>;
|
|
* } Extension;
|
|
*/
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, 4 );
|
|
extension_type = MBEDTLS_GET_UINT16_BE( p, 0 );
|
|
extension_data_len = MBEDTLS_GET_UINT16_BE( p, 2 );
|
|
p += 4;
|
|
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, extension_data_len );
|
|
|
|
/* The client MUST check EncryptedExtensions for the
|
|
* presence of any forbidden extensions and if any are found MUST abort
|
|
* the handshake with an "unsupported_extension" alert.
|
|
*/
|
|
switch( extension_type )
|
|
{
|
|
|
|
case MBEDTLS_TLS_EXT_SUPPORTED_GROUPS:
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "found extensions supported groups" ) );
|
|
break;
|
|
|
|
default:
|
|
MBEDTLS_SSL_DEBUG_MSG(
|
|
3, ( "unsupported extension found: %u ", extension_type) );
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT(
|
|
MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT,
|
|
MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION );
|
|
return ( MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION );
|
|
}
|
|
|
|
p += extension_data_len;
|
|
}
|
|
|
|
/* Check that we consumed all the message. */
|
|
if( p != end )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "EncryptedExtension lengths misaligned" ) );
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
|
|
MBEDTLS_ERR_SSL_DECODE_ERROR );
|
|
return( MBEDTLS_ERR_SSL_DECODE_ERROR );
|
|
}
|
|
|
|
return( ret );
|
|
}
|
|
|
|
static int ssl_tls13_postprocess_encrypted_extensions( mbedtls_ssl_context *ssl )
|
|
{
|
|
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
|
|
if( mbedtls_ssl_tls13_some_psk_enabled( ssl ) )
|
|
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_FINISHED );
|
|
else
|
|
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CERTIFICATE_REQUEST );
|
|
#else
|
|
((void) ssl);
|
|
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_FINISHED );
|
|
#endif
|
|
return( 0 );
|
|
}
|
|
|
|
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
|
|
/*
|
|
*
|
|
* STATE HANDLING: CertificateRequest
|
|
*
|
|
*/
|
|
#define SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST 0
|
|
#define SSL_CERTIFICATE_REQUEST_SKIP 1
|
|
/* Coordination:
|
|
* Deals with the ambiguity of not knowing if a CertificateRequest
|
|
* will be sent. Returns a negative code on failure, or
|
|
* - SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST
|
|
* - SSL_CERTIFICATE_REQUEST_SKIP
|
|
* indicating if a Certificate Request is expected or not.
|
|
*/
|
|
static int ssl_tls13_certificate_request_coordinate( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
if( mbedtls_ssl_tls13_some_psk_enabled( ssl ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "<= skip parse certificate request" ) );
|
|
return( SSL_CERTIFICATE_REQUEST_SKIP );
|
|
}
|
|
|
|
if( ( ret = mbedtls_ssl_read_record( ssl, 0 ) ) != 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_CERTIFICATE_REQUEST ) )
|
|
{
|
|
return( SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST );
|
|
}
|
|
|
|
return( SSL_CERTIFICATE_REQUEST_SKIP );
|
|
}
|
|
|
|
/*
|
|
* ssl_tls13_parse_certificate_request()
|
|
* Parse certificate request
|
|
* struct {
|
|
* opaque certificate_request_context<0..2^8-1>;
|
|
* Extension extensions<2..2^16-1>;
|
|
* } CertificateRequest;
|
|
*/
|
|
static int ssl_tls13_parse_certificate_request( mbedtls_ssl_context *ssl,
|
|
const unsigned char *buf,
|
|
const unsigned char *end )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
const unsigned char *p = buf;
|
|
size_t certificate_request_context_len = 0;
|
|
size_t extensions_len = 0;
|
|
const unsigned char *extensions_end;
|
|
unsigned char sig_alg_ext_found = 0;
|
|
|
|
/* ...
|
|
* opaque certificate_request_context<0..2^8-1>
|
|
* ...
|
|
*/
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 1 );
|
|
certificate_request_context_len = (size_t) p[0];
|
|
p += 1;
|
|
|
|
if( certificate_request_context_len > 0 )
|
|
{
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, certificate_request_context_len );
|
|
MBEDTLS_SSL_DEBUG_BUF( 3, "Certificate Request Context",
|
|
p, certificate_request_context_len );
|
|
|
|
mbedtls_ssl_handshake_params *handshake = ssl->handshake;
|
|
handshake->certificate_request_context =
|
|
mbedtls_calloc( 1, certificate_request_context_len );
|
|
if( handshake->certificate_request_context == NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
|
|
return ( MBEDTLS_ERR_SSL_ALLOC_FAILED );
|
|
}
|
|
memcpy( handshake->certificate_request_context, p,
|
|
certificate_request_context_len );
|
|
p += certificate_request_context_len;
|
|
}
|
|
|
|
/* ...
|
|
* Extension extensions<2..2^16-1>;
|
|
* ...
|
|
*/
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
|
|
extensions_len = MBEDTLS_GET_UINT16_BE( p, 0 );
|
|
p += 2;
|
|
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, extensions_len );
|
|
extensions_end = p + extensions_len;
|
|
|
|
while( p < extensions_end )
|
|
{
|
|
unsigned int extension_type;
|
|
size_t extension_data_len;
|
|
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, 4 );
|
|
extension_type = MBEDTLS_GET_UINT16_BE( p, 0 );
|
|
extension_data_len = MBEDTLS_GET_UINT16_BE( p, 2 );
|
|
p += 4;
|
|
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, extension_data_len );
|
|
|
|
switch( extension_type )
|
|
{
|
|
case MBEDTLS_TLS_EXT_SIG_ALG:
|
|
MBEDTLS_SSL_DEBUG_MSG( 3,
|
|
( "found signature algorithms extension" ) );
|
|
ret = mbedtls_ssl_tls13_parse_sig_alg_ext( ssl, p,
|
|
p + extension_data_len );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
if( ! sig_alg_ext_found )
|
|
sig_alg_ext_found = 1;
|
|
else
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 3,
|
|
( "Duplicate signature algorithms extensions found" ) );
|
|
goto decode_error;
|
|
}
|
|
break;
|
|
|
|
default:
|
|
MBEDTLS_SSL_DEBUG_MSG(
|
|
3,
|
|
( "unknown extension found: %u ( ignoring )",
|
|
extension_type ) );
|
|
break;
|
|
}
|
|
p += extension_data_len;
|
|
}
|
|
/* Check that we consumed all the message. */
|
|
if( p != end )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1,
|
|
( "CertificateRequest misaligned" ) );
|
|
goto decode_error;
|
|
}
|
|
/* Check that we found signature algorithms extension */
|
|
if( ! sig_alg_ext_found )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 3,
|
|
( "no signature algorithms extension found" ) );
|
|
goto decode_error;
|
|
}
|
|
|
|
ssl->handshake->client_auth = 1;
|
|
return( 0 );
|
|
|
|
decode_error:
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
|
|
MBEDTLS_ERR_SSL_DECODE_ERROR );
|
|
return( MBEDTLS_ERR_SSL_DECODE_ERROR );
|
|
}
|
|
|
|
/*
|
|
* Handler for MBEDTLS_SSL_CERTIFICATE_REQUEST
|
|
*/
|
|
static int ssl_tls13_process_certificate_request( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
|
|
|
|
MBEDTLS_SSL_PROC_CHK_NEG( ssl_tls13_certificate_request_coordinate( ssl ) );
|
|
|
|
if( ret == SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST )
|
|
{
|
|
unsigned char *buf;
|
|
size_t buf_len;
|
|
|
|
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_fetch_handshake_msg( ssl,
|
|
MBEDTLS_SSL_HS_CERTIFICATE_REQUEST,
|
|
&buf, &buf_len ) );
|
|
|
|
MBEDTLS_SSL_PROC_CHK( ssl_tls13_parse_certificate_request( ssl,
|
|
buf, buf + buf_len ) );
|
|
|
|
mbedtls_ssl_tls13_add_hs_msg_to_checksum(
|
|
ssl, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, buf, buf_len );
|
|
}
|
|
else if( ret == SSL_CERTIFICATE_REQUEST_SKIP )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
|
|
ret = 0;
|
|
}
|
|
else
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR;
|
|
goto cleanup;
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "got %s certificate request",
|
|
ssl->handshake->client_auth ? "a" : "no" ) );
|
|
|
|
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_CERTIFICATE );
|
|
|
|
cleanup:
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate request" ) );
|
|
return( ret );
|
|
}
|
|
|
|
/*
|
|
* Handler for MBEDTLS_SSL_SERVER_CERTIFICATE
|
|
*/
|
|
static int ssl_tls13_process_server_certificate( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret;
|
|
|
|
ret = mbedtls_ssl_tls13_process_certificate( ssl );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CERTIFICATE_VERIFY );
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Handler for MBEDTLS_SSL_CERTIFICATE_VERIFY
|
|
*/
|
|
static int ssl_tls13_process_certificate_verify( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret;
|
|
|
|
ret = mbedtls_ssl_tls13_process_certificate_verify( ssl );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_FINISHED );
|
|
return( 0 );
|
|
}
|
|
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
|
|
|
|
/*
|
|
* Handler for MBEDTLS_SSL_SERVER_FINISHED
|
|
*/
|
|
static int ssl_tls13_process_server_finished( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret;
|
|
|
|
ret = mbedtls_ssl_tls13_process_finished_message( ssl );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE)
|
|
mbedtls_ssl_handshake_set_state(
|
|
ssl,
|
|
MBEDTLS_SSL_CLIENT_CCS_AFTER_SERVER_FINISHED );
|
|
#else
|
|
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_FINISHED );
|
|
#endif
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Handler for MBEDTLS_SSL_CLIENT_CCS_AFTER_SERVER_FINISHED
|
|
*/
|
|
#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE)
|
|
static int ssl_tls13_write_change_cipher_spec( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret;
|
|
|
|
ret = mbedtls_ssl_tls13_write_change_cipher_spec( ssl );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
return( 0 );
|
|
}
|
|
#endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */
|
|
|
|
/*
|
|
* Handler for MBEDTLS_SSL_CLIENT_FINISHED
|
|
*/
|
|
static int ssl_tls13_write_client_finished( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret;
|
|
|
|
mbedtls_ssl_set_outbound_transform( ssl, ssl->handshake->transform_handshake );
|
|
|
|
ret = mbedtls_ssl_tls13_write_finished_message( ssl );
|
|
if( ret != 0 )
|
|
return( ret );
|
|
|
|
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_FLUSH_BUFFERS );
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Handler for MBEDTLS_SSL_FLUSH_BUFFERS
|
|
*/
|
|
static int ssl_tls13_flush_buffers( mbedtls_ssl_context *ssl )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "handshake: done" ) );
|
|
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_HANDSHAKE_WRAPUP );
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Handler for MBEDTLS_SSL_HANDSHAKE_WRAPUP
|
|
*/
|
|
static int ssl_tls13_handshake_wrapup( mbedtls_ssl_context *ssl )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Switch to application keys for inbound traffic" ) );
|
|
mbedtls_ssl_set_inbound_transform ( ssl, ssl->transform_application );
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "Switch to application keys for outbound traffic" ) );
|
|
mbedtls_ssl_set_outbound_transform( ssl, ssl->transform_application );
|
|
|
|
mbedtls_ssl_tls13_handshake_wrapup( ssl );
|
|
|
|
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_HANDSHAKE_OVER );
|
|
return( 0 );
|
|
}
|
|
|
|
int mbedtls_ssl_tls13_handshake_client_step( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = 0;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "tls13 client state: %s(%d)",
|
|
mbedtls_ssl_states_str( ssl->state ),
|
|
ssl->state ) );
|
|
|
|
switch( ssl->state )
|
|
{
|
|
/*
|
|
* ssl->state is initialized as HELLO_REQUEST. It is the same
|
|
* as CLIENT_HELLO state.
|
|
*/
|
|
case MBEDTLS_SSL_HELLO_REQUEST:
|
|
case MBEDTLS_SSL_CLIENT_HELLO:
|
|
ret = ssl_tls13_write_client_hello( ssl );
|
|
break;
|
|
|
|
case MBEDTLS_SSL_SERVER_HELLO:
|
|
ret = ssl_tls13_process_server_hello( ssl );
|
|
break;
|
|
|
|
case MBEDTLS_SSL_ENCRYPTED_EXTENSIONS:
|
|
ret = ssl_tls13_process_encrypted_extensions( ssl );
|
|
break;
|
|
|
|
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
|
|
case MBEDTLS_SSL_CERTIFICATE_REQUEST:
|
|
ret = ssl_tls13_process_certificate_request( ssl );
|
|
break;
|
|
|
|
case MBEDTLS_SSL_SERVER_CERTIFICATE:
|
|
ret = ssl_tls13_process_server_certificate( ssl );
|
|
break;
|
|
|
|
case MBEDTLS_SSL_CERTIFICATE_VERIFY:
|
|
ret = ssl_tls13_process_certificate_verify( ssl );
|
|
break;
|
|
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
|
|
|
|
case MBEDTLS_SSL_SERVER_FINISHED:
|
|
ret = ssl_tls13_process_server_finished( ssl );
|
|
break;
|
|
|
|
case MBEDTLS_SSL_CLIENT_FINISHED:
|
|
ret = ssl_tls13_write_client_finished( ssl );
|
|
break;
|
|
|
|
case MBEDTLS_SSL_FLUSH_BUFFERS:
|
|
ret = ssl_tls13_flush_buffers( ssl );
|
|
break;
|
|
|
|
case MBEDTLS_SSL_HANDSHAKE_WRAPUP:
|
|
ret = ssl_tls13_handshake_wrapup( ssl );
|
|
break;
|
|
|
|
/*
|
|
* Injection of dummy-CCS's for middlebox compatibility
|
|
*/
|
|
#if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE)
|
|
case MBEDTLS_SSL_CLIENT_CCS_AFTER_SERVER_FINISHED:
|
|
case MBEDTLS_SSL_CLIENT_CCS_BEFORE_2ND_CLIENT_HELLO:
|
|
ret = ssl_tls13_write_change_cipher_spec( ssl );
|
|
break;
|
|
#endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */
|
|
|
|
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 */
|
|
|
|
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
|