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			922 lines
		
	
	
		
			29 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			922 lines
		
	
	
		
			29 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  *  TLS 1.3 client-side functions
 | |
|  *
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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
 | |
|  *  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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|  *  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
 | |
|  *  limitations under the License.
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|  *
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|  *  This file is part of mbed TLS ( https://tls.mbed.org )
 | |
|  */
 | |
| 
 | |
| #include "common.h"
 | |
| 
 | |
| #if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
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| 
 | |
| #if defined(MBEDTLS_SSL_CLI_C)
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| 
 | |
| #include <string.h>
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| 
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| #include "mbedtls/debug.h"
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| #include "mbedtls/error.h"
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| 
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| #include "ssl_misc.h"
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| #include "ecdh_misc.h"
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| 
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| #define CLIENT_HELLO_RANDOM_LEN 32
 | |
| 
 | |
| /* Write extensions */
 | |
| 
 | |
| /*
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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;
 | |
|  */
 | |
| static int ssl_tls13_write_supported_versions_ext( mbedtls_ssl_context *ssl,
 | |
|                                                    unsigned char *buf,
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|                                                    unsigned char *end,
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|                                                    size_t *olen )
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| {
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|     unsigned char *p = buf;
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| 
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|     *olen = 0;
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| 
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|     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported versions extension" ) );
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| 
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|     /* Check if we have space to write the extension:
 | |
|      * - 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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| 
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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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| 
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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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| 
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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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|     mbedtls_ssl_write_version( ssl->conf->max_major_ver,
 | |
|                                ssl->conf->max_minor_ver,
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|                                ssl->conf->transport, p );
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| 
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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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| 
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|     *olen = 7;
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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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|  * Functions for writing supported_groups extension.
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|  *
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|  * Stucture of supported_groups:
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|  *      enum {
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|  *          secp256r1(0x0017), secp384r1(0x0018), secp521r1(0x0019),
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|  *          x25519(0x001D), x448(0x001E),
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|  *          ffdhe2048(0x0100), ffdhe3072(0x0101), ffdhe4096(0x0102),
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|  *          ffdhe6144(0x0103), ffdhe8192(0x0104),
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|  *          ffdhe_private_use(0x01FC..0x01FF),
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|  *          ecdhe_private_use(0xFE00..0xFEFF),
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|  *          (0xFFFF)
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|  *      } NamedGroup;
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|  *      struct {
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|  *          NamedGroup named_group_list<2..2^16-1>;
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|  *      } NamedGroupList;
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|  */
 | |
| #if defined(MBEDTLS_ECDH_C)
 | |
| /*
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|  * In versions of TLS prior to TLS 1.3, this extension was named
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|  * 'elliptic_curves' and only contained elliptic curve groups.
 | |
|  */
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| static int ssl_tls13_write_named_group_list_ecdhe( mbedtls_ssl_context *ssl,
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|                                             unsigned char *buf,
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|                                             unsigned char *end,
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|                                             size_t *olen )
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| {
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|     unsigned char *p = buf;
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| 
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|     *olen = 0;
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| 
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|     if( ssl->conf->curve_list == NULL )
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|         return( MBEDTLS_ERR_SSL_BAD_CONFIG );
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| 
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|     for ( const mbedtls_ecp_group_id *grp_id = ssl->conf->curve_list;
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|           *grp_id != MBEDTLS_ECP_DP_NONE;
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|           grp_id++ )
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|     {
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|         const mbedtls_ecp_curve_info *info;
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|         info = mbedtls_ecp_curve_info_from_grp_id( *grp_id );
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|         if( info == NULL )
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|             continue;
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| 
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|         if( !mbedtls_ssl_tls13_named_group_is_ecdhe( info->tls_id ) )
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|             continue;
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| 
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|         MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2);
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|         MBEDTLS_PUT_UINT16_BE( info->tls_id, p, 0 );
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|         p += 2;
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| 
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|         MBEDTLS_SSL_DEBUG_MSG( 3, ( "NamedGroup: %s ( %x )",
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|                   mbedtls_ecp_curve_info_from_tls_id( info->tls_id )->name,
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|                   info->tls_id ) );
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|     }
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| 
 | |
|     *olen = p - buf;
 | |
| 
 | |
|     return( 0 );
 | |
| }
 | |
| #else
 | |
| static int ssl_tls13_write_named_group_list_ecdhe( mbedtls_ssl_context *ssl,
 | |
|                                             unsigned char *buf,
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|                                             unsigned char *end,
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|                                             size_t *olen )
 | |
| {
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|     ((void) ssl);
 | |
|     ((void) buf);
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|     ((void) end);
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|     *olen = 0;
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|     return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
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| }
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| #endif /* MBEDTLS_ECDH_C */
 | |
| 
 | |
| static int ssl_tls13_write_named_group_list_dhe( mbedtls_ssl_context *ssl,
 | |
|                                         unsigned char *buf,
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|                                         unsigned char *end,
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|                                         size_t *olen )
 | |
| {
 | |
|     ((void) ssl);
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|     ((void) buf);
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|     ((void) end);
 | |
|     *olen = 0;
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|     MBEDTLS_SSL_DEBUG_MSG( 3, ( "write_named_group_dhe is not implemented" ) );
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|     return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
 | |
| }
 | |
| 
 | |
| static int ssl_tls13_write_supported_groups_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 *olen )
 | |
| {
 | |
|     unsigned char *p = buf ;
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|     unsigned char *named_group_list_ptr; /* Start of named_group_list */
 | |
|     size_t named_group_list_len;         /* Length of named_group_list */
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|     size_t output_len = 0;
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|     int ret_ecdhe, ret_dhe;
 | |
| 
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|     *olen = 0;
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| 
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|     if( !mbedtls_ssl_conf_tls13_some_ephemeral_enabled( ssl ) )
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|         return( 0 );
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| 
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|     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported_groups extension" ) );
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| 
 | |
|     /* Check if we have space for header and length fields:
 | |
|      * - extension_type         (2 bytes)
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|      * - extension_data_length  (2 bytes)
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|      * - named_group_list_length   (2 bytes)
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|      */
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|     MBEDTLS_SSL_CHK_BUF_PTR( p, end, 6 );
 | |
|     p += 6;
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| 
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|     named_group_list_ptr = p;
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|     ret_ecdhe = ssl_tls13_write_named_group_list_ecdhe( ssl, p, end, &output_len );
 | |
|     if( ret_ecdhe != 0 )
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|     {
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|         MBEDTLS_SSL_DEBUG_RET( 1, "ssl_tls13_write_named_group_list_ecdhe", ret_ecdhe );
 | |
|     }
 | |
|     p += output_len;
 | |
| 
 | |
|     ret_dhe = ssl_tls13_write_named_group_list_dhe( ssl, p, end, &output_len );
 | |
|     if( ret_dhe != 0 )
 | |
|     {
 | |
|         MBEDTLS_SSL_DEBUG_RET( 1, "ssl_tls13_write_named_group_list_dhe", ret_dhe );
 | |
|     }
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|     p += output_len;
 | |
| 
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|     /* Both ECDHE and DHE failed. */
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|     if( ret_ecdhe != 0 && ret_dhe != 0 )
 | |
|     {
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|         MBEDTLS_SSL_DEBUG_MSG( 1, ( "Both ECDHE and DHE groups are fail. " ) );
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|         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
 | |
|     }
 | |
| 
 | |
|     /* Length of named_group_list*/
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|     named_group_list_len = p - named_group_list_ptr;
 | |
|     if( named_group_list_len == 0 )
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|     {
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|         MBEDTLS_SSL_DEBUG_MSG( 1, ( "No group available." ) );
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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_SUPPORTED_GROUPS, buf, 0 );
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|     /* Write extension_data_length */
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|     MBEDTLS_PUT_UINT16_BE( named_group_list_len + 2, buf, 2 );
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|     /* Write length of named_group_list */
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|     MBEDTLS_PUT_UINT16_BE( named_group_list_len, buf, 4 );
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| 
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|     MBEDTLS_SSL_DEBUG_BUF( 3, "Supported groups extension", buf + 4, named_group_list_len + 2 );
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| 
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|     *olen = p - buf;
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| 
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|     ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_SUPPORTED_GROUPS;
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| 
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|     return( 0 );
 | |
| }
 | |
| 
 | |
| /*
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|  * Functions for writing key_share extension.
 | |
|  */
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| #if defined(MBEDTLS_ECDH_C)
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| static int ssl_tls13_generate_and_write_ecdh_key_exchange(
 | |
|                 mbedtls_ssl_context *ssl,
 | |
|                 uint16_t named_group,
 | |
|                 unsigned char *buf,
 | |
|                 unsigned char *end,
 | |
|                 size_t *olen )
 | |
| {
 | |
|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 | |
|     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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| 
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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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|     ret = mbedtls_ecdh_tls13_make_params( &ssl->handshake->ecdh_ctx, olen,
 | |
|                                            buf, end - buf,
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|                                            ssl->conf->f_rng, ssl->conf->p_rng );
 | |
|     if( ret != 0 )
 | |
|     {
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|         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_tls13_make_params", ret );
 | |
|         return( ret );
 | |
|     }
 | |
| 
 | |
|     MBEDTLS_SSL_DEBUG_ECDH( 3, &ssl->handshake->ecdh_ctx,
 | |
|                             MBEDTLS_DEBUG_ECDH_Q );
 | |
|     return( 0 );
 | |
| }
 | |
| #endif /* MBEDTLS_ECDH_C */
 | |
| 
 | |
| static int ssl_tls13_get_default_group_id( mbedtls_ssl_context *ssl,
 | |
|                                            uint16_t *group_id )
 | |
| {
 | |
|     int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
 | |
| 
 | |
| 
 | |
| #if defined(MBEDTLS_ECDH_C)
 | |
|     /* Pick first available ECDHE group compatible with TLS 1.3 */
 | |
|     if( ssl->conf->curve_list == NULL )
 | |
|         return( MBEDTLS_ERR_SSL_BAD_CONFIG );
 | |
| 
 | |
|     for ( const mbedtls_ecp_group_id *grp_id = ssl->conf->curve_list;
 | |
|           *grp_id != MBEDTLS_ECP_DP_NONE;
 | |
|           grp_id++ )
 | |
|     {
 | |
|         const mbedtls_ecp_curve_info *info;
 | |
|         info = mbedtls_ecp_curve_info_from_grp_id( *grp_id );
 | |
|         if( info != NULL &&
 | |
|             mbedtls_ssl_tls13_named_group_is_ecdhe( info->tls_id ) )
 | |
|         {
 | |
|             *group_id = info->tls_id;
 | |
|             return( 0 );
 | |
|         }
 | |
|     }
 | |
| #else
 | |
|     ((void) ssl);
 | |
|     ((void) group_id);
 | |
| #endif /* MBEDTLS_ECDH_C */
 | |
| 
 | |
|     /*
 | |
|      * Add DHE named groups here.
 | |
|      * Pick first available DHE group compatible with TLS 1.3
 | |
|      */
 | |
| 
 | |
|     return( ret );
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * ssl_tls13_write_key_share_ext
 | |
|  *
 | |
|  * Structure of key_share extension in ClientHello:
 | |
|  *
 | |
|  *  struct {
 | |
|  *          NamedGroup group;
 | |
|  *          opaque key_exchange<1..2^16-1>;
 | |
|  *      } KeyShareEntry;
 | |
|  *  struct {
 | |
|  *          KeyShareEntry client_shares<0..2^16-1>;
 | |
|  *      } KeyShareClientHello;
 | |
|  */
 | |
| static int ssl_tls13_write_key_share_ext( mbedtls_ssl_context *ssl,
 | |
|                                           unsigned char *buf,
 | |
|                                           unsigned char *end,
 | |
|                                           size_t *olen )
 | |
| {
 | |
|     unsigned char *p = buf;
 | |
|     unsigned char *client_shares_ptr; /* Start of client_shares */
 | |
|     size_t client_shares_len;         /* Length of client_shares */
 | |
|     uint16_t group_id;
 | |
|     int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
 | |
| 
 | |
|     *olen = 0;
 | |
| 
 | |
|     if( !mbedtls_ssl_conf_tls13_some_ephemeral_enabled( ssl ) )
 | |
|         return( 0 );
 | |
| 
 | |
|     /* Check if we have space for header and length fields:
 | |
|      * - extension_type         (2 bytes)
 | |
|      * - extension_data_length  (2 bytes)
 | |
|      * - client_shares_length   (2 bytes)
 | |
|      */
 | |
|     MBEDTLS_SSL_CHK_BUF_PTR( p, end, 6 );
 | |
|     p += 6;
 | |
| 
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello: adding key share extension" ) );
 | |
| 
 | |
|     /* HRR could already have requested something else. */
 | |
|     group_id = ssl->handshake->offered_group_id;
 | |
|     if( !mbedtls_ssl_tls13_named_group_is_ecdhe( group_id ) &&
 | |
|         !mbedtls_ssl_tls13_named_group_is_dhe( group_id ) )
 | |
|     {
 | |
|         MBEDTLS_SSL_PROC_CHK( ssl_tls13_get_default_group_id( ssl,
 | |
|                                                               &group_id ) );
 | |
|     }
 | |
| 
 | |
|     /*
 | |
|      * Dispatch to type-specific key generation function.
 | |
|      *
 | |
|      * So far, we're only supporting ECDHE. With the introduction
 | |
|      * of PQC KEMs, we'll want to have multiple branches, one per
 | |
|      * type of KEM, and dispatch to the corresponding crypto. And
 | |
|      * only one key share entry is allowed.
 | |
|      */
 | |
|     client_shares_ptr = p;
 | |
| #if defined(MBEDTLS_ECDH_C)
 | |
|     if( mbedtls_ssl_tls13_named_group_is_ecdhe( group_id ) )
 | |
|     {
 | |
|         /* Pointer to group */
 | |
|         unsigned char *group_ptr = p;
 | |
|         /* Length of key_exchange */
 | |
|         size_t key_exchange_len;
 | |
| 
 | |
|         /* Check there is space for header of KeyShareEntry
 | |
|          * - group                  (2 bytes)
 | |
|          * - key_exchange_length    (2 bytes)
 | |
|          */
 | |
|         MBEDTLS_SSL_CHK_BUF_PTR( p, end, 4 );
 | |
|         p += 4;
 | |
|         ret = ssl_tls13_generate_and_write_ecdh_key_exchange( ssl, group_id,
 | |
|                                                               p, end,
 | |
|                                                               &key_exchange_len );
 | |
|         p += key_exchange_len;
 | |
|         if( ret != 0 )
 | |
|             return( ret );
 | |
| 
 | |
|         /* Write group */
 | |
|         MBEDTLS_PUT_UINT16_BE( group_id, group_ptr, 0 );
 | |
|         /* Write key_exchange_length */
 | |
|         MBEDTLS_PUT_UINT16_BE( key_exchange_len, group_ptr, 2 );
 | |
|     }
 | |
|     else
 | |
| #endif /* MBEDTLS_ECDH_C */
 | |
|     if( 0 /* other KEMs? */ )
 | |
|     {
 | |
|         /* Do something */
 | |
|     }
 | |
|     else
 | |
|         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
 | |
| 
 | |
|     /* Length of client_shares */
 | |
|     client_shares_len = p - client_shares_ptr;
 | |
|     if( client_shares_len == 0)
 | |
|     {
 | |
|         MBEDTLS_SSL_DEBUG_MSG( 1, ( "No key share defined." ) );
 | |
|         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
 | |
|     }
 | |
|     /* Write extension_type */
 | |
|     MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_KEY_SHARE, buf, 0 );
 | |
|     /* Write extension_data_length */
 | |
|     MBEDTLS_PUT_UINT16_BE( client_shares_len + 2, buf, 2 );
 | |
|     /* Write client_shares_length */
 | |
|     MBEDTLS_PUT_UINT16_BE( client_shares_len, buf, 4 );
 | |
| 
 | |
|     /* Update offered_group_id field */
 | |
|     ssl->handshake->offered_group_id = group_id;
 | |
| 
 | |
|     /* Output the total length of key_share extension. */
 | |
|     *olen = p - buf;
 | |
| 
 | |
|     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, key_share extension", buf, *olen );
 | |
| 
 | |
|     ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_KEY_SHARE;
 | |
| 
 | |
| cleanup:
 | |
| 
 | |
|     return( ret );
 | |
| }
 | |
| 
 | |
| #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
 | |
| 
 | |
| /* 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 *olen )
 | |
| {
 | |
|     unsigned char *p = buf;
 | |
|     const int *ciphersuite_list;
 | |
|     unsigned char *cipher_suites_ptr; /* Start of the cipher_suites list */
 | |
|     size_t cipher_suites_len;
 | |
| 
 | |
|     *olen = 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_ptr = 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_ptr;
 | |
|     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. */
 | |
|     *olen = 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 *olen )
 | |
| {
 | |
| 
 | |
|     int ret;
 | |
|     unsigned char *extensions_len_ptr; /* 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;
 | |
| 
 | |
|     *olen = 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, CLIENT_HELLO_RANDOM_LEN );
 | |
|     memcpy( p, ssl->handshake->randbytes, CLIENT_HELLO_RANDOM_LEN );
 | |
|     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes",
 | |
|                            p, CLIENT_HELLO_RANDOM_LEN );
 | |
|     p += 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 ).
 | |
|      */
 | |
|     MBEDTLS_SSL_CHK_BUF_PTR( p, end, 1 );
 | |
|     *p++ = 0; /* session id length set to zero */
 | |
| 
 | |
|     /* 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 );
 | |
|     extensions_len_ptr = 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)
 | |
|     /* Write supported_groups extension
 | |
|      *
 | |
|      * It is REQUIRED for ECDHE cipher_suites.
 | |
|      */
 | |
|     ret = ssl_tls13_write_supported_groups_ext( ssl, p, end, &output_len );
 | |
|     if( ret != 0 )
 | |
|         return( ret );
 | |
|     p += output_len;
 | |
| 
 | |
|     /* Write key_share extension
 | |
|      *
 | |
|      * We need to send the key shares under three conditions:
 | |
|      * 1) A certificate-based ciphersuite is being offered. In this case
 | |
|      *    supported_groups and supported_signature extensions have been
 | |
|      *    successfully added.
 | |
|      * 2) A PSK-based ciphersuite with ECDHE is offered. In this case the
 | |
|      *    psk_key_exchange_modes has been added as the last extension.
 | |
|      * 3) Or, in case all ciphers are supported ( which includes #1 and #2
 | |
|      *    from above )
 | |
|      */
 | |
|     ret = ssl_tls13_write_key_share_ext( ssl, p, end, &output_len );
 | |
|     if( ret != 0 )
 | |
|         return( ret );
 | |
|     p += output_len;
 | |
| 
 | |
|     /* Write signature_algorithms extension
 | |
|      *
 | |
|      * It is REQUIRED for certificate authenticated cipher_suites.
 | |
|      */
 | |
|     ret = mbedtls_ssl_tls13_write_sig_alg_ext( ssl, p, end, &output_len );
 | |
|     if( ret != 0 )
 | |
|         return( ret );
 | |
|     p += output_len;
 | |
| 
 | |
| #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
 | |
| 
 | |
|     /* Add more extensions here */
 | |
| 
 | |
|     /* Write the length of the list of extensions. */
 | |
|     extensions_len = p - extensions_len_ptr - 2;
 | |
|     MBEDTLS_PUT_UINT16_BE( extensions_len, extensions_len_ptr, 0 );
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, total extension length: %" MBEDTLS_PRINTF_SIZET ,
 | |
|                                 extensions_len ) );
 | |
|     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello extensions", extensions_len_ptr, extensions_len );
 | |
| 
 | |
|     *olen = 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,
 | |
|                                   CLIENT_HELLO_RANDOM_LEN ) ) != 0 )
 | |
|     {
 | |
|         MBEDTLS_SSL_DEBUG_RET( 1, "f_rng", ret );
 | |
|         return( ret );
 | |
|     }
 | |
| 
 | |
|     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;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Handler for MBEDTLS_SSL_SERVER_HELLO
 | |
|  */
 | |
| static int ssl_tls1_3_process_server_hello( mbedtls_ssl_context *ssl )
 | |
| {
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
 | |
|     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_ENCRYPTED_EXTENSIONS );
 | |
|     return( 0 );
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Handler for MBEDTLS_SSL_ENCRYPTED_EXTENSIONS
 | |
|  */
 | |
| static int ssl_tls1_3_process_encrypted_extensions( mbedtls_ssl_context *ssl )
 | |
| {
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
 | |
|     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CERTIFICATE_REQUEST );
 | |
|     return( 0 );
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Handler for  MBEDTLS_SSL_CERTIFICATE_REQUEST
 | |
|  */
 | |
| static int ssl_tls1_3_process_certificate_request( mbedtls_ssl_context *ssl )
 | |
| {
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
 | |
|     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_CERTIFICATE );
 | |
|     return( 0 );
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Handler for MBEDTLS_SSL_SERVER_CERTIFICATE
 | |
|  */
 | |
| static int ssl_tls1_3_process_server_certificate( mbedtls_ssl_context *ssl )
 | |
| {
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
 | |
|     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CERTIFICATE_VERIFY );
 | |
|     return( 0 );
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Handler for MBEDTLS_SSL_CERTIFICATE_VERIFY
 | |
|  */
 | |
| static int ssl_tls1_3_process_certificate_verify( mbedtls_ssl_context *ssl )
 | |
| {
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
 | |
|     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_FINISHED );
 | |
|     return( 0 );
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Handler for MBEDTLS_SSL_SERVER_FINISHED
 | |
|  */
 | |
| static int ssl_tls1_3_process_server_finished( mbedtls_ssl_context *ssl )
 | |
| {
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
 | |
|     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE );
 | |
|     return( 0 );
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Handler for MBEDTLS_SSL_CLIENT_CERTIFICATE
 | |
|  */
 | |
| static int ssl_tls1_3_write_client_certificate( mbedtls_ssl_context *ssl )
 | |
| {
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
 | |
|     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY );
 | |
|     return( 0 );
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Handler for MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY
 | |
|  */
 | |
| static int ssl_tls1_3_write_client_certificate_verify( mbedtls_ssl_context *ssl )
 | |
| {
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
 | |
|     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_FINISHED );
 | |
|     return( 0 );
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Handler for MBEDTLS_SSL_CLIENT_FINISHED
 | |
|  */
 | |
| static int ssl_tls1_3_write_client_finished( mbedtls_ssl_context *ssl )
 | |
| {
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
 | |
|     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_FLUSH_BUFFERS );
 | |
|     return( 0 );
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Handler for MBEDTLS_SSL_FLUSH_BUFFERS
 | |
|  */
 | |
| static int ssl_tls1_3_flush_buffers( mbedtls_ssl_context *ssl )
 | |
| {
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
 | |
|     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_HANDSHAKE_WRAPUP );
 | |
|     return( 0 );
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Handler for MBEDTLS_SSL_HANDSHAKE_WRAPUP
 | |
|  */
 | |
| static int ssl_tls1_3_handshake_wrapup( mbedtls_ssl_context *ssl )
 | |
| {
 | |
|     ((void) ssl);
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
 | |
|     return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
 | |
| }
 | |
| 
 | |
| int mbedtls_ssl_tls13_handshake_client_step( mbedtls_ssl_context *ssl )
 | |
| {
 | |
|     int ret = 0;
 | |
| 
 | |
|     MBEDTLS_SSL_DEBUG_MSG( 2, ( "tls1_3 client state: %d", 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_tls1_3_process_server_hello( ssl );
 | |
|             break;
 | |
| 
 | |
|         case MBEDTLS_SSL_ENCRYPTED_EXTENSIONS:
 | |
|             ret = ssl_tls1_3_process_encrypted_extensions( ssl );
 | |
|             break;
 | |
| 
 | |
|         case MBEDTLS_SSL_CERTIFICATE_REQUEST:
 | |
|             ret = ssl_tls1_3_process_certificate_request( ssl );
 | |
|             break;
 | |
| 
 | |
|         case MBEDTLS_SSL_SERVER_CERTIFICATE:
 | |
|             ret = ssl_tls1_3_process_server_certificate( ssl );
 | |
|             break;
 | |
| 
 | |
|         case MBEDTLS_SSL_CERTIFICATE_VERIFY:
 | |
|             ret = ssl_tls1_3_process_certificate_verify( ssl );
 | |
|             break;
 | |
| 
 | |
|         case MBEDTLS_SSL_SERVER_FINISHED:
 | |
|             ret = ssl_tls1_3_process_server_finished( ssl );
 | |
|             break;
 | |
| 
 | |
|         case MBEDTLS_SSL_CLIENT_CERTIFICATE:
 | |
|             ret = ssl_tls1_3_write_client_certificate( ssl );
 | |
|             break;
 | |
| 
 | |
|         case MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY:
 | |
|             ret = ssl_tls1_3_write_client_certificate_verify( ssl );
 | |
|             break;
 | |
| 
 | |
|         case MBEDTLS_SSL_CLIENT_FINISHED:
 | |
|             ret = ssl_tls1_3_write_client_finished( ssl );
 | |
|             break;
 | |
| 
 | |
|         case MBEDTLS_SSL_FLUSH_BUFFERS:
 | |
|             ret = ssl_tls1_3_flush_buffers( ssl );
 | |
|             break;
 | |
| 
 | |
|         case MBEDTLS_SSL_HANDSHAKE_WRAPUP:
 | |
|             ret = ssl_tls1_3_handshake_wrapup( ssl );
 | |
|             break;
 | |
| 
 | |
|         default:
 | |
|             MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) );
 | |
|             return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
 | |
|     }
 | |
| 
 | |
|     return( ret );
 | |
| }
 | |
| 
 | |
| #endif /* MBEDTLS_SSL_CLI_C */
 | |
| 
 | |
| #endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
 |