| /* |
| * TLS 1.3 client-side functions |
| * |
| * Copyright The Mbed TLS Contributors |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| * not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| * This file is part of mbed TLS ( https://tls.mbed.org ) |
| */ |
| |
| #include "common.h" |
| |
| #if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL) |
| |
| #if defined(MBEDTLS_SSL_CLI_C) |
| |
| #include <string.h> |
| |
| #include "mbedtls/debug.h" |
| #include "mbedtls/error.h" |
| |
| #include "ssl_misc.h" |
| #include "ecdh_misc.h" |
| |
| #define CLIENT_HELLO_RANDOM_LEN 32 |
| |
| /* Write extensions */ |
| |
| /* |
| * ssl_tls13_write_supported_versions_ext(): |
| * |
| * struct { |
| * ProtocolVersion versions<2..254>; |
| * } SupportedVersions; |
| */ |
| static int ssl_tls13_write_supported_versions_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| unsigned char *end, |
| size_t *olen ) |
| { |
| unsigned char *p = buf; |
| |
| *olen = 0; |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported versions extension" ) ); |
| |
| /* Check if we have space to write the extension: |
| * - extension_type (2 bytes) |
| * - extension_data_length (2 bytes) |
| * - versions_length (1 byte ) |
| * - versions (2 bytes) |
| */ |
| MBEDTLS_SSL_CHK_BUF_PTR( p, end, 7 ); |
| |
| /* Write extension_type */ |
| MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS, p, 0 ); |
| |
| /* Write extension_data_length */ |
| MBEDTLS_PUT_UINT16_BE( 3, p, 2 ); |
| p += 4; |
| |
| /* Length of versions */ |
| *p++ = 0x2; |
| |
| /* Write values of supported versions. |
| * |
| * They are defined by the configuration. |
| * |
| * Currently, only one version is advertised. |
| */ |
| mbedtls_ssl_write_version( ssl->conf->max_major_ver, |
| ssl->conf->max_minor_ver, |
| ssl->conf->transport, p ); |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "supported version: [%d:%d]", |
| ssl->conf->max_major_ver, |
| ssl->conf->max_minor_ver ) ); |
| |
| *olen = 7; |
| |
| return( 0 ); |
| } |
| |
| #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) |
| |
| /* |
| * Functions for writing supported_groups extension. |
| * |
| * Stucture of supported_groups: |
| * enum { |
| * secp256r1(0x0017), secp384r1(0x0018), secp521r1(0x0019), |
| * x25519(0x001D), x448(0x001E), |
| * ffdhe2048(0x0100), ffdhe3072(0x0101), ffdhe4096(0x0102), |
| * ffdhe6144(0x0103), ffdhe8192(0x0104), |
| * ffdhe_private_use(0x01FC..0x01FF), |
| * ecdhe_private_use(0xFE00..0xFEFF), |
| * (0xFFFF) |
| * } NamedGroup; |
| * struct { |
| * NamedGroup named_group_list<2..2^16-1>; |
| * } NamedGroupList; |
| */ |
| #if defined(MBEDTLS_ECDH_C) |
| /* |
| * In versions of TLS prior to TLS 1.3, this extension was named |
| * 'elliptic_curves' and only contained elliptic curve groups. |
| */ |
| static int ssl_tls13_write_named_group_list_ecdhe( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| unsigned char *end, |
| size_t *olen ) |
| { |
| unsigned char *p = buf; |
| |
| *olen = 0; |
| |
| 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 ) |
| continue; |
| |
| if( !mbedtls_ssl_tls13_named_group_is_ecdhe( info->tls_id ) ) |
| continue; |
| |
| MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2); |
| MBEDTLS_PUT_UINT16_BE( info->tls_id, p, 0 ); |
| p += 2; |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "NamedGroup: %s ( %x )", |
| mbedtls_ecp_curve_info_from_tls_id( info->tls_id )->name, |
| info->tls_id ) ); |
| } |
| |
| *olen = p - buf; |
| |
| return( 0 ); |
| } |
| #else |
| static int ssl_tls13_write_named_group_list_ecdhe( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| unsigned char *end, |
| size_t *olen ) |
| { |
| ((void) ssl); |
| ((void) buf); |
| ((void) end); |
| *olen = 0; |
| return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); |
| } |
| #endif /* MBEDTLS_ECDH_C */ |
| |
| static int ssl_tls13_write_named_group_list_dhe( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| unsigned char *end, |
| size_t *olen ) |
| { |
| ((void) ssl); |
| ((void) buf); |
| ((void) end); |
| *olen = 0; |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "write_named_group_dhe is not implemented" ) ); |
| return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE ); |
| } |
| |
| static int ssl_tls13_write_supported_groups_ext( mbedtls_ssl_context *ssl, |
| unsigned char *buf, |
| unsigned char *end, |
| size_t *olen ) |
| { |
| unsigned char *p = buf ; |
| unsigned char *named_group_list_ptr; /* Start of named_group_list */ |
| size_t named_group_list_len; /* Length of named_group_list */ |
| size_t output_len = 0; |
| int ret_ecdhe, ret_dhe; |
| |
| *olen = 0; |
| |
| if( !mbedtls_ssl_conf_tls13_some_ephemeral_enabled( ssl ) ) |
| return( 0 ); |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported_groups extension" ) ); |
| |
| /* Check if we have space for header and length fields: |
| * - extension_type (2 bytes) |
| * - extension_data_length (2 bytes) |
| * - named_group_list_length (2 bytes) |
| */ |
| MBEDTLS_SSL_CHK_BUF_PTR( p, end, 6 ); |
| p += 6; |
| |
| named_group_list_ptr = p; |
| ret_ecdhe = ssl_tls13_write_named_group_list_ecdhe( ssl, p, end, &output_len ); |
| if( ret_ecdhe != 0 ) |
| { |
| 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 ); |
| } |
| p += output_len; |
| |
| /* Both ECDHE and DHE failed. */ |
| if( ret_ecdhe != 0 && ret_dhe != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "Both ECDHE and DHE groups are fail. " ) ); |
| return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); |
| } |
| |
| /* Length of named_group_list*/ |
| named_group_list_len = p - named_group_list_ptr; |
| if( named_group_list_len == 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_MSG( 1, ( "No group available." ) ); |
| return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); |
| } |
| |
| /* Write extension_type */ |
| MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_SUPPORTED_GROUPS, buf, 0 ); |
| /* Write extension_data_length */ |
| MBEDTLS_PUT_UINT16_BE( named_group_list_len + 2, buf, 2 ); |
| /* Write length of named_group_list */ |
| MBEDTLS_PUT_UINT16_BE( named_group_list_len, buf, 4 ); |
| |
| MBEDTLS_SSL_DEBUG_BUF( 3, "Supported groups extension", buf + 4, named_group_list_len + 2 ); |
| |
| *olen = p - buf; |
| |
| ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_SUPPORTED_GROUPS; |
| |
| return( 0 ); |
| } |
| |
| /* |
| * Functions for writing key_share extension. |
| */ |
| #if defined(MBEDTLS_ECDH_C) |
| 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 = |
| mbedtls_ecp_curve_info_from_tls_id( named_group ); |
| |
| if( curve_info == NULL ) |
| return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); |
| |
| MBEDTLS_SSL_DEBUG_MSG( 3, ( "offer curve %s", curve_info->name ) ); |
| |
| if( ( ret = mbedtls_ecdh_setup_no_everest( &ssl->handshake->ecdh_ctx, |
| curve_info->grp_id ) ) != 0 ) |
| { |
| MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_setup_no_everest", ret ); |
| return( ret ); |
| } |
| |
| ret = mbedtls_ecdh_tls13_make_params( &ssl->handshake->ecdh_ctx, olen, |
| buf, end - buf, |
| ssl->conf->f_rng, ssl->conf->p_rng ); |
| if( ret != 0 ) |
| { |
| 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 */ |