850 lines
29 KiB
C
850 lines
29 KiB
C
/*
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* TLS 1.3 functionality shared between client and server
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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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#include "common.h"
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#if defined(MBEDTLS_SSL_TLS_C)
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#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
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#include <string.h>
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#include "mbedtls/error.h"
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#include "mbedtls/debug.h"
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#include "mbedtls/oid.h"
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#include "mbedtls/platform.h"
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#include "ssl_misc.h"
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#include "ssl_tls13_keys.h"
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int mbedtls_ssl_tls1_3_fetch_handshake_msg( mbedtls_ssl_context *ssl,
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unsigned hs_type,
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unsigned char **buf,
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size_t *buflen )
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{
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int ret;
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if( ( ret = mbedtls_ssl_read_record( ssl, 0 ) ) != 0 )
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{
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MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
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goto cleanup;
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}
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if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ||
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ssl->in_msg[0] != hs_type )
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{
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "Receive unexpected handshake message." ) );
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MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE,
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MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
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ret = MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE;
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goto cleanup;
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}
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/*
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* Jump handshake header (4 bytes, see Section 4 of RFC 8446).
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* ...
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* HandshakeType msg_type;
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* uint24 length;
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* ...
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*/
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*buf = ssl->in_msg + 4;
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*buflen = ssl->in_hslen - 4;
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cleanup:
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return( ret );
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}
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int mbedtls_ssl_tls13_start_handshake_msg( mbedtls_ssl_context *ssl,
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unsigned hs_type,
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unsigned char **buf,
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size_t *buf_len )
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{
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/*
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* Reserve 4 bytes for hanshake header. ( Section 4,RFC 8446 )
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* ...
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* HandshakeType msg_type;
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* uint24 length;
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* ...
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*/
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*buf = ssl->out_msg + 4;
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*buf_len = MBEDTLS_SSL_OUT_CONTENT_LEN - 4;
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ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
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ssl->out_msg[0] = hs_type;
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return( 0 );
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}
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int mbedtls_ssl_tls13_finish_handshake_msg( mbedtls_ssl_context *ssl,
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size_t buf_len,
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size_t msg_len )
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{
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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size_t msg_len_with_header;
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((void) buf_len);
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/* Add reserved 4 bytes for handshake header */
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msg_len_with_header = msg_len + 4;
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ssl->out_msglen = msg_len_with_header;
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MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_write_handshake_msg_ext( ssl, 0 ) );
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cleanup:
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return( ret );
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}
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void mbedtls_ssl_tls1_3_add_hs_msg_to_checksum( mbedtls_ssl_context *ssl,
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unsigned hs_type,
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unsigned char const *msg,
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size_t msg_len )
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{
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mbedtls_ssl_tls13_add_hs_hdr_to_checksum( ssl, hs_type, msg_len );
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ssl->handshake->update_checksum( ssl, msg, msg_len );
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}
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void mbedtls_ssl_tls13_add_hs_hdr_to_checksum( mbedtls_ssl_context *ssl,
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unsigned hs_type,
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size_t total_hs_len )
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{
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unsigned char hs_hdr[4];
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/* Build HS header for checksum update. */
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hs_hdr[0] = MBEDTLS_BYTE_0( hs_type );
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hs_hdr[1] = MBEDTLS_BYTE_2( total_hs_len );
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hs_hdr[2] = MBEDTLS_BYTE_1( total_hs_len );
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hs_hdr[3] = MBEDTLS_BYTE_0( total_hs_len );
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ssl->handshake->update_checksum( ssl, hs_hdr, sizeof( hs_hdr ) );
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}
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#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
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/*
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* mbedtls_ssl_tls13_write_sig_alg_ext( )
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*
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* enum {
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* ....
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* ecdsa_secp256r1_sha256( 0x0403 ),
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* ecdsa_secp384r1_sha384( 0x0503 ),
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* ecdsa_secp521r1_sha512( 0x0603 ),
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* ....
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* } SignatureScheme;
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*
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* struct {
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* SignatureScheme supported_signature_algorithms<2..2^16-2>;
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* } SignatureSchemeList;
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*
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* Only if we handle at least one key exchange that needs signatures.
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*/
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int mbedtls_ssl_tls13_write_sig_alg_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 )
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{
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unsigned char *p = buf;
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unsigned char *supported_sig_alg_ptr; /* Start of supported_signature_algorithms */
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size_t supported_sig_alg_len = 0; /* Length of supported_signature_algorithms */
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*olen = 0;
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/* Skip the extension on the client if all allowed key exchanges
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* are PSK-based. */
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#if defined(MBEDTLS_SSL_CLI_C)
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if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT &&
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!mbedtls_ssl_conf_tls13_some_ephemeral_enabled( ssl ) )
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{
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return( 0 );
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}
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#endif /* MBEDTLS_SSL_CLI_C */
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MBEDTLS_SSL_DEBUG_MSG( 3, ( "adding signature_algorithms extension" ) );
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/* Check if we have space for header and length field:
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* - extension_type (2 bytes)
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* - extension_data_length (2 bytes)
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* - supported_signature_algorithms_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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/*
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* Write supported_signature_algorithms
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*/
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supported_sig_alg_ptr = p;
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for( const uint16_t *sig_alg = ssl->conf->tls13_sig_algs;
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*sig_alg != MBEDTLS_TLS13_SIG_NONE; sig_alg++ )
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{
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MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
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MBEDTLS_PUT_UINT16_BE( *sig_alg, p, 0 );
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p += 2;
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MBEDTLS_SSL_DEBUG_MSG( 3, ( "signature scheme [%x]", *sig_alg ) );
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}
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/* Length of supported_signature_algorithms */
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supported_sig_alg_len = p - supported_sig_alg_ptr;
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if( supported_sig_alg_len == 0 )
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{
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "No signature algorithms 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_SIG_ALG, buf, 0 );
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/* Write extension_data_length */
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MBEDTLS_PUT_UINT16_BE( supported_sig_alg_len + 2, buf, 2 );
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/* Write length of supported_signature_algorithms */
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MBEDTLS_PUT_UINT16_BE( supported_sig_alg_len, buf, 4 );
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/* Output the total length of signature algorithms extension. */
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*olen = p - buf;
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ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_SIG_ALG;
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return( 0 );
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}
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/*
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* STATE HANDLING: Read CertificateVerify
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*/
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/* Macro to express the maximum length of the verify structure.
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*
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* The structure is computed per TLS 1.3 specification as:
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* - 64 bytes of octet 32,
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* - 33 bytes for the context string
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* (which is either "TLS 1.3, client CertificateVerify"
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* or "TLS 1.3, server CertificateVerify"),
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* - 1 byte for the octet 0x0, which serves as a separator,
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* - 32 or 48 bytes for the Transcript-Hash(Handshake Context, Certificate)
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* (depending on the size of the transcript_hash)
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*
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* This results in a total size of
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* - 130 bytes for a SHA256-based transcript hash, or
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* (64 + 33 + 1 + 32 bytes)
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* - 146 bytes for a SHA384-based transcript hash.
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* (64 + 33 + 1 + 48 bytes)
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*
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*/
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#define SSL_VERIFY_STRUCT_MAX_SIZE ( 64 + \
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33 + \
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1 + \
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MBEDTLS_TLS1_3_MD_MAX_SIZE \
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)
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/*
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* The ssl_tls13_create_verify_structure() creates the verify structure.
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* As input, it requires the transcript hash.
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*
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* The caller has to ensure that the buffer has size at least
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* SSL_VERIFY_STRUCT_MAX_SIZE bytes.
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*/
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static void ssl_tls13_create_verify_structure( const unsigned char *transcript_hash,
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size_t transcript_hash_len,
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unsigned char *verify_buffer,
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size_t *verify_buffer_len,
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int from )
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{
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size_t idx;
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/* RFC 8446, Section 4.4.3:
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*
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* The digital signature [in the CertificateVerify message] is then
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* computed over the concatenation of:
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* - A string that consists of octet 32 (0x20) repeated 64 times
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* - The context string
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* - A single 0 byte which serves as the separator
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* - The content to be signed
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*/
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memset( verify_buffer, 0x20, 64 );
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idx = 64;
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if( from == MBEDTLS_SSL_IS_CLIENT )
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{
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memcpy( verify_buffer + idx, MBEDTLS_SSL_TLS1_3_LBL_WITH_LEN( client_cv ) );
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idx += MBEDTLS_SSL_TLS1_3_LBL_LEN( client_cv );
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}
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else
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{ /* from == MBEDTLS_SSL_IS_SERVER */
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memcpy( verify_buffer + idx, MBEDTLS_SSL_TLS1_3_LBL_WITH_LEN( server_cv ) );
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idx += MBEDTLS_SSL_TLS1_3_LBL_LEN( server_cv );
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}
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verify_buffer[idx++] = 0x0;
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memcpy( verify_buffer + idx, transcript_hash, transcript_hash_len );
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idx += transcript_hash_len;
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*verify_buffer_len = idx;
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}
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static int ssl_tls13_sig_alg_is_offered( const mbedtls_ssl_context *ssl,
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uint16_t sig_alg )
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{
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const uint16_t *tls13_sig_alg = ssl->conf->tls13_sig_algs;
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for( ; *tls13_sig_alg != MBEDTLS_TLS13_SIG_NONE ; tls13_sig_alg++ )
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{
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if( *tls13_sig_alg == sig_alg )
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return( 1 );
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}
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return( 0 );
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}
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static int ssl_tls13_parse_certificate_verify( mbedtls_ssl_context *ssl,
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const unsigned char *buf,
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const unsigned char *end,
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const unsigned char *verify_buffer,
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size_t verify_buffer_len )
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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 algorithm;
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size_t signature_len;
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mbedtls_pk_type_t sig_alg;
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mbedtls_md_type_t md_alg;
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unsigned char verify_hash[MBEDTLS_MD_MAX_SIZE];
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size_t verify_hash_len;
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/*
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* struct {
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* SignatureScheme algorithm;
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* opaque signature<0..2^16-1>;
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* } CertificateVerify;
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*/
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MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
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algorithm = MBEDTLS_GET_UINT16_BE( p, 0 );
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p += 2;
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/* RFC 8446 section 4.4.3
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*
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* If the CertificateVerify message is sent by a server, the signature algorithm
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* MUST be one offered in the client's "signature_algorithms" extension unless
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* no valid certificate chain can be produced without unsupported algorithms
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*
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* RFC 8446 section 4.4.2.2
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*
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* If the client cannot construct an acceptable chain using the provided
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* certificates and decides to abort the handshake, then it MUST abort the handshake
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* with an appropriate certificate-related alert (by default, "unsupported_certificate").
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*
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* Check if algorithm is an offered signature algorithm.
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*/
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if( ! ssl_tls13_sig_alg_is_offered( ssl, algorithm ) )
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{
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/* algorithm not in offered signature algorithms list */
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "Received signature algorithm(%04x) is not "
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"offered.",
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( unsigned int ) algorithm ) );
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goto error;
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}
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/* We currently only support ECDSA-based signatures */
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switch( algorithm )
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{
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case MBEDTLS_TLS13_SIG_ECDSA_SECP256R1_SHA256:
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md_alg = MBEDTLS_MD_SHA256;
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sig_alg = MBEDTLS_PK_ECDSA;
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break;
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case MBEDTLS_TLS13_SIG_ECDSA_SECP384R1_SHA384:
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md_alg = MBEDTLS_MD_SHA384;
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sig_alg = MBEDTLS_PK_ECDSA;
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break;
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case MBEDTLS_TLS13_SIG_ECDSA_SECP521R1_SHA512:
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md_alg = MBEDTLS_MD_SHA512;
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sig_alg = MBEDTLS_PK_ECDSA;
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break;
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default:
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "Certificate Verify: Unknown signature algorithm." ) );
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goto error;
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}
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MBEDTLS_SSL_DEBUG_MSG( 3, ( "Certificate Verify: Signature algorithm ( %04x )",
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( unsigned int ) algorithm ) );
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/*
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* Check the certificate's key type matches the signature alg
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*/
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if( !mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk, sig_alg ) )
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{
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "signature algorithm doesn't match cert key" ) );
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goto error;
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}
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MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
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signature_len = MBEDTLS_GET_UINT16_BE( p, 0 );
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p += 2;
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MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, signature_len );
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/* Hash verify buffer with indicated hash function */
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switch( md_alg )
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{
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#if defined(MBEDTLS_SHA256_C)
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case MBEDTLS_MD_SHA256:
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verify_hash_len = 32;
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ret = mbedtls_sha256( verify_buffer, verify_buffer_len, verify_hash, 0 );
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break;
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#endif /* MBEDTLS_SHA256_C */
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#if defined(MBEDTLS_SHA384_C)
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case MBEDTLS_MD_SHA384:
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verify_hash_len = 48;
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ret = mbedtls_sha512( verify_buffer, verify_buffer_len, verify_hash, 1 );
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break;
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#endif /* MBEDTLS_SHA384_C */
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#if defined(MBEDTLS_SHA512_C)
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case MBEDTLS_MD_SHA512:
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verify_hash_len = 64;
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ret = mbedtls_sha512( verify_buffer, verify_buffer_len, verify_hash, 0 );
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break;
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#endif /* MBEDTLS_SHA512_C */
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default:
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ret = MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE;
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break;
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}
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if( ret != 0 )
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{
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MBEDTLS_SSL_DEBUG_RET( 1, "hash computation error", ret );
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goto error;
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}
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MBEDTLS_SSL_DEBUG_BUF( 3, "verify hash", verify_hash, verify_hash_len );
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if( ( ret = mbedtls_pk_verify_ext( sig_alg, NULL,
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&ssl->session_negotiate->peer_cert->pk,
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md_alg, verify_hash, verify_hash_len,
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p, signature_len ) ) == 0 )
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{
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return( 0 );
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}
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MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_verify_ext", ret );
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error:
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/* RFC 8446 section 4.4.3
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*
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* If the verification fails, the receiver MUST terminate the handshake
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* with a "decrypt_error" alert.
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*/
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MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECRYPT_ERROR,
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MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
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return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
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}
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#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
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int mbedtls_ssl_tls13_process_certificate_verify( mbedtls_ssl_context *ssl )
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{
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#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
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int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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unsigned char verify_buffer[SSL_VERIFY_STRUCT_MAX_SIZE];
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size_t verify_buffer_len;
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unsigned char transcript[MBEDTLS_TLS1_3_MD_MAX_SIZE];
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size_t transcript_len;
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unsigned char *buf;
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size_t buf_len;
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MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) );
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MBEDTLS_SSL_PROC_CHK(
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mbedtls_ssl_tls1_3_fetch_handshake_msg( ssl,
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MBEDTLS_SSL_HS_CERTIFICATE_VERIFY, &buf, &buf_len ) );
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/* Need to calculate the hash of the transcript first
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* before reading the message since otherwise it gets
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* included in the transcript
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*/
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ret = mbedtls_ssl_get_handshake_transcript( ssl,
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ssl->handshake->ciphersuite_info->mac,
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transcript, sizeof( transcript ),
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&transcript_len );
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if( ret != 0 )
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{
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MBEDTLS_SSL_PEND_FATAL_ALERT(
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MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR,
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MBEDTLS_ERR_SSL_INTERNAL_ERROR );
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return( ret );
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}
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MBEDTLS_SSL_DEBUG_BUF( 3, "handshake hash", transcript, transcript_len );
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/* Create verify structure */
|
|
ssl_tls13_create_verify_structure( transcript,
|
|
transcript_len,
|
|
verify_buffer,
|
|
&verify_buffer_len,
|
|
( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) ?
|
|
MBEDTLS_SSL_IS_SERVER :
|
|
MBEDTLS_SSL_IS_CLIENT );
|
|
|
|
/* Process the message contents */
|
|
MBEDTLS_SSL_PROC_CHK( ssl_tls13_parse_certificate_verify( ssl, buf,
|
|
buf + buf_len, verify_buffer, verify_buffer_len ) );
|
|
|
|
mbedtls_ssl_tls1_3_add_hs_msg_to_checksum( ssl,
|
|
MBEDTLS_SSL_HS_CERTIFICATE_VERIFY, buf, buf_len );
|
|
|
|
cleanup:
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate verify" ) );
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_process_certificate_verify", ret );
|
|
return( ret );
|
|
#else
|
|
((void) ssl);
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
|
|
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
|
|
}
|
|
|
|
/*
|
|
*
|
|
* STATE HANDLING: Incoming Certificate, client-side only currently.
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* Implementation
|
|
*/
|
|
|
|
#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
|
|
#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
|
|
/*
|
|
* Structure of Certificate message:
|
|
*
|
|
* enum {
|
|
* X509(0),
|
|
* RawPublicKey(2),
|
|
* (255)
|
|
* } CertificateType;
|
|
*
|
|
* struct {
|
|
* select (certificate_type) {
|
|
* case RawPublicKey:
|
|
* * From RFC 7250 ASN.1_subjectPublicKeyInfo *
|
|
* opaque ASN1_subjectPublicKeyInfo<1..2^24-1>;
|
|
* case X509:
|
|
* opaque cert_data<1..2^24-1>;
|
|
* };
|
|
* Extension extensions<0..2^16-1>;
|
|
* } CertificateEntry;
|
|
*
|
|
* struct {
|
|
* opaque certificate_request_context<0..2^8-1>;
|
|
* CertificateEntry certificate_list<0..2^24-1>;
|
|
* } Certificate;
|
|
*
|
|
*/
|
|
|
|
/* Parse certificate chain send by the server. */
|
|
static int ssl_tls13_parse_certificate( mbedtls_ssl_context *ssl,
|
|
const unsigned char *buf,
|
|
const unsigned char *end )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
size_t certificate_request_context_len = 0;
|
|
size_t certificate_list_len = 0;
|
|
const unsigned char *p = buf;
|
|
const unsigned char *certificate_list_end;
|
|
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 4 );
|
|
certificate_request_context_len = p[0];
|
|
certificate_list_len = MBEDTLS_GET_UINT24_BE( p, 1 );
|
|
p += 4;
|
|
|
|
/* In theory, the certificate list can be up to 2^24 Bytes, but we don't
|
|
* support anything beyond 2^16 = 64K.
|
|
*/
|
|
if( ( certificate_request_context_len != 0 ) ||
|
|
( certificate_list_len >= 0x10000 ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate message" ) );
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
|
|
MBEDTLS_ERR_SSL_DECODE_ERROR );
|
|
return( MBEDTLS_ERR_SSL_DECODE_ERROR );
|
|
}
|
|
|
|
/* In case we tried to reuse a session but it failed */
|
|
if( ssl->session_negotiate->peer_cert != NULL )
|
|
{
|
|
mbedtls_x509_crt_free( ssl->session_negotiate->peer_cert );
|
|
mbedtls_free( ssl->session_negotiate->peer_cert );
|
|
}
|
|
|
|
if( ( ssl->session_negotiate->peer_cert =
|
|
mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) ) ) == NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "alloc( %" MBEDTLS_PRINTF_SIZET " bytes ) failed",
|
|
sizeof( mbedtls_x509_crt ) ) );
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR,
|
|
MBEDTLS_ERR_SSL_ALLOC_FAILED );
|
|
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
|
|
}
|
|
|
|
mbedtls_x509_crt_init( ssl->session_negotiate->peer_cert );
|
|
|
|
certificate_list_end = p + certificate_list_len;
|
|
while( p < certificate_list_end )
|
|
{
|
|
size_t cert_data_len, extensions_len;
|
|
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, certificate_list_end, 3 );
|
|
cert_data_len = MBEDTLS_GET_UINT24_BE( p, 0 );
|
|
p += 3;
|
|
|
|
/* In theory, the CRT can be up to 2^24 Bytes, but we don't support
|
|
* anything beyond 2^16 = 64K. Otherwise as in the TLS 1.2 code,
|
|
* check that we have a minimum of 128 bytes of data, this is not
|
|
* clear why we need that though.
|
|
*/
|
|
if( ( cert_data_len < 128 ) || ( cert_data_len >= 0x10000 ) )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad Certificate message" ) );
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
|
|
MBEDTLS_ERR_SSL_DECODE_ERROR );
|
|
return( MBEDTLS_ERR_SSL_DECODE_ERROR );
|
|
}
|
|
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, certificate_list_end, cert_data_len );
|
|
ret = mbedtls_x509_crt_parse_der( ssl->session_negotiate->peer_cert,
|
|
p, cert_data_len );
|
|
|
|
switch( ret )
|
|
{
|
|
case 0: /*ok*/
|
|
break;
|
|
case MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG + MBEDTLS_ERR_OID_NOT_FOUND:
|
|
/* Ignore certificate with an unknown algorithm: maybe a
|
|
prior certificate was already trusted. */
|
|
break;
|
|
|
|
case MBEDTLS_ERR_X509_ALLOC_FAILED:
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR,
|
|
MBEDTLS_ERR_X509_ALLOC_FAILED );
|
|
MBEDTLS_SSL_DEBUG_RET( 1, " mbedtls_x509_crt_parse_der", ret );
|
|
return( ret );
|
|
|
|
case MBEDTLS_ERR_X509_UNKNOWN_VERSION:
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT,
|
|
MBEDTLS_ERR_X509_UNKNOWN_VERSION );
|
|
MBEDTLS_SSL_DEBUG_RET( 1, " mbedtls_x509_crt_parse_der", ret );
|
|
return( ret );
|
|
|
|
default:
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_BAD_CERT,
|
|
ret );
|
|
MBEDTLS_SSL_DEBUG_RET( 1, " mbedtls_x509_crt_parse_der", ret );
|
|
return( ret );
|
|
}
|
|
|
|
p += cert_data_len;
|
|
|
|
/* Certificate extensions length */
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, certificate_list_end, 2 );
|
|
extensions_len = MBEDTLS_GET_UINT16_BE( p, 0 );
|
|
p += 2;
|
|
MBEDTLS_SSL_CHK_BUF_READ_PTR( p, certificate_list_end, extensions_len );
|
|
p += extensions_len;
|
|
}
|
|
|
|
/* Check that all the message is consumed. */
|
|
if( p != end )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad Certificate message" ) );
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, \
|
|
MBEDTLS_ERR_SSL_DECODE_ERROR );
|
|
return( MBEDTLS_ERR_SSL_DECODE_ERROR );
|
|
}
|
|
|
|
MBEDTLS_SSL_DEBUG_CRT( 3, "peer certificate", ssl->session_negotiate->peer_cert );
|
|
|
|
return( ret );
|
|
}
|
|
#else
|
|
static int ssl_tls13_parse_certificate( mbedtls_ssl_context *ssl,
|
|
const unsigned char *buf,
|
|
const unsigned char *end )
|
|
{
|
|
((void) ssl);
|
|
((void) buf);
|
|
((void) end);
|
|
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
|
|
}
|
|
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
|
|
#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
|
|
|
|
#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
|
|
#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
|
|
/* Validate certificate chain sent by the server. */
|
|
static int ssl_tls13_validate_certificate( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = 0;
|
|
mbedtls_x509_crt *ca_chain;
|
|
mbedtls_x509_crl *ca_crl;
|
|
uint32_t verify_result = 0;
|
|
|
|
#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
|
|
if( ssl->handshake->sni_ca_chain != NULL )
|
|
{
|
|
ca_chain = ssl->handshake->sni_ca_chain;
|
|
ca_crl = ssl->handshake->sni_ca_crl;
|
|
}
|
|
else
|
|
#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
|
|
{
|
|
ca_chain = ssl->conf->ca_chain;
|
|
ca_crl = ssl->conf->ca_crl;
|
|
}
|
|
|
|
/*
|
|
* Main check: verify certificate
|
|
*/
|
|
ret = mbedtls_x509_crt_verify_with_profile(
|
|
ssl->session_negotiate->peer_cert,
|
|
ca_chain, ca_crl,
|
|
ssl->conf->cert_profile,
|
|
ssl->hostname,
|
|
&verify_result,
|
|
ssl->conf->f_vrfy, ssl->conf->p_vrfy );
|
|
|
|
if( ret != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_RET( 1, "x509_verify_cert", ret );
|
|
}
|
|
|
|
/*
|
|
* Secondary checks: always done, but change 'ret' only if it was 0
|
|
*/
|
|
|
|
#if defined(MBEDTLS_ECP_C)
|
|
{
|
|
const mbedtls_pk_context *pk = &ssl->session_negotiate->peer_cert->pk;
|
|
|
|
/* If certificate uses an EC key, make sure the curve is OK */
|
|
if( mbedtls_pk_can_do( pk, MBEDTLS_PK_ECKEY ) &&
|
|
mbedtls_ssl_check_curve( ssl, mbedtls_pk_ec( *pk )->grp.id ) != 0 )
|
|
{
|
|
verify_result |= MBEDTLS_X509_BADCERT_BAD_KEY;
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate ( EC key curve )" ) );
|
|
if( ret == 0 )
|
|
ret = MBEDTLS_ERR_SSL_BAD_CERTIFICATE;
|
|
}
|
|
}
|
|
#endif /* MBEDTLS_ECP_C */
|
|
|
|
if( mbedtls_ssl_check_cert_usage( ssl->session_negotiate->peer_cert,
|
|
ssl->handshake->ciphersuite_info,
|
|
!ssl->conf->endpoint,
|
|
&verify_result ) != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate ( usage extensions )" ) );
|
|
if( ret == 0 )
|
|
ret = MBEDTLS_ERR_SSL_BAD_CERTIFICATE;
|
|
}
|
|
|
|
|
|
if( ca_chain == NULL )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no CA chain" ) );
|
|
ret = MBEDTLS_ERR_SSL_CA_CHAIN_REQUIRED;
|
|
}
|
|
|
|
if( ret != 0 )
|
|
{
|
|
/* The certificate may have been rejected for several reasons.
|
|
Pick one and send the corresponding alert. Which alert to send
|
|
may be a subject of debate in some cases. */
|
|
if( verify_result & MBEDTLS_X509_BADCERT_OTHER )
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED, ret );
|
|
else if( verify_result & MBEDTLS_X509_BADCERT_CN_MISMATCH )
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_BAD_CERT, ret );
|
|
else if( verify_result & ( MBEDTLS_X509_BADCERT_KEY_USAGE |
|
|
MBEDTLS_X509_BADCERT_EXT_KEY_USAGE |
|
|
MBEDTLS_X509_BADCERT_NS_CERT_TYPE |
|
|
MBEDTLS_X509_BADCERT_BAD_PK |
|
|
MBEDTLS_X509_BADCERT_BAD_KEY ) )
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT, ret );
|
|
else if( verify_result & MBEDTLS_X509_BADCERT_EXPIRED )
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_CERT_EXPIRED, ret );
|
|
else if( verify_result & MBEDTLS_X509_BADCERT_REVOKED )
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_CERT_REVOKED, ret );
|
|
else if( verify_result & MBEDTLS_X509_BADCERT_NOT_TRUSTED )
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_UNKNOWN_CA, ret );
|
|
else
|
|
MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_CERT_UNKNOWN, ret );
|
|
}
|
|
|
|
#if defined(MBEDTLS_DEBUG_C)
|
|
if( verify_result != 0 )
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "! Certificate verification flags %08x",
|
|
(unsigned int) verify_result ) );
|
|
}
|
|
else
|
|
{
|
|
MBEDTLS_SSL_DEBUG_MSG( 3, ( "Certificate verification flags clear" ) );
|
|
}
|
|
#endif /* MBEDTLS_DEBUG_C */
|
|
|
|
ssl->session_negotiate->verify_result = verify_result;
|
|
return( ret );
|
|
}
|
|
#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
|
|
static int ssl_tls13_validate_certificate( mbedtls_ssl_context *ssl )
|
|
{
|
|
((void) ssl);
|
|
return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
|
|
}
|
|
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
|
|
#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
|
|
|
|
int mbedtls_ssl_tls13_process_certificate( mbedtls_ssl_context *ssl )
|
|
{
|
|
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) );
|
|
|
|
#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
|
|
unsigned char *buf;
|
|
size_t buf_len;
|
|
|
|
MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls1_3_fetch_handshake_msg(
|
|
ssl, MBEDTLS_SSL_HS_CERTIFICATE,
|
|
&buf, &buf_len ) );
|
|
|
|
/* Parse the certificate chain sent by the peer. */
|
|
MBEDTLS_SSL_PROC_CHK( ssl_tls13_parse_certificate( ssl, buf, buf + buf_len ) );
|
|
/* Validate the certificate chain and set the verification results. */
|
|
MBEDTLS_SSL_PROC_CHK( ssl_tls13_validate_certificate( ssl ) );
|
|
|
|
mbedtls_ssl_tls1_3_add_hs_msg_to_checksum( ssl, MBEDTLS_SSL_HS_CERTIFICATE,
|
|
buf, buf_len );
|
|
|
|
cleanup:
|
|
|
|
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate" ) );
|
|
#else
|
|
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
|
|
ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR;
|
|
#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
|
|
return( ret );
|
|
}
|
|
|
|
#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
|
|
|
|
#endif /* MBEDTLS_SSL_TLS_C */
|