ssl_srv.c

00001 /*
00002  *  SSLv3/TLSv1 server-side functions
00003  *
00004  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
00005  *  SPDX-License-Identifier: Apache-2.0
00006  *
00007  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00008  *  not use this file except in compliance with the License.
00009  *  You may obtain a copy of the License at
00010  *
00011  *  http://www.apache.org/licenses/LICENSE-2.0
00012  *
00013  *  Unless required by applicable law or agreed to in writing, software
00014  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00015  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00016  *  See the License for the specific language governing permissions and
00017  *  limitations under the License.
00018  *
00019  *  This file is part of mbed TLS (https://tls.mbed.org)
00020  */
00021 
00022 #if !defined(MBEDTLS_CONFIG_FILE)
00023 #include "mbedtls/config.h"
00024 #else
00025 #include MBEDTLS_CONFIG_FILE
00026 #endif
00027 
00028 #if defined(MBEDTLS_SSL_SRV_C)
00029 
00030 #if defined(MBEDTLS_PLATFORM_C)
00031 #include "mbedtls/platform.h"
00032 #else
00033 #include <stdlib.h>
00034 #define mbedtls_calloc    calloc
00035 #define mbedtls_free      free
00036 #endif
00037 
00038 #include "mbedtls/debug.h"
00039 #include "mbedtls/ssl.h"
00040 #include "mbedtls/ssl_internal.h"
00041 
00042 #include <string.h>
00043 
00044 #if defined(MBEDTLS_ECP_C)
00045 #include "mbedtls/ecp.h"
00046 #endif
00047 
00048 #if defined(MBEDTLS_HAVE_TIME)
00049 #include "mbedtls/platform_time.h"
00050 #endif
00051 
00052 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
00053 /* Implementation that should never be optimized out by the compiler */
00054 static void mbedtls_zeroize( void *v, size_t n ) {
00055     volatile unsigned char *p = v; while( n-- ) *p++ = 0;
00056 }
00057 #endif
00058 
00059 #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
00060 int mbedtls_ssl_set_client_transport_id( mbedtls_ssl_context *ssl,
00061                                  const unsigned char *info,
00062                                  size_t ilen )
00063 {
00064     if( ssl->conf->endpoint != MBEDTLS_SSL_IS_SERVER )
00065         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
00066 
00067     mbedtls_free( ssl->cli_id );
00068 
00069     if( ( ssl->cli_id = mbedtls_calloc( 1, ilen ) ) == NULL )
00070         return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
00071 
00072     memcpy( ssl->cli_id, info, ilen );
00073     ssl->cli_id_len = ilen;
00074 
00075     return( 0 );
00076 }
00077 
00078 void mbedtls_ssl_conf_dtls_cookies( mbedtls_ssl_config *conf,
00079                            mbedtls_ssl_cookie_write_t *f_cookie_write,
00080                            mbedtls_ssl_cookie_check_t *f_cookie_check,
00081                            void *p_cookie )
00082 {
00083     conf->f_cookie_write = f_cookie_write;
00084     conf->f_cookie_check = f_cookie_check;
00085     conf->p_cookie        = p_cookie;
00086 }
00087 #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */
00088 
00089 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
00090 static int ssl_parse_servername_ext( mbedtls_ssl_context *ssl,
00091                                      const unsigned char *buf,
00092                                      size_t len )
00093 {
00094     int ret;
00095     size_t servername_list_size, hostname_len;
00096     const unsigned char *p;
00097 
00098     MBEDTLS_SSL_DEBUG_MSG( 3, ( "parse ServerName extension" ) );
00099 
00100     servername_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
00101     if( servername_list_size + 2 != len )
00102     {
00103         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
00104         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00105                                         MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
00106         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00107     }
00108 
00109     p = buf + 2;
00110     while( servername_list_size > 0 )
00111     {
00112         hostname_len = ( ( p[1] << 8 ) | p[2] );
00113         if( hostname_len + 3 > servername_list_size )
00114         {
00115             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
00116             mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00117                                             MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
00118             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00119         }
00120 
00121         if( p[0] == MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME )
00122         {
00123             ret = ssl->conf->f_sni( ssl->conf->p_sni,
00124                                     ssl, p + 3, hostname_len );
00125             if( ret != 0 )
00126             {
00127                 MBEDTLS_SSL_DEBUG_RET( 1, "ssl_sni_wrapper", ret );
00128                 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00129                         MBEDTLS_SSL_ALERT_MSG_UNRECOGNIZED_NAME );
00130                 return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00131             }
00132             return( 0 );
00133         }
00134 
00135         servername_list_size -= hostname_len + 3;
00136         p += hostname_len + 3;
00137     }
00138 
00139     if( servername_list_size != 0 )
00140     {
00141         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
00142         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00143                                         MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
00144         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00145     }
00146 
00147     return( 0 );
00148 }
00149 #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
00150 
00151 static int ssl_parse_renegotiation_info( mbedtls_ssl_context *ssl,
00152                                          const unsigned char *buf,
00153                                          size_t len )
00154 {
00155 #if defined(MBEDTLS_SSL_RENEGOTIATION)
00156     if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
00157     {
00158         /* Check verify-data in constant-time. The length OTOH is no secret */
00159         if( len    != 1 + ssl->verify_data_len ||
00160             buf[0] !=     ssl->verify_data_len ||
00161             mbedtls_ssl_safer_memcmp( buf + 1, ssl->peer_verify_data,
00162                           ssl->verify_data_len ) != 0 )
00163         {
00164             MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-matching renegotiation info" ) );
00165             mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00166                                             MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
00167             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00168         }
00169     }
00170     else
00171 #endif /* MBEDTLS_SSL_RENEGOTIATION */
00172     {
00173         if( len != 1 || buf[0] != 0x0 )
00174         {
00175             MBEDTLS_SSL_DEBUG_MSG( 1, ( "non-zero length renegotiation info" ) );
00176             mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00177                                             MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
00178             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00179         }
00180 
00181         ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
00182     }
00183 
00184     return( 0 );
00185 }
00186 
00187 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
00188     defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
00189 
00190 /*
00191  * Status of the implementation of signature-algorithms extension:
00192  *
00193  * Currently, we are only considering the signature-algorithm extension
00194  * to pick a ciphersuite which allows us to send the ServerKeyExchange
00195  * message with a signature-hash combination that the user allows.
00196  *
00197  * We do *not* check whether all certificates in our certificate
00198  * chain are signed with an allowed signature-hash pair.
00199  * This needs to be done at a later stage.
00200  *
00201  */
00202 static int ssl_parse_signature_algorithms_ext( mbedtls_ssl_context *ssl,
00203                                                const unsigned char *buf,
00204                                                size_t len )
00205 {
00206     size_t sig_alg_list_size;
00207 
00208     const unsigned char *p;
00209     const unsigned char *end = buf + len;
00210 
00211     mbedtls_md_type_t md_cur;
00212     mbedtls_pk_type_t sig_cur;
00213 
00214     sig_alg_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
00215     if( sig_alg_list_size + 2 != len ||
00216         sig_alg_list_size % 2 != 0 )
00217     {
00218         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
00219         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00220                                         MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
00221         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00222     }
00223 
00224     /* Currently we only guarantee signing the ServerKeyExchange message according
00225      * to the constraints specified in this extension (see above), so it suffices
00226      * to remember only one suitable hash for each possible signature algorithm.
00227      *
00228      * This will change when we also consider certificate signatures,
00229      * in which case we will need to remember the whole signature-hash
00230      * pair list from the extension.
00231      */
00232 
00233     for( p = buf + 2; p < end; p += 2 )
00234     {
00235         /* Silently ignore unknown signature or hash algorithms. */
00236 
00237         if( ( sig_cur = mbedtls_ssl_pk_alg_from_sig( p[1] ) ) == MBEDTLS_PK_NONE )
00238         {
00239             MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext"
00240                                         " unknown sig alg encoding %d", p[1] ) );
00241             continue;
00242         }
00243 
00244         /* Check if we support the hash the user proposes */
00245         md_cur = mbedtls_ssl_md_alg_from_hash( p[0] );
00246         if( md_cur == MBEDTLS_MD_NONE )
00247         {
00248             MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext:"
00249                                         " unknown hash alg encoding %d", p[0] ) );
00250             continue;
00251         }
00252 
00253         if( mbedtls_ssl_check_sig_hash( ssl, md_cur ) == 0 )
00254         {
00255             mbedtls_ssl_sig_hash_set_add( &ssl->handshake->hash_algs, sig_cur, md_cur );
00256             MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext:"
00257                                         " match sig %d and hash %d",
00258                                         sig_cur, md_cur ) );
00259         }
00260         else
00261         {
00262             MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext: "
00263                                         "hash alg %d not supported", md_cur ) );
00264         }
00265     }
00266 
00267     return( 0 );
00268 }
00269 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
00270           MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
00271 
00272 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
00273     defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
00274 static int ssl_parse_supported_elliptic_curves( mbedtls_ssl_context *ssl,
00275                                                 const unsigned char *buf,
00276                                                 size_t len )
00277 {
00278     size_t list_size, our_size;
00279     const unsigned char *p;
00280     const mbedtls_ecp_curve_info *curve_info, **curves;
00281 
00282     list_size = ( ( buf[0] << 8 ) | ( buf[1] ) );
00283     if( list_size + 2 != len ||
00284         list_size % 2 != 0 )
00285     {
00286         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
00287         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00288                                         MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
00289         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00290     }
00291 
00292     /* Should never happen unless client duplicates the extension */
00293     if( ssl->handshake->curves != NULL )
00294     {
00295         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
00296         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00297                                         MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
00298         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00299     }
00300 
00301     /* Don't allow our peer to make us allocate too much memory,
00302      * and leave room for a final 0 */
00303     our_size = list_size / 2 + 1;
00304     if( our_size > MBEDTLS_ECP_DP_MAX )
00305         our_size = MBEDTLS_ECP_DP_MAX;
00306 
00307     if( ( curves = mbedtls_calloc( our_size, sizeof( *curves ) ) ) == NULL )
00308     {
00309         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00310                                         MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR );
00311         return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
00312     }
00313 
00314     ssl->handshake->curves = curves;
00315 
00316     p = buf + 2;
00317     while( list_size > 0 && our_size > 1 )
00318     {
00319         curve_info = mbedtls_ecp_curve_info_from_tls_id( ( p[0] << 8 ) | p[1] );
00320 
00321         if( curve_info != NULL )
00322         {
00323             *curves++ = curve_info;
00324             our_size--;
00325         }
00326 
00327         list_size -= 2;
00328         p += 2;
00329     }
00330 
00331     return( 0 );
00332 }
00333 
00334 static int ssl_parse_supported_point_formats( mbedtls_ssl_context *ssl,
00335                                               const unsigned char *buf,
00336                                               size_t len )
00337 {
00338     size_t list_size;
00339     const unsigned char *p;
00340 
00341     list_size = buf[0];
00342     if( list_size + 1 != len )
00343     {
00344         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
00345         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00346                                         MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
00347         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00348     }
00349 
00350     p = buf + 1;
00351     while( list_size > 0 )
00352     {
00353         if( p[0] == MBEDTLS_ECP_PF_UNCOMPRESSED ||
00354             p[0] == MBEDTLS_ECP_PF_COMPRESSED )
00355         {
00356 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C)
00357             ssl->handshake->ecdh_ctx.point_format = p[0];
00358 #endif
00359 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
00360             ssl->handshake->ecjpake_ctx.point_format = p[0];
00361 #endif
00362             MBEDTLS_SSL_DEBUG_MSG( 4, ( "point format selected: %d", p[0] ) );
00363             return( 0 );
00364         }
00365 
00366         list_size--;
00367         p++;
00368     }
00369 
00370     return( 0 );
00371 }
00372 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
00373           MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
00374 
00375 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
00376 static int ssl_parse_ecjpake_kkpp( mbedtls_ssl_context *ssl,
00377                                    const unsigned char *buf,
00378                                    size_t len )
00379 {
00380     int ret;
00381 
00382     if( mbedtls_ecjpake_check( &ssl->handshake->ecjpake_ctx ) != 0 )
00383     {
00384         MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip ecjpake kkpp extension" ) );
00385         return( 0 );
00386     }
00387 
00388     if( ( ret = mbedtls_ecjpake_read_round_one( &ssl->handshake->ecjpake_ctx,
00389                                                 buf, len ) ) != 0 )
00390     {
00391         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_one", ret );
00392         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00393                                         MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
00394         return( ret );
00395     }
00396 
00397     /* Only mark the extension as OK when we're sure it is */
00398     ssl->handshake->cli_exts |= MBEDTLS_TLS_EXT_ECJPAKE_KKPP_OK;
00399 
00400     return( 0 );
00401 }
00402 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
00403 
00404 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
00405 static int ssl_parse_max_fragment_length_ext( mbedtls_ssl_context *ssl,
00406                                               const unsigned char *buf,
00407                                               size_t len )
00408 {
00409     if( len != 1 || buf[0] >= MBEDTLS_SSL_MAX_FRAG_LEN_INVALID )
00410     {
00411         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
00412         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00413                                         MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
00414         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00415     }
00416 
00417     ssl->session_negotiate->mfl_code = buf[0];
00418 
00419     return( 0 );
00420 }
00421 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
00422 
00423 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
00424 static int ssl_parse_truncated_hmac_ext( mbedtls_ssl_context *ssl,
00425                                          const unsigned char *buf,
00426                                          size_t len )
00427 {
00428     if( len != 0 )
00429     {
00430         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
00431         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00432                                         MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
00433         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00434     }
00435 
00436     ((void) buf);
00437 
00438     if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_ENABLED )
00439         ssl->session_negotiate->trunc_hmac = MBEDTLS_SSL_TRUNC_HMAC_ENABLED;
00440 
00441     return( 0 );
00442 }
00443 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
00444 
00445 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
00446 static int ssl_parse_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
00447                                       const unsigned char *buf,
00448                                       size_t len )
00449 {
00450     if( len != 0 )
00451     {
00452         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
00453         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00454                                         MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
00455         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00456     }
00457 
00458     ((void) buf);
00459 
00460     if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_ENABLED &&
00461         ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_0 )
00462     {
00463         ssl->session_negotiate->encrypt_then_mac = MBEDTLS_SSL_ETM_ENABLED;
00464     }
00465 
00466     return( 0 );
00467 }
00468 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
00469 
00470 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
00471 static int ssl_parse_extended_ms_ext( mbedtls_ssl_context *ssl,
00472                                       const unsigned char *buf,
00473                                       size_t len )
00474 {
00475     if( len != 0 )
00476     {
00477         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
00478         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00479                                         MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
00480         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00481     }
00482 
00483     ((void) buf);
00484 
00485     if( ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_ENABLED &&
00486         ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_0 )
00487     {
00488         ssl->handshake->extended_ms = MBEDTLS_SSL_EXTENDED_MS_ENABLED;
00489     }
00490 
00491     return( 0 );
00492 }
00493 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
00494 
00495 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
00496 static int ssl_parse_session_ticket_ext( mbedtls_ssl_context *ssl,
00497                                          unsigned char *buf,
00498                                          size_t len )
00499 {
00500     int ret;
00501     mbedtls_ssl_session session;
00502 
00503     mbedtls_ssl_session_init( &session );
00504 
00505     if( ssl->conf->f_ticket_parse == NULL ||
00506         ssl->conf->f_ticket_write == NULL )
00507     {
00508         return( 0 );
00509     }
00510 
00511     /* Remember the client asked us to send a new ticket */
00512     ssl->handshake->new_session_ticket = 1;
00513 
00514     MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket length: %d", len ) );
00515 
00516     if( len == 0 )
00517         return( 0 );
00518 
00519 #if defined(MBEDTLS_SSL_RENEGOTIATION)
00520     if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
00521     {
00522         MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket rejected: renegotiating" ) );
00523         return( 0 );
00524     }
00525 #endif /* MBEDTLS_SSL_RENEGOTIATION */
00526 
00527     /*
00528      * Failures are ok: just ignore the ticket and proceed.
00529      */
00530     if( ( ret = ssl->conf->f_ticket_parse( ssl->conf->p_ticket, &session,
00531                                            buf, len ) ) != 0 )
00532     {
00533         mbedtls_ssl_session_free( &session );
00534 
00535         if( ret == MBEDTLS_ERR_SSL_INVALID_MAC )
00536             MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket is not authentic" ) );
00537         else if( ret == MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED )
00538             MBEDTLS_SSL_DEBUG_MSG( 3, ( "ticket is expired" ) );
00539         else
00540             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_ticket_parse", ret );
00541 
00542         return( 0 );
00543     }
00544 
00545     /*
00546      * Keep the session ID sent by the client, since we MUST send it back to
00547      * inform them we're accepting the ticket  (RFC 5077 section 3.4)
00548      */
00549     session.id_len = ssl->session_negotiate->id_len;
00550     memcpy( &session.id, ssl->session_negotiate->id, session.id_len );
00551 
00552     mbedtls_ssl_session_free( ssl->session_negotiate );
00553     memcpy( ssl->session_negotiate, &session, sizeof( mbedtls_ssl_session ) );
00554 
00555     /* Zeroize instead of free as we copied the content */
00556     mbedtls_zeroize( &session, sizeof( mbedtls_ssl_session ) );
00557 
00558     MBEDTLS_SSL_DEBUG_MSG( 3, ( "session successfully restored from ticket" ) );
00559 
00560     ssl->handshake->resume = 1;
00561 
00562     /* Don't send a new ticket after all, this one is OK */
00563     ssl->handshake->new_session_ticket = 0;
00564 
00565     return( 0 );
00566 }
00567 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
00568 
00569 #if defined(MBEDTLS_SSL_ALPN)
00570 static int ssl_parse_alpn_ext( mbedtls_ssl_context *ssl,
00571                                const unsigned char *buf, size_t len )
00572 {
00573     size_t list_len, cur_len, ours_len;
00574     const unsigned char *theirs, *start, *end;
00575     const char **ours;
00576 
00577     /* If ALPN not configured, just ignore the extension */
00578     if( ssl->conf->alpn_list == NULL )
00579         return( 0 );
00580 
00581     /*
00582      * opaque ProtocolName<1..2^8-1>;
00583      *
00584      * struct {
00585      *     ProtocolName protocol_name_list<2..2^16-1>
00586      * } ProtocolNameList;
00587      */
00588 
00589     /* Min length is 2 (list_len) + 1 (name_len) + 1 (name) */
00590     if( len < 4 )
00591     {
00592         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00593                                         MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
00594         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00595     }
00596 
00597     list_len = ( buf[0] << 8 ) | buf[1];
00598     if( list_len != len - 2 )
00599     {
00600         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00601                                         MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
00602         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00603     }
00604 
00605     /*
00606      * Validate peer's list (lengths)
00607      */
00608     start = buf + 2;
00609     end = buf + len;
00610     for( theirs = start; theirs != end; theirs += cur_len )
00611     {
00612         cur_len = *theirs++;
00613 
00614         /* Current identifier must fit in list */
00615         if( cur_len > (size_t)( end - theirs ) )
00616         {
00617             mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00618                                             MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
00619             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00620         }
00621 
00622         /* Empty strings MUST NOT be included */
00623         if( cur_len == 0 )
00624         {
00625             mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00626                                             MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
00627             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00628         }
00629     }
00630 
00631     /*
00632      * Use our order of preference
00633      */
00634     for( ours = ssl->conf->alpn_list; *ours != NULL; ours++ )
00635     {
00636         ours_len = strlen( *ours );
00637         for( theirs = start; theirs != end; theirs += cur_len )
00638         {
00639             cur_len = *theirs++;
00640 
00641             if( cur_len == ours_len &&
00642                 memcmp( theirs, *ours, cur_len ) == 0 )
00643             {
00644                 ssl->alpn_chosen = *ours;
00645                 return( 0 );
00646             }
00647         }
00648     }
00649 
00650     /* If we get there, no match was found */
00651     mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00652                             MBEDTLS_SSL_ALERT_MSG_NO_APPLICATION_PROTOCOL );
00653     return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00654 }
00655 #endif /* MBEDTLS_SSL_ALPN */
00656 
00657 /*
00658  * Auxiliary functions for ServerHello parsing and related actions
00659  */
00660 
00661 #if defined(MBEDTLS_X509_CRT_PARSE_C)
00662 /*
00663  * Return 0 if the given key uses one of the acceptable curves, -1 otherwise
00664  */
00665 #if defined(MBEDTLS_ECDSA_C)
00666 static int ssl_check_key_curve( mbedtls_pk_context *pk,
00667                                 const mbedtls_ecp_curve_info **curves )
00668 {
00669     const mbedtls_ecp_curve_info **crv = curves;
00670     mbedtls_ecp_group_id grp_id = mbedtls_pk_ec( *pk )->grp .id ;
00671 
00672     while( *crv != NULL )
00673     {
00674         if( (*crv)->grp_id == grp_id )
00675             return( 0 );
00676         crv++;
00677     }
00678 
00679     return( -1 );
00680 }
00681 #endif /* MBEDTLS_ECDSA_C */
00682 
00683 /*
00684  * Try picking a certificate for this ciphersuite,
00685  * return 0 on success and -1 on failure.
00686  */
00687 static int ssl_pick_cert( mbedtls_ssl_context *ssl,
00688                           const mbedtls_ssl_ciphersuite_t * ciphersuite_info )
00689 {
00690     mbedtls_ssl_key_cert *cur, *list, *fallback = NULL;
00691     mbedtls_pk_type_t pk_alg =
00692         mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info );
00693     uint32_t flags;
00694 
00695 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
00696     if( ssl->handshake->sni_key_cert != NULL )
00697         list = ssl->handshake->sni_key_cert;
00698     else
00699 #endif
00700         list = ssl->conf->key_cert;
00701 
00702     if( pk_alg == MBEDTLS_PK_NONE )
00703         return( 0 );
00704 
00705     MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite requires certificate" ) );
00706 
00707     if( list == NULL )
00708     {
00709         MBEDTLS_SSL_DEBUG_MSG( 3, ( "server has no certificate" ) );
00710         return( -1 );
00711     }
00712 
00713     for( cur = list; cur != NULL; cur = cur->next )
00714     {
00715         MBEDTLS_SSL_DEBUG_CRT( 3, "candidate certificate chain, certificate",
00716                           cur->cert );
00717 
00718         if( ! mbedtls_pk_can_do( cur->key, pk_alg ) )
00719         {
00720             MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate mismatch: key type" ) );
00721             continue;
00722         }
00723 
00724         /*
00725          * This avoids sending the client a cert it'll reject based on
00726          * keyUsage or other extensions.
00727          *
00728          * It also allows the user to provision different certificates for
00729          * different uses based on keyUsage, eg if they want to avoid signing
00730          * and decrypting with the same RSA key.
00731          */
00732         if( mbedtls_ssl_check_cert_usage( cur->cert, ciphersuite_info,
00733                                   MBEDTLS_SSL_IS_SERVER, &flags ) != 0 )
00734         {
00735             MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate mismatch: "
00736                                 "(extended) key usage extension" ) );
00737             continue;
00738         }
00739 
00740 #if defined(MBEDTLS_ECDSA_C)
00741         if( pk_alg == MBEDTLS_PK_ECDSA &&
00742             ssl_check_key_curve( cur->key, ssl->handshake->curves ) != 0 )
00743         {
00744             MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate mismatch: elliptic curve" ) );
00745             continue;
00746         }
00747 #endif
00748 
00749         /*
00750          * Try to select a SHA-1 certificate for pre-1.2 clients, but still
00751          * present them a SHA-higher cert rather than failing if it's the only
00752          * one we got that satisfies the other conditions.
00753          */
00754         if( ssl->minor_ver < MBEDTLS_SSL_MINOR_VERSION_3 &&
00755             cur->cert->sig_md != MBEDTLS_MD_SHA1 )
00756         {
00757             if( fallback == NULL )
00758                 fallback = cur;
00759             {
00760                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "certificate not preferred: "
00761                                     "sha-2 with pre-TLS 1.2 client" ) );
00762             continue;
00763             }
00764         }
00765 
00766         /* If we get there, we got a winner */
00767         break;
00768     }
00769 
00770     if( cur == NULL )
00771         cur = fallback;
00772 
00773     /* Do not update ssl->handshake->key_cert unless there is a match */
00774     if( cur != NULL )
00775     {
00776         ssl->handshake->key_cert = cur;
00777         MBEDTLS_SSL_DEBUG_CRT( 3, "selected certificate chain, certificate",
00778                           ssl->handshake->key_cert->cert );
00779         return( 0 );
00780     }
00781 
00782     return( -1 );
00783 }
00784 #endif /* MBEDTLS_X509_CRT_PARSE_C */
00785 
00786 /*
00787  * Check if a given ciphersuite is suitable for use with our config/keys/etc
00788  * Sets ciphersuite_info only if the suite matches.
00789  */
00790 static int ssl_ciphersuite_match( mbedtls_ssl_context *ssl, int suite_id,
00791                                   const mbedtls_ssl_ciphersuite_t **ciphersuite_info )
00792 {
00793     const mbedtls_ssl_ciphersuite_t *suite_info;
00794 
00795 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
00796     defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)    
00797     mbedtls_pk_type_t sig_type;
00798 #endif
00799 
00800     suite_info = mbedtls_ssl_ciphersuite_from_id( suite_id );
00801     if( suite_info == NULL )
00802     {
00803         MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
00804         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
00805     }
00806 
00807     MBEDTLS_SSL_DEBUG_MSG( 3, ( "trying ciphersuite: %s", suite_info->name ) );
00808 
00809     if( suite_info->min_minor_ver > ssl->minor_ver ||
00810         suite_info->max_minor_ver < ssl->minor_ver )
00811     {
00812         MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: version" ) );
00813         return( 0 );
00814     }
00815 
00816 #if defined(MBEDTLS_SSL_PROTO_DTLS)
00817     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
00818         ( suite_info->flags & MBEDTLS_CIPHERSUITE_NODTLS ) )
00819         return( 0 );
00820 #endif
00821 
00822 #if defined(MBEDTLS_ARC4_C)
00823     if( ssl->conf->arc4_disabled == MBEDTLS_SSL_ARC4_DISABLED &&
00824             suite_info->cipher == MBEDTLS_CIPHER_ARC4_128 )
00825     {
00826         MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: rc4" ) );
00827         return( 0 );
00828     }
00829 #endif
00830 
00831 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
00832     if( suite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE &&
00833         ( ssl->handshake->cli_exts & MBEDTLS_TLS_EXT_ECJPAKE_KKPP_OK ) == 0 )
00834     {
00835         MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: ecjpake "
00836                                     "not configured or ext missing" ) );
00837         return( 0 );
00838     }
00839 #endif
00840 
00841 
00842 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C)
00843     if( mbedtls_ssl_ciphersuite_uses_ec( suite_info ) &&
00844         ( ssl->handshake->curves == NULL ||
00845           ssl->handshake->curves[0] == NULL ) )
00846     {
00847         MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: "
00848                             "no common elliptic curve" ) );
00849         return( 0 );
00850     }
00851 #endif
00852 
00853 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
00854     /* If the ciphersuite requires a pre-shared key and we don't
00855      * have one, skip it now rather than failing later */
00856     if( mbedtls_ssl_ciphersuite_uses_psk( suite_info ) &&
00857         ssl->conf->f_psk == NULL &&
00858         ( ssl->conf->psk == NULL || ssl->conf->psk_identity == NULL ||
00859           ssl->conf->psk_identity_len == 0 || ssl->conf->psk_len == 0 ) )
00860     {
00861         MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: no pre-shared key" ) );
00862         return( 0 );
00863     }
00864 #endif
00865 
00866 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
00867     defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
00868     /* If the ciphersuite requires signing, check whether
00869      * a suitable hash algorithm is present. */
00870     if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
00871     {
00872         sig_type = mbedtls_ssl_get_ciphersuite_sig_alg( suite_info );
00873         if( sig_type != MBEDTLS_PK_NONE &&
00874             mbedtls_ssl_sig_hash_set_find( &ssl->handshake->hash_algs, sig_type ) == MBEDTLS_MD_NONE )
00875         {
00876             MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: no suitable hash algorithm "
00877                                         "for signature algorithm %d", sig_type ) );
00878             return( 0 );
00879         }
00880     }
00881 
00882 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
00883           MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
00884 
00885 #if defined(MBEDTLS_X509_CRT_PARSE_C)
00886     /*
00887      * Final check: if ciphersuite requires us to have a
00888      * certificate/key of a particular type:
00889      * - select the appropriate certificate if we have one, or
00890      * - try the next ciphersuite if we don't
00891      * This must be done last since we modify the key_cert list.
00892      */
00893     if( ssl_pick_cert( ssl, suite_info ) != 0 )
00894     {
00895         MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciphersuite mismatch: "
00896                             "no suitable certificate" ) );
00897         return( 0 );
00898     }
00899 #endif
00900 
00901     *ciphersuite_info = suite_info;
00902     return( 0 );
00903 }
00904 
00905 #if defined(MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO)
00906 static int ssl_parse_client_hello_v2( mbedtls_ssl_context *ssl )
00907 {
00908     int ret, got_common_suite;
00909     unsigned int i, j;
00910     size_t n;
00911     unsigned int ciph_len, sess_len, chal_len;
00912     unsigned char *buf, *p;
00913     const int *ciphersuites;
00914     const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
00915 
00916     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse client hello v2" ) );
00917 
00918 #if defined(MBEDTLS_SSL_RENEGOTIATION)
00919     if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
00920     {
00921         MBEDTLS_SSL_DEBUG_MSG( 1, ( "client hello v2 illegal for renegotiation" ) );
00922         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00923                                         MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
00924         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00925     }
00926 #endif /* MBEDTLS_SSL_RENEGOTIATION */
00927 
00928     buf = ssl->in_hdr;
00929 
00930     MBEDTLS_SSL_DEBUG_BUF( 4, "record header", buf, 5 );
00931 
00932     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v2, message type: %d",
00933                    buf[2] ) );
00934     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v2, message len.: %d",
00935                    ( ( buf[0] & 0x7F ) << 8 ) | buf[1] ) );
00936     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v2, max. version: [%d:%d]",
00937                    buf[3], buf[4] ) );
00938 
00939     /*
00940      * SSLv2 Client Hello
00941      *
00942      * Record layer:
00943      *     0  .   1   message length
00944      *
00945      * SSL layer:
00946      *     2  .   2   message type
00947      *     3  .   4   protocol version
00948      */
00949     if( buf[2] != MBEDTLS_SSL_HS_CLIENT_HELLO ||
00950         buf[3] != MBEDTLS_SSL_MAJOR_VERSION_3 )
00951     {
00952         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
00953         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00954     }
00955 
00956     n = ( ( buf[0] << 8 ) | buf[1] ) & 0x7FFF;
00957 
00958     if( n < 17 || n > 512 )
00959     {
00960         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
00961         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
00962     }
00963 
00964     ssl->major_ver = MBEDTLS_SSL_MAJOR_VERSION_3;
00965     ssl->minor_ver = ( buf[4] <= ssl->conf->max_minor_ver )
00966                      ? buf[4]  : ssl->conf->max_minor_ver;
00967 
00968     if( ssl->minor_ver < ssl->conf->min_minor_ver )
00969     {
00970         MBEDTLS_SSL_DEBUG_MSG( 1, ( "client only supports ssl smaller than minimum"
00971                             " [%d:%d] < [%d:%d]",
00972                             ssl->major_ver, ssl->minor_ver,
00973                             ssl->conf->min_major_ver, ssl->conf->min_minor_ver ) );
00974 
00975         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
00976                                      MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
00977         return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
00978     }
00979 
00980     ssl->handshake->max_major_ver = buf[3];
00981     ssl->handshake->max_minor_ver = buf[4];
00982 
00983     if( ( ret = mbedtls_ssl_fetch_input( ssl, 2 + n ) ) != 0 )
00984     {
00985         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
00986         return( ret );
00987     }
00988 
00989     ssl->handshake->update_checksum( ssl, buf + 2, n );
00990 
00991     buf = ssl->in_msg;
00992     n = ssl->in_left - 5;
00993 
00994     /*
00995      *    0  .   1   ciphersuitelist length
00996      *    2  .   3   session id length
00997      *    4  .   5   challenge length
00998      *    6  .  ..   ciphersuitelist
00999      *   ..  .  ..   session id
01000      *   ..  .  ..   challenge
01001      */
01002     MBEDTLS_SSL_DEBUG_BUF( 4, "record contents", buf, n );
01003 
01004     ciph_len = ( buf[0] << 8 ) | buf[1];
01005     sess_len = ( buf[2] << 8 ) | buf[3];
01006     chal_len = ( buf[4] << 8 ) | buf[5];
01007 
01008     MBEDTLS_SSL_DEBUG_MSG( 3, ( "ciph_len: %d, sess_len: %d, chal_len: %d",
01009                    ciph_len, sess_len, chal_len ) );
01010 
01011     /*
01012      * Make sure each parameter length is valid
01013      */
01014     if( ciph_len < 3 || ( ciph_len % 3 ) != 0 )
01015     {
01016         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01017         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01018     }
01019 
01020     if( sess_len > 32 )
01021     {
01022         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01023         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01024     }
01025 
01026     if( chal_len < 8 || chal_len > 32 )
01027     {
01028         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01029         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01030     }
01031 
01032     if( n != 6 + ciph_len + sess_len + chal_len )
01033     {
01034         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01035         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01036     }
01037 
01038     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist",
01039                    buf + 6, ciph_len );
01040     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id",
01041                    buf + 6 + ciph_len, sess_len );
01042     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, challenge",
01043                    buf + 6 + ciph_len + sess_len, chal_len );
01044 
01045     p = buf + 6 + ciph_len;
01046     ssl->session_negotiate->id_len = sess_len;
01047     memset( ssl->session_negotiate->id, 0,
01048             sizeof( ssl->session_negotiate->id ) );
01049     memcpy( ssl->session_negotiate->id, p, ssl->session_negotiate->id_len );
01050 
01051     p += sess_len;
01052     memset( ssl->handshake->randbytes, 0, 64 );
01053     memcpy( ssl->handshake->randbytes + 32 - chal_len, p, chal_len );
01054 
01055     /*
01056      * Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV
01057      */
01058     for( i = 0, p = buf + 6; i < ciph_len; i += 3, p += 3 )
01059     {
01060         if( p[0] == 0 && p[1] == 0 && p[2] == MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO )
01061         {
01062             MBEDTLS_SSL_DEBUG_MSG( 3, ( "received TLS_EMPTY_RENEGOTIATION_INFO " ) );
01063 #if defined(MBEDTLS_SSL_RENEGOTIATION)
01064             if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
01065             {
01066                 MBEDTLS_SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV "
01067                                     "during renegotiation" ) );
01068 
01069                 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01070                                                 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
01071                 return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01072             }
01073 #endif /* MBEDTLS_SSL_RENEGOTIATION */
01074             ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
01075             break;
01076         }
01077     }
01078 
01079 #if defined(MBEDTLS_SSL_FALLBACK_SCSV)
01080     for( i = 0, p = buf + 6; i < ciph_len; i += 3, p += 3 )
01081     {
01082         if( p[0] == 0 &&
01083             p[1] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE >> 8 ) & 0xff ) &&
01084             p[2] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE      ) & 0xff ) )
01085         {
01086             MBEDTLS_SSL_DEBUG_MSG( 3, ( "received FALLBACK_SCSV" ) );
01087 
01088             if( ssl->minor_ver < ssl->conf->max_minor_ver )
01089             {
01090                 MBEDTLS_SSL_DEBUG_MSG( 1, ( "inapropriate fallback" ) );
01091 
01092                 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01093                                         MBEDTLS_SSL_ALERT_MSG_INAPROPRIATE_FALLBACK );
01094 
01095                 return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01096             }
01097 
01098             break;
01099         }
01100     }
01101 #endif /* MBEDTLS_SSL_FALLBACK_SCSV */
01102 
01103     got_common_suite = 0;
01104     ciphersuites = ssl->conf->ciphersuite_list[ssl->minor_ver];
01105     ciphersuite_info = NULL;
01106 #if defined(MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE)
01107     for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 )
01108         for( i = 0; ciphersuites[i] != 0; i++ )
01109 #else
01110     for( i = 0; ciphersuites[i] != 0; i++ )
01111         for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 )
01112 #endif
01113         {
01114             if( p[0] != 0 ||
01115                 p[1] != ( ( ciphersuites[i] >> 8 ) & 0xFF ) ||
01116                 p[2] != ( ( ciphersuites[i]      ) & 0xFF ) )
01117                 continue;
01118 
01119             got_common_suite = 1;
01120 
01121             if( ( ret = ssl_ciphersuite_match( ssl, ciphersuites[i],
01122                                                &ciphersuite_info ) ) != 0 )
01123                 return( ret );
01124 
01125             if( ciphersuite_info != NULL )
01126                 goto have_ciphersuite_v2;
01127         }
01128 
01129     if( got_common_suite )
01130     {
01131         MBEDTLS_SSL_DEBUG_MSG( 1, ( "got ciphersuites in common, "
01132                             "but none of them usable" ) );
01133         return( MBEDTLS_ERR_SSL_NO_USABLE_CIPHERSUITE );
01134     }
01135     else
01136     {
01137         MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no ciphersuites in common" ) );
01138         return( MBEDTLS_ERR_SSL_NO_CIPHER_CHOSEN );
01139     }
01140 
01141 have_ciphersuite_v2:
01142     MBEDTLS_SSL_DEBUG_MSG( 2, ( "selected ciphersuite: %s", ciphersuite_info->name ) );
01143 
01144     ssl->session_negotiate->ciphersuite = ciphersuites[i];
01145     ssl->transform_negotiate->ciphersuite_info = ciphersuite_info;
01146 
01147     /*
01148      * SSLv2 Client Hello relevant renegotiation security checks
01149      */
01150     if( ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
01151         ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE )
01152     {
01153         MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
01154         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01155                                         MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
01156         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01157     }
01158 
01159     ssl->in_left = 0;
01160     ssl->state++;
01161 
01162     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse client hello v2" ) );
01163 
01164     return( 0 );
01165 }
01166 #endif /* MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO */
01167 
01168 /* This function doesn't alert on errors that happen early during
01169    ClientHello parsing because they might indicate that the client is
01170    not talking SSL/TLS at all and would not understand our alert. */
01171 static int ssl_parse_client_hello( mbedtls_ssl_context *ssl )
01172 {
01173     int ret, got_common_suite;
01174     size_t i, j;
01175     size_t ciph_offset, comp_offset, ext_offset;
01176     size_t msg_len, ciph_len, sess_len, comp_len, ext_len;
01177 #if defined(MBEDTLS_SSL_PROTO_DTLS)
01178     size_t cookie_offset, cookie_len;
01179 #endif
01180     unsigned char *buf, *p, *ext;
01181 #if defined(MBEDTLS_SSL_RENEGOTIATION)
01182     int renegotiation_info_seen = 0;
01183 #endif
01184     int handshake_failure = 0;
01185     const int *ciphersuites;
01186     const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
01187     int major, minor;
01188 
01189     /* If there is no signature-algorithm extension present,
01190      * we need to fall back to the default values for allowed
01191      * signature-hash pairs. */
01192 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
01193     defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
01194     int sig_hash_alg_ext_present = 0;
01195 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
01196           MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
01197 
01198     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse client hello" ) );
01199 
01200 #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
01201 read_record_header:
01202 #endif
01203     /*
01204      * If renegotiating, then the input was read with mbedtls_ssl_read_record(),
01205      * otherwise read it ourselves manually in order to support SSLv2
01206      * ClientHello, which doesn't use the same record layer format.
01207      */
01208 #if defined(MBEDTLS_SSL_RENEGOTIATION)
01209     if( ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE )
01210 #endif
01211     {
01212         if( ( ret = mbedtls_ssl_fetch_input( ssl, 5 ) ) != 0 )
01213         {
01214             /* No alert on a read error. */
01215             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
01216             return( ret );
01217         }
01218     }
01219 
01220     buf = ssl->in_hdr;
01221 
01222 #if defined(MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO)
01223 #if defined(MBEDTLS_SSL_PROTO_DTLS)
01224     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_STREAM )
01225 #endif
01226         if( ( buf[0] & 0x80 ) != 0 )
01227             return( ssl_parse_client_hello_v2( ssl ) );
01228 #endif
01229 
01230     MBEDTLS_SSL_DEBUG_BUF( 4, "record header", buf, mbedtls_ssl_hdr_len( ssl ) );
01231 
01232     /*
01233      * SSLv3/TLS Client Hello
01234      *
01235      * Record layer:
01236      *     0  .   0   message type
01237      *     1  .   2   protocol version
01238      *     3  .   11  DTLS: epoch + record sequence number
01239      *     3  .   4   message length
01240      */
01241     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, message type: %d",
01242                    buf[0] ) );
01243 
01244     if( buf[0] != MBEDTLS_SSL_MSG_HANDSHAKE )
01245     {
01246         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01247         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01248     }
01249 
01250     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, message len.: %d",
01251                    ( ssl->in_len[0] << 8 ) | ssl->in_len[1] ) );
01252 
01253     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, protocol version: [%d:%d]",
01254                    buf[1], buf[2] ) );
01255 
01256     mbedtls_ssl_read_version( &major, &minor, ssl->conf->transport, buf + 1 );
01257 
01258     /* According to RFC 5246 Appendix E.1, the version here is typically
01259      * "{03,00}, the lowest version number supported by the client, [or] the
01260      * value of ClientHello.client_version", so the only meaningful check here
01261      * is the major version shouldn't be less than 3 */
01262     if( major < MBEDTLS_SSL_MAJOR_VERSION_3 )
01263     {
01264         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01265         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01266     }
01267 
01268     /* For DTLS if this is the initial handshake, remember the client sequence
01269      * number to use it in our next message (RFC 6347 4.2.1) */
01270 #if defined(MBEDTLS_SSL_PROTO_DTLS)
01271     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM
01272 #if defined(MBEDTLS_SSL_RENEGOTIATION)
01273         && ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE
01274 #endif
01275         )
01276     {
01277         /* Epoch should be 0 for initial handshakes */
01278         if( ssl->in_ctr[0] != 0 || ssl->in_ctr[1] != 0 )
01279         {
01280             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01281             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01282         }
01283 
01284         memcpy( ssl->out_ctr + 2, ssl->in_ctr + 2, 6 );
01285 
01286 #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
01287         if( mbedtls_ssl_dtls_replay_check( ssl ) != 0 )
01288         {
01289             MBEDTLS_SSL_DEBUG_MSG( 1, ( "replayed record, discarding" ) );
01290             ssl->next_record_offset = 0;
01291             ssl->in_left = 0;
01292             goto read_record_header;
01293         }
01294 
01295         /* No MAC to check yet, so we can update right now */
01296         mbedtls_ssl_dtls_replay_update( ssl );
01297 #endif
01298     }
01299 #endif /* MBEDTLS_SSL_PROTO_DTLS */
01300 
01301     msg_len = ( ssl->in_len[0] << 8 ) | ssl->in_len[1];
01302 
01303 #if defined(MBEDTLS_SSL_RENEGOTIATION)
01304     if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
01305     {
01306         /* Set by mbedtls_ssl_read_record() */
01307         msg_len = ssl->in_hslen;
01308     }
01309     else
01310 #endif
01311     {
01312         if( msg_len > MBEDTLS_SSL_MAX_CONTENT_LEN )
01313         {
01314             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01315             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01316         }
01317 
01318         if( ( ret = mbedtls_ssl_fetch_input( ssl,
01319                        mbedtls_ssl_hdr_len( ssl ) + msg_len ) ) != 0 )
01320         {
01321             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_fetch_input", ret );
01322             return( ret );
01323         }
01324 
01325     /* Done reading this record, get ready for the next one */
01326 #if defined(MBEDTLS_SSL_PROTO_DTLS)
01327         if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
01328             ssl->next_record_offset = msg_len + mbedtls_ssl_hdr_len( ssl );
01329         else
01330 #endif
01331             ssl->in_left = 0;
01332     }
01333 
01334     buf = ssl->in_msg;
01335 
01336     MBEDTLS_SSL_DEBUG_BUF( 4, "record contents", buf, msg_len );
01337 
01338     ssl->handshake->update_checksum( ssl, buf, msg_len );
01339 
01340     /*
01341      * Handshake layer:
01342      *     0  .   0   handshake type
01343      *     1  .   3   handshake length
01344      *     4  .   5   DTLS only: message seqence number
01345      *     6  .   8   DTLS only: fragment offset
01346      *     9  .  11   DTLS only: fragment length
01347      */
01348     if( msg_len < mbedtls_ssl_hs_hdr_len( ssl ) )
01349     {
01350         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01351         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01352     }
01353 
01354     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, handshake type: %d", buf[0] ) );
01355 
01356     if( buf[0] != MBEDTLS_SSL_HS_CLIENT_HELLO )
01357     {
01358         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01359         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01360     }
01361 
01362     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, handshake len.: %d",
01363                    ( buf[1] << 16 ) | ( buf[2] << 8 ) | buf[3] ) );
01364 
01365     /* We don't support fragmentation of ClientHello (yet?) */
01366     if( buf[1] != 0 ||
01367         msg_len != mbedtls_ssl_hs_hdr_len( ssl ) + ( ( buf[2] << 8 ) | buf[3] ) )
01368     {
01369         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01370         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01371     }
01372 
01373 #if defined(MBEDTLS_SSL_PROTO_DTLS)
01374     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
01375     {
01376         /*
01377          * Copy the client's handshake message_seq on initial handshakes,
01378          * check sequence number on renego.
01379          */
01380 #if defined(MBEDTLS_SSL_RENEGOTIATION)
01381         if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
01382         {
01383             /* This couldn't be done in ssl_prepare_handshake_record() */
01384             unsigned int cli_msg_seq = ( ssl->in_msg[4] << 8 ) |
01385                                          ssl->in_msg[5];
01386 
01387             if( cli_msg_seq != ssl->handshake->in_msg_seq )
01388             {
01389                 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message_seq: "
01390                                     "%d (expected %d)", cli_msg_seq,
01391                                     ssl->handshake->in_msg_seq ) );
01392                 return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01393             }
01394 
01395             ssl->handshake->in_msg_seq++;
01396         }
01397         else
01398 #endif
01399         {
01400             unsigned int cli_msg_seq = ( ssl->in_msg[4] << 8 ) |
01401                                          ssl->in_msg[5];
01402             ssl->handshake->out_msg_seq = cli_msg_seq;
01403             ssl->handshake->in_msg_seq  = cli_msg_seq + 1;
01404         }
01405 
01406         /*
01407          * For now we don't support fragmentation, so make sure
01408          * fragment_offset == 0 and fragment_length == length
01409          */
01410         if( ssl->in_msg[6] != 0 || ssl->in_msg[7] != 0 || ssl->in_msg[8] != 0 ||
01411             memcmp( ssl->in_msg + 1, ssl->in_msg + 9, 3 ) != 0 )
01412         {
01413             MBEDTLS_SSL_DEBUG_MSG( 1, ( "ClientHello fragmentation not supported" ) );
01414             return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
01415         }
01416     }
01417 #endif /* MBEDTLS_SSL_PROTO_DTLS */
01418 
01419     buf += mbedtls_ssl_hs_hdr_len( ssl );
01420     msg_len -= mbedtls_ssl_hs_hdr_len( ssl );
01421 
01422     /*
01423      * ClientHello layer:
01424      *     0  .   1   protocol version
01425      *     2  .  33   random bytes (starting with 4 bytes of Unix time)
01426      *    34  .  35   session id length (1 byte)
01427      *    35  . 34+x  session id
01428      *   35+x . 35+x  DTLS only: cookie length (1 byte)
01429      *   36+x .  ..   DTLS only: cookie
01430      *    ..  .  ..   ciphersuite list length (2 bytes)
01431      *    ..  .  ..   ciphersuite list
01432      *    ..  .  ..   compression alg. list length (1 byte)
01433      *    ..  .  ..   compression alg. list
01434      *    ..  .  ..   extensions length (2 bytes, optional)
01435      *    ..  .  ..   extensions (optional)
01436      */
01437 
01438     /*
01439      * Minimal length (with everything empty and extensions ommitted) is
01440      * 2 + 32 + 1 + 2 + 1 = 38 bytes. Check that first, so that we can
01441      * read at least up to session id length without worrying.
01442      */
01443     if( msg_len < 38 )
01444     {
01445         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01446         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01447     }
01448 
01449     /*
01450      * Check and save the protocol version
01451      */
01452     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, version", buf, 2 );
01453 
01454     mbedtls_ssl_read_version( &ssl->major_ver, &ssl->minor_ver,
01455                       ssl->conf->transport, buf );
01456 
01457     ssl->handshake->max_major_ver = ssl->major_ver;
01458     ssl->handshake->max_minor_ver = ssl->minor_ver;
01459 
01460     if( ssl->major_ver < ssl->conf->min_major_ver ||
01461         ssl->minor_ver < ssl->conf->min_minor_ver )
01462     {
01463         MBEDTLS_SSL_DEBUG_MSG( 1, ( "client only supports ssl smaller than minimum"
01464                             " [%d:%d] < [%d:%d]",
01465                             ssl->major_ver, ssl->minor_ver,
01466                             ssl->conf->min_major_ver, ssl->conf->min_minor_ver ) );
01467         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01468                                      MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
01469         return( MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION );
01470     }
01471 
01472     if( ssl->major_ver > ssl->conf->max_major_ver )
01473     {
01474         ssl->major_ver = ssl->conf->max_major_ver;
01475         ssl->minor_ver = ssl->conf->max_minor_ver;
01476     }
01477     else if( ssl->minor_ver > ssl->conf->max_minor_ver )
01478         ssl->minor_ver = ssl->conf->max_minor_ver;
01479 
01480     /*
01481      * Save client random (inc. Unix time)
01482      */
01483     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes", buf + 2, 32 );
01484 
01485     memcpy( ssl->handshake->randbytes, buf + 2, 32 );
01486 
01487     /*
01488      * Check the session ID length and save session ID
01489      */
01490     sess_len = buf[34];
01491 
01492     if( sess_len > sizeof( ssl->session_negotiate->id ) ||
01493         sess_len + 34 + 2 > msg_len ) /* 2 for cipherlist length field */
01494     {
01495         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01496         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01497                                         MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
01498         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01499     }
01500 
01501     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, session id", buf + 35, sess_len );
01502 
01503     ssl->session_negotiate->id_len = sess_len;
01504     memset( ssl->session_negotiate->id, 0,
01505             sizeof( ssl->session_negotiate->id ) );
01506     memcpy( ssl->session_negotiate->id, buf + 35,
01507             ssl->session_negotiate->id_len );
01508 
01509     /*
01510      * Check the cookie length and content
01511      */
01512 #if defined(MBEDTLS_SSL_PROTO_DTLS)
01513     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
01514     {
01515         cookie_offset = 35 + sess_len;
01516         cookie_len = buf[cookie_offset];
01517 
01518         if( cookie_offset + 1 + cookie_len + 2 > msg_len )
01519         {
01520             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01521             mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01522                                             MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION );
01523             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01524         }
01525 
01526         MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, cookie",
01527                        buf + cookie_offset + 1, cookie_len );
01528 
01529 #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
01530         if( ssl->conf->f_cookie_check != NULL
01531 #if defined(MBEDTLS_SSL_RENEGOTIATION)
01532             && ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE
01533 #endif
01534             )
01535         {
01536             if( ssl->conf->f_cookie_check( ssl->conf->p_cookie,
01537                                      buf + cookie_offset + 1, cookie_len,
01538                                      ssl->cli_id, ssl->cli_id_len ) != 0 )
01539             {
01540                 MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification failed" ) );
01541                 ssl->handshake->verify_cookie_len = 1;
01542             }
01543             else
01544             {
01545                 MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification passed" ) );
01546                 ssl->handshake->verify_cookie_len = 0;
01547             }
01548         }
01549         else
01550 #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */
01551         {
01552             /* We know we didn't send a cookie, so it should be empty */
01553             if( cookie_len != 0 )
01554             {
01555                 /* This may be an attacker's probe, so don't send an alert */
01556                 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01557                 return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01558             }
01559 
01560             MBEDTLS_SSL_DEBUG_MSG( 2, ( "cookie verification skipped" ) );
01561         }
01562 
01563     /*
01564      * Check the ciphersuitelist length (will be parsed later)
01565      */
01566         ciph_offset = cookie_offset + 1 + cookie_len;
01567     }
01568     else
01569 #endif /* MBEDTLS_SSL_PROTO_DTLS */
01570         ciph_offset = 35 + sess_len;
01571 
01572     ciph_len = ( buf[ciph_offset + 0] << 8 )
01573              | ( buf[ciph_offset + 1]      );
01574 
01575     if( ciph_len < 2 ||
01576         ciph_len + 2 + ciph_offset + 1 > msg_len || /* 1 for comp. alg. len */
01577         ( ciph_len % 2 ) != 0 )
01578     {
01579         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01580         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01581                                         MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
01582         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01583     }
01584 
01585     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist",
01586                    buf + ciph_offset + 2,  ciph_len );
01587 
01588     /*
01589      * Check the compression algorithms length and pick one
01590      */
01591     comp_offset = ciph_offset + 2 + ciph_len;
01592 
01593     comp_len = buf[comp_offset];
01594 
01595     if( comp_len < 1 ||
01596         comp_len > 16 ||
01597         comp_len + comp_offset + 1 > msg_len )
01598     {
01599         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01600         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01601                                         MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
01602         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01603     }
01604 
01605     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, compression",
01606                       buf + comp_offset + 1, comp_len );
01607 
01608     ssl->session_negotiate->compression = MBEDTLS_SSL_COMPRESS_NULL;
01609 #if defined(MBEDTLS_ZLIB_SUPPORT)
01610     for( i = 0; i < comp_len; ++i )
01611     {
01612         if( buf[comp_offset + 1 + i] == MBEDTLS_SSL_COMPRESS_DEFLATE )
01613         {
01614             ssl->session_negotiate->compression = MBEDTLS_SSL_COMPRESS_DEFLATE;
01615             break;
01616         }
01617     }
01618 #endif
01619 
01620     /* See comments in ssl_write_client_hello() */
01621 #if defined(MBEDTLS_SSL_PROTO_DTLS)
01622     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
01623         ssl->session_negotiate->compression = MBEDTLS_SSL_COMPRESS_NULL;
01624 #endif
01625 
01626     /* Do not parse the extensions if the protocol is SSLv3 */
01627 #if defined(MBEDTLS_SSL_PROTO_SSL3)
01628     if( ( ssl->major_ver != 3 ) || ( ssl->minor_ver != 0 ) )
01629     {
01630 #endif
01631         /*
01632          * Check the extension length
01633          */
01634         ext_offset = comp_offset + 1 + comp_len;
01635         if( msg_len > ext_offset )
01636         {
01637             if( msg_len < ext_offset + 2 )
01638             {
01639                 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01640                 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01641                                                 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
01642                 return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01643             }
01644 
01645             ext_len = ( buf[ext_offset + 0] << 8 )
01646                     | ( buf[ext_offset + 1]      );
01647 
01648             if( ( ext_len > 0 && ext_len < 4 ) ||
01649                 msg_len != ext_offset + 2 + ext_len )
01650             {
01651                 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01652                 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01653                                                 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
01654                 return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01655             }
01656         }
01657         else
01658             ext_len = 0;
01659 
01660         ext = buf + ext_offset + 2;
01661         MBEDTLS_SSL_DEBUG_BUF( 3, "client hello extensions", ext, ext_len );
01662 
01663         while( ext_len != 0 )
01664         {
01665             unsigned int ext_id   = ( ( ext[0] <<  8 )
01666                                     | ( ext[1]       ) );
01667             unsigned int ext_size = ( ( ext[2] <<  8 )
01668                                     | ( ext[3]       ) );
01669 
01670             if( ext_size + 4 > ext_len )
01671             {
01672                 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01673                 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01674                                                 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
01675                 return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01676             }
01677             switch( ext_id )
01678             {
01679 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
01680             case MBEDTLS_TLS_EXT_SERVERNAME:
01681                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found ServerName extension" ) );
01682                 if( ssl->conf->f_sni == NULL )
01683                     break;
01684 
01685                 ret = ssl_parse_servername_ext( ssl, ext + 4, ext_size );
01686                 if( ret != 0 )
01687                     return( ret );
01688                 break;
01689 #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
01690 
01691             case MBEDTLS_TLS_EXT_RENEGOTIATION_INFO:
01692                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) );
01693 #if defined(MBEDTLS_SSL_RENEGOTIATION)
01694                 renegotiation_info_seen = 1;
01695 #endif
01696 
01697                 ret = ssl_parse_renegotiation_info( ssl, ext + 4, ext_size );
01698                 if( ret != 0 )
01699                     return( ret );
01700                 break;
01701 
01702 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
01703     defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
01704             case MBEDTLS_TLS_EXT_SIG_ALG:
01705                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found signature_algorithms extension" ) );
01706 
01707                 ret = ssl_parse_signature_algorithms_ext( ssl, ext + 4, ext_size );
01708                 if( ret != 0 )
01709                     return( ret );
01710 
01711                 sig_hash_alg_ext_present = 1;
01712                 break;
01713 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
01714           MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
01715 
01716 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
01717     defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
01718             case MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES:
01719                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found supported elliptic curves extension" ) );
01720 
01721                 ret = ssl_parse_supported_elliptic_curves( ssl, ext + 4, ext_size );
01722                 if( ret != 0 )
01723                     return( ret );
01724                 break;
01725 
01726             case MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS:
01727                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found supported point formats extension" ) );
01728                 ssl->handshake->cli_exts |= MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT;
01729 
01730                 ret = ssl_parse_supported_point_formats( ssl, ext + 4, ext_size );
01731                 if( ret != 0 )
01732                     return( ret );
01733                 break;
01734 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C ||
01735           MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
01736 
01737 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
01738             case MBEDTLS_TLS_EXT_ECJPAKE_KKPP:
01739                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found ecjpake kkpp extension" ) );
01740 
01741                 ret = ssl_parse_ecjpake_kkpp( ssl, ext + 4, ext_size );
01742                 if( ret != 0 )
01743                     return( ret );
01744                 break;
01745 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
01746 
01747 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
01748             case MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH:
01749                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found max fragment length extension" ) );
01750 
01751                 ret = ssl_parse_max_fragment_length_ext( ssl, ext + 4, ext_size );
01752                 if( ret != 0 )
01753                     return( ret );
01754                 break;
01755 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
01756 
01757 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
01758             case MBEDTLS_TLS_EXT_TRUNCATED_HMAC:
01759                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found truncated hmac extension" ) );
01760 
01761                 ret = ssl_parse_truncated_hmac_ext( ssl, ext + 4, ext_size );
01762                 if( ret != 0 )
01763                     return( ret );
01764                 break;
01765 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
01766 
01767 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
01768             case MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC:
01769                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found encrypt then mac extension" ) );
01770 
01771                 ret = ssl_parse_encrypt_then_mac_ext( ssl, ext + 4, ext_size );
01772                 if( ret != 0 )
01773                     return( ret );
01774                 break;
01775 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
01776 
01777 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
01778             case MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET:
01779                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found extended master secret extension" ) );
01780 
01781                 ret = ssl_parse_extended_ms_ext( ssl, ext + 4, ext_size );
01782                 if( ret != 0 )
01783                     return( ret );
01784                 break;
01785 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
01786 
01787 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
01788             case MBEDTLS_TLS_EXT_SESSION_TICKET:
01789                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found session ticket extension" ) );
01790 
01791                 ret = ssl_parse_session_ticket_ext( ssl, ext + 4, ext_size );
01792                 if( ret != 0 )
01793                     return( ret );
01794                 break;
01795 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
01796 
01797 #if defined(MBEDTLS_SSL_ALPN)
01798             case MBEDTLS_TLS_EXT_ALPN:
01799                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found alpn extension" ) );
01800 
01801                 ret = ssl_parse_alpn_ext( ssl, ext + 4, ext_size );
01802                 if( ret != 0 )
01803                     return( ret );
01804                 break;
01805 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
01806 
01807             default:
01808                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)",
01809                                ext_id ) );
01810             }
01811 
01812             ext_len -= 4 + ext_size;
01813             ext += 4 + ext_size;
01814 
01815             if( ext_len > 0 && ext_len < 4 )
01816             {
01817                 MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
01818                 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01819                                                 MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
01820                 return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01821             }
01822         }
01823 #if defined(MBEDTLS_SSL_PROTO_SSL3)
01824     }
01825 #endif
01826 
01827 #if defined(MBEDTLS_SSL_FALLBACK_SCSV)
01828     for( i = 0, p = buf + ciph_offset + 2; i < ciph_len; i += 2, p += 2 )
01829     {
01830         if( p[0] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE >> 8 ) & 0xff ) &&
01831             p[1] == (unsigned char)( ( MBEDTLS_SSL_FALLBACK_SCSV_VALUE      ) & 0xff ) )
01832         {
01833             MBEDTLS_SSL_DEBUG_MSG( 2, ( "received FALLBACK_SCSV" ) );
01834 
01835             if( ssl->minor_ver < ssl->conf->max_minor_ver )
01836             {
01837                 MBEDTLS_SSL_DEBUG_MSG( 1, ( "inapropriate fallback" ) );
01838 
01839                 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01840                                         MBEDTLS_SSL_ALERT_MSG_INAPROPRIATE_FALLBACK );
01841 
01842                 return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01843             }
01844 
01845             break;
01846         }
01847     }
01848 #endif /* MBEDTLS_SSL_FALLBACK_SCSV */
01849 
01850 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
01851     defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
01852 
01853     /*
01854      * Try to fall back to default hash SHA1 if the client
01855      * hasn't provided any preferred signature-hash combinations.
01856      */
01857     if( sig_hash_alg_ext_present == 0 )
01858     {
01859         mbedtls_md_type_t md_default = MBEDTLS_MD_SHA1;
01860 
01861         if( mbedtls_ssl_check_sig_hash( ssl, md_default ) != 0 )
01862             md_default = MBEDTLS_MD_NONE;
01863 
01864         mbedtls_ssl_sig_hash_set_const_hash( &ssl->handshake->hash_algs, md_default );
01865     }
01866 
01867 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
01868           MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
01869 
01870     /*
01871      * Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV
01872      */
01873     for( i = 0, p = buf + ciph_offset + 2; i < ciph_len; i += 2, p += 2 )
01874     {
01875         if( p[0] == 0 && p[1] == MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO )
01876         {
01877             MBEDTLS_SSL_DEBUG_MSG( 3, ( "received TLS_EMPTY_RENEGOTIATION_INFO " ) );
01878 #if defined(MBEDTLS_SSL_RENEGOTIATION)
01879             if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
01880             {
01881                 MBEDTLS_SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV "
01882                                             "during renegotiation" ) );
01883                 mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01884                                                 MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
01885                 return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01886             }
01887 #endif
01888             ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
01889             break;
01890         }
01891     }
01892 
01893     /*
01894      * Renegotiation security checks
01895      */
01896     if( ssl->secure_renegotiation != MBEDTLS_SSL_SECURE_RENEGOTIATION &&
01897         ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE )
01898     {
01899         MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
01900         handshake_failure = 1;
01901     }
01902 #if defined(MBEDTLS_SSL_RENEGOTIATION)
01903     else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
01904              ssl->secure_renegotiation == MBEDTLS_SSL_SECURE_RENEGOTIATION &&
01905              renegotiation_info_seen == 0 )
01906     {
01907         MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension missing (secure)" ) );
01908         handshake_failure = 1;
01909     }
01910     else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
01911              ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
01912              ssl->conf->allow_legacy_renegotiation == MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION )
01913     {
01914         MBEDTLS_SSL_DEBUG_MSG( 1, ( "legacy renegotiation not allowed" ) );
01915         handshake_failure = 1;
01916     }
01917     else if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
01918              ssl->secure_renegotiation == MBEDTLS_SSL_LEGACY_RENEGOTIATION &&
01919              renegotiation_info_seen == 1 )
01920     {
01921         MBEDTLS_SSL_DEBUG_MSG( 1, ( "renegotiation_info extension present (legacy)" ) );
01922         handshake_failure = 1;
01923     }
01924 #endif /* MBEDTLS_SSL_RENEGOTIATION */
01925 
01926     if( handshake_failure == 1 )
01927     {
01928         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01929                                         MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
01930         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO );
01931     }
01932 
01933     /*
01934      * Search for a matching ciphersuite
01935      * (At the end because we need information from the EC-based extensions
01936      * and certificate from the SNI callback triggered by the SNI extension.)
01937      */
01938     got_common_suite = 0;
01939     ciphersuites = ssl->conf->ciphersuite_list[ssl->minor_ver];
01940     ciphersuite_info = NULL;
01941 #if defined(MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE)
01942     for( j = 0, p = buf + ciph_offset + 2; j < ciph_len; j += 2, p += 2 )
01943         for( i = 0; ciphersuites[i] != 0; i++ )
01944 #else
01945     for( i = 0; ciphersuites[i] != 0; i++ )
01946         for( j = 0, p = buf + ciph_offset + 2; j < ciph_len; j += 2, p += 2 )
01947 #endif
01948         {
01949             if( p[0] != ( ( ciphersuites[i] >> 8 ) & 0xFF ) ||
01950                 p[1] != ( ( ciphersuites[i]      ) & 0xFF ) )
01951                 continue;
01952 
01953             got_common_suite = 1;
01954 
01955             if( ( ret = ssl_ciphersuite_match( ssl, ciphersuites[i],
01956                                                &ciphersuite_info ) ) != 0 )
01957                 return( ret );
01958 
01959             if( ciphersuite_info != NULL )
01960                 goto have_ciphersuite;
01961         }
01962 
01963     if( got_common_suite )
01964     {
01965         MBEDTLS_SSL_DEBUG_MSG( 1, ( "got ciphersuites in common, "
01966                             "but none of them usable" ) );
01967         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01968                                         MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
01969         return( MBEDTLS_ERR_SSL_NO_USABLE_CIPHERSUITE );
01970     }
01971     else
01972     {
01973         MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no ciphersuites in common" ) );
01974         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
01975                                         MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
01976         return( MBEDTLS_ERR_SSL_NO_CIPHER_CHOSEN );
01977     }
01978 
01979 have_ciphersuite:
01980     MBEDTLS_SSL_DEBUG_MSG( 2, ( "selected ciphersuite: %s", ciphersuite_info->name ) );
01981 
01982     ssl->session_negotiate->ciphersuite = ciphersuites[i];
01983     ssl->transform_negotiate->ciphersuite_info = ciphersuite_info;
01984 
01985     ssl->state++;
01986 
01987 #if defined(MBEDTLS_SSL_PROTO_DTLS)
01988     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
01989         mbedtls_ssl_recv_flight_completed( ssl );
01990 #endif
01991 
01992     /* Debugging-only output for testsuite */
01993 #if defined(MBEDTLS_DEBUG_C)                         && \
01994     defined(MBEDTLS_SSL_PROTO_TLS1_2)                && \
01995     defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
01996     if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
01997     {
01998         mbedtls_pk_type_t sig_alg = mbedtls_ssl_get_ciphersuite_sig_alg( ciphersuite_info );
01999         if( sig_alg != MBEDTLS_PK_NONE )
02000         {
02001             mbedtls_md_type_t md_alg = mbedtls_ssl_sig_hash_set_find( &ssl->handshake->hash_algs,
02002                                                                   sig_alg );
02003             MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext: %d",
02004                                         mbedtls_ssl_hash_from_md_alg( md_alg ) ) );
02005         }
02006         else
02007         {
02008             MBEDTLS_SSL_DEBUG_MSG( 3, ( "no hash algorithm for signature algorithm "
02009                                         "%d - should not happen", sig_alg ) );
02010         }
02011     }
02012 #endif
02013 
02014     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse client hello" ) );
02015 
02016     return( 0 );
02017 }
02018 
02019 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
02020 static void ssl_write_truncated_hmac_ext( mbedtls_ssl_context *ssl,
02021                                           unsigned char *buf,
02022                                           size_t *olen )
02023 {
02024     unsigned char *p = buf;
02025 
02026     if( ssl->session_negotiate->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED )
02027     {
02028         *olen = 0;
02029         return;
02030     }
02031 
02032     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding truncated hmac extension" ) );
02033 
02034     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_TRUNCATED_HMAC >> 8 ) & 0xFF );
02035     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_TRUNCATED_HMAC      ) & 0xFF );
02036 
02037     *p++ = 0x00;
02038     *p++ = 0x00;
02039 
02040     *olen = 4;
02041 }
02042 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
02043 
02044 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
02045 static void ssl_write_encrypt_then_mac_ext( mbedtls_ssl_context *ssl,
02046                                             unsigned char *buf,
02047                                             size_t *olen )
02048 {
02049     unsigned char *p = buf;
02050     const mbedtls_ssl_ciphersuite_t *suite = NULL;
02051     const mbedtls_cipher_info_t *cipher = NULL;
02052 
02053     if( ssl->session_negotiate->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
02054         ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
02055     {
02056         *olen = 0;
02057         return;
02058     }
02059 
02060     /*
02061      * RFC 7366: "If a server receives an encrypt-then-MAC request extension
02062      * from a client and then selects a stream or Authenticated Encryption
02063      * with Associated Data (AEAD) ciphersuite, it MUST NOT send an
02064      * encrypt-then-MAC response extension back to the client."
02065      */
02066     if( ( suite = mbedtls_ssl_ciphersuite_from_id(
02067                     ssl->session_negotiate->ciphersuite ) ) == NULL ||
02068         ( cipher = mbedtls_cipher_info_from_type( suite->cipher ) ) == NULL ||
02069         cipher->mode != MBEDTLS_MODE_CBC )
02070     {
02071         *olen = 0;
02072         return;
02073     }
02074 
02075     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding encrypt then mac extension" ) );
02076 
02077     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC >> 8 ) & 0xFF );
02078     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC      ) & 0xFF );
02079 
02080     *p++ = 0x00;
02081     *p++ = 0x00;
02082 
02083     *olen = 4;
02084 }
02085 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
02086 
02087 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
02088 static void ssl_write_extended_ms_ext( mbedtls_ssl_context *ssl,
02089                                        unsigned char *buf,
02090                                        size_t *olen )
02091 {
02092     unsigned char *p = buf;
02093 
02094     if( ssl->handshake->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED ||
02095         ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
02096     {
02097         *olen = 0;
02098         return;
02099     }
02100 
02101     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding extended master secret "
02102                         "extension" ) );
02103 
02104     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET >> 8 ) & 0xFF );
02105     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET      ) & 0xFF );
02106 
02107     *p++ = 0x00;
02108     *p++ = 0x00;
02109 
02110     *olen = 4;
02111 }
02112 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
02113 
02114 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
02115 static void ssl_write_session_ticket_ext( mbedtls_ssl_context *ssl,
02116                                           unsigned char *buf,
02117                                           size_t *olen )
02118 {
02119     unsigned char *p = buf;
02120 
02121     if( ssl->handshake->new_session_ticket == 0 )
02122     {
02123         *olen = 0;
02124         return;
02125     }
02126 
02127     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding session ticket extension" ) );
02128 
02129     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET >> 8 ) & 0xFF );
02130     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET      ) & 0xFF );
02131 
02132     *p++ = 0x00;
02133     *p++ = 0x00;
02134 
02135     *olen = 4;
02136 }
02137 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
02138 
02139 static void ssl_write_renegotiation_ext( mbedtls_ssl_context *ssl,
02140                                          unsigned char *buf,
02141                                          size_t *olen )
02142 {
02143     unsigned char *p = buf;
02144 
02145     if( ssl->secure_renegotiation != MBEDTLS_SSL_SECURE_RENEGOTIATION )
02146     {
02147         *olen = 0;
02148         return;
02149     }
02150 
02151     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, secure renegotiation extension" ) );
02152 
02153     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_RENEGOTIATION_INFO >> 8 ) & 0xFF );
02154     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_RENEGOTIATION_INFO      ) & 0xFF );
02155 
02156 #if defined(MBEDTLS_SSL_RENEGOTIATION)
02157     if( ssl->renego_status != MBEDTLS_SSL_INITIAL_HANDSHAKE )
02158     {
02159         *p++ = 0x00;
02160         *p++ = ( ssl->verify_data_len * 2 + 1 ) & 0xFF;
02161         *p++ = ssl->verify_data_len * 2 & 0xFF;
02162 
02163         memcpy( p, ssl->peer_verify_data, ssl->verify_data_len );
02164         p += ssl->verify_data_len;
02165         memcpy( p, ssl->own_verify_data, ssl->verify_data_len );
02166         p += ssl->verify_data_len;
02167     }
02168     else
02169 #endif /* MBEDTLS_SSL_RENEGOTIATION */
02170     {
02171         *p++ = 0x00;
02172         *p++ = 0x01;
02173         *p++ = 0x00;
02174     }
02175 
02176     *olen = p - buf;
02177 }
02178 
02179 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
02180 static void ssl_write_max_fragment_length_ext( mbedtls_ssl_context *ssl,
02181                                                unsigned char *buf,
02182                                                size_t *olen )
02183 {
02184     unsigned char *p = buf;
02185 
02186     if( ssl->session_negotiate->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE )
02187     {
02188         *olen = 0;
02189         return;
02190     }
02191 
02192     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, max_fragment_length extension" ) );
02193 
02194     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH >> 8 ) & 0xFF );
02195     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH      ) & 0xFF );
02196 
02197     *p++ = 0x00;
02198     *p++ = 1;
02199 
02200     *p++ = ssl->session_negotiate->mfl_code;
02201 
02202     *olen = 5;
02203 }
02204 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
02205 
02206 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
02207     defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
02208 static void ssl_write_supported_point_formats_ext( mbedtls_ssl_context *ssl,
02209                                                    unsigned char *buf,
02210                                                    size_t *olen )
02211 {
02212     unsigned char *p = buf;
02213     ((void) ssl);
02214 
02215     if( ( ssl->handshake->cli_exts &
02216           MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT ) == 0 )
02217     {
02218         *olen = 0;
02219         return;
02220     }
02221 
02222     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, supported_point_formats extension" ) );
02223 
02224     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS >> 8 ) & 0xFF );
02225     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS      ) & 0xFF );
02226 
02227     *p++ = 0x00;
02228     *p++ = 2;
02229 
02230     *p++ = 1;
02231     *p++ = MBEDTLS_ECP_PF_UNCOMPRESSED;
02232 
02233     *olen = 6;
02234 }
02235 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C || MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
02236 
02237 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
02238 static void ssl_write_ecjpake_kkpp_ext( mbedtls_ssl_context *ssl,
02239                                         unsigned char *buf,
02240                                         size_t *olen )
02241 {
02242     int ret;
02243     unsigned char *p = buf;
02244     const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
02245     size_t kkpp_len;
02246 
02247     *olen = 0;
02248 
02249     /* Skip costly computation if not needed */
02250     if( ssl->transform_negotiate->ciphersuite_info->key_exchange !=
02251         MBEDTLS_KEY_EXCHANGE_ECJPAKE )
02252         return;
02253 
02254     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, ecjpake kkpp extension" ) );
02255 
02256     if( end - p < 4 )
02257     {
02258         MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
02259         return;
02260     }
02261 
02262     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP >> 8 ) & 0xFF );
02263     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ECJPAKE_KKPP      ) & 0xFF );
02264 
02265     ret = mbedtls_ecjpake_write_round_one( &ssl->handshake->ecjpake_ctx,
02266                                         p + 2, end - p - 2, &kkpp_len,
02267                                         ssl->conf->f_rng, ssl->conf->p_rng );
02268     if( ret != 0 )
02269     {
02270         MBEDTLS_SSL_DEBUG_RET( 1 , "mbedtls_ecjpake_write_round_one", ret );
02271         return;
02272     }
02273 
02274     *p++ = (unsigned char)( ( kkpp_len >> 8 ) & 0xFF );
02275     *p++ = (unsigned char)( ( kkpp_len      ) & 0xFF );
02276 
02277     *olen = kkpp_len + 4;
02278 }
02279 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
02280 
02281 #if defined(MBEDTLS_SSL_ALPN )
02282 static void ssl_write_alpn_ext( mbedtls_ssl_context *ssl,
02283                                 unsigned char *buf, size_t *olen )
02284 {
02285     if( ssl->alpn_chosen == NULL )
02286     {
02287         *olen = 0;
02288         return;
02289     }
02290 
02291     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding alpn extension" ) );
02292 
02293     /*
02294      * 0 . 1    ext identifier
02295      * 2 . 3    ext length
02296      * 4 . 5    protocol list length
02297      * 6 . 6    protocol name length
02298      * 7 . 7+n  protocol name
02299      */
02300     buf[0] = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN >> 8 ) & 0xFF );
02301     buf[1] = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN      ) & 0xFF );
02302 
02303     *olen = 7 + strlen( ssl->alpn_chosen );
02304 
02305     buf[2] = (unsigned char)( ( ( *olen - 4 ) >> 8 ) & 0xFF );
02306     buf[3] = (unsigned char)( ( ( *olen - 4 )      ) & 0xFF );
02307 
02308     buf[4] = (unsigned char)( ( ( *olen - 6 ) >> 8 ) & 0xFF );
02309     buf[5] = (unsigned char)( ( ( *olen - 6 )      ) & 0xFF );
02310 
02311     buf[6] = (unsigned char)( ( ( *olen - 7 )      ) & 0xFF );
02312 
02313     memcpy( buf + 7, ssl->alpn_chosen, *olen - 7 );
02314 }
02315 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C */
02316 
02317 #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
02318 static int ssl_write_hello_verify_request( mbedtls_ssl_context *ssl )
02319 {
02320     int ret;
02321     unsigned char *p = ssl->out_msg + 4;
02322     unsigned char *cookie_len_byte;
02323 
02324     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write hello verify request" ) );
02325 
02326     /*
02327      * struct {
02328      *   ProtocolVersion server_version;
02329      *   opaque cookie<0..2^8-1>;
02330      * } HelloVerifyRequest;
02331      */
02332 
02333     /* The RFC is not clear on this point, but sending the actual negotiated
02334      * version looks like the most interoperable thing to do. */
02335     mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver,
02336                        ssl->conf->transport, p );
02337     MBEDTLS_SSL_DEBUG_BUF( 3, "server version", p, 2 );
02338     p += 2;
02339 
02340     /* If we get here, f_cookie_check is not null */
02341     if( ssl->conf->f_cookie_write == NULL )
02342     {
02343         MBEDTLS_SSL_DEBUG_MSG( 1, ( "inconsistent cookie callbacks" ) );
02344         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
02345     }
02346 
02347     /* Skip length byte until we know the length */
02348     cookie_len_byte = p++;
02349 
02350     if( ( ret = ssl->conf->f_cookie_write( ssl->conf->p_cookie,
02351                                      &p, ssl->out_buf + MBEDTLS_SSL_BUFFER_LEN,
02352                                      ssl->cli_id, ssl->cli_id_len ) ) != 0 )
02353     {
02354         MBEDTLS_SSL_DEBUG_RET( 1, "f_cookie_write", ret );
02355         return( ret );
02356     }
02357 
02358     *cookie_len_byte = (unsigned char)( p - ( cookie_len_byte + 1 ) );
02359 
02360     MBEDTLS_SSL_DEBUG_BUF( 3, "cookie sent", cookie_len_byte + 1, *cookie_len_byte );
02361 
02362     ssl->out_msglen  = p - ssl->out_msg;
02363     ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
02364     ssl->out_msg[0]  = MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST;
02365 
02366     ssl->state = MBEDTLS_SSL_SERVER_HELLO_VERIFY_REQUEST_SENT;
02367 
02368     if( ( ret = mbedtls_ssl_write_record( ssl ) ) != 0 )
02369     {
02370         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
02371         return( ret );
02372     }
02373 
02374     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write hello verify request" ) );
02375 
02376     return( 0 );
02377 }
02378 #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */
02379 
02380 static int ssl_write_server_hello( mbedtls_ssl_context *ssl )
02381 {
02382 #if defined(MBEDTLS_HAVE_TIME)
02383     mbedtls_time_t t;
02384 #endif
02385     int ret;
02386     size_t olen, ext_len = 0, n;
02387     unsigned char *buf, *p;
02388 
02389     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write server hello" ) );
02390 
02391 #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
02392     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
02393         ssl->handshake->verify_cookie_len != 0 )
02394     {
02395         MBEDTLS_SSL_DEBUG_MSG( 2, ( "client hello was not authenticated" ) );
02396         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server hello" ) );
02397 
02398         return( ssl_write_hello_verify_request( ssl ) );
02399     }
02400 #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */
02401 
02402     if( ssl->conf->f_rng == NULL )
02403     {
02404         MBEDTLS_SSL_DEBUG_MSG( 1, ( "no RNG provided") );
02405         return( MBEDTLS_ERR_SSL_NO_RNG );
02406     }
02407 
02408     /*
02409      *     0  .   0   handshake type
02410      *     1  .   3   handshake length
02411      *     4  .   5   protocol version
02412      *     6  .   9   UNIX time()
02413      *    10  .  37   random bytes
02414      */
02415     buf = ssl->out_msg;
02416     p = buf + 4;
02417 
02418     mbedtls_ssl_write_version( ssl->major_ver, ssl->minor_ver,
02419                        ssl->conf->transport, p );
02420     p += 2;
02421 
02422     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen version: [%d:%d]",
02423                         buf[4], buf[5] ) );
02424 
02425 #if defined(MBEDTLS_HAVE_TIME)
02426     t = mbedtls_time( NULL );
02427     *p++ = (unsigned char)( t >> 24 );
02428     *p++ = (unsigned char)( t >> 16 );
02429     *p++ = (unsigned char)( t >>  8 );
02430     *p++ = (unsigned char)( t       );
02431 
02432     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu", t ) );
02433 #else
02434     if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p, 4 ) ) != 0 )
02435         return( ret );
02436 
02437     p += 4;
02438 #endif /* MBEDTLS_HAVE_TIME */
02439 
02440     if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p, 28 ) ) != 0 )
02441         return( ret );
02442 
02443     p += 28;
02444 
02445     memcpy( ssl->handshake->randbytes + 32, buf + 6, 32 );
02446 
02447     MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 6, 32 );
02448 
02449     /*
02450      * Resume is 0  by default, see ssl_handshake_init().
02451      * It may be already set to 1 by ssl_parse_session_ticket_ext().
02452      * If not, try looking up session ID in our cache.
02453      */
02454     if( ssl->handshake->resume == 0 &&
02455 #if defined(MBEDTLS_SSL_RENEGOTIATION)
02456         ssl->renego_status == MBEDTLS_SSL_INITIAL_HANDSHAKE &&
02457 #endif
02458         ssl->session_negotiate->id_len != 0 &&
02459         ssl->conf->f_get_cache != NULL &&
02460         ssl->conf->f_get_cache( ssl->conf->p_cache, ssl->session_negotiate ) == 0 )
02461     {
02462         MBEDTLS_SSL_DEBUG_MSG( 3, ( "session successfully restored from cache" ) );
02463         ssl->handshake->resume = 1;
02464     }
02465 
02466     if( ssl->handshake->resume == 0 )
02467     {
02468         /*
02469          * New session, create a new session id,
02470          * unless we're about to issue a session ticket
02471          */
02472         ssl->state++;
02473 
02474 #if defined(MBEDTLS_HAVE_TIME)
02475         ssl->session_negotiate->start = mbedtls_time( NULL );
02476 #endif
02477 
02478 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
02479         if( ssl->handshake->new_session_ticket != 0 )
02480         {
02481             ssl->session_negotiate->id_len = n = 0;
02482             memset( ssl->session_negotiate->id, 0, 32 );
02483         }
02484         else
02485 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
02486         {
02487             ssl->session_negotiate->id_len = n = 32;
02488             if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, ssl->session_negotiate->id,
02489                                     n ) ) != 0 )
02490                 return( ret );
02491         }
02492     }
02493     else
02494     {
02495         /*
02496          * Resuming a session
02497          */
02498         n = ssl->session_negotiate->id_len;
02499         ssl->state = MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC;
02500 
02501         if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
02502         {
02503             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
02504             return( ret );
02505         }
02506     }
02507 
02508     /*
02509      *    38  .  38     session id length
02510      *    39  . 38+n    session id
02511      *   39+n . 40+n    chosen ciphersuite
02512      *   41+n . 41+n    chosen compression alg.
02513      *   42+n . 43+n    extensions length
02514      *   44+n . 43+n+m  extensions
02515      */
02516     *p++ = (unsigned char) ssl->session_negotiate->id_len;
02517     memcpy( p, ssl->session_negotiate->id, ssl->session_negotiate->id_len );
02518     p += ssl->session_negotiate->id_len;
02519 
02520     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %d", n ) );
02521     MBEDTLS_SSL_DEBUG_BUF( 3,   "server hello, session id", buf + 39, n );
02522     MBEDTLS_SSL_DEBUG_MSG( 3, ( "%s session has been resumed",
02523                    ssl->handshake->resume ? "a" : "no" ) );
02524 
02525     *p++ = (unsigned char)( ssl->session_negotiate->ciphersuite >> 8 );
02526     *p++ = (unsigned char)( ssl->session_negotiate->ciphersuite      );
02527     *p++ = (unsigned char)( ssl->session_negotiate->compression      );
02528 
02529     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %s",
02530            mbedtls_ssl_get_ciphersuite_name( ssl->session_negotiate->ciphersuite ) ) );
02531     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: 0x%02X",
02532                    ssl->session_negotiate->compression ) );
02533 
02534     /* Do not write the extensions if the protocol is SSLv3 */
02535 #if defined(MBEDTLS_SSL_PROTO_SSL3)
02536     if( ( ssl->major_ver != 3 ) || ( ssl->minor_ver != 0 ) )
02537     {
02538 #endif
02539 
02540     /*
02541      *  First write extensions, then the total length
02542      */
02543     ssl_write_renegotiation_ext( ssl, p + 2 + ext_len, &olen );
02544     ext_len += olen;
02545 
02546 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
02547     ssl_write_max_fragment_length_ext( ssl, p + 2 + ext_len, &olen );
02548     ext_len += olen;
02549 #endif
02550 
02551 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
02552     ssl_write_truncated_hmac_ext( ssl, p + 2 + ext_len, &olen );
02553     ext_len += olen;
02554 #endif
02555 
02556 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
02557     ssl_write_encrypt_then_mac_ext( ssl, p + 2 + ext_len, &olen );
02558     ext_len += olen;
02559 #endif
02560 
02561 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
02562     ssl_write_extended_ms_ext( ssl, p + 2 + ext_len, &olen );
02563     ext_len += olen;
02564 #endif
02565 
02566 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
02567     ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen );
02568     ext_len += olen;
02569 #endif
02570 
02571 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
02572     defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
02573     ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen );
02574     ext_len += olen;
02575 #endif
02576 
02577 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
02578     ssl_write_ecjpake_kkpp_ext( ssl, p + 2 + ext_len, &olen );
02579     ext_len += olen;
02580 #endif
02581 
02582 #if defined(MBEDTLS_SSL_ALPN)
02583     ssl_write_alpn_ext( ssl, p + 2 + ext_len, &olen );
02584     ext_len += olen;
02585 #endif
02586 
02587     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, total extension length: %d", ext_len ) );
02588 
02589     if( ext_len > 0 )
02590     {
02591         *p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF );
02592         *p++ = (unsigned char)( ( ext_len      ) & 0xFF );
02593         p += ext_len;
02594     }
02595 
02596 #if defined(MBEDTLS_SSL_PROTO_SSL3)
02597     }
02598 #endif
02599 
02600     ssl->out_msglen  = p - buf;
02601     ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
02602     ssl->out_msg[0]  = MBEDTLS_SSL_HS_SERVER_HELLO;
02603 
02604     ret = mbedtls_ssl_write_record( ssl );
02605 
02606     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server hello" ) );
02607 
02608     return( ret );
02609 }
02610 
02611 #if !defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)       && \
02612     !defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)   && \
02613     !defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED)  && \
02614     !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
02615     !defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)&& \
02616     !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
02617 static int ssl_write_certificate_request( mbedtls_ssl_context *ssl )
02618 {
02619     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
02620         ssl->transform_negotiate->ciphersuite_info;
02621 
02622     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) );
02623 
02624     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
02625         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
02626         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
02627         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
02628         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
02629     {
02630         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) );
02631         ssl->state++;
02632         return( 0 );
02633     }
02634 
02635     MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
02636     return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
02637 }
02638 #else
02639 static int ssl_write_certificate_request( mbedtls_ssl_context *ssl )
02640 {
02641     int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
02642     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
02643         ssl->transform_negotiate->ciphersuite_info;
02644     size_t dn_size, total_dn_size; /* excluding length bytes */
02645     size_t ct_len, sa_len; /* including length bytes */
02646     unsigned char *buf, *p;
02647     const unsigned char * const end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
02648     const mbedtls_x509_crt *crt;
02649     int authmode;
02650 
02651     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) );
02652 
02653     ssl->state++;
02654 
02655 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
02656     if( ssl->handshake->sni_authmode != MBEDTLS_SSL_VERIFY_UNSET )
02657         authmode = ssl->handshake->sni_authmode;
02658     else
02659 #endif
02660         authmode = ssl->conf->authmode;
02661 
02662     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
02663         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
02664         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
02665         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
02666         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE ||
02667         authmode == MBEDTLS_SSL_VERIFY_NONE )
02668     {
02669         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) );
02670         return( 0 );
02671     }
02672 
02673     /*
02674      *     0  .   0   handshake type
02675      *     1  .   3   handshake length
02676      *     4  .   4   cert type count
02677      *     5  .. m-1  cert types
02678      *     m  .. m+1  sig alg length (TLS 1.2 only)
02679      *    m+1 .. n-1  SignatureAndHashAlgorithms (TLS 1.2 only)
02680      *     n  .. n+1  length of all DNs
02681      *    n+2 .. n+3  length of DN 1
02682      *    n+4 .. ...  Distinguished Name #1
02683      *    ... .. ...  length of DN 2, etc.
02684      */
02685     buf = ssl->out_msg;
02686     p = buf + 4;
02687 
02688     /*
02689      * Supported certificate types
02690      *
02691      *     ClientCertificateType certificate_types<1..2^8-1>;
02692      *     enum { (255) } ClientCertificateType;
02693      */
02694     ct_len = 0;
02695 
02696 #if defined(MBEDTLS_RSA_C)
02697     p[1 + ct_len++] = MBEDTLS_SSL_CERT_TYPE_RSA_SIGN;
02698 #endif
02699 #if defined(MBEDTLS_ECDSA_C)
02700     p[1 + ct_len++] = MBEDTLS_SSL_CERT_TYPE_ECDSA_SIGN;
02701 #endif
02702 
02703     p[0] = (unsigned char) ct_len++;
02704     p += ct_len;
02705 
02706     sa_len = 0;
02707 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
02708     /*
02709      * Add signature_algorithms for verify (TLS 1.2)
02710      *
02711      *     SignatureAndHashAlgorithm supported_signature_algorithms<2..2^16-2>;
02712      *
02713      *     struct {
02714      *           HashAlgorithm hash;
02715      *           SignatureAlgorithm signature;
02716      *     } SignatureAndHashAlgorithm;
02717      *
02718      *     enum { (255) } HashAlgorithm;
02719      *     enum { (255) } SignatureAlgorithm;
02720      */
02721     if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
02722     {
02723         const int *cur;
02724 
02725         /*
02726          * Supported signature algorithms
02727          */
02728         for( cur = ssl->conf->sig_hashes; *cur != MBEDTLS_MD_NONE; cur++ )
02729         {
02730             unsigned char hash = mbedtls_ssl_hash_from_md_alg( *cur );
02731 
02732             if( MBEDTLS_SSL_HASH_NONE == hash || mbedtls_ssl_set_calc_verify_md( ssl, hash ) )
02733                 continue;
02734 
02735 #if defined(MBEDTLS_RSA_C)
02736             p[2 + sa_len++] = hash;
02737             p[2 + sa_len++] = MBEDTLS_SSL_SIG_RSA;
02738 #endif
02739 #if defined(MBEDTLS_ECDSA_C)
02740             p[2 + sa_len++] = hash;
02741             p[2 + sa_len++] = MBEDTLS_SSL_SIG_ECDSA;
02742 #endif
02743         }
02744 
02745         p[0] = (unsigned char)( sa_len >> 8 );
02746         p[1] = (unsigned char)( sa_len      );
02747         sa_len += 2;
02748         p += sa_len;
02749     }
02750 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
02751 
02752     /*
02753      * DistinguishedName certificate_authorities<0..2^16-1>;
02754      * opaque DistinguishedName<1..2^16-1>;
02755      */
02756     p += 2;
02757 
02758     total_dn_size = 0;
02759 
02760     if( ssl->conf->cert_req_ca_list ==  MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED )
02761     {
02762 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
02763         if( ssl->handshake->sni_ca_chain != NULL )
02764             crt = ssl->handshake->sni_ca_chain;
02765         else
02766 #endif
02767             crt = ssl->conf->ca_chain;
02768 
02769         while( crt != NULL && crt->version != 0 )
02770         {
02771             dn_size = crt->subject_raw.len;
02772 
02773             if( end < p ||
02774                 (size_t)( end - p ) < dn_size ||
02775                 (size_t)( end - p ) < 2 + dn_size )
02776             {
02777                 MBEDTLS_SSL_DEBUG_MSG( 1, ( "skipping CAs: buffer too short" ) );
02778                 break;
02779             }
02780 
02781             *p++ = (unsigned char)( dn_size >> 8 );
02782             *p++ = (unsigned char)( dn_size      );
02783             memcpy( p, crt->subject_raw.p, dn_size );
02784             p += dn_size;
02785 
02786             MBEDTLS_SSL_DEBUG_BUF( 3, "requested DN", p - dn_size, dn_size );
02787 
02788             total_dn_size += 2 + dn_size;
02789             crt = crt->next;
02790         }
02791     }
02792 
02793     ssl->out_msglen  = p - buf;
02794     ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
02795     ssl->out_msg[0]  = MBEDTLS_SSL_HS_CERTIFICATE_REQUEST;
02796     ssl->out_msg[4 + ct_len + sa_len] = (unsigned char)( total_dn_size  >> 8 );
02797     ssl->out_msg[5 + ct_len + sa_len] = (unsigned char)( total_dn_size       );
02798 
02799     ret = mbedtls_ssl_write_record( ssl );
02800 
02801     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write certificate request" ) );
02802 
02803     return( ret );
02804 }
02805 #endif /* !MBEDTLS_KEY_EXCHANGE_RSA_ENABLED &&
02806           !MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED &&
02807           !MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED &&
02808           !MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED &&
02809           !MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED &&
02810           !MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
02811 
02812 #if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
02813     defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
02814 static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl )
02815 {
02816     int ret;
02817 
02818     if( ! mbedtls_pk_can_do( mbedtls_ssl_own_key( ssl ), MBEDTLS_PK_ECKEY ) )
02819     {
02820         MBEDTLS_SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) );
02821         return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
02822     }
02823 
02824     if( ( ret = mbedtls_ecdh_get_params( &ssl->handshake->ecdh_ctx,
02825                                  mbedtls_pk_ec( *mbedtls_ssl_own_key( ssl ) ),
02826                                  MBEDTLS_ECDH_OURS ) ) != 0 )
02827     {
02828         MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ecdh_get_params" ), ret );
02829         return( ret );
02830     }
02831 
02832     return( 0 );
02833 }
02834 #endif /* MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||
02835           MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
02836 
02837 static int ssl_write_server_key_exchange( mbedtls_ssl_context *ssl )
02838 {
02839     int ret;
02840     size_t n = 0;
02841     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
02842                             ssl->transform_negotiate->ciphersuite_info;
02843 
02844 #if defined(MBEDTLS_KEY_EXCHANGE__SOME_PFS__ENABLED)
02845     unsigned char *p = ssl->out_msg + 4;
02846     size_t len;
02847 #if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED)
02848     unsigned char *dig_signed = p;
02849     size_t dig_signed_len = 0;
02850 #endif /* MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED */
02851 #endif /* MBEDTLS_KEY_EXCHANGE__SOME_PFS__ENABLED */
02852 
02853     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write server key exchange" ) );
02854 
02855     /*
02856      *
02857      * Part 1: Extract static ECDH parameters and abort
02858      *         if ServerKeyExchange not needed.
02859      *
02860      */
02861 
02862     /* For suites involving ECDH, extract DH parameters
02863      * from certificate at this point. */
02864 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__ECDH_ENABLED)
02865     if( mbedtls_ssl_ciphersuite_uses_ecdh( ciphersuite_info ) )
02866     {
02867         ssl_get_ecdh_params_from_cert( ssl );
02868     }
02869 #endif /* MBEDTLS_KEY_EXCHANGE__SOME__ECDH_ENABLED */
02870 
02871     /* Key exchanges not involving ephemeral keys don't use
02872      * ServerKeyExchange, so end here. */
02873 #if defined(MBEDTLS_KEY_EXCHANGE__SOME_NON_PFS__ENABLED)
02874     if( mbedtls_ssl_ciphersuite_no_pfs( ciphersuite_info ) )
02875     {
02876         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write server key exchange" ) );
02877         ssl->state++;
02878         return( 0 );
02879     }
02880 #endif /* MBEDTLS_KEY_EXCHANGE__NON_PFS__ENABLED */
02881 
02882     /*
02883      *
02884      * Part 2: Provide key exchange parameters for chosen ciphersuite.
02885      *
02886      */
02887 
02888     /*
02889      * - ECJPAKE key exchanges
02890      */
02891 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
02892     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
02893     {
02894         const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
02895 
02896         ret = mbedtls_ecjpake_write_round_two( &ssl->handshake->ecjpake_ctx,
02897                 p, end - p, &len, ssl->conf->f_rng, ssl->conf->p_rng );
02898         if( ret != 0 )
02899         {
02900             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_write_round_two", ret );
02901             return( ret );
02902         }
02903 
02904         p += len;
02905         n += len;
02906     }
02907 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
02908 
02909     /*
02910      * For (EC)DHE key exchanges with PSK, parameters are prefixed by support
02911      * identity hint (RFC 4279, Sec. 3). Until someone needs this feature,
02912      * we use empty support identity hints here.
02913      **/
02914 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)   || \
02915     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
02916     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
02917         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
02918     {
02919         *(p++) = 0x00;
02920         *(p++) = 0x00;
02921 
02922         n += 2;
02923     }
02924 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED ||
02925           MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
02926 
02927     /*
02928      * - DHE key exchanges
02929      */
02930 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__DHE_ENABLED)
02931     if( mbedtls_ssl_ciphersuite_uses_dhe( ciphersuite_info ) )
02932     {
02933         if( ssl->conf->dhm_P.p == NULL || ssl->conf->dhm_G.p == NULL )
02934         {
02935             MBEDTLS_SSL_DEBUG_MSG( 1, ( "no DH parameters set" ) );
02936             return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
02937         }
02938 
02939         /*
02940          * Ephemeral DH parameters:
02941          *
02942          * struct {
02943          *     opaque dh_p<1..2^16-1>;
02944          *     opaque dh_g<1..2^16-1>;
02945          *     opaque dh_Ys<1..2^16-1>;
02946          * } ServerDHParams;
02947          */
02948         if( ( ret = mbedtls_dhm_set_group( &ssl->handshake->dhm_ctx,
02949                                            &ssl->conf->dhm_P,
02950                                            &ssl->conf->dhm_G ) ) != 0 )
02951         {
02952             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_set_group", ret );
02953             return( ret );
02954         }
02955 
02956         if( ( ret = mbedtls_dhm_make_params( &ssl->handshake->dhm_ctx,
02957                         (int) mbedtls_mpi_size( &ssl->handshake->dhm_ctx.P ),
02958                         p, &len, ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
02959         {
02960             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_make_params", ret );
02961             return( ret );
02962         }
02963 
02964 #if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED)        
02965         dig_signed = p;
02966         dig_signed_len = len;
02967 #endif
02968 
02969         p += len;
02970         n += len;
02971 
02972         MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: X ", &ssl->handshake->dhm_ctx.X  );
02973         MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->handshake->dhm_ctx.P  );
02974         MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->handshake->dhm_ctx.G  );
02975         MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GX", &ssl->handshake->dhm_ctx.GX );
02976     }
02977 #endif /* MBEDTLS_KEY_EXCHANGE__SOME__DHE_ENABLED */
02978 
02979     /*
02980      * - ECDHE key exchanges
02981      */
02982 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__ECDHE_ENABLED)
02983     if( mbedtls_ssl_ciphersuite_uses_ecdhe( ciphersuite_info ) )
02984     {
02985         /*
02986          * Ephemeral ECDH parameters:
02987          *
02988          * struct {
02989          *     ECParameters curve_params;
02990          *     ECPoint      public;
02991          * } ServerECDHParams;
02992          */
02993         const mbedtls_ecp_curve_info **curve = NULL;
02994         const mbedtls_ecp_group_id *gid;
02995 
02996         /* Match our preference list against the offered curves */
02997         for( gid = ssl->conf->curve_list; *gid != MBEDTLS_ECP_DP_NONE; gid++ )
02998             for( curve = ssl->handshake->curves; *curve != NULL; curve++ )
02999                 if( (*curve)->grp_id == *gid )
03000                     goto curve_matching_done;
03001 
03002 curve_matching_done:
03003         if( curve == NULL || *curve == NULL )
03004         {
03005             MBEDTLS_SSL_DEBUG_MSG( 1, ( "no matching curve for ECDHE" ) );
03006             return( MBEDTLS_ERR_SSL_NO_CIPHER_CHOSEN );
03007         }
03008 
03009         MBEDTLS_SSL_DEBUG_MSG( 2, ( "ECDHE curve: %s", (*curve)->name ) );
03010 
03011         if( ( ret = mbedtls_ecp_group_load( &ssl->handshake->ecdh_ctx.grp,
03012                                        (*curve)->grp_id ) ) != 0 )
03013         {
03014             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecp_group_load", ret );
03015             return( ret );
03016         }
03017 
03018         if( ( ret = mbedtls_ecdh_make_params( &ssl->handshake->ecdh_ctx, &len,
03019                                       p, MBEDTLS_SSL_MAX_CONTENT_LEN - n,
03020                                       ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
03021         {
03022             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_make_params", ret );
03023             return( ret );
03024         }
03025 
03026 #if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED)
03027         dig_signed     = p;
03028         dig_signed_len = len;
03029 #endif
03030 
03031         p += len;
03032         n += len;
03033 
03034         MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Q ", &ssl->handshake->ecdh_ctx.Q );
03035     }
03036 #endif /* MBEDTLS_KEY_EXCHANGE__SOME__ECDHE_ENABLED */
03037 
03038     /*
03039      *
03040      * Part 3: For key exchanges involving the server signing the
03041      *         exchange parameters, compute and add the signature here.
03042      *
03043      */
03044 #if defined(MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED)
03045     if( mbedtls_ssl_ciphersuite_uses_server_signature( ciphersuite_info ) )
03046     {
03047         size_t signature_len = 0;
03048         unsigned int hashlen = 0;
03049         unsigned char hash[64];
03050 
03051         /*
03052          * 3.1: Choose hash algorithm:
03053          * A: For TLS 1.2, obey signature-hash-algorithm extension 
03054          *    to choose appropriate hash.
03055          * B: For SSL3, TLS1.0, TLS1.1 and ECDHE_ECDSA, use SHA1
03056          *    (RFC 4492, Sec. 5.4)
03057          * C: Otherwise, use MD5 + SHA1 (RFC 4346, Sec. 7.4.3)
03058          */
03059 
03060         mbedtls_md_type_t md_alg;
03061 
03062 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
03063         mbedtls_pk_type_t sig_alg =
03064             mbedtls_ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info );
03065         if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
03066         {
03067             /* A: For TLS 1.2, obey signature-hash-algorithm extension
03068              *    (RFC 5246, Sec. 7.4.1.4.1). */
03069             if( sig_alg == MBEDTLS_PK_NONE ||
03070                 ( md_alg = mbedtls_ssl_sig_hash_set_find( &ssl->handshake->hash_algs,
03071                                                           sig_alg ) ) == MBEDTLS_MD_NONE )
03072             {
03073                 MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
03074                 /* (... because we choose a cipher suite 
03075                  *      only if there is a matching hash.) */
03076                 return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
03077             }
03078         }
03079         else
03080 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
03081 #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
03082     defined(MBEDTLS_SSL_PROTO_TLS1_1)
03083         if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA )
03084         {
03085             /* B: Default hash SHA1 */
03086             md_alg = MBEDTLS_MD_SHA1;
03087         }
03088         else
03089 #endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \
03090           MBEDTLS_SSL_PROTO_TLS1_1 */
03091         {
03092             /* C: MD5 + SHA1 */
03093             md_alg = MBEDTLS_MD_NONE;
03094         }
03095 
03096         MBEDTLS_SSL_DEBUG_MSG( 3, ( "pick hash algorithm %d for signing", md_alg ) );
03097 
03098         /*
03099          * 3.2: Compute the hash to be signed
03100          */
03101 #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
03102     defined(MBEDTLS_SSL_PROTO_TLS1_1)
03103         if( md_alg == MBEDTLS_MD_NONE )
03104         {
03105             hashlen = 36;
03106             ret = mbedtls_ssl_get_key_exchange_md_ssl_tls( ssl, hash,
03107                                                            dig_signed,
03108                                                            dig_signed_len );
03109             if( ret != 0 )
03110                 return( ret );
03111         }
03112         else
03113 #endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 || \
03114           MBEDTLS_SSL_PROTO_TLS1_1 */
03115 #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
03116     defined(MBEDTLS_SSL_PROTO_TLS1_2)
03117         if( md_alg != MBEDTLS_MD_NONE )
03118         {
03119             /* Info from md_alg will be used instead */
03120             hashlen = 0;
03121             ret = mbedtls_ssl_get_key_exchange_md_tls1_2( ssl, hash,
03122                                                           dig_signed,
03123                                                           dig_signed_len,
03124                                                           md_alg );
03125             if( ret != 0 )
03126                 return( ret );
03127         }
03128         else
03129 #endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
03130           MBEDTLS_SSL_PROTO_TLS1_2 */
03131         {
03132             MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
03133             return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
03134         }
03135 
03136         MBEDTLS_SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen != 0 ? hashlen :
03137             (unsigned int) ( mbedtls_md_get_size( mbedtls_md_info_from_type( md_alg ) ) ) );
03138 
03139         /*
03140          * 3.3: Compute and add the signature
03141          */
03142         if( mbedtls_ssl_own_key( ssl ) == NULL )
03143         {
03144             MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no private key" ) );
03145             return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
03146         }
03147 
03148 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
03149         if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
03150         {
03151             /*
03152              * For TLS 1.2, we need to specify signature and hash algorithm
03153              * explicitly through a prefix to the signature.
03154              *
03155              * struct {
03156              *    HashAlgorithm hash;
03157              *    SignatureAlgorithm signature;
03158              * } SignatureAndHashAlgorithm;
03159              *
03160              * struct {
03161              *    SignatureAndHashAlgorithm algorithm;
03162              *    opaque signature<0..2^16-1>;
03163              * } DigitallySigned;
03164              *
03165              */
03166 
03167             *(p++) = mbedtls_ssl_hash_from_md_alg( md_alg );
03168             *(p++) = mbedtls_ssl_sig_from_pk_alg( sig_alg );
03169 
03170             n += 2;
03171         }
03172 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
03173 
03174         if( ( ret = mbedtls_pk_sign( mbedtls_ssl_own_key( ssl ), md_alg, hash, hashlen,
03175                         p + 2 , &signature_len, ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
03176         {
03177             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_sign", ret );
03178             return( ret );
03179         }
03180 
03181         *(p++) = (unsigned char)( signature_len >> 8 );
03182         *(p++) = (unsigned char)( signature_len      );
03183         n += 2;
03184 
03185         MBEDTLS_SSL_DEBUG_BUF( 3, "my signature", p, signature_len );
03186 
03187         n += signature_len;
03188     }
03189 #endif /* MBEDTLS_KEY_EXCHANGE__WITH_SERVER_SIGNATURE__ENABLED */
03190 
03191     /* Done with actual work; add header and send. */
03192 
03193     ssl->out_msglen  = 4 + n;
03194     ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
03195     ssl->out_msg[0]  = MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE;
03196 
03197     ssl->state++;
03198 
03199     if( ( ret = mbedtls_ssl_write_record( ssl ) ) != 0 )
03200     {
03201         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
03202         return( ret );
03203     }
03204 
03205     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server key exchange" ) );
03206 
03207     return( 0 );
03208 }
03209 
03210 static int ssl_write_server_hello_done( mbedtls_ssl_context *ssl )
03211 {
03212     int ret;
03213 
03214     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write server hello done" ) );
03215 
03216     ssl->out_msglen  = 4;
03217     ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
03218     ssl->out_msg[0]  = MBEDTLS_SSL_HS_SERVER_HELLO_DONE;
03219 
03220     ssl->state++;
03221 
03222 #if defined(MBEDTLS_SSL_PROTO_DTLS)
03223     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
03224         mbedtls_ssl_send_flight_completed( ssl );
03225 #endif
03226 
03227     if( ( ret = mbedtls_ssl_write_record( ssl ) ) != 0 )
03228     {
03229         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
03230         return( ret );
03231     }
03232 
03233     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server hello done" ) );
03234 
03235     return( 0 );
03236 }
03237 
03238 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) ||                       \
03239     defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
03240 static int ssl_parse_client_dh_public( mbedtls_ssl_context *ssl, unsigned char **p,
03241                                        const unsigned char *end )
03242 {
03243     int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
03244     size_t n;
03245 
03246     /*
03247      * Receive G^Y mod P, premaster = (G^Y)^X mod P
03248      */
03249     if( *p + 2 > end )
03250     {
03251         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
03252         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
03253     }
03254 
03255     n = ( (*p)[0] << 8 ) | (*p)[1];
03256     *p += 2;
03257 
03258     if( *p + n > end )
03259     {
03260         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
03261         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
03262     }
03263 
03264     if( ( ret = mbedtls_dhm_read_public( &ssl->handshake->dhm_ctx, *p, n ) ) != 0 )
03265     {
03266         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_read_public", ret );
03267         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP );
03268     }
03269 
03270     *p += n;
03271 
03272     MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY );
03273 
03274     return( ret );
03275 }
03276 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
03277           MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
03278 
03279 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) ||                           \
03280     defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
03281 static int ssl_parse_encrypted_pms( mbedtls_ssl_context *ssl,
03282                                     const unsigned char *p,
03283                                     const unsigned char *end,
03284                                     size_t pms_offset )
03285 {
03286     int ret;
03287     size_t len = mbedtls_pk_get_len( mbedtls_ssl_own_key( ssl ) );
03288     unsigned char *pms = ssl->handshake->premaster + pms_offset;
03289     unsigned char ver[2];
03290     unsigned char fake_pms[48], peer_pms[48];
03291     unsigned char mask;
03292     size_t i, peer_pmslen;
03293     unsigned int diff;
03294 
03295     if( ! mbedtls_pk_can_do( mbedtls_ssl_own_key( ssl ), MBEDTLS_PK_RSA ) )
03296     {
03297         MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no RSA private key" ) );
03298         return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
03299     }
03300 
03301     /*
03302      * Decrypt the premaster using own private RSA key
03303      */
03304 #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
03305     defined(MBEDTLS_SSL_PROTO_TLS1_2)
03306     if( ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_0 )
03307     {
03308         if( *p++ != ( ( len >> 8 ) & 0xFF ) ||
03309             *p++ != ( ( len      ) & 0xFF ) )
03310         {
03311             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
03312             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
03313         }
03314     }
03315 #endif
03316 
03317     if( p + len != end )
03318     {
03319         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
03320         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
03321     }
03322 
03323     mbedtls_ssl_write_version( ssl->handshake->max_major_ver,
03324                        ssl->handshake->max_minor_ver,
03325                        ssl->conf->transport, ver );
03326 
03327     /*
03328      * Protection against Bleichenbacher's attack: invalid PKCS#1 v1.5 padding
03329      * must not cause the connection to end immediately; instead, send a
03330      * bad_record_mac later in the handshake.
03331      * Also, avoid data-dependant branches here to protect against
03332      * timing-based variants.
03333      */
03334     ret = ssl->conf->f_rng( ssl->conf->p_rng, fake_pms, sizeof( fake_pms ) );
03335     if( ret != 0 )
03336         return( ret );
03337 
03338     ret = mbedtls_pk_decrypt( mbedtls_ssl_own_key( ssl ), p, len,
03339                       peer_pms, &peer_pmslen,
03340                       sizeof( peer_pms ),
03341                       ssl->conf->f_rng, ssl->conf->p_rng );
03342 
03343     diff  = (unsigned int) ret;
03344     diff |= peer_pmslen ^ 48;
03345     diff |= peer_pms[0] ^ ver[0];
03346     diff |= peer_pms[1] ^ ver[1];
03347 
03348 #if defined(MBEDTLS_SSL_DEBUG_ALL)
03349     if( diff != 0 )
03350         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
03351 #endif
03352 
03353     if( sizeof( ssl->handshake->premaster ) < pms_offset ||
03354         sizeof( ssl->handshake->premaster ) - pms_offset < 48 )
03355     {
03356         MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
03357         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
03358     }
03359     ssl->handshake->pmslen = 48;
03360 
03361     /* mask = diff ? 0xff : 0x00 using bit operations to avoid branches */
03362     /* MSVC has a warning about unary minus on unsigned, but this is
03363      * well-defined and precisely what we want to do here */
03364 #if defined(_MSC_VER)
03365 #pragma warning( push )
03366 #pragma warning( disable : 4146 )
03367 #endif
03368     mask = - ( ( diff | - diff ) >> ( sizeof( unsigned int ) * 8 - 1 ) );
03369 #if defined(_MSC_VER)
03370 #pragma warning( pop )
03371 #endif
03372 
03373     for( i = 0; i < ssl->handshake->pmslen; i++ )
03374         pms[i] = ( mask & fake_pms[i] ) | ( (~mask) & peer_pms[i] );
03375 
03376     return( 0 );
03377 }
03378 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED ||
03379           MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
03380 
03381 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
03382 static int ssl_parse_client_psk_identity( mbedtls_ssl_context *ssl, unsigned char **p,
03383                                           const unsigned char *end )
03384 {
03385     int ret = 0;
03386     size_t n;
03387 
03388     if( ssl->conf->f_psk == NULL &&
03389         ( ssl->conf->psk == NULL || ssl->conf->psk_identity == NULL ||
03390           ssl->conf->psk_identity_len == 0 || ssl->conf->psk_len == 0 ) )
03391     {
03392         MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no pre-shared key" ) );
03393         return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
03394     }
03395 
03396     /*
03397      * Receive client pre-shared key identity name
03398      */
03399     if( end - *p < 2 )
03400     {
03401         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
03402         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
03403     }
03404 
03405     n = ( (*p)[0] << 8 ) | (*p)[1];
03406     *p += 2;
03407 
03408     if( n < 1 || n > 65535 || n > (size_t) ( end - *p ) )
03409     {
03410         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
03411         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
03412     }
03413 
03414     if( ssl->conf->f_psk != NULL )
03415     {
03416         if( ssl->conf->f_psk( ssl->conf->p_psk, ssl, *p, n ) != 0 )
03417             ret = MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY;
03418     }
03419     else
03420     {
03421         /* Identity is not a big secret since clients send it in the clear,
03422          * but treat it carefully anyway, just in case */
03423         if( n != ssl->conf->psk_identity_len ||
03424             mbedtls_ssl_safer_memcmp( ssl->conf->psk_identity, *p, n ) != 0 )
03425         {
03426             ret = MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY;
03427         }
03428     }
03429 
03430     if( ret == MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY )
03431     {
03432         MBEDTLS_SSL_DEBUG_BUF( 3, "Unknown PSK identity", *p, n );
03433         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
03434                                         MBEDTLS_SSL_ALERT_MSG_UNKNOWN_PSK_IDENTITY );
03435         return( MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY );
03436     }
03437 
03438     *p += n;
03439 
03440     return( 0 );
03441 }
03442 #endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
03443 
03444 static int ssl_parse_client_key_exchange( mbedtls_ssl_context *ssl )
03445 {
03446     int ret;
03447     const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
03448     unsigned char *p, *end;
03449 
03450     ciphersuite_info = ssl->transform_negotiate->ciphersuite_info;
03451 
03452     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse client key exchange" ) );
03453 
03454     if( ( ret = mbedtls_ssl_read_record( ssl ) ) != 0 )
03455     {
03456         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
03457         return( ret );
03458     }
03459 
03460     p = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
03461     end = ssl->in_msg + ssl->in_hslen;
03462 
03463     if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
03464     {
03465         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
03466         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
03467     }
03468 
03469     if( ssl->in_msg[0] != MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE )
03470     {
03471         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
03472         return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
03473     }
03474 
03475 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)
03476     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_RSA )
03477     {
03478         if( ( ret = ssl_parse_client_dh_public( ssl, &p, end ) ) != 0 )
03479         {
03480             MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_dh_public" ), ret );
03481             return( ret );
03482         }
03483 
03484         if( p != end )
03485         {
03486             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) );
03487             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
03488         }
03489 
03490         if( ( ret = mbedtls_dhm_calc_secret( &ssl->handshake->dhm_ctx,
03491                                       ssl->handshake->premaster,
03492                                       MBEDTLS_PREMASTER_SIZE,
03493                                      &ssl->handshake->pmslen,
03494                                       ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
03495         {
03496             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_dhm_calc_secret", ret );
03497             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_CS );
03498         }
03499 
03500         MBEDTLS_SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K  );
03501     }
03502     else
03503 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED */
03504 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||                     \
03505     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) ||                   \
03506     defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||                      \
03507     defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
03508     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_RSA ||
03509         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA ||
03510         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_RSA ||
03511         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA )
03512     {
03513         if( ( ret = mbedtls_ecdh_read_public( &ssl->handshake->ecdh_ctx,
03514                                       p, end - p) ) != 0 )
03515         {
03516             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_read_public", ret );
03517             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP );
03518         }
03519 
03520         MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Qp ", &ssl->handshake->ecdh_ctx.Qp );
03521 
03522         if( ( ret = mbedtls_ecdh_calc_secret( &ssl->handshake->ecdh_ctx,
03523                                       &ssl->handshake->pmslen,
03524                                        ssl->handshake->premaster,
03525                                        MBEDTLS_MPI_MAX_SIZE,
03526                                        ssl->conf->f_rng, ssl->conf->p_rng ) ) != 0 )
03527         {
03528             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_calc_secret", ret );
03529             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_CS );
03530         }
03531 
03532         MBEDTLS_SSL_DEBUG_MPI( 3, "ECDH: z  ", &ssl->handshake->ecdh_ctx.z );
03533     }
03534     else
03535 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
03536           MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ||
03537           MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED ||
03538           MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */
03539 #if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
03540     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK )
03541     {
03542         if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
03543         {
03544             MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
03545             return( ret );
03546         }
03547 
03548         if( p != end )
03549         {
03550             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) );
03551             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
03552         }
03553 
03554         if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl,
03555                         ciphersuite_info->key_exchange ) ) != 0 )
03556         {
03557             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret );
03558             return( ret );
03559         }
03560     }
03561     else
03562 #endif /* MBEDTLS_KEY_EXCHANGE_PSK_ENABLED */
03563 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
03564     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
03565     {
03566         if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
03567         {
03568             MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
03569             return( ret );
03570         }
03571 
03572         if( ( ret = ssl_parse_encrypted_pms( ssl, p, end, 2 ) ) != 0 )
03573         {
03574             MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_encrypted_pms" ), ret );
03575             return( ret );
03576         }
03577 
03578         if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl,
03579                         ciphersuite_info->key_exchange ) ) != 0 )
03580         {
03581             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret );
03582             return( ret );
03583         }
03584     }
03585     else
03586 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
03587 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
03588     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK )
03589     {
03590         if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
03591         {
03592             MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
03593             return( ret );
03594         }
03595         if( ( ret = ssl_parse_client_dh_public( ssl, &p, end ) ) != 0 )
03596         {
03597             MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_dh_public" ), ret );
03598             return( ret );
03599         }
03600 
03601         if( p != end )
03602         {
03603             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) );
03604             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
03605         }
03606 
03607         if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl,
03608                         ciphersuite_info->key_exchange ) ) != 0 )
03609         {
03610             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret );
03611             return( ret );
03612         }
03613     }
03614     else
03615 #endif /* MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED */
03616 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
03617     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK )
03618     {
03619         if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
03620         {
03621             MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_client_psk_identity" ), ret );
03622             return( ret );
03623         }
03624 
03625         if( ( ret = mbedtls_ecdh_read_public( &ssl->handshake->ecdh_ctx,
03626                                        p, end - p ) ) != 0 )
03627         {
03628             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecdh_read_public", ret );
03629             return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP );
03630         }
03631 
03632         MBEDTLS_SSL_DEBUG_ECP( 3, "ECDH: Qp ", &ssl->handshake->ecdh_ctx.Qp );
03633 
03634         if( ( ret = mbedtls_ssl_psk_derive_premaster( ssl,
03635                         ciphersuite_info->key_exchange ) ) != 0 )
03636         {
03637             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_psk_derive_premaster", ret );
03638             return( ret );
03639         }
03640     }
03641     else
03642 #endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED */
03643 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
03644     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA )
03645     {
03646         if( ( ret = ssl_parse_encrypted_pms( ssl, p, end, 0 ) ) != 0 )
03647         {
03648             MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_parse_parse_encrypted_pms_secret" ), ret );
03649             return( ret );
03650         }
03651     }
03652     else
03653 #endif /* MBEDTLS_KEY_EXCHANGE_RSA_ENABLED */
03654 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
03655     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
03656     {
03657         ret = mbedtls_ecjpake_read_round_two( &ssl->handshake->ecjpake_ctx,
03658                                               p, end - p );
03659         if( ret != 0 )
03660         {
03661             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_read_round_two", ret );
03662             return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
03663         }
03664 
03665         ret = mbedtls_ecjpake_derive_secret( &ssl->handshake->ecjpake_ctx,
03666                 ssl->handshake->premaster, 32, &ssl->handshake->pmslen,
03667                 ssl->conf->f_rng, ssl->conf->p_rng );
03668         if( ret != 0 )
03669         {
03670             MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ecjpake_derive_secret", ret );
03671             return( ret );
03672         }
03673     }
03674     else
03675 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
03676     {
03677         MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
03678         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
03679     }
03680 
03681     if( ( ret = mbedtls_ssl_derive_keys( ssl ) ) != 0 )
03682     {
03683         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_derive_keys", ret );
03684         return( ret );
03685     }
03686 
03687     ssl->state++;
03688 
03689     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse client key exchange" ) );
03690 
03691     return( 0 );
03692 }
03693 
03694 #if !defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)       && \
03695     !defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)   && \
03696     !defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED)  && \
03697     !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \
03698     !defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)&& \
03699     !defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
03700 static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
03701 {
03702     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
03703         ssl->transform_negotiate->ciphersuite_info;
03704 
03705     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) );
03706 
03707     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
03708         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
03709         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
03710         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
03711         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
03712     {
03713         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
03714         ssl->state++;
03715         return( 0 );
03716     }
03717 
03718     MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
03719     return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
03720 }
03721 #else
03722 static int ssl_parse_certificate_verify( mbedtls_ssl_context *ssl )
03723 {
03724     int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
03725     size_t i, sig_len;
03726     unsigned char hash[48];
03727     unsigned char *hash_start = hash;
03728     size_t hashlen;
03729 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
03730     mbedtls_pk_type_t pk_alg;
03731 #endif
03732     mbedtls_md_type_t md_alg;
03733     const mbedtls_ssl_ciphersuite_t *ciphersuite_info =
03734         ssl->transform_negotiate->ciphersuite_info;
03735 
03736     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) );
03737 
03738     if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
03739         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK ||
03740         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
03741         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
03742         ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE ||
03743         ssl->session_negotiate->peer_cert == NULL )
03744     {
03745         MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) );
03746         ssl->state++;
03747         return( 0 );
03748     }
03749 
03750     /* Read the message without adding it to the checksum */
03751     do {
03752 
03753         if( ( ret = mbedtls_ssl_read_record_layer( ssl ) ) != 0 )
03754         {
03755             MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_read_record_layer" ), ret );
03756             return( ret );
03757         }
03758 
03759         ret = mbedtls_ssl_handle_message_type( ssl );
03760 
03761     } while( MBEDTLS_ERR_SSL_NON_FATAL == ret );
03762 
03763     if( 0 != ret )
03764     {
03765         MBEDTLS_SSL_DEBUG_RET( 1, ( "mbedtls_ssl_handle_message_type" ), ret );
03766         return( ret );
03767     }
03768 
03769     ssl->state++;
03770 
03771     /* Process the message contents */
03772     if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ||
03773         ssl->in_msg[0] != MBEDTLS_SSL_HS_CERTIFICATE_VERIFY )
03774     {
03775         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
03776         return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
03777     }
03778 
03779     i = mbedtls_ssl_hs_hdr_len( ssl );
03780 
03781     /*
03782      *  struct {
03783      *     SignatureAndHashAlgorithm algorithm; -- TLS 1.2 only
03784      *     opaque signature<0..2^16-1>;
03785      *  } DigitallySigned;
03786      */
03787 #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
03788     defined(MBEDTLS_SSL_PROTO_TLS1_1)
03789     if( ssl->minor_ver != MBEDTLS_SSL_MINOR_VERSION_3 )
03790     {
03791         md_alg = MBEDTLS_MD_NONE;
03792         hashlen = 36;
03793 
03794         /* For ECDSA, use SHA-1, not MD-5 + SHA-1 */
03795         if( mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk,
03796                         MBEDTLS_PK_ECDSA ) )
03797         {
03798             hash_start += 16;
03799             hashlen -= 16;
03800             md_alg = MBEDTLS_MD_SHA1;
03801         }
03802     }
03803     else
03804 #endif /* MBEDTLS_SSL_PROTO_SSL3 || MBEDTLS_SSL_PROTO_TLS1 ||
03805           MBEDTLS_SSL_PROTO_TLS1_1 */
03806 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
03807     if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
03808     {
03809         if( i + 2 > ssl->in_hslen )
03810         {
03811             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
03812             return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
03813         }
03814 
03815         /*
03816          * Hash
03817          */
03818         md_alg = mbedtls_ssl_md_alg_from_hash( ssl->in_msg[i] );
03819 
03820         if( md_alg == MBEDTLS_MD_NONE || mbedtls_ssl_set_calc_verify_md( ssl, ssl->in_msg[i] ) )
03821         {
03822             MBEDTLS_SSL_DEBUG_MSG( 1, ( "peer not adhering to requested sig_alg"
03823                                 " for verify message" ) );
03824             return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
03825         }
03826 
03827 #if !defined(MBEDTLS_MD_SHA1)
03828         if( MBEDTLS_MD_SHA1 == md_alg )
03829             hash_start += 16;
03830 #endif
03831 
03832         /* Info from md_alg will be used instead */
03833         hashlen = 0;
03834 
03835         i++;
03836 
03837         /*
03838          * Signature
03839          */
03840         if( ( pk_alg = mbedtls_ssl_pk_alg_from_sig( ssl->in_msg[i] ) )
03841                         == MBEDTLS_PK_NONE )
03842         {
03843             MBEDTLS_SSL_DEBUG_MSG( 1, ( "peer not adhering to requested sig_alg"
03844                                 " for verify message" ) );
03845             return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
03846         }
03847 
03848         /*
03849          * Check the certificate's key type matches the signature alg
03850          */
03851         if( ! mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk, pk_alg ) )
03852         {
03853             MBEDTLS_SSL_DEBUG_MSG( 1, ( "sig_alg doesn't match cert key" ) );
03854             return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
03855         }
03856 
03857         i++;
03858     }
03859     else
03860 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
03861     {
03862         MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
03863         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
03864     }
03865 
03866     if( i + 2 > ssl->in_hslen )
03867     {
03868         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
03869         return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
03870     }
03871 
03872     sig_len = ( ssl->in_msg[i] << 8 ) | ssl->in_msg[i+1];
03873     i += 2;
03874 
03875     if( i + sig_len != ssl->in_hslen )
03876     {
03877         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) );
03878         return( MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY );
03879     }
03880 
03881     /* Calculate hash and verify signature */
03882     ssl->handshake->calc_verify( ssl, hash );
03883 
03884     if( ( ret = mbedtls_pk_verify( &ssl->session_negotiate->peer_cert->pk,
03885                            md_alg, hash_start, hashlen,
03886                            ssl->in_msg + i, sig_len ) ) != 0 )
03887     {
03888         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_pk_verify", ret );
03889         return( ret );
03890     }
03891 
03892     mbedtls_ssl_update_handshake_status( ssl );
03893 
03894     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate verify" ) );
03895 
03896     return( ret );
03897 }
03898 #endif /* !MBEDTLS_KEY_EXCHANGE_RSA_ENABLED &&
03899           !MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED &&
03900           !MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED &&
03901           !MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED &&
03902           !MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED &&
03903           !MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
03904 
03905 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
03906 static int ssl_write_new_session_ticket( mbedtls_ssl_context *ssl )
03907 {
03908     int ret;
03909     size_t tlen;
03910     uint32_t lifetime;
03911 
03912     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write new session ticket" ) );
03913 
03914     ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
03915     ssl->out_msg[0]  = MBEDTLS_SSL_HS_NEW_SESSION_TICKET;
03916 
03917     /*
03918      * struct {
03919      *     uint32 ticket_lifetime_hint;
03920      *     opaque ticket<0..2^16-1>;
03921      * } NewSessionTicket;
03922      *
03923      * 4  .  7   ticket_lifetime_hint (0 = unspecified)
03924      * 8  .  9   ticket_len (n)
03925      * 10 .  9+n ticket content
03926      */
03927 
03928     if( ( ret = ssl->conf->f_ticket_write( ssl->conf->p_ticket,
03929                                 ssl->session_negotiate,
03930                                 ssl->out_msg + 10,
03931                                 ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN,
03932                                 &tlen, &lifetime ) ) != 0 )
03933     {
03934         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_ticket_write", ret );
03935         tlen = 0;
03936     }
03937 
03938     ssl->out_msg[4] = ( lifetime >> 24 ) & 0xFF;
03939     ssl->out_msg[5] = ( lifetime >> 16 ) & 0xFF;
03940     ssl->out_msg[6] = ( lifetime >>  8 ) & 0xFF;
03941     ssl->out_msg[7] = ( lifetime       ) & 0xFF;
03942 
03943     ssl->out_msg[8] = (unsigned char)( ( tlen >> 8 ) & 0xFF );
03944     ssl->out_msg[9] = (unsigned char)( ( tlen      ) & 0xFF );
03945 
03946     ssl->out_msglen = 10 + tlen;
03947 
03948     /*
03949      * Morally equivalent to updating ssl->state, but NewSessionTicket and
03950      * ChangeCipherSpec share the same state.
03951      */
03952     ssl->handshake->new_session_ticket = 0;
03953 
03954     if( ( ret = mbedtls_ssl_write_record( ssl ) ) != 0 )
03955     {
03956         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_write_record", ret );
03957         return( ret );
03958     }
03959 
03960     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write new session ticket" ) );
03961 
03962     return( 0 );
03963 }
03964 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
03965 
03966 /*
03967  * SSL handshake -- server side -- single step
03968  */
03969 int mbedtls_ssl_handshake_server_step( mbedtls_ssl_context *ssl )
03970 {
03971     int ret = 0;
03972 
03973     if( ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER || ssl->handshake == NULL )
03974         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
03975 
03976     MBEDTLS_SSL_DEBUG_MSG( 2, ( "server state: %d", ssl->state ) );
03977 
03978     if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
03979         return( ret );
03980 
03981 #if defined(MBEDTLS_SSL_PROTO_DTLS)
03982     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
03983         ssl->handshake->retransmit_state == MBEDTLS_SSL_RETRANS_SENDING )
03984     {
03985         if( ( ret = mbedtls_ssl_resend( ssl ) ) != 0 )
03986             return( ret );
03987     }
03988 #endif
03989 
03990     switch( ssl->state )
03991     {
03992         case MBEDTLS_SSL_HELLO_REQUEST:
03993             ssl->state = MBEDTLS_SSL_CLIENT_HELLO;
03994             break;
03995 
03996         /*
03997          *  <==   ClientHello
03998          */
03999         case MBEDTLS_SSL_CLIENT_HELLO:
04000             ret = ssl_parse_client_hello( ssl );
04001             break;
04002 
04003 #if defined(MBEDTLS_SSL_PROTO_DTLS)
04004         case MBEDTLS_SSL_SERVER_HELLO_VERIFY_REQUEST_SENT:
04005             return( MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED );
04006 #endif
04007 
04008         /*
04009          *  ==>   ServerHello
04010          *        Certificate
04011          *      ( ServerKeyExchange  )
04012          *      ( CertificateRequest )
04013          *        ServerHelloDone
04014          */
04015         case MBEDTLS_SSL_SERVER_HELLO:
04016             ret = ssl_write_server_hello( ssl );
04017             break;
04018 
04019         case MBEDTLS_SSL_SERVER_CERTIFICATE:
04020             ret = mbedtls_ssl_write_certificate( ssl );
04021             break;
04022 
04023         case MBEDTLS_SSL_SERVER_KEY_EXCHANGE:
04024             ret = ssl_write_server_key_exchange( ssl );
04025             break;
04026 
04027         case MBEDTLS_SSL_CERTIFICATE_REQUEST:
04028             ret = ssl_write_certificate_request( ssl );
04029             break;
04030 
04031         case MBEDTLS_SSL_SERVER_HELLO_DONE:
04032             ret = ssl_write_server_hello_done( ssl );
04033             break;
04034 
04035         /*
04036          *  <== ( Certificate/Alert  )
04037          *        ClientKeyExchange
04038          *      ( CertificateVerify  )
04039          *        ChangeCipherSpec
04040          *        Finished
04041          */
04042         case MBEDTLS_SSL_CLIENT_CERTIFICATE:
04043             ret = mbedtls_ssl_parse_certificate( ssl );
04044             break;
04045 
04046         case MBEDTLS_SSL_CLIENT_KEY_EXCHANGE:
04047             ret = ssl_parse_client_key_exchange( ssl );
04048             break;
04049 
04050         case MBEDTLS_SSL_CERTIFICATE_VERIFY:
04051             ret = ssl_parse_certificate_verify( ssl );
04052             break;
04053 
04054         case MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC:
04055             ret = mbedtls_ssl_parse_change_cipher_spec( ssl );
04056             break;
04057 
04058         case MBEDTLS_SSL_CLIENT_FINISHED:
04059             ret = mbedtls_ssl_parse_finished( ssl );
04060             break;
04061 
04062         /*
04063          *  ==> ( NewSessionTicket )
04064          *        ChangeCipherSpec
04065          *        Finished
04066          */
04067         case MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC:
04068 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
04069             if( ssl->handshake->new_session_ticket != 0 )
04070                 ret = ssl_write_new_session_ticket( ssl );
04071             else
04072 #endif
04073                 ret = mbedtls_ssl_write_change_cipher_spec( ssl );
04074             break;
04075 
04076         case MBEDTLS_SSL_SERVER_FINISHED:
04077             ret = mbedtls_ssl_write_finished( ssl );
04078             break;
04079 
04080         case MBEDTLS_SSL_FLUSH_BUFFERS:
04081             MBEDTLS_SSL_DEBUG_MSG( 2, ( "handshake: done" ) );
04082             ssl->state = MBEDTLS_SSL_HANDSHAKE_WRAPUP;
04083             break;
04084 
04085         case MBEDTLS_SSL_HANDSHAKE_WRAPUP:
04086             mbedtls_ssl_handshake_wrapup( ssl );
04087             break;
04088 
04089         default:
04090             MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) );
04091             return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
04092     }
04093 
04094     return( ret );
04095 }
04096 #endif /* MBEDTLS_SSL_SRV_C */