ssl/d1_srvr.c

   1 /* ssl/d1_srvr.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1999-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@OpenSSL.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <stdio.h>
 117 #include "ssl_locl.h"
 118 #include <openssl/buffer.h>
 119 #include <openssl/rand.h>
 120 #include <openssl/objects.h>
 121 #include <openssl/evp.h>
 122 #include <openssl/x509.h>
 123 #include <openssl/md5.h>
 124 #ifndef OPENSSL_NO_DH
 125 #include <openssl/dh.h>
 126 #endif
 127
 128 static SSL_METHOD *dtls1_get_server_method(int ver);
 129 static int dtls1_send_hello_verify_request(SSL *s);
 130
 131 static SSL_METHOD *dtls1_get_server_method(int ver)
 132         {
 133         if (ver == DTLS1_VERSION)
 134                 return(DTLSv1_server_method());
 135         else
 136                 return(NULL);
 137         }
 138
 139 SSL_METHOD *DTLSv1_server_method(void)
 140         {
 141         static int init=1;
 142         static SSL_METHOD DTLSv1_server_data;
 143
 144         if (init)
 145                 {
 146                 CRYPTO_w_lock(CRYPTO_LOCK_SSL_METHOD);
 147
 148                 if (init)
 149                         {
 150                         memcpy((char *)&DTLSv1_server_data,(char *)dtlsv1_base_method(),
 151                                 sizeof(SSL_METHOD));
 152                         DTLSv1_server_data.ssl_accept=dtls1_accept;
 153                         DTLSv1_server_data.get_ssl_method=dtls1_get_server_method;
 154                         init=0;
 155                         }
 156
 157                 CRYPTO_w_unlock(CRYPTO_LOCK_SSL_METHOD);
 158                 }
 159         return(&DTLSv1_server_data);
 160         }
 161
 162 int dtls1_accept(SSL *s)
 163         {
 164         BUF_MEM *buf;
 165         unsigned long l,Time=time(NULL);
 166         void (*cb)(const SSL *ssl,int type,int val)=NULL;
 167         long num1;
 168         int ret= -1;
 169         int new_state,state,skip=0;
 170
 171         RAND_add(&Time,sizeof(Time),0);
 172         ERR_clear_error();
 173         clear_sys_error();
 174
 175         if (s->info_callback != NULL)
 176                 cb=s->info_callback;
 177         else if (s->ctx->info_callback != NULL)
 178                 cb=s->ctx->info_callback;
 179
 180         /* init things to blank */
 181         s->in_handshake++;
 182         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
 183
 184         if (s->cert == NULL)
 185                 {
 186                 SSLerr(SSL_F_DTLS1_ACCEPT,SSL_R_NO_CERTIFICATE_SET);
 187                 return(-1);
 188                 }
 189
 190         for (;;)
 191                 {
 192                 state=s->state;
 193
 194                 switch (s->state)
 195                         {
 196                 case SSL_ST_RENEGOTIATE:
 197                         s->new_session=1;
 198                         /* s->state=SSL_ST_ACCEPT; */
 199
 200                 case SSL_ST_BEFORE:
 201                 case SSL_ST_ACCEPT:
 202                 case SSL_ST_BEFORE|SSL_ST_ACCEPT:
 203                 case SSL_ST_OK|SSL_ST_ACCEPT:
 204
 205                         s->server=1;
 206                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
 207
 208                         if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00))
 209                                 {
 210                                 SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 211                                 return -1;
 212                                 }
 213                         s->type=SSL_ST_ACCEPT;
 214
 215                         if (s->init_buf == NULL)
 216                                 {
 217                                 if ((buf=BUF_MEM_new()) == NULL)
 218                                         {
 219                                         ret= -1;
 220                                         goto end;
 221                                         }
 222                                 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
 223                                         {
 224                                         ret= -1;
 225                                         goto end;
 226                                         }
 227                                 s->init_buf=buf;
 228                                 }
 229
 230                         if (!ssl3_setup_buffers(s))
 231                                 {
 232                                 ret= -1;
 233                                 goto end;
 234                                 }
 235
 236                         s->init_num=0;
 237
 238                         if (s->state != SSL_ST_RENEGOTIATE)
 239                                 {
 240                                 /* Ok, we now need to push on a buffering BIO so that
 241                                  * the output is sent in a way that TCP likes :-)
 242                                  */
 243                                 if (!ssl_init_wbio_buffer(s,1)) { ret= -1; goto end; }
 244
 245                                 ssl3_init_finished_mac(s);
 246                                 s->state=SSL3_ST_SR_CLNT_HELLO_A;
 247                                 s->ctx->stats.sess_accept++;
 248                                 }
 249                         else
 250                                 {
 251                                 /* s->state == SSL_ST_RENEGOTIATE,
 252                                  * we will just send a HelloRequest */
 253                                 s->ctx->stats.sess_accept_renegotiate++;
 254                                 s->state=SSL3_ST_SW_HELLO_REQ_A;
 255                                 }
 256
 257             if ( (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
 258                 s->d1->send_cookie = 1;
 259             else
 260                 s->d1->send_cookie = 0;
 261
 262                         break;
 263
 264                 case SSL3_ST_SW_HELLO_REQ_A:
 265                 case SSL3_ST_SW_HELLO_REQ_B:
 266
 267                         s->shutdown=0;
 268                         ret=dtls1_send_hello_request(s);
 269                         if (ret <= 0) goto end;
 270                         s->s3->tmp.next_state=SSL3_ST_SW_HELLO_REQ_C;
 271                         s->state=SSL3_ST_SW_FLUSH;
 272                         s->init_num=0;
 273
 274                         ssl3_init_finished_mac(s);
 275                         break;
 276
 277                 case SSL3_ST_SW_HELLO_REQ_C:
 278                         s->state=SSL_ST_OK;
 279                         break;
 280
 281                 case SSL3_ST_SR_CLNT_HELLO_A:
 282                 case SSL3_ST_SR_CLNT_HELLO_B:
 283                 case SSL3_ST_SR_CLNT_HELLO_C:
 284
 285                         s->shutdown=0;
 286                         ret=ssl3_get_client_hello(s);
 287                         if (ret <= 0) goto end;
 288                         s->new_session = 2;
 289
 290                         if ( s->d1->send_cookie)
 291                                 s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
 292                         else
 293                                 s->state = SSL3_ST_SW_SRVR_HELLO_A;
 294
 295                         s->init_num=0;
 296                         break;
 297
 298                 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
 299                 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
 300
 301                         ret = dtls1_send_hello_verify_request(s);
 302                         if ( ret <= 0) goto end;
 303                         s->d1->send_cookie = 0;
 304                         s->state=SSL3_ST_SW_FLUSH;
 305                         s->s3->tmp.next_state=SSL3_ST_SR_CLNT_HELLO_A;
 306                         break;
 307
 308                 case SSL3_ST_SW_SRVR_HELLO_A:
 309                 case SSL3_ST_SW_SRVR_HELLO_B:
 310                         ret=dtls1_send_server_hello(s);
 311                         if (ret <= 0) goto end;
 312
 313                         if (s->hit)
 314                                 s->state=SSL3_ST_SW_CHANGE_A;
 315                         else
 316                                 s->state=SSL3_ST_SW_CERT_A;
 317                         s->init_num=0;
 318                         break;
 319
 320                 case SSL3_ST_SW_CERT_A:
 321                 case SSL3_ST_SW_CERT_B:
 322                         /* Check if it is anon DH */
 323                         if (!(s->s3->tmp.new_cipher->algorithms & SSL_aNULL))
 324                                 {
 325                                 ret=dtls1_send_server_certificate(s);
 326                                 if (ret <= 0) goto end;
 327                                 }
 328                         else
 329                                 skip=1;
 330                         s->state=SSL3_ST_SW_KEY_EXCH_A;
 331                         s->init_num=0;
 332                         break;
 333
 334                 case SSL3_ST_SW_KEY_EXCH_A:
 335                 case SSL3_ST_SW_KEY_EXCH_B:
 336                         l=s->s3->tmp.new_cipher->algorithms;
 337
 338                         /* clear this, it may get reset by
 339                          * send_server_key_exchange */
 340                         if ((s->options & SSL_OP_EPHEMERAL_RSA)
 341 #ifndef OPENSSL_NO_KRB5
 342                                 && !(l & SSL_KRB5)
 343 #endif /* OPENSSL_NO_KRB5 */
 344                                 )
 345                                 /* option SSL_OP_EPHEMERAL_RSA sends temporary RSA key
 346                                  * even when forbidden by protocol specs
 347                                  * (handshake may fail as clients are not required to
 348                                  * be able to handle this) */
 349                                 s->s3->tmp.use_rsa_tmp=1;
 350                         else
 351                                 s->s3->tmp.use_rsa_tmp=0;
 352
 353                         /* only send if a DH key exchange, fortezza or
 354                          * RSA but we have a sign only certificate */
 355                         if (s->s3->tmp.use_rsa_tmp
 356                             || (l & (SSL_DH|SSL_kFZA))
 357                             || ((l & SSL_kRSA)
 358                                 && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
 359                                     || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
 360                                         && EVP_PKEY_size(s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey)*8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
 361                                         )
 362                                     )
 363                                 )
 364                             )
 365                                 {
 366                                 ret=dtls1_send_server_key_exchange(s);
 367                                 if (ret <= 0) goto end;
 368                                 }
 369                         else
 370                                 skip=1;
 371
 372                         s->state=SSL3_ST_SW_CERT_REQ_A;
 373                         s->init_num=0;
 374                         break;
 375
 376                 case SSL3_ST_SW_CERT_REQ_A:
 377                 case SSL3_ST_SW_CERT_REQ_B:
 378                         if (/* don't request cert unless asked for it: */
 379                                 !(s->verify_mode & SSL_VERIFY_PEER) ||
 380                                 /* if SSL_VERIFY_CLIENT_ONCE is set,
 381                                  * don't request cert during re-negotiation: */
 382                                 ((s->session->peer != NULL) &&
 383                                  (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
 384                                 /* never request cert in anonymous ciphersuites
 385                                  * (see section "Certificate request" in SSL 3 drafts
 386                                  * and in RFC 2246): */
 387                                 ((s->s3->tmp.new_cipher->algorithms & SSL_aNULL) &&
 388                                  /* ... except when the application insists on verification
 389                                   * (against the specs, but s3_clnt.c accepts this for SSL 3) */
 390                                  !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
 391                                  /* never request cert in Kerberos ciphersuites */
 392                                 (s->s3->tmp.new_cipher->algorithms & SSL_aKRB5))
 393                                 {
 394                                 /* no cert request */
 395                                 skip=1;
 396                                 s->s3->tmp.cert_request=0;
 397                                 s->state=SSL3_ST_SW_SRVR_DONE_A;
 398                                 }
 399                         else
 400                                 {
 401                                 s->s3->tmp.cert_request=1;
 402                                 ret=dtls1_send_certificate_request(s);
 403                                 if (ret <= 0) goto end;
 404 #ifndef NETSCAPE_HANG_BUG
 405                                 s->state=SSL3_ST_SW_SRVR_DONE_A;
 406 #else
 407                                 s->state=SSL3_ST_SW_FLUSH;
 408                                 s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
 409 #endif
 410                                 s->init_num=0;
 411                                 }
 412                         break;
 413
 414                 case SSL3_ST_SW_SRVR_DONE_A:
 415                 case SSL3_ST_SW_SRVR_DONE_B:
 416                         ret=dtls1_send_server_done(s);
 417                         if (ret <= 0) goto end;
 418                         s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
 419                         s->state=SSL3_ST_SW_FLUSH;
 420                         s->init_num=0;
 421                         break;
 422
 423                 case SSL3_ST_SW_FLUSH:
 424                         /* number of bytes to be flushed */
 425                         num1=BIO_ctrl(s->wbio,BIO_CTRL_INFO,0,NULL);
 426                         if (num1 > 0)
 427                                 {
 428                                 s->rwstate=SSL_WRITING;
 429                                 num1=BIO_flush(s->wbio);
 430                                 if (num1 <= 0) { ret= -1; goto end; }
 431                                 s->rwstate=SSL_NOTHING;
 432                                 }
 433
 434                         s->state=s->s3->tmp.next_state;
 435                         break;
 436
 437                 case SSL3_ST_SR_CERT_A:
 438                 case SSL3_ST_SR_CERT_B:
 439                         /* Check for second client hello (MS SGC) */
 440                         ret = ssl3_check_client_hello(s);
 441                         if (ret <= 0)
 442                                 goto end;
 443                         if (ret == 2)
 444                                 s->state = SSL3_ST_SR_CLNT_HELLO_C;
 445                         else {
 446                                 /* could be sent for a DH cert, even if we
 447                                  * have not asked for it :-) */
 448                                 ret=ssl3_get_client_certificate(s);
 449                                 if (ret <= 0) goto end;
 450                                 s->init_num=0;
 451                                 s->state=SSL3_ST_SR_KEY_EXCH_A;
 452                         }
 453                         break;
 454
 455                 case SSL3_ST_SR_KEY_EXCH_A:
 456                 case SSL3_ST_SR_KEY_EXCH_B:
 457                         ret=ssl3_get_client_key_exchange(s);
 458                         if (ret <= 0) goto end;
 459                         s->state=SSL3_ST_SR_CERT_VRFY_A;
 460                         s->init_num=0;
 461
 462                         /* We need to get hashes here so if there is
 463                          * a client cert, it can be verified */
 464                         s->method->ssl3_enc->cert_verify_mac(s,
 465                                 &(s->s3->finish_dgst1),
 466                                 &(s->s3->tmp.cert_verify_md[0]));
 467                         s->method->ssl3_enc->cert_verify_mac(s,
 468                                 &(s->s3->finish_dgst2),
 469                                 &(s->s3->tmp.cert_verify_md[MD5_DIGEST_LENGTH]));
 470
 471                         break;
 472
 473                 case SSL3_ST_SR_CERT_VRFY_A:
 474                 case SSL3_ST_SR_CERT_VRFY_B:
 475
 476                         /* we should decide if we expected this one */
 477                         ret=ssl3_get_cert_verify(s);
 478                         if (ret <= 0) goto end;
 479
 480                         s->state=SSL3_ST_SR_FINISHED_A;
 481                         s->init_num=0;
 482                         break;
 483
 484                 case SSL3_ST_SR_FINISHED_A:
 485                 case SSL3_ST_SR_FINISHED_B:
 486                         ret=ssl3_get_finished(s,SSL3_ST_SR_FINISHED_A,
 487                                 SSL3_ST_SR_FINISHED_B);
 488                         if (ret <= 0) goto end;
 489                         if (s->hit)
 490                                 s->state=SSL_ST_OK;
 491                         else
 492                                 s->state=SSL3_ST_SW_CHANGE_A;
 493                         s->init_num=0;
 494                         break;
 495
 496                 case SSL3_ST_SW_CHANGE_A:
 497                 case SSL3_ST_SW_CHANGE_B:
 498
 499                         s->session->cipher=s->s3->tmp.new_cipher;
 500                         if (!s->method->ssl3_enc->setup_key_block(s))
 501                                 { ret= -1; goto end; }
 502
 503                         ret=dtls1_send_change_cipher_spec(s,
 504                                 SSL3_ST_SW_CHANGE_A,SSL3_ST_SW_CHANGE_B);
 505
 506                         if (ret <= 0) goto end;
 507                         s->state=SSL3_ST_SW_FINISHED_A;
 508                         s->init_num=0;
 509
 510                         if (!s->method->ssl3_enc->change_cipher_state(s,
 511                                 SSL3_CHANGE_CIPHER_SERVER_WRITE))
 512                                 {
 513                                 ret= -1;
 514                                 goto end;
 515                                 }
 516
 517                         dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
 518                         break;
 519
 520                 case SSL3_ST_SW_FINISHED_A:
 521                 case SSL3_ST_SW_FINISHED_B:
 522                         ret=dtls1_send_finished(s,
 523                                 SSL3_ST_SW_FINISHED_A,SSL3_ST_SW_FINISHED_B,
 524                                 s->method->ssl3_enc->server_finished_label,
 525                                 s->method->ssl3_enc->server_finished_label_len);
 526                         if (ret <= 0) goto end;
 527                         s->state=SSL3_ST_SW_FLUSH;
 528                         if (s->hit)
 529                                 s->s3->tmp.next_state=SSL3_ST_SR_FINISHED_A;
 530                         else
 531                                 s->s3->tmp.next_state=SSL_ST_OK;
 532                         s->init_num=0;
 533                         break;
 534
 535                 case SSL_ST_OK:
 536                         /* clean a few things up */
 537                         ssl3_cleanup_key_block(s);
 538
 539 #if 0
 540                         BUF_MEM_free(s->init_buf);
 541                         s->init_buf=NULL;
 542 #endif
 543
 544                         /* remove buffering on output */
 545                         ssl_free_wbio_buffer(s);
 546
 547                         s->init_num=0;
 548
 549                         if (s->new_session == 2) /* skipped if we just sent a HelloRequest */
 550                                 {
 551                                 /* actually not necessarily a 'new' session unless
 552                                  * SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION is set */
 553
 554                                 s->new_session=0;
 555
 556                                 ssl_update_cache(s,SSL_SESS_CACHE_SERVER);
 557
 558                                 s->ctx->stats.sess_accept_good++;
 559                                 /* s->server=1; */
 560                                 s->handshake_func=dtls1_accept;
 561
 562                                 if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_DONE,1);
 563                                 }
 564
 565                         ret = 1;
 566
 567                         /* done handshaking, next message is client hello */
 568                         s->d1->handshake_read_seq = 0;
 569                         /* next message is server hello */
 570                         s->d1->handshake_write_seq = 0;
 571                         goto end;
 572                         /* break; */
 573
 574                 default:
 575                         SSLerr(SSL_F_DTLS1_ACCEPT,SSL_R_UNKNOWN_STATE);
 576                         ret= -1;
 577                         goto end;
 578                         /* break; */
 579                         }
 580
 581                 if (!s->s3->tmp.reuse_message && !skip)
 582                         {
 583                         if (s->debug)
 584                                 {
 585                                 if ((ret=BIO_flush(s->wbio)) <= 0)
 586                                         goto end;
 587                                 }
 588
 589
 590                         if ((cb != NULL) && (s->state != state))
 591                                 {
 592                                 new_state=s->state;
 593                                 s->state=state;
 594                                 cb(s,SSL_CB_ACCEPT_LOOP,1);
 595                                 s->state=new_state;
 596                                 }
 597                         }
 598                 skip=0;
 599                 }
 600 end:
 601         /* BIO_flush(s->wbio); */
 602
 603         s->in_handshake--;
 604         if (cb != NULL)
 605                 cb(s,SSL_CB_ACCEPT_EXIT,ret);
 606         return(ret);
 607         }
 608
 609 int dtls1_send_hello_request(SSL *s)
 610         {
 611         unsigned char *p;
 612
 613         if (s->state == SSL3_ST_SW_HELLO_REQ_A)
 614                 {
 615                 p=(unsigned char *)s->init_buf->data;
 616                 p = dtls1_set_message_header(s, p, SSL3_MT_HELLO_REQUEST, 0, 0, 0);
 617
 618                 s->state=SSL3_ST_SW_HELLO_REQ_B;
 619                 /* number of bytes to write */
 620                 s->init_num=DTLS1_HM_HEADER_LENGTH;
 621                 s->init_off=0;
 622
 623                 /* no need to buffer this message, since there are no retransmit
 624                  * requests for it */
 625                 }
 626
 627         /* SSL3_ST_SW_HELLO_REQ_B */
 628         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 629         }
 630
 631 int dtls1_send_hello_verify_request(SSL *s)
 632         {
 633         unsigned int msg_len;
 634         unsigned char *msg, *buf, *p;
 635
 636         if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A)
 637                 {
 638                 buf = (unsigned char *)s->init_buf->data;
 639
 640                 msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
 641                 *(p++) = s->version >> 8;
 642                 *(p++) = s->version & 0xFF;
 643
 644                 *(p++) = (unsigned char) s->d1->cookie_len;
 645         if ( s->ctx->app_gen_cookie_cb != NULL &&
 646             s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
 647                 &(s->d1->cookie_len)) == 0)
 648             {
 649                         SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,ERR_R_INTERNAL_ERROR);
 650             return 0;
 651             }
 652         /* else the cookie is assumed to have
 653          * been initialized by the application */
 654
 655                 memcpy(p, s->d1->cookie, s->d1->cookie_len);
 656                 p += s->d1->cookie_len;
 657                 msg_len = p - msg;
 658
 659                 dtls1_set_message_header(s, buf,
 660                         DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0, msg_len);
 661
 662                 s->state=DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
 663                 /* number of bytes to write */
 664                 s->init_num=p-buf;
 665                 s->init_off=0;
 666
 667                 /* buffer the message to handle re-xmits */
 668                 dtls1_buffer_message(s, 0);
 669                 }
 670
 671         /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
 672         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 673         }
 674
 675 int dtls1_send_server_hello(SSL *s)
 676         {
 677         unsigned char *buf;
 678         unsigned char *p,*d;
 679         int i,sl;
 680         unsigned long l,Time;
 681
 682         if (s->state == SSL3_ST_SW_SRVR_HELLO_A)
 683                 {
 684                 buf=(unsigned char *)s->init_buf->data;
 685                 p=s->s3->server_random;
 686                 Time=time(NULL);                        /* Time */
 687                 l2n(Time,p);
 688                 RAND_pseudo_bytes(p,SSL3_RANDOM_SIZE-sizeof(Time));
 689                 /* Do the message type and length last */
 690                 d=p= &(buf[DTLS1_HM_HEADER_LENGTH]);
 691
 692                 *(p++)=s->version>>8;
 693                 *(p++)=s->version&0xff;
 694
 695                 /* Random stuff */
 696                 memcpy(p,s->s3->server_random,SSL3_RANDOM_SIZE);
 697                 p+=SSL3_RANDOM_SIZE;
 698
 699                 /* now in theory we have 3 options to sending back the
 700                  * session id.  If it is a re-use, we send back the
 701                  * old session-id, if it is a new session, we send
 702                  * back the new session-id or we send back a 0 length
 703                  * session-id if we want it to be single use.
 704                  * Currently I will not implement the '0' length session-id
 705                  * 12-Jan-98 - I'll now support the '0' length stuff.
 706                  */
 707                 if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER))
 708                         s->session->session_id_length=0;
 709
 710                 sl=s->session->session_id_length;
 711                 if (sl > sizeof s->session->session_id)
 712                         {
 713                         SSLerr(SSL_F_DTLS1_SEND_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
 714                         return -1;
 715                         }
 716                 *(p++)=sl;
 717                 memcpy(p,s->session->session_id,sl);
 718                 p+=sl;
 719
 720                 /* put the cipher */
 721                 i=ssl3_put_cipher_by_char(s->s3->tmp.new_cipher,p);
 722                 p+=i;
 723
 724                 /* put the compression method */
 725                 if (s->s3->tmp.new_compression == NULL)
 726                         *(p++)=0;
 727                 else
 728                         *(p++)=s->s3->tmp.new_compression->id;
 729
 730                 /* do the header */
 731                 l=(p-d);
 732                 d=buf;
 733
 734                 d = dtls1_set_message_header(s, d, SSL3_MT_SERVER_HELLO, l, 0, l);
 735
 736                 s->state=SSL3_ST_CW_CLNT_HELLO_B;
 737                 /* number of bytes to write */
 738                 s->init_num=p-buf;
 739                 s->init_off=0;
 740
 741                 /* buffer the message to handle re-xmits */
 742                 dtls1_buffer_message(s, 0);
 743                 }
 744
 745         /* SSL3_ST_CW_CLNT_HELLO_B */
 746         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 747         }
 748
 749 int dtls1_send_server_done(SSL *s)
 750         {
 751         unsigned char *p;
 752
 753         if (s->state == SSL3_ST_SW_SRVR_DONE_A)
 754                 {
 755                 p=(unsigned char *)s->init_buf->data;
 756
 757                 /* do the header */
 758                 p = dtls1_set_message_header(s, p, SSL3_MT_SERVER_DONE, 0, 0, 0);
 759
 760                 s->state=SSL3_ST_SW_SRVR_DONE_B;
 761                 /* number of bytes to write */
 762                 s->init_num=DTLS1_HM_HEADER_LENGTH;
 763                 s->init_off=0;
 764
 765                 /* buffer the message to handle re-xmits */
 766                 dtls1_buffer_message(s, 0);
 767                 }
 768
 769         /* SSL3_ST_CW_CLNT_HELLO_B */
 770         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 771         }
 772
 773 int dtls1_send_server_key_exchange(SSL *s)
 774         {
 775 #ifndef OPENSSL_NO_RSA
 776         unsigned char *q;
 777         int j,num;
 778         RSA *rsa;
 779         unsigned char md_buf[MD5_DIGEST_LENGTH+SHA_DIGEST_LENGTH];
 780         unsigned int u;
 781 #endif
 782 #ifndef OPENSSL_NO_DH
 783         DH *dh=NULL,*dhp;
 784 #endif
 785         EVP_PKEY *pkey;
 786         unsigned char *p,*d;
 787         int al,i;
 788         unsigned long type;
 789         int n;
 790         CERT *cert;
 791         BIGNUM *r[4];
 792         int nr[4],kn;
 793         BUF_MEM *buf;
 794         EVP_MD_CTX md_ctx;
 795
 796         EVP_MD_CTX_init(&md_ctx);
 797         if (s->state == SSL3_ST_SW_KEY_EXCH_A)
 798                 {
 799                 type=s->s3->tmp.new_cipher->algorithms & SSL_MKEY_MASK;
 800                 cert=s->cert;
 801
 802                 buf=s->init_buf;
 803
 804                 r[0]=r[1]=r[2]=r[3]=NULL;
 805                 n=0;
 806 #ifndef OPENSSL_NO_RSA
 807                 if (type & SSL_kRSA)
 808                         {
 809                         rsa=cert->rsa_tmp;
 810                         if ((rsa == NULL) && (s->cert->rsa_tmp_cb != NULL))
 811                                 {
 812                                 rsa=s->cert->rsa_tmp_cb(s,
 813                                       SSL_C_IS_EXPORT(s->s3->tmp.new_cipher),
 814                                       SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher));
 815                                 if(rsa == NULL)
 816                                 {
 817                                         al=SSL_AD_HANDSHAKE_FAILURE;
 818                                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_ERROR_GENERATING_TMP_RSA_KEY);
 819                                         goto f_err;
 820                                 }
 821                                 RSA_up_ref(rsa);
 822                                 cert->rsa_tmp=rsa;
 823                                 }
 824                         if (rsa == NULL)
 825                                 {
 826                                 al=SSL_AD_HANDSHAKE_FAILURE;
 827                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_MISSING_TMP_RSA_KEY);
 828                                 goto f_err;
 829                                 }
 830                         r[0]=rsa->n;
 831                         r[1]=rsa->e;
 832                         s->s3->tmp.use_rsa_tmp=1;
 833                         }
 834                 else
 835 #endif
 836 #ifndef OPENSSL_NO_DH
 837                         if (type & SSL_kEDH)
 838                         {
 839                         dhp=cert->dh_tmp;
 840                         if ((dhp == NULL) && (s->cert->dh_tmp_cb != NULL))
 841                                 dhp=s->cert->dh_tmp_cb(s,
 842                                       SSL_C_IS_EXPORT(s->s3->tmp.new_cipher),
 843                                       SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher));
 844                         if (dhp == NULL)
 845                                 {
 846                                 al=SSL_AD_HANDSHAKE_FAILURE;
 847                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_MISSING_TMP_DH_KEY);
 848                                 goto f_err;
 849                                 }
 850
 851                         if (s->s3->tmp.dh != NULL)
 852                                 {
 853                                 DH_free(dh);
 854                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
 855                                 goto err;
 856                                 }
 857
 858                         if ((dh=DHparams_dup(dhp)) == NULL)
 859                                 {
 860                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_R_DH_LIB);
 861                                 goto err;
 862                                 }
 863
 864                         s->s3->tmp.dh=dh;
 865                         if ((dhp->pub_key == NULL ||
 866                              dhp->priv_key == NULL ||
 867                              (s->options & SSL_OP_SINGLE_DH_USE)))
 868                                 {
 869                                 if(!DH_generate_key(dh))
 870                                     {
 871                                     SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
 872                                            ERR_R_DH_LIB);
 873                                     goto err;
 874                                     }
 875                                 }
 876                         else
 877                                 {
 878                                 dh->pub_key=BN_dup(dhp->pub_key);
 879                                 dh->priv_key=BN_dup(dhp->priv_key);
 880                                 if ((dh->pub_key == NULL) ||
 881                                         (dh->priv_key == NULL))
 882                                         {
 883                                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_R_DH_LIB);
 884                                         goto err;
 885                                         }
 886                                 }
 887                         r[0]=dh->p;
 888                         r[1]=dh->g;
 889                         r[2]=dh->pub_key;
 890                         }
 891                 else
 892 #endif
 893                         {
 894                         al=SSL_AD_HANDSHAKE_FAILURE;
 895                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE);
 896                         goto f_err;
 897                         }
 898                 for (i=0; r[i] != NULL; i++)
 899                         {
 900                         nr[i]=BN_num_bytes(r[i]);
 901                         n+=2+nr[i];
 902                         }
 903
 904                 if (!(s->s3->tmp.new_cipher->algorithms & SSL_aNULL))
 905                         {
 906                         if ((pkey=ssl_get_sign_pkey(s,s->s3->tmp.new_cipher))
 907                                 == NULL)
 908                                 {
 909                                 al=SSL_AD_DECODE_ERROR;
 910                                 goto f_err;
 911                                 }
 912                         kn=EVP_PKEY_size(pkey);
 913                         }
 914                 else
 915                         {
 916                         pkey=NULL;
 917                         kn=0;
 918                         }
 919
 920                 if (!BUF_MEM_grow_clean(buf,n+DTLS1_HM_HEADER_LENGTH+kn))
 921                         {
 922                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_LIB_BUF);
 923                         goto err;
 924                         }
 925                 d=(unsigned char *)s->init_buf->data;
 926                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 927
 928                 for (i=0; r[i] != NULL; i++)
 929                         {
 930                         s2n(nr[i],p);
 931                         BN_bn2bin(r[i],p);
 932                         p+=nr[i];
 933                         }
 934
 935                 /* not anonymous */
 936                 if (pkey != NULL)
 937                         {
 938                         /* n is the length of the params, they start at
 939                          * &(d[DTLS1_HM_HEADER_LENGTH]) and p points to the space
 940                          * at the end. */
 941 #ifndef OPENSSL_NO_RSA
 942                         if (pkey->type == EVP_PKEY_RSA)
 943                                 {
 944                                 q=md_buf;
 945                                 j=0;
 946                                 for (num=2; num > 0; num--)
 947                                         {
 948                                         EVP_DigestInit_ex(&md_ctx,(num == 2)
 949                                                 ?s->ctx->md5:s->ctx->sha1, NULL);
 950                                         EVP_DigestUpdate(&md_ctx,&(s->s3->client_random[0]),SSL3_RANDOM_SIZE);
 951                                         EVP_DigestUpdate(&md_ctx,&(s->s3->server_random[0]),SSL3_RANDOM_SIZE);
 952                                         EVP_DigestUpdate(&md_ctx,&(d[DTLS1_HM_HEADER_LENGTH]),n);
 953                                         EVP_DigestFinal_ex(&md_ctx,q,
 954                                                 (unsigned int *)&i);
 955                                         q+=i;
 956                                         j+=i;
 957                                         }
 958                                 if (RSA_sign(NID_md5_sha1, md_buf, j,
 959                                         &(p[2]), &u, pkey->pkey.rsa) <= 0)
 960                                         {
 961                                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_LIB_RSA);
 962                                         goto err;
 963                                         }
 964                                 s2n(u,p);
 965                                 n+=u+2;
 966                                 }
 967                         else
 968 #endif
 969 #if !defined(OPENSSL_NO_DSA)
 970                                 if (pkey->type == EVP_PKEY_DSA)
 971                                 {
 972                                 /* lets do DSS */
 973                                 EVP_SignInit_ex(&md_ctx,EVP_dss1(), NULL);
 974                                 EVP_SignUpdate(&md_ctx,&(s->s3->client_random[0]),SSL3_RANDOM_SIZE);
 975                                 EVP_SignUpdate(&md_ctx,&(s->s3->server_random[0]),SSL3_RANDOM_SIZE);
 976                                 EVP_SignUpdate(&md_ctx,&(d[DTLS1_HM_HEADER_LENGTH]),n);
 977                                 if (!EVP_SignFinal(&md_ctx,&(p[2]),
 978                                         (unsigned int *)&i,pkey))
 979                                         {
 980                                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_LIB_DSA);
 981                                         goto err;
 982                                         }
 983                                 s2n(i,p);
 984                                 n+=i+2;
 985                                 }
 986                         else
 987 #endif
 988                                 {
 989                                 /* Is this error check actually needed? */
 990                                 al=SSL_AD_HANDSHAKE_FAILURE;
 991                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_UNKNOWN_PKEY_TYPE);
 992                                 goto f_err;
 993                                 }
 994                         }
 995
 996                 d = dtls1_set_message_header(s, d,
 997                         SSL3_MT_SERVER_KEY_EXCHANGE, n, 0, n);
 998
 999                 /* we should now have things packed up, so lets send
1000                  * it off */
1001                 s->init_num=n+DTLS1_HM_HEADER_LENGTH;
1002                 s->init_off=0;
1003
1004                 /* buffer the message to handle re-xmits */
1005                 dtls1_buffer_message(s, 0);
1006                 }
1007
1008         s->state = SSL3_ST_SW_KEY_EXCH_B;
1009         EVP_MD_CTX_cleanup(&md_ctx);
1010         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
1011 f_err:
1012         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1013 err:
1014         EVP_MD_CTX_cleanup(&md_ctx);
1015         return(-1);
1016         }
1017
1018 int dtls1_send_certificate_request(SSL *s)
1019         {
1020         unsigned char *p,*d;
1021         int i,j,nl,off,n;
1022         STACK_OF(X509_NAME) *sk=NULL;
1023         X509_NAME *name;
1024         BUF_MEM *buf;
1025
1026         if (s->state == SSL3_ST_SW_CERT_REQ_A)
1027                 {
1028                 buf=s->init_buf;
1029
1030                 d=p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1031
1032                 /* get the list of acceptable cert types */
1033                 p++;
1034                 n=ssl3_get_req_cert_type(s,p);
1035                 d[0]=n;
1036                 p+=n;
1037                 n++;
1038
1039                 off=n;
1040                 p+=2;
1041                 n+=2;
1042
1043                 sk=SSL_get_client_CA_list(s);
1044                 nl=0;
1045                 if (sk != NULL)
1046                         {
1047                         for (i=0; i<sk_X509_NAME_num(sk); i++)
1048                                 {
1049                                 name=sk_X509_NAME_value(sk,i);
1050                                 j=i2d_X509_NAME(name,NULL);
1051                                 if (!BUF_MEM_grow_clean(buf,DTLS1_HM_HEADER_LENGTH+n+j+2))
1052                                         {
1053                                         SSLerr(SSL_F_DTLS1_SEND_CERTIFICATE_REQUEST,ERR_R_BUF_LIB);
1054                                         goto err;
1055                                         }
1056                                 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH+n]);
1057                                 if (!(s->options & SSL_OP_NETSCAPE_CA_DN_BUG))
1058                                         {
1059                                         s2n(j,p);
1060                                         i2d_X509_NAME(name,&p);
1061                                         n+=2+j;
1062                                         nl+=2+j;
1063                                         }
1064                                 else
1065                                         {
1066                                         d=p;
1067                                         i2d_X509_NAME(name,&p);
1068                                         j-=2; s2n(j,d); j+=2;
1069                                         n+=j;
1070                                         nl+=j;
1071                                         }
1072                                 }
1073                         }
1074                 /* else no CA names */
1075                 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH+off]);
1076                 s2n(nl,p);
1077
1078                 d=(unsigned char *)buf->data;
1079                 *(d++)=SSL3_MT_CERTIFICATE_REQUEST;
1080                 l2n3(n,d);
1081                 s2n(s->d1->handshake_write_seq,d);
1082                 s->d1->handshake_write_seq++;
1083
1084                 /* we should now have things packed up, so lets send
1085                  * it off */
1086
1087                 s->init_num=n+DTLS1_HM_HEADER_LENGTH;
1088                 s->init_off=0;
1089 #ifdef NETSCAPE_HANG_BUG
1090 /* XXX: what to do about this? */
1091                 p=(unsigned char *)s->init_buf->data + s->init_num;
1092
1093                 /* do the header */
1094                 *(p++)=SSL3_MT_SERVER_DONE;
1095                 *(p++)=0;
1096                 *(p++)=0;
1097                 *(p++)=0;
1098                 s->init_num += 4;
1099 #endif
1100
1101                 /* XDTLS:  set message header ? */
1102                 /* buffer the message to handle re-xmits */
1103                 dtls1_buffer_message(s, 0);
1104
1105                 s->state = SSL3_ST_SW_CERT_REQ_B;
1106                 }
1107
1108         /* SSL3_ST_SW_CERT_REQ_B */
1109         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
1110 err:
1111         return(-1);
1112         }
1113
1114 int dtls1_send_server_certificate(SSL *s)
1115         {
1116         unsigned long l;
1117         X509 *x;
1118
1119         if (s->state == SSL3_ST_SW_CERT_A)
1120                 {
1121                 x=ssl_get_server_send_cert(s);
1122                 if (x == NULL &&
1123                         /* VRS: allow null cert if auth == KRB5 */
1124                         (s->s3->tmp.new_cipher->algorithms
1125                                 & (SSL_MKEY_MASK|SSL_AUTH_MASK))
1126                         != (SSL_aKRB5|SSL_kKRB5))
1127                         {
1128                         SSLerr(SSL_F_DTLS1_SEND_SERVER_CERTIFICATE,ERR_R_INTERNAL_ERROR);
1129                         return(0);
1130                         }
1131
1132                 l=dtls1_output_cert_chain(s,x);
1133                 s->state=SSL3_ST_SW_CERT_B;
1134                 s->init_num=(int)l;
1135                 s->init_off=0;
1136
1137                 /* buffer the message to handle re-xmits */
1138                 dtls1_buffer_message(s, 0);
1139                 }
1140
1141         /* SSL3_ST_SW_CERT_B */
1142         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
1143         }