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) 1999-2007 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 #include <openssl/bn.h>
 125 #ifndef OPENSSL_NO_DH
 126 #include <openssl/dh.h>
 127 #endif
 128
 129 static const SSL_METHOD *dtls1_get_server_method(int ver);
 130 static int dtls1_send_hello_verify_request(SSL *s);
 131
 132 static const SSL_METHOD *dtls1_get_server_method(int ver)
 133         {
 134         if (ver == DTLS1_VERSION)
 135                 return(DTLSv1_server_method());
 136         else
 137                 return(NULL);
 138         }
 139
 140 IMPLEMENT_dtls1_meth_func(DTLSv1_server_method,
 141                         dtls1_accept,
 142                         ssl_undefined_function,
 143                         dtls1_get_server_method)
 144
 145 int dtls1_accept(SSL *s)
 146         {
 147         BUF_MEM *buf;
 148         unsigned long Time=(unsigned long)time(NULL);
 149         void (*cb)(const SSL *ssl,int type,int val)=NULL;
 150         long num1;
 151         unsigned long alg_k;
 152         int ret= -1;
 153         int new_state,state,skip=0;
 154
 155         RAND_add(&Time,sizeof(Time),0);
 156         ERR_clear_error();
 157         clear_sys_error();
 158
 159         if (s->info_callback != NULL)
 160                 cb=s->info_callback;
 161         else if (s->ctx->info_callback != NULL)
 162                 cb=s->ctx->info_callback;
 163
 164         /* init things to blank */
 165         s->in_handshake++;
 166         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
 167
 168         if (s->cert == NULL)
 169                 {
 170                 SSLerr(SSL_F_DTLS1_ACCEPT,SSL_R_NO_CERTIFICATE_SET);
 171                 return(-1);
 172                 }
 173
 174         for (;;)
 175                 {
 176                 state=s->state;
 177
 178                 switch (s->state)
 179                         {
 180                 case SSL_ST_RENEGOTIATE:
 181                         s->new_session=1;
 182                         /* s->state=SSL_ST_ACCEPT; */
 183
 184                 case SSL_ST_BEFORE:
 185                 case SSL_ST_ACCEPT:
 186                 case SSL_ST_BEFORE|SSL_ST_ACCEPT:
 187                 case SSL_ST_OK|SSL_ST_ACCEPT:
 188
 189                         s->server=1;
 190                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
 191
 192                         if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00))
 193                                 {
 194                                 SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 195                                 return -1;
 196                                 }
 197                         s->type=SSL_ST_ACCEPT;
 198
 199                         if (s->init_buf == NULL)
 200                                 {
 201                                 if ((buf=BUF_MEM_new()) == NULL)
 202                                         {
 203                                         ret= -1;
 204                                         goto end;
 205                                         }
 206                                 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
 207                                         {
 208                                         ret= -1;
 209                                         goto end;
 210                                         }
 211                                 s->init_buf=buf;
 212                                 }
 213
 214                         if (!ssl3_setup_buffers(s))
 215                                 {
 216                                 ret= -1;
 217                                 goto end;
 218                                 }
 219
 220                         s->init_num=0;
 221
 222                         if (s->state != SSL_ST_RENEGOTIATE)
 223                                 {
 224                                 /* Ok, we now need to push on a buffering BIO so that
 225                                  * the output is sent in a way that TCP likes :-)
 226                                  */
 227                                 if (!ssl_init_wbio_buffer(s,1)) { ret= -1; goto end; }
 228
 229                                 ssl3_init_finished_mac(s);
 230                                 s->state=SSL3_ST_SR_CLNT_HELLO_A;
 231                                 s->ctx->stats.sess_accept++;
 232                                 }
 233                         else
 234                                 {
 235                                 /* s->state == SSL_ST_RENEGOTIATE,
 236                                  * we will just send a HelloRequest */
 237                                 s->ctx->stats.sess_accept_renegotiate++;
 238                                 s->state=SSL3_ST_SW_HELLO_REQ_A;
 239                                 }
 240
 241                         if ( (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
 242                                 s->d1->send_cookie = 1;
 243                         else
 244                                 s->d1->send_cookie = 0;
 245
 246                         break;
 247
 248                 case SSL3_ST_SW_HELLO_REQ_A:
 249                 case SSL3_ST_SW_HELLO_REQ_B:
 250
 251                         s->shutdown=0;
 252                         dtls1_start_timer(s);
 253                         ret=dtls1_send_hello_request(s);
 254                         if (ret <= 0) goto end;
 255                         s->s3->tmp.next_state=SSL3_ST_SW_HELLO_REQ_C;
 256                         s->state=SSL3_ST_SW_FLUSH;
 257                         s->init_num=0;
 258
 259                         ssl3_init_finished_mac(s);
 260                         break;
 261
 262                 case SSL3_ST_SW_HELLO_REQ_C:
 263                         s->state=SSL_ST_OK;
 264                         break;
 265
 266                 case SSL3_ST_SR_CLNT_HELLO_A:
 267                 case SSL3_ST_SR_CLNT_HELLO_B:
 268                 case SSL3_ST_SR_CLNT_HELLO_C:
 269
 270                         s->shutdown=0;
 271                         ret=ssl3_get_client_hello(s);
 272                         if (ret <= 0) goto end;
 273                         dtls1_stop_timer(s);
 274                         s->new_session = 2;
 275
 276                         if (s->d1->send_cookie)
 277                                 s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
 278                         else
 279                                 s->state = SSL3_ST_SW_SRVR_HELLO_A;
 280
 281                         s->init_num=0;
 282                         break;
 283
 284                 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
 285                 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
 286
 287                         dtls1_start_timer(s);
 288                         ret = dtls1_send_hello_verify_request(s);
 289                         if ( ret <= 0) goto end;
 290                         s->d1->send_cookie = 0;
 291                         s->state=SSL3_ST_SW_FLUSH;
 292                         s->s3->tmp.next_state=SSL3_ST_SR_CLNT_HELLO_A;
 293
 294                         /* HelloVerifyRequest resets Finished MAC */
 295                         if (s->version != DTLS1_BAD_VER)
 296                                 ssl3_init_finished_mac(s);
 297                         break;
 298
 299                 case SSL3_ST_SW_SRVR_HELLO_A:
 300                 case SSL3_ST_SW_SRVR_HELLO_B:
 301                         dtls1_start_timer(s);
 302                         ret=dtls1_send_server_hello(s);
 303                         if (ret <= 0) goto end;
 304
 305                         if (s->hit)
 306                                 s->state=SSL3_ST_SW_CHANGE_A;
 307                         else
 308                                 s->state=SSL3_ST_SW_CERT_A;
 309                         s->init_num=0;
 310                         break;
 311
 312                 case SSL3_ST_SW_CERT_A:
 313                 case SSL3_ST_SW_CERT_B:
 314                         /* Check if it is anon DH */
 315                         if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL))
 316                                 {
 317                                 dtls1_start_timer(s);
 318                                 ret=dtls1_send_server_certificate(s);
 319                                 if (ret <= 0) goto end;
 320                                 }
 321                         else
 322                                 skip=1;
 323                         s->state=SSL3_ST_SW_KEY_EXCH_A;
 324                         s->init_num=0;
 325                         break;
 326
 327                 case SSL3_ST_SW_KEY_EXCH_A:
 328                 case SSL3_ST_SW_KEY_EXCH_B:
 329                         alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
 330
 331                         /* clear this, it may get reset by
 332                          * send_server_key_exchange */
 333                         if ((s->options & SSL_OP_EPHEMERAL_RSA)
 334 #ifndef OPENSSL_NO_KRB5
 335                                 && !(alg_k & SSL_kKRB5)
 336 #endif /* OPENSSL_NO_KRB5 */
 337                                 )
 338                                 /* option SSL_OP_EPHEMERAL_RSA sends temporary RSA key
 339                                  * even when forbidden by protocol specs
 340                                  * (handshake may fail as clients are not required to
 341                                  * be able to handle this) */
 342                                 s->s3->tmp.use_rsa_tmp=1;
 343                         else
 344                                 s->s3->tmp.use_rsa_tmp=0;
 345
 346                         /* only send if a DH key exchange or
 347                          * RSA but we have a sign only certificate */
 348                         if (s->s3->tmp.use_rsa_tmp
 349                             || (alg_k & (SSL_kEDH|SSL_kDHr|SSL_kDHd))
 350                             || ((alg_k & SSL_kRSA)
 351                                 && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
 352                                     || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
 353                                         && EVP_PKEY_size(s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey)*8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
 354                                         )
 355                                     )
 356                                 )
 357                             )
 358                                 {
 359                                 dtls1_start_timer(s);
 360                                 ret=dtls1_send_server_key_exchange(s);
 361                                 if (ret <= 0) goto end;
 362                                 }
 363                         else
 364                                 skip=1;
 365
 366                         s->state=SSL3_ST_SW_CERT_REQ_A;
 367                         s->init_num=0;
 368                         break;
 369
 370                 case SSL3_ST_SW_CERT_REQ_A:
 371                 case SSL3_ST_SW_CERT_REQ_B:
 372                         if (/* don't request cert unless asked for it: */
 373                                 !(s->verify_mode & SSL_VERIFY_PEER) ||
 374                                 /* if SSL_VERIFY_CLIENT_ONCE is set,
 375                                  * don't request cert during re-negotiation: */
 376                                 ((s->session->peer != NULL) &&
 377                                  (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
 378                                 /* never request cert in anonymous ciphersuites
 379                                  * (see section "Certificate request" in SSL 3 drafts
 380                                  * and in RFC 2246): */
 381                                 ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
 382                                  /* ... except when the application insists on verification
 383                                   * (against the specs, but s3_clnt.c accepts this for SSL 3) */
 384                                  !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
 385                                  /* never request cert in Kerberos ciphersuites */
 386                                 (s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5))
 387                                 {
 388                                 /* no cert request */
 389                                 skip=1;
 390                                 s->s3->tmp.cert_request=0;
 391                                 s->state=SSL3_ST_SW_SRVR_DONE_A;
 392                                 }
 393                         else
 394                                 {
 395                                 s->s3->tmp.cert_request=1;
 396                                 dtls1_start_timer(s);
 397                                 ret=dtls1_send_certificate_request(s);
 398                                 if (ret <= 0) goto end;
 399 #ifndef NETSCAPE_HANG_BUG
 400                                 s->state=SSL3_ST_SW_SRVR_DONE_A;
 401 #else
 402                                 s->state=SSL3_ST_SW_FLUSH;
 403                                 s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
 404 #endif
 405                                 s->init_num=0;
 406                                 }
 407                         break;
 408
 409                 case SSL3_ST_SW_SRVR_DONE_A:
 410                 case SSL3_ST_SW_SRVR_DONE_B:
 411                         dtls1_start_timer(s);
 412                         ret=dtls1_send_server_done(s);
 413                         if (ret <= 0) goto end;
 414                         s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
 415                         s->state=SSL3_ST_SW_FLUSH;
 416                         s->init_num=0;
 417                         break;
 418
 419                 case SSL3_ST_SW_FLUSH:
 420                         /* number of bytes to be flushed */
 421                         num1=BIO_ctrl(s->wbio,BIO_CTRL_INFO,0,NULL);
 422                         if (num1 > 0)
 423                                 {
 424                                 s->rwstate=SSL_WRITING;
 425                                 num1=BIO_flush(s->wbio);
 426                                 if (num1 <= 0) { ret= -1; goto end; }
 427                                 s->rwstate=SSL_NOTHING;
 428                                 }
 429
 430                         s->state=s->s3->tmp.next_state;
 431                         break;
 432
 433                 case SSL3_ST_SR_CERT_A:
 434                 case SSL3_ST_SR_CERT_B:
 435                         /* Check for second client hello (MS SGC) */
 436                         ret = ssl3_check_client_hello(s);
 437                         if (ret <= 0)
 438                                 goto end;
 439                         dtls1_stop_timer(s);
 440                         if (ret == 2)
 441                                 s->state = SSL3_ST_SR_CLNT_HELLO_C;
 442                         else {
 443                                 /* could be sent for a DH cert, even if we
 444                                  * have not asked for it :-) */
 445                                 ret=ssl3_get_client_certificate(s);
 446                                 if (ret <= 0) goto end;
 447                                 dtls1_stop_timer(s);
 448                                 s->init_num=0;
 449                                 s->state=SSL3_ST_SR_KEY_EXCH_A;
 450                         }
 451                         break;
 452
 453                 case SSL3_ST_SR_KEY_EXCH_A:
 454                 case SSL3_ST_SR_KEY_EXCH_B:
 455                         ret=ssl3_get_client_key_exchange(s);
 456                         if (ret <= 0) goto end;
 457                         dtls1_stop_timer(s);
 458                         s->state=SSL3_ST_SR_CERT_VRFY_A;
 459                         s->init_num=0;
 460
 461                         /* We need to get hashes here so if there is
 462                          * a client cert, it can be verified */
 463                         s->method->ssl3_enc->cert_verify_mac(s,
 464                                 NID_md5,
 465                                 &(s->s3->tmp.cert_verify_md[0]));
 466                         s->method->ssl3_enc->cert_verify_mac(s,
 467                                 NID_sha1,
 468                                 &(s->s3->tmp.cert_verify_md[MD5_DIGEST_LENGTH]));
 469
 470                         break;
 471
 472                 case SSL3_ST_SR_CERT_VRFY_A:
 473                 case SSL3_ST_SR_CERT_VRFY_B:
 474
 475                         /* we should decide if we expected this one */
 476                         ret=ssl3_get_cert_verify(s);
 477                         if (ret <= 0) goto end;
 478                         dtls1_stop_timer(s);
 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                         dtls1_stop_timer(s);
 490                         if (s->hit)
 491                                 s->state=SSL_ST_OK;
 492                         else
 493                                 s->state=SSL3_ST_SW_CHANGE_A;
 494                         s->init_num=0;
 495                         break;
 496
 497                 case SSL3_ST_SW_CHANGE_A:
 498                 case SSL3_ST_SW_CHANGE_B:
 499
 500                         s->session->cipher=s->s3->tmp.new_cipher;
 501                         if (!s->method->ssl3_enc->setup_key_block(s))
 502                                 { ret= -1; goto end; }
 503
 504                         ret=dtls1_send_change_cipher_spec(s,
 505                                 SSL3_ST_SW_CHANGE_A,SSL3_ST_SW_CHANGE_B);
 506
 507                         if (ret <= 0) goto end;
 508                         s->state=SSL3_ST_SW_FINISHED_A;
 509                         s->init_num=0;
 510
 511                         if (!s->method->ssl3_enc->change_cipher_state(s,
 512                                 SSL3_CHANGE_CIPHER_SERVER_WRITE))
 513                                 {
 514                                 ret= -1;
 515                                 goto end;
 516                                 }
 517
 518                         dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
 519                         break;
 520
 521                 case SSL3_ST_SW_FINISHED_A:
 522                 case SSL3_ST_SW_FINISHED_B:
 523                         ret=dtls1_send_finished(s,
 524                                 SSL3_ST_SW_FINISHED_A,SSL3_ST_SW_FINISHED_B,
 525                                 s->method->ssl3_enc->server_finished_label,
 526                                 s->method->ssl3_enc->server_finished_label_len);
 527                         if (ret <= 0) goto end;
 528                         s->state=SSL3_ST_SW_FLUSH;
 529                         if (s->hit)
 530                                 s->s3->tmp.next_state=SSL3_ST_SR_FINISHED_A;
 531                         else
 532                                 s->s3->tmp.next_state=SSL_ST_OK;
 533                         s->init_num=0;
 534                         break;
 535
 536                 case SSL_ST_OK:
 537                         /* clean a few things up */
 538                         ssl3_cleanup_key_block(s);
 539
 540 #if 0
 541                         BUF_MEM_free(s->init_buf);
 542                         s->init_buf=NULL;
 543 #endif
 544
 545                         /* remove buffering on output */
 546                         ssl_free_wbio_buffer(s);
 547
 548                         s->init_num=0;
 549
 550                         if (s->new_session == 2) /* skipped if we just sent a HelloRequest */
 551                                 {
 552                                 /* actually not necessarily a 'new' session unless
 553                                  * SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION is set */
 554
 555                                 s->new_session=0;
 556
 557                                 ssl_update_cache(s,SSL_SESS_CACHE_SERVER);
 558
 559                                 s->ctx->stats.sess_accept_good++;
 560                                 /* s->server=1; */
 561                                 s->handshake_func=dtls1_accept;
 562
 563                                 if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_DONE,1);
 564                                 }
 565
 566                         ret = 1;
 567
 568                         /* done handshaking, next message is client hello */
 569                         s->d1->handshake_read_seq = 0;
 570                         /* next message is server hello */
 571                         s->d1->handshake_write_seq = 0;
 572                         s->d1->next_handshake_write_seq = 0;
 573                         goto end;
 574                         /* break; */
 575
 576                 default:
 577                         SSLerr(SSL_F_DTLS1_ACCEPT,SSL_R_UNKNOWN_STATE);
 578                         ret= -1;
 579                         goto end;
 580                         /* break; */
 581                         }
 582
 583                 if (!s->s3->tmp.reuse_message && !skip)
 584                         {
 585                         if (s->debug)
 586                                 {
 587                                 if ((ret=BIO_flush(s->wbio)) <= 0)
 588                                         goto end;
 589                                 }
 590
 591
 592                         if ((cb != NULL) && (s->state != state))
 593                                 {
 594                                 new_state=s->state;
 595                                 s->state=state;
 596                                 cb(s,SSL_CB_ACCEPT_LOOP,1);
 597                                 s->state=new_state;
 598                                 }
 599                         }
 600                 skip=0;
 601                 }
 602 end:
 603         /* BIO_flush(s->wbio); */
 604
 605         s->in_handshake--;
 606         if (cb != NULL)
 607                 cb(s,SSL_CB_ACCEPT_EXIT,ret);
 608         return(ret);
 609         }
 610
 611 int dtls1_send_hello_request(SSL *s)
 612         {
 613         unsigned char *p;
 614
 615         if (s->state == SSL3_ST_SW_HELLO_REQ_A)
 616                 {
 617                 p=(unsigned char *)s->init_buf->data;
 618                 p = dtls1_set_message_header(s, p, SSL3_MT_HELLO_REQUEST, 0, 0, 0);
 619
 620                 s->state=SSL3_ST_SW_HELLO_REQ_B;
 621                 /* number of bytes to write */
 622                 s->init_num=DTLS1_HM_HEADER_LENGTH;
 623                 s->init_off=0;
 624
 625                 /* no need to buffer this message, since there are no retransmit
 626                  * requests for it */
 627                 }
 628
 629         /* SSL3_ST_SW_HELLO_REQ_B */
 630         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 631         }
 632
 633 int dtls1_send_hello_verify_request(SSL *s)
 634         {
 635         unsigned int msg_len;
 636         unsigned char *msg, *buf, *p;
 637
 638         if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A)
 639                 {
 640                 buf = (unsigned char *)s->init_buf->data;
 641
 642                 msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
 643                 *(p++) = s->version >> 8;
 644                 *(p++) = s->version & 0xFF;
 645
 646                 if (s->ctx->app_gen_cookie_cb != NULL &&
 647                     s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
 648                         &(s->d1->cookie_len)) == 0)
 649                         {
 650                         SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,ERR_R_INTERNAL_ERROR);
 651                         return 0;
 652                         }
 653                 /* else the cookie is assumed to have
 654                  * been initialized by the application */
 655
 656                 *(p++) = (unsigned char) s->d1->cookie_len;
 657                 memcpy(p, s->d1->cookie, s->d1->cookie_len);
 658                 p += s->d1->cookie_len;
 659                 msg_len = p - msg;
 660
 661                 dtls1_set_message_header(s, buf,
 662                         DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0, msg_len);
 663
 664                 s->state=DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
 665                 /* number of bytes to write */
 666                 s->init_num=p-buf;
 667                 s->init_off=0;
 668
 669                 /* buffer the message to handle re-xmits */
 670                 dtls1_buffer_message(s, 0);
 671                 }
 672
 673         /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
 674         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 675         }
 676
 677 int dtls1_send_server_hello(SSL *s)
 678         {
 679         unsigned char *buf;
 680         unsigned char *p,*d;
 681         int i;
 682         unsigned int sl;
 683         unsigned long l,Time;
 684
 685         if (s->state == SSL3_ST_SW_SRVR_HELLO_A)
 686                 {
 687                 buf=(unsigned char *)s->init_buf->data;
 688                 p=s->s3->server_random;
 689                 Time=(unsigned long)time(NULL);                 /* Time */
 690                 l2n(Time,p);
 691                 RAND_pseudo_bytes(p,SSL3_RANDOM_SIZE-sizeof(Time));
 692                 /* Do the message type and length last */
 693                 d=p= &(buf[DTLS1_HM_HEADER_LENGTH]);
 694
 695                 *(p++)=s->version>>8;
 696                 *(p++)=s->version&0xff;
 697
 698                 /* Random stuff */
 699                 memcpy(p,s->s3->server_random,SSL3_RANDOM_SIZE);
 700                 p+=SSL3_RANDOM_SIZE;
 701
 702                 /* now in theory we have 3 options to sending back the
 703                  * session id.  If it is a re-use, we send back the
 704                  * old session-id, if it is a new session, we send
 705                  * back the new session-id or we send back a 0 length
 706                  * session-id if we want it to be single use.
 707                  * Currently I will not implement the '0' length session-id
 708                  * 12-Jan-98 - I'll now support the '0' length stuff.
 709                  */
 710                 if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER))
 711                         s->session->session_id_length=0;
 712
 713                 sl=s->session->session_id_length;
 714                 if (sl > sizeof s->session->session_id)
 715                         {
 716                         SSLerr(SSL_F_DTLS1_SEND_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
 717                         return -1;
 718                         }
 719                 *(p++)=sl;
 720                 memcpy(p,s->session->session_id,sl);
 721                 p+=sl;
 722
 723                 /* put the cipher */
 724                 i=ssl3_put_cipher_by_char(s->s3->tmp.new_cipher,p);
 725                 p+=i;
 726
 727                 /* put the compression method */
 728 #ifdef OPENSSL_NO_COMP
 729                 *(p++)=0;
 730 #else
 731                 if (s->s3->tmp.new_compression == NULL)
 732                         *(p++)=0;
 733                 else
 734                         *(p++)=s->s3->tmp.new_compression->id;
 735 #endif
 736
 737                 /* do the header */
 738                 l=(p-d);
 739                 d=buf;
 740
 741                 d = dtls1_set_message_header(s, d, SSL3_MT_SERVER_HELLO, l, 0, l);
 742
 743                 s->state=SSL3_ST_SW_SRVR_HELLO_B;
 744                 /* number of bytes to write */
 745                 s->init_num=p-buf;
 746                 s->init_off=0;
 747
 748                 /* buffer the message to handle re-xmits */
 749                 dtls1_buffer_message(s, 0);
 750                 }
 751
 752         /* SSL3_ST_SW_SRVR_HELLO_B */
 753         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 754         }
 755
 756 int dtls1_send_server_done(SSL *s)
 757         {
 758         unsigned char *p;
 759
 760         if (s->state == SSL3_ST_SW_SRVR_DONE_A)
 761                 {
 762                 p=(unsigned char *)s->init_buf->data;
 763
 764                 /* do the header */
 765                 p = dtls1_set_message_header(s, p, SSL3_MT_SERVER_DONE, 0, 0, 0);
 766
 767                 s->state=SSL3_ST_SW_SRVR_DONE_B;
 768                 /* number of bytes to write */
 769                 s->init_num=DTLS1_HM_HEADER_LENGTH;
 770                 s->init_off=0;
 771
 772                 /* buffer the message to handle re-xmits */
 773                 dtls1_buffer_message(s, 0);
 774                 }
 775
 776         /* SSL3_ST_SW_SRVR_DONE_B */
 777         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 778         }
 779
 780 int dtls1_send_server_key_exchange(SSL *s)
 781         {
 782 #ifndef OPENSSL_NO_RSA
 783         unsigned char *q;
 784         int j,num;
 785         RSA *rsa;
 786         unsigned char md_buf[MD5_DIGEST_LENGTH+SHA_DIGEST_LENGTH];
 787         unsigned int u;
 788 #endif
 789 #ifndef OPENSSL_NO_DH
 790         DH *dh=NULL,*dhp;
 791 #endif
 792         EVP_PKEY *pkey;
 793         unsigned char *p,*d;
 794         int al,i;
 795         unsigned long type;
 796         int n;
 797         CERT *cert;
 798         BIGNUM *r[4];
 799         int nr[4],kn;
 800         BUF_MEM *buf;
 801         EVP_MD_CTX md_ctx;
 802
 803         EVP_MD_CTX_init(&md_ctx);
 804         if (s->state == SSL3_ST_SW_KEY_EXCH_A)
 805                 {
 806                 type=s->s3->tmp.new_cipher->algorithm_mkey;
 807                 cert=s->cert;
 808
 809                 buf=s->init_buf;
 810
 811                 r[0]=r[1]=r[2]=r[3]=NULL;
 812                 n=0;
 813 #ifndef OPENSSL_NO_RSA
 814                 if (type & SSL_kRSA)
 815                         {
 816                         rsa=cert->rsa_tmp;
 817                         if ((rsa == NULL) && (s->cert->rsa_tmp_cb != NULL))
 818                                 {
 819                                 rsa=s->cert->rsa_tmp_cb(s,
 820                                       SSL_C_IS_EXPORT(s->s3->tmp.new_cipher),
 821                                       SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher));
 822                                 if(rsa == NULL)
 823                                 {
 824                                         al=SSL_AD_HANDSHAKE_FAILURE;
 825                                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_ERROR_GENERATING_TMP_RSA_KEY);
 826                                         goto f_err;
 827                                 }
 828                                 RSA_up_ref(rsa);
 829                                 cert->rsa_tmp=rsa;
 830                                 }
 831                         if (rsa == NULL)
 832                                 {
 833                                 al=SSL_AD_HANDSHAKE_FAILURE;
 834                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_MISSING_TMP_RSA_KEY);
 835                                 goto f_err;
 836                                 }
 837                         r[0]=rsa->n;
 838                         r[1]=rsa->e;
 839                         s->s3->tmp.use_rsa_tmp=1;
 840                         }
 841                 else
 842 #endif
 843 #ifndef OPENSSL_NO_DH
 844                         if (type & SSL_kEDH)
 845                         {
 846                         dhp=cert->dh_tmp;
 847                         if ((dhp == NULL) && (s->cert->dh_tmp_cb != NULL))
 848                                 dhp=s->cert->dh_tmp_cb(s,
 849                                       SSL_C_IS_EXPORT(s->s3->tmp.new_cipher),
 850                                       SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher));
 851                         if (dhp == NULL)
 852                                 {
 853                                 al=SSL_AD_HANDSHAKE_FAILURE;
 854                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_MISSING_TMP_DH_KEY);
 855                                 goto f_err;
 856                                 }
 857
 858                         if (s->s3->tmp.dh != NULL)
 859                                 {
 860                                 DH_free(dh);
 861                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
 862                                 goto err;
 863                                 }
 864
 865                         if ((dh=DHparams_dup(dhp)) == NULL)
 866                                 {
 867                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_R_DH_LIB);
 868                                 goto err;
 869                                 }
 870
 871                         s->s3->tmp.dh=dh;
 872                         if ((dhp->pub_key == NULL ||
 873                              dhp->priv_key == NULL ||
 874                              (s->options & SSL_OP_SINGLE_DH_USE)))
 875                                 {
 876                                 if(!DH_generate_key(dh))
 877                                     {
 878                                     SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
 879                                            ERR_R_DH_LIB);
 880                                     goto err;
 881                                     }
 882                                 }
 883                         else
 884                                 {
 885                                 dh->pub_key=BN_dup(dhp->pub_key);
 886                                 dh->priv_key=BN_dup(dhp->priv_key);
 887                                 if ((dh->pub_key == NULL) ||
 888                                         (dh->priv_key == NULL))
 889                                         {
 890                                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_R_DH_LIB);
 891                                         goto err;
 892                                         }
 893                                 }
 894                         r[0]=dh->p;
 895                         r[1]=dh->g;
 896                         r[2]=dh->pub_key;
 897                         }
 898                 else
 899 #endif
 900                         {
 901                         al=SSL_AD_HANDSHAKE_FAILURE;
 902                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE);
 903                         goto f_err;
 904                         }
 905                 for (i=0; r[i] != NULL; i++)
 906                         {
 907                         nr[i]=BN_num_bytes(r[i]);
 908                         n+=2+nr[i];
 909                         }
 910
 911                 if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL))
 912                         {
 913                         if ((pkey=ssl_get_sign_pkey(s,s->s3->tmp.new_cipher))
 914                                 == NULL)
 915                                 {
 916                                 al=SSL_AD_DECODE_ERROR;
 917                                 goto f_err;
 918                                 }
 919                         kn=EVP_PKEY_size(pkey);
 920                         }
 921                 else
 922                         {
 923                         pkey=NULL;
 924                         kn=0;
 925                         }
 926
 927                 if (!BUF_MEM_grow_clean(buf,n+DTLS1_HM_HEADER_LENGTH+kn))
 928                         {
 929                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_LIB_BUF);
 930                         goto err;
 931                         }
 932                 d=(unsigned char *)s->init_buf->data;
 933                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 934
 935                 for (i=0; r[i] != NULL; i++)
 936                         {
 937                         s2n(nr[i],p);
 938                         BN_bn2bin(r[i],p);
 939                         p+=nr[i];
 940                         }
 941
 942                 /* not anonymous */
 943                 if (pkey != NULL)
 944                         {
 945                         /* n is the length of the params, they start at
 946                          * &(d[DTLS1_HM_HEADER_LENGTH]) and p points to the space
 947                          * at the end. */
 948 #ifndef OPENSSL_NO_RSA
 949                         if (pkey->type == EVP_PKEY_RSA)
 950                                 {
 951                                 q=md_buf;
 952                                 j=0;
 953                                 for (num=2; num > 0; num--)
 954                                         {
 955                                         EVP_DigestInit_ex(&md_ctx,(num == 2)
 956                                                 ?s->ctx->md5:s->ctx->sha1, NULL);
 957                                         EVP_DigestUpdate(&md_ctx,&(s->s3->client_random[0]),SSL3_RANDOM_SIZE);
 958                                         EVP_DigestUpdate(&md_ctx,&(s->s3->server_random[0]),SSL3_RANDOM_SIZE);
 959                                         EVP_DigestUpdate(&md_ctx,&(d[DTLS1_HM_HEADER_LENGTH]),n);
 960                                         EVP_DigestFinal_ex(&md_ctx,q,
 961                                                 (unsigned int *)&i);
 962                                         q+=i;
 963                                         j+=i;
 964                                         }
 965                                 if (RSA_sign(NID_md5_sha1, md_buf, j,
 966                                         &(p[2]), &u, pkey->pkey.rsa) <= 0)
 967                                         {
 968                                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_LIB_RSA);
 969                                         goto err;
 970                                         }
 971                                 s2n(u,p);
 972                                 n+=u+2;
 973                                 }
 974                         else
 975 #endif
 976 #if !defined(OPENSSL_NO_DSA)
 977                                 if (pkey->type == EVP_PKEY_DSA)
 978                                 {
 979                                 /* lets do DSS */
 980                                 EVP_SignInit_ex(&md_ctx,EVP_dss1(), NULL);
 981                                 EVP_SignUpdate(&md_ctx,&(s->s3->client_random[0]),SSL3_RANDOM_SIZE);
 982                                 EVP_SignUpdate(&md_ctx,&(s->s3->server_random[0]),SSL3_RANDOM_SIZE);
 983                                 EVP_SignUpdate(&md_ctx,&(d[DTLS1_HM_HEADER_LENGTH]),n);
 984                                 if (!EVP_SignFinal(&md_ctx,&(p[2]),
 985                                         (unsigned int *)&i,pkey))
 986                                         {
 987                                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_LIB_DSA);
 988                                         goto err;
 989                                         }
 990                                 s2n(i,p);
 991                                 n+=i+2;
 992                                 }
 993                         else
 994 #endif
 995                                 {
 996                                 /* Is this error check actually needed? */
 997                                 al=SSL_AD_HANDSHAKE_FAILURE;
 998                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_UNKNOWN_PKEY_TYPE);
 999                                 goto f_err;
1000                                 }
1001                         }
1002
1003                 d = dtls1_set_message_header(s, d,
1004                         SSL3_MT_SERVER_KEY_EXCHANGE, n, 0, n);
1005
1006                 /* we should now have things packed up, so lets send
1007                  * it off */
1008                 s->init_num=n+DTLS1_HM_HEADER_LENGTH;
1009                 s->init_off=0;
1010
1011                 /* buffer the message to handle re-xmits */
1012                 dtls1_buffer_message(s, 0);
1013                 }
1014
1015         s->state = SSL3_ST_SW_KEY_EXCH_B;
1016         EVP_MD_CTX_cleanup(&md_ctx);
1017         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
1018 f_err:
1019         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1020 err:
1021         EVP_MD_CTX_cleanup(&md_ctx);
1022         return(-1);
1023         }
1024
1025 int dtls1_send_certificate_request(SSL *s)
1026         {
1027         unsigned char *p,*d;
1028         int i,j,nl,off,n;
1029         STACK_OF(X509_NAME) *sk=NULL;
1030         X509_NAME *name;
1031         BUF_MEM *buf;
1032         unsigned int msg_len;
1033
1034         if (s->state == SSL3_ST_SW_CERT_REQ_A)
1035                 {
1036                 buf=s->init_buf;
1037
1038                 d=p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1039
1040                 /* get the list of acceptable cert types */
1041                 p++;
1042                 n=ssl3_get_req_cert_type(s,p);
1043                 d[0]=n;
1044                 p+=n;
1045                 n++;
1046
1047                 off=n;
1048                 p+=2;
1049                 n+=2;
1050
1051                 sk=SSL_get_client_CA_list(s);
1052                 nl=0;
1053                 if (sk != NULL)
1054                         {
1055                         for (i=0; i<sk_X509_NAME_num(sk); i++)
1056                                 {
1057                                 name=sk_X509_NAME_value(sk,i);
1058                                 j=i2d_X509_NAME(name,NULL);
1059                                 if (!BUF_MEM_grow_clean(buf,DTLS1_HM_HEADER_LENGTH+n+j+2))
1060                                         {
1061                                         SSLerr(SSL_F_DTLS1_SEND_CERTIFICATE_REQUEST,ERR_R_BUF_LIB);
1062                                         goto err;
1063                                         }
1064                                 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH+n]);
1065                                 if (!(s->options & SSL_OP_NETSCAPE_CA_DN_BUG))
1066                                         {
1067                                         s2n(j,p);
1068                                         i2d_X509_NAME(name,&p);
1069                                         n+=2+j;
1070                                         nl+=2+j;
1071                                         }
1072                                 else
1073                                         {
1074                                         d=p;
1075                                         i2d_X509_NAME(name,&p);
1076                                         j-=2; s2n(j,d); j+=2;
1077                                         n+=j;
1078                                         nl+=j;
1079                                         }
1080                                 }
1081                         }
1082                 /* else no CA names */
1083                 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH+off]);
1084                 s2n(nl,p);
1085
1086                 d=(unsigned char *)buf->data;
1087                 *(d++)=SSL3_MT_CERTIFICATE_REQUEST;
1088                 l2n3(n,d);
1089                 s2n(s->d1->handshake_write_seq,d);
1090                 s->d1->handshake_write_seq++;
1091
1092                 /* we should now have things packed up, so lets send
1093                  * it off */
1094
1095                 s->init_num=n+DTLS1_HM_HEADER_LENGTH;
1096                 s->init_off=0;
1097 #ifdef NETSCAPE_HANG_BUG
1098 /* XXX: what to do about this? */
1099                 p=(unsigned char *)s->init_buf->data + s->init_num;
1100
1101                 /* do the header */
1102                 *(p++)=SSL3_MT_SERVER_DONE;
1103                 *(p++)=0;
1104                 *(p++)=0;
1105                 *(p++)=0;
1106                 s->init_num += 4;
1107 #endif
1108
1109                 /* XDTLS:  set message header ? */
1110                 msg_len = s->init_num - DTLS1_HM_HEADER_LENGTH;
1111                 dtls1_set_message_header(s, (void *)s->init_buf->data,
1112                         SSL3_MT_CERTIFICATE_REQUEST, msg_len, 0, msg_len);
1113
1114                 /* buffer the message to handle re-xmits */
1115                 dtls1_buffer_message(s, 0);
1116
1117                 s->state = SSL3_ST_SW_CERT_REQ_B;
1118                 }
1119
1120         /* SSL3_ST_SW_CERT_REQ_B */
1121         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
1122 err:
1123         return(-1);
1124         }
1125
1126 int dtls1_send_server_certificate(SSL *s)
1127         {
1128         unsigned long l;
1129         X509 *x;
1130
1131         if (s->state == SSL3_ST_SW_CERT_A)
1132                 {
1133                 x=ssl_get_server_send_cert(s);
1134                 if (x == NULL)
1135                         {
1136                         /* VRS: allow null cert if auth == KRB5 */
1137                         if ((s->s3->tmp.new_cipher->algorithm_mkey != SSL_kKRB5) ||
1138                             (s->s3->tmp.new_cipher->algorithm_auth != SSL_aKRB5))
1139                                 {
1140                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_CERTIFICATE,ERR_R_INTERNAL_ERROR);
1141                                 return(0);
1142                                 }
1143                         }
1144
1145                 l=dtls1_output_cert_chain(s,x);
1146                 s->state=SSL3_ST_SW_CERT_B;
1147                 s->init_num=(int)l;
1148                 s->init_off=0;
1149
1150                 /* buffer the message to handle re-xmits */
1151                 dtls1_buffer_message(s, 0);
1152                 }
1153
1154         /* SSL3_ST_SW_CERT_B */
1155         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
1156         }