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 if (ver == DTLS1_2_VERSION)
 137                 return(DTLSv1_2_server_method());
 138         else
 139                 return(NULL);
 140         }
 141
 142 IMPLEMENT_dtls1_meth_func(DTLS1_VERSION,
 143                         DTLSv1_server_method,
 144                         dtls1_accept,
 145                         ssl_undefined_function,
 146                         dtls1_get_server_method,
 147                         DTLSv1_enc_data)
 148
 149 IMPLEMENT_dtls1_meth_func(DTLS1_2_VERSION,
 150                         DTLSv1_2_server_method,
 151                         dtls1_accept,
 152                         ssl_undefined_function,
 153                         dtls1_get_server_method,
 154                         DTLSv1_2_enc_data)
 155
 156 IMPLEMENT_dtls1_meth_func(DTLS_ANY_VERSION,
 157                         DTLS_server_method,
 158                         dtls1_accept,
 159                         ssl_undefined_function,
 160                         dtls1_get_server_method,
 161                         DTLSv1_2_enc_data)
 162
 163 int dtls1_accept(SSL *s)
 164         {
 165         BUF_MEM *buf;
 166         unsigned long Time=(unsigned long)time(NULL);
 167         void (*cb)(const SSL *ssl,int type,int val)=NULL;
 168         unsigned long alg_k;
 169         int ret= -1;
 170         int new_state,state,skip=0;
 171         int listen;
 172 #ifndef OPENSSL_NO_SCTP
 173         unsigned char sctpauthkey[64];
 174         char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
 175 #endif
 176
 177         RAND_add(&Time,sizeof(Time),0);
 178         ERR_clear_error();
 179         clear_sys_error();
 180
 181         if (s->info_callback != NULL)
 182                 cb=s->info_callback;
 183         else if (s->ctx->info_callback != NULL)
 184                 cb=s->ctx->info_callback;
 185
 186         listen = s->d1->listen;
 187
 188         /* init things to blank */
 189         s->in_handshake++;
 190         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
 191
 192         s->d1->listen = listen;
 193 #ifndef OPENSSL_NO_SCTP
 194         /* Notify SCTP BIO socket to enter handshake
 195          * mode and prevent stream identifier other
 196          * than 0. Will be ignored if no SCTP is used.
 197          */
 198         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE, s->in_handshake, NULL);
 199 #endif
 200
 201         if (s->cert == NULL)
 202                 {
 203                 SSLerr(SSL_F_DTLS1_ACCEPT,SSL_R_NO_CERTIFICATE_SET);
 204                 return(-1);
 205                 }
 206
 207 #ifndef OPENSSL_NO_HEARTBEATS
 208         /* If we're awaiting a HeartbeatResponse, pretend we
 209          * already got and don't await it anymore, because
 210          * Heartbeats don't make sense during handshakes anyway.
 211          */
 212         if (s->tlsext_hb_pending)
 213                 {
 214                 dtls1_stop_timer(s);
 215                 s->tlsext_hb_pending = 0;
 216                 s->tlsext_hb_seq++;
 217                 }
 218 #endif
 219
 220         for (;;)
 221                 {
 222                 state=s->state;
 223
 224                 switch (s->state)
 225                         {
 226                 case SSL_ST_RENEGOTIATE:
 227                         s->renegotiate=1;
 228                         /* s->state=SSL_ST_ACCEPT; */
 229
 230                 case SSL_ST_BEFORE:
 231                 case SSL_ST_ACCEPT:
 232                 case SSL_ST_BEFORE|SSL_ST_ACCEPT:
 233                 case SSL_ST_OK|SSL_ST_ACCEPT:
 234
 235                         s->server=1;
 236                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
 237
 238                         if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00))
 239                                 {
 240                                 SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 241                                 return -1;
 242                                 }
 243                         s->type=SSL_ST_ACCEPT;
 244
 245                         if (s->init_buf == NULL)
 246                                 {
 247                                 if ((buf=BUF_MEM_new()) == NULL)
 248                                         {
 249                                         ret= -1;
 250                                         goto end;
 251                                         }
 252                                 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
 253                                         {
 254                                         BUF_MEM_free(buf);
 255                                         ret= -1;
 256                                         goto end;
 257                                         }
 258                                 s->init_buf=buf;
 259                                 }
 260
 261                         if (!ssl3_setup_buffers(s))
 262                                 {
 263                                 ret= -1;
 264                                 goto end;
 265                                 }
 266
 267                         s->init_num=0;
 268                         s->d1->change_cipher_spec_ok = 0;
 269                         /* Should have been reset by ssl3_get_finished, too. */
 270                         s->s3->change_cipher_spec = 0;
 271
 272                         if (s->state != SSL_ST_RENEGOTIATE)
 273                                 {
 274                                 /* Ok, we now need to push on a buffering BIO so that
 275                                  * the output is sent in a way that TCP likes :-)
 276                                  * ...but not with SCTP :-)
 277                                  */
 278 #ifndef OPENSSL_NO_SCTP
 279                                 if (!BIO_dgram_is_sctp(SSL_get_wbio(s)))
 280 #endif
 281                                         if (!ssl_init_wbio_buffer(s,1)) { ret= -1; goto end; }
 282
 283                                 ssl3_init_finished_mac(s);
 284                                 s->state=SSL3_ST_SR_CLNT_HELLO_A;
 285                                 s->ctx->stats.sess_accept++;
 286                                 }
 287                         else
 288                                 {
 289                                 /* s->state == SSL_ST_RENEGOTIATE,
 290                                  * we will just send a HelloRequest */
 291                                 s->ctx->stats.sess_accept_renegotiate++;
 292                                 s->state=SSL3_ST_SW_HELLO_REQ_A;
 293                                 }
 294
 295                         break;
 296
 297                 case SSL3_ST_SW_HELLO_REQ_A:
 298                 case SSL3_ST_SW_HELLO_REQ_B:
 299
 300                         s->shutdown=0;
 301                         dtls1_clear_record_buffer(s);
 302                         dtls1_start_timer(s);
 303                         ret=ssl3_send_hello_request(s);
 304                         if (ret <= 0) goto end;
 305                         s->s3->tmp.next_state=SSL3_ST_SR_CLNT_HELLO_A;
 306                         s->state=SSL3_ST_SW_FLUSH;
 307                         s->init_num=0;
 308
 309                         ssl3_init_finished_mac(s);
 310                         break;
 311
 312                 case SSL3_ST_SW_HELLO_REQ_C:
 313                         s->state=SSL_ST_OK;
 314                         break;
 315
 316                 case SSL3_ST_SR_CLNT_HELLO_A:
 317                 case SSL3_ST_SR_CLNT_HELLO_B:
 318                 case SSL3_ST_SR_CLNT_HELLO_C:
 319
 320                         s->shutdown=0;
 321                         ret=ssl3_get_client_hello(s);
 322                         if (ret <= 0) goto end;
 323                         dtls1_stop_timer(s);
 324
 325                         if (ret == 1 && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
 326                                 s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
 327                         else
 328                                 s->state = SSL3_ST_SW_SRVR_HELLO_A;
 329
 330                         s->init_num=0;
 331
 332                         /* Reflect ClientHello sequence to remain stateless while listening */
 333                         if (listen)
 334                                 {
 335                                 memcpy(s->s3->write_sequence, s->s3->read_sequence, sizeof(s->s3->write_sequence));
 336                                 }
 337
 338                         /* If we're just listening, stop here */
 339                         if (listen && s->state == SSL3_ST_SW_SRVR_HELLO_A)
 340                                 {
 341                                 ret = 2;
 342                                 s->d1->listen = 0;
 343                                 /* Set expected sequence numbers
 344                                  * to continue the handshake.
 345                                  */
 346                                 s->d1->handshake_read_seq = 2;
 347                                 s->d1->handshake_write_seq = 1;
 348                                 s->d1->next_handshake_write_seq = 1;
 349                                 goto end;
 350                                 }
 351
 352                         break;
 353
 354                 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
 355                 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
 356
 357                         ret = dtls1_send_hello_verify_request(s);
 358                         if ( ret <= 0) goto end;
 359                         s->state=SSL3_ST_SW_FLUSH;
 360                         s->s3->tmp.next_state=SSL3_ST_SR_CLNT_HELLO_A;
 361
 362                         /* HelloVerifyRequest resets Finished MAC */
 363                         if (s->version != DTLS1_BAD_VER)
 364                                 ssl3_init_finished_mac(s);
 365                         break;
 366
 367 #ifndef OPENSSL_NO_SCTP
 368                 case DTLS1_SCTP_ST_SR_READ_SOCK:
 369
 370                         if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
 371                                 {
 372                                 s->s3->in_read_app_data=2;
 373                                 s->rwstate=SSL_READING;
 374                                 BIO_clear_retry_flags(SSL_get_rbio(s));
 375                                 BIO_set_retry_read(SSL_get_rbio(s));
 376                                 ret = -1;
 377                                 goto end;
 378                                 }
 379
 380                         s->state=SSL3_ST_SR_FINISHED_A;
 381                         break;
 382
 383                 case DTLS1_SCTP_ST_SW_WRITE_SOCK:
 384                         ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
 385                         if (ret < 0) goto end;
 386
 387                         if (ret == 0)
 388                                 {
 389                                 if (s->d1->next_state != SSL_ST_OK)
 390                                         {
 391                                         s->s3->in_read_app_data=2;
 392                                         s->rwstate=SSL_READING;
 393                                         BIO_clear_retry_flags(SSL_get_rbio(s));
 394                                         BIO_set_retry_read(SSL_get_rbio(s));
 395                                         ret = -1;
 396                                         goto end;
 397                                         }
 398                                 }
 399
 400                         s->state=s->d1->next_state;
 401                         break;
 402 #endif
 403
 404                 case SSL3_ST_SW_SRVR_HELLO_A:
 405                 case SSL3_ST_SW_SRVR_HELLO_B:
 406                         s->renegotiate = 2;
 407                         dtls1_start_timer(s);
 408                         ret=ssl3_send_server_hello(s);
 409                         if (ret <= 0) goto end;
 410
 411                         if (s->hit)
 412                                 {
 413 #ifndef OPENSSL_NO_SCTP
 414                                 /* Add new shared key for SCTP-Auth,
 415                                  * will be ignored if no SCTP used.
 416                                  */
 417                                 snprintf((char*) labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 418                                          DTLS1_SCTP_AUTH_LABEL);
 419
 420                                 SSL_export_keying_material(s, sctpauthkey,
 421                                                            sizeof(sctpauthkey), labelbuffer,
 422                                                            sizeof(labelbuffer), NULL, 0, 0);
 423
 424                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 425                          sizeof(sctpauthkey), sctpauthkey);
 426 #endif
 427 #ifndef OPENSSL_NO_TLSEXT
 428                                 if (s->tlsext_ticket_expected)
 429                                         s->state=SSL3_ST_SW_SESSION_TICKET_A;
 430                                 else
 431                                         s->state=SSL3_ST_SW_CHANGE_A;
 432 #else
 433                                 s->state=SSL3_ST_SW_CHANGE_A;
 434 #endif
 435                                 }
 436                         else
 437                                 s->state=SSL3_ST_SW_CERT_A;
 438                         s->init_num=0;
 439                         break;
 440
 441                 case SSL3_ST_SW_CERT_A:
 442                 case SSL3_ST_SW_CERT_B:
 443                         /* Check if it is anon DH or normal PSK */
 444                         if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
 445                                 && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK))
 446                                 {
 447                                 dtls1_start_timer(s);
 448                                 ret=ssl3_send_server_certificate(s);
 449                                 if (ret <= 0) goto end;
 450 #ifndef OPENSSL_NO_TLSEXT
 451                                 if (s->tlsext_status_expected)
 452                                         s->state=SSL3_ST_SW_CERT_STATUS_A;
 453                                 else
 454                                         s->state=SSL3_ST_SW_KEY_EXCH_A;
 455                                 }
 456                         else
 457                                 {
 458                                 skip = 1;
 459                                 s->state=SSL3_ST_SW_KEY_EXCH_A;
 460                                 }
 461 #else
 462                                 }
 463                         else
 464                                 skip=1;
 465
 466                         s->state=SSL3_ST_SW_KEY_EXCH_A;
 467 #endif
 468                         s->init_num=0;
 469                         break;
 470
 471                 case SSL3_ST_SW_KEY_EXCH_A:
 472                 case SSL3_ST_SW_KEY_EXCH_B:
 473                         alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
 474
 475                         /*
 476                          * clear this, it may get reset by
 477                          * send_server_key_exchange
 478                          */
 479                         s->s3->tmp.use_rsa_tmp=0;
 480
 481                         /* only send if a DH key exchange or
 482                          * RSA but we have a sign only certificate */
 483                         if (0
 484                         /* PSK: send ServerKeyExchange if PSK identity
 485                          * hint if provided */
 486 #ifndef OPENSSL_NO_PSK
 487                             || ((alg_k & SSL_kPSK) && s->ctx->psk_identity_hint)
 488 #endif
 489                             || (alg_k & (SSL_kDHE|SSL_kDHr|SSL_kDHd))
 490                             || (alg_k & SSL_kECDHE)
 491                             || ((alg_k & SSL_kRSA)
 492                                 && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
 493                                     || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
 494                                         && EVP_PKEY_size(s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey)*8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
 495                                         )
 496                                     )
 497                                 )
 498                             )
 499                                 {
 500                                 dtls1_start_timer(s);
 501                                 ret=ssl3_send_server_key_exchange(s);
 502                                 if (ret <= 0) goto end;
 503                                 }
 504                         else
 505                                 skip=1;
 506
 507                         s->state=SSL3_ST_SW_CERT_REQ_A;
 508                         s->init_num=0;
 509                         break;
 510
 511                 case SSL3_ST_SW_CERT_REQ_A:
 512                 case SSL3_ST_SW_CERT_REQ_B:
 513                         if (/* don't request cert unless asked for it: */
 514                                 !(s->verify_mode & SSL_VERIFY_PEER) ||
 515                                 /* if SSL_VERIFY_CLIENT_ONCE is set,
 516                                  * don't request cert during re-negotiation: */
 517                                 ((s->session->peer != NULL) &&
 518                                  (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
 519                                 /* never request cert in anonymous ciphersuites
 520                                  * (see section "Certificate request" in SSL 3 drafts
 521                                  * and in RFC 2246): */
 522                                 ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
 523                                  /* ... except when the application insists on verification
 524                                   * (against the specs, but s3_clnt.c accepts this for SSL 3) */
 525                                  !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
 526                                  /* never request cert in Kerberos ciphersuites */
 527                                 (s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5)
 528                                 /* With normal PSK Certificates and
 529                                  * Certificate Requests are omitted */
 530                                 || (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK))
 531                                 {
 532                                 /* no cert request */
 533                                 skip=1;
 534                                 s->s3->tmp.cert_request=0;
 535                                 s->state=SSL3_ST_SW_SRVR_DONE_A;
 536 #ifndef OPENSSL_NO_SCTP
 537                                 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 538                                         {
 539                                         s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 540                                         s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 541                                         }
 542 #endif
 543                                 }
 544                         else
 545                                 {
 546                                 s->s3->tmp.cert_request=1;
 547                                 dtls1_start_timer(s);
 548                                 ret=ssl3_send_certificate_request(s);
 549                                 if (ret <= 0) goto end;
 550 #ifndef NETSCAPE_HANG_BUG
 551                                 s->state=SSL3_ST_SW_SRVR_DONE_A;
 552 #ifndef OPENSSL_NO_SCTP
 553                                 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 554                                         {
 555                                         s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 556                                         s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 557                                         }
 558 #endif
 559 #else
 560                                 s->state=SSL3_ST_SW_FLUSH;
 561                                 s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
 562 #ifndef OPENSSL_NO_SCTP
 563                                 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 564                                         {
 565                                         s->d1->next_state = s->s3->tmp.next_state;
 566                                         s->s3->tmp.next_state=DTLS1_SCTP_ST_SW_WRITE_SOCK;
 567                                         }
 568 #endif
 569 #endif
 570                                 s->init_num=0;
 571                                 }
 572                         break;
 573
 574                 case SSL3_ST_SW_SRVR_DONE_A:
 575                 case SSL3_ST_SW_SRVR_DONE_B:
 576                         dtls1_start_timer(s);
 577                         ret=ssl3_send_server_done(s);
 578                         if (ret <= 0) goto end;
 579                         s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
 580                         s->state=SSL3_ST_SW_FLUSH;
 581                         s->init_num=0;
 582                         break;
 583
 584                 case SSL3_ST_SW_FLUSH:
 585                         s->rwstate=SSL_WRITING;
 586                         if (BIO_flush(s->wbio) <= 0)
 587                                 {
 588                                 /* If the write error was fatal, stop trying */
 589                                 if (!BIO_should_retry(s->wbio))
 590                                         {
 591                                         s->rwstate=SSL_NOTHING;
 592                                         s->state=s->s3->tmp.next_state;
 593                                         }
 594
 595                                 ret= -1;
 596                                 goto end;
 597                                 }
 598                         s->rwstate=SSL_NOTHING;
 599                         s->state=s->s3->tmp.next_state;
 600                         break;
 601
 602                 case SSL3_ST_SR_CERT_A:
 603                 case SSL3_ST_SR_CERT_B:
 604                         if (s->s3->tmp.cert_request)
 605                                 {
 606                                 ret=ssl3_get_client_certificate(s);
 607                                 if (ret <= 0) goto end;
 608                                 }
 609                         s->init_num=0;
 610                         s->state=SSL3_ST_SR_KEY_EXCH_A;
 611                         break;
 612
 613                 case SSL3_ST_SR_KEY_EXCH_A:
 614                 case SSL3_ST_SR_KEY_EXCH_B:
 615                         ret=ssl3_get_client_key_exchange(s);
 616                         if (ret <= 0) goto end;
 617 #ifndef OPENSSL_NO_SCTP
 618                         /* Add new shared key for SCTP-Auth,
 619                          * will be ignored if no SCTP used.
 620                          */
 621                         snprintf((char *) labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 622                                  DTLS1_SCTP_AUTH_LABEL);
 623
 624                         SSL_export_keying_material(s, sctpauthkey,
 625                                                    sizeof(sctpauthkey), labelbuffer,
 626                                                    sizeof(labelbuffer), NULL, 0, 0);
 627
 628                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 629                                  sizeof(sctpauthkey), sctpauthkey);
 630 #endif
 631
 632                         s->state=SSL3_ST_SR_CERT_VRFY_A;
 633                         s->init_num=0;
 634
 635                         if (ret == 2)
 636                                 {
 637                                 /* For the ECDH ciphersuites when
 638                                  * the client sends its ECDH pub key in
 639                                  * a certificate, the CertificateVerify
 640                                  * message is not sent.
 641                                  */
 642                                 s->state=SSL3_ST_SR_FINISHED_A;
 643                                 s->init_num = 0;
 644                                 }
 645                         else if (SSL_USE_SIGALGS(s))
 646                                 {
 647                                 s->state=SSL3_ST_SR_CERT_VRFY_A;
 648                                 s->init_num=0;
 649                                 if (!s->session->peer)
 650                                         break;
 651                                 /* For sigalgs freeze the handshake buffer
 652                                  * at this point and digest cached records.
 653                                  */
 654                                 if (!s->s3->handshake_buffer)
 655                                         {
 656                                         SSLerr(SSL_F_DTLS1_ACCEPT,ERR_R_INTERNAL_ERROR);
 657                                         return -1;
 658                                         }
 659                                 s->s3->flags |= TLS1_FLAGS_KEEP_HANDSHAKE;
 660                                 if (!ssl3_digest_cached_records(s))
 661                                         return -1;
 662                                 }
 663                         else
 664                                 {
 665                                 s->state=SSL3_ST_SR_CERT_VRFY_A;
 666                                 s->init_num=0;
 667
 668                                 /* We need to get hashes here so if there is
 669                                  * a client cert, it can be verified */
 670                                 s->method->ssl3_enc->cert_verify_mac(s,
 671                                         NID_md5,
 672                                         &(s->s3->tmp.cert_verify_md[0]));
 673                                 s->method->ssl3_enc->cert_verify_mac(s,
 674                                         NID_sha1,
 675                                         &(s->s3->tmp.cert_verify_md[MD5_DIGEST_LENGTH]));
 676                                 }
 677                         break;
 678
 679                 case SSL3_ST_SR_CERT_VRFY_A:
 680                 case SSL3_ST_SR_CERT_VRFY_B:
 681                         /*
 682                          * This *should* be the first time we enable CCS, but be
 683                          * extra careful about surrounding code changes. We need
 684                          * to set this here because we don't know if we're
 685                          * expecting a CertificateVerify or not.
 686                          */
 687                         if (!s->s3->change_cipher_spec)
 688                                 s->d1->change_cipher_spec_ok = 1;
 689                         /* we should decide if we expected this one */
 690                         ret=ssl3_get_cert_verify(s);
 691                         if (ret <= 0) goto end;
 692 #ifndef OPENSSL_NO_SCTP
 693                         if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
 694                             state == SSL_ST_RENEGOTIATE)
 695                                 s->state=DTLS1_SCTP_ST_SR_READ_SOCK;
 696                         else
 697 #endif
 698                                 s->state=SSL3_ST_SR_FINISHED_A;
 699                         s->init_num=0;
 700                         break;
 701
 702                 case SSL3_ST_SR_FINISHED_A:
 703                 case SSL3_ST_SR_FINISHED_B:
 704                         /*
 705                          * Enable CCS for resumed handshakes.
 706                          * In a full handshake, we end up here through
 707                          * SSL3_ST_SR_CERT_VRFY_B, so change_cipher_spec_ok was
 708                          * already set. Receiving a CCS clears the flag, so make
 709                          * sure not to re-enable it to ban duplicates.
 710                          * s->s3->change_cipher_spec is set when a CCS is
 711                          * processed in d1_pkt.c, and remains set until
 712                          * the client's Finished message is read.
 713                          */
 714                         if (!s->s3->change_cipher_spec)
 715                                 s->d1->change_cipher_spec_ok = 1;
 716                         ret=ssl3_get_finished(s,SSL3_ST_SR_FINISHED_A,
 717                                 SSL3_ST_SR_FINISHED_B);
 718                         if (ret <= 0) goto end;
 719                         dtls1_stop_timer(s);
 720                         if (s->hit)
 721                                 s->state=SSL_ST_OK;
 722 #ifndef OPENSSL_NO_TLSEXT
 723                         else if (s->tlsext_ticket_expected)
 724                                 s->state=SSL3_ST_SW_SESSION_TICKET_A;
 725 #endif
 726                         else
 727                                 s->state=SSL3_ST_SW_CHANGE_A;
 728                         s->init_num=0;
 729                         break;
 730
 731 #ifndef OPENSSL_NO_TLSEXT
 732                 case SSL3_ST_SW_SESSION_TICKET_A:
 733                 case SSL3_ST_SW_SESSION_TICKET_B:
 734                         ret=ssl3_send_newsession_ticket(s);
 735                         if (ret <= 0) goto end;
 736                         s->state=SSL3_ST_SW_CHANGE_A;
 737                         s->init_num=0;
 738                         break;
 739
 740                 case SSL3_ST_SW_CERT_STATUS_A:
 741                 case SSL3_ST_SW_CERT_STATUS_B:
 742                         ret=ssl3_send_cert_status(s);
 743                         if (ret <= 0) goto end;
 744                         s->state=SSL3_ST_SW_KEY_EXCH_A;
 745                         s->init_num=0;
 746                         break;
 747
 748 #endif
 749
 750                 case SSL3_ST_SW_CHANGE_A:
 751                 case SSL3_ST_SW_CHANGE_B:
 752
 753                         s->session->cipher=s->s3->tmp.new_cipher;
 754                         if (!s->method->ssl3_enc->setup_key_block(s))
 755                                 { ret= -1; goto end; }
 756
 757                         ret=dtls1_send_change_cipher_spec(s,
 758                                 SSL3_ST_SW_CHANGE_A,SSL3_ST_SW_CHANGE_B);
 759
 760                         if (ret <= 0) goto end;
 761
 762 #ifndef OPENSSL_NO_SCTP
 763                         if (!s->hit)
 764                                 {
 765                                 /* Change to new shared key of SCTP-Auth,
 766                                  * will be ignored if no SCTP used.
 767                                  */
 768                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY, 0, NULL);
 769                                 }
 770 #endif
 771
 772                         s->state=SSL3_ST_SW_FINISHED_A;
 773                         s->init_num=0;
 774
 775                         if (!s->method->ssl3_enc->change_cipher_state(s,
 776                                 SSL3_CHANGE_CIPHER_SERVER_WRITE))
 777                                 {
 778                                 ret= -1;
 779                                 goto end;
 780                                 }
 781
 782                         dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
 783                         break;
 784
 785                 case SSL3_ST_SW_FINISHED_A:
 786                 case SSL3_ST_SW_FINISHED_B:
 787                         ret=ssl3_send_finished(s,
 788                                 SSL3_ST_SW_FINISHED_A,SSL3_ST_SW_FINISHED_B,
 789                                 s->method->ssl3_enc->server_finished_label,
 790                                 s->method->ssl3_enc->server_finished_label_len);
 791                         if (ret <= 0) goto end;
 792                         s->state=SSL3_ST_SW_FLUSH;
 793                         if (s->hit)
 794                                 {
 795                                 s->s3->tmp.next_state=SSL3_ST_SR_FINISHED_A;
 796
 797 #ifndef OPENSSL_NO_SCTP
 798                                 /* Change to new shared key of SCTP-Auth,
 799                                  * will be ignored if no SCTP used.
 800                                  */
 801                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY, 0, NULL);
 802 #endif
 803                                 }
 804                         else
 805                                 {
 806                                 s->s3->tmp.next_state=SSL_ST_OK;
 807 #ifndef OPENSSL_NO_SCTP
 808                                 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 809                                         {
 810                                         s->d1->next_state = s->s3->tmp.next_state;
 811                                         s->s3->tmp.next_state=DTLS1_SCTP_ST_SW_WRITE_SOCK;
 812                                         }
 813 #endif
 814                                 }
 815                         s->init_num=0;
 816                         break;
 817
 818                 case SSL_ST_OK:
 819                         /* clean a few things up */
 820                         ssl3_cleanup_key_block(s);
 821
 822 #if 0
 823                         BUF_MEM_free(s->init_buf);
 824                         s->init_buf=NULL;
 825 #endif
 826
 827                         /* remove buffering on output */
 828                         ssl_free_wbio_buffer(s);
 829
 830                         s->init_num=0;
 831
 832                         if (s->renegotiate == 2) /* skipped if we just sent a HelloRequest */
 833                                 {
 834                                 s->renegotiate=0;
 835                                 s->new_session=0;
 836
 837                                 ssl_update_cache(s,SSL_SESS_CACHE_SERVER);
 838
 839                                 s->ctx->stats.sess_accept_good++;
 840                                 /* s->server=1; */
 841                                 s->handshake_func=dtls1_accept;
 842
 843                                 if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_DONE,1);
 844                                 }
 845
 846                         ret = 1;
 847
 848                         /* done handshaking, next message is client hello */
 849                         s->d1->handshake_read_seq = 0;
 850                         /* next message is server hello */
 851                         s->d1->handshake_write_seq = 0;
 852                         s->d1->next_handshake_write_seq = 0;
 853                         goto end;
 854                         /* break; */
 855
 856                 default:
 857                         SSLerr(SSL_F_DTLS1_ACCEPT,SSL_R_UNKNOWN_STATE);
 858                         ret= -1;
 859                         goto end;
 860                         /* break; */
 861                         }
 862
 863                 if (!s->s3->tmp.reuse_message && !skip)
 864                         {
 865                         if (s->debug)
 866                                 {
 867                                 if ((ret=BIO_flush(s->wbio)) <= 0)
 868                                         goto end;
 869                                 }
 870
 871
 872                         if ((cb != NULL) && (s->state != state))
 873                                 {
 874                                 new_state=s->state;
 875                                 s->state=state;
 876                                 cb(s,SSL_CB_ACCEPT_LOOP,1);
 877                                 s->state=new_state;
 878                                 }
 879                         }
 880                 skip=0;
 881                 }
 882 end:
 883         /* BIO_flush(s->wbio); */
 884
 885         s->in_handshake--;
 886 #ifndef OPENSSL_NO_SCTP
 887                 /* Notify SCTP BIO socket to leave handshake
 888                  * mode and prevent stream identifier other
 889                  * than 0. Will be ignored if no SCTP is used.
 890                  */
 891                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE, s->in_handshake, NULL);
 892 #endif
 893
 894         if (cb != NULL)
 895                 cb(s,SSL_CB_ACCEPT_EXIT,ret);
 896         return(ret);
 897         }
 898
 899 int dtls1_send_hello_verify_request(SSL *s)
 900         {
 901         unsigned int msg_len;
 902         unsigned char *msg, *buf, *p;
 903
 904         if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A)
 905                 {
 906                 buf = (unsigned char *)s->init_buf->data;
 907
 908                 msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
 909                 /* Always use DTLS 1.0 version: see RFC 6347 */
 910                 *(p++) = DTLS1_VERSION >> 8;
 911                 *(p++) = DTLS1_VERSION & 0xFF;
 912
 913                 if (s->ctx->app_gen_cookie_cb == NULL ||
 914                      s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
 915                          &(s->d1->cookie_len)) == 0)
 916                         {
 917                         SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,ERR_R_INTERNAL_ERROR);
 918                         return 0;
 919                         }
 920
 921                 *(p++) = (unsigned char) s->d1->cookie_len;
 922                 memcpy(p, s->d1->cookie, s->d1->cookie_len);
 923                 p += s->d1->cookie_len;
 924                 msg_len = p - msg;
 925
 926                 dtls1_set_message_header(s, buf,
 927                         DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0, msg_len);
 928
 929                 s->state=DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
 930                 /* number of bytes to write */
 931                 s->init_num=p-buf;
 932                 s->init_off=0;
 933                 }
 934
 935         /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
 936         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 937         }