crypto/openssl/ssl/d1_clnt.c

   1 /* ssl/d1_clnt.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 #ifndef OPENSSL_NO_KRB5
 119 # include "kssl_lcl.h"
 120 #endif
 121 #include <openssl/buffer.h>
 122 #include <openssl/rand.h>
 123 #include <openssl/objects.h>
 124 #include <openssl/evp.h>
 125 #include <openssl/md5.h>
 126 #include <openssl/bn.h>
 127 #ifndef OPENSSL_NO_DH
 128 # include <openssl/dh.h>
 129 #endif
 130
 131 static const SSL_METHOD *dtls1_get_client_method(int ver);
 132 static int dtls1_get_hello_verify(SSL *s);
 133
 134 static const SSL_METHOD *dtls1_get_client_method(int ver)
 135 {
 136     if (ver == DTLS_ANY_VERSION)
 137         return DTLS_client_method();
 138     else if (ver == DTLS1_VERSION || ver == DTLS1_BAD_VER)
 139         return DTLSv1_client_method();
 140     else if (ver == DTLS1_2_VERSION)
 141         return DTLSv1_2_client_method();
 142     else
 143         return NULL;
 144 }
 145
 146 IMPLEMENT_dtls1_meth_func(DTLS1_VERSION,
 147                           DTLSv1_client_method,
 148                           ssl_undefined_function,
 149                           dtls1_connect,
 150                           dtls1_get_client_method, DTLSv1_enc_data)
 151
 152 IMPLEMENT_dtls1_meth_func(DTLS1_2_VERSION,
 153                           DTLSv1_2_client_method,
 154                           ssl_undefined_function,
 155                           dtls1_connect,
 156                           dtls1_get_client_method, DTLSv1_2_enc_data)
 157
 158 IMPLEMENT_dtls1_meth_func(DTLS_ANY_VERSION,
 159                           DTLS_client_method,
 160                           ssl_undefined_function,
 161                           dtls1_connect,
 162                           dtls1_get_client_method, DTLSv1_2_enc_data)
 163
 164 int dtls1_connect(SSL *s)
 165 {
 166     BUF_MEM *buf = NULL;
 167     unsigned long Time = (unsigned long)time(NULL);
 168     void (*cb) (const SSL *ssl, int type, int val) = NULL;
 169     int ret = -1;
 170     int new_state, state, skip = 0;
 171 #ifndef OPENSSL_NO_SCTP
 172     unsigned char sctpauthkey[64];
 173     char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
 174 #endif
 175
 176     RAND_add(&Time, sizeof(Time), 0);
 177     ERR_clear_error();
 178     clear_sys_error();
 179
 180     if (s->info_callback != NULL)
 181         cb = s->info_callback;
 182     else if (s->ctx->info_callback != NULL)
 183         cb = s->ctx->info_callback;
 184
 185     s->in_handshake++;
 186     if (!SSL_in_init(s) || SSL_in_before(s))
 187         SSL_clear(s);
 188
 189 #ifndef OPENSSL_NO_SCTP
 190     /*
 191      * Notify SCTP BIO socket to enter handshake mode and prevent stream
 192      * identifier other than 0. Will be ignored if no SCTP is used.
 193      */
 194     BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
 195              s->in_handshake, NULL);
 196 #endif
 197
 198 #ifndef OPENSSL_NO_HEARTBEATS
 199     /*
 200      * If we're awaiting a HeartbeatResponse, pretend we already got and
 201      * don't await it anymore, because Heartbeats don't make sense during
 202      * handshakes anyway.
 203      */
 204     if (s->tlsext_hb_pending) {
 205         dtls1_stop_timer(s);
 206         s->tlsext_hb_pending = 0;
 207         s->tlsext_hb_seq++;
 208     }
 209 #endif
 210
 211     for (;;) {
 212         state = s->state;
 213
 214         switch (s->state) {
 215         case SSL_ST_RENEGOTIATE:
 216             s->renegotiate = 1;
 217             s->state = SSL_ST_CONNECT;
 218             s->ctx->stats.sess_connect_renegotiate++;
 219             /* break */
 220         case SSL_ST_BEFORE:
 221         case SSL_ST_CONNECT:
 222         case SSL_ST_BEFORE | SSL_ST_CONNECT:
 223         case SSL_ST_OK | SSL_ST_CONNECT:
 224
 225             s->server = 0;
 226             if (cb != NULL)
 227                 cb(s, SSL_CB_HANDSHAKE_START, 1);
 228
 229             if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00) &&
 230                 (s->version & 0xff00) != (DTLS1_BAD_VER & 0xff00)) {
 231                 SSLerr(SSL_F_DTLS1_CONNECT, ERR_R_INTERNAL_ERROR);
 232                 ret = -1;
 233                 s->state = SSL_ST_ERR;
 234                 goto end;
 235             }
 236
 237             /* s->version=SSL3_VERSION; */
 238             s->type = SSL_ST_CONNECT;
 239
 240             if (s->init_buf == NULL) {
 241                 if ((buf = BUF_MEM_new()) == NULL) {
 242                     ret = -1;
 243                     s->state = SSL_ST_ERR;
 244                     goto end;
 245                 }
 246                 if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
 247                     ret = -1;
 248                     s->state = SSL_ST_ERR;
 249                     goto end;
 250                 }
 251                 s->init_buf = buf;
 252                 buf = NULL;
 253             }
 254
 255             if (!ssl3_setup_buffers(s)) {
 256                 ret = -1;
 257                 s->state = SSL_ST_ERR;
 258                 goto end;
 259             }
 260
 261             /* setup buffing BIO */
 262             if (!ssl_init_wbio_buffer(s, 0)) {
 263                 ret = -1;
 264                 s->state = SSL_ST_ERR;
 265                 goto end;
 266             }
 267
 268             /* don't push the buffering BIO quite yet */
 269
 270             s->state = SSL3_ST_CW_CLNT_HELLO_A;
 271             s->ctx->stats.sess_connect++;
 272             s->init_num = 0;
 273             /* mark client_random uninitialized */
 274             memset(s->s3->client_random, 0, sizeof(s->s3->client_random));
 275             s->d1->send_cookie = 0;
 276             s->hit = 0;
 277             s->d1->change_cipher_spec_ok = 0;
 278             /*
 279              * Should have been reset by ssl3_get_finished, too.
 280              */
 281             s->s3->change_cipher_spec = 0;
 282             break;
 283
 284 #ifndef OPENSSL_NO_SCTP
 285         case DTLS1_SCTP_ST_CR_READ_SOCK:
 286
 287             if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
 288                 s->s3->in_read_app_data = 2;
 289                 s->rwstate = SSL_READING;
 290                 BIO_clear_retry_flags(SSL_get_rbio(s));
 291                 BIO_set_retry_read(SSL_get_rbio(s));
 292                 ret = -1;
 293                 goto end;
 294             }
 295
 296             s->state = s->s3->tmp.next_state;
 297             break;
 298
 299         case DTLS1_SCTP_ST_CW_WRITE_SOCK:
 300             /* read app data until dry event */
 301
 302             ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
 303             if (ret < 0)
 304                 goto end;
 305
 306             if (ret == 0) {
 307                 s->s3->in_read_app_data = 2;
 308                 s->rwstate = SSL_READING;
 309                 BIO_clear_retry_flags(SSL_get_rbio(s));
 310                 BIO_set_retry_read(SSL_get_rbio(s));
 311                 ret = -1;
 312                 goto end;
 313             }
 314
 315             s->state = s->d1->next_state;
 316             break;
 317 #endif
 318
 319         case SSL3_ST_CW_CLNT_HELLO_A:
 320             s->shutdown = 0;
 321
 322             /* every DTLS ClientHello resets Finished MAC */
 323             ssl3_init_finished_mac(s);
 324
 325         case SSL3_ST_CW_CLNT_HELLO_B:
 326             dtls1_start_timer(s);
 327             ret = ssl3_client_hello(s);
 328             if (ret <= 0)
 329                 goto end;
 330
 331             if (s->d1->send_cookie) {
 332                 s->state = SSL3_ST_CW_FLUSH;
 333                 s->s3->tmp.next_state = SSL3_ST_CR_SRVR_HELLO_A;
 334             } else
 335                 s->state = SSL3_ST_CR_SRVR_HELLO_A;
 336
 337             s->init_num = 0;
 338
 339 #ifndef OPENSSL_NO_SCTP
 340             /* Disable buffering for SCTP */
 341             if (!BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 342 #endif
 343                 /*
 344                  * turn on buffering for the next lot of output
 345                  */
 346                 if (s->bbio != s->wbio)
 347                     s->wbio = BIO_push(s->bbio, s->wbio);
 348 #ifndef OPENSSL_NO_SCTP
 349             }
 350 #endif
 351
 352             break;
 353
 354         case SSL3_ST_CR_SRVR_HELLO_A:
 355         case SSL3_ST_CR_SRVR_HELLO_B:
 356             ret = ssl3_get_server_hello(s);
 357             if (ret <= 0)
 358                 goto end;
 359             else {
 360                 if (s->hit) {
 361 #ifndef OPENSSL_NO_SCTP
 362                     /*
 363                      * Add new shared key for SCTP-Auth, will be ignored if
 364                      * no SCTP used.
 365                      */
 366                     snprintf((char *)labelbuffer,
 367                              sizeof(DTLS1_SCTP_AUTH_LABEL),
 368                              DTLS1_SCTP_AUTH_LABEL);
 369
 370                     if (SSL_export_keying_material(s, sctpauthkey,
 371                                                sizeof(sctpauthkey),
 372                                                labelbuffer,
 373                                                sizeof(labelbuffer), NULL, 0,
 374                                                0) <= 0) {
 375                         ret = -1;
 376                         s->state = SSL_ST_ERR;
 377                         goto end;
 378                     }
 379
 380                     BIO_ctrl(SSL_get_wbio(s),
 381                              BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 382                              sizeof(sctpauthkey), sctpauthkey);
 383 #endif
 384
 385                     s->state = SSL3_ST_CR_FINISHED_A;
 386                     if (s->tlsext_ticket_expected) {
 387                         /* receive renewed session ticket */
 388                         s->state = SSL3_ST_CR_SESSION_TICKET_A;
 389                     }
 390                 } else
 391                     s->state = DTLS1_ST_CR_HELLO_VERIFY_REQUEST_A;
 392             }
 393             s->init_num = 0;
 394             break;
 395
 396         case DTLS1_ST_CR_HELLO_VERIFY_REQUEST_A:
 397         case DTLS1_ST_CR_HELLO_VERIFY_REQUEST_B:
 398
 399             ret = dtls1_get_hello_verify(s);
 400             if (ret <= 0)
 401                 goto end;
 402             dtls1_stop_timer(s);
 403             if (s->d1->send_cookie) /* start again, with a cookie */
 404                 s->state = SSL3_ST_CW_CLNT_HELLO_A;
 405             else
 406                 s->state = SSL3_ST_CR_CERT_A;
 407             s->init_num = 0;
 408             break;
 409
 410         case SSL3_ST_CR_CERT_A:
 411         case SSL3_ST_CR_CERT_B:
 412             /* Check if it is anon DH or PSK */
 413             if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
 414                 !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
 415                 ret = ssl3_get_server_certificate(s);
 416                 if (ret <= 0)
 417                     goto end;
 418 #ifndef OPENSSL_NO_TLSEXT
 419                 if (s->tlsext_status_expected)
 420                     s->state = SSL3_ST_CR_CERT_STATUS_A;
 421                 else
 422                     s->state = SSL3_ST_CR_KEY_EXCH_A;
 423             } else {
 424                 skip = 1;
 425                 s->state = SSL3_ST_CR_KEY_EXCH_A;
 426             }
 427 #else
 428             } else
 429                 skip = 1;
 430
 431             s->state = SSL3_ST_CR_KEY_EXCH_A;
 432 #endif
 433             s->init_num = 0;
 434             break;
 435
 436         case SSL3_ST_CR_KEY_EXCH_A:
 437         case SSL3_ST_CR_KEY_EXCH_B:
 438             ret = ssl3_get_key_exchange(s);
 439             if (ret <= 0)
 440                 goto end;
 441             s->state = SSL3_ST_CR_CERT_REQ_A;
 442             s->init_num = 0;
 443
 444             /*
 445              * at this point we check that we have the required stuff from
 446              * the server
 447              */
 448             if (!ssl3_check_cert_and_algorithm(s)) {
 449                 ret = -1;
 450                 s->state = SSL_ST_ERR;
 451                 goto end;
 452             }
 453             break;
 454
 455         case SSL3_ST_CR_CERT_REQ_A:
 456         case SSL3_ST_CR_CERT_REQ_B:
 457             ret = ssl3_get_certificate_request(s);
 458             if (ret <= 0)
 459                 goto end;
 460             s->state = SSL3_ST_CR_SRVR_DONE_A;
 461             s->init_num = 0;
 462             break;
 463
 464         case SSL3_ST_CR_SRVR_DONE_A:
 465         case SSL3_ST_CR_SRVR_DONE_B:
 466             ret = ssl3_get_server_done(s);
 467             if (ret <= 0)
 468                 goto end;
 469             dtls1_stop_timer(s);
 470             if (s->s3->tmp.cert_req)
 471                 s->s3->tmp.next_state = SSL3_ST_CW_CERT_A;
 472             else
 473                 s->s3->tmp.next_state = SSL3_ST_CW_KEY_EXCH_A;
 474             s->init_num = 0;
 475
 476 #ifndef OPENSSL_NO_SCTP
 477             if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
 478                 state == SSL_ST_RENEGOTIATE)
 479                 s->state = DTLS1_SCTP_ST_CR_READ_SOCK;
 480             else
 481 #endif
 482                 s->state = s->s3->tmp.next_state;
 483             break;
 484
 485         case SSL3_ST_CW_CERT_A:
 486         case SSL3_ST_CW_CERT_B:
 487         case SSL3_ST_CW_CERT_C:
 488         case SSL3_ST_CW_CERT_D:
 489             dtls1_start_timer(s);
 490             ret = ssl3_send_client_certificate(s);
 491             if (ret <= 0)
 492                 goto end;
 493             s->state = SSL3_ST_CW_KEY_EXCH_A;
 494             s->init_num = 0;
 495             break;
 496
 497         case SSL3_ST_CW_KEY_EXCH_A:
 498         case SSL3_ST_CW_KEY_EXCH_B:
 499             dtls1_start_timer(s);
 500             ret = ssl3_send_client_key_exchange(s);
 501             if (ret <= 0)
 502                 goto end;
 503
 504 #ifndef OPENSSL_NO_SCTP
 505             /*
 506              * Add new shared key for SCTP-Auth, will be ignored if no SCTP
 507              * used.
 508              */
 509             snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 510                      DTLS1_SCTP_AUTH_LABEL);
 511
 512             if (SSL_export_keying_material(s, sctpauthkey,
 513                                        sizeof(sctpauthkey), labelbuffer,
 514                                        sizeof(labelbuffer), NULL, 0, 0) <= 0) {
 515                 ret = -1;
 516                 s->state = SSL_ST_ERR;
 517                 goto end;
 518             }
 519
 520             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 521                      sizeof(sctpauthkey), sctpauthkey);
 522 #endif
 523
 524             /*
 525              * EAY EAY EAY need to check for DH fix cert sent back
 526              */
 527             /*
 528              * For TLS, cert_req is set to 2, so a cert chain of nothing is
 529              * sent, but no verify packet is sent
 530              */
 531             if (s->s3->tmp.cert_req == 1) {
 532                 s->state = SSL3_ST_CW_CERT_VRFY_A;
 533             } else {
 534 #ifndef OPENSSL_NO_SCTP
 535                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 536                     s->d1->next_state = SSL3_ST_CW_CHANGE_A;
 537                     s->state = DTLS1_SCTP_ST_CW_WRITE_SOCK;
 538                 } else
 539 #endif
 540                     s->state = SSL3_ST_CW_CHANGE_A;
 541             }
 542
 543             s->init_num = 0;
 544             break;
 545
 546         case SSL3_ST_CW_CERT_VRFY_A:
 547         case SSL3_ST_CW_CERT_VRFY_B:
 548             dtls1_start_timer(s);
 549             ret = ssl3_send_client_verify(s);
 550             if (ret <= 0)
 551                 goto end;
 552 #ifndef OPENSSL_NO_SCTP
 553             if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 554                 s->d1->next_state = SSL3_ST_CW_CHANGE_A;
 555                 s->state = DTLS1_SCTP_ST_CW_WRITE_SOCK;
 556             } else
 557 #endif
 558                 s->state = SSL3_ST_CW_CHANGE_A;
 559             s->init_num = 0;
 560             break;
 561
 562         case SSL3_ST_CW_CHANGE_A:
 563         case SSL3_ST_CW_CHANGE_B:
 564             if (!s->hit)
 565                 dtls1_start_timer(s);
 566             ret = dtls1_send_change_cipher_spec(s,
 567                                                 SSL3_ST_CW_CHANGE_A,
 568                                                 SSL3_ST_CW_CHANGE_B);
 569             if (ret <= 0)
 570                 goto end;
 571
 572             s->state = SSL3_ST_CW_FINISHED_A;
 573             s->init_num = 0;
 574
 575             s->session->cipher = s->s3->tmp.new_cipher;
 576 #ifdef OPENSSL_NO_COMP
 577             s->session->compress_meth = 0;
 578 #else
 579             if (s->s3->tmp.new_compression == NULL)
 580                 s->session->compress_meth = 0;
 581             else
 582                 s->session->compress_meth = s->s3->tmp.new_compression->id;
 583 #endif
 584             if (!s->method->ssl3_enc->setup_key_block(s)) {
 585                 ret = -1;
 586                 s->state = SSL_ST_ERR;
 587                 goto end;
 588             }
 589
 590             if (!s->method->ssl3_enc->change_cipher_state(s,
 591                                                           SSL3_CHANGE_CIPHER_CLIENT_WRITE))
 592             {
 593                 ret = -1;
 594                 s->state = SSL_ST_ERR;
 595                 goto end;
 596             }
 597 #ifndef OPENSSL_NO_SCTP
 598             if (s->hit) {
 599                 /*
 600                  * Change to new shared key of SCTP-Auth, will be ignored if
 601                  * no SCTP used.
 602                  */
 603                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 604                          0, NULL);
 605             }
 606 #endif
 607
 608             dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
 609             break;
 610
 611         case SSL3_ST_CW_FINISHED_A:
 612         case SSL3_ST_CW_FINISHED_B:
 613             if (!s->hit)
 614                 dtls1_start_timer(s);
 615             ret = ssl3_send_finished(s,
 616                                      SSL3_ST_CW_FINISHED_A,
 617                                      SSL3_ST_CW_FINISHED_B,
 618                                      s->method->
 619                                      ssl3_enc->client_finished_label,
 620                                      s->method->
 621                                      ssl3_enc->client_finished_label_len);
 622             if (ret <= 0)
 623                 goto end;
 624             s->state = SSL3_ST_CW_FLUSH;
 625
 626             /* clear flags */
 627             s->s3->flags &= ~SSL3_FLAGS_POP_BUFFER;
 628             if (s->hit) {
 629                 s->s3->tmp.next_state = SSL_ST_OK;
 630 #ifndef OPENSSL_NO_SCTP
 631                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 632                     s->d1->next_state = s->s3->tmp.next_state;
 633                     s->s3->tmp.next_state = DTLS1_SCTP_ST_CW_WRITE_SOCK;
 634                 }
 635 #endif
 636                 if (s->s3->flags & SSL3_FLAGS_DELAY_CLIENT_FINISHED) {
 637                     s->state = SSL_ST_OK;
 638 #ifndef OPENSSL_NO_SCTP
 639                     if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 640                         s->d1->next_state = SSL_ST_OK;
 641                         s->state = DTLS1_SCTP_ST_CW_WRITE_SOCK;
 642                     }
 643 #endif
 644                     s->s3->flags |= SSL3_FLAGS_POP_BUFFER;
 645                     s->s3->delay_buf_pop_ret = 0;
 646                 }
 647             } else {
 648 #ifndef OPENSSL_NO_SCTP
 649                 /*
 650                  * Change to new shared key of SCTP-Auth, will be ignored if
 651                  * no SCTP used.
 652                  */
 653                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 654                          0, NULL);
 655 #endif
 656
 657 #ifndef OPENSSL_NO_TLSEXT
 658                 /*
 659                  * Allow NewSessionTicket if ticket expected
 660                  */
 661                 if (s->tlsext_ticket_expected)
 662                     s->s3->tmp.next_state = SSL3_ST_CR_SESSION_TICKET_A;
 663                 else
 664 #endif
 665
 666                     s->s3->tmp.next_state = SSL3_ST_CR_FINISHED_A;
 667             }
 668             s->init_num = 0;
 669             break;
 670
 671 #ifndef OPENSSL_NO_TLSEXT
 672         case SSL3_ST_CR_SESSION_TICKET_A:
 673         case SSL3_ST_CR_SESSION_TICKET_B:
 674             ret = ssl3_get_new_session_ticket(s);
 675             if (ret <= 0)
 676                 goto end;
 677             s->state = SSL3_ST_CR_FINISHED_A;
 678             s->init_num = 0;
 679             break;
 680
 681         case SSL3_ST_CR_CERT_STATUS_A:
 682         case SSL3_ST_CR_CERT_STATUS_B:
 683             ret = ssl3_get_cert_status(s);
 684             if (ret <= 0)
 685                 goto end;
 686             s->state = SSL3_ST_CR_KEY_EXCH_A;
 687             s->init_num = 0;
 688             break;
 689 #endif
 690
 691         case SSL3_ST_CR_FINISHED_A:
 692         case SSL3_ST_CR_FINISHED_B:
 693             s->d1->change_cipher_spec_ok = 1;
 694             ret = ssl3_get_finished(s, SSL3_ST_CR_FINISHED_A,
 695                                     SSL3_ST_CR_FINISHED_B);
 696             if (ret <= 0)
 697                 goto end;
 698             dtls1_stop_timer(s);
 699
 700             if (s->hit)
 701                 s->state = SSL3_ST_CW_CHANGE_A;
 702             else
 703                 s->state = SSL_ST_OK;
 704
 705 #ifndef OPENSSL_NO_SCTP
 706             if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
 707                 state == SSL_ST_RENEGOTIATE) {
 708                 s->d1->next_state = s->state;
 709                 s->state = DTLS1_SCTP_ST_CW_WRITE_SOCK;
 710             }
 711 #endif
 712
 713             s->init_num = 0;
 714             break;
 715
 716         case SSL3_ST_CW_FLUSH:
 717             s->rwstate = SSL_WRITING;
 718             if (BIO_flush(s->wbio) <= 0) {
 719                 /*
 720                  * If the write error was fatal, stop trying
 721                  */
 722                 if (!BIO_should_retry(s->wbio)) {
 723                     s->rwstate = SSL_NOTHING;
 724                     s->state = s->s3->tmp.next_state;
 725                 }
 726
 727                 ret = -1;
 728                 goto end;
 729             }
 730             s->rwstate = SSL_NOTHING;
 731             s->state = s->s3->tmp.next_state;
 732             break;
 733
 734         case SSL_ST_OK:
 735             /* clean a few things up */
 736             ssl3_cleanup_key_block(s);
 737
 738 #if 0
 739             if (s->init_buf != NULL) {
 740                 BUF_MEM_free(s->init_buf);
 741                 s->init_buf = NULL;
 742             }
 743 #endif
 744
 745             /*
 746              * If we are not 'joining' the last two packets, remove the
 747              * buffering now
 748              */
 749             if (!(s->s3->flags & SSL3_FLAGS_POP_BUFFER))
 750                 ssl_free_wbio_buffer(s);
 751             /* else do it later in ssl3_write */
 752
 753             s->init_num = 0;
 754             s->renegotiate = 0;
 755             s->new_session = 0;
 756
 757             ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
 758             if (s->hit)
 759                 s->ctx->stats.sess_hit++;
 760
 761             ret = 1;
 762             /* s->server=0; */
 763             s->handshake_func = dtls1_connect;
 764             s->ctx->stats.sess_connect_good++;
 765
 766             if (cb != NULL)
 767                 cb(s, SSL_CB_HANDSHAKE_DONE, 1);
 768
 769             /* done with handshaking */
 770             s->d1->handshake_read_seq = 0;
 771             s->d1->next_handshake_write_seq = 0;
 772             goto end;
 773             /* break; */
 774
 775         case SSL_ST_ERR:
 776         default:
 777             SSLerr(SSL_F_DTLS1_CONNECT, SSL_R_UNKNOWN_STATE);
 778             ret = -1;
 779             goto end;
 780             /* break; */
 781         }
 782
 783         /* did we do anything */
 784         if (!s->s3->tmp.reuse_message && !skip) {
 785             if (s->debug) {
 786                 if ((ret = BIO_flush(s->wbio)) <= 0)
 787                     goto end;
 788             }
 789
 790             if ((cb != NULL) && (s->state != state)) {
 791                 new_state = s->state;
 792                 s->state = state;
 793                 cb(s, SSL_CB_CONNECT_LOOP, 1);
 794                 s->state = new_state;
 795             }
 796         }
 797         skip = 0;
 798     }
 799  end:
 800     s->in_handshake--;
 801
 802 #ifndef OPENSSL_NO_SCTP
 803     /*
 804      * Notify SCTP BIO socket to leave handshake mode and allow stream
 805      * identifier other than 0. Will be ignored if no SCTP is used.
 806      */
 807     BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
 808              s->in_handshake, NULL);
 809 #endif
 810
 811     if (buf != NULL)
 812         BUF_MEM_free(buf);
 813     if (cb != NULL)
 814         cb(s, SSL_CB_CONNECT_EXIT, ret);
 815     return (ret);
 816 }
 817
 818 static int dtls1_get_hello_verify(SSL *s)
 819 {
 820     int n, al, ok = 0;
 821     unsigned char *data;
 822     unsigned int cookie_len;
 823
 824     s->first_packet = 1;
 825     n = s->method->ssl_get_message(s,
 826                                    DTLS1_ST_CR_HELLO_VERIFY_REQUEST_A,
 827                                    DTLS1_ST_CR_HELLO_VERIFY_REQUEST_B,
 828                                    -1, s->max_cert_list, &ok);
 829     s->first_packet = 0;
 830
 831     if (!ok)
 832         return ((int)n);
 833
 834     if (s->s3->tmp.message_type != DTLS1_MT_HELLO_VERIFY_REQUEST) {
 835         s->d1->send_cookie = 0;
 836         s->s3->tmp.reuse_message = 1;
 837         return (1);
 838     }
 839
 840     data = (unsigned char *)s->init_msg;
 841 #if 0
 842     if (s->method->version != DTLS_ANY_VERSION &&
 843         ((data[0] != (s->version >> 8)) || (data[1] != (s->version & 0xff))))
 844     {
 845         SSLerr(SSL_F_DTLS1_GET_HELLO_VERIFY, SSL_R_WRONG_SSL_VERSION);
 846         s->version = (s->version & 0xff00) | data[1];
 847         al = SSL_AD_PROTOCOL_VERSION;
 848         goto f_err;
 849     }
 850 #endif
 851     data += 2;
 852
 853     cookie_len = *(data++);
 854     if (cookie_len > sizeof(s->d1->cookie)) {
 855         al = SSL_AD_ILLEGAL_PARAMETER;
 856         goto f_err;
 857     }
 858
 859     memcpy(s->d1->cookie, data, cookie_len);
 860     s->d1->cookie_len = cookie_len;
 861
 862     s->d1->send_cookie = 1;
 863     return 1;
 864
 865  f_err:
 866     ssl3_send_alert(s, SSL3_AL_FATAL, al);
 867     s->state = SSL_ST_ERR;
 868     return -1;
 869 }