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, DTLSv1_enc_data)
 147
 148     IMPLEMENT_dtls1_meth_func(DTLS1_2_VERSION,
 149                           DTLSv1_2_server_method,
 150                           dtls1_accept,
 151                           ssl_undefined_function,
 152                           dtls1_get_server_method, DTLSv1_2_enc_data)
 153
 154     IMPLEMENT_dtls1_meth_func(DTLS_ANY_VERSION,
 155                           DTLS_server_method,
 156                           dtls1_accept,
 157                           ssl_undefined_function,
 158                           dtls1_get_server_method, DTLSv1_2_enc_data)
 159
 160 int dtls1_accept(SSL *s)
 161 {
 162     BUF_MEM *buf;
 163     unsigned long Time = (unsigned long)time(NULL);
 164     void (*cb) (const SSL *ssl, int type, int val) = NULL;
 165     unsigned long alg_k;
 166     int ret = -1;
 167     int new_state, state, skip = 0;
 168 #ifndef OPENSSL_NO_SCTP
 169     unsigned char sctpauthkey[64];
 170     char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
 171 #endif
 172
 173     RAND_add(&Time, sizeof(Time), 0);
 174     ERR_clear_error();
 175     clear_sys_error();
 176
 177     if (s->info_callback != NULL)
 178         cb = s->info_callback;
 179     else if (s->ctx->info_callback != NULL)
 180         cb = s->ctx->info_callback;
 181
 182     /* init things to blank */
 183     s->in_handshake++;
 184     if (!SSL_in_init(s) || SSL_in_before(s)) {
 185         if (!SSL_clear(s))
 186             return -1;
 187     }
 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_ACCEPT; */
 218
 219         case SSL_ST_BEFORE:
 220         case SSL_ST_ACCEPT:
 221         case SSL_ST_BEFORE | SSL_ST_ACCEPT:
 222         case SSL_ST_OK | SSL_ST_ACCEPT:
 223
 224             s->server = 1;
 225             if (cb != NULL)
 226                 cb(s, SSL_CB_HANDSHAKE_START, 1);
 227
 228             if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
 229                 SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 230                 return -1;
 231             }
 232             s->type = SSL_ST_ACCEPT;
 233
 234             if (s->init_buf == NULL) {
 235                 if ((buf = BUF_MEM_new()) == NULL) {
 236                     ret = -1;
 237                     s->state = SSL_ST_ERR;
 238                     goto end;
 239                 }
 240                 if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
 241                     BUF_MEM_free(buf);
 242                     ret = -1;
 243                     s->state = SSL_ST_ERR;
 244                     goto end;
 245                 }
 246                 s->init_buf = buf;
 247             }
 248
 249             if (!ssl3_setup_buffers(s)) {
 250                 ret = -1;
 251                 s->state = SSL_ST_ERR;
 252                 goto end;
 253             }
 254
 255             s->init_num = 0;
 256             /*
 257              * Should have been reset by ssl3_get_finished, too.
 258              */
 259             s->s3->change_cipher_spec = 0;
 260
 261             if (s->state != SSL_ST_RENEGOTIATE) {
 262                 /*
 263                  * Ok, we now need to push on a buffering BIO so that the
 264                  * output is sent in a way that TCP likes :-) ...but not with
 265                  * SCTP :-)
 266                  */
 267 #ifndef OPENSSL_NO_SCTP
 268                 if (!BIO_dgram_is_sctp(SSL_get_wbio(s)))
 269 #endif
 270                     if (!ssl_init_wbio_buffer(s, 1)) {
 271                         ret = -1;
 272                         s->state = SSL_ST_ERR;
 273                         goto end;
 274                     }
 275
 276                 ssl3_init_finished_mac(s);
 277                 s->state = SSL3_ST_SR_CLNT_HELLO_A;
 278                 s->ctx->stats.sess_accept++;
 279             } else {
 280                 /*
 281                  * s->state == SSL_ST_RENEGOTIATE, we will just send a
 282                  * HelloRequest
 283                  */
 284                 s->ctx->stats.sess_accept_renegotiate++;
 285                 s->state = SSL3_ST_SW_HELLO_REQ_A;
 286             }
 287
 288             break;
 289
 290         case SSL3_ST_SW_HELLO_REQ_A:
 291         case SSL3_ST_SW_HELLO_REQ_B:
 292
 293             s->shutdown = 0;
 294             dtls1_clear_record_buffer(s);
 295             dtls1_start_timer(s);
 296             ret = ssl3_send_hello_request(s);
 297             if (ret <= 0)
 298                 goto end;
 299             s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
 300             s->state = SSL3_ST_SW_FLUSH;
 301             s->init_num = 0;
 302
 303             ssl3_init_finished_mac(s);
 304             break;
 305
 306         case SSL3_ST_SW_HELLO_REQ_C:
 307             s->state = SSL_ST_OK;
 308             break;
 309
 310         case SSL3_ST_SR_CLNT_HELLO_A:
 311         case SSL3_ST_SR_CLNT_HELLO_B:
 312         case SSL3_ST_SR_CLNT_HELLO_C:
 313
 314             s->shutdown = 0;
 315             ret = ssl3_get_client_hello(s);
 316             if (ret <= 0)
 317                 goto end;
 318             dtls1_stop_timer(s);
 319
 320             if (ret == 1 && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
 321                 s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
 322             else
 323                 s->state = SSL3_ST_SW_SRVR_HELLO_A;
 324
 325             s->init_num = 0;
 326             break;
 327
 328         case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
 329         case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
 330
 331             ret = dtls1_send_hello_verify_request(s);
 332             if (ret <= 0)
 333                 goto end;
 334             s->state = SSL3_ST_SW_FLUSH;
 335             s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
 336
 337             /* HelloVerifyRequest resets Finished MAC */
 338             if (s->version != DTLS1_BAD_VER)
 339                 ssl3_init_finished_mac(s);
 340             break;
 341
 342 #ifndef OPENSSL_NO_SCTP
 343         case DTLS1_SCTP_ST_SR_READ_SOCK:
 344
 345             if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
 346                 s->s3->in_read_app_data = 2;
 347                 s->rwstate = SSL_READING;
 348                 BIO_clear_retry_flags(SSL_get_rbio(s));
 349                 BIO_set_retry_read(SSL_get_rbio(s));
 350                 ret = -1;
 351                 goto end;
 352             }
 353
 354             s->state = SSL3_ST_SR_CHANGE_A;
 355             break;
 356
 357         case DTLS1_SCTP_ST_SW_WRITE_SOCK:
 358             ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
 359             if (ret < 0)
 360                 goto end;
 361
 362             if (ret == 0) {
 363                 if (s->d1->next_state != SSL_ST_OK) {
 364                     s->s3->in_read_app_data = 2;
 365                     s->rwstate = SSL_READING;
 366                     BIO_clear_retry_flags(SSL_get_rbio(s));
 367                     BIO_set_retry_read(SSL_get_rbio(s));
 368                     ret = -1;
 369                     goto end;
 370                 }
 371             }
 372
 373             s->state = s->d1->next_state;
 374             break;
 375 #endif
 376
 377         case SSL3_ST_SW_SRVR_HELLO_A:
 378         case SSL3_ST_SW_SRVR_HELLO_B:
 379             s->renegotiate = 2;
 380             dtls1_start_timer(s);
 381             ret = ssl3_send_server_hello(s);
 382             if (ret <= 0)
 383                 goto end;
 384
 385             if (s->hit) {
 386 #ifndef OPENSSL_NO_SCTP
 387                 /*
 388                  * Add new shared key for SCTP-Auth, will be ignored if no
 389                  * SCTP used.
 390                  */
 391                 snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 392                          DTLS1_SCTP_AUTH_LABEL);
 393
 394                 if (SSL_export_keying_material(s, sctpauthkey,
 395                         sizeof(sctpauthkey), labelbuffer,
 396                         sizeof(labelbuffer), NULL, 0, 0) <= 0) {
 397                     ret = -1;
 398                     s->state = SSL_ST_ERR;
 399                     goto end;
 400                 }
 401
 402                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 403                          sizeof(sctpauthkey), sctpauthkey);
 404 #endif
 405                 if (s->tlsext_ticket_expected)
 406                     s->state = SSL3_ST_SW_SESSION_TICKET_A;
 407                 else
 408                     s->state = SSL3_ST_SW_CHANGE_A;
 409             } else
 410                 s->state = SSL3_ST_SW_CERT_A;
 411             s->init_num = 0;
 412             break;
 413
 414         case SSL3_ST_SW_CERT_A:
 415         case SSL3_ST_SW_CERT_B:
 416             /* Check if it is anon DH or normal PSK */
 417             if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
 418                 && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
 419                 dtls1_start_timer(s);
 420                 ret = ssl3_send_server_certificate(s);
 421                 if (ret <= 0)
 422                     goto end;
 423
 424                 if (s->tlsext_status_expected)
 425                     s->state = SSL3_ST_SW_CERT_STATUS_A;
 426                 else
 427                     s->state = SSL3_ST_SW_KEY_EXCH_A;
 428             } else {
 429                 skip = 1;
 430                 s->state = SSL3_ST_SW_KEY_EXCH_A;
 431             }
 432             s->init_num = 0;
 433             break;
 434
 435         case SSL3_ST_SW_KEY_EXCH_A:
 436         case SSL3_ST_SW_KEY_EXCH_B:
 437             alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
 438
 439             /*
 440              * clear this, it may get reset by
 441              * send_server_key_exchange
 442              */
 443             s->s3->tmp.use_rsa_tmp = 0;
 444
 445             /*
 446              * only send if a DH key exchange or RSA but we have a sign only
 447              * certificate
 448              */
 449             if (0
 450                 /*
 451                  * PSK: send ServerKeyExchange if PSK identity hint if
 452                  * provided
 453                  */
 454 #ifndef OPENSSL_NO_PSK
 455                 || ((alg_k & SSL_kPSK) && s->cert->psk_identity_hint)
 456 #endif
 457                 || (alg_k & SSL_kDHE)
 458                 || (alg_k & SSL_kECDHE)
 459                 || ((alg_k & SSL_kRSA)
 460                     && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
 461                         || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
 462                             && EVP_PKEY_size(s->cert->pkeys
 463                                              [SSL_PKEY_RSA_ENC].privatekey) *
 464                             8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
 465                         )
 466                     )
 467                 )
 468                 ) {
 469                 dtls1_start_timer(s);
 470                 ret = ssl3_send_server_key_exchange(s);
 471                 if (ret <= 0)
 472                     goto end;
 473             } else
 474                 skip = 1;
 475
 476             s->state = SSL3_ST_SW_CERT_REQ_A;
 477             s->init_num = 0;
 478             break;
 479
 480         case SSL3_ST_SW_CERT_REQ_A:
 481         case SSL3_ST_SW_CERT_REQ_B:
 482             if (                /* don't request cert unless asked for it: */
 483                    !(s->verify_mode & SSL_VERIFY_PEER) ||
 484                    /*
 485                     * if SSL_VERIFY_CLIENT_ONCE is set, don't request cert
 486                     * during re-negotiation:
 487                     */
 488                    ((s->session->peer != NULL) &&
 489                     (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
 490                    /*
 491                     * never request cert in anonymous ciphersuites (see
 492                     * section "Certificate request" in SSL 3 drafts and in
 493                     * RFC 2246):
 494                     */
 495                    ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
 496                    /*
 497                     * ... except when the application insists on
 498                     * verification (against the specs, but s3_clnt.c accepts
 499                     * this for SSL 3)
 500                     */
 501                    !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT))
 502                    /*
 503                     * With normal PSK Certificates and Certificate Requests
 504                     * are omitted
 505                     */
 506                    || (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
 507                 /* no cert request */
 508                 skip = 1;
 509                 s->s3->tmp.cert_request = 0;
 510                 s->state = SSL3_ST_SW_SRVR_DONE_A;
 511 #ifndef OPENSSL_NO_SCTP
 512                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 513                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 514                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 515                 }
 516 #endif
 517             } else {
 518                 s->s3->tmp.cert_request = 1;
 519                 dtls1_start_timer(s);
 520                 ret = ssl3_send_certificate_request(s);
 521                 if (ret <= 0)
 522                     goto end;
 523                 s->state = SSL3_ST_SW_SRVR_DONE_A;
 524 # ifndef OPENSSL_NO_SCTP
 525                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 526                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 527                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 528                 }
 529 # endif
 530                 s->init_num = 0;
 531             }
 532             break;
 533
 534         case SSL3_ST_SW_SRVR_DONE_A:
 535         case SSL3_ST_SW_SRVR_DONE_B:
 536             dtls1_start_timer(s);
 537             ret = ssl3_send_server_done(s);
 538             if (ret <= 0)
 539                 goto end;
 540             s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
 541             s->state = SSL3_ST_SW_FLUSH;
 542             s->init_num = 0;
 543             break;
 544
 545         case SSL3_ST_SW_FLUSH:
 546             s->rwstate = SSL_WRITING;
 547             if (BIO_flush(s->wbio) <= 0) {
 548                 /*
 549                  * If the write error was fatal, stop trying
 550                  */
 551                 if (!BIO_should_retry(s->wbio)) {
 552                     s->rwstate = SSL_NOTHING;
 553                     s->state = s->s3->tmp.next_state;
 554                 }
 555
 556                 ret = -1;
 557                 goto end;
 558             }
 559             s->rwstate = SSL_NOTHING;
 560             s->state = s->s3->tmp.next_state;
 561             break;
 562
 563         case SSL3_ST_SR_CERT_A:
 564         case SSL3_ST_SR_CERT_B:
 565             if (s->s3->tmp.cert_request) {
 566                 ret = ssl3_get_client_certificate(s);
 567                 if (ret <= 0)
 568                     goto end;
 569             }
 570             s->init_num = 0;
 571             s->state = SSL3_ST_SR_KEY_EXCH_A;
 572             break;
 573
 574         case SSL3_ST_SR_KEY_EXCH_A:
 575         case SSL3_ST_SR_KEY_EXCH_B:
 576             ret = ssl3_get_client_key_exchange(s);
 577             if (ret <= 0)
 578                 goto end;
 579 #ifndef OPENSSL_NO_SCTP
 580             /*
 581              * Add new shared key for SCTP-Auth, will be ignored if no SCTP
 582              * used.
 583              */
 584             snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 585                      DTLS1_SCTP_AUTH_LABEL);
 586
 587             if (SSL_export_keying_material(s, sctpauthkey,
 588                                        sizeof(sctpauthkey), labelbuffer,
 589                                        sizeof(labelbuffer), NULL, 0, 0) <= 0) {
 590                 ret = -1;
 591                 s->state = SSL_ST_ERR;
 592                 goto end;
 593             }
 594
 595             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 596                      sizeof(sctpauthkey), sctpauthkey);
 597 #endif
 598
 599             s->state = SSL3_ST_SR_CERT_VRFY_A;
 600             s->init_num = 0;
 601
 602             if (ret == 2) {
 603                 /*
 604                  * For the ECDH ciphersuites when the client sends its ECDH
 605                  * pub key in a certificate, the CertificateVerify message is
 606                  * not sent.
 607                  */
 608                 s->state = SSL3_ST_SR_CHANGE_A;
 609                 s->init_num = 0;
 610             } else if (SSL_USE_SIGALGS(s)) {
 611                 s->state = SSL3_ST_SR_CERT_VRFY_A;
 612                 s->init_num = 0;
 613                 if (!s->session->peer)
 614                     break;
 615                 if (!s->s3->handshake_buffer) {
 616                     SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 617                     s->state = SSL_ST_ERR;
 618                     return -1;
 619                 }
 620                 /*
 621                  * For sigalgs freeze the handshake buffer. If we support
 622                  * extms we've done this already.
 623                  */
 624                 if (!ssl3_digest_cached_records(s, 1)) {
 625                     s->state = SSL_ST_ERR;
 626                     return -1;
 627                 }
 628             } else {
 629                 s->state = SSL3_ST_SR_CERT_VRFY_A;
 630                 s->init_num = 0;
 631
 632                 /*
 633                  * We need to get hashes here so if there is a client cert,
 634                  * it can be verified
 635                  */
 636                 s->method->ssl3_enc->cert_verify_mac(s,
 637                                                      NID_md5,
 638                                                      &(s->s3->
 639                                                        tmp.cert_verify_md
 640                                                        [0]));
 641                 s->method->ssl3_enc->cert_verify_mac(s, NID_sha1,
 642                                                      &(s->s3->
 643                                                        tmp.cert_verify_md
 644                                                        [MD5_DIGEST_LENGTH]));
 645             }
 646             break;
 647
 648         case SSL3_ST_SR_CERT_VRFY_A:
 649         case SSL3_ST_SR_CERT_VRFY_B:
 650             ret = ssl3_get_cert_verify(s);
 651             if (ret <= 0)
 652                 goto end;
 653 #ifndef OPENSSL_NO_SCTP
 654             if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
 655                 state == SSL_ST_RENEGOTIATE)
 656                 s->state = DTLS1_SCTP_ST_SR_READ_SOCK;
 657             else
 658 #endif
 659                 s->state = SSL3_ST_SR_CHANGE_A;
 660             s->init_num = 0;
 661             break;
 662
 663         case SSL3_ST_SR_CHANGE_A:
 664         case SSL3_ST_SR_CHANGE_B:
 665             ret = ssl3_get_change_cipher_spec(s, SSL3_ST_SR_CHANGE_A,
 666                                               SSL3_ST_SR_CHANGE_B);
 667             if (ret <= 0)
 668                 goto end;
 669
 670             s->state = SSL3_ST_SR_FINISHED_A;
 671             s->init_num = 0;
 672             break;
 673
 674         case SSL3_ST_SR_FINISHED_A:
 675         case SSL3_ST_SR_FINISHED_B:
 676             ret = ssl3_get_finished(s, SSL3_ST_SR_FINISHED_A,
 677                                     SSL3_ST_SR_FINISHED_B);
 678             if (ret <= 0)
 679                 goto end;
 680             dtls1_stop_timer(s);
 681             if (s->hit)
 682                 s->state = SSL_ST_OK;
 683             else if (s->tlsext_ticket_expected)
 684                 s->state = SSL3_ST_SW_SESSION_TICKET_A;
 685             else
 686                 s->state = SSL3_ST_SW_CHANGE_A;
 687             s->init_num = 0;
 688             break;
 689
 690         case SSL3_ST_SW_SESSION_TICKET_A:
 691         case SSL3_ST_SW_SESSION_TICKET_B:
 692             ret = ssl3_send_newsession_ticket(s);
 693             if (ret <= 0)
 694                 goto end;
 695             s->state = SSL3_ST_SW_CHANGE_A;
 696             s->init_num = 0;
 697             break;
 698
 699         case SSL3_ST_SW_CERT_STATUS_A:
 700         case SSL3_ST_SW_CERT_STATUS_B:
 701             ret = ssl3_send_cert_status(s);
 702             if (ret <= 0)
 703                 goto end;
 704             s->state = SSL3_ST_SW_KEY_EXCH_A;
 705             s->init_num = 0;
 706             break;
 707
 708         case SSL3_ST_SW_CHANGE_A:
 709         case SSL3_ST_SW_CHANGE_B:
 710
 711             s->session->cipher = s->s3->tmp.new_cipher;
 712             if (!s->method->ssl3_enc->setup_key_block(s)) {
 713                 ret = -1;
 714                 s->state = SSL_ST_ERR;
 715                 goto end;
 716             }
 717
 718             ret = dtls1_send_change_cipher_spec(s,
 719                                                 SSL3_ST_SW_CHANGE_A,
 720                                                 SSL3_ST_SW_CHANGE_B);
 721
 722             if (ret <= 0)
 723                 goto end;
 724
 725 #ifndef OPENSSL_NO_SCTP
 726             if (!s->hit) {
 727                 /*
 728                  * Change to new shared key of SCTP-Auth, will be ignored if
 729                  * no SCTP used.
 730                  */
 731                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 732                          0, NULL);
 733             }
 734 #endif
 735
 736             s->state = SSL3_ST_SW_FINISHED_A;
 737             s->init_num = 0;
 738
 739             if (!s->method->ssl3_enc->change_cipher_state(s,
 740                                                           SSL3_CHANGE_CIPHER_SERVER_WRITE))
 741             {
 742                 ret = -1;
 743                 s->state = SSL_ST_ERR;
 744                 goto end;
 745             }
 746
 747             dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
 748             break;
 749
 750         case SSL3_ST_SW_FINISHED_A:
 751         case SSL3_ST_SW_FINISHED_B:
 752             ret = ssl3_send_finished(s,
 753                                      SSL3_ST_SW_FINISHED_A,
 754                                      SSL3_ST_SW_FINISHED_B,
 755                                      s->method->
 756                                      ssl3_enc->server_finished_label,
 757                                      s->method->
 758                                      ssl3_enc->server_finished_label_len);
 759             if (ret <= 0)
 760                 goto end;
 761             s->state = SSL3_ST_SW_FLUSH;
 762             if (s->hit) {
 763                 s->s3->tmp.next_state = SSL3_ST_SR_CHANGE_A;
 764
 765 #ifndef OPENSSL_NO_SCTP
 766                 /*
 767                  * Change to new shared key of SCTP-Auth, will be ignored if
 768                  * no SCTP used.
 769                  */
 770                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 771                          0, NULL);
 772 #endif
 773             } else {
 774                 s->s3->tmp.next_state = SSL_ST_OK;
 775 #ifndef OPENSSL_NO_SCTP
 776                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 777                     s->d1->next_state = s->s3->tmp.next_state;
 778                     s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 779                 }
 780 #endif
 781             }
 782             s->init_num = 0;
 783             break;
 784
 785         case SSL_ST_OK:
 786             /* clean a few things up */
 787             ssl3_cleanup_key_block(s);
 788
 789             /* remove buffering on output */
 790             ssl_free_wbio_buffer(s);
 791
 792             s->init_num = 0;
 793
 794             if (s->renegotiate == 2) { /* skipped if we just sent a
 795                                         * HelloRequest */
 796                 s->renegotiate = 0;
 797                 s->new_session = 0;
 798
 799                 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
 800
 801                 s->ctx->stats.sess_accept_good++;
 802                 /* s->server=1; */
 803                 s->handshake_func = dtls1_accept;
 804
 805                 if (cb != NULL)
 806                     cb(s, SSL_CB_HANDSHAKE_DONE, 1);
 807             }
 808
 809             ret = 1;
 810
 811             /* done handshaking, next message is client hello */
 812             s->d1->handshake_read_seq = 0;
 813             /* next message is server hello */
 814             s->d1->handshake_write_seq = 0;
 815             s->d1->next_handshake_write_seq = 0;
 816             goto end;
 817             /* break; */
 818
 819         case SSL_ST_ERR:
 820         default:
 821             SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_UNKNOWN_STATE);
 822             ret = -1;
 823             goto end;
 824             /* break; */
 825         }
 826
 827         if (!s->s3->tmp.reuse_message && !skip) {
 828             if (s->debug) {
 829                 if ((ret = BIO_flush(s->wbio)) <= 0)
 830                     goto end;
 831             }
 832
 833             if ((cb != NULL) && (s->state != state)) {
 834                 new_state = s->state;
 835                 s->state = state;
 836                 cb(s, SSL_CB_ACCEPT_LOOP, 1);
 837                 s->state = new_state;
 838             }
 839         }
 840         skip = 0;
 841     }
 842  end:
 843     /* BIO_flush(s->wbio); */
 844
 845     s->in_handshake--;
 846 #ifndef OPENSSL_NO_SCTP
 847     /*
 848      * Notify SCTP BIO socket to leave handshake mode and prevent stream
 849      * identifier other than 0. Will be ignored if no SCTP is used.
 850      */
 851     BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
 852              s->in_handshake, NULL);
 853 #endif
 854
 855     if (cb != NULL)
 856         cb(s, SSL_CB_ACCEPT_EXIT, ret);
 857     return (ret);
 858 }
 859
 860 unsigned int dtls1_raw_hello_verify_request(unsigned char *buf,
 861                                             unsigned char *cookie,
 862                                             unsigned char cookie_len)
 863 {
 864     unsigned int msg_len;
 865     unsigned char *p;
 866
 867     p = buf;
 868     /* Always use DTLS 1.0 version: see RFC 6347 */
 869     *(p++) = DTLS1_VERSION >> 8;
 870     *(p++) = DTLS1_VERSION & 0xFF;
 871
 872     *(p++) = (unsigned char)cookie_len;
 873     memcpy(p, cookie, cookie_len);
 874     p += cookie_len;
 875     msg_len = p - buf;
 876
 877     return msg_len;
 878 }
 879
 880
 881 int dtls1_send_hello_verify_request(SSL *s)
 882 {
 883     unsigned int len;
 884     unsigned char *buf;
 885
 886     if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) {
 887         buf = (unsigned char *)s->init_buf->data;
 888
 889         if (s->ctx->app_gen_cookie_cb == NULL ||
 890             s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
 891                                       &(s->d1->cookie_len)) == 0) {
 892             SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,
 893                    ERR_R_INTERNAL_ERROR);
 894             s->state = SSL_ST_ERR;
 895             return 0;
 896         }
 897
 898         len = dtls1_raw_hello_verify_request(&buf[DTLS1_HM_HEADER_LENGTH],
 899                                              s->d1->cookie, s->d1->cookie_len);
 900
 901         dtls1_set_message_header(s, buf, DTLS1_MT_HELLO_VERIFY_REQUEST, len, 0,
 902                                  len);
 903         len += DTLS1_HM_HEADER_LENGTH;
 904
 905         s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
 906         /* number of bytes to write */
 907         s->init_num = len;
 908         s->init_off = 0;
 909     }
 910
 911     /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
 912     return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
 913 }