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
 131 static const SSL_METHOD *dtls1_get_server_method(int ver)
 132 {
 133     if (ver == DTLS1_VERSION)
 134         return (DTLSv1_server_method());
 135     else if (ver == DTLS1_2_VERSION)
 136         return (DTLSv1_2_server_method());
 137     else
 138         return (NULL);
 139 }
 140
 141 IMPLEMENT_dtls1_meth_func(DTLS1_VERSION,
 142                           DTLSv1_server_method,
 143                           dtls1_accept,
 144                           ssl_undefined_function,
 145                           dtls1_get_server_method, DTLSv1_enc_data)
 146
 147     IMPLEMENT_dtls1_meth_func(DTLS1_2_VERSION,
 148                           DTLSv1_2_server_method,
 149                           dtls1_accept,
 150                           ssl_undefined_function,
 151                           dtls1_get_server_method, DTLSv1_2_enc_data)
 152
 153     IMPLEMENT_dtls1_meth_func(DTLS_ANY_VERSION,
 154                           DTLS_server_method,
 155                           dtls1_accept,
 156                           ssl_undefined_function,
 157                           dtls1_get_server_method, DTLSv1_2_enc_data)
 158
 159 #if 0
 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 (!s->d1->cookie_verified
 321                     && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
 322                 s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
 323             else
 324                 s->state = SSL3_ST_SW_SRVR_HELLO_A;
 325
 326             s->init_num = 0;
 327             break;
 328
 329         case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
 330         case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
 331
 332             ret = dtls1_send_hello_verify_request(s);
 333             if (ret <= 0)
 334                 goto end;
 335             s->state = SSL3_ST_SW_FLUSH;
 336             s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
 337
 338             /* HelloVerifyRequest resets Finished MAC */
 339             if (s->version != DTLS1_BAD_VER)
 340                 ssl3_init_finished_mac(s);
 341             break;
 342
 343 #ifndef OPENSSL_NO_SCTP
 344         case DTLS1_SCTP_ST_SR_READ_SOCK:
 345
 346             if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
 347                 s->s3->in_read_app_data = 2;
 348                 s->rwstate = SSL_READING;
 349                 BIO_clear_retry_flags(SSL_get_rbio(s));
 350                 BIO_set_retry_read(SSL_get_rbio(s));
 351                 ret = -1;
 352                 goto end;
 353             }
 354
 355             s->state = SSL3_ST_SR_CHANGE_A;
 356             break;
 357
 358         case DTLS1_SCTP_ST_SW_WRITE_SOCK:
 359             ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
 360             if (ret < 0)
 361                 goto end;
 362
 363             if (ret == 0) {
 364                 if (s->d1->next_state != SSL_ST_OK) {
 365                     s->s3->in_read_app_data = 2;
 366                     s->rwstate = SSL_READING;
 367                     BIO_clear_retry_flags(SSL_get_rbio(s));
 368                     BIO_set_retry_read(SSL_get_rbio(s));
 369                     ret = -1;
 370                     goto end;
 371                 }
 372             }
 373
 374             s->state = s->d1->next_state;
 375             break;
 376 #endif
 377
 378         case SSL3_ST_SW_SRVR_HELLO_A:
 379         case SSL3_ST_SW_SRVR_HELLO_B:
 380             s->renegotiate = 2;
 381             dtls1_start_timer(s);
 382             ret = ssl3_send_server_hello(s);
 383             if (ret <= 0)
 384                 goto end;
 385
 386             if (s->hit) {
 387 #ifndef OPENSSL_NO_SCTP
 388                 /*
 389                  * Add new shared key for SCTP-Auth, will be ignored if no
 390                  * SCTP used.
 391                  */
 392                 snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 393                          DTLS1_SCTP_AUTH_LABEL);
 394
 395                 if (SSL_export_keying_material(s, sctpauthkey,
 396                         sizeof(sctpauthkey), labelbuffer,
 397                         sizeof(labelbuffer), NULL, 0, 0) <= 0) {
 398                     ret = -1;
 399                     s->state = SSL_ST_ERR;
 400                     goto end;
 401                 }
 402
 403                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 404                          sizeof(sctpauthkey), sctpauthkey);
 405 #endif
 406                 if (s->tlsext_ticket_expected)
 407                     s->state = SSL3_ST_SW_SESSION_TICKET_A;
 408                 else
 409                     s->state = SSL3_ST_SW_CHANGE_A;
 410             } else
 411                 s->state = SSL3_ST_SW_CERT_A;
 412             s->init_num = 0;
 413             break;
 414
 415         case SSL3_ST_SW_CERT_A:
 416         case SSL3_ST_SW_CERT_B:
 417             /* Check if it is anon DH or normal PSK */
 418             if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
 419                 && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
 420                 dtls1_start_timer(s);
 421                 ret = ssl3_send_server_certificate(s);
 422                 if (ret <= 0)
 423                     goto end;
 424
 425                 if (s->tlsext_status_expected)
 426                     s->state = SSL3_ST_SW_CERT_STATUS_A;
 427                 else
 428                     s->state = SSL3_ST_SW_KEY_EXCH_A;
 429             } else {
 430                 skip = 1;
 431                 s->state = SSL3_ST_SW_KEY_EXCH_A;
 432             }
 433             s->init_num = 0;
 434             break;
 435
 436         case SSL3_ST_SW_KEY_EXCH_A:
 437         case SSL3_ST_SW_KEY_EXCH_B:
 438             alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
 439
 440             /*
 441              * clear this, it may get reset by
 442              * send_server_key_exchange
 443              */
 444             s->s3->tmp.use_rsa_tmp = 0;
 445
 446             /*
 447              * only send if a DH key exchange or RSA but we have a sign only
 448              * certificate
 449              */
 450             if (0
 451                 /*
 452                  * PSK: send ServerKeyExchange if PSK identity hint if
 453                  * provided
 454                  */
 455 #ifndef OPENSSL_NO_PSK
 456                 || ((alg_k & SSL_kPSK) && s->cert->psk_identity_hint)
 457 #endif
 458                 || (alg_k & SSL_kDHE)
 459                 || (alg_k & SSL_kECDHE)
 460                 || ((alg_k & SSL_kRSA)
 461                     && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
 462                         || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
 463                             && EVP_PKEY_size(s->cert->pkeys
 464                                              [SSL_PKEY_RSA_ENC].privatekey) *
 465                             8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
 466                         )
 467                     )
 468                 )
 469                 ) {
 470                 dtls1_start_timer(s);
 471                 ret = ssl3_send_server_key_exchange(s);
 472                 if (ret <= 0)
 473                     goto end;
 474             } else
 475                 skip = 1;
 476
 477             s->state = SSL3_ST_SW_CERT_REQ_A;
 478             s->init_num = 0;
 479             break;
 480
 481         case SSL3_ST_SW_CERT_REQ_A:
 482         case SSL3_ST_SW_CERT_REQ_B:
 483             if (                /* don't request cert unless asked for it: */
 484                    !(s->verify_mode & SSL_VERIFY_PEER) ||
 485                    /*
 486                     * if SSL_VERIFY_CLIENT_ONCE is set, don't request cert
 487                     * during re-negotiation:
 488                     */
 489                    ((s->session->peer != NULL) &&
 490                     (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
 491                    /*
 492                     * never request cert in anonymous ciphersuites (see
 493                     * section "Certificate request" in SSL 3 drafts and in
 494                     * RFC 2246):
 495                     */
 496                    ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
 497                    /*
 498                     * ... except when the application insists on
 499                     * verification (against the specs, but s3_clnt.c accepts
 500                     * this for SSL 3)
 501                     */
 502                    !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT))
 503                    /*
 504                     * With normal PSK Certificates and Certificate Requests
 505                     * are omitted
 506                     */
 507                    || (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
 508                 /* no cert request */
 509                 skip = 1;
 510                 s->s3->tmp.cert_request = 0;
 511                 s->state = SSL3_ST_SW_SRVR_DONE_A;
 512 #ifndef OPENSSL_NO_SCTP
 513                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 514                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 515                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 516                 }
 517 #endif
 518             } else {
 519                 s->s3->tmp.cert_request = 1;
 520                 dtls1_start_timer(s);
 521                 ret = ssl3_send_certificate_request(s);
 522                 if (ret <= 0)
 523                     goto end;
 524                 s->state = SSL3_ST_SW_SRVR_DONE_A;
 525 # ifndef OPENSSL_NO_SCTP
 526                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 527                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 528                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 529                 }
 530 # endif
 531                 s->init_num = 0;
 532             }
 533             break;
 534
 535         case SSL3_ST_SW_SRVR_DONE_A:
 536         case SSL3_ST_SW_SRVR_DONE_B:
 537             dtls1_start_timer(s);
 538             ret = ssl3_send_server_done(s);
 539             if (ret <= 0)
 540                 goto end;
 541             s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
 542             s->state = SSL3_ST_SW_FLUSH;
 543             s->init_num = 0;
 544             break;
 545
 546         case SSL3_ST_SW_FLUSH:
 547             s->rwstate = SSL_WRITING;
 548             if (BIO_flush(s->wbio) <= 0) {
 549                 /*
 550                  * If the write error was fatal, stop trying
 551                  */
 552                 if (!BIO_should_retry(s->wbio)) {
 553                     s->rwstate = SSL_NOTHING;
 554                     s->state = s->s3->tmp.next_state;
 555                 }
 556
 557                 ret = -1;
 558                 goto end;
 559             }
 560             s->rwstate = SSL_NOTHING;
 561             s->state = s->s3->tmp.next_state;
 562             break;
 563
 564         case SSL3_ST_SR_CERT_A:
 565         case SSL3_ST_SR_CERT_B:
 566             if (s->s3->tmp.cert_request) {
 567                 ret = ssl3_get_client_certificate(s);
 568                 if (ret <= 0)
 569                     goto end;
 570             }
 571             s->init_num = 0;
 572             s->state = SSL3_ST_SR_KEY_EXCH_A;
 573             break;
 574
 575         case SSL3_ST_SR_KEY_EXCH_A:
 576         case SSL3_ST_SR_KEY_EXCH_B:
 577             ret = ssl3_get_client_key_exchange(s);
 578             if (ret <= 0)
 579                 goto end;
 580 #ifndef OPENSSL_NO_SCTP
 581             /*
 582              * Add new shared key for SCTP-Auth, will be ignored if no SCTP
 583              * used.
 584              */
 585             snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 586                      DTLS1_SCTP_AUTH_LABEL);
 587
 588             if (SSL_export_keying_material(s, sctpauthkey,
 589                                        sizeof(sctpauthkey), labelbuffer,
 590                                        sizeof(labelbuffer), NULL, 0, 0) <= 0) {
 591                 ret = -1;
 592                 s->state = SSL_ST_ERR;
 593                 goto end;
 594             }
 595
 596             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 597                      sizeof(sctpauthkey), sctpauthkey);
 598 #endif
 599
 600             s->state = SSL3_ST_SR_CERT_VRFY_A;
 601             s->init_num = 0;
 602
 603             if (s->no_cert_verify) {
 604                 /*
 605                  * For the ECDH ciphersuites when the client sends its ECDH
 606                  * pub key in a certificate, the CertificateVerify message is
 607                  * not sent.
 608                  */
 609                 s->state = SSL3_ST_SR_CHANGE_A;
 610                 s->init_num = 0;
 611             } else if (SSL_USE_SIGALGS(s)) {
 612                 s->state = SSL3_ST_SR_CERT_VRFY_A;
 613                 s->init_num = 0;
 614                 if (!s->session->peer)
 615                     break;
 616                 if (!s->s3->handshake_buffer) {
 617                     SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 618                     s->state = SSL_ST_ERR;
 619                     return -1;
 620                 }
 621                 /*
 622                  * For sigalgs freeze the handshake buffer. If we support
 623                  * extms we've done this already.
 624                  */
 625                 if (!ssl3_digest_cached_records(s, 1)) {
 626                     s->state = SSL_ST_ERR;
 627                     return -1;
 628                 }
 629             } else {
 630                 s->state = SSL3_ST_SR_CERT_VRFY_A;
 631                 s->init_num = 0;
 632
 633                 /*
 634                  * We need to get hashes here so if there is a client cert,
 635                  * it can be verified
 636                  */
 637                 s->method->ssl3_enc->cert_verify_mac(s,
 638                                                      NID_md5,
 639                                                      &(s->s3->
 640                                                        tmp.cert_verify_md
 641                                                        [0]));
 642                 s->method->ssl3_enc->cert_verify_mac(s, NID_sha1,
 643                                                      &(s->s3->
 644                                                        tmp.cert_verify_md
 645                                                        [MD5_DIGEST_LENGTH]));
 646             }
 647             break;
 648
 649         case SSL3_ST_SR_CERT_VRFY_A:
 650         case SSL3_ST_SR_CERT_VRFY_B:
 651             ret = ssl3_get_cert_verify(s);
 652             if (ret <= 0)
 653                 goto end;
 654 #ifndef OPENSSL_NO_SCTP
 655             if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
 656                 state == SSL_ST_RENEGOTIATE)
 657                 s->state = DTLS1_SCTP_ST_SR_READ_SOCK;
 658             else
 659 #endif
 660                 s->state = SSL3_ST_SR_CHANGE_A;
 661             s->init_num = 0;
 662             break;
 663
 664         case SSL3_ST_SR_CHANGE_A:
 665         case SSL3_ST_SR_CHANGE_B:
 666             ret = ssl3_get_change_cipher_spec(s, SSL3_ST_SR_CHANGE_A,
 667                                               SSL3_ST_SR_CHANGE_B);
 668             if (ret <= 0)
 669                 goto end;
 670
 671             s->state = SSL3_ST_SR_FINISHED_A;
 672             s->init_num = 0;
 673             break;
 674
 675         case SSL3_ST_SR_FINISHED_A:
 676         case SSL3_ST_SR_FINISHED_B:
 677             ret = ssl3_get_finished(s, SSL3_ST_SR_FINISHED_A,
 678                                     SSL3_ST_SR_FINISHED_B);
 679             if (ret <= 0)
 680                 goto end;
 681             dtls1_stop_timer(s);
 682             if (s->hit)
 683                 s->state = SSL_ST_OK;
 684             else if (s->tlsext_ticket_expected)
 685                 s->state = SSL3_ST_SW_SESSION_TICKET_A;
 686             else
 687                 s->state = SSL3_ST_SW_CHANGE_A;
 688             s->init_num = 0;
 689             break;
 690
 691         case SSL3_ST_SW_SESSION_TICKET_A:
 692         case SSL3_ST_SW_SESSION_TICKET_B:
 693             ret = ssl3_send_newsession_ticket(s);
 694             if (ret <= 0)
 695                 goto end;
 696             s->state = SSL3_ST_SW_CHANGE_A;
 697             s->init_num = 0;
 698             break;
 699
 700         case SSL3_ST_SW_CERT_STATUS_A:
 701         case SSL3_ST_SW_CERT_STATUS_B:
 702             ret = ssl3_send_cert_status(s);
 703             if (ret <= 0)
 704                 goto end;
 705             s->state = SSL3_ST_SW_KEY_EXCH_A;
 706             s->init_num = 0;
 707             break;
 708
 709         case SSL3_ST_SW_CHANGE_A:
 710         case SSL3_ST_SW_CHANGE_B:
 711
 712             s->session->cipher = s->s3->tmp.new_cipher;
 713             if (!s->method->ssl3_enc->setup_key_block(s)) {
 714                 ret = -1;
 715                 s->state = SSL_ST_ERR;
 716                 goto end;
 717             }
 718
 719             ret = dtls1_send_change_cipher_spec(s,
 720                                                 SSL3_ST_SW_CHANGE_A,
 721                                                 SSL3_ST_SW_CHANGE_B);
 722
 723             if (ret <= 0)
 724                 goto end;
 725
 726 #ifndef OPENSSL_NO_SCTP
 727             if (!s->hit) {
 728                 /*
 729                  * Change to new shared key of SCTP-Auth, will be ignored if
 730                  * no SCTP used.
 731                  */
 732                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 733                          0, NULL);
 734             }
 735 #endif
 736
 737             s->state = SSL3_ST_SW_FINISHED_A;
 738             s->init_num = 0;
 739
 740             if (!s->method->ssl3_enc->change_cipher_state(s,
 741                                                           SSL3_CHANGE_CIPHER_SERVER_WRITE))
 742             {
 743                 ret = -1;
 744                 s->state = SSL_ST_ERR;
 745                 goto end;
 746             }
 747
 748             dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
 749             break;
 750
 751         case SSL3_ST_SW_FINISHED_A:
 752         case SSL3_ST_SW_FINISHED_B:
 753             ret = ssl3_send_finished(s,
 754                                      SSL3_ST_SW_FINISHED_A,
 755                                      SSL3_ST_SW_FINISHED_B,
 756                                      s->method->
 757                                      ssl3_enc->server_finished_label,
 758                                      s->method->
 759                                      ssl3_enc->server_finished_label_len);
 760             if (ret <= 0)
 761                 goto end;
 762             s->state = SSL3_ST_SW_FLUSH;
 763             if (s->hit) {
 764                 s->s3->tmp.next_state = SSL3_ST_SR_CHANGE_A;
 765
 766 #ifndef OPENSSL_NO_SCTP
 767                 /*
 768                  * Change to new shared key of SCTP-Auth, will be ignored if
 769                  * no SCTP used.
 770                  */
 771                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 772                          0, NULL);
 773 #endif
 774             } else {
 775                 s->s3->tmp.next_state = SSL_ST_OK;
 776 #ifndef OPENSSL_NO_SCTP
 777                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 778                     s->d1->next_state = s->s3->tmp.next_state;
 779                     s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 780                 }
 781 #endif
 782             }
 783             s->init_num = 0;
 784             break;
 785
 786         case SSL_ST_OK:
 787             /* clean a few things up */
 788             ssl3_cleanup_key_block(s);
 789
 790             /* remove buffering on output */
 791             ssl_free_wbio_buffer(s);
 792
 793             s->init_num = 0;
 794
 795             if (s->renegotiate == 2) { /* skipped if we just sent a
 796                                         * HelloRequest */
 797                 s->renegotiate = 0;
 798                 s->new_session = 0;
 799
 800                 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
 801
 802                 s->ctx->stats.sess_accept_good++;
 803                 /* s->server=1; */
 804                 s->handshake_func = dtls1_accept;
 805
 806                 if (cb != NULL)
 807                     cb(s, SSL_CB_HANDSHAKE_DONE, 1);
 808             }
 809
 810             ret = 1;
 811
 812             /* done handshaking, next message is client hello */
 813             s->d1->handshake_read_seq = 0;
 814             /* next message is server hello */
 815             s->d1->handshake_write_seq = 0;
 816             s->d1->next_handshake_write_seq = 0;
 817             goto end;
 818             /* break; */
 819
 820         case SSL_ST_ERR:
 821         default:
 822             SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_UNKNOWN_STATE);
 823             ret = -1;
 824             goto end;
 825             /* break; */
 826         }
 827
 828         if (!s->s3->tmp.reuse_message && !skip) {
 829             if (s->debug) {
 830                 if ((ret = BIO_flush(s->wbio)) <= 0)
 831                     goto end;
 832             }
 833
 834             if ((cb != NULL) && (s->state != state)) {
 835                 new_state = s->state;
 836                 s->state = state;
 837                 cb(s, SSL_CB_ACCEPT_LOOP, 1);
 838                 s->state = new_state;
 839             }
 840         }
 841         skip = 0;
 842     }
 843  end:
 844     /* BIO_flush(s->wbio); */
 845
 846     s->in_handshake--;
 847 #ifndef OPENSSL_NO_SCTP
 848     /*
 849      * Notify SCTP BIO socket to leave handshake mode and prevent stream
 850      * identifier other than 0. Will be ignored if no SCTP is used.
 851      */
 852     BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
 853              s->in_handshake, NULL);
 854 #endif
 855
 856     if (cb != NULL)
 857         cb(s, SSL_CB_ACCEPT_EXIT, ret);
 858     return (ret);
 859 }
 860 #endif
 861
 862 unsigned int dtls1_raw_hello_verify_request(unsigned char *buf,
 863                                             unsigned char *cookie,
 864                                             unsigned char cookie_len)
 865 {
 866     unsigned int msg_len;
 867     unsigned char *p;
 868
 869     p = buf;
 870     /* Always use DTLS 1.0 version: see RFC 6347 */
 871     *(p++) = DTLS1_VERSION >> 8;
 872     *(p++) = DTLS1_VERSION & 0xFF;
 873
 874     *(p++) = (unsigned char)cookie_len;
 875     memcpy(p, cookie, cookie_len);
 876     p += cookie_len;
 877     msg_len = p - buf;
 878
 879     return msg_len;
 880 }
 881
 882
 883 int dtls_construct_hello_verify_request(SSL *s)
 884 {
 885     unsigned int len;
 886     unsigned char *buf;
 887
 888     buf = (unsigned char *)s->init_buf->data;
 889
 890     if (s->ctx->app_gen_cookie_cb == NULL ||
 891         s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
 892                                   &(s->d1->cookie_len)) == 0 ||
 893         s->d1->cookie_len > 255) {
 894         SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,
 895                SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
 896         statem_set_error(s);
 897         return 0;
 898     }
 899
 900     len = dtls1_raw_hello_verify_request(&buf[DTLS1_HM_HEADER_LENGTH],
 901                                          s->d1->cookie, s->d1->cookie_len);
 902
 903     dtls1_set_message_header(s, buf, DTLS1_MT_HELLO_VERIFY_REQUEST, len, 0,
 904                              len);
 905     len += DTLS1_HM_HEADER_LENGTH;
 906
 907     /* number of bytes to write */
 908     s->init_num = len;
 909     s->init_off = 0;
 910
 911     return 1;
 912 }