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     int listen;
 169 #ifndef OPENSSL_NO_SCTP
 170     unsigned char sctpauthkey[64];
 171     char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
 172 #endif
 173
 174     RAND_add(&Time, sizeof(Time), 0);
 175     ERR_clear_error();
 176     clear_sys_error();
 177
 178     if (s->info_callback != NULL)
 179         cb = s->info_callback;
 180     else if (s->ctx->info_callback != NULL)
 181         cb = s->ctx->info_callback;
 182
 183     listen = s->d1->listen;
 184
 185     /* init things to blank */
 186     s->in_handshake++;
 187     if (!SSL_in_init(s) || SSL_in_before(s))
 188         SSL_clear(s);
 189
 190     s->d1->listen = listen;
 191 #ifndef OPENSSL_NO_SCTP
 192     /*
 193      * Notify SCTP BIO socket to enter handshake mode and prevent stream
 194      * identifier other than 0. Will be ignored if no SCTP is used.
 195      */
 196     BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
 197              s->in_handshake, NULL);
 198 #endif
 199
 200     if (s->cert == NULL) {
 201         SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_NO_CERTIFICATE_SET);
 202         return (-1);
 203     }
 204 #ifndef OPENSSL_NO_HEARTBEATS
 205     /*
 206      * If we're awaiting a HeartbeatResponse, pretend we already got and
 207      * don't await it anymore, because Heartbeats don't make sense during
 208      * handshakes anyway.
 209      */
 210     if (s->tlsext_hb_pending) {
 211         dtls1_stop_timer(s);
 212         s->tlsext_hb_pending = 0;
 213         s->tlsext_hb_seq++;
 214     }
 215 #endif
 216
 217     for (;;) {
 218         state = s->state;
 219
 220         switch (s->state) {
 221         case SSL_ST_RENEGOTIATE:
 222             s->renegotiate = 1;
 223             /* s->state=SSL_ST_ACCEPT; */
 224
 225         case SSL_ST_BEFORE:
 226         case SSL_ST_ACCEPT:
 227         case SSL_ST_BEFORE | SSL_ST_ACCEPT:
 228         case SSL_ST_OK | SSL_ST_ACCEPT:
 229
 230             s->server = 1;
 231             if (cb != NULL)
 232                 cb(s, SSL_CB_HANDSHAKE_START, 1);
 233
 234             if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
 235                 SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 236                 return -1;
 237             }
 238             s->type = SSL_ST_ACCEPT;
 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                     BUF_MEM_free(buf);
 248                     ret = -1;
 249                     s->state = SSL_ST_ERR;
 250                     goto end;
 251                 }
 252                 s->init_buf = buf;
 253             }
 254
 255             if (!ssl3_setup_buffers(s)) {
 256                 ret = -1;
 257                 s->state = SSL_ST_ERR;
 258                 goto end;
 259             }
 260
 261             s->init_num = 0;
 262             s->d1->change_cipher_spec_ok = 0;
 263             /*
 264              * Should have been reset by ssl3_get_finished, too.
 265              */
 266             s->s3->change_cipher_spec = 0;
 267
 268             if (s->state != SSL_ST_RENEGOTIATE) {
 269                 /*
 270                  * Ok, we now need to push on a buffering BIO so that the
 271                  * output is sent in a way that TCP likes :-) ...but not with
 272                  * SCTP :-)
 273                  */
 274 #ifndef OPENSSL_NO_SCTP
 275                 if (!BIO_dgram_is_sctp(SSL_get_wbio(s)))
 276 #endif
 277                     if (!ssl_init_wbio_buffer(s, 1)) {
 278                         ret = -1;
 279                         s->state = SSL_ST_ERR;
 280                         goto end;
 281                     }
 282
 283                 ssl3_init_finished_mac(s);
 284                 s->state = SSL3_ST_SR_CLNT_HELLO_A;
 285                 s->ctx->stats.sess_accept++;
 286             } else {
 287                 /*
 288                  * s->state == SSL_ST_RENEGOTIATE, we will just send a
 289                  * HelloRequest
 290                  */
 291                 s->ctx->stats.sess_accept_renegotiate++;
 292                 s->state = SSL3_ST_SW_HELLO_REQ_A;
 293             }
 294
 295             break;
 296
 297         case SSL3_ST_SW_HELLO_REQ_A:
 298         case SSL3_ST_SW_HELLO_REQ_B:
 299
 300             s->shutdown = 0;
 301             dtls1_clear_record_buffer(s);
 302             dtls1_start_timer(s);
 303             ret = ssl3_send_hello_request(s);
 304             if (ret <= 0)
 305                 goto end;
 306             s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
 307             s->state = SSL3_ST_SW_FLUSH;
 308             s->init_num = 0;
 309
 310             ssl3_init_finished_mac(s);
 311             break;
 312
 313         case SSL3_ST_SW_HELLO_REQ_C:
 314             s->state = SSL_ST_OK;
 315             break;
 316
 317         case SSL3_ST_SR_CLNT_HELLO_A:
 318         case SSL3_ST_SR_CLNT_HELLO_B:
 319         case SSL3_ST_SR_CLNT_HELLO_C:
 320
 321             s->shutdown = 0;
 322             ret = ssl3_get_client_hello(s);
 323             if (ret <= 0)
 324                 goto end;
 325             dtls1_stop_timer(s);
 326
 327             if (ret == 1 && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
 328                 s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
 329             else
 330                 s->state = SSL3_ST_SW_SRVR_HELLO_A;
 331
 332             s->init_num = 0;
 333
 334             /*
 335              * Reflect ClientHello sequence to remain stateless while
 336              * listening
 337              */
 338             if (listen) {
 339                 memcpy(s->s3->write_sequence, s->s3->read_sequence,
 340                        sizeof(s->s3->write_sequence));
 341             }
 342
 343             /* If we're just listening, stop here */
 344             if (listen && s->state == SSL3_ST_SW_SRVR_HELLO_A) {
 345                 ret = 2;
 346                 s->d1->listen = 0;
 347                 /*
 348                  * Set expected sequence numbers to continue the handshake.
 349                  */
 350                 s->d1->handshake_read_seq = 2;
 351                 s->d1->handshake_write_seq = 1;
 352                 s->d1->next_handshake_write_seq = 1;
 353                 goto end;
 354             }
 355
 356             break;
 357
 358         case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
 359         case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
 360
 361             ret = dtls1_send_hello_verify_request(s);
 362             if (ret <= 0)
 363                 goto end;
 364             s->state = SSL3_ST_SW_FLUSH;
 365             s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
 366
 367             /* HelloVerifyRequest resets Finished MAC */
 368             if (s->version != DTLS1_BAD_VER)
 369                 ssl3_init_finished_mac(s);
 370             break;
 371
 372 #ifndef OPENSSL_NO_SCTP
 373         case DTLS1_SCTP_ST_SR_READ_SOCK:
 374
 375             if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
 376                 s->s3->in_read_app_data = 2;
 377                 s->rwstate = SSL_READING;
 378                 BIO_clear_retry_flags(SSL_get_rbio(s));
 379                 BIO_set_retry_read(SSL_get_rbio(s));
 380                 ret = -1;
 381                 goto end;
 382             }
 383
 384             s->state = SSL3_ST_SR_FINISHED_A;
 385             break;
 386
 387         case DTLS1_SCTP_ST_SW_WRITE_SOCK:
 388             ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
 389             if (ret < 0)
 390                 goto end;
 391
 392             if (ret == 0) {
 393                 if (s->d1->next_state != SSL_ST_OK) {
 394                     s->s3->in_read_app_data = 2;
 395                     s->rwstate = SSL_READING;
 396                     BIO_clear_retry_flags(SSL_get_rbio(s));
 397                     BIO_set_retry_read(SSL_get_rbio(s));
 398                     ret = -1;
 399                     goto end;
 400                 }
 401             }
 402
 403             s->state = s->d1->next_state;
 404             break;
 405 #endif
 406
 407         case SSL3_ST_SW_SRVR_HELLO_A:
 408         case SSL3_ST_SW_SRVR_HELLO_B:
 409             s->renegotiate = 2;
 410             dtls1_start_timer(s);
 411             ret = ssl3_send_server_hello(s);
 412             if (ret <= 0)
 413                 goto end;
 414
 415             if (s->hit) {
 416 #ifndef OPENSSL_NO_SCTP
 417                 /*
 418                  * Add new shared key for SCTP-Auth, will be ignored if no
 419                  * SCTP used.
 420                  */
 421                 snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 422                          DTLS1_SCTP_AUTH_LABEL);
 423
 424                 SSL_export_keying_material(s, sctpauthkey,
 425                                            sizeof(sctpauthkey), labelbuffer,
 426                                            sizeof(labelbuffer), NULL, 0, 0);
 427
 428                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 429                          sizeof(sctpauthkey), sctpauthkey);
 430 #endif
 431 #ifndef OPENSSL_NO_TLSEXT
 432                 if (s->tlsext_ticket_expected)
 433                     s->state = SSL3_ST_SW_SESSION_TICKET_A;
 434                 else
 435                     s->state = SSL3_ST_SW_CHANGE_A;
 436 #else
 437                 s->state = SSL3_ST_SW_CHANGE_A;
 438 #endif
 439             } else
 440                 s->state = SSL3_ST_SW_CERT_A;
 441             s->init_num = 0;
 442             break;
 443
 444         case SSL3_ST_SW_CERT_A:
 445         case SSL3_ST_SW_CERT_B:
 446             /* Check if it is anon DH or normal PSK */
 447             if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
 448                 && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
 449                 dtls1_start_timer(s);
 450                 ret = ssl3_send_server_certificate(s);
 451                 if (ret <= 0)
 452                     goto end;
 453 #ifndef OPENSSL_NO_TLSEXT
 454                 if (s->tlsext_status_expected)
 455                     s->state = SSL3_ST_SW_CERT_STATUS_A;
 456                 else
 457                     s->state = SSL3_ST_SW_KEY_EXCH_A;
 458             } else {
 459                 skip = 1;
 460                 s->state = SSL3_ST_SW_KEY_EXCH_A;
 461             }
 462 #else
 463             } else
 464                 skip = 1;
 465
 466             s->state = SSL3_ST_SW_KEY_EXCH_A;
 467 #endif
 468             s->init_num = 0;
 469             break;
 470
 471         case SSL3_ST_SW_KEY_EXCH_A:
 472         case SSL3_ST_SW_KEY_EXCH_B:
 473             alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
 474
 475             /*
 476              * clear this, it may get reset by
 477              * send_server_key_exchange
 478              */
 479             s->s3->tmp.use_rsa_tmp = 0;
 480
 481             /*
 482              * only send if a DH key exchange or RSA but we have a sign only
 483              * certificate
 484              */
 485             if (0
 486                 /*
 487                  * PSK: send ServerKeyExchange if PSK identity hint if
 488                  * provided
 489                  */
 490 #ifndef OPENSSL_NO_PSK
 491                 || ((alg_k & SSL_kPSK) && s->ctx->psk_identity_hint)
 492 #endif
 493                 || (alg_k & SSL_kDHE)
 494                 || (alg_k & SSL_kEECDH)
 495                 || ((alg_k & SSL_kRSA)
 496                     && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
 497                         || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
 498                             && EVP_PKEY_size(s->cert->pkeys
 499                                              [SSL_PKEY_RSA_ENC].privatekey) *
 500                             8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
 501                         )
 502                     )
 503                 )
 504                 ) {
 505                 dtls1_start_timer(s);
 506                 ret = ssl3_send_server_key_exchange(s);
 507                 if (ret <= 0)
 508                     goto end;
 509             } else
 510                 skip = 1;
 511
 512             s->state = SSL3_ST_SW_CERT_REQ_A;
 513             s->init_num = 0;
 514             break;
 515
 516         case SSL3_ST_SW_CERT_REQ_A:
 517         case SSL3_ST_SW_CERT_REQ_B:
 518             if (                /* don't request cert unless asked for it: */
 519                    !(s->verify_mode & SSL_VERIFY_PEER) ||
 520                    /*
 521                     * if SSL_VERIFY_CLIENT_ONCE is set, don't request cert
 522                     * during re-negotiation:
 523                     */
 524                    ((s->session->peer != NULL) &&
 525                     (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
 526                    /*
 527                     * never request cert in anonymous ciphersuites (see
 528                     * section "Certificate request" in SSL 3 drafts and in
 529                     * RFC 2246):
 530                     */
 531                    ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
 532                     /*
 533                      * ... except when the application insists on
 534                      * verification (against the specs, but s3_clnt.c accepts
 535                      * this for SSL 3)
 536                      */
 537                     !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
 538                    /*
 539                     * never request cert in Kerberos ciphersuites
 540                     */
 541                    (s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5)
 542                    /*
 543                     * With normal PSK Certificates and Certificate Requests
 544                     * are omitted
 545                     */
 546                    || (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
 547                 /* no cert request */
 548                 skip = 1;
 549                 s->s3->tmp.cert_request = 0;
 550                 s->state = SSL3_ST_SW_SRVR_DONE_A;
 551 #ifndef OPENSSL_NO_SCTP
 552                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 553                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 554                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 555                 }
 556 #endif
 557             } else {
 558                 s->s3->tmp.cert_request = 1;
 559                 dtls1_start_timer(s);
 560                 ret = ssl3_send_certificate_request(s);
 561                 if (ret <= 0)
 562                     goto end;
 563 #ifndef NETSCAPE_HANG_BUG
 564                 s->state = SSL3_ST_SW_SRVR_DONE_A;
 565 # ifndef OPENSSL_NO_SCTP
 566                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 567                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 568                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 569                 }
 570 # endif
 571 #else
 572                 s->state = SSL3_ST_SW_FLUSH;
 573                 s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
 574 # ifndef OPENSSL_NO_SCTP
 575                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 576                     s->d1->next_state = s->s3->tmp.next_state;
 577                     s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 578                 }
 579 # endif
 580 #endif
 581                 s->init_num = 0;
 582             }
 583             break;
 584
 585         case SSL3_ST_SW_SRVR_DONE_A:
 586         case SSL3_ST_SW_SRVR_DONE_B:
 587             dtls1_start_timer(s);
 588             ret = ssl3_send_server_done(s);
 589             if (ret <= 0)
 590                 goto end;
 591             s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
 592             s->state = SSL3_ST_SW_FLUSH;
 593             s->init_num = 0;
 594             break;
 595
 596         case SSL3_ST_SW_FLUSH:
 597             s->rwstate = SSL_WRITING;
 598             if (BIO_flush(s->wbio) <= 0) {
 599                 /*
 600                  * If the write error was fatal, stop trying
 601                  */
 602                 if (!BIO_should_retry(s->wbio)) {
 603                     s->rwstate = SSL_NOTHING;
 604                     s->state = s->s3->tmp.next_state;
 605                 }
 606
 607                 ret = -1;
 608                 goto end;
 609             }
 610             s->rwstate = SSL_NOTHING;
 611             s->state = s->s3->tmp.next_state;
 612             break;
 613
 614         case SSL3_ST_SR_CERT_A:
 615         case SSL3_ST_SR_CERT_B:
 616             if (s->s3->tmp.cert_request) {
 617                 ret = ssl3_get_client_certificate(s);
 618                 if (ret <= 0)
 619                     goto end;
 620             }
 621             s->init_num = 0;
 622             s->state = SSL3_ST_SR_KEY_EXCH_A;
 623             break;
 624
 625         case SSL3_ST_SR_KEY_EXCH_A:
 626         case SSL3_ST_SR_KEY_EXCH_B:
 627             ret = ssl3_get_client_key_exchange(s);
 628             if (ret <= 0)
 629                 goto end;
 630 #ifndef OPENSSL_NO_SCTP
 631             /*
 632              * Add new shared key for SCTP-Auth, will be ignored if no SCTP
 633              * used.
 634              */
 635             snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 636                      DTLS1_SCTP_AUTH_LABEL);
 637
 638             SSL_export_keying_material(s, sctpauthkey,
 639                                        sizeof(sctpauthkey), labelbuffer,
 640                                        sizeof(labelbuffer), NULL, 0, 0);
 641
 642             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 643                      sizeof(sctpauthkey), sctpauthkey);
 644 #endif
 645
 646             s->state = SSL3_ST_SR_CERT_VRFY_A;
 647             s->init_num = 0;
 648
 649             if (ret == 2) {
 650                 /*
 651                  * For the ECDH ciphersuites when the client sends its ECDH
 652                  * pub key in a certificate, the CertificateVerify message is
 653                  * not sent.
 654                  */
 655                 s->state = SSL3_ST_SR_FINISHED_A;
 656                 s->init_num = 0;
 657             } else if (SSL_USE_SIGALGS(s)) {
 658                 s->state = SSL3_ST_SR_CERT_VRFY_A;
 659                 s->init_num = 0;
 660                 if (!s->session->peer)
 661                     break;
 662                 /*
 663                  * For sigalgs freeze the handshake buffer at this point and
 664                  * digest cached records.
 665                  */
 666                 if (!s->s3->handshake_buffer) {
 667                     SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 668                     s->state = SSL_ST_ERR;
 669                     return -1;
 670                 }
 671                 s->s3->flags |= TLS1_FLAGS_KEEP_HANDSHAKE;
 672                 if (!ssl3_digest_cached_records(s)) {
 673                     s->state = SSL_ST_ERR;
 674                     return -1;
 675                 }
 676             } else {
 677                 s->state = SSL3_ST_SR_CERT_VRFY_A;
 678                 s->init_num = 0;
 679
 680                 /*
 681                  * We need to get hashes here so if there is a client cert,
 682                  * it can be verified
 683                  */
 684                 s->method->ssl3_enc->cert_verify_mac(s,
 685                                                      NID_md5,
 686                                                      &(s->s3->
 687                                                        tmp.cert_verify_md
 688                                                        [0]));
 689                 s->method->ssl3_enc->cert_verify_mac(s, NID_sha1,
 690                                                      &(s->s3->
 691                                                        tmp.cert_verify_md
 692                                                        [MD5_DIGEST_LENGTH]));
 693             }
 694             break;
 695
 696         case SSL3_ST_SR_CERT_VRFY_A:
 697         case SSL3_ST_SR_CERT_VRFY_B:
 698             ret = ssl3_get_cert_verify(s);
 699             if (ret <= 0)
 700                 goto end;
 701 #ifndef OPENSSL_NO_SCTP
 702             if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
 703                 state == SSL_ST_RENEGOTIATE)
 704                 s->state = DTLS1_SCTP_ST_SR_READ_SOCK;
 705             else
 706 #endif
 707                 s->state = SSL3_ST_SR_FINISHED_A;
 708             s->init_num = 0;
 709             break;
 710
 711         case SSL3_ST_SR_FINISHED_A:
 712         case SSL3_ST_SR_FINISHED_B:
 713             /*
 714              * Enable CCS. Receiving a CCS clears the flag, so make
 715              * sure not to re-enable it to ban duplicates. This *should* be the
 716              * first time we have received one - but we check anyway to be
 717              * cautious.
 718              * s->s3->change_cipher_spec is set when a CCS is
 719              * processed in d1_pkt.c, and remains set until
 720              * the client's Finished message is read.
 721              */
 722             if (!s->s3->change_cipher_spec)
 723                 s->d1->change_cipher_spec_ok = 1;
 724             ret = ssl3_get_finished(s, SSL3_ST_SR_FINISHED_A,
 725                                     SSL3_ST_SR_FINISHED_B);
 726             if (ret <= 0)
 727                 goto end;
 728             dtls1_stop_timer(s);
 729             if (s->hit)
 730                 s->state = SSL_ST_OK;
 731 #ifndef OPENSSL_NO_TLSEXT
 732             else if (s->tlsext_ticket_expected)
 733                 s->state = SSL3_ST_SW_SESSION_TICKET_A;
 734 #endif
 735             else
 736                 s->state = SSL3_ST_SW_CHANGE_A;
 737             s->init_num = 0;
 738             break;
 739
 740 #ifndef OPENSSL_NO_TLSEXT
 741         case SSL3_ST_SW_SESSION_TICKET_A:
 742         case SSL3_ST_SW_SESSION_TICKET_B:
 743             ret = ssl3_send_newsession_ticket(s);
 744             if (ret <= 0)
 745                 goto end;
 746             s->state = SSL3_ST_SW_CHANGE_A;
 747             s->init_num = 0;
 748             break;
 749
 750         case SSL3_ST_SW_CERT_STATUS_A:
 751         case SSL3_ST_SW_CERT_STATUS_B:
 752             ret = ssl3_send_cert_status(s);
 753             if (ret <= 0)
 754                 goto end;
 755             s->state = SSL3_ST_SW_KEY_EXCH_A;
 756             s->init_num = 0;
 757             break;
 758
 759 #endif
 760
 761         case SSL3_ST_SW_CHANGE_A:
 762         case SSL3_ST_SW_CHANGE_B:
 763
 764             s->session->cipher = s->s3->tmp.new_cipher;
 765             if (!s->method->ssl3_enc->setup_key_block(s)) {
 766                 ret = -1;
 767                 s->state = SSL_ST_ERR;
 768                 goto end;
 769             }
 770
 771             ret = dtls1_send_change_cipher_spec(s,
 772                                                 SSL3_ST_SW_CHANGE_A,
 773                                                 SSL3_ST_SW_CHANGE_B);
 774
 775             if (ret <= 0)
 776                 goto end;
 777
 778 #ifndef OPENSSL_NO_SCTP
 779             if (!s->hit) {
 780                 /*
 781                  * Change to new shared key of SCTP-Auth, will be ignored if
 782                  * no SCTP used.
 783                  */
 784                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 785                          0, NULL);
 786             }
 787 #endif
 788
 789             s->state = SSL3_ST_SW_FINISHED_A;
 790             s->init_num = 0;
 791
 792             if (!s->method->ssl3_enc->change_cipher_state(s,
 793                                                           SSL3_CHANGE_CIPHER_SERVER_WRITE))
 794             {
 795                 ret = -1;
 796                 s->state = SSL_ST_ERR;
 797                 goto end;
 798             }
 799
 800             dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
 801             break;
 802
 803         case SSL3_ST_SW_FINISHED_A:
 804         case SSL3_ST_SW_FINISHED_B:
 805             ret = ssl3_send_finished(s,
 806                                      SSL3_ST_SW_FINISHED_A,
 807                                      SSL3_ST_SW_FINISHED_B,
 808                                      s->method->
 809                                      ssl3_enc->server_finished_label,
 810                                      s->method->
 811                                      ssl3_enc->server_finished_label_len);
 812             if (ret <= 0)
 813                 goto end;
 814             s->state = SSL3_ST_SW_FLUSH;
 815             if (s->hit) {
 816                 s->s3->tmp.next_state = SSL3_ST_SR_FINISHED_A;
 817
 818 #ifndef OPENSSL_NO_SCTP
 819                 /*
 820                  * Change to new shared key of SCTP-Auth, will be ignored if
 821                  * no SCTP used.
 822                  */
 823                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 824                          0, NULL);
 825 #endif
 826             } else {
 827                 s->s3->tmp.next_state = SSL_ST_OK;
 828 #ifndef OPENSSL_NO_SCTP
 829                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 830                     s->d1->next_state = s->s3->tmp.next_state;
 831                     s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 832                 }
 833 #endif
 834             }
 835             s->init_num = 0;
 836             break;
 837
 838         case SSL_ST_OK:
 839             /* clean a few things up */
 840             ssl3_cleanup_key_block(s);
 841
 842 #if 0
 843             BUF_MEM_free(s->init_buf);
 844             s->init_buf = NULL;
 845 #endif
 846
 847             /* remove buffering on output */
 848             ssl_free_wbio_buffer(s);
 849
 850             s->init_num = 0;
 851
 852             if (s->renegotiate == 2) { /* skipped if we just sent a
 853                                         * HelloRequest */
 854                 s->renegotiate = 0;
 855                 s->new_session = 0;
 856
 857                 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
 858
 859                 s->ctx->stats.sess_accept_good++;
 860                 /* s->server=1; */
 861                 s->handshake_func = dtls1_accept;
 862
 863                 if (cb != NULL)
 864                     cb(s, SSL_CB_HANDSHAKE_DONE, 1);
 865             }
 866
 867             ret = 1;
 868
 869             /* done handshaking, next message is client hello */
 870             s->d1->handshake_read_seq = 0;
 871             /* next message is server hello */
 872             s->d1->handshake_write_seq = 0;
 873             s->d1->next_handshake_write_seq = 0;
 874             goto end;
 875             /* break; */
 876
 877         case SSL_ST_ERR:
 878         default:
 879             SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_UNKNOWN_STATE);
 880             ret = -1;
 881             goto end;
 882             /* break; */
 883         }
 884
 885         if (!s->s3->tmp.reuse_message && !skip) {
 886             if (s->debug) {
 887                 if ((ret = BIO_flush(s->wbio)) <= 0)
 888                     goto end;
 889             }
 890
 891             if ((cb != NULL) && (s->state != state)) {
 892                 new_state = s->state;
 893                 s->state = state;
 894                 cb(s, SSL_CB_ACCEPT_LOOP, 1);
 895                 s->state = new_state;
 896             }
 897         }
 898         skip = 0;
 899     }
 900  end:
 901     /* BIO_flush(s->wbio); */
 902
 903     s->in_handshake--;
 904 #ifndef OPENSSL_NO_SCTP
 905     /*
 906      * Notify SCTP BIO socket to leave handshake mode and prevent stream
 907      * identifier other than 0. Will be ignored if no SCTP is used.
 908      */
 909     BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
 910              s->in_handshake, NULL);
 911 #endif
 912
 913     if (cb != NULL)
 914         cb(s, SSL_CB_ACCEPT_EXIT, ret);
 915     return (ret);
 916 }
 917
 918 int dtls1_send_hello_verify_request(SSL *s)
 919 {
 920     unsigned int msg_len;
 921     unsigned char *msg, *buf, *p;
 922
 923     if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) {
 924         buf = (unsigned char *)s->init_buf->data;
 925
 926         msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
 927         /* Always use DTLS 1.0 version: see RFC 6347 */
 928         *(p++) = DTLS1_VERSION >> 8;
 929         *(p++) = DTLS1_VERSION & 0xFF;
 930
 931         if (s->ctx->app_gen_cookie_cb == NULL ||
 932             s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
 933                                       &(s->d1->cookie_len)) == 0) {
 934             SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,
 935                    ERR_R_INTERNAL_ERROR);
 936             s->state = SSL_ST_ERR;
 937             return 0;
 938         }
 939
 940         *(p++) = (unsigned char)s->d1->cookie_len;
 941         memcpy(p, s->d1->cookie, s->d1->cookie_len);
 942         p += s->d1->cookie_len;
 943         msg_len = p - msg;
 944
 945         dtls1_set_message_header(s, buf,
 946                                  DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0,
 947                                  msg_len);
 948
 949         s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
 950         /* number of bytes to write */
 951         s->init_num = p - buf;
 952         s->init_off = 0;
 953     }
 954
 955     /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
 956     return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
 957 }