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                 if (SSL_export_keying_material(s, sctpauthkey,
 425                         sizeof(sctpauthkey), labelbuffer,
 426                         sizeof(labelbuffer), NULL, 0, 0) <= 0) {
 427                     ret = -1;
 428                     s->state = SSL_ST_ERR;
 429                     goto end;
 430                 }
 431
 432                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 433                          sizeof(sctpauthkey), sctpauthkey);
 434 #endif
 435 #ifndef OPENSSL_NO_TLSEXT
 436                 if (s->tlsext_ticket_expected)
 437                     s->state = SSL3_ST_SW_SESSION_TICKET_A;
 438                 else
 439                     s->state = SSL3_ST_SW_CHANGE_A;
 440 #else
 441                 s->state = SSL3_ST_SW_CHANGE_A;
 442 #endif
 443             } else
 444                 s->state = SSL3_ST_SW_CERT_A;
 445             s->init_num = 0;
 446             break;
 447
 448         case SSL3_ST_SW_CERT_A:
 449         case SSL3_ST_SW_CERT_B:
 450             /* Check if it is anon DH or normal PSK */
 451             if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
 452                 && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
 453                 dtls1_start_timer(s);
 454                 ret = ssl3_send_server_certificate(s);
 455                 if (ret <= 0)
 456                     goto end;
 457 #ifndef OPENSSL_NO_TLSEXT
 458                 if (s->tlsext_status_expected)
 459                     s->state = SSL3_ST_SW_CERT_STATUS_A;
 460                 else
 461                     s->state = SSL3_ST_SW_KEY_EXCH_A;
 462             } else {
 463                 skip = 1;
 464                 s->state = SSL3_ST_SW_KEY_EXCH_A;
 465             }
 466 #else
 467             } else
 468                 skip = 1;
 469
 470             s->state = SSL3_ST_SW_KEY_EXCH_A;
 471 #endif
 472             s->init_num = 0;
 473             break;
 474
 475         case SSL3_ST_SW_KEY_EXCH_A:
 476         case SSL3_ST_SW_KEY_EXCH_B:
 477             alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
 478
 479             /*
 480              * clear this, it may get reset by
 481              * send_server_key_exchange
 482              */
 483             s->s3->tmp.use_rsa_tmp = 0;
 484
 485             /*
 486              * only send if a DH key exchange or RSA but we have a sign only
 487              * certificate
 488              */
 489             if (0
 490                 /*
 491                  * PSK: send ServerKeyExchange if PSK identity hint if
 492                  * provided
 493                  */
 494 #ifndef OPENSSL_NO_PSK
 495                 || ((alg_k & SSL_kPSK) && s->ctx->psk_identity_hint)
 496 #endif
 497                 || (alg_k & SSL_kDHE)
 498                 || (alg_k & SSL_kEECDH)
 499                 || ((alg_k & SSL_kRSA)
 500                     && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
 501                         || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
 502                             && EVP_PKEY_size(s->cert->pkeys
 503                                              [SSL_PKEY_RSA_ENC].privatekey) *
 504                             8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
 505                         )
 506                     )
 507                 )
 508                 ) {
 509                 dtls1_start_timer(s);
 510                 ret = ssl3_send_server_key_exchange(s);
 511                 if (ret <= 0)
 512                     goto end;
 513             } else
 514                 skip = 1;
 515
 516             s->state = SSL3_ST_SW_CERT_REQ_A;
 517             s->init_num = 0;
 518             break;
 519
 520         case SSL3_ST_SW_CERT_REQ_A:
 521         case SSL3_ST_SW_CERT_REQ_B:
 522             if (                /* don't request cert unless asked for it: */
 523                    !(s->verify_mode & SSL_VERIFY_PEER) ||
 524                    /*
 525                     * if SSL_VERIFY_CLIENT_ONCE is set, don't request cert
 526                     * during re-negotiation:
 527                     */
 528                    ((s->session->peer != NULL) &&
 529                     (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
 530                    /*
 531                     * never request cert in anonymous ciphersuites (see
 532                     * section "Certificate request" in SSL 3 drafts and in
 533                     * RFC 2246):
 534                     */
 535                    ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
 536                     /*
 537                      * ... except when the application insists on
 538                      * verification (against the specs, but s3_clnt.c accepts
 539                      * this for SSL 3)
 540                      */
 541                     !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
 542                    /*
 543                     * never request cert in Kerberos ciphersuites
 544                     */
 545                    (s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5)
 546                    /*
 547                     * With normal PSK Certificates and Certificate Requests
 548                     * are omitted
 549                     */
 550                    || (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
 551                 /* no cert request */
 552                 skip = 1;
 553                 s->s3->tmp.cert_request = 0;
 554                 s->state = SSL3_ST_SW_SRVR_DONE_A;
 555 #ifndef OPENSSL_NO_SCTP
 556                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 557                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 558                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 559                 }
 560 #endif
 561             } else {
 562                 s->s3->tmp.cert_request = 1;
 563                 dtls1_start_timer(s);
 564                 ret = ssl3_send_certificate_request(s);
 565                 if (ret <= 0)
 566                     goto end;
 567 #ifndef NETSCAPE_HANG_BUG
 568                 s->state = SSL3_ST_SW_SRVR_DONE_A;
 569 # ifndef OPENSSL_NO_SCTP
 570                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 571                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 572                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 573                 }
 574 # endif
 575 #else
 576                 s->state = SSL3_ST_SW_FLUSH;
 577                 s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
 578 # ifndef OPENSSL_NO_SCTP
 579                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 580                     s->d1->next_state = s->s3->tmp.next_state;
 581                     s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 582                 }
 583 # endif
 584 #endif
 585                 s->init_num = 0;
 586             }
 587             break;
 588
 589         case SSL3_ST_SW_SRVR_DONE_A:
 590         case SSL3_ST_SW_SRVR_DONE_B:
 591             dtls1_start_timer(s);
 592             ret = ssl3_send_server_done(s);
 593             if (ret <= 0)
 594                 goto end;
 595             s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
 596             s->state = SSL3_ST_SW_FLUSH;
 597             s->init_num = 0;
 598             break;
 599
 600         case SSL3_ST_SW_FLUSH:
 601             s->rwstate = SSL_WRITING;
 602             if (BIO_flush(s->wbio) <= 0) {
 603                 /*
 604                  * If the write error was fatal, stop trying
 605                  */
 606                 if (!BIO_should_retry(s->wbio)) {
 607                     s->rwstate = SSL_NOTHING;
 608                     s->state = s->s3->tmp.next_state;
 609                 }
 610
 611                 ret = -1;
 612                 goto end;
 613             }
 614             s->rwstate = SSL_NOTHING;
 615             s->state = s->s3->tmp.next_state;
 616             break;
 617
 618         case SSL3_ST_SR_CERT_A:
 619         case SSL3_ST_SR_CERT_B:
 620             if (s->s3->tmp.cert_request) {
 621                 ret = ssl3_get_client_certificate(s);
 622                 if (ret <= 0)
 623                     goto end;
 624             }
 625             s->init_num = 0;
 626             s->state = SSL3_ST_SR_KEY_EXCH_A;
 627             break;
 628
 629         case SSL3_ST_SR_KEY_EXCH_A:
 630         case SSL3_ST_SR_KEY_EXCH_B:
 631             ret = ssl3_get_client_key_exchange(s);
 632             if (ret <= 0)
 633                 goto end;
 634 #ifndef OPENSSL_NO_SCTP
 635             /*
 636              * Add new shared key for SCTP-Auth, will be ignored if no SCTP
 637              * used.
 638              */
 639             snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 640                      DTLS1_SCTP_AUTH_LABEL);
 641
 642             if (SSL_export_keying_material(s, sctpauthkey,
 643                                        sizeof(sctpauthkey), labelbuffer,
 644                                        sizeof(labelbuffer), NULL, 0, 0) <= 0) {
 645                 ret = -1;
 646                 s->state = SSL_ST_ERR;
 647                 goto end;
 648             }
 649
 650             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 651                      sizeof(sctpauthkey), sctpauthkey);
 652 #endif
 653
 654             s->state = SSL3_ST_SR_CERT_VRFY_A;
 655             s->init_num = 0;
 656
 657             if (ret == 2) {
 658                 /*
 659                  * For the ECDH ciphersuites when the client sends its ECDH
 660                  * pub key in a certificate, the CertificateVerify message is
 661                  * not sent.
 662                  */
 663                 s->state = SSL3_ST_SR_FINISHED_A;
 664                 s->init_num = 0;
 665             } else if (SSL_USE_SIGALGS(s)) {
 666                 s->state = SSL3_ST_SR_CERT_VRFY_A;
 667                 s->init_num = 0;
 668                 if (!s->session->peer)
 669                     break;
 670                 /*
 671                  * For sigalgs freeze the handshake buffer at this point and
 672                  * digest cached records.
 673                  */
 674                 if (!s->s3->handshake_buffer) {
 675                     SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 676                     s->state = SSL_ST_ERR;
 677                     return -1;
 678                 }
 679                 s->s3->flags |= TLS1_FLAGS_KEEP_HANDSHAKE;
 680                 if (!ssl3_digest_cached_records(s)) {
 681                     s->state = SSL_ST_ERR;
 682                     return -1;
 683                 }
 684             } else {
 685                 s->state = SSL3_ST_SR_CERT_VRFY_A;
 686                 s->init_num = 0;
 687
 688                 /*
 689                  * We need to get hashes here so if there is a client cert,
 690                  * it can be verified
 691                  */
 692                 s->method->ssl3_enc->cert_verify_mac(s,
 693                                                      NID_md5,
 694                                                      &(s->s3->
 695                                                        tmp.cert_verify_md
 696                                                        [0]));
 697                 s->method->ssl3_enc->cert_verify_mac(s, NID_sha1,
 698                                                      &(s->s3->
 699                                                        tmp.cert_verify_md
 700                                                        [MD5_DIGEST_LENGTH]));
 701             }
 702             break;
 703
 704         case SSL3_ST_SR_CERT_VRFY_A:
 705         case SSL3_ST_SR_CERT_VRFY_B:
 706             ret = ssl3_get_cert_verify(s);
 707             if (ret <= 0)
 708                 goto end;
 709 #ifndef OPENSSL_NO_SCTP
 710             if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
 711                 state == SSL_ST_RENEGOTIATE)
 712                 s->state = DTLS1_SCTP_ST_SR_READ_SOCK;
 713             else
 714 #endif
 715                 s->state = SSL3_ST_SR_FINISHED_A;
 716             s->init_num = 0;
 717             break;
 718
 719         case SSL3_ST_SR_FINISHED_A:
 720         case SSL3_ST_SR_FINISHED_B:
 721             /*
 722              * Enable CCS. Receiving a CCS clears the flag, so make
 723              * sure not to re-enable it to ban duplicates. This *should* be the
 724              * first time we have received one - but we check anyway to be
 725              * cautious.
 726              * s->s3->change_cipher_spec is set when a CCS is
 727              * processed in d1_pkt.c, and remains set until
 728              * the client's Finished message is read.
 729              */
 730             if (!s->s3->change_cipher_spec)
 731                 s->d1->change_cipher_spec_ok = 1;
 732             ret = ssl3_get_finished(s, SSL3_ST_SR_FINISHED_A,
 733                                     SSL3_ST_SR_FINISHED_B);
 734             if (ret <= 0)
 735                 goto end;
 736             dtls1_stop_timer(s);
 737             if (s->hit)
 738                 s->state = SSL_ST_OK;
 739 #ifndef OPENSSL_NO_TLSEXT
 740             else if (s->tlsext_ticket_expected)
 741                 s->state = SSL3_ST_SW_SESSION_TICKET_A;
 742 #endif
 743             else
 744                 s->state = SSL3_ST_SW_CHANGE_A;
 745             s->init_num = 0;
 746             break;
 747
 748 #ifndef OPENSSL_NO_TLSEXT
 749         case SSL3_ST_SW_SESSION_TICKET_A:
 750         case SSL3_ST_SW_SESSION_TICKET_B:
 751             ret = ssl3_send_newsession_ticket(s);
 752             if (ret <= 0)
 753                 goto end;
 754             s->state = SSL3_ST_SW_CHANGE_A;
 755             s->init_num = 0;
 756             break;
 757
 758         case SSL3_ST_SW_CERT_STATUS_A:
 759         case SSL3_ST_SW_CERT_STATUS_B:
 760             ret = ssl3_send_cert_status(s);
 761             if (ret <= 0)
 762                 goto end;
 763             s->state = SSL3_ST_SW_KEY_EXCH_A;
 764             s->init_num = 0;
 765             break;
 766
 767 #endif
 768
 769         case SSL3_ST_SW_CHANGE_A:
 770         case SSL3_ST_SW_CHANGE_B:
 771
 772             s->session->cipher = s->s3->tmp.new_cipher;
 773             if (!s->method->ssl3_enc->setup_key_block(s)) {
 774                 ret = -1;
 775                 s->state = SSL_ST_ERR;
 776                 goto end;
 777             }
 778
 779             ret = dtls1_send_change_cipher_spec(s,
 780                                                 SSL3_ST_SW_CHANGE_A,
 781                                                 SSL3_ST_SW_CHANGE_B);
 782
 783             if (ret <= 0)
 784                 goto end;
 785
 786 #ifndef OPENSSL_NO_SCTP
 787             if (!s->hit) {
 788                 /*
 789                  * Change to new shared key of SCTP-Auth, will be ignored if
 790                  * no SCTP used.
 791                  */
 792                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 793                          0, NULL);
 794             }
 795 #endif
 796
 797             s->state = SSL3_ST_SW_FINISHED_A;
 798             s->init_num = 0;
 799
 800             if (!s->method->ssl3_enc->change_cipher_state(s,
 801                                                           SSL3_CHANGE_CIPHER_SERVER_WRITE))
 802             {
 803                 ret = -1;
 804                 s->state = SSL_ST_ERR;
 805                 goto end;
 806             }
 807
 808             dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
 809             break;
 810
 811         case SSL3_ST_SW_FINISHED_A:
 812         case SSL3_ST_SW_FINISHED_B:
 813             ret = ssl3_send_finished(s,
 814                                      SSL3_ST_SW_FINISHED_A,
 815                                      SSL3_ST_SW_FINISHED_B,
 816                                      s->method->
 817                                      ssl3_enc->server_finished_label,
 818                                      s->method->
 819                                      ssl3_enc->server_finished_label_len);
 820             if (ret <= 0)
 821                 goto end;
 822             s->state = SSL3_ST_SW_FLUSH;
 823             if (s->hit) {
 824                 s->s3->tmp.next_state = SSL3_ST_SR_FINISHED_A;
 825
 826 #ifndef OPENSSL_NO_SCTP
 827                 /*
 828                  * Change to new shared key of SCTP-Auth, will be ignored if
 829                  * no SCTP used.
 830                  */
 831                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 832                          0, NULL);
 833 #endif
 834             } else {
 835                 s->s3->tmp.next_state = SSL_ST_OK;
 836 #ifndef OPENSSL_NO_SCTP
 837                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 838                     s->d1->next_state = s->s3->tmp.next_state;
 839                     s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 840                 }
 841 #endif
 842             }
 843             s->init_num = 0;
 844             break;
 845
 846         case SSL_ST_OK:
 847             /* clean a few things up */
 848             ssl3_cleanup_key_block(s);
 849
 850 #if 0
 851             BUF_MEM_free(s->init_buf);
 852             s->init_buf = NULL;
 853 #endif
 854
 855             /* remove buffering on output */
 856             ssl_free_wbio_buffer(s);
 857
 858             s->init_num = 0;
 859
 860             if (s->renegotiate == 2) { /* skipped if we just sent a
 861                                         * HelloRequest */
 862                 s->renegotiate = 0;
 863                 s->new_session = 0;
 864
 865                 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
 866
 867                 s->ctx->stats.sess_accept_good++;
 868                 /* s->server=1; */
 869                 s->handshake_func = dtls1_accept;
 870
 871                 if (cb != NULL)
 872                     cb(s, SSL_CB_HANDSHAKE_DONE, 1);
 873             }
 874
 875             ret = 1;
 876
 877             /* done handshaking, next message is client hello */
 878             s->d1->handshake_read_seq = 0;
 879             /* next message is server hello */
 880             s->d1->handshake_write_seq = 0;
 881             s->d1->next_handshake_write_seq = 0;
 882             goto end;
 883             /* break; */
 884
 885         case SSL_ST_ERR:
 886         default:
 887             SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_UNKNOWN_STATE);
 888             ret = -1;
 889             goto end;
 890             /* break; */
 891         }
 892
 893         if (!s->s3->tmp.reuse_message && !skip) {
 894             if (s->debug) {
 895                 if ((ret = BIO_flush(s->wbio)) <= 0)
 896                     goto end;
 897             }
 898
 899             if ((cb != NULL) && (s->state != state)) {
 900                 new_state = s->state;
 901                 s->state = state;
 902                 cb(s, SSL_CB_ACCEPT_LOOP, 1);
 903                 s->state = new_state;
 904             }
 905         }
 906         skip = 0;
 907     }
 908  end:
 909     /* BIO_flush(s->wbio); */
 910
 911     s->in_handshake--;
 912 #ifndef OPENSSL_NO_SCTP
 913     /*
 914      * Notify SCTP BIO socket to leave handshake mode and prevent stream
 915      * identifier other than 0. Will be ignored if no SCTP is used.
 916      */
 917     BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
 918              s->in_handshake, NULL);
 919 #endif
 920
 921     if (cb != NULL)
 922         cb(s, SSL_CB_ACCEPT_EXIT, ret);
 923     return (ret);
 924 }
 925
 926 int dtls1_send_hello_verify_request(SSL *s)
 927 {
 928     unsigned int msg_len;
 929     unsigned char *msg, *buf, *p;
 930
 931     if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) {
 932         buf = (unsigned char *)s->init_buf->data;
 933
 934         msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
 935         /* Always use DTLS 1.0 version: see RFC 6347 */
 936         *(p++) = DTLS1_VERSION >> 8;
 937         *(p++) = DTLS1_VERSION & 0xFF;
 938
 939         if (s->ctx->app_gen_cookie_cb == NULL ||
 940             s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
 941                                       &(s->d1->cookie_len)) == 0) {
 942             SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,
 943                    ERR_R_INTERNAL_ERROR);
 944             s->state = SSL_ST_ERR;
 945             return 0;
 946         }
 947
 948         *(p++) = (unsigned char)s->d1->cookie_len;
 949         memcpy(p, s->d1->cookie, s->d1->cookie_len);
 950         p += s->d1->cookie_len;
 951         msg_len = p - msg;
 952
 953         dtls1_set_message_header(s, buf,
 954                                  DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0,
 955                                  msg_len);
 956
 957         s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
 958         /* number of bytes to write */
 959         s->init_num = p - buf;
 960         s->init_off = 0;
 961     }
 962
 963     /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
 964     return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
 965 }