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         if(!SSL_clear(s))
 189             return -1;
 190     }
 191
 192     s->d1->listen = listen;
 193 #ifndef OPENSSL_NO_SCTP
 194     /*
 195      * Notify SCTP BIO socket to enter handshake mode and prevent stream
 196      * identifier other than 0. Will be ignored if no SCTP is used.
 197      */
 198     BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
 199              s->in_handshake, NULL);
 200 #endif
 201
 202     if (s->cert == NULL) {
 203         SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_NO_CERTIFICATE_SET);
 204         return (-1);
 205     }
 206 #ifndef OPENSSL_NO_HEARTBEATS
 207     /*
 208      * If we're awaiting a HeartbeatResponse, pretend we already got and
 209      * don't await it anymore, because Heartbeats don't make sense during
 210      * handshakes anyway.
 211      */
 212     if (s->tlsext_hb_pending) {
 213         dtls1_stop_timer(s);
 214         s->tlsext_hb_pending = 0;
 215         s->tlsext_hb_seq++;
 216     }
 217 #endif
 218
 219     for (;;) {
 220         state = s->state;
 221
 222         switch (s->state) {
 223         case SSL_ST_RENEGOTIATE:
 224             s->renegotiate = 1;
 225             /* s->state=SSL_ST_ACCEPT; */
 226
 227         case SSL_ST_BEFORE:
 228         case SSL_ST_ACCEPT:
 229         case SSL_ST_BEFORE | SSL_ST_ACCEPT:
 230         case SSL_ST_OK | SSL_ST_ACCEPT:
 231
 232             s->server = 1;
 233             if (cb != NULL)
 234                 cb(s, SSL_CB_HANDSHAKE_START, 1);
 235
 236             if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
 237                 SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 238                 return -1;
 239             }
 240             s->type = SSL_ST_ACCEPT;
 241
 242             if (s->init_buf == NULL) {
 243                 if ((buf = BUF_MEM_new()) == NULL) {
 244                     ret = -1;
 245                     goto end;
 246                 }
 247                 if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
 248                     BUF_MEM_free(buf);
 249                     ret = -1;
 250                     goto end;
 251                 }
 252                 s->init_buf = buf;
 253             }
 254
 255             if (!ssl3_setup_buffers(s)) {
 256                 ret = -1;
 257                 goto end;
 258             }
 259
 260             s->init_num = 0;
 261             s->d1->change_cipher_spec_ok = 0;
 262             /*
 263              * Should have been reset by ssl3_get_finished, too.
 264              */
 265             s->s3->change_cipher_spec = 0;
 266
 267             if (s->state != SSL_ST_RENEGOTIATE) {
 268                 /*
 269                  * Ok, we now need to push on a buffering BIO so that the
 270                  * output is sent in a way that TCP likes :-) ...but not with
 271                  * SCTP :-)
 272                  */
 273 #ifndef OPENSSL_NO_SCTP
 274                 if (!BIO_dgram_is_sctp(SSL_get_wbio(s)))
 275 #endif
 276                     if (!ssl_init_wbio_buffer(s, 1)) {
 277                         ret = -1;
 278                         goto end;
 279                     }
 280
 281                 ssl3_init_finished_mac(s);
 282                 s->state = SSL3_ST_SR_CLNT_HELLO_A;
 283                 s->ctx->stats.sess_accept++;
 284             } else {
 285                 /*
 286                  * s->state == SSL_ST_RENEGOTIATE, we will just send a
 287                  * HelloRequest
 288                  */
 289                 s->ctx->stats.sess_accept_renegotiate++;
 290                 s->state = SSL3_ST_SW_HELLO_REQ_A;
 291             }
 292
 293             break;
 294
 295         case SSL3_ST_SW_HELLO_REQ_A:
 296         case SSL3_ST_SW_HELLO_REQ_B:
 297
 298             s->shutdown = 0;
 299             dtls1_clear_record_buffer(s);
 300             dtls1_start_timer(s);
 301             ret = ssl3_send_hello_request(s);
 302             if (ret <= 0)
 303                 goto end;
 304             s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
 305             s->state = SSL3_ST_SW_FLUSH;
 306             s->init_num = 0;
 307
 308             ssl3_init_finished_mac(s);
 309             break;
 310
 311         case SSL3_ST_SW_HELLO_REQ_C:
 312             s->state = SSL_ST_OK;
 313             break;
 314
 315         case SSL3_ST_SR_CLNT_HELLO_A:
 316         case SSL3_ST_SR_CLNT_HELLO_B:
 317         case SSL3_ST_SR_CLNT_HELLO_C:
 318
 319             s->shutdown = 0;
 320             ret = ssl3_get_client_hello(s);
 321             if (ret <= 0)
 322                 goto end;
 323             dtls1_stop_timer(s);
 324
 325             if (ret == 1 && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
 326                 s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
 327             else
 328                 s->state = SSL3_ST_SW_SRVR_HELLO_A;
 329
 330             s->init_num = 0;
 331
 332             /*
 333              * Reflect ClientHello sequence to remain stateless while
 334              * listening
 335              */
 336             if (listen) {
 337                 memcpy(s->s3->write_sequence, s->s3->read_sequence,
 338                        sizeof(s->s3->write_sequence));
 339             }
 340
 341             /* If we're just listening, stop here */
 342             if (listen && s->state == SSL3_ST_SW_SRVR_HELLO_A) {
 343                 ret = 2;
 344                 s->d1->listen = 0;
 345                 /*
 346                  * Set expected sequence numbers to continue the handshake.
 347                  */
 348                 s->d1->handshake_read_seq = 2;
 349                 s->d1->handshake_write_seq = 1;
 350                 s->d1->next_handshake_write_seq = 1;
 351                 goto end;
 352             }
 353
 354             break;
 355
 356         case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
 357         case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
 358
 359             ret = dtls1_send_hello_verify_request(s);
 360             if (ret <= 0)
 361                 goto end;
 362             s->state = SSL3_ST_SW_FLUSH;
 363             s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
 364
 365             /* HelloVerifyRequest resets Finished MAC */
 366             if (s->version != DTLS1_BAD_VER)
 367                 ssl3_init_finished_mac(s);
 368             break;
 369
 370 #ifndef OPENSSL_NO_SCTP
 371         case DTLS1_SCTP_ST_SR_READ_SOCK:
 372
 373             if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
 374                 s->s3->in_read_app_data = 2;
 375                 s->rwstate = SSL_READING;
 376                 BIO_clear_retry_flags(SSL_get_rbio(s));
 377                 BIO_set_retry_read(SSL_get_rbio(s));
 378                 ret = -1;
 379                 goto end;
 380             }
 381
 382             s->state = SSL3_ST_SR_FINISHED_A;
 383             break;
 384
 385         case DTLS1_SCTP_ST_SW_WRITE_SOCK:
 386             ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
 387             if (ret < 0)
 388                 goto end;
 389
 390             if (ret == 0) {
 391                 if (s->d1->next_state != SSL_ST_OK) {
 392                     s->s3->in_read_app_data = 2;
 393                     s->rwstate = SSL_READING;
 394                     BIO_clear_retry_flags(SSL_get_rbio(s));
 395                     BIO_set_retry_read(SSL_get_rbio(s));
 396                     ret = -1;
 397                     goto end;
 398                 }
 399             }
 400
 401             s->state = s->d1->next_state;
 402             break;
 403 #endif
 404
 405         case SSL3_ST_SW_SRVR_HELLO_A:
 406         case SSL3_ST_SW_SRVR_HELLO_B:
 407             s->renegotiate = 2;
 408             dtls1_start_timer(s);
 409             ret = ssl3_send_server_hello(s);
 410             if (ret <= 0)
 411                 goto end;
 412
 413             if (s->hit) {
 414 #ifndef OPENSSL_NO_SCTP
 415                 /*
 416                  * Add new shared key for SCTP-Auth, will be ignored if no
 417                  * SCTP used.
 418                  */
 419                 snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 420                          DTLS1_SCTP_AUTH_LABEL);
 421
 422                 SSL_export_keying_material(s, sctpauthkey,
 423                                            sizeof(sctpauthkey), labelbuffer,
 424                                            sizeof(labelbuffer), NULL, 0, 0);
 425
 426                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 427                          sizeof(sctpauthkey), sctpauthkey);
 428 #endif
 429 #ifndef OPENSSL_NO_TLSEXT
 430                 if (s->tlsext_ticket_expected)
 431                     s->state = SSL3_ST_SW_SESSION_TICKET_A;
 432                 else
 433                     s->state = SSL3_ST_SW_CHANGE_A;
 434 #else
 435                 s->state = SSL3_ST_SW_CHANGE_A;
 436 #endif
 437             } else
 438                 s->state = SSL3_ST_SW_CERT_A;
 439             s->init_num = 0;
 440             break;
 441
 442         case SSL3_ST_SW_CERT_A:
 443         case SSL3_ST_SW_CERT_B:
 444             /* Check if it is anon DH or normal PSK */
 445             if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
 446                 && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
 447                 dtls1_start_timer(s);
 448                 ret = ssl3_send_server_certificate(s);
 449                 if (ret <= 0)
 450                     goto end;
 451 #ifndef OPENSSL_NO_TLSEXT
 452                 if (s->tlsext_status_expected)
 453                     s->state = SSL3_ST_SW_CERT_STATUS_A;
 454                 else
 455                     s->state = SSL3_ST_SW_KEY_EXCH_A;
 456             } else {
 457                 skip = 1;
 458                 s->state = SSL3_ST_SW_KEY_EXCH_A;
 459             }
 460 #else
 461             } else
 462                 skip = 1;
 463
 464             s->state = SSL3_ST_SW_KEY_EXCH_A;
 465 #endif
 466             s->init_num = 0;
 467             break;
 468
 469         case SSL3_ST_SW_KEY_EXCH_A:
 470         case SSL3_ST_SW_KEY_EXCH_B:
 471             alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
 472
 473             /*
 474              * clear this, it may get reset by
 475              * send_server_key_exchange
 476              */
 477             s->s3->tmp.use_rsa_tmp = 0;
 478
 479             /*
 480              * only send if a DH key exchange or RSA but we have a sign only
 481              * certificate
 482              */
 483             if (0
 484                 /*
 485                  * PSK: send ServerKeyExchange if PSK identity hint if
 486                  * provided
 487                  */
 488 #ifndef OPENSSL_NO_PSK
 489                 || ((alg_k & SSL_kPSK) && s->ctx->psk_identity_hint)
 490 #endif
 491                 || (alg_k & (SSL_kDHE | SSL_kDHr | SSL_kDHd))
 492                 || (alg_k & SSL_kECDHE)
 493                 || ((alg_k & SSL_kRSA)
 494                     && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
 495                         || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
 496                             && EVP_PKEY_size(s->cert->pkeys
 497                                              [SSL_PKEY_RSA_ENC].privatekey) *
 498                             8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
 499                         )
 500                     )
 501                 )
 502                 ) {
 503                 dtls1_start_timer(s);
 504                 ret = ssl3_send_server_key_exchange(s);
 505                 if (ret <= 0)
 506                     goto end;
 507             } else
 508                 skip = 1;
 509
 510             s->state = SSL3_ST_SW_CERT_REQ_A;
 511             s->init_num = 0;
 512             break;
 513
 514         case SSL3_ST_SW_CERT_REQ_A:
 515         case SSL3_ST_SW_CERT_REQ_B:
 516             if (                /* don't request cert unless asked for it: */
 517                    !(s->verify_mode & SSL_VERIFY_PEER) ||
 518                    /*
 519                     * if SSL_VERIFY_CLIENT_ONCE is set, don't request cert
 520                     * during re-negotiation:
 521                     */
 522                    ((s->session->peer != NULL) &&
 523                     (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
 524                    /*
 525                     * never request cert in anonymous ciphersuites (see
 526                     * section "Certificate request" in SSL 3 drafts and in
 527                     * RFC 2246):
 528                     */
 529                    ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
 530                     /*
 531                      * ... except when the application insists on
 532                      * verification (against the specs, but s3_clnt.c accepts
 533                      * this for SSL 3)
 534                      */
 535                     !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
 536                    /*
 537                     * never request cert in Kerberos ciphersuites
 538                     */
 539                    (s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5)
 540                    /*
 541                     * With normal PSK Certificates and Certificate Requests
 542                     * are omitted
 543                     */
 544                    || (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
 545                 /* no cert request */
 546                 skip = 1;
 547                 s->s3->tmp.cert_request = 0;
 548                 s->state = SSL3_ST_SW_SRVR_DONE_A;
 549 #ifndef OPENSSL_NO_SCTP
 550                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 551                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 552                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 553                 }
 554 #endif
 555             } else {
 556                 s->s3->tmp.cert_request = 1;
 557                 dtls1_start_timer(s);
 558                 ret = ssl3_send_certificate_request(s);
 559                 if (ret <= 0)
 560                     goto end;
 561                 s->state = SSL3_ST_SW_SRVR_DONE_A;
 562 # ifndef OPENSSL_NO_SCTP
 563                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 564                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 565                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 566                 }
 567 # endif
 568                 s->init_num = 0;
 569             }
 570             break;
 571
 572         case SSL3_ST_SW_SRVR_DONE_A:
 573         case SSL3_ST_SW_SRVR_DONE_B:
 574             dtls1_start_timer(s);
 575             ret = ssl3_send_server_done(s);
 576             if (ret <= 0)
 577                 goto end;
 578             s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
 579             s->state = SSL3_ST_SW_FLUSH;
 580             s->init_num = 0;
 581             break;
 582
 583         case SSL3_ST_SW_FLUSH:
 584             s->rwstate = SSL_WRITING;
 585             if (BIO_flush(s->wbio) <= 0) {
 586                 /*
 587                  * If the write error was fatal, stop trying
 588                  */
 589                 if (!BIO_should_retry(s->wbio)) {
 590                     s->rwstate = SSL_NOTHING;
 591                     s->state = s->s3->tmp.next_state;
 592                 }
 593
 594                 ret = -1;
 595                 goto end;
 596             }
 597             s->rwstate = SSL_NOTHING;
 598             s->state = s->s3->tmp.next_state;
 599             break;
 600
 601         case SSL3_ST_SR_CERT_A:
 602         case SSL3_ST_SR_CERT_B:
 603             if (s->s3->tmp.cert_request) {
 604                 ret = ssl3_get_client_certificate(s);
 605                 if (ret <= 0)
 606                     goto end;
 607             }
 608             s->init_num = 0;
 609             s->state = SSL3_ST_SR_KEY_EXCH_A;
 610             break;
 611
 612         case SSL3_ST_SR_KEY_EXCH_A:
 613         case SSL3_ST_SR_KEY_EXCH_B:
 614             ret = ssl3_get_client_key_exchange(s);
 615             if (ret <= 0)
 616                 goto end;
 617 #ifndef OPENSSL_NO_SCTP
 618             /*
 619              * Add new shared key for SCTP-Auth, will be ignored if no SCTP
 620              * used.
 621              */
 622             snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 623                      DTLS1_SCTP_AUTH_LABEL);
 624
 625             SSL_export_keying_material(s, sctpauthkey,
 626                                        sizeof(sctpauthkey), labelbuffer,
 627                                        sizeof(labelbuffer), NULL, 0, 0);
 628
 629             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 630                      sizeof(sctpauthkey), sctpauthkey);
 631 #endif
 632
 633             s->state = SSL3_ST_SR_CERT_VRFY_A;
 634             s->init_num = 0;
 635
 636             if (ret == 2) {
 637                 /*
 638                  * For the ECDH ciphersuites when the client sends its ECDH
 639                  * pub key in a certificate, the CertificateVerify message is
 640                  * not sent.
 641                  */
 642                 s->state = SSL3_ST_SR_FINISHED_A;
 643                 s->init_num = 0;
 644             } else if (SSL_USE_SIGALGS(s)) {
 645                 s->state = SSL3_ST_SR_CERT_VRFY_A;
 646                 s->init_num = 0;
 647                 if (!s->session->peer)
 648                     break;
 649                 if (!s->s3->handshake_buffer) {
 650                     SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 651                     return -1;
 652                 }
 653                 /*
 654                  * For sigalgs freeze the handshake buffer. If we support
 655                  * extms we've done this already.
 656                  */
 657                 if (!(s->s3->flags & SSL_SESS_FLAG_EXTMS)) {
 658                     s->s3->flags |= TLS1_FLAGS_KEEP_HANDSHAKE;
 659                     if (!ssl3_digest_cached_records(s))
 660                         return -1;
 661                 }
 662             } else {
 663                 s->state = SSL3_ST_SR_CERT_VRFY_A;
 664                 s->init_num = 0;
 665
 666                 /*
 667                  * We need to get hashes here so if there is a client cert,
 668                  * it can be verified
 669                  */
 670                 s->method->ssl3_enc->cert_verify_mac(s,
 671                                                      NID_md5,
 672                                                      &(s->s3->
 673                                                        tmp.cert_verify_md
 674                                                        [0]));
 675                 s->method->ssl3_enc->cert_verify_mac(s, NID_sha1,
 676                                                      &(s->s3->
 677                                                        tmp.cert_verify_md
 678                                                        [MD5_DIGEST_LENGTH]));
 679             }
 680             break;
 681
 682         case SSL3_ST_SR_CERT_VRFY_A:
 683         case SSL3_ST_SR_CERT_VRFY_B:
 684             /*
 685              * This *should* be the first time we enable CCS, but be
 686              * extra careful about surrounding code changes. We need
 687              * to set this here because we don't know if we're
 688              * expecting a CertificateVerify or not.
 689              */
 690             if (!s->s3->change_cipher_spec)
 691                 s->d1->change_cipher_spec_ok = 1;
 692             /* we should decide if we expected this one */
 693             ret = ssl3_get_cert_verify(s);
 694             if (ret <= 0)
 695                 goto end;
 696 #ifndef OPENSSL_NO_SCTP
 697             if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
 698                 state == SSL_ST_RENEGOTIATE)
 699                 s->state = DTLS1_SCTP_ST_SR_READ_SOCK;
 700             else
 701 #endif
 702                 s->state = SSL3_ST_SR_FINISHED_A;
 703             s->init_num = 0;
 704             break;
 705
 706         case SSL3_ST_SR_FINISHED_A:
 707         case SSL3_ST_SR_FINISHED_B:
 708             /*
 709              * Enable CCS for resumed handshakes.
 710              * In a full handshake, we end up here through
 711              * SSL3_ST_SR_CERT_VRFY_B, so change_cipher_spec_ok was
 712              * already set. Receiving a CCS clears the flag, so make
 713              * sure not to re-enable it to ban duplicates.
 714              * s->s3->change_cipher_spec is set when a CCS is
 715              * processed in d1_pkt.c, and remains set until
 716              * the client's Finished message is read.
 717              */
 718             if (!s->s3->change_cipher_spec)
 719                 s->d1->change_cipher_spec_ok = 1;
 720             ret = ssl3_get_finished(s, SSL3_ST_SR_FINISHED_A,
 721                                     SSL3_ST_SR_FINISHED_B);
 722             if (ret <= 0)
 723                 goto end;
 724             dtls1_stop_timer(s);
 725             if (s->hit)
 726                 s->state = SSL_ST_OK;
 727 #ifndef OPENSSL_NO_TLSEXT
 728             else if (s->tlsext_ticket_expected)
 729                 s->state = SSL3_ST_SW_SESSION_TICKET_A;
 730 #endif
 731             else
 732                 s->state = SSL3_ST_SW_CHANGE_A;
 733             s->init_num = 0;
 734             break;
 735
 736 #ifndef OPENSSL_NO_TLSEXT
 737         case SSL3_ST_SW_SESSION_TICKET_A:
 738         case SSL3_ST_SW_SESSION_TICKET_B:
 739             ret = ssl3_send_newsession_ticket(s);
 740             if (ret <= 0)
 741                 goto end;
 742             s->state = SSL3_ST_SW_CHANGE_A;
 743             s->init_num = 0;
 744             break;
 745
 746         case SSL3_ST_SW_CERT_STATUS_A:
 747         case SSL3_ST_SW_CERT_STATUS_B:
 748             ret = ssl3_send_cert_status(s);
 749             if (ret <= 0)
 750                 goto end;
 751             s->state = SSL3_ST_SW_KEY_EXCH_A;
 752             s->init_num = 0;
 753             break;
 754
 755 #endif
 756
 757         case SSL3_ST_SW_CHANGE_A:
 758         case SSL3_ST_SW_CHANGE_B:
 759
 760             s->session->cipher = s->s3->tmp.new_cipher;
 761             if (!s->method->ssl3_enc->setup_key_block(s)) {
 762                 ret = -1;
 763                 goto end;
 764             }
 765
 766             ret = dtls1_send_change_cipher_spec(s,
 767                                                 SSL3_ST_SW_CHANGE_A,
 768                                                 SSL3_ST_SW_CHANGE_B);
 769
 770             if (ret <= 0)
 771                 goto end;
 772
 773 #ifndef OPENSSL_NO_SCTP
 774             if (!s->hit) {
 775                 /*
 776                  * Change to new shared key of SCTP-Auth, will be ignored if
 777                  * no SCTP used.
 778                  */
 779                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 780                          0, NULL);
 781             }
 782 #endif
 783
 784             s->state = SSL3_ST_SW_FINISHED_A;
 785             s->init_num = 0;
 786
 787             if (!s->method->ssl3_enc->change_cipher_state(s,
 788                                                           SSL3_CHANGE_CIPHER_SERVER_WRITE))
 789             {
 790                 ret = -1;
 791                 goto end;
 792             }
 793
 794             dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
 795             break;
 796
 797         case SSL3_ST_SW_FINISHED_A:
 798         case SSL3_ST_SW_FINISHED_B:
 799             ret = ssl3_send_finished(s,
 800                                      SSL3_ST_SW_FINISHED_A,
 801                                      SSL3_ST_SW_FINISHED_B,
 802                                      s->method->
 803                                      ssl3_enc->server_finished_label,
 804                                      s->method->
 805                                      ssl3_enc->server_finished_label_len);
 806             if (ret <= 0)
 807                 goto end;
 808             s->state = SSL3_ST_SW_FLUSH;
 809             if (s->hit) {
 810                 s->s3->tmp.next_state = SSL3_ST_SR_FINISHED_A;
 811
 812 #ifndef OPENSSL_NO_SCTP
 813                 /*
 814                  * Change to new shared key of SCTP-Auth, will be ignored if
 815                  * no SCTP used.
 816                  */
 817                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 818                          0, NULL);
 819 #endif
 820             } else {
 821                 s->s3->tmp.next_state = SSL_ST_OK;
 822 #ifndef OPENSSL_NO_SCTP
 823                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 824                     s->d1->next_state = s->s3->tmp.next_state;
 825                     s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 826                 }
 827 #endif
 828             }
 829             s->init_num = 0;
 830             break;
 831
 832         case SSL_ST_OK:
 833             /* clean a few things up */
 834             ssl3_cleanup_key_block(s);
 835
 836             /* remove buffering on output */
 837             ssl_free_wbio_buffer(s);
 838
 839             s->init_num = 0;
 840
 841             if (s->renegotiate == 2) { /* skipped if we just sent a
 842                                         * HelloRequest */
 843                 s->renegotiate = 0;
 844                 s->new_session = 0;
 845
 846                 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
 847
 848                 s->ctx->stats.sess_accept_good++;
 849                 /* s->server=1; */
 850                 s->handshake_func = dtls1_accept;
 851
 852                 if (cb != NULL)
 853                     cb(s, SSL_CB_HANDSHAKE_DONE, 1);
 854             }
 855
 856             ret = 1;
 857
 858             /* done handshaking, next message is client hello */
 859             s->d1->handshake_read_seq = 0;
 860             /* next message is server hello */
 861             s->d1->handshake_write_seq = 0;
 862             s->d1->next_handshake_write_seq = 0;
 863             goto end;
 864             /* break; */
 865
 866         default:
 867             SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_UNKNOWN_STATE);
 868             ret = -1;
 869             goto end;
 870             /* break; */
 871         }
 872
 873         if (!s->s3->tmp.reuse_message && !skip) {
 874             if (s->debug) {
 875                 if ((ret = BIO_flush(s->wbio)) <= 0)
 876                     goto end;
 877             }
 878
 879             if ((cb != NULL) && (s->state != state)) {
 880                 new_state = s->state;
 881                 s->state = state;
 882                 cb(s, SSL_CB_ACCEPT_LOOP, 1);
 883                 s->state = new_state;
 884             }
 885         }
 886         skip = 0;
 887     }
 888  end:
 889     /* BIO_flush(s->wbio); */
 890
 891     s->in_handshake--;
 892 #ifndef OPENSSL_NO_SCTP
 893     /*
 894      * Notify SCTP BIO socket to leave handshake mode and prevent stream
 895      * identifier other than 0. Will be ignored if no SCTP is used.
 896      */
 897     BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
 898              s->in_handshake, NULL);
 899 #endif
 900
 901     if (cb != NULL)
 902         cb(s, SSL_CB_ACCEPT_EXIT, ret);
 903     return (ret);
 904 }
 905
 906 int dtls1_send_hello_verify_request(SSL *s)
 907 {
 908     unsigned int msg_len;
 909     unsigned char *msg, *buf, *p;
 910
 911     if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) {
 912         buf = (unsigned char *)s->init_buf->data;
 913
 914         msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
 915         /* Always use DTLS 1.0 version: see RFC 6347 */
 916         *(p++) = DTLS1_VERSION >> 8;
 917         *(p++) = DTLS1_VERSION & 0xFF;
 918
 919         if (s->ctx->app_gen_cookie_cb == NULL ||
 920             s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
 921                                       &(s->d1->cookie_len)) == 0) {
 922             SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,
 923                    ERR_R_INTERNAL_ERROR);
 924             return 0;
 925         }
 926
 927         *(p++) = (unsigned char)s->d1->cookie_len;
 928         memcpy(p, s->d1->cookie, s->d1->cookie_len);
 929         p += s->d1->cookie_len;
 930         msg_len = p - msg;
 931
 932         dtls1_set_message_header(s, buf,
 933                                  DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0,
 934                                  msg_len);
 935
 936         s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
 937         /* number of bytes to write */
 938         s->init_num = p - buf;
 939         s->init_off = 0;
 940     }
 941
 942     /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
 943     return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
 944 }