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