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