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,
 147                         DTLSv1_enc_data)
 148
 149 IMPLEMENT_dtls1_meth_func(DTLS1_2_VERSION,
 150                         DTLSv1_2_server_method,
 151                         dtls1_accept,
 152                         ssl_undefined_function,
 153                         dtls1_get_server_method,
 154                         DTLSv1_2_enc_data)
 155
 156 IMPLEMENT_dtls1_meth_func(DTLS_ANY_VERSION,
 157                         DTLS_server_method,
 158                         dtls1_accept,
 159                         ssl_undefined_function,
 160                         dtls1_get_server_method,
 161                         DTLSv1_2_enc_data)
 162
 163 int dtls1_accept(SSL *s)
 164         {
 165         BUF_MEM *buf;
 166         unsigned long Time=(unsigned long)time(NULL);
 167         void (*cb)(const SSL *ssl,int type,int val)=NULL;
 168         unsigned long alg_k;
 169         int ret= -1;
 170         int new_state,state,skip=0;
 171         int listen;
 172 #ifndef OPENSSL_NO_SCTP
 173         unsigned char sctpauthkey[64];
 174         char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
 175 #endif
 176
 177         RAND_add(&Time,sizeof(Time),0);
 178         ERR_clear_error();
 179         clear_sys_error();
 180
 181         if (s->info_callback != NULL)
 182                 cb=s->info_callback;
 183         else if (s->ctx->info_callback != NULL)
 184                 cb=s->ctx->info_callback;
 185
 186         listen = s->d1->listen;
 187
 188         /* init things to blank */
 189         s->in_handshake++;
 190         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
 191
 192         s->d1->listen = listen;
 193 #ifndef OPENSSL_NO_SCTP
 194         /* Notify SCTP BIO socket to enter handshake
 195          * mode and prevent stream identifier other
 196          * 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, s->in_handshake, NULL);
 199 #endif
 200
 201         if (s->cert == NULL)
 202                 {
 203                 SSLerr(SSL_F_DTLS1_ACCEPT,SSL_R_NO_CERTIFICATE_SET);
 204                 return(-1);
 205                 }
 206
 207 #ifndef OPENSSL_NO_HEARTBEATS
 208         /* If we're awaiting a HeartbeatResponse, pretend we
 209          * already got and don't await it anymore, because
 210          * Heartbeats don't make sense during handshakes anyway.
 211          */
 212         if (s->tlsext_hb_pending)
 213                 {
 214                 dtls1_stop_timer(s);
 215                 s->tlsext_hb_pending = 0;
 216                 s->tlsext_hb_seq++;
 217                 }
 218 #endif
 219
 220         for (;;)
 221                 {
 222                 state=s->state;
 223
 224                 switch (s->state)
 225                         {
 226                 case SSL_ST_RENEGOTIATE:
 227                         s->renegotiate=1;
 228                         /* s->state=SSL_ST_ACCEPT; */
 229
 230                 case SSL_ST_BEFORE:
 231                 case SSL_ST_ACCEPT:
 232                 case SSL_ST_BEFORE|SSL_ST_ACCEPT:
 233                 case SSL_ST_OK|SSL_ST_ACCEPT:
 234
 235                         s->server=1;
 236                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
 237
 238                         if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00))
 239                                 {
 240                                 SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 241                                 return -1;
 242                                 }
 243                         s->type=SSL_ST_ACCEPT;
 244
 245                         if (s->init_buf == NULL)
 246                                 {
 247                                 if ((buf=BUF_MEM_new()) == NULL)
 248                                         {
 249                                         ret= -1;
 250                                         goto end;
 251                                         }
 252                                 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
 253                                         {
 254                                         ret= -1;
 255                                         goto end;
 256                                         }
 257                                 s->init_buf=buf;
 258                                 }
 259
 260                         if (!ssl3_setup_buffers(s))
 261                                 {
 262                                 ret= -1;
 263                                 goto end;
 264                                 }
 265
 266                         s->init_num=0;
 267                         s->d1->change_cipher_spec_ok = 0;
 268                         /* Should have been reset by ssl3_get_finished, too. */
 269                         s->s3->change_cipher_spec = 0;
 270
 271                         if (s->state != SSL_ST_RENEGOTIATE)
 272                                 {
 273                                 /* Ok, we now need to push on a buffering BIO so that
 274                                  * the output is sent in a way that TCP likes :-)
 275                                  * ...but not with SCTP :-)
 276                                  */
 277 #ifndef OPENSSL_NO_SCTP
 278                                 if (!BIO_dgram_is_sctp(SSL_get_wbio(s)))
 279 #endif
 280                                         if (!ssl_init_wbio_buffer(s,1)) { ret= -1; goto end; }
 281
 282                                 ssl3_init_finished_mac(s);
 283                                 s->state=SSL3_ST_SR_CLNT_HELLO_A;
 284                                 s->ctx->stats.sess_accept++;
 285                                 }
 286                         else
 287                                 {
 288                                 /* s->state == SSL_ST_RENEGOTIATE,
 289                                  * we will just send a HelloRequest */
 290                                 s->ctx->stats.sess_accept_renegotiate++;
 291                                 s->state=SSL3_ST_SW_HELLO_REQ_A;
 292                                 }
 293
 294                         break;
 295
 296                 case SSL3_ST_SW_HELLO_REQ_A:
 297                 case SSL3_ST_SW_HELLO_REQ_B:
 298
 299                         s->shutdown=0;
 300                         dtls1_clear_record_buffer(s);
 301                         dtls1_start_timer(s);
 302                         ret=ssl3_send_hello_request(s);
 303                         if (ret <= 0) 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) goto end;
 322                         dtls1_stop_timer(s);
 323
 324                         if (ret == 1 && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
 325                                 s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
 326                         else
 327                                 s->state = SSL3_ST_SW_SRVR_HELLO_A;
 328
 329                         s->init_num=0;
 330
 331                         /* Reflect ClientHello sequence to remain stateless while listening */
 332                         if (listen)
 333                                 {
 334                                 memcpy(s->s3->write_sequence, s->s3->read_sequence, sizeof(s->s3->write_sequence));
 335                                 }
 336
 337                         /* If we're just listening, stop here */
 338                         if (listen && s->state == SSL3_ST_SW_SRVR_HELLO_A)
 339                                 {
 340                                 ret = 2;
 341                                 s->d1->listen = 0;
 342                                 /* Set expected sequence numbers
 343                                  * to continue the handshake.
 344                                  */
 345                                 s->d1->handshake_read_seq = 2;
 346                                 s->d1->handshake_write_seq = 1;
 347                                 s->d1->next_handshake_write_seq = 1;
 348                                 goto end;
 349                                 }
 350
 351                         break;
 352
 353                 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
 354                 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
 355
 356                         ret = dtls1_send_hello_verify_request(s);
 357                         if ( ret <= 0) goto end;
 358                         s->state=SSL3_ST_SW_FLUSH;
 359                         s->s3->tmp.next_state=SSL3_ST_SR_CLNT_HELLO_A;
 360
 361                         /* HelloVerifyRequest resets Finished MAC */
 362                         if (s->version != DTLS1_BAD_VER)
 363                                 ssl3_init_finished_mac(s);
 364                         break;
 365
 366 #ifndef OPENSSL_NO_SCTP
 367                 case DTLS1_SCTP_ST_SR_READ_SOCK:
 368
 369                         if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
 370                                 {
 371                                 s->s3->in_read_app_data=2;
 372                                 s->rwstate=SSL_READING;
 373                                 BIO_clear_retry_flags(SSL_get_rbio(s));
 374                                 BIO_set_retry_read(SSL_get_rbio(s));
 375                                 ret = -1;
 376                                 goto end;
 377                                 }
 378
 379                         s->state=SSL3_ST_SR_FINISHED_A;
 380                         break;
 381
 382                 case DTLS1_SCTP_ST_SW_WRITE_SOCK:
 383                         ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
 384                         if (ret < 0) goto end;
 385
 386                         if (ret == 0)
 387                                 {
 388                                 if (s->d1->next_state != SSL_ST_OK)
 389                                         {
 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) goto end;
 409
 410                         if (s->hit)
 411                                 {
 412 #ifndef OPENSSL_NO_SCTP
 413                                 /* Add new shared key for SCTP-Auth,
 414                                  * will be ignored if no SCTP used.
 415                                  */
 416                                 snprintf((char*) labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 417                                          DTLS1_SCTP_AUTH_LABEL);
 418
 419                                 SSL_export_keying_material(s, sctpauthkey,
 420                                                            sizeof(sctpauthkey), labelbuffer,
 421                                                            sizeof(labelbuffer), NULL, 0, 0);
 422
 423                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 424                          sizeof(sctpauthkey), sctpauthkey);
 425 #endif
 426 #ifndef OPENSSL_NO_TLSEXT
 427                                 if (s->tlsext_ticket_expected)
 428                                         s->state=SSL3_ST_SW_SESSION_TICKET_A;
 429                                 else
 430                                         s->state=SSL3_ST_SW_CHANGE_A;
 431 #else
 432                                 s->state=SSL3_ST_SW_CHANGE_A;
 433 #endif
 434                                 }
 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                                 {
 446                                 dtls1_start_timer(s);
 447                                 ret=ssl3_send_server_certificate(s);
 448                                 if (ret <= 0) 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                                 }
 455                         else
 456                                 {
 457                                 skip = 1;
 458                                 s->state=SSL3_ST_SW_KEY_EXCH_A;
 459                                 }
 460 #else
 461                                 }
 462                         else
 463                                 skip=1;
 464
 465                         s->state=SSL3_ST_SW_KEY_EXCH_A;
 466 #endif
 467                         s->init_num=0;
 468                         break;
 469
 470                 case SSL3_ST_SW_KEY_EXCH_A:
 471                 case SSL3_ST_SW_KEY_EXCH_B:
 472                         alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
 473
 474                         /* clear this, it may get reset by
 475                          * send_server_key_exchange */
 476                         if ((s->options & SSL_OP_EPHEMERAL_RSA)
 477 #ifndef OPENSSL_NO_KRB5
 478                                 && !(alg_k & SSL_kKRB5)
 479 #endif /* OPENSSL_NO_KRB5 */
 480                                 )
 481                                 /* option SSL_OP_EPHEMERAL_RSA sends temporary RSA key
 482                                  * even when forbidden by protocol specs
 483                                  * (handshake may fail as clients are not required to
 484                                  * be able to handle this) */
 485                                 s->s3->tmp.use_rsa_tmp=1;
 486                         else
 487                                 s->s3->tmp.use_rsa_tmp=0;
 488
 489                         /* only send if a DH key exchange or
 490                          * RSA but we have a sign only certificate */
 491                         if (s->s3->tmp.use_rsa_tmp
 492                         /* PSK: send ServerKeyExchange if PSK identity
 493                          * hint if provided */
 494 #ifndef OPENSSL_NO_PSK
 495                             || ((alg_k & SSL_kPSK) && s->ctx->psk_identity_hint)
 496 #endif
 497                             || (alg_k & (SSL_kDHE|SSL_kDHr|SSL_kDHd))
 498                             || (alg_k & SSL_kECDHE)
 499                             || ((alg_k & SSL_kRSA)
 500                                 && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
 501                                     || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
 502                                         && EVP_PKEY_size(s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey)*8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
 503                                         )
 504                                     )
 505                                 )
 506                             )
 507                                 {
 508                                 dtls1_start_timer(s);
 509                                 ret=ssl3_send_server_key_exchange(s);
 510                                 if (ret <= 0) goto end;
 511                                 }
 512                         else
 513                                 skip=1;
 514
 515                         s->state=SSL3_ST_SW_CERT_REQ_A;
 516                         s->init_num=0;
 517                         break;
 518
 519                 case SSL3_ST_SW_CERT_REQ_A:
 520                 case SSL3_ST_SW_CERT_REQ_B:
 521                         if (/* don't request cert unless asked for it: */
 522                                 !(s->verify_mode & SSL_VERIFY_PEER) ||
 523                                 /* if SSL_VERIFY_CLIENT_ONCE is set,
 524                                  * don't request cert during re-negotiation: */
 525                                 ((s->session->peer != NULL) &&
 526                                  (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
 527                                 /* never request cert in anonymous ciphersuites
 528                                  * (see section "Certificate request" in SSL 3 drafts
 529                                  * and in RFC 2246): */
 530                                 ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
 531                                  /* ... except when the application insists on verification
 532                                   * (against the specs, but s3_clnt.c accepts this for SSL 3) */
 533                                  !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
 534                                  /* never request cert in Kerberos ciphersuites */
 535                                 (s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5)
 536                                 /* With normal PSK Certificates and
 537                                  * Certificate Requests are omitted */
 538                                 || (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK))
 539                                 {
 540                                 /* no cert request */
 541                                 skip=1;
 542                                 s->s3->tmp.cert_request=0;
 543                                 s->state=SSL3_ST_SW_SRVR_DONE_A;
 544 #ifndef OPENSSL_NO_SCTP
 545                                 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 546                                         {
 547                                         s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 548                                         s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 549                                         }
 550 #endif
 551                                 }
 552                         else
 553                                 {
 554                                 s->s3->tmp.cert_request=1;
 555                                 dtls1_start_timer(s);
 556                                 ret=ssl3_send_certificate_request(s);
 557                                 if (ret <= 0) goto end;
 558 #ifndef NETSCAPE_HANG_BUG
 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                                         {
 563                                         s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 564                                         s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 565                                         }
 566 #endif
 567 #else
 568                                 s->state=SSL3_ST_SW_FLUSH;
 569                                 s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
 570 #ifndef OPENSSL_NO_SCTP
 571                                 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 572                                         {
 573                                         s->d1->next_state = s->s3->tmp.next_state;
 574                                         s->s3->tmp.next_state=DTLS1_SCTP_ST_SW_WRITE_SOCK;
 575                                         }
 576 #endif
 577 #endif
 578                                 s->init_num=0;
 579                                 }
 580                         break;
 581
 582                 case SSL3_ST_SW_SRVR_DONE_A:
 583                 case SSL3_ST_SW_SRVR_DONE_B:
 584                         dtls1_start_timer(s);
 585                         ret=ssl3_send_server_done(s);
 586                         if (ret <= 0) goto end;
 587                         s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
 588                         s->state=SSL3_ST_SW_FLUSH;
 589                         s->init_num=0;
 590                         break;
 591
 592                 case SSL3_ST_SW_FLUSH:
 593                         s->rwstate=SSL_WRITING;
 594                         if (BIO_flush(s->wbio) <= 0)
 595                                 {
 596                                 /* If the write error was fatal, stop trying */
 597                                 if (!BIO_should_retry(s->wbio))
 598                                         {
 599                                         s->rwstate=SSL_NOTHING;
 600                                         s->state=s->s3->tmp.next_state;
 601                                         }
 602
 603                                 ret= -1;
 604                                 goto end;
 605                                 }
 606                         s->rwstate=SSL_NOTHING;
 607                         s->state=s->s3->tmp.next_state;
 608                         break;
 609
 610                 case SSL3_ST_SR_CERT_A:
 611                 case SSL3_ST_SR_CERT_B:
 612                         /* Check for second client hello (MS SGC) */
 613                         ret = ssl3_check_client_hello(s);
 614                         if (ret <= 0)
 615                                 goto end;
 616                         if (ret == 2)
 617                                 {
 618                                 dtls1_stop_timer(s);
 619                                 s->state = SSL3_ST_SR_CLNT_HELLO_C;
 620                                 }
 621                         else {
 622                                 if (s->s3->tmp.cert_request)
 623                                         {
 624                                         ret=ssl3_get_client_certificate(s);
 625                                         if (ret <= 0) goto end;
 626                                         }
 627                                 s->init_num=0;
 628                                 s->state=SSL3_ST_SR_KEY_EXCH_A;
 629                         }
 630                         break;
 631
 632                 case SSL3_ST_SR_KEY_EXCH_A:
 633                 case SSL3_ST_SR_KEY_EXCH_B:
 634                         ret=ssl3_get_client_key_exchange(s);
 635                         if (ret <= 0) goto end;
 636 #ifndef OPENSSL_NO_SCTP
 637                         /* Add new shared key for SCTP-Auth,
 638                          * will be ignored if no SCTP used.
 639                          */
 640                         snprintf((char *) labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 641                                  DTLS1_SCTP_AUTH_LABEL);
 642
 643                         SSL_export_keying_material(s, sctpauthkey,
 644                                                    sizeof(sctpauthkey), labelbuffer,
 645                                                    sizeof(labelbuffer), NULL, 0, 0);
 646
 647                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 648                                  sizeof(sctpauthkey), sctpauthkey);
 649 #endif
 650
 651                         s->state=SSL3_ST_SR_CERT_VRFY_A;
 652                         s->init_num=0;
 653
 654                         if (ret == 2)
 655                                 {
 656                                 /* For the ECDH ciphersuites when
 657                                  * the client sends its ECDH pub key in
 658                                  * a certificate, the CertificateVerify
 659                                  * message is not sent.
 660                                  */
 661                                 s->state=SSL3_ST_SR_FINISHED_A;
 662                                 s->init_num = 0;
 663                                 }
 664                         else if (SSL_USE_SIGALGS(s))
 665                                 {
 666                                 s->state=SSL3_ST_SR_CERT_VRFY_A;
 667                                 s->init_num=0;
 668                                 if (!s->session->peer)
 669                                         break;
 670                                 /* For sigalgs freeze the handshake buffer
 671                                  * at this point and digest cached records.
 672                                  */
 673                                 if (!s->s3->handshake_buffer)
 674                                         {
 675                                         SSLerr(SSL_F_DTLS1_ACCEPT,ERR_R_INTERNAL_ERROR);
 676                                         return -1;
 677                                         }
 678                                 s->s3->flags |= TLS1_FLAGS_KEEP_HANDSHAKE;
 679                                 if (!ssl3_digest_cached_records(s))
 680                                         return -1;
 681                                 }
 682                         else
 683                                 {
 684                                 s->state=SSL3_ST_SR_CERT_VRFY_A;
 685                                 s->init_num=0;
 686
 687                                 /* We need to get hashes here so if there is
 688                                  * a client cert, it can be verified */
 689                                 s->method->ssl3_enc->cert_verify_mac(s,
 690                                         NID_md5,
 691                                         &(s->s3->tmp.cert_verify_md[0]));
 692                                 s->method->ssl3_enc->cert_verify_mac(s,
 693                                         NID_sha1,
 694                                         &(s->s3->tmp.cert_verify_md[MD5_DIGEST_LENGTH]));
 695                                 }
 696                         break;
 697
 698                 case SSL3_ST_SR_CERT_VRFY_A:
 699                 case SSL3_ST_SR_CERT_VRFY_B:
 700                         /*
 701                          * This *should* be the first time we enable CCS, but be
 702                          * extra careful about surrounding code changes. We need
 703                          * to set this here because we don't know if we're
 704                          * expecting a CertificateVerify or not.
 705                          */
 706                         if (!s->s3->change_cipher_spec)
 707                                 s->d1->change_cipher_spec_ok = 1;
 708                         /* we should decide if we expected this one */
 709                         ret=ssl3_get_cert_verify(s);
 710                         if (ret <= 0) goto end;
 711 #ifndef OPENSSL_NO_SCTP
 712                         if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
 713                             state == SSL_ST_RENEGOTIATE)
 714                                 s->state=DTLS1_SCTP_ST_SR_READ_SOCK;
 715                         else
 716 #endif
 717                                 s->state=SSL3_ST_SR_FINISHED_A;
 718                         s->init_num=0;
 719                         break;
 720
 721                 case SSL3_ST_SR_FINISHED_A:
 722                 case SSL3_ST_SR_FINISHED_B:
 723                         /*
 724                          * Enable CCS for resumed handshakes.
 725                          * In a full handshake, we end up here through
 726                          * SSL3_ST_SR_CERT_VRFY_B, so change_cipher_spec_ok was
 727                          * already set. Receiving a CCS clears the flag, so make
 728                          * sure not to re-enable it to ban duplicates.
 729                          * s->s3->change_cipher_spec is set when a CCS is
 730                          * processed in d1_pkt.c, and remains set until
 731                          * the client's Finished message is read.
 732                          */
 733                         if (!s->s3->change_cipher_spec)
 734                                 s->d1->change_cipher_spec_ok = 1;
 735                         ret=ssl3_get_finished(s,SSL3_ST_SR_FINISHED_A,
 736                                 SSL3_ST_SR_FINISHED_B);
 737                         if (ret <= 0) goto end;
 738                         dtls1_stop_timer(s);
 739                         if (s->hit)
 740                                 s->state=SSL_ST_OK;
 741 #ifndef OPENSSL_NO_TLSEXT
 742                         else if (s->tlsext_ticket_expected)
 743                                 s->state=SSL3_ST_SW_SESSION_TICKET_A;
 744 #endif
 745                         else
 746                                 s->state=SSL3_ST_SW_CHANGE_A;
 747                         s->init_num=0;
 748                         break;
 749
 750 #ifndef OPENSSL_NO_TLSEXT
 751                 case SSL3_ST_SW_SESSION_TICKET_A:
 752                 case SSL3_ST_SW_SESSION_TICKET_B:
 753                         ret=ssl3_send_newsession_ticket(s);
 754                         if (ret <= 0) goto end;
 755                         s->state=SSL3_ST_SW_CHANGE_A;
 756                         s->init_num=0;
 757                         break;
 758
 759                 case SSL3_ST_SW_CERT_STATUS_A:
 760                 case SSL3_ST_SW_CERT_STATUS_B:
 761                         ret=ssl3_send_cert_status(s);
 762                         if (ret <= 0) goto end;
 763                         s->state=SSL3_ST_SW_KEY_EXCH_A;
 764                         s->init_num=0;
 765                         break;
 766
 767 #endif
 768
 769                 case SSL3_ST_SW_CHANGE_A:
 770                 case SSL3_ST_SW_CHANGE_B:
 771
 772                         s->session->cipher=s->s3->tmp.new_cipher;
 773                         if (!s->method->ssl3_enc->setup_key_block(s))
 774                                 { ret= -1; goto end; }
 775
 776                         ret=dtls1_send_change_cipher_spec(s,
 777                                 SSL3_ST_SW_CHANGE_A,SSL3_ST_SW_CHANGE_B);
 778
 779                         if (ret <= 0) goto end;
 780
 781 #ifndef OPENSSL_NO_SCTP
 782                         if (!s->hit)
 783                                 {
 784                                 /* Change to new shared key of SCTP-Auth,
 785                                  * will be ignored if no SCTP used.
 786                                  */
 787                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY, 0, NULL);
 788                                 }
 789 #endif
 790
 791                         s->state=SSL3_ST_SW_FINISHED_A;
 792                         s->init_num=0;
 793
 794                         if (!s->method->ssl3_enc->change_cipher_state(s,
 795                                 SSL3_CHANGE_CIPHER_SERVER_WRITE))
 796                                 {
 797                                 ret= -1;
 798                                 goto end;
 799                                 }
 800
 801                         dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
 802                         break;
 803
 804                 case SSL3_ST_SW_FINISHED_A:
 805                 case SSL3_ST_SW_FINISHED_B:
 806                         ret=ssl3_send_finished(s,
 807                                 SSL3_ST_SW_FINISHED_A,SSL3_ST_SW_FINISHED_B,
 808                                 s->method->ssl3_enc->server_finished_label,
 809                                 s->method->ssl3_enc->server_finished_label_len);
 810                         if (ret <= 0) goto end;
 811                         s->state=SSL3_ST_SW_FLUSH;
 812                         if (s->hit)
 813                                 {
 814                                 s->s3->tmp.next_state=SSL3_ST_SR_FINISHED_A;
 815
 816 #ifndef OPENSSL_NO_SCTP
 817                                 /* Change to new shared key of SCTP-Auth,
 818                                  * will be ignored if no SCTP used.
 819                                  */
 820                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY, 0, NULL);
 821 #endif
 822                                 }
 823                         else
 824                                 {
 825                                 s->s3->tmp.next_state=SSL_ST_OK;
 826 #ifndef OPENSSL_NO_SCTP
 827                                 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
 828                                         {
 829                                         s->d1->next_state = s->s3->tmp.next_state;
 830                                         s->s3->tmp.next_state=DTLS1_SCTP_ST_SW_WRITE_SOCK;
 831                                         }
 832 #endif
 833                                 }
 834                         s->init_num=0;
 835                         break;
 836
 837                 case SSL_ST_OK:
 838                         /* clean a few things up */
 839                         ssl3_cleanup_key_block(s);
 840
 841 #if 0
 842                         BUF_MEM_free(s->init_buf);
 843                         s->init_buf=NULL;
 844 #endif
 845
 846                         /* remove buffering on output */
 847                         ssl_free_wbio_buffer(s);
 848
 849                         s->init_num=0;
 850
 851                         if (s->renegotiate == 2) /* skipped if we just sent a HelloRequest */
 852                                 {
 853                                 s->renegotiate=0;
 854                                 s->new_session=0;
 855
 856                                 ssl_update_cache(s,SSL_SESS_CACHE_SERVER);
 857
 858                                 s->ctx->stats.sess_accept_good++;
 859                                 /* s->server=1; */
 860                                 s->handshake_func=dtls1_accept;
 861
 862                                 if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_DONE,1);
 863                                 }
 864
 865                         ret = 1;
 866
 867                         /* done handshaking, next message is client hello */
 868                         s->d1->handshake_read_seq = 0;
 869                         /* next message is server hello */
 870                         s->d1->handshake_write_seq = 0;
 871                         s->d1->next_handshake_write_seq = 0;
 872                         goto end;
 873                         /* break; */
 874
 875                 default:
 876                         SSLerr(SSL_F_DTLS1_ACCEPT,SSL_R_UNKNOWN_STATE);
 877                         ret= -1;
 878                         goto end;
 879                         /* break; */
 880                         }
 881
 882                 if (!s->s3->tmp.reuse_message && !skip)
 883                         {
 884                         if (s->debug)
 885                                 {
 886                                 if ((ret=BIO_flush(s->wbio)) <= 0)
 887                                         goto end;
 888                                 }
 889
 890
 891                         if ((cb != NULL) && (s->state != state))
 892                                 {
 893                                 new_state=s->state;
 894                                 s->state=state;
 895                                 cb(s,SSL_CB_ACCEPT_LOOP,1);
 896                                 s->state=new_state;
 897                                 }
 898                         }
 899                 skip=0;
 900                 }
 901 end:
 902         /* BIO_flush(s->wbio); */
 903
 904         s->in_handshake--;
 905 #ifndef OPENSSL_NO_SCTP
 906                 /* Notify SCTP BIO socket to leave handshake
 907                  * mode and prevent stream identifier other
 908                  * than 0. Will be ignored if no SCTP is used.
 909                  */
 910                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE, s->in_handshake, NULL);
 911 #endif
 912
 913         if (cb != NULL)
 914                 cb(s,SSL_CB_ACCEPT_EXIT,ret);
 915         return(ret);
 916         }
 917
 918 int dtls1_send_hello_verify_request(SSL *s)
 919         {
 920         unsigned int msg_len;
 921         unsigned char *msg, *buf, *p;
 922
 923         if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A)
 924                 {
 925                 buf = (unsigned char *)s->init_buf->data;
 926
 927                 msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
 928                 /* Always use DTLS 1.0 version: see RFC 6347 */
 929                 *(p++) = DTLS1_VERSION >> 8;
 930                 *(p++) = DTLS1_VERSION & 0xFF;
 931
 932                 if (s->ctx->app_gen_cookie_cb == NULL ||
 933                      s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
 934                          &(s->d1->cookie_len)) == 0)
 935                         {
 936                         SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,ERR_R_INTERNAL_ERROR);
 937                         return 0;
 938                         }
 939
 940                 *(p++) = (unsigned char) s->d1->cookie_len;
 941                 memcpy(p, s->d1->cookie, s->d1->cookie_len);
 942                 p += s->d1->cookie_len;
 943                 msg_len = p - msg;
 944
 945                 dtls1_set_message_header(s, buf,
 946                         DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0, msg_len);
 947
 948                 s->state=DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
 949                 /* number of bytes to write */
 950                 s->init_num=p-buf;
 951                 s->init_off=0;
 952                 }
 953
 954         /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
 955         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 956         }