ssl/t1_lib.c

   1 /* ssl/t1_lib.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <stdio.h>
  60 #include <openssl/objects.h>
  61 #include <openssl/evp.h>
  62 #include <openssl/hmac.h>
  63 #include <openssl/ocsp.h>
  64 #include "ssl_locl.h"
  65
  66 const char tls1_version_str[]="TLSv1" OPENSSL_VERSION_PTEXT;
  67
  68 #ifndef OPENSSL_NO_TLSEXT
  69 static int tls_decrypt_ticket(SSL *s, const unsigned char *tick, int ticklen,
  70                                 const unsigned char *sess_id, int sesslen,
  71                                 SSL_SESSION **psess);
  72 #endif
  73
  74 SSL3_ENC_METHOD TLSv1_enc_data={
  75         tls1_enc,
  76         tls1_mac,
  77         tls1_setup_key_block,
  78         tls1_generate_master_secret,
  79         tls1_change_cipher_state,
  80         tls1_final_finish_mac,
  81         TLS1_FINISH_MAC_LENGTH,
  82         tls1_cert_verify_mac,
  83         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
  84         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
  85         tls1_alert_code,
  86         };
  87
  88 long tls1_default_timeout(void)
  89         {
  90         /* 2 hours, the 24 hours mentioned in the TLSv1 spec
  91          * is way too long for http, the cache would over fill */
  92         return(60*60*2);
  93         }
  94
  95 IMPLEMENT_tls1_meth_func(tlsv1_base_method,
  96                         ssl_undefined_function,
  97                         ssl_undefined_function,
  98                         ssl_bad_method)
  99
 100 int tls1_new(SSL *s)
 101         {
 102         if (!ssl3_new(s)) return(0);
 103         s->method->ssl_clear(s);
 104         return(1);
 105         }
 106
 107 void tls1_free(SSL *s)
 108         {
 109         ssl3_free(s);
 110         }
 111
 112 void tls1_clear(SSL *s)
 113         {
 114         ssl3_clear(s);
 115         s->version=TLS1_VERSION;
 116         }
 117
 118 #if 0
 119 long tls1_ctrl(SSL *s, int cmd, long larg, char *parg)
 120         {
 121         return(0);
 122         }
 123
 124 long tls1_callback_ctrl(SSL *s, int cmd, void *(*fp)())
 125         {
 126         return(0);
 127         }
 128 #endif
 129
 130 #ifndef OPENSSL_NO_TLSEXT
 131 unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
 132         {
 133         int extdatalen=0;
 134         unsigned char *ret = p;
 135
 136         /* don't add extensions for SSLv3 unless doing secure renegotiation */
 137         if (s->client_version == SSL3_VERSION
 138                                         && !s->s3->send_connection_binding)
 139                 return p;
 140
 141         ret+=2;
 142
 143         if (ret>=limit) return NULL; /* this really never occurs, but ... */
 144
 145         if (s->tlsext_hostname != NULL)
 146                 {
 147                 /* Add TLS extension servername to the Client Hello message */
 148                 unsigned long size_str;
 149                 long lenmax;
 150
 151                 /* check for enough space.
 152                    4 for the servername type and entension length
 153                    2 for servernamelist length
 154                    1 for the hostname type
 155                    2 for hostname length
 156                    + hostname length
 157                 */
 158
 159                 if ((lenmax = limit - ret - 9) < 0
 160                 || (size_str = strlen(s->tlsext_hostname)) > (unsigned long)lenmax)
 161                         return NULL;
 162
 163                 /* extension type and length */
 164                 s2n(TLSEXT_TYPE_server_name,ret);
 165                 s2n(size_str+5,ret);
 166
 167                 /* length of servername list */
 168                 s2n(size_str+3,ret);
 169
 170                 /* hostname type, length and hostname */
 171                 *(ret++) = (unsigned char) TLSEXT_NAMETYPE_host_name;
 172                 s2n(size_str,ret);
 173                 memcpy(ret, s->tlsext_hostname, size_str);
 174                 ret+=size_str;
 175
 176                 }
 177
 178         /* Add the renegotiation option: TODOEKR switch */
 179         {
 180           int el;
 181
 182           if(!ssl_add_clienthello_renegotiate_ext(s, 0, &el, 0))
 183               {
 184               SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 185               return NULL;
 186               }
 187
 188           if((limit - p - 4 - el) < 0) return NULL;
 189
 190           s2n(TLSEXT_TYPE_renegotiate,ret);
 191           s2n(el,ret);
 192
 193           if(!ssl_add_clienthello_renegotiate_ext(s, ret, &el, el))
 194               {
 195               SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 196               return NULL;
 197               }
 198
 199           ret += el;
 200         }
 201
 202
 203         if (!(SSL_get_options(s) & SSL_OP_NO_TICKET))
 204                 {
 205                 int ticklen;
 206                 if (!s->new_session && s->session && s->session->tlsext_tick)
 207                         ticklen = s->session->tlsext_ticklen;
 208                 else
 209                         ticklen = 0;
 210                 /* Check for enough room 2 for extension type, 2 for len
 211                  * rest for ticket
 212                  */
 213                 if (limit - ret - 4 - ticklen < 0)
 214                         return NULL;
 215                 s2n(TLSEXT_TYPE_session_ticket,ret);
 216                 s2n(ticklen,ret);
 217                 if (ticklen)
 218                         {
 219                         memcpy(ret, s->session->tlsext_tick, ticklen);
 220                         ret += ticklen;
 221                         }
 222                 }
 223
 224         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp &&
 225             s->version != DTLS1_VERSION)
 226                 {
 227                 int i;
 228                 long extlen, idlen, itmp;
 229                 OCSP_RESPID *id;
 230
 231                 idlen = 0;
 232                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
 233                         {
 234                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
 235                         itmp = i2d_OCSP_RESPID(id, NULL);
 236                         if (itmp <= 0)
 237                                 return NULL;
 238                         idlen += itmp + 2;
 239                         }
 240
 241                 if (s->tlsext_ocsp_exts)
 242                         {
 243                         extlen = i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, NULL);
 244                         if (extlen < 0)
 245                                 return NULL;
 246                         }
 247                 else
 248                         extlen = 0;
 249
 250                 if ((long)(limit - ret - 7 - extlen - idlen) < 0) return NULL;
 251                 s2n(TLSEXT_TYPE_status_request, ret);
 252                 if (extlen + idlen > 0xFFF0)
 253                         return NULL;
 254                 s2n(extlen + idlen + 5, ret);
 255                 *(ret++) = TLSEXT_STATUSTYPE_ocsp;
 256                 s2n(idlen, ret);
 257                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
 258                         {
 259                         /* save position of id len */
 260                         unsigned char *q = ret;
 261                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
 262                         /* skip over id len */
 263                         ret += 2;
 264                         itmp = i2d_OCSP_RESPID(id, &ret);
 265                         /* write id len */
 266                         s2n(itmp, q);
 267                         }
 268                 s2n(extlen, ret);
 269                 if (extlen > 0)
 270                         i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
 271                 }
 272
 273         if ((extdatalen = ret-p-2)== 0)
 274                 return p;
 275
 276         s2n(extdatalen,p);
 277         return ret;
 278         }
 279
 280 unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
 281         {
 282         int extdatalen=0;
 283         unsigned char *ret = p;
 284
 285         /* don't add extensions for SSLv3, unless doing secure renegotiation */
 286         if (s->version == SSL3_VERSION && !s->s3->send_connection_binding)
 287                 return p;
 288
 289         ret+=2;
 290         if (ret>=limit) return NULL; /* this really never occurs, but ... */
 291
 292         if (!s->hit && s->servername_done == 1 && s->session->tlsext_hostname != NULL)
 293                 {
 294                 if (limit - ret - 4 < 0) return NULL;
 295
 296                 s2n(TLSEXT_TYPE_server_name,ret);
 297                 s2n(0,ret);
 298                 }
 299
 300         if(s->s3->send_connection_binding)
 301         {
 302           int el;
 303
 304           if(!ssl_add_serverhello_renegotiate_ext(s, 0, &el, 0))
 305               {
 306               SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 307               return NULL;
 308               }
 309
 310           if((limit - p - 4 - el) < 0) return NULL;
 311
 312           s2n(TLSEXT_TYPE_renegotiate,ret);
 313           s2n(el,ret);
 314
 315           if(!ssl_add_serverhello_renegotiate_ext(s, ret, &el, el))
 316               {
 317               SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 318               return NULL;
 319               }
 320
 321           ret += el;
 322         }
 323
 324         if (s->tlsext_ticket_expected
 325                 && !(SSL_get_options(s) & SSL_OP_NO_TICKET))
 326                 {
 327                 if (limit - ret - 4 < 0) return NULL;
 328                 s2n(TLSEXT_TYPE_session_ticket,ret);
 329                 s2n(0,ret);
 330                 }
 331
 332         if (s->tlsext_status_expected)
 333                 {
 334                 if ((long)(limit - ret - 4) < 0) return NULL;
 335                 s2n(TLSEXT_TYPE_status_request,ret);
 336                 s2n(0,ret);
 337                 }
 338
 339         if ((extdatalen = ret-p-2)== 0)
 340                 return p;
 341
 342         s2n(extdatalen,p);
 343         return ret;
 344         }
 345
 346 int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
 347         {
 348         unsigned short type;
 349         unsigned short size;
 350         unsigned short len;
 351         unsigned char *data = *p;
 352         int renegotiate_seen = 0;
 353
 354         s->servername_done = 0;
 355         s->tlsext_status_type = -1;
 356
 357         if (data >= (d+n-2))
 358                 goto ri_check;
 359
 360         n2s(data,len);
 361
 362         if (data > (d+n-len))
 363                 goto ri_check;
 364
 365         while (data <= (d+n-4))
 366                 {
 367                 n2s(data,type);
 368                 n2s(data,size);
 369
 370                 if (data+size > (d+n))
 371                         goto ri_check;
 372
 373                 if (s->tlsext_debug_cb)
 374                         s->tlsext_debug_cb(s, 0, type, data, size,
 375                                                 s->tlsext_debug_arg);
 376 /* The servername extension is treated as follows:
 377
 378    - Only the hostname type is supported with a maximum length of 255.
 379    - The servername is rejected if too long or if it contains zeros,
 380      in which case an fatal alert is generated.
 381    - The servername field is maintained together with the session cache.
 382    - When a session is resumed, the servername call back invoked in order
 383      to allow the application to position itself to the right context.
 384    - The servername is acknowledged if it is new for a session or when
 385      it is identical to a previously used for the same session.
 386      Applications can control the behaviour.  They can at any time
 387      set a 'desirable' servername for a new SSL object. This can be the
 388      case for example with HTTPS when a Host: header field is received and
 389      a renegotiation is requested. In this case, a possible servername
 390      presented in the new client hello is only acknowledged if it matches
 391      the value of the Host: field.
 392    - Applications must  use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
 393      if they provide for changing an explicit servername context for the session,
 394      i.e. when the session has been established with a servername extension.
 395    - On session reconnect, the servername extension may be absent.
 396
 397 */
 398
 399                 if (type == TLSEXT_TYPE_server_name)
 400                         {
 401                         unsigned char *sdata;
 402                         int servname_type;
 403                         int dsize;
 404
 405                         if (size < 2)
 406                                 {
 407                                 *al = SSL_AD_DECODE_ERROR;
 408                                 return 0;
 409                                 }
 410                         n2s(data,dsize);
 411                         size -= 2;
 412                         if (dsize > size  )
 413                                 {
 414                                 *al = SSL_AD_DECODE_ERROR;
 415                                 return 0;
 416                                 }
 417
 418                         sdata = data;
 419                         while (dsize > 3)
 420                                 {
 421                                 servname_type = *(sdata++);
 422                                 n2s(sdata,len);
 423                                 dsize -= 3;
 424
 425                                 if (len > dsize)
 426                                         {
 427                                         *al = SSL_AD_DECODE_ERROR;
 428                                         return 0;
 429                                         }
 430                                 if (s->servername_done == 0)
 431                                 switch (servname_type)
 432                                         {
 433                                 case TLSEXT_NAMETYPE_host_name:
 434                                         if (s->session->tlsext_hostname == NULL)
 435                                                 {
 436                                                 if (len > TLSEXT_MAXLEN_host_name ||
 437                                                         ((s->session->tlsext_hostname = OPENSSL_malloc(len+1)) == NULL))
 438                                                         {
 439                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
 440                                                         return 0;
 441                                                         }
 442                                                 memcpy(s->session->tlsext_hostname, sdata, len);
 443                                                 s->session->tlsext_hostname[len]='\0';
 444                                                 if (strlen(s->session->tlsext_hostname) != len) {
 445                                                         OPENSSL_free(s->session->tlsext_hostname);
 446                                                         s->session->tlsext_hostname = NULL;
 447                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
 448                                                         return 0;
 449                                                 }
 450                                                 s->servername_done = 1;
 451
 452                                                 }
 453                                         else
 454                                                 s->servername_done = strlen(s->session->tlsext_hostname) == len
 455                                                         && strncmp(s->session->tlsext_hostname, (char *)sdata, len) == 0;
 456
 457                                         break;
 458
 459                                 default:
 460                                         break;
 461                                         }
 462
 463                                 dsize -= len;
 464                                 }
 465                         if (dsize != 0)
 466                                 {
 467                                 *al = SSL_AD_DECODE_ERROR;
 468                                 return 0;
 469                                 }
 470
 471                         }
 472                 else if (type == TLSEXT_TYPE_renegotiate)
 473                         {
 474                         if(!ssl_parse_clienthello_renegotiate_ext(s, data, size, al))
 475                                 return 0;
 476                         renegotiate_seen = 1;
 477                         }
 478                 else if (type == TLSEXT_TYPE_status_request &&
 479                          s->version != DTLS1_VERSION && s->ctx->tlsext_status_cb)
 480                         {
 481
 482                         if (size < 5)
 483                                 {
 484                                 *al = SSL_AD_DECODE_ERROR;
 485                                 return 0;
 486                                 }
 487
 488                         s->tlsext_status_type = *data++;
 489                         size--;
 490                         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
 491                                 {
 492                                 const unsigned char *sdata;
 493                                 int dsize;
 494                                 /* Read in responder_id_list */
 495                                 n2s(data,dsize);
 496                                 size -= 2;
 497                                 if (dsize > size  )
 498                                         {
 499                                         *al = SSL_AD_DECODE_ERROR;
 500                                         return 0;
 501                                         }
 502                                 while (dsize > 0)
 503                                         {
 504                                         OCSP_RESPID *id;
 505                                         int idsize;
 506                                         if (dsize < 4)
 507                                                 {
 508                                                 *al = SSL_AD_DECODE_ERROR;
 509                                                 return 0;
 510                                                 }
 511                                         n2s(data, idsize);
 512                                         dsize -= 2 + idsize;
 513                                         if (dsize < 0)
 514                                                 {
 515                                                 *al = SSL_AD_DECODE_ERROR;
 516                                                 return 0;
 517                                                 }
 518                                         sdata = data;
 519                                         data += idsize;
 520                                         id = d2i_OCSP_RESPID(NULL,
 521                                                                 &sdata, idsize);
 522                                         if (!id)
 523                                                 {
 524                                                 *al = SSL_AD_DECODE_ERROR;
 525                                                 return 0;
 526                                                 }
 527                                         if (data != sdata)
 528                                                 {
 529                                                 OCSP_RESPID_free(id);
 530                                                 *al = SSL_AD_DECODE_ERROR;
 531                                                 return 0;
 532                                                 }
 533                                         if (!s->tlsext_ocsp_ids
 534                                                 && !(s->tlsext_ocsp_ids =
 535                                                 sk_OCSP_RESPID_new_null()))
 536                                                 {
 537                                                 OCSP_RESPID_free(id);
 538                                                 *al = SSL_AD_INTERNAL_ERROR;
 539                                                 return 0;
 540                                                 }
 541                                         if (!sk_OCSP_RESPID_push(
 542                                                         s->tlsext_ocsp_ids, id))
 543                                                 {
 544                                                 OCSP_RESPID_free(id);
 545                                                 *al = SSL_AD_INTERNAL_ERROR;
 546                                                 return 0;
 547                                                 }
 548                                         }
 549
 550                                 /* Read in request_extensions */
 551                                 n2s(data,dsize);
 552                                 size -= 2;
 553                                 if (dsize > size)
 554                                         {
 555                                         *al = SSL_AD_DECODE_ERROR;
 556                                         return 0;
 557                                         }
 558                                 sdata = data;
 559                                 if (dsize > 0)
 560                                         {
 561                                         s->tlsext_ocsp_exts =
 562                                                 d2i_X509_EXTENSIONS(NULL,
 563                                                         &sdata, dsize);
 564                                         if (!s->tlsext_ocsp_exts
 565                                                 || (data + dsize != sdata))
 566                                                 {
 567                                                 *al = SSL_AD_DECODE_ERROR;
 568                                                 return 0;
 569                                                 }
 570                                         }
 571                                 }
 572                                 /* We don't know what to do with any other type
 573                                 * so ignore it.
 574                                 */
 575                                 else
 576                                         s->tlsext_status_type = -1;
 577                         }
 578
 579                 /* session ticket processed earlier */
 580
 581                 data+=size;
 582                 }
 583         *p = data;
 584
 585         ri_check:
 586
 587         /* Need RI if renegotiating */
 588
 589         if (!renegotiate_seen && s->new_session &&
 590                 !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
 591                 {
 592                 *al = SSL_AD_HANDSHAKE_FAILURE;
 593                 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT,
 594                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
 595                 return 0;
 596                 }
 597
 598         return 1;
 599         }
 600
 601 int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
 602         {
 603         unsigned short type;
 604         unsigned short size;
 605         unsigned short len;
 606         unsigned char *data = *p;
 607         int tlsext_servername = 0;
 608         int renegotiate_seen = 0;
 609
 610         if (data >= (d+n-2))
 611                 goto ri_check;
 612
 613         n2s(data,len);
 614
 615         while(data <= (d+n-4))
 616                 {
 617                 n2s(data,type);
 618                 n2s(data,size);
 619
 620                 if (data+size > (d+n))
 621                         goto ri_check;
 622
 623                 if (s->tlsext_debug_cb)
 624                         s->tlsext_debug_cb(s, 1, type, data, size,
 625                                                 s->tlsext_debug_arg);
 626
 627                 if (type == TLSEXT_TYPE_server_name)
 628                         {
 629                         if (s->tlsext_hostname == NULL || size > 0)
 630                                 {
 631                                 *al = TLS1_AD_UNRECOGNIZED_NAME;
 632                                 return 0;
 633                                 }
 634                         tlsext_servername = 1;
 635                         }
 636                 else if (type == TLSEXT_TYPE_session_ticket)
 637                         {
 638                         if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
 639                                 || (size > 0))
 640                                 {
 641                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
 642                                 return 0;
 643                                 }
 644                         s->tlsext_ticket_expected = 1;
 645                         }
 646                 else if (type == TLSEXT_TYPE_status_request &&
 647                          s->version != DTLS1_VERSION)
 648                         {
 649                         /* MUST be empty and only sent if we've requested
 650                          * a status request message.
 651                          */
 652                         if ((s->tlsext_status_type == -1) || (size > 0))
 653                                 {
 654                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
 655                                 return 0;
 656                                 }
 657                         /* Set flag to expect CertificateStatus message */
 658                         s->tlsext_status_expected = 1;
 659                         }
 660                 else if (type == TLSEXT_TYPE_renegotiate)
 661                         {
 662                         if(!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
 663                                 return 0;
 664                         renegotiate_seen = 1;
 665                         }
 666                 data+=size;
 667                 }
 668
 669         if (data != d+n)
 670                 {
 671                 *al = SSL_AD_DECODE_ERROR;
 672                 return 0;
 673                 }
 674
 675         if (!s->hit && tlsext_servername == 1)
 676                 {
 677                 if (s->tlsext_hostname)
 678                         {
 679                         if (s->session->tlsext_hostname == NULL)
 680                                 {
 681                                 s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);
 682                                 if (!s->session->tlsext_hostname)
 683                                         {
 684                                         *al = SSL_AD_UNRECOGNIZED_NAME;
 685                                         return 0;
 686                                         }
 687                                 }
 688                         else
 689                                 {
 690                                 *al = SSL_AD_DECODE_ERROR;
 691                                 return 0;
 692                                 }
 693                         }
 694                 }
 695
 696         *p = data;
 697
 698         ri_check:
 699
 700         /* Determine if we need to see RI. Strictly speaking if we want to
 701          * avoid an attack we should *always* see RI even on initial server
 702          * hello because the client doesn't see any renegotiation during an
 703          * attack. However this would mean we could not connect to any server
 704          * which doesn't support RI so for the immediate future tolerate RI
 705          * absence on initial connect only.
 706          */
 707         if (!renegotiate_seen &&
 708                 (s->new_session || !(s->options & SSL_OP_LEGACY_SERVER_CONNECT))
 709                 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
 710                 {
 711                 *al = SSL_AD_HANDSHAKE_FAILURE;
 712                 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT,
 713                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
 714                 return 0;
 715                 }
 716
 717         return 1;
 718         }
 719
 720 int ssl_check_clienthello_tlsext(SSL *s)
 721         {
 722         int ret=SSL_TLSEXT_ERR_NOACK;
 723         int al = SSL_AD_UNRECOGNIZED_NAME;
 724
 725         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
 726                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
 727         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
 728                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
 729
 730         /* If status request then ask callback what to do.
 731          * Note: this must be called after servername callbacks in case
 732          * the certificate has changed.
 733          */
 734         if ((s->tlsext_status_type != -1) && s->ctx->tlsext_status_cb)
 735                 {
 736                 int r;
 737                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
 738                 switch (r)
 739                         {
 740                         /* We don't want to send a status request response */
 741                         case SSL_TLSEXT_ERR_NOACK:
 742                                 s->tlsext_status_expected = 0;
 743                                 break;
 744                         /* status request response should be sent */
 745                         case SSL_TLSEXT_ERR_OK:
 746                                 if (s->tlsext_ocsp_resp)
 747                                         s->tlsext_status_expected = 1;
 748                                 else
 749                                         s->tlsext_status_expected = 0;
 750                                 break;
 751                         /* something bad happened */
 752                         case SSL_TLSEXT_ERR_ALERT_FATAL:
 753                                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
 754                                 al = SSL_AD_INTERNAL_ERROR;
 755                                 goto err;
 756                         }
 757                 }
 758         else
 759                 s->tlsext_status_expected = 0;
 760         err:
 761         switch (ret)
 762                 {
 763                 case SSL_TLSEXT_ERR_ALERT_FATAL:
 764                         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 765                         return -1;
 766
 767                 case SSL_TLSEXT_ERR_ALERT_WARNING:
 768                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
 769                         return 1;
 770
 771                 case SSL_TLSEXT_ERR_NOACK:
 772                         s->servername_done=0;
 773                         default:
 774                 return 1;
 775                 }
 776         }
 777
 778 int ssl_check_serverhello_tlsext(SSL *s)
 779         {
 780         int ret=SSL_TLSEXT_ERR_NOACK;
 781         int al = SSL_AD_UNRECOGNIZED_NAME;
 782
 783         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
 784                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
 785         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
 786                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
 787
 788         /* If we've requested certificate status and we wont get one
 789          * tell the callback
 790          */
 791         if ((s->tlsext_status_type != -1) && !(s->tlsext_status_expected)
 792                         && s->ctx->tlsext_status_cb)
 793                 {
 794                 int r;
 795                 /* Set resp to NULL, resplen to -1 so callback knows
 796                  * there is no response.
 797                  */
 798                 if (s->tlsext_ocsp_resp)
 799                         {
 800                         OPENSSL_free(s->tlsext_ocsp_resp);
 801                         s->tlsext_ocsp_resp = NULL;
 802                         }
 803                 s->tlsext_ocsp_resplen = -1;
 804                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
 805                 if (r == 0)
 806                         {
 807                         al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
 808                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
 809                         }
 810                 if (r < 0)
 811                         {
 812                         al = SSL_AD_INTERNAL_ERROR;
 813                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
 814                         }
 815                 }
 816
 817         switch (ret)
 818                 {
 819                 case SSL_TLSEXT_ERR_ALERT_FATAL:
 820                         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 821                         return -1;
 822
 823                 case SSL_TLSEXT_ERR_ALERT_WARNING:
 824                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
 825                         return 1;
 826
 827                 case SSL_TLSEXT_ERR_NOACK:
 828                         s->servername_done=0;
 829                         default:
 830                 return 1;
 831                 }
 832         }
 833
 834 /* Since the server cache lookup is done early on in the processing of client
 835  * hello and other operations depend on the result we need to handle any TLS
 836  * session ticket extension at the same time.
 837  */
 838
 839 int tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
 840                                 const unsigned char *limit, SSL_SESSION **ret)
 841         {
 842         /* Point after session ID in client hello */
 843         const unsigned char *p = session_id + len;
 844         unsigned short i;
 845
 846         /* If tickets disabled behave as if no ticket present
 847          * to permit stateful resumption.
 848          */
 849         if (SSL_get_options(s) & SSL_OP_NO_TICKET)
 850                 return 1;
 851
 852         if ((s->version <= SSL3_VERSION) || !limit)
 853                 return 1;
 854         if (p >= limit)
 855                 return -1;
 856         /* Skip past DTLS cookie */
 857         if (s->version == DTLS1_VERSION || s->version == DTLS1_BAD_VER)
 858                 {
 859                 i = *(p++);
 860                 p+= i;
 861                 if (p >= limit)
 862                         return -1;
 863                 }
 864         /* Skip past cipher list */
 865         n2s(p, i);
 866         p+= i;
 867         if (p >= limit)
 868                 return -1;
 869         /* Skip past compression algorithm list */
 870         i = *(p++);
 871         p += i;
 872         if (p > limit)
 873                 return -1;
 874         /* Now at start of extensions */
 875         if ((p + 2) >= limit)
 876                 return 1;
 877         n2s(p, i);
 878         while ((p + 4) <= limit)
 879                 {
 880                 unsigned short type, size;
 881                 n2s(p, type);
 882                 n2s(p, size);
 883                 if (p + size > limit)
 884                         return 1;
 885                 if (type == TLSEXT_TYPE_session_ticket)
 886                         {
 887                         /* If zero length note client will accept a ticket
 888                          * and indicate cache miss to trigger full handshake
 889                          */
 890                         if (size == 0)
 891                                 {
 892                                 s->tlsext_ticket_expected = 1;
 893                                 return 0;       /* Cache miss */
 894                                 }
 895                         return tls_decrypt_ticket(s, p, size, session_id, len,
 896                                                                         ret);
 897                         }
 898                 p += size;
 899                 }
 900         return 1;
 901         }
 902
 903 static int tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen,
 904                                 const unsigned char *sess_id, int sesslen,
 905                                 SSL_SESSION **psess)
 906         {
 907         SSL_SESSION *sess;
 908         unsigned char *sdec;
 909         const unsigned char *p;
 910         int slen, mlen, renew_ticket = 0;
 911         unsigned char tick_hmac[EVP_MAX_MD_SIZE];
 912         HMAC_CTX hctx;
 913         EVP_CIPHER_CTX ctx;
 914         SSL_CTX *tctx = s->initial_ctx;
 915         /* Need at least keyname + iv + some encrypted data */
 916         if (eticklen < 48)
 917                 goto tickerr;
 918         /* Initialize session ticket encryption and HMAC contexts */
 919         HMAC_CTX_init(&hctx);
 920         EVP_CIPHER_CTX_init(&ctx);
 921         if (tctx->tlsext_ticket_key_cb)
 922                 {
 923                 unsigned char *nctick = (unsigned char *)etick;
 924                 int rv = tctx->tlsext_ticket_key_cb(s, nctick, nctick + 16,
 925                                                         &ctx, &hctx, 0);
 926                 if (rv < 0)
 927                         return -1;
 928                 if (rv == 0)
 929                         goto tickerr;
 930                 if (rv == 2)
 931                         renew_ticket = 1;
 932                 }
 933         else
 934                 {
 935                 /* Check key name matches */
 936                 if (memcmp(etick, tctx->tlsext_tick_key_name, 16))
 937                         goto tickerr;
 938                 HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,
 939                                         tlsext_tick_md(), NULL);
 940                 EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
 941                                 tctx->tlsext_tick_aes_key, etick + 16);
 942                 }
 943         /* Attempt to process session ticket, first conduct sanity and
 944          * integrity checks on ticket.
 945          */
 946         mlen = HMAC_size(&hctx);
 947         eticklen -= mlen;
 948         /* Check HMAC of encrypted ticket */
 949         HMAC_Update(&hctx, etick, eticklen);
 950         HMAC_Final(&hctx, tick_hmac, NULL);
 951         HMAC_CTX_cleanup(&hctx);
 952         if (memcmp(tick_hmac, etick + eticklen, mlen))
 953                 goto tickerr;
 954         /* Attempt to decrypt session data */
 955         /* Move p after IV to start of encrypted ticket, update length */
 956         p = etick + 16 + EVP_CIPHER_CTX_iv_length(&ctx);
 957         eticklen -= 16 + EVP_CIPHER_CTX_iv_length(&ctx);
 958         sdec = OPENSSL_malloc(eticklen);
 959         if (!sdec)
 960                 {
 961                 EVP_CIPHER_CTX_cleanup(&ctx);
 962                 return -1;
 963                 }
 964         EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen);
 965         if (EVP_DecryptFinal(&ctx, sdec + slen, &mlen) <= 0)
 966                 goto tickerr;
 967         slen += mlen;
 968         EVP_CIPHER_CTX_cleanup(&ctx);
 969         p = sdec;
 970
 971         sess = d2i_SSL_SESSION(NULL, &p, slen);
 972         OPENSSL_free(sdec);
 973         if (sess)
 974                 {
 975                 /* The session ID if non-empty is used by some clients to
 976                  * detect that the ticket has been accepted. So we copy it to
 977                  * the session structure. If it is empty set length to zero
 978                  * as required by standard.
 979                  */
 980                 if (sesslen)
 981                         memcpy(sess->session_id, sess_id, sesslen);
 982                 sess->session_id_length = sesslen;
 983                 *psess = sess;
 984                 s->tlsext_ticket_expected = renew_ticket;
 985                 return 1;
 986                 }
 987         /* If session decrypt failure indicate a cache miss and set state to
 988          * send a new ticket
 989          */
 990         tickerr:
 991         s->tlsext_ticket_expected = 1;
 992         return 0;
 993         }
 994
 995 #endif