crypto/openssl/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         ret+=2;
 137
 138         if (ret>=limit) return NULL; /* this really never occurs, but ... */
 139
 140         if (s->tlsext_hostname != NULL)
 141                 {
 142                 /* Add TLS extension servername to the Client Hello message */
 143                 unsigned long size_str;
 144                 long lenmax;
 145
 146                 /* check for enough space.
 147                    4 for the servername type and entension length
 148                    2 for servernamelist length
 149                    1 for the hostname type
 150                    2 for hostname length
 151                    + hostname length
 152                 */
 153
 154                 if ((lenmax = limit - ret - 9) < 0
 155                 || (size_str = strlen(s->tlsext_hostname)) > (unsigned long)lenmax)
 156                         return NULL;
 157
 158                 /* extension type and length */
 159                 s2n(TLSEXT_TYPE_server_name,ret);
 160                 s2n(size_str+5,ret);
 161
 162                 /* length of servername list */
 163                 s2n(size_str+3,ret);
 164
 165                 /* hostname type, length and hostname */
 166                 *(ret++) = (unsigned char) TLSEXT_NAMETYPE_host_name;
 167                 s2n(size_str,ret);
 168                 memcpy(ret, s->tlsext_hostname, size_str);
 169                 ret+=size_str;
 170
 171                 }
 172
 173         if (!(SSL_get_options(s) & SSL_OP_NO_TICKET))
 174                 {
 175                 int ticklen;
 176                 if (s->session && s->session->tlsext_tick)
 177                         ticklen = s->session->tlsext_ticklen;
 178                 else
 179                         ticklen = 0;
 180                 /* Check for enough room 2 for extension type, 2 for len
 181                  * rest for ticket
 182                  */
 183                 if (limit - ret - 4 - ticklen < 0)
 184                         return NULL;
 185                 s2n(TLSEXT_TYPE_session_ticket,ret);
 186                 s2n(ticklen,ret);
 187                 if (ticklen)
 188                         {
 189                         memcpy(ret, s->session->tlsext_tick, ticklen);
 190                         ret += ticklen;
 191                         }
 192                 }
 193
 194         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
 195                 {
 196                 int i;
 197                 long extlen, idlen, itmp;
 198                 OCSP_RESPID *id;
 199
 200                 idlen = 0;
 201                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
 202                         {
 203                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
 204                         itmp = i2d_OCSP_RESPID(id, NULL);
 205                         if (itmp <= 0)
 206                                 return NULL;
 207                         idlen += itmp + 2;
 208                         }
 209
 210                 if (s->tlsext_ocsp_exts)
 211                         {
 212                         extlen = i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, NULL);
 213                         if (extlen < 0)
 214                                 return NULL;
 215                         }
 216                 else
 217                         extlen = 0;
 218
 219                 if ((long)(limit - ret - 7 - extlen - idlen) < 0) return NULL;
 220                 s2n(TLSEXT_TYPE_status_request, ret);
 221                 if (extlen + idlen > 0xFFF0)
 222                         return NULL;
 223                 s2n(extlen + idlen + 5, ret);
 224                 *(ret++) = TLSEXT_STATUSTYPE_ocsp;
 225                 s2n(idlen, ret);
 226                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
 227                         {
 228                         /* save position of id len */
 229                         unsigned char *q = ret;
 230                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
 231                         /* skip over id len */
 232                         ret += 2;
 233                         itmp = i2d_OCSP_RESPID(id, &ret);
 234                         /* write id len */
 235                         s2n(itmp, q);
 236                         }
 237                 s2n(extlen, ret);
 238                 if (extlen > 0)
 239                         i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
 240                 }
 241
 242         if ((extdatalen = ret-p-2)== 0)
 243                 return p;
 244
 245         s2n(extdatalen,p);
 246         return ret;
 247         }
 248
 249 unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
 250         {
 251         int extdatalen=0;
 252         unsigned char *ret = p;
 253
 254         ret+=2;
 255         if (ret>=limit) return NULL; /* this really never occurs, but ... */
 256
 257         if (!s->hit && s->servername_done == 1 && s->session->tlsext_hostname != NULL)
 258                 {
 259                 if (limit - ret - 4 < 0) return NULL;
 260
 261                 s2n(TLSEXT_TYPE_server_name,ret);
 262                 s2n(0,ret);
 263                 }
 264
 265         if (s->tlsext_ticket_expected
 266                 && !(SSL_get_options(s) & SSL_OP_NO_TICKET))
 267                 {
 268                 if (limit - ret - 4 < 0) return NULL;
 269                 s2n(TLSEXT_TYPE_session_ticket,ret);
 270                 s2n(0,ret);
 271                 }
 272
 273         if (s->tlsext_status_expected)
 274                 {
 275                 if ((long)(limit - ret - 4) < 0) return NULL;
 276                 s2n(TLSEXT_TYPE_status_request,ret);
 277                 s2n(0,ret);
 278                 }
 279
 280         if ((extdatalen = ret-p-2)== 0)
 281                 return p;
 282
 283         s2n(extdatalen,p);
 284         return ret;
 285         }
 286
 287 int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
 288         {
 289         unsigned short type;
 290         unsigned short size;
 291         unsigned short len;
 292         unsigned char *data = *p;
 293         s->servername_done = 0;
 294         s->tlsext_status_type = -1;
 295
 296         if (data >= (d+n-2))
 297                 return 1;
 298         n2s(data,len);
 299
 300         if (data > (d+n-len))
 301                 return 1;
 302
 303         while (data <= (d+n-4))
 304                 {
 305                 n2s(data,type);
 306                 n2s(data,size);
 307
 308                 if (data+size > (d+n))
 309                         return 1;
 310
 311                 if (s->tlsext_debug_cb)
 312                         s->tlsext_debug_cb(s, 0, type, data, size,
 313                                                 s->tlsext_debug_arg);
 314 /* The servername extension is treated as follows:
 315
 316    - Only the hostname type is supported with a maximum length of 255.
 317    - The servername is rejected if too long or if it contains zeros,
 318      in which case an fatal alert is generated.
 319    - The servername field is maintained together with the session cache.
 320    - When a session is resumed, the servername call back invoked in order
 321      to allow the application to position itself to the right context.
 322    - The servername is acknowledged if it is new for a session or when
 323      it is identical to a previously used for the same session.
 324      Applications can control the behaviour.  They can at any time
 325      set a 'desirable' servername for a new SSL object. This can be the
 326      case for example with HTTPS when a Host: header field is received and
 327      a renegotiation is requested. In this case, a possible servername
 328      presented in the new client hello is only acknowledged if it matches
 329      the value of the Host: field.
 330    - Applications must  use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
 331      if they provide for changing an explicit servername context for the session,
 332      i.e. when the session has been established with a servername extension.
 333    - On session reconnect, the servername extension may be absent.
 334
 335 */
 336
 337                 if (type == TLSEXT_TYPE_server_name)
 338                         {
 339                         unsigned char *sdata;
 340                         int servname_type;
 341                         int dsize;
 342
 343                         if (size < 2)
 344                                 {
 345                                 *al = SSL_AD_DECODE_ERROR;
 346                                 return 0;
 347                                 }
 348                         n2s(data,dsize);
 349                         size -= 2;
 350                         if (dsize > size  )
 351                                 {
 352                                 *al = SSL_AD_DECODE_ERROR;
 353                                 return 0;
 354                                 }
 355
 356                         sdata = data;
 357                         while (dsize > 3)
 358                                 {
 359                                 servname_type = *(sdata++);
 360                                 n2s(sdata,len);
 361                                 dsize -= 3;
 362
 363                                 if (len > dsize)
 364                                         {
 365                                         *al = SSL_AD_DECODE_ERROR;
 366                                         return 0;
 367                                         }
 368                                 if (s->servername_done == 0)
 369                                 switch (servname_type)
 370                                         {
 371                                 case TLSEXT_NAMETYPE_host_name:
 372                                         if (s->session->tlsext_hostname == NULL)
 373                                                 {
 374                                                 if (len > TLSEXT_MAXLEN_host_name ||
 375                                                         ((s->session->tlsext_hostname = OPENSSL_malloc(len+1)) == NULL))
 376                                                         {
 377                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
 378                                                         return 0;
 379                                                         }
 380                                                 memcpy(s->session->tlsext_hostname, sdata, len);
 381                                                 s->session->tlsext_hostname[len]='\0';
 382                                                 if (strlen(s->session->tlsext_hostname) != len) {
 383                                                         OPENSSL_free(s->session->tlsext_hostname);
 384                                                         s->session->tlsext_hostname = NULL;
 385                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
 386                                                         return 0;
 387                                                 }
 388                                                 s->servername_done = 1;
 389
 390                                                 }
 391                                         else
 392                                                 s->servername_done = strlen(s->session->tlsext_hostname) == len
 393                                                         && strncmp(s->session->tlsext_hostname, (char *)sdata, len) == 0;
 394
 395                                         break;
 396
 397                                 default:
 398                                         break;
 399                                         }
 400
 401                                 dsize -= len;
 402                                 }
 403                         if (dsize != 0)
 404                                 {
 405                                 *al = SSL_AD_DECODE_ERROR;
 406                                 return 0;
 407                                 }
 408
 409                         }
 410                 else if (type == TLSEXT_TYPE_status_request
 411                                                 && s->ctx->tlsext_status_cb)
 412                         {
 413
 414                         if (size < 5)
 415                                 {
 416                                 *al = SSL_AD_DECODE_ERROR;
 417                                 return 0;
 418                                 }
 419
 420                         s->tlsext_status_type = *data++;
 421                         size--;
 422                         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
 423                                 {
 424                                 const unsigned char *sdata;
 425                                 int dsize;
 426                                 /* Read in responder_id_list */
 427                                 n2s(data,dsize);
 428                                 size -= 2;
 429                                 if (dsize > size  )
 430                                         {
 431                                         *al = SSL_AD_DECODE_ERROR;
 432                                         return 0;
 433                                         }
 434                                 while (dsize > 0)
 435                                         {
 436                                         OCSP_RESPID *id;
 437                                         int idsize;
 438                                         if (dsize < 4)
 439                                                 {
 440                                                 *al = SSL_AD_DECODE_ERROR;
 441                                                 return 0;
 442                                                 }
 443                                         n2s(data, idsize);
 444                                         dsize -= 2 + idsize;
 445                                         if (dsize < 0)
 446                                                 {
 447                                                 *al = SSL_AD_DECODE_ERROR;
 448                                                 return 0;
 449                                                 }
 450                                         sdata = data;
 451                                         data += idsize;
 452                                         id = d2i_OCSP_RESPID(NULL,
 453                                                                 &sdata, idsize);
 454                                         if (!id)
 455                                                 {
 456                                                 *al = SSL_AD_DECODE_ERROR;
 457                                                 return 0;
 458                                                 }
 459                                         if (data != sdata)
 460                                                 {
 461                                                 OCSP_RESPID_free(id);
 462                                                 *al = SSL_AD_DECODE_ERROR;
 463                                                 return 0;
 464                                                 }
 465                                         if (!s->tlsext_ocsp_ids
 466                                                 && !(s->tlsext_ocsp_ids =
 467                                                 sk_OCSP_RESPID_new_null()))
 468                                                 {
 469                                                 OCSP_RESPID_free(id);
 470                                                 *al = SSL_AD_INTERNAL_ERROR;
 471                                                 return 0;
 472                                                 }
 473                                         if (!sk_OCSP_RESPID_push(
 474                                                         s->tlsext_ocsp_ids, id))
 475                                                 {
 476                                                 OCSP_RESPID_free(id);
 477                                                 *al = SSL_AD_INTERNAL_ERROR;
 478                                                 return 0;
 479                                                 }
 480                                         }
 481
 482                                 /* Read in request_extensions */
 483                                 n2s(data,dsize);
 484                                 size -= 2;
 485                                 if (dsize > size)
 486                                         {
 487                                         *al = SSL_AD_DECODE_ERROR;
 488                                         return 0;
 489                                         }
 490                                 sdata = data;
 491                                 if (dsize > 0)
 492                                         {
 493                                         s->tlsext_ocsp_exts =
 494                                                 d2i_X509_EXTENSIONS(NULL,
 495                                                         &sdata, dsize);
 496                                         if (!s->tlsext_ocsp_exts
 497                                                 || (data + dsize != sdata))
 498                                                 {
 499                                                 *al = SSL_AD_DECODE_ERROR;
 500                                                 return 0;
 501                                                 }
 502                                         }
 503                                 }
 504                                 /* We don't know what to do with any other type
 505                                 * so ignore it.
 506                                 */
 507                                 else
 508                                         s->tlsext_status_type = -1;
 509                         }
 510                 /* session ticket processed earlier */
 511
 512                 data+=size;
 513                 }
 514
 515         *p = data;
 516         return 1;
 517         }
 518
 519 int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
 520         {
 521         unsigned short type;
 522         unsigned short size;
 523         unsigned short len;
 524         unsigned char *data = *p;
 525
 526         int tlsext_servername = 0;
 527
 528         if (data >= (d+n-2))
 529                 return 1;
 530
 531         n2s(data,len);
 532
 533         while(data <= (d+n-4))
 534                 {
 535                 n2s(data,type);
 536                 n2s(data,size);
 537
 538                 if (data+size > (d+n))
 539                         return 1;
 540
 541                 if (s->tlsext_debug_cb)
 542                         s->tlsext_debug_cb(s, 1, type, data, size,
 543                                                 s->tlsext_debug_arg);
 544
 545                 if (type == TLSEXT_TYPE_server_name)
 546                         {
 547                         if (s->tlsext_hostname == NULL || size > 0)
 548                                 {
 549                                 *al = TLS1_AD_UNRECOGNIZED_NAME;
 550                                 return 0;
 551                                 }
 552                         tlsext_servername = 1;
 553                         }
 554                 else if (type == TLSEXT_TYPE_session_ticket)
 555                         {
 556                         if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
 557                                 || (size > 0))
 558                                 {
 559                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
 560                                 return 0;
 561                                 }
 562                         s->tlsext_ticket_expected = 1;
 563                         }
 564                 else if (type == TLSEXT_TYPE_status_request)
 565                         {
 566                         /* MUST be empty and only sent if we've requested
 567                          * a status request message.
 568                          */
 569                         if ((s->tlsext_status_type == -1) || (size > 0))
 570                                 {
 571                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
 572                                 return 0;
 573                                 }
 574                         /* Set flag to expect CertificateStatus message */
 575                         s->tlsext_status_expected = 1;
 576                         }
 577
 578                 data+=size;
 579                 }
 580
 581         if (data != d+n)
 582                 {
 583                 *al = SSL_AD_DECODE_ERROR;
 584                 return 0;
 585                 }
 586
 587         if (!s->hit && tlsext_servername == 1)
 588                 {
 589                 if (s->tlsext_hostname)
 590                         {
 591                         if (s->session->tlsext_hostname == NULL)
 592                                 {
 593                                 s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);
 594                                 if (!s->session->tlsext_hostname)
 595                                         {
 596                                         *al = SSL_AD_UNRECOGNIZED_NAME;
 597                                         return 0;
 598                                         }
 599                                 }
 600                         else
 601                                 {
 602                                 *al = SSL_AD_DECODE_ERROR;
 603                                 return 0;
 604                                 }
 605                         }
 606                 }
 607
 608         *p = data;
 609         return 1;
 610         }
 611
 612 int ssl_check_clienthello_tlsext(SSL *s)
 613         {
 614         int ret=SSL_TLSEXT_ERR_NOACK;
 615         int al = SSL_AD_UNRECOGNIZED_NAME;
 616
 617         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
 618                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
 619         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
 620                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
 621
 622         /* If status request then ask callback what to do.
 623          * Note: this must be called after servername callbacks in case
 624          * the certificate has changed.
 625          */
 626         if ((s->tlsext_status_type != -1) && s->ctx->tlsext_status_cb)
 627                 {
 628                 int r;
 629                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
 630                 switch (r)
 631                         {
 632                         /* We don't want to send a status request response */
 633                         case SSL_TLSEXT_ERR_NOACK:
 634                                 s->tlsext_status_expected = 0;
 635                                 break;
 636                         /* status request response should be sent */
 637                         case SSL_TLSEXT_ERR_OK:
 638                                 if (s->tlsext_ocsp_resp)
 639                                         s->tlsext_status_expected = 1;
 640                                 else
 641                                         s->tlsext_status_expected = 0;
 642                                 break;
 643                         /* something bad happened */
 644                         case SSL_TLSEXT_ERR_ALERT_FATAL:
 645                                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
 646                                 al = SSL_AD_INTERNAL_ERROR;
 647                                 goto err;
 648                         }
 649                 }
 650         else
 651                 s->tlsext_status_expected = 0;
 652         err:
 653         switch (ret)
 654                 {
 655                 case SSL_TLSEXT_ERR_ALERT_FATAL:
 656                         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 657                         return -1;
 658
 659                 case SSL_TLSEXT_ERR_ALERT_WARNING:
 660                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
 661                         return 1;
 662
 663                 case SSL_TLSEXT_ERR_NOACK:
 664                         s->servername_done=0;
 665                         default:
 666                 return 1;
 667                 }
 668         }
 669
 670 int ssl_check_serverhello_tlsext(SSL *s)
 671         {
 672         int ret=SSL_TLSEXT_ERR_NOACK;
 673         int al = SSL_AD_UNRECOGNIZED_NAME;
 674
 675         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
 676                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
 677         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
 678                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
 679
 680         /* If we've requested certificate status and we wont get one
 681          * tell the callback
 682          */
 683         if ((s->tlsext_status_type != -1) && !(s->tlsext_status_expected)
 684                         && s->ctx->tlsext_status_cb)
 685                 {
 686                 int r;
 687                 /* Set resp to NULL, resplen to -1 so callback knows
 688                  * there is no response.
 689                  */
 690                 if (s->tlsext_ocsp_resp)
 691                         {
 692                         OPENSSL_free(s->tlsext_ocsp_resp);
 693                         s->tlsext_ocsp_resp = NULL;
 694                         }
 695                 s->tlsext_ocsp_resplen = -1;
 696                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
 697                 if (r == 0)
 698                         {
 699                         al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
 700                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
 701                         }
 702                 if (r < 0)
 703                         {
 704                         al = SSL_AD_INTERNAL_ERROR;
 705                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
 706                         }
 707                 }
 708
 709         switch (ret)
 710                 {
 711                 case SSL_TLSEXT_ERR_ALERT_FATAL:
 712                         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 713                         return -1;
 714
 715                 case SSL_TLSEXT_ERR_ALERT_WARNING:
 716                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
 717                         return 1;
 718
 719                 case SSL_TLSEXT_ERR_NOACK:
 720                         s->servername_done=0;
 721                         default:
 722                 return 1;
 723                 }
 724         }
 725
 726 /* Since the server cache lookup is done early on in the processing of client
 727  * hello and other operations depend on the result we need to handle any TLS
 728  * session ticket extension at the same time.
 729  */
 730
 731 int tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
 732                                 const unsigned char *limit, SSL_SESSION **ret)
 733         {
 734         /* Point after session ID in client hello */
 735         const unsigned char *p = session_id + len;
 736         unsigned short i;
 737
 738         /* If tickets disabled behave as if no ticket present
 739          * to permit stateful resumption.
 740          */
 741         if (SSL_get_options(s) & SSL_OP_NO_TICKET)
 742                 return 1;
 743
 744         if ((s->version <= SSL3_VERSION) || !limit)
 745                 return 1;
 746         if (p >= limit)
 747                 return -1;
 748         /* Skip past cipher list */
 749         n2s(p, i);
 750         p+= i;
 751         if (p >= limit)
 752                 return -1;
 753         /* Skip past compression algorithm list */
 754         i = *(p++);
 755         p += i;
 756         if (p > limit)
 757                 return -1;
 758         /* Now at start of extensions */
 759         if ((p + 2) >= limit)
 760                 return 1;
 761         n2s(p, i);
 762         while ((p + 4) <= limit)
 763                 {
 764                 unsigned short type, size;
 765                 n2s(p, type);
 766                 n2s(p, size);
 767                 if (p + size > limit)
 768                         return 1;
 769                 if (type == TLSEXT_TYPE_session_ticket)
 770                         {
 771                         /* If zero length note client will accept a ticket
 772                          * and indicate cache miss to trigger full handshake
 773                          */
 774                         if (size == 0)
 775                                 {
 776                                 s->tlsext_ticket_expected = 1;
 777                                 return 0;       /* Cache miss */
 778                                 }
 779                         return tls_decrypt_ticket(s, p, size, session_id, len,
 780                                                                         ret);
 781                         }
 782                 p += size;
 783                 }
 784         return 1;
 785         }
 786
 787 static int tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen,
 788                                 const unsigned char *sess_id, int sesslen,
 789                                 SSL_SESSION **psess)
 790         {
 791         SSL_SESSION *sess;
 792         unsigned char *sdec;
 793         const unsigned char *p;
 794         int slen, mlen, renew_ticket = 0;
 795         unsigned char tick_hmac[EVP_MAX_MD_SIZE];
 796         HMAC_CTX hctx;
 797         EVP_CIPHER_CTX ctx;
 798         /* Need at least keyname + iv + some encrypted data */
 799         if (eticklen < 48)
 800                 goto tickerr;
 801         /* Initialize session ticket encryption and HMAC contexts */
 802         HMAC_CTX_init(&hctx);
 803         EVP_CIPHER_CTX_init(&ctx);
 804         if (s->ctx->tlsext_ticket_key_cb)
 805                 {
 806                 unsigned char *nctick = (unsigned char *)etick;
 807                 int rv = s->ctx->tlsext_ticket_key_cb(s, nctick, nctick + 16,
 808                                                         &ctx, &hctx, 0);
 809                 if (rv < 0)
 810                         return -1;
 811                 if (rv == 0)
 812                         goto tickerr;
 813                 if (rv == 2)
 814                         renew_ticket = 1;
 815                 }
 816         else
 817                 {
 818                 /* Check key name matches */
 819                 if (memcmp(etick, s->ctx->tlsext_tick_key_name, 16))
 820                         goto tickerr;
 821                 HMAC_Init_ex(&hctx, s->ctx->tlsext_tick_hmac_key, 16,
 822                                         tlsext_tick_md(), NULL);
 823                 EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
 824                                 s->ctx->tlsext_tick_aes_key, etick + 16);
 825                 }
 826         /* Attempt to process session ticket, first conduct sanity and
 827          * integrity checks on ticket.
 828          */
 829         mlen = HMAC_size(&hctx);
 830         eticklen -= mlen;
 831         /* Check HMAC of encrypted ticket */
 832         HMAC_Update(&hctx, etick, eticklen);
 833         HMAC_Final(&hctx, tick_hmac, NULL);
 834         HMAC_CTX_cleanup(&hctx);
 835         if (memcmp(tick_hmac, etick + eticklen, mlen))
 836                 goto tickerr;
 837         /* Attempt to decrypt session data */
 838         /* Move p after IV to start of encrypted ticket, update length */
 839         p = etick + 16 + EVP_CIPHER_CTX_iv_length(&ctx);
 840         eticklen -= 16 + EVP_CIPHER_CTX_iv_length(&ctx);
 841         sdec = OPENSSL_malloc(eticklen);
 842         if (!sdec)
 843                 {
 844                 EVP_CIPHER_CTX_cleanup(&ctx);
 845                 return -1;
 846                 }
 847         EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen);
 848         if (EVP_DecryptFinal(&ctx, sdec + slen, &mlen) <= 0)
 849                 goto tickerr;
 850         slen += mlen;
 851         EVP_CIPHER_CTX_cleanup(&ctx);
 852         p = sdec;
 853
 854         sess = d2i_SSL_SESSION(NULL, &p, slen);
 855         OPENSSL_free(sdec);
 856         if (sess)
 857                 {
 858                 /* The session ID if non-empty is used by some clients to
 859                  * detect that the ticket has been accepted. So we copy it to
 860                  * the session structure. If it is empty set length to zero
 861                  * as required by standard.
 862                  */
 863                 if (sesslen)
 864                         memcpy(sess->session_id, sess_id, sesslen);
 865                 sess->session_id_length = sesslen;
 866                 *psess = sess;
 867                 s->tlsext_ticket_expected = renew_ticket;
 868                 return 1;
 869                 }
 870         /* If session decrypt failure indicate a cache miss and set state to
 871          * send a new ticket
 872          */
 873         tickerr:
 874         s->tlsext_ticket_expected = 1;
 875         return 0;
 876         }
 877
 878 #endif