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 RI if renegotiating */
 179         if (s->new_session)
 180           {
 181           int el;
 182
 183           if(!ssl_add_clienthello_renegotiate_ext(s, 0, &el, 0))
 184               {
 185               SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 186               return NULL;
 187               }
 188
 189           if((limit - p - 4 - el) < 0) return NULL;
 190
 191           s2n(TLSEXT_TYPE_renegotiate,ret);
 192           s2n(el,ret);
 193
 194           if(!ssl_add_clienthello_renegotiate_ext(s, ret, &el, el))
 195               {
 196               SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 197               return NULL;
 198               }
 199
 200           ret += el;
 201         }
 202
 203
 204         if (!(SSL_get_options(s) & SSL_OP_NO_TICKET))
 205                 {
 206                 int ticklen;
 207                 if (!s->new_session && s->session && s->session->tlsext_tick)
 208                         ticklen = s->session->tlsext_ticklen;
 209                 else
 210                         ticklen = 0;
 211                 /* Check for enough room 2 for extension type, 2 for len
 212                  * rest for ticket
 213                  */
 214                 if (limit - ret - 4 - ticklen < 0)
 215                         return NULL;
 216                 s2n(TLSEXT_TYPE_session_ticket,ret);
 217                 s2n(ticklen,ret);
 218                 if (ticklen)
 219                         {
 220                         memcpy(ret, s->session->tlsext_tick, ticklen);
 221                         ret += ticklen;
 222                         }
 223                 }
 224
 225         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp &&
 226             s->version != DTLS1_VERSION)
 227                 {
 228                 int i;
 229                 long extlen, idlen, itmp;
 230                 OCSP_RESPID *id;
 231
 232                 idlen = 0;
 233                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
 234                         {
 235                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
 236                         itmp = i2d_OCSP_RESPID(id, NULL);
 237                         if (itmp <= 0)
 238                                 return NULL;
 239                         idlen += itmp + 2;
 240                         }
 241
 242                 if (s->tlsext_ocsp_exts)
 243                         {
 244                         extlen = i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, NULL);
 245                         if (extlen < 0)
 246                                 return NULL;
 247                         }
 248                 else
 249                         extlen = 0;
 250
 251                 if ((long)(limit - ret - 7 - extlen - idlen) < 0) return NULL;
 252                 s2n(TLSEXT_TYPE_status_request, ret);
 253                 if (extlen + idlen > 0xFFF0)
 254                         return NULL;
 255                 s2n(extlen + idlen + 5, ret);
 256                 *(ret++) = TLSEXT_STATUSTYPE_ocsp;
 257                 s2n(idlen, ret);
 258                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
 259                         {
 260                         /* save position of id len */
 261                         unsigned char *q = ret;
 262                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
 263                         /* skip over id len */
 264                         ret += 2;
 265                         itmp = i2d_OCSP_RESPID(id, &ret);
 266                         /* write id len */
 267                         s2n(itmp, q);
 268                         }
 269                 s2n(extlen, ret);
 270                 if (extlen > 0)
 271                         i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
 272                 }
 273
 274         if ((extdatalen = ret-p-2)== 0)
 275                 return p;
 276
 277         s2n(extdatalen,p);
 278         return ret;
 279         }
 280
 281 unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
 282         {
 283         int extdatalen=0;
 284         unsigned char *ret = p;
 285
 286         /* don't add extensions for SSLv3, unless doing secure renegotiation */
 287         if (s->version == SSL3_VERSION && !s->s3->send_connection_binding)
 288                 return p;
 289
 290         ret+=2;
 291         if (ret>=limit) return NULL; /* this really never occurs, but ... */
 292
 293         if (!s->hit && s->servername_done == 1 && s->session->tlsext_hostname != NULL)
 294                 {
 295                 if (limit - ret - 4 < 0) return NULL;
 296
 297                 s2n(TLSEXT_TYPE_server_name,ret);
 298                 s2n(0,ret);
 299                 }
 300
 301         if(s->s3->send_connection_binding)
 302         {
 303           int el;
 304
 305           if(!ssl_add_serverhello_renegotiate_ext(s, 0, &el, 0))
 306               {
 307               SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 308               return NULL;
 309               }
 310
 311           if((limit - p - 4 - el) < 0) return NULL;
 312
 313           s2n(TLSEXT_TYPE_renegotiate,ret);
 314           s2n(el,ret);
 315
 316           if(!ssl_add_serverhello_renegotiate_ext(s, ret, &el, el))
 317               {
 318               SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 319               return NULL;
 320               }
 321
 322           ret += el;
 323         }
 324
 325         if (s->tlsext_ticket_expected
 326                 && !(SSL_get_options(s) & SSL_OP_NO_TICKET))
 327                 {
 328                 if (limit - ret - 4 < 0) return NULL;
 329                 s2n(TLSEXT_TYPE_session_ticket,ret);
 330                 s2n(0,ret);
 331                 }
 332
 333         if (s->tlsext_status_expected)
 334                 {
 335                 if ((long)(limit - ret - 4) < 0) return NULL;
 336                 s2n(TLSEXT_TYPE_status_request,ret);
 337                 s2n(0,ret);
 338                 }
 339
 340         if ((extdatalen = ret-p-2)== 0)
 341                 return p;
 342
 343         s2n(extdatalen,p);
 344         return ret;
 345         }
 346
 347 int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
 348         {
 349         unsigned short type;
 350         unsigned short size;
 351         unsigned short len;
 352         unsigned char *data = *p;
 353         int renegotiate_seen = 0;
 354
 355         s->servername_done = 0;
 356         s->tlsext_status_type = -1;
 357
 358         if (data >= (d+n-2))
 359                 goto ri_check;
 360
 361         n2s(data,len);
 362
 363         if (data > (d+n-len))
 364                 goto ri_check;
 365
 366         while (data <= (d+n-4))
 367                 {
 368                 n2s(data,type);
 369                 n2s(data,size);
 370
 371                 if (data+size > (d+n))
 372                         goto ri_check;
 373
 374                 if (s->tlsext_debug_cb)
 375                         s->tlsext_debug_cb(s, 0, type, data, size,
 376                                                 s->tlsext_debug_arg);
 377 /* The servername extension is treated as follows:
 378
 379    - Only the hostname type is supported with a maximum length of 255.
 380    - The servername is rejected if too long or if it contains zeros,
 381      in which case an fatal alert is generated.
 382    - The servername field is maintained together with the session cache.
 383    - When a session is resumed, the servername call back invoked in order
 384      to allow the application to position itself to the right context.
 385    - The servername is acknowledged if it is new for a session or when
 386      it is identical to a previously used for the same session.
 387      Applications can control the behaviour.  They can at any time
 388      set a 'desirable' servername for a new SSL object. This can be the
 389      case for example with HTTPS when a Host: header field is received and
 390      a renegotiation is requested. In this case, a possible servername
 391      presented in the new client hello is only acknowledged if it matches
 392      the value of the Host: field.
 393    - Applications must  use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
 394      if they provide for changing an explicit servername context for the session,
 395      i.e. when the session has been established with a servername extension.
 396    - On session reconnect, the servername extension may be absent.
 397
 398 */
 399
 400                 if (type == TLSEXT_TYPE_server_name)
 401                         {
 402                         unsigned char *sdata;
 403                         int servname_type;
 404                         int dsize;
 405
 406                         if (size < 2)
 407                                 {
 408                                 *al = SSL_AD_DECODE_ERROR;
 409                                 return 0;
 410                                 }
 411                         n2s(data,dsize);
 412                         size -= 2;
 413                         if (dsize > size  )
 414                                 {
 415                                 *al = SSL_AD_DECODE_ERROR;
 416                                 return 0;
 417                                 }
 418
 419                         sdata = data;
 420                         while (dsize > 3)
 421                                 {
 422                                 servname_type = *(sdata++);
 423                                 n2s(sdata,len);
 424                                 dsize -= 3;
 425
 426                                 if (len > dsize)
 427                                         {
 428                                         *al = SSL_AD_DECODE_ERROR;
 429                                         return 0;
 430                                         }
 431                                 if (s->servername_done == 0)
 432                                 switch (servname_type)
 433                                         {
 434                                 case TLSEXT_NAMETYPE_host_name:
 435                                         if (!s->hit)
 436                                                 {
 437                                                 if(s->session->tlsext_hostname)
 438                                                         {
 439                                                         *al = SSL_AD_DECODE_ERROR;
 440                                                         return 0;
 441                                                         }
 442                                                 if (len > TLSEXT_MAXLEN_host_name)
 443                                                         {
 444                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
 445                                                         return 0;
 446                                                         }
 447                                                 if ((s->session->tlsext_hostname = OPENSSL_malloc(len+1)) == NULL)
 448                                                         {
 449                                                         *al = TLS1_AD_INTERNAL_ERROR;
 450                                                         return 0;
 451                                                         }
 452                                                 memcpy(s->session->tlsext_hostname, sdata, len);
 453                                                 s->session->tlsext_hostname[len]='\0';
 454                                                 if (strlen(s->session->tlsext_hostname) != len) {
 455                                                         OPENSSL_free(s->session->tlsext_hostname);
 456                                                         s->session->tlsext_hostname = NULL;
 457                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
 458                                                         return 0;
 459                                                 }
 460                                                 s->servername_done = 1;
 461
 462                                                 }
 463                                         else
 464                                                 s->servername_done = s->session->tlsext_hostname
 465                                                         && strlen(s->session->tlsext_hostname) == len
 466                                                         && strncmp(s->session->tlsext_hostname, (char *)sdata, len) == 0;
 467
 468                                         break;
 469
 470                                 default:
 471                                         break;
 472                                         }
 473
 474                                 dsize -= len;
 475                                 }
 476                         if (dsize != 0)
 477                                 {
 478                                 *al = SSL_AD_DECODE_ERROR;
 479                                 return 0;
 480                                 }
 481
 482                         }
 483                 else if (type == TLSEXT_TYPE_renegotiate)
 484                         {
 485                         if(!ssl_parse_clienthello_renegotiate_ext(s, data, size, al))
 486                                 return 0;
 487                         renegotiate_seen = 1;
 488                         }
 489                 else if (type == TLSEXT_TYPE_status_request &&
 490                          s->version != DTLS1_VERSION && s->ctx->tlsext_status_cb)
 491                         {
 492
 493                         if (size < 5)
 494                                 {
 495                                 *al = SSL_AD_DECODE_ERROR;
 496                                 return 0;
 497                                 }
 498
 499                         s->tlsext_status_type = *data++;
 500                         size--;
 501                         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
 502                                 {
 503                                 const unsigned char *sdata;
 504                                 int dsize;
 505                                 /* Read in responder_id_list */
 506                                 n2s(data,dsize);
 507                                 size -= 2;
 508                                 if (dsize > size  )
 509                                         {
 510                                         *al = SSL_AD_DECODE_ERROR;
 511                                         return 0;
 512                                         }
 513                                 while (dsize > 0)
 514                                         {
 515                                         OCSP_RESPID *id;
 516                                         int idsize;
 517                                         if (dsize < 4)
 518                                                 {
 519                                                 *al = SSL_AD_DECODE_ERROR;
 520                                                 return 0;
 521                                                 }
 522                                         n2s(data, idsize);
 523                                         dsize -= 2 + idsize;
 524                                         size -= 2 + idsize;
 525                                         if (dsize < 0)
 526                                                 {
 527                                                 *al = SSL_AD_DECODE_ERROR;
 528                                                 return 0;
 529                                                 }
 530                                         sdata = data;
 531                                         data += idsize;
 532                                         id = d2i_OCSP_RESPID(NULL,
 533                                                                 &sdata, idsize);
 534                                         if (!id)
 535                                                 {
 536                                                 *al = SSL_AD_DECODE_ERROR;
 537                                                 return 0;
 538                                                 }
 539                                         if (data != sdata)
 540                                                 {
 541                                                 OCSP_RESPID_free(id);
 542                                                 *al = SSL_AD_DECODE_ERROR;
 543                                                 return 0;
 544                                                 }
 545                                         if (!s->tlsext_ocsp_ids
 546                                                 && !(s->tlsext_ocsp_ids =
 547                                                 sk_OCSP_RESPID_new_null()))
 548                                                 {
 549                                                 OCSP_RESPID_free(id);
 550                                                 *al = SSL_AD_INTERNAL_ERROR;
 551                                                 return 0;
 552                                                 }
 553                                         if (!sk_OCSP_RESPID_push(
 554                                                         s->tlsext_ocsp_ids, id))
 555                                                 {
 556                                                 OCSP_RESPID_free(id);
 557                                                 *al = SSL_AD_INTERNAL_ERROR;
 558                                                 return 0;
 559                                                 }
 560                                         }
 561
 562                                 /* Read in request_extensions */
 563                                 if (size < 2)
 564                                         {
 565                                         *al = SSL_AD_DECODE_ERROR;
 566                                         return 0;
 567                                         }
 568                                 n2s(data,dsize);
 569                                 size -= 2;
 570                                 if (dsize != size)
 571                                         {
 572                                         *al = SSL_AD_DECODE_ERROR;
 573                                         return 0;
 574                                         }
 575                                 sdata = data;
 576                                 if (dsize > 0)
 577                                         {
 578                                         if (s->tlsext_ocsp_exts)
 579                                                 {
 580                                                 sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts,
 581                                                                            X509_EXTENSION_free);
 582                                                 }
 583
 584                                         s->tlsext_ocsp_exts =
 585                                                 d2i_X509_EXTENSIONS(NULL,
 586                                                         &sdata, dsize);
 587                                         if (!s->tlsext_ocsp_exts
 588                                                 || (data + dsize != sdata))
 589                                                 {
 590                                                 *al = SSL_AD_DECODE_ERROR;
 591                                                 return 0;
 592                                                 }
 593                                         }
 594                                 }
 595                                 /* We don't know what to do with any other type
 596                                 * so ignore it.
 597                                 */
 598                                 else
 599                                         s->tlsext_status_type = -1;
 600                         }
 601
 602                 /* session ticket processed earlier */
 603
 604                 data+=size;
 605                 }
 606         *p = data;
 607
 608         ri_check:
 609
 610         /* Need RI if renegotiating */
 611
 612         if (!renegotiate_seen && s->new_session &&
 613                 !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
 614                 {
 615                 *al = SSL_AD_HANDSHAKE_FAILURE;
 616                 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT,
 617                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
 618                 return 0;
 619                 }
 620
 621         return 1;
 622         }
 623
 624 int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
 625         {
 626         unsigned short length;
 627         unsigned short type;
 628         unsigned short size;
 629         unsigned char *data = *p;
 630         int tlsext_servername = 0;
 631         int renegotiate_seen = 0;
 632
 633         if (data >= (d+n-2))
 634                 goto ri_check;
 635
 636         n2s(data,length);
 637         if (data+length != d+n)
 638                 {
 639                 *al = SSL_AD_DECODE_ERROR;
 640                 return 0;
 641                 }
 642
 643         while(data <= (d+n-4))
 644                 {
 645                 n2s(data,type);
 646                 n2s(data,size);
 647
 648                 if (data+size > (d+n))
 649                         goto ri_check;
 650
 651                 if (s->tlsext_debug_cb)
 652                         s->tlsext_debug_cb(s, 1, type, data, size,
 653                                                 s->tlsext_debug_arg);
 654
 655                 if (type == TLSEXT_TYPE_server_name)
 656                         {
 657                         if (s->tlsext_hostname == NULL || size > 0)
 658                                 {
 659                                 *al = TLS1_AD_UNRECOGNIZED_NAME;
 660                                 return 0;
 661                                 }
 662                         tlsext_servername = 1;
 663                         }
 664                 else if (type == TLSEXT_TYPE_session_ticket)
 665                         {
 666                         if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
 667                                 || (size > 0))
 668                                 {
 669                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
 670                                 return 0;
 671                                 }
 672                         s->tlsext_ticket_expected = 1;
 673                         }
 674                 else if (type == TLSEXT_TYPE_status_request &&
 675                          s->version != DTLS1_VERSION)
 676                         {
 677                         /* MUST be empty and only sent if we've requested
 678                          * a status request message.
 679                          */
 680                         if ((s->tlsext_status_type == -1) || (size > 0))
 681                                 {
 682                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
 683                                 return 0;
 684                                 }
 685                         /* Set flag to expect CertificateStatus message */
 686                         s->tlsext_status_expected = 1;
 687                         }
 688                 else if (type == TLSEXT_TYPE_renegotiate)
 689                         {
 690                         if(!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
 691                                 return 0;
 692                         renegotiate_seen = 1;
 693                         }
 694                 data+=size;
 695                 }
 696
 697         if (data != d+n)
 698                 {
 699                 *al = SSL_AD_DECODE_ERROR;
 700                 return 0;
 701                 }
 702
 703         if (!s->hit && tlsext_servername == 1)
 704                 {
 705                 if (s->tlsext_hostname)
 706                         {
 707                         if (s->session->tlsext_hostname == NULL)
 708                                 {
 709                                 s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);
 710                                 if (!s->session->tlsext_hostname)
 711                                         {
 712                                         *al = SSL_AD_UNRECOGNIZED_NAME;
 713                                         return 0;
 714                                         }
 715                                 }
 716                         else
 717                                 {
 718                                 *al = SSL_AD_DECODE_ERROR;
 719                                 return 0;
 720                                 }
 721                         }
 722                 }
 723
 724         *p = data;
 725
 726         ri_check:
 727
 728         /* Determine if we need to see RI. Strictly speaking if we want to
 729          * avoid an attack we should *always* see RI even on initial server
 730          * hello because the client doesn't see any renegotiation during an
 731          * attack. However this would mean we could not connect to any server
 732          * which doesn't support RI so for the immediate future tolerate RI
 733          * absence on initial connect only.
 734          */
 735         if (!renegotiate_seen
 736                 && !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
 737                 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
 738                 {
 739                 *al = SSL_AD_HANDSHAKE_FAILURE;
 740                 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT,
 741                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
 742                 return 0;
 743                 }
 744
 745         return 1;
 746         }
 747
 748 int ssl_check_clienthello_tlsext_early(SSL *s)
 749         {
 750         int ret=SSL_TLSEXT_ERR_NOACK;
 751         int al = SSL_AD_UNRECOGNIZED_NAME;
 752
 753         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
 754                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
 755         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
 756                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
 757
 758         switch (ret)
 759                 {
 760                 case SSL_TLSEXT_ERR_ALERT_FATAL:
 761                         ssl3_send_alert(s, SSL3_AL_FATAL, al);
 762                         return -1;
 763
 764                 case SSL_TLSEXT_ERR_ALERT_WARNING:
 765                         ssl3_send_alert(s, SSL3_AL_WARNING, al);
 766                         return 1;
 767
 768                 case SSL_TLSEXT_ERR_NOACK:
 769                         s->servername_done = 0;
 770
 771                 default:
 772                         return 1;
 773                 }
 774         }
 775
 776 int ssl_check_clienthello_tlsext_late(SSL *s)
 777         {
 778         int ret = SSL_TLSEXT_ERR_OK;
 779         int al;
 780
 781         /* If status request then ask callback what to do.
 782          * Note: this must be called after servername callbacks in case
 783          * the certificate has changed, and must be called after the cipher
 784          * has been chosen because this may influence which certificate is sent
 785          */
 786         if (s->tlsext_status_type != -1 && s->ctx && s->ctx->tlsext_status_cb)
 787                 {
 788                 int r;
 789                 CERT_PKEY *certpkey;
 790                 certpkey = ssl_get_server_send_pkey(s);
 791                 /* If no certificate can't return certificate status */
 792                 if (certpkey == NULL)
 793                         {
 794                         s->tlsext_status_expected = 0;
 795                         return 1;
 796                         }
 797                 /* Set current certificate to one we will use so
 798                  * SSL_get_certificate et al can pick it up.
 799                  */
 800                 s->cert->key = certpkey;
 801                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
 802                 switch (r)
 803                         {
 804                         /* We don't want to send a status request response */
 805                         case SSL_TLSEXT_ERR_NOACK:
 806                                 s->tlsext_status_expected = 0;
 807                                 break;
 808                         /* status request response should be sent */
 809                         case SSL_TLSEXT_ERR_OK:
 810                                 if (s->tlsext_ocsp_resp)
 811                                         s->tlsext_status_expected = 1;
 812                                 else
 813                                         s->tlsext_status_expected = 0;
 814                                 break;
 815                         /* something bad happened */
 816                         case SSL_TLSEXT_ERR_ALERT_FATAL:
 817                                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
 818                                 al = SSL_AD_INTERNAL_ERROR;
 819                                 goto err;
 820                         }
 821                 }
 822         else
 823                 s->tlsext_status_expected = 0;
 824
 825  err:
 826         switch (ret)
 827                 {
 828                 case SSL_TLSEXT_ERR_ALERT_FATAL:
 829                         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 830                         return -1;
 831
 832                 case SSL_TLSEXT_ERR_ALERT_WARNING:
 833                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
 834                         return 1;
 835
 836                 default:
 837                         return 1;
 838                 }
 839         }
 840
 841 int ssl_check_serverhello_tlsext(SSL *s)
 842         {
 843         int ret=SSL_TLSEXT_ERR_NOACK;
 844         int al = SSL_AD_UNRECOGNIZED_NAME;
 845
 846         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
 847                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
 848         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
 849                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
 850
 851         /* If we've requested certificate status and we wont get one
 852          * tell the callback
 853          */
 854         if ((s->tlsext_status_type != -1) && !(s->tlsext_status_expected)
 855                         && s->ctx->tlsext_status_cb)
 856                 {
 857                 int r;
 858                 /* Set resp to NULL, resplen to -1 so callback knows
 859                  * there is no response.
 860                  */
 861                 if (s->tlsext_ocsp_resp)
 862                         {
 863                         OPENSSL_free(s->tlsext_ocsp_resp);
 864                         s->tlsext_ocsp_resp = NULL;
 865                         }
 866                 s->tlsext_ocsp_resplen = -1;
 867                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
 868                 if (r == 0)
 869                         {
 870                         al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
 871                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
 872                         }
 873                 if (r < 0)
 874                         {
 875                         al = SSL_AD_INTERNAL_ERROR;
 876                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
 877                         }
 878                 }
 879
 880         switch (ret)
 881                 {
 882                 case SSL_TLSEXT_ERR_ALERT_FATAL:
 883                         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 884                         return -1;
 885
 886                 case SSL_TLSEXT_ERR_ALERT_WARNING:
 887                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
 888                         return 1;
 889
 890                 case SSL_TLSEXT_ERR_NOACK:
 891                         s->servername_done=0;
 892                         default:
 893                 return 1;
 894                 }
 895         }
 896
 897 /* Since the server cache lookup is done early on in the processing of client
 898  * hello and other operations depend on the result we need to handle any TLS
 899  * session ticket extension at the same time.
 900  */
 901
 902 int tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
 903                                 const unsigned char *limit, SSL_SESSION **ret)
 904         {
 905         /* Point after session ID in client hello */
 906         const unsigned char *p = session_id + len;
 907         unsigned short i;
 908
 909         /* If tickets disabled behave as if no ticket present
 910          * to permit stateful resumption.
 911          */
 912         if (SSL_get_options(s) & SSL_OP_NO_TICKET)
 913                 return 1;
 914
 915         if ((s->version <= SSL3_VERSION) || !limit)
 916                 return 1;
 917         if (p >= limit)
 918                 return -1;
 919         /* Skip past DTLS cookie */
 920         if (s->version == DTLS1_VERSION || s->version == DTLS1_BAD_VER)
 921                 {
 922                 i = *(p++);
 923                 p+= i;
 924                 if (p >= limit)
 925                         return -1;
 926                 }
 927         /* Skip past cipher list */
 928         n2s(p, i);
 929         p+= i;
 930         if (p >= limit)
 931                 return -1;
 932         /* Skip past compression algorithm list */
 933         i = *(p++);
 934         p += i;
 935         if (p > limit)
 936                 return -1;
 937         /* Now at start of extensions */
 938         if ((p + 2) >= limit)
 939                 return 1;
 940         n2s(p, i);
 941         while ((p + 4) <= limit)
 942                 {
 943                 unsigned short type, size;
 944                 n2s(p, type);
 945                 n2s(p, size);
 946                 if (p + size > limit)
 947                         return 1;
 948                 if (type == TLSEXT_TYPE_session_ticket)
 949                         {
 950                         /* If zero length note client will accept a ticket
 951                          * and indicate cache miss to trigger full handshake
 952                          */
 953                         if (size == 0)
 954                                 {
 955                                 s->tlsext_ticket_expected = 1;
 956                                 return 0;       /* Cache miss */
 957                                 }
 958                         return tls_decrypt_ticket(s, p, size, session_id, len,
 959                                                                         ret);
 960                         }
 961                 p += size;
 962                 }
 963         return 1;
 964         }
 965
 966 static int tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen,
 967                                 const unsigned char *sess_id, int sesslen,
 968                                 SSL_SESSION **psess)
 969         {
 970         SSL_SESSION *sess;
 971         unsigned char *sdec;
 972         const unsigned char *p;
 973         int slen, mlen, renew_ticket = 0;
 974         unsigned char tick_hmac[EVP_MAX_MD_SIZE];
 975         HMAC_CTX hctx;
 976         EVP_CIPHER_CTX ctx;
 977         SSL_CTX *tctx = s->initial_ctx;
 978         /* Need at least keyname + iv + some encrypted data */
 979         if (eticklen < 48)
 980                 goto tickerr;
 981         /* Initialize session ticket encryption and HMAC contexts */
 982         HMAC_CTX_init(&hctx);
 983         EVP_CIPHER_CTX_init(&ctx);
 984         if (tctx->tlsext_ticket_key_cb)
 985                 {
 986                 unsigned char *nctick = (unsigned char *)etick;
 987                 int rv = tctx->tlsext_ticket_key_cb(s, nctick, nctick + 16,
 988                                                         &ctx, &hctx, 0);
 989                 if (rv < 0)
 990                         return -1;
 991                 if (rv == 0)
 992                         goto tickerr;
 993                 if (rv == 2)
 994                         renew_ticket = 1;
 995                 }
 996         else
 997                 {
 998                 /* Check key name matches */
 999                 if (memcmp(etick, tctx->tlsext_tick_key_name, 16))
1000                         goto tickerr;
1001                 HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,
1002                                         tlsext_tick_md(), NULL);
1003                 EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
1004                                 tctx->tlsext_tick_aes_key, etick + 16);
1005                 }
1006         /* Attempt to process session ticket, first conduct sanity and
1007          * integrity checks on ticket.
1008          */
1009         mlen = HMAC_size(&hctx);
1010         eticklen -= mlen;
1011         /* Check HMAC of encrypted ticket */
1012         HMAC_Update(&hctx, etick, eticklen);
1013         HMAC_Final(&hctx, tick_hmac, NULL);
1014         HMAC_CTX_cleanup(&hctx);
1015         if (memcmp(tick_hmac, etick + eticklen, mlen))
1016                 goto tickerr;
1017         /* Attempt to decrypt session data */
1018         /* Move p after IV to start of encrypted ticket, update length */
1019         p = etick + 16 + EVP_CIPHER_CTX_iv_length(&ctx);
1020         eticklen -= 16 + EVP_CIPHER_CTX_iv_length(&ctx);
1021         sdec = OPENSSL_malloc(eticklen);
1022         if (!sdec)
1023                 {
1024                 EVP_CIPHER_CTX_cleanup(&ctx);
1025                 return -1;
1026                 }
1027         EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen);
1028         if (EVP_DecryptFinal(&ctx, sdec + slen, &mlen) <= 0)
1029                 goto tickerr;
1030         slen += mlen;
1031         EVP_CIPHER_CTX_cleanup(&ctx);
1032         p = sdec;
1033
1034         sess = d2i_SSL_SESSION(NULL, &p, slen);
1035         OPENSSL_free(sdec);
1036         if (sess)
1037                 {
1038                 /* The session ID if non-empty is used by some clients to
1039                  * detect that the ticket has been accepted. So we copy it to
1040                  * the session structure. If it is empty set length to zero
1041                  * as required by standard.
1042                  */
1043                 if (sesslen)
1044                         memcpy(sess->session_id, sess_id, sesslen);
1045                 sess->session_id_length = sesslen;
1046                 *psess = sess;
1047                 s->tlsext_ticket_expected = renew_ticket;
1048                 return 1;
1049                 }
1050         /* If session decrypt failure indicate a cache miss and set state to
1051          * send a new ticket
1052          */
1053         tickerr:
1054         s->tlsext_ticket_expected = 1;
1055         return 0;
1056         }
1057
1058 #endif