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                 {
 359                 if (s->new_session
 360                         && !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
 361                         {
 362                         /* We should always see one extension: the renegotiate extension */
 363                         SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
 364                         *al = SSL_AD_ILLEGAL_PARAMETER; /* is this the right alert? */
 365                         return 0;
 366                         }
 367                 return 1;
 368                 }
 369         n2s(data,len);
 370
 371         if (data > (d+n-len))
 372                 return 1;
 373
 374         while (data <= (d+n-4))
 375                 {
 376                 n2s(data,type);
 377                 n2s(data,size);
 378
 379                 if (data+size > (d+n))
 380                         return 1;
 381
 382                 if (s->tlsext_debug_cb)
 383                         s->tlsext_debug_cb(s, 0, type, data, size,
 384                                                 s->tlsext_debug_arg);
 385 /* The servername extension is treated as follows:
 386
 387    - Only the hostname type is supported with a maximum length of 255.
 388    - The servername is rejected if too long or if it contains zeros,
 389      in which case an fatal alert is generated.
 390    - The servername field is maintained together with the session cache.
 391    - When a session is resumed, the servername call back invoked in order
 392      to allow the application to position itself to the right context.
 393    - The servername is acknowledged if it is new for a session or when
 394      it is identical to a previously used for the same session.
 395      Applications can control the behaviour.  They can at any time
 396      set a 'desirable' servername for a new SSL object. This can be the
 397      case for example with HTTPS when a Host: header field is received and
 398      a renegotiation is requested. In this case, a possible servername
 399      presented in the new client hello is only acknowledged if it matches
 400      the value of the Host: field.
 401    - Applications must  use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
 402      if they provide for changing an explicit servername context for the session,
 403      i.e. when the session has been established with a servername extension.
 404    - On session reconnect, the servername extension may be absent.
 405
 406 */
 407
 408                 if (type == TLSEXT_TYPE_server_name)
 409                         {
 410                         unsigned char *sdata;
 411                         int servname_type;
 412                         int dsize;
 413
 414                         if (size < 2)
 415                                 {
 416                                 *al = SSL_AD_DECODE_ERROR;
 417                                 return 0;
 418                                 }
 419                         n2s(data,dsize);
 420                         size -= 2;
 421                         if (dsize > size  )
 422                                 {
 423                                 *al = SSL_AD_DECODE_ERROR;
 424                                 return 0;
 425                                 }
 426
 427                         sdata = data;
 428                         while (dsize > 3)
 429                                 {
 430                                 servname_type = *(sdata++);
 431                                 n2s(sdata,len);
 432                                 dsize -= 3;
 433
 434                                 if (len > dsize)
 435                                         {
 436                                         *al = SSL_AD_DECODE_ERROR;
 437                                         return 0;
 438                                         }
 439                                 if (s->servername_done == 0)
 440                                 switch (servname_type)
 441                                         {
 442                                 case TLSEXT_NAMETYPE_host_name:
 443                                         if (s->session->tlsext_hostname == NULL)
 444                                                 {
 445                                                 if (len > TLSEXT_MAXLEN_host_name ||
 446                                                         ((s->session->tlsext_hostname = OPENSSL_malloc(len+1)) == NULL))
 447                                                         {
 448                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
 449                                                         return 0;
 450                                                         }
 451                                                 memcpy(s->session->tlsext_hostname, sdata, len);
 452                                                 s->session->tlsext_hostname[len]='\0';
 453                                                 if (strlen(s->session->tlsext_hostname) != len) {
 454                                                         OPENSSL_free(s->session->tlsext_hostname);
 455                                                         s->session->tlsext_hostname = NULL;
 456                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
 457                                                         return 0;
 458                                                 }
 459                                                 s->servername_done = 1;
 460
 461                                                 }
 462                                         else
 463                                                 s->servername_done = strlen(s->session->tlsext_hostname) == len
 464                                                         && strncmp(s->session->tlsext_hostname, (char *)sdata, len) == 0;
 465
 466                                         break;
 467
 468                                 default:
 469                                         break;
 470                                         }
 471
 472                                 dsize -= len;
 473                                 }
 474                         if (dsize != 0)
 475                                 {
 476                                 *al = SSL_AD_DECODE_ERROR;
 477                                 return 0;
 478                                 }
 479
 480                         }
 481                 else if (type == TLSEXT_TYPE_renegotiate)
 482                         {
 483                         if(!ssl_parse_clienthello_renegotiate_ext(s, data, size, al))
 484                                 return 0;
 485                         renegotiate_seen = 1;
 486                         }
 487                 else if (type == TLSEXT_TYPE_status_request &&
 488                          s->version != DTLS1_VERSION && s->ctx->tlsext_status_cb)
 489                         {
 490
 491                         if (size < 5)
 492                                 {
 493                                 *al = SSL_AD_DECODE_ERROR;
 494                                 return 0;
 495                                 }
 496
 497                         s->tlsext_status_type = *data++;
 498                         size--;
 499                         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
 500                                 {
 501                                 const unsigned char *sdata;
 502                                 int dsize;
 503                                 /* Read in responder_id_list */
 504                                 n2s(data,dsize);
 505                                 size -= 2;
 506                                 if (dsize > size  )
 507                                         {
 508                                         *al = SSL_AD_DECODE_ERROR;
 509                                         return 0;
 510                                         }
 511                                 while (dsize > 0)
 512                                         {
 513                                         OCSP_RESPID *id;
 514                                         int idsize;
 515                                         if (dsize < 4)
 516                                                 {
 517                                                 *al = SSL_AD_DECODE_ERROR;
 518                                                 return 0;
 519                                                 }
 520                                         n2s(data, idsize);
 521                                         dsize -= 2 + idsize;
 522                                         if (dsize < 0)
 523                                                 {
 524                                                 *al = SSL_AD_DECODE_ERROR;
 525                                                 return 0;
 526                                                 }
 527                                         sdata = data;
 528                                         data += idsize;
 529                                         id = d2i_OCSP_RESPID(NULL,
 530                                                                 &sdata, idsize);
 531                                         if (!id)
 532                                                 {
 533                                                 *al = SSL_AD_DECODE_ERROR;
 534                                                 return 0;
 535                                                 }
 536                                         if (data != sdata)
 537                                                 {
 538                                                 OCSP_RESPID_free(id);
 539                                                 *al = SSL_AD_DECODE_ERROR;
 540                                                 return 0;
 541                                                 }
 542                                         if (!s->tlsext_ocsp_ids
 543                                                 && !(s->tlsext_ocsp_ids =
 544                                                 sk_OCSP_RESPID_new_null()))
 545                                                 {
 546                                                 OCSP_RESPID_free(id);
 547                                                 *al = SSL_AD_INTERNAL_ERROR;
 548                                                 return 0;
 549                                                 }
 550                                         if (!sk_OCSP_RESPID_push(
 551                                                         s->tlsext_ocsp_ids, id))
 552                                                 {
 553                                                 OCSP_RESPID_free(id);
 554                                                 *al = SSL_AD_INTERNAL_ERROR;
 555                                                 return 0;
 556                                                 }
 557                                         }
 558
 559                                 /* Read in request_extensions */
 560                                 n2s(data,dsize);
 561                                 size -= 2;
 562                                 if (dsize > size)
 563                                         {
 564                                         *al = SSL_AD_DECODE_ERROR;
 565                                         return 0;
 566                                         }
 567                                 sdata = data;
 568                                 if (dsize > 0)
 569                                         {
 570                                         s->tlsext_ocsp_exts =
 571                                                 d2i_X509_EXTENSIONS(NULL,
 572                                                         &sdata, dsize);
 573                                         if (!s->tlsext_ocsp_exts
 574                                                 || (data + dsize != sdata))
 575                                                 {
 576                                                 *al = SSL_AD_DECODE_ERROR;
 577                                                 return 0;
 578                                                 }
 579                                         }
 580                                 }
 581                                 /* We don't know what to do with any other type
 582                                 * so ignore it.
 583                                 */
 584                                 else
 585                                         s->tlsext_status_type = -1;
 586                         }
 587
 588                 /* session ticket processed earlier */
 589
 590                 data+=size;
 591                 }
 592
 593         if (s->new_session && !renegotiate_seen
 594                 && !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
 595                 {
 596                 *al = SSL_AD_ILLEGAL_PARAMETER; /* is this the right alert? */
 597                 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
 598                 return 0;
 599                 }
 600
 601         *p = data;
 602         return 1;
 603         }
 604
 605 int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
 606         {
 607         unsigned short type;
 608         unsigned short size;
 609         unsigned short len;
 610         unsigned char *data = *p;
 611         int tlsext_servername = 0;
 612         int renegotiate_seen = 0;
 613
 614         if (data >= (d+n-2))
 615                 {
 616                 /* Because the client does not see any renegotiation during an
 617                    attack, we must enforce this on all server hellos, even the
 618                    first */
 619                 if (!(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
 620                         {
 621                         /* We should always see one extension: the renegotiate extension */
 622                         *al = SSL_AD_ILLEGAL_PARAMETER; /* is this the right alert? */
 623                         SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
 624                         return 0;
 625                         }
 626                 return 1;
 627                 }
 628
 629         n2s(data,len);
 630
 631         while(data <= (d+n-4))
 632                 {
 633                 n2s(data,type);
 634                 n2s(data,size);
 635
 636                 if (data+size > (d+n))
 637                         return 1;
 638
 639                 if (s->tlsext_debug_cb)
 640                         s->tlsext_debug_cb(s, 1, type, data, size,
 641                                                 s->tlsext_debug_arg);
 642
 643                 if (type == TLSEXT_TYPE_server_name)
 644                         {
 645                         if (s->tlsext_hostname == NULL || size > 0)
 646                                 {
 647                                 *al = TLS1_AD_UNRECOGNIZED_NAME;
 648                                 return 0;
 649                                 }
 650                         tlsext_servername = 1;
 651                         }
 652                 else if (type == TLSEXT_TYPE_session_ticket)
 653                         {
 654                         if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
 655                                 || (size > 0))
 656                                 {
 657                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
 658                                 return 0;
 659                                 }
 660                         s->tlsext_ticket_expected = 1;
 661                         }
 662                 else if (type == TLSEXT_TYPE_status_request &&
 663                          s->version != DTLS1_VERSION)
 664                         {
 665                         /* MUST be empty and only sent if we've requested
 666                          * a status request message.
 667                          */
 668                         if ((s->tlsext_status_type == -1) || (size > 0))
 669                                 {
 670                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
 671                                 return 0;
 672                                 }
 673                         /* Set flag to expect CertificateStatus message */
 674                         s->tlsext_status_expected = 1;
 675                         }
 676                 else if (type == TLSEXT_TYPE_renegotiate)
 677                         {
 678                         if(!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
 679                                 return 0;
 680                         renegotiate_seen = 1;
 681                         }
 682                 data+=size;
 683                 }
 684
 685         if (data != d+n)
 686                 {
 687                 *al = SSL_AD_DECODE_ERROR;
 688                 return 0;
 689                 }
 690
 691         if (!renegotiate_seen
 692                 && !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
 693                 {
 694                 *al = SSL_AD_ILLEGAL_PARAMETER; /* is this the right alert? */
 695                 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
 696                 return 0;
 697                 }
 698
 699         if (!s->hit && tlsext_servername == 1)
 700                 {
 701                 if (s->tlsext_hostname)
 702                         {
 703                         if (s->session->tlsext_hostname == NULL)
 704                                 {
 705                                 s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);
 706                                 if (!s->session->tlsext_hostname)
 707                                         {
 708                                         *al = SSL_AD_UNRECOGNIZED_NAME;
 709                                         return 0;
 710                                         }
 711                                 }
 712                         else
 713                                 {
 714                                 *al = SSL_AD_DECODE_ERROR;
 715                                 return 0;
 716                                 }
 717                         }
 718                 }
 719
 720         *p = data;
 721         return 1;
 722         }
 723
 724 int ssl_check_clienthello_tlsext(SSL *s)
 725         {
 726         int ret=SSL_TLSEXT_ERR_NOACK;
 727         int al = SSL_AD_UNRECOGNIZED_NAME;
 728
 729         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
 730                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
 731         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
 732                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
 733
 734         /* If status request then ask callback what to do.
 735          * Note: this must be called after servername callbacks in case
 736          * the certificate has changed.
 737          */
 738         if ((s->tlsext_status_type != -1) && s->ctx->tlsext_status_cb)
 739                 {
 740                 int r;
 741                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
 742                 switch (r)
 743                         {
 744                         /* We don't want to send a status request response */
 745                         case SSL_TLSEXT_ERR_NOACK:
 746                                 s->tlsext_status_expected = 0;
 747                                 break;
 748                         /* status request response should be sent */
 749                         case SSL_TLSEXT_ERR_OK:
 750                                 if (s->tlsext_ocsp_resp)
 751                                         s->tlsext_status_expected = 1;
 752                                 else
 753                                         s->tlsext_status_expected = 0;
 754                                 break;
 755                         /* something bad happened */
 756                         case SSL_TLSEXT_ERR_ALERT_FATAL:
 757                                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
 758                                 al = SSL_AD_INTERNAL_ERROR;
 759                                 goto err;
 760                         }
 761                 }
 762         else
 763                 s->tlsext_status_expected = 0;
 764         err:
 765         switch (ret)
 766                 {
 767                 case SSL_TLSEXT_ERR_ALERT_FATAL:
 768                         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 769                         return -1;
 770
 771                 case SSL_TLSEXT_ERR_ALERT_WARNING:
 772                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
 773                         return 1;
 774
 775                 case SSL_TLSEXT_ERR_NOACK:
 776                         s->servername_done=0;
 777                         default:
 778                 return 1;
 779                 }
 780         }
 781
 782 int ssl_check_serverhello_tlsext(SSL *s)
 783         {
 784         int ret=SSL_TLSEXT_ERR_NOACK;
 785         int al = SSL_AD_UNRECOGNIZED_NAME;
 786
 787         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
 788                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
 789         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
 790                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
 791
 792         /* If we've requested certificate status and we wont get one
 793          * tell the callback
 794          */
 795         if ((s->tlsext_status_type != -1) && !(s->tlsext_status_expected)
 796                         && s->ctx->tlsext_status_cb)
 797                 {
 798                 int r;
 799                 /* Set resp to NULL, resplen to -1 so callback knows
 800                  * there is no response.
 801                  */
 802                 if (s->tlsext_ocsp_resp)
 803                         {
 804                         OPENSSL_free(s->tlsext_ocsp_resp);
 805                         s->tlsext_ocsp_resp = NULL;
 806                         }
 807                 s->tlsext_ocsp_resplen = -1;
 808                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
 809                 if (r == 0)
 810                         {
 811                         al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
 812                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
 813                         }
 814                 if (r < 0)
 815                         {
 816                         al = SSL_AD_INTERNAL_ERROR;
 817                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
 818                         }
 819                 }
 820
 821         switch (ret)
 822                 {
 823                 case SSL_TLSEXT_ERR_ALERT_FATAL:
 824                         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 825                         return -1;
 826
 827                 case SSL_TLSEXT_ERR_ALERT_WARNING:
 828                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
 829                         return 1;
 830
 831                 case SSL_TLSEXT_ERR_NOACK:
 832                         s->servername_done=0;
 833                         default:
 834                 return 1;
 835                 }
 836         }
 837
 838 /* Since the server cache lookup is done early on in the processing of client
 839  * hello and other operations depend on the result we need to handle any TLS
 840  * session ticket extension at the same time.
 841  */
 842
 843 int tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
 844                                 const unsigned char *limit, SSL_SESSION **ret)
 845         {
 846         /* Point after session ID in client hello */
 847         const unsigned char *p = session_id + len;
 848         unsigned short i;
 849
 850         /* If tickets disabled behave as if no ticket present
 851          * to permit stateful resumption.
 852          */
 853         if (SSL_get_options(s) & SSL_OP_NO_TICKET)
 854                 return 1;
 855
 856         if ((s->version <= SSL3_VERSION) || !limit)
 857                 return 1;
 858         if (p >= limit)
 859                 return -1;
 860         /* Skip past DTLS cookie */
 861         if (s->version == DTLS1_VERSION || s->version == DTLS1_BAD_VER)
 862                 {
 863                 i = *(p++);
 864                 p+= i;
 865                 if (p >= limit)
 866                         return -1;
 867                 }
 868         /* Skip past cipher list */
 869         n2s(p, i);
 870         p+= i;
 871         if (p >= limit)
 872                 return -1;
 873         /* Skip past compression algorithm list */
 874         i = *(p++);
 875         p += i;
 876         if (p > limit)
 877                 return -1;
 878         /* Now at start of extensions */
 879         if ((p + 2) >= limit)
 880                 return 1;
 881         n2s(p, i);
 882         while ((p + 4) <= limit)
 883                 {
 884                 unsigned short type, size;
 885                 n2s(p, type);
 886                 n2s(p, size);
 887                 if (p + size > limit)
 888                         return 1;
 889                 if (type == TLSEXT_TYPE_session_ticket)
 890                         {
 891                         /* If zero length note client will accept a ticket
 892                          * and indicate cache miss to trigger full handshake
 893                          */
 894                         if (size == 0)
 895                                 {
 896                                 s->tlsext_ticket_expected = 1;
 897                                 return 0;       /* Cache miss */
 898                                 }
 899                         return tls_decrypt_ticket(s, p, size, session_id, len,
 900                                                                         ret);
 901                         }
 902                 p += size;
 903                 }
 904         return 1;
 905         }
 906
 907 static int tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen,
 908                                 const unsigned char *sess_id, int sesslen,
 909                                 SSL_SESSION **psess)
 910         {
 911         SSL_SESSION *sess;
 912         unsigned char *sdec;
 913         const unsigned char *p;
 914         int slen, mlen, renew_ticket = 0;
 915         unsigned char tick_hmac[EVP_MAX_MD_SIZE];
 916         HMAC_CTX hctx;
 917         EVP_CIPHER_CTX ctx;
 918         SSL_CTX *tctx = s->initial_ctx;
 919         /* Need at least keyname + iv + some encrypted data */
 920         if (eticklen < 48)
 921                 goto tickerr;
 922         /* Initialize session ticket encryption and HMAC contexts */
 923         HMAC_CTX_init(&hctx);
 924         EVP_CIPHER_CTX_init(&ctx);
 925         if (tctx->tlsext_ticket_key_cb)
 926                 {
 927                 unsigned char *nctick = (unsigned char *)etick;
 928                 int rv = tctx->tlsext_ticket_key_cb(s, nctick, nctick + 16,
 929                                                         &ctx, &hctx, 0);
 930                 if (rv < 0)
 931                         return -1;
 932                 if (rv == 0)
 933                         goto tickerr;
 934                 if (rv == 2)
 935                         renew_ticket = 1;
 936                 }
 937         else
 938                 {
 939                 /* Check key name matches */
 940                 if (memcmp(etick, tctx->tlsext_tick_key_name, 16))
 941                         goto tickerr;
 942                 HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,
 943                                         tlsext_tick_md(), NULL);
 944                 EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
 945                                 tctx->tlsext_tick_aes_key, etick + 16);
 946                 }
 947         /* Attempt to process session ticket, first conduct sanity and
 948          * integrity checks on ticket.
 949          */
 950         mlen = HMAC_size(&hctx);
 951         eticklen -= mlen;
 952         /* Check HMAC of encrypted ticket */
 953         HMAC_Update(&hctx, etick, eticklen);
 954         HMAC_Final(&hctx, tick_hmac, NULL);
 955         HMAC_CTX_cleanup(&hctx);
 956         if (memcmp(tick_hmac, etick + eticklen, mlen))
 957                 goto tickerr;
 958         /* Attempt to decrypt session data */
 959         /* Move p after IV to start of encrypted ticket, update length */
 960         p = etick + 16 + EVP_CIPHER_CTX_iv_length(&ctx);
 961         eticklen -= 16 + EVP_CIPHER_CTX_iv_length(&ctx);
 962         sdec = OPENSSL_malloc(eticklen);
 963         if (!sdec)
 964                 {
 965                 EVP_CIPHER_CTX_cleanup(&ctx);
 966                 return -1;
 967                 }
 968         EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen);
 969         if (EVP_DecryptFinal(&ctx, sdec + slen, &mlen) <= 0)
 970                 goto tickerr;
 971         slen += mlen;
 972         EVP_CIPHER_CTX_cleanup(&ctx);
 973         p = sdec;
 974
 975         sess = d2i_SSL_SESSION(NULL, &p, slen);
 976         OPENSSL_free(sdec);
 977         if (sess)
 978                 {
 979                 /* The session ID if non-empty is used by some clients to
 980                  * detect that the ticket has been accepted. So we copy it to
 981                  * the session structure. If it is empty set length to zero
 982                  * as required by standard.
 983                  */
 984                 if (sesslen)
 985                         memcpy(sess->session_id, sess_id, sesslen);
 986                 sess->session_id_length = sesslen;
 987                 *psess = sess;
 988                 s->tlsext_ticket_expected = renew_ticket;
 989                 return 1;
 990                 }
 991         /* If session decrypt failure indicate a cache miss and set state to
 992          * send a new ticket
 993          */
 994         tickerr:
 995         s->tlsext_ticket_expected = 1;
 996         return 0;
 997         }
 998
 999 #endif