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  * Copyright (c) 1998-2007 The OpenSSL Project.  All rights reserved.
  60  *
  61  * Redistribution and use in source and binary forms, with or without
  62  * modification, are permitted provided that the following conditions
  63  * are met:
  64  *
  65  * 1. Redistributions of source code must retain the above copyright
  66  *    notice, this list of conditions and the following disclaimer.
  67  *
  68  * 2. Redistributions in binary form must reproduce the above copyright
  69  *    notice, this list of conditions and the following disclaimer in
  70  *    the documentation and/or other materials provided with the
  71  *    distribution.
  72  *
  73  * 3. All advertising materials mentioning features or use of this
  74  *    software must display the following acknowledgment:
  75  *    "This product includes software developed by the OpenSSL Project
  76  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  77  *
  78  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  79  *    endorse or promote products derived from this software without
  80  *    prior written permission. For written permission, please contact
  81  *    openssl-core@openssl.org.
  82  *
  83  * 5. Products derived from this software may not be called "OpenSSL"
  84  *    nor may "OpenSSL" appear in their names without prior written
  85  *    permission of the OpenSSL Project.
  86  *
  87  * 6. Redistributions of any form whatsoever must retain the following
  88  *    acknowledgment:
  89  *    "This product includes software developed by the OpenSSL Project
  90  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  91  *
  92  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  93  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  94  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  95  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  96  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  97  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  98  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  99  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 100  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 101  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 102  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 103  * OF THE POSSIBILITY OF SUCH DAMAGE.
 104  * ====================================================================
 105  *
 106  * This product includes cryptographic software written by Eric Young
 107  * (eay@cryptsoft.com).  This product includes software written by Tim
 108  * Hudson (tjh@cryptsoft.com).
 109  *
 110  */
 111
 112 #include <stdio.h>
 113 #include <openssl/objects.h>
 114 #include <openssl/evp.h>
 115 #include <openssl/hmac.h>
 116 #include <openssl/ocsp.h>
 117 #include <openssl/rand.h>
 118 #include "ssl_locl.h"
 119
 120 const char tls1_version_str[]="TLSv1" OPENSSL_VERSION_PTEXT;
 121
 122 #ifndef OPENSSL_NO_TLSEXT
 123 static int tls_decrypt_ticket(SSL *s, const unsigned char *tick, int ticklen,
 124                                 const unsigned char *sess_id, int sesslen,
 125                                 SSL_SESSION **psess);
 126 #endif
 127
 128 SSL3_ENC_METHOD TLSv1_enc_data={
 129         tls1_enc,
 130         tls1_mac,
 131         tls1_setup_key_block,
 132         tls1_generate_master_secret,
 133         tls1_change_cipher_state,
 134         tls1_final_finish_mac,
 135         TLS1_FINISH_MAC_LENGTH,
 136         tls1_cert_verify_mac,
 137         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
 138         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
 139         tls1_alert_code,
 140         tls1_export_keying_material,
 141         };
 142
 143 long tls1_default_timeout(void)
 144         {
 145         /* 2 hours, the 24 hours mentioned in the TLSv1 spec
 146          * is way too long for http, the cache would over fill */
 147         return(60*60*2);
 148         }
 149
 150 int tls1_new(SSL *s)
 151         {
 152         if (!ssl3_new(s)) return(0);
 153         s->method->ssl_clear(s);
 154         return(1);
 155         }
 156
 157 void tls1_free(SSL *s)
 158         {
 159 #ifndef OPENSSL_NO_TLSEXT
 160         if (s->tlsext_session_ticket)
 161                 {
 162                 OPENSSL_free(s->tlsext_session_ticket);
 163                 }
 164 #endif /* OPENSSL_NO_TLSEXT */
 165         ssl3_free(s);
 166         }
 167
 168 void tls1_clear(SSL *s)
 169         {
 170         ssl3_clear(s);
 171         s->version = s->method->version;
 172         }
 173
 174 #ifndef OPENSSL_NO_EC
 175
 176 static int nid_list[] =
 177         {
 178                 NID_sect163k1, /* sect163k1 (1) */
 179                 NID_sect163r1, /* sect163r1 (2) */
 180                 NID_sect163r2, /* sect163r2 (3) */
 181                 NID_sect193r1, /* sect193r1 (4) */
 182                 NID_sect193r2, /* sect193r2 (5) */
 183                 NID_sect233k1, /* sect233k1 (6) */
 184                 NID_sect233r1, /* sect233r1 (7) */
 185                 NID_sect239k1, /* sect239k1 (8) */
 186                 NID_sect283k1, /* sect283k1 (9) */
 187                 NID_sect283r1, /* sect283r1 (10) */
 188                 NID_sect409k1, /* sect409k1 (11) */
 189                 NID_sect409r1, /* sect409r1 (12) */
 190                 NID_sect571k1, /* sect571k1 (13) */
 191                 NID_sect571r1, /* sect571r1 (14) */
 192                 NID_secp160k1, /* secp160k1 (15) */
 193                 NID_secp160r1, /* secp160r1 (16) */
 194                 NID_secp160r2, /* secp160r2 (17) */
 195                 NID_secp192k1, /* secp192k1 (18) */
 196                 NID_X9_62_prime192v1, /* secp192r1 (19) */
 197                 NID_secp224k1, /* secp224k1 (20) */
 198                 NID_secp224r1, /* secp224r1 (21) */
 199                 NID_secp256k1, /* secp256k1 (22) */
 200                 NID_X9_62_prime256v1, /* secp256r1 (23) */
 201                 NID_secp384r1, /* secp384r1 (24) */
 202                 NID_secp521r1  /* secp521r1 (25) */
 203         };
 204
 205 static int pref_list[] =
 206         {
 207 #ifndef OPENSSL_NO_EC2M
 208                 NID_sect571r1, /* sect571r1 (14) */
 209                 NID_sect571k1, /* sect571k1 (13) */
 210 #endif
 211                 NID_secp521r1, /* secp521r1 (25) */
 212 #ifndef OPENSSL_NO_EC2M
 213                 NID_sect409k1, /* sect409k1 (11) */
 214                 NID_sect409r1, /* sect409r1 (12) */
 215 #endif
 216                 NID_secp384r1, /* secp384r1 (24) */
 217 #ifndef OPENSSL_NO_EC2M
 218                 NID_sect283k1, /* sect283k1 (9) */
 219                 NID_sect283r1, /* sect283r1 (10) */
 220 #endif
 221                 NID_secp256k1, /* secp256k1 (22) */
 222                 NID_X9_62_prime256v1, /* secp256r1 (23) */
 223 #ifndef OPENSSL_NO_EC2M
 224                 NID_sect239k1, /* sect239k1 (8) */
 225                 NID_sect233k1, /* sect233k1 (6) */
 226                 NID_sect233r1, /* sect233r1 (7) */
 227 #endif
 228                 NID_secp224k1, /* secp224k1 (20) */
 229                 NID_secp224r1, /* secp224r1 (21) */
 230 #ifndef OPENSSL_NO_EC2M
 231                 NID_sect193r1, /* sect193r1 (4) */
 232                 NID_sect193r2, /* sect193r2 (5) */
 233 #endif
 234                 NID_secp192k1, /* secp192k1 (18) */
 235                 NID_X9_62_prime192v1, /* secp192r1 (19) */
 236 #ifndef OPENSSL_NO_EC2M
 237                 NID_sect163k1, /* sect163k1 (1) */
 238                 NID_sect163r1, /* sect163r1 (2) */
 239                 NID_sect163r2, /* sect163r2 (3) */
 240 #endif
 241                 NID_secp160k1, /* secp160k1 (15) */
 242                 NID_secp160r1, /* secp160r1 (16) */
 243                 NID_secp160r2, /* secp160r2 (17) */
 244         };
 245
 246 int tls1_ec_curve_id2nid(int curve_id)
 247         {
 248         /* ECC curves from RFC 4492 */
 249         if ((curve_id < 1) || ((unsigned int)curve_id >
 250                                 sizeof(nid_list)/sizeof(nid_list[0])))
 251                 return 0;
 252         return nid_list[curve_id-1];
 253         }
 254
 255 int tls1_ec_nid2curve_id(int nid)
 256         {
 257         /* ECC curves from RFC 4492 */
 258         switch (nid)
 259                 {
 260         case NID_sect163k1: /* sect163k1 (1) */
 261                 return 1;
 262         case NID_sect163r1: /* sect163r1 (2) */
 263                 return 2;
 264         case NID_sect163r2: /* sect163r2 (3) */
 265                 return 3;
 266         case NID_sect193r1: /* sect193r1 (4) */
 267                 return 4;
 268         case NID_sect193r2: /* sect193r2 (5) */
 269                 return 5;
 270         case NID_sect233k1: /* sect233k1 (6) */
 271                 return 6;
 272         case NID_sect233r1: /* sect233r1 (7) */
 273                 return 7;
 274         case NID_sect239k1: /* sect239k1 (8) */
 275                 return 8;
 276         case NID_sect283k1: /* sect283k1 (9) */
 277                 return 9;
 278         case NID_sect283r1: /* sect283r1 (10) */
 279                 return 10;
 280         case NID_sect409k1: /* sect409k1 (11) */
 281                 return 11;
 282         case NID_sect409r1: /* sect409r1 (12) */
 283                 return 12;
 284         case NID_sect571k1: /* sect571k1 (13) */
 285                 return 13;
 286         case NID_sect571r1: /* sect571r1 (14) */
 287                 return 14;
 288         case NID_secp160k1: /* secp160k1 (15) */
 289                 return 15;
 290         case NID_secp160r1: /* secp160r1 (16) */
 291                 return 16;
 292         case NID_secp160r2: /* secp160r2 (17) */
 293                 return 17;
 294         case NID_secp192k1: /* secp192k1 (18) */
 295                 return 18;
 296         case NID_X9_62_prime192v1: /* secp192r1 (19) */
 297                 return 19;
 298         case NID_secp224k1: /* secp224k1 (20) */
 299                 return 20;
 300         case NID_secp224r1: /* secp224r1 (21) */
 301                 return 21;
 302         case NID_secp256k1: /* secp256k1 (22) */
 303                 return 22;
 304         case NID_X9_62_prime256v1: /* secp256r1 (23) */
 305                 return 23;
 306         case NID_secp384r1: /* secp384r1 (24) */
 307                 return 24;
 308         case NID_secp521r1:  /* secp521r1 (25) */
 309                 return 25;
 310         default:
 311                 return 0;
 312                 }
 313         }
 314 #endif /* OPENSSL_NO_EC */
 315
 316 #ifndef OPENSSL_NO_TLSEXT
 317
 318 /* List of supported signature algorithms and hashes. Should make this
 319  * customisable at some point, for now include everything we support.
 320  */
 321
 322 #ifdef OPENSSL_NO_RSA
 323 #define tlsext_sigalg_rsa(md) /* */
 324 #else
 325 #define tlsext_sigalg_rsa(md) md, TLSEXT_signature_rsa,
 326 #endif
 327
 328 #ifdef OPENSSL_NO_DSA
 329 #define tlsext_sigalg_dsa(md) /* */
 330 #else
 331 #define tlsext_sigalg_dsa(md) md, TLSEXT_signature_dsa,
 332 #endif
 333
 334 #ifdef OPENSSL_NO_ECDSA
 335 #define tlsext_sigalg_ecdsa(md) /* */
 336 #else
 337 #define tlsext_sigalg_ecdsa(md) md, TLSEXT_signature_ecdsa,
 338 #endif
 339
 340 #define tlsext_sigalg(md) \
 341                 tlsext_sigalg_rsa(md) \
 342                 tlsext_sigalg_dsa(md) \
 343                 tlsext_sigalg_ecdsa(md)
 344
 345 static unsigned char tls12_sigalgs[] = {
 346 #ifndef OPENSSL_NO_SHA512
 347         tlsext_sigalg(TLSEXT_hash_sha512)
 348         tlsext_sigalg(TLSEXT_hash_sha384)
 349 #endif
 350 #ifndef OPENSSL_NO_SHA256
 351         tlsext_sigalg(TLSEXT_hash_sha256)
 352         tlsext_sigalg(TLSEXT_hash_sha224)
 353 #endif
 354 #ifndef OPENSSL_NO_SHA
 355         tlsext_sigalg(TLSEXT_hash_sha1)
 356 #endif
 357 };
 358
 359 int tls12_get_req_sig_algs(SSL *s, unsigned char *p)
 360         {
 361         size_t slen = sizeof(tls12_sigalgs);
 362         if (p)
 363                 memcpy(p, tls12_sigalgs, slen);
 364         return (int)slen;
 365         }
 366
 367 unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit)
 368         {
 369         int extdatalen=0;
 370         unsigned char *orig = buf;
 371         unsigned char *ret = buf;
 372
 373         /* don't add extensions for SSLv3 unless doing secure renegotiation */
 374         if (s->client_version == SSL3_VERSION
 375                                         && !s->s3->send_connection_binding)
 376                 return orig;
 377
 378         ret+=2;
 379
 380         if (ret>=limit) return NULL; /* this really never occurs, but ... */
 381
 382         if (s->tlsext_hostname != NULL)
 383                 {
 384                 /* Add TLS extension servername to the Client Hello message */
 385                 unsigned long size_str;
 386                 long lenmax;
 387
 388                 /* check for enough space.
 389                    4 for the servername type and entension length
 390                    2 for servernamelist length
 391                    1 for the hostname type
 392                    2 for hostname length
 393                    + hostname length
 394                 */
 395
 396                 if ((lenmax = limit - ret - 9) < 0
 397                     || (size_str = strlen(s->tlsext_hostname)) > (unsigned long)lenmax)
 398                         return NULL;
 399
 400                 /* extension type and length */
 401                 s2n(TLSEXT_TYPE_server_name,ret);
 402                 s2n(size_str+5,ret);
 403
 404                 /* length of servername list */
 405                 s2n(size_str+3,ret);
 406
 407                 /* hostname type, length and hostname */
 408                 *(ret++) = (unsigned char) TLSEXT_NAMETYPE_host_name;
 409                 s2n(size_str,ret);
 410                 memcpy(ret, s->tlsext_hostname, size_str);
 411                 ret+=size_str;
 412                 }
 413
 414         /* Add RI if renegotiating */
 415         if (s->renegotiate)
 416           {
 417           int el;
 418
 419           if(!ssl_add_clienthello_renegotiate_ext(s, 0, &el, 0))
 420               {
 421               SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 422               return NULL;
 423               }
 424
 425           if((limit - ret - 4 - el) < 0) return NULL;
 426
 427           s2n(TLSEXT_TYPE_renegotiate,ret);
 428           s2n(el,ret);
 429
 430           if(!ssl_add_clienthello_renegotiate_ext(s, ret, &el, el))
 431               {
 432               SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 433               return NULL;
 434               }
 435
 436           ret += el;
 437         }
 438
 439 #ifndef OPENSSL_NO_SRP
 440         /* Add SRP username if there is one */
 441         if (s->srp_ctx.login != NULL)
 442                 { /* Add TLS extension SRP username to the Client Hello message */
 443
 444                 int login_len = strlen(s->srp_ctx.login);
 445                 if (login_len > 255 || login_len == 0)
 446                         {
 447                         SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 448                         return NULL;
 449                         }
 450
 451                 /* check for enough space.
 452                    4 for the srp type type and entension length
 453                    1 for the srp user identity
 454                    + srp user identity length
 455                 */
 456                 if ((limit - ret - 5 - login_len) < 0) return NULL;
 457
 458                 /* fill in the extension */
 459                 s2n(TLSEXT_TYPE_srp,ret);
 460                 s2n(login_len+1,ret);
 461                 (*ret++) = (unsigned char) login_len;
 462                 memcpy(ret, s->srp_ctx.login, login_len);
 463                 ret+=login_len;
 464                 }
 465 #endif
 466
 467 #ifndef OPENSSL_NO_EC
 468         if (s->tlsext_ecpointformatlist != NULL)
 469                 {
 470                 /* Add TLS extension ECPointFormats to the ClientHello message */
 471                 long lenmax;
 472
 473                 if ((lenmax = limit - ret - 5) < 0) return NULL;
 474                 if (s->tlsext_ecpointformatlist_length > (unsigned long)lenmax) return NULL;
 475                 if (s->tlsext_ecpointformatlist_length > 255)
 476                         {
 477                         SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 478                         return NULL;
 479                         }
 480
 481                 s2n(TLSEXT_TYPE_ec_point_formats,ret);
 482                 s2n(s->tlsext_ecpointformatlist_length + 1,ret);
 483                 *(ret++) = (unsigned char) s->tlsext_ecpointformatlist_length;
 484                 memcpy(ret, s->tlsext_ecpointformatlist, s->tlsext_ecpointformatlist_length);
 485                 ret+=s->tlsext_ecpointformatlist_length;
 486                 }
 487         if (s->tlsext_ellipticcurvelist != NULL)
 488                 {
 489                 /* Add TLS extension EllipticCurves to the ClientHello message */
 490                 long lenmax;
 491
 492                 if ((lenmax = limit - ret - 6) < 0) return NULL;
 493                 if (s->tlsext_ellipticcurvelist_length > (unsigned long)lenmax) return NULL;
 494                 if (s->tlsext_ellipticcurvelist_length > 65532)
 495                         {
 496                         SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 497                         return NULL;
 498                         }
 499
 500                 s2n(TLSEXT_TYPE_elliptic_curves,ret);
 501                 s2n(s->tlsext_ellipticcurvelist_length + 2, ret);
 502
 503                 s2n(s->tlsext_ellipticcurvelist_length, ret);
 504                 memcpy(ret, s->tlsext_ellipticcurvelist, s->tlsext_ellipticcurvelist_length);
 505                 ret+=s->tlsext_ellipticcurvelist_length;
 506                 }
 507 #endif /* OPENSSL_NO_EC */
 508
 509         if (!(SSL_get_options(s) & SSL_OP_NO_TICKET))
 510                 {
 511                 int ticklen;
 512                 if (!s->new_session && s->session && s->session->tlsext_tick)
 513                         ticklen = s->session->tlsext_ticklen;
 514                 else if (s->session && s->tlsext_session_ticket &&
 515                          s->tlsext_session_ticket->data)
 516                         {
 517                         ticklen = s->tlsext_session_ticket->length;
 518                         s->session->tlsext_tick = OPENSSL_malloc(ticklen);
 519                         if (!s->session->tlsext_tick)
 520                                 return NULL;
 521                         memcpy(s->session->tlsext_tick,
 522                                s->tlsext_session_ticket->data,
 523                                ticklen);
 524                         s->session->tlsext_ticklen = ticklen;
 525                         }
 526                 else
 527                         ticklen = 0;
 528                 if (ticklen == 0 && s->tlsext_session_ticket &&
 529                     s->tlsext_session_ticket->data == NULL)
 530                         goto skip_ext;
 531                 /* Check for enough room 2 for extension type, 2 for len
 532                  * rest for ticket
 533                  */
 534                 if ((long)(limit - ret - 4 - ticklen) < 0) return NULL;
 535                 s2n(TLSEXT_TYPE_session_ticket,ret);
 536                 s2n(ticklen,ret);
 537                 if (ticklen)
 538                         {
 539                         memcpy(ret, s->session->tlsext_tick, ticklen);
 540                         ret += ticklen;
 541                         }
 542                 }
 543                 skip_ext:
 544
 545         if (TLS1_get_client_version(s) >= TLS1_2_VERSION)
 546                 {
 547                 if ((size_t)(limit - ret) < sizeof(tls12_sigalgs) + 6)
 548                         return NULL;
 549                 s2n(TLSEXT_TYPE_signature_algorithms,ret);
 550                 s2n(sizeof(tls12_sigalgs) + 2, ret);
 551                 s2n(sizeof(tls12_sigalgs), ret);
 552                 memcpy(ret, tls12_sigalgs, sizeof(tls12_sigalgs));
 553                 ret += sizeof(tls12_sigalgs);
 554                 }
 555
 556 #ifdef TLSEXT_TYPE_opaque_prf_input
 557         if (s->s3->client_opaque_prf_input != NULL &&
 558             s->version != DTLS1_VERSION)
 559                 {
 560                 size_t col = s->s3->client_opaque_prf_input_len;
 561
 562                 if ((long)(limit - ret - 6 - col < 0))
 563                         return NULL;
 564                 if (col > 0xFFFD) /* can't happen */
 565                         return NULL;
 566
 567                 s2n(TLSEXT_TYPE_opaque_prf_input, ret);
 568                 s2n(col + 2, ret);
 569                 s2n(col, ret);
 570                 memcpy(ret, s->s3->client_opaque_prf_input, col);
 571                 ret += col;
 572                 }
 573 #endif
 574
 575         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp &&
 576             s->version != DTLS1_VERSION)
 577                 {
 578                 int i;
 579                 long extlen, idlen, itmp;
 580                 OCSP_RESPID *id;
 581
 582                 idlen = 0;
 583                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
 584                         {
 585                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
 586                         itmp = i2d_OCSP_RESPID(id, NULL);
 587                         if (itmp <= 0)
 588                                 return NULL;
 589                         idlen += itmp + 2;
 590                         }
 591
 592                 if (s->tlsext_ocsp_exts)
 593                         {
 594                         extlen = i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, NULL);
 595                         if (extlen < 0)
 596                                 return NULL;
 597                         }
 598                 else
 599                         extlen = 0;
 600
 601                 if ((long)(limit - ret - 7 - extlen - idlen) < 0) return NULL;
 602                 s2n(TLSEXT_TYPE_status_request, ret);
 603                 if (extlen + idlen > 0xFFF0)
 604                         return NULL;
 605                 s2n(extlen + idlen + 5, ret);
 606                 *(ret++) = TLSEXT_STATUSTYPE_ocsp;
 607                 s2n(idlen, ret);
 608                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
 609                         {
 610                         /* save position of id len */
 611                         unsigned char *q = ret;
 612                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
 613                         /* skip over id len */
 614                         ret += 2;
 615                         itmp = i2d_OCSP_RESPID(id, &ret);
 616                         /* write id len */
 617                         s2n(itmp, q);
 618                         }
 619                 s2n(extlen, ret);
 620                 if (extlen > 0)
 621                         i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
 622                 }
 623
 624 #ifndef OPENSSL_NO_HEARTBEATS
 625         /* Add Heartbeat extension */
 626         if ((limit - ret - 4 - 1) < 0)
 627                 return NULL;
 628         s2n(TLSEXT_TYPE_heartbeat,ret);
 629         s2n(1,ret);
 630         /* Set mode:
 631          * 1: peer may send requests
 632          * 2: peer not allowed to send requests
 633          */
 634         if (s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_RECV_REQUESTS)
 635                 *(ret++) = SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
 636         else
 637                 *(ret++) = SSL_TLSEXT_HB_ENABLED;
 638 #endif
 639
 640 #ifndef OPENSSL_NO_NEXTPROTONEG
 641         if (s->ctx->next_proto_select_cb && !s->s3->tmp.finish_md_len)
 642                 {
 643                 /* The client advertises an emtpy extension to indicate its
 644                  * support for Next Protocol Negotiation */
 645                 if (limit - ret - 4 < 0)
 646                         return NULL;
 647                 s2n(TLSEXT_TYPE_next_proto_neg,ret);
 648                 s2n(0,ret);
 649                 }
 650 #endif
 651
 652 #ifndef OPENSSL_NO_SRTP
 653         if(SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s))
 654                 {
 655                 int el;
 656
 657                 ssl_add_clienthello_use_srtp_ext(s, 0, &el, 0);
 658
 659                 if((limit - ret - 4 - el) < 0) return NULL;
 660
 661                 s2n(TLSEXT_TYPE_use_srtp,ret);
 662                 s2n(el,ret);
 663
 664                 if(ssl_add_clienthello_use_srtp_ext(s, ret, &el, el))
 665                         {
 666                         SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 667                         return NULL;
 668                         }
 669                 ret += el;
 670                 }
 671 #endif
 672         /* Add padding to workaround bugs in F5 terminators.
 673          * See https://tools.ietf.org/html/draft-agl-tls-padding-03
 674          *
 675          * NB: because this code works out the length of all existing
 676          * extensions it MUST always appear last.
 677          */
 678         if (s->options & SSL_OP_TLSEXT_PADDING)
 679                 {
 680                 int hlen = ret - (unsigned char *)s->init_buf->data;
 681                 /* The code in s23_clnt.c to build ClientHello messages
 682                  * includes the 5-byte record header in the buffer, while
 683                  * the code in s3_clnt.c does not.
 684                  */
 685                 if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
 686                         hlen -= 5;
 687                 if (hlen > 0xff && hlen < 0x200)
 688                         {
 689                         hlen = 0x200 - hlen;
 690                         if (hlen >= 4)
 691                                 hlen -= 4;
 692                         else
 693                                 hlen = 0;
 694
 695                         s2n(TLSEXT_TYPE_padding, ret);
 696                         s2n(hlen, ret);
 697                         memset(ret, 0, hlen);
 698                         ret += hlen;
 699                         }
 700                 }
 701
 702         if ((extdatalen = ret-orig-2)== 0)
 703                 return orig;
 704
 705         s2n(extdatalen, orig);
 706         return ret;
 707         }
 708
 709 unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit)
 710         {
 711         int extdatalen=0;
 712         unsigned char *orig = buf;
 713         unsigned char *ret = buf;
 714 #ifndef OPENSSL_NO_NEXTPROTONEG
 715         int next_proto_neg_seen;
 716 #endif
 717
 718         /* don't add extensions for SSLv3, unless doing secure renegotiation */
 719         if (s->version == SSL3_VERSION && !s->s3->send_connection_binding)
 720                 return orig;
 721
 722         ret+=2;
 723         if (ret>=limit) return NULL; /* this really never occurs, but ... */
 724
 725         if (!s->hit && s->servername_done == 1 && s->session->tlsext_hostname != NULL)
 726                 {
 727                 if ((long)(limit - ret - 4) < 0) return NULL;
 728
 729                 s2n(TLSEXT_TYPE_server_name,ret);
 730                 s2n(0,ret);
 731                 }
 732
 733         if(s->s3->send_connection_binding)
 734         {
 735           int el;
 736
 737           if(!ssl_add_serverhello_renegotiate_ext(s, 0, &el, 0))
 738               {
 739               SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 740               return NULL;
 741               }
 742
 743           if((limit - ret - 4 - el) < 0) return NULL;
 744
 745           s2n(TLSEXT_TYPE_renegotiate,ret);
 746           s2n(el,ret);
 747
 748           if(!ssl_add_serverhello_renegotiate_ext(s, ret, &el, el))
 749               {
 750               SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 751               return NULL;
 752               }
 753
 754           ret += el;
 755         }
 756
 757 #ifndef OPENSSL_NO_EC
 758         if (s->tlsext_ecpointformatlist != NULL)
 759                 {
 760                 /* Add TLS extension ECPointFormats to the ServerHello message */
 761                 long lenmax;
 762
 763                 if ((lenmax = limit - ret - 5) < 0) return NULL;
 764                 if (s->tlsext_ecpointformatlist_length > (unsigned long)lenmax) return NULL;
 765                 if (s->tlsext_ecpointformatlist_length > 255)
 766                         {
 767                         SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 768                         return NULL;
 769                         }
 770
 771                 s2n(TLSEXT_TYPE_ec_point_formats,ret);
 772                 s2n(s->tlsext_ecpointformatlist_length + 1,ret);
 773                 *(ret++) = (unsigned char) s->tlsext_ecpointformatlist_length;
 774                 memcpy(ret, s->tlsext_ecpointformatlist, s->tlsext_ecpointformatlist_length);
 775                 ret+=s->tlsext_ecpointformatlist_length;
 776
 777                 }
 778         /* Currently the server should not respond with a SupportedCurves extension */
 779 #endif /* OPENSSL_NO_EC */
 780
 781         if (s->tlsext_ticket_expected
 782                 && !(SSL_get_options(s) & SSL_OP_NO_TICKET))
 783                 {
 784                 if ((long)(limit - ret - 4) < 0) return NULL;
 785                 s2n(TLSEXT_TYPE_session_ticket,ret);
 786                 s2n(0,ret);
 787                 }
 788
 789         if (s->tlsext_status_expected)
 790                 {
 791                 if ((long)(limit - ret - 4) < 0) return NULL;
 792                 s2n(TLSEXT_TYPE_status_request,ret);
 793                 s2n(0,ret);
 794                 }
 795
 796 #ifdef TLSEXT_TYPE_opaque_prf_input
 797         if (s->s3->server_opaque_prf_input != NULL &&
 798             s->version != DTLS1_VERSION)
 799                 {
 800                 size_t sol = s->s3->server_opaque_prf_input_len;
 801
 802                 if ((long)(limit - ret - 6 - sol) < 0)
 803                         return NULL;
 804                 if (sol > 0xFFFD) /* can't happen */
 805                         return NULL;
 806
 807                 s2n(TLSEXT_TYPE_opaque_prf_input, ret);
 808                 s2n(sol + 2, ret);
 809                 s2n(sol, ret);
 810                 memcpy(ret, s->s3->server_opaque_prf_input, sol);
 811                 ret += sol;
 812                 }
 813 #endif
 814
 815 #ifndef OPENSSL_NO_SRTP
 816         if(SSL_IS_DTLS(s) && s->srtp_profile)
 817                 {
 818                 int el;
 819
 820                 ssl_add_serverhello_use_srtp_ext(s, 0, &el, 0);
 821
 822                 if((limit - ret - 4 - el) < 0) return NULL;
 823
 824                 s2n(TLSEXT_TYPE_use_srtp,ret);
 825                 s2n(el,ret);
 826
 827                 if(ssl_add_serverhello_use_srtp_ext(s, ret, &el, el))
 828                         {
 829                         SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
 830                         return NULL;
 831                         }
 832                 ret+=el;
 833                 }
 834 #endif
 835
 836         if (((s->s3->tmp.new_cipher->id & 0xFFFF)==0x80 || (s->s3->tmp.new_cipher->id & 0xFFFF)==0x81)
 837                 && (SSL_get_options(s) & SSL_OP_CRYPTOPRO_TLSEXT_BUG))
 838                 { const unsigned char cryptopro_ext[36] = {
 839                         0xfd, 0xe8, /*65000*/
 840                         0x00, 0x20, /*32 bytes length*/
 841                         0x30, 0x1e, 0x30, 0x08, 0x06, 0x06, 0x2a, 0x85,
 842                         0x03,   0x02, 0x02, 0x09, 0x30, 0x08, 0x06, 0x06,
 843                         0x2a, 0x85, 0x03, 0x02, 0x02, 0x16, 0x30, 0x08,
 844                         0x06, 0x06, 0x2a, 0x85, 0x03, 0x02, 0x02, 0x17};
 845                         if (limit-ret<36) return NULL;
 846                         memcpy(ret,cryptopro_ext,36);
 847                         ret+=36;
 848
 849                 }
 850
 851 #ifndef OPENSSL_NO_HEARTBEATS
 852         /* Add Heartbeat extension if we've received one */
 853         if (s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED)
 854                 {
 855                 if ((limit - ret - 4 - 1) < 0)
 856                         return NULL;
 857                 s2n(TLSEXT_TYPE_heartbeat,ret);
 858                 s2n(1,ret);
 859                 /* Set mode:
 860                  * 1: peer may send requests
 861                  * 2: peer not allowed to send requests
 862                  */
 863                 if (s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_RECV_REQUESTS)
 864                         *(ret++) = SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
 865                 else
 866                         *(ret++) = SSL_TLSEXT_HB_ENABLED;
 867
 868                 }
 869 #endif
 870
 871 #ifndef OPENSSL_NO_NEXTPROTONEG
 872         next_proto_neg_seen = s->s3->next_proto_neg_seen;
 873         s->s3->next_proto_neg_seen = 0;
 874         if (next_proto_neg_seen && s->ctx->next_protos_advertised_cb)
 875                 {
 876                 const unsigned char *npa;
 877                 unsigned int npalen;
 878                 int r;
 879
 880                 r = s->ctx->next_protos_advertised_cb(s, &npa, &npalen, s->ctx->next_protos_advertised_cb_arg);
 881                 if (r == SSL_TLSEXT_ERR_OK)
 882                         {
 883                         if ((long)(limit - ret - 4 - npalen) < 0) return NULL;
 884                         s2n(TLSEXT_TYPE_next_proto_neg,ret);
 885                         s2n(npalen,ret);
 886                         memcpy(ret, npa, npalen);
 887                         ret += npalen;
 888                         s->s3->next_proto_neg_seen = 1;
 889                         }
 890                 }
 891 #endif
 892
 893         if ((extdatalen = ret-orig-2)== 0)
 894                 return orig;
 895
 896         s2n(extdatalen, orig);
 897         return ret;
 898         }
 899
 900 #ifndef OPENSSL_NO_EC
 901 /* ssl_check_for_safari attempts to fingerprint Safari using OS X
 902  * SecureTransport using the TLS extension block in |d|, of length |n|.
 903  * Safari, since 10.6, sends exactly these extensions, in this order:
 904  *   SNI,
 905  *   elliptic_curves
 906  *   ec_point_formats
 907  *
 908  * We wish to fingerprint Safari because they broke ECDHE-ECDSA support in 10.8,
 909  * but they advertise support. So enabling ECDHE-ECDSA ciphers breaks them.
 910  * Sadly we cannot differentiate 10.6, 10.7 and 10.8.4 (which work), from
 911  * 10.8..10.8.3 (which don't work).
 912  */
 913 static void ssl_check_for_safari(SSL *s, const unsigned char *data, const unsigned char *d, int n) {
 914         unsigned short type, size;
 915         static const unsigned char kSafariExtensionsBlock[] = {
 916                 0x00, 0x0a,  /* elliptic_curves extension */
 917                 0x00, 0x08,  /* 8 bytes */
 918                 0x00, 0x06,  /* 6 bytes of curve ids */
 919                 0x00, 0x17,  /* P-256 */
 920                 0x00, 0x18,  /* P-384 */
 921                 0x00, 0x19,  /* P-521 */
 922
 923                 0x00, 0x0b,  /* ec_point_formats */
 924                 0x00, 0x02,  /* 2 bytes */
 925                 0x01,        /* 1 point format */
 926                 0x00,        /* uncompressed */
 927         };
 928
 929         /* The following is only present in TLS 1.2 */
 930         static const unsigned char kSafariTLS12ExtensionsBlock[] = {
 931                 0x00, 0x0d,  /* signature_algorithms */
 932                 0x00, 0x0c,  /* 12 bytes */
 933                 0x00, 0x0a,  /* 10 bytes */
 934                 0x05, 0x01,  /* SHA-384/RSA */
 935                 0x04, 0x01,  /* SHA-256/RSA */
 936                 0x02, 0x01,  /* SHA-1/RSA */
 937                 0x04, 0x03,  /* SHA-256/ECDSA */
 938                 0x02, 0x03,  /* SHA-1/ECDSA */
 939         };
 940
 941         if (data >= (d+n-2))
 942                 return;
 943         data += 2;
 944
 945         if (data > (d+n-4))
 946                 return;
 947         n2s(data,type);
 948         n2s(data,size);
 949
 950         if (type != TLSEXT_TYPE_server_name)
 951                 return;
 952
 953         if (data+size > d+n)
 954                 return;
 955         data += size;
 956
 957         if (TLS1_get_client_version(s) >= TLS1_2_VERSION)
 958                 {
 959                 const size_t len1 = sizeof(kSafariExtensionsBlock);
 960                 const size_t len2 = sizeof(kSafariTLS12ExtensionsBlock);
 961
 962                 if (data + len1 + len2 != d+n)
 963                         return;
 964                 if (memcmp(data, kSafariExtensionsBlock, len1) != 0)
 965                         return;
 966                 if (memcmp(data + len1, kSafariTLS12ExtensionsBlock, len2) != 0)
 967                         return;
 968                 }
 969         else
 970                 {
 971                 const size_t len = sizeof(kSafariExtensionsBlock);
 972
 973                 if (data + len != d+n)
 974                         return;
 975                 if (memcmp(data, kSafariExtensionsBlock, len) != 0)
 976                         return;
 977                 }
 978
 979         s->s3->is_probably_safari = 1;
 980 }
 981 #endif /* !OPENSSL_NO_EC */
 982
 983 int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
 984         {
 985         unsigned short type;
 986         unsigned short size;
 987         unsigned short len;
 988         unsigned char *data = *p;
 989         int renegotiate_seen = 0;
 990         int sigalg_seen = 0;
 991
 992         s->servername_done = 0;
 993         s->tlsext_status_type = -1;
 994 #ifndef OPENSSL_NO_NEXTPROTONEG
 995         s->s3->next_proto_neg_seen = 0;
 996 #endif
 997
 998 #ifndef OPENSSL_NO_HEARTBEATS
 999         s->tlsext_heartbeat &= ~(SSL_TLSEXT_HB_ENABLED |
1000                                SSL_TLSEXT_HB_DONT_SEND_REQUESTS);
1001 #endif
1002
1003 #ifndef OPENSSL_NO_EC
1004         if (s->options & SSL_OP_SAFARI_ECDHE_ECDSA_BUG)
1005                 ssl_check_for_safari(s, data, d, n);
1006 #endif /* !OPENSSL_NO_EC */
1007
1008         if (data >= (d+n-2))
1009                 goto ri_check;
1010         n2s(data,len);
1011
1012         if (data > (d+n-len))
1013                 goto ri_check;
1014
1015         while (data <= (d+n-4))
1016                 {
1017                 n2s(data,type);
1018                 n2s(data,size);
1019
1020                 if (data+size > (d+n))
1021                         goto ri_check;
1022 #if 0
1023                 fprintf(stderr,"Received extension type %d size %d\n",type,size);
1024 #endif
1025                 if (s->tlsext_debug_cb)
1026                         s->tlsext_debug_cb(s, 0, type, data, size,
1027                                                 s->tlsext_debug_arg);
1028 /* The servername extension is treated as follows:
1029
1030    - Only the hostname type is supported with a maximum length of 255.
1031    - The servername is rejected if too long or if it contains zeros,
1032      in which case an fatal alert is generated.
1033    - The servername field is maintained together with the session cache.
1034    - When a session is resumed, the servername call back invoked in order
1035      to allow the application to position itself to the right context.
1036    - The servername is acknowledged if it is new for a session or when
1037      it is identical to a previously used for the same session.
1038      Applications can control the behaviour.  They can at any time
1039      set a 'desirable' servername for a new SSL object. This can be the
1040      case for example with HTTPS when a Host: header field is received and
1041      a renegotiation is requested. In this case, a possible servername
1042      presented in the new client hello is only acknowledged if it matches
1043      the value of the Host: field.
1044    - Applications must  use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
1045      if they provide for changing an explicit servername context for the session,
1046      i.e. when the session has been established with a servername extension.
1047    - On session reconnect, the servername extension may be absent.
1048
1049 */
1050
1051                 if (type == TLSEXT_TYPE_server_name)
1052                         {
1053                         unsigned char *sdata;
1054                         int servname_type;
1055                         int dsize;
1056
1057                         if (size < 2)
1058                                 {
1059                                 *al = SSL_AD_DECODE_ERROR;
1060                                 return 0;
1061                                 }
1062                         n2s(data,dsize);
1063                         size -= 2;
1064                         if (dsize > size  )
1065                                 {
1066                                 *al = SSL_AD_DECODE_ERROR;
1067                                 return 0;
1068                                 }
1069
1070                         sdata = data;
1071                         while (dsize > 3)
1072                                 {
1073                                 servname_type = *(sdata++);
1074                                 n2s(sdata,len);
1075                                 dsize -= 3;
1076
1077                                 if (len > dsize)
1078                                         {
1079                                         *al = SSL_AD_DECODE_ERROR;
1080                                         return 0;
1081                                         }
1082                                 if (s->servername_done == 0)
1083                                 switch (servname_type)
1084                                         {
1085                                 case TLSEXT_NAMETYPE_host_name:
1086                                         if (!s->hit)
1087                                                 {
1088                                                 if(s->session->tlsext_hostname)
1089                                                         {
1090                                                         *al = SSL_AD_DECODE_ERROR;
1091                                                         return 0;
1092                                                         }
1093                                                 if (len > TLSEXT_MAXLEN_host_name)
1094                                                         {
1095                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
1096                                                         return 0;
1097                                                         }
1098                                                 if ((s->session->tlsext_hostname = OPENSSL_malloc(len+1)) == NULL)
1099                                                         {
1100                                                         *al = TLS1_AD_INTERNAL_ERROR;
1101                                                         return 0;
1102                                                         }
1103                                                 memcpy(s->session->tlsext_hostname, sdata, len);
1104                                                 s->session->tlsext_hostname[len]='\0';
1105                                                 if (strlen(s->session->tlsext_hostname) != len) {
1106                                                         OPENSSL_free(s->session->tlsext_hostname);
1107                                                         s->session->tlsext_hostname = NULL;
1108                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
1109                                                         return 0;
1110                                                 }
1111                                                 s->servername_done = 1;
1112
1113                                                 }
1114                                         else
1115                                                 s->servername_done = s->session->tlsext_hostname
1116                                                         && strlen(s->session->tlsext_hostname) == len
1117                                                         && strncmp(s->session->tlsext_hostname, (char *)sdata, len) == 0;
1118
1119                                         break;
1120
1121                                 default:
1122                                         break;
1123                                         }
1124
1125                                 dsize -= len;
1126                                 }
1127                         if (dsize != 0)
1128                                 {
1129                                 *al = SSL_AD_DECODE_ERROR;
1130                                 return 0;
1131                                 }
1132
1133                         }
1134 #ifndef OPENSSL_NO_SRP
1135                 else if (type == TLSEXT_TYPE_srp)
1136                         {
1137                         if (size <= 0 || ((len = data[0])) != (size -1))
1138                                 {
1139                                 *al = SSL_AD_DECODE_ERROR;
1140                                 return 0;
1141                                 }
1142                         if (s->srp_ctx.login != NULL)
1143                                 {
1144                                 *al = SSL_AD_DECODE_ERROR;
1145                                 return 0;
1146                                 }
1147                         if ((s->srp_ctx.login = OPENSSL_malloc(len+1)) == NULL)
1148                                 return -1;
1149                         memcpy(s->srp_ctx.login, &data[1], len);
1150                         s->srp_ctx.login[len]='\0';
1151
1152                         if (strlen(s->srp_ctx.login) != len)
1153                                 {
1154                                 *al = SSL_AD_DECODE_ERROR;
1155                                 return 0;
1156                                 }
1157                         }
1158 #endif
1159
1160 #ifndef OPENSSL_NO_EC
1161                 else if (type == TLSEXT_TYPE_ec_point_formats)
1162                         {
1163                         unsigned char *sdata = data;
1164                         int ecpointformatlist_length = *(sdata++);
1165
1166                         if (ecpointformatlist_length != size - 1)
1167                                 {
1168                                 *al = TLS1_AD_DECODE_ERROR;
1169                                 return 0;
1170                                 }
1171                         if (!s->hit)
1172                                 {
1173                                 if(s->session->tlsext_ecpointformatlist)
1174                                         {
1175                                         OPENSSL_free(s->session->tlsext_ecpointformatlist);
1176                                         s->session->tlsext_ecpointformatlist = NULL;
1177                                         }
1178                                 s->session->tlsext_ecpointformatlist_length = 0;
1179                                 if ((s->session->tlsext_ecpointformatlist = OPENSSL_malloc(ecpointformatlist_length)) == NULL)
1180                                         {
1181                                         *al = TLS1_AD_INTERNAL_ERROR;
1182                                         return 0;
1183                                         }
1184                                 s->session->tlsext_ecpointformatlist_length = ecpointformatlist_length;
1185                                 memcpy(s->session->tlsext_ecpointformatlist, sdata, ecpointformatlist_length);
1186                                 }
1187 #if 0
1188                         fprintf(stderr,"ssl_parse_clienthello_tlsext s->session->tlsext_ecpointformatlist (length=%i) ", s->session->tlsext_ecpointformatlist_length);
1189                         sdata = s->session->tlsext_ecpointformatlist;
1190                         for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
1191                                 fprintf(stderr,"%i ",*(sdata++));
1192                         fprintf(stderr,"\n");
1193 #endif
1194                         }
1195                 else if (type == TLSEXT_TYPE_elliptic_curves)
1196                         {
1197                         unsigned char *sdata = data;
1198                         int ellipticcurvelist_length = (*(sdata++) << 8);
1199                         ellipticcurvelist_length += (*(sdata++));
1200
1201                         if (ellipticcurvelist_length != size - 2 ||
1202                                 ellipticcurvelist_length < 1)
1203                                 {
1204                                 *al = TLS1_AD_DECODE_ERROR;
1205                                 return 0;
1206                                 }
1207                         if (!s->hit)
1208                                 {
1209                                 if(s->session->tlsext_ellipticcurvelist)
1210                                         {
1211                                         *al = TLS1_AD_DECODE_ERROR;
1212                                         return 0;
1213                                         }
1214                                 s->session->tlsext_ellipticcurvelist_length = 0;
1215                                 if ((s->session->tlsext_ellipticcurvelist = OPENSSL_malloc(ellipticcurvelist_length)) == NULL)
1216                                         {
1217                                         *al = TLS1_AD_INTERNAL_ERROR;
1218                                         return 0;
1219                                         }
1220                                 s->session->tlsext_ellipticcurvelist_length = ellipticcurvelist_length;
1221                                 memcpy(s->session->tlsext_ellipticcurvelist, sdata, ellipticcurvelist_length);
1222                                 }
1223 #if 0
1224                         fprintf(stderr,"ssl_parse_clienthello_tlsext s->session->tlsext_ellipticcurvelist (length=%i) ", s->session->tlsext_ellipticcurvelist_length);
1225                         sdata = s->session->tlsext_ellipticcurvelist;
1226                         for (i = 0; i < s->session->tlsext_ellipticcurvelist_length; i++)
1227                                 fprintf(stderr,"%i ",*(sdata++));
1228                         fprintf(stderr,"\n");
1229 #endif
1230                         }
1231 #endif /* OPENSSL_NO_EC */
1232 #ifdef TLSEXT_TYPE_opaque_prf_input
1233                 else if (type == TLSEXT_TYPE_opaque_prf_input &&
1234                      s->version != DTLS1_VERSION)
1235                         {
1236                         unsigned char *sdata = data;
1237
1238                         if (size < 2)
1239                                 {
1240                                 *al = SSL_AD_DECODE_ERROR;
1241                                 return 0;
1242                                 }
1243                         n2s(sdata, s->s3->client_opaque_prf_input_len);
1244                         if (s->s3->client_opaque_prf_input_len != size - 2)
1245                                 {
1246                                 *al = SSL_AD_DECODE_ERROR;
1247                                 return 0;
1248                                 }
1249
1250                         if (s->s3->client_opaque_prf_input != NULL) /* shouldn't really happen */
1251                                 OPENSSL_free(s->s3->client_opaque_prf_input);
1252                         if (s->s3->client_opaque_prf_input_len == 0)
1253                                 s->s3->client_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
1254                         else
1255                                 s->s3->client_opaque_prf_input = BUF_memdup(sdata, s->s3->client_opaque_prf_input_len);
1256                         if (s->s3->client_opaque_prf_input == NULL)
1257                                 {
1258                                 *al = TLS1_AD_INTERNAL_ERROR;
1259                                 return 0;
1260                                 }
1261                         }
1262 #endif
1263                 else if (type == TLSEXT_TYPE_session_ticket)
1264                         {
1265                         if (s->tls_session_ticket_ext_cb &&
1266                             !s->tls_session_ticket_ext_cb(s, data, size, s->tls_session_ticket_ext_cb_arg))
1267                                 {
1268                                 *al = TLS1_AD_INTERNAL_ERROR;
1269                                 return 0;
1270                                 }
1271                         }
1272                 else if (type == TLSEXT_TYPE_renegotiate)
1273                         {
1274                         if(!ssl_parse_clienthello_renegotiate_ext(s, data, size, al))
1275                                 return 0;
1276                         renegotiate_seen = 1;
1277                         }
1278                 else if (type == TLSEXT_TYPE_signature_algorithms)
1279                         {
1280                         int dsize;
1281                         if (sigalg_seen || size < 2)
1282                                 {
1283                                 *al = SSL_AD_DECODE_ERROR;
1284                                 return 0;
1285                                 }
1286                         sigalg_seen = 1;
1287                         n2s(data,dsize);
1288                         size -= 2;
1289                         if (dsize != size || dsize & 1)
1290                                 {
1291                                 *al = SSL_AD_DECODE_ERROR;
1292                                 return 0;
1293                                 }
1294                         if (!tls1_process_sigalgs(s, data, dsize))
1295                                 {
1296                                 *al = SSL_AD_DECODE_ERROR;
1297                                 return 0;
1298                                 }
1299                         }
1300                 else if (type == TLSEXT_TYPE_status_request &&
1301                          s->version != DTLS1_VERSION)
1302                         {
1303
1304                         if (size < 5)
1305                                 {
1306                                 *al = SSL_AD_DECODE_ERROR;
1307                                 return 0;
1308                                 }
1309
1310                         s->tlsext_status_type = *data++;
1311                         size--;
1312                         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
1313                                 {
1314                                 const unsigned char *sdata;
1315                                 int dsize;
1316                                 /* Read in responder_id_list */
1317                                 n2s(data,dsize);
1318                                 size -= 2;
1319                                 if (dsize > size  )
1320                                         {
1321                                         *al = SSL_AD_DECODE_ERROR;
1322                                         return 0;
1323                                         }
1324                                 while (dsize > 0)
1325                                         {
1326                                         OCSP_RESPID *id;
1327                                         int idsize;
1328                                         if (dsize < 4)
1329                                                 {
1330                                                 *al = SSL_AD_DECODE_ERROR;
1331                                                 return 0;
1332                                                 }
1333                                         n2s(data, idsize);
1334                                         dsize -= 2 + idsize;
1335                                         size -= 2 + idsize;
1336                                         if (dsize < 0)
1337                                                 {
1338                                                 *al = SSL_AD_DECODE_ERROR;
1339                                                 return 0;
1340                                                 }
1341                                         sdata = data;
1342                                         data += idsize;
1343                                         id = d2i_OCSP_RESPID(NULL,
1344                                                                 &sdata, idsize);
1345                                         if (!id)
1346                                                 {
1347                                                 *al = SSL_AD_DECODE_ERROR;
1348                                                 return 0;
1349                                                 }
1350                                         if (data != sdata)
1351                                                 {
1352                                                 OCSP_RESPID_free(id);
1353                                                 *al = SSL_AD_DECODE_ERROR;
1354                                                 return 0;
1355                                                 }
1356                                         if (!s->tlsext_ocsp_ids
1357                                                 && !(s->tlsext_ocsp_ids =
1358                                                 sk_OCSP_RESPID_new_null()))
1359                                                 {
1360                                                 OCSP_RESPID_free(id);
1361                                                 *al = SSL_AD_INTERNAL_ERROR;
1362                                                 return 0;
1363                                                 }
1364                                         if (!sk_OCSP_RESPID_push(
1365                                                         s->tlsext_ocsp_ids, id))
1366                                                 {
1367                                                 OCSP_RESPID_free(id);
1368                                                 *al = SSL_AD_INTERNAL_ERROR;
1369                                                 return 0;
1370                                                 }
1371                                         }
1372
1373                                 /* Read in request_extensions */
1374                                 if (size < 2)
1375                                         {
1376                                         *al = SSL_AD_DECODE_ERROR;
1377                                         return 0;
1378                                         }
1379                                 n2s(data,dsize);
1380                                 size -= 2;
1381                                 if (dsize != size)
1382                                         {
1383                                         *al = SSL_AD_DECODE_ERROR;
1384                                         return 0;
1385                                         }
1386                                 sdata = data;
1387                                 if (dsize > 0)
1388                                         {
1389                                         if (s->tlsext_ocsp_exts)
1390                                                 {
1391                                                 sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts,
1392                                                                            X509_EXTENSION_free);
1393                                                 }
1394
1395                                         s->tlsext_ocsp_exts =
1396                                                 d2i_X509_EXTENSIONS(NULL,
1397                                                         &sdata, dsize);
1398                                         if (!s->tlsext_ocsp_exts
1399                                                 || (data + dsize != sdata))
1400                                                 {
1401                                                 *al = SSL_AD_DECODE_ERROR;
1402                                                 return 0;
1403                                                 }
1404                                         }
1405                                 }
1406                                 /* We don't know what to do with any other type
1407                                 * so ignore it.
1408                                 */
1409                                 else
1410                                         s->tlsext_status_type = -1;
1411                         }
1412 #ifndef OPENSSL_NO_HEARTBEATS
1413                 else if (type == TLSEXT_TYPE_heartbeat)
1414                         {
1415                         switch(data[0])
1416                                 {
1417                                 case 0x01:      /* Client allows us to send HB requests */
1418                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
1419                                                         break;
1420                                 case 0x02:      /* Client doesn't accept HB requests */
1421                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
1422                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
1423                                                         break;
1424                                 default:        *al = SSL_AD_ILLEGAL_PARAMETER;
1425                                                         return 0;
1426                                 }
1427                         }
1428 #endif
1429 #ifndef OPENSSL_NO_NEXTPROTONEG
1430                 else if (type == TLSEXT_TYPE_next_proto_neg &&
1431                          s->s3->tmp.finish_md_len == 0)
1432                         {
1433                         /* We shouldn't accept this extension on a
1434                          * renegotiation.
1435                          *
1436                          * s->new_session will be set on renegotiation, but we
1437                          * probably shouldn't rely that it couldn't be set on
1438                          * the initial renegotation too in certain cases (when
1439                          * there's some other reason to disallow resuming an
1440                          * earlier session -- the current code won't be doing
1441                          * anything like that, but this might change).
1442
1443                          * A valid sign that there's been a previous handshake
1444                          * in this connection is if s->s3->tmp.finish_md_len >
1445                          * 0.  (We are talking about a check that will happen
1446                          * in the Hello protocol round, well before a new
1447                          * Finished message could have been computed.) */
1448                         s->s3->next_proto_neg_seen = 1;
1449                         }
1450 #endif
1451
1452                 /* session ticket processed earlier */
1453 #ifndef OPENSSL_NO_SRTP
1454                 else if (SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s)
1455                          && type == TLSEXT_TYPE_use_srtp)
1456                         {
1457                         if(ssl_parse_clienthello_use_srtp_ext(s, data, size,
1458                                                               al))
1459                                 return 0;
1460                         }
1461 #endif
1462
1463                 data+=size;
1464                 }
1465
1466         *p = data;
1467
1468         ri_check:
1469
1470         /* Need RI if renegotiating */
1471
1472         if (!renegotiate_seen && s->renegotiate &&
1473                 !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
1474                 {
1475                 *al = SSL_AD_HANDSHAKE_FAILURE;
1476                 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT,
1477                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
1478                 return 0;
1479                 }
1480
1481         return 1;
1482         }
1483
1484 #ifndef OPENSSL_NO_NEXTPROTONEG
1485 /* ssl_next_proto_validate validates a Next Protocol Negotiation block. No
1486  * elements of zero length are allowed and the set of elements must exactly fill
1487  * the length of the block. */
1488 static char ssl_next_proto_validate(unsigned char *d, unsigned len)
1489         {
1490         unsigned int off = 0;
1491
1492         while (off < len)
1493                 {
1494                 if (d[off] == 0)
1495                         return 0;
1496                 off += d[off];
1497                 off++;
1498                 }
1499
1500         return off == len;
1501         }
1502 #endif
1503
1504 int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
1505         {
1506         unsigned short length;
1507         unsigned short type;
1508         unsigned short size;
1509         unsigned char *data = *p;
1510         int tlsext_servername = 0;
1511         int renegotiate_seen = 0;
1512
1513 #ifndef OPENSSL_NO_NEXTPROTONEG
1514         s->s3->next_proto_neg_seen = 0;
1515 #endif
1516
1517 #ifndef OPENSSL_NO_HEARTBEATS
1518         s->tlsext_heartbeat &= ~(SSL_TLSEXT_HB_ENABLED |
1519                                SSL_TLSEXT_HB_DONT_SEND_REQUESTS);
1520 #endif
1521
1522         if (data >= (d+n-2))
1523                 goto ri_check;
1524
1525         n2s(data,length);
1526         if (data+length != d+n)
1527                 {
1528                 *al = SSL_AD_DECODE_ERROR;
1529                 return 0;
1530                 }
1531
1532         while(data <= (d+n-4))
1533                 {
1534                 n2s(data,type);
1535                 n2s(data,size);
1536
1537                 if (data+size > (d+n))
1538                         goto ri_check;
1539
1540                 if (s->tlsext_debug_cb)
1541                         s->tlsext_debug_cb(s, 1, type, data, size,
1542                                                 s->tlsext_debug_arg);
1543
1544                 if (type == TLSEXT_TYPE_server_name)
1545                         {
1546                         if (s->tlsext_hostname == NULL || size > 0)
1547                                 {
1548                                 *al = TLS1_AD_UNRECOGNIZED_NAME;
1549                                 return 0;
1550                                 }
1551                         tlsext_servername = 1;
1552                         }
1553
1554 #ifndef OPENSSL_NO_EC
1555                 else if (type == TLSEXT_TYPE_ec_point_formats)
1556                         {
1557                         unsigned char *sdata = data;
1558                         int ecpointformatlist_length = *(sdata++);
1559
1560                         if (ecpointformatlist_length != size - 1 ||
1561                                 ecpointformatlist_length < 1)
1562                                 {
1563                                 *al = TLS1_AD_DECODE_ERROR;
1564                                 return 0;
1565                                 }
1566                         if (!s->hit)
1567                                 {
1568                                 s->session->tlsext_ecpointformatlist_length = 0;
1569                                 if (s->session->tlsext_ecpointformatlist != NULL) OPENSSL_free(s->session->tlsext_ecpointformatlist);
1570                                 if ((s->session->tlsext_ecpointformatlist = OPENSSL_malloc(ecpointformatlist_length)) == NULL)
1571                                         {
1572                                         *al = TLS1_AD_INTERNAL_ERROR;
1573                                         return 0;
1574                                         }
1575                                 s->session->tlsext_ecpointformatlist_length = ecpointformatlist_length;
1576                                 memcpy(s->session->tlsext_ecpointformatlist, sdata, ecpointformatlist_length);
1577                                 }
1578 #if 0
1579                         fprintf(stderr,"ssl_parse_serverhello_tlsext s->session->tlsext_ecpointformatlist ");
1580                         sdata = s->session->tlsext_ecpointformatlist;
1581                         for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
1582                                 fprintf(stderr,"%i ",*(sdata++));
1583                         fprintf(stderr,"\n");
1584 #endif
1585                         }
1586 #endif /* OPENSSL_NO_EC */
1587
1588                 else if (type == TLSEXT_TYPE_session_ticket)
1589                         {
1590                         if (s->tls_session_ticket_ext_cb &&
1591                             !s->tls_session_ticket_ext_cb(s, data, size, s->tls_session_ticket_ext_cb_arg))
1592                                 {
1593                                 *al = TLS1_AD_INTERNAL_ERROR;
1594                                 return 0;
1595                                 }
1596                         if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
1597                                 || (size > 0))
1598                                 {
1599                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
1600                                 return 0;
1601                                 }
1602                         s->tlsext_ticket_expected = 1;
1603                         }
1604 #ifdef TLSEXT_TYPE_opaque_prf_input
1605                 else if (type == TLSEXT_TYPE_opaque_prf_input &&
1606                      s->version != DTLS1_VERSION)
1607                         {
1608                         unsigned char *sdata = data;
1609
1610                         if (size < 2)
1611                                 {
1612                                 *al = SSL_AD_DECODE_ERROR;
1613                                 return 0;
1614                                 }
1615                         n2s(sdata, s->s3->server_opaque_prf_input_len);
1616                         if (s->s3->server_opaque_prf_input_len != size - 2)
1617                                 {
1618                                 *al = SSL_AD_DECODE_ERROR;
1619                                 return 0;
1620                                 }
1621
1622                         if (s->s3->server_opaque_prf_input != NULL) /* shouldn't really happen */
1623                                 OPENSSL_free(s->s3->server_opaque_prf_input);
1624                         if (s->s3->server_opaque_prf_input_len == 0)
1625                                 s->s3->server_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
1626                         else
1627                                 s->s3->server_opaque_prf_input = BUF_memdup(sdata, s->s3->server_opaque_prf_input_len);
1628
1629                         if (s->s3->server_opaque_prf_input == NULL)
1630                                 {
1631                                 *al = TLS1_AD_INTERNAL_ERROR;
1632                                 return 0;
1633                                 }
1634                         }
1635 #endif
1636                 else if (type == TLSEXT_TYPE_status_request &&
1637                          s->version != DTLS1_VERSION)
1638                         {
1639                         /* MUST be empty and only sent if we've requested
1640                          * a status request message.
1641                          */
1642                         if ((s->tlsext_status_type == -1) || (size > 0))
1643                                 {
1644                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
1645                                 return 0;
1646                                 }
1647                         /* Set flag to expect CertificateStatus message */
1648                         s->tlsext_status_expected = 1;
1649                         }
1650 #ifndef OPENSSL_NO_NEXTPROTONEG
1651                 else if (type == TLSEXT_TYPE_next_proto_neg &&
1652                          s->s3->tmp.finish_md_len == 0)
1653                         {
1654                         unsigned char *selected;
1655                         unsigned char selected_len;
1656
1657                         /* We must have requested it. */
1658                         if (s->ctx->next_proto_select_cb == NULL)
1659                                 {
1660                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
1661                                 return 0;
1662                                 }
1663                         /* The data must be valid */
1664                         if (!ssl_next_proto_validate(data, size))
1665                                 {
1666                                 *al = TLS1_AD_DECODE_ERROR;
1667                                 return 0;
1668                                 }
1669                         if (s->ctx->next_proto_select_cb(s, &selected, &selected_len, data, size, s->ctx->next_proto_select_cb_arg) != SSL_TLSEXT_ERR_OK)
1670                                 {
1671                                 *al = TLS1_AD_INTERNAL_ERROR;
1672                                 return 0;
1673                                 }
1674                         s->next_proto_negotiated = OPENSSL_malloc(selected_len);
1675                         if (!s->next_proto_negotiated)
1676                                 {
1677                                 *al = TLS1_AD_INTERNAL_ERROR;
1678                                 return 0;
1679                                 }
1680                         memcpy(s->next_proto_negotiated, selected, selected_len);
1681                         s->next_proto_negotiated_len = selected_len;
1682                         s->s3->next_proto_neg_seen = 1;
1683                         }
1684 #endif
1685                 else if (type == TLSEXT_TYPE_renegotiate)
1686                         {
1687                         if(!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
1688                                 return 0;
1689                         renegotiate_seen = 1;
1690                         }
1691 #ifndef OPENSSL_NO_HEARTBEATS
1692                 else if (type == TLSEXT_TYPE_heartbeat)
1693                         {
1694                         switch(data[0])
1695                                 {
1696                                 case 0x01:      /* Server allows us to send HB requests */
1697                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
1698                                                         break;
1699                                 case 0x02:      /* Server doesn't accept HB requests */
1700                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
1701                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
1702                                                         break;
1703                                 default:        *al = SSL_AD_ILLEGAL_PARAMETER;
1704                                                         return 0;
1705                                 }
1706                         }
1707 #endif
1708 #ifndef OPENSSL_NO_SRTP
1709                 else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_use_srtp)
1710                         {
1711                         if(ssl_parse_serverhello_use_srtp_ext(s, data, size,
1712                                                               al))
1713                                 return 0;
1714                         }
1715 #endif
1716
1717                 data+=size;
1718                 }
1719
1720         if (data != d+n)
1721                 {
1722                 *al = SSL_AD_DECODE_ERROR;
1723                 return 0;
1724                 }
1725
1726         if (!s->hit && tlsext_servername == 1)
1727                 {
1728                 if (s->tlsext_hostname)
1729                         {
1730                         if (s->session->tlsext_hostname == NULL)
1731                                 {
1732                                 s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);
1733                                 if (!s->session->tlsext_hostname)
1734                                         {
1735                                         *al = SSL_AD_UNRECOGNIZED_NAME;
1736                                         return 0;
1737                                         }
1738                                 }
1739                         else
1740                                 {
1741                                 *al = SSL_AD_DECODE_ERROR;
1742                                 return 0;
1743                                 }
1744                         }
1745                 }
1746
1747         *p = data;
1748
1749         ri_check:
1750
1751         /* Determine if we need to see RI. Strictly speaking if we want to
1752          * avoid an attack we should *always* see RI even on initial server
1753          * hello because the client doesn't see any renegotiation during an
1754          * attack. However this would mean we could not connect to any server
1755          * which doesn't support RI so for the immediate future tolerate RI
1756          * absence on initial connect only.
1757          */
1758         if (!renegotiate_seen
1759                 && !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
1760                 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
1761                 {
1762                 *al = SSL_AD_HANDSHAKE_FAILURE;
1763                 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT,
1764                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
1765                 return 0;
1766                 }
1767
1768         return 1;
1769         }
1770
1771
1772 int ssl_prepare_clienthello_tlsext(SSL *s)
1773         {
1774 #ifndef OPENSSL_NO_EC
1775         /* If we are client and using an elliptic curve cryptography cipher suite, send the point formats
1776          * and elliptic curves we support.
1777          */
1778         int using_ecc = 0;
1779         int i;
1780         unsigned char *j;
1781         unsigned long alg_k, alg_a;
1782         STACK_OF(SSL_CIPHER) *cipher_stack = SSL_get_ciphers(s);
1783
1784         for (i = 0; i < sk_SSL_CIPHER_num(cipher_stack); i++)
1785                 {
1786                 SSL_CIPHER *c = sk_SSL_CIPHER_value(cipher_stack, i);
1787
1788                 alg_k = c->algorithm_mkey;
1789                 alg_a = c->algorithm_auth;
1790                 if ((alg_k & (SSL_kEECDH|SSL_kECDHr|SSL_kECDHe) || (alg_a & SSL_aECDSA)))
1791                         {
1792                         using_ecc = 1;
1793                         break;
1794                         }
1795                 }
1796         using_ecc = using_ecc && (s->version >= TLS1_VERSION);
1797         if (using_ecc)
1798                 {
1799                 if (s->tlsext_ecpointformatlist != NULL) OPENSSL_free(s->tlsext_ecpointformatlist);
1800                 if ((s->tlsext_ecpointformatlist = OPENSSL_malloc(3)) == NULL)
1801                         {
1802                         SSLerr(SSL_F_SSL_PREPARE_CLIENTHELLO_TLSEXT,ERR_R_MALLOC_FAILURE);
1803                         return -1;
1804                         }
1805                 s->tlsext_ecpointformatlist_length = 3;
1806                 s->tlsext_ecpointformatlist[0] = TLSEXT_ECPOINTFORMAT_uncompressed;
1807                 s->tlsext_ecpointformatlist[1] = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
1808                 s->tlsext_ecpointformatlist[2] = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
1809
1810                 /* we support all named elliptic curves in RFC 4492 */
1811                 if (s->tlsext_ellipticcurvelist != NULL) OPENSSL_free(s->tlsext_ellipticcurvelist);
1812                 s->tlsext_ellipticcurvelist_length = sizeof(pref_list)/sizeof(pref_list[0]) * 2;
1813                 if ((s->tlsext_ellipticcurvelist = OPENSSL_malloc(s->tlsext_ellipticcurvelist_length)) == NULL)
1814                         {
1815                         s->tlsext_ellipticcurvelist_length = 0;
1816                         SSLerr(SSL_F_SSL_PREPARE_CLIENTHELLO_TLSEXT,ERR_R_MALLOC_FAILURE);
1817                         return -1;
1818                         }
1819                 for (i = 0, j = s->tlsext_ellipticcurvelist; (unsigned int)i <
1820                                 sizeof(pref_list)/sizeof(pref_list[0]); i++)
1821                         {
1822                         int id = tls1_ec_nid2curve_id(pref_list[i]);
1823                         s2n(id,j);
1824                         }
1825                 }
1826 #endif /* OPENSSL_NO_EC */
1827
1828 #ifdef TLSEXT_TYPE_opaque_prf_input
1829         {
1830                 int r = 1;
1831
1832                 if (s->ctx->tlsext_opaque_prf_input_callback != 0)
1833                         {
1834                         r = s->ctx->tlsext_opaque_prf_input_callback(s, NULL, 0, s->ctx->tlsext_opaque_prf_input_callback_arg);
1835                         if (!r)
1836                                 return -1;
1837                         }
1838
1839                 if (s->tlsext_opaque_prf_input != NULL)
1840                         {
1841                         if (s->s3->client_opaque_prf_input != NULL) /* shouldn't really happen */
1842                                 OPENSSL_free(s->s3->client_opaque_prf_input);
1843
1844                         if (s->tlsext_opaque_prf_input_len == 0)
1845                                 s->s3->client_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
1846                         else
1847                                 s->s3->client_opaque_prf_input = BUF_memdup(s->tlsext_opaque_prf_input, s->tlsext_opaque_prf_input_len);
1848                         if (s->s3->client_opaque_prf_input == NULL)
1849                                 {
1850                                 SSLerr(SSL_F_SSL_PREPARE_CLIENTHELLO_TLSEXT,ERR_R_MALLOC_FAILURE);
1851                                 return -1;
1852                                 }
1853                         s->s3->client_opaque_prf_input_len = s->tlsext_opaque_prf_input_len;
1854                         }
1855
1856                 if (r == 2)
1857                         /* at callback's request, insist on receiving an appropriate server opaque PRF input */
1858                         s->s3->server_opaque_prf_input_len = s->tlsext_opaque_prf_input_len;
1859         }
1860 #endif
1861
1862         return 1;
1863         }
1864
1865 int ssl_prepare_serverhello_tlsext(SSL *s)
1866         {
1867 #ifndef OPENSSL_NO_EC
1868         /* If we are server and using an ECC cipher suite, send the point formats we support
1869          * if the client sent us an ECPointsFormat extension.  Note that the server is not
1870          * supposed to send an EllipticCurves extension.
1871          */
1872
1873         unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
1874         unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
1875         int using_ecc = (alg_k & (SSL_kEECDH|SSL_kECDHr|SSL_kECDHe)) || (alg_a & SSL_aECDSA);
1876         using_ecc = using_ecc && (s->session->tlsext_ecpointformatlist != NULL);
1877
1878         if (using_ecc)
1879                 {
1880                 if (s->tlsext_ecpointformatlist != NULL) OPENSSL_free(s->tlsext_ecpointformatlist);
1881                 if ((s->tlsext_ecpointformatlist = OPENSSL_malloc(3)) == NULL)
1882                         {
1883                         SSLerr(SSL_F_SSL_PREPARE_SERVERHELLO_TLSEXT,ERR_R_MALLOC_FAILURE);
1884                         return -1;
1885                         }
1886                 s->tlsext_ecpointformatlist_length = 3;
1887                 s->tlsext_ecpointformatlist[0] = TLSEXT_ECPOINTFORMAT_uncompressed;
1888                 s->tlsext_ecpointformatlist[1] = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
1889                 s->tlsext_ecpointformatlist[2] = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
1890                 }
1891 #endif /* OPENSSL_NO_EC */
1892
1893         return 1;
1894         }
1895
1896 int ssl_check_clienthello_tlsext_early(SSL *s)
1897         {
1898         int ret=SSL_TLSEXT_ERR_NOACK;
1899         int al = SSL_AD_UNRECOGNIZED_NAME;
1900
1901 #ifndef OPENSSL_NO_EC
1902         /* The handling of the ECPointFormats extension is done elsewhere, namely in
1903          * ssl3_choose_cipher in s3_lib.c.
1904          */
1905         /* The handling of the EllipticCurves extension is done elsewhere, namely in
1906          * ssl3_choose_cipher in s3_lib.c.
1907          */
1908 #endif
1909
1910         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
1911                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
1912         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
1913                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
1914
1915 #ifdef TLSEXT_TYPE_opaque_prf_input
1916         {
1917                 /* This sort of belongs into ssl_prepare_serverhello_tlsext(),
1918                  * but we might be sending an alert in response to the client hello,
1919                  * so this has to happen here in
1920                  * ssl_check_clienthello_tlsext_early(). */
1921
1922                 int r = 1;
1923
1924                 if (s->ctx->tlsext_opaque_prf_input_callback != 0)
1925                         {
1926                         r = s->ctx->tlsext_opaque_prf_input_callback(s, NULL, 0, s->ctx->tlsext_opaque_prf_input_callback_arg);
1927                         if (!r)
1928                                 {
1929                                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
1930                                 al = SSL_AD_INTERNAL_ERROR;
1931                                 goto err;
1932                                 }
1933                         }
1934
1935                 if (s->s3->server_opaque_prf_input != NULL) /* shouldn't really happen */
1936                         OPENSSL_free(s->s3->server_opaque_prf_input);
1937                 s->s3->server_opaque_prf_input = NULL;
1938
1939                 if (s->tlsext_opaque_prf_input != NULL)
1940                         {
1941                         if (s->s3->client_opaque_prf_input != NULL &&
1942                                 s->s3->client_opaque_prf_input_len == s->tlsext_opaque_prf_input_len)
1943                                 {
1944                                 /* can only use this extension if we have a server opaque PRF input
1945                                  * of the same length as the client opaque PRF input! */
1946
1947                                 if (s->tlsext_opaque_prf_input_len == 0)
1948                                         s->s3->server_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
1949                                 else
1950                                         s->s3->server_opaque_prf_input = BUF_memdup(s->tlsext_opaque_prf_input, s->tlsext_opaque_prf_input_len);
1951                                 if (s->s3->server_opaque_prf_input == NULL)
1952                                         {
1953                                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
1954                                         al = SSL_AD_INTERNAL_ERROR;
1955                                         goto err;
1956                                         }
1957                                 s->s3->server_opaque_prf_input_len = s->tlsext_opaque_prf_input_len;
1958                                 }
1959                         }
1960
1961                 if (r == 2 && s->s3->server_opaque_prf_input == NULL)
1962                         {
1963                         /* The callback wants to enforce use of the extension,
1964                          * but we can't do that with the client opaque PRF input;
1965                          * abort the handshake.
1966                          */
1967                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
1968                         al = SSL_AD_HANDSHAKE_FAILURE;
1969                         }
1970         }
1971
1972  err:
1973 #endif
1974         switch (ret)
1975                 {
1976                 case SSL_TLSEXT_ERR_ALERT_FATAL:
1977                         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1978                         return -1;
1979
1980                 case SSL_TLSEXT_ERR_ALERT_WARNING:
1981                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
1982                         return 1;
1983
1984                 case SSL_TLSEXT_ERR_NOACK:
1985                         s->servername_done=0;
1986                         default:
1987                 return 1;
1988                 }
1989         }
1990
1991 int ssl_check_clienthello_tlsext_late(SSL *s)
1992         {
1993         int ret = SSL_TLSEXT_ERR_OK;
1994         int al;
1995
1996         /* If status request then ask callback what to do.
1997          * Note: this must be called after servername callbacks in case
1998          * the certificate has changed, and must be called after the cipher
1999          * has been chosen because this may influence which certificate is sent
2000          */
2001         if ((s->tlsext_status_type != -1) && s->ctx && s->ctx->tlsext_status_cb)
2002                 {
2003                 int r;
2004                 CERT_PKEY *certpkey;
2005                 certpkey = ssl_get_server_send_pkey(s);
2006                 /* If no certificate can't return certificate status */
2007                 if (certpkey == NULL)
2008                         {
2009                         s->tlsext_status_expected = 0;
2010                         return 1;
2011                         }
2012                 /* Set current certificate to one we will use so
2013                  * SSL_get_certificate et al can pick it up.
2014                  */
2015                 s->cert->key = certpkey;
2016                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
2017                 switch (r)
2018                         {
2019                         /* We don't want to send a status request response */
2020                         case SSL_TLSEXT_ERR_NOACK:
2021                                 s->tlsext_status_expected = 0;
2022                                 break;
2023                         /* status request response should be sent */
2024                         case SSL_TLSEXT_ERR_OK:
2025                                 if (s->tlsext_ocsp_resp)
2026                                         s->tlsext_status_expected = 1;
2027                                 else
2028                                         s->tlsext_status_expected = 0;
2029                                 break;
2030                         /* something bad happened */
2031                         case SSL_TLSEXT_ERR_ALERT_FATAL:
2032                                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
2033                                 al = SSL_AD_INTERNAL_ERROR;
2034                                 goto err;
2035                         }
2036                 }
2037         else
2038                 s->tlsext_status_expected = 0;
2039
2040  err:
2041         switch (ret)
2042                 {
2043                 case SSL_TLSEXT_ERR_ALERT_FATAL:
2044                         ssl3_send_alert(s,SSL3_AL_FATAL,al);
2045                         return -1;
2046
2047                 case SSL_TLSEXT_ERR_ALERT_WARNING:
2048                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
2049                         return 1;
2050
2051                 default:
2052                         return 1;
2053                 }
2054         }
2055
2056 int ssl_check_serverhello_tlsext(SSL *s)
2057         {
2058         int ret=SSL_TLSEXT_ERR_NOACK;
2059         int al = SSL_AD_UNRECOGNIZED_NAME;
2060
2061 #ifndef OPENSSL_NO_EC
2062         /* If we are client and using an elliptic curve cryptography cipher
2063          * suite, then if server returns an EC point formats lists extension
2064          * it must contain uncompressed.
2065          */
2066         unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
2067         unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
2068         if ((s->tlsext_ecpointformatlist != NULL) && (s->tlsext_ecpointformatlist_length > 0) &&
2069             (s->session->tlsext_ecpointformatlist != NULL) && (s->session->tlsext_ecpointformatlist_length > 0) &&
2070             ((alg_k & (SSL_kEECDH|SSL_kECDHr|SSL_kECDHe)) || (alg_a & SSL_aECDSA)))
2071                 {
2072                 /* we are using an ECC cipher */
2073                 size_t i;
2074                 unsigned char *list;
2075                 int found_uncompressed = 0;
2076                 list = s->session->tlsext_ecpointformatlist;
2077                 for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
2078                         {
2079                         if (*(list++) == TLSEXT_ECPOINTFORMAT_uncompressed)
2080                                 {
2081                                 found_uncompressed = 1;
2082                                 break;
2083                                 }
2084                         }
2085                 if (!found_uncompressed)
2086                         {
2087                         SSLerr(SSL_F_SSL_CHECK_SERVERHELLO_TLSEXT,SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
2088                         return -1;
2089                         }
2090                 }
2091         ret = SSL_TLSEXT_ERR_OK;
2092 #endif /* OPENSSL_NO_EC */
2093
2094         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
2095                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
2096         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
2097                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
2098
2099 #ifdef TLSEXT_TYPE_opaque_prf_input
2100         if (s->s3->server_opaque_prf_input_len > 0)
2101                 {
2102                 /* This case may indicate that we, as a client, want to insist on using opaque PRF inputs.
2103                  * So first verify that we really have a value from the server too. */
2104
2105                 if (s->s3->server_opaque_prf_input == NULL)
2106                         {
2107                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
2108                         al = SSL_AD_HANDSHAKE_FAILURE;
2109                         }
2110
2111                 /* Anytime the server *has* sent an opaque PRF input, we need to check
2112                  * that we have a client opaque PRF input of the same size. */
2113                 if (s->s3->client_opaque_prf_input == NULL ||
2114                     s->s3->client_opaque_prf_input_len != s->s3->server_opaque_prf_input_len)
2115                         {
2116                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
2117                         al = SSL_AD_ILLEGAL_PARAMETER;
2118                         }
2119                 }
2120 #endif
2121
2122         /* If we've requested certificate status and we wont get one
2123          * tell the callback
2124          */
2125         if ((s->tlsext_status_type != -1) && !(s->tlsext_status_expected)
2126                         && s->ctx && s->ctx->tlsext_status_cb)
2127                 {
2128                 int r;
2129                 /* Set resp to NULL, resplen to -1 so callback knows
2130                  * there is no response.
2131                  */
2132                 if (s->tlsext_ocsp_resp)
2133                         {
2134                         OPENSSL_free(s->tlsext_ocsp_resp);
2135                         s->tlsext_ocsp_resp = NULL;
2136                         }
2137                 s->tlsext_ocsp_resplen = -1;
2138                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
2139                 if (r == 0)
2140                         {
2141                         al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
2142                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
2143                         }
2144                 if (r < 0)
2145                         {
2146                         al = SSL_AD_INTERNAL_ERROR;
2147                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
2148                         }
2149                 }
2150
2151         switch (ret)
2152                 {
2153                 case SSL_TLSEXT_ERR_ALERT_FATAL:
2154                         ssl3_send_alert(s,SSL3_AL_FATAL,al);
2155                         return -1;
2156
2157                 case SSL_TLSEXT_ERR_ALERT_WARNING:
2158                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
2159                         return 1;
2160
2161                 case SSL_TLSEXT_ERR_NOACK:
2162                         s->servername_done=0;
2163                         default:
2164                 return 1;
2165                 }
2166         }
2167
2168 /* Since the server cache lookup is done early on in the processing of the
2169  * ClientHello, and other operations depend on the result, we need to handle
2170  * any TLS session ticket extension at the same time.
2171  *
2172  *   session_id: points at the session ID in the ClientHello. This code will
2173  *       read past the end of this in order to parse out the session ticket
2174  *       extension, if any.
2175  *   len: the length of the session ID.
2176  *   limit: a pointer to the first byte after the ClientHello.
2177  *   ret: (output) on return, if a ticket was decrypted, then this is set to
2178  *       point to the resulting session.
2179  *
2180  * If s->tls_session_secret_cb is set then we are expecting a pre-shared key
2181  * ciphersuite, in which case we have no use for session tickets and one will
2182  * never be decrypted, nor will s->tlsext_ticket_expected be set to 1.
2183  *
2184  * Returns:
2185  *   -1: fatal error, either from parsing or decrypting the ticket.
2186  *    0: no ticket was found (or was ignored, based on settings).
2187  *    1: a zero length extension was found, indicating that the client supports
2188  *       session tickets but doesn't currently have one to offer.
2189  *    2: either s->tls_session_secret_cb was set, or a ticket was offered but
2190  *       couldn't be decrypted because of a non-fatal error.
2191  *    3: a ticket was successfully decrypted and *ret was set.
2192  *
2193  * Side effects:
2194  *   Sets s->tlsext_ticket_expected to 1 if the server will have to issue
2195  *   a new session ticket to the client because the client indicated support
2196  *   (and s->tls_session_secret_cb is NULL) but the client either doesn't have
2197  *   a session ticket or we couldn't use the one it gave us, or if
2198  *   s->ctx->tlsext_ticket_key_cb asked to renew the client's ticket.
2199  *   Otherwise, s->tlsext_ticket_expected is set to 0.
2200  */
2201 int tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
2202                         const unsigned char *limit, SSL_SESSION **ret)
2203         {
2204         /* Point after session ID in client hello */
2205         const unsigned char *p = session_id + len;
2206         unsigned short i;
2207
2208         *ret = NULL;
2209         s->tlsext_ticket_expected = 0;
2210
2211         /* If tickets disabled behave as if no ticket present
2212          * to permit stateful resumption.
2213          */
2214         if (SSL_get_options(s) & SSL_OP_NO_TICKET)
2215                 return 0;
2216         if ((s->version <= SSL3_VERSION) || !limit)
2217                 return 0;
2218         if (p >= limit)
2219                 return -1;
2220         /* Skip past DTLS cookie */
2221         if (s->version == DTLS1_VERSION || s->version == DTLS1_BAD_VER)
2222                 {
2223                 i = *(p++);
2224                 p+= i;
2225                 if (p >= limit)
2226                         return -1;
2227                 }
2228         /* Skip past cipher list */
2229         n2s(p, i);
2230         p+= i;
2231         if (p >= limit)
2232                 return -1;
2233         /* Skip past compression algorithm list */
2234         i = *(p++);
2235         p += i;
2236         if (p > limit)
2237                 return -1;
2238         /* Now at start of extensions */
2239         if ((p + 2) >= limit)
2240                 return 0;
2241         n2s(p, i);
2242         while ((p + 4) <= limit)
2243                 {
2244                 unsigned short type, size;
2245                 n2s(p, type);
2246                 n2s(p, size);
2247                 if (p + size > limit)
2248                         return 0;
2249                 if (type == TLSEXT_TYPE_session_ticket)
2250                         {
2251                         int r;
2252                         if (size == 0)
2253                                 {
2254                                 /* The client will accept a ticket but doesn't
2255                                  * currently have one. */
2256                                 s->tlsext_ticket_expected = 1;
2257                                 return 1;
2258                                 }
2259                         if (s->tls_session_secret_cb)
2260                                 {
2261                                 /* Indicate that the ticket couldn't be
2262                                  * decrypted rather than generating the session
2263                                  * from ticket now, trigger abbreviated
2264                                  * handshake based on external mechanism to
2265                                  * calculate the master secret later. */
2266                                 return 2;
2267                                 }
2268                         r = tls_decrypt_ticket(s, p, size, session_id, len, ret);
2269                         switch (r)
2270                                 {
2271                                 case 2: /* ticket couldn't be decrypted */
2272                                         s->tlsext_ticket_expected = 1;
2273                                         return 2;
2274                                 case 3: /* ticket was decrypted */
2275                                         return r;
2276                                 case 4: /* ticket decrypted but need to renew */
2277                                         s->tlsext_ticket_expected = 1;
2278                                         return 3;
2279                                 default: /* fatal error */
2280                                         return -1;
2281                                 }
2282                         }
2283                 p += size;
2284                 }
2285         return 0;
2286         }
2287
2288 /* tls_decrypt_ticket attempts to decrypt a session ticket.
2289  *
2290  *   etick: points to the body of the session ticket extension.
2291  *   eticklen: the length of the session tickets extenion.
2292  *   sess_id: points at the session ID.
2293  *   sesslen: the length of the session ID.
2294  *   psess: (output) on return, if a ticket was decrypted, then this is set to
2295  *       point to the resulting session.
2296  *
2297  * Returns:
2298  *   -1: fatal error, either from parsing or decrypting the ticket.
2299  *    2: the ticket couldn't be decrypted.
2300  *    3: a ticket was successfully decrypted and *psess was set.
2301  *    4: same as 3, but the ticket needs to be renewed.
2302  */
2303 static int tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen,
2304                                 const unsigned char *sess_id, int sesslen,
2305                                 SSL_SESSION **psess)
2306         {
2307         SSL_SESSION *sess;
2308         unsigned char *sdec;
2309         const unsigned char *p;
2310         int slen, mlen, renew_ticket = 0;
2311         unsigned char tick_hmac[EVP_MAX_MD_SIZE];
2312         HMAC_CTX hctx;
2313         EVP_CIPHER_CTX ctx;
2314         SSL_CTX *tctx = s->initial_ctx;
2315         /* Need at least keyname + iv + some encrypted data */
2316         if (eticklen < 48)
2317                 return 2;
2318         /* Initialize session ticket encryption and HMAC contexts */
2319         HMAC_CTX_init(&hctx);
2320         EVP_CIPHER_CTX_init(&ctx);
2321         if (tctx->tlsext_ticket_key_cb)
2322                 {
2323                 unsigned char *nctick = (unsigned char *)etick;
2324                 int rv = tctx->tlsext_ticket_key_cb(s, nctick, nctick + 16,
2325                                                         &ctx, &hctx, 0);
2326                 if (rv < 0)
2327                         return -1;
2328                 if (rv == 0)
2329                         return 2;
2330                 if (rv == 2)
2331                         renew_ticket = 1;
2332                 }
2333         else
2334                 {
2335                 /* Check key name matches */
2336                 if (memcmp(etick, tctx->tlsext_tick_key_name, 16))
2337                         return 2;
2338                 HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,
2339                                         tlsext_tick_md(), NULL);
2340                 EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
2341                                 tctx->tlsext_tick_aes_key, etick + 16);
2342                 }
2343         /* Attempt to process session ticket, first conduct sanity and
2344          * integrity checks on ticket.
2345          */
2346         mlen = HMAC_size(&hctx);
2347         if (mlen < 0)
2348                 {
2349                 EVP_CIPHER_CTX_cleanup(&ctx);
2350                 return -1;
2351                 }
2352         eticklen -= mlen;
2353         /* Check HMAC of encrypted ticket */
2354         HMAC_Update(&hctx, etick, eticklen);
2355         HMAC_Final(&hctx, tick_hmac, NULL);
2356         HMAC_CTX_cleanup(&hctx);
2357         if (CRYPTO_memcmp(tick_hmac, etick + eticklen, mlen))
2358                 {
2359                 EVP_CIPHER_CTX_cleanup(&ctx);
2360                 return 2;
2361                 }
2362         /* Attempt to decrypt session data */
2363         /* Move p after IV to start of encrypted ticket, update length */
2364         p = etick + 16 + EVP_CIPHER_CTX_iv_length(&ctx);
2365         eticklen -= 16 + EVP_CIPHER_CTX_iv_length(&ctx);
2366         sdec = OPENSSL_malloc(eticklen);
2367         if (!sdec)
2368                 {
2369                 EVP_CIPHER_CTX_cleanup(&ctx);
2370                 return -1;
2371                 }
2372         EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen);
2373         if (EVP_DecryptFinal(&ctx, sdec + slen, &mlen) <= 0)
2374                 {
2375                 EVP_CIPHER_CTX_cleanup(&ctx);
2376                 OPENSSL_free(sdec);
2377                 return 2;
2378                 }
2379         slen += mlen;
2380         EVP_CIPHER_CTX_cleanup(&ctx);
2381         p = sdec;
2382
2383         sess = d2i_SSL_SESSION(NULL, &p, slen);
2384         OPENSSL_free(sdec);
2385         if (sess)
2386                 {
2387                 /* The session ID, if non-empty, is used by some clients to
2388                  * detect that the ticket has been accepted. So we copy it to
2389                  * the session structure. If it is empty set length to zero
2390                  * as required by standard.
2391                  */
2392                 if (sesslen)
2393                         memcpy(sess->session_id, sess_id, sesslen);
2394                 sess->session_id_length = sesslen;
2395                 *psess = sess;
2396                 if (renew_ticket)
2397                         return 4;
2398                 else
2399                         return 3;
2400                 }
2401         ERR_clear_error();
2402         /* For session parse failure, indicate that we need to send a new
2403          * ticket. */
2404         return 2;
2405         }
2406
2407 /* Tables to translate from NIDs to TLS v1.2 ids */
2408
2409 typedef struct
2410         {
2411         int nid;
2412         int id;
2413         } tls12_lookup;
2414
2415 static tls12_lookup tls12_md[] = {
2416 #ifndef OPENSSL_NO_MD5
2417         {NID_md5, TLSEXT_hash_md5},
2418 #endif
2419 #ifndef OPENSSL_NO_SHA
2420         {NID_sha1, TLSEXT_hash_sha1},
2421 #endif
2422 #ifndef OPENSSL_NO_SHA256
2423         {NID_sha224, TLSEXT_hash_sha224},
2424         {NID_sha256, TLSEXT_hash_sha256},
2425 #endif
2426 #ifndef OPENSSL_NO_SHA512
2427         {NID_sha384, TLSEXT_hash_sha384},
2428         {NID_sha512, TLSEXT_hash_sha512}
2429 #endif
2430 };
2431
2432 static tls12_lookup tls12_sig[] = {
2433 #ifndef OPENSSL_NO_RSA
2434         {EVP_PKEY_RSA, TLSEXT_signature_rsa},
2435 #endif
2436 #ifndef OPENSSL_NO_DSA
2437         {EVP_PKEY_DSA, TLSEXT_signature_dsa},
2438 #endif
2439 #ifndef OPENSSL_NO_ECDSA
2440         {EVP_PKEY_EC, TLSEXT_signature_ecdsa}
2441 #endif
2442 };
2443
2444 static int tls12_find_id(int nid, tls12_lookup *table, size_t tlen)
2445         {
2446         size_t i;
2447         for (i = 0; i < tlen; i++)
2448                 {
2449                 if (table[i].nid == nid)
2450                         return table[i].id;
2451                 }
2452         return -1;
2453         }
2454 #if 0
2455 static int tls12_find_nid(int id, tls12_lookup *table, size_t tlen)
2456         {
2457         size_t i;
2458         for (i = 0; i < tlen; i++)
2459                 {
2460                 if (table[i].id == id)
2461                         return table[i].nid;
2462                 }
2463         return -1;
2464         }
2465 #endif
2466
2467 int tls12_get_sigandhash(unsigned char *p, const EVP_PKEY *pk, const EVP_MD *md)
2468         {
2469         int sig_id, md_id;
2470         if (!md)
2471                 return 0;
2472         md_id = tls12_find_id(EVP_MD_type(md), tls12_md,
2473                                 sizeof(tls12_md)/sizeof(tls12_lookup));
2474         if (md_id == -1)
2475                 return 0;
2476         sig_id = tls12_get_sigid(pk);
2477         if (sig_id == -1)
2478                 return 0;
2479         p[0] = (unsigned char)md_id;
2480         p[1] = (unsigned char)sig_id;
2481         return 1;
2482         }
2483
2484 int tls12_get_sigid(const EVP_PKEY *pk)
2485         {
2486         return tls12_find_id(pk->type, tls12_sig,
2487                                 sizeof(tls12_sig)/sizeof(tls12_lookup));
2488         }
2489
2490 const EVP_MD *tls12_get_hash(unsigned char hash_alg)
2491         {
2492         switch(hash_alg)
2493                 {
2494 #ifndef OPENSSL_NO_SHA
2495                 case TLSEXT_hash_sha1:
2496                 return EVP_sha1();
2497 #endif
2498 #ifndef OPENSSL_NO_SHA256
2499                 case TLSEXT_hash_sha224:
2500                 return EVP_sha224();
2501
2502                 case TLSEXT_hash_sha256:
2503                 return EVP_sha256();
2504 #endif
2505 #ifndef OPENSSL_NO_SHA512
2506                 case TLSEXT_hash_sha384:
2507                 return EVP_sha384();
2508
2509                 case TLSEXT_hash_sha512:
2510                 return EVP_sha512();
2511 #endif
2512                 default:
2513                 return NULL;
2514
2515                 }
2516         }
2517
2518 /* Set preferred digest for each key type */
2519
2520 int tls1_process_sigalgs(SSL *s, const unsigned char *data, int dsize)
2521         {
2522         int i, idx;
2523         const EVP_MD *md;
2524         CERT *c = s->cert;
2525         /* Extension ignored for TLS versions below 1.2 */
2526         if (TLS1_get_version(s) < TLS1_2_VERSION)
2527                 return 1;
2528         /* Should never happen */
2529         if (!c)
2530                 return 0;
2531
2532         c->pkeys[SSL_PKEY_DSA_SIGN].digest = NULL;
2533         c->pkeys[SSL_PKEY_RSA_SIGN].digest = NULL;
2534         c->pkeys[SSL_PKEY_RSA_ENC].digest = NULL;
2535         c->pkeys[SSL_PKEY_ECC].digest = NULL;
2536
2537         for (i = 0; i < dsize; i += 2)
2538                 {
2539                 unsigned char hash_alg = data[i], sig_alg = data[i+1];
2540
2541                 switch(sig_alg)
2542                         {
2543 #ifndef OPENSSL_NO_RSA
2544                         case TLSEXT_signature_rsa:
2545                         idx = SSL_PKEY_RSA_SIGN;
2546                         break;
2547 #endif
2548 #ifndef OPENSSL_NO_DSA
2549                         case TLSEXT_signature_dsa:
2550                         idx = SSL_PKEY_DSA_SIGN;
2551                         break;
2552 #endif
2553 #ifndef OPENSSL_NO_ECDSA
2554                         case TLSEXT_signature_ecdsa:
2555                         idx = SSL_PKEY_ECC;
2556                         break;
2557 #endif
2558                         default:
2559                         continue;
2560                         }
2561
2562                 if (c->pkeys[idx].digest == NULL)
2563                         {
2564                         md = tls12_get_hash(hash_alg);
2565                         if (md)
2566                                 {
2567                                 c->pkeys[idx].digest = md;
2568                                 if (idx == SSL_PKEY_RSA_SIGN)
2569                                         c->pkeys[SSL_PKEY_RSA_ENC].digest = md;
2570                                 }
2571                         }
2572
2573                 }
2574
2575
2576         /* Set any remaining keys to default values. NOTE: if alg is not
2577          * supported it stays as NULL.
2578          */
2579 #ifndef OPENSSL_NO_DSA
2580         if (!c->pkeys[SSL_PKEY_DSA_SIGN].digest)
2581                 c->pkeys[SSL_PKEY_DSA_SIGN].digest = EVP_sha1();
2582 #endif
2583 #ifndef OPENSSL_NO_RSA
2584         if (!c->pkeys[SSL_PKEY_RSA_SIGN].digest)
2585                 {
2586                 c->pkeys[SSL_PKEY_RSA_SIGN].digest = EVP_sha1();
2587                 c->pkeys[SSL_PKEY_RSA_ENC].digest = EVP_sha1();
2588                 }
2589 #endif
2590 #ifndef OPENSSL_NO_ECDSA
2591         if (!c->pkeys[SSL_PKEY_ECC].digest)
2592                 c->pkeys[SSL_PKEY_ECC].digest = EVP_sha1();
2593 #endif
2594         return 1;
2595         }
2596
2597 #endif
2598
2599 #ifndef OPENSSL_NO_HEARTBEATS
2600 int
2601 tls1_process_heartbeat(SSL *s)
2602         {
2603         unsigned char *p = &s->s3->rrec.data[0], *pl;
2604         unsigned short hbtype;
2605         unsigned int payload;
2606         unsigned int padding = 16; /* Use minimum padding */
2607
2608         if (s->msg_callback)
2609                 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
2610                         &s->s3->rrec.data[0], s->s3->rrec.length,
2611                         s, s->msg_callback_arg);
2612
2613         /* Read type and payload length first */
2614         if (1 + 2 + 16 > s->s3->rrec.length)
2615                 return 0; /* silently discard */
2616         hbtype = *p++;
2617         n2s(p, payload);
2618         if (1 + 2 + payload + 16 > s->s3->rrec.length)
2619                 return 0; /* silently discard per RFC 6520 sec. 4 */
2620         pl = p;
2621
2622         if (hbtype == TLS1_HB_REQUEST)
2623                 {
2624                 unsigned char *buffer, *bp;
2625                 int r;
2626
2627                 /* Allocate memory for the response, size is 1 bytes
2628                  * message type, plus 2 bytes payload length, plus
2629                  * payload, plus padding
2630                  */
2631                 buffer = OPENSSL_malloc(1 + 2 + payload + padding);
2632                 bp = buffer;
2633
2634                 /* Enter response type, length and copy payload */
2635                 *bp++ = TLS1_HB_RESPONSE;
2636                 s2n(payload, bp);
2637                 memcpy(bp, pl, payload);
2638                 bp += payload;
2639                 /* Random padding */
2640                 RAND_pseudo_bytes(bp, padding);
2641
2642                 r = ssl3_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, 3 + payload + padding);
2643
2644                 if (r >= 0 && s->msg_callback)
2645                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
2646                                 buffer, 3 + payload + padding,
2647                                 s, s->msg_callback_arg);
2648
2649                 OPENSSL_free(buffer);
2650
2651                 if (r < 0)
2652                         return r;
2653                 }
2654         else if (hbtype == TLS1_HB_RESPONSE)
2655                 {
2656                 unsigned int seq;
2657
2658                 /* We only send sequence numbers (2 bytes unsigned int),
2659                  * and 16 random bytes, so we just try to read the
2660                  * sequence number */
2661                 n2s(pl, seq);
2662
2663                 if (payload == 18 && seq == s->tlsext_hb_seq)
2664                         {
2665                         s->tlsext_hb_seq++;
2666                         s->tlsext_hb_pending = 0;
2667                         }
2668                 }
2669
2670         return 0;
2671         }
2672
2673 int
2674 tls1_heartbeat(SSL *s)
2675         {
2676         unsigned char *buf, *p;
2677         int ret;
2678         unsigned int payload = 18; /* Sequence number + random bytes */
2679         unsigned int padding = 16; /* Use minimum padding */
2680
2681         /* Only send if peer supports and accepts HB requests... */
2682         if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
2683             s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
2684                 {
2685                 SSLerr(SSL_F_TLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
2686                 return -1;
2687                 }
2688
2689         /* ...and there is none in flight yet... */
2690         if (s->tlsext_hb_pending)
2691                 {
2692                 SSLerr(SSL_F_TLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
2693                 return -1;
2694                 }
2695
2696         /* ...and no handshake in progress. */
2697         if (SSL_in_init(s) || s->in_handshake)
2698                 {
2699                 SSLerr(SSL_F_TLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
2700                 return -1;
2701                 }
2702
2703         /* Check if padding is too long, payload and padding
2704          * must not exceed 2^14 - 3 = 16381 bytes in total.
2705          */
2706         OPENSSL_assert(payload + padding <= 16381);
2707
2708         /* Create HeartBeat message, we just use a sequence number
2709          * as payload to distuingish different messages and add
2710          * some random stuff.
2711          *  - Message Type, 1 byte
2712          *  - Payload Length, 2 bytes (unsigned int)
2713          *  - Payload, the sequence number (2 bytes uint)
2714          *  - Payload, random bytes (16 bytes uint)
2715          *  - Padding
2716          */
2717         buf = OPENSSL_malloc(1 + 2 + payload + padding);
2718         p = buf;
2719         /* Message Type */
2720         *p++ = TLS1_HB_REQUEST;
2721         /* Payload length (18 bytes here) */
2722         s2n(payload, p);
2723         /* Sequence number */
2724         s2n(s->tlsext_hb_seq, p);
2725         /* 16 random bytes */
2726         RAND_pseudo_bytes(p, 16);
2727         p += 16;
2728         /* Random padding */
2729         RAND_pseudo_bytes(p, padding);
2730
2731         ret = ssl3_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
2732         if (ret >= 0)
2733                 {
2734                 if (s->msg_callback)
2735                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
2736                                 buf, 3 + payload + padding,
2737                                 s, s->msg_callback_arg);
2738
2739                 s->tlsext_hb_pending = 1;
2740                 }
2741
2742         OPENSSL_free(buf);
2743
2744         return ret;
2745         }
2746 #endif