src/third_party/boringssl/src/ssl/t1_lib.c

   1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   2  * All rights reserved.
   3  *
   4  * This package is an SSL implementation written
   5  * by Eric Young (eay@cryptsoft.com).
   6  * The implementation was written so as to conform with Netscapes SSL.
   7  *
   8  * This library is free for commercial and non-commercial use as long as
   9  * the following conditions are aheared to.  The following conditions
  10  * apply to all code found in this distribution, be it the RC4, RSA,
  11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  12  * included with this distribution is covered by the same copyright terms
  13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  14  *
  15  * Copyright remains Eric Young's, and as such any Copyright notices in
  16  * the code are not to be removed.
  17  * If this package is used in a product, Eric Young should be given attribution
  18  * as the author of the parts of the library used.
  19  * This can be in the form of a textual message at program startup or
  20  * in documentation (online or textual) provided with the package.
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  * 1. Redistributions of source code must retain the copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  * 2. Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in the
  29  *    documentation and/or other materials provided with the distribution.
  30  * 3. All advertising materials mentioning features or use of this software
  31  *    must display the following acknowledgement:
  32  *    "This product includes cryptographic software written by
  33  *     Eric Young (eay@cryptsoft.com)"
  34  *    The word 'cryptographic' can be left out if the rouines from the library
  35  *    being used are not cryptographic related :-).
  36  * 4. If you include any Windows specific code (or a derivative thereof) from
  37  *    the apps directory (application code) you must include an acknowledgement:
  38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  50  * SUCH DAMAGE.
  51  *
  52  * The licence and distribution terms for any publically available version or
  53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  54  * copied and put under another distribution licence
  55  * [including the GNU Public Licence.]
  56  */
  57 /* ====================================================================
  58  * Copyright (c) 1998-2007 The OpenSSL Project.  All rights reserved.
  59  *
  60  * Redistribution and use in source and binary forms, with or without
  61  * modification, are permitted provided that the following conditions
  62  * are met:
  63  *
  64  * 1. Redistributions of source code must retain the above copyright
  65  *    notice, this list of conditions and the following disclaimer.
  66  *
  67  * 2. Redistributions in binary form must reproduce the above copyright
  68  *    notice, this list of conditions and the following disclaimer in
  69  *    the documentation and/or other materials provided with the
  70  *    distribution.
  71  *
  72  * 3. All advertising materials mentioning features or use of this
  73  *    software must display the following acknowledgment:
  74  *    "This product includes software developed by the OpenSSL Project
  75  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  76  *
  77  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  78  *    endorse or promote products derived from this software without
  79  *    prior written permission. For written permission, please contact
  80  *    openssl-core@openssl.org.
  81  *
  82  * 5. Products derived from this software may not be called "OpenSSL"
  83  *    nor may "OpenSSL" appear in their names without prior written
  84  *    permission of the OpenSSL Project.
  85  *
  86  * 6. Redistributions of any form whatsoever must retain the following
  87  *    acknowledgment:
  88  *    "This product includes software developed by the OpenSSL Project
  89  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  90  *
  91  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  92  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  93  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  94  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  95  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  96  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  97  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  98  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  99  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 100  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 101  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 102  * OF THE POSSIBILITY OF SUCH DAMAGE.
 103  * ====================================================================
 104  *
 105  * This product includes cryptographic software written by Eric Young
 106  * (eay@cryptsoft.com).  This product includes software written by Tim
 107  * Hudson (tjh@cryptsoft.com). */
 108
 109 #include <stdio.h>
 110 #include <stdlib.h>
 111 #include <assert.h>
 112
 113 #include <openssl/bytestring.h>
 114 #include <openssl/evp.h>
 115 #include <openssl/hmac.h>
 116 #include <openssl/mem.h>
 117 #include <openssl/obj.h>
 118 #include <openssl/rand.h>
 119
 120 #include "ssl_locl.h"
 121 static int tls_decrypt_ticket(SSL *s, const unsigned char *tick, int ticklen,
 122                                 const unsigned char *sess_id, int sesslen,
 123                                 SSL_SESSION **psess);
 124 static int ssl_check_clienthello_tlsext_early(SSL *s);
 125 int ssl_check_serverhello_tlsext(SSL *s);
 126
 127 SSL3_ENC_METHOD TLSv1_enc_data={
 128         tls1_enc,
 129         tls1_mac,
 130         tls1_setup_key_block,
 131         tls1_generate_master_secret,
 132         tls1_change_cipher_state,
 133         tls1_final_finish_mac,
 134         TLS1_FINISH_MAC_LENGTH,
 135         tls1_cert_verify_mac,
 136         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
 137         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
 138         tls1_alert_code,
 139         tls1_export_keying_material,
 140         0,
 141         SSL3_HM_HEADER_LENGTH,
 142         ssl3_set_handshake_header,
 143         ssl3_handshake_write
 144         };
 145
 146 SSL3_ENC_METHOD TLSv1_1_enc_data={
 147         tls1_enc,
 148         tls1_mac,
 149         tls1_setup_key_block,
 150         tls1_generate_master_secret,
 151         tls1_change_cipher_state,
 152         tls1_final_finish_mac,
 153         TLS1_FINISH_MAC_LENGTH,
 154         tls1_cert_verify_mac,
 155         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
 156         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
 157         tls1_alert_code,
 158         tls1_export_keying_material,
 159         SSL_ENC_FLAG_EXPLICIT_IV,
 160         SSL3_HM_HEADER_LENGTH,
 161         ssl3_set_handshake_header,
 162         ssl3_handshake_write
 163         };
 164
 165 SSL3_ENC_METHOD TLSv1_2_enc_data={
 166         tls1_enc,
 167         tls1_mac,
 168         tls1_setup_key_block,
 169         tls1_generate_master_secret,
 170         tls1_change_cipher_state,
 171         tls1_final_finish_mac,
 172         TLS1_FINISH_MAC_LENGTH,
 173         tls1_cert_verify_mac,
 174         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
 175         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
 176         tls1_alert_code,
 177         tls1_export_keying_material,
 178         SSL_ENC_FLAG_EXPLICIT_IV|SSL_ENC_FLAG_SIGALGS|SSL_ENC_FLAG_SHA256_PRF
 179                 |SSL_ENC_FLAG_TLS1_2_CIPHERS,
 180         SSL3_HM_HEADER_LENGTH,
 181         ssl3_set_handshake_header,
 182         ssl3_handshake_write
 183         };
 184
 185 long tls1_default_timeout(void)
 186         {
 187         /* 2 hours, the 24 hours mentioned in the TLSv1 spec
 188          * is way too long for http, the cache would over fill */
 189         return(60*60*2);
 190         }
 191
 192 int tls1_new(SSL *s)
 193         {
 194         if (!ssl3_new(s)) return(0);
 195         s->method->ssl_clear(s);
 196         return(1);
 197         }
 198
 199 void tls1_free(SSL *s)
 200         {
 201         if (s->tlsext_session_ticket)
 202                 {
 203                 OPENSSL_free(s->tlsext_session_ticket);
 204                 }
 205         ssl3_free(s);
 206         }
 207
 208 void tls1_clear(SSL *s)
 209         {
 210         ssl3_clear(s);
 211         s->version = s->method->version;
 212         }
 213
 214 static int compare_uint16_t(const void *p1, const void *p2)
 215         {
 216         uint16_t u1 = *((const uint16_t*)p1);
 217         uint16_t u2 = *((const uint16_t*)p2);
 218         if (u1 < u2)
 219                 {
 220                 return -1;
 221                 }
 222         else if (u1 > u2)
 223                 {
 224                 return 1;
 225                 }
 226         else
 227                 {
 228                 return 0;
 229                 }
 230         }
 231
 232 /* Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be more
 233  * than one extension of the same type in a ClientHello or ServerHello. This
 234  * function does an initial scan over the extensions block to filter those
 235  * out. */
 236 static int tls1_check_duplicate_extensions(const CBS *cbs)
 237         {
 238         CBS extensions = *cbs;
 239         size_t num_extensions = 0, i = 0;
 240         uint16_t *extension_types = NULL;
 241         int ret = 0;
 242
 243         /* First pass: count the extensions. */
 244         while (CBS_len(&extensions) > 0)
 245                 {
 246                 uint16_t type;
 247                 CBS extension;
 248
 249                 if (!CBS_get_u16(&extensions, &type) ||
 250                         !CBS_get_u16_length_prefixed(&extensions, &extension))
 251                         {
 252                         goto done;
 253                         }
 254
 255                 num_extensions++;
 256                 }
 257
 258         if (num_extensions == 0)
 259                 {
 260                 return 1;
 261                 }
 262
 263         extension_types = (uint16_t*)OPENSSL_malloc(sizeof(uint16_t) * num_extensions);
 264         if (extension_types == NULL)
 265                 {
 266                 OPENSSL_PUT_ERROR(SSL, tls1_check_duplicate_extensions, ERR_R_MALLOC_FAILURE);
 267                 goto done;
 268                 }
 269
 270         /* Second pass: gather the extension types. */
 271         extensions = *cbs;
 272         for (i = 0; i < num_extensions; i++)
 273                 {
 274                 CBS extension;
 275
 276                 if (!CBS_get_u16(&extensions, &extension_types[i]) ||
 277                         !CBS_get_u16_length_prefixed(&extensions, &extension))
 278                         {
 279                         /* This should not happen. */
 280                         goto done;
 281                         }
 282                 }
 283         assert(CBS_len(&extensions) == 0);
 284
 285         /* Sort the extensions and make sure there are no duplicates. */
 286         qsort(extension_types, num_extensions, sizeof(uint16_t), compare_uint16_t);
 287         for (i = 1; i < num_extensions; i++)
 288                 {
 289                 if (extension_types[i-1] == extension_types[i])
 290                         {
 291                         goto done;
 292                         }
 293                 }
 294
 295         ret = 1;
 296 done:
 297         if (extension_types)
 298                 OPENSSL_free(extension_types);
 299         return ret;
 300         }
 301
 302 char ssl_early_callback_init(struct ssl_early_callback_ctx *ctx)
 303         {
 304         CBS client_hello, session_id, cipher_suites, compression_methods, extensions;
 305
 306         CBS_init(&client_hello, ctx->client_hello, ctx->client_hello_len);
 307
 308         /* Skip client version. */
 309         if (!CBS_skip(&client_hello, 2))
 310                 return 0;
 311
 312         /* Skip client nonce. */
 313         if (!CBS_skip(&client_hello, 32))
 314                 return 0;
 315
 316         /* Extract session_id. */
 317         if (!CBS_get_u8_length_prefixed(&client_hello, &session_id))
 318                 return 0;
 319         ctx->session_id = CBS_data(&session_id);
 320         ctx->session_id_len = CBS_len(&session_id);
 321
 322         /* Skip past DTLS cookie */
 323         if (ctx->ssl->version == DTLS1_VERSION || ctx->ssl->version == DTLS1_BAD_VER)
 324                 {
 325                 CBS cookie;
 326
 327                 if (!CBS_get_u8_length_prefixed(&client_hello, &cookie))
 328                         return 0;
 329                 }
 330
 331         /* Extract cipher_suites. */
 332         if (!CBS_get_u16_length_prefixed(&client_hello, &cipher_suites) ||
 333                 CBS_len(&cipher_suites) < 2 ||
 334                 (CBS_len(&cipher_suites) & 1) != 0)
 335                 return 0;
 336         ctx->cipher_suites = CBS_data(&cipher_suites);
 337         ctx->cipher_suites_len = CBS_len(&cipher_suites);
 338
 339         /* Extract compression_methods. */
 340         if (!CBS_get_u8_length_prefixed(&client_hello, &compression_methods) ||
 341                 CBS_len(&compression_methods) < 1)
 342                 return 0;
 343         ctx->compression_methods = CBS_data(&compression_methods);
 344         ctx->compression_methods_len = CBS_len(&compression_methods);
 345
 346         /* If the ClientHello ends here then it's valid, but doesn't have any
 347          * extensions. (E.g. SSLv3.) */
 348         if (CBS_len(&client_hello) == 0)
 349                 {
 350                 ctx->extensions = NULL;
 351                 ctx->extensions_len = 0;
 352                 return 1;
 353                 }
 354
 355         /* Extract extensions and check it is valid. */
 356         if (!CBS_get_u16_length_prefixed(&client_hello, &extensions) ||
 357                 !tls1_check_duplicate_extensions(&extensions) ||
 358                 CBS_len(&client_hello) != 0)
 359                 return 0;
 360         ctx->extensions = CBS_data(&extensions);
 361         ctx->extensions_len = CBS_len(&extensions);
 362
 363         return 1;
 364         }
 365
 366 char
 367 SSL_early_callback_ctx_extension_get(const struct ssl_early_callback_ctx *ctx,
 368                                      uint16_t extension_type,
 369                                      const unsigned char **out_data,
 370                                      size_t *out_len)
 371         {
 372         CBS extensions;
 373
 374         CBS_init(&extensions, ctx->extensions, ctx->extensions_len);
 375
 376         while (CBS_len(&extensions) != 0)
 377                 {
 378                 uint16_t type;
 379                 CBS extension;
 380
 381                 /* Decode the next extension. */
 382                 if (!CBS_get_u16(&extensions, &type) ||
 383                         !CBS_get_u16_length_prefixed(&extensions, &extension))
 384                         return 0;
 385
 386                 if (type == extension_type)
 387                         {
 388                         *out_data = CBS_data(&extension);
 389                         *out_len = CBS_len(&extension);
 390                         return 1;
 391                         }
 392                 }
 393
 394         return 0;
 395         }
 396
 397 #ifndef OPENSSL_NO_EC
 398
 399 static int nid_list[] =
 400         {
 401                 NID_sect163k1, /* sect163k1 (1) */
 402                 NID_sect163r1, /* sect163r1 (2) */
 403                 NID_sect163r2, /* sect163r2 (3) */
 404                 NID_sect193r1, /* sect193r1 (4) */
 405                 NID_sect193r2, /* sect193r2 (5) */
 406                 NID_sect233k1, /* sect233k1 (6) */
 407                 NID_sect233r1, /* sect233r1 (7) */
 408                 NID_sect239k1, /* sect239k1 (8) */
 409                 NID_sect283k1, /* sect283k1 (9) */
 410                 NID_sect283r1, /* sect283r1 (10) */
 411                 NID_sect409k1, /* sect409k1 (11) */
 412                 NID_sect409r1, /* sect409r1 (12) */
 413                 NID_sect571k1, /* sect571k1 (13) */
 414                 NID_sect571r1, /* sect571r1 (14) */
 415                 NID_secp160k1, /* secp160k1 (15) */
 416                 NID_secp160r1, /* secp160r1 (16) */
 417                 NID_secp160r2, /* secp160r2 (17) */
 418                 NID_secp192k1, /* secp192k1 (18) */
 419                 NID_X9_62_prime192v1, /* secp192r1 (19) */
 420                 NID_secp224k1, /* secp224k1 (20) */
 421                 NID_secp224r1, /* secp224r1 (21) */
 422                 NID_secp256k1, /* secp256k1 (22) */
 423                 NID_X9_62_prime256v1, /* secp256r1 (23) */
 424                 NID_secp384r1, /* secp384r1 (24) */
 425                 NID_secp521r1,  /* secp521r1 (25) */
 426                 NID_brainpoolP256r1,  /* brainpoolP256r1 (26) */
 427                 NID_brainpoolP384r1,  /* brainpoolP384r1 (27) */
 428                 NID_brainpoolP512r1  /* brainpool512r1 (28) */
 429         };
 430
 431 static const uint8_t ecformats_default[] =
 432         {
 433         TLSEXT_ECPOINTFORMAT_uncompressed,
 434         };
 435
 436 static const uint16_t eccurves_default[] =
 437         {
 438                 23, /* secp256r1 (23) */
 439                 24, /* secp384r1 (24) */
 440                 25, /* secp521r1 (25) */
 441         };
 442
 443 static const uint16_t suiteb_curves[] =
 444         {
 445                 TLSEXT_curve_P_256,
 446                 TLSEXT_curve_P_384,
 447         };
 448
 449 int tls1_ec_curve_id2nid(uint16_t curve_id)
 450         {
 451         /* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */
 452         if (curve_id < 1 || curve_id > sizeof(nid_list)/sizeof(nid_list[0]))
 453                 return OBJ_undef;
 454         return nid_list[curve_id-1];
 455         }
 456
 457 uint16_t tls1_ec_nid2curve_id(int nid)
 458         {
 459         size_t i;
 460         for (i = 0; i < sizeof(nid_list)/sizeof(nid_list[0]); i++)
 461                 {
 462                 /* nid_list[i] stores the NID corresponding to curve ID i+1. */
 463                 if (nid == nid_list[i])
 464                         return i + 1;
 465                 }
 466         /* Use 0 for non-existent curve ID. Note: this assumes that curve ID 0
 467          * will never be allocated. */
 468         return 0;
 469         }
 470
 471 /* tls1_get_curvelist sets |*out_curve_ids| and |*out_curve_ids_len| to the list
 472  * of allowed curve IDs. If |get_client_curves| is non-zero, return the client
 473  * curve list. Otherwise, return the preferred list. */
 474 static void tls1_get_curvelist(SSL *s, int get_client_curves,
 475         const uint16_t **out_curve_ids, size_t *out_curve_ids_len)
 476         {
 477         if (get_client_curves)
 478                 {
 479                 *out_curve_ids = s->session->tlsext_ellipticcurvelist;
 480                 *out_curve_ids_len = s->session->tlsext_ellipticcurvelist_length;
 481                 return;
 482                 }
 483         /* For Suite B mode only include P-256, P-384 */
 484         switch (tls1_suiteb(s))
 485                 {
 486         case SSL_CERT_FLAG_SUITEB_128_LOS:
 487                 *out_curve_ids = suiteb_curves;
 488                 *out_curve_ids_len = sizeof(suiteb_curves) / sizeof(suiteb_curves[0]);
 489                 break;
 490
 491         case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
 492                 *out_curve_ids = suiteb_curves;
 493                 *out_curve_ids_len = 1;
 494                 break;
 495
 496         case SSL_CERT_FLAG_SUITEB_192_LOS:
 497                 *out_curve_ids = suiteb_curves + 1;
 498                 *out_curve_ids_len = 1;
 499                 break;
 500         default:
 501                 *out_curve_ids = s->tlsext_ellipticcurvelist;
 502                 *out_curve_ids_len = s->tlsext_ellipticcurvelist_length;
 503                 }
 504         if (!*out_curve_ids)
 505                 {
 506                 *out_curve_ids = eccurves_default;
 507                 *out_curve_ids_len = sizeof(eccurves_default) / sizeof(eccurves_default[0]);
 508                 }
 509         }
 510
 511 int tls1_check_curve(SSL *s, CBS *cbs, uint16_t *out_curve_id)
 512         {
 513         uint8_t curve_type;
 514         uint16_t curve_id;
 515         const uint16_t *curves;
 516         size_t curves_len, i;
 517
 518         /* Only support named curves. */
 519         if (!CBS_get_u8(cbs, &curve_type) ||
 520                 curve_type != NAMED_CURVE_TYPE ||
 521                 !CBS_get_u16(cbs, &curve_id))
 522                 return 0;
 523
 524         /* Check curve matches Suite B preferences */
 525         if (tls1_suiteb(s))
 526                 {
 527                 unsigned long cid = s->s3->tmp.new_cipher->id;
 528                 if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
 529                         {
 530                         if (curve_id != TLSEXT_curve_P_256)
 531                                 return 0;
 532                         }
 533                 else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
 534                         {
 535                         if (curve_id != TLSEXT_curve_P_384)
 536                                 return 0;
 537                         }
 538                 else    /* Should never happen */
 539                         return 0;
 540                 }
 541         tls1_get_curvelist(s, 0, &curves, &curves_len);
 542         for (i = 0; i < curves_len; i++)
 543                 {
 544                 if (curve_id == curves[i])
 545                         {
 546                         *out_curve_id = curve_id;
 547                         return 1;
 548                         }
 549                 }
 550         return 0;
 551         }
 552
 553 int tls1_get_shared_curve(SSL *s)
 554         {
 555         const uint16_t *pref, *supp;
 556         size_t preflen, supplen, i, j;
 557
 558         /* Can't do anything on client side */
 559         if (s->server == 0)
 560                 return NID_undef;
 561
 562         if (tls1_suiteb(s))
 563                 {
 564                 /* For Suite B ciphersuite determines curve: we
 565                  * already know these are acceptable due to previous
 566                  * checks.
 567                  */
 568                 unsigned long cid = s->s3->tmp.new_cipher->id;
 569                 if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
 570                         return NID_X9_62_prime256v1; /* P-256 */
 571                 if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
 572                         return NID_secp384r1; /* P-384 */
 573                 /* Should never happen */
 574                 return NID_undef;
 575                 }
 576
 577         /* If not Suite B just return first preference shared curve */
 578         tls1_get_curvelist(s, !!(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE),
 579                                 &supp, &supplen);
 580         tls1_get_curvelist(s, !(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE),
 581                                 &pref, &preflen);
 582         for (i = 0; i < preflen; i++)
 583                 {
 584                 for (j = 0; j < supplen; j++)
 585                         {
 586                         if (pref[i] == supp[j])
 587                                 return tls1_ec_curve_id2nid(pref[i]);
 588                         }
 589                 }
 590         return NID_undef;
 591         }
 592
 593 /* NOTE: tls1_ec_curve_id2nid and tls1_set_curves assume that
 594  *
 595  * (a) 0 is not a valid curve ID.
 596  *
 597  * (b) The largest curve ID is 31.
 598  *
 599  * Those implementations must be revised before adding support for curve IDs
 600  * that break these assumptions. */
 601 OPENSSL_COMPILE_ASSERT(
 602         (sizeof(nid_list) / sizeof(nid_list[0])) < 32, small_curve_ids);
 603
 604 int tls1_set_curves(uint16_t **out_curve_ids, size_t *out_curve_ids_len,
 605         const int *curves, size_t ncurves)
 606         {
 607         uint16_t *curve_ids;
 608         size_t i;
 609         /* Bitmap of curves included to detect duplicates: only works
 610          * while curve ids < 32
 611          */
 612         uint32_t dup_list = 0;
 613         curve_ids = (uint16_t*)OPENSSL_malloc(ncurves * sizeof(uint16_t));
 614         if (!curve_ids)
 615                 return 0;
 616         for (i = 0; i < ncurves; i++)
 617                 {
 618                 uint32_t idmask;
 619                 uint16_t id;
 620                 id = tls1_ec_nid2curve_id(curves[i]);
 621                 idmask = ((uint32_t)1) << id;
 622                 if (!id || (dup_list & idmask))
 623                         {
 624                         OPENSSL_free(curve_ids);
 625                         return 0;
 626                         }
 627                 dup_list |= idmask;
 628                 curve_ids[i] = id;
 629                 }
 630         if (*out_curve_ids)
 631                 OPENSSL_free(*out_curve_ids);
 632         *out_curve_ids = curve_ids;
 633         *out_curve_ids_len = ncurves;
 634         return 1;
 635         }
 636
 637 /* tls1_curve_params_from_ec_key sets |*out_curve_id| and |*out_comp_id| to the
 638  * TLS curve ID and point format, respectively, for |ec|. It returns one on
 639  * success and zero on failure. */
 640 static int tls1_curve_params_from_ec_key(uint16_t *out_curve_id, uint8_t *out_comp_id, EC_KEY *ec)
 641         {
 642         int nid;
 643         uint16_t id;
 644         const EC_GROUP *grp;
 645         if (!ec)
 646                 return 0;
 647
 648         grp = EC_KEY_get0_group(ec);
 649         if (!grp)
 650                 return 0;
 651
 652         /* Determine curve ID */
 653         nid = EC_GROUP_get_curve_name(grp);
 654         id = tls1_ec_nid2curve_id(nid);
 655         if (!id)
 656                 return 0;
 657
 658         /* Set the named curve ID. Arbitrary explicit curves are not
 659          * supported. */
 660         *out_curve_id = id;
 661
 662         if (out_comp_id)
 663                 {
 664                 if (EC_KEY_get0_public_key(ec) == NULL)
 665                         return 0;
 666                 if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_COMPRESSED)
 667                         *out_comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
 668                 else
 669                         *out_comp_id = TLSEXT_ECPOINTFORMAT_uncompressed;
 670                 }
 671         return 1;
 672         }
 673
 674 /* Check an EC key is compatible with extensions */
 675 static int tls1_check_ec_key(SSL *s,
 676         const uint16_t *curve_id, const uint8_t *comp_id)
 677         {
 678         const uint16_t *curves;
 679         size_t curves_len, i;
 680         int j;
 681         /* If point formats extension present check it, otherwise everything
 682          * is supported (see RFC4492).
 683          */
 684         if (comp_id && s->session->tlsext_ecpointformatlist)
 685                 {
 686                 uint8_t *p = s->session->tlsext_ecpointformatlist;
 687                 size_t plen = s->session->tlsext_ecpointformatlist_length;
 688                 for (i = 0; i < plen; i++)
 689                         {
 690                         if (*comp_id == p[i])
 691                                 break;
 692                         }
 693                 if (i == plen)
 694                         return 0;
 695                 }
 696         if (!curve_id)
 697                 return 1;
 698         /* Check curve is consistent with client and server preferences */
 699         for (j = 0; j <= 1; j++)
 700                 {
 701                 tls1_get_curvelist(s, j, &curves, &curves_len);
 702                 for (i = 0; i < curves_len; i++)
 703                         {
 704                         if (curves[i] == *curve_id)
 705                                 break;
 706                         }
 707                 if (i == curves_len)
 708                         return 0;
 709                 /* For clients can only check sent curve list */
 710                 if (!s->server)
 711                         return 1;
 712                 }
 713         return 1;
 714         }
 715
 716 static void tls1_get_formatlist(SSL *s, const unsigned char **pformats,
 717                                         size_t *pformatslen)
 718         {
 719         /* If we have a custom point format list use it otherwise
 720          * use default */
 721         if (s->tlsext_ecpointformatlist)
 722                 {
 723                 *pformats = s->tlsext_ecpointformatlist;
 724                 *pformatslen = s->tlsext_ecpointformatlist_length;
 725                 }
 726         else
 727                 {
 728                 *pformats = ecformats_default;
 729                 /* For Suite B we don't support char2 fields */
 730                 if (tls1_suiteb(s))
 731                         *pformatslen = sizeof(ecformats_default) - 1;
 732                 else
 733                         *pformatslen = sizeof(ecformats_default);
 734                 }
 735         }
 736
 737 /* Check cert parameters compatible with extensions: currently just checks
 738  * EC certificates have compatible curves and compression.
 739  */
 740 static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
 741         {
 742         uint8_t comp_id;
 743         uint16_t curve_id;
 744         EVP_PKEY *pkey;
 745         int rv;
 746         pkey = X509_get_pubkey(x);
 747         if (!pkey)
 748                 return 0;
 749         /* If not EC nothing to do */
 750         if (pkey->type != EVP_PKEY_EC)
 751                 {
 752                 EVP_PKEY_free(pkey);
 753                 return 1;
 754                 }
 755         rv = tls1_curve_params_from_ec_key(&curve_id, &comp_id, pkey->pkey.ec);
 756         EVP_PKEY_free(pkey);
 757         if (!rv)
 758                 return 0;
 759         /* Can't check curve_id for client certs as we don't have a
 760          * supported curves extension.
 761          */
 762         rv = tls1_check_ec_key(s, s->server ? &curve_id : NULL, &comp_id);
 763         if (!rv)
 764                 return 0;
 765         /* Special case for suite B. We *MUST* sign using SHA256+P-256 or
 766          * SHA384+P-384, adjust digest if necessary.
 767          */
 768         if (set_ee_md && tls1_suiteb(s))
 769                 {
 770                 int check_md;
 771                 size_t i;
 772                 CERT *c = s->cert;
 773                 /* Check to see we have necessary signing algorithm */
 774                 if (curve_id == TLSEXT_curve_P_256)
 775                         check_md = NID_ecdsa_with_SHA256;
 776                 else if (curve_id == TLSEXT_curve_P_384)
 777                         check_md = NID_ecdsa_with_SHA384;
 778                 else
 779                         return 0; /* Should never happen */
 780                 for (i = 0; i < c->shared_sigalgslen; i++)
 781                         if (check_md == c->shared_sigalgs[i].signandhash_nid)
 782                                 break;
 783                 if (i == c->shared_sigalgslen)
 784                         return 0;
 785                 if (set_ee_md == 2)
 786                         {
 787                         if (check_md == NID_ecdsa_with_SHA256)
 788                                 c->pkeys[SSL_PKEY_ECC].digest = EVP_sha256();
 789                         else
 790                                 c->pkeys[SSL_PKEY_ECC].digest = EVP_sha384();
 791                         }
 792                 }
 793         return rv;
 794         }
 795 /* Check EC temporary key is compatible with client extensions */
 796 int tls1_check_ec_tmp_key(SSL *s, unsigned long cid)
 797         {
 798         uint16_t curve_id;
 799         EC_KEY *ec = s->cert->ecdh_tmp;
 800 #ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
 801         /* Allow any curve: not just those peer supports */
 802         if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTOCOL)
 803                 return 1;
 804 #endif
 805         /* If Suite B, AES128 MUST use P-256 and AES256 MUST use P-384,
 806          * no other curves permitted.
 807          */
 808         if (tls1_suiteb(s))
 809                 {
 810                 /* Curve to check determined by ciphersuite */
 811                 if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
 812                         curve_id = TLSEXT_curve_P_256;
 813                 else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
 814                         curve_id = TLSEXT_curve_P_384;
 815                 else
 816                         return 0;
 817                 /* Check this curve is acceptable */
 818                 if (!tls1_check_ec_key(s, &curve_id, NULL))
 819                         return 0;
 820                 /* If auto or setting curve from callback assume OK */
 821                 if (s->cert->ecdh_tmp_auto || s->cert->ecdh_tmp_cb)
 822                         return 1;
 823                 /* Otherwise check curve is acceptable */
 824                 else
 825                         {
 826                         uint16_t curve_tmp;
 827                         if (!ec)
 828                                 return 0;
 829                         if (!tls1_curve_params_from_ec_key(&curve_tmp, NULL, ec))
 830                                 return 0;
 831                         if (curve_tmp == curve_id)
 832                                 return 1;
 833                         return 0;
 834                         }
 835
 836                 }
 837         if (s->cert->ecdh_tmp_auto)
 838                 {
 839                 /* Need a shared curve */
 840                 return tls1_get_shared_curve(s) != NID_undef;
 841                 }
 842         if (!ec)
 843                 {
 844                 if (s->cert->ecdh_tmp_cb)
 845                         return 1;
 846                 else
 847                         return 0;
 848                 }
 849         if (!tls1_curve_params_from_ec_key(&curve_id, NULL, ec))
 850                 return 0;
 851 /* Set this to allow use of invalid curves for testing */
 852 #if 0
 853         return 1;
 854 #else
 855         return tls1_check_ec_key(s, &curve_id, NULL);
 856 #endif
 857         }
 858
 859 #else
 860
 861 static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
 862         {
 863         return 1;
 864         }
 865
 866 #endif /* OPENSSL_NO_EC */
 867
 868
 869 /* List of supported signature algorithms and hashes. Should make this
 870  * customisable at some point, for now include everything we support.
 871  */
 872
 873 #define tlsext_sigalg_rsa(md) md, TLSEXT_signature_rsa,
 874
 875 #ifdef OPENSSL_NO_DSA
 876 #define tlsext_sigalg_dsa(md) /* */
 877 #else
 878 #define tlsext_sigalg_dsa(md) md, TLSEXT_signature_dsa,
 879 #endif
 880
 881 #ifdef OPENSSL_NO_ECDSA
 882 #define tlsext_sigalg_ecdsa(md) /* */
 883 #else
 884 #define tlsext_sigalg_ecdsa(md) md, TLSEXT_signature_ecdsa,
 885 #endif
 886
 887 #define tlsext_sigalg(md) \
 888                 tlsext_sigalg_rsa(md) \
 889                 tlsext_sigalg_dsa(md) \
 890                 tlsext_sigalg_ecdsa(md)
 891
 892 static unsigned char tls12_sigalgs[] = {
 893         tlsext_sigalg(TLSEXT_hash_sha512)
 894         tlsext_sigalg(TLSEXT_hash_sha384)
 895         tlsext_sigalg(TLSEXT_hash_sha256)
 896         tlsext_sigalg(TLSEXT_hash_sha224)
 897 #ifndef OPENSSL_NO_SHA
 898         tlsext_sigalg(TLSEXT_hash_sha1)
 899 #endif
 900 };
 901 #ifndef OPENSSL_NO_ECDSA
 902 static unsigned char suiteb_sigalgs[] = {
 903         tlsext_sigalg_ecdsa(TLSEXT_hash_sha256)
 904         tlsext_sigalg_ecdsa(TLSEXT_hash_sha384)
 905 };
 906 #endif
 907 size_t tls12_get_psigalgs(SSL *s, const unsigned char **psigs)
 908         {
 909         /* If Suite B mode use Suite B sigalgs only, ignore any other
 910          * preferences.
 911          */
 912 #ifndef OPENSSL_NO_EC
 913         switch (tls1_suiteb(s))
 914                 {
 915         case SSL_CERT_FLAG_SUITEB_128_LOS:
 916                 *psigs = suiteb_sigalgs;
 917                 return sizeof(suiteb_sigalgs);
 918
 919         case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
 920                 *psigs = suiteb_sigalgs;
 921                 return 2;
 922
 923         case SSL_CERT_FLAG_SUITEB_192_LOS:
 924                 *psigs = suiteb_sigalgs + 2;
 925                 return 2;
 926                 }
 927 #endif
 928         /* If server use client authentication sigalgs if not NULL */
 929         if (s->server && s->cert->client_sigalgs)
 930                 {
 931                 *psigs = s->cert->client_sigalgs;
 932                 return s->cert->client_sigalgslen;
 933                 }
 934         else if (s->cert->conf_sigalgs)
 935                 {
 936                 *psigs = s->cert->conf_sigalgs;
 937                 return s->cert->conf_sigalgslen;
 938                 }
 939         else
 940                 {
 941                 *psigs = tls12_sigalgs;
 942                 return sizeof(tls12_sigalgs);
 943                 }
 944         }
 945
 946 /* tls12_check_peer_sigalg parses a SignatureAndHashAlgorithm out of
 947  * |cbs|. It checks it is consistent with |s|'s sent supported
 948  * signature algorithms and, if so, writes the relevant digest into
 949  * |*out_md| and returns 1. Otherwise it returns 0 and writes an alert
 950  * into |*out_alert|.
 951  */
 952 int tls12_check_peer_sigalg(const EVP_MD **out_md, int *out_alert,
 953         SSL *s, CBS *cbs, EVP_PKEY *pkey)
 954         {
 955         const unsigned char *sent_sigs;
 956         size_t sent_sigslen, i;
 957         int sigalg = tls12_get_sigid(pkey);
 958         uint8_t hash, signature;
 959         /* Should never happen */
 960         if (sigalg == -1)
 961                 {
 962                 OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, ERR_R_INTERNAL_ERROR);
 963                 *out_alert = SSL_AD_INTERNAL_ERROR;
 964                 return 0;
 965                 }
 966         if (!CBS_get_u8(cbs, &hash) ||
 967                 !CBS_get_u8(cbs, &signature))
 968                 {
 969                 OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_DECODE_ERROR);
 970                 *out_alert = SSL_AD_DECODE_ERROR;
 971                 return 0;
 972                 }
 973         /* Check key type is consistent with signature */
 974         if (sigalg != signature)
 975                 {
 976                 OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_WRONG_SIGNATURE_TYPE);
 977                 *out_alert = SSL_AD_ILLEGAL_PARAMETER;
 978                 return 0;
 979                 }
 980 #ifndef OPENSSL_NO_EC
 981         if (pkey->type == EVP_PKEY_EC)
 982                 {
 983                 uint16_t curve_id;
 984                 uint8_t comp_id;
 985                 /* Check compression and curve matches extensions */
 986                 if (!tls1_curve_params_from_ec_key(&curve_id, &comp_id, pkey->pkey.ec))
 987                         {
 988                         *out_alert = SSL_AD_INTERNAL_ERROR;
 989                         return 0;
 990                         }
 991                 if (!s->server && !tls1_check_ec_key(s, &curve_id, &comp_id))
 992                         {
 993                         OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_WRONG_CURVE);
 994                         *out_alert = SSL_AD_ILLEGAL_PARAMETER;
 995                         return 0;
 996                         }
 997                 /* If Suite B only P-384+SHA384 or P-256+SHA-256 allowed */
 998                 if (tls1_suiteb(s))
 999                         {
1000                         if (curve_id == TLSEXT_curve_P_256)
1001                                 {
1002                                 if (hash != TLSEXT_hash_sha256)
1003                                         {
1004                                         OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_ILLEGAL_SUITEB_DIGEST);
1005                                         *out_alert = SSL_AD_ILLEGAL_PARAMETER;
1006                                         return 0;
1007                                         }
1008                                 }
1009                         else if (curve_id == TLSEXT_curve_P_384)
1010                                 {
1011                                 if (hash != TLSEXT_hash_sha384)
1012                                         {
1013                                         OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_ILLEGAL_SUITEB_DIGEST);
1014                                         *out_alert = SSL_AD_ILLEGAL_PARAMETER;
1015                                         return 0;
1016                                         }
1017                                 }
1018                         else
1019                                 {
1020                                 *out_alert = SSL_AD_ILLEGAL_PARAMETER;
1021                                 return 0;
1022                                 }
1023                         }
1024                 }
1025         else if (tls1_suiteb(s))
1026                 {
1027                 *out_alert = SSL_AD_ILLEGAL_PARAMETER;
1028                 return 0;
1029                 }
1030 #endif
1031
1032         /* Check signature matches a type we sent */
1033         sent_sigslen = tls12_get_psigalgs(s, &sent_sigs);
1034         for (i = 0; i < sent_sigslen; i+=2, sent_sigs+=2)
1035                 {
1036                 if (hash == sent_sigs[0] && signature == sent_sigs[1])
1037                         break;
1038                 }
1039         /* Allow fallback to SHA1 if not strict mode */
1040         if (i == sent_sigslen && (hash != TLSEXT_hash_sha1 || s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT))
1041                 {
1042                 OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_WRONG_SIGNATURE_TYPE);
1043                 *out_alert = SSL_AD_ILLEGAL_PARAMETER;
1044                 return 0;
1045                 }
1046         *out_md = tls12_get_hash(hash);
1047         if (*out_md == NULL)
1048                 {
1049                 OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_UNKNOWN_DIGEST);
1050                 *out_alert = SSL_AD_ILLEGAL_PARAMETER;
1051                 return 0;
1052                 }
1053         /* Store the digest used so applications can retrieve it if they
1054          * wish.
1055          */
1056         if (s->session && s->session->sess_cert)
1057                 s->session->sess_cert->peer_key->digest = *out_md;
1058         return 1;
1059         }
1060 /* Get a mask of disabled algorithms: an algorithm is disabled
1061  * if it isn't supported or doesn't appear in supported signature
1062  * algorithms. Unlike ssl_cipher_get_disabled this applies to a specific
1063  * session and not global settings.
1064  *
1065  */
1066 void ssl_set_client_disabled(SSL *s)
1067         {
1068         CERT *c = s->cert;
1069         const unsigned char *sigalgs;
1070         size_t i, sigalgslen;
1071         int have_rsa = 0, have_dsa = 0, have_ecdsa = 0;
1072         c->mask_a = 0;
1073         c->mask_k = 0;
1074         /* Don't allow TLS 1.2 only ciphers if we don't suppport them */
1075         if (!SSL_CLIENT_USE_TLS1_2_CIPHERS(s))
1076                 c->mask_ssl = SSL_TLSV1_2;
1077         else
1078                 c->mask_ssl = 0;
1079         /* Now go through all signature algorithms seeing if we support
1080          * any for RSA, DSA, ECDSA. Do this for all versions not just
1081          * TLS 1.2.
1082          */
1083         sigalgslen = tls12_get_psigalgs(s, &sigalgs);
1084         for (i = 0; i < sigalgslen; i += 2, sigalgs += 2)
1085                 {
1086                 switch(sigalgs[1])
1087                         {
1088                 case TLSEXT_signature_rsa:
1089                         have_rsa = 1;
1090                         break;
1091 #ifndef OPENSSL_NO_DSA
1092                 case TLSEXT_signature_dsa:
1093                         have_dsa = 1;
1094                         break;
1095 #endif
1096 #ifndef OPENSSL_NO_ECDSA
1097                 case TLSEXT_signature_ecdsa:
1098                         have_ecdsa = 1;
1099                         break;
1100 #endif
1101                         }
1102                 }
1103         /* Disable auth and static DH if we don't include any appropriate
1104          * signature algorithms.
1105          */
1106         if (!have_rsa)
1107                 {
1108                 c->mask_a |= SSL_aRSA;
1109                 c->mask_k |= SSL_kDHr|SSL_kECDHr;
1110                 }
1111         if (!have_dsa)
1112                 {
1113                 c->mask_a |= SSL_aDSS;
1114                 c->mask_k |= SSL_kDHd;
1115                 }
1116         if (!have_ecdsa)
1117                 {
1118                 c->mask_a |= SSL_aECDSA;
1119                 c->mask_k |= SSL_kECDHe;
1120                 }
1121         /* with PSK there must be client callback set */
1122         if (!s->psk_client_callback)
1123                 {
1124                 c->mask_a |= SSL_aPSK;
1125                 c->mask_k |= SSL_kPSK;
1126                 }
1127         c->valid = 1;
1128         }
1129
1130 /* header_len is the length of the ClientHello header written so far, used to
1131  * compute padding. It does not include the record header. Pass 0 if no padding
1132  * is to be done. */
1133 unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit, size_t header_len)
1134         {
1135         int extdatalen=0;
1136         unsigned char *ret = buf;
1137         unsigned char *orig = buf;
1138 #ifndef OPENSSL_NO_EC
1139         /* See if we support any ECC ciphersuites */
1140         int using_ecc = 0;
1141         if (s->version >= TLS1_VERSION || SSL_IS_DTLS(s))
1142                 {
1143                 int i;
1144                 unsigned long alg_k, alg_a;
1145                 STACK_OF(SSL_CIPHER) *cipher_stack = SSL_get_ciphers(s);
1146
1147                 for (i = 0; i < sk_SSL_CIPHER_num(cipher_stack); i++)
1148                         {
1149                         SSL_CIPHER *c = sk_SSL_CIPHER_value(cipher_stack, i);
1150
1151                         alg_k = c->algorithm_mkey;
1152                         alg_a = c->algorithm_auth;
1153                         if ((alg_k & (SSL_kEECDH|SSL_kECDHr|SSL_kECDHe)
1154                                 || (alg_a & SSL_aECDSA)))
1155                                 {
1156                                 using_ecc = 1;
1157                                 break;
1158                                 }
1159                         }
1160                 }
1161 #endif
1162
1163         /* don't add extensions for SSLv3 unless doing secure renegotiation */
1164         if (s->client_version == SSL3_VERSION
1165                                         && !s->s3->send_connection_binding)
1166                 return orig;
1167
1168         ret+=2;
1169
1170         if (ret>=limit) return NULL; /* this really never occurs, but ... */
1171
1172         if (s->tlsext_hostname != NULL)
1173                 {
1174                 /* Add TLS extension servername to the Client Hello message */
1175                 unsigned long size_str;
1176                 long lenmax;
1177
1178                 /* check for enough space.
1179                    4 for the servername type and entension length
1180                    2 for servernamelist length
1181                    1 for the hostname type
1182                    2 for hostname length
1183                    + hostname length
1184                 */
1185
1186                 if ((lenmax = limit - ret - 9) < 0
1187                     || (size_str = strlen(s->tlsext_hostname)) > (unsigned long)lenmax)
1188                         return NULL;
1189
1190                 /* extension type and length */
1191                 s2n(TLSEXT_TYPE_server_name,ret);
1192                 s2n(size_str+5,ret);
1193
1194                 /* length of servername list */
1195                 s2n(size_str+3,ret);
1196
1197                 /* hostname type, length and hostname */
1198                 *(ret++) = (unsigned char) TLSEXT_NAMETYPE_host_name;
1199                 s2n(size_str,ret);
1200                 memcpy(ret, s->tlsext_hostname, size_str);
1201                 ret+=size_str;
1202                 }
1203
1204         /* Add RI if renegotiating */
1205         if (s->renegotiate)
1206           {
1207           int el;
1208
1209           if(!ssl_add_clienthello_renegotiate_ext(s, 0, &el, 0))
1210               {
1211               OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR);
1212               return NULL;
1213               }
1214
1215           if((limit - ret - 4 - el) < 0) return NULL;
1216
1217           s2n(TLSEXT_TYPE_renegotiate,ret);
1218           s2n(el,ret);
1219
1220           if(!ssl_add_clienthello_renegotiate_ext(s, ret, &el, el))
1221               {
1222               OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR);
1223               return NULL;
1224               }
1225
1226           ret += el;
1227         }
1228
1229         if (!(SSL_get_options(s) & SSL_OP_NO_TICKET))
1230                 {
1231                 int ticklen;
1232                 if (!s->new_session && s->session && s->session->tlsext_tick)
1233                         ticklen = s->session->tlsext_ticklen;
1234                 else if (s->session && s->tlsext_session_ticket &&
1235                          s->tlsext_session_ticket->data)
1236                         {
1237                         s->session->tlsext_tick = BUF_memdup(
1238                                s->tlsext_session_ticket->data,
1239                                s->tlsext_session_ticket->length);
1240                         if (!s->session->tlsext_tick)
1241                                 return NULL;
1242                         ticklen = s->tlsext_session_ticket->length;
1243                         s->session->tlsext_ticklen = ticklen;
1244                         }
1245                 else
1246                         ticklen = 0;
1247                 if (ticklen == 0 && s->tlsext_session_ticket &&
1248                     s->tlsext_session_ticket->data == NULL)
1249                         goto skip_ext;
1250                 /* Check for enough room 2 for extension type, 2 for len
1251                  * rest for ticket
1252                  */
1253                 if ((long)(limit - ret - 4 - ticklen) < 0) return NULL;
1254                 s2n(TLSEXT_TYPE_session_ticket,ret);
1255                 s2n(ticklen,ret);
1256                 if (ticklen)
1257                         {
1258                         memcpy(ret, s->session->tlsext_tick, ticklen);
1259                         ret += ticklen;
1260                         }
1261                 }
1262                 skip_ext:
1263
1264         if (SSL_USE_SIGALGS(s))
1265                 {
1266                 size_t salglen;
1267                 const unsigned char *salg;
1268                 salglen = tls12_get_psigalgs(s, &salg);
1269                 if ((size_t)(limit - ret) < salglen + 6)
1270                         return NULL;
1271                 s2n(TLSEXT_TYPE_signature_algorithms,ret);
1272                 s2n(salglen + 2, ret);
1273                 s2n(salglen, ret);
1274                 memcpy(ret, salg, salglen);
1275                 ret += salglen;
1276                 }
1277
1278         /* TODO(fork): we probably want OCSP stapling, but it currently pulls in a lot of code. */
1279 #if 0
1280         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
1281                 {
1282                 int i;
1283                 long extlen, idlen, itmp;
1284                 OCSP_RESPID *id;
1285
1286                 idlen = 0;
1287                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
1288                         {
1289                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
1290                         itmp = i2d_OCSP_RESPID(id, NULL);
1291                         if (itmp <= 0)
1292                                 return NULL;
1293                         idlen += itmp + 2;
1294                         }
1295
1296                 if (s->tlsext_ocsp_exts)
1297                         {
1298                         extlen = i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, NULL);
1299                         if (extlen < 0)
1300                                 return NULL;
1301                         }
1302                 else
1303                         extlen = 0;
1304
1305                 if ((long)(limit - ret - 7 - extlen - idlen) < 0) return NULL;
1306                 s2n(TLSEXT_TYPE_status_request, ret);
1307                 if (extlen + idlen > 0xFFF0)
1308                         return NULL;
1309                 s2n(extlen + idlen + 5, ret);
1310                 *(ret++) = TLSEXT_STATUSTYPE_ocsp;
1311                 s2n(idlen, ret);
1312                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
1313                         {
1314                         /* save position of id len */
1315                         unsigned char *q = ret;
1316                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
1317                         /* skip over id len */
1318                         ret += 2;
1319                         itmp = i2d_OCSP_RESPID(id, &ret);
1320                         /* write id len */
1321                         s2n(itmp, q);
1322                         }
1323                 s2n(extlen, ret);
1324                 if (extlen > 0)
1325                         i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
1326                 }
1327 #endif
1328
1329 #ifndef OPENSSL_NO_NEXTPROTONEG
1330         if (s->ctx->next_proto_select_cb && !s->s3->tmp.finish_md_len)
1331                 {
1332                 /* The client advertises an emtpy extension to indicate its
1333                  * support for Next Protocol Negotiation */
1334                 if (limit - ret - 4 < 0)
1335                         return NULL;
1336                 s2n(TLSEXT_TYPE_next_proto_neg,ret);
1337                 s2n(0,ret);
1338                 }
1339 #endif
1340
1341         if (s->alpn_client_proto_list && !s->s3->tmp.finish_md_len)
1342                 {
1343                 if ((size_t)(limit - ret) < 6 + s->alpn_client_proto_list_len)
1344                         return NULL;
1345                 s2n(TLSEXT_TYPE_application_layer_protocol_negotiation,ret);
1346                 s2n(2 + s->alpn_client_proto_list_len,ret);
1347                 s2n(s->alpn_client_proto_list_len,ret);
1348                 memcpy(ret, s->alpn_client_proto_list,
1349                        s->alpn_client_proto_list_len);
1350                 ret += s->alpn_client_proto_list_len;
1351                 }
1352
1353         if (s->tlsext_channel_id_enabled)
1354                 {
1355                 /* The client advertises an emtpy extension to indicate its
1356                  * support for Channel ID. */
1357                 if (limit - ret - 4 < 0)
1358                         return NULL;
1359                 if (s->ctx->tlsext_channel_id_enabled_new)
1360                         s2n(TLSEXT_TYPE_channel_id_new,ret);
1361                 else
1362                         s2n(TLSEXT_TYPE_channel_id,ret);
1363                 s2n(0,ret);
1364                 }
1365
1366         if(SSL_get_srtp_profiles(s))
1367                 {
1368                 int el;
1369
1370                 ssl_add_clienthello_use_srtp_ext(s, 0, &el, 0);
1371
1372                 if((limit - ret - 4 - el) < 0) return NULL;
1373
1374                 s2n(TLSEXT_TYPE_use_srtp,ret);
1375                 s2n(el,ret);
1376
1377                 if(ssl_add_clienthello_use_srtp_ext(s, ret, &el, el))
1378                         {
1379                         OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR);
1380                         return NULL;
1381                         }
1382                 ret += el;
1383                 }
1384
1385 #ifndef OPENSSL_NO_EC
1386         if (using_ecc)
1387                 {
1388                 /* Add TLS extension ECPointFormats to the ClientHello message */
1389                 long lenmax;
1390                 const uint8_t *formats;
1391                 const uint16_t *curves;
1392                 size_t formats_len, curves_len, i;
1393
1394                 tls1_get_formatlist(s, &formats, &formats_len);
1395
1396                 if ((lenmax = limit - ret - 5) < 0) return NULL;
1397                 if (formats_len > (size_t)lenmax) return NULL;
1398                 if (formats_len > 255)
1399                         {
1400                         OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR);
1401                         return NULL;
1402                         }
1403
1404                 s2n(TLSEXT_TYPE_ec_point_formats,ret);
1405                 s2n(formats_len + 1,ret);
1406                 *(ret++) = (unsigned char)formats_len;
1407                 memcpy(ret, formats, formats_len);
1408                 ret+=formats_len;
1409
1410                 /* Add TLS extension EllipticCurves to the ClientHello message */
1411                 tls1_get_curvelist(s, 0, &curves, &curves_len);
1412
1413                 if ((lenmax = limit - ret - 6) < 0) return NULL;
1414                 if ((curves_len * 2) > (size_t)lenmax) return NULL;
1415                 if ((curves_len * 2) > 65532)
1416                         {
1417                         OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR);
1418                         return NULL;
1419                         }
1420
1421                 s2n(TLSEXT_TYPE_elliptic_curves,ret);
1422                 s2n((curves_len * 2) + 2, ret);
1423
1424                 /* NB: draft-ietf-tls-ecc-12.txt uses a one-byte prefix for
1425                  * elliptic_curve_list, but the examples use two bytes.
1426                  * http://www1.ietf.org/mail-archive/web/tls/current/msg00538.html
1427                  * resolves this to two bytes.
1428                  */
1429                 s2n(curves_len * 2, ret);
1430                 for (i = 0; i < curves_len; i++)
1431                         {
1432                         s2n(curves[i], ret);
1433                         }
1434                 }
1435 #endif /* OPENSSL_NO_EC */
1436
1437 #ifdef TLSEXT_TYPE_padding
1438         /* Add padding to workaround bugs in F5 terminators.
1439          * See https://tools.ietf.org/html/draft-agl-tls-padding-03
1440          *
1441          * NB: because this code works out the length of all existing
1442          * extensions it MUST always appear last. */
1443         if (header_len > 0)
1444                 {
1445                 header_len += ret - orig;
1446                 if (header_len > 0xff && header_len < 0x200)
1447                         {
1448                         size_t padding_len = 0x200 - header_len;
1449                         /* Extensions take at least four bytes to encode. Always
1450                          * include least one byte of data if including the
1451                          * extension. WebSphere Application Server 7.0 is
1452                          * intolerant to the last extension being zero-length. */
1453                         if (padding_len >= 4 + 1)
1454                                 padding_len -= 4;
1455                         else
1456                                 padding_len = 1;
1457                         if (limit - ret - 4 - (long)padding_len < 0)
1458                                 return NULL;
1459
1460                         s2n(TLSEXT_TYPE_padding, ret);
1461                         s2n(padding_len, ret);
1462                         memset(ret, 0, padding_len);
1463                         ret += padding_len;
1464                         }
1465                 }
1466 #endif
1467
1468         if ((extdatalen = ret-orig-2)== 0)
1469                 return orig;
1470
1471         s2n(extdatalen, orig);
1472         return ret;
1473         }
1474
1475 unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit)
1476         {
1477         int extdatalen=0;
1478         unsigned char *orig = buf;
1479         unsigned char *ret = buf;
1480 #ifndef OPENSSL_NO_NEXTPROTONEG
1481         int next_proto_neg_seen;
1482 #endif
1483 #ifndef OPENSSL_NO_EC
1484         unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
1485         unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
1486         int using_ecc = (alg_k & (SSL_kEECDH|SSL_kECDHr|SSL_kECDHe)) || (alg_a & SSL_aECDSA);
1487         using_ecc = using_ecc && (s->session->tlsext_ecpointformatlist != NULL);
1488 #endif
1489         /* don't add extensions for SSLv3, unless doing secure renegotiation */
1490         if (s->version == SSL3_VERSION && !s->s3->send_connection_binding)
1491                 return orig;
1492
1493         ret+=2;
1494         if (ret>=limit) return NULL; /* this really never occurs, but ... */
1495
1496         if (!s->hit && s->servername_done == 1 && s->session->tlsext_hostname != NULL)
1497                 {
1498                 if ((long)(limit - ret - 4) < 0) return NULL;
1499
1500                 s2n(TLSEXT_TYPE_server_name,ret);
1501                 s2n(0,ret);
1502                 }
1503
1504         if(s->s3->send_connection_binding)
1505         {
1506           int el;
1507
1508           if(!ssl_add_serverhello_renegotiate_ext(s, 0, &el, 0))
1509               {
1510               OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, ERR_R_INTERNAL_ERROR);
1511               return NULL;
1512               }
1513
1514           if((limit - ret - 4 - el) < 0) return NULL;
1515
1516           s2n(TLSEXT_TYPE_renegotiate,ret);
1517           s2n(el,ret);
1518
1519           if(!ssl_add_serverhello_renegotiate_ext(s, ret, &el, el))
1520               {
1521               OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, ERR_R_INTERNAL_ERROR);
1522               return NULL;
1523               }
1524
1525           ret += el;
1526         }
1527
1528 #ifndef OPENSSL_NO_EC
1529         if (using_ecc)
1530                 {
1531                 const unsigned char *plist;
1532                 size_t plistlen;
1533                 /* Add TLS extension ECPointFormats to the ServerHello message */
1534                 long lenmax;
1535
1536                 tls1_get_formatlist(s, &plist, &plistlen);
1537
1538                 if ((lenmax = limit - ret - 5) < 0) return NULL;
1539                 if (plistlen > (size_t)lenmax) return NULL;
1540                 if (plistlen > 255)
1541                         {
1542                         OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, ERR_R_INTERNAL_ERROR);
1543                         return NULL;
1544                         }
1545
1546                 s2n(TLSEXT_TYPE_ec_point_formats,ret);
1547                 s2n(plistlen + 1,ret);
1548                 *(ret++) = (unsigned char) plistlen;
1549                 memcpy(ret, plist, plistlen);
1550                 ret+=plistlen;
1551
1552                 }
1553         /* Currently the server should not respond with a SupportedCurves extension */
1554 #endif /* OPENSSL_NO_EC */
1555
1556         if (s->tlsext_ticket_expected
1557                 && !(SSL_get_options(s) & SSL_OP_NO_TICKET))
1558                 {
1559                 if ((long)(limit - ret - 4) < 0) return NULL;
1560                 s2n(TLSEXT_TYPE_session_ticket,ret);
1561                 s2n(0,ret);
1562                 }
1563
1564         if (s->tlsext_status_expected)
1565                 {
1566                 if ((long)(limit - ret - 4) < 0) return NULL;
1567                 s2n(TLSEXT_TYPE_status_request,ret);
1568                 s2n(0,ret);
1569                 }
1570
1571         if(s->srtp_profile)
1572                 {
1573                 int el;
1574
1575                 ssl_add_serverhello_use_srtp_ext(s, 0, &el, 0);
1576
1577                 if((limit - ret - 4 - el) < 0) return NULL;
1578
1579                 s2n(TLSEXT_TYPE_use_srtp,ret);
1580                 s2n(el,ret);
1581
1582                 if(ssl_add_serverhello_use_srtp_ext(s, ret, &el, el))
1583                         {
1584                         OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, ERR_R_INTERNAL_ERROR);
1585                         return NULL;
1586                         }
1587                 ret+=el;
1588                 }
1589
1590 #ifndef OPENSSL_NO_NEXTPROTONEG
1591         next_proto_neg_seen = s->s3->next_proto_neg_seen;
1592         s->s3->next_proto_neg_seen = 0;
1593         if (next_proto_neg_seen && s->ctx->next_protos_advertised_cb)
1594                 {
1595                 const unsigned char *npa;
1596                 unsigned int npalen;
1597                 int r;
1598
1599                 r = s->ctx->next_protos_advertised_cb(s, &npa, &npalen, s->ctx->next_protos_advertised_cb_arg);
1600                 if (r == SSL_TLSEXT_ERR_OK)
1601                         {
1602                         if ((long)(limit - ret - 4 - npalen) < 0) return NULL;
1603                         s2n(TLSEXT_TYPE_next_proto_neg,ret);
1604                         s2n(npalen,ret);
1605                         memcpy(ret, npa, npalen);
1606                         ret += npalen;
1607                         s->s3->next_proto_neg_seen = 1;
1608                         }
1609                 }
1610 #endif
1611
1612         if (s->s3->alpn_selected)
1613                 {
1614                 const uint8_t *selected = s->s3->alpn_selected;
1615                 size_t len = s->s3->alpn_selected_len;
1616
1617                 if ((long)(limit - ret - 4 - 2 - 1 - len) < 0)
1618                         return NULL;
1619                 s2n(TLSEXT_TYPE_application_layer_protocol_negotiation,ret);
1620                 s2n(3 + len,ret);
1621                 s2n(1 + len,ret);
1622                 *ret++ = len;
1623                 memcpy(ret, selected, len);
1624                 ret += len;
1625                 }
1626
1627         /* If the client advertised support for Channel ID, and we have it
1628          * enabled, then we want to echo it back. */
1629         if (s->s3->tlsext_channel_id_valid)
1630                 {
1631                 if (limit - ret - 4 < 0)
1632                         return NULL;
1633                 if (s->s3->tlsext_channel_id_new)
1634                         s2n(TLSEXT_TYPE_channel_id_new,ret);
1635                 else
1636                         s2n(TLSEXT_TYPE_channel_id,ret);
1637                 s2n(0,ret);
1638                 }
1639
1640         if ((extdatalen = ret-orig-2) == 0)
1641                 return orig;
1642
1643         s2n(extdatalen, orig);
1644         return ret;
1645         }
1646
1647 /* tls1_alpn_handle_client_hello is called to process the ALPN extension in a
1648  * ClientHello.
1649  *   cbs: the contents of the extension, not including the type and length.
1650  *   out_alert: a pointer to the alert value to send in the event of a zero
1651  *       return.
1652  *
1653  *   returns: 1 on success. */
1654 static int tls1_alpn_handle_client_hello(SSL *s, CBS *cbs, int *out_alert)
1655         {
1656         CBS protocol_name_list;
1657         const unsigned char *selected;
1658         unsigned char selected_len;
1659         int r;
1660
1661         if (s->ctx->alpn_select_cb == NULL)
1662                 return 1;
1663
1664         if (!CBS_get_u16_length_prefixed(cbs, &protocol_name_list) ||
1665                 CBS_len(cbs) != 0 ||
1666                 CBS_len(&protocol_name_list) < 2)
1667                 goto parse_error;
1668
1669         /* Validate the protocol list. */
1670         CBS protocol_name_list_copy = protocol_name_list;
1671         while (CBS_len(&protocol_name_list_copy) > 0)
1672                 {
1673                 CBS protocol_name;
1674
1675                 if (!CBS_get_u8_length_prefixed(&protocol_name_list_copy, &protocol_name))
1676                         goto parse_error;
1677                 }
1678
1679         r = s->ctx->alpn_select_cb(s, &selected, &selected_len,
1680                 CBS_data(&protocol_name_list), CBS_len(&protocol_name_list),
1681                 s->ctx->alpn_select_cb_arg);
1682         if (r == SSL_TLSEXT_ERR_OK) {
1683                 if (s->s3->alpn_selected)
1684                         OPENSSL_free(s->s3->alpn_selected);
1685                 s->s3->alpn_selected = BUF_memdup(selected, selected_len);
1686                 if (!s->s3->alpn_selected)
1687                         {
1688                         *out_alert = SSL_AD_INTERNAL_ERROR;
1689                         return 0;
1690                         }
1691                 s->s3->alpn_selected_len = selected_len;
1692         }
1693         return 1;
1694
1695 parse_error:
1696         *out_alert = SSL_AD_DECODE_ERROR;
1697         return 0;
1698         }
1699
1700 static int ssl_scan_clienthello_tlsext(SSL *s, CBS *cbs, int *out_alert)
1701         {
1702         int renegotiate_seen = 0;
1703         CBS extensions;
1704         size_t i;
1705
1706         s->servername_done = 0;
1707         s->tlsext_status_type = -1;
1708 #ifndef OPENSSL_NO_NEXTPROTONEG
1709         s->s3->next_proto_neg_seen = 0;
1710 #endif
1711
1712         if (s->s3->alpn_selected)
1713                 {
1714                 OPENSSL_free(s->s3->alpn_selected);
1715                 s->s3->alpn_selected = NULL;
1716                 }
1717
1718         /* Clear any signature algorithms extension received */
1719         if (s->cert->peer_sigalgs)
1720                 {
1721                 OPENSSL_free(s->cert->peer_sigalgs);
1722                 s->cert->peer_sigalgs = NULL;
1723                 }
1724         /* Clear any shared sigtnature algorithms */
1725         if (s->cert->shared_sigalgs)
1726                 {
1727                 OPENSSL_free(s->cert->shared_sigalgs);
1728                 s->cert->shared_sigalgs = NULL;
1729                 }
1730         /* Clear certificate digests and validity flags */
1731         for (i = 0; i < SSL_PKEY_NUM; i++)
1732                 {
1733                 s->cert->pkeys[i].digest = NULL;
1734                 s->cert->pkeys[i].valid_flags = 0;
1735                 }
1736
1737         /* TODO(fork): we probably want OCSP stapling support, but this pulls in
1738          * a lot of code. */
1739 #if 0
1740         /* Clear OCSP state. */
1741         s->tlsext_status_type = -1;
1742         if (s->tlsext_ocsp_ids)
1743                 {
1744                 sk_OCSP_RESPID_pop_free(s->tlsext_ocsp_ids, OCSP_RESPID_free);
1745                 s->tlsext_ocsp_ids = NULL;
1746                 }
1747         if (s->tlsext_ocsp_exts)
1748                 {
1749                 sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts, X509_EXTENSION_free);
1750                 s->tlsext_ocsp_exts = NULL;
1751                 }
1752 #endif
1753
1754         /* There may be no extensions. */
1755         if (CBS_len(cbs) == 0)
1756                 {
1757                 goto ri_check;
1758                 }
1759
1760         /* Decode the extensions block and check it is valid. */
1761         if (!CBS_get_u16_length_prefixed(cbs, &extensions) ||
1762                 !tls1_check_duplicate_extensions(&extensions))
1763                 {
1764                 *out_alert = SSL_AD_DECODE_ERROR;
1765                 return 0;
1766                 }
1767
1768         while (CBS_len(&extensions) != 0)
1769                 {
1770                 uint16_t type;
1771                 CBS extension;
1772
1773                 /* Decode the next extension. */
1774                 if (!CBS_get_u16(&extensions, &type) ||
1775                         !CBS_get_u16_length_prefixed(&extensions, &extension))
1776                         {
1777                         *out_alert = SSL_AD_DECODE_ERROR;
1778                         return 0;
1779                         }
1780
1781                 if (s->tlsext_debug_cb)
1782                         {
1783                         s->tlsext_debug_cb(s, 0, type, (unsigned char*)CBS_data(&extension),
1784                                 CBS_len(&extension), s->tlsext_debug_arg);
1785                         }
1786
1787 /* The servername extension is treated as follows:
1788
1789    - Only the hostname type is supported with a maximum length of 255.
1790    - The servername is rejected if too long or if it contains zeros,
1791      in which case an fatal alert is generated.
1792    - The servername field is maintained together with the session cache.
1793    - When a session is resumed, the servername call back invoked in order
1794      to allow the application to position itself to the right context.
1795    - The servername is acknowledged if it is new for a session or when
1796      it is identical to a previously used for the same session.
1797      Applications can control the behaviour.  They can at any time
1798      set a 'desirable' servername for a new SSL object. This can be the
1799      case for example with HTTPS when a Host: header field is received and
1800      a renegotiation is requested. In this case, a possible servername
1801      presented in the new client hello is only acknowledged if it matches
1802      the value of the Host: field.
1803    - Applications must  use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
1804      if they provide for changing an explicit servername context for the session,
1805      i.e. when the session has been established with a servername extension.
1806    - On session reconnect, the servername extension may be absent.
1807
1808 */
1809
1810                 if (type == TLSEXT_TYPE_server_name)
1811                         {
1812                         CBS server_name_list;
1813
1814                         if (!CBS_get_u16_length_prefixed(&extension, &server_name_list) ||
1815                                 CBS_len(&server_name_list) < 1 ||
1816                                 CBS_len(&extension) != 0)
1817                                 {
1818                                 *out_alert = SSL_AD_DECODE_ERROR;
1819                                 return 0;
1820                                 }
1821
1822                         /* Decode each ServerName in the extension. */
1823                         while (CBS_len(&server_name_list) > 0)
1824                                 {
1825                                 uint8_t name_type;
1826                                 CBS host_name;
1827
1828                                 /* Decode the NameType. */
1829                                 if (!CBS_get_u8(&server_name_list, &name_type))
1830                                         {
1831                                         *out_alert = SSL_AD_DECODE_ERROR;
1832                                         return 0;
1833                                         }
1834
1835                                 /* Only host_name is supported. */
1836                                 if (name_type != TLSEXT_NAMETYPE_host_name)
1837                                         continue;
1838
1839                                 if (!s->hit)
1840                                         {
1841                                         if (s->session->tlsext_hostname)
1842                                                 {
1843                                                 /* The ServerNameList MUST NOT
1844                                                    contain more than one name of
1845                                                    the same name_type. */
1846                                                 *out_alert = SSL_AD_DECODE_ERROR;
1847                                                 return 0;
1848                                                 }
1849
1850                                         if (!CBS_get_u16_length_prefixed(&server_name_list, &host_name) ||
1851                                                 CBS_len(&host_name) < 1)
1852                                                 {
1853                                                 *out_alert = SSL_AD_DECODE_ERROR;
1854                                                 return 0;
1855                                                 }
1856
1857                                         if (CBS_len(&host_name) > TLSEXT_MAXLEN_host_name ||
1858                                                 CBS_contains_zero_byte(&host_name))
1859                                                 {
1860                                                 *out_alert = SSL_AD_UNRECOGNIZED_NAME;
1861                                                 return 0;
1862                                                 }
1863
1864                                         /* Copy the hostname as a string. */
1865                                         if (!CBS_strdup(&host_name, &s->session->tlsext_hostname))
1866                                                 {
1867                                                 *out_alert = SSL_AD_INTERNAL_ERROR;
1868                                                 return 0;
1869                                                 }
1870                                         s->servername_done = 1;
1871                                         }
1872                                 else
1873                                         {
1874                                         s->servername_done = s->session->tlsext_hostname
1875                                                 && strlen(s->session->tlsext_hostname) == CBS_len(&host_name)
1876                                                 && strncmp(s->session->tlsext_hostname,
1877                                                         (char *)CBS_data(&host_name), CBS_len(&host_name)) == 0;
1878                                         }
1879                                 }
1880                         }
1881
1882 #ifndef OPENSSL_NO_EC
1883                 else if (type == TLSEXT_TYPE_ec_point_formats)
1884                         {
1885                         CBS ec_point_format_list;
1886
1887                         if (!CBS_get_u8_length_prefixed(&extension, &ec_point_format_list) ||
1888                                 CBS_len(&extension) != 0)
1889                                 {
1890                                 *out_alert = SSL_AD_DECODE_ERROR;
1891                                 return 0;
1892                                 }
1893
1894                         if (!s->hit)
1895                                 {
1896                                 if (!CBS_stow(&ec_point_format_list,
1897                                                 &s->session->tlsext_ecpointformatlist,
1898                                                 &s->session->tlsext_ecpointformatlist_length))
1899                                         {
1900                                         *out_alert = SSL_AD_INTERNAL_ERROR;
1901                                         return 0;
1902                                         }
1903                                 }
1904                         }
1905                 else if (type == TLSEXT_TYPE_elliptic_curves)
1906                         {
1907                         CBS elliptic_curve_list;
1908                         size_t i, num_curves;
1909
1910                         if (!CBS_get_u16_length_prefixed(&extension, &elliptic_curve_list) ||
1911                                 CBS_len(&elliptic_curve_list) == 0 ||
1912                                 (CBS_len(&elliptic_curve_list) & 1) != 0 ||
1913                                 CBS_len(&extension) != 0)
1914                                 {
1915                                 *out_alert = SSL_AD_DECODE_ERROR;
1916                                 return 0;
1917                                 }
1918
1919                         if (!s->hit)
1920                                 {
1921                                 if (s->session->tlsext_ellipticcurvelist)
1922                                         {
1923                                         OPENSSL_free(s->session->tlsext_ellipticcurvelist);
1924                                         s->session->tlsext_ellipticcurvelist_length = 0;
1925                                         }
1926                                 s->session->tlsext_ellipticcurvelist =
1927                                         (uint16_t*)OPENSSL_malloc(CBS_len(&elliptic_curve_list));
1928                                 if (s->session->tlsext_ellipticcurvelist == NULL)
1929                                         {
1930                                         *out_alert = SSL_AD_INTERNAL_ERROR;
1931                                         return 0;
1932                                         }
1933                                 num_curves = CBS_len(&elliptic_curve_list) / 2;
1934                                 for (i = 0; i < num_curves; i++)
1935                                         {
1936                                         if (!CBS_get_u16(&elliptic_curve_list,
1937                                                         &s->session->tlsext_ellipticcurvelist[i]))
1938                                                 {
1939                                                 *out_alert = SSL_AD_INTERNAL_ERROR;
1940                                                 return 0;
1941                                                 }
1942                                         }
1943                                 if (CBS_len(&elliptic_curve_list) != 0)
1944                                         {
1945                                         *out_alert = SSL_AD_INTERNAL_ERROR;
1946                                         return 0;
1947                                         }
1948                                 s->session->tlsext_ellipticcurvelist_length = num_curves;
1949                                 }
1950                         }
1951 #endif /* OPENSSL_NO_EC */
1952                 else if (type == TLSEXT_TYPE_session_ticket)
1953                         {
1954                         if (s->tls_session_ticket_ext_cb &&
1955                                 !s->tls_session_ticket_ext_cb(s, CBS_data(&extension), CBS_len(&extension), s->tls_session_ticket_ext_cb_arg))
1956                                 {
1957                                 *out_alert = SSL_AD_INTERNAL_ERROR;
1958                                 return 0;
1959                                 }
1960                         }
1961                 else if (type == TLSEXT_TYPE_renegotiate)
1962                         {
1963                         if (!ssl_parse_clienthello_renegotiate_ext(s, &extension, out_alert))
1964                                 return 0;
1965                         renegotiate_seen = 1;
1966                         }
1967                 else if (type == TLSEXT_TYPE_signature_algorithms)
1968                         {
1969                         CBS supported_signature_algorithms;
1970
1971                         if (!CBS_get_u16_length_prefixed(&extension, &supported_signature_algorithms) ||
1972                                 CBS_len(&extension) != 0)
1973                                 {
1974                                 *out_alert = SSL_AD_DECODE_ERROR;
1975                                 return 0;
1976                                 }
1977
1978                         /* Ensure the signature algorithms are non-empty. It
1979                          * contains a list of SignatureAndHashAlgorithms
1980                          * which are two bytes each. */
1981                         if (CBS_len(&supported_signature_algorithms) == 0 ||
1982                                 (CBS_len(&supported_signature_algorithms) % 2) != 0)
1983                                 {
1984                                 *out_alert = SSL_AD_DECODE_ERROR;
1985                                 return 0;
1986                                 }
1987
1988                         if (!tls1_process_sigalgs(s, &supported_signature_algorithms))
1989                                 {
1990                                 *out_alert = SSL_AD_DECODE_ERROR;
1991                                 return 0;
1992                                 }
1993                         /* If sigalgs received and no shared algorithms fatal
1994                          * error.
1995                          */
1996                         if (s->cert->peer_sigalgs && !s->cert->shared_sigalgs)
1997                                 {
1998                                 OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, SSL_R_NO_SHARED_SIGATURE_ALGORITHMS);
1999                                 *out_alert = SSL_AD_ILLEGAL_PARAMETER;
2000                                 return 0;
2001                                 }
2002                         }
2003
2004                 /* TODO(fork): we probably want OCSP stapling support, but this pulls in a lot of code. */
2005 #if 0
2006                 else if (type == TLSEXT_TYPE_status_request)
2007                         {
2008                         uint8_t status_type;
2009                         CBS responder_id_list;
2010                         CBS request_extensions;
2011
2012                         if (!CBS_get_u8(&extension, &status_type))
2013                                 {
2014                                 *out_alert = SSL_AD_DECODE_ERROR;
2015                                 return 0;
2016                                 }
2017
2018                         /* Only OCSP is supported. */
2019                         if (status_type != TLSEXT_STATUSTYPE_ocsp)
2020                                 continue;
2021
2022                         s->tlsext_status_type = status_type;
2023
2024                         /* Extension consists of a responder_id_list and
2025                          * request_extensions. */
2026                         if (!CBS_get_u16_length_prefixed(&extension, &responder_id_list) ||
2027                                 !CBS_get_u16_length_prefixed(&extension, &request_extensions) ||
2028                                 CBS_len(&extension) != 0)
2029                                 {
2030                                 *out_alert = SSL_AD_DECODE_ERROR;
2031                                 return 0;
2032                                 }
2033
2034                         if (CBS_len(&responder_id_list) > 0)
2035                                 {
2036                                 s->tlsext_ocsp_ids = sk_OCSP_RESPID_new_null();
2037                                 if (s->tlsext_ocsp_ids == NULL)
2038                                         {
2039                                         *out_alert = SSL_AD_INTERNAL_ERROR;
2040                                         return 0;
2041                                         }
2042                                 }
2043
2044                         /* Parse out the responder IDs. */
2045                         while (CBS_len(&responder_id_list) > 0)
2046                                 {
2047                                 CBS responder_id;
2048                                 OCSP_RESPID *id;
2049                                 const uint8_t *data;
2050
2051                                 /* Each ResponderID must have size at least 1. */
2052                                 if (!CBS_get_u16_length_prefixed(&responder_id_list, &responder_id) ||
2053                                         CBS_len(&responder_id) < 1)
2054                                         {
2055                                         *out_alert = SSL_AD_DECODE_ERROR;
2056                                         return 0;
2057                                         }
2058
2059                                 /* TODO(fork): Add CBS versions of d2i_FOO_BAR. */
2060                                 data = CBS_data(&responder_id);
2061                                 id = d2i_OCSP_RESPID(NULL, &data, CBS_len(&responder_id));
2062                                 if (!id)
2063                                         {
2064                                         *out_alert = SSL_AD_DECODE_ERROR;
2065                                         return 0;
2066                                         }
2067                                 if (!CBS_skip(&responder_id, data - CBS_data(&responder_id)))
2068                                         {
2069                                         /* This should never happen. */
2070                                         *out_alert = SSL_AD_INTERNAL_ERROR;
2071                                         OCSP_RESPID_free(id);
2072                                         return 0;
2073                                         }
2074                                 if (CBS_len(&responder_id) != 0)
2075                                         {
2076                                         *out_alert = SSL_AD_DECODE_ERROR;
2077                                         OCSP_RESPID_free(id);
2078                                         return 0;
2079                                         }
2080
2081                                 if (!sk_OCSP_RESPID_push(s->tlsext_ocsp_ids, id))
2082                                         {
2083                                         *out_alert = SSL_AD_INTERNAL_ERROR;
2084                                         OCSP_RESPID_free(id);
2085                                         return 0;
2086                                         }
2087                                 }
2088
2089                         /* Parse out request_extensions. */
2090                         if (CBS_len(&request_extensions) > 0)
2091                                 {
2092                                 const uint8_t *data;
2093
2094                                 data = CBS_data(&request_extensions);
2095                                 s->tlsext_ocsp_exts = d2i_X509_EXTENSIONS(NULL,
2096                                         &data, CBS_len(&request_extensions));
2097                                 if (s->tlsext_ocsp_exts == NULL)
2098                                         {
2099                                         *out_alert = SSL_AD_DECODE_ERROR;
2100                                         return 0;
2101                                         }
2102                                 if (!CBS_skip(&request_extensions, data - CBS_data(&request_extensions)))
2103                                         {
2104                                         /* This should never happen. */
2105                                         *out_alert = SSL_AD_INTERNAL_ERROR;
2106                                         return 0;
2107                                         }
2108                                 if (CBS_len(&request_extensions) != 0)
2109                                         {
2110                                         *out_alert = SSL_AD_DECODE_ERROR;
2111                                         return 0;
2112                                         }
2113                                 }
2114                         }
2115 #endif
2116
2117 #ifndef OPENSSL_NO_NEXTPROTONEG
2118                 else if (type == TLSEXT_TYPE_next_proto_neg &&
2119                          s->s3->tmp.finish_md_len == 0 &&
2120                          s->s3->alpn_selected == NULL)
2121                         {
2122                         /* The extension must be empty. */
2123                         if (CBS_len(&extension) != 0)
2124                                 {
2125                                 *out_alert = SSL_AD_DECODE_ERROR;
2126                                 return 0;
2127                                 }
2128
2129                         /* We shouldn't accept this extension on a
2130                          * renegotiation.
2131                          *
2132                          * s->new_session will be set on renegotiation, but we
2133                          * probably shouldn't rely that it couldn't be set on
2134                          * the initial renegotation too in certain cases (when
2135                          * there's some other reason to disallow resuming an
2136                          * earlier session -- the current code won't be doing
2137                          * anything like that, but this might change).
2138
2139                          * A valid sign that there's been a previous handshake
2140                          * in this connection is if s->s3->tmp.finish_md_len >
2141                          * 0.  (We are talking about a check that will happen
2142                          * in the Hello protocol round, well before a new
2143                          * Finished message could have been computed.) */
2144                         s->s3->next_proto_neg_seen = 1;
2145                         }
2146 #endif
2147
2148                 else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation &&
2149                          s->ctx->alpn_select_cb &&
2150                          s->s3->tmp.finish_md_len == 0)
2151                         {
2152                         if (!tls1_alpn_handle_client_hello(s, &extension, out_alert))
2153                                 return 0;
2154 #ifndef OPENSSL_NO_NEXTPROTONEG
2155                         /* ALPN takes precedence over NPN. */
2156                         s->s3->next_proto_neg_seen = 0;
2157 #endif
2158                         }
2159
2160                 else if (type == TLSEXT_TYPE_channel_id &&
2161                          s->tlsext_channel_id_enabled)
2162                         {
2163                         /* The extension must be empty. */
2164                         if (CBS_len(&extension) != 0)
2165                                 {
2166                                 *out_alert = SSL_AD_DECODE_ERROR;
2167                                 return 0;
2168                                 }
2169
2170                         s->s3->tlsext_channel_id_valid = 1;
2171                         }
2172
2173                 else if (type == TLSEXT_TYPE_channel_id_new &&
2174                          s->tlsext_channel_id_enabled)
2175                         {
2176                         /* The extension must be empty. */
2177                         if (CBS_len(&extension) != 0)
2178                                 {
2179                                 *out_alert = SSL_AD_DECODE_ERROR;
2180                                 return 0;
2181                                 }
2182
2183                         s->s3->tlsext_channel_id_valid = 1;
2184                         s->s3->tlsext_channel_id_new = 1;
2185                         }
2186
2187
2188                 /* session ticket processed earlier */
2189                 else if (type == TLSEXT_TYPE_use_srtp)
2190                         {
2191                         if (!ssl_parse_clienthello_use_srtp_ext(s, &extension, out_alert))
2192                                 return 0;
2193                         }
2194                 }
2195
2196         ri_check:
2197
2198         /* Need RI if renegotiating */
2199
2200         if (!renegotiate_seen && s->renegotiate &&
2201                 !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
2202                 {
2203                 *out_alert = SSL_AD_HANDSHAKE_FAILURE;
2204                 OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
2205                 return 0;
2206                 }
2207         /* If no signature algorithms extension set default values */
2208         if (!s->cert->peer_sigalgs)
2209                 ssl_cert_set_default_md(s->cert);
2210
2211         return 1;
2212         }
2213
2214 int ssl_parse_clienthello_tlsext(SSL *s, CBS *cbs)
2215         {
2216         int alert = -1;
2217         if (ssl_scan_clienthello_tlsext(s, cbs, &alert) <= 0)
2218                 {
2219                 ssl3_send_alert(s, SSL3_AL_FATAL, alert);
2220                 return 0;
2221                 }
2222
2223         if (ssl_check_clienthello_tlsext_early(s) <= 0)
2224                 {
2225                 OPENSSL_PUT_ERROR(SSL, ssl_parse_clienthello_tlsext, SSL_R_CLIENTHELLO_TLSEXT);
2226                 return 0;
2227                 }
2228         return 1;
2229         }
2230
2231 #ifndef OPENSSL_NO_NEXTPROTONEG
2232 /* ssl_next_proto_validate validates a Next Protocol Negotiation block. No
2233  * elements of zero length are allowed and the set of elements must exactly fill
2234  * the length of the block. */
2235 static char ssl_next_proto_validate(const CBS *cbs)
2236         {
2237         CBS copy = *cbs;
2238
2239         while (CBS_len(&copy) != 0)
2240                 {
2241                 CBS proto;
2242                 if (!CBS_get_u8_length_prefixed(&copy, &proto) ||
2243                         CBS_len(&proto) == 0)
2244                         {
2245                         return 0;
2246                         }
2247                 }
2248         return 1;
2249         }
2250 #endif
2251
2252 static int ssl_scan_serverhello_tlsext(SSL *s, CBS *cbs, int *out_alert)
2253         {
2254         int tlsext_servername = 0;
2255         int renegotiate_seen = 0;
2256         CBS extensions;
2257
2258 #ifndef OPENSSL_NO_NEXTPROTONEG
2259         s->s3->next_proto_neg_seen = 0;
2260 #endif
2261
2262         s->tlsext_ticket_expected = 0;
2263
2264         if (s->s3->alpn_selected)
2265                 {
2266                 OPENSSL_free(s->s3->alpn_selected);
2267                 s->s3->alpn_selected = NULL;
2268                 }
2269
2270         /* There may be no extensions. */
2271         if (CBS_len(cbs) == 0)
2272                 {
2273                 goto ri_check;
2274                 }
2275
2276         /* Decode the extensions block and check it is valid. */
2277         if (!CBS_get_u16_length_prefixed(cbs, &extensions) ||
2278                 !tls1_check_duplicate_extensions(&extensions))
2279                 {
2280                 *out_alert = SSL_AD_DECODE_ERROR;
2281                 return 0;
2282                 }
2283
2284         while (CBS_len(&extensions) != 0)
2285                 {
2286                 uint16_t type;
2287                 CBS extension;
2288
2289                 /* Decode the next extension. */
2290                 if (!CBS_get_u16(&extensions, &type) ||
2291                         !CBS_get_u16_length_prefixed(&extensions, &extension))
2292                         {
2293                         *out_alert = SSL_AD_DECODE_ERROR;
2294                         return 0;
2295                         }
2296
2297                 if (s->tlsext_debug_cb)
2298                         {
2299                         s->tlsext_debug_cb(s, 1, type, (unsigned char*)CBS_data(&extension),
2300                                 CBS_len(&extension), s->tlsext_debug_arg);
2301                         }
2302
2303                 if (type == TLSEXT_TYPE_server_name)
2304                         {
2305                         /* The extension must be empty. */
2306                         if (CBS_len(&extension) != 0)
2307                                 {
2308                                 *out_alert = SSL_AD_DECODE_ERROR;
2309                                 return 0;
2310                                 }
2311                         /* We must have sent it in ClientHello. */
2312                         if (s->tlsext_hostname == NULL)
2313                                 {
2314                                 *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
2315                                 return 0;
2316                                 }
2317                         tlsext_servername = 1;
2318                         }
2319 #ifndef OPENSSL_NO_EC
2320                 else if (type == TLSEXT_TYPE_ec_point_formats)
2321                         {
2322                         CBS ec_point_format_list;
2323
2324                         if (!CBS_get_u8_length_prefixed(&extension, &ec_point_format_list) ||
2325                                 CBS_len(&extension) != 0)
2326                                 {
2327                                 *out_alert = SSL_AD_DECODE_ERROR;
2328                                 return 0;
2329                                 }
2330
2331                         if (!s->hit)
2332                                 {
2333                                 if (!CBS_stow(&ec_point_format_list,
2334                                                 &s->session->tlsext_ecpointformatlist,
2335                                                 &s->session->tlsext_ecpointformatlist_length))
2336                                         {
2337                                         *out_alert = SSL_AD_INTERNAL_ERROR;
2338                                         return 0;
2339                                         }
2340                                 }
2341                         }
2342 #endif /* OPENSSL_NO_EC */
2343                 else if (type == TLSEXT_TYPE_session_ticket)
2344                         {
2345                         if (s->tls_session_ticket_ext_cb &&
2346                                 !s->tls_session_ticket_ext_cb(s, CBS_data(&extension), CBS_len(&extension),
2347                                         s->tls_session_ticket_ext_cb_arg))
2348                                 {
2349                                 *out_alert = SSL_AD_INTERNAL_ERROR;
2350                                 return 0;
2351                                 }
2352
2353                         if ((SSL_get_options(s) & SSL_OP_NO_TICKET) || CBS_len(&extension) > 0)
2354                                 {
2355                                 *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
2356                                 return 0;
2357                                 }
2358
2359                         s->tlsext_ticket_expected = 1;
2360                         }
2361                 else if (type == TLSEXT_TYPE_status_request)
2362                         {
2363                         /* The extension MUST be empty and may only sent if
2364                          * we've requested a status request message. */
2365                         if (CBS_len(&extension) != 0)
2366                                 {
2367                                 *out_alert = SSL_AD_DECODE_ERROR;
2368                                 return 0;
2369                                 }
2370                         if (s->tlsext_status_type == -1)
2371                                 {
2372                                 *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
2373                                 return 0;
2374                                 }
2375                         /* Set a flag to expect a CertificateStatus message */
2376                         s->tlsext_status_expected = 1;
2377                         }
2378 #ifndef OPENSSL_NO_NEXTPROTONEG
2379                 else if (type == TLSEXT_TYPE_next_proto_neg && s->s3->tmp.finish_md_len == 0) {
2380                 unsigned char *selected;
2381                 unsigned char selected_len;
2382
2383                 /* We must have requested it. */
2384                 if (s->ctx->next_proto_select_cb == NULL)
2385                         {
2386                         *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
2387                         return 0;
2388                         }
2389
2390                 /* The data must be valid. */
2391                 if (!ssl_next_proto_validate(&extension))
2392                         {
2393                         *out_alert = SSL_AD_DECODE_ERROR;
2394                         return 0;
2395                         }
2396
2397                 if (s->ctx->next_proto_select_cb(s, &selected, &selected_len,
2398                                 CBS_data(&extension), CBS_len(&extension),
2399                                 s->ctx->next_proto_select_cb_arg) != SSL_TLSEXT_ERR_OK)
2400                         {
2401                         *out_alert = SSL_AD_INTERNAL_ERROR;
2402                         return 0;
2403                         }
2404
2405                 s->next_proto_negotiated = BUF_memdup(selected, selected_len);
2406                 if (s->next_proto_negotiated == NULL)
2407                         {
2408                         *out_alert = SSL_AD_INTERNAL_ERROR;
2409                         return 0;
2410                         }
2411                 s->next_proto_negotiated_len = selected_len;
2412                 s->s3->next_proto_neg_seen = 1;
2413                 }
2414 #endif
2415                 else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation)
2416                         {
2417                         CBS protocol_name_list, protocol_name;
2418
2419                         /* We must have requested it. */
2420                         if (s->alpn_client_proto_list == NULL)
2421                                 {
2422                                 *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
2423                                 return 0;
2424                                 }
2425
2426                         /* The extension data consists of a ProtocolNameList
2427                          * which must have exactly one ProtocolName. Each of
2428                          * these is length-prefixed. */
2429                         if (!CBS_get_u16_length_prefixed(&extension, &protocol_name_list) ||
2430                                 CBS_len(&extension) != 0 ||
2431                                 !CBS_get_u8_length_prefixed(&protocol_name_list, &protocol_name) ||
2432                                 CBS_len(&protocol_name_list) != 0)
2433                                 {
2434                                 *out_alert = SSL_AD_DECODE_ERROR;
2435                                 return 0;
2436                                 }
2437
2438                         if (!CBS_stow(&protocol_name,
2439                                         &s->s3->alpn_selected,
2440                                         &s->s3->alpn_selected_len))
2441                                 {
2442                                 *out_alert = SSL_AD_INTERNAL_ERROR;
2443                                 return 0;
2444                                 }
2445                         }
2446
2447                 else if (type == TLSEXT_TYPE_channel_id)
2448                         {
2449                         if (CBS_len(&extension) != 0)
2450                                 {
2451                                 *out_alert = SSL_AD_DECODE_ERROR;
2452                                 return 0;
2453                                 }
2454                         s->s3->tlsext_channel_id_valid = 1;
2455                         }
2456                 else if (type == TLSEXT_TYPE_channel_id_new)
2457                         {
2458                         if (CBS_len(&extension) != 0)
2459                                 {
2460                                 *out_alert = SSL_AD_DECODE_ERROR;
2461                                 return 0;
2462                                 }
2463                         s->s3->tlsext_channel_id_valid = 1;
2464                         s->s3->tlsext_channel_id_new = 1;
2465                         }
2466
2467                 else if (type == TLSEXT_TYPE_renegotiate)
2468                         {
2469                         if (!ssl_parse_serverhello_renegotiate_ext(s, &extension, out_alert))
2470                                 return 0;
2471                         renegotiate_seen = 1;
2472                         }
2473                 else if (type == TLSEXT_TYPE_use_srtp)
2474                         {
2475                         if (!ssl_parse_serverhello_use_srtp_ext(s, &extension, out_alert))
2476                                 return 0;
2477                         }
2478                 }
2479
2480         if (!s->hit && tlsext_servername == 1)
2481                 {
2482                 if (s->tlsext_hostname)
2483                         {
2484                         if (s->session->tlsext_hostname == NULL)
2485                                 {
2486                                 s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);
2487                                 if (!s->session->tlsext_hostname)
2488                                         {
2489                                         *out_alert = SSL_AD_UNRECOGNIZED_NAME;
2490                                         return 0;
2491                                         }
2492                                 }
2493                         else
2494                                 {
2495                                 *out_alert = SSL_AD_DECODE_ERROR;
2496                                 return 0;
2497                                 }
2498                         }
2499                 }
2500
2501         ri_check:
2502
2503         /* Determine if we need to see RI. Strictly speaking if we want to
2504          * avoid an attack we should *always* see RI even on initial server
2505          * hello because the client doesn't see any renegotiation during an
2506          * attack. However this would mean we could not connect to any server
2507          * which doesn't support RI so for the immediate future tolerate RI
2508          * absence on initial connect only.
2509          */
2510         if (!renegotiate_seen
2511                 && !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
2512                 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
2513                 {
2514                 *out_alert = SSL_AD_HANDSHAKE_FAILURE;
2515                 OPENSSL_PUT_ERROR(SSL, ssl_scan_serverhello_tlsext, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
2516                 return 0;
2517                 }
2518
2519         return 1;
2520         }
2521
2522
2523 int ssl_prepare_clienthello_tlsext(SSL *s)
2524         {
2525         return 1;
2526         }
2527
2528 int ssl_prepare_serverhello_tlsext(SSL *s)
2529         {
2530         return 1;
2531         }
2532
2533 static int ssl_check_clienthello_tlsext_early(SSL *s)
2534         {
2535         int ret=SSL_TLSEXT_ERR_NOACK;
2536         int al = SSL_AD_UNRECOGNIZED_NAME;
2537
2538 #ifndef OPENSSL_NO_EC
2539         /* The handling of the ECPointFormats extension is done elsewhere, namely in
2540          * ssl3_choose_cipher in s3_lib.c.
2541          */
2542         /* The handling of the EllipticCurves extension is done elsewhere, namely in
2543          * ssl3_choose_cipher in s3_lib.c.
2544          */
2545 #endif
2546
2547         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
2548                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
2549         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
2550                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
2551
2552         switch (ret)
2553                 {
2554                 case SSL_TLSEXT_ERR_ALERT_FATAL:
2555                         ssl3_send_alert(s,SSL3_AL_FATAL,al);
2556                         return -1;
2557
2558                 case SSL_TLSEXT_ERR_ALERT_WARNING:
2559                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
2560                         return 1;
2561
2562                 case SSL_TLSEXT_ERR_NOACK:
2563                         s->servername_done=0;
2564                         default:
2565                 return 1;
2566                 }
2567         }
2568
2569 int ssl_check_clienthello_tlsext_late(SSL *s)
2570         {
2571         int ret = SSL_TLSEXT_ERR_OK;
2572         int al;
2573
2574         /* If status request then ask callback what to do.
2575          * Note: this must be called after servername callbacks in case
2576          * the certificate has changed, and must be called after the cipher
2577          * has been chosen because this may influence which certificate is sent
2578          */
2579         if ((s->tlsext_status_type != -1) && s->ctx && s->ctx->tlsext_status_cb)
2580                 {
2581                 int r;
2582                 CERT_PKEY *certpkey;
2583                 certpkey = ssl_get_server_send_pkey(s);
2584                 /* If no certificate can't return certificate status */
2585                 if (certpkey == NULL)
2586                         {
2587                         s->tlsext_status_expected = 0;
2588                         return 1;
2589                         }
2590                 /* Set current certificate to one we will use so
2591                  * SSL_get_certificate et al can pick it up.
2592                  */
2593                 s->cert->key = certpkey;
2594                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
2595                 switch (r)
2596                         {
2597                         /* We don't want to send a status request response */
2598                         case SSL_TLSEXT_ERR_NOACK:
2599                                 s->tlsext_status_expected = 0;
2600                                 break;
2601                         /* status request response should be sent */
2602                         case SSL_TLSEXT_ERR_OK:
2603                                 if (s->tlsext_ocsp_resp)
2604                                         s->tlsext_status_expected = 1;
2605                                 else
2606                                         s->tlsext_status_expected = 0;
2607                                 break;
2608                         /* something bad happened */
2609                         case SSL_TLSEXT_ERR_ALERT_FATAL:
2610                                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
2611                                 al = SSL_AD_INTERNAL_ERROR;
2612                                 goto err;
2613                         }
2614                 }
2615         else
2616                 s->tlsext_status_expected = 0;
2617
2618  err:
2619         switch (ret)
2620                 {
2621                 case SSL_TLSEXT_ERR_ALERT_FATAL:
2622                         ssl3_send_alert(s, SSL3_AL_FATAL, al);
2623                         return -1;
2624
2625                 case SSL_TLSEXT_ERR_ALERT_WARNING:
2626                         ssl3_send_alert(s, SSL3_AL_WARNING, al);
2627                         return 1;
2628
2629                 default:
2630                         return 1;
2631                 }
2632         }
2633
2634 int ssl_check_serverhello_tlsext(SSL *s)
2635         {
2636         int ret=SSL_TLSEXT_ERR_NOACK;
2637         int al = SSL_AD_UNRECOGNIZED_NAME;
2638
2639 #ifndef OPENSSL_NO_EC
2640         /* If we are client and using an elliptic curve cryptography cipher
2641          * suite, then if server returns an EC point formats lists extension
2642          * it must contain uncompressed.
2643          */
2644         unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
2645         unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
2646         if ((s->tlsext_ecpointformatlist != NULL) && (s->tlsext_ecpointformatlist_length > 0) &&
2647             (s->session->tlsext_ecpointformatlist != NULL) && (s->session->tlsext_ecpointformatlist_length > 0) &&
2648             ((alg_k & (SSL_kEECDH|SSL_kECDHr|SSL_kECDHe)) || (alg_a & SSL_aECDSA)))
2649                 {
2650                 /* we are using an ECC cipher */
2651                 size_t i;
2652                 unsigned char *list;
2653                 int found_uncompressed = 0;
2654                 list = s->session->tlsext_ecpointformatlist;
2655                 for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
2656                         {
2657                         if (*(list++) == TLSEXT_ECPOINTFORMAT_uncompressed)
2658                                 {
2659                                 found_uncompressed = 1;
2660                                 break;
2661                                 }
2662                         }
2663                 if (!found_uncompressed)
2664                         {
2665                         OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
2666                         return -1;
2667                         }
2668                 }
2669         ret = SSL_TLSEXT_ERR_OK;
2670 #endif /* OPENSSL_NO_EC */
2671
2672         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
2673                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
2674         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
2675                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
2676
2677         /* If we've requested certificate status and we wont get one
2678          * tell the callback
2679          */
2680         if ((s->tlsext_status_type != -1) && !(s->tlsext_status_expected)
2681                         && s->ctx && s->ctx->tlsext_status_cb)
2682                 {
2683                 int r;
2684                 /* Set resp to NULL, resplen to -1 so callback knows
2685                  * there is no response.
2686                  */
2687                 if (s->tlsext_ocsp_resp)
2688                         {
2689                         OPENSSL_free(s->tlsext_ocsp_resp);
2690                         s->tlsext_ocsp_resp = NULL;
2691                         }
2692                 s->tlsext_ocsp_resplen = -1;
2693                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
2694                 if (r == 0)
2695                         {
2696                         al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
2697                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
2698                         }
2699                 if (r < 0)
2700                         {
2701                         al = SSL_AD_INTERNAL_ERROR;
2702                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
2703                         }
2704                 }
2705
2706         switch (ret)
2707                 {
2708                 case SSL_TLSEXT_ERR_ALERT_FATAL:
2709                         ssl3_send_alert(s,SSL3_AL_FATAL,al);
2710                         return -1;
2711
2712                 case SSL_TLSEXT_ERR_ALERT_WARNING:
2713                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
2714                         return 1;
2715
2716                 case SSL_TLSEXT_ERR_NOACK:
2717                         s->servername_done=0;
2718                         default:
2719                 return 1;
2720                 }
2721         }
2722
2723 int ssl_parse_serverhello_tlsext(SSL *s, CBS *cbs)
2724         {
2725         int alert = -1;
2726         if (s->version < SSL3_VERSION)
2727                 return 1;
2728
2729         if (ssl_scan_serverhello_tlsext(s, cbs, &alert) <= 0)
2730                 {
2731                 ssl3_send_alert(s, SSL3_AL_FATAL, alert);
2732                 return 0;
2733                 }
2734
2735         if (ssl_check_serverhello_tlsext(s) <= 0)
2736                 {
2737                 OPENSSL_PUT_ERROR(SSL, ssl_parse_serverhello_tlsext, SSL_R_SERVERHELLO_TLSEXT);
2738                 return 0;
2739                 }
2740
2741         return 1;
2742         }
2743
2744 /* Since the server cache lookup is done early on in the processing of the
2745  * ClientHello, and other operations depend on the result, we need to handle
2746  * any TLS session ticket extension at the same time.
2747  *
2748  *   ctx: contains the early callback context, which is the result of a
2749  *       shallow parse of the ClientHello.
2750  *   ret: (output) on return, if a ticket was decrypted, then this is set to
2751  *       point to the resulting session.
2752  *
2753  * If s->tls_session_secret_cb is set then we are expecting a pre-shared key
2754  * ciphersuite, in which case we have no use for session tickets and one will
2755  * never be decrypted, nor will s->tlsext_ticket_expected be set to 1.
2756  *
2757  * Returns:
2758  *   -1: fatal error, either from parsing or decrypting the ticket.
2759  *    0: no ticket was found (or was ignored, based on settings).
2760  *    1: a zero length extension was found, indicating that the client supports
2761  *       session tickets but doesn't currently have one to offer.
2762  *    2: either s->tls_session_secret_cb was set, or a ticket was offered but
2763  *       couldn't be decrypted because of a non-fatal error.
2764  *    3: a ticket was successfully decrypted and *ret was set.
2765  *
2766  * Side effects:
2767  *   Sets s->tlsext_ticket_expected to 1 if the server will have to issue
2768  *   a new session ticket to the client because the client indicated support
2769  *   (and s->tls_session_secret_cb is NULL) but the client either doesn't have
2770  *   a session ticket or we couldn't use the one it gave us, or if
2771  *   s->ctx->tlsext_ticket_key_cb asked to renew the client's ticket.
2772  *   Otherwise, s->tlsext_ticket_expected is set to 0.
2773  */
2774 int tls1_process_ticket(SSL *s, const struct ssl_early_callback_ctx *ctx,
2775                         SSL_SESSION **ret)
2776         {
2777         *ret = NULL;
2778         s->tlsext_ticket_expected = 0;
2779         const unsigned char *data;
2780         size_t len;
2781         int r;
2782
2783         /* If tickets disabled behave as if no ticket present
2784          * to permit stateful resumption.
2785          */
2786         if (SSL_get_options(s) & SSL_OP_NO_TICKET)
2787                 return 0;
2788         if ((s->version <= SSL3_VERSION) && !ctx->extensions)
2789                 return 0;
2790         if (!SSL_early_callback_ctx_extension_get(
2791                 ctx, TLSEXT_TYPE_session_ticket, &data, &len))
2792                 {
2793                 return 0;
2794                 }
2795         if (len == 0)
2796                 {
2797                 /* The client will accept a ticket but doesn't
2798                  * currently have one. */
2799                 s->tlsext_ticket_expected = 1;
2800                 return 1;
2801                 }
2802         if (s->tls_session_secret_cb)
2803                 {
2804                 /* Indicate that the ticket couldn't be
2805                  * decrypted rather than generating the session
2806                  * from ticket now, trigger abbreviated
2807                  * handshake based on external mechanism to
2808                  * calculate the master secret later. */
2809                 return 2;
2810                 }
2811         r = tls_decrypt_ticket(s, data, len, ctx->session_id,
2812                                ctx->session_id_len, ret);
2813         switch (r)
2814                 {
2815                 case 2: /* ticket couldn't be decrypted */
2816                         s->tlsext_ticket_expected = 1;
2817                         return 2;
2818                 case 3: /* ticket was decrypted */
2819                         return r;
2820                 case 4: /* ticket decrypted but need to renew */
2821                         s->tlsext_ticket_expected = 1;
2822                         return 3;
2823                 default: /* fatal error */
2824                         return -1;
2825                 }
2826         }
2827
2828 /* tls_decrypt_ticket attempts to decrypt a session ticket.
2829  *
2830  *   etick: points to the body of the session ticket extension.
2831  *   eticklen: the length of the session tickets extenion.
2832  *   sess_id: points at the session ID.
2833  *   sesslen: the length of the session ID.
2834  *   psess: (output) on return, if a ticket was decrypted, then this is set to
2835  *       point to the resulting session.
2836  *
2837  * Returns:
2838  *   -1: fatal error, either from parsing or decrypting the ticket.
2839  *    2: the ticket couldn't be decrypted.
2840  *    3: a ticket was successfully decrypted and *psess was set.
2841  *    4: same as 3, but the ticket needs to be renewed.
2842  */
2843 static int tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen,
2844                                 const unsigned char *sess_id, int sesslen,
2845                                 SSL_SESSION **psess)
2846         {
2847         SSL_SESSION *sess;
2848         unsigned char *sdec;
2849         const unsigned char *p;
2850         int slen, mlen, renew_ticket = 0;
2851         unsigned char tick_hmac[EVP_MAX_MD_SIZE];
2852         HMAC_CTX hctx;
2853         EVP_CIPHER_CTX ctx;
2854         SSL_CTX *tctx = s->initial_ctx;
2855         /* Need at least keyname + iv + some encrypted data */
2856         if (eticklen < 48)
2857                 return 2;
2858         /* Initialize session ticket encryption and HMAC contexts */
2859         HMAC_CTX_init(&hctx);
2860         EVP_CIPHER_CTX_init(&ctx);
2861         if (tctx->tlsext_ticket_key_cb)
2862                 {
2863                 unsigned char *nctick = (unsigned char *)etick;
2864                 int rv = tctx->tlsext_ticket_key_cb(s, nctick, nctick + 16,
2865                                                         &ctx, &hctx, 0);
2866                 if (rv < 0)
2867                         return -1;
2868                 if (rv == 0)
2869                         return 2;
2870                 if (rv == 2)
2871                         renew_ticket = 1;
2872                 }
2873         else
2874                 {
2875                 /* Check key name matches */
2876                 if (memcmp(etick, tctx->tlsext_tick_key_name, 16))
2877                         return 2;
2878                 HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,
2879                                         tlsext_tick_md(), NULL);
2880                 EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
2881                                 tctx->tlsext_tick_aes_key, etick + 16);
2882                 }
2883         /* Attempt to process session ticket, first conduct sanity and
2884          * integrity checks on ticket.
2885          */
2886         mlen = HMAC_size(&hctx);
2887         if (mlen < 0)
2888                 {
2889                 EVP_CIPHER_CTX_cleanup(&ctx);
2890                 return -1;
2891                 }
2892         eticklen -= mlen;
2893         /* Check HMAC of encrypted ticket */
2894         HMAC_Update(&hctx, etick, eticklen);
2895         HMAC_Final(&hctx, tick_hmac, NULL);
2896         HMAC_CTX_cleanup(&hctx);
2897         if (CRYPTO_memcmp(tick_hmac, etick + eticklen, mlen))
2898                 return 2;
2899         /* Attempt to decrypt session data */
2900         /* Move p after IV to start of encrypted ticket, update length */
2901         p = etick + 16 + EVP_CIPHER_CTX_iv_length(&ctx);
2902         eticklen -= 16 + EVP_CIPHER_CTX_iv_length(&ctx);
2903         sdec = OPENSSL_malloc(eticklen);
2904         if (!sdec)
2905                 {
2906                 EVP_CIPHER_CTX_cleanup(&ctx);
2907                 return -1;
2908                 }
2909         EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen);
2910         if (EVP_DecryptFinal_ex(&ctx, sdec + slen, &mlen) <= 0)
2911                 {
2912                 EVP_CIPHER_CTX_cleanup(&ctx);
2913                 OPENSSL_free(sdec);
2914                 return 2;
2915                 }
2916         slen += mlen;
2917         EVP_CIPHER_CTX_cleanup(&ctx);
2918         p = sdec;
2919
2920         sess = d2i_SSL_SESSION(NULL, &p, slen);
2921         OPENSSL_free(sdec);
2922         if (sess)
2923                 {
2924                 /* The session ID, if non-empty, is used by some clients to
2925                  * detect that the ticket has been accepted. So we copy it to
2926                  * the session structure. If it is empty set length to zero
2927                  * as required by standard.
2928                  */
2929                 if (sesslen)
2930                         memcpy(sess->session_id, sess_id, sesslen);
2931                 sess->session_id_length = sesslen;
2932                 *psess = sess;
2933                 if (renew_ticket)
2934                         return 4;
2935                 else
2936                         return 3;
2937                 }
2938         ERR_clear_error();
2939         /* For session parse failure, indicate that we need to send a new
2940          * ticket. */
2941         return 2;
2942         }
2943
2944 /* Tables to translate from NIDs to TLS v1.2 ids */
2945
2946 typedef struct
2947         {
2948         int nid;
2949         int id;
2950         } tls12_lookup;
2951
2952 static tls12_lookup tls12_md[] = {
2953         {NID_md5, TLSEXT_hash_md5},
2954         {NID_sha1, TLSEXT_hash_sha1},
2955         {NID_sha224, TLSEXT_hash_sha224},
2956         {NID_sha256, TLSEXT_hash_sha256},
2957         {NID_sha384, TLSEXT_hash_sha384},
2958         {NID_sha512, TLSEXT_hash_sha512}
2959 };
2960
2961 static tls12_lookup tls12_sig[] = {
2962         {EVP_PKEY_RSA, TLSEXT_signature_rsa},
2963         {EVP_PKEY_DSA, TLSEXT_signature_dsa},
2964         {EVP_PKEY_EC, TLSEXT_signature_ecdsa}
2965 };
2966
2967 static int tls12_find_id(int nid, tls12_lookup *table, size_t tlen)
2968         {
2969         size_t i;
2970         for (i = 0; i < tlen; i++)
2971                 {
2972                 if (table[i].nid == nid)
2973                         return table[i].id;
2974                 }
2975         return -1;
2976         }
2977
2978 static int tls12_find_nid(int id, tls12_lookup *table, size_t tlen)
2979         {
2980         size_t i;
2981         for (i = 0; i < tlen; i++)
2982                 {
2983                 if ((table[i].id) == id)
2984                         return table[i].nid;
2985                 }
2986         return NID_undef;
2987         }
2988
2989 int tls12_get_sigandhash(unsigned char *p, const EVP_PKEY *pk, const EVP_MD *md)
2990         {
2991         int sig_id, md_id;
2992         if (!md)
2993                 return 0;
2994         md_id = tls12_find_id(EVP_MD_type(md), tls12_md,
2995                                 sizeof(tls12_md)/sizeof(tls12_lookup));
2996         if (md_id == -1)
2997                 return 0;
2998         sig_id = tls12_get_sigid(pk);
2999         if (sig_id == -1)
3000                 return 0;
3001         p[0] = (unsigned char)md_id;
3002         p[1] = (unsigned char)sig_id;
3003         return 1;
3004         }
3005
3006 int tls12_get_sigid(const EVP_PKEY *pk)
3007         {
3008         return tls12_find_id(pk->type, tls12_sig,
3009                                 sizeof(tls12_sig)/sizeof(tls12_lookup));
3010         }
3011
3012 const EVP_MD *tls12_get_hash(unsigned char hash_alg)
3013         {
3014         switch(hash_alg)
3015                 {
3016 #ifndef OPENSSL_NO_MD5
3017                 case TLSEXT_hash_md5:
3018                 return EVP_md5();
3019 #endif
3020 #ifndef OPENSSL_NO_SHA
3021                 case TLSEXT_hash_sha1:
3022                 return EVP_sha1();
3023 #endif
3024                 case TLSEXT_hash_sha224:
3025                 return EVP_sha224();
3026
3027                 case TLSEXT_hash_sha256:
3028                 return EVP_sha256();
3029                 case TLSEXT_hash_sha384:
3030                 return EVP_sha384();
3031
3032                 case TLSEXT_hash_sha512:
3033                 return EVP_sha512();
3034                 default:
3035                 return NULL;
3036
3037                 }
3038         }
3039
3040 static int tls12_get_pkey_idx(unsigned char sig_alg)
3041         {
3042         switch(sig_alg)
3043                 {
3044         case TLSEXT_signature_rsa:
3045                 return SSL_PKEY_RSA_SIGN;
3046 #ifndef OPENSSL_NO_DSA
3047         case TLSEXT_signature_dsa:
3048                 return SSL_PKEY_DSA_SIGN;
3049 #endif
3050 #ifndef OPENSSL_NO_ECDSA
3051         case TLSEXT_signature_ecdsa:
3052                 return SSL_PKEY_ECC;
3053 #endif
3054                 }
3055         return -1;
3056         }
3057
3058 /* Convert TLS 1.2 signature algorithm extension values into NIDs */
3059 static void tls1_lookup_sigalg(int *phash_nid, int *psign_nid,
3060                         int *psignhash_nid, const unsigned char *data)
3061         {
3062         int sign_nid = 0, hash_nid = 0;
3063         if (!phash_nid && !psign_nid && !psignhash_nid)
3064                 return;
3065         if (phash_nid || psignhash_nid)
3066                 {
3067                 hash_nid = tls12_find_nid(data[0], tls12_md,
3068                                         sizeof(tls12_md)/sizeof(tls12_lookup));
3069                 if (phash_nid)
3070                         *phash_nid = hash_nid;
3071                 }
3072         if (psign_nid || psignhash_nid)
3073                 {
3074                 sign_nid = tls12_find_nid(data[1], tls12_sig,
3075                                         sizeof(tls12_sig)/sizeof(tls12_lookup));
3076                 if (psign_nid)
3077                         *psign_nid = sign_nid;
3078                 }
3079         if (psignhash_nid)
3080                 {
3081                 if (sign_nid && hash_nid)
3082                         OBJ_find_sigid_by_algs(psignhash_nid,
3083                                                         hash_nid, sign_nid);
3084                 else
3085                         *psignhash_nid = NID_undef;
3086                 }
3087         }
3088 /* Given preference and allowed sigalgs set shared sigalgs */
3089 static int tls12_do_shared_sigalgs(TLS_SIGALGS *shsig,
3090                                 const unsigned char *pref, size_t preflen,
3091                                 const unsigned char *allow, size_t allowlen)
3092         {
3093         const unsigned char *ptmp, *atmp;
3094         size_t i, j, nmatch = 0;
3095         for (i = 0, ptmp = pref; i < preflen; i+=2, ptmp+=2)
3096                 {
3097                 /* Skip disabled hashes or signature algorithms */
3098                 if (tls12_get_hash(ptmp[0]) == NULL)
3099                         continue;
3100                 if (tls12_get_pkey_idx(ptmp[1]) == -1)
3101                         continue;
3102                 for (j = 0, atmp = allow; j < allowlen; j+=2, atmp+=2)
3103                         {
3104                         if (ptmp[0] == atmp[0] && ptmp[1] == atmp[1])
3105                                 {
3106                                 nmatch++;
3107                                 if (shsig)
3108                                         {
3109                                         shsig->rhash = ptmp[0];
3110                                         shsig->rsign = ptmp[1];
3111                                         tls1_lookup_sigalg(&shsig->hash_nid,
3112                                                 &shsig->sign_nid,
3113                                                 &shsig->signandhash_nid,
3114                                                 ptmp);
3115                                         shsig++;
3116                                         }
3117                                 break;
3118                                 }
3119                         }
3120                 }
3121         return nmatch;
3122         }
3123
3124 /* Set shared signature algorithms for SSL structures */
3125 static int tls1_set_shared_sigalgs(SSL *s)
3126         {
3127         const unsigned char *pref, *allow, *conf;
3128         size_t preflen, allowlen, conflen;
3129         size_t nmatch;
3130         TLS_SIGALGS *salgs = NULL;
3131         CERT *c = s->cert;
3132         unsigned int is_suiteb = tls1_suiteb(s);
3133         if (c->shared_sigalgs)
3134                 {
3135                 OPENSSL_free(c->shared_sigalgs);
3136                 c->shared_sigalgs = NULL;
3137                 }
3138         /* If client use client signature algorithms if not NULL */
3139         if (!s->server && c->client_sigalgs && !is_suiteb)
3140                 {
3141                 conf = c->client_sigalgs;
3142                 conflen = c->client_sigalgslen;
3143                 }
3144         else if (c->conf_sigalgs && !is_suiteb)
3145                 {
3146                 conf = c->conf_sigalgs;
3147                 conflen = c->conf_sigalgslen;
3148                 }
3149         else
3150                 conflen = tls12_get_psigalgs(s, &conf);
3151         if(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE || is_suiteb)
3152                 {
3153                 pref = conf;
3154                 preflen = conflen;
3155                 allow = c->peer_sigalgs;
3156                 allowlen = c->peer_sigalgslen;
3157                 }
3158         else
3159                 {
3160                 allow = conf;
3161                 allowlen = conflen;
3162                 pref = c->peer_sigalgs;
3163                 preflen = c->peer_sigalgslen;
3164                 }
3165         nmatch = tls12_do_shared_sigalgs(NULL, pref, preflen, allow, allowlen);
3166         if (!nmatch)
3167                 return 1;
3168         salgs = OPENSSL_malloc(nmatch * sizeof(TLS_SIGALGS));
3169         if (!salgs)
3170                 return 0;
3171         nmatch = tls12_do_shared_sigalgs(salgs, pref, preflen, allow, allowlen);
3172         c->shared_sigalgs = salgs;
3173         c->shared_sigalgslen = nmatch;
3174         return 1;
3175         }
3176
3177
3178 /* Set preferred digest for each key type */
3179
3180 int tls1_process_sigalgs(SSL *s, const CBS *sigalgs)
3181         {
3182         int idx;
3183         size_t i;
3184         const EVP_MD *md;
3185         CERT *c = s->cert;
3186         TLS_SIGALGS *sigptr;
3187
3188         /* Extension ignored for inappropriate versions */
3189         if (!SSL_USE_SIGALGS(s))
3190                 return 1;
3191         /* Length must be even */
3192         if (CBS_len(sigalgs) % 2 != 0)
3193                 return 0;
3194         /* Should never happen */
3195         if (!c)
3196                 return 0;
3197
3198         if (!CBS_stow(sigalgs, &c->peer_sigalgs, &c->peer_sigalgslen))
3199                 return 0;
3200
3201         tls1_set_shared_sigalgs(s);
3202
3203 #ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
3204         if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTOCOL)
3205                 {
3206                 /* Use first set signature preference to force message
3207                  * digest, ignoring any peer preferences.
3208                  */
3209                 const unsigned char *sigs = NULL;
3210                 if (s->server)
3211                         sigs = c->conf_sigalgs;
3212                 else
3213                         sigs = c->client_sigalgs;
3214                 if (sigs)
3215                         {
3216                         idx = tls12_get_pkey_idx(sigs[1]);
3217                         md = tls12_get_hash(sigs[0]);
3218                         c->pkeys[idx].digest = md;
3219                         c->pkeys[idx].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
3220                         if (idx == SSL_PKEY_RSA_SIGN)
3221                                 {
3222                                 c->pkeys[SSL_PKEY_RSA_ENC].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
3223                                 c->pkeys[SSL_PKEY_RSA_ENC].digest = md;
3224                                 }
3225                         }
3226                 }
3227 #endif
3228
3229         for (i = 0, sigptr = c->shared_sigalgs;
3230                         i < c->shared_sigalgslen; i++, sigptr++)
3231                 {
3232                 idx = tls12_get_pkey_idx(sigptr->rsign);
3233                 if (idx > 0 && c->pkeys[idx].digest == NULL)
3234                         {
3235                         md = tls12_get_hash(sigptr->rhash);
3236                         c->pkeys[idx].digest = md;
3237                         c->pkeys[idx].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
3238                         if (idx == SSL_PKEY_RSA_SIGN)
3239                                 {
3240                                 c->pkeys[SSL_PKEY_RSA_ENC].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
3241                                 c->pkeys[SSL_PKEY_RSA_ENC].digest = md;
3242                                 }
3243                         }
3244
3245                 }
3246         /* In strict mode leave unset digests as NULL to indicate we can't
3247          * use the certificate for signing.
3248          */
3249         if (!(s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT))
3250                 {
3251                 /* Set any remaining keys to default values. NOTE: if alg is
3252                  * not supported it stays as NULL.
3253                  */
3254 #ifndef OPENSSL_NO_DSA
3255                 if (!c->pkeys[SSL_PKEY_DSA_SIGN].digest)
3256                         c->pkeys[SSL_PKEY_DSA_SIGN].digest = EVP_sha1();
3257 #endif
3258                 if (!c->pkeys[SSL_PKEY_RSA_SIGN].digest)
3259                         {
3260                         c->pkeys[SSL_PKEY_RSA_SIGN].digest = EVP_sha1();
3261                         c->pkeys[SSL_PKEY_RSA_ENC].digest = EVP_sha1();
3262                         }
3263 #ifndef OPENSSL_NO_ECDSA
3264                 if (!c->pkeys[SSL_PKEY_ECC].digest)
3265                         c->pkeys[SSL_PKEY_ECC].digest = EVP_sha1();
3266 #endif
3267                 }
3268         return 1;
3269         }
3270
3271
3272 int SSL_get_sigalgs(SSL *s, int idx,
3273                         int *psign, int *phash, int *psignhash,
3274                         unsigned char *rsig, unsigned char *rhash)
3275         {
3276         const unsigned char *psig = s->cert->peer_sigalgs;
3277         if (psig == NULL)
3278                 return 0;
3279         if (idx >= 0)
3280                 {
3281                 idx <<= 1;
3282                 if (idx >= (int)s->cert->peer_sigalgslen)
3283                         return 0;
3284                 psig += idx;
3285                 if (rhash)
3286                         *rhash = psig[0];
3287                 if (rsig)
3288                         *rsig = psig[1];
3289                 tls1_lookup_sigalg(phash, psign, psignhash, psig);
3290                 }
3291         return s->cert->peer_sigalgslen / 2;
3292         }
3293
3294 int SSL_get_shared_sigalgs(SSL *s, int idx,
3295                         int *psign, int *phash, int *psignhash,
3296                         unsigned char *rsig, unsigned char *rhash)
3297         {
3298         TLS_SIGALGS *shsigalgs = s->cert->shared_sigalgs;
3299         if (!shsigalgs || idx >= (int)s->cert->shared_sigalgslen)
3300                 return 0;
3301         shsigalgs += idx;
3302         if (phash)
3303                 *phash = shsigalgs->hash_nid;
3304         if (psign)
3305                 *psign = shsigalgs->sign_nid;
3306         if (psignhash)
3307                 *psignhash = shsigalgs->signandhash_nid;
3308         if (rsig)
3309                 *rsig = shsigalgs->rsign;
3310         if (rhash)
3311                 *rhash = shsigalgs->rhash;
3312         return s->cert->shared_sigalgslen;
3313         }
3314
3315 /* tls1_channel_id_hash calculates the signed data for a Channel ID on the given
3316  * SSL connection and writes it to |md|. */
3317 int
3318 tls1_channel_id_hash(EVP_MD_CTX *md, SSL *s)
3319         {
3320         EVP_MD_CTX ctx;
3321         unsigned char temp_digest[EVP_MAX_MD_SIZE];
3322         unsigned temp_digest_len;
3323         int i;
3324         static const char kClientIDMagic[] = "TLS Channel ID signature";
3325
3326         if (s->s3->handshake_buffer)
3327                 if (!ssl3_digest_cached_records(s))
3328                         return 0;
3329
3330         EVP_DigestUpdate(md, kClientIDMagic, sizeof(kClientIDMagic));
3331
3332         if (s->hit && s->s3->tlsext_channel_id_new)
3333                 {
3334                 static const char kResumptionMagic[] = "Resumption";
3335                 EVP_DigestUpdate(md, kResumptionMagic,
3336                                  sizeof(kResumptionMagic));
3337                 if (s->session->original_handshake_hash_len == 0)
3338                         return 0;
3339                 EVP_DigestUpdate(md, s->session->original_handshake_hash,
3340                                  s->session->original_handshake_hash_len);
3341                 }
3342
3343         EVP_MD_CTX_init(&ctx);
3344         for (i = 0; i < SSL_MAX_DIGEST; i++)
3345                 {
3346                 if (s->s3->handshake_dgst[i] == NULL)
3347                         continue;
3348                 EVP_MD_CTX_copy_ex(&ctx, s->s3->handshake_dgst[i]);
3349                 EVP_DigestFinal_ex(&ctx, temp_digest, &temp_digest_len);
3350                 EVP_DigestUpdate(md, temp_digest, temp_digest_len);
3351                 }
3352         EVP_MD_CTX_cleanup(&ctx);
3353
3354         return 1;
3355         }
3356
3357 /* tls1_record_handshake_hashes_for_channel_id records the current handshake
3358  * hashes in |s->session| so that Channel ID resumptions can sign that data. */
3359 int tls1_record_handshake_hashes_for_channel_id(SSL *s)
3360         {
3361         int digest_len;
3362         /* This function should never be called for a resumed session because
3363          * the handshake hashes that we wish to record are for the original,
3364          * full handshake. */
3365         if (s->hit)
3366                 return -1;
3367         /* It only makes sense to call this function if Channel IDs have been
3368          * negotiated. */
3369         if (!s->s3->tlsext_channel_id_new)
3370                 return -1;
3371
3372         digest_len = tls1_handshake_digest(
3373                 s, s->session->original_handshake_hash,
3374                 sizeof(s->session->original_handshake_hash));
3375         if (digest_len < 0)
3376                 return -1;
3377
3378         s->session->original_handshake_hash_len = digest_len;
3379
3380         return 1;
3381         }
3382
3383 /* TODO(fork): remove */
3384 #if 0
3385 #define MAX_SIGALGLEN   (TLSEXT_hash_num * TLSEXT_signature_num * 2)
3386
3387 typedef struct
3388         {
3389         size_t sigalgcnt;
3390         int sigalgs[MAX_SIGALGLEN];
3391         } sig_cb_st;
3392
3393 static int sig_cb(const char *elem, int len, void *arg)
3394         {
3395         sig_cb_st *sarg = arg;
3396         size_t i;
3397         char etmp[20], *p;
3398         int sig_alg, hash_alg;
3399         if (sarg->sigalgcnt == MAX_SIGALGLEN)
3400                 return 0;
3401         if (len > (int)(sizeof(etmp) - 1))
3402                 return 0;
3403         memcpy(etmp, elem, len);
3404         etmp[len] = 0;
3405         p = strchr(etmp, '+');
3406         if (!p)
3407                 return 0;
3408         *p = 0;
3409         p++;
3410         if (!*p)
3411                 return 0;
3412
3413         if (!strcmp(etmp, "RSA"))
3414                 sig_alg = EVP_PKEY_RSA;
3415         else if (!strcmp(etmp, "DSA"))
3416                 sig_alg = EVP_PKEY_DSA;
3417         else if (!strcmp(etmp, "ECDSA"))
3418                 sig_alg = EVP_PKEY_EC;
3419         else return 0;
3420
3421         hash_alg = OBJ_sn2nid(p);
3422         if (hash_alg == NID_undef)
3423                 hash_alg = OBJ_ln2nid(p);
3424         if (hash_alg == NID_undef)
3425                 return 0;
3426
3427         for (i = 0; i < sarg->sigalgcnt; i+=2)
3428                 {
3429                 if (sarg->sigalgs[i] == sig_alg
3430                         && sarg->sigalgs[i + 1] == hash_alg)
3431                         return 0;
3432                 }
3433         sarg->sigalgs[sarg->sigalgcnt++] = hash_alg;
3434         sarg->sigalgs[sarg->sigalgcnt++] = sig_alg;
3435         return 1;
3436         }
3437
3438 /* Set suppored signature algorithms based on a colon separated list
3439  * of the form sig+hash e.g. RSA+SHA512:DSA+SHA512 */
3440 int tls1_set_sigalgs_list(CERT *c, const char *str, int client)
3441         {
3442         sig_cb_st sig;
3443         sig.sigalgcnt = 0;
3444         if (!CONF_parse_list(str, ':', 1, sig_cb, &sig))
3445                 return 0;
3446         if (c == NULL)
3447                 return 1;
3448         return tls1_set_sigalgs(c, sig.sigalgs, sig.sigalgcnt, client);
3449         }
3450 #endif
3451
3452 int tls1_set_sigalgs(CERT *c, const int *psig_nids, size_t salglen, int client)
3453         {
3454         unsigned char *sigalgs, *sptr;
3455         int rhash, rsign;
3456         size_t i;
3457         if (salglen & 1)
3458                 return 0;
3459         sigalgs = OPENSSL_malloc(salglen);
3460         if (sigalgs == NULL)
3461                 return 0;
3462         for (i = 0, sptr = sigalgs; i < salglen; i+=2)
3463                 {
3464                 rhash = tls12_find_id(*psig_nids++, tls12_md,
3465                                         sizeof(tls12_md)/sizeof(tls12_lookup));
3466                 rsign = tls12_find_id(*psig_nids++, tls12_sig,
3467                                 sizeof(tls12_sig)/sizeof(tls12_lookup));
3468
3469                 if (rhash == -1 || rsign == -1)
3470                         goto err;
3471                 *sptr++ = rhash;
3472                 *sptr++ = rsign;
3473                 }
3474
3475         if (client)
3476                 {
3477                 if (c->client_sigalgs)
3478                         OPENSSL_free(c->client_sigalgs);
3479                 c->client_sigalgs = sigalgs;
3480                 c->client_sigalgslen = salglen;
3481                 }
3482         else
3483                 {
3484                 if (c->conf_sigalgs)
3485                         OPENSSL_free(c->conf_sigalgs);
3486                 c->conf_sigalgs = sigalgs;
3487                 c->conf_sigalgslen = salglen;
3488                 }
3489
3490         return 1;
3491
3492         err:
3493         OPENSSL_free(sigalgs);
3494         return 0;
3495         }
3496
3497 static int tls1_check_sig_alg(CERT *c, X509 *x, int default_nid)
3498         {
3499         int sig_nid;
3500         size_t i;
3501         if (default_nid == -1)
3502                 return 1;
3503         sig_nid = X509_get_signature_nid(x);
3504         if (default_nid)
3505                 return sig_nid == default_nid ? 1 : 0;
3506         for (i = 0; i < c->shared_sigalgslen; i++)
3507                 if (sig_nid == c->shared_sigalgs[i].signandhash_nid)
3508                         return 1;
3509         return 0;
3510         }
3511 /* Check to see if a certificate issuer name matches list of CA names */
3512 static int ssl_check_ca_name(STACK_OF(X509_NAME) *names, X509 *x)
3513         {
3514         X509_NAME *nm;
3515         int i;
3516         nm = X509_get_issuer_name(x);
3517         for (i = 0; i < sk_X509_NAME_num(names); i++)
3518                 {
3519                 if(!X509_NAME_cmp(nm, sk_X509_NAME_value(names, i)))
3520                         return 1;
3521                 }
3522         return 0;
3523         }
3524
3525 /* Check certificate chain is consistent with TLS extensions and is
3526  * usable by server. This servers two purposes: it allows users to
3527  * check chains before passing them to the server and it allows the
3528  * server to check chains before attempting to use them.
3529  */
3530
3531 /* Flags which need to be set for a certificate when stict mode not set */
3532
3533 #define CERT_PKEY_VALID_FLAGS \
3534         (CERT_PKEY_EE_SIGNATURE|CERT_PKEY_EE_PARAM)
3535 /* Strict mode flags */
3536 #define CERT_PKEY_STRICT_FLAGS \
3537          (CERT_PKEY_VALID_FLAGS|CERT_PKEY_CA_SIGNATURE|CERT_PKEY_CA_PARAM \
3538          | CERT_PKEY_ISSUER_NAME|CERT_PKEY_CERT_TYPE)
3539
3540 int tls1_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain,
3541                                                                         int idx)
3542         {
3543         int i;
3544         int rv = 0;
3545         int check_flags = 0, strict_mode;
3546         CERT_PKEY *cpk = NULL;
3547         CERT *c = s->cert;
3548         unsigned int suiteb_flags = tls1_suiteb(s);
3549         /* idx == -1 means checking server chains */
3550         if (idx != -1)
3551                 {
3552                 /* idx == -2 means checking client certificate chains */
3553                 if (idx == -2)
3554                         {
3555                         cpk = c->key;
3556                         idx = cpk - c->pkeys;
3557                         }
3558                 else
3559                         cpk = c->pkeys + idx;
3560                 x = cpk->x509;
3561                 pk = cpk->privatekey;
3562                 chain = cpk->chain;
3563                 strict_mode = c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT;
3564                 /* If no cert or key, forget it */
3565                 if (!x || !pk)
3566                         goto end;
3567 #ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
3568                 /* Allow any certificate to pass test */
3569                 if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTOCOL)
3570                         {
3571                         rv = CERT_PKEY_STRICT_FLAGS|CERT_PKEY_EXPLICIT_SIGN|CERT_PKEY_VALID|CERT_PKEY_SIGN;
3572                         cpk->valid_flags = rv;
3573                         return rv;
3574                         }
3575 #endif
3576                 }
3577         else
3578                 {
3579                 if (!x || !pk)
3580                         goto end;
3581                 idx = ssl_cert_type(x, pk);
3582                 if (idx == -1)
3583                         goto end;
3584                 cpk = c->pkeys + idx;
3585                 if (c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)
3586                         check_flags = CERT_PKEY_STRICT_FLAGS;
3587                 else
3588                         check_flags = CERT_PKEY_VALID_FLAGS;
3589                 strict_mode = 1;
3590                 }
3591
3592         if (suiteb_flags)
3593                 {
3594                 int ok;
3595                 if (check_flags)
3596                         check_flags |= CERT_PKEY_SUITEB;
3597                 ok = X509_chain_check_suiteb(NULL, x, chain, suiteb_flags);
3598                 if (ok != X509_V_OK)
3599                         {
3600                         if (check_flags)
3601                                 rv |= CERT_PKEY_SUITEB;
3602                         else
3603                                 goto end;
3604                         }
3605                 }
3606
3607         /* Check all signature algorithms are consistent with
3608          * signature algorithms extension if TLS 1.2 or later
3609          * and strict mode.
3610          */
3611         if (TLS1_get_version(s) >= TLS1_2_VERSION && strict_mode)
3612                 {
3613                 int default_nid;
3614                 unsigned char rsign = 0;
3615                 if (c->peer_sigalgs)
3616                         default_nid = 0;
3617                 /* If no sigalgs extension use defaults from RFC5246 */
3618                 else
3619                         {
3620                         switch(idx)
3621                                 {
3622                         case SSL_PKEY_RSA_ENC:
3623                         case SSL_PKEY_RSA_SIGN:
3624                         case SSL_PKEY_DH_RSA:
3625                                 rsign = TLSEXT_signature_rsa;
3626                                 default_nid = NID_sha1WithRSAEncryption;
3627                                 break;
3628
3629                         case SSL_PKEY_DSA_SIGN:
3630                         case SSL_PKEY_DH_DSA:
3631                                 rsign = TLSEXT_signature_dsa;
3632                                 default_nid = NID_dsaWithSHA1;
3633                                 break;
3634
3635                         case SSL_PKEY_ECC:
3636                                 rsign = TLSEXT_signature_ecdsa;
3637                                 default_nid = NID_ecdsa_with_SHA1;
3638                                 break;
3639
3640                         default:
3641                                 default_nid = -1;
3642                                 break;
3643                                 }
3644                         }
3645                 /* If peer sent no signature algorithms extension and we
3646                  * have set preferred signature algorithms check we support
3647                  * sha1.
3648                  */
3649                 if (default_nid > 0 && c->conf_sigalgs)
3650                         {
3651                         size_t j;
3652                         const unsigned char *p = c->conf_sigalgs;
3653                         for (j = 0; j < c->conf_sigalgslen; j += 2, p += 2)
3654                                 {
3655                                 if (p[0] == TLSEXT_hash_sha1 && p[1] == rsign)
3656                                         break;
3657                                 }
3658                         if (j == c->conf_sigalgslen)
3659                                 {
3660                                 if (check_flags)
3661                                         goto skip_sigs;
3662                                 else
3663                                         goto end;
3664                                 }
3665                         }
3666                 /* Check signature algorithm of each cert in chain */
3667                 if (!tls1_check_sig_alg(c, x, default_nid))
3668                         {
3669                         if (!check_flags) goto end;
3670                         }
3671                 else
3672                         rv |= CERT_PKEY_EE_SIGNATURE;
3673                 rv |= CERT_PKEY_CA_SIGNATURE;
3674                 for (i = 0; i < sk_X509_num(chain); i++)
3675                         {
3676                         if (!tls1_check_sig_alg(c, sk_X509_value(chain, i),
3677                                                         default_nid))
3678                                 {
3679                                 if (check_flags)
3680                                         {
3681                                         rv &= ~CERT_PKEY_CA_SIGNATURE;
3682                                         break;
3683                                         }
3684                                 else
3685                                         goto end;
3686                                 }
3687                         }
3688                 }
3689         /* Else not TLS 1.2, so mark EE and CA signing algorithms OK */
3690         else if(check_flags)
3691                 rv |= CERT_PKEY_EE_SIGNATURE|CERT_PKEY_CA_SIGNATURE;
3692         skip_sigs:
3693         /* Check cert parameters are consistent */
3694         if (tls1_check_cert_param(s, x, check_flags ? 1 : 2))
3695                 rv |= CERT_PKEY_EE_PARAM;
3696         else if (!check_flags)
3697                 goto end;
3698         if (!s->server)
3699                 rv |= CERT_PKEY_CA_PARAM;
3700         /* In strict mode check rest of chain too */
3701         else if (strict_mode)
3702                 {
3703                 rv |= CERT_PKEY_CA_PARAM;
3704                 for (i = 0; i < sk_X509_num(chain); i++)
3705                         {
3706                         X509 *ca = sk_X509_value(chain, i);
3707                         if (!tls1_check_cert_param(s, ca, 0))
3708                                 {
3709                                 if (check_flags)
3710                                         {
3711                                         rv &= ~CERT_PKEY_CA_PARAM;
3712                                         break;
3713                                         }
3714                                 else
3715                                         goto end;
3716                                 }
3717                         }
3718                 }
3719         if (!s->server && strict_mode)
3720                 {
3721                 STACK_OF(X509_NAME) *ca_dn;
3722                 uint8_t check_type = 0;
3723                 switch (pk->type)
3724                         {
3725                 case EVP_PKEY_RSA:
3726                         check_type = TLS_CT_RSA_SIGN;
3727                         break;
3728                 case EVP_PKEY_DSA:
3729                         check_type = TLS_CT_DSS_SIGN;
3730                         break;
3731                 case EVP_PKEY_EC:
3732                         check_type = TLS_CT_ECDSA_SIGN;
3733                         break;
3734                 case EVP_PKEY_DH:
3735                 case EVP_PKEY_DHX:
3736                                 {
3737                                 int cert_type = X509_certificate_type(x, pk);
3738                                 if (cert_type & EVP_PKS_RSA)
3739                                         check_type = TLS_CT_RSA_FIXED_DH;
3740                                 if (cert_type & EVP_PKS_DSA)
3741                                         check_type = TLS_CT_DSS_FIXED_DH;
3742                                 }
3743                         }
3744                 if (check_type)
3745                         {
3746                         if (s->s3->tmp.certificate_types &&
3747                                 memchr(s->s3->tmp.certificate_types, check_type, s->s3->tmp.num_certificate_types))
3748                                 {
3749                                         rv |= CERT_PKEY_CERT_TYPE;
3750                                 }
3751                         if (!(rv & CERT_PKEY_CERT_TYPE) && !check_flags)
3752                                 goto end;
3753                         }
3754                 else
3755                         rv |= CERT_PKEY_CERT_TYPE;
3756
3757
3758                 ca_dn = s->s3->tmp.ca_names;
3759
3760                 if (!sk_X509_NAME_num(ca_dn))
3761                         rv |= CERT_PKEY_ISSUER_NAME;
3762
3763                 if (!(rv & CERT_PKEY_ISSUER_NAME))
3764                         {
3765                         if (ssl_check_ca_name(ca_dn, x))
3766                                 rv |= CERT_PKEY_ISSUER_NAME;
3767                         }
3768                 if (!(rv & CERT_PKEY_ISSUER_NAME))
3769                         {
3770                         for (i = 0; i < sk_X509_num(chain); i++)
3771                                 {
3772                                 X509 *xtmp = sk_X509_value(chain, i);
3773                                 if (ssl_check_ca_name(ca_dn, xtmp))
3774                                         {
3775                                         rv |= CERT_PKEY_ISSUER_NAME;
3776                                         break;
3777                                         }
3778                                 }
3779                         }
3780                 if (!check_flags && !(rv & CERT_PKEY_ISSUER_NAME))
3781                         goto end;
3782                 }
3783         else
3784                 rv |= CERT_PKEY_ISSUER_NAME|CERT_PKEY_CERT_TYPE;
3785
3786         if (!check_flags || (rv & check_flags) == check_flags)
3787                 rv |= CERT_PKEY_VALID;
3788
3789         end:
3790
3791         if (TLS1_get_version(s) >= TLS1_2_VERSION)
3792                 {
3793                 if (cpk->valid_flags & CERT_PKEY_EXPLICIT_SIGN)
3794                         rv |= CERT_PKEY_EXPLICIT_SIGN|CERT_PKEY_SIGN;
3795                 else if (cpk->digest)
3796                         rv |= CERT_PKEY_SIGN;
3797                 }
3798         else
3799                 rv |= CERT_PKEY_SIGN|CERT_PKEY_EXPLICIT_SIGN;
3800
3801         /* When checking a CERT_PKEY structure all flags are irrelevant
3802          * if the chain is invalid.
3803          */
3804         if (!check_flags)
3805                 {
3806                 if (rv & CERT_PKEY_VALID)
3807                         cpk->valid_flags = rv;
3808                 else
3809                         {
3810                         /* Preserve explicit sign flag, clear rest */
3811                         cpk->valid_flags &= CERT_PKEY_EXPLICIT_SIGN;
3812                         return 0;
3813                         }
3814                 }
3815         return rv;
3816         }
3817
3818 /* Set validity of certificates in an SSL structure */
3819 void tls1_set_cert_validity(SSL *s)
3820         {
3821         tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA_ENC);
3822         tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA_SIGN);
3823         tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DSA_SIGN);
3824         tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DH_RSA);
3825         tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DH_DSA);
3826         tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_ECC);
3827         }
3828 /* User level utiity function to check a chain is suitable */
3829 int SSL_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain)
3830         {
3831         return tls1_check_chain(s, x, pk, chain, -1);
3832         }
3833