source4/heimdal/lib/krb5/ticket.c

   1 /*
   2  * Copyright (c) 1997 - 2001 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the Institute nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include "krb5_locl.h"
  37
  38 /**
  39  * Free ticket and content
  40  *
  41  * @param context a Kerberos 5 context
  42  * @param ticket ticket to free
  43  *
  44  * @return Returns 0 to indicate success.  Otherwise an kerberos et
  45  * error code is returned, see krb5_get_error_message().
  46  *
  47  * @ingroup krb5
  48  */
  49
  50 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
  51 krb5_free_ticket(krb5_context context,
  52                  krb5_ticket *ticket)
  53 {
  54     free_EncTicketPart(&ticket->ticket);
  55     krb5_free_principal(context, ticket->client);
  56     krb5_free_principal(context, ticket->server);
  57     free(ticket);
  58     return 0;
  59 }
  60
  61 /**
  62  * Copy ticket and content
  63  *
  64  * @param context a Kerberos 5 context
  65  * @param from ticket to copy
  66  * @param to new copy of ticket, free with krb5_free_ticket()
  67  *
  68  * @return Returns 0 to indicate success.  Otherwise an kerberos et
  69  * error code is returned, see krb5_get_error_message().
  70  *
  71  * @ingroup krb5
  72  */
  73
  74 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
  75 krb5_copy_ticket(krb5_context context,
  76                  const krb5_ticket *from,
  77                  krb5_ticket **to)
  78 {
  79     krb5_error_code ret;
  80     krb5_ticket *tmp;
  81
  82     *to = NULL;
  83     tmp = malloc(sizeof(*tmp));
  84     if(tmp == NULL) {
  85         krb5_set_error_message(context, ENOMEM,
  86                                N_("malloc: out of memory", ""));
  87         return ENOMEM;
  88     }
  89     if((ret = copy_EncTicketPart(&from->ticket, &tmp->ticket))){
  90         free(tmp);
  91         return ret;
  92     }
  93     ret = krb5_copy_principal(context, from->client, &tmp->client);
  94     if(ret){
  95         free_EncTicketPart(&tmp->ticket);
  96         free(tmp);
  97         return ret;
  98     }
  99     ret = krb5_copy_principal(context, from->server, &tmp->server);
 100     if(ret){
 101         krb5_free_principal(context, tmp->client);
 102         free_EncTicketPart(&tmp->ticket);
 103         free(tmp);
 104         return ret;
 105     }
 106     *to = tmp;
 107     return 0;
 108 }
 109
 110 /**
 111  * Return client principal in ticket
 112  *
 113  * @param context a Kerberos 5 context
 114  * @param ticket ticket to copy
 115  * @param client client principal, free with krb5_free_principal()
 116  *
 117  * @return Returns 0 to indicate success.  Otherwise an kerberos et
 118  * error code is returned, see krb5_get_error_message().
 119  *
 120  * @ingroup krb5
 121  */
 122
 123 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 124 krb5_ticket_get_client(krb5_context context,
 125                        const krb5_ticket *ticket,
 126                        krb5_principal *client)
 127 {
 128     return krb5_copy_principal(context, ticket->client, client);
 129 }
 130
 131 /**
 132  * Return server principal in ticket
 133  *
 134  * @param context a Kerberos 5 context
 135  * @param ticket ticket to copy
 136  * @param server server principal, free with krb5_free_principal()
 137  *
 138  * @return Returns 0 to indicate success.  Otherwise an kerberos et
 139  * error code is returned, see krb5_get_error_message().
 140  *
 141  * @ingroup krb5
 142  */
 143
 144 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 145 krb5_ticket_get_server(krb5_context context,
 146                        const krb5_ticket *ticket,
 147                        krb5_principal *server)
 148 {
 149     return krb5_copy_principal(context, ticket->server, server);
 150 }
 151
 152 /**
 153  * Return end time of ticket
 154  *
 155  * @param context a Kerberos 5 context
 156  * @param ticket ticket to copy
 157  *
 158  * @return end time of ticket
 159  *
 160  * @ingroup krb5
 161  */
 162
 163 KRB5_LIB_FUNCTION time_t KRB5_LIB_CALL
 164 krb5_ticket_get_endtime(krb5_context context,
 165                         const krb5_ticket *ticket)
 166 {
 167     return ticket->ticket.endtime;
 168 }
 169
 170 /**
 171  * Get the flags from the Kerberos ticket
 172  *
 173  * @param context Kerberos context
 174  * @param ticket Kerberos ticket
 175  *
 176  * @return ticket flags
 177  *
 178  * @ingroup krb5_ticket
 179  */
 180 unsigned long
 181 krb5_ticket_get_flags(krb5_context context,
 182                       const krb5_ticket *ticket)
 183 {
 184     return TicketFlags2int(ticket->ticket.flags);
 185 }
 186
 187 static int
 188 find_type_in_ad(krb5_context context,
 189                 int type,
 190                 krb5_data *data,
 191                 krb5_boolean *found,
 192                 krb5_boolean failp,
 193                 krb5_keyblock *sessionkey,
 194                 const AuthorizationData *ad,
 195                 int level)
 196 {
 197     krb5_error_code ret = 0;
 198     int i;
 199
 200     if (level > 9) {
 201         ret = ENOENT; /* XXX */
 202         krb5_set_error_message(context, ret,
 203                                N_("Authorization data nested deeper "
 204                                   "then %d levels, stop searching", ""),
 205                                level);
 206         goto out;
 207     }
 208
 209     /*
 210      * Only copy out the element the first time we get to it, we need
 211      * to run over the whole authorization data fields to check if
 212      * there are any container clases we need to care about.
 213      */
 214     for (i = 0; i < ad->len; i++) {
 215         if (!*found && ad->val[i].ad_type == type) {
 216             ret = der_copy_octet_string(&ad->val[i].ad_data, data);
 217             if (ret) {
 218                 krb5_set_error_message(context, ret,
 219                                        N_("malloc: out of memory", ""));
 220                 goto out;
 221             }
 222             *found = TRUE;
 223             continue;
 224         }
 225         switch (ad->val[i].ad_type) {
 226         case KRB5_AUTHDATA_IF_RELEVANT: {
 227             AuthorizationData child;
 228             ret = decode_AuthorizationData(ad->val[i].ad_data.data,
 229                                            ad->val[i].ad_data.length,
 230                                            &child,
 231                                            NULL);
 232             if (ret) {
 233                 krb5_set_error_message(context, ret,
 234                                        N_("Failed to decode "
 235                                           "IF_RELEVANT with %d", ""),
 236                                        (int)ret);
 237                 goto out;
 238             }
 239             ret = find_type_in_ad(context, type, data, found, FALSE,
 240                                   sessionkey, &child, level + 1);
 241             free_AuthorizationData(&child);
 242             if (ret)
 243                 goto out;
 244             break;
 245         }
 246 #if 0 /* XXX test */
 247         case KRB5_AUTHDATA_KDC_ISSUED: {
 248             AD_KDCIssued child;
 249
 250             ret = decode_AD_KDCIssued(ad->val[i].ad_data.data,
 251                                       ad->val[i].ad_data.length,
 252                                       &child,
 253                                       NULL);
 254             if (ret) {
 255                 krb5_set_error_message(context, ret,
 256                                        N_("Failed to decode "
 257                                           "AD_KDCIssued with %d", ""),
 258                                        ret);
 259                 goto out;
 260             }
 261             if (failp) {
 262                 krb5_boolean valid;
 263                 krb5_data buf;
 264                 size_t len;
 265
 266                 ASN1_MALLOC_ENCODE(AuthorizationData, buf.data, buf.length,
 267                                    &child.elements, &len, ret);
 268                 if (ret) {
 269                     free_AD_KDCIssued(&child);
 270                     krb5_clear_error_message(context);
 271                     goto out;
 272                 }
 273                 if(buf.length != len)
 274                     krb5_abortx(context, "internal error in ASN.1 encoder");
 275
 276                 ret = krb5_c_verify_checksum(context, sessionkey, 19, &buf,
 277                                              &child.ad_checksum, &valid);
 278                 krb5_data_free(&buf);
 279                 if (ret) {
 280                     free_AD_KDCIssued(&child);
 281                     goto out;
 282                 }
 283                 if (!valid) {
 284                     krb5_clear_error_message(context);
 285                     ret = ENOENT;
 286                     free_AD_KDCIssued(&child);
 287                     goto out;
 288                 }
 289             }
 290             ret = find_type_in_ad(context, type, data, found, failp, sessionkey,
 291                                   &child.elements, level + 1);
 292             free_AD_KDCIssued(&child);
 293             if (ret)
 294                 goto out;
 295             break;
 296         }
 297 #endif
 298         case KRB5_AUTHDATA_AND_OR:
 299             if (!failp)
 300                 break;
 301             ret = ENOENT; /* XXX */
 302             krb5_set_error_message(context, ret,
 303                                    N_("Authorization data contains "
 304                                       "AND-OR element that is unknown to the "
 305                                       "application", ""));
 306             goto out;
 307         default:
 308             if (!failp)
 309                 break;
 310             ret = ENOENT; /* XXX */
 311             krb5_set_error_message(context, ret,
 312                                    N_("Authorization data contains "
 313                                       "unknown type (%d) ", ""),
 314                                    ad->val[i].ad_type);
 315             goto out;
 316         }
 317     }
 318 out:
 319     if (ret) {
 320         if (*found) {
 321             krb5_data_free(data);
 322             *found = 0;
 323         }
 324     }
 325     return ret;
 326 }
 327
 328 /**
 329  * Extract the authorization data type of type from the ticket. Store
 330  * the field in data. This function is to use for kerberos
 331  * applications.
 332  *
 333  * @param context a Kerberos 5 context
 334  * @param ticket Kerberos ticket
 335  * @param type type to fetch
 336  * @param data returned data, free with krb5_data_free()
 337  *
 338  * @ingroup krb5
 339  */
 340
 341 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 342 krb5_ticket_get_authorization_data_type(krb5_context context,
 343                                         krb5_ticket *ticket,
 344                                         int type,
 345                                         krb5_data *data)
 346 {
 347     AuthorizationData *ad;
 348     krb5_error_code ret;
 349     krb5_boolean found = FALSE;
 350
 351     krb5_data_zero(data);
 352
 353     ad = ticket->ticket.authorization_data;
 354     if (ticket->ticket.authorization_data == NULL) {
 355         krb5_set_error_message(context, ENOENT,
 356                                N_("Ticket have not authorization data", ""));
 357         return ENOENT; /* XXX */
 358     }
 359
 360     ret = find_type_in_ad(context, type, data, &found, TRUE,
 361                           &ticket->ticket.key, ad, 0);
 362     if (ret)
 363         return ret;
 364     if (!found) {
 365         krb5_set_error_message(context, ENOENT,
 366                                N_("Ticket have not "
 367                                   "authorization data of type %d", ""),
 368                                type);
 369         return ENOENT; /* XXX */
 370     }
 371     return 0;
 372 }
 373
 374 static krb5_error_code
 375 check_server_referral(krb5_context context,
 376                       krb5_kdc_rep *rep,
 377                       unsigned flags,
 378                       krb5_const_principal requested,
 379                       krb5_const_principal returned,
 380                       krb5_keyblock * key)
 381 {
 382     krb5_error_code ret;
 383     PA_ServerReferralData ref;
 384     krb5_crypto session;
 385     EncryptedData ed;
 386     size_t len;
 387     krb5_data data;
 388     PA_DATA *pa;
 389     int i = 0, cmp;
 390
 391     if (rep->kdc_rep.padata == NULL)
 392         goto noreferral;
 393
 394     pa = krb5_find_padata(rep->kdc_rep.padata->val,
 395                           rep->kdc_rep.padata->len,
 396                           KRB5_PADATA_SERVER_REFERRAL, &i);
 397     if (pa == NULL)
 398         goto noreferral;
 399
 400     memset(&ed, 0, sizeof(ed));
 401     memset(&ref, 0, sizeof(ref));
 402
 403     ret = decode_EncryptedData(pa->padata_value.data,
 404                                pa->padata_value.length,
 405                                &ed, &len);
 406     if (ret)
 407         return ret;
 408     if (len != pa->padata_value.length) {
 409         free_EncryptedData(&ed);
 410         krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 411                                N_("Referral EncryptedData wrong for realm %s",
 412                                   "realm"), requested->realm);
 413         return KRB5KRB_AP_ERR_MODIFIED;
 414     }
 415
 416     ret = krb5_crypto_init(context, key, 0, &session);
 417     if (ret) {
 418         free_EncryptedData(&ed);
 419         return ret;
 420     }
 421
 422     ret = krb5_decrypt_EncryptedData(context, session,
 423                                      KRB5_KU_PA_SERVER_REFERRAL,
 424                                      &ed, &data);
 425     free_EncryptedData(&ed);
 426     krb5_crypto_destroy(context, session);
 427     if (ret)
 428         return ret;
 429
 430     ret = decode_PA_ServerReferralData(data.data, data.length, &ref, &len);
 431     if (ret) {
 432         krb5_data_free(&data);
 433         return ret;
 434     }
 435     krb5_data_free(&data);
 436
 437     if (strcmp(requested->realm, returned->realm) != 0) {
 438         free_PA_ServerReferralData(&ref);
 439         krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 440                                N_("server ref realm mismatch, "
 441                                   "requested realm %s got back %s", ""),
 442                                requested->realm, returned->realm);
 443         return KRB5KRB_AP_ERR_MODIFIED;
 444     }
 445
 446     if (krb5_principal_is_krbtgt(context, returned)) {
 447         const char *realm = returned->name.name_string.val[1];
 448
 449         if (ref.referred_realm == NULL
 450             || strcmp(*ref.referred_realm, realm) != 0)
 451         {
 452             free_PA_ServerReferralData(&ref);
 453             krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 454                                    N_("tgt returned with wrong ref", ""));
 455             return KRB5KRB_AP_ERR_MODIFIED;
 456         }
 457     } else if (krb5_principal_compare(context, returned, requested) == 0) {
 458         free_PA_ServerReferralData(&ref);
 459         krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 460                                N_("req princ no same as returned", ""));
 461         return KRB5KRB_AP_ERR_MODIFIED;
 462     }
 463
 464     if (ref.requested_principal_name) {
 465         cmp = _krb5_principal_compare_PrincipalName(context,
 466                                                     requested,
 467                                                     ref.requested_principal_name);
 468         if (!cmp) {
 469             free_PA_ServerReferralData(&ref);
 470             krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 471                                    N_("referred principal not same "
 472                                       "as requested", ""));
 473             return KRB5KRB_AP_ERR_MODIFIED;
 474         }
 475     } else if (flags & EXTRACT_TICKET_AS_REQ) {
 476         free_PA_ServerReferralData(&ref);
 477         krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 478                                N_("Requested principal missing on AS-REQ", ""));
 479         return KRB5KRB_AP_ERR_MODIFIED;
 480     }
 481
 482     free_PA_ServerReferralData(&ref);
 483
 484     return ret;
 485 noreferral:
 486     /*
 487      * Expect excact match or that we got a krbtgt
 488      */
 489     if (krb5_principal_compare(context, requested, returned) != TRUE &&
 490         (krb5_realm_compare(context, requested, returned) != TRUE &&
 491          krb5_principal_is_krbtgt(context, returned) != TRUE))
 492     {
 493         krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 494                                N_("Not same server principal returned "
 495                                   "as requested", ""));
 496         return KRB5KRB_AP_ERR_MODIFIED;
 497     }
 498     return 0;
 499 }
 500
 501
 502 /*
 503  * Verify referral data
 504  */
 505
 506
 507 static krb5_error_code
 508 check_client_referral(krb5_context context,
 509                       krb5_kdc_rep *rep,
 510                       krb5_const_principal requested,
 511                       krb5_const_principal mapped,
 512                       krb5_keyblock const * key)
 513 {
 514     krb5_error_code ret;
 515     PA_ClientCanonicalized canon;
 516     krb5_crypto crypto;
 517     krb5_data data;
 518     PA_DATA *pa;
 519     size_t len;
 520     int i = 0;
 521
 522     if (rep->kdc_rep.padata == NULL)
 523         goto noreferral;
 524
 525     pa = krb5_find_padata(rep->kdc_rep.padata->val,
 526                           rep->kdc_rep.padata->len,
 527                           KRB5_PADATA_CLIENT_CANONICALIZED, &i);
 528     if (pa == NULL)
 529         goto noreferral;
 530
 531     ret = decode_PA_ClientCanonicalized(pa->padata_value.data,
 532                                         pa->padata_value.length,
 533                                         &canon, &len);
 534     if (ret) {
 535         krb5_set_error_message(context, ret,
 536                                N_("Failed to decode ClientCanonicalized "
 537                                   "from realm %s", ""), requested->realm);
 538         return ret;
 539     }
 540
 541     ASN1_MALLOC_ENCODE(PA_ClientCanonicalizedNames, data.data, data.length,
 542                        &canon.names, &len, ret);
 543     if (ret) {
 544         free_PA_ClientCanonicalized(&canon);
 545         return ret;
 546     }
 547     if (data.length != len)
 548         krb5_abortx(context, "internal asn.1 error");
 549
 550     ret = krb5_crypto_init(context, key, 0, &crypto);
 551     if (ret) {
 552         free(data.data);
 553         free_PA_ClientCanonicalized(&canon);
 554         return ret;
 555     }
 556
 557     ret = krb5_verify_checksum(context, crypto, KRB5_KU_CANONICALIZED_NAMES,
 558                                data.data, data.length,
 559                                &canon.canon_checksum);
 560     krb5_crypto_destroy(context, crypto);
 561     free(data.data);
 562     if (ret) {
 563         krb5_set_error_message(context, ret,
 564                                N_("Failed to verify client canonicalized "
 565                                   "data from realm %s", ""),
 566                                requested->realm);
 567         free_PA_ClientCanonicalized(&canon);
 568         return ret;
 569     }
 570
 571     if (!_krb5_principal_compare_PrincipalName(context,
 572                                                requested,
 573                                                &canon.names.requested_name))
 574     {
 575         free_PA_ClientCanonicalized(&canon);
 576         krb5_set_error_message(context, KRB5_PRINC_NOMATCH,
 577                                N_("Requested name doesn't match"
 578                                   " in client referral", ""));
 579         return KRB5_PRINC_NOMATCH;
 580     }
 581     if (!_krb5_principal_compare_PrincipalName(context,
 582                                                mapped,
 583                                                &canon.names.mapped_name))
 584     {
 585         free_PA_ClientCanonicalized(&canon);
 586         krb5_set_error_message(context, KRB5_PRINC_NOMATCH,
 587                                N_("Mapped name doesn't match"
 588                                   " in client referral", ""));
 589         return KRB5_PRINC_NOMATCH;
 590     }
 591
 592     return 0;
 593
 594 noreferral:
 595     if (krb5_principal_compare(context, requested, mapped) == FALSE) {
 596         krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 597                                N_("Not same client principal returned "
 598                                   "as requested", ""));
 599         return KRB5KRB_AP_ERR_MODIFIED;
 600     }
 601     return 0;
 602 }
 603
 604
 605 static krb5_error_code
 606 decrypt_tkt (krb5_context context,
 607              krb5_keyblock *key,
 608              krb5_key_usage usage,
 609              krb5_const_pointer decrypt_arg,
 610              krb5_kdc_rep *dec_rep)
 611 {
 612     krb5_error_code ret;
 613     krb5_data data;
 614     size_t size;
 615     krb5_crypto crypto;
 616
 617     ret = krb5_crypto_init(context, key, 0, &crypto);
 618     if (ret)
 619         return ret;
 620
 621     ret = krb5_decrypt_EncryptedData (context,
 622                                       crypto,
 623                                       usage,
 624                                       &dec_rep->kdc_rep.enc_part,
 625                                       &data);
 626     krb5_crypto_destroy(context, crypto);
 627
 628     if (ret)
 629         return ret;
 630
 631     ret = decode_EncASRepPart(data.data,
 632                               data.length,
 633                               &dec_rep->enc_part,
 634                               &size);
 635     if (ret)
 636         ret = decode_EncTGSRepPart(data.data,
 637                                    data.length,
 638                                    &dec_rep->enc_part,
 639                                    &size);
 640     krb5_data_free (&data);
 641     if (ret) {
 642         krb5_set_error_message(context, ret,
 643                                N_("Failed to decode encpart in ticket", ""));
 644         return ret;
 645     }
 646     return 0;
 647 }
 648
 649 int
 650 _krb5_extract_ticket(krb5_context context,
 651                      krb5_kdc_rep *rep,
 652                      krb5_creds *creds,
 653                      krb5_keyblock *key,
 654                      krb5_const_pointer keyseed,
 655                      krb5_key_usage key_usage,
 656                      krb5_addresses *addrs,
 657                      unsigned nonce,
 658                      unsigned flags,
 659                      krb5_decrypt_proc decrypt_proc,
 660                      krb5_const_pointer decryptarg)
 661 {
 662     krb5_error_code ret;
 663     krb5_principal tmp_principal;
 664     size_t len;
 665     time_t tmp_time;
 666     krb5_timestamp sec_now;
 667
 668     /* decrypt */
 669
 670     if (decrypt_proc == NULL)
 671         decrypt_proc = decrypt_tkt;
 672
 673     ret = (*decrypt_proc)(context, key, key_usage, decryptarg, rep);
 674     if (ret)
 675         goto out;
 676
 677     /* save session key */
 678
 679     creds->session.keyvalue.length = 0;
 680     creds->session.keyvalue.data   = NULL;
 681     creds->session.keytype = rep->enc_part.key.keytype;
 682     ret = krb5_data_copy (&creds->session.keyvalue,
 683                           rep->enc_part.key.keyvalue.data,
 684                           rep->enc_part.key.keyvalue.length);
 685     if (ret) {
 686         krb5_clear_error_message(context);
 687         goto out;
 688     }
 689
 690     /*
 691      * HACK:
 692      * this is really a ugly hack, to support using the Netbios Domain Name
 693      * as realm against windows KDC's, they always return the full realm
 694      * based on the DNS Name.
 695      */
 696     flags |= EXTRACT_TICKET_ALLOW_SERVER_MISMATCH;
 697     flags |= EXTRACT_TICKET_ALLOW_CNAME_MISMATCH;
 698
 699     /* compare client and save */
 700     ret = _krb5_principalname2krb5_principal (context,
 701                                               &tmp_principal,
 702                                               rep->kdc_rep.cname,
 703                                               rep->kdc_rep.crealm);
 704     if (ret)
 705         goto out;
 706
 707     /* check client referral and save principal */
 708     /* anonymous here ? */
 709     if((flags & EXTRACT_TICKET_ALLOW_CNAME_MISMATCH) == 0) {
 710         ret = check_client_referral(context, rep,
 711                                     creds->client,
 712                                     tmp_principal,
 713                                     &creds->session);
 714         if (ret) {
 715             krb5_free_principal (context, tmp_principal);
 716             goto out;
 717         }
 718     }
 719     krb5_free_principal (context, creds->client);
 720     creds->client = tmp_principal;
 721
 722     /* check server referral and save principal */
 723     ret = _krb5_principalname2krb5_principal (context,
 724                                               &tmp_principal,
 725                                               rep->kdc_rep.ticket.sname,
 726                                               rep->kdc_rep.ticket.realm);
 727     if (ret)
 728         goto out;
 729     if((flags & EXTRACT_TICKET_ALLOW_SERVER_MISMATCH) == 0){
 730         ret = check_server_referral(context,
 731                                     rep,
 732                                     flags,
 733                                     creds->server,
 734                                     tmp_principal,
 735                                     &creds->session);
 736         if (ret) {
 737             krb5_free_principal (context, tmp_principal);
 738             goto out;
 739         }
 740     }
 741     krb5_free_principal(context, creds->server);
 742     creds->server = tmp_principal;
 743
 744     /* verify names */
 745     if(flags & EXTRACT_TICKET_MATCH_REALM){
 746         const char *srealm = krb5_principal_get_realm(context, creds->server);
 747         const char *crealm = krb5_principal_get_realm(context, creds->client);
 748
 749         if (strcmp(rep->enc_part.srealm, srealm) != 0 ||
 750             strcmp(rep->enc_part.srealm, crealm) != 0)
 751         {
 752             ret = KRB5KRB_AP_ERR_MODIFIED;
 753             krb5_clear_error_message(context);
 754             goto out;
 755         }
 756     }
 757
 758     /* compare nonces */
 759
 760     if (nonce != rep->enc_part.nonce) {
 761         ret = KRB5KRB_AP_ERR_MODIFIED;
 762         krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
 763         goto out;
 764     }
 765
 766     /* set kdc-offset */
 767
 768     krb5_timeofday (context, &sec_now);
 769     if (rep->enc_part.flags.initial
 770         && (flags & EXTRACT_TICKET_TIMESYNC)
 771         && context->kdc_sec_offset == 0
 772         && krb5_config_get_bool (context, NULL,
 773                                  "libdefaults",
 774                                  "kdc_timesync",
 775                                  NULL)) {
 776         context->kdc_sec_offset = rep->enc_part.authtime - sec_now;
 777         krb5_timeofday (context, &sec_now);
 778     }
 779
 780     /* check all times */
 781
 782     if (rep->enc_part.starttime) {
 783         tmp_time = *rep->enc_part.starttime;
 784     } else
 785         tmp_time = rep->enc_part.authtime;
 786
 787     if (creds->times.starttime == 0
 788         && abs(tmp_time - sec_now) > context->max_skew) {
 789         ret = KRB5KRB_AP_ERR_SKEW;
 790         krb5_set_error_message (context, ret,
 791                                 N_("time skew (%d) larger than max (%d)", ""),
 792                                abs(tmp_time - sec_now),
 793                                (int)context->max_skew);
 794         goto out;
 795     }
 796
 797     if (creds->times.starttime != 0
 798         && tmp_time != creds->times.starttime) {
 799         krb5_clear_error_message (context);
 800         ret = KRB5KRB_AP_ERR_MODIFIED;
 801         goto out;
 802     }
 803
 804     creds->times.starttime = tmp_time;
 805
 806     if (rep->enc_part.renew_till) {
 807         tmp_time = *rep->enc_part.renew_till;
 808     } else
 809         tmp_time = 0;
 810
 811     if (creds->times.renew_till != 0
 812         && tmp_time > creds->times.renew_till) {
 813         krb5_clear_error_message (context);
 814         ret = KRB5KRB_AP_ERR_MODIFIED;
 815         goto out;
 816     }
 817
 818     creds->times.renew_till = tmp_time;
 819
 820     creds->times.authtime = rep->enc_part.authtime;
 821
 822     if (creds->times.endtime != 0
 823         && rep->enc_part.endtime > creds->times.endtime) {
 824         krb5_clear_error_message (context);
 825         ret = KRB5KRB_AP_ERR_MODIFIED;
 826         goto out;
 827     }
 828
 829     creds->times.endtime  = rep->enc_part.endtime;
 830
 831     if(rep->enc_part.caddr)
 832         krb5_copy_addresses (context, rep->enc_part.caddr, &creds->addresses);
 833     else if(addrs)
 834         krb5_copy_addresses (context, addrs, &creds->addresses);
 835     else {
 836         creds->addresses.len = 0;
 837         creds->addresses.val = NULL;
 838     }
 839     creds->flags.b = rep->enc_part.flags;
 840
 841     creds->authdata.len = 0;
 842     creds->authdata.val = NULL;
 843
 844     /* extract ticket */
 845     ASN1_MALLOC_ENCODE(Ticket, creds->ticket.data, creds->ticket.length,
 846                        &rep->kdc_rep.ticket, &len, ret);
 847     if(ret)
 848         goto out;
 849     if (creds->ticket.length != len)
 850         krb5_abortx(context, "internal error in ASN.1 encoder");
 851     creds->second_ticket.length = 0;
 852     creds->second_ticket.data   = NULL;
 853
 854
 855 out:
 856     memset (rep->enc_part.key.keyvalue.data, 0,
 857             rep->enc_part.key.keyvalue.length);
 858     return ret;
 859 }