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  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "krb5_locl.h"
  35
  36 krb5_error_code KRB5_LIB_FUNCTION
  37 krb5_free_ticket(krb5_context context,
  38                  krb5_ticket *ticket)
  39 {
  40     free_EncTicketPart(&ticket->ticket);
  41     krb5_free_principal(context, ticket->client);
  42     krb5_free_principal(context, ticket->server);
  43     free(ticket);
  44     return 0;
  45 }
  46
  47 krb5_error_code KRB5_LIB_FUNCTION
  48 krb5_copy_ticket(krb5_context context,
  49                  const krb5_ticket *from,
  50                  krb5_ticket **to)
  51 {
  52     krb5_error_code ret;
  53     krb5_ticket *tmp;
  54
  55     *to = NULL;
  56     tmp = malloc(sizeof(*tmp));
  57     if(tmp == NULL) {
  58         krb5_set_error_message(context, ENOMEM,
  59                                N_("malloc: out of memory", ""));
  60         return ENOMEM;
  61     }
  62     if((ret = copy_EncTicketPart(&from->ticket, &tmp->ticket))){
  63         free(tmp);
  64         return ret;
  65     }
  66     ret = krb5_copy_principal(context, from->client, &tmp->client);
  67     if(ret){
  68         free_EncTicketPart(&tmp->ticket);
  69         free(tmp);
  70         return ret;
  71     }
  72     ret = krb5_copy_principal(context, from->server, &tmp->server);
  73     if(ret){
  74         krb5_free_principal(context, tmp->client);
  75         free_EncTicketPart(&tmp->ticket);
  76         free(tmp);
  77         return ret;
  78     }
  79     *to = tmp;
  80     return 0;
  81 }
  82
  83 krb5_error_code KRB5_LIB_FUNCTION
  84 krb5_ticket_get_client(krb5_context context,
  85                        const krb5_ticket *ticket,
  86                        krb5_principal *client)
  87 {
  88     return krb5_copy_principal(context, ticket->client, client);
  89 }
  90
  91 krb5_error_code KRB5_LIB_FUNCTION
  92 krb5_ticket_get_server(krb5_context context,
  93                        const krb5_ticket *ticket,
  94                        krb5_principal *server)
  95 {
  96     return krb5_copy_principal(context, ticket->server, server);
  97 }
  98
  99 time_t KRB5_LIB_FUNCTION
 100 krb5_ticket_get_endtime(krb5_context context,
 101                         const krb5_ticket *ticket)
 102 {
 103     return ticket->ticket.endtime;
 104 }
 105
 106 /**
 107  * Get the flags from the Kerberos ticket
 108  *
 109  * @param context Kerberos context
 110  * @param ticket Kerberos ticket
 111  *
 112  * @return ticket flags
 113  *
 114  * @ingroup krb5_ticket
 115  */
 116 unsigned long
 117 krb5_ticket_get_flags(krb5_context context,
 118                       const krb5_ticket *ticket)
 119 {
 120     return TicketFlags2int(ticket->ticket.flags);
 121 }
 122
 123 static int
 124 find_type_in_ad(krb5_context context,
 125                 int type,
 126                 krb5_data *data,
 127                 krb5_boolean *found,
 128                 krb5_boolean failp,
 129                 krb5_keyblock *sessionkey,
 130                 const AuthorizationData *ad,
 131                 int level)
 132 {
 133     krb5_error_code ret = 0;
 134     int i;
 135
 136     if (level > 9) {
 137         ret = ENOENT; /* XXX */
 138         krb5_set_error_message(context, ret,
 139                                N_("Authorization data nested deeper "
 140                                   "then %d levels, stop searching", ""),
 141                                level);
 142         goto out;
 143     }
 144
 145     /*
 146      * Only copy out the element the first time we get to it, we need
 147      * to run over the whole authorization data fields to check if
 148      * there are any container clases we need to care about.
 149      */
 150     for (i = 0; i < ad->len; i++) {
 151         if (!*found && ad->val[i].ad_type == type) {
 152             ret = der_copy_octet_string(&ad->val[i].ad_data, data);
 153             if (ret) {
 154                 krb5_set_error_message(context, ret,
 155                                        N_("malloc: out of memory", ""));
 156                 goto out;
 157             }
 158             *found = TRUE;
 159             continue;
 160         }
 161         switch (ad->val[i].ad_type) {
 162         case KRB5_AUTHDATA_IF_RELEVANT: {
 163             AuthorizationData child;
 164             ret = decode_AuthorizationData(ad->val[i].ad_data.data,
 165                                            ad->val[i].ad_data.length,
 166                                            &child,
 167                                            NULL);
 168             if (ret) {
 169                 krb5_set_error_message(context, ret,
 170                                        N_("Failed to decode "
 171                                           "IF_RELEVANT with %d", ""),
 172                                        (int)ret);
 173                 goto out;
 174             }
 175             ret = find_type_in_ad(context, type, data, found, FALSE,
 176                                   sessionkey, &child, level + 1);
 177             free_AuthorizationData(&child);
 178             if (ret)
 179                 goto out;
 180             break;
 181         }
 182 #if 0 /* XXX test */
 183         case KRB5_AUTHDATA_KDC_ISSUED: {
 184             AD_KDCIssued child;
 185
 186             ret = decode_AD_KDCIssued(ad->val[i].ad_data.data,
 187                                       ad->val[i].ad_data.length,
 188                                       &child,
 189                                       NULL);
 190             if (ret) {
 191                 krb5_set_error_message(context, ret,
 192                                        N_("Failed to decode "
 193                                           "AD_KDCIssued with %d", ""),
 194                                        ret);
 195                 goto out;
 196             }
 197             if (failp) {
 198                 krb5_boolean valid;
 199                 krb5_data buf;
 200                 size_t len;
 201
 202                 ASN1_MALLOC_ENCODE(AuthorizationData, buf.data, buf.length,
 203                                    &child.elements, &len, ret);
 204                 if (ret) {
 205                     free_AD_KDCIssued(&child);
 206                     krb5_clear_error_message(context);
 207                     goto out;
 208                 }
 209                 if(buf.length != len)
 210                     krb5_abortx(context, "internal error in ASN.1 encoder");
 211
 212                 ret = krb5_c_verify_checksum(context, sessionkey, 19, &buf,
 213                                              &child.ad_checksum, &valid);
 214                 krb5_data_free(&buf);
 215                 if (ret) {
 216                     free_AD_KDCIssued(&child);
 217                     goto out;
 218                 }
 219                 if (!valid) {
 220                     krb5_clear_error_message(context);
 221                     ret = ENOENT;
 222                     free_AD_KDCIssued(&child);
 223                     goto out;
 224                 }
 225             }
 226             ret = find_type_in_ad(context, type, data, found, failp, sessionkey,
 227                                   &child.elements, level + 1);
 228             free_AD_KDCIssued(&child);
 229             if (ret)
 230                 goto out;
 231             break;
 232         }
 233 #endif
 234         case KRB5_AUTHDATA_AND_OR:
 235             if (!failp)
 236                 break;
 237             ret = ENOENT; /* XXX */
 238             krb5_set_error_message(context, ret,
 239                                    N_("Authorization data contains "
 240                                       "AND-OR element that is unknown to the "
 241                                       "application", ""));
 242             goto out;
 243         default:
 244             if (!failp)
 245                 break;
 246             ret = ENOENT; /* XXX */
 247             krb5_set_error_message(context, ret,
 248                                    N_("Authorization data contains "
 249                                       "unknown type (%d) ", ""),
 250                                    ad->val[i].ad_type);
 251             goto out;
 252         }
 253     }
 254 out:
 255     if (ret) {
 256         if (*found) {
 257             krb5_data_free(data);
 258             *found = 0;
 259         }
 260     }
 261     return ret;
 262 }
 263
 264 /*
 265  * Extract the authorization data type of `type' from the
 266  * 'ticket'. Store the field in `data'. This function is to use for
 267  * kerberos applications.
 268  */
 269
 270 krb5_error_code KRB5_LIB_FUNCTION
 271 krb5_ticket_get_authorization_data_type(krb5_context context,
 272                                         krb5_ticket *ticket,
 273                                         int type,
 274                                         krb5_data *data)
 275 {
 276     AuthorizationData *ad;
 277     krb5_error_code ret;
 278     krb5_boolean found = FALSE;
 279
 280     krb5_data_zero(data);
 281
 282     ad = ticket->ticket.authorization_data;
 283     if (ticket->ticket.authorization_data == NULL) {
 284         krb5_set_error_message(context, ENOENT,
 285                                N_("Ticket have not authorization data", ""));
 286         return ENOENT; /* XXX */
 287     }
 288
 289     ret = find_type_in_ad(context, type, data, &found, TRUE,
 290                           &ticket->ticket.key, ad, 0);
 291     if (ret)
 292         return ret;
 293     if (!found) {
 294         krb5_set_error_message(context, ENOENT,
 295                                N_("Ticket have not "
 296                                   "authorization data of type %d", ""),
 297                                type);
 298         return ENOENT; /* XXX */
 299     }
 300     return 0;
 301 }
 302
 303 static krb5_error_code
 304 check_server_referral(krb5_context context,
 305                       krb5_kdc_rep *rep,
 306                       unsigned flags,
 307                       krb5_const_principal requested,
 308                       krb5_const_principal returned,
 309                       krb5_keyblock * key)
 310 {
 311     krb5_error_code ret;
 312     PA_ServerReferralData ref;
 313     krb5_crypto session;
 314     EncryptedData ed;
 315     size_t len;
 316     krb5_data data;
 317     PA_DATA *pa;
 318     int i = 0, cmp;
 319
 320     if (rep->kdc_rep.padata == NULL)
 321         goto noreferral;
 322
 323     pa = krb5_find_padata(rep->kdc_rep.padata->val,
 324                           rep->kdc_rep.padata->len,
 325                           KRB5_PADATA_SERVER_REFERRAL, &i);
 326     if (pa == NULL)
 327         goto noreferral;
 328
 329     memset(&ed, 0, sizeof(ed));
 330     memset(&ref, 0, sizeof(ref));
 331
 332     ret = decode_EncryptedData(pa->padata_value.data,
 333                                pa->padata_value.length,
 334                                &ed, &len);
 335     if (ret)
 336         return ret;
 337     if (len != pa->padata_value.length) {
 338         free_EncryptedData(&ed);
 339         krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 340                                N_("Referral EncryptedData wrong for realm %s",
 341                                   "realm"), requested->realm);
 342         return KRB5KRB_AP_ERR_MODIFIED;
 343     }
 344
 345     ret = krb5_crypto_init(context, key, 0, &session);
 346     if (ret) {
 347         free_EncryptedData(&ed);
 348         return ret;
 349     }
 350
 351     ret = krb5_decrypt_EncryptedData(context, session,
 352                                      KRB5_KU_PA_SERVER_REFERRAL,
 353                                      &ed, &data);
 354     free_EncryptedData(&ed);
 355     krb5_crypto_destroy(context, session);
 356     if (ret)
 357         return ret;
 358
 359     ret = decode_PA_ServerReferralData(data.data, data.length, &ref, &len);
 360     if (ret) {
 361         krb5_data_free(&data);
 362         return ret;
 363     }
 364     krb5_data_free(&data);
 365
 366     if (strcmp(requested->realm, returned->realm) != 0) {
 367         free_PA_ServerReferralData(&ref);
 368         krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 369                                N_("server ref realm mismatch, "
 370                                   "requested realm %s got back %s", ""),
 371                                requested->realm, returned->realm);
 372         return KRB5KRB_AP_ERR_MODIFIED;
 373     }
 374
 375     if (returned->name.name_string.len == 2 &&
 376         strcmp(returned->name.name_string.val[0], KRB5_TGS_NAME) == 0)
 377     {
 378         const char *realm = returned->name.name_string.val[1];
 379
 380         if (ref.referred_realm == NULL
 381             || strcmp(*ref.referred_realm, realm) != 0)
 382         {
 383             free_PA_ServerReferralData(&ref);
 384             krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 385                                    N_("tgt returned with wrong ref", ""));
 386             return KRB5KRB_AP_ERR_MODIFIED;
 387         }
 388     } else if (krb5_principal_compare(context, returned, requested) == 0) {
 389         free_PA_ServerReferralData(&ref);
 390         krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 391                                N_("req princ no same as returned", ""));
 392         return KRB5KRB_AP_ERR_MODIFIED;
 393     }
 394
 395     if (ref.requested_principal_name) {
 396         cmp = _krb5_principal_compare_PrincipalName(context,
 397                                                     requested,
 398                                                     ref.requested_principal_name);
 399         if (!cmp) {
 400             free_PA_ServerReferralData(&ref);
 401             krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 402                                    N_("referred principal not same "
 403                                       "as requested", ""));
 404             return KRB5KRB_AP_ERR_MODIFIED;
 405         }
 406     } else if (flags & EXTRACT_TICKET_AS_REQ) {
 407         free_PA_ServerReferralData(&ref);
 408         krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 409                                N_("Requested principal missing on AS-REQ", ""));
 410         return KRB5KRB_AP_ERR_MODIFIED;
 411     }
 412
 413     free_PA_ServerReferralData(&ref);
 414
 415     return ret;
 416 noreferral:
 417     if (krb5_principal_compare(context, requested, returned) == FALSE) {
 418         krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 419                                N_("Not same server principal returned "
 420                                   "as requested", ""));
 421         return KRB5KRB_AP_ERR_MODIFIED;
 422     }
 423     return 0;
 424 }
 425
 426
 427 /*
 428  * Verify referral data
 429  */
 430
 431
 432 static krb5_error_code
 433 check_client_referral(krb5_context context,
 434                       krb5_kdc_rep *rep,
 435                       krb5_const_principal requested,
 436                       krb5_const_principal mapped,
 437                       krb5_keyblock const * key)
 438 {
 439     krb5_error_code ret;
 440     PA_ClientCanonicalized canon;
 441     krb5_crypto crypto;
 442     krb5_data data;
 443     PA_DATA *pa;
 444     size_t len;
 445     int i = 0;
 446
 447     if (rep->kdc_rep.padata == NULL)
 448         goto noreferral;
 449
 450     pa = krb5_find_padata(rep->kdc_rep.padata->val,
 451                           rep->kdc_rep.padata->len,
 452                           KRB5_PADATA_CLIENT_CANONICALIZED, &i);
 453     if (pa == NULL)
 454         goto noreferral;
 455
 456     ret = decode_PA_ClientCanonicalized(pa->padata_value.data,
 457                                         pa->padata_value.length,
 458                                         &canon, &len);
 459     if (ret) {
 460         krb5_set_error_message(context, ret,
 461                                N_("Failed to decode ClientCanonicalized "
 462                                   "from realm %s", ""), requested->realm);
 463         return ret;
 464     }
 465
 466     ASN1_MALLOC_ENCODE(PA_ClientCanonicalizedNames, data.data, data.length,
 467                        &canon.names, &len, ret);
 468     if (ret) {
 469         free_PA_ClientCanonicalized(&canon);
 470         return ret;
 471     }
 472     if (data.length != len)
 473         krb5_abortx(context, "internal asn.1 error");
 474
 475     ret = krb5_crypto_init(context, key, 0, &crypto);
 476     if (ret) {
 477         free(data.data);
 478         free_PA_ClientCanonicalized(&canon);
 479         return ret;
 480     }
 481
 482     ret = krb5_verify_checksum(context, crypto, KRB5_KU_CANONICALIZED_NAMES,
 483                                data.data, data.length,
 484                                &canon.canon_checksum);
 485     krb5_crypto_destroy(context, crypto);
 486     free(data.data);
 487     if (ret) {
 488         krb5_set_error_message(context, ret,
 489                                N_("Failed to verify client canonicalized "
 490                                   "data from realm %s", ""),
 491                                requested->realm);
 492         free_PA_ClientCanonicalized(&canon);
 493         return ret;
 494     }
 495
 496     if (!_krb5_principal_compare_PrincipalName(context,
 497                                                requested,
 498                                                &canon.names.requested_name))
 499     {
 500         free_PA_ClientCanonicalized(&canon);
 501         krb5_set_error_message(context, KRB5_PRINC_NOMATCH,
 502                                N_("Requested name doesn't match"
 503                                   " in client referral", ""));
 504         return KRB5_PRINC_NOMATCH;
 505     }
 506     if (!_krb5_principal_compare_PrincipalName(context,
 507                                                mapped,
 508                                                &canon.names.mapped_name))
 509     {
 510         free_PA_ClientCanonicalized(&canon);
 511         krb5_set_error_message(context, KRB5_PRINC_NOMATCH,
 512                                N_("Mapped name doesn't match"
 513                                   " in client referral", ""));
 514         return KRB5_PRINC_NOMATCH;
 515     }
 516
 517     return 0;
 518
 519 noreferral:
 520     if (krb5_principal_compare(context, requested, mapped) == FALSE) {
 521         krb5_set_error_message(context, KRB5KRB_AP_ERR_MODIFIED,
 522                                N_("Not same client principal returned "
 523                                   "as requested", ""));
 524         return KRB5KRB_AP_ERR_MODIFIED;
 525     }
 526     return 0;
 527 }
 528
 529
 530 static krb5_error_code
 531 decrypt_tkt (krb5_context context,
 532              krb5_keyblock *key,
 533              krb5_key_usage usage,
 534              krb5_const_pointer decrypt_arg,
 535              krb5_kdc_rep *dec_rep)
 536 {
 537     krb5_error_code ret;
 538     krb5_data data;
 539     size_t size;
 540     krb5_crypto crypto;
 541
 542     ret = krb5_crypto_init(context, key, 0, &crypto);
 543     if (ret)
 544         return ret;
 545
 546     ret = krb5_decrypt_EncryptedData (context,
 547                                       crypto,
 548                                       usage,
 549                                       &dec_rep->kdc_rep.enc_part,
 550                                       &data);
 551     krb5_crypto_destroy(context, crypto);
 552
 553     if (ret)
 554         return ret;
 555
 556     ret = decode_EncASRepPart(data.data,
 557                               data.length,
 558                               &dec_rep->enc_part,
 559                               &size);
 560     if (ret)
 561         ret = decode_EncTGSRepPart(data.data,
 562                                    data.length,
 563                                    &dec_rep->enc_part,
 564                                    &size);
 565     krb5_data_free (&data);
 566     if (ret) {
 567         krb5_set_error_message(context, ret,
 568                                N_("Failed to decode encpart in ticket", ""));
 569         return ret;
 570     }
 571     return 0;
 572 }
 573
 574 int
 575 _krb5_extract_ticket(krb5_context context,
 576                      krb5_kdc_rep *rep,
 577                      krb5_creds *creds,
 578                      krb5_keyblock *key,
 579                      krb5_const_pointer keyseed,
 580                      krb5_key_usage key_usage,
 581                      krb5_addresses *addrs,
 582                      unsigned nonce,
 583                      unsigned flags,
 584                      krb5_decrypt_proc decrypt_proc,
 585                      krb5_const_pointer decryptarg)
 586 {
 587     krb5_error_code ret;
 588     krb5_principal tmp_principal;
 589     size_t len;
 590     time_t tmp_time;
 591     krb5_timestamp sec_now;
 592
 593     /* decrypt */
 594
 595     if (decrypt_proc == NULL)
 596         decrypt_proc = decrypt_tkt;
 597
 598     ret = (*decrypt_proc)(context, key, key_usage, decryptarg, rep);
 599     if (ret)
 600         goto out;
 601
 602     /* save session key */
 603
 604     creds->session.keyvalue.length = 0;
 605     creds->session.keyvalue.data   = NULL;
 606     creds->session.keytype = rep->enc_part.key.keytype;
 607     ret = krb5_data_copy (&creds->session.keyvalue,
 608                           rep->enc_part.key.keyvalue.data,
 609                           rep->enc_part.key.keyvalue.length);
 610     if (ret) {
 611         krb5_clear_error_message(context);
 612         goto out;
 613     }
 614
 615     /* compare client and save */
 616     ret = _krb5_principalname2krb5_principal (context,
 617                                               &tmp_principal,
 618                                               rep->kdc_rep.cname,
 619                                               rep->kdc_rep.crealm);
 620     if (ret)
 621         goto out;
 622
 623     /* check client referral and save principal */
 624     /* anonymous here ? */
 625     if((flags & EXTRACT_TICKET_ALLOW_CNAME_MISMATCH) == 0) {
 626         ret = check_client_referral(context, rep,
 627                                     creds->client,
 628                                     tmp_principal,
 629                                     &creds->session);
 630         if (ret) {
 631             krb5_free_principal (context, tmp_principal);
 632             goto out;
 633         }
 634     }
 635     krb5_free_principal (context, creds->client);
 636     creds->client = tmp_principal;
 637
 638     /* check server referral and save principal */
 639     ret = _krb5_principalname2krb5_principal (context,
 640                                               &tmp_principal,
 641                                               rep->kdc_rep.ticket.sname,
 642                                               rep->kdc_rep.ticket.realm);
 643     if (ret)
 644         goto out;
 645     if((flags & EXTRACT_TICKET_ALLOW_SERVER_MISMATCH) == 0){
 646         ret = check_server_referral(context,
 647                                     rep,
 648                                     flags,
 649                                     creds->server,
 650                                     tmp_principal,
 651                                     &creds->session);
 652         if (ret) {
 653             krb5_free_principal (context, tmp_principal);
 654             goto out;
 655         }
 656     }
 657     krb5_free_principal(context, creds->server);
 658     creds->server = tmp_principal;
 659
 660     /* verify names */
 661     if(flags & EXTRACT_TICKET_MATCH_REALM){
 662         const char *srealm = krb5_principal_get_realm(context, creds->server);
 663         const char *crealm = krb5_principal_get_realm(context, creds->client);
 664
 665         if (strcmp(rep->enc_part.srealm, srealm) != 0 ||
 666             strcmp(rep->enc_part.srealm, crealm) != 0)
 667         {
 668             ret = KRB5KRB_AP_ERR_MODIFIED;
 669             krb5_clear_error_message(context);
 670             goto out;
 671         }
 672     }
 673
 674     /* compare nonces */
 675
 676     if (nonce != rep->enc_part.nonce) {
 677         ret = KRB5KRB_AP_ERR_MODIFIED;
 678         krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
 679         goto out;
 680     }
 681
 682     /* set kdc-offset */
 683
 684     krb5_timeofday (context, &sec_now);
 685     if (rep->enc_part.flags.initial
 686         && context->kdc_sec_offset == 0
 687         && krb5_config_get_bool (context, NULL,
 688                                  "libdefaults",
 689                                  "kdc_timesync",
 690                                  NULL)) {
 691         context->kdc_sec_offset = rep->enc_part.authtime - sec_now;
 692         krb5_timeofday (context, &sec_now);
 693     }
 694
 695     /* check all times */
 696
 697     if (rep->enc_part.starttime) {
 698         tmp_time = *rep->enc_part.starttime;
 699     } else
 700         tmp_time = rep->enc_part.authtime;
 701
 702     if (creds->times.starttime == 0
 703         && abs(tmp_time - sec_now) > context->max_skew) {
 704         ret = KRB5KRB_AP_ERR_SKEW;
 705         krb5_set_error_message (context, ret,
 706                                 N_("time skew (%d) larger than max (%d)", ""),
 707                                abs(tmp_time - sec_now),
 708                                (int)context->max_skew);
 709         goto out;
 710     }
 711
 712     if (creds->times.starttime != 0
 713         && tmp_time != creds->times.starttime) {
 714         krb5_clear_error_message (context);
 715         ret = KRB5KRB_AP_ERR_MODIFIED;
 716         goto out;
 717     }
 718
 719     creds->times.starttime = tmp_time;
 720
 721     if (rep->enc_part.renew_till) {
 722         tmp_time = *rep->enc_part.renew_till;
 723     } else
 724         tmp_time = 0;
 725
 726     if (creds->times.renew_till != 0
 727         && tmp_time > creds->times.renew_till) {
 728         krb5_clear_error_message (context);
 729         ret = KRB5KRB_AP_ERR_MODIFIED;
 730         goto out;
 731     }
 732
 733     creds->times.renew_till = tmp_time;
 734
 735     creds->times.authtime = rep->enc_part.authtime;
 736
 737     if (creds->times.endtime != 0
 738         && rep->enc_part.endtime > creds->times.endtime) {
 739         krb5_clear_error_message (context);
 740         ret = KRB5KRB_AP_ERR_MODIFIED;
 741         goto out;
 742     }
 743
 744     creds->times.endtime  = rep->enc_part.endtime;
 745
 746     if(rep->enc_part.caddr)
 747         krb5_copy_addresses (context, rep->enc_part.caddr, &creds->addresses);
 748     else if(addrs)
 749         krb5_copy_addresses (context, addrs, &creds->addresses);
 750     else {
 751         creds->addresses.len = 0;
 752         creds->addresses.val = NULL;
 753     }
 754     creds->flags.b = rep->enc_part.flags;
 755
 756     creds->authdata.len = 0;
 757     creds->authdata.val = NULL;
 758
 759     /* extract ticket */
 760     ASN1_MALLOC_ENCODE(Ticket, creds->ticket.data, creds->ticket.length,
 761                        &rep->kdc_rep.ticket, &len, ret);
 762     if(ret)
 763         goto out;
 764     if (creds->ticket.length != len)
 765         krb5_abortx(context, "internal error in ASN.1 encoder");
 766     creds->second_ticket.length = 0;
 767     creds->second_ticket.data   = NULL;
 768
 769
 770 out:
 771     memset (rep->enc_part.key.keyvalue.data, 0,
 772             rep->enc_part.key.keyvalue.length);
 773     return ret;
 774 }