lib/krb5/rd_req.c

   1 /*
   2  * Copyright (c) 1997 - 2007 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 RCSID("$Id$");
  37
  38 static krb5_error_code
  39 decrypt_tkt_enc_part (krb5_context context,
  40                       krb5_keyblock *key,
  41                       EncryptedData *enc_part,
  42                       EncTicketPart *decr_part)
  43 {
  44     krb5_error_code ret;
  45     krb5_data plain;
  46     size_t len;
  47     krb5_crypto crypto;
  48
  49     ret = krb5_crypto_init(context, key, 0, &crypto);
  50     if (ret)
  51         return ret;
  52     ret = krb5_decrypt_EncryptedData (context,
  53                                       crypto,
  54                                       KRB5_KU_TICKET,
  55                                       enc_part,
  56                                       &plain);
  57     krb5_crypto_destroy(context, crypto);
  58     if (ret)
  59         return ret;
  60
  61     ret = krb5_decode_EncTicketPart(context, plain.data, plain.length,
  62                                     decr_part, &len);
  63     krb5_data_free (&plain);
  64     return ret;
  65 }
  66
  67 static krb5_error_code
  68 decrypt_authenticator (krb5_context context,
  69                        EncryptionKey *key,
  70                        EncryptedData *enc_part,
  71                        Authenticator *authenticator,
  72                        krb5_key_usage usage)
  73 {
  74     krb5_error_code ret;
  75     krb5_data plain;
  76     size_t len;
  77     krb5_crypto crypto;
  78
  79     ret = krb5_crypto_init(context, key, 0, &crypto);
  80     if (ret)
  81         return ret;
  82     ret = krb5_decrypt_EncryptedData (context,
  83                                       crypto,
  84                                       usage /* KRB5_KU_AP_REQ_AUTH */,
  85                                       enc_part,
  86                                       &plain);
  87     /* for backwards compatibility, also try the old usage */
  88     if (ret && usage == KRB5_KU_TGS_REQ_AUTH)
  89         ret = krb5_decrypt_EncryptedData (context,
  90                                           crypto,
  91                                           KRB5_KU_AP_REQ_AUTH,
  92                                           enc_part,
  93                                           &plain);
  94     krb5_crypto_destroy(context, crypto);
  95     if (ret)
  96         return ret;
  97
  98     ret = krb5_decode_Authenticator(context, plain.data, plain.length,
  99                                     authenticator, &len);
 100     krb5_data_free (&plain);
 101     return ret;
 102 }
 103
 104 krb5_error_code KRB5_LIB_FUNCTION
 105 krb5_decode_ap_req(krb5_context context,
 106                    const krb5_data *inbuf,
 107                    krb5_ap_req *ap_req)
 108 {
 109     krb5_error_code ret;
 110     size_t len;
 111     ret = decode_AP_REQ(inbuf->data, inbuf->length, ap_req, &len);
 112     if (ret)
 113         return ret;
 114     if (ap_req->pvno != 5){
 115         free_AP_REQ(ap_req);
 116         krb5_clear_error_string (context);
 117         return KRB5KRB_AP_ERR_BADVERSION;
 118     }
 119     if (ap_req->msg_type != krb_ap_req){
 120         free_AP_REQ(ap_req);
 121         krb5_clear_error_string (context);
 122         return KRB5KRB_AP_ERR_MSG_TYPE;
 123     }
 124     if (ap_req->ticket.tkt_vno != 5){
 125         free_AP_REQ(ap_req);
 126         krb5_clear_error_string (context);
 127         return KRB5KRB_AP_ERR_BADVERSION;
 128     }
 129     return 0;
 130 }
 131
 132 static krb5_error_code
 133 check_transited(krb5_context context, Ticket *ticket, EncTicketPart *enc)
 134 {
 135     char **realms;
 136     int num_realms;
 137     krb5_error_code ret;
 138
 139     /*
 140      * Windows 2000 and 2003 uses this inside their TGT so it's normaly
 141      * not seen by others, however, samba4 joined with a Windows AD as
 142      * a Domain Controller gets exposed to this.
 143      */
 144     if(enc->transited.tr_type == 0 && enc->transited.contents.length == 0)
 145         return 0;
 146
 147     if(enc->transited.tr_type != DOMAIN_X500_COMPRESS)
 148         return KRB5KDC_ERR_TRTYPE_NOSUPP;
 149
 150     if(enc->transited.contents.length == 0)
 151         return 0;
 152
 153     ret = krb5_domain_x500_decode(context, enc->transited.contents,
 154                                   &realms, &num_realms,
 155                                   enc->crealm,
 156                                   ticket->realm);
 157     if(ret)
 158         return ret;
 159     ret = krb5_check_transited(context, enc->crealm,
 160                                ticket->realm,
 161                                realms, num_realms, NULL);
 162     free(realms);
 163     return ret;
 164 }
 165
 166 static krb5_error_code
 167 find_etypelist(krb5_context context,
 168                krb5_auth_context auth_context,
 169                EtypeList *etypes)
 170 {
 171     krb5_error_code ret;
 172     krb5_authdata *ad;
 173     krb5_authdata adIfRelevant;
 174     unsigned i;
 175
 176     adIfRelevant.len = 0;
 177
 178     etypes->len = 0;
 179     etypes->val = NULL;
 180
 181     ad = auth_context->authenticator->authorization_data;
 182     if (ad == NULL)
 183         return 0;
 184
 185     for (i = 0; i < ad->len; i++) {
 186         if (ad->val[i].ad_type == KRB5_AUTHDATA_IF_RELEVANT) {
 187             ret = decode_AD_IF_RELEVANT(ad->val[i].ad_data.data,
 188                                         ad->val[i].ad_data.length,
 189                                         &adIfRelevant,
 190                                         NULL);
 191             if (ret)
 192                 return ret;
 193
 194             if (adIfRelevant.len == 1 &&
 195                 adIfRelevant.val[0].ad_type ==
 196                         KRB5_AUTHDATA_GSS_API_ETYPE_NEGOTIATION) {
 197                 break;
 198             }
 199             free_AD_IF_RELEVANT(&adIfRelevant);
 200             adIfRelevant.len = 0;
 201         }
 202     }
 203
 204     if (adIfRelevant.len == 0)
 205         return 0;
 206
 207     ret = decode_EtypeList(adIfRelevant.val[0].ad_data.data,
 208                            adIfRelevant.val[0].ad_data.length,
 209                            etypes,
 210                            NULL);
 211     if (ret)
 212         krb5_clear_error_string(context);
 213
 214     free_AD_IF_RELEVANT(&adIfRelevant);
 215
 216     return ret;
 217 }
 218
 219 krb5_error_code KRB5_LIB_FUNCTION
 220 krb5_decrypt_ticket(krb5_context context,
 221                     Ticket *ticket,
 222                     krb5_keyblock *key,
 223                     EncTicketPart *out,
 224                     krb5_flags flags)
 225 {
 226     EncTicketPart t;
 227     krb5_error_code ret;
 228     ret = decrypt_tkt_enc_part (context, key, &ticket->enc_part, &t);
 229     if (ret)
 230         return ret;
 231
 232     {
 233         krb5_timestamp now;
 234         time_t start = t.authtime;
 235
 236         krb5_timeofday (context, &now);
 237         if(t.starttime)
 238             start = *t.starttime;
 239         if(start - now > context->max_skew
 240            || (t.flags.invalid
 241                && !(flags & KRB5_VERIFY_AP_REQ_IGNORE_INVALID))) {
 242             free_EncTicketPart(&t);
 243             krb5_clear_error_string (context);
 244             return KRB5KRB_AP_ERR_TKT_NYV;
 245         }
 246         if(now - t.endtime > context->max_skew) {
 247             free_EncTicketPart(&t);
 248             krb5_clear_error_string (context);
 249             return KRB5KRB_AP_ERR_TKT_EXPIRED;
 250         }
 251
 252         if(!t.flags.transited_policy_checked) {
 253             ret = check_transited(context, ticket, &t);
 254             if(ret) {
 255                 free_EncTicketPart(&t);
 256                 return ret;
 257             }
 258         }
 259     }
 260
 261     if(out)
 262         *out = t;
 263     else
 264         free_EncTicketPart(&t);
 265     return 0;
 266 }
 267
 268 krb5_error_code KRB5_LIB_FUNCTION
 269 krb5_verify_authenticator_checksum(krb5_context context,
 270                                    krb5_auth_context ac,
 271                                    void *data,
 272                                    size_t len)
 273 {
 274     krb5_error_code ret;
 275     krb5_keyblock *key;
 276     krb5_authenticator authenticator;
 277     krb5_crypto crypto;
 278
 279     ret = krb5_auth_con_getauthenticator (context,
 280                                       ac,
 281                                       &authenticator);
 282     if(ret)
 283         return ret;
 284     if(authenticator->cksum == NULL) {
 285         krb5_free_authenticator(context, &authenticator);
 286         return -17;
 287     }
 288     ret = krb5_auth_con_getkey(context, ac, &key);
 289     if(ret) {
 290         krb5_free_authenticator(context, &authenticator);
 291         return ret;
 292     }
 293     ret = krb5_crypto_init(context, key, 0, &crypto);
 294     if(ret)
 295         goto out;
 296     ret = krb5_verify_checksum (context,
 297                                 crypto,
 298                                 KRB5_KU_AP_REQ_AUTH_CKSUM,
 299                                 data,
 300                                 len,
 301                                 authenticator->cksum);
 302     krb5_crypto_destroy(context, crypto);
 303 out:
 304     krb5_free_authenticator(context, &authenticator);
 305     krb5_free_keyblock(context, key);
 306     return ret;
 307 }
 308
 309
 310 krb5_error_code KRB5_LIB_FUNCTION
 311 krb5_verify_ap_req(krb5_context context,
 312                    krb5_auth_context *auth_context,
 313                    krb5_ap_req *ap_req,
 314                    krb5_const_principal server,
 315                    krb5_keyblock *keyblock,
 316                    krb5_flags flags,
 317                    krb5_flags *ap_req_options,
 318                    krb5_ticket **ticket)
 319 {
 320     return krb5_verify_ap_req2 (context,
 321                                 auth_context,
 322                                 ap_req,
 323                                 server,
 324                                 keyblock,
 325                                 flags,
 326                                 ap_req_options,
 327                                 ticket,
 328                                 KRB5_KU_AP_REQ_AUTH);
 329 }
 330
 331 krb5_error_code KRB5_LIB_FUNCTION
 332 krb5_verify_ap_req2(krb5_context context,
 333                     krb5_auth_context *auth_context,
 334                     krb5_ap_req *ap_req,
 335                     krb5_const_principal server,
 336                     krb5_keyblock *keyblock,
 337                     krb5_flags flags,
 338                     krb5_flags *ap_req_options,
 339                     krb5_ticket **ticket,
 340                     krb5_key_usage usage)
 341 {
 342     krb5_ticket *t;
 343     krb5_auth_context ac;
 344     krb5_error_code ret;
 345     EtypeList etypes;
 346
 347     if (ticket)
 348         *ticket = NULL;
 349
 350     if (auth_context && *auth_context) {
 351         ac = *auth_context;
 352     } else {
 353         ret = krb5_auth_con_init (context, &ac);
 354         if (ret)
 355             return ret;
 356     }
 357
 358     t = calloc(1, sizeof(*t));
 359     if (t == NULL) {
 360         ret = ENOMEM;
 361         krb5_clear_error_string (context);
 362         goto out;
 363     }
 364
 365     if (ap_req->ap_options.use_session_key && ac->keyblock){
 366         ret = krb5_decrypt_ticket(context, &ap_req->ticket,
 367                                   ac->keyblock,
 368                                   &t->ticket,
 369                                   flags);
 370         krb5_free_keyblock(context, ac->keyblock);
 371         ac->keyblock = NULL;
 372     }else
 373         ret = krb5_decrypt_ticket(context, &ap_req->ticket,
 374                                   keyblock,
 375                                   &t->ticket,
 376                                   flags);
 377
 378     if(ret)
 379         goto out;
 380
 381     ret = _krb5_principalname2krb5_principal(context,
 382                                              &t->server,
 383                                              ap_req->ticket.sname,
 384                                              ap_req->ticket.realm);
 385     if (ret) goto out;
 386     ret = _krb5_principalname2krb5_principal(context,
 387                                              &t->client,
 388                                              t->ticket.cname,
 389                                              t->ticket.crealm);
 390     if (ret) goto out;
 391
 392     /* save key */
 393
 394     ret = krb5_copy_keyblock(context, &t->ticket.key, &ac->keyblock);
 395     if (ret) goto out;
 396
 397     ret = decrypt_authenticator (context,
 398                                  &t->ticket.key,
 399                                  &ap_req->authenticator,
 400                                  ac->authenticator,
 401                                  usage);
 402     if (ret)
 403         goto out;
 404
 405     {
 406         krb5_principal p1, p2;
 407         krb5_boolean res;
 408
 409         _krb5_principalname2krb5_principal(context,
 410                                            &p1,
 411                                            ac->authenticator->cname,
 412                                            ac->authenticator->crealm);
 413         _krb5_principalname2krb5_principal(context,
 414                                            &p2,
 415                                            t->ticket.cname,
 416                                            t->ticket.crealm);
 417         res = krb5_principal_compare (context, p1, p2);
 418         krb5_free_principal (context, p1);
 419         krb5_free_principal (context, p2);
 420         if (!res) {
 421             ret = KRB5KRB_AP_ERR_BADMATCH;
 422             krb5_clear_error_string (context);
 423             goto out;
 424         }
 425     }
 426
 427     /* check addresses */
 428
 429     if (t->ticket.caddr
 430         && ac->remote_address
 431         && !krb5_address_search (context,
 432                                  ac->remote_address,
 433                                  t->ticket.caddr)) {
 434         ret = KRB5KRB_AP_ERR_BADADDR;
 435         krb5_clear_error_string (context);
 436         goto out;
 437     }
 438
 439     /* check timestamp in authenticator */
 440     {
 441         krb5_timestamp now;
 442
 443         krb5_timeofday (context, &now);
 444
 445         if (abs(ac->authenticator->ctime - now) > context->max_skew) {
 446             ret = KRB5KRB_AP_ERR_SKEW;
 447             krb5_clear_error_string (context);
 448             goto out;
 449         }
 450     }
 451
 452     if (ac->authenticator->seq_number)
 453         krb5_auth_con_setremoteseqnumber(context, ac,
 454                                          *ac->authenticator->seq_number);
 455
 456     /* XXX - Xor sequence numbers */
 457
 458     if (ac->authenticator->subkey) {
 459         ret = krb5_auth_con_setremotesubkey(context, ac,
 460                                             ac->authenticator->subkey);
 461         if (ret)
 462             goto out;
 463     }
 464
 465     ret = find_etypelist(context, ac, &etypes);
 466     if (ret)
 467         goto out;
 468
 469     ac->keytype = ETYPE_NULL;
 470
 471     if (etypes.val) {
 472         int i;
 473
 474         for (i = 0; i < etypes.len; i++) {
 475             if (krb5_enctype_valid(context, etypes.val[i]) == 0) {
 476                 ac->keytype = etypes.val[i];
 477                 break;
 478             }
 479         }
 480     }
 481
 482     if (ap_req_options) {
 483         *ap_req_options = 0;
 484         if (ac->keytype != ETYPE_NULL)
 485             *ap_req_options |= AP_OPTS_USE_SUBKEY;
 486         if (ap_req->ap_options.use_session_key)
 487             *ap_req_options |= AP_OPTS_USE_SESSION_KEY;
 488         if (ap_req->ap_options.mutual_required)
 489             *ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
 490     }
 491
 492     if(ticket)
 493         *ticket = t;
 494     else
 495         krb5_free_ticket (context, t);
 496     if (auth_context) {
 497         if (*auth_context == NULL)
 498             *auth_context = ac;
 499     } else
 500         krb5_auth_con_free (context, ac);
 501     free_EtypeList(&etypes);
 502     return 0;
 503  out:
 504     if (t)
 505         krb5_free_ticket (context, t);
 506     if (auth_context == NULL || *auth_context == NULL)
 507         krb5_auth_con_free (context, ac);
 508     return ret;
 509 }
 510
 511 /*
 512  *
 513  */
 514
 515 struct krb5_rd_req_in_ctx_data {
 516     krb5_keytab keytab;
 517     krb5_keyblock *keyblock;
 518     krb5_boolean check_pac;
 519 };
 520
 521 struct krb5_rd_req_out_ctx_data {
 522     krb5_keyblock *keyblock;
 523     krb5_flags ap_req_options;
 524     krb5_ticket *ticket;
 525 };
 526
 527 /*
 528  *
 529  */
 530
 531 krb5_error_code KRB5_LIB_FUNCTION
 532 krb5_rd_req_in_ctx_alloc(krb5_context context, krb5_rd_req_in_ctx *ctx)
 533 {
 534     *ctx = calloc(1, sizeof(**ctx));
 535     if (*ctx == NULL) {
 536         krb5_set_error_string(context, "out of memory");
 537         return ENOMEM;
 538     }
 539     (*ctx)->check_pac = (context->flags & KRB5_CTX_F_CHECK_PAC) ? 1 : 0;
 540     return 0;
 541 }
 542
 543 krb5_error_code KRB5_LIB_FUNCTION
 544 krb5_rd_req_in_set_keytab(krb5_context context,
 545                           krb5_rd_req_in_ctx in,
 546                           krb5_keytab keytab)
 547 {
 548     in->keytab = keytab; /* XXX should make copy */
 549     return 0;
 550 }
 551
 552 /**
 553  * Set if krb5_rq_red() is going to check the Windows PAC or not
 554  *
 555  * @param context Keberos 5 context.
 556  * @param in krb5_rd_req_in_ctx to check the option on.
 557  * @param flag flag to select if to check the pac (TRUE) or not (FALSE).
 558  *
 559  * @return Kerberos 5 error code, see krb5_get_error_message().
 560  *
 561  * @ingroup krb5
 562  */
 563
 564 krb5_error_code KRB5_LIB_FUNCTION
 565 krb5_rd_req_in_set_pac_check(krb5_context context,
 566                              krb5_rd_req_in_ctx in,
 567                              krb5_boolean flag)
 568 {
 569     in->check_pac = flag;
 570     return 0;
 571 }
 572
 573
 574 krb5_error_code KRB5_LIB_FUNCTION
 575 krb5_rd_req_in_set_keyblock(krb5_context context,
 576                             krb5_rd_req_in_ctx in,
 577                             krb5_keyblock *keyblock)
 578 {
 579     in->keyblock = keyblock; /* XXX should make copy */
 580     return 0;
 581 }
 582
 583 krb5_error_code KRB5_LIB_FUNCTION
 584 krb5_rd_req_out_get_ap_req_options(krb5_context context,
 585                                    krb5_rd_req_out_ctx out,
 586                                    krb5_flags *ap_req_options)
 587 {
 588     *ap_req_options = out->ap_req_options;
 589     return 0;
 590 }
 591
 592 krb5_error_code KRB5_LIB_FUNCTION
 593 krb5_rd_req_out_get_ticket(krb5_context context,
 594                             krb5_rd_req_out_ctx out,
 595                             krb5_ticket **ticket)
 596 {
 597     return krb5_copy_ticket(context, out->ticket, ticket);
 598 }
 599
 600 krb5_error_code KRB5_LIB_FUNCTION
 601 krb5_rd_req_out_get_keyblock(krb5_context context,
 602                             krb5_rd_req_out_ctx out,
 603                             krb5_keyblock **keyblock)
 604 {
 605     return krb5_copy_keyblock(context, out->keyblock, keyblock);
 606 }
 607
 608 void  KRB5_LIB_FUNCTION
 609 krb5_rd_req_in_ctx_free(krb5_context context, krb5_rd_req_in_ctx ctx)
 610 {
 611     free(ctx);
 612 }
 613
 614 krb5_error_code KRB5_LIB_FUNCTION
 615 _krb5_rd_req_out_ctx_alloc(krb5_context context, krb5_rd_req_out_ctx *ctx)
 616 {
 617     *ctx = calloc(1, sizeof(**ctx));
 618     if (*ctx == NULL) {
 619         krb5_set_error_string(context, "out of memory");
 620         return ENOMEM;
 621     }
 622     return 0;
 623 }
 624
 625 void  KRB5_LIB_FUNCTION
 626 krb5_rd_req_out_ctx_free(krb5_context context, krb5_rd_req_out_ctx ctx)
 627 {
 628     krb5_free_keyblock(context, ctx->keyblock);
 629     free(ctx);
 630 }
 631
 632 /*
 633  *
 634  */
 635
 636 krb5_error_code KRB5_LIB_FUNCTION
 637 krb5_rd_req(krb5_context context,
 638             krb5_auth_context *auth_context,
 639             const krb5_data *inbuf,
 640             krb5_const_principal server,
 641             krb5_keytab keytab,
 642             krb5_flags *ap_req_options,
 643             krb5_ticket **ticket)
 644 {
 645     krb5_error_code ret;
 646     krb5_rd_req_in_ctx in;
 647     krb5_rd_req_out_ctx out;
 648
 649     ret = krb5_rd_req_in_ctx_alloc(context, &in);
 650     if (ret)
 651         return ret;
 652
 653     ret = krb5_rd_req_in_set_keytab(context, in, keytab);
 654     if (ret) {
 655         krb5_rd_req_in_ctx_free(context, in);
 656         return ret;
 657     }
 658
 659     ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out);
 660     krb5_rd_req_in_ctx_free(context, in);
 661     if (ret)
 662         return ret;
 663
 664     if (ap_req_options)
 665         *ap_req_options = out->ap_req_options;
 666     if (ticket) {
 667         ret = krb5_copy_ticket(context, out->ticket, ticket);
 668         if (ret)
 669             goto out;
 670     }
 671
 672 out:
 673     krb5_rd_req_out_ctx_free(context, out);
 674     return ret;
 675 }
 676
 677 /*
 678  *
 679  */
 680
 681 krb5_error_code KRB5_LIB_FUNCTION
 682 krb5_rd_req_with_keyblock(krb5_context context,
 683                           krb5_auth_context *auth_context,
 684                           const krb5_data *inbuf,
 685                           krb5_const_principal server,
 686                           krb5_keyblock *keyblock,
 687                           krb5_flags *ap_req_options,
 688                           krb5_ticket **ticket)
 689 {
 690     krb5_error_code ret;
 691     krb5_rd_req_in_ctx in;
 692     krb5_rd_req_out_ctx out;
 693
 694     ret = krb5_rd_req_in_ctx_alloc(context, &in);
 695     if (ret)
 696         return ret;
 697
 698     ret = krb5_rd_req_in_set_keyblock(context, in, keyblock);
 699     if (ret) {
 700         krb5_rd_req_in_ctx_free(context, in);
 701         return ret;
 702     }
 703
 704     ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out);
 705     krb5_rd_req_in_ctx_free(context, in);
 706     if (ret)
 707         return ret;
 708
 709     if (ap_req_options)
 710         *ap_req_options = out->ap_req_options;
 711     if (ticket) {
 712         ret = krb5_copy_ticket(context, out->ticket, ticket);
 713         if (ret)
 714             goto out;
 715     }
 716
 717 out:
 718     krb5_rd_req_out_ctx_free(context, out);
 719     return ret;
 720 }
 721
 722 /*
 723  *
 724  */
 725
 726 static krb5_error_code
 727 get_key_from_keytab(krb5_context context,
 728                     krb5_auth_context *auth_context,
 729                     krb5_ap_req *ap_req,
 730                     krb5_const_principal server,
 731                     krb5_keytab keytab,
 732                     krb5_keyblock **out_key)
 733 {
 734     krb5_keytab_entry entry;
 735     krb5_error_code ret;
 736     int kvno;
 737     krb5_keytab real_keytab;
 738
 739     if(keytab == NULL)
 740         krb5_kt_default(context, &real_keytab);
 741     else
 742         real_keytab = keytab;
 743
 744     if (ap_req->ticket.enc_part.kvno)
 745         kvno = *ap_req->ticket.enc_part.kvno;
 746     else
 747         kvno = 0;
 748
 749     ret = krb5_kt_get_entry (context,
 750                              real_keytab,
 751                              server,
 752                              kvno,
 753                              ap_req->ticket.enc_part.etype,
 754                              &entry);
 755     if(ret)
 756         goto out;
 757     ret = krb5_copy_keyblock(context, &entry.keyblock, out_key);
 758     krb5_kt_free_entry (context, &entry);
 759 out:
 760     if(keytab == NULL)
 761         krb5_kt_close(context, real_keytab);
 762
 763     return ret;
 764 }
 765
 766 /*
 767  *
 768  */
 769
 770 krb5_error_code KRB5_LIB_FUNCTION
 771 krb5_rd_req_ctx(krb5_context context,
 772                 krb5_auth_context *auth_context,
 773                 const krb5_data *inbuf,
 774                 krb5_const_principal server,
 775                 krb5_rd_req_in_ctx inctx,
 776                 krb5_rd_req_out_ctx *outctx)
 777 {
 778     krb5_error_code ret;
 779     krb5_ap_req ap_req;
 780     krb5_principal service = NULL;
 781     krb5_rd_req_out_ctx o = NULL;
 782
 783     ret = _krb5_rd_req_out_ctx_alloc(context, &o);
 784     if (ret)
 785         goto out;
 786
 787     if (*auth_context == NULL) {
 788         ret = krb5_auth_con_init(context, auth_context);
 789         if (ret)
 790             goto out;
 791     }
 792
 793     ret = krb5_decode_ap_req(context, inbuf, &ap_req);
 794     if(ret)
 795         goto out;
 796
 797     if(server == NULL){
 798         ret = _krb5_principalname2krb5_principal(context,
 799                                                  &service,
 800                                                  ap_req.ticket.sname,
 801                                                  ap_req.ticket.realm);
 802         if (ret)
 803             goto out;
 804         server = service;
 805     }
 806     if (ap_req.ap_options.use_session_key &&
 807         (*auth_context)->keyblock == NULL) {
 808         krb5_set_error_string(context, "krb5_rd_req: user to user auth "
 809                               "without session key given");
 810         ret = KRB5KRB_AP_ERR_NOKEY;
 811         goto out;
 812     }
 813
 814     if((*auth_context)->keyblock){
 815         ret = krb5_copy_keyblock(context,
 816                                  (*auth_context)->keyblock,
 817                                  &o->keyblock);
 818         if (ret)
 819             goto out;
 820     } else if(inctx->keyblock){
 821         ret = krb5_copy_keyblock(context,
 822                                  inctx->keyblock,
 823                                  &o->keyblock);
 824         if (ret)
 825             goto out;
 826     } else {
 827         krb5_keytab keytab = NULL;
 828
 829         if (inctx && inctx->keytab)
 830             keytab = inctx->keytab;
 831
 832         ret = get_key_from_keytab(context,
 833                                   auth_context,
 834                                   &ap_req,
 835                                   server,
 836                                   keytab,
 837                                   &o->keyblock);
 838         if(ret)
 839             goto out;
 840     }
 841
 842     ret = krb5_verify_ap_req2(context,
 843                               auth_context,
 844                               &ap_req,
 845                               server,
 846                               o->keyblock,
 847                               0,
 848                               &o->ap_req_options,
 849                               &o->ticket,
 850                               KRB5_KU_AP_REQ_AUTH);
 851
 852     if (ret)
 853         goto out;
 854
 855     /* If there is a PAC, verify its server signature */
 856     if (inctx->check_pac) {
 857         krb5_pac pac;
 858         krb5_data data;
 859
 860         ret = krb5_ticket_get_authorization_data_type(context,
 861                                                       o->ticket,
 862                                                       KRB5_AUTHDATA_WIN2K_PAC,
 863                                                       &data);
 864         if (ret == 0) {
 865             ret = krb5_pac_parse(context, data.data, data.length, &pac);
 866             krb5_data_free(&data);
 867             if (ret)
 868                 goto out;
 869
 870             ret = krb5_pac_verify(context,
 871                                   pac,
 872                                   o->ticket->ticket.authtime,
 873                                   o->ticket->client,
 874                                   o->keyblock,
 875                                   NULL);
 876             krb5_pac_free(context, pac);
 877             if (ret)
 878                 goto out;
 879         }
 880         ret = 0;
 881     }
 882 out:
 883     if (ret || outctx == NULL) {
 884         krb5_rd_req_out_ctx_free(context, o);
 885     } else
 886         *outctx = o;
 887
 888     free_AP_REQ(&ap_req);
 889     if(service)
 890         krb5_free_principal(context, service);
 891     return ret;
 892 }