source4/heimdal/lib/krb5/rd_req.c

   1
   2 /*
   3  * Copyright (c) 1997 - 2007 Kungliga Tekniska Högskolan
   4  * (Royal Institute of Technology, Stockholm, Sweden).
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  *
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * 3. Neither the name of the Institute nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include "krb5_locl.h"
  36
  37 static krb5_error_code
  38 decrypt_tkt_enc_part (krb5_context context,
  39                       krb5_keyblock *key,
  40                       EncryptedData *enc_part,
  41                       EncTicketPart *decr_part)
  42 {
  43     krb5_error_code ret;
  44     krb5_data plain;
  45     size_t len;
  46     krb5_crypto crypto;
  47
  48     ret = krb5_crypto_init(context, key, 0, &crypto);
  49     if (ret)
  50         return ret;
  51     ret = krb5_decrypt_EncryptedData (context,
  52                                       crypto,
  53                                       KRB5_KU_TICKET,
  54                                       enc_part,
  55                                       &plain);
  56     krb5_crypto_destroy(context, crypto);
  57     if (ret)
  58         return ret;
  59
  60     ret = decode_EncTicketPart(plain.data, plain.length, decr_part, &len);
  61     if (ret)
  62         krb5_set_error_message(context, ret,
  63                                N_("Failed to decode encrypted "
  64                                   "ticket part", ""));
  65     krb5_data_free (&plain);
  66     return ret;
  67 }
  68
  69 static krb5_error_code
  70 decrypt_authenticator (krb5_context context,
  71                        EncryptionKey *key,
  72                        EncryptedData *enc_part,
  73                        Authenticator *authenticator,
  74                        krb5_key_usage usage)
  75 {
  76     krb5_error_code ret;
  77     krb5_data plain;
  78     size_t len;
  79     krb5_crypto crypto;
  80
  81     ret = krb5_crypto_init(context, key, 0, &crypto);
  82     if (ret)
  83         return ret;
  84     ret = krb5_decrypt_EncryptedData (context,
  85                                       crypto,
  86                                       usage /* KRB5_KU_AP_REQ_AUTH */,
  87                                       enc_part,
  88                                       &plain);
  89     /* for backwards compatibility, also try the old usage */
  90     if (ret && usage == KRB5_KU_TGS_REQ_AUTH)
  91         ret = krb5_decrypt_EncryptedData (context,
  92                                           crypto,
  93                                           KRB5_KU_AP_REQ_AUTH,
  94                                           enc_part,
  95                                           &plain);
  96     krb5_crypto_destroy(context, crypto);
  97     if (ret)
  98         return ret;
  99
 100     ret = decode_Authenticator(plain.data, plain.length,
 101                                authenticator, &len);
 102     krb5_data_free (&plain);
 103     return ret;
 104 }
 105
 106 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 107 krb5_decode_ap_req(krb5_context context,
 108                    const krb5_data *inbuf,
 109                    krb5_ap_req *ap_req)
 110 {
 111     krb5_error_code ret;
 112     size_t len;
 113     ret = decode_AP_REQ(inbuf->data, inbuf->length, ap_req, &len);
 114     if (ret)
 115         return ret;
 116     if (ap_req->pvno != 5){
 117         free_AP_REQ(ap_req);
 118         krb5_clear_error_message (context);
 119         return KRB5KRB_AP_ERR_BADVERSION;
 120     }
 121     if (ap_req->msg_type != krb_ap_req){
 122         free_AP_REQ(ap_req);
 123         krb5_clear_error_message (context);
 124         return KRB5KRB_AP_ERR_MSG_TYPE;
 125     }
 126     if (ap_req->ticket.tkt_vno != 5){
 127         free_AP_REQ(ap_req);
 128         krb5_clear_error_message (context);
 129         return KRB5KRB_AP_ERR_BADVERSION;
 130     }
 131     return 0;
 132 }
 133
 134 static krb5_error_code
 135 check_transited(krb5_context context, Ticket *ticket, EncTicketPart *enc)
 136 {
 137     char **realms;
 138     unsigned int num_realms;
 139     krb5_error_code ret;
 140
 141     /*
 142      * Windows 2000 and 2003 uses this inside their TGT so it's normaly
 143      * not seen by others, however, samba4 joined with a Windows AD as
 144      * a Domain Controller gets exposed to this.
 145      */
 146     if(enc->transited.tr_type == 0 && enc->transited.contents.length == 0)
 147         return 0;
 148
 149     if(enc->transited.tr_type != DOMAIN_X500_COMPRESS)
 150         return KRB5KDC_ERR_TRTYPE_NOSUPP;
 151
 152     if(enc->transited.contents.length == 0)
 153         return 0;
 154
 155     ret = krb5_domain_x500_decode(context, enc->transited.contents,
 156                                   &realms, &num_realms,
 157                                   enc->crealm,
 158                                   ticket->realm);
 159     if(ret)
 160         return ret;
 161     ret = krb5_check_transited(context, enc->crealm,
 162                                ticket->realm,
 163                                realms, num_realms, NULL);
 164     free(realms);
 165     return ret;
 166 }
 167
 168 static krb5_error_code
 169 find_etypelist(krb5_context context,
 170                krb5_auth_context auth_context,
 171                EtypeList *etypes)
 172 {
 173     krb5_error_code ret;
 174     krb5_authdata *ad;
 175     krb5_authdata adIfRelevant;
 176     unsigned i;
 177
 178     adIfRelevant.len = 0;
 179
 180     etypes->len = 0;
 181     etypes->val = NULL;
 182
 183     ad = auth_context->authenticator->authorization_data;
 184     if (ad == NULL)
 185         return 0;
 186
 187     for (i = 0; i < ad->len; i++) {
 188         if (ad->val[i].ad_type == KRB5_AUTHDATA_IF_RELEVANT) {
 189             ret = decode_AD_IF_RELEVANT(ad->val[i].ad_data.data,
 190                                         ad->val[i].ad_data.length,
 191                                         &adIfRelevant,
 192                                         NULL);
 193             if (ret)
 194                 return ret;
 195
 196             if (adIfRelevant.len == 1 &&
 197                 adIfRelevant.val[0].ad_type ==
 198                         KRB5_AUTHDATA_GSS_API_ETYPE_NEGOTIATION) {
 199                 break;
 200             }
 201             free_AD_IF_RELEVANT(&adIfRelevant);
 202             adIfRelevant.len = 0;
 203         }
 204     }
 205
 206     if (adIfRelevant.len == 0)
 207         return 0;
 208
 209     ret = decode_EtypeList(adIfRelevant.val[0].ad_data.data,
 210                            adIfRelevant.val[0].ad_data.length,
 211                            etypes,
 212                            NULL);
 213     if (ret)
 214         krb5_clear_error_message(context);
 215
 216     free_AD_IF_RELEVANT(&adIfRelevant);
 217
 218     return ret;
 219 }
 220
 221 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 222 krb5_decrypt_ticket(krb5_context context,
 223                     Ticket *ticket,
 224                     krb5_keyblock *key,
 225                     EncTicketPart *out,
 226                     krb5_flags flags)
 227 {
 228     EncTicketPart t;
 229     krb5_error_code ret;
 230     ret = decrypt_tkt_enc_part (context, key, &ticket->enc_part, &t);
 231     if (ret)
 232         return ret;
 233
 234     {
 235         krb5_timestamp now;
 236         time_t start = t.authtime;
 237
 238         krb5_timeofday (context, &now);
 239         if(t.starttime)
 240             start = *t.starttime;
 241         if(start - now > context->max_skew
 242            || (t.flags.invalid
 243                && !(flags & KRB5_VERIFY_AP_REQ_IGNORE_INVALID))) {
 244             free_EncTicketPart(&t);
 245             krb5_clear_error_message (context);
 246             return KRB5KRB_AP_ERR_TKT_NYV;
 247         }
 248         if(now - t.endtime > context->max_skew) {
 249             free_EncTicketPart(&t);
 250             krb5_clear_error_message (context);
 251             return KRB5KRB_AP_ERR_TKT_EXPIRED;
 252         }
 253
 254         if(!t.flags.transited_policy_checked) {
 255             ret = check_transited(context, ticket, &t);
 256             if(ret) {
 257                 free_EncTicketPart(&t);
 258                 return ret;
 259             }
 260         }
 261     }
 262
 263     if(out)
 264         *out = t;
 265     else
 266         free_EncTicketPart(&t);
 267     return 0;
 268 }
 269
 270 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 271 krb5_verify_authenticator_checksum(krb5_context context,
 272                                    krb5_auth_context ac,
 273                                    void *data,
 274                                    size_t len)
 275 {
 276     krb5_error_code ret;
 277     krb5_keyblock *key;
 278     krb5_authenticator authenticator;
 279     krb5_crypto crypto;
 280
 281     ret = krb5_auth_con_getauthenticator (context,
 282                                       ac,
 283                                       &authenticator);
 284     if(ret)
 285         return ret;
 286     if(authenticator->cksum == NULL) {
 287         krb5_free_authenticator(context, &authenticator);
 288         return -17;
 289     }
 290     ret = krb5_auth_con_getkey(context, ac, &key);
 291     if(ret) {
 292         krb5_free_authenticator(context, &authenticator);
 293         return ret;
 294     }
 295     ret = krb5_crypto_init(context, key, 0, &crypto);
 296     if(ret)
 297         goto out;
 298     ret = krb5_verify_checksum (context,
 299                                 crypto,
 300                                 KRB5_KU_AP_REQ_AUTH_CKSUM,
 301                                 data,
 302                                 len,
 303                                 authenticator->cksum);
 304     krb5_crypto_destroy(context, crypto);
 305 out:
 306     krb5_free_authenticator(context, &authenticator);
 307     krb5_free_keyblock(context, key);
 308     return ret;
 309 }
 310
 311
 312 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 313 krb5_verify_ap_req(krb5_context context,
 314                    krb5_auth_context *auth_context,
 315                    krb5_ap_req *ap_req,
 316                    krb5_const_principal server,
 317                    krb5_keyblock *keyblock,
 318                    krb5_flags flags,
 319                    krb5_flags *ap_req_options,
 320                    krb5_ticket **ticket)
 321 {
 322     return krb5_verify_ap_req2 (context,
 323                                 auth_context,
 324                                 ap_req,
 325                                 server,
 326                                 keyblock,
 327                                 flags,
 328                                 ap_req_options,
 329                                 ticket,
 330                                 KRB5_KU_AP_REQ_AUTH);
 331 }
 332
 333 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 334 krb5_verify_ap_req2(krb5_context context,
 335                     krb5_auth_context *auth_context,
 336                     krb5_ap_req *ap_req,
 337                     krb5_const_principal server,
 338                     krb5_keyblock *keyblock,
 339                     krb5_flags flags,
 340                     krb5_flags *ap_req_options,
 341                     krb5_ticket **ticket,
 342                     krb5_key_usage usage)
 343 {
 344     krb5_ticket *t;
 345     krb5_auth_context ac;
 346     krb5_error_code ret;
 347     EtypeList etypes;
 348
 349     if (ticket)
 350         *ticket = NULL;
 351
 352     if (auth_context && *auth_context) {
 353         ac = *auth_context;
 354     } else {
 355         ret = krb5_auth_con_init (context, &ac);
 356         if (ret)
 357             return ret;
 358     }
 359
 360     t = calloc(1, sizeof(*t));
 361     if (t == NULL) {
 362         ret = ENOMEM;
 363         krb5_clear_error_message (context);
 364         goto out;
 365     }
 366
 367     if (ap_req->ap_options.use_session_key && ac->keyblock){
 368         ret = krb5_decrypt_ticket(context, &ap_req->ticket,
 369                                   ac->keyblock,
 370                                   &t->ticket,
 371                                   flags);
 372         krb5_free_keyblock(context, ac->keyblock);
 373         ac->keyblock = NULL;
 374     }else
 375         ret = krb5_decrypt_ticket(context, &ap_req->ticket,
 376                                   keyblock,
 377                                   &t->ticket,
 378                                   flags);
 379
 380     if(ret)
 381         goto out;
 382
 383     ret = _krb5_principalname2krb5_principal(context,
 384                                              &t->server,
 385                                              ap_req->ticket.sname,
 386                                              ap_req->ticket.realm);
 387     if (ret) goto out;
 388     ret = _krb5_principalname2krb5_principal(context,
 389                                              &t->client,
 390                                              t->ticket.cname,
 391                                              t->ticket.crealm);
 392     if (ret) goto out;
 393
 394     ret = decrypt_authenticator (context,
 395                                  &t->ticket.key,
 396                                  &ap_req->authenticator,
 397                                  ac->authenticator,
 398                                  usage);
 399     if (ret)
 400         goto out;
 401
 402     {
 403         krb5_principal p1, p2;
 404         krb5_boolean res;
 405
 406         _krb5_principalname2krb5_principal(context,
 407                                            &p1,
 408                                            ac->authenticator->cname,
 409                                            ac->authenticator->crealm);
 410         _krb5_principalname2krb5_principal(context,
 411                                            &p2,
 412                                            t->ticket.cname,
 413                                            t->ticket.crealm);
 414         res = krb5_principal_compare (context, p1, p2);
 415         krb5_free_principal (context, p1);
 416         krb5_free_principal (context, p2);
 417         if (!res) {
 418             ret = KRB5KRB_AP_ERR_BADMATCH;
 419             krb5_clear_error_message (context);
 420             goto out;
 421         }
 422     }
 423
 424     /* check addresses */
 425
 426     if (t->ticket.caddr
 427         && ac->remote_address
 428         && !krb5_address_search (context,
 429                                  ac->remote_address,
 430                                  t->ticket.caddr)) {
 431         ret = KRB5KRB_AP_ERR_BADADDR;
 432         krb5_clear_error_message (context);
 433         goto out;
 434     }
 435
 436     /* check timestamp in authenticator */
 437     {
 438         krb5_timestamp now;
 439
 440         krb5_timeofday (context, &now);
 441
 442         if (abs(ac->authenticator->ctime - now) > context->max_skew) {
 443             ret = KRB5KRB_AP_ERR_SKEW;
 444             krb5_clear_error_message (context);
 445             goto out;
 446         }
 447     }
 448
 449     if (ac->authenticator->seq_number)
 450         krb5_auth_con_setremoteseqnumber(context, ac,
 451                                          *ac->authenticator->seq_number);
 452
 453     /* XXX - Xor sequence numbers */
 454
 455     if (ac->authenticator->subkey) {
 456         ret = krb5_auth_con_setremotesubkey(context, ac,
 457                                             ac->authenticator->subkey);
 458         if (ret)
 459             goto out;
 460     }
 461
 462     ret = find_etypelist(context, ac, &etypes);
 463     if (ret)
 464         goto out;
 465
 466     ac->keytype = ETYPE_NULL;
 467
 468     if (etypes.val) {
 469         int i;
 470
 471         for (i = 0; i < etypes.len; i++) {
 472             if (krb5_enctype_valid(context, etypes.val[i]) == 0) {
 473                 ac->keytype = etypes.val[i];
 474                 break;
 475             }
 476         }
 477     }
 478
 479     /* save key */
 480     ret = krb5_copy_keyblock(context, &t->ticket.key, &ac->keyblock);
 481     if (ret) goto out;
 482
 483     if (ap_req_options) {
 484         *ap_req_options = 0;
 485         if (ac->keytype != ETYPE_NULL)
 486             *ap_req_options |= AP_OPTS_USE_SUBKEY;
 487         if (ap_req->ap_options.use_session_key)
 488             *ap_req_options |= AP_OPTS_USE_SESSION_KEY;
 489         if (ap_req->ap_options.mutual_required)
 490             *ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
 491     }
 492
 493     if(ticket)
 494         *ticket = t;
 495     else
 496         krb5_free_ticket (context, t);
 497     if (auth_context) {
 498         if (*auth_context == NULL)
 499             *auth_context = ac;
 500     } else
 501         krb5_auth_con_free (context, ac);
 502     free_EtypeList(&etypes);
 503     return 0;
 504  out:
 505     if (t)
 506         krb5_free_ticket (context, t);
 507     if (auth_context == NULL || *auth_context == NULL)
 508         krb5_auth_con_free (context, ac);
 509     return ret;
 510 }
 511
 512 /*
 513  *
 514  */
 515
 516 struct krb5_rd_req_in_ctx_data {
 517     krb5_keytab keytab;
 518     krb5_keyblock *keyblock;
 519     krb5_boolean check_pac;
 520 };
 521
 522 struct krb5_rd_req_out_ctx_data {
 523     krb5_keyblock *keyblock;
 524     krb5_flags ap_req_options;
 525     krb5_ticket *ticket;
 526     krb5_principal server;
 527 };
 528
 529 /**
 530  * Allocate a krb5_rd_req_in_ctx as an input parameter to
 531  * krb5_rd_req_ctx(). The caller should free the context with
 532  * krb5_rd_req_in_ctx_free() when done with the context.
 533  *
 534  * @param context Keberos 5 context.
 535  * @param ctx in ctx to krb5_rd_req_ctx().
 536  *
 537  * @return Kerberos 5 error code, see krb5_get_error_message().
 538  *
 539  * @ingroup krb5_auth
 540  */
 541
 542 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 543 krb5_rd_req_in_ctx_alloc(krb5_context context, krb5_rd_req_in_ctx *ctx)
 544 {
 545     *ctx = calloc(1, sizeof(**ctx));
 546     if (*ctx == NULL) {
 547         krb5_set_error_message(context, ENOMEM,
 548                                N_("malloc: out of memory", ""));
 549         return ENOMEM;
 550     }
 551     (*ctx)->check_pac = (context->flags & KRB5_CTX_F_CHECK_PAC) ? 1 : 0;
 552     return 0;
 553 }
 554
 555 /**
 556  * Set the keytab that krb5_rd_req_ctx() will use.
 557  *
 558  * @param context Keberos 5 context.
 559  * @param in in ctx to krb5_rd_req_ctx().
 560  * @param keytab keytab that krb5_rd_req_ctx() will use, only copy the
 561  *        pointer, so the caller must free they keytab after
 562  *        krb5_rd_req_in_ctx_free() is called.
 563  *
 564  * @return Kerberos 5 error code, see krb5_get_error_message().
 565  *
 566  * @ingroup krb5_auth
 567  */
 568
 569 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 570 krb5_rd_req_in_set_keytab(krb5_context context,
 571                           krb5_rd_req_in_ctx in,
 572                           krb5_keytab keytab)
 573 {
 574     in->keytab = keytab;
 575     return 0;
 576 }
 577
 578 /**
 579  * Set if krb5_rq_red() is going to check the Windows PAC or not
 580  *
 581  * @param context Keberos 5 context.
 582  * @param in krb5_rd_req_in_ctx to check the option on.
 583  * @param flag flag to select if to check the pac (TRUE) or not (FALSE).
 584  *
 585  * @return Kerberos 5 error code, see krb5_get_error_message().
 586  *
 587  * @ingroup krb5_auth
 588  */
 589
 590 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 591 krb5_rd_req_in_set_pac_check(krb5_context context,
 592                              krb5_rd_req_in_ctx in,
 593                              krb5_boolean flag)
 594 {
 595     in->check_pac = flag;
 596     return 0;
 597 }
 598
 599
 600 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 601 krb5_rd_req_in_set_keyblock(krb5_context context,
 602                             krb5_rd_req_in_ctx in,
 603                             krb5_keyblock *keyblock)
 604 {
 605     in->keyblock = keyblock; /* XXX should make copy */
 606     return 0;
 607 }
 608
 609 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 610 krb5_rd_req_out_get_ap_req_options(krb5_context context,
 611                                    krb5_rd_req_out_ctx out,
 612                                    krb5_flags *ap_req_options)
 613 {
 614     *ap_req_options = out->ap_req_options;
 615     return 0;
 616 }
 617
 618 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 619 krb5_rd_req_out_get_ticket(krb5_context context,
 620                             krb5_rd_req_out_ctx out,
 621                             krb5_ticket **ticket)
 622 {
 623     return krb5_copy_ticket(context, out->ticket, ticket);
 624 }
 625
 626 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 627 krb5_rd_req_out_get_keyblock(krb5_context context,
 628                             krb5_rd_req_out_ctx out,
 629                             krb5_keyblock **keyblock)
 630 {
 631     return krb5_copy_keyblock(context, out->keyblock, keyblock);
 632 }
 633
 634 /**
 635  * Get the principal that was used in the request from the
 636  * client. Might not match whats in the ticket if krb5_rd_req_ctx()
 637  * searched in the keytab for a matching key.
 638  *
 639  * @param context a Kerberos 5 context.
 640  * @param out a krb5_rd_req_out_ctx from krb5_rd_req_ctx().
 641  * @param principal return principal, free with krb5_free_principal().
 642  *
 643  * @ingroup krb5_auth
 644  */
 645
 646 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 647 krb5_rd_req_out_get_server(krb5_context context,
 648                             krb5_rd_req_out_ctx out,
 649                             krb5_principal *principal)
 650 {
 651     return krb5_copy_principal(context, out->server, principal);
 652 }
 653
 654 KRB5_LIB_FUNCTION void KRB5_LIB_CALL
 655 krb5_rd_req_in_ctx_free(krb5_context context, krb5_rd_req_in_ctx ctx)
 656 {
 657     free(ctx);
 658 }
 659
 660 /**
 661  * Free the krb5_rd_req_out_ctx.
 662  *
 663  * @param context Keberos 5 context.
 664  * @param ctx krb5_rd_req_out_ctx context to free.
 665  *
 666  * @ingroup krb5_auth
 667  */
 668
 669 KRB5_LIB_FUNCTION void KRB5_LIB_CALL
 670 krb5_rd_req_out_ctx_free(krb5_context context, krb5_rd_req_out_ctx ctx)
 671 {
 672     if (ctx->ticket)
 673         krb5_free_ticket(context, ctx->ticket);
 674     if (ctx->keyblock)
 675         krb5_free_keyblock(context, ctx->keyblock);
 676     if (ctx->server)
 677         krb5_free_principal(context, ctx->server);
 678     free(ctx);
 679 }
 680
 681 /*
 682  *
 683  */
 684
 685 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 686 krb5_rd_req(krb5_context context,
 687             krb5_auth_context *auth_context,
 688             const krb5_data *inbuf,
 689             krb5_const_principal server,
 690             krb5_keytab keytab,
 691             krb5_flags *ap_req_options,
 692             krb5_ticket **ticket)
 693 {
 694     krb5_error_code ret;
 695     krb5_rd_req_in_ctx in;
 696     krb5_rd_req_out_ctx out;
 697
 698     ret = krb5_rd_req_in_ctx_alloc(context, &in);
 699     if (ret)
 700         return ret;
 701
 702     ret = krb5_rd_req_in_set_keytab(context, in, keytab);
 703     if (ret) {
 704         krb5_rd_req_in_ctx_free(context, in);
 705         return ret;
 706     }
 707
 708     ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out);
 709     krb5_rd_req_in_ctx_free(context, in);
 710     if (ret)
 711         return ret;
 712
 713     if (ap_req_options)
 714         *ap_req_options = out->ap_req_options;
 715     if (ticket) {
 716         ret = krb5_copy_ticket(context, out->ticket, ticket);
 717         if (ret)
 718             goto out;
 719     }
 720
 721 out:
 722     krb5_rd_req_out_ctx_free(context, out);
 723     return ret;
 724 }
 725
 726 /*
 727  *
 728  */
 729
 730 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 731 krb5_rd_req_with_keyblock(krb5_context context,
 732                           krb5_auth_context *auth_context,
 733                           const krb5_data *inbuf,
 734                           krb5_const_principal server,
 735                           krb5_keyblock *keyblock,
 736                           krb5_flags *ap_req_options,
 737                           krb5_ticket **ticket)
 738 {
 739     krb5_error_code ret;
 740     krb5_rd_req_in_ctx in;
 741     krb5_rd_req_out_ctx out;
 742
 743     ret = krb5_rd_req_in_ctx_alloc(context, &in);
 744     if (ret)
 745         return ret;
 746
 747     ret = krb5_rd_req_in_set_keyblock(context, in, keyblock);
 748     if (ret) {
 749         krb5_rd_req_in_ctx_free(context, in);
 750         return ret;
 751     }
 752
 753     ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out);
 754     krb5_rd_req_in_ctx_free(context, in);
 755     if (ret)
 756         return ret;
 757
 758     if (ap_req_options)
 759         *ap_req_options = out->ap_req_options;
 760     if (ticket) {
 761         ret = krb5_copy_ticket(context, out->ticket, ticket);
 762         if (ret)
 763             goto out;
 764     }
 765
 766 out:
 767     krb5_rd_req_out_ctx_free(context, out);
 768     return ret;
 769 }
 770
 771 /*
 772  *
 773  */
 774
 775 static krb5_error_code
 776 get_key_from_keytab(krb5_context context,
 777                     krb5_ap_req *ap_req,
 778                     krb5_const_principal server,
 779                     krb5_keytab keytab,
 780                     krb5_keyblock **out_key)
 781 {
 782     krb5_keytab_entry entry;
 783     krb5_error_code ret;
 784     int kvno;
 785     krb5_keytab real_keytab;
 786
 787     if(keytab == NULL)
 788         krb5_kt_default(context, &real_keytab);
 789     else
 790         real_keytab = keytab;
 791
 792     if (ap_req->ticket.enc_part.kvno)
 793         kvno = *ap_req->ticket.enc_part.kvno;
 794     else
 795         kvno = 0;
 796
 797     ret = krb5_kt_get_entry (context,
 798                              real_keytab,
 799                              server,
 800                              kvno,
 801                              ap_req->ticket.enc_part.etype,
 802                              &entry);
 803     if(ret)
 804         goto out;
 805     ret = krb5_copy_keyblock(context, &entry.keyblock, out_key);
 806     krb5_kt_free_entry (context, &entry);
 807 out:
 808     if(keytab == NULL)
 809         krb5_kt_close(context, real_keytab);
 810
 811     return ret;
 812 }
 813
 814 /**
 815  * The core server function that verify application authentication
 816  * requests from clients.
 817  *
 818  * @param context Keberos 5 context.
 819  * @param auth_context the authentication context, can be NULL, then
 820  *        default values for the authentication context will used.
 821  * @param inbuf the (AP-REQ) authentication buffer
 822  *
 823  * @param server the server with authenticate as, if NULL the function
 824  *        will try to find any avaiable credentintial in the keytab
 825  *        that will verify the reply. The function will prefer the
 826  *        server the server client specified in the AP-REQ, but if
 827  *        there is no mach, it will try all keytab entries for a
 828  *        match. This have serious performance issues for larger keytabs.
 829  *
 830  * @param inctx control the behavior of the function, if NULL, the
 831  *        default behavior is used.
 832  * @param outctx the return outctx, free with krb5_rd_req_out_ctx_free().
 833  * @return Kerberos 5 error code, see krb5_get_error_message().
 834  *
 835  * @ingroup krb5_auth
 836  */
 837
 838 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 839 krb5_rd_req_ctx(krb5_context context,
 840                 krb5_auth_context *auth_context,
 841                 const krb5_data *inbuf,
 842                 krb5_const_principal server,
 843                 krb5_rd_req_in_ctx inctx,
 844                 krb5_rd_req_out_ctx *outctx)
 845 {
 846     krb5_error_code ret;
 847     krb5_ap_req ap_req;
 848     krb5_rd_req_out_ctx o = NULL;
 849     krb5_keytab id = NULL, keytab = NULL;
 850     krb5_principal service = NULL;
 851
 852     *outctx = NULL;
 853
 854     o = calloc(1, sizeof(*o));
 855     if (o == NULL) {
 856         krb5_set_error_message(context, ENOMEM,
 857                                N_("malloc: out of memory", ""));
 858         return ENOMEM;
 859     }
 860
 861     if (*auth_context == NULL) {
 862         ret = krb5_auth_con_init(context, auth_context);
 863         if (ret)
 864             goto out;
 865     }
 866
 867     ret = krb5_decode_ap_req(context, inbuf, &ap_req);
 868     if(ret)
 869         goto out;
 870
 871     /* Save that principal that was in the request */
 872     ret = _krb5_principalname2krb5_principal(context,
 873                                              &o->server,
 874                                              ap_req.ticket.sname,
 875                                              ap_req.ticket.realm);
 876     if (ret)
 877         goto out;
 878
 879     if (ap_req.ap_options.use_session_key &&
 880         (*auth_context)->keyblock == NULL) {
 881         ret = KRB5KRB_AP_ERR_NOKEY;
 882         krb5_set_error_message(context, ret,
 883                                N_("krb5_rd_req: user to user auth "
 884                                   "without session key given", ""));
 885         goto out;
 886     }
 887
 888     if (inctx && inctx->keytab)
 889         id = inctx->keytab;
 890
 891     if((*auth_context)->keyblock){
 892         ret = krb5_copy_keyblock(context,
 893                                  (*auth_context)->keyblock,
 894                                  &o->keyblock);
 895         if (ret)
 896             goto out;
 897     } else if(inctx && inctx->keyblock){
 898         ret = krb5_copy_keyblock(context,
 899                                  inctx->keyblock,
 900                                  &o->keyblock);
 901         if (ret)
 902             goto out;
 903     } else {
 904
 905         if(id == NULL) {
 906             krb5_kt_default(context, &keytab);
 907             id = keytab;
 908         }
 909         if (id == NULL)
 910             goto out;
 911
 912         if (server == NULL) {
 913             ret = _krb5_principalname2krb5_principal(context,
 914                                                      &service,
 915                                                      ap_req.ticket.sname,
 916                                                      ap_req.ticket.realm);
 917             if (ret)
 918                 goto out;
 919             server = service;
 920         }
 921
 922         ret = get_key_from_keytab(context,
 923                                   &ap_req,
 924                                   server,
 925                                   id,
 926                                   &o->keyblock);
 927         if (ret) {
 928             /* If caller specified a server, fail. */
 929             if (service == NULL)
 930                 goto out;
 931             /* Otherwise, fall back to iterating over the keytab. This
 932              * have serious performace issues for larger keytab.
 933              */
 934             o->keyblock = NULL;
 935         }
 936     }
 937
 938     if (o->keyblock) {
 939         /*
 940          * We got an exact keymatch, use that.
 941          */
 942
 943         ret = krb5_verify_ap_req2(context,
 944                                   auth_context,
 945                                   &ap_req,
 946                                   server,
 947                                   o->keyblock,
 948                                   0,
 949                                   &o->ap_req_options,
 950                                   &o->ticket,
 951                                   KRB5_KU_AP_REQ_AUTH);
 952
 953         if (ret)
 954             goto out;
 955
 956     } else {
 957         /*
 958          * Interate over keytab to find a key that can decrypt the request.
 959          */
 960
 961         krb5_keytab_entry entry;
 962         krb5_kt_cursor cursor;
 963         int done = 0, kvno = 0;
 964
 965         memset(&cursor, 0, sizeof(cursor));
 966
 967         if (ap_req.ticket.enc_part.kvno)
 968             kvno = *ap_req.ticket.enc_part.kvno;
 969
 970         ret = krb5_kt_start_seq_get(context, id, &cursor);
 971         if (ret)
 972             goto out;
 973
 974         done = 0;
 975         while (!done) {
 976             krb5_principal p;
 977
 978             ret = krb5_kt_next_entry(context, id, &entry, &cursor);
 979             if (ret) {
 980                 _krb5_kt_principal_not_found(context, ret, id, o->server,
 981                                              ap_req.ticket.enc_part.etype,
 982                                              kvno);
 983                 goto out;
 984             }
 985
 986             if (entry.keyblock.keytype != ap_req.ticket.enc_part.etype ||
 987                 (kvno && kvno != entry.vno)) {
 988                 krb5_kt_free_entry (context, &entry);
 989                 continue;
 990             }
 991
 992             ret = krb5_verify_ap_req2(context,
 993                                       auth_context,
 994                                       &ap_req,
 995                                       server,
 996                                       &entry.keyblock,
 997                                       0,
 998                                       &o->ap_req_options,
 999                                       &o->ticket,
1000                                       KRB5_KU_AP_REQ_AUTH);
1001             if (ret) {
1002                 krb5_kt_free_entry (context, &entry);
1003                 continue;
1004             }
1005
1006             /*
1007              * Found a match, save the keyblock for PAC processing,
1008              * and update the service principal in the ticket to match
1009              * whatever is in the keytab.
1010              */
1011
1012             ret = krb5_copy_keyblock(context,
1013                                      &entry.keyblock,
1014                                      &o->keyblock);
1015             if (ret) {
1016                 krb5_kt_free_entry (context, &entry);
1017                 goto out;
1018             }
1019
1020             ret = krb5_copy_principal(context, entry.principal, &p);
1021             if (ret) {
1022                 krb5_kt_free_entry (context, &entry);
1023                 goto out;
1024             }
1025             krb5_free_principal(context, o->ticket->server);
1026             o->ticket->server = p;
1027
1028             krb5_kt_free_entry (context, &entry);
1029
1030             done = 1;
1031         }
1032         krb5_kt_end_seq_get (context, id, &cursor);
1033     }
1034
1035     /* If there is a PAC, verify its server signature */
1036     if (inctx == NULL || inctx->check_pac) {
1037         krb5_pac pac;
1038         krb5_data data;
1039
1040         ret = krb5_ticket_get_authorization_data_type(context,
1041                                                       o->ticket,
1042                                                       KRB5_AUTHDATA_WIN2K_PAC,
1043                                                       &data);
1044         if (ret == 0) {
1045             ret = krb5_pac_parse(context, data.data, data.length, &pac);
1046             krb5_data_free(&data);
1047             if (ret)
1048                 goto out;
1049
1050             ret = krb5_pac_verify(context,
1051                                   pac,
1052                                   o->ticket->ticket.authtime,
1053                                   o->ticket->client,
1054                                   o->keyblock,
1055                                   NULL);
1056             krb5_pac_free(context, pac);
1057             if (ret)
1058                 goto out;
1059         } else
1060           ret = 0;
1061     }
1062 out:
1063
1064     if (ret || outctx == NULL) {
1065         krb5_rd_req_out_ctx_free(context, o);
1066     } else
1067         *outctx = o;
1068
1069     free_AP_REQ(&ap_req);
1070
1071     if (service)
1072         krb5_free_principal(context, service);
1073
1074     if (keytab)
1075         krb5_kt_close(context, keytab);
1076
1077     return ret;
1078 }