crypto/external/bsd/heimdal/dist/lib/krb5/rd_req.c

   1 /*      $NetBSD: rd_req.c,v 1.1.1.2 2014/04/24 12:45:51 pettai Exp $    */
   2
   3
   4 /*
   5  * Copyright (c) 1997 - 2007 Kungliga Tekniska Högskolan
   6  * (Royal Institute of Technology, Stockholm, Sweden).
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  *
  20  * 3. Neither the name of the Institute nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36
  37 #include "krb5_locl.h"
  38
  39 static krb5_error_code
  40 decrypt_tkt_enc_part (krb5_context context,
  41                       krb5_keyblock *key,
  42                       EncryptedData *enc_part,
  43                       EncTicketPart *decr_part)
  44 {
  45     krb5_error_code ret;
  46     krb5_data plain;
  47     size_t len;
  48     krb5_crypto crypto;
  49
  50     ret = krb5_crypto_init(context, key, 0, &crypto);
  51     if (ret)
  52         return ret;
  53     ret = krb5_decrypt_EncryptedData (context,
  54                                       crypto,
  55                                       KRB5_KU_TICKET,
  56                                       enc_part,
  57                                       &plain);
  58     krb5_crypto_destroy(context, crypto);
  59     if (ret)
  60         return ret;
  61
  62     ret = decode_EncTicketPart(plain.data, plain.length, decr_part, &len);
  63     if (ret)
  64         krb5_set_error_message(context, ret,
  65                                N_("Failed to decode encrypted "
  66                                   "ticket part", ""));
  67     krb5_data_free (&plain);
  68     return ret;
  69 }
  70
  71 static krb5_error_code
  72 decrypt_authenticator (krb5_context context,
  73                        EncryptionKey *key,
  74                        EncryptedData *enc_part,
  75                        Authenticator *authenticator,
  76                        krb5_key_usage usage)
  77 {
  78     krb5_error_code ret;
  79     krb5_data plain;
  80     size_t len;
  81     krb5_crypto crypto;
  82
  83     ret = krb5_crypto_init(context, key, 0, &crypto);
  84     if (ret)
  85         return ret;
  86     ret = krb5_decrypt_EncryptedData (context,
  87                                       crypto,
  88                                       usage /* KRB5_KU_AP_REQ_AUTH */,
  89                                       enc_part,
  90                                       &plain);
  91     /* for backwards compatibility, also try the old usage */
  92     if (ret && usage == KRB5_KU_TGS_REQ_AUTH)
  93         ret = krb5_decrypt_EncryptedData (context,
  94                                           crypto,
  95                                           KRB5_KU_AP_REQ_AUTH,
  96                                           enc_part,
  97                                           &plain);
  98     krb5_crypto_destroy(context, crypto);
  99     if (ret)
 100         return ret;
 101
 102     ret = decode_Authenticator(plain.data, plain.length,
 103                                authenticator, &len);
 104     krb5_data_free (&plain);
 105     return ret;
 106 }
 107
 108 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 109 krb5_decode_ap_req(krb5_context context,
 110                    const krb5_data *inbuf,
 111                    krb5_ap_req *ap_req)
 112 {
 113     krb5_error_code ret;
 114     size_t len;
 115     ret = decode_AP_REQ(inbuf->data, inbuf->length, ap_req, &len);
 116     if (ret)
 117         return ret;
 118     if (ap_req->pvno != 5){
 119         free_AP_REQ(ap_req);
 120         krb5_clear_error_message (context);
 121         return KRB5KRB_AP_ERR_BADVERSION;
 122     }
 123     if (ap_req->msg_type != krb_ap_req){
 124         free_AP_REQ(ap_req);
 125         krb5_clear_error_message (context);
 126         return KRB5KRB_AP_ERR_MSG_TYPE;
 127     }
 128     if (ap_req->ticket.tkt_vno != 5){
 129         free_AP_REQ(ap_req);
 130         krb5_clear_error_message (context);
 131         return KRB5KRB_AP_ERR_BADVERSION;
 132     }
 133     return 0;
 134 }
 135
 136 static krb5_error_code
 137 check_transited(krb5_context context, Ticket *ticket, EncTicketPart *enc)
 138 {
 139     char **realms;
 140     unsigned int num_realms, n;
 141     krb5_error_code ret;
 142
 143     /*
 144      * Windows 2000 and 2003 uses this inside their TGT so it's normaly
 145      * not seen by others, however, samba4 joined with a Windows AD as
 146      * a Domain Controller gets exposed to this.
 147      */
 148     if(enc->transited.tr_type == 0 && enc->transited.contents.length == 0)
 149         return 0;
 150
 151     if(enc->transited.tr_type != DOMAIN_X500_COMPRESS)
 152         return KRB5KDC_ERR_TRTYPE_NOSUPP;
 153
 154     if(enc->transited.contents.length == 0)
 155         return 0;
 156
 157     ret = krb5_domain_x500_decode(context, enc->transited.contents,
 158                                   &realms, &num_realms,
 159                                   enc->crealm,
 160                                   ticket->realm);
 161     if(ret)
 162         return ret;
 163     ret = krb5_check_transited(context, enc->crealm,
 164                                ticket->realm,
 165                                realms, num_realms, NULL);
 166     for (n = 0; n < num_realms; n++)
 167         free(realms[n]);
 168     free(realms);
 169     return ret;
 170 }
 171
 172 static krb5_error_code
 173 find_etypelist(krb5_context context,
 174                krb5_auth_context auth_context,
 175                EtypeList *etypes)
 176 {
 177     krb5_error_code ret;
 178     krb5_authdata *ad;
 179     krb5_authdata adIfRelevant;
 180     unsigned i;
 181
 182     memset(&adIfRelevant, 0, sizeof(adIfRelevant));
 183
 184     etypes->len = 0;
 185     etypes->val = NULL;
 186
 187     ad = auth_context->authenticator->authorization_data;
 188     if (ad == NULL)
 189         return 0;
 190
 191     for (i = 0; i < ad->len; i++) {
 192         if (ad->val[i].ad_type == KRB5_AUTHDATA_IF_RELEVANT) {
 193             ret = decode_AD_IF_RELEVANT(ad->val[i].ad_data.data,
 194                                         ad->val[i].ad_data.length,
 195                                         &adIfRelevant,
 196                                         NULL);
 197             if (ret)
 198                 return ret;
 199
 200             if (adIfRelevant.len == 1 &&
 201                 adIfRelevant.val[0].ad_type ==
 202                         KRB5_AUTHDATA_GSS_API_ETYPE_NEGOTIATION) {
 203                 break;
 204             }
 205             free_AD_IF_RELEVANT(&adIfRelevant);
 206             adIfRelevant.len = 0;
 207         }
 208     }
 209
 210     if (adIfRelevant.len == 0)
 211         return 0;
 212
 213     ret = decode_EtypeList(adIfRelevant.val[0].ad_data.data,
 214                            adIfRelevant.val[0].ad_data.length,
 215                            etypes,
 216                            NULL);
 217     if (ret)
 218         krb5_clear_error_message(context);
 219
 220     free_AD_IF_RELEVANT(&adIfRelevant);
 221
 222     return ret;
 223 }
 224
 225 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 226 krb5_decrypt_ticket(krb5_context context,
 227                     Ticket *ticket,
 228                     krb5_keyblock *key,
 229                     EncTicketPart *out,
 230                     krb5_flags flags)
 231 {
 232     EncTicketPart t;
 233     krb5_error_code ret;
 234     ret = decrypt_tkt_enc_part (context, key, &ticket->enc_part, &t);
 235     if (ret)
 236         return ret;
 237
 238     {
 239         krb5_timestamp now;
 240         time_t start = t.authtime;
 241
 242         krb5_timeofday (context, &now);
 243         if(t.starttime)
 244             start = *t.starttime;
 245         if(start - now > context->max_skew
 246            || (t.flags.invalid
 247                && !(flags & KRB5_VERIFY_AP_REQ_IGNORE_INVALID))) {
 248             free_EncTicketPart(&t);
 249             krb5_clear_error_message (context);
 250             return KRB5KRB_AP_ERR_TKT_NYV;
 251         }
 252         if(now - t.endtime > context->max_skew) {
 253             free_EncTicketPart(&t);
 254             krb5_clear_error_message (context);
 255             return KRB5KRB_AP_ERR_TKT_EXPIRED;
 256         }
 257
 258         if(!t.flags.transited_policy_checked) {
 259             ret = check_transited(context, ticket, &t);
 260             if(ret) {
 261                 free_EncTicketPart(&t);
 262                 return ret;
 263             }
 264         }
 265     }
 266
 267     if(out)
 268         *out = t;
 269     else
 270         free_EncTicketPart(&t);
 271     return 0;
 272 }
 273
 274 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 275 krb5_verify_authenticator_checksum(krb5_context context,
 276                                    krb5_auth_context ac,
 277                                    void *data,
 278                                    size_t len)
 279 {
 280     krb5_error_code ret;
 281     krb5_keyblock *key;
 282     krb5_authenticator authenticator;
 283     krb5_crypto crypto;
 284
 285     ret = krb5_auth_con_getauthenticator (context,
 286                                       ac,
 287                                       &authenticator);
 288     if(ret)
 289         return ret;
 290     if(authenticator->cksum == NULL) {
 291         krb5_free_authenticator(context, &authenticator);
 292         return -17;
 293     }
 294     ret = krb5_auth_con_getkey(context, ac, &key);
 295     if(ret) {
 296         krb5_free_authenticator(context, &authenticator);
 297         return ret;
 298     }
 299     ret = krb5_crypto_init(context, key, 0, &crypto);
 300     if(ret)
 301         goto out;
 302     ret = krb5_verify_checksum (context,
 303                                 crypto,
 304                                 KRB5_KU_AP_REQ_AUTH_CKSUM,
 305                                 data,
 306                                 len,
 307                                 authenticator->cksum);
 308     krb5_crypto_destroy(context, crypto);
 309 out:
 310     krb5_free_authenticator(context, &authenticator);
 311     krb5_free_keyblock(context, key);
 312     return ret;
 313 }
 314
 315
 316 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 317 krb5_verify_ap_req(krb5_context context,
 318                    krb5_auth_context *auth_context,
 319                    krb5_ap_req *ap_req,
 320                    krb5_const_principal server,
 321                    krb5_keyblock *keyblock,
 322                    krb5_flags flags,
 323                    krb5_flags *ap_req_options,
 324                    krb5_ticket **ticket)
 325 {
 326     return krb5_verify_ap_req2 (context,
 327                                 auth_context,
 328                                 ap_req,
 329                                 server,
 330                                 keyblock,
 331                                 flags,
 332                                 ap_req_options,
 333                                 ticket,
 334                                 KRB5_KU_AP_REQ_AUTH);
 335 }
 336
 337 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 338 krb5_verify_ap_req2(krb5_context context,
 339                     krb5_auth_context *auth_context,
 340                     krb5_ap_req *ap_req,
 341                     krb5_const_principal server,
 342                     krb5_keyblock *keyblock,
 343                     krb5_flags flags,
 344                     krb5_flags *ap_req_options,
 345                     krb5_ticket **ticket,
 346                     krb5_key_usage usage)
 347 {
 348     krb5_ticket *t;
 349     krb5_auth_context ac;
 350     krb5_error_code ret;
 351     EtypeList etypes;
 352
 353     if (ticket)
 354         *ticket = NULL;
 355
 356     if (auth_context && *auth_context) {
 357         ac = *auth_context;
 358     } else {
 359         ret = krb5_auth_con_init (context, &ac);
 360         if (ret)
 361             return ret;
 362     }
 363
 364     t = calloc(1, sizeof(*t));
 365     if (t == NULL) {
 366         ret = ENOMEM;
 367         krb5_clear_error_message (context);
 368         goto out;
 369     }
 370
 371     if (ap_req->ap_options.use_session_key && ac->keyblock){
 372         ret = krb5_decrypt_ticket(context, &ap_req->ticket,
 373                                   ac->keyblock,
 374                                   &t->ticket,
 375                                   flags);
 376         krb5_free_keyblock(context, ac->keyblock);
 377         ac->keyblock = NULL;
 378     }else
 379         ret = krb5_decrypt_ticket(context, &ap_req->ticket,
 380                                   keyblock,
 381                                   &t->ticket,
 382                                   flags);
 383
 384     if(ret)
 385         goto out;
 386
 387     ret = _krb5_principalname2krb5_principal(context,
 388                                              &t->server,
 389                                              ap_req->ticket.sname,
 390                                              ap_req->ticket.realm);
 391     if (ret) goto out;
 392     ret = _krb5_principalname2krb5_principal(context,
 393                                              &t->client,
 394                                              t->ticket.cname,
 395                                              t->ticket.crealm);
 396     if (ret) goto out;
 397
 398     ret = decrypt_authenticator (context,
 399                                  &t->ticket.key,
 400                                  &ap_req->authenticator,
 401                                  ac->authenticator,
 402                                  usage);
 403     if (ret)
 404         goto out;
 405
 406     {
 407         krb5_principal p1, p2;
 408         krb5_boolean res;
 409
 410         _krb5_principalname2krb5_principal(context,
 411                                            &p1,
 412                                            ac->authenticator->cname,
 413                                            ac->authenticator->crealm);
 414         _krb5_principalname2krb5_principal(context,
 415                                            &p2,
 416                                            t->ticket.cname,
 417                                            t->ticket.crealm);
 418         res = krb5_principal_compare (context, p1, p2);
 419         krb5_free_principal (context, p1);
 420         krb5_free_principal (context, p2);
 421         if (!res) {
 422             ret = KRB5KRB_AP_ERR_BADMATCH;
 423             krb5_clear_error_message (context);
 424             goto out;
 425         }
 426     }
 427
 428     /* check addresses */
 429
 430     if (t->ticket.caddr
 431         && ac->remote_address
 432         && !krb5_address_search (context,
 433                                  ac->remote_address,
 434                                  t->ticket.caddr)) {
 435         ret = KRB5KRB_AP_ERR_BADADDR;
 436         krb5_clear_error_message (context);
 437         goto out;
 438     }
 439
 440     /* check timestamp in authenticator */
 441     {
 442         krb5_timestamp now;
 443
 444         krb5_timeofday (context, &now);
 445
 446         if (abs(ac->authenticator->ctime - now) > context->max_skew) {
 447             ret = KRB5KRB_AP_ERR_SKEW;
 448             krb5_clear_error_message (context);
 449             goto out;
 450         }
 451     }
 452
 453     if (ac->authenticator->seq_number)
 454         krb5_auth_con_setremoteseqnumber(context, ac,
 455                                          *ac->authenticator->seq_number);
 456
 457     /* XXX - Xor sequence numbers */
 458
 459     if (ac->authenticator->subkey) {
 460         ret = krb5_auth_con_setremotesubkey(context, ac,
 461                                             ac->authenticator->subkey);
 462         if (ret)
 463             goto out;
 464     }
 465
 466     ret = find_etypelist(context, ac, &etypes);
 467     if (ret)
 468         goto out;
 469
 470     ac->keytype = ETYPE_NULL;
 471
 472     if (etypes.val) {
 473         size_t i;
 474
 475         for (i = 0; i < etypes.len; i++) {
 476             if (krb5_enctype_valid(context, etypes.val[i]) == 0) {
 477                 ac->keytype = etypes.val[i];
 478                 break;
 479             }
 480         }
 481     }
 482
 483     /* save key */
 484     ret = krb5_copy_keyblock(context, &t->ticket.key, &ac->keyblock);
 485     if (ret) goto out;
 486
 487     if (ap_req_options) {
 488         *ap_req_options = 0;
 489         if (ac->keytype != ETYPE_NULL)
 490             *ap_req_options |= AP_OPTS_USE_SUBKEY;
 491         if (ap_req->ap_options.use_session_key)
 492             *ap_req_options |= AP_OPTS_USE_SESSION_KEY;
 493         if (ap_req->ap_options.mutual_required)
 494             *ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
 495     }
 496
 497     if(ticket)
 498         *ticket = t;
 499     else
 500         krb5_free_ticket (context, t);
 501     if (auth_context) {
 502         if (*auth_context == NULL)
 503             *auth_context = ac;
 504     } else
 505         krb5_auth_con_free (context, ac);
 506     free_EtypeList(&etypes);
 507     return 0;
 508  out:
 509     if (t)
 510         krb5_free_ticket (context, t);
 511     if (auth_context == NULL || *auth_context == NULL)
 512         krb5_auth_con_free (context, ac);
 513     return ret;
 514 }
 515
 516 /*
 517  *
 518  */
 519
 520 struct krb5_rd_req_in_ctx_data {
 521     krb5_keytab keytab;
 522     krb5_keyblock *keyblock;
 523     krb5_boolean check_pac;
 524 };
 525
 526 struct krb5_rd_req_out_ctx_data {
 527     krb5_keyblock *keyblock;
 528     krb5_flags ap_req_options;
 529     krb5_ticket *ticket;
 530     krb5_principal server;
 531 };
 532
 533 /**
 534  * Allocate a krb5_rd_req_in_ctx as an input parameter to
 535  * krb5_rd_req_ctx(). The caller should free the context with
 536  * krb5_rd_req_in_ctx_free() when done with the context.
 537  *
 538  * @param context Keberos 5 context.
 539  * @param ctx in ctx to krb5_rd_req_ctx().
 540  *
 541  * @return Kerberos 5 error code, see krb5_get_error_message().
 542  *
 543  * @ingroup krb5_auth
 544  */
 545
 546 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 547 krb5_rd_req_in_ctx_alloc(krb5_context context, krb5_rd_req_in_ctx *ctx)
 548 {
 549     *ctx = calloc(1, sizeof(**ctx));
 550     if (*ctx == NULL) {
 551         krb5_set_error_message(context, ENOMEM,
 552                                N_("malloc: out of memory", ""));
 553         return ENOMEM;
 554     }
 555     (*ctx)->check_pac = (context->flags & KRB5_CTX_F_CHECK_PAC) ? 1 : 0;
 556     return 0;
 557 }
 558
 559 /**
 560  * Set the keytab that krb5_rd_req_ctx() will use.
 561  *
 562  * @param context Keberos 5 context.
 563  * @param in in ctx to krb5_rd_req_ctx().
 564  * @param keytab keytab that krb5_rd_req_ctx() will use, only copy the
 565  *        pointer, so the caller must free they keytab after
 566  *        krb5_rd_req_in_ctx_free() is called.
 567  *
 568  * @return Kerberos 5 error code, see krb5_get_error_message().
 569  *
 570  * @ingroup krb5_auth
 571  */
 572
 573 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 574 krb5_rd_req_in_set_keytab(krb5_context context,
 575                           krb5_rd_req_in_ctx in,
 576                           krb5_keytab keytab)
 577 {
 578     in->keytab = keytab;
 579     return 0;
 580 }
 581
 582 /**
 583  * Set if krb5_rq_red() is going to check the Windows PAC or not
 584  *
 585  * @param context Keberos 5 context.
 586  * @param in krb5_rd_req_in_ctx to check the option on.
 587  * @param flag flag to select if to check the pac (TRUE) or not (FALSE).
 588  *
 589  * @return Kerberos 5 error code, see krb5_get_error_message().
 590  *
 591  * @ingroup krb5_auth
 592  */
 593
 594 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 595 krb5_rd_req_in_set_pac_check(krb5_context context,
 596                              krb5_rd_req_in_ctx in,
 597                              krb5_boolean flag)
 598 {
 599     in->check_pac = flag;
 600     return 0;
 601 }
 602
 603
 604 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 605 krb5_rd_req_in_set_keyblock(krb5_context context,
 606                             krb5_rd_req_in_ctx in,
 607                             krb5_keyblock *keyblock)
 608 {
 609     in->keyblock = keyblock; /* XXX should make copy */
 610     return 0;
 611 }
 612
 613 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 614 krb5_rd_req_out_get_ap_req_options(krb5_context context,
 615                                    krb5_rd_req_out_ctx out,
 616                                    krb5_flags *ap_req_options)
 617 {
 618     *ap_req_options = out->ap_req_options;
 619     return 0;
 620 }
 621
 622 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 623 krb5_rd_req_out_get_ticket(krb5_context context,
 624                             krb5_rd_req_out_ctx out,
 625                             krb5_ticket **ticket)
 626 {
 627     return krb5_copy_ticket(context, out->ticket, ticket);
 628 }
 629
 630 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 631 krb5_rd_req_out_get_keyblock(krb5_context context,
 632                             krb5_rd_req_out_ctx out,
 633                             krb5_keyblock **keyblock)
 634 {
 635     return krb5_copy_keyblock(context, out->keyblock, keyblock);
 636 }
 637
 638 /**
 639  * Get the principal that was used in the request from the
 640  * client. Might not match whats in the ticket if krb5_rd_req_ctx()
 641  * searched in the keytab for a matching key.
 642  *
 643  * @param context a Kerberos 5 context.
 644  * @param out a krb5_rd_req_out_ctx from krb5_rd_req_ctx().
 645  * @param principal return principal, free with krb5_free_principal().
 646  *
 647  * @ingroup krb5_auth
 648  */
 649
 650 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 651 krb5_rd_req_out_get_server(krb5_context context,
 652                             krb5_rd_req_out_ctx out,
 653                             krb5_principal *principal)
 654 {
 655     return krb5_copy_principal(context, out->server, principal);
 656 }
 657
 658 KRB5_LIB_FUNCTION void KRB5_LIB_CALL
 659 krb5_rd_req_in_ctx_free(krb5_context context, krb5_rd_req_in_ctx ctx)
 660 {
 661     free(ctx);
 662 }
 663
 664 /**
 665  * Free the krb5_rd_req_out_ctx.
 666  *
 667  * @param context Keberos 5 context.
 668  * @param ctx krb5_rd_req_out_ctx context to free.
 669  *
 670  * @ingroup krb5_auth
 671  */
 672
 673 KRB5_LIB_FUNCTION void KRB5_LIB_CALL
 674 krb5_rd_req_out_ctx_free(krb5_context context, krb5_rd_req_out_ctx ctx)
 675 {
 676     if (ctx->ticket)
 677         krb5_free_ticket(context, ctx->ticket);
 678     if (ctx->keyblock)
 679         krb5_free_keyblock(context, ctx->keyblock);
 680     if (ctx->server)
 681         krb5_free_principal(context, ctx->server);
 682     free(ctx);
 683 }
 684
 685 /*
 686  *
 687  */
 688
 689 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 690 krb5_rd_req(krb5_context context,
 691             krb5_auth_context *auth_context,
 692             const krb5_data *inbuf,
 693             krb5_const_principal server,
 694             krb5_keytab keytab,
 695             krb5_flags *ap_req_options,
 696             krb5_ticket **ticket)
 697 {
 698     krb5_error_code ret;
 699     krb5_rd_req_in_ctx in;
 700     krb5_rd_req_out_ctx out;
 701
 702     ret = krb5_rd_req_in_ctx_alloc(context, &in);
 703     if (ret)
 704         return ret;
 705
 706     ret = krb5_rd_req_in_set_keytab(context, in, keytab);
 707     if (ret) {
 708         krb5_rd_req_in_ctx_free(context, in);
 709         return ret;
 710     }
 711
 712     ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out);
 713     krb5_rd_req_in_ctx_free(context, in);
 714     if (ret)
 715         return ret;
 716
 717     if (ap_req_options)
 718         *ap_req_options = out->ap_req_options;
 719     if (ticket) {
 720         ret = krb5_copy_ticket(context, out->ticket, ticket);
 721         if (ret)
 722             goto out;
 723     }
 724
 725 out:
 726     krb5_rd_req_out_ctx_free(context, out);
 727     return ret;
 728 }
 729
 730 /*
 731  *
 732  */
 733
 734 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 735 krb5_rd_req_with_keyblock(krb5_context context,
 736                           krb5_auth_context *auth_context,
 737                           const krb5_data *inbuf,
 738                           krb5_const_principal server,
 739                           krb5_keyblock *keyblock,
 740                           krb5_flags *ap_req_options,
 741                           krb5_ticket **ticket)
 742 {
 743     krb5_error_code ret;
 744     krb5_rd_req_in_ctx in;
 745     krb5_rd_req_out_ctx out;
 746
 747     ret = krb5_rd_req_in_ctx_alloc(context, &in);
 748     if (ret)
 749         return ret;
 750
 751     ret = krb5_rd_req_in_set_keyblock(context, in, keyblock);
 752     if (ret) {
 753         krb5_rd_req_in_ctx_free(context, in);
 754         return ret;
 755     }
 756
 757     ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out);
 758     krb5_rd_req_in_ctx_free(context, in);
 759     if (ret)
 760         return ret;
 761
 762     if (ap_req_options)
 763         *ap_req_options = out->ap_req_options;
 764     if (ticket) {
 765         ret = krb5_copy_ticket(context, out->ticket, ticket);
 766         if (ret)
 767             goto out;
 768     }
 769
 770 out:
 771     krb5_rd_req_out_ctx_free(context, out);
 772     return ret;
 773 }
 774
 775 /*
 776  *
 777  */
 778
 779 static krb5_error_code
 780 get_key_from_keytab(krb5_context context,
 781                     krb5_ap_req *ap_req,
 782                     krb5_const_principal server,
 783                     krb5_keytab keytab,
 784                     krb5_keyblock **out_key)
 785 {
 786     krb5_keytab_entry entry;
 787     krb5_error_code ret;
 788     int kvno;
 789     krb5_keytab real_keytab;
 790
 791     if(keytab == NULL)
 792         krb5_kt_default(context, &real_keytab);
 793     else
 794         real_keytab = keytab;
 795
 796     if (ap_req->ticket.enc_part.kvno)
 797         kvno = *ap_req->ticket.enc_part.kvno;
 798     else
 799         kvno = 0;
 800
 801     ret = krb5_kt_get_entry (context,
 802                              real_keytab,
 803                              server,
 804                              kvno,
 805                              ap_req->ticket.enc_part.etype,
 806                              &entry);
 807     if(ret)
 808         goto out;
 809     ret = krb5_copy_keyblock(context, &entry.keyblock, out_key);
 810     krb5_kt_free_entry (context, &entry);
 811 out:
 812     if(keytab == NULL)
 813         krb5_kt_close(context, real_keytab);
 814
 815     return ret;
 816 }
 817
 818 /**
 819  * The core server function that verify application authentication
 820  * requests from clients.
 821  *
 822  * @param context Keberos 5 context.
 823  * @param auth_context the authentication context, can be NULL, then
 824  *        default values for the authentication context will used.
 825  * @param inbuf the (AP-REQ) authentication buffer
 826  *
 827  * @param server the server with authenticate as, if NULL the function
 828  *        will try to find any available credential in the keytab
 829  *        that will verify the reply. The function will prefer the
 830  *        server the server client specified in the AP-REQ, but if
 831  *        there is no mach, it will try all keytab entries for a
 832  *        match. This have serious performance issues for larger keytabs.
 833  *
 834  * @param inctx control the behavior of the function, if NULL, the
 835  *        default behavior is used.
 836  * @param outctx the return outctx, free with krb5_rd_req_out_ctx_free().
 837  * @return Kerberos 5 error code, see krb5_get_error_message().
 838  *
 839  * @ingroup krb5_auth
 840  */
 841
 842 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 843 krb5_rd_req_ctx(krb5_context context,
 844                 krb5_auth_context *auth_context,
 845                 const krb5_data *inbuf,
 846                 krb5_const_principal server,
 847                 krb5_rd_req_in_ctx inctx,
 848                 krb5_rd_req_out_ctx *outctx)
 849 {
 850     krb5_error_code ret;
 851     krb5_ap_req ap_req;
 852     krb5_rd_req_out_ctx o = NULL;
 853     krb5_keytab id = NULL, keytab = NULL;
 854     krb5_principal service = NULL;
 855
 856     *outctx = NULL;
 857
 858     o = calloc(1, sizeof(*o));
 859     if (o == NULL) {
 860         krb5_set_error_message(context, ENOMEM,
 861                                N_("malloc: out of memory", ""));
 862         return ENOMEM;
 863     }
 864
 865     if (*auth_context == NULL) {
 866         ret = krb5_auth_con_init(context, auth_context);
 867         if (ret)
 868             goto out;
 869     }
 870
 871     ret = krb5_decode_ap_req(context, inbuf, &ap_req);
 872     if(ret)
 873         goto out;
 874
 875     /* Save that principal that was in the request */
 876     ret = _krb5_principalname2krb5_principal(context,
 877                                              &o->server,
 878                                              ap_req.ticket.sname,
 879                                              ap_req.ticket.realm);
 880     if (ret)
 881         goto out;
 882
 883     if (ap_req.ap_options.use_session_key &&
 884         (*auth_context)->keyblock == NULL) {
 885         ret = KRB5KRB_AP_ERR_NOKEY;
 886         krb5_set_error_message(context, ret,
 887                                N_("krb5_rd_req: user to user auth "
 888                                   "without session key given", ""));
 889         goto out;
 890     }
 891
 892     if (inctx && inctx->keytab)
 893         id = inctx->keytab;
 894
 895     if((*auth_context)->keyblock){
 896         ret = krb5_copy_keyblock(context,
 897                                  (*auth_context)->keyblock,
 898                                  &o->keyblock);
 899         if (ret)
 900             goto out;
 901     } else if(inctx && inctx->keyblock){
 902         ret = krb5_copy_keyblock(context,
 903                                  inctx->keyblock,
 904                                  &o->keyblock);
 905         if (ret)
 906             goto out;
 907     } else {
 908
 909         if(id == NULL) {
 910             krb5_kt_default(context, &keytab);
 911             id = keytab;
 912         }
 913         if (id == NULL)
 914             goto out;
 915
 916         if (server == NULL) {
 917             ret = _krb5_principalname2krb5_principal(context,
 918                                                      &service,
 919                                                      ap_req.ticket.sname,
 920                                                      ap_req.ticket.realm);
 921             if (ret)
 922                 goto out;
 923             server = service;
 924         }
 925
 926         ret = get_key_from_keytab(context,
 927                                   &ap_req,
 928                                   server,
 929                                   id,
 930                                   &o->keyblock);
 931         if (ret) {
 932             /* If caller specified a server, fail. */
 933             if (service == NULL && (context->flags & KRB5_CTX_F_RD_REQ_IGNORE) == 0)
 934                 goto out;
 935             /* Otherwise, fall back to iterating over the keytab. This
 936              * have serious performace issues for larger keytab.
 937              */
 938             o->keyblock = NULL;
 939         }
 940     }
 941
 942     if (o->keyblock) {
 943         /*
 944          * We got an exact keymatch, use that.
 945          */
 946
 947         ret = krb5_verify_ap_req2(context,
 948                                   auth_context,
 949                                   &ap_req,
 950                                   server,
 951                                   o->keyblock,
 952                                   0,
 953                                   &o->ap_req_options,
 954                                   &o->ticket,
 955                                   KRB5_KU_AP_REQ_AUTH);
 956
 957         if (ret)
 958             goto out;
 959
 960     } else {
 961         /*
 962          * Interate over keytab to find a key that can decrypt the request.
 963          */
 964
 965         krb5_keytab_entry entry;
 966         krb5_kt_cursor cursor;
 967         int done = 0, kvno = 0;
 968
 969         memset(&cursor, 0, sizeof(cursor));
 970
 971         if (ap_req.ticket.enc_part.kvno)
 972             kvno = *ap_req.ticket.enc_part.kvno;
 973
 974         ret = krb5_kt_start_seq_get(context, id, &cursor);
 975         if (ret)
 976             goto out;
 977
 978         done = 0;
 979         while (!done) {
 980             krb5_principal p;
 981
 982             ret = krb5_kt_next_entry(context, id, &entry, &cursor);
 983             if (ret) {
 984                 _krb5_kt_principal_not_found(context, ret, id, o->server,
 985                                              ap_req.ticket.enc_part.etype,
 986                                              kvno);
 987                 goto out;
 988             }
 989
 990             if (entry.keyblock.keytype != ap_req.ticket.enc_part.etype) {
 991                 krb5_kt_free_entry (context, &entry);
 992                 continue;
 993             }
 994
 995             ret = krb5_verify_ap_req2(context,
 996                                       auth_context,
 997                                       &ap_req,
 998                                       server,
 999                                       &entry.keyblock,
1000                                       0,
1001                                       &o->ap_req_options,
1002                                       &o->ticket,
1003                                       KRB5_KU_AP_REQ_AUTH);
1004             if (ret) {
1005                 krb5_kt_free_entry (context, &entry);
1006                 continue;
1007             }
1008
1009             /*
1010              * Found a match, save the keyblock for PAC processing,
1011              * and update the service principal in the ticket to match
1012              * whatever is in the keytab.
1013              */
1014
1015             ret = krb5_copy_keyblock(context,
1016                                      &entry.keyblock,
1017                                      &o->keyblock);
1018             if (ret) {
1019                 krb5_kt_free_entry (context, &entry);
1020                 goto out;
1021             }
1022
1023             ret = krb5_copy_principal(context, entry.principal, &p);
1024             if (ret) {
1025                 krb5_kt_free_entry (context, &entry);
1026                 goto out;
1027             }
1028             krb5_free_principal(context, o->ticket->server);
1029             o->ticket->server = p;
1030
1031             krb5_kt_free_entry (context, &entry);
1032
1033             done = 1;
1034         }
1035         krb5_kt_end_seq_get (context, id, &cursor);
1036     }
1037
1038     /* If there is a PAC, verify its server signature */
1039     if (inctx == NULL || inctx->check_pac) {
1040         krb5_pac pac;
1041         krb5_data data;
1042
1043         ret = krb5_ticket_get_authorization_data_type(context,
1044                                                       o->ticket,
1045                                                       KRB5_AUTHDATA_WIN2K_PAC,
1046                                                       &data);
1047         if (ret == 0) {
1048             ret = krb5_pac_parse(context, data.data, data.length, &pac);
1049             krb5_data_free(&data);
1050             if (ret)
1051                 goto out;
1052
1053             ret = krb5_pac_verify(context,
1054                                   pac,
1055                                   o->ticket->ticket.authtime,
1056                                   o->ticket->client,
1057                                   o->keyblock,
1058                                   NULL);
1059             krb5_pac_free(context, pac);
1060             if (ret)
1061                 goto out;
1062         } else
1063           ret = 0;
1064     }
1065 out:
1066
1067     if (ret || outctx == NULL) {
1068         krb5_rd_req_out_ctx_free(context, o);
1069     } else
1070         *outctx = o;
1071
1072     free_AP_REQ(&ap_req);
1073
1074     if (service)
1075         krb5_free_principal(context, service);
1076
1077     if (keytab)
1078         krb5_kt_close(context, keytab);
1079
1080     return ret;
1081 }