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, n;
 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     for (n = 0; n < num_realms; n++)
 165         free(realms[n]);
 166     free(realms);
 167     return ret;
 168 }
 169
 170 static krb5_error_code
 171 find_etypelist(krb5_context context,
 172                krb5_auth_context auth_context,
 173                EtypeList *etypes)
 174 {
 175     krb5_error_code ret;
 176     krb5_authdata *ad;
 177     krb5_authdata adIfRelevant;
 178     unsigned i;
 179
 180     memset(&adIfRelevant, 0, sizeof(adIfRelevant));
 181
 182     etypes->len = 0;
 183     etypes->val = NULL;
 184
 185     ad = auth_context->authenticator->authorization_data;
 186     if (ad == NULL)
 187         return 0;
 188
 189     for (i = 0; i < ad->len; i++) {
 190         if (ad->val[i].ad_type == KRB5_AUTHDATA_IF_RELEVANT) {
 191             ret = decode_AD_IF_RELEVANT(ad->val[i].ad_data.data,
 192                                         ad->val[i].ad_data.length,
 193                                         &adIfRelevant,
 194                                         NULL);
 195             if (ret)
 196                 return ret;
 197
 198             if (adIfRelevant.len == 1 &&
 199                 adIfRelevant.val[0].ad_type ==
 200                         KRB5_AUTHDATA_GSS_API_ETYPE_NEGOTIATION) {
 201                 break;
 202             }
 203             free_AD_IF_RELEVANT(&adIfRelevant);
 204             adIfRelevant.len = 0;
 205         }
 206     }
 207
 208     if (adIfRelevant.len == 0)
 209         return 0;
 210
 211     ret = decode_EtypeList(adIfRelevant.val[0].ad_data.data,
 212                            adIfRelevant.val[0].ad_data.length,
 213                            etypes,
 214                            NULL);
 215     if (ret)
 216         krb5_clear_error_message(context);
 217
 218     free_AD_IF_RELEVANT(&adIfRelevant);
 219
 220     return ret;
 221 }
 222
 223 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 224 krb5_decrypt_ticket(krb5_context context,
 225                     Ticket *ticket,
 226                     krb5_keyblock *key,
 227                     EncTicketPart *out,
 228                     krb5_flags flags)
 229 {
 230     EncTicketPart t;
 231     krb5_error_code ret;
 232     ret = decrypt_tkt_enc_part (context, key, &ticket->enc_part, &t);
 233     if (ret)
 234         return ret;
 235
 236     {
 237         krb5_timestamp now;
 238         time_t start = t.authtime;
 239
 240         krb5_timeofday (context, &now);
 241         if(t.starttime)
 242             start = *t.starttime;
 243         if(start - now > context->max_skew
 244            || (t.flags.invalid
 245                && !(flags & KRB5_VERIFY_AP_REQ_IGNORE_INVALID))) {
 246             free_EncTicketPart(&t);
 247             krb5_clear_error_message (context);
 248             return KRB5KRB_AP_ERR_TKT_NYV;
 249         }
 250         if(now - t.endtime > context->max_skew) {
 251             free_EncTicketPart(&t);
 252             krb5_clear_error_message (context);
 253             return KRB5KRB_AP_ERR_TKT_EXPIRED;
 254         }
 255
 256         if(!t.flags.transited_policy_checked) {
 257             ret = check_transited(context, ticket, &t);
 258             if(ret) {
 259                 free_EncTicketPart(&t);
 260                 return ret;
 261             }
 262         }
 263     }
 264
 265     if(out)
 266         *out = t;
 267     else
 268         free_EncTicketPart(&t);
 269     return 0;
 270 }
 271
 272 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 273 krb5_verify_authenticator_checksum(krb5_context context,
 274                                    krb5_auth_context ac,
 275                                    void *data,
 276                                    size_t len)
 277 {
 278     krb5_error_code ret;
 279     krb5_keyblock *key;
 280     krb5_authenticator authenticator;
 281     krb5_crypto crypto;
 282
 283     ret = krb5_auth_con_getauthenticator (context,
 284                                       ac,
 285                                       &authenticator);
 286     if(ret)
 287         return ret;
 288     if(authenticator->cksum == NULL) {
 289         krb5_free_authenticator(context, &authenticator);
 290         return -17;
 291     }
 292     ret = krb5_auth_con_getkey(context, ac, &key);
 293     if(ret) {
 294         krb5_free_authenticator(context, &authenticator);
 295         return ret;
 296     }
 297     ret = krb5_crypto_init(context, key, 0, &crypto);
 298     if(ret)
 299         goto out;
 300     ret = krb5_verify_checksum (context,
 301                                 crypto,
 302                                 KRB5_KU_AP_REQ_AUTH_CKSUM,
 303                                 data,
 304                                 len,
 305                                 authenticator->cksum);
 306     krb5_crypto_destroy(context, crypto);
 307 out:
 308     krb5_free_authenticator(context, &authenticator);
 309     krb5_free_keyblock(context, key);
 310     return ret;
 311 }
 312
 313
 314 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 315 krb5_verify_ap_req(krb5_context context,
 316                    krb5_auth_context *auth_context,
 317                    krb5_ap_req *ap_req,
 318                    krb5_const_principal server,
 319                    krb5_keyblock *keyblock,
 320                    krb5_flags flags,
 321                    krb5_flags *ap_req_options,
 322                    krb5_ticket **ticket)
 323 {
 324     return krb5_verify_ap_req2 (context,
 325                                 auth_context,
 326                                 ap_req,
 327                                 server,
 328                                 keyblock,
 329                                 flags,
 330                                 ap_req_options,
 331                                 ticket,
 332                                 KRB5_KU_AP_REQ_AUTH);
 333 }
 334
 335 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 336 krb5_verify_ap_req2(krb5_context context,
 337                     krb5_auth_context *auth_context,
 338                     krb5_ap_req *ap_req,
 339                     krb5_const_principal server,
 340                     krb5_keyblock *keyblock,
 341                     krb5_flags flags,
 342                     krb5_flags *ap_req_options,
 343                     krb5_ticket **ticket,
 344                     krb5_key_usage usage)
 345 {
 346     krb5_ticket *t;
 347     krb5_auth_context ac;
 348     krb5_error_code ret;
 349     EtypeList etypes;
 350
 351     if (ticket)
 352         *ticket = NULL;
 353
 354     if (auth_context && *auth_context) {
 355         ac = *auth_context;
 356     } else {
 357         ret = krb5_auth_con_init (context, &ac);
 358         if (ret)
 359             return ret;
 360     }
 361
 362     t = calloc(1, sizeof(*t));
 363     if (t == NULL) {
 364         ret = ENOMEM;
 365         krb5_clear_error_message (context);
 366         goto out;
 367     }
 368
 369     if (ap_req->ap_options.use_session_key && ac->keyblock){
 370         ret = krb5_decrypt_ticket(context, &ap_req->ticket,
 371                                   ac->keyblock,
 372                                   &t->ticket,
 373                                   flags);
 374         krb5_free_keyblock(context, ac->keyblock);
 375         ac->keyblock = NULL;
 376     }else
 377         ret = krb5_decrypt_ticket(context, &ap_req->ticket,
 378                                   keyblock,
 379                                   &t->ticket,
 380                                   flags);
 381
 382     if(ret)
 383         goto out;
 384
 385     ret = _krb5_principalname2krb5_principal(context,
 386                                              &t->server,
 387                                              ap_req->ticket.sname,
 388                                              ap_req->ticket.realm);
 389     if (ret) goto out;
 390     ret = _krb5_principalname2krb5_principal(context,
 391                                              &t->client,
 392                                              t->ticket.cname,
 393                                              t->ticket.crealm);
 394     if (ret) goto out;
 395
 396     ret = decrypt_authenticator (context,
 397                                  &t->ticket.key,
 398                                  &ap_req->authenticator,
 399                                  ac->authenticator,
 400                                  usage);
 401     if (ret)
 402         goto out;
 403
 404     {
 405         krb5_principal p1, p2;
 406         krb5_boolean res;
 407
 408         _krb5_principalname2krb5_principal(context,
 409                                            &p1,
 410                                            ac->authenticator->cname,
 411                                            ac->authenticator->crealm);
 412         _krb5_principalname2krb5_principal(context,
 413                                            &p2,
 414                                            t->ticket.cname,
 415                                            t->ticket.crealm);
 416         res = krb5_principal_compare (context, p1, p2);
 417         krb5_free_principal (context, p1);
 418         krb5_free_principal (context, p2);
 419         if (!res) {
 420             ret = KRB5KRB_AP_ERR_BADMATCH;
 421             krb5_clear_error_message (context);
 422             goto out;
 423         }
 424     }
 425
 426     /* check addresses */
 427
 428     if (t->ticket.caddr
 429         && ac->remote_address
 430         && !krb5_address_search (context,
 431                                  ac->remote_address,
 432                                  t->ticket.caddr)) {
 433         ret = KRB5KRB_AP_ERR_BADADDR;
 434         krb5_clear_error_message (context);
 435         goto out;
 436     }
 437
 438     /* check timestamp in authenticator */
 439     {
 440         krb5_timestamp now;
 441
 442         krb5_timeofday (context, &now);
 443
 444         if (abs(ac->authenticator->ctime - now) > context->max_skew) {
 445             ret = KRB5KRB_AP_ERR_SKEW;
 446             krb5_clear_error_message (context);
 447             goto out;
 448         }
 449     }
 450
 451     if (ac->authenticator->seq_number)
 452         krb5_auth_con_setremoteseqnumber(context, ac,
 453                                          *ac->authenticator->seq_number);
 454
 455     /* XXX - Xor sequence numbers */
 456
 457     if (ac->authenticator->subkey) {
 458         ret = krb5_auth_con_setremotesubkey(context, ac,
 459                                             ac->authenticator->subkey);
 460         if (ret)
 461             goto out;
 462     }
 463
 464     ret = find_etypelist(context, ac, &etypes);
 465     if (ret)
 466         goto out;
 467
 468     ac->keytype = ETYPE_NULL;
 469
 470     if (etypes.val) {
 471         size_t i;
 472
 473         for (i = 0; i < etypes.len; i++) {
 474             if (krb5_enctype_valid(context, etypes.val[i]) == 0) {
 475                 ac->keytype = etypes.val[i];
 476                 break;
 477             }
 478         }
 479     }
 480
 481     /* save key */
 482     ret = krb5_copy_keyblock(context, &t->ticket.key, &ac->keyblock);
 483     if (ret) goto out;
 484
 485     if (ap_req_options) {
 486         *ap_req_options = 0;
 487         if (ac->keytype != ETYPE_NULL)
 488             *ap_req_options |= AP_OPTS_USE_SUBKEY;
 489         if (ap_req->ap_options.use_session_key)
 490             *ap_req_options |= AP_OPTS_USE_SESSION_KEY;
 491         if (ap_req->ap_options.mutual_required)
 492             *ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
 493     }
 494
 495     if(ticket)
 496         *ticket = t;
 497     else
 498         krb5_free_ticket (context, t);
 499     if (auth_context) {
 500         if (*auth_context == NULL)
 501             *auth_context = ac;
 502     } else
 503         krb5_auth_con_free (context, ac);
 504     free_EtypeList(&etypes);
 505     return 0;
 506  out:
 507     if (t)
 508         krb5_free_ticket (context, t);
 509     if (auth_context == NULL || *auth_context == NULL)
 510         krb5_auth_con_free (context, ac);
 511     return ret;
 512 }
 513
 514 /*
 515  *
 516  */
 517
 518 struct krb5_rd_req_in_ctx_data {
 519     krb5_keytab keytab;
 520     krb5_keyblock *keyblock;
 521     krb5_boolean check_pac;
 522 };
 523
 524 struct krb5_rd_req_out_ctx_data {
 525     krb5_keyblock *keyblock;
 526     krb5_flags ap_req_options;
 527     krb5_ticket *ticket;
 528     krb5_principal server;
 529 };
 530
 531 /**
 532  * Allocate a krb5_rd_req_in_ctx as an input parameter to
 533  * krb5_rd_req_ctx(). The caller should free the context with
 534  * krb5_rd_req_in_ctx_free() when done with the context.
 535  *
 536  * @param context Keberos 5 context.
 537  * @param ctx in ctx to krb5_rd_req_ctx().
 538  *
 539  * @return Kerberos 5 error code, see krb5_get_error_message().
 540  *
 541  * @ingroup krb5_auth
 542  */
 543
 544 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 545 krb5_rd_req_in_ctx_alloc(krb5_context context, krb5_rd_req_in_ctx *ctx)
 546 {
 547     *ctx = calloc(1, sizeof(**ctx));
 548     if (*ctx == NULL) {
 549         krb5_set_error_message(context, ENOMEM,
 550                                N_("malloc: out of memory", ""));
 551         return ENOMEM;
 552     }
 553     (*ctx)->check_pac = (context->flags & KRB5_CTX_F_CHECK_PAC) ? 1 : 0;
 554     return 0;
 555 }
 556
 557 /**
 558  * Set the keytab that krb5_rd_req_ctx() will use.
 559  *
 560  * @param context Keberos 5 context.
 561  * @param in in ctx to krb5_rd_req_ctx().
 562  * @param keytab keytab that krb5_rd_req_ctx() will use, only copy the
 563  *        pointer, so the caller must free they keytab after
 564  *        krb5_rd_req_in_ctx_free() is called.
 565  *
 566  * @return Kerberos 5 error code, see krb5_get_error_message().
 567  *
 568  * @ingroup krb5_auth
 569  */
 570
 571 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 572 krb5_rd_req_in_set_keytab(krb5_context context,
 573                           krb5_rd_req_in_ctx in,
 574                           krb5_keytab keytab)
 575 {
 576     in->keytab = keytab;
 577     return 0;
 578 }
 579
 580 /**
 581  * Set if krb5_rq_red() is going to check the Windows PAC or not
 582  *
 583  * @param context Keberos 5 context.
 584  * @param in krb5_rd_req_in_ctx to check the option on.
 585  * @param flag flag to select if to check the pac (TRUE) or not (FALSE).
 586  *
 587  * @return Kerberos 5 error code, see krb5_get_error_message().
 588  *
 589  * @ingroup krb5_auth
 590  */
 591
 592 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 593 krb5_rd_req_in_set_pac_check(krb5_context context,
 594                              krb5_rd_req_in_ctx in,
 595                              krb5_boolean flag)
 596 {
 597     in->check_pac = flag;
 598     return 0;
 599 }
 600
 601
 602 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 603 krb5_rd_req_in_set_keyblock(krb5_context context,
 604                             krb5_rd_req_in_ctx in,
 605                             krb5_keyblock *keyblock)
 606 {
 607     in->keyblock = keyblock; /* XXX should make copy */
 608     return 0;
 609 }
 610
 611 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 612 krb5_rd_req_out_get_ap_req_options(krb5_context context,
 613                                    krb5_rd_req_out_ctx out,
 614                                    krb5_flags *ap_req_options)
 615 {
 616     *ap_req_options = out->ap_req_options;
 617     return 0;
 618 }
 619
 620 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 621 krb5_rd_req_out_get_ticket(krb5_context context,
 622                             krb5_rd_req_out_ctx out,
 623                             krb5_ticket **ticket)
 624 {
 625     return krb5_copy_ticket(context, out->ticket, ticket);
 626 }
 627
 628 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 629 krb5_rd_req_out_get_keyblock(krb5_context context,
 630                             krb5_rd_req_out_ctx out,
 631                             krb5_keyblock **keyblock)
 632 {
 633     return krb5_copy_keyblock(context, out->keyblock, keyblock);
 634 }
 635
 636 /**
 637  * Get the principal that was used in the request from the
 638  * client. Might not match whats in the ticket if krb5_rd_req_ctx()
 639  * searched in the keytab for a matching key.
 640  *
 641  * @param context a Kerberos 5 context.
 642  * @param out a krb5_rd_req_out_ctx from krb5_rd_req_ctx().
 643  * @param principal return principal, free with krb5_free_principal().
 644  *
 645  * @ingroup krb5_auth
 646  */
 647
 648 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 649 krb5_rd_req_out_get_server(krb5_context context,
 650                             krb5_rd_req_out_ctx out,
 651                             krb5_principal *principal)
 652 {
 653     return krb5_copy_principal(context, out->server, principal);
 654 }
 655
 656 KRB5_LIB_FUNCTION void KRB5_LIB_CALL
 657 krb5_rd_req_in_ctx_free(krb5_context context, krb5_rd_req_in_ctx ctx)
 658 {
 659     free(ctx);
 660 }
 661
 662 /**
 663  * Free the krb5_rd_req_out_ctx.
 664  *
 665  * @param context Keberos 5 context.
 666  * @param ctx krb5_rd_req_out_ctx context to free.
 667  *
 668  * @ingroup krb5_auth
 669  */
 670
 671 KRB5_LIB_FUNCTION void KRB5_LIB_CALL
 672 krb5_rd_req_out_ctx_free(krb5_context context, krb5_rd_req_out_ctx ctx)
 673 {
 674     if (ctx->ticket)
 675         krb5_free_ticket(context, ctx->ticket);
 676     if (ctx->keyblock)
 677         krb5_free_keyblock(context, ctx->keyblock);
 678     if (ctx->server)
 679         krb5_free_principal(context, ctx->server);
 680     free(ctx);
 681 }
 682
 683 /*
 684  *
 685  */
 686
 687 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 688 krb5_rd_req(krb5_context context,
 689             krb5_auth_context *auth_context,
 690             const krb5_data *inbuf,
 691             krb5_const_principal server,
 692             krb5_keytab keytab,
 693             krb5_flags *ap_req_options,
 694             krb5_ticket **ticket)
 695 {
 696     krb5_error_code ret;
 697     krb5_rd_req_in_ctx in;
 698     krb5_rd_req_out_ctx out;
 699
 700     ret = krb5_rd_req_in_ctx_alloc(context, &in);
 701     if (ret)
 702         return ret;
 703
 704     ret = krb5_rd_req_in_set_keytab(context, in, keytab);
 705     if (ret) {
 706         krb5_rd_req_in_ctx_free(context, in);
 707         return ret;
 708     }
 709
 710     ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out);
 711     krb5_rd_req_in_ctx_free(context, in);
 712     if (ret)
 713         return ret;
 714
 715     if (ap_req_options)
 716         *ap_req_options = out->ap_req_options;
 717     if (ticket) {
 718         ret = krb5_copy_ticket(context, out->ticket, ticket);
 719         if (ret)
 720             goto out;
 721     }
 722
 723 out:
 724     krb5_rd_req_out_ctx_free(context, out);
 725     return ret;
 726 }
 727
 728 /*
 729  *
 730  */
 731
 732 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 733 krb5_rd_req_with_keyblock(krb5_context context,
 734                           krb5_auth_context *auth_context,
 735                           const krb5_data *inbuf,
 736                           krb5_const_principal server,
 737                           krb5_keyblock *keyblock,
 738                           krb5_flags *ap_req_options,
 739                           krb5_ticket **ticket)
 740 {
 741     krb5_error_code ret;
 742     krb5_rd_req_in_ctx in;
 743     krb5_rd_req_out_ctx out;
 744
 745     ret = krb5_rd_req_in_ctx_alloc(context, &in);
 746     if (ret)
 747         return ret;
 748
 749     ret = krb5_rd_req_in_set_keyblock(context, in, keyblock);
 750     if (ret) {
 751         krb5_rd_req_in_ctx_free(context, in);
 752         return ret;
 753     }
 754
 755     ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out);
 756     krb5_rd_req_in_ctx_free(context, in);
 757     if (ret)
 758         return ret;
 759
 760     if (ap_req_options)
 761         *ap_req_options = out->ap_req_options;
 762     if (ticket) {
 763         ret = krb5_copy_ticket(context, out->ticket, ticket);
 764         if (ret)
 765             goto out;
 766     }
 767
 768 out:
 769     krb5_rd_req_out_ctx_free(context, out);
 770     return ret;
 771 }
 772
 773 /*
 774  *
 775  */
 776
 777 static krb5_error_code
 778 get_key_from_keytab(krb5_context context,
 779                     krb5_ap_req *ap_req,
 780                     krb5_const_principal server,
 781                     krb5_keytab keytab,
 782                     krb5_keyblock **out_key)
 783 {
 784     krb5_keytab_entry entry;
 785     krb5_error_code ret;
 786     int kvno;
 787     krb5_keytab real_keytab;
 788
 789     if(keytab == NULL)
 790         krb5_kt_default(context, &real_keytab);
 791     else
 792         real_keytab = keytab;
 793
 794     if (ap_req->ticket.enc_part.kvno)
 795         kvno = *ap_req->ticket.enc_part.kvno;
 796     else
 797         kvno = 0;
 798
 799     ret = krb5_kt_get_entry (context,
 800                              real_keytab,
 801                              server,
 802                              kvno,
 803                              ap_req->ticket.enc_part.etype,
 804                              &entry);
 805     if(ret)
 806         goto out;
 807     ret = krb5_copy_keyblock(context, &entry.keyblock, out_key);
 808     krb5_kt_free_entry (context, &entry);
 809 out:
 810     if(keytab == NULL)
 811         krb5_kt_close(context, real_keytab);
 812
 813     return ret;
 814 }
 815
 816 /**
 817  * The core server function that verify application authentication
 818  * requests from clients.
 819  *
 820  * @param context Keberos 5 context.
 821  * @param auth_context the authentication context, can be NULL, then
 822  *        default values for the authentication context will used.
 823  * @param inbuf the (AP-REQ) authentication buffer
 824  *
 825  * @param server the server with authenticate as, if NULL the function
 826  *        will try to find any available credential in the keytab
 827  *        that will verify the reply. The function will prefer the
 828  *        server the server client specified in the AP-REQ, but if
 829  *        there is no mach, it will try all keytab entries for a
 830  *        match. This have serious performance issues for larger keytabs.
 831  *
 832  * @param inctx control the behavior of the function, if NULL, the
 833  *        default behavior is used.
 834  * @param outctx the return outctx, free with krb5_rd_req_out_ctx_free().
 835  * @return Kerberos 5 error code, see krb5_get_error_message().
 836  *
 837  * @ingroup krb5_auth
 838  */
 839
 840 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
 841 krb5_rd_req_ctx(krb5_context context,
 842                 krb5_auth_context *auth_context,
 843                 const krb5_data *inbuf,
 844                 krb5_const_principal server,
 845                 krb5_rd_req_in_ctx inctx,
 846                 krb5_rd_req_out_ctx *outctx)
 847 {
 848     krb5_error_code ret;
 849     krb5_ap_req ap_req;
 850     krb5_rd_req_out_ctx o = NULL;
 851     krb5_keytab id = NULL, keytab = NULL;
 852     krb5_principal service = NULL;
 853
 854     *outctx = NULL;
 855
 856     o = calloc(1, sizeof(*o));
 857     if (o == NULL) {
 858         krb5_set_error_message(context, ENOMEM,
 859                                N_("malloc: out of memory", ""));
 860         return ENOMEM;
 861     }
 862
 863     if (*auth_context == NULL) {
 864         ret = krb5_auth_con_init(context, auth_context);
 865         if (ret)
 866             goto out;
 867     }
 868
 869     ret = krb5_decode_ap_req(context, inbuf, &ap_req);
 870     if(ret)
 871         goto out;
 872
 873     /* Save that principal that was in the request */
 874     ret = _krb5_principalname2krb5_principal(context,
 875                                              &o->server,
 876                                              ap_req.ticket.sname,
 877                                              ap_req.ticket.realm);
 878     if (ret)
 879         goto out;
 880
 881     if (ap_req.ap_options.use_session_key &&
 882         (*auth_context)->keyblock == NULL) {
 883         ret = KRB5KRB_AP_ERR_NOKEY;
 884         krb5_set_error_message(context, ret,
 885                                N_("krb5_rd_req: user to user auth "
 886                                   "without session key given", ""));
 887         goto out;
 888     }
 889
 890     if (inctx && inctx->keytab)
 891         id = inctx->keytab;
 892
 893     if((*auth_context)->keyblock){
 894         ret = krb5_copy_keyblock(context,
 895                                  (*auth_context)->keyblock,
 896                                  &o->keyblock);
 897         if (ret)
 898             goto out;
 899     } else if(inctx && inctx->keyblock){
 900         ret = krb5_copy_keyblock(context,
 901                                  inctx->keyblock,
 902                                  &o->keyblock);
 903         if (ret)
 904             goto out;
 905     } else {
 906
 907         if(id == NULL) {
 908             krb5_kt_default(context, &keytab);
 909             id = keytab;
 910         }
 911         if (id == NULL)
 912             goto out;
 913
 914         if (server == NULL) {
 915             ret = _krb5_principalname2krb5_principal(context,
 916                                                      &service,
 917                                                      ap_req.ticket.sname,
 918                                                      ap_req.ticket.realm);
 919             if (ret)
 920                 goto out;
 921             server = service;
 922         }
 923
 924         ret = get_key_from_keytab(context,
 925                                   &ap_req,
 926                                   server,
 927                                   id,
 928                                   &o->keyblock);
 929         if (ret) {
 930             /* If caller specified a server, fail. */
 931             if (service == NULL && (context->flags & KRB5_CTX_F_RD_REQ_IGNORE) == 0)
 932                 goto out;
 933             /* Otherwise, fall back to iterating over the keytab. This
 934              * have serious performace issues for larger keytab.
 935              */
 936             o->keyblock = NULL;
 937         }
 938     }
 939
 940     if (o->keyblock) {
 941         /*
 942          * We got an exact keymatch, use that.
 943          */
 944
 945         ret = krb5_verify_ap_req2(context,
 946                                   auth_context,
 947                                   &ap_req,
 948                                   server,
 949                                   o->keyblock,
 950                                   0,
 951                                   &o->ap_req_options,
 952                                   &o->ticket,
 953                                   KRB5_KU_AP_REQ_AUTH);
 954
 955         if (ret)
 956             goto out;
 957
 958     } else {
 959         /*
 960          * Interate over keytab to find a key that can decrypt the request.
 961          */
 962
 963         krb5_keytab_entry entry;
 964         krb5_kt_cursor cursor;
 965         int done = 0, kvno = 0;
 966
 967         memset(&cursor, 0, sizeof(cursor));
 968
 969         if (ap_req.ticket.enc_part.kvno)
 970             kvno = *ap_req.ticket.enc_part.kvno;
 971
 972         ret = krb5_kt_start_seq_get(context, id, &cursor);
 973         if (ret)
 974             goto out;
 975
 976         done = 0;
 977         while (!done) {
 978             krb5_principal p;
 979
 980             ret = krb5_kt_next_entry(context, id, &entry, &cursor);
 981             if (ret) {
 982                 _krb5_kt_principal_not_found(context, ret, id, o->server,
 983                                              ap_req.ticket.enc_part.etype,
 984                                              kvno);
 985                 goto out;
 986             }
 987
 988             if (entry.keyblock.keytype != ap_req.ticket.enc_part.etype) {
 989                 krb5_kt_free_entry (context, &entry);
 990                 continue;
 991             }
 992
 993             ret = krb5_verify_ap_req2(context,
 994                                       auth_context,
 995                                       &ap_req,
 996                                       server,
 997                                       &entry.keyblock,
 998                                       0,
 999                                       &o->ap_req_options,
1000                                       &o->ticket,
1001                                       KRB5_KU_AP_REQ_AUTH);
1002             if (ret) {
1003                 krb5_kt_free_entry (context, &entry);
1004                 continue;
1005             }
1006
1007             /*
1008              * Found a match, save the keyblock for PAC processing,
1009              * and update the service principal in the ticket to match
1010              * whatever is in the keytab.
1011              */
1012
1013             ret = krb5_copy_keyblock(context,
1014                                      &entry.keyblock,
1015                                      &o->keyblock);
1016             if (ret) {
1017                 krb5_kt_free_entry (context, &entry);
1018                 goto out;
1019             }
1020
1021             ret = krb5_copy_principal(context, entry.principal, &p);
1022             if (ret) {
1023                 krb5_kt_free_entry (context, &entry);
1024                 goto out;
1025             }
1026             krb5_free_principal(context, o->ticket->server);
1027             o->ticket->server = p;
1028
1029             krb5_kt_free_entry (context, &entry);
1030
1031             done = 1;
1032         }
1033         krb5_kt_end_seq_get (context, id, &cursor);
1034     }
1035
1036     /* If there is a PAC, verify its server signature */
1037     if (inctx == NULL || inctx->check_pac) {
1038         krb5_pac pac;
1039         krb5_data data;
1040
1041         ret = krb5_ticket_get_authorization_data_type(context,
1042                                                       o->ticket,
1043                                                       KRB5_AUTHDATA_WIN2K_PAC,
1044                                                       &data);
1045         if (ret == 0) {
1046             ret = krb5_pac_parse(context, data.data, data.length, &pac);
1047             krb5_data_free(&data);
1048             if (ret)
1049                 goto out;
1050
1051             ret = krb5_pac_verify(context,
1052                                   pac,
1053                                   o->ticket->ticket.authtime,
1054                                   o->ticket->client,
1055                                   o->keyblock,
1056                                   NULL);
1057             krb5_pac_free(context, pac);
1058             if (ret)
1059                 goto out;
1060         } else
1061           ret = 0;
1062     }
1063 out:
1064
1065     if (ret || outctx == NULL) {
1066         krb5_rd_req_out_ctx_free(context, o);
1067     } else
1068         *outctx = o;
1069
1070     free_AP_REQ(&ap_req);
1071
1072     if (service)
1073         krb5_free_principal(context, service);
1074
1075     if (keytab)
1076         krb5_kt_close(context, keytab);
1077
1078     return ret;
1079 }