src/kdc/do_as_req.c

   1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
   2 /* kdc/do_as_req.c */
   3 /*
   4  * Portions Copyright (C) 2007 Apple Inc.
   5  * Copyright 1990, 1991, 2007, 2008, 2009, 2013, 2014 by the
   6  * Massachusetts Institute of Technology.  All Rights Reserved.
   7  *
   8  * Export of this software from the United States of America may
   9  *   require a specific license from the United States Government.
  10  *   It is the responsibility of any person or organization contemplating
  11  *   export to obtain such a license before exporting.
  12  *
  13  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
  14  * distribute this software and its documentation for any purpose and
  15  * without fee is hereby granted, provided that the above copyright
  16  * notice appear in all copies and that both that copyright notice and
  17  * this permission notice appear in supporting documentation, and that
  18  * the name of M.I.T. not be used in advertising or publicity pertaining
  19  * to distribution of the software without specific, written prior
  20  * permission.  Furthermore if you modify this software you must label
  21  * your software as modified software and not distribute it in such a
  22  * fashion that it might be confused with the original M.I.T. software.
  23  * M.I.T. makes no representations about the suitability of
  24  * this software for any purpose.  It is provided "as is" without express
  25  * or implied warranty.
  26  *
  27  *
  28  * KDC Routines to deal with AS_REQ's
  29  */
  30 /*
  31  * Copyright (c) 2006-2008, Novell, Inc.
  32  * All rights reserved.
  33  *
  34  * Redistribution and use in source and binary forms, with or without
  35  * modification, are permitted provided that the following conditions are met:
  36  *
  37  *   * Redistributions of source code must retain the above copyright notice,
  38  *       this list of conditions and the following disclaimer.
  39  *   * Redistributions in binary form must reproduce the above copyright
  40  *       notice, this list of conditions and the following disclaimer in the
  41  *       documentation and/or other materials provided with the distribution.
  42  *   * The copyright holder's name is not used to endorse or promote products
  43  *       derived from this software without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  46  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  49  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  50  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  51  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  52  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  53  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  54  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  55  * POSSIBILITY OF SUCH DAMAGE.
  56  */
  57
  58 #include "k5-int.h"
  59 #include "com_err.h"
  60
  61 #include <syslog.h>
  62 #ifdef HAVE_NETINET_IN_H
  63 #include <sys/types.h>
  64 #include <netinet/in.h>
  65 #ifndef hpux
  66 #include <arpa/inet.h>
  67 #endif  /* hpux */
  68 #endif /* HAVE_NETINET_IN_H */
  69
  70 #include "kdc_util.h"
  71 #include "kdc_audit.h"
  72 #include "policy.h"
  73 #include <kadm5/admin.h>
  74 #include "adm_proto.h"
  75 #include "extern.h"
  76
  77 static krb5_error_code
  78 prepare_error_as(struct kdc_request_state *, krb5_kdc_req *, krb5_db_entry *,
  79                  int, krb5_pa_data **, krb5_boolean, krb5_principal,
  80                  krb5_data **, const char *);
  81
  82 /* Determine the key-expiration value according to RFC 4120 section 5.4.2. */
  83 static krb5_timestamp
  84 get_key_exp(krb5_db_entry *entry)
  85 {
  86     if (entry->expiration == 0)
  87         return entry->pw_expiration;
  88     if (entry->pw_expiration == 0)
  89         return entry->expiration;
  90     return ts_min(entry->expiration, entry->pw_expiration);
  91 }
  92
  93 /*
  94  * Find the key in client for the most preferred enctype in req_enctypes.  Fill
  95  * in *kb_out with the decrypted keyblock (which the caller must free) and set
  96  * *kd_out to an alias to that key data entry.  Set *kd_out to NULL and leave
  97  * *kb_out zeroed if no key is found for any of the requested enctypes.
  98  * kb_out->enctype may differ from the enctype of *kd_out for DES enctypes; in
  99  * this case, kb_out->enctype is the requested enctype used to match the key
 100  * data entry.
 101  */
 102 static krb5_error_code
 103 select_client_key(krb5_context context, krb5_db_entry *client,
 104                   krb5_enctype *req_enctypes, int n_req_enctypes,
 105                   krb5_keyblock *kb_out, krb5_key_data **kd_out)
 106 {
 107     krb5_error_code ret;
 108     krb5_key_data *kd;
 109     krb5_enctype etype;
 110     int i;
 111
 112     memset(kb_out, 0, sizeof(*kb_out));
 113     *kd_out = NULL;
 114
 115     for (i = 0; i < n_req_enctypes; i++) {
 116         etype = req_enctypes[i];
 117         if (!krb5_c_valid_enctype(etype))
 118             continue;
 119         if (krb5_dbe_find_enctype(context, client, etype, -1, 0, &kd) == 0) {
 120             /* Decrypt the client key data and set its enctype to the request
 121              * enctype (which may differ from the key data enctype for DES). */
 122             ret = krb5_dbe_decrypt_key_data(context, NULL, kd, kb_out, NULL);
 123             if (ret)
 124                 return ret;
 125             kb_out->enctype = etype;
 126             *kd_out = kd;
 127             return 0;
 128         }
 129     }
 130     return 0;
 131 }
 132
 133 struct as_req_state {
 134     loop_respond_fn respond;
 135     void *arg;
 136
 137     krb5_principal_data client_princ;
 138     krb5_enc_tkt_part enc_tkt_reply;
 139     krb5_enc_kdc_rep_part reply_encpart;
 140     krb5_ticket ticket_reply;
 141     krb5_keyblock server_keyblock;
 142     krb5_keyblock client_keyblock;
 143     krb5_db_entry *client;
 144     krb5_db_entry *server;
 145     krb5_db_entry *local_tgt;
 146     krb5_db_entry *local_tgt_storage;
 147     krb5_key_data *client_key;
 148     krb5_kdc_req *request;
 149     struct krb5_kdcpreauth_rock_st rock;
 150     const char *status;
 151     krb5_pa_data **e_data;
 152     krb5_boolean typed_e_data;
 153     krb5_kdc_rep reply;
 154     krb5_timestamp kdc_time;
 155     krb5_timestamp authtime;
 156     krb5_keyblock session_key;
 157     unsigned int c_flags;
 158     krb5_data *req_pkt;
 159     krb5_data *inner_body;
 160     struct kdc_request_state *rstate;
 161     char *sname, *cname;
 162     void *pa_context;
 163     const krb5_fulladdr *local_addr;
 164     const krb5_fulladdr *remote_addr;
 165     krb5_data **auth_indicators;
 166
 167     krb5_error_code preauth_err;
 168
 169     kdc_realm_t *active_realm;
 170     krb5_audit_state *au_state;
 171 };
 172
 173 static void
 174 finish_process_as_req(struct as_req_state *state, krb5_error_code errcode)
 175 {
 176     krb5_key_data *server_key;
 177     krb5_keyblock *as_encrypting_key = NULL;
 178     krb5_data *response = NULL;
 179     const char *emsg = 0;
 180     int did_log = 0;
 181     loop_respond_fn oldrespond;
 182     void *oldarg;
 183     kdc_realm_t *kdc_active_realm = state->active_realm;
 184     krb5_audit_state *au_state = state->au_state;
 185
 186     assert(state);
 187     oldrespond = state->respond;
 188     oldarg = state->arg;
 189
 190     if (errcode)
 191         goto egress;
 192
 193     au_state->stage = ENCR_REP;
 194
 195     if ((errcode = validate_forwardable(state->request, *state->client,
 196                                         *state->server, state->kdc_time,
 197                                         &state->status))) {
 198         errcode += ERROR_TABLE_BASE_krb5;
 199         goto egress;
 200     }
 201
 202     errcode = check_indicators(kdc_context, state->server,
 203                                state->auth_indicators);
 204     if (errcode) {
 205         state->status = "HIGHER_AUTHENTICATION_REQUIRED";
 206         goto egress;
 207     }
 208
 209     state->ticket_reply.enc_part2 = &state->enc_tkt_reply;
 210
 211     errcode = check_kdcpolicy_as(kdc_context, state->request, state->client,
 212                                  state->server, state->auth_indicators,
 213                                  state->kdc_time, &state->enc_tkt_reply.times,
 214                                  &state->status);
 215     if (errcode)
 216         goto egress;
 217
 218     /*
 219      * Find the server key
 220      */
 221     if ((errcode = krb5_dbe_find_enctype(kdc_context, state->server,
 222                                          -1, /* ignore keytype   */
 223                                          -1, /* Ignore salttype  */
 224                                          0,  /* Get highest kvno */
 225                                          &server_key))) {
 226         state->status = "FINDING_SERVER_KEY";
 227         goto egress;
 228     }
 229
 230     /*
 231      * Convert server->key into a real key
 232      * (it may be encrypted in the database)
 233      *
 234      *  server_keyblock is later used to generate auth data signatures
 235      */
 236     if ((errcode = krb5_dbe_decrypt_key_data(kdc_context, NULL,
 237                                              server_key,
 238                                              &state->server_keyblock,
 239                                              NULL))) {
 240         state->status = "DECRYPT_SERVER_KEY";
 241         goto egress;
 242     }
 243
 244     /* Start assembling the response */
 245     state->reply.msg_type = KRB5_AS_REP;
 246     state->reply.client = state->enc_tkt_reply.client; /* post canonization */
 247     state->reply.ticket = &state->ticket_reply;
 248     state->reply_encpart.session = &state->session_key;
 249     if ((errcode = fetch_last_req_info(state->client,
 250                                        &state->reply_encpart.last_req)))
 251         goto egress;
 252     state->reply_encpart.nonce = state->request->nonce;
 253     state->reply_encpart.key_exp = get_key_exp(state->client);
 254     state->reply_encpart.flags = state->enc_tkt_reply.flags;
 255     state->reply_encpart.server = state->ticket_reply.server;
 256
 257     /* copy the time fields EXCEPT for authtime; it's location
 258      *  is used for ktime
 259      */
 260     state->reply_encpart.times = state->enc_tkt_reply.times;
 261     state->reply_encpart.times.authtime = state->authtime = state->kdc_time;
 262
 263     state->reply_encpart.caddrs = state->enc_tkt_reply.caddrs;
 264     state->reply_encpart.enc_padata = NULL;
 265
 266     /* Fetch the padata info to be returned (do this before
 267      *  authdata to handle possible replacement of reply key
 268      */
 269     errcode = return_padata(kdc_context, &state->rock, state->req_pkt,
 270                             state->request, &state->reply,
 271                             &state->client_keyblock, &state->pa_context);
 272     if (errcode) {
 273         state->status = "KDC_RETURN_PADATA";
 274         goto egress;
 275     }
 276
 277     /* If we didn't find a client long-term key and no preauth mechanism
 278      * replaced the reply key, error out now. */
 279     if (state->client_keyblock.enctype == ENCTYPE_NULL) {
 280         state->status = "CANT_FIND_CLIENT_KEY";
 281         errcode = KRB5KDC_ERR_ETYPE_NOSUPP;
 282         goto egress;
 283     }
 284
 285     errcode = handle_authdata(kdc_context,
 286                               state->c_flags,
 287                               state->client,
 288                               state->server,
 289                               NULL,
 290                               state->local_tgt,
 291                               &state->client_keyblock,
 292                               &state->server_keyblock,
 293                               NULL,
 294                               state->req_pkt,
 295                               state->request,
 296                               NULL, /* for_user_princ */
 297                               NULL, /* enc_tkt_request */
 298                               state->auth_indicators,
 299                               &state->enc_tkt_reply);
 300     if (errcode) {
 301         krb5_klog_syslog(LOG_INFO, _("AS_REQ : handle_authdata (%d)"),
 302                          errcode);
 303         state->status = "HANDLE_AUTHDATA";
 304         goto egress;
 305     }
 306
 307     errcode = krb5_encrypt_tkt_part(kdc_context, &state->server_keyblock,
 308                                     &state->ticket_reply);
 309     if (errcode)
 310         goto egress;
 311
 312     errcode = kau_make_tkt_id(kdc_context, &state->ticket_reply,
 313                               &au_state->tkt_out_id);
 314     if (errcode)
 315         goto egress;
 316
 317     state->ticket_reply.enc_part.kvno = server_key->key_data_kvno;
 318     errcode = kdc_fast_response_handle_padata(state->rstate,
 319                                               state->request,
 320                                               &state->reply,
 321                                               state->client_keyblock.enctype);
 322     if (errcode)
 323         goto egress;
 324
 325     /* now encode/encrypt the response */
 326
 327     state->reply.enc_part.enctype = state->client_keyblock.enctype;
 328
 329     errcode = kdc_fast_handle_reply_key(state->rstate, &state->client_keyblock,
 330                                         &as_encrypting_key);
 331     if (errcode)
 332         goto egress;
 333     errcode = return_enc_padata(kdc_context, state->req_pkt, state->request,
 334                                 as_encrypting_key, state->server,
 335                                 &state->reply_encpart, FALSE);
 336     if (errcode) {
 337         state->status = "KDC_RETURN_ENC_PADATA";
 338         goto egress;
 339     }
 340
 341     if (kdc_fast_hide_client(state->rstate))
 342         state->reply.client = (krb5_principal)krb5_anonymous_principal();
 343     errcode = krb5_encode_kdc_rep(kdc_context, KRB5_AS_REP,
 344                                   &state->reply_encpart, 0,
 345                                   as_encrypting_key,
 346                                   &state->reply, &response);
 347     if (state->client_key != NULL)
 348         state->reply.enc_part.kvno = state->client_key->key_data_kvno;
 349     if (errcode)
 350         goto egress;
 351
 352     /* these parts are left on as a courtesy from krb5_encode_kdc_rep so we
 353        can use them in raw form if needed.  But, we don't... */
 354     memset(state->reply.enc_part.ciphertext.data, 0,
 355            state->reply.enc_part.ciphertext.length);
 356     free(state->reply.enc_part.ciphertext.data);
 357
 358     log_as_req(kdc_context, state->local_addr, state->remote_addr,
 359                state->request, &state->reply, state->client, state->cname,
 360                state->server, state->sname, state->authtime, 0, 0, 0);
 361     did_log = 1;
 362
 363 egress:
 364     if (errcode != 0 && state->status == NULL)
 365         state->status = "UNKNOWN_REASON";
 366
 367     au_state->status = state->status;
 368     au_state->reply = &state->reply;
 369     kau_as_req(kdc_context,
 370               (errcode || state->preauth_err) ? FALSE : TRUE, au_state);
 371     kau_free_kdc_req(au_state);
 372
 373     free_padata_context(kdc_context, state->pa_context);
 374     if (as_encrypting_key)
 375         krb5_free_keyblock(kdc_context, as_encrypting_key);
 376     if (errcode)
 377         emsg = krb5_get_error_message(kdc_context, errcode);
 378
 379     if (state->status) {
 380         log_as_req(kdc_context, state->local_addr, state->remote_addr,
 381                    state->request, &state->reply, state->client,
 382                    state->cname, state->server, state->sname, state->authtime,
 383                    state->status, errcode, emsg);
 384         did_log = 1;
 385     }
 386     if (errcode) {
 387         if (state->status == 0) {
 388             state->status = emsg;
 389         }
 390         if (errcode != KRB5KDC_ERR_DISCARD) {
 391             errcode -= ERROR_TABLE_BASE_krb5;
 392             if (errcode < 0 || errcode > KRB_ERR_MAX)
 393                 errcode = KRB_ERR_GENERIC;
 394
 395             errcode = prepare_error_as(state->rstate, state->request,
 396                                        state->local_tgt, errcode,
 397                                        state->e_data, state->typed_e_data,
 398                                        ((state->client != NULL) ?
 399                                         state->client->princ : NULL),
 400                                        &response, state->status);
 401             state->status = 0;
 402         }
 403     }
 404
 405     if (emsg)
 406         krb5_free_error_message(kdc_context, emsg);
 407     if (state->enc_tkt_reply.authorization_data != NULL)
 408         krb5_free_authdata(kdc_context,
 409                            state->enc_tkt_reply.authorization_data);
 410     if (state->server_keyblock.contents != NULL)
 411         krb5_free_keyblock_contents(kdc_context, &state->server_keyblock);
 412     if (state->client_keyblock.contents != NULL)
 413         krb5_free_keyblock_contents(kdc_context, &state->client_keyblock);
 414     if (state->reply.padata != NULL)
 415         krb5_free_pa_data(kdc_context, state->reply.padata);
 416     if (state->reply_encpart.enc_padata)
 417         krb5_free_pa_data(kdc_context, state->reply_encpart.enc_padata);
 418
 419     if (state->cname != NULL)
 420         free(state->cname);
 421     if (state->sname != NULL)
 422         free(state->sname);
 423     krb5_db_free_principal(kdc_context, state->client);
 424     krb5_db_free_principal(kdc_context, state->server);
 425     krb5_db_free_principal(kdc_context, state->local_tgt_storage);
 426     if (state->session_key.contents != NULL)
 427         krb5_free_keyblock_contents(kdc_context, &state->session_key);
 428     if (state->ticket_reply.enc_part.ciphertext.data != NULL) {
 429         memset(state->ticket_reply.enc_part.ciphertext.data , 0,
 430                state->ticket_reply.enc_part.ciphertext.length);
 431         free(state->ticket_reply.enc_part.ciphertext.data);
 432     }
 433
 434     krb5_free_pa_data(kdc_context, state->e_data);
 435     krb5_free_data(kdc_context, state->inner_body);
 436     kdc_free_rstate(state->rstate);
 437     krb5_free_kdc_req(kdc_context, state->request);
 438     k5_free_data_ptr_list(state->auth_indicators);
 439     assert(did_log != 0);
 440
 441     free(state);
 442     (*oldrespond)(oldarg, errcode, response);
 443 }
 444
 445 static void
 446 finish_missing_required_preauth(void *arg)
 447 {
 448     struct as_req_state *state = (struct as_req_state *)arg;
 449
 450     finish_process_as_req(state, state->preauth_err);
 451 }
 452
 453 static void
 454 finish_preauth(void *arg, krb5_error_code code)
 455 {
 456     struct as_req_state *state = arg;
 457     krb5_error_code real_code = code;
 458
 459     if (code) {
 460         if (vague_errors)
 461             code = KRB5KRB_ERR_GENERIC;
 462         state->status = "PREAUTH_FAILED";
 463         if (real_code == KRB5KDC_ERR_PREAUTH_FAILED) {
 464             state->preauth_err = code;
 465             get_preauth_hint_list(state->request, &state->rock, &state->e_data,
 466                                   finish_missing_required_preauth, state);
 467             return;
 468         }
 469     } else {
 470         /*
 471          * Final check before handing out ticket: If the client requires
 472          * preauthentication, verify that the proper kind of
 473          * preauthentication was carried out.
 474          */
 475         state->status = missing_required_preauth(state->client, state->server,
 476                                                  &state->enc_tkt_reply);
 477         if (state->status) {
 478             state->preauth_err = KRB5KDC_ERR_PREAUTH_REQUIRED;
 479             get_preauth_hint_list(state->request, &state->rock, &state->e_data,
 480                                   finish_missing_required_preauth, state);
 481             return;
 482         }
 483     }
 484
 485     finish_process_as_req(state, code);
 486 }
 487
 488 /*ARGSUSED*/
 489 void
 490 process_as_req(krb5_kdc_req *request, krb5_data *req_pkt,
 491                const krb5_fulladdr *local_addr,
 492                const krb5_fulladdr *remote_addr, kdc_realm_t *kdc_active_realm,
 493                verto_ctx *vctx, loop_respond_fn respond, void *arg)
 494 {
 495     krb5_error_code errcode;
 496     unsigned int s_flags = 0;
 497     krb5_data encoded_req_body;
 498     krb5_enctype useenctype;
 499     struct as_req_state *state;
 500     krb5_audit_state *au_state = NULL;
 501
 502     state = k5alloc(sizeof(*state), &errcode);
 503     if (state == NULL) {
 504         (*respond)(arg, errcode, NULL);
 505         return;
 506     }
 507     state->respond = respond;
 508     state->arg = arg;
 509     state->request = request;
 510     state->req_pkt = req_pkt;
 511     state->local_addr = local_addr;
 512     state->remote_addr = remote_addr;
 513     state->active_realm = kdc_active_realm;
 514
 515     errcode = kdc_make_rstate(kdc_active_realm, &state->rstate);
 516     if (errcode != 0) {
 517         (*respond)(arg, errcode, NULL);
 518         free(state);
 519         return;
 520     }
 521
 522     /* Initialize audit state. */
 523     errcode = kau_init_kdc_req(kdc_context, state->request, remote_addr,
 524                                &au_state);
 525     if (errcode) {
 526         (*respond)(arg, errcode, NULL);
 527         kdc_free_rstate(state->rstate);
 528         free(state);
 529         return;
 530     }
 531     state->au_state = au_state;
 532
 533     if (state->request->msg_type != KRB5_AS_REQ) {
 534         state->status = "VALIDATE_MESSAGE_TYPE";
 535         errcode = KRB5_BADMSGTYPE;
 536         goto errout;
 537     }
 538
 539     /* Seed the audit trail with the request ID and basic information. */
 540     kau_as_req(kdc_context, TRUE, au_state);
 541
 542     if (fetch_asn1_field((unsigned char *) req_pkt->data,
 543                          1, 4, &encoded_req_body) != 0) {
 544         errcode = ASN1_BAD_ID;
 545         goto errout;
 546     }
 547     errcode = kdc_find_fast(&state->request, &encoded_req_body, NULL, NULL,
 548                             state->rstate, &state->inner_body);
 549     if (errcode) {
 550         state->status = "FIND_FAST";
 551         goto errout;
 552     }
 553     if (state->inner_body == NULL) {
 554         /* Not a FAST request; copy the encoded request body. */
 555         errcode = krb5_copy_data(kdc_context, &encoded_req_body,
 556                                  &state->inner_body);
 557         if (errcode)
 558             goto errout;
 559     }
 560     au_state->request = state->request;
 561     state->rock.request = state->request;
 562     state->rock.inner_body = state->inner_body;
 563     state->rock.rstate = state->rstate;
 564     state->rock.vctx = vctx;
 565     state->rock.auth_indicators = &state->auth_indicators;
 566     state->rock.send_freshness_token = FALSE;
 567     if (!state->request->client) {
 568         state->status = "NULL_CLIENT";
 569         errcode = KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
 570         goto errout;
 571     }
 572     if ((errcode = krb5_unparse_name(kdc_context,
 573                                      state->request->client,
 574                                      &state->cname)))
 575         goto errout;
 576     limit_string(state->cname);
 577
 578     if (!state->request->server) {
 579         state->status = "NULL_SERVER";
 580         errcode = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
 581         goto errout;
 582     }
 583     if ((errcode = krb5_unparse_name(kdc_context,
 584                                      state->request->server,
 585                                      &state->sname)))
 586         goto errout;
 587     limit_string(state->sname);
 588
 589     /*
 590      * We set KRB5_KDB_FLAG_CLIENT_REFERRALS_ONLY as a hint
 591      * to the backend to return naming information in lieu
 592      * of cross realm TGS entries.
 593      */
 594     setflag(state->c_flags, KRB5_KDB_FLAG_CLIENT_REFERRALS_ONLY);
 595     /*
 596      * Note that according to the referrals draft we should
 597      * always canonicalize enterprise principal names.
 598      */
 599     if (isflagset(state->request->kdc_options, KDC_OPT_CANONICALIZE) ||
 600         state->request->client->type == KRB5_NT_ENTERPRISE_PRINCIPAL) {
 601         setflag(state->c_flags, KRB5_KDB_FLAG_CANONICALIZE);
 602         setflag(state->c_flags, KRB5_KDB_FLAG_ALIAS_OK);
 603     }
 604     if (include_pac_p(kdc_context, state->request)) {
 605         setflag(state->c_flags, KRB5_KDB_FLAG_INCLUDE_PAC);
 606     }
 607     errcode = krb5_db_get_principal(kdc_context, state->request->client,
 608                                     state->c_flags, &state->client);
 609     if (errcode == KRB5_KDB_CANTLOCK_DB)
 610         errcode = KRB5KDC_ERR_SVC_UNAVAILABLE;
 611     if (errcode == KRB5_KDB_NOENTRY) {
 612         state->status = "CLIENT_NOT_FOUND";
 613         if (vague_errors)
 614             errcode = KRB5KRB_ERR_GENERIC;
 615         else
 616             errcode = KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
 617         goto errout;
 618     } else if (errcode) {
 619         state->status = "LOOKING_UP_CLIENT";
 620         goto errout;
 621     }
 622     state->rock.client = state->client;
 623
 624     /*
 625      * If the backend returned a principal that is not in the local
 626      * realm, then we need to refer the client to that realm.
 627      */
 628     if (!is_local_principal(kdc_active_realm, state->client->princ)) {
 629         /* Entry is a referral to another realm */
 630         state->status = "REFERRAL";
 631         au_state->cl_realm = &state->client->princ->realm;
 632         errcode = KRB5KDC_ERR_WRONG_REALM;
 633         goto errout;
 634     }
 635
 636     au_state->stage = SRVC_PRINC;
 637
 638     s_flags = 0;
 639     setflag(s_flags, KRB5_KDB_FLAG_ALIAS_OK);
 640     if (isflagset(state->request->kdc_options, KDC_OPT_CANONICALIZE)) {
 641         setflag(s_flags, KRB5_KDB_FLAG_CANONICALIZE);
 642     }
 643     errcode = krb5_db_get_principal(kdc_context, state->request->server,
 644                                     s_flags, &state->server);
 645     if (errcode == KRB5_KDB_CANTLOCK_DB)
 646         errcode = KRB5KDC_ERR_SVC_UNAVAILABLE;
 647     if (errcode == KRB5_KDB_NOENTRY) {
 648         state->status = "SERVER_NOT_FOUND";
 649         errcode = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
 650         goto errout;
 651     } else if (errcode) {
 652         state->status = "LOOKING_UP_SERVER";
 653         goto errout;
 654     }
 655
 656     errcode = get_local_tgt(kdc_context, &state->request->server->realm,
 657                             state->server, &state->local_tgt,
 658                             &state->local_tgt_storage);
 659     if (errcode) {
 660         state->status = "GET_LOCAL_TGT";
 661         goto errout;
 662     }
 663     state->rock.local_tgt = state->local_tgt;
 664
 665     au_state->stage = VALIDATE_POL;
 666
 667     if ((errcode = krb5_timeofday(kdc_context, &state->kdc_time)))
 668         goto errout;
 669     state->authtime = state->kdc_time; /* for audit_as_request() */
 670
 671     if ((errcode = validate_as_request(kdc_active_realm,
 672                                        state->request, *state->client,
 673                                        *state->server, state->kdc_time,
 674                                        &state->status, &state->e_data))) {
 675         errcode += ERROR_TABLE_BASE_krb5;
 676         goto errout;
 677     }
 678
 679     au_state->stage = ISSUE_TKT;
 680
 681     /*
 682      * Select the keytype for the ticket session key.
 683      */
 684     if ((useenctype = select_session_keytype(kdc_active_realm, state->server,
 685                                              state->request->nktypes,
 686                                              state->request->ktype)) == 0) {
 687         /* unsupported ktype */
 688         state->status = "BAD_ENCRYPTION_TYPE";
 689         errcode = KRB5KDC_ERR_ETYPE_NOSUPP;
 690         goto errout;
 691     }
 692
 693     if ((errcode = krb5_c_make_random_key(kdc_context, useenctype,
 694                                           &state->session_key)))
 695         goto errout;
 696
 697     /*
 698      * Canonicalization is only effective if we are issuing a TGT
 699      * (the intention is to allow support for Windows "short" realm
 700      * aliases, nothing more).
 701      */
 702     if (isflagset(s_flags, KRB5_KDB_FLAG_CANONICALIZE) &&
 703         krb5_is_tgs_principal(state->request->server) &&
 704         krb5_is_tgs_principal(state->server->princ)) {
 705         state->ticket_reply.server = state->server->princ;
 706     } else {
 707         state->ticket_reply.server = state->request->server;
 708     }
 709
 710     /* Copy options that request the corresponding ticket flags. */
 711     state->enc_tkt_reply.flags = OPTS2FLAGS(state->request->kdc_options);
 712     state->enc_tkt_reply.times.authtime = state->authtime;
 713
 714     setflag(state->enc_tkt_reply.flags, TKT_FLG_INITIAL);
 715     setflag(state->enc_tkt_reply.flags, TKT_FLG_ENC_PA_REP);
 716
 717     /*
 718      * It should be noted that local policy may affect the
 719      * processing of any of these flags.  For example, some
 720      * realms may refuse to issue renewable tickets
 721      */
 722
 723     state->enc_tkt_reply.session = &state->session_key;
 724     if (isflagset(state->c_flags, KRB5_KDB_FLAG_CANONICALIZE)) {
 725         state->client_princ = *(state->client->princ);
 726     } else {
 727         state->client_princ = *(state->request->client);
 728         /* The realm is always canonicalized */
 729         state->client_princ.realm = state->client->princ->realm;
 730     }
 731     state->enc_tkt_reply.client = &state->client_princ;
 732     state->enc_tkt_reply.transited.tr_type = KRB5_DOMAIN_X500_COMPRESS;
 733     state->enc_tkt_reply.transited.tr_contents = empty_string;
 734
 735     if (isflagset(state->request->kdc_options, KDC_OPT_POSTDATED)) {
 736         setflag(state->enc_tkt_reply.flags, TKT_FLG_INVALID);
 737         state->enc_tkt_reply.times.starttime = state->request->from;
 738     } else
 739         state->enc_tkt_reply.times.starttime = state->kdc_time;
 740
 741     kdc_get_ticket_endtime(kdc_active_realm,
 742                            state->enc_tkt_reply.times.starttime,
 743                            kdc_infinity, state->request->till, state->client,
 744                            state->server, &state->enc_tkt_reply.times.endtime);
 745
 746     kdc_get_ticket_renewtime(kdc_active_realm, state->request, NULL,
 747                              state->client, state->server,
 748                              &state->enc_tkt_reply);
 749
 750     /*
 751      * starttime is optional, and treated as authtime if not present.
 752      * so we can nuke it if it matches
 753      */
 754     if (state->enc_tkt_reply.times.starttime ==
 755         state->enc_tkt_reply.times.authtime)
 756         state->enc_tkt_reply.times.starttime = 0;
 757
 758     state->enc_tkt_reply.caddrs = state->request->addresses;
 759     state->enc_tkt_reply.authorization_data = 0;
 760
 761     /* If anonymous requests are being used, adjust the realm of the client
 762      * principal. */
 763     if (isflagset(state->request->kdc_options, KDC_OPT_REQUEST_ANONYMOUS)) {
 764         if (!krb5_principal_compare_any_realm(kdc_context,
 765                                               state->request->client,
 766                                               krb5_anonymous_principal())) {
 767             errcode = KRB5KDC_ERR_BADOPTION;
 768             /* Anonymous requested but anonymous principal not used.*/
 769             state->status = "VALIDATE_ANONYMOUS_PRINCIPAL";
 770             goto errout;
 771         }
 772         krb5_free_principal(kdc_context, state->request->client);
 773         state->request->client = NULL;
 774         errcode = krb5_copy_principal(kdc_context, krb5_anonymous_principal(),
 775                                       &state->request->client);
 776         if (errcode)
 777             goto errout;
 778         state->enc_tkt_reply.client = state->request->client;
 779         setflag(state->client->attributes, KRB5_KDB_REQUIRES_PRE_AUTH);
 780     }
 781
 782     errcode = select_client_key(kdc_context, state->client,
 783                                 state->request->ktype, state->request->nktypes,
 784                                 &state->client_keyblock, &state->client_key);
 785     if (errcode) {
 786         state->status = "DECRYPT_CLIENT_KEY";
 787         goto errout;
 788     }
 789     if (state->client_key != NULL) {
 790         state->rock.client_key = state->client_key;
 791         state->rock.client_keyblock = &state->client_keyblock;
 792     }
 793
 794     errcode = kdc_fast_read_cookie(kdc_context, state->rstate, state->request,
 795                                    state->local_tgt);
 796     if (errcode) {
 797         state->status = "READ_COOKIE";
 798         goto errout;
 799     }
 800
 801     /*
 802      * Check the preauthentication if it is there.
 803      */
 804     if (state->request->padata) {
 805         check_padata(kdc_context, &state->rock, state->req_pkt,
 806                      state->request, &state->enc_tkt_reply, &state->pa_context,
 807                      &state->e_data, &state->typed_e_data, finish_preauth,
 808                      state);
 809     } else
 810         finish_preauth(state, 0);
 811     return;
 812
 813 errout:
 814     finish_process_as_req(state, errcode);
 815 }
 816
 817 static krb5_error_code
 818 prepare_error_as(struct kdc_request_state *rstate, krb5_kdc_req *request,
 819                  krb5_db_entry *local_tgt, int error, krb5_pa_data **e_data_in,
 820                  krb5_boolean typed_e_data, krb5_principal canon_client,
 821                  krb5_data **response, const char *status)
 822 {
 823     krb5_error errpkt;
 824     krb5_error_code retval;
 825     krb5_data *scratch = NULL, *e_data_asn1 = NULL, *fast_edata = NULL;
 826     krb5_pa_data **e_data = NULL, *cookie = NULL;
 827     kdc_realm_t *kdc_active_realm = rstate->realm_data;
 828     size_t count;
 829
 830     errpkt.magic = KV5M_ERROR;
 831
 832     if (e_data_in != NULL) {
 833         /* Add a PA-FX-COOKIE to e_data_in.  e_data is a shallow copy
 834          * containing aliases. */
 835         for (count = 0; e_data_in[count] != NULL; count++);
 836         e_data = calloc(count + 2, sizeof(*e_data));
 837         if (e_data == NULL)
 838             return ENOMEM;
 839         memcpy(e_data, e_data_in, count * sizeof(*e_data));
 840         retval = kdc_fast_make_cookie(kdc_context, rstate, local_tgt,
 841                                       request->client, &cookie);
 842         e_data[count] = cookie;
 843     }
 844
 845     errpkt.ctime = 0;
 846     errpkt.cusec = 0;
 847
 848     retval = krb5_us_timeofday(kdc_context, &errpkt.stime, &errpkt.susec);
 849     if (retval)
 850         goto cleanup;
 851     errpkt.error = error;
 852     errpkt.server = request->server;
 853     errpkt.client = (error == KDC_ERR_WRONG_REALM) ? canon_client :
 854         request->client;
 855     errpkt.text = string2data((char *)status);
 856
 857     if (e_data != NULL) {
 858         if (typed_e_data)
 859             retval = encode_krb5_typed_data(e_data, &e_data_asn1);
 860         else
 861             retval = encode_krb5_padata_sequence(e_data, &e_data_asn1);
 862         if (retval)
 863             goto cleanup;
 864         errpkt.e_data = *e_data_asn1;
 865     } else
 866         errpkt.e_data = empty_data();
 867
 868     retval = kdc_fast_handle_error(kdc_context, rstate, request, e_data,
 869                                    &errpkt, &fast_edata);
 870     if (retval)
 871         goto cleanup;
 872     if (fast_edata != NULL)
 873         errpkt.e_data = *fast_edata;
 874
 875     scratch = k5alloc(sizeof(*scratch), &retval);
 876     if (scratch == NULL)
 877         goto cleanup;
 878     if (kdc_fast_hide_client(rstate) && errpkt.client != NULL)
 879         errpkt.client = (krb5_principal)krb5_anonymous_principal();
 880     retval = krb5_mk_error(kdc_context, &errpkt, scratch);
 881     if (retval)
 882         goto cleanup;
 883
 884     *response = scratch;
 885     scratch = NULL;
 886
 887 cleanup:
 888     krb5_free_data(kdc_context, fast_edata);
 889     krb5_free_data(kdc_context, e_data_asn1);
 890     free(scratch);
 891     free(e_data);
 892     if (cookie != NULL)
 893         free(cookie->contents);
 894     free(cookie);
 895     return retval;
 896 }