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 by the Massachusetts Institute of Technology.
   6  * 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 "policy.h"
  72 #include "adm.h"
  73 #include "adm_proto.h"
  74 #include "extern.h"
  75
  76 #if APPLE_PKINIT
  77 #define     AS_REQ_DEBUG    0
  78 #if         AS_REQ_DEBUG
  79 #define     asReqDebug(args...)       printf(args)
  80 #else
  81 #define     asReqDebug(args...)
  82 #endif
  83 #endif /* APPLE_PKINIT */
  84
  85 static krb5_error_code
  86 prepare_error_as(struct kdc_request_state *, krb5_kdc_req *,
  87                  int, krb5_pa_data **, krb5_boolean, krb5_principal,
  88                  krb5_data **, const char *);
  89
  90 /* Determine the key-expiration value according to RFC 4120 section 5.4.2. */
  91 static krb5_timestamp
  92 get_key_exp(krb5_db_entry *entry)
  93 {
  94     if (entry->expiration == 0)
  95         return entry->pw_expiration;
  96     if (entry->pw_expiration == 0)
  97         return entry->expiration;
  98     return min(entry->expiration, entry->pw_expiration);
  99 }
 100
 101 struct as_req_state {
 102     loop_respond_fn respond;
 103     void *arg;
 104
 105     krb5_enc_tkt_part enc_tkt_reply;
 106     krb5_enc_kdc_rep_part reply_encpart;
 107     krb5_ticket ticket_reply;
 108     krb5_keyblock server_keyblock;
 109     krb5_keyblock client_keyblock;
 110     krb5_db_entry *client;
 111     krb5_db_entry *server;
 112     krb5_kdc_req *request;
 113     struct krb5_kdcpreauth_rock_st rock;
 114     const char *status;
 115     krb5_pa_data **e_data;
 116     krb5_boolean typed_e_data;
 117     krb5_kdc_rep reply;
 118     krb5_timestamp kdc_time;
 119     krb5_timestamp authtime;
 120     krb5_keyblock session_key;
 121     unsigned int c_flags;
 122     krb5_data *req_pkt;
 123     struct kdc_request_state *rstate;
 124     char *sname, *cname;
 125     void *pa_context;
 126     const krb5_fulladdr *from;
 127
 128     krb5_error_code preauth_err;
 129 };
 130
 131 static void
 132 finish_process_as_req(struct as_req_state *state, krb5_error_code errcode)
 133 {
 134     krb5_key_data *server_key;
 135     krb5_key_data *client_key;
 136     krb5_keyblock *as_encrypting_key = NULL;
 137     krb5_data *response = NULL;
 138     const char *emsg = 0;
 139     int did_log = 0;
 140     register int i;
 141     krb5_enctype useenctype;
 142     loop_respond_fn oldrespond;
 143     void *oldarg;
 144
 145     assert(state);
 146     oldrespond = state->respond;
 147     oldarg = state->arg;
 148
 149     if (errcode)
 150         goto egress;
 151
 152     if ((errcode = validate_forwardable(state->request, *state->client,
 153                                         *state->server, state->kdc_time,
 154                                         &state->status))) {
 155         errcode += ERROR_TABLE_BASE_krb5;
 156         goto egress;
 157     }
 158
 159     state->ticket_reply.enc_part2 = &state->enc_tkt_reply;
 160
 161     /*
 162      * Find the server key
 163      */
 164     if ((errcode = krb5_dbe_find_enctype(kdc_context, state->server,
 165                                          -1, /* ignore keytype   */
 166                                          -1, /* Ignore salttype  */
 167                                          0,  /* Get highest kvno */
 168                                          &server_key))) {
 169         state->status = "FINDING_SERVER_KEY";
 170         goto egress;
 171     }
 172
 173     /*
 174      * Convert server->key into a real key
 175      * (it may be encrypted in the database)
 176      *
 177      *  server_keyblock is later used to generate auth data signatures
 178      */
 179     if ((errcode = krb5_dbe_decrypt_key_data(kdc_context, NULL,
 180                                              server_key,
 181                                              &state->server_keyblock,
 182                                              NULL))) {
 183         state->status = "DECRYPT_SERVER_KEY";
 184         goto egress;
 185     }
 186
 187     /*
 188      * Find the appropriate client key.  We search in the order specified
 189      * by request keytype list.
 190      */
 191     client_key = NULL;
 192     for (i = 0; i < state->request->nktypes; i++) {
 193         useenctype = state->request->ktype[i];
 194         if (!krb5_c_valid_enctype(useenctype))
 195             continue;
 196
 197         if (!krb5_dbe_find_enctype(kdc_context, state->client,
 198                                    useenctype, -1, 0, &client_key))
 199             break;
 200     }
 201     if (!(client_key)) {
 202         /* Cannot find an appropriate key */
 203         state->status = "CANT_FIND_CLIENT_KEY";
 204         errcode = KRB5KDC_ERR_ETYPE_NOSUPP;
 205         goto egress;
 206     }
 207     state->rock.client_key = client_key;
 208
 209     /* convert client.key_data into a real key */
 210     if ((errcode = krb5_dbe_decrypt_key_data(kdc_context, NULL,
 211                                              client_key,
 212                                              &state->client_keyblock,
 213                                              NULL))) {
 214         state->status = "DECRYPT_CLIENT_KEY";
 215         goto egress;
 216     }
 217     state->client_keyblock.enctype = useenctype;
 218
 219     /* Start assembling the response */
 220     state->reply.msg_type = KRB5_AS_REP;
 221     state->reply.client = state->enc_tkt_reply.client; /* post canonization */
 222     state->reply.ticket = &state->ticket_reply;
 223     state->reply_encpart.session = &state->session_key;
 224     if ((errcode = fetch_last_req_info(state->client,
 225                                        &state->reply_encpart.last_req))) {
 226         state->status = "FETCH_LAST_REQ";
 227         goto egress;
 228     }
 229     state->reply_encpart.nonce = state->request->nonce;
 230     state->reply_encpart.key_exp = get_key_exp(state->client);
 231     state->reply_encpart.flags = state->enc_tkt_reply.flags;
 232     state->reply_encpart.server = state->ticket_reply.server;
 233
 234     /* copy the time fields EXCEPT for authtime; it's location
 235      *  is used for ktime
 236      */
 237     state->reply_encpart.times = state->enc_tkt_reply.times;
 238     state->reply_encpart.times.authtime = state->authtime = state->kdc_time;
 239
 240     state->reply_encpart.caddrs = state->enc_tkt_reply.caddrs;
 241     state->reply_encpart.enc_padata = NULL;
 242
 243     /* Fetch the padata info to be returned (do this before
 244      *  authdata to handle possible replacement of reply key
 245      */
 246     errcode = return_padata(kdc_context, &state->rock, state->req_pkt,
 247                             state->request, &state->reply,
 248                             &state->client_keyblock, &state->pa_context);
 249     if (errcode) {
 250         state->status = "KDC_RETURN_PADATA";
 251         goto egress;
 252     }
 253
 254 #if APPLE_PKINIT
 255     asReqDebug("process_as_req reply realm %s name %s\n",
 256                reply.client->realm.data, reply.client->data->data);
 257 #endif /* APPLE_PKINIT */
 258
 259
 260
 261     errcode = handle_authdata(kdc_context,
 262                               state->c_flags,
 263                               state->client,
 264                               state->server,
 265                               state->server,
 266                               &state->client_keyblock,
 267                               &state->server_keyblock,
 268                               &state->server_keyblock,
 269                               state->req_pkt,
 270                               state->request,
 271                               NULL, /* for_user_princ */
 272                               NULL, /* enc_tkt_request */
 273                               &state->enc_tkt_reply);
 274     if (errcode) {
 275         krb5_klog_syslog(LOG_INFO, _("AS_REQ : handle_authdata (%d)"),
 276                          errcode);
 277         state->status = "HANDLE_AUTHDATA";
 278         goto egress;
 279     }
 280
 281     errcode = krb5_encrypt_tkt_part(kdc_context, &state->server_keyblock,
 282                                     &state->ticket_reply);
 283     if (errcode) {
 284         state->status = "ENCRYPTING_TICKET";
 285         goto egress;
 286     }
 287     state->ticket_reply.enc_part.kvno = server_key->key_data_kvno;
 288     errcode = kdc_fast_response_handle_padata(state->rstate,
 289                                               state->request,
 290                                               &state->reply,
 291                                               state->client_keyblock.enctype);
 292     if (errcode) {
 293         state->status = "fast response handling";
 294         goto egress;
 295     }
 296
 297     /* now encode/encrypt the response */
 298
 299     state->reply.enc_part.enctype = state->client_keyblock.enctype;
 300
 301     errcode = kdc_fast_handle_reply_key(state->rstate, &state->client_keyblock,
 302                                         &as_encrypting_key);
 303     if (errcode) {
 304         state->status = "generating reply key";
 305         goto egress;
 306     }
 307     errcode = return_enc_padata(kdc_context, state->req_pkt, state->request,
 308                                 as_encrypting_key, state->server,
 309                                 &state->reply_encpart, FALSE);
 310     if (errcode) {
 311         state->status = "KDC_RETURN_ENC_PADATA";
 312         goto egress;
 313     }
 314
 315     errcode = krb5_encode_kdc_rep(kdc_context, KRB5_AS_REP,
 316                                   &state->reply_encpart, 0,
 317                                   as_encrypting_key,
 318                                   &state->reply, &response);
 319     state->reply.enc_part.kvno = client_key->key_data_kvno;
 320     if (errcode) {
 321         state->status = "ENCODE_KDC_REP";
 322         goto egress;
 323     }
 324
 325     /* these parts are left on as a courtesy from krb5_encode_kdc_rep so we
 326        can use them in raw form if needed.  But, we don't... */
 327     memset(state->reply.enc_part.ciphertext.data, 0,
 328            state->reply.enc_part.ciphertext.length);
 329     free(state->reply.enc_part.ciphertext.data);
 330
 331     log_as_req(state->from, state->request, &state->reply,
 332                state->client, state->cname, state->server,
 333                state->sname, state->authtime, 0, 0, 0);
 334     did_log = 1;
 335
 336 egress:
 337     if (errcode != 0)
 338         assert (state->status != 0);
 339     free_padata_context(kdc_context, state->pa_context);
 340     if (as_encrypting_key)
 341         krb5_free_keyblock(kdc_context, as_encrypting_key);
 342     if (errcode)
 343         emsg = krb5_get_error_message(kdc_context, errcode);
 344
 345     if (state->status) {
 346         log_as_req(state->from, state->request, &state->reply, state->client,
 347                    state->cname, state->server, state->sname, state->authtime,
 348                    state->status, errcode, emsg);
 349         did_log = 1;
 350     }
 351     if (errcode) {
 352         if (state->status == 0) {
 353             state->status = emsg;
 354         }
 355         if (errcode != KRB5KDC_ERR_DISCARD) {
 356             errcode -= ERROR_TABLE_BASE_krb5;
 357             if (errcode < 0 || errcode > 128)
 358                 errcode = KRB_ERR_GENERIC;
 359
 360             errcode = prepare_error_as(state->rstate, state->request,
 361                                        errcode, state->e_data,
 362                                        state->typed_e_data,
 363                                        ((state->client != NULL) ?
 364                                         state->client->princ : NULL),
 365                                        &response, state->status);
 366             state->status = 0;
 367         }
 368     }
 369
 370     if (emsg)
 371         krb5_free_error_message(kdc_context, emsg);
 372     if (state->enc_tkt_reply.authorization_data != NULL)
 373         krb5_free_authdata(kdc_context,
 374                            state->enc_tkt_reply.authorization_data);
 375     if (state->server_keyblock.contents != NULL)
 376         krb5_free_keyblock_contents(kdc_context, &state->server_keyblock);
 377     if (state->client_keyblock.contents != NULL)
 378         krb5_free_keyblock_contents(kdc_context, &state->client_keyblock);
 379     if (state->reply.padata != NULL)
 380         krb5_free_pa_data(kdc_context, state->reply.padata);
 381     if (state->reply_encpart.enc_padata)
 382         krb5_free_pa_data(kdc_context, state->reply_encpart.enc_padata);
 383
 384     if (state->cname != NULL)
 385         free(state->cname);
 386     if (state->sname != NULL)
 387         free(state->sname);
 388     krb5_db_free_principal(kdc_context, state->client);
 389     krb5_db_free_principal(kdc_context, state->server);
 390     if (state->session_key.contents != NULL)
 391         krb5_free_keyblock_contents(kdc_context, &state->session_key);
 392     if (state->ticket_reply.enc_part.ciphertext.data != NULL) {
 393         memset(state->ticket_reply.enc_part.ciphertext.data , 0,
 394                state->ticket_reply.enc_part.ciphertext.length);
 395         free(state->ticket_reply.enc_part.ciphertext.data);
 396     }
 397
 398     krb5_free_pa_data(kdc_context, state->e_data);
 399     kdc_free_rstate(state->rstate);
 400     krb5_free_kdc_req(kdc_context, state->request);
 401     assert(did_log != 0);
 402
 403     free(state);
 404     (*oldrespond)(oldarg, errcode, response);
 405 }
 406
 407 static void
 408 finish_missing_required_preauth(void *arg)
 409 {
 410     struct as_req_state *state = (struct as_req_state *)arg;
 411
 412     finish_process_as_req(state, state->preauth_err);
 413 }
 414
 415 static void
 416 finish_preauth(void *arg, krb5_error_code code)
 417 {
 418     struct as_req_state *state = arg;
 419     krb5_error_code real_code = code;
 420
 421     if (code) {
 422         if (vague_errors)
 423             code = KRB5KRB_ERR_GENERIC;
 424         state->status = "PREAUTH_FAILED";
 425         if (real_code == KRB5KDC_ERR_PREAUTH_FAILED) {
 426             state->preauth_err = code;
 427             get_preauth_hint_list(state->request, &state->rock, &state->e_data,
 428                                   finish_missing_required_preauth, state);
 429             return;
 430         }
 431     } else {
 432         /*
 433          * Final check before handing out ticket: If the client requires
 434          * preauthentication, verify that the proper kind of
 435          * preauthentication was carried out.
 436          */
 437         state->status = missing_required_preauth(state->client, state->server,
 438                                                  &state->enc_tkt_reply);
 439         if (state->status) {
 440             state->preauth_err = KRB5KDC_ERR_PREAUTH_REQUIRED;
 441             get_preauth_hint_list(state->request, &state->rock, &state->e_data,
 442                                   finish_missing_required_preauth, state);
 443             return;
 444         }
 445     }
 446
 447     finish_process_as_req(state, code);
 448 }
 449
 450 /*ARGSUSED*/
 451 void
 452 process_as_req(krb5_kdc_req *request, krb5_data *req_pkt,
 453                const krb5_fulladdr *from, loop_respond_fn respond, void *arg)
 454 {
 455     krb5_error_code errcode;
 456     krb5_timestamp rtime;
 457     unsigned int s_flags = 0;
 458     krb5_principal_data client_princ;
 459     krb5_data encoded_req_body;
 460     krb5_enctype useenctype;
 461     struct as_req_state *state;
 462
 463     state = malloc(sizeof(*state));
 464     if (!state) {
 465         (*respond)(arg, ENOMEM, NULL);
 466         return;
 467     }
 468     state->session_key.contents = 0;
 469     state->enc_tkt_reply.authorization_data = NULL;
 470     state->reply.padata = 0;
 471     memset(&state->reply, 0, sizeof(state->reply));
 472     state->respond = respond;
 473     state->arg = arg;
 474     state->ticket_reply.enc_part.ciphertext.data = 0;
 475     state->server_keyblock.contents = NULL;
 476     state->client_keyblock.contents = NULL;
 477     state->reply_encpart.enc_padata = 0;
 478     state->client = NULL;
 479     state->server = NULL;
 480     state->request = request;
 481     state->e_data = NULL;
 482     state->typed_e_data = FALSE;
 483     state->authtime = 0;
 484     state->c_flags = 0;
 485     state->req_pkt = req_pkt;
 486     state->rstate = NULL;
 487     state->sname = 0;
 488     state->cname = 0;
 489     state->pa_context = NULL;
 490     state->from = from;
 491     memset(&state->rock, 0, sizeof(state->rock));
 492
 493 #if APPLE_PKINIT
 494     asReqDebug("process_as_req top realm %s name %s\n",
 495                request->client->realm.data, request->client->data->data);
 496 #endif /* APPLE_PKINIT */
 497
 498     if (state->request->msg_type != KRB5_AS_REQ) {
 499         state->status = "msg_type mismatch";
 500         errcode = KRB5_BADMSGTYPE;
 501         goto errout;
 502     }
 503     errcode = kdc_make_rstate(&state->rstate);
 504     if (errcode != 0) {
 505         state->status = "constructing state";
 506         goto errout;
 507     }
 508     if (fetch_asn1_field((unsigned char *) req_pkt->data,
 509                          1, 4, &encoded_req_body) != 0) {
 510         errcode = ASN1_BAD_ID;
 511         state->status = "Finding req_body";
 512         goto errout;
 513     }
 514     errcode = kdc_find_fast(&state->request, &encoded_req_body,
 515                             NULL /*TGS key*/, NULL, state->rstate);
 516     if (errcode) {
 517         state->status = "error decoding FAST";
 518         goto errout;
 519     }
 520     state->rock.request = state->request;
 521     state->rock.rstate = state->rstate;
 522     if (!state->request->client) {
 523         state->status = "NULL_CLIENT";
 524         errcode = KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
 525         goto errout;
 526     }
 527     if ((errcode = krb5_unparse_name(kdc_context,
 528                                      state->request->client,
 529                                      &state->cname))) {
 530         state->status = "UNPARSING_CLIENT";
 531         goto errout;
 532     }
 533     limit_string(state->cname);
 534     if (!state->request->server) {
 535         state->status = "NULL_SERVER";
 536         errcode = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
 537         goto errout;
 538     }
 539     if ((errcode = krb5_unparse_name(kdc_context,
 540                                      state->request->server,
 541                                      &state->sname))) {
 542         state->status = "UNPARSING_SERVER";
 543         goto errout;
 544     }
 545     limit_string(state->sname);
 546
 547     /*
 548      * We set KRB5_KDB_FLAG_CLIENT_REFERRALS_ONLY as a hint
 549      * to the backend to return naming information in lieu
 550      * of cross realm TGS entries.
 551      */
 552     setflag(state->c_flags, KRB5_KDB_FLAG_CLIENT_REFERRALS_ONLY);
 553     /*
 554      * Note that according to the referrals draft we should
 555      * always canonicalize enterprise principal names.
 556      */
 557     if (isflagset(state->request->kdc_options, KDC_OPT_CANONICALIZE) ||
 558         state->request->client->type == KRB5_NT_ENTERPRISE_PRINCIPAL) {
 559         setflag(state->c_flags, KRB5_KDB_FLAG_CANONICALIZE);
 560         setflag(state->c_flags, KRB5_KDB_FLAG_ALIAS_OK);
 561     }
 562     if (include_pac_p(kdc_context, state->request)) {
 563         setflag(state->c_flags, KRB5_KDB_FLAG_INCLUDE_PAC);
 564     }
 565     errcode = krb5_db_get_principal(kdc_context, state->request->client,
 566                                     state->c_flags, &state->client);
 567     if (errcode == KRB5_KDB_NOENTRY) {
 568         state->status = "CLIENT_NOT_FOUND";
 569         if (vague_errors)
 570             errcode = KRB5KRB_ERR_GENERIC;
 571         else
 572             errcode = KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
 573         goto errout;
 574     } else if (errcode) {
 575         state->status = "LOOKING_UP_CLIENT";
 576         goto errout;
 577     }
 578     state->rock.client = state->client;
 579
 580     /*
 581      * If the backend returned a principal that is not in the local
 582      * realm, then we need to refer the client to that realm.
 583      */
 584     if (!is_local_principal(state->client->princ)) {
 585         /* Entry is a referral to another realm */
 586         state->status = "REFERRAL";
 587         errcode = KRB5KDC_ERR_WRONG_REALM;
 588         goto errout;
 589     }
 590
 591 #if 0
 592     /*
 593      * Turn off canonicalization if client is marked DES only
 594      * (unless enterprise principal name was requested)
 595      */
 596     if (isflagset(client->attributes, KRB5_KDB_NON_MS_PRINCIPAL) &&
 597         krb5_princ_type(kdc_context,
 598                         request->client) != KRB5_NT_ENTERPRISE_PRINCIPAL) {
 599         clear(c_flags, KRB5_KDB_FLAG_CANONICALIZE);
 600     }
 601 #endif
 602
 603     s_flags = 0;
 604     setflag(s_flags, KRB5_KDB_FLAG_ALIAS_OK);
 605     if (isflagset(state->request->kdc_options, KDC_OPT_CANONICALIZE)) {
 606         setflag(s_flags, KRB5_KDB_FLAG_CANONICALIZE);
 607     }
 608     errcode = krb5_db_get_principal(kdc_context, state->request->server,
 609                                     s_flags, &state->server);
 610     if (errcode == KRB5_KDB_NOENTRY) {
 611         state->status = "SERVER_NOT_FOUND";
 612         errcode = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
 613         goto errout;
 614     } else if (errcode) {
 615         state->status = "LOOKING_UP_SERVER";
 616         goto errout;
 617     }
 618
 619     if ((errcode = krb5_timeofday(kdc_context, &state->kdc_time))) {
 620         state->status = "TIMEOFDAY";
 621         goto errout;
 622     }
 623     state->authtime = state->kdc_time; /* for audit_as_request() */
 624
 625     if ((errcode = validate_as_request(state->request, *state->client,
 626                                        *state->server, state->kdc_time,
 627                                        &state->status, &state->e_data))) {
 628         if (!state->status)
 629             state->status = "UNKNOWN_REASON";
 630         errcode += ERROR_TABLE_BASE_krb5;
 631         goto errout;
 632     }
 633
 634     /*
 635      * Select the keytype for the ticket session key.
 636      */
 637     if ((useenctype = select_session_keytype(kdc_context, state->server,
 638                                              state->request->nktypes,
 639                                              state->request->ktype)) == 0) {
 640         /* unsupported ktype */
 641         state->status = "BAD_ENCRYPTION_TYPE";
 642         errcode = KRB5KDC_ERR_ETYPE_NOSUPP;
 643         goto errout;
 644     }
 645
 646     if ((errcode = krb5_c_make_random_key(kdc_context, useenctype,
 647                                           &state->session_key))) {
 648         state->status = "RANDOM_KEY_FAILED";
 649         goto errout;
 650     }
 651
 652     /*
 653      * Canonicalization is only effective if we are issuing a TGT
 654      * (the intention is to allow support for Windows "short" realm
 655      * aliases, nothing more).
 656      */
 657     if (isflagset(s_flags, KRB5_KDB_FLAG_CANONICALIZE) &&
 658         krb5_is_tgs_principal(state->request->server) &&
 659         krb5_is_tgs_principal(state->server->princ)) {
 660         state->ticket_reply.server = state->server->princ;
 661     } else {
 662         state->ticket_reply.server = state->request->server;
 663     }
 664
 665     state->enc_tkt_reply.flags = 0;
 666     state->enc_tkt_reply.times.authtime = state->authtime;
 667
 668     setflag(state->enc_tkt_reply.flags, TKT_FLG_INITIAL);
 669     setflag(state->enc_tkt_reply.flags, TKT_FLG_ENC_PA_REP);
 670
 671     /*
 672      * It should be noted that local policy may affect the
 673      * processing of any of these flags.  For example, some
 674      * realms may refuse to issue renewable tickets
 675      */
 676
 677     if (isflagset(state->request->kdc_options, KDC_OPT_FORWARDABLE))
 678         setflag(state->enc_tkt_reply.flags, TKT_FLG_FORWARDABLE);
 679
 680     if (isflagset(state->request->kdc_options, KDC_OPT_PROXIABLE))
 681         setflag(state->enc_tkt_reply.flags, TKT_FLG_PROXIABLE);
 682
 683     if (isflagset(state->request->kdc_options, KDC_OPT_ALLOW_POSTDATE))
 684         setflag(state->enc_tkt_reply.flags, TKT_FLG_MAY_POSTDATE);
 685
 686     state->enc_tkt_reply.session = &state->session_key;
 687     if (isflagset(state->c_flags, KRB5_KDB_FLAG_CANONICALIZE)) {
 688         client_princ = *(state->client->princ);
 689     } else {
 690         client_princ = *(state->request->client);
 691         /* The realm is always canonicalized */
 692         client_princ.realm = state->client->princ->realm;
 693     }
 694     state->enc_tkt_reply.client = &client_princ;
 695     state->enc_tkt_reply.transited.tr_type = KRB5_DOMAIN_X500_COMPRESS;
 696     state->enc_tkt_reply.transited.tr_contents = empty_string;
 697
 698     if (isflagset(state->request->kdc_options, KDC_OPT_POSTDATED)) {
 699         setflag(state->enc_tkt_reply.flags, TKT_FLG_POSTDATED);
 700         setflag(state->enc_tkt_reply.flags, TKT_FLG_INVALID);
 701         state->enc_tkt_reply.times.starttime = state->request->from;
 702     } else
 703         state->enc_tkt_reply.times.starttime = state->kdc_time;
 704
 705     kdc_get_ticket_endtime(kdc_context, state->enc_tkt_reply.times.starttime,
 706                            kdc_infinity, state->request->till, state->client,
 707                            state->server, &state->enc_tkt_reply.times.endtime);
 708
 709     if (isflagset(state->request->kdc_options, KDC_OPT_RENEWABLE_OK) &&
 710         !isflagset(state->client->attributes, KRB5_KDB_DISALLOW_RENEWABLE) &&
 711         (state->enc_tkt_reply.times.endtime < state->request->till)) {
 712
 713         /* we set the RENEWABLE option for later processing */
 714
 715         setflag(state->request->kdc_options, KDC_OPT_RENEWABLE);
 716         state->request->rtime = state->request->till;
 717     }
 718     rtime = (state->request->rtime == 0) ? kdc_infinity :
 719         state->request->rtime;
 720
 721     if (isflagset(state->request->kdc_options, KDC_OPT_RENEWABLE)) {
 722         /*
 723          * XXX Should we squelch the output renew_till to be no
 724          * earlier than the endtime of the ticket?
 725          */
 726         setflag(state->enc_tkt_reply.flags, TKT_FLG_RENEWABLE);
 727         state->enc_tkt_reply.times.renew_till =
 728             min(rtime, state->enc_tkt_reply.times.starttime +
 729                 min(state->client->max_renewable_life,
 730                     min(state->server->max_renewable_life,
 731                         max_renewable_life_for_realm)));
 732     } else
 733         state->enc_tkt_reply.times.renew_till = 0; /* XXX */
 734
 735     /*
 736      * starttime is optional, and treated as authtime if not present.
 737      * so we can nuke it if it matches
 738      */
 739     if (state->enc_tkt_reply.times.starttime ==
 740         state->enc_tkt_reply.times.authtime)
 741         state->enc_tkt_reply.times.starttime = 0;
 742
 743     state->enc_tkt_reply.caddrs = state->request->addresses;
 744     state->enc_tkt_reply.authorization_data = 0;
 745
 746     /* If anonymous requests are being used, adjust the realm of the client
 747      * principal. */
 748     if (isflagset(state->request->kdc_options, KDC_OPT_REQUEST_ANONYMOUS)) {
 749         if (!krb5_principal_compare_any_realm(kdc_context,
 750                                               state->request->client,
 751                                               krb5_anonymous_principal())) {
 752             errcode = KRB5KDC_ERR_BADOPTION;
 753             state->status = "Anonymous requested but anonymous "
 754                 "principal not used.";
 755             goto errout;
 756         }
 757         setflag(state->enc_tkt_reply.flags, TKT_FLG_ANONYMOUS);
 758         krb5_free_principal(kdc_context, state->request->client);
 759         errcode = krb5_copy_principal(kdc_context, krb5_anonymous_principal(),
 760                                       &state->request->client);
 761         if (errcode) {
 762             state->status = "Copying anonymous principal";
 763             goto errout;
 764         }
 765         state->enc_tkt_reply.client = state->request->client;
 766         setflag(state->client->attributes, KRB5_KDB_REQUIRES_PRE_AUTH);
 767     }
 768
 769     /*
 770      * Check the preauthentication if it is there.
 771      */
 772     if (state->request->padata) {
 773         check_padata(kdc_context, &state->rock, state->req_pkt,
 774                      state->request, &state->enc_tkt_reply, &state->pa_context,
 775                      &state->e_data, &state->typed_e_data, finish_preauth,
 776                      state);
 777     } else
 778         finish_preauth(state, 0);
 779     return;
 780
 781 errout:
 782     finish_process_as_req(state, errcode);
 783 }
 784
 785 static krb5_error_code
 786 prepare_error_as (struct kdc_request_state *rstate, krb5_kdc_req *request,
 787                   int error, krb5_pa_data **e_data, krb5_boolean typed_e_data,
 788                   krb5_principal canon_client, krb5_data **response,
 789                   const char *status)
 790 {
 791     krb5_error errpkt;
 792     krb5_error_code retval;
 793     krb5_data *scratch = NULL, *e_data_asn1 = NULL, *fast_edata = NULL;
 794
 795     errpkt.ctime = request->nonce;
 796     errpkt.cusec = 0;
 797
 798     retval = krb5_us_timeofday(kdc_context, &errpkt.stime, &errpkt.susec);
 799     if (retval)
 800         return retval;
 801     errpkt.error = error;
 802     errpkt.server = request->server;
 803     errpkt.client = (error == KRB5KDC_ERR_WRONG_REALM) ? canon_client :
 804         request->client;
 805     errpkt.text = string2data((char *)status);
 806
 807     if (e_data != NULL) {
 808         if (typed_e_data) {
 809             retval = encode_krb5_typed_data((const krb5_typed_data **)e_data,
 810                                             &e_data_asn1);
 811         } else
 812             retval = encode_krb5_padata_sequence(e_data, &e_data_asn1);
 813         if (retval)
 814             goto cleanup;
 815         errpkt.e_data = *e_data_asn1;
 816     } else
 817         errpkt.e_data = empty_data();
 818
 819     retval = kdc_fast_handle_error(kdc_context, rstate, request, e_data,
 820                                    &errpkt, &fast_edata);
 821     if (retval)
 822         goto cleanup;
 823     if (fast_edata != NULL)
 824         errpkt.e_data = *fast_edata;
 825
 826     scratch = k5alloc(sizeof(*scratch), &retval);
 827     if (scratch == NULL)
 828         goto cleanup;
 829     retval = krb5_mk_error(kdc_context, &errpkt, scratch);
 830     if (retval)
 831         goto cleanup;
 832
 833     *response = scratch;
 834     scratch = NULL;
 835
 836 cleanup:
 837     krb5_free_data(kdc_context, fast_edata);
 838     krb5_free_data(kdc_context, e_data_asn1);
 839     free(scratch);
 840     return retval;
 841 }