source/heimdal/kdc/kerberos4.c

   1 /*
   2  * Copyright (c) 1997 - 2005 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "kdc_locl.h"
  35
  36 #include <krb5-v4compat.h>
  37
  38 RCSID("$Id: kerberos4.c,v 1.60 2006/05/05 10:50:44 lha Exp $");
  39
  40 #ifndef swap32
  41 static uint32_t
  42 swap32(uint32_t x)
  43 {
  44     return ((x << 24) & 0xff000000) |
  45         ((x << 8) & 0xff0000) |
  46         ((x >> 8) & 0xff00) |
  47         ((x >> 24) & 0xff);
  48 }
  49 #endif /* swap32 */
  50
  51 int
  52 _kdc_maybe_version4(unsigned char *buf, int len)
  53 {
  54     return len > 0 && *buf == 4;
  55 }
  56
  57 static void
  58 make_err_reply(krb5_context context, krb5_data *reply,
  59                int code, const char *msg)
  60 {
  61     _krb5_krb_cr_err_reply(context, "", "", "",
  62                            kdc_time, code, msg, reply);
  63 }
  64
  65 struct valid_princ_ctx {
  66     krb5_kdc_configuration *config;
  67     unsigned flags;
  68 };
  69
  70 static krb5_boolean
  71 valid_princ(krb5_context context,
  72             void *funcctx,
  73             krb5_principal princ)
  74 {
  75     struct valid_princ_ctx *ctx = funcctx;
  76     krb5_error_code ret;
  77     char *s;
  78     hdb_entry_ex *ent;
  79
  80     ret = krb5_unparse_name(context, princ, &s);
  81     if (ret)
  82         return FALSE;
  83     ret = _kdc_db_fetch(context, ctx->config, princ, ctx->flags, &ent);
  84     if (ret) {
  85         kdc_log(context, ctx->config, 7, "Lookup %s failed: %s", s,
  86                 krb5_get_err_text (context, ret));
  87         free(s);
  88         return FALSE;
  89     }
  90     kdc_log(context, ctx->config, 7, "Lookup %s succeeded", s);
  91     free(s);
  92     _kdc_free_ent(context, ent);
  93     return TRUE;
  94 }
  95
  96 krb5_error_code
  97 _kdc_db_fetch4(krb5_context context,
  98                krb5_kdc_configuration *config,
  99                const char *name, const char *instance, const char *realm,
 100                unsigned flags,
 101                hdb_entry_ex **ent)
 102 {
 103     krb5_principal p;
 104     krb5_error_code ret;
 105     struct valid_princ_ctx ctx;
 106
 107     ctx.config = config;
 108     ctx.flags = flags;
 109
 110     ret = krb5_425_conv_principal_ext2(context, name, instance, realm,
 111                                        valid_princ, &ctx, 0, &p);
 112     if(ret)
 113         return ret;
 114     ret = _kdc_db_fetch(context, config, p, flags, ent);
 115     krb5_free_principal(context, p);
 116     return ret;
 117 }
 118
 119 #define RCHECK(X, L) if(X){make_err_reply(context, reply, KFAILURE, "Packet too short"); goto L;}
 120
 121 /*
 122  * Process the v4 request in `buf, len' (received from `addr'
 123  * (with string `from').
 124  * Return an error code and a reply in `reply'.
 125  */
 126
 127 krb5_error_code
 128 _kdc_do_version4(krb5_context context,
 129                  krb5_kdc_configuration *config,
 130                  unsigned char *buf,
 131                  size_t len,
 132                  krb5_data *reply,
 133                  const char *from,
 134                  struct sockaddr_in *addr)
 135 {
 136     krb5_storage *sp;
 137     krb5_error_code ret;
 138     hdb_entry_ex *client = NULL, *server = NULL;
 139     Key *ckey, *skey;
 140     int8_t pvno;
 141     int8_t msg_type;
 142     int lsb;
 143     char *name = NULL, *inst = NULL, *realm = NULL;
 144     char *sname = NULL, *sinst = NULL;
 145     int32_t req_time;
 146     time_t max_life;
 147     uint8_t life;
 148     char client_name[256];
 149     char server_name[256];
 150
 151     if(!config->enable_v4) {
 152         kdc_log(context, config, 0,
 153                 "Rejected version 4 request from %s", from);
 154         make_err_reply(context, reply, KDC_GEN_ERR, "function not enabled");
 155         return 0;
 156     }
 157
 158     sp = krb5_storage_from_mem(buf, len);
 159     RCHECK(krb5_ret_int8(sp, &pvno), out);
 160     if(pvno != 4){
 161         kdc_log(context, config, 0,
 162                 "Protocol version mismatch (krb4) (%d)", pvno);
 163         make_err_reply(context, reply, KDC_PKT_VER, "protocol mismatch");
 164         goto out;
 165     }
 166     RCHECK(krb5_ret_int8(sp, &msg_type), out);
 167     lsb = msg_type & 1;
 168     msg_type &= ~1;
 169     switch(msg_type){
 170     case AUTH_MSG_KDC_REQUEST: {
 171         krb5_data ticket, cipher;
 172         krb5_keyblock session;
 173
 174         krb5_data_zero(&ticket);
 175         krb5_data_zero(&cipher);
 176
 177         RCHECK(krb5_ret_stringz(sp, &name), out1);
 178         RCHECK(krb5_ret_stringz(sp, &inst), out1);
 179         RCHECK(krb5_ret_stringz(sp, &realm), out1);
 180         RCHECK(krb5_ret_int32(sp, &req_time), out1);
 181         if(lsb)
 182             req_time = swap32(req_time);
 183         RCHECK(krb5_ret_uint8(sp, &life), out1);
 184         RCHECK(krb5_ret_stringz(sp, &sname), out1);
 185         RCHECK(krb5_ret_stringz(sp, &sinst), out1);
 186         snprintf (client_name, sizeof(client_name),
 187                   "%s.%s@%s", name, inst, realm);
 188         snprintf (server_name, sizeof(server_name),
 189                   "%s.%s@%s", sname, sinst, config->v4_realm);
 190
 191         kdc_log(context, config, 0, "AS-REQ (krb4) %s from %s for %s",
 192                 client_name, from, server_name);
 193
 194         ret = _kdc_db_fetch4(context, config, name, inst, realm,
 195                              HDB_F_GET_CLIENT, &client);
 196         if(ret) {
 197             kdc_log(context, config, 0, "Client not found in database: %s: %s",
 198                     client_name, krb5_get_err_text(context, ret));
 199             make_err_reply(context, reply, KERB_ERR_PRINCIPAL_UNKNOWN,
 200                            "principal unknown");
 201             goto out1;
 202         }
 203         ret = _kdc_db_fetch4(context, config, sname, sinst, config->v4_realm,
 204                              HDB_F_GET_SERVER, &server);
 205         if(ret){
 206             kdc_log(context, config, 0, "Server not found in database: %s: %s",
 207                     server_name, krb5_get_err_text(context, ret));
 208             make_err_reply(context, reply, KERB_ERR_PRINCIPAL_UNKNOWN,
 209                            "principal unknown");
 210             goto out1;
 211         }
 212
 213         ret = _kdc_check_flags (context, config,
 214                                 client, client_name,
 215                                 server, server_name,
 216                                 TRUE);
 217         if (ret) {
 218             /* good error code? */
 219             make_err_reply(context, reply, KERB_ERR_NAME_EXP,
 220                            "operation not allowed");
 221             goto out1;
 222         }
 223
 224         /*
 225          * There's no way to do pre-authentication in v4 and thus no
 226          * good error code to return if preauthentication is required.
 227          */
 228
 229         if (config->require_preauth
 230             || client->entry.flags.require_preauth
 231             || server->entry.flags.require_preauth) {
 232             kdc_log(context, config, 0,
 233                     "Pre-authentication required for v4-request: "
 234                     "%s for %s",
 235                     client_name, server_name);
 236             make_err_reply(context, reply, KERB_ERR_NULL_KEY,
 237                            "preauth required");
 238             goto out1;
 239         }
 240
 241         ret = _kdc_get_des_key(context, client, FALSE, FALSE, &ckey);
 242         if(ret){
 243             kdc_log(context, config, 0, "no suitable DES key for client");
 244             make_err_reply(context, reply, KDC_NULL_KEY,
 245                            "no suitable DES key for client");
 246             goto out1;
 247         }
 248
 249 #if 0
 250         /* this is not necessary with the new code in libkrb */
 251         /* find a properly salted key */
 252         while(ckey->salt == NULL || ckey->salt->salt.length != 0)
 253             ret = hdb_next_keytype2key(context, &client->entry, KEYTYPE_DES, &ckey);
 254         if(ret){
 255             kdc_log(context, config, 0, "No version-4 salted key in database -- %s.%s@%s",
 256                     name, inst, realm);
 257             make_err_reply(context, reply, KDC_NULL_KEY,
 258                            "No version-4 salted key in database");
 259             goto out1;
 260         }
 261 #endif
 262
 263         ret = _kdc_get_des_key(context, server, TRUE, FALSE, &skey);
 264         if(ret){
 265             kdc_log(context, config, 0, "no suitable DES key for server");
 266             /* XXX */
 267             make_err_reply(context, reply, KDC_NULL_KEY,
 268                            "no suitable DES key for server");
 269             goto out1;
 270         }
 271
 272         max_life = _krb5_krb_life_to_time(0, life);
 273         if(client->entry.max_life)
 274             max_life = min(max_life, *client->entry.max_life);
 275         if(server->entry.max_life)
 276             max_life = min(max_life, *server->entry.max_life);
 277
 278         life = krb_time_to_life(kdc_time, kdc_time + max_life);
 279
 280         ret = krb5_generate_random_keyblock(context,
 281                                             ETYPE_DES_PCBC_NONE,
 282                                             &session);
 283         if (ret) {
 284             make_err_reply(context, reply, KFAILURE,
 285                            "Not enough random i KDC");
 286             goto out1;
 287         }
 288
 289         ret = _krb5_krb_create_ticket(context,
 290                                       0,
 291                                       name,
 292                                       inst,
 293                                       config->v4_realm,
 294                                       addr->sin_addr.s_addr,
 295                                       &session,
 296                                       life,
 297                                       kdc_time,
 298                                       sname,
 299                                       sinst,
 300                                       &skey->key,
 301                                       &ticket);
 302         if (ret) {
 303             krb5_free_keyblock_contents(context, &session);
 304             make_err_reply(context, reply, KFAILURE,
 305                            "failed to create v4 ticket");
 306             goto out1;
 307         }
 308
 309         ret = _krb5_krb_create_ciph(context,
 310                                     &session,
 311                                     sname,
 312                                     sinst,
 313                                     config->v4_realm,
 314                                     life,
 315                                     server->entry.kvno % 255,
 316                                     &ticket,
 317                                     kdc_time,
 318                                     &ckey->key,
 319                                     &cipher);
 320         krb5_free_keyblock_contents(context, &session);
 321         krb5_data_free(&ticket);
 322         if (ret) {
 323             make_err_reply(context, reply, KFAILURE,
 324                            "Failed to create v4 cipher");
 325             goto out1;
 326         }
 327
 328         ret = _krb5_krb_create_auth_reply(context,
 329                                           name,
 330                                           inst,
 331                                           realm,
 332                                           req_time,
 333                                           0,
 334                                           client->entry.pw_end ? *client->entry.pw_end : 0,
 335                                           client->entry.kvno % 256,
 336                                           &cipher,
 337                                           reply);
 338         krb5_data_free(&cipher);
 339
 340     out1:
 341         break;
 342     }
 343     case AUTH_MSG_APPL_REQUEST: {
 344         struct _krb5_krb_auth_data ad;
 345         int8_t kvno;
 346         int8_t ticket_len;
 347         int8_t req_len;
 348         krb5_data auth;
 349         int32_t address;
 350         size_t pos;
 351         krb5_principal tgt_princ = NULL;
 352         hdb_entry_ex *tgt = NULL;
 353         Key *tkey;
 354         time_t max_end, actual_end, issue_time;
 355
 356         memset(&ad, 0, sizeof(ad));
 357         krb5_data_zero(&auth);
 358
 359         RCHECK(krb5_ret_int8(sp, &kvno), out2);
 360         RCHECK(krb5_ret_stringz(sp, &realm), out2);
 361
 362         ret = krb5_425_conv_principal(context, "krbtgt", realm,
 363                                       config->v4_realm,
 364                                       &tgt_princ);
 365         if(ret){
 366             kdc_log(context, config, 0,
 367                     "Converting krbtgt principal (krb4): %s",
 368                     krb5_get_err_text(context, ret));
 369             make_err_reply(context, reply, KFAILURE,
 370                            "Failed to convert v4 principal (krbtgt)");
 371             goto out2;
 372         }
 373
 374         ret = _kdc_db_fetch(context, config, tgt_princ,
 375                             HDB_F_GET_KRBTGT, &tgt);
 376         if(ret){
 377             char *s;
 378             s = kdc_log_msg(context, config, 0, "Ticket-granting ticket not "
 379                             "found in database (krb4): krbtgt.%s@%s: %s",
 380                             realm, config->v4_realm,
 381                             krb5_get_err_text(context, ret));
 382             make_err_reply(context, reply, KFAILURE, s);
 383             free(s);
 384             goto out2;
 385         }
 386
 387         if(tgt->entry.kvno % 256 != kvno){
 388             kdc_log(context, config, 0,
 389                     "tgs-req (krb4) with old kvno %d (current %d) for "
 390                     "krbtgt.%s@%s", kvno, tgt->entry.kvno % 256,
 391                     realm, config->v4_realm);
 392             make_err_reply(context, reply, KDC_AUTH_EXP,
 393                            "old krbtgt kvno used");
 394             goto out2;
 395         }
 396
 397         ret = _kdc_get_des_key(context, tgt, TRUE, FALSE, &tkey);
 398         if(ret){
 399             kdc_log(context, config, 0,
 400                     "no suitable DES key for krbtgt (krb4)");
 401             /* XXX */
 402             make_err_reply(context, reply, KDC_NULL_KEY,
 403                            "no suitable DES key for krbtgt");
 404             goto out2;
 405         }
 406
 407         RCHECK(krb5_ret_int8(sp, &ticket_len), out2);
 408         RCHECK(krb5_ret_int8(sp, &req_len), out2);
 409
 410         pos = krb5_storage_seek(sp, ticket_len + req_len, SEEK_CUR);
 411
 412         auth.data = buf;
 413         auth.length = pos;
 414
 415         if (config->check_ticket_addresses)
 416             address = addr->sin_addr.s_addr;
 417         else
 418             address = 0;
 419
 420         ret = _krb5_krb_rd_req(context, &auth, "krbtgt", realm,
 421                                config->v4_realm,
 422                                address, &tkey->key, &ad);
 423         if(ret){
 424             kdc_log(context, config, 0, "krb_rd_req: %d", ret);
 425             make_err_reply(context, reply, ret, "failed to parse request");
 426             goto out2;
 427         }
 428
 429         RCHECK(krb5_ret_int32(sp, &req_time), out2);
 430         if(lsb)
 431             req_time = swap32(req_time);
 432         RCHECK(krb5_ret_uint8(sp, &life), out2);
 433         RCHECK(krb5_ret_stringz(sp, &sname), out2);
 434         RCHECK(krb5_ret_stringz(sp, &sinst), out2);
 435         snprintf (server_name, sizeof(server_name),
 436                   "%s.%s@%s",
 437                   sname, sinst, config->v4_realm);
 438         snprintf (client_name, sizeof(client_name),
 439                   "%s.%s@%s",
 440                   ad.pname, ad.pinst, ad.prealm);
 441
 442         kdc_log(context, config, 0, "TGS-REQ (krb4) %s from %s for %s",
 443                 client_name, from, server_name);
 444
 445         if(strcmp(ad.prealm, realm)){
 446             kdc_log(context, config, 0,
 447                     "Can't hop realms (krb4) %s -> %s", realm, ad.prealm);
 448             make_err_reply(context, reply, KERB_ERR_PRINCIPAL_UNKNOWN,
 449                            "Can't hop realms");
 450             goto out2;
 451         }
 452
 453         if (!config->enable_v4_cross_realm && strcmp(realm, config->v4_realm) != 0) {
 454             kdc_log(context, config, 0,
 455                     "krb4 Cross-realm %s -> %s disabled",
 456                     realm, config->v4_realm);
 457             make_err_reply(context, reply, KERB_ERR_PRINCIPAL_UNKNOWN,
 458                            "Can't hop realms");
 459             goto out2;
 460         }
 461
 462         if(strcmp(sname, "changepw") == 0){
 463             kdc_log(context, config, 0,
 464                     "Bad request for changepw ticket (krb4)");
 465             make_err_reply(context, reply, KERB_ERR_PRINCIPAL_UNKNOWN,
 466                            "Can't authorize password change based on TGT");
 467             goto out2;
 468         }
 469
 470         ret = _kdc_db_fetch4(context, config, ad.pname, ad.pinst, ad.prealm,
 471                              HDB_F_GET_CLIENT, &client);
 472         if(ret && ret != HDB_ERR_NOENTRY) {
 473             char *s;
 474             s = kdc_log_msg(context, config, 0,
 475                             "Client not found in database: (krb4) %s: %s",
 476                             client_name, krb5_get_err_text(context, ret));
 477             make_err_reply(context, reply, KERB_ERR_PRINCIPAL_UNKNOWN, s);
 478             free(s);
 479             goto out2;
 480         }
 481         if (client == NULL && strcmp(ad.prealm, config->v4_realm) == 0) {
 482             char *s;
 483             s = kdc_log_msg(context, config, 0,
 484                             "Local client not found in database: (krb4) "
 485                             "%s", client_name);
 486             make_err_reply(context, reply, KERB_ERR_PRINCIPAL_UNKNOWN, s);
 487             free(s);
 488             goto out2;
 489         }
 490
 491         ret = _kdc_db_fetch4(context, config, sname, sinst, config->v4_realm,
 492                              HDB_F_GET_SERVER, &server);
 493         if(ret){
 494             char *s;
 495             s = kdc_log_msg(context, config, 0,
 496                             "Server not found in database (krb4): %s: %s",
 497                             server_name, krb5_get_err_text(context, ret));
 498             make_err_reply(context, reply, KERB_ERR_PRINCIPAL_UNKNOWN, s);
 499             free(s);
 500             goto out2;
 501         }
 502
 503         ret = _kdc_check_flags (context, config,
 504                                 client, client_name,
 505                                 server, server_name,
 506                                 FALSE);
 507         if (ret) {
 508             /* good error code? */
 509             make_err_reply(context, reply, KERB_ERR_NAME_EXP,
 510                            "operation not allowed");
 511             goto out2;
 512         }
 513
 514         ret = _kdc_get_des_key(context, server, TRUE, FALSE, &skey);
 515         if(ret){
 516             kdc_log(context, config, 0,
 517                     "no suitable DES key for server (krb4)");
 518             /* XXX */
 519             make_err_reply(context, reply, KDC_NULL_KEY,
 520                            "no suitable DES key for server");
 521             goto out2;
 522         }
 523
 524         max_end = _krb5_krb_life_to_time(ad.time_sec, ad.life);
 525         max_end = min(max_end, _krb5_krb_life_to_time(kdc_time, life));
 526         if(server->entry.max_life)
 527             max_end = min(max_end, kdc_time + *server->entry.max_life);
 528         if(client && client->entry.max_life)
 529             max_end = min(max_end, kdc_time + *client->entry.max_life);
 530         life = min(life, krb_time_to_life(kdc_time, max_end));
 531
 532         issue_time = kdc_time;
 533         actual_end = _krb5_krb_life_to_time(issue_time, life);
 534         while (actual_end > max_end && life > 1) {
 535             /* move them into the next earlier lifetime bracket */
 536             life--;
 537             actual_end = _krb5_krb_life_to_time(issue_time, life);
 538         }
 539         if (actual_end > max_end) {
 540             /* if life <= 1 and it's still too long, backdate the ticket */
 541             issue_time -= actual_end - max_end;
 542         }
 543
 544         {
 545             krb5_data ticket, cipher;
 546             krb5_keyblock session;
 547
 548             krb5_data_zero(&ticket);
 549             krb5_data_zero(&cipher);
 550
 551             ret = krb5_generate_random_keyblock(context,
 552                                                 ETYPE_DES_PCBC_NONE,
 553                                                 &session);
 554             if (ret) {
 555                 make_err_reply(context, reply, KFAILURE,
 556                                "Not enough random i KDC");
 557                 goto out2;
 558             }
 559
 560             ret = _krb5_krb_create_ticket(context,
 561                                           0,
 562                                           ad.pname,
 563                                           ad.pinst,
 564                                           ad.prealm,
 565                                           addr->sin_addr.s_addr,
 566                                           &session,
 567                                           life,
 568                                           issue_time,
 569                                           sname,
 570                                           sinst,
 571                                           &skey->key,
 572                                           &ticket);
 573             if (ret) {
 574                 krb5_free_keyblock_contents(context, &session);
 575                 make_err_reply(context, reply, KFAILURE,
 576                                "failed to create v4 ticket");
 577                 goto out2;
 578             }
 579
 580             ret = _krb5_krb_create_ciph(context,
 581                                         &session,
 582                                         sname,
 583                                         sinst,
 584                                         config->v4_realm,
 585                                         life,
 586                                         server->entry.kvno % 255,
 587                                         &ticket,
 588                                         issue_time,
 589                                         &ad.session,
 590                                         &cipher);
 591             krb5_free_keyblock_contents(context, &session);
 592             if (ret) {
 593                 make_err_reply(context, reply, KFAILURE,
 594                                "failed to create v4 cipher");
 595                 goto out2;
 596             }
 597
 598             ret = _krb5_krb_create_auth_reply(context,
 599                                               ad.pname,
 600                                               ad.pinst,
 601                                               ad.prealm,
 602                                               req_time,
 603                                               0,
 604                                               0,
 605                                               0,
 606                                               &cipher,
 607                                               reply);
 608             krb5_data_free(&cipher);
 609         }
 610     out2:
 611         _krb5_krb_free_auth_data(context, &ad);
 612         if(tgt_princ)
 613             krb5_free_principal(context, tgt_princ);
 614         if(tgt)
 615             _kdc_free_ent(context, tgt);
 616         break;
 617     }
 618     case AUTH_MSG_ERR_REPLY:
 619         break;
 620     default:
 621         kdc_log(context, config, 0, "Unknown message type (krb4): %d from %s",
 622                 msg_type, from);
 623
 624         make_err_reply(context, reply, KFAILURE, "Unknown message type");
 625     }
 626  out:
 627     if(name)
 628         free(name);
 629     if(inst)
 630         free(inst);
 631     if(realm)
 632         free(realm);
 633     if(sname)
 634         free(sname);
 635     if(sinst)
 636         free(sinst);
 637     if(client)
 638         _kdc_free_ent(context, client);
 639     if(server)
 640         _kdc_free_ent(context, server);
 641     krb5_storage_free(sp);
 642     return 0;
 643 }
 644
 645 krb5_error_code
 646 _kdc_encode_v4_ticket(krb5_context context,
 647                       krb5_kdc_configuration *config,
 648                       void *buf, size_t len, const EncTicketPart *et,
 649                       const PrincipalName *service, size_t *size)
 650 {
 651     krb5_storage *sp;
 652     krb5_error_code ret;
 653     char name[40], inst[40], realm[40];
 654     char sname[40], sinst[40];
 655
 656     {
 657         krb5_principal princ;
 658         _krb5_principalname2krb5_principal(context,
 659                                            &princ,
 660                                            *service,
 661                                            et->crealm);
 662         ret = krb5_524_conv_principal(context,
 663                                       princ,
 664                                       sname,
 665                                       sinst,
 666                                       realm);
 667         krb5_free_principal(context, princ);
 668         if(ret)
 669             return ret;
 670
 671         _krb5_principalname2krb5_principal(context,
 672                                            &princ,
 673                                            et->cname,
 674                                            et->crealm);
 675
 676         ret = krb5_524_conv_principal(context,
 677                                       princ,
 678                                       name,
 679                                       inst,
 680                                       realm);
 681         krb5_free_principal(context, princ);
 682     }
 683     if(ret)
 684         return ret;
 685
 686     sp = krb5_storage_emem();
 687
 688     krb5_store_int8(sp, 0); /* flags */
 689     krb5_store_stringz(sp, name);
 690     krb5_store_stringz(sp, inst);
 691     krb5_store_stringz(sp, realm);
 692     {
 693         unsigned char tmp[4] = { 0, 0, 0, 0 };
 694         int i;
 695         if(et->caddr){
 696             for(i = 0; i < et->caddr->len; i++)
 697                 if(et->caddr->val[i].addr_type == AF_INET &&
 698                    et->caddr->val[i].address.length == 4){
 699                     memcpy(tmp, et->caddr->val[i].address.data, 4);
 700                     break;
 701                 }
 702         }
 703         krb5_storage_write(sp, tmp, sizeof(tmp));
 704     }
 705
 706     if((et->key.keytype != ETYPE_DES_CBC_MD5 &&
 707         et->key.keytype != ETYPE_DES_CBC_MD4 &&
 708         et->key.keytype != ETYPE_DES_CBC_CRC) ||
 709        et->key.keyvalue.length != 8)
 710         return -1;
 711     krb5_storage_write(sp, et->key.keyvalue.data, 8);
 712
 713     {
 714         time_t start = et->starttime ? *et->starttime : et->authtime;
 715         krb5_store_int8(sp, krb_time_to_life(start, et->endtime));
 716         krb5_store_int32(sp, start);
 717     }
 718
 719     krb5_store_stringz(sp, sname);
 720     krb5_store_stringz(sp, sinst);
 721
 722     {
 723         krb5_data data;
 724         krb5_storage_to_data(sp, &data);
 725         krb5_storage_free(sp);
 726         *size = (data.length + 7) & ~7; /* pad to 8 bytes */
 727         if(*size > len)
 728             return -1;
 729         memset((unsigned char*)buf - *size + 1, 0, *size);
 730         memcpy((unsigned char*)buf - *size + 1, data.data, data.length);
 731         krb5_data_free(&data);
 732     }
 733     return 0;
 734 }
 735
 736 krb5_error_code
 737 _kdc_get_des_key(krb5_context context,
 738                  hdb_entry_ex *principal, krb5_boolean is_server,
 739                  krb5_boolean prefer_afs_key, Key **ret_key)
 740 {
 741     Key *v5_key = NULL, *v4_key = NULL, *afs_key = NULL, *server_key = NULL;
 742     int i;
 743     krb5_enctype etypes[] = { ETYPE_DES_CBC_MD5,
 744                               ETYPE_DES_CBC_MD4,
 745                               ETYPE_DES_CBC_CRC };
 746
 747     for(i = 0;
 748         i < sizeof(etypes)/sizeof(etypes[0])
 749             && (v5_key == NULL || v4_key == NULL ||
 750                 afs_key == NULL || server_key == NULL);
 751         ++i) {
 752         Key *key = NULL;
 753         while(hdb_next_enctype2key(context, &principal->entry, etypes[i], &key) == 0) {
 754             if(key->salt == NULL) {
 755                 if(v5_key == NULL)
 756                     v5_key = key;
 757             } else if(key->salt->type == hdb_pw_salt &&
 758                       key->salt->salt.length == 0) {
 759                 if(v4_key == NULL)
 760                     v4_key = key;
 761             } else if(key->salt->type == hdb_afs3_salt) {
 762                 if(afs_key == NULL)
 763                     afs_key = key;
 764             } else if(server_key == NULL)
 765                 server_key = key;
 766         }
 767     }
 768
 769     if(prefer_afs_key) {
 770         if(afs_key)
 771             *ret_key = afs_key;
 772         else if(v4_key)
 773             *ret_key = v4_key;
 774         else if(v5_key)
 775             *ret_key = v5_key;
 776         else if(is_server && server_key)
 777             *ret_key = server_key;
 778         else
 779             return KERB_ERR_NULL_KEY;
 780     } else {
 781         if(v4_key)
 782             *ret_key = v4_key;
 783         else if(afs_key)
 784             *ret_key = afs_key;
 785         else  if(v5_key)
 786             *ret_key = v5_key;
 787         else if(is_server && server_key)
 788             *ret_key = server_key;
 789         else
 790             return KERB_ERR_NULL_KEY;
 791     }
 792
 793     if((*ret_key)->key.keyvalue.length == 0)
 794         return KERB_ERR_NULL_KEY;
 795     return 0;
 796 }
 797