Add a setexpiry operation in samdb.py
[kai/samba.git] / source / heimdal / kdc / kerberos4.c
1 /*
2  * Copyright (c) 1997 - 2006 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 21577 2007-07-16 08:14:06Z lha $");
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, NULL, &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, NULL, 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, KRB4ET_KDC_GEN_ERR,
155                        "Function not enabled");
156         return 0;
157     }
158
159     sp = krb5_storage_from_mem(buf, len);
160     RCHECK(krb5_ret_int8(sp, &pvno), out);
161     if(pvno != 4){
162         kdc_log(context, config, 0,
163                 "Protocol version mismatch (krb4) (%d)", pvno);
164         make_err_reply(context, reply, KRB4ET_KDC_PKT_VER, "protocol mismatch");
165         goto out;
166     }
167     RCHECK(krb5_ret_int8(sp, &msg_type), out);
168     lsb = msg_type & 1;
169     msg_type &= ~1;
170     switch(msg_type){
171     case AUTH_MSG_KDC_REQUEST: {
172         krb5_data ticket, cipher;
173         krb5_keyblock session;
174         
175         krb5_data_zero(&ticket);
176         krb5_data_zero(&cipher);
177
178         RCHECK(krb5_ret_stringz(sp, &name), out1);
179         RCHECK(krb5_ret_stringz(sp, &inst), out1);
180         RCHECK(krb5_ret_stringz(sp, &realm), out1);
181         RCHECK(krb5_ret_int32(sp, &req_time), out1);
182         if(lsb)
183             req_time = swap32(req_time);
184         RCHECK(krb5_ret_uint8(sp, &life), out1);
185         RCHECK(krb5_ret_stringz(sp, &sname), out1);
186         RCHECK(krb5_ret_stringz(sp, &sinst), out1);
187         snprintf (client_name, sizeof(client_name),
188                   "%s.%s@%s", name, inst, realm);
189         snprintf (server_name, sizeof(server_name),
190                   "%s.%s@%s", sname, sinst, config->v4_realm);
191         
192         kdc_log(context, config, 0, "AS-REQ (krb4) %s from %s for %s",
193                 client_name, from, server_name);
194
195         ret = _kdc_db_fetch4(context, config, name, inst, realm, 
196                              HDB_F_GET_CLIENT, &client);
197         if(ret) {
198             kdc_log(context, config, 0, "Client not found in database: %s: %s",
199                     client_name, krb5_get_err_text(context, ret));
200             make_err_reply(context, reply, KRB4ET_KDC_PR_UNKNOWN,
201                            "principal unknown");
202             goto out1;
203         }
204         ret = _kdc_db_fetch4(context, config, sname, sinst, config->v4_realm,
205                              HDB_F_GET_SERVER, &server);
206         if(ret){
207             kdc_log(context, config, 0, "Server not found in database: %s: %s",
208                     server_name, krb5_get_err_text(context, ret));
209             make_err_reply(context, reply, KRB4ET_KDC_PR_UNKNOWN,
210                            "principal unknown");
211             goto out1;
212         }
213
214         ret = _kdc_check_flags (context, config, 
215                                 client, client_name,
216                                 server, server_name,
217                                 TRUE);
218         if (ret) {
219             /* good error code? */
220             make_err_reply(context, reply, KRB4ET_KDC_NAME_EXP,
221                            "operation not allowed");
222             goto out1;
223         }
224
225         if (config->enable_v4_per_principal &&
226             client->entry.flags.allow_kerberos4 == 0)
227         {
228             kdc_log(context, config, 0,
229                     "Per principal Kerberos 4 flag not turned on for %s",
230                     client_name);
231             make_err_reply(context, reply, KRB4ET_KDC_NULL_KEY,
232                            "allow kerberos4 flag required");
233             goto out1;
234         }
235
236         /*
237          * There's no way to do pre-authentication in v4 and thus no
238          * good error code to return if preauthentication is required.
239          */
240
241         if (config->require_preauth
242             || client->entry.flags.require_preauth
243             || server->entry.flags.require_preauth) {
244             kdc_log(context, config, 0,
245                     "Pre-authentication required for v4-request: "
246                     "%s for %s",
247                     client_name, server_name);
248             make_err_reply(context, reply, KRB4ET_KDC_NULL_KEY,
249                            "preauth required");
250             goto out1;
251         }
252
253         ret = _kdc_get_des_key(context, client, FALSE, FALSE, &ckey);
254         if(ret){
255             kdc_log(context, config, 0, "no suitable DES key for client");
256             make_err_reply(context, reply, KRB4ET_KDC_NULL_KEY, 
257                            "no suitable DES key for client");
258             goto out1;
259         }
260
261 #if 0
262         /* this is not necessary with the new code in libkrb */
263         /* find a properly salted key */
264         while(ckey->salt == NULL || ckey->salt->salt.length != 0)
265             ret = hdb_next_keytype2key(context, &client->entry, KEYTYPE_DES, &ckey);
266         if(ret){
267             kdc_log(context, config, 0, "No version-4 salted key in database -- %s.%s@%s", 
268                     name, inst, realm);
269             make_err_reply(context, reply, KRB4ET_KDC_NULL_KEY, 
270                            "No version-4 salted key in database");
271             goto out1;
272         }
273 #endif
274         
275         ret = _kdc_get_des_key(context, server, TRUE, FALSE, &skey);
276         if(ret){
277             kdc_log(context, config, 0, "no suitable DES key for server");
278             make_err_reply(context, reply, KRB4ET_KDC_NULL_KEY, 
279                            "no suitable DES key for server");
280             goto out1;
281         }
282
283         max_life = _krb5_krb_life_to_time(0, life);
284         if(client->entry.max_life)
285             max_life = min(max_life, *client->entry.max_life);
286         if(server->entry.max_life)
287             max_life = min(max_life, *server->entry.max_life);
288
289         life = krb_time_to_life(kdc_time, kdc_time + max_life);
290     
291         ret = krb5_generate_random_keyblock(context,
292                                             ETYPE_DES_PCBC_NONE,
293                                             &session);
294         if (ret) {
295             make_err_reply(context, reply, KFAILURE,
296                            "Not enough random i KDC");
297             goto out1;
298         }
299         
300         ret = _krb5_krb_create_ticket(context,
301                                       0,
302                                       name,
303                                       inst,
304                                       config->v4_realm,
305                                       addr->sin_addr.s_addr,
306                                       &session,
307                                       life,
308                                       kdc_time,
309                                       sname,
310                                       sinst,
311                                       &skey->key,
312                                       &ticket);
313         if (ret) {
314             krb5_free_keyblock_contents(context, &session);
315             make_err_reply(context, reply, KFAILURE,
316                            "failed to create v4 ticket");
317             goto out1;
318         }
319
320         ret = _krb5_krb_create_ciph(context,
321                                     &session,
322                                     sname,
323                                     sinst,
324                                     config->v4_realm,
325                                     life,
326                                     server->entry.kvno % 255,
327                                     &ticket,
328                                     kdc_time,
329                                     &ckey->key,
330                                     &cipher);
331         krb5_free_keyblock_contents(context, &session);
332         krb5_data_free(&ticket);
333         if (ret) {
334             make_err_reply(context, reply, KFAILURE, 
335                            "Failed to create v4 cipher");
336             goto out1;
337         }
338         
339         ret = _krb5_krb_create_auth_reply(context,
340                                           name,
341                                           inst,
342                                           realm,
343                                           req_time,
344                                           0,
345                                           client->entry.pw_end ? *client->entry.pw_end : 0,
346                                           client->entry.kvno % 256,
347                                           &cipher,
348                                           reply);
349         krb5_data_free(&cipher);
350
351     out1:
352         break;
353     }
354     case AUTH_MSG_APPL_REQUEST: {
355         struct _krb5_krb_auth_data ad;
356         int8_t kvno;
357         int8_t ticket_len;
358         int8_t req_len;
359         krb5_data auth;
360         int32_t address;
361         size_t pos;
362         krb5_principal tgt_princ = NULL;
363         hdb_entry_ex *tgt = NULL;
364         Key *tkey;
365         time_t max_end, actual_end, issue_time;
366         
367         memset(&ad, 0, sizeof(ad));
368         krb5_data_zero(&auth);
369
370         RCHECK(krb5_ret_int8(sp, &kvno), out2);
371         RCHECK(krb5_ret_stringz(sp, &realm), out2);
372         
373         ret = krb5_425_conv_principal(context, "krbtgt", realm,
374                                       config->v4_realm,
375                                       &tgt_princ);
376         if(ret){
377             kdc_log(context, config, 0,
378                     "Converting krbtgt principal (krb4): %s", 
379                     krb5_get_err_text(context, ret));
380             make_err_reply(context, reply, KFAILURE, 
381                            "Failed to convert v4 principal (krbtgt)");
382             goto out2;
383         }
384
385         ret = _kdc_db_fetch(context, config, tgt_princ,
386                             HDB_F_GET_KRBTGT, NULL, &tgt);
387         if(ret){
388             char *s;
389             s = kdc_log_msg(context, config, 0, "Ticket-granting ticket not "
390                             "found in database (krb4): krbtgt.%s@%s: %s", 
391                             realm, config->v4_realm,
392                             krb5_get_err_text(context, ret));
393             make_err_reply(context, reply, KFAILURE, s);
394             free(s);
395             goto out2;
396         }
397         
398         if(tgt->entry.kvno % 256 != kvno){
399             kdc_log(context, config, 0,
400                     "tgs-req (krb4) with old kvno %d (current %d) for "
401                     "krbtgt.%s@%s", kvno, tgt->entry.kvno % 256, 
402                     realm, config->v4_realm);
403             make_err_reply(context, reply, KRB4ET_KDC_AUTH_EXP,
404                            "old krbtgt kvno used");
405             goto out2;
406         }
407
408         ret = _kdc_get_des_key(context, tgt, TRUE, FALSE, &tkey);
409         if(ret){
410             kdc_log(context, config, 0, 
411                     "no suitable DES key for krbtgt (krb4)");
412             make_err_reply(context, reply, KRB4ET_KDC_NULL_KEY, 
413                            "no suitable DES key for krbtgt");
414             goto out2;
415         }
416
417         RCHECK(krb5_ret_int8(sp, &ticket_len), out2);
418         RCHECK(krb5_ret_int8(sp, &req_len), out2);
419         
420         pos = krb5_storage_seek(sp, ticket_len + req_len, SEEK_CUR);
421         
422         auth.data = buf;
423         auth.length = pos;
424
425         if (config->check_ticket_addresses)
426             address = addr->sin_addr.s_addr;
427         else
428             address = 0;
429
430         ret = _krb5_krb_rd_req(context, &auth, "krbtgt", realm, 
431                                config->v4_realm,
432                                address, &tkey->key, &ad);
433         if(ret){
434             kdc_log(context, config, 0, "krb_rd_req: %d", ret);
435             make_err_reply(context, reply, ret, "failed to parse request");
436             goto out2;
437         }
438         
439         RCHECK(krb5_ret_int32(sp, &req_time), out2);
440         if(lsb)
441             req_time = swap32(req_time);
442         RCHECK(krb5_ret_uint8(sp, &life), out2);
443         RCHECK(krb5_ret_stringz(sp, &sname), out2);
444         RCHECK(krb5_ret_stringz(sp, &sinst), out2);
445         snprintf (server_name, sizeof(server_name),
446                   "%s.%s@%s",
447                   sname, sinst, config->v4_realm);
448         snprintf (client_name, sizeof(client_name),
449                   "%s.%s@%s",
450                   ad.pname, ad.pinst, ad.prealm);
451
452         kdc_log(context, config, 0, "TGS-REQ (krb4) %s from %s for %s",
453                 client_name, from, server_name);
454         
455         if(strcmp(ad.prealm, realm)){
456             kdc_log(context, config, 0, 
457                     "Can't hop realms (krb4) %s -> %s", realm, ad.prealm);
458             make_err_reply(context, reply, KRB4ET_KDC_PR_UNKNOWN, 
459                            "Can't hop realms");
460             goto out2;
461         }
462
463         if (!config->enable_v4_cross_realm && strcmp(realm, config->v4_realm) != 0) {
464             kdc_log(context, config, 0, 
465                     "krb4 Cross-realm %s -> %s disabled",
466                     realm, config->v4_realm);
467             make_err_reply(context, reply, KRB4ET_KDC_PR_UNKNOWN,
468                            "Can't hop realms");
469             goto out2;
470         }
471
472         if(strcmp(sname, "changepw") == 0){
473             kdc_log(context, config, 0, 
474                     "Bad request for changepw ticket (krb4)");
475             make_err_reply(context, reply, KRB4ET_KDC_PR_UNKNOWN, 
476                            "Can't authorize password change based on TGT");
477             goto out2;
478         }
479         
480         ret = _kdc_db_fetch4(context, config, ad.pname, ad.pinst, ad.prealm,
481                              HDB_F_GET_CLIENT, &client);
482         if(ret && ret != HDB_ERR_NOENTRY) {
483             char *s;
484             s = kdc_log_msg(context, config, 0,
485                             "Client not found in database: (krb4) %s: %s",
486                             client_name, krb5_get_err_text(context, ret));
487             make_err_reply(context, reply, KRB4ET_KDC_PR_UNKNOWN, s);
488             free(s);
489             goto out2;
490         }
491         if (client == NULL && strcmp(ad.prealm, config->v4_realm) == 0) {
492             char *s;
493             s = kdc_log_msg(context, config, 0,
494                             "Local client not found in database: (krb4) "
495                             "%s", client_name);
496             make_err_reply(context, reply, KRB4ET_KDC_PR_UNKNOWN, s);
497             free(s);
498             goto out2;
499         }
500
501         ret = _kdc_db_fetch4(context, config, sname, sinst, config->v4_realm,
502                              HDB_F_GET_SERVER, &server);
503         if(ret){
504             char *s;
505             s = kdc_log_msg(context, config, 0,
506                             "Server not found in database (krb4): %s: %s",
507                             server_name, krb5_get_err_text(context, ret));
508             make_err_reply(context, reply, KRB4ET_KDC_PR_UNKNOWN, s);
509             free(s);
510             goto out2;
511         }
512
513         ret = _kdc_check_flags (context, config, 
514                                 client, client_name,
515                                 server, server_name,
516                                 FALSE);
517         if (ret) {
518             make_err_reply(context, reply, KRB4ET_KDC_NAME_EXP,
519                            "operation not allowed");
520             goto out2;
521         }
522
523         ret = _kdc_get_des_key(context, server, TRUE, FALSE, &skey);
524         if(ret){
525             kdc_log(context, config, 0, 
526                     "no suitable DES key for server (krb4)");
527             make_err_reply(context, reply, KRB4ET_KDC_NULL_KEY, 
528                            "no suitable DES key for server");
529             goto out2;
530         }
531
532         max_end = _krb5_krb_life_to_time(ad.time_sec, ad.life);
533         max_end = min(max_end, _krb5_krb_life_to_time(kdc_time, life));
534         if(server->entry.max_life)
535             max_end = min(max_end, kdc_time + *server->entry.max_life);
536         if(client && client->entry.max_life)
537             max_end = min(max_end, kdc_time + *client->entry.max_life);
538         life = min(life, krb_time_to_life(kdc_time, max_end));
539         
540         issue_time = kdc_time;
541         actual_end = _krb5_krb_life_to_time(issue_time, life);
542         while (actual_end > max_end && life > 1) {
543             /* move them into the next earlier lifetime bracket */
544             life--;
545             actual_end = _krb5_krb_life_to_time(issue_time, life);
546         }
547         if (actual_end > max_end) {
548             /* if life <= 1 and it's still too long, backdate the ticket */
549             issue_time -= actual_end - max_end;
550         }
551
552         {
553             krb5_data ticket, cipher;
554             krb5_keyblock session;
555
556             krb5_data_zero(&ticket);
557             krb5_data_zero(&cipher);
558
559             ret = krb5_generate_random_keyblock(context,
560                                                 ETYPE_DES_PCBC_NONE,
561                                                 &session);
562             if (ret) {
563                 make_err_reply(context, reply, KFAILURE,
564                                "Not enough random i KDC");
565                 goto out2;
566             }
567         
568             ret = _krb5_krb_create_ticket(context,
569                                           0,
570                                           ad.pname,
571                                           ad.pinst,
572                                           ad.prealm,
573                                           addr->sin_addr.s_addr,
574                                           &session,
575                                           life,
576                                           issue_time,
577                                           sname,
578                                           sinst,
579                                           &skey->key,
580                                           &ticket);
581             if (ret) {
582                 krb5_free_keyblock_contents(context, &session);
583                 make_err_reply(context, reply, KFAILURE,
584                                "failed to create v4 ticket");
585                 goto out2;
586             }
587
588             ret = _krb5_krb_create_ciph(context,
589                                         &session,
590                                         sname,
591                                         sinst,
592                                         config->v4_realm,
593                                         life,
594                                         server->entry.kvno % 255,
595                                         &ticket,
596                                         issue_time,
597                                         &ad.session,
598                                         &cipher);
599             krb5_free_keyblock_contents(context, &session);
600             if (ret) {
601                 make_err_reply(context, reply, KFAILURE,
602                                "failed to create v4 cipher");
603                 goto out2;
604             }
605             
606             ret = _krb5_krb_create_auth_reply(context,
607                                               ad.pname,
608                                               ad.pinst,
609                                               ad.prealm,
610                                               req_time,
611                                               0,
612                                               0,
613                                               0,
614                                               &cipher,
615                                               reply);
616             krb5_data_free(&cipher);
617         }
618     out2:
619         _krb5_krb_free_auth_data(context, &ad);
620         if(tgt_princ)
621             krb5_free_principal(context, tgt_princ);
622         if(tgt)
623             _kdc_free_ent(context, tgt);
624         break;
625     }
626     case AUTH_MSG_ERR_REPLY:
627         break;
628     default:
629         kdc_log(context, config, 0, "Unknown message type (krb4): %d from %s", 
630                 msg_type, from);
631         
632         make_err_reply(context, reply, KFAILURE, "Unknown message type");
633     }
634  out:
635     if(name)
636         free(name);
637     if(inst)
638         free(inst);
639     if(realm)
640         free(realm);
641     if(sname)
642         free(sname);
643     if(sinst)
644         free(sinst);
645     if(client)
646         _kdc_free_ent(context, client);
647     if(server)
648         _kdc_free_ent(context, server);
649     krb5_storage_free(sp);
650     return 0;
651 }
652
653 krb5_error_code
654 _kdc_encode_v4_ticket(krb5_context context, 
655                       krb5_kdc_configuration *config,
656                       void *buf, size_t len, const EncTicketPart *et,
657                       const PrincipalName *service, size_t *size)
658 {
659     krb5_storage *sp;
660     krb5_error_code ret;
661     char name[40], inst[40], realm[40];
662     char sname[40], sinst[40];
663
664     {
665         krb5_principal princ;
666         _krb5_principalname2krb5_principal(context,
667                                            &princ,
668                                            *service,
669                                            et->crealm);
670         ret = krb5_524_conv_principal(context, 
671                                       princ,
672                                       sname,
673                                       sinst,
674                                       realm);
675         krb5_free_principal(context, princ);
676         if(ret)
677             return ret;
678
679         _krb5_principalname2krb5_principal(context,
680                                            &princ,
681                                            et->cname,
682                                            et->crealm);
683                                      
684         ret = krb5_524_conv_principal(context, 
685                                       princ,
686                                       name,
687                                       inst,
688                                       realm);
689         krb5_free_principal(context, princ);
690     }
691     if(ret)
692         return ret;
693
694     sp = krb5_storage_emem();
695     
696     krb5_store_int8(sp, 0); /* flags */
697     krb5_store_stringz(sp, name);
698     krb5_store_stringz(sp, inst);
699     krb5_store_stringz(sp, realm);
700     {
701         unsigned char tmp[4] = { 0, 0, 0, 0 };
702         int i;
703         if(et->caddr){
704             for(i = 0; i < et->caddr->len; i++)
705                 if(et->caddr->val[i].addr_type == AF_INET &&
706                    et->caddr->val[i].address.length == 4){
707                     memcpy(tmp, et->caddr->val[i].address.data, 4);
708                     break;
709                 }
710         }
711         krb5_storage_write(sp, tmp, sizeof(tmp));
712     }
713
714     if((et->key.keytype != ETYPE_DES_CBC_MD5 &&
715         et->key.keytype != ETYPE_DES_CBC_MD4 &&
716         et->key.keytype != ETYPE_DES_CBC_CRC) || 
717        et->key.keyvalue.length != 8)
718         return -1;
719     krb5_storage_write(sp, et->key.keyvalue.data, 8);
720     
721     {
722         time_t start = et->starttime ? *et->starttime : et->authtime;
723         krb5_store_int8(sp, krb_time_to_life(start, et->endtime));
724         krb5_store_int32(sp, start);
725     }
726
727     krb5_store_stringz(sp, sname);
728     krb5_store_stringz(sp, sinst);
729     
730     {
731         krb5_data data;
732         krb5_storage_to_data(sp, &data);
733         krb5_storage_free(sp);
734         *size = (data.length + 7) & ~7; /* pad to 8 bytes */
735         if(*size > len)
736             return -1;
737         memset((unsigned char*)buf - *size + 1, 0, *size);
738         memcpy((unsigned char*)buf - *size + 1, data.data, data.length);
739         krb5_data_free(&data);
740     }
741     return 0;
742 }
743
744 krb5_error_code
745 _kdc_get_des_key(krb5_context context, 
746                  hdb_entry_ex *principal, krb5_boolean is_server, 
747                  krb5_boolean prefer_afs_key, Key **ret_key)
748 {
749     Key *v5_key = NULL, *v4_key = NULL, *afs_key = NULL, *server_key = NULL;
750     int i;
751     krb5_enctype etypes[] = { ETYPE_DES_CBC_MD5, 
752                               ETYPE_DES_CBC_MD4, 
753                               ETYPE_DES_CBC_CRC };
754
755     for(i = 0;
756         i < sizeof(etypes)/sizeof(etypes[0])
757             && (v5_key == NULL || v4_key == NULL || 
758                 afs_key == NULL || server_key == NULL);
759         ++i) {
760         Key *key = NULL;
761         while(hdb_next_enctype2key(context, &principal->entry, etypes[i], &key) == 0) {
762             if(key->salt == NULL) {
763                 if(v5_key == NULL)
764                     v5_key = key;
765             } else if(key->salt->type == hdb_pw_salt && 
766                       key->salt->salt.length == 0) {
767                 if(v4_key == NULL)
768                     v4_key = key;
769             } else if(key->salt->type == hdb_afs3_salt) {
770                 if(afs_key == NULL)
771                     afs_key = key;
772             } else if(server_key == NULL)
773                 server_key = key;
774         }
775     }
776
777     if(prefer_afs_key) {
778         if(afs_key)
779             *ret_key = afs_key;
780         else if(v4_key)
781             *ret_key = v4_key;
782         else if(v5_key)
783             *ret_key = v5_key;
784         else if(is_server && server_key)
785             *ret_key = server_key;
786         else
787             return KRB4ET_KDC_NULL_KEY;
788     } else {
789         if(v4_key)
790             *ret_key = v4_key;
791         else if(afs_key)
792             *ret_key = afs_key;
793         else  if(v5_key)
794             *ret_key = v5_key;
795         else if(is_server && server_key)
796             *ret_key = server_key;
797         else
798             return KRB4ET_KDC_NULL_KEY;
799     }
800
801     if((*ret_key)->key.keyvalue.length == 0)
802         return KRB4ET_KDC_NULL_KEY;
803     return 0;
804 }
805