1 /*
2 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
3 * Use is subject to license terms.
4 */
5
6
7 /*
8 * kdc/do_tgs_req.c
9 *
10 * Copyright 1990,1991,2001 by the Massachusetts Institute of Technology.
11 * All Rights Reserved.
12 *
13 * Export of this software from the United States of America may
14 * require a specific license from the United States Government.
15 * It is the responsibility of any person or organization contemplating
16 * export to obtain such a license before exporting.
17 *
18 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
19 * distribute this software and its documentation for any purpose and
20 * without fee is hereby granted, provided that the above copyright
21 * notice appear in all copies and that both that copyright notice and
22 * this permission notice appear in supporting documentation, and that
23 * the name of M.I.T. not be used in advertising or publicity pertaining
24 * to distribution of the software without specific, written prior
25 * permission. Furthermore if you modify this software you must label
26 * your software as modified software and not distribute it in such a
27 * fashion that it might be confused with the original M.I.T. software.
28 * M.I.T. makes no representations about the suitability of
29 * this software for any purpose. It is provided "as is" without express
30 * or implied warranty.
31 *
32 *
33 * KDC Routines to deal with TGS_REQ's
34 */
35
36 #include "k5-int.h"
37 #include "com_err.h"
38
39 #include <syslog.h>
40 #ifdef HAVE_NETINET_IN_H
41 #include <sys/types.h>
42 #include <netinet/in.h>
43 #ifndef hpux
44 #include <arpa/inet.h>
45 #endif
46 #endif
47
48 #include "kdc_util.h"
49 #include "policy.h"
50 #include "extern.h"
51 #include "adm_proto.h"
52
53 extern krb5_error_code setup_server_realm(krb5_principal);
54
55 static void find_alternate_tgs (krb5_kdc_req *, krb5_db_entry *,
56 krb5_boolean *, int *,
57 const krb5_fulladdr *from, char *cname);
58
59 static krb5_error_code prepare_error_tgs (krb5_kdc_req *, krb5_ticket *,
60 int, const char *, krb5_data **,
61 const char *);
62
63 /*ARGSUSED*/
64 krb5_error_code
process_tgs_req(krb5_data * pkt,const krb5_fulladdr * from,krb5_data ** response)65 process_tgs_req(krb5_data *pkt, const krb5_fulladdr *from,
66 krb5_data **response)
67 {
68 krb5_keyblock * subkey;
69 krb5_kdc_req *request = 0;
70 krb5_db_entry server;
71 krb5_kdc_rep reply;
72 krb5_enc_kdc_rep_part reply_encpart;
73 krb5_ticket ticket_reply, *header_ticket = 0;
74 int st_idx = 0;
75 krb5_enc_tkt_part enc_tkt_reply;
76 krb5_transited enc_tkt_transited;
77 int newtransited = 0;
78 krb5_error_code retval = 0;
79 int nprincs = 0;
80 krb5_boolean more;
81 krb5_timestamp kdc_time, authtime=0;
82 krb5_keyblock session_key;
83 krb5_timestamp until, rtime;
84 krb5_keyblock encrypting_key;
85 krb5_key_data *server_key;
86 char *cname = 0, *sname = 0, *tmp = 0;
87 const char *fromstring = 0;
88 krb5_last_req_entry *nolrarray[2], nolrentry;
89 /* krb5_address *noaddrarray[1]; */
90 krb5_enctype useenctype;
91 int errcode, errcode2;
92 register int i;
93 int firstpass = 1;
94 const char *status = 0;
95 char ktypestr[128];
96 char rep_etypestr[128];
97 char fromstringbuf[70];
98 long long tmp_server_times, tmp_realm_times;
99
100 (void) memset(&encrypting_key, 0, sizeof(krb5_keyblock));
101 (void) memset(&session_key, 0, sizeof(krb5_keyblock));
102
103 retval = decode_krb5_tgs_req(pkt, &request);
104 if (retval)
105 return retval;
106
107 ktypes2str(ktypestr, sizeof(ktypestr),
108 request->nktypes, request->ktype);
109 /*
110 * setup_server_realm() sets up the global realm-specific data pointer.
111 */
112 if ((retval = setup_server_realm(request->server)))
113 return retval;
114
115 fromstring = inet_ntop(ADDRTYPE2FAMILY(from->address->addrtype),
116 from->address->contents,
117 fromstringbuf, sizeof(fromstringbuf));
118 if (!fromstring)
119 fromstring = "<unknown>";
120
121 if ((errcode = krb5_unparse_name(kdc_context, request->server, &sname))) {
122 status = "UNPARSING SERVER";
123 goto cleanup;
124 }
125 limit_string(sname);
126
127 /* errcode = kdc_process_tgs_req(request, from, pkt, &req_authdat); */
128 errcode = kdc_process_tgs_req(request, from, pkt, &header_ticket, &subkey);
129
130 if (header_ticket && header_ticket->enc_part2 &&
131 (errcode2 = krb5_unparse_name(kdc_context,
132 header_ticket->enc_part2->client,
133 &cname))) {
134 status = "UNPARSING CLIENT";
135 errcode = errcode2;
136 goto cleanup;
137 }
138 limit_string(cname);
139
140 if (errcode) {
141 status = "PROCESS_TGS";
142 goto cleanup;
143 }
144
145 if (!header_ticket) {
146 errcode = KRB5_NO_TKT_SUPPLIED; /* XXX? */
147 status="UNEXPECTED NULL in header_ticket";
148 goto cleanup;
149 }
150
151 /*
152 * We've already dealt with the AP_REQ authentication, so we can
153 * use header_ticket freely. The encrypted part (if any) has been
154 * decrypted with the session key.
155 */
156
157 authtime = header_ticket->enc_part2->times.authtime;
158
159 /* XXX make sure server here has the proper realm...taken from AP_REQ
160 header? */
161
162 nprincs = 1;
163 if ((errcode = krb5_db_get_principal(kdc_context, request->server, &server,
164 &nprincs, &more))) {
165 status = "LOOKING_UP_SERVER";
166 nprincs = 0;
167 goto cleanup;
168 }
169 tgt_again:
170 if (more) {
171 status = "NON_UNIQUE_PRINCIPAL";
172 errcode = KRB5KDC_ERR_PRINCIPAL_NOT_UNIQUE;
173 goto cleanup;
174 } else if (nprincs != 1) {
175 /*
176 * might be a request for a TGT for some other realm; we
177 * should do our best to find such a TGS in this db
178 */
179 if (firstpass && krb5_is_tgs_principal(request->server) == TRUE) {
180 if (krb5_princ_size(kdc_context, request->server) == 2) {
181 krb5_data *server_1 =
182 krb5_princ_component(kdc_context, request->server, 1);
183 krb5_data *tgs_1 =
184 krb5_princ_component(kdc_context, tgs_server, 1);
185
186 if (!tgs_1 || server_1->length != tgs_1->length ||
187 memcmp(server_1->data, tgs_1->data, tgs_1->length)) {
188 krb5_db_free_principal(kdc_context, &server, nprincs);
189 find_alternate_tgs(request, &server, &more, &nprincs,
190 from, cname);
191 firstpass = 0;
192 goto tgt_again;
193 }
194 }
195 }
196 krb5_db_free_principal(kdc_context, &server, nprincs);
197 status = "UNKNOWN_SERVER";
198 errcode = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
199 goto cleanup;
200 }
201
202 if ((errcode = krb5_timeofday(kdc_context, &kdc_time))) {
203 status = "TIME_OF_DAY";
204 goto cleanup;
205 }
206
207 if ((retval = validate_tgs_request(request, server, header_ticket,
208 kdc_time, &status))) {
209 if (!status)
210 status = "UNKNOWN_REASON";
211 errcode = retval + ERROR_TABLE_BASE_krb5;
212 goto cleanup;
213 }
214
215 /*
216 * We pick the session keytype here....
217 *
218 * Some special care needs to be taken in the user-to-user
219 * case, since we don't know what keytypes the application server
220 * which is doing user-to-user authentication can support. We
221 * know that it at least must be able to support the encryption
222 * type of the session key in the TGT, since otherwise it won't be
223 * able to decrypt the U2U ticket! So we use that in preference
224 * to anything else.
225 */
226 useenctype = 0;
227 if (isflagset(request->kdc_options, KDC_OPT_ENC_TKT_IN_SKEY)) {
228 krb5_keyblock * st_sealing_key;
229 krb5_kvno st_srv_kvno;
230 krb5_enctype etype;
231
232 /*
233 * Get the key for the second ticket, and decrypt it.
234 */
235 if ((errcode = kdc_get_server_key(request->second_ticket[st_idx],
236 &st_sealing_key,
237 &st_srv_kvno))) {
238 status = "2ND_TKT_SERVER";
239 goto cleanup;
240 }
241 errcode = krb5_decrypt_tkt_part(kdc_context, st_sealing_key,
242 request->second_ticket[st_idx]);
243 krb5_free_keyblock(kdc_context, st_sealing_key);
244 if (errcode) {
245 status = "2ND_TKT_DECRYPT";
246 goto cleanup;
247 }
248
249 etype = request->second_ticket[st_idx]->enc_part2->session->enctype;
250 if (!krb5_c_valid_enctype(etype)) {
251 status = "BAD_ETYPE_IN_2ND_TKT";
252 errcode = KRB5KDC_ERR_ETYPE_NOSUPP;
253 goto cleanup;
254 }
255
256 for (i = 0; i < request->nktypes; i++) {
257 if (request->ktype[i] == etype) {
258 useenctype = etype;
259 break;
260 }
261 }
262 }
263
264 /*
265 * Select the keytype for the ticket session key.
266 */
267 if ((useenctype == 0) &&
268 (useenctype = select_session_keytype(kdc_context, &server,
269 request->nktypes,
270 request->ktype)) == 0) {
271 /* unsupported ktype */
272 status = "BAD_ENCRYPTION_TYPE";
273 errcode = KRB5KDC_ERR_ETYPE_NOSUPP;
274 goto cleanup;
275 }
276
277 errcode = krb5_c_make_random_key(kdc_context, useenctype, &session_key);
278
279 if (errcode) {
280 /* random key failed */
281 status = "RANDOM_KEY_FAILED";
282 goto cleanup;
283 }
284
285 ticket_reply.server = request->server; /* XXX careful for realm... */
286
287 enc_tkt_reply.flags = 0;
288 enc_tkt_reply.times.starttime = 0;
289
290 /*
291 * Fix header_ticket's starttime; if it's zero, fill in the
292 * authtime's value.
293 */
294 if (!(header_ticket->enc_part2->times.starttime))
295 header_ticket->enc_part2->times.starttime =
296 header_ticket->enc_part2->times.authtime;
297
298 /* don't use new addresses unless forwarded, see below */
299
300 enc_tkt_reply.caddrs = header_ticket->enc_part2->caddrs;
301 /* noaddrarray[0] = 0; */
302 reply_encpart.caddrs = 0; /* optional...don't put it in */
303
304 /* It should be noted that local policy may affect the */
305 /* processing of any of these flags. For example, some */
306 /* realms may refuse to issue renewable tickets */
307
308 if (isflagset(request->kdc_options, KDC_OPT_FORWARDABLE))
309 setflag(enc_tkt_reply.flags, TKT_FLG_FORWARDABLE);
310
311 if (isflagset(request->kdc_options, KDC_OPT_FORWARDED)) {
312 setflag(enc_tkt_reply.flags, TKT_FLG_FORWARDED);
313
314 /* include new addresses in ticket & reply */
315
316 enc_tkt_reply.caddrs = request->addresses;
317 reply_encpart.caddrs = request->addresses;
318 }
319 if (isflagset(header_ticket->enc_part2->flags, TKT_FLG_FORWARDED))
320 setflag(enc_tkt_reply.flags, TKT_FLG_FORWARDED);
321
322 if (isflagset(request->kdc_options, KDC_OPT_PROXIABLE))
323 setflag(enc_tkt_reply.flags, TKT_FLG_PROXIABLE);
324
325 if (isflagset(request->kdc_options, KDC_OPT_PROXY)) {
326 setflag(enc_tkt_reply.flags, TKT_FLG_PROXY);
327
328 /* include new addresses in ticket & reply */
329
330 enc_tkt_reply.caddrs = request->addresses;
331 reply_encpart.caddrs = request->addresses;
332 }
333
334 if (isflagset(request->kdc_options, KDC_OPT_ALLOW_POSTDATE))
335 setflag(enc_tkt_reply.flags, TKT_FLG_MAY_POSTDATE);
336
337 if (isflagset(request->kdc_options, KDC_OPT_POSTDATED)) {
338 setflag(enc_tkt_reply.flags, TKT_FLG_POSTDATED);
339 setflag(enc_tkt_reply.flags, TKT_FLG_INVALID);
340 enc_tkt_reply.times.starttime = request->from;
341 } else
342 enc_tkt_reply.times.starttime = kdc_time;
343
344 if (isflagset(request->kdc_options, KDC_OPT_VALIDATE)) {
345 /* BEWARE of allocation hanging off of ticket & enc_part2, it belongs
346 to the caller */
347 ticket_reply = *(header_ticket);
348 enc_tkt_reply = *(header_ticket->enc_part2);
349 clear(enc_tkt_reply.flags, TKT_FLG_INVALID);
350 }
351
352 if (isflagset(request->kdc_options, KDC_OPT_RENEW)) {
353 krb5_deltat old_life;
354
355 /* BEWARE of allocation hanging off of ticket & enc_part2, it belongs
356 to the caller */
357 ticket_reply = *(header_ticket);
358 enc_tkt_reply = *(header_ticket->enc_part2);
359
360 old_life = enc_tkt_reply.times.endtime - enc_tkt_reply.times.starttime;
361
362 enc_tkt_reply.times.starttime = kdc_time;
363 enc_tkt_reply.times.endtime =
364 min(header_ticket->enc_part2->times.renew_till,
365 kdc_time + old_life);
366 } else {
367 /* not a renew request */
368 enc_tkt_reply.times.starttime = kdc_time;
369 until = (request->till == 0) ? kdc_infinity : request->till;
370
371 /* SUNW */
372 tmp_server_times = (long long) enc_tkt_reply.times.starttime
373 + server.max_life;
374
375 tmp_realm_times = (long long) enc_tkt_reply.times.starttime
376 + max_life_for_realm;
377
378 enc_tkt_reply.times.endtime =
379 min(until,
380 min(tmp_server_times,
381 min(tmp_realm_times,
382 min(header_ticket->enc_part2->times.endtime,
383 KRB5_KDB_EXPIRATION)))); /* SUNW */
384 /*
385 enc_tkt_reply.times.endtime =
386 min(until, min(enc_tkt_reply.times.starttime + server.max_life,
387 min(enc_tkt_reply.times.starttime + max_life_for_realm,
388 min(header_ticket->enc_part2->times.endtime)));
389 */
390 if (isflagset(request->kdc_options, KDC_OPT_RENEWABLE_OK) &&
391 (enc_tkt_reply.times.endtime < request->till) &&
392 isflagset(header_ticket->enc_part2->flags,
393 TKT_FLG_RENEWABLE)) {
394 setflag(request->kdc_options, KDC_OPT_RENEWABLE);
395 request->rtime =
396 min(request->till,
397 min(KRB5_KDB_EXPIRATION,
398 header_ticket->enc_part2->times.renew_till));
399 }
400 }
401 rtime = (request->rtime == 0) ? kdc_infinity : request->rtime;
402
403 if (isflagset(request->kdc_options, KDC_OPT_RENEWABLE)) {
404 /* already checked above in policy check to reject request for a
405 renewable ticket using a non-renewable ticket */
406 setflag(enc_tkt_reply.flags, TKT_FLG_RENEWABLE);
407 tmp_realm_times = (long long) enc_tkt_reply.times.starttime +
408 min(server.max_renewable_life,max_renewable_life_for_realm);
409 enc_tkt_reply.times.renew_till =
410 min(rtime,
411 min(header_ticket->enc_part2->times.renew_till,
412 min (tmp_realm_times, KRB5_KDB_EXPIRATION)));
413 } else {
414 enc_tkt_reply.times.renew_till = 0;
415 }
416
417 /*
418 * Set authtime to be the same as header_ticket's
419 */
420 enc_tkt_reply.times.authtime = header_ticket->enc_part2->times.authtime;
421
422 /*
423 * Propagate the preauthentication flags through to the returned ticket.
424 */
425 if (isflagset(header_ticket->enc_part2->flags, TKT_FLG_PRE_AUTH))
426 setflag(enc_tkt_reply.flags, TKT_FLG_PRE_AUTH);
427
428 if (isflagset(header_ticket->enc_part2->flags, TKT_FLG_HW_AUTH))
429 setflag(enc_tkt_reply.flags, TKT_FLG_HW_AUTH);
430
431 /* starttime is optional, and treated as authtime if not present.
432 so we can nuke it if it matches */
433 if (enc_tkt_reply.times.starttime == enc_tkt_reply.times.authtime)
434 enc_tkt_reply.times.starttime = 0;
435
436 /* assemble any authorization data */
437 if (request->authorization_data.ciphertext.data) {
438 krb5_data scratch;
439
440 scratch.length = request->authorization_data.ciphertext.length;
441 if (!(scratch.data =
442 malloc(request->authorization_data.ciphertext.length))) {
443 status = "AUTH_NOMEM";
444 errcode = ENOMEM;
445 goto cleanup;
446 }
447
448 if ((errcode = krb5_c_decrypt(kdc_context,
449 header_ticket->enc_part2->session,
450 KRB5_KEYUSAGE_TGS_REQ_AD_SESSKEY,
451 0, &request->authorization_data,
452 &scratch))) {
453 status = "AUTH_ENCRYPT_FAIL";
454 free(scratch.data);
455 goto cleanup;
456 }
457
458 /* scratch now has the authorization data, so we decode it */
459 errcode = decode_krb5_authdata(&scratch, &(request->unenc_authdata));
460 free(scratch.data);
461 if (errcode) {
462 status = "AUTH_DECODE";
463 goto cleanup;
464 }
465
466 if ((errcode =
467 concat_authorization_data(request->unenc_authdata,
468 header_ticket->enc_part2->authorization_data,
469 &enc_tkt_reply.authorization_data))) {
470 status = "CONCAT_AUTH";
471 goto cleanup;
472 }
473 } else
474 enc_tkt_reply.authorization_data =
475 header_ticket->enc_part2->authorization_data;
476
477 enc_tkt_reply.session = &session_key;
478 enc_tkt_reply.client = header_ticket->enc_part2->client;
479 enc_tkt_reply.transited.tr_type = KRB5_DOMAIN_X500_COMPRESS;
480 enc_tkt_reply.transited.tr_contents = empty_string; /* equivalent of "" */
481
482 /*
483 * Only add the realm of the presented tgt to the transited list if
484 * it is different than the local realm (cross-realm) and it is different
485 * than the realm of the client (since the realm of the client is already
486 * implicitly part of the transited list and should not be explicitly
487 * listed).
488 */
489
490 /* realm compare is like strcmp, but knows how to deal with these args */
491 if (realm_compare(header_ticket->server, tgs_server) ||
492 realm_compare(header_ticket->server, enc_tkt_reply.client)) {
493 /* tgt issued by local realm or issued by realm of client */
494 enc_tkt_reply.transited = header_ticket->enc_part2->transited;
495 } else {
496 /* tgt issued by some other realm and not the realm of the client */
497 /* assemble new transited field into allocated storage */
498 if (header_ticket->enc_part2->transited.tr_type !=
499 KRB5_DOMAIN_X500_COMPRESS) {
500 status = "BAD_TRTYPE";
501 errcode = KRB5KDC_ERR_TRTYPE_NOSUPP;
502 goto cleanup;
503 }
504 enc_tkt_transited.tr_type = KRB5_DOMAIN_X500_COMPRESS;
505 enc_tkt_transited.magic = 0;
506 enc_tkt_transited.tr_contents.magic = 0;
507 enc_tkt_transited.tr_contents.data = 0;
508 enc_tkt_transited.tr_contents.length = 0;
509 enc_tkt_reply.transited = enc_tkt_transited;
510 if ((errcode =
511 add_to_transited(&header_ticket->enc_part2->transited.tr_contents,
512 &enc_tkt_reply.transited.tr_contents,
513 header_ticket->server,
514 enc_tkt_reply.client,
515 request->server))) {
516 status = "ADD_TR_FAIL";
517 goto cleanup;
518 }
519 newtransited = 1;
520 }
521 if (!isflagset (request->kdc_options, KDC_OPT_DISABLE_TRANSITED_CHECK)) {
522 unsigned int tlen;
523 char *tdots;
524
525 errcode = krb5_check_transited_list (kdc_context,
526 &enc_tkt_reply.transited.tr_contents,
527 krb5_princ_realm (kdc_context, header_ticket->enc_part2->client),
528 krb5_princ_realm (kdc_context, request->server));
529 tlen = enc_tkt_reply.transited.tr_contents.length;
530 tdots = tlen > 125 ? "..." : "";
531 tlen = tlen > 125 ? 125 : tlen;
532
533 if (errcode == 0) {
534 setflag (enc_tkt_reply.flags, TKT_FLG_TRANSIT_POLICY_CHECKED);
535 } else if (errcode == KRB5KRB_AP_ERR_ILL_CR_TKT)
536 krb5_klog_syslog (LOG_INFO,
537 "bad realm transit path from '%s' to '%s' "
538 "via '%.*s%s'",
539 cname ? cname : "<unknown client>",
540 sname ? sname : "<unknown server>",
541 tlen,
542 enc_tkt_reply.transited.tr_contents.data,
543 tdots);
544 else {
545 const char *emsg = krb5_get_error_message(kdc_context, errcode);
546 krb5_klog_syslog (LOG_ERR,
547 "unexpected error checking transit from "
548 "'%s' to '%s' via '%.*s%s': %s",
549 cname ? cname : "<unknown client>",
550 sname ? sname : "<unknown server>",
551 tlen,
552 enc_tkt_reply.transited.tr_contents.data,
553 tdots, emsg);
554 krb5_free_error_message(kdc_context, emsg);
555 }
556 } else
557 krb5_klog_syslog (LOG_INFO, "not checking transit path");
558 if (reject_bad_transit
559 && !isflagset (enc_tkt_reply.flags, TKT_FLG_TRANSIT_POLICY_CHECKED)) {
560 errcode = KRB5KDC_ERR_POLICY;
561 status = "BAD_TRANSIT";
562 goto cleanup;
563 }
564
565 ticket_reply.enc_part2 = &enc_tkt_reply;
566
567 /*
568 * If we are doing user-to-user authentication, then make sure
569 * that the client for the second ticket matches the request
570 * server, and then encrypt the ticket using the session key of
571 * the second ticket.
572 */
573 if (isflagset(request->kdc_options, KDC_OPT_ENC_TKT_IN_SKEY)) {
574 /*
575 * Make sure the client for the second ticket matches
576 * requested server.
577 */
578 krb5_enc_tkt_part *t2enc = request->second_ticket[st_idx]->enc_part2;
579 krb5_principal client2 = t2enc->client;
580 if (!krb5_principal_compare(kdc_context, request->server, client2)) {
581 if ((errcode = krb5_unparse_name(kdc_context, client2, &tmp)))
582 tmp = 0;
583 if (tmp != NULL)
584 limit_string(tmp);
585 audit_krb5kdc_tgs_req_2ndtktmm(
586 (struct in_addr *)from->address->contents,
587 (in_port_t)from->port,
588 0, cname, sname);
589 krb5_klog_syslog(LOG_INFO,
590 "TGS_REQ %s: 2ND_TKT_MISMATCH: "
591 "authtime %d, %s for %s, 2nd tkt client %s",
592 fromstring, authtime,
593 cname ? cname : "<unknown client>",
594 sname ? sname : "<unknown server>",
595 tmp ? tmp : "<unknown>");
596 errcode = KRB5KDC_ERR_SERVER_NOMATCH;
597 goto cleanup;
598 }
599
600 ticket_reply.enc_part.kvno = 0;
601 ticket_reply.enc_part.enctype = t2enc->session->enctype;
602 if ((errcode = krb5_encrypt_tkt_part(kdc_context, t2enc->session,
603 &ticket_reply))) {
604 status = "2ND_TKT_ENCRYPT";
605 goto cleanup;
606 }
607 st_idx++;
608 } else {
609 /*
610 * Find the server key
611 */
612 if ((errcode = krb5_dbe_find_enctype(kdc_context, &server,
613 -1, /* ignore keytype */
614 -1, /* Ignore salttype */
615 0, /* Get highest kvno */
616 &server_key))) {
617 status = "FINDING_SERVER_KEY";
618 goto cleanup;
619 }
620 /* convert server.key into a real key (it may be encrypted
621 * in the database) */
622 if ((errcode = krb5_dbekd_decrypt_key_data(kdc_context,
623 &master_keyblock,
624 server_key, &encrypting_key,
625 NULL))) {
626 status = "DECRYPT_SERVER_KEY";
627 goto cleanup;
628 }
629 errcode = krb5_encrypt_tkt_part(kdc_context, &encrypting_key,
630 &ticket_reply);
631 krb5_free_keyblock_contents(kdc_context, &encrypting_key);
632 if (errcode) {
633 status = "TKT_ENCRYPT";
634 goto cleanup;
635 }
636 ticket_reply.enc_part.kvno = server_key->key_data_kvno;
637 }
638
639 /* Start assembling the response */
640 reply.msg_type = KRB5_TGS_REP;
641 reply.padata = 0; /* always */
642 reply.client = header_ticket->enc_part2->client;
643 reply.enc_part.kvno = 0; /* We are using the session key */
644 reply.ticket = &ticket_reply;
645
646 reply_encpart.session = &session_key;
647 reply_encpart.nonce = request->nonce;
648
649 /* copy the time fields EXCEPT for authtime; its location
650 is used for ktime */
651 reply_encpart.times = enc_tkt_reply.times;
652 reply_encpart.times.authtime = header_ticket->enc_part2->times.authtime;
653
654 /* starttime is optional, and treated as authtime if not present.
655 so we can nuke it if it matches */
656 if (enc_tkt_reply.times.starttime == enc_tkt_reply.times.authtime)
657 enc_tkt_reply.times.starttime = 0;
658
659 nolrentry.lr_type = KRB5_LRQ_NONE;
660 nolrentry.value = 0;
661 nolrarray[0] = &nolrentry;
662 nolrarray[1] = 0;
663 reply_encpart.last_req = nolrarray; /* not available for TGS reqs */
664 reply_encpart.key_exp = 0; /* ditto */
665 reply_encpart.flags = enc_tkt_reply.flags;
666 reply_encpart.server = ticket_reply.server;
667
668 /* use the session key in the ticket, unless there's a subsession key
669 in the AP_REQ */
670
671 reply.enc_part.enctype = subkey ? subkey->enctype :
672 header_ticket->enc_part2->session->enctype;
673 errcode = krb5_encode_kdc_rep(kdc_context, KRB5_TGS_REP, &reply_encpart,
674 subkey ? 1 : 0,
675 subkey ? subkey :
676 header_ticket->enc_part2->session,
677 &reply, response);
678 if (errcode) {
679 status = "ENCODE_KDC_REP";
680 } else {
681 status = "ISSUE";
682 }
683
684 if (ticket_reply.enc_part.ciphertext.data) {
685 memset(ticket_reply.enc_part.ciphertext.data, 0,
686 ticket_reply.enc_part.ciphertext.length);
687 free(ticket_reply.enc_part.ciphertext.data);
688 ticket_reply.enc_part.ciphertext.data = NULL;
689 }
690 /* these parts are left on as a courtesy from krb5_encode_kdc_rep so we
691 can use them in raw form if needed. But, we don't... */
692 if (reply.enc_part.ciphertext.data) {
693 memset(reply.enc_part.ciphertext.data, 0,
694 reply.enc_part.ciphertext.length);
695 free(reply.enc_part.ciphertext.data);
696 reply.enc_part.ciphertext.data = NULL;
697 }
698
699 cleanup:
700 if (status) {
701 const char * emsg = NULL;
702 audit_krb5kdc_tgs_req((struct in_addr *)from->address->contents,
703 (in_port_t)from->port, 0,
704 cname ? cname : "<unknown client>",
705 sname ? sname : "<unknown client>",
706 errcode);
707 if (!errcode)
708 rep_etypes2str(rep_etypestr, sizeof(rep_etypestr), &reply);
709 if (errcode)
710 emsg = krb5_get_error_message (kdc_context, errcode);
711 krb5_klog_syslog(LOG_INFO,
712 "TGS_REQ (%s) %s: %s: authtime %d, "
713 "%s%s %s for %s%s%s",
714 ktypestr,
715 fromstring, status, authtime,
716 !errcode ? rep_etypestr : "",
717 !errcode ? "," : "",
718 cname ? cname : "<unknown client>",
719 sname ? sname : "<unknown server>",
720 errcode ? ", " : "",
721 errcode ? emsg : "");
722 if (errcode)
723 krb5_free_error_message (kdc_context, emsg);
724 }
725
726 if (errcode) {
727 int got_err = 0;
728 if (status == 0) {
729 status = krb5_get_error_message (kdc_context, errcode);
730 got_err = 1;
731 }
732 errcode -= ERROR_TABLE_BASE_krb5;
733 if (errcode < 0 || errcode > 128)
734 errcode = KRB_ERR_GENERIC;
735
736 retval = prepare_error_tgs(request, header_ticket, errcode,
737 fromstring, response, status);
738 if (got_err) {
739 krb5_free_error_message (kdc_context, status);
740 status = 0;
741 }
742 }
743
744 if (header_ticket)
745 krb5_free_ticket(kdc_context, header_ticket);
746 if (request)
747 krb5_free_kdc_req(kdc_context, request);
748 if (cname)
749 free(cname);
750 if (sname)
751 free(sname);
752 if (nprincs)
753 krb5_db_free_principal(kdc_context, &server, 1);
754 if (session_key.contents)
755 krb5_free_keyblock_contents(kdc_context, &session_key);
756 if (newtransited)
757 free(enc_tkt_reply.transited.tr_contents.data);
758
759 return retval;
760 }
761
762 static krb5_error_code
prepare_error_tgs(krb5_kdc_req * request,krb5_ticket * ticket,int error,const char * ident,krb5_data ** response,const char * status)763 prepare_error_tgs (krb5_kdc_req *request, krb5_ticket *ticket, int error,
764 const char *ident, krb5_data **response, const char *status)
765 {
766 krb5_error errpkt;
767 krb5_error_code retval;
768 krb5_data *scratch;
769
770 errpkt.ctime = request->nonce;
771 errpkt.cusec = 0;
772
773 if ((retval = krb5_us_timeofday(kdc_context, &errpkt.stime,
774 &errpkt.susec)))
775 return(retval);
776 errpkt.error = error;
777 errpkt.server = request->server;
778 if (ticket && ticket->enc_part2)
779 errpkt.client = ticket->enc_part2->client;
780 else
781 errpkt.client = 0;
782 errpkt.text.length = strlen(status) + 1;
783 if (!(errpkt.text.data = malloc(errpkt.text.length)))
784 return ENOMEM;
785 (void) strcpy(errpkt.text.data, status);
786
787 if (!(scratch = (krb5_data *)malloc(sizeof(*scratch)))) {
788 free(errpkt.text.data);
789 return ENOMEM;
790 }
791 errpkt.e_data.length = 0;
792 errpkt.e_data.data = 0;
793
794 retval = krb5_mk_error(kdc_context, &errpkt, scratch);
795 free(errpkt.text.data);
796 if (retval)
797 free(scratch);
798 else
799 *response = scratch;
800
801 return retval;
802 }
803
804 /*
805 * The request seems to be for a ticket-granting service somewhere else,
806 * but we don't have a ticket for the final TGS. Try to give the requestor
807 * some intermediate realm.
808 */
809 static void
find_alternate_tgs(krb5_kdc_req * request,krb5_db_entry * server,krb5_boolean * more,int * nprincs,const krb5_fulladdr * from,char * cname)810 find_alternate_tgs(krb5_kdc_req *request, krb5_db_entry *server,
811 krb5_boolean *more, int *nprincs,
812 const krb5_fulladdr *from, char *cname)
813 {
814 krb5_error_code retval;
815 krb5_principal *plist, *pl2;
816 krb5_data tmp;
817
818 *nprincs = 0;
819 *more = FALSE;
820
821 /*
822 * Call to krb5_princ_component is normally not safe but is so
823 * here only because find_alternate_tgs() is only called from
824 * somewhere that has already checked the number of components in
825 * the principal.
826 */
827 if ((retval = krb5_walk_realm_tree(kdc_context,
828 krb5_princ_realm(kdc_context, request->server),
829 krb5_princ_component(kdc_context, request->server, 1),
830 &plist, KRB5_REALM_BRANCH_CHAR)))
831 return;
832
833 /* move to the end */
834 for (pl2 = plist; *pl2; pl2++);
835
836 /* the first entry in this array is for krbtgt/local@local, so we
837 ignore it */
838 while (--pl2 > plist) {
839 *nprincs = 1;
840 tmp = *krb5_princ_realm(kdc_context, *pl2);
841 krb5_princ_set_realm(kdc_context, *pl2,
842 krb5_princ_realm(kdc_context, tgs_server));
843 retval = krb5_db_get_principal(kdc_context, *pl2, server, nprincs, more);
844 krb5_princ_set_realm(kdc_context, *pl2, &tmp);
845 if (retval) {
846 *nprincs = 0;
847 *more = FALSE;
848 krb5_free_realm_tree(kdc_context, plist);
849 return;
850 }
851 if (*more) {
852 krb5_db_free_principal(kdc_context, server, *nprincs);
853 continue;
854 } else if (*nprincs == 1) {
855 /* Found it! */
856 krb5_principal tmpprinc;
857 char *sname;
858
859 tmp = *krb5_princ_realm(kdc_context, *pl2);
860 krb5_princ_set_realm(kdc_context, *pl2,
861 krb5_princ_realm(kdc_context, tgs_server));
862 if ((retval = krb5_copy_principal(kdc_context, *pl2, &tmpprinc))) {
863 krb5_db_free_principal(kdc_context, server, *nprincs);
864 krb5_princ_set_realm(kdc_context, *pl2, &tmp);
865 continue;
866 }
867 krb5_princ_set_realm(kdc_context, *pl2, &tmp);
868
869 krb5_free_principal(kdc_context, request->server);
870 request->server = tmpprinc;
871 if (krb5_unparse_name(kdc_context, request->server, &sname)) {
872
873 audit_krb5kdc_tgs_req_alt_tgt(
874 (struct in_addr *)from->address->contents,
875 (in_port_t)from->port,
876 0, cname, "<unparseable>", 0);
877 krb5_klog_syslog(LOG_INFO,
878 "TGS_REQ: issuing alternate <un-unparseable> TGT");
879 } else {
880 limit_string(sname);
881 audit_krb5kdc_tgs_req_alt_tgt(
882 (struct in_addr *)from->address->contents,
883 (in_port_t)from->port,
884 0, cname, sname, 0);
885 krb5_klog_syslog(LOG_INFO,
886 "TGS_REQ: issuing TGT %s", sname);
887 free(sname);
888 }
889 return;
890 }
891 krb5_db_free_principal(kdc_context, server, *nprincs);
892 continue;
893 }
894
895 *nprincs = 0;
896 *more = FALSE;
897 krb5_free_realm_tree(kdc_context, plist);
898 return;
899 }
900