source: trunk/server/source3/libads/authdata.c@ 434

Last change on this file since 434 was 414, checked in by Herwig Bauernfeind, 16 years ago

Samba 3.5.0: Initial import
File size: 15.7 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3 kerberos authorization data (PAC) utility library
4 Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2003
5 Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
6 Copyright (C) Andrew Tridgell 2001
7 Copyright (C) Luke Howard 2002-2003
8 Copyright (C) Stefan Metzmacher 2004-2005
9 Copyright (C) Guenther Deschner 2005,2007,2008
10
11 This program is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 3 of the License, or
14 (at your option) any later version.
15
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
20
21 You should have received a copy of the GNU General Public License
22 along with this program. If not, see <http://www.gnu.org/licenses/>.
23*/
24
25#include "includes.h"
26#include "librpc/gen_ndr/ndr_krb5pac.h"
27#include "smb_krb5.h"
28#include "authdata.h"
29
30#ifdef HAVE_KRB5
31
32/****************************************************************
33****************************************************************/
34
35static krb5_error_code check_pac_checksum(TALLOC_CTX *mem_ctx,
36 DATA_BLOB pac_data,
37 struct PAC_SIGNATURE_DATA *sig,
38 krb5_context context,
39 krb5_keyblock *keyblock)
40{
41 krb5_error_code ret;
42 krb5_checksum cksum;
43 krb5_keyusage usage = 0;
44
45 smb_krb5_checksum_from_pac_sig(&cksum, sig);
46
47#ifdef HAVE_KRB5_KU_OTHER_CKSUM /* Heimdal */
48 usage = KRB5_KU_OTHER_CKSUM;
49#elif defined(HAVE_KRB5_KEYUSAGE_APP_DATA_CKSUM) /* MIT */
50 usage = KRB5_KEYUSAGE_APP_DATA_CKSUM;
51#else
52#error UNKNOWN_KRB5_KEYUSAGE
53#endif
54
55 ret = smb_krb5_verify_checksum(context,
56 keyblock,
57 usage,
58 &cksum,
59 pac_data.data,
60 pac_data.length);
61
62 if (ret) {
63 DEBUG(2,("check_pac_checksum: PAC Verification failed: %s (%d)\n",
64 error_message(ret), ret));
65 return ret;
66 }
67
68 return ret;
69}
70
71/****************************************************************
72****************************************************************/
73
74 NTSTATUS decode_pac_data(TALLOC_CTX *mem_ctx,
75 DATA_BLOB *pac_data_blob,
76 krb5_context context,
77 krb5_keyblock *service_keyblock,
78 krb5_const_principal client_principal,
79 time_t tgs_authtime,
80 struct PAC_DATA **pac_data_out)
81{
82 NTSTATUS status;
83 enum ndr_err_code ndr_err;
84 krb5_error_code ret;
85 DATA_BLOB modified_pac_blob;
86
87 NTTIME tgs_authtime_nttime;
88 krb5_principal client_principal_pac = NULL;
89 int i;
90
91 struct PAC_SIGNATURE_DATA *srv_sig_ptr = NULL;
92 struct PAC_SIGNATURE_DATA *kdc_sig_ptr = NULL;
93 struct PAC_SIGNATURE_DATA *srv_sig_wipe = NULL;
94 struct PAC_SIGNATURE_DATA *kdc_sig_wipe = NULL;
95 struct PAC_LOGON_NAME *logon_name = NULL;
96 struct PAC_LOGON_INFO *logon_info = NULL;
97 struct PAC_DATA *pac_data = NULL;
98 struct PAC_DATA_RAW *pac_data_raw = NULL;
99
100 DATA_BLOB *srv_sig_blob = NULL;
101 DATA_BLOB *kdc_sig_blob = NULL;
102
103 *pac_data_out = NULL;
104
105 pac_data = TALLOC_ZERO_P(mem_ctx, struct PAC_DATA);
106 pac_data_raw = TALLOC_ZERO_P(mem_ctx, struct PAC_DATA_RAW);
107 kdc_sig_wipe = TALLOC_ZERO_P(mem_ctx, struct PAC_SIGNATURE_DATA);
108 srv_sig_wipe = TALLOC_ZERO_P(mem_ctx, struct PAC_SIGNATURE_DATA);
109 if (!pac_data_raw || !pac_data || !kdc_sig_wipe || !srv_sig_wipe) {
110 return NT_STATUS_NO_MEMORY;
111 }
112
113 ndr_err = ndr_pull_struct_blob(pac_data_blob, pac_data,
114 NULL, pac_data,
115 (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
116 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
117 status = ndr_map_error2ntstatus(ndr_err);
118 DEBUG(0,("can't parse the PAC: %s\n",
119 nt_errstr(status)));
120 return status;
121 }
122
123 if (pac_data->num_buffers < 4) {
124 /* we need logon_ingo, service_key and kdc_key */
125 DEBUG(0,("less than 4 PAC buffers\n"));
126 return NT_STATUS_INVALID_PARAMETER;
127 }
128
129 ndr_err = ndr_pull_struct_blob(pac_data_blob, pac_data_raw,
130 NULL, pac_data_raw,
131 (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA_RAW);
132 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
133 status = ndr_map_error2ntstatus(ndr_err);
134 DEBUG(0,("can't parse the PAC: %s\n",
135 nt_errstr(status)));
136 return status;
137 }
138
139 if (pac_data_raw->num_buffers < 4) {
140 /* we need logon_ingo, service_key and kdc_key */
141 DEBUG(0,("less than 4 PAC buffers\n"));
142 return NT_STATUS_INVALID_PARAMETER;
143 }
144
145 if (pac_data->num_buffers != pac_data_raw->num_buffers) {
146 /* we need logon_ingo, service_key and kdc_key */
147 DEBUG(0,("misparse! PAC_DATA has %d buffers while PAC_DATA_RAW has %d\n",
148 pac_data->num_buffers, pac_data_raw->num_buffers));
149 return NT_STATUS_INVALID_PARAMETER;
150 }
151
152 for (i=0; i < pac_data->num_buffers; i++) {
153 if (pac_data->buffers[i].type != pac_data_raw->buffers[i].type) {
154 DEBUG(0,("misparse! PAC_DATA buffer %d has type %d while PAC_DATA_RAW has %d\n",
155 i, pac_data->buffers[i].type, pac_data->buffers[i].type));
156 return NT_STATUS_INVALID_PARAMETER;
157 }
158 switch (pac_data->buffers[i].type) {
159 case PAC_TYPE_LOGON_INFO:
160 if (!pac_data->buffers[i].info) {
161 break;
162 }
163 logon_info = pac_data->buffers[i].info->logon_info.info;
164 break;
165 case PAC_TYPE_SRV_CHECKSUM:
166 if (!pac_data->buffers[i].info) {
167 break;
168 }
169 srv_sig_ptr = &pac_data->buffers[i].info->srv_cksum;
170 srv_sig_blob = &pac_data_raw->buffers[i].info->remaining;
171 break;
172 case PAC_TYPE_KDC_CHECKSUM:
173 if (!pac_data->buffers[i].info) {
174 break;
175 }
176 kdc_sig_ptr = &pac_data->buffers[i].info->kdc_cksum;
177 kdc_sig_blob = &pac_data_raw->buffers[i].info->remaining;
178 break;
179 case PAC_TYPE_LOGON_NAME:
180 logon_name = &pac_data->buffers[i].info->logon_name;
181 break;
182 default:
183 break;
184 }
185 }
186
187 if (!logon_info) {
188 DEBUG(0,("PAC no logon_info\n"));
189 return NT_STATUS_INVALID_PARAMETER;
190 }
191
192 if (!logon_name) {
193 DEBUG(0,("PAC no logon_name\n"));
194 return NT_STATUS_INVALID_PARAMETER;
195 }
196
197 if (!srv_sig_ptr || !srv_sig_blob) {
198 DEBUG(0,("PAC no srv_key\n"));
199 return NT_STATUS_INVALID_PARAMETER;
200 }
201
202 if (!kdc_sig_ptr || !kdc_sig_blob) {
203 DEBUG(0,("PAC no kdc_key\n"));
204 return NT_STATUS_INVALID_PARAMETER;
205 }
206
207 /* Find and zero out the signatures, as required by the signing algorithm */
208
209 /* We find the data blobs above, now we parse them to get at the exact portion we should zero */
210 ndr_err = ndr_pull_struct_blob(kdc_sig_blob, kdc_sig_wipe,
211 NULL, kdc_sig_wipe,
212 (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
213 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
214 status = ndr_map_error2ntstatus(ndr_err);
215 DEBUG(0,("can't parse the KDC signature: %s\n",
216 nt_errstr(status)));
217 return status;
218 }
219
220 ndr_err = ndr_pull_struct_blob(srv_sig_blob, srv_sig_wipe,
221 NULL, srv_sig_wipe,
222 (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
223 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
224 status = ndr_map_error2ntstatus(ndr_err);
225 DEBUG(0,("can't parse the SRV signature: %s\n",
226 nt_errstr(status)));
227 return status;
228 }
229
230 /* Now zero the decoded structure */
231 memset(kdc_sig_wipe->signature.data, '\0', kdc_sig_wipe->signature.length);
232 memset(srv_sig_wipe->signature.data, '\0', srv_sig_wipe->signature.length);
233
234 /* and reencode, back into the same place it came from */
235 ndr_err = ndr_push_struct_blob(kdc_sig_blob, pac_data_raw,
236 NULL, kdc_sig_wipe,
237 (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
238 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
239 status = ndr_map_error2ntstatus(ndr_err);
240 DEBUG(0,("can't repack the KDC signature: %s\n",
241 nt_errstr(status)));
242 return status;
243 }
244 ndr_err = ndr_push_struct_blob(srv_sig_blob, pac_data_raw,
245 NULL, srv_sig_wipe,
246 (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
247 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
248 status = ndr_map_error2ntstatus(ndr_err);
249 DEBUG(0,("can't repack the SRV signature: %s\n",
250 nt_errstr(status)));
251 return status;
252 }
253
254 /* push out the whole structure, but now with zero'ed signatures */
255 ndr_err = ndr_push_struct_blob(&modified_pac_blob, pac_data_raw,
256 NULL, pac_data_raw,
257 (ndr_push_flags_fn_t)ndr_push_PAC_DATA_RAW);
258 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
259 status = ndr_map_error2ntstatus(ndr_err);
260 DEBUG(0,("can't repack the RAW PAC: %s\n",
261 nt_errstr(status)));
262 return status;
263 }
264
265 /* verify by service_key */
266 ret = check_pac_checksum(mem_ctx,
267 modified_pac_blob, srv_sig_ptr,
268 context,
269 service_keyblock);
270 if (ret) {
271 DEBUG(1, ("PAC Decode: Failed to verify the service signature: %s\n",
272 error_message(ret)));
273 return NT_STATUS_ACCESS_DENIED;
274 }
275
276 /* Convert to NT time, so as not to loose accuracy in comparison */
277 unix_to_nt_time(&tgs_authtime_nttime, tgs_authtime);
278
279 if (tgs_authtime_nttime != logon_name->logon_time) {
280 DEBUG(2, ("PAC Decode: Logon time mismatch between ticket and PAC!\n"));
281 DEBUG(2, ("PAC Decode: PAC: %s\n", nt_time_string(mem_ctx, logon_name->logon_time)));
282 DEBUG(2, ("PAC Decode: Ticket: %s\n", nt_time_string(mem_ctx, tgs_authtime_nttime)));
283 return NT_STATUS_ACCESS_DENIED;
284 }
285
286 ret = smb_krb5_parse_name_norealm(context, logon_name->account_name,
287 &client_principal_pac);
288 if (ret) {
289 DEBUG(2, ("Could not parse name from incoming PAC: [%s]: %s\n",
290 logon_name->account_name,
291 error_message(ret)));
292 return NT_STATUS_INVALID_PARAMETER;
293 }
294
295 if (!smb_krb5_principal_compare_any_realm(context, client_principal, client_principal_pac)) {
296 DEBUG(2, ("Name in PAC [%s] does not match principal name in ticket\n",
297 logon_name->account_name));
298 krb5_free_principal(context, client_principal_pac);
299 return NT_STATUS_ACCESS_DENIED;
300 }
301
302 DEBUG(3,("Found account name from PAC: %s [%s]\n",
303 logon_info->info3.base.account_name.string,
304 logon_info->info3.base.full_name.string));
305
306 DEBUG(10,("Successfully validated Kerberos PAC\n"));
307
308 if (DEBUGLEVEL >= 10) {
309 const char *s;
310 s = NDR_PRINT_STRUCT_STRING(mem_ctx, PAC_DATA, pac_data);
311 if (s) {
312 DEBUGADD(10,("%s\n", s));
313 }
314 }
315
316 *pac_data_out = pac_data;
317
318 return NT_STATUS_OK;
319}
320
321/****************************************************************
322****************************************************************/
323
324struct PAC_LOGON_INFO *get_logon_info_from_pac(struct PAC_DATA *pac_data)
325{
326 int i;
327
328 for (i=0; i < pac_data->num_buffers; i++) {
329
330 if (pac_data->buffers[i].type != PAC_TYPE_LOGON_INFO) {
331 continue;
332 }
333
334 return pac_data->buffers[i].info->logon_info.info;
335 }
336
337 return NULL;
338}
339
340/****************************************************************
341****************************************************************/
342
343NTSTATUS kerberos_return_pac(TALLOC_CTX *mem_ctx,
344 const char *name,
345 const char *pass,
346 time_t time_offset,
347 time_t *expire_time,
348 time_t *renew_till_time,
349 const char *cache_name,
350 bool request_pac,
351 bool add_netbios_addr,
352 time_t renewable_time,
353 const char *impersonate_princ_s,
354 struct PAC_DATA **pac_ret)
355{
356 krb5_error_code ret;
357 NTSTATUS status = NT_STATUS_INVALID_PARAMETER;
358 DATA_BLOB tkt, ap_rep, sesskey1, sesskey2;
359 struct PAC_DATA *pac_data = NULL;
360 char *client_princ_out = NULL;
361 const char *auth_princ = NULL;
362 const char *local_service = NULL;
363 const char *cc = "MEMORY:kerberos_return_pac";
364
365 ZERO_STRUCT(tkt);
366 ZERO_STRUCT(ap_rep);
367 ZERO_STRUCT(sesskey1);
368 ZERO_STRUCT(sesskey2);
369
370 if (!name || !pass) {
371 return NT_STATUS_INVALID_PARAMETER;
372 }
373
374 if (cache_name) {
375 cc = cache_name;
376 }
377
378 if (!strchr_m(name, '@')) {
379 auth_princ = talloc_asprintf(mem_ctx, "%s@%s", name,
380 lp_realm());
381 } else {
382 auth_princ = name;
383 }
384 NT_STATUS_HAVE_NO_MEMORY(auth_princ);
385
386 local_service = talloc_asprintf(mem_ctx, "%s$@%s",
387 global_myname(), lp_realm());
388 NT_STATUS_HAVE_NO_MEMORY(local_service);
389
390 ret = kerberos_kinit_password_ext(auth_princ,
391 pass,
392 time_offset,
393 expire_time,
394 renew_till_time,
395 cc,
396 request_pac,
397 add_netbios_addr,
398 renewable_time,
399 &status);
400 if (ret) {
401 DEBUG(1,("kinit failed for '%s' with: %s (%d)\n",
402 auth_princ, error_message(ret), ret));
403 /* status already set */
404 goto out;
405 }
406
407 DEBUG(10,("got TGT for %s in %s\n", auth_princ, cc));
408 if (expire_time) {
409 DEBUGADD(10,("\tvalid until: %s (%d)\n",
410 http_timestring(talloc_tos(), *expire_time),
411 (int)*expire_time));
412 }
413 if (renew_till_time) {
414 DEBUGADD(10,("\trenewable till: %s (%d)\n",
415 http_timestring(talloc_tos(), *renew_till_time),
416 (int)*renew_till_time));
417 }
418
419 /* we cannot continue with krb5 when UF_DONT_REQUIRE_PREAUTH is set,
420 * in that case fallback to NTLM - gd */
421
422 if (expire_time && renew_till_time &&
423 (*expire_time == 0) && (*renew_till_time == 0)) {
424 return NT_STATUS_INVALID_LOGON_TYPE;
425 }
426
427 ret = cli_krb5_get_ticket(local_service,
428 time_offset,
429 &tkt,
430 &sesskey1,
431 0,
432 cc,
433 NULL,
434 impersonate_princ_s);
435 if (ret) {
436 DEBUG(1,("failed to get ticket for %s: %s\n",
437 local_service, error_message(ret)));
438 if (impersonate_princ_s) {
439 DEBUGADD(1,("tried S4U2SELF impersonation as: %s\n",
440 impersonate_princ_s));
441 }
442 status = krb5_to_nt_status(ret);
443 goto out;
444 }
445 status = ads_verify_ticket(mem_ctx,
446 lp_realm(),
447 time_offset,
448 &tkt,
449 &client_princ_out,
450 &pac_data,
451 &ap_rep,
452 &sesskey2,
453 False);
454 if (!NT_STATUS_IS_OK(status)) {
455 DEBUG(1,("ads_verify_ticket failed: %s\n",
456 nt_errstr(status)));
457 goto out;
458 }
459
460 if (!pac_data) {
461 DEBUG(1,("no PAC\n"));
462 status = NT_STATUS_INVALID_PARAMETER;
463 goto out;
464 }
465
466 *pac_ret = pac_data;
467
468out:
469 if (cc != cache_name) {
470 ads_kdestroy(cc);
471 }
472
473 data_blob_free(&tkt);
474 data_blob_free(&ap_rep);
475 data_blob_free(&sesskey1);
476 data_blob_free(&sesskey2);
477
478 TALLOC_FREE(client_princ_out);
479
480 return status;
481}
482
483/****************************************************************
484****************************************************************/
485
486static NTSTATUS kerberos_return_pac_logon_info(TALLOC_CTX *mem_ctx,
487 const char *name,
488 const char *pass,
489 time_t time_offset,
490 time_t *expire_time,
491 time_t *renew_till_time,
492 const char *cache_name,
493 bool request_pac,
494 bool add_netbios_addr,
495 time_t renewable_time,
496 const char *impersonate_princ_s,
497 struct PAC_LOGON_INFO **logon_info)
498{
499 NTSTATUS status;
500 struct PAC_DATA *pac_data = NULL;
501 struct PAC_LOGON_INFO *info = NULL;
502
503 status = kerberos_return_pac(mem_ctx,
504 name,
505 pass,
506 time_offset,
507 expire_time,
508 renew_till_time,
509 cache_name,
510 request_pac,
511 add_netbios_addr,
512 renewable_time,
513 impersonate_princ_s,
514 &pac_data);
515 if (!NT_STATUS_IS_OK(status)) {
516 return status;
517 }
518
519 if (!pac_data) {
520 DEBUG(3,("no pac\n"));
521 return NT_STATUS_INVALID_USER_BUFFER;
522 }
523
524 info = get_logon_info_from_pac(pac_data);
525 if (!info) {
526 DEBUG(1,("no logon_info\n"));
527 return NT_STATUS_INVALID_USER_BUFFER;
528 }
529
530 *logon_info = info;
531
532 return NT_STATUS_OK;
533}
534
535/****************************************************************
536****************************************************************/
537
538NTSTATUS kerberos_return_info3_from_pac(TALLOC_CTX *mem_ctx,
539 const char *name,
540 const char *pass,
541 time_t time_offset,
542 time_t *expire_time,
543 time_t *renew_till_time,
544 const char *cache_name,
545 bool request_pac,
546 bool add_netbios_addr,
547 time_t renewable_time,
548 const char *impersonate_princ_s,
549 struct netr_SamInfo3 **info3)
550{
551 NTSTATUS status;
552 struct PAC_LOGON_INFO *logon_info = NULL;
553
554 status = kerberos_return_pac_logon_info(mem_ctx,
555 name,
556 pass,
557 time_offset,
558 expire_time,
559 renew_till_time,
560 cache_name,
561 request_pac,
562 add_netbios_addr,
563 renewable_time,
564 impersonate_princ_s,
565 &logon_info);
566 if (!NT_STATUS_IS_OK(status)) {
567 return status;
568 }
569
570 *info3 = &logon_info->info3;
571
572 return NT_STATUS_OK;
573}
574#endif
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