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s3: Fix a memleak in check_pac_checksum
[Samba/ekacnet.git] / source3 / libads / authdata.c
blobee2dbde02c9e24782dc9865add0e31181fa2d4ae
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
35 static 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 bool bool_ret;
104
105 *pac_data_out = NULL;
106
107 pac_data = TALLOC_ZERO_P(mem_ctx, struct PAC_DATA);
108 pac_data_raw = TALLOC_ZERO_P(mem_ctx, struct PAC_DATA_RAW);
109 kdc_sig_wipe = TALLOC_ZERO_P(mem_ctx, struct PAC_SIGNATURE_DATA);
110 srv_sig_wipe = TALLOC_ZERO_P(mem_ctx, struct PAC_SIGNATURE_DATA);
111 if (!pac_data_raw || !pac_data || !kdc_sig_wipe || !srv_sig_wipe) {
112 return NT_STATUS_NO_MEMORY;
113 }
114
115 ndr_err = ndr_pull_struct_blob(pac_data_blob, pac_data,
116 NULL, pac_data,
117 (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
118 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
119 status = ndr_map_error2ntstatus(ndr_err);
120 DEBUG(0,("can't parse the PAC: %s\n",
121 nt_errstr(status)));
122 return status;
123 }
124
125 if (pac_data->num_buffers < 4) {
126 /* we need logon_ingo, service_key and kdc_key */
127 DEBUG(0,("less than 4 PAC buffers\n"));
128 return NT_STATUS_INVALID_PARAMETER;
129 }
130
131 ndr_err = ndr_pull_struct_blob(pac_data_blob, pac_data_raw,
132 NULL, pac_data_raw,
133 (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA_RAW);
134 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
135 status = ndr_map_error2ntstatus(ndr_err);
136 DEBUG(0,("can't parse the PAC: %s\n",
137 nt_errstr(status)));
138 return status;
139 }
140
141 if (pac_data_raw->num_buffers < 4) {
142 /* we need logon_ingo, service_key and kdc_key */
143 DEBUG(0,("less than 4 PAC buffers\n"));
144 return NT_STATUS_INVALID_PARAMETER;
145 }
146
147 if (pac_data->num_buffers != pac_data_raw->num_buffers) {
148 /* we need logon_ingo, service_key and kdc_key */
149 DEBUG(0,("misparse! PAC_DATA has %d buffers while PAC_DATA_RAW has %d\n",
150 pac_data->num_buffers, pac_data_raw->num_buffers));
151 return NT_STATUS_INVALID_PARAMETER;
152 }
153
154 for (i=0; i < pac_data->num_buffers; i++) {
155 if (pac_data->buffers[i].type != pac_data_raw->buffers[i].type) {
156 DEBUG(0,("misparse! PAC_DATA buffer %d has type %d while PAC_DATA_RAW has %d\n",
157 i, pac_data->buffers[i].type, pac_data->buffers[i].type));
158 return NT_STATUS_INVALID_PARAMETER;
159 }
160 switch (pac_data->buffers[i].type) {
161 case PAC_TYPE_LOGON_INFO:
162 if (!pac_data->buffers[i].info) {
163 break;
164 }
165 logon_info = pac_data->buffers[i].info->logon_info.info;
166 break;
167 case PAC_TYPE_SRV_CHECKSUM:
168 if (!pac_data->buffers[i].info) {
169 break;
170 }
171 srv_sig_ptr = &pac_data->buffers[i].info->srv_cksum;
172 srv_sig_blob = &pac_data_raw->buffers[i].info->remaining;
173 break;
174 case PAC_TYPE_KDC_CHECKSUM:
175 if (!pac_data->buffers[i].info) {
176 break;
177 }
178 kdc_sig_ptr = &pac_data->buffers[i].info->kdc_cksum;
179 kdc_sig_blob = &pac_data_raw->buffers[i].info->remaining;
180 break;
181 case PAC_TYPE_LOGON_NAME:
182 logon_name = &pac_data->buffers[i].info->logon_name;
183 break;
184 default:
185 break;
186 }
187 }
188
189 if (!logon_info) {
190 DEBUG(0,("PAC no logon_info\n"));
191 return NT_STATUS_INVALID_PARAMETER;
192 }
193
194 if (!logon_name) {
195 DEBUG(0,("PAC no logon_name\n"));
196 return NT_STATUS_INVALID_PARAMETER;
197 }
198
199 if (!srv_sig_ptr || !srv_sig_blob) {
200 DEBUG(0,("PAC no srv_key\n"));
201 return NT_STATUS_INVALID_PARAMETER;
202 }
203
204 if (!kdc_sig_ptr || !kdc_sig_blob) {
205 DEBUG(0,("PAC no kdc_key\n"));
206 return NT_STATUS_INVALID_PARAMETER;
207 }
208
209 /* Find and zero out the signatures, as required by the signing algorithm */
210
211 /* We find the data blobs above, now we parse them to get at the exact portion we should zero */
212 ndr_err = ndr_pull_struct_blob(kdc_sig_blob, kdc_sig_wipe,
213 NULL, kdc_sig_wipe,
214 (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
215 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
216 status = ndr_map_error2ntstatus(ndr_err);
217 DEBUG(0,("can't parse the KDC signature: %s\n",
218 nt_errstr(status)));
219 return status;
220 }
221
222 ndr_err = ndr_pull_struct_blob(srv_sig_blob, srv_sig_wipe,
223 NULL, srv_sig_wipe,
224 (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
225 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
226 status = ndr_map_error2ntstatus(ndr_err);
227 DEBUG(0,("can't parse the SRV signature: %s\n",
228 nt_errstr(status)));
229 return status;
230 }
231
232 /* Now zero the decoded structure */
233 memset(kdc_sig_wipe->signature.data, '\0', kdc_sig_wipe->signature.length);
234 memset(srv_sig_wipe->signature.data, '\0', srv_sig_wipe->signature.length);
235
236 /* and reencode, back into the same place it came from */
237 ndr_err = ndr_push_struct_blob(kdc_sig_blob, pac_data_raw,
238 NULL, kdc_sig_wipe,
239 (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
240 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
241 status = ndr_map_error2ntstatus(ndr_err);
242 DEBUG(0,("can't repack the KDC signature: %s\n",
243 nt_errstr(status)));
244 return status;
245 }
246 ndr_err = ndr_push_struct_blob(srv_sig_blob, pac_data_raw,
247 NULL, srv_sig_wipe,
248 (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
249 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
250 status = ndr_map_error2ntstatus(ndr_err);
251 DEBUG(0,("can't repack the SRV signature: %s\n",
252 nt_errstr(status)));
253 return status;
254 }
255
256 /* push out the whole structure, but now with zero'ed signatures */
257 ndr_err = ndr_push_struct_blob(&modified_pac_blob, pac_data_raw,
258 NULL, pac_data_raw,
259 (ndr_push_flags_fn_t)ndr_push_PAC_DATA_RAW);
260 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
261 status = ndr_map_error2ntstatus(ndr_err);
262 DEBUG(0,("can't repack the RAW PAC: %s\n",
263 nt_errstr(status)));
264 return status;
265 }
266
267 /* verify by service_key */
268 ret = check_pac_checksum(mem_ctx,
269 modified_pac_blob, srv_sig_ptr,
270 context,
271 service_keyblock);
272 if (ret) {
273 DEBUG(1, ("PAC Decode: Failed to verify the service signature: %s\n",
274 error_message(ret)));
275 return NT_STATUS_ACCESS_DENIED;
276 }
277
278 /* Convert to NT time, so as not to loose accuracy in comparison */
279 unix_to_nt_time(&tgs_authtime_nttime, tgs_authtime);
280
281 if (tgs_authtime_nttime != logon_name->logon_time) {
282 DEBUG(2, ("PAC Decode: Logon time mismatch between ticket and PAC!\n"));
283 DEBUG(2, ("PAC Decode: PAC: %s\n", nt_time_string(mem_ctx, logon_name->logon_time)));
284 DEBUG(2, ("PAC Decode: Ticket: %s\n", nt_time_string(mem_ctx, tgs_authtime_nttime)));
285 return NT_STATUS_ACCESS_DENIED;
286 }
287
288 ret = smb_krb5_parse_name_norealm(context, logon_name->account_name,
289 &client_principal_pac);
290 if (ret) {
291 DEBUG(2, ("Could not parse name from incoming PAC: [%s]: %s\n",
292 logon_name->account_name,
293 error_message(ret)));
294 return NT_STATUS_INVALID_PARAMETER;
295 }
296
297 bool_ret = smb_krb5_principal_compare_any_realm(
298 context, client_principal, client_principal_pac);
299
300 krb5_free_principal(context, client_principal_pac);
301
302 if (!bool_ret) {
303 DEBUG(2, ("Name in PAC [%s] does not match principal name in ticket\n",
304 logon_name->account_name));
305 return NT_STATUS_ACCESS_DENIED;
306 }
307
308 DEBUG(3,("Found account name from PAC: %s [%s]\n",
309 logon_info->info3.base.account_name.string,
310 logon_info->info3.base.full_name.string));
311
312 DEBUG(10,("Successfully validated Kerberos PAC\n"));
313
314 if (DEBUGLEVEL >= 10) {
315 const char *s;
316 s = NDR_PRINT_STRUCT_STRING(mem_ctx, PAC_DATA, pac_data);
317 if (s) {
318 DEBUGADD(10,("%s\n", s));
319 }
320 }
321
322 *pac_data_out = pac_data;
323
324 return NT_STATUS_OK;
325 }
326
327 /****************************************************************
328 ****************************************************************/
329
330 struct PAC_LOGON_INFO *get_logon_info_from_pac(struct PAC_DATA *pac_data)
331 {
332 int i;
333
334 for (i=0; i < pac_data->num_buffers; i++) {
335
336 if (pac_data->buffers[i].type != PAC_TYPE_LOGON_INFO) {
337 continue;
338 }
339
340 return pac_data->buffers[i].info->logon_info.info;
341 }
342
343 return NULL;
344 }
345
346 /****************************************************************
347 ****************************************************************/
348
349 NTSTATUS kerberos_return_pac(TALLOC_CTX *mem_ctx,
350 const char *name,
351 const char *pass,
352 time_t time_offset,
353 time_t *expire_time,
354 time_t *renew_till_time,
355 const char *cache_name,
356 bool request_pac,
357 bool add_netbios_addr,
358 time_t renewable_time,
359 const char *impersonate_princ_s,
360 struct PAC_DATA **pac_ret)
361 {
362 krb5_error_code ret;
363 NTSTATUS status = NT_STATUS_INVALID_PARAMETER;
364 DATA_BLOB tkt, ap_rep, sesskey1, sesskey2;
365 struct PAC_DATA *pac_data = NULL;
366 char *client_princ_out = NULL;
367 const char *auth_princ = NULL;
368 const char *local_service = NULL;
369 const char *cc = "MEMORY:kerberos_return_pac";
370
371 ZERO_STRUCT(tkt);
372 ZERO_STRUCT(ap_rep);
373 ZERO_STRUCT(sesskey1);
374 ZERO_STRUCT(sesskey2);
375
376 if (!name || !pass) {
377 return NT_STATUS_INVALID_PARAMETER;
378 }
379
380 if (cache_name) {
381 cc = cache_name;
382 }
383
384 if (!strchr_m(name, '@')) {
385 auth_princ = talloc_asprintf(mem_ctx, "%s@%s", name,
386 lp_realm());
387 } else {
388 auth_princ = name;
389 }
390 NT_STATUS_HAVE_NO_MEMORY(auth_princ);
391
392 local_service = talloc_asprintf(mem_ctx, "%s$@%s",
393 global_myname(), lp_realm());
394 NT_STATUS_HAVE_NO_MEMORY(local_service);
395
396 ret = kerberos_kinit_password_ext(auth_princ,
397 pass,
398 time_offset,
399 expire_time,
400 renew_till_time,
401 cc,
402 request_pac,
403 add_netbios_addr,
404 renewable_time,
405 &status);
406 if (ret) {
407 DEBUG(1,("kinit failed for '%s' with: %s (%d)\n",
408 auth_princ, error_message(ret), ret));
409 /* status already set */
410 goto out;
411 }
412
413 DEBUG(10,("got TGT for %s in %s\n", auth_princ, cc));
414 if (expire_time) {
415 DEBUGADD(10,("\tvalid until: %s (%d)\n",
416 http_timestring(talloc_tos(), *expire_time),
417 (int)*expire_time));
418 }
419 if (renew_till_time) {
420 DEBUGADD(10,("\trenewable till: %s (%d)\n",
421 http_timestring(talloc_tos(), *renew_till_time),
422 (int)*renew_till_time));
423 }
424
425 /* we cannot continue with krb5 when UF_DONT_REQUIRE_PREAUTH is set,
426 * in that case fallback to NTLM - gd */
427
428 if (expire_time && renew_till_time &&
429 (*expire_time == 0) && (*renew_till_time == 0)) {
430 return NT_STATUS_INVALID_LOGON_TYPE;
431 }
432
433 ret = cli_krb5_get_ticket(local_service,
434 time_offset,
435 &tkt,
436 &sesskey1,
437 0,
438 cc,
439 NULL,
440 impersonate_princ_s);
441 if (ret) {
442 DEBUG(1,("failed to get ticket for %s: %s\n",
443 local_service, error_message(ret)));
444 if (impersonate_princ_s) {
445 DEBUGADD(1,("tried S4U2SELF impersonation as: %s\n",
446 impersonate_princ_s));
447 }
448 status = krb5_to_nt_status(ret);
449 goto out;
450 }
451 status = ads_verify_ticket(mem_ctx,
452 lp_realm(),
453 time_offset,
454 &tkt,
455 &client_princ_out,
456 &pac_data,
457 &ap_rep,
458 &sesskey2,
459 False);
460 if (!NT_STATUS_IS_OK(status)) {
461 DEBUG(1,("ads_verify_ticket failed: %s\n",
462 nt_errstr(status)));
463 goto out;
464 }
465
466 if (!pac_data) {
467 DEBUG(1,("no PAC\n"));
468 status = NT_STATUS_INVALID_PARAMETER;
469 goto out;
470 }
471
472 *pac_ret = pac_data;
473
474 out:
475 if (cc != cache_name) {
476 ads_kdestroy(cc);
477 }
478
479 data_blob_free(&tkt);
480 data_blob_free(&ap_rep);
481 data_blob_free(&sesskey1);
482 data_blob_free(&sesskey2);
483
484 TALLOC_FREE(client_princ_out);
485
486 return status;
487 }
488
489 /****************************************************************
490 ****************************************************************/
491
492 static NTSTATUS kerberos_return_pac_logon_info(TALLOC_CTX *mem_ctx,
493 const char *name,
494 const char *pass,
495 time_t time_offset,
496 time_t *expire_time,
497 time_t *renew_till_time,
498 const char *cache_name,
499 bool request_pac,
500 bool add_netbios_addr,
501 time_t renewable_time,
502 const char *impersonate_princ_s,
503 struct PAC_LOGON_INFO **logon_info)
504 {
505 NTSTATUS status;
506 struct PAC_DATA *pac_data = NULL;
507 struct PAC_LOGON_INFO *info = NULL;
508
509 status = kerberos_return_pac(mem_ctx,
510 name,
511 pass,
512 time_offset,
513 expire_time,
514 renew_till_time,
515 cache_name,
516 request_pac,
517 add_netbios_addr,
518 renewable_time,
519 impersonate_princ_s,
520 &pac_data);
521 if (!NT_STATUS_IS_OK(status)) {
522 return status;
523 }
524
525 if (!pac_data) {
526 DEBUG(3,("no pac\n"));
527 return NT_STATUS_INVALID_USER_BUFFER;
528 }
529
530 info = get_logon_info_from_pac(pac_data);
531 if (!info) {
532 DEBUG(1,("no logon_info\n"));
533 return NT_STATUS_INVALID_USER_BUFFER;
534 }
535
536 *logon_info = info;
537
538 return NT_STATUS_OK;
539 }
540
541 /****************************************************************
542 ****************************************************************/
543
544 NTSTATUS kerberos_return_info3_from_pac(TALLOC_CTX *mem_ctx,
545 const char *name,
546 const char *pass,
547 time_t time_offset,
548 time_t *expire_time,
549 time_t *renew_till_time,
550 const char *cache_name,
551 bool request_pac,
552 bool add_netbios_addr,
553 time_t renewable_time,
554 const char *impersonate_princ_s,
555 struct netr_SamInfo3 **info3)
556 {
557 NTSTATUS status;
558 struct PAC_LOGON_INFO *logon_info = NULL;
559
560 status = kerberos_return_pac_logon_info(mem_ctx,
561 name,
562 pass,
563 time_offset,
564 expire_time,
565 renew_till_time,
566 cache_name,
567 request_pac,
568 add_netbios_addr,
569 renewable_time,
570 impersonate_princ_s,
571 &logon_info);
572 if (!NT_STATUS_IS_OK(status)) {
573 return status;
574 }
575
576 *info3 = &logon_info->info3;
577
578 return NT_STATUS_OK;
579 }
580 #endif