2 Unix SMB/CIFS implementation.
4 Create and parse the krb5 PAC
6 Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
7 Copyright (C) Andrew Tridgell 2001
8 Copyright (C) Luke Howard 2002-2003
9 Copyright (C) Stefan Metzmacher 2004-2005
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.
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.
22 You should have received a copy of the GNU General Public License
23 along with this program. If not, see <http://www.gnu.org/licenses/>.
27 #include "system/kerberos.h"
28 #include "auth/kerberos/kerberos.h"
29 #include "librpc/gen_ndr/ndr_krb5pac.h"
30 #include "lib/ldb/include/ldb.h"
31 #include "auth/auth_sam.h"
33 static krb5_error_code check_pac_checksum(TALLOC_CTX *mem_ctx,
35 struct PAC_SIGNATURE_DATA *sig,
37 const krb5_keyblock *keyblock)
43 cksum.cksumtype = (CKSUMTYPE)sig->type;
44 cksum.checksum.length = sig->signature.length;
45 cksum.checksum.data = sig->signature.data;
47 ret = krb5_crypto_init(context,
52 DEBUG(0,("krb5_crypto_init() failed: %s\n",
53 smb_get_krb5_error_message(context, ret, mem_ctx)));
56 ret = krb5_verify_checksum(context,
62 krb5_crypto_destroy(context, crypto);
67 NTSTATUS kerberos_decode_pac(TALLOC_CTX *mem_ctx,
68 struct PAC_DATA **pac_data_out,
71 const krb5_keyblock *krbtgt_keyblock,
72 const krb5_keyblock *service_keyblock,
73 krb5_const_principal client_principal,
75 krb5_error_code *k5ret)
79 struct PAC_SIGNATURE_DATA *srv_sig_ptr = NULL;
80 struct PAC_SIGNATURE_DATA *kdc_sig_ptr = NULL;
81 struct PAC_SIGNATURE_DATA *srv_sig_wipe = NULL;
82 struct PAC_SIGNATURE_DATA *kdc_sig_wipe = NULL;
83 struct PAC_LOGON_INFO *logon_info = NULL;
84 struct PAC_LOGON_NAME *logon_name = NULL;
85 struct PAC_DATA *pac_data;
86 struct PAC_DATA_RAW *pac_data_raw;
88 DATA_BLOB *srv_sig_blob = NULL;
89 DATA_BLOB *kdc_sig_blob = NULL;
91 DATA_BLOB modified_pac_blob;
92 NTTIME tgs_authtime_nttime;
93 krb5_principal client_principal_pac;
96 krb5_clear_error_string(context);
99 *k5ret = KRB5_PARSE_MALFORMED;
102 pac_data = talloc(mem_ctx, struct PAC_DATA);
103 pac_data_raw = talloc(mem_ctx, struct PAC_DATA_RAW);
104 kdc_sig_wipe = talloc(mem_ctx, struct PAC_SIGNATURE_DATA);
105 srv_sig_wipe = talloc(mem_ctx, struct PAC_SIGNATURE_DATA);
106 if (!pac_data_raw || !pac_data || !kdc_sig_wipe || !srv_sig_wipe) {
110 return NT_STATUS_NO_MEMORY;
113 status = ndr_pull_struct_blob(&blob, pac_data, pac_data,
114 (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
115 if (!NT_STATUS_IS_OK(status)) {
116 DEBUG(0,("can't parse the PAC\n"));
120 if (pac_data->num_buffers < 4) {
121 /* we need logon_ingo, service_key and kdc_key */
122 DEBUG(0,("less than 4 PAC buffers\n"));
123 return NT_STATUS_INVALID_PARAMETER;
126 status = ndr_pull_struct_blob(&blob, pac_data_raw, pac_data_raw,
127 (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA_RAW);
128 if (!NT_STATUS_IS_OK(status)) {
129 DEBUG(0,("can't parse the PAC\n"));
133 if (pac_data_raw->num_buffers < 4) {
134 /* we need logon_ingo, service_key and kdc_key */
135 DEBUG(0,("less than 4 PAC buffers\n"));
136 return NT_STATUS_INVALID_PARAMETER;
139 if (pac_data->num_buffers != pac_data_raw->num_buffers) {
140 /* we need logon_ingo, service_key and kdc_key */
141 DEBUG(0,("misparse! PAC_DATA has %d buffers while PAC_DATA_RAW has %d\n",
142 pac_data->num_buffers, pac_data_raw->num_buffers));
143 return NT_STATUS_INVALID_PARAMETER;
146 for (i=0; i < pac_data->num_buffers; i++) {
147 if (pac_data->buffers[i].type != pac_data_raw->buffers[i].type) {
148 DEBUG(0,("misparse! PAC_DATA buffer %d has type %d while PAC_DATA_RAW has %d\n",
149 i, pac_data->buffers[i].type, pac_data->buffers[i].type));
150 return NT_STATUS_INVALID_PARAMETER;
152 switch (pac_data->buffers[i].type) {
153 case PAC_TYPE_LOGON_INFO:
154 if (!pac_data->buffers[i].info) {
157 logon_info = pac_data->buffers[i].info->logon_info.info;
159 case PAC_TYPE_SRV_CHECKSUM:
160 if (!pac_data->buffers[i].info) {
163 srv_sig_ptr = &pac_data->buffers[i].info->srv_cksum;
164 srv_sig_blob = &pac_data_raw->buffers[i].info->remaining;
166 case PAC_TYPE_KDC_CHECKSUM:
167 if (!pac_data->buffers[i].info) {
170 kdc_sig_ptr = &pac_data->buffers[i].info->kdc_cksum;
171 kdc_sig_blob = &pac_data_raw->buffers[i].info->remaining;
173 case PAC_TYPE_LOGON_NAME:
174 logon_name = &pac_data->buffers[i].info->logon_name;
182 DEBUG(0,("PAC no logon_info\n"));
183 return NT_STATUS_INVALID_PARAMETER;
187 DEBUG(0,("PAC no logon_name\n"));
188 return NT_STATUS_INVALID_PARAMETER;
191 if (!srv_sig_ptr || !srv_sig_blob) {
192 DEBUG(0,("PAC no srv_key\n"));
193 return NT_STATUS_INVALID_PARAMETER;
196 if (!kdc_sig_ptr || !kdc_sig_blob) {
197 DEBUG(0,("PAC no kdc_key\n"));
198 return NT_STATUS_INVALID_PARAMETER;
201 /* Find and zero out the signatures, as required by the signing algorithm */
203 /* We find the data blobs above, now we parse them to get at the exact portion we should zero */
204 status = ndr_pull_struct_blob(kdc_sig_blob, kdc_sig_wipe, kdc_sig_wipe,
205 (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
206 if (!NT_STATUS_IS_OK(status)) {
207 DEBUG(0,("can't parse the KDC signature\n"));
211 status = ndr_pull_struct_blob(srv_sig_blob, srv_sig_wipe, srv_sig_wipe,
212 (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
213 if (!NT_STATUS_IS_OK(status)) {
214 DEBUG(0,("can't parse the SRV signature\n"));
218 /* Now zero the decoded structure */
219 memset(kdc_sig_wipe->signature.data, '\0', kdc_sig_wipe->signature.length);
220 memset(srv_sig_wipe->signature.data, '\0', srv_sig_wipe->signature.length);
222 /* and reencode, back into the same place it came from */
223 status = ndr_push_struct_blob(kdc_sig_blob, pac_data_raw, kdc_sig_wipe,
224 (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
225 if (!NT_STATUS_IS_OK(status)) {
226 DEBUG(0,("can't repack the KDC signature\n"));
229 status = ndr_push_struct_blob(srv_sig_blob, pac_data_raw, srv_sig_wipe,
230 (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
231 if (!NT_STATUS_IS_OK(status)) {
232 DEBUG(0,("can't repack the SRV signature\n"));
236 /* push out the whole structure, but now with zero'ed signatures */
237 status = ndr_push_struct_blob(&modified_pac_blob, pac_data_raw, pac_data_raw,
238 (ndr_push_flags_fn_t)ndr_push_PAC_DATA_RAW);
239 if (!NT_STATUS_IS_OK(status)) {
240 DEBUG(0,("can't repack the RAW PAC\n"));
244 /* verify by service_key */
245 ret = check_pac_checksum(mem_ctx,
246 modified_pac_blob, srv_sig_ptr,
250 DEBUG(1, ("PAC Decode: Failed to verify the service signature: %s\n",
251 smb_get_krb5_error_message(context, ret, mem_ctx)));
255 return NT_STATUS_ACCESS_DENIED;
258 if (krbtgt_keyblock) {
259 ret = check_pac_checksum(mem_ctx,
260 srv_sig_ptr->signature, kdc_sig_ptr,
261 context, krbtgt_keyblock);
263 DEBUG(1, ("PAC Decode: Failed to verify the KDC signature: %s\n",
264 smb_get_krb5_error_message(context, ret, mem_ctx)));
268 return NT_STATUS_ACCESS_DENIED;
272 /* Convert to NT time, so as not to loose accuracy in comparison */
273 unix_to_nt_time(&tgs_authtime_nttime, tgs_authtime);
275 if (tgs_authtime_nttime != logon_name->logon_time) {
276 DEBUG(2, ("PAC Decode: Logon time mismatch between ticket and PAC!\n"));
277 DEBUG(2, ("PAC Decode: PAC: %s\n", nt_time_string(mem_ctx, logon_name->logon_time)));
278 DEBUG(2, ("PAC Decode: Ticket: %s\n", nt_time_string(mem_ctx, tgs_authtime_nttime)));
279 return NT_STATUS_ACCESS_DENIED;
282 ret = krb5_parse_name_flags(context, logon_name->account_name, KRB5_PRINCIPAL_PARSE_NO_REALM,
283 &client_principal_pac);
285 DEBUG(2, ("Could not parse name from incoming PAC: [%s]: %s\n",
286 logon_name->account_name,
287 smb_get_krb5_error_message(context, ret, mem_ctx)));
291 return NT_STATUS_INVALID_PARAMETER;
294 if (!krb5_principal_compare_any_realm(context, client_principal, client_principal_pac)) {
295 DEBUG(2, ("Name in PAC [%s] does not match principal name in ticket\n",
296 logon_name->account_name));
297 return NT_STATUS_ACCESS_DENIED;
301 if (strcasecmp(logon_info->info3.base.account_name.string,
302 "Administrator")== 0) {
303 file_save("tmp_pac_data-admin.dat",blob.data,blob.length);
307 DEBUG(3,("Found account name from PAC: %s [%s]\n",
308 logon_info->info3.base.account_name.string,
309 logon_info->info3.base.full_name.string));
310 *pac_data_out = pac_data;
315 _PUBLIC_ NTSTATUS kerberos_pac_logon_info(TALLOC_CTX *mem_ctx,
316 struct PAC_LOGON_INFO **logon_info,
318 krb5_context context,
319 const krb5_keyblock *krbtgt_keyblock,
320 const krb5_keyblock *service_keyblock,
321 krb5_const_principal client_principal,
323 krb5_error_code *k5ret)
326 struct PAC_DATA *pac_data;
328 nt_status = kerberos_decode_pac(mem_ctx, &pac_data,
336 if (!NT_STATUS_IS_OK(nt_status)) {
341 for (i=0; i < pac_data->num_buffers; i++) {
342 if (pac_data->buffers[i].type != PAC_TYPE_LOGON_INFO) {
345 *logon_info = pac_data->buffers[i].info->logon_info.info;
348 return NT_STATUS_INVALID_PARAMETER;
353 static krb5_error_code make_pac_checksum(TALLOC_CTX *mem_ctx,
355 struct PAC_SIGNATURE_DATA *sig,
356 krb5_context context,
357 const krb5_keyblock *keyblock)
364 ret = krb5_crypto_init(context,
369 DEBUG(0,("krb5_crypto_init() failed: %s\n",
370 smb_get_krb5_error_message(context, ret, mem_ctx)));
373 ret = krb5_create_checksum(context,
381 DEBUG(2, ("PAC Verification failed: %s\n",
382 smb_get_krb5_error_message(context, ret, mem_ctx)));
385 krb5_crypto_destroy(context, crypto);
391 sig->type = cksum.cksumtype;
392 sig->signature = data_blob_talloc(mem_ctx, cksum.checksum.data, cksum.checksum.length);
393 free_Checksum(&cksum);
398 krb5_error_code kerberos_encode_pac(TALLOC_CTX *mem_ctx,
399 struct PAC_DATA *pac_data,
400 krb5_context context,
401 const krb5_keyblock *krbtgt_keyblock,
402 const krb5_keyblock *service_keyblock,
407 DATA_BLOB zero_blob = data_blob(NULL, 0);
408 DATA_BLOB tmp_blob = data_blob(NULL, 0);
409 struct PAC_SIGNATURE_DATA *kdc_checksum = NULL;
410 struct PAC_SIGNATURE_DATA *srv_checksum = NULL;
413 /* First, just get the keytypes filled in (and lengths right, eventually) */
414 for (i=0; i < pac_data->num_buffers; i++) {
415 if (pac_data->buffers[i].type != PAC_TYPE_KDC_CHECKSUM) {
418 kdc_checksum = &pac_data->buffers[i].info->kdc_cksum,
419 ret = make_pac_checksum(mem_ctx, &zero_blob,
421 context, krbtgt_keyblock);
423 DEBUG(2, ("making krbtgt PAC checksum failed: %s\n",
424 smb_get_krb5_error_message(context, ret, mem_ctx)));
425 talloc_free(pac_data);
430 for (i=0; i < pac_data->num_buffers; i++) {
431 if (pac_data->buffers[i].type != PAC_TYPE_SRV_CHECKSUM) {
434 srv_checksum = &pac_data->buffers[i].info->srv_cksum;
435 ret = make_pac_checksum(mem_ctx, &zero_blob,
437 context, service_keyblock);
439 DEBUG(2, ("making service PAC checksum failed: %s\n",
440 smb_get_krb5_error_message(context, ret, mem_ctx)));
441 talloc_free(pac_data);
447 DEBUG(2, ("Invalid PAC constructed for signing, no KDC checksum present!"));
451 DEBUG(2, ("Invalid PAC constructed for signing, no SRV checksum present!"));
455 /* But wipe out the actual signatures */
456 memset(kdc_checksum->signature.data, '\0', kdc_checksum->signature.length);
457 memset(srv_checksum->signature.data, '\0', srv_checksum->signature.length);
459 nt_status = ndr_push_struct_blob(&tmp_blob, mem_ctx, pac_data,
460 (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
461 if (!NT_STATUS_IS_OK(nt_status)) {
462 DEBUG(1, ("PAC (presig) push failed: %s\n", nt_errstr(nt_status)));
463 talloc_free(pac_data);
467 /* Then sign the result of the previous push, where the sig was zero'ed out */
468 ret = make_pac_checksum(mem_ctx, &tmp_blob, srv_checksum,
469 context, service_keyblock);
471 /* Then sign Server checksum */
472 ret = make_pac_checksum(mem_ctx, &srv_checksum->signature, kdc_checksum, context, krbtgt_keyblock);
474 DEBUG(2, ("making krbtgt PAC checksum failed: %s\n",
475 smb_get_krb5_error_message(context, ret, mem_ctx)));
476 talloc_free(pac_data);
480 /* And push it out again, this time to the world. This relies on determanistic pointer values */
481 nt_status = ndr_push_struct_blob(&tmp_blob, mem_ctx, pac_data,
482 (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
483 if (!NT_STATUS_IS_OK(nt_status)) {
484 DEBUG(1, ("PAC (final) push failed: %s\n", nt_errstr(nt_status)));
485 talloc_free(pac_data);
495 krb5_error_code kerberos_create_pac(TALLOC_CTX *mem_ctx,
496 struct auth_serversupplied_info *server_info,
497 krb5_context context,
498 const krb5_keyblock *krbtgt_keyblock,
499 const krb5_keyblock *service_keyblock,
500 krb5_principal client_principal,
506 struct PAC_DATA *pac_data = talloc(mem_ctx, struct PAC_DATA);
507 struct netr_SamInfo3 *sam3;
508 union PAC_INFO *u_LOGON_INFO;
509 struct PAC_LOGON_INFO *LOGON_INFO;
510 union PAC_INFO *u_LOGON_NAME;
511 struct PAC_LOGON_NAME *LOGON_NAME;
512 union PAC_INFO *u_KDC_CHECKSUM;
513 union PAC_INFO *u_SRV_CHECKSUM;
518 PAC_BUF_LOGON_INFO = 0,
519 PAC_BUF_LOGON_NAME = 1,
520 PAC_BUF_SRV_CHECKSUM = 2,
521 PAC_BUF_KDC_CHECKSUM = 3,
522 PAC_BUF_NUM_BUFFERS = 4
529 pac_data->num_buffers = PAC_BUF_NUM_BUFFERS;
530 pac_data->version = 0;
532 pac_data->buffers = talloc_array(pac_data,
534 pac_data->num_buffers);
535 if (!pac_data->buffers) {
536 talloc_free(pac_data);
541 u_LOGON_INFO = talloc_zero(pac_data->buffers, union PAC_INFO);
543 talloc_free(pac_data);
546 pac_data->buffers[PAC_BUF_LOGON_INFO].type = PAC_TYPE_LOGON_INFO;
547 pac_data->buffers[PAC_BUF_LOGON_INFO].info = u_LOGON_INFO;
550 u_LOGON_NAME = talloc_zero(pac_data->buffers, union PAC_INFO);
552 talloc_free(pac_data);
555 pac_data->buffers[PAC_BUF_LOGON_NAME].type = PAC_TYPE_LOGON_NAME;
556 pac_data->buffers[PAC_BUF_LOGON_NAME].info = u_LOGON_NAME;
557 LOGON_NAME = &u_LOGON_NAME->logon_name;
560 u_SRV_CHECKSUM = talloc_zero(pac_data->buffers, union PAC_INFO);
561 if (!u_SRV_CHECKSUM) {
562 talloc_free(pac_data);
565 pac_data->buffers[PAC_BUF_SRV_CHECKSUM].type = PAC_TYPE_SRV_CHECKSUM;
566 pac_data->buffers[PAC_BUF_SRV_CHECKSUM].info = u_SRV_CHECKSUM;
569 u_KDC_CHECKSUM = talloc_zero(pac_data->buffers, union PAC_INFO);
570 if (!u_KDC_CHECKSUM) {
571 talloc_free(pac_data);
574 pac_data->buffers[PAC_BUF_KDC_CHECKSUM].type = PAC_TYPE_KDC_CHECKSUM;
575 pac_data->buffers[PAC_BUF_KDC_CHECKSUM].info = u_KDC_CHECKSUM;
577 /* now the real work begins... */
579 LOGON_INFO = talloc_zero(u_LOGON_INFO, struct PAC_LOGON_INFO);
581 talloc_free(pac_data);
584 nt_status = auth_convert_server_info_saminfo3(LOGON_INFO, server_info, &sam3);
585 if (!NT_STATUS_IS_OK(nt_status)) {
586 DEBUG(1, ("Getting Samba info failed: %s\n", nt_errstr(nt_status)));
587 talloc_free(pac_data);
591 u_LOGON_INFO->logon_info.info = LOGON_INFO;
592 LOGON_INFO->info3 = *sam3;
594 ret = krb5_unparse_name_flags(context, client_principal,
595 KRB5_PRINCIPAL_UNPARSE_NO_REALM, &name);
599 LOGON_NAME->account_name = talloc_strdup(LOGON_NAME, name);
602 this logon_time field is absolutely critical. This is what
603 caused all our PAC troubles :-)
605 unix_to_nt_time(&LOGON_NAME->logon_time, tgs_authtime);
607 ret = kerberos_encode_pac(mem_ctx,
613 talloc_free(pac_data);