Line data Source code
1 : /*
2 : Unix SMB/CIFS implementation.
3 :
4 : Create and parse the krb5 PAC
5 :
6 : Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005,2008
7 : Copyright (C) Andrew Tridgell 2001
8 : Copyright (C) Luke Howard 2002-2003
9 : Copyright (C) Stefan Metzmacher 2004-2005
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 :
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/>.
24 : */
25 :
26 : #include "includes.h"
27 : #include "system/kerberos.h"
28 : #include "auth/auth.h"
29 : #include "auth/kerberos/kerberos.h"
30 : #include "librpc/gen_ndr/ndr_krb5pac.h"
31 : #include <ldb.h>
32 : #include "auth/auth_sam_reply.h"
33 : #include "auth/credentials/credentials.h"
34 : #include "auth/kerberos/kerberos_util.h"
35 : #include "auth/kerberos/pac_utils.h"
36 :
37 0 : krb5_error_code kerberos_encode_pac(TALLOC_CTX *mem_ctx,
38 : struct PAC_DATA *pac_data,
39 : krb5_context context,
40 : const krb5_keyblock *krbtgt_keyblock,
41 : const krb5_keyblock *service_keyblock,
42 : DATA_BLOB *pac)
43 : {
44 : NTSTATUS nt_status;
45 : krb5_error_code ret;
46 : enum ndr_err_code ndr_err;
47 0 : DATA_BLOB zero_blob = data_blob(NULL, 0);
48 0 : DATA_BLOB tmp_blob = data_blob(NULL, 0);
49 0 : struct PAC_SIGNATURE_DATA *kdc_checksum = NULL;
50 0 : struct PAC_SIGNATURE_DATA *srv_checksum = NULL;
51 : uint32_t i;
52 :
53 : /* First, just get the keytypes filled in (and lengths right, eventually) */
54 0 : for (i=0; i < pac_data->num_buffers; i++) {
55 0 : if (pac_data->buffers[i].type != PAC_TYPE_KDC_CHECKSUM) {
56 0 : continue;
57 : }
58 0 : kdc_checksum = &pac_data->buffers[i].info->kdc_cksum,
59 0 : ret = smb_krb5_make_pac_checksum(mem_ctx,
60 : &zero_blob,
61 : context,
62 : krbtgt_keyblock,
63 : &kdc_checksum->type,
64 : &kdc_checksum->signature);
65 0 : if (ret) {
66 0 : DEBUG(2, ("making krbtgt PAC checksum failed: %s\n",
67 : smb_get_krb5_error_message(context, ret, mem_ctx)));
68 0 : talloc_free(pac_data);
69 0 : return ret;
70 : }
71 : }
72 :
73 0 : for (i=0; i < pac_data->num_buffers; i++) {
74 0 : if (pac_data->buffers[i].type != PAC_TYPE_SRV_CHECKSUM) {
75 0 : continue;
76 : }
77 0 : srv_checksum = &pac_data->buffers[i].info->srv_cksum;
78 0 : ret = smb_krb5_make_pac_checksum(mem_ctx,
79 : &zero_blob,
80 : context,
81 : service_keyblock,
82 : &srv_checksum->type,
83 : &srv_checksum->signature);
84 0 : if (ret) {
85 0 : DEBUG(2, ("making service PAC checksum failed: %s\n",
86 : smb_get_krb5_error_message(context, ret, mem_ctx)));
87 0 : talloc_free(pac_data);
88 0 : return ret;
89 : }
90 : }
91 :
92 0 : if (!kdc_checksum) {
93 0 : DEBUG(2, ("Invalid PAC constructed for signing, no KDC checksum present!"));
94 0 : return EINVAL;
95 : }
96 0 : if (!srv_checksum) {
97 0 : DEBUG(2, ("Invalid PAC constructed for signing, no SRV checksum present!"));
98 0 : return EINVAL;
99 : }
100 :
101 : /* But wipe out the actual signatures */
102 0 : memset(kdc_checksum->signature.data, '\0', kdc_checksum->signature.length);
103 0 : memset(srv_checksum->signature.data, '\0', srv_checksum->signature.length);
104 :
105 0 : ndr_err = ndr_push_struct_blob(&tmp_blob, mem_ctx,
106 : pac_data,
107 : (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
108 0 : if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
109 0 : nt_status = ndr_map_error2ntstatus(ndr_err);
110 0 : DEBUG(1, ("PAC (presig) push failed: %s\n", nt_errstr(nt_status)));
111 0 : talloc_free(pac_data);
112 0 : return EINVAL;
113 : }
114 :
115 : /* Then sign the result of the previous push, where the sig was zero'ed out */
116 0 : ret = smb_krb5_make_pac_checksum(mem_ctx,
117 : &tmp_blob,
118 : context,
119 : service_keyblock,
120 : &srv_checksum->type,
121 : &srv_checksum->signature);
122 :
123 0 : if (ret) {
124 0 : DBG_WARNING("making krbtgt PAC srv_checksum failed: %s\n",
125 : smb_get_krb5_error_message(context, ret, mem_ctx));
126 0 : talloc_free(pac_data);
127 0 : return ret;
128 : }
129 :
130 : /* Then sign Server checksum */
131 0 : ret = smb_krb5_make_pac_checksum(mem_ctx,
132 : &srv_checksum->signature,
133 : context,
134 : krbtgt_keyblock,
135 : &kdc_checksum->type,
136 : &kdc_checksum->signature);
137 0 : if (ret) {
138 0 : DBG_WARNING("making krbtgt PAC kdc_checksum failed: %s\n",
139 : smb_get_krb5_error_message(context, ret, mem_ctx));
140 0 : talloc_free(pac_data);
141 0 : return ret;
142 : }
143 :
144 : /* And push it out again, this time to the world. This relies on determanistic pointer values */
145 0 : ndr_err = ndr_push_struct_blob(&tmp_blob, mem_ctx,
146 : pac_data,
147 : (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
148 0 : if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
149 0 : nt_status = ndr_map_error2ntstatus(ndr_err);
150 0 : DEBUG(1, ("PAC (final) push failed: %s\n", nt_errstr(nt_status)));
151 0 : talloc_free(pac_data);
152 0 : return EINVAL;
153 : }
154 :
155 0 : *pac = tmp_blob;
156 :
157 0 : return ret;
158 : }
159 :
160 :
161 0 : krb5_error_code kerberos_create_pac(TALLOC_CTX *mem_ctx,
162 : struct auth_user_info_dc *user_info_dc,
163 : krb5_context context,
164 : const krb5_keyblock *krbtgt_keyblock,
165 : const krb5_keyblock *service_keyblock,
166 : krb5_principal client_principal,
167 : time_t tgs_authtime,
168 : DATA_BLOB *pac)
169 : {
170 : NTSTATUS nt_status;
171 : krb5_error_code ret;
172 0 : struct PAC_DATA *pac_data = talloc(mem_ctx, struct PAC_DATA);
173 : struct netr_SamInfo3 *sam3;
174 : union PAC_INFO *u_LOGON_INFO;
175 : struct PAC_LOGON_INFO *LOGON_INFO;
176 : union PAC_INFO *u_LOGON_NAME;
177 : struct PAC_LOGON_NAME *LOGON_NAME;
178 : union PAC_INFO *u_KDC_CHECKSUM;
179 : union PAC_INFO *u_SRV_CHECKSUM;
180 :
181 : char *name;
182 :
183 : enum {
184 : PAC_BUF_LOGON_INFO = 0,
185 : PAC_BUF_LOGON_NAME = 1,
186 : PAC_BUF_SRV_CHECKSUM = 2,
187 : PAC_BUF_KDC_CHECKSUM = 3,
188 : PAC_BUF_NUM_BUFFERS = 4
189 : };
190 :
191 0 : if (!pac_data) {
192 0 : return ENOMEM;
193 : }
194 :
195 0 : pac_data->num_buffers = PAC_BUF_NUM_BUFFERS;
196 0 : pac_data->version = 0;
197 :
198 0 : pac_data->buffers = talloc_array(pac_data,
199 : struct PAC_BUFFER,
200 : pac_data->num_buffers);
201 0 : if (!pac_data->buffers) {
202 0 : talloc_free(pac_data);
203 0 : return ENOMEM;
204 : }
205 :
206 : /* LOGON_INFO */
207 0 : u_LOGON_INFO = talloc_zero(pac_data->buffers, union PAC_INFO);
208 0 : if (!u_LOGON_INFO) {
209 0 : talloc_free(pac_data);
210 0 : return ENOMEM;
211 : }
212 0 : pac_data->buffers[PAC_BUF_LOGON_INFO].type = PAC_TYPE_LOGON_INFO;
213 0 : pac_data->buffers[PAC_BUF_LOGON_INFO].info = u_LOGON_INFO;
214 :
215 : /* LOGON_NAME */
216 0 : u_LOGON_NAME = talloc_zero(pac_data->buffers, union PAC_INFO);
217 0 : if (!u_LOGON_NAME) {
218 0 : talloc_free(pac_data);
219 0 : return ENOMEM;
220 : }
221 0 : pac_data->buffers[PAC_BUF_LOGON_NAME].type = PAC_TYPE_LOGON_NAME;
222 0 : pac_data->buffers[PAC_BUF_LOGON_NAME].info = u_LOGON_NAME;
223 0 : LOGON_NAME = &u_LOGON_NAME->logon_name;
224 :
225 : /* SRV_CHECKSUM */
226 0 : u_SRV_CHECKSUM = talloc_zero(pac_data->buffers, union PAC_INFO);
227 0 : if (!u_SRV_CHECKSUM) {
228 0 : talloc_free(pac_data);
229 0 : return ENOMEM;
230 : }
231 0 : pac_data->buffers[PAC_BUF_SRV_CHECKSUM].type = PAC_TYPE_SRV_CHECKSUM;
232 0 : pac_data->buffers[PAC_BUF_SRV_CHECKSUM].info = u_SRV_CHECKSUM;
233 :
234 : /* KDC_CHECKSUM */
235 0 : u_KDC_CHECKSUM = talloc_zero(pac_data->buffers, union PAC_INFO);
236 0 : if (!u_KDC_CHECKSUM) {
237 0 : talloc_free(pac_data);
238 0 : return ENOMEM;
239 : }
240 0 : pac_data->buffers[PAC_BUF_KDC_CHECKSUM].type = PAC_TYPE_KDC_CHECKSUM;
241 0 : pac_data->buffers[PAC_BUF_KDC_CHECKSUM].info = u_KDC_CHECKSUM;
242 :
243 : /* now the real work begins... */
244 :
245 0 : LOGON_INFO = talloc_zero(u_LOGON_INFO, struct PAC_LOGON_INFO);
246 0 : if (!LOGON_INFO) {
247 0 : talloc_free(pac_data);
248 0 : return ENOMEM;
249 : }
250 0 : nt_status = auth_convert_user_info_dc_saminfo3(LOGON_INFO, user_info_dc, &sam3);
251 0 : if (!NT_STATUS_IS_OK(nt_status)) {
252 0 : DEBUG(1, ("Getting Samba info failed: %s\n", nt_errstr(nt_status)));
253 0 : talloc_free(pac_data);
254 0 : return EINVAL;
255 : }
256 :
257 0 : u_LOGON_INFO->logon_info.info = LOGON_INFO;
258 0 : LOGON_INFO->info3 = *sam3;
259 :
260 0 : ret = krb5_unparse_name_flags(context, client_principal,
261 : KRB5_PRINCIPAL_UNPARSE_NO_REALM |
262 : KRB5_PRINCIPAL_UNPARSE_DISPLAY,
263 : &name);
264 0 : if (ret) {
265 0 : return ret;
266 : }
267 0 : LOGON_NAME->account_name = talloc_strdup(LOGON_NAME, name);
268 0 : free(name);
269 : /*
270 : this logon_time field is absolutely critical. This is what
271 : caused all our PAC troubles :-)
272 : */
273 0 : unix_to_nt_time(&LOGON_NAME->logon_time, tgs_authtime);
274 :
275 0 : ret = kerberos_encode_pac(mem_ctx,
276 : pac_data,
277 : context,
278 : krbtgt_keyblock,
279 : service_keyblock,
280 : pac);
281 0 : talloc_free(pac_data);
282 0 : return ret;
283 : }
284 :
285 59086 : static krb5_error_code kerberos_pac_buffer_present(krb5_context context,
286 : const krb5_pac pac,
287 : uint32_t type)
288 : {
289 : #ifdef SAMBA4_USES_HEIMDAL
290 55037 : return krb5_pac_get_buffer(context, pac, type, NULL);
291 : #else /* MIT */
292 : krb5_error_code ret;
293 : krb5_data data;
294 :
295 : /*
296 : * MIT won't let us pass NULL for the data parameter, so we are forced
297 : * to allocate a new buffer and then immediately free it.
298 : */
299 4049 : ret = krb5_pac_get_buffer(context, pac, type, &data);
300 4049 : if (ret == 0) {
301 0 : krb5_free_data_contents(context, &data);
302 : }
303 4049 : return ret;
304 : #endif /* SAMBA4_USES_HEIMDAL */
305 : }
306 :
307 59086 : krb5_error_code kerberos_pac_to_user_info_dc(TALLOC_CTX *mem_ctx,
308 : krb5_pac pac,
309 : krb5_context context,
310 : struct auth_user_info_dc **user_info_dc,
311 : struct PAC_SIGNATURE_DATA *pac_srv_sig,
312 : struct PAC_SIGNATURE_DATA *pac_kdc_sig)
313 : {
314 : NTSTATUS nt_status;
315 : enum ndr_err_code ndr_err;
316 : krb5_error_code ret;
317 :
318 : DATA_BLOB pac_logon_info_in, pac_srv_checksum_in, pac_kdc_checksum_in;
319 : krb5_data k5pac_logon_info_in, k5pac_srv_checksum_in, k5pac_kdc_checksum_in;
320 : DATA_BLOB pac_upn_dns_info_in;
321 : krb5_data k5pac_upn_dns_info_in;
322 :
323 : union PAC_INFO info;
324 : union PAC_INFO _upn_dns_info;
325 59086 : struct PAC_UPN_DNS_INFO *upn_dns_info = NULL;
326 : struct auth_user_info_dc *user_info_dc_out;
327 :
328 59086 : TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
329 :
330 59086 : if (!tmp_ctx) {
331 0 : return ENOMEM;
332 : }
333 :
334 59086 : ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_LOGON_INFO, &k5pac_logon_info_in);
335 59086 : if (ret != 0) {
336 0 : talloc_free(tmp_ctx);
337 0 : return EINVAL;
338 : }
339 :
340 59086 : pac_logon_info_in = data_blob_const(k5pac_logon_info_in.data, k5pac_logon_info_in.length);
341 :
342 59086 : ndr_err = ndr_pull_union_blob(&pac_logon_info_in, tmp_ctx, &info,
343 : PAC_TYPE_LOGON_INFO,
344 : (ndr_pull_flags_fn_t)ndr_pull_PAC_INFO);
345 59086 : smb_krb5_free_data_contents(context, &k5pac_logon_info_in);
346 59086 : if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
347 0 : nt_status = ndr_map_error2ntstatus(ndr_err);
348 0 : DEBUG(0,("can't parse the PAC LOGON_INFO: %s\n", nt_errstr(nt_status)));
349 0 : talloc_free(tmp_ctx);
350 0 : return EINVAL;
351 : }
352 59086 : if (info.logon_info.info == NULL) {
353 0 : DEBUG(0,("can't parse the PAC LOGON_INFO: missing info pointer\n"));
354 0 : talloc_free(tmp_ctx);
355 0 : return EINVAL;
356 : }
357 :
358 59086 : ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_UPN_DNS_INFO,
359 : &k5pac_upn_dns_info_in);
360 59086 : if (ret == ENOENT) {
361 0 : ZERO_STRUCT(k5pac_upn_dns_info_in);
362 0 : ret = 0;
363 : }
364 59086 : if (ret != 0) {
365 0 : talloc_free(tmp_ctx);
366 0 : return EINVAL;
367 : }
368 :
369 59086 : pac_upn_dns_info_in = data_blob_const(k5pac_upn_dns_info_in.data,
370 4049 : k5pac_upn_dns_info_in.length);
371 :
372 59086 : if (pac_upn_dns_info_in.length != 0) {
373 59086 : ndr_err = ndr_pull_union_blob(&pac_upn_dns_info_in, tmp_ctx,
374 : &_upn_dns_info,
375 : PAC_TYPE_UPN_DNS_INFO,
376 : (ndr_pull_flags_fn_t)ndr_pull_PAC_INFO);
377 59086 : smb_krb5_free_data_contents(context, &k5pac_upn_dns_info_in);
378 59086 : if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
379 0 : nt_status = ndr_map_error2ntstatus(ndr_err);
380 0 : DEBUG(0,("can't parse the PAC UPN_DNS_INFO: %s\n",
381 : nt_errstr(nt_status)));
382 0 : talloc_free(tmp_ctx);
383 0 : return EINVAL;
384 : }
385 59086 : upn_dns_info = &_upn_dns_info.upn_dns_info;
386 : }
387 :
388 : /* Pull this right into the normal auth sysstem structures */
389 59086 : nt_status = make_user_info_dc_pac(mem_ctx,
390 59086 : info.logon_info.info,
391 : upn_dns_info,
392 : &user_info_dc_out);
393 59086 : if (!NT_STATUS_IS_OK(nt_status)) {
394 0 : DBG_ERR("make_user_info_dc_pac() failed -%s\n",
395 : nt_errstr(nt_status));
396 0 : NDR_PRINT_DEBUG(PAC_LOGON_INFO, info.logon_info.info);
397 0 : if (upn_dns_info != NULL) {
398 0 : NDR_PRINT_DEBUG(PAC_UPN_DNS_INFO, upn_dns_info);
399 : }
400 0 : talloc_free(tmp_ctx);
401 0 : return EINVAL;
402 : }
403 :
404 59086 : if (pac_srv_sig) {
405 72 : ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_SRV_CHECKSUM, &k5pac_srv_checksum_in);
406 72 : if (ret != 0) {
407 0 : talloc_free(tmp_ctx);
408 0 : return ret;
409 : }
410 :
411 72 : pac_srv_checksum_in = data_blob_const(k5pac_srv_checksum_in.data, k5pac_srv_checksum_in.length);
412 :
413 72 : ndr_err = ndr_pull_struct_blob(&pac_srv_checksum_in, pac_srv_sig,
414 : pac_srv_sig,
415 : (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
416 72 : smb_krb5_free_data_contents(context, &k5pac_srv_checksum_in);
417 72 : if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
418 0 : nt_status = ndr_map_error2ntstatus(ndr_err);
419 0 : DEBUG(0,("can't parse the KDC signature: %s\n",
420 : nt_errstr(nt_status)));
421 0 : return EINVAL;
422 : }
423 : }
424 :
425 59086 : if (pac_kdc_sig) {
426 72 : ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_KDC_CHECKSUM, &k5pac_kdc_checksum_in);
427 72 : if (ret != 0) {
428 0 : talloc_free(tmp_ctx);
429 0 : return ret;
430 : }
431 :
432 72 : pac_kdc_checksum_in = data_blob_const(k5pac_kdc_checksum_in.data, k5pac_kdc_checksum_in.length);
433 :
434 72 : ndr_err = ndr_pull_struct_blob(&pac_kdc_checksum_in, pac_kdc_sig,
435 : pac_kdc_sig,
436 : (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
437 72 : smb_krb5_free_data_contents(context, &k5pac_kdc_checksum_in);
438 72 : if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
439 0 : nt_status = ndr_map_error2ntstatus(ndr_err);
440 0 : DEBUG(0,("can't parse the KDC signature: %s\n",
441 : nt_errstr(nt_status)));
442 0 : return EINVAL;
443 : }
444 : }
445 :
446 : /*
447 : * Based on the presence of a REQUESTER_SID PAC buffer, ascertain
448 : * whether the ticket is a TGT. This helps the KDC and kpasswd service
449 : * ensure they do not accept tickets meant for the other.
450 : *
451 : * This heuristic will fail for older Samba versions and Windows prior
452 : * to Nov. 2021 updates, which lack support for the REQUESTER_SID PAC
453 : * buffer.
454 : */
455 59086 : ret = kerberos_pac_buffer_present(context, pac, PAC_TYPE_REQUESTER_SID);
456 59086 : if (ret == ENOENT) {
457 : /* This probably isn't a TGT. */
458 23169 : user_info_dc_out->ticket_type = TICKET_TYPE_NON_TGT;
459 35917 : } else if (ret != 0) {
460 0 : talloc_free(tmp_ctx);
461 0 : return ret;
462 : } else {
463 : /* This probably is a TGT. */
464 35917 : user_info_dc_out->ticket_type = TICKET_TYPE_TGT;
465 : }
466 :
467 59086 : *user_info_dc = user_info_dc_out;
468 :
469 59086 : return 0;
470 : }
471 :
472 :
473 23068 : NTSTATUS kerberos_pac_blob_to_user_info_dc(TALLOC_CTX *mem_ctx,
474 : DATA_BLOB pac_blob,
475 : krb5_context context,
476 : struct auth_user_info_dc **user_info_dc,
477 : struct PAC_SIGNATURE_DATA *pac_srv_sig,
478 : struct PAC_SIGNATURE_DATA *pac_kdc_sig)
479 : {
480 : krb5_error_code ret;
481 : krb5_pac pac;
482 42087 : ret = krb5_pac_parse(context,
483 23068 : pac_blob.data, pac_blob.length,
484 : &pac);
485 23068 : if (ret) {
486 0 : return map_nt_error_from_unix_common(ret);
487 : }
488 :
489 :
490 23068 : ret = kerberos_pac_to_user_info_dc(mem_ctx, pac, context, user_info_dc, pac_srv_sig, pac_kdc_sig);
491 23068 : krb5_pac_free(context, pac);
492 23068 : if (ret) {
493 0 : return map_nt_error_from_unix_common(ret);
494 : }
495 23068 : return NT_STATUS_OK;
496 : }
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