summaryrefslogtreecommitdiff
path: root/source4/auth/kerberos/kerberos_pac.c
blob: 76c1d99d916f6c32a33c7cff33328bfbe6a464c2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
/*
   Unix SMB/CIFS implementation.

   Create and parse the krb5 PAC

   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005,2008
   Copyright (C) Andrew Tridgell 2001
   Copyright (C) Luke Howard 2002-2003
   Copyright (C) Stefan Metzmacher 2004-2005

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.


   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "system/kerberos.h"
#include "auth/auth.h"
#include "auth/kerberos/kerberos.h"
#include "librpc/gen_ndr/ndr_krb5pac.h"
#include <ldb.h>
#include "auth/auth_sam_reply.h"
#include "auth/kerberos/kerberos_util.h"
#include "auth/kerberos/pac_utils.h"

 krb5_error_code kerberos_encode_pac(TALLOC_CTX *mem_ctx,
				    struct PAC_DATA *pac_data,
				    krb5_context context,
				    const krb5_keyblock *krbtgt_keyblock,
				    const krb5_keyblock *service_keyblock,
				    DATA_BLOB *pac)
{
	NTSTATUS nt_status;
	krb5_error_code ret;
	enum ndr_err_code ndr_err;
	DATA_BLOB zero_blob = data_blob(NULL, 0);
	DATA_BLOB tmp_blob = data_blob(NULL, 0);
	struct PAC_SIGNATURE_DATA *kdc_checksum = NULL;
	struct PAC_SIGNATURE_DATA *srv_checksum = NULL;
	int i;

	/* First, just get the keytypes filled in (and lengths right, eventually) */
	for (i=0; i < pac_data->num_buffers; i++) {
		if (pac_data->buffers[i].type != PAC_TYPE_KDC_CHECKSUM) {
			continue;
		}
		kdc_checksum = &pac_data->buffers[i].info->kdc_cksum,
		ret = smb_krb5_make_pac_checksum(mem_ctx,
						 &zero_blob,
						 context,
						 krbtgt_keyblock,
						 &kdc_checksum->type,
						 &kdc_checksum->signature);
		if (ret) {
			DEBUG(2, ("making krbtgt PAC checksum failed: %s\n",
				  smb_get_krb5_error_message(context, ret, mem_ctx)));
			talloc_free(pac_data);
			return ret;
		}
	}

	for (i=0; i < pac_data->num_buffers; i++) {
		if (pac_data->buffers[i].type != PAC_TYPE_SRV_CHECKSUM) {
			continue;
		}
		srv_checksum = &pac_data->buffers[i].info->srv_cksum;
		ret = smb_krb5_make_pac_checksum(mem_ctx,
						 &zero_blob,
						 context,
						 service_keyblock,
						 &srv_checksum->type,
						 &srv_checksum->signature);
		if (ret) {
			DEBUG(2, ("making service PAC checksum failed: %s\n",
				  smb_get_krb5_error_message(context, ret, mem_ctx)));
			talloc_free(pac_data);
			return ret;
		}
	}

	if (!kdc_checksum) {
		DEBUG(2, ("Invalid PAC constructed for signing, no KDC checksum present!"));
		return EINVAL;
	}
	if (!srv_checksum) {
		DEBUG(2, ("Invalid PAC constructed for signing, no SRV checksum present!"));
		return EINVAL;
	}

	/* But wipe out the actual signatures */
	memset(kdc_checksum->signature.data, '\0', kdc_checksum->signature.length);
	memset(srv_checksum->signature.data, '\0', srv_checksum->signature.length);

	ndr_err = ndr_push_struct_blob(&tmp_blob, mem_ctx,
				       pac_data,
				       (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		nt_status = ndr_map_error2ntstatus(ndr_err);
		DEBUG(1, ("PAC (presig) push failed: %s\n", nt_errstr(nt_status)));
		talloc_free(pac_data);
		return EINVAL;
	}

	/* Then sign the result of the previous push, where the sig was zero'ed out */
	ret = smb_krb5_make_pac_checksum(mem_ctx,
					 &tmp_blob,
					 context,
					 service_keyblock,
					 &srv_checksum->type,
					 &srv_checksum->signature);

	/* Then sign Server checksum */
	ret = smb_krb5_make_pac_checksum(mem_ctx,
					 &srv_checksum->signature,
					 context,
					 krbtgt_keyblock,
					 &kdc_checksum->type,
					 &kdc_checksum->signature);
	if (ret) {
		DEBUG(2, ("making krbtgt PAC checksum failed: %s\n",
			  smb_get_krb5_error_message(context, ret, mem_ctx)));
		talloc_free(pac_data);
		return ret;
	}

	/* And push it out again, this time to the world.  This relies on determanistic pointer values */
	ndr_err = ndr_push_struct_blob(&tmp_blob, mem_ctx,
				       pac_data,
				       (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		nt_status = ndr_map_error2ntstatus(ndr_err);
		DEBUG(1, ("PAC (final) push failed: %s\n", nt_errstr(nt_status)));
		talloc_free(pac_data);
		return EINVAL;
	}

	*pac = tmp_blob;

	return ret;
}


 krb5_error_code kerberos_create_pac(TALLOC_CTX *mem_ctx,
				     struct auth_user_info_dc *user_info_dc,
				     krb5_context context,
				     const krb5_keyblock *krbtgt_keyblock,
				     const krb5_keyblock *service_keyblock,
				     krb5_principal client_principal,
				     time_t tgs_authtime,
				     DATA_BLOB *pac)
{
	NTSTATUS nt_status;
	krb5_error_code ret;
	struct PAC_DATA *pac_data = talloc(mem_ctx, struct PAC_DATA);
	struct netr_SamInfo3 *sam3;
	union PAC_INFO *u_LOGON_INFO;
	struct PAC_LOGON_INFO *LOGON_INFO;
	union PAC_INFO *u_LOGON_NAME;
	struct PAC_LOGON_NAME *LOGON_NAME;
	union PAC_INFO *u_KDC_CHECKSUM;
	union PAC_INFO *u_SRV_CHECKSUM;

	char *name;

	enum {
		PAC_BUF_LOGON_INFO = 0,
		PAC_BUF_LOGON_NAME = 1,
		PAC_BUF_SRV_CHECKSUM = 2,
		PAC_BUF_KDC_CHECKSUM = 3,
		PAC_BUF_NUM_BUFFERS = 4
	};

	if (!pac_data) {
		return ENOMEM;
	}

	pac_data->num_buffers = PAC_BUF_NUM_BUFFERS;
	pac_data->version = 0;

	pac_data->buffers = talloc_array(pac_data,
					 struct PAC_BUFFER,
					 pac_data->num_buffers);
	if (!pac_data->buffers) {
		talloc_free(pac_data);
		return ENOMEM;
	}

	/* LOGON_INFO */
	u_LOGON_INFO = talloc_zero(pac_data->buffers, union PAC_INFO);
	if (!u_LOGON_INFO) {
		talloc_free(pac_data);
		return ENOMEM;
	}
	pac_data->buffers[PAC_BUF_LOGON_INFO].type = PAC_TYPE_LOGON_INFO;
	pac_data->buffers[PAC_BUF_LOGON_INFO].info = u_LOGON_INFO;

	/* LOGON_NAME */
	u_LOGON_NAME = talloc_zero(pac_data->buffers, union PAC_INFO);
	if (!u_LOGON_NAME) {
		talloc_free(pac_data);
		return ENOMEM;
	}
	pac_data->buffers[PAC_BUF_LOGON_NAME].type = PAC_TYPE_LOGON_NAME;
	pac_data->buffers[PAC_BUF_LOGON_NAME].info = u_LOGON_NAME;
	LOGON_NAME = &u_LOGON_NAME->logon_name;

	/* SRV_CHECKSUM */
	u_SRV_CHECKSUM = talloc_zero(pac_data->buffers, union PAC_INFO);
	if (!u_SRV_CHECKSUM) {
		talloc_free(pac_data);
		return ENOMEM;
	}
	pac_data->buffers[PAC_BUF_SRV_CHECKSUM].type = PAC_TYPE_SRV_CHECKSUM;
	pac_data->buffers[PAC_BUF_SRV_CHECKSUM].info = u_SRV_CHECKSUM;

	/* KDC_CHECKSUM */
	u_KDC_CHECKSUM = talloc_zero(pac_data->buffers, union PAC_INFO);
	if (!u_KDC_CHECKSUM) {
		talloc_free(pac_data);
		return ENOMEM;
	}
	pac_data->buffers[PAC_BUF_KDC_CHECKSUM].type = PAC_TYPE_KDC_CHECKSUM;
	pac_data->buffers[PAC_BUF_KDC_CHECKSUM].info = u_KDC_CHECKSUM;

	/* now the real work begins... */

	LOGON_INFO = talloc_zero(u_LOGON_INFO, struct PAC_LOGON_INFO);
	if (!LOGON_INFO) {
		talloc_free(pac_data);
		return ENOMEM;
	}
	nt_status = auth_convert_user_info_dc_saminfo3(LOGON_INFO, user_info_dc, &sam3);
	if (!NT_STATUS_IS_OK(nt_status)) {
		DEBUG(1, ("Getting Samba info failed: %s\n", nt_errstr(nt_status)));
		talloc_free(pac_data);
		return EINVAL;
	}

	u_LOGON_INFO->logon_info.info		= LOGON_INFO;
	LOGON_INFO->info3 = *sam3;

	ret = krb5_unparse_name_flags(context, client_principal,
				      KRB5_PRINCIPAL_UNPARSE_NO_REALM, &name);
	if (ret) {
		return ret;
	}
	LOGON_NAME->account_name	= talloc_strdup(LOGON_NAME, name);
	free(name);
	/*
	  this logon_time field is absolutely critical. This is what
	  caused all our PAC troubles :-)
	*/
	unix_to_nt_time(&LOGON_NAME->logon_time, tgs_authtime);

	ret = kerberos_encode_pac(mem_ctx,
				  pac_data,
				  context,
				  krbtgt_keyblock,
				  service_keyblock,
				  pac);
	talloc_free(pac_data);
	return ret;
}

krb5_error_code kerberos_pac_to_user_info_dc(TALLOC_CTX *mem_ctx,
					     krb5_pac pac,
					     krb5_context context,
					     struct auth_user_info_dc **user_info_dc,
					     struct PAC_SIGNATURE_DATA *pac_srv_sig,
					     struct PAC_SIGNATURE_DATA *pac_kdc_sig)
{
	NTSTATUS nt_status;
	enum ndr_err_code ndr_err;
	krb5_error_code ret;

	DATA_BLOB pac_logon_info_in, pac_srv_checksum_in, pac_kdc_checksum_in;
	krb5_data k5pac_logon_info_in, k5pac_srv_checksum_in, k5pac_kdc_checksum_in;

	union PAC_INFO info;
	struct auth_user_info_dc *user_info_dc_out;

	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);

	if (!tmp_ctx) {
		return ENOMEM;
	}

	ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_LOGON_INFO, &k5pac_logon_info_in);
	if (ret != 0) {
		talloc_free(tmp_ctx);
		return EINVAL;
	}

	pac_logon_info_in = data_blob_const(k5pac_logon_info_in.data, k5pac_logon_info_in.length);

	ndr_err = ndr_pull_union_blob(&pac_logon_info_in, tmp_ctx, &info,
				      PAC_TYPE_LOGON_INFO,
				      (ndr_pull_flags_fn_t)ndr_pull_PAC_INFO);
	kerberos_free_data_contents(context, &k5pac_logon_info_in);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err) || !info.logon_info.info) {
		nt_status = ndr_map_error2ntstatus(ndr_err);
		DEBUG(0,("can't parse the PAC LOGON_INFO: %s\n", nt_errstr(nt_status)));
		talloc_free(tmp_ctx);
		return EINVAL;
	}

	/* Pull this right into the normal auth sysstem structures */
	nt_status = make_user_info_dc_pac(mem_ctx,
					 info.logon_info.info,
					 &user_info_dc_out);
	if (!NT_STATUS_IS_OK(nt_status)) {
		talloc_free(tmp_ctx);
		return EINVAL;
	}

	if (pac_srv_sig) {
		ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_SRV_CHECKSUM, &k5pac_srv_checksum_in);
		if (ret != 0) {
			talloc_free(tmp_ctx);
			return ret;
		}

		pac_srv_checksum_in = data_blob_const(k5pac_srv_checksum_in.data, k5pac_srv_checksum_in.length);

		ndr_err = ndr_pull_struct_blob(&pac_srv_checksum_in, pac_srv_sig,
					       pac_srv_sig,
					       (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
		kerberos_free_data_contents(context, &k5pac_srv_checksum_in);
		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
			nt_status = ndr_map_error2ntstatus(ndr_err);
			DEBUG(0,("can't parse the KDC signature: %s\n",
				 nt_errstr(nt_status)));
			return EINVAL;
		}
	}

	if (pac_kdc_sig) {
		ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_KDC_CHECKSUM, &k5pac_kdc_checksum_in);
		if (ret != 0) {
			talloc_free(tmp_ctx);
			return ret;
		}

		pac_kdc_checksum_in = data_blob_const(k5pac_kdc_checksum_in.data, k5pac_kdc_checksum_in.length);

		ndr_err = ndr_pull_struct_blob(&pac_kdc_checksum_in, pac_kdc_sig,
					       pac_kdc_sig,
					       (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
		kerberos_free_data_contents(context, &k5pac_kdc_checksum_in);
		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
			nt_status = ndr_map_error2ntstatus(ndr_err);
			DEBUG(0,("can't parse the KDC signature: %s\n",
				 nt_errstr(nt_status)));
			return EINVAL;
		}
	}
	*user_info_dc = user_info_dc_out;

	return 0;
}


NTSTATUS kerberos_pac_blob_to_user_info_dc(TALLOC_CTX *mem_ctx,
					   DATA_BLOB pac_blob,
					   krb5_context context,
					   struct auth_user_info_dc **user_info_dc,
					   struct PAC_SIGNATURE_DATA *pac_srv_sig,
					   struct PAC_SIGNATURE_DATA *pac_kdc_sig)
{
	krb5_error_code ret;
	krb5_pac pac;
	ret = krb5_pac_parse(context,
			     pac_blob.data, pac_blob.length,
			     &pac);
	if (ret) {
		return map_nt_error_from_unix_common(ret);
	}


	ret = kerberos_pac_to_user_info_dc(mem_ctx, pac, context, user_info_dc, pac_srv_sig, pac_kdc_sig);
	krb5_pac_free(context, pac);
	if (ret) {
		return map_nt_error_from_unix_common(ret);
	}
	return NT_STATUS_OK;
}