summaryrefslogtreecommitdiff
path: root/libcli/auth/schannel_state_tdb.c
blob: c1557e8a288f0937cb0541e7b67f4a7c91d16280 (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
/*
   Unix SMB/CIFS implementation.

   module to store/fetch session keys for the schannel server

   Copyright (C) Andrew Tridgell 2004
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2006-2009
   Copyright (C) Guenther Deschner 2009

   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/filesys.h"
#include <tdb.h>
#include "../lib/util/util_tdb.h"
#include "../libcli/auth/libcli_auth.h"
#include "../libcli/auth/schannel_state.h"
#include "../librpc/gen_ndr/ndr_schannel.h"
#if _SAMBA_BUILD_ == 4
#include "tdb_wrap.h"
#endif

#define SECRETS_SCHANNEL_STATE "SECRETS/SCHANNEL"

/******************************************************************************
 Open or create the schannel session store tdb.
*******************************************************************************/

#define SCHANNEL_STORE_VERSION_1 1
#define SCHANNEL_STORE_VERSION_2 2 /* should not be used */
#define SCHANNEL_STORE_VERSION_CURRENT SCHANNEL_STORE_VERSION_1

static struct tdb_wrap *open_schannel_session_store(TALLOC_CTX *mem_ctx,
						    const char *private_dir)
{
	TDB_DATA vers;
	uint32_t ver;
	struct tdb_wrap *tdb_sc = NULL;
	char *fname = talloc_asprintf(mem_ctx, "%s/schannel_store.tdb", private_dir);

	if (!fname) {
		return NULL;
	}

	tdb_sc = tdb_wrap_open(mem_ctx, fname, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600);

	if (!tdb_sc) {
		DEBUG(0,("open_schannel_session_store: Failed to open %s - %s\n",
			 fname, strerror(errno)));
		TALLOC_FREE(fname);
		return NULL;
	}

 again:
	vers = tdb_fetch_bystring(tdb_sc->tdb, "SCHANNEL_STORE_VERSION");
	if (vers.dptr == NULL) {
		/* First opener, no version. */
		SIVAL(&ver,0,SCHANNEL_STORE_VERSION_CURRENT);
		vers.dptr = (uint8_t *)&ver;
		vers.dsize = 4;
		tdb_store_bystring(tdb_sc->tdb, "SCHANNEL_STORE_VERSION", vers, TDB_REPLACE);
		vers.dptr = NULL;
	} else if (vers.dsize == 4) {
		ver = IVAL(vers.dptr,0);
		if (ver == SCHANNEL_STORE_VERSION_2) {
			DEBUG(0,("open_schannel_session_store: wrong version number %d in %s\n",
				(int)ver, fname ));
			tdb_wipe_all(tdb_sc->tdb);
			goto again;
		}
		if (ver != SCHANNEL_STORE_VERSION_CURRENT) {
			DEBUG(0,("open_schannel_session_store: wrong version number %d in %s\n",
				(int)ver, fname ));
			TALLOC_FREE(tdb_sc);
		}
	} else {
		TALLOC_FREE(tdb_sc);
		DEBUG(0,("open_schannel_session_store: wrong version number size %d in %s\n",
			(int)vers.dsize, fname ));
	}

	SAFE_FREE(vers.dptr);
	TALLOC_FREE(fname);

	return tdb_sc;
}

/********************************************************************
 ********************************************************************/

static
NTSTATUS schannel_store_session_key_tdb(struct tdb_wrap *tdb_sc,
					TALLOC_CTX *mem_ctx,
					struct smb_iconv_convenience *ic,
					struct netlogon_creds_CredentialState *creds)
{
	enum ndr_err_code ndr_err;
	DATA_BLOB blob;
	TDB_DATA value;
	int ret;
	char *keystr;
	char *name_upper;

	name_upper = strupper_talloc(mem_ctx, creds->computer_name);
	if (!name_upper) {
		return NT_STATUS_NO_MEMORY;
	}

	keystr = talloc_asprintf(mem_ctx, "%s/%s",
				 SECRETS_SCHANNEL_STATE, name_upper);
	TALLOC_FREE(name_upper);
	if (!keystr) {
		return NT_STATUS_NO_MEMORY;
	}

	ndr_err = ndr_push_struct_blob(&blob, mem_ctx, ic, creds,
			(ndr_push_flags_fn_t)ndr_push_netlogon_creds_CredentialState);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		talloc_free(keystr);
		return ndr_map_error2ntstatus(ndr_err);
	}

	value.dptr = blob.data;
	value.dsize = blob.length;

	ret = tdb_store_bystring(tdb_sc->tdb, keystr, value, TDB_REPLACE);
	if (ret != TDB_SUCCESS) {
		DEBUG(0,("Unable to add %s to session key db - %s\n",
			 keystr, tdb_errorstr(tdb_sc->tdb)));
		talloc_free(keystr);
		return NT_STATUS_INTERNAL_DB_CORRUPTION;
	}

	DEBUG(3,("schannel_store_session_key_tdb: stored schannel info with key %s\n",
		keystr));

	if (DEBUGLEVEL >= 10) {
		NDR_PRINT_DEBUG(netlogon_creds_CredentialState, creds);
	}

	talloc_free(keystr);

	return NT_STATUS_OK;
}

/********************************************************************
 ********************************************************************/

static
NTSTATUS schannel_fetch_session_key_tdb(struct tdb_wrap *tdb_sc,
					TALLOC_CTX *mem_ctx,
					struct smb_iconv_convenience *ic,
					const char *computer_name,
					struct netlogon_creds_CredentialState **pcreds)
{
	NTSTATUS status;
	TDB_DATA value;
	enum ndr_err_code ndr_err;
	DATA_BLOB blob;
	struct netlogon_creds_CredentialState *creds = NULL;
	char *keystr = NULL;
	char *name_upper;

	*pcreds = NULL;

	name_upper = strupper_talloc(mem_ctx, computer_name);
	if (!name_upper) {
		return NT_STATUS_NO_MEMORY;
	}

	keystr = talloc_asprintf(mem_ctx, "%s/%s",
				 SECRETS_SCHANNEL_STATE, name_upper);
	TALLOC_FREE(name_upper);
	if (!keystr) {
		status = NT_STATUS_NO_MEMORY;
		goto done;
	}

	value = tdb_fetch_bystring(tdb_sc->tdb, keystr);
	if (!value.dptr) {
		DEBUG(0,("schannel_fetch_session_key_tdb: Failed to find entry with key %s\n",
			keystr ));
		status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
		goto done;
	}

	creds = talloc_zero(mem_ctx, struct netlogon_creds_CredentialState);
	if (!creds) {
		status = NT_STATUS_NO_MEMORY;
		goto done;
	}

	blob = data_blob_const(value.dptr, value.dsize);

	ndr_err = ndr_pull_struct_blob(&blob, creds, ic, creds,
			(ndr_pull_flags_fn_t)ndr_pull_netlogon_creds_CredentialState);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		status = ndr_map_error2ntstatus(ndr_err);
		goto done;
	}

	if (DEBUGLEVEL >= 10) {
		NDR_PRINT_DEBUG(netlogon_creds_CredentialState, creds);
	}

	DEBUG(3,("schannel_fetch_session_key_tdb: restored schannel info key %s\n",
		keystr));

	status = NT_STATUS_OK;

 done:

	talloc_free(keystr);
	SAFE_FREE(value.dptr);

	if (!NT_STATUS_IS_OK(status)) {
		talloc_free(creds);
		return status;
	}

	*pcreds = creds;

	return NT_STATUS_OK;
}

/******************************************************************************
 Wrapper around schannel_fetch_session_key_tdb()
 Note we must be root here.
*******************************************************************************/

NTSTATUS schannel_get_creds_state(TALLOC_CTX *mem_ctx,
				  struct smb_iconv_convenience *ic,
				  const char *db_priv_dir,
				  const char *computer_name,
				  struct netlogon_creds_CredentialState **_creds)
{
	TALLOC_CTX *tmpctx;
	struct tdb_wrap *tdb_sc;
	struct netlogon_creds_CredentialState *creds;
	NTSTATUS status;

	tmpctx = talloc_named(mem_ctx, 0, "schannel_get_creds_state");
	if (!tmpctx) {
		return NT_STATUS_NO_MEMORY;
	}

	tdb_sc = open_schannel_session_store(tmpctx, db_priv_dir);
	if (!tdb_sc) {
		return NT_STATUS_ACCESS_DENIED;
	}

	status = schannel_fetch_session_key_tdb(tdb_sc, tmpctx, ic,
						computer_name, &creds);
	if (NT_STATUS_IS_OK(status)) {
		*_creds = talloc_steal(mem_ctx, creds);
		if (!*_creds) {
			status = NT_STATUS_NO_MEMORY;
		}
	}

	talloc_free(tmpctx);
	return status;
}

/******************************************************************************
 Wrapper around schannel_store_session_key_tdb()
 Note we must be root here.
*******************************************************************************/

NTSTATUS schannel_save_creds_state(TALLOC_CTX *mem_ctx,
				   struct smb_iconv_convenience *ic,
				   const char *db_priv_dir,
				   struct netlogon_creds_CredentialState *creds)
{
	TALLOC_CTX *tmpctx;
	struct tdb_wrap *tdb_sc;
	NTSTATUS status;

	tmpctx = talloc_named(mem_ctx, 0, "schannel_save_creds_state");
	if (!tmpctx) {
		return NT_STATUS_NO_MEMORY;
	}

	tdb_sc = open_schannel_session_store(tmpctx, db_priv_dir);
	if (!tdb_sc) {
		return NT_STATUS_ACCESS_DENIED;
	}

	status = schannel_store_session_key_tdb(tdb_sc, tmpctx, ic, creds);

	talloc_free(tmpctx);
	return status;
}

/********************************************************************
 Validate an incoming authenticator against the credentials for the
 remote machine stored in the schannel database.

 The credentials are (re)read and from the schannel database, and
 written back after the caclulations are performed.

 If the creds_out parameter is not NULL returns the credentials.
 ********************************************************************/

NTSTATUS schannel_check_creds_state(TALLOC_CTX *mem_ctx,
				    struct smb_iconv_convenience *ic,
				    const char *db_priv_dir,
				    const char *computer_name,
				    struct netr_Authenticator *received_authenticator,
				    struct netr_Authenticator *return_authenticator,
				    struct netlogon_creds_CredentialState **creds_out)
{
	TALLOC_CTX *tmpctx;
	struct tdb_wrap *tdb_sc;
	struct netlogon_creds_CredentialState *creds;
	NTSTATUS status;
	int ret;

	tmpctx = talloc_named(mem_ctx, 0, "schannel_check_creds_state");
	if (!tmpctx) {
		return NT_STATUS_NO_MEMORY;
	}

	tdb_sc = open_schannel_session_store(tmpctx, db_priv_dir);
	if (!tdb_sc) {
		status = NT_STATUS_ACCESS_DENIED;
		goto done;
	}

	ret = tdb_transaction_start(tdb_sc->tdb);
	if (ret != 0) {
		status = NT_STATUS_INTERNAL_DB_CORRUPTION;
		goto done;
	}

	/* Because this is a shared structure (even across
	 * disconnects) we must update the database every time we
	 * update the structure */

	status = schannel_fetch_session_key_tdb(tdb_sc, tmpctx, ic,
						computer_name, &creds);
	if (!NT_STATUS_IS_OK(status)) {
		tdb_transaction_cancel(tdb_sc->tdb);
		goto done;
	}

	status = netlogon_creds_server_step_check(creds,
						  received_authenticator,
						  return_authenticator);
	if (!NT_STATUS_IS_OK(status)) {
		tdb_transaction_cancel(tdb_sc->tdb);
		goto done;
	}

	status = schannel_store_session_key_tdb(tdb_sc, tmpctx, ic, creds);
	if (!NT_STATUS_IS_OK(status)) {
		tdb_transaction_cancel(tdb_sc->tdb);
		goto done;
	}

	tdb_transaction_commit(tdb_sc->tdb);

	if (creds_out) {
		*creds_out = talloc_steal(mem_ctx, creds);
		if (!*creds_out) {
			status = NT_STATUS_NO_MEMORY;
			goto done;
		}
	}

	status = NT_STATUS_OK;

done:
	talloc_free(tmpctx);
	return status;
}