summaryrefslogtreecommitdiff
path: root/source3/libnet/libnet_keytab.c
blob: 23eedafe2b7286ed1f62abfa87638a594c565b0e (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
397
398
399
400
401
402
403
404
/*
   Unix SMB/CIFS implementation.
   dump the remote SAM using rpc samsync operations

   Copyright (C) Guenther Deschner 2008.

   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 "libnet/libnet.h"

#ifdef HAVE_KRB5

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

static int keytab_close(struct libnet_keytab_context *ctx)
{
	if (!ctx) {
		return 0;
	}

	if (ctx->keytab && ctx->context) {
		krb5_kt_close(ctx->context, ctx->keytab);
	}

	if (ctx->context) {
		krb5_free_context(ctx->context);
	}

	if (ctx->ads) {
		ads_destroy(&ctx->ads);
	}

	TALLOC_FREE(ctx);

	return 0;
}

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

krb5_error_code libnet_keytab_init(TALLOC_CTX *mem_ctx,
				   const char *keytab_name,
				   struct libnet_keytab_context **ctx)
{
	krb5_error_code ret = 0;
	krb5_context context = NULL;
	krb5_keytab keytab = NULL;
	const char *keytab_string = NULL;

	struct libnet_keytab_context *r;

	r = TALLOC_ZERO_P(mem_ctx, struct libnet_keytab_context);
	if (!r) {
		return ENOMEM;
	}

	talloc_set_destructor(r, keytab_close);

	initialize_krb5_error_table();
	ret = krb5_init_context(&context);
	if (ret) {
		DEBUG(1,("keytab_init: could not krb5_init_context: %s\n",
			error_message(ret)));
		return ret;
	}

	ret = smb_krb5_open_keytab(context, keytab_name, true, &keytab);
	if (ret) {
		DEBUG(1,("keytab_init: smb_krb5_open_keytab failed (%s)\n",
			error_message(ret)));
		krb5_free_context(context);
		return ret;
	}

	ret = smb_krb5_keytab_name(mem_ctx, context, keytab, &keytab_string);
	if (ret) {
		krb5_kt_close(context, keytab);
		krb5_free_context(context);
		return ret;
	}

	r->context = context;
	r->keytab = keytab;
	r->keytab_name = keytab_string;
	r->clean_old_entries = false;

	*ctx = r;

	return 0;
}

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

/**
 * Remove all entries that have the given principal, kvno and enctype.
 */
static krb5_error_code libnet_keytab_remove_entries(krb5_context context,
						    krb5_keytab keytab,
						    const char *principal,
						    int kvno,
						    const krb5_enctype enctype,
						    bool ignore_kvno)
{
	krb5_error_code ret;
	krb5_kt_cursor cursor;
	krb5_keytab_entry kt_entry;

	ZERO_STRUCT(kt_entry);
	ZERO_STRUCT(cursor);

	ret = krb5_kt_start_seq_get(context, keytab, &cursor);
	if (ret) {
		return 0;
	}

	while (krb5_kt_next_entry(context, keytab, &kt_entry, &cursor) == 0)
	{
		char *princ_s = NULL;

		if (kt_entry.vno != kvno && !ignore_kvno) {
			goto cont;
		}

		if (kt_entry.key.enctype != enctype) {
			goto cont;
		}

		ret = smb_krb5_unparse_name(context, kt_entry.principal,
					    &princ_s);
		if (ret) {
			DEBUG(5, ("smb_krb5_unparse_name failed (%s)\n",
				  error_message(ret)));
			goto cont;
		}

		if (strcmp(principal, princ_s) != 0) {
			goto cont;
		}

		/* match found - remove */

		DEBUG(10, ("found entry for principal %s, kvno %d, "
			   "enctype %d - trying to remove it\n",
			   princ_s, kt_entry.vno, kt_entry.key.enctype));

		ret = krb5_kt_end_seq_get(context, keytab, &cursor);
		ZERO_STRUCT(cursor);
		if (ret) {
			DEBUG(5, ("krb5_kt_end_seq_get failed (%s)\n",
				  error_message(ret)));
			goto cont;
		}

		ret = krb5_kt_remove_entry(context, keytab,
					   &kt_entry);
		if (ret) {
			DEBUG(5, ("krb5_kt_remove_entry failed (%s)\n",
				  error_message(ret)));
			goto cont;
		}
		DEBUG(10, ("removed entry for principal %s, kvno %d, "
			   "enctype %d\n", princ_s, kt_entry.vno,
			   kt_entry.key.enctype));

		ret = krb5_kt_start_seq_get(context, keytab, &cursor);
		if (ret) {
			DEBUG(5, ("krb5_kt_start_seq_get failed (%s)\n",
				  error_message(ret)));
			goto cont;
		}

cont:
		smb_krb5_kt_free_entry(context, &kt_entry);
		SAFE_FREE(princ_s);
	}

	ret = krb5_kt_end_seq_get(context, keytab, &cursor);
	if (ret) {
		DEBUG(5, ("krb5_kt_end_seq_get failed (%s)\n",
			  error_message(ret)));
	}

	return ret;
}

static krb5_error_code libnet_keytab_add_entry(krb5_context context,
					       krb5_keytab keytab,
					       krb5_kvno kvno,
					       const char *princ_s,
					       krb5_enctype enctype,
					       krb5_data password)
{
	krb5_keyblock *keyp;
	krb5_keytab_entry kt_entry;
	krb5_error_code ret;

	/* remove duplicates first ... */
	ret = libnet_keytab_remove_entries(context, keytab, princ_s, kvno,
					   enctype, false);
	if (ret) {
		DEBUG(1, ("libnet_keytab_remove_entries failed: %s\n",
			  error_message(ret)));
	}

	ZERO_STRUCT(kt_entry);

	kt_entry.vno = kvno;

	ret = smb_krb5_parse_name(context, princ_s, &kt_entry.principal);
	if (ret) {
		DEBUG(1, ("smb_krb5_parse_name(%s) failed (%s)\n",
			  princ_s, error_message(ret)));
		return ret;
	}

#if !defined(HAVE_KRB5_KEYTAB_ENTRY_KEY) && !defined(HAVE_KRB5_KEYTAB_ENTRY_KEYBLOCK)
#error krb5_keytab_entry has no key or keyblock member
#endif
#ifdef HAVE_KRB5_KEYTAB_ENTRY_KEY               /* MIT */
	keyp = &kt_entry.key;
#endif
#ifdef HAVE_KRB5_KEYTAB_ENTRY_KEYBLOCK          /* Heimdal */
	keyp = &kt_entry.keyblock;
#endif

	if (create_kerberos_key_from_string(context, kt_entry.principal,
					    &password, keyp, enctype, true))
	{
		ret = KRB5KRB_ERR_GENERIC;
		goto done;
	}

	ret = krb5_kt_add_entry(context, keytab, &kt_entry);
	if (ret) {
		DEBUG(1, ("adding entry to keytab failed (%s)\n",
			  error_message(ret)));
	}

done:
	krb5_free_keyblock_contents(context, keyp);
	krb5_free_principal(context, kt_entry.principal);
	ZERO_STRUCT(kt_entry);
	smb_krb5_kt_free_entry(context, &kt_entry);

	return ret;
}

krb5_error_code libnet_keytab_add(struct libnet_keytab_context *ctx)
{
	krb5_error_code ret = 0;
	uint32_t i;


	if (ctx->clean_old_entries) {
		DEBUG(0, ("cleaning old entries...\n"));
		for (i=0; i < ctx->count; i++) {
			struct libnet_keytab_entry *entry = &ctx->entries[i];

			ret = libnet_keytab_remove_entries(ctx->context,
							   ctx->keytab,
							   entry->principal,
							   0,
							   entry->enctype,
							   true);
			if (ret) {
				DEBUG(1,("libnet_keytab_add: Failed to remove "
					 "old entries for %s (enctype %u): %s\n",
					 entry->principal, entry->enctype,
					 error_message(ret)));
				return ret;
			}
		}
	}

	for (i=0; i<ctx->count; i++) {

		struct libnet_keytab_entry *entry = &ctx->entries[i];
		krb5_data password;

		password.data = (char *)entry->password.data;
		password.length = entry->password.length;

		ret = libnet_keytab_add_entry(ctx->context,
					      ctx->keytab,
					      entry->kvno,
					      entry->principal,
					      entry->enctype,
					      password);
		if (ret) {
			DEBUG(1,("libnet_keytab_add: "
				"Failed to add entry to keytab file\n"));
			return ret;
		}
	}

	return ret;
}

struct libnet_keytab_entry *libnet_keytab_search(struct libnet_keytab_context *ctx,
						 const char *principal,
						 int kvno,
						 const krb5_enctype enctype,
						 TALLOC_CTX *mem_ctx)
{
	krb5_error_code ret = 0;
	krb5_kt_cursor cursor;
	krb5_keytab_entry kt_entry;
	struct libnet_keytab_entry *entry = NULL;

	ZERO_STRUCT(kt_entry);
	ZERO_STRUCT(cursor);

	ret = krb5_kt_start_seq_get(ctx->context, ctx->keytab, &cursor);
	if (ret) {
		DEBUG(10, ("krb5_kt_start_seq_get failed: %s",
			  error_message(ret)));
		return NULL;
	}

	while (krb5_kt_next_entry(ctx->context, ctx->keytab, &kt_entry, &cursor) == 0)
	{
		char *princ_s = NULL;

		if (kt_entry.vno != kvno) {
			goto cont;
		}

		if (kt_entry.key.enctype != enctype) {
			goto cont;
		}

		ret = smb_krb5_unparse_name(ctx->context, kt_entry.principal,
					    &princ_s);
		if (ret) {
			goto cont;
		}

		if (strcmp(principal, princ_s) != 0) {
			goto cont;
		}

		entry = talloc_zero(mem_ctx, struct libnet_keytab_entry);
		if (!entry) {
			DEBUG(3, ("talloc failed\n"));
			goto fail;
		}

		entry->name = talloc_strdup(entry, princ_s);
		if (!entry->name) {
			DEBUG(3, ("talloc_strdup_failed\n"));
			goto fail;
		}

		entry->principal = talloc_strdup(entry, princ_s);
		if (!entry->principal) {
			DEBUG(3, ("talloc_strdup_failed\n"));
			goto fail;
		}

		entry->password = data_blob_talloc(entry, kt_entry.key.contents,
						   kt_entry.key.length);
		if (!entry->password.data) {
			DEBUG(3, ("data_blob_talloc failed\n"));
			goto fail;
		}

		DEBUG(10, ("found entry\n"));

		smb_krb5_kt_free_entry(ctx->context, &kt_entry);
		SAFE_FREE(princ_s);
		break;

fail:
		smb_krb5_kt_free_entry(ctx->context, &kt_entry);
		SAFE_FREE(princ_s);
		TALLOC_FREE(entry);
		break;

cont:
		smb_krb5_kt_free_entry(ctx->context, &kt_entry);
		SAFE_FREE(princ_s);
		continue;
	}

	krb5_kt_end_seq_get(ctx->context, ctx->keytab, &cursor);
	return entry;
}

#endif /* HAVE_KRB5 */