summaryrefslogtreecommitdiff
path: root/libnm-util/crypto_gnutls.c
blob: 8604c5c3bca37eb8a9ff9ca614cc9b18852f5e88 (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
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
/* NetworkManager Wireless Applet -- Display wireless access points and allow user control
 *
 * Dan Williams <dcbw@redhat.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301 USA.
 *
 * Copyright 2007 - 2015 Red Hat, Inc.
 */

#include "nm-default.h"

#include <gnutls/gnutls.h>
#include <gnutls/crypto.h>
#include <gnutls/x509.h>
#include <gnutls/pkcs12.h>

#include "crypto.h"

#define SALT_LEN 8

static gboolean initialized = FALSE;

gboolean
crypto_init (GError **error)
{
	if (initialized)
		return TRUE;

	if (gnutls_global_init() != 0) {
		gnutls_global_deinit();
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_INIT_FAILED,
		             "%s",
		             _("Failed to initialize the crypto engine."));
		return FALSE;
	}

	initialized = TRUE;
	return TRUE;
}

gboolean
crypto_md5_hash (const char *salt,
                 const gsize salt_len,
                 const char *password,
                 gsize password_len,
                 char *buffer,
                 gsize buflen,
                 GError **error)
{
	gnutls_hash_hd_t ctx;
	int err;
	int nkey = buflen;
	const gsize digest_len = 16;
	int count = 0;
	char digest[MD5_HASH_LEN];
	char *p = buffer;

	if (salt)
		g_return_val_if_fail (salt_len >= SALT_LEN, FALSE);

	g_return_val_if_fail (password != NULL, FALSE);
	g_return_val_if_fail (password_len > 0, FALSE);
	g_return_val_if_fail (buffer != NULL, FALSE);
	g_return_val_if_fail (buflen > 0, FALSE);

	if (gnutls_hash_get_len (GNUTLS_DIG_MD5) > MD5_HASH_LEN) {
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_MD5_INIT_FAILED,
		             _("Hash length too long (%d > %d)."),
		             gnutls_hash_get_len (GNUTLS_DIG_MD5), MD5_HASH_LEN);
		return FALSE;
	}

	while (nkey > 0) {
		int i = 0;

		err = gnutls_hash_init (&ctx, GNUTLS_DIG_MD5);
		if (err < 0)
			goto error;

		if (count++)
			gnutls_hash (ctx, digest, digest_len);
		gnutls_hash (ctx, password, password_len);
		if (salt)
			gnutls_hash (ctx, salt, SALT_LEN); /* Only use 8 bytes of salt */
		gnutls_hash_deinit (ctx, digest);

		while (nkey && (i < digest_len)) {
			*(p++) = digest[i++];
			nkey--;
		}
	}

	memset (digest, 0, sizeof (digest));
	return TRUE;
error:
	memset (digest, 0, sizeof (digest));
	g_set_error (error, NM_CRYPTO_ERROR,
	             NM_CRYPTO_ERR_MD5_INIT_FAILED,
	             _("Failed to initialize the MD5 engine: %s (%s)"),
	             gnutls_strerror_name (err), gnutls_strerror (err));
	return FALSE;
}

char *
crypto_decrypt (const char *cipher,
                int key_type,
                GByteArray *data,
                const char *iv,
                const gsize iv_len,
                const char *key,
                const gsize key_len,
                gsize *out_len,
                GError **error)
{
	gnutls_cipher_hd_t ctx;
	gnutls_datum_t key_dt, iv_dt;
	int err;
	int cipher_mech, i;
	char *output = NULL;
	gboolean success = FALSE;
	gsize pad_len, real_iv_len;

	if (!strcmp (cipher, CIPHER_DES_EDE3_CBC)) {
		cipher_mech = GNUTLS_CIPHER_3DES_CBC;
		real_iv_len = SALT_LEN;
	} else if (!strcmp (cipher, CIPHER_DES_CBC)) {
		cipher_mech = GNUTLS_CIPHER_DES_CBC;
		real_iv_len = SALT_LEN;
	} else if (!strcmp (cipher, CIPHER_AES_CBC)) {
		cipher_mech = GNUTLS_CIPHER_AES_128_CBC;
		real_iv_len = 16;
	} else {
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_UNKNOWN_CIPHER,
		             _("Private key cipher '%s' was unknown."),
		             cipher);
		return NULL;
	}

	if (iv_len < real_iv_len) {
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_RAW_IV_INVALID,
		             _("Invalid IV length (must be at least %zd)."),
		             real_iv_len);
		return NULL;
	}

	output = g_malloc0 (data->len);

	key_dt.data = (unsigned char *) key;
	key_dt.size = key_len;
	iv_dt.data = (unsigned char *) iv;
	iv_dt.size = iv_len;

	err = gnutls_cipher_init (&ctx, cipher_mech, &key_dt, &iv_dt);
	if (err < 0) {
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_CIPHER_INIT_FAILED,
		             _("Failed to initialize the decryption cipher context: %s (%s)"),
		             gnutls_strerror_name (err), gnutls_strerror (err));
		goto out;
	}

	err = gnutls_cipher_decrypt2 (ctx, data->data, data->len, output, data->len);
	if (err < 0) {
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_CIPHER_DECRYPT_FAILED,
		             _("Failed to decrypt the private key: %s (%s)"),
		             gnutls_strerror_name (err), gnutls_strerror (err));
		goto out;
	}
	pad_len = output[data->len - 1];

	/* Check if the padding at the end of the decrypted data is valid */
	if (pad_len == 0 || pad_len > real_iv_len) {
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_CIPHER_DECRYPT_FAILED,
		             _("Failed to decrypt the private key: unexpected padding length."));
		goto out;
	}

	/* Validate tail padding; last byte is the padding size, and all pad bytes
	 * should contain the padding size.
	 */
	for (i = 1; i <= pad_len; ++i) {
		if (output[data->len - i] != pad_len) {
			g_set_error (error, NM_CRYPTO_ERROR,
			             NM_CRYPTO_ERR_CIPHER_DECRYPT_FAILED,
			             _("Failed to decrypt the private key."));
			goto out;
		}
	}

	*out_len = data->len - pad_len;
	success = TRUE;

out:
	if (!success) {
		if (output) {
			/* Don't expose key material */
			memset (output, 0, data->len);
			g_free (output);
			output = NULL;
		}
	}
	gnutls_cipher_deinit (ctx);
	return output;
}

char *
crypto_encrypt (const char *cipher,
                const GByteArray *data,
                const char *iv,
                const gsize iv_len,
                const char *key,
                gsize key_len,
                gsize *out_len,
                GError **error)
{
	gnutls_cipher_hd_t ctx;
	gnutls_datum_t key_dt, iv_dt;
	int err;
	int cipher_mech;
	char *output = NULL;
	gboolean success = FALSE;
	gsize padded_buf_len, pad_len, output_len;
	char *padded_buf = NULL;
	guint32 i;
	gsize salt_len;

	if (!strcmp (cipher, CIPHER_DES_EDE3_CBC)) {
		cipher_mech = GNUTLS_CIPHER_3DES_CBC;
		salt_len = SALT_LEN;
	} else if (!strcmp (cipher, CIPHER_AES_CBC)) {
		cipher_mech = GNUTLS_CIPHER_AES_128_CBC;
		salt_len = iv_len;
	} else {
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_UNKNOWN_CIPHER,
		             _("Private key cipher '%s' was unknown."),
		             cipher);
		return NULL;
	}

	/* If data->len % ivlen == 0, then we add another complete block
	 * onto the end so that the decrypter knows there's padding.
	 */
	pad_len = iv_len - (data->len % iv_len);
	output_len = padded_buf_len = data->len + pad_len;
	padded_buf = g_malloc0 (padded_buf_len);

	memcpy (padded_buf, data->data, data->len);
	for (i = 0; i < pad_len; i++)
		padded_buf[data->len + i] = (guint8) (pad_len & 0xFF);

	output = g_malloc0 (output_len);

	key_dt.data = (unsigned char *) key;
	key_dt.size = key_len;
	iv_dt.data = (unsigned char *) iv;
	iv_dt.size = iv_len;

	err = gnutls_cipher_init (&ctx, cipher_mech, &key_dt, &iv_dt);
	if (err < 0) {
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_CIPHER_INIT_FAILED,
		             _("Failed to initialize the encryption cipher context: %s (%s)"),
		             gnutls_strerror_name (err), gnutls_strerror (err));
		goto out;
	}

	err = gnutls_cipher_encrypt2 (ctx, padded_buf, padded_buf_len, output, output_len);
	if (err < 0) {
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_CIPHER_DECRYPT_FAILED,
		             _("Failed to encrypt the data: %s (%s)"),
		             gnutls_strerror_name (err), gnutls_strerror (err));
		goto out;
	}

	*out_len = output_len;
	success = TRUE;

out:
	if (padded_buf) {
		memset (padded_buf, 0, padded_buf_len);
		g_free (padded_buf);
		padded_buf = NULL;
	}

	if (!success) {
		if (output) {
			/* Don't expose key material */
			memset (output, 0, output_len);
			g_free (output);
			output = NULL;
		}
	}
	gnutls_cipher_deinit (ctx);
	return output;
}

NMCryptoFileFormat
crypto_verify_cert (const unsigned char *data,
                    gsize len,
                    GError **error)
{
	gnutls_x509_crt_t der;
	gnutls_datum_t dt;
	int err;

	err = gnutls_x509_crt_init (&der);
	if (err < 0) {
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_CERT_FORMAT_INVALID,
		             _("Error initializing certificate data: %s"),
		             gnutls_strerror (err));
		return NM_CRYPTO_FILE_FORMAT_UNKNOWN;
	}

	/* Try DER first */
	dt.data = (unsigned char *) data;
	dt.size = len;
	err = gnutls_x509_crt_import (der, &dt, GNUTLS_X509_FMT_DER);
	if (err == GNUTLS_E_SUCCESS) {
		gnutls_x509_crt_deinit (der);
		return NM_CRYPTO_FILE_FORMAT_X509;
	}

	/* And PEM next */
	err = gnutls_x509_crt_import (der, &dt, GNUTLS_X509_FMT_PEM);
	gnutls_x509_crt_deinit (der);
	if (err == GNUTLS_E_SUCCESS)
		return NM_CRYPTO_FILE_FORMAT_X509;

	g_set_error (error, NM_CRYPTO_ERROR,
	             NM_CRYPTO_ERR_CERT_FORMAT_INVALID,
	             _("Couldn't decode certificate: %s"),
	             gnutls_strerror (err));
	return NM_CRYPTO_FILE_FORMAT_UNKNOWN;
}

gboolean
crypto_verify_pkcs12 (const GByteArray *data,
                      const char *password,
                      GError **error)
{
	gnutls_pkcs12_t p12;
	gnutls_datum_t dt;
	gboolean success = FALSE;
	int err;

	g_return_val_if_fail (data != NULL, FALSE);

	dt.data = (unsigned char *) data->data;
	dt.size = data->len;

	err = gnutls_pkcs12_init (&p12);
	if (err < 0) {
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_DECODE_FAILED,
		             _("Couldn't initialize PKCS#12 decoder: %s"),
		             gnutls_strerror (err));
		return FALSE;
	}

	/* DER first */
	err = gnutls_pkcs12_import (p12, &dt, GNUTLS_X509_FMT_DER, 0);
	if (err < 0) {
		/* PEM next */
		err = gnutls_pkcs12_import (p12, &dt, GNUTLS_X509_FMT_PEM, 0);
		if (err < 0) {
			g_set_error (error, NM_CRYPTO_ERROR,
			             NM_CRYPTO_ERR_FILE_FORMAT_INVALID,
			             _("Couldn't decode PKCS#12 file: %s"),
			             gnutls_strerror (err));
			goto out;
		}
	}

	err = gnutls_pkcs12_verify_mac (p12, password);
	if (err == GNUTLS_E_SUCCESS)
		success = TRUE;
	else {
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_CIPHER_DECRYPT_FAILED,
		             _("Couldn't verify PKCS#12 file: %s"),
		             gnutls_strerror (err));
	}

out:
	gnutls_pkcs12_deinit (p12);
	return success;
}

gboolean
crypto_verify_pkcs8 (const GByteArray *data,
                     gboolean is_encrypted,
                     const char *password,
                     GError **error)
{
	gnutls_x509_privkey_t p8;
	gnutls_datum_t dt;
	int err;

	g_return_val_if_fail (data != NULL, FALSE);

	dt.data = (unsigned char *) data->data;
	dt.size = data->len;

	err = gnutls_x509_privkey_init (&p8);
	if (err < 0) {
		g_set_error (error, NM_CRYPTO_ERROR,
		             NM_CRYPTO_ERR_DECODE_FAILED,
		             _("Couldn't initialize PKCS#8 decoder: %s"),
		             gnutls_strerror (err));
		return FALSE;
	}

	err = gnutls_x509_privkey_import_pkcs8 (p8,
	                                        &dt,
	                                        GNUTLS_X509_FMT_DER,
	                                        is_encrypted ? password : NULL,
	                                        is_encrypted ? 0 : GNUTLS_PKCS_PLAIN);
	gnutls_x509_privkey_deinit (p8);

	if (err < 0) {
		if (err == GNUTLS_E_UNKNOWN_CIPHER_TYPE) {
			/* HACK: gnutls doesn't support all the cipher types that openssl
			 * can use with PKCS#8, so if we encounter one, we have to assume
			 * the given password works.  gnutls needs to unsuckify, apparently.
			 * Specifically, by default openssl uses pbeWithMD5AndDES-CBC
			 * which gnutls does not support.
			 */
		} else {
			g_set_error (error, NM_CRYPTO_ERROR,
			             NM_CRYPTO_ERR_FILE_FORMAT_INVALID,
			             _("Couldn't decode PKCS#8 file: %s"),
			             gnutls_strerror (err));
			return FALSE;
		}
	}

	return TRUE;
}

gboolean
crypto_randomize (void *buffer, gsize buffer_len, GError **error)
{
	gnutls_rnd (GNUTLS_RND_RANDOM, buffer, buffer_len);
	return TRUE;
}