blob: 635e8e16a5b7692b1d45b7629d404beeafdb8567 [file] [log] [blame]
Michael Halcrow237fead2006-10-04 02:16:22 -07001/**
2 * eCryptfs: Linux filesystem encryption layer
3 * In-kernel key management code. Includes functions to parse and
4 * write authentication token-related packets with the underlying
5 * file.
6 *
7 * Copyright (C) 2004-2006 International Business Machines Corp.
8 * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com>
9 * Michael C. Thompson <mcthomps@us.ibm.com>
Michael Halcrowdddfa462007-02-12 00:53:44 -080010 * Trevor S. Highland <trevor.highland@gmail.com>
Michael Halcrow237fead2006-10-04 02:16:22 -070011 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful, but
18 * WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 * General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
25 * 02111-1307, USA.
26 */
27
28#include <linux/string.h>
Michael Halcrow237fead2006-10-04 02:16:22 -070029#include <linux/pagemap.h>
30#include <linux/key.h>
31#include <linux/random.h>
32#include <linux/crypto.h>
33#include <linux/scatterlist.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090034#include <linux/slab.h>
Michael Halcrow237fead2006-10-04 02:16:22 -070035#include "ecryptfs_kernel.h"
36
37/**
38 * request_key returned an error instead of a valid key address;
39 * determine the type of error, make appropriate log entries, and
40 * return an error code.
41 */
Michael Halcrowcd9d67d2007-10-16 01:28:04 -070042static int process_request_key_err(long err_code)
Michael Halcrow237fead2006-10-04 02:16:22 -070043{
44 int rc = 0;
45
46 switch (err_code) {
Eric Sandeen982363c2008-07-23 21:30:04 -070047 case -ENOKEY:
Michael Halcrow237fead2006-10-04 02:16:22 -070048 ecryptfs_printk(KERN_WARNING, "No key\n");
49 rc = -ENOENT;
50 break;
Eric Sandeen982363c2008-07-23 21:30:04 -070051 case -EKEYEXPIRED:
Michael Halcrow237fead2006-10-04 02:16:22 -070052 ecryptfs_printk(KERN_WARNING, "Key expired\n");
53 rc = -ETIME;
54 break;
Eric Sandeen982363c2008-07-23 21:30:04 -070055 case -EKEYREVOKED:
Michael Halcrow237fead2006-10-04 02:16:22 -070056 ecryptfs_printk(KERN_WARNING, "Key revoked\n");
57 rc = -EINVAL;
58 break;
59 default:
60 ecryptfs_printk(KERN_WARNING, "Unknown error code: "
Joe Perches888d57b2010-11-10 15:46:16 -080061 "[0x%.16lx]\n", err_code);
Michael Halcrow237fead2006-10-04 02:16:22 -070062 rc = -EINVAL;
63 }
64 return rc;
65}
66
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +010067static int process_find_global_auth_tok_for_sig_err(int err_code)
68{
69 int rc = err_code;
70
71 switch (err_code) {
72 case -ENOENT:
73 ecryptfs_printk(KERN_WARNING, "Missing auth tok\n");
74 break;
75 case -EINVAL:
76 ecryptfs_printk(KERN_WARNING, "Invalid auth tok\n");
77 break;
78 default:
79 rc = process_request_key_err(err_code);
80 break;
81 }
82 return rc;
83}
84
Michael Halcrow237fead2006-10-04 02:16:22 -070085/**
Michael Halcrowf66e8832008-04-29 00:59:51 -070086 * ecryptfs_parse_packet_length
Michael Halcrow237fead2006-10-04 02:16:22 -070087 * @data: Pointer to memory containing length at offset
88 * @size: This function writes the decoded size to this memory
89 * address; zero on error
90 * @length_size: The number of bytes occupied by the encoded length
91 *
Michael Halcrow22e78fa2007-10-16 01:28:02 -070092 * Returns zero on success; non-zero on error
Michael Halcrow237fead2006-10-04 02:16:22 -070093 */
Michael Halcrowf66e8832008-04-29 00:59:51 -070094int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
95 size_t *length_size)
Michael Halcrow237fead2006-10-04 02:16:22 -070096{
97 int rc = 0;
98
99 (*length_size) = 0;
100 (*size) = 0;
101 if (data[0] < 192) {
102 /* One-byte length */
Michael Halcrowdddfa462007-02-12 00:53:44 -0800103 (*size) = (unsigned char)data[0];
Michael Halcrow237fead2006-10-04 02:16:22 -0700104 (*length_size) = 1;
105 } else if (data[0] < 224) {
106 /* Two-byte length */
Michael Halcrowdddfa462007-02-12 00:53:44 -0800107 (*size) = (((unsigned char)(data[0]) - 192) * 256);
108 (*size) += ((unsigned char)(data[1]) + 192);
Michael Halcrow237fead2006-10-04 02:16:22 -0700109 (*length_size) = 2;
110 } else if (data[0] == 255) {
Tyler Hicks48399c02012-01-14 16:46:46 +0100111 /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */
Michael Halcrow237fead2006-10-04 02:16:22 -0700112 ecryptfs_printk(KERN_ERR, "Five-byte packet length not "
113 "supported\n");
114 rc = -EINVAL;
115 goto out;
116 } else {
117 ecryptfs_printk(KERN_ERR, "Error parsing packet length\n");
118 rc = -EINVAL;
119 goto out;
120 }
121out:
122 return rc;
123}
124
125/**
Michael Halcrowf66e8832008-04-29 00:59:51 -0700126 * ecryptfs_write_packet_length
Michael Halcrow22e78fa2007-10-16 01:28:02 -0700127 * @dest: The byte array target into which to write the length. Must
Tyler Hicks48399c02012-01-14 16:46:46 +0100128 * have at least ECRYPTFS_MAX_PKT_LEN_SIZE bytes allocated.
Michael Halcrow237fead2006-10-04 02:16:22 -0700129 * @size: The length to write.
Michael Halcrow22e78fa2007-10-16 01:28:02 -0700130 * @packet_size_length: The number of bytes used to encode the packet
131 * length is written to this address.
Michael Halcrow237fead2006-10-04 02:16:22 -0700132 *
133 * Returns zero on success; non-zero on error.
134 */
Michael Halcrowf66e8832008-04-29 00:59:51 -0700135int ecryptfs_write_packet_length(char *dest, size_t size,
136 size_t *packet_size_length)
Michael Halcrow237fead2006-10-04 02:16:22 -0700137{
138 int rc = 0;
139
140 if (size < 192) {
141 dest[0] = size;
142 (*packet_size_length) = 1;
143 } else if (size < 65536) {
144 dest[0] = (((size - 192) / 256) + 192);
145 dest[1] = ((size - 192) % 256);
146 (*packet_size_length) = 2;
147 } else {
Tyler Hicks48399c02012-01-14 16:46:46 +0100148 /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */
Michael Halcrow237fead2006-10-04 02:16:22 -0700149 rc = -EINVAL;
150 ecryptfs_printk(KERN_WARNING,
Tyler Hicksf24b3882010-11-15 17:36:38 -0600151 "Unsupported packet size: [%zd]\n", size);
Michael Halcrow237fead2006-10-04 02:16:22 -0700152 }
153 return rc;
154}
155
Michael Halcrowdddfa462007-02-12 00:53:44 -0800156static int
157write_tag_64_packet(char *signature, struct ecryptfs_session_key *session_key,
158 char **packet, size_t *packet_len)
159{
160 size_t i = 0;
161 size_t data_len;
162 size_t packet_size_len;
163 char *message;
164 int rc;
165
166 /*
167 * ***** TAG 64 Packet Format *****
168 * | Content Type | 1 byte |
169 * | Key Identifier Size | 1 or 2 bytes |
170 * | Key Identifier | arbitrary |
171 * | Encrypted File Encryption Key Size | 1 or 2 bytes |
172 * | Encrypted File Encryption Key | arbitrary |
173 */
174 data_len = (5 + ECRYPTFS_SIG_SIZE_HEX
175 + session_key->encrypted_key_size);
176 *packet = kmalloc(data_len, GFP_KERNEL);
177 message = *packet;
178 if (!message) {
179 ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
180 rc = -ENOMEM;
181 goto out;
182 }
183 message[i++] = ECRYPTFS_TAG_64_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700184 rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
185 &packet_size_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800186 if (rc) {
187 ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet "
188 "header; cannot generate packet length\n");
189 goto out;
190 }
191 i += packet_size_len;
192 memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX);
193 i += ECRYPTFS_SIG_SIZE_HEX;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700194 rc = ecryptfs_write_packet_length(&message[i],
195 session_key->encrypted_key_size,
196 &packet_size_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800197 if (rc) {
198 ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet "
199 "header; cannot generate packet length\n");
200 goto out;
201 }
202 i += packet_size_len;
203 memcpy(&message[i], session_key->encrypted_key,
204 session_key->encrypted_key_size);
205 i += session_key->encrypted_key_size;
206 *packet_len = i;
207out:
208 return rc;
209}
210
211static int
Trevor Highland19e66a62008-02-06 01:38:36 -0800212parse_tag_65_packet(struct ecryptfs_session_key *session_key, u8 *cipher_code,
Michael Halcrowdddfa462007-02-12 00:53:44 -0800213 struct ecryptfs_message *msg)
214{
215 size_t i = 0;
216 char *data;
217 size_t data_len;
218 size_t m_size;
219 size_t message_len;
220 u16 checksum = 0;
221 u16 expected_checksum = 0;
222 int rc;
223
224 /*
225 * ***** TAG 65 Packet Format *****
226 * | Content Type | 1 byte |
227 * | Status Indicator | 1 byte |
228 * | File Encryption Key Size | 1 or 2 bytes |
229 * | File Encryption Key | arbitrary |
230 */
231 message_len = msg->data_len;
232 data = msg->data;
233 if (message_len < 4) {
234 rc = -EIO;
235 goto out;
236 }
237 if (data[i++] != ECRYPTFS_TAG_65_PACKET_TYPE) {
238 ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_65\n");
239 rc = -EIO;
240 goto out;
241 }
242 if (data[i++]) {
243 ecryptfs_printk(KERN_ERR, "Status indicator has non-zero value "
244 "[%d]\n", data[i-1]);
245 rc = -EIO;
246 goto out;
247 }
Michael Halcrowf66e8832008-04-29 00:59:51 -0700248 rc = ecryptfs_parse_packet_length(&data[i], &m_size, &data_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800249 if (rc) {
250 ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
251 "rc = [%d]\n", rc);
252 goto out;
253 }
254 i += data_len;
255 if (message_len < (i + m_size)) {
Tyler Hicks624ae522008-10-15 22:02:51 -0700256 ecryptfs_printk(KERN_ERR, "The message received from ecryptfsd "
257 "is shorter than expected\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -0800258 rc = -EIO;
259 goto out;
260 }
261 if (m_size < 3) {
262 ecryptfs_printk(KERN_ERR,
263 "The decrypted key is not long enough to "
264 "include a cipher code and checksum\n");
265 rc = -EIO;
266 goto out;
267 }
268 *cipher_code = data[i++];
269 /* The decrypted key includes 1 byte cipher code and 2 byte checksum */
270 session_key->decrypted_key_size = m_size - 3;
271 if (session_key->decrypted_key_size > ECRYPTFS_MAX_KEY_BYTES) {
272 ecryptfs_printk(KERN_ERR, "key_size [%d] larger than "
273 "the maximum key size [%d]\n",
274 session_key->decrypted_key_size,
275 ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES);
276 rc = -EIO;
277 goto out;
278 }
279 memcpy(session_key->decrypted_key, &data[i],
280 session_key->decrypted_key_size);
281 i += session_key->decrypted_key_size;
282 expected_checksum += (unsigned char)(data[i++]) << 8;
283 expected_checksum += (unsigned char)(data[i++]);
284 for (i = 0; i < session_key->decrypted_key_size; i++)
285 checksum += session_key->decrypted_key[i];
286 if (expected_checksum != checksum) {
287 ecryptfs_printk(KERN_ERR, "Invalid checksum for file "
288 "encryption key; expected [%x]; calculated "
289 "[%x]\n", expected_checksum, checksum);
290 rc = -EIO;
291 }
292out:
293 return rc;
294}
295
296
297static int
Trevor Highland19e66a62008-02-06 01:38:36 -0800298write_tag_66_packet(char *signature, u8 cipher_code,
Michael Halcrowdddfa462007-02-12 00:53:44 -0800299 struct ecryptfs_crypt_stat *crypt_stat, char **packet,
300 size_t *packet_len)
301{
302 size_t i = 0;
303 size_t j;
304 size_t data_len;
305 size_t checksum = 0;
306 size_t packet_size_len;
307 char *message;
308 int rc;
309
310 /*
311 * ***** TAG 66 Packet Format *****
312 * | Content Type | 1 byte |
313 * | Key Identifier Size | 1 or 2 bytes |
314 * | Key Identifier | arbitrary |
315 * | File Encryption Key Size | 1 or 2 bytes |
316 * | File Encryption Key | arbitrary |
317 */
318 data_len = (5 + ECRYPTFS_SIG_SIZE_HEX + crypt_stat->key_size);
319 *packet = kmalloc(data_len, GFP_KERNEL);
320 message = *packet;
321 if (!message) {
322 ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
323 rc = -ENOMEM;
324 goto out;
325 }
326 message[i++] = ECRYPTFS_TAG_66_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700327 rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
328 &packet_size_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800329 if (rc) {
330 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet "
331 "header; cannot generate packet length\n");
332 goto out;
333 }
334 i += packet_size_len;
335 memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX);
336 i += ECRYPTFS_SIG_SIZE_HEX;
337 /* The encrypted key includes 1 byte cipher code and 2 byte checksum */
Michael Halcrowf66e8832008-04-29 00:59:51 -0700338 rc = ecryptfs_write_packet_length(&message[i], crypt_stat->key_size + 3,
339 &packet_size_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800340 if (rc) {
341 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet "
342 "header; cannot generate packet length\n");
343 goto out;
344 }
345 i += packet_size_len;
346 message[i++] = cipher_code;
347 memcpy(&message[i], crypt_stat->key, crypt_stat->key_size);
348 i += crypt_stat->key_size;
349 for (j = 0; j < crypt_stat->key_size; j++)
350 checksum += crypt_stat->key[j];
351 message[i++] = (checksum / 256) % 256;
352 message[i++] = (checksum % 256);
353 *packet_len = i;
354out:
355 return rc;
356}
357
358static int
359parse_tag_67_packet(struct ecryptfs_key_record *key_rec,
360 struct ecryptfs_message *msg)
361{
362 size_t i = 0;
363 char *data;
364 size_t data_len;
365 size_t message_len;
366 int rc;
367
368 /*
369 * ***** TAG 65 Packet Format *****
370 * | Content Type | 1 byte |
371 * | Status Indicator | 1 byte |
372 * | Encrypted File Encryption Key Size | 1 or 2 bytes |
373 * | Encrypted File Encryption Key | arbitrary |
374 */
375 message_len = msg->data_len;
376 data = msg->data;
377 /* verify that everything through the encrypted FEK size is present */
378 if (message_len < 4) {
379 rc = -EIO;
Michael Halcrowdf261c52009-01-06 14:42:02 -0800380 printk(KERN_ERR "%s: message_len is [%zd]; minimum acceptable "
Michael Halcrowf66e8832008-04-29 00:59:51 -0700381 "message length is [%d]\n", __func__, message_len, 4);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800382 goto out;
383 }
384 if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) {
Michael Halcrowdddfa462007-02-12 00:53:44 -0800385 rc = -EIO;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700386 printk(KERN_ERR "%s: Type should be ECRYPTFS_TAG_67\n",
387 __func__);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800388 goto out;
389 }
390 if (data[i++]) {
Michael Halcrowdddfa462007-02-12 00:53:44 -0800391 rc = -EIO;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700392 printk(KERN_ERR "%s: Status indicator has non zero "
393 "value [%d]\n", __func__, data[i-1]);
394
Michael Halcrowdddfa462007-02-12 00:53:44 -0800395 goto out;
396 }
Michael Halcrowf66e8832008-04-29 00:59:51 -0700397 rc = ecryptfs_parse_packet_length(&data[i], &key_rec->enc_key_size,
398 &data_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800399 if (rc) {
400 ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
401 "rc = [%d]\n", rc);
402 goto out;
403 }
404 i += data_len;
405 if (message_len < (i + key_rec->enc_key_size)) {
Michael Halcrowdddfa462007-02-12 00:53:44 -0800406 rc = -EIO;
Michael Halcrowdf261c52009-01-06 14:42:02 -0800407 printk(KERN_ERR "%s: message_len [%zd]; max len is [%zd]\n",
Michael Halcrowf66e8832008-04-29 00:59:51 -0700408 __func__, message_len, (i + key_rec->enc_key_size));
Michael Halcrowdddfa462007-02-12 00:53:44 -0800409 goto out;
410 }
411 if (key_rec->enc_key_size > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
Michael Halcrowdddfa462007-02-12 00:53:44 -0800412 rc = -EIO;
Michael Halcrowdf261c52009-01-06 14:42:02 -0800413 printk(KERN_ERR "%s: Encrypted key_size [%zd] larger than "
Michael Halcrowf66e8832008-04-29 00:59:51 -0700414 "the maximum key size [%d]\n", __func__,
415 key_rec->enc_key_size,
416 ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800417 goto out;
418 }
419 memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size);
420out:
421 return rc;
422}
423
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +0100424/**
425 * ecryptfs_verify_version
426 * @version: The version number to confirm
427 *
428 * Returns zero on good version; non-zero otherwise
429 */
430static int ecryptfs_verify_version(u16 version)
431{
432 int rc = 0;
433 unsigned char major;
434 unsigned char minor;
435
436 major = ((version >> 8) & 0xFF);
437 minor = (version & 0xFF);
438 if (major != ECRYPTFS_VERSION_MAJOR) {
439 ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
440 "Expected [%d]; got [%d]\n",
441 ECRYPTFS_VERSION_MAJOR, major);
442 rc = -EINVAL;
443 goto out;
444 }
445 if (minor != ECRYPTFS_VERSION_MINOR) {
446 ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
447 "Expected [%d]; got [%d]\n",
448 ECRYPTFS_VERSION_MINOR, minor);
449 rc = -EINVAL;
450 goto out;
451 }
452out:
453 return rc;
454}
455
456/**
457 * ecryptfs_verify_auth_tok_from_key
458 * @auth_tok_key: key containing the authentication token
459 * @auth_tok: authentication token
460 *
461 * Returns zero on valid auth tok; -EINVAL otherwise
462 */
463static int
464ecryptfs_verify_auth_tok_from_key(struct key *auth_tok_key,
465 struct ecryptfs_auth_tok **auth_tok)
466{
467 int rc = 0;
468
469 (*auth_tok) = ecryptfs_get_key_payload_data(auth_tok_key);
470 if (ecryptfs_verify_version((*auth_tok)->version)) {
471 printk(KERN_ERR "Data structure version mismatch. Userspace "
472 "tools must match eCryptfs kernel module with major "
473 "version [%d] and minor version [%d]\n",
474 ECRYPTFS_VERSION_MAJOR, ECRYPTFS_VERSION_MINOR);
475 rc = -EINVAL;
476 goto out;
477 }
478 if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
479 && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
480 printk(KERN_ERR "Invalid auth_tok structure "
481 "returned from key query\n");
482 rc = -EINVAL;
483 goto out;
484 }
485out:
486 return rc;
487}
488
Michael Halcrowcd9d67d2007-10-16 01:28:04 -0700489static int
Michael Halcrow9c79f342009-01-06 14:41:57 -0800490ecryptfs_find_global_auth_tok_for_sig(
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +0100491 struct key **auth_tok_key,
492 struct ecryptfs_auth_tok **auth_tok,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800493 struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig)
494{
495 struct ecryptfs_global_auth_tok *walker;
496 int rc = 0;
497
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +0100498 (*auth_tok_key) = NULL;
499 (*auth_tok) = NULL;
Michael Halcrow9c79f342009-01-06 14:41:57 -0800500 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
501 list_for_each_entry(walker,
502 &mount_crypt_stat->global_auth_tok_list,
503 mount_crypt_stat_list) {
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +0100504 if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX))
505 continue;
506
507 if (walker->flags & ECRYPTFS_AUTH_TOK_INVALID) {
508 rc = -EINVAL;
Michael Halcrow9c79f342009-01-06 14:41:57 -0800509 goto out;
510 }
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +0100511
512 rc = key_validate(walker->global_auth_tok_key);
513 if (rc) {
514 if (rc == -EKEYEXPIRED)
515 goto out;
516 goto out_invalid_auth_tok;
517 }
518
Roberto Sassub5695d02011-03-21 16:00:55 +0100519 down_write(&(walker->global_auth_tok_key->sem));
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +0100520 rc = ecryptfs_verify_auth_tok_from_key(
521 walker->global_auth_tok_key, auth_tok);
522 if (rc)
Roberto Sassub5695d02011-03-21 16:00:55 +0100523 goto out_invalid_auth_tok_unlock;
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +0100524
525 (*auth_tok_key) = walker->global_auth_tok_key;
526 key_get(*auth_tok_key);
527 goto out;
Michael Halcrow9c79f342009-01-06 14:41:57 -0800528 }
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +0100529 rc = -ENOENT;
530 goto out;
Roberto Sassub5695d02011-03-21 16:00:55 +0100531out_invalid_auth_tok_unlock:
532 up_write(&(walker->global_auth_tok_key->sem));
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +0100533out_invalid_auth_tok:
534 printk(KERN_WARNING "Invalidating auth tok with sig = [%s]\n", sig);
535 walker->flags |= ECRYPTFS_AUTH_TOK_INVALID;
536 key_put(walker->global_auth_tok_key);
537 walker->global_auth_tok_key = NULL;
Michael Halcrow9c79f342009-01-06 14:41:57 -0800538out:
539 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
540 return rc;
541}
542
543/**
544 * ecryptfs_find_auth_tok_for_sig
545 * @auth_tok: Set to the matching auth_tok; NULL if not found
546 * @crypt_stat: inode crypt_stat crypto context
547 * @sig: Sig of auth_tok to find
548 *
549 * For now, this function simply looks at the registered auth_tok's
550 * linked off the mount_crypt_stat, so all the auth_toks that can be
551 * used must be registered at mount time. This function could
552 * potentially try a lot harder to find auth_tok's (e.g., by calling
553 * out to ecryptfsd to dynamically retrieve an auth_tok object) so
554 * that static registration of auth_tok's will no longer be necessary.
555 *
556 * Returns zero on no error; non-zero on error
557 */
558static int
559ecryptfs_find_auth_tok_for_sig(
Roberto Sassuaee683b2010-10-06 18:31:06 +0200560 struct key **auth_tok_key,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800561 struct ecryptfs_auth_tok **auth_tok,
562 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
563 char *sig)
564{
Michael Halcrow9c79f342009-01-06 14:41:57 -0800565 int rc = 0;
566
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +0100567 rc = ecryptfs_find_global_auth_tok_for_sig(auth_tok_key, auth_tok,
568 mount_crypt_stat, sig);
569 if (rc == -ENOENT) {
Roberto Sassuf16feb52010-10-06 18:31:32 +0200570 /* if the flag ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY is set in the
571 * mount_crypt_stat structure, we prevent to use auth toks that
572 * are not inserted through the ecryptfs_add_global_auth_tok
573 * function.
574 */
575 if (mount_crypt_stat->flags
576 & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY)
577 return -EINVAL;
578
Roberto Sassuaee683b2010-10-06 18:31:06 +0200579 rc = ecryptfs_keyring_auth_tok_for_sig(auth_tok_key, auth_tok,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800580 sig);
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +0100581 }
Michael Halcrow9c79f342009-01-06 14:41:57 -0800582 return rc;
583}
584
585/**
586 * write_tag_70_packet can gobble a lot of stack space. We stuff most
587 * of the function's parameters in a kmalloc'd struct to help reduce
588 * eCryptfs' overall stack usage.
589 */
590struct ecryptfs_write_tag_70_packet_silly_stack {
591 u8 cipher_code;
592 size_t max_packet_size;
593 size_t packet_size_len;
594 size_t block_aligned_filename_size;
595 size_t block_size;
596 size_t i;
597 size_t j;
598 size_t num_rand_bytes;
599 struct mutex *tfm_mutex;
600 char *block_aligned_filename;
601 struct ecryptfs_auth_tok *auth_tok;
Tyler Hicks8d08dab2011-05-17 00:50:33 -0500602 struct scatterlist src_sg[2];
603 struct scatterlist dst_sg[2];
Michael Halcrow9c79f342009-01-06 14:41:57 -0800604 struct blkcipher_desc desc;
605 char iv[ECRYPTFS_MAX_IV_BYTES];
606 char hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
607 char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
608 struct hash_desc hash_desc;
609 struct scatterlist hash_sg;
610};
611
612/**
613 * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK
614 * @filename: NULL-terminated filename string
615 *
616 * This is the simplest mechanism for achieving filename encryption in
617 * eCryptfs. It encrypts the given filename with the mount-wide
618 * filename encryption key (FNEK) and stores it in a packet to @dest,
619 * which the callee will encode and write directly into the dentry
620 * name.
621 */
622int
623ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
624 size_t *packet_size,
625 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
626 char *filename, size_t filename_size)
627{
628 struct ecryptfs_write_tag_70_packet_silly_stack *s;
Roberto Sassuaee683b2010-10-06 18:31:06 +0200629 struct key *auth_tok_key = NULL;
Michael Halcrow9c79f342009-01-06 14:41:57 -0800630 int rc = 0;
631
632 s = kmalloc(sizeof(*s), GFP_KERNEL);
633 if (!s) {
634 printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
Michael Halcrowdf261c52009-01-06 14:42:02 -0800635 "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
Julia Lawallf137f152010-08-11 12:11:41 +0200636 rc = -ENOMEM;
Michael Halcrow9c79f342009-01-06 14:41:57 -0800637 goto out;
638 }
639 s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
640 (*packet_size) = 0;
Roberto Sassu950983f2011-03-21 16:00:54 +0100641 rc = ecryptfs_find_auth_tok_for_sig(
642 &auth_tok_key,
643 &s->auth_tok, mount_crypt_stat,
644 mount_crypt_stat->global_default_fnek_sig);
645 if (rc) {
646 printk(KERN_ERR "%s: Error attempting to find auth tok for "
647 "fnek sig [%s]; rc = [%d]\n", __func__,
648 mount_crypt_stat->global_default_fnek_sig, rc);
649 goto out;
650 }
Michael Halcrow9c79f342009-01-06 14:41:57 -0800651 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(
652 &s->desc.tfm,
653 &s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name);
654 if (unlikely(rc)) {
655 printk(KERN_ERR "Internal error whilst attempting to get "
656 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
657 mount_crypt_stat->global_default_fn_cipher_name, rc);
658 goto out;
659 }
660 mutex_lock(s->tfm_mutex);
661 s->block_size = crypto_blkcipher_blocksize(s->desc.tfm);
662 /* Plus one for the \0 separator between the random prefix
663 * and the plaintext filename */
664 s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1);
665 s->block_aligned_filename_size = (s->num_rand_bytes + filename_size);
666 if ((s->block_aligned_filename_size % s->block_size) != 0) {
667 s->num_rand_bytes += (s->block_size
668 - (s->block_aligned_filename_size
669 % s->block_size));
670 s->block_aligned_filename_size = (s->num_rand_bytes
671 + filename_size);
672 }
673 /* Octet 0: Tag 70 identifier
674 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
675 * and block-aligned encrypted filename size)
676 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
677 * Octet N2-N3: Cipher identifier (1 octet)
678 * Octets N3-N4: Block-aligned encrypted filename
679 * - Consists of a minimum number of random characters, a \0
680 * separator, and then the filename */
Tyler Hicks4a266202011-11-05 13:45:08 -0400681 s->max_packet_size = (ECRYPTFS_TAG_70_MAX_METADATA_SIZE
Michael Halcrow9c79f342009-01-06 14:41:57 -0800682 + s->block_aligned_filename_size);
683 if (dest == NULL) {
684 (*packet_size) = s->max_packet_size;
685 goto out_unlock;
686 }
687 if (s->max_packet_size > (*remaining_bytes)) {
Michael Halcrowa8f12862009-01-06 14:42:03 -0800688 printk(KERN_WARNING "%s: Require [%zd] bytes to write; only "
689 "[%zd] available\n", __func__, s->max_packet_size,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800690 (*remaining_bytes));
691 rc = -EINVAL;
692 goto out_unlock;
693 }
694 s->block_aligned_filename = kzalloc(s->block_aligned_filename_size,
695 GFP_KERNEL);
696 if (!s->block_aligned_filename) {
697 printk(KERN_ERR "%s: Out of kernel memory whilst attempting to "
Michael Halcrowdf261c52009-01-06 14:42:02 -0800698 "kzalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800699 s->block_aligned_filename_size);
700 rc = -ENOMEM;
701 goto out_unlock;
702 }
703 s->i = 0;
704 dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE;
705 rc = ecryptfs_write_packet_length(&dest[s->i],
706 (ECRYPTFS_SIG_SIZE
707 + 1 /* Cipher code */
708 + s->block_aligned_filename_size),
709 &s->packet_size_len);
710 if (rc) {
711 printk(KERN_ERR "%s: Error generating tag 70 packet "
712 "header; cannot generate packet length; rc = [%d]\n",
713 __func__, rc);
714 goto out_free_unlock;
715 }
716 s->i += s->packet_size_len;
717 ecryptfs_from_hex(&dest[s->i],
718 mount_crypt_stat->global_default_fnek_sig,
719 ECRYPTFS_SIG_SIZE);
720 s->i += ECRYPTFS_SIG_SIZE;
721 s->cipher_code = ecryptfs_code_for_cipher_string(
722 mount_crypt_stat->global_default_fn_cipher_name,
723 mount_crypt_stat->global_default_fn_cipher_key_bytes);
724 if (s->cipher_code == 0) {
725 printk(KERN_WARNING "%s: Unable to generate code for "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800726 "cipher [%s] with key bytes [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800727 mount_crypt_stat->global_default_fn_cipher_name,
728 mount_crypt_stat->global_default_fn_cipher_key_bytes);
729 rc = -EINVAL;
730 goto out_free_unlock;
731 }
732 dest[s->i++] = s->cipher_code;
Michael Halcrow9c79f342009-01-06 14:41:57 -0800733 /* TODO: Support other key modules than passphrase for
734 * filename encryption */
Tyler Hicksdf6ad332009-08-21 04:27:46 -0500735 if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {
736 rc = -EOPNOTSUPP;
737 printk(KERN_INFO "%s: Filename encryption only supports "
738 "password tokens\n", __func__);
739 goto out_free_unlock;
740 }
Michael Halcrow9c79f342009-01-06 14:41:57 -0800741 sg_init_one(
742 &s->hash_sg,
743 (u8 *)s->auth_tok->token.password.session_key_encryption_key,
744 s->auth_tok->token.password.session_key_encryption_key_bytes);
745 s->hash_desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
746 s->hash_desc.tfm = crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST, 0,
747 CRYPTO_ALG_ASYNC);
748 if (IS_ERR(s->hash_desc.tfm)) {
749 rc = PTR_ERR(s->hash_desc.tfm);
750 printk(KERN_ERR "%s: Error attempting to "
751 "allocate hash crypto context; rc = [%d]\n",
752 __func__, rc);
753 goto out_free_unlock;
754 }
755 rc = crypto_hash_init(&s->hash_desc);
756 if (rc) {
757 printk(KERN_ERR
758 "%s: Error initializing crypto hash; rc = [%d]\n",
759 __func__, rc);
760 goto out_release_free_unlock;
761 }
762 rc = crypto_hash_update(
763 &s->hash_desc, &s->hash_sg,
764 s->auth_tok->token.password.session_key_encryption_key_bytes);
765 if (rc) {
766 printk(KERN_ERR
767 "%s: Error updating crypto hash; rc = [%d]\n",
768 __func__, rc);
769 goto out_release_free_unlock;
770 }
771 rc = crypto_hash_final(&s->hash_desc, s->hash);
772 if (rc) {
773 printk(KERN_ERR
774 "%s: Error finalizing crypto hash; rc = [%d]\n",
775 __func__, rc);
776 goto out_release_free_unlock;
777 }
778 for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) {
779 s->block_aligned_filename[s->j] =
780 s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)];
781 if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)
782 == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) {
783 sg_init_one(&s->hash_sg, (u8 *)s->hash,
784 ECRYPTFS_TAG_70_DIGEST_SIZE);
785 rc = crypto_hash_init(&s->hash_desc);
786 if (rc) {
787 printk(KERN_ERR
788 "%s: Error initializing crypto hash; "
789 "rc = [%d]\n", __func__, rc);
790 goto out_release_free_unlock;
791 }
792 rc = crypto_hash_update(&s->hash_desc, &s->hash_sg,
793 ECRYPTFS_TAG_70_DIGEST_SIZE);
794 if (rc) {
795 printk(KERN_ERR
796 "%s: Error updating crypto hash; "
797 "rc = [%d]\n", __func__, rc);
798 goto out_release_free_unlock;
799 }
800 rc = crypto_hash_final(&s->hash_desc, s->tmp_hash);
801 if (rc) {
802 printk(KERN_ERR
803 "%s: Error finalizing crypto hash; "
804 "rc = [%d]\n", __func__, rc);
805 goto out_release_free_unlock;
806 }
807 memcpy(s->hash, s->tmp_hash,
808 ECRYPTFS_TAG_70_DIGEST_SIZE);
809 }
810 if (s->block_aligned_filename[s->j] == '\0')
811 s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL;
812 }
813 memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename,
814 filename_size);
815 rc = virt_to_scatterlist(s->block_aligned_filename,
Tyler Hicks8d08dab2011-05-17 00:50:33 -0500816 s->block_aligned_filename_size, s->src_sg, 2);
817 if (rc < 1) {
Michael Halcrow9c79f342009-01-06 14:41:57 -0800818 printk(KERN_ERR "%s: Internal error whilst attempting to "
Tyler Hicks8d08dab2011-05-17 00:50:33 -0500819 "convert filename memory to scatterlist; rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800820 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800821 s->block_aligned_filename_size);
822 goto out_release_free_unlock;
823 }
824 rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size,
Tyler Hicks8d08dab2011-05-17 00:50:33 -0500825 s->dst_sg, 2);
826 if (rc < 1) {
Michael Halcrow9c79f342009-01-06 14:41:57 -0800827 printk(KERN_ERR "%s: Internal error whilst attempting to "
828 "convert encrypted filename memory to scatterlist; "
Tyler Hicks8d08dab2011-05-17 00:50:33 -0500829 "rc = [%d]. block_aligned_filename_size = [%zd]\n",
830 __func__, rc, s->block_aligned_filename_size);
Michael Halcrow9c79f342009-01-06 14:41:57 -0800831 goto out_release_free_unlock;
832 }
833 /* The characters in the first block effectively do the job
834 * of the IV here, so we just use 0's for the IV. Note the
835 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
836 * >= ECRYPTFS_MAX_IV_BYTES. */
837 memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
838 s->desc.info = s->iv;
839 rc = crypto_blkcipher_setkey(
840 s->desc.tfm,
841 s->auth_tok->token.password.session_key_encryption_key,
842 mount_crypt_stat->global_default_fn_cipher_key_bytes);
843 if (rc < 0) {
844 printk(KERN_ERR "%s: Error setting key for crypto context; "
845 "rc = [%d]. s->auth_tok->token.password.session_key_"
846 "encryption_key = [0x%p]; mount_crypt_stat->"
Michael Halcrowdf261c52009-01-06 14:42:02 -0800847 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800848 rc,
849 s->auth_tok->token.password.session_key_encryption_key,
850 mount_crypt_stat->global_default_fn_cipher_key_bytes);
851 goto out_release_free_unlock;
852 }
Tyler Hicks8d08dab2011-05-17 00:50:33 -0500853 rc = crypto_blkcipher_encrypt_iv(&s->desc, s->dst_sg, s->src_sg,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800854 s->block_aligned_filename_size);
855 if (rc) {
856 printk(KERN_ERR "%s: Error attempting to encrypt filename; "
857 "rc = [%d]\n", __func__, rc);
858 goto out_release_free_unlock;
859 }
860 s->i += s->block_aligned_filename_size;
861 (*packet_size) = s->i;
862 (*remaining_bytes) -= (*packet_size);
863out_release_free_unlock:
864 crypto_free_hash(s->hash_desc.tfm);
865out_free_unlock:
Johannes Weiner00fcf2c2009-03-31 15:24:42 -0700866 kzfree(s->block_aligned_filename);
Michael Halcrow9c79f342009-01-06 14:41:57 -0800867out_unlock:
868 mutex_unlock(s->tfm_mutex);
869out:
Roberto Sassub5695d02011-03-21 16:00:55 +0100870 if (auth_tok_key) {
871 up_write(&(auth_tok_key->sem));
Roberto Sassuaee683b2010-10-06 18:31:06 +0200872 key_put(auth_tok_key);
Roberto Sassub5695d02011-03-21 16:00:55 +0100873 }
Michael Halcrow9c79f342009-01-06 14:41:57 -0800874 kfree(s);
875 return rc;
876}
877
878struct ecryptfs_parse_tag_70_packet_silly_stack {
879 u8 cipher_code;
880 size_t max_packet_size;
881 size_t packet_size_len;
882 size_t parsed_tag_70_packet_size;
883 size_t block_aligned_filename_size;
884 size_t block_size;
885 size_t i;
886 struct mutex *tfm_mutex;
887 char *decrypted_filename;
888 struct ecryptfs_auth_tok *auth_tok;
Tyler Hicks8d08dab2011-05-17 00:50:33 -0500889 struct scatterlist src_sg[2];
890 struct scatterlist dst_sg[2];
Michael Halcrow9c79f342009-01-06 14:41:57 -0800891 struct blkcipher_desc desc;
892 char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1];
893 char iv[ECRYPTFS_MAX_IV_BYTES];
894 char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE];
895};
896
897/**
898 * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet
899 * @filename: This function kmalloc's the memory for the filename
Michael Halcrow7d8bc2b2009-01-06 14:42:04 -0800900 * @filename_size: This function sets this to the amount of memory
901 * kmalloc'd for the filename
902 * @packet_size: This function sets this to the the number of octets
903 * in the packet parsed
904 * @mount_crypt_stat: The mount-wide cryptographic context
905 * @data: The memory location containing the start of the tag 70
906 * packet
907 * @max_packet_size: The maximum legal size of the packet to be parsed
908 * from @data
909 *
910 * Returns zero on success; non-zero otherwise
Michael Halcrow9c79f342009-01-06 14:41:57 -0800911 */
912int
913ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
914 size_t *packet_size,
915 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
916 char *data, size_t max_packet_size)
917{
918 struct ecryptfs_parse_tag_70_packet_silly_stack *s;
Roberto Sassuaee683b2010-10-06 18:31:06 +0200919 struct key *auth_tok_key = NULL;
Michael Halcrow9c79f342009-01-06 14:41:57 -0800920 int rc = 0;
921
922 (*packet_size) = 0;
923 (*filename_size) = 0;
924 (*filename) = NULL;
925 s = kmalloc(sizeof(*s), GFP_KERNEL);
926 if (!s) {
927 printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800928 "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
Julia Lawallf137f152010-08-11 12:11:41 +0200929 rc = -ENOMEM;
Michael Halcrow9c79f342009-01-06 14:41:57 -0800930 goto out;
931 }
932 s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
Tyler Hicks4a266202011-11-05 13:45:08 -0400933 if (max_packet_size < ECRYPTFS_TAG_70_MIN_METADATA_SIZE) {
Michael Halcrowdf261c52009-01-06 14:42:02 -0800934 printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be "
Michael Halcrow9c79f342009-01-06 14:41:57 -0800935 "at least [%d]\n", __func__, max_packet_size,
Tyler Hicks4a266202011-11-05 13:45:08 -0400936 ECRYPTFS_TAG_70_MIN_METADATA_SIZE);
Michael Halcrow9c79f342009-01-06 14:41:57 -0800937 rc = -EINVAL;
938 goto out;
939 }
940 /* Octet 0: Tag 70 identifier
941 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
942 * and block-aligned encrypted filename size)
943 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
944 * Octet N2-N3: Cipher identifier (1 octet)
945 * Octets N3-N4: Block-aligned encrypted filename
946 * - Consists of a minimum number of random numbers, a \0
947 * separator, and then the filename */
948 if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) {
949 printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be "
950 "tag [0x%.2x]\n", __func__,
951 data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE);
952 rc = -EINVAL;
953 goto out;
954 }
955 rc = ecryptfs_parse_packet_length(&data[(*packet_size)],
956 &s->parsed_tag_70_packet_size,
957 &s->packet_size_len);
958 if (rc) {
959 printk(KERN_WARNING "%s: Error parsing packet length; "
960 "rc = [%d]\n", __func__, rc);
961 goto out;
962 }
963 s->block_aligned_filename_size = (s->parsed_tag_70_packet_size
964 - ECRYPTFS_SIG_SIZE - 1);
965 if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size)
966 > max_packet_size) {
Michael Halcrowa8f12862009-01-06 14:42:03 -0800967 printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet "
968 "size is [%zd]\n", __func__, max_packet_size,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800969 (1 + s->packet_size_len + 1
970 + s->block_aligned_filename_size));
971 rc = -EINVAL;
972 goto out;
973 }
974 (*packet_size) += s->packet_size_len;
975 ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)],
976 ECRYPTFS_SIG_SIZE);
977 s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0';
978 (*packet_size) += ECRYPTFS_SIG_SIZE;
979 s->cipher_code = data[(*packet_size)++];
980 rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code);
981 if (rc) {
982 printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n",
983 __func__, s->cipher_code);
984 goto out;
985 }
Roberto Sassu950983f2011-03-21 16:00:54 +0100986 rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key,
987 &s->auth_tok, mount_crypt_stat,
988 s->fnek_sig_hex);
989 if (rc) {
990 printk(KERN_ERR "%s: Error attempting to find auth tok for "
991 "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex,
992 rc);
993 goto out;
994 }
Michael Halcrow9c79f342009-01-06 14:41:57 -0800995 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm,
996 &s->tfm_mutex,
997 s->cipher_string);
998 if (unlikely(rc)) {
999 printk(KERN_ERR "Internal error whilst attempting to get "
1000 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1001 s->cipher_string, rc);
1002 goto out;
1003 }
1004 mutex_lock(s->tfm_mutex);
1005 rc = virt_to_scatterlist(&data[(*packet_size)],
Tyler Hicks8d08dab2011-05-17 00:50:33 -05001006 s->block_aligned_filename_size, s->src_sg, 2);
1007 if (rc < 1) {
Michael Halcrow9c79f342009-01-06 14:41:57 -08001008 printk(KERN_ERR "%s: Internal error whilst attempting to "
1009 "convert encrypted filename memory to scatterlist; "
Tyler Hicks8d08dab2011-05-17 00:50:33 -05001010 "rc = [%d]. block_aligned_filename_size = [%zd]\n",
1011 __func__, rc, s->block_aligned_filename_size);
Michael Halcrow9c79f342009-01-06 14:41:57 -08001012 goto out_unlock;
1013 }
1014 (*packet_size) += s->block_aligned_filename_size;
1015 s->decrypted_filename = kmalloc(s->block_aligned_filename_size,
1016 GFP_KERNEL);
1017 if (!s->decrypted_filename) {
1018 printk(KERN_ERR "%s: Out of memory whilst attempting to "
Michael Halcrowa8f12862009-01-06 14:42:03 -08001019 "kmalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -08001020 s->block_aligned_filename_size);
1021 rc = -ENOMEM;
1022 goto out_unlock;
1023 }
1024 rc = virt_to_scatterlist(s->decrypted_filename,
Tyler Hicks8d08dab2011-05-17 00:50:33 -05001025 s->block_aligned_filename_size, s->dst_sg, 2);
1026 if (rc < 1) {
Michael Halcrow9c79f342009-01-06 14:41:57 -08001027 printk(KERN_ERR "%s: Internal error whilst attempting to "
1028 "convert decrypted filename memory to scatterlist; "
Tyler Hicks8d08dab2011-05-17 00:50:33 -05001029 "rc = [%d]. block_aligned_filename_size = [%zd]\n",
1030 __func__, rc, s->block_aligned_filename_size);
Michael Halcrow9c79f342009-01-06 14:41:57 -08001031 goto out_free_unlock;
1032 }
1033 /* The characters in the first block effectively do the job of
1034 * the IV here, so we just use 0's for the IV. Note the
1035 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
1036 * >= ECRYPTFS_MAX_IV_BYTES. */
1037 memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
1038 s->desc.info = s->iv;
Michael Halcrow9c79f342009-01-06 14:41:57 -08001039 /* TODO: Support other key modules than passphrase for
1040 * filename encryption */
Tyler Hicksdf6ad332009-08-21 04:27:46 -05001041 if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {
1042 rc = -EOPNOTSUPP;
1043 printk(KERN_INFO "%s: Filename encryption only supports "
1044 "password tokens\n", __func__);
1045 goto out_free_unlock;
1046 }
Michael Halcrow9c79f342009-01-06 14:41:57 -08001047 rc = crypto_blkcipher_setkey(
1048 s->desc.tfm,
1049 s->auth_tok->token.password.session_key_encryption_key,
1050 mount_crypt_stat->global_default_fn_cipher_key_bytes);
1051 if (rc < 0) {
1052 printk(KERN_ERR "%s: Error setting key for crypto context; "
1053 "rc = [%d]. s->auth_tok->token.password.session_key_"
1054 "encryption_key = [0x%p]; mount_crypt_stat->"
Michael Halcrowdf261c52009-01-06 14:42:02 -08001055 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -08001056 rc,
1057 s->auth_tok->token.password.session_key_encryption_key,
1058 mount_crypt_stat->global_default_fn_cipher_key_bytes);
1059 goto out_free_unlock;
1060 }
Tyler Hicks8d08dab2011-05-17 00:50:33 -05001061 rc = crypto_blkcipher_decrypt_iv(&s->desc, s->dst_sg, s->src_sg,
Michael Halcrow9c79f342009-01-06 14:41:57 -08001062 s->block_aligned_filename_size);
1063 if (rc) {
1064 printk(KERN_ERR "%s: Error attempting to decrypt filename; "
1065 "rc = [%d]\n", __func__, rc);
1066 goto out_free_unlock;
1067 }
1068 s->i = 0;
1069 while (s->decrypted_filename[s->i] != '\0'
1070 && s->i < s->block_aligned_filename_size)
1071 s->i++;
1072 if (s->i == s->block_aligned_filename_size) {
1073 printk(KERN_WARNING "%s: Invalid tag 70 packet; could not "
1074 "find valid separator between random characters and "
1075 "the filename\n", __func__);
1076 rc = -EINVAL;
1077 goto out_free_unlock;
1078 }
1079 s->i++;
1080 (*filename_size) = (s->block_aligned_filename_size - s->i);
1081 if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) {
Michael Halcrowdf261c52009-01-06 14:42:02 -08001082 printk(KERN_WARNING "%s: Filename size is [%zd], which is "
Michael Halcrow9c79f342009-01-06 14:41:57 -08001083 "invalid\n", __func__, (*filename_size));
1084 rc = -EINVAL;
1085 goto out_free_unlock;
1086 }
1087 (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL);
1088 if (!(*filename)) {
1089 printk(KERN_ERR "%s: Out of memory whilst attempting to "
Michael Halcrowa8f12862009-01-06 14:42:03 -08001090 "kmalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -08001091 ((*filename_size) + 1));
1092 rc = -ENOMEM;
1093 goto out_free_unlock;
1094 }
1095 memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size));
1096 (*filename)[(*filename_size)] = '\0';
1097out_free_unlock:
1098 kfree(s->decrypted_filename);
1099out_unlock:
1100 mutex_unlock(s->tfm_mutex);
1101out:
1102 if (rc) {
1103 (*packet_size) = 0;
1104 (*filename_size) = 0;
1105 (*filename) = NULL;
1106 }
Roberto Sassub5695d02011-03-21 16:00:55 +01001107 if (auth_tok_key) {
1108 up_write(&(auth_tok_key->sem));
Roberto Sassuaee683b2010-10-06 18:31:06 +02001109 key_put(auth_tok_key);
Roberto Sassub5695d02011-03-21 16:00:55 +01001110 }
Michael Halcrow9c79f342009-01-06 14:41:57 -08001111 kfree(s);
1112 return rc;
1113}
1114
1115static int
Michael Halcrowcd9d67d2007-10-16 01:28:04 -07001116ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok)
1117{
1118 int rc = 0;
1119
1120 (*sig) = NULL;
1121 switch (auth_tok->token_type) {
1122 case ECRYPTFS_PASSWORD:
1123 (*sig) = auth_tok->token.password.signature;
1124 break;
1125 case ECRYPTFS_PRIVATE_KEY:
1126 (*sig) = auth_tok->token.private_key.signature;
1127 break;
1128 default:
1129 printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n",
1130 auth_tok->token_type);
1131 rc = -EINVAL;
1132 }
1133 return rc;
1134}
1135
Michael Halcrowdddfa462007-02-12 00:53:44 -08001136/**
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001137 * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok.
1138 * @auth_tok: The key authentication token used to decrypt the session key
1139 * @crypt_stat: The cryptographic context
Michael Halcrowdddfa462007-02-12 00:53:44 -08001140 *
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001141 * Returns zero on success; non-zero error otherwise.
Michael Halcrowdddfa462007-02-12 00:53:44 -08001142 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07001143static int
1144decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1145 struct ecryptfs_crypt_stat *crypt_stat)
Michael Halcrowdddfa462007-02-12 00:53:44 -08001146{
Trevor Highland19e66a62008-02-06 01:38:36 -08001147 u8 cipher_code = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001148 struct ecryptfs_msg_ctx *msg_ctx;
1149 struct ecryptfs_message *msg = NULL;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001150 char *auth_tok_sig;
Geyslan G. Bem3edc8372013-10-11 16:49:16 -03001151 char *payload = NULL;
Simon Quefa519962013-01-17 11:18:20 -08001152 size_t payload_len = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001153 int rc;
1154
Michael Halcrow5dda6992007-10-16 01:28:06 -07001155 rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok);
1156 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001157 printk(KERN_ERR "Unrecognized auth tok type: [%d]\n",
1158 auth_tok->token_type);
1159 goto out;
1160 }
1161 rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key),
Tyler Hicks624ae522008-10-15 22:02:51 -07001162 &payload, &payload_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001163 if (rc) {
Michael Halcrowf66e8832008-04-29 00:59:51 -07001164 ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001165 goto out;
1166 }
Tyler Hicks624ae522008-10-15 22:02:51 -07001167 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001168 if (rc) {
Tyler Hicks624ae522008-10-15 22:02:51 -07001169 ecryptfs_printk(KERN_ERR, "Error sending message to "
Kees Cook290502b2013-02-28 00:39:37 -08001170 "ecryptfsd: %d\n", rc);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001171 goto out;
1172 }
1173 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1174 if (rc) {
1175 ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet "
1176 "from the user space daemon\n");
1177 rc = -EIO;
1178 goto out;
1179 }
1180 rc = parse_tag_65_packet(&(auth_tok->session_key),
1181 &cipher_code, msg);
1182 if (rc) {
1183 printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n",
1184 rc);
1185 goto out;
1186 }
1187 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1188 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1189 auth_tok->session_key.decrypted_key_size);
1190 crypt_stat->key_size = auth_tok->session_key.decrypted_key_size;
1191 rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code);
1192 if (rc) {
1193 ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n",
1194 cipher_code)
1195 goto out;
1196 }
1197 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1198 if (ecryptfs_verbosity > 0) {
1199 ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n");
1200 ecryptfs_dump_hex(crypt_stat->key,
1201 crypt_stat->key_size);
1202 }
1203out:
Tim Gardner3a467412013-02-12 10:56:54 -07001204 kfree(msg);
Geyslan G. Bem3edc8372013-10-11 16:49:16 -03001205 kfree(payload);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001206 return rc;
1207}
1208
1209static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
1210{
Michael Halcrowdddfa462007-02-12 00:53:44 -08001211 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
Michael Halcrowe0869cc2007-10-16 01:27:55 -07001212 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001213
Michael Halcrowe0869cc2007-10-16 01:27:55 -07001214 list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp,
1215 auth_tok_list_head, list) {
1216 list_del(&auth_tok_list_item->list);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001217 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1218 auth_tok_list_item);
1219 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001220}
1221
1222struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
1223
Michael Halcrowdddfa462007-02-12 00:53:44 -08001224/**
1225 * parse_tag_1_packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001226 * @crypt_stat: The cryptographic context to modify based on packet contents
Michael Halcrowdddfa462007-02-12 00:53:44 -08001227 * @data: The raw bytes of the packet.
1228 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001229 * a new authentication token will be placed at the
1230 * end of this list for this packet.
Michael Halcrowdddfa462007-02-12 00:53:44 -08001231 * @new_auth_tok: Pointer to a pointer to memory that this function
1232 * allocates; sets the memory address of the pointer to
1233 * NULL on error. This object is added to the
1234 * auth_tok_list.
1235 * @packet_size: This function writes the size of the parsed packet
1236 * into this memory location; zero on error.
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001237 * @max_packet_size: The maximum allowable packet size
Michael Halcrowdddfa462007-02-12 00:53:44 -08001238 *
1239 * Returns zero on success; non-zero on error.
1240 */
1241static int
1242parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
1243 unsigned char *data, struct list_head *auth_tok_list,
1244 struct ecryptfs_auth_tok **new_auth_tok,
1245 size_t *packet_size, size_t max_packet_size)
1246{
1247 size_t body_size;
1248 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1249 size_t length_size;
1250 int rc = 0;
1251
1252 (*packet_size) = 0;
1253 (*new_auth_tok) = NULL;
Michael Halcrow132181792007-10-16 01:27:56 -07001254 /**
1255 * This format is inspired by OpenPGP; see RFC 2440
1256 * packet tag 1
1257 *
1258 * Tag 1 identifier (1 byte)
1259 * Max Tag 1 packet size (max 3 bytes)
1260 * Version (1 byte)
1261 * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE)
1262 * Cipher identifier (1 byte)
1263 * Encrypted key size (arbitrary)
1264 *
1265 * 12 bytes minimum packet size
Michael Halcrowdddfa462007-02-12 00:53:44 -08001266 */
Michael Halcrow132181792007-10-16 01:27:56 -07001267 if (unlikely(max_packet_size < 12)) {
1268 printk(KERN_ERR "Invalid max packet size; must be >=12\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001269 rc = -EINVAL;
1270 goto out;
1271 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001272 if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) {
Michael Halcrow132181792007-10-16 01:27:56 -07001273 printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n",
1274 ECRYPTFS_TAG_1_PACKET_TYPE);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001275 rc = -EINVAL;
1276 goto out;
1277 }
1278 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1279 * at end of function upon failure */
1280 auth_tok_list_item =
Michael Halcrow132181792007-10-16 01:27:56 -07001281 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache,
1282 GFP_KERNEL);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001283 if (!auth_tok_list_item) {
Michael Halcrow132181792007-10-16 01:27:56 -07001284 printk(KERN_ERR "Unable to allocate memory\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001285 rc = -ENOMEM;
1286 goto out;
1287 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001288 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001289 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1290 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001291 if (rc) {
Michael Halcrow132181792007-10-16 01:27:56 -07001292 printk(KERN_WARNING "Error parsing packet length; "
1293 "rc = [%d]\n", rc);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001294 goto out_free;
1295 }
Michael Halcrow132181792007-10-16 01:27:56 -07001296 if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001297 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001298 rc = -EINVAL;
1299 goto out_free;
1300 }
1301 (*packet_size) += length_size;
1302 if (unlikely((*packet_size) + body_size > max_packet_size)) {
Michael Halcrow132181792007-10-16 01:27:56 -07001303 printk(KERN_WARNING "Packet size exceeds max\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001304 rc = -EINVAL;
1305 goto out_free;
1306 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001307 if (unlikely(data[(*packet_size)++] != 0x03)) {
Michael Halcrow132181792007-10-16 01:27:56 -07001308 printk(KERN_WARNING "Unknown version number [%d]\n",
1309 data[(*packet_size) - 1]);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001310 rc = -EINVAL;
1311 goto out_free;
1312 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001313 ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
1314 &data[(*packet_size)], ECRYPTFS_SIG_SIZE);
1315 *packet_size += ECRYPTFS_SIG_SIZE;
1316 /* This byte is skipped because the kernel does not need to
1317 * know which public key encryption algorithm was used */
1318 (*packet_size)++;
1319 (*new_auth_tok)->session_key.encrypted_key_size =
Michael Halcrow132181792007-10-16 01:27:56 -07001320 body_size - (ECRYPTFS_SIG_SIZE + 2);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001321 if ((*new_auth_tok)->session_key.encrypted_key_size
1322 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
Michael Halcrow132181792007-10-16 01:27:56 -07001323 printk(KERN_WARNING "Tag 1 packet contains key larger "
1324 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001325 rc = -EINVAL;
1326 goto out;
1327 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001328 memcpy((*new_auth_tok)->session_key.encrypted_key,
Michael Halcrow132181792007-10-16 01:27:56 -07001329 &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2)));
Michael Halcrowdddfa462007-02-12 00:53:44 -08001330 (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size;
1331 (*new_auth_tok)->session_key.flags &=
1332 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1333 (*new_auth_tok)->session_key.flags |=
1334 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
1335 (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY;
Michael Halcrow132181792007-10-16 01:27:56 -07001336 (*new_auth_tok)->flags = 0;
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001337 (*new_auth_tok)->session_key.flags &=
1338 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1339 (*new_auth_tok)->session_key.flags &=
1340 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001341 list_add(&auth_tok_list_item->list, auth_tok_list);
1342 goto out;
1343out_free:
1344 (*new_auth_tok) = NULL;
1345 memset(auth_tok_list_item, 0,
1346 sizeof(struct ecryptfs_auth_tok_list_item));
1347 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1348 auth_tok_list_item);
1349out:
1350 if (rc)
1351 (*packet_size) = 0;
1352 return rc;
1353}
1354
Michael Halcrow237fead2006-10-04 02:16:22 -07001355/**
1356 * parse_tag_3_packet
1357 * @crypt_stat: The cryptographic context to modify based on packet
1358 * contents.
1359 * @data: The raw bytes of the packet.
1360 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
1361 * a new authentication token will be placed at the end
1362 * of this list for this packet.
1363 * @new_auth_tok: Pointer to a pointer to memory that this function
1364 * allocates; sets the memory address of the pointer to
1365 * NULL on error. This object is added to the
1366 * auth_tok_list.
1367 * @packet_size: This function writes the size of the parsed packet
1368 * into this memory location; zero on error.
1369 * @max_packet_size: maximum number of bytes to parse
1370 *
1371 * Returns zero on success; non-zero on error.
1372 */
1373static int
1374parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
1375 unsigned char *data, struct list_head *auth_tok_list,
1376 struct ecryptfs_auth_tok **new_auth_tok,
1377 size_t *packet_size, size_t max_packet_size)
1378{
Michael Halcrow237fead2006-10-04 02:16:22 -07001379 size_t body_size;
1380 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1381 size_t length_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001382 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001383
1384 (*packet_size) = 0;
1385 (*new_auth_tok) = NULL;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001386 /**
1387 *This format is inspired by OpenPGP; see RFC 2440
1388 * packet tag 3
1389 *
1390 * Tag 3 identifier (1 byte)
1391 * Max Tag 3 packet size (max 3 bytes)
1392 * Version (1 byte)
1393 * Cipher code (1 byte)
1394 * S2K specifier (1 byte)
1395 * Hash identifier (1 byte)
1396 * Salt (ECRYPTFS_SALT_SIZE)
1397 * Hash iterations (1 byte)
1398 * Encrypted key (arbitrary)
1399 *
1400 * (ECRYPTFS_SALT_SIZE + 7) minimum packet size
Michael Halcrow237fead2006-10-04 02:16:22 -07001401 */
Michael Halcrowc59becf2007-10-16 01:27:56 -07001402 if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) {
1403 printk(KERN_ERR "Max packet size too large\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001404 rc = -EINVAL;
1405 goto out;
1406 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001407 if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001408 printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n",
1409 ECRYPTFS_TAG_3_PACKET_TYPE);
Michael Halcrow237fead2006-10-04 02:16:22 -07001410 rc = -EINVAL;
1411 goto out;
1412 }
1413 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1414 * at end of function upon failure */
1415 auth_tok_list_item =
Robert P. J. Dayc3762222007-02-10 01:45:03 -08001416 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
Michael Halcrow237fead2006-10-04 02:16:22 -07001417 if (!auth_tok_list_item) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001418 printk(KERN_ERR "Unable to allocate memory\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001419 rc = -ENOMEM;
1420 goto out;
1421 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001422 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001423 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1424 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001425 if (rc) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001426 printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n",
1427 rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07001428 goto out_free;
1429 }
Michael Halcrowc59becf2007-10-16 01:27:56 -07001430 if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001431 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001432 rc = -EINVAL;
1433 goto out_free;
1434 }
1435 (*packet_size) += length_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07001436 if (unlikely((*packet_size) + body_size > max_packet_size)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001437 printk(KERN_ERR "Packet size exceeds max\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001438 rc = -EINVAL;
1439 goto out_free;
1440 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001441 (*new_auth_tok)->session_key.encrypted_key_size =
Michael Halcrowc59becf2007-10-16 01:27:56 -07001442 (body_size - (ECRYPTFS_SALT_SIZE + 5));
Ramon de Carvalho Vallef151cd22009-07-28 13:58:22 -05001443 if ((*new_auth_tok)->session_key.encrypted_key_size
1444 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
1445 printk(KERN_WARNING "Tag 3 packet contains key larger "
1446 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n");
1447 rc = -EINVAL;
1448 goto out_free;
1449 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001450 if (unlikely(data[(*packet_size)++] != 0x04)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001451 printk(KERN_WARNING "Unknown version number [%d]\n",
1452 data[(*packet_size) - 1]);
Michael Halcrow237fead2006-10-04 02:16:22 -07001453 rc = -EINVAL;
1454 goto out_free;
1455 }
Tyler Hicksb0105ea2009-08-11 00:36:32 -05001456 rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher,
1457 (u16)data[(*packet_size)]);
1458 if (rc)
1459 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07001460 /* A little extra work to differentiate among the AES key
1461 * sizes; see RFC2440 */
1462 switch(data[(*packet_size)++]) {
1463 case RFC2440_CIPHER_AES_192:
1464 crypt_stat->key_size = 24;
1465 break;
1466 default:
1467 crypt_stat->key_size =
1468 (*new_auth_tok)->session_key.encrypted_key_size;
1469 }
Tyler Hicksb0105ea2009-08-11 00:36:32 -05001470 rc = ecryptfs_init_crypt_ctx(crypt_stat);
1471 if (rc)
1472 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07001473 if (unlikely(data[(*packet_size)++] != 0x03)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001474 printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001475 rc = -ENOSYS;
1476 goto out_free;
1477 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001478 /* TODO: finish the hash mapping */
Michael Halcrow237fead2006-10-04 02:16:22 -07001479 switch (data[(*packet_size)++]) {
1480 case 0x01: /* See RFC2440 for these numbers and their mappings */
1481 /* Choose MD5 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001482 memcpy((*new_auth_tok)->token.password.salt,
1483 &data[(*packet_size)], ECRYPTFS_SALT_SIZE);
1484 (*packet_size) += ECRYPTFS_SALT_SIZE;
Michael Halcrow237fead2006-10-04 02:16:22 -07001485 /* This conversion was taken straight from RFC2440 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001486 (*new_auth_tok)->token.password.hash_iterations =
1487 ((u32) 16 + (data[(*packet_size)] & 15))
1488 << ((data[(*packet_size)] >> 4) + 6);
1489 (*packet_size)++;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001490 /* Friendly reminder:
1491 * (*new_auth_tok)->session_key.encrypted_key_size =
1492 * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */
Michael Halcrow237fead2006-10-04 02:16:22 -07001493 memcpy((*new_auth_tok)->session_key.encrypted_key,
1494 &data[(*packet_size)],
1495 (*new_auth_tok)->session_key.encrypted_key_size);
1496 (*packet_size) +=
1497 (*new_auth_tok)->session_key.encrypted_key_size;
1498 (*new_auth_tok)->session_key.flags &=
1499 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1500 (*new_auth_tok)->session_key.flags |=
1501 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001502 (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001503 break;
1504 default:
1505 ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: "
1506 "[%d]\n", data[(*packet_size) - 1]);
1507 rc = -ENOSYS;
1508 goto out_free;
1509 }
1510 (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD;
1511 /* TODO: Parametarize; we might actually want userspace to
1512 * decrypt the session key. */
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001513 (*new_auth_tok)->session_key.flags &=
1514 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1515 (*new_auth_tok)->session_key.flags &=
1516 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
Michael Halcrow237fead2006-10-04 02:16:22 -07001517 list_add(&auth_tok_list_item->list, auth_tok_list);
1518 goto out;
1519out_free:
1520 (*new_auth_tok) = NULL;
1521 memset(auth_tok_list_item, 0,
1522 sizeof(struct ecryptfs_auth_tok_list_item));
1523 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1524 auth_tok_list_item);
1525out:
1526 if (rc)
1527 (*packet_size) = 0;
1528 return rc;
1529}
1530
1531/**
1532 * parse_tag_11_packet
1533 * @data: The raw bytes of the packet
1534 * @contents: This function writes the data contents of the literal
1535 * packet into this memory location
1536 * @max_contents_bytes: The maximum number of bytes that this function
1537 * is allowed to write into contents
1538 * @tag_11_contents_size: This function writes the size of the parsed
1539 * contents into this memory location; zero on
1540 * error
1541 * @packet_size: This function writes the size of the parsed packet
1542 * into this memory location; zero on error
1543 * @max_packet_size: maximum number of bytes to parse
1544 *
1545 * Returns zero on success; non-zero on error.
1546 */
1547static int
1548parse_tag_11_packet(unsigned char *data, unsigned char *contents,
1549 size_t max_contents_bytes, size_t *tag_11_contents_size,
1550 size_t *packet_size, size_t max_packet_size)
1551{
Michael Halcrow237fead2006-10-04 02:16:22 -07001552 size_t body_size;
1553 size_t length_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001554 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001555
1556 (*packet_size) = 0;
1557 (*tag_11_contents_size) = 0;
Michael Halcrowf6481042007-10-16 01:27:57 -07001558 /* This format is inspired by OpenPGP; see RFC 2440
1559 * packet tag 11
1560 *
1561 * Tag 11 identifier (1 byte)
1562 * Max Tag 11 packet size (max 3 bytes)
1563 * Binary format specifier (1 byte)
1564 * Filename length (1 byte)
1565 * Filename ("_CONSOLE") (8 bytes)
1566 * Modification date (4 bytes)
1567 * Literal data (arbitrary)
1568 *
1569 * We need at least 16 bytes of data for the packet to even be
1570 * valid.
Michael Halcrow237fead2006-10-04 02:16:22 -07001571 */
Michael Halcrowf6481042007-10-16 01:27:57 -07001572 if (max_packet_size < 16) {
1573 printk(KERN_ERR "Maximum packet size too small\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001574 rc = -EINVAL;
1575 goto out;
1576 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001577 if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001578 printk(KERN_WARNING "Invalid tag 11 packet format\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001579 rc = -EINVAL;
1580 goto out;
1581 }
Michael Halcrowf66e8832008-04-29 00:59:51 -07001582 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1583 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001584 if (rc) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001585 printk(KERN_WARNING "Invalid tag 11 packet format\n");
1586 goto out;
1587 }
1588 if (body_size < 14) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001589 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrowf6481042007-10-16 01:27:57 -07001590 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07001591 goto out;
1592 }
1593 (*packet_size) += length_size;
Michael Halcrowf6481042007-10-16 01:27:57 -07001594 (*tag_11_contents_size) = (body_size - 14);
Michael Halcrow237fead2006-10-04 02:16:22 -07001595 if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001596 printk(KERN_ERR "Packet size exceeds max\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001597 rc = -EINVAL;
1598 goto out;
1599 }
Tyler Hicks6352a292009-07-28 13:57:01 -05001600 if (unlikely((*tag_11_contents_size) > max_contents_bytes)) {
1601 printk(KERN_ERR "Literal data section in tag 11 packet exceeds "
1602 "expected size\n");
1603 rc = -EINVAL;
1604 goto out;
1605 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001606 if (data[(*packet_size)++] != 0x62) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001607 printk(KERN_WARNING "Unrecognizable packet\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001608 rc = -EINVAL;
1609 goto out;
1610 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001611 if (data[(*packet_size)++] != 0x08) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001612 printk(KERN_WARNING "Unrecognizable packet\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001613 rc = -EINVAL;
1614 goto out;
1615 }
Michael Halcrowf6481042007-10-16 01:27:57 -07001616 (*packet_size) += 12; /* Ignore filename and modification date */
Michael Halcrow237fead2006-10-04 02:16:22 -07001617 memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size));
1618 (*packet_size) += (*tag_11_contents_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001619out:
1620 if (rc) {
1621 (*packet_size) = 0;
1622 (*tag_11_contents_size) = 0;
1623 }
1624 return rc;
1625}
1626
Michael Halcrowf4aad162007-10-16 01:27:53 -07001627int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
1628 struct ecryptfs_auth_tok **auth_tok,
1629 char *sig)
1630{
1631 int rc = 0;
1632
1633 (*auth_tok_key) = request_key(&key_type_user, sig, NULL);
1634 if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
Roberto Sassu1252cc32011-06-27 13:45:45 +02001635 (*auth_tok_key) = ecryptfs_get_encrypted_key(sig);
1636 if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
1637 printk(KERN_ERR "Could not find key with description: [%s]\n",
1638 sig);
1639 rc = process_request_key_err(PTR_ERR(*auth_tok_key));
1640 (*auth_tok_key) = NULL;
1641 goto out;
1642 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001643 }
Roberto Sassub5695d02011-03-21 16:00:55 +01001644 down_write(&(*auth_tok_key)->sem);
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +01001645 rc = ecryptfs_verify_auth_tok_from_key(*auth_tok_key, auth_tok);
Roberto Sassuaee683b2010-10-06 18:31:06 +02001646 if (rc) {
Roberto Sassub5695d02011-03-21 16:00:55 +01001647 up_write(&(*auth_tok_key)->sem);
Roberto Sassuaee683b2010-10-06 18:31:06 +02001648 key_put(*auth_tok_key);
1649 (*auth_tok_key) = NULL;
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +01001650 goto out;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001651 }
1652out:
1653 return rc;
1654}
1655
1656/**
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001657 * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok.
1658 * @auth_tok: The passphrase authentication token to use to encrypt the FEK
1659 * @crypt_stat: The cryptographic context
Michael Halcrow237fead2006-10-04 02:16:22 -07001660 *
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001661 * Returns zero on success; non-zero error otherwise
Michael Halcrow237fead2006-10-04 02:16:22 -07001662 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07001663static int
1664decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1665 struct ecryptfs_crypt_stat *crypt_stat)
Michael Halcrow237fead2006-10-04 02:16:22 -07001666{
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001667 struct scatterlist dst_sg[2];
1668 struct scatterlist src_sg[2];
Michael Halcrowdd8e2902007-10-16 01:28:03 -07001669 struct mutex *tfm_mutex;
Michael Halcrow8bba0662006-10-30 22:07:18 -08001670 struct blkcipher_desc desc = {
1671 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
1672 };
1673 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001674
Michael Halcrowf4aad162007-10-16 01:27:53 -07001675 if (unlikely(ecryptfs_verbosity > 0)) {
1676 ecryptfs_printk(
1677 KERN_DEBUG, "Session key encryption key (size [%d]):\n",
1678 auth_tok->token.password.session_key_encryption_key_bytes);
1679 ecryptfs_dump_hex(
1680 auth_tok->token.password.session_key_encryption_key,
1681 auth_tok->token.password.session_key_encryption_key_bytes);
Michael Halcrow237fead2006-10-04 02:16:22 -07001682 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001683 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
1684 crypt_stat->cipher);
1685 if (unlikely(rc)) {
1686 printk(KERN_ERR "Internal error whilst attempting to get "
1687 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1688 crypt_stat->cipher, rc);
1689 goto out;
1690 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07001691 rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
1692 auth_tok->session_key.encrypted_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001693 src_sg, 2);
1694 if (rc < 1 || rc > 2) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001695 printk(KERN_ERR "Internal error whilst attempting to convert "
1696 "auth_tok->session_key.encrypted_key to scatterlist; "
1697 "expected rc = 1; got rc = [%d]. "
1698 "auth_tok->session_key.encrypted_key_size = [%d]\n", rc,
1699 auth_tok->session_key.encrypted_key_size);
1700 goto out;
1701 }
1702 auth_tok->session_key.decrypted_key_size =
1703 auth_tok->session_key.encrypted_key_size;
Michael Halcrow5dda6992007-10-16 01:28:06 -07001704 rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key,
1705 auth_tok->session_key.decrypted_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001706 dst_sg, 2);
1707 if (rc < 1 || rc > 2) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001708 printk(KERN_ERR "Internal error whilst attempting to convert "
1709 "auth_tok->session_key.decrypted_key to scatterlist; "
1710 "expected rc = 1; got rc = [%d]\n", rc);
1711 goto out;
1712 }
1713 mutex_lock(tfm_mutex);
1714 rc = crypto_blkcipher_setkey(
1715 desc.tfm, auth_tok->token.password.session_key_encryption_key,
1716 crypt_stat->key_size);
1717 if (unlikely(rc < 0)) {
1718 mutex_unlock(tfm_mutex);
Michael Halcrowe5d9cbd2006-10-30 22:07:16 -08001719 printk(KERN_ERR "Error setting key for crypto context\n");
1720 rc = -EINVAL;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001721 goto out;
Michael Halcrowe5d9cbd2006-10-30 22:07:16 -08001722 }
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001723 rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg,
Michael Halcrow8bba0662006-10-30 22:07:18 -08001724 auth_tok->session_key.encrypted_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001725 mutex_unlock(tfm_mutex);
1726 if (unlikely(rc)) {
Michael Halcrow8bba0662006-10-30 22:07:18 -08001727 printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001728 goto out;
Michael Halcrow8bba0662006-10-30 22:07:18 -08001729 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001730 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1731 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1732 auth_tok->session_key.decrypted_key_size);
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001733 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001734 if (unlikely(ecryptfs_verbosity > 0)) {
Tyler Hicksf24b3882010-11-15 17:36:38 -06001735 ecryptfs_printk(KERN_DEBUG, "FEK of size [%zd]:\n",
Michael Halcrowf4aad162007-10-16 01:27:53 -07001736 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001737 ecryptfs_dump_hex(crypt_stat->key,
1738 crypt_stat->key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001739 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001740out:
1741 return rc;
1742}
1743
1744/**
1745 * ecryptfs_parse_packet_set
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001746 * @crypt_stat: The cryptographic context
1747 * @src: Virtual address of region of memory containing the packets
1748 * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set
Michael Halcrow237fead2006-10-04 02:16:22 -07001749 *
1750 * Get crypt_stat to have the file's session key if the requisite key
1751 * is available to decrypt the session key.
1752 *
1753 * Returns Zero if a valid authentication token was retrieved and
1754 * processed; negative value for file not encrypted or for error
1755 * conditions.
1756 */
1757int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
1758 unsigned char *src,
1759 struct dentry *ecryptfs_dentry)
1760{
1761 size_t i = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001762 size_t found_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07001763 size_t next_packet_is_auth_tok_packet;
Michael Halcrow237fead2006-10-04 02:16:22 -07001764 struct list_head auth_tok_list;
Michael Halcrowdd8e2902007-10-16 01:28:03 -07001765 struct ecryptfs_auth_tok *matching_auth_tok;
1766 struct ecryptfs_auth_tok *candidate_auth_tok;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001767 char *candidate_auth_tok_sig;
Michael Halcrow237fead2006-10-04 02:16:22 -07001768 size_t packet_size;
1769 struct ecryptfs_auth_tok *new_auth_tok;
1770 unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE];
Michael Halcrowf4aad162007-10-16 01:27:53 -07001771 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
Michael Halcrow237fead2006-10-04 02:16:22 -07001772 size_t tag_11_contents_size;
1773 size_t tag_11_packet_size;
Roberto Sassuaee683b2010-10-06 18:31:06 +02001774 struct key *auth_tok_key = NULL;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001775 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001776
1777 INIT_LIST_HEAD(&auth_tok_list);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001778 /* Parse the header to find as many packets as we can; these will be
Michael Halcrow237fead2006-10-04 02:16:22 -07001779 * added the our &auth_tok_list */
1780 next_packet_is_auth_tok_packet = 1;
1781 while (next_packet_is_auth_tok_packet) {
1782 size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i);
1783
1784 switch (src[i]) {
1785 case ECRYPTFS_TAG_3_PACKET_TYPE:
1786 rc = parse_tag_3_packet(crypt_stat,
1787 (unsigned char *)&src[i],
1788 &auth_tok_list, &new_auth_tok,
1789 &packet_size, max_packet_size);
1790 if (rc) {
1791 ecryptfs_printk(KERN_ERR, "Error parsing "
1792 "tag 3 packet\n");
1793 rc = -EIO;
1794 goto out_wipe_list;
1795 }
1796 i += packet_size;
1797 rc = parse_tag_11_packet((unsigned char *)&src[i],
1798 sig_tmp_space,
1799 ECRYPTFS_SIG_SIZE,
1800 &tag_11_contents_size,
1801 &tag_11_packet_size,
1802 max_packet_size);
1803 if (rc) {
1804 ecryptfs_printk(KERN_ERR, "No valid "
1805 "(ecryptfs-specific) literal "
1806 "packet containing "
1807 "authentication token "
1808 "signature found after "
1809 "tag 3 packet\n");
1810 rc = -EIO;
1811 goto out_wipe_list;
1812 }
1813 i += tag_11_packet_size;
1814 if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) {
1815 ecryptfs_printk(KERN_ERR, "Expected "
1816 "signature of size [%d]; "
Tyler Hicksf24b3882010-11-15 17:36:38 -06001817 "read size [%zd]\n",
Michael Halcrow237fead2006-10-04 02:16:22 -07001818 ECRYPTFS_SIG_SIZE,
1819 tag_11_contents_size);
1820 rc = -EIO;
1821 goto out_wipe_list;
1822 }
1823 ecryptfs_to_hex(new_auth_tok->token.password.signature,
1824 sig_tmp_space, tag_11_contents_size);
1825 new_auth_tok->token.password.signature[
1826 ECRYPTFS_PASSWORD_SIG_SIZE] = '\0';
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001827 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
Michael Halcrow237fead2006-10-04 02:16:22 -07001828 break;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001829 case ECRYPTFS_TAG_1_PACKET_TYPE:
1830 rc = parse_tag_1_packet(crypt_stat,
1831 (unsigned char *)&src[i],
1832 &auth_tok_list, &new_auth_tok,
1833 &packet_size, max_packet_size);
1834 if (rc) {
1835 ecryptfs_printk(KERN_ERR, "Error parsing "
1836 "tag 1 packet\n");
1837 rc = -EIO;
1838 goto out_wipe_list;
1839 }
1840 i += packet_size;
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001841 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001842 break;
Michael Halcrow237fead2006-10-04 02:16:22 -07001843 case ECRYPTFS_TAG_11_PACKET_TYPE:
1844 ecryptfs_printk(KERN_WARNING, "Invalid packet set "
1845 "(Tag 11 not allowed by itself)\n");
1846 rc = -EIO;
1847 goto out_wipe_list;
Michael Halcrow237fead2006-10-04 02:16:22 -07001848 default:
Tyler Hicksf24b3882010-11-15 17:36:38 -06001849 ecryptfs_printk(KERN_DEBUG, "No packet at offset [%zd] "
1850 "of the file header; hex value of "
Michael Halcrow237fead2006-10-04 02:16:22 -07001851 "character is [0x%.2x]\n", i, src[i]);
1852 next_packet_is_auth_tok_packet = 0;
1853 }
1854 }
1855 if (list_empty(&auth_tok_list)) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001856 printk(KERN_ERR "The lower file appears to be a non-encrypted "
1857 "eCryptfs file; this is not supported in this version "
1858 "of the eCryptfs kernel module\n");
1859 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07001860 goto out;
1861 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001862 /* auth_tok_list contains the set of authentication tokens
1863 * parsed from the metadata. We need to find a matching
1864 * authentication token that has the secret component(s)
1865 * necessary to decrypt the EFEK in the auth_tok parsed from
1866 * the metadata. There may be several potential matches, but
1867 * just one will be sufficient to decrypt to get the FEK. */
1868find_next_matching_auth_tok:
1869 found_auth_tok = 0;
1870 list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001871 candidate_auth_tok = &auth_tok_list_item->auth_tok;
1872 if (unlikely(ecryptfs_verbosity > 0)) {
1873 ecryptfs_printk(KERN_DEBUG,
1874 "Considering cadidate auth tok:\n");
1875 ecryptfs_dump_auth_tok(candidate_auth_tok);
1876 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07001877 rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig,
1878 candidate_auth_tok);
1879 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001880 printk(KERN_ERR
1881 "Unrecognized candidate auth tok type: [%d]\n",
1882 candidate_auth_tok->token_type);
1883 rc = -EINVAL;
1884 goto out_wipe_list;
1885 }
Roberto Sassu39fac852010-10-06 18:31:15 +02001886 rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key,
Roberto Sassuaee683b2010-10-06 18:31:06 +02001887 &matching_auth_tok,
Michael Halcrow9c79f342009-01-06 14:41:57 -08001888 crypt_stat->mount_crypt_stat,
Michael Halcrow5dda6992007-10-16 01:28:06 -07001889 candidate_auth_tok_sig);
Roberto Sassu39fac852010-10-06 18:31:15 +02001890 if (!rc) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001891 found_auth_tok = 1;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001892 goto found_matching_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07001893 }
1894 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001895 if (!found_auth_tok) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001896 ecryptfs_printk(KERN_ERR, "Could not find a usable "
1897 "authentication token\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001898 rc = -EIO;
1899 goto out_wipe_list;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001900 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001901found_matching_auth_tok:
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001902 if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
Michael Halcrowdddfa462007-02-12 00:53:44 -08001903 memcpy(&(candidate_auth_tok->token.private_key),
Michael Halcrowf4aad162007-10-16 01:27:53 -07001904 &(matching_auth_tok->token.private_key),
Michael Halcrowdddfa462007-02-12 00:53:44 -08001905 sizeof(struct ecryptfs_private_key));
Tyler Hicksb2987a52011-07-26 19:47:08 -05001906 up_write(&(auth_tok_key->sem));
1907 key_put(auth_tok_key);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001908 rc = decrypt_pki_encrypted_session_key(candidate_auth_tok,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001909 crypt_stat);
1910 } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001911 memcpy(&(candidate_auth_tok->token.password),
Michael Halcrowf4aad162007-10-16 01:27:53 -07001912 &(matching_auth_tok->token.password),
Michael Halcrow237fead2006-10-04 02:16:22 -07001913 sizeof(struct ecryptfs_password));
Tyler Hicksb2987a52011-07-26 19:47:08 -05001914 up_write(&(auth_tok_key->sem));
1915 key_put(auth_tok_key);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001916 rc = decrypt_passphrase_encrypted_session_key(
1917 candidate_auth_tok, crypt_stat);
Tyler Hicksb2987a52011-07-26 19:47:08 -05001918 } else {
1919 up_write(&(auth_tok_key->sem));
1920 key_put(auth_tok_key);
1921 rc = -EINVAL;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001922 }
1923 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001924 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1925
1926 ecryptfs_printk(KERN_WARNING, "Error decrypting the "
1927 "session key for authentication token with sig "
1928 "[%.*s]; rc = [%d]. Removing auth tok "
1929 "candidate from the list and searching for "
Joe Perches888d57b2010-11-10 15:46:16 -08001930 "the next match.\n", ECRYPTFS_SIG_SIZE_HEX,
1931 candidate_auth_tok_sig, rc);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001932 list_for_each_entry_safe(auth_tok_list_item,
1933 auth_tok_list_item_tmp,
1934 &auth_tok_list, list) {
1935 if (candidate_auth_tok
1936 == &auth_tok_list_item->auth_tok) {
1937 list_del(&auth_tok_list_item->list);
1938 kmem_cache_free(
1939 ecryptfs_auth_tok_list_item_cache,
1940 auth_tok_list_item);
1941 goto find_next_matching_auth_tok;
1942 }
1943 }
1944 BUG();
Michael Halcrowdddfa462007-02-12 00:53:44 -08001945 }
1946 rc = ecryptfs_compute_root_iv(crypt_stat);
1947 if (rc) {
1948 ecryptfs_printk(KERN_ERR, "Error computing "
1949 "the root IV\n");
1950 goto out_wipe_list;
Michael Halcrow237fead2006-10-04 02:16:22 -07001951 }
1952 rc = ecryptfs_init_crypt_ctx(crypt_stat);
1953 if (rc) {
1954 ecryptfs_printk(KERN_ERR, "Error initializing crypto "
1955 "context for cipher [%s]; rc = [%d]\n",
1956 crypt_stat->cipher, rc);
1957 }
1958out_wipe_list:
1959 wipe_auth_tok_list(&auth_tok_list);
1960out:
1961 return rc;
1962}
Michael Halcrowf4aad162007-10-16 01:27:53 -07001963
Michael Halcrowdddfa462007-02-12 00:53:44 -08001964static int
Tyler Hicksb2987a52011-07-26 19:47:08 -05001965pki_encrypt_session_key(struct key *auth_tok_key,
1966 struct ecryptfs_auth_tok *auth_tok,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001967 struct ecryptfs_crypt_stat *crypt_stat,
1968 struct ecryptfs_key_record *key_rec)
1969{
1970 struct ecryptfs_msg_ctx *msg_ctx = NULL;
Tyler Hicks624ae522008-10-15 22:02:51 -07001971 char *payload = NULL;
Tyler Hicks99b373f2011-08-05 04:15:19 -05001972 size_t payload_len = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001973 struct ecryptfs_message *msg;
1974 int rc;
1975
1976 rc = write_tag_66_packet(auth_tok->token.private_key.signature,
Michael Halcrow9c79f342009-01-06 14:41:57 -08001977 ecryptfs_code_for_cipher_string(
1978 crypt_stat->cipher,
1979 crypt_stat->key_size),
Tyler Hicks624ae522008-10-15 22:02:51 -07001980 crypt_stat, &payload, &payload_len);
Tyler Hicksb2987a52011-07-26 19:47:08 -05001981 up_write(&(auth_tok_key->sem));
1982 key_put(auth_tok_key);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001983 if (rc) {
1984 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
1985 goto out;
1986 }
Tyler Hicks624ae522008-10-15 22:02:51 -07001987 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001988 if (rc) {
Tyler Hicks624ae522008-10-15 22:02:51 -07001989 ecryptfs_printk(KERN_ERR, "Error sending message to "
Kees Cook290502b2013-02-28 00:39:37 -08001990 "ecryptfsd: %d\n", rc);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001991 goto out;
1992 }
1993 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1994 if (rc) {
1995 ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet "
1996 "from the user space daemon\n");
1997 rc = -EIO;
1998 goto out;
1999 }
2000 rc = parse_tag_67_packet(key_rec, msg);
2001 if (rc)
2002 ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n");
2003 kfree(msg);
2004out:
Tyler Hicks624ae522008-10-15 22:02:51 -07002005 kfree(payload);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002006 return rc;
2007}
2008/**
2009 * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet
2010 * @dest: Buffer into which to write the packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002011 * @remaining_bytes: Maximum number of bytes that can be writtn
Tyler Hicksb2987a52011-07-26 19:47:08 -05002012 * @auth_tok_key: The authentication token key to unlock and put when done with
2013 * @auth_tok
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002014 * @auth_tok: The authentication token used for generating the tag 1 packet
2015 * @crypt_stat: The cryptographic context
2016 * @key_rec: The key record struct for the tag 1 packet
Michael Halcrowdddfa462007-02-12 00:53:44 -08002017 * @packet_size: This function will write the number of bytes that end
2018 * up constituting the packet; set to zero on error
2019 *
2020 * Returns zero on success; non-zero on error.
2021 */
2022static int
Michael Halcrowf4aad162007-10-16 01:27:53 -07002023write_tag_1_packet(char *dest, size_t *remaining_bytes,
Tyler Hicksb2987a52011-07-26 19:47:08 -05002024 struct key *auth_tok_key, struct ecryptfs_auth_tok *auth_tok,
Michael Halcrowdddfa462007-02-12 00:53:44 -08002025 struct ecryptfs_crypt_stat *crypt_stat,
Michael Halcrowdddfa462007-02-12 00:53:44 -08002026 struct ecryptfs_key_record *key_rec, size_t *packet_size)
2027{
2028 size_t i;
2029 size_t encrypted_session_key_valid = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002030 size_t packet_size_length;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002031 size_t max_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002032 int rc = 0;
2033
2034 (*packet_size) = 0;
2035 ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature,
2036 ECRYPTFS_SIG_SIZE);
2037 encrypted_session_key_valid = 0;
2038 for (i = 0; i < crypt_stat->key_size; i++)
2039 encrypted_session_key_valid |=
2040 auth_tok->session_key.encrypted_key[i];
2041 if (encrypted_session_key_valid) {
2042 memcpy(key_rec->enc_key,
2043 auth_tok->session_key.encrypted_key,
2044 auth_tok->session_key.encrypted_key_size);
Tyler Hicksb2987a52011-07-26 19:47:08 -05002045 up_write(&(auth_tok_key->sem));
2046 key_put(auth_tok_key);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002047 goto encrypted_session_key_set;
2048 }
2049 if (auth_tok->session_key.encrypted_key_size == 0)
2050 auth_tok->session_key.encrypted_key_size =
2051 auth_tok->token.private_key.key_size;
Tyler Hicksb2987a52011-07-26 19:47:08 -05002052 rc = pki_encrypt_session_key(auth_tok_key, auth_tok, crypt_stat,
2053 key_rec);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002054 if (rc) {
Michael Halcrowf66e8832008-04-29 00:59:51 -07002055 printk(KERN_ERR "Failed to encrypt session key via a key "
2056 "module; rc = [%d]\n", rc);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002057 goto out;
2058 }
2059 if (ecryptfs_verbosity > 0) {
2060 ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n");
2061 ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size);
2062 }
2063encrypted_session_key_set:
Michael Halcrowf4aad162007-10-16 01:27:53 -07002064 /* This format is inspired by OpenPGP; see RFC 2440
2065 * packet tag 1 */
2066 max_packet_size = (1 /* Tag 1 identifier */
2067 + 3 /* Max Tag 1 packet size */
2068 + 1 /* Version */
2069 + ECRYPTFS_SIG_SIZE /* Key identifier */
2070 + 1 /* Cipher identifier */
2071 + key_rec->enc_key_size); /* Encrypted key size */
2072 if (max_packet_size > (*remaining_bytes)) {
2073 printk(KERN_ERR "Packet length larger than maximum allowable; "
Andrew Morton81acbcd2007-10-16 01:27:59 -07002074 "need up to [%td] bytes, but there are only [%td] "
Michael Halcrowf4aad162007-10-16 01:27:53 -07002075 "available\n", max_packet_size, (*remaining_bytes));
Michael Halcrowdddfa462007-02-12 00:53:44 -08002076 rc = -EINVAL;
2077 goto out;
2078 }
2079 dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -07002080 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
2081 (max_packet_size - 4),
2082 &packet_size_length);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002083 if (rc) {
2084 ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet "
2085 "header; cannot generate packet length\n");
2086 goto out;
2087 }
2088 (*packet_size) += packet_size_length;
2089 dest[(*packet_size)++] = 0x03; /* version 3 */
2090 memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE);
2091 (*packet_size) += ECRYPTFS_SIG_SIZE;
2092 dest[(*packet_size)++] = RFC2440_CIPHER_RSA;
2093 memcpy(&dest[(*packet_size)], key_rec->enc_key,
2094 key_rec->enc_key_size);
2095 (*packet_size) += key_rec->enc_key_size;
2096out:
2097 if (rc)
2098 (*packet_size) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002099 else
2100 (*remaining_bytes) -= (*packet_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002101 return rc;
2102}
Michael Halcrow237fead2006-10-04 02:16:22 -07002103
2104/**
2105 * write_tag_11_packet
2106 * @dest: Target into which Tag 11 packet is to be written
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002107 * @remaining_bytes: Maximum packet length
Michael Halcrow237fead2006-10-04 02:16:22 -07002108 * @contents: Byte array of contents to copy in
2109 * @contents_length: Number of bytes in contents
2110 * @packet_length: Length of the Tag 11 packet written; zero on error
2111 *
2112 * Returns zero on success; non-zero on error.
2113 */
2114static int
Andrew Morton81acbcd2007-10-16 01:27:59 -07002115write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents,
Michael Halcrow146a4602007-10-16 01:27:58 -07002116 size_t contents_length, size_t *packet_length)
Michael Halcrow237fead2006-10-04 02:16:22 -07002117{
Michael Halcrow237fead2006-10-04 02:16:22 -07002118 size_t packet_size_length;
Michael Halcrow146a4602007-10-16 01:27:58 -07002119 size_t max_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002120 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002121
2122 (*packet_length) = 0;
Michael Halcrow146a4602007-10-16 01:27:58 -07002123 /* This format is inspired by OpenPGP; see RFC 2440
2124 * packet tag 11 */
2125 max_packet_size = (1 /* Tag 11 identifier */
2126 + 3 /* Max Tag 11 packet size */
2127 + 1 /* Binary format specifier */
2128 + 1 /* Filename length */
2129 + 8 /* Filename ("_CONSOLE") */
2130 + 4 /* Modification date */
2131 + contents_length); /* Literal data */
2132 if (max_packet_size > (*remaining_bytes)) {
2133 printk(KERN_ERR "Packet length larger than maximum allowable; "
Andrew Morton81acbcd2007-10-16 01:27:59 -07002134 "need up to [%td] bytes, but there are only [%td] "
Michael Halcrow146a4602007-10-16 01:27:58 -07002135 "available\n", max_packet_size, (*remaining_bytes));
Michael Halcrow237fead2006-10-04 02:16:22 -07002136 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07002137 goto out;
2138 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002139 dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -07002140 rc = ecryptfs_write_packet_length(&dest[(*packet_length)],
2141 (max_packet_size - 4),
2142 &packet_size_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002143 if (rc) {
Michael Halcrow146a4602007-10-16 01:27:58 -07002144 printk(KERN_ERR "Error generating tag 11 packet header; cannot "
2145 "generate packet length. rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002146 goto out;
2147 }
2148 (*packet_length) += packet_size_length;
Michael Halcrow146a4602007-10-16 01:27:58 -07002149 dest[(*packet_length)++] = 0x62; /* binary data format specifier */
Michael Halcrow237fead2006-10-04 02:16:22 -07002150 dest[(*packet_length)++] = 8;
2151 memcpy(&dest[(*packet_length)], "_CONSOLE", 8);
2152 (*packet_length) += 8;
Michael Halcrow237fead2006-10-04 02:16:22 -07002153 memset(&dest[(*packet_length)], 0x00, 4);
2154 (*packet_length) += 4;
Michael Halcrow237fead2006-10-04 02:16:22 -07002155 memcpy(&dest[(*packet_length)], contents, contents_length);
2156 (*packet_length) += contents_length;
2157 out:
2158 if (rc)
2159 (*packet_length) = 0;
Michael Halcrow146a4602007-10-16 01:27:58 -07002160 else
2161 (*remaining_bytes) -= (*packet_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002162 return rc;
2163}
2164
2165/**
2166 * write_tag_3_packet
2167 * @dest: Buffer into which to write the packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002168 * @remaining_bytes: Maximum number of bytes that can be written
Michael Halcrow237fead2006-10-04 02:16:22 -07002169 * @auth_tok: Authentication token
2170 * @crypt_stat: The cryptographic context
2171 * @key_rec: encrypted key
2172 * @packet_size: This function will write the number of bytes that end
2173 * up constituting the packet; set to zero on error
2174 *
2175 * Returns zero on success; non-zero on error.
2176 */
2177static int
Michael Halcrowf4aad162007-10-16 01:27:53 -07002178write_tag_3_packet(char *dest, size_t *remaining_bytes,
2179 struct ecryptfs_auth_tok *auth_tok,
Michael Halcrow237fead2006-10-04 02:16:22 -07002180 struct ecryptfs_crypt_stat *crypt_stat,
2181 struct ecryptfs_key_record *key_rec, size_t *packet_size)
2182{
Michael Halcrow237fead2006-10-04 02:16:22 -07002183 size_t i;
Michael Halcrow237fead2006-10-04 02:16:22 -07002184 size_t encrypted_session_key_valid = 0;
2185 char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002186 struct scatterlist dst_sg[2];
2187 struct scatterlist src_sg[2];
Michael Halcrow237fead2006-10-04 02:16:22 -07002188 struct mutex *tfm_mutex = NULL;
Trevor Highland19e66a62008-02-06 01:38:36 -08002189 u8 cipher_code;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002190 size_t packet_size_length;
2191 size_t max_packet_size;
2192 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2193 crypt_stat->mount_crypt_stat;
Michael Halcrow8bba0662006-10-30 22:07:18 -08002194 struct blkcipher_desc desc = {
2195 .tfm = NULL,
2196 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
2197 };
2198 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002199
2200 (*packet_size) = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002201 ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
Michael Halcrow237fead2006-10-04 02:16:22 -07002202 ECRYPTFS_SIG_SIZE);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002203 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
2204 crypt_stat->cipher);
2205 if (unlikely(rc)) {
2206 printk(KERN_ERR "Internal error whilst attempting to get "
2207 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
2208 crypt_stat->cipher, rc);
2209 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -07002210 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002211 if (mount_crypt_stat->global_default_cipher_key_size == 0) {
2212 struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm);
2213
2214 printk(KERN_WARNING "No key size specified at mount; "
2215 "defaulting to [%d]\n", alg->max_keysize);
2216 mount_crypt_stat->global_default_cipher_key_size =
2217 alg->max_keysize;
2218 }
2219 if (crypt_stat->key_size == 0)
2220 crypt_stat->key_size =
2221 mount_crypt_stat->global_default_cipher_key_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07002222 if (auth_tok->session_key.encrypted_key_size == 0)
2223 auth_tok->session_key.encrypted_key_size =
2224 crypt_stat->key_size;
2225 if (crypt_stat->key_size == 24
2226 && strcmp("aes", crypt_stat->cipher) == 0) {
2227 memset((crypt_stat->key + 24), 0, 8);
2228 auth_tok->session_key.encrypted_key_size = 32;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002229 } else
2230 auth_tok->session_key.encrypted_key_size = crypt_stat->key_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002231 key_rec->enc_key_size =
Michael Halcrow237fead2006-10-04 02:16:22 -07002232 auth_tok->session_key.encrypted_key_size;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002233 encrypted_session_key_valid = 0;
2234 for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++)
2235 encrypted_session_key_valid |=
2236 auth_tok->session_key.encrypted_key[i];
2237 if (encrypted_session_key_valid) {
2238 ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; "
2239 "using auth_tok->session_key.encrypted_key, "
Tyler Hicksf24b3882010-11-15 17:36:38 -06002240 "where key_rec->enc_key_size = [%zd]\n",
Michael Halcrowf4aad162007-10-16 01:27:53 -07002241 key_rec->enc_key_size);
2242 memcpy(key_rec->enc_key,
2243 auth_tok->session_key.encrypted_key,
2244 key_rec->enc_key_size);
2245 goto encrypted_session_key_set;
2246 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08002247 if (auth_tok->token.password.flags &
2248 ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002249 ecryptfs_printk(KERN_DEBUG, "Using previously generated "
2250 "session key encryption key of size [%d]\n",
2251 auth_tok->token.password.
2252 session_key_encryption_key_bytes);
2253 memcpy(session_key_encryption_key,
2254 auth_tok->token.password.session_key_encryption_key,
2255 crypt_stat->key_size);
2256 ecryptfs_printk(KERN_DEBUG,
Jean Delvaredf2e3012011-07-16 18:10:35 +02002257 "Cached session key encryption key:\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07002258 if (ecryptfs_verbosity > 0)
2259 ecryptfs_dump_hex(session_key_encryption_key, 16);
2260 }
2261 if (unlikely(ecryptfs_verbosity > 0)) {
2262 ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n");
2263 ecryptfs_dump_hex(session_key_encryption_key, 16);
2264 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07002265 rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002266 src_sg, 2);
2267 if (rc < 1 || rc > 2) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002268 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
Michael Halcrowf4aad162007-10-16 01:27:53 -07002269 "for crypt_stat session key; expected rc = 1; "
Tyler Hicksf24b3882010-11-15 17:36:38 -06002270 "got rc = [%d]. key_rec->enc_key_size = [%zd]\n",
Michael Halcrowf4aad162007-10-16 01:27:53 -07002271 rc, key_rec->enc_key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002272 rc = -ENOMEM;
2273 goto out;
2274 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07002275 rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002276 dst_sg, 2);
2277 if (rc < 1 || rc > 2) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002278 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
Michael Halcrowf4aad162007-10-16 01:27:53 -07002279 "for crypt_stat encrypted session key; "
2280 "expected rc = 1; got rc = [%d]. "
Tyler Hicksf24b3882010-11-15 17:36:38 -06002281 "key_rec->enc_key_size = [%zd]\n", rc,
Michael Halcrowf4aad162007-10-16 01:27:53 -07002282 key_rec->enc_key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002283 rc = -ENOMEM;
2284 goto out;
2285 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002286 mutex_lock(tfm_mutex);
Michael Halcrow8bba0662006-10-30 22:07:18 -08002287 rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key,
2288 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002289 if (rc < 0) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002290 mutex_unlock(tfm_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -07002291 ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
Michael Halcrow8bba0662006-10-30 22:07:18 -08002292 "context; rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002293 goto out;
2294 }
2295 rc = 0;
Tyler Hicksf24b3882010-11-15 17:36:38 -06002296 ecryptfs_printk(KERN_DEBUG, "Encrypting [%zd] bytes of the key\n",
Michael Halcrow237fead2006-10-04 02:16:22 -07002297 crypt_stat->key_size);
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002298 rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg,
Michael Halcrow8bba0662006-10-30 22:07:18 -08002299 (*key_rec).enc_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002300 mutex_unlock(tfm_mutex);
Michael Halcrow8bba0662006-10-30 22:07:18 -08002301 if (rc) {
2302 printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc);
2303 goto out;
2304 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002305 ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
Michael Halcrowf4aad162007-10-16 01:27:53 -07002306 if (ecryptfs_verbosity > 0) {
Tyler Hicksf24b3882010-11-15 17:36:38 -06002307 ecryptfs_printk(KERN_DEBUG, "EFEK of size [%zd]:\n",
Michael Halcrowf4aad162007-10-16 01:27:53 -07002308 key_rec->enc_key_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002309 ecryptfs_dump_hex(key_rec->enc_key,
2310 key_rec->enc_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002311 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002312encrypted_session_key_set:
Michael Halcrow237fead2006-10-04 02:16:22 -07002313 /* This format is inspired by OpenPGP; see RFC 2440
2314 * packet tag 3 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002315 max_packet_size = (1 /* Tag 3 identifier */
2316 + 3 /* Max Tag 3 packet size */
2317 + 1 /* Version */
2318 + 1 /* Cipher code */
2319 + 1 /* S2K specifier */
2320 + 1 /* Hash identifier */
2321 + ECRYPTFS_SALT_SIZE /* Salt */
2322 + 1 /* Hash iterations */
2323 + key_rec->enc_key_size); /* Encrypted key size */
2324 if (max_packet_size > (*remaining_bytes)) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07002325 printk(KERN_ERR "Packet too large; need up to [%td] bytes, but "
2326 "there are only [%td] available\n", max_packet_size,
Michael Halcrowf4aad162007-10-16 01:27:53 -07002327 (*remaining_bytes));
2328 rc = -EINVAL;
2329 goto out;
2330 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002331 dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002332 /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3)
2333 * to get the number of octets in the actual Tag 3 packet */
Michael Halcrowf66e8832008-04-29 00:59:51 -07002334 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
2335 (max_packet_size - 4),
2336 &packet_size_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002337 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002338 printk(KERN_ERR "Error generating tag 3 packet header; cannot "
2339 "generate packet length. rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002340 goto out;
2341 }
2342 (*packet_size) += packet_size_length;
2343 dest[(*packet_size)++] = 0x04; /* version 4 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002344 /* TODO: Break from RFC2440 so that arbitrary ciphers can be
2345 * specified with strings */
Michael Halcrow9c79f342009-01-06 14:41:57 -08002346 cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher,
2347 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002348 if (cipher_code == 0) {
2349 ecryptfs_printk(KERN_WARNING, "Unable to generate code for "
2350 "cipher [%s]\n", crypt_stat->cipher);
2351 rc = -EINVAL;
2352 goto out;
2353 }
2354 dest[(*packet_size)++] = cipher_code;
2355 dest[(*packet_size)++] = 0x03; /* S2K */
2356 dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */
2357 memcpy(&dest[(*packet_size)], auth_tok->token.password.salt,
2358 ECRYPTFS_SALT_SIZE);
2359 (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */
2360 dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */
Michael Halcrowdddfa462007-02-12 00:53:44 -08002361 memcpy(&dest[(*packet_size)], key_rec->enc_key,
2362 key_rec->enc_key_size);
2363 (*packet_size) += key_rec->enc_key_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07002364out:
Michael Halcrow237fead2006-10-04 02:16:22 -07002365 if (rc)
2366 (*packet_size) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002367 else
2368 (*remaining_bytes) -= (*packet_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002369 return rc;
2370}
2371
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002372struct kmem_cache *ecryptfs_key_record_cache;
2373
Michael Halcrow237fead2006-10-04 02:16:22 -07002374/**
2375 * ecryptfs_generate_key_packet_set
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002376 * @dest_base: Virtual address from which to write the key record set
Michael Halcrow237fead2006-10-04 02:16:22 -07002377 * @crypt_stat: The cryptographic context from which the
2378 * authentication tokens will be retrieved
2379 * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat
2380 * for the global parameters
2381 * @len: The amount written
2382 * @max: The maximum amount of data allowed to be written
2383 *
2384 * Generates a key packet set and writes it to the virtual address
2385 * passed in.
2386 *
2387 * Returns zero on success; non-zero on error.
2388 */
2389int
2390ecryptfs_generate_key_packet_set(char *dest_base,
2391 struct ecryptfs_crypt_stat *crypt_stat,
2392 struct dentry *ecryptfs_dentry, size_t *len,
2393 size_t max)
2394{
Michael Halcrow237fead2006-10-04 02:16:22 -07002395 struct ecryptfs_auth_tok *auth_tok;
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +01002396 struct key *auth_tok_key = NULL;
Michael Halcrow237fead2006-10-04 02:16:22 -07002397 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2398 &ecryptfs_superblock_to_private(
2399 ecryptfs_dentry->d_sb)->mount_crypt_stat;
2400 size_t written;
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002401 struct ecryptfs_key_record *key_rec;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002402 struct ecryptfs_key_sig *key_sig;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002403 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002404
2405 (*len) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002406 mutex_lock(&crypt_stat->keysig_list_mutex);
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002407 key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL);
2408 if (!key_rec) {
2409 rc = -ENOMEM;
2410 goto out;
2411 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002412 list_for_each_entry(key_sig, &crypt_stat->keysig_list,
2413 crypt_stat_list) {
2414 memset(key_rec, 0, sizeof(*key_rec));
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +01002415 rc = ecryptfs_find_global_auth_tok_for_sig(&auth_tok_key,
2416 &auth_tok,
Michael Halcrowf4aad162007-10-16 01:27:53 -07002417 mount_crypt_stat,
2418 key_sig->keysig);
2419 if (rc) {
Roberto Sassu0e1fc5e2011-03-21 16:00:53 +01002420 printk(KERN_WARNING "Unable to retrieve auth tok with "
2421 "sig = [%s]\n", key_sig->keysig);
2422 rc = process_find_global_auth_tok_for_sig_err(rc);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002423 goto out_free;
2424 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002425 if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
2426 rc = write_tag_3_packet((dest_base + (*len)),
Michael Halcrowf4aad162007-10-16 01:27:53 -07002427 &max, auth_tok,
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002428 crypt_stat, key_rec,
Michael Halcrow237fead2006-10-04 02:16:22 -07002429 &written);
Tyler Hicksb2987a52011-07-26 19:47:08 -05002430 up_write(&(auth_tok_key->sem));
2431 key_put(auth_tok_key);
Michael Halcrow237fead2006-10-04 02:16:22 -07002432 if (rc) {
2433 ecryptfs_printk(KERN_WARNING, "Error "
2434 "writing tag 3 packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002435 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002436 }
2437 (*len) += written;
2438 /* Write auth tok signature packet */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002439 rc = write_tag_11_packet((dest_base + (*len)), &max,
2440 key_rec->sig,
2441 ECRYPTFS_SIG_SIZE, &written);
Michael Halcrow237fead2006-10-04 02:16:22 -07002442 if (rc) {
2443 ecryptfs_printk(KERN_ERR, "Error writing "
2444 "auth tok signature packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002445 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002446 }
2447 (*len) += written;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002448 } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
Tyler Hicksb2987a52011-07-26 19:47:08 -05002449 rc = write_tag_1_packet(dest_base + (*len), &max,
2450 auth_tok_key, auth_tok,
Michael Halcrowf4aad162007-10-16 01:27:53 -07002451 crypt_stat, key_rec, &written);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002452 if (rc) {
2453 ecryptfs_printk(KERN_WARNING, "Error "
2454 "writing tag 1 packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002455 goto out_free;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002456 }
2457 (*len) += written;
Michael Halcrow237fead2006-10-04 02:16:22 -07002458 } else {
Tyler Hicksb2987a52011-07-26 19:47:08 -05002459 up_write(&(auth_tok_key->sem));
2460 key_put(auth_tok_key);
Michael Halcrow237fead2006-10-04 02:16:22 -07002461 ecryptfs_printk(KERN_WARNING, "Unsupported "
2462 "authentication token type\n");
2463 rc = -EINVAL;
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002464 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002465 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002466 }
2467 if (likely(max > 0)) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002468 dest_base[(*len)] = 0x00;
2469 } else {
2470 ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n");
2471 rc = -EIO;
2472 }
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002473out_free:
2474 kmem_cache_free(ecryptfs_key_record_cache, key_rec);
Michael Halcrow237fead2006-10-04 02:16:22 -07002475out:
2476 if (rc)
2477 (*len) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002478 mutex_unlock(&crypt_stat->keysig_list_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -07002479 return rc;
2480}
Michael Halcrowf4aad162007-10-16 01:27:53 -07002481
2482struct kmem_cache *ecryptfs_key_sig_cache;
2483
2484int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig)
2485{
2486 struct ecryptfs_key_sig *new_key_sig;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002487
2488 new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL);
2489 if (!new_key_sig) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002490 printk(KERN_ERR
2491 "Error allocating from ecryptfs_key_sig_cache\n");
Roland Dreieraa061172009-07-01 15:48:18 -07002492 return -ENOMEM;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002493 }
2494 memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
Roberto Sassu7762e232011-03-21 16:00:52 +01002495 new_key_sig->keysig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
Roland Dreieraa061172009-07-01 15:48:18 -07002496 /* Caller must hold keysig_list_mutex */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002497 list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
Roland Dreieraa061172009-07-01 15:48:18 -07002498
2499 return 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002500}
2501
2502struct kmem_cache *ecryptfs_global_auth_tok_cache;
2503
2504int
2505ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
Tyler Hicks84814d62009-03-13 13:51:59 -07002506 char *sig, u32 global_auth_tok_flags)
Michael Halcrowf4aad162007-10-16 01:27:53 -07002507{
2508 struct ecryptfs_global_auth_tok *new_auth_tok;
2509 int rc = 0;
2510
Eric Sandeen459e2162007-12-17 16:19:52 -08002511 new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache,
Michael Halcrowf4aad162007-10-16 01:27:53 -07002512 GFP_KERNEL);
2513 if (!new_auth_tok) {
2514 rc = -ENOMEM;
2515 printk(KERN_ERR "Error allocating from "
2516 "ecryptfs_global_auth_tok_cache\n");
2517 goto out;
2518 }
2519 memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX);
Tyler Hicks84814d62009-03-13 13:51:59 -07002520 new_auth_tok->flags = global_auth_tok_flags;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002521 new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
2522 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
2523 list_add(&new_auth_tok->mount_crypt_stat_list,
2524 &mount_crypt_stat->global_auth_tok_list);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002525 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
2526out:
2527 return rc;
2528}
2529