blob: 73811cfa2ea4369766a99a251c614ddb091bc8f4 [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/syscalls.h>
30#include <linux/pagemap.h>
31#include <linux/key.h>
32#include <linux/random.h>
33#include <linux/crypto.h>
34#include <linux/scatterlist.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090035#include <linux/slab.h>
Michael Halcrow237fead2006-10-04 02:16:22 -070036#include "ecryptfs_kernel.h"
37
38/**
39 * request_key returned an error instead of a valid key address;
40 * determine the type of error, make appropriate log entries, and
41 * return an error code.
42 */
Michael Halcrowcd9d67d2007-10-16 01:28:04 -070043static int process_request_key_err(long err_code)
Michael Halcrow237fead2006-10-04 02:16:22 -070044{
45 int rc = 0;
46
47 switch (err_code) {
Eric Sandeen982363c2008-07-23 21:30:04 -070048 case -ENOKEY:
Michael Halcrow237fead2006-10-04 02:16:22 -070049 ecryptfs_printk(KERN_WARNING, "No key\n");
50 rc = -ENOENT;
51 break;
Eric Sandeen982363c2008-07-23 21:30:04 -070052 case -EKEYEXPIRED:
Michael Halcrow237fead2006-10-04 02:16:22 -070053 ecryptfs_printk(KERN_WARNING, "Key expired\n");
54 rc = -ETIME;
55 break;
Eric Sandeen982363c2008-07-23 21:30:04 -070056 case -EKEYREVOKED:
Michael Halcrow237fead2006-10-04 02:16:22 -070057 ecryptfs_printk(KERN_WARNING, "Key revoked\n");
58 rc = -EINVAL;
59 break;
60 default:
61 ecryptfs_printk(KERN_WARNING, "Unknown error code: "
62 "[0x%.16x]\n", err_code);
63 rc = -EINVAL;
64 }
65 return rc;
66}
67
Michael Halcrow237fead2006-10-04 02:16:22 -070068/**
Michael Halcrowf66e8832008-04-29 00:59:51 -070069 * ecryptfs_parse_packet_length
Michael Halcrow237fead2006-10-04 02:16:22 -070070 * @data: Pointer to memory containing length at offset
71 * @size: This function writes the decoded size to this memory
72 * address; zero on error
73 * @length_size: The number of bytes occupied by the encoded length
74 *
Michael Halcrow22e78fa2007-10-16 01:28:02 -070075 * Returns zero on success; non-zero on error
Michael Halcrow237fead2006-10-04 02:16:22 -070076 */
Michael Halcrowf66e8832008-04-29 00:59:51 -070077int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
78 size_t *length_size)
Michael Halcrow237fead2006-10-04 02:16:22 -070079{
80 int rc = 0;
81
82 (*length_size) = 0;
83 (*size) = 0;
84 if (data[0] < 192) {
85 /* One-byte length */
Michael Halcrowdddfa462007-02-12 00:53:44 -080086 (*size) = (unsigned char)data[0];
Michael Halcrow237fead2006-10-04 02:16:22 -070087 (*length_size) = 1;
88 } else if (data[0] < 224) {
89 /* Two-byte length */
Michael Halcrowdddfa462007-02-12 00:53:44 -080090 (*size) = (((unsigned char)(data[0]) - 192) * 256);
91 (*size) += ((unsigned char)(data[1]) + 192);
Michael Halcrow237fead2006-10-04 02:16:22 -070092 (*length_size) = 2;
93 } else if (data[0] == 255) {
94 /* Five-byte length; we're not supposed to see this */
95 ecryptfs_printk(KERN_ERR, "Five-byte packet length not "
96 "supported\n");
97 rc = -EINVAL;
98 goto out;
99 } else {
100 ecryptfs_printk(KERN_ERR, "Error parsing packet length\n");
101 rc = -EINVAL;
102 goto out;
103 }
104out:
105 return rc;
106}
107
108/**
Michael Halcrowf66e8832008-04-29 00:59:51 -0700109 * ecryptfs_write_packet_length
Michael Halcrow22e78fa2007-10-16 01:28:02 -0700110 * @dest: The byte array target into which to write the length. Must
111 * have at least 5 bytes allocated.
Michael Halcrow237fead2006-10-04 02:16:22 -0700112 * @size: The length to write.
Michael Halcrow22e78fa2007-10-16 01:28:02 -0700113 * @packet_size_length: The number of bytes used to encode the packet
114 * length is written to this address.
Michael Halcrow237fead2006-10-04 02:16:22 -0700115 *
116 * Returns zero on success; non-zero on error.
117 */
Michael Halcrowf66e8832008-04-29 00:59:51 -0700118int ecryptfs_write_packet_length(char *dest, size_t size,
119 size_t *packet_size_length)
Michael Halcrow237fead2006-10-04 02:16:22 -0700120{
121 int rc = 0;
122
123 if (size < 192) {
124 dest[0] = size;
125 (*packet_size_length) = 1;
126 } else if (size < 65536) {
127 dest[0] = (((size - 192) / 256) + 192);
128 dest[1] = ((size - 192) % 256);
129 (*packet_size_length) = 2;
130 } else {
131 rc = -EINVAL;
132 ecryptfs_printk(KERN_WARNING,
133 "Unsupported packet size: [%d]\n", size);
134 }
135 return rc;
136}
137
Michael Halcrowdddfa462007-02-12 00:53:44 -0800138static int
139write_tag_64_packet(char *signature, struct ecryptfs_session_key *session_key,
140 char **packet, size_t *packet_len)
141{
142 size_t i = 0;
143 size_t data_len;
144 size_t packet_size_len;
145 char *message;
146 int rc;
147
148 /*
149 * ***** TAG 64 Packet Format *****
150 * | Content Type | 1 byte |
151 * | Key Identifier Size | 1 or 2 bytes |
152 * | Key Identifier | arbitrary |
153 * | Encrypted File Encryption Key Size | 1 or 2 bytes |
154 * | Encrypted File Encryption Key | arbitrary |
155 */
156 data_len = (5 + ECRYPTFS_SIG_SIZE_HEX
157 + session_key->encrypted_key_size);
158 *packet = kmalloc(data_len, GFP_KERNEL);
159 message = *packet;
160 if (!message) {
161 ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
162 rc = -ENOMEM;
163 goto out;
164 }
165 message[i++] = ECRYPTFS_TAG_64_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700166 rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
167 &packet_size_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800168 if (rc) {
169 ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet "
170 "header; cannot generate packet length\n");
171 goto out;
172 }
173 i += packet_size_len;
174 memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX);
175 i += ECRYPTFS_SIG_SIZE_HEX;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700176 rc = ecryptfs_write_packet_length(&message[i],
177 session_key->encrypted_key_size,
178 &packet_size_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800179 if (rc) {
180 ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet "
181 "header; cannot generate packet length\n");
182 goto out;
183 }
184 i += packet_size_len;
185 memcpy(&message[i], session_key->encrypted_key,
186 session_key->encrypted_key_size);
187 i += session_key->encrypted_key_size;
188 *packet_len = i;
189out:
190 return rc;
191}
192
193static int
Trevor Highland19e66a62008-02-06 01:38:36 -0800194parse_tag_65_packet(struct ecryptfs_session_key *session_key, u8 *cipher_code,
Michael Halcrowdddfa462007-02-12 00:53:44 -0800195 struct ecryptfs_message *msg)
196{
197 size_t i = 0;
198 char *data;
199 size_t data_len;
200 size_t m_size;
201 size_t message_len;
202 u16 checksum = 0;
203 u16 expected_checksum = 0;
204 int rc;
205
206 /*
207 * ***** TAG 65 Packet Format *****
208 * | Content Type | 1 byte |
209 * | Status Indicator | 1 byte |
210 * | File Encryption Key Size | 1 or 2 bytes |
211 * | File Encryption Key | arbitrary |
212 */
213 message_len = msg->data_len;
214 data = msg->data;
215 if (message_len < 4) {
216 rc = -EIO;
217 goto out;
218 }
219 if (data[i++] != ECRYPTFS_TAG_65_PACKET_TYPE) {
220 ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_65\n");
221 rc = -EIO;
222 goto out;
223 }
224 if (data[i++]) {
225 ecryptfs_printk(KERN_ERR, "Status indicator has non-zero value "
226 "[%d]\n", data[i-1]);
227 rc = -EIO;
228 goto out;
229 }
Michael Halcrowf66e8832008-04-29 00:59:51 -0700230 rc = ecryptfs_parse_packet_length(&data[i], &m_size, &data_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800231 if (rc) {
232 ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
233 "rc = [%d]\n", rc);
234 goto out;
235 }
236 i += data_len;
237 if (message_len < (i + m_size)) {
Tyler Hicks624ae522008-10-15 22:02:51 -0700238 ecryptfs_printk(KERN_ERR, "The message received from ecryptfsd "
239 "is shorter than expected\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -0800240 rc = -EIO;
241 goto out;
242 }
243 if (m_size < 3) {
244 ecryptfs_printk(KERN_ERR,
245 "The decrypted key is not long enough to "
246 "include a cipher code and checksum\n");
247 rc = -EIO;
248 goto out;
249 }
250 *cipher_code = data[i++];
251 /* The decrypted key includes 1 byte cipher code and 2 byte checksum */
252 session_key->decrypted_key_size = m_size - 3;
253 if (session_key->decrypted_key_size > ECRYPTFS_MAX_KEY_BYTES) {
254 ecryptfs_printk(KERN_ERR, "key_size [%d] larger than "
255 "the maximum key size [%d]\n",
256 session_key->decrypted_key_size,
257 ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES);
258 rc = -EIO;
259 goto out;
260 }
261 memcpy(session_key->decrypted_key, &data[i],
262 session_key->decrypted_key_size);
263 i += session_key->decrypted_key_size;
264 expected_checksum += (unsigned char)(data[i++]) << 8;
265 expected_checksum += (unsigned char)(data[i++]);
266 for (i = 0; i < session_key->decrypted_key_size; i++)
267 checksum += session_key->decrypted_key[i];
268 if (expected_checksum != checksum) {
269 ecryptfs_printk(KERN_ERR, "Invalid checksum for file "
270 "encryption key; expected [%x]; calculated "
271 "[%x]\n", expected_checksum, checksum);
272 rc = -EIO;
273 }
274out:
275 return rc;
276}
277
278
279static int
Trevor Highland19e66a62008-02-06 01:38:36 -0800280write_tag_66_packet(char *signature, u8 cipher_code,
Michael Halcrowdddfa462007-02-12 00:53:44 -0800281 struct ecryptfs_crypt_stat *crypt_stat, char **packet,
282 size_t *packet_len)
283{
284 size_t i = 0;
285 size_t j;
286 size_t data_len;
287 size_t checksum = 0;
288 size_t packet_size_len;
289 char *message;
290 int rc;
291
292 /*
293 * ***** TAG 66 Packet Format *****
294 * | Content Type | 1 byte |
295 * | Key Identifier Size | 1 or 2 bytes |
296 * | Key Identifier | arbitrary |
297 * | File Encryption Key Size | 1 or 2 bytes |
298 * | File Encryption Key | arbitrary |
299 */
300 data_len = (5 + ECRYPTFS_SIG_SIZE_HEX + crypt_stat->key_size);
301 *packet = kmalloc(data_len, GFP_KERNEL);
302 message = *packet;
303 if (!message) {
304 ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
305 rc = -ENOMEM;
306 goto out;
307 }
308 message[i++] = ECRYPTFS_TAG_66_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700309 rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
310 &packet_size_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800311 if (rc) {
312 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet "
313 "header; cannot generate packet length\n");
314 goto out;
315 }
316 i += packet_size_len;
317 memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX);
318 i += ECRYPTFS_SIG_SIZE_HEX;
319 /* The encrypted key includes 1 byte cipher code and 2 byte checksum */
Michael Halcrowf66e8832008-04-29 00:59:51 -0700320 rc = ecryptfs_write_packet_length(&message[i], crypt_stat->key_size + 3,
321 &packet_size_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800322 if (rc) {
323 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet "
324 "header; cannot generate packet length\n");
325 goto out;
326 }
327 i += packet_size_len;
328 message[i++] = cipher_code;
329 memcpy(&message[i], crypt_stat->key, crypt_stat->key_size);
330 i += crypt_stat->key_size;
331 for (j = 0; j < crypt_stat->key_size; j++)
332 checksum += crypt_stat->key[j];
333 message[i++] = (checksum / 256) % 256;
334 message[i++] = (checksum % 256);
335 *packet_len = i;
336out:
337 return rc;
338}
339
340static int
341parse_tag_67_packet(struct ecryptfs_key_record *key_rec,
342 struct ecryptfs_message *msg)
343{
344 size_t i = 0;
345 char *data;
346 size_t data_len;
347 size_t message_len;
348 int rc;
349
350 /*
351 * ***** TAG 65 Packet Format *****
352 * | Content Type | 1 byte |
353 * | Status Indicator | 1 byte |
354 * | Encrypted File Encryption Key Size | 1 or 2 bytes |
355 * | Encrypted File Encryption Key | arbitrary |
356 */
357 message_len = msg->data_len;
358 data = msg->data;
359 /* verify that everything through the encrypted FEK size is present */
360 if (message_len < 4) {
361 rc = -EIO;
Michael Halcrowdf261c52009-01-06 14:42:02 -0800362 printk(KERN_ERR "%s: message_len is [%zd]; minimum acceptable "
Michael Halcrowf66e8832008-04-29 00:59:51 -0700363 "message length is [%d]\n", __func__, message_len, 4);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800364 goto out;
365 }
366 if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) {
Michael Halcrowdddfa462007-02-12 00:53:44 -0800367 rc = -EIO;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700368 printk(KERN_ERR "%s: Type should be ECRYPTFS_TAG_67\n",
369 __func__);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800370 goto out;
371 }
372 if (data[i++]) {
Michael Halcrowdddfa462007-02-12 00:53:44 -0800373 rc = -EIO;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700374 printk(KERN_ERR "%s: Status indicator has non zero "
375 "value [%d]\n", __func__, data[i-1]);
376
Michael Halcrowdddfa462007-02-12 00:53:44 -0800377 goto out;
378 }
Michael Halcrowf66e8832008-04-29 00:59:51 -0700379 rc = ecryptfs_parse_packet_length(&data[i], &key_rec->enc_key_size,
380 &data_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800381 if (rc) {
382 ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
383 "rc = [%d]\n", rc);
384 goto out;
385 }
386 i += data_len;
387 if (message_len < (i + key_rec->enc_key_size)) {
Michael Halcrowdddfa462007-02-12 00:53:44 -0800388 rc = -EIO;
Michael Halcrowdf261c52009-01-06 14:42:02 -0800389 printk(KERN_ERR "%s: message_len [%zd]; max len is [%zd]\n",
Michael Halcrowf66e8832008-04-29 00:59:51 -0700390 __func__, message_len, (i + key_rec->enc_key_size));
Michael Halcrowdddfa462007-02-12 00:53:44 -0800391 goto out;
392 }
393 if (key_rec->enc_key_size > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
Michael Halcrowdddfa462007-02-12 00:53:44 -0800394 rc = -EIO;
Michael Halcrowdf261c52009-01-06 14:42:02 -0800395 printk(KERN_ERR "%s: Encrypted key_size [%zd] larger than "
Michael Halcrowf66e8832008-04-29 00:59:51 -0700396 "the maximum key size [%d]\n", __func__,
397 key_rec->enc_key_size,
398 ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800399 goto out;
400 }
401 memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size);
402out:
403 return rc;
404}
405
Michael Halcrowcd9d67d2007-10-16 01:28:04 -0700406static int
Michael Halcrow9c79f342009-01-06 14:41:57 -0800407ecryptfs_find_global_auth_tok_for_sig(
408 struct ecryptfs_global_auth_tok **global_auth_tok,
409 struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig)
410{
411 struct ecryptfs_global_auth_tok *walker;
412 int rc = 0;
413
414 (*global_auth_tok) = NULL;
415 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
416 list_for_each_entry(walker,
417 &mount_crypt_stat->global_auth_tok_list,
418 mount_crypt_stat_list) {
419 if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX) == 0) {
Tyler Hicks38919592009-08-26 01:54:56 -0500420 rc = key_validate(walker->global_auth_tok_key);
421 if (!rc)
422 (*global_auth_tok) = walker;
Michael Halcrow9c79f342009-01-06 14:41:57 -0800423 goto out;
424 }
425 }
426 rc = -EINVAL;
427out:
428 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
429 return rc;
430}
431
432/**
433 * ecryptfs_find_auth_tok_for_sig
434 * @auth_tok: Set to the matching auth_tok; NULL if not found
435 * @crypt_stat: inode crypt_stat crypto context
436 * @sig: Sig of auth_tok to find
437 *
438 * For now, this function simply looks at the registered auth_tok's
439 * linked off the mount_crypt_stat, so all the auth_toks that can be
440 * used must be registered at mount time. This function could
441 * potentially try a lot harder to find auth_tok's (e.g., by calling
442 * out to ecryptfsd to dynamically retrieve an auth_tok object) so
443 * that static registration of auth_tok's will no longer be necessary.
444 *
445 * Returns zero on no error; non-zero on error
446 */
447static int
448ecryptfs_find_auth_tok_for_sig(
449 struct ecryptfs_auth_tok **auth_tok,
450 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
451 char *sig)
452{
453 struct ecryptfs_global_auth_tok *global_auth_tok;
454 int rc = 0;
455
456 (*auth_tok) = NULL;
457 if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
458 mount_crypt_stat, sig)) {
459 struct key *auth_tok_key;
460
461 rc = ecryptfs_keyring_auth_tok_for_sig(&auth_tok_key, auth_tok,
462 sig);
463 } else
464 (*auth_tok) = global_auth_tok->global_auth_tok;
465 return rc;
466}
467
468/**
469 * write_tag_70_packet can gobble a lot of stack space. We stuff most
470 * of the function's parameters in a kmalloc'd struct to help reduce
471 * eCryptfs' overall stack usage.
472 */
473struct ecryptfs_write_tag_70_packet_silly_stack {
474 u8 cipher_code;
475 size_t max_packet_size;
476 size_t packet_size_len;
477 size_t block_aligned_filename_size;
478 size_t block_size;
479 size_t i;
480 size_t j;
481 size_t num_rand_bytes;
482 struct mutex *tfm_mutex;
483 char *block_aligned_filename;
484 struct ecryptfs_auth_tok *auth_tok;
485 struct scatterlist src_sg;
486 struct scatterlist dst_sg;
487 struct blkcipher_desc desc;
488 char iv[ECRYPTFS_MAX_IV_BYTES];
489 char hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
490 char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
491 struct hash_desc hash_desc;
492 struct scatterlist hash_sg;
493};
494
495/**
496 * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK
497 * @filename: NULL-terminated filename string
498 *
499 * This is the simplest mechanism for achieving filename encryption in
500 * eCryptfs. It encrypts the given filename with the mount-wide
501 * filename encryption key (FNEK) and stores it in a packet to @dest,
502 * which the callee will encode and write directly into the dentry
503 * name.
504 */
505int
506ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
507 size_t *packet_size,
508 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
509 char *filename, size_t filename_size)
510{
511 struct ecryptfs_write_tag_70_packet_silly_stack *s;
512 int rc = 0;
513
514 s = kmalloc(sizeof(*s), GFP_KERNEL);
515 if (!s) {
516 printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
Michael Halcrowdf261c52009-01-06 14:42:02 -0800517 "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
Julia Lawallf137f152010-08-11 12:11:41 +0200518 rc = -ENOMEM;
Michael Halcrow9c79f342009-01-06 14:41:57 -0800519 goto out;
520 }
521 s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
522 (*packet_size) = 0;
523 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(
524 &s->desc.tfm,
525 &s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name);
526 if (unlikely(rc)) {
527 printk(KERN_ERR "Internal error whilst attempting to get "
528 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
529 mount_crypt_stat->global_default_fn_cipher_name, rc);
530 goto out;
531 }
532 mutex_lock(s->tfm_mutex);
533 s->block_size = crypto_blkcipher_blocksize(s->desc.tfm);
534 /* Plus one for the \0 separator between the random prefix
535 * and the plaintext filename */
536 s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1);
537 s->block_aligned_filename_size = (s->num_rand_bytes + filename_size);
538 if ((s->block_aligned_filename_size % s->block_size) != 0) {
539 s->num_rand_bytes += (s->block_size
540 - (s->block_aligned_filename_size
541 % s->block_size));
542 s->block_aligned_filename_size = (s->num_rand_bytes
543 + filename_size);
544 }
545 /* Octet 0: Tag 70 identifier
546 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
547 * and block-aligned encrypted filename size)
548 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
549 * Octet N2-N3: Cipher identifier (1 octet)
550 * Octets N3-N4: Block-aligned encrypted filename
551 * - Consists of a minimum number of random characters, a \0
552 * separator, and then the filename */
553 s->max_packet_size = (1 /* Tag 70 identifier */
554 + 3 /* Max Tag 70 packet size */
555 + ECRYPTFS_SIG_SIZE /* FNEK sig */
556 + 1 /* Cipher identifier */
557 + s->block_aligned_filename_size);
558 if (dest == NULL) {
559 (*packet_size) = s->max_packet_size;
560 goto out_unlock;
561 }
562 if (s->max_packet_size > (*remaining_bytes)) {
Michael Halcrowa8f12862009-01-06 14:42:03 -0800563 printk(KERN_WARNING "%s: Require [%zd] bytes to write; only "
564 "[%zd] available\n", __func__, s->max_packet_size,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800565 (*remaining_bytes));
566 rc = -EINVAL;
567 goto out_unlock;
568 }
569 s->block_aligned_filename = kzalloc(s->block_aligned_filename_size,
570 GFP_KERNEL);
571 if (!s->block_aligned_filename) {
572 printk(KERN_ERR "%s: Out of kernel memory whilst attempting to "
Michael Halcrowdf261c52009-01-06 14:42:02 -0800573 "kzalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800574 s->block_aligned_filename_size);
575 rc = -ENOMEM;
576 goto out_unlock;
577 }
578 s->i = 0;
579 dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE;
580 rc = ecryptfs_write_packet_length(&dest[s->i],
581 (ECRYPTFS_SIG_SIZE
582 + 1 /* Cipher code */
583 + s->block_aligned_filename_size),
584 &s->packet_size_len);
585 if (rc) {
586 printk(KERN_ERR "%s: Error generating tag 70 packet "
587 "header; cannot generate packet length; rc = [%d]\n",
588 __func__, rc);
589 goto out_free_unlock;
590 }
591 s->i += s->packet_size_len;
592 ecryptfs_from_hex(&dest[s->i],
593 mount_crypt_stat->global_default_fnek_sig,
594 ECRYPTFS_SIG_SIZE);
595 s->i += ECRYPTFS_SIG_SIZE;
596 s->cipher_code = ecryptfs_code_for_cipher_string(
597 mount_crypt_stat->global_default_fn_cipher_name,
598 mount_crypt_stat->global_default_fn_cipher_key_bytes);
599 if (s->cipher_code == 0) {
600 printk(KERN_WARNING "%s: Unable to generate code for "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800601 "cipher [%s] with key bytes [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800602 mount_crypt_stat->global_default_fn_cipher_name,
603 mount_crypt_stat->global_default_fn_cipher_key_bytes);
604 rc = -EINVAL;
605 goto out_free_unlock;
606 }
607 dest[s->i++] = s->cipher_code;
608 rc = ecryptfs_find_auth_tok_for_sig(
609 &s->auth_tok, mount_crypt_stat,
610 mount_crypt_stat->global_default_fnek_sig);
611 if (rc) {
612 printk(KERN_ERR "%s: Error attempting to find auth tok for "
613 "fnek sig [%s]; rc = [%d]\n", __func__,
614 mount_crypt_stat->global_default_fnek_sig, rc);
615 goto out_free_unlock;
616 }
617 /* TODO: Support other key modules than passphrase for
618 * filename encryption */
Tyler Hicksdf6ad332009-08-21 04:27:46 -0500619 if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {
620 rc = -EOPNOTSUPP;
621 printk(KERN_INFO "%s: Filename encryption only supports "
622 "password tokens\n", __func__);
623 goto out_free_unlock;
624 }
Michael Halcrow9c79f342009-01-06 14:41:57 -0800625 sg_init_one(
626 &s->hash_sg,
627 (u8 *)s->auth_tok->token.password.session_key_encryption_key,
628 s->auth_tok->token.password.session_key_encryption_key_bytes);
629 s->hash_desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
630 s->hash_desc.tfm = crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST, 0,
631 CRYPTO_ALG_ASYNC);
632 if (IS_ERR(s->hash_desc.tfm)) {
633 rc = PTR_ERR(s->hash_desc.tfm);
634 printk(KERN_ERR "%s: Error attempting to "
635 "allocate hash crypto context; rc = [%d]\n",
636 __func__, rc);
637 goto out_free_unlock;
638 }
639 rc = crypto_hash_init(&s->hash_desc);
640 if (rc) {
641 printk(KERN_ERR
642 "%s: Error initializing crypto hash; rc = [%d]\n",
643 __func__, rc);
644 goto out_release_free_unlock;
645 }
646 rc = crypto_hash_update(
647 &s->hash_desc, &s->hash_sg,
648 s->auth_tok->token.password.session_key_encryption_key_bytes);
649 if (rc) {
650 printk(KERN_ERR
651 "%s: Error updating crypto hash; rc = [%d]\n",
652 __func__, rc);
653 goto out_release_free_unlock;
654 }
655 rc = crypto_hash_final(&s->hash_desc, s->hash);
656 if (rc) {
657 printk(KERN_ERR
658 "%s: Error finalizing crypto hash; rc = [%d]\n",
659 __func__, rc);
660 goto out_release_free_unlock;
661 }
662 for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) {
663 s->block_aligned_filename[s->j] =
664 s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)];
665 if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)
666 == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) {
667 sg_init_one(&s->hash_sg, (u8 *)s->hash,
668 ECRYPTFS_TAG_70_DIGEST_SIZE);
669 rc = crypto_hash_init(&s->hash_desc);
670 if (rc) {
671 printk(KERN_ERR
672 "%s: Error initializing crypto hash; "
673 "rc = [%d]\n", __func__, rc);
674 goto out_release_free_unlock;
675 }
676 rc = crypto_hash_update(&s->hash_desc, &s->hash_sg,
677 ECRYPTFS_TAG_70_DIGEST_SIZE);
678 if (rc) {
679 printk(KERN_ERR
680 "%s: Error updating crypto hash; "
681 "rc = [%d]\n", __func__, rc);
682 goto out_release_free_unlock;
683 }
684 rc = crypto_hash_final(&s->hash_desc, s->tmp_hash);
685 if (rc) {
686 printk(KERN_ERR
687 "%s: Error finalizing crypto hash; "
688 "rc = [%d]\n", __func__, rc);
689 goto out_release_free_unlock;
690 }
691 memcpy(s->hash, s->tmp_hash,
692 ECRYPTFS_TAG_70_DIGEST_SIZE);
693 }
694 if (s->block_aligned_filename[s->j] == '\0')
695 s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL;
696 }
697 memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename,
698 filename_size);
699 rc = virt_to_scatterlist(s->block_aligned_filename,
700 s->block_aligned_filename_size, &s->src_sg, 1);
701 if (rc != 1) {
702 printk(KERN_ERR "%s: Internal error whilst attempting to "
703 "convert filename memory to scatterlist; "
704 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800705 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800706 s->block_aligned_filename_size);
707 goto out_release_free_unlock;
708 }
709 rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size,
710 &s->dst_sg, 1);
711 if (rc != 1) {
712 printk(KERN_ERR "%s: Internal error whilst attempting to "
713 "convert encrypted filename memory to scatterlist; "
714 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800715 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800716 s->block_aligned_filename_size);
717 goto out_release_free_unlock;
718 }
719 /* The characters in the first block effectively do the job
720 * of the IV here, so we just use 0's for the IV. Note the
721 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
722 * >= ECRYPTFS_MAX_IV_BYTES. */
723 memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
724 s->desc.info = s->iv;
725 rc = crypto_blkcipher_setkey(
726 s->desc.tfm,
727 s->auth_tok->token.password.session_key_encryption_key,
728 mount_crypt_stat->global_default_fn_cipher_key_bytes);
729 if (rc < 0) {
730 printk(KERN_ERR "%s: Error setting key for crypto context; "
731 "rc = [%d]. s->auth_tok->token.password.session_key_"
732 "encryption_key = [0x%p]; mount_crypt_stat->"
Michael Halcrowdf261c52009-01-06 14:42:02 -0800733 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800734 rc,
735 s->auth_tok->token.password.session_key_encryption_key,
736 mount_crypt_stat->global_default_fn_cipher_key_bytes);
737 goto out_release_free_unlock;
738 }
739 rc = crypto_blkcipher_encrypt_iv(&s->desc, &s->dst_sg, &s->src_sg,
740 s->block_aligned_filename_size);
741 if (rc) {
742 printk(KERN_ERR "%s: Error attempting to encrypt filename; "
743 "rc = [%d]\n", __func__, rc);
744 goto out_release_free_unlock;
745 }
746 s->i += s->block_aligned_filename_size;
747 (*packet_size) = s->i;
748 (*remaining_bytes) -= (*packet_size);
749out_release_free_unlock:
750 crypto_free_hash(s->hash_desc.tfm);
751out_free_unlock:
Johannes Weiner00fcf2c2009-03-31 15:24:42 -0700752 kzfree(s->block_aligned_filename);
Michael Halcrow9c79f342009-01-06 14:41:57 -0800753out_unlock:
754 mutex_unlock(s->tfm_mutex);
755out:
756 kfree(s);
757 return rc;
758}
759
760struct ecryptfs_parse_tag_70_packet_silly_stack {
761 u8 cipher_code;
762 size_t max_packet_size;
763 size_t packet_size_len;
764 size_t parsed_tag_70_packet_size;
765 size_t block_aligned_filename_size;
766 size_t block_size;
767 size_t i;
768 struct mutex *tfm_mutex;
769 char *decrypted_filename;
770 struct ecryptfs_auth_tok *auth_tok;
771 struct scatterlist src_sg;
772 struct scatterlist dst_sg;
773 struct blkcipher_desc desc;
774 char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1];
775 char iv[ECRYPTFS_MAX_IV_BYTES];
776 char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE];
777};
778
779/**
780 * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet
781 * @filename: This function kmalloc's the memory for the filename
Michael Halcrow7d8bc2b2009-01-06 14:42:04 -0800782 * @filename_size: This function sets this to the amount of memory
783 * kmalloc'd for the filename
784 * @packet_size: This function sets this to the the number of octets
785 * in the packet parsed
786 * @mount_crypt_stat: The mount-wide cryptographic context
787 * @data: The memory location containing the start of the tag 70
788 * packet
789 * @max_packet_size: The maximum legal size of the packet to be parsed
790 * from @data
791 *
792 * Returns zero on success; non-zero otherwise
Michael Halcrow9c79f342009-01-06 14:41:57 -0800793 */
794int
795ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
796 size_t *packet_size,
797 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
798 char *data, size_t max_packet_size)
799{
800 struct ecryptfs_parse_tag_70_packet_silly_stack *s;
801 int rc = 0;
802
803 (*packet_size) = 0;
804 (*filename_size) = 0;
805 (*filename) = NULL;
806 s = kmalloc(sizeof(*s), GFP_KERNEL);
807 if (!s) {
808 printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800809 "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
Julia Lawallf137f152010-08-11 12:11:41 +0200810 rc = -ENOMEM;
Michael Halcrow9c79f342009-01-06 14:41:57 -0800811 goto out;
812 }
813 s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
814 if (max_packet_size < (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)) {
Michael Halcrowdf261c52009-01-06 14:42:02 -0800815 printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be "
Michael Halcrow9c79f342009-01-06 14:41:57 -0800816 "at least [%d]\n", __func__, max_packet_size,
817 (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1));
818 rc = -EINVAL;
819 goto out;
820 }
821 /* Octet 0: Tag 70 identifier
822 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
823 * and block-aligned encrypted filename size)
824 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
825 * Octet N2-N3: Cipher identifier (1 octet)
826 * Octets N3-N4: Block-aligned encrypted filename
827 * - Consists of a minimum number of random numbers, a \0
828 * separator, and then the filename */
829 if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) {
830 printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be "
831 "tag [0x%.2x]\n", __func__,
832 data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE);
833 rc = -EINVAL;
834 goto out;
835 }
836 rc = ecryptfs_parse_packet_length(&data[(*packet_size)],
837 &s->parsed_tag_70_packet_size,
838 &s->packet_size_len);
839 if (rc) {
840 printk(KERN_WARNING "%s: Error parsing packet length; "
841 "rc = [%d]\n", __func__, rc);
842 goto out;
843 }
844 s->block_aligned_filename_size = (s->parsed_tag_70_packet_size
845 - ECRYPTFS_SIG_SIZE - 1);
846 if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size)
847 > max_packet_size) {
Michael Halcrowa8f12862009-01-06 14:42:03 -0800848 printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet "
849 "size is [%zd]\n", __func__, max_packet_size,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800850 (1 + s->packet_size_len + 1
851 + s->block_aligned_filename_size));
852 rc = -EINVAL;
853 goto out;
854 }
855 (*packet_size) += s->packet_size_len;
856 ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)],
857 ECRYPTFS_SIG_SIZE);
858 s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0';
859 (*packet_size) += ECRYPTFS_SIG_SIZE;
860 s->cipher_code = data[(*packet_size)++];
861 rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code);
862 if (rc) {
863 printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n",
864 __func__, s->cipher_code);
865 goto out;
866 }
867 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm,
868 &s->tfm_mutex,
869 s->cipher_string);
870 if (unlikely(rc)) {
871 printk(KERN_ERR "Internal error whilst attempting to get "
872 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
873 s->cipher_string, rc);
874 goto out;
875 }
876 mutex_lock(s->tfm_mutex);
877 rc = virt_to_scatterlist(&data[(*packet_size)],
878 s->block_aligned_filename_size, &s->src_sg, 1);
879 if (rc != 1) {
880 printk(KERN_ERR "%s: Internal error whilst attempting to "
881 "convert encrypted filename memory to scatterlist; "
882 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800883 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800884 s->block_aligned_filename_size);
885 goto out_unlock;
886 }
887 (*packet_size) += s->block_aligned_filename_size;
888 s->decrypted_filename = kmalloc(s->block_aligned_filename_size,
889 GFP_KERNEL);
890 if (!s->decrypted_filename) {
891 printk(KERN_ERR "%s: Out of memory whilst attempting to "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800892 "kmalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800893 s->block_aligned_filename_size);
894 rc = -ENOMEM;
895 goto out_unlock;
896 }
897 rc = virt_to_scatterlist(s->decrypted_filename,
898 s->block_aligned_filename_size, &s->dst_sg, 1);
899 if (rc != 1) {
900 printk(KERN_ERR "%s: Internal error whilst attempting to "
901 "convert decrypted filename memory to scatterlist; "
902 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800903 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800904 s->block_aligned_filename_size);
905 goto out_free_unlock;
906 }
907 /* The characters in the first block effectively do the job of
908 * the IV here, so we just use 0's for the IV. Note the
909 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
910 * >= ECRYPTFS_MAX_IV_BYTES. */
911 memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
912 s->desc.info = s->iv;
913 rc = ecryptfs_find_auth_tok_for_sig(&s->auth_tok, mount_crypt_stat,
914 s->fnek_sig_hex);
915 if (rc) {
916 printk(KERN_ERR "%s: Error attempting to find auth tok for "
917 "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex,
918 rc);
919 goto out_free_unlock;
920 }
921 /* TODO: Support other key modules than passphrase for
922 * filename encryption */
Tyler Hicksdf6ad332009-08-21 04:27:46 -0500923 if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {
924 rc = -EOPNOTSUPP;
925 printk(KERN_INFO "%s: Filename encryption only supports "
926 "password tokens\n", __func__);
927 goto out_free_unlock;
928 }
Michael Halcrow9c79f342009-01-06 14:41:57 -0800929 rc = crypto_blkcipher_setkey(
930 s->desc.tfm,
931 s->auth_tok->token.password.session_key_encryption_key,
932 mount_crypt_stat->global_default_fn_cipher_key_bytes);
933 if (rc < 0) {
934 printk(KERN_ERR "%s: Error setting key for crypto context; "
935 "rc = [%d]. s->auth_tok->token.password.session_key_"
936 "encryption_key = [0x%p]; mount_crypt_stat->"
Michael Halcrowdf261c52009-01-06 14:42:02 -0800937 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800938 rc,
939 s->auth_tok->token.password.session_key_encryption_key,
940 mount_crypt_stat->global_default_fn_cipher_key_bytes);
941 goto out_free_unlock;
942 }
943 rc = crypto_blkcipher_decrypt_iv(&s->desc, &s->dst_sg, &s->src_sg,
944 s->block_aligned_filename_size);
945 if (rc) {
946 printk(KERN_ERR "%s: Error attempting to decrypt filename; "
947 "rc = [%d]\n", __func__, rc);
948 goto out_free_unlock;
949 }
950 s->i = 0;
951 while (s->decrypted_filename[s->i] != '\0'
952 && s->i < s->block_aligned_filename_size)
953 s->i++;
954 if (s->i == s->block_aligned_filename_size) {
955 printk(KERN_WARNING "%s: Invalid tag 70 packet; could not "
956 "find valid separator between random characters and "
957 "the filename\n", __func__);
958 rc = -EINVAL;
959 goto out_free_unlock;
960 }
961 s->i++;
962 (*filename_size) = (s->block_aligned_filename_size - s->i);
963 if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) {
Michael Halcrowdf261c52009-01-06 14:42:02 -0800964 printk(KERN_WARNING "%s: Filename size is [%zd], which is "
Michael Halcrow9c79f342009-01-06 14:41:57 -0800965 "invalid\n", __func__, (*filename_size));
966 rc = -EINVAL;
967 goto out_free_unlock;
968 }
969 (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL);
970 if (!(*filename)) {
971 printk(KERN_ERR "%s: Out of memory whilst attempting to "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800972 "kmalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800973 ((*filename_size) + 1));
974 rc = -ENOMEM;
975 goto out_free_unlock;
976 }
977 memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size));
978 (*filename)[(*filename_size)] = '\0';
979out_free_unlock:
980 kfree(s->decrypted_filename);
981out_unlock:
982 mutex_unlock(s->tfm_mutex);
983out:
984 if (rc) {
985 (*packet_size) = 0;
986 (*filename_size) = 0;
987 (*filename) = NULL;
988 }
989 kfree(s);
990 return rc;
991}
992
993static int
Michael Halcrowcd9d67d2007-10-16 01:28:04 -0700994ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok)
995{
996 int rc = 0;
997
998 (*sig) = NULL;
999 switch (auth_tok->token_type) {
1000 case ECRYPTFS_PASSWORD:
1001 (*sig) = auth_tok->token.password.signature;
1002 break;
1003 case ECRYPTFS_PRIVATE_KEY:
1004 (*sig) = auth_tok->token.private_key.signature;
1005 break;
1006 default:
1007 printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n",
1008 auth_tok->token_type);
1009 rc = -EINVAL;
1010 }
1011 return rc;
1012}
1013
Michael Halcrowdddfa462007-02-12 00:53:44 -08001014/**
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001015 * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok.
1016 * @auth_tok: The key authentication token used to decrypt the session key
1017 * @crypt_stat: The cryptographic context
Michael Halcrowdddfa462007-02-12 00:53:44 -08001018 *
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001019 * Returns zero on success; non-zero error otherwise.
Michael Halcrowdddfa462007-02-12 00:53:44 -08001020 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07001021static int
1022decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1023 struct ecryptfs_crypt_stat *crypt_stat)
Michael Halcrowdddfa462007-02-12 00:53:44 -08001024{
Trevor Highland19e66a62008-02-06 01:38:36 -08001025 u8 cipher_code = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001026 struct ecryptfs_msg_ctx *msg_ctx;
1027 struct ecryptfs_message *msg = NULL;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001028 char *auth_tok_sig;
Tyler Hicks624ae522008-10-15 22:02:51 -07001029 char *payload;
1030 size_t payload_len;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001031 int rc;
1032
Michael Halcrow5dda6992007-10-16 01:28:06 -07001033 rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok);
1034 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001035 printk(KERN_ERR "Unrecognized auth tok type: [%d]\n",
1036 auth_tok->token_type);
1037 goto out;
1038 }
1039 rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key),
Tyler Hicks624ae522008-10-15 22:02:51 -07001040 &payload, &payload_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001041 if (rc) {
Michael Halcrowf66e8832008-04-29 00:59:51 -07001042 ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001043 goto out;
1044 }
Tyler Hicks624ae522008-10-15 22:02:51 -07001045 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001046 if (rc) {
Tyler Hicks624ae522008-10-15 22:02:51 -07001047 ecryptfs_printk(KERN_ERR, "Error sending message to "
1048 "ecryptfsd\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001049 goto out;
1050 }
1051 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1052 if (rc) {
1053 ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet "
1054 "from the user space daemon\n");
1055 rc = -EIO;
1056 goto out;
1057 }
1058 rc = parse_tag_65_packet(&(auth_tok->session_key),
1059 &cipher_code, msg);
1060 if (rc) {
1061 printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n",
1062 rc);
1063 goto out;
1064 }
1065 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1066 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1067 auth_tok->session_key.decrypted_key_size);
1068 crypt_stat->key_size = auth_tok->session_key.decrypted_key_size;
1069 rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code);
1070 if (rc) {
1071 ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n",
1072 cipher_code)
1073 goto out;
1074 }
1075 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1076 if (ecryptfs_verbosity > 0) {
1077 ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n");
1078 ecryptfs_dump_hex(crypt_stat->key,
1079 crypt_stat->key_size);
1080 }
1081out:
1082 if (msg)
1083 kfree(msg);
1084 return rc;
1085}
1086
1087static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
1088{
Michael Halcrowdddfa462007-02-12 00:53:44 -08001089 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
Michael Halcrowe0869cc2007-10-16 01:27:55 -07001090 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001091
Michael Halcrowe0869cc2007-10-16 01:27:55 -07001092 list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp,
1093 auth_tok_list_head, list) {
1094 list_del(&auth_tok_list_item->list);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001095 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1096 auth_tok_list_item);
1097 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001098}
1099
1100struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
1101
Michael Halcrowdddfa462007-02-12 00:53:44 -08001102/**
1103 * parse_tag_1_packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001104 * @crypt_stat: The cryptographic context to modify based on packet contents
Michael Halcrowdddfa462007-02-12 00:53:44 -08001105 * @data: The raw bytes of the packet.
1106 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001107 * a new authentication token will be placed at the
1108 * end of this list for this packet.
Michael Halcrowdddfa462007-02-12 00:53:44 -08001109 * @new_auth_tok: Pointer to a pointer to memory that this function
1110 * allocates; sets the memory address of the pointer to
1111 * NULL on error. This object is added to the
1112 * auth_tok_list.
1113 * @packet_size: This function writes the size of the parsed packet
1114 * into this memory location; zero on error.
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001115 * @max_packet_size: The maximum allowable packet size
Michael Halcrowdddfa462007-02-12 00:53:44 -08001116 *
1117 * Returns zero on success; non-zero on error.
1118 */
1119static int
1120parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
1121 unsigned char *data, struct list_head *auth_tok_list,
1122 struct ecryptfs_auth_tok **new_auth_tok,
1123 size_t *packet_size, size_t max_packet_size)
1124{
1125 size_t body_size;
1126 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1127 size_t length_size;
1128 int rc = 0;
1129
1130 (*packet_size) = 0;
1131 (*new_auth_tok) = NULL;
Michael Halcrow132181792007-10-16 01:27:56 -07001132 /**
1133 * This format is inspired by OpenPGP; see RFC 2440
1134 * packet tag 1
1135 *
1136 * Tag 1 identifier (1 byte)
1137 * Max Tag 1 packet size (max 3 bytes)
1138 * Version (1 byte)
1139 * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE)
1140 * Cipher identifier (1 byte)
1141 * Encrypted key size (arbitrary)
1142 *
1143 * 12 bytes minimum packet size
Michael Halcrowdddfa462007-02-12 00:53:44 -08001144 */
Michael Halcrow132181792007-10-16 01:27:56 -07001145 if (unlikely(max_packet_size < 12)) {
1146 printk(KERN_ERR "Invalid max packet size; must be >=12\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001147 rc = -EINVAL;
1148 goto out;
1149 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001150 if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) {
Michael Halcrow132181792007-10-16 01:27:56 -07001151 printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n",
1152 ECRYPTFS_TAG_1_PACKET_TYPE);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001153 rc = -EINVAL;
1154 goto out;
1155 }
1156 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1157 * at end of function upon failure */
1158 auth_tok_list_item =
Michael Halcrow132181792007-10-16 01:27:56 -07001159 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache,
1160 GFP_KERNEL);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001161 if (!auth_tok_list_item) {
Michael Halcrow132181792007-10-16 01:27:56 -07001162 printk(KERN_ERR "Unable to allocate memory\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001163 rc = -ENOMEM;
1164 goto out;
1165 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001166 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001167 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1168 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001169 if (rc) {
Michael Halcrow132181792007-10-16 01:27:56 -07001170 printk(KERN_WARNING "Error parsing packet length; "
1171 "rc = [%d]\n", rc);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001172 goto out_free;
1173 }
Michael Halcrow132181792007-10-16 01:27:56 -07001174 if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001175 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001176 rc = -EINVAL;
1177 goto out_free;
1178 }
1179 (*packet_size) += length_size;
1180 if (unlikely((*packet_size) + body_size > max_packet_size)) {
Michael Halcrow132181792007-10-16 01:27:56 -07001181 printk(KERN_WARNING "Packet size exceeds max\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001182 rc = -EINVAL;
1183 goto out_free;
1184 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001185 if (unlikely(data[(*packet_size)++] != 0x03)) {
Michael Halcrow132181792007-10-16 01:27:56 -07001186 printk(KERN_WARNING "Unknown version number [%d]\n",
1187 data[(*packet_size) - 1]);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001188 rc = -EINVAL;
1189 goto out_free;
1190 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001191 ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
1192 &data[(*packet_size)], ECRYPTFS_SIG_SIZE);
1193 *packet_size += ECRYPTFS_SIG_SIZE;
1194 /* This byte is skipped because the kernel does not need to
1195 * know which public key encryption algorithm was used */
1196 (*packet_size)++;
1197 (*new_auth_tok)->session_key.encrypted_key_size =
Michael Halcrow132181792007-10-16 01:27:56 -07001198 body_size - (ECRYPTFS_SIG_SIZE + 2);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001199 if ((*new_auth_tok)->session_key.encrypted_key_size
1200 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
Michael Halcrow132181792007-10-16 01:27:56 -07001201 printk(KERN_WARNING "Tag 1 packet contains key larger "
1202 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001203 rc = -EINVAL;
1204 goto out;
1205 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001206 memcpy((*new_auth_tok)->session_key.encrypted_key,
Michael Halcrow132181792007-10-16 01:27:56 -07001207 &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2)));
Michael Halcrowdddfa462007-02-12 00:53:44 -08001208 (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size;
1209 (*new_auth_tok)->session_key.flags &=
1210 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1211 (*new_auth_tok)->session_key.flags |=
1212 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
1213 (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY;
Michael Halcrow132181792007-10-16 01:27:56 -07001214 (*new_auth_tok)->flags = 0;
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001215 (*new_auth_tok)->session_key.flags &=
1216 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1217 (*new_auth_tok)->session_key.flags &=
1218 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001219 list_add(&auth_tok_list_item->list, auth_tok_list);
1220 goto out;
1221out_free:
1222 (*new_auth_tok) = NULL;
1223 memset(auth_tok_list_item, 0,
1224 sizeof(struct ecryptfs_auth_tok_list_item));
1225 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1226 auth_tok_list_item);
1227out:
1228 if (rc)
1229 (*packet_size) = 0;
1230 return rc;
1231}
1232
Michael Halcrow237fead2006-10-04 02:16:22 -07001233/**
1234 * parse_tag_3_packet
1235 * @crypt_stat: The cryptographic context to modify based on packet
1236 * contents.
1237 * @data: The raw bytes of the packet.
1238 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
1239 * a new authentication token will be placed at the end
1240 * of this list for this packet.
1241 * @new_auth_tok: Pointer to a pointer to memory that this function
1242 * allocates; sets the memory address of the pointer to
1243 * NULL on error. This object is added to the
1244 * auth_tok_list.
1245 * @packet_size: This function writes the size of the parsed packet
1246 * into this memory location; zero on error.
1247 * @max_packet_size: maximum number of bytes to parse
1248 *
1249 * Returns zero on success; non-zero on error.
1250 */
1251static int
1252parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
1253 unsigned char *data, struct list_head *auth_tok_list,
1254 struct ecryptfs_auth_tok **new_auth_tok,
1255 size_t *packet_size, size_t max_packet_size)
1256{
Michael Halcrow237fead2006-10-04 02:16:22 -07001257 size_t body_size;
1258 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1259 size_t length_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001260 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001261
1262 (*packet_size) = 0;
1263 (*new_auth_tok) = NULL;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001264 /**
1265 *This format is inspired by OpenPGP; see RFC 2440
1266 * packet tag 3
1267 *
1268 * Tag 3 identifier (1 byte)
1269 * Max Tag 3 packet size (max 3 bytes)
1270 * Version (1 byte)
1271 * Cipher code (1 byte)
1272 * S2K specifier (1 byte)
1273 * Hash identifier (1 byte)
1274 * Salt (ECRYPTFS_SALT_SIZE)
1275 * Hash iterations (1 byte)
1276 * Encrypted key (arbitrary)
1277 *
1278 * (ECRYPTFS_SALT_SIZE + 7) minimum packet size
Michael Halcrow237fead2006-10-04 02:16:22 -07001279 */
Michael Halcrowc59becf2007-10-16 01:27:56 -07001280 if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) {
1281 printk(KERN_ERR "Max packet size too large\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001282 rc = -EINVAL;
1283 goto out;
1284 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001285 if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001286 printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n",
1287 ECRYPTFS_TAG_3_PACKET_TYPE);
Michael Halcrow237fead2006-10-04 02:16:22 -07001288 rc = -EINVAL;
1289 goto out;
1290 }
1291 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1292 * at end of function upon failure */
1293 auth_tok_list_item =
Robert P. J. Dayc3762222007-02-10 01:45:03 -08001294 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
Michael Halcrow237fead2006-10-04 02:16:22 -07001295 if (!auth_tok_list_item) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001296 printk(KERN_ERR "Unable to allocate memory\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001297 rc = -ENOMEM;
1298 goto out;
1299 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001300 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001301 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1302 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001303 if (rc) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001304 printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n",
1305 rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07001306 goto out_free;
1307 }
Michael Halcrowc59becf2007-10-16 01:27:56 -07001308 if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001309 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001310 rc = -EINVAL;
1311 goto out_free;
1312 }
1313 (*packet_size) += length_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07001314 if (unlikely((*packet_size) + body_size > max_packet_size)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001315 printk(KERN_ERR "Packet size exceeds max\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001316 rc = -EINVAL;
1317 goto out_free;
1318 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001319 (*new_auth_tok)->session_key.encrypted_key_size =
Michael Halcrowc59becf2007-10-16 01:27:56 -07001320 (body_size - (ECRYPTFS_SALT_SIZE + 5));
Ramon de Carvalho Vallef151cd22009-07-28 13:58:22 -05001321 if ((*new_auth_tok)->session_key.encrypted_key_size
1322 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
1323 printk(KERN_WARNING "Tag 3 packet contains key larger "
1324 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n");
1325 rc = -EINVAL;
1326 goto out_free;
1327 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001328 if (unlikely(data[(*packet_size)++] != 0x04)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001329 printk(KERN_WARNING "Unknown version number [%d]\n",
1330 data[(*packet_size) - 1]);
Michael Halcrow237fead2006-10-04 02:16:22 -07001331 rc = -EINVAL;
1332 goto out_free;
1333 }
Tyler Hicksb0105ea2009-08-11 00:36:32 -05001334 rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher,
1335 (u16)data[(*packet_size)]);
1336 if (rc)
1337 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07001338 /* A little extra work to differentiate among the AES key
1339 * sizes; see RFC2440 */
1340 switch(data[(*packet_size)++]) {
1341 case RFC2440_CIPHER_AES_192:
1342 crypt_stat->key_size = 24;
1343 break;
1344 default:
1345 crypt_stat->key_size =
1346 (*new_auth_tok)->session_key.encrypted_key_size;
1347 }
Tyler Hicksb0105ea2009-08-11 00:36:32 -05001348 rc = ecryptfs_init_crypt_ctx(crypt_stat);
1349 if (rc)
1350 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07001351 if (unlikely(data[(*packet_size)++] != 0x03)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001352 printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001353 rc = -ENOSYS;
1354 goto out_free;
1355 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001356 /* TODO: finish the hash mapping */
Michael Halcrow237fead2006-10-04 02:16:22 -07001357 switch (data[(*packet_size)++]) {
1358 case 0x01: /* See RFC2440 for these numbers and their mappings */
1359 /* Choose MD5 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001360 memcpy((*new_auth_tok)->token.password.salt,
1361 &data[(*packet_size)], ECRYPTFS_SALT_SIZE);
1362 (*packet_size) += ECRYPTFS_SALT_SIZE;
Michael Halcrow237fead2006-10-04 02:16:22 -07001363 /* This conversion was taken straight from RFC2440 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001364 (*new_auth_tok)->token.password.hash_iterations =
1365 ((u32) 16 + (data[(*packet_size)] & 15))
1366 << ((data[(*packet_size)] >> 4) + 6);
1367 (*packet_size)++;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001368 /* Friendly reminder:
1369 * (*new_auth_tok)->session_key.encrypted_key_size =
1370 * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */
Michael Halcrow237fead2006-10-04 02:16:22 -07001371 memcpy((*new_auth_tok)->session_key.encrypted_key,
1372 &data[(*packet_size)],
1373 (*new_auth_tok)->session_key.encrypted_key_size);
1374 (*packet_size) +=
1375 (*new_auth_tok)->session_key.encrypted_key_size;
1376 (*new_auth_tok)->session_key.flags &=
1377 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1378 (*new_auth_tok)->session_key.flags |=
1379 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001380 (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001381 break;
1382 default:
1383 ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: "
1384 "[%d]\n", data[(*packet_size) - 1]);
1385 rc = -ENOSYS;
1386 goto out_free;
1387 }
1388 (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD;
1389 /* TODO: Parametarize; we might actually want userspace to
1390 * decrypt the session key. */
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001391 (*new_auth_tok)->session_key.flags &=
1392 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1393 (*new_auth_tok)->session_key.flags &=
1394 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
Michael Halcrow237fead2006-10-04 02:16:22 -07001395 list_add(&auth_tok_list_item->list, auth_tok_list);
1396 goto out;
1397out_free:
1398 (*new_auth_tok) = NULL;
1399 memset(auth_tok_list_item, 0,
1400 sizeof(struct ecryptfs_auth_tok_list_item));
1401 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1402 auth_tok_list_item);
1403out:
1404 if (rc)
1405 (*packet_size) = 0;
1406 return rc;
1407}
1408
1409/**
1410 * parse_tag_11_packet
1411 * @data: The raw bytes of the packet
1412 * @contents: This function writes the data contents of the literal
1413 * packet into this memory location
1414 * @max_contents_bytes: The maximum number of bytes that this function
1415 * is allowed to write into contents
1416 * @tag_11_contents_size: This function writes the size of the parsed
1417 * contents into this memory location; zero on
1418 * error
1419 * @packet_size: This function writes the size of the parsed packet
1420 * into this memory location; zero on error
1421 * @max_packet_size: maximum number of bytes to parse
1422 *
1423 * Returns zero on success; non-zero on error.
1424 */
1425static int
1426parse_tag_11_packet(unsigned char *data, unsigned char *contents,
1427 size_t max_contents_bytes, size_t *tag_11_contents_size,
1428 size_t *packet_size, size_t max_packet_size)
1429{
Michael Halcrow237fead2006-10-04 02:16:22 -07001430 size_t body_size;
1431 size_t length_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001432 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001433
1434 (*packet_size) = 0;
1435 (*tag_11_contents_size) = 0;
Michael Halcrowf6481042007-10-16 01:27:57 -07001436 /* This format is inspired by OpenPGP; see RFC 2440
1437 * packet tag 11
1438 *
1439 * Tag 11 identifier (1 byte)
1440 * Max Tag 11 packet size (max 3 bytes)
1441 * Binary format specifier (1 byte)
1442 * Filename length (1 byte)
1443 * Filename ("_CONSOLE") (8 bytes)
1444 * Modification date (4 bytes)
1445 * Literal data (arbitrary)
1446 *
1447 * We need at least 16 bytes of data for the packet to even be
1448 * valid.
Michael Halcrow237fead2006-10-04 02:16:22 -07001449 */
Michael Halcrowf6481042007-10-16 01:27:57 -07001450 if (max_packet_size < 16) {
1451 printk(KERN_ERR "Maximum packet size too small\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001452 rc = -EINVAL;
1453 goto out;
1454 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001455 if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001456 printk(KERN_WARNING "Invalid tag 11 packet format\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001457 rc = -EINVAL;
1458 goto out;
1459 }
Michael Halcrowf66e8832008-04-29 00:59:51 -07001460 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1461 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001462 if (rc) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001463 printk(KERN_WARNING "Invalid tag 11 packet format\n");
1464 goto out;
1465 }
1466 if (body_size < 14) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001467 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrowf6481042007-10-16 01:27:57 -07001468 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07001469 goto out;
1470 }
1471 (*packet_size) += length_size;
Michael Halcrowf6481042007-10-16 01:27:57 -07001472 (*tag_11_contents_size) = (body_size - 14);
Michael Halcrow237fead2006-10-04 02:16:22 -07001473 if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001474 printk(KERN_ERR "Packet size exceeds max\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001475 rc = -EINVAL;
1476 goto out;
1477 }
Tyler Hicks6352a292009-07-28 13:57:01 -05001478 if (unlikely((*tag_11_contents_size) > max_contents_bytes)) {
1479 printk(KERN_ERR "Literal data section in tag 11 packet exceeds "
1480 "expected size\n");
1481 rc = -EINVAL;
1482 goto out;
1483 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001484 if (data[(*packet_size)++] != 0x62) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001485 printk(KERN_WARNING "Unrecognizable packet\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001486 rc = -EINVAL;
1487 goto out;
1488 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001489 if (data[(*packet_size)++] != 0x08) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001490 printk(KERN_WARNING "Unrecognizable packet\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001491 rc = -EINVAL;
1492 goto out;
1493 }
Michael Halcrowf6481042007-10-16 01:27:57 -07001494 (*packet_size) += 12; /* Ignore filename and modification date */
Michael Halcrow237fead2006-10-04 02:16:22 -07001495 memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size));
1496 (*packet_size) += (*tag_11_contents_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001497out:
1498 if (rc) {
1499 (*packet_size) = 0;
1500 (*tag_11_contents_size) = 0;
1501 }
1502 return rc;
1503}
1504
1505/**
Michael Halcrowf4aad162007-10-16 01:27:53 -07001506 * ecryptfs_verify_version
1507 * @version: The version number to confirm
1508 *
1509 * Returns zero on good version; non-zero otherwise
1510 */
1511static int ecryptfs_verify_version(u16 version)
1512{
1513 int rc = 0;
1514 unsigned char major;
1515 unsigned char minor;
1516
1517 major = ((version >> 8) & 0xFF);
1518 minor = (version & 0xFF);
1519 if (major != ECRYPTFS_VERSION_MAJOR) {
1520 ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
1521 "Expected [%d]; got [%d]\n",
1522 ECRYPTFS_VERSION_MAJOR, major);
1523 rc = -EINVAL;
1524 goto out;
1525 }
1526 if (minor != ECRYPTFS_VERSION_MINOR) {
1527 ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
1528 "Expected [%d]; got [%d]\n",
1529 ECRYPTFS_VERSION_MINOR, minor);
1530 rc = -EINVAL;
1531 goto out;
1532 }
1533out:
1534 return rc;
1535}
1536
1537int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
1538 struct ecryptfs_auth_tok **auth_tok,
1539 char *sig)
1540{
1541 int rc = 0;
1542
1543 (*auth_tok_key) = request_key(&key_type_user, sig, NULL);
1544 if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
1545 printk(KERN_ERR "Could not find key with description: [%s]\n",
1546 sig);
Eric Sandeen982363c2008-07-23 21:30:04 -07001547 rc = process_request_key_err(PTR_ERR(*auth_tok_key));
Michael Halcrowf4aad162007-10-16 01:27:53 -07001548 goto out;
1549 }
1550 (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key);
1551 if (ecryptfs_verify_version((*auth_tok)->version)) {
1552 printk(KERN_ERR
1553 "Data structure version mismatch. "
1554 "Userspace tools must match eCryptfs "
1555 "kernel module with major version [%d] "
1556 "and minor version [%d]\n",
1557 ECRYPTFS_VERSION_MAJOR,
1558 ECRYPTFS_VERSION_MINOR);
1559 rc = -EINVAL;
1560 goto out;
1561 }
1562 if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
1563 && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
1564 printk(KERN_ERR "Invalid auth_tok structure "
1565 "returned from key query\n");
1566 rc = -EINVAL;
1567 goto out;
1568 }
1569out:
1570 return rc;
1571}
1572
1573/**
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001574 * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok.
1575 * @auth_tok: The passphrase authentication token to use to encrypt the FEK
1576 * @crypt_stat: The cryptographic context
Michael Halcrow237fead2006-10-04 02:16:22 -07001577 *
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001578 * Returns zero on success; non-zero error otherwise
Michael Halcrow237fead2006-10-04 02:16:22 -07001579 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07001580static int
1581decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1582 struct ecryptfs_crypt_stat *crypt_stat)
Michael Halcrow237fead2006-10-04 02:16:22 -07001583{
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001584 struct scatterlist dst_sg[2];
1585 struct scatterlist src_sg[2];
Michael Halcrowdd8e2902007-10-16 01:28:03 -07001586 struct mutex *tfm_mutex;
Michael Halcrow8bba0662006-10-30 22:07:18 -08001587 struct blkcipher_desc desc = {
1588 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
1589 };
1590 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001591
Michael Halcrowf4aad162007-10-16 01:27:53 -07001592 if (unlikely(ecryptfs_verbosity > 0)) {
1593 ecryptfs_printk(
1594 KERN_DEBUG, "Session key encryption key (size [%d]):\n",
1595 auth_tok->token.password.session_key_encryption_key_bytes);
1596 ecryptfs_dump_hex(
1597 auth_tok->token.password.session_key_encryption_key,
1598 auth_tok->token.password.session_key_encryption_key_bytes);
Michael Halcrow237fead2006-10-04 02:16:22 -07001599 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001600 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
1601 crypt_stat->cipher);
1602 if (unlikely(rc)) {
1603 printk(KERN_ERR "Internal error whilst attempting to get "
1604 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1605 crypt_stat->cipher, rc);
1606 goto out;
1607 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07001608 rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
1609 auth_tok->session_key.encrypted_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001610 src_sg, 2);
1611 if (rc < 1 || rc > 2) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001612 printk(KERN_ERR "Internal error whilst attempting to convert "
1613 "auth_tok->session_key.encrypted_key to scatterlist; "
1614 "expected rc = 1; got rc = [%d]. "
1615 "auth_tok->session_key.encrypted_key_size = [%d]\n", rc,
1616 auth_tok->session_key.encrypted_key_size);
1617 goto out;
1618 }
1619 auth_tok->session_key.decrypted_key_size =
1620 auth_tok->session_key.encrypted_key_size;
Michael Halcrow5dda6992007-10-16 01:28:06 -07001621 rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key,
1622 auth_tok->session_key.decrypted_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001623 dst_sg, 2);
1624 if (rc < 1 || rc > 2) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001625 printk(KERN_ERR "Internal error whilst attempting to convert "
1626 "auth_tok->session_key.decrypted_key to scatterlist; "
1627 "expected rc = 1; got rc = [%d]\n", rc);
1628 goto out;
1629 }
1630 mutex_lock(tfm_mutex);
1631 rc = crypto_blkcipher_setkey(
1632 desc.tfm, auth_tok->token.password.session_key_encryption_key,
1633 crypt_stat->key_size);
1634 if (unlikely(rc < 0)) {
1635 mutex_unlock(tfm_mutex);
Michael Halcrowe5d9cbd2006-10-30 22:07:16 -08001636 printk(KERN_ERR "Error setting key for crypto context\n");
1637 rc = -EINVAL;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001638 goto out;
Michael Halcrowe5d9cbd2006-10-30 22:07:16 -08001639 }
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001640 rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg,
Michael Halcrow8bba0662006-10-30 22:07:18 -08001641 auth_tok->session_key.encrypted_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001642 mutex_unlock(tfm_mutex);
1643 if (unlikely(rc)) {
Michael Halcrow8bba0662006-10-30 22:07:18 -08001644 printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001645 goto out;
Michael Halcrow8bba0662006-10-30 22:07:18 -08001646 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001647 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1648 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1649 auth_tok->session_key.decrypted_key_size);
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001650 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001651 if (unlikely(ecryptfs_verbosity > 0)) {
1652 ecryptfs_printk(KERN_DEBUG, "FEK of size [%d]:\n",
1653 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001654 ecryptfs_dump_hex(crypt_stat->key,
1655 crypt_stat->key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001656 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001657out:
1658 return rc;
1659}
1660
1661/**
1662 * ecryptfs_parse_packet_set
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001663 * @crypt_stat: The cryptographic context
1664 * @src: Virtual address of region of memory containing the packets
1665 * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set
Michael Halcrow237fead2006-10-04 02:16:22 -07001666 *
1667 * Get crypt_stat to have the file's session key if the requisite key
1668 * is available to decrypt the session key.
1669 *
1670 * Returns Zero if a valid authentication token was retrieved and
1671 * processed; negative value for file not encrypted or for error
1672 * conditions.
1673 */
1674int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
1675 unsigned char *src,
1676 struct dentry *ecryptfs_dentry)
1677{
1678 size_t i = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001679 size_t found_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07001680 size_t next_packet_is_auth_tok_packet;
Michael Halcrow237fead2006-10-04 02:16:22 -07001681 struct list_head auth_tok_list;
Michael Halcrowdd8e2902007-10-16 01:28:03 -07001682 struct ecryptfs_auth_tok *matching_auth_tok;
1683 struct ecryptfs_auth_tok *candidate_auth_tok;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001684 char *candidate_auth_tok_sig;
Michael Halcrow237fead2006-10-04 02:16:22 -07001685 size_t packet_size;
1686 struct ecryptfs_auth_tok *new_auth_tok;
1687 unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE];
Michael Halcrowf4aad162007-10-16 01:27:53 -07001688 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
Michael Halcrow237fead2006-10-04 02:16:22 -07001689 size_t tag_11_contents_size;
1690 size_t tag_11_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001691 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001692
1693 INIT_LIST_HEAD(&auth_tok_list);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001694 /* Parse the header to find as many packets as we can; these will be
Michael Halcrow237fead2006-10-04 02:16:22 -07001695 * added the our &auth_tok_list */
1696 next_packet_is_auth_tok_packet = 1;
1697 while (next_packet_is_auth_tok_packet) {
1698 size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i);
1699
1700 switch (src[i]) {
1701 case ECRYPTFS_TAG_3_PACKET_TYPE:
1702 rc = parse_tag_3_packet(crypt_stat,
1703 (unsigned char *)&src[i],
1704 &auth_tok_list, &new_auth_tok,
1705 &packet_size, max_packet_size);
1706 if (rc) {
1707 ecryptfs_printk(KERN_ERR, "Error parsing "
1708 "tag 3 packet\n");
1709 rc = -EIO;
1710 goto out_wipe_list;
1711 }
1712 i += packet_size;
1713 rc = parse_tag_11_packet((unsigned char *)&src[i],
1714 sig_tmp_space,
1715 ECRYPTFS_SIG_SIZE,
1716 &tag_11_contents_size,
1717 &tag_11_packet_size,
1718 max_packet_size);
1719 if (rc) {
1720 ecryptfs_printk(KERN_ERR, "No valid "
1721 "(ecryptfs-specific) literal "
1722 "packet containing "
1723 "authentication token "
1724 "signature found after "
1725 "tag 3 packet\n");
1726 rc = -EIO;
1727 goto out_wipe_list;
1728 }
1729 i += tag_11_packet_size;
1730 if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) {
1731 ecryptfs_printk(KERN_ERR, "Expected "
1732 "signature of size [%d]; "
1733 "read size [%d]\n",
1734 ECRYPTFS_SIG_SIZE,
1735 tag_11_contents_size);
1736 rc = -EIO;
1737 goto out_wipe_list;
1738 }
1739 ecryptfs_to_hex(new_auth_tok->token.password.signature,
1740 sig_tmp_space, tag_11_contents_size);
1741 new_auth_tok->token.password.signature[
1742 ECRYPTFS_PASSWORD_SIG_SIZE] = '\0';
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001743 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
Michael Halcrow237fead2006-10-04 02:16:22 -07001744 break;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001745 case ECRYPTFS_TAG_1_PACKET_TYPE:
1746 rc = parse_tag_1_packet(crypt_stat,
1747 (unsigned char *)&src[i],
1748 &auth_tok_list, &new_auth_tok,
1749 &packet_size, max_packet_size);
1750 if (rc) {
1751 ecryptfs_printk(KERN_ERR, "Error parsing "
1752 "tag 1 packet\n");
1753 rc = -EIO;
1754 goto out_wipe_list;
1755 }
1756 i += packet_size;
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001757 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001758 break;
Michael Halcrow237fead2006-10-04 02:16:22 -07001759 case ECRYPTFS_TAG_11_PACKET_TYPE:
1760 ecryptfs_printk(KERN_WARNING, "Invalid packet set "
1761 "(Tag 11 not allowed by itself)\n");
1762 rc = -EIO;
1763 goto out_wipe_list;
1764 break;
1765 default:
1766 ecryptfs_printk(KERN_DEBUG, "No packet at offset "
1767 "[%d] of the file header; hex value of "
1768 "character is [0x%.2x]\n", i, src[i]);
1769 next_packet_is_auth_tok_packet = 0;
1770 }
1771 }
1772 if (list_empty(&auth_tok_list)) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001773 printk(KERN_ERR "The lower file appears to be a non-encrypted "
1774 "eCryptfs file; this is not supported in this version "
1775 "of the eCryptfs kernel module\n");
1776 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07001777 goto out;
1778 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001779 /* auth_tok_list contains the set of authentication tokens
1780 * parsed from the metadata. We need to find a matching
1781 * authentication token that has the secret component(s)
1782 * necessary to decrypt the EFEK in the auth_tok parsed from
1783 * the metadata. There may be several potential matches, but
1784 * just one will be sufficient to decrypt to get the FEK. */
1785find_next_matching_auth_tok:
1786 found_auth_tok = 0;
1787 list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001788 candidate_auth_tok = &auth_tok_list_item->auth_tok;
1789 if (unlikely(ecryptfs_verbosity > 0)) {
1790 ecryptfs_printk(KERN_DEBUG,
1791 "Considering cadidate auth tok:\n");
1792 ecryptfs_dump_auth_tok(candidate_auth_tok);
1793 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07001794 rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig,
1795 candidate_auth_tok);
1796 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001797 printk(KERN_ERR
1798 "Unrecognized candidate auth tok type: [%d]\n",
1799 candidate_auth_tok->token_type);
1800 rc = -EINVAL;
1801 goto out_wipe_list;
1802 }
Michael Halcrow9c79f342009-01-06 14:41:57 -08001803 ecryptfs_find_auth_tok_for_sig(&matching_auth_tok,
1804 crypt_stat->mount_crypt_stat,
Michael Halcrow5dda6992007-10-16 01:28:06 -07001805 candidate_auth_tok_sig);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001806 if (matching_auth_tok) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001807 found_auth_tok = 1;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001808 goto found_matching_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07001809 }
1810 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001811 if (!found_auth_tok) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001812 ecryptfs_printk(KERN_ERR, "Could not find a usable "
1813 "authentication token\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001814 rc = -EIO;
1815 goto out_wipe_list;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001816 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001817found_matching_auth_tok:
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001818 if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
Michael Halcrowdddfa462007-02-12 00:53:44 -08001819 memcpy(&(candidate_auth_tok->token.private_key),
Michael Halcrowf4aad162007-10-16 01:27:53 -07001820 &(matching_auth_tok->token.private_key),
Michael Halcrowdddfa462007-02-12 00:53:44 -08001821 sizeof(struct ecryptfs_private_key));
Michael Halcrowf4aad162007-10-16 01:27:53 -07001822 rc = decrypt_pki_encrypted_session_key(candidate_auth_tok,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001823 crypt_stat);
1824 } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001825 memcpy(&(candidate_auth_tok->token.password),
Michael Halcrowf4aad162007-10-16 01:27:53 -07001826 &(matching_auth_tok->token.password),
Michael Halcrow237fead2006-10-04 02:16:22 -07001827 sizeof(struct ecryptfs_password));
Michael Halcrowf4aad162007-10-16 01:27:53 -07001828 rc = decrypt_passphrase_encrypted_session_key(
1829 candidate_auth_tok, crypt_stat);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001830 }
1831 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001832 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1833
1834 ecryptfs_printk(KERN_WARNING, "Error decrypting the "
1835 "session key for authentication token with sig "
1836 "[%.*s]; rc = [%d]. Removing auth tok "
1837 "candidate from the list and searching for "
1838 "the next match.\n", candidate_auth_tok_sig,
1839 ECRYPTFS_SIG_SIZE_HEX, rc);
1840 list_for_each_entry_safe(auth_tok_list_item,
1841 auth_tok_list_item_tmp,
1842 &auth_tok_list, list) {
1843 if (candidate_auth_tok
1844 == &auth_tok_list_item->auth_tok) {
1845 list_del(&auth_tok_list_item->list);
1846 kmem_cache_free(
1847 ecryptfs_auth_tok_list_item_cache,
1848 auth_tok_list_item);
1849 goto find_next_matching_auth_tok;
1850 }
1851 }
1852 BUG();
Michael Halcrowdddfa462007-02-12 00:53:44 -08001853 }
1854 rc = ecryptfs_compute_root_iv(crypt_stat);
1855 if (rc) {
1856 ecryptfs_printk(KERN_ERR, "Error computing "
1857 "the root IV\n");
1858 goto out_wipe_list;
Michael Halcrow237fead2006-10-04 02:16:22 -07001859 }
1860 rc = ecryptfs_init_crypt_ctx(crypt_stat);
1861 if (rc) {
1862 ecryptfs_printk(KERN_ERR, "Error initializing crypto "
1863 "context for cipher [%s]; rc = [%d]\n",
1864 crypt_stat->cipher, rc);
1865 }
1866out_wipe_list:
1867 wipe_auth_tok_list(&auth_tok_list);
1868out:
1869 return rc;
1870}
Michael Halcrowf4aad162007-10-16 01:27:53 -07001871
Michael Halcrowdddfa462007-02-12 00:53:44 -08001872static int
1873pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
1874 struct ecryptfs_crypt_stat *crypt_stat,
1875 struct ecryptfs_key_record *key_rec)
1876{
1877 struct ecryptfs_msg_ctx *msg_ctx = NULL;
Tyler Hicks624ae522008-10-15 22:02:51 -07001878 char *payload = NULL;
1879 size_t payload_len;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001880 struct ecryptfs_message *msg;
1881 int rc;
1882
1883 rc = write_tag_66_packet(auth_tok->token.private_key.signature,
Michael Halcrow9c79f342009-01-06 14:41:57 -08001884 ecryptfs_code_for_cipher_string(
1885 crypt_stat->cipher,
1886 crypt_stat->key_size),
Tyler Hicks624ae522008-10-15 22:02:51 -07001887 crypt_stat, &payload, &payload_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001888 if (rc) {
1889 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
1890 goto out;
1891 }
Tyler Hicks624ae522008-10-15 22:02:51 -07001892 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001893 if (rc) {
Tyler Hicks624ae522008-10-15 22:02:51 -07001894 ecryptfs_printk(KERN_ERR, "Error sending message to "
1895 "ecryptfsd\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001896 goto out;
1897 }
1898 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1899 if (rc) {
1900 ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet "
1901 "from the user space daemon\n");
1902 rc = -EIO;
1903 goto out;
1904 }
1905 rc = parse_tag_67_packet(key_rec, msg);
1906 if (rc)
1907 ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n");
1908 kfree(msg);
1909out:
Tyler Hicks624ae522008-10-15 22:02:51 -07001910 kfree(payload);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001911 return rc;
1912}
1913/**
1914 * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet
1915 * @dest: Buffer into which to write the packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001916 * @remaining_bytes: Maximum number of bytes that can be writtn
1917 * @auth_tok: The authentication token used for generating the tag 1 packet
1918 * @crypt_stat: The cryptographic context
1919 * @key_rec: The key record struct for the tag 1 packet
Michael Halcrowdddfa462007-02-12 00:53:44 -08001920 * @packet_size: This function will write the number of bytes that end
1921 * up constituting the packet; set to zero on error
1922 *
1923 * Returns zero on success; non-zero on error.
1924 */
1925static int
Michael Halcrowf4aad162007-10-16 01:27:53 -07001926write_tag_1_packet(char *dest, size_t *remaining_bytes,
1927 struct ecryptfs_auth_tok *auth_tok,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001928 struct ecryptfs_crypt_stat *crypt_stat,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001929 struct ecryptfs_key_record *key_rec, size_t *packet_size)
1930{
1931 size_t i;
1932 size_t encrypted_session_key_valid = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001933 size_t packet_size_length;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001934 size_t max_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001935 int rc = 0;
1936
1937 (*packet_size) = 0;
1938 ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature,
1939 ECRYPTFS_SIG_SIZE);
1940 encrypted_session_key_valid = 0;
1941 for (i = 0; i < crypt_stat->key_size; i++)
1942 encrypted_session_key_valid |=
1943 auth_tok->session_key.encrypted_key[i];
1944 if (encrypted_session_key_valid) {
1945 memcpy(key_rec->enc_key,
1946 auth_tok->session_key.encrypted_key,
1947 auth_tok->session_key.encrypted_key_size);
1948 goto encrypted_session_key_set;
1949 }
1950 if (auth_tok->session_key.encrypted_key_size == 0)
1951 auth_tok->session_key.encrypted_key_size =
1952 auth_tok->token.private_key.key_size;
1953 rc = pki_encrypt_session_key(auth_tok, crypt_stat, key_rec);
1954 if (rc) {
Michael Halcrowf66e8832008-04-29 00:59:51 -07001955 printk(KERN_ERR "Failed to encrypt session key via a key "
1956 "module; rc = [%d]\n", rc);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001957 goto out;
1958 }
1959 if (ecryptfs_verbosity > 0) {
1960 ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n");
1961 ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size);
1962 }
1963encrypted_session_key_set:
Michael Halcrowf4aad162007-10-16 01:27:53 -07001964 /* This format is inspired by OpenPGP; see RFC 2440
1965 * packet tag 1 */
1966 max_packet_size = (1 /* Tag 1 identifier */
1967 + 3 /* Max Tag 1 packet size */
1968 + 1 /* Version */
1969 + ECRYPTFS_SIG_SIZE /* Key identifier */
1970 + 1 /* Cipher identifier */
1971 + key_rec->enc_key_size); /* Encrypted key size */
1972 if (max_packet_size > (*remaining_bytes)) {
1973 printk(KERN_ERR "Packet length larger than maximum allowable; "
Andrew Morton81acbcd2007-10-16 01:27:59 -07001974 "need up to [%td] bytes, but there are only [%td] "
Michael Halcrowf4aad162007-10-16 01:27:53 -07001975 "available\n", max_packet_size, (*remaining_bytes));
Michael Halcrowdddfa462007-02-12 00:53:44 -08001976 rc = -EINVAL;
1977 goto out;
1978 }
1979 dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001980 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
1981 (max_packet_size - 4),
1982 &packet_size_length);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001983 if (rc) {
1984 ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet "
1985 "header; cannot generate packet length\n");
1986 goto out;
1987 }
1988 (*packet_size) += packet_size_length;
1989 dest[(*packet_size)++] = 0x03; /* version 3 */
1990 memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE);
1991 (*packet_size) += ECRYPTFS_SIG_SIZE;
1992 dest[(*packet_size)++] = RFC2440_CIPHER_RSA;
1993 memcpy(&dest[(*packet_size)], key_rec->enc_key,
1994 key_rec->enc_key_size);
1995 (*packet_size) += key_rec->enc_key_size;
1996out:
1997 if (rc)
1998 (*packet_size) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001999 else
2000 (*remaining_bytes) -= (*packet_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002001 return rc;
2002}
Michael Halcrow237fead2006-10-04 02:16:22 -07002003
2004/**
2005 * write_tag_11_packet
2006 * @dest: Target into which Tag 11 packet is to be written
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002007 * @remaining_bytes: Maximum packet length
Michael Halcrow237fead2006-10-04 02:16:22 -07002008 * @contents: Byte array of contents to copy in
2009 * @contents_length: Number of bytes in contents
2010 * @packet_length: Length of the Tag 11 packet written; zero on error
2011 *
2012 * Returns zero on success; non-zero on error.
2013 */
2014static int
Andrew Morton81acbcd2007-10-16 01:27:59 -07002015write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents,
Michael Halcrow146a4602007-10-16 01:27:58 -07002016 size_t contents_length, size_t *packet_length)
Michael Halcrow237fead2006-10-04 02:16:22 -07002017{
Michael Halcrow237fead2006-10-04 02:16:22 -07002018 size_t packet_size_length;
Michael Halcrow146a4602007-10-16 01:27:58 -07002019 size_t max_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002020 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002021
2022 (*packet_length) = 0;
Michael Halcrow146a4602007-10-16 01:27:58 -07002023 /* This format is inspired by OpenPGP; see RFC 2440
2024 * packet tag 11 */
2025 max_packet_size = (1 /* Tag 11 identifier */
2026 + 3 /* Max Tag 11 packet size */
2027 + 1 /* Binary format specifier */
2028 + 1 /* Filename length */
2029 + 8 /* Filename ("_CONSOLE") */
2030 + 4 /* Modification date */
2031 + contents_length); /* Literal data */
2032 if (max_packet_size > (*remaining_bytes)) {
2033 printk(KERN_ERR "Packet length larger than maximum allowable; "
Andrew Morton81acbcd2007-10-16 01:27:59 -07002034 "need up to [%td] bytes, but there are only [%td] "
Michael Halcrow146a4602007-10-16 01:27:58 -07002035 "available\n", max_packet_size, (*remaining_bytes));
Michael Halcrow237fead2006-10-04 02:16:22 -07002036 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07002037 goto out;
2038 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002039 dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -07002040 rc = ecryptfs_write_packet_length(&dest[(*packet_length)],
2041 (max_packet_size - 4),
2042 &packet_size_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002043 if (rc) {
Michael Halcrow146a4602007-10-16 01:27:58 -07002044 printk(KERN_ERR "Error generating tag 11 packet header; cannot "
2045 "generate packet length. rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002046 goto out;
2047 }
2048 (*packet_length) += packet_size_length;
Michael Halcrow146a4602007-10-16 01:27:58 -07002049 dest[(*packet_length)++] = 0x62; /* binary data format specifier */
Michael Halcrow237fead2006-10-04 02:16:22 -07002050 dest[(*packet_length)++] = 8;
2051 memcpy(&dest[(*packet_length)], "_CONSOLE", 8);
2052 (*packet_length) += 8;
Michael Halcrow237fead2006-10-04 02:16:22 -07002053 memset(&dest[(*packet_length)], 0x00, 4);
2054 (*packet_length) += 4;
Michael Halcrow237fead2006-10-04 02:16:22 -07002055 memcpy(&dest[(*packet_length)], contents, contents_length);
2056 (*packet_length) += contents_length;
2057 out:
2058 if (rc)
2059 (*packet_length) = 0;
Michael Halcrow146a4602007-10-16 01:27:58 -07002060 else
2061 (*remaining_bytes) -= (*packet_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002062 return rc;
2063}
2064
2065/**
2066 * write_tag_3_packet
2067 * @dest: Buffer into which to write the packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002068 * @remaining_bytes: Maximum number of bytes that can be written
Michael Halcrow237fead2006-10-04 02:16:22 -07002069 * @auth_tok: Authentication token
2070 * @crypt_stat: The cryptographic context
2071 * @key_rec: encrypted key
2072 * @packet_size: This function will write the number of bytes that end
2073 * up constituting the packet; set to zero on error
2074 *
2075 * Returns zero on success; non-zero on error.
2076 */
2077static int
Michael Halcrowf4aad162007-10-16 01:27:53 -07002078write_tag_3_packet(char *dest, size_t *remaining_bytes,
2079 struct ecryptfs_auth_tok *auth_tok,
Michael Halcrow237fead2006-10-04 02:16:22 -07002080 struct ecryptfs_crypt_stat *crypt_stat,
2081 struct ecryptfs_key_record *key_rec, size_t *packet_size)
2082{
Michael Halcrow237fead2006-10-04 02:16:22 -07002083 size_t i;
Michael Halcrow237fead2006-10-04 02:16:22 -07002084 size_t encrypted_session_key_valid = 0;
2085 char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002086 struct scatterlist dst_sg[2];
2087 struct scatterlist src_sg[2];
Michael Halcrow237fead2006-10-04 02:16:22 -07002088 struct mutex *tfm_mutex = NULL;
Trevor Highland19e66a62008-02-06 01:38:36 -08002089 u8 cipher_code;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002090 size_t packet_size_length;
2091 size_t max_packet_size;
2092 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2093 crypt_stat->mount_crypt_stat;
Michael Halcrow8bba0662006-10-30 22:07:18 -08002094 struct blkcipher_desc desc = {
2095 .tfm = NULL,
2096 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
2097 };
2098 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002099
2100 (*packet_size) = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002101 ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
Michael Halcrow237fead2006-10-04 02:16:22 -07002102 ECRYPTFS_SIG_SIZE);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002103 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
2104 crypt_stat->cipher);
2105 if (unlikely(rc)) {
2106 printk(KERN_ERR "Internal error whilst attempting to get "
2107 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
2108 crypt_stat->cipher, rc);
2109 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -07002110 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002111 if (mount_crypt_stat->global_default_cipher_key_size == 0) {
2112 struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm);
2113
2114 printk(KERN_WARNING "No key size specified at mount; "
2115 "defaulting to [%d]\n", alg->max_keysize);
2116 mount_crypt_stat->global_default_cipher_key_size =
2117 alg->max_keysize;
2118 }
2119 if (crypt_stat->key_size == 0)
2120 crypt_stat->key_size =
2121 mount_crypt_stat->global_default_cipher_key_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07002122 if (auth_tok->session_key.encrypted_key_size == 0)
2123 auth_tok->session_key.encrypted_key_size =
2124 crypt_stat->key_size;
2125 if (crypt_stat->key_size == 24
2126 && strcmp("aes", crypt_stat->cipher) == 0) {
2127 memset((crypt_stat->key + 24), 0, 8);
2128 auth_tok->session_key.encrypted_key_size = 32;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002129 } else
2130 auth_tok->session_key.encrypted_key_size = crypt_stat->key_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002131 key_rec->enc_key_size =
Michael Halcrow237fead2006-10-04 02:16:22 -07002132 auth_tok->session_key.encrypted_key_size;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002133 encrypted_session_key_valid = 0;
2134 for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++)
2135 encrypted_session_key_valid |=
2136 auth_tok->session_key.encrypted_key[i];
2137 if (encrypted_session_key_valid) {
2138 ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; "
2139 "using auth_tok->session_key.encrypted_key, "
2140 "where key_rec->enc_key_size = [%d]\n",
2141 key_rec->enc_key_size);
2142 memcpy(key_rec->enc_key,
2143 auth_tok->session_key.encrypted_key,
2144 key_rec->enc_key_size);
2145 goto encrypted_session_key_set;
2146 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08002147 if (auth_tok->token.password.flags &
2148 ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002149 ecryptfs_printk(KERN_DEBUG, "Using previously generated "
2150 "session key encryption key of size [%d]\n",
2151 auth_tok->token.password.
2152 session_key_encryption_key_bytes);
2153 memcpy(session_key_encryption_key,
2154 auth_tok->token.password.session_key_encryption_key,
2155 crypt_stat->key_size);
2156 ecryptfs_printk(KERN_DEBUG,
2157 "Cached session key " "encryption key: \n");
2158 if (ecryptfs_verbosity > 0)
2159 ecryptfs_dump_hex(session_key_encryption_key, 16);
2160 }
2161 if (unlikely(ecryptfs_verbosity > 0)) {
2162 ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n");
2163 ecryptfs_dump_hex(session_key_encryption_key, 16);
2164 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07002165 rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002166 src_sg, 2);
2167 if (rc < 1 || rc > 2) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002168 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
Michael Halcrowf4aad162007-10-16 01:27:53 -07002169 "for crypt_stat session key; expected rc = 1; "
2170 "got rc = [%d]. key_rec->enc_key_size = [%d]\n",
2171 rc, key_rec->enc_key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002172 rc = -ENOMEM;
2173 goto out;
2174 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07002175 rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002176 dst_sg, 2);
2177 if (rc < 1 || rc > 2) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002178 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
Michael Halcrowf4aad162007-10-16 01:27:53 -07002179 "for crypt_stat encrypted session key; "
2180 "expected rc = 1; got rc = [%d]. "
2181 "key_rec->enc_key_size = [%d]\n", rc,
2182 key_rec->enc_key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002183 rc = -ENOMEM;
2184 goto out;
2185 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002186 mutex_lock(tfm_mutex);
Michael Halcrow8bba0662006-10-30 22:07:18 -08002187 rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key,
2188 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002189 if (rc < 0) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002190 mutex_unlock(tfm_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -07002191 ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
Michael Halcrow8bba0662006-10-30 22:07:18 -08002192 "context; rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002193 goto out;
2194 }
2195 rc = 0;
2196 ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n",
2197 crypt_stat->key_size);
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002198 rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg,
Michael Halcrow8bba0662006-10-30 22:07:18 -08002199 (*key_rec).enc_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002200 mutex_unlock(tfm_mutex);
Michael Halcrow8bba0662006-10-30 22:07:18 -08002201 if (rc) {
2202 printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc);
2203 goto out;
2204 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002205 ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
Michael Halcrowf4aad162007-10-16 01:27:53 -07002206 if (ecryptfs_verbosity > 0) {
2207 ecryptfs_printk(KERN_DEBUG, "EFEK of size [%d]:\n",
2208 key_rec->enc_key_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002209 ecryptfs_dump_hex(key_rec->enc_key,
2210 key_rec->enc_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002211 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002212encrypted_session_key_set:
Michael Halcrow237fead2006-10-04 02:16:22 -07002213 /* This format is inspired by OpenPGP; see RFC 2440
2214 * packet tag 3 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002215 max_packet_size = (1 /* Tag 3 identifier */
2216 + 3 /* Max Tag 3 packet size */
2217 + 1 /* Version */
2218 + 1 /* Cipher code */
2219 + 1 /* S2K specifier */
2220 + 1 /* Hash identifier */
2221 + ECRYPTFS_SALT_SIZE /* Salt */
2222 + 1 /* Hash iterations */
2223 + key_rec->enc_key_size); /* Encrypted key size */
2224 if (max_packet_size > (*remaining_bytes)) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07002225 printk(KERN_ERR "Packet too large; need up to [%td] bytes, but "
2226 "there are only [%td] available\n", max_packet_size,
Michael Halcrowf4aad162007-10-16 01:27:53 -07002227 (*remaining_bytes));
2228 rc = -EINVAL;
2229 goto out;
2230 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002231 dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002232 /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3)
2233 * to get the number of octets in the actual Tag 3 packet */
Michael Halcrowf66e8832008-04-29 00:59:51 -07002234 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
2235 (max_packet_size - 4),
2236 &packet_size_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002237 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002238 printk(KERN_ERR "Error generating tag 3 packet header; cannot "
2239 "generate packet length. rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002240 goto out;
2241 }
2242 (*packet_size) += packet_size_length;
2243 dest[(*packet_size)++] = 0x04; /* version 4 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002244 /* TODO: Break from RFC2440 so that arbitrary ciphers can be
2245 * specified with strings */
Michael Halcrow9c79f342009-01-06 14:41:57 -08002246 cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher,
2247 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002248 if (cipher_code == 0) {
2249 ecryptfs_printk(KERN_WARNING, "Unable to generate code for "
2250 "cipher [%s]\n", crypt_stat->cipher);
2251 rc = -EINVAL;
2252 goto out;
2253 }
2254 dest[(*packet_size)++] = cipher_code;
2255 dest[(*packet_size)++] = 0x03; /* S2K */
2256 dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */
2257 memcpy(&dest[(*packet_size)], auth_tok->token.password.salt,
2258 ECRYPTFS_SALT_SIZE);
2259 (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */
2260 dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */
Michael Halcrowdddfa462007-02-12 00:53:44 -08002261 memcpy(&dest[(*packet_size)], key_rec->enc_key,
2262 key_rec->enc_key_size);
2263 (*packet_size) += key_rec->enc_key_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07002264out:
Michael Halcrow237fead2006-10-04 02:16:22 -07002265 if (rc)
2266 (*packet_size) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002267 else
2268 (*remaining_bytes) -= (*packet_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002269 return rc;
2270}
2271
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002272struct kmem_cache *ecryptfs_key_record_cache;
2273
Michael Halcrow237fead2006-10-04 02:16:22 -07002274/**
2275 * ecryptfs_generate_key_packet_set
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002276 * @dest_base: Virtual address from which to write the key record set
Michael Halcrow237fead2006-10-04 02:16:22 -07002277 * @crypt_stat: The cryptographic context from which the
2278 * authentication tokens will be retrieved
2279 * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat
2280 * for the global parameters
2281 * @len: The amount written
2282 * @max: The maximum amount of data allowed to be written
2283 *
2284 * Generates a key packet set and writes it to the virtual address
2285 * passed in.
2286 *
2287 * Returns zero on success; non-zero on error.
2288 */
2289int
2290ecryptfs_generate_key_packet_set(char *dest_base,
2291 struct ecryptfs_crypt_stat *crypt_stat,
2292 struct dentry *ecryptfs_dentry, size_t *len,
2293 size_t max)
2294{
Michael Halcrow237fead2006-10-04 02:16:22 -07002295 struct ecryptfs_auth_tok *auth_tok;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002296 struct ecryptfs_global_auth_tok *global_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07002297 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2298 &ecryptfs_superblock_to_private(
2299 ecryptfs_dentry->d_sb)->mount_crypt_stat;
2300 size_t written;
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002301 struct ecryptfs_key_record *key_rec;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002302 struct ecryptfs_key_sig *key_sig;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002303 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002304
2305 (*len) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002306 mutex_lock(&crypt_stat->keysig_list_mutex);
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002307 key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL);
2308 if (!key_rec) {
2309 rc = -ENOMEM;
2310 goto out;
2311 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002312 list_for_each_entry(key_sig, &crypt_stat->keysig_list,
2313 crypt_stat_list) {
2314 memset(key_rec, 0, sizeof(*key_rec));
2315 rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
2316 mount_crypt_stat,
2317 key_sig->keysig);
2318 if (rc) {
2319 printk(KERN_ERR "Error attempting to get the global "
2320 "auth_tok; rc = [%d]\n", rc);
2321 goto out_free;
2322 }
2323 if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) {
2324 printk(KERN_WARNING
2325 "Skipping invalid auth tok with sig = [%s]\n",
2326 global_auth_tok->sig);
2327 continue;
2328 }
2329 auth_tok = global_auth_tok->global_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07002330 if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
2331 rc = write_tag_3_packet((dest_base + (*len)),
Michael Halcrowf4aad162007-10-16 01:27:53 -07002332 &max, auth_tok,
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002333 crypt_stat, key_rec,
Michael Halcrow237fead2006-10-04 02:16:22 -07002334 &written);
2335 if (rc) {
2336 ecryptfs_printk(KERN_WARNING, "Error "
2337 "writing tag 3 packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002338 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002339 }
2340 (*len) += written;
2341 /* Write auth tok signature packet */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002342 rc = write_tag_11_packet((dest_base + (*len)), &max,
2343 key_rec->sig,
2344 ECRYPTFS_SIG_SIZE, &written);
Michael Halcrow237fead2006-10-04 02:16:22 -07002345 if (rc) {
2346 ecryptfs_printk(KERN_ERR, "Error writing "
2347 "auth tok signature packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002348 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002349 }
2350 (*len) += written;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002351 } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
2352 rc = write_tag_1_packet(dest_base + (*len),
Michael Halcrowf4aad162007-10-16 01:27:53 -07002353 &max, auth_tok,
2354 crypt_stat, key_rec, &written);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002355 if (rc) {
2356 ecryptfs_printk(KERN_WARNING, "Error "
2357 "writing tag 1 packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002358 goto out_free;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002359 }
2360 (*len) += written;
Michael Halcrow237fead2006-10-04 02:16:22 -07002361 } else {
2362 ecryptfs_printk(KERN_WARNING, "Unsupported "
2363 "authentication token type\n");
2364 rc = -EINVAL;
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002365 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002366 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002367 }
2368 if (likely(max > 0)) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002369 dest_base[(*len)] = 0x00;
2370 } else {
2371 ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n");
2372 rc = -EIO;
2373 }
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002374out_free:
2375 kmem_cache_free(ecryptfs_key_record_cache, key_rec);
Michael Halcrow237fead2006-10-04 02:16:22 -07002376out:
2377 if (rc)
2378 (*len) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002379 mutex_unlock(&crypt_stat->keysig_list_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -07002380 return rc;
2381}
Michael Halcrowf4aad162007-10-16 01:27:53 -07002382
2383struct kmem_cache *ecryptfs_key_sig_cache;
2384
2385int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig)
2386{
2387 struct ecryptfs_key_sig *new_key_sig;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002388
2389 new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL);
2390 if (!new_key_sig) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002391 printk(KERN_ERR
2392 "Error allocating from ecryptfs_key_sig_cache\n");
Roland Dreieraa061172009-07-01 15:48:18 -07002393 return -ENOMEM;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002394 }
2395 memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
Roland Dreieraa061172009-07-01 15:48:18 -07002396 /* Caller must hold keysig_list_mutex */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002397 list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
Roland Dreieraa061172009-07-01 15:48:18 -07002398
2399 return 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002400}
2401
2402struct kmem_cache *ecryptfs_global_auth_tok_cache;
2403
2404int
2405ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
Tyler Hicks84814d62009-03-13 13:51:59 -07002406 char *sig, u32 global_auth_tok_flags)
Michael Halcrowf4aad162007-10-16 01:27:53 -07002407{
2408 struct ecryptfs_global_auth_tok *new_auth_tok;
2409 int rc = 0;
2410
Eric Sandeen459e2162007-12-17 16:19:52 -08002411 new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache,
Michael Halcrowf4aad162007-10-16 01:27:53 -07002412 GFP_KERNEL);
2413 if (!new_auth_tok) {
2414 rc = -ENOMEM;
2415 printk(KERN_ERR "Error allocating from "
2416 "ecryptfs_global_auth_tok_cache\n");
2417 goto out;
2418 }
2419 memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX);
Tyler Hicks84814d62009-03-13 13:51:59 -07002420 new_auth_tok->flags = global_auth_tok_flags;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002421 new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
2422 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
2423 list_add(&new_auth_tok->mount_crypt_stat_list,
2424 &mount_crypt_stat->global_auth_tok_list);
2425 mount_crypt_stat->num_global_auth_toks++;
2426 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
2427out:
2428 return rc;
2429}
2430