blob: 89c5476506ef36c8c3de7520565b8360d70eb83b [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));
Michael Halcrow9c79f342009-01-06 14:41:57 -0800518 goto out;
519 }
520 s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
521 (*packet_size) = 0;
522 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(
523 &s->desc.tfm,
524 &s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name);
525 if (unlikely(rc)) {
526 printk(KERN_ERR "Internal error whilst attempting to get "
527 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
528 mount_crypt_stat->global_default_fn_cipher_name, rc);
529 goto out;
530 }
531 mutex_lock(s->tfm_mutex);
532 s->block_size = crypto_blkcipher_blocksize(s->desc.tfm);
533 /* Plus one for the \0 separator between the random prefix
534 * and the plaintext filename */
535 s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1);
536 s->block_aligned_filename_size = (s->num_rand_bytes + filename_size);
537 if ((s->block_aligned_filename_size % s->block_size) != 0) {
538 s->num_rand_bytes += (s->block_size
539 - (s->block_aligned_filename_size
540 % s->block_size));
541 s->block_aligned_filename_size = (s->num_rand_bytes
542 + filename_size);
543 }
544 /* Octet 0: Tag 70 identifier
545 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
546 * and block-aligned encrypted filename size)
547 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
548 * Octet N2-N3: Cipher identifier (1 octet)
549 * Octets N3-N4: Block-aligned encrypted filename
550 * - Consists of a minimum number of random characters, a \0
551 * separator, and then the filename */
552 s->max_packet_size = (1 /* Tag 70 identifier */
553 + 3 /* Max Tag 70 packet size */
554 + ECRYPTFS_SIG_SIZE /* FNEK sig */
555 + 1 /* Cipher identifier */
556 + s->block_aligned_filename_size);
557 if (dest == NULL) {
558 (*packet_size) = s->max_packet_size;
559 goto out_unlock;
560 }
561 if (s->max_packet_size > (*remaining_bytes)) {
Michael Halcrowa8f12862009-01-06 14:42:03 -0800562 printk(KERN_WARNING "%s: Require [%zd] bytes to write; only "
563 "[%zd] available\n", __func__, s->max_packet_size,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800564 (*remaining_bytes));
565 rc = -EINVAL;
566 goto out_unlock;
567 }
568 s->block_aligned_filename = kzalloc(s->block_aligned_filename_size,
569 GFP_KERNEL);
570 if (!s->block_aligned_filename) {
571 printk(KERN_ERR "%s: Out of kernel memory whilst attempting to "
Michael Halcrowdf261c52009-01-06 14:42:02 -0800572 "kzalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800573 s->block_aligned_filename_size);
574 rc = -ENOMEM;
575 goto out_unlock;
576 }
577 s->i = 0;
578 dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE;
579 rc = ecryptfs_write_packet_length(&dest[s->i],
580 (ECRYPTFS_SIG_SIZE
581 + 1 /* Cipher code */
582 + s->block_aligned_filename_size),
583 &s->packet_size_len);
584 if (rc) {
585 printk(KERN_ERR "%s: Error generating tag 70 packet "
586 "header; cannot generate packet length; rc = [%d]\n",
587 __func__, rc);
588 goto out_free_unlock;
589 }
590 s->i += s->packet_size_len;
591 ecryptfs_from_hex(&dest[s->i],
592 mount_crypt_stat->global_default_fnek_sig,
593 ECRYPTFS_SIG_SIZE);
594 s->i += ECRYPTFS_SIG_SIZE;
595 s->cipher_code = ecryptfs_code_for_cipher_string(
596 mount_crypt_stat->global_default_fn_cipher_name,
597 mount_crypt_stat->global_default_fn_cipher_key_bytes);
598 if (s->cipher_code == 0) {
599 printk(KERN_WARNING "%s: Unable to generate code for "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800600 "cipher [%s] with key bytes [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800601 mount_crypt_stat->global_default_fn_cipher_name,
602 mount_crypt_stat->global_default_fn_cipher_key_bytes);
603 rc = -EINVAL;
604 goto out_free_unlock;
605 }
606 dest[s->i++] = s->cipher_code;
607 rc = ecryptfs_find_auth_tok_for_sig(
608 &s->auth_tok, mount_crypt_stat,
609 mount_crypt_stat->global_default_fnek_sig);
610 if (rc) {
611 printk(KERN_ERR "%s: Error attempting to find auth tok for "
612 "fnek sig [%s]; rc = [%d]\n", __func__,
613 mount_crypt_stat->global_default_fnek_sig, rc);
614 goto out_free_unlock;
615 }
616 /* TODO: Support other key modules than passphrase for
617 * filename encryption */
Tyler Hicksdf6ad332009-08-21 04:27:46 -0500618 if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {
619 rc = -EOPNOTSUPP;
620 printk(KERN_INFO "%s: Filename encryption only supports "
621 "password tokens\n", __func__);
622 goto out_free_unlock;
623 }
Michael Halcrow9c79f342009-01-06 14:41:57 -0800624 sg_init_one(
625 &s->hash_sg,
626 (u8 *)s->auth_tok->token.password.session_key_encryption_key,
627 s->auth_tok->token.password.session_key_encryption_key_bytes);
628 s->hash_desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
629 s->hash_desc.tfm = crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST, 0,
630 CRYPTO_ALG_ASYNC);
631 if (IS_ERR(s->hash_desc.tfm)) {
632 rc = PTR_ERR(s->hash_desc.tfm);
633 printk(KERN_ERR "%s: Error attempting to "
634 "allocate hash crypto context; rc = [%d]\n",
635 __func__, rc);
636 goto out_free_unlock;
637 }
638 rc = crypto_hash_init(&s->hash_desc);
639 if (rc) {
640 printk(KERN_ERR
641 "%s: Error initializing crypto hash; rc = [%d]\n",
642 __func__, rc);
643 goto out_release_free_unlock;
644 }
645 rc = crypto_hash_update(
646 &s->hash_desc, &s->hash_sg,
647 s->auth_tok->token.password.session_key_encryption_key_bytes);
648 if (rc) {
649 printk(KERN_ERR
650 "%s: Error updating crypto hash; rc = [%d]\n",
651 __func__, rc);
652 goto out_release_free_unlock;
653 }
654 rc = crypto_hash_final(&s->hash_desc, s->hash);
655 if (rc) {
656 printk(KERN_ERR
657 "%s: Error finalizing crypto hash; rc = [%d]\n",
658 __func__, rc);
659 goto out_release_free_unlock;
660 }
661 for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) {
662 s->block_aligned_filename[s->j] =
663 s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)];
664 if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)
665 == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) {
666 sg_init_one(&s->hash_sg, (u8 *)s->hash,
667 ECRYPTFS_TAG_70_DIGEST_SIZE);
668 rc = crypto_hash_init(&s->hash_desc);
669 if (rc) {
670 printk(KERN_ERR
671 "%s: Error initializing crypto hash; "
672 "rc = [%d]\n", __func__, rc);
673 goto out_release_free_unlock;
674 }
675 rc = crypto_hash_update(&s->hash_desc, &s->hash_sg,
676 ECRYPTFS_TAG_70_DIGEST_SIZE);
677 if (rc) {
678 printk(KERN_ERR
679 "%s: Error updating crypto hash; "
680 "rc = [%d]\n", __func__, rc);
681 goto out_release_free_unlock;
682 }
683 rc = crypto_hash_final(&s->hash_desc, s->tmp_hash);
684 if (rc) {
685 printk(KERN_ERR
686 "%s: Error finalizing crypto hash; "
687 "rc = [%d]\n", __func__, rc);
688 goto out_release_free_unlock;
689 }
690 memcpy(s->hash, s->tmp_hash,
691 ECRYPTFS_TAG_70_DIGEST_SIZE);
692 }
693 if (s->block_aligned_filename[s->j] == '\0')
694 s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL;
695 }
696 memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename,
697 filename_size);
698 rc = virt_to_scatterlist(s->block_aligned_filename,
699 s->block_aligned_filename_size, &s->src_sg, 1);
700 if (rc != 1) {
701 printk(KERN_ERR "%s: Internal error whilst attempting to "
702 "convert filename memory to scatterlist; "
703 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800704 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800705 s->block_aligned_filename_size);
706 goto out_release_free_unlock;
707 }
708 rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size,
709 &s->dst_sg, 1);
710 if (rc != 1) {
711 printk(KERN_ERR "%s: Internal error whilst attempting to "
712 "convert encrypted filename memory to scatterlist; "
713 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800714 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800715 s->block_aligned_filename_size);
716 goto out_release_free_unlock;
717 }
718 /* The characters in the first block effectively do the job
719 * of the IV here, so we just use 0's for the IV. Note the
720 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
721 * >= ECRYPTFS_MAX_IV_BYTES. */
722 memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
723 s->desc.info = s->iv;
724 rc = crypto_blkcipher_setkey(
725 s->desc.tfm,
726 s->auth_tok->token.password.session_key_encryption_key,
727 mount_crypt_stat->global_default_fn_cipher_key_bytes);
728 if (rc < 0) {
729 printk(KERN_ERR "%s: Error setting key for crypto context; "
730 "rc = [%d]. s->auth_tok->token.password.session_key_"
731 "encryption_key = [0x%p]; mount_crypt_stat->"
Michael Halcrowdf261c52009-01-06 14:42:02 -0800732 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800733 rc,
734 s->auth_tok->token.password.session_key_encryption_key,
735 mount_crypt_stat->global_default_fn_cipher_key_bytes);
736 goto out_release_free_unlock;
737 }
738 rc = crypto_blkcipher_encrypt_iv(&s->desc, &s->dst_sg, &s->src_sg,
739 s->block_aligned_filename_size);
740 if (rc) {
741 printk(KERN_ERR "%s: Error attempting to encrypt filename; "
742 "rc = [%d]\n", __func__, rc);
743 goto out_release_free_unlock;
744 }
745 s->i += s->block_aligned_filename_size;
746 (*packet_size) = s->i;
747 (*remaining_bytes) -= (*packet_size);
748out_release_free_unlock:
749 crypto_free_hash(s->hash_desc.tfm);
750out_free_unlock:
Johannes Weiner00fcf2c2009-03-31 15:24:42 -0700751 kzfree(s->block_aligned_filename);
Michael Halcrow9c79f342009-01-06 14:41:57 -0800752out_unlock:
753 mutex_unlock(s->tfm_mutex);
754out:
755 kfree(s);
756 return rc;
757}
758
759struct ecryptfs_parse_tag_70_packet_silly_stack {
760 u8 cipher_code;
761 size_t max_packet_size;
762 size_t packet_size_len;
763 size_t parsed_tag_70_packet_size;
764 size_t block_aligned_filename_size;
765 size_t block_size;
766 size_t i;
767 struct mutex *tfm_mutex;
768 char *decrypted_filename;
769 struct ecryptfs_auth_tok *auth_tok;
770 struct scatterlist src_sg;
771 struct scatterlist dst_sg;
772 struct blkcipher_desc desc;
773 char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1];
774 char iv[ECRYPTFS_MAX_IV_BYTES];
775 char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE];
776};
777
778/**
779 * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet
780 * @filename: This function kmalloc's the memory for the filename
Michael Halcrow7d8bc2b2009-01-06 14:42:04 -0800781 * @filename_size: This function sets this to the amount of memory
782 * kmalloc'd for the filename
783 * @packet_size: This function sets this to the the number of octets
784 * in the packet parsed
785 * @mount_crypt_stat: The mount-wide cryptographic context
786 * @data: The memory location containing the start of the tag 70
787 * packet
788 * @max_packet_size: The maximum legal size of the packet to be parsed
789 * from @data
790 *
791 * Returns zero on success; non-zero otherwise
Michael Halcrow9c79f342009-01-06 14:41:57 -0800792 */
793int
794ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
795 size_t *packet_size,
796 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
797 char *data, size_t max_packet_size)
798{
799 struct ecryptfs_parse_tag_70_packet_silly_stack *s;
800 int rc = 0;
801
802 (*packet_size) = 0;
803 (*filename_size) = 0;
804 (*filename) = NULL;
805 s = kmalloc(sizeof(*s), GFP_KERNEL);
806 if (!s) {
807 printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800808 "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
Michael Halcrow9c79f342009-01-06 14:41:57 -0800809 goto out;
810 }
811 s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
812 if (max_packet_size < (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)) {
Michael Halcrowdf261c52009-01-06 14:42:02 -0800813 printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be "
Michael Halcrow9c79f342009-01-06 14:41:57 -0800814 "at least [%d]\n", __func__, max_packet_size,
815 (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1));
816 rc = -EINVAL;
817 goto out;
818 }
819 /* Octet 0: Tag 70 identifier
820 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
821 * and block-aligned encrypted filename size)
822 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
823 * Octet N2-N3: Cipher identifier (1 octet)
824 * Octets N3-N4: Block-aligned encrypted filename
825 * - Consists of a minimum number of random numbers, a \0
826 * separator, and then the filename */
827 if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) {
828 printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be "
829 "tag [0x%.2x]\n", __func__,
830 data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE);
831 rc = -EINVAL;
832 goto out;
833 }
834 rc = ecryptfs_parse_packet_length(&data[(*packet_size)],
835 &s->parsed_tag_70_packet_size,
836 &s->packet_size_len);
837 if (rc) {
838 printk(KERN_WARNING "%s: Error parsing packet length; "
839 "rc = [%d]\n", __func__, rc);
840 goto out;
841 }
842 s->block_aligned_filename_size = (s->parsed_tag_70_packet_size
843 - ECRYPTFS_SIG_SIZE - 1);
844 if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size)
845 > max_packet_size) {
Michael Halcrowa8f12862009-01-06 14:42:03 -0800846 printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet "
847 "size is [%zd]\n", __func__, max_packet_size,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800848 (1 + s->packet_size_len + 1
849 + s->block_aligned_filename_size));
850 rc = -EINVAL;
851 goto out;
852 }
853 (*packet_size) += s->packet_size_len;
854 ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)],
855 ECRYPTFS_SIG_SIZE);
856 s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0';
857 (*packet_size) += ECRYPTFS_SIG_SIZE;
858 s->cipher_code = data[(*packet_size)++];
859 rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code);
860 if (rc) {
861 printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n",
862 __func__, s->cipher_code);
863 goto out;
864 }
865 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm,
866 &s->tfm_mutex,
867 s->cipher_string);
868 if (unlikely(rc)) {
869 printk(KERN_ERR "Internal error whilst attempting to get "
870 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
871 s->cipher_string, rc);
872 goto out;
873 }
874 mutex_lock(s->tfm_mutex);
875 rc = virt_to_scatterlist(&data[(*packet_size)],
876 s->block_aligned_filename_size, &s->src_sg, 1);
877 if (rc != 1) {
878 printk(KERN_ERR "%s: Internal error whilst attempting to "
879 "convert encrypted filename memory to scatterlist; "
880 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800881 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800882 s->block_aligned_filename_size);
883 goto out_unlock;
884 }
885 (*packet_size) += s->block_aligned_filename_size;
886 s->decrypted_filename = kmalloc(s->block_aligned_filename_size,
887 GFP_KERNEL);
888 if (!s->decrypted_filename) {
889 printk(KERN_ERR "%s: Out of memory whilst attempting to "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800890 "kmalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800891 s->block_aligned_filename_size);
892 rc = -ENOMEM;
893 goto out_unlock;
894 }
895 rc = virt_to_scatterlist(s->decrypted_filename,
896 s->block_aligned_filename_size, &s->dst_sg, 1);
897 if (rc != 1) {
898 printk(KERN_ERR "%s: Internal error whilst attempting to "
899 "convert decrypted filename memory to scatterlist; "
900 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800901 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800902 s->block_aligned_filename_size);
903 goto out_free_unlock;
904 }
905 /* The characters in the first block effectively do the job of
906 * the IV here, so we just use 0's for the IV. Note the
907 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
908 * >= ECRYPTFS_MAX_IV_BYTES. */
909 memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
910 s->desc.info = s->iv;
911 rc = ecryptfs_find_auth_tok_for_sig(&s->auth_tok, mount_crypt_stat,
912 s->fnek_sig_hex);
913 if (rc) {
914 printk(KERN_ERR "%s: Error attempting to find auth tok for "
915 "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex,
916 rc);
917 goto out_free_unlock;
918 }
919 /* TODO: Support other key modules than passphrase for
920 * filename encryption */
Tyler Hicksdf6ad332009-08-21 04:27:46 -0500921 if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {
922 rc = -EOPNOTSUPP;
923 printk(KERN_INFO "%s: Filename encryption only supports "
924 "password tokens\n", __func__);
925 goto out_free_unlock;
926 }
Michael Halcrow9c79f342009-01-06 14:41:57 -0800927 rc = crypto_blkcipher_setkey(
928 s->desc.tfm,
929 s->auth_tok->token.password.session_key_encryption_key,
930 mount_crypt_stat->global_default_fn_cipher_key_bytes);
931 if (rc < 0) {
932 printk(KERN_ERR "%s: Error setting key for crypto context; "
933 "rc = [%d]. s->auth_tok->token.password.session_key_"
934 "encryption_key = [0x%p]; mount_crypt_stat->"
Michael Halcrowdf261c52009-01-06 14:42:02 -0800935 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800936 rc,
937 s->auth_tok->token.password.session_key_encryption_key,
938 mount_crypt_stat->global_default_fn_cipher_key_bytes);
939 goto out_free_unlock;
940 }
941 rc = crypto_blkcipher_decrypt_iv(&s->desc, &s->dst_sg, &s->src_sg,
942 s->block_aligned_filename_size);
943 if (rc) {
944 printk(KERN_ERR "%s: Error attempting to decrypt filename; "
945 "rc = [%d]\n", __func__, rc);
946 goto out_free_unlock;
947 }
948 s->i = 0;
949 while (s->decrypted_filename[s->i] != '\0'
950 && s->i < s->block_aligned_filename_size)
951 s->i++;
952 if (s->i == s->block_aligned_filename_size) {
953 printk(KERN_WARNING "%s: Invalid tag 70 packet; could not "
954 "find valid separator between random characters and "
955 "the filename\n", __func__);
956 rc = -EINVAL;
957 goto out_free_unlock;
958 }
959 s->i++;
960 (*filename_size) = (s->block_aligned_filename_size - s->i);
961 if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) {
Michael Halcrowdf261c52009-01-06 14:42:02 -0800962 printk(KERN_WARNING "%s: Filename size is [%zd], which is "
Michael Halcrow9c79f342009-01-06 14:41:57 -0800963 "invalid\n", __func__, (*filename_size));
964 rc = -EINVAL;
965 goto out_free_unlock;
966 }
967 (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL);
968 if (!(*filename)) {
969 printk(KERN_ERR "%s: Out of memory whilst attempting to "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800970 "kmalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800971 ((*filename_size) + 1));
972 rc = -ENOMEM;
973 goto out_free_unlock;
974 }
975 memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size));
976 (*filename)[(*filename_size)] = '\0';
977out_free_unlock:
978 kfree(s->decrypted_filename);
979out_unlock:
980 mutex_unlock(s->tfm_mutex);
981out:
982 if (rc) {
983 (*packet_size) = 0;
984 (*filename_size) = 0;
985 (*filename) = NULL;
986 }
987 kfree(s);
988 return rc;
989}
990
991static int
Michael Halcrowcd9d67d2007-10-16 01:28:04 -0700992ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok)
993{
994 int rc = 0;
995
996 (*sig) = NULL;
997 switch (auth_tok->token_type) {
998 case ECRYPTFS_PASSWORD:
999 (*sig) = auth_tok->token.password.signature;
1000 break;
1001 case ECRYPTFS_PRIVATE_KEY:
1002 (*sig) = auth_tok->token.private_key.signature;
1003 break;
1004 default:
1005 printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n",
1006 auth_tok->token_type);
1007 rc = -EINVAL;
1008 }
1009 return rc;
1010}
1011
Michael Halcrowdddfa462007-02-12 00:53:44 -08001012/**
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001013 * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok.
1014 * @auth_tok: The key authentication token used to decrypt the session key
1015 * @crypt_stat: The cryptographic context
Michael Halcrowdddfa462007-02-12 00:53:44 -08001016 *
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001017 * Returns zero on success; non-zero error otherwise.
Michael Halcrowdddfa462007-02-12 00:53:44 -08001018 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07001019static int
1020decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1021 struct ecryptfs_crypt_stat *crypt_stat)
Michael Halcrowdddfa462007-02-12 00:53:44 -08001022{
Trevor Highland19e66a62008-02-06 01:38:36 -08001023 u8 cipher_code = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001024 struct ecryptfs_msg_ctx *msg_ctx;
1025 struct ecryptfs_message *msg = NULL;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001026 char *auth_tok_sig;
Tyler Hicks624ae522008-10-15 22:02:51 -07001027 char *payload;
1028 size_t payload_len;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001029 int rc;
1030
Michael Halcrow5dda6992007-10-16 01:28:06 -07001031 rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok);
1032 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001033 printk(KERN_ERR "Unrecognized auth tok type: [%d]\n",
1034 auth_tok->token_type);
1035 goto out;
1036 }
1037 rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key),
Tyler Hicks624ae522008-10-15 22:02:51 -07001038 &payload, &payload_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001039 if (rc) {
Michael Halcrowf66e8832008-04-29 00:59:51 -07001040 ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001041 goto out;
1042 }
Tyler Hicks624ae522008-10-15 22:02:51 -07001043 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001044 if (rc) {
Tyler Hicks624ae522008-10-15 22:02:51 -07001045 ecryptfs_printk(KERN_ERR, "Error sending message to "
1046 "ecryptfsd\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001047 goto out;
1048 }
1049 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1050 if (rc) {
1051 ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet "
1052 "from the user space daemon\n");
1053 rc = -EIO;
1054 goto out;
1055 }
1056 rc = parse_tag_65_packet(&(auth_tok->session_key),
1057 &cipher_code, msg);
1058 if (rc) {
1059 printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n",
1060 rc);
1061 goto out;
1062 }
1063 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1064 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1065 auth_tok->session_key.decrypted_key_size);
1066 crypt_stat->key_size = auth_tok->session_key.decrypted_key_size;
1067 rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code);
1068 if (rc) {
1069 ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n",
1070 cipher_code)
1071 goto out;
1072 }
1073 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1074 if (ecryptfs_verbosity > 0) {
1075 ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n");
1076 ecryptfs_dump_hex(crypt_stat->key,
1077 crypt_stat->key_size);
1078 }
1079out:
1080 if (msg)
1081 kfree(msg);
1082 return rc;
1083}
1084
1085static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
1086{
Michael Halcrowdddfa462007-02-12 00:53:44 -08001087 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
Michael Halcrowe0869cc2007-10-16 01:27:55 -07001088 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001089
Michael Halcrowe0869cc2007-10-16 01:27:55 -07001090 list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp,
1091 auth_tok_list_head, list) {
1092 list_del(&auth_tok_list_item->list);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001093 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1094 auth_tok_list_item);
1095 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001096}
1097
1098struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
1099
Michael Halcrowdddfa462007-02-12 00:53:44 -08001100/**
1101 * parse_tag_1_packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001102 * @crypt_stat: The cryptographic context to modify based on packet contents
Michael Halcrowdddfa462007-02-12 00:53:44 -08001103 * @data: The raw bytes of the packet.
1104 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001105 * a new authentication token will be placed at the
1106 * end of this list for this packet.
Michael Halcrowdddfa462007-02-12 00:53:44 -08001107 * @new_auth_tok: Pointer to a pointer to memory that this function
1108 * allocates; sets the memory address of the pointer to
1109 * NULL on error. This object is added to the
1110 * auth_tok_list.
1111 * @packet_size: This function writes the size of the parsed packet
1112 * into this memory location; zero on error.
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001113 * @max_packet_size: The maximum allowable packet size
Michael Halcrowdddfa462007-02-12 00:53:44 -08001114 *
1115 * Returns zero on success; non-zero on error.
1116 */
1117static int
1118parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
1119 unsigned char *data, struct list_head *auth_tok_list,
1120 struct ecryptfs_auth_tok **new_auth_tok,
1121 size_t *packet_size, size_t max_packet_size)
1122{
1123 size_t body_size;
1124 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1125 size_t length_size;
1126 int rc = 0;
1127
1128 (*packet_size) = 0;
1129 (*new_auth_tok) = NULL;
Michael Halcrow13218172007-10-16 01:27:56 -07001130 /**
1131 * This format is inspired by OpenPGP; see RFC 2440
1132 * packet tag 1
1133 *
1134 * Tag 1 identifier (1 byte)
1135 * Max Tag 1 packet size (max 3 bytes)
1136 * Version (1 byte)
1137 * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE)
1138 * Cipher identifier (1 byte)
1139 * Encrypted key size (arbitrary)
1140 *
1141 * 12 bytes minimum packet size
Michael Halcrowdddfa462007-02-12 00:53:44 -08001142 */
Michael Halcrow13218172007-10-16 01:27:56 -07001143 if (unlikely(max_packet_size < 12)) {
1144 printk(KERN_ERR "Invalid max packet size; must be >=12\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001145 rc = -EINVAL;
1146 goto out;
1147 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001148 if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) {
Michael Halcrow13218172007-10-16 01:27:56 -07001149 printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n",
1150 ECRYPTFS_TAG_1_PACKET_TYPE);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001151 rc = -EINVAL;
1152 goto out;
1153 }
1154 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1155 * at end of function upon failure */
1156 auth_tok_list_item =
Michael Halcrow13218172007-10-16 01:27:56 -07001157 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache,
1158 GFP_KERNEL);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001159 if (!auth_tok_list_item) {
Michael Halcrow13218172007-10-16 01:27:56 -07001160 printk(KERN_ERR "Unable to allocate memory\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001161 rc = -ENOMEM;
1162 goto out;
1163 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001164 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001165 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1166 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001167 if (rc) {
Michael Halcrow13218172007-10-16 01:27:56 -07001168 printk(KERN_WARNING "Error parsing packet length; "
1169 "rc = [%d]\n", rc);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001170 goto out_free;
1171 }
Michael Halcrow13218172007-10-16 01:27:56 -07001172 if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001173 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001174 rc = -EINVAL;
1175 goto out_free;
1176 }
1177 (*packet_size) += length_size;
1178 if (unlikely((*packet_size) + body_size > max_packet_size)) {
Michael Halcrow13218172007-10-16 01:27:56 -07001179 printk(KERN_WARNING "Packet size exceeds max\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001180 rc = -EINVAL;
1181 goto out_free;
1182 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001183 if (unlikely(data[(*packet_size)++] != 0x03)) {
Michael Halcrow13218172007-10-16 01:27:56 -07001184 printk(KERN_WARNING "Unknown version number [%d]\n",
1185 data[(*packet_size) - 1]);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001186 rc = -EINVAL;
1187 goto out_free;
1188 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001189 ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
1190 &data[(*packet_size)], ECRYPTFS_SIG_SIZE);
1191 *packet_size += ECRYPTFS_SIG_SIZE;
1192 /* This byte is skipped because the kernel does not need to
1193 * know which public key encryption algorithm was used */
1194 (*packet_size)++;
1195 (*new_auth_tok)->session_key.encrypted_key_size =
Michael Halcrow13218172007-10-16 01:27:56 -07001196 body_size - (ECRYPTFS_SIG_SIZE + 2);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001197 if ((*new_auth_tok)->session_key.encrypted_key_size
1198 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
Michael Halcrow13218172007-10-16 01:27:56 -07001199 printk(KERN_WARNING "Tag 1 packet contains key larger "
1200 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001201 rc = -EINVAL;
1202 goto out;
1203 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001204 memcpy((*new_auth_tok)->session_key.encrypted_key,
Michael Halcrow13218172007-10-16 01:27:56 -07001205 &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2)));
Michael Halcrowdddfa462007-02-12 00:53:44 -08001206 (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size;
1207 (*new_auth_tok)->session_key.flags &=
1208 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1209 (*new_auth_tok)->session_key.flags |=
1210 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
1211 (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY;
Michael Halcrow13218172007-10-16 01:27:56 -07001212 (*new_auth_tok)->flags = 0;
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001213 (*new_auth_tok)->session_key.flags &=
1214 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1215 (*new_auth_tok)->session_key.flags &=
1216 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001217 list_add(&auth_tok_list_item->list, auth_tok_list);
1218 goto out;
1219out_free:
1220 (*new_auth_tok) = NULL;
1221 memset(auth_tok_list_item, 0,
1222 sizeof(struct ecryptfs_auth_tok_list_item));
1223 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1224 auth_tok_list_item);
1225out:
1226 if (rc)
1227 (*packet_size) = 0;
1228 return rc;
1229}
1230
Michael Halcrow237fead2006-10-04 02:16:22 -07001231/**
1232 * parse_tag_3_packet
1233 * @crypt_stat: The cryptographic context to modify based on packet
1234 * contents.
1235 * @data: The raw bytes of the packet.
1236 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
1237 * a new authentication token will be placed at the end
1238 * of this list for this packet.
1239 * @new_auth_tok: Pointer to a pointer to memory that this function
1240 * allocates; sets the memory address of the pointer to
1241 * NULL on error. This object is added to the
1242 * auth_tok_list.
1243 * @packet_size: This function writes the size of the parsed packet
1244 * into this memory location; zero on error.
1245 * @max_packet_size: maximum number of bytes to parse
1246 *
1247 * Returns zero on success; non-zero on error.
1248 */
1249static int
1250parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
1251 unsigned char *data, struct list_head *auth_tok_list,
1252 struct ecryptfs_auth_tok **new_auth_tok,
1253 size_t *packet_size, size_t max_packet_size)
1254{
Michael Halcrow237fead2006-10-04 02:16:22 -07001255 size_t body_size;
1256 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1257 size_t length_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001258 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001259
1260 (*packet_size) = 0;
1261 (*new_auth_tok) = NULL;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001262 /**
1263 *This format is inspired by OpenPGP; see RFC 2440
1264 * packet tag 3
1265 *
1266 * Tag 3 identifier (1 byte)
1267 * Max Tag 3 packet size (max 3 bytes)
1268 * Version (1 byte)
1269 * Cipher code (1 byte)
1270 * S2K specifier (1 byte)
1271 * Hash identifier (1 byte)
1272 * Salt (ECRYPTFS_SALT_SIZE)
1273 * Hash iterations (1 byte)
1274 * Encrypted key (arbitrary)
1275 *
1276 * (ECRYPTFS_SALT_SIZE + 7) minimum packet size
Michael Halcrow237fead2006-10-04 02:16:22 -07001277 */
Michael Halcrowc59becf2007-10-16 01:27:56 -07001278 if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) {
1279 printk(KERN_ERR "Max packet size too large\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001280 rc = -EINVAL;
1281 goto out;
1282 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001283 if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001284 printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n",
1285 ECRYPTFS_TAG_3_PACKET_TYPE);
Michael Halcrow237fead2006-10-04 02:16:22 -07001286 rc = -EINVAL;
1287 goto out;
1288 }
1289 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1290 * at end of function upon failure */
1291 auth_tok_list_item =
Robert P. J. Dayc3762222007-02-10 01:45:03 -08001292 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
Michael Halcrow237fead2006-10-04 02:16:22 -07001293 if (!auth_tok_list_item) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001294 printk(KERN_ERR "Unable to allocate memory\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001295 rc = -ENOMEM;
1296 goto out;
1297 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001298 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001299 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1300 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001301 if (rc) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001302 printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n",
1303 rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07001304 goto out_free;
1305 }
Michael Halcrowc59becf2007-10-16 01:27:56 -07001306 if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001307 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001308 rc = -EINVAL;
1309 goto out_free;
1310 }
1311 (*packet_size) += length_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07001312 if (unlikely((*packet_size) + body_size > max_packet_size)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001313 printk(KERN_ERR "Packet size exceeds max\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001314 rc = -EINVAL;
1315 goto out_free;
1316 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001317 (*new_auth_tok)->session_key.encrypted_key_size =
Michael Halcrowc59becf2007-10-16 01:27:56 -07001318 (body_size - (ECRYPTFS_SALT_SIZE + 5));
Ramon de Carvalho Vallef151cd22009-07-28 13:58:22 -05001319 if ((*new_auth_tok)->session_key.encrypted_key_size
1320 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
1321 printk(KERN_WARNING "Tag 3 packet contains key larger "
1322 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n");
1323 rc = -EINVAL;
1324 goto out_free;
1325 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001326 if (unlikely(data[(*packet_size)++] != 0x04)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001327 printk(KERN_WARNING "Unknown version number [%d]\n",
1328 data[(*packet_size) - 1]);
Michael Halcrow237fead2006-10-04 02:16:22 -07001329 rc = -EINVAL;
1330 goto out_free;
1331 }
Tyler Hicksb0105ea2009-08-11 00:36:32 -05001332 rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher,
1333 (u16)data[(*packet_size)]);
1334 if (rc)
1335 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07001336 /* A little extra work to differentiate among the AES key
1337 * sizes; see RFC2440 */
1338 switch(data[(*packet_size)++]) {
1339 case RFC2440_CIPHER_AES_192:
1340 crypt_stat->key_size = 24;
1341 break;
1342 default:
1343 crypt_stat->key_size =
1344 (*new_auth_tok)->session_key.encrypted_key_size;
1345 }
Tyler Hicksb0105ea2009-08-11 00:36:32 -05001346 rc = ecryptfs_init_crypt_ctx(crypt_stat);
1347 if (rc)
1348 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07001349 if (unlikely(data[(*packet_size)++] != 0x03)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001350 printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001351 rc = -ENOSYS;
1352 goto out_free;
1353 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001354 /* TODO: finish the hash mapping */
Michael Halcrow237fead2006-10-04 02:16:22 -07001355 switch (data[(*packet_size)++]) {
1356 case 0x01: /* See RFC2440 for these numbers and their mappings */
1357 /* Choose MD5 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001358 memcpy((*new_auth_tok)->token.password.salt,
1359 &data[(*packet_size)], ECRYPTFS_SALT_SIZE);
1360 (*packet_size) += ECRYPTFS_SALT_SIZE;
Michael Halcrow237fead2006-10-04 02:16:22 -07001361 /* This conversion was taken straight from RFC2440 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001362 (*new_auth_tok)->token.password.hash_iterations =
1363 ((u32) 16 + (data[(*packet_size)] & 15))
1364 << ((data[(*packet_size)] >> 4) + 6);
1365 (*packet_size)++;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001366 /* Friendly reminder:
1367 * (*new_auth_tok)->session_key.encrypted_key_size =
1368 * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */
Michael Halcrow237fead2006-10-04 02:16:22 -07001369 memcpy((*new_auth_tok)->session_key.encrypted_key,
1370 &data[(*packet_size)],
1371 (*new_auth_tok)->session_key.encrypted_key_size);
1372 (*packet_size) +=
1373 (*new_auth_tok)->session_key.encrypted_key_size;
1374 (*new_auth_tok)->session_key.flags &=
1375 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1376 (*new_auth_tok)->session_key.flags |=
1377 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001378 (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001379 break;
1380 default:
1381 ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: "
1382 "[%d]\n", data[(*packet_size) - 1]);
1383 rc = -ENOSYS;
1384 goto out_free;
1385 }
1386 (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD;
1387 /* TODO: Parametarize; we might actually want userspace to
1388 * decrypt the session key. */
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001389 (*new_auth_tok)->session_key.flags &=
1390 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1391 (*new_auth_tok)->session_key.flags &=
1392 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
Michael Halcrow237fead2006-10-04 02:16:22 -07001393 list_add(&auth_tok_list_item->list, auth_tok_list);
1394 goto out;
1395out_free:
1396 (*new_auth_tok) = NULL;
1397 memset(auth_tok_list_item, 0,
1398 sizeof(struct ecryptfs_auth_tok_list_item));
1399 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1400 auth_tok_list_item);
1401out:
1402 if (rc)
1403 (*packet_size) = 0;
1404 return rc;
1405}
1406
1407/**
1408 * parse_tag_11_packet
1409 * @data: The raw bytes of the packet
1410 * @contents: This function writes the data contents of the literal
1411 * packet into this memory location
1412 * @max_contents_bytes: The maximum number of bytes that this function
1413 * is allowed to write into contents
1414 * @tag_11_contents_size: This function writes the size of the parsed
1415 * contents into this memory location; zero on
1416 * error
1417 * @packet_size: This function writes the size of the parsed packet
1418 * into this memory location; zero on error
1419 * @max_packet_size: maximum number of bytes to parse
1420 *
1421 * Returns zero on success; non-zero on error.
1422 */
1423static int
1424parse_tag_11_packet(unsigned char *data, unsigned char *contents,
1425 size_t max_contents_bytes, size_t *tag_11_contents_size,
1426 size_t *packet_size, size_t max_packet_size)
1427{
Michael Halcrow237fead2006-10-04 02:16:22 -07001428 size_t body_size;
1429 size_t length_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001430 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001431
1432 (*packet_size) = 0;
1433 (*tag_11_contents_size) = 0;
Michael Halcrowf6481042007-10-16 01:27:57 -07001434 /* This format is inspired by OpenPGP; see RFC 2440
1435 * packet tag 11
1436 *
1437 * Tag 11 identifier (1 byte)
1438 * Max Tag 11 packet size (max 3 bytes)
1439 * Binary format specifier (1 byte)
1440 * Filename length (1 byte)
1441 * Filename ("_CONSOLE") (8 bytes)
1442 * Modification date (4 bytes)
1443 * Literal data (arbitrary)
1444 *
1445 * We need at least 16 bytes of data for the packet to even be
1446 * valid.
Michael Halcrow237fead2006-10-04 02:16:22 -07001447 */
Michael Halcrowf6481042007-10-16 01:27:57 -07001448 if (max_packet_size < 16) {
1449 printk(KERN_ERR "Maximum packet size too small\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001450 rc = -EINVAL;
1451 goto out;
1452 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001453 if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001454 printk(KERN_WARNING "Invalid tag 11 packet format\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001455 rc = -EINVAL;
1456 goto out;
1457 }
Michael Halcrowf66e8832008-04-29 00:59:51 -07001458 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1459 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001460 if (rc) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001461 printk(KERN_WARNING "Invalid tag 11 packet format\n");
1462 goto out;
1463 }
1464 if (body_size < 14) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001465 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrowf6481042007-10-16 01:27:57 -07001466 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07001467 goto out;
1468 }
1469 (*packet_size) += length_size;
Michael Halcrowf6481042007-10-16 01:27:57 -07001470 (*tag_11_contents_size) = (body_size - 14);
Michael Halcrow237fead2006-10-04 02:16:22 -07001471 if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001472 printk(KERN_ERR "Packet size exceeds max\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001473 rc = -EINVAL;
1474 goto out;
1475 }
Tyler Hicks6352a292009-07-28 13:57:01 -05001476 if (unlikely((*tag_11_contents_size) > max_contents_bytes)) {
1477 printk(KERN_ERR "Literal data section in tag 11 packet exceeds "
1478 "expected size\n");
1479 rc = -EINVAL;
1480 goto out;
1481 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001482 if (data[(*packet_size)++] != 0x62) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001483 printk(KERN_WARNING "Unrecognizable packet\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001484 rc = -EINVAL;
1485 goto out;
1486 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001487 if (data[(*packet_size)++] != 0x08) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001488 printk(KERN_WARNING "Unrecognizable packet\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001489 rc = -EINVAL;
1490 goto out;
1491 }
Michael Halcrowf6481042007-10-16 01:27:57 -07001492 (*packet_size) += 12; /* Ignore filename and modification date */
Michael Halcrow237fead2006-10-04 02:16:22 -07001493 memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size));
1494 (*packet_size) += (*tag_11_contents_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001495out:
1496 if (rc) {
1497 (*packet_size) = 0;
1498 (*tag_11_contents_size) = 0;
1499 }
1500 return rc;
1501}
1502
1503/**
Michael Halcrowf4aad162007-10-16 01:27:53 -07001504 * ecryptfs_verify_version
1505 * @version: The version number to confirm
1506 *
1507 * Returns zero on good version; non-zero otherwise
1508 */
1509static int ecryptfs_verify_version(u16 version)
1510{
1511 int rc = 0;
1512 unsigned char major;
1513 unsigned char minor;
1514
1515 major = ((version >> 8) & 0xFF);
1516 minor = (version & 0xFF);
1517 if (major != ECRYPTFS_VERSION_MAJOR) {
1518 ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
1519 "Expected [%d]; got [%d]\n",
1520 ECRYPTFS_VERSION_MAJOR, major);
1521 rc = -EINVAL;
1522 goto out;
1523 }
1524 if (minor != ECRYPTFS_VERSION_MINOR) {
1525 ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
1526 "Expected [%d]; got [%d]\n",
1527 ECRYPTFS_VERSION_MINOR, minor);
1528 rc = -EINVAL;
1529 goto out;
1530 }
1531out:
1532 return rc;
1533}
1534
1535int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
1536 struct ecryptfs_auth_tok **auth_tok,
1537 char *sig)
1538{
1539 int rc = 0;
1540
1541 (*auth_tok_key) = request_key(&key_type_user, sig, NULL);
1542 if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
1543 printk(KERN_ERR "Could not find key with description: [%s]\n",
1544 sig);
Eric Sandeen982363c2008-07-23 21:30:04 -07001545 rc = process_request_key_err(PTR_ERR(*auth_tok_key));
Michael Halcrowf4aad162007-10-16 01:27:53 -07001546 goto out;
1547 }
1548 (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key);
1549 if (ecryptfs_verify_version((*auth_tok)->version)) {
1550 printk(KERN_ERR
1551 "Data structure version mismatch. "
1552 "Userspace tools must match eCryptfs "
1553 "kernel module with major version [%d] "
1554 "and minor version [%d]\n",
1555 ECRYPTFS_VERSION_MAJOR,
1556 ECRYPTFS_VERSION_MINOR);
1557 rc = -EINVAL;
1558 goto out;
1559 }
1560 if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
1561 && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
1562 printk(KERN_ERR "Invalid auth_tok structure "
1563 "returned from key query\n");
1564 rc = -EINVAL;
1565 goto out;
1566 }
1567out:
1568 return rc;
1569}
1570
1571/**
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001572 * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok.
1573 * @auth_tok: The passphrase authentication token to use to encrypt the FEK
1574 * @crypt_stat: The cryptographic context
Michael Halcrow237fead2006-10-04 02:16:22 -07001575 *
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001576 * Returns zero on success; non-zero error otherwise
Michael Halcrow237fead2006-10-04 02:16:22 -07001577 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07001578static int
1579decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1580 struct ecryptfs_crypt_stat *crypt_stat)
Michael Halcrow237fead2006-10-04 02:16:22 -07001581{
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001582 struct scatterlist dst_sg[2];
1583 struct scatterlist src_sg[2];
Michael Halcrowdd8e2902007-10-16 01:28:03 -07001584 struct mutex *tfm_mutex;
Michael Halcrow8bba0662006-10-30 22:07:18 -08001585 struct blkcipher_desc desc = {
1586 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
1587 };
1588 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001589
Michael Halcrowf4aad162007-10-16 01:27:53 -07001590 if (unlikely(ecryptfs_verbosity > 0)) {
1591 ecryptfs_printk(
1592 KERN_DEBUG, "Session key encryption key (size [%d]):\n",
1593 auth_tok->token.password.session_key_encryption_key_bytes);
1594 ecryptfs_dump_hex(
1595 auth_tok->token.password.session_key_encryption_key,
1596 auth_tok->token.password.session_key_encryption_key_bytes);
Michael Halcrow237fead2006-10-04 02:16:22 -07001597 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001598 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
1599 crypt_stat->cipher);
1600 if (unlikely(rc)) {
1601 printk(KERN_ERR "Internal error whilst attempting to get "
1602 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1603 crypt_stat->cipher, rc);
1604 goto out;
1605 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07001606 rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
1607 auth_tok->session_key.encrypted_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001608 src_sg, 2);
1609 if (rc < 1 || rc > 2) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001610 printk(KERN_ERR "Internal error whilst attempting to convert "
1611 "auth_tok->session_key.encrypted_key to scatterlist; "
1612 "expected rc = 1; got rc = [%d]. "
1613 "auth_tok->session_key.encrypted_key_size = [%d]\n", rc,
1614 auth_tok->session_key.encrypted_key_size);
1615 goto out;
1616 }
1617 auth_tok->session_key.decrypted_key_size =
1618 auth_tok->session_key.encrypted_key_size;
Michael Halcrow5dda6992007-10-16 01:28:06 -07001619 rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key,
1620 auth_tok->session_key.decrypted_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001621 dst_sg, 2);
1622 if (rc < 1 || rc > 2) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001623 printk(KERN_ERR "Internal error whilst attempting to convert "
1624 "auth_tok->session_key.decrypted_key to scatterlist; "
1625 "expected rc = 1; got rc = [%d]\n", rc);
1626 goto out;
1627 }
1628 mutex_lock(tfm_mutex);
1629 rc = crypto_blkcipher_setkey(
1630 desc.tfm, auth_tok->token.password.session_key_encryption_key,
1631 crypt_stat->key_size);
1632 if (unlikely(rc < 0)) {
1633 mutex_unlock(tfm_mutex);
Michael Halcrowe5d9cbd2006-10-30 22:07:16 -08001634 printk(KERN_ERR "Error setting key for crypto context\n");
1635 rc = -EINVAL;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001636 goto out;
Michael Halcrowe5d9cbd2006-10-30 22:07:16 -08001637 }
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001638 rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg,
Michael Halcrow8bba0662006-10-30 22:07:18 -08001639 auth_tok->session_key.encrypted_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001640 mutex_unlock(tfm_mutex);
1641 if (unlikely(rc)) {
Michael Halcrow8bba0662006-10-30 22:07:18 -08001642 printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001643 goto out;
Michael Halcrow8bba0662006-10-30 22:07:18 -08001644 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001645 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1646 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1647 auth_tok->session_key.decrypted_key_size);
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001648 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001649 if (unlikely(ecryptfs_verbosity > 0)) {
1650 ecryptfs_printk(KERN_DEBUG, "FEK of size [%d]:\n",
1651 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001652 ecryptfs_dump_hex(crypt_stat->key,
1653 crypt_stat->key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001654 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001655out:
1656 return rc;
1657}
1658
1659/**
1660 * ecryptfs_parse_packet_set
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001661 * @crypt_stat: The cryptographic context
1662 * @src: Virtual address of region of memory containing the packets
1663 * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set
Michael Halcrow237fead2006-10-04 02:16:22 -07001664 *
1665 * Get crypt_stat to have the file's session key if the requisite key
1666 * is available to decrypt the session key.
1667 *
1668 * Returns Zero if a valid authentication token was retrieved and
1669 * processed; negative value for file not encrypted or for error
1670 * conditions.
1671 */
1672int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
1673 unsigned char *src,
1674 struct dentry *ecryptfs_dentry)
1675{
1676 size_t i = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001677 size_t found_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07001678 size_t next_packet_is_auth_tok_packet;
Michael Halcrow237fead2006-10-04 02:16:22 -07001679 struct list_head auth_tok_list;
Michael Halcrowdd8e2902007-10-16 01:28:03 -07001680 struct ecryptfs_auth_tok *matching_auth_tok;
1681 struct ecryptfs_auth_tok *candidate_auth_tok;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001682 char *candidate_auth_tok_sig;
Michael Halcrow237fead2006-10-04 02:16:22 -07001683 size_t packet_size;
1684 struct ecryptfs_auth_tok *new_auth_tok;
1685 unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE];
Michael Halcrowf4aad162007-10-16 01:27:53 -07001686 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
Michael Halcrow237fead2006-10-04 02:16:22 -07001687 size_t tag_11_contents_size;
1688 size_t tag_11_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001689 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001690
1691 INIT_LIST_HEAD(&auth_tok_list);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001692 /* Parse the header to find as many packets as we can; these will be
Michael Halcrow237fead2006-10-04 02:16:22 -07001693 * added the our &auth_tok_list */
1694 next_packet_is_auth_tok_packet = 1;
1695 while (next_packet_is_auth_tok_packet) {
1696 size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i);
1697
1698 switch (src[i]) {
1699 case ECRYPTFS_TAG_3_PACKET_TYPE:
1700 rc = parse_tag_3_packet(crypt_stat,
1701 (unsigned char *)&src[i],
1702 &auth_tok_list, &new_auth_tok,
1703 &packet_size, max_packet_size);
1704 if (rc) {
1705 ecryptfs_printk(KERN_ERR, "Error parsing "
1706 "tag 3 packet\n");
1707 rc = -EIO;
1708 goto out_wipe_list;
1709 }
1710 i += packet_size;
1711 rc = parse_tag_11_packet((unsigned char *)&src[i],
1712 sig_tmp_space,
1713 ECRYPTFS_SIG_SIZE,
1714 &tag_11_contents_size,
1715 &tag_11_packet_size,
1716 max_packet_size);
1717 if (rc) {
1718 ecryptfs_printk(KERN_ERR, "No valid "
1719 "(ecryptfs-specific) literal "
1720 "packet containing "
1721 "authentication token "
1722 "signature found after "
1723 "tag 3 packet\n");
1724 rc = -EIO;
1725 goto out_wipe_list;
1726 }
1727 i += tag_11_packet_size;
1728 if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) {
1729 ecryptfs_printk(KERN_ERR, "Expected "
1730 "signature of size [%d]; "
1731 "read size [%d]\n",
1732 ECRYPTFS_SIG_SIZE,
1733 tag_11_contents_size);
1734 rc = -EIO;
1735 goto out_wipe_list;
1736 }
1737 ecryptfs_to_hex(new_auth_tok->token.password.signature,
1738 sig_tmp_space, tag_11_contents_size);
1739 new_auth_tok->token.password.signature[
1740 ECRYPTFS_PASSWORD_SIG_SIZE] = '\0';
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001741 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
Michael Halcrow237fead2006-10-04 02:16:22 -07001742 break;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001743 case ECRYPTFS_TAG_1_PACKET_TYPE:
1744 rc = parse_tag_1_packet(crypt_stat,
1745 (unsigned char *)&src[i],
1746 &auth_tok_list, &new_auth_tok,
1747 &packet_size, max_packet_size);
1748 if (rc) {
1749 ecryptfs_printk(KERN_ERR, "Error parsing "
1750 "tag 1 packet\n");
1751 rc = -EIO;
1752 goto out_wipe_list;
1753 }
1754 i += packet_size;
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001755 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001756 break;
Michael Halcrow237fead2006-10-04 02:16:22 -07001757 case ECRYPTFS_TAG_11_PACKET_TYPE:
1758 ecryptfs_printk(KERN_WARNING, "Invalid packet set "
1759 "(Tag 11 not allowed by itself)\n");
1760 rc = -EIO;
1761 goto out_wipe_list;
1762 break;
1763 default:
1764 ecryptfs_printk(KERN_DEBUG, "No packet at offset "
1765 "[%d] of the file header; hex value of "
1766 "character is [0x%.2x]\n", i, src[i]);
1767 next_packet_is_auth_tok_packet = 0;
1768 }
1769 }
1770 if (list_empty(&auth_tok_list)) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001771 printk(KERN_ERR "The lower file appears to be a non-encrypted "
1772 "eCryptfs file; this is not supported in this version "
1773 "of the eCryptfs kernel module\n");
1774 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07001775 goto out;
1776 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001777 /* auth_tok_list contains the set of authentication tokens
1778 * parsed from the metadata. We need to find a matching
1779 * authentication token that has the secret component(s)
1780 * necessary to decrypt the EFEK in the auth_tok parsed from
1781 * the metadata. There may be several potential matches, but
1782 * just one will be sufficient to decrypt to get the FEK. */
1783find_next_matching_auth_tok:
1784 found_auth_tok = 0;
1785 list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001786 candidate_auth_tok = &auth_tok_list_item->auth_tok;
1787 if (unlikely(ecryptfs_verbosity > 0)) {
1788 ecryptfs_printk(KERN_DEBUG,
1789 "Considering cadidate auth tok:\n");
1790 ecryptfs_dump_auth_tok(candidate_auth_tok);
1791 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07001792 rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig,
1793 candidate_auth_tok);
1794 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001795 printk(KERN_ERR
1796 "Unrecognized candidate auth tok type: [%d]\n",
1797 candidate_auth_tok->token_type);
1798 rc = -EINVAL;
1799 goto out_wipe_list;
1800 }
Michael Halcrow9c79f342009-01-06 14:41:57 -08001801 ecryptfs_find_auth_tok_for_sig(&matching_auth_tok,
1802 crypt_stat->mount_crypt_stat,
Michael Halcrow5dda6992007-10-16 01:28:06 -07001803 candidate_auth_tok_sig);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001804 if (matching_auth_tok) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001805 found_auth_tok = 1;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001806 goto found_matching_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07001807 }
1808 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001809 if (!found_auth_tok) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001810 ecryptfs_printk(KERN_ERR, "Could not find a usable "
1811 "authentication token\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001812 rc = -EIO;
1813 goto out_wipe_list;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001814 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001815found_matching_auth_tok:
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001816 if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
Michael Halcrowdddfa462007-02-12 00:53:44 -08001817 memcpy(&(candidate_auth_tok->token.private_key),
Michael Halcrowf4aad162007-10-16 01:27:53 -07001818 &(matching_auth_tok->token.private_key),
Michael Halcrowdddfa462007-02-12 00:53:44 -08001819 sizeof(struct ecryptfs_private_key));
Michael Halcrowf4aad162007-10-16 01:27:53 -07001820 rc = decrypt_pki_encrypted_session_key(candidate_auth_tok,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001821 crypt_stat);
1822 } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001823 memcpy(&(candidate_auth_tok->token.password),
Michael Halcrowf4aad162007-10-16 01:27:53 -07001824 &(matching_auth_tok->token.password),
Michael Halcrow237fead2006-10-04 02:16:22 -07001825 sizeof(struct ecryptfs_password));
Michael Halcrowf4aad162007-10-16 01:27:53 -07001826 rc = decrypt_passphrase_encrypted_session_key(
1827 candidate_auth_tok, crypt_stat);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001828 }
1829 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001830 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1831
1832 ecryptfs_printk(KERN_WARNING, "Error decrypting the "
1833 "session key for authentication token with sig "
1834 "[%.*s]; rc = [%d]. Removing auth tok "
1835 "candidate from the list and searching for "
1836 "the next match.\n", candidate_auth_tok_sig,
1837 ECRYPTFS_SIG_SIZE_HEX, rc);
1838 list_for_each_entry_safe(auth_tok_list_item,
1839 auth_tok_list_item_tmp,
1840 &auth_tok_list, list) {
1841 if (candidate_auth_tok
1842 == &auth_tok_list_item->auth_tok) {
1843 list_del(&auth_tok_list_item->list);
1844 kmem_cache_free(
1845 ecryptfs_auth_tok_list_item_cache,
1846 auth_tok_list_item);
1847 goto find_next_matching_auth_tok;
1848 }
1849 }
1850 BUG();
Michael Halcrowdddfa462007-02-12 00:53:44 -08001851 }
1852 rc = ecryptfs_compute_root_iv(crypt_stat);
1853 if (rc) {
1854 ecryptfs_printk(KERN_ERR, "Error computing "
1855 "the root IV\n");
1856 goto out_wipe_list;
Michael Halcrow237fead2006-10-04 02:16:22 -07001857 }
1858 rc = ecryptfs_init_crypt_ctx(crypt_stat);
1859 if (rc) {
1860 ecryptfs_printk(KERN_ERR, "Error initializing crypto "
1861 "context for cipher [%s]; rc = [%d]\n",
1862 crypt_stat->cipher, rc);
1863 }
1864out_wipe_list:
1865 wipe_auth_tok_list(&auth_tok_list);
1866out:
1867 return rc;
1868}
Michael Halcrowf4aad162007-10-16 01:27:53 -07001869
Michael Halcrowdddfa462007-02-12 00:53:44 -08001870static int
1871pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
1872 struct ecryptfs_crypt_stat *crypt_stat,
1873 struct ecryptfs_key_record *key_rec)
1874{
1875 struct ecryptfs_msg_ctx *msg_ctx = NULL;
Tyler Hicks624ae522008-10-15 22:02:51 -07001876 char *payload = NULL;
1877 size_t payload_len;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001878 struct ecryptfs_message *msg;
1879 int rc;
1880
1881 rc = write_tag_66_packet(auth_tok->token.private_key.signature,
Michael Halcrow9c79f342009-01-06 14:41:57 -08001882 ecryptfs_code_for_cipher_string(
1883 crypt_stat->cipher,
1884 crypt_stat->key_size),
Tyler Hicks624ae522008-10-15 22:02:51 -07001885 crypt_stat, &payload, &payload_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001886 if (rc) {
1887 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
1888 goto out;
1889 }
Tyler Hicks624ae522008-10-15 22:02:51 -07001890 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001891 if (rc) {
Tyler Hicks624ae522008-10-15 22:02:51 -07001892 ecryptfs_printk(KERN_ERR, "Error sending message to "
1893 "ecryptfsd\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001894 goto out;
1895 }
1896 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1897 if (rc) {
1898 ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet "
1899 "from the user space daemon\n");
1900 rc = -EIO;
1901 goto out;
1902 }
1903 rc = parse_tag_67_packet(key_rec, msg);
1904 if (rc)
1905 ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n");
1906 kfree(msg);
1907out:
Tyler Hicks624ae522008-10-15 22:02:51 -07001908 kfree(payload);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001909 return rc;
1910}
1911/**
1912 * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet
1913 * @dest: Buffer into which to write the packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001914 * @remaining_bytes: Maximum number of bytes that can be writtn
1915 * @auth_tok: The authentication token used for generating the tag 1 packet
1916 * @crypt_stat: The cryptographic context
1917 * @key_rec: The key record struct for the tag 1 packet
Michael Halcrowdddfa462007-02-12 00:53:44 -08001918 * @packet_size: This function will write the number of bytes that end
1919 * up constituting the packet; set to zero on error
1920 *
1921 * Returns zero on success; non-zero on error.
1922 */
1923static int
Michael Halcrowf4aad162007-10-16 01:27:53 -07001924write_tag_1_packet(char *dest, size_t *remaining_bytes,
1925 struct ecryptfs_auth_tok *auth_tok,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001926 struct ecryptfs_crypt_stat *crypt_stat,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001927 struct ecryptfs_key_record *key_rec, size_t *packet_size)
1928{
1929 size_t i;
1930 size_t encrypted_session_key_valid = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001931 size_t packet_size_length;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001932 size_t max_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001933 int rc = 0;
1934
1935 (*packet_size) = 0;
1936 ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature,
1937 ECRYPTFS_SIG_SIZE);
1938 encrypted_session_key_valid = 0;
1939 for (i = 0; i < crypt_stat->key_size; i++)
1940 encrypted_session_key_valid |=
1941 auth_tok->session_key.encrypted_key[i];
1942 if (encrypted_session_key_valid) {
1943 memcpy(key_rec->enc_key,
1944 auth_tok->session_key.encrypted_key,
1945 auth_tok->session_key.encrypted_key_size);
1946 goto encrypted_session_key_set;
1947 }
1948 if (auth_tok->session_key.encrypted_key_size == 0)
1949 auth_tok->session_key.encrypted_key_size =
1950 auth_tok->token.private_key.key_size;
1951 rc = pki_encrypt_session_key(auth_tok, crypt_stat, key_rec);
1952 if (rc) {
Michael Halcrowf66e8832008-04-29 00:59:51 -07001953 printk(KERN_ERR "Failed to encrypt session key via a key "
1954 "module; rc = [%d]\n", rc);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001955 goto out;
1956 }
1957 if (ecryptfs_verbosity > 0) {
1958 ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n");
1959 ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size);
1960 }
1961encrypted_session_key_set:
Michael Halcrowf4aad162007-10-16 01:27:53 -07001962 /* This format is inspired by OpenPGP; see RFC 2440
1963 * packet tag 1 */
1964 max_packet_size = (1 /* Tag 1 identifier */
1965 + 3 /* Max Tag 1 packet size */
1966 + 1 /* Version */
1967 + ECRYPTFS_SIG_SIZE /* Key identifier */
1968 + 1 /* Cipher identifier */
1969 + key_rec->enc_key_size); /* Encrypted key size */
1970 if (max_packet_size > (*remaining_bytes)) {
1971 printk(KERN_ERR "Packet length larger than maximum allowable; "
Andrew Morton81acbcd2007-10-16 01:27:59 -07001972 "need up to [%td] bytes, but there are only [%td] "
Michael Halcrowf4aad162007-10-16 01:27:53 -07001973 "available\n", max_packet_size, (*remaining_bytes));
Michael Halcrowdddfa462007-02-12 00:53:44 -08001974 rc = -EINVAL;
1975 goto out;
1976 }
1977 dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001978 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
1979 (max_packet_size - 4),
1980 &packet_size_length);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001981 if (rc) {
1982 ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet "
1983 "header; cannot generate packet length\n");
1984 goto out;
1985 }
1986 (*packet_size) += packet_size_length;
1987 dest[(*packet_size)++] = 0x03; /* version 3 */
1988 memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE);
1989 (*packet_size) += ECRYPTFS_SIG_SIZE;
1990 dest[(*packet_size)++] = RFC2440_CIPHER_RSA;
1991 memcpy(&dest[(*packet_size)], key_rec->enc_key,
1992 key_rec->enc_key_size);
1993 (*packet_size) += key_rec->enc_key_size;
1994out:
1995 if (rc)
1996 (*packet_size) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001997 else
1998 (*remaining_bytes) -= (*packet_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001999 return rc;
2000}
Michael Halcrow237fead2006-10-04 02:16:22 -07002001
2002/**
2003 * write_tag_11_packet
2004 * @dest: Target into which Tag 11 packet is to be written
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002005 * @remaining_bytes: Maximum packet length
Michael Halcrow237fead2006-10-04 02:16:22 -07002006 * @contents: Byte array of contents to copy in
2007 * @contents_length: Number of bytes in contents
2008 * @packet_length: Length of the Tag 11 packet written; zero on error
2009 *
2010 * Returns zero on success; non-zero on error.
2011 */
2012static int
Andrew Morton81acbcd2007-10-16 01:27:59 -07002013write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents,
Michael Halcrow146a4602007-10-16 01:27:58 -07002014 size_t contents_length, size_t *packet_length)
Michael Halcrow237fead2006-10-04 02:16:22 -07002015{
Michael Halcrow237fead2006-10-04 02:16:22 -07002016 size_t packet_size_length;
Michael Halcrow146a4602007-10-16 01:27:58 -07002017 size_t max_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002018 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002019
2020 (*packet_length) = 0;
Michael Halcrow146a4602007-10-16 01:27:58 -07002021 /* This format is inspired by OpenPGP; see RFC 2440
2022 * packet tag 11 */
2023 max_packet_size = (1 /* Tag 11 identifier */
2024 + 3 /* Max Tag 11 packet size */
2025 + 1 /* Binary format specifier */
2026 + 1 /* Filename length */
2027 + 8 /* Filename ("_CONSOLE") */
2028 + 4 /* Modification date */
2029 + contents_length); /* Literal data */
2030 if (max_packet_size > (*remaining_bytes)) {
2031 printk(KERN_ERR "Packet length larger than maximum allowable; "
Andrew Morton81acbcd2007-10-16 01:27:59 -07002032 "need up to [%td] bytes, but there are only [%td] "
Michael Halcrow146a4602007-10-16 01:27:58 -07002033 "available\n", max_packet_size, (*remaining_bytes));
Michael Halcrow237fead2006-10-04 02:16:22 -07002034 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07002035 goto out;
2036 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002037 dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -07002038 rc = ecryptfs_write_packet_length(&dest[(*packet_length)],
2039 (max_packet_size - 4),
2040 &packet_size_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002041 if (rc) {
Michael Halcrow146a4602007-10-16 01:27:58 -07002042 printk(KERN_ERR "Error generating tag 11 packet header; cannot "
2043 "generate packet length. rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002044 goto out;
2045 }
2046 (*packet_length) += packet_size_length;
Michael Halcrow146a4602007-10-16 01:27:58 -07002047 dest[(*packet_length)++] = 0x62; /* binary data format specifier */
Michael Halcrow237fead2006-10-04 02:16:22 -07002048 dest[(*packet_length)++] = 8;
2049 memcpy(&dest[(*packet_length)], "_CONSOLE", 8);
2050 (*packet_length) += 8;
Michael Halcrow237fead2006-10-04 02:16:22 -07002051 memset(&dest[(*packet_length)], 0x00, 4);
2052 (*packet_length) += 4;
Michael Halcrow237fead2006-10-04 02:16:22 -07002053 memcpy(&dest[(*packet_length)], contents, contents_length);
2054 (*packet_length) += contents_length;
2055 out:
2056 if (rc)
2057 (*packet_length) = 0;
Michael Halcrow146a4602007-10-16 01:27:58 -07002058 else
2059 (*remaining_bytes) -= (*packet_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002060 return rc;
2061}
2062
2063/**
2064 * write_tag_3_packet
2065 * @dest: Buffer into which to write the packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002066 * @remaining_bytes: Maximum number of bytes that can be written
Michael Halcrow237fead2006-10-04 02:16:22 -07002067 * @auth_tok: Authentication token
2068 * @crypt_stat: The cryptographic context
2069 * @key_rec: encrypted key
2070 * @packet_size: This function will write the number of bytes that end
2071 * up constituting the packet; set to zero on error
2072 *
2073 * Returns zero on success; non-zero on error.
2074 */
2075static int
Michael Halcrowf4aad162007-10-16 01:27:53 -07002076write_tag_3_packet(char *dest, size_t *remaining_bytes,
2077 struct ecryptfs_auth_tok *auth_tok,
Michael Halcrow237fead2006-10-04 02:16:22 -07002078 struct ecryptfs_crypt_stat *crypt_stat,
2079 struct ecryptfs_key_record *key_rec, size_t *packet_size)
2080{
Michael Halcrow237fead2006-10-04 02:16:22 -07002081 size_t i;
Michael Halcrow237fead2006-10-04 02:16:22 -07002082 size_t encrypted_session_key_valid = 0;
2083 char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002084 struct scatterlist dst_sg[2];
2085 struct scatterlist src_sg[2];
Michael Halcrow237fead2006-10-04 02:16:22 -07002086 struct mutex *tfm_mutex = NULL;
Trevor Highland19e66a62008-02-06 01:38:36 -08002087 u8 cipher_code;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002088 size_t packet_size_length;
2089 size_t max_packet_size;
2090 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2091 crypt_stat->mount_crypt_stat;
Michael Halcrow8bba0662006-10-30 22:07:18 -08002092 struct blkcipher_desc desc = {
2093 .tfm = NULL,
2094 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
2095 };
2096 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002097
2098 (*packet_size) = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002099 ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
Michael Halcrow237fead2006-10-04 02:16:22 -07002100 ECRYPTFS_SIG_SIZE);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002101 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
2102 crypt_stat->cipher);
2103 if (unlikely(rc)) {
2104 printk(KERN_ERR "Internal error whilst attempting to get "
2105 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
2106 crypt_stat->cipher, rc);
2107 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -07002108 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002109 if (mount_crypt_stat->global_default_cipher_key_size == 0) {
2110 struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm);
2111
2112 printk(KERN_WARNING "No key size specified at mount; "
2113 "defaulting to [%d]\n", alg->max_keysize);
2114 mount_crypt_stat->global_default_cipher_key_size =
2115 alg->max_keysize;
2116 }
2117 if (crypt_stat->key_size == 0)
2118 crypt_stat->key_size =
2119 mount_crypt_stat->global_default_cipher_key_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07002120 if (auth_tok->session_key.encrypted_key_size == 0)
2121 auth_tok->session_key.encrypted_key_size =
2122 crypt_stat->key_size;
2123 if (crypt_stat->key_size == 24
2124 && strcmp("aes", crypt_stat->cipher) == 0) {
2125 memset((crypt_stat->key + 24), 0, 8);
2126 auth_tok->session_key.encrypted_key_size = 32;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002127 } else
2128 auth_tok->session_key.encrypted_key_size = crypt_stat->key_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002129 key_rec->enc_key_size =
Michael Halcrow237fead2006-10-04 02:16:22 -07002130 auth_tok->session_key.encrypted_key_size;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002131 encrypted_session_key_valid = 0;
2132 for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++)
2133 encrypted_session_key_valid |=
2134 auth_tok->session_key.encrypted_key[i];
2135 if (encrypted_session_key_valid) {
2136 ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; "
2137 "using auth_tok->session_key.encrypted_key, "
2138 "where key_rec->enc_key_size = [%d]\n",
2139 key_rec->enc_key_size);
2140 memcpy(key_rec->enc_key,
2141 auth_tok->session_key.encrypted_key,
2142 key_rec->enc_key_size);
2143 goto encrypted_session_key_set;
2144 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08002145 if (auth_tok->token.password.flags &
2146 ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002147 ecryptfs_printk(KERN_DEBUG, "Using previously generated "
2148 "session key encryption key of size [%d]\n",
2149 auth_tok->token.password.
2150 session_key_encryption_key_bytes);
2151 memcpy(session_key_encryption_key,
2152 auth_tok->token.password.session_key_encryption_key,
2153 crypt_stat->key_size);
2154 ecryptfs_printk(KERN_DEBUG,
2155 "Cached session key " "encryption key: \n");
2156 if (ecryptfs_verbosity > 0)
2157 ecryptfs_dump_hex(session_key_encryption_key, 16);
2158 }
2159 if (unlikely(ecryptfs_verbosity > 0)) {
2160 ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n");
2161 ecryptfs_dump_hex(session_key_encryption_key, 16);
2162 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07002163 rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002164 src_sg, 2);
2165 if (rc < 1 || rc > 2) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002166 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
Michael Halcrowf4aad162007-10-16 01:27:53 -07002167 "for crypt_stat session key; expected rc = 1; "
2168 "got rc = [%d]. key_rec->enc_key_size = [%d]\n",
2169 rc, key_rec->enc_key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002170 rc = -ENOMEM;
2171 goto out;
2172 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07002173 rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002174 dst_sg, 2);
2175 if (rc < 1 || rc > 2) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002176 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
Michael Halcrowf4aad162007-10-16 01:27:53 -07002177 "for crypt_stat encrypted session key; "
2178 "expected rc = 1; got rc = [%d]. "
2179 "key_rec->enc_key_size = [%d]\n", rc,
2180 key_rec->enc_key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002181 rc = -ENOMEM;
2182 goto out;
2183 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002184 mutex_lock(tfm_mutex);
Michael Halcrow8bba0662006-10-30 22:07:18 -08002185 rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key,
2186 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002187 if (rc < 0) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002188 mutex_unlock(tfm_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -07002189 ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
Michael Halcrow8bba0662006-10-30 22:07:18 -08002190 "context; rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002191 goto out;
2192 }
2193 rc = 0;
2194 ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n",
2195 crypt_stat->key_size);
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002196 rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg,
Michael Halcrow8bba0662006-10-30 22:07:18 -08002197 (*key_rec).enc_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002198 mutex_unlock(tfm_mutex);
Michael Halcrow8bba0662006-10-30 22:07:18 -08002199 if (rc) {
2200 printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc);
2201 goto out;
2202 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002203 ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
Michael Halcrowf4aad162007-10-16 01:27:53 -07002204 if (ecryptfs_verbosity > 0) {
2205 ecryptfs_printk(KERN_DEBUG, "EFEK of size [%d]:\n",
2206 key_rec->enc_key_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002207 ecryptfs_dump_hex(key_rec->enc_key,
2208 key_rec->enc_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002209 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002210encrypted_session_key_set:
Michael Halcrow237fead2006-10-04 02:16:22 -07002211 /* This format is inspired by OpenPGP; see RFC 2440
2212 * packet tag 3 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002213 max_packet_size = (1 /* Tag 3 identifier */
2214 + 3 /* Max Tag 3 packet size */
2215 + 1 /* Version */
2216 + 1 /* Cipher code */
2217 + 1 /* S2K specifier */
2218 + 1 /* Hash identifier */
2219 + ECRYPTFS_SALT_SIZE /* Salt */
2220 + 1 /* Hash iterations */
2221 + key_rec->enc_key_size); /* Encrypted key size */
2222 if (max_packet_size > (*remaining_bytes)) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07002223 printk(KERN_ERR "Packet too large; need up to [%td] bytes, but "
2224 "there are only [%td] available\n", max_packet_size,
Michael Halcrowf4aad162007-10-16 01:27:53 -07002225 (*remaining_bytes));
2226 rc = -EINVAL;
2227 goto out;
2228 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002229 dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002230 /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3)
2231 * to get the number of octets in the actual Tag 3 packet */
Michael Halcrowf66e8832008-04-29 00:59:51 -07002232 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
2233 (max_packet_size - 4),
2234 &packet_size_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002235 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002236 printk(KERN_ERR "Error generating tag 3 packet header; cannot "
2237 "generate packet length. rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002238 goto out;
2239 }
2240 (*packet_size) += packet_size_length;
2241 dest[(*packet_size)++] = 0x04; /* version 4 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002242 /* TODO: Break from RFC2440 so that arbitrary ciphers can be
2243 * specified with strings */
Michael Halcrow9c79f342009-01-06 14:41:57 -08002244 cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher,
2245 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002246 if (cipher_code == 0) {
2247 ecryptfs_printk(KERN_WARNING, "Unable to generate code for "
2248 "cipher [%s]\n", crypt_stat->cipher);
2249 rc = -EINVAL;
2250 goto out;
2251 }
2252 dest[(*packet_size)++] = cipher_code;
2253 dest[(*packet_size)++] = 0x03; /* S2K */
2254 dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */
2255 memcpy(&dest[(*packet_size)], auth_tok->token.password.salt,
2256 ECRYPTFS_SALT_SIZE);
2257 (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */
2258 dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */
Michael Halcrowdddfa462007-02-12 00:53:44 -08002259 memcpy(&dest[(*packet_size)], key_rec->enc_key,
2260 key_rec->enc_key_size);
2261 (*packet_size) += key_rec->enc_key_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07002262out:
Michael Halcrow237fead2006-10-04 02:16:22 -07002263 if (rc)
2264 (*packet_size) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002265 else
2266 (*remaining_bytes) -= (*packet_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002267 return rc;
2268}
2269
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002270struct kmem_cache *ecryptfs_key_record_cache;
2271
Michael Halcrow237fead2006-10-04 02:16:22 -07002272/**
2273 * ecryptfs_generate_key_packet_set
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002274 * @dest_base: Virtual address from which to write the key record set
Michael Halcrow237fead2006-10-04 02:16:22 -07002275 * @crypt_stat: The cryptographic context from which the
2276 * authentication tokens will be retrieved
2277 * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat
2278 * for the global parameters
2279 * @len: The amount written
2280 * @max: The maximum amount of data allowed to be written
2281 *
2282 * Generates a key packet set and writes it to the virtual address
2283 * passed in.
2284 *
2285 * Returns zero on success; non-zero on error.
2286 */
2287int
2288ecryptfs_generate_key_packet_set(char *dest_base,
2289 struct ecryptfs_crypt_stat *crypt_stat,
2290 struct dentry *ecryptfs_dentry, size_t *len,
2291 size_t max)
2292{
Michael Halcrow237fead2006-10-04 02:16:22 -07002293 struct ecryptfs_auth_tok *auth_tok;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002294 struct ecryptfs_global_auth_tok *global_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07002295 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2296 &ecryptfs_superblock_to_private(
2297 ecryptfs_dentry->d_sb)->mount_crypt_stat;
2298 size_t written;
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002299 struct ecryptfs_key_record *key_rec;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002300 struct ecryptfs_key_sig *key_sig;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002301 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002302
2303 (*len) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002304 mutex_lock(&crypt_stat->keysig_list_mutex);
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002305 key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL);
2306 if (!key_rec) {
2307 rc = -ENOMEM;
2308 goto out;
2309 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002310 list_for_each_entry(key_sig, &crypt_stat->keysig_list,
2311 crypt_stat_list) {
2312 memset(key_rec, 0, sizeof(*key_rec));
2313 rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
2314 mount_crypt_stat,
2315 key_sig->keysig);
2316 if (rc) {
2317 printk(KERN_ERR "Error attempting to get the global "
2318 "auth_tok; rc = [%d]\n", rc);
2319 goto out_free;
2320 }
2321 if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) {
2322 printk(KERN_WARNING
2323 "Skipping invalid auth tok with sig = [%s]\n",
2324 global_auth_tok->sig);
2325 continue;
2326 }
2327 auth_tok = global_auth_tok->global_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07002328 if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
2329 rc = write_tag_3_packet((dest_base + (*len)),
Michael Halcrowf4aad162007-10-16 01:27:53 -07002330 &max, auth_tok,
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002331 crypt_stat, key_rec,
Michael Halcrow237fead2006-10-04 02:16:22 -07002332 &written);
2333 if (rc) {
2334 ecryptfs_printk(KERN_WARNING, "Error "
2335 "writing tag 3 packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002336 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002337 }
2338 (*len) += written;
2339 /* Write auth tok signature packet */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002340 rc = write_tag_11_packet((dest_base + (*len)), &max,
2341 key_rec->sig,
2342 ECRYPTFS_SIG_SIZE, &written);
Michael Halcrow237fead2006-10-04 02:16:22 -07002343 if (rc) {
2344 ecryptfs_printk(KERN_ERR, "Error writing "
2345 "auth tok signature packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002346 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002347 }
2348 (*len) += written;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002349 } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
2350 rc = write_tag_1_packet(dest_base + (*len),
Michael Halcrowf4aad162007-10-16 01:27:53 -07002351 &max, auth_tok,
2352 crypt_stat, key_rec, &written);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002353 if (rc) {
2354 ecryptfs_printk(KERN_WARNING, "Error "
2355 "writing tag 1 packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002356 goto out_free;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002357 }
2358 (*len) += written;
Michael Halcrow237fead2006-10-04 02:16:22 -07002359 } else {
2360 ecryptfs_printk(KERN_WARNING, "Unsupported "
2361 "authentication token type\n");
2362 rc = -EINVAL;
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002363 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002364 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002365 }
2366 if (likely(max > 0)) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002367 dest_base[(*len)] = 0x00;
2368 } else {
2369 ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n");
2370 rc = -EIO;
2371 }
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002372out_free:
2373 kmem_cache_free(ecryptfs_key_record_cache, key_rec);
Michael Halcrow237fead2006-10-04 02:16:22 -07002374out:
2375 if (rc)
2376 (*len) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002377 mutex_unlock(&crypt_stat->keysig_list_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -07002378 return rc;
2379}
Michael Halcrowf4aad162007-10-16 01:27:53 -07002380
2381struct kmem_cache *ecryptfs_key_sig_cache;
2382
2383int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig)
2384{
2385 struct ecryptfs_key_sig *new_key_sig;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002386
2387 new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL);
2388 if (!new_key_sig) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002389 printk(KERN_ERR
2390 "Error allocating from ecryptfs_key_sig_cache\n");
Roland Dreieraa061172009-07-01 15:48:18 -07002391 return -ENOMEM;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002392 }
2393 memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
Roland Dreieraa061172009-07-01 15:48:18 -07002394 /* Caller must hold keysig_list_mutex */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002395 list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
Roland Dreieraa061172009-07-01 15:48:18 -07002396
2397 return 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002398}
2399
2400struct kmem_cache *ecryptfs_global_auth_tok_cache;
2401
2402int
2403ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
Tyler Hicks84814d62009-03-13 13:51:59 -07002404 char *sig, u32 global_auth_tok_flags)
Michael Halcrowf4aad162007-10-16 01:27:53 -07002405{
2406 struct ecryptfs_global_auth_tok *new_auth_tok;
2407 int rc = 0;
2408
Eric Sandeen459e2162007-12-17 16:19:52 -08002409 new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache,
Michael Halcrowf4aad162007-10-16 01:27:53 -07002410 GFP_KERNEL);
2411 if (!new_auth_tok) {
2412 rc = -ENOMEM;
2413 printk(KERN_ERR "Error allocating from "
2414 "ecryptfs_global_auth_tok_cache\n");
2415 goto out;
2416 }
2417 memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX);
Tyler Hicks84814d62009-03-13 13:51:59 -07002418 new_auth_tok->flags = global_auth_tok_flags;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002419 new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
2420 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
2421 list_add(&new_auth_tok->mount_crypt_stat_list,
2422 &mount_crypt_stat->global_auth_tok_list);
2423 mount_crypt_stat->num_global_auth_toks++;
2424 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
2425out:
2426 return rc;
2427}
2428