blob: 259525c9abb8c0296f19fa3dc340b9ac29e70acd [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>
35#include "ecryptfs_kernel.h"
36
37/**
38 * request_key returned an error instead of a valid key address;
39 * determine the type of error, make appropriate log entries, and
40 * return an error code.
41 */
Michael Halcrowcd9d67d2007-10-16 01:28:04 -070042static int process_request_key_err(long err_code)
Michael Halcrow237fead2006-10-04 02:16:22 -070043{
44 int rc = 0;
45
46 switch (err_code) {
Eric Sandeen982363c2008-07-23 21:30:04 -070047 case -ENOKEY:
Michael Halcrow237fead2006-10-04 02:16:22 -070048 ecryptfs_printk(KERN_WARNING, "No key\n");
49 rc = -ENOENT;
50 break;
Eric Sandeen982363c2008-07-23 21:30:04 -070051 case -EKEYEXPIRED:
Michael Halcrow237fead2006-10-04 02:16:22 -070052 ecryptfs_printk(KERN_WARNING, "Key expired\n");
53 rc = -ETIME;
54 break;
Eric Sandeen982363c2008-07-23 21:30:04 -070055 case -EKEYREVOKED:
Michael Halcrow237fead2006-10-04 02:16:22 -070056 ecryptfs_printk(KERN_WARNING, "Key revoked\n");
57 rc = -EINVAL;
58 break;
59 default:
60 ecryptfs_printk(KERN_WARNING, "Unknown error code: "
61 "[0x%.16x]\n", err_code);
62 rc = -EINVAL;
63 }
64 return rc;
65}
66
Michael Halcrow237fead2006-10-04 02:16:22 -070067/**
Michael Halcrowf66e8832008-04-29 00:59:51 -070068 * ecryptfs_parse_packet_length
Michael Halcrow237fead2006-10-04 02:16:22 -070069 * @data: Pointer to memory containing length at offset
70 * @size: This function writes the decoded size to this memory
71 * address; zero on error
72 * @length_size: The number of bytes occupied by the encoded length
73 *
Michael Halcrow22e78fa2007-10-16 01:28:02 -070074 * Returns zero on success; non-zero on error
Michael Halcrow237fead2006-10-04 02:16:22 -070075 */
Michael Halcrowf66e8832008-04-29 00:59:51 -070076int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
77 size_t *length_size)
Michael Halcrow237fead2006-10-04 02:16:22 -070078{
79 int rc = 0;
80
81 (*length_size) = 0;
82 (*size) = 0;
83 if (data[0] < 192) {
84 /* One-byte length */
Michael Halcrowdddfa462007-02-12 00:53:44 -080085 (*size) = (unsigned char)data[0];
Michael Halcrow237fead2006-10-04 02:16:22 -070086 (*length_size) = 1;
87 } else if (data[0] < 224) {
88 /* Two-byte length */
Michael Halcrowdddfa462007-02-12 00:53:44 -080089 (*size) = (((unsigned char)(data[0]) - 192) * 256);
90 (*size) += ((unsigned char)(data[1]) + 192);
Michael Halcrow237fead2006-10-04 02:16:22 -070091 (*length_size) = 2;
92 } else if (data[0] == 255) {
93 /* Five-byte length; we're not supposed to see this */
94 ecryptfs_printk(KERN_ERR, "Five-byte packet length not "
95 "supported\n");
96 rc = -EINVAL;
97 goto out;
98 } else {
99 ecryptfs_printk(KERN_ERR, "Error parsing packet length\n");
100 rc = -EINVAL;
101 goto out;
102 }
103out:
104 return rc;
105}
106
107/**
Michael Halcrowf66e8832008-04-29 00:59:51 -0700108 * ecryptfs_write_packet_length
Michael Halcrow22e78fa2007-10-16 01:28:02 -0700109 * @dest: The byte array target into which to write the length. Must
110 * have at least 5 bytes allocated.
Michael Halcrow237fead2006-10-04 02:16:22 -0700111 * @size: The length to write.
Michael Halcrow22e78fa2007-10-16 01:28:02 -0700112 * @packet_size_length: The number of bytes used to encode the packet
113 * length is written to this address.
Michael Halcrow237fead2006-10-04 02:16:22 -0700114 *
115 * Returns zero on success; non-zero on error.
116 */
Michael Halcrowf66e8832008-04-29 00:59:51 -0700117int ecryptfs_write_packet_length(char *dest, size_t size,
118 size_t *packet_size_length)
Michael Halcrow237fead2006-10-04 02:16:22 -0700119{
120 int rc = 0;
121
122 if (size < 192) {
123 dest[0] = size;
124 (*packet_size_length) = 1;
125 } else if (size < 65536) {
126 dest[0] = (((size - 192) / 256) + 192);
127 dest[1] = ((size - 192) % 256);
128 (*packet_size_length) = 2;
129 } else {
130 rc = -EINVAL;
131 ecryptfs_printk(KERN_WARNING,
132 "Unsupported packet size: [%d]\n", size);
133 }
134 return rc;
135}
136
Michael Halcrowdddfa462007-02-12 00:53:44 -0800137static int
138write_tag_64_packet(char *signature, struct ecryptfs_session_key *session_key,
139 char **packet, size_t *packet_len)
140{
141 size_t i = 0;
142 size_t data_len;
143 size_t packet_size_len;
144 char *message;
145 int rc;
146
147 /*
148 * ***** TAG 64 Packet Format *****
149 * | Content Type | 1 byte |
150 * | Key Identifier Size | 1 or 2 bytes |
151 * | Key Identifier | arbitrary |
152 * | Encrypted File Encryption Key Size | 1 or 2 bytes |
153 * | Encrypted File Encryption Key | arbitrary |
154 */
155 data_len = (5 + ECRYPTFS_SIG_SIZE_HEX
156 + session_key->encrypted_key_size);
157 *packet = kmalloc(data_len, GFP_KERNEL);
158 message = *packet;
159 if (!message) {
160 ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
161 rc = -ENOMEM;
162 goto out;
163 }
164 message[i++] = ECRYPTFS_TAG_64_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700165 rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
166 &packet_size_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800167 if (rc) {
168 ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet "
169 "header; cannot generate packet length\n");
170 goto out;
171 }
172 i += packet_size_len;
173 memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX);
174 i += ECRYPTFS_SIG_SIZE_HEX;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700175 rc = ecryptfs_write_packet_length(&message[i],
176 session_key->encrypted_key_size,
177 &packet_size_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800178 if (rc) {
179 ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet "
180 "header; cannot generate packet length\n");
181 goto out;
182 }
183 i += packet_size_len;
184 memcpy(&message[i], session_key->encrypted_key,
185 session_key->encrypted_key_size);
186 i += session_key->encrypted_key_size;
187 *packet_len = i;
188out:
189 return rc;
190}
191
192static int
Trevor Highland19e66a62008-02-06 01:38:36 -0800193parse_tag_65_packet(struct ecryptfs_session_key *session_key, u8 *cipher_code,
Michael Halcrowdddfa462007-02-12 00:53:44 -0800194 struct ecryptfs_message *msg)
195{
196 size_t i = 0;
197 char *data;
198 size_t data_len;
199 size_t m_size;
200 size_t message_len;
201 u16 checksum = 0;
202 u16 expected_checksum = 0;
203 int rc;
204
205 /*
206 * ***** TAG 65 Packet Format *****
207 * | Content Type | 1 byte |
208 * | Status Indicator | 1 byte |
209 * | File Encryption Key Size | 1 or 2 bytes |
210 * | File Encryption Key | arbitrary |
211 */
212 message_len = msg->data_len;
213 data = msg->data;
214 if (message_len < 4) {
215 rc = -EIO;
216 goto out;
217 }
218 if (data[i++] != ECRYPTFS_TAG_65_PACKET_TYPE) {
219 ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_65\n");
220 rc = -EIO;
221 goto out;
222 }
223 if (data[i++]) {
224 ecryptfs_printk(KERN_ERR, "Status indicator has non-zero value "
225 "[%d]\n", data[i-1]);
226 rc = -EIO;
227 goto out;
228 }
Michael Halcrowf66e8832008-04-29 00:59:51 -0700229 rc = ecryptfs_parse_packet_length(&data[i], &m_size, &data_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800230 if (rc) {
231 ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
232 "rc = [%d]\n", rc);
233 goto out;
234 }
235 i += data_len;
236 if (message_len < (i + m_size)) {
Tyler Hicks624ae522008-10-15 22:02:51 -0700237 ecryptfs_printk(KERN_ERR, "The message received from ecryptfsd "
238 "is shorter than expected\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -0800239 rc = -EIO;
240 goto out;
241 }
242 if (m_size < 3) {
243 ecryptfs_printk(KERN_ERR,
244 "The decrypted key is not long enough to "
245 "include a cipher code and checksum\n");
246 rc = -EIO;
247 goto out;
248 }
249 *cipher_code = data[i++];
250 /* The decrypted key includes 1 byte cipher code and 2 byte checksum */
251 session_key->decrypted_key_size = m_size - 3;
252 if (session_key->decrypted_key_size > ECRYPTFS_MAX_KEY_BYTES) {
253 ecryptfs_printk(KERN_ERR, "key_size [%d] larger than "
254 "the maximum key size [%d]\n",
255 session_key->decrypted_key_size,
256 ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES);
257 rc = -EIO;
258 goto out;
259 }
260 memcpy(session_key->decrypted_key, &data[i],
261 session_key->decrypted_key_size);
262 i += session_key->decrypted_key_size;
263 expected_checksum += (unsigned char)(data[i++]) << 8;
264 expected_checksum += (unsigned char)(data[i++]);
265 for (i = 0; i < session_key->decrypted_key_size; i++)
266 checksum += session_key->decrypted_key[i];
267 if (expected_checksum != checksum) {
268 ecryptfs_printk(KERN_ERR, "Invalid checksum for file "
269 "encryption key; expected [%x]; calculated "
270 "[%x]\n", expected_checksum, checksum);
271 rc = -EIO;
272 }
273out:
274 return rc;
275}
276
277
278static int
Trevor Highland19e66a62008-02-06 01:38:36 -0800279write_tag_66_packet(char *signature, u8 cipher_code,
Michael Halcrowdddfa462007-02-12 00:53:44 -0800280 struct ecryptfs_crypt_stat *crypt_stat, char **packet,
281 size_t *packet_len)
282{
283 size_t i = 0;
284 size_t j;
285 size_t data_len;
286 size_t checksum = 0;
287 size_t packet_size_len;
288 char *message;
289 int rc;
290
291 /*
292 * ***** TAG 66 Packet Format *****
293 * | Content Type | 1 byte |
294 * | Key Identifier Size | 1 or 2 bytes |
295 * | Key Identifier | arbitrary |
296 * | File Encryption Key Size | 1 or 2 bytes |
297 * | File Encryption Key | arbitrary |
298 */
299 data_len = (5 + ECRYPTFS_SIG_SIZE_HEX + crypt_stat->key_size);
300 *packet = kmalloc(data_len, GFP_KERNEL);
301 message = *packet;
302 if (!message) {
303 ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
304 rc = -ENOMEM;
305 goto out;
306 }
307 message[i++] = ECRYPTFS_TAG_66_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700308 rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
309 &packet_size_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800310 if (rc) {
311 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet "
312 "header; cannot generate packet length\n");
313 goto out;
314 }
315 i += packet_size_len;
316 memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX);
317 i += ECRYPTFS_SIG_SIZE_HEX;
318 /* The encrypted key includes 1 byte cipher code and 2 byte checksum */
Michael Halcrowf66e8832008-04-29 00:59:51 -0700319 rc = ecryptfs_write_packet_length(&message[i], crypt_stat->key_size + 3,
320 &packet_size_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800321 if (rc) {
322 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet "
323 "header; cannot generate packet length\n");
324 goto out;
325 }
326 i += packet_size_len;
327 message[i++] = cipher_code;
328 memcpy(&message[i], crypt_stat->key, crypt_stat->key_size);
329 i += crypt_stat->key_size;
330 for (j = 0; j < crypt_stat->key_size; j++)
331 checksum += crypt_stat->key[j];
332 message[i++] = (checksum / 256) % 256;
333 message[i++] = (checksum % 256);
334 *packet_len = i;
335out:
336 return rc;
337}
338
339static int
340parse_tag_67_packet(struct ecryptfs_key_record *key_rec,
341 struct ecryptfs_message *msg)
342{
343 size_t i = 0;
344 char *data;
345 size_t data_len;
346 size_t message_len;
347 int rc;
348
349 /*
350 * ***** TAG 65 Packet Format *****
351 * | Content Type | 1 byte |
352 * | Status Indicator | 1 byte |
353 * | Encrypted File Encryption Key Size | 1 or 2 bytes |
354 * | Encrypted File Encryption Key | arbitrary |
355 */
356 message_len = msg->data_len;
357 data = msg->data;
358 /* verify that everything through the encrypted FEK size is present */
359 if (message_len < 4) {
360 rc = -EIO;
Michael Halcrowdf261c52009-01-06 14:42:02 -0800361 printk(KERN_ERR "%s: message_len is [%zd]; minimum acceptable "
Michael Halcrowf66e8832008-04-29 00:59:51 -0700362 "message length is [%d]\n", __func__, message_len, 4);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800363 goto out;
364 }
365 if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) {
Michael Halcrowdddfa462007-02-12 00:53:44 -0800366 rc = -EIO;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700367 printk(KERN_ERR "%s: Type should be ECRYPTFS_TAG_67\n",
368 __func__);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800369 goto out;
370 }
371 if (data[i++]) {
Michael Halcrowdddfa462007-02-12 00:53:44 -0800372 rc = -EIO;
Michael Halcrowf66e8832008-04-29 00:59:51 -0700373 printk(KERN_ERR "%s: Status indicator has non zero "
374 "value [%d]\n", __func__, data[i-1]);
375
Michael Halcrowdddfa462007-02-12 00:53:44 -0800376 goto out;
377 }
Michael Halcrowf66e8832008-04-29 00:59:51 -0700378 rc = ecryptfs_parse_packet_length(&data[i], &key_rec->enc_key_size,
379 &data_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800380 if (rc) {
381 ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
382 "rc = [%d]\n", rc);
383 goto out;
384 }
385 i += data_len;
386 if (message_len < (i + key_rec->enc_key_size)) {
Michael Halcrowdddfa462007-02-12 00:53:44 -0800387 rc = -EIO;
Michael Halcrowdf261c52009-01-06 14:42:02 -0800388 printk(KERN_ERR "%s: message_len [%zd]; max len is [%zd]\n",
Michael Halcrowf66e8832008-04-29 00:59:51 -0700389 __func__, message_len, (i + key_rec->enc_key_size));
Michael Halcrowdddfa462007-02-12 00:53:44 -0800390 goto out;
391 }
392 if (key_rec->enc_key_size > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
Michael Halcrowdddfa462007-02-12 00:53:44 -0800393 rc = -EIO;
Michael Halcrowdf261c52009-01-06 14:42:02 -0800394 printk(KERN_ERR "%s: Encrypted key_size [%zd] larger than "
Michael Halcrowf66e8832008-04-29 00:59:51 -0700395 "the maximum key size [%d]\n", __func__,
396 key_rec->enc_key_size,
397 ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES);
Michael Halcrowdddfa462007-02-12 00:53:44 -0800398 goto out;
399 }
400 memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size);
401out:
402 return rc;
403}
404
Michael Halcrowcd9d67d2007-10-16 01:28:04 -0700405static int
Michael Halcrow9c79f342009-01-06 14:41:57 -0800406ecryptfs_find_global_auth_tok_for_sig(
407 struct ecryptfs_global_auth_tok **global_auth_tok,
408 struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig)
409{
410 struct ecryptfs_global_auth_tok *walker;
411 int rc = 0;
412
413 (*global_auth_tok) = NULL;
414 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
415 list_for_each_entry(walker,
416 &mount_crypt_stat->global_auth_tok_list,
417 mount_crypt_stat_list) {
418 if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX) == 0) {
419 (*global_auth_tok) = walker;
420 goto out;
421 }
422 }
423 rc = -EINVAL;
424out:
425 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
426 return rc;
427}
428
429/**
430 * ecryptfs_find_auth_tok_for_sig
431 * @auth_tok: Set to the matching auth_tok; NULL if not found
432 * @crypt_stat: inode crypt_stat crypto context
433 * @sig: Sig of auth_tok to find
434 *
435 * For now, this function simply looks at the registered auth_tok's
436 * linked off the mount_crypt_stat, so all the auth_toks that can be
437 * used must be registered at mount time. This function could
438 * potentially try a lot harder to find auth_tok's (e.g., by calling
439 * out to ecryptfsd to dynamically retrieve an auth_tok object) so
440 * that static registration of auth_tok's will no longer be necessary.
441 *
442 * Returns zero on no error; non-zero on error
443 */
444static int
445ecryptfs_find_auth_tok_for_sig(
446 struct ecryptfs_auth_tok **auth_tok,
447 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
448 char *sig)
449{
450 struct ecryptfs_global_auth_tok *global_auth_tok;
451 int rc = 0;
452
453 (*auth_tok) = NULL;
454 if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
455 mount_crypt_stat, sig)) {
456 struct key *auth_tok_key;
457
458 rc = ecryptfs_keyring_auth_tok_for_sig(&auth_tok_key, auth_tok,
459 sig);
460 } else
461 (*auth_tok) = global_auth_tok->global_auth_tok;
462 return rc;
463}
464
465/**
466 * write_tag_70_packet can gobble a lot of stack space. We stuff most
467 * of the function's parameters in a kmalloc'd struct to help reduce
468 * eCryptfs' overall stack usage.
469 */
470struct ecryptfs_write_tag_70_packet_silly_stack {
471 u8 cipher_code;
472 size_t max_packet_size;
473 size_t packet_size_len;
474 size_t block_aligned_filename_size;
475 size_t block_size;
476 size_t i;
477 size_t j;
478 size_t num_rand_bytes;
479 struct mutex *tfm_mutex;
480 char *block_aligned_filename;
481 struct ecryptfs_auth_tok *auth_tok;
482 struct scatterlist src_sg;
483 struct scatterlist dst_sg;
484 struct blkcipher_desc desc;
485 char iv[ECRYPTFS_MAX_IV_BYTES];
486 char hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
487 char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
488 struct hash_desc hash_desc;
489 struct scatterlist hash_sg;
490};
491
492/**
493 * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK
494 * @filename: NULL-terminated filename string
495 *
496 * This is the simplest mechanism for achieving filename encryption in
497 * eCryptfs. It encrypts the given filename with the mount-wide
498 * filename encryption key (FNEK) and stores it in a packet to @dest,
499 * which the callee will encode and write directly into the dentry
500 * name.
501 */
502int
503ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
504 size_t *packet_size,
505 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
506 char *filename, size_t filename_size)
507{
508 struct ecryptfs_write_tag_70_packet_silly_stack *s;
509 int rc = 0;
510
511 s = kmalloc(sizeof(*s), GFP_KERNEL);
512 if (!s) {
513 printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
Michael Halcrowdf261c52009-01-06 14:42:02 -0800514 "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
Michael Halcrow9c79f342009-01-06 14:41:57 -0800515 goto out;
516 }
517 s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
518 (*packet_size) = 0;
519 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(
520 &s->desc.tfm,
521 &s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name);
522 if (unlikely(rc)) {
523 printk(KERN_ERR "Internal error whilst attempting to get "
524 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
525 mount_crypt_stat->global_default_fn_cipher_name, rc);
526 goto out;
527 }
528 mutex_lock(s->tfm_mutex);
529 s->block_size = crypto_blkcipher_blocksize(s->desc.tfm);
530 /* Plus one for the \0 separator between the random prefix
531 * and the plaintext filename */
532 s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1);
533 s->block_aligned_filename_size = (s->num_rand_bytes + filename_size);
534 if ((s->block_aligned_filename_size % s->block_size) != 0) {
535 s->num_rand_bytes += (s->block_size
536 - (s->block_aligned_filename_size
537 % s->block_size));
538 s->block_aligned_filename_size = (s->num_rand_bytes
539 + filename_size);
540 }
541 /* Octet 0: Tag 70 identifier
542 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
543 * and block-aligned encrypted filename size)
544 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
545 * Octet N2-N3: Cipher identifier (1 octet)
546 * Octets N3-N4: Block-aligned encrypted filename
547 * - Consists of a minimum number of random characters, a \0
548 * separator, and then the filename */
549 s->max_packet_size = (1 /* Tag 70 identifier */
550 + 3 /* Max Tag 70 packet size */
551 + ECRYPTFS_SIG_SIZE /* FNEK sig */
552 + 1 /* Cipher identifier */
553 + s->block_aligned_filename_size);
554 if (dest == NULL) {
555 (*packet_size) = s->max_packet_size;
556 goto out_unlock;
557 }
558 if (s->max_packet_size > (*remaining_bytes)) {
Michael Halcrowa8f12862009-01-06 14:42:03 -0800559 printk(KERN_WARNING "%s: Require [%zd] bytes to write; only "
560 "[%zd] available\n", __func__, s->max_packet_size,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800561 (*remaining_bytes));
562 rc = -EINVAL;
563 goto out_unlock;
564 }
565 s->block_aligned_filename = kzalloc(s->block_aligned_filename_size,
566 GFP_KERNEL);
567 if (!s->block_aligned_filename) {
568 printk(KERN_ERR "%s: Out of kernel memory whilst attempting to "
Michael Halcrowdf261c52009-01-06 14:42:02 -0800569 "kzalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800570 s->block_aligned_filename_size);
571 rc = -ENOMEM;
572 goto out_unlock;
573 }
574 s->i = 0;
575 dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE;
576 rc = ecryptfs_write_packet_length(&dest[s->i],
577 (ECRYPTFS_SIG_SIZE
578 + 1 /* Cipher code */
579 + s->block_aligned_filename_size),
580 &s->packet_size_len);
581 if (rc) {
582 printk(KERN_ERR "%s: Error generating tag 70 packet "
583 "header; cannot generate packet length; rc = [%d]\n",
584 __func__, rc);
585 goto out_free_unlock;
586 }
587 s->i += s->packet_size_len;
588 ecryptfs_from_hex(&dest[s->i],
589 mount_crypt_stat->global_default_fnek_sig,
590 ECRYPTFS_SIG_SIZE);
591 s->i += ECRYPTFS_SIG_SIZE;
592 s->cipher_code = ecryptfs_code_for_cipher_string(
593 mount_crypt_stat->global_default_fn_cipher_name,
594 mount_crypt_stat->global_default_fn_cipher_key_bytes);
595 if (s->cipher_code == 0) {
596 printk(KERN_WARNING "%s: Unable to generate code for "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800597 "cipher [%s] with key bytes [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800598 mount_crypt_stat->global_default_fn_cipher_name,
599 mount_crypt_stat->global_default_fn_cipher_key_bytes);
600 rc = -EINVAL;
601 goto out_free_unlock;
602 }
603 dest[s->i++] = s->cipher_code;
604 rc = ecryptfs_find_auth_tok_for_sig(
605 &s->auth_tok, mount_crypt_stat,
606 mount_crypt_stat->global_default_fnek_sig);
607 if (rc) {
608 printk(KERN_ERR "%s: Error attempting to find auth tok for "
609 "fnek sig [%s]; rc = [%d]\n", __func__,
610 mount_crypt_stat->global_default_fnek_sig, rc);
611 goto out_free_unlock;
612 }
613 /* TODO: Support other key modules than passphrase for
614 * filename encryption */
615 BUG_ON(s->auth_tok->token_type != ECRYPTFS_PASSWORD);
616 sg_init_one(
617 &s->hash_sg,
618 (u8 *)s->auth_tok->token.password.session_key_encryption_key,
619 s->auth_tok->token.password.session_key_encryption_key_bytes);
620 s->hash_desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
621 s->hash_desc.tfm = crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST, 0,
622 CRYPTO_ALG_ASYNC);
623 if (IS_ERR(s->hash_desc.tfm)) {
624 rc = PTR_ERR(s->hash_desc.tfm);
625 printk(KERN_ERR "%s: Error attempting to "
626 "allocate hash crypto context; rc = [%d]\n",
627 __func__, rc);
628 goto out_free_unlock;
629 }
630 rc = crypto_hash_init(&s->hash_desc);
631 if (rc) {
632 printk(KERN_ERR
633 "%s: Error initializing crypto hash; rc = [%d]\n",
634 __func__, rc);
635 goto out_release_free_unlock;
636 }
637 rc = crypto_hash_update(
638 &s->hash_desc, &s->hash_sg,
639 s->auth_tok->token.password.session_key_encryption_key_bytes);
640 if (rc) {
641 printk(KERN_ERR
642 "%s: Error updating crypto hash; rc = [%d]\n",
643 __func__, rc);
644 goto out_release_free_unlock;
645 }
646 rc = crypto_hash_final(&s->hash_desc, s->hash);
647 if (rc) {
648 printk(KERN_ERR
649 "%s: Error finalizing crypto hash; rc = [%d]\n",
650 __func__, rc);
651 goto out_release_free_unlock;
652 }
653 for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) {
654 s->block_aligned_filename[s->j] =
655 s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)];
656 if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)
657 == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) {
658 sg_init_one(&s->hash_sg, (u8 *)s->hash,
659 ECRYPTFS_TAG_70_DIGEST_SIZE);
660 rc = crypto_hash_init(&s->hash_desc);
661 if (rc) {
662 printk(KERN_ERR
663 "%s: Error initializing crypto hash; "
664 "rc = [%d]\n", __func__, rc);
665 goto out_release_free_unlock;
666 }
667 rc = crypto_hash_update(&s->hash_desc, &s->hash_sg,
668 ECRYPTFS_TAG_70_DIGEST_SIZE);
669 if (rc) {
670 printk(KERN_ERR
671 "%s: Error updating crypto hash; "
672 "rc = [%d]\n", __func__, rc);
673 goto out_release_free_unlock;
674 }
675 rc = crypto_hash_final(&s->hash_desc, s->tmp_hash);
676 if (rc) {
677 printk(KERN_ERR
678 "%s: Error finalizing crypto hash; "
679 "rc = [%d]\n", __func__, rc);
680 goto out_release_free_unlock;
681 }
682 memcpy(s->hash, s->tmp_hash,
683 ECRYPTFS_TAG_70_DIGEST_SIZE);
684 }
685 if (s->block_aligned_filename[s->j] == '\0')
686 s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL;
687 }
688 memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename,
689 filename_size);
690 rc = virt_to_scatterlist(s->block_aligned_filename,
691 s->block_aligned_filename_size, &s->src_sg, 1);
692 if (rc != 1) {
693 printk(KERN_ERR "%s: Internal error whilst attempting to "
694 "convert filename memory to scatterlist; "
695 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800696 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800697 s->block_aligned_filename_size);
698 goto out_release_free_unlock;
699 }
700 rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size,
701 &s->dst_sg, 1);
702 if (rc != 1) {
703 printk(KERN_ERR "%s: Internal error whilst attempting to "
704 "convert encrypted filename memory to scatterlist; "
705 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800706 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800707 s->block_aligned_filename_size);
708 goto out_release_free_unlock;
709 }
710 /* The characters in the first block effectively do the job
711 * of the IV here, so we just use 0's for the IV. Note the
712 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
713 * >= ECRYPTFS_MAX_IV_BYTES. */
714 memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
715 s->desc.info = s->iv;
716 rc = crypto_blkcipher_setkey(
717 s->desc.tfm,
718 s->auth_tok->token.password.session_key_encryption_key,
719 mount_crypt_stat->global_default_fn_cipher_key_bytes);
720 if (rc < 0) {
721 printk(KERN_ERR "%s: Error setting key for crypto context; "
722 "rc = [%d]. s->auth_tok->token.password.session_key_"
723 "encryption_key = [0x%p]; mount_crypt_stat->"
Michael Halcrowdf261c52009-01-06 14:42:02 -0800724 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800725 rc,
726 s->auth_tok->token.password.session_key_encryption_key,
727 mount_crypt_stat->global_default_fn_cipher_key_bytes);
728 goto out_release_free_unlock;
729 }
730 rc = crypto_blkcipher_encrypt_iv(&s->desc, &s->dst_sg, &s->src_sg,
731 s->block_aligned_filename_size);
732 if (rc) {
733 printk(KERN_ERR "%s: Error attempting to encrypt filename; "
734 "rc = [%d]\n", __func__, rc);
735 goto out_release_free_unlock;
736 }
737 s->i += s->block_aligned_filename_size;
738 (*packet_size) = s->i;
739 (*remaining_bytes) -= (*packet_size);
740out_release_free_unlock:
741 crypto_free_hash(s->hash_desc.tfm);
742out_free_unlock:
Johannes Weiner00fcf2c2009-03-31 15:24:42 -0700743 kzfree(s->block_aligned_filename);
Michael Halcrow9c79f342009-01-06 14:41:57 -0800744out_unlock:
745 mutex_unlock(s->tfm_mutex);
746out:
747 kfree(s);
748 return rc;
749}
750
751struct ecryptfs_parse_tag_70_packet_silly_stack {
752 u8 cipher_code;
753 size_t max_packet_size;
754 size_t packet_size_len;
755 size_t parsed_tag_70_packet_size;
756 size_t block_aligned_filename_size;
757 size_t block_size;
758 size_t i;
759 struct mutex *tfm_mutex;
760 char *decrypted_filename;
761 struct ecryptfs_auth_tok *auth_tok;
762 struct scatterlist src_sg;
763 struct scatterlist dst_sg;
764 struct blkcipher_desc desc;
765 char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1];
766 char iv[ECRYPTFS_MAX_IV_BYTES];
767 char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE];
768};
769
770/**
771 * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet
772 * @filename: This function kmalloc's the memory for the filename
Michael Halcrow7d8bc2b2009-01-06 14:42:04 -0800773 * @filename_size: This function sets this to the amount of memory
774 * kmalloc'd for the filename
775 * @packet_size: This function sets this to the the number of octets
776 * in the packet parsed
777 * @mount_crypt_stat: The mount-wide cryptographic context
778 * @data: The memory location containing the start of the tag 70
779 * packet
780 * @max_packet_size: The maximum legal size of the packet to be parsed
781 * from @data
782 *
783 * Returns zero on success; non-zero otherwise
Michael Halcrow9c79f342009-01-06 14:41:57 -0800784 */
785int
786ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
787 size_t *packet_size,
788 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
789 char *data, size_t max_packet_size)
790{
791 struct ecryptfs_parse_tag_70_packet_silly_stack *s;
792 int rc = 0;
793
794 (*packet_size) = 0;
795 (*filename_size) = 0;
796 (*filename) = NULL;
797 s = kmalloc(sizeof(*s), GFP_KERNEL);
798 if (!s) {
799 printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800800 "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
Michael Halcrow9c79f342009-01-06 14:41:57 -0800801 goto out;
802 }
803 s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
804 if (max_packet_size < (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)) {
Michael Halcrowdf261c52009-01-06 14:42:02 -0800805 printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be "
Michael Halcrow9c79f342009-01-06 14:41:57 -0800806 "at least [%d]\n", __func__, max_packet_size,
807 (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1));
808 rc = -EINVAL;
809 goto out;
810 }
811 /* Octet 0: Tag 70 identifier
812 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
813 * and block-aligned encrypted filename size)
814 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
815 * Octet N2-N3: Cipher identifier (1 octet)
816 * Octets N3-N4: Block-aligned encrypted filename
817 * - Consists of a minimum number of random numbers, a \0
818 * separator, and then the filename */
819 if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) {
820 printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be "
821 "tag [0x%.2x]\n", __func__,
822 data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE);
823 rc = -EINVAL;
824 goto out;
825 }
826 rc = ecryptfs_parse_packet_length(&data[(*packet_size)],
827 &s->parsed_tag_70_packet_size,
828 &s->packet_size_len);
829 if (rc) {
830 printk(KERN_WARNING "%s: Error parsing packet length; "
831 "rc = [%d]\n", __func__, rc);
832 goto out;
833 }
834 s->block_aligned_filename_size = (s->parsed_tag_70_packet_size
835 - ECRYPTFS_SIG_SIZE - 1);
836 if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size)
837 > max_packet_size) {
Michael Halcrowa8f12862009-01-06 14:42:03 -0800838 printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet "
839 "size is [%zd]\n", __func__, max_packet_size,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800840 (1 + s->packet_size_len + 1
841 + s->block_aligned_filename_size));
842 rc = -EINVAL;
843 goto out;
844 }
845 (*packet_size) += s->packet_size_len;
846 ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)],
847 ECRYPTFS_SIG_SIZE);
848 s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0';
849 (*packet_size) += ECRYPTFS_SIG_SIZE;
850 s->cipher_code = data[(*packet_size)++];
851 rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code);
852 if (rc) {
853 printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n",
854 __func__, s->cipher_code);
855 goto out;
856 }
857 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm,
858 &s->tfm_mutex,
859 s->cipher_string);
860 if (unlikely(rc)) {
861 printk(KERN_ERR "Internal error whilst attempting to get "
862 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
863 s->cipher_string, rc);
864 goto out;
865 }
866 mutex_lock(s->tfm_mutex);
867 rc = virt_to_scatterlist(&data[(*packet_size)],
868 s->block_aligned_filename_size, &s->src_sg, 1);
869 if (rc != 1) {
870 printk(KERN_ERR "%s: Internal error whilst attempting to "
871 "convert encrypted filename memory to scatterlist; "
872 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800873 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800874 s->block_aligned_filename_size);
875 goto out_unlock;
876 }
877 (*packet_size) += s->block_aligned_filename_size;
878 s->decrypted_filename = kmalloc(s->block_aligned_filename_size,
879 GFP_KERNEL);
880 if (!s->decrypted_filename) {
881 printk(KERN_ERR "%s: Out of memory whilst attempting to "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800882 "kmalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800883 s->block_aligned_filename_size);
884 rc = -ENOMEM;
885 goto out_unlock;
886 }
887 rc = virt_to_scatterlist(s->decrypted_filename,
888 s->block_aligned_filename_size, &s->dst_sg, 1);
889 if (rc != 1) {
890 printk(KERN_ERR "%s: Internal error whilst attempting to "
891 "convert decrypted filename memory to scatterlist; "
892 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800893 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800894 s->block_aligned_filename_size);
895 goto out_free_unlock;
896 }
897 /* The characters in the first block effectively do the job of
898 * the IV here, so we just use 0's for the IV. Note the
899 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
900 * >= ECRYPTFS_MAX_IV_BYTES. */
901 memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
902 s->desc.info = s->iv;
903 rc = ecryptfs_find_auth_tok_for_sig(&s->auth_tok, mount_crypt_stat,
904 s->fnek_sig_hex);
905 if (rc) {
906 printk(KERN_ERR "%s: Error attempting to find auth tok for "
907 "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex,
908 rc);
909 goto out_free_unlock;
910 }
911 /* TODO: Support other key modules than passphrase for
912 * filename encryption */
913 BUG_ON(s->auth_tok->token_type != ECRYPTFS_PASSWORD);
914 rc = crypto_blkcipher_setkey(
915 s->desc.tfm,
916 s->auth_tok->token.password.session_key_encryption_key,
917 mount_crypt_stat->global_default_fn_cipher_key_bytes);
918 if (rc < 0) {
919 printk(KERN_ERR "%s: Error setting key for crypto context; "
920 "rc = [%d]. s->auth_tok->token.password.session_key_"
921 "encryption_key = [0x%p]; mount_crypt_stat->"
Michael Halcrowdf261c52009-01-06 14:42:02 -0800922 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800923 rc,
924 s->auth_tok->token.password.session_key_encryption_key,
925 mount_crypt_stat->global_default_fn_cipher_key_bytes);
926 goto out_free_unlock;
927 }
928 rc = crypto_blkcipher_decrypt_iv(&s->desc, &s->dst_sg, &s->src_sg,
929 s->block_aligned_filename_size);
930 if (rc) {
931 printk(KERN_ERR "%s: Error attempting to decrypt filename; "
932 "rc = [%d]\n", __func__, rc);
933 goto out_free_unlock;
934 }
935 s->i = 0;
936 while (s->decrypted_filename[s->i] != '\0'
937 && s->i < s->block_aligned_filename_size)
938 s->i++;
939 if (s->i == s->block_aligned_filename_size) {
940 printk(KERN_WARNING "%s: Invalid tag 70 packet; could not "
941 "find valid separator between random characters and "
942 "the filename\n", __func__);
943 rc = -EINVAL;
944 goto out_free_unlock;
945 }
946 s->i++;
947 (*filename_size) = (s->block_aligned_filename_size - s->i);
948 if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) {
Michael Halcrowdf261c52009-01-06 14:42:02 -0800949 printk(KERN_WARNING "%s: Filename size is [%zd], which is "
Michael Halcrow9c79f342009-01-06 14:41:57 -0800950 "invalid\n", __func__, (*filename_size));
951 rc = -EINVAL;
952 goto out_free_unlock;
953 }
954 (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL);
955 if (!(*filename)) {
956 printk(KERN_ERR "%s: Out of memory whilst attempting to "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800957 "kmalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800958 ((*filename_size) + 1));
959 rc = -ENOMEM;
960 goto out_free_unlock;
961 }
962 memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size));
963 (*filename)[(*filename_size)] = '\0';
964out_free_unlock:
965 kfree(s->decrypted_filename);
966out_unlock:
967 mutex_unlock(s->tfm_mutex);
968out:
969 if (rc) {
970 (*packet_size) = 0;
971 (*filename_size) = 0;
972 (*filename) = NULL;
973 }
974 kfree(s);
975 return rc;
976}
977
978static int
Michael Halcrowcd9d67d2007-10-16 01:28:04 -0700979ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok)
980{
981 int rc = 0;
982
983 (*sig) = NULL;
984 switch (auth_tok->token_type) {
985 case ECRYPTFS_PASSWORD:
986 (*sig) = auth_tok->token.password.signature;
987 break;
988 case ECRYPTFS_PRIVATE_KEY:
989 (*sig) = auth_tok->token.private_key.signature;
990 break;
991 default:
992 printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n",
993 auth_tok->token_type);
994 rc = -EINVAL;
995 }
996 return rc;
997}
998
Michael Halcrowdddfa462007-02-12 00:53:44 -0800999/**
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001000 * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok.
1001 * @auth_tok: The key authentication token used to decrypt the session key
1002 * @crypt_stat: The cryptographic context
Michael Halcrowdddfa462007-02-12 00:53:44 -08001003 *
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001004 * Returns zero on success; non-zero error otherwise.
Michael Halcrowdddfa462007-02-12 00:53:44 -08001005 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07001006static int
1007decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1008 struct ecryptfs_crypt_stat *crypt_stat)
Michael Halcrowdddfa462007-02-12 00:53:44 -08001009{
Trevor Highland19e66a62008-02-06 01:38:36 -08001010 u8 cipher_code = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001011 struct ecryptfs_msg_ctx *msg_ctx;
1012 struct ecryptfs_message *msg = NULL;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001013 char *auth_tok_sig;
Tyler Hicks624ae522008-10-15 22:02:51 -07001014 char *payload;
1015 size_t payload_len;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001016 int rc;
1017
Michael Halcrow5dda6992007-10-16 01:28:06 -07001018 rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok);
1019 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001020 printk(KERN_ERR "Unrecognized auth tok type: [%d]\n",
1021 auth_tok->token_type);
1022 goto out;
1023 }
1024 rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key),
Tyler Hicks624ae522008-10-15 22:02:51 -07001025 &payload, &payload_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001026 if (rc) {
Michael Halcrowf66e8832008-04-29 00:59:51 -07001027 ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001028 goto out;
1029 }
Tyler Hicks624ae522008-10-15 22:02:51 -07001030 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001031 if (rc) {
Tyler Hicks624ae522008-10-15 22:02:51 -07001032 ecryptfs_printk(KERN_ERR, "Error sending message to "
1033 "ecryptfsd\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001034 goto out;
1035 }
1036 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1037 if (rc) {
1038 ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet "
1039 "from the user space daemon\n");
1040 rc = -EIO;
1041 goto out;
1042 }
1043 rc = parse_tag_65_packet(&(auth_tok->session_key),
1044 &cipher_code, msg);
1045 if (rc) {
1046 printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n",
1047 rc);
1048 goto out;
1049 }
1050 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1051 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1052 auth_tok->session_key.decrypted_key_size);
1053 crypt_stat->key_size = auth_tok->session_key.decrypted_key_size;
1054 rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code);
1055 if (rc) {
1056 ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n",
1057 cipher_code)
1058 goto out;
1059 }
1060 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1061 if (ecryptfs_verbosity > 0) {
1062 ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n");
1063 ecryptfs_dump_hex(crypt_stat->key,
1064 crypt_stat->key_size);
1065 }
1066out:
1067 if (msg)
1068 kfree(msg);
1069 return rc;
1070}
1071
1072static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
1073{
Michael Halcrowdddfa462007-02-12 00:53:44 -08001074 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
Michael Halcrowe0869cc2007-10-16 01:27:55 -07001075 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001076
Michael Halcrowe0869cc2007-10-16 01:27:55 -07001077 list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp,
1078 auth_tok_list_head, list) {
1079 list_del(&auth_tok_list_item->list);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001080 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1081 auth_tok_list_item);
1082 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001083}
1084
1085struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
1086
Michael Halcrowdddfa462007-02-12 00:53:44 -08001087/**
1088 * parse_tag_1_packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001089 * @crypt_stat: The cryptographic context to modify based on packet contents
Michael Halcrowdddfa462007-02-12 00:53:44 -08001090 * @data: The raw bytes of the packet.
1091 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001092 * a new authentication token will be placed at the
1093 * end of this list for this packet.
Michael Halcrowdddfa462007-02-12 00:53:44 -08001094 * @new_auth_tok: Pointer to a pointer to memory that this function
1095 * allocates; sets the memory address of the pointer to
1096 * NULL on error. This object is added to the
1097 * auth_tok_list.
1098 * @packet_size: This function writes the size of the parsed packet
1099 * into this memory location; zero on error.
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001100 * @max_packet_size: The maximum allowable packet size
Michael Halcrowdddfa462007-02-12 00:53:44 -08001101 *
1102 * Returns zero on success; non-zero on error.
1103 */
1104static int
1105parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
1106 unsigned char *data, struct list_head *auth_tok_list,
1107 struct ecryptfs_auth_tok **new_auth_tok,
1108 size_t *packet_size, size_t max_packet_size)
1109{
1110 size_t body_size;
1111 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1112 size_t length_size;
1113 int rc = 0;
1114
1115 (*packet_size) = 0;
1116 (*new_auth_tok) = NULL;
Michael Halcrow132181792007-10-16 01:27:56 -07001117 /**
1118 * This format is inspired by OpenPGP; see RFC 2440
1119 * packet tag 1
1120 *
1121 * Tag 1 identifier (1 byte)
1122 * Max Tag 1 packet size (max 3 bytes)
1123 * Version (1 byte)
1124 * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE)
1125 * Cipher identifier (1 byte)
1126 * Encrypted key size (arbitrary)
1127 *
1128 * 12 bytes minimum packet size
Michael Halcrowdddfa462007-02-12 00:53:44 -08001129 */
Michael Halcrow132181792007-10-16 01:27:56 -07001130 if (unlikely(max_packet_size < 12)) {
1131 printk(KERN_ERR "Invalid max packet size; must be >=12\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001132 rc = -EINVAL;
1133 goto out;
1134 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001135 if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) {
Michael Halcrow132181792007-10-16 01:27:56 -07001136 printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n",
1137 ECRYPTFS_TAG_1_PACKET_TYPE);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001138 rc = -EINVAL;
1139 goto out;
1140 }
1141 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1142 * at end of function upon failure */
1143 auth_tok_list_item =
Michael Halcrow132181792007-10-16 01:27:56 -07001144 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache,
1145 GFP_KERNEL);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001146 if (!auth_tok_list_item) {
Michael Halcrow132181792007-10-16 01:27:56 -07001147 printk(KERN_ERR "Unable to allocate memory\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001148 rc = -ENOMEM;
1149 goto out;
1150 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001151 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001152 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1153 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001154 if (rc) {
Michael Halcrow132181792007-10-16 01:27:56 -07001155 printk(KERN_WARNING "Error parsing packet length; "
1156 "rc = [%d]\n", rc);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001157 goto out_free;
1158 }
Michael Halcrow132181792007-10-16 01:27:56 -07001159 if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001160 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001161 rc = -EINVAL;
1162 goto out_free;
1163 }
1164 (*packet_size) += length_size;
1165 if (unlikely((*packet_size) + body_size > max_packet_size)) {
Michael Halcrow132181792007-10-16 01:27:56 -07001166 printk(KERN_WARNING "Packet size exceeds max\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001167 rc = -EINVAL;
1168 goto out_free;
1169 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001170 if (unlikely(data[(*packet_size)++] != 0x03)) {
Michael Halcrow132181792007-10-16 01:27:56 -07001171 printk(KERN_WARNING "Unknown version number [%d]\n",
1172 data[(*packet_size) - 1]);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001173 rc = -EINVAL;
1174 goto out_free;
1175 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001176 ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
1177 &data[(*packet_size)], ECRYPTFS_SIG_SIZE);
1178 *packet_size += ECRYPTFS_SIG_SIZE;
1179 /* This byte is skipped because the kernel does not need to
1180 * know which public key encryption algorithm was used */
1181 (*packet_size)++;
1182 (*new_auth_tok)->session_key.encrypted_key_size =
Michael Halcrow132181792007-10-16 01:27:56 -07001183 body_size - (ECRYPTFS_SIG_SIZE + 2);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001184 if ((*new_auth_tok)->session_key.encrypted_key_size
1185 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
Michael Halcrow132181792007-10-16 01:27:56 -07001186 printk(KERN_WARNING "Tag 1 packet contains key larger "
1187 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001188 rc = -EINVAL;
1189 goto out;
1190 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001191 memcpy((*new_auth_tok)->session_key.encrypted_key,
Michael Halcrow132181792007-10-16 01:27:56 -07001192 &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2)));
Michael Halcrowdddfa462007-02-12 00:53:44 -08001193 (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size;
1194 (*new_auth_tok)->session_key.flags &=
1195 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1196 (*new_auth_tok)->session_key.flags |=
1197 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
1198 (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY;
Michael Halcrow132181792007-10-16 01:27:56 -07001199 (*new_auth_tok)->flags = 0;
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001200 (*new_auth_tok)->session_key.flags &=
1201 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1202 (*new_auth_tok)->session_key.flags &=
1203 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001204 list_add(&auth_tok_list_item->list, auth_tok_list);
1205 goto out;
1206out_free:
1207 (*new_auth_tok) = NULL;
1208 memset(auth_tok_list_item, 0,
1209 sizeof(struct ecryptfs_auth_tok_list_item));
1210 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1211 auth_tok_list_item);
1212out:
1213 if (rc)
1214 (*packet_size) = 0;
1215 return rc;
1216}
1217
Michael Halcrow237fead2006-10-04 02:16:22 -07001218/**
1219 * parse_tag_3_packet
1220 * @crypt_stat: The cryptographic context to modify based on packet
1221 * contents.
1222 * @data: The raw bytes of the packet.
1223 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
1224 * a new authentication token will be placed at the end
1225 * of this list for this packet.
1226 * @new_auth_tok: Pointer to a pointer to memory that this function
1227 * allocates; sets the memory address of the pointer to
1228 * NULL on error. This object is added to the
1229 * auth_tok_list.
1230 * @packet_size: This function writes the size of the parsed packet
1231 * into this memory location; zero on error.
1232 * @max_packet_size: maximum number of bytes to parse
1233 *
1234 * Returns zero on success; non-zero on error.
1235 */
1236static int
1237parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
1238 unsigned char *data, struct list_head *auth_tok_list,
1239 struct ecryptfs_auth_tok **new_auth_tok,
1240 size_t *packet_size, size_t max_packet_size)
1241{
Michael Halcrow237fead2006-10-04 02:16:22 -07001242 size_t body_size;
1243 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1244 size_t length_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001245 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001246
1247 (*packet_size) = 0;
1248 (*new_auth_tok) = NULL;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001249 /**
1250 *This format is inspired by OpenPGP; see RFC 2440
1251 * packet tag 3
1252 *
1253 * Tag 3 identifier (1 byte)
1254 * Max Tag 3 packet size (max 3 bytes)
1255 * Version (1 byte)
1256 * Cipher code (1 byte)
1257 * S2K specifier (1 byte)
1258 * Hash identifier (1 byte)
1259 * Salt (ECRYPTFS_SALT_SIZE)
1260 * Hash iterations (1 byte)
1261 * Encrypted key (arbitrary)
1262 *
1263 * (ECRYPTFS_SALT_SIZE + 7) minimum packet size
Michael Halcrow237fead2006-10-04 02:16:22 -07001264 */
Michael Halcrowc59becf2007-10-16 01:27:56 -07001265 if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) {
1266 printk(KERN_ERR "Max packet size too large\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001267 rc = -EINVAL;
1268 goto out;
1269 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001270 if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001271 printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n",
1272 ECRYPTFS_TAG_3_PACKET_TYPE);
Michael Halcrow237fead2006-10-04 02:16:22 -07001273 rc = -EINVAL;
1274 goto out;
1275 }
1276 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1277 * at end of function upon failure */
1278 auth_tok_list_item =
Robert P. J. Dayc3762222007-02-10 01:45:03 -08001279 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
Michael Halcrow237fead2006-10-04 02:16:22 -07001280 if (!auth_tok_list_item) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001281 printk(KERN_ERR "Unable to allocate memory\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001282 rc = -ENOMEM;
1283 goto out;
1284 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001285 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001286 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1287 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001288 if (rc) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001289 printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n",
1290 rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07001291 goto out_free;
1292 }
Michael Halcrowc59becf2007-10-16 01:27:56 -07001293 if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001294 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001295 rc = -EINVAL;
1296 goto out_free;
1297 }
1298 (*packet_size) += length_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07001299 if (unlikely((*packet_size) + body_size > max_packet_size)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001300 printk(KERN_ERR "Packet size exceeds max\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001301 rc = -EINVAL;
1302 goto out_free;
1303 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001304 (*new_auth_tok)->session_key.encrypted_key_size =
Michael Halcrowc59becf2007-10-16 01:27:56 -07001305 (body_size - (ECRYPTFS_SALT_SIZE + 5));
Ramon de Carvalho Vallef151cd22009-07-28 13:58:22 -05001306 if ((*new_auth_tok)->session_key.encrypted_key_size
1307 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
1308 printk(KERN_WARNING "Tag 3 packet contains key larger "
1309 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n");
1310 rc = -EINVAL;
1311 goto out_free;
1312 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001313 if (unlikely(data[(*packet_size)++] != 0x04)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001314 printk(KERN_WARNING "Unknown version number [%d]\n",
1315 data[(*packet_size) - 1]);
Michael Halcrow237fead2006-10-04 02:16:22 -07001316 rc = -EINVAL;
1317 goto out_free;
1318 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001319 ecryptfs_cipher_code_to_string(crypt_stat->cipher,
1320 (u16)data[(*packet_size)]);
1321 /* A little extra work to differentiate among the AES key
1322 * sizes; see RFC2440 */
1323 switch(data[(*packet_size)++]) {
1324 case RFC2440_CIPHER_AES_192:
1325 crypt_stat->key_size = 24;
1326 break;
1327 default:
1328 crypt_stat->key_size =
1329 (*new_auth_tok)->session_key.encrypted_key_size;
1330 }
1331 ecryptfs_init_crypt_ctx(crypt_stat);
Michael Halcrow237fead2006-10-04 02:16:22 -07001332 if (unlikely(data[(*packet_size)++] != 0x03)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001333 printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001334 rc = -ENOSYS;
1335 goto out_free;
1336 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001337 /* TODO: finish the hash mapping */
Michael Halcrow237fead2006-10-04 02:16:22 -07001338 switch (data[(*packet_size)++]) {
1339 case 0x01: /* See RFC2440 for these numbers and their mappings */
1340 /* Choose MD5 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001341 memcpy((*new_auth_tok)->token.password.salt,
1342 &data[(*packet_size)], ECRYPTFS_SALT_SIZE);
1343 (*packet_size) += ECRYPTFS_SALT_SIZE;
Michael Halcrow237fead2006-10-04 02:16:22 -07001344 /* This conversion was taken straight from RFC2440 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001345 (*new_auth_tok)->token.password.hash_iterations =
1346 ((u32) 16 + (data[(*packet_size)] & 15))
1347 << ((data[(*packet_size)] >> 4) + 6);
1348 (*packet_size)++;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001349 /* Friendly reminder:
1350 * (*new_auth_tok)->session_key.encrypted_key_size =
1351 * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */
Michael Halcrow237fead2006-10-04 02:16:22 -07001352 memcpy((*new_auth_tok)->session_key.encrypted_key,
1353 &data[(*packet_size)],
1354 (*new_auth_tok)->session_key.encrypted_key_size);
1355 (*packet_size) +=
1356 (*new_auth_tok)->session_key.encrypted_key_size;
1357 (*new_auth_tok)->session_key.flags &=
1358 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1359 (*new_auth_tok)->session_key.flags |=
1360 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001361 (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001362 break;
1363 default:
1364 ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: "
1365 "[%d]\n", data[(*packet_size) - 1]);
1366 rc = -ENOSYS;
1367 goto out_free;
1368 }
1369 (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD;
1370 /* TODO: Parametarize; we might actually want userspace to
1371 * decrypt the session key. */
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001372 (*new_auth_tok)->session_key.flags &=
1373 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1374 (*new_auth_tok)->session_key.flags &=
1375 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
Michael Halcrow237fead2006-10-04 02:16:22 -07001376 list_add(&auth_tok_list_item->list, auth_tok_list);
1377 goto out;
1378out_free:
1379 (*new_auth_tok) = NULL;
1380 memset(auth_tok_list_item, 0,
1381 sizeof(struct ecryptfs_auth_tok_list_item));
1382 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1383 auth_tok_list_item);
1384out:
1385 if (rc)
1386 (*packet_size) = 0;
1387 return rc;
1388}
1389
1390/**
1391 * parse_tag_11_packet
1392 * @data: The raw bytes of the packet
1393 * @contents: This function writes the data contents of the literal
1394 * packet into this memory location
1395 * @max_contents_bytes: The maximum number of bytes that this function
1396 * is allowed to write into contents
1397 * @tag_11_contents_size: This function writes the size of the parsed
1398 * contents into this memory location; zero on
1399 * error
1400 * @packet_size: This function writes the size of the parsed packet
1401 * into this memory location; zero on error
1402 * @max_packet_size: maximum number of bytes to parse
1403 *
1404 * Returns zero on success; non-zero on error.
1405 */
1406static int
1407parse_tag_11_packet(unsigned char *data, unsigned char *contents,
1408 size_t max_contents_bytes, size_t *tag_11_contents_size,
1409 size_t *packet_size, size_t max_packet_size)
1410{
Michael Halcrow237fead2006-10-04 02:16:22 -07001411 size_t body_size;
1412 size_t length_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001413 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001414
1415 (*packet_size) = 0;
1416 (*tag_11_contents_size) = 0;
Michael Halcrowf6481042007-10-16 01:27:57 -07001417 /* This format is inspired by OpenPGP; see RFC 2440
1418 * packet tag 11
1419 *
1420 * Tag 11 identifier (1 byte)
1421 * Max Tag 11 packet size (max 3 bytes)
1422 * Binary format specifier (1 byte)
1423 * Filename length (1 byte)
1424 * Filename ("_CONSOLE") (8 bytes)
1425 * Modification date (4 bytes)
1426 * Literal data (arbitrary)
1427 *
1428 * We need at least 16 bytes of data for the packet to even be
1429 * valid.
Michael Halcrow237fead2006-10-04 02:16:22 -07001430 */
Michael Halcrowf6481042007-10-16 01:27:57 -07001431 if (max_packet_size < 16) {
1432 printk(KERN_ERR "Maximum packet size too small\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001433 rc = -EINVAL;
1434 goto out;
1435 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001436 if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001437 printk(KERN_WARNING "Invalid tag 11 packet format\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001438 rc = -EINVAL;
1439 goto out;
1440 }
Michael Halcrowf66e8832008-04-29 00:59:51 -07001441 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1442 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001443 if (rc) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001444 printk(KERN_WARNING "Invalid tag 11 packet format\n");
1445 goto out;
1446 }
1447 if (body_size < 14) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001448 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrowf6481042007-10-16 01:27:57 -07001449 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07001450 goto out;
1451 }
1452 (*packet_size) += length_size;
Michael Halcrowf6481042007-10-16 01:27:57 -07001453 (*tag_11_contents_size) = (body_size - 14);
Michael Halcrow237fead2006-10-04 02:16:22 -07001454 if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001455 printk(KERN_ERR "Packet size exceeds max\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001456 rc = -EINVAL;
1457 goto out;
1458 }
Tyler Hicks6352a292009-07-28 13:57:01 -05001459 if (unlikely((*tag_11_contents_size) > max_contents_bytes)) {
1460 printk(KERN_ERR "Literal data section in tag 11 packet exceeds "
1461 "expected size\n");
1462 rc = -EINVAL;
1463 goto out;
1464 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001465 if (data[(*packet_size)++] != 0x62) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001466 printk(KERN_WARNING "Unrecognizable packet\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001467 rc = -EINVAL;
1468 goto out;
1469 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001470 if (data[(*packet_size)++] != 0x08) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001471 printk(KERN_WARNING "Unrecognizable packet\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001472 rc = -EINVAL;
1473 goto out;
1474 }
Michael Halcrowf6481042007-10-16 01:27:57 -07001475 (*packet_size) += 12; /* Ignore filename and modification date */
Michael Halcrow237fead2006-10-04 02:16:22 -07001476 memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size));
1477 (*packet_size) += (*tag_11_contents_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001478out:
1479 if (rc) {
1480 (*packet_size) = 0;
1481 (*tag_11_contents_size) = 0;
1482 }
1483 return rc;
1484}
1485
1486/**
Michael Halcrowf4aad162007-10-16 01:27:53 -07001487 * ecryptfs_verify_version
1488 * @version: The version number to confirm
1489 *
1490 * Returns zero on good version; non-zero otherwise
1491 */
1492static int ecryptfs_verify_version(u16 version)
1493{
1494 int rc = 0;
1495 unsigned char major;
1496 unsigned char minor;
1497
1498 major = ((version >> 8) & 0xFF);
1499 minor = (version & 0xFF);
1500 if (major != ECRYPTFS_VERSION_MAJOR) {
1501 ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
1502 "Expected [%d]; got [%d]\n",
1503 ECRYPTFS_VERSION_MAJOR, major);
1504 rc = -EINVAL;
1505 goto out;
1506 }
1507 if (minor != ECRYPTFS_VERSION_MINOR) {
1508 ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
1509 "Expected [%d]; got [%d]\n",
1510 ECRYPTFS_VERSION_MINOR, minor);
1511 rc = -EINVAL;
1512 goto out;
1513 }
1514out:
1515 return rc;
1516}
1517
1518int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
1519 struct ecryptfs_auth_tok **auth_tok,
1520 char *sig)
1521{
1522 int rc = 0;
1523
1524 (*auth_tok_key) = request_key(&key_type_user, sig, NULL);
1525 if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
1526 printk(KERN_ERR "Could not find key with description: [%s]\n",
1527 sig);
Eric Sandeen982363c2008-07-23 21:30:04 -07001528 rc = process_request_key_err(PTR_ERR(*auth_tok_key));
Michael Halcrowf4aad162007-10-16 01:27:53 -07001529 goto out;
1530 }
1531 (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key);
1532 if (ecryptfs_verify_version((*auth_tok)->version)) {
1533 printk(KERN_ERR
1534 "Data structure version mismatch. "
1535 "Userspace tools must match eCryptfs "
1536 "kernel module with major version [%d] "
1537 "and minor version [%d]\n",
1538 ECRYPTFS_VERSION_MAJOR,
1539 ECRYPTFS_VERSION_MINOR);
1540 rc = -EINVAL;
1541 goto out;
1542 }
1543 if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
1544 && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
1545 printk(KERN_ERR "Invalid auth_tok structure "
1546 "returned from key query\n");
1547 rc = -EINVAL;
1548 goto out;
1549 }
1550out:
1551 return rc;
1552}
1553
1554/**
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001555 * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok.
1556 * @auth_tok: The passphrase authentication token to use to encrypt the FEK
1557 * @crypt_stat: The cryptographic context
Michael Halcrow237fead2006-10-04 02:16:22 -07001558 *
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001559 * Returns zero on success; non-zero error otherwise
Michael Halcrow237fead2006-10-04 02:16:22 -07001560 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07001561static int
1562decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1563 struct ecryptfs_crypt_stat *crypt_stat)
Michael Halcrow237fead2006-10-04 02:16:22 -07001564{
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001565 struct scatterlist dst_sg[2];
1566 struct scatterlist src_sg[2];
Michael Halcrowdd8e2902007-10-16 01:28:03 -07001567 struct mutex *tfm_mutex;
Michael Halcrow8bba0662006-10-30 22:07:18 -08001568 struct blkcipher_desc desc = {
1569 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
1570 };
1571 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001572
Michael Halcrowf4aad162007-10-16 01:27:53 -07001573 if (unlikely(ecryptfs_verbosity > 0)) {
1574 ecryptfs_printk(
1575 KERN_DEBUG, "Session key encryption key (size [%d]):\n",
1576 auth_tok->token.password.session_key_encryption_key_bytes);
1577 ecryptfs_dump_hex(
1578 auth_tok->token.password.session_key_encryption_key,
1579 auth_tok->token.password.session_key_encryption_key_bytes);
Michael Halcrow237fead2006-10-04 02:16:22 -07001580 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001581 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
1582 crypt_stat->cipher);
1583 if (unlikely(rc)) {
1584 printk(KERN_ERR "Internal error whilst attempting to get "
1585 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1586 crypt_stat->cipher, rc);
1587 goto out;
1588 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07001589 rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
1590 auth_tok->session_key.encrypted_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001591 src_sg, 2);
1592 if (rc < 1 || rc > 2) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001593 printk(KERN_ERR "Internal error whilst attempting to convert "
1594 "auth_tok->session_key.encrypted_key to scatterlist; "
1595 "expected rc = 1; got rc = [%d]. "
1596 "auth_tok->session_key.encrypted_key_size = [%d]\n", rc,
1597 auth_tok->session_key.encrypted_key_size);
1598 goto out;
1599 }
1600 auth_tok->session_key.decrypted_key_size =
1601 auth_tok->session_key.encrypted_key_size;
Michael Halcrow5dda6992007-10-16 01:28:06 -07001602 rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key,
1603 auth_tok->session_key.decrypted_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001604 dst_sg, 2);
1605 if (rc < 1 || rc > 2) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001606 printk(KERN_ERR "Internal error whilst attempting to convert "
1607 "auth_tok->session_key.decrypted_key to scatterlist; "
1608 "expected rc = 1; got rc = [%d]\n", rc);
1609 goto out;
1610 }
1611 mutex_lock(tfm_mutex);
1612 rc = crypto_blkcipher_setkey(
1613 desc.tfm, auth_tok->token.password.session_key_encryption_key,
1614 crypt_stat->key_size);
1615 if (unlikely(rc < 0)) {
1616 mutex_unlock(tfm_mutex);
Michael Halcrowe5d9cbd2006-10-30 22:07:16 -08001617 printk(KERN_ERR "Error setting key for crypto context\n");
1618 rc = -EINVAL;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001619 goto out;
Michael Halcrowe5d9cbd2006-10-30 22:07:16 -08001620 }
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001621 rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg,
Michael Halcrow8bba0662006-10-30 22:07:18 -08001622 auth_tok->session_key.encrypted_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001623 mutex_unlock(tfm_mutex);
1624 if (unlikely(rc)) {
Michael Halcrow8bba0662006-10-30 22:07:18 -08001625 printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001626 goto out;
Michael Halcrow8bba0662006-10-30 22:07:18 -08001627 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001628 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1629 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1630 auth_tok->session_key.decrypted_key_size);
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001631 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001632 if (unlikely(ecryptfs_verbosity > 0)) {
1633 ecryptfs_printk(KERN_DEBUG, "FEK of size [%d]:\n",
1634 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001635 ecryptfs_dump_hex(crypt_stat->key,
1636 crypt_stat->key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001637 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001638out:
1639 return rc;
1640}
1641
1642/**
1643 * ecryptfs_parse_packet_set
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001644 * @crypt_stat: The cryptographic context
1645 * @src: Virtual address of region of memory containing the packets
1646 * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set
Michael Halcrow237fead2006-10-04 02:16:22 -07001647 *
1648 * Get crypt_stat to have the file's session key if the requisite key
1649 * is available to decrypt the session key.
1650 *
1651 * Returns Zero if a valid authentication token was retrieved and
1652 * processed; negative value for file not encrypted or for error
1653 * conditions.
1654 */
1655int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
1656 unsigned char *src,
1657 struct dentry *ecryptfs_dentry)
1658{
1659 size_t i = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001660 size_t found_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07001661 size_t next_packet_is_auth_tok_packet;
Michael Halcrow237fead2006-10-04 02:16:22 -07001662 struct list_head auth_tok_list;
Michael Halcrowdd8e2902007-10-16 01:28:03 -07001663 struct ecryptfs_auth_tok *matching_auth_tok;
1664 struct ecryptfs_auth_tok *candidate_auth_tok;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001665 char *candidate_auth_tok_sig;
Michael Halcrow237fead2006-10-04 02:16:22 -07001666 size_t packet_size;
1667 struct ecryptfs_auth_tok *new_auth_tok;
1668 unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE];
Michael Halcrowf4aad162007-10-16 01:27:53 -07001669 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
Michael Halcrow237fead2006-10-04 02:16:22 -07001670 size_t tag_11_contents_size;
1671 size_t tag_11_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001672 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001673
1674 INIT_LIST_HEAD(&auth_tok_list);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001675 /* Parse the header to find as many packets as we can; these will be
Michael Halcrow237fead2006-10-04 02:16:22 -07001676 * added the our &auth_tok_list */
1677 next_packet_is_auth_tok_packet = 1;
1678 while (next_packet_is_auth_tok_packet) {
1679 size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i);
1680
1681 switch (src[i]) {
1682 case ECRYPTFS_TAG_3_PACKET_TYPE:
1683 rc = parse_tag_3_packet(crypt_stat,
1684 (unsigned char *)&src[i],
1685 &auth_tok_list, &new_auth_tok,
1686 &packet_size, max_packet_size);
1687 if (rc) {
1688 ecryptfs_printk(KERN_ERR, "Error parsing "
1689 "tag 3 packet\n");
1690 rc = -EIO;
1691 goto out_wipe_list;
1692 }
1693 i += packet_size;
1694 rc = parse_tag_11_packet((unsigned char *)&src[i],
1695 sig_tmp_space,
1696 ECRYPTFS_SIG_SIZE,
1697 &tag_11_contents_size,
1698 &tag_11_packet_size,
1699 max_packet_size);
1700 if (rc) {
1701 ecryptfs_printk(KERN_ERR, "No valid "
1702 "(ecryptfs-specific) literal "
1703 "packet containing "
1704 "authentication token "
1705 "signature found after "
1706 "tag 3 packet\n");
1707 rc = -EIO;
1708 goto out_wipe_list;
1709 }
1710 i += tag_11_packet_size;
1711 if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) {
1712 ecryptfs_printk(KERN_ERR, "Expected "
1713 "signature of size [%d]; "
1714 "read size [%d]\n",
1715 ECRYPTFS_SIG_SIZE,
1716 tag_11_contents_size);
1717 rc = -EIO;
1718 goto out_wipe_list;
1719 }
1720 ecryptfs_to_hex(new_auth_tok->token.password.signature,
1721 sig_tmp_space, tag_11_contents_size);
1722 new_auth_tok->token.password.signature[
1723 ECRYPTFS_PASSWORD_SIG_SIZE] = '\0';
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001724 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
Michael Halcrow237fead2006-10-04 02:16:22 -07001725 break;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001726 case ECRYPTFS_TAG_1_PACKET_TYPE:
1727 rc = parse_tag_1_packet(crypt_stat,
1728 (unsigned char *)&src[i],
1729 &auth_tok_list, &new_auth_tok,
1730 &packet_size, max_packet_size);
1731 if (rc) {
1732 ecryptfs_printk(KERN_ERR, "Error parsing "
1733 "tag 1 packet\n");
1734 rc = -EIO;
1735 goto out_wipe_list;
1736 }
1737 i += packet_size;
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001738 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001739 break;
Michael Halcrow237fead2006-10-04 02:16:22 -07001740 case ECRYPTFS_TAG_11_PACKET_TYPE:
1741 ecryptfs_printk(KERN_WARNING, "Invalid packet set "
1742 "(Tag 11 not allowed by itself)\n");
1743 rc = -EIO;
1744 goto out_wipe_list;
1745 break;
1746 default:
1747 ecryptfs_printk(KERN_DEBUG, "No packet at offset "
1748 "[%d] of the file header; hex value of "
1749 "character is [0x%.2x]\n", i, src[i]);
1750 next_packet_is_auth_tok_packet = 0;
1751 }
1752 }
1753 if (list_empty(&auth_tok_list)) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001754 printk(KERN_ERR "The lower file appears to be a non-encrypted "
1755 "eCryptfs file; this is not supported in this version "
1756 "of the eCryptfs kernel module\n");
1757 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07001758 goto out;
1759 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001760 /* auth_tok_list contains the set of authentication tokens
1761 * parsed from the metadata. We need to find a matching
1762 * authentication token that has the secret component(s)
1763 * necessary to decrypt the EFEK in the auth_tok parsed from
1764 * the metadata. There may be several potential matches, but
1765 * just one will be sufficient to decrypt to get the FEK. */
1766find_next_matching_auth_tok:
1767 found_auth_tok = 0;
1768 list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001769 candidate_auth_tok = &auth_tok_list_item->auth_tok;
1770 if (unlikely(ecryptfs_verbosity > 0)) {
1771 ecryptfs_printk(KERN_DEBUG,
1772 "Considering cadidate auth tok:\n");
1773 ecryptfs_dump_auth_tok(candidate_auth_tok);
1774 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07001775 rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig,
1776 candidate_auth_tok);
1777 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001778 printk(KERN_ERR
1779 "Unrecognized candidate auth tok type: [%d]\n",
1780 candidate_auth_tok->token_type);
1781 rc = -EINVAL;
1782 goto out_wipe_list;
1783 }
Michael Halcrow9c79f342009-01-06 14:41:57 -08001784 ecryptfs_find_auth_tok_for_sig(&matching_auth_tok,
1785 crypt_stat->mount_crypt_stat,
Michael Halcrow5dda6992007-10-16 01:28:06 -07001786 candidate_auth_tok_sig);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001787 if (matching_auth_tok) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001788 found_auth_tok = 1;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001789 goto found_matching_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07001790 }
1791 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001792 if (!found_auth_tok) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001793 ecryptfs_printk(KERN_ERR, "Could not find a usable "
1794 "authentication token\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001795 rc = -EIO;
1796 goto out_wipe_list;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001797 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001798found_matching_auth_tok:
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001799 if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
Michael Halcrowdddfa462007-02-12 00:53:44 -08001800 memcpy(&(candidate_auth_tok->token.private_key),
Michael Halcrowf4aad162007-10-16 01:27:53 -07001801 &(matching_auth_tok->token.private_key),
Michael Halcrowdddfa462007-02-12 00:53:44 -08001802 sizeof(struct ecryptfs_private_key));
Michael Halcrowf4aad162007-10-16 01:27:53 -07001803 rc = decrypt_pki_encrypted_session_key(candidate_auth_tok,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001804 crypt_stat);
1805 } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001806 memcpy(&(candidate_auth_tok->token.password),
Michael Halcrowf4aad162007-10-16 01:27:53 -07001807 &(matching_auth_tok->token.password),
Michael Halcrow237fead2006-10-04 02:16:22 -07001808 sizeof(struct ecryptfs_password));
Michael Halcrowf4aad162007-10-16 01:27:53 -07001809 rc = decrypt_passphrase_encrypted_session_key(
1810 candidate_auth_tok, crypt_stat);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001811 }
1812 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001813 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1814
1815 ecryptfs_printk(KERN_WARNING, "Error decrypting the "
1816 "session key for authentication token with sig "
1817 "[%.*s]; rc = [%d]. Removing auth tok "
1818 "candidate from the list and searching for "
1819 "the next match.\n", candidate_auth_tok_sig,
1820 ECRYPTFS_SIG_SIZE_HEX, rc);
1821 list_for_each_entry_safe(auth_tok_list_item,
1822 auth_tok_list_item_tmp,
1823 &auth_tok_list, list) {
1824 if (candidate_auth_tok
1825 == &auth_tok_list_item->auth_tok) {
1826 list_del(&auth_tok_list_item->list);
1827 kmem_cache_free(
1828 ecryptfs_auth_tok_list_item_cache,
1829 auth_tok_list_item);
1830 goto find_next_matching_auth_tok;
1831 }
1832 }
1833 BUG();
Michael Halcrowdddfa462007-02-12 00:53:44 -08001834 }
1835 rc = ecryptfs_compute_root_iv(crypt_stat);
1836 if (rc) {
1837 ecryptfs_printk(KERN_ERR, "Error computing "
1838 "the root IV\n");
1839 goto out_wipe_list;
Michael Halcrow237fead2006-10-04 02:16:22 -07001840 }
1841 rc = ecryptfs_init_crypt_ctx(crypt_stat);
1842 if (rc) {
1843 ecryptfs_printk(KERN_ERR, "Error initializing crypto "
1844 "context for cipher [%s]; rc = [%d]\n",
1845 crypt_stat->cipher, rc);
1846 }
1847out_wipe_list:
1848 wipe_auth_tok_list(&auth_tok_list);
1849out:
1850 return rc;
1851}
Michael Halcrowf4aad162007-10-16 01:27:53 -07001852
Michael Halcrowdddfa462007-02-12 00:53:44 -08001853static int
1854pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
1855 struct ecryptfs_crypt_stat *crypt_stat,
1856 struct ecryptfs_key_record *key_rec)
1857{
1858 struct ecryptfs_msg_ctx *msg_ctx = NULL;
Tyler Hicks624ae522008-10-15 22:02:51 -07001859 char *payload = NULL;
1860 size_t payload_len;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001861 struct ecryptfs_message *msg;
1862 int rc;
1863
1864 rc = write_tag_66_packet(auth_tok->token.private_key.signature,
Michael Halcrow9c79f342009-01-06 14:41:57 -08001865 ecryptfs_code_for_cipher_string(
1866 crypt_stat->cipher,
1867 crypt_stat->key_size),
Tyler Hicks624ae522008-10-15 22:02:51 -07001868 crypt_stat, &payload, &payload_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001869 if (rc) {
1870 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
1871 goto out;
1872 }
Tyler Hicks624ae522008-10-15 22:02:51 -07001873 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001874 if (rc) {
Tyler Hicks624ae522008-10-15 22:02:51 -07001875 ecryptfs_printk(KERN_ERR, "Error sending message to "
1876 "ecryptfsd\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001877 goto out;
1878 }
1879 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1880 if (rc) {
1881 ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet "
1882 "from the user space daemon\n");
1883 rc = -EIO;
1884 goto out;
1885 }
1886 rc = parse_tag_67_packet(key_rec, msg);
1887 if (rc)
1888 ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n");
1889 kfree(msg);
1890out:
Tyler Hicks624ae522008-10-15 22:02:51 -07001891 kfree(payload);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001892 return rc;
1893}
1894/**
1895 * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet
1896 * @dest: Buffer into which to write the packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001897 * @remaining_bytes: Maximum number of bytes that can be writtn
1898 * @auth_tok: The authentication token used for generating the tag 1 packet
1899 * @crypt_stat: The cryptographic context
1900 * @key_rec: The key record struct for the tag 1 packet
Michael Halcrowdddfa462007-02-12 00:53:44 -08001901 * @packet_size: This function will write the number of bytes that end
1902 * up constituting the packet; set to zero on error
1903 *
1904 * Returns zero on success; non-zero on error.
1905 */
1906static int
Michael Halcrowf4aad162007-10-16 01:27:53 -07001907write_tag_1_packet(char *dest, size_t *remaining_bytes,
1908 struct ecryptfs_auth_tok *auth_tok,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001909 struct ecryptfs_crypt_stat *crypt_stat,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001910 struct ecryptfs_key_record *key_rec, size_t *packet_size)
1911{
1912 size_t i;
1913 size_t encrypted_session_key_valid = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001914 size_t packet_size_length;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001915 size_t max_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001916 int rc = 0;
1917
1918 (*packet_size) = 0;
1919 ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature,
1920 ECRYPTFS_SIG_SIZE);
1921 encrypted_session_key_valid = 0;
1922 for (i = 0; i < crypt_stat->key_size; i++)
1923 encrypted_session_key_valid |=
1924 auth_tok->session_key.encrypted_key[i];
1925 if (encrypted_session_key_valid) {
1926 memcpy(key_rec->enc_key,
1927 auth_tok->session_key.encrypted_key,
1928 auth_tok->session_key.encrypted_key_size);
1929 goto encrypted_session_key_set;
1930 }
1931 if (auth_tok->session_key.encrypted_key_size == 0)
1932 auth_tok->session_key.encrypted_key_size =
1933 auth_tok->token.private_key.key_size;
1934 rc = pki_encrypt_session_key(auth_tok, crypt_stat, key_rec);
1935 if (rc) {
Michael Halcrowf66e8832008-04-29 00:59:51 -07001936 printk(KERN_ERR "Failed to encrypt session key via a key "
1937 "module; rc = [%d]\n", rc);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001938 goto out;
1939 }
1940 if (ecryptfs_verbosity > 0) {
1941 ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n");
1942 ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size);
1943 }
1944encrypted_session_key_set:
Michael Halcrowf4aad162007-10-16 01:27:53 -07001945 /* This format is inspired by OpenPGP; see RFC 2440
1946 * packet tag 1 */
1947 max_packet_size = (1 /* Tag 1 identifier */
1948 + 3 /* Max Tag 1 packet size */
1949 + 1 /* Version */
1950 + ECRYPTFS_SIG_SIZE /* Key identifier */
1951 + 1 /* Cipher identifier */
1952 + key_rec->enc_key_size); /* Encrypted key size */
1953 if (max_packet_size > (*remaining_bytes)) {
1954 printk(KERN_ERR "Packet length larger than maximum allowable; "
Andrew Morton81acbcd2007-10-16 01:27:59 -07001955 "need up to [%td] bytes, but there are only [%td] "
Michael Halcrowf4aad162007-10-16 01:27:53 -07001956 "available\n", max_packet_size, (*remaining_bytes));
Michael Halcrowdddfa462007-02-12 00:53:44 -08001957 rc = -EINVAL;
1958 goto out;
1959 }
1960 dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001961 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
1962 (max_packet_size - 4),
1963 &packet_size_length);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001964 if (rc) {
1965 ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet "
1966 "header; cannot generate packet length\n");
1967 goto out;
1968 }
1969 (*packet_size) += packet_size_length;
1970 dest[(*packet_size)++] = 0x03; /* version 3 */
1971 memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE);
1972 (*packet_size) += ECRYPTFS_SIG_SIZE;
1973 dest[(*packet_size)++] = RFC2440_CIPHER_RSA;
1974 memcpy(&dest[(*packet_size)], key_rec->enc_key,
1975 key_rec->enc_key_size);
1976 (*packet_size) += key_rec->enc_key_size;
1977out:
1978 if (rc)
1979 (*packet_size) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001980 else
1981 (*remaining_bytes) -= (*packet_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001982 return rc;
1983}
Michael Halcrow237fead2006-10-04 02:16:22 -07001984
1985/**
1986 * write_tag_11_packet
1987 * @dest: Target into which Tag 11 packet is to be written
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001988 * @remaining_bytes: Maximum packet length
Michael Halcrow237fead2006-10-04 02:16:22 -07001989 * @contents: Byte array of contents to copy in
1990 * @contents_length: Number of bytes in contents
1991 * @packet_length: Length of the Tag 11 packet written; zero on error
1992 *
1993 * Returns zero on success; non-zero on error.
1994 */
1995static int
Andrew Morton81acbcd2007-10-16 01:27:59 -07001996write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents,
Michael Halcrow146a4602007-10-16 01:27:58 -07001997 size_t contents_length, size_t *packet_length)
Michael Halcrow237fead2006-10-04 02:16:22 -07001998{
Michael Halcrow237fead2006-10-04 02:16:22 -07001999 size_t packet_size_length;
Michael Halcrow146a4602007-10-16 01:27:58 -07002000 size_t max_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002001 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002002
2003 (*packet_length) = 0;
Michael Halcrow146a4602007-10-16 01:27:58 -07002004 /* This format is inspired by OpenPGP; see RFC 2440
2005 * packet tag 11 */
2006 max_packet_size = (1 /* Tag 11 identifier */
2007 + 3 /* Max Tag 11 packet size */
2008 + 1 /* Binary format specifier */
2009 + 1 /* Filename length */
2010 + 8 /* Filename ("_CONSOLE") */
2011 + 4 /* Modification date */
2012 + contents_length); /* Literal data */
2013 if (max_packet_size > (*remaining_bytes)) {
2014 printk(KERN_ERR "Packet length larger than maximum allowable; "
Andrew Morton81acbcd2007-10-16 01:27:59 -07002015 "need up to [%td] bytes, but there are only [%td] "
Michael Halcrow146a4602007-10-16 01:27:58 -07002016 "available\n", max_packet_size, (*remaining_bytes));
Michael Halcrow237fead2006-10-04 02:16:22 -07002017 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07002018 goto out;
2019 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002020 dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -07002021 rc = ecryptfs_write_packet_length(&dest[(*packet_length)],
2022 (max_packet_size - 4),
2023 &packet_size_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002024 if (rc) {
Michael Halcrow146a4602007-10-16 01:27:58 -07002025 printk(KERN_ERR "Error generating tag 11 packet header; cannot "
2026 "generate packet length. rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002027 goto out;
2028 }
2029 (*packet_length) += packet_size_length;
Michael Halcrow146a4602007-10-16 01:27:58 -07002030 dest[(*packet_length)++] = 0x62; /* binary data format specifier */
Michael Halcrow237fead2006-10-04 02:16:22 -07002031 dest[(*packet_length)++] = 8;
2032 memcpy(&dest[(*packet_length)], "_CONSOLE", 8);
2033 (*packet_length) += 8;
Michael Halcrow237fead2006-10-04 02:16:22 -07002034 memset(&dest[(*packet_length)], 0x00, 4);
2035 (*packet_length) += 4;
Michael Halcrow237fead2006-10-04 02:16:22 -07002036 memcpy(&dest[(*packet_length)], contents, contents_length);
2037 (*packet_length) += contents_length;
2038 out:
2039 if (rc)
2040 (*packet_length) = 0;
Michael Halcrow146a4602007-10-16 01:27:58 -07002041 else
2042 (*remaining_bytes) -= (*packet_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002043 return rc;
2044}
2045
2046/**
2047 * write_tag_3_packet
2048 * @dest: Buffer into which to write the packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002049 * @remaining_bytes: Maximum number of bytes that can be written
Michael Halcrow237fead2006-10-04 02:16:22 -07002050 * @auth_tok: Authentication token
2051 * @crypt_stat: The cryptographic context
2052 * @key_rec: encrypted key
2053 * @packet_size: This function will write the number of bytes that end
2054 * up constituting the packet; set to zero on error
2055 *
2056 * Returns zero on success; non-zero on error.
2057 */
2058static int
Michael Halcrowf4aad162007-10-16 01:27:53 -07002059write_tag_3_packet(char *dest, size_t *remaining_bytes,
2060 struct ecryptfs_auth_tok *auth_tok,
Michael Halcrow237fead2006-10-04 02:16:22 -07002061 struct ecryptfs_crypt_stat *crypt_stat,
2062 struct ecryptfs_key_record *key_rec, size_t *packet_size)
2063{
Michael Halcrow237fead2006-10-04 02:16:22 -07002064 size_t i;
Michael Halcrow237fead2006-10-04 02:16:22 -07002065 size_t encrypted_session_key_valid = 0;
2066 char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002067 struct scatterlist dst_sg[2];
2068 struct scatterlist src_sg[2];
Michael Halcrow237fead2006-10-04 02:16:22 -07002069 struct mutex *tfm_mutex = NULL;
Trevor Highland19e66a62008-02-06 01:38:36 -08002070 u8 cipher_code;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002071 size_t packet_size_length;
2072 size_t max_packet_size;
2073 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2074 crypt_stat->mount_crypt_stat;
Michael Halcrow8bba0662006-10-30 22:07:18 -08002075 struct blkcipher_desc desc = {
2076 .tfm = NULL,
2077 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
2078 };
2079 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002080
2081 (*packet_size) = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002082 ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
Michael Halcrow237fead2006-10-04 02:16:22 -07002083 ECRYPTFS_SIG_SIZE);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002084 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
2085 crypt_stat->cipher);
2086 if (unlikely(rc)) {
2087 printk(KERN_ERR "Internal error whilst attempting to get "
2088 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
2089 crypt_stat->cipher, rc);
2090 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -07002091 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002092 if (mount_crypt_stat->global_default_cipher_key_size == 0) {
2093 struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm);
2094
2095 printk(KERN_WARNING "No key size specified at mount; "
2096 "defaulting to [%d]\n", alg->max_keysize);
2097 mount_crypt_stat->global_default_cipher_key_size =
2098 alg->max_keysize;
2099 }
2100 if (crypt_stat->key_size == 0)
2101 crypt_stat->key_size =
2102 mount_crypt_stat->global_default_cipher_key_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07002103 if (auth_tok->session_key.encrypted_key_size == 0)
2104 auth_tok->session_key.encrypted_key_size =
2105 crypt_stat->key_size;
2106 if (crypt_stat->key_size == 24
2107 && strcmp("aes", crypt_stat->cipher) == 0) {
2108 memset((crypt_stat->key + 24), 0, 8);
2109 auth_tok->session_key.encrypted_key_size = 32;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002110 } else
2111 auth_tok->session_key.encrypted_key_size = crypt_stat->key_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002112 key_rec->enc_key_size =
Michael Halcrow237fead2006-10-04 02:16:22 -07002113 auth_tok->session_key.encrypted_key_size;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002114 encrypted_session_key_valid = 0;
2115 for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++)
2116 encrypted_session_key_valid |=
2117 auth_tok->session_key.encrypted_key[i];
2118 if (encrypted_session_key_valid) {
2119 ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; "
2120 "using auth_tok->session_key.encrypted_key, "
2121 "where key_rec->enc_key_size = [%d]\n",
2122 key_rec->enc_key_size);
2123 memcpy(key_rec->enc_key,
2124 auth_tok->session_key.encrypted_key,
2125 key_rec->enc_key_size);
2126 goto encrypted_session_key_set;
2127 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08002128 if (auth_tok->token.password.flags &
2129 ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002130 ecryptfs_printk(KERN_DEBUG, "Using previously generated "
2131 "session key encryption key of size [%d]\n",
2132 auth_tok->token.password.
2133 session_key_encryption_key_bytes);
2134 memcpy(session_key_encryption_key,
2135 auth_tok->token.password.session_key_encryption_key,
2136 crypt_stat->key_size);
2137 ecryptfs_printk(KERN_DEBUG,
2138 "Cached session key " "encryption key: \n");
2139 if (ecryptfs_verbosity > 0)
2140 ecryptfs_dump_hex(session_key_encryption_key, 16);
2141 }
2142 if (unlikely(ecryptfs_verbosity > 0)) {
2143 ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n");
2144 ecryptfs_dump_hex(session_key_encryption_key, 16);
2145 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07002146 rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002147 src_sg, 2);
2148 if (rc < 1 || rc > 2) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002149 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
Michael Halcrowf4aad162007-10-16 01:27:53 -07002150 "for crypt_stat session key; expected rc = 1; "
2151 "got rc = [%d]. key_rec->enc_key_size = [%d]\n",
2152 rc, key_rec->enc_key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002153 rc = -ENOMEM;
2154 goto out;
2155 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07002156 rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002157 dst_sg, 2);
2158 if (rc < 1 || rc > 2) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002159 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
Michael Halcrowf4aad162007-10-16 01:27:53 -07002160 "for crypt_stat encrypted session key; "
2161 "expected rc = 1; got rc = [%d]. "
2162 "key_rec->enc_key_size = [%d]\n", rc,
2163 key_rec->enc_key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002164 rc = -ENOMEM;
2165 goto out;
2166 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002167 mutex_lock(tfm_mutex);
Michael Halcrow8bba0662006-10-30 22:07:18 -08002168 rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key,
2169 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002170 if (rc < 0) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002171 mutex_unlock(tfm_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -07002172 ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
Michael Halcrow8bba0662006-10-30 22:07:18 -08002173 "context; rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002174 goto out;
2175 }
2176 rc = 0;
2177 ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n",
2178 crypt_stat->key_size);
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002179 rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg,
Michael Halcrow8bba0662006-10-30 22:07:18 -08002180 (*key_rec).enc_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002181 mutex_unlock(tfm_mutex);
Michael Halcrow8bba0662006-10-30 22:07:18 -08002182 if (rc) {
2183 printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc);
2184 goto out;
2185 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002186 ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
Michael Halcrowf4aad162007-10-16 01:27:53 -07002187 if (ecryptfs_verbosity > 0) {
2188 ecryptfs_printk(KERN_DEBUG, "EFEK of size [%d]:\n",
2189 key_rec->enc_key_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002190 ecryptfs_dump_hex(key_rec->enc_key,
2191 key_rec->enc_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002192 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002193encrypted_session_key_set:
Michael Halcrow237fead2006-10-04 02:16:22 -07002194 /* This format is inspired by OpenPGP; see RFC 2440
2195 * packet tag 3 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002196 max_packet_size = (1 /* Tag 3 identifier */
2197 + 3 /* Max Tag 3 packet size */
2198 + 1 /* Version */
2199 + 1 /* Cipher code */
2200 + 1 /* S2K specifier */
2201 + 1 /* Hash identifier */
2202 + ECRYPTFS_SALT_SIZE /* Salt */
2203 + 1 /* Hash iterations */
2204 + key_rec->enc_key_size); /* Encrypted key size */
2205 if (max_packet_size > (*remaining_bytes)) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07002206 printk(KERN_ERR "Packet too large; need up to [%td] bytes, but "
2207 "there are only [%td] available\n", max_packet_size,
Michael Halcrowf4aad162007-10-16 01:27:53 -07002208 (*remaining_bytes));
2209 rc = -EINVAL;
2210 goto out;
2211 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002212 dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002213 /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3)
2214 * to get the number of octets in the actual Tag 3 packet */
Michael Halcrowf66e8832008-04-29 00:59:51 -07002215 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
2216 (max_packet_size - 4),
2217 &packet_size_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002218 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002219 printk(KERN_ERR "Error generating tag 3 packet header; cannot "
2220 "generate packet length. rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002221 goto out;
2222 }
2223 (*packet_size) += packet_size_length;
2224 dest[(*packet_size)++] = 0x04; /* version 4 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002225 /* TODO: Break from RFC2440 so that arbitrary ciphers can be
2226 * specified with strings */
Michael Halcrow9c79f342009-01-06 14:41:57 -08002227 cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher,
2228 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002229 if (cipher_code == 0) {
2230 ecryptfs_printk(KERN_WARNING, "Unable to generate code for "
2231 "cipher [%s]\n", crypt_stat->cipher);
2232 rc = -EINVAL;
2233 goto out;
2234 }
2235 dest[(*packet_size)++] = cipher_code;
2236 dest[(*packet_size)++] = 0x03; /* S2K */
2237 dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */
2238 memcpy(&dest[(*packet_size)], auth_tok->token.password.salt,
2239 ECRYPTFS_SALT_SIZE);
2240 (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */
2241 dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */
Michael Halcrowdddfa462007-02-12 00:53:44 -08002242 memcpy(&dest[(*packet_size)], key_rec->enc_key,
2243 key_rec->enc_key_size);
2244 (*packet_size) += key_rec->enc_key_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07002245out:
Michael Halcrow237fead2006-10-04 02:16:22 -07002246 if (rc)
2247 (*packet_size) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002248 else
2249 (*remaining_bytes) -= (*packet_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002250 return rc;
2251}
2252
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002253struct kmem_cache *ecryptfs_key_record_cache;
2254
Michael Halcrow237fead2006-10-04 02:16:22 -07002255/**
2256 * ecryptfs_generate_key_packet_set
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002257 * @dest_base: Virtual address from which to write the key record set
Michael Halcrow237fead2006-10-04 02:16:22 -07002258 * @crypt_stat: The cryptographic context from which the
2259 * authentication tokens will be retrieved
2260 * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat
2261 * for the global parameters
2262 * @len: The amount written
2263 * @max: The maximum amount of data allowed to be written
2264 *
2265 * Generates a key packet set and writes it to the virtual address
2266 * passed in.
2267 *
2268 * Returns zero on success; non-zero on error.
2269 */
2270int
2271ecryptfs_generate_key_packet_set(char *dest_base,
2272 struct ecryptfs_crypt_stat *crypt_stat,
2273 struct dentry *ecryptfs_dentry, size_t *len,
2274 size_t max)
2275{
Michael Halcrow237fead2006-10-04 02:16:22 -07002276 struct ecryptfs_auth_tok *auth_tok;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002277 struct ecryptfs_global_auth_tok *global_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07002278 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2279 &ecryptfs_superblock_to_private(
2280 ecryptfs_dentry->d_sb)->mount_crypt_stat;
2281 size_t written;
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002282 struct ecryptfs_key_record *key_rec;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002283 struct ecryptfs_key_sig *key_sig;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002284 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002285
2286 (*len) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002287 mutex_lock(&crypt_stat->keysig_list_mutex);
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002288 key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL);
2289 if (!key_rec) {
2290 rc = -ENOMEM;
2291 goto out;
2292 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002293 list_for_each_entry(key_sig, &crypt_stat->keysig_list,
2294 crypt_stat_list) {
2295 memset(key_rec, 0, sizeof(*key_rec));
2296 rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
2297 mount_crypt_stat,
2298 key_sig->keysig);
2299 if (rc) {
2300 printk(KERN_ERR "Error attempting to get the global "
2301 "auth_tok; rc = [%d]\n", rc);
2302 goto out_free;
2303 }
2304 if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) {
2305 printk(KERN_WARNING
2306 "Skipping invalid auth tok with sig = [%s]\n",
2307 global_auth_tok->sig);
2308 continue;
2309 }
2310 auth_tok = global_auth_tok->global_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07002311 if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
2312 rc = write_tag_3_packet((dest_base + (*len)),
Michael Halcrowf4aad162007-10-16 01:27:53 -07002313 &max, auth_tok,
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002314 crypt_stat, key_rec,
Michael Halcrow237fead2006-10-04 02:16:22 -07002315 &written);
2316 if (rc) {
2317 ecryptfs_printk(KERN_WARNING, "Error "
2318 "writing tag 3 packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002319 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002320 }
2321 (*len) += written;
2322 /* Write auth tok signature packet */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002323 rc = write_tag_11_packet((dest_base + (*len)), &max,
2324 key_rec->sig,
2325 ECRYPTFS_SIG_SIZE, &written);
Michael Halcrow237fead2006-10-04 02:16:22 -07002326 if (rc) {
2327 ecryptfs_printk(KERN_ERR, "Error writing "
2328 "auth tok signature packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002329 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002330 }
2331 (*len) += written;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002332 } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
2333 rc = write_tag_1_packet(dest_base + (*len),
Michael Halcrowf4aad162007-10-16 01:27:53 -07002334 &max, auth_tok,
2335 crypt_stat, key_rec, &written);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002336 if (rc) {
2337 ecryptfs_printk(KERN_WARNING, "Error "
2338 "writing tag 1 packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002339 goto out_free;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002340 }
2341 (*len) += written;
Michael Halcrow237fead2006-10-04 02:16:22 -07002342 } else {
2343 ecryptfs_printk(KERN_WARNING, "Unsupported "
2344 "authentication token type\n");
2345 rc = -EINVAL;
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002346 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002347 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002348 }
2349 if (likely(max > 0)) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002350 dest_base[(*len)] = 0x00;
2351 } else {
2352 ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n");
2353 rc = -EIO;
2354 }
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002355out_free:
2356 kmem_cache_free(ecryptfs_key_record_cache, key_rec);
Michael Halcrow237fead2006-10-04 02:16:22 -07002357out:
2358 if (rc)
2359 (*len) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002360 mutex_unlock(&crypt_stat->keysig_list_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -07002361 return rc;
2362}
Michael Halcrowf4aad162007-10-16 01:27:53 -07002363
2364struct kmem_cache *ecryptfs_key_sig_cache;
2365
2366int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig)
2367{
2368 struct ecryptfs_key_sig *new_key_sig;
2369 int rc = 0;
2370
2371 new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL);
2372 if (!new_key_sig) {
2373 rc = -ENOMEM;
2374 printk(KERN_ERR
2375 "Error allocating from ecryptfs_key_sig_cache\n");
2376 goto out;
2377 }
2378 memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
2379 mutex_lock(&crypt_stat->keysig_list_mutex);
2380 list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
2381 mutex_unlock(&crypt_stat->keysig_list_mutex);
2382out:
2383 return rc;
2384}
2385
2386struct kmem_cache *ecryptfs_global_auth_tok_cache;
2387
2388int
2389ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
Tyler Hicks84814d62009-03-13 13:51:59 -07002390 char *sig, u32 global_auth_tok_flags)
Michael Halcrowf4aad162007-10-16 01:27:53 -07002391{
2392 struct ecryptfs_global_auth_tok *new_auth_tok;
2393 int rc = 0;
2394
Eric Sandeen459e2162007-12-17 16:19:52 -08002395 new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache,
Michael Halcrowf4aad162007-10-16 01:27:53 -07002396 GFP_KERNEL);
2397 if (!new_auth_tok) {
2398 rc = -ENOMEM;
2399 printk(KERN_ERR "Error allocating from "
2400 "ecryptfs_global_auth_tok_cache\n");
2401 goto out;
2402 }
2403 memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX);
Tyler Hicks84814d62009-03-13 13:51:59 -07002404 new_auth_tok->flags = global_auth_tok_flags;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002405 new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
2406 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
2407 list_add(&new_auth_tok->mount_crypt_stat_list,
2408 &mount_crypt_stat->global_auth_tok_list);
2409 mount_crypt_stat->num_global_auth_toks++;
2410 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
2411out:
2412 return rc;
2413}
2414