blob: a0a7847567e902284d828d53a4731cd5d6326078 [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) {
Tyler Hicks38919592009-08-26 01:54:56 -0500419 rc = key_validate(walker->global_auth_tok_key);
420 if (!rc)
421 (*global_auth_tok) = walker;
Michael Halcrow9c79f342009-01-06 14:41:57 -0800422 goto out;
423 }
424 }
425 rc = -EINVAL;
426out:
427 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
428 return rc;
429}
430
431/**
432 * ecryptfs_find_auth_tok_for_sig
433 * @auth_tok: Set to the matching auth_tok; NULL if not found
434 * @crypt_stat: inode crypt_stat crypto context
435 * @sig: Sig of auth_tok to find
436 *
437 * For now, this function simply looks at the registered auth_tok's
438 * linked off the mount_crypt_stat, so all the auth_toks that can be
439 * used must be registered at mount time. This function could
440 * potentially try a lot harder to find auth_tok's (e.g., by calling
441 * out to ecryptfsd to dynamically retrieve an auth_tok object) so
442 * that static registration of auth_tok's will no longer be necessary.
443 *
444 * Returns zero on no error; non-zero on error
445 */
446static int
447ecryptfs_find_auth_tok_for_sig(
448 struct ecryptfs_auth_tok **auth_tok,
449 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
450 char *sig)
451{
452 struct ecryptfs_global_auth_tok *global_auth_tok;
453 int rc = 0;
454
455 (*auth_tok) = NULL;
456 if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
457 mount_crypt_stat, sig)) {
458 struct key *auth_tok_key;
459
460 rc = ecryptfs_keyring_auth_tok_for_sig(&auth_tok_key, auth_tok,
461 sig);
462 } else
463 (*auth_tok) = global_auth_tok->global_auth_tok;
464 return rc;
465}
466
467/**
468 * write_tag_70_packet can gobble a lot of stack space. We stuff most
469 * of the function's parameters in a kmalloc'd struct to help reduce
470 * eCryptfs' overall stack usage.
471 */
472struct ecryptfs_write_tag_70_packet_silly_stack {
473 u8 cipher_code;
474 size_t max_packet_size;
475 size_t packet_size_len;
476 size_t block_aligned_filename_size;
477 size_t block_size;
478 size_t i;
479 size_t j;
480 size_t num_rand_bytes;
481 struct mutex *tfm_mutex;
482 char *block_aligned_filename;
483 struct ecryptfs_auth_tok *auth_tok;
484 struct scatterlist src_sg;
485 struct scatterlist dst_sg;
486 struct blkcipher_desc desc;
487 char iv[ECRYPTFS_MAX_IV_BYTES];
488 char hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
489 char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
490 struct hash_desc hash_desc;
491 struct scatterlist hash_sg;
492};
493
494/**
495 * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK
496 * @filename: NULL-terminated filename string
497 *
498 * This is the simplest mechanism for achieving filename encryption in
499 * eCryptfs. It encrypts the given filename with the mount-wide
500 * filename encryption key (FNEK) and stores it in a packet to @dest,
501 * which the callee will encode and write directly into the dentry
502 * name.
503 */
504int
505ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
506 size_t *packet_size,
507 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
508 char *filename, size_t filename_size)
509{
510 struct ecryptfs_write_tag_70_packet_silly_stack *s;
511 int rc = 0;
512
513 s = kmalloc(sizeof(*s), GFP_KERNEL);
514 if (!s) {
515 printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
Michael Halcrowdf261c52009-01-06 14:42:02 -0800516 "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
Michael Halcrow9c79f342009-01-06 14:41:57 -0800517 goto out;
518 }
519 s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
520 (*packet_size) = 0;
521 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(
522 &s->desc.tfm,
523 &s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name);
524 if (unlikely(rc)) {
525 printk(KERN_ERR "Internal error whilst attempting to get "
526 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
527 mount_crypt_stat->global_default_fn_cipher_name, rc);
528 goto out;
529 }
530 mutex_lock(s->tfm_mutex);
531 s->block_size = crypto_blkcipher_blocksize(s->desc.tfm);
532 /* Plus one for the \0 separator between the random prefix
533 * and the plaintext filename */
534 s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1);
535 s->block_aligned_filename_size = (s->num_rand_bytes + filename_size);
536 if ((s->block_aligned_filename_size % s->block_size) != 0) {
537 s->num_rand_bytes += (s->block_size
538 - (s->block_aligned_filename_size
539 % s->block_size));
540 s->block_aligned_filename_size = (s->num_rand_bytes
541 + filename_size);
542 }
543 /* Octet 0: Tag 70 identifier
544 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
545 * and block-aligned encrypted filename size)
546 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
547 * Octet N2-N3: Cipher identifier (1 octet)
548 * Octets N3-N4: Block-aligned encrypted filename
549 * - Consists of a minimum number of random characters, a \0
550 * separator, and then the filename */
551 s->max_packet_size = (1 /* Tag 70 identifier */
552 + 3 /* Max Tag 70 packet size */
553 + ECRYPTFS_SIG_SIZE /* FNEK sig */
554 + 1 /* Cipher identifier */
555 + s->block_aligned_filename_size);
556 if (dest == NULL) {
557 (*packet_size) = s->max_packet_size;
558 goto out_unlock;
559 }
560 if (s->max_packet_size > (*remaining_bytes)) {
Michael Halcrowa8f12862009-01-06 14:42:03 -0800561 printk(KERN_WARNING "%s: Require [%zd] bytes to write; only "
562 "[%zd] available\n", __func__, s->max_packet_size,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800563 (*remaining_bytes));
564 rc = -EINVAL;
565 goto out_unlock;
566 }
567 s->block_aligned_filename = kzalloc(s->block_aligned_filename_size,
568 GFP_KERNEL);
569 if (!s->block_aligned_filename) {
570 printk(KERN_ERR "%s: Out of kernel memory whilst attempting to "
Michael Halcrowdf261c52009-01-06 14:42:02 -0800571 "kzalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800572 s->block_aligned_filename_size);
573 rc = -ENOMEM;
574 goto out_unlock;
575 }
576 s->i = 0;
577 dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE;
578 rc = ecryptfs_write_packet_length(&dest[s->i],
579 (ECRYPTFS_SIG_SIZE
580 + 1 /* Cipher code */
581 + s->block_aligned_filename_size),
582 &s->packet_size_len);
583 if (rc) {
584 printk(KERN_ERR "%s: Error generating tag 70 packet "
585 "header; cannot generate packet length; rc = [%d]\n",
586 __func__, rc);
587 goto out_free_unlock;
588 }
589 s->i += s->packet_size_len;
590 ecryptfs_from_hex(&dest[s->i],
591 mount_crypt_stat->global_default_fnek_sig,
592 ECRYPTFS_SIG_SIZE);
593 s->i += ECRYPTFS_SIG_SIZE;
594 s->cipher_code = ecryptfs_code_for_cipher_string(
595 mount_crypt_stat->global_default_fn_cipher_name,
596 mount_crypt_stat->global_default_fn_cipher_key_bytes);
597 if (s->cipher_code == 0) {
598 printk(KERN_WARNING "%s: Unable to generate code for "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800599 "cipher [%s] with key bytes [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800600 mount_crypt_stat->global_default_fn_cipher_name,
601 mount_crypt_stat->global_default_fn_cipher_key_bytes);
602 rc = -EINVAL;
603 goto out_free_unlock;
604 }
605 dest[s->i++] = s->cipher_code;
606 rc = ecryptfs_find_auth_tok_for_sig(
607 &s->auth_tok, mount_crypt_stat,
608 mount_crypt_stat->global_default_fnek_sig);
609 if (rc) {
610 printk(KERN_ERR "%s: Error attempting to find auth tok for "
611 "fnek sig [%s]; rc = [%d]\n", __func__,
612 mount_crypt_stat->global_default_fnek_sig, rc);
613 goto out_free_unlock;
614 }
615 /* TODO: Support other key modules than passphrase for
616 * filename encryption */
Tyler Hicksdf6ad332009-08-21 04:27:46 -0500617 if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {
618 rc = -EOPNOTSUPP;
619 printk(KERN_INFO "%s: Filename encryption only supports "
620 "password tokens\n", __func__);
621 goto out_free_unlock;
622 }
Michael Halcrow9c79f342009-01-06 14:41:57 -0800623 sg_init_one(
624 &s->hash_sg,
625 (u8 *)s->auth_tok->token.password.session_key_encryption_key,
626 s->auth_tok->token.password.session_key_encryption_key_bytes);
627 s->hash_desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
628 s->hash_desc.tfm = crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST, 0,
629 CRYPTO_ALG_ASYNC);
630 if (IS_ERR(s->hash_desc.tfm)) {
631 rc = PTR_ERR(s->hash_desc.tfm);
632 printk(KERN_ERR "%s: Error attempting to "
633 "allocate hash crypto context; rc = [%d]\n",
634 __func__, rc);
635 goto out_free_unlock;
636 }
637 rc = crypto_hash_init(&s->hash_desc);
638 if (rc) {
639 printk(KERN_ERR
640 "%s: Error initializing crypto hash; rc = [%d]\n",
641 __func__, rc);
642 goto out_release_free_unlock;
643 }
644 rc = crypto_hash_update(
645 &s->hash_desc, &s->hash_sg,
646 s->auth_tok->token.password.session_key_encryption_key_bytes);
647 if (rc) {
648 printk(KERN_ERR
649 "%s: Error updating crypto hash; rc = [%d]\n",
650 __func__, rc);
651 goto out_release_free_unlock;
652 }
653 rc = crypto_hash_final(&s->hash_desc, s->hash);
654 if (rc) {
655 printk(KERN_ERR
656 "%s: Error finalizing crypto hash; rc = [%d]\n",
657 __func__, rc);
658 goto out_release_free_unlock;
659 }
660 for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) {
661 s->block_aligned_filename[s->j] =
662 s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)];
663 if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)
664 == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) {
665 sg_init_one(&s->hash_sg, (u8 *)s->hash,
666 ECRYPTFS_TAG_70_DIGEST_SIZE);
667 rc = crypto_hash_init(&s->hash_desc);
668 if (rc) {
669 printk(KERN_ERR
670 "%s: Error initializing crypto hash; "
671 "rc = [%d]\n", __func__, rc);
672 goto out_release_free_unlock;
673 }
674 rc = crypto_hash_update(&s->hash_desc, &s->hash_sg,
675 ECRYPTFS_TAG_70_DIGEST_SIZE);
676 if (rc) {
677 printk(KERN_ERR
678 "%s: Error updating crypto hash; "
679 "rc = [%d]\n", __func__, rc);
680 goto out_release_free_unlock;
681 }
682 rc = crypto_hash_final(&s->hash_desc, s->tmp_hash);
683 if (rc) {
684 printk(KERN_ERR
685 "%s: Error finalizing crypto hash; "
686 "rc = [%d]\n", __func__, rc);
687 goto out_release_free_unlock;
688 }
689 memcpy(s->hash, s->tmp_hash,
690 ECRYPTFS_TAG_70_DIGEST_SIZE);
691 }
692 if (s->block_aligned_filename[s->j] == '\0')
693 s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL;
694 }
695 memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename,
696 filename_size);
697 rc = virt_to_scatterlist(s->block_aligned_filename,
698 s->block_aligned_filename_size, &s->src_sg, 1);
699 if (rc != 1) {
700 printk(KERN_ERR "%s: Internal error whilst attempting to "
701 "convert filename memory to scatterlist; "
702 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800703 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800704 s->block_aligned_filename_size);
705 goto out_release_free_unlock;
706 }
707 rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size,
708 &s->dst_sg, 1);
709 if (rc != 1) {
710 printk(KERN_ERR "%s: Internal error whilst attempting to "
711 "convert encrypted filename memory to scatterlist; "
712 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800713 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800714 s->block_aligned_filename_size);
715 goto out_release_free_unlock;
716 }
717 /* The characters in the first block effectively do the job
718 * of the IV here, so we just use 0's for the IV. Note the
719 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
720 * >= ECRYPTFS_MAX_IV_BYTES. */
721 memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
722 s->desc.info = s->iv;
723 rc = crypto_blkcipher_setkey(
724 s->desc.tfm,
725 s->auth_tok->token.password.session_key_encryption_key,
726 mount_crypt_stat->global_default_fn_cipher_key_bytes);
727 if (rc < 0) {
728 printk(KERN_ERR "%s: Error setting key for crypto context; "
729 "rc = [%d]. s->auth_tok->token.password.session_key_"
730 "encryption_key = [0x%p]; mount_crypt_stat->"
Michael Halcrowdf261c52009-01-06 14:42:02 -0800731 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800732 rc,
733 s->auth_tok->token.password.session_key_encryption_key,
734 mount_crypt_stat->global_default_fn_cipher_key_bytes);
735 goto out_release_free_unlock;
736 }
737 rc = crypto_blkcipher_encrypt_iv(&s->desc, &s->dst_sg, &s->src_sg,
738 s->block_aligned_filename_size);
739 if (rc) {
740 printk(KERN_ERR "%s: Error attempting to encrypt filename; "
741 "rc = [%d]\n", __func__, rc);
742 goto out_release_free_unlock;
743 }
744 s->i += s->block_aligned_filename_size;
745 (*packet_size) = s->i;
746 (*remaining_bytes) -= (*packet_size);
747out_release_free_unlock:
748 crypto_free_hash(s->hash_desc.tfm);
749out_free_unlock:
Johannes Weiner00fcf2c2009-03-31 15:24:42 -0700750 kzfree(s->block_aligned_filename);
Michael Halcrow9c79f342009-01-06 14:41:57 -0800751out_unlock:
752 mutex_unlock(s->tfm_mutex);
753out:
754 kfree(s);
755 return rc;
756}
757
758struct ecryptfs_parse_tag_70_packet_silly_stack {
759 u8 cipher_code;
760 size_t max_packet_size;
761 size_t packet_size_len;
762 size_t parsed_tag_70_packet_size;
763 size_t block_aligned_filename_size;
764 size_t block_size;
765 size_t i;
766 struct mutex *tfm_mutex;
767 char *decrypted_filename;
768 struct ecryptfs_auth_tok *auth_tok;
769 struct scatterlist src_sg;
770 struct scatterlist dst_sg;
771 struct blkcipher_desc desc;
772 char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1];
773 char iv[ECRYPTFS_MAX_IV_BYTES];
774 char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE];
775};
776
777/**
778 * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet
779 * @filename: This function kmalloc's the memory for the filename
Michael Halcrow7d8bc2b2009-01-06 14:42:04 -0800780 * @filename_size: This function sets this to the amount of memory
781 * kmalloc'd for the filename
782 * @packet_size: This function sets this to the the number of octets
783 * in the packet parsed
784 * @mount_crypt_stat: The mount-wide cryptographic context
785 * @data: The memory location containing the start of the tag 70
786 * packet
787 * @max_packet_size: The maximum legal size of the packet to be parsed
788 * from @data
789 *
790 * Returns zero on success; non-zero otherwise
Michael Halcrow9c79f342009-01-06 14:41:57 -0800791 */
792int
793ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
794 size_t *packet_size,
795 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
796 char *data, size_t max_packet_size)
797{
798 struct ecryptfs_parse_tag_70_packet_silly_stack *s;
799 int rc = 0;
800
801 (*packet_size) = 0;
802 (*filename_size) = 0;
803 (*filename) = NULL;
804 s = kmalloc(sizeof(*s), GFP_KERNEL);
805 if (!s) {
806 printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800807 "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
Michael Halcrow9c79f342009-01-06 14:41:57 -0800808 goto out;
809 }
810 s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
811 if (max_packet_size < (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)) {
Michael Halcrowdf261c52009-01-06 14:42:02 -0800812 printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be "
Michael Halcrow9c79f342009-01-06 14:41:57 -0800813 "at least [%d]\n", __func__, max_packet_size,
814 (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1));
815 rc = -EINVAL;
816 goto out;
817 }
818 /* Octet 0: Tag 70 identifier
819 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
820 * and block-aligned encrypted filename size)
821 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
822 * Octet N2-N3: Cipher identifier (1 octet)
823 * Octets N3-N4: Block-aligned encrypted filename
824 * - Consists of a minimum number of random numbers, a \0
825 * separator, and then the filename */
826 if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) {
827 printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be "
828 "tag [0x%.2x]\n", __func__,
829 data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE);
830 rc = -EINVAL;
831 goto out;
832 }
833 rc = ecryptfs_parse_packet_length(&data[(*packet_size)],
834 &s->parsed_tag_70_packet_size,
835 &s->packet_size_len);
836 if (rc) {
837 printk(KERN_WARNING "%s: Error parsing packet length; "
838 "rc = [%d]\n", __func__, rc);
839 goto out;
840 }
841 s->block_aligned_filename_size = (s->parsed_tag_70_packet_size
842 - ECRYPTFS_SIG_SIZE - 1);
843 if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size)
844 > max_packet_size) {
Michael Halcrowa8f12862009-01-06 14:42:03 -0800845 printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet "
846 "size is [%zd]\n", __func__, max_packet_size,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800847 (1 + s->packet_size_len + 1
848 + s->block_aligned_filename_size));
849 rc = -EINVAL;
850 goto out;
851 }
852 (*packet_size) += s->packet_size_len;
853 ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)],
854 ECRYPTFS_SIG_SIZE);
855 s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0';
856 (*packet_size) += ECRYPTFS_SIG_SIZE;
857 s->cipher_code = data[(*packet_size)++];
858 rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code);
859 if (rc) {
860 printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n",
861 __func__, s->cipher_code);
862 goto out;
863 }
864 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm,
865 &s->tfm_mutex,
866 s->cipher_string);
867 if (unlikely(rc)) {
868 printk(KERN_ERR "Internal error whilst attempting to get "
869 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
870 s->cipher_string, rc);
871 goto out;
872 }
873 mutex_lock(s->tfm_mutex);
874 rc = virt_to_scatterlist(&data[(*packet_size)],
875 s->block_aligned_filename_size, &s->src_sg, 1);
876 if (rc != 1) {
877 printk(KERN_ERR "%s: Internal error whilst attempting to "
878 "convert encrypted filename memory to scatterlist; "
879 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800880 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800881 s->block_aligned_filename_size);
882 goto out_unlock;
883 }
884 (*packet_size) += s->block_aligned_filename_size;
885 s->decrypted_filename = kmalloc(s->block_aligned_filename_size,
886 GFP_KERNEL);
887 if (!s->decrypted_filename) {
888 printk(KERN_ERR "%s: Out of memory whilst attempting to "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800889 "kmalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800890 s->block_aligned_filename_size);
891 rc = -ENOMEM;
892 goto out_unlock;
893 }
894 rc = virt_to_scatterlist(s->decrypted_filename,
895 s->block_aligned_filename_size, &s->dst_sg, 1);
896 if (rc != 1) {
897 printk(KERN_ERR "%s: Internal error whilst attempting to "
898 "convert decrypted filename memory to scatterlist; "
899 "expected rc = 1; got rc = [%d]. "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800900 "block_aligned_filename_size = [%zd]\n", __func__, rc,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800901 s->block_aligned_filename_size);
902 goto out_free_unlock;
903 }
904 /* The characters in the first block effectively do the job of
905 * the IV here, so we just use 0's for the IV. Note the
906 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
907 * >= ECRYPTFS_MAX_IV_BYTES. */
908 memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
909 s->desc.info = s->iv;
910 rc = ecryptfs_find_auth_tok_for_sig(&s->auth_tok, mount_crypt_stat,
911 s->fnek_sig_hex);
912 if (rc) {
913 printk(KERN_ERR "%s: Error attempting to find auth tok for "
914 "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex,
915 rc);
916 goto out_free_unlock;
917 }
918 /* TODO: Support other key modules than passphrase for
919 * filename encryption */
Tyler Hicksdf6ad332009-08-21 04:27:46 -0500920 if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) {
921 rc = -EOPNOTSUPP;
922 printk(KERN_INFO "%s: Filename encryption only supports "
923 "password tokens\n", __func__);
924 goto out_free_unlock;
925 }
Michael Halcrow9c79f342009-01-06 14:41:57 -0800926 rc = crypto_blkcipher_setkey(
927 s->desc.tfm,
928 s->auth_tok->token.password.session_key_encryption_key,
929 mount_crypt_stat->global_default_fn_cipher_key_bytes);
930 if (rc < 0) {
931 printk(KERN_ERR "%s: Error setting key for crypto context; "
932 "rc = [%d]. s->auth_tok->token.password.session_key_"
933 "encryption_key = [0x%p]; mount_crypt_stat->"
Michael Halcrowdf261c52009-01-06 14:42:02 -0800934 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800935 rc,
936 s->auth_tok->token.password.session_key_encryption_key,
937 mount_crypt_stat->global_default_fn_cipher_key_bytes);
938 goto out_free_unlock;
939 }
940 rc = crypto_blkcipher_decrypt_iv(&s->desc, &s->dst_sg, &s->src_sg,
941 s->block_aligned_filename_size);
942 if (rc) {
943 printk(KERN_ERR "%s: Error attempting to decrypt filename; "
944 "rc = [%d]\n", __func__, rc);
945 goto out_free_unlock;
946 }
947 s->i = 0;
948 while (s->decrypted_filename[s->i] != '\0'
949 && s->i < s->block_aligned_filename_size)
950 s->i++;
951 if (s->i == s->block_aligned_filename_size) {
952 printk(KERN_WARNING "%s: Invalid tag 70 packet; could not "
953 "find valid separator between random characters and "
954 "the filename\n", __func__);
955 rc = -EINVAL;
956 goto out_free_unlock;
957 }
958 s->i++;
959 (*filename_size) = (s->block_aligned_filename_size - s->i);
960 if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) {
Michael Halcrowdf261c52009-01-06 14:42:02 -0800961 printk(KERN_WARNING "%s: Filename size is [%zd], which is "
Michael Halcrow9c79f342009-01-06 14:41:57 -0800962 "invalid\n", __func__, (*filename_size));
963 rc = -EINVAL;
964 goto out_free_unlock;
965 }
966 (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL);
967 if (!(*filename)) {
968 printk(KERN_ERR "%s: Out of memory whilst attempting to "
Michael Halcrowa8f12862009-01-06 14:42:03 -0800969 "kmalloc [%zd] bytes\n", __func__,
Michael Halcrow9c79f342009-01-06 14:41:57 -0800970 ((*filename_size) + 1));
971 rc = -ENOMEM;
972 goto out_free_unlock;
973 }
974 memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size));
975 (*filename)[(*filename_size)] = '\0';
976out_free_unlock:
977 kfree(s->decrypted_filename);
978out_unlock:
979 mutex_unlock(s->tfm_mutex);
980out:
981 if (rc) {
982 (*packet_size) = 0;
983 (*filename_size) = 0;
984 (*filename) = NULL;
985 }
986 kfree(s);
987 return rc;
988}
989
990static int
Michael Halcrowcd9d67d2007-10-16 01:28:04 -0700991ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok)
992{
993 int rc = 0;
994
995 (*sig) = NULL;
996 switch (auth_tok->token_type) {
997 case ECRYPTFS_PASSWORD:
998 (*sig) = auth_tok->token.password.signature;
999 break;
1000 case ECRYPTFS_PRIVATE_KEY:
1001 (*sig) = auth_tok->token.private_key.signature;
1002 break;
1003 default:
1004 printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n",
1005 auth_tok->token_type);
1006 rc = -EINVAL;
1007 }
1008 return rc;
1009}
1010
Michael Halcrowdddfa462007-02-12 00:53:44 -08001011/**
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001012 * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok.
1013 * @auth_tok: The key authentication token used to decrypt the session key
1014 * @crypt_stat: The cryptographic context
Michael Halcrowdddfa462007-02-12 00:53:44 -08001015 *
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001016 * Returns zero on success; non-zero error otherwise.
Michael Halcrowdddfa462007-02-12 00:53:44 -08001017 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07001018static int
1019decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1020 struct ecryptfs_crypt_stat *crypt_stat)
Michael Halcrowdddfa462007-02-12 00:53:44 -08001021{
Trevor Highland19e66a62008-02-06 01:38:36 -08001022 u8 cipher_code = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001023 struct ecryptfs_msg_ctx *msg_ctx;
1024 struct ecryptfs_message *msg = NULL;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001025 char *auth_tok_sig;
Tyler Hicks624ae522008-10-15 22:02:51 -07001026 char *payload;
1027 size_t payload_len;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001028 int rc;
1029
Michael Halcrow5dda6992007-10-16 01:28:06 -07001030 rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok);
1031 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001032 printk(KERN_ERR "Unrecognized auth tok type: [%d]\n",
1033 auth_tok->token_type);
1034 goto out;
1035 }
1036 rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key),
Tyler Hicks624ae522008-10-15 22:02:51 -07001037 &payload, &payload_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001038 if (rc) {
Michael Halcrowf66e8832008-04-29 00:59:51 -07001039 ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001040 goto out;
1041 }
Tyler Hicks624ae522008-10-15 22:02:51 -07001042 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001043 if (rc) {
Tyler Hicks624ae522008-10-15 22:02:51 -07001044 ecryptfs_printk(KERN_ERR, "Error sending message to "
1045 "ecryptfsd\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001046 goto out;
1047 }
1048 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1049 if (rc) {
1050 ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet "
1051 "from the user space daemon\n");
1052 rc = -EIO;
1053 goto out;
1054 }
1055 rc = parse_tag_65_packet(&(auth_tok->session_key),
1056 &cipher_code, msg);
1057 if (rc) {
1058 printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n",
1059 rc);
1060 goto out;
1061 }
1062 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1063 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1064 auth_tok->session_key.decrypted_key_size);
1065 crypt_stat->key_size = auth_tok->session_key.decrypted_key_size;
1066 rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code);
1067 if (rc) {
1068 ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n",
1069 cipher_code)
1070 goto out;
1071 }
1072 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1073 if (ecryptfs_verbosity > 0) {
1074 ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n");
1075 ecryptfs_dump_hex(crypt_stat->key,
1076 crypt_stat->key_size);
1077 }
1078out:
1079 if (msg)
1080 kfree(msg);
1081 return rc;
1082}
1083
1084static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
1085{
Michael Halcrowdddfa462007-02-12 00:53:44 -08001086 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
Michael Halcrowe0869cc2007-10-16 01:27:55 -07001087 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001088
Michael Halcrowe0869cc2007-10-16 01:27:55 -07001089 list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp,
1090 auth_tok_list_head, list) {
1091 list_del(&auth_tok_list_item->list);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001092 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1093 auth_tok_list_item);
1094 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001095}
1096
1097struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
1098
Michael Halcrowdddfa462007-02-12 00:53:44 -08001099/**
1100 * parse_tag_1_packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001101 * @crypt_stat: The cryptographic context to modify based on packet contents
Michael Halcrowdddfa462007-02-12 00:53:44 -08001102 * @data: The raw bytes of the packet.
1103 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001104 * a new authentication token will be placed at the
1105 * end of this list for this packet.
Michael Halcrowdddfa462007-02-12 00:53:44 -08001106 * @new_auth_tok: Pointer to a pointer to memory that this function
1107 * allocates; sets the memory address of the pointer to
1108 * NULL on error. This object is added to the
1109 * auth_tok_list.
1110 * @packet_size: This function writes the size of the parsed packet
1111 * into this memory location; zero on error.
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001112 * @max_packet_size: The maximum allowable packet size
Michael Halcrowdddfa462007-02-12 00:53:44 -08001113 *
1114 * Returns zero on success; non-zero on error.
1115 */
1116static int
1117parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
1118 unsigned char *data, struct list_head *auth_tok_list,
1119 struct ecryptfs_auth_tok **new_auth_tok,
1120 size_t *packet_size, size_t max_packet_size)
1121{
1122 size_t body_size;
1123 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1124 size_t length_size;
1125 int rc = 0;
1126
1127 (*packet_size) = 0;
1128 (*new_auth_tok) = NULL;
Michael Halcrow132181792007-10-16 01:27:56 -07001129 /**
1130 * This format is inspired by OpenPGP; see RFC 2440
1131 * packet tag 1
1132 *
1133 * Tag 1 identifier (1 byte)
1134 * Max Tag 1 packet size (max 3 bytes)
1135 * Version (1 byte)
1136 * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE)
1137 * Cipher identifier (1 byte)
1138 * Encrypted key size (arbitrary)
1139 *
1140 * 12 bytes minimum packet size
Michael Halcrowdddfa462007-02-12 00:53:44 -08001141 */
Michael Halcrow132181792007-10-16 01:27:56 -07001142 if (unlikely(max_packet_size < 12)) {
1143 printk(KERN_ERR "Invalid max packet size; must be >=12\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001144 rc = -EINVAL;
1145 goto out;
1146 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001147 if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) {
Michael Halcrow132181792007-10-16 01:27:56 -07001148 printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n",
1149 ECRYPTFS_TAG_1_PACKET_TYPE);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001150 rc = -EINVAL;
1151 goto out;
1152 }
1153 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1154 * at end of function upon failure */
1155 auth_tok_list_item =
Michael Halcrow132181792007-10-16 01:27:56 -07001156 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache,
1157 GFP_KERNEL);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001158 if (!auth_tok_list_item) {
Michael Halcrow132181792007-10-16 01:27:56 -07001159 printk(KERN_ERR "Unable to allocate memory\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001160 rc = -ENOMEM;
1161 goto out;
1162 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001163 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001164 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1165 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001166 if (rc) {
Michael Halcrow132181792007-10-16 01:27:56 -07001167 printk(KERN_WARNING "Error parsing packet length; "
1168 "rc = [%d]\n", rc);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001169 goto out_free;
1170 }
Michael Halcrow132181792007-10-16 01:27:56 -07001171 if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001172 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001173 rc = -EINVAL;
1174 goto out_free;
1175 }
1176 (*packet_size) += length_size;
1177 if (unlikely((*packet_size) + body_size > max_packet_size)) {
Michael Halcrow132181792007-10-16 01:27:56 -07001178 printk(KERN_WARNING "Packet size exceeds max\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001179 rc = -EINVAL;
1180 goto out_free;
1181 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001182 if (unlikely(data[(*packet_size)++] != 0x03)) {
Michael Halcrow132181792007-10-16 01:27:56 -07001183 printk(KERN_WARNING "Unknown version number [%d]\n",
1184 data[(*packet_size) - 1]);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001185 rc = -EINVAL;
1186 goto out_free;
1187 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001188 ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
1189 &data[(*packet_size)], ECRYPTFS_SIG_SIZE);
1190 *packet_size += ECRYPTFS_SIG_SIZE;
1191 /* This byte is skipped because the kernel does not need to
1192 * know which public key encryption algorithm was used */
1193 (*packet_size)++;
1194 (*new_auth_tok)->session_key.encrypted_key_size =
Michael Halcrow132181792007-10-16 01:27:56 -07001195 body_size - (ECRYPTFS_SIG_SIZE + 2);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001196 if ((*new_auth_tok)->session_key.encrypted_key_size
1197 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
Michael Halcrow132181792007-10-16 01:27:56 -07001198 printk(KERN_WARNING "Tag 1 packet contains key larger "
1199 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001200 rc = -EINVAL;
1201 goto out;
1202 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08001203 memcpy((*new_auth_tok)->session_key.encrypted_key,
Michael Halcrow132181792007-10-16 01:27:56 -07001204 &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2)));
Michael Halcrowdddfa462007-02-12 00:53:44 -08001205 (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size;
1206 (*new_auth_tok)->session_key.flags &=
1207 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1208 (*new_auth_tok)->session_key.flags |=
1209 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
1210 (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY;
Michael Halcrow132181792007-10-16 01:27:56 -07001211 (*new_auth_tok)->flags = 0;
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001212 (*new_auth_tok)->session_key.flags &=
1213 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1214 (*new_auth_tok)->session_key.flags &=
1215 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001216 list_add(&auth_tok_list_item->list, auth_tok_list);
1217 goto out;
1218out_free:
1219 (*new_auth_tok) = NULL;
1220 memset(auth_tok_list_item, 0,
1221 sizeof(struct ecryptfs_auth_tok_list_item));
1222 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1223 auth_tok_list_item);
1224out:
1225 if (rc)
1226 (*packet_size) = 0;
1227 return rc;
1228}
1229
Michael Halcrow237fead2006-10-04 02:16:22 -07001230/**
1231 * parse_tag_3_packet
1232 * @crypt_stat: The cryptographic context to modify based on packet
1233 * contents.
1234 * @data: The raw bytes of the packet.
1235 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
1236 * a new authentication token will be placed at the end
1237 * of this list for this packet.
1238 * @new_auth_tok: Pointer to a pointer to memory that this function
1239 * allocates; sets the memory address of the pointer to
1240 * NULL on error. This object is added to the
1241 * auth_tok_list.
1242 * @packet_size: This function writes the size of the parsed packet
1243 * into this memory location; zero on error.
1244 * @max_packet_size: maximum number of bytes to parse
1245 *
1246 * Returns zero on success; non-zero on error.
1247 */
1248static int
1249parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
1250 unsigned char *data, struct list_head *auth_tok_list,
1251 struct ecryptfs_auth_tok **new_auth_tok,
1252 size_t *packet_size, size_t max_packet_size)
1253{
Michael Halcrow237fead2006-10-04 02:16:22 -07001254 size_t body_size;
1255 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1256 size_t length_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001257 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001258
1259 (*packet_size) = 0;
1260 (*new_auth_tok) = NULL;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001261 /**
1262 *This format is inspired by OpenPGP; see RFC 2440
1263 * packet tag 3
1264 *
1265 * Tag 3 identifier (1 byte)
1266 * Max Tag 3 packet size (max 3 bytes)
1267 * Version (1 byte)
1268 * Cipher code (1 byte)
1269 * S2K specifier (1 byte)
1270 * Hash identifier (1 byte)
1271 * Salt (ECRYPTFS_SALT_SIZE)
1272 * Hash iterations (1 byte)
1273 * Encrypted key (arbitrary)
1274 *
1275 * (ECRYPTFS_SALT_SIZE + 7) minimum packet size
Michael Halcrow237fead2006-10-04 02:16:22 -07001276 */
Michael Halcrowc59becf2007-10-16 01:27:56 -07001277 if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) {
1278 printk(KERN_ERR "Max packet size too large\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001279 rc = -EINVAL;
1280 goto out;
1281 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001282 if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001283 printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n",
1284 ECRYPTFS_TAG_3_PACKET_TYPE);
Michael Halcrow237fead2006-10-04 02:16:22 -07001285 rc = -EINVAL;
1286 goto out;
1287 }
1288 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1289 * at end of function upon failure */
1290 auth_tok_list_item =
Robert P. J. Dayc3762222007-02-10 01:45:03 -08001291 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
Michael Halcrow237fead2006-10-04 02:16:22 -07001292 if (!auth_tok_list_item) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001293 printk(KERN_ERR "Unable to allocate memory\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001294 rc = -ENOMEM;
1295 goto out;
1296 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001297 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001298 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1299 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001300 if (rc) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001301 printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n",
1302 rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07001303 goto out_free;
1304 }
Michael Halcrowc59becf2007-10-16 01:27:56 -07001305 if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001306 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001307 rc = -EINVAL;
1308 goto out_free;
1309 }
1310 (*packet_size) += length_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07001311 if (unlikely((*packet_size) + body_size > max_packet_size)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001312 printk(KERN_ERR "Packet size exceeds max\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001313 rc = -EINVAL;
1314 goto out_free;
1315 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001316 (*new_auth_tok)->session_key.encrypted_key_size =
Michael Halcrowc59becf2007-10-16 01:27:56 -07001317 (body_size - (ECRYPTFS_SALT_SIZE + 5));
Ramon de Carvalho Vallef151cd22009-07-28 13:58:22 -05001318 if ((*new_auth_tok)->session_key.encrypted_key_size
1319 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
1320 printk(KERN_WARNING "Tag 3 packet contains key larger "
1321 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n");
1322 rc = -EINVAL;
1323 goto out_free;
1324 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001325 if (unlikely(data[(*packet_size)++] != 0x04)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001326 printk(KERN_WARNING "Unknown version number [%d]\n",
1327 data[(*packet_size) - 1]);
Michael Halcrow237fead2006-10-04 02:16:22 -07001328 rc = -EINVAL;
1329 goto out_free;
1330 }
Tyler Hicksb0105ea2009-08-11 00:36:32 -05001331 rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher,
1332 (u16)data[(*packet_size)]);
1333 if (rc)
1334 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07001335 /* A little extra work to differentiate among the AES key
1336 * sizes; see RFC2440 */
1337 switch(data[(*packet_size)++]) {
1338 case RFC2440_CIPHER_AES_192:
1339 crypt_stat->key_size = 24;
1340 break;
1341 default:
1342 crypt_stat->key_size =
1343 (*new_auth_tok)->session_key.encrypted_key_size;
1344 }
Tyler Hicksb0105ea2009-08-11 00:36:32 -05001345 rc = ecryptfs_init_crypt_ctx(crypt_stat);
1346 if (rc)
1347 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07001348 if (unlikely(data[(*packet_size)++] != 0x03)) {
Michael Halcrowc59becf2007-10-16 01:27:56 -07001349 printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001350 rc = -ENOSYS;
1351 goto out_free;
1352 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001353 /* TODO: finish the hash mapping */
Michael Halcrow237fead2006-10-04 02:16:22 -07001354 switch (data[(*packet_size)++]) {
1355 case 0x01: /* See RFC2440 for these numbers and their mappings */
1356 /* Choose MD5 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001357 memcpy((*new_auth_tok)->token.password.salt,
1358 &data[(*packet_size)], ECRYPTFS_SALT_SIZE);
1359 (*packet_size) += ECRYPTFS_SALT_SIZE;
Michael Halcrow237fead2006-10-04 02:16:22 -07001360 /* This conversion was taken straight from RFC2440 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001361 (*new_auth_tok)->token.password.hash_iterations =
1362 ((u32) 16 + (data[(*packet_size)] & 15))
1363 << ((data[(*packet_size)] >> 4) + 6);
1364 (*packet_size)++;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001365 /* Friendly reminder:
1366 * (*new_auth_tok)->session_key.encrypted_key_size =
1367 * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */
Michael Halcrow237fead2006-10-04 02:16:22 -07001368 memcpy((*new_auth_tok)->session_key.encrypted_key,
1369 &data[(*packet_size)],
1370 (*new_auth_tok)->session_key.encrypted_key_size);
1371 (*packet_size) +=
1372 (*new_auth_tok)->session_key.encrypted_key_size;
1373 (*new_auth_tok)->session_key.flags &=
1374 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1375 (*new_auth_tok)->session_key.flags |=
1376 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
Michael Halcrowc59becf2007-10-16 01:27:56 -07001377 (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */
Michael Halcrow237fead2006-10-04 02:16:22 -07001378 break;
1379 default:
1380 ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: "
1381 "[%d]\n", data[(*packet_size) - 1]);
1382 rc = -ENOSYS;
1383 goto out_free;
1384 }
1385 (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD;
1386 /* TODO: Parametarize; we might actually want userspace to
1387 * decrypt the session key. */
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001388 (*new_auth_tok)->session_key.flags &=
1389 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1390 (*new_auth_tok)->session_key.flags &=
1391 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
Michael Halcrow237fead2006-10-04 02:16:22 -07001392 list_add(&auth_tok_list_item->list, auth_tok_list);
1393 goto out;
1394out_free:
1395 (*new_auth_tok) = NULL;
1396 memset(auth_tok_list_item, 0,
1397 sizeof(struct ecryptfs_auth_tok_list_item));
1398 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1399 auth_tok_list_item);
1400out:
1401 if (rc)
1402 (*packet_size) = 0;
1403 return rc;
1404}
1405
1406/**
1407 * parse_tag_11_packet
1408 * @data: The raw bytes of the packet
1409 * @contents: This function writes the data contents of the literal
1410 * packet into this memory location
1411 * @max_contents_bytes: The maximum number of bytes that this function
1412 * is allowed to write into contents
1413 * @tag_11_contents_size: This function writes the size of the parsed
1414 * contents into this memory location; zero on
1415 * error
1416 * @packet_size: This function writes the size of the parsed packet
1417 * into this memory location; zero on error
1418 * @max_packet_size: maximum number of bytes to parse
1419 *
1420 * Returns zero on success; non-zero on error.
1421 */
1422static int
1423parse_tag_11_packet(unsigned char *data, unsigned char *contents,
1424 size_t max_contents_bytes, size_t *tag_11_contents_size,
1425 size_t *packet_size, size_t max_packet_size)
1426{
Michael Halcrow237fead2006-10-04 02:16:22 -07001427 size_t body_size;
1428 size_t length_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001429 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001430
1431 (*packet_size) = 0;
1432 (*tag_11_contents_size) = 0;
Michael Halcrowf6481042007-10-16 01:27:57 -07001433 /* This format is inspired by OpenPGP; see RFC 2440
1434 * packet tag 11
1435 *
1436 * Tag 11 identifier (1 byte)
1437 * Max Tag 11 packet size (max 3 bytes)
1438 * Binary format specifier (1 byte)
1439 * Filename length (1 byte)
1440 * Filename ("_CONSOLE") (8 bytes)
1441 * Modification date (4 bytes)
1442 * Literal data (arbitrary)
1443 *
1444 * We need at least 16 bytes of data for the packet to even be
1445 * valid.
Michael Halcrow237fead2006-10-04 02:16:22 -07001446 */
Michael Halcrowf6481042007-10-16 01:27:57 -07001447 if (max_packet_size < 16) {
1448 printk(KERN_ERR "Maximum packet size too small\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001449 rc = -EINVAL;
1450 goto out;
1451 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001452 if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001453 printk(KERN_WARNING "Invalid tag 11 packet format\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001454 rc = -EINVAL;
1455 goto out;
1456 }
Michael Halcrowf66e8832008-04-29 00:59:51 -07001457 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1458 &length_size);
Michael Halcrow5dda6992007-10-16 01:28:06 -07001459 if (rc) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001460 printk(KERN_WARNING "Invalid tag 11 packet format\n");
1461 goto out;
1462 }
1463 if (body_size < 14) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07001464 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
Michael Halcrowf6481042007-10-16 01:27:57 -07001465 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07001466 goto out;
1467 }
1468 (*packet_size) += length_size;
Michael Halcrowf6481042007-10-16 01:27:57 -07001469 (*tag_11_contents_size) = (body_size - 14);
Michael Halcrow237fead2006-10-04 02:16:22 -07001470 if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001471 printk(KERN_ERR "Packet size exceeds max\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001472 rc = -EINVAL;
1473 goto out;
1474 }
Tyler Hicks6352a292009-07-28 13:57:01 -05001475 if (unlikely((*tag_11_contents_size) > max_contents_bytes)) {
1476 printk(KERN_ERR "Literal data section in tag 11 packet exceeds "
1477 "expected size\n");
1478 rc = -EINVAL;
1479 goto out;
1480 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001481 if (data[(*packet_size)++] != 0x62) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001482 printk(KERN_WARNING "Unrecognizable packet\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001483 rc = -EINVAL;
1484 goto out;
1485 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001486 if (data[(*packet_size)++] != 0x08) {
Michael Halcrowf6481042007-10-16 01:27:57 -07001487 printk(KERN_WARNING "Unrecognizable packet\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001488 rc = -EINVAL;
1489 goto out;
1490 }
Michael Halcrowf6481042007-10-16 01:27:57 -07001491 (*packet_size) += 12; /* Ignore filename and modification date */
Michael Halcrow237fead2006-10-04 02:16:22 -07001492 memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size));
1493 (*packet_size) += (*tag_11_contents_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001494out:
1495 if (rc) {
1496 (*packet_size) = 0;
1497 (*tag_11_contents_size) = 0;
1498 }
1499 return rc;
1500}
1501
1502/**
Michael Halcrowf4aad162007-10-16 01:27:53 -07001503 * ecryptfs_verify_version
1504 * @version: The version number to confirm
1505 *
1506 * Returns zero on good version; non-zero otherwise
1507 */
1508static int ecryptfs_verify_version(u16 version)
1509{
1510 int rc = 0;
1511 unsigned char major;
1512 unsigned char minor;
1513
1514 major = ((version >> 8) & 0xFF);
1515 minor = (version & 0xFF);
1516 if (major != ECRYPTFS_VERSION_MAJOR) {
1517 ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
1518 "Expected [%d]; got [%d]\n",
1519 ECRYPTFS_VERSION_MAJOR, major);
1520 rc = -EINVAL;
1521 goto out;
1522 }
1523 if (minor != ECRYPTFS_VERSION_MINOR) {
1524 ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
1525 "Expected [%d]; got [%d]\n",
1526 ECRYPTFS_VERSION_MINOR, minor);
1527 rc = -EINVAL;
1528 goto out;
1529 }
1530out:
1531 return rc;
1532}
1533
1534int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
1535 struct ecryptfs_auth_tok **auth_tok,
1536 char *sig)
1537{
1538 int rc = 0;
1539
1540 (*auth_tok_key) = request_key(&key_type_user, sig, NULL);
1541 if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
1542 printk(KERN_ERR "Could not find key with description: [%s]\n",
1543 sig);
Eric Sandeen982363c2008-07-23 21:30:04 -07001544 rc = process_request_key_err(PTR_ERR(*auth_tok_key));
Michael Halcrowf4aad162007-10-16 01:27:53 -07001545 goto out;
1546 }
1547 (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key);
1548 if (ecryptfs_verify_version((*auth_tok)->version)) {
1549 printk(KERN_ERR
1550 "Data structure version mismatch. "
1551 "Userspace tools must match eCryptfs "
1552 "kernel module with major version [%d] "
1553 "and minor version [%d]\n",
1554 ECRYPTFS_VERSION_MAJOR,
1555 ECRYPTFS_VERSION_MINOR);
1556 rc = -EINVAL;
1557 goto out;
1558 }
1559 if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
1560 && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
1561 printk(KERN_ERR "Invalid auth_tok structure "
1562 "returned from key query\n");
1563 rc = -EINVAL;
1564 goto out;
1565 }
1566out:
1567 return rc;
1568}
1569
1570/**
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001571 * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok.
1572 * @auth_tok: The passphrase authentication token to use to encrypt the FEK
1573 * @crypt_stat: The cryptographic context
Michael Halcrow237fead2006-10-04 02:16:22 -07001574 *
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001575 * Returns zero on success; non-zero error otherwise
Michael Halcrow237fead2006-10-04 02:16:22 -07001576 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07001577static int
1578decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1579 struct ecryptfs_crypt_stat *crypt_stat)
Michael Halcrow237fead2006-10-04 02:16:22 -07001580{
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001581 struct scatterlist dst_sg[2];
1582 struct scatterlist src_sg[2];
Michael Halcrowdd8e2902007-10-16 01:28:03 -07001583 struct mutex *tfm_mutex;
Michael Halcrow8bba0662006-10-30 22:07:18 -08001584 struct blkcipher_desc desc = {
1585 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
1586 };
1587 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001588
Michael Halcrowf4aad162007-10-16 01:27:53 -07001589 if (unlikely(ecryptfs_verbosity > 0)) {
1590 ecryptfs_printk(
1591 KERN_DEBUG, "Session key encryption key (size [%d]):\n",
1592 auth_tok->token.password.session_key_encryption_key_bytes);
1593 ecryptfs_dump_hex(
1594 auth_tok->token.password.session_key_encryption_key,
1595 auth_tok->token.password.session_key_encryption_key_bytes);
Michael Halcrow237fead2006-10-04 02:16:22 -07001596 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001597 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
1598 crypt_stat->cipher);
1599 if (unlikely(rc)) {
1600 printk(KERN_ERR "Internal error whilst attempting to get "
1601 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1602 crypt_stat->cipher, rc);
1603 goto out;
1604 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07001605 rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
1606 auth_tok->session_key.encrypted_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001607 src_sg, 2);
1608 if (rc < 1 || rc > 2) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001609 printk(KERN_ERR "Internal error whilst attempting to convert "
1610 "auth_tok->session_key.encrypted_key to scatterlist; "
1611 "expected rc = 1; got rc = [%d]. "
1612 "auth_tok->session_key.encrypted_key_size = [%d]\n", rc,
1613 auth_tok->session_key.encrypted_key_size);
1614 goto out;
1615 }
1616 auth_tok->session_key.decrypted_key_size =
1617 auth_tok->session_key.encrypted_key_size;
Michael Halcrow5dda6992007-10-16 01:28:06 -07001618 rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key,
1619 auth_tok->session_key.decrypted_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001620 dst_sg, 2);
1621 if (rc < 1 || rc > 2) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001622 printk(KERN_ERR "Internal error whilst attempting to convert "
1623 "auth_tok->session_key.decrypted_key to scatterlist; "
1624 "expected rc = 1; got rc = [%d]\n", rc);
1625 goto out;
1626 }
1627 mutex_lock(tfm_mutex);
1628 rc = crypto_blkcipher_setkey(
1629 desc.tfm, auth_tok->token.password.session_key_encryption_key,
1630 crypt_stat->key_size);
1631 if (unlikely(rc < 0)) {
1632 mutex_unlock(tfm_mutex);
Michael Halcrowe5d9cbd2006-10-30 22:07:16 -08001633 printk(KERN_ERR "Error setting key for crypto context\n");
1634 rc = -EINVAL;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001635 goto out;
Michael Halcrowe5d9cbd2006-10-30 22:07:16 -08001636 }
Michael Halcrowac97b9f2008-11-19 15:36:28 -08001637 rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg,
Michael Halcrow8bba0662006-10-30 22:07:18 -08001638 auth_tok->session_key.encrypted_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001639 mutex_unlock(tfm_mutex);
1640 if (unlikely(rc)) {
Michael Halcrow8bba0662006-10-30 22:07:18 -08001641 printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001642 goto out;
Michael Halcrow8bba0662006-10-30 22:07:18 -08001643 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001644 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1645 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1646 auth_tok->session_key.decrypted_key_size);
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001647 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001648 if (unlikely(ecryptfs_verbosity > 0)) {
1649 ecryptfs_printk(KERN_DEBUG, "FEK of size [%d]:\n",
1650 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07001651 ecryptfs_dump_hex(crypt_stat->key,
1652 crypt_stat->key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001653 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001654out:
1655 return rc;
1656}
1657
1658/**
1659 * ecryptfs_parse_packet_set
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001660 * @crypt_stat: The cryptographic context
1661 * @src: Virtual address of region of memory containing the packets
1662 * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set
Michael Halcrow237fead2006-10-04 02:16:22 -07001663 *
1664 * Get crypt_stat to have the file's session key if the requisite key
1665 * is available to decrypt the session key.
1666 *
1667 * Returns Zero if a valid authentication token was retrieved and
1668 * processed; negative value for file not encrypted or for error
1669 * conditions.
1670 */
1671int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
1672 unsigned char *src,
1673 struct dentry *ecryptfs_dentry)
1674{
1675 size_t i = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001676 size_t found_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07001677 size_t next_packet_is_auth_tok_packet;
Michael Halcrow237fead2006-10-04 02:16:22 -07001678 struct list_head auth_tok_list;
Michael Halcrowdd8e2902007-10-16 01:28:03 -07001679 struct ecryptfs_auth_tok *matching_auth_tok;
1680 struct ecryptfs_auth_tok *candidate_auth_tok;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001681 char *candidate_auth_tok_sig;
Michael Halcrow237fead2006-10-04 02:16:22 -07001682 size_t packet_size;
1683 struct ecryptfs_auth_tok *new_auth_tok;
1684 unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE];
Michael Halcrowf4aad162007-10-16 01:27:53 -07001685 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
Michael Halcrow237fead2006-10-04 02:16:22 -07001686 size_t tag_11_contents_size;
1687 size_t tag_11_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001688 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07001689
1690 INIT_LIST_HEAD(&auth_tok_list);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001691 /* Parse the header to find as many packets as we can; these will be
Michael Halcrow237fead2006-10-04 02:16:22 -07001692 * added the our &auth_tok_list */
1693 next_packet_is_auth_tok_packet = 1;
1694 while (next_packet_is_auth_tok_packet) {
1695 size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i);
1696
1697 switch (src[i]) {
1698 case ECRYPTFS_TAG_3_PACKET_TYPE:
1699 rc = parse_tag_3_packet(crypt_stat,
1700 (unsigned char *)&src[i],
1701 &auth_tok_list, &new_auth_tok,
1702 &packet_size, max_packet_size);
1703 if (rc) {
1704 ecryptfs_printk(KERN_ERR, "Error parsing "
1705 "tag 3 packet\n");
1706 rc = -EIO;
1707 goto out_wipe_list;
1708 }
1709 i += packet_size;
1710 rc = parse_tag_11_packet((unsigned char *)&src[i],
1711 sig_tmp_space,
1712 ECRYPTFS_SIG_SIZE,
1713 &tag_11_contents_size,
1714 &tag_11_packet_size,
1715 max_packet_size);
1716 if (rc) {
1717 ecryptfs_printk(KERN_ERR, "No valid "
1718 "(ecryptfs-specific) literal "
1719 "packet containing "
1720 "authentication token "
1721 "signature found after "
1722 "tag 3 packet\n");
1723 rc = -EIO;
1724 goto out_wipe_list;
1725 }
1726 i += tag_11_packet_size;
1727 if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) {
1728 ecryptfs_printk(KERN_ERR, "Expected "
1729 "signature of size [%d]; "
1730 "read size [%d]\n",
1731 ECRYPTFS_SIG_SIZE,
1732 tag_11_contents_size);
1733 rc = -EIO;
1734 goto out_wipe_list;
1735 }
1736 ecryptfs_to_hex(new_auth_tok->token.password.signature,
1737 sig_tmp_space, tag_11_contents_size);
1738 new_auth_tok->token.password.signature[
1739 ECRYPTFS_PASSWORD_SIG_SIZE] = '\0';
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001740 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
Michael Halcrow237fead2006-10-04 02:16:22 -07001741 break;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001742 case ECRYPTFS_TAG_1_PACKET_TYPE:
1743 rc = parse_tag_1_packet(crypt_stat,
1744 (unsigned char *)&src[i],
1745 &auth_tok_list, &new_auth_tok,
1746 &packet_size, max_packet_size);
1747 if (rc) {
1748 ecryptfs_printk(KERN_ERR, "Error parsing "
1749 "tag 1 packet\n");
1750 rc = -EIO;
1751 goto out_wipe_list;
1752 }
1753 i += packet_size;
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001754 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001755 break;
Michael Halcrow237fead2006-10-04 02:16:22 -07001756 case ECRYPTFS_TAG_11_PACKET_TYPE:
1757 ecryptfs_printk(KERN_WARNING, "Invalid packet set "
1758 "(Tag 11 not allowed by itself)\n");
1759 rc = -EIO;
1760 goto out_wipe_list;
1761 break;
1762 default:
1763 ecryptfs_printk(KERN_DEBUG, "No packet at offset "
1764 "[%d] of the file header; hex value of "
1765 "character is [0x%.2x]\n", i, src[i]);
1766 next_packet_is_auth_tok_packet = 0;
1767 }
1768 }
1769 if (list_empty(&auth_tok_list)) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001770 printk(KERN_ERR "The lower file appears to be a non-encrypted "
1771 "eCryptfs file; this is not supported in this version "
1772 "of the eCryptfs kernel module\n");
1773 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07001774 goto out;
1775 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001776 /* auth_tok_list contains the set of authentication tokens
1777 * parsed from the metadata. We need to find a matching
1778 * authentication token that has the secret component(s)
1779 * necessary to decrypt the EFEK in the auth_tok parsed from
1780 * the metadata. There may be several potential matches, but
1781 * just one will be sufficient to decrypt to get the FEK. */
1782find_next_matching_auth_tok:
1783 found_auth_tok = 0;
1784 list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001785 candidate_auth_tok = &auth_tok_list_item->auth_tok;
1786 if (unlikely(ecryptfs_verbosity > 0)) {
1787 ecryptfs_printk(KERN_DEBUG,
1788 "Considering cadidate auth tok:\n");
1789 ecryptfs_dump_auth_tok(candidate_auth_tok);
1790 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07001791 rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig,
1792 candidate_auth_tok);
1793 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001794 printk(KERN_ERR
1795 "Unrecognized candidate auth tok type: [%d]\n",
1796 candidate_auth_tok->token_type);
1797 rc = -EINVAL;
1798 goto out_wipe_list;
1799 }
Michael Halcrow9c79f342009-01-06 14:41:57 -08001800 ecryptfs_find_auth_tok_for_sig(&matching_auth_tok,
1801 crypt_stat->mount_crypt_stat,
Michael Halcrow5dda6992007-10-16 01:28:06 -07001802 candidate_auth_tok_sig);
Michael Halcrowf4aad162007-10-16 01:27:53 -07001803 if (matching_auth_tok) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001804 found_auth_tok = 1;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001805 goto found_matching_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07001806 }
1807 }
Michael Halcrow237fead2006-10-04 02:16:22 -07001808 if (!found_auth_tok) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001809 ecryptfs_printk(KERN_ERR, "Could not find a usable "
1810 "authentication token\n");
Michael Halcrow237fead2006-10-04 02:16:22 -07001811 rc = -EIO;
1812 goto out_wipe_list;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001813 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07001814found_matching_auth_tok:
Michael Halcrowe2bd99e2007-02-12 00:53:49 -08001815 if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
Michael Halcrowdddfa462007-02-12 00:53:44 -08001816 memcpy(&(candidate_auth_tok->token.private_key),
Michael Halcrowf4aad162007-10-16 01:27:53 -07001817 &(matching_auth_tok->token.private_key),
Michael Halcrowdddfa462007-02-12 00:53:44 -08001818 sizeof(struct ecryptfs_private_key));
Michael Halcrowf4aad162007-10-16 01:27:53 -07001819 rc = decrypt_pki_encrypted_session_key(candidate_auth_tok,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001820 crypt_stat);
1821 } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
Michael Halcrow237fead2006-10-04 02:16:22 -07001822 memcpy(&(candidate_auth_tok->token.password),
Michael Halcrowf4aad162007-10-16 01:27:53 -07001823 &(matching_auth_tok->token.password),
Michael Halcrow237fead2006-10-04 02:16:22 -07001824 sizeof(struct ecryptfs_password));
Michael Halcrowf4aad162007-10-16 01:27:53 -07001825 rc = decrypt_passphrase_encrypted_session_key(
1826 candidate_auth_tok, crypt_stat);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001827 }
1828 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07001829 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1830
1831 ecryptfs_printk(KERN_WARNING, "Error decrypting the "
1832 "session key for authentication token with sig "
1833 "[%.*s]; rc = [%d]. Removing auth tok "
1834 "candidate from the list and searching for "
1835 "the next match.\n", candidate_auth_tok_sig,
1836 ECRYPTFS_SIG_SIZE_HEX, rc);
1837 list_for_each_entry_safe(auth_tok_list_item,
1838 auth_tok_list_item_tmp,
1839 &auth_tok_list, list) {
1840 if (candidate_auth_tok
1841 == &auth_tok_list_item->auth_tok) {
1842 list_del(&auth_tok_list_item->list);
1843 kmem_cache_free(
1844 ecryptfs_auth_tok_list_item_cache,
1845 auth_tok_list_item);
1846 goto find_next_matching_auth_tok;
1847 }
1848 }
1849 BUG();
Michael Halcrowdddfa462007-02-12 00:53:44 -08001850 }
1851 rc = ecryptfs_compute_root_iv(crypt_stat);
1852 if (rc) {
1853 ecryptfs_printk(KERN_ERR, "Error computing "
1854 "the root IV\n");
1855 goto out_wipe_list;
Michael Halcrow237fead2006-10-04 02:16:22 -07001856 }
1857 rc = ecryptfs_init_crypt_ctx(crypt_stat);
1858 if (rc) {
1859 ecryptfs_printk(KERN_ERR, "Error initializing crypto "
1860 "context for cipher [%s]; rc = [%d]\n",
1861 crypt_stat->cipher, rc);
1862 }
1863out_wipe_list:
1864 wipe_auth_tok_list(&auth_tok_list);
1865out:
1866 return rc;
1867}
Michael Halcrowf4aad162007-10-16 01:27:53 -07001868
Michael Halcrowdddfa462007-02-12 00:53:44 -08001869static int
1870pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
1871 struct ecryptfs_crypt_stat *crypt_stat,
1872 struct ecryptfs_key_record *key_rec)
1873{
1874 struct ecryptfs_msg_ctx *msg_ctx = NULL;
Tyler Hicks624ae522008-10-15 22:02:51 -07001875 char *payload = NULL;
1876 size_t payload_len;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001877 struct ecryptfs_message *msg;
1878 int rc;
1879
1880 rc = write_tag_66_packet(auth_tok->token.private_key.signature,
Michael Halcrow9c79f342009-01-06 14:41:57 -08001881 ecryptfs_code_for_cipher_string(
1882 crypt_stat->cipher,
1883 crypt_stat->key_size),
Tyler Hicks624ae522008-10-15 22:02:51 -07001884 crypt_stat, &payload, &payload_len);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001885 if (rc) {
1886 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
1887 goto out;
1888 }
Tyler Hicks624ae522008-10-15 22:02:51 -07001889 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001890 if (rc) {
Tyler Hicks624ae522008-10-15 22:02:51 -07001891 ecryptfs_printk(KERN_ERR, "Error sending message to "
1892 "ecryptfsd\n");
Michael Halcrowdddfa462007-02-12 00:53:44 -08001893 goto out;
1894 }
1895 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1896 if (rc) {
1897 ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet "
1898 "from the user space daemon\n");
1899 rc = -EIO;
1900 goto out;
1901 }
1902 rc = parse_tag_67_packet(key_rec, msg);
1903 if (rc)
1904 ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n");
1905 kfree(msg);
1906out:
Tyler Hicks624ae522008-10-15 22:02:51 -07001907 kfree(payload);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001908 return rc;
1909}
1910/**
1911 * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet
1912 * @dest: Buffer into which to write the packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07001913 * @remaining_bytes: Maximum number of bytes that can be writtn
1914 * @auth_tok: The authentication token used for generating the tag 1 packet
1915 * @crypt_stat: The cryptographic context
1916 * @key_rec: The key record struct for the tag 1 packet
Michael Halcrowdddfa462007-02-12 00:53:44 -08001917 * @packet_size: This function will write the number of bytes that end
1918 * up constituting the packet; set to zero on error
1919 *
1920 * Returns zero on success; non-zero on error.
1921 */
1922static int
Michael Halcrowf4aad162007-10-16 01:27:53 -07001923write_tag_1_packet(char *dest, size_t *remaining_bytes,
1924 struct ecryptfs_auth_tok *auth_tok,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001925 struct ecryptfs_crypt_stat *crypt_stat,
Michael Halcrowdddfa462007-02-12 00:53:44 -08001926 struct ecryptfs_key_record *key_rec, size_t *packet_size)
1927{
1928 size_t i;
1929 size_t encrypted_session_key_valid = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001930 size_t packet_size_length;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001931 size_t max_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08001932 int rc = 0;
1933
1934 (*packet_size) = 0;
1935 ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature,
1936 ECRYPTFS_SIG_SIZE);
1937 encrypted_session_key_valid = 0;
1938 for (i = 0; i < crypt_stat->key_size; i++)
1939 encrypted_session_key_valid |=
1940 auth_tok->session_key.encrypted_key[i];
1941 if (encrypted_session_key_valid) {
1942 memcpy(key_rec->enc_key,
1943 auth_tok->session_key.encrypted_key,
1944 auth_tok->session_key.encrypted_key_size);
1945 goto encrypted_session_key_set;
1946 }
1947 if (auth_tok->session_key.encrypted_key_size == 0)
1948 auth_tok->session_key.encrypted_key_size =
1949 auth_tok->token.private_key.key_size;
1950 rc = pki_encrypt_session_key(auth_tok, crypt_stat, key_rec);
1951 if (rc) {
Michael Halcrowf66e8832008-04-29 00:59:51 -07001952 printk(KERN_ERR "Failed to encrypt session key via a key "
1953 "module; rc = [%d]\n", rc);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001954 goto out;
1955 }
1956 if (ecryptfs_verbosity > 0) {
1957 ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n");
1958 ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size);
1959 }
1960encrypted_session_key_set:
Michael Halcrowf4aad162007-10-16 01:27:53 -07001961 /* This format is inspired by OpenPGP; see RFC 2440
1962 * packet tag 1 */
1963 max_packet_size = (1 /* Tag 1 identifier */
1964 + 3 /* Max Tag 1 packet size */
1965 + 1 /* Version */
1966 + ECRYPTFS_SIG_SIZE /* Key identifier */
1967 + 1 /* Cipher identifier */
1968 + key_rec->enc_key_size); /* Encrypted key size */
1969 if (max_packet_size > (*remaining_bytes)) {
1970 printk(KERN_ERR "Packet length larger than maximum allowable; "
Andrew Morton81acbcd2007-10-16 01:27:59 -07001971 "need up to [%td] bytes, but there are only [%td] "
Michael Halcrowf4aad162007-10-16 01:27:53 -07001972 "available\n", max_packet_size, (*remaining_bytes));
Michael Halcrowdddfa462007-02-12 00:53:44 -08001973 rc = -EINVAL;
1974 goto out;
1975 }
1976 dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -07001977 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
1978 (max_packet_size - 4),
1979 &packet_size_length);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001980 if (rc) {
1981 ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet "
1982 "header; cannot generate packet length\n");
1983 goto out;
1984 }
1985 (*packet_size) += packet_size_length;
1986 dest[(*packet_size)++] = 0x03; /* version 3 */
1987 memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE);
1988 (*packet_size) += ECRYPTFS_SIG_SIZE;
1989 dest[(*packet_size)++] = RFC2440_CIPHER_RSA;
1990 memcpy(&dest[(*packet_size)], key_rec->enc_key,
1991 key_rec->enc_key_size);
1992 (*packet_size) += key_rec->enc_key_size;
1993out:
1994 if (rc)
1995 (*packet_size) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07001996 else
1997 (*remaining_bytes) -= (*packet_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08001998 return rc;
1999}
Michael Halcrow237fead2006-10-04 02:16:22 -07002000
2001/**
2002 * write_tag_11_packet
2003 * @dest: Target into which Tag 11 packet is to be written
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002004 * @remaining_bytes: Maximum packet length
Michael Halcrow237fead2006-10-04 02:16:22 -07002005 * @contents: Byte array of contents to copy in
2006 * @contents_length: Number of bytes in contents
2007 * @packet_length: Length of the Tag 11 packet written; zero on error
2008 *
2009 * Returns zero on success; non-zero on error.
2010 */
2011static int
Andrew Morton81acbcd2007-10-16 01:27:59 -07002012write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents,
Michael Halcrow146a4602007-10-16 01:27:58 -07002013 size_t contents_length, size_t *packet_length)
Michael Halcrow237fead2006-10-04 02:16:22 -07002014{
Michael Halcrow237fead2006-10-04 02:16:22 -07002015 size_t packet_size_length;
Michael Halcrow146a4602007-10-16 01:27:58 -07002016 size_t max_packet_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002017 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002018
2019 (*packet_length) = 0;
Michael Halcrow146a4602007-10-16 01:27:58 -07002020 /* This format is inspired by OpenPGP; see RFC 2440
2021 * packet tag 11 */
2022 max_packet_size = (1 /* Tag 11 identifier */
2023 + 3 /* Max Tag 11 packet size */
2024 + 1 /* Binary format specifier */
2025 + 1 /* Filename length */
2026 + 8 /* Filename ("_CONSOLE") */
2027 + 4 /* Modification date */
2028 + contents_length); /* Literal data */
2029 if (max_packet_size > (*remaining_bytes)) {
2030 printk(KERN_ERR "Packet length larger than maximum allowable; "
Andrew Morton81acbcd2007-10-16 01:27:59 -07002031 "need up to [%td] bytes, but there are only [%td] "
Michael Halcrow146a4602007-10-16 01:27:58 -07002032 "available\n", max_packet_size, (*remaining_bytes));
Michael Halcrow237fead2006-10-04 02:16:22 -07002033 rc = -EINVAL;
Michael Halcrow237fead2006-10-04 02:16:22 -07002034 goto out;
2035 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002036 dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE;
Michael Halcrowf66e8832008-04-29 00:59:51 -07002037 rc = ecryptfs_write_packet_length(&dest[(*packet_length)],
2038 (max_packet_size - 4),
2039 &packet_size_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002040 if (rc) {
Michael Halcrow146a4602007-10-16 01:27:58 -07002041 printk(KERN_ERR "Error generating tag 11 packet header; cannot "
2042 "generate packet length. rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002043 goto out;
2044 }
2045 (*packet_length) += packet_size_length;
Michael Halcrow146a4602007-10-16 01:27:58 -07002046 dest[(*packet_length)++] = 0x62; /* binary data format specifier */
Michael Halcrow237fead2006-10-04 02:16:22 -07002047 dest[(*packet_length)++] = 8;
2048 memcpy(&dest[(*packet_length)], "_CONSOLE", 8);
2049 (*packet_length) += 8;
Michael Halcrow237fead2006-10-04 02:16:22 -07002050 memset(&dest[(*packet_length)], 0x00, 4);
2051 (*packet_length) += 4;
Michael Halcrow237fead2006-10-04 02:16:22 -07002052 memcpy(&dest[(*packet_length)], contents, contents_length);
2053 (*packet_length) += contents_length;
2054 out:
2055 if (rc)
2056 (*packet_length) = 0;
Michael Halcrow146a4602007-10-16 01:27:58 -07002057 else
2058 (*remaining_bytes) -= (*packet_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002059 return rc;
2060}
2061
2062/**
2063 * write_tag_3_packet
2064 * @dest: Buffer into which to write the packet
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002065 * @remaining_bytes: Maximum number of bytes that can be written
Michael Halcrow237fead2006-10-04 02:16:22 -07002066 * @auth_tok: Authentication token
2067 * @crypt_stat: The cryptographic context
2068 * @key_rec: encrypted key
2069 * @packet_size: This function will write the number of bytes that end
2070 * up constituting the packet; set to zero on error
2071 *
2072 * Returns zero on success; non-zero on error.
2073 */
2074static int
Michael Halcrowf4aad162007-10-16 01:27:53 -07002075write_tag_3_packet(char *dest, size_t *remaining_bytes,
2076 struct ecryptfs_auth_tok *auth_tok,
Michael Halcrow237fead2006-10-04 02:16:22 -07002077 struct ecryptfs_crypt_stat *crypt_stat,
2078 struct ecryptfs_key_record *key_rec, size_t *packet_size)
2079{
Michael Halcrow237fead2006-10-04 02:16:22 -07002080 size_t i;
Michael Halcrow237fead2006-10-04 02:16:22 -07002081 size_t encrypted_session_key_valid = 0;
2082 char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002083 struct scatterlist dst_sg[2];
2084 struct scatterlist src_sg[2];
Michael Halcrow237fead2006-10-04 02:16:22 -07002085 struct mutex *tfm_mutex = NULL;
Trevor Highland19e66a62008-02-06 01:38:36 -08002086 u8 cipher_code;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002087 size_t packet_size_length;
2088 size_t max_packet_size;
2089 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2090 crypt_stat->mount_crypt_stat;
Michael Halcrow8bba0662006-10-30 22:07:18 -08002091 struct blkcipher_desc desc = {
2092 .tfm = NULL,
2093 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
2094 };
2095 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002096
2097 (*packet_size) = 0;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002098 ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
Michael Halcrow237fead2006-10-04 02:16:22 -07002099 ECRYPTFS_SIG_SIZE);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002100 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
2101 crypt_stat->cipher);
2102 if (unlikely(rc)) {
2103 printk(KERN_ERR "Internal error whilst attempting to get "
2104 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
2105 crypt_stat->cipher, rc);
2106 goto out;
Michael Halcrow237fead2006-10-04 02:16:22 -07002107 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002108 if (mount_crypt_stat->global_default_cipher_key_size == 0) {
2109 struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm);
2110
2111 printk(KERN_WARNING "No key size specified at mount; "
2112 "defaulting to [%d]\n", alg->max_keysize);
2113 mount_crypt_stat->global_default_cipher_key_size =
2114 alg->max_keysize;
2115 }
2116 if (crypt_stat->key_size == 0)
2117 crypt_stat->key_size =
2118 mount_crypt_stat->global_default_cipher_key_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07002119 if (auth_tok->session_key.encrypted_key_size == 0)
2120 auth_tok->session_key.encrypted_key_size =
2121 crypt_stat->key_size;
2122 if (crypt_stat->key_size == 24
2123 && strcmp("aes", crypt_stat->cipher) == 0) {
2124 memset((crypt_stat->key + 24), 0, 8);
2125 auth_tok->session_key.encrypted_key_size = 32;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002126 } else
2127 auth_tok->session_key.encrypted_key_size = crypt_stat->key_size;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002128 key_rec->enc_key_size =
Michael Halcrow237fead2006-10-04 02:16:22 -07002129 auth_tok->session_key.encrypted_key_size;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002130 encrypted_session_key_valid = 0;
2131 for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++)
2132 encrypted_session_key_valid |=
2133 auth_tok->session_key.encrypted_key[i];
2134 if (encrypted_session_key_valid) {
2135 ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; "
2136 "using auth_tok->session_key.encrypted_key, "
2137 "where key_rec->enc_key_size = [%d]\n",
2138 key_rec->enc_key_size);
2139 memcpy(key_rec->enc_key,
2140 auth_tok->session_key.encrypted_key,
2141 key_rec->enc_key_size);
2142 goto encrypted_session_key_set;
2143 }
Michael Halcrowdddfa462007-02-12 00:53:44 -08002144 if (auth_tok->token.password.flags &
2145 ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002146 ecryptfs_printk(KERN_DEBUG, "Using previously generated "
2147 "session key encryption key of size [%d]\n",
2148 auth_tok->token.password.
2149 session_key_encryption_key_bytes);
2150 memcpy(session_key_encryption_key,
2151 auth_tok->token.password.session_key_encryption_key,
2152 crypt_stat->key_size);
2153 ecryptfs_printk(KERN_DEBUG,
2154 "Cached session key " "encryption key: \n");
2155 if (ecryptfs_verbosity > 0)
2156 ecryptfs_dump_hex(session_key_encryption_key, 16);
2157 }
2158 if (unlikely(ecryptfs_verbosity > 0)) {
2159 ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n");
2160 ecryptfs_dump_hex(session_key_encryption_key, 16);
2161 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07002162 rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002163 src_sg, 2);
2164 if (rc < 1 || rc > 2) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002165 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
Michael Halcrowf4aad162007-10-16 01:27:53 -07002166 "for crypt_stat session key; expected rc = 1; "
2167 "got rc = [%d]. key_rec->enc_key_size = [%d]\n",
2168 rc, key_rec->enc_key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002169 rc = -ENOMEM;
2170 goto out;
2171 }
Michael Halcrow5dda6992007-10-16 01:28:06 -07002172 rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size,
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002173 dst_sg, 2);
2174 if (rc < 1 || rc > 2) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002175 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
Michael Halcrowf4aad162007-10-16 01:27:53 -07002176 "for crypt_stat encrypted session key; "
2177 "expected rc = 1; got rc = [%d]. "
2178 "key_rec->enc_key_size = [%d]\n", rc,
2179 key_rec->enc_key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002180 rc = -ENOMEM;
2181 goto out;
2182 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002183 mutex_lock(tfm_mutex);
Michael Halcrow8bba0662006-10-30 22:07:18 -08002184 rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key,
2185 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002186 if (rc < 0) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002187 mutex_unlock(tfm_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -07002188 ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
Michael Halcrow8bba0662006-10-30 22:07:18 -08002189 "context; rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002190 goto out;
2191 }
2192 rc = 0;
2193 ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n",
2194 crypt_stat->key_size);
Michael Halcrowac97b9f2008-11-19 15:36:28 -08002195 rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg,
Michael Halcrow8bba0662006-10-30 22:07:18 -08002196 (*key_rec).enc_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002197 mutex_unlock(tfm_mutex);
Michael Halcrow8bba0662006-10-30 22:07:18 -08002198 if (rc) {
2199 printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc);
2200 goto out;
2201 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002202 ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
Michael Halcrowf4aad162007-10-16 01:27:53 -07002203 if (ecryptfs_verbosity > 0) {
2204 ecryptfs_printk(KERN_DEBUG, "EFEK of size [%d]:\n",
2205 key_rec->enc_key_size);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002206 ecryptfs_dump_hex(key_rec->enc_key,
2207 key_rec->enc_key_size);
Michael Halcrowf4aad162007-10-16 01:27:53 -07002208 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002209encrypted_session_key_set:
Michael Halcrow237fead2006-10-04 02:16:22 -07002210 /* This format is inspired by OpenPGP; see RFC 2440
2211 * packet tag 3 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002212 max_packet_size = (1 /* Tag 3 identifier */
2213 + 3 /* Max Tag 3 packet size */
2214 + 1 /* Version */
2215 + 1 /* Cipher code */
2216 + 1 /* S2K specifier */
2217 + 1 /* Hash identifier */
2218 + ECRYPTFS_SALT_SIZE /* Salt */
2219 + 1 /* Hash iterations */
2220 + key_rec->enc_key_size); /* Encrypted key size */
2221 if (max_packet_size > (*remaining_bytes)) {
Andrew Morton81acbcd2007-10-16 01:27:59 -07002222 printk(KERN_ERR "Packet too large; need up to [%td] bytes, but "
2223 "there are only [%td] available\n", max_packet_size,
Michael Halcrowf4aad162007-10-16 01:27:53 -07002224 (*remaining_bytes));
2225 rc = -EINVAL;
2226 goto out;
2227 }
Michael Halcrow237fead2006-10-04 02:16:22 -07002228 dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002229 /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3)
2230 * to get the number of octets in the actual Tag 3 packet */
Michael Halcrowf66e8832008-04-29 00:59:51 -07002231 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
2232 (max_packet_size - 4),
2233 &packet_size_length);
Michael Halcrow237fead2006-10-04 02:16:22 -07002234 if (rc) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002235 printk(KERN_ERR "Error generating tag 3 packet header; cannot "
2236 "generate packet length. rc = [%d]\n", rc);
Michael Halcrow237fead2006-10-04 02:16:22 -07002237 goto out;
2238 }
2239 (*packet_size) += packet_size_length;
2240 dest[(*packet_size)++] = 0x04; /* version 4 */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002241 /* TODO: Break from RFC2440 so that arbitrary ciphers can be
2242 * specified with strings */
Michael Halcrow9c79f342009-01-06 14:41:57 -08002243 cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher,
2244 crypt_stat->key_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002245 if (cipher_code == 0) {
2246 ecryptfs_printk(KERN_WARNING, "Unable to generate code for "
2247 "cipher [%s]\n", crypt_stat->cipher);
2248 rc = -EINVAL;
2249 goto out;
2250 }
2251 dest[(*packet_size)++] = cipher_code;
2252 dest[(*packet_size)++] = 0x03; /* S2K */
2253 dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */
2254 memcpy(&dest[(*packet_size)], auth_tok->token.password.salt,
2255 ECRYPTFS_SALT_SIZE);
2256 (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */
2257 dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */
Michael Halcrowdddfa462007-02-12 00:53:44 -08002258 memcpy(&dest[(*packet_size)], key_rec->enc_key,
2259 key_rec->enc_key_size);
2260 (*packet_size) += key_rec->enc_key_size;
Michael Halcrow237fead2006-10-04 02:16:22 -07002261out:
Michael Halcrow237fead2006-10-04 02:16:22 -07002262 if (rc)
2263 (*packet_size) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002264 else
2265 (*remaining_bytes) -= (*packet_size);
Michael Halcrow237fead2006-10-04 02:16:22 -07002266 return rc;
2267}
2268
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002269struct kmem_cache *ecryptfs_key_record_cache;
2270
Michael Halcrow237fead2006-10-04 02:16:22 -07002271/**
2272 * ecryptfs_generate_key_packet_set
Michael Halcrow22e78fa2007-10-16 01:28:02 -07002273 * @dest_base: Virtual address from which to write the key record set
Michael Halcrow237fead2006-10-04 02:16:22 -07002274 * @crypt_stat: The cryptographic context from which the
2275 * authentication tokens will be retrieved
2276 * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat
2277 * for the global parameters
2278 * @len: The amount written
2279 * @max: The maximum amount of data allowed to be written
2280 *
2281 * Generates a key packet set and writes it to the virtual address
2282 * passed in.
2283 *
2284 * Returns zero on success; non-zero on error.
2285 */
2286int
2287ecryptfs_generate_key_packet_set(char *dest_base,
2288 struct ecryptfs_crypt_stat *crypt_stat,
2289 struct dentry *ecryptfs_dentry, size_t *len,
2290 size_t max)
2291{
Michael Halcrow237fead2006-10-04 02:16:22 -07002292 struct ecryptfs_auth_tok *auth_tok;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002293 struct ecryptfs_global_auth_tok *global_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07002294 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2295 &ecryptfs_superblock_to_private(
2296 ecryptfs_dentry->d_sb)->mount_crypt_stat;
2297 size_t written;
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002298 struct ecryptfs_key_record *key_rec;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002299 struct ecryptfs_key_sig *key_sig;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002300 int rc = 0;
Michael Halcrow237fead2006-10-04 02:16:22 -07002301
2302 (*len) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002303 mutex_lock(&crypt_stat->keysig_list_mutex);
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002304 key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL);
2305 if (!key_rec) {
2306 rc = -ENOMEM;
2307 goto out;
2308 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002309 list_for_each_entry(key_sig, &crypt_stat->keysig_list,
2310 crypt_stat_list) {
2311 memset(key_rec, 0, sizeof(*key_rec));
2312 rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
2313 mount_crypt_stat,
2314 key_sig->keysig);
2315 if (rc) {
2316 printk(KERN_ERR "Error attempting to get the global "
2317 "auth_tok; rc = [%d]\n", rc);
2318 goto out_free;
2319 }
2320 if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) {
2321 printk(KERN_WARNING
2322 "Skipping invalid auth tok with sig = [%s]\n",
2323 global_auth_tok->sig);
2324 continue;
2325 }
2326 auth_tok = global_auth_tok->global_auth_tok;
Michael Halcrow237fead2006-10-04 02:16:22 -07002327 if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
2328 rc = write_tag_3_packet((dest_base + (*len)),
Michael Halcrowf4aad162007-10-16 01:27:53 -07002329 &max, auth_tok,
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002330 crypt_stat, key_rec,
Michael Halcrow237fead2006-10-04 02:16:22 -07002331 &written);
2332 if (rc) {
2333 ecryptfs_printk(KERN_WARNING, "Error "
2334 "writing tag 3 packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002335 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002336 }
2337 (*len) += written;
2338 /* Write auth tok signature packet */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002339 rc = write_tag_11_packet((dest_base + (*len)), &max,
2340 key_rec->sig,
2341 ECRYPTFS_SIG_SIZE, &written);
Michael Halcrow237fead2006-10-04 02:16:22 -07002342 if (rc) {
2343 ecryptfs_printk(KERN_ERR, "Error writing "
2344 "auth tok signature packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002345 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002346 }
2347 (*len) += written;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002348 } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
2349 rc = write_tag_1_packet(dest_base + (*len),
Michael Halcrowf4aad162007-10-16 01:27:53 -07002350 &max, auth_tok,
2351 crypt_stat, key_rec, &written);
Michael Halcrowdddfa462007-02-12 00:53:44 -08002352 if (rc) {
2353 ecryptfs_printk(KERN_WARNING, "Error "
2354 "writing tag 1 packet\n");
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002355 goto out_free;
Michael Halcrowdddfa462007-02-12 00:53:44 -08002356 }
2357 (*len) += written;
Michael Halcrow237fead2006-10-04 02:16:22 -07002358 } else {
2359 ecryptfs_printk(KERN_WARNING, "Unsupported "
2360 "authentication token type\n");
2361 rc = -EINVAL;
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002362 goto out_free;
Michael Halcrow237fead2006-10-04 02:16:22 -07002363 }
Michael Halcrowf4aad162007-10-16 01:27:53 -07002364 }
2365 if (likely(max > 0)) {
Michael Halcrow237fead2006-10-04 02:16:22 -07002366 dest_base[(*len)] = 0x00;
2367 } else {
2368 ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n");
2369 rc = -EIO;
2370 }
Michael Halcroweb95e7f2007-02-16 01:28:40 -08002371out_free:
2372 kmem_cache_free(ecryptfs_key_record_cache, key_rec);
Michael Halcrow237fead2006-10-04 02:16:22 -07002373out:
2374 if (rc)
2375 (*len) = 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002376 mutex_unlock(&crypt_stat->keysig_list_mutex);
Michael Halcrow237fead2006-10-04 02:16:22 -07002377 return rc;
2378}
Michael Halcrowf4aad162007-10-16 01:27:53 -07002379
2380struct kmem_cache *ecryptfs_key_sig_cache;
2381
2382int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig)
2383{
2384 struct ecryptfs_key_sig *new_key_sig;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002385
2386 new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL);
2387 if (!new_key_sig) {
Michael Halcrowf4aad162007-10-16 01:27:53 -07002388 printk(KERN_ERR
2389 "Error allocating from ecryptfs_key_sig_cache\n");
Roland Dreieraa061172009-07-01 15:48:18 -07002390 return -ENOMEM;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002391 }
2392 memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
Roland Dreieraa061172009-07-01 15:48:18 -07002393 /* Caller must hold keysig_list_mutex */
Michael Halcrowf4aad162007-10-16 01:27:53 -07002394 list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
Roland Dreieraa061172009-07-01 15:48:18 -07002395
2396 return 0;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002397}
2398
2399struct kmem_cache *ecryptfs_global_auth_tok_cache;
2400
2401int
2402ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
Tyler Hicks84814d62009-03-13 13:51:59 -07002403 char *sig, u32 global_auth_tok_flags)
Michael Halcrowf4aad162007-10-16 01:27:53 -07002404{
2405 struct ecryptfs_global_auth_tok *new_auth_tok;
2406 int rc = 0;
2407
Eric Sandeen459e2162007-12-17 16:19:52 -08002408 new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache,
Michael Halcrowf4aad162007-10-16 01:27:53 -07002409 GFP_KERNEL);
2410 if (!new_auth_tok) {
2411 rc = -ENOMEM;
2412 printk(KERN_ERR "Error allocating from "
2413 "ecryptfs_global_auth_tok_cache\n");
2414 goto out;
2415 }
2416 memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX);
Tyler Hicks84814d62009-03-13 13:51:59 -07002417 new_auth_tok->flags = global_auth_tok_flags;
Michael Halcrowf4aad162007-10-16 01:27:53 -07002418 new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
2419 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
2420 list_add(&new_auth_tok->mount_crypt_stat_list,
2421 &mount_crypt_stat->global_auth_tok_list);
2422 mount_crypt_stat->num_global_auth_toks++;
2423 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
2424out:
2425 return rc;
2426}
2427