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ocfs2: ocfs2_write_begin_nolock() should handle len=0
[linux-2.6/mini2440.git] / fs / ecryptfs / keystore.c
blobaf737bb56cb71942ebed99c9bad8eb6a34bdaeb8
1 /**
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>
10 * Trevor S. Highland <trevor.highland@gmail.com>
11 *
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>
29 #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 */
42 static int process_request_key_err(long err_code)
43 {
44 int rc = 0;
45
46 switch (err_code) {
47 case -ENOKEY:
48 ecryptfs_printk(KERN_WARNING, "No key\n");
49 rc = -ENOENT;
50 break;
51 case -EKEYEXPIRED:
52 ecryptfs_printk(KERN_WARNING, "Key expired\n");
53 rc = -ETIME;
54 break;
55 case -EKEYREVOKED:
56 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
67 /**
68 * ecryptfs_parse_packet_length
69 * @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 *
74 * Returns zero on success; non-zero on error
75 */
76 int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
77 size_t *length_size)
78 {
79 int rc = 0;
80
81 (*length_size) = 0;
82 (*size) = 0;
83 if (data[0] < 192) {
84 /* One-byte length */
85 (*size) = (unsigned char)data[0];
86 (*length_size) = 1;
87 } else if (data[0] < 224) {
88 /* Two-byte length */
89 (*size) = (((unsigned char)(data[0]) - 192) * 256);
90 (*size) += ((unsigned char)(data[1]) + 192);
91 (*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 }
103 out:
104 return rc;
105 }
106
107 /**
108 * ecryptfs_write_packet_length
109 * @dest: The byte array target into which to write the length. Must
110 * have at least 5 bytes allocated.
111 * @size: The length to write.
112 * @packet_size_length: The number of bytes used to encode the packet
113 * length is written to this address.
114 *
115 * Returns zero on success; non-zero on error.
116 */
117 int ecryptfs_write_packet_length(char *dest, size_t size,
118 size_t *packet_size_length)
119 {
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
137 static int
138 write_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;
165 rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
166 &packet_size_len);
167 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;
175 rc = ecryptfs_write_packet_length(&message[i],
176 session_key->encrypted_key_size,
177 &packet_size_len);
178 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;
188 out:
189 return rc;
190 }
191
192 static int
193 parse_tag_65_packet(struct ecryptfs_session_key *session_key, u8 *cipher_code,
194 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 }
229 rc = ecryptfs_parse_packet_length(&data[i], &m_size, &data_len);
230 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)) {
237 ecryptfs_printk(KERN_ERR, "The message received from ecryptfsd "
238 "is shorter than expected\n");
239 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 }
273 out:
274 return rc;
275 }
276
277
278 static int
279 write_tag_66_packet(char *signature, u8 cipher_code,
280 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;
308 rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
309 &packet_size_len);
310 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 */
319 rc = ecryptfs_write_packet_length(&message[i], crypt_stat->key_size + 3,
320 &packet_size_len);
321 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;
335 out:
336 return rc;
337 }
338
339 static int
340 parse_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;
361 printk(KERN_ERR "%s: message_len is [%zd]; minimum acceptable "
362 "message length is [%d]\n", __func__, message_len, 4);
363 goto out;
364 }
365 if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) {
366 rc = -EIO;
367 printk(KERN_ERR "%s: Type should be ECRYPTFS_TAG_67\n",
368 __func__);
369 goto out;
370 }
371 if (data[i++]) {
372 rc = -EIO;
373 printk(KERN_ERR "%s: Status indicator has non zero "
374 "value [%d]\n", __func__, data[i-1]);
375
376 goto out;
377 }
378 rc = ecryptfs_parse_packet_length(&data[i], &key_rec->enc_key_size,
379 &data_len);
380 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)) {
387 rc = -EIO;
388 printk(KERN_ERR "%s: message_len [%zd]; max len is [%zd]\n",
389 __func__, message_len, (i + key_rec->enc_key_size));
390 goto out;
391 }
392 if (key_rec->enc_key_size > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
393 rc = -EIO;
394 printk(KERN_ERR "%s: Encrypted key_size [%zd] larger than "
395 "the maximum key size [%d]\n", __func__,
396 key_rec->enc_key_size,
397 ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES);
398 goto out;
399 }
400 memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size);
401 out:
402 return rc;
403 }
404
405 static int
406 ecryptfs_find_global_auth_tok_for_sig(
407 struct ecryptfs_global_auth_tok **global_auth_tok,
408 struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig)
409 {
410 struct ecryptfs_global_auth_tok *walker;
411 int rc = 0;
412
413 (*global_auth_tok) = NULL;
414 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
415 list_for_each_entry(walker,
416 &mount_crypt_stat->global_auth_tok_list,
417 mount_crypt_stat_list) {
418 if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX) == 0) {
419 (*global_auth_tok) = walker;
420 goto out;
421 }
422 }
423 rc = -EINVAL;
424 out:
425 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
426 return rc;
427 }
428
429 /**
430 * ecryptfs_find_auth_tok_for_sig
431 * @auth_tok: Set to the matching auth_tok; NULL if not found
432 * @crypt_stat: inode crypt_stat crypto context
433 * @sig: Sig of auth_tok to find
434 *
435 * For now, this function simply looks at the registered auth_tok's
436 * linked off the mount_crypt_stat, so all the auth_toks that can be
437 * used must be registered at mount time. This function could
438 * potentially try a lot harder to find auth_tok's (e.g., by calling
439 * out to ecryptfsd to dynamically retrieve an auth_tok object) so
440 * that static registration of auth_tok's will no longer be necessary.
441 *
442 * Returns zero on no error; non-zero on error
443 */
444 static int
445 ecryptfs_find_auth_tok_for_sig(
446 struct ecryptfs_auth_tok **auth_tok,
447 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
448 char *sig)
449 {
450 struct ecryptfs_global_auth_tok *global_auth_tok;
451 int rc = 0;
452
453 (*auth_tok) = NULL;
454 if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
455 mount_crypt_stat, sig)) {
456 struct key *auth_tok_key;
457
458 rc = ecryptfs_keyring_auth_tok_for_sig(&auth_tok_key, auth_tok,
459 sig);
460 } else
461 (*auth_tok) = global_auth_tok->global_auth_tok;
462 return rc;
463 }
464
465 /**
466 * write_tag_70_packet can gobble a lot of stack space. We stuff most
467 * of the function's parameters in a kmalloc'd struct to help reduce
468 * eCryptfs' overall stack usage.
469 */
470 struct ecryptfs_write_tag_70_packet_silly_stack {
471 u8 cipher_code;
472 size_t max_packet_size;
473 size_t packet_size_len;
474 size_t block_aligned_filename_size;
475 size_t block_size;
476 size_t i;
477 size_t j;
478 size_t num_rand_bytes;
479 struct mutex *tfm_mutex;
480 char *block_aligned_filename;
481 struct ecryptfs_auth_tok *auth_tok;
482 struct scatterlist src_sg;
483 struct scatterlist dst_sg;
484 struct blkcipher_desc desc;
485 char iv[ECRYPTFS_MAX_IV_BYTES];
486 char hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
487 char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE];
488 struct hash_desc hash_desc;
489 struct scatterlist hash_sg;
490 };
491
492 /**
493 * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK
494 * @filename: NULL-terminated filename string
495 *
496 * This is the simplest mechanism for achieving filename encryption in
497 * eCryptfs. It encrypts the given filename with the mount-wide
498 * filename encryption key (FNEK) and stores it in a packet to @dest,
499 * which the callee will encode and write directly into the dentry
500 * name.
501 */
502 int
503 ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
504 size_t *packet_size,
505 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
506 char *filename, size_t filename_size)
507 {
508 struct ecryptfs_write_tag_70_packet_silly_stack *s;
509 int rc = 0;
510
511 s = kmalloc(sizeof(*s), GFP_KERNEL);
512 if (!s) {
513 printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
514 "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
515 goto out;
516 }
517 s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
518 (*packet_size) = 0;
519 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(
520 &s->desc.tfm,
521 &s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name);
522 if (unlikely(rc)) {
523 printk(KERN_ERR "Internal error whilst attempting to get "
524 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
525 mount_crypt_stat->global_default_fn_cipher_name, rc);
526 goto out;
527 }
528 mutex_lock(s->tfm_mutex);
529 s->block_size = crypto_blkcipher_blocksize(s->desc.tfm);
530 /* Plus one for the \0 separator between the random prefix
531 * and the plaintext filename */
532 s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1);
533 s->block_aligned_filename_size = (s->num_rand_bytes + filename_size);
534 if ((s->block_aligned_filename_size % s->block_size) != 0) {
535 s->num_rand_bytes += (s->block_size
536 - (s->block_aligned_filename_size
537 % s->block_size));
538 s->block_aligned_filename_size = (s->num_rand_bytes
539 + filename_size);
540 }
541 /* Octet 0: Tag 70 identifier
542 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
543 * and block-aligned encrypted filename size)
544 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
545 * Octet N2-N3: Cipher identifier (1 octet)
546 * Octets N3-N4: Block-aligned encrypted filename
547 * - Consists of a minimum number of random characters, a \0
548 * separator, and then the filename */
549 s->max_packet_size = (1 /* Tag 70 identifier */
550 + 3 /* Max Tag 70 packet size */
551 + ECRYPTFS_SIG_SIZE /* FNEK sig */
552 + 1 /* Cipher identifier */
553 + s->block_aligned_filename_size);
554 if (dest == NULL) {
555 (*packet_size) = s->max_packet_size;
556 goto out_unlock;
557 }
558 if (s->max_packet_size > (*remaining_bytes)) {
559 printk(KERN_WARNING "%s: Require [%zd] bytes to write; only "
560 "[%zd] available\n", __func__, s->max_packet_size,
561 (*remaining_bytes));
562 rc = -EINVAL;
563 goto out_unlock;
564 }
565 s->block_aligned_filename = kzalloc(s->block_aligned_filename_size,
566 GFP_KERNEL);
567 if (!s->block_aligned_filename) {
568 printk(KERN_ERR "%s: Out of kernel memory whilst attempting to "
569 "kzalloc [%zd] bytes\n", __func__,
570 s->block_aligned_filename_size);
571 rc = -ENOMEM;
572 goto out_unlock;
573 }
574 s->i = 0;
575 dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE;
576 rc = ecryptfs_write_packet_length(&dest[s->i],
577 (ECRYPTFS_SIG_SIZE
578 + 1 /* Cipher code */
579 + s->block_aligned_filename_size),
580 &s->packet_size_len);
581 if (rc) {
582 printk(KERN_ERR "%s: Error generating tag 70 packet "
583 "header; cannot generate packet length; rc = [%d]\n",
584 __func__, rc);
585 goto out_free_unlock;
586 }
587 s->i += s->packet_size_len;
588 ecryptfs_from_hex(&dest[s->i],
589 mount_crypt_stat->global_default_fnek_sig,
590 ECRYPTFS_SIG_SIZE);
591 s->i += ECRYPTFS_SIG_SIZE;
592 s->cipher_code = ecryptfs_code_for_cipher_string(
593 mount_crypt_stat->global_default_fn_cipher_name,
594 mount_crypt_stat->global_default_fn_cipher_key_bytes);
595 if (s->cipher_code == 0) {
596 printk(KERN_WARNING "%s: Unable to generate code for "
597 "cipher [%s] with key bytes [%zd]\n", __func__,
598 mount_crypt_stat->global_default_fn_cipher_name,
599 mount_crypt_stat->global_default_fn_cipher_key_bytes);
600 rc = -EINVAL;
601 goto out_free_unlock;
602 }
603 dest[s->i++] = s->cipher_code;
604 rc = ecryptfs_find_auth_tok_for_sig(
605 &s->auth_tok, mount_crypt_stat,
606 mount_crypt_stat->global_default_fnek_sig);
607 if (rc) {
608 printk(KERN_ERR "%s: Error attempting to find auth tok for "
609 "fnek sig [%s]; rc = [%d]\n", __func__,
610 mount_crypt_stat->global_default_fnek_sig, rc);
611 goto out_free_unlock;
612 }
613 /* TODO: Support other key modules than passphrase for
614 * filename encryption */
615 BUG_ON(s->auth_tok->token_type != ECRYPTFS_PASSWORD);
616 sg_init_one(
617 &s->hash_sg,
618 (u8 *)s->auth_tok->token.password.session_key_encryption_key,
619 s->auth_tok->token.password.session_key_encryption_key_bytes);
620 s->hash_desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
621 s->hash_desc.tfm = crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST, 0,
622 CRYPTO_ALG_ASYNC);
623 if (IS_ERR(s->hash_desc.tfm)) {
624 rc = PTR_ERR(s->hash_desc.tfm);
625 printk(KERN_ERR "%s: Error attempting to "
626 "allocate hash crypto context; rc = [%d]\n",
627 __func__, rc);
628 goto out_free_unlock;
629 }
630 rc = crypto_hash_init(&s->hash_desc);
631 if (rc) {
632 printk(KERN_ERR
633 "%s: Error initializing crypto hash; rc = [%d]\n",
634 __func__, rc);
635 goto out_release_free_unlock;
636 }
637 rc = crypto_hash_update(
638 &s->hash_desc, &s->hash_sg,
639 s->auth_tok->token.password.session_key_encryption_key_bytes);
640 if (rc) {
641 printk(KERN_ERR
642 "%s: Error updating crypto hash; rc = [%d]\n",
643 __func__, rc);
644 goto out_release_free_unlock;
645 }
646 rc = crypto_hash_final(&s->hash_desc, s->hash);
647 if (rc) {
648 printk(KERN_ERR
649 "%s: Error finalizing crypto hash; rc = [%d]\n",
650 __func__, rc);
651 goto out_release_free_unlock;
652 }
653 for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) {
654 s->block_aligned_filename[s->j] =
655 s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)];
656 if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)
657 == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) {
658 sg_init_one(&s->hash_sg, (u8 *)s->hash,
659 ECRYPTFS_TAG_70_DIGEST_SIZE);
660 rc = crypto_hash_init(&s->hash_desc);
661 if (rc) {
662 printk(KERN_ERR
663 "%s: Error initializing crypto hash; "
664 "rc = [%d]\n", __func__, rc);
665 goto out_release_free_unlock;
666 }
667 rc = crypto_hash_update(&s->hash_desc, &s->hash_sg,
668 ECRYPTFS_TAG_70_DIGEST_SIZE);
669 if (rc) {
670 printk(KERN_ERR
671 "%s: Error updating crypto hash; "
672 "rc = [%d]\n", __func__, rc);
673 goto out_release_free_unlock;
674 }
675 rc = crypto_hash_final(&s->hash_desc, s->tmp_hash);
676 if (rc) {
677 printk(KERN_ERR
678 "%s: Error finalizing crypto hash; "
679 "rc = [%d]\n", __func__, rc);
680 goto out_release_free_unlock;
681 }
682 memcpy(s->hash, s->tmp_hash,
683 ECRYPTFS_TAG_70_DIGEST_SIZE);
684 }
685 if (s->block_aligned_filename[s->j] == '\0')
686 s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL;
687 }
688 memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename,
689 filename_size);
690 rc = virt_to_scatterlist(s->block_aligned_filename,
691 s->block_aligned_filename_size, &s->src_sg, 1);
692 if (rc != 1) {
693 printk(KERN_ERR "%s: Internal error whilst attempting to "
694 "convert filename memory to scatterlist; "
695 "expected rc = 1; got rc = [%d]. "
696 "block_aligned_filename_size = [%zd]\n", __func__, rc,
697 s->block_aligned_filename_size);
698 goto out_release_free_unlock;
699 }
700 rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size,
701 &s->dst_sg, 1);
702 if (rc != 1) {
703 printk(KERN_ERR "%s: Internal error whilst attempting to "
704 "convert encrypted filename memory to scatterlist; "
705 "expected rc = 1; got rc = [%d]. "
706 "block_aligned_filename_size = [%zd]\n", __func__, rc,
707 s->block_aligned_filename_size);
708 goto out_release_free_unlock;
709 }
710 /* The characters in the first block effectively do the job
711 * of the IV here, so we just use 0's for the IV. Note the
712 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
713 * >= ECRYPTFS_MAX_IV_BYTES. */
714 memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
715 s->desc.info = s->iv;
716 rc = crypto_blkcipher_setkey(
717 s->desc.tfm,
718 s->auth_tok->token.password.session_key_encryption_key,
719 mount_crypt_stat->global_default_fn_cipher_key_bytes);
720 if (rc < 0) {
721 printk(KERN_ERR "%s: Error setting key for crypto context; "
722 "rc = [%d]. s->auth_tok->token.password.session_key_"
723 "encryption_key = [0x%p]; mount_crypt_stat->"
724 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
725 rc,
726 s->auth_tok->token.password.session_key_encryption_key,
727 mount_crypt_stat->global_default_fn_cipher_key_bytes);
728 goto out_release_free_unlock;
729 }
730 rc = crypto_blkcipher_encrypt_iv(&s->desc, &s->dst_sg, &s->src_sg,
731 s->block_aligned_filename_size);
732 if (rc) {
733 printk(KERN_ERR "%s: Error attempting to encrypt filename; "
734 "rc = [%d]\n", __func__, rc);
735 goto out_release_free_unlock;
736 }
737 s->i += s->block_aligned_filename_size;
738 (*packet_size) = s->i;
739 (*remaining_bytes) -= (*packet_size);
740 out_release_free_unlock:
741 crypto_free_hash(s->hash_desc.tfm);
742 out_free_unlock:
743 kzfree(s->block_aligned_filename);
744 out_unlock:
745 mutex_unlock(s->tfm_mutex);
746 out:
747 kfree(s);
748 return rc;
749 }
750
751 struct ecryptfs_parse_tag_70_packet_silly_stack {
752 u8 cipher_code;
753 size_t max_packet_size;
754 size_t packet_size_len;
755 size_t parsed_tag_70_packet_size;
756 size_t block_aligned_filename_size;
757 size_t block_size;
758 size_t i;
759 struct mutex *tfm_mutex;
760 char *decrypted_filename;
761 struct ecryptfs_auth_tok *auth_tok;
762 struct scatterlist src_sg;
763 struct scatterlist dst_sg;
764 struct blkcipher_desc desc;
765 char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1];
766 char iv[ECRYPTFS_MAX_IV_BYTES];
767 char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE];
768 };
769
770 /**
771 * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet
772 * @filename: This function kmalloc's the memory for the filename
773 * @filename_size: This function sets this to the amount of memory
774 * kmalloc'd for the filename
775 * @packet_size: This function sets this to the the number of octets
776 * in the packet parsed
777 * @mount_crypt_stat: The mount-wide cryptographic context
778 * @data: The memory location containing the start of the tag 70
779 * packet
780 * @max_packet_size: The maximum legal size of the packet to be parsed
781 * from @data
782 *
783 * Returns zero on success; non-zero otherwise
784 */
785 int
786 ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
787 size_t *packet_size,
788 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
789 char *data, size_t max_packet_size)
790 {
791 struct ecryptfs_parse_tag_70_packet_silly_stack *s;
792 int rc = 0;
793
794 (*packet_size) = 0;
795 (*filename_size) = 0;
796 (*filename) = NULL;
797 s = kmalloc(sizeof(*s), GFP_KERNEL);
798 if (!s) {
799 printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
800 "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
801 goto out;
802 }
803 s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
804 if (max_packet_size < (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)) {
805 printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be "
806 "at least [%d]\n", __func__, max_packet_size,
807 (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1));
808 rc = -EINVAL;
809 goto out;
810 }
811 /* Octet 0: Tag 70 identifier
812 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
813 * and block-aligned encrypted filename size)
814 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
815 * Octet N2-N3: Cipher identifier (1 octet)
816 * Octets N3-N4: Block-aligned encrypted filename
817 * - Consists of a minimum number of random numbers, a \0
818 * separator, and then the filename */
819 if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) {
820 printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be "
821 "tag [0x%.2x]\n", __func__,
822 data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE);
823 rc = -EINVAL;
824 goto out;
825 }
826 rc = ecryptfs_parse_packet_length(&data[(*packet_size)],
827 &s->parsed_tag_70_packet_size,
828 &s->packet_size_len);
829 if (rc) {
830 printk(KERN_WARNING "%s: Error parsing packet length; "
831 "rc = [%d]\n", __func__, rc);
832 goto out;
833 }
834 s->block_aligned_filename_size = (s->parsed_tag_70_packet_size
835 - ECRYPTFS_SIG_SIZE - 1);
836 if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size)
837 > max_packet_size) {
838 printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet "
839 "size is [%zd]\n", __func__, max_packet_size,
840 (1 + s->packet_size_len + 1
841 + s->block_aligned_filename_size));
842 rc = -EINVAL;
843 goto out;
844 }
845 (*packet_size) += s->packet_size_len;
846 ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)],
847 ECRYPTFS_SIG_SIZE);
848 s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0';
849 (*packet_size) += ECRYPTFS_SIG_SIZE;
850 s->cipher_code = data[(*packet_size)++];
851 rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code);
852 if (rc) {
853 printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n",
854 __func__, s->cipher_code);
855 goto out;
856 }
857 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm,
858 &s->tfm_mutex,
859 s->cipher_string);
860 if (unlikely(rc)) {
861 printk(KERN_ERR "Internal error whilst attempting to get "
862 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
863 s->cipher_string, rc);
864 goto out;
865 }
866 mutex_lock(s->tfm_mutex);
867 rc = virt_to_scatterlist(&data[(*packet_size)],
868 s->block_aligned_filename_size, &s->src_sg, 1);
869 if (rc != 1) {
870 printk(KERN_ERR "%s: Internal error whilst attempting to "
871 "convert encrypted filename memory to scatterlist; "
872 "expected rc = 1; got rc = [%d]. "
873 "block_aligned_filename_size = [%zd]\n", __func__, rc,
874 s->block_aligned_filename_size);
875 goto out_unlock;
876 }
877 (*packet_size) += s->block_aligned_filename_size;
878 s->decrypted_filename = kmalloc(s->block_aligned_filename_size,
879 GFP_KERNEL);
880 if (!s->decrypted_filename) {
881 printk(KERN_ERR "%s: Out of memory whilst attempting to "
882 "kmalloc [%zd] bytes\n", __func__,
883 s->block_aligned_filename_size);
884 rc = -ENOMEM;
885 goto out_unlock;
886 }
887 rc = virt_to_scatterlist(s->decrypted_filename,
888 s->block_aligned_filename_size, &s->dst_sg, 1);
889 if (rc != 1) {
890 printk(KERN_ERR "%s: Internal error whilst attempting to "
891 "convert decrypted filename memory to scatterlist; "
892 "expected rc = 1; got rc = [%d]. "
893 "block_aligned_filename_size = [%zd]\n", __func__, rc,
894 s->block_aligned_filename_size);
895 goto out_free_unlock;
896 }
897 /* The characters in the first block effectively do the job of
898 * the IV here, so we just use 0's for the IV. Note the
899 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
900 * >= ECRYPTFS_MAX_IV_BYTES. */
901 memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
902 s->desc.info = s->iv;
903 rc = ecryptfs_find_auth_tok_for_sig(&s->auth_tok, mount_crypt_stat,
904 s->fnek_sig_hex);
905 if (rc) {
906 printk(KERN_ERR "%s: Error attempting to find auth tok for "
907 "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex,
908 rc);
909 goto out_free_unlock;
910 }
911 /* TODO: Support other key modules than passphrase for
912 * filename encryption */
913 BUG_ON(s->auth_tok->token_type != ECRYPTFS_PASSWORD);
914 rc = crypto_blkcipher_setkey(
915 s->desc.tfm,
916 s->auth_tok->token.password.session_key_encryption_key,
917 mount_crypt_stat->global_default_fn_cipher_key_bytes);
918 if (rc < 0) {
919 printk(KERN_ERR "%s: Error setting key for crypto context; "
920 "rc = [%d]. s->auth_tok->token.password.session_key_"
921 "encryption_key = [0x%p]; mount_crypt_stat->"
922 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
923 rc,
924 s->auth_tok->token.password.session_key_encryption_key,
925 mount_crypt_stat->global_default_fn_cipher_key_bytes);
926 goto out_free_unlock;
927 }
928 rc = crypto_blkcipher_decrypt_iv(&s->desc, &s->dst_sg, &s->src_sg,
929 s->block_aligned_filename_size);
930 if (rc) {
931 printk(KERN_ERR "%s: Error attempting to decrypt filename; "
932 "rc = [%d]\n", __func__, rc);
933 goto out_free_unlock;
934 }
935 s->i = 0;
936 while (s->decrypted_filename[s->i] != '\0'
937 && s->i < s->block_aligned_filename_size)
938 s->i++;
939 if (s->i == s->block_aligned_filename_size) {
940 printk(KERN_WARNING "%s: Invalid tag 70 packet; could not "
941 "find valid separator between random characters and "
942 "the filename\n", __func__);
943 rc = -EINVAL;
944 goto out_free_unlock;
945 }
946 s->i++;
947 (*filename_size) = (s->block_aligned_filename_size - s->i);
948 if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) {
949 printk(KERN_WARNING "%s: Filename size is [%zd], which is "
950 "invalid\n", __func__, (*filename_size));
951 rc = -EINVAL;
952 goto out_free_unlock;
953 }
954 (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL);
955 if (!(*filename)) {
956 printk(KERN_ERR "%s: Out of memory whilst attempting to "
957 "kmalloc [%zd] bytes\n", __func__,
958 ((*filename_size) + 1));
959 rc = -ENOMEM;
960 goto out_free_unlock;
961 }
962 memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size));
963 (*filename)[(*filename_size)] = '\0';
964 out_free_unlock:
965 kfree(s->decrypted_filename);
966 out_unlock:
967 mutex_unlock(s->tfm_mutex);
968 out:
969 if (rc) {
970 (*packet_size) = 0;
971 (*filename_size) = 0;
972 (*filename) = NULL;
973 }
974 kfree(s);
975 return rc;
976 }
977
978 static int
979 ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok)
980 {
981 int rc = 0;
982
983 (*sig) = NULL;
984 switch (auth_tok->token_type) {
985 case ECRYPTFS_PASSWORD:
986 (*sig) = auth_tok->token.password.signature;
987 break;
988 case ECRYPTFS_PRIVATE_KEY:
989 (*sig) = auth_tok->token.private_key.signature;
990 break;
991 default:
992 printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n",
993 auth_tok->token_type);
994 rc = -EINVAL;
995 }
996 return rc;
997 }
998
999 /**
1000 * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok.
1001 * @auth_tok: The key authentication token used to decrypt the session key
1002 * @crypt_stat: The cryptographic context
1003 *
1004 * Returns zero on success; non-zero error otherwise.
1005 */
1006 static int
1007 decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1008 struct ecryptfs_crypt_stat *crypt_stat)
1009 {
1010 u8 cipher_code = 0;
1011 struct ecryptfs_msg_ctx *msg_ctx;
1012 struct ecryptfs_message *msg = NULL;
1013 char *auth_tok_sig;
1014 char *payload;
1015 size_t payload_len;
1016 int rc;
1017
1018 rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok);
1019 if (rc) {
1020 printk(KERN_ERR "Unrecognized auth tok type: [%d]\n",
1021 auth_tok->token_type);
1022 goto out;
1023 }
1024 rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key),
1025 &payload, &payload_len);
1026 if (rc) {
1027 ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n");
1028 goto out;
1029 }
1030 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
1031 if (rc) {
1032 ecryptfs_printk(KERN_ERR, "Error sending message to "
1033 "ecryptfsd\n");
1034 goto out;
1035 }
1036 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1037 if (rc) {
1038 ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet "
1039 "from the user space daemon\n");
1040 rc = -EIO;
1041 goto out;
1042 }
1043 rc = parse_tag_65_packet(&(auth_tok->session_key),
1044 &cipher_code, msg);
1045 if (rc) {
1046 printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n",
1047 rc);
1048 goto out;
1049 }
1050 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1051 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1052 auth_tok->session_key.decrypted_key_size);
1053 crypt_stat->key_size = auth_tok->session_key.decrypted_key_size;
1054 rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code);
1055 if (rc) {
1056 ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n",
1057 cipher_code)
1058 goto out;
1059 }
1060 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1061 if (ecryptfs_verbosity > 0) {
1062 ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n");
1063 ecryptfs_dump_hex(crypt_stat->key,
1064 crypt_stat->key_size);
1065 }
1066 out:
1067 if (msg)
1068 kfree(msg);
1069 return rc;
1070 }
1071
1072 static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
1073 {
1074 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1075 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1076
1077 list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp,
1078 auth_tok_list_head, list) {
1079 list_del(&auth_tok_list_item->list);
1080 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1081 auth_tok_list_item);
1082 }
1083 }
1084
1085 struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
1086
1087 /**
1088 * parse_tag_1_packet
1089 * @crypt_stat: The cryptographic context to modify based on packet contents
1090 * @data: The raw bytes of the packet.
1091 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
1092 * a new authentication token will be placed at the
1093 * end of this list for this packet.
1094 * @new_auth_tok: Pointer to a pointer to memory that this function
1095 * allocates; sets the memory address of the pointer to
1096 * NULL on error. This object is added to the
1097 * auth_tok_list.
1098 * @packet_size: This function writes the size of the parsed packet
1099 * into this memory location; zero on error.
1100 * @max_packet_size: The maximum allowable packet size
1101 *
1102 * Returns zero on success; non-zero on error.
1103 */
1104 static int
1105 parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
1106 unsigned char *data, struct list_head *auth_tok_list,
1107 struct ecryptfs_auth_tok **new_auth_tok,
1108 size_t *packet_size, size_t max_packet_size)
1109 {
1110 size_t body_size;
1111 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1112 size_t length_size;
1113 int rc = 0;
1114
1115 (*packet_size) = 0;
1116 (*new_auth_tok) = NULL;
1117 /**
1118 * This format is inspired by OpenPGP; see RFC 2440
1119 * packet tag 1
1120 *
1121 * Tag 1 identifier (1 byte)
1122 * Max Tag 1 packet size (max 3 bytes)
1123 * Version (1 byte)
1124 * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE)
1125 * Cipher identifier (1 byte)
1126 * Encrypted key size (arbitrary)
1127 *
1128 * 12 bytes minimum packet size
1129 */
1130 if (unlikely(max_packet_size < 12)) {
1131 printk(KERN_ERR "Invalid max packet size; must be >=12\n");
1132 rc = -EINVAL;
1133 goto out;
1134 }
1135 if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) {
1136 printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n",
1137 ECRYPTFS_TAG_1_PACKET_TYPE);
1138 rc = -EINVAL;
1139 goto out;
1140 }
1141 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1142 * at end of function upon failure */
1143 auth_tok_list_item =
1144 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache,
1145 GFP_KERNEL);
1146 if (!auth_tok_list_item) {
1147 printk(KERN_ERR "Unable to allocate memory\n");
1148 rc = -ENOMEM;
1149 goto out;
1150 }
1151 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
1152 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1153 &length_size);
1154 if (rc) {
1155 printk(KERN_WARNING "Error parsing packet length; "
1156 "rc = [%d]\n", rc);
1157 goto out_free;
1158 }
1159 if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) {
1160 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
1161 rc = -EINVAL;
1162 goto out_free;
1163 }
1164 (*packet_size) += length_size;
1165 if (unlikely((*packet_size) + body_size > max_packet_size)) {
1166 printk(KERN_WARNING "Packet size exceeds max\n");
1167 rc = -EINVAL;
1168 goto out_free;
1169 }
1170 if (unlikely(data[(*packet_size)++] != 0x03)) {
1171 printk(KERN_WARNING "Unknown version number [%d]\n",
1172 data[(*packet_size) - 1]);
1173 rc = -EINVAL;
1174 goto out_free;
1175 }
1176 ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
1177 &data[(*packet_size)], ECRYPTFS_SIG_SIZE);
1178 *packet_size += ECRYPTFS_SIG_SIZE;
1179 /* This byte is skipped because the kernel does not need to
1180 * know which public key encryption algorithm was used */
1181 (*packet_size)++;
1182 (*new_auth_tok)->session_key.encrypted_key_size =
1183 body_size - (ECRYPTFS_SIG_SIZE + 2);
1184 if ((*new_auth_tok)->session_key.encrypted_key_size
1185 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
1186 printk(KERN_WARNING "Tag 1 packet contains key larger "
1187 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
1188 rc = -EINVAL;
1189 goto out;
1190 }
1191 memcpy((*new_auth_tok)->session_key.encrypted_key,
1192 &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2)));
1193 (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size;
1194 (*new_auth_tok)->session_key.flags &=
1195 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1196 (*new_auth_tok)->session_key.flags |=
1197 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
1198 (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY;
1199 (*new_auth_tok)->flags = 0;
1200 (*new_auth_tok)->session_key.flags &=
1201 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1202 (*new_auth_tok)->session_key.flags &=
1203 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
1204 list_add(&auth_tok_list_item->list, auth_tok_list);
1205 goto out;
1206 out_free:
1207 (*new_auth_tok) = NULL;
1208 memset(auth_tok_list_item, 0,
1209 sizeof(struct ecryptfs_auth_tok_list_item));
1210 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1211 auth_tok_list_item);
1212 out:
1213 if (rc)
1214 (*packet_size) = 0;
1215 return rc;
1216 }
1217
1218 /**
1219 * parse_tag_3_packet
1220 * @crypt_stat: The cryptographic context to modify based on packet
1221 * contents.
1222 * @data: The raw bytes of the packet.
1223 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
1224 * a new authentication token will be placed at the end
1225 * of this list for this packet.
1226 * @new_auth_tok: Pointer to a pointer to memory that this function
1227 * allocates; sets the memory address of the pointer to
1228 * NULL on error. This object is added to the
1229 * auth_tok_list.
1230 * @packet_size: This function writes the size of the parsed packet
1231 * into this memory location; zero on error.
1232 * @max_packet_size: maximum number of bytes to parse
1233 *
1234 * Returns zero on success; non-zero on error.
1235 */
1236 static int
1237 parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
1238 unsigned char *data, struct list_head *auth_tok_list,
1239 struct ecryptfs_auth_tok **new_auth_tok,
1240 size_t *packet_size, size_t max_packet_size)
1241 {
1242 size_t body_size;
1243 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1244 size_t length_size;
1245 int rc = 0;
1246
1247 (*packet_size) = 0;
1248 (*new_auth_tok) = NULL;
1249 /**
1250 *This format is inspired by OpenPGP; see RFC 2440
1251 * packet tag 3
1252 *
1253 * Tag 3 identifier (1 byte)
1254 * Max Tag 3 packet size (max 3 bytes)
1255 * Version (1 byte)
1256 * Cipher code (1 byte)
1257 * S2K specifier (1 byte)
1258 * Hash identifier (1 byte)
1259 * Salt (ECRYPTFS_SALT_SIZE)
1260 * Hash iterations (1 byte)
1261 * Encrypted key (arbitrary)
1262 *
1263 * (ECRYPTFS_SALT_SIZE + 7) minimum packet size
1264 */
1265 if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) {
1266 printk(KERN_ERR "Max packet size too large\n");
1267 rc = -EINVAL;
1268 goto out;
1269 }
1270 if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) {
1271 printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n",
1272 ECRYPTFS_TAG_3_PACKET_TYPE);
1273 rc = -EINVAL;
1274 goto out;
1275 }
1276 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1277 * at end of function upon failure */
1278 auth_tok_list_item =
1279 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
1280 if (!auth_tok_list_item) {
1281 printk(KERN_ERR "Unable to allocate memory\n");
1282 rc = -ENOMEM;
1283 goto out;
1284 }
1285 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
1286 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1287 &length_size);
1288 if (rc) {
1289 printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n",
1290 rc);
1291 goto out_free;
1292 }
1293 if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) {
1294 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
1295 rc = -EINVAL;
1296 goto out_free;
1297 }
1298 (*packet_size) += length_size;
1299 if (unlikely((*packet_size) + body_size > max_packet_size)) {
1300 printk(KERN_ERR "Packet size exceeds max\n");
1301 rc = -EINVAL;
1302 goto out_free;
1303 }
1304 (*new_auth_tok)->session_key.encrypted_key_size =
1305 (body_size - (ECRYPTFS_SALT_SIZE + 5));
1306 if (unlikely(data[(*packet_size)++] != 0x04)) {
1307 printk(KERN_WARNING "Unknown version number [%d]\n",
1308 data[(*packet_size) - 1]);
1309 rc = -EINVAL;
1310 goto out_free;
1311 }
1312 ecryptfs_cipher_code_to_string(crypt_stat->cipher,
1313 (u16)data[(*packet_size)]);
1314 /* A little extra work to differentiate among the AES key
1315 * sizes; see RFC2440 */
1316 switch(data[(*packet_size)++]) {
1317 case RFC2440_CIPHER_AES_192:
1318 crypt_stat->key_size = 24;
1319 break;
1320 default:
1321 crypt_stat->key_size =
1322 (*new_auth_tok)->session_key.encrypted_key_size;
1323 }
1324 ecryptfs_init_crypt_ctx(crypt_stat);
1325 if (unlikely(data[(*packet_size)++] != 0x03)) {
1326 printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
1327 rc = -ENOSYS;
1328 goto out_free;
1329 }
1330 /* TODO: finish the hash mapping */
1331 switch (data[(*packet_size)++]) {
1332 case 0x01: /* See RFC2440 for these numbers and their mappings */
1333 /* Choose MD5 */
1334 memcpy((*new_auth_tok)->token.password.salt,
1335 &data[(*packet_size)], ECRYPTFS_SALT_SIZE);
1336 (*packet_size) += ECRYPTFS_SALT_SIZE;
1337 /* This conversion was taken straight from RFC2440 */
1338 (*new_auth_tok)->token.password.hash_iterations =
1339 ((u32) 16 + (data[(*packet_size)] & 15))
1340 << ((data[(*packet_size)] >> 4) + 6);
1341 (*packet_size)++;
1342 /* Friendly reminder:
1343 * (*new_auth_tok)->session_key.encrypted_key_size =
1344 * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */
1345 memcpy((*new_auth_tok)->session_key.encrypted_key,
1346 &data[(*packet_size)],
1347 (*new_auth_tok)->session_key.encrypted_key_size);
1348 (*packet_size) +=
1349 (*new_auth_tok)->session_key.encrypted_key_size;
1350 (*new_auth_tok)->session_key.flags &=
1351 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1352 (*new_auth_tok)->session_key.flags |=
1353 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
1354 (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */
1355 break;
1356 default:
1357 ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: "
1358 "[%d]\n", data[(*packet_size) - 1]);
1359 rc = -ENOSYS;
1360 goto out_free;
1361 }
1362 (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD;
1363 /* TODO: Parametarize; we might actually want userspace to
1364 * decrypt the session key. */
1365 (*new_auth_tok)->session_key.flags &=
1366 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1367 (*new_auth_tok)->session_key.flags &=
1368 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
1369 list_add(&auth_tok_list_item->list, auth_tok_list);
1370 goto out;
1371 out_free:
1372 (*new_auth_tok) = NULL;
1373 memset(auth_tok_list_item, 0,
1374 sizeof(struct ecryptfs_auth_tok_list_item));
1375 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1376 auth_tok_list_item);
1377 out:
1378 if (rc)
1379 (*packet_size) = 0;
1380 return rc;
1381 }
1382
1383 /**
1384 * parse_tag_11_packet
1385 * @data: The raw bytes of the packet
1386 * @contents: This function writes the data contents of the literal
1387 * packet into this memory location
1388 * @max_contents_bytes: The maximum number of bytes that this function
1389 * is allowed to write into contents
1390 * @tag_11_contents_size: This function writes the size of the parsed
1391 * contents into this memory location; zero on
1392 * error
1393 * @packet_size: This function writes the size of the parsed packet
1394 * into this memory location; zero on error
1395 * @max_packet_size: maximum number of bytes to parse
1396 *
1397 * Returns zero on success; non-zero on error.
1398 */
1399 static int
1400 parse_tag_11_packet(unsigned char *data, unsigned char *contents,
1401 size_t max_contents_bytes, size_t *tag_11_contents_size,
1402 size_t *packet_size, size_t max_packet_size)
1403 {
1404 size_t body_size;
1405 size_t length_size;
1406 int rc = 0;
1407
1408 (*packet_size) = 0;
1409 (*tag_11_contents_size) = 0;
1410 /* This format is inspired by OpenPGP; see RFC 2440
1411 * packet tag 11
1412 *
1413 * Tag 11 identifier (1 byte)
1414 * Max Tag 11 packet size (max 3 bytes)
1415 * Binary format specifier (1 byte)
1416 * Filename length (1 byte)
1417 * Filename ("_CONSOLE") (8 bytes)
1418 * Modification date (4 bytes)
1419 * Literal data (arbitrary)
1420 *
1421 * We need at least 16 bytes of data for the packet to even be
1422 * valid.
1423 */
1424 if (max_packet_size < 16) {
1425 printk(KERN_ERR "Maximum packet size too small\n");
1426 rc = -EINVAL;
1427 goto out;
1428 }
1429 if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) {
1430 printk(KERN_WARNING "Invalid tag 11 packet format\n");
1431 rc = -EINVAL;
1432 goto out;
1433 }
1434 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1435 &length_size);
1436 if (rc) {
1437 printk(KERN_WARNING "Invalid tag 11 packet format\n");
1438 goto out;
1439 }
1440 if (body_size < 14) {
1441 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
1442 rc = -EINVAL;
1443 goto out;
1444 }
1445 (*packet_size) += length_size;
1446 (*tag_11_contents_size) = (body_size - 14);
1447 if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) {
1448 printk(KERN_ERR "Packet size exceeds max\n");
1449 rc = -EINVAL;
1450 goto out;
1451 }
1452 if (data[(*packet_size)++] != 0x62) {
1453 printk(KERN_WARNING "Unrecognizable packet\n");
1454 rc = -EINVAL;
1455 goto out;
1456 }
1457 if (data[(*packet_size)++] != 0x08) {
1458 printk(KERN_WARNING "Unrecognizable packet\n");
1459 rc = -EINVAL;
1460 goto out;
1461 }
1462 (*packet_size) += 12; /* Ignore filename and modification date */
1463 memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size));
1464 (*packet_size) += (*tag_11_contents_size);
1465 out:
1466 if (rc) {
1467 (*packet_size) = 0;
1468 (*tag_11_contents_size) = 0;
1469 }
1470 return rc;
1471 }
1472
1473 /**
1474 * ecryptfs_verify_version
1475 * @version: The version number to confirm
1476 *
1477 * Returns zero on good version; non-zero otherwise
1478 */
1479 static int ecryptfs_verify_version(u16 version)
1480 {
1481 int rc = 0;
1482 unsigned char major;
1483 unsigned char minor;
1484
1485 major = ((version >> 8) & 0xFF);
1486 minor = (version & 0xFF);
1487 if (major != ECRYPTFS_VERSION_MAJOR) {
1488 ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
1489 "Expected [%d]; got [%d]\n",
1490 ECRYPTFS_VERSION_MAJOR, major);
1491 rc = -EINVAL;
1492 goto out;
1493 }
1494 if (minor != ECRYPTFS_VERSION_MINOR) {
1495 ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
1496 "Expected [%d]; got [%d]\n",
1497 ECRYPTFS_VERSION_MINOR, minor);
1498 rc = -EINVAL;
1499 goto out;
1500 }
1501 out:
1502 return rc;
1503 }
1504
1505 int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
1506 struct ecryptfs_auth_tok **auth_tok,
1507 char *sig)
1508 {
1509 int rc = 0;
1510
1511 (*auth_tok_key) = request_key(&key_type_user, sig, NULL);
1512 if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
1513 printk(KERN_ERR "Could not find key with description: [%s]\n",
1514 sig);
1515 rc = process_request_key_err(PTR_ERR(*auth_tok_key));
1516 goto out;
1517 }
1518 (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key);
1519 if (ecryptfs_verify_version((*auth_tok)->version)) {
1520 printk(KERN_ERR
1521 "Data structure version mismatch. "
1522 "Userspace tools must match eCryptfs "
1523 "kernel module with major version [%d] "
1524 "and minor version [%d]\n",
1525 ECRYPTFS_VERSION_MAJOR,
1526 ECRYPTFS_VERSION_MINOR);
1527 rc = -EINVAL;
1528 goto out;
1529 }
1530 if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
1531 && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
1532 printk(KERN_ERR "Invalid auth_tok structure "
1533 "returned from key query\n");
1534 rc = -EINVAL;
1535 goto out;
1536 }
1537 out:
1538 return rc;
1539 }
1540
1541 /**
1542 * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok.
1543 * @auth_tok: The passphrase authentication token to use to encrypt the FEK
1544 * @crypt_stat: The cryptographic context
1545 *
1546 * Returns zero on success; non-zero error otherwise
1547 */
1548 static int
1549 decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1550 struct ecryptfs_crypt_stat *crypt_stat)
1551 {
1552 struct scatterlist dst_sg[2];
1553 struct scatterlist src_sg[2];
1554 struct mutex *tfm_mutex;
1555 struct blkcipher_desc desc = {
1556 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
1557 };
1558 int rc = 0;
1559
1560 if (unlikely(ecryptfs_verbosity > 0)) {
1561 ecryptfs_printk(
1562 KERN_DEBUG, "Session key encryption key (size [%d]):\n",
1563 auth_tok->token.password.session_key_encryption_key_bytes);
1564 ecryptfs_dump_hex(
1565 auth_tok->token.password.session_key_encryption_key,
1566 auth_tok->token.password.session_key_encryption_key_bytes);
1567 }
1568 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
1569 crypt_stat->cipher);
1570 if (unlikely(rc)) {
1571 printk(KERN_ERR "Internal error whilst attempting to get "
1572 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1573 crypt_stat->cipher, rc);
1574 goto out;
1575 }
1576 rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
1577 auth_tok->session_key.encrypted_key_size,
1578 src_sg, 2);
1579 if (rc < 1 || rc > 2) {
1580 printk(KERN_ERR "Internal error whilst attempting to convert "
1581 "auth_tok->session_key.encrypted_key to scatterlist; "
1582 "expected rc = 1; got rc = [%d]. "
1583 "auth_tok->session_key.encrypted_key_size = [%d]\n", rc,
1584 auth_tok->session_key.encrypted_key_size);
1585 goto out;
1586 }
1587 auth_tok->session_key.decrypted_key_size =
1588 auth_tok->session_key.encrypted_key_size;
1589 rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key,
1590 auth_tok->session_key.decrypted_key_size,
1591 dst_sg, 2);
1592 if (rc < 1 || rc > 2) {
1593 printk(KERN_ERR "Internal error whilst attempting to convert "
1594 "auth_tok->session_key.decrypted_key to scatterlist; "
1595 "expected rc = 1; got rc = [%d]\n", rc);
1596 goto out;
1597 }
1598 mutex_lock(tfm_mutex);
1599 rc = crypto_blkcipher_setkey(
1600 desc.tfm, auth_tok->token.password.session_key_encryption_key,
1601 crypt_stat->key_size);
1602 if (unlikely(rc < 0)) {
1603 mutex_unlock(tfm_mutex);
1604 printk(KERN_ERR "Error setting key for crypto context\n");
1605 rc = -EINVAL;
1606 goto out;
1607 }
1608 rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg,
1609 auth_tok->session_key.encrypted_key_size);
1610 mutex_unlock(tfm_mutex);
1611 if (unlikely(rc)) {
1612 printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
1613 goto out;
1614 }
1615 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1616 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1617 auth_tok->session_key.decrypted_key_size);
1618 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1619 if (unlikely(ecryptfs_verbosity > 0)) {
1620 ecryptfs_printk(KERN_DEBUG, "FEK of size [%d]:\n",
1621 crypt_stat->key_size);
1622 ecryptfs_dump_hex(crypt_stat->key,
1623 crypt_stat->key_size);
1624 }
1625 out:
1626 return rc;
1627 }
1628
1629 /**
1630 * ecryptfs_parse_packet_set
1631 * @crypt_stat: The cryptographic context
1632 * @src: Virtual address of region of memory containing the packets
1633 * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set
1634 *
1635 * Get crypt_stat to have the file's session key if the requisite key
1636 * is available to decrypt the session key.
1637 *
1638 * Returns Zero if a valid authentication token was retrieved and
1639 * processed; negative value for file not encrypted or for error
1640 * conditions.
1641 */
1642 int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
1643 unsigned char *src,
1644 struct dentry *ecryptfs_dentry)
1645 {
1646 size_t i = 0;
1647 size_t found_auth_tok;
1648 size_t next_packet_is_auth_tok_packet;
1649 struct list_head auth_tok_list;
1650 struct ecryptfs_auth_tok *matching_auth_tok;
1651 struct ecryptfs_auth_tok *candidate_auth_tok;
1652 char *candidate_auth_tok_sig;
1653 size_t packet_size;
1654 struct ecryptfs_auth_tok *new_auth_tok;
1655 unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE];
1656 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1657 size_t tag_11_contents_size;
1658 size_t tag_11_packet_size;
1659 int rc = 0;
1660
1661 INIT_LIST_HEAD(&auth_tok_list);
1662 /* Parse the header to find as many packets as we can; these will be
1663 * added the our &auth_tok_list */
1664 next_packet_is_auth_tok_packet = 1;
1665 while (next_packet_is_auth_tok_packet) {
1666 size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i);
1667
1668 switch (src[i]) {
1669 case ECRYPTFS_TAG_3_PACKET_TYPE:
1670 rc = parse_tag_3_packet(crypt_stat,
1671 (unsigned char *)&src[i],
1672 &auth_tok_list, &new_auth_tok,
1673 &packet_size, max_packet_size);
1674 if (rc) {
1675 ecryptfs_printk(KERN_ERR, "Error parsing "
1676 "tag 3 packet\n");
1677 rc = -EIO;
1678 goto out_wipe_list;
1679 }
1680 i += packet_size;
1681 rc = parse_tag_11_packet((unsigned char *)&src[i],
1682 sig_tmp_space,
1683 ECRYPTFS_SIG_SIZE,
1684 &tag_11_contents_size,
1685 &tag_11_packet_size,
1686 max_packet_size);
1687 if (rc) {
1688 ecryptfs_printk(KERN_ERR, "No valid "
1689 "(ecryptfs-specific) literal "
1690 "packet containing "
1691 "authentication token "
1692 "signature found after "
1693 "tag 3 packet\n");
1694 rc = -EIO;
1695 goto out_wipe_list;
1696 }
1697 i += tag_11_packet_size;
1698 if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) {
1699 ecryptfs_printk(KERN_ERR, "Expected "
1700 "signature of size [%d]; "
1701 "read size [%d]\n",
1702 ECRYPTFS_SIG_SIZE,
1703 tag_11_contents_size);
1704 rc = -EIO;
1705 goto out_wipe_list;
1706 }
1707 ecryptfs_to_hex(new_auth_tok->token.password.signature,
1708 sig_tmp_space, tag_11_contents_size);
1709 new_auth_tok->token.password.signature[
1710 ECRYPTFS_PASSWORD_SIG_SIZE] = '\0';
1711 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
1712 break;
1713 case ECRYPTFS_TAG_1_PACKET_TYPE:
1714 rc = parse_tag_1_packet(crypt_stat,
1715 (unsigned char *)&src[i],
1716 &auth_tok_list, &new_auth_tok,
1717 &packet_size, max_packet_size);
1718 if (rc) {
1719 ecryptfs_printk(KERN_ERR, "Error parsing "
1720 "tag 1 packet\n");
1721 rc = -EIO;
1722 goto out_wipe_list;
1723 }
1724 i += packet_size;
1725 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
1726 break;
1727 case ECRYPTFS_TAG_11_PACKET_TYPE:
1728 ecryptfs_printk(KERN_WARNING, "Invalid packet set "
1729 "(Tag 11 not allowed by itself)\n");
1730 rc = -EIO;
1731 goto out_wipe_list;
1732 break;
1733 default:
1734 ecryptfs_printk(KERN_DEBUG, "No packet at offset "
1735 "[%d] of the file header; hex value of "
1736 "character is [0x%.2x]\n", i, src[i]);
1737 next_packet_is_auth_tok_packet = 0;
1738 }
1739 }
1740 if (list_empty(&auth_tok_list)) {
1741 printk(KERN_ERR "The lower file appears to be a non-encrypted "
1742 "eCryptfs file; this is not supported in this version "
1743 "of the eCryptfs kernel module\n");
1744 rc = -EINVAL;
1745 goto out;
1746 }
1747 /* auth_tok_list contains the set of authentication tokens
1748 * parsed from the metadata. We need to find a matching
1749 * authentication token that has the secret component(s)
1750 * necessary to decrypt the EFEK in the auth_tok parsed from
1751 * the metadata. There may be several potential matches, but
1752 * just one will be sufficient to decrypt to get the FEK. */
1753 find_next_matching_auth_tok:
1754 found_auth_tok = 0;
1755 list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) {
1756 candidate_auth_tok = &auth_tok_list_item->auth_tok;
1757 if (unlikely(ecryptfs_verbosity > 0)) {
1758 ecryptfs_printk(KERN_DEBUG,
1759 "Considering cadidate auth tok:\n");
1760 ecryptfs_dump_auth_tok(candidate_auth_tok);
1761 }
1762 rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig,
1763 candidate_auth_tok);
1764 if (rc) {
1765 printk(KERN_ERR
1766 "Unrecognized candidate auth tok type: [%d]\n",
1767 candidate_auth_tok->token_type);
1768 rc = -EINVAL;
1769 goto out_wipe_list;
1770 }
1771 ecryptfs_find_auth_tok_for_sig(&matching_auth_tok,
1772 crypt_stat->mount_crypt_stat,
1773 candidate_auth_tok_sig);
1774 if (matching_auth_tok) {
1775 found_auth_tok = 1;
1776 goto found_matching_auth_tok;
1777 }
1778 }
1779 if (!found_auth_tok) {
1780 ecryptfs_printk(KERN_ERR, "Could not find a usable "
1781 "authentication token\n");
1782 rc = -EIO;
1783 goto out_wipe_list;
1784 }
1785 found_matching_auth_tok:
1786 if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
1787 memcpy(&(candidate_auth_tok->token.private_key),
1788 &(matching_auth_tok->token.private_key),
1789 sizeof(struct ecryptfs_private_key));
1790 rc = decrypt_pki_encrypted_session_key(candidate_auth_tok,
1791 crypt_stat);
1792 } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
1793 memcpy(&(candidate_auth_tok->token.password),
1794 &(matching_auth_tok->token.password),
1795 sizeof(struct ecryptfs_password));
1796 rc = decrypt_passphrase_encrypted_session_key(
1797 candidate_auth_tok, crypt_stat);
1798 }
1799 if (rc) {
1800 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1801
1802 ecryptfs_printk(KERN_WARNING, "Error decrypting the "
1803 "session key for authentication token with sig "
1804 "[%.*s]; rc = [%d]. Removing auth tok "
1805 "candidate from the list and searching for "
1806 "the next match.\n", candidate_auth_tok_sig,
1807 ECRYPTFS_SIG_SIZE_HEX, rc);
1808 list_for_each_entry_safe(auth_tok_list_item,
1809 auth_tok_list_item_tmp,
1810 &auth_tok_list, list) {
1811 if (candidate_auth_tok
1812 == &auth_tok_list_item->auth_tok) {
1813 list_del(&auth_tok_list_item->list);
1814 kmem_cache_free(
1815 ecryptfs_auth_tok_list_item_cache,
1816 auth_tok_list_item);
1817 goto find_next_matching_auth_tok;
1818 }
1819 }
1820 BUG();
1821 }
1822 rc = ecryptfs_compute_root_iv(crypt_stat);
1823 if (rc) {
1824 ecryptfs_printk(KERN_ERR, "Error computing "
1825 "the root IV\n");
1826 goto out_wipe_list;
1827 }
1828 rc = ecryptfs_init_crypt_ctx(crypt_stat);
1829 if (rc) {
1830 ecryptfs_printk(KERN_ERR, "Error initializing crypto "
1831 "context for cipher [%s]; rc = [%d]\n",
1832 crypt_stat->cipher, rc);
1833 }
1834 out_wipe_list:
1835 wipe_auth_tok_list(&auth_tok_list);
1836 out:
1837 return rc;
1838 }
1839
1840 static int
1841 pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
1842 struct ecryptfs_crypt_stat *crypt_stat,
1843 struct ecryptfs_key_record *key_rec)
1844 {
1845 struct ecryptfs_msg_ctx *msg_ctx = NULL;
1846 char *payload = NULL;
1847 size_t payload_len;
1848 struct ecryptfs_message *msg;
1849 int rc;
1850
1851 rc = write_tag_66_packet(auth_tok->token.private_key.signature,
1852 ecryptfs_code_for_cipher_string(
1853 crypt_stat->cipher,
1854 crypt_stat->key_size),
1855 crypt_stat, &payload, &payload_len);
1856 if (rc) {
1857 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
1858 goto out;
1859 }
1860 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
1861 if (rc) {
1862 ecryptfs_printk(KERN_ERR, "Error sending message to "
1863 "ecryptfsd\n");
1864 goto out;
1865 }
1866 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1867 if (rc) {
1868 ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet "
1869 "from the user space daemon\n");
1870 rc = -EIO;
1871 goto out;
1872 }
1873 rc = parse_tag_67_packet(key_rec, msg);
1874 if (rc)
1875 ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n");
1876 kfree(msg);
1877 out:
1878 kfree(payload);
1879 return rc;
1880 }
1881 /**
1882 * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet
1883 * @dest: Buffer into which to write the packet
1884 * @remaining_bytes: Maximum number of bytes that can be writtn
1885 * @auth_tok: The authentication token used for generating the tag 1 packet
1886 * @crypt_stat: The cryptographic context
1887 * @key_rec: The key record struct for the tag 1 packet
1888 * @packet_size: This function will write the number of bytes that end
1889 * up constituting the packet; set to zero on error
1890 *
1891 * Returns zero on success; non-zero on error.
1892 */
1893 static int
1894 write_tag_1_packet(char *dest, size_t *remaining_bytes,
1895 struct ecryptfs_auth_tok *auth_tok,
1896 struct ecryptfs_crypt_stat *crypt_stat,
1897 struct ecryptfs_key_record *key_rec, size_t *packet_size)
1898 {
1899 size_t i;
1900 size_t encrypted_session_key_valid = 0;
1901 size_t packet_size_length;
1902 size_t max_packet_size;
1903 int rc = 0;
1904
1905 (*packet_size) = 0;
1906 ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature,
1907 ECRYPTFS_SIG_SIZE);
1908 encrypted_session_key_valid = 0;
1909 for (i = 0; i < crypt_stat->key_size; i++)
1910 encrypted_session_key_valid |=
1911 auth_tok->session_key.encrypted_key[i];
1912 if (encrypted_session_key_valid) {
1913 memcpy(key_rec->enc_key,
1914 auth_tok->session_key.encrypted_key,
1915 auth_tok->session_key.encrypted_key_size);
1916 goto encrypted_session_key_set;
1917 }
1918 if (auth_tok->session_key.encrypted_key_size == 0)
1919 auth_tok->session_key.encrypted_key_size =
1920 auth_tok->token.private_key.key_size;
1921 rc = pki_encrypt_session_key(auth_tok, crypt_stat, key_rec);
1922 if (rc) {
1923 printk(KERN_ERR "Failed to encrypt session key via a key "
1924 "module; rc = [%d]\n", rc);
1925 goto out;
1926 }
1927 if (ecryptfs_verbosity > 0) {
1928 ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n");
1929 ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size);
1930 }
1931 encrypted_session_key_set:
1932 /* This format is inspired by OpenPGP; see RFC 2440
1933 * packet tag 1 */
1934 max_packet_size = (1 /* Tag 1 identifier */
1935 + 3 /* Max Tag 1 packet size */
1936 + 1 /* Version */
1937 + ECRYPTFS_SIG_SIZE /* Key identifier */
1938 + 1 /* Cipher identifier */
1939 + key_rec->enc_key_size); /* Encrypted key size */
1940 if (max_packet_size > (*remaining_bytes)) {
1941 printk(KERN_ERR "Packet length larger than maximum allowable; "
1942 "need up to [%td] bytes, but there are only [%td] "
1943 "available\n", max_packet_size, (*remaining_bytes));
1944 rc = -EINVAL;
1945 goto out;
1946 }
1947 dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE;
1948 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
1949 (max_packet_size - 4),
1950 &packet_size_length);
1951 if (rc) {
1952 ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet "
1953 "header; cannot generate packet length\n");
1954 goto out;
1955 }
1956 (*packet_size) += packet_size_length;
1957 dest[(*packet_size)++] = 0x03; /* version 3 */
1958 memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE);
1959 (*packet_size) += ECRYPTFS_SIG_SIZE;
1960 dest[(*packet_size)++] = RFC2440_CIPHER_RSA;
1961 memcpy(&dest[(*packet_size)], key_rec->enc_key,
1962 key_rec->enc_key_size);
1963 (*packet_size) += key_rec->enc_key_size;
1964 out:
1965 if (rc)
1966 (*packet_size) = 0;
1967 else
1968 (*remaining_bytes) -= (*packet_size);
1969 return rc;
1970 }
1971
1972 /**
1973 * write_tag_11_packet
1974 * @dest: Target into which Tag 11 packet is to be written
1975 * @remaining_bytes: Maximum packet length
1976 * @contents: Byte array of contents to copy in
1977 * @contents_length: Number of bytes in contents
1978 * @packet_length: Length of the Tag 11 packet written; zero on error
1979 *
1980 * Returns zero on success; non-zero on error.
1981 */
1982 static int
1983 write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents,
1984 size_t contents_length, size_t *packet_length)
1985 {
1986 size_t packet_size_length;
1987 size_t max_packet_size;
1988 int rc = 0;
1989
1990 (*packet_length) = 0;
1991 /* This format is inspired by OpenPGP; see RFC 2440
1992 * packet tag 11 */
1993 max_packet_size = (1 /* Tag 11 identifier */
1994 + 3 /* Max Tag 11 packet size */
1995 + 1 /* Binary format specifier */
1996 + 1 /* Filename length */
1997 + 8 /* Filename ("_CONSOLE") */
1998 + 4 /* Modification date */
1999 + contents_length); /* Literal data */
2000 if (max_packet_size > (*remaining_bytes)) {
2001 printk(KERN_ERR "Packet length larger than maximum allowable; "
2002 "need up to [%td] bytes, but there are only [%td] "
2003 "available\n", max_packet_size, (*remaining_bytes));
2004 rc = -EINVAL;
2005 goto out;
2006 }
2007 dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE;
2008 rc = ecryptfs_write_packet_length(&dest[(*packet_length)],
2009 (max_packet_size - 4),
2010 &packet_size_length);
2011 if (rc) {
2012 printk(KERN_ERR "Error generating tag 11 packet header; cannot "
2013 "generate packet length. rc = [%d]\n", rc);
2014 goto out;
2015 }
2016 (*packet_length) += packet_size_length;
2017 dest[(*packet_length)++] = 0x62; /* binary data format specifier */
2018 dest[(*packet_length)++] = 8;
2019 memcpy(&dest[(*packet_length)], "_CONSOLE", 8);
2020 (*packet_length) += 8;
2021 memset(&dest[(*packet_length)], 0x00, 4);
2022 (*packet_length) += 4;
2023 memcpy(&dest[(*packet_length)], contents, contents_length);
2024 (*packet_length) += contents_length;
2025 out:
2026 if (rc)
2027 (*packet_length) = 0;
2028 else
2029 (*remaining_bytes) -= (*packet_length);
2030 return rc;
2031 }
2032
2033 /**
2034 * write_tag_3_packet
2035 * @dest: Buffer into which to write the packet
2036 * @remaining_bytes: Maximum number of bytes that can be written
2037 * @auth_tok: Authentication token
2038 * @crypt_stat: The cryptographic context
2039 * @key_rec: encrypted key
2040 * @packet_size: This function will write the number of bytes that end
2041 * up constituting the packet; set to zero on error
2042 *
2043 * Returns zero on success; non-zero on error.
2044 */
2045 static int
2046 write_tag_3_packet(char *dest, size_t *remaining_bytes,
2047 struct ecryptfs_auth_tok *auth_tok,
2048 struct ecryptfs_crypt_stat *crypt_stat,
2049 struct ecryptfs_key_record *key_rec, size_t *packet_size)
2050 {
2051 size_t i;
2052 size_t encrypted_session_key_valid = 0;
2053 char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
2054 struct scatterlist dst_sg[2];
2055 struct scatterlist src_sg[2];
2056 struct mutex *tfm_mutex = NULL;
2057 u8 cipher_code;
2058 size_t packet_size_length;
2059 size_t max_packet_size;
2060 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2061 crypt_stat->mount_crypt_stat;
2062 struct blkcipher_desc desc = {
2063 .tfm = NULL,
2064 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
2065 };
2066 int rc = 0;
2067
2068 (*packet_size) = 0;
2069 ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
2070 ECRYPTFS_SIG_SIZE);
2071 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
2072 crypt_stat->cipher);
2073 if (unlikely(rc)) {
2074 printk(KERN_ERR "Internal error whilst attempting to get "
2075 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
2076 crypt_stat->cipher, rc);
2077 goto out;
2078 }
2079 if (mount_crypt_stat->global_default_cipher_key_size == 0) {
2080 struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm);
2081
2082 printk(KERN_WARNING "No key size specified at mount; "
2083 "defaulting to [%d]\n", alg->max_keysize);
2084 mount_crypt_stat->global_default_cipher_key_size =
2085 alg->max_keysize;
2086 }
2087 if (crypt_stat->key_size == 0)
2088 crypt_stat->key_size =
2089 mount_crypt_stat->global_default_cipher_key_size;
2090 if (auth_tok->session_key.encrypted_key_size == 0)
2091 auth_tok->session_key.encrypted_key_size =
2092 crypt_stat->key_size;
2093 if (crypt_stat->key_size == 24
2094 && strcmp("aes", crypt_stat->cipher) == 0) {
2095 memset((crypt_stat->key + 24), 0, 8);
2096 auth_tok->session_key.encrypted_key_size = 32;
2097 } else
2098 auth_tok->session_key.encrypted_key_size = crypt_stat->key_size;
2099 key_rec->enc_key_size =
2100 auth_tok->session_key.encrypted_key_size;
2101 encrypted_session_key_valid = 0;
2102 for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++)
2103 encrypted_session_key_valid |=
2104 auth_tok->session_key.encrypted_key[i];
2105 if (encrypted_session_key_valid) {
2106 ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; "
2107 "using auth_tok->session_key.encrypted_key, "
2108 "where key_rec->enc_key_size = [%d]\n",
2109 key_rec->enc_key_size);
2110 memcpy(key_rec->enc_key,
2111 auth_tok->session_key.encrypted_key,
2112 key_rec->enc_key_size);
2113 goto encrypted_session_key_set;
2114 }
2115 if (auth_tok->token.password.flags &
2116 ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) {
2117 ecryptfs_printk(KERN_DEBUG, "Using previously generated "
2118 "session key encryption key of size [%d]\n",
2119 auth_tok->token.password.
2120 session_key_encryption_key_bytes);
2121 memcpy(session_key_encryption_key,
2122 auth_tok->token.password.session_key_encryption_key,
2123 crypt_stat->key_size);
2124 ecryptfs_printk(KERN_DEBUG,
2125 "Cached session key " "encryption key: \n");
2126 if (ecryptfs_verbosity > 0)
2127 ecryptfs_dump_hex(session_key_encryption_key, 16);
2128 }
2129 if (unlikely(ecryptfs_verbosity > 0)) {
2130 ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n");
2131 ecryptfs_dump_hex(session_key_encryption_key, 16);
2132 }
2133 rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size,
2134 src_sg, 2);
2135 if (rc < 1 || rc > 2) {
2136 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
2137 "for crypt_stat session key; expected rc = 1; "
2138 "got rc = [%d]. key_rec->enc_key_size = [%d]\n",
2139 rc, key_rec->enc_key_size);
2140 rc = -ENOMEM;
2141 goto out;
2142 }
2143 rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size,
2144 dst_sg, 2);
2145 if (rc < 1 || rc > 2) {
2146 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
2147 "for crypt_stat encrypted session key; "
2148 "expected rc = 1; got rc = [%d]. "
2149 "key_rec->enc_key_size = [%d]\n", rc,
2150 key_rec->enc_key_size);
2151 rc = -ENOMEM;
2152 goto out;
2153 }
2154 mutex_lock(tfm_mutex);
2155 rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key,
2156 crypt_stat->key_size);
2157 if (rc < 0) {
2158 mutex_unlock(tfm_mutex);
2159 ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
2160 "context; rc = [%d]\n", rc);
2161 goto out;
2162 }
2163 rc = 0;
2164 ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n",
2165 crypt_stat->key_size);
2166 rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg,
2167 (*key_rec).enc_key_size);
2168 mutex_unlock(tfm_mutex);
2169 if (rc) {
2170 printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc);
2171 goto out;
2172 }
2173 ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
2174 if (ecryptfs_verbosity > 0) {
2175 ecryptfs_printk(KERN_DEBUG, "EFEK of size [%d]:\n",
2176 key_rec->enc_key_size);
2177 ecryptfs_dump_hex(key_rec->enc_key,
2178 key_rec->enc_key_size);
2179 }
2180 encrypted_session_key_set:
2181 /* This format is inspired by OpenPGP; see RFC 2440
2182 * packet tag 3 */
2183 max_packet_size = (1 /* Tag 3 identifier */
2184 + 3 /* Max Tag 3 packet size */
2185 + 1 /* Version */
2186 + 1 /* Cipher code */
2187 + 1 /* S2K specifier */
2188 + 1 /* Hash identifier */
2189 + ECRYPTFS_SALT_SIZE /* Salt */
2190 + 1 /* Hash iterations */
2191 + key_rec->enc_key_size); /* Encrypted key size */
2192 if (max_packet_size > (*remaining_bytes)) {
2193 printk(KERN_ERR "Packet too large; need up to [%td] bytes, but "
2194 "there are only [%td] available\n", max_packet_size,
2195 (*remaining_bytes));
2196 rc = -EINVAL;
2197 goto out;
2198 }
2199 dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE;
2200 /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3)
2201 * to get the number of octets in the actual Tag 3 packet */
2202 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
2203 (max_packet_size - 4),
2204 &packet_size_length);
2205 if (rc) {
2206 printk(KERN_ERR "Error generating tag 3 packet header; cannot "
2207 "generate packet length. rc = [%d]\n", rc);
2208 goto out;
2209 }
2210 (*packet_size) += packet_size_length;
2211 dest[(*packet_size)++] = 0x04; /* version 4 */
2212 /* TODO: Break from RFC2440 so that arbitrary ciphers can be
2213 * specified with strings */
2214 cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher,
2215 crypt_stat->key_size);
2216 if (cipher_code == 0) {
2217 ecryptfs_printk(KERN_WARNING, "Unable to generate code for "
2218 "cipher [%s]\n", crypt_stat->cipher);
2219 rc = -EINVAL;
2220 goto out;
2221 }
2222 dest[(*packet_size)++] = cipher_code;
2223 dest[(*packet_size)++] = 0x03; /* S2K */
2224 dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */
2225 memcpy(&dest[(*packet_size)], auth_tok->token.password.salt,
2226 ECRYPTFS_SALT_SIZE);
2227 (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */
2228 dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */
2229 memcpy(&dest[(*packet_size)], key_rec->enc_key,
2230 key_rec->enc_key_size);
2231 (*packet_size) += key_rec->enc_key_size;
2232 out:
2233 if (rc)
2234 (*packet_size) = 0;
2235 else
2236 (*remaining_bytes) -= (*packet_size);
2237 return rc;
2238 }
2239
2240 struct kmem_cache *ecryptfs_key_record_cache;
2241
2242 /**
2243 * ecryptfs_generate_key_packet_set
2244 * @dest_base: Virtual address from which to write the key record set
2245 * @crypt_stat: The cryptographic context from which the
2246 * authentication tokens will be retrieved
2247 * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat
2248 * for the global parameters
2249 * @len: The amount written
2250 * @max: The maximum amount of data allowed to be written
2251 *
2252 * Generates a key packet set and writes it to the virtual address
2253 * passed in.
2254 *
2255 * Returns zero on success; non-zero on error.
2256 */
2257 int
2258 ecryptfs_generate_key_packet_set(char *dest_base,
2259 struct ecryptfs_crypt_stat *crypt_stat,
2260 struct dentry *ecryptfs_dentry, size_t *len,
2261 size_t max)
2262 {
2263 struct ecryptfs_auth_tok *auth_tok;
2264 struct ecryptfs_global_auth_tok *global_auth_tok;
2265 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2266 &ecryptfs_superblock_to_private(
2267 ecryptfs_dentry->d_sb)->mount_crypt_stat;
2268 size_t written;
2269 struct ecryptfs_key_record *key_rec;
2270 struct ecryptfs_key_sig *key_sig;
2271 int rc = 0;
2272
2273 (*len) = 0;
2274 mutex_lock(&crypt_stat->keysig_list_mutex);
2275 key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL);
2276 if (!key_rec) {
2277 rc = -ENOMEM;
2278 goto out;
2279 }
2280 list_for_each_entry(key_sig, &crypt_stat->keysig_list,
2281 crypt_stat_list) {
2282 memset(key_rec, 0, sizeof(*key_rec));
2283 rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
2284 mount_crypt_stat,
2285 key_sig->keysig);
2286 if (rc) {
2287 printk(KERN_ERR "Error attempting to get the global "
2288 "auth_tok; rc = [%d]\n", rc);
2289 goto out_free;
2290 }
2291 if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) {
2292 printk(KERN_WARNING
2293 "Skipping invalid auth tok with sig = [%s]\n",
2294 global_auth_tok->sig);
2295 continue;
2296 }
2297 auth_tok = global_auth_tok->global_auth_tok;
2298 if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
2299 rc = write_tag_3_packet((dest_base + (*len)),
2300 &max, auth_tok,
2301 crypt_stat, key_rec,
2302 &written);
2303 if (rc) {
2304 ecryptfs_printk(KERN_WARNING, "Error "
2305 "writing tag 3 packet\n");
2306 goto out_free;
2307 }
2308 (*len) += written;
2309 /* Write auth tok signature packet */
2310 rc = write_tag_11_packet((dest_base + (*len)), &max,
2311 key_rec->sig,
2312 ECRYPTFS_SIG_SIZE, &written);
2313 if (rc) {
2314 ecryptfs_printk(KERN_ERR, "Error writing "
2315 "auth tok signature packet\n");
2316 goto out_free;
2317 }
2318 (*len) += written;
2319 } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
2320 rc = write_tag_1_packet(dest_base + (*len),
2321 &max, auth_tok,
2322 crypt_stat, key_rec, &written);
2323 if (rc) {
2324 ecryptfs_printk(KERN_WARNING, "Error "
2325 "writing tag 1 packet\n");
2326 goto out_free;
2327 }
2328 (*len) += written;
2329 } else {
2330 ecryptfs_printk(KERN_WARNING, "Unsupported "
2331 "authentication token type\n");
2332 rc = -EINVAL;
2333 goto out_free;
2334 }
2335 }
2336 if (likely(max > 0)) {
2337 dest_base[(*len)] = 0x00;
2338 } else {
2339 ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n");
2340 rc = -EIO;
2341 }
2342 out_free:
2343 kmem_cache_free(ecryptfs_key_record_cache, key_rec);
2344 out:
2345 if (rc)
2346 (*len) = 0;
2347 mutex_unlock(&crypt_stat->keysig_list_mutex);
2348 return rc;
2349 }
2350
2351 struct kmem_cache *ecryptfs_key_sig_cache;
2352
2353 int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig)
2354 {
2355 struct ecryptfs_key_sig *new_key_sig;
2356 int rc = 0;
2357
2358 new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL);
2359 if (!new_key_sig) {
2360 rc = -ENOMEM;
2361 printk(KERN_ERR
2362 "Error allocating from ecryptfs_key_sig_cache\n");
2363 goto out;
2364 }
2365 memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
2366 mutex_lock(&crypt_stat->keysig_list_mutex);
2367 list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
2368 mutex_unlock(&crypt_stat->keysig_list_mutex);
2369 out:
2370 return rc;
2371 }
2372
2373 struct kmem_cache *ecryptfs_global_auth_tok_cache;
2374
2375 int
2376 ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
2377 char *sig, u32 global_auth_tok_flags)
2378 {
2379 struct ecryptfs_global_auth_tok *new_auth_tok;
2380 int rc = 0;
2381
2382 new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache,
2383 GFP_KERNEL);
2384 if (!new_auth_tok) {
2385 rc = -ENOMEM;
2386 printk(KERN_ERR "Error allocating from "
2387 "ecryptfs_global_auth_tok_cache\n");
2388 goto out;
2389 }
2390 memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX);
2391 new_auth_tok->flags = global_auth_tok_flags;
2392 new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
2393 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
2394 list_add(&new_auth_tok->mount_crypt_stat_list,
2395 &mount_crypt_stat->global_auth_tok_list);
2396 mount_crypt_stat->num_global_auth_toks++;
2397 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
2398 out:
2399 return rc;
2400 }
2401
Support for the Chinese Samsung S3C2440 based development boards