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
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>
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.
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.
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
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 <linux/slab.h>
36 #include "ecryptfs_kernel.h"
39 * request_key returned an error instead of a valid key address;
40 * determine the type of error, make appropriate log entries, and
41 * return an error code.
43 static int process_request_key_err(long err_code
)
49 ecryptfs_printk(KERN_WARNING
, "No key\n");
53 ecryptfs_printk(KERN_WARNING
, "Key expired\n");
57 ecryptfs_printk(KERN_WARNING
, "Key revoked\n");
61 ecryptfs_printk(KERN_WARNING
, "Unknown error code: "
62 "[0x%.16lx]\n", err_code
);
69 * ecryptfs_parse_packet_length
70 * @data: Pointer to memory containing length at offset
71 * @size: This function writes the decoded size to this memory
72 * address; zero on error
73 * @length_size: The number of bytes occupied by the encoded length
75 * Returns zero on success; non-zero on error
77 int ecryptfs_parse_packet_length(unsigned char *data
, size_t *size
,
86 (*size
) = (unsigned char)data
[0];
88 } else if (data
[0] < 224) {
90 (*size
) = (((unsigned char)(data
[0]) - 192) * 256);
91 (*size
) += ((unsigned char)(data
[1]) + 192);
93 } else if (data
[0] == 255) {
94 /* Five-byte length; we're not supposed to see this */
95 ecryptfs_printk(KERN_ERR
, "Five-byte packet length not "
100 ecryptfs_printk(KERN_ERR
, "Error parsing packet length\n");
109 * ecryptfs_write_packet_length
110 * @dest: The byte array target into which to write the length. Must
111 * have at least 5 bytes allocated.
112 * @size: The length to write.
113 * @packet_size_length: The number of bytes used to encode the packet
114 * length is written to this address.
116 * Returns zero on success; non-zero on error.
118 int ecryptfs_write_packet_length(char *dest
, size_t size
,
119 size_t *packet_size_length
)
125 (*packet_size_length
) = 1;
126 } else if (size
< 65536) {
127 dest
[0] = (((size
- 192) / 256) + 192);
128 dest
[1] = ((size
- 192) % 256);
129 (*packet_size_length
) = 2;
132 ecryptfs_printk(KERN_WARNING
,
133 "Unsupported packet size: [%zd]\n", size
);
139 write_tag_64_packet(char *signature
, struct ecryptfs_session_key
*session_key
,
140 char **packet
, size_t *packet_len
)
144 size_t packet_size_len
;
149 * ***** TAG 64 Packet Format *****
150 * | Content Type | 1 byte |
151 * | Key Identifier Size | 1 or 2 bytes |
152 * | Key Identifier | arbitrary |
153 * | Encrypted File Encryption Key Size | 1 or 2 bytes |
154 * | Encrypted File Encryption Key | arbitrary |
156 data_len
= (5 + ECRYPTFS_SIG_SIZE_HEX
157 + session_key
->encrypted_key_size
);
158 *packet
= kmalloc(data_len
, GFP_KERNEL
);
161 ecryptfs_printk(KERN_ERR
, "Unable to allocate memory\n");
165 message
[i
++] = ECRYPTFS_TAG_64_PACKET_TYPE
;
166 rc
= ecryptfs_write_packet_length(&message
[i
], ECRYPTFS_SIG_SIZE_HEX
,
169 ecryptfs_printk(KERN_ERR
, "Error generating tag 64 packet "
170 "header; cannot generate packet length\n");
173 i
+= packet_size_len
;
174 memcpy(&message
[i
], signature
, ECRYPTFS_SIG_SIZE_HEX
);
175 i
+= ECRYPTFS_SIG_SIZE_HEX
;
176 rc
= ecryptfs_write_packet_length(&message
[i
],
177 session_key
->encrypted_key_size
,
180 ecryptfs_printk(KERN_ERR
, "Error generating tag 64 packet "
181 "header; cannot generate packet length\n");
184 i
+= packet_size_len
;
185 memcpy(&message
[i
], session_key
->encrypted_key
,
186 session_key
->encrypted_key_size
);
187 i
+= session_key
->encrypted_key_size
;
194 parse_tag_65_packet(struct ecryptfs_session_key
*session_key
, u8
*cipher_code
,
195 struct ecryptfs_message
*msg
)
203 u16 expected_checksum
= 0;
207 * ***** TAG 65 Packet Format *****
208 * | Content Type | 1 byte |
209 * | Status Indicator | 1 byte |
210 * | File Encryption Key Size | 1 or 2 bytes |
211 * | File Encryption Key | arbitrary |
213 message_len
= msg
->data_len
;
215 if (message_len
< 4) {
219 if (data
[i
++] != ECRYPTFS_TAG_65_PACKET_TYPE
) {
220 ecryptfs_printk(KERN_ERR
, "Type should be ECRYPTFS_TAG_65\n");
225 ecryptfs_printk(KERN_ERR
, "Status indicator has non-zero value "
226 "[%d]\n", data
[i
-1]);
230 rc
= ecryptfs_parse_packet_length(&data
[i
], &m_size
, &data_len
);
232 ecryptfs_printk(KERN_WARNING
, "Error parsing packet length; "
237 if (message_len
< (i
+ m_size
)) {
238 ecryptfs_printk(KERN_ERR
, "The message received from ecryptfsd "
239 "is shorter than expected\n");
244 ecryptfs_printk(KERN_ERR
,
245 "The decrypted key is not long enough to "
246 "include a cipher code and checksum\n");
250 *cipher_code
= data
[i
++];
251 /* The decrypted key includes 1 byte cipher code and 2 byte checksum */
252 session_key
->decrypted_key_size
= m_size
- 3;
253 if (session_key
->decrypted_key_size
> ECRYPTFS_MAX_KEY_BYTES
) {
254 ecryptfs_printk(KERN_ERR
, "key_size [%d] larger than "
255 "the maximum key size [%d]\n",
256 session_key
->decrypted_key_size
,
257 ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES
);
261 memcpy(session_key
->decrypted_key
, &data
[i
],
262 session_key
->decrypted_key_size
);
263 i
+= session_key
->decrypted_key_size
;
264 expected_checksum
+= (unsigned char)(data
[i
++]) << 8;
265 expected_checksum
+= (unsigned char)(data
[i
++]);
266 for (i
= 0; i
< session_key
->decrypted_key_size
; i
++)
267 checksum
+= session_key
->decrypted_key
[i
];
268 if (expected_checksum
!= checksum
) {
269 ecryptfs_printk(KERN_ERR
, "Invalid checksum for file "
270 "encryption key; expected [%x]; calculated "
271 "[%x]\n", expected_checksum
, checksum
);
280 write_tag_66_packet(char *signature
, u8 cipher_code
,
281 struct ecryptfs_crypt_stat
*crypt_stat
, char **packet
,
288 size_t packet_size_len
;
293 * ***** TAG 66 Packet Format *****
294 * | Content Type | 1 byte |
295 * | Key Identifier Size | 1 or 2 bytes |
296 * | Key Identifier | arbitrary |
297 * | File Encryption Key Size | 1 or 2 bytes |
298 * | File Encryption Key | arbitrary |
300 data_len
= (5 + ECRYPTFS_SIG_SIZE_HEX
+ crypt_stat
->key_size
);
301 *packet
= kmalloc(data_len
, GFP_KERNEL
);
304 ecryptfs_printk(KERN_ERR
, "Unable to allocate memory\n");
308 message
[i
++] = ECRYPTFS_TAG_66_PACKET_TYPE
;
309 rc
= ecryptfs_write_packet_length(&message
[i
], ECRYPTFS_SIG_SIZE_HEX
,
312 ecryptfs_printk(KERN_ERR
, "Error generating tag 66 packet "
313 "header; cannot generate packet length\n");
316 i
+= packet_size_len
;
317 memcpy(&message
[i
], signature
, ECRYPTFS_SIG_SIZE_HEX
);
318 i
+= ECRYPTFS_SIG_SIZE_HEX
;
319 /* The encrypted key includes 1 byte cipher code and 2 byte checksum */
320 rc
= ecryptfs_write_packet_length(&message
[i
], crypt_stat
->key_size
+ 3,
323 ecryptfs_printk(KERN_ERR
, "Error generating tag 66 packet "
324 "header; cannot generate packet length\n");
327 i
+= packet_size_len
;
328 message
[i
++] = cipher_code
;
329 memcpy(&message
[i
], crypt_stat
->key
, crypt_stat
->key_size
);
330 i
+= crypt_stat
->key_size
;
331 for (j
= 0; j
< crypt_stat
->key_size
; j
++)
332 checksum
+= crypt_stat
->key
[j
];
333 message
[i
++] = (checksum
/ 256) % 256;
334 message
[i
++] = (checksum
% 256);
341 parse_tag_67_packet(struct ecryptfs_key_record
*key_rec
,
342 struct ecryptfs_message
*msg
)
351 * ***** TAG 65 Packet Format *****
352 * | Content Type | 1 byte |
353 * | Status Indicator | 1 byte |
354 * | Encrypted File Encryption Key Size | 1 or 2 bytes |
355 * | Encrypted File Encryption Key | arbitrary |
357 message_len
= msg
->data_len
;
359 /* verify that everything through the encrypted FEK size is present */
360 if (message_len
< 4) {
362 printk(KERN_ERR
"%s: message_len is [%zd]; minimum acceptable "
363 "message length is [%d]\n", __func__
, message_len
, 4);
366 if (data
[i
++] != ECRYPTFS_TAG_67_PACKET_TYPE
) {
368 printk(KERN_ERR
"%s: Type should be ECRYPTFS_TAG_67\n",
374 printk(KERN_ERR
"%s: Status indicator has non zero "
375 "value [%d]\n", __func__
, data
[i
-1]);
379 rc
= ecryptfs_parse_packet_length(&data
[i
], &key_rec
->enc_key_size
,
382 ecryptfs_printk(KERN_WARNING
, "Error parsing packet length; "
387 if (message_len
< (i
+ key_rec
->enc_key_size
)) {
389 printk(KERN_ERR
"%s: message_len [%zd]; max len is [%zd]\n",
390 __func__
, message_len
, (i
+ key_rec
->enc_key_size
));
393 if (key_rec
->enc_key_size
> ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES
) {
395 printk(KERN_ERR
"%s: Encrypted key_size [%zd] larger than "
396 "the maximum key size [%d]\n", __func__
,
397 key_rec
->enc_key_size
,
398 ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES
);
401 memcpy(key_rec
->enc_key
, &data
[i
], key_rec
->enc_key_size
);
407 ecryptfs_find_global_auth_tok_for_sig(
408 struct ecryptfs_global_auth_tok
**global_auth_tok
,
409 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
, char *sig
)
411 struct ecryptfs_global_auth_tok
*walker
;
414 (*global_auth_tok
) = NULL
;
415 mutex_lock(&mount_crypt_stat
->global_auth_tok_list_mutex
);
416 list_for_each_entry(walker
,
417 &mount_crypt_stat
->global_auth_tok_list
,
418 mount_crypt_stat_list
) {
419 if (memcmp(walker
->sig
, sig
, ECRYPTFS_SIG_SIZE_HEX
) == 0) {
420 rc
= key_validate(walker
->global_auth_tok_key
);
422 (*global_auth_tok
) = walker
;
428 mutex_unlock(&mount_crypt_stat
->global_auth_tok_list_mutex
);
433 * ecryptfs_find_auth_tok_for_sig
434 * @auth_tok: Set to the matching auth_tok; NULL if not found
435 * @crypt_stat: inode crypt_stat crypto context
436 * @sig: Sig of auth_tok to find
438 * For now, this function simply looks at the registered auth_tok's
439 * linked off the mount_crypt_stat, so all the auth_toks that can be
440 * used must be registered at mount time. This function could
441 * potentially try a lot harder to find auth_tok's (e.g., by calling
442 * out to ecryptfsd to dynamically retrieve an auth_tok object) so
443 * that static registration of auth_tok's will no longer be necessary.
445 * Returns zero on no error; non-zero on error
448 ecryptfs_find_auth_tok_for_sig(
449 struct key
**auth_tok_key
,
450 struct ecryptfs_auth_tok
**auth_tok
,
451 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
,
454 struct ecryptfs_global_auth_tok
*global_auth_tok
;
457 (*auth_tok_key
) = NULL
;
459 if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok
,
460 mount_crypt_stat
, sig
)) {
462 /* if the flag ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY is set in the
463 * mount_crypt_stat structure, we prevent to use auth toks that
464 * are not inserted through the ecryptfs_add_global_auth_tok
467 if (mount_crypt_stat
->flags
468 & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY
)
471 rc
= ecryptfs_keyring_auth_tok_for_sig(auth_tok_key
, auth_tok
,
474 (*auth_tok
) = global_auth_tok
->global_auth_tok
;
479 * write_tag_70_packet can gobble a lot of stack space. We stuff most
480 * of the function's parameters in a kmalloc'd struct to help reduce
481 * eCryptfs' overall stack usage.
483 struct ecryptfs_write_tag_70_packet_silly_stack
{
485 size_t max_packet_size
;
486 size_t packet_size_len
;
487 size_t block_aligned_filename_size
;
491 size_t num_rand_bytes
;
492 struct mutex
*tfm_mutex
;
493 char *block_aligned_filename
;
494 struct ecryptfs_auth_tok
*auth_tok
;
495 struct scatterlist src_sg
;
496 struct scatterlist dst_sg
;
497 struct blkcipher_desc desc
;
498 char iv
[ECRYPTFS_MAX_IV_BYTES
];
499 char hash
[ECRYPTFS_TAG_70_DIGEST_SIZE
];
500 char tmp_hash
[ECRYPTFS_TAG_70_DIGEST_SIZE
];
501 struct hash_desc hash_desc
;
502 struct scatterlist hash_sg
;
506 * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK
507 * @filename: NULL-terminated filename string
509 * This is the simplest mechanism for achieving filename encryption in
510 * eCryptfs. It encrypts the given filename with the mount-wide
511 * filename encryption key (FNEK) and stores it in a packet to @dest,
512 * which the callee will encode and write directly into the dentry
516 ecryptfs_write_tag_70_packet(char *dest
, size_t *remaining_bytes
,
518 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
,
519 char *filename
, size_t filename_size
)
521 struct ecryptfs_write_tag_70_packet_silly_stack
*s
;
522 struct key
*auth_tok_key
= NULL
;
525 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
527 printk(KERN_ERR
"%s: Out of memory whilst trying to kmalloc "
528 "[%zd] bytes of kernel memory\n", __func__
, sizeof(*s
));
532 s
->desc
.flags
= CRYPTO_TFM_REQ_MAY_SLEEP
;
534 rc
= ecryptfs_get_tfm_and_mutex_for_cipher_name(
536 &s
->tfm_mutex
, mount_crypt_stat
->global_default_fn_cipher_name
);
538 printk(KERN_ERR
"Internal error whilst attempting to get "
539 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
540 mount_crypt_stat
->global_default_fn_cipher_name
, rc
);
543 mutex_lock(s
->tfm_mutex
);
544 s
->block_size
= crypto_blkcipher_blocksize(s
->desc
.tfm
);
545 /* Plus one for the \0 separator between the random prefix
546 * and the plaintext filename */
547 s
->num_rand_bytes
= (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
+ 1);
548 s
->block_aligned_filename_size
= (s
->num_rand_bytes
+ filename_size
);
549 if ((s
->block_aligned_filename_size
% s
->block_size
) != 0) {
550 s
->num_rand_bytes
+= (s
->block_size
551 - (s
->block_aligned_filename_size
553 s
->block_aligned_filename_size
= (s
->num_rand_bytes
556 /* Octet 0: Tag 70 identifier
557 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
558 * and block-aligned encrypted filename size)
559 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
560 * Octet N2-N3: Cipher identifier (1 octet)
561 * Octets N3-N4: Block-aligned encrypted filename
562 * - Consists of a minimum number of random characters, a \0
563 * separator, and then the filename */
564 s
->max_packet_size
= (1 /* Tag 70 identifier */
565 + 3 /* Max Tag 70 packet size */
566 + ECRYPTFS_SIG_SIZE
/* FNEK sig */
567 + 1 /* Cipher identifier */
568 + s
->block_aligned_filename_size
);
570 (*packet_size
) = s
->max_packet_size
;
573 if (s
->max_packet_size
> (*remaining_bytes
)) {
574 printk(KERN_WARNING
"%s: Require [%zd] bytes to write; only "
575 "[%zd] available\n", __func__
, s
->max_packet_size
,
580 s
->block_aligned_filename
= kzalloc(s
->block_aligned_filename_size
,
582 if (!s
->block_aligned_filename
) {
583 printk(KERN_ERR
"%s: Out of kernel memory whilst attempting to "
584 "kzalloc [%zd] bytes\n", __func__
,
585 s
->block_aligned_filename_size
);
590 dest
[s
->i
++] = ECRYPTFS_TAG_70_PACKET_TYPE
;
591 rc
= ecryptfs_write_packet_length(&dest
[s
->i
],
593 + 1 /* Cipher code */
594 + s
->block_aligned_filename_size
),
595 &s
->packet_size_len
);
597 printk(KERN_ERR
"%s: Error generating tag 70 packet "
598 "header; cannot generate packet length; rc = [%d]\n",
600 goto out_free_unlock
;
602 s
->i
+= s
->packet_size_len
;
603 ecryptfs_from_hex(&dest
[s
->i
],
604 mount_crypt_stat
->global_default_fnek_sig
,
606 s
->i
+= ECRYPTFS_SIG_SIZE
;
607 s
->cipher_code
= ecryptfs_code_for_cipher_string(
608 mount_crypt_stat
->global_default_fn_cipher_name
,
609 mount_crypt_stat
->global_default_fn_cipher_key_bytes
);
610 if (s
->cipher_code
== 0) {
611 printk(KERN_WARNING
"%s: Unable to generate code for "
612 "cipher [%s] with key bytes [%zd]\n", __func__
,
613 mount_crypt_stat
->global_default_fn_cipher_name
,
614 mount_crypt_stat
->global_default_fn_cipher_key_bytes
);
616 goto out_free_unlock
;
618 dest
[s
->i
++] = s
->cipher_code
;
619 rc
= ecryptfs_find_auth_tok_for_sig(
621 &s
->auth_tok
, mount_crypt_stat
,
622 mount_crypt_stat
->global_default_fnek_sig
);
624 printk(KERN_ERR
"%s: Error attempting to find auth tok for "
625 "fnek sig [%s]; rc = [%d]\n", __func__
,
626 mount_crypt_stat
->global_default_fnek_sig
, rc
);
627 goto out_free_unlock
;
629 /* TODO: Support other key modules than passphrase for
630 * filename encryption */
631 if (s
->auth_tok
->token_type
!= ECRYPTFS_PASSWORD
) {
633 printk(KERN_INFO
"%s: Filename encryption only supports "
634 "password tokens\n", __func__
);
635 goto out_free_unlock
;
639 (u8
*)s
->auth_tok
->token
.password
.session_key_encryption_key
,
640 s
->auth_tok
->token
.password
.session_key_encryption_key_bytes
);
641 s
->hash_desc
.flags
= CRYPTO_TFM_REQ_MAY_SLEEP
;
642 s
->hash_desc
.tfm
= crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST
, 0,
644 if (IS_ERR(s
->hash_desc
.tfm
)) {
645 rc
= PTR_ERR(s
->hash_desc
.tfm
);
646 printk(KERN_ERR
"%s: Error attempting to "
647 "allocate hash crypto context; rc = [%d]\n",
649 goto out_free_unlock
;
651 rc
= crypto_hash_init(&s
->hash_desc
);
654 "%s: Error initializing crypto hash; rc = [%d]\n",
656 goto out_release_free_unlock
;
658 rc
= crypto_hash_update(
659 &s
->hash_desc
, &s
->hash_sg
,
660 s
->auth_tok
->token
.password
.session_key_encryption_key_bytes
);
663 "%s: Error updating crypto hash; rc = [%d]\n",
665 goto out_release_free_unlock
;
667 rc
= crypto_hash_final(&s
->hash_desc
, s
->hash
);
670 "%s: Error finalizing crypto hash; rc = [%d]\n",
672 goto out_release_free_unlock
;
674 for (s
->j
= 0; s
->j
< (s
->num_rand_bytes
- 1); s
->j
++) {
675 s
->block_aligned_filename
[s
->j
] =
676 s
->hash
[(s
->j
% ECRYPTFS_TAG_70_DIGEST_SIZE
)];
677 if ((s
->j
% ECRYPTFS_TAG_70_DIGEST_SIZE
)
678 == (ECRYPTFS_TAG_70_DIGEST_SIZE
- 1)) {
679 sg_init_one(&s
->hash_sg
, (u8
*)s
->hash
,
680 ECRYPTFS_TAG_70_DIGEST_SIZE
);
681 rc
= crypto_hash_init(&s
->hash_desc
);
684 "%s: Error initializing crypto hash; "
685 "rc = [%d]\n", __func__
, rc
);
686 goto out_release_free_unlock
;
688 rc
= crypto_hash_update(&s
->hash_desc
, &s
->hash_sg
,
689 ECRYPTFS_TAG_70_DIGEST_SIZE
);
692 "%s: Error updating crypto hash; "
693 "rc = [%d]\n", __func__
, rc
);
694 goto out_release_free_unlock
;
696 rc
= crypto_hash_final(&s
->hash_desc
, s
->tmp_hash
);
699 "%s: Error finalizing crypto hash; "
700 "rc = [%d]\n", __func__
, rc
);
701 goto out_release_free_unlock
;
703 memcpy(s
->hash
, s
->tmp_hash
,
704 ECRYPTFS_TAG_70_DIGEST_SIZE
);
706 if (s
->block_aligned_filename
[s
->j
] == '\0')
707 s
->block_aligned_filename
[s
->j
] = ECRYPTFS_NON_NULL
;
709 memcpy(&s
->block_aligned_filename
[s
->num_rand_bytes
], filename
,
711 rc
= virt_to_scatterlist(s
->block_aligned_filename
,
712 s
->block_aligned_filename_size
, &s
->src_sg
, 1);
714 printk(KERN_ERR
"%s: Internal error whilst attempting to "
715 "convert filename memory to scatterlist; "
716 "expected rc = 1; got rc = [%d]. "
717 "block_aligned_filename_size = [%zd]\n", __func__
, rc
,
718 s
->block_aligned_filename_size
);
719 goto out_release_free_unlock
;
721 rc
= virt_to_scatterlist(&dest
[s
->i
], s
->block_aligned_filename_size
,
724 printk(KERN_ERR
"%s: Internal error whilst attempting to "
725 "convert encrypted filename memory to scatterlist; "
726 "expected rc = 1; got rc = [%d]. "
727 "block_aligned_filename_size = [%zd]\n", __func__
, rc
,
728 s
->block_aligned_filename_size
);
729 goto out_release_free_unlock
;
731 /* The characters in the first block effectively do the job
732 * of the IV here, so we just use 0's for the IV. Note the
733 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
734 * >= ECRYPTFS_MAX_IV_BYTES. */
735 memset(s
->iv
, 0, ECRYPTFS_MAX_IV_BYTES
);
736 s
->desc
.info
= s
->iv
;
737 rc
= crypto_blkcipher_setkey(
739 s
->auth_tok
->token
.password
.session_key_encryption_key
,
740 mount_crypt_stat
->global_default_fn_cipher_key_bytes
);
742 printk(KERN_ERR
"%s: Error setting key for crypto context; "
743 "rc = [%d]. s->auth_tok->token.password.session_key_"
744 "encryption_key = [0x%p]; mount_crypt_stat->"
745 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__
,
747 s
->auth_tok
->token
.password
.session_key_encryption_key
,
748 mount_crypt_stat
->global_default_fn_cipher_key_bytes
);
749 goto out_release_free_unlock
;
751 rc
= crypto_blkcipher_encrypt_iv(&s
->desc
, &s
->dst_sg
, &s
->src_sg
,
752 s
->block_aligned_filename_size
);
754 printk(KERN_ERR
"%s: Error attempting to encrypt filename; "
755 "rc = [%d]\n", __func__
, rc
);
756 goto out_release_free_unlock
;
758 s
->i
+= s
->block_aligned_filename_size
;
759 (*packet_size
) = s
->i
;
760 (*remaining_bytes
) -= (*packet_size
);
761 out_release_free_unlock
:
762 crypto_free_hash(s
->hash_desc
.tfm
);
764 kzfree(s
->block_aligned_filename
);
766 mutex_unlock(s
->tfm_mutex
);
769 key_put(auth_tok_key
);
774 struct ecryptfs_parse_tag_70_packet_silly_stack
{
776 size_t max_packet_size
;
777 size_t packet_size_len
;
778 size_t parsed_tag_70_packet_size
;
779 size_t block_aligned_filename_size
;
782 struct mutex
*tfm_mutex
;
783 char *decrypted_filename
;
784 struct ecryptfs_auth_tok
*auth_tok
;
785 struct scatterlist src_sg
;
786 struct scatterlist dst_sg
;
787 struct blkcipher_desc desc
;
788 char fnek_sig_hex
[ECRYPTFS_SIG_SIZE_HEX
+ 1];
789 char iv
[ECRYPTFS_MAX_IV_BYTES
];
790 char cipher_string
[ECRYPTFS_MAX_CIPHER_NAME_SIZE
];
794 * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet
795 * @filename: This function kmalloc's the memory for the filename
796 * @filename_size: This function sets this to the amount of memory
797 * kmalloc'd for the filename
798 * @packet_size: This function sets this to the the number of octets
799 * in the packet parsed
800 * @mount_crypt_stat: The mount-wide cryptographic context
801 * @data: The memory location containing the start of the tag 70
803 * @max_packet_size: The maximum legal size of the packet to be parsed
806 * Returns zero on success; non-zero otherwise
809 ecryptfs_parse_tag_70_packet(char **filename
, size_t *filename_size
,
811 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
,
812 char *data
, size_t max_packet_size
)
814 struct ecryptfs_parse_tag_70_packet_silly_stack
*s
;
815 struct key
*auth_tok_key
= NULL
;
819 (*filename_size
) = 0;
821 s
= kmalloc(sizeof(*s
), GFP_KERNEL
);
823 printk(KERN_ERR
"%s: Out of memory whilst trying to kmalloc "
824 "[%zd] bytes of kernel memory\n", __func__
, sizeof(*s
));
828 s
->desc
.flags
= CRYPTO_TFM_REQ_MAY_SLEEP
;
829 if (max_packet_size
< (1 + 1 + ECRYPTFS_SIG_SIZE
+ 1 + 1)) {
830 printk(KERN_WARNING
"%s: max_packet_size is [%zd]; it must be "
831 "at least [%d]\n", __func__
, max_packet_size
,
832 (1 + 1 + ECRYPTFS_SIG_SIZE
+ 1 + 1));
836 /* Octet 0: Tag 70 identifier
837 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
838 * and block-aligned encrypted filename size)
839 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
840 * Octet N2-N3: Cipher identifier (1 octet)
841 * Octets N3-N4: Block-aligned encrypted filename
842 * - Consists of a minimum number of random numbers, a \0
843 * separator, and then the filename */
844 if (data
[(*packet_size
)++] != ECRYPTFS_TAG_70_PACKET_TYPE
) {
845 printk(KERN_WARNING
"%s: Invalid packet tag [0x%.2x]; must be "
846 "tag [0x%.2x]\n", __func__
,
847 data
[((*packet_size
) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE
);
851 rc
= ecryptfs_parse_packet_length(&data
[(*packet_size
)],
852 &s
->parsed_tag_70_packet_size
,
853 &s
->packet_size_len
);
855 printk(KERN_WARNING
"%s: Error parsing packet length; "
856 "rc = [%d]\n", __func__
, rc
);
859 s
->block_aligned_filename_size
= (s
->parsed_tag_70_packet_size
860 - ECRYPTFS_SIG_SIZE
- 1);
861 if ((1 + s
->packet_size_len
+ s
->parsed_tag_70_packet_size
)
863 printk(KERN_WARNING
"%s: max_packet_size is [%zd]; real packet "
864 "size is [%zd]\n", __func__
, max_packet_size
,
865 (1 + s
->packet_size_len
+ 1
866 + s
->block_aligned_filename_size
));
870 (*packet_size
) += s
->packet_size_len
;
871 ecryptfs_to_hex(s
->fnek_sig_hex
, &data
[(*packet_size
)],
873 s
->fnek_sig_hex
[ECRYPTFS_SIG_SIZE_HEX
] = '\0';
874 (*packet_size
) += ECRYPTFS_SIG_SIZE
;
875 s
->cipher_code
= data
[(*packet_size
)++];
876 rc
= ecryptfs_cipher_code_to_string(s
->cipher_string
, s
->cipher_code
);
878 printk(KERN_WARNING
"%s: Cipher code [%d] is invalid\n",
879 __func__
, s
->cipher_code
);
882 rc
= ecryptfs_get_tfm_and_mutex_for_cipher_name(&s
->desc
.tfm
,
886 printk(KERN_ERR
"Internal error whilst attempting to get "
887 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
888 s
->cipher_string
, rc
);
891 mutex_lock(s
->tfm_mutex
);
892 rc
= virt_to_scatterlist(&data
[(*packet_size
)],
893 s
->block_aligned_filename_size
, &s
->src_sg
, 1);
895 printk(KERN_ERR
"%s: Internal error whilst attempting to "
896 "convert encrypted filename memory to scatterlist; "
897 "expected rc = 1; got rc = [%d]. "
898 "block_aligned_filename_size = [%zd]\n", __func__
, rc
,
899 s
->block_aligned_filename_size
);
902 (*packet_size
) += s
->block_aligned_filename_size
;
903 s
->decrypted_filename
= kmalloc(s
->block_aligned_filename_size
,
905 if (!s
->decrypted_filename
) {
906 printk(KERN_ERR
"%s: Out of memory whilst attempting to "
907 "kmalloc [%zd] bytes\n", __func__
,
908 s
->block_aligned_filename_size
);
912 rc
= virt_to_scatterlist(s
->decrypted_filename
,
913 s
->block_aligned_filename_size
, &s
->dst_sg
, 1);
915 printk(KERN_ERR
"%s: Internal error whilst attempting to "
916 "convert decrypted filename memory to scatterlist; "
917 "expected rc = 1; got rc = [%d]. "
918 "block_aligned_filename_size = [%zd]\n", __func__
, rc
,
919 s
->block_aligned_filename_size
);
920 goto out_free_unlock
;
922 /* The characters in the first block effectively do the job of
923 * the IV here, so we just use 0's for the IV. Note the
924 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
925 * >= ECRYPTFS_MAX_IV_BYTES. */
926 memset(s
->iv
, 0, ECRYPTFS_MAX_IV_BYTES
);
927 s
->desc
.info
= s
->iv
;
928 rc
= ecryptfs_find_auth_tok_for_sig(&auth_tok_key
,
929 &s
->auth_tok
, mount_crypt_stat
,
932 printk(KERN_ERR
"%s: Error attempting to find auth tok for "
933 "fnek sig [%s]; rc = [%d]\n", __func__
, s
->fnek_sig_hex
,
935 goto out_free_unlock
;
937 /* TODO: Support other key modules than passphrase for
938 * filename encryption */
939 if (s
->auth_tok
->token_type
!= ECRYPTFS_PASSWORD
) {
941 printk(KERN_INFO
"%s: Filename encryption only supports "
942 "password tokens\n", __func__
);
943 goto out_free_unlock
;
945 rc
= crypto_blkcipher_setkey(
947 s
->auth_tok
->token
.password
.session_key_encryption_key
,
948 mount_crypt_stat
->global_default_fn_cipher_key_bytes
);
950 printk(KERN_ERR
"%s: Error setting key for crypto context; "
951 "rc = [%d]. s->auth_tok->token.password.session_key_"
952 "encryption_key = [0x%p]; mount_crypt_stat->"
953 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__
,
955 s
->auth_tok
->token
.password
.session_key_encryption_key
,
956 mount_crypt_stat
->global_default_fn_cipher_key_bytes
);
957 goto out_free_unlock
;
959 rc
= crypto_blkcipher_decrypt_iv(&s
->desc
, &s
->dst_sg
, &s
->src_sg
,
960 s
->block_aligned_filename_size
);
962 printk(KERN_ERR
"%s: Error attempting to decrypt filename; "
963 "rc = [%d]\n", __func__
, rc
);
964 goto out_free_unlock
;
967 while (s
->decrypted_filename
[s
->i
] != '\0'
968 && s
->i
< s
->block_aligned_filename_size
)
970 if (s
->i
== s
->block_aligned_filename_size
) {
971 printk(KERN_WARNING
"%s: Invalid tag 70 packet; could not "
972 "find valid separator between random characters and "
973 "the filename\n", __func__
);
975 goto out_free_unlock
;
978 (*filename_size
) = (s
->block_aligned_filename_size
- s
->i
);
979 if (!((*filename_size
) > 0 && (*filename_size
< PATH_MAX
))) {
980 printk(KERN_WARNING
"%s: Filename size is [%zd], which is "
981 "invalid\n", __func__
, (*filename_size
));
983 goto out_free_unlock
;
985 (*filename
) = kmalloc(((*filename_size
) + 1), GFP_KERNEL
);
987 printk(KERN_ERR
"%s: Out of memory whilst attempting to "
988 "kmalloc [%zd] bytes\n", __func__
,
989 ((*filename_size
) + 1));
991 goto out_free_unlock
;
993 memcpy((*filename
), &s
->decrypted_filename
[s
->i
], (*filename_size
));
994 (*filename
)[(*filename_size
)] = '\0';
996 kfree(s
->decrypted_filename
);
998 mutex_unlock(s
->tfm_mutex
);
1002 (*filename_size
) = 0;
1006 key_put(auth_tok_key
);
1012 ecryptfs_get_auth_tok_sig(char **sig
, struct ecryptfs_auth_tok
*auth_tok
)
1017 switch (auth_tok
->token_type
) {
1018 case ECRYPTFS_PASSWORD
:
1019 (*sig
) = auth_tok
->token
.password
.signature
;
1021 case ECRYPTFS_PRIVATE_KEY
:
1022 (*sig
) = auth_tok
->token
.private_key
.signature
;
1025 printk(KERN_ERR
"Cannot get sig for auth_tok of type [%d]\n",
1026 auth_tok
->token_type
);
1033 * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok.
1034 * @auth_tok: The key authentication token used to decrypt the session key
1035 * @crypt_stat: The cryptographic context
1037 * Returns zero on success; non-zero error otherwise.
1040 decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok
*auth_tok
,
1041 struct ecryptfs_crypt_stat
*crypt_stat
)
1044 struct ecryptfs_msg_ctx
*msg_ctx
;
1045 struct ecryptfs_message
*msg
= NULL
;
1051 rc
= ecryptfs_get_auth_tok_sig(&auth_tok_sig
, auth_tok
);
1053 printk(KERN_ERR
"Unrecognized auth tok type: [%d]\n",
1054 auth_tok
->token_type
);
1057 rc
= write_tag_64_packet(auth_tok_sig
, &(auth_tok
->session_key
),
1058 &payload
, &payload_len
);
1060 ecryptfs_printk(KERN_ERR
, "Failed to write tag 64 packet\n");
1063 rc
= ecryptfs_send_message(payload
, payload_len
, &msg_ctx
);
1065 ecryptfs_printk(KERN_ERR
, "Error sending message to "
1069 rc
= ecryptfs_wait_for_response(msg_ctx
, &msg
);
1071 ecryptfs_printk(KERN_ERR
, "Failed to receive tag 65 packet "
1072 "from the user space daemon\n");
1076 rc
= parse_tag_65_packet(&(auth_tok
->session_key
),
1079 printk(KERN_ERR
"Failed to parse tag 65 packet; rc = [%d]\n",
1083 auth_tok
->session_key
.flags
|= ECRYPTFS_CONTAINS_DECRYPTED_KEY
;
1084 memcpy(crypt_stat
->key
, auth_tok
->session_key
.decrypted_key
,
1085 auth_tok
->session_key
.decrypted_key_size
);
1086 crypt_stat
->key_size
= auth_tok
->session_key
.decrypted_key_size
;
1087 rc
= ecryptfs_cipher_code_to_string(crypt_stat
->cipher
, cipher_code
);
1089 ecryptfs_printk(KERN_ERR
, "Cipher code [%d] is invalid\n",
1093 crypt_stat
->flags
|= ECRYPTFS_KEY_VALID
;
1094 if (ecryptfs_verbosity
> 0) {
1095 ecryptfs_printk(KERN_DEBUG
, "Decrypted session key:\n");
1096 ecryptfs_dump_hex(crypt_stat
->key
,
1097 crypt_stat
->key_size
);
1105 static void wipe_auth_tok_list(struct list_head
*auth_tok_list_head
)
1107 struct ecryptfs_auth_tok_list_item
*auth_tok_list_item
;
1108 struct ecryptfs_auth_tok_list_item
*auth_tok_list_item_tmp
;
1110 list_for_each_entry_safe(auth_tok_list_item
, auth_tok_list_item_tmp
,
1111 auth_tok_list_head
, list
) {
1112 list_del(&auth_tok_list_item
->list
);
1113 kmem_cache_free(ecryptfs_auth_tok_list_item_cache
,
1114 auth_tok_list_item
);
1118 struct kmem_cache
*ecryptfs_auth_tok_list_item_cache
;
1121 * parse_tag_1_packet
1122 * @crypt_stat: The cryptographic context to modify based on packet contents
1123 * @data: The raw bytes of the packet.
1124 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
1125 * a new authentication token will be placed at the
1126 * end of this list for this packet.
1127 * @new_auth_tok: Pointer to a pointer to memory that this function
1128 * allocates; sets the memory address of the pointer to
1129 * NULL on error. This object is added to the
1131 * @packet_size: This function writes the size of the parsed packet
1132 * into this memory location; zero on error.
1133 * @max_packet_size: The maximum allowable packet size
1135 * Returns zero on success; non-zero on error.
1138 parse_tag_1_packet(struct ecryptfs_crypt_stat
*crypt_stat
,
1139 unsigned char *data
, struct list_head
*auth_tok_list
,
1140 struct ecryptfs_auth_tok
**new_auth_tok
,
1141 size_t *packet_size
, size_t max_packet_size
)
1144 struct ecryptfs_auth_tok_list_item
*auth_tok_list_item
;
1149 (*new_auth_tok
) = NULL
;
1151 * This format is inspired by OpenPGP; see RFC 2440
1154 * Tag 1 identifier (1 byte)
1155 * Max Tag 1 packet size (max 3 bytes)
1157 * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE)
1158 * Cipher identifier (1 byte)
1159 * Encrypted key size (arbitrary)
1161 * 12 bytes minimum packet size
1163 if (unlikely(max_packet_size
< 12)) {
1164 printk(KERN_ERR
"Invalid max packet size; must be >=12\n");
1168 if (data
[(*packet_size
)++] != ECRYPTFS_TAG_1_PACKET_TYPE
) {
1169 printk(KERN_ERR
"Enter w/ first byte != 0x%.2x\n",
1170 ECRYPTFS_TAG_1_PACKET_TYPE
);
1174 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1175 * at end of function upon failure */
1176 auth_tok_list_item
=
1177 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache
,
1179 if (!auth_tok_list_item
) {
1180 printk(KERN_ERR
"Unable to allocate memory\n");
1184 (*new_auth_tok
) = &auth_tok_list_item
->auth_tok
;
1185 rc
= ecryptfs_parse_packet_length(&data
[(*packet_size
)], &body_size
,
1188 printk(KERN_WARNING
"Error parsing packet length; "
1192 if (unlikely(body_size
< (ECRYPTFS_SIG_SIZE
+ 2))) {
1193 printk(KERN_WARNING
"Invalid body size ([%td])\n", body_size
);
1197 (*packet_size
) += length_size
;
1198 if (unlikely((*packet_size
) + body_size
> max_packet_size
)) {
1199 printk(KERN_WARNING
"Packet size exceeds max\n");
1203 if (unlikely(data
[(*packet_size
)++] != 0x03)) {
1204 printk(KERN_WARNING
"Unknown version number [%d]\n",
1205 data
[(*packet_size
) - 1]);
1209 ecryptfs_to_hex((*new_auth_tok
)->token
.private_key
.signature
,
1210 &data
[(*packet_size
)], ECRYPTFS_SIG_SIZE
);
1211 *packet_size
+= ECRYPTFS_SIG_SIZE
;
1212 /* This byte is skipped because the kernel does not need to
1213 * know which public key encryption algorithm was used */
1215 (*new_auth_tok
)->session_key
.encrypted_key_size
=
1216 body_size
- (ECRYPTFS_SIG_SIZE
+ 2);
1217 if ((*new_auth_tok
)->session_key
.encrypted_key_size
1218 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES
) {
1219 printk(KERN_WARNING
"Tag 1 packet contains key larger "
1220 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
1224 memcpy((*new_auth_tok
)->session_key
.encrypted_key
,
1225 &data
[(*packet_size
)], (body_size
- (ECRYPTFS_SIG_SIZE
+ 2)));
1226 (*packet_size
) += (*new_auth_tok
)->session_key
.encrypted_key_size
;
1227 (*new_auth_tok
)->session_key
.flags
&=
1228 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY
;
1229 (*new_auth_tok
)->session_key
.flags
|=
1230 ECRYPTFS_CONTAINS_ENCRYPTED_KEY
;
1231 (*new_auth_tok
)->token_type
= ECRYPTFS_PRIVATE_KEY
;
1232 (*new_auth_tok
)->flags
= 0;
1233 (*new_auth_tok
)->session_key
.flags
&=
1234 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT
);
1235 (*new_auth_tok
)->session_key
.flags
&=
1236 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT
);
1237 list_add(&auth_tok_list_item
->list
, auth_tok_list
);
1240 (*new_auth_tok
) = NULL
;
1241 memset(auth_tok_list_item
, 0,
1242 sizeof(struct ecryptfs_auth_tok_list_item
));
1243 kmem_cache_free(ecryptfs_auth_tok_list_item_cache
,
1244 auth_tok_list_item
);
1252 * parse_tag_3_packet
1253 * @crypt_stat: The cryptographic context to modify based on packet
1255 * @data: The raw bytes of the packet.
1256 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
1257 * a new authentication token will be placed at the end
1258 * of this list for this packet.
1259 * @new_auth_tok: Pointer to a pointer to memory that this function
1260 * allocates; sets the memory address of the pointer to
1261 * NULL on error. This object is added to the
1263 * @packet_size: This function writes the size of the parsed packet
1264 * into this memory location; zero on error.
1265 * @max_packet_size: maximum number of bytes to parse
1267 * Returns zero on success; non-zero on error.
1270 parse_tag_3_packet(struct ecryptfs_crypt_stat
*crypt_stat
,
1271 unsigned char *data
, struct list_head
*auth_tok_list
,
1272 struct ecryptfs_auth_tok
**new_auth_tok
,
1273 size_t *packet_size
, size_t max_packet_size
)
1276 struct ecryptfs_auth_tok_list_item
*auth_tok_list_item
;
1281 (*new_auth_tok
) = NULL
;
1283 *This format is inspired by OpenPGP; see RFC 2440
1286 * Tag 3 identifier (1 byte)
1287 * Max Tag 3 packet size (max 3 bytes)
1289 * Cipher code (1 byte)
1290 * S2K specifier (1 byte)
1291 * Hash identifier (1 byte)
1292 * Salt (ECRYPTFS_SALT_SIZE)
1293 * Hash iterations (1 byte)
1294 * Encrypted key (arbitrary)
1296 * (ECRYPTFS_SALT_SIZE + 7) minimum packet size
1298 if (max_packet_size
< (ECRYPTFS_SALT_SIZE
+ 7)) {
1299 printk(KERN_ERR
"Max packet size too large\n");
1303 if (data
[(*packet_size
)++] != ECRYPTFS_TAG_3_PACKET_TYPE
) {
1304 printk(KERN_ERR
"First byte != 0x%.2x; invalid packet\n",
1305 ECRYPTFS_TAG_3_PACKET_TYPE
);
1309 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1310 * at end of function upon failure */
1311 auth_tok_list_item
=
1312 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache
, GFP_KERNEL
);
1313 if (!auth_tok_list_item
) {
1314 printk(KERN_ERR
"Unable to allocate memory\n");
1318 (*new_auth_tok
) = &auth_tok_list_item
->auth_tok
;
1319 rc
= ecryptfs_parse_packet_length(&data
[(*packet_size
)], &body_size
,
1322 printk(KERN_WARNING
"Error parsing packet length; rc = [%d]\n",
1326 if (unlikely(body_size
< (ECRYPTFS_SALT_SIZE
+ 5))) {
1327 printk(KERN_WARNING
"Invalid body size ([%td])\n", body_size
);
1331 (*packet_size
) += length_size
;
1332 if (unlikely((*packet_size
) + body_size
> max_packet_size
)) {
1333 printk(KERN_ERR
"Packet size exceeds max\n");
1337 (*new_auth_tok
)->session_key
.encrypted_key_size
=
1338 (body_size
- (ECRYPTFS_SALT_SIZE
+ 5));
1339 if ((*new_auth_tok
)->session_key
.encrypted_key_size
1340 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES
) {
1341 printk(KERN_WARNING
"Tag 3 packet contains key larger "
1342 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n");
1346 if (unlikely(data
[(*packet_size
)++] != 0x04)) {
1347 printk(KERN_WARNING
"Unknown version number [%d]\n",
1348 data
[(*packet_size
) - 1]);
1352 rc
= ecryptfs_cipher_code_to_string(crypt_stat
->cipher
,
1353 (u16
)data
[(*packet_size
)]);
1356 /* A little extra work to differentiate among the AES key
1357 * sizes; see RFC2440 */
1358 switch(data
[(*packet_size
)++]) {
1359 case RFC2440_CIPHER_AES_192
:
1360 crypt_stat
->key_size
= 24;
1363 crypt_stat
->key_size
=
1364 (*new_auth_tok
)->session_key
.encrypted_key_size
;
1366 rc
= ecryptfs_init_crypt_ctx(crypt_stat
);
1369 if (unlikely(data
[(*packet_size
)++] != 0x03)) {
1370 printk(KERN_WARNING
"Only S2K ID 3 is currently supported\n");
1374 /* TODO: finish the hash mapping */
1375 switch (data
[(*packet_size
)++]) {
1376 case 0x01: /* See RFC2440 for these numbers and their mappings */
1378 memcpy((*new_auth_tok
)->token
.password
.salt
,
1379 &data
[(*packet_size
)], ECRYPTFS_SALT_SIZE
);
1380 (*packet_size
) += ECRYPTFS_SALT_SIZE
;
1381 /* This conversion was taken straight from RFC2440 */
1382 (*new_auth_tok
)->token
.password
.hash_iterations
=
1383 ((u32
) 16 + (data
[(*packet_size
)] & 15))
1384 << ((data
[(*packet_size
)] >> 4) + 6);
1386 /* Friendly reminder:
1387 * (*new_auth_tok)->session_key.encrypted_key_size =
1388 * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */
1389 memcpy((*new_auth_tok
)->session_key
.encrypted_key
,
1390 &data
[(*packet_size
)],
1391 (*new_auth_tok
)->session_key
.encrypted_key_size
);
1393 (*new_auth_tok
)->session_key
.encrypted_key_size
;
1394 (*new_auth_tok
)->session_key
.flags
&=
1395 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY
;
1396 (*new_auth_tok
)->session_key
.flags
|=
1397 ECRYPTFS_CONTAINS_ENCRYPTED_KEY
;
1398 (*new_auth_tok
)->token
.password
.hash_algo
= 0x01; /* MD5 */
1401 ecryptfs_printk(KERN_ERR
, "Unsupported hash algorithm: "
1402 "[%d]\n", data
[(*packet_size
) - 1]);
1406 (*new_auth_tok
)->token_type
= ECRYPTFS_PASSWORD
;
1407 /* TODO: Parametarize; we might actually want userspace to
1408 * decrypt the session key. */
1409 (*new_auth_tok
)->session_key
.flags
&=
1410 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT
);
1411 (*new_auth_tok
)->session_key
.flags
&=
1412 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT
);
1413 list_add(&auth_tok_list_item
->list
, auth_tok_list
);
1416 (*new_auth_tok
) = NULL
;
1417 memset(auth_tok_list_item
, 0,
1418 sizeof(struct ecryptfs_auth_tok_list_item
));
1419 kmem_cache_free(ecryptfs_auth_tok_list_item_cache
,
1420 auth_tok_list_item
);
1428 * parse_tag_11_packet
1429 * @data: The raw bytes of the packet
1430 * @contents: This function writes the data contents of the literal
1431 * packet into this memory location
1432 * @max_contents_bytes: The maximum number of bytes that this function
1433 * is allowed to write into contents
1434 * @tag_11_contents_size: This function writes the size of the parsed
1435 * contents into this memory location; zero on
1437 * @packet_size: This function writes the size of the parsed packet
1438 * into this memory location; zero on error
1439 * @max_packet_size: maximum number of bytes to parse
1441 * Returns zero on success; non-zero on error.
1444 parse_tag_11_packet(unsigned char *data
, unsigned char *contents
,
1445 size_t max_contents_bytes
, size_t *tag_11_contents_size
,
1446 size_t *packet_size
, size_t max_packet_size
)
1453 (*tag_11_contents_size
) = 0;
1454 /* This format is inspired by OpenPGP; see RFC 2440
1457 * Tag 11 identifier (1 byte)
1458 * Max Tag 11 packet size (max 3 bytes)
1459 * Binary format specifier (1 byte)
1460 * Filename length (1 byte)
1461 * Filename ("_CONSOLE") (8 bytes)
1462 * Modification date (4 bytes)
1463 * Literal data (arbitrary)
1465 * We need at least 16 bytes of data for the packet to even be
1468 if (max_packet_size
< 16) {
1469 printk(KERN_ERR
"Maximum packet size too small\n");
1473 if (data
[(*packet_size
)++] != ECRYPTFS_TAG_11_PACKET_TYPE
) {
1474 printk(KERN_WARNING
"Invalid tag 11 packet format\n");
1478 rc
= ecryptfs_parse_packet_length(&data
[(*packet_size
)], &body_size
,
1481 printk(KERN_WARNING
"Invalid tag 11 packet format\n");
1484 if (body_size
< 14) {
1485 printk(KERN_WARNING
"Invalid body size ([%td])\n", body_size
);
1489 (*packet_size
) += length_size
;
1490 (*tag_11_contents_size
) = (body_size
- 14);
1491 if (unlikely((*packet_size
) + body_size
+ 1 > max_packet_size
)) {
1492 printk(KERN_ERR
"Packet size exceeds max\n");
1496 if (unlikely((*tag_11_contents_size
) > max_contents_bytes
)) {
1497 printk(KERN_ERR
"Literal data section in tag 11 packet exceeds "
1502 if (data
[(*packet_size
)++] != 0x62) {
1503 printk(KERN_WARNING
"Unrecognizable packet\n");
1507 if (data
[(*packet_size
)++] != 0x08) {
1508 printk(KERN_WARNING
"Unrecognizable packet\n");
1512 (*packet_size
) += 12; /* Ignore filename and modification date */
1513 memcpy(contents
, &data
[(*packet_size
)], (*tag_11_contents_size
));
1514 (*packet_size
) += (*tag_11_contents_size
);
1518 (*tag_11_contents_size
) = 0;
1524 * ecryptfs_verify_version
1525 * @version: The version number to confirm
1527 * Returns zero on good version; non-zero otherwise
1529 static int ecryptfs_verify_version(u16 version
)
1532 unsigned char major
;
1533 unsigned char minor
;
1535 major
= ((version
>> 8) & 0xFF);
1536 minor
= (version
& 0xFF);
1537 if (major
!= ECRYPTFS_VERSION_MAJOR
) {
1538 ecryptfs_printk(KERN_ERR
, "Major version number mismatch. "
1539 "Expected [%d]; got [%d]\n",
1540 ECRYPTFS_VERSION_MAJOR
, major
);
1544 if (minor
!= ECRYPTFS_VERSION_MINOR
) {
1545 ecryptfs_printk(KERN_ERR
, "Minor version number mismatch. "
1546 "Expected [%d]; got [%d]\n",
1547 ECRYPTFS_VERSION_MINOR
, minor
);
1555 int ecryptfs_keyring_auth_tok_for_sig(struct key
**auth_tok_key
,
1556 struct ecryptfs_auth_tok
**auth_tok
,
1561 (*auth_tok_key
) = request_key(&key_type_user
, sig
, NULL
);
1562 if (!(*auth_tok_key
) || IS_ERR(*auth_tok_key
)) {
1563 printk(KERN_ERR
"Could not find key with description: [%s]\n",
1565 rc
= process_request_key_err(PTR_ERR(*auth_tok_key
));
1566 (*auth_tok_key
) = NULL
;
1569 (*auth_tok
) = ecryptfs_get_key_payload_data(*auth_tok_key
);
1570 if (ecryptfs_verify_version((*auth_tok
)->version
)) {
1572 "Data structure version mismatch. "
1573 "Userspace tools must match eCryptfs "
1574 "kernel module with major version [%d] "
1575 "and minor version [%d]\n",
1576 ECRYPTFS_VERSION_MAJOR
,
1577 ECRYPTFS_VERSION_MINOR
);
1579 goto out_release_key
;
1581 if ((*auth_tok
)->token_type
!= ECRYPTFS_PASSWORD
1582 && (*auth_tok
)->token_type
!= ECRYPTFS_PRIVATE_KEY
) {
1583 printk(KERN_ERR
"Invalid auth_tok structure "
1584 "returned from key query\n");
1586 goto out_release_key
;
1590 key_put(*auth_tok_key
);
1591 (*auth_tok_key
) = NULL
;
1598 * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok.
1599 * @auth_tok: The passphrase authentication token to use to encrypt the FEK
1600 * @crypt_stat: The cryptographic context
1602 * Returns zero on success; non-zero error otherwise
1605 decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok
*auth_tok
,
1606 struct ecryptfs_crypt_stat
*crypt_stat
)
1608 struct scatterlist dst_sg
[2];
1609 struct scatterlist src_sg
[2];
1610 struct mutex
*tfm_mutex
;
1611 struct blkcipher_desc desc
= {
1612 .flags
= CRYPTO_TFM_REQ_MAY_SLEEP
1616 if (unlikely(ecryptfs_verbosity
> 0)) {
1618 KERN_DEBUG
, "Session key encryption key (size [%d]):\n",
1619 auth_tok
->token
.password
.session_key_encryption_key_bytes
);
1621 auth_tok
->token
.password
.session_key_encryption_key
,
1622 auth_tok
->token
.password
.session_key_encryption_key_bytes
);
1624 rc
= ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc
.tfm
, &tfm_mutex
,
1625 crypt_stat
->cipher
);
1627 printk(KERN_ERR
"Internal error whilst attempting to get "
1628 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1629 crypt_stat
->cipher
, rc
);
1632 rc
= virt_to_scatterlist(auth_tok
->session_key
.encrypted_key
,
1633 auth_tok
->session_key
.encrypted_key_size
,
1635 if (rc
< 1 || rc
> 2) {
1636 printk(KERN_ERR
"Internal error whilst attempting to convert "
1637 "auth_tok->session_key.encrypted_key to scatterlist; "
1638 "expected rc = 1; got rc = [%d]. "
1639 "auth_tok->session_key.encrypted_key_size = [%d]\n", rc
,
1640 auth_tok
->session_key
.encrypted_key_size
);
1643 auth_tok
->session_key
.decrypted_key_size
=
1644 auth_tok
->session_key
.encrypted_key_size
;
1645 rc
= virt_to_scatterlist(auth_tok
->session_key
.decrypted_key
,
1646 auth_tok
->session_key
.decrypted_key_size
,
1648 if (rc
< 1 || rc
> 2) {
1649 printk(KERN_ERR
"Internal error whilst attempting to convert "
1650 "auth_tok->session_key.decrypted_key to scatterlist; "
1651 "expected rc = 1; got rc = [%d]\n", rc
);
1654 mutex_lock(tfm_mutex
);
1655 rc
= crypto_blkcipher_setkey(
1656 desc
.tfm
, auth_tok
->token
.password
.session_key_encryption_key
,
1657 crypt_stat
->key_size
);
1658 if (unlikely(rc
< 0)) {
1659 mutex_unlock(tfm_mutex
);
1660 printk(KERN_ERR
"Error setting key for crypto context\n");
1664 rc
= crypto_blkcipher_decrypt(&desc
, dst_sg
, src_sg
,
1665 auth_tok
->session_key
.encrypted_key_size
);
1666 mutex_unlock(tfm_mutex
);
1668 printk(KERN_ERR
"Error decrypting; rc = [%d]\n", rc
);
1671 auth_tok
->session_key
.flags
|= ECRYPTFS_CONTAINS_DECRYPTED_KEY
;
1672 memcpy(crypt_stat
->key
, auth_tok
->session_key
.decrypted_key
,
1673 auth_tok
->session_key
.decrypted_key_size
);
1674 crypt_stat
->flags
|= ECRYPTFS_KEY_VALID
;
1675 if (unlikely(ecryptfs_verbosity
> 0)) {
1676 ecryptfs_printk(KERN_DEBUG
, "FEK of size [%zd]:\n",
1677 crypt_stat
->key_size
);
1678 ecryptfs_dump_hex(crypt_stat
->key
,
1679 crypt_stat
->key_size
);
1686 * ecryptfs_parse_packet_set
1687 * @crypt_stat: The cryptographic context
1688 * @src: Virtual address of region of memory containing the packets
1689 * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set
1691 * Get crypt_stat to have the file's session key if the requisite key
1692 * is available to decrypt the session key.
1694 * Returns Zero if a valid authentication token was retrieved and
1695 * processed; negative value for file not encrypted or for error
1698 int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat
*crypt_stat
,
1700 struct dentry
*ecryptfs_dentry
)
1703 size_t found_auth_tok
;
1704 size_t next_packet_is_auth_tok_packet
;
1705 struct list_head auth_tok_list
;
1706 struct ecryptfs_auth_tok
*matching_auth_tok
;
1707 struct ecryptfs_auth_tok
*candidate_auth_tok
;
1708 char *candidate_auth_tok_sig
;
1710 struct ecryptfs_auth_tok
*new_auth_tok
;
1711 unsigned char sig_tmp_space
[ECRYPTFS_SIG_SIZE
];
1712 struct ecryptfs_auth_tok_list_item
*auth_tok_list_item
;
1713 size_t tag_11_contents_size
;
1714 size_t tag_11_packet_size
;
1715 struct key
*auth_tok_key
= NULL
;
1718 INIT_LIST_HEAD(&auth_tok_list
);
1719 /* Parse the header to find as many packets as we can; these will be
1720 * added the our &auth_tok_list */
1721 next_packet_is_auth_tok_packet
= 1;
1722 while (next_packet_is_auth_tok_packet
) {
1723 size_t max_packet_size
= ((PAGE_CACHE_SIZE
- 8) - i
);
1726 case ECRYPTFS_TAG_3_PACKET_TYPE
:
1727 rc
= parse_tag_3_packet(crypt_stat
,
1728 (unsigned char *)&src
[i
],
1729 &auth_tok_list
, &new_auth_tok
,
1730 &packet_size
, max_packet_size
);
1732 ecryptfs_printk(KERN_ERR
, "Error parsing "
1738 rc
= parse_tag_11_packet((unsigned char *)&src
[i
],
1741 &tag_11_contents_size
,
1742 &tag_11_packet_size
,
1745 ecryptfs_printk(KERN_ERR
, "No valid "
1746 "(ecryptfs-specific) literal "
1747 "packet containing "
1748 "authentication token "
1749 "signature found after "
1754 i
+= tag_11_packet_size
;
1755 if (ECRYPTFS_SIG_SIZE
!= tag_11_contents_size
) {
1756 ecryptfs_printk(KERN_ERR
, "Expected "
1757 "signature of size [%d]; "
1758 "read size [%zd]\n",
1760 tag_11_contents_size
);
1764 ecryptfs_to_hex(new_auth_tok
->token
.password
.signature
,
1765 sig_tmp_space
, tag_11_contents_size
);
1766 new_auth_tok
->token
.password
.signature
[
1767 ECRYPTFS_PASSWORD_SIG_SIZE
] = '\0';
1768 crypt_stat
->flags
|= ECRYPTFS_ENCRYPTED
;
1770 case ECRYPTFS_TAG_1_PACKET_TYPE
:
1771 rc
= parse_tag_1_packet(crypt_stat
,
1772 (unsigned char *)&src
[i
],
1773 &auth_tok_list
, &new_auth_tok
,
1774 &packet_size
, max_packet_size
);
1776 ecryptfs_printk(KERN_ERR
, "Error parsing "
1782 crypt_stat
->flags
|= ECRYPTFS_ENCRYPTED
;
1784 case ECRYPTFS_TAG_11_PACKET_TYPE
:
1785 ecryptfs_printk(KERN_WARNING
, "Invalid packet set "
1786 "(Tag 11 not allowed by itself)\n");
1791 ecryptfs_printk(KERN_DEBUG
, "No packet at offset [%zd] "
1792 "of the file header; hex value of "
1793 "character is [0x%.2x]\n", i
, src
[i
]);
1794 next_packet_is_auth_tok_packet
= 0;
1797 if (list_empty(&auth_tok_list
)) {
1798 printk(KERN_ERR
"The lower file appears to be a non-encrypted "
1799 "eCryptfs file; this is not supported in this version "
1800 "of the eCryptfs kernel module\n");
1804 /* auth_tok_list contains the set of authentication tokens
1805 * parsed from the metadata. We need to find a matching
1806 * authentication token that has the secret component(s)
1807 * necessary to decrypt the EFEK in the auth_tok parsed from
1808 * the metadata. There may be several potential matches, but
1809 * just one will be sufficient to decrypt to get the FEK. */
1810 find_next_matching_auth_tok
:
1813 key_put(auth_tok_key
);
1814 auth_tok_key
= NULL
;
1816 list_for_each_entry(auth_tok_list_item
, &auth_tok_list
, list
) {
1817 candidate_auth_tok
= &auth_tok_list_item
->auth_tok
;
1818 if (unlikely(ecryptfs_verbosity
> 0)) {
1819 ecryptfs_printk(KERN_DEBUG
,
1820 "Considering cadidate auth tok:\n");
1821 ecryptfs_dump_auth_tok(candidate_auth_tok
);
1823 rc
= ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig
,
1824 candidate_auth_tok
);
1827 "Unrecognized candidate auth tok type: [%d]\n",
1828 candidate_auth_tok
->token_type
);
1832 rc
= ecryptfs_find_auth_tok_for_sig(&auth_tok_key
,
1834 crypt_stat
->mount_crypt_stat
,
1835 candidate_auth_tok_sig
);
1838 goto found_matching_auth_tok
;
1841 if (!found_auth_tok
) {
1842 ecryptfs_printk(KERN_ERR
, "Could not find a usable "
1843 "authentication token\n");
1847 found_matching_auth_tok
:
1848 if (candidate_auth_tok
->token_type
== ECRYPTFS_PRIVATE_KEY
) {
1849 memcpy(&(candidate_auth_tok
->token
.private_key
),
1850 &(matching_auth_tok
->token
.private_key
),
1851 sizeof(struct ecryptfs_private_key
));
1852 rc
= decrypt_pki_encrypted_session_key(candidate_auth_tok
,
1854 } else if (candidate_auth_tok
->token_type
== ECRYPTFS_PASSWORD
) {
1855 memcpy(&(candidate_auth_tok
->token
.password
),
1856 &(matching_auth_tok
->token
.password
),
1857 sizeof(struct ecryptfs_password
));
1858 rc
= decrypt_passphrase_encrypted_session_key(
1859 candidate_auth_tok
, crypt_stat
);
1862 struct ecryptfs_auth_tok_list_item
*auth_tok_list_item_tmp
;
1864 ecryptfs_printk(KERN_WARNING
, "Error decrypting the "
1865 "session key for authentication token with sig "
1866 "[%.*s]; rc = [%d]. Removing auth tok "
1867 "candidate from the list and searching for "
1868 "the next match.\n", ECRYPTFS_SIG_SIZE_HEX
,
1869 candidate_auth_tok_sig
, rc
);
1870 list_for_each_entry_safe(auth_tok_list_item
,
1871 auth_tok_list_item_tmp
,
1872 &auth_tok_list
, list
) {
1873 if (candidate_auth_tok
1874 == &auth_tok_list_item
->auth_tok
) {
1875 list_del(&auth_tok_list_item
->list
);
1877 ecryptfs_auth_tok_list_item_cache
,
1878 auth_tok_list_item
);
1879 goto find_next_matching_auth_tok
;
1884 rc
= ecryptfs_compute_root_iv(crypt_stat
);
1886 ecryptfs_printk(KERN_ERR
, "Error computing "
1890 rc
= ecryptfs_init_crypt_ctx(crypt_stat
);
1892 ecryptfs_printk(KERN_ERR
, "Error initializing crypto "
1893 "context for cipher [%s]; rc = [%d]\n",
1894 crypt_stat
->cipher
, rc
);
1897 wipe_auth_tok_list(&auth_tok_list
);
1900 key_put(auth_tok_key
);
1905 pki_encrypt_session_key(struct ecryptfs_auth_tok
*auth_tok
,
1906 struct ecryptfs_crypt_stat
*crypt_stat
,
1907 struct ecryptfs_key_record
*key_rec
)
1909 struct ecryptfs_msg_ctx
*msg_ctx
= NULL
;
1910 char *payload
= NULL
;
1912 struct ecryptfs_message
*msg
;
1915 rc
= write_tag_66_packet(auth_tok
->token
.private_key
.signature
,
1916 ecryptfs_code_for_cipher_string(
1918 crypt_stat
->key_size
),
1919 crypt_stat
, &payload
, &payload_len
);
1921 ecryptfs_printk(KERN_ERR
, "Error generating tag 66 packet\n");
1924 rc
= ecryptfs_send_message(payload
, payload_len
, &msg_ctx
);
1926 ecryptfs_printk(KERN_ERR
, "Error sending message to "
1930 rc
= ecryptfs_wait_for_response(msg_ctx
, &msg
);
1932 ecryptfs_printk(KERN_ERR
, "Failed to receive tag 67 packet "
1933 "from the user space daemon\n");
1937 rc
= parse_tag_67_packet(key_rec
, msg
);
1939 ecryptfs_printk(KERN_ERR
, "Error parsing tag 67 packet\n");
1946 * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet
1947 * @dest: Buffer into which to write the packet
1948 * @remaining_bytes: Maximum number of bytes that can be writtn
1949 * @auth_tok: The authentication token used for generating the tag 1 packet
1950 * @crypt_stat: The cryptographic context
1951 * @key_rec: The key record struct for the tag 1 packet
1952 * @packet_size: This function will write the number of bytes that end
1953 * up constituting the packet; set to zero on error
1955 * Returns zero on success; non-zero on error.
1958 write_tag_1_packet(char *dest
, size_t *remaining_bytes
,
1959 struct ecryptfs_auth_tok
*auth_tok
,
1960 struct ecryptfs_crypt_stat
*crypt_stat
,
1961 struct ecryptfs_key_record
*key_rec
, size_t *packet_size
)
1964 size_t encrypted_session_key_valid
= 0;
1965 size_t packet_size_length
;
1966 size_t max_packet_size
;
1970 ecryptfs_from_hex(key_rec
->sig
, auth_tok
->token
.private_key
.signature
,
1972 encrypted_session_key_valid
= 0;
1973 for (i
= 0; i
< crypt_stat
->key_size
; i
++)
1974 encrypted_session_key_valid
|=
1975 auth_tok
->session_key
.encrypted_key
[i
];
1976 if (encrypted_session_key_valid
) {
1977 memcpy(key_rec
->enc_key
,
1978 auth_tok
->session_key
.encrypted_key
,
1979 auth_tok
->session_key
.encrypted_key_size
);
1980 goto encrypted_session_key_set
;
1982 if (auth_tok
->session_key
.encrypted_key_size
== 0)
1983 auth_tok
->session_key
.encrypted_key_size
=
1984 auth_tok
->token
.private_key
.key_size
;
1985 rc
= pki_encrypt_session_key(auth_tok
, crypt_stat
, key_rec
);
1987 printk(KERN_ERR
"Failed to encrypt session key via a key "
1988 "module; rc = [%d]\n", rc
);
1991 if (ecryptfs_verbosity
> 0) {
1992 ecryptfs_printk(KERN_DEBUG
, "Encrypted key:\n");
1993 ecryptfs_dump_hex(key_rec
->enc_key
, key_rec
->enc_key_size
);
1995 encrypted_session_key_set
:
1996 /* This format is inspired by OpenPGP; see RFC 2440
1998 max_packet_size
= (1 /* Tag 1 identifier */
1999 + 3 /* Max Tag 1 packet size */
2001 + ECRYPTFS_SIG_SIZE
/* Key identifier */
2002 + 1 /* Cipher identifier */
2003 + key_rec
->enc_key_size
); /* Encrypted key size */
2004 if (max_packet_size
> (*remaining_bytes
)) {
2005 printk(KERN_ERR
"Packet length larger than maximum allowable; "
2006 "need up to [%td] bytes, but there are only [%td] "
2007 "available\n", max_packet_size
, (*remaining_bytes
));
2011 dest
[(*packet_size
)++] = ECRYPTFS_TAG_1_PACKET_TYPE
;
2012 rc
= ecryptfs_write_packet_length(&dest
[(*packet_size
)],
2013 (max_packet_size
- 4),
2014 &packet_size_length
);
2016 ecryptfs_printk(KERN_ERR
, "Error generating tag 1 packet "
2017 "header; cannot generate packet length\n");
2020 (*packet_size
) += packet_size_length
;
2021 dest
[(*packet_size
)++] = 0x03; /* version 3 */
2022 memcpy(&dest
[(*packet_size
)], key_rec
->sig
, ECRYPTFS_SIG_SIZE
);
2023 (*packet_size
) += ECRYPTFS_SIG_SIZE
;
2024 dest
[(*packet_size
)++] = RFC2440_CIPHER_RSA
;
2025 memcpy(&dest
[(*packet_size
)], key_rec
->enc_key
,
2026 key_rec
->enc_key_size
);
2027 (*packet_size
) += key_rec
->enc_key_size
;
2032 (*remaining_bytes
) -= (*packet_size
);
2037 * write_tag_11_packet
2038 * @dest: Target into which Tag 11 packet is to be written
2039 * @remaining_bytes: Maximum packet length
2040 * @contents: Byte array of contents to copy in
2041 * @contents_length: Number of bytes in contents
2042 * @packet_length: Length of the Tag 11 packet written; zero on error
2044 * Returns zero on success; non-zero on error.
2047 write_tag_11_packet(char *dest
, size_t *remaining_bytes
, char *contents
,
2048 size_t contents_length
, size_t *packet_length
)
2050 size_t packet_size_length
;
2051 size_t max_packet_size
;
2054 (*packet_length
) = 0;
2055 /* This format is inspired by OpenPGP; see RFC 2440
2057 max_packet_size
= (1 /* Tag 11 identifier */
2058 + 3 /* Max Tag 11 packet size */
2059 + 1 /* Binary format specifier */
2060 + 1 /* Filename length */
2061 + 8 /* Filename ("_CONSOLE") */
2062 + 4 /* Modification date */
2063 + contents_length
); /* Literal data */
2064 if (max_packet_size
> (*remaining_bytes
)) {
2065 printk(KERN_ERR
"Packet length larger than maximum allowable; "
2066 "need up to [%td] bytes, but there are only [%td] "
2067 "available\n", max_packet_size
, (*remaining_bytes
));
2071 dest
[(*packet_length
)++] = ECRYPTFS_TAG_11_PACKET_TYPE
;
2072 rc
= ecryptfs_write_packet_length(&dest
[(*packet_length
)],
2073 (max_packet_size
- 4),
2074 &packet_size_length
);
2076 printk(KERN_ERR
"Error generating tag 11 packet header; cannot "
2077 "generate packet length. rc = [%d]\n", rc
);
2080 (*packet_length
) += packet_size_length
;
2081 dest
[(*packet_length
)++] = 0x62; /* binary data format specifier */
2082 dest
[(*packet_length
)++] = 8;
2083 memcpy(&dest
[(*packet_length
)], "_CONSOLE", 8);
2084 (*packet_length
) += 8;
2085 memset(&dest
[(*packet_length
)], 0x00, 4);
2086 (*packet_length
) += 4;
2087 memcpy(&dest
[(*packet_length
)], contents
, contents_length
);
2088 (*packet_length
) += contents_length
;
2091 (*packet_length
) = 0;
2093 (*remaining_bytes
) -= (*packet_length
);
2098 * write_tag_3_packet
2099 * @dest: Buffer into which to write the packet
2100 * @remaining_bytes: Maximum number of bytes that can be written
2101 * @auth_tok: Authentication token
2102 * @crypt_stat: The cryptographic context
2103 * @key_rec: encrypted key
2104 * @packet_size: This function will write the number of bytes that end
2105 * up constituting the packet; set to zero on error
2107 * Returns zero on success; non-zero on error.
2110 write_tag_3_packet(char *dest
, size_t *remaining_bytes
,
2111 struct ecryptfs_auth_tok
*auth_tok
,
2112 struct ecryptfs_crypt_stat
*crypt_stat
,
2113 struct ecryptfs_key_record
*key_rec
, size_t *packet_size
)
2116 size_t encrypted_session_key_valid
= 0;
2117 char session_key_encryption_key
[ECRYPTFS_MAX_KEY_BYTES
];
2118 struct scatterlist dst_sg
[2];
2119 struct scatterlist src_sg
[2];
2120 struct mutex
*tfm_mutex
= NULL
;
2122 size_t packet_size_length
;
2123 size_t max_packet_size
;
2124 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
=
2125 crypt_stat
->mount_crypt_stat
;
2126 struct blkcipher_desc desc
= {
2128 .flags
= CRYPTO_TFM_REQ_MAY_SLEEP
2133 ecryptfs_from_hex(key_rec
->sig
, auth_tok
->token
.password
.signature
,
2135 rc
= ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc
.tfm
, &tfm_mutex
,
2136 crypt_stat
->cipher
);
2138 printk(KERN_ERR
"Internal error whilst attempting to get "
2139 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
2140 crypt_stat
->cipher
, rc
);
2143 if (mount_crypt_stat
->global_default_cipher_key_size
== 0) {
2144 struct blkcipher_alg
*alg
= crypto_blkcipher_alg(desc
.tfm
);
2146 printk(KERN_WARNING
"No key size specified at mount; "
2147 "defaulting to [%d]\n", alg
->max_keysize
);
2148 mount_crypt_stat
->global_default_cipher_key_size
=
2151 if (crypt_stat
->key_size
== 0)
2152 crypt_stat
->key_size
=
2153 mount_crypt_stat
->global_default_cipher_key_size
;
2154 if (auth_tok
->session_key
.encrypted_key_size
== 0)
2155 auth_tok
->session_key
.encrypted_key_size
=
2156 crypt_stat
->key_size
;
2157 if (crypt_stat
->key_size
== 24
2158 && strcmp("aes", crypt_stat
->cipher
) == 0) {
2159 memset((crypt_stat
->key
+ 24), 0, 8);
2160 auth_tok
->session_key
.encrypted_key_size
= 32;
2162 auth_tok
->session_key
.encrypted_key_size
= crypt_stat
->key_size
;
2163 key_rec
->enc_key_size
=
2164 auth_tok
->session_key
.encrypted_key_size
;
2165 encrypted_session_key_valid
= 0;
2166 for (i
= 0; i
< auth_tok
->session_key
.encrypted_key_size
; i
++)
2167 encrypted_session_key_valid
|=
2168 auth_tok
->session_key
.encrypted_key
[i
];
2169 if (encrypted_session_key_valid
) {
2170 ecryptfs_printk(KERN_DEBUG
, "encrypted_session_key_valid != 0; "
2171 "using auth_tok->session_key.encrypted_key, "
2172 "where key_rec->enc_key_size = [%zd]\n",
2173 key_rec
->enc_key_size
);
2174 memcpy(key_rec
->enc_key
,
2175 auth_tok
->session_key
.encrypted_key
,
2176 key_rec
->enc_key_size
);
2177 goto encrypted_session_key_set
;
2179 if (auth_tok
->token
.password
.flags
&
2180 ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET
) {
2181 ecryptfs_printk(KERN_DEBUG
, "Using previously generated "
2182 "session key encryption key of size [%d]\n",
2183 auth_tok
->token
.password
.
2184 session_key_encryption_key_bytes
);
2185 memcpy(session_key_encryption_key
,
2186 auth_tok
->token
.password
.session_key_encryption_key
,
2187 crypt_stat
->key_size
);
2188 ecryptfs_printk(KERN_DEBUG
,
2189 "Cached session key " "encryption key: \n");
2190 if (ecryptfs_verbosity
> 0)
2191 ecryptfs_dump_hex(session_key_encryption_key
, 16);
2193 if (unlikely(ecryptfs_verbosity
> 0)) {
2194 ecryptfs_printk(KERN_DEBUG
, "Session key encryption key:\n");
2195 ecryptfs_dump_hex(session_key_encryption_key
, 16);
2197 rc
= virt_to_scatterlist(crypt_stat
->key
, key_rec
->enc_key_size
,
2199 if (rc
< 1 || rc
> 2) {
2200 ecryptfs_printk(KERN_ERR
, "Error generating scatterlist "
2201 "for crypt_stat session key; expected rc = 1; "
2202 "got rc = [%d]. key_rec->enc_key_size = [%zd]\n",
2203 rc
, key_rec
->enc_key_size
);
2207 rc
= virt_to_scatterlist(key_rec
->enc_key
, key_rec
->enc_key_size
,
2209 if (rc
< 1 || rc
> 2) {
2210 ecryptfs_printk(KERN_ERR
, "Error generating scatterlist "
2211 "for crypt_stat encrypted session key; "
2212 "expected rc = 1; got rc = [%d]. "
2213 "key_rec->enc_key_size = [%zd]\n", rc
,
2214 key_rec
->enc_key_size
);
2218 mutex_lock(tfm_mutex
);
2219 rc
= crypto_blkcipher_setkey(desc
.tfm
, session_key_encryption_key
,
2220 crypt_stat
->key_size
);
2222 mutex_unlock(tfm_mutex
);
2223 ecryptfs_printk(KERN_ERR
, "Error setting key for crypto "
2224 "context; rc = [%d]\n", rc
);
2228 ecryptfs_printk(KERN_DEBUG
, "Encrypting [%zd] bytes of the key\n",
2229 crypt_stat
->key_size
);
2230 rc
= crypto_blkcipher_encrypt(&desc
, dst_sg
, src_sg
,
2231 (*key_rec
).enc_key_size
);
2232 mutex_unlock(tfm_mutex
);
2234 printk(KERN_ERR
"Error encrypting; rc = [%d]\n", rc
);
2237 ecryptfs_printk(KERN_DEBUG
, "This should be the encrypted key:\n");
2238 if (ecryptfs_verbosity
> 0) {
2239 ecryptfs_printk(KERN_DEBUG
, "EFEK of size [%zd]:\n",
2240 key_rec
->enc_key_size
);
2241 ecryptfs_dump_hex(key_rec
->enc_key
,
2242 key_rec
->enc_key_size
);
2244 encrypted_session_key_set
:
2245 /* This format is inspired by OpenPGP; see RFC 2440
2247 max_packet_size
= (1 /* Tag 3 identifier */
2248 + 3 /* Max Tag 3 packet size */
2250 + 1 /* Cipher code */
2251 + 1 /* S2K specifier */
2252 + 1 /* Hash identifier */
2253 + ECRYPTFS_SALT_SIZE
/* Salt */
2254 + 1 /* Hash iterations */
2255 + key_rec
->enc_key_size
); /* Encrypted key size */
2256 if (max_packet_size
> (*remaining_bytes
)) {
2257 printk(KERN_ERR
"Packet too large; need up to [%td] bytes, but "
2258 "there are only [%td] available\n", max_packet_size
,
2259 (*remaining_bytes
));
2263 dest
[(*packet_size
)++] = ECRYPTFS_TAG_3_PACKET_TYPE
;
2264 /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3)
2265 * to get the number of octets in the actual Tag 3 packet */
2266 rc
= ecryptfs_write_packet_length(&dest
[(*packet_size
)],
2267 (max_packet_size
- 4),
2268 &packet_size_length
);
2270 printk(KERN_ERR
"Error generating tag 3 packet header; cannot "
2271 "generate packet length. rc = [%d]\n", rc
);
2274 (*packet_size
) += packet_size_length
;
2275 dest
[(*packet_size
)++] = 0x04; /* version 4 */
2276 /* TODO: Break from RFC2440 so that arbitrary ciphers can be
2277 * specified with strings */
2278 cipher_code
= ecryptfs_code_for_cipher_string(crypt_stat
->cipher
,
2279 crypt_stat
->key_size
);
2280 if (cipher_code
== 0) {
2281 ecryptfs_printk(KERN_WARNING
, "Unable to generate code for "
2282 "cipher [%s]\n", crypt_stat
->cipher
);
2286 dest
[(*packet_size
)++] = cipher_code
;
2287 dest
[(*packet_size
)++] = 0x03; /* S2K */
2288 dest
[(*packet_size
)++] = 0x01; /* MD5 (TODO: parameterize) */
2289 memcpy(&dest
[(*packet_size
)], auth_tok
->token
.password
.salt
,
2290 ECRYPTFS_SALT_SIZE
);
2291 (*packet_size
) += ECRYPTFS_SALT_SIZE
; /* salt */
2292 dest
[(*packet_size
)++] = 0x60; /* hash iterations (65536) */
2293 memcpy(&dest
[(*packet_size
)], key_rec
->enc_key
,
2294 key_rec
->enc_key_size
);
2295 (*packet_size
) += key_rec
->enc_key_size
;
2300 (*remaining_bytes
) -= (*packet_size
);
2304 struct kmem_cache
*ecryptfs_key_record_cache
;
2307 * ecryptfs_generate_key_packet_set
2308 * @dest_base: Virtual address from which to write the key record set
2309 * @crypt_stat: The cryptographic context from which the
2310 * authentication tokens will be retrieved
2311 * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat
2312 * for the global parameters
2313 * @len: The amount written
2314 * @max: The maximum amount of data allowed to be written
2316 * Generates a key packet set and writes it to the virtual address
2319 * Returns zero on success; non-zero on error.
2322 ecryptfs_generate_key_packet_set(char *dest_base
,
2323 struct ecryptfs_crypt_stat
*crypt_stat
,
2324 struct dentry
*ecryptfs_dentry
, size_t *len
,
2327 struct ecryptfs_auth_tok
*auth_tok
;
2328 struct ecryptfs_global_auth_tok
*global_auth_tok
;
2329 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
=
2330 &ecryptfs_superblock_to_private(
2331 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
2333 struct ecryptfs_key_record
*key_rec
;
2334 struct ecryptfs_key_sig
*key_sig
;
2338 mutex_lock(&crypt_stat
->keysig_list_mutex
);
2339 key_rec
= kmem_cache_alloc(ecryptfs_key_record_cache
, GFP_KERNEL
);
2344 list_for_each_entry(key_sig
, &crypt_stat
->keysig_list
,
2346 memset(key_rec
, 0, sizeof(*key_rec
));
2347 rc
= ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok
,
2351 printk(KERN_ERR
"Error attempting to get the global "
2352 "auth_tok; rc = [%d]\n", rc
);
2355 if (global_auth_tok
->flags
& ECRYPTFS_AUTH_TOK_INVALID
) {
2357 "Skipping invalid auth tok with sig = [%s]\n",
2358 global_auth_tok
->sig
);
2361 auth_tok
= global_auth_tok
->global_auth_tok
;
2362 if (auth_tok
->token_type
== ECRYPTFS_PASSWORD
) {
2363 rc
= write_tag_3_packet((dest_base
+ (*len
)),
2365 crypt_stat
, key_rec
,
2368 ecryptfs_printk(KERN_WARNING
, "Error "
2369 "writing tag 3 packet\n");
2373 /* Write auth tok signature packet */
2374 rc
= write_tag_11_packet((dest_base
+ (*len
)), &max
,
2376 ECRYPTFS_SIG_SIZE
, &written
);
2378 ecryptfs_printk(KERN_ERR
, "Error writing "
2379 "auth tok signature packet\n");
2383 } else if (auth_tok
->token_type
== ECRYPTFS_PRIVATE_KEY
) {
2384 rc
= write_tag_1_packet(dest_base
+ (*len
),
2386 crypt_stat
, key_rec
, &written
);
2388 ecryptfs_printk(KERN_WARNING
, "Error "
2389 "writing tag 1 packet\n");
2394 ecryptfs_printk(KERN_WARNING
, "Unsupported "
2395 "authentication token type\n");
2400 if (likely(max
> 0)) {
2401 dest_base
[(*len
)] = 0x00;
2403 ecryptfs_printk(KERN_ERR
, "Error writing boundary byte\n");
2407 kmem_cache_free(ecryptfs_key_record_cache
, key_rec
);
2411 mutex_unlock(&crypt_stat
->keysig_list_mutex
);
2415 struct kmem_cache
*ecryptfs_key_sig_cache
;
2417 int ecryptfs_add_keysig(struct ecryptfs_crypt_stat
*crypt_stat
, char *sig
)
2419 struct ecryptfs_key_sig
*new_key_sig
;
2421 new_key_sig
= kmem_cache_alloc(ecryptfs_key_sig_cache
, GFP_KERNEL
);
2424 "Error allocating from ecryptfs_key_sig_cache\n");
2427 memcpy(new_key_sig
->keysig
, sig
, ECRYPTFS_SIG_SIZE_HEX
);
2428 new_key_sig
->keysig
[ECRYPTFS_SIG_SIZE_HEX
] = '\0';
2429 /* Caller must hold keysig_list_mutex */
2430 list_add(&new_key_sig
->crypt_stat_list
, &crypt_stat
->keysig_list
);
2435 struct kmem_cache
*ecryptfs_global_auth_tok_cache
;
2438 ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
,
2439 char *sig
, u32 global_auth_tok_flags
)
2441 struct ecryptfs_global_auth_tok
*new_auth_tok
;
2444 new_auth_tok
= kmem_cache_zalloc(ecryptfs_global_auth_tok_cache
,
2446 if (!new_auth_tok
) {
2448 printk(KERN_ERR
"Error allocating from "
2449 "ecryptfs_global_auth_tok_cache\n");
2452 memcpy(new_auth_tok
->sig
, sig
, ECRYPTFS_SIG_SIZE_HEX
);
2453 new_auth_tok
->flags
= global_auth_tok_flags
;
2454 new_auth_tok
->sig
[ECRYPTFS_SIG_SIZE_HEX
] = '\0';
2455 mutex_lock(&mount_crypt_stat
->global_auth_tok_list_mutex
);
2456 list_add(&new_auth_tok
->mount_crypt_stat_list
,
2457 &mount_crypt_stat
->global_auth_tok_list
);
2458 mutex_unlock(&mount_crypt_stat
->global_auth_tok_list_mutex
);