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headers_check fix: powerpc, elf.h
[linux-2.6/mini2440.git] / fs / ecryptfs / keystore.c
blobff539420cc6f0f4f319bd37ebe82123ae3c691d2
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 memset(s->block_aligned_filename, 0, s->block_aligned_filename_size);
744 kfree(s->block_aligned_filename);
745 out_unlock:
746 mutex_unlock(s->tfm_mutex);
747 out:
748 kfree(s);
749 return rc;
750 }
751
752 struct ecryptfs_parse_tag_70_packet_silly_stack {
753 u8 cipher_code;
754 size_t max_packet_size;
755 size_t packet_size_len;
756 size_t parsed_tag_70_packet_size;
757 size_t block_aligned_filename_size;
758 size_t block_size;
759 size_t i;
760 struct mutex *tfm_mutex;
761 char *decrypted_filename;
762 struct ecryptfs_auth_tok *auth_tok;
763 struct scatterlist src_sg;
764 struct scatterlist dst_sg;
765 struct blkcipher_desc desc;
766 char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1];
767 char iv[ECRYPTFS_MAX_IV_BYTES];
768 char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE];
769 };
770
771 /**
772 * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet
773 * @filename: This function kmalloc's the memory for the filename
774 * @filename_size: This function sets this to the amount of memory
775 * kmalloc'd for the filename
776 * @packet_size: This function sets this to the the number of octets
777 * in the packet parsed
778 * @mount_crypt_stat: The mount-wide cryptographic context
779 * @data: The memory location containing the start of the tag 70
780 * packet
781 * @max_packet_size: The maximum legal size of the packet to be parsed
782 * from @data
783 *
784 * Returns zero on success; non-zero otherwise
785 */
786 int
787 ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
788 size_t *packet_size,
789 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
790 char *data, size_t max_packet_size)
791 {
792 struct ecryptfs_parse_tag_70_packet_silly_stack *s;
793 int rc = 0;
794
795 (*packet_size) = 0;
796 (*filename_size) = 0;
797 (*filename) = NULL;
798 s = kmalloc(sizeof(*s), GFP_KERNEL);
799 if (!s) {
800 printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc "
801 "[%zd] bytes of kernel memory\n", __func__, sizeof(*s));
802 goto out;
803 }
804 s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
805 if (max_packet_size < (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)) {
806 printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be "
807 "at least [%d]\n", __func__, max_packet_size,
808 (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1));
809 rc = -EINVAL;
810 goto out;
811 }
812 /* Octet 0: Tag 70 identifier
813 * Octets 1-N1: Tag 70 packet size (includes cipher identifier
814 * and block-aligned encrypted filename size)
815 * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE)
816 * Octet N2-N3: Cipher identifier (1 octet)
817 * Octets N3-N4: Block-aligned encrypted filename
818 * - Consists of a minimum number of random numbers, a \0
819 * separator, and then the filename */
820 if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) {
821 printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be "
822 "tag [0x%.2x]\n", __func__,
823 data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE);
824 rc = -EINVAL;
825 goto out;
826 }
827 rc = ecryptfs_parse_packet_length(&data[(*packet_size)],
828 &s->parsed_tag_70_packet_size,
829 &s->packet_size_len);
830 if (rc) {
831 printk(KERN_WARNING "%s: Error parsing packet length; "
832 "rc = [%d]\n", __func__, rc);
833 goto out;
834 }
835 s->block_aligned_filename_size = (s->parsed_tag_70_packet_size
836 - ECRYPTFS_SIG_SIZE - 1);
837 if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size)
838 > max_packet_size) {
839 printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet "
840 "size is [%zd]\n", __func__, max_packet_size,
841 (1 + s->packet_size_len + 1
842 + s->block_aligned_filename_size));
843 rc = -EINVAL;
844 goto out;
845 }
846 (*packet_size) += s->packet_size_len;
847 ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)],
848 ECRYPTFS_SIG_SIZE);
849 s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0';
850 (*packet_size) += ECRYPTFS_SIG_SIZE;
851 s->cipher_code = data[(*packet_size)++];
852 rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code);
853 if (rc) {
854 printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n",
855 __func__, s->cipher_code);
856 goto out;
857 }
858 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm,
859 &s->tfm_mutex,
860 s->cipher_string);
861 if (unlikely(rc)) {
862 printk(KERN_ERR "Internal error whilst attempting to get "
863 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
864 s->cipher_string, rc);
865 goto out;
866 }
867 mutex_lock(s->tfm_mutex);
868 rc = virt_to_scatterlist(&data[(*packet_size)],
869 s->block_aligned_filename_size, &s->src_sg, 1);
870 if (rc != 1) {
871 printk(KERN_ERR "%s: Internal error whilst attempting to "
872 "convert encrypted filename memory to scatterlist; "
873 "expected rc = 1; got rc = [%d]. "
874 "block_aligned_filename_size = [%zd]\n", __func__, rc,
875 s->block_aligned_filename_size);
876 goto out_unlock;
877 }
878 (*packet_size) += s->block_aligned_filename_size;
879 s->decrypted_filename = kmalloc(s->block_aligned_filename_size,
880 GFP_KERNEL);
881 if (!s->decrypted_filename) {
882 printk(KERN_ERR "%s: Out of memory whilst attempting to "
883 "kmalloc [%zd] bytes\n", __func__,
884 s->block_aligned_filename_size);
885 rc = -ENOMEM;
886 goto out_unlock;
887 }
888 rc = virt_to_scatterlist(s->decrypted_filename,
889 s->block_aligned_filename_size, &s->dst_sg, 1);
890 if (rc != 1) {
891 printk(KERN_ERR "%s: Internal error whilst attempting to "
892 "convert decrypted filename memory to scatterlist; "
893 "expected rc = 1; got rc = [%d]. "
894 "block_aligned_filename_size = [%zd]\n", __func__, rc,
895 s->block_aligned_filename_size);
896 goto out_free_unlock;
897 }
898 /* The characters in the first block effectively do the job of
899 * the IV here, so we just use 0's for the IV. Note the
900 * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES
901 * >= ECRYPTFS_MAX_IV_BYTES. */
902 memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES);
903 s->desc.info = s->iv;
904 rc = ecryptfs_find_auth_tok_for_sig(&s->auth_tok, mount_crypt_stat,
905 s->fnek_sig_hex);
906 if (rc) {
907 printk(KERN_ERR "%s: Error attempting to find auth tok for "
908 "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex,
909 rc);
910 goto out_free_unlock;
911 }
912 /* TODO: Support other key modules than passphrase for
913 * filename encryption */
914 BUG_ON(s->auth_tok->token_type != ECRYPTFS_PASSWORD);
915 rc = crypto_blkcipher_setkey(
916 s->desc.tfm,
917 s->auth_tok->token.password.session_key_encryption_key,
918 mount_crypt_stat->global_default_fn_cipher_key_bytes);
919 if (rc < 0) {
920 printk(KERN_ERR "%s: Error setting key for crypto context; "
921 "rc = [%d]. s->auth_tok->token.password.session_key_"
922 "encryption_key = [0x%p]; mount_crypt_stat->"
923 "global_default_fn_cipher_key_bytes = [%zd]\n", __func__,
924 rc,
925 s->auth_tok->token.password.session_key_encryption_key,
926 mount_crypt_stat->global_default_fn_cipher_key_bytes);
927 goto out_free_unlock;
928 }
929 rc = crypto_blkcipher_decrypt_iv(&s->desc, &s->dst_sg, &s->src_sg,
930 s->block_aligned_filename_size);
931 if (rc) {
932 printk(KERN_ERR "%s: Error attempting to decrypt filename; "
933 "rc = [%d]\n", __func__, rc);
934 goto out_free_unlock;
935 }
936 s->i = 0;
937 while (s->decrypted_filename[s->i] != '\0'
938 && s->i < s->block_aligned_filename_size)
939 s->i++;
940 if (s->i == s->block_aligned_filename_size) {
941 printk(KERN_WARNING "%s: Invalid tag 70 packet; could not "
942 "find valid separator between random characters and "
943 "the filename\n", __func__);
944 rc = -EINVAL;
945 goto out_free_unlock;
946 }
947 s->i++;
948 (*filename_size) = (s->block_aligned_filename_size - s->i);
949 if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) {
950 printk(KERN_WARNING "%s: Filename size is [%zd], which is "
951 "invalid\n", __func__, (*filename_size));
952 rc = -EINVAL;
953 goto out_free_unlock;
954 }
955 (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL);
956 if (!(*filename)) {
957 printk(KERN_ERR "%s: Out of memory whilst attempting to "
958 "kmalloc [%zd] bytes\n", __func__,
959 ((*filename_size) + 1));
960 rc = -ENOMEM;
961 goto out_free_unlock;
962 }
963 memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size));
964 (*filename)[(*filename_size)] = '\0';
965 out_free_unlock:
966 kfree(s->decrypted_filename);
967 out_unlock:
968 mutex_unlock(s->tfm_mutex);
969 out:
970 if (rc) {
971 (*packet_size) = 0;
972 (*filename_size) = 0;
973 (*filename) = NULL;
974 }
975 kfree(s);
976 return rc;
977 }
978
979 static int
980 ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok)
981 {
982 int rc = 0;
983
984 (*sig) = NULL;
985 switch (auth_tok->token_type) {
986 case ECRYPTFS_PASSWORD:
987 (*sig) = auth_tok->token.password.signature;
988 break;
989 case ECRYPTFS_PRIVATE_KEY:
990 (*sig) = auth_tok->token.private_key.signature;
991 break;
992 default:
993 printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n",
994 auth_tok->token_type);
995 rc = -EINVAL;
996 }
997 return rc;
998 }
999
1000 /**
1001 * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok.
1002 * @auth_tok: The key authentication token used to decrypt the session key
1003 * @crypt_stat: The cryptographic context
1004 *
1005 * Returns zero on success; non-zero error otherwise.
1006 */
1007 static int
1008 decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1009 struct ecryptfs_crypt_stat *crypt_stat)
1010 {
1011 u8 cipher_code = 0;
1012 struct ecryptfs_msg_ctx *msg_ctx;
1013 struct ecryptfs_message *msg = NULL;
1014 char *auth_tok_sig;
1015 char *payload;
1016 size_t payload_len;
1017 int rc;
1018
1019 rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok);
1020 if (rc) {
1021 printk(KERN_ERR "Unrecognized auth tok type: [%d]\n",
1022 auth_tok->token_type);
1023 goto out;
1024 }
1025 rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key),
1026 &payload, &payload_len);
1027 if (rc) {
1028 ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n");
1029 goto out;
1030 }
1031 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
1032 if (rc) {
1033 ecryptfs_printk(KERN_ERR, "Error sending message to "
1034 "ecryptfsd\n");
1035 goto out;
1036 }
1037 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1038 if (rc) {
1039 ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet "
1040 "from the user space daemon\n");
1041 rc = -EIO;
1042 goto out;
1043 }
1044 rc = parse_tag_65_packet(&(auth_tok->session_key),
1045 &cipher_code, msg);
1046 if (rc) {
1047 printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n",
1048 rc);
1049 goto out;
1050 }
1051 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1052 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1053 auth_tok->session_key.decrypted_key_size);
1054 crypt_stat->key_size = auth_tok->session_key.decrypted_key_size;
1055 rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code);
1056 if (rc) {
1057 ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n",
1058 cipher_code)
1059 goto out;
1060 }
1061 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1062 if (ecryptfs_verbosity > 0) {
1063 ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n");
1064 ecryptfs_dump_hex(crypt_stat->key,
1065 crypt_stat->key_size);
1066 }
1067 out:
1068 if (msg)
1069 kfree(msg);
1070 return rc;
1071 }
1072
1073 static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
1074 {
1075 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1076 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1077
1078 list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp,
1079 auth_tok_list_head, list) {
1080 list_del(&auth_tok_list_item->list);
1081 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1082 auth_tok_list_item);
1083 }
1084 }
1085
1086 struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
1087
1088 /**
1089 * parse_tag_1_packet
1090 * @crypt_stat: The cryptographic context to modify based on packet contents
1091 * @data: The raw bytes of the packet.
1092 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
1093 * a new authentication token will be placed at the
1094 * end of this list for this packet.
1095 * @new_auth_tok: Pointer to a pointer to memory that this function
1096 * allocates; sets the memory address of the pointer to
1097 * NULL on error. This object is added to the
1098 * auth_tok_list.
1099 * @packet_size: This function writes the size of the parsed packet
1100 * into this memory location; zero on error.
1101 * @max_packet_size: The maximum allowable packet size
1102 *
1103 * Returns zero on success; non-zero on error.
1104 */
1105 static int
1106 parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
1107 unsigned char *data, struct list_head *auth_tok_list,
1108 struct ecryptfs_auth_tok **new_auth_tok,
1109 size_t *packet_size, size_t max_packet_size)
1110 {
1111 size_t body_size;
1112 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1113 size_t length_size;
1114 int rc = 0;
1115
1116 (*packet_size) = 0;
1117 (*new_auth_tok) = NULL;
1118 /**
1119 * This format is inspired by OpenPGP; see RFC 2440
1120 * packet tag 1
1121 *
1122 * Tag 1 identifier (1 byte)
1123 * Max Tag 1 packet size (max 3 bytes)
1124 * Version (1 byte)
1125 * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE)
1126 * Cipher identifier (1 byte)
1127 * Encrypted key size (arbitrary)
1128 *
1129 * 12 bytes minimum packet size
1130 */
1131 if (unlikely(max_packet_size < 12)) {
1132 printk(KERN_ERR "Invalid max packet size; must be >=12\n");
1133 rc = -EINVAL;
1134 goto out;
1135 }
1136 if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) {
1137 printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n",
1138 ECRYPTFS_TAG_1_PACKET_TYPE);
1139 rc = -EINVAL;
1140 goto out;
1141 }
1142 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1143 * at end of function upon failure */
1144 auth_tok_list_item =
1145 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache,
1146 GFP_KERNEL);
1147 if (!auth_tok_list_item) {
1148 printk(KERN_ERR "Unable to allocate memory\n");
1149 rc = -ENOMEM;
1150 goto out;
1151 }
1152 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
1153 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1154 &length_size);
1155 if (rc) {
1156 printk(KERN_WARNING "Error parsing packet length; "
1157 "rc = [%d]\n", rc);
1158 goto out_free;
1159 }
1160 if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) {
1161 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
1162 rc = -EINVAL;
1163 goto out_free;
1164 }
1165 (*packet_size) += length_size;
1166 if (unlikely((*packet_size) + body_size > max_packet_size)) {
1167 printk(KERN_WARNING "Packet size exceeds max\n");
1168 rc = -EINVAL;
1169 goto out_free;
1170 }
1171 if (unlikely(data[(*packet_size)++] != 0x03)) {
1172 printk(KERN_WARNING "Unknown version number [%d]\n",
1173 data[(*packet_size) - 1]);
1174 rc = -EINVAL;
1175 goto out_free;
1176 }
1177 ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
1178 &data[(*packet_size)], ECRYPTFS_SIG_SIZE);
1179 *packet_size += ECRYPTFS_SIG_SIZE;
1180 /* This byte is skipped because the kernel does not need to
1181 * know which public key encryption algorithm was used */
1182 (*packet_size)++;
1183 (*new_auth_tok)->session_key.encrypted_key_size =
1184 body_size - (ECRYPTFS_SIG_SIZE + 2);
1185 if ((*new_auth_tok)->session_key.encrypted_key_size
1186 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
1187 printk(KERN_WARNING "Tag 1 packet contains key larger "
1188 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
1189 rc = -EINVAL;
1190 goto out;
1191 }
1192 memcpy((*new_auth_tok)->session_key.encrypted_key,
1193 &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2)));
1194 (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size;
1195 (*new_auth_tok)->session_key.flags &=
1196 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1197 (*new_auth_tok)->session_key.flags |=
1198 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
1199 (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY;
1200 (*new_auth_tok)->flags = 0;
1201 (*new_auth_tok)->session_key.flags &=
1202 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1203 (*new_auth_tok)->session_key.flags &=
1204 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
1205 list_add(&auth_tok_list_item->list, auth_tok_list);
1206 goto out;
1207 out_free:
1208 (*new_auth_tok) = NULL;
1209 memset(auth_tok_list_item, 0,
1210 sizeof(struct ecryptfs_auth_tok_list_item));
1211 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1212 auth_tok_list_item);
1213 out:
1214 if (rc)
1215 (*packet_size) = 0;
1216 return rc;
1217 }
1218
1219 /**
1220 * parse_tag_3_packet
1221 * @crypt_stat: The cryptographic context to modify based on packet
1222 * contents.
1223 * @data: The raw bytes of the packet.
1224 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
1225 * a new authentication token will be placed at the end
1226 * of this list for this packet.
1227 * @new_auth_tok: Pointer to a pointer to memory that this function
1228 * allocates; sets the memory address of the pointer to
1229 * NULL on error. This object is added to the
1230 * auth_tok_list.
1231 * @packet_size: This function writes the size of the parsed packet
1232 * into this memory location; zero on error.
1233 * @max_packet_size: maximum number of bytes to parse
1234 *
1235 * Returns zero on success; non-zero on error.
1236 */
1237 static int
1238 parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
1239 unsigned char *data, struct list_head *auth_tok_list,
1240 struct ecryptfs_auth_tok **new_auth_tok,
1241 size_t *packet_size, size_t max_packet_size)
1242 {
1243 size_t body_size;
1244 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1245 size_t length_size;
1246 int rc = 0;
1247
1248 (*packet_size) = 0;
1249 (*new_auth_tok) = NULL;
1250 /**
1251 *This format is inspired by OpenPGP; see RFC 2440
1252 * packet tag 3
1253 *
1254 * Tag 3 identifier (1 byte)
1255 * Max Tag 3 packet size (max 3 bytes)
1256 * Version (1 byte)
1257 * Cipher code (1 byte)
1258 * S2K specifier (1 byte)
1259 * Hash identifier (1 byte)
1260 * Salt (ECRYPTFS_SALT_SIZE)
1261 * Hash iterations (1 byte)
1262 * Encrypted key (arbitrary)
1263 *
1264 * (ECRYPTFS_SALT_SIZE + 7) minimum packet size
1265 */
1266 if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) {
1267 printk(KERN_ERR "Max packet size too large\n");
1268 rc = -EINVAL;
1269 goto out;
1270 }
1271 if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) {
1272 printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n",
1273 ECRYPTFS_TAG_3_PACKET_TYPE);
1274 rc = -EINVAL;
1275 goto out;
1276 }
1277 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
1278 * at end of function upon failure */
1279 auth_tok_list_item =
1280 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
1281 if (!auth_tok_list_item) {
1282 printk(KERN_ERR "Unable to allocate memory\n");
1283 rc = -ENOMEM;
1284 goto out;
1285 }
1286 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
1287 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1288 &length_size);
1289 if (rc) {
1290 printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n",
1291 rc);
1292 goto out_free;
1293 }
1294 if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) {
1295 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
1296 rc = -EINVAL;
1297 goto out_free;
1298 }
1299 (*packet_size) += length_size;
1300 if (unlikely((*packet_size) + body_size > max_packet_size)) {
1301 printk(KERN_ERR "Packet size exceeds max\n");
1302 rc = -EINVAL;
1303 goto out_free;
1304 }
1305 (*new_auth_tok)->session_key.encrypted_key_size =
1306 (body_size - (ECRYPTFS_SALT_SIZE + 5));
1307 if (unlikely(data[(*packet_size)++] != 0x04)) {
1308 printk(KERN_WARNING "Unknown version number [%d]\n",
1309 data[(*packet_size) - 1]);
1310 rc = -EINVAL;
1311 goto out_free;
1312 }
1313 ecryptfs_cipher_code_to_string(crypt_stat->cipher,
1314 (u16)data[(*packet_size)]);
1315 /* A little extra work to differentiate among the AES key
1316 * sizes; see RFC2440 */
1317 switch(data[(*packet_size)++]) {
1318 case RFC2440_CIPHER_AES_192:
1319 crypt_stat->key_size = 24;
1320 break;
1321 default:
1322 crypt_stat->key_size =
1323 (*new_auth_tok)->session_key.encrypted_key_size;
1324 }
1325 ecryptfs_init_crypt_ctx(crypt_stat);
1326 if (unlikely(data[(*packet_size)++] != 0x03)) {
1327 printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
1328 rc = -ENOSYS;
1329 goto out_free;
1330 }
1331 /* TODO: finish the hash mapping */
1332 switch (data[(*packet_size)++]) {
1333 case 0x01: /* See RFC2440 for these numbers and their mappings */
1334 /* Choose MD5 */
1335 memcpy((*new_auth_tok)->token.password.salt,
1336 &data[(*packet_size)], ECRYPTFS_SALT_SIZE);
1337 (*packet_size) += ECRYPTFS_SALT_SIZE;
1338 /* This conversion was taken straight from RFC2440 */
1339 (*new_auth_tok)->token.password.hash_iterations =
1340 ((u32) 16 + (data[(*packet_size)] & 15))
1341 << ((data[(*packet_size)] >> 4) + 6);
1342 (*packet_size)++;
1343 /* Friendly reminder:
1344 * (*new_auth_tok)->session_key.encrypted_key_size =
1345 * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */
1346 memcpy((*new_auth_tok)->session_key.encrypted_key,
1347 &data[(*packet_size)],
1348 (*new_auth_tok)->session_key.encrypted_key_size);
1349 (*packet_size) +=
1350 (*new_auth_tok)->session_key.encrypted_key_size;
1351 (*new_auth_tok)->session_key.flags &=
1352 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1353 (*new_auth_tok)->session_key.flags |=
1354 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
1355 (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */
1356 break;
1357 default:
1358 ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: "
1359 "[%d]\n", data[(*packet_size) - 1]);
1360 rc = -ENOSYS;
1361 goto out_free;
1362 }
1363 (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD;
1364 /* TODO: Parametarize; we might actually want userspace to
1365 * decrypt the session key. */
1366 (*new_auth_tok)->session_key.flags &=
1367 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
1368 (*new_auth_tok)->session_key.flags &=
1369 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
1370 list_add(&auth_tok_list_item->list, auth_tok_list);
1371 goto out;
1372 out_free:
1373 (*new_auth_tok) = NULL;
1374 memset(auth_tok_list_item, 0,
1375 sizeof(struct ecryptfs_auth_tok_list_item));
1376 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
1377 auth_tok_list_item);
1378 out:
1379 if (rc)
1380 (*packet_size) = 0;
1381 return rc;
1382 }
1383
1384 /**
1385 * parse_tag_11_packet
1386 * @data: The raw bytes of the packet
1387 * @contents: This function writes the data contents of the literal
1388 * packet into this memory location
1389 * @max_contents_bytes: The maximum number of bytes that this function
1390 * is allowed to write into contents
1391 * @tag_11_contents_size: This function writes the size of the parsed
1392 * contents into this memory location; zero on
1393 * error
1394 * @packet_size: This function writes the size of the parsed packet
1395 * into this memory location; zero on error
1396 * @max_packet_size: maximum number of bytes to parse
1397 *
1398 * Returns zero on success; non-zero on error.
1399 */
1400 static int
1401 parse_tag_11_packet(unsigned char *data, unsigned char *contents,
1402 size_t max_contents_bytes, size_t *tag_11_contents_size,
1403 size_t *packet_size, size_t max_packet_size)
1404 {
1405 size_t body_size;
1406 size_t length_size;
1407 int rc = 0;
1408
1409 (*packet_size) = 0;
1410 (*tag_11_contents_size) = 0;
1411 /* This format is inspired by OpenPGP; see RFC 2440
1412 * packet tag 11
1413 *
1414 * Tag 11 identifier (1 byte)
1415 * Max Tag 11 packet size (max 3 bytes)
1416 * Binary format specifier (1 byte)
1417 * Filename length (1 byte)
1418 * Filename ("_CONSOLE") (8 bytes)
1419 * Modification date (4 bytes)
1420 * Literal data (arbitrary)
1421 *
1422 * We need at least 16 bytes of data for the packet to even be
1423 * valid.
1424 */
1425 if (max_packet_size < 16) {
1426 printk(KERN_ERR "Maximum packet size too small\n");
1427 rc = -EINVAL;
1428 goto out;
1429 }
1430 if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) {
1431 printk(KERN_WARNING "Invalid tag 11 packet format\n");
1432 rc = -EINVAL;
1433 goto out;
1434 }
1435 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
1436 &length_size);
1437 if (rc) {
1438 printk(KERN_WARNING "Invalid tag 11 packet format\n");
1439 goto out;
1440 }
1441 if (body_size < 14) {
1442 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
1443 rc = -EINVAL;
1444 goto out;
1445 }
1446 (*packet_size) += length_size;
1447 (*tag_11_contents_size) = (body_size - 14);
1448 if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) {
1449 printk(KERN_ERR "Packet size exceeds max\n");
1450 rc = -EINVAL;
1451 goto out;
1452 }
1453 if (data[(*packet_size)++] != 0x62) {
1454 printk(KERN_WARNING "Unrecognizable packet\n");
1455 rc = -EINVAL;
1456 goto out;
1457 }
1458 if (data[(*packet_size)++] != 0x08) {
1459 printk(KERN_WARNING "Unrecognizable packet\n");
1460 rc = -EINVAL;
1461 goto out;
1462 }
1463 (*packet_size) += 12; /* Ignore filename and modification date */
1464 memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size));
1465 (*packet_size) += (*tag_11_contents_size);
1466 out:
1467 if (rc) {
1468 (*packet_size) = 0;
1469 (*tag_11_contents_size) = 0;
1470 }
1471 return rc;
1472 }
1473
1474 /**
1475 * ecryptfs_verify_version
1476 * @version: The version number to confirm
1477 *
1478 * Returns zero on good version; non-zero otherwise
1479 */
1480 static int ecryptfs_verify_version(u16 version)
1481 {
1482 int rc = 0;
1483 unsigned char major;
1484 unsigned char minor;
1485
1486 major = ((version >> 8) & 0xFF);
1487 minor = (version & 0xFF);
1488 if (major != ECRYPTFS_VERSION_MAJOR) {
1489 ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
1490 "Expected [%d]; got [%d]\n",
1491 ECRYPTFS_VERSION_MAJOR, major);
1492 rc = -EINVAL;
1493 goto out;
1494 }
1495 if (minor != ECRYPTFS_VERSION_MINOR) {
1496 ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
1497 "Expected [%d]; got [%d]\n",
1498 ECRYPTFS_VERSION_MINOR, minor);
1499 rc = -EINVAL;
1500 goto out;
1501 }
1502 out:
1503 return rc;
1504 }
1505
1506 int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
1507 struct ecryptfs_auth_tok **auth_tok,
1508 char *sig)
1509 {
1510 int rc = 0;
1511
1512 (*auth_tok_key) = request_key(&key_type_user, sig, NULL);
1513 if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
1514 printk(KERN_ERR "Could not find key with description: [%s]\n",
1515 sig);
1516 rc = process_request_key_err(PTR_ERR(*auth_tok_key));
1517 goto out;
1518 }
1519 (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key);
1520 if (ecryptfs_verify_version((*auth_tok)->version)) {
1521 printk(KERN_ERR
1522 "Data structure version mismatch. "
1523 "Userspace tools must match eCryptfs "
1524 "kernel module with major version [%d] "
1525 "and minor version [%d]\n",
1526 ECRYPTFS_VERSION_MAJOR,
1527 ECRYPTFS_VERSION_MINOR);
1528 rc = -EINVAL;
1529 goto out;
1530 }
1531 if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
1532 && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
1533 printk(KERN_ERR "Invalid auth_tok structure "
1534 "returned from key query\n");
1535 rc = -EINVAL;
1536 goto out;
1537 }
1538 out:
1539 return rc;
1540 }
1541
1542 /**
1543 * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok.
1544 * @auth_tok: The passphrase authentication token to use to encrypt the FEK
1545 * @crypt_stat: The cryptographic context
1546 *
1547 * Returns zero on success; non-zero error otherwise
1548 */
1549 static int
1550 decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1551 struct ecryptfs_crypt_stat *crypt_stat)
1552 {
1553 struct scatterlist dst_sg[2];
1554 struct scatterlist src_sg[2];
1555 struct mutex *tfm_mutex;
1556 struct blkcipher_desc desc = {
1557 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
1558 };
1559 int rc = 0;
1560
1561 if (unlikely(ecryptfs_verbosity > 0)) {
1562 ecryptfs_printk(
1563 KERN_DEBUG, "Session key encryption key (size [%d]):\n",
1564 auth_tok->token.password.session_key_encryption_key_bytes);
1565 ecryptfs_dump_hex(
1566 auth_tok->token.password.session_key_encryption_key,
1567 auth_tok->token.password.session_key_encryption_key_bytes);
1568 }
1569 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
1570 crypt_stat->cipher);
1571 if (unlikely(rc)) {
1572 printk(KERN_ERR "Internal error whilst attempting to get "
1573 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1574 crypt_stat->cipher, rc);
1575 goto out;
1576 }
1577 rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
1578 auth_tok->session_key.encrypted_key_size,
1579 src_sg, 2);
1580 if (rc < 1 || rc > 2) {
1581 printk(KERN_ERR "Internal error whilst attempting to convert "
1582 "auth_tok->session_key.encrypted_key to scatterlist; "
1583 "expected rc = 1; got rc = [%d]. "
1584 "auth_tok->session_key.encrypted_key_size = [%d]\n", rc,
1585 auth_tok->session_key.encrypted_key_size);
1586 goto out;
1587 }
1588 auth_tok->session_key.decrypted_key_size =
1589 auth_tok->session_key.encrypted_key_size;
1590 rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key,
1591 auth_tok->session_key.decrypted_key_size,
1592 dst_sg, 2);
1593 if (rc < 1 || rc > 2) {
1594 printk(KERN_ERR "Internal error whilst attempting to convert "
1595 "auth_tok->session_key.decrypted_key to scatterlist; "
1596 "expected rc = 1; got rc = [%d]\n", rc);
1597 goto out;
1598 }
1599 mutex_lock(tfm_mutex);
1600 rc = crypto_blkcipher_setkey(
1601 desc.tfm, auth_tok->token.password.session_key_encryption_key,
1602 crypt_stat->key_size);
1603 if (unlikely(rc < 0)) {
1604 mutex_unlock(tfm_mutex);
1605 printk(KERN_ERR "Error setting key for crypto context\n");
1606 rc = -EINVAL;
1607 goto out;
1608 }
1609 rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg,
1610 auth_tok->session_key.encrypted_key_size);
1611 mutex_unlock(tfm_mutex);
1612 if (unlikely(rc)) {
1613 printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
1614 goto out;
1615 }
1616 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1617 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1618 auth_tok->session_key.decrypted_key_size);
1619 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1620 if (unlikely(ecryptfs_verbosity > 0)) {
1621 ecryptfs_printk(KERN_DEBUG, "FEK of size [%d]:\n",
1622 crypt_stat->key_size);
1623 ecryptfs_dump_hex(crypt_stat->key,
1624 crypt_stat->key_size);
1625 }
1626 out:
1627 return rc;
1628 }
1629
1630 /**
1631 * ecryptfs_parse_packet_set
1632 * @crypt_stat: The cryptographic context
1633 * @src: Virtual address of region of memory containing the packets
1634 * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set
1635 *
1636 * Get crypt_stat to have the file's session key if the requisite key
1637 * is available to decrypt the session key.
1638 *
1639 * Returns Zero if a valid authentication token was retrieved and
1640 * processed; negative value for file not encrypted or for error
1641 * conditions.
1642 */
1643 int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
1644 unsigned char *src,
1645 struct dentry *ecryptfs_dentry)
1646 {
1647 size_t i = 0;
1648 size_t found_auth_tok;
1649 size_t next_packet_is_auth_tok_packet;
1650 struct list_head auth_tok_list;
1651 struct ecryptfs_auth_tok *matching_auth_tok;
1652 struct ecryptfs_auth_tok *candidate_auth_tok;
1653 char *candidate_auth_tok_sig;
1654 size_t packet_size;
1655 struct ecryptfs_auth_tok *new_auth_tok;
1656 unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE];
1657 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1658 size_t tag_11_contents_size;
1659 size_t tag_11_packet_size;
1660 int rc = 0;
1661
1662 INIT_LIST_HEAD(&auth_tok_list);
1663 /* Parse the header to find as many packets as we can; these will be
1664 * added the our &auth_tok_list */
1665 next_packet_is_auth_tok_packet = 1;
1666 while (next_packet_is_auth_tok_packet) {
1667 size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i);
1668
1669 switch (src[i]) {
1670 case ECRYPTFS_TAG_3_PACKET_TYPE:
1671 rc = parse_tag_3_packet(crypt_stat,
1672 (unsigned char *)&src[i],
1673 &auth_tok_list, &new_auth_tok,
1674 &packet_size, max_packet_size);
1675 if (rc) {
1676 ecryptfs_printk(KERN_ERR, "Error parsing "
1677 "tag 3 packet\n");
1678 rc = -EIO;
1679 goto out_wipe_list;
1680 }
1681 i += packet_size;
1682 rc = parse_tag_11_packet((unsigned char *)&src[i],
1683 sig_tmp_space,
1684 ECRYPTFS_SIG_SIZE,
1685 &tag_11_contents_size,
1686 &tag_11_packet_size,
1687 max_packet_size);
1688 if (rc) {
1689 ecryptfs_printk(KERN_ERR, "No valid "
1690 "(ecryptfs-specific) literal "
1691 "packet containing "
1692 "authentication token "
1693 "signature found after "
1694 "tag 3 packet\n");
1695 rc = -EIO;
1696 goto out_wipe_list;
1697 }
1698 i += tag_11_packet_size;
1699 if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) {
1700 ecryptfs_printk(KERN_ERR, "Expected "
1701 "signature of size [%d]; "
1702 "read size [%d]\n",
1703 ECRYPTFS_SIG_SIZE,
1704 tag_11_contents_size);
1705 rc = -EIO;
1706 goto out_wipe_list;
1707 }
1708 ecryptfs_to_hex(new_auth_tok->token.password.signature,
1709 sig_tmp_space, tag_11_contents_size);
1710 new_auth_tok->token.password.signature[
1711 ECRYPTFS_PASSWORD_SIG_SIZE] = '\0';
1712 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
1713 break;
1714 case ECRYPTFS_TAG_1_PACKET_TYPE:
1715 rc = parse_tag_1_packet(crypt_stat,
1716 (unsigned char *)&src[i],
1717 &auth_tok_list, &new_auth_tok,
1718 &packet_size, max_packet_size);
1719 if (rc) {
1720 ecryptfs_printk(KERN_ERR, "Error parsing "
1721 "tag 1 packet\n");
1722 rc = -EIO;
1723 goto out_wipe_list;
1724 }
1725 i += packet_size;
1726 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
1727 break;
1728 case ECRYPTFS_TAG_11_PACKET_TYPE:
1729 ecryptfs_printk(KERN_WARNING, "Invalid packet set "
1730 "(Tag 11 not allowed by itself)\n");
1731 rc = -EIO;
1732 goto out_wipe_list;
1733 break;
1734 default:
1735 ecryptfs_printk(KERN_DEBUG, "No packet at offset "
1736 "[%d] of the file header; hex value of "
1737 "character is [0x%.2x]\n", i, src[i]);
1738 next_packet_is_auth_tok_packet = 0;
1739 }
1740 }
1741 if (list_empty(&auth_tok_list)) {
1742 printk(KERN_ERR "The lower file appears to be a non-encrypted "
1743 "eCryptfs file; this is not supported in this version "
1744 "of the eCryptfs kernel module\n");
1745 rc = -EINVAL;
1746 goto out;
1747 }
1748 /* auth_tok_list contains the set of authentication tokens
1749 * parsed from the metadata. We need to find a matching
1750 * authentication token that has the secret component(s)
1751 * necessary to decrypt the EFEK in the auth_tok parsed from
1752 * the metadata. There may be several potential matches, but
1753 * just one will be sufficient to decrypt to get the FEK. */
1754 find_next_matching_auth_tok:
1755 found_auth_tok = 0;
1756 list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) {
1757 candidate_auth_tok = &auth_tok_list_item->auth_tok;
1758 if (unlikely(ecryptfs_verbosity > 0)) {
1759 ecryptfs_printk(KERN_DEBUG,
1760 "Considering cadidate auth tok:\n");
1761 ecryptfs_dump_auth_tok(candidate_auth_tok);
1762 }
1763 rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig,
1764 candidate_auth_tok);
1765 if (rc) {
1766 printk(KERN_ERR
1767 "Unrecognized candidate auth tok type: [%d]\n",
1768 candidate_auth_tok->token_type);
1769 rc = -EINVAL;
1770 goto out_wipe_list;
1771 }
1772 ecryptfs_find_auth_tok_for_sig(&matching_auth_tok,
1773 crypt_stat->mount_crypt_stat,
1774 candidate_auth_tok_sig);
1775 if (matching_auth_tok) {
1776 found_auth_tok = 1;
1777 goto found_matching_auth_tok;
1778 }
1779 }
1780 if (!found_auth_tok) {
1781 ecryptfs_printk(KERN_ERR, "Could not find a usable "
1782 "authentication token\n");
1783 rc = -EIO;
1784 goto out_wipe_list;
1785 }
1786 found_matching_auth_tok:
1787 if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
1788 memcpy(&(candidate_auth_tok->token.private_key),
1789 &(matching_auth_tok->token.private_key),
1790 sizeof(struct ecryptfs_private_key));
1791 rc = decrypt_pki_encrypted_session_key(candidate_auth_tok,
1792 crypt_stat);
1793 } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
1794 memcpy(&(candidate_auth_tok->token.password),
1795 &(matching_auth_tok->token.password),
1796 sizeof(struct ecryptfs_password));
1797 rc = decrypt_passphrase_encrypted_session_key(
1798 candidate_auth_tok, crypt_stat);
1799 }
1800 if (rc) {
1801 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1802
1803 ecryptfs_printk(KERN_WARNING, "Error decrypting the "
1804 "session key for authentication token with sig "
1805 "[%.*s]; rc = [%d]. Removing auth tok "
1806 "candidate from the list and searching for "
1807 "the next match.\n", candidate_auth_tok_sig,
1808 ECRYPTFS_SIG_SIZE_HEX, rc);
1809 list_for_each_entry_safe(auth_tok_list_item,
1810 auth_tok_list_item_tmp,
1811 &auth_tok_list, list) {
1812 if (candidate_auth_tok
1813 == &auth_tok_list_item->auth_tok) {
1814 list_del(&auth_tok_list_item->list);
1815 kmem_cache_free(
1816 ecryptfs_auth_tok_list_item_cache,
1817 auth_tok_list_item);
1818 goto find_next_matching_auth_tok;
1819 }
1820 }
1821 BUG();
1822 }
1823 rc = ecryptfs_compute_root_iv(crypt_stat);
1824 if (rc) {
1825 ecryptfs_printk(KERN_ERR, "Error computing "
1826 "the root IV\n");
1827 goto out_wipe_list;
1828 }
1829 rc = ecryptfs_init_crypt_ctx(crypt_stat);
1830 if (rc) {
1831 ecryptfs_printk(KERN_ERR, "Error initializing crypto "
1832 "context for cipher [%s]; rc = [%d]\n",
1833 crypt_stat->cipher, rc);
1834 }
1835 out_wipe_list:
1836 wipe_auth_tok_list(&auth_tok_list);
1837 out:
1838 return rc;
1839 }
1840
1841 static int
1842 pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
1843 struct ecryptfs_crypt_stat *crypt_stat,
1844 struct ecryptfs_key_record *key_rec)
1845 {
1846 struct ecryptfs_msg_ctx *msg_ctx = NULL;
1847 char *payload = NULL;
1848 size_t payload_len;
1849 struct ecryptfs_message *msg;
1850 int rc;
1851
1852 rc = write_tag_66_packet(auth_tok->token.private_key.signature,
1853 ecryptfs_code_for_cipher_string(
1854 crypt_stat->cipher,
1855 crypt_stat->key_size),
1856 crypt_stat, &payload, &payload_len);
1857 if (rc) {
1858 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
1859 goto out;
1860 }
1861 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
1862 if (rc) {
1863 ecryptfs_printk(KERN_ERR, "Error sending message to "
1864 "ecryptfsd\n");
1865 goto out;
1866 }
1867 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1868 if (rc) {
1869 ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet "
1870 "from the user space daemon\n");
1871 rc = -EIO;
1872 goto out;
1873 }
1874 rc = parse_tag_67_packet(key_rec, msg);
1875 if (rc)
1876 ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n");
1877 kfree(msg);
1878 out:
1879 kfree(payload);
1880 return rc;
1881 }
1882 /**
1883 * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet
1884 * @dest: Buffer into which to write the packet
1885 * @remaining_bytes: Maximum number of bytes that can be writtn
1886 * @auth_tok: The authentication token used for generating the tag 1 packet
1887 * @crypt_stat: The cryptographic context
1888 * @key_rec: The key record struct for the tag 1 packet
1889 * @packet_size: This function will write the number of bytes that end
1890 * up constituting the packet; set to zero on error
1891 *
1892 * Returns zero on success; non-zero on error.
1893 */
1894 static int
1895 write_tag_1_packet(char *dest, size_t *remaining_bytes,
1896 struct ecryptfs_auth_tok *auth_tok,
1897 struct ecryptfs_crypt_stat *crypt_stat,
1898 struct ecryptfs_key_record *key_rec, size_t *packet_size)
1899 {
1900 size_t i;
1901 size_t encrypted_session_key_valid = 0;
1902 size_t packet_size_length;
1903 size_t max_packet_size;
1904 int rc = 0;
1905
1906 (*packet_size) = 0;
1907 ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature,
1908 ECRYPTFS_SIG_SIZE);
1909 encrypted_session_key_valid = 0;
1910 for (i = 0; i < crypt_stat->key_size; i++)
1911 encrypted_session_key_valid |=
1912 auth_tok->session_key.encrypted_key[i];
1913 if (encrypted_session_key_valid) {
1914 memcpy(key_rec->enc_key,
1915 auth_tok->session_key.encrypted_key,
1916 auth_tok->session_key.encrypted_key_size);
1917 goto encrypted_session_key_set;
1918 }
1919 if (auth_tok->session_key.encrypted_key_size == 0)
1920 auth_tok->session_key.encrypted_key_size =
1921 auth_tok->token.private_key.key_size;
1922 rc = pki_encrypt_session_key(auth_tok, crypt_stat, key_rec);
1923 if (rc) {
1924 printk(KERN_ERR "Failed to encrypt session key via a key "
1925 "module; rc = [%d]\n", rc);
1926 goto out;
1927 }
1928 if (ecryptfs_verbosity > 0) {
1929 ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n");
1930 ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size);
1931 }
1932 encrypted_session_key_set:
1933 /* This format is inspired by OpenPGP; see RFC 2440
1934 * packet tag 1 */
1935 max_packet_size = (1 /* Tag 1 identifier */
1936 + 3 /* Max Tag 1 packet size */
1937 + 1 /* Version */
1938 + ECRYPTFS_SIG_SIZE /* Key identifier */
1939 + 1 /* Cipher identifier */
1940 + key_rec->enc_key_size); /* Encrypted key size */
1941 if (max_packet_size > (*remaining_bytes)) {
1942 printk(KERN_ERR "Packet length larger than maximum allowable; "
1943 "need up to [%td] bytes, but there are only [%td] "
1944 "available\n", max_packet_size, (*remaining_bytes));
1945 rc = -EINVAL;
1946 goto out;
1947 }
1948 dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE;
1949 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
1950 (max_packet_size - 4),
1951 &packet_size_length);
1952 if (rc) {
1953 ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet "
1954 "header; cannot generate packet length\n");
1955 goto out;
1956 }
1957 (*packet_size) += packet_size_length;
1958 dest[(*packet_size)++] = 0x03; /* version 3 */
1959 memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE);
1960 (*packet_size) += ECRYPTFS_SIG_SIZE;
1961 dest[(*packet_size)++] = RFC2440_CIPHER_RSA;
1962 memcpy(&dest[(*packet_size)], key_rec->enc_key,
1963 key_rec->enc_key_size);
1964 (*packet_size) += key_rec->enc_key_size;
1965 out:
1966 if (rc)
1967 (*packet_size) = 0;
1968 else
1969 (*remaining_bytes) -= (*packet_size);
1970 return rc;
1971 }
1972
1973 /**
1974 * write_tag_11_packet
1975 * @dest: Target into which Tag 11 packet is to be written
1976 * @remaining_bytes: Maximum packet length
1977 * @contents: Byte array of contents to copy in
1978 * @contents_length: Number of bytes in contents
1979 * @packet_length: Length of the Tag 11 packet written; zero on error
1980 *
1981 * Returns zero on success; non-zero on error.
1982 */
1983 static int
1984 write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents,
1985 size_t contents_length, size_t *packet_length)
1986 {
1987 size_t packet_size_length;
1988 size_t max_packet_size;
1989 int rc = 0;
1990
1991 (*packet_length) = 0;
1992 /* This format is inspired by OpenPGP; see RFC 2440
1993 * packet tag 11 */
1994 max_packet_size = (1 /* Tag 11 identifier */
1995 + 3 /* Max Tag 11 packet size */
1996 + 1 /* Binary format specifier */
1997 + 1 /* Filename length */
1998 + 8 /* Filename ("_CONSOLE") */
1999 + 4 /* Modification date */
2000 + contents_length); /* Literal data */
2001 if (max_packet_size > (*remaining_bytes)) {
2002 printk(KERN_ERR "Packet length larger than maximum allowable; "
2003 "need up to [%td] bytes, but there are only [%td] "
2004 "available\n", max_packet_size, (*remaining_bytes));
2005 rc = -EINVAL;
2006 goto out;
2007 }
2008 dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE;
2009 rc = ecryptfs_write_packet_length(&dest[(*packet_length)],
2010 (max_packet_size - 4),
2011 &packet_size_length);
2012 if (rc) {
2013 printk(KERN_ERR "Error generating tag 11 packet header; cannot "
2014 "generate packet length. rc = [%d]\n", rc);
2015 goto out;
2016 }
2017 (*packet_length) += packet_size_length;
2018 dest[(*packet_length)++] = 0x62; /* binary data format specifier */
2019 dest[(*packet_length)++] = 8;
2020 memcpy(&dest[(*packet_length)], "_CONSOLE", 8);
2021 (*packet_length) += 8;
2022 memset(&dest[(*packet_length)], 0x00, 4);
2023 (*packet_length) += 4;
2024 memcpy(&dest[(*packet_length)], contents, contents_length);
2025 (*packet_length) += contents_length;
2026 out:
2027 if (rc)
2028 (*packet_length) = 0;
2029 else
2030 (*remaining_bytes) -= (*packet_length);
2031 return rc;
2032 }
2033
2034 /**
2035 * write_tag_3_packet
2036 * @dest: Buffer into which to write the packet
2037 * @remaining_bytes: Maximum number of bytes that can be written
2038 * @auth_tok: Authentication token
2039 * @crypt_stat: The cryptographic context
2040 * @key_rec: encrypted key
2041 * @packet_size: This function will write the number of bytes that end
2042 * up constituting the packet; set to zero on error
2043 *
2044 * Returns zero on success; non-zero on error.
2045 */
2046 static int
2047 write_tag_3_packet(char *dest, size_t *remaining_bytes,
2048 struct ecryptfs_auth_tok *auth_tok,
2049 struct ecryptfs_crypt_stat *crypt_stat,
2050 struct ecryptfs_key_record *key_rec, size_t *packet_size)
2051 {
2052 size_t i;
2053 size_t encrypted_session_key_valid = 0;
2054 char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
2055 struct scatterlist dst_sg[2];
2056 struct scatterlist src_sg[2];
2057 struct mutex *tfm_mutex = NULL;
2058 u8 cipher_code;
2059 size_t packet_size_length;
2060 size_t max_packet_size;
2061 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2062 crypt_stat->mount_crypt_stat;
2063 struct blkcipher_desc desc = {
2064 .tfm = NULL,
2065 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
2066 };
2067 int rc = 0;
2068
2069 (*packet_size) = 0;
2070 ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
2071 ECRYPTFS_SIG_SIZE);
2072 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
2073 crypt_stat->cipher);
2074 if (unlikely(rc)) {
2075 printk(KERN_ERR "Internal error whilst attempting to get "
2076 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
2077 crypt_stat->cipher, rc);
2078 goto out;
2079 }
2080 if (mount_crypt_stat->global_default_cipher_key_size == 0) {
2081 struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm);
2082
2083 printk(KERN_WARNING "No key size specified at mount; "
2084 "defaulting to [%d]\n", alg->max_keysize);
2085 mount_crypt_stat->global_default_cipher_key_size =
2086 alg->max_keysize;
2087 }
2088 if (crypt_stat->key_size == 0)
2089 crypt_stat->key_size =
2090 mount_crypt_stat->global_default_cipher_key_size;
2091 if (auth_tok->session_key.encrypted_key_size == 0)
2092 auth_tok->session_key.encrypted_key_size =
2093 crypt_stat->key_size;
2094 if (crypt_stat->key_size == 24
2095 && strcmp("aes", crypt_stat->cipher) == 0) {
2096 memset((crypt_stat->key + 24), 0, 8);
2097 auth_tok->session_key.encrypted_key_size = 32;
2098 } else
2099 auth_tok->session_key.encrypted_key_size = crypt_stat->key_size;
2100 key_rec->enc_key_size =
2101 auth_tok->session_key.encrypted_key_size;
2102 encrypted_session_key_valid = 0;
2103 for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++)
2104 encrypted_session_key_valid |=
2105 auth_tok->session_key.encrypted_key[i];
2106 if (encrypted_session_key_valid) {
2107 ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; "
2108 "using auth_tok->session_key.encrypted_key, "
2109 "where key_rec->enc_key_size = [%d]\n",
2110 key_rec->enc_key_size);
2111 memcpy(key_rec->enc_key,
2112 auth_tok->session_key.encrypted_key,
2113 key_rec->enc_key_size);
2114 goto encrypted_session_key_set;
2115 }
2116 if (auth_tok->token.password.flags &
2117 ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) {
2118 ecryptfs_printk(KERN_DEBUG, "Using previously generated "
2119 "session key encryption key of size [%d]\n",
2120 auth_tok->token.password.
2121 session_key_encryption_key_bytes);
2122 memcpy(session_key_encryption_key,
2123 auth_tok->token.password.session_key_encryption_key,
2124 crypt_stat->key_size);
2125 ecryptfs_printk(KERN_DEBUG,
2126 "Cached session key " "encryption key: \n");
2127 if (ecryptfs_verbosity > 0)
2128 ecryptfs_dump_hex(session_key_encryption_key, 16);
2129 }
2130 if (unlikely(ecryptfs_verbosity > 0)) {
2131 ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n");
2132 ecryptfs_dump_hex(session_key_encryption_key, 16);
2133 }
2134 rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size,
2135 src_sg, 2);
2136 if (rc < 1 || rc > 2) {
2137 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
2138 "for crypt_stat session key; expected rc = 1; "
2139 "got rc = [%d]. key_rec->enc_key_size = [%d]\n",
2140 rc, key_rec->enc_key_size);
2141 rc = -ENOMEM;
2142 goto out;
2143 }
2144 rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size,
2145 dst_sg, 2);
2146 if (rc < 1 || rc > 2) {
2147 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
2148 "for crypt_stat encrypted session key; "
2149 "expected rc = 1; got rc = [%d]. "
2150 "key_rec->enc_key_size = [%d]\n", rc,
2151 key_rec->enc_key_size);
2152 rc = -ENOMEM;
2153 goto out;
2154 }
2155 mutex_lock(tfm_mutex);
2156 rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key,
2157 crypt_stat->key_size);
2158 if (rc < 0) {
2159 mutex_unlock(tfm_mutex);
2160 ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
2161 "context; rc = [%d]\n", rc);
2162 goto out;
2163 }
2164 rc = 0;
2165 ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n",
2166 crypt_stat->key_size);
2167 rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg,
2168 (*key_rec).enc_key_size);
2169 mutex_unlock(tfm_mutex);
2170 if (rc) {
2171 printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc);
2172 goto out;
2173 }
2174 ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
2175 if (ecryptfs_verbosity > 0) {
2176 ecryptfs_printk(KERN_DEBUG, "EFEK of size [%d]:\n",
2177 key_rec->enc_key_size);
2178 ecryptfs_dump_hex(key_rec->enc_key,
2179 key_rec->enc_key_size);
2180 }
2181 encrypted_session_key_set:
2182 /* This format is inspired by OpenPGP; see RFC 2440
2183 * packet tag 3 */
2184 max_packet_size = (1 /* Tag 3 identifier */
2185 + 3 /* Max Tag 3 packet size */
2186 + 1 /* Version */
2187 + 1 /* Cipher code */
2188 + 1 /* S2K specifier */
2189 + 1 /* Hash identifier */
2190 + ECRYPTFS_SALT_SIZE /* Salt */
2191 + 1 /* Hash iterations */
2192 + key_rec->enc_key_size); /* Encrypted key size */
2193 if (max_packet_size > (*remaining_bytes)) {
2194 printk(KERN_ERR "Packet too large; need up to [%td] bytes, but "
2195 "there are only [%td] available\n", max_packet_size,
2196 (*remaining_bytes));
2197 rc = -EINVAL;
2198 goto out;
2199 }
2200 dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE;
2201 /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3)
2202 * to get the number of octets in the actual Tag 3 packet */
2203 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
2204 (max_packet_size - 4),
2205 &packet_size_length);
2206 if (rc) {
2207 printk(KERN_ERR "Error generating tag 3 packet header; cannot "
2208 "generate packet length. rc = [%d]\n", rc);
2209 goto out;
2210 }
2211 (*packet_size) += packet_size_length;
2212 dest[(*packet_size)++] = 0x04; /* version 4 */
2213 /* TODO: Break from RFC2440 so that arbitrary ciphers can be
2214 * specified with strings */
2215 cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher,
2216 crypt_stat->key_size);
2217 if (cipher_code == 0) {
2218 ecryptfs_printk(KERN_WARNING, "Unable to generate code for "
2219 "cipher [%s]\n", crypt_stat->cipher);
2220 rc = -EINVAL;
2221 goto out;
2222 }
2223 dest[(*packet_size)++] = cipher_code;
2224 dest[(*packet_size)++] = 0x03; /* S2K */
2225 dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */
2226 memcpy(&dest[(*packet_size)], auth_tok->token.password.salt,
2227 ECRYPTFS_SALT_SIZE);
2228 (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */
2229 dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */
2230 memcpy(&dest[(*packet_size)], key_rec->enc_key,
2231 key_rec->enc_key_size);
2232 (*packet_size) += key_rec->enc_key_size;
2233 out:
2234 if (rc)
2235 (*packet_size) = 0;
2236 else
2237 (*remaining_bytes) -= (*packet_size);
2238 return rc;
2239 }
2240
2241 struct kmem_cache *ecryptfs_key_record_cache;
2242
2243 /**
2244 * ecryptfs_generate_key_packet_set
2245 * @dest_base: Virtual address from which to write the key record set
2246 * @crypt_stat: The cryptographic context from which the
2247 * authentication tokens will be retrieved
2248 * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat
2249 * for the global parameters
2250 * @len: The amount written
2251 * @max: The maximum amount of data allowed to be written
2252 *
2253 * Generates a key packet set and writes it to the virtual address
2254 * passed in.
2255 *
2256 * Returns zero on success; non-zero on error.
2257 */
2258 int
2259 ecryptfs_generate_key_packet_set(char *dest_base,
2260 struct ecryptfs_crypt_stat *crypt_stat,
2261 struct dentry *ecryptfs_dentry, size_t *len,
2262 size_t max)
2263 {
2264 struct ecryptfs_auth_tok *auth_tok;
2265 struct ecryptfs_global_auth_tok *global_auth_tok;
2266 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
2267 &ecryptfs_superblock_to_private(
2268 ecryptfs_dentry->d_sb)->mount_crypt_stat;
2269 size_t written;
2270 struct ecryptfs_key_record *key_rec;
2271 struct ecryptfs_key_sig *key_sig;
2272 int rc = 0;
2273
2274 (*len) = 0;
2275 mutex_lock(&crypt_stat->keysig_list_mutex);
2276 key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL);
2277 if (!key_rec) {
2278 rc = -ENOMEM;
2279 goto out;
2280 }
2281 list_for_each_entry(key_sig, &crypt_stat->keysig_list,
2282 crypt_stat_list) {
2283 memset(key_rec, 0, sizeof(*key_rec));
2284 rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
2285 mount_crypt_stat,
2286 key_sig->keysig);
2287 if (rc) {
2288 printk(KERN_ERR "Error attempting to get the global "
2289 "auth_tok; rc = [%d]\n", rc);
2290 goto out_free;
2291 }
2292 if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) {
2293 printk(KERN_WARNING
2294 "Skipping invalid auth tok with sig = [%s]\n",
2295 global_auth_tok->sig);
2296 continue;
2297 }
2298 auth_tok = global_auth_tok->global_auth_tok;
2299 if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
2300 rc = write_tag_3_packet((dest_base + (*len)),
2301 &max, auth_tok,
2302 crypt_stat, key_rec,
2303 &written);
2304 if (rc) {
2305 ecryptfs_printk(KERN_WARNING, "Error "
2306 "writing tag 3 packet\n");
2307 goto out_free;
2308 }
2309 (*len) += written;
2310 /* Write auth tok signature packet */
2311 rc = write_tag_11_packet((dest_base + (*len)), &max,
2312 key_rec->sig,
2313 ECRYPTFS_SIG_SIZE, &written);
2314 if (rc) {
2315 ecryptfs_printk(KERN_ERR, "Error writing "
2316 "auth tok signature packet\n");
2317 goto out_free;
2318 }
2319 (*len) += written;
2320 } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
2321 rc = write_tag_1_packet(dest_base + (*len),
2322 &max, auth_tok,
2323 crypt_stat, key_rec, &written);
2324 if (rc) {
2325 ecryptfs_printk(KERN_WARNING, "Error "
2326 "writing tag 1 packet\n");
2327 goto out_free;
2328 }
2329 (*len) += written;
2330 } else {
2331 ecryptfs_printk(KERN_WARNING, "Unsupported "
2332 "authentication token type\n");
2333 rc = -EINVAL;
2334 goto out_free;
2335 }
2336 }
2337 if (likely(max > 0)) {
2338 dest_base[(*len)] = 0x00;
2339 } else {
2340 ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n");
2341 rc = -EIO;
2342 }
2343 out_free:
2344 kmem_cache_free(ecryptfs_key_record_cache, key_rec);
2345 out:
2346 if (rc)
2347 (*len) = 0;
2348 mutex_unlock(&crypt_stat->keysig_list_mutex);
2349 return rc;
2350 }
2351
2352 struct kmem_cache *ecryptfs_key_sig_cache;
2353
2354 int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig)
2355 {
2356 struct ecryptfs_key_sig *new_key_sig;
2357 int rc = 0;
2358
2359 new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL);
2360 if (!new_key_sig) {
2361 rc = -ENOMEM;
2362 printk(KERN_ERR
2363 "Error allocating from ecryptfs_key_sig_cache\n");
2364 goto out;
2365 }
2366 memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
2367 mutex_lock(&crypt_stat->keysig_list_mutex);
2368 list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
2369 mutex_unlock(&crypt_stat->keysig_list_mutex);
2370 out:
2371 return rc;
2372 }
2373
2374 struct kmem_cache *ecryptfs_global_auth_tok_cache;
2375
2376 int
2377 ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
2378 char *sig)
2379 {
2380 struct ecryptfs_global_auth_tok *new_auth_tok;
2381 int rc = 0;
2382
2383 new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache,
2384 GFP_KERNEL);
2385 if (!new_auth_tok) {
2386 rc = -ENOMEM;
2387 printk(KERN_ERR "Error allocating from "
2388 "ecryptfs_global_auth_tok_cache\n");
2389 goto out;
2390 }
2391 memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX);
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
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