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add releasepage hooks to block devices which can be used by file systems
[linux-2.6/mini2440.git] / fs / ecryptfs / keystore.c
blob0d713b6919411375b4831c4e8c0f89419dfbd767
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_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok)
407 {
408 int rc = 0;
409
410 (*sig) = NULL;
411 switch (auth_tok->token_type) {
412 case ECRYPTFS_PASSWORD:
413 (*sig) = auth_tok->token.password.signature;
414 break;
415 case ECRYPTFS_PRIVATE_KEY:
416 (*sig) = auth_tok->token.private_key.signature;
417 break;
418 default:
419 printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n",
420 auth_tok->token_type);
421 rc = -EINVAL;
422 }
423 return rc;
424 }
425
426 /**
427 * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok.
428 * @auth_tok: The key authentication token used to decrypt the session key
429 * @crypt_stat: The cryptographic context
430 *
431 * Returns zero on success; non-zero error otherwise.
432 */
433 static int
434 decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
435 struct ecryptfs_crypt_stat *crypt_stat)
436 {
437 u8 cipher_code = 0;
438 struct ecryptfs_msg_ctx *msg_ctx;
439 struct ecryptfs_message *msg = NULL;
440 char *auth_tok_sig;
441 char *payload;
442 size_t payload_len;
443 int rc;
444
445 rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok);
446 if (rc) {
447 printk(KERN_ERR "Unrecognized auth tok type: [%d]\n",
448 auth_tok->token_type);
449 goto out;
450 }
451 rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key),
452 &payload, &payload_len);
453 if (rc) {
454 ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n");
455 goto out;
456 }
457 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
458 if (rc) {
459 ecryptfs_printk(KERN_ERR, "Error sending message to "
460 "ecryptfsd\n");
461 goto out;
462 }
463 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
464 if (rc) {
465 ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet "
466 "from the user space daemon\n");
467 rc = -EIO;
468 goto out;
469 }
470 rc = parse_tag_65_packet(&(auth_tok->session_key),
471 &cipher_code, msg);
472 if (rc) {
473 printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n",
474 rc);
475 goto out;
476 }
477 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
478 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
479 auth_tok->session_key.decrypted_key_size);
480 crypt_stat->key_size = auth_tok->session_key.decrypted_key_size;
481 rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code);
482 if (rc) {
483 ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n",
484 cipher_code)
485 goto out;
486 }
487 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
488 if (ecryptfs_verbosity > 0) {
489 ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n");
490 ecryptfs_dump_hex(crypt_stat->key,
491 crypt_stat->key_size);
492 }
493 out:
494 if (msg)
495 kfree(msg);
496 return rc;
497 }
498
499 static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
500 {
501 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
502 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
503
504 list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp,
505 auth_tok_list_head, list) {
506 list_del(&auth_tok_list_item->list);
507 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
508 auth_tok_list_item);
509 }
510 }
511
512 struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
513
514 /**
515 * parse_tag_1_packet
516 * @crypt_stat: The cryptographic context to modify based on packet contents
517 * @data: The raw bytes of the packet.
518 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
519 * a new authentication token will be placed at the
520 * end of this list for this packet.
521 * @new_auth_tok: Pointer to a pointer to memory that this function
522 * allocates; sets the memory address of the pointer to
523 * NULL on error. This object is added to the
524 * auth_tok_list.
525 * @packet_size: This function writes the size of the parsed packet
526 * into this memory location; zero on error.
527 * @max_packet_size: The maximum allowable packet size
528 *
529 * Returns zero on success; non-zero on error.
530 */
531 static int
532 parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
533 unsigned char *data, struct list_head *auth_tok_list,
534 struct ecryptfs_auth_tok **new_auth_tok,
535 size_t *packet_size, size_t max_packet_size)
536 {
537 size_t body_size;
538 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
539 size_t length_size;
540 int rc = 0;
541
542 (*packet_size) = 0;
543 (*new_auth_tok) = NULL;
544 /**
545 * This format is inspired by OpenPGP; see RFC 2440
546 * packet tag 1
547 *
548 * Tag 1 identifier (1 byte)
549 * Max Tag 1 packet size (max 3 bytes)
550 * Version (1 byte)
551 * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE)
552 * Cipher identifier (1 byte)
553 * Encrypted key size (arbitrary)
554 *
555 * 12 bytes minimum packet size
556 */
557 if (unlikely(max_packet_size < 12)) {
558 printk(KERN_ERR "Invalid max packet size; must be >=12\n");
559 rc = -EINVAL;
560 goto out;
561 }
562 if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) {
563 printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n",
564 ECRYPTFS_TAG_1_PACKET_TYPE);
565 rc = -EINVAL;
566 goto out;
567 }
568 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
569 * at end of function upon failure */
570 auth_tok_list_item =
571 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache,
572 GFP_KERNEL);
573 if (!auth_tok_list_item) {
574 printk(KERN_ERR "Unable to allocate memory\n");
575 rc = -ENOMEM;
576 goto out;
577 }
578 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
579 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
580 &length_size);
581 if (rc) {
582 printk(KERN_WARNING "Error parsing packet length; "
583 "rc = [%d]\n", rc);
584 goto out_free;
585 }
586 if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) {
587 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
588 rc = -EINVAL;
589 goto out_free;
590 }
591 (*packet_size) += length_size;
592 if (unlikely((*packet_size) + body_size > max_packet_size)) {
593 printk(KERN_WARNING "Packet size exceeds max\n");
594 rc = -EINVAL;
595 goto out_free;
596 }
597 if (unlikely(data[(*packet_size)++] != 0x03)) {
598 printk(KERN_WARNING "Unknown version number [%d]\n",
599 data[(*packet_size) - 1]);
600 rc = -EINVAL;
601 goto out_free;
602 }
603 ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
604 &data[(*packet_size)], ECRYPTFS_SIG_SIZE);
605 *packet_size += ECRYPTFS_SIG_SIZE;
606 /* This byte is skipped because the kernel does not need to
607 * know which public key encryption algorithm was used */
608 (*packet_size)++;
609 (*new_auth_tok)->session_key.encrypted_key_size =
610 body_size - (ECRYPTFS_SIG_SIZE + 2);
611 if ((*new_auth_tok)->session_key.encrypted_key_size
612 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
613 printk(KERN_WARNING "Tag 1 packet contains key larger "
614 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
615 rc = -EINVAL;
616 goto out;
617 }
618 memcpy((*new_auth_tok)->session_key.encrypted_key,
619 &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2)));
620 (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size;
621 (*new_auth_tok)->session_key.flags &=
622 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
623 (*new_auth_tok)->session_key.flags |=
624 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
625 (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY;
626 (*new_auth_tok)->flags = 0;
627 (*new_auth_tok)->session_key.flags &=
628 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
629 (*new_auth_tok)->session_key.flags &=
630 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
631 list_add(&auth_tok_list_item->list, auth_tok_list);
632 goto out;
633 out_free:
634 (*new_auth_tok) = NULL;
635 memset(auth_tok_list_item, 0,
636 sizeof(struct ecryptfs_auth_tok_list_item));
637 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
638 auth_tok_list_item);
639 out:
640 if (rc)
641 (*packet_size) = 0;
642 return rc;
643 }
644
645 /**
646 * parse_tag_3_packet
647 * @crypt_stat: The cryptographic context to modify based on packet
648 * contents.
649 * @data: The raw bytes of the packet.
650 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
651 * a new authentication token will be placed at the end
652 * of this list for this packet.
653 * @new_auth_tok: Pointer to a pointer to memory that this function
654 * allocates; sets the memory address of the pointer to
655 * NULL on error. This object is added to the
656 * auth_tok_list.
657 * @packet_size: This function writes the size of the parsed packet
658 * into this memory location; zero on error.
659 * @max_packet_size: maximum number of bytes to parse
660 *
661 * Returns zero on success; non-zero on error.
662 */
663 static int
664 parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
665 unsigned char *data, struct list_head *auth_tok_list,
666 struct ecryptfs_auth_tok **new_auth_tok,
667 size_t *packet_size, size_t max_packet_size)
668 {
669 size_t body_size;
670 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
671 size_t length_size;
672 int rc = 0;
673
674 (*packet_size) = 0;
675 (*new_auth_tok) = NULL;
676 /**
677 *This format is inspired by OpenPGP; see RFC 2440
678 * packet tag 3
679 *
680 * Tag 3 identifier (1 byte)
681 * Max Tag 3 packet size (max 3 bytes)
682 * Version (1 byte)
683 * Cipher code (1 byte)
684 * S2K specifier (1 byte)
685 * Hash identifier (1 byte)
686 * Salt (ECRYPTFS_SALT_SIZE)
687 * Hash iterations (1 byte)
688 * Encrypted key (arbitrary)
689 *
690 * (ECRYPTFS_SALT_SIZE + 7) minimum packet size
691 */
692 if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) {
693 printk(KERN_ERR "Max packet size too large\n");
694 rc = -EINVAL;
695 goto out;
696 }
697 if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) {
698 printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n",
699 ECRYPTFS_TAG_3_PACKET_TYPE);
700 rc = -EINVAL;
701 goto out;
702 }
703 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
704 * at end of function upon failure */
705 auth_tok_list_item =
706 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
707 if (!auth_tok_list_item) {
708 printk(KERN_ERR "Unable to allocate memory\n");
709 rc = -ENOMEM;
710 goto out;
711 }
712 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
713 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
714 &length_size);
715 if (rc) {
716 printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n",
717 rc);
718 goto out_free;
719 }
720 if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) {
721 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
722 rc = -EINVAL;
723 goto out_free;
724 }
725 (*packet_size) += length_size;
726 if (unlikely((*packet_size) + body_size > max_packet_size)) {
727 printk(KERN_ERR "Packet size exceeds max\n");
728 rc = -EINVAL;
729 goto out_free;
730 }
731 (*new_auth_tok)->session_key.encrypted_key_size =
732 (body_size - (ECRYPTFS_SALT_SIZE + 5));
733 if (unlikely(data[(*packet_size)++] != 0x04)) {
734 printk(KERN_WARNING "Unknown version number [%d]\n",
735 data[(*packet_size) - 1]);
736 rc = -EINVAL;
737 goto out_free;
738 }
739 ecryptfs_cipher_code_to_string(crypt_stat->cipher,
740 (u16)data[(*packet_size)]);
741 /* A little extra work to differentiate among the AES key
742 * sizes; see RFC2440 */
743 switch(data[(*packet_size)++]) {
744 case RFC2440_CIPHER_AES_192:
745 crypt_stat->key_size = 24;
746 break;
747 default:
748 crypt_stat->key_size =
749 (*new_auth_tok)->session_key.encrypted_key_size;
750 }
751 ecryptfs_init_crypt_ctx(crypt_stat);
752 if (unlikely(data[(*packet_size)++] != 0x03)) {
753 printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
754 rc = -ENOSYS;
755 goto out_free;
756 }
757 /* TODO: finish the hash mapping */
758 switch (data[(*packet_size)++]) {
759 case 0x01: /* See RFC2440 for these numbers and their mappings */
760 /* Choose MD5 */
761 memcpy((*new_auth_tok)->token.password.salt,
762 &data[(*packet_size)], ECRYPTFS_SALT_SIZE);
763 (*packet_size) += ECRYPTFS_SALT_SIZE;
764 /* This conversion was taken straight from RFC2440 */
765 (*new_auth_tok)->token.password.hash_iterations =
766 ((u32) 16 + (data[(*packet_size)] & 15))
767 << ((data[(*packet_size)] >> 4) + 6);
768 (*packet_size)++;
769 /* Friendly reminder:
770 * (*new_auth_tok)->session_key.encrypted_key_size =
771 * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */
772 memcpy((*new_auth_tok)->session_key.encrypted_key,
773 &data[(*packet_size)],
774 (*new_auth_tok)->session_key.encrypted_key_size);
775 (*packet_size) +=
776 (*new_auth_tok)->session_key.encrypted_key_size;
777 (*new_auth_tok)->session_key.flags &=
778 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
779 (*new_auth_tok)->session_key.flags |=
780 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
781 (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */
782 break;
783 default:
784 ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: "
785 "[%d]\n", data[(*packet_size) - 1]);
786 rc = -ENOSYS;
787 goto out_free;
788 }
789 (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD;
790 /* TODO: Parametarize; we might actually want userspace to
791 * decrypt the session key. */
792 (*new_auth_tok)->session_key.flags &=
793 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
794 (*new_auth_tok)->session_key.flags &=
795 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
796 list_add(&auth_tok_list_item->list, auth_tok_list);
797 goto out;
798 out_free:
799 (*new_auth_tok) = NULL;
800 memset(auth_tok_list_item, 0,
801 sizeof(struct ecryptfs_auth_tok_list_item));
802 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
803 auth_tok_list_item);
804 out:
805 if (rc)
806 (*packet_size) = 0;
807 return rc;
808 }
809
810 /**
811 * parse_tag_11_packet
812 * @data: The raw bytes of the packet
813 * @contents: This function writes the data contents of the literal
814 * packet into this memory location
815 * @max_contents_bytes: The maximum number of bytes that this function
816 * is allowed to write into contents
817 * @tag_11_contents_size: This function writes the size of the parsed
818 * contents into this memory location; zero on
819 * error
820 * @packet_size: This function writes the size of the parsed packet
821 * into this memory location; zero on error
822 * @max_packet_size: maximum number of bytes to parse
823 *
824 * Returns zero on success; non-zero on error.
825 */
826 static int
827 parse_tag_11_packet(unsigned char *data, unsigned char *contents,
828 size_t max_contents_bytes, size_t *tag_11_contents_size,
829 size_t *packet_size, size_t max_packet_size)
830 {
831 size_t body_size;
832 size_t length_size;
833 int rc = 0;
834
835 (*packet_size) = 0;
836 (*tag_11_contents_size) = 0;
837 /* This format is inspired by OpenPGP; see RFC 2440
838 * packet tag 11
839 *
840 * Tag 11 identifier (1 byte)
841 * Max Tag 11 packet size (max 3 bytes)
842 * Binary format specifier (1 byte)
843 * Filename length (1 byte)
844 * Filename ("_CONSOLE") (8 bytes)
845 * Modification date (4 bytes)
846 * Literal data (arbitrary)
847 *
848 * We need at least 16 bytes of data for the packet to even be
849 * valid.
850 */
851 if (max_packet_size < 16) {
852 printk(KERN_ERR "Maximum packet size too small\n");
853 rc = -EINVAL;
854 goto out;
855 }
856 if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) {
857 printk(KERN_WARNING "Invalid tag 11 packet format\n");
858 rc = -EINVAL;
859 goto out;
860 }
861 rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size,
862 &length_size);
863 if (rc) {
864 printk(KERN_WARNING "Invalid tag 11 packet format\n");
865 goto out;
866 }
867 if (body_size < 14) {
868 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
869 rc = -EINVAL;
870 goto out;
871 }
872 (*packet_size) += length_size;
873 (*tag_11_contents_size) = (body_size - 14);
874 if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) {
875 printk(KERN_ERR "Packet size exceeds max\n");
876 rc = -EINVAL;
877 goto out;
878 }
879 if (data[(*packet_size)++] != 0x62) {
880 printk(KERN_WARNING "Unrecognizable packet\n");
881 rc = -EINVAL;
882 goto out;
883 }
884 if (data[(*packet_size)++] != 0x08) {
885 printk(KERN_WARNING "Unrecognizable packet\n");
886 rc = -EINVAL;
887 goto out;
888 }
889 (*packet_size) += 12; /* Ignore filename and modification date */
890 memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size));
891 (*packet_size) += (*tag_11_contents_size);
892 out:
893 if (rc) {
894 (*packet_size) = 0;
895 (*tag_11_contents_size) = 0;
896 }
897 return rc;
898 }
899
900 static int
901 ecryptfs_find_global_auth_tok_for_sig(
902 struct ecryptfs_global_auth_tok **global_auth_tok,
903 struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig)
904 {
905 struct ecryptfs_global_auth_tok *walker;
906 int rc = 0;
907
908 (*global_auth_tok) = NULL;
909 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
910 list_for_each_entry(walker,
911 &mount_crypt_stat->global_auth_tok_list,
912 mount_crypt_stat_list) {
913 if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX) == 0) {
914 (*global_auth_tok) = walker;
915 goto out;
916 }
917 }
918 rc = -EINVAL;
919 out:
920 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
921 return rc;
922 }
923
924 /**
925 * ecryptfs_verify_version
926 * @version: The version number to confirm
927 *
928 * Returns zero on good version; non-zero otherwise
929 */
930 static int ecryptfs_verify_version(u16 version)
931 {
932 int rc = 0;
933 unsigned char major;
934 unsigned char minor;
935
936 major = ((version >> 8) & 0xFF);
937 minor = (version & 0xFF);
938 if (major != ECRYPTFS_VERSION_MAJOR) {
939 ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
940 "Expected [%d]; got [%d]\n",
941 ECRYPTFS_VERSION_MAJOR, major);
942 rc = -EINVAL;
943 goto out;
944 }
945 if (minor != ECRYPTFS_VERSION_MINOR) {
946 ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
947 "Expected [%d]; got [%d]\n",
948 ECRYPTFS_VERSION_MINOR, minor);
949 rc = -EINVAL;
950 goto out;
951 }
952 out:
953 return rc;
954 }
955
956 int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
957 struct ecryptfs_auth_tok **auth_tok,
958 char *sig)
959 {
960 int rc = 0;
961
962 (*auth_tok_key) = request_key(&key_type_user, sig, NULL);
963 if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
964 printk(KERN_ERR "Could not find key with description: [%s]\n",
965 sig);
966 rc = process_request_key_err(PTR_ERR(*auth_tok_key));
967 goto out;
968 }
969 (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key);
970 if (ecryptfs_verify_version((*auth_tok)->version)) {
971 printk(KERN_ERR
972 "Data structure version mismatch. "
973 "Userspace tools must match eCryptfs "
974 "kernel module with major version [%d] "
975 "and minor version [%d]\n",
976 ECRYPTFS_VERSION_MAJOR,
977 ECRYPTFS_VERSION_MINOR);
978 rc = -EINVAL;
979 goto out;
980 }
981 if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
982 && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
983 printk(KERN_ERR "Invalid auth_tok structure "
984 "returned from key query\n");
985 rc = -EINVAL;
986 goto out;
987 }
988 out:
989 return rc;
990 }
991
992 /**
993 * ecryptfs_find_auth_tok_for_sig
994 * @auth_tok: Set to the matching auth_tok; NULL if not found
995 * @crypt_stat: inode crypt_stat crypto context
996 * @sig: Sig of auth_tok to find
997 *
998 * For now, this function simply looks at the registered auth_tok's
999 * linked off the mount_crypt_stat, so all the auth_toks that can be
1000 * used must be registered at mount time. This function could
1001 * potentially try a lot harder to find auth_tok's (e.g., by calling
1002 * out to ecryptfsd to dynamically retrieve an auth_tok object) so
1003 * that static registration of auth_tok's will no longer be necessary.
1004 *
1005 * Returns zero on no error; non-zero on error
1006 */
1007 static int
1008 ecryptfs_find_auth_tok_for_sig(
1009 struct ecryptfs_auth_tok **auth_tok,
1010 struct ecryptfs_crypt_stat *crypt_stat, char *sig)
1011 {
1012 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
1013 crypt_stat->mount_crypt_stat;
1014 struct ecryptfs_global_auth_tok *global_auth_tok;
1015 int rc = 0;
1016
1017 (*auth_tok) = NULL;
1018 if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
1019 mount_crypt_stat, sig)) {
1020 struct key *auth_tok_key;
1021
1022 rc = ecryptfs_keyring_auth_tok_for_sig(&auth_tok_key, auth_tok,
1023 sig);
1024 } else
1025 (*auth_tok) = global_auth_tok->global_auth_tok;
1026 return rc;
1027 }
1028
1029 /**
1030 * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok.
1031 * @auth_tok: The passphrase authentication token to use to encrypt the FEK
1032 * @crypt_stat: The cryptographic context
1033 *
1034 * Returns zero on success; non-zero error otherwise
1035 */
1036 static int
1037 decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1038 struct ecryptfs_crypt_stat *crypt_stat)
1039 {
1040 struct scatterlist dst_sg[2];
1041 struct scatterlist src_sg[2];
1042 struct mutex *tfm_mutex;
1043 struct blkcipher_desc desc = {
1044 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
1045 };
1046 int rc = 0;
1047
1048 if (unlikely(ecryptfs_verbosity > 0)) {
1049 ecryptfs_printk(
1050 KERN_DEBUG, "Session key encryption key (size [%d]):\n",
1051 auth_tok->token.password.session_key_encryption_key_bytes);
1052 ecryptfs_dump_hex(
1053 auth_tok->token.password.session_key_encryption_key,
1054 auth_tok->token.password.session_key_encryption_key_bytes);
1055 }
1056 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
1057 crypt_stat->cipher);
1058 if (unlikely(rc)) {
1059 printk(KERN_ERR "Internal error whilst attempting to get "
1060 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1061 crypt_stat->cipher, rc);
1062 goto out;
1063 }
1064 rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
1065 auth_tok->session_key.encrypted_key_size,
1066 src_sg, 2);
1067 if (rc < 1 || rc > 2) {
1068 printk(KERN_ERR "Internal error whilst attempting to convert "
1069 "auth_tok->session_key.encrypted_key to scatterlist; "
1070 "expected rc = 1; got rc = [%d]. "
1071 "auth_tok->session_key.encrypted_key_size = [%d]\n", rc,
1072 auth_tok->session_key.encrypted_key_size);
1073 goto out;
1074 }
1075 auth_tok->session_key.decrypted_key_size =
1076 auth_tok->session_key.encrypted_key_size;
1077 rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key,
1078 auth_tok->session_key.decrypted_key_size,
1079 dst_sg, 2);
1080 if (rc < 1 || rc > 2) {
1081 printk(KERN_ERR "Internal error whilst attempting to convert "
1082 "auth_tok->session_key.decrypted_key to scatterlist; "
1083 "expected rc = 1; got rc = [%d]\n", rc);
1084 goto out;
1085 }
1086 mutex_lock(tfm_mutex);
1087 rc = crypto_blkcipher_setkey(
1088 desc.tfm, auth_tok->token.password.session_key_encryption_key,
1089 crypt_stat->key_size);
1090 if (unlikely(rc < 0)) {
1091 mutex_unlock(tfm_mutex);
1092 printk(KERN_ERR "Error setting key for crypto context\n");
1093 rc = -EINVAL;
1094 goto out;
1095 }
1096 rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg,
1097 auth_tok->session_key.encrypted_key_size);
1098 mutex_unlock(tfm_mutex);
1099 if (unlikely(rc)) {
1100 printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
1101 goto out;
1102 }
1103 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1104 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1105 auth_tok->session_key.decrypted_key_size);
1106 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1107 if (unlikely(ecryptfs_verbosity > 0)) {
1108 ecryptfs_printk(KERN_DEBUG, "FEK of size [%d]:\n",
1109 crypt_stat->key_size);
1110 ecryptfs_dump_hex(crypt_stat->key,
1111 crypt_stat->key_size);
1112 }
1113 out:
1114 return rc;
1115 }
1116
1117 /**
1118 * ecryptfs_parse_packet_set
1119 * @crypt_stat: The cryptographic context
1120 * @src: Virtual address of region of memory containing the packets
1121 * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set
1122 *
1123 * Get crypt_stat to have the file's session key if the requisite key
1124 * is available to decrypt the session key.
1125 *
1126 * Returns Zero if a valid authentication token was retrieved and
1127 * processed; negative value for file not encrypted or for error
1128 * conditions.
1129 */
1130 int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
1131 unsigned char *src,
1132 struct dentry *ecryptfs_dentry)
1133 {
1134 size_t i = 0;
1135 size_t found_auth_tok;
1136 size_t next_packet_is_auth_tok_packet;
1137 struct list_head auth_tok_list;
1138 struct ecryptfs_auth_tok *matching_auth_tok;
1139 struct ecryptfs_auth_tok *candidate_auth_tok;
1140 char *candidate_auth_tok_sig;
1141 size_t packet_size;
1142 struct ecryptfs_auth_tok *new_auth_tok;
1143 unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE];
1144 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1145 size_t tag_11_contents_size;
1146 size_t tag_11_packet_size;
1147 int rc = 0;
1148
1149 INIT_LIST_HEAD(&auth_tok_list);
1150 /* Parse the header to find as many packets as we can; these will be
1151 * added the our &auth_tok_list */
1152 next_packet_is_auth_tok_packet = 1;
1153 while (next_packet_is_auth_tok_packet) {
1154 size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i);
1155
1156 switch (src[i]) {
1157 case ECRYPTFS_TAG_3_PACKET_TYPE:
1158 rc = parse_tag_3_packet(crypt_stat,
1159 (unsigned char *)&src[i],
1160 &auth_tok_list, &new_auth_tok,
1161 &packet_size, max_packet_size);
1162 if (rc) {
1163 ecryptfs_printk(KERN_ERR, "Error parsing "
1164 "tag 3 packet\n");
1165 rc = -EIO;
1166 goto out_wipe_list;
1167 }
1168 i += packet_size;
1169 rc = parse_tag_11_packet((unsigned char *)&src[i],
1170 sig_tmp_space,
1171 ECRYPTFS_SIG_SIZE,
1172 &tag_11_contents_size,
1173 &tag_11_packet_size,
1174 max_packet_size);
1175 if (rc) {
1176 ecryptfs_printk(KERN_ERR, "No valid "
1177 "(ecryptfs-specific) literal "
1178 "packet containing "
1179 "authentication token "
1180 "signature found after "
1181 "tag 3 packet\n");
1182 rc = -EIO;
1183 goto out_wipe_list;
1184 }
1185 i += tag_11_packet_size;
1186 if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) {
1187 ecryptfs_printk(KERN_ERR, "Expected "
1188 "signature of size [%d]; "
1189 "read size [%d]\n",
1190 ECRYPTFS_SIG_SIZE,
1191 tag_11_contents_size);
1192 rc = -EIO;
1193 goto out_wipe_list;
1194 }
1195 ecryptfs_to_hex(new_auth_tok->token.password.signature,
1196 sig_tmp_space, tag_11_contents_size);
1197 new_auth_tok->token.password.signature[
1198 ECRYPTFS_PASSWORD_SIG_SIZE] = '\0';
1199 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
1200 break;
1201 case ECRYPTFS_TAG_1_PACKET_TYPE:
1202 rc = parse_tag_1_packet(crypt_stat,
1203 (unsigned char *)&src[i],
1204 &auth_tok_list, &new_auth_tok,
1205 &packet_size, max_packet_size);
1206 if (rc) {
1207 ecryptfs_printk(KERN_ERR, "Error parsing "
1208 "tag 1 packet\n");
1209 rc = -EIO;
1210 goto out_wipe_list;
1211 }
1212 i += packet_size;
1213 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
1214 break;
1215 case ECRYPTFS_TAG_11_PACKET_TYPE:
1216 ecryptfs_printk(KERN_WARNING, "Invalid packet set "
1217 "(Tag 11 not allowed by itself)\n");
1218 rc = -EIO;
1219 goto out_wipe_list;
1220 break;
1221 default:
1222 ecryptfs_printk(KERN_DEBUG, "No packet at offset "
1223 "[%d] of the file header; hex value of "
1224 "character is [0x%.2x]\n", i, src[i]);
1225 next_packet_is_auth_tok_packet = 0;
1226 }
1227 }
1228 if (list_empty(&auth_tok_list)) {
1229 printk(KERN_ERR "The lower file appears to be a non-encrypted "
1230 "eCryptfs file; this is not supported in this version "
1231 "of the eCryptfs kernel module\n");
1232 rc = -EINVAL;
1233 goto out;
1234 }
1235 /* auth_tok_list contains the set of authentication tokens
1236 * parsed from the metadata. We need to find a matching
1237 * authentication token that has the secret component(s)
1238 * necessary to decrypt the EFEK in the auth_tok parsed from
1239 * the metadata. There may be several potential matches, but
1240 * just one will be sufficient to decrypt to get the FEK. */
1241 find_next_matching_auth_tok:
1242 found_auth_tok = 0;
1243 list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) {
1244 candidate_auth_tok = &auth_tok_list_item->auth_tok;
1245 if (unlikely(ecryptfs_verbosity > 0)) {
1246 ecryptfs_printk(KERN_DEBUG,
1247 "Considering cadidate auth tok:\n");
1248 ecryptfs_dump_auth_tok(candidate_auth_tok);
1249 }
1250 rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig,
1251 candidate_auth_tok);
1252 if (rc) {
1253 printk(KERN_ERR
1254 "Unrecognized candidate auth tok type: [%d]\n",
1255 candidate_auth_tok->token_type);
1256 rc = -EINVAL;
1257 goto out_wipe_list;
1258 }
1259 ecryptfs_find_auth_tok_for_sig(&matching_auth_tok, crypt_stat,
1260 candidate_auth_tok_sig);
1261 if (matching_auth_tok) {
1262 found_auth_tok = 1;
1263 goto found_matching_auth_tok;
1264 }
1265 }
1266 if (!found_auth_tok) {
1267 ecryptfs_printk(KERN_ERR, "Could not find a usable "
1268 "authentication token\n");
1269 rc = -EIO;
1270 goto out_wipe_list;
1271 }
1272 found_matching_auth_tok:
1273 if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
1274 memcpy(&(candidate_auth_tok->token.private_key),
1275 &(matching_auth_tok->token.private_key),
1276 sizeof(struct ecryptfs_private_key));
1277 rc = decrypt_pki_encrypted_session_key(candidate_auth_tok,
1278 crypt_stat);
1279 } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
1280 memcpy(&(candidate_auth_tok->token.password),
1281 &(matching_auth_tok->token.password),
1282 sizeof(struct ecryptfs_password));
1283 rc = decrypt_passphrase_encrypted_session_key(
1284 candidate_auth_tok, crypt_stat);
1285 }
1286 if (rc) {
1287 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1288
1289 ecryptfs_printk(KERN_WARNING, "Error decrypting the "
1290 "session key for authentication token with sig "
1291 "[%.*s]; rc = [%d]. Removing auth tok "
1292 "candidate from the list and searching for "
1293 "the next match.\n", candidate_auth_tok_sig,
1294 ECRYPTFS_SIG_SIZE_HEX, rc);
1295 list_for_each_entry_safe(auth_tok_list_item,
1296 auth_tok_list_item_tmp,
1297 &auth_tok_list, list) {
1298 if (candidate_auth_tok
1299 == &auth_tok_list_item->auth_tok) {
1300 list_del(&auth_tok_list_item->list);
1301 kmem_cache_free(
1302 ecryptfs_auth_tok_list_item_cache,
1303 auth_tok_list_item);
1304 goto find_next_matching_auth_tok;
1305 }
1306 }
1307 BUG();
1308 }
1309 rc = ecryptfs_compute_root_iv(crypt_stat);
1310 if (rc) {
1311 ecryptfs_printk(KERN_ERR, "Error computing "
1312 "the root IV\n");
1313 goto out_wipe_list;
1314 }
1315 rc = ecryptfs_init_crypt_ctx(crypt_stat);
1316 if (rc) {
1317 ecryptfs_printk(KERN_ERR, "Error initializing crypto "
1318 "context for cipher [%s]; rc = [%d]\n",
1319 crypt_stat->cipher, rc);
1320 }
1321 out_wipe_list:
1322 wipe_auth_tok_list(&auth_tok_list);
1323 out:
1324 return rc;
1325 }
1326
1327 static int
1328 pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
1329 struct ecryptfs_crypt_stat *crypt_stat,
1330 struct ecryptfs_key_record *key_rec)
1331 {
1332 struct ecryptfs_msg_ctx *msg_ctx = NULL;
1333 char *payload = NULL;
1334 size_t payload_len;
1335 struct ecryptfs_message *msg;
1336 int rc;
1337
1338 rc = write_tag_66_packet(auth_tok->token.private_key.signature,
1339 ecryptfs_code_for_cipher_string(crypt_stat),
1340 crypt_stat, &payload, &payload_len);
1341 if (rc) {
1342 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
1343 goto out;
1344 }
1345 rc = ecryptfs_send_message(payload, payload_len, &msg_ctx);
1346 if (rc) {
1347 ecryptfs_printk(KERN_ERR, "Error sending message to "
1348 "ecryptfsd\n");
1349 goto out;
1350 }
1351 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1352 if (rc) {
1353 ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet "
1354 "from the user space daemon\n");
1355 rc = -EIO;
1356 goto out;
1357 }
1358 rc = parse_tag_67_packet(key_rec, msg);
1359 if (rc)
1360 ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n");
1361 kfree(msg);
1362 out:
1363 kfree(payload);
1364 return rc;
1365 }
1366 /**
1367 * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet
1368 * @dest: Buffer into which to write the packet
1369 * @remaining_bytes: Maximum number of bytes that can be writtn
1370 * @auth_tok: The authentication token used for generating the tag 1 packet
1371 * @crypt_stat: The cryptographic context
1372 * @key_rec: The key record struct for the tag 1 packet
1373 * @packet_size: This function will write the number of bytes that end
1374 * up constituting the packet; set to zero on error
1375 *
1376 * Returns zero on success; non-zero on error.
1377 */
1378 static int
1379 write_tag_1_packet(char *dest, size_t *remaining_bytes,
1380 struct ecryptfs_auth_tok *auth_tok,
1381 struct ecryptfs_crypt_stat *crypt_stat,
1382 struct ecryptfs_key_record *key_rec, size_t *packet_size)
1383 {
1384 size_t i;
1385 size_t encrypted_session_key_valid = 0;
1386 size_t packet_size_length;
1387 size_t max_packet_size;
1388 int rc = 0;
1389
1390 (*packet_size) = 0;
1391 ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature,
1392 ECRYPTFS_SIG_SIZE);
1393 encrypted_session_key_valid = 0;
1394 for (i = 0; i < crypt_stat->key_size; i++)
1395 encrypted_session_key_valid |=
1396 auth_tok->session_key.encrypted_key[i];
1397 if (encrypted_session_key_valid) {
1398 memcpy(key_rec->enc_key,
1399 auth_tok->session_key.encrypted_key,
1400 auth_tok->session_key.encrypted_key_size);
1401 goto encrypted_session_key_set;
1402 }
1403 if (auth_tok->session_key.encrypted_key_size == 0)
1404 auth_tok->session_key.encrypted_key_size =
1405 auth_tok->token.private_key.key_size;
1406 rc = pki_encrypt_session_key(auth_tok, crypt_stat, key_rec);
1407 if (rc) {
1408 printk(KERN_ERR "Failed to encrypt session key via a key "
1409 "module; rc = [%d]\n", rc);
1410 goto out;
1411 }
1412 if (ecryptfs_verbosity > 0) {
1413 ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n");
1414 ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size);
1415 }
1416 encrypted_session_key_set:
1417 /* This format is inspired by OpenPGP; see RFC 2440
1418 * packet tag 1 */
1419 max_packet_size = (1 /* Tag 1 identifier */
1420 + 3 /* Max Tag 1 packet size */
1421 + 1 /* Version */
1422 + ECRYPTFS_SIG_SIZE /* Key identifier */
1423 + 1 /* Cipher identifier */
1424 + key_rec->enc_key_size); /* Encrypted key size */
1425 if (max_packet_size > (*remaining_bytes)) {
1426 printk(KERN_ERR "Packet length larger than maximum allowable; "
1427 "need up to [%td] bytes, but there are only [%td] "
1428 "available\n", max_packet_size, (*remaining_bytes));
1429 rc = -EINVAL;
1430 goto out;
1431 }
1432 dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE;
1433 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
1434 (max_packet_size - 4),
1435 &packet_size_length);
1436 if (rc) {
1437 ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet "
1438 "header; cannot generate packet length\n");
1439 goto out;
1440 }
1441 (*packet_size) += packet_size_length;
1442 dest[(*packet_size)++] = 0x03; /* version 3 */
1443 memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE);
1444 (*packet_size) += ECRYPTFS_SIG_SIZE;
1445 dest[(*packet_size)++] = RFC2440_CIPHER_RSA;
1446 memcpy(&dest[(*packet_size)], key_rec->enc_key,
1447 key_rec->enc_key_size);
1448 (*packet_size) += key_rec->enc_key_size;
1449 out:
1450 if (rc)
1451 (*packet_size) = 0;
1452 else
1453 (*remaining_bytes) -= (*packet_size);
1454 return rc;
1455 }
1456
1457 /**
1458 * write_tag_11_packet
1459 * @dest: Target into which Tag 11 packet is to be written
1460 * @remaining_bytes: Maximum packet length
1461 * @contents: Byte array of contents to copy in
1462 * @contents_length: Number of bytes in contents
1463 * @packet_length: Length of the Tag 11 packet written; zero on error
1464 *
1465 * Returns zero on success; non-zero on error.
1466 */
1467 static int
1468 write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents,
1469 size_t contents_length, size_t *packet_length)
1470 {
1471 size_t packet_size_length;
1472 size_t max_packet_size;
1473 int rc = 0;
1474
1475 (*packet_length) = 0;
1476 /* This format is inspired by OpenPGP; see RFC 2440
1477 * packet tag 11 */
1478 max_packet_size = (1 /* Tag 11 identifier */
1479 + 3 /* Max Tag 11 packet size */
1480 + 1 /* Binary format specifier */
1481 + 1 /* Filename length */
1482 + 8 /* Filename ("_CONSOLE") */
1483 + 4 /* Modification date */
1484 + contents_length); /* Literal data */
1485 if (max_packet_size > (*remaining_bytes)) {
1486 printk(KERN_ERR "Packet length larger than maximum allowable; "
1487 "need up to [%td] bytes, but there are only [%td] "
1488 "available\n", max_packet_size, (*remaining_bytes));
1489 rc = -EINVAL;
1490 goto out;
1491 }
1492 dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE;
1493 rc = ecryptfs_write_packet_length(&dest[(*packet_length)],
1494 (max_packet_size - 4),
1495 &packet_size_length);
1496 if (rc) {
1497 printk(KERN_ERR "Error generating tag 11 packet header; cannot "
1498 "generate packet length. rc = [%d]\n", rc);
1499 goto out;
1500 }
1501 (*packet_length) += packet_size_length;
1502 dest[(*packet_length)++] = 0x62; /* binary data format specifier */
1503 dest[(*packet_length)++] = 8;
1504 memcpy(&dest[(*packet_length)], "_CONSOLE", 8);
1505 (*packet_length) += 8;
1506 memset(&dest[(*packet_length)], 0x00, 4);
1507 (*packet_length) += 4;
1508 memcpy(&dest[(*packet_length)], contents, contents_length);
1509 (*packet_length) += contents_length;
1510 out:
1511 if (rc)
1512 (*packet_length) = 0;
1513 else
1514 (*remaining_bytes) -= (*packet_length);
1515 return rc;
1516 }
1517
1518 /**
1519 * write_tag_3_packet
1520 * @dest: Buffer into which to write the packet
1521 * @remaining_bytes: Maximum number of bytes that can be written
1522 * @auth_tok: Authentication token
1523 * @crypt_stat: The cryptographic context
1524 * @key_rec: encrypted key
1525 * @packet_size: This function will write the number of bytes that end
1526 * up constituting the packet; set to zero on error
1527 *
1528 * Returns zero on success; non-zero on error.
1529 */
1530 static int
1531 write_tag_3_packet(char *dest, size_t *remaining_bytes,
1532 struct ecryptfs_auth_tok *auth_tok,
1533 struct ecryptfs_crypt_stat *crypt_stat,
1534 struct ecryptfs_key_record *key_rec, size_t *packet_size)
1535 {
1536 size_t i;
1537 size_t encrypted_session_key_valid = 0;
1538 char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
1539 struct scatterlist dst_sg[2];
1540 struct scatterlist src_sg[2];
1541 struct mutex *tfm_mutex = NULL;
1542 u8 cipher_code;
1543 size_t packet_size_length;
1544 size_t max_packet_size;
1545 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
1546 crypt_stat->mount_crypt_stat;
1547 struct blkcipher_desc desc = {
1548 .tfm = NULL,
1549 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
1550 };
1551 int rc = 0;
1552
1553 (*packet_size) = 0;
1554 ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
1555 ECRYPTFS_SIG_SIZE);
1556 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
1557 crypt_stat->cipher);
1558 if (unlikely(rc)) {
1559 printk(KERN_ERR "Internal error whilst attempting to get "
1560 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1561 crypt_stat->cipher, rc);
1562 goto out;
1563 }
1564 if (mount_crypt_stat->global_default_cipher_key_size == 0) {
1565 struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm);
1566
1567 printk(KERN_WARNING "No key size specified at mount; "
1568 "defaulting to [%d]\n", alg->max_keysize);
1569 mount_crypt_stat->global_default_cipher_key_size =
1570 alg->max_keysize;
1571 }
1572 if (crypt_stat->key_size == 0)
1573 crypt_stat->key_size =
1574 mount_crypt_stat->global_default_cipher_key_size;
1575 if (auth_tok->session_key.encrypted_key_size == 0)
1576 auth_tok->session_key.encrypted_key_size =
1577 crypt_stat->key_size;
1578 if (crypt_stat->key_size == 24
1579 && strcmp("aes", crypt_stat->cipher) == 0) {
1580 memset((crypt_stat->key + 24), 0, 8);
1581 auth_tok->session_key.encrypted_key_size = 32;
1582 } else
1583 auth_tok->session_key.encrypted_key_size = crypt_stat->key_size;
1584 key_rec->enc_key_size =
1585 auth_tok->session_key.encrypted_key_size;
1586 encrypted_session_key_valid = 0;
1587 for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++)
1588 encrypted_session_key_valid |=
1589 auth_tok->session_key.encrypted_key[i];
1590 if (encrypted_session_key_valid) {
1591 ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; "
1592 "using auth_tok->session_key.encrypted_key, "
1593 "where key_rec->enc_key_size = [%d]\n",
1594 key_rec->enc_key_size);
1595 memcpy(key_rec->enc_key,
1596 auth_tok->session_key.encrypted_key,
1597 key_rec->enc_key_size);
1598 goto encrypted_session_key_set;
1599 }
1600 if (auth_tok->token.password.flags &
1601 ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) {
1602 ecryptfs_printk(KERN_DEBUG, "Using previously generated "
1603 "session key encryption key of size [%d]\n",
1604 auth_tok->token.password.
1605 session_key_encryption_key_bytes);
1606 memcpy(session_key_encryption_key,
1607 auth_tok->token.password.session_key_encryption_key,
1608 crypt_stat->key_size);
1609 ecryptfs_printk(KERN_DEBUG,
1610 "Cached session key " "encryption key: \n");
1611 if (ecryptfs_verbosity > 0)
1612 ecryptfs_dump_hex(session_key_encryption_key, 16);
1613 }
1614 if (unlikely(ecryptfs_verbosity > 0)) {
1615 ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n");
1616 ecryptfs_dump_hex(session_key_encryption_key, 16);
1617 }
1618 rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size,
1619 src_sg, 2);
1620 if (rc < 1 || rc > 2) {
1621 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
1622 "for crypt_stat session key; expected rc = 1; "
1623 "got rc = [%d]. key_rec->enc_key_size = [%d]\n",
1624 rc, key_rec->enc_key_size);
1625 rc = -ENOMEM;
1626 goto out;
1627 }
1628 rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size,
1629 dst_sg, 2);
1630 if (rc < 1 || rc > 2) {
1631 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
1632 "for crypt_stat encrypted session key; "
1633 "expected rc = 1; got rc = [%d]. "
1634 "key_rec->enc_key_size = [%d]\n", rc,
1635 key_rec->enc_key_size);
1636 rc = -ENOMEM;
1637 goto out;
1638 }
1639 mutex_lock(tfm_mutex);
1640 rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key,
1641 crypt_stat->key_size);
1642 if (rc < 0) {
1643 mutex_unlock(tfm_mutex);
1644 ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
1645 "context; rc = [%d]\n", rc);
1646 goto out;
1647 }
1648 rc = 0;
1649 ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n",
1650 crypt_stat->key_size);
1651 rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg,
1652 (*key_rec).enc_key_size);
1653 mutex_unlock(tfm_mutex);
1654 if (rc) {
1655 printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc);
1656 goto out;
1657 }
1658 ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
1659 if (ecryptfs_verbosity > 0) {
1660 ecryptfs_printk(KERN_DEBUG, "EFEK of size [%d]:\n",
1661 key_rec->enc_key_size);
1662 ecryptfs_dump_hex(key_rec->enc_key,
1663 key_rec->enc_key_size);
1664 }
1665 encrypted_session_key_set:
1666 /* This format is inspired by OpenPGP; see RFC 2440
1667 * packet tag 3 */
1668 max_packet_size = (1 /* Tag 3 identifier */
1669 + 3 /* Max Tag 3 packet size */
1670 + 1 /* Version */
1671 + 1 /* Cipher code */
1672 + 1 /* S2K specifier */
1673 + 1 /* Hash identifier */
1674 + ECRYPTFS_SALT_SIZE /* Salt */
1675 + 1 /* Hash iterations */
1676 + key_rec->enc_key_size); /* Encrypted key size */
1677 if (max_packet_size > (*remaining_bytes)) {
1678 printk(KERN_ERR "Packet too large; need up to [%td] bytes, but "
1679 "there are only [%td] available\n", max_packet_size,
1680 (*remaining_bytes));
1681 rc = -EINVAL;
1682 goto out;
1683 }
1684 dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE;
1685 /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3)
1686 * to get the number of octets in the actual Tag 3 packet */
1687 rc = ecryptfs_write_packet_length(&dest[(*packet_size)],
1688 (max_packet_size - 4),
1689 &packet_size_length);
1690 if (rc) {
1691 printk(KERN_ERR "Error generating tag 3 packet header; cannot "
1692 "generate packet length. rc = [%d]\n", rc);
1693 goto out;
1694 }
1695 (*packet_size) += packet_size_length;
1696 dest[(*packet_size)++] = 0x04; /* version 4 */
1697 /* TODO: Break from RFC2440 so that arbitrary ciphers can be
1698 * specified with strings */
1699 cipher_code = ecryptfs_code_for_cipher_string(crypt_stat);
1700 if (cipher_code == 0) {
1701 ecryptfs_printk(KERN_WARNING, "Unable to generate code for "
1702 "cipher [%s]\n", crypt_stat->cipher);
1703 rc = -EINVAL;
1704 goto out;
1705 }
1706 dest[(*packet_size)++] = cipher_code;
1707 dest[(*packet_size)++] = 0x03; /* S2K */
1708 dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */
1709 memcpy(&dest[(*packet_size)], auth_tok->token.password.salt,
1710 ECRYPTFS_SALT_SIZE);
1711 (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */
1712 dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */
1713 memcpy(&dest[(*packet_size)], key_rec->enc_key,
1714 key_rec->enc_key_size);
1715 (*packet_size) += key_rec->enc_key_size;
1716 out:
1717 if (rc)
1718 (*packet_size) = 0;
1719 else
1720 (*remaining_bytes) -= (*packet_size);
1721 return rc;
1722 }
1723
1724 struct kmem_cache *ecryptfs_key_record_cache;
1725
1726 /**
1727 * ecryptfs_generate_key_packet_set
1728 * @dest_base: Virtual address from which to write the key record set
1729 * @crypt_stat: The cryptographic context from which the
1730 * authentication tokens will be retrieved
1731 * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat
1732 * for the global parameters
1733 * @len: The amount written
1734 * @max: The maximum amount of data allowed to be written
1735 *
1736 * Generates a key packet set and writes it to the virtual address
1737 * passed in.
1738 *
1739 * Returns zero on success; non-zero on error.
1740 */
1741 int
1742 ecryptfs_generate_key_packet_set(char *dest_base,
1743 struct ecryptfs_crypt_stat *crypt_stat,
1744 struct dentry *ecryptfs_dentry, size_t *len,
1745 size_t max)
1746 {
1747 struct ecryptfs_auth_tok *auth_tok;
1748 struct ecryptfs_global_auth_tok *global_auth_tok;
1749 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
1750 &ecryptfs_superblock_to_private(
1751 ecryptfs_dentry->d_sb)->mount_crypt_stat;
1752 size_t written;
1753 struct ecryptfs_key_record *key_rec;
1754 struct ecryptfs_key_sig *key_sig;
1755 int rc = 0;
1756
1757 (*len) = 0;
1758 mutex_lock(&crypt_stat->keysig_list_mutex);
1759 key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL);
1760 if (!key_rec) {
1761 rc = -ENOMEM;
1762 goto out;
1763 }
1764 list_for_each_entry(key_sig, &crypt_stat->keysig_list,
1765 crypt_stat_list) {
1766 memset(key_rec, 0, sizeof(*key_rec));
1767 rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
1768 mount_crypt_stat,
1769 key_sig->keysig);
1770 if (rc) {
1771 printk(KERN_ERR "Error attempting to get the global "
1772 "auth_tok; rc = [%d]\n", rc);
1773 goto out_free;
1774 }
1775 if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) {
1776 printk(KERN_WARNING
1777 "Skipping invalid auth tok with sig = [%s]\n",
1778 global_auth_tok->sig);
1779 continue;
1780 }
1781 auth_tok = global_auth_tok->global_auth_tok;
1782 if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
1783 rc = write_tag_3_packet((dest_base + (*len)),
1784 &max, auth_tok,
1785 crypt_stat, key_rec,
1786 &written);
1787 if (rc) {
1788 ecryptfs_printk(KERN_WARNING, "Error "
1789 "writing tag 3 packet\n");
1790 goto out_free;
1791 }
1792 (*len) += written;
1793 /* Write auth tok signature packet */
1794 rc = write_tag_11_packet((dest_base + (*len)), &max,
1795 key_rec->sig,
1796 ECRYPTFS_SIG_SIZE, &written);
1797 if (rc) {
1798 ecryptfs_printk(KERN_ERR, "Error writing "
1799 "auth tok signature packet\n");
1800 goto out_free;
1801 }
1802 (*len) += written;
1803 } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
1804 rc = write_tag_1_packet(dest_base + (*len),
1805 &max, auth_tok,
1806 crypt_stat, key_rec, &written);
1807 if (rc) {
1808 ecryptfs_printk(KERN_WARNING, "Error "
1809 "writing tag 1 packet\n");
1810 goto out_free;
1811 }
1812 (*len) += written;
1813 } else {
1814 ecryptfs_printk(KERN_WARNING, "Unsupported "
1815 "authentication token type\n");
1816 rc = -EINVAL;
1817 goto out_free;
1818 }
1819 }
1820 if (likely(max > 0)) {
1821 dest_base[(*len)] = 0x00;
1822 } else {
1823 ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n");
1824 rc = -EIO;
1825 }
1826 out_free:
1827 kmem_cache_free(ecryptfs_key_record_cache, key_rec);
1828 out:
1829 if (rc)
1830 (*len) = 0;
1831 mutex_unlock(&crypt_stat->keysig_list_mutex);
1832 return rc;
1833 }
1834
1835 struct kmem_cache *ecryptfs_key_sig_cache;
1836
1837 int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig)
1838 {
1839 struct ecryptfs_key_sig *new_key_sig;
1840 int rc = 0;
1841
1842 new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL);
1843 if (!new_key_sig) {
1844 rc = -ENOMEM;
1845 printk(KERN_ERR
1846 "Error allocating from ecryptfs_key_sig_cache\n");
1847 goto out;
1848 }
1849 memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
1850 mutex_lock(&crypt_stat->keysig_list_mutex);
1851 list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
1852 mutex_unlock(&crypt_stat->keysig_list_mutex);
1853 out:
1854 return rc;
1855 }
1856
1857 struct kmem_cache *ecryptfs_global_auth_tok_cache;
1858
1859 int
1860 ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
1861 char *sig)
1862 {
1863 struct ecryptfs_global_auth_tok *new_auth_tok;
1864 int rc = 0;
1865
1866 new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache,
1867 GFP_KERNEL);
1868 if (!new_auth_tok) {
1869 rc = -ENOMEM;
1870 printk(KERN_ERR "Error allocating from "
1871 "ecryptfs_global_auth_tok_cache\n");
1872 goto out;
1873 }
1874 memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX);
1875 new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
1876 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
1877 list_add(&new_auth_tok->mount_crypt_stat_list,
1878 &mount_crypt_stat->global_auth_tok_list);
1879 mount_crypt_stat->num_global_auth_toks++;
1880 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
1881 out:
1882 return rc;
1883 }
1884
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