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[linux-2.6/mini2440.git] / fs / ecryptfs / keystore.c
blob263fed88c0cabac8e37e8b6801d50bdac0500326
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 * 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 static int 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 * 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 static int 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 = 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 = write_packet_length(&message[i], session_key->encrypted_key_size,
176 &packet_size_len);
177 if (rc) {
178 ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet "
179 "header; cannot generate packet length\n");
180 goto out;
181 }
182 i += packet_size_len;
183 memcpy(&message[i], session_key->encrypted_key,
184 session_key->encrypted_key_size);
185 i += session_key->encrypted_key_size;
186 *packet_len = i;
187 out:
188 return rc;
189 }
190
191 static int
192 parse_tag_65_packet(struct ecryptfs_session_key *session_key, u16 *cipher_code,
193 struct ecryptfs_message *msg)
194 {
195 size_t i = 0;
196 char *data;
197 size_t data_len;
198 size_t m_size;
199 size_t message_len;
200 u16 checksum = 0;
201 u16 expected_checksum = 0;
202 int rc;
203
204 /*
205 * ***** TAG 65 Packet Format *****
206 * | Content Type | 1 byte |
207 * | Status Indicator | 1 byte |
208 * | File Encryption Key Size | 1 or 2 bytes |
209 * | File Encryption Key | arbitrary |
210 */
211 message_len = msg->data_len;
212 data = msg->data;
213 if (message_len < 4) {
214 rc = -EIO;
215 goto out;
216 }
217 if (data[i++] != ECRYPTFS_TAG_65_PACKET_TYPE) {
218 ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_65\n");
219 rc = -EIO;
220 goto out;
221 }
222 if (data[i++]) {
223 ecryptfs_printk(KERN_ERR, "Status indicator has non-zero value "
224 "[%d]\n", data[i-1]);
225 rc = -EIO;
226 goto out;
227 }
228 rc = parse_packet_length(&data[i], &m_size, &data_len);
229 if (rc) {
230 ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
231 "rc = [%d]\n", rc);
232 goto out;
233 }
234 i += data_len;
235 if (message_len < (i + m_size)) {
236 ecryptfs_printk(KERN_ERR, "The received netlink message is "
237 "shorter than expected\n");
238 rc = -EIO;
239 goto out;
240 }
241 if (m_size < 3) {
242 ecryptfs_printk(KERN_ERR,
243 "The decrypted key is not long enough to "
244 "include a cipher code and checksum\n");
245 rc = -EIO;
246 goto out;
247 }
248 *cipher_code = data[i++];
249 /* The decrypted key includes 1 byte cipher code and 2 byte checksum */
250 session_key->decrypted_key_size = m_size - 3;
251 if (session_key->decrypted_key_size > ECRYPTFS_MAX_KEY_BYTES) {
252 ecryptfs_printk(KERN_ERR, "key_size [%d] larger than "
253 "the maximum key size [%d]\n",
254 session_key->decrypted_key_size,
255 ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES);
256 rc = -EIO;
257 goto out;
258 }
259 memcpy(session_key->decrypted_key, &data[i],
260 session_key->decrypted_key_size);
261 i += session_key->decrypted_key_size;
262 expected_checksum += (unsigned char)(data[i++]) << 8;
263 expected_checksum += (unsigned char)(data[i++]);
264 for (i = 0; i < session_key->decrypted_key_size; i++)
265 checksum += session_key->decrypted_key[i];
266 if (expected_checksum != checksum) {
267 ecryptfs_printk(KERN_ERR, "Invalid checksum for file "
268 "encryption key; expected [%x]; calculated "
269 "[%x]\n", expected_checksum, checksum);
270 rc = -EIO;
271 }
272 out:
273 return rc;
274 }
275
276
277 static int
278 write_tag_66_packet(char *signature, size_t cipher_code,
279 struct ecryptfs_crypt_stat *crypt_stat, char **packet,
280 size_t *packet_len)
281 {
282 size_t i = 0;
283 size_t j;
284 size_t data_len;
285 size_t checksum = 0;
286 size_t packet_size_len;
287 char *message;
288 int rc;
289
290 /*
291 * ***** TAG 66 Packet Format *****
292 * | Content Type | 1 byte |
293 * | Key Identifier Size | 1 or 2 bytes |
294 * | Key Identifier | arbitrary |
295 * | File Encryption Key Size | 1 or 2 bytes |
296 * | File Encryption Key | arbitrary |
297 */
298 data_len = (5 + ECRYPTFS_SIG_SIZE_HEX + crypt_stat->key_size);
299 *packet = kmalloc(data_len, GFP_KERNEL);
300 message = *packet;
301 if (!message) {
302 ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n");
303 rc = -ENOMEM;
304 goto out;
305 }
306 message[i++] = ECRYPTFS_TAG_66_PACKET_TYPE;
307 rc = write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX,
308 &packet_size_len);
309 if (rc) {
310 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet "
311 "header; cannot generate packet length\n");
312 goto out;
313 }
314 i += packet_size_len;
315 memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX);
316 i += ECRYPTFS_SIG_SIZE_HEX;
317 /* The encrypted key includes 1 byte cipher code and 2 byte checksum */
318 rc = write_packet_length(&message[i], crypt_stat->key_size + 3,
319 &packet_size_len);
320 if (rc) {
321 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet "
322 "header; cannot generate packet length\n");
323 goto out;
324 }
325 i += packet_size_len;
326 message[i++] = cipher_code;
327 memcpy(&message[i], crypt_stat->key, crypt_stat->key_size);
328 i += crypt_stat->key_size;
329 for (j = 0; j < crypt_stat->key_size; j++)
330 checksum += crypt_stat->key[j];
331 message[i++] = (checksum / 256) % 256;
332 message[i++] = (checksum % 256);
333 *packet_len = i;
334 out:
335 return rc;
336 }
337
338 static int
339 parse_tag_67_packet(struct ecryptfs_key_record *key_rec,
340 struct ecryptfs_message *msg)
341 {
342 size_t i = 0;
343 char *data;
344 size_t data_len;
345 size_t message_len;
346 int rc;
347
348 /*
349 * ***** TAG 65 Packet Format *****
350 * | Content Type | 1 byte |
351 * | Status Indicator | 1 byte |
352 * | Encrypted File Encryption Key Size | 1 or 2 bytes |
353 * | Encrypted File Encryption Key | arbitrary |
354 */
355 message_len = msg->data_len;
356 data = msg->data;
357 /* verify that everything through the encrypted FEK size is present */
358 if (message_len < 4) {
359 rc = -EIO;
360 goto out;
361 }
362 if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) {
363 ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_67\n");
364 rc = -EIO;
365 goto out;
366 }
367 if (data[i++]) {
368 ecryptfs_printk(KERN_ERR, "Status indicator has non zero value"
369 " [%d]\n", data[i-1]);
370 rc = -EIO;
371 goto out;
372 }
373 rc = parse_packet_length(&data[i], &key_rec->enc_key_size, &data_len);
374 if (rc) {
375 ecryptfs_printk(KERN_WARNING, "Error parsing packet length; "
376 "rc = [%d]\n", rc);
377 goto out;
378 }
379 i += data_len;
380 if (message_len < (i + key_rec->enc_key_size)) {
381 ecryptfs_printk(KERN_ERR, "message_len [%d]; max len is [%d]\n",
382 message_len, (i + key_rec->enc_key_size));
383 rc = -EIO;
384 goto out;
385 }
386 if (key_rec->enc_key_size > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
387 ecryptfs_printk(KERN_ERR, "Encrypted key_size [%d] larger than "
388 "the maximum key size [%d]\n",
389 key_rec->enc_key_size,
390 ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES);
391 rc = -EIO;
392 goto out;
393 }
394 memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size);
395 out:
396 return rc;
397 }
398
399 static int
400 ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok)
401 {
402 int rc = 0;
403
404 (*sig) = NULL;
405 switch (auth_tok->token_type) {
406 case ECRYPTFS_PASSWORD:
407 (*sig) = auth_tok->token.password.signature;
408 break;
409 case ECRYPTFS_PRIVATE_KEY:
410 (*sig) = auth_tok->token.private_key.signature;
411 break;
412 default:
413 printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n",
414 auth_tok->token_type);
415 rc = -EINVAL;
416 }
417 return rc;
418 }
419
420 /**
421 * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok.
422 * @auth_tok: The key authentication token used to decrypt the session key
423 * @crypt_stat: The cryptographic context
424 *
425 * Returns zero on success; non-zero error otherwise.
426 */
427 static int
428 decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
429 struct ecryptfs_crypt_stat *crypt_stat)
430 {
431 u16 cipher_code = 0;
432 struct ecryptfs_msg_ctx *msg_ctx;
433 struct ecryptfs_message *msg = NULL;
434 char *auth_tok_sig;
435 char *netlink_message;
436 size_t netlink_message_length;
437 int rc;
438
439 rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok);
440 if (rc) {
441 printk(KERN_ERR "Unrecognized auth tok type: [%d]\n",
442 auth_tok->token_type);
443 goto out;
444 }
445 rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key),
446 &netlink_message, &netlink_message_length);
447 if (rc) {
448 ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet");
449 goto out;
450 }
451 rc = ecryptfs_send_message(ecryptfs_transport, netlink_message,
452 netlink_message_length, &msg_ctx);
453 if (rc) {
454 ecryptfs_printk(KERN_ERR, "Error sending netlink message\n");
455 goto out;
456 }
457 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
458 if (rc) {
459 ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet "
460 "from the user space daemon\n");
461 rc = -EIO;
462 goto out;
463 }
464 rc = parse_tag_65_packet(&(auth_tok->session_key),
465 &cipher_code, msg);
466 if (rc) {
467 printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n",
468 rc);
469 goto out;
470 }
471 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
472 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
473 auth_tok->session_key.decrypted_key_size);
474 crypt_stat->key_size = auth_tok->session_key.decrypted_key_size;
475 rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code);
476 if (rc) {
477 ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n",
478 cipher_code)
479 goto out;
480 }
481 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
482 if (ecryptfs_verbosity > 0) {
483 ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n");
484 ecryptfs_dump_hex(crypt_stat->key,
485 crypt_stat->key_size);
486 }
487 out:
488 if (msg)
489 kfree(msg);
490 return rc;
491 }
492
493 static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
494 {
495 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
496 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
497
498 list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp,
499 auth_tok_list_head, list) {
500 list_del(&auth_tok_list_item->list);
501 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
502 auth_tok_list_item);
503 }
504 }
505
506 struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
507
508 /**
509 * parse_tag_1_packet
510 * @crypt_stat: The cryptographic context to modify based on packet contents
511 * @data: The raw bytes of the packet.
512 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
513 * a new authentication token will be placed at the
514 * end of this list for this packet.
515 * @new_auth_tok: Pointer to a pointer to memory that this function
516 * allocates; sets the memory address of the pointer to
517 * NULL on error. This object is added to the
518 * auth_tok_list.
519 * @packet_size: This function writes the size of the parsed packet
520 * into this memory location; zero on error.
521 * @max_packet_size: The maximum allowable packet size
522 *
523 * Returns zero on success; non-zero on error.
524 */
525 static int
526 parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
527 unsigned char *data, struct list_head *auth_tok_list,
528 struct ecryptfs_auth_tok **new_auth_tok,
529 size_t *packet_size, size_t max_packet_size)
530 {
531 size_t body_size;
532 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
533 size_t length_size;
534 int rc = 0;
535
536 (*packet_size) = 0;
537 (*new_auth_tok) = NULL;
538 /**
539 * This format is inspired by OpenPGP; see RFC 2440
540 * packet tag 1
541 *
542 * Tag 1 identifier (1 byte)
543 * Max Tag 1 packet size (max 3 bytes)
544 * Version (1 byte)
545 * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE)
546 * Cipher identifier (1 byte)
547 * Encrypted key size (arbitrary)
548 *
549 * 12 bytes minimum packet size
550 */
551 if (unlikely(max_packet_size < 12)) {
552 printk(KERN_ERR "Invalid max packet size; must be >=12\n");
553 rc = -EINVAL;
554 goto out;
555 }
556 if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) {
557 printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n",
558 ECRYPTFS_TAG_1_PACKET_TYPE);
559 rc = -EINVAL;
560 goto out;
561 }
562 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
563 * at end of function upon failure */
564 auth_tok_list_item =
565 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache,
566 GFP_KERNEL);
567 if (!auth_tok_list_item) {
568 printk(KERN_ERR "Unable to allocate memory\n");
569 rc = -ENOMEM;
570 goto out;
571 }
572 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
573 rc = parse_packet_length(&data[(*packet_size)], &body_size,
574 &length_size);
575 if (rc) {
576 printk(KERN_WARNING "Error parsing packet length; "
577 "rc = [%d]\n", rc);
578 goto out_free;
579 }
580 if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) {
581 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
582 rc = -EINVAL;
583 goto out_free;
584 }
585 (*packet_size) += length_size;
586 if (unlikely((*packet_size) + body_size > max_packet_size)) {
587 printk(KERN_WARNING "Packet size exceeds max\n");
588 rc = -EINVAL;
589 goto out_free;
590 }
591 if (unlikely(data[(*packet_size)++] != 0x03)) {
592 printk(KERN_WARNING "Unknown version number [%d]\n",
593 data[(*packet_size) - 1]);
594 rc = -EINVAL;
595 goto out_free;
596 }
597 ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
598 &data[(*packet_size)], ECRYPTFS_SIG_SIZE);
599 *packet_size += ECRYPTFS_SIG_SIZE;
600 /* This byte is skipped because the kernel does not need to
601 * know which public key encryption algorithm was used */
602 (*packet_size)++;
603 (*new_auth_tok)->session_key.encrypted_key_size =
604 body_size - (ECRYPTFS_SIG_SIZE + 2);
605 if ((*new_auth_tok)->session_key.encrypted_key_size
606 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
607 printk(KERN_WARNING "Tag 1 packet contains key larger "
608 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
609 rc = -EINVAL;
610 goto out;
611 }
612 memcpy((*new_auth_tok)->session_key.encrypted_key,
613 &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2)));
614 (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size;
615 (*new_auth_tok)->session_key.flags &=
616 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
617 (*new_auth_tok)->session_key.flags |=
618 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
619 (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY;
620 (*new_auth_tok)->flags = 0;
621 (*new_auth_tok)->session_key.flags &=
622 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
623 (*new_auth_tok)->session_key.flags &=
624 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
625 list_add(&auth_tok_list_item->list, auth_tok_list);
626 goto out;
627 out_free:
628 (*new_auth_tok) = NULL;
629 memset(auth_tok_list_item, 0,
630 sizeof(struct ecryptfs_auth_tok_list_item));
631 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
632 auth_tok_list_item);
633 out:
634 if (rc)
635 (*packet_size) = 0;
636 return rc;
637 }
638
639 /**
640 * parse_tag_3_packet
641 * @crypt_stat: The cryptographic context to modify based on packet
642 * contents.
643 * @data: The raw bytes of the packet.
644 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
645 * a new authentication token will be placed at the end
646 * of this list for this packet.
647 * @new_auth_tok: Pointer to a pointer to memory that this function
648 * allocates; sets the memory address of the pointer to
649 * NULL on error. This object is added to the
650 * auth_tok_list.
651 * @packet_size: This function writes the size of the parsed packet
652 * into this memory location; zero on error.
653 * @max_packet_size: maximum number of bytes to parse
654 *
655 * Returns zero on success; non-zero on error.
656 */
657 static int
658 parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
659 unsigned char *data, struct list_head *auth_tok_list,
660 struct ecryptfs_auth_tok **new_auth_tok,
661 size_t *packet_size, size_t max_packet_size)
662 {
663 size_t body_size;
664 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
665 size_t length_size;
666 int rc = 0;
667
668 (*packet_size) = 0;
669 (*new_auth_tok) = NULL;
670 /**
671 *This format is inspired by OpenPGP; see RFC 2440
672 * packet tag 3
673 *
674 * Tag 3 identifier (1 byte)
675 * Max Tag 3 packet size (max 3 bytes)
676 * Version (1 byte)
677 * Cipher code (1 byte)
678 * S2K specifier (1 byte)
679 * Hash identifier (1 byte)
680 * Salt (ECRYPTFS_SALT_SIZE)
681 * Hash iterations (1 byte)
682 * Encrypted key (arbitrary)
683 *
684 * (ECRYPTFS_SALT_SIZE + 7) minimum packet size
685 */
686 if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) {
687 printk(KERN_ERR "Max packet size too large\n");
688 rc = -EINVAL;
689 goto out;
690 }
691 if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) {
692 printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n",
693 ECRYPTFS_TAG_3_PACKET_TYPE);
694 rc = -EINVAL;
695 goto out;
696 }
697 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
698 * at end of function upon failure */
699 auth_tok_list_item =
700 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
701 if (!auth_tok_list_item) {
702 printk(KERN_ERR "Unable to allocate memory\n");
703 rc = -ENOMEM;
704 goto out;
705 }
706 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
707 rc = parse_packet_length(&data[(*packet_size)], &body_size,
708 &length_size);
709 if (rc) {
710 printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n",
711 rc);
712 goto out_free;
713 }
714 if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) {
715 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
716 rc = -EINVAL;
717 goto out_free;
718 }
719 (*packet_size) += length_size;
720 if (unlikely((*packet_size) + body_size > max_packet_size)) {
721 printk(KERN_ERR "Packet size exceeds max\n");
722 rc = -EINVAL;
723 goto out_free;
724 }
725 (*new_auth_tok)->session_key.encrypted_key_size =
726 (body_size - (ECRYPTFS_SALT_SIZE + 5));
727 if (unlikely(data[(*packet_size)++] != 0x04)) {
728 printk(KERN_WARNING "Unknown version number [%d]\n",
729 data[(*packet_size) - 1]);
730 rc = -EINVAL;
731 goto out_free;
732 }
733 ecryptfs_cipher_code_to_string(crypt_stat->cipher,
734 (u16)data[(*packet_size)]);
735 /* A little extra work to differentiate among the AES key
736 * sizes; see RFC2440 */
737 switch(data[(*packet_size)++]) {
738 case RFC2440_CIPHER_AES_192:
739 crypt_stat->key_size = 24;
740 break;
741 default:
742 crypt_stat->key_size =
743 (*new_auth_tok)->session_key.encrypted_key_size;
744 }
745 ecryptfs_init_crypt_ctx(crypt_stat);
746 if (unlikely(data[(*packet_size)++] != 0x03)) {
747 printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
748 rc = -ENOSYS;
749 goto out_free;
750 }
751 /* TODO: finish the hash mapping */
752 switch (data[(*packet_size)++]) {
753 case 0x01: /* See RFC2440 for these numbers and their mappings */
754 /* Choose MD5 */
755 memcpy((*new_auth_tok)->token.password.salt,
756 &data[(*packet_size)], ECRYPTFS_SALT_SIZE);
757 (*packet_size) += ECRYPTFS_SALT_SIZE;
758 /* This conversion was taken straight from RFC2440 */
759 (*new_auth_tok)->token.password.hash_iterations =
760 ((u32) 16 + (data[(*packet_size)] & 15))
761 << ((data[(*packet_size)] >> 4) + 6);
762 (*packet_size)++;
763 /* Friendly reminder:
764 * (*new_auth_tok)->session_key.encrypted_key_size =
765 * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */
766 memcpy((*new_auth_tok)->session_key.encrypted_key,
767 &data[(*packet_size)],
768 (*new_auth_tok)->session_key.encrypted_key_size);
769 (*packet_size) +=
770 (*new_auth_tok)->session_key.encrypted_key_size;
771 (*new_auth_tok)->session_key.flags &=
772 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
773 (*new_auth_tok)->session_key.flags |=
774 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
775 (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */
776 break;
777 default:
778 ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: "
779 "[%d]\n", data[(*packet_size) - 1]);
780 rc = -ENOSYS;
781 goto out_free;
782 }
783 (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD;
784 /* TODO: Parametarize; we might actually want userspace to
785 * decrypt the session key. */
786 (*new_auth_tok)->session_key.flags &=
787 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
788 (*new_auth_tok)->session_key.flags &=
789 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT);
790 list_add(&auth_tok_list_item->list, auth_tok_list);
791 goto out;
792 out_free:
793 (*new_auth_tok) = NULL;
794 memset(auth_tok_list_item, 0,
795 sizeof(struct ecryptfs_auth_tok_list_item));
796 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
797 auth_tok_list_item);
798 out:
799 if (rc)
800 (*packet_size) = 0;
801 return rc;
802 }
803
804 /**
805 * parse_tag_11_packet
806 * @data: The raw bytes of the packet
807 * @contents: This function writes the data contents of the literal
808 * packet into this memory location
809 * @max_contents_bytes: The maximum number of bytes that this function
810 * is allowed to write into contents
811 * @tag_11_contents_size: This function writes the size of the parsed
812 * contents into this memory location; zero on
813 * error
814 * @packet_size: This function writes the size of the parsed packet
815 * into this memory location; zero on error
816 * @max_packet_size: maximum number of bytes to parse
817 *
818 * Returns zero on success; non-zero on error.
819 */
820 static int
821 parse_tag_11_packet(unsigned char *data, unsigned char *contents,
822 size_t max_contents_bytes, size_t *tag_11_contents_size,
823 size_t *packet_size, size_t max_packet_size)
824 {
825 size_t body_size;
826 size_t length_size;
827 int rc = 0;
828
829 (*packet_size) = 0;
830 (*tag_11_contents_size) = 0;
831 /* This format is inspired by OpenPGP; see RFC 2440
832 * packet tag 11
833 *
834 * Tag 11 identifier (1 byte)
835 * Max Tag 11 packet size (max 3 bytes)
836 * Binary format specifier (1 byte)
837 * Filename length (1 byte)
838 * Filename ("_CONSOLE") (8 bytes)
839 * Modification date (4 bytes)
840 * Literal data (arbitrary)
841 *
842 * We need at least 16 bytes of data for the packet to even be
843 * valid.
844 */
845 if (max_packet_size < 16) {
846 printk(KERN_ERR "Maximum packet size too small\n");
847 rc = -EINVAL;
848 goto out;
849 }
850 if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) {
851 printk(KERN_WARNING "Invalid tag 11 packet format\n");
852 rc = -EINVAL;
853 goto out;
854 }
855 rc = parse_packet_length(&data[(*packet_size)], &body_size,
856 &length_size);
857 if (rc) {
858 printk(KERN_WARNING "Invalid tag 11 packet format\n");
859 goto out;
860 }
861 if (body_size < 14) {
862 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
863 rc = -EINVAL;
864 goto out;
865 }
866 (*packet_size) += length_size;
867 (*tag_11_contents_size) = (body_size - 14);
868 if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) {
869 printk(KERN_ERR "Packet size exceeds max\n");
870 rc = -EINVAL;
871 goto out;
872 }
873 if (data[(*packet_size)++] != 0x62) {
874 printk(KERN_WARNING "Unrecognizable packet\n");
875 rc = -EINVAL;
876 goto out;
877 }
878 if (data[(*packet_size)++] != 0x08) {
879 printk(KERN_WARNING "Unrecognizable packet\n");
880 rc = -EINVAL;
881 goto out;
882 }
883 (*packet_size) += 12; /* Ignore filename and modification date */
884 memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size));
885 (*packet_size) += (*tag_11_contents_size);
886 out:
887 if (rc) {
888 (*packet_size) = 0;
889 (*tag_11_contents_size) = 0;
890 }
891 return rc;
892 }
893
894 static int
895 ecryptfs_find_global_auth_tok_for_sig(
896 struct ecryptfs_global_auth_tok **global_auth_tok,
897 struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig)
898 {
899 struct ecryptfs_global_auth_tok *walker;
900 int rc = 0;
901
902 (*global_auth_tok) = NULL;
903 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
904 list_for_each_entry(walker,
905 &mount_crypt_stat->global_auth_tok_list,
906 mount_crypt_stat_list) {
907 if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX) == 0) {
908 (*global_auth_tok) = walker;
909 goto out;
910 }
911 }
912 rc = -EINVAL;
913 out:
914 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
915 return rc;
916 }
917
918 /**
919 * ecryptfs_verify_version
920 * @version: The version number to confirm
921 *
922 * Returns zero on good version; non-zero otherwise
923 */
924 static int ecryptfs_verify_version(u16 version)
925 {
926 int rc = 0;
927 unsigned char major;
928 unsigned char minor;
929
930 major = ((version >> 8) & 0xFF);
931 minor = (version & 0xFF);
932 if (major != ECRYPTFS_VERSION_MAJOR) {
933 ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
934 "Expected [%d]; got [%d]\n",
935 ECRYPTFS_VERSION_MAJOR, major);
936 rc = -EINVAL;
937 goto out;
938 }
939 if (minor != ECRYPTFS_VERSION_MINOR) {
940 ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
941 "Expected [%d]; got [%d]\n",
942 ECRYPTFS_VERSION_MINOR, minor);
943 rc = -EINVAL;
944 goto out;
945 }
946 out:
947 return rc;
948 }
949
950 int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
951 struct ecryptfs_auth_tok **auth_tok,
952 char *sig)
953 {
954 int rc = 0;
955
956 (*auth_tok_key) = request_key(&key_type_user, sig, NULL);
957 if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
958 printk(KERN_ERR "Could not find key with description: [%s]\n",
959 sig);
960 process_request_key_err(PTR_ERR(*auth_tok_key));
961 rc = -EINVAL;
962 goto out;
963 }
964 (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key);
965 if (ecryptfs_verify_version((*auth_tok)->version)) {
966 printk(KERN_ERR
967 "Data structure version mismatch. "
968 "Userspace tools must match eCryptfs "
969 "kernel module with major version [%d] "
970 "and minor version [%d]\n",
971 ECRYPTFS_VERSION_MAJOR,
972 ECRYPTFS_VERSION_MINOR);
973 rc = -EINVAL;
974 goto out;
975 }
976 if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
977 && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
978 printk(KERN_ERR "Invalid auth_tok structure "
979 "returned from key query\n");
980 rc = -EINVAL;
981 goto out;
982 }
983 out:
984 return rc;
985 }
986
987 /**
988 * ecryptfs_find_auth_tok_for_sig
989 * @auth_tok: Set to the matching auth_tok; NULL if not found
990 * @crypt_stat: inode crypt_stat crypto context
991 * @sig: Sig of auth_tok to find
992 *
993 * For now, this function simply looks at the registered auth_tok's
994 * linked off the mount_crypt_stat, so all the auth_toks that can be
995 * used must be registered at mount time. This function could
996 * potentially try a lot harder to find auth_tok's (e.g., by calling
997 * out to ecryptfsd to dynamically retrieve an auth_tok object) so
998 * that static registration of auth_tok's will no longer be necessary.
999 *
1000 * Returns zero on no error; non-zero on error
1001 */
1002 static int
1003 ecryptfs_find_auth_tok_for_sig(
1004 struct ecryptfs_auth_tok **auth_tok,
1005 struct ecryptfs_crypt_stat *crypt_stat, char *sig)
1006 {
1007 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
1008 crypt_stat->mount_crypt_stat;
1009 struct ecryptfs_global_auth_tok *global_auth_tok;
1010 int rc = 0;
1011
1012 (*auth_tok) = NULL;
1013 if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
1014 mount_crypt_stat, sig)) {
1015 struct key *auth_tok_key;
1016
1017 rc = ecryptfs_keyring_auth_tok_for_sig(&auth_tok_key, auth_tok,
1018 sig);
1019 } else
1020 (*auth_tok) = global_auth_tok->global_auth_tok;
1021 return rc;
1022 }
1023
1024 /**
1025 * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok.
1026 * @auth_tok: The passphrase authentication token to use to encrypt the FEK
1027 * @crypt_stat: The cryptographic context
1028 *
1029 * Returns zero on success; non-zero error otherwise
1030 */
1031 static int
1032 decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1033 struct ecryptfs_crypt_stat *crypt_stat)
1034 {
1035 struct scatterlist dst_sg;
1036 struct scatterlist src_sg;
1037 struct mutex *tfm_mutex;
1038 struct blkcipher_desc desc = {
1039 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
1040 };
1041 int rc = 0;
1042
1043 sg_init_table(&dst_sg, 1);
1044 sg_init_table(&src_sg, 1);
1045
1046 if (unlikely(ecryptfs_verbosity > 0)) {
1047 ecryptfs_printk(
1048 KERN_DEBUG, "Session key encryption key (size [%d]):\n",
1049 auth_tok->token.password.session_key_encryption_key_bytes);
1050 ecryptfs_dump_hex(
1051 auth_tok->token.password.session_key_encryption_key,
1052 auth_tok->token.password.session_key_encryption_key_bytes);
1053 }
1054 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
1055 crypt_stat->cipher);
1056 if (unlikely(rc)) {
1057 printk(KERN_ERR "Internal error whilst attempting to get "
1058 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1059 crypt_stat->cipher, rc);
1060 goto out;
1061 }
1062 rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
1063 auth_tok->session_key.encrypted_key_size,
1064 &src_sg, 1);
1065 if (rc != 1) {
1066 printk(KERN_ERR "Internal error whilst attempting to convert "
1067 "auth_tok->session_key.encrypted_key to scatterlist; "
1068 "expected rc = 1; got rc = [%d]. "
1069 "auth_tok->session_key.encrypted_key_size = [%d]\n", rc,
1070 auth_tok->session_key.encrypted_key_size);
1071 goto out;
1072 }
1073 auth_tok->session_key.decrypted_key_size =
1074 auth_tok->session_key.encrypted_key_size;
1075 rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key,
1076 auth_tok->session_key.decrypted_key_size,
1077 &dst_sg, 1);
1078 if (rc != 1) {
1079 printk(KERN_ERR "Internal error whilst attempting to convert "
1080 "auth_tok->session_key.decrypted_key to scatterlist; "
1081 "expected rc = 1; got rc = [%d]\n", rc);
1082 goto out;
1083 }
1084 mutex_lock(tfm_mutex);
1085 rc = crypto_blkcipher_setkey(
1086 desc.tfm, auth_tok->token.password.session_key_encryption_key,
1087 crypt_stat->key_size);
1088 if (unlikely(rc < 0)) {
1089 mutex_unlock(tfm_mutex);
1090 printk(KERN_ERR "Error setting key for crypto context\n");
1091 rc = -EINVAL;
1092 goto out;
1093 }
1094 rc = crypto_blkcipher_decrypt(&desc, &dst_sg, &src_sg,
1095 auth_tok->session_key.encrypted_key_size);
1096 mutex_unlock(tfm_mutex);
1097 if (unlikely(rc)) {
1098 printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
1099 goto out;
1100 }
1101 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1102 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1103 auth_tok->session_key.decrypted_key_size);
1104 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1105 if (unlikely(ecryptfs_verbosity > 0)) {
1106 ecryptfs_printk(KERN_DEBUG, "FEK of size [%d]:\n",
1107 crypt_stat->key_size);
1108 ecryptfs_dump_hex(crypt_stat->key,
1109 crypt_stat->key_size);
1110 }
1111 out:
1112 return rc;
1113 }
1114
1115 /**
1116 * ecryptfs_parse_packet_set
1117 * @crypt_stat: The cryptographic context
1118 * @src: Virtual address of region of memory containing the packets
1119 * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set
1120 *
1121 * Get crypt_stat to have the file's session key if the requisite key
1122 * is available to decrypt the session key.
1123 *
1124 * Returns Zero if a valid authentication token was retrieved and
1125 * processed; negative value for file not encrypted or for error
1126 * conditions.
1127 */
1128 int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
1129 unsigned char *src,
1130 struct dentry *ecryptfs_dentry)
1131 {
1132 size_t i = 0;
1133 size_t found_auth_tok;
1134 size_t next_packet_is_auth_tok_packet;
1135 struct list_head auth_tok_list;
1136 struct ecryptfs_auth_tok *matching_auth_tok;
1137 struct ecryptfs_auth_tok *candidate_auth_tok;
1138 char *candidate_auth_tok_sig;
1139 size_t packet_size;
1140 struct ecryptfs_auth_tok *new_auth_tok;
1141 unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE];
1142 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1143 size_t tag_11_contents_size;
1144 size_t tag_11_packet_size;
1145 int rc = 0;
1146
1147 INIT_LIST_HEAD(&auth_tok_list);
1148 /* Parse the header to find as many packets as we can; these will be
1149 * added the our &auth_tok_list */
1150 next_packet_is_auth_tok_packet = 1;
1151 while (next_packet_is_auth_tok_packet) {
1152 size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i);
1153
1154 switch (src[i]) {
1155 case ECRYPTFS_TAG_3_PACKET_TYPE:
1156 rc = parse_tag_3_packet(crypt_stat,
1157 (unsigned char *)&src[i],
1158 &auth_tok_list, &new_auth_tok,
1159 &packet_size, max_packet_size);
1160 if (rc) {
1161 ecryptfs_printk(KERN_ERR, "Error parsing "
1162 "tag 3 packet\n");
1163 rc = -EIO;
1164 goto out_wipe_list;
1165 }
1166 i += packet_size;
1167 rc = parse_tag_11_packet((unsigned char *)&src[i],
1168 sig_tmp_space,
1169 ECRYPTFS_SIG_SIZE,
1170 &tag_11_contents_size,
1171 &tag_11_packet_size,
1172 max_packet_size);
1173 if (rc) {
1174 ecryptfs_printk(KERN_ERR, "No valid "
1175 "(ecryptfs-specific) literal "
1176 "packet containing "
1177 "authentication token "
1178 "signature found after "
1179 "tag 3 packet\n");
1180 rc = -EIO;
1181 goto out_wipe_list;
1182 }
1183 i += tag_11_packet_size;
1184 if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) {
1185 ecryptfs_printk(KERN_ERR, "Expected "
1186 "signature of size [%d]; "
1187 "read size [%d]\n",
1188 ECRYPTFS_SIG_SIZE,
1189 tag_11_contents_size);
1190 rc = -EIO;
1191 goto out_wipe_list;
1192 }
1193 ecryptfs_to_hex(new_auth_tok->token.password.signature,
1194 sig_tmp_space, tag_11_contents_size);
1195 new_auth_tok->token.password.signature[
1196 ECRYPTFS_PASSWORD_SIG_SIZE] = '\0';
1197 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
1198 break;
1199 case ECRYPTFS_TAG_1_PACKET_TYPE:
1200 rc = parse_tag_1_packet(crypt_stat,
1201 (unsigned char *)&src[i],
1202 &auth_tok_list, &new_auth_tok,
1203 &packet_size, max_packet_size);
1204 if (rc) {
1205 ecryptfs_printk(KERN_ERR, "Error parsing "
1206 "tag 1 packet\n");
1207 rc = -EIO;
1208 goto out_wipe_list;
1209 }
1210 i += packet_size;
1211 crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
1212 break;
1213 case ECRYPTFS_TAG_11_PACKET_TYPE:
1214 ecryptfs_printk(KERN_WARNING, "Invalid packet set "
1215 "(Tag 11 not allowed by itself)\n");
1216 rc = -EIO;
1217 goto out_wipe_list;
1218 break;
1219 default:
1220 ecryptfs_printk(KERN_DEBUG, "No packet at offset "
1221 "[%d] of the file header; hex value of "
1222 "character is [0x%.2x]\n", i, src[i]);
1223 next_packet_is_auth_tok_packet = 0;
1224 }
1225 }
1226 if (list_empty(&auth_tok_list)) {
1227 printk(KERN_ERR "The lower file appears to be a non-encrypted "
1228 "eCryptfs file; this is not supported in this version "
1229 "of the eCryptfs kernel module\n");
1230 rc = -EINVAL;
1231 goto out;
1232 }
1233 /* auth_tok_list contains the set of authentication tokens
1234 * parsed from the metadata. We need to find a matching
1235 * authentication token that has the secret component(s)
1236 * necessary to decrypt the EFEK in the auth_tok parsed from
1237 * the metadata. There may be several potential matches, but
1238 * just one will be sufficient to decrypt to get the FEK. */
1239 find_next_matching_auth_tok:
1240 found_auth_tok = 0;
1241 list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) {
1242 candidate_auth_tok = &auth_tok_list_item->auth_tok;
1243 if (unlikely(ecryptfs_verbosity > 0)) {
1244 ecryptfs_printk(KERN_DEBUG,
1245 "Considering cadidate auth tok:\n");
1246 ecryptfs_dump_auth_tok(candidate_auth_tok);
1247 }
1248 rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig,
1249 candidate_auth_tok);
1250 if (rc) {
1251 printk(KERN_ERR
1252 "Unrecognized candidate auth tok type: [%d]\n",
1253 candidate_auth_tok->token_type);
1254 rc = -EINVAL;
1255 goto out_wipe_list;
1256 }
1257 ecryptfs_find_auth_tok_for_sig(&matching_auth_tok, crypt_stat,
1258 candidate_auth_tok_sig);
1259 if (matching_auth_tok) {
1260 found_auth_tok = 1;
1261 goto found_matching_auth_tok;
1262 }
1263 }
1264 if (!found_auth_tok) {
1265 ecryptfs_printk(KERN_ERR, "Could not find a usable "
1266 "authentication token\n");
1267 rc = -EIO;
1268 goto out_wipe_list;
1269 }
1270 found_matching_auth_tok:
1271 if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
1272 memcpy(&(candidate_auth_tok->token.private_key),
1273 &(matching_auth_tok->token.private_key),
1274 sizeof(struct ecryptfs_private_key));
1275 rc = decrypt_pki_encrypted_session_key(candidate_auth_tok,
1276 crypt_stat);
1277 } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
1278 memcpy(&(candidate_auth_tok->token.password),
1279 &(matching_auth_tok->token.password),
1280 sizeof(struct ecryptfs_password));
1281 rc = decrypt_passphrase_encrypted_session_key(
1282 candidate_auth_tok, crypt_stat);
1283 }
1284 if (rc) {
1285 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1286
1287 ecryptfs_printk(KERN_WARNING, "Error decrypting the "
1288 "session key for authentication token with sig "
1289 "[%.*s]; rc = [%d]. Removing auth tok "
1290 "candidate from the list and searching for "
1291 "the next match.\n", candidate_auth_tok_sig,
1292 ECRYPTFS_SIG_SIZE_HEX, rc);
1293 list_for_each_entry_safe(auth_tok_list_item,
1294 auth_tok_list_item_tmp,
1295 &auth_tok_list, list) {
1296 if (candidate_auth_tok
1297 == &auth_tok_list_item->auth_tok) {
1298 list_del(&auth_tok_list_item->list);
1299 kmem_cache_free(
1300 ecryptfs_auth_tok_list_item_cache,
1301 auth_tok_list_item);
1302 goto find_next_matching_auth_tok;
1303 }
1304 }
1305 BUG();
1306 }
1307 rc = ecryptfs_compute_root_iv(crypt_stat);
1308 if (rc) {
1309 ecryptfs_printk(KERN_ERR, "Error computing "
1310 "the root IV\n");
1311 goto out_wipe_list;
1312 }
1313 rc = ecryptfs_init_crypt_ctx(crypt_stat);
1314 if (rc) {
1315 ecryptfs_printk(KERN_ERR, "Error initializing crypto "
1316 "context for cipher [%s]; rc = [%d]\n",
1317 crypt_stat->cipher, rc);
1318 }
1319 out_wipe_list:
1320 wipe_auth_tok_list(&auth_tok_list);
1321 out:
1322 return rc;
1323 }
1324
1325 static int
1326 pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
1327 struct ecryptfs_crypt_stat *crypt_stat,
1328 struct ecryptfs_key_record *key_rec)
1329 {
1330 struct ecryptfs_msg_ctx *msg_ctx = NULL;
1331 char *netlink_payload;
1332 size_t netlink_payload_length;
1333 struct ecryptfs_message *msg;
1334 int rc;
1335
1336 rc = write_tag_66_packet(auth_tok->token.private_key.signature,
1337 ecryptfs_code_for_cipher_string(crypt_stat),
1338 crypt_stat, &netlink_payload,
1339 &netlink_payload_length);
1340 if (rc) {
1341 ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
1342 goto out;
1343 }
1344 rc = ecryptfs_send_message(ecryptfs_transport, netlink_payload,
1345 netlink_payload_length, &msg_ctx);
1346 if (rc) {
1347 ecryptfs_printk(KERN_ERR, "Error sending netlink message\n");
1348 goto out;
1349 }
1350 rc = ecryptfs_wait_for_response(msg_ctx, &msg);
1351 if (rc) {
1352 ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet "
1353 "from the user space daemon\n");
1354 rc = -EIO;
1355 goto out;
1356 }
1357 rc = parse_tag_67_packet(key_rec, msg);
1358 if (rc)
1359 ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n");
1360 kfree(msg);
1361 out:
1362 if (netlink_payload)
1363 kfree(netlink_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 ecryptfs_printk(KERN_ERR, "Failed to encrypt session key "
1409 "via a pki");
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 = write_packet_length(&dest[(*packet_size)], (max_packet_size - 4),
1434 &packet_size_length);
1435 if (rc) {
1436 ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet "
1437 "header; cannot generate packet length\n");
1438 goto out;
1439 }
1440 (*packet_size) += packet_size_length;
1441 dest[(*packet_size)++] = 0x03; /* version 3 */
1442 memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE);
1443 (*packet_size) += ECRYPTFS_SIG_SIZE;
1444 dest[(*packet_size)++] = RFC2440_CIPHER_RSA;
1445 memcpy(&dest[(*packet_size)], key_rec->enc_key,
1446 key_rec->enc_key_size);
1447 (*packet_size) += key_rec->enc_key_size;
1448 out:
1449 if (rc)
1450 (*packet_size) = 0;
1451 else
1452 (*remaining_bytes) -= (*packet_size);
1453 return rc;
1454 }
1455
1456 /**
1457 * write_tag_11_packet
1458 * @dest: Target into which Tag 11 packet is to be written
1459 * @remaining_bytes: Maximum packet length
1460 * @contents: Byte array of contents to copy in
1461 * @contents_length: Number of bytes in contents
1462 * @packet_length: Length of the Tag 11 packet written; zero on error
1463 *
1464 * Returns zero on success; non-zero on error.
1465 */
1466 static int
1467 write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents,
1468 size_t contents_length, size_t *packet_length)
1469 {
1470 size_t packet_size_length;
1471 size_t max_packet_size;
1472 int rc = 0;
1473
1474 (*packet_length) = 0;
1475 /* This format is inspired by OpenPGP; see RFC 2440
1476 * packet tag 11 */
1477 max_packet_size = (1 /* Tag 11 identifier */
1478 + 3 /* Max Tag 11 packet size */
1479 + 1 /* Binary format specifier */
1480 + 1 /* Filename length */
1481 + 8 /* Filename ("_CONSOLE") */
1482 + 4 /* Modification date */
1483 + contents_length); /* Literal data */
1484 if (max_packet_size > (*remaining_bytes)) {
1485 printk(KERN_ERR "Packet length larger than maximum allowable; "
1486 "need up to [%td] bytes, but there are only [%td] "
1487 "available\n", max_packet_size, (*remaining_bytes));
1488 rc = -EINVAL;
1489 goto out;
1490 }
1491 dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE;
1492 rc = write_packet_length(&dest[(*packet_length)],
1493 (max_packet_size - 4), &packet_size_length);
1494 if (rc) {
1495 printk(KERN_ERR "Error generating tag 11 packet header; cannot "
1496 "generate packet length. rc = [%d]\n", rc);
1497 goto out;
1498 }
1499 (*packet_length) += packet_size_length;
1500 dest[(*packet_length)++] = 0x62; /* binary data format specifier */
1501 dest[(*packet_length)++] = 8;
1502 memcpy(&dest[(*packet_length)], "_CONSOLE", 8);
1503 (*packet_length) += 8;
1504 memset(&dest[(*packet_length)], 0x00, 4);
1505 (*packet_length) += 4;
1506 memcpy(&dest[(*packet_length)], contents, contents_length);
1507 (*packet_length) += contents_length;
1508 out:
1509 if (rc)
1510 (*packet_length) = 0;
1511 else
1512 (*remaining_bytes) -= (*packet_length);
1513 return rc;
1514 }
1515
1516 /**
1517 * write_tag_3_packet
1518 * @dest: Buffer into which to write the packet
1519 * @remaining_bytes: Maximum number of bytes that can be written
1520 * @auth_tok: Authentication token
1521 * @crypt_stat: The cryptographic context
1522 * @key_rec: encrypted key
1523 * @packet_size: This function will write the number of bytes that end
1524 * up constituting the packet; set to zero on error
1525 *
1526 * Returns zero on success; non-zero on error.
1527 */
1528 static int
1529 write_tag_3_packet(char *dest, size_t *remaining_bytes,
1530 struct ecryptfs_auth_tok *auth_tok,
1531 struct ecryptfs_crypt_stat *crypt_stat,
1532 struct ecryptfs_key_record *key_rec, size_t *packet_size)
1533 {
1534 size_t i;
1535 size_t encrypted_session_key_valid = 0;
1536 char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
1537 struct scatterlist dst_sg;
1538 struct scatterlist src_sg;
1539 struct mutex *tfm_mutex = NULL;
1540 size_t cipher_code;
1541 size_t packet_size_length;
1542 size_t max_packet_size;
1543 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
1544 crypt_stat->mount_crypt_stat;
1545 struct blkcipher_desc desc = {
1546 .tfm = NULL,
1547 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
1548 };
1549 int rc = 0;
1550
1551 (*packet_size) = 0;
1552 ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
1553 ECRYPTFS_SIG_SIZE);
1554 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
1555 crypt_stat->cipher);
1556 if (unlikely(rc)) {
1557 printk(KERN_ERR "Internal error whilst attempting to get "
1558 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1559 crypt_stat->cipher, rc);
1560 goto out;
1561 }
1562 if (mount_crypt_stat->global_default_cipher_key_size == 0) {
1563 struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm);
1564
1565 printk(KERN_WARNING "No key size specified at mount; "
1566 "defaulting to [%d]\n", alg->max_keysize);
1567 mount_crypt_stat->global_default_cipher_key_size =
1568 alg->max_keysize;
1569 }
1570 if (crypt_stat->key_size == 0)
1571 crypt_stat->key_size =
1572 mount_crypt_stat->global_default_cipher_key_size;
1573 if (auth_tok->session_key.encrypted_key_size == 0)
1574 auth_tok->session_key.encrypted_key_size =
1575 crypt_stat->key_size;
1576 if (crypt_stat->key_size == 24
1577 && strcmp("aes", crypt_stat->cipher) == 0) {
1578 memset((crypt_stat->key + 24), 0, 8);
1579 auth_tok->session_key.encrypted_key_size = 32;
1580 } else
1581 auth_tok->session_key.encrypted_key_size = crypt_stat->key_size;
1582 key_rec->enc_key_size =
1583 auth_tok->session_key.encrypted_key_size;
1584 encrypted_session_key_valid = 0;
1585 for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++)
1586 encrypted_session_key_valid |=
1587 auth_tok->session_key.encrypted_key[i];
1588 if (encrypted_session_key_valid) {
1589 ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; "
1590 "using auth_tok->session_key.encrypted_key, "
1591 "where key_rec->enc_key_size = [%d]\n",
1592 key_rec->enc_key_size);
1593 memcpy(key_rec->enc_key,
1594 auth_tok->session_key.encrypted_key,
1595 key_rec->enc_key_size);
1596 goto encrypted_session_key_set;
1597 }
1598 if (auth_tok->token.password.flags &
1599 ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) {
1600 ecryptfs_printk(KERN_DEBUG, "Using previously generated "
1601 "session key encryption key of size [%d]\n",
1602 auth_tok->token.password.
1603 session_key_encryption_key_bytes);
1604 memcpy(session_key_encryption_key,
1605 auth_tok->token.password.session_key_encryption_key,
1606 crypt_stat->key_size);
1607 ecryptfs_printk(KERN_DEBUG,
1608 "Cached session key " "encryption key: \n");
1609 if (ecryptfs_verbosity > 0)
1610 ecryptfs_dump_hex(session_key_encryption_key, 16);
1611 }
1612 if (unlikely(ecryptfs_verbosity > 0)) {
1613 ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n");
1614 ecryptfs_dump_hex(session_key_encryption_key, 16);
1615 }
1616 rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size,
1617 &src_sg, 1);
1618 if (rc != 1) {
1619 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
1620 "for crypt_stat session key; expected rc = 1; "
1621 "got rc = [%d]. key_rec->enc_key_size = [%d]\n",
1622 rc, key_rec->enc_key_size);
1623 rc = -ENOMEM;
1624 goto out;
1625 }
1626 rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size,
1627 &dst_sg, 1);
1628 if (rc != 1) {
1629 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
1630 "for crypt_stat encrypted session key; "
1631 "expected rc = 1; got rc = [%d]. "
1632 "key_rec->enc_key_size = [%d]\n", rc,
1633 key_rec->enc_key_size);
1634 rc = -ENOMEM;
1635 goto out;
1636 }
1637 mutex_lock(tfm_mutex);
1638 rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key,
1639 crypt_stat->key_size);
1640 if (rc < 0) {
1641 mutex_unlock(tfm_mutex);
1642 ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
1643 "context; rc = [%d]\n", rc);
1644 goto out;
1645 }
1646 rc = 0;
1647 ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n",
1648 crypt_stat->key_size);
1649 rc = crypto_blkcipher_encrypt(&desc, &dst_sg, &src_sg,
1650 (*key_rec).enc_key_size);
1651 mutex_unlock(tfm_mutex);
1652 if (rc) {
1653 printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc);
1654 goto out;
1655 }
1656 ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
1657 if (ecryptfs_verbosity > 0) {
1658 ecryptfs_printk(KERN_DEBUG, "EFEK of size [%d]:\n",
1659 key_rec->enc_key_size);
1660 ecryptfs_dump_hex(key_rec->enc_key,
1661 key_rec->enc_key_size);
1662 }
1663 encrypted_session_key_set:
1664 /* This format is inspired by OpenPGP; see RFC 2440
1665 * packet tag 3 */
1666 max_packet_size = (1 /* Tag 3 identifier */
1667 + 3 /* Max Tag 3 packet size */
1668 + 1 /* Version */
1669 + 1 /* Cipher code */
1670 + 1 /* S2K specifier */
1671 + 1 /* Hash identifier */
1672 + ECRYPTFS_SALT_SIZE /* Salt */
1673 + 1 /* Hash iterations */
1674 + key_rec->enc_key_size); /* Encrypted key size */
1675 if (max_packet_size > (*remaining_bytes)) {
1676 printk(KERN_ERR "Packet too large; need up to [%td] bytes, but "
1677 "there are only [%td] available\n", max_packet_size,
1678 (*remaining_bytes));
1679 rc = -EINVAL;
1680 goto out;
1681 }
1682 dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE;
1683 /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3)
1684 * to get the number of octets in the actual Tag 3 packet */
1685 rc = write_packet_length(&dest[(*packet_size)], (max_packet_size - 4),
1686 &packet_size_length);
1687 if (rc) {
1688 printk(KERN_ERR "Error generating tag 3 packet header; cannot "
1689 "generate packet length. rc = [%d]\n", rc);
1690 goto out;
1691 }
1692 (*packet_size) += packet_size_length;
1693 dest[(*packet_size)++] = 0x04; /* version 4 */
1694 /* TODO: Break from RFC2440 so that arbitrary ciphers can be
1695 * specified with strings */
1696 cipher_code = ecryptfs_code_for_cipher_string(crypt_stat);
1697 if (cipher_code == 0) {
1698 ecryptfs_printk(KERN_WARNING, "Unable to generate code for "
1699 "cipher [%s]\n", crypt_stat->cipher);
1700 rc = -EINVAL;
1701 goto out;
1702 }
1703 dest[(*packet_size)++] = cipher_code;
1704 dest[(*packet_size)++] = 0x03; /* S2K */
1705 dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */
1706 memcpy(&dest[(*packet_size)], auth_tok->token.password.salt,
1707 ECRYPTFS_SALT_SIZE);
1708 (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */
1709 dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */
1710 memcpy(&dest[(*packet_size)], key_rec->enc_key,
1711 key_rec->enc_key_size);
1712 (*packet_size) += key_rec->enc_key_size;
1713 out:
1714 if (rc)
1715 (*packet_size) = 0;
1716 else
1717 (*remaining_bytes) -= (*packet_size);
1718 return rc;
1719 }
1720
1721 struct kmem_cache *ecryptfs_key_record_cache;
1722
1723 /**
1724 * ecryptfs_generate_key_packet_set
1725 * @dest_base: Virtual address from which to write the key record set
1726 * @crypt_stat: The cryptographic context from which the
1727 * authentication tokens will be retrieved
1728 * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat
1729 * for the global parameters
1730 * @len: The amount written
1731 * @max: The maximum amount of data allowed to be written
1732 *
1733 * Generates a key packet set and writes it to the virtual address
1734 * passed in.
1735 *
1736 * Returns zero on success; non-zero on error.
1737 */
1738 int
1739 ecryptfs_generate_key_packet_set(char *dest_base,
1740 struct ecryptfs_crypt_stat *crypt_stat,
1741 struct dentry *ecryptfs_dentry, size_t *len,
1742 size_t max)
1743 {
1744 struct ecryptfs_auth_tok *auth_tok;
1745 struct ecryptfs_global_auth_tok *global_auth_tok;
1746 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
1747 &ecryptfs_superblock_to_private(
1748 ecryptfs_dentry->d_sb)->mount_crypt_stat;
1749 size_t written;
1750 struct ecryptfs_key_record *key_rec;
1751 struct ecryptfs_key_sig *key_sig;
1752 int rc = 0;
1753
1754 (*len) = 0;
1755 mutex_lock(&crypt_stat->keysig_list_mutex);
1756 key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL);
1757 if (!key_rec) {
1758 rc = -ENOMEM;
1759 goto out;
1760 }
1761 list_for_each_entry(key_sig, &crypt_stat->keysig_list,
1762 crypt_stat_list) {
1763 memset(key_rec, 0, sizeof(*key_rec));
1764 rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
1765 mount_crypt_stat,
1766 key_sig->keysig);
1767 if (rc) {
1768 printk(KERN_ERR "Error attempting to get the global "
1769 "auth_tok; rc = [%d]\n", rc);
1770 goto out_free;
1771 }
1772 if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) {
1773 printk(KERN_WARNING
1774 "Skipping invalid auth tok with sig = [%s]\n",
1775 global_auth_tok->sig);
1776 continue;
1777 }
1778 auth_tok = global_auth_tok->global_auth_tok;
1779 if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
1780 rc = write_tag_3_packet((dest_base + (*len)),
1781 &max, auth_tok,
1782 crypt_stat, key_rec,
1783 &written);
1784 if (rc) {
1785 ecryptfs_printk(KERN_WARNING, "Error "
1786 "writing tag 3 packet\n");
1787 goto out_free;
1788 }
1789 (*len) += written;
1790 /* Write auth tok signature packet */
1791 rc = write_tag_11_packet((dest_base + (*len)), &max,
1792 key_rec->sig,
1793 ECRYPTFS_SIG_SIZE, &written);
1794 if (rc) {
1795 ecryptfs_printk(KERN_ERR, "Error writing "
1796 "auth tok signature packet\n");
1797 goto out_free;
1798 }
1799 (*len) += written;
1800 } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
1801 rc = write_tag_1_packet(dest_base + (*len),
1802 &max, auth_tok,
1803 crypt_stat, key_rec, &written);
1804 if (rc) {
1805 ecryptfs_printk(KERN_WARNING, "Error "
1806 "writing tag 1 packet\n");
1807 goto out_free;
1808 }
1809 (*len) += written;
1810 } else {
1811 ecryptfs_printk(KERN_WARNING, "Unsupported "
1812 "authentication token type\n");
1813 rc = -EINVAL;
1814 goto out_free;
1815 }
1816 }
1817 if (likely(max > 0)) {
1818 dest_base[(*len)] = 0x00;
1819 } else {
1820 ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n");
1821 rc = -EIO;
1822 }
1823 out_free:
1824 kmem_cache_free(ecryptfs_key_record_cache, key_rec);
1825 out:
1826 if (rc)
1827 (*len) = 0;
1828 mutex_unlock(&crypt_stat->keysig_list_mutex);
1829 return rc;
1830 }
1831
1832 struct kmem_cache *ecryptfs_key_sig_cache;
1833
1834 int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig)
1835 {
1836 struct ecryptfs_key_sig *new_key_sig;
1837 int rc = 0;
1838
1839 new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL);
1840 if (!new_key_sig) {
1841 rc = -ENOMEM;
1842 printk(KERN_ERR
1843 "Error allocating from ecryptfs_key_sig_cache\n");
1844 goto out;
1845 }
1846 memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
1847 mutex_lock(&crypt_stat->keysig_list_mutex);
1848 list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
1849 mutex_unlock(&crypt_stat->keysig_list_mutex);
1850 out:
1851 return rc;
1852 }
1853
1854 struct kmem_cache *ecryptfs_global_auth_tok_cache;
1855
1856 int
1857 ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
1858 char *sig)
1859 {
1860 struct ecryptfs_global_auth_tok *new_auth_tok;
1861 int rc = 0;
1862
1863 new_auth_tok = kmem_cache_alloc(ecryptfs_global_auth_tok_cache,
1864 GFP_KERNEL);
1865 if (!new_auth_tok) {
1866 rc = -ENOMEM;
1867 printk(KERN_ERR "Error allocating from "
1868 "ecryptfs_global_auth_tok_cache\n");
1869 goto out;
1870 }
1871 memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX);
1872 new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
1873 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
1874 list_add(&new_auth_tok->mount_crypt_stat_list,
1875 &mount_crypt_stat->global_auth_tok_list);
1876 mount_crypt_stat->num_global_auth_toks++;
1877 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
1878 out:
1879 return rc;
1880 }
1881
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