1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * eCryptfs: Linux filesystem encryption layer |
4 | * In-kernel key management code. Includes functions to parse and |
5 | * write authentication token-related packets with the underlying |
6 | * file. |
7 | * |
8 | * Copyright (C) 2004-2006 International Business Machines Corp. |
9 | * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com> |
10 | * Michael C. Thompson <mcthomps@us.ibm.com> |
11 | * Trevor S. Highland <trevor.highland@gmail.com> |
12 | */ |
13 | |
14 | #include <crypto/hash.h> |
15 | #include <crypto/skcipher.h> |
16 | #include <linux/string.h> |
17 | #include <linux/pagemap.h> |
18 | #include <linux/key.h> |
19 | #include <linux/random.h> |
20 | #include <linux/scatterlist.h> |
21 | #include <linux/slab.h> |
22 | #include "ecryptfs_kernel.h" |
23 | |
24 | /* |
25 | * request_key returned an error instead of a valid key address; |
26 | * determine the type of error, make appropriate log entries, and |
27 | * return an error code. |
28 | */ |
29 | static int process_request_key_err(long err_code) |
30 | { |
31 | int rc = 0; |
32 | |
33 | switch (err_code) { |
34 | case -ENOKEY: |
35 | ecryptfs_printk(KERN_WARNING, "No key\n" ); |
36 | rc = -ENOENT; |
37 | break; |
38 | case -EKEYEXPIRED: |
39 | ecryptfs_printk(KERN_WARNING, "Key expired\n" ); |
40 | rc = -ETIME; |
41 | break; |
42 | case -EKEYREVOKED: |
43 | ecryptfs_printk(KERN_WARNING, "Key revoked\n" ); |
44 | rc = -EINVAL; |
45 | break; |
46 | default: |
47 | ecryptfs_printk(KERN_WARNING, "Unknown error code: " |
48 | "[0x%.16lx]\n" , err_code); |
49 | rc = -EINVAL; |
50 | } |
51 | return rc; |
52 | } |
53 | |
54 | static int process_find_global_auth_tok_for_sig_err(int err_code) |
55 | { |
56 | int rc = err_code; |
57 | |
58 | switch (err_code) { |
59 | case -ENOENT: |
60 | ecryptfs_printk(KERN_WARNING, "Missing auth tok\n" ); |
61 | break; |
62 | case -EINVAL: |
63 | ecryptfs_printk(KERN_WARNING, "Invalid auth tok\n" ); |
64 | break; |
65 | default: |
66 | rc = process_request_key_err(err_code); |
67 | break; |
68 | } |
69 | return rc; |
70 | } |
71 | |
72 | /** |
73 | * ecryptfs_parse_packet_length |
74 | * @data: Pointer to memory containing length at offset |
75 | * @size: This function writes the decoded size to this memory |
76 | * address; zero on error |
77 | * @length_size: The number of bytes occupied by the encoded length |
78 | * |
79 | * Returns zero on success; non-zero on error |
80 | */ |
81 | int ecryptfs_parse_packet_length(unsigned char *data, size_t *size, |
82 | size_t *length_size) |
83 | { |
84 | int rc = 0; |
85 | |
86 | (*length_size) = 0; |
87 | (*size) = 0; |
88 | if (data[0] < 192) { |
89 | /* One-byte length */ |
90 | (*size) = data[0]; |
91 | (*length_size) = 1; |
92 | } else if (data[0] < 224) { |
93 | /* Two-byte length */ |
94 | (*size) = (data[0] - 192) * 256; |
95 | (*size) += data[1] + 192; |
96 | (*length_size) = 2; |
97 | } else if (data[0] == 255) { |
98 | /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */ |
99 | ecryptfs_printk(KERN_ERR, "Five-byte packet length not " |
100 | "supported\n" ); |
101 | rc = -EINVAL; |
102 | goto out; |
103 | } else { |
104 | ecryptfs_printk(KERN_ERR, "Error parsing packet length\n" ); |
105 | rc = -EINVAL; |
106 | goto out; |
107 | } |
108 | out: |
109 | return rc; |
110 | } |
111 | |
112 | /** |
113 | * ecryptfs_write_packet_length |
114 | * @dest: The byte array target into which to write the length. Must |
115 | * have at least ECRYPTFS_MAX_PKT_LEN_SIZE bytes allocated. |
116 | * @size: The length to write. |
117 | * @packet_size_length: The number of bytes used to encode the packet |
118 | * length is written to this address. |
119 | * |
120 | * Returns zero on success; non-zero on error. |
121 | */ |
122 | int ecryptfs_write_packet_length(char *dest, size_t size, |
123 | size_t *packet_size_length) |
124 | { |
125 | int rc = 0; |
126 | |
127 | if (size < 192) { |
128 | dest[0] = size; |
129 | (*packet_size_length) = 1; |
130 | } else if (size < 65536) { |
131 | dest[0] = (((size - 192) / 256) + 192); |
132 | dest[1] = ((size - 192) % 256); |
133 | (*packet_size_length) = 2; |
134 | } else { |
135 | /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */ |
136 | rc = -EINVAL; |
137 | ecryptfs_printk(KERN_WARNING, |
138 | "Unsupported packet size: [%zd]\n" , size); |
139 | } |
140 | return rc; |
141 | } |
142 | |
143 | static int |
144 | write_tag_64_packet(char *signature, struct ecryptfs_session_key *session_key, |
145 | char **packet, size_t *packet_len) |
146 | { |
147 | size_t i = 0; |
148 | size_t data_len; |
149 | size_t packet_size_len; |
150 | char *message; |
151 | int rc; |
152 | |
153 | /* |
154 | * ***** TAG 64 Packet Format ***** |
155 | * | Content Type | 1 byte | |
156 | * | Key Identifier Size | 1 or 2 bytes | |
157 | * | Key Identifier | arbitrary | |
158 | * | Encrypted File Encryption Key Size | 1 or 2 bytes | |
159 | * | Encrypted File Encryption Key | arbitrary | |
160 | */ |
161 | data_len = (5 + ECRYPTFS_SIG_SIZE_HEX |
162 | + session_key->encrypted_key_size); |
163 | *packet = kmalloc(size: data_len, GFP_KERNEL); |
164 | message = *packet; |
165 | if (!message) { |
166 | ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n" ); |
167 | rc = -ENOMEM; |
168 | goto out; |
169 | } |
170 | message[i++] = ECRYPTFS_TAG_64_PACKET_TYPE; |
171 | rc = ecryptfs_write_packet_length(dest: &message[i], ECRYPTFS_SIG_SIZE_HEX, |
172 | packet_size_length: &packet_size_len); |
173 | if (rc) { |
174 | ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet " |
175 | "header; cannot generate packet length\n" ); |
176 | goto out; |
177 | } |
178 | i += packet_size_len; |
179 | memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX); |
180 | i += ECRYPTFS_SIG_SIZE_HEX; |
181 | rc = ecryptfs_write_packet_length(dest: &message[i], |
182 | size: session_key->encrypted_key_size, |
183 | packet_size_length: &packet_size_len); |
184 | if (rc) { |
185 | ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet " |
186 | "header; cannot generate packet length\n" ); |
187 | goto out; |
188 | } |
189 | i += packet_size_len; |
190 | memcpy(&message[i], session_key->encrypted_key, |
191 | session_key->encrypted_key_size); |
192 | i += session_key->encrypted_key_size; |
193 | *packet_len = i; |
194 | out: |
195 | return rc; |
196 | } |
197 | |
198 | static int |
199 | parse_tag_65_packet(struct ecryptfs_session_key *session_key, u8 *cipher_code, |
200 | struct ecryptfs_message *msg) |
201 | { |
202 | size_t i = 0; |
203 | char *data; |
204 | size_t data_len; |
205 | size_t m_size; |
206 | size_t message_len; |
207 | u16 checksum = 0; |
208 | u16 expected_checksum = 0; |
209 | int rc; |
210 | |
211 | /* |
212 | * ***** TAG 65 Packet Format ***** |
213 | * | Content Type | 1 byte | |
214 | * | Status Indicator | 1 byte | |
215 | * | File Encryption Key Size | 1 or 2 bytes | |
216 | * | File Encryption Key | arbitrary | |
217 | */ |
218 | message_len = msg->data_len; |
219 | data = msg->data; |
220 | if (message_len < 4) { |
221 | rc = -EIO; |
222 | goto out; |
223 | } |
224 | if (data[i++] != ECRYPTFS_TAG_65_PACKET_TYPE) { |
225 | ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_65\n" ); |
226 | rc = -EIO; |
227 | goto out; |
228 | } |
229 | if (data[i++]) { |
230 | ecryptfs_printk(KERN_ERR, "Status indicator has non-zero value " |
231 | "[%d]\n" , data[i-1]); |
232 | rc = -EIO; |
233 | goto out; |
234 | } |
235 | rc = ecryptfs_parse_packet_length(data: &data[i], size: &m_size, length_size: &data_len); |
236 | if (rc) { |
237 | ecryptfs_printk(KERN_WARNING, "Error parsing packet length; " |
238 | "rc = [%d]\n" , rc); |
239 | goto out; |
240 | } |
241 | i += data_len; |
242 | if (message_len < (i + m_size)) { |
243 | ecryptfs_printk(KERN_ERR, "The message received from ecryptfsd " |
244 | "is shorter than expected\n" ); |
245 | rc = -EIO; |
246 | goto out; |
247 | } |
248 | if (m_size < 3) { |
249 | ecryptfs_printk(KERN_ERR, |
250 | "The decrypted key is not long enough to " |
251 | "include a cipher code and checksum\n" ); |
252 | rc = -EIO; |
253 | goto out; |
254 | } |
255 | *cipher_code = data[i++]; |
256 | /* The decrypted key includes 1 byte cipher code and 2 byte checksum */ |
257 | session_key->decrypted_key_size = m_size - 3; |
258 | if (session_key->decrypted_key_size > ECRYPTFS_MAX_KEY_BYTES) { |
259 | ecryptfs_printk(KERN_ERR, "key_size [%d] larger than " |
260 | "the maximum key size [%d]\n" , |
261 | session_key->decrypted_key_size, |
262 | ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES); |
263 | rc = -EIO; |
264 | goto out; |
265 | } |
266 | memcpy(session_key->decrypted_key, &data[i], |
267 | session_key->decrypted_key_size); |
268 | i += session_key->decrypted_key_size; |
269 | expected_checksum += (unsigned char)(data[i++]) << 8; |
270 | expected_checksum += (unsigned char)(data[i++]); |
271 | for (i = 0; i < session_key->decrypted_key_size; i++) |
272 | checksum += session_key->decrypted_key[i]; |
273 | if (expected_checksum != checksum) { |
274 | ecryptfs_printk(KERN_ERR, "Invalid checksum for file " |
275 | "encryption key; expected [%x]; calculated " |
276 | "[%x]\n" , expected_checksum, checksum); |
277 | rc = -EIO; |
278 | } |
279 | out: |
280 | return rc; |
281 | } |
282 | |
283 | |
284 | static int |
285 | write_tag_66_packet(char *signature, u8 cipher_code, |
286 | struct ecryptfs_crypt_stat *crypt_stat, char **packet, |
287 | size_t *packet_len) |
288 | { |
289 | size_t i = 0; |
290 | size_t j; |
291 | size_t data_len; |
292 | size_t checksum = 0; |
293 | size_t packet_size_len; |
294 | char *message; |
295 | int rc; |
296 | |
297 | /* |
298 | * ***** TAG 66 Packet Format ***** |
299 | * | Content Type | 1 byte | |
300 | * | Key Identifier Size | 1 or 2 bytes | |
301 | * | Key Identifier | arbitrary | |
302 | * | File Encryption Key Size | 1 or 2 bytes | |
303 | * | File Encryption Key | arbitrary | |
304 | */ |
305 | data_len = (5 + ECRYPTFS_SIG_SIZE_HEX + crypt_stat->key_size); |
306 | *packet = kmalloc(size: data_len, GFP_KERNEL); |
307 | message = *packet; |
308 | if (!message) { |
309 | ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n" ); |
310 | rc = -ENOMEM; |
311 | goto out; |
312 | } |
313 | message[i++] = ECRYPTFS_TAG_66_PACKET_TYPE; |
314 | rc = ecryptfs_write_packet_length(dest: &message[i], ECRYPTFS_SIG_SIZE_HEX, |
315 | packet_size_length: &packet_size_len); |
316 | if (rc) { |
317 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet " |
318 | "header; cannot generate packet length\n" ); |
319 | goto out; |
320 | } |
321 | i += packet_size_len; |
322 | memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX); |
323 | i += ECRYPTFS_SIG_SIZE_HEX; |
324 | /* The encrypted key includes 1 byte cipher code and 2 byte checksum */ |
325 | rc = ecryptfs_write_packet_length(dest: &message[i], size: crypt_stat->key_size + 3, |
326 | packet_size_length: &packet_size_len); |
327 | if (rc) { |
328 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet " |
329 | "header; cannot generate packet length\n" ); |
330 | goto out; |
331 | } |
332 | i += packet_size_len; |
333 | message[i++] = cipher_code; |
334 | memcpy(&message[i], crypt_stat->key, crypt_stat->key_size); |
335 | i += crypt_stat->key_size; |
336 | for (j = 0; j < crypt_stat->key_size; j++) |
337 | checksum += crypt_stat->key[j]; |
338 | message[i++] = (checksum / 256) % 256; |
339 | message[i++] = (checksum % 256); |
340 | *packet_len = i; |
341 | out: |
342 | return rc; |
343 | } |
344 | |
345 | static int |
346 | parse_tag_67_packet(struct ecryptfs_key_record *key_rec, |
347 | struct ecryptfs_message *msg) |
348 | { |
349 | size_t i = 0; |
350 | char *data; |
351 | size_t data_len; |
352 | size_t message_len; |
353 | int rc; |
354 | |
355 | /* |
356 | * ***** TAG 65 Packet Format ***** |
357 | * | Content Type | 1 byte | |
358 | * | Status Indicator | 1 byte | |
359 | * | Encrypted File Encryption Key Size | 1 or 2 bytes | |
360 | * | Encrypted File Encryption Key | arbitrary | |
361 | */ |
362 | message_len = msg->data_len; |
363 | data = msg->data; |
364 | /* verify that everything through the encrypted FEK size is present */ |
365 | if (message_len < 4) { |
366 | rc = -EIO; |
367 | printk(KERN_ERR "%s: message_len is [%zd]; minimum acceptable " |
368 | "message length is [%d]\n" , __func__, message_len, 4); |
369 | goto out; |
370 | } |
371 | if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) { |
372 | rc = -EIO; |
373 | printk(KERN_ERR "%s: Type should be ECRYPTFS_TAG_67\n" , |
374 | __func__); |
375 | goto out; |
376 | } |
377 | if (data[i++]) { |
378 | rc = -EIO; |
379 | printk(KERN_ERR "%s: Status indicator has non zero " |
380 | "value [%d]\n" , __func__, data[i-1]); |
381 | |
382 | goto out; |
383 | } |
384 | rc = ecryptfs_parse_packet_length(data: &data[i], size: &key_rec->enc_key_size, |
385 | length_size: &data_len); |
386 | if (rc) { |
387 | ecryptfs_printk(KERN_WARNING, "Error parsing packet length; " |
388 | "rc = [%d]\n" , rc); |
389 | goto out; |
390 | } |
391 | i += data_len; |
392 | if (message_len < (i + key_rec->enc_key_size)) { |
393 | rc = -EIO; |
394 | printk(KERN_ERR "%s: message_len [%zd]; max len is [%zd]\n" , |
395 | __func__, message_len, (i + key_rec->enc_key_size)); |
396 | goto out; |
397 | } |
398 | if (key_rec->enc_key_size > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { |
399 | rc = -EIO; |
400 | printk(KERN_ERR "%s: Encrypted key_size [%zd] larger than " |
401 | "the maximum key size [%d]\n" , __func__, |
402 | key_rec->enc_key_size, |
403 | ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES); |
404 | goto out; |
405 | } |
406 | memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size); |
407 | out: |
408 | return rc; |
409 | } |
410 | |
411 | /** |
412 | * ecryptfs_verify_version |
413 | * @version: The version number to confirm |
414 | * |
415 | * Returns zero on good version; non-zero otherwise |
416 | */ |
417 | static int ecryptfs_verify_version(u16 version) |
418 | { |
419 | int rc = 0; |
420 | unsigned char major; |
421 | unsigned char minor; |
422 | |
423 | major = ((version >> 8) & 0xFF); |
424 | minor = (version & 0xFF); |
425 | if (major != ECRYPTFS_VERSION_MAJOR) { |
426 | ecryptfs_printk(KERN_ERR, "Major version number mismatch. " |
427 | "Expected [%d]; got [%d]\n" , |
428 | ECRYPTFS_VERSION_MAJOR, major); |
429 | rc = -EINVAL; |
430 | goto out; |
431 | } |
432 | if (minor != ECRYPTFS_VERSION_MINOR) { |
433 | ecryptfs_printk(KERN_ERR, "Minor version number mismatch. " |
434 | "Expected [%d]; got [%d]\n" , |
435 | ECRYPTFS_VERSION_MINOR, minor); |
436 | rc = -EINVAL; |
437 | goto out; |
438 | } |
439 | out: |
440 | return rc; |
441 | } |
442 | |
443 | /** |
444 | * ecryptfs_verify_auth_tok_from_key |
445 | * @auth_tok_key: key containing the authentication token |
446 | * @auth_tok: authentication token |
447 | * |
448 | * Returns zero on valid auth tok; -EINVAL if the payload is invalid; or |
449 | * -EKEYREVOKED if the key was revoked before we acquired its semaphore. |
450 | */ |
451 | static int |
452 | ecryptfs_verify_auth_tok_from_key(struct key *auth_tok_key, |
453 | struct ecryptfs_auth_tok **auth_tok) |
454 | { |
455 | int rc = 0; |
456 | |
457 | (*auth_tok) = ecryptfs_get_key_payload_data(key: auth_tok_key); |
458 | if (IS_ERR(ptr: *auth_tok)) { |
459 | rc = PTR_ERR(ptr: *auth_tok); |
460 | *auth_tok = NULL; |
461 | goto out; |
462 | } |
463 | |
464 | if (ecryptfs_verify_version(version: (*auth_tok)->version)) { |
465 | printk(KERN_ERR "Data structure version mismatch. Userspace " |
466 | "tools must match eCryptfs kernel module with major " |
467 | "version [%d] and minor version [%d]\n" , |
468 | ECRYPTFS_VERSION_MAJOR, ECRYPTFS_VERSION_MINOR); |
469 | rc = -EINVAL; |
470 | goto out; |
471 | } |
472 | if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD |
473 | && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) { |
474 | printk(KERN_ERR "Invalid auth_tok structure " |
475 | "returned from key query\n" ); |
476 | rc = -EINVAL; |
477 | goto out; |
478 | } |
479 | out: |
480 | return rc; |
481 | } |
482 | |
483 | static int |
484 | ecryptfs_find_global_auth_tok_for_sig( |
485 | struct key **auth_tok_key, |
486 | struct ecryptfs_auth_tok **auth_tok, |
487 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig) |
488 | { |
489 | struct ecryptfs_global_auth_tok *walker; |
490 | int rc = 0; |
491 | |
492 | (*auth_tok_key) = NULL; |
493 | (*auth_tok) = NULL; |
494 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); |
495 | list_for_each_entry(walker, |
496 | &mount_crypt_stat->global_auth_tok_list, |
497 | mount_crypt_stat_list) { |
498 | if (memcmp(p: walker->sig, q: sig, ECRYPTFS_SIG_SIZE_HEX)) |
499 | continue; |
500 | |
501 | if (walker->flags & ECRYPTFS_AUTH_TOK_INVALID) { |
502 | rc = -EINVAL; |
503 | goto out; |
504 | } |
505 | |
506 | rc = key_validate(key: walker->global_auth_tok_key); |
507 | if (rc) { |
508 | if (rc == -EKEYEXPIRED) |
509 | goto out; |
510 | goto out_invalid_auth_tok; |
511 | } |
512 | |
513 | down_write(sem: &(walker->global_auth_tok_key->sem)); |
514 | rc = ecryptfs_verify_auth_tok_from_key( |
515 | auth_tok_key: walker->global_auth_tok_key, auth_tok); |
516 | if (rc) |
517 | goto out_invalid_auth_tok_unlock; |
518 | |
519 | (*auth_tok_key) = walker->global_auth_tok_key; |
520 | key_get(key: *auth_tok_key); |
521 | goto out; |
522 | } |
523 | rc = -ENOENT; |
524 | goto out; |
525 | out_invalid_auth_tok_unlock: |
526 | up_write(sem: &(walker->global_auth_tok_key->sem)); |
527 | out_invalid_auth_tok: |
528 | printk(KERN_WARNING "Invalidating auth tok with sig = [%s]\n" , sig); |
529 | walker->flags |= ECRYPTFS_AUTH_TOK_INVALID; |
530 | key_put(key: walker->global_auth_tok_key); |
531 | walker->global_auth_tok_key = NULL; |
532 | out: |
533 | mutex_unlock(lock: &mount_crypt_stat->global_auth_tok_list_mutex); |
534 | return rc; |
535 | } |
536 | |
537 | /** |
538 | * ecryptfs_find_auth_tok_for_sig |
539 | * @auth_tok_key: key containing the authentication token |
540 | * @auth_tok: Set to the matching auth_tok; NULL if not found |
541 | * @mount_crypt_stat: inode crypt_stat crypto context |
542 | * @sig: Sig of auth_tok to find |
543 | * |
544 | * For now, this function simply looks at the registered auth_tok's |
545 | * linked off the mount_crypt_stat, so all the auth_toks that can be |
546 | * used must be registered at mount time. This function could |
547 | * potentially try a lot harder to find auth_tok's (e.g., by calling |
548 | * out to ecryptfsd to dynamically retrieve an auth_tok object) so |
549 | * that static registration of auth_tok's will no longer be necessary. |
550 | * |
551 | * Returns zero on no error; non-zero on error |
552 | */ |
553 | static int |
554 | ecryptfs_find_auth_tok_for_sig( |
555 | struct key **auth_tok_key, |
556 | struct ecryptfs_auth_tok **auth_tok, |
557 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, |
558 | char *sig) |
559 | { |
560 | int rc = 0; |
561 | |
562 | rc = ecryptfs_find_global_auth_tok_for_sig(auth_tok_key, auth_tok, |
563 | mount_crypt_stat, sig); |
564 | if (rc == -ENOENT) { |
565 | /* if the flag ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY is set in the |
566 | * mount_crypt_stat structure, we prevent to use auth toks that |
567 | * are not inserted through the ecryptfs_add_global_auth_tok |
568 | * function. |
569 | */ |
570 | if (mount_crypt_stat->flags |
571 | & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY) |
572 | return -EINVAL; |
573 | |
574 | rc = ecryptfs_keyring_auth_tok_for_sig(auth_tok_key, auth_tok, |
575 | sig); |
576 | } |
577 | return rc; |
578 | } |
579 | |
580 | /* |
581 | * write_tag_70_packet can gobble a lot of stack space. We stuff most |
582 | * of the function's parameters in a kmalloc'd struct to help reduce |
583 | * eCryptfs' overall stack usage. |
584 | */ |
585 | struct ecryptfs_write_tag_70_packet_silly_stack { |
586 | u8 cipher_code; |
587 | size_t max_packet_size; |
588 | size_t packet_size_len; |
589 | size_t block_aligned_filename_size; |
590 | size_t block_size; |
591 | size_t i; |
592 | size_t j; |
593 | size_t num_rand_bytes; |
594 | struct mutex *tfm_mutex; |
595 | char *block_aligned_filename; |
596 | struct ecryptfs_auth_tok *auth_tok; |
597 | struct scatterlist src_sg[2]; |
598 | struct scatterlist dst_sg[2]; |
599 | struct crypto_skcipher *skcipher_tfm; |
600 | struct skcipher_request *skcipher_req; |
601 | char iv[ECRYPTFS_MAX_IV_BYTES]; |
602 | char hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; |
603 | char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; |
604 | struct crypto_shash *hash_tfm; |
605 | struct shash_desc *hash_desc; |
606 | }; |
607 | |
608 | /* |
609 | * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK |
610 | * @filename: NULL-terminated filename string |
611 | * |
612 | * This is the simplest mechanism for achieving filename encryption in |
613 | * eCryptfs. It encrypts the given filename with the mount-wide |
614 | * filename encryption key (FNEK) and stores it in a packet to @dest, |
615 | * which the callee will encode and write directly into the dentry |
616 | * name. |
617 | */ |
618 | int |
619 | ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, |
620 | size_t *packet_size, |
621 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, |
622 | char *filename, size_t filename_size) |
623 | { |
624 | struct ecryptfs_write_tag_70_packet_silly_stack *s; |
625 | struct key *auth_tok_key = NULL; |
626 | int rc = 0; |
627 | |
628 | s = kzalloc(size: sizeof(*s), GFP_KERNEL); |
629 | if (!s) |
630 | return -ENOMEM; |
631 | |
632 | (*packet_size) = 0; |
633 | rc = ecryptfs_find_auth_tok_for_sig( |
634 | auth_tok_key: &auth_tok_key, |
635 | auth_tok: &s->auth_tok, mount_crypt_stat, |
636 | sig: mount_crypt_stat->global_default_fnek_sig); |
637 | if (rc) { |
638 | printk(KERN_ERR "%s: Error attempting to find auth tok for " |
639 | "fnek sig [%s]; rc = [%d]\n" , __func__, |
640 | mount_crypt_stat->global_default_fnek_sig, rc); |
641 | goto out; |
642 | } |
643 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name( |
644 | tfm: &s->skcipher_tfm, |
645 | tfm_mutex: &s->tfm_mutex, cipher_name: mount_crypt_stat->global_default_fn_cipher_name); |
646 | if (unlikely(rc)) { |
647 | printk(KERN_ERR "Internal error whilst attempting to get " |
648 | "tfm and mutex for cipher name [%s]; rc = [%d]\n" , |
649 | mount_crypt_stat->global_default_fn_cipher_name, rc); |
650 | goto out; |
651 | } |
652 | mutex_lock(s->tfm_mutex); |
653 | s->block_size = crypto_skcipher_blocksize(tfm: s->skcipher_tfm); |
654 | /* Plus one for the \0 separator between the random prefix |
655 | * and the plaintext filename */ |
656 | s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1); |
657 | s->block_aligned_filename_size = (s->num_rand_bytes + filename_size); |
658 | if ((s->block_aligned_filename_size % s->block_size) != 0) { |
659 | s->num_rand_bytes += (s->block_size |
660 | - (s->block_aligned_filename_size |
661 | % s->block_size)); |
662 | s->block_aligned_filename_size = (s->num_rand_bytes |
663 | + filename_size); |
664 | } |
665 | /* Octet 0: Tag 70 identifier |
666 | * Octets 1-N1: Tag 70 packet size (includes cipher identifier |
667 | * and block-aligned encrypted filename size) |
668 | * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) |
669 | * Octet N2-N3: Cipher identifier (1 octet) |
670 | * Octets N3-N4: Block-aligned encrypted filename |
671 | * - Consists of a minimum number of random characters, a \0 |
672 | * separator, and then the filename */ |
673 | s->max_packet_size = (ECRYPTFS_TAG_70_MAX_METADATA_SIZE |
674 | + s->block_aligned_filename_size); |
675 | if (!dest) { |
676 | (*packet_size) = s->max_packet_size; |
677 | goto out_unlock; |
678 | } |
679 | if (s->max_packet_size > (*remaining_bytes)) { |
680 | printk(KERN_WARNING "%s: Require [%zd] bytes to write; only " |
681 | "[%zd] available\n" , __func__, s->max_packet_size, |
682 | (*remaining_bytes)); |
683 | rc = -EINVAL; |
684 | goto out_unlock; |
685 | } |
686 | |
687 | s->skcipher_req = skcipher_request_alloc(tfm: s->skcipher_tfm, GFP_KERNEL); |
688 | if (!s->skcipher_req) { |
689 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " |
690 | "skcipher_request_alloc for %s\n" , __func__, |
691 | crypto_skcipher_driver_name(s->skcipher_tfm)); |
692 | rc = -ENOMEM; |
693 | goto out_unlock; |
694 | } |
695 | |
696 | skcipher_request_set_callback(req: s->skcipher_req, |
697 | CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL); |
698 | |
699 | s->block_aligned_filename = kzalloc(size: s->block_aligned_filename_size, |
700 | GFP_KERNEL); |
701 | if (!s->block_aligned_filename) { |
702 | rc = -ENOMEM; |
703 | goto out_unlock; |
704 | } |
705 | dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE; |
706 | rc = ecryptfs_write_packet_length(dest: &dest[s->i], |
707 | size: (ECRYPTFS_SIG_SIZE |
708 | + 1 /* Cipher code */ |
709 | + s->block_aligned_filename_size), |
710 | packet_size_length: &s->packet_size_len); |
711 | if (rc) { |
712 | printk(KERN_ERR "%s: Error generating tag 70 packet " |
713 | "header; cannot generate packet length; rc = [%d]\n" , |
714 | __func__, rc); |
715 | goto out_free_unlock; |
716 | } |
717 | s->i += s->packet_size_len; |
718 | ecryptfs_from_hex(dst: &dest[s->i], |
719 | src: mount_crypt_stat->global_default_fnek_sig, |
720 | ECRYPTFS_SIG_SIZE); |
721 | s->i += ECRYPTFS_SIG_SIZE; |
722 | s->cipher_code = ecryptfs_code_for_cipher_string( |
723 | cipher_name: mount_crypt_stat->global_default_fn_cipher_name, |
724 | key_bytes: mount_crypt_stat->global_default_fn_cipher_key_bytes); |
725 | if (s->cipher_code == 0) { |
726 | printk(KERN_WARNING "%s: Unable to generate code for " |
727 | "cipher [%s] with key bytes [%zd]\n" , __func__, |
728 | mount_crypt_stat->global_default_fn_cipher_name, |
729 | mount_crypt_stat->global_default_fn_cipher_key_bytes); |
730 | rc = -EINVAL; |
731 | goto out_free_unlock; |
732 | } |
733 | dest[s->i++] = s->cipher_code; |
734 | /* TODO: Support other key modules than passphrase for |
735 | * filename encryption */ |
736 | if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) { |
737 | rc = -EOPNOTSUPP; |
738 | printk(KERN_INFO "%s: Filename encryption only supports " |
739 | "password tokens\n" , __func__); |
740 | goto out_free_unlock; |
741 | } |
742 | s->hash_tfm = crypto_alloc_shash(ECRYPTFS_TAG_70_DIGEST, type: 0, mask: 0); |
743 | if (IS_ERR(ptr: s->hash_tfm)) { |
744 | rc = PTR_ERR(ptr: s->hash_tfm); |
745 | printk(KERN_ERR "%s: Error attempting to " |
746 | "allocate hash crypto context; rc = [%d]\n" , |
747 | __func__, rc); |
748 | goto out_free_unlock; |
749 | } |
750 | |
751 | s->hash_desc = kmalloc(size: sizeof(*s->hash_desc) + |
752 | crypto_shash_descsize(tfm: s->hash_tfm), GFP_KERNEL); |
753 | if (!s->hash_desc) { |
754 | rc = -ENOMEM; |
755 | goto out_release_free_unlock; |
756 | } |
757 | |
758 | s->hash_desc->tfm = s->hash_tfm; |
759 | |
760 | rc = crypto_shash_digest(desc: s->hash_desc, |
761 | data: (u8 *)s->auth_tok->token.password.session_key_encryption_key, |
762 | len: s->auth_tok->token.password.session_key_encryption_key_bytes, |
763 | out: s->hash); |
764 | if (rc) { |
765 | printk(KERN_ERR |
766 | "%s: Error computing crypto hash; rc = [%d]\n" , |
767 | __func__, rc); |
768 | goto out_release_free_unlock; |
769 | } |
770 | for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) { |
771 | s->block_aligned_filename[s->j] = |
772 | s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)]; |
773 | if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE) |
774 | == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) { |
775 | rc = crypto_shash_digest(desc: s->hash_desc, data: (u8 *)s->hash, |
776 | ECRYPTFS_TAG_70_DIGEST_SIZE, |
777 | out: s->tmp_hash); |
778 | if (rc) { |
779 | printk(KERN_ERR |
780 | "%s: Error computing crypto hash; " |
781 | "rc = [%d]\n" , __func__, rc); |
782 | goto out_release_free_unlock; |
783 | } |
784 | memcpy(s->hash, s->tmp_hash, |
785 | ECRYPTFS_TAG_70_DIGEST_SIZE); |
786 | } |
787 | if (s->block_aligned_filename[s->j] == '\0') |
788 | s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL; |
789 | } |
790 | memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename, |
791 | filename_size); |
792 | rc = virt_to_scatterlist(addr: s->block_aligned_filename, |
793 | size: s->block_aligned_filename_size, sg: s->src_sg, sg_size: 2); |
794 | if (rc < 1) { |
795 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
796 | "convert filename memory to scatterlist; rc = [%d]. " |
797 | "block_aligned_filename_size = [%zd]\n" , __func__, rc, |
798 | s->block_aligned_filename_size); |
799 | goto out_release_free_unlock; |
800 | } |
801 | rc = virt_to_scatterlist(addr: &dest[s->i], size: s->block_aligned_filename_size, |
802 | sg: s->dst_sg, sg_size: 2); |
803 | if (rc < 1) { |
804 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
805 | "convert encrypted filename memory to scatterlist; " |
806 | "rc = [%d]. block_aligned_filename_size = [%zd]\n" , |
807 | __func__, rc, s->block_aligned_filename_size); |
808 | goto out_release_free_unlock; |
809 | } |
810 | /* The characters in the first block effectively do the job |
811 | * of the IV here, so we just use 0's for the IV. Note the |
812 | * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES |
813 | * >= ECRYPTFS_MAX_IV_BYTES. */ |
814 | rc = crypto_skcipher_setkey( |
815 | tfm: s->skcipher_tfm, |
816 | key: s->auth_tok->token.password.session_key_encryption_key, |
817 | keylen: mount_crypt_stat->global_default_fn_cipher_key_bytes); |
818 | if (rc < 0) { |
819 | printk(KERN_ERR "%s: Error setting key for crypto context; " |
820 | "rc = [%d]. s->auth_tok->token.password.session_key_" |
821 | "encryption_key = [0x%p]; mount_crypt_stat->" |
822 | "global_default_fn_cipher_key_bytes = [%zd]\n" , __func__, |
823 | rc, |
824 | s->auth_tok->token.password.session_key_encryption_key, |
825 | mount_crypt_stat->global_default_fn_cipher_key_bytes); |
826 | goto out_release_free_unlock; |
827 | } |
828 | skcipher_request_set_crypt(req: s->skcipher_req, src: s->src_sg, dst: s->dst_sg, |
829 | cryptlen: s->block_aligned_filename_size, iv: s->iv); |
830 | rc = crypto_skcipher_encrypt(req: s->skcipher_req); |
831 | if (rc) { |
832 | printk(KERN_ERR "%s: Error attempting to encrypt filename; " |
833 | "rc = [%d]\n" , __func__, rc); |
834 | goto out_release_free_unlock; |
835 | } |
836 | s->i += s->block_aligned_filename_size; |
837 | (*packet_size) = s->i; |
838 | (*remaining_bytes) -= (*packet_size); |
839 | out_release_free_unlock: |
840 | crypto_free_shash(tfm: s->hash_tfm); |
841 | out_free_unlock: |
842 | kfree_sensitive(objp: s->block_aligned_filename); |
843 | out_unlock: |
844 | mutex_unlock(lock: s->tfm_mutex); |
845 | out: |
846 | if (auth_tok_key) { |
847 | up_write(sem: &(auth_tok_key->sem)); |
848 | key_put(key: auth_tok_key); |
849 | } |
850 | skcipher_request_free(req: s->skcipher_req); |
851 | kfree_sensitive(objp: s->hash_desc); |
852 | kfree(objp: s); |
853 | return rc; |
854 | } |
855 | |
856 | struct ecryptfs_parse_tag_70_packet_silly_stack { |
857 | u8 cipher_code; |
858 | size_t max_packet_size; |
859 | size_t packet_size_len; |
860 | size_t parsed_tag_70_packet_size; |
861 | size_t block_aligned_filename_size; |
862 | size_t block_size; |
863 | size_t i; |
864 | struct mutex *tfm_mutex; |
865 | char *decrypted_filename; |
866 | struct ecryptfs_auth_tok *auth_tok; |
867 | struct scatterlist src_sg[2]; |
868 | struct scatterlist dst_sg[2]; |
869 | struct crypto_skcipher *skcipher_tfm; |
870 | struct skcipher_request *skcipher_req; |
871 | char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1]; |
872 | char iv[ECRYPTFS_MAX_IV_BYTES]; |
873 | char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1]; |
874 | }; |
875 | |
876 | /** |
877 | * ecryptfs_parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet |
878 | * @filename: This function kmalloc's the memory for the filename |
879 | * @filename_size: This function sets this to the amount of memory |
880 | * kmalloc'd for the filename |
881 | * @packet_size: This function sets this to the the number of octets |
882 | * in the packet parsed |
883 | * @mount_crypt_stat: The mount-wide cryptographic context |
884 | * @data: The memory location containing the start of the tag 70 |
885 | * packet |
886 | * @max_packet_size: The maximum legal size of the packet to be parsed |
887 | * from @data |
888 | * |
889 | * Returns zero on success; non-zero otherwise |
890 | */ |
891 | int |
892 | ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, |
893 | size_t *packet_size, |
894 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, |
895 | char *data, size_t max_packet_size) |
896 | { |
897 | struct ecryptfs_parse_tag_70_packet_silly_stack *s; |
898 | struct key *auth_tok_key = NULL; |
899 | int rc = 0; |
900 | |
901 | (*packet_size) = 0; |
902 | (*filename_size) = 0; |
903 | (*filename) = NULL; |
904 | s = kzalloc(size: sizeof(*s), GFP_KERNEL); |
905 | if (!s) |
906 | return -ENOMEM; |
907 | |
908 | if (max_packet_size < ECRYPTFS_TAG_70_MIN_METADATA_SIZE) { |
909 | printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be " |
910 | "at least [%d]\n" , __func__, max_packet_size, |
911 | ECRYPTFS_TAG_70_MIN_METADATA_SIZE); |
912 | rc = -EINVAL; |
913 | goto out; |
914 | } |
915 | /* Octet 0: Tag 70 identifier |
916 | * Octets 1-N1: Tag 70 packet size (includes cipher identifier |
917 | * and block-aligned encrypted filename size) |
918 | * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) |
919 | * Octet N2-N3: Cipher identifier (1 octet) |
920 | * Octets N3-N4: Block-aligned encrypted filename |
921 | * - Consists of a minimum number of random numbers, a \0 |
922 | * separator, and then the filename */ |
923 | if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) { |
924 | printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be " |
925 | "tag [0x%.2x]\n" , __func__, |
926 | data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE); |
927 | rc = -EINVAL; |
928 | goto out; |
929 | } |
930 | rc = ecryptfs_parse_packet_length(data: &data[(*packet_size)], |
931 | size: &s->parsed_tag_70_packet_size, |
932 | length_size: &s->packet_size_len); |
933 | if (rc) { |
934 | printk(KERN_WARNING "%s: Error parsing packet length; " |
935 | "rc = [%d]\n" , __func__, rc); |
936 | goto out; |
937 | } |
938 | s->block_aligned_filename_size = (s->parsed_tag_70_packet_size |
939 | - ECRYPTFS_SIG_SIZE - 1); |
940 | if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size) |
941 | > max_packet_size) { |
942 | printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet " |
943 | "size is [%zd]\n" , __func__, max_packet_size, |
944 | (1 + s->packet_size_len + 1 |
945 | + s->block_aligned_filename_size)); |
946 | rc = -EINVAL; |
947 | goto out; |
948 | } |
949 | (*packet_size) += s->packet_size_len; |
950 | ecryptfs_to_hex(dst: s->fnek_sig_hex, src: &data[(*packet_size)], |
951 | ECRYPTFS_SIG_SIZE); |
952 | s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
953 | (*packet_size) += ECRYPTFS_SIG_SIZE; |
954 | s->cipher_code = data[(*packet_size)++]; |
955 | rc = ecryptfs_cipher_code_to_string(str: s->cipher_string, cipher_code: s->cipher_code); |
956 | if (rc) { |
957 | printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n" , |
958 | __func__, s->cipher_code); |
959 | goto out; |
960 | } |
961 | rc = ecryptfs_find_auth_tok_for_sig(auth_tok_key: &auth_tok_key, |
962 | auth_tok: &s->auth_tok, mount_crypt_stat, |
963 | sig: s->fnek_sig_hex); |
964 | if (rc) { |
965 | printk(KERN_ERR "%s: Error attempting to find auth tok for " |
966 | "fnek sig [%s]; rc = [%d]\n" , __func__, s->fnek_sig_hex, |
967 | rc); |
968 | goto out; |
969 | } |
970 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(tfm: &s->skcipher_tfm, |
971 | tfm_mutex: &s->tfm_mutex, |
972 | cipher_name: s->cipher_string); |
973 | if (unlikely(rc)) { |
974 | printk(KERN_ERR "Internal error whilst attempting to get " |
975 | "tfm and mutex for cipher name [%s]; rc = [%d]\n" , |
976 | s->cipher_string, rc); |
977 | goto out; |
978 | } |
979 | mutex_lock(s->tfm_mutex); |
980 | rc = virt_to_scatterlist(addr: &data[(*packet_size)], |
981 | size: s->block_aligned_filename_size, sg: s->src_sg, sg_size: 2); |
982 | if (rc < 1) { |
983 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
984 | "convert encrypted filename memory to scatterlist; " |
985 | "rc = [%d]. block_aligned_filename_size = [%zd]\n" , |
986 | __func__, rc, s->block_aligned_filename_size); |
987 | goto out_unlock; |
988 | } |
989 | (*packet_size) += s->block_aligned_filename_size; |
990 | s->decrypted_filename = kmalloc(size: s->block_aligned_filename_size, |
991 | GFP_KERNEL); |
992 | if (!s->decrypted_filename) { |
993 | rc = -ENOMEM; |
994 | goto out_unlock; |
995 | } |
996 | rc = virt_to_scatterlist(addr: s->decrypted_filename, |
997 | size: s->block_aligned_filename_size, sg: s->dst_sg, sg_size: 2); |
998 | if (rc < 1) { |
999 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
1000 | "convert decrypted filename memory to scatterlist; " |
1001 | "rc = [%d]. block_aligned_filename_size = [%zd]\n" , |
1002 | __func__, rc, s->block_aligned_filename_size); |
1003 | goto out_free_unlock; |
1004 | } |
1005 | |
1006 | s->skcipher_req = skcipher_request_alloc(tfm: s->skcipher_tfm, GFP_KERNEL); |
1007 | if (!s->skcipher_req) { |
1008 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " |
1009 | "skcipher_request_alloc for %s\n" , __func__, |
1010 | crypto_skcipher_driver_name(s->skcipher_tfm)); |
1011 | rc = -ENOMEM; |
1012 | goto out_free_unlock; |
1013 | } |
1014 | |
1015 | skcipher_request_set_callback(req: s->skcipher_req, |
1016 | CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL); |
1017 | |
1018 | /* The characters in the first block effectively do the job of |
1019 | * the IV here, so we just use 0's for the IV. Note the |
1020 | * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES |
1021 | * >= ECRYPTFS_MAX_IV_BYTES. */ |
1022 | /* TODO: Support other key modules than passphrase for |
1023 | * filename encryption */ |
1024 | if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) { |
1025 | rc = -EOPNOTSUPP; |
1026 | printk(KERN_INFO "%s: Filename encryption only supports " |
1027 | "password tokens\n" , __func__); |
1028 | goto out_free_unlock; |
1029 | } |
1030 | rc = crypto_skcipher_setkey( |
1031 | tfm: s->skcipher_tfm, |
1032 | key: s->auth_tok->token.password.session_key_encryption_key, |
1033 | keylen: mount_crypt_stat->global_default_fn_cipher_key_bytes); |
1034 | if (rc < 0) { |
1035 | printk(KERN_ERR "%s: Error setting key for crypto context; " |
1036 | "rc = [%d]. s->auth_tok->token.password.session_key_" |
1037 | "encryption_key = [0x%p]; mount_crypt_stat->" |
1038 | "global_default_fn_cipher_key_bytes = [%zd]\n" , __func__, |
1039 | rc, |
1040 | s->auth_tok->token.password.session_key_encryption_key, |
1041 | mount_crypt_stat->global_default_fn_cipher_key_bytes); |
1042 | goto out_free_unlock; |
1043 | } |
1044 | skcipher_request_set_crypt(req: s->skcipher_req, src: s->src_sg, dst: s->dst_sg, |
1045 | cryptlen: s->block_aligned_filename_size, iv: s->iv); |
1046 | rc = crypto_skcipher_decrypt(req: s->skcipher_req); |
1047 | if (rc) { |
1048 | printk(KERN_ERR "%s: Error attempting to decrypt filename; " |
1049 | "rc = [%d]\n" , __func__, rc); |
1050 | goto out_free_unlock; |
1051 | } |
1052 | |
1053 | while (s->i < s->block_aligned_filename_size && |
1054 | s->decrypted_filename[s->i] != '\0') |
1055 | s->i++; |
1056 | if (s->i == s->block_aligned_filename_size) { |
1057 | printk(KERN_WARNING "%s: Invalid tag 70 packet; could not " |
1058 | "find valid separator between random characters and " |
1059 | "the filename\n" , __func__); |
1060 | rc = -EINVAL; |
1061 | goto out_free_unlock; |
1062 | } |
1063 | s->i++; |
1064 | (*filename_size) = (s->block_aligned_filename_size - s->i); |
1065 | if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) { |
1066 | printk(KERN_WARNING "%s: Filename size is [%zd], which is " |
1067 | "invalid\n" , __func__, (*filename_size)); |
1068 | rc = -EINVAL; |
1069 | goto out_free_unlock; |
1070 | } |
1071 | (*filename) = kmalloc(size: ((*filename_size) + 1), GFP_KERNEL); |
1072 | if (!(*filename)) { |
1073 | rc = -ENOMEM; |
1074 | goto out_free_unlock; |
1075 | } |
1076 | memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size)); |
1077 | (*filename)[(*filename_size)] = '\0'; |
1078 | out_free_unlock: |
1079 | kfree(objp: s->decrypted_filename); |
1080 | out_unlock: |
1081 | mutex_unlock(lock: s->tfm_mutex); |
1082 | out: |
1083 | if (rc) { |
1084 | (*packet_size) = 0; |
1085 | (*filename_size) = 0; |
1086 | (*filename) = NULL; |
1087 | } |
1088 | if (auth_tok_key) { |
1089 | up_write(sem: &(auth_tok_key->sem)); |
1090 | key_put(key: auth_tok_key); |
1091 | } |
1092 | skcipher_request_free(req: s->skcipher_req); |
1093 | kfree(objp: s); |
1094 | return rc; |
1095 | } |
1096 | |
1097 | static int |
1098 | ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok) |
1099 | { |
1100 | int rc = 0; |
1101 | |
1102 | (*sig) = NULL; |
1103 | switch (auth_tok->token_type) { |
1104 | case ECRYPTFS_PASSWORD: |
1105 | (*sig) = auth_tok->token.password.signature; |
1106 | break; |
1107 | case ECRYPTFS_PRIVATE_KEY: |
1108 | (*sig) = auth_tok->token.private_key.signature; |
1109 | break; |
1110 | default: |
1111 | printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n" , |
1112 | auth_tok->token_type); |
1113 | rc = -EINVAL; |
1114 | } |
1115 | return rc; |
1116 | } |
1117 | |
1118 | /** |
1119 | * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok. |
1120 | * @auth_tok: The key authentication token used to decrypt the session key |
1121 | * @crypt_stat: The cryptographic context |
1122 | * |
1123 | * Returns zero on success; non-zero error otherwise. |
1124 | */ |
1125 | static int |
1126 | decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, |
1127 | struct ecryptfs_crypt_stat *crypt_stat) |
1128 | { |
1129 | u8 cipher_code = 0; |
1130 | struct ecryptfs_msg_ctx *msg_ctx; |
1131 | struct ecryptfs_message *msg = NULL; |
1132 | char *auth_tok_sig; |
1133 | char *payload = NULL; |
1134 | size_t payload_len = 0; |
1135 | int rc; |
1136 | |
1137 | rc = ecryptfs_get_auth_tok_sig(sig: &auth_tok_sig, auth_tok); |
1138 | if (rc) { |
1139 | printk(KERN_ERR "Unrecognized auth tok type: [%d]\n" , |
1140 | auth_tok->token_type); |
1141 | goto out; |
1142 | } |
1143 | rc = write_tag_64_packet(signature: auth_tok_sig, session_key: &(auth_tok->session_key), |
1144 | packet: &payload, packet_len: &payload_len); |
1145 | if (rc) { |
1146 | ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n" ); |
1147 | goto out; |
1148 | } |
1149 | rc = ecryptfs_send_message(data: payload, data_len: payload_len, msg_ctx: &msg_ctx); |
1150 | if (rc) { |
1151 | ecryptfs_printk(KERN_ERR, "Error sending message to " |
1152 | "ecryptfsd: %d\n" , rc); |
1153 | goto out; |
1154 | } |
1155 | rc = ecryptfs_wait_for_response(msg_ctx, emsg: &msg); |
1156 | if (rc) { |
1157 | ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet " |
1158 | "from the user space daemon\n" ); |
1159 | rc = -EIO; |
1160 | goto out; |
1161 | } |
1162 | rc = parse_tag_65_packet(session_key: &(auth_tok->session_key), |
1163 | cipher_code: &cipher_code, msg); |
1164 | if (rc) { |
1165 | printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n" , |
1166 | rc); |
1167 | goto out; |
1168 | } |
1169 | auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; |
1170 | memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, |
1171 | auth_tok->session_key.decrypted_key_size); |
1172 | crypt_stat->key_size = auth_tok->session_key.decrypted_key_size; |
1173 | rc = ecryptfs_cipher_code_to_string(str: crypt_stat->cipher, cipher_code); |
1174 | if (rc) { |
1175 | ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n" , |
1176 | cipher_code); |
1177 | goto out; |
1178 | } |
1179 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; |
1180 | if (ecryptfs_verbosity > 0) { |
1181 | ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n" ); |
1182 | ecryptfs_dump_hex(data: crypt_stat->key, |
1183 | bytes: crypt_stat->key_size); |
1184 | } |
1185 | out: |
1186 | kfree(objp: msg); |
1187 | kfree(objp: payload); |
1188 | return rc; |
1189 | } |
1190 | |
1191 | static void wipe_auth_tok_list(struct list_head *auth_tok_list_head) |
1192 | { |
1193 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
1194 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
1195 | |
1196 | list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp, |
1197 | auth_tok_list_head, list) { |
1198 | list_del(entry: &auth_tok_list_item->list); |
1199 | kmem_cache_free(s: ecryptfs_auth_tok_list_item_cache, |
1200 | objp: auth_tok_list_item); |
1201 | } |
1202 | } |
1203 | |
1204 | struct kmem_cache *ecryptfs_auth_tok_list_item_cache; |
1205 | |
1206 | /** |
1207 | * parse_tag_1_packet |
1208 | * @crypt_stat: The cryptographic context to modify based on packet contents |
1209 | * @data: The raw bytes of the packet. |
1210 | * @auth_tok_list: eCryptfs parses packets into authentication tokens; |
1211 | * a new authentication token will be placed at the |
1212 | * end of this list for this packet. |
1213 | * @new_auth_tok: Pointer to a pointer to memory that this function |
1214 | * allocates; sets the memory address of the pointer to |
1215 | * NULL on error. This object is added to the |
1216 | * auth_tok_list. |
1217 | * @packet_size: This function writes the size of the parsed packet |
1218 | * into this memory location; zero on error. |
1219 | * @max_packet_size: The maximum allowable packet size |
1220 | * |
1221 | * Returns zero on success; non-zero on error. |
1222 | */ |
1223 | static int |
1224 | parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat, |
1225 | unsigned char *data, struct list_head *auth_tok_list, |
1226 | struct ecryptfs_auth_tok **new_auth_tok, |
1227 | size_t *packet_size, size_t max_packet_size) |
1228 | { |
1229 | size_t body_size; |
1230 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
1231 | size_t length_size; |
1232 | int rc = 0; |
1233 | |
1234 | (*packet_size) = 0; |
1235 | (*new_auth_tok) = NULL; |
1236 | /** |
1237 | * This format is inspired by OpenPGP; see RFC 2440 |
1238 | * packet tag 1 |
1239 | * |
1240 | * Tag 1 identifier (1 byte) |
1241 | * Max Tag 1 packet size (max 3 bytes) |
1242 | * Version (1 byte) |
1243 | * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE) |
1244 | * Cipher identifier (1 byte) |
1245 | * Encrypted key size (arbitrary) |
1246 | * |
1247 | * 12 bytes minimum packet size |
1248 | */ |
1249 | if (unlikely(max_packet_size < 12)) { |
1250 | printk(KERN_ERR "Invalid max packet size; must be >=12\n" ); |
1251 | rc = -EINVAL; |
1252 | goto out; |
1253 | } |
1254 | if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) { |
1255 | printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n" , |
1256 | ECRYPTFS_TAG_1_PACKET_TYPE); |
1257 | rc = -EINVAL; |
1258 | goto out; |
1259 | } |
1260 | /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or |
1261 | * at end of function upon failure */ |
1262 | auth_tok_list_item = |
1263 | kmem_cache_zalloc(k: ecryptfs_auth_tok_list_item_cache, |
1264 | GFP_KERNEL); |
1265 | if (!auth_tok_list_item) { |
1266 | printk(KERN_ERR "Unable to allocate memory\n" ); |
1267 | rc = -ENOMEM; |
1268 | goto out; |
1269 | } |
1270 | (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
1271 | rc = ecryptfs_parse_packet_length(data: &data[(*packet_size)], size: &body_size, |
1272 | length_size: &length_size); |
1273 | if (rc) { |
1274 | printk(KERN_WARNING "Error parsing packet length; " |
1275 | "rc = [%d]\n" , rc); |
1276 | goto out_free; |
1277 | } |
1278 | if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) { |
1279 | printk(KERN_WARNING "Invalid body size ([%td])\n" , body_size); |
1280 | rc = -EINVAL; |
1281 | goto out_free; |
1282 | } |
1283 | (*packet_size) += length_size; |
1284 | if (unlikely((*packet_size) + body_size > max_packet_size)) { |
1285 | printk(KERN_WARNING "Packet size exceeds max\n" ); |
1286 | rc = -EINVAL; |
1287 | goto out_free; |
1288 | } |
1289 | if (unlikely(data[(*packet_size)++] != 0x03)) { |
1290 | printk(KERN_WARNING "Unknown version number [%d]\n" , |
1291 | data[(*packet_size) - 1]); |
1292 | rc = -EINVAL; |
1293 | goto out_free; |
1294 | } |
1295 | ecryptfs_to_hex(dst: (*new_auth_tok)->token.private_key.signature, |
1296 | src: &data[(*packet_size)], ECRYPTFS_SIG_SIZE); |
1297 | *packet_size += ECRYPTFS_SIG_SIZE; |
1298 | /* This byte is skipped because the kernel does not need to |
1299 | * know which public key encryption algorithm was used */ |
1300 | (*packet_size)++; |
1301 | (*new_auth_tok)->session_key.encrypted_key_size = |
1302 | body_size - (ECRYPTFS_SIG_SIZE + 2); |
1303 | if ((*new_auth_tok)->session_key.encrypted_key_size |
1304 | > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { |
1305 | printk(KERN_WARNING "Tag 1 packet contains key larger " |
1306 | "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n" ); |
1307 | rc = -EINVAL; |
1308 | goto out_free; |
1309 | } |
1310 | memcpy((*new_auth_tok)->session_key.encrypted_key, |
1311 | &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2))); |
1312 | (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size; |
1313 | (*new_auth_tok)->session_key.flags &= |
1314 | ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; |
1315 | (*new_auth_tok)->session_key.flags |= |
1316 | ECRYPTFS_CONTAINS_ENCRYPTED_KEY; |
1317 | (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY; |
1318 | (*new_auth_tok)->flags = 0; |
1319 | (*new_auth_tok)->session_key.flags &= |
1320 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT); |
1321 | (*new_auth_tok)->session_key.flags &= |
1322 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT); |
1323 | list_add(new: &auth_tok_list_item->list, head: auth_tok_list); |
1324 | goto out; |
1325 | out_free: |
1326 | (*new_auth_tok) = NULL; |
1327 | memset(auth_tok_list_item, 0, |
1328 | sizeof(struct ecryptfs_auth_tok_list_item)); |
1329 | kmem_cache_free(s: ecryptfs_auth_tok_list_item_cache, |
1330 | objp: auth_tok_list_item); |
1331 | out: |
1332 | if (rc) |
1333 | (*packet_size) = 0; |
1334 | return rc; |
1335 | } |
1336 | |
1337 | /** |
1338 | * parse_tag_3_packet |
1339 | * @crypt_stat: The cryptographic context to modify based on packet |
1340 | * contents. |
1341 | * @data: The raw bytes of the packet. |
1342 | * @auth_tok_list: eCryptfs parses packets into authentication tokens; |
1343 | * a new authentication token will be placed at the end |
1344 | * of this list for this packet. |
1345 | * @new_auth_tok: Pointer to a pointer to memory that this function |
1346 | * allocates; sets the memory address of the pointer to |
1347 | * NULL on error. This object is added to the |
1348 | * auth_tok_list. |
1349 | * @packet_size: This function writes the size of the parsed packet |
1350 | * into this memory location; zero on error. |
1351 | * @max_packet_size: maximum number of bytes to parse |
1352 | * |
1353 | * Returns zero on success; non-zero on error. |
1354 | */ |
1355 | static int |
1356 | parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat, |
1357 | unsigned char *data, struct list_head *auth_tok_list, |
1358 | struct ecryptfs_auth_tok **new_auth_tok, |
1359 | size_t *packet_size, size_t max_packet_size) |
1360 | { |
1361 | size_t body_size; |
1362 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
1363 | size_t length_size; |
1364 | int rc = 0; |
1365 | |
1366 | (*packet_size) = 0; |
1367 | (*new_auth_tok) = NULL; |
1368 | /** |
1369 | *This format is inspired by OpenPGP; see RFC 2440 |
1370 | * packet tag 3 |
1371 | * |
1372 | * Tag 3 identifier (1 byte) |
1373 | * Max Tag 3 packet size (max 3 bytes) |
1374 | * Version (1 byte) |
1375 | * Cipher code (1 byte) |
1376 | * S2K specifier (1 byte) |
1377 | * Hash identifier (1 byte) |
1378 | * Salt (ECRYPTFS_SALT_SIZE) |
1379 | * Hash iterations (1 byte) |
1380 | * Encrypted key (arbitrary) |
1381 | * |
1382 | * (ECRYPTFS_SALT_SIZE + 7) minimum packet size |
1383 | */ |
1384 | if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) { |
1385 | printk(KERN_ERR "Max packet size too large\n" ); |
1386 | rc = -EINVAL; |
1387 | goto out; |
1388 | } |
1389 | if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) { |
1390 | printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n" , |
1391 | ECRYPTFS_TAG_3_PACKET_TYPE); |
1392 | rc = -EINVAL; |
1393 | goto out; |
1394 | } |
1395 | /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or |
1396 | * at end of function upon failure */ |
1397 | auth_tok_list_item = |
1398 | kmem_cache_zalloc(k: ecryptfs_auth_tok_list_item_cache, GFP_KERNEL); |
1399 | if (!auth_tok_list_item) { |
1400 | printk(KERN_ERR "Unable to allocate memory\n" ); |
1401 | rc = -ENOMEM; |
1402 | goto out; |
1403 | } |
1404 | (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
1405 | rc = ecryptfs_parse_packet_length(data: &data[(*packet_size)], size: &body_size, |
1406 | length_size: &length_size); |
1407 | if (rc) { |
1408 | printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n" , |
1409 | rc); |
1410 | goto out_free; |
1411 | } |
1412 | if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) { |
1413 | printk(KERN_WARNING "Invalid body size ([%td])\n" , body_size); |
1414 | rc = -EINVAL; |
1415 | goto out_free; |
1416 | } |
1417 | (*packet_size) += length_size; |
1418 | if (unlikely((*packet_size) + body_size > max_packet_size)) { |
1419 | printk(KERN_ERR "Packet size exceeds max\n" ); |
1420 | rc = -EINVAL; |
1421 | goto out_free; |
1422 | } |
1423 | (*new_auth_tok)->session_key.encrypted_key_size = |
1424 | (body_size - (ECRYPTFS_SALT_SIZE + 5)); |
1425 | if ((*new_auth_tok)->session_key.encrypted_key_size |
1426 | > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { |
1427 | printk(KERN_WARNING "Tag 3 packet contains key larger " |
1428 | "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n" ); |
1429 | rc = -EINVAL; |
1430 | goto out_free; |
1431 | } |
1432 | if (unlikely(data[(*packet_size)++] != 0x04)) { |
1433 | printk(KERN_WARNING "Unknown version number [%d]\n" , |
1434 | data[(*packet_size) - 1]); |
1435 | rc = -EINVAL; |
1436 | goto out_free; |
1437 | } |
1438 | rc = ecryptfs_cipher_code_to_string(str: crypt_stat->cipher, |
1439 | cipher_code: (u16)data[(*packet_size)]); |
1440 | if (rc) |
1441 | goto out_free; |
1442 | /* A little extra work to differentiate among the AES key |
1443 | * sizes; see RFC2440 */ |
1444 | switch(data[(*packet_size)++]) { |
1445 | case RFC2440_CIPHER_AES_192: |
1446 | crypt_stat->key_size = 24; |
1447 | break; |
1448 | default: |
1449 | crypt_stat->key_size = |
1450 | (*new_auth_tok)->session_key.encrypted_key_size; |
1451 | } |
1452 | rc = ecryptfs_init_crypt_ctx(crypt_stat); |
1453 | if (rc) |
1454 | goto out_free; |
1455 | if (unlikely(data[(*packet_size)++] != 0x03)) { |
1456 | printk(KERN_WARNING "Only S2K ID 3 is currently supported\n" ); |
1457 | rc = -ENOSYS; |
1458 | goto out_free; |
1459 | } |
1460 | /* TODO: finish the hash mapping */ |
1461 | switch (data[(*packet_size)++]) { |
1462 | case 0x01: /* See RFC2440 for these numbers and their mappings */ |
1463 | /* Choose MD5 */ |
1464 | memcpy((*new_auth_tok)->token.password.salt, |
1465 | &data[(*packet_size)], ECRYPTFS_SALT_SIZE); |
1466 | (*packet_size) += ECRYPTFS_SALT_SIZE; |
1467 | /* This conversion was taken straight from RFC2440 */ |
1468 | (*new_auth_tok)->token.password.hash_iterations = |
1469 | ((u32) 16 + (data[(*packet_size)] & 15)) |
1470 | << ((data[(*packet_size)] >> 4) + 6); |
1471 | (*packet_size)++; |
1472 | /* Friendly reminder: |
1473 | * (*new_auth_tok)->session_key.encrypted_key_size = |
1474 | * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */ |
1475 | memcpy((*new_auth_tok)->session_key.encrypted_key, |
1476 | &data[(*packet_size)], |
1477 | (*new_auth_tok)->session_key.encrypted_key_size); |
1478 | (*packet_size) += |
1479 | (*new_auth_tok)->session_key.encrypted_key_size; |
1480 | (*new_auth_tok)->session_key.flags &= |
1481 | ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; |
1482 | (*new_auth_tok)->session_key.flags |= |
1483 | ECRYPTFS_CONTAINS_ENCRYPTED_KEY; |
1484 | (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */ |
1485 | break; |
1486 | default: |
1487 | ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: " |
1488 | "[%d]\n" , data[(*packet_size) - 1]); |
1489 | rc = -ENOSYS; |
1490 | goto out_free; |
1491 | } |
1492 | (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD; |
1493 | /* TODO: Parametarize; we might actually want userspace to |
1494 | * decrypt the session key. */ |
1495 | (*new_auth_tok)->session_key.flags &= |
1496 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT); |
1497 | (*new_auth_tok)->session_key.flags &= |
1498 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT); |
1499 | list_add(new: &auth_tok_list_item->list, head: auth_tok_list); |
1500 | goto out; |
1501 | out_free: |
1502 | (*new_auth_tok) = NULL; |
1503 | memset(auth_tok_list_item, 0, |
1504 | sizeof(struct ecryptfs_auth_tok_list_item)); |
1505 | kmem_cache_free(s: ecryptfs_auth_tok_list_item_cache, |
1506 | objp: auth_tok_list_item); |
1507 | out: |
1508 | if (rc) |
1509 | (*packet_size) = 0; |
1510 | return rc; |
1511 | } |
1512 | |
1513 | /** |
1514 | * parse_tag_11_packet |
1515 | * @data: The raw bytes of the packet |
1516 | * @contents: This function writes the data contents of the literal |
1517 | * packet into this memory location |
1518 | * @max_contents_bytes: The maximum number of bytes that this function |
1519 | * is allowed to write into contents |
1520 | * @tag_11_contents_size: This function writes the size of the parsed |
1521 | * contents into this memory location; zero on |
1522 | * error |
1523 | * @packet_size: This function writes the size of the parsed packet |
1524 | * into this memory location; zero on error |
1525 | * @max_packet_size: maximum number of bytes to parse |
1526 | * |
1527 | * Returns zero on success; non-zero on error. |
1528 | */ |
1529 | static int |
1530 | parse_tag_11_packet(unsigned char *data, unsigned char *contents, |
1531 | size_t max_contents_bytes, size_t *tag_11_contents_size, |
1532 | size_t *packet_size, size_t max_packet_size) |
1533 | { |
1534 | size_t body_size; |
1535 | size_t length_size; |
1536 | int rc = 0; |
1537 | |
1538 | (*packet_size) = 0; |
1539 | (*tag_11_contents_size) = 0; |
1540 | /* This format is inspired by OpenPGP; see RFC 2440 |
1541 | * packet tag 11 |
1542 | * |
1543 | * Tag 11 identifier (1 byte) |
1544 | * Max Tag 11 packet size (max 3 bytes) |
1545 | * Binary format specifier (1 byte) |
1546 | * Filename length (1 byte) |
1547 | * Filename ("_CONSOLE") (8 bytes) |
1548 | * Modification date (4 bytes) |
1549 | * Literal data (arbitrary) |
1550 | * |
1551 | * We need at least 16 bytes of data for the packet to even be |
1552 | * valid. |
1553 | */ |
1554 | if (max_packet_size < 16) { |
1555 | printk(KERN_ERR "Maximum packet size too small\n" ); |
1556 | rc = -EINVAL; |
1557 | goto out; |
1558 | } |
1559 | if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) { |
1560 | printk(KERN_WARNING "Invalid tag 11 packet format\n" ); |
1561 | rc = -EINVAL; |
1562 | goto out; |
1563 | } |
1564 | rc = ecryptfs_parse_packet_length(data: &data[(*packet_size)], size: &body_size, |
1565 | length_size: &length_size); |
1566 | if (rc) { |
1567 | printk(KERN_WARNING "Invalid tag 11 packet format\n" ); |
1568 | goto out; |
1569 | } |
1570 | if (body_size < 14) { |
1571 | printk(KERN_WARNING "Invalid body size ([%td])\n" , body_size); |
1572 | rc = -EINVAL; |
1573 | goto out; |
1574 | } |
1575 | (*packet_size) += length_size; |
1576 | (*tag_11_contents_size) = (body_size - 14); |
1577 | if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) { |
1578 | printk(KERN_ERR "Packet size exceeds max\n" ); |
1579 | rc = -EINVAL; |
1580 | goto out; |
1581 | } |
1582 | if (unlikely((*tag_11_contents_size) > max_contents_bytes)) { |
1583 | printk(KERN_ERR "Literal data section in tag 11 packet exceeds " |
1584 | "expected size\n" ); |
1585 | rc = -EINVAL; |
1586 | goto out; |
1587 | } |
1588 | if (data[(*packet_size)++] != 0x62) { |
1589 | printk(KERN_WARNING "Unrecognizable packet\n" ); |
1590 | rc = -EINVAL; |
1591 | goto out; |
1592 | } |
1593 | if (data[(*packet_size)++] != 0x08) { |
1594 | printk(KERN_WARNING "Unrecognizable packet\n" ); |
1595 | rc = -EINVAL; |
1596 | goto out; |
1597 | } |
1598 | (*packet_size) += 12; /* Ignore filename and modification date */ |
1599 | memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size)); |
1600 | (*packet_size) += (*tag_11_contents_size); |
1601 | out: |
1602 | if (rc) { |
1603 | (*packet_size) = 0; |
1604 | (*tag_11_contents_size) = 0; |
1605 | } |
1606 | return rc; |
1607 | } |
1608 | |
1609 | int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key, |
1610 | struct ecryptfs_auth_tok **auth_tok, |
1611 | char *sig) |
1612 | { |
1613 | int rc = 0; |
1614 | |
1615 | (*auth_tok_key) = request_key(type: &key_type_user, description: sig, NULL); |
1616 | if (IS_ERR(ptr: *auth_tok_key)) { |
1617 | (*auth_tok_key) = ecryptfs_get_encrypted_key(sig); |
1618 | if (IS_ERR(ptr: *auth_tok_key)) { |
1619 | printk(KERN_ERR "Could not find key with description: [%s]\n" , |
1620 | sig); |
1621 | rc = process_request_key_err(err_code: PTR_ERR(ptr: *auth_tok_key)); |
1622 | (*auth_tok_key) = NULL; |
1623 | goto out; |
1624 | } |
1625 | } |
1626 | down_write(sem: &(*auth_tok_key)->sem); |
1627 | rc = ecryptfs_verify_auth_tok_from_key(auth_tok_key: *auth_tok_key, auth_tok); |
1628 | if (rc) { |
1629 | up_write(sem: &(*auth_tok_key)->sem); |
1630 | key_put(key: *auth_tok_key); |
1631 | (*auth_tok_key) = NULL; |
1632 | goto out; |
1633 | } |
1634 | out: |
1635 | return rc; |
1636 | } |
1637 | |
1638 | /** |
1639 | * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok. |
1640 | * @auth_tok: The passphrase authentication token to use to encrypt the FEK |
1641 | * @crypt_stat: The cryptographic context |
1642 | * |
1643 | * Returns zero on success; non-zero error otherwise |
1644 | */ |
1645 | static int |
1646 | decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, |
1647 | struct ecryptfs_crypt_stat *crypt_stat) |
1648 | { |
1649 | struct scatterlist dst_sg[2]; |
1650 | struct scatterlist src_sg[2]; |
1651 | struct mutex *tfm_mutex; |
1652 | struct crypto_skcipher *tfm; |
1653 | struct skcipher_request *req = NULL; |
1654 | int rc = 0; |
1655 | |
1656 | if (unlikely(ecryptfs_verbosity > 0)) { |
1657 | ecryptfs_printk( |
1658 | KERN_DEBUG, "Session key encryption key (size [%d]):\n" , |
1659 | auth_tok->token.password.session_key_encryption_key_bytes); |
1660 | ecryptfs_dump_hex( |
1661 | data: auth_tok->token.password.session_key_encryption_key, |
1662 | bytes: auth_tok->token.password.session_key_encryption_key_bytes); |
1663 | } |
1664 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(tfm: &tfm, tfm_mutex: &tfm_mutex, |
1665 | cipher_name: crypt_stat->cipher); |
1666 | if (unlikely(rc)) { |
1667 | printk(KERN_ERR "Internal error whilst attempting to get " |
1668 | "tfm and mutex for cipher name [%s]; rc = [%d]\n" , |
1669 | crypt_stat->cipher, rc); |
1670 | goto out; |
1671 | } |
1672 | rc = virt_to_scatterlist(addr: auth_tok->session_key.encrypted_key, |
1673 | size: auth_tok->session_key.encrypted_key_size, |
1674 | sg: src_sg, sg_size: 2); |
1675 | if (rc < 1 || rc > 2) { |
1676 | printk(KERN_ERR "Internal error whilst attempting to convert " |
1677 | "auth_tok->session_key.encrypted_key to scatterlist; " |
1678 | "expected rc = 1; got rc = [%d]. " |
1679 | "auth_tok->session_key.encrypted_key_size = [%d]\n" , rc, |
1680 | auth_tok->session_key.encrypted_key_size); |
1681 | goto out; |
1682 | } |
1683 | auth_tok->session_key.decrypted_key_size = |
1684 | auth_tok->session_key.encrypted_key_size; |
1685 | rc = virt_to_scatterlist(addr: auth_tok->session_key.decrypted_key, |
1686 | size: auth_tok->session_key.decrypted_key_size, |
1687 | sg: dst_sg, sg_size: 2); |
1688 | if (rc < 1 || rc > 2) { |
1689 | printk(KERN_ERR "Internal error whilst attempting to convert " |
1690 | "auth_tok->session_key.decrypted_key to scatterlist; " |
1691 | "expected rc = 1; got rc = [%d]\n" , rc); |
1692 | goto out; |
1693 | } |
1694 | mutex_lock(tfm_mutex); |
1695 | req = skcipher_request_alloc(tfm, GFP_KERNEL); |
1696 | if (!req) { |
1697 | mutex_unlock(lock: tfm_mutex); |
1698 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " |
1699 | "skcipher_request_alloc for %s\n" , __func__, |
1700 | crypto_skcipher_driver_name(tfm)); |
1701 | rc = -ENOMEM; |
1702 | goto out; |
1703 | } |
1704 | |
1705 | skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, |
1706 | NULL, NULL); |
1707 | rc = crypto_skcipher_setkey( |
1708 | tfm, key: auth_tok->token.password.session_key_encryption_key, |
1709 | keylen: crypt_stat->key_size); |
1710 | if (unlikely(rc < 0)) { |
1711 | mutex_unlock(lock: tfm_mutex); |
1712 | printk(KERN_ERR "Error setting key for crypto context\n" ); |
1713 | rc = -EINVAL; |
1714 | goto out; |
1715 | } |
1716 | skcipher_request_set_crypt(req, src: src_sg, dst: dst_sg, |
1717 | cryptlen: auth_tok->session_key.encrypted_key_size, |
1718 | NULL); |
1719 | rc = crypto_skcipher_decrypt(req); |
1720 | mutex_unlock(lock: tfm_mutex); |
1721 | if (unlikely(rc)) { |
1722 | printk(KERN_ERR "Error decrypting; rc = [%d]\n" , rc); |
1723 | goto out; |
1724 | } |
1725 | auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; |
1726 | memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, |
1727 | auth_tok->session_key.decrypted_key_size); |
1728 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; |
1729 | if (unlikely(ecryptfs_verbosity > 0)) { |
1730 | ecryptfs_printk(KERN_DEBUG, "FEK of size [%zd]:\n" , |
1731 | crypt_stat->key_size); |
1732 | ecryptfs_dump_hex(data: crypt_stat->key, |
1733 | bytes: crypt_stat->key_size); |
1734 | } |
1735 | out: |
1736 | skcipher_request_free(req); |
1737 | return rc; |
1738 | } |
1739 | |
1740 | /** |
1741 | * ecryptfs_parse_packet_set |
1742 | * @crypt_stat: The cryptographic context |
1743 | * @src: Virtual address of region of memory containing the packets |
1744 | * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set |
1745 | * |
1746 | * Get crypt_stat to have the file's session key if the requisite key |
1747 | * is available to decrypt the session key. |
1748 | * |
1749 | * Returns Zero if a valid authentication token was retrieved and |
1750 | * processed; negative value for file not encrypted or for error |
1751 | * conditions. |
1752 | */ |
1753 | int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat, |
1754 | unsigned char *src, |
1755 | struct dentry *ecryptfs_dentry) |
1756 | { |
1757 | size_t i = 0; |
1758 | size_t found_auth_tok; |
1759 | size_t next_packet_is_auth_tok_packet; |
1760 | struct list_head auth_tok_list; |
1761 | struct ecryptfs_auth_tok *matching_auth_tok; |
1762 | struct ecryptfs_auth_tok *candidate_auth_tok; |
1763 | char *candidate_auth_tok_sig; |
1764 | size_t packet_size; |
1765 | struct ecryptfs_auth_tok *new_auth_tok; |
1766 | unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE]; |
1767 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
1768 | size_t tag_11_contents_size; |
1769 | size_t tag_11_packet_size; |
1770 | struct key *auth_tok_key = NULL; |
1771 | int rc = 0; |
1772 | |
1773 | INIT_LIST_HEAD(list: &auth_tok_list); |
1774 | /* Parse the header to find as many packets as we can; these will be |
1775 | * added the our &auth_tok_list */ |
1776 | next_packet_is_auth_tok_packet = 1; |
1777 | while (next_packet_is_auth_tok_packet) { |
1778 | size_t max_packet_size = ((PAGE_SIZE - 8) - i); |
1779 | |
1780 | switch (src[i]) { |
1781 | case ECRYPTFS_TAG_3_PACKET_TYPE: |
1782 | rc = parse_tag_3_packet(crypt_stat, |
1783 | data: (unsigned char *)&src[i], |
1784 | auth_tok_list: &auth_tok_list, new_auth_tok: &new_auth_tok, |
1785 | packet_size: &packet_size, max_packet_size); |
1786 | if (rc) { |
1787 | ecryptfs_printk(KERN_ERR, "Error parsing " |
1788 | "tag 3 packet\n" ); |
1789 | rc = -EIO; |
1790 | goto out_wipe_list; |
1791 | } |
1792 | i += packet_size; |
1793 | rc = parse_tag_11_packet(data: (unsigned char *)&src[i], |
1794 | contents: sig_tmp_space, |
1795 | ECRYPTFS_SIG_SIZE, |
1796 | tag_11_contents_size: &tag_11_contents_size, |
1797 | packet_size: &tag_11_packet_size, |
1798 | max_packet_size); |
1799 | if (rc) { |
1800 | ecryptfs_printk(KERN_ERR, "No valid " |
1801 | "(ecryptfs-specific) literal " |
1802 | "packet containing " |
1803 | "authentication token " |
1804 | "signature found after " |
1805 | "tag 3 packet\n" ); |
1806 | rc = -EIO; |
1807 | goto out_wipe_list; |
1808 | } |
1809 | i += tag_11_packet_size; |
1810 | if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) { |
1811 | ecryptfs_printk(KERN_ERR, "Expected " |
1812 | "signature of size [%d]; " |
1813 | "read size [%zd]\n" , |
1814 | ECRYPTFS_SIG_SIZE, |
1815 | tag_11_contents_size); |
1816 | rc = -EIO; |
1817 | goto out_wipe_list; |
1818 | } |
1819 | ecryptfs_to_hex(dst: new_auth_tok->token.password.signature, |
1820 | src: sig_tmp_space, src_size: tag_11_contents_size); |
1821 | new_auth_tok->token.password.signature[ |
1822 | ECRYPTFS_PASSWORD_SIG_SIZE] = '\0'; |
1823 | crypt_stat->flags |= ECRYPTFS_ENCRYPTED; |
1824 | break; |
1825 | case ECRYPTFS_TAG_1_PACKET_TYPE: |
1826 | rc = parse_tag_1_packet(crypt_stat, |
1827 | data: (unsigned char *)&src[i], |
1828 | auth_tok_list: &auth_tok_list, new_auth_tok: &new_auth_tok, |
1829 | packet_size: &packet_size, max_packet_size); |
1830 | if (rc) { |
1831 | ecryptfs_printk(KERN_ERR, "Error parsing " |
1832 | "tag 1 packet\n" ); |
1833 | rc = -EIO; |
1834 | goto out_wipe_list; |
1835 | } |
1836 | i += packet_size; |
1837 | crypt_stat->flags |= ECRYPTFS_ENCRYPTED; |
1838 | break; |
1839 | case ECRYPTFS_TAG_11_PACKET_TYPE: |
1840 | ecryptfs_printk(KERN_WARNING, "Invalid packet set " |
1841 | "(Tag 11 not allowed by itself)\n" ); |
1842 | rc = -EIO; |
1843 | goto out_wipe_list; |
1844 | default: |
1845 | ecryptfs_printk(KERN_DEBUG, "No packet at offset [%zd] " |
1846 | "of the file header; hex value of " |
1847 | "character is [0x%.2x]\n" , i, src[i]); |
1848 | next_packet_is_auth_tok_packet = 0; |
1849 | } |
1850 | } |
1851 | if (list_empty(head: &auth_tok_list)) { |
1852 | printk(KERN_ERR "The lower file appears to be a non-encrypted " |
1853 | "eCryptfs file; this is not supported in this version " |
1854 | "of the eCryptfs kernel module\n" ); |
1855 | rc = -EINVAL; |
1856 | goto out; |
1857 | } |
1858 | /* auth_tok_list contains the set of authentication tokens |
1859 | * parsed from the metadata. We need to find a matching |
1860 | * authentication token that has the secret component(s) |
1861 | * necessary to decrypt the EFEK in the auth_tok parsed from |
1862 | * the metadata. There may be several potential matches, but |
1863 | * just one will be sufficient to decrypt to get the FEK. */ |
1864 | find_next_matching_auth_tok: |
1865 | found_auth_tok = 0; |
1866 | list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) { |
1867 | candidate_auth_tok = &auth_tok_list_item->auth_tok; |
1868 | if (unlikely(ecryptfs_verbosity > 0)) { |
1869 | ecryptfs_printk(KERN_DEBUG, |
1870 | "Considering candidate auth tok:\n" ); |
1871 | ecryptfs_dump_auth_tok(auth_tok: candidate_auth_tok); |
1872 | } |
1873 | rc = ecryptfs_get_auth_tok_sig(sig: &candidate_auth_tok_sig, |
1874 | auth_tok: candidate_auth_tok); |
1875 | if (rc) { |
1876 | printk(KERN_ERR |
1877 | "Unrecognized candidate auth tok type: [%d]\n" , |
1878 | candidate_auth_tok->token_type); |
1879 | rc = -EINVAL; |
1880 | goto out_wipe_list; |
1881 | } |
1882 | rc = ecryptfs_find_auth_tok_for_sig(auth_tok_key: &auth_tok_key, |
1883 | auth_tok: &matching_auth_tok, |
1884 | mount_crypt_stat: crypt_stat->mount_crypt_stat, |
1885 | sig: candidate_auth_tok_sig); |
1886 | if (!rc) { |
1887 | found_auth_tok = 1; |
1888 | goto found_matching_auth_tok; |
1889 | } |
1890 | } |
1891 | if (!found_auth_tok) { |
1892 | ecryptfs_printk(KERN_ERR, "Could not find a usable " |
1893 | "authentication token\n" ); |
1894 | rc = -EIO; |
1895 | goto out_wipe_list; |
1896 | } |
1897 | found_matching_auth_tok: |
1898 | if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
1899 | memcpy(&(candidate_auth_tok->token.private_key), |
1900 | &(matching_auth_tok->token.private_key), |
1901 | sizeof(struct ecryptfs_private_key)); |
1902 | up_write(sem: &(auth_tok_key->sem)); |
1903 | key_put(key: auth_tok_key); |
1904 | rc = decrypt_pki_encrypted_session_key(auth_tok: candidate_auth_tok, |
1905 | crypt_stat); |
1906 | } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) { |
1907 | memcpy(&(candidate_auth_tok->token.password), |
1908 | &(matching_auth_tok->token.password), |
1909 | sizeof(struct ecryptfs_password)); |
1910 | up_write(sem: &(auth_tok_key->sem)); |
1911 | key_put(key: auth_tok_key); |
1912 | rc = decrypt_passphrase_encrypted_session_key( |
1913 | auth_tok: candidate_auth_tok, crypt_stat); |
1914 | } else { |
1915 | up_write(sem: &(auth_tok_key->sem)); |
1916 | key_put(key: auth_tok_key); |
1917 | rc = -EINVAL; |
1918 | } |
1919 | if (rc) { |
1920 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
1921 | |
1922 | ecryptfs_printk(KERN_WARNING, "Error decrypting the " |
1923 | "session key for authentication token with sig " |
1924 | "[%.*s]; rc = [%d]. Removing auth tok " |
1925 | "candidate from the list and searching for " |
1926 | "the next match.\n" , ECRYPTFS_SIG_SIZE_HEX, |
1927 | candidate_auth_tok_sig, rc); |
1928 | list_for_each_entry_safe(auth_tok_list_item, |
1929 | auth_tok_list_item_tmp, |
1930 | &auth_tok_list, list) { |
1931 | if (candidate_auth_tok |
1932 | == &auth_tok_list_item->auth_tok) { |
1933 | list_del(entry: &auth_tok_list_item->list); |
1934 | kmem_cache_free( |
1935 | s: ecryptfs_auth_tok_list_item_cache, |
1936 | objp: auth_tok_list_item); |
1937 | goto find_next_matching_auth_tok; |
1938 | } |
1939 | } |
1940 | BUG(); |
1941 | } |
1942 | rc = ecryptfs_compute_root_iv(crypt_stat); |
1943 | if (rc) { |
1944 | ecryptfs_printk(KERN_ERR, "Error computing " |
1945 | "the root IV\n" ); |
1946 | goto out_wipe_list; |
1947 | } |
1948 | rc = ecryptfs_init_crypt_ctx(crypt_stat); |
1949 | if (rc) { |
1950 | ecryptfs_printk(KERN_ERR, "Error initializing crypto " |
1951 | "context for cipher [%s]; rc = [%d]\n" , |
1952 | crypt_stat->cipher, rc); |
1953 | } |
1954 | out_wipe_list: |
1955 | wipe_auth_tok_list(auth_tok_list_head: &auth_tok_list); |
1956 | out: |
1957 | return rc; |
1958 | } |
1959 | |
1960 | static int |
1961 | pki_encrypt_session_key(struct key *auth_tok_key, |
1962 | struct ecryptfs_auth_tok *auth_tok, |
1963 | struct ecryptfs_crypt_stat *crypt_stat, |
1964 | struct ecryptfs_key_record *key_rec) |
1965 | { |
1966 | struct ecryptfs_msg_ctx *msg_ctx = NULL; |
1967 | char *payload = NULL; |
1968 | size_t payload_len = 0; |
1969 | struct ecryptfs_message *msg; |
1970 | int rc; |
1971 | |
1972 | rc = write_tag_66_packet(signature: auth_tok->token.private_key.signature, |
1973 | cipher_code: ecryptfs_code_for_cipher_string( |
1974 | cipher_name: crypt_stat->cipher, |
1975 | key_bytes: crypt_stat->key_size), |
1976 | crypt_stat, packet: &payload, packet_len: &payload_len); |
1977 | up_write(sem: &(auth_tok_key->sem)); |
1978 | key_put(key: auth_tok_key); |
1979 | if (rc) { |
1980 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n" ); |
1981 | goto out; |
1982 | } |
1983 | rc = ecryptfs_send_message(data: payload, data_len: payload_len, msg_ctx: &msg_ctx); |
1984 | if (rc) { |
1985 | ecryptfs_printk(KERN_ERR, "Error sending message to " |
1986 | "ecryptfsd: %d\n" , rc); |
1987 | goto out; |
1988 | } |
1989 | rc = ecryptfs_wait_for_response(msg_ctx, emsg: &msg); |
1990 | if (rc) { |
1991 | ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet " |
1992 | "from the user space daemon\n" ); |
1993 | rc = -EIO; |
1994 | goto out; |
1995 | } |
1996 | rc = parse_tag_67_packet(key_rec, msg); |
1997 | if (rc) |
1998 | ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n" ); |
1999 | kfree(objp: msg); |
2000 | out: |
2001 | kfree(objp: payload); |
2002 | return rc; |
2003 | } |
2004 | /** |
2005 | * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet |
2006 | * @dest: Buffer into which to write the packet |
2007 | * @remaining_bytes: Maximum number of bytes that can be writtn |
2008 | * @auth_tok_key: The authentication token key to unlock and put when done with |
2009 | * @auth_tok |
2010 | * @auth_tok: The authentication token used for generating the tag 1 packet |
2011 | * @crypt_stat: The cryptographic context |
2012 | * @key_rec: The key record struct for the tag 1 packet |
2013 | * @packet_size: This function will write the number of bytes that end |
2014 | * up constituting the packet; set to zero on error |
2015 | * |
2016 | * Returns zero on success; non-zero on error. |
2017 | */ |
2018 | static int |
2019 | write_tag_1_packet(char *dest, size_t *remaining_bytes, |
2020 | struct key *auth_tok_key, struct ecryptfs_auth_tok *auth_tok, |
2021 | struct ecryptfs_crypt_stat *crypt_stat, |
2022 | struct ecryptfs_key_record *key_rec, size_t *packet_size) |
2023 | { |
2024 | size_t i; |
2025 | size_t encrypted_session_key_valid = 0; |
2026 | size_t packet_size_length; |
2027 | size_t max_packet_size; |
2028 | int rc = 0; |
2029 | |
2030 | (*packet_size) = 0; |
2031 | ecryptfs_from_hex(dst: key_rec->sig, src: auth_tok->token.private_key.signature, |
2032 | ECRYPTFS_SIG_SIZE); |
2033 | encrypted_session_key_valid = 0; |
2034 | for (i = 0; i < crypt_stat->key_size; i++) |
2035 | encrypted_session_key_valid |= |
2036 | auth_tok->session_key.encrypted_key[i]; |
2037 | if (encrypted_session_key_valid) { |
2038 | memcpy(key_rec->enc_key, |
2039 | auth_tok->session_key.encrypted_key, |
2040 | auth_tok->session_key.encrypted_key_size); |
2041 | up_write(sem: &(auth_tok_key->sem)); |
2042 | key_put(key: auth_tok_key); |
2043 | goto encrypted_session_key_set; |
2044 | } |
2045 | if (auth_tok->session_key.encrypted_key_size == 0) |
2046 | auth_tok->session_key.encrypted_key_size = |
2047 | auth_tok->token.private_key.key_size; |
2048 | rc = pki_encrypt_session_key(auth_tok_key, auth_tok, crypt_stat, |
2049 | key_rec); |
2050 | if (rc) { |
2051 | printk(KERN_ERR "Failed to encrypt session key via a key " |
2052 | "module; rc = [%d]\n" , rc); |
2053 | goto out; |
2054 | } |
2055 | if (ecryptfs_verbosity > 0) { |
2056 | ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n" ); |
2057 | ecryptfs_dump_hex(data: key_rec->enc_key, bytes: key_rec->enc_key_size); |
2058 | } |
2059 | encrypted_session_key_set: |
2060 | /* This format is inspired by OpenPGP; see RFC 2440 |
2061 | * packet tag 1 */ |
2062 | max_packet_size = (1 /* Tag 1 identifier */ |
2063 | + 3 /* Max Tag 1 packet size */ |
2064 | + 1 /* Version */ |
2065 | + ECRYPTFS_SIG_SIZE /* Key identifier */ |
2066 | + 1 /* Cipher identifier */ |
2067 | + key_rec->enc_key_size); /* Encrypted key size */ |
2068 | if (max_packet_size > (*remaining_bytes)) { |
2069 | printk(KERN_ERR "Packet length larger than maximum allowable; " |
2070 | "need up to [%td] bytes, but there are only [%td] " |
2071 | "available\n" , max_packet_size, (*remaining_bytes)); |
2072 | rc = -EINVAL; |
2073 | goto out; |
2074 | } |
2075 | dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE; |
2076 | rc = ecryptfs_write_packet_length(dest: &dest[(*packet_size)], |
2077 | size: (max_packet_size - 4), |
2078 | packet_size_length: &packet_size_length); |
2079 | if (rc) { |
2080 | ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet " |
2081 | "header; cannot generate packet length\n" ); |
2082 | goto out; |
2083 | } |
2084 | (*packet_size) += packet_size_length; |
2085 | dest[(*packet_size)++] = 0x03; /* version 3 */ |
2086 | memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE); |
2087 | (*packet_size) += ECRYPTFS_SIG_SIZE; |
2088 | dest[(*packet_size)++] = RFC2440_CIPHER_RSA; |
2089 | memcpy(&dest[(*packet_size)], key_rec->enc_key, |
2090 | key_rec->enc_key_size); |
2091 | (*packet_size) += key_rec->enc_key_size; |
2092 | out: |
2093 | if (rc) |
2094 | (*packet_size) = 0; |
2095 | else |
2096 | (*remaining_bytes) -= (*packet_size); |
2097 | return rc; |
2098 | } |
2099 | |
2100 | /** |
2101 | * write_tag_11_packet |
2102 | * @dest: Target into which Tag 11 packet is to be written |
2103 | * @remaining_bytes: Maximum packet length |
2104 | * @contents: Byte array of contents to copy in |
2105 | * @contents_length: Number of bytes in contents |
2106 | * @packet_length: Length of the Tag 11 packet written; zero on error |
2107 | * |
2108 | * Returns zero on success; non-zero on error. |
2109 | */ |
2110 | static int |
2111 | write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents, |
2112 | size_t contents_length, size_t *packet_length) |
2113 | { |
2114 | size_t packet_size_length; |
2115 | size_t max_packet_size; |
2116 | int rc = 0; |
2117 | |
2118 | (*packet_length) = 0; |
2119 | /* This format is inspired by OpenPGP; see RFC 2440 |
2120 | * packet tag 11 */ |
2121 | max_packet_size = (1 /* Tag 11 identifier */ |
2122 | + 3 /* Max Tag 11 packet size */ |
2123 | + 1 /* Binary format specifier */ |
2124 | + 1 /* Filename length */ |
2125 | + 8 /* Filename ("_CONSOLE") */ |
2126 | + 4 /* Modification date */ |
2127 | + contents_length); /* Literal data */ |
2128 | if (max_packet_size > (*remaining_bytes)) { |
2129 | printk(KERN_ERR "Packet length larger than maximum allowable; " |
2130 | "need up to [%td] bytes, but there are only [%td] " |
2131 | "available\n" , max_packet_size, (*remaining_bytes)); |
2132 | rc = -EINVAL; |
2133 | goto out; |
2134 | } |
2135 | dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE; |
2136 | rc = ecryptfs_write_packet_length(dest: &dest[(*packet_length)], |
2137 | size: (max_packet_size - 4), |
2138 | packet_size_length: &packet_size_length); |
2139 | if (rc) { |
2140 | printk(KERN_ERR "Error generating tag 11 packet header; cannot " |
2141 | "generate packet length. rc = [%d]\n" , rc); |
2142 | goto out; |
2143 | } |
2144 | (*packet_length) += packet_size_length; |
2145 | dest[(*packet_length)++] = 0x62; /* binary data format specifier */ |
2146 | dest[(*packet_length)++] = 8; |
2147 | memcpy(&dest[(*packet_length)], "_CONSOLE" , 8); |
2148 | (*packet_length) += 8; |
2149 | memset(&dest[(*packet_length)], 0x00, 4); |
2150 | (*packet_length) += 4; |
2151 | memcpy(&dest[(*packet_length)], contents, contents_length); |
2152 | (*packet_length) += contents_length; |
2153 | out: |
2154 | if (rc) |
2155 | (*packet_length) = 0; |
2156 | else |
2157 | (*remaining_bytes) -= (*packet_length); |
2158 | return rc; |
2159 | } |
2160 | |
2161 | /** |
2162 | * write_tag_3_packet |
2163 | * @dest: Buffer into which to write the packet |
2164 | * @remaining_bytes: Maximum number of bytes that can be written |
2165 | * @auth_tok: Authentication token |
2166 | * @crypt_stat: The cryptographic context |
2167 | * @key_rec: encrypted key |
2168 | * @packet_size: This function will write the number of bytes that end |
2169 | * up constituting the packet; set to zero on error |
2170 | * |
2171 | * Returns zero on success; non-zero on error. |
2172 | */ |
2173 | static int |
2174 | write_tag_3_packet(char *dest, size_t *remaining_bytes, |
2175 | struct ecryptfs_auth_tok *auth_tok, |
2176 | struct ecryptfs_crypt_stat *crypt_stat, |
2177 | struct ecryptfs_key_record *key_rec, size_t *packet_size) |
2178 | { |
2179 | size_t i; |
2180 | size_t encrypted_session_key_valid = 0; |
2181 | char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES]; |
2182 | struct scatterlist dst_sg[2]; |
2183 | struct scatterlist src_sg[2]; |
2184 | struct mutex *tfm_mutex = NULL; |
2185 | u8 cipher_code; |
2186 | size_t packet_size_length; |
2187 | size_t max_packet_size; |
2188 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
2189 | crypt_stat->mount_crypt_stat; |
2190 | struct crypto_skcipher *tfm; |
2191 | struct skcipher_request *req; |
2192 | int rc = 0; |
2193 | |
2194 | (*packet_size) = 0; |
2195 | ecryptfs_from_hex(dst: key_rec->sig, src: auth_tok->token.password.signature, |
2196 | ECRYPTFS_SIG_SIZE); |
2197 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(tfm: &tfm, tfm_mutex: &tfm_mutex, |
2198 | cipher_name: crypt_stat->cipher); |
2199 | if (unlikely(rc)) { |
2200 | printk(KERN_ERR "Internal error whilst attempting to get " |
2201 | "tfm and mutex for cipher name [%s]; rc = [%d]\n" , |
2202 | crypt_stat->cipher, rc); |
2203 | goto out; |
2204 | } |
2205 | if (mount_crypt_stat->global_default_cipher_key_size == 0) { |
2206 | printk(KERN_WARNING "No key size specified at mount; " |
2207 | "defaulting to [%d]\n" , |
2208 | crypto_skcipher_max_keysize(tfm)); |
2209 | mount_crypt_stat->global_default_cipher_key_size = |
2210 | crypto_skcipher_max_keysize(tfm); |
2211 | } |
2212 | if (crypt_stat->key_size == 0) |
2213 | crypt_stat->key_size = |
2214 | mount_crypt_stat->global_default_cipher_key_size; |
2215 | if (auth_tok->session_key.encrypted_key_size == 0) |
2216 | auth_tok->session_key.encrypted_key_size = |
2217 | crypt_stat->key_size; |
2218 | if (crypt_stat->key_size == 24 |
2219 | && strcmp("aes" , crypt_stat->cipher) == 0) { |
2220 | memset((crypt_stat->key + 24), 0, 8); |
2221 | auth_tok->session_key.encrypted_key_size = 32; |
2222 | } else |
2223 | auth_tok->session_key.encrypted_key_size = crypt_stat->key_size; |
2224 | key_rec->enc_key_size = |
2225 | auth_tok->session_key.encrypted_key_size; |
2226 | encrypted_session_key_valid = 0; |
2227 | for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++) |
2228 | encrypted_session_key_valid |= |
2229 | auth_tok->session_key.encrypted_key[i]; |
2230 | if (encrypted_session_key_valid) { |
2231 | ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; " |
2232 | "using auth_tok->session_key.encrypted_key, " |
2233 | "where key_rec->enc_key_size = [%zd]\n" , |
2234 | key_rec->enc_key_size); |
2235 | memcpy(key_rec->enc_key, |
2236 | auth_tok->session_key.encrypted_key, |
2237 | key_rec->enc_key_size); |
2238 | goto encrypted_session_key_set; |
2239 | } |
2240 | if (auth_tok->token.password.flags & |
2241 | ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) { |
2242 | ecryptfs_printk(KERN_DEBUG, "Using previously generated " |
2243 | "session key encryption key of size [%d]\n" , |
2244 | auth_tok->token.password. |
2245 | session_key_encryption_key_bytes); |
2246 | memcpy(session_key_encryption_key, |
2247 | auth_tok->token.password.session_key_encryption_key, |
2248 | crypt_stat->key_size); |
2249 | ecryptfs_printk(KERN_DEBUG, |
2250 | "Cached session key encryption key:\n" ); |
2251 | if (ecryptfs_verbosity > 0) |
2252 | ecryptfs_dump_hex(data: session_key_encryption_key, bytes: 16); |
2253 | } |
2254 | if (unlikely(ecryptfs_verbosity > 0)) { |
2255 | ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n" ); |
2256 | ecryptfs_dump_hex(data: session_key_encryption_key, bytes: 16); |
2257 | } |
2258 | rc = virt_to_scatterlist(addr: crypt_stat->key, size: key_rec->enc_key_size, |
2259 | sg: src_sg, sg_size: 2); |
2260 | if (rc < 1 || rc > 2) { |
2261 | ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
2262 | "for crypt_stat session key; expected rc = 1; " |
2263 | "got rc = [%d]. key_rec->enc_key_size = [%zd]\n" , |
2264 | rc, key_rec->enc_key_size); |
2265 | rc = -ENOMEM; |
2266 | goto out; |
2267 | } |
2268 | rc = virt_to_scatterlist(addr: key_rec->enc_key, size: key_rec->enc_key_size, |
2269 | sg: dst_sg, sg_size: 2); |
2270 | if (rc < 1 || rc > 2) { |
2271 | ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
2272 | "for crypt_stat encrypted session key; " |
2273 | "expected rc = 1; got rc = [%d]. " |
2274 | "key_rec->enc_key_size = [%zd]\n" , rc, |
2275 | key_rec->enc_key_size); |
2276 | rc = -ENOMEM; |
2277 | goto out; |
2278 | } |
2279 | mutex_lock(tfm_mutex); |
2280 | rc = crypto_skcipher_setkey(tfm, key: session_key_encryption_key, |
2281 | keylen: crypt_stat->key_size); |
2282 | if (rc < 0) { |
2283 | mutex_unlock(lock: tfm_mutex); |
2284 | ecryptfs_printk(KERN_ERR, "Error setting key for crypto " |
2285 | "context; rc = [%d]\n" , rc); |
2286 | goto out; |
2287 | } |
2288 | |
2289 | req = skcipher_request_alloc(tfm, GFP_KERNEL); |
2290 | if (!req) { |
2291 | mutex_unlock(lock: tfm_mutex); |
2292 | ecryptfs_printk(KERN_ERR, "Out of kernel memory whilst " |
2293 | "attempting to skcipher_request_alloc for " |
2294 | "%s\n" , crypto_skcipher_driver_name(tfm)); |
2295 | rc = -ENOMEM; |
2296 | goto out; |
2297 | } |
2298 | |
2299 | skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, |
2300 | NULL, NULL); |
2301 | |
2302 | rc = 0; |
2303 | ecryptfs_printk(KERN_DEBUG, "Encrypting [%zd] bytes of the key\n" , |
2304 | crypt_stat->key_size); |
2305 | skcipher_request_set_crypt(req, src: src_sg, dst: dst_sg, |
2306 | cryptlen: (*key_rec).enc_key_size, NULL); |
2307 | rc = crypto_skcipher_encrypt(req); |
2308 | mutex_unlock(lock: tfm_mutex); |
2309 | skcipher_request_free(req); |
2310 | if (rc) { |
2311 | printk(KERN_ERR "Error encrypting; rc = [%d]\n" , rc); |
2312 | goto out; |
2313 | } |
2314 | ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n" ); |
2315 | if (ecryptfs_verbosity > 0) { |
2316 | ecryptfs_printk(KERN_DEBUG, "EFEK of size [%zd]:\n" , |
2317 | key_rec->enc_key_size); |
2318 | ecryptfs_dump_hex(data: key_rec->enc_key, |
2319 | bytes: key_rec->enc_key_size); |
2320 | } |
2321 | encrypted_session_key_set: |
2322 | /* This format is inspired by OpenPGP; see RFC 2440 |
2323 | * packet tag 3 */ |
2324 | max_packet_size = (1 /* Tag 3 identifier */ |
2325 | + 3 /* Max Tag 3 packet size */ |
2326 | + 1 /* Version */ |
2327 | + 1 /* Cipher code */ |
2328 | + 1 /* S2K specifier */ |
2329 | + 1 /* Hash identifier */ |
2330 | + ECRYPTFS_SALT_SIZE /* Salt */ |
2331 | + 1 /* Hash iterations */ |
2332 | + key_rec->enc_key_size); /* Encrypted key size */ |
2333 | if (max_packet_size > (*remaining_bytes)) { |
2334 | printk(KERN_ERR "Packet too large; need up to [%td] bytes, but " |
2335 | "there are only [%td] available\n" , max_packet_size, |
2336 | (*remaining_bytes)); |
2337 | rc = -EINVAL; |
2338 | goto out; |
2339 | } |
2340 | dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE; |
2341 | /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3) |
2342 | * to get the number of octets in the actual Tag 3 packet */ |
2343 | rc = ecryptfs_write_packet_length(dest: &dest[(*packet_size)], |
2344 | size: (max_packet_size - 4), |
2345 | packet_size_length: &packet_size_length); |
2346 | if (rc) { |
2347 | printk(KERN_ERR "Error generating tag 3 packet header; cannot " |
2348 | "generate packet length. rc = [%d]\n" , rc); |
2349 | goto out; |
2350 | } |
2351 | (*packet_size) += packet_size_length; |
2352 | dest[(*packet_size)++] = 0x04; /* version 4 */ |
2353 | /* TODO: Break from RFC2440 so that arbitrary ciphers can be |
2354 | * specified with strings */ |
2355 | cipher_code = ecryptfs_code_for_cipher_string(cipher_name: crypt_stat->cipher, |
2356 | key_bytes: crypt_stat->key_size); |
2357 | if (cipher_code == 0) { |
2358 | ecryptfs_printk(KERN_WARNING, "Unable to generate code for " |
2359 | "cipher [%s]\n" , crypt_stat->cipher); |
2360 | rc = -EINVAL; |
2361 | goto out; |
2362 | } |
2363 | dest[(*packet_size)++] = cipher_code; |
2364 | dest[(*packet_size)++] = 0x03; /* S2K */ |
2365 | dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */ |
2366 | memcpy(&dest[(*packet_size)], auth_tok->token.password.salt, |
2367 | ECRYPTFS_SALT_SIZE); |
2368 | (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */ |
2369 | dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */ |
2370 | memcpy(&dest[(*packet_size)], key_rec->enc_key, |
2371 | key_rec->enc_key_size); |
2372 | (*packet_size) += key_rec->enc_key_size; |
2373 | out: |
2374 | if (rc) |
2375 | (*packet_size) = 0; |
2376 | else |
2377 | (*remaining_bytes) -= (*packet_size); |
2378 | return rc; |
2379 | } |
2380 | |
2381 | struct kmem_cache *ecryptfs_key_record_cache; |
2382 | |
2383 | /** |
2384 | * ecryptfs_generate_key_packet_set |
2385 | * @dest_base: Virtual address from which to write the key record set |
2386 | * @crypt_stat: The cryptographic context from which the |
2387 | * authentication tokens will be retrieved |
2388 | * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat |
2389 | * for the global parameters |
2390 | * @len: The amount written |
2391 | * @max: The maximum amount of data allowed to be written |
2392 | * |
2393 | * Generates a key packet set and writes it to the virtual address |
2394 | * passed in. |
2395 | * |
2396 | * Returns zero on success; non-zero on error. |
2397 | */ |
2398 | int |
2399 | ecryptfs_generate_key_packet_set(char *dest_base, |
2400 | struct ecryptfs_crypt_stat *crypt_stat, |
2401 | struct dentry *ecryptfs_dentry, size_t *len, |
2402 | size_t max) |
2403 | { |
2404 | struct ecryptfs_auth_tok *auth_tok; |
2405 | struct key *auth_tok_key = NULL; |
2406 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
2407 | &ecryptfs_superblock_to_private( |
2408 | sb: ecryptfs_dentry->d_sb)->mount_crypt_stat; |
2409 | size_t written; |
2410 | struct ecryptfs_key_record *key_rec; |
2411 | struct ecryptfs_key_sig *key_sig; |
2412 | int rc = 0; |
2413 | |
2414 | (*len) = 0; |
2415 | mutex_lock(&crypt_stat->keysig_list_mutex); |
2416 | key_rec = kmem_cache_alloc(cachep: ecryptfs_key_record_cache, GFP_KERNEL); |
2417 | if (!key_rec) { |
2418 | rc = -ENOMEM; |
2419 | goto out; |
2420 | } |
2421 | list_for_each_entry(key_sig, &crypt_stat->keysig_list, |
2422 | crypt_stat_list) { |
2423 | memset(key_rec, 0, sizeof(*key_rec)); |
2424 | rc = ecryptfs_find_global_auth_tok_for_sig(auth_tok_key: &auth_tok_key, |
2425 | auth_tok: &auth_tok, |
2426 | mount_crypt_stat, |
2427 | sig: key_sig->keysig); |
2428 | if (rc) { |
2429 | printk(KERN_WARNING "Unable to retrieve auth tok with " |
2430 | "sig = [%s]\n" , key_sig->keysig); |
2431 | rc = process_find_global_auth_tok_for_sig_err(err_code: rc); |
2432 | goto out_free; |
2433 | } |
2434 | if (auth_tok->token_type == ECRYPTFS_PASSWORD) { |
2435 | rc = write_tag_3_packet(dest: (dest_base + (*len)), |
2436 | remaining_bytes: &max, auth_tok, |
2437 | crypt_stat, key_rec, |
2438 | packet_size: &written); |
2439 | up_write(sem: &(auth_tok_key->sem)); |
2440 | key_put(key: auth_tok_key); |
2441 | if (rc) { |
2442 | ecryptfs_printk(KERN_WARNING, "Error " |
2443 | "writing tag 3 packet\n" ); |
2444 | goto out_free; |
2445 | } |
2446 | (*len) += written; |
2447 | /* Write auth tok signature packet */ |
2448 | rc = write_tag_11_packet(dest: (dest_base + (*len)), remaining_bytes: &max, |
2449 | contents: key_rec->sig, |
2450 | ECRYPTFS_SIG_SIZE, packet_length: &written); |
2451 | if (rc) { |
2452 | ecryptfs_printk(KERN_ERR, "Error writing " |
2453 | "auth tok signature packet\n" ); |
2454 | goto out_free; |
2455 | } |
2456 | (*len) += written; |
2457 | } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
2458 | rc = write_tag_1_packet(dest: dest_base + (*len), remaining_bytes: &max, |
2459 | auth_tok_key, auth_tok, |
2460 | crypt_stat, key_rec, packet_size: &written); |
2461 | if (rc) { |
2462 | ecryptfs_printk(KERN_WARNING, "Error " |
2463 | "writing tag 1 packet\n" ); |
2464 | goto out_free; |
2465 | } |
2466 | (*len) += written; |
2467 | } else { |
2468 | up_write(sem: &(auth_tok_key->sem)); |
2469 | key_put(key: auth_tok_key); |
2470 | ecryptfs_printk(KERN_WARNING, "Unsupported " |
2471 | "authentication token type\n" ); |
2472 | rc = -EINVAL; |
2473 | goto out_free; |
2474 | } |
2475 | } |
2476 | if (likely(max > 0)) { |
2477 | dest_base[(*len)] = 0x00; |
2478 | } else { |
2479 | ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n" ); |
2480 | rc = -EIO; |
2481 | } |
2482 | out_free: |
2483 | kmem_cache_free(s: ecryptfs_key_record_cache, objp: key_rec); |
2484 | out: |
2485 | if (rc) |
2486 | (*len) = 0; |
2487 | mutex_unlock(lock: &crypt_stat->keysig_list_mutex); |
2488 | return rc; |
2489 | } |
2490 | |
2491 | struct kmem_cache *ecryptfs_key_sig_cache; |
2492 | |
2493 | int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig) |
2494 | { |
2495 | struct ecryptfs_key_sig *new_key_sig; |
2496 | |
2497 | new_key_sig = kmem_cache_alloc(cachep: ecryptfs_key_sig_cache, GFP_KERNEL); |
2498 | if (!new_key_sig) |
2499 | return -ENOMEM; |
2500 | |
2501 | memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX); |
2502 | new_key_sig->keysig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
2503 | /* Caller must hold keysig_list_mutex */ |
2504 | list_add(new: &new_key_sig->crypt_stat_list, head: &crypt_stat->keysig_list); |
2505 | |
2506 | return 0; |
2507 | } |
2508 | |
2509 | struct kmem_cache *ecryptfs_global_auth_tok_cache; |
2510 | |
2511 | int |
2512 | ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, |
2513 | char *sig, u32 global_auth_tok_flags) |
2514 | { |
2515 | struct ecryptfs_global_auth_tok *new_auth_tok; |
2516 | |
2517 | new_auth_tok = kmem_cache_zalloc(k: ecryptfs_global_auth_tok_cache, |
2518 | GFP_KERNEL); |
2519 | if (!new_auth_tok) |
2520 | return -ENOMEM; |
2521 | |
2522 | memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX); |
2523 | new_auth_tok->flags = global_auth_tok_flags; |
2524 | new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
2525 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); |
2526 | list_add(new: &new_auth_tok->mount_crypt_stat_list, |
2527 | head: &mount_crypt_stat->global_auth_tok_list); |
2528 | mutex_unlock(lock: &mount_crypt_stat->global_auth_tok_list_mutex); |
2529 | return 0; |
2530 | } |
2531 | |
2532 | |