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Commit | Line | Data |
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237fead6 MH |
1 | /** |
2 | * eCryptfs: Linux filesystem encryption layer | |
3 | * In-kernel key management code. Includes functions to parse and | |
4 | * write authentication token-related packets with the underlying | |
5 | * file. | |
6 | * | |
7 | * Copyright (C) 2004-2006 International Business Machines Corp. | |
8 | * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com> | |
9 | * Michael C. Thompson <mcthomps@us.ibm.com> | |
dddfa461 | 10 | * Trevor S. Highland <trevor.highland@gmail.com> |
237fead6 MH |
11 | * |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU General Public License as | |
14 | * published by the Free Software Foundation; either version 2 of the | |
15 | * License, or (at your option) any later version. | |
16 | * | |
17 | * This program is distributed in the hope that it will be useful, but | |
18 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
20 | * General Public License for more details. | |
21 | * | |
22 | * You should have received a copy of the GNU General Public License | |
23 | * along with this program; if not, write to the Free Software | |
24 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
25 | * 02111-1307, USA. | |
26 | */ | |
27 | ||
28 | #include <linux/string.h> | |
237fead6 MH |
29 | #include <linux/syscalls.h> |
30 | #include <linux/pagemap.h> | |
31 | #include <linux/key.h> | |
32 | #include <linux/random.h> | |
33 | #include <linux/crypto.h> | |
34 | #include <linux/scatterlist.h> | |
5a0e3ad6 | 35 | #include <linux/slab.h> |
237fead6 MH |
36 | #include "ecryptfs_kernel.h" |
37 | ||
38 | /** | |
39 | * request_key returned an error instead of a valid key address; | |
40 | * determine the type of error, make appropriate log entries, and | |
41 | * return an error code. | |
42 | */ | |
cd9d67df | 43 | static int process_request_key_err(long err_code) |
237fead6 MH |
44 | { |
45 | int rc = 0; | |
46 | ||
47 | switch (err_code) { | |
982363c9 | 48 | case -ENOKEY: |
237fead6 MH |
49 | ecryptfs_printk(KERN_WARNING, "No key\n"); |
50 | rc = -ENOENT; | |
51 | break; | |
982363c9 | 52 | case -EKEYEXPIRED: |
237fead6 MH |
53 | ecryptfs_printk(KERN_WARNING, "Key expired\n"); |
54 | rc = -ETIME; | |
55 | break; | |
982363c9 | 56 | case -EKEYREVOKED: |
237fead6 MH |
57 | ecryptfs_printk(KERN_WARNING, "Key revoked\n"); |
58 | rc = -EINVAL; | |
59 | break; | |
60 | default: | |
61 | ecryptfs_printk(KERN_WARNING, "Unknown error code: " | |
888d57bb | 62 | "[0x%.16lx]\n", err_code); |
237fead6 MH |
63 | rc = -EINVAL; |
64 | } | |
65 | return rc; | |
66 | } | |
67 | ||
0e1fc5ef RS |
68 | static int process_find_global_auth_tok_for_sig_err(int err_code) |
69 | { | |
70 | int rc = err_code; | |
71 | ||
72 | switch (err_code) { | |
73 | case -ENOENT: | |
74 | ecryptfs_printk(KERN_WARNING, "Missing auth tok\n"); | |
75 | break; | |
76 | case -EINVAL: | |
77 | ecryptfs_printk(KERN_WARNING, "Invalid auth tok\n"); | |
78 | break; | |
79 | default: | |
80 | rc = process_request_key_err(err_code); | |
81 | break; | |
82 | } | |
83 | return rc; | |
84 | } | |
85 | ||
237fead6 | 86 | /** |
f66e883e | 87 | * ecryptfs_parse_packet_length |
237fead6 MH |
88 | * @data: Pointer to memory containing length at offset |
89 | * @size: This function writes the decoded size to this memory | |
90 | * address; zero on error | |
91 | * @length_size: The number of bytes occupied by the encoded length | |
92 | * | |
22e78faf | 93 | * Returns zero on success; non-zero on error |
237fead6 | 94 | */ |
f66e883e MH |
95 | int ecryptfs_parse_packet_length(unsigned char *data, size_t *size, |
96 | size_t *length_size) | |
237fead6 MH |
97 | { |
98 | int rc = 0; | |
99 | ||
100 | (*length_size) = 0; | |
101 | (*size) = 0; | |
102 | if (data[0] < 192) { | |
103 | /* One-byte length */ | |
dddfa461 | 104 | (*size) = (unsigned char)data[0]; |
237fead6 MH |
105 | (*length_size) = 1; |
106 | } else if (data[0] < 224) { | |
107 | /* Two-byte length */ | |
dddfa461 MH |
108 | (*size) = (((unsigned char)(data[0]) - 192) * 256); |
109 | (*size) += ((unsigned char)(data[1]) + 192); | |
237fead6 MH |
110 | (*length_size) = 2; |
111 | } else if (data[0] == 255) { | |
112 | /* Five-byte length; we're not supposed to see this */ | |
113 | ecryptfs_printk(KERN_ERR, "Five-byte packet length not " | |
114 | "supported\n"); | |
115 | rc = -EINVAL; | |
116 | goto out; | |
117 | } else { | |
118 | ecryptfs_printk(KERN_ERR, "Error parsing packet length\n"); | |
119 | rc = -EINVAL; | |
120 | goto out; | |
121 | } | |
122 | out: | |
123 | return rc; | |
124 | } | |
125 | ||
126 | /** | |
f66e883e | 127 | * ecryptfs_write_packet_length |
22e78faf MH |
128 | * @dest: The byte array target into which to write the length. Must |
129 | * have at least 5 bytes allocated. | |
237fead6 | 130 | * @size: The length to write. |
22e78faf MH |
131 | * @packet_size_length: The number of bytes used to encode the packet |
132 | * length is written to this address. | |
237fead6 MH |
133 | * |
134 | * Returns zero on success; non-zero on error. | |
135 | */ | |
f66e883e MH |
136 | int ecryptfs_write_packet_length(char *dest, size_t size, |
137 | size_t *packet_size_length) | |
237fead6 MH |
138 | { |
139 | int rc = 0; | |
140 | ||
141 | if (size < 192) { | |
142 | dest[0] = size; | |
143 | (*packet_size_length) = 1; | |
144 | } else if (size < 65536) { | |
145 | dest[0] = (((size - 192) / 256) + 192); | |
146 | dest[1] = ((size - 192) % 256); | |
147 | (*packet_size_length) = 2; | |
148 | } else { | |
149 | rc = -EINVAL; | |
150 | ecryptfs_printk(KERN_WARNING, | |
f24b3887 | 151 | "Unsupported packet size: [%zd]\n", size); |
237fead6 MH |
152 | } |
153 | return rc; | |
154 | } | |
155 | ||
dddfa461 MH |
156 | static int |
157 | write_tag_64_packet(char *signature, struct ecryptfs_session_key *session_key, | |
158 | char **packet, size_t *packet_len) | |
159 | { | |
160 | size_t i = 0; | |
161 | size_t data_len; | |
162 | size_t packet_size_len; | |
163 | char *message; | |
164 | int rc; | |
165 | ||
166 | /* | |
167 | * ***** TAG 64 Packet Format ***** | |
168 | * | Content Type | 1 byte | | |
169 | * | Key Identifier Size | 1 or 2 bytes | | |
170 | * | Key Identifier | arbitrary | | |
171 | * | Encrypted File Encryption Key Size | 1 or 2 bytes | | |
172 | * | Encrypted File Encryption Key | arbitrary | | |
173 | */ | |
174 | data_len = (5 + ECRYPTFS_SIG_SIZE_HEX | |
175 | + session_key->encrypted_key_size); | |
176 | *packet = kmalloc(data_len, GFP_KERNEL); | |
177 | message = *packet; | |
178 | if (!message) { | |
179 | ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n"); | |
180 | rc = -ENOMEM; | |
181 | goto out; | |
182 | } | |
183 | message[i++] = ECRYPTFS_TAG_64_PACKET_TYPE; | |
f66e883e MH |
184 | rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX, |
185 | &packet_size_len); | |
dddfa461 MH |
186 | if (rc) { |
187 | ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet " | |
188 | "header; cannot generate packet length\n"); | |
189 | goto out; | |
190 | } | |
191 | i += packet_size_len; | |
192 | memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX); | |
193 | i += ECRYPTFS_SIG_SIZE_HEX; | |
f66e883e MH |
194 | rc = ecryptfs_write_packet_length(&message[i], |
195 | session_key->encrypted_key_size, | |
196 | &packet_size_len); | |
dddfa461 MH |
197 | if (rc) { |
198 | ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet " | |
199 | "header; cannot generate packet length\n"); | |
200 | goto out; | |
201 | } | |
202 | i += packet_size_len; | |
203 | memcpy(&message[i], session_key->encrypted_key, | |
204 | session_key->encrypted_key_size); | |
205 | i += session_key->encrypted_key_size; | |
206 | *packet_len = i; | |
207 | out: | |
208 | return rc; | |
209 | } | |
210 | ||
211 | static int | |
19e66a67 | 212 | parse_tag_65_packet(struct ecryptfs_session_key *session_key, u8 *cipher_code, |
dddfa461 MH |
213 | struct ecryptfs_message *msg) |
214 | { | |
215 | size_t i = 0; | |
216 | char *data; | |
217 | size_t data_len; | |
218 | size_t m_size; | |
219 | size_t message_len; | |
220 | u16 checksum = 0; | |
221 | u16 expected_checksum = 0; | |
222 | int rc; | |
223 | ||
224 | /* | |
225 | * ***** TAG 65 Packet Format ***** | |
226 | * | Content Type | 1 byte | | |
227 | * | Status Indicator | 1 byte | | |
228 | * | File Encryption Key Size | 1 or 2 bytes | | |
229 | * | File Encryption Key | arbitrary | | |
230 | */ | |
231 | message_len = msg->data_len; | |
232 | data = msg->data; | |
233 | if (message_len < 4) { | |
234 | rc = -EIO; | |
235 | goto out; | |
236 | } | |
237 | if (data[i++] != ECRYPTFS_TAG_65_PACKET_TYPE) { | |
238 | ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_65\n"); | |
239 | rc = -EIO; | |
240 | goto out; | |
241 | } | |
242 | if (data[i++]) { | |
243 | ecryptfs_printk(KERN_ERR, "Status indicator has non-zero value " | |
244 | "[%d]\n", data[i-1]); | |
245 | rc = -EIO; | |
246 | goto out; | |
247 | } | |
f66e883e | 248 | rc = ecryptfs_parse_packet_length(&data[i], &m_size, &data_len); |
dddfa461 MH |
249 | if (rc) { |
250 | ecryptfs_printk(KERN_WARNING, "Error parsing packet length; " | |
251 | "rc = [%d]\n", rc); | |
252 | goto out; | |
253 | } | |
254 | i += data_len; | |
255 | if (message_len < (i + m_size)) { | |
624ae528 TH |
256 | ecryptfs_printk(KERN_ERR, "The message received from ecryptfsd " |
257 | "is shorter than expected\n"); | |
dddfa461 MH |
258 | rc = -EIO; |
259 | goto out; | |
260 | } | |
261 | if (m_size < 3) { | |
262 | ecryptfs_printk(KERN_ERR, | |
263 | "The decrypted key is not long enough to " | |
264 | "include a cipher code and checksum\n"); | |
265 | rc = -EIO; | |
266 | goto out; | |
267 | } | |
268 | *cipher_code = data[i++]; | |
269 | /* The decrypted key includes 1 byte cipher code and 2 byte checksum */ | |
270 | session_key->decrypted_key_size = m_size - 3; | |
271 | if (session_key->decrypted_key_size > ECRYPTFS_MAX_KEY_BYTES) { | |
272 | ecryptfs_printk(KERN_ERR, "key_size [%d] larger than " | |
273 | "the maximum key size [%d]\n", | |
274 | session_key->decrypted_key_size, | |
275 | ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES); | |
276 | rc = -EIO; | |
277 | goto out; | |
278 | } | |
279 | memcpy(session_key->decrypted_key, &data[i], | |
280 | session_key->decrypted_key_size); | |
281 | i += session_key->decrypted_key_size; | |
282 | expected_checksum += (unsigned char)(data[i++]) << 8; | |
283 | expected_checksum += (unsigned char)(data[i++]); | |
284 | for (i = 0; i < session_key->decrypted_key_size; i++) | |
285 | checksum += session_key->decrypted_key[i]; | |
286 | if (expected_checksum != checksum) { | |
287 | ecryptfs_printk(KERN_ERR, "Invalid checksum for file " | |
288 | "encryption key; expected [%x]; calculated " | |
289 | "[%x]\n", expected_checksum, checksum); | |
290 | rc = -EIO; | |
291 | } | |
292 | out: | |
293 | return rc; | |
294 | } | |
295 | ||
296 | ||
297 | static int | |
19e66a67 | 298 | write_tag_66_packet(char *signature, u8 cipher_code, |
dddfa461 MH |
299 | struct ecryptfs_crypt_stat *crypt_stat, char **packet, |
300 | size_t *packet_len) | |
301 | { | |
302 | size_t i = 0; | |
303 | size_t j; | |
304 | size_t data_len; | |
305 | size_t checksum = 0; | |
306 | size_t packet_size_len; | |
307 | char *message; | |
308 | int rc; | |
309 | ||
310 | /* | |
311 | * ***** TAG 66 Packet Format ***** | |
312 | * | Content Type | 1 byte | | |
313 | * | Key Identifier Size | 1 or 2 bytes | | |
314 | * | Key Identifier | arbitrary | | |
315 | * | File Encryption Key Size | 1 or 2 bytes | | |
316 | * | File Encryption Key | arbitrary | | |
317 | */ | |
318 | data_len = (5 + ECRYPTFS_SIG_SIZE_HEX + crypt_stat->key_size); | |
319 | *packet = kmalloc(data_len, GFP_KERNEL); | |
320 | message = *packet; | |
321 | if (!message) { | |
322 | ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n"); | |
323 | rc = -ENOMEM; | |
324 | goto out; | |
325 | } | |
326 | message[i++] = ECRYPTFS_TAG_66_PACKET_TYPE; | |
f66e883e MH |
327 | rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX, |
328 | &packet_size_len); | |
dddfa461 MH |
329 | if (rc) { |
330 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet " | |
331 | "header; cannot generate packet length\n"); | |
332 | goto out; | |
333 | } | |
334 | i += packet_size_len; | |
335 | memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX); | |
336 | i += ECRYPTFS_SIG_SIZE_HEX; | |
337 | /* The encrypted key includes 1 byte cipher code and 2 byte checksum */ | |
f66e883e MH |
338 | rc = ecryptfs_write_packet_length(&message[i], crypt_stat->key_size + 3, |
339 | &packet_size_len); | |
dddfa461 MH |
340 | if (rc) { |
341 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet " | |
342 | "header; cannot generate packet length\n"); | |
343 | goto out; | |
344 | } | |
345 | i += packet_size_len; | |
346 | message[i++] = cipher_code; | |
347 | memcpy(&message[i], crypt_stat->key, crypt_stat->key_size); | |
348 | i += crypt_stat->key_size; | |
349 | for (j = 0; j < crypt_stat->key_size; j++) | |
350 | checksum += crypt_stat->key[j]; | |
351 | message[i++] = (checksum / 256) % 256; | |
352 | message[i++] = (checksum % 256); | |
353 | *packet_len = i; | |
354 | out: | |
355 | return rc; | |
356 | } | |
357 | ||
358 | static int | |
359 | parse_tag_67_packet(struct ecryptfs_key_record *key_rec, | |
360 | struct ecryptfs_message *msg) | |
361 | { | |
362 | size_t i = 0; | |
363 | char *data; | |
364 | size_t data_len; | |
365 | size_t message_len; | |
366 | int rc; | |
367 | ||
368 | /* | |
369 | * ***** TAG 65 Packet Format ***** | |
370 | * | Content Type | 1 byte | | |
371 | * | Status Indicator | 1 byte | | |
372 | * | Encrypted File Encryption Key Size | 1 or 2 bytes | | |
373 | * | Encrypted File Encryption Key | arbitrary | | |
374 | */ | |
375 | message_len = msg->data_len; | |
376 | data = msg->data; | |
377 | /* verify that everything through the encrypted FEK size is present */ | |
378 | if (message_len < 4) { | |
379 | rc = -EIO; | |
df261c52 | 380 | printk(KERN_ERR "%s: message_len is [%zd]; minimum acceptable " |
f66e883e | 381 | "message length is [%d]\n", __func__, message_len, 4); |
dddfa461 MH |
382 | goto out; |
383 | } | |
384 | if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) { | |
dddfa461 | 385 | rc = -EIO; |
f66e883e MH |
386 | printk(KERN_ERR "%s: Type should be ECRYPTFS_TAG_67\n", |
387 | __func__); | |
dddfa461 MH |
388 | goto out; |
389 | } | |
390 | if (data[i++]) { | |
dddfa461 | 391 | rc = -EIO; |
f66e883e MH |
392 | printk(KERN_ERR "%s: Status indicator has non zero " |
393 | "value [%d]\n", __func__, data[i-1]); | |
394 | ||
dddfa461 MH |
395 | goto out; |
396 | } | |
f66e883e MH |
397 | rc = ecryptfs_parse_packet_length(&data[i], &key_rec->enc_key_size, |
398 | &data_len); | |
dddfa461 MH |
399 | if (rc) { |
400 | ecryptfs_printk(KERN_WARNING, "Error parsing packet length; " | |
401 | "rc = [%d]\n", rc); | |
402 | goto out; | |
403 | } | |
404 | i += data_len; | |
405 | if (message_len < (i + key_rec->enc_key_size)) { | |
dddfa461 | 406 | rc = -EIO; |
df261c52 | 407 | printk(KERN_ERR "%s: message_len [%zd]; max len is [%zd]\n", |
f66e883e | 408 | __func__, message_len, (i + key_rec->enc_key_size)); |
dddfa461 MH |
409 | goto out; |
410 | } | |
411 | if (key_rec->enc_key_size > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
dddfa461 | 412 | rc = -EIO; |
df261c52 | 413 | printk(KERN_ERR "%s: Encrypted key_size [%zd] larger than " |
f66e883e MH |
414 | "the maximum key size [%d]\n", __func__, |
415 | key_rec->enc_key_size, | |
416 | ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES); | |
dddfa461 MH |
417 | goto out; |
418 | } | |
419 | memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size); | |
420 | out: | |
421 | return rc; | |
422 | } | |
423 | ||
0e1fc5ef RS |
424 | /** |
425 | * ecryptfs_verify_version | |
426 | * @version: The version number to confirm | |
427 | * | |
428 | * Returns zero on good version; non-zero otherwise | |
429 | */ | |
430 | static int ecryptfs_verify_version(u16 version) | |
431 | { | |
432 | int rc = 0; | |
433 | unsigned char major; | |
434 | unsigned char minor; | |
435 | ||
436 | major = ((version >> 8) & 0xFF); | |
437 | minor = (version & 0xFF); | |
438 | if (major != ECRYPTFS_VERSION_MAJOR) { | |
439 | ecryptfs_printk(KERN_ERR, "Major version number mismatch. " | |
440 | "Expected [%d]; got [%d]\n", | |
441 | ECRYPTFS_VERSION_MAJOR, major); | |
442 | rc = -EINVAL; | |
443 | goto out; | |
444 | } | |
445 | if (minor != ECRYPTFS_VERSION_MINOR) { | |
446 | ecryptfs_printk(KERN_ERR, "Minor version number mismatch. " | |
447 | "Expected [%d]; got [%d]\n", | |
448 | ECRYPTFS_VERSION_MINOR, minor); | |
449 | rc = -EINVAL; | |
450 | goto out; | |
451 | } | |
452 | out: | |
453 | return rc; | |
454 | } | |
455 | ||
456 | /** | |
457 | * ecryptfs_verify_auth_tok_from_key | |
458 | * @auth_tok_key: key containing the authentication token | |
459 | * @auth_tok: authentication token | |
460 | * | |
461 | * Returns zero on valid auth tok; -EINVAL otherwise | |
462 | */ | |
463 | static int | |
464 | ecryptfs_verify_auth_tok_from_key(struct key *auth_tok_key, | |
465 | struct ecryptfs_auth_tok **auth_tok) | |
466 | { | |
467 | int rc = 0; | |
468 | ||
469 | (*auth_tok) = ecryptfs_get_key_payload_data(auth_tok_key); | |
470 | if (ecryptfs_verify_version((*auth_tok)->version)) { | |
471 | printk(KERN_ERR "Data structure version mismatch. Userspace " | |
472 | "tools must match eCryptfs kernel module with major " | |
473 | "version [%d] and minor version [%d]\n", | |
474 | ECRYPTFS_VERSION_MAJOR, ECRYPTFS_VERSION_MINOR); | |
475 | rc = -EINVAL; | |
476 | goto out; | |
477 | } | |
478 | if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD | |
479 | && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) { | |
480 | printk(KERN_ERR "Invalid auth_tok structure " | |
481 | "returned from key query\n"); | |
482 | rc = -EINVAL; | |
483 | goto out; | |
484 | } | |
485 | out: | |
486 | return rc; | |
487 | } | |
488 | ||
9c79f34f MH |
489 | static int |
490 | ecryptfs_find_global_auth_tok_for_sig( | |
0e1fc5ef RS |
491 | struct key **auth_tok_key, |
492 | struct ecryptfs_auth_tok **auth_tok, | |
9c79f34f MH |
493 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig) |
494 | { | |
495 | struct ecryptfs_global_auth_tok *walker; | |
496 | int rc = 0; | |
497 | ||
0e1fc5ef RS |
498 | (*auth_tok_key) = NULL; |
499 | (*auth_tok) = NULL; | |
9c79f34f MH |
500 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); |
501 | list_for_each_entry(walker, | |
502 | &mount_crypt_stat->global_auth_tok_list, | |
503 | mount_crypt_stat_list) { | |
0e1fc5ef RS |
504 | if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX)) |
505 | continue; | |
506 | ||
507 | if (walker->flags & ECRYPTFS_AUTH_TOK_INVALID) { | |
508 | rc = -EINVAL; | |
9c79f34f MH |
509 | goto out; |
510 | } | |
0e1fc5ef RS |
511 | |
512 | rc = key_validate(walker->global_auth_tok_key); | |
513 | if (rc) { | |
514 | if (rc == -EKEYEXPIRED) | |
515 | goto out; | |
516 | goto out_invalid_auth_tok; | |
517 | } | |
518 | ||
b5695d04 | 519 | down_write(&(walker->global_auth_tok_key->sem)); |
0e1fc5ef RS |
520 | rc = ecryptfs_verify_auth_tok_from_key( |
521 | walker->global_auth_tok_key, auth_tok); | |
522 | if (rc) | |
b5695d04 | 523 | goto out_invalid_auth_tok_unlock; |
0e1fc5ef RS |
524 | |
525 | (*auth_tok_key) = walker->global_auth_tok_key; | |
526 | key_get(*auth_tok_key); | |
527 | goto out; | |
9c79f34f | 528 | } |
0e1fc5ef RS |
529 | rc = -ENOENT; |
530 | goto out; | |
b5695d04 RS |
531 | out_invalid_auth_tok_unlock: |
532 | up_write(&(walker->global_auth_tok_key->sem)); | |
0e1fc5ef RS |
533 | out_invalid_auth_tok: |
534 | printk(KERN_WARNING "Invalidating auth tok with sig = [%s]\n", sig); | |
535 | walker->flags |= ECRYPTFS_AUTH_TOK_INVALID; | |
536 | key_put(walker->global_auth_tok_key); | |
537 | walker->global_auth_tok_key = NULL; | |
9c79f34f MH |
538 | out: |
539 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
540 | return rc; | |
541 | } | |
542 | ||
543 | /** | |
544 | * ecryptfs_find_auth_tok_for_sig | |
545 | * @auth_tok: Set to the matching auth_tok; NULL if not found | |
546 | * @crypt_stat: inode crypt_stat crypto context | |
547 | * @sig: Sig of auth_tok to find | |
548 | * | |
549 | * For now, this function simply looks at the registered auth_tok's | |
550 | * linked off the mount_crypt_stat, so all the auth_toks that can be | |
551 | * used must be registered at mount time. This function could | |
552 | * potentially try a lot harder to find auth_tok's (e.g., by calling | |
553 | * out to ecryptfsd to dynamically retrieve an auth_tok object) so | |
554 | * that static registration of auth_tok's will no longer be necessary. | |
555 | * | |
556 | * Returns zero on no error; non-zero on error | |
557 | */ | |
558 | static int | |
559 | ecryptfs_find_auth_tok_for_sig( | |
aee683b9 | 560 | struct key **auth_tok_key, |
9c79f34f MH |
561 | struct ecryptfs_auth_tok **auth_tok, |
562 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
563 | char *sig) | |
564 | { | |
9c79f34f MH |
565 | int rc = 0; |
566 | ||
0e1fc5ef RS |
567 | rc = ecryptfs_find_global_auth_tok_for_sig(auth_tok_key, auth_tok, |
568 | mount_crypt_stat, sig); | |
569 | if (rc == -ENOENT) { | |
f16feb51 RS |
570 | /* if the flag ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY is set in the |
571 | * mount_crypt_stat structure, we prevent to use auth toks that | |
572 | * are not inserted through the ecryptfs_add_global_auth_tok | |
573 | * function. | |
574 | */ | |
575 | if (mount_crypt_stat->flags | |
576 | & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY) | |
577 | return -EINVAL; | |
578 | ||
aee683b9 | 579 | rc = ecryptfs_keyring_auth_tok_for_sig(auth_tok_key, auth_tok, |
9c79f34f | 580 | sig); |
0e1fc5ef | 581 | } |
9c79f34f MH |
582 | return rc; |
583 | } | |
584 | ||
585 | /** | |
586 | * write_tag_70_packet can gobble a lot of stack space. We stuff most | |
587 | * of the function's parameters in a kmalloc'd struct to help reduce | |
588 | * eCryptfs' overall stack usage. | |
589 | */ | |
590 | struct ecryptfs_write_tag_70_packet_silly_stack { | |
591 | u8 cipher_code; | |
592 | size_t max_packet_size; | |
593 | size_t packet_size_len; | |
594 | size_t block_aligned_filename_size; | |
595 | size_t block_size; | |
596 | size_t i; | |
597 | size_t j; | |
598 | size_t num_rand_bytes; | |
599 | struct mutex *tfm_mutex; | |
600 | char *block_aligned_filename; | |
601 | struct ecryptfs_auth_tok *auth_tok; | |
8d08dab7 TH |
602 | struct scatterlist src_sg[2]; |
603 | struct scatterlist dst_sg[2]; | |
9c79f34f MH |
604 | struct blkcipher_desc desc; |
605 | char iv[ECRYPTFS_MAX_IV_BYTES]; | |
606 | char hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; | |
607 | char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; | |
608 | struct hash_desc hash_desc; | |
609 | struct scatterlist hash_sg; | |
610 | }; | |
611 | ||
612 | /** | |
613 | * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK | |
614 | * @filename: NULL-terminated filename string | |
615 | * | |
616 | * This is the simplest mechanism for achieving filename encryption in | |
617 | * eCryptfs. It encrypts the given filename with the mount-wide | |
618 | * filename encryption key (FNEK) and stores it in a packet to @dest, | |
619 | * which the callee will encode and write directly into the dentry | |
620 | * name. | |
621 | */ | |
622 | int | |
623 | ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, | |
624 | size_t *packet_size, | |
625 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
626 | char *filename, size_t filename_size) | |
627 | { | |
628 | struct ecryptfs_write_tag_70_packet_silly_stack *s; | |
aee683b9 | 629 | struct key *auth_tok_key = NULL; |
9c79f34f MH |
630 | int rc = 0; |
631 | ||
632 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
633 | if (!s) { | |
634 | printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc " | |
df261c52 | 635 | "[%zd] bytes of kernel memory\n", __func__, sizeof(*s)); |
f137f150 | 636 | rc = -ENOMEM; |
9c79f34f MH |
637 | goto out; |
638 | } | |
639 | s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; | |
640 | (*packet_size) = 0; | |
950983fc RS |
641 | rc = ecryptfs_find_auth_tok_for_sig( |
642 | &auth_tok_key, | |
643 | &s->auth_tok, mount_crypt_stat, | |
644 | mount_crypt_stat->global_default_fnek_sig); | |
645 | if (rc) { | |
646 | printk(KERN_ERR "%s: Error attempting to find auth tok for " | |
647 | "fnek sig [%s]; rc = [%d]\n", __func__, | |
648 | mount_crypt_stat->global_default_fnek_sig, rc); | |
649 | goto out; | |
650 | } | |
9c79f34f MH |
651 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name( |
652 | &s->desc.tfm, | |
653 | &s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name); | |
654 | if (unlikely(rc)) { | |
655 | printk(KERN_ERR "Internal error whilst attempting to get " | |
656 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
657 | mount_crypt_stat->global_default_fn_cipher_name, rc); | |
658 | goto out; | |
659 | } | |
660 | mutex_lock(s->tfm_mutex); | |
661 | s->block_size = crypto_blkcipher_blocksize(s->desc.tfm); | |
662 | /* Plus one for the \0 separator between the random prefix | |
663 | * and the plaintext filename */ | |
664 | s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1); | |
665 | s->block_aligned_filename_size = (s->num_rand_bytes + filename_size); | |
666 | if ((s->block_aligned_filename_size % s->block_size) != 0) { | |
667 | s->num_rand_bytes += (s->block_size | |
668 | - (s->block_aligned_filename_size | |
669 | % s->block_size)); | |
670 | s->block_aligned_filename_size = (s->num_rand_bytes | |
671 | + filename_size); | |
672 | } | |
673 | /* Octet 0: Tag 70 identifier | |
674 | * Octets 1-N1: Tag 70 packet size (includes cipher identifier | |
675 | * and block-aligned encrypted filename size) | |
676 | * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) | |
677 | * Octet N2-N3: Cipher identifier (1 octet) | |
678 | * Octets N3-N4: Block-aligned encrypted filename | |
679 | * - Consists of a minimum number of random characters, a \0 | |
680 | * separator, and then the filename */ | |
681 | s->max_packet_size = (1 /* Tag 70 identifier */ | |
682 | + 3 /* Max Tag 70 packet size */ | |
683 | + ECRYPTFS_SIG_SIZE /* FNEK sig */ | |
684 | + 1 /* Cipher identifier */ | |
685 | + s->block_aligned_filename_size); | |
686 | if (dest == NULL) { | |
687 | (*packet_size) = s->max_packet_size; | |
688 | goto out_unlock; | |
689 | } | |
690 | if (s->max_packet_size > (*remaining_bytes)) { | |
a8f12864 MH |
691 | printk(KERN_WARNING "%s: Require [%zd] bytes to write; only " |
692 | "[%zd] available\n", __func__, s->max_packet_size, | |
9c79f34f MH |
693 | (*remaining_bytes)); |
694 | rc = -EINVAL; | |
695 | goto out_unlock; | |
696 | } | |
697 | s->block_aligned_filename = kzalloc(s->block_aligned_filename_size, | |
698 | GFP_KERNEL); | |
699 | if (!s->block_aligned_filename) { | |
700 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " | |
df261c52 | 701 | "kzalloc [%zd] bytes\n", __func__, |
9c79f34f MH |
702 | s->block_aligned_filename_size); |
703 | rc = -ENOMEM; | |
704 | goto out_unlock; | |
705 | } | |
706 | s->i = 0; | |
707 | dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE; | |
708 | rc = ecryptfs_write_packet_length(&dest[s->i], | |
709 | (ECRYPTFS_SIG_SIZE | |
710 | + 1 /* Cipher code */ | |
711 | + s->block_aligned_filename_size), | |
712 | &s->packet_size_len); | |
713 | if (rc) { | |
714 | printk(KERN_ERR "%s: Error generating tag 70 packet " | |
715 | "header; cannot generate packet length; rc = [%d]\n", | |
716 | __func__, rc); | |
717 | goto out_free_unlock; | |
718 | } | |
719 | s->i += s->packet_size_len; | |
720 | ecryptfs_from_hex(&dest[s->i], | |
721 | mount_crypt_stat->global_default_fnek_sig, | |
722 | ECRYPTFS_SIG_SIZE); | |
723 | s->i += ECRYPTFS_SIG_SIZE; | |
724 | s->cipher_code = ecryptfs_code_for_cipher_string( | |
725 | mount_crypt_stat->global_default_fn_cipher_name, | |
726 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
727 | if (s->cipher_code == 0) { | |
728 | printk(KERN_WARNING "%s: Unable to generate code for " | |
a8f12864 | 729 | "cipher [%s] with key bytes [%zd]\n", __func__, |
9c79f34f MH |
730 | mount_crypt_stat->global_default_fn_cipher_name, |
731 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
732 | rc = -EINVAL; | |
733 | goto out_free_unlock; | |
734 | } | |
735 | dest[s->i++] = s->cipher_code; | |
9c79f34f MH |
736 | /* TODO: Support other key modules than passphrase for |
737 | * filename encryption */ | |
df6ad33b TH |
738 | if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) { |
739 | rc = -EOPNOTSUPP; | |
740 | printk(KERN_INFO "%s: Filename encryption only supports " | |
741 | "password tokens\n", __func__); | |
742 | goto out_free_unlock; | |
743 | } | |
9c79f34f MH |
744 | sg_init_one( |
745 | &s->hash_sg, | |
746 | (u8 *)s->auth_tok->token.password.session_key_encryption_key, | |
747 | s->auth_tok->token.password.session_key_encryption_key_bytes); | |
748 | s->hash_desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; | |
749 | s->hash_desc.tfm = crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST, 0, | |
750 | CRYPTO_ALG_ASYNC); | |
751 | if (IS_ERR(s->hash_desc.tfm)) { | |
752 | rc = PTR_ERR(s->hash_desc.tfm); | |
753 | printk(KERN_ERR "%s: Error attempting to " | |
754 | "allocate hash crypto context; rc = [%d]\n", | |
755 | __func__, rc); | |
756 | goto out_free_unlock; | |
757 | } | |
758 | rc = crypto_hash_init(&s->hash_desc); | |
759 | if (rc) { | |
760 | printk(KERN_ERR | |
761 | "%s: Error initializing crypto hash; rc = [%d]\n", | |
762 | __func__, rc); | |
763 | goto out_release_free_unlock; | |
764 | } | |
765 | rc = crypto_hash_update( | |
766 | &s->hash_desc, &s->hash_sg, | |
767 | s->auth_tok->token.password.session_key_encryption_key_bytes); | |
768 | if (rc) { | |
769 | printk(KERN_ERR | |
770 | "%s: Error updating crypto hash; rc = [%d]\n", | |
771 | __func__, rc); | |
772 | goto out_release_free_unlock; | |
773 | } | |
774 | rc = crypto_hash_final(&s->hash_desc, s->hash); | |
775 | if (rc) { | |
776 | printk(KERN_ERR | |
777 | "%s: Error finalizing crypto hash; rc = [%d]\n", | |
778 | __func__, rc); | |
779 | goto out_release_free_unlock; | |
780 | } | |
781 | for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) { | |
782 | s->block_aligned_filename[s->j] = | |
783 | s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)]; | |
784 | if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE) | |
785 | == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) { | |
786 | sg_init_one(&s->hash_sg, (u8 *)s->hash, | |
787 | ECRYPTFS_TAG_70_DIGEST_SIZE); | |
788 | rc = crypto_hash_init(&s->hash_desc); | |
789 | if (rc) { | |
790 | printk(KERN_ERR | |
791 | "%s: Error initializing crypto hash; " | |
792 | "rc = [%d]\n", __func__, rc); | |
793 | goto out_release_free_unlock; | |
794 | } | |
795 | rc = crypto_hash_update(&s->hash_desc, &s->hash_sg, | |
796 | ECRYPTFS_TAG_70_DIGEST_SIZE); | |
797 | if (rc) { | |
798 | printk(KERN_ERR | |
799 | "%s: Error updating crypto hash; " | |
800 | "rc = [%d]\n", __func__, rc); | |
801 | goto out_release_free_unlock; | |
802 | } | |
803 | rc = crypto_hash_final(&s->hash_desc, s->tmp_hash); | |
804 | if (rc) { | |
805 | printk(KERN_ERR | |
806 | "%s: Error finalizing crypto hash; " | |
807 | "rc = [%d]\n", __func__, rc); | |
808 | goto out_release_free_unlock; | |
809 | } | |
810 | memcpy(s->hash, s->tmp_hash, | |
811 | ECRYPTFS_TAG_70_DIGEST_SIZE); | |
812 | } | |
813 | if (s->block_aligned_filename[s->j] == '\0') | |
814 | s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL; | |
815 | } | |
816 | memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename, | |
817 | filename_size); | |
818 | rc = virt_to_scatterlist(s->block_aligned_filename, | |
8d08dab7 TH |
819 | s->block_aligned_filename_size, s->src_sg, 2); |
820 | if (rc < 1) { | |
9c79f34f | 821 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
8d08dab7 | 822 | "convert filename memory to scatterlist; rc = [%d]. " |
a8f12864 | 823 | "block_aligned_filename_size = [%zd]\n", __func__, rc, |
9c79f34f MH |
824 | s->block_aligned_filename_size); |
825 | goto out_release_free_unlock; | |
826 | } | |
827 | rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size, | |
8d08dab7 TH |
828 | s->dst_sg, 2); |
829 | if (rc < 1) { | |
9c79f34f MH |
830 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
831 | "convert encrypted filename memory to scatterlist; " | |
8d08dab7 TH |
832 | "rc = [%d]. block_aligned_filename_size = [%zd]\n", |
833 | __func__, rc, s->block_aligned_filename_size); | |
9c79f34f MH |
834 | goto out_release_free_unlock; |
835 | } | |
836 | /* The characters in the first block effectively do the job | |
837 | * of the IV here, so we just use 0's for the IV. Note the | |
838 | * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES | |
839 | * >= ECRYPTFS_MAX_IV_BYTES. */ | |
840 | memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES); | |
841 | s->desc.info = s->iv; | |
842 | rc = crypto_blkcipher_setkey( | |
843 | s->desc.tfm, | |
844 | s->auth_tok->token.password.session_key_encryption_key, | |
845 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
846 | if (rc < 0) { | |
847 | printk(KERN_ERR "%s: Error setting key for crypto context; " | |
848 | "rc = [%d]. s->auth_tok->token.password.session_key_" | |
849 | "encryption_key = [0x%p]; mount_crypt_stat->" | |
df261c52 | 850 | "global_default_fn_cipher_key_bytes = [%zd]\n", __func__, |
9c79f34f MH |
851 | rc, |
852 | s->auth_tok->token.password.session_key_encryption_key, | |
853 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
854 | goto out_release_free_unlock; | |
855 | } | |
8d08dab7 | 856 | rc = crypto_blkcipher_encrypt_iv(&s->desc, s->dst_sg, s->src_sg, |
9c79f34f MH |
857 | s->block_aligned_filename_size); |
858 | if (rc) { | |
859 | printk(KERN_ERR "%s: Error attempting to encrypt filename; " | |
860 | "rc = [%d]\n", __func__, rc); | |
861 | goto out_release_free_unlock; | |
862 | } | |
863 | s->i += s->block_aligned_filename_size; | |
864 | (*packet_size) = s->i; | |
865 | (*remaining_bytes) -= (*packet_size); | |
866 | out_release_free_unlock: | |
867 | crypto_free_hash(s->hash_desc.tfm); | |
868 | out_free_unlock: | |
00fcf2cb | 869 | kzfree(s->block_aligned_filename); |
9c79f34f MH |
870 | out_unlock: |
871 | mutex_unlock(s->tfm_mutex); | |
872 | out: | |
b5695d04 RS |
873 | if (auth_tok_key) { |
874 | up_write(&(auth_tok_key->sem)); | |
aee683b9 | 875 | key_put(auth_tok_key); |
b5695d04 | 876 | } |
9c79f34f MH |
877 | kfree(s); |
878 | return rc; | |
879 | } | |
880 | ||
881 | struct ecryptfs_parse_tag_70_packet_silly_stack { | |
882 | u8 cipher_code; | |
883 | size_t max_packet_size; | |
884 | size_t packet_size_len; | |
885 | size_t parsed_tag_70_packet_size; | |
886 | size_t block_aligned_filename_size; | |
887 | size_t block_size; | |
888 | size_t i; | |
889 | struct mutex *tfm_mutex; | |
890 | char *decrypted_filename; | |
891 | struct ecryptfs_auth_tok *auth_tok; | |
8d08dab7 TH |
892 | struct scatterlist src_sg[2]; |
893 | struct scatterlist dst_sg[2]; | |
9c79f34f MH |
894 | struct blkcipher_desc desc; |
895 | char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1]; | |
896 | char iv[ECRYPTFS_MAX_IV_BYTES]; | |
897 | char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE]; | |
898 | }; | |
899 | ||
900 | /** | |
901 | * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet | |
902 | * @filename: This function kmalloc's the memory for the filename | |
7d8bc2be MH |
903 | * @filename_size: This function sets this to the amount of memory |
904 | * kmalloc'd for the filename | |
905 | * @packet_size: This function sets this to the the number of octets | |
906 | * in the packet parsed | |
907 | * @mount_crypt_stat: The mount-wide cryptographic context | |
908 | * @data: The memory location containing the start of the tag 70 | |
909 | * packet | |
910 | * @max_packet_size: The maximum legal size of the packet to be parsed | |
911 | * from @data | |
912 | * | |
913 | * Returns zero on success; non-zero otherwise | |
9c79f34f MH |
914 | */ |
915 | int | |
916 | ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, | |
917 | size_t *packet_size, | |
918 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
919 | char *data, size_t max_packet_size) | |
920 | { | |
921 | struct ecryptfs_parse_tag_70_packet_silly_stack *s; | |
aee683b9 | 922 | struct key *auth_tok_key = NULL; |
9c79f34f MH |
923 | int rc = 0; |
924 | ||
925 | (*packet_size) = 0; | |
926 | (*filename_size) = 0; | |
927 | (*filename) = NULL; | |
928 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
929 | if (!s) { | |
930 | printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc " | |
a8f12864 | 931 | "[%zd] bytes of kernel memory\n", __func__, sizeof(*s)); |
f137f150 | 932 | rc = -ENOMEM; |
9c79f34f MH |
933 | goto out; |
934 | } | |
935 | s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; | |
936 | if (max_packet_size < (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)) { | |
df261c52 | 937 | printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be " |
9c79f34f MH |
938 | "at least [%d]\n", __func__, max_packet_size, |
939 | (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)); | |
940 | rc = -EINVAL; | |
941 | goto out; | |
942 | } | |
943 | /* Octet 0: Tag 70 identifier | |
944 | * Octets 1-N1: Tag 70 packet size (includes cipher identifier | |
945 | * and block-aligned encrypted filename size) | |
946 | * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) | |
947 | * Octet N2-N3: Cipher identifier (1 octet) | |
948 | * Octets N3-N4: Block-aligned encrypted filename | |
949 | * - Consists of a minimum number of random numbers, a \0 | |
950 | * separator, and then the filename */ | |
951 | if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) { | |
952 | printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be " | |
953 | "tag [0x%.2x]\n", __func__, | |
954 | data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE); | |
955 | rc = -EINVAL; | |
956 | goto out; | |
957 | } | |
958 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], | |
959 | &s->parsed_tag_70_packet_size, | |
960 | &s->packet_size_len); | |
961 | if (rc) { | |
962 | printk(KERN_WARNING "%s: Error parsing packet length; " | |
963 | "rc = [%d]\n", __func__, rc); | |
964 | goto out; | |
965 | } | |
966 | s->block_aligned_filename_size = (s->parsed_tag_70_packet_size | |
967 | - ECRYPTFS_SIG_SIZE - 1); | |
968 | if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size) | |
969 | > max_packet_size) { | |
a8f12864 MH |
970 | printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet " |
971 | "size is [%zd]\n", __func__, max_packet_size, | |
9c79f34f MH |
972 | (1 + s->packet_size_len + 1 |
973 | + s->block_aligned_filename_size)); | |
974 | rc = -EINVAL; | |
975 | goto out; | |
976 | } | |
977 | (*packet_size) += s->packet_size_len; | |
978 | ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)], | |
979 | ECRYPTFS_SIG_SIZE); | |
980 | s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0'; | |
981 | (*packet_size) += ECRYPTFS_SIG_SIZE; | |
982 | s->cipher_code = data[(*packet_size)++]; | |
983 | rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code); | |
984 | if (rc) { | |
985 | printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n", | |
986 | __func__, s->cipher_code); | |
987 | goto out; | |
988 | } | |
950983fc RS |
989 | rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key, |
990 | &s->auth_tok, mount_crypt_stat, | |
991 | s->fnek_sig_hex); | |
992 | if (rc) { | |
993 | printk(KERN_ERR "%s: Error attempting to find auth tok for " | |
994 | "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex, | |
995 | rc); | |
996 | goto out; | |
997 | } | |
9c79f34f MH |
998 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm, |
999 | &s->tfm_mutex, | |
1000 | s->cipher_string); | |
1001 | if (unlikely(rc)) { | |
1002 | printk(KERN_ERR "Internal error whilst attempting to get " | |
1003 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
1004 | s->cipher_string, rc); | |
1005 | goto out; | |
1006 | } | |
1007 | mutex_lock(s->tfm_mutex); | |
1008 | rc = virt_to_scatterlist(&data[(*packet_size)], | |
8d08dab7 TH |
1009 | s->block_aligned_filename_size, s->src_sg, 2); |
1010 | if (rc < 1) { | |
9c79f34f MH |
1011 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
1012 | "convert encrypted filename memory to scatterlist; " | |
8d08dab7 TH |
1013 | "rc = [%d]. block_aligned_filename_size = [%zd]\n", |
1014 | __func__, rc, s->block_aligned_filename_size); | |
9c79f34f MH |
1015 | goto out_unlock; |
1016 | } | |
1017 | (*packet_size) += s->block_aligned_filename_size; | |
1018 | s->decrypted_filename = kmalloc(s->block_aligned_filename_size, | |
1019 | GFP_KERNEL); | |
1020 | if (!s->decrypted_filename) { | |
1021 | printk(KERN_ERR "%s: Out of memory whilst attempting to " | |
a8f12864 | 1022 | "kmalloc [%zd] bytes\n", __func__, |
9c79f34f MH |
1023 | s->block_aligned_filename_size); |
1024 | rc = -ENOMEM; | |
1025 | goto out_unlock; | |
1026 | } | |
1027 | rc = virt_to_scatterlist(s->decrypted_filename, | |
8d08dab7 TH |
1028 | s->block_aligned_filename_size, s->dst_sg, 2); |
1029 | if (rc < 1) { | |
9c79f34f MH |
1030 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
1031 | "convert decrypted filename memory to scatterlist; " | |
8d08dab7 TH |
1032 | "rc = [%d]. block_aligned_filename_size = [%zd]\n", |
1033 | __func__, rc, s->block_aligned_filename_size); | |
9c79f34f MH |
1034 | goto out_free_unlock; |
1035 | } | |
1036 | /* The characters in the first block effectively do the job of | |
1037 | * the IV here, so we just use 0's for the IV. Note the | |
1038 | * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES | |
1039 | * >= ECRYPTFS_MAX_IV_BYTES. */ | |
1040 | memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES); | |
1041 | s->desc.info = s->iv; | |
9c79f34f MH |
1042 | /* TODO: Support other key modules than passphrase for |
1043 | * filename encryption */ | |
df6ad33b TH |
1044 | if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) { |
1045 | rc = -EOPNOTSUPP; | |
1046 | printk(KERN_INFO "%s: Filename encryption only supports " | |
1047 | "password tokens\n", __func__); | |
1048 | goto out_free_unlock; | |
1049 | } | |
9c79f34f MH |
1050 | rc = crypto_blkcipher_setkey( |
1051 | s->desc.tfm, | |
1052 | s->auth_tok->token.password.session_key_encryption_key, | |
1053 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
1054 | if (rc < 0) { | |
1055 | printk(KERN_ERR "%s: Error setting key for crypto context; " | |
1056 | "rc = [%d]. s->auth_tok->token.password.session_key_" | |
1057 | "encryption_key = [0x%p]; mount_crypt_stat->" | |
df261c52 | 1058 | "global_default_fn_cipher_key_bytes = [%zd]\n", __func__, |
9c79f34f MH |
1059 | rc, |
1060 | s->auth_tok->token.password.session_key_encryption_key, | |
1061 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
1062 | goto out_free_unlock; | |
1063 | } | |
8d08dab7 | 1064 | rc = crypto_blkcipher_decrypt_iv(&s->desc, s->dst_sg, s->src_sg, |
9c79f34f MH |
1065 | s->block_aligned_filename_size); |
1066 | if (rc) { | |
1067 | printk(KERN_ERR "%s: Error attempting to decrypt filename; " | |
1068 | "rc = [%d]\n", __func__, rc); | |
1069 | goto out_free_unlock; | |
1070 | } | |
1071 | s->i = 0; | |
1072 | while (s->decrypted_filename[s->i] != '\0' | |
1073 | && s->i < s->block_aligned_filename_size) | |
1074 | s->i++; | |
1075 | if (s->i == s->block_aligned_filename_size) { | |
1076 | printk(KERN_WARNING "%s: Invalid tag 70 packet; could not " | |
1077 | "find valid separator between random characters and " | |
1078 | "the filename\n", __func__); | |
1079 | rc = -EINVAL; | |
1080 | goto out_free_unlock; | |
1081 | } | |
1082 | s->i++; | |
1083 | (*filename_size) = (s->block_aligned_filename_size - s->i); | |
1084 | if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) { | |
df261c52 | 1085 | printk(KERN_WARNING "%s: Filename size is [%zd], which is " |
9c79f34f MH |
1086 | "invalid\n", __func__, (*filename_size)); |
1087 | rc = -EINVAL; | |
1088 | goto out_free_unlock; | |
1089 | } | |
1090 | (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL); | |
1091 | if (!(*filename)) { | |
1092 | printk(KERN_ERR "%s: Out of memory whilst attempting to " | |
a8f12864 | 1093 | "kmalloc [%zd] bytes\n", __func__, |
9c79f34f MH |
1094 | ((*filename_size) + 1)); |
1095 | rc = -ENOMEM; | |
1096 | goto out_free_unlock; | |
1097 | } | |
1098 | memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size)); | |
1099 | (*filename)[(*filename_size)] = '\0'; | |
1100 | out_free_unlock: | |
1101 | kfree(s->decrypted_filename); | |
1102 | out_unlock: | |
1103 | mutex_unlock(s->tfm_mutex); | |
1104 | out: | |
1105 | if (rc) { | |
1106 | (*packet_size) = 0; | |
1107 | (*filename_size) = 0; | |
1108 | (*filename) = NULL; | |
1109 | } | |
b5695d04 RS |
1110 | if (auth_tok_key) { |
1111 | up_write(&(auth_tok_key->sem)); | |
aee683b9 | 1112 | key_put(auth_tok_key); |
b5695d04 | 1113 | } |
9c79f34f MH |
1114 | kfree(s); |
1115 | return rc; | |
1116 | } | |
1117 | ||
cd9d67df MH |
1118 | static int |
1119 | ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok) | |
1120 | { | |
1121 | int rc = 0; | |
1122 | ||
1123 | (*sig) = NULL; | |
1124 | switch (auth_tok->token_type) { | |
1125 | case ECRYPTFS_PASSWORD: | |
1126 | (*sig) = auth_tok->token.password.signature; | |
1127 | break; | |
1128 | case ECRYPTFS_PRIVATE_KEY: | |
1129 | (*sig) = auth_tok->token.private_key.signature; | |
1130 | break; | |
1131 | default: | |
1132 | printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n", | |
1133 | auth_tok->token_type); | |
1134 | rc = -EINVAL; | |
1135 | } | |
1136 | return rc; | |
1137 | } | |
1138 | ||
dddfa461 | 1139 | /** |
22e78faf MH |
1140 | * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok. |
1141 | * @auth_tok: The key authentication token used to decrypt the session key | |
1142 | * @crypt_stat: The cryptographic context | |
dddfa461 | 1143 | * |
22e78faf | 1144 | * Returns zero on success; non-zero error otherwise. |
dddfa461 | 1145 | */ |
f4aad16a MH |
1146 | static int |
1147 | decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, | |
1148 | struct ecryptfs_crypt_stat *crypt_stat) | |
dddfa461 | 1149 | { |
19e66a67 | 1150 | u8 cipher_code = 0; |
dddfa461 MH |
1151 | struct ecryptfs_msg_ctx *msg_ctx; |
1152 | struct ecryptfs_message *msg = NULL; | |
f4aad16a | 1153 | char *auth_tok_sig; |
624ae528 TH |
1154 | char *payload; |
1155 | size_t payload_len; | |
dddfa461 MH |
1156 | int rc; |
1157 | ||
5dda6992 MH |
1158 | rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok); |
1159 | if (rc) { | |
f4aad16a MH |
1160 | printk(KERN_ERR "Unrecognized auth tok type: [%d]\n", |
1161 | auth_tok->token_type); | |
1162 | goto out; | |
1163 | } | |
1164 | rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key), | |
624ae528 | 1165 | &payload, &payload_len); |
dddfa461 | 1166 | if (rc) { |
f66e883e | 1167 | ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n"); |
dddfa461 MH |
1168 | goto out; |
1169 | } | |
624ae528 | 1170 | rc = ecryptfs_send_message(payload, payload_len, &msg_ctx); |
dddfa461 | 1171 | if (rc) { |
624ae528 TH |
1172 | ecryptfs_printk(KERN_ERR, "Error sending message to " |
1173 | "ecryptfsd\n"); | |
dddfa461 MH |
1174 | goto out; |
1175 | } | |
1176 | rc = ecryptfs_wait_for_response(msg_ctx, &msg); | |
1177 | if (rc) { | |
1178 | ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet " | |
1179 | "from the user space daemon\n"); | |
1180 | rc = -EIO; | |
1181 | goto out; | |
1182 | } | |
1183 | rc = parse_tag_65_packet(&(auth_tok->session_key), | |
1184 | &cipher_code, msg); | |
1185 | if (rc) { | |
1186 | printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n", | |
1187 | rc); | |
1188 | goto out; | |
1189 | } | |
1190 | auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1191 | memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, | |
1192 | auth_tok->session_key.decrypted_key_size); | |
1193 | crypt_stat->key_size = auth_tok->session_key.decrypted_key_size; | |
1194 | rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code); | |
1195 | if (rc) { | |
1196 | ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n", | |
1197 | cipher_code) | |
1198 | goto out; | |
1199 | } | |
1200 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; | |
1201 | if (ecryptfs_verbosity > 0) { | |
1202 | ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n"); | |
1203 | ecryptfs_dump_hex(crypt_stat->key, | |
1204 | crypt_stat->key_size); | |
1205 | } | |
1206 | out: | |
1207 | if (msg) | |
1208 | kfree(msg); | |
1209 | return rc; | |
1210 | } | |
1211 | ||
1212 | static void wipe_auth_tok_list(struct list_head *auth_tok_list_head) | |
1213 | { | |
dddfa461 | 1214 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
e0869cc1 | 1215 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
dddfa461 | 1216 | |
e0869cc1 MH |
1217 | list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp, |
1218 | auth_tok_list_head, list) { | |
1219 | list_del(&auth_tok_list_item->list); | |
dddfa461 MH |
1220 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, |
1221 | auth_tok_list_item); | |
1222 | } | |
dddfa461 MH |
1223 | } |
1224 | ||
1225 | struct kmem_cache *ecryptfs_auth_tok_list_item_cache; | |
1226 | ||
dddfa461 MH |
1227 | /** |
1228 | * parse_tag_1_packet | |
22e78faf | 1229 | * @crypt_stat: The cryptographic context to modify based on packet contents |
dddfa461 MH |
1230 | * @data: The raw bytes of the packet. |
1231 | * @auth_tok_list: eCryptfs parses packets into authentication tokens; | |
22e78faf MH |
1232 | * a new authentication token will be placed at the |
1233 | * end of this list for this packet. | |
dddfa461 MH |
1234 | * @new_auth_tok: Pointer to a pointer to memory that this function |
1235 | * allocates; sets the memory address of the pointer to | |
1236 | * NULL on error. This object is added to the | |
1237 | * auth_tok_list. | |
1238 | * @packet_size: This function writes the size of the parsed packet | |
1239 | * into this memory location; zero on error. | |
22e78faf | 1240 | * @max_packet_size: The maximum allowable packet size |
dddfa461 MH |
1241 | * |
1242 | * Returns zero on success; non-zero on error. | |
1243 | */ | |
1244 | static int | |
1245 | parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat, | |
1246 | unsigned char *data, struct list_head *auth_tok_list, | |
1247 | struct ecryptfs_auth_tok **new_auth_tok, | |
1248 | size_t *packet_size, size_t max_packet_size) | |
1249 | { | |
1250 | size_t body_size; | |
1251 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; | |
1252 | size_t length_size; | |
1253 | int rc = 0; | |
1254 | ||
1255 | (*packet_size) = 0; | |
1256 | (*new_auth_tok) = NULL; | |
13218179 MH |
1257 | /** |
1258 | * This format is inspired by OpenPGP; see RFC 2440 | |
1259 | * packet tag 1 | |
1260 | * | |
1261 | * Tag 1 identifier (1 byte) | |
1262 | * Max Tag 1 packet size (max 3 bytes) | |
1263 | * Version (1 byte) | |
1264 | * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE) | |
1265 | * Cipher identifier (1 byte) | |
1266 | * Encrypted key size (arbitrary) | |
1267 | * | |
1268 | * 12 bytes minimum packet size | |
dddfa461 | 1269 | */ |
13218179 MH |
1270 | if (unlikely(max_packet_size < 12)) { |
1271 | printk(KERN_ERR "Invalid max packet size; must be >=12\n"); | |
dddfa461 MH |
1272 | rc = -EINVAL; |
1273 | goto out; | |
1274 | } | |
dddfa461 | 1275 | if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) { |
13218179 MH |
1276 | printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n", |
1277 | ECRYPTFS_TAG_1_PACKET_TYPE); | |
dddfa461 MH |
1278 | rc = -EINVAL; |
1279 | goto out; | |
1280 | } | |
1281 | /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or | |
1282 | * at end of function upon failure */ | |
1283 | auth_tok_list_item = | |
13218179 MH |
1284 | kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, |
1285 | GFP_KERNEL); | |
dddfa461 | 1286 | if (!auth_tok_list_item) { |
13218179 | 1287 | printk(KERN_ERR "Unable to allocate memory\n"); |
dddfa461 MH |
1288 | rc = -ENOMEM; |
1289 | goto out; | |
1290 | } | |
dddfa461 | 1291 | (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
f66e883e MH |
1292 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1293 | &length_size); | |
5dda6992 | 1294 | if (rc) { |
13218179 MH |
1295 | printk(KERN_WARNING "Error parsing packet length; " |
1296 | "rc = [%d]\n", rc); | |
dddfa461 MH |
1297 | goto out_free; |
1298 | } | |
13218179 | 1299 | if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) { |
81acbcd6 | 1300 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
dddfa461 MH |
1301 | rc = -EINVAL; |
1302 | goto out_free; | |
1303 | } | |
1304 | (*packet_size) += length_size; | |
1305 | if (unlikely((*packet_size) + body_size > max_packet_size)) { | |
13218179 | 1306 | printk(KERN_WARNING "Packet size exceeds max\n"); |
dddfa461 MH |
1307 | rc = -EINVAL; |
1308 | goto out_free; | |
1309 | } | |
dddfa461 | 1310 | if (unlikely(data[(*packet_size)++] != 0x03)) { |
13218179 MH |
1311 | printk(KERN_WARNING "Unknown version number [%d]\n", |
1312 | data[(*packet_size) - 1]); | |
dddfa461 MH |
1313 | rc = -EINVAL; |
1314 | goto out_free; | |
1315 | } | |
dddfa461 MH |
1316 | ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature, |
1317 | &data[(*packet_size)], ECRYPTFS_SIG_SIZE); | |
1318 | *packet_size += ECRYPTFS_SIG_SIZE; | |
1319 | /* This byte is skipped because the kernel does not need to | |
1320 | * know which public key encryption algorithm was used */ | |
1321 | (*packet_size)++; | |
1322 | (*new_auth_tok)->session_key.encrypted_key_size = | |
13218179 | 1323 | body_size - (ECRYPTFS_SIG_SIZE + 2); |
dddfa461 MH |
1324 | if ((*new_auth_tok)->session_key.encrypted_key_size |
1325 | > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
13218179 MH |
1326 | printk(KERN_WARNING "Tag 1 packet contains key larger " |
1327 | "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES"); | |
dddfa461 MH |
1328 | rc = -EINVAL; |
1329 | goto out; | |
1330 | } | |
dddfa461 | 1331 | memcpy((*new_auth_tok)->session_key.encrypted_key, |
13218179 | 1332 | &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2))); |
dddfa461 MH |
1333 | (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size; |
1334 | (*new_auth_tok)->session_key.flags &= | |
1335 | ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1336 | (*new_auth_tok)->session_key.flags |= | |
1337 | ECRYPTFS_CONTAINS_ENCRYPTED_KEY; | |
1338 | (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY; | |
13218179 | 1339 | (*new_auth_tok)->flags = 0; |
e2bd99ec MH |
1340 | (*new_auth_tok)->session_key.flags &= |
1341 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT); | |
1342 | (*new_auth_tok)->session_key.flags &= | |
1343 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT); | |
dddfa461 MH |
1344 | list_add(&auth_tok_list_item->list, auth_tok_list); |
1345 | goto out; | |
1346 | out_free: | |
1347 | (*new_auth_tok) = NULL; | |
1348 | memset(auth_tok_list_item, 0, | |
1349 | sizeof(struct ecryptfs_auth_tok_list_item)); | |
1350 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, | |
1351 | auth_tok_list_item); | |
1352 | out: | |
1353 | if (rc) | |
1354 | (*packet_size) = 0; | |
1355 | return rc; | |
1356 | } | |
1357 | ||
237fead6 MH |
1358 | /** |
1359 | * parse_tag_3_packet | |
1360 | * @crypt_stat: The cryptographic context to modify based on packet | |
1361 | * contents. | |
1362 | * @data: The raw bytes of the packet. | |
1363 | * @auth_tok_list: eCryptfs parses packets into authentication tokens; | |
1364 | * a new authentication token will be placed at the end | |
1365 | * of this list for this packet. | |
1366 | * @new_auth_tok: Pointer to a pointer to memory that this function | |
1367 | * allocates; sets the memory address of the pointer to | |
1368 | * NULL on error. This object is added to the | |
1369 | * auth_tok_list. | |
1370 | * @packet_size: This function writes the size of the parsed packet | |
1371 | * into this memory location; zero on error. | |
1372 | * @max_packet_size: maximum number of bytes to parse | |
1373 | * | |
1374 | * Returns zero on success; non-zero on error. | |
1375 | */ | |
1376 | static int | |
1377 | parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat, | |
1378 | unsigned char *data, struct list_head *auth_tok_list, | |
1379 | struct ecryptfs_auth_tok **new_auth_tok, | |
1380 | size_t *packet_size, size_t max_packet_size) | |
1381 | { | |
237fead6 MH |
1382 | size_t body_size; |
1383 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; | |
1384 | size_t length_size; | |
dddfa461 | 1385 | int rc = 0; |
237fead6 MH |
1386 | |
1387 | (*packet_size) = 0; | |
1388 | (*new_auth_tok) = NULL; | |
c59becfc MH |
1389 | /** |
1390 | *This format is inspired by OpenPGP; see RFC 2440 | |
1391 | * packet tag 3 | |
1392 | * | |
1393 | * Tag 3 identifier (1 byte) | |
1394 | * Max Tag 3 packet size (max 3 bytes) | |
1395 | * Version (1 byte) | |
1396 | * Cipher code (1 byte) | |
1397 | * S2K specifier (1 byte) | |
1398 | * Hash identifier (1 byte) | |
1399 | * Salt (ECRYPTFS_SALT_SIZE) | |
1400 | * Hash iterations (1 byte) | |
1401 | * Encrypted key (arbitrary) | |
1402 | * | |
1403 | * (ECRYPTFS_SALT_SIZE + 7) minimum packet size | |
237fead6 | 1404 | */ |
c59becfc MH |
1405 | if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) { |
1406 | printk(KERN_ERR "Max packet size too large\n"); | |
237fead6 MH |
1407 | rc = -EINVAL; |
1408 | goto out; | |
1409 | } | |
237fead6 | 1410 | if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) { |
c59becfc MH |
1411 | printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n", |
1412 | ECRYPTFS_TAG_3_PACKET_TYPE); | |
237fead6 MH |
1413 | rc = -EINVAL; |
1414 | goto out; | |
1415 | } | |
1416 | /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or | |
1417 | * at end of function upon failure */ | |
1418 | auth_tok_list_item = | |
c3762229 | 1419 | kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL); |
237fead6 | 1420 | if (!auth_tok_list_item) { |
c59becfc | 1421 | printk(KERN_ERR "Unable to allocate memory\n"); |
237fead6 MH |
1422 | rc = -ENOMEM; |
1423 | goto out; | |
1424 | } | |
237fead6 | 1425 | (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
f66e883e MH |
1426 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1427 | &length_size); | |
5dda6992 | 1428 | if (rc) { |
c59becfc MH |
1429 | printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n", |
1430 | rc); | |
237fead6 MH |
1431 | goto out_free; |
1432 | } | |
c59becfc | 1433 | if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) { |
81acbcd6 | 1434 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
237fead6 MH |
1435 | rc = -EINVAL; |
1436 | goto out_free; | |
1437 | } | |
1438 | (*packet_size) += length_size; | |
237fead6 | 1439 | if (unlikely((*packet_size) + body_size > max_packet_size)) { |
c59becfc | 1440 | printk(KERN_ERR "Packet size exceeds max\n"); |
237fead6 MH |
1441 | rc = -EINVAL; |
1442 | goto out_free; | |
1443 | } | |
237fead6 | 1444 | (*new_auth_tok)->session_key.encrypted_key_size = |
c59becfc | 1445 | (body_size - (ECRYPTFS_SALT_SIZE + 5)); |
f151cd2c RCV |
1446 | if ((*new_auth_tok)->session_key.encrypted_key_size |
1447 | > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
1448 | printk(KERN_WARNING "Tag 3 packet contains key larger " | |
1449 | "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n"); | |
1450 | rc = -EINVAL; | |
1451 | goto out_free; | |
1452 | } | |
237fead6 | 1453 | if (unlikely(data[(*packet_size)++] != 0x04)) { |
c59becfc MH |
1454 | printk(KERN_WARNING "Unknown version number [%d]\n", |
1455 | data[(*packet_size) - 1]); | |
237fead6 MH |
1456 | rc = -EINVAL; |
1457 | goto out_free; | |
1458 | } | |
b0105eae TH |
1459 | rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, |
1460 | (u16)data[(*packet_size)]); | |
1461 | if (rc) | |
1462 | goto out_free; | |
237fead6 MH |
1463 | /* A little extra work to differentiate among the AES key |
1464 | * sizes; see RFC2440 */ | |
1465 | switch(data[(*packet_size)++]) { | |
1466 | case RFC2440_CIPHER_AES_192: | |
1467 | crypt_stat->key_size = 24; | |
1468 | break; | |
1469 | default: | |
1470 | crypt_stat->key_size = | |
1471 | (*new_auth_tok)->session_key.encrypted_key_size; | |
1472 | } | |
b0105eae TH |
1473 | rc = ecryptfs_init_crypt_ctx(crypt_stat); |
1474 | if (rc) | |
1475 | goto out_free; | |
237fead6 | 1476 | if (unlikely(data[(*packet_size)++] != 0x03)) { |
c59becfc | 1477 | printk(KERN_WARNING "Only S2K ID 3 is currently supported\n"); |
237fead6 MH |
1478 | rc = -ENOSYS; |
1479 | goto out_free; | |
1480 | } | |
237fead6 | 1481 | /* TODO: finish the hash mapping */ |
237fead6 MH |
1482 | switch (data[(*packet_size)++]) { |
1483 | case 0x01: /* See RFC2440 for these numbers and their mappings */ | |
1484 | /* Choose MD5 */ | |
237fead6 MH |
1485 | memcpy((*new_auth_tok)->token.password.salt, |
1486 | &data[(*packet_size)], ECRYPTFS_SALT_SIZE); | |
1487 | (*packet_size) += ECRYPTFS_SALT_SIZE; | |
237fead6 | 1488 | /* This conversion was taken straight from RFC2440 */ |
237fead6 MH |
1489 | (*new_auth_tok)->token.password.hash_iterations = |
1490 | ((u32) 16 + (data[(*packet_size)] & 15)) | |
1491 | << ((data[(*packet_size)] >> 4) + 6); | |
1492 | (*packet_size)++; | |
c59becfc MH |
1493 | /* Friendly reminder: |
1494 | * (*new_auth_tok)->session_key.encrypted_key_size = | |
1495 | * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */ | |
237fead6 MH |
1496 | memcpy((*new_auth_tok)->session_key.encrypted_key, |
1497 | &data[(*packet_size)], | |
1498 | (*new_auth_tok)->session_key.encrypted_key_size); | |
1499 | (*packet_size) += | |
1500 | (*new_auth_tok)->session_key.encrypted_key_size; | |
1501 | (*new_auth_tok)->session_key.flags &= | |
1502 | ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1503 | (*new_auth_tok)->session_key.flags |= | |
1504 | ECRYPTFS_CONTAINS_ENCRYPTED_KEY; | |
c59becfc | 1505 | (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */ |
237fead6 MH |
1506 | break; |
1507 | default: | |
1508 | ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: " | |
1509 | "[%d]\n", data[(*packet_size) - 1]); | |
1510 | rc = -ENOSYS; | |
1511 | goto out_free; | |
1512 | } | |
1513 | (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD; | |
1514 | /* TODO: Parametarize; we might actually want userspace to | |
1515 | * decrypt the session key. */ | |
e2bd99ec MH |
1516 | (*new_auth_tok)->session_key.flags &= |
1517 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT); | |
1518 | (*new_auth_tok)->session_key.flags &= | |
1519 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT); | |
237fead6 MH |
1520 | list_add(&auth_tok_list_item->list, auth_tok_list); |
1521 | goto out; | |
1522 | out_free: | |
1523 | (*new_auth_tok) = NULL; | |
1524 | memset(auth_tok_list_item, 0, | |
1525 | sizeof(struct ecryptfs_auth_tok_list_item)); | |
1526 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, | |
1527 | auth_tok_list_item); | |
1528 | out: | |
1529 | if (rc) | |
1530 | (*packet_size) = 0; | |
1531 | return rc; | |
1532 | } | |
1533 | ||
1534 | /** | |
1535 | * parse_tag_11_packet | |
1536 | * @data: The raw bytes of the packet | |
1537 | * @contents: This function writes the data contents of the literal | |
1538 | * packet into this memory location | |
1539 | * @max_contents_bytes: The maximum number of bytes that this function | |
1540 | * is allowed to write into contents | |
1541 | * @tag_11_contents_size: This function writes the size of the parsed | |
1542 | * contents into this memory location; zero on | |
1543 | * error | |
1544 | * @packet_size: This function writes the size of the parsed packet | |
1545 | * into this memory location; zero on error | |
1546 | * @max_packet_size: maximum number of bytes to parse | |
1547 | * | |
1548 | * Returns zero on success; non-zero on error. | |
1549 | */ | |
1550 | static int | |
1551 | parse_tag_11_packet(unsigned char *data, unsigned char *contents, | |
1552 | size_t max_contents_bytes, size_t *tag_11_contents_size, | |
1553 | size_t *packet_size, size_t max_packet_size) | |
1554 | { | |
237fead6 MH |
1555 | size_t body_size; |
1556 | size_t length_size; | |
dddfa461 | 1557 | int rc = 0; |
237fead6 MH |
1558 | |
1559 | (*packet_size) = 0; | |
1560 | (*tag_11_contents_size) = 0; | |
f648104a MH |
1561 | /* This format is inspired by OpenPGP; see RFC 2440 |
1562 | * packet tag 11 | |
1563 | * | |
1564 | * Tag 11 identifier (1 byte) | |
1565 | * Max Tag 11 packet size (max 3 bytes) | |
1566 | * Binary format specifier (1 byte) | |
1567 | * Filename length (1 byte) | |
1568 | * Filename ("_CONSOLE") (8 bytes) | |
1569 | * Modification date (4 bytes) | |
1570 | * Literal data (arbitrary) | |
1571 | * | |
1572 | * We need at least 16 bytes of data for the packet to even be | |
1573 | * valid. | |
237fead6 | 1574 | */ |
f648104a MH |
1575 | if (max_packet_size < 16) { |
1576 | printk(KERN_ERR "Maximum packet size too small\n"); | |
237fead6 MH |
1577 | rc = -EINVAL; |
1578 | goto out; | |
1579 | } | |
237fead6 | 1580 | if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) { |
f648104a | 1581 | printk(KERN_WARNING "Invalid tag 11 packet format\n"); |
237fead6 MH |
1582 | rc = -EINVAL; |
1583 | goto out; | |
1584 | } | |
f66e883e MH |
1585 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1586 | &length_size); | |
5dda6992 | 1587 | if (rc) { |
f648104a | 1588 | printk(KERN_WARNING "Invalid tag 11 packet format\n"); |
237fead6 MH |
1589 | goto out; |
1590 | } | |
f648104a | 1591 | if (body_size < 14) { |
81acbcd6 | 1592 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
237fead6 MH |
1593 | rc = -EINVAL; |
1594 | goto out; | |
1595 | } | |
f648104a MH |
1596 | (*packet_size) += length_size; |
1597 | (*tag_11_contents_size) = (body_size - 14); | |
237fead6 | 1598 | if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) { |
f648104a | 1599 | printk(KERN_ERR "Packet size exceeds max\n"); |
237fead6 MH |
1600 | rc = -EINVAL; |
1601 | goto out; | |
1602 | } | |
6352a293 TH |
1603 | if (unlikely((*tag_11_contents_size) > max_contents_bytes)) { |
1604 | printk(KERN_ERR "Literal data section in tag 11 packet exceeds " | |
1605 | "expected size\n"); | |
1606 | rc = -EINVAL; | |
1607 | goto out; | |
1608 | } | |
237fead6 | 1609 | if (data[(*packet_size)++] != 0x62) { |
f648104a | 1610 | printk(KERN_WARNING "Unrecognizable packet\n"); |
237fead6 MH |
1611 | rc = -EINVAL; |
1612 | goto out; | |
1613 | } | |
237fead6 | 1614 | if (data[(*packet_size)++] != 0x08) { |
f648104a | 1615 | printk(KERN_WARNING "Unrecognizable packet\n"); |
237fead6 MH |
1616 | rc = -EINVAL; |
1617 | goto out; | |
1618 | } | |
f648104a | 1619 | (*packet_size) += 12; /* Ignore filename and modification date */ |
237fead6 MH |
1620 | memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size)); |
1621 | (*packet_size) += (*tag_11_contents_size); | |
237fead6 MH |
1622 | out: |
1623 | if (rc) { | |
1624 | (*packet_size) = 0; | |
1625 | (*tag_11_contents_size) = 0; | |
1626 | } | |
1627 | return rc; | |
1628 | } | |
1629 | ||
f4aad16a MH |
1630 | int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key, |
1631 | struct ecryptfs_auth_tok **auth_tok, | |
1632 | char *sig) | |
1633 | { | |
1634 | int rc = 0; | |
1635 | ||
1636 | (*auth_tok_key) = request_key(&key_type_user, sig, NULL); | |
1637 | if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) { | |
1252cc3b RS |
1638 | (*auth_tok_key) = ecryptfs_get_encrypted_key(sig); |
1639 | if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) { | |
1640 | printk(KERN_ERR "Could not find key with description: [%s]\n", | |
1641 | sig); | |
1642 | rc = process_request_key_err(PTR_ERR(*auth_tok_key)); | |
1643 | (*auth_tok_key) = NULL; | |
1644 | goto out; | |
1645 | } | |
f4aad16a | 1646 | } |
b5695d04 | 1647 | down_write(&(*auth_tok_key)->sem); |
0e1fc5ef | 1648 | rc = ecryptfs_verify_auth_tok_from_key(*auth_tok_key, auth_tok); |
aee683b9 | 1649 | if (rc) { |
b5695d04 | 1650 | up_write(&(*auth_tok_key)->sem); |
aee683b9 RS |
1651 | key_put(*auth_tok_key); |
1652 | (*auth_tok_key) = NULL; | |
0e1fc5ef | 1653 | goto out; |
f4aad16a MH |
1654 | } |
1655 | out: | |
1656 | return rc; | |
1657 | } | |
1658 | ||
f4aad16a | 1659 | /** |
22e78faf MH |
1660 | * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok. |
1661 | * @auth_tok: The passphrase authentication token to use to encrypt the FEK | |
1662 | * @crypt_stat: The cryptographic context | |
237fead6 | 1663 | * |
22e78faf | 1664 | * Returns zero on success; non-zero error otherwise |
237fead6 | 1665 | */ |
f4aad16a MH |
1666 | static int |
1667 | decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, | |
1668 | struct ecryptfs_crypt_stat *crypt_stat) | |
237fead6 | 1669 | { |
ac97b9f9 MH |
1670 | struct scatterlist dst_sg[2]; |
1671 | struct scatterlist src_sg[2]; | |
dd8e2902 | 1672 | struct mutex *tfm_mutex; |
8bba066f MH |
1673 | struct blkcipher_desc desc = { |
1674 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
1675 | }; | |
1676 | int rc = 0; | |
237fead6 | 1677 | |
f4aad16a MH |
1678 | if (unlikely(ecryptfs_verbosity > 0)) { |
1679 | ecryptfs_printk( | |
1680 | KERN_DEBUG, "Session key encryption key (size [%d]):\n", | |
1681 | auth_tok->token.password.session_key_encryption_key_bytes); | |
1682 | ecryptfs_dump_hex( | |
1683 | auth_tok->token.password.session_key_encryption_key, | |
1684 | auth_tok->token.password.session_key_encryption_key_bytes); | |
1685 | } | |
1686 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex, | |
1687 | crypt_stat->cipher); | |
1688 | if (unlikely(rc)) { | |
1689 | printk(KERN_ERR "Internal error whilst attempting to get " | |
1690 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
1691 | crypt_stat->cipher, rc); | |
1692 | goto out; | |
237fead6 | 1693 | } |
5dda6992 MH |
1694 | rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key, |
1695 | auth_tok->session_key.encrypted_key_size, | |
ac97b9f9 MH |
1696 | src_sg, 2); |
1697 | if (rc < 1 || rc > 2) { | |
f4aad16a MH |
1698 | printk(KERN_ERR "Internal error whilst attempting to convert " |
1699 | "auth_tok->session_key.encrypted_key to scatterlist; " | |
1700 | "expected rc = 1; got rc = [%d]. " | |
1701 | "auth_tok->session_key.encrypted_key_size = [%d]\n", rc, | |
1702 | auth_tok->session_key.encrypted_key_size); | |
1703 | goto out; | |
1704 | } | |
1705 | auth_tok->session_key.decrypted_key_size = | |
1706 | auth_tok->session_key.encrypted_key_size; | |
5dda6992 MH |
1707 | rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key, |
1708 | auth_tok->session_key.decrypted_key_size, | |
ac97b9f9 MH |
1709 | dst_sg, 2); |
1710 | if (rc < 1 || rc > 2) { | |
f4aad16a MH |
1711 | printk(KERN_ERR "Internal error whilst attempting to convert " |
1712 | "auth_tok->session_key.decrypted_key to scatterlist; " | |
1713 | "expected rc = 1; got rc = [%d]\n", rc); | |
1714 | goto out; | |
1715 | } | |
1716 | mutex_lock(tfm_mutex); | |
1717 | rc = crypto_blkcipher_setkey( | |
1718 | desc.tfm, auth_tok->token.password.session_key_encryption_key, | |
1719 | crypt_stat->key_size); | |
1720 | if (unlikely(rc < 0)) { | |
1721 | mutex_unlock(tfm_mutex); | |
e5d9cbde MH |
1722 | printk(KERN_ERR "Error setting key for crypto context\n"); |
1723 | rc = -EINVAL; | |
f4aad16a | 1724 | goto out; |
237fead6 | 1725 | } |
ac97b9f9 | 1726 | rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg, |
8bba066f | 1727 | auth_tok->session_key.encrypted_key_size); |
f4aad16a MH |
1728 | mutex_unlock(tfm_mutex); |
1729 | if (unlikely(rc)) { | |
8bba066f | 1730 | printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc); |
f4aad16a | 1731 | goto out; |
8bba066f | 1732 | } |
237fead6 MH |
1733 | auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; |
1734 | memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, | |
1735 | auth_tok->session_key.decrypted_key_size); | |
e2bd99ec | 1736 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; |
f4aad16a | 1737 | if (unlikely(ecryptfs_verbosity > 0)) { |
f24b3887 | 1738 | ecryptfs_printk(KERN_DEBUG, "FEK of size [%zd]:\n", |
f4aad16a | 1739 | crypt_stat->key_size); |
237fead6 MH |
1740 | ecryptfs_dump_hex(crypt_stat->key, |
1741 | crypt_stat->key_size); | |
f4aad16a | 1742 | } |
237fead6 MH |
1743 | out: |
1744 | return rc; | |
1745 | } | |
1746 | ||
1747 | /** | |
1748 | * ecryptfs_parse_packet_set | |
22e78faf MH |
1749 | * @crypt_stat: The cryptographic context |
1750 | * @src: Virtual address of region of memory containing the packets | |
1751 | * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set | |
237fead6 MH |
1752 | * |
1753 | * Get crypt_stat to have the file's session key if the requisite key | |
1754 | * is available to decrypt the session key. | |
1755 | * | |
1756 | * Returns Zero if a valid authentication token was retrieved and | |
1757 | * processed; negative value for file not encrypted or for error | |
1758 | * conditions. | |
1759 | */ | |
1760 | int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat, | |
1761 | unsigned char *src, | |
1762 | struct dentry *ecryptfs_dentry) | |
1763 | { | |
1764 | size_t i = 0; | |
f4aad16a | 1765 | size_t found_auth_tok; |
237fead6 | 1766 | size_t next_packet_is_auth_tok_packet; |
237fead6 | 1767 | struct list_head auth_tok_list; |
dd8e2902 MH |
1768 | struct ecryptfs_auth_tok *matching_auth_tok; |
1769 | struct ecryptfs_auth_tok *candidate_auth_tok; | |
f4aad16a | 1770 | char *candidate_auth_tok_sig; |
237fead6 MH |
1771 | size_t packet_size; |
1772 | struct ecryptfs_auth_tok *new_auth_tok; | |
1773 | unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE]; | |
f4aad16a | 1774 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
237fead6 MH |
1775 | size_t tag_11_contents_size; |
1776 | size_t tag_11_packet_size; | |
aee683b9 | 1777 | struct key *auth_tok_key = NULL; |
dddfa461 | 1778 | int rc = 0; |
237fead6 MH |
1779 | |
1780 | INIT_LIST_HEAD(&auth_tok_list); | |
f4aad16a | 1781 | /* Parse the header to find as many packets as we can; these will be |
237fead6 MH |
1782 | * added the our &auth_tok_list */ |
1783 | next_packet_is_auth_tok_packet = 1; | |
1784 | while (next_packet_is_auth_tok_packet) { | |
1785 | size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i); | |
1786 | ||
1787 | switch (src[i]) { | |
1788 | case ECRYPTFS_TAG_3_PACKET_TYPE: | |
1789 | rc = parse_tag_3_packet(crypt_stat, | |
1790 | (unsigned char *)&src[i], | |
1791 | &auth_tok_list, &new_auth_tok, | |
1792 | &packet_size, max_packet_size); | |
1793 | if (rc) { | |
1794 | ecryptfs_printk(KERN_ERR, "Error parsing " | |
1795 | "tag 3 packet\n"); | |
1796 | rc = -EIO; | |
1797 | goto out_wipe_list; | |
1798 | } | |
1799 | i += packet_size; | |
1800 | rc = parse_tag_11_packet((unsigned char *)&src[i], | |
1801 | sig_tmp_space, | |
1802 | ECRYPTFS_SIG_SIZE, | |
1803 | &tag_11_contents_size, | |
1804 | &tag_11_packet_size, | |
1805 | max_packet_size); | |
1806 | if (rc) { | |
1807 | ecryptfs_printk(KERN_ERR, "No valid " | |
1808 | "(ecryptfs-specific) literal " | |
1809 | "packet containing " | |
1810 | "authentication token " | |
1811 | "signature found after " | |
1812 | "tag 3 packet\n"); | |
1813 | rc = -EIO; | |
1814 | goto out_wipe_list; | |
1815 | } | |
1816 | i += tag_11_packet_size; | |
1817 | if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) { | |
1818 | ecryptfs_printk(KERN_ERR, "Expected " | |
1819 | "signature of size [%d]; " | |
f24b3887 | 1820 | "read size [%zd]\n", |
237fead6 MH |
1821 | ECRYPTFS_SIG_SIZE, |
1822 | tag_11_contents_size); | |
1823 | rc = -EIO; | |
1824 | goto out_wipe_list; | |
1825 | } | |
1826 | ecryptfs_to_hex(new_auth_tok->token.password.signature, | |
1827 | sig_tmp_space, tag_11_contents_size); | |
1828 | new_auth_tok->token.password.signature[ | |
1829 | ECRYPTFS_PASSWORD_SIG_SIZE] = '\0'; | |
e2bd99ec | 1830 | crypt_stat->flags |= ECRYPTFS_ENCRYPTED; |
237fead6 | 1831 | break; |
dddfa461 MH |
1832 | case ECRYPTFS_TAG_1_PACKET_TYPE: |
1833 | rc = parse_tag_1_packet(crypt_stat, | |
1834 | (unsigned char *)&src[i], | |
1835 | &auth_tok_list, &new_auth_tok, | |
1836 | &packet_size, max_packet_size); | |
1837 | if (rc) { | |
1838 | ecryptfs_printk(KERN_ERR, "Error parsing " | |
1839 | "tag 1 packet\n"); | |
1840 | rc = -EIO; | |
1841 | goto out_wipe_list; | |
1842 | } | |
1843 | i += packet_size; | |
e2bd99ec | 1844 | crypt_stat->flags |= ECRYPTFS_ENCRYPTED; |
dddfa461 | 1845 | break; |
237fead6 MH |
1846 | case ECRYPTFS_TAG_11_PACKET_TYPE: |
1847 | ecryptfs_printk(KERN_WARNING, "Invalid packet set " | |
1848 | "(Tag 11 not allowed by itself)\n"); | |
1849 | rc = -EIO; | |
1850 | goto out_wipe_list; | |
1851 | break; | |
1852 | default: | |
f24b3887 TH |
1853 | ecryptfs_printk(KERN_DEBUG, "No packet at offset [%zd] " |
1854 | "of the file header; hex value of " | |
237fead6 MH |
1855 | "character is [0x%.2x]\n", i, src[i]); |
1856 | next_packet_is_auth_tok_packet = 0; | |
1857 | } | |
1858 | } | |
1859 | if (list_empty(&auth_tok_list)) { | |
f4aad16a MH |
1860 | printk(KERN_ERR "The lower file appears to be a non-encrypted " |
1861 | "eCryptfs file; this is not supported in this version " | |
1862 | "of the eCryptfs kernel module\n"); | |
1863 | rc = -EINVAL; | |
237fead6 MH |
1864 | goto out; |
1865 | } | |
f4aad16a MH |
1866 | /* auth_tok_list contains the set of authentication tokens |
1867 | * parsed from the metadata. We need to find a matching | |
1868 | * authentication token that has the secret component(s) | |
1869 | * necessary to decrypt the EFEK in the auth_tok parsed from | |
1870 | * the metadata. There may be several potential matches, but | |
1871 | * just one will be sufficient to decrypt to get the FEK. */ | |
1872 | find_next_matching_auth_tok: | |
1873 | found_auth_tok = 0; | |
1874 | list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) { | |
237fead6 MH |
1875 | candidate_auth_tok = &auth_tok_list_item->auth_tok; |
1876 | if (unlikely(ecryptfs_verbosity > 0)) { | |
1877 | ecryptfs_printk(KERN_DEBUG, | |
1878 | "Considering cadidate auth tok:\n"); | |
1879 | ecryptfs_dump_auth_tok(candidate_auth_tok); | |
1880 | } | |
5dda6992 MH |
1881 | rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig, |
1882 | candidate_auth_tok); | |
1883 | if (rc) { | |
f4aad16a MH |
1884 | printk(KERN_ERR |
1885 | "Unrecognized candidate auth tok type: [%d]\n", | |
1886 | candidate_auth_tok->token_type); | |
1887 | rc = -EINVAL; | |
1888 | goto out_wipe_list; | |
1889 | } | |
39fac853 | 1890 | rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key, |
aee683b9 | 1891 | &matching_auth_tok, |
9c79f34f | 1892 | crypt_stat->mount_crypt_stat, |
5dda6992 | 1893 | candidate_auth_tok_sig); |
39fac853 | 1894 | if (!rc) { |
dddfa461 | 1895 | found_auth_tok = 1; |
f4aad16a | 1896 | goto found_matching_auth_tok; |
237fead6 MH |
1897 | } |
1898 | } | |
237fead6 | 1899 | if (!found_auth_tok) { |
f4aad16a MH |
1900 | ecryptfs_printk(KERN_ERR, "Could not find a usable " |
1901 | "authentication token\n"); | |
237fead6 MH |
1902 | rc = -EIO; |
1903 | goto out_wipe_list; | |
dddfa461 | 1904 | } |
f4aad16a | 1905 | found_matching_auth_tok: |
e2bd99ec | 1906 | if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
dddfa461 | 1907 | memcpy(&(candidate_auth_tok->token.private_key), |
f4aad16a | 1908 | &(matching_auth_tok->token.private_key), |
dddfa461 | 1909 | sizeof(struct ecryptfs_private_key)); |
b2987a5e TH |
1910 | up_write(&(auth_tok_key->sem)); |
1911 | key_put(auth_tok_key); | |
f4aad16a | 1912 | rc = decrypt_pki_encrypted_session_key(candidate_auth_tok, |
dddfa461 MH |
1913 | crypt_stat); |
1914 | } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) { | |
237fead6 | 1915 | memcpy(&(candidate_auth_tok->token.password), |
f4aad16a | 1916 | &(matching_auth_tok->token.password), |
237fead6 | 1917 | sizeof(struct ecryptfs_password)); |
b2987a5e TH |
1918 | up_write(&(auth_tok_key->sem)); |
1919 | key_put(auth_tok_key); | |
f4aad16a MH |
1920 | rc = decrypt_passphrase_encrypted_session_key( |
1921 | candidate_auth_tok, crypt_stat); | |
b2987a5e TH |
1922 | } else { |
1923 | up_write(&(auth_tok_key->sem)); | |
1924 | key_put(auth_tok_key); | |
1925 | rc = -EINVAL; | |
dddfa461 MH |
1926 | } |
1927 | if (rc) { | |
f4aad16a MH |
1928 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
1929 | ||
1930 | ecryptfs_printk(KERN_WARNING, "Error decrypting the " | |
1931 | "session key for authentication token with sig " | |
1932 | "[%.*s]; rc = [%d]. Removing auth tok " | |
1933 | "candidate from the list and searching for " | |
888d57bb JP |
1934 | "the next match.\n", ECRYPTFS_SIG_SIZE_HEX, |
1935 | candidate_auth_tok_sig, rc); | |
f4aad16a MH |
1936 | list_for_each_entry_safe(auth_tok_list_item, |
1937 | auth_tok_list_item_tmp, | |
1938 | &auth_tok_list, list) { | |
1939 | if (candidate_auth_tok | |
1940 | == &auth_tok_list_item->auth_tok) { | |
1941 | list_del(&auth_tok_list_item->list); | |
1942 | kmem_cache_free( | |
1943 | ecryptfs_auth_tok_list_item_cache, | |
1944 | auth_tok_list_item); | |
1945 | goto find_next_matching_auth_tok; | |
1946 | } | |
1947 | } | |
1948 | BUG(); | |
dddfa461 MH |
1949 | } |
1950 | rc = ecryptfs_compute_root_iv(crypt_stat); | |
1951 | if (rc) { | |
1952 | ecryptfs_printk(KERN_ERR, "Error computing " | |
1953 | "the root IV\n"); | |
1954 | goto out_wipe_list; | |
237fead6 MH |
1955 | } |
1956 | rc = ecryptfs_init_crypt_ctx(crypt_stat); | |
1957 | if (rc) { | |
1958 | ecryptfs_printk(KERN_ERR, "Error initializing crypto " | |
1959 | "context for cipher [%s]; rc = [%d]\n", | |
1960 | crypt_stat->cipher, rc); | |
1961 | } | |
1962 | out_wipe_list: | |
1963 | wipe_auth_tok_list(&auth_tok_list); | |
1964 | out: | |
1965 | return rc; | |
1966 | } | |
f4aad16a | 1967 | |
dddfa461 | 1968 | static int |
b2987a5e TH |
1969 | pki_encrypt_session_key(struct key *auth_tok_key, |
1970 | struct ecryptfs_auth_tok *auth_tok, | |
dddfa461 MH |
1971 | struct ecryptfs_crypt_stat *crypt_stat, |
1972 | struct ecryptfs_key_record *key_rec) | |
1973 | { | |
1974 | struct ecryptfs_msg_ctx *msg_ctx = NULL; | |
624ae528 | 1975 | char *payload = NULL; |
99b373ff | 1976 | size_t payload_len = 0; |
dddfa461 MH |
1977 | struct ecryptfs_message *msg; |
1978 | int rc; | |
1979 | ||
1980 | rc = write_tag_66_packet(auth_tok->token.private_key.signature, | |
9c79f34f MH |
1981 | ecryptfs_code_for_cipher_string( |
1982 | crypt_stat->cipher, | |
1983 | crypt_stat->key_size), | |
624ae528 | 1984 | crypt_stat, &payload, &payload_len); |
b2987a5e TH |
1985 | up_write(&(auth_tok_key->sem)); |
1986 | key_put(auth_tok_key); | |
dddfa461 MH |
1987 | if (rc) { |
1988 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n"); | |
1989 | goto out; | |
1990 | } | |
624ae528 | 1991 | rc = ecryptfs_send_message(payload, payload_len, &msg_ctx); |
dddfa461 | 1992 | if (rc) { |
624ae528 TH |
1993 | ecryptfs_printk(KERN_ERR, "Error sending message to " |
1994 | "ecryptfsd\n"); | |
dddfa461 MH |
1995 | goto out; |
1996 | } | |
1997 | rc = ecryptfs_wait_for_response(msg_ctx, &msg); | |
1998 | if (rc) { | |
1999 | ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet " | |
2000 | "from the user space daemon\n"); | |
2001 | rc = -EIO; | |
2002 | goto out; | |
2003 | } | |
2004 | rc = parse_tag_67_packet(key_rec, msg); | |
2005 | if (rc) | |
2006 | ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n"); | |
2007 | kfree(msg); | |
2008 | out: | |
624ae528 | 2009 | kfree(payload); |
dddfa461 MH |
2010 | return rc; |
2011 | } | |
2012 | /** | |
2013 | * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet | |
2014 | * @dest: Buffer into which to write the packet | |
22e78faf | 2015 | * @remaining_bytes: Maximum number of bytes that can be writtn |
b2987a5e TH |
2016 | * @auth_tok_key: The authentication token key to unlock and put when done with |
2017 | * @auth_tok | |
22e78faf MH |
2018 | * @auth_tok: The authentication token used for generating the tag 1 packet |
2019 | * @crypt_stat: The cryptographic context | |
2020 | * @key_rec: The key record struct for the tag 1 packet | |
dddfa461 MH |
2021 | * @packet_size: This function will write the number of bytes that end |
2022 | * up constituting the packet; set to zero on error | |
2023 | * | |
2024 | * Returns zero on success; non-zero on error. | |
2025 | */ | |
2026 | static int | |
f4aad16a | 2027 | write_tag_1_packet(char *dest, size_t *remaining_bytes, |
b2987a5e | 2028 | struct key *auth_tok_key, struct ecryptfs_auth_tok *auth_tok, |
dddfa461 | 2029 | struct ecryptfs_crypt_stat *crypt_stat, |
dddfa461 MH |
2030 | struct ecryptfs_key_record *key_rec, size_t *packet_size) |
2031 | { | |
2032 | size_t i; | |
2033 | size_t encrypted_session_key_valid = 0; | |
dddfa461 | 2034 | size_t packet_size_length; |
f4aad16a | 2035 | size_t max_packet_size; |
dddfa461 MH |
2036 | int rc = 0; |
2037 | ||
2038 | (*packet_size) = 0; | |
2039 | ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature, | |
2040 | ECRYPTFS_SIG_SIZE); | |
2041 | encrypted_session_key_valid = 0; | |
2042 | for (i = 0; i < crypt_stat->key_size; i++) | |
2043 | encrypted_session_key_valid |= | |
2044 | auth_tok->session_key.encrypted_key[i]; | |
2045 | if (encrypted_session_key_valid) { | |
2046 | memcpy(key_rec->enc_key, | |
2047 | auth_tok->session_key.encrypted_key, | |
2048 | auth_tok->session_key.encrypted_key_size); | |
b2987a5e TH |
2049 | up_write(&(auth_tok_key->sem)); |
2050 | key_put(auth_tok_key); | |
dddfa461 MH |
2051 | goto encrypted_session_key_set; |
2052 | } | |
2053 | if (auth_tok->session_key.encrypted_key_size == 0) | |
2054 | auth_tok->session_key.encrypted_key_size = | |
2055 | auth_tok->token.private_key.key_size; | |
b2987a5e TH |
2056 | rc = pki_encrypt_session_key(auth_tok_key, auth_tok, crypt_stat, |
2057 | key_rec); | |
dddfa461 | 2058 | if (rc) { |
f66e883e MH |
2059 | printk(KERN_ERR "Failed to encrypt session key via a key " |
2060 | "module; rc = [%d]\n", rc); | |
dddfa461 MH |
2061 | goto out; |
2062 | } | |
2063 | if (ecryptfs_verbosity > 0) { | |
2064 | ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n"); | |
2065 | ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size); | |
2066 | } | |
2067 | encrypted_session_key_set: | |
f4aad16a MH |
2068 | /* This format is inspired by OpenPGP; see RFC 2440 |
2069 | * packet tag 1 */ | |
2070 | max_packet_size = (1 /* Tag 1 identifier */ | |
2071 | + 3 /* Max Tag 1 packet size */ | |
2072 | + 1 /* Version */ | |
2073 | + ECRYPTFS_SIG_SIZE /* Key identifier */ | |
2074 | + 1 /* Cipher identifier */ | |
2075 | + key_rec->enc_key_size); /* Encrypted key size */ | |
2076 | if (max_packet_size > (*remaining_bytes)) { | |
2077 | printk(KERN_ERR "Packet length larger than maximum allowable; " | |
81acbcd6 | 2078 | "need up to [%td] bytes, but there are only [%td] " |
f4aad16a | 2079 | "available\n", max_packet_size, (*remaining_bytes)); |
dddfa461 MH |
2080 | rc = -EINVAL; |
2081 | goto out; | |
2082 | } | |
2083 | dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE; | |
f66e883e MH |
2084 | rc = ecryptfs_write_packet_length(&dest[(*packet_size)], |
2085 | (max_packet_size - 4), | |
2086 | &packet_size_length); | |
dddfa461 MH |
2087 | if (rc) { |
2088 | ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet " | |
2089 | "header; cannot generate packet length\n"); | |
2090 | goto out; | |
2091 | } | |
2092 | (*packet_size) += packet_size_length; | |
2093 | dest[(*packet_size)++] = 0x03; /* version 3 */ | |
2094 | memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE); | |
2095 | (*packet_size) += ECRYPTFS_SIG_SIZE; | |
2096 | dest[(*packet_size)++] = RFC2440_CIPHER_RSA; | |
2097 | memcpy(&dest[(*packet_size)], key_rec->enc_key, | |
2098 | key_rec->enc_key_size); | |
2099 | (*packet_size) += key_rec->enc_key_size; | |
2100 | out: | |
2101 | if (rc) | |
2102 | (*packet_size) = 0; | |
f4aad16a MH |
2103 | else |
2104 | (*remaining_bytes) -= (*packet_size); | |
dddfa461 MH |
2105 | return rc; |
2106 | } | |
237fead6 MH |
2107 | |
2108 | /** | |
2109 | * write_tag_11_packet | |
2110 | * @dest: Target into which Tag 11 packet is to be written | |
22e78faf | 2111 | * @remaining_bytes: Maximum packet length |
237fead6 MH |
2112 | * @contents: Byte array of contents to copy in |
2113 | * @contents_length: Number of bytes in contents | |
2114 | * @packet_length: Length of the Tag 11 packet written; zero on error | |
2115 | * | |
2116 | * Returns zero on success; non-zero on error. | |
2117 | */ | |
2118 | static int | |
81acbcd6 | 2119 | write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents, |
146a4606 | 2120 | size_t contents_length, size_t *packet_length) |
237fead6 | 2121 | { |
237fead6 | 2122 | size_t packet_size_length; |
146a4606 | 2123 | size_t max_packet_size; |
dddfa461 | 2124 | int rc = 0; |
237fead6 MH |
2125 | |
2126 | (*packet_length) = 0; | |
146a4606 MH |
2127 | /* This format is inspired by OpenPGP; see RFC 2440 |
2128 | * packet tag 11 */ | |
2129 | max_packet_size = (1 /* Tag 11 identifier */ | |
2130 | + 3 /* Max Tag 11 packet size */ | |
2131 | + 1 /* Binary format specifier */ | |
2132 | + 1 /* Filename length */ | |
2133 | + 8 /* Filename ("_CONSOLE") */ | |
2134 | + 4 /* Modification date */ | |
2135 | + contents_length); /* Literal data */ | |
2136 | if (max_packet_size > (*remaining_bytes)) { | |
2137 | printk(KERN_ERR "Packet length larger than maximum allowable; " | |
81acbcd6 | 2138 | "need up to [%td] bytes, but there are only [%td] " |
146a4606 | 2139 | "available\n", max_packet_size, (*remaining_bytes)); |
237fead6 | 2140 | rc = -EINVAL; |
237fead6 MH |
2141 | goto out; |
2142 | } | |
237fead6 | 2143 | dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE; |
f66e883e MH |
2144 | rc = ecryptfs_write_packet_length(&dest[(*packet_length)], |
2145 | (max_packet_size - 4), | |
2146 | &packet_size_length); | |
237fead6 | 2147 | if (rc) { |
146a4606 MH |
2148 | printk(KERN_ERR "Error generating tag 11 packet header; cannot " |
2149 | "generate packet length. rc = [%d]\n", rc); | |
237fead6 MH |
2150 | goto out; |
2151 | } | |
2152 | (*packet_length) += packet_size_length; | |
146a4606 | 2153 | dest[(*packet_length)++] = 0x62; /* binary data format specifier */ |
237fead6 MH |
2154 | dest[(*packet_length)++] = 8; |
2155 | memcpy(&dest[(*packet_length)], "_CONSOLE", 8); | |
2156 | (*packet_length) += 8; | |
237fead6 MH |
2157 | memset(&dest[(*packet_length)], 0x00, 4); |
2158 | (*packet_length) += 4; | |
237fead6 MH |
2159 | memcpy(&dest[(*packet_length)], contents, contents_length); |
2160 | (*packet_length) += contents_length; | |
2161 | out: | |
2162 | if (rc) | |
2163 | (*packet_length) = 0; | |
146a4606 MH |
2164 | else |
2165 | (*remaining_bytes) -= (*packet_length); | |
237fead6 MH |
2166 | return rc; |
2167 | } | |
2168 | ||
2169 | /** | |
2170 | * write_tag_3_packet | |
2171 | * @dest: Buffer into which to write the packet | |
22e78faf | 2172 | * @remaining_bytes: Maximum number of bytes that can be written |
237fead6 MH |
2173 | * @auth_tok: Authentication token |
2174 | * @crypt_stat: The cryptographic context | |
2175 | * @key_rec: encrypted key | |
2176 | * @packet_size: This function will write the number of bytes that end | |
2177 | * up constituting the packet; set to zero on error | |
2178 | * | |
2179 | * Returns zero on success; non-zero on error. | |
2180 | */ | |
2181 | static int | |
f4aad16a MH |
2182 | write_tag_3_packet(char *dest, size_t *remaining_bytes, |
2183 | struct ecryptfs_auth_tok *auth_tok, | |
237fead6 MH |
2184 | struct ecryptfs_crypt_stat *crypt_stat, |
2185 | struct ecryptfs_key_record *key_rec, size_t *packet_size) | |
2186 | { | |
237fead6 | 2187 | size_t i; |
237fead6 MH |
2188 | size_t encrypted_session_key_valid = 0; |
2189 | char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES]; | |
ac97b9f9 MH |
2190 | struct scatterlist dst_sg[2]; |
2191 | struct scatterlist src_sg[2]; | |
237fead6 | 2192 | struct mutex *tfm_mutex = NULL; |
19e66a67 | 2193 | u8 cipher_code; |
f4aad16a MH |
2194 | size_t packet_size_length; |
2195 | size_t max_packet_size; | |
2196 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = | |
2197 | crypt_stat->mount_crypt_stat; | |
8bba066f MH |
2198 | struct blkcipher_desc desc = { |
2199 | .tfm = NULL, | |
2200 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
2201 | }; | |
2202 | int rc = 0; | |
237fead6 MH |
2203 | |
2204 | (*packet_size) = 0; | |
dddfa461 | 2205 | ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature, |
237fead6 | 2206 | ECRYPTFS_SIG_SIZE); |
f4aad16a MH |
2207 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex, |
2208 | crypt_stat->cipher); | |
2209 | if (unlikely(rc)) { | |
2210 | printk(KERN_ERR "Internal error whilst attempting to get " | |
2211 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
2212 | crypt_stat->cipher, rc); | |
2213 | goto out; | |
2214 | } | |
2215 | if (mount_crypt_stat->global_default_cipher_key_size == 0) { | |
2216 | struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm); | |
2217 | ||
2218 | printk(KERN_WARNING "No key size specified at mount; " | |
2219 | "defaulting to [%d]\n", alg->max_keysize); | |
2220 | mount_crypt_stat->global_default_cipher_key_size = | |
2221 | alg->max_keysize; | |
237fead6 | 2222 | } |
f4aad16a MH |
2223 | if (crypt_stat->key_size == 0) |
2224 | crypt_stat->key_size = | |
2225 | mount_crypt_stat->global_default_cipher_key_size; | |
237fead6 MH |
2226 | if (auth_tok->session_key.encrypted_key_size == 0) |
2227 | auth_tok->session_key.encrypted_key_size = | |
2228 | crypt_stat->key_size; | |
2229 | if (crypt_stat->key_size == 24 | |
2230 | && strcmp("aes", crypt_stat->cipher) == 0) { | |
2231 | memset((crypt_stat->key + 24), 0, 8); | |
2232 | auth_tok->session_key.encrypted_key_size = 32; | |
f4aad16a MH |
2233 | } else |
2234 | auth_tok->session_key.encrypted_key_size = crypt_stat->key_size; | |
dddfa461 | 2235 | key_rec->enc_key_size = |
237fead6 | 2236 | auth_tok->session_key.encrypted_key_size; |
f4aad16a MH |
2237 | encrypted_session_key_valid = 0; |
2238 | for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++) | |
2239 | encrypted_session_key_valid |= | |
2240 | auth_tok->session_key.encrypted_key[i]; | |
2241 | if (encrypted_session_key_valid) { | |
2242 | ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; " | |
2243 | "using auth_tok->session_key.encrypted_key, " | |
f24b3887 | 2244 | "where key_rec->enc_key_size = [%zd]\n", |
f4aad16a MH |
2245 | key_rec->enc_key_size); |
2246 | memcpy(key_rec->enc_key, | |
2247 | auth_tok->session_key.encrypted_key, | |
2248 | key_rec->enc_key_size); | |
2249 | goto encrypted_session_key_set; | |
2250 | } | |
dddfa461 MH |
2251 | if (auth_tok->token.password.flags & |
2252 | ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) { | |
237fead6 MH |
2253 | ecryptfs_printk(KERN_DEBUG, "Using previously generated " |
2254 | "session key encryption key of size [%d]\n", | |
2255 | auth_tok->token.password. | |
2256 | session_key_encryption_key_bytes); | |
2257 | memcpy(session_key_encryption_key, | |
2258 | auth_tok->token.password.session_key_encryption_key, | |
2259 | crypt_stat->key_size); | |
2260 | ecryptfs_printk(KERN_DEBUG, | |
df2e301f | 2261 | "Cached session key encryption key:\n"); |
237fead6 MH |
2262 | if (ecryptfs_verbosity > 0) |
2263 | ecryptfs_dump_hex(session_key_encryption_key, 16); | |
2264 | } | |
2265 | if (unlikely(ecryptfs_verbosity > 0)) { | |
2266 | ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n"); | |
2267 | ecryptfs_dump_hex(session_key_encryption_key, 16); | |
2268 | } | |
5dda6992 | 2269 | rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size, |
ac97b9f9 MH |
2270 | src_sg, 2); |
2271 | if (rc < 1 || rc > 2) { | |
237fead6 | 2272 | ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
f4aad16a | 2273 | "for crypt_stat session key; expected rc = 1; " |
f24b3887 | 2274 | "got rc = [%d]. key_rec->enc_key_size = [%zd]\n", |
f4aad16a | 2275 | rc, key_rec->enc_key_size); |
237fead6 MH |
2276 | rc = -ENOMEM; |
2277 | goto out; | |
2278 | } | |
5dda6992 | 2279 | rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size, |
ac97b9f9 MH |
2280 | dst_sg, 2); |
2281 | if (rc < 1 || rc > 2) { | |
237fead6 | 2282 | ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
f4aad16a MH |
2283 | "for crypt_stat encrypted session key; " |
2284 | "expected rc = 1; got rc = [%d]. " | |
f24b3887 | 2285 | "key_rec->enc_key_size = [%zd]\n", rc, |
f4aad16a | 2286 | key_rec->enc_key_size); |
237fead6 MH |
2287 | rc = -ENOMEM; |
2288 | goto out; | |
2289 | } | |
f4aad16a | 2290 | mutex_lock(tfm_mutex); |
8bba066f MH |
2291 | rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key, |
2292 | crypt_stat->key_size); | |
237fead6 | 2293 | if (rc < 0) { |
f4aad16a | 2294 | mutex_unlock(tfm_mutex); |
237fead6 | 2295 | ecryptfs_printk(KERN_ERR, "Error setting key for crypto " |
8bba066f | 2296 | "context; rc = [%d]\n", rc); |
237fead6 MH |
2297 | goto out; |
2298 | } | |
2299 | rc = 0; | |
f24b3887 | 2300 | ecryptfs_printk(KERN_DEBUG, "Encrypting [%zd] bytes of the key\n", |
237fead6 | 2301 | crypt_stat->key_size); |
ac97b9f9 | 2302 | rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg, |
8bba066f | 2303 | (*key_rec).enc_key_size); |
f4aad16a | 2304 | mutex_unlock(tfm_mutex); |
8bba066f MH |
2305 | if (rc) { |
2306 | printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc); | |
2307 | goto out; | |
2308 | } | |
237fead6 | 2309 | ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n"); |
f4aad16a | 2310 | if (ecryptfs_verbosity > 0) { |
f24b3887 | 2311 | ecryptfs_printk(KERN_DEBUG, "EFEK of size [%zd]:\n", |
f4aad16a | 2312 | key_rec->enc_key_size); |
dddfa461 MH |
2313 | ecryptfs_dump_hex(key_rec->enc_key, |
2314 | key_rec->enc_key_size); | |
237fead6 | 2315 | } |
f4aad16a MH |
2316 | encrypted_session_key_set: |
2317 | /* This format is inspired by OpenPGP; see RFC 2440 | |
2318 | * packet tag 3 */ | |
2319 | max_packet_size = (1 /* Tag 3 identifier */ | |
2320 | + 3 /* Max Tag 3 packet size */ | |
2321 | + 1 /* Version */ | |
2322 | + 1 /* Cipher code */ | |
2323 | + 1 /* S2K specifier */ | |
2324 | + 1 /* Hash identifier */ | |
2325 | + ECRYPTFS_SALT_SIZE /* Salt */ | |
2326 | + 1 /* Hash iterations */ | |
2327 | + key_rec->enc_key_size); /* Encrypted key size */ | |
2328 | if (max_packet_size > (*remaining_bytes)) { | |
81acbcd6 AM |
2329 | printk(KERN_ERR "Packet too large; need up to [%td] bytes, but " |
2330 | "there are only [%td] available\n", max_packet_size, | |
f4aad16a | 2331 | (*remaining_bytes)); |
237fead6 MH |
2332 | rc = -EINVAL; |
2333 | goto out; | |
2334 | } | |
237fead6 | 2335 | dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE; |
f4aad16a MH |
2336 | /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3) |
2337 | * to get the number of octets in the actual Tag 3 packet */ | |
f66e883e MH |
2338 | rc = ecryptfs_write_packet_length(&dest[(*packet_size)], |
2339 | (max_packet_size - 4), | |
2340 | &packet_size_length); | |
237fead6 | 2341 | if (rc) { |
f4aad16a MH |
2342 | printk(KERN_ERR "Error generating tag 3 packet header; cannot " |
2343 | "generate packet length. rc = [%d]\n", rc); | |
237fead6 MH |
2344 | goto out; |
2345 | } | |
2346 | (*packet_size) += packet_size_length; | |
2347 | dest[(*packet_size)++] = 0x04; /* version 4 */ | |
f4aad16a MH |
2348 | /* TODO: Break from RFC2440 so that arbitrary ciphers can be |
2349 | * specified with strings */ | |
9c79f34f MH |
2350 | cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher, |
2351 | crypt_stat->key_size); | |
237fead6 MH |
2352 | if (cipher_code == 0) { |
2353 | ecryptfs_printk(KERN_WARNING, "Unable to generate code for " | |
2354 | "cipher [%s]\n", crypt_stat->cipher); | |
2355 | rc = -EINVAL; | |
2356 | goto out; | |
2357 | } | |
2358 | dest[(*packet_size)++] = cipher_code; | |
2359 | dest[(*packet_size)++] = 0x03; /* S2K */ | |
2360 | dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */ | |
2361 | memcpy(&dest[(*packet_size)], auth_tok->token.password.salt, | |
2362 | ECRYPTFS_SALT_SIZE); | |
2363 | (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */ | |
2364 | dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */ | |
dddfa461 MH |
2365 | memcpy(&dest[(*packet_size)], key_rec->enc_key, |
2366 | key_rec->enc_key_size); | |
2367 | (*packet_size) += key_rec->enc_key_size; | |
237fead6 | 2368 | out: |
237fead6 MH |
2369 | if (rc) |
2370 | (*packet_size) = 0; | |
f4aad16a MH |
2371 | else |
2372 | (*remaining_bytes) -= (*packet_size); | |
237fead6 MH |
2373 | return rc; |
2374 | } | |
2375 | ||
eb95e7ff MH |
2376 | struct kmem_cache *ecryptfs_key_record_cache; |
2377 | ||
237fead6 MH |
2378 | /** |
2379 | * ecryptfs_generate_key_packet_set | |
22e78faf | 2380 | * @dest_base: Virtual address from which to write the key record set |
237fead6 MH |
2381 | * @crypt_stat: The cryptographic context from which the |
2382 | * authentication tokens will be retrieved | |
2383 | * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat | |
2384 | * for the global parameters | |
2385 | * @len: The amount written | |
2386 | * @max: The maximum amount of data allowed to be written | |
2387 | * | |
2388 | * Generates a key packet set and writes it to the virtual address | |
2389 | * passed in. | |
2390 | * | |
2391 | * Returns zero on success; non-zero on error. | |
2392 | */ | |
2393 | int | |
2394 | ecryptfs_generate_key_packet_set(char *dest_base, | |
2395 | struct ecryptfs_crypt_stat *crypt_stat, | |
2396 | struct dentry *ecryptfs_dentry, size_t *len, | |
2397 | size_t max) | |
2398 | { | |
237fead6 | 2399 | struct ecryptfs_auth_tok *auth_tok; |
0e1fc5ef | 2400 | struct key *auth_tok_key = NULL; |
237fead6 MH |
2401 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
2402 | &ecryptfs_superblock_to_private( | |
2403 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
2404 | size_t written; | |
eb95e7ff | 2405 | struct ecryptfs_key_record *key_rec; |
f4aad16a | 2406 | struct ecryptfs_key_sig *key_sig; |
dddfa461 | 2407 | int rc = 0; |
237fead6 MH |
2408 | |
2409 | (*len) = 0; | |
f4aad16a | 2410 | mutex_lock(&crypt_stat->keysig_list_mutex); |
eb95e7ff MH |
2411 | key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL); |
2412 | if (!key_rec) { | |
2413 | rc = -ENOMEM; | |
2414 | goto out; | |
2415 | } | |
f4aad16a MH |
2416 | list_for_each_entry(key_sig, &crypt_stat->keysig_list, |
2417 | crypt_stat_list) { | |
2418 | memset(key_rec, 0, sizeof(*key_rec)); | |
0e1fc5ef RS |
2419 | rc = ecryptfs_find_global_auth_tok_for_sig(&auth_tok_key, |
2420 | &auth_tok, | |
f4aad16a MH |
2421 | mount_crypt_stat, |
2422 | key_sig->keysig); | |
2423 | if (rc) { | |
0e1fc5ef RS |
2424 | printk(KERN_WARNING "Unable to retrieve auth tok with " |
2425 | "sig = [%s]\n", key_sig->keysig); | |
2426 | rc = process_find_global_auth_tok_for_sig_err(rc); | |
f4aad16a MH |
2427 | goto out_free; |
2428 | } | |
237fead6 MH |
2429 | if (auth_tok->token_type == ECRYPTFS_PASSWORD) { |
2430 | rc = write_tag_3_packet((dest_base + (*len)), | |
f4aad16a | 2431 | &max, auth_tok, |
eb95e7ff | 2432 | crypt_stat, key_rec, |
237fead6 | 2433 | &written); |
b2987a5e TH |
2434 | up_write(&(auth_tok_key->sem)); |
2435 | key_put(auth_tok_key); | |
237fead6 MH |
2436 | if (rc) { |
2437 | ecryptfs_printk(KERN_WARNING, "Error " | |
2438 | "writing tag 3 packet\n"); | |
eb95e7ff | 2439 | goto out_free; |
237fead6 MH |
2440 | } |
2441 | (*len) += written; | |
2442 | /* Write auth tok signature packet */ | |
f4aad16a MH |
2443 | rc = write_tag_11_packet((dest_base + (*len)), &max, |
2444 | key_rec->sig, | |
2445 | ECRYPTFS_SIG_SIZE, &written); | |
237fead6 MH |
2446 | if (rc) { |
2447 | ecryptfs_printk(KERN_ERR, "Error writing " | |
2448 | "auth tok signature packet\n"); | |
eb95e7ff | 2449 | goto out_free; |
237fead6 MH |
2450 | } |
2451 | (*len) += written; | |
dddfa461 | 2452 | } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
b2987a5e TH |
2453 | rc = write_tag_1_packet(dest_base + (*len), &max, |
2454 | auth_tok_key, auth_tok, | |
f4aad16a | 2455 | crypt_stat, key_rec, &written); |
dddfa461 MH |
2456 | if (rc) { |
2457 | ecryptfs_printk(KERN_WARNING, "Error " | |
2458 | "writing tag 1 packet\n"); | |
eb95e7ff | 2459 | goto out_free; |
dddfa461 MH |
2460 | } |
2461 | (*len) += written; | |
237fead6 | 2462 | } else { |
b2987a5e TH |
2463 | up_write(&(auth_tok_key->sem)); |
2464 | key_put(auth_tok_key); | |
237fead6 MH |
2465 | ecryptfs_printk(KERN_WARNING, "Unsupported " |
2466 | "authentication token type\n"); | |
2467 | rc = -EINVAL; | |
eb95e7ff | 2468 | goto out_free; |
237fead6 | 2469 | } |
f4aad16a MH |
2470 | } |
2471 | if (likely(max > 0)) { | |
237fead6 MH |
2472 | dest_base[(*len)] = 0x00; |
2473 | } else { | |
2474 | ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n"); | |
2475 | rc = -EIO; | |
2476 | } | |
eb95e7ff MH |
2477 | out_free: |
2478 | kmem_cache_free(ecryptfs_key_record_cache, key_rec); | |
237fead6 MH |
2479 | out: |
2480 | if (rc) | |
2481 | (*len) = 0; | |
f4aad16a MH |
2482 | mutex_unlock(&crypt_stat->keysig_list_mutex); |
2483 | return rc; | |
2484 | } | |
2485 | ||
2486 | struct kmem_cache *ecryptfs_key_sig_cache; | |
2487 | ||
2488 | int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig) | |
2489 | { | |
2490 | struct ecryptfs_key_sig *new_key_sig; | |
f4aad16a MH |
2491 | |
2492 | new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL); | |
2493 | if (!new_key_sig) { | |
f4aad16a MH |
2494 | printk(KERN_ERR |
2495 | "Error allocating from ecryptfs_key_sig_cache\n"); | |
aa06117f | 2496 | return -ENOMEM; |
f4aad16a MH |
2497 | } |
2498 | memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX); | |
7762e230 | 2499 | new_key_sig->keysig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
aa06117f | 2500 | /* Caller must hold keysig_list_mutex */ |
f4aad16a | 2501 | list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list); |
aa06117f RD |
2502 | |
2503 | return 0; | |
237fead6 | 2504 | } |
f4aad16a MH |
2505 | |
2506 | struct kmem_cache *ecryptfs_global_auth_tok_cache; | |
2507 | ||
2508 | int | |
2509 | ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
84814d64 | 2510 | char *sig, u32 global_auth_tok_flags) |
f4aad16a MH |
2511 | { |
2512 | struct ecryptfs_global_auth_tok *new_auth_tok; | |
2513 | int rc = 0; | |
2514 | ||
459e2164 | 2515 | new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache, |
f4aad16a MH |
2516 | GFP_KERNEL); |
2517 | if (!new_auth_tok) { | |
2518 | rc = -ENOMEM; | |
2519 | printk(KERN_ERR "Error allocating from " | |
2520 | "ecryptfs_global_auth_tok_cache\n"); | |
2521 | goto out; | |
2522 | } | |
2523 | memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX); | |
84814d64 | 2524 | new_auth_tok->flags = global_auth_tok_flags; |
f4aad16a MH |
2525 | new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
2526 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
2527 | list_add(&new_auth_tok->mount_crypt_stat_list, | |
2528 | &mount_crypt_stat->global_auth_tok_list); | |
f4aad16a MH |
2529 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); |
2530 | out: | |
2531 | return rc; | |
2532 | } | |
2533 |