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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/pagemap.h> |
30 | #include <linux/key.h> | |
31 | #include <linux/random.h> | |
32 | #include <linux/crypto.h> | |
33 | #include <linux/scatterlist.h> | |
5a0e3ad6 | 34 | #include <linux/slab.h> |
237fead6 MH |
35 | #include "ecryptfs_kernel.h" |
36 | ||
37 | /** | |
38 | * request_key returned an error instead of a valid key address; | |
39 | * determine the type of error, make appropriate log entries, and | |
40 | * return an error code. | |
41 | */ | |
cd9d67df | 42 | static int process_request_key_err(long err_code) |
237fead6 MH |
43 | { |
44 | int rc = 0; | |
45 | ||
46 | switch (err_code) { | |
982363c9 | 47 | case -ENOKEY: |
237fead6 MH |
48 | ecryptfs_printk(KERN_WARNING, "No key\n"); |
49 | rc = -ENOENT; | |
50 | break; | |
982363c9 | 51 | case -EKEYEXPIRED: |
237fead6 MH |
52 | ecryptfs_printk(KERN_WARNING, "Key expired\n"); |
53 | rc = -ETIME; | |
54 | break; | |
982363c9 | 55 | case -EKEYREVOKED: |
237fead6 MH |
56 | ecryptfs_printk(KERN_WARNING, "Key revoked\n"); |
57 | rc = -EINVAL; | |
58 | break; | |
59 | default: | |
60 | ecryptfs_printk(KERN_WARNING, "Unknown error code: " | |
888d57bb | 61 | "[0x%.16lx]\n", err_code); |
237fead6 MH |
62 | rc = -EINVAL; |
63 | } | |
64 | return rc; | |
65 | } | |
66 | ||
0e1fc5ef RS |
67 | static int process_find_global_auth_tok_for_sig_err(int err_code) |
68 | { | |
69 | int rc = err_code; | |
70 | ||
71 | switch (err_code) { | |
72 | case -ENOENT: | |
73 | ecryptfs_printk(KERN_WARNING, "Missing auth tok\n"); | |
74 | break; | |
75 | case -EINVAL: | |
76 | ecryptfs_printk(KERN_WARNING, "Invalid auth tok\n"); | |
77 | break; | |
78 | default: | |
79 | rc = process_request_key_err(err_code); | |
80 | break; | |
81 | } | |
82 | return rc; | |
83 | } | |
84 | ||
237fead6 | 85 | /** |
f66e883e | 86 | * ecryptfs_parse_packet_length |
237fead6 MH |
87 | * @data: Pointer to memory containing length at offset |
88 | * @size: This function writes the decoded size to this memory | |
89 | * address; zero on error | |
90 | * @length_size: The number of bytes occupied by the encoded length | |
91 | * | |
22e78faf | 92 | * Returns zero on success; non-zero on error |
237fead6 | 93 | */ |
f66e883e MH |
94 | int ecryptfs_parse_packet_length(unsigned char *data, size_t *size, |
95 | size_t *length_size) | |
237fead6 MH |
96 | { |
97 | int rc = 0; | |
98 | ||
99 | (*length_size) = 0; | |
100 | (*size) = 0; | |
101 | if (data[0] < 192) { | |
102 | /* One-byte length */ | |
831115af | 103 | (*size) = data[0]; |
237fead6 MH |
104 | (*length_size) = 1; |
105 | } else if (data[0] < 224) { | |
106 | /* Two-byte length */ | |
831115af TH |
107 | (*size) = (data[0] - 192) * 256; |
108 | (*size) += data[1] + 192; | |
237fead6 MH |
109 | (*length_size) = 2; |
110 | } else if (data[0] == 255) { | |
48399c0b | 111 | /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */ |
237fead6 MH |
112 | ecryptfs_printk(KERN_ERR, "Five-byte packet length not " |
113 | "supported\n"); | |
114 | rc = -EINVAL; | |
115 | goto out; | |
116 | } else { | |
117 | ecryptfs_printk(KERN_ERR, "Error parsing packet length\n"); | |
118 | rc = -EINVAL; | |
119 | goto out; | |
120 | } | |
121 | out: | |
122 | return rc; | |
123 | } | |
124 | ||
125 | /** | |
f66e883e | 126 | * ecryptfs_write_packet_length |
22e78faf | 127 | * @dest: The byte array target into which to write the length. Must |
48399c0b | 128 | * have at least ECRYPTFS_MAX_PKT_LEN_SIZE bytes allocated. |
237fead6 | 129 | * @size: The length to write. |
22e78faf MH |
130 | * @packet_size_length: The number of bytes used to encode the packet |
131 | * length is written to this address. | |
237fead6 MH |
132 | * |
133 | * Returns zero on success; non-zero on error. | |
134 | */ | |
f66e883e MH |
135 | int ecryptfs_write_packet_length(char *dest, size_t size, |
136 | size_t *packet_size_length) | |
237fead6 MH |
137 | { |
138 | int rc = 0; | |
139 | ||
140 | if (size < 192) { | |
141 | dest[0] = size; | |
142 | (*packet_size_length) = 1; | |
143 | } else if (size < 65536) { | |
144 | dest[0] = (((size - 192) / 256) + 192); | |
145 | dest[1] = ((size - 192) % 256); | |
146 | (*packet_size_length) = 2; | |
147 | } else { | |
48399c0b | 148 | /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */ |
237fead6 MH |
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 */ | |
4a26620d | 681 | s->max_packet_size = (ECRYPTFS_TAG_70_MAX_METADATA_SIZE |
9c79f34f MH |
682 | + s->block_aligned_filename_size); |
683 | if (dest == NULL) { | |
684 | (*packet_size) = s->max_packet_size; | |
685 | goto out_unlock; | |
686 | } | |
687 | if (s->max_packet_size > (*remaining_bytes)) { | |
a8f12864 MH |
688 | printk(KERN_WARNING "%s: Require [%zd] bytes to write; only " |
689 | "[%zd] available\n", __func__, s->max_packet_size, | |
9c79f34f MH |
690 | (*remaining_bytes)); |
691 | rc = -EINVAL; | |
692 | goto out_unlock; | |
693 | } | |
694 | s->block_aligned_filename = kzalloc(s->block_aligned_filename_size, | |
695 | GFP_KERNEL); | |
696 | if (!s->block_aligned_filename) { | |
697 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " | |
df261c52 | 698 | "kzalloc [%zd] bytes\n", __func__, |
9c79f34f MH |
699 | s->block_aligned_filename_size); |
700 | rc = -ENOMEM; | |
701 | goto out_unlock; | |
702 | } | |
703 | s->i = 0; | |
704 | dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE; | |
705 | rc = ecryptfs_write_packet_length(&dest[s->i], | |
706 | (ECRYPTFS_SIG_SIZE | |
707 | + 1 /* Cipher code */ | |
708 | + s->block_aligned_filename_size), | |
709 | &s->packet_size_len); | |
710 | if (rc) { | |
711 | printk(KERN_ERR "%s: Error generating tag 70 packet " | |
712 | "header; cannot generate packet length; rc = [%d]\n", | |
713 | __func__, rc); | |
714 | goto out_free_unlock; | |
715 | } | |
716 | s->i += s->packet_size_len; | |
717 | ecryptfs_from_hex(&dest[s->i], | |
718 | mount_crypt_stat->global_default_fnek_sig, | |
719 | ECRYPTFS_SIG_SIZE); | |
720 | s->i += ECRYPTFS_SIG_SIZE; | |
721 | s->cipher_code = ecryptfs_code_for_cipher_string( | |
722 | mount_crypt_stat->global_default_fn_cipher_name, | |
723 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
724 | if (s->cipher_code == 0) { | |
725 | printk(KERN_WARNING "%s: Unable to generate code for " | |
a8f12864 | 726 | "cipher [%s] with key bytes [%zd]\n", __func__, |
9c79f34f MH |
727 | mount_crypt_stat->global_default_fn_cipher_name, |
728 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
729 | rc = -EINVAL; | |
730 | goto out_free_unlock; | |
731 | } | |
732 | dest[s->i++] = s->cipher_code; | |
9c79f34f MH |
733 | /* TODO: Support other key modules than passphrase for |
734 | * filename encryption */ | |
df6ad33b TH |
735 | if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) { |
736 | rc = -EOPNOTSUPP; | |
737 | printk(KERN_INFO "%s: Filename encryption only supports " | |
738 | "password tokens\n", __func__); | |
739 | goto out_free_unlock; | |
740 | } | |
9c79f34f MH |
741 | sg_init_one( |
742 | &s->hash_sg, | |
743 | (u8 *)s->auth_tok->token.password.session_key_encryption_key, | |
744 | s->auth_tok->token.password.session_key_encryption_key_bytes); | |
745 | s->hash_desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; | |
746 | s->hash_desc.tfm = crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST, 0, | |
747 | CRYPTO_ALG_ASYNC); | |
748 | if (IS_ERR(s->hash_desc.tfm)) { | |
749 | rc = PTR_ERR(s->hash_desc.tfm); | |
750 | printk(KERN_ERR "%s: Error attempting to " | |
751 | "allocate hash crypto context; rc = [%d]\n", | |
752 | __func__, rc); | |
753 | goto out_free_unlock; | |
754 | } | |
755 | rc = crypto_hash_init(&s->hash_desc); | |
756 | if (rc) { | |
757 | printk(KERN_ERR | |
758 | "%s: Error initializing crypto hash; rc = [%d]\n", | |
759 | __func__, rc); | |
760 | goto out_release_free_unlock; | |
761 | } | |
762 | rc = crypto_hash_update( | |
763 | &s->hash_desc, &s->hash_sg, | |
764 | s->auth_tok->token.password.session_key_encryption_key_bytes); | |
765 | if (rc) { | |
766 | printk(KERN_ERR | |
767 | "%s: Error updating crypto hash; rc = [%d]\n", | |
768 | __func__, rc); | |
769 | goto out_release_free_unlock; | |
770 | } | |
771 | rc = crypto_hash_final(&s->hash_desc, s->hash); | |
772 | if (rc) { | |
773 | printk(KERN_ERR | |
774 | "%s: Error finalizing crypto hash; rc = [%d]\n", | |
775 | __func__, rc); | |
776 | goto out_release_free_unlock; | |
777 | } | |
778 | for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) { | |
779 | s->block_aligned_filename[s->j] = | |
780 | s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)]; | |
781 | if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE) | |
782 | == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) { | |
783 | sg_init_one(&s->hash_sg, (u8 *)s->hash, | |
784 | ECRYPTFS_TAG_70_DIGEST_SIZE); | |
785 | rc = crypto_hash_init(&s->hash_desc); | |
786 | if (rc) { | |
787 | printk(KERN_ERR | |
788 | "%s: Error initializing crypto hash; " | |
789 | "rc = [%d]\n", __func__, rc); | |
790 | goto out_release_free_unlock; | |
791 | } | |
792 | rc = crypto_hash_update(&s->hash_desc, &s->hash_sg, | |
793 | ECRYPTFS_TAG_70_DIGEST_SIZE); | |
794 | if (rc) { | |
795 | printk(KERN_ERR | |
796 | "%s: Error updating crypto hash; " | |
797 | "rc = [%d]\n", __func__, rc); | |
798 | goto out_release_free_unlock; | |
799 | } | |
800 | rc = crypto_hash_final(&s->hash_desc, s->tmp_hash); | |
801 | if (rc) { | |
802 | printk(KERN_ERR | |
803 | "%s: Error finalizing crypto hash; " | |
804 | "rc = [%d]\n", __func__, rc); | |
805 | goto out_release_free_unlock; | |
806 | } | |
807 | memcpy(s->hash, s->tmp_hash, | |
808 | ECRYPTFS_TAG_70_DIGEST_SIZE); | |
809 | } | |
810 | if (s->block_aligned_filename[s->j] == '\0') | |
811 | s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL; | |
812 | } | |
813 | memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename, | |
814 | filename_size); | |
815 | rc = virt_to_scatterlist(s->block_aligned_filename, | |
8d08dab7 TH |
816 | s->block_aligned_filename_size, s->src_sg, 2); |
817 | if (rc < 1) { | |
9c79f34f | 818 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
8d08dab7 | 819 | "convert filename memory to scatterlist; rc = [%d]. " |
a8f12864 | 820 | "block_aligned_filename_size = [%zd]\n", __func__, rc, |
9c79f34f MH |
821 | s->block_aligned_filename_size); |
822 | goto out_release_free_unlock; | |
823 | } | |
824 | rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size, | |
8d08dab7 TH |
825 | s->dst_sg, 2); |
826 | if (rc < 1) { | |
9c79f34f MH |
827 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
828 | "convert encrypted filename memory to scatterlist; " | |
8d08dab7 TH |
829 | "rc = [%d]. block_aligned_filename_size = [%zd]\n", |
830 | __func__, rc, s->block_aligned_filename_size); | |
9c79f34f MH |
831 | goto out_release_free_unlock; |
832 | } | |
833 | /* The characters in the first block effectively do the job | |
834 | * of the IV here, so we just use 0's for the IV. Note the | |
835 | * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES | |
836 | * >= ECRYPTFS_MAX_IV_BYTES. */ | |
837 | memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES); | |
838 | s->desc.info = s->iv; | |
839 | rc = crypto_blkcipher_setkey( | |
840 | s->desc.tfm, | |
841 | s->auth_tok->token.password.session_key_encryption_key, | |
842 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
843 | if (rc < 0) { | |
844 | printk(KERN_ERR "%s: Error setting key for crypto context; " | |
845 | "rc = [%d]. s->auth_tok->token.password.session_key_" | |
846 | "encryption_key = [0x%p]; mount_crypt_stat->" | |
df261c52 | 847 | "global_default_fn_cipher_key_bytes = [%zd]\n", __func__, |
9c79f34f MH |
848 | rc, |
849 | s->auth_tok->token.password.session_key_encryption_key, | |
850 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
851 | goto out_release_free_unlock; | |
852 | } | |
8d08dab7 | 853 | rc = crypto_blkcipher_encrypt_iv(&s->desc, s->dst_sg, s->src_sg, |
9c79f34f MH |
854 | s->block_aligned_filename_size); |
855 | if (rc) { | |
856 | printk(KERN_ERR "%s: Error attempting to encrypt filename; " | |
857 | "rc = [%d]\n", __func__, rc); | |
858 | goto out_release_free_unlock; | |
859 | } | |
860 | s->i += s->block_aligned_filename_size; | |
861 | (*packet_size) = s->i; | |
862 | (*remaining_bytes) -= (*packet_size); | |
863 | out_release_free_unlock: | |
864 | crypto_free_hash(s->hash_desc.tfm); | |
865 | out_free_unlock: | |
00fcf2cb | 866 | kzfree(s->block_aligned_filename); |
9c79f34f MH |
867 | out_unlock: |
868 | mutex_unlock(s->tfm_mutex); | |
869 | out: | |
b5695d04 RS |
870 | if (auth_tok_key) { |
871 | up_write(&(auth_tok_key->sem)); | |
aee683b9 | 872 | key_put(auth_tok_key); |
b5695d04 | 873 | } |
9c79f34f MH |
874 | kfree(s); |
875 | return rc; | |
876 | } | |
877 | ||
878 | struct ecryptfs_parse_tag_70_packet_silly_stack { | |
879 | u8 cipher_code; | |
880 | size_t max_packet_size; | |
881 | size_t packet_size_len; | |
882 | size_t parsed_tag_70_packet_size; | |
883 | size_t block_aligned_filename_size; | |
884 | size_t block_size; | |
885 | size_t i; | |
886 | struct mutex *tfm_mutex; | |
887 | char *decrypted_filename; | |
888 | struct ecryptfs_auth_tok *auth_tok; | |
8d08dab7 TH |
889 | struct scatterlist src_sg[2]; |
890 | struct scatterlist dst_sg[2]; | |
9c79f34f MH |
891 | struct blkcipher_desc desc; |
892 | char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1]; | |
893 | char iv[ECRYPTFS_MAX_IV_BYTES]; | |
894 | char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE]; | |
895 | }; | |
896 | ||
897 | /** | |
898 | * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet | |
899 | * @filename: This function kmalloc's the memory for the filename | |
7d8bc2be MH |
900 | * @filename_size: This function sets this to the amount of memory |
901 | * kmalloc'd for the filename | |
902 | * @packet_size: This function sets this to the the number of octets | |
903 | * in the packet parsed | |
904 | * @mount_crypt_stat: The mount-wide cryptographic context | |
905 | * @data: The memory location containing the start of the tag 70 | |
906 | * packet | |
907 | * @max_packet_size: The maximum legal size of the packet to be parsed | |
908 | * from @data | |
909 | * | |
910 | * Returns zero on success; non-zero otherwise | |
9c79f34f MH |
911 | */ |
912 | int | |
913 | ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, | |
914 | size_t *packet_size, | |
915 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
916 | char *data, size_t max_packet_size) | |
917 | { | |
918 | struct ecryptfs_parse_tag_70_packet_silly_stack *s; | |
aee683b9 | 919 | struct key *auth_tok_key = NULL; |
9c79f34f MH |
920 | int rc = 0; |
921 | ||
922 | (*packet_size) = 0; | |
923 | (*filename_size) = 0; | |
924 | (*filename) = NULL; | |
925 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
926 | if (!s) { | |
927 | printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc " | |
a8f12864 | 928 | "[%zd] bytes of kernel memory\n", __func__, sizeof(*s)); |
f137f150 | 929 | rc = -ENOMEM; |
9c79f34f MH |
930 | goto out; |
931 | } | |
932 | s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; | |
4a26620d | 933 | if (max_packet_size < ECRYPTFS_TAG_70_MIN_METADATA_SIZE) { |
df261c52 | 934 | printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be " |
9c79f34f | 935 | "at least [%d]\n", __func__, max_packet_size, |
4a26620d | 936 | ECRYPTFS_TAG_70_MIN_METADATA_SIZE); |
9c79f34f MH |
937 | rc = -EINVAL; |
938 | goto out; | |
939 | } | |
940 | /* Octet 0: Tag 70 identifier | |
941 | * Octets 1-N1: Tag 70 packet size (includes cipher identifier | |
942 | * and block-aligned encrypted filename size) | |
943 | * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) | |
944 | * Octet N2-N3: Cipher identifier (1 octet) | |
945 | * Octets N3-N4: Block-aligned encrypted filename | |
946 | * - Consists of a minimum number of random numbers, a \0 | |
947 | * separator, and then the filename */ | |
948 | if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) { | |
949 | printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be " | |
950 | "tag [0x%.2x]\n", __func__, | |
951 | data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE); | |
952 | rc = -EINVAL; | |
953 | goto out; | |
954 | } | |
955 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], | |
956 | &s->parsed_tag_70_packet_size, | |
957 | &s->packet_size_len); | |
958 | if (rc) { | |
959 | printk(KERN_WARNING "%s: Error parsing packet length; " | |
960 | "rc = [%d]\n", __func__, rc); | |
961 | goto out; | |
962 | } | |
963 | s->block_aligned_filename_size = (s->parsed_tag_70_packet_size | |
964 | - ECRYPTFS_SIG_SIZE - 1); | |
965 | if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size) | |
966 | > max_packet_size) { | |
a8f12864 MH |
967 | printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet " |
968 | "size is [%zd]\n", __func__, max_packet_size, | |
9c79f34f MH |
969 | (1 + s->packet_size_len + 1 |
970 | + s->block_aligned_filename_size)); | |
971 | rc = -EINVAL; | |
972 | goto out; | |
973 | } | |
974 | (*packet_size) += s->packet_size_len; | |
975 | ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)], | |
976 | ECRYPTFS_SIG_SIZE); | |
977 | s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0'; | |
978 | (*packet_size) += ECRYPTFS_SIG_SIZE; | |
979 | s->cipher_code = data[(*packet_size)++]; | |
980 | rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code); | |
981 | if (rc) { | |
982 | printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n", | |
983 | __func__, s->cipher_code); | |
984 | goto out; | |
985 | } | |
950983fc RS |
986 | rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key, |
987 | &s->auth_tok, mount_crypt_stat, | |
988 | s->fnek_sig_hex); | |
989 | if (rc) { | |
990 | printk(KERN_ERR "%s: Error attempting to find auth tok for " | |
991 | "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex, | |
992 | rc); | |
993 | goto out; | |
994 | } | |
9c79f34f MH |
995 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm, |
996 | &s->tfm_mutex, | |
997 | s->cipher_string); | |
998 | if (unlikely(rc)) { | |
999 | printk(KERN_ERR "Internal error whilst attempting to get " | |
1000 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
1001 | s->cipher_string, rc); | |
1002 | goto out; | |
1003 | } | |
1004 | mutex_lock(s->tfm_mutex); | |
1005 | rc = virt_to_scatterlist(&data[(*packet_size)], | |
8d08dab7 TH |
1006 | s->block_aligned_filename_size, s->src_sg, 2); |
1007 | if (rc < 1) { | |
9c79f34f MH |
1008 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
1009 | "convert encrypted filename memory to scatterlist; " | |
8d08dab7 TH |
1010 | "rc = [%d]. block_aligned_filename_size = [%zd]\n", |
1011 | __func__, rc, s->block_aligned_filename_size); | |
9c79f34f MH |
1012 | goto out_unlock; |
1013 | } | |
1014 | (*packet_size) += s->block_aligned_filename_size; | |
1015 | s->decrypted_filename = kmalloc(s->block_aligned_filename_size, | |
1016 | GFP_KERNEL); | |
1017 | if (!s->decrypted_filename) { | |
1018 | printk(KERN_ERR "%s: Out of memory whilst attempting to " | |
a8f12864 | 1019 | "kmalloc [%zd] bytes\n", __func__, |
9c79f34f MH |
1020 | s->block_aligned_filename_size); |
1021 | rc = -ENOMEM; | |
1022 | goto out_unlock; | |
1023 | } | |
1024 | rc = virt_to_scatterlist(s->decrypted_filename, | |
8d08dab7 TH |
1025 | s->block_aligned_filename_size, s->dst_sg, 2); |
1026 | if (rc < 1) { | |
9c79f34f MH |
1027 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
1028 | "convert decrypted filename memory to scatterlist; " | |
8d08dab7 TH |
1029 | "rc = [%d]. block_aligned_filename_size = [%zd]\n", |
1030 | __func__, rc, s->block_aligned_filename_size); | |
9c79f34f MH |
1031 | goto out_free_unlock; |
1032 | } | |
1033 | /* The characters in the first block effectively do the job of | |
1034 | * the IV here, so we just use 0's for the IV. Note the | |
1035 | * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES | |
1036 | * >= ECRYPTFS_MAX_IV_BYTES. */ | |
1037 | memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES); | |
1038 | s->desc.info = s->iv; | |
9c79f34f MH |
1039 | /* TODO: Support other key modules than passphrase for |
1040 | * filename encryption */ | |
df6ad33b TH |
1041 | if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) { |
1042 | rc = -EOPNOTSUPP; | |
1043 | printk(KERN_INFO "%s: Filename encryption only supports " | |
1044 | "password tokens\n", __func__); | |
1045 | goto out_free_unlock; | |
1046 | } | |
9c79f34f MH |
1047 | rc = crypto_blkcipher_setkey( |
1048 | s->desc.tfm, | |
1049 | s->auth_tok->token.password.session_key_encryption_key, | |
1050 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
1051 | if (rc < 0) { | |
1052 | printk(KERN_ERR "%s: Error setting key for crypto context; " | |
1053 | "rc = [%d]. s->auth_tok->token.password.session_key_" | |
1054 | "encryption_key = [0x%p]; mount_crypt_stat->" | |
df261c52 | 1055 | "global_default_fn_cipher_key_bytes = [%zd]\n", __func__, |
9c79f34f MH |
1056 | rc, |
1057 | s->auth_tok->token.password.session_key_encryption_key, | |
1058 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
1059 | goto out_free_unlock; | |
1060 | } | |
8d08dab7 | 1061 | rc = crypto_blkcipher_decrypt_iv(&s->desc, s->dst_sg, s->src_sg, |
9c79f34f MH |
1062 | s->block_aligned_filename_size); |
1063 | if (rc) { | |
1064 | printk(KERN_ERR "%s: Error attempting to decrypt filename; " | |
1065 | "rc = [%d]\n", __func__, rc); | |
1066 | goto out_free_unlock; | |
1067 | } | |
1068 | s->i = 0; | |
1069 | while (s->decrypted_filename[s->i] != '\0' | |
1070 | && s->i < s->block_aligned_filename_size) | |
1071 | s->i++; | |
1072 | if (s->i == s->block_aligned_filename_size) { | |
1073 | printk(KERN_WARNING "%s: Invalid tag 70 packet; could not " | |
1074 | "find valid separator between random characters and " | |
1075 | "the filename\n", __func__); | |
1076 | rc = -EINVAL; | |
1077 | goto out_free_unlock; | |
1078 | } | |
1079 | s->i++; | |
1080 | (*filename_size) = (s->block_aligned_filename_size - s->i); | |
1081 | if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) { | |
df261c52 | 1082 | printk(KERN_WARNING "%s: Filename size is [%zd], which is " |
9c79f34f MH |
1083 | "invalid\n", __func__, (*filename_size)); |
1084 | rc = -EINVAL; | |
1085 | goto out_free_unlock; | |
1086 | } | |
1087 | (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL); | |
1088 | if (!(*filename)) { | |
1089 | printk(KERN_ERR "%s: Out of memory whilst attempting to " | |
a8f12864 | 1090 | "kmalloc [%zd] bytes\n", __func__, |
9c79f34f MH |
1091 | ((*filename_size) + 1)); |
1092 | rc = -ENOMEM; | |
1093 | goto out_free_unlock; | |
1094 | } | |
1095 | memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size)); | |
1096 | (*filename)[(*filename_size)] = '\0'; | |
1097 | out_free_unlock: | |
1098 | kfree(s->decrypted_filename); | |
1099 | out_unlock: | |
1100 | mutex_unlock(s->tfm_mutex); | |
1101 | out: | |
1102 | if (rc) { | |
1103 | (*packet_size) = 0; | |
1104 | (*filename_size) = 0; | |
1105 | (*filename) = NULL; | |
1106 | } | |
b5695d04 RS |
1107 | if (auth_tok_key) { |
1108 | up_write(&(auth_tok_key->sem)); | |
aee683b9 | 1109 | key_put(auth_tok_key); |
b5695d04 | 1110 | } |
9c79f34f MH |
1111 | kfree(s); |
1112 | return rc; | |
1113 | } | |
1114 | ||
cd9d67df MH |
1115 | static int |
1116 | ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok) | |
1117 | { | |
1118 | int rc = 0; | |
1119 | ||
1120 | (*sig) = NULL; | |
1121 | switch (auth_tok->token_type) { | |
1122 | case ECRYPTFS_PASSWORD: | |
1123 | (*sig) = auth_tok->token.password.signature; | |
1124 | break; | |
1125 | case ECRYPTFS_PRIVATE_KEY: | |
1126 | (*sig) = auth_tok->token.private_key.signature; | |
1127 | break; | |
1128 | default: | |
1129 | printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n", | |
1130 | auth_tok->token_type); | |
1131 | rc = -EINVAL; | |
1132 | } | |
1133 | return rc; | |
1134 | } | |
1135 | ||
dddfa461 | 1136 | /** |
22e78faf MH |
1137 | * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok. |
1138 | * @auth_tok: The key authentication token used to decrypt the session key | |
1139 | * @crypt_stat: The cryptographic context | |
dddfa461 | 1140 | * |
22e78faf | 1141 | * Returns zero on success; non-zero error otherwise. |
dddfa461 | 1142 | */ |
f4aad16a MH |
1143 | static int |
1144 | decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, | |
1145 | struct ecryptfs_crypt_stat *crypt_stat) | |
dddfa461 | 1146 | { |
19e66a67 | 1147 | u8 cipher_code = 0; |
dddfa461 MH |
1148 | struct ecryptfs_msg_ctx *msg_ctx; |
1149 | struct ecryptfs_message *msg = NULL; | |
f4aad16a | 1150 | char *auth_tok_sig; |
3edc8376 | 1151 | char *payload = NULL; |
fa519964 | 1152 | size_t payload_len = 0; |
dddfa461 MH |
1153 | int rc; |
1154 | ||
5dda6992 MH |
1155 | rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok); |
1156 | if (rc) { | |
f4aad16a MH |
1157 | printk(KERN_ERR "Unrecognized auth tok type: [%d]\n", |
1158 | auth_tok->token_type); | |
1159 | goto out; | |
1160 | } | |
1161 | rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key), | |
624ae528 | 1162 | &payload, &payload_len); |
dddfa461 | 1163 | if (rc) { |
f66e883e | 1164 | ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n"); |
dddfa461 MH |
1165 | goto out; |
1166 | } | |
624ae528 | 1167 | rc = ecryptfs_send_message(payload, payload_len, &msg_ctx); |
dddfa461 | 1168 | if (rc) { |
624ae528 | 1169 | ecryptfs_printk(KERN_ERR, "Error sending message to " |
290502be | 1170 | "ecryptfsd: %d\n", rc); |
dddfa461 MH |
1171 | goto out; |
1172 | } | |
1173 | rc = ecryptfs_wait_for_response(msg_ctx, &msg); | |
1174 | if (rc) { | |
1175 | ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet " | |
1176 | "from the user space daemon\n"); | |
1177 | rc = -EIO; | |
1178 | goto out; | |
1179 | } | |
1180 | rc = parse_tag_65_packet(&(auth_tok->session_key), | |
1181 | &cipher_code, msg); | |
1182 | if (rc) { | |
1183 | printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n", | |
1184 | rc); | |
1185 | goto out; | |
1186 | } | |
1187 | auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1188 | memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, | |
1189 | auth_tok->session_key.decrypted_key_size); | |
1190 | crypt_stat->key_size = auth_tok->session_key.decrypted_key_size; | |
1191 | rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code); | |
1192 | if (rc) { | |
1193 | ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n", | |
1194 | cipher_code) | |
1195 | goto out; | |
1196 | } | |
1197 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; | |
1198 | if (ecryptfs_verbosity > 0) { | |
1199 | ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n"); | |
1200 | ecryptfs_dump_hex(crypt_stat->key, | |
1201 | crypt_stat->key_size); | |
1202 | } | |
1203 | out: | |
3a467418 | 1204 | kfree(msg); |
3edc8376 | 1205 | kfree(payload); |
dddfa461 MH |
1206 | return rc; |
1207 | } | |
1208 | ||
1209 | static void wipe_auth_tok_list(struct list_head *auth_tok_list_head) | |
1210 | { | |
dddfa461 | 1211 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
e0869cc1 | 1212 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
dddfa461 | 1213 | |
e0869cc1 MH |
1214 | list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp, |
1215 | auth_tok_list_head, list) { | |
1216 | list_del(&auth_tok_list_item->list); | |
dddfa461 MH |
1217 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, |
1218 | auth_tok_list_item); | |
1219 | } | |
dddfa461 MH |
1220 | } |
1221 | ||
1222 | struct kmem_cache *ecryptfs_auth_tok_list_item_cache; | |
1223 | ||
dddfa461 MH |
1224 | /** |
1225 | * parse_tag_1_packet | |
22e78faf | 1226 | * @crypt_stat: The cryptographic context to modify based on packet contents |
dddfa461 MH |
1227 | * @data: The raw bytes of the packet. |
1228 | * @auth_tok_list: eCryptfs parses packets into authentication tokens; | |
22e78faf MH |
1229 | * a new authentication token will be placed at the |
1230 | * end of this list for this packet. | |
dddfa461 MH |
1231 | * @new_auth_tok: Pointer to a pointer to memory that this function |
1232 | * allocates; sets the memory address of the pointer to | |
1233 | * NULL on error. This object is added to the | |
1234 | * auth_tok_list. | |
1235 | * @packet_size: This function writes the size of the parsed packet | |
1236 | * into this memory location; zero on error. | |
22e78faf | 1237 | * @max_packet_size: The maximum allowable packet size |
dddfa461 MH |
1238 | * |
1239 | * Returns zero on success; non-zero on error. | |
1240 | */ | |
1241 | static int | |
1242 | parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat, | |
1243 | unsigned char *data, struct list_head *auth_tok_list, | |
1244 | struct ecryptfs_auth_tok **new_auth_tok, | |
1245 | size_t *packet_size, size_t max_packet_size) | |
1246 | { | |
1247 | size_t body_size; | |
1248 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; | |
1249 | size_t length_size; | |
1250 | int rc = 0; | |
1251 | ||
1252 | (*packet_size) = 0; | |
1253 | (*new_auth_tok) = NULL; | |
13218179 MH |
1254 | /** |
1255 | * This format is inspired by OpenPGP; see RFC 2440 | |
1256 | * packet tag 1 | |
1257 | * | |
1258 | * Tag 1 identifier (1 byte) | |
1259 | * Max Tag 1 packet size (max 3 bytes) | |
1260 | * Version (1 byte) | |
1261 | * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE) | |
1262 | * Cipher identifier (1 byte) | |
1263 | * Encrypted key size (arbitrary) | |
1264 | * | |
1265 | * 12 bytes minimum packet size | |
dddfa461 | 1266 | */ |
13218179 MH |
1267 | if (unlikely(max_packet_size < 12)) { |
1268 | printk(KERN_ERR "Invalid max packet size; must be >=12\n"); | |
dddfa461 MH |
1269 | rc = -EINVAL; |
1270 | goto out; | |
1271 | } | |
dddfa461 | 1272 | if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) { |
13218179 MH |
1273 | printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n", |
1274 | ECRYPTFS_TAG_1_PACKET_TYPE); | |
dddfa461 MH |
1275 | rc = -EINVAL; |
1276 | goto out; | |
1277 | } | |
1278 | /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or | |
1279 | * at end of function upon failure */ | |
1280 | auth_tok_list_item = | |
13218179 MH |
1281 | kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, |
1282 | GFP_KERNEL); | |
dddfa461 | 1283 | if (!auth_tok_list_item) { |
13218179 | 1284 | printk(KERN_ERR "Unable to allocate memory\n"); |
dddfa461 MH |
1285 | rc = -ENOMEM; |
1286 | goto out; | |
1287 | } | |
dddfa461 | 1288 | (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
f66e883e MH |
1289 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1290 | &length_size); | |
5dda6992 | 1291 | if (rc) { |
13218179 MH |
1292 | printk(KERN_WARNING "Error parsing packet length; " |
1293 | "rc = [%d]\n", rc); | |
dddfa461 MH |
1294 | goto out_free; |
1295 | } | |
13218179 | 1296 | if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) { |
81acbcd6 | 1297 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
dddfa461 MH |
1298 | rc = -EINVAL; |
1299 | goto out_free; | |
1300 | } | |
1301 | (*packet_size) += length_size; | |
1302 | if (unlikely((*packet_size) + body_size > max_packet_size)) { | |
13218179 | 1303 | printk(KERN_WARNING "Packet size exceeds max\n"); |
dddfa461 MH |
1304 | rc = -EINVAL; |
1305 | goto out_free; | |
1306 | } | |
dddfa461 | 1307 | if (unlikely(data[(*packet_size)++] != 0x03)) { |
13218179 MH |
1308 | printk(KERN_WARNING "Unknown version number [%d]\n", |
1309 | data[(*packet_size) - 1]); | |
dddfa461 MH |
1310 | rc = -EINVAL; |
1311 | goto out_free; | |
1312 | } | |
dddfa461 MH |
1313 | ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature, |
1314 | &data[(*packet_size)], ECRYPTFS_SIG_SIZE); | |
1315 | *packet_size += ECRYPTFS_SIG_SIZE; | |
1316 | /* This byte is skipped because the kernel does not need to | |
1317 | * know which public key encryption algorithm was used */ | |
1318 | (*packet_size)++; | |
1319 | (*new_auth_tok)->session_key.encrypted_key_size = | |
13218179 | 1320 | body_size - (ECRYPTFS_SIG_SIZE + 2); |
dddfa461 MH |
1321 | if ((*new_auth_tok)->session_key.encrypted_key_size |
1322 | > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
13218179 MH |
1323 | printk(KERN_WARNING "Tag 1 packet contains key larger " |
1324 | "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES"); | |
dddfa461 MH |
1325 | rc = -EINVAL; |
1326 | goto out; | |
1327 | } | |
dddfa461 | 1328 | memcpy((*new_auth_tok)->session_key.encrypted_key, |
13218179 | 1329 | &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2))); |
dddfa461 MH |
1330 | (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size; |
1331 | (*new_auth_tok)->session_key.flags &= | |
1332 | ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1333 | (*new_auth_tok)->session_key.flags |= | |
1334 | ECRYPTFS_CONTAINS_ENCRYPTED_KEY; | |
1335 | (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY; | |
13218179 | 1336 | (*new_auth_tok)->flags = 0; |
e2bd99ec MH |
1337 | (*new_auth_tok)->session_key.flags &= |
1338 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT); | |
1339 | (*new_auth_tok)->session_key.flags &= | |
1340 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT); | |
dddfa461 MH |
1341 | list_add(&auth_tok_list_item->list, auth_tok_list); |
1342 | goto out; | |
1343 | out_free: | |
1344 | (*new_auth_tok) = NULL; | |
1345 | memset(auth_tok_list_item, 0, | |
1346 | sizeof(struct ecryptfs_auth_tok_list_item)); | |
1347 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, | |
1348 | auth_tok_list_item); | |
1349 | out: | |
1350 | if (rc) | |
1351 | (*packet_size) = 0; | |
1352 | return rc; | |
1353 | } | |
1354 | ||
237fead6 MH |
1355 | /** |
1356 | * parse_tag_3_packet | |
1357 | * @crypt_stat: The cryptographic context to modify based on packet | |
1358 | * contents. | |
1359 | * @data: The raw bytes of the packet. | |
1360 | * @auth_tok_list: eCryptfs parses packets into authentication tokens; | |
1361 | * a new authentication token will be placed at the end | |
1362 | * of this list for this packet. | |
1363 | * @new_auth_tok: Pointer to a pointer to memory that this function | |
1364 | * allocates; sets the memory address of the pointer to | |
1365 | * NULL on error. This object is added to the | |
1366 | * auth_tok_list. | |
1367 | * @packet_size: This function writes the size of the parsed packet | |
1368 | * into this memory location; zero on error. | |
1369 | * @max_packet_size: maximum number of bytes to parse | |
1370 | * | |
1371 | * Returns zero on success; non-zero on error. | |
1372 | */ | |
1373 | static int | |
1374 | parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat, | |
1375 | unsigned char *data, struct list_head *auth_tok_list, | |
1376 | struct ecryptfs_auth_tok **new_auth_tok, | |
1377 | size_t *packet_size, size_t max_packet_size) | |
1378 | { | |
237fead6 MH |
1379 | size_t body_size; |
1380 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; | |
1381 | size_t length_size; | |
dddfa461 | 1382 | int rc = 0; |
237fead6 MH |
1383 | |
1384 | (*packet_size) = 0; | |
1385 | (*new_auth_tok) = NULL; | |
c59becfc MH |
1386 | /** |
1387 | *This format is inspired by OpenPGP; see RFC 2440 | |
1388 | * packet tag 3 | |
1389 | * | |
1390 | * Tag 3 identifier (1 byte) | |
1391 | * Max Tag 3 packet size (max 3 bytes) | |
1392 | * Version (1 byte) | |
1393 | * Cipher code (1 byte) | |
1394 | * S2K specifier (1 byte) | |
1395 | * Hash identifier (1 byte) | |
1396 | * Salt (ECRYPTFS_SALT_SIZE) | |
1397 | * Hash iterations (1 byte) | |
1398 | * Encrypted key (arbitrary) | |
1399 | * | |
1400 | * (ECRYPTFS_SALT_SIZE + 7) minimum packet size | |
237fead6 | 1401 | */ |
c59becfc MH |
1402 | if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) { |
1403 | printk(KERN_ERR "Max packet size too large\n"); | |
237fead6 MH |
1404 | rc = -EINVAL; |
1405 | goto out; | |
1406 | } | |
237fead6 | 1407 | if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) { |
c59becfc MH |
1408 | printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n", |
1409 | ECRYPTFS_TAG_3_PACKET_TYPE); | |
237fead6 MH |
1410 | rc = -EINVAL; |
1411 | goto out; | |
1412 | } | |
1413 | /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or | |
1414 | * at end of function upon failure */ | |
1415 | auth_tok_list_item = | |
c3762229 | 1416 | kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL); |
237fead6 | 1417 | if (!auth_tok_list_item) { |
c59becfc | 1418 | printk(KERN_ERR "Unable to allocate memory\n"); |
237fead6 MH |
1419 | rc = -ENOMEM; |
1420 | goto out; | |
1421 | } | |
237fead6 | 1422 | (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
f66e883e MH |
1423 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1424 | &length_size); | |
5dda6992 | 1425 | if (rc) { |
c59becfc MH |
1426 | printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n", |
1427 | rc); | |
237fead6 MH |
1428 | goto out_free; |
1429 | } | |
c59becfc | 1430 | if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) { |
81acbcd6 | 1431 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
237fead6 MH |
1432 | rc = -EINVAL; |
1433 | goto out_free; | |
1434 | } | |
1435 | (*packet_size) += length_size; | |
237fead6 | 1436 | if (unlikely((*packet_size) + body_size > max_packet_size)) { |
c59becfc | 1437 | printk(KERN_ERR "Packet size exceeds max\n"); |
237fead6 MH |
1438 | rc = -EINVAL; |
1439 | goto out_free; | |
1440 | } | |
237fead6 | 1441 | (*new_auth_tok)->session_key.encrypted_key_size = |
c59becfc | 1442 | (body_size - (ECRYPTFS_SALT_SIZE + 5)); |
f151cd2c RCV |
1443 | if ((*new_auth_tok)->session_key.encrypted_key_size |
1444 | > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
1445 | printk(KERN_WARNING "Tag 3 packet contains key larger " | |
1446 | "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n"); | |
1447 | rc = -EINVAL; | |
1448 | goto out_free; | |
1449 | } | |
237fead6 | 1450 | if (unlikely(data[(*packet_size)++] != 0x04)) { |
c59becfc MH |
1451 | printk(KERN_WARNING "Unknown version number [%d]\n", |
1452 | data[(*packet_size) - 1]); | |
237fead6 MH |
1453 | rc = -EINVAL; |
1454 | goto out_free; | |
1455 | } | |
b0105eae TH |
1456 | rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, |
1457 | (u16)data[(*packet_size)]); | |
1458 | if (rc) | |
1459 | goto out_free; | |
237fead6 MH |
1460 | /* A little extra work to differentiate among the AES key |
1461 | * sizes; see RFC2440 */ | |
1462 | switch(data[(*packet_size)++]) { | |
1463 | case RFC2440_CIPHER_AES_192: | |
1464 | crypt_stat->key_size = 24; | |
1465 | break; | |
1466 | default: | |
1467 | crypt_stat->key_size = | |
1468 | (*new_auth_tok)->session_key.encrypted_key_size; | |
1469 | } | |
b0105eae TH |
1470 | rc = ecryptfs_init_crypt_ctx(crypt_stat); |
1471 | if (rc) | |
1472 | goto out_free; | |
237fead6 | 1473 | if (unlikely(data[(*packet_size)++] != 0x03)) { |
c59becfc | 1474 | printk(KERN_WARNING "Only S2K ID 3 is currently supported\n"); |
237fead6 MH |
1475 | rc = -ENOSYS; |
1476 | goto out_free; | |
1477 | } | |
237fead6 | 1478 | /* TODO: finish the hash mapping */ |
237fead6 MH |
1479 | switch (data[(*packet_size)++]) { |
1480 | case 0x01: /* See RFC2440 for these numbers and their mappings */ | |
1481 | /* Choose MD5 */ | |
237fead6 MH |
1482 | memcpy((*new_auth_tok)->token.password.salt, |
1483 | &data[(*packet_size)], ECRYPTFS_SALT_SIZE); | |
1484 | (*packet_size) += ECRYPTFS_SALT_SIZE; | |
237fead6 | 1485 | /* This conversion was taken straight from RFC2440 */ |
237fead6 MH |
1486 | (*new_auth_tok)->token.password.hash_iterations = |
1487 | ((u32) 16 + (data[(*packet_size)] & 15)) | |
1488 | << ((data[(*packet_size)] >> 4) + 6); | |
1489 | (*packet_size)++; | |
c59becfc MH |
1490 | /* Friendly reminder: |
1491 | * (*new_auth_tok)->session_key.encrypted_key_size = | |
1492 | * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */ | |
237fead6 MH |
1493 | memcpy((*new_auth_tok)->session_key.encrypted_key, |
1494 | &data[(*packet_size)], | |
1495 | (*new_auth_tok)->session_key.encrypted_key_size); | |
1496 | (*packet_size) += | |
1497 | (*new_auth_tok)->session_key.encrypted_key_size; | |
1498 | (*new_auth_tok)->session_key.flags &= | |
1499 | ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1500 | (*new_auth_tok)->session_key.flags |= | |
1501 | ECRYPTFS_CONTAINS_ENCRYPTED_KEY; | |
c59becfc | 1502 | (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */ |
237fead6 MH |
1503 | break; |
1504 | default: | |
1505 | ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: " | |
1506 | "[%d]\n", data[(*packet_size) - 1]); | |
1507 | rc = -ENOSYS; | |
1508 | goto out_free; | |
1509 | } | |
1510 | (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD; | |
1511 | /* TODO: Parametarize; we might actually want userspace to | |
1512 | * decrypt the session key. */ | |
e2bd99ec MH |
1513 | (*new_auth_tok)->session_key.flags &= |
1514 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT); | |
1515 | (*new_auth_tok)->session_key.flags &= | |
1516 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT); | |
237fead6 MH |
1517 | list_add(&auth_tok_list_item->list, auth_tok_list); |
1518 | goto out; | |
1519 | out_free: | |
1520 | (*new_auth_tok) = NULL; | |
1521 | memset(auth_tok_list_item, 0, | |
1522 | sizeof(struct ecryptfs_auth_tok_list_item)); | |
1523 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, | |
1524 | auth_tok_list_item); | |
1525 | out: | |
1526 | if (rc) | |
1527 | (*packet_size) = 0; | |
1528 | return rc; | |
1529 | } | |
1530 | ||
1531 | /** | |
1532 | * parse_tag_11_packet | |
1533 | * @data: The raw bytes of the packet | |
1534 | * @contents: This function writes the data contents of the literal | |
1535 | * packet into this memory location | |
1536 | * @max_contents_bytes: The maximum number of bytes that this function | |
1537 | * is allowed to write into contents | |
1538 | * @tag_11_contents_size: This function writes the size of the parsed | |
1539 | * contents into this memory location; zero on | |
1540 | * error | |
1541 | * @packet_size: This function writes the size of the parsed packet | |
1542 | * into this memory location; zero on error | |
1543 | * @max_packet_size: maximum number of bytes to parse | |
1544 | * | |
1545 | * Returns zero on success; non-zero on error. | |
1546 | */ | |
1547 | static int | |
1548 | parse_tag_11_packet(unsigned char *data, unsigned char *contents, | |
1549 | size_t max_contents_bytes, size_t *tag_11_contents_size, | |
1550 | size_t *packet_size, size_t max_packet_size) | |
1551 | { | |
237fead6 MH |
1552 | size_t body_size; |
1553 | size_t length_size; | |
dddfa461 | 1554 | int rc = 0; |
237fead6 MH |
1555 | |
1556 | (*packet_size) = 0; | |
1557 | (*tag_11_contents_size) = 0; | |
f648104a MH |
1558 | /* This format is inspired by OpenPGP; see RFC 2440 |
1559 | * packet tag 11 | |
1560 | * | |
1561 | * Tag 11 identifier (1 byte) | |
1562 | * Max Tag 11 packet size (max 3 bytes) | |
1563 | * Binary format specifier (1 byte) | |
1564 | * Filename length (1 byte) | |
1565 | * Filename ("_CONSOLE") (8 bytes) | |
1566 | * Modification date (4 bytes) | |
1567 | * Literal data (arbitrary) | |
1568 | * | |
1569 | * We need at least 16 bytes of data for the packet to even be | |
1570 | * valid. | |
237fead6 | 1571 | */ |
f648104a MH |
1572 | if (max_packet_size < 16) { |
1573 | printk(KERN_ERR "Maximum packet size too small\n"); | |
237fead6 MH |
1574 | rc = -EINVAL; |
1575 | goto out; | |
1576 | } | |
237fead6 | 1577 | if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) { |
f648104a | 1578 | printk(KERN_WARNING "Invalid tag 11 packet format\n"); |
237fead6 MH |
1579 | rc = -EINVAL; |
1580 | goto out; | |
1581 | } | |
f66e883e MH |
1582 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1583 | &length_size); | |
5dda6992 | 1584 | if (rc) { |
f648104a | 1585 | printk(KERN_WARNING "Invalid tag 11 packet format\n"); |
237fead6 MH |
1586 | goto out; |
1587 | } | |
f648104a | 1588 | if (body_size < 14) { |
81acbcd6 | 1589 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
237fead6 MH |
1590 | rc = -EINVAL; |
1591 | goto out; | |
1592 | } | |
f648104a MH |
1593 | (*packet_size) += length_size; |
1594 | (*tag_11_contents_size) = (body_size - 14); | |
237fead6 | 1595 | if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) { |
f648104a | 1596 | printk(KERN_ERR "Packet size exceeds max\n"); |
237fead6 MH |
1597 | rc = -EINVAL; |
1598 | goto out; | |
1599 | } | |
6352a293 TH |
1600 | if (unlikely((*tag_11_contents_size) > max_contents_bytes)) { |
1601 | printk(KERN_ERR "Literal data section in tag 11 packet exceeds " | |
1602 | "expected size\n"); | |
1603 | rc = -EINVAL; | |
1604 | goto out; | |
1605 | } | |
237fead6 | 1606 | if (data[(*packet_size)++] != 0x62) { |
f648104a | 1607 | printk(KERN_WARNING "Unrecognizable packet\n"); |
237fead6 MH |
1608 | rc = -EINVAL; |
1609 | goto out; | |
1610 | } | |
237fead6 | 1611 | if (data[(*packet_size)++] != 0x08) { |
f648104a | 1612 | printk(KERN_WARNING "Unrecognizable packet\n"); |
237fead6 MH |
1613 | rc = -EINVAL; |
1614 | goto out; | |
1615 | } | |
f648104a | 1616 | (*packet_size) += 12; /* Ignore filename and modification date */ |
237fead6 MH |
1617 | memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size)); |
1618 | (*packet_size) += (*tag_11_contents_size); | |
237fead6 MH |
1619 | out: |
1620 | if (rc) { | |
1621 | (*packet_size) = 0; | |
1622 | (*tag_11_contents_size) = 0; | |
1623 | } | |
1624 | return rc; | |
1625 | } | |
1626 | ||
f4aad16a MH |
1627 | int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key, |
1628 | struct ecryptfs_auth_tok **auth_tok, | |
1629 | char *sig) | |
1630 | { | |
1631 | int rc = 0; | |
1632 | ||
1633 | (*auth_tok_key) = request_key(&key_type_user, sig, NULL); | |
1634 | if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) { | |
1252cc3b RS |
1635 | (*auth_tok_key) = ecryptfs_get_encrypted_key(sig); |
1636 | if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) { | |
1637 | printk(KERN_ERR "Could not find key with description: [%s]\n", | |
1638 | sig); | |
1639 | rc = process_request_key_err(PTR_ERR(*auth_tok_key)); | |
1640 | (*auth_tok_key) = NULL; | |
1641 | goto out; | |
1642 | } | |
f4aad16a | 1643 | } |
b5695d04 | 1644 | down_write(&(*auth_tok_key)->sem); |
0e1fc5ef | 1645 | rc = ecryptfs_verify_auth_tok_from_key(*auth_tok_key, auth_tok); |
aee683b9 | 1646 | if (rc) { |
b5695d04 | 1647 | up_write(&(*auth_tok_key)->sem); |
aee683b9 RS |
1648 | key_put(*auth_tok_key); |
1649 | (*auth_tok_key) = NULL; | |
0e1fc5ef | 1650 | goto out; |
f4aad16a MH |
1651 | } |
1652 | out: | |
1653 | return rc; | |
1654 | } | |
1655 | ||
f4aad16a | 1656 | /** |
22e78faf MH |
1657 | * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok. |
1658 | * @auth_tok: The passphrase authentication token to use to encrypt the FEK | |
1659 | * @crypt_stat: The cryptographic context | |
237fead6 | 1660 | * |
22e78faf | 1661 | * Returns zero on success; non-zero error otherwise |
237fead6 | 1662 | */ |
f4aad16a MH |
1663 | static int |
1664 | decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, | |
1665 | struct ecryptfs_crypt_stat *crypt_stat) | |
237fead6 | 1666 | { |
ac97b9f9 MH |
1667 | struct scatterlist dst_sg[2]; |
1668 | struct scatterlist src_sg[2]; | |
dd8e2902 | 1669 | struct mutex *tfm_mutex; |
8bba066f MH |
1670 | struct blkcipher_desc desc = { |
1671 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
1672 | }; | |
1673 | int rc = 0; | |
237fead6 | 1674 | |
f4aad16a MH |
1675 | if (unlikely(ecryptfs_verbosity > 0)) { |
1676 | ecryptfs_printk( | |
1677 | KERN_DEBUG, "Session key encryption key (size [%d]):\n", | |
1678 | auth_tok->token.password.session_key_encryption_key_bytes); | |
1679 | ecryptfs_dump_hex( | |
1680 | auth_tok->token.password.session_key_encryption_key, | |
1681 | auth_tok->token.password.session_key_encryption_key_bytes); | |
1682 | } | |
1683 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex, | |
1684 | crypt_stat->cipher); | |
1685 | if (unlikely(rc)) { | |
1686 | printk(KERN_ERR "Internal error whilst attempting to get " | |
1687 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
1688 | crypt_stat->cipher, rc); | |
1689 | goto out; | |
237fead6 | 1690 | } |
5dda6992 MH |
1691 | rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key, |
1692 | auth_tok->session_key.encrypted_key_size, | |
ac97b9f9 MH |
1693 | src_sg, 2); |
1694 | if (rc < 1 || rc > 2) { | |
f4aad16a MH |
1695 | printk(KERN_ERR "Internal error whilst attempting to convert " |
1696 | "auth_tok->session_key.encrypted_key to scatterlist; " | |
1697 | "expected rc = 1; got rc = [%d]. " | |
1698 | "auth_tok->session_key.encrypted_key_size = [%d]\n", rc, | |
1699 | auth_tok->session_key.encrypted_key_size); | |
1700 | goto out; | |
1701 | } | |
1702 | auth_tok->session_key.decrypted_key_size = | |
1703 | auth_tok->session_key.encrypted_key_size; | |
5dda6992 MH |
1704 | rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key, |
1705 | auth_tok->session_key.decrypted_key_size, | |
ac97b9f9 MH |
1706 | dst_sg, 2); |
1707 | if (rc < 1 || rc > 2) { | |
f4aad16a MH |
1708 | printk(KERN_ERR "Internal error whilst attempting to convert " |
1709 | "auth_tok->session_key.decrypted_key to scatterlist; " | |
1710 | "expected rc = 1; got rc = [%d]\n", rc); | |
1711 | goto out; | |
1712 | } | |
1713 | mutex_lock(tfm_mutex); | |
1714 | rc = crypto_blkcipher_setkey( | |
1715 | desc.tfm, auth_tok->token.password.session_key_encryption_key, | |
1716 | crypt_stat->key_size); | |
1717 | if (unlikely(rc < 0)) { | |
1718 | mutex_unlock(tfm_mutex); | |
e5d9cbde MH |
1719 | printk(KERN_ERR "Error setting key for crypto context\n"); |
1720 | rc = -EINVAL; | |
f4aad16a | 1721 | goto out; |
237fead6 | 1722 | } |
ac97b9f9 | 1723 | rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg, |
8bba066f | 1724 | auth_tok->session_key.encrypted_key_size); |
f4aad16a MH |
1725 | mutex_unlock(tfm_mutex); |
1726 | if (unlikely(rc)) { | |
8bba066f | 1727 | printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc); |
f4aad16a | 1728 | goto out; |
8bba066f | 1729 | } |
237fead6 MH |
1730 | auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; |
1731 | memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, | |
1732 | auth_tok->session_key.decrypted_key_size); | |
e2bd99ec | 1733 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; |
f4aad16a | 1734 | if (unlikely(ecryptfs_verbosity > 0)) { |
f24b3887 | 1735 | ecryptfs_printk(KERN_DEBUG, "FEK of size [%zd]:\n", |
f4aad16a | 1736 | crypt_stat->key_size); |
237fead6 MH |
1737 | ecryptfs_dump_hex(crypt_stat->key, |
1738 | crypt_stat->key_size); | |
f4aad16a | 1739 | } |
237fead6 MH |
1740 | out: |
1741 | return rc; | |
1742 | } | |
1743 | ||
1744 | /** | |
1745 | * ecryptfs_parse_packet_set | |
22e78faf MH |
1746 | * @crypt_stat: The cryptographic context |
1747 | * @src: Virtual address of region of memory containing the packets | |
1748 | * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set | |
237fead6 MH |
1749 | * |
1750 | * Get crypt_stat to have the file's session key if the requisite key | |
1751 | * is available to decrypt the session key. | |
1752 | * | |
1753 | * Returns Zero if a valid authentication token was retrieved and | |
1754 | * processed; negative value for file not encrypted or for error | |
1755 | * conditions. | |
1756 | */ | |
1757 | int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat, | |
1758 | unsigned char *src, | |
1759 | struct dentry *ecryptfs_dentry) | |
1760 | { | |
1761 | size_t i = 0; | |
f4aad16a | 1762 | size_t found_auth_tok; |
237fead6 | 1763 | size_t next_packet_is_auth_tok_packet; |
237fead6 | 1764 | struct list_head auth_tok_list; |
dd8e2902 MH |
1765 | struct ecryptfs_auth_tok *matching_auth_tok; |
1766 | struct ecryptfs_auth_tok *candidate_auth_tok; | |
f4aad16a | 1767 | char *candidate_auth_tok_sig; |
237fead6 MH |
1768 | size_t packet_size; |
1769 | struct ecryptfs_auth_tok *new_auth_tok; | |
1770 | unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE]; | |
f4aad16a | 1771 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
237fead6 MH |
1772 | size_t tag_11_contents_size; |
1773 | size_t tag_11_packet_size; | |
aee683b9 | 1774 | struct key *auth_tok_key = NULL; |
dddfa461 | 1775 | int rc = 0; |
237fead6 MH |
1776 | |
1777 | INIT_LIST_HEAD(&auth_tok_list); | |
f4aad16a | 1778 | /* Parse the header to find as many packets as we can; these will be |
237fead6 MH |
1779 | * added the our &auth_tok_list */ |
1780 | next_packet_is_auth_tok_packet = 1; | |
1781 | while (next_packet_is_auth_tok_packet) { | |
1782 | size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i); | |
1783 | ||
1784 | switch (src[i]) { | |
1785 | case ECRYPTFS_TAG_3_PACKET_TYPE: | |
1786 | rc = parse_tag_3_packet(crypt_stat, | |
1787 | (unsigned char *)&src[i], | |
1788 | &auth_tok_list, &new_auth_tok, | |
1789 | &packet_size, max_packet_size); | |
1790 | if (rc) { | |
1791 | ecryptfs_printk(KERN_ERR, "Error parsing " | |
1792 | "tag 3 packet\n"); | |
1793 | rc = -EIO; | |
1794 | goto out_wipe_list; | |
1795 | } | |
1796 | i += packet_size; | |
1797 | rc = parse_tag_11_packet((unsigned char *)&src[i], | |
1798 | sig_tmp_space, | |
1799 | ECRYPTFS_SIG_SIZE, | |
1800 | &tag_11_contents_size, | |
1801 | &tag_11_packet_size, | |
1802 | max_packet_size); | |
1803 | if (rc) { | |
1804 | ecryptfs_printk(KERN_ERR, "No valid " | |
1805 | "(ecryptfs-specific) literal " | |
1806 | "packet containing " | |
1807 | "authentication token " | |
1808 | "signature found after " | |
1809 | "tag 3 packet\n"); | |
1810 | rc = -EIO; | |
1811 | goto out_wipe_list; | |
1812 | } | |
1813 | i += tag_11_packet_size; | |
1814 | if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) { | |
1815 | ecryptfs_printk(KERN_ERR, "Expected " | |
1816 | "signature of size [%d]; " | |
f24b3887 | 1817 | "read size [%zd]\n", |
237fead6 MH |
1818 | ECRYPTFS_SIG_SIZE, |
1819 | tag_11_contents_size); | |
1820 | rc = -EIO; | |
1821 | goto out_wipe_list; | |
1822 | } | |
1823 | ecryptfs_to_hex(new_auth_tok->token.password.signature, | |
1824 | sig_tmp_space, tag_11_contents_size); | |
1825 | new_auth_tok->token.password.signature[ | |
1826 | ECRYPTFS_PASSWORD_SIG_SIZE] = '\0'; | |
e2bd99ec | 1827 | crypt_stat->flags |= ECRYPTFS_ENCRYPTED; |
237fead6 | 1828 | break; |
dddfa461 MH |
1829 | case ECRYPTFS_TAG_1_PACKET_TYPE: |
1830 | rc = parse_tag_1_packet(crypt_stat, | |
1831 | (unsigned char *)&src[i], | |
1832 | &auth_tok_list, &new_auth_tok, | |
1833 | &packet_size, max_packet_size); | |
1834 | if (rc) { | |
1835 | ecryptfs_printk(KERN_ERR, "Error parsing " | |
1836 | "tag 1 packet\n"); | |
1837 | rc = -EIO; | |
1838 | goto out_wipe_list; | |
1839 | } | |
1840 | i += packet_size; | |
e2bd99ec | 1841 | crypt_stat->flags |= ECRYPTFS_ENCRYPTED; |
dddfa461 | 1842 | break; |
237fead6 MH |
1843 | case ECRYPTFS_TAG_11_PACKET_TYPE: |
1844 | ecryptfs_printk(KERN_WARNING, "Invalid packet set " | |
1845 | "(Tag 11 not allowed by itself)\n"); | |
1846 | rc = -EIO; | |
1847 | goto out_wipe_list; | |
237fead6 | 1848 | default: |
f24b3887 TH |
1849 | ecryptfs_printk(KERN_DEBUG, "No packet at offset [%zd] " |
1850 | "of the file header; hex value of " | |
237fead6 MH |
1851 | "character is [0x%.2x]\n", i, src[i]); |
1852 | next_packet_is_auth_tok_packet = 0; | |
1853 | } | |
1854 | } | |
1855 | if (list_empty(&auth_tok_list)) { | |
f4aad16a MH |
1856 | printk(KERN_ERR "The lower file appears to be a non-encrypted " |
1857 | "eCryptfs file; this is not supported in this version " | |
1858 | "of the eCryptfs kernel module\n"); | |
1859 | rc = -EINVAL; | |
237fead6 MH |
1860 | goto out; |
1861 | } | |
f4aad16a MH |
1862 | /* auth_tok_list contains the set of authentication tokens |
1863 | * parsed from the metadata. We need to find a matching | |
1864 | * authentication token that has the secret component(s) | |
1865 | * necessary to decrypt the EFEK in the auth_tok parsed from | |
1866 | * the metadata. There may be several potential matches, but | |
1867 | * just one will be sufficient to decrypt to get the FEK. */ | |
1868 | find_next_matching_auth_tok: | |
1869 | found_auth_tok = 0; | |
1870 | list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) { | |
237fead6 MH |
1871 | candidate_auth_tok = &auth_tok_list_item->auth_tok; |
1872 | if (unlikely(ecryptfs_verbosity > 0)) { | |
1873 | ecryptfs_printk(KERN_DEBUG, | |
1874 | "Considering cadidate auth tok:\n"); | |
1875 | ecryptfs_dump_auth_tok(candidate_auth_tok); | |
1876 | } | |
5dda6992 MH |
1877 | rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig, |
1878 | candidate_auth_tok); | |
1879 | if (rc) { | |
f4aad16a MH |
1880 | printk(KERN_ERR |
1881 | "Unrecognized candidate auth tok type: [%d]\n", | |
1882 | candidate_auth_tok->token_type); | |
1883 | rc = -EINVAL; | |
1884 | goto out_wipe_list; | |
1885 | } | |
39fac853 | 1886 | rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key, |
aee683b9 | 1887 | &matching_auth_tok, |
9c79f34f | 1888 | crypt_stat->mount_crypt_stat, |
5dda6992 | 1889 | candidate_auth_tok_sig); |
39fac853 | 1890 | if (!rc) { |
dddfa461 | 1891 | found_auth_tok = 1; |
f4aad16a | 1892 | goto found_matching_auth_tok; |
237fead6 MH |
1893 | } |
1894 | } | |
237fead6 | 1895 | if (!found_auth_tok) { |
f4aad16a MH |
1896 | ecryptfs_printk(KERN_ERR, "Could not find a usable " |
1897 | "authentication token\n"); | |
237fead6 MH |
1898 | rc = -EIO; |
1899 | goto out_wipe_list; | |
dddfa461 | 1900 | } |
f4aad16a | 1901 | found_matching_auth_tok: |
e2bd99ec | 1902 | if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
dddfa461 | 1903 | memcpy(&(candidate_auth_tok->token.private_key), |
f4aad16a | 1904 | &(matching_auth_tok->token.private_key), |
dddfa461 | 1905 | sizeof(struct ecryptfs_private_key)); |
b2987a5e TH |
1906 | up_write(&(auth_tok_key->sem)); |
1907 | key_put(auth_tok_key); | |
f4aad16a | 1908 | rc = decrypt_pki_encrypted_session_key(candidate_auth_tok, |
dddfa461 MH |
1909 | crypt_stat); |
1910 | } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) { | |
237fead6 | 1911 | memcpy(&(candidate_auth_tok->token.password), |
f4aad16a | 1912 | &(matching_auth_tok->token.password), |
237fead6 | 1913 | sizeof(struct ecryptfs_password)); |
b2987a5e TH |
1914 | up_write(&(auth_tok_key->sem)); |
1915 | key_put(auth_tok_key); | |
f4aad16a MH |
1916 | rc = decrypt_passphrase_encrypted_session_key( |
1917 | candidate_auth_tok, crypt_stat); | |
b2987a5e TH |
1918 | } else { |
1919 | up_write(&(auth_tok_key->sem)); | |
1920 | key_put(auth_tok_key); | |
1921 | rc = -EINVAL; | |
dddfa461 MH |
1922 | } |
1923 | if (rc) { | |
f4aad16a MH |
1924 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
1925 | ||
1926 | ecryptfs_printk(KERN_WARNING, "Error decrypting the " | |
1927 | "session key for authentication token with sig " | |
1928 | "[%.*s]; rc = [%d]. Removing auth tok " | |
1929 | "candidate from the list and searching for " | |
888d57bb JP |
1930 | "the next match.\n", ECRYPTFS_SIG_SIZE_HEX, |
1931 | candidate_auth_tok_sig, rc); | |
f4aad16a MH |
1932 | list_for_each_entry_safe(auth_tok_list_item, |
1933 | auth_tok_list_item_tmp, | |
1934 | &auth_tok_list, list) { | |
1935 | if (candidate_auth_tok | |
1936 | == &auth_tok_list_item->auth_tok) { | |
1937 | list_del(&auth_tok_list_item->list); | |
1938 | kmem_cache_free( | |
1939 | ecryptfs_auth_tok_list_item_cache, | |
1940 | auth_tok_list_item); | |
1941 | goto find_next_matching_auth_tok; | |
1942 | } | |
1943 | } | |
1944 | BUG(); | |
dddfa461 MH |
1945 | } |
1946 | rc = ecryptfs_compute_root_iv(crypt_stat); | |
1947 | if (rc) { | |
1948 | ecryptfs_printk(KERN_ERR, "Error computing " | |
1949 | "the root IV\n"); | |
1950 | goto out_wipe_list; | |
237fead6 MH |
1951 | } |
1952 | rc = ecryptfs_init_crypt_ctx(crypt_stat); | |
1953 | if (rc) { | |
1954 | ecryptfs_printk(KERN_ERR, "Error initializing crypto " | |
1955 | "context for cipher [%s]; rc = [%d]\n", | |
1956 | crypt_stat->cipher, rc); | |
1957 | } | |
1958 | out_wipe_list: | |
1959 | wipe_auth_tok_list(&auth_tok_list); | |
1960 | out: | |
1961 | return rc; | |
1962 | } | |
f4aad16a | 1963 | |
dddfa461 | 1964 | static int |
b2987a5e TH |
1965 | pki_encrypt_session_key(struct key *auth_tok_key, |
1966 | struct ecryptfs_auth_tok *auth_tok, | |
dddfa461 MH |
1967 | struct ecryptfs_crypt_stat *crypt_stat, |
1968 | struct ecryptfs_key_record *key_rec) | |
1969 | { | |
1970 | struct ecryptfs_msg_ctx *msg_ctx = NULL; | |
624ae528 | 1971 | char *payload = NULL; |
99b373ff | 1972 | size_t payload_len = 0; |
dddfa461 MH |
1973 | struct ecryptfs_message *msg; |
1974 | int rc; | |
1975 | ||
1976 | rc = write_tag_66_packet(auth_tok->token.private_key.signature, | |
9c79f34f MH |
1977 | ecryptfs_code_for_cipher_string( |
1978 | crypt_stat->cipher, | |
1979 | crypt_stat->key_size), | |
624ae528 | 1980 | crypt_stat, &payload, &payload_len); |
b2987a5e TH |
1981 | up_write(&(auth_tok_key->sem)); |
1982 | key_put(auth_tok_key); | |
dddfa461 MH |
1983 | if (rc) { |
1984 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n"); | |
1985 | goto out; | |
1986 | } | |
624ae528 | 1987 | rc = ecryptfs_send_message(payload, payload_len, &msg_ctx); |
dddfa461 | 1988 | if (rc) { |
624ae528 | 1989 | ecryptfs_printk(KERN_ERR, "Error sending message to " |
290502be | 1990 | "ecryptfsd: %d\n", rc); |
dddfa461 MH |
1991 | goto out; |
1992 | } | |
1993 | rc = ecryptfs_wait_for_response(msg_ctx, &msg); | |
1994 | if (rc) { | |
1995 | ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet " | |
1996 | "from the user space daemon\n"); | |
1997 | rc = -EIO; | |
1998 | goto out; | |
1999 | } | |
2000 | rc = parse_tag_67_packet(key_rec, msg); | |
2001 | if (rc) | |
2002 | ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n"); | |
2003 | kfree(msg); | |
2004 | out: | |
624ae528 | 2005 | kfree(payload); |
dddfa461 MH |
2006 | return rc; |
2007 | } | |
2008 | /** | |
2009 | * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet | |
2010 | * @dest: Buffer into which to write the packet | |
22e78faf | 2011 | * @remaining_bytes: Maximum number of bytes that can be writtn |
b2987a5e TH |
2012 | * @auth_tok_key: The authentication token key to unlock and put when done with |
2013 | * @auth_tok | |
22e78faf MH |
2014 | * @auth_tok: The authentication token used for generating the tag 1 packet |
2015 | * @crypt_stat: The cryptographic context | |
2016 | * @key_rec: The key record struct for the tag 1 packet | |
dddfa461 MH |
2017 | * @packet_size: This function will write the number of bytes that end |
2018 | * up constituting the packet; set to zero on error | |
2019 | * | |
2020 | * Returns zero on success; non-zero on error. | |
2021 | */ | |
2022 | static int | |
f4aad16a | 2023 | write_tag_1_packet(char *dest, size_t *remaining_bytes, |
b2987a5e | 2024 | struct key *auth_tok_key, struct ecryptfs_auth_tok *auth_tok, |
dddfa461 | 2025 | struct ecryptfs_crypt_stat *crypt_stat, |
dddfa461 MH |
2026 | struct ecryptfs_key_record *key_rec, size_t *packet_size) |
2027 | { | |
2028 | size_t i; | |
2029 | size_t encrypted_session_key_valid = 0; | |
dddfa461 | 2030 | size_t packet_size_length; |
f4aad16a | 2031 | size_t max_packet_size; |
dddfa461 MH |
2032 | int rc = 0; |
2033 | ||
2034 | (*packet_size) = 0; | |
2035 | ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature, | |
2036 | ECRYPTFS_SIG_SIZE); | |
2037 | encrypted_session_key_valid = 0; | |
2038 | for (i = 0; i < crypt_stat->key_size; i++) | |
2039 | encrypted_session_key_valid |= | |
2040 | auth_tok->session_key.encrypted_key[i]; | |
2041 | if (encrypted_session_key_valid) { | |
2042 | memcpy(key_rec->enc_key, | |
2043 | auth_tok->session_key.encrypted_key, | |
2044 | auth_tok->session_key.encrypted_key_size); | |
b2987a5e TH |
2045 | up_write(&(auth_tok_key->sem)); |
2046 | key_put(auth_tok_key); | |
dddfa461 MH |
2047 | goto encrypted_session_key_set; |
2048 | } | |
2049 | if (auth_tok->session_key.encrypted_key_size == 0) | |
2050 | auth_tok->session_key.encrypted_key_size = | |
2051 | auth_tok->token.private_key.key_size; | |
b2987a5e TH |
2052 | rc = pki_encrypt_session_key(auth_tok_key, auth_tok, crypt_stat, |
2053 | key_rec); | |
dddfa461 | 2054 | if (rc) { |
f66e883e MH |
2055 | printk(KERN_ERR "Failed to encrypt session key via a key " |
2056 | "module; rc = [%d]\n", rc); | |
dddfa461 MH |
2057 | goto out; |
2058 | } | |
2059 | if (ecryptfs_verbosity > 0) { | |
2060 | ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n"); | |
2061 | ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size); | |
2062 | } | |
2063 | encrypted_session_key_set: | |
f4aad16a MH |
2064 | /* This format is inspired by OpenPGP; see RFC 2440 |
2065 | * packet tag 1 */ | |
2066 | max_packet_size = (1 /* Tag 1 identifier */ | |
2067 | + 3 /* Max Tag 1 packet size */ | |
2068 | + 1 /* Version */ | |
2069 | + ECRYPTFS_SIG_SIZE /* Key identifier */ | |
2070 | + 1 /* Cipher identifier */ | |
2071 | + key_rec->enc_key_size); /* Encrypted key size */ | |
2072 | if (max_packet_size > (*remaining_bytes)) { | |
2073 | printk(KERN_ERR "Packet length larger than maximum allowable; " | |
81acbcd6 | 2074 | "need up to [%td] bytes, but there are only [%td] " |
f4aad16a | 2075 | "available\n", max_packet_size, (*remaining_bytes)); |
dddfa461 MH |
2076 | rc = -EINVAL; |
2077 | goto out; | |
2078 | } | |
2079 | dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE; | |
f66e883e MH |
2080 | rc = ecryptfs_write_packet_length(&dest[(*packet_size)], |
2081 | (max_packet_size - 4), | |
2082 | &packet_size_length); | |
dddfa461 MH |
2083 | if (rc) { |
2084 | ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet " | |
2085 | "header; cannot generate packet length\n"); | |
2086 | goto out; | |
2087 | } | |
2088 | (*packet_size) += packet_size_length; | |
2089 | dest[(*packet_size)++] = 0x03; /* version 3 */ | |
2090 | memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE); | |
2091 | (*packet_size) += ECRYPTFS_SIG_SIZE; | |
2092 | dest[(*packet_size)++] = RFC2440_CIPHER_RSA; | |
2093 | memcpy(&dest[(*packet_size)], key_rec->enc_key, | |
2094 | key_rec->enc_key_size); | |
2095 | (*packet_size) += key_rec->enc_key_size; | |
2096 | out: | |
2097 | if (rc) | |
2098 | (*packet_size) = 0; | |
f4aad16a MH |
2099 | else |
2100 | (*remaining_bytes) -= (*packet_size); | |
dddfa461 MH |
2101 | return rc; |
2102 | } | |
237fead6 MH |
2103 | |
2104 | /** | |
2105 | * write_tag_11_packet | |
2106 | * @dest: Target into which Tag 11 packet is to be written | |
22e78faf | 2107 | * @remaining_bytes: Maximum packet length |
237fead6 MH |
2108 | * @contents: Byte array of contents to copy in |
2109 | * @contents_length: Number of bytes in contents | |
2110 | * @packet_length: Length of the Tag 11 packet written; zero on error | |
2111 | * | |
2112 | * Returns zero on success; non-zero on error. | |
2113 | */ | |
2114 | static int | |
81acbcd6 | 2115 | write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents, |
146a4606 | 2116 | size_t contents_length, size_t *packet_length) |
237fead6 | 2117 | { |
237fead6 | 2118 | size_t packet_size_length; |
146a4606 | 2119 | size_t max_packet_size; |
dddfa461 | 2120 | int rc = 0; |
237fead6 MH |
2121 | |
2122 | (*packet_length) = 0; | |
146a4606 MH |
2123 | /* This format is inspired by OpenPGP; see RFC 2440 |
2124 | * packet tag 11 */ | |
2125 | max_packet_size = (1 /* Tag 11 identifier */ | |
2126 | + 3 /* Max Tag 11 packet size */ | |
2127 | + 1 /* Binary format specifier */ | |
2128 | + 1 /* Filename length */ | |
2129 | + 8 /* Filename ("_CONSOLE") */ | |
2130 | + 4 /* Modification date */ | |
2131 | + contents_length); /* Literal data */ | |
2132 | if (max_packet_size > (*remaining_bytes)) { | |
2133 | printk(KERN_ERR "Packet length larger than maximum allowable; " | |
81acbcd6 | 2134 | "need up to [%td] bytes, but there are only [%td] " |
146a4606 | 2135 | "available\n", max_packet_size, (*remaining_bytes)); |
237fead6 | 2136 | rc = -EINVAL; |
237fead6 MH |
2137 | goto out; |
2138 | } | |
237fead6 | 2139 | dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE; |
f66e883e MH |
2140 | rc = ecryptfs_write_packet_length(&dest[(*packet_length)], |
2141 | (max_packet_size - 4), | |
2142 | &packet_size_length); | |
237fead6 | 2143 | if (rc) { |
146a4606 MH |
2144 | printk(KERN_ERR "Error generating tag 11 packet header; cannot " |
2145 | "generate packet length. rc = [%d]\n", rc); | |
237fead6 MH |
2146 | goto out; |
2147 | } | |
2148 | (*packet_length) += packet_size_length; | |
146a4606 | 2149 | dest[(*packet_length)++] = 0x62; /* binary data format specifier */ |
237fead6 MH |
2150 | dest[(*packet_length)++] = 8; |
2151 | memcpy(&dest[(*packet_length)], "_CONSOLE", 8); | |
2152 | (*packet_length) += 8; | |
237fead6 MH |
2153 | memset(&dest[(*packet_length)], 0x00, 4); |
2154 | (*packet_length) += 4; | |
237fead6 MH |
2155 | memcpy(&dest[(*packet_length)], contents, contents_length); |
2156 | (*packet_length) += contents_length; | |
2157 | out: | |
2158 | if (rc) | |
2159 | (*packet_length) = 0; | |
146a4606 MH |
2160 | else |
2161 | (*remaining_bytes) -= (*packet_length); | |
237fead6 MH |
2162 | return rc; |
2163 | } | |
2164 | ||
2165 | /** | |
2166 | * write_tag_3_packet | |
2167 | * @dest: Buffer into which to write the packet | |
22e78faf | 2168 | * @remaining_bytes: Maximum number of bytes that can be written |
237fead6 MH |
2169 | * @auth_tok: Authentication token |
2170 | * @crypt_stat: The cryptographic context | |
2171 | * @key_rec: encrypted key | |
2172 | * @packet_size: This function will write the number of bytes that end | |
2173 | * up constituting the packet; set to zero on error | |
2174 | * | |
2175 | * Returns zero on success; non-zero on error. | |
2176 | */ | |
2177 | static int | |
f4aad16a MH |
2178 | write_tag_3_packet(char *dest, size_t *remaining_bytes, |
2179 | struct ecryptfs_auth_tok *auth_tok, | |
237fead6 MH |
2180 | struct ecryptfs_crypt_stat *crypt_stat, |
2181 | struct ecryptfs_key_record *key_rec, size_t *packet_size) | |
2182 | { | |
237fead6 | 2183 | size_t i; |
237fead6 MH |
2184 | size_t encrypted_session_key_valid = 0; |
2185 | char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES]; | |
ac97b9f9 MH |
2186 | struct scatterlist dst_sg[2]; |
2187 | struct scatterlist src_sg[2]; | |
237fead6 | 2188 | struct mutex *tfm_mutex = NULL; |
19e66a67 | 2189 | u8 cipher_code; |
f4aad16a MH |
2190 | size_t packet_size_length; |
2191 | size_t max_packet_size; | |
2192 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = | |
2193 | crypt_stat->mount_crypt_stat; | |
8bba066f MH |
2194 | struct blkcipher_desc desc = { |
2195 | .tfm = NULL, | |
2196 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
2197 | }; | |
2198 | int rc = 0; | |
237fead6 MH |
2199 | |
2200 | (*packet_size) = 0; | |
dddfa461 | 2201 | ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature, |
237fead6 | 2202 | ECRYPTFS_SIG_SIZE); |
f4aad16a MH |
2203 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex, |
2204 | crypt_stat->cipher); | |
2205 | if (unlikely(rc)) { | |
2206 | printk(KERN_ERR "Internal error whilst attempting to get " | |
2207 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
2208 | crypt_stat->cipher, rc); | |
2209 | goto out; | |
2210 | } | |
2211 | if (mount_crypt_stat->global_default_cipher_key_size == 0) { | |
2212 | struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm); | |
2213 | ||
2214 | printk(KERN_WARNING "No key size specified at mount; " | |
2215 | "defaulting to [%d]\n", alg->max_keysize); | |
2216 | mount_crypt_stat->global_default_cipher_key_size = | |
2217 | alg->max_keysize; | |
237fead6 | 2218 | } |
f4aad16a MH |
2219 | if (crypt_stat->key_size == 0) |
2220 | crypt_stat->key_size = | |
2221 | mount_crypt_stat->global_default_cipher_key_size; | |
237fead6 MH |
2222 | if (auth_tok->session_key.encrypted_key_size == 0) |
2223 | auth_tok->session_key.encrypted_key_size = | |
2224 | crypt_stat->key_size; | |
2225 | if (crypt_stat->key_size == 24 | |
2226 | && strcmp("aes", crypt_stat->cipher) == 0) { | |
2227 | memset((crypt_stat->key + 24), 0, 8); | |
2228 | auth_tok->session_key.encrypted_key_size = 32; | |
f4aad16a MH |
2229 | } else |
2230 | auth_tok->session_key.encrypted_key_size = crypt_stat->key_size; | |
dddfa461 | 2231 | key_rec->enc_key_size = |
237fead6 | 2232 | auth_tok->session_key.encrypted_key_size; |
f4aad16a MH |
2233 | encrypted_session_key_valid = 0; |
2234 | for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++) | |
2235 | encrypted_session_key_valid |= | |
2236 | auth_tok->session_key.encrypted_key[i]; | |
2237 | if (encrypted_session_key_valid) { | |
2238 | ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; " | |
2239 | "using auth_tok->session_key.encrypted_key, " | |
f24b3887 | 2240 | "where key_rec->enc_key_size = [%zd]\n", |
f4aad16a MH |
2241 | key_rec->enc_key_size); |
2242 | memcpy(key_rec->enc_key, | |
2243 | auth_tok->session_key.encrypted_key, | |
2244 | key_rec->enc_key_size); | |
2245 | goto encrypted_session_key_set; | |
2246 | } | |
dddfa461 MH |
2247 | if (auth_tok->token.password.flags & |
2248 | ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) { | |
237fead6 MH |
2249 | ecryptfs_printk(KERN_DEBUG, "Using previously generated " |
2250 | "session key encryption key of size [%d]\n", | |
2251 | auth_tok->token.password. | |
2252 | session_key_encryption_key_bytes); | |
2253 | memcpy(session_key_encryption_key, | |
2254 | auth_tok->token.password.session_key_encryption_key, | |
2255 | crypt_stat->key_size); | |
2256 | ecryptfs_printk(KERN_DEBUG, | |
df2e301f | 2257 | "Cached session key encryption key:\n"); |
237fead6 MH |
2258 | if (ecryptfs_verbosity > 0) |
2259 | ecryptfs_dump_hex(session_key_encryption_key, 16); | |
2260 | } | |
2261 | if (unlikely(ecryptfs_verbosity > 0)) { | |
2262 | ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n"); | |
2263 | ecryptfs_dump_hex(session_key_encryption_key, 16); | |
2264 | } | |
5dda6992 | 2265 | rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size, |
ac97b9f9 MH |
2266 | src_sg, 2); |
2267 | if (rc < 1 || rc > 2) { | |
237fead6 | 2268 | ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
f4aad16a | 2269 | "for crypt_stat session key; expected rc = 1; " |
f24b3887 | 2270 | "got rc = [%d]. key_rec->enc_key_size = [%zd]\n", |
f4aad16a | 2271 | rc, key_rec->enc_key_size); |
237fead6 MH |
2272 | rc = -ENOMEM; |
2273 | goto out; | |
2274 | } | |
5dda6992 | 2275 | rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size, |
ac97b9f9 MH |
2276 | dst_sg, 2); |
2277 | if (rc < 1 || rc > 2) { | |
237fead6 | 2278 | ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
f4aad16a MH |
2279 | "for crypt_stat encrypted session key; " |
2280 | "expected rc = 1; got rc = [%d]. " | |
f24b3887 | 2281 | "key_rec->enc_key_size = [%zd]\n", rc, |
f4aad16a | 2282 | key_rec->enc_key_size); |
237fead6 MH |
2283 | rc = -ENOMEM; |
2284 | goto out; | |
2285 | } | |
f4aad16a | 2286 | mutex_lock(tfm_mutex); |
8bba066f MH |
2287 | rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key, |
2288 | crypt_stat->key_size); | |
237fead6 | 2289 | if (rc < 0) { |
f4aad16a | 2290 | mutex_unlock(tfm_mutex); |
237fead6 | 2291 | ecryptfs_printk(KERN_ERR, "Error setting key for crypto " |
8bba066f | 2292 | "context; rc = [%d]\n", rc); |
237fead6 MH |
2293 | goto out; |
2294 | } | |
2295 | rc = 0; | |
f24b3887 | 2296 | ecryptfs_printk(KERN_DEBUG, "Encrypting [%zd] bytes of the key\n", |
237fead6 | 2297 | crypt_stat->key_size); |
ac97b9f9 | 2298 | rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg, |
8bba066f | 2299 | (*key_rec).enc_key_size); |
f4aad16a | 2300 | mutex_unlock(tfm_mutex); |
8bba066f MH |
2301 | if (rc) { |
2302 | printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc); | |
2303 | goto out; | |
2304 | } | |
237fead6 | 2305 | ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n"); |
f4aad16a | 2306 | if (ecryptfs_verbosity > 0) { |
f24b3887 | 2307 | ecryptfs_printk(KERN_DEBUG, "EFEK of size [%zd]:\n", |
f4aad16a | 2308 | key_rec->enc_key_size); |
dddfa461 MH |
2309 | ecryptfs_dump_hex(key_rec->enc_key, |
2310 | key_rec->enc_key_size); | |
237fead6 | 2311 | } |
f4aad16a MH |
2312 | encrypted_session_key_set: |
2313 | /* This format is inspired by OpenPGP; see RFC 2440 | |
2314 | * packet tag 3 */ | |
2315 | max_packet_size = (1 /* Tag 3 identifier */ | |
2316 | + 3 /* Max Tag 3 packet size */ | |
2317 | + 1 /* Version */ | |
2318 | + 1 /* Cipher code */ | |
2319 | + 1 /* S2K specifier */ | |
2320 | + 1 /* Hash identifier */ | |
2321 | + ECRYPTFS_SALT_SIZE /* Salt */ | |
2322 | + 1 /* Hash iterations */ | |
2323 | + key_rec->enc_key_size); /* Encrypted key size */ | |
2324 | if (max_packet_size > (*remaining_bytes)) { | |
81acbcd6 AM |
2325 | printk(KERN_ERR "Packet too large; need up to [%td] bytes, but " |
2326 | "there are only [%td] available\n", max_packet_size, | |
f4aad16a | 2327 | (*remaining_bytes)); |
237fead6 MH |
2328 | rc = -EINVAL; |
2329 | goto out; | |
2330 | } | |
237fead6 | 2331 | dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE; |
f4aad16a MH |
2332 | /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3) |
2333 | * to get the number of octets in the actual Tag 3 packet */ | |
f66e883e MH |
2334 | rc = ecryptfs_write_packet_length(&dest[(*packet_size)], |
2335 | (max_packet_size - 4), | |
2336 | &packet_size_length); | |
237fead6 | 2337 | if (rc) { |
f4aad16a MH |
2338 | printk(KERN_ERR "Error generating tag 3 packet header; cannot " |
2339 | "generate packet length. rc = [%d]\n", rc); | |
237fead6 MH |
2340 | goto out; |
2341 | } | |
2342 | (*packet_size) += packet_size_length; | |
2343 | dest[(*packet_size)++] = 0x04; /* version 4 */ | |
f4aad16a MH |
2344 | /* TODO: Break from RFC2440 so that arbitrary ciphers can be |
2345 | * specified with strings */ | |
9c79f34f MH |
2346 | cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher, |
2347 | crypt_stat->key_size); | |
237fead6 MH |
2348 | if (cipher_code == 0) { |
2349 | ecryptfs_printk(KERN_WARNING, "Unable to generate code for " | |
2350 | "cipher [%s]\n", crypt_stat->cipher); | |
2351 | rc = -EINVAL; | |
2352 | goto out; | |
2353 | } | |
2354 | dest[(*packet_size)++] = cipher_code; | |
2355 | dest[(*packet_size)++] = 0x03; /* S2K */ | |
2356 | dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */ | |
2357 | memcpy(&dest[(*packet_size)], auth_tok->token.password.salt, | |
2358 | ECRYPTFS_SALT_SIZE); | |
2359 | (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */ | |
2360 | dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */ | |
dddfa461 MH |
2361 | memcpy(&dest[(*packet_size)], key_rec->enc_key, |
2362 | key_rec->enc_key_size); | |
2363 | (*packet_size) += key_rec->enc_key_size; | |
237fead6 | 2364 | out: |
237fead6 MH |
2365 | if (rc) |
2366 | (*packet_size) = 0; | |
f4aad16a MH |
2367 | else |
2368 | (*remaining_bytes) -= (*packet_size); | |
237fead6 MH |
2369 | return rc; |
2370 | } | |
2371 | ||
eb95e7ff MH |
2372 | struct kmem_cache *ecryptfs_key_record_cache; |
2373 | ||
237fead6 MH |
2374 | /** |
2375 | * ecryptfs_generate_key_packet_set | |
22e78faf | 2376 | * @dest_base: Virtual address from which to write the key record set |
237fead6 MH |
2377 | * @crypt_stat: The cryptographic context from which the |
2378 | * authentication tokens will be retrieved | |
2379 | * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat | |
2380 | * for the global parameters | |
2381 | * @len: The amount written | |
2382 | * @max: The maximum amount of data allowed to be written | |
2383 | * | |
2384 | * Generates a key packet set and writes it to the virtual address | |
2385 | * passed in. | |
2386 | * | |
2387 | * Returns zero on success; non-zero on error. | |
2388 | */ | |
2389 | int | |
2390 | ecryptfs_generate_key_packet_set(char *dest_base, | |
2391 | struct ecryptfs_crypt_stat *crypt_stat, | |
2392 | struct dentry *ecryptfs_dentry, size_t *len, | |
2393 | size_t max) | |
2394 | { | |
237fead6 | 2395 | struct ecryptfs_auth_tok *auth_tok; |
0e1fc5ef | 2396 | struct key *auth_tok_key = NULL; |
237fead6 MH |
2397 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
2398 | &ecryptfs_superblock_to_private( | |
2399 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
2400 | size_t written; | |
eb95e7ff | 2401 | struct ecryptfs_key_record *key_rec; |
f4aad16a | 2402 | struct ecryptfs_key_sig *key_sig; |
dddfa461 | 2403 | int rc = 0; |
237fead6 MH |
2404 | |
2405 | (*len) = 0; | |
f4aad16a | 2406 | mutex_lock(&crypt_stat->keysig_list_mutex); |
eb95e7ff MH |
2407 | key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL); |
2408 | if (!key_rec) { | |
2409 | rc = -ENOMEM; | |
2410 | goto out; | |
2411 | } | |
f4aad16a MH |
2412 | list_for_each_entry(key_sig, &crypt_stat->keysig_list, |
2413 | crypt_stat_list) { | |
2414 | memset(key_rec, 0, sizeof(*key_rec)); | |
0e1fc5ef RS |
2415 | rc = ecryptfs_find_global_auth_tok_for_sig(&auth_tok_key, |
2416 | &auth_tok, | |
f4aad16a MH |
2417 | mount_crypt_stat, |
2418 | key_sig->keysig); | |
2419 | if (rc) { | |
0e1fc5ef RS |
2420 | printk(KERN_WARNING "Unable to retrieve auth tok with " |
2421 | "sig = [%s]\n", key_sig->keysig); | |
2422 | rc = process_find_global_auth_tok_for_sig_err(rc); | |
f4aad16a MH |
2423 | goto out_free; |
2424 | } | |
237fead6 MH |
2425 | if (auth_tok->token_type == ECRYPTFS_PASSWORD) { |
2426 | rc = write_tag_3_packet((dest_base + (*len)), | |
f4aad16a | 2427 | &max, auth_tok, |
eb95e7ff | 2428 | crypt_stat, key_rec, |
237fead6 | 2429 | &written); |
b2987a5e TH |
2430 | up_write(&(auth_tok_key->sem)); |
2431 | key_put(auth_tok_key); | |
237fead6 MH |
2432 | if (rc) { |
2433 | ecryptfs_printk(KERN_WARNING, "Error " | |
2434 | "writing tag 3 packet\n"); | |
eb95e7ff | 2435 | goto out_free; |
237fead6 MH |
2436 | } |
2437 | (*len) += written; | |
2438 | /* Write auth tok signature packet */ | |
f4aad16a MH |
2439 | rc = write_tag_11_packet((dest_base + (*len)), &max, |
2440 | key_rec->sig, | |
2441 | ECRYPTFS_SIG_SIZE, &written); | |
237fead6 MH |
2442 | if (rc) { |
2443 | ecryptfs_printk(KERN_ERR, "Error writing " | |
2444 | "auth tok signature packet\n"); | |
eb95e7ff | 2445 | goto out_free; |
237fead6 MH |
2446 | } |
2447 | (*len) += written; | |
dddfa461 | 2448 | } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
b2987a5e TH |
2449 | rc = write_tag_1_packet(dest_base + (*len), &max, |
2450 | auth_tok_key, auth_tok, | |
f4aad16a | 2451 | crypt_stat, key_rec, &written); |
dddfa461 MH |
2452 | if (rc) { |
2453 | ecryptfs_printk(KERN_WARNING, "Error " | |
2454 | "writing tag 1 packet\n"); | |
eb95e7ff | 2455 | goto out_free; |
dddfa461 MH |
2456 | } |
2457 | (*len) += written; | |
237fead6 | 2458 | } else { |
b2987a5e TH |
2459 | up_write(&(auth_tok_key->sem)); |
2460 | key_put(auth_tok_key); | |
237fead6 MH |
2461 | ecryptfs_printk(KERN_WARNING, "Unsupported " |
2462 | "authentication token type\n"); | |
2463 | rc = -EINVAL; | |
eb95e7ff | 2464 | goto out_free; |
237fead6 | 2465 | } |
f4aad16a MH |
2466 | } |
2467 | if (likely(max > 0)) { | |
237fead6 MH |
2468 | dest_base[(*len)] = 0x00; |
2469 | } else { | |
2470 | ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n"); | |
2471 | rc = -EIO; | |
2472 | } | |
eb95e7ff MH |
2473 | out_free: |
2474 | kmem_cache_free(ecryptfs_key_record_cache, key_rec); | |
237fead6 MH |
2475 | out: |
2476 | if (rc) | |
2477 | (*len) = 0; | |
f4aad16a MH |
2478 | mutex_unlock(&crypt_stat->keysig_list_mutex); |
2479 | return rc; | |
2480 | } | |
2481 | ||
2482 | struct kmem_cache *ecryptfs_key_sig_cache; | |
2483 | ||
2484 | int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig) | |
2485 | { | |
2486 | struct ecryptfs_key_sig *new_key_sig; | |
f4aad16a MH |
2487 | |
2488 | new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL); | |
2489 | if (!new_key_sig) { | |
f4aad16a MH |
2490 | printk(KERN_ERR |
2491 | "Error allocating from ecryptfs_key_sig_cache\n"); | |
aa06117f | 2492 | return -ENOMEM; |
f4aad16a MH |
2493 | } |
2494 | memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX); | |
7762e230 | 2495 | new_key_sig->keysig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
aa06117f | 2496 | /* Caller must hold keysig_list_mutex */ |
f4aad16a | 2497 | list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list); |
aa06117f RD |
2498 | |
2499 | return 0; | |
237fead6 | 2500 | } |
f4aad16a MH |
2501 | |
2502 | struct kmem_cache *ecryptfs_global_auth_tok_cache; | |
2503 | ||
2504 | int | |
2505 | ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
84814d64 | 2506 | char *sig, u32 global_auth_tok_flags) |
f4aad16a MH |
2507 | { |
2508 | struct ecryptfs_global_auth_tok *new_auth_tok; | |
2509 | int rc = 0; | |
2510 | ||
459e2164 | 2511 | new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache, |
f4aad16a MH |
2512 | GFP_KERNEL); |
2513 | if (!new_auth_tok) { | |
2514 | rc = -ENOMEM; | |
2515 | printk(KERN_ERR "Error allocating from " | |
2516 | "ecryptfs_global_auth_tok_cache\n"); | |
2517 | goto out; | |
2518 | } | |
2519 | memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX); | |
84814d64 | 2520 | new_auth_tok->flags = global_auth_tok_flags; |
f4aad16a MH |
2521 | new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
2522 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
2523 | list_add(&new_auth_tok->mount_crypt_stat_list, | |
2524 | &mount_crypt_stat->global_auth_tok_list); | |
f4aad16a MH |
2525 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); |
2526 | out: | |
2527 | return rc; | |
2528 | } | |
2529 |