Commit | Line | Data |
---|---|---|
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 | ||
3095e8e3 HX |
28 | #include <crypto/hash.h> |
29 | #include <crypto/skcipher.h> | |
237fead6 | 30 | #include <linux/string.h> |
237fead6 MH |
31 | #include <linux/pagemap.h> |
32 | #include <linux/key.h> | |
33 | #include <linux/random.h> | |
237fead6 | 34 | #include <linux/scatterlist.h> |
5a0e3ad6 | 35 | #include <linux/slab.h> |
237fead6 MH |
36 | #include "ecryptfs_kernel.h" |
37 | ||
38 | /** | |
39 | * request_key returned an error instead of a valid key address; | |
40 | * determine the type of error, make appropriate log entries, and | |
41 | * return an error code. | |
42 | */ | |
cd9d67df | 43 | static int process_request_key_err(long err_code) |
237fead6 MH |
44 | { |
45 | int rc = 0; | |
46 | ||
47 | switch (err_code) { | |
982363c9 | 48 | case -ENOKEY: |
237fead6 MH |
49 | ecryptfs_printk(KERN_WARNING, "No key\n"); |
50 | rc = -ENOENT; | |
51 | break; | |
982363c9 | 52 | case -EKEYEXPIRED: |
237fead6 MH |
53 | ecryptfs_printk(KERN_WARNING, "Key expired\n"); |
54 | rc = -ETIME; | |
55 | break; | |
982363c9 | 56 | case -EKEYREVOKED: |
237fead6 MH |
57 | ecryptfs_printk(KERN_WARNING, "Key revoked\n"); |
58 | rc = -EINVAL; | |
59 | break; | |
60 | default: | |
61 | ecryptfs_printk(KERN_WARNING, "Unknown error code: " | |
888d57bb | 62 | "[0x%.16lx]\n", err_code); |
237fead6 MH |
63 | rc = -EINVAL; |
64 | } | |
65 | return rc; | |
66 | } | |
67 | ||
0e1fc5ef RS |
68 | static int process_find_global_auth_tok_for_sig_err(int err_code) |
69 | { | |
70 | int rc = err_code; | |
71 | ||
72 | switch (err_code) { | |
73 | case -ENOENT: | |
74 | ecryptfs_printk(KERN_WARNING, "Missing auth tok\n"); | |
75 | break; | |
76 | case -EINVAL: | |
77 | ecryptfs_printk(KERN_WARNING, "Invalid auth tok\n"); | |
78 | break; | |
79 | default: | |
80 | rc = process_request_key_err(err_code); | |
81 | break; | |
82 | } | |
83 | return rc; | |
84 | } | |
85 | ||
237fead6 | 86 | /** |
f66e883e | 87 | * ecryptfs_parse_packet_length |
237fead6 MH |
88 | * @data: Pointer to memory containing length at offset |
89 | * @size: This function writes the decoded size to this memory | |
90 | * address; zero on error | |
91 | * @length_size: The number of bytes occupied by the encoded length | |
92 | * | |
22e78faf | 93 | * Returns zero on success; non-zero on error |
237fead6 | 94 | */ |
f66e883e MH |
95 | int ecryptfs_parse_packet_length(unsigned char *data, size_t *size, |
96 | size_t *length_size) | |
237fead6 MH |
97 | { |
98 | int rc = 0; | |
99 | ||
100 | (*length_size) = 0; | |
101 | (*size) = 0; | |
102 | if (data[0] < 192) { | |
103 | /* One-byte length */ | |
831115af | 104 | (*size) = data[0]; |
237fead6 MH |
105 | (*length_size) = 1; |
106 | } else if (data[0] < 224) { | |
107 | /* Two-byte length */ | |
831115af TH |
108 | (*size) = (data[0] - 192) * 256; |
109 | (*size) += data[1] + 192; | |
237fead6 MH |
110 | (*length_size) = 2; |
111 | } else if (data[0] == 255) { | |
48399c0b | 112 | /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */ |
237fead6 MH |
113 | ecryptfs_printk(KERN_ERR, "Five-byte packet length not " |
114 | "supported\n"); | |
115 | rc = -EINVAL; | |
116 | goto out; | |
117 | } else { | |
118 | ecryptfs_printk(KERN_ERR, "Error parsing packet length\n"); | |
119 | rc = -EINVAL; | |
120 | goto out; | |
121 | } | |
122 | out: | |
123 | return rc; | |
124 | } | |
125 | ||
126 | /** | |
f66e883e | 127 | * ecryptfs_write_packet_length |
22e78faf | 128 | * @dest: The byte array target into which to write the length. Must |
48399c0b | 129 | * have at least ECRYPTFS_MAX_PKT_LEN_SIZE bytes allocated. |
237fead6 | 130 | * @size: The length to write. |
22e78faf MH |
131 | * @packet_size_length: The number of bytes used to encode the packet |
132 | * length is written to this address. | |
237fead6 MH |
133 | * |
134 | * Returns zero on success; non-zero on error. | |
135 | */ | |
f66e883e MH |
136 | int ecryptfs_write_packet_length(char *dest, size_t size, |
137 | size_t *packet_size_length) | |
237fead6 MH |
138 | { |
139 | int rc = 0; | |
140 | ||
141 | if (size < 192) { | |
142 | dest[0] = size; | |
143 | (*packet_size_length) = 1; | |
144 | } else if (size < 65536) { | |
145 | dest[0] = (((size - 192) / 256) + 192); | |
146 | dest[1] = ((size - 192) % 256); | |
147 | (*packet_size_length) = 2; | |
148 | } else { | |
48399c0b | 149 | /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */ |
237fead6 MH |
150 | rc = -EINVAL; |
151 | ecryptfs_printk(KERN_WARNING, | |
f24b3887 | 152 | "Unsupported packet size: [%zd]\n", size); |
237fead6 MH |
153 | } |
154 | return rc; | |
155 | } | |
156 | ||
dddfa461 MH |
157 | static int |
158 | write_tag_64_packet(char *signature, struct ecryptfs_session_key *session_key, | |
159 | char **packet, size_t *packet_len) | |
160 | { | |
161 | size_t i = 0; | |
162 | size_t data_len; | |
163 | size_t packet_size_len; | |
164 | char *message; | |
165 | int rc; | |
166 | ||
167 | /* | |
168 | * ***** TAG 64 Packet Format ***** | |
169 | * | Content Type | 1 byte | | |
170 | * | Key Identifier Size | 1 or 2 bytes | | |
171 | * | Key Identifier | arbitrary | | |
172 | * | Encrypted File Encryption Key Size | 1 or 2 bytes | | |
173 | * | Encrypted File Encryption Key | arbitrary | | |
174 | */ | |
175 | data_len = (5 + ECRYPTFS_SIG_SIZE_HEX | |
176 | + session_key->encrypted_key_size); | |
177 | *packet = kmalloc(data_len, GFP_KERNEL); | |
178 | message = *packet; | |
179 | if (!message) { | |
180 | ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n"); | |
181 | rc = -ENOMEM; | |
182 | goto out; | |
183 | } | |
184 | message[i++] = ECRYPTFS_TAG_64_PACKET_TYPE; | |
f66e883e MH |
185 | rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX, |
186 | &packet_size_len); | |
dddfa461 MH |
187 | if (rc) { |
188 | ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet " | |
189 | "header; cannot generate packet length\n"); | |
190 | goto out; | |
191 | } | |
192 | i += packet_size_len; | |
193 | memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX); | |
194 | i += ECRYPTFS_SIG_SIZE_HEX; | |
f66e883e MH |
195 | rc = ecryptfs_write_packet_length(&message[i], |
196 | session_key->encrypted_key_size, | |
197 | &packet_size_len); | |
dddfa461 MH |
198 | if (rc) { |
199 | ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet " | |
200 | "header; cannot generate packet length\n"); | |
201 | goto out; | |
202 | } | |
203 | i += packet_size_len; | |
204 | memcpy(&message[i], session_key->encrypted_key, | |
205 | session_key->encrypted_key_size); | |
206 | i += session_key->encrypted_key_size; | |
207 | *packet_len = i; | |
208 | out: | |
209 | return rc; | |
210 | } | |
211 | ||
212 | static int | |
19e66a67 | 213 | parse_tag_65_packet(struct ecryptfs_session_key *session_key, u8 *cipher_code, |
dddfa461 MH |
214 | struct ecryptfs_message *msg) |
215 | { | |
216 | size_t i = 0; | |
217 | char *data; | |
218 | size_t data_len; | |
219 | size_t m_size; | |
220 | size_t message_len; | |
221 | u16 checksum = 0; | |
222 | u16 expected_checksum = 0; | |
223 | int rc; | |
224 | ||
225 | /* | |
226 | * ***** TAG 65 Packet Format ***** | |
227 | * | Content Type | 1 byte | | |
228 | * | Status Indicator | 1 byte | | |
229 | * | File Encryption Key Size | 1 or 2 bytes | | |
230 | * | File Encryption Key | arbitrary | | |
231 | */ | |
232 | message_len = msg->data_len; | |
233 | data = msg->data; | |
234 | if (message_len < 4) { | |
235 | rc = -EIO; | |
236 | goto out; | |
237 | } | |
238 | if (data[i++] != ECRYPTFS_TAG_65_PACKET_TYPE) { | |
239 | ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_65\n"); | |
240 | rc = -EIO; | |
241 | goto out; | |
242 | } | |
243 | if (data[i++]) { | |
244 | ecryptfs_printk(KERN_ERR, "Status indicator has non-zero value " | |
245 | "[%d]\n", data[i-1]); | |
246 | rc = -EIO; | |
247 | goto out; | |
248 | } | |
f66e883e | 249 | rc = ecryptfs_parse_packet_length(&data[i], &m_size, &data_len); |
dddfa461 MH |
250 | if (rc) { |
251 | ecryptfs_printk(KERN_WARNING, "Error parsing packet length; " | |
252 | "rc = [%d]\n", rc); | |
253 | goto out; | |
254 | } | |
255 | i += data_len; | |
256 | if (message_len < (i + m_size)) { | |
624ae528 TH |
257 | ecryptfs_printk(KERN_ERR, "The message received from ecryptfsd " |
258 | "is shorter than expected\n"); | |
dddfa461 MH |
259 | rc = -EIO; |
260 | goto out; | |
261 | } | |
262 | if (m_size < 3) { | |
263 | ecryptfs_printk(KERN_ERR, | |
264 | "The decrypted key is not long enough to " | |
265 | "include a cipher code and checksum\n"); | |
266 | rc = -EIO; | |
267 | goto out; | |
268 | } | |
269 | *cipher_code = data[i++]; | |
270 | /* The decrypted key includes 1 byte cipher code and 2 byte checksum */ | |
271 | session_key->decrypted_key_size = m_size - 3; | |
272 | if (session_key->decrypted_key_size > ECRYPTFS_MAX_KEY_BYTES) { | |
273 | ecryptfs_printk(KERN_ERR, "key_size [%d] larger than " | |
274 | "the maximum key size [%d]\n", | |
275 | session_key->decrypted_key_size, | |
276 | ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES); | |
277 | rc = -EIO; | |
278 | goto out; | |
279 | } | |
280 | memcpy(session_key->decrypted_key, &data[i], | |
281 | session_key->decrypted_key_size); | |
282 | i += session_key->decrypted_key_size; | |
283 | expected_checksum += (unsigned char)(data[i++]) << 8; | |
284 | expected_checksum += (unsigned char)(data[i++]); | |
285 | for (i = 0; i < session_key->decrypted_key_size; i++) | |
286 | checksum += session_key->decrypted_key[i]; | |
287 | if (expected_checksum != checksum) { | |
288 | ecryptfs_printk(KERN_ERR, "Invalid checksum for file " | |
289 | "encryption key; expected [%x]; calculated " | |
290 | "[%x]\n", expected_checksum, checksum); | |
291 | rc = -EIO; | |
292 | } | |
293 | out: | |
294 | return rc; | |
295 | } | |
296 | ||
297 | ||
298 | static int | |
19e66a67 | 299 | write_tag_66_packet(char *signature, u8 cipher_code, |
dddfa461 MH |
300 | struct ecryptfs_crypt_stat *crypt_stat, char **packet, |
301 | size_t *packet_len) | |
302 | { | |
303 | size_t i = 0; | |
304 | size_t j; | |
305 | size_t data_len; | |
306 | size_t checksum = 0; | |
307 | size_t packet_size_len; | |
308 | char *message; | |
309 | int rc; | |
310 | ||
311 | /* | |
312 | * ***** TAG 66 Packet Format ***** | |
313 | * | Content Type | 1 byte | | |
314 | * | Key Identifier Size | 1 or 2 bytes | | |
315 | * | Key Identifier | arbitrary | | |
316 | * | File Encryption Key Size | 1 or 2 bytes | | |
317 | * | File Encryption Key | arbitrary | | |
318 | */ | |
319 | data_len = (5 + ECRYPTFS_SIG_SIZE_HEX + crypt_stat->key_size); | |
320 | *packet = kmalloc(data_len, GFP_KERNEL); | |
321 | message = *packet; | |
322 | if (!message) { | |
323 | ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n"); | |
324 | rc = -ENOMEM; | |
325 | goto out; | |
326 | } | |
327 | message[i++] = ECRYPTFS_TAG_66_PACKET_TYPE; | |
f66e883e MH |
328 | rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX, |
329 | &packet_size_len); | |
dddfa461 MH |
330 | if (rc) { |
331 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet " | |
332 | "header; cannot generate packet length\n"); | |
333 | goto out; | |
334 | } | |
335 | i += packet_size_len; | |
336 | memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX); | |
337 | i += ECRYPTFS_SIG_SIZE_HEX; | |
338 | /* The encrypted key includes 1 byte cipher code and 2 byte checksum */ | |
f66e883e MH |
339 | rc = ecryptfs_write_packet_length(&message[i], crypt_stat->key_size + 3, |
340 | &packet_size_len); | |
dddfa461 MH |
341 | if (rc) { |
342 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet " | |
343 | "header; cannot generate packet length\n"); | |
344 | goto out; | |
345 | } | |
346 | i += packet_size_len; | |
347 | message[i++] = cipher_code; | |
348 | memcpy(&message[i], crypt_stat->key, crypt_stat->key_size); | |
349 | i += crypt_stat->key_size; | |
350 | for (j = 0; j < crypt_stat->key_size; j++) | |
351 | checksum += crypt_stat->key[j]; | |
352 | message[i++] = (checksum / 256) % 256; | |
353 | message[i++] = (checksum % 256); | |
354 | *packet_len = i; | |
355 | out: | |
356 | return rc; | |
357 | } | |
358 | ||
359 | static int | |
360 | parse_tag_67_packet(struct ecryptfs_key_record *key_rec, | |
361 | struct ecryptfs_message *msg) | |
362 | { | |
363 | size_t i = 0; | |
364 | char *data; | |
365 | size_t data_len; | |
366 | size_t message_len; | |
367 | int rc; | |
368 | ||
369 | /* | |
370 | * ***** TAG 65 Packet Format ***** | |
371 | * | Content Type | 1 byte | | |
372 | * | Status Indicator | 1 byte | | |
373 | * | Encrypted File Encryption Key Size | 1 or 2 bytes | | |
374 | * | Encrypted File Encryption Key | arbitrary | | |
375 | */ | |
376 | message_len = msg->data_len; | |
377 | data = msg->data; | |
378 | /* verify that everything through the encrypted FEK size is present */ | |
379 | if (message_len < 4) { | |
380 | rc = -EIO; | |
df261c52 | 381 | printk(KERN_ERR "%s: message_len is [%zd]; minimum acceptable " |
f66e883e | 382 | "message length is [%d]\n", __func__, message_len, 4); |
dddfa461 MH |
383 | goto out; |
384 | } | |
385 | if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) { | |
dddfa461 | 386 | rc = -EIO; |
f66e883e MH |
387 | printk(KERN_ERR "%s: Type should be ECRYPTFS_TAG_67\n", |
388 | __func__); | |
dddfa461 MH |
389 | goto out; |
390 | } | |
391 | if (data[i++]) { | |
dddfa461 | 392 | rc = -EIO; |
f66e883e MH |
393 | printk(KERN_ERR "%s: Status indicator has non zero " |
394 | "value [%d]\n", __func__, data[i-1]); | |
395 | ||
dddfa461 MH |
396 | goto out; |
397 | } | |
f66e883e MH |
398 | rc = ecryptfs_parse_packet_length(&data[i], &key_rec->enc_key_size, |
399 | &data_len); | |
dddfa461 MH |
400 | if (rc) { |
401 | ecryptfs_printk(KERN_WARNING, "Error parsing packet length; " | |
402 | "rc = [%d]\n", rc); | |
403 | goto out; | |
404 | } | |
405 | i += data_len; | |
406 | if (message_len < (i + key_rec->enc_key_size)) { | |
dddfa461 | 407 | rc = -EIO; |
df261c52 | 408 | printk(KERN_ERR "%s: message_len [%zd]; max len is [%zd]\n", |
f66e883e | 409 | __func__, message_len, (i + key_rec->enc_key_size)); |
dddfa461 MH |
410 | goto out; |
411 | } | |
412 | if (key_rec->enc_key_size > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
dddfa461 | 413 | rc = -EIO; |
df261c52 | 414 | printk(KERN_ERR "%s: Encrypted key_size [%zd] larger than " |
f66e883e MH |
415 | "the maximum key size [%d]\n", __func__, |
416 | key_rec->enc_key_size, | |
417 | ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES); | |
dddfa461 MH |
418 | goto out; |
419 | } | |
420 | memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size); | |
421 | out: | |
422 | return rc; | |
423 | } | |
424 | ||
0e1fc5ef RS |
425 | /** |
426 | * ecryptfs_verify_version | |
427 | * @version: The version number to confirm | |
428 | * | |
429 | * Returns zero on good version; non-zero otherwise | |
430 | */ | |
431 | static int ecryptfs_verify_version(u16 version) | |
432 | { | |
433 | int rc = 0; | |
434 | unsigned char major; | |
435 | unsigned char minor; | |
436 | ||
437 | major = ((version >> 8) & 0xFF); | |
438 | minor = (version & 0xFF); | |
439 | if (major != ECRYPTFS_VERSION_MAJOR) { | |
440 | ecryptfs_printk(KERN_ERR, "Major version number mismatch. " | |
441 | "Expected [%d]; got [%d]\n", | |
442 | ECRYPTFS_VERSION_MAJOR, major); | |
443 | rc = -EINVAL; | |
444 | goto out; | |
445 | } | |
446 | if (minor != ECRYPTFS_VERSION_MINOR) { | |
447 | ecryptfs_printk(KERN_ERR, "Minor version number mismatch. " | |
448 | "Expected [%d]; got [%d]\n", | |
449 | ECRYPTFS_VERSION_MINOR, minor); | |
450 | rc = -EINVAL; | |
451 | goto out; | |
452 | } | |
453 | out: | |
454 | return rc; | |
455 | } | |
456 | ||
457 | /** | |
458 | * ecryptfs_verify_auth_tok_from_key | |
459 | * @auth_tok_key: key containing the authentication token | |
460 | * @auth_tok: authentication token | |
461 | * | |
462 | * Returns zero on valid auth tok; -EINVAL otherwise | |
463 | */ | |
464 | static int | |
465 | ecryptfs_verify_auth_tok_from_key(struct key *auth_tok_key, | |
466 | struct ecryptfs_auth_tok **auth_tok) | |
467 | { | |
468 | int rc = 0; | |
469 | ||
470 | (*auth_tok) = ecryptfs_get_key_payload_data(auth_tok_key); | |
471 | if (ecryptfs_verify_version((*auth_tok)->version)) { | |
472 | printk(KERN_ERR "Data structure version mismatch. Userspace " | |
473 | "tools must match eCryptfs kernel module with major " | |
474 | "version [%d] and minor version [%d]\n", | |
475 | ECRYPTFS_VERSION_MAJOR, ECRYPTFS_VERSION_MINOR); | |
476 | rc = -EINVAL; | |
477 | goto out; | |
478 | } | |
479 | if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD | |
480 | && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) { | |
481 | printk(KERN_ERR "Invalid auth_tok structure " | |
482 | "returned from key query\n"); | |
483 | rc = -EINVAL; | |
484 | goto out; | |
485 | } | |
486 | out: | |
487 | return rc; | |
488 | } | |
489 | ||
9c79f34f MH |
490 | static int |
491 | ecryptfs_find_global_auth_tok_for_sig( | |
0e1fc5ef RS |
492 | struct key **auth_tok_key, |
493 | struct ecryptfs_auth_tok **auth_tok, | |
9c79f34f MH |
494 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig) |
495 | { | |
496 | struct ecryptfs_global_auth_tok *walker; | |
497 | int rc = 0; | |
498 | ||
0e1fc5ef RS |
499 | (*auth_tok_key) = NULL; |
500 | (*auth_tok) = NULL; | |
9c79f34f MH |
501 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); |
502 | list_for_each_entry(walker, | |
503 | &mount_crypt_stat->global_auth_tok_list, | |
504 | mount_crypt_stat_list) { | |
0e1fc5ef RS |
505 | if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX)) |
506 | continue; | |
507 | ||
508 | if (walker->flags & ECRYPTFS_AUTH_TOK_INVALID) { | |
509 | rc = -EINVAL; | |
9c79f34f MH |
510 | goto out; |
511 | } | |
0e1fc5ef RS |
512 | |
513 | rc = key_validate(walker->global_auth_tok_key); | |
514 | if (rc) { | |
515 | if (rc == -EKEYEXPIRED) | |
516 | goto out; | |
517 | goto out_invalid_auth_tok; | |
518 | } | |
519 | ||
b5695d04 | 520 | down_write(&(walker->global_auth_tok_key->sem)); |
0e1fc5ef RS |
521 | rc = ecryptfs_verify_auth_tok_from_key( |
522 | walker->global_auth_tok_key, auth_tok); | |
523 | if (rc) | |
b5695d04 | 524 | goto out_invalid_auth_tok_unlock; |
0e1fc5ef RS |
525 | |
526 | (*auth_tok_key) = walker->global_auth_tok_key; | |
527 | key_get(*auth_tok_key); | |
528 | goto out; | |
9c79f34f | 529 | } |
0e1fc5ef RS |
530 | rc = -ENOENT; |
531 | goto out; | |
b5695d04 RS |
532 | out_invalid_auth_tok_unlock: |
533 | up_write(&(walker->global_auth_tok_key->sem)); | |
0e1fc5ef RS |
534 | out_invalid_auth_tok: |
535 | printk(KERN_WARNING "Invalidating auth tok with sig = [%s]\n", sig); | |
536 | walker->flags |= ECRYPTFS_AUTH_TOK_INVALID; | |
537 | key_put(walker->global_auth_tok_key); | |
538 | walker->global_auth_tok_key = NULL; | |
9c79f34f MH |
539 | out: |
540 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
541 | return rc; | |
542 | } | |
543 | ||
544 | /** | |
545 | * ecryptfs_find_auth_tok_for_sig | |
546 | * @auth_tok: Set to the matching auth_tok; NULL if not found | |
547 | * @crypt_stat: inode crypt_stat crypto context | |
548 | * @sig: Sig of auth_tok to find | |
549 | * | |
550 | * For now, this function simply looks at the registered auth_tok's | |
551 | * linked off the mount_crypt_stat, so all the auth_toks that can be | |
552 | * used must be registered at mount time. This function could | |
553 | * potentially try a lot harder to find auth_tok's (e.g., by calling | |
554 | * out to ecryptfsd to dynamically retrieve an auth_tok object) so | |
555 | * that static registration of auth_tok's will no longer be necessary. | |
556 | * | |
557 | * Returns zero on no error; non-zero on error | |
558 | */ | |
559 | static int | |
560 | ecryptfs_find_auth_tok_for_sig( | |
aee683b9 | 561 | struct key **auth_tok_key, |
9c79f34f MH |
562 | struct ecryptfs_auth_tok **auth_tok, |
563 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
564 | char *sig) | |
565 | { | |
9c79f34f MH |
566 | int rc = 0; |
567 | ||
0e1fc5ef RS |
568 | rc = ecryptfs_find_global_auth_tok_for_sig(auth_tok_key, auth_tok, |
569 | mount_crypt_stat, sig); | |
570 | if (rc == -ENOENT) { | |
f16feb51 RS |
571 | /* if the flag ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY is set in the |
572 | * mount_crypt_stat structure, we prevent to use auth toks that | |
573 | * are not inserted through the ecryptfs_add_global_auth_tok | |
574 | * function. | |
575 | */ | |
576 | if (mount_crypt_stat->flags | |
577 | & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY) | |
578 | return -EINVAL; | |
579 | ||
aee683b9 | 580 | rc = ecryptfs_keyring_auth_tok_for_sig(auth_tok_key, auth_tok, |
9c79f34f | 581 | sig); |
0e1fc5ef | 582 | } |
9c79f34f MH |
583 | return rc; |
584 | } | |
585 | ||
586 | /** | |
587 | * write_tag_70_packet can gobble a lot of stack space. We stuff most | |
588 | * of the function's parameters in a kmalloc'd struct to help reduce | |
589 | * eCryptfs' overall stack usage. | |
590 | */ | |
591 | struct ecryptfs_write_tag_70_packet_silly_stack { | |
592 | u8 cipher_code; | |
593 | size_t max_packet_size; | |
594 | size_t packet_size_len; | |
595 | size_t block_aligned_filename_size; | |
596 | size_t block_size; | |
597 | size_t i; | |
598 | size_t j; | |
599 | size_t num_rand_bytes; | |
600 | struct mutex *tfm_mutex; | |
601 | char *block_aligned_filename; | |
602 | struct ecryptfs_auth_tok *auth_tok; | |
8d08dab7 TH |
603 | struct scatterlist src_sg[2]; |
604 | struct scatterlist dst_sg[2]; | |
3095e8e3 HX |
605 | struct crypto_skcipher *skcipher_tfm; |
606 | struct skcipher_request *skcipher_req; | |
9c79f34f MH |
607 | char iv[ECRYPTFS_MAX_IV_BYTES]; |
608 | char hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; | |
609 | char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; | |
3095e8e3 HX |
610 | struct crypto_shash *hash_tfm; |
611 | struct shash_desc *hash_desc; | |
9c79f34f MH |
612 | }; |
613 | ||
614 | /** | |
615 | * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK | |
616 | * @filename: NULL-terminated filename string | |
617 | * | |
618 | * This is the simplest mechanism for achieving filename encryption in | |
619 | * eCryptfs. It encrypts the given filename with the mount-wide | |
620 | * filename encryption key (FNEK) and stores it in a packet to @dest, | |
621 | * which the callee will encode and write directly into the dentry | |
622 | * name. | |
623 | */ | |
624 | int | |
625 | ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, | |
626 | size_t *packet_size, | |
627 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
628 | char *filename, size_t filename_size) | |
629 | { | |
630 | struct ecryptfs_write_tag_70_packet_silly_stack *s; | |
aee683b9 | 631 | struct key *auth_tok_key = NULL; |
9c79f34f MH |
632 | int rc = 0; |
633 | ||
3095e8e3 | 634 | s = kzalloc(sizeof(*s), GFP_KERNEL); |
9c79f34f MH |
635 | if (!s) { |
636 | printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc " | |
df261c52 | 637 | "[%zd] bytes of kernel memory\n", __func__, sizeof(*s)); |
d1558f4e | 638 | return -ENOMEM; |
9c79f34f | 639 | } |
9c79f34f | 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 | 651 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name( |
3095e8e3 | 652 | &s->skcipher_tfm, |
9c79f34f MH |
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); | |
3095e8e3 | 661 | s->block_size = crypto_skcipher_blocksize(s->skcipher_tfm); |
9c79f34f MH |
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 | } | |
3095e8e3 HX |
694 | |
695 | s->skcipher_req = skcipher_request_alloc(s->skcipher_tfm, GFP_KERNEL); | |
696 | if (!s->skcipher_req) { | |
697 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " | |
698 | "skcipher_request_alloc for %s\n", __func__, | |
699 | crypto_skcipher_driver_name(s->skcipher_tfm)); | |
700 | rc = -ENOMEM; | |
701 | goto out_unlock; | |
702 | } | |
703 | ||
704 | skcipher_request_set_callback(s->skcipher_req, | |
705 | CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL); | |
706 | ||
9c79f34f MH |
707 | s->block_aligned_filename = kzalloc(s->block_aligned_filename_size, |
708 | GFP_KERNEL); | |
709 | if (!s->block_aligned_filename) { | |
710 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " | |
df261c52 | 711 | "kzalloc [%zd] bytes\n", __func__, |
9c79f34f MH |
712 | s->block_aligned_filename_size); |
713 | rc = -ENOMEM; | |
714 | goto out_unlock; | |
715 | } | |
9c79f34f MH |
716 | dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE; |
717 | rc = ecryptfs_write_packet_length(&dest[s->i], | |
718 | (ECRYPTFS_SIG_SIZE | |
719 | + 1 /* Cipher code */ | |
720 | + s->block_aligned_filename_size), | |
721 | &s->packet_size_len); | |
722 | if (rc) { | |
723 | printk(KERN_ERR "%s: Error generating tag 70 packet " | |
724 | "header; cannot generate packet length; rc = [%d]\n", | |
725 | __func__, rc); | |
726 | goto out_free_unlock; | |
727 | } | |
728 | s->i += s->packet_size_len; | |
729 | ecryptfs_from_hex(&dest[s->i], | |
730 | mount_crypt_stat->global_default_fnek_sig, | |
731 | ECRYPTFS_SIG_SIZE); | |
732 | s->i += ECRYPTFS_SIG_SIZE; | |
733 | s->cipher_code = ecryptfs_code_for_cipher_string( | |
734 | mount_crypt_stat->global_default_fn_cipher_name, | |
735 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
736 | if (s->cipher_code == 0) { | |
737 | printk(KERN_WARNING "%s: Unable to generate code for " | |
a8f12864 | 738 | "cipher [%s] with key bytes [%zd]\n", __func__, |
9c79f34f MH |
739 | mount_crypt_stat->global_default_fn_cipher_name, |
740 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
741 | rc = -EINVAL; | |
742 | goto out_free_unlock; | |
743 | } | |
744 | dest[s->i++] = s->cipher_code; | |
9c79f34f MH |
745 | /* TODO: Support other key modules than passphrase for |
746 | * filename encryption */ | |
df6ad33b TH |
747 | if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) { |
748 | rc = -EOPNOTSUPP; | |
749 | printk(KERN_INFO "%s: Filename encryption only supports " | |
750 | "password tokens\n", __func__); | |
751 | goto out_free_unlock; | |
752 | } | |
3095e8e3 HX |
753 | s->hash_tfm = crypto_alloc_shash(ECRYPTFS_TAG_70_DIGEST, 0, 0); |
754 | if (IS_ERR(s->hash_tfm)) { | |
755 | rc = PTR_ERR(s->hash_tfm); | |
9c79f34f MH |
756 | printk(KERN_ERR "%s: Error attempting to " |
757 | "allocate hash crypto context; rc = [%d]\n", | |
758 | __func__, rc); | |
759 | goto out_free_unlock; | |
760 | } | |
3095e8e3 HX |
761 | |
762 | s->hash_desc = kmalloc(sizeof(*s->hash_desc) + | |
763 | crypto_shash_descsize(s->hash_tfm), GFP_KERNEL); | |
764 | if (!s->hash_desc) { | |
765 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " | |
766 | "kmalloc [%zd] bytes\n", __func__, | |
767 | sizeof(*s->hash_desc) + | |
768 | crypto_shash_descsize(s->hash_tfm)); | |
769 | rc = -ENOMEM; | |
9c79f34f MH |
770 | goto out_release_free_unlock; |
771 | } | |
3095e8e3 HX |
772 | |
773 | s->hash_desc->tfm = s->hash_tfm; | |
774 | s->hash_desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; | |
775 | ||
776 | rc = crypto_shash_digest(s->hash_desc, | |
777 | (u8 *)s->auth_tok->token.password.session_key_encryption_key, | |
778 | s->auth_tok->token.password.session_key_encryption_key_bytes, | |
779 | s->hash); | |
9c79f34f MH |
780 | if (rc) { |
781 | printk(KERN_ERR | |
3095e8e3 | 782 | "%s: Error computing crypto hash; rc = [%d]\n", |
9c79f34f MH |
783 | __func__, rc); |
784 | goto out_release_free_unlock; | |
785 | } | |
786 | for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) { | |
787 | s->block_aligned_filename[s->j] = | |
788 | s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)]; | |
789 | if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE) | |
790 | == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) { | |
3095e8e3 HX |
791 | rc = crypto_shash_digest(s->hash_desc, (u8 *)s->hash, |
792 | ECRYPTFS_TAG_70_DIGEST_SIZE, | |
793 | s->tmp_hash); | |
9c79f34f MH |
794 | if (rc) { |
795 | printk(KERN_ERR | |
3095e8e3 | 796 | "%s: Error computing crypto hash; " |
9c79f34f MH |
797 | "rc = [%d]\n", __func__, rc); |
798 | goto out_release_free_unlock; | |
799 | } | |
800 | memcpy(s->hash, s->tmp_hash, | |
801 | ECRYPTFS_TAG_70_DIGEST_SIZE); | |
802 | } | |
803 | if (s->block_aligned_filename[s->j] == '\0') | |
804 | s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL; | |
805 | } | |
806 | memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename, | |
807 | filename_size); | |
808 | rc = virt_to_scatterlist(s->block_aligned_filename, | |
8d08dab7 TH |
809 | s->block_aligned_filename_size, s->src_sg, 2); |
810 | if (rc < 1) { | |
9c79f34f | 811 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
8d08dab7 | 812 | "convert filename memory to scatterlist; rc = [%d]. " |
a8f12864 | 813 | "block_aligned_filename_size = [%zd]\n", __func__, rc, |
9c79f34f MH |
814 | s->block_aligned_filename_size); |
815 | goto out_release_free_unlock; | |
816 | } | |
817 | rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size, | |
8d08dab7 TH |
818 | s->dst_sg, 2); |
819 | if (rc < 1) { | |
9c79f34f MH |
820 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
821 | "convert encrypted filename memory to scatterlist; " | |
8d08dab7 TH |
822 | "rc = [%d]. block_aligned_filename_size = [%zd]\n", |
823 | __func__, rc, s->block_aligned_filename_size); | |
9c79f34f MH |
824 | goto out_release_free_unlock; |
825 | } | |
826 | /* The characters in the first block effectively do the job | |
827 | * of the IV here, so we just use 0's for the IV. Note the | |
828 | * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES | |
829 | * >= ECRYPTFS_MAX_IV_BYTES. */ | |
3095e8e3 HX |
830 | rc = crypto_skcipher_setkey( |
831 | s->skcipher_tfm, | |
9c79f34f MH |
832 | s->auth_tok->token.password.session_key_encryption_key, |
833 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
834 | if (rc < 0) { | |
835 | printk(KERN_ERR "%s: Error setting key for crypto context; " | |
836 | "rc = [%d]. s->auth_tok->token.password.session_key_" | |
837 | "encryption_key = [0x%p]; mount_crypt_stat->" | |
df261c52 | 838 | "global_default_fn_cipher_key_bytes = [%zd]\n", __func__, |
9c79f34f MH |
839 | rc, |
840 | s->auth_tok->token.password.session_key_encryption_key, | |
841 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
842 | goto out_release_free_unlock; | |
843 | } | |
3095e8e3 HX |
844 | skcipher_request_set_crypt(s->skcipher_req, s->src_sg, s->dst_sg, |
845 | s->block_aligned_filename_size, s->iv); | |
846 | rc = crypto_skcipher_encrypt(s->skcipher_req); | |
9c79f34f MH |
847 | if (rc) { |
848 | printk(KERN_ERR "%s: Error attempting to encrypt filename; " | |
849 | "rc = [%d]\n", __func__, rc); | |
850 | goto out_release_free_unlock; | |
851 | } | |
852 | s->i += s->block_aligned_filename_size; | |
853 | (*packet_size) = s->i; | |
854 | (*remaining_bytes) -= (*packet_size); | |
855 | out_release_free_unlock: | |
3095e8e3 | 856 | crypto_free_shash(s->hash_tfm); |
9c79f34f | 857 | out_free_unlock: |
00fcf2cb | 858 | kzfree(s->block_aligned_filename); |
9c79f34f MH |
859 | out_unlock: |
860 | mutex_unlock(s->tfm_mutex); | |
861 | out: | |
b5695d04 RS |
862 | if (auth_tok_key) { |
863 | up_write(&(auth_tok_key->sem)); | |
aee683b9 | 864 | key_put(auth_tok_key); |
b5695d04 | 865 | } |
3095e8e3 HX |
866 | skcipher_request_free(s->skcipher_req); |
867 | kzfree(s->hash_desc); | |
9c79f34f MH |
868 | kfree(s); |
869 | return rc; | |
870 | } | |
871 | ||
872 | struct ecryptfs_parse_tag_70_packet_silly_stack { | |
873 | u8 cipher_code; | |
874 | size_t max_packet_size; | |
875 | size_t packet_size_len; | |
876 | size_t parsed_tag_70_packet_size; | |
877 | size_t block_aligned_filename_size; | |
878 | size_t block_size; | |
879 | size_t i; | |
880 | struct mutex *tfm_mutex; | |
881 | char *decrypted_filename; | |
882 | struct ecryptfs_auth_tok *auth_tok; | |
8d08dab7 TH |
883 | struct scatterlist src_sg[2]; |
884 | struct scatterlist dst_sg[2]; | |
3095e8e3 HX |
885 | struct crypto_skcipher *skcipher_tfm; |
886 | struct skcipher_request *skcipher_req; | |
9c79f34f MH |
887 | char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1]; |
888 | char iv[ECRYPTFS_MAX_IV_BYTES]; | |
2a559a8b | 889 | char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1]; |
9c79f34f MH |
890 | }; |
891 | ||
892 | /** | |
893 | * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet | |
894 | * @filename: This function kmalloc's the memory for the filename | |
7d8bc2be MH |
895 | * @filename_size: This function sets this to the amount of memory |
896 | * kmalloc'd for the filename | |
897 | * @packet_size: This function sets this to the the number of octets | |
898 | * in the packet parsed | |
899 | * @mount_crypt_stat: The mount-wide cryptographic context | |
900 | * @data: The memory location containing the start of the tag 70 | |
901 | * packet | |
902 | * @max_packet_size: The maximum legal size of the packet to be parsed | |
903 | * from @data | |
904 | * | |
905 | * Returns zero on success; non-zero otherwise | |
9c79f34f MH |
906 | */ |
907 | int | |
908 | ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, | |
909 | size_t *packet_size, | |
910 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
911 | char *data, size_t max_packet_size) | |
912 | { | |
913 | struct ecryptfs_parse_tag_70_packet_silly_stack *s; | |
aee683b9 | 914 | struct key *auth_tok_key = NULL; |
9c79f34f MH |
915 | int rc = 0; |
916 | ||
917 | (*packet_size) = 0; | |
918 | (*filename_size) = 0; | |
919 | (*filename) = NULL; | |
3095e8e3 | 920 | s = kzalloc(sizeof(*s), GFP_KERNEL); |
9c79f34f MH |
921 | if (!s) { |
922 | printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc " | |
a8f12864 | 923 | "[%zd] bytes of kernel memory\n", __func__, sizeof(*s)); |
d1558f4e | 924 | return -ENOMEM; |
9c79f34f | 925 | } |
4a26620d | 926 | if (max_packet_size < ECRYPTFS_TAG_70_MIN_METADATA_SIZE) { |
df261c52 | 927 | printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be " |
9c79f34f | 928 | "at least [%d]\n", __func__, max_packet_size, |
4a26620d | 929 | ECRYPTFS_TAG_70_MIN_METADATA_SIZE); |
9c79f34f MH |
930 | rc = -EINVAL; |
931 | goto out; | |
932 | } | |
933 | /* Octet 0: Tag 70 identifier | |
934 | * Octets 1-N1: Tag 70 packet size (includes cipher identifier | |
935 | * and block-aligned encrypted filename size) | |
936 | * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) | |
937 | * Octet N2-N3: Cipher identifier (1 octet) | |
938 | * Octets N3-N4: Block-aligned encrypted filename | |
939 | * - Consists of a minimum number of random numbers, a \0 | |
940 | * separator, and then the filename */ | |
941 | if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) { | |
942 | printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be " | |
943 | "tag [0x%.2x]\n", __func__, | |
944 | data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE); | |
945 | rc = -EINVAL; | |
946 | goto out; | |
947 | } | |
948 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], | |
949 | &s->parsed_tag_70_packet_size, | |
950 | &s->packet_size_len); | |
951 | if (rc) { | |
952 | printk(KERN_WARNING "%s: Error parsing packet length; " | |
953 | "rc = [%d]\n", __func__, rc); | |
954 | goto out; | |
955 | } | |
956 | s->block_aligned_filename_size = (s->parsed_tag_70_packet_size | |
957 | - ECRYPTFS_SIG_SIZE - 1); | |
958 | if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size) | |
959 | > max_packet_size) { | |
a8f12864 MH |
960 | printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet " |
961 | "size is [%zd]\n", __func__, max_packet_size, | |
9c79f34f MH |
962 | (1 + s->packet_size_len + 1 |
963 | + s->block_aligned_filename_size)); | |
964 | rc = -EINVAL; | |
965 | goto out; | |
966 | } | |
967 | (*packet_size) += s->packet_size_len; | |
968 | ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)], | |
969 | ECRYPTFS_SIG_SIZE); | |
970 | s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0'; | |
971 | (*packet_size) += ECRYPTFS_SIG_SIZE; | |
972 | s->cipher_code = data[(*packet_size)++]; | |
973 | rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code); | |
974 | if (rc) { | |
975 | printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n", | |
976 | __func__, s->cipher_code); | |
977 | goto out; | |
978 | } | |
950983fc RS |
979 | rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key, |
980 | &s->auth_tok, mount_crypt_stat, | |
981 | s->fnek_sig_hex); | |
982 | if (rc) { | |
983 | printk(KERN_ERR "%s: Error attempting to find auth tok for " | |
984 | "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex, | |
985 | rc); | |
986 | goto out; | |
987 | } | |
3095e8e3 | 988 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->skcipher_tfm, |
9c79f34f MH |
989 | &s->tfm_mutex, |
990 | s->cipher_string); | |
991 | if (unlikely(rc)) { | |
992 | printk(KERN_ERR "Internal error whilst attempting to get " | |
993 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
994 | s->cipher_string, rc); | |
995 | goto out; | |
996 | } | |
997 | mutex_lock(s->tfm_mutex); | |
998 | rc = virt_to_scatterlist(&data[(*packet_size)], | |
8d08dab7 TH |
999 | s->block_aligned_filename_size, s->src_sg, 2); |
1000 | if (rc < 1) { | |
9c79f34f MH |
1001 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
1002 | "convert encrypted filename memory to scatterlist; " | |
8d08dab7 TH |
1003 | "rc = [%d]. block_aligned_filename_size = [%zd]\n", |
1004 | __func__, rc, s->block_aligned_filename_size); | |
9c79f34f MH |
1005 | goto out_unlock; |
1006 | } | |
1007 | (*packet_size) += s->block_aligned_filename_size; | |
1008 | s->decrypted_filename = kmalloc(s->block_aligned_filename_size, | |
1009 | GFP_KERNEL); | |
1010 | if (!s->decrypted_filename) { | |
1011 | printk(KERN_ERR "%s: Out of memory whilst attempting to " | |
a8f12864 | 1012 | "kmalloc [%zd] bytes\n", __func__, |
9c79f34f MH |
1013 | s->block_aligned_filename_size); |
1014 | rc = -ENOMEM; | |
1015 | goto out_unlock; | |
1016 | } | |
1017 | rc = virt_to_scatterlist(s->decrypted_filename, | |
8d08dab7 TH |
1018 | s->block_aligned_filename_size, s->dst_sg, 2); |
1019 | if (rc < 1) { | |
9c79f34f MH |
1020 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
1021 | "convert decrypted filename memory to scatterlist; " | |
8d08dab7 TH |
1022 | "rc = [%d]. block_aligned_filename_size = [%zd]\n", |
1023 | __func__, rc, s->block_aligned_filename_size); | |
9c79f34f MH |
1024 | goto out_free_unlock; |
1025 | } | |
3095e8e3 HX |
1026 | |
1027 | s->skcipher_req = skcipher_request_alloc(s->skcipher_tfm, GFP_KERNEL); | |
1028 | if (!s->skcipher_req) { | |
1029 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " | |
1030 | "skcipher_request_alloc for %s\n", __func__, | |
1031 | crypto_skcipher_driver_name(s->skcipher_tfm)); | |
1032 | rc = -ENOMEM; | |
1033 | goto out_free_unlock; | |
1034 | } | |
1035 | ||
1036 | skcipher_request_set_callback(s->skcipher_req, | |
1037 | CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL); | |
1038 | ||
9c79f34f MH |
1039 | /* The characters in the first block effectively do the job of |
1040 | * the IV here, so we just use 0's for the IV. Note the | |
1041 | * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES | |
1042 | * >= ECRYPTFS_MAX_IV_BYTES. */ | |
9c79f34f MH |
1043 | /* TODO: Support other key modules than passphrase for |
1044 | * filename encryption */ | |
df6ad33b TH |
1045 | if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) { |
1046 | rc = -EOPNOTSUPP; | |
1047 | printk(KERN_INFO "%s: Filename encryption only supports " | |
1048 | "password tokens\n", __func__); | |
1049 | goto out_free_unlock; | |
1050 | } | |
3095e8e3 HX |
1051 | rc = crypto_skcipher_setkey( |
1052 | s->skcipher_tfm, | |
9c79f34f MH |
1053 | s->auth_tok->token.password.session_key_encryption_key, |
1054 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
1055 | if (rc < 0) { | |
1056 | printk(KERN_ERR "%s: Error setting key for crypto context; " | |
1057 | "rc = [%d]. s->auth_tok->token.password.session_key_" | |
1058 | "encryption_key = [0x%p]; mount_crypt_stat->" | |
df261c52 | 1059 | "global_default_fn_cipher_key_bytes = [%zd]\n", __func__, |
9c79f34f MH |
1060 | rc, |
1061 | s->auth_tok->token.password.session_key_encryption_key, | |
1062 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
1063 | goto out_free_unlock; | |
1064 | } | |
3095e8e3 HX |
1065 | skcipher_request_set_crypt(s->skcipher_req, s->src_sg, s->dst_sg, |
1066 | s->block_aligned_filename_size, s->iv); | |
1067 | rc = crypto_skcipher_decrypt(s->skcipher_req); | |
9c79f34f MH |
1068 | if (rc) { |
1069 | printk(KERN_ERR "%s: Error attempting to decrypt filename; " | |
1070 | "rc = [%d]\n", __func__, rc); | |
1071 | goto out_free_unlock; | |
1072 | } | |
9c79f34f MH |
1073 | while (s->decrypted_filename[s->i] != '\0' |
1074 | && s->i < s->block_aligned_filename_size) | |
1075 | s->i++; | |
1076 | if (s->i == s->block_aligned_filename_size) { | |
1077 | printk(KERN_WARNING "%s: Invalid tag 70 packet; could not " | |
1078 | "find valid separator between random characters and " | |
1079 | "the filename\n", __func__); | |
1080 | rc = -EINVAL; | |
1081 | goto out_free_unlock; | |
1082 | } | |
1083 | s->i++; | |
1084 | (*filename_size) = (s->block_aligned_filename_size - s->i); | |
1085 | if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) { | |
df261c52 | 1086 | printk(KERN_WARNING "%s: Filename size is [%zd], which is " |
9c79f34f MH |
1087 | "invalid\n", __func__, (*filename_size)); |
1088 | rc = -EINVAL; | |
1089 | goto out_free_unlock; | |
1090 | } | |
1091 | (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL); | |
1092 | if (!(*filename)) { | |
1093 | printk(KERN_ERR "%s: Out of memory whilst attempting to " | |
a8f12864 | 1094 | "kmalloc [%zd] bytes\n", __func__, |
9c79f34f MH |
1095 | ((*filename_size) + 1)); |
1096 | rc = -ENOMEM; | |
1097 | goto out_free_unlock; | |
1098 | } | |
1099 | memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size)); | |
1100 | (*filename)[(*filename_size)] = '\0'; | |
1101 | out_free_unlock: | |
1102 | kfree(s->decrypted_filename); | |
1103 | out_unlock: | |
1104 | mutex_unlock(s->tfm_mutex); | |
1105 | out: | |
1106 | if (rc) { | |
1107 | (*packet_size) = 0; | |
1108 | (*filename_size) = 0; | |
1109 | (*filename) = NULL; | |
1110 | } | |
b5695d04 RS |
1111 | if (auth_tok_key) { |
1112 | up_write(&(auth_tok_key->sem)); | |
aee683b9 | 1113 | key_put(auth_tok_key); |
b5695d04 | 1114 | } |
3095e8e3 | 1115 | skcipher_request_free(s->skcipher_req); |
9c79f34f MH |
1116 | kfree(s); |
1117 | return rc; | |
1118 | } | |
1119 | ||
cd9d67df MH |
1120 | static int |
1121 | ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok) | |
1122 | { | |
1123 | int rc = 0; | |
1124 | ||
1125 | (*sig) = NULL; | |
1126 | switch (auth_tok->token_type) { | |
1127 | case ECRYPTFS_PASSWORD: | |
1128 | (*sig) = auth_tok->token.password.signature; | |
1129 | break; | |
1130 | case ECRYPTFS_PRIVATE_KEY: | |
1131 | (*sig) = auth_tok->token.private_key.signature; | |
1132 | break; | |
1133 | default: | |
1134 | printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n", | |
1135 | auth_tok->token_type); | |
1136 | rc = -EINVAL; | |
1137 | } | |
1138 | return rc; | |
1139 | } | |
1140 | ||
dddfa461 | 1141 | /** |
22e78faf MH |
1142 | * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok. |
1143 | * @auth_tok: The key authentication token used to decrypt the session key | |
1144 | * @crypt_stat: The cryptographic context | |
dddfa461 | 1145 | * |
22e78faf | 1146 | * Returns zero on success; non-zero error otherwise. |
dddfa461 | 1147 | */ |
f4aad16a MH |
1148 | static int |
1149 | decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, | |
1150 | struct ecryptfs_crypt_stat *crypt_stat) | |
dddfa461 | 1151 | { |
19e66a67 | 1152 | u8 cipher_code = 0; |
dddfa461 MH |
1153 | struct ecryptfs_msg_ctx *msg_ctx; |
1154 | struct ecryptfs_message *msg = NULL; | |
f4aad16a | 1155 | char *auth_tok_sig; |
3edc8376 | 1156 | char *payload = NULL; |
fa519964 | 1157 | size_t payload_len = 0; |
dddfa461 MH |
1158 | int rc; |
1159 | ||
5dda6992 MH |
1160 | rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok); |
1161 | if (rc) { | |
f4aad16a MH |
1162 | printk(KERN_ERR "Unrecognized auth tok type: [%d]\n", |
1163 | auth_tok->token_type); | |
1164 | goto out; | |
1165 | } | |
1166 | rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key), | |
624ae528 | 1167 | &payload, &payload_len); |
dddfa461 | 1168 | if (rc) { |
f66e883e | 1169 | ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n"); |
dddfa461 MH |
1170 | goto out; |
1171 | } | |
624ae528 | 1172 | rc = ecryptfs_send_message(payload, payload_len, &msg_ctx); |
dddfa461 | 1173 | if (rc) { |
624ae528 | 1174 | ecryptfs_printk(KERN_ERR, "Error sending message to " |
290502be | 1175 | "ecryptfsd: %d\n", rc); |
dddfa461 MH |
1176 | goto out; |
1177 | } | |
1178 | rc = ecryptfs_wait_for_response(msg_ctx, &msg); | |
1179 | if (rc) { | |
1180 | ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet " | |
1181 | "from the user space daemon\n"); | |
1182 | rc = -EIO; | |
1183 | goto out; | |
1184 | } | |
1185 | rc = parse_tag_65_packet(&(auth_tok->session_key), | |
1186 | &cipher_code, msg); | |
1187 | if (rc) { | |
1188 | printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n", | |
1189 | rc); | |
1190 | goto out; | |
1191 | } | |
1192 | auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1193 | memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, | |
1194 | auth_tok->session_key.decrypted_key_size); | |
1195 | crypt_stat->key_size = auth_tok->session_key.decrypted_key_size; | |
1196 | rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code); | |
1197 | if (rc) { | |
1198 | ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n", | |
1199 | cipher_code) | |
1200 | goto out; | |
1201 | } | |
1202 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; | |
1203 | if (ecryptfs_verbosity > 0) { | |
1204 | ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n"); | |
1205 | ecryptfs_dump_hex(crypt_stat->key, | |
1206 | crypt_stat->key_size); | |
1207 | } | |
1208 | out: | |
3a467418 | 1209 | kfree(msg); |
3edc8376 | 1210 | kfree(payload); |
dddfa461 MH |
1211 | return rc; |
1212 | } | |
1213 | ||
1214 | static void wipe_auth_tok_list(struct list_head *auth_tok_list_head) | |
1215 | { | |
dddfa461 | 1216 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
e0869cc1 | 1217 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
dddfa461 | 1218 | |
e0869cc1 MH |
1219 | list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp, |
1220 | auth_tok_list_head, list) { | |
1221 | list_del(&auth_tok_list_item->list); | |
dddfa461 MH |
1222 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, |
1223 | auth_tok_list_item); | |
1224 | } | |
dddfa461 MH |
1225 | } |
1226 | ||
1227 | struct kmem_cache *ecryptfs_auth_tok_list_item_cache; | |
1228 | ||
dddfa461 MH |
1229 | /** |
1230 | * parse_tag_1_packet | |
22e78faf | 1231 | * @crypt_stat: The cryptographic context to modify based on packet contents |
dddfa461 MH |
1232 | * @data: The raw bytes of the packet. |
1233 | * @auth_tok_list: eCryptfs parses packets into authentication tokens; | |
22e78faf MH |
1234 | * a new authentication token will be placed at the |
1235 | * end of this list for this packet. | |
dddfa461 MH |
1236 | * @new_auth_tok: Pointer to a pointer to memory that this function |
1237 | * allocates; sets the memory address of the pointer to | |
1238 | * NULL on error. This object is added to the | |
1239 | * auth_tok_list. | |
1240 | * @packet_size: This function writes the size of the parsed packet | |
1241 | * into this memory location; zero on error. | |
22e78faf | 1242 | * @max_packet_size: The maximum allowable packet size |
dddfa461 MH |
1243 | * |
1244 | * Returns zero on success; non-zero on error. | |
1245 | */ | |
1246 | static int | |
1247 | parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat, | |
1248 | unsigned char *data, struct list_head *auth_tok_list, | |
1249 | struct ecryptfs_auth_tok **new_auth_tok, | |
1250 | size_t *packet_size, size_t max_packet_size) | |
1251 | { | |
1252 | size_t body_size; | |
1253 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; | |
1254 | size_t length_size; | |
1255 | int rc = 0; | |
1256 | ||
1257 | (*packet_size) = 0; | |
1258 | (*new_auth_tok) = NULL; | |
13218179 MH |
1259 | /** |
1260 | * This format is inspired by OpenPGP; see RFC 2440 | |
1261 | * packet tag 1 | |
1262 | * | |
1263 | * Tag 1 identifier (1 byte) | |
1264 | * Max Tag 1 packet size (max 3 bytes) | |
1265 | * Version (1 byte) | |
1266 | * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE) | |
1267 | * Cipher identifier (1 byte) | |
1268 | * Encrypted key size (arbitrary) | |
1269 | * | |
1270 | * 12 bytes minimum packet size | |
dddfa461 | 1271 | */ |
13218179 MH |
1272 | if (unlikely(max_packet_size < 12)) { |
1273 | printk(KERN_ERR "Invalid max packet size; must be >=12\n"); | |
dddfa461 MH |
1274 | rc = -EINVAL; |
1275 | goto out; | |
1276 | } | |
dddfa461 | 1277 | if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) { |
13218179 MH |
1278 | printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n", |
1279 | ECRYPTFS_TAG_1_PACKET_TYPE); | |
dddfa461 MH |
1280 | rc = -EINVAL; |
1281 | goto out; | |
1282 | } | |
1283 | /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or | |
1284 | * at end of function upon failure */ | |
1285 | auth_tok_list_item = | |
13218179 MH |
1286 | kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, |
1287 | GFP_KERNEL); | |
dddfa461 | 1288 | if (!auth_tok_list_item) { |
13218179 | 1289 | printk(KERN_ERR "Unable to allocate memory\n"); |
dddfa461 MH |
1290 | rc = -ENOMEM; |
1291 | goto out; | |
1292 | } | |
dddfa461 | 1293 | (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
f66e883e MH |
1294 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1295 | &length_size); | |
5dda6992 | 1296 | if (rc) { |
13218179 MH |
1297 | printk(KERN_WARNING "Error parsing packet length; " |
1298 | "rc = [%d]\n", rc); | |
dddfa461 MH |
1299 | goto out_free; |
1300 | } | |
13218179 | 1301 | if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) { |
81acbcd6 | 1302 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
dddfa461 MH |
1303 | rc = -EINVAL; |
1304 | goto out_free; | |
1305 | } | |
1306 | (*packet_size) += length_size; | |
1307 | if (unlikely((*packet_size) + body_size > max_packet_size)) { | |
13218179 | 1308 | printk(KERN_WARNING "Packet size exceeds max\n"); |
dddfa461 MH |
1309 | rc = -EINVAL; |
1310 | goto out_free; | |
1311 | } | |
dddfa461 | 1312 | if (unlikely(data[(*packet_size)++] != 0x03)) { |
13218179 MH |
1313 | printk(KERN_WARNING "Unknown version number [%d]\n", |
1314 | data[(*packet_size) - 1]); | |
dddfa461 MH |
1315 | rc = -EINVAL; |
1316 | goto out_free; | |
1317 | } | |
dddfa461 MH |
1318 | ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature, |
1319 | &data[(*packet_size)], ECRYPTFS_SIG_SIZE); | |
1320 | *packet_size += ECRYPTFS_SIG_SIZE; | |
1321 | /* This byte is skipped because the kernel does not need to | |
1322 | * know which public key encryption algorithm was used */ | |
1323 | (*packet_size)++; | |
1324 | (*new_auth_tok)->session_key.encrypted_key_size = | |
13218179 | 1325 | body_size - (ECRYPTFS_SIG_SIZE + 2); |
dddfa461 MH |
1326 | if ((*new_auth_tok)->session_key.encrypted_key_size |
1327 | > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
13218179 MH |
1328 | printk(KERN_WARNING "Tag 1 packet contains key larger " |
1329 | "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES"); | |
dddfa461 MH |
1330 | rc = -EINVAL; |
1331 | goto out; | |
1332 | } | |
dddfa461 | 1333 | memcpy((*new_auth_tok)->session_key.encrypted_key, |
13218179 | 1334 | &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2))); |
dddfa461 MH |
1335 | (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size; |
1336 | (*new_auth_tok)->session_key.flags &= | |
1337 | ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1338 | (*new_auth_tok)->session_key.flags |= | |
1339 | ECRYPTFS_CONTAINS_ENCRYPTED_KEY; | |
1340 | (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY; | |
13218179 | 1341 | (*new_auth_tok)->flags = 0; |
e2bd99ec MH |
1342 | (*new_auth_tok)->session_key.flags &= |
1343 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT); | |
1344 | (*new_auth_tok)->session_key.flags &= | |
1345 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT); | |
dddfa461 MH |
1346 | list_add(&auth_tok_list_item->list, auth_tok_list); |
1347 | goto out; | |
1348 | out_free: | |
1349 | (*new_auth_tok) = NULL; | |
1350 | memset(auth_tok_list_item, 0, | |
1351 | sizeof(struct ecryptfs_auth_tok_list_item)); | |
1352 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, | |
1353 | auth_tok_list_item); | |
1354 | out: | |
1355 | if (rc) | |
1356 | (*packet_size) = 0; | |
1357 | return rc; | |
1358 | } | |
1359 | ||
237fead6 MH |
1360 | /** |
1361 | * parse_tag_3_packet | |
1362 | * @crypt_stat: The cryptographic context to modify based on packet | |
1363 | * contents. | |
1364 | * @data: The raw bytes of the packet. | |
1365 | * @auth_tok_list: eCryptfs parses packets into authentication tokens; | |
1366 | * a new authentication token will be placed at the end | |
1367 | * of this list for this packet. | |
1368 | * @new_auth_tok: Pointer to a pointer to memory that this function | |
1369 | * allocates; sets the memory address of the pointer to | |
1370 | * NULL on error. This object is added to the | |
1371 | * auth_tok_list. | |
1372 | * @packet_size: This function writes the size of the parsed packet | |
1373 | * into this memory location; zero on error. | |
1374 | * @max_packet_size: maximum number of bytes to parse | |
1375 | * | |
1376 | * Returns zero on success; non-zero on error. | |
1377 | */ | |
1378 | static int | |
1379 | parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat, | |
1380 | unsigned char *data, struct list_head *auth_tok_list, | |
1381 | struct ecryptfs_auth_tok **new_auth_tok, | |
1382 | size_t *packet_size, size_t max_packet_size) | |
1383 | { | |
237fead6 MH |
1384 | size_t body_size; |
1385 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; | |
1386 | size_t length_size; | |
dddfa461 | 1387 | int rc = 0; |
237fead6 MH |
1388 | |
1389 | (*packet_size) = 0; | |
1390 | (*new_auth_tok) = NULL; | |
c59becfc MH |
1391 | /** |
1392 | *This format is inspired by OpenPGP; see RFC 2440 | |
1393 | * packet tag 3 | |
1394 | * | |
1395 | * Tag 3 identifier (1 byte) | |
1396 | * Max Tag 3 packet size (max 3 bytes) | |
1397 | * Version (1 byte) | |
1398 | * Cipher code (1 byte) | |
1399 | * S2K specifier (1 byte) | |
1400 | * Hash identifier (1 byte) | |
1401 | * Salt (ECRYPTFS_SALT_SIZE) | |
1402 | * Hash iterations (1 byte) | |
1403 | * Encrypted key (arbitrary) | |
1404 | * | |
1405 | * (ECRYPTFS_SALT_SIZE + 7) minimum packet size | |
237fead6 | 1406 | */ |
c59becfc MH |
1407 | if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) { |
1408 | printk(KERN_ERR "Max packet size too large\n"); | |
237fead6 MH |
1409 | rc = -EINVAL; |
1410 | goto out; | |
1411 | } | |
237fead6 | 1412 | if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) { |
c59becfc MH |
1413 | printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n", |
1414 | ECRYPTFS_TAG_3_PACKET_TYPE); | |
237fead6 MH |
1415 | rc = -EINVAL; |
1416 | goto out; | |
1417 | } | |
1418 | /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or | |
1419 | * at end of function upon failure */ | |
1420 | auth_tok_list_item = | |
c3762229 | 1421 | kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL); |
237fead6 | 1422 | if (!auth_tok_list_item) { |
c59becfc | 1423 | printk(KERN_ERR "Unable to allocate memory\n"); |
237fead6 MH |
1424 | rc = -ENOMEM; |
1425 | goto out; | |
1426 | } | |
237fead6 | 1427 | (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
f66e883e MH |
1428 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1429 | &length_size); | |
5dda6992 | 1430 | if (rc) { |
c59becfc MH |
1431 | printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n", |
1432 | rc); | |
237fead6 MH |
1433 | goto out_free; |
1434 | } | |
c59becfc | 1435 | if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) { |
81acbcd6 | 1436 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
237fead6 MH |
1437 | rc = -EINVAL; |
1438 | goto out_free; | |
1439 | } | |
1440 | (*packet_size) += length_size; | |
237fead6 | 1441 | if (unlikely((*packet_size) + body_size > max_packet_size)) { |
c59becfc | 1442 | printk(KERN_ERR "Packet size exceeds max\n"); |
237fead6 MH |
1443 | rc = -EINVAL; |
1444 | goto out_free; | |
1445 | } | |
237fead6 | 1446 | (*new_auth_tok)->session_key.encrypted_key_size = |
c59becfc | 1447 | (body_size - (ECRYPTFS_SALT_SIZE + 5)); |
f151cd2c RCV |
1448 | if ((*new_auth_tok)->session_key.encrypted_key_size |
1449 | > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
1450 | printk(KERN_WARNING "Tag 3 packet contains key larger " | |
1451 | "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n"); | |
1452 | rc = -EINVAL; | |
1453 | goto out_free; | |
1454 | } | |
237fead6 | 1455 | if (unlikely(data[(*packet_size)++] != 0x04)) { |
c59becfc MH |
1456 | printk(KERN_WARNING "Unknown version number [%d]\n", |
1457 | data[(*packet_size) - 1]); | |
237fead6 MH |
1458 | rc = -EINVAL; |
1459 | goto out_free; | |
1460 | } | |
b0105eae TH |
1461 | rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, |
1462 | (u16)data[(*packet_size)]); | |
1463 | if (rc) | |
1464 | goto out_free; | |
237fead6 MH |
1465 | /* A little extra work to differentiate among the AES key |
1466 | * sizes; see RFC2440 */ | |
1467 | switch(data[(*packet_size)++]) { | |
1468 | case RFC2440_CIPHER_AES_192: | |
1469 | crypt_stat->key_size = 24; | |
1470 | break; | |
1471 | default: | |
1472 | crypt_stat->key_size = | |
1473 | (*new_auth_tok)->session_key.encrypted_key_size; | |
1474 | } | |
b0105eae TH |
1475 | rc = ecryptfs_init_crypt_ctx(crypt_stat); |
1476 | if (rc) | |
1477 | goto out_free; | |
237fead6 | 1478 | if (unlikely(data[(*packet_size)++] != 0x03)) { |
c59becfc | 1479 | printk(KERN_WARNING "Only S2K ID 3 is currently supported\n"); |
237fead6 MH |
1480 | rc = -ENOSYS; |
1481 | goto out_free; | |
1482 | } | |
237fead6 | 1483 | /* TODO: finish the hash mapping */ |
237fead6 MH |
1484 | switch (data[(*packet_size)++]) { |
1485 | case 0x01: /* See RFC2440 for these numbers and their mappings */ | |
1486 | /* Choose MD5 */ | |
237fead6 MH |
1487 | memcpy((*new_auth_tok)->token.password.salt, |
1488 | &data[(*packet_size)], ECRYPTFS_SALT_SIZE); | |
1489 | (*packet_size) += ECRYPTFS_SALT_SIZE; | |
237fead6 | 1490 | /* This conversion was taken straight from RFC2440 */ |
237fead6 MH |
1491 | (*new_auth_tok)->token.password.hash_iterations = |
1492 | ((u32) 16 + (data[(*packet_size)] & 15)) | |
1493 | << ((data[(*packet_size)] >> 4) + 6); | |
1494 | (*packet_size)++; | |
c59becfc MH |
1495 | /* Friendly reminder: |
1496 | * (*new_auth_tok)->session_key.encrypted_key_size = | |
1497 | * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */ | |
237fead6 MH |
1498 | memcpy((*new_auth_tok)->session_key.encrypted_key, |
1499 | &data[(*packet_size)], | |
1500 | (*new_auth_tok)->session_key.encrypted_key_size); | |
1501 | (*packet_size) += | |
1502 | (*new_auth_tok)->session_key.encrypted_key_size; | |
1503 | (*new_auth_tok)->session_key.flags &= | |
1504 | ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1505 | (*new_auth_tok)->session_key.flags |= | |
1506 | ECRYPTFS_CONTAINS_ENCRYPTED_KEY; | |
c59becfc | 1507 | (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */ |
237fead6 MH |
1508 | break; |
1509 | default: | |
1510 | ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: " | |
1511 | "[%d]\n", data[(*packet_size) - 1]); | |
1512 | rc = -ENOSYS; | |
1513 | goto out_free; | |
1514 | } | |
1515 | (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD; | |
1516 | /* TODO: Parametarize; we might actually want userspace to | |
1517 | * decrypt the session key. */ | |
e2bd99ec MH |
1518 | (*new_auth_tok)->session_key.flags &= |
1519 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT); | |
1520 | (*new_auth_tok)->session_key.flags &= | |
1521 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT); | |
237fead6 MH |
1522 | list_add(&auth_tok_list_item->list, auth_tok_list); |
1523 | goto out; | |
1524 | out_free: | |
1525 | (*new_auth_tok) = NULL; | |
1526 | memset(auth_tok_list_item, 0, | |
1527 | sizeof(struct ecryptfs_auth_tok_list_item)); | |
1528 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, | |
1529 | auth_tok_list_item); | |
1530 | out: | |
1531 | if (rc) | |
1532 | (*packet_size) = 0; | |
1533 | return rc; | |
1534 | } | |
1535 | ||
1536 | /** | |
1537 | * parse_tag_11_packet | |
1538 | * @data: The raw bytes of the packet | |
1539 | * @contents: This function writes the data contents of the literal | |
1540 | * packet into this memory location | |
1541 | * @max_contents_bytes: The maximum number of bytes that this function | |
1542 | * is allowed to write into contents | |
1543 | * @tag_11_contents_size: This function writes the size of the parsed | |
1544 | * contents into this memory location; zero on | |
1545 | * error | |
1546 | * @packet_size: This function writes the size of the parsed packet | |
1547 | * into this memory location; zero on error | |
1548 | * @max_packet_size: maximum number of bytes to parse | |
1549 | * | |
1550 | * Returns zero on success; non-zero on error. | |
1551 | */ | |
1552 | static int | |
1553 | parse_tag_11_packet(unsigned char *data, unsigned char *contents, | |
1554 | size_t max_contents_bytes, size_t *tag_11_contents_size, | |
1555 | size_t *packet_size, size_t max_packet_size) | |
1556 | { | |
237fead6 MH |
1557 | size_t body_size; |
1558 | size_t length_size; | |
dddfa461 | 1559 | int rc = 0; |
237fead6 MH |
1560 | |
1561 | (*packet_size) = 0; | |
1562 | (*tag_11_contents_size) = 0; | |
f648104a MH |
1563 | /* This format is inspired by OpenPGP; see RFC 2440 |
1564 | * packet tag 11 | |
1565 | * | |
1566 | * Tag 11 identifier (1 byte) | |
1567 | * Max Tag 11 packet size (max 3 bytes) | |
1568 | * Binary format specifier (1 byte) | |
1569 | * Filename length (1 byte) | |
1570 | * Filename ("_CONSOLE") (8 bytes) | |
1571 | * Modification date (4 bytes) | |
1572 | * Literal data (arbitrary) | |
1573 | * | |
1574 | * We need at least 16 bytes of data for the packet to even be | |
1575 | * valid. | |
237fead6 | 1576 | */ |
f648104a MH |
1577 | if (max_packet_size < 16) { |
1578 | printk(KERN_ERR "Maximum packet size too small\n"); | |
237fead6 MH |
1579 | rc = -EINVAL; |
1580 | goto out; | |
1581 | } | |
237fead6 | 1582 | if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) { |
f648104a | 1583 | printk(KERN_WARNING "Invalid tag 11 packet format\n"); |
237fead6 MH |
1584 | rc = -EINVAL; |
1585 | goto out; | |
1586 | } | |
f66e883e MH |
1587 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1588 | &length_size); | |
5dda6992 | 1589 | if (rc) { |
f648104a | 1590 | printk(KERN_WARNING "Invalid tag 11 packet format\n"); |
237fead6 MH |
1591 | goto out; |
1592 | } | |
f648104a | 1593 | if (body_size < 14) { |
81acbcd6 | 1594 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
237fead6 MH |
1595 | rc = -EINVAL; |
1596 | goto out; | |
1597 | } | |
f648104a MH |
1598 | (*packet_size) += length_size; |
1599 | (*tag_11_contents_size) = (body_size - 14); | |
237fead6 | 1600 | if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) { |
f648104a | 1601 | printk(KERN_ERR "Packet size exceeds max\n"); |
237fead6 MH |
1602 | rc = -EINVAL; |
1603 | goto out; | |
1604 | } | |
6352a293 TH |
1605 | if (unlikely((*tag_11_contents_size) > max_contents_bytes)) { |
1606 | printk(KERN_ERR "Literal data section in tag 11 packet exceeds " | |
1607 | "expected size\n"); | |
1608 | rc = -EINVAL; | |
1609 | goto out; | |
1610 | } | |
237fead6 | 1611 | if (data[(*packet_size)++] != 0x62) { |
f648104a | 1612 | printk(KERN_WARNING "Unrecognizable packet\n"); |
237fead6 MH |
1613 | rc = -EINVAL; |
1614 | goto out; | |
1615 | } | |
237fead6 | 1616 | if (data[(*packet_size)++] != 0x08) { |
f648104a | 1617 | printk(KERN_WARNING "Unrecognizable packet\n"); |
237fead6 MH |
1618 | rc = -EINVAL; |
1619 | goto out; | |
1620 | } | |
f648104a | 1621 | (*packet_size) += 12; /* Ignore filename and modification date */ |
237fead6 MH |
1622 | memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size)); |
1623 | (*packet_size) += (*tag_11_contents_size); | |
237fead6 MH |
1624 | out: |
1625 | if (rc) { | |
1626 | (*packet_size) = 0; | |
1627 | (*tag_11_contents_size) = 0; | |
1628 | } | |
1629 | return rc; | |
1630 | } | |
1631 | ||
f4aad16a MH |
1632 | int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key, |
1633 | struct ecryptfs_auth_tok **auth_tok, | |
1634 | char *sig) | |
1635 | { | |
1636 | int rc = 0; | |
1637 | ||
1638 | (*auth_tok_key) = request_key(&key_type_user, sig, NULL); | |
1639 | if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) { | |
1252cc3b RS |
1640 | (*auth_tok_key) = ecryptfs_get_encrypted_key(sig); |
1641 | if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) { | |
1642 | printk(KERN_ERR "Could not find key with description: [%s]\n", | |
1643 | sig); | |
1644 | rc = process_request_key_err(PTR_ERR(*auth_tok_key)); | |
1645 | (*auth_tok_key) = NULL; | |
1646 | goto out; | |
1647 | } | |
f4aad16a | 1648 | } |
b5695d04 | 1649 | down_write(&(*auth_tok_key)->sem); |
0e1fc5ef | 1650 | rc = ecryptfs_verify_auth_tok_from_key(*auth_tok_key, auth_tok); |
aee683b9 | 1651 | if (rc) { |
b5695d04 | 1652 | up_write(&(*auth_tok_key)->sem); |
aee683b9 RS |
1653 | key_put(*auth_tok_key); |
1654 | (*auth_tok_key) = NULL; | |
0e1fc5ef | 1655 | goto out; |
f4aad16a MH |
1656 | } |
1657 | out: | |
1658 | return rc; | |
1659 | } | |
1660 | ||
f4aad16a | 1661 | /** |
22e78faf MH |
1662 | * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok. |
1663 | * @auth_tok: The passphrase authentication token to use to encrypt the FEK | |
1664 | * @crypt_stat: The cryptographic context | |
237fead6 | 1665 | * |
22e78faf | 1666 | * Returns zero on success; non-zero error otherwise |
237fead6 | 1667 | */ |
f4aad16a MH |
1668 | static int |
1669 | decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, | |
1670 | struct ecryptfs_crypt_stat *crypt_stat) | |
237fead6 | 1671 | { |
ac97b9f9 MH |
1672 | struct scatterlist dst_sg[2]; |
1673 | struct scatterlist src_sg[2]; | |
dd8e2902 | 1674 | struct mutex *tfm_mutex; |
3095e8e3 HX |
1675 | struct crypto_skcipher *tfm; |
1676 | struct skcipher_request *req = NULL; | |
8bba066f | 1677 | int rc = 0; |
237fead6 | 1678 | |
f4aad16a MH |
1679 | if (unlikely(ecryptfs_verbosity > 0)) { |
1680 | ecryptfs_printk( | |
1681 | KERN_DEBUG, "Session key encryption key (size [%d]):\n", | |
1682 | auth_tok->token.password.session_key_encryption_key_bytes); | |
1683 | ecryptfs_dump_hex( | |
1684 | auth_tok->token.password.session_key_encryption_key, | |
1685 | auth_tok->token.password.session_key_encryption_key_bytes); | |
1686 | } | |
3095e8e3 | 1687 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&tfm, &tfm_mutex, |
f4aad16a MH |
1688 | crypt_stat->cipher); |
1689 | if (unlikely(rc)) { | |
1690 | printk(KERN_ERR "Internal error whilst attempting to get " | |
1691 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
1692 | crypt_stat->cipher, rc); | |
1693 | goto out; | |
237fead6 | 1694 | } |
5dda6992 MH |
1695 | rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key, |
1696 | auth_tok->session_key.encrypted_key_size, | |
ac97b9f9 MH |
1697 | src_sg, 2); |
1698 | if (rc < 1 || rc > 2) { | |
f4aad16a MH |
1699 | printk(KERN_ERR "Internal error whilst attempting to convert " |
1700 | "auth_tok->session_key.encrypted_key to scatterlist; " | |
1701 | "expected rc = 1; got rc = [%d]. " | |
1702 | "auth_tok->session_key.encrypted_key_size = [%d]\n", rc, | |
1703 | auth_tok->session_key.encrypted_key_size); | |
1704 | goto out; | |
1705 | } | |
1706 | auth_tok->session_key.decrypted_key_size = | |
1707 | auth_tok->session_key.encrypted_key_size; | |
5dda6992 MH |
1708 | rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key, |
1709 | auth_tok->session_key.decrypted_key_size, | |
ac97b9f9 MH |
1710 | dst_sg, 2); |
1711 | if (rc < 1 || rc > 2) { | |
f4aad16a MH |
1712 | printk(KERN_ERR "Internal error whilst attempting to convert " |
1713 | "auth_tok->session_key.decrypted_key to scatterlist; " | |
1714 | "expected rc = 1; got rc = [%d]\n", rc); | |
1715 | goto out; | |
1716 | } | |
1717 | mutex_lock(tfm_mutex); | |
3095e8e3 HX |
1718 | req = skcipher_request_alloc(tfm, GFP_KERNEL); |
1719 | if (!req) { | |
1720 | mutex_unlock(tfm_mutex); | |
1721 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " | |
1722 | "skcipher_request_alloc for %s\n", __func__, | |
1723 | crypto_skcipher_driver_name(tfm)); | |
1724 | rc = -ENOMEM; | |
1725 | goto out; | |
1726 | } | |
1727 | ||
1728 | skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, | |
1729 | NULL, NULL); | |
1730 | rc = crypto_skcipher_setkey( | |
1731 | tfm, auth_tok->token.password.session_key_encryption_key, | |
f4aad16a MH |
1732 | crypt_stat->key_size); |
1733 | if (unlikely(rc < 0)) { | |
1734 | mutex_unlock(tfm_mutex); | |
e5d9cbde MH |
1735 | printk(KERN_ERR "Error setting key for crypto context\n"); |
1736 | rc = -EINVAL; | |
f4aad16a | 1737 | goto out; |
237fead6 | 1738 | } |
3095e8e3 HX |
1739 | skcipher_request_set_crypt(req, src_sg, dst_sg, |
1740 | auth_tok->session_key.encrypted_key_size, | |
1741 | NULL); | |
1742 | rc = crypto_skcipher_decrypt(req); | |
f4aad16a MH |
1743 | mutex_unlock(tfm_mutex); |
1744 | if (unlikely(rc)) { | |
8bba066f | 1745 | printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc); |
f4aad16a | 1746 | goto out; |
8bba066f | 1747 | } |
237fead6 MH |
1748 | auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; |
1749 | memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, | |
1750 | auth_tok->session_key.decrypted_key_size); | |
e2bd99ec | 1751 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; |
f4aad16a | 1752 | if (unlikely(ecryptfs_verbosity > 0)) { |
f24b3887 | 1753 | ecryptfs_printk(KERN_DEBUG, "FEK of size [%zd]:\n", |
f4aad16a | 1754 | crypt_stat->key_size); |
237fead6 MH |
1755 | ecryptfs_dump_hex(crypt_stat->key, |
1756 | crypt_stat->key_size); | |
f4aad16a | 1757 | } |
237fead6 | 1758 | out: |
3095e8e3 | 1759 | skcipher_request_free(req); |
237fead6 MH |
1760 | return rc; |
1761 | } | |
1762 | ||
1763 | /** | |
1764 | * ecryptfs_parse_packet_set | |
22e78faf MH |
1765 | * @crypt_stat: The cryptographic context |
1766 | * @src: Virtual address of region of memory containing the packets | |
1767 | * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set | |
237fead6 MH |
1768 | * |
1769 | * Get crypt_stat to have the file's session key if the requisite key | |
1770 | * is available to decrypt the session key. | |
1771 | * | |
1772 | * Returns Zero if a valid authentication token was retrieved and | |
1773 | * processed; negative value for file not encrypted or for error | |
1774 | * conditions. | |
1775 | */ | |
1776 | int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat, | |
1777 | unsigned char *src, | |
1778 | struct dentry *ecryptfs_dentry) | |
1779 | { | |
1780 | size_t i = 0; | |
f4aad16a | 1781 | size_t found_auth_tok; |
237fead6 | 1782 | size_t next_packet_is_auth_tok_packet; |
237fead6 | 1783 | struct list_head auth_tok_list; |
dd8e2902 MH |
1784 | struct ecryptfs_auth_tok *matching_auth_tok; |
1785 | struct ecryptfs_auth_tok *candidate_auth_tok; | |
f4aad16a | 1786 | char *candidate_auth_tok_sig; |
237fead6 MH |
1787 | size_t packet_size; |
1788 | struct ecryptfs_auth_tok *new_auth_tok; | |
1789 | unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE]; | |
f4aad16a | 1790 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
237fead6 MH |
1791 | size_t tag_11_contents_size; |
1792 | size_t tag_11_packet_size; | |
aee683b9 | 1793 | struct key *auth_tok_key = NULL; |
dddfa461 | 1794 | int rc = 0; |
237fead6 MH |
1795 | |
1796 | INIT_LIST_HEAD(&auth_tok_list); | |
f4aad16a | 1797 | /* Parse the header to find as many packets as we can; these will be |
237fead6 MH |
1798 | * added the our &auth_tok_list */ |
1799 | next_packet_is_auth_tok_packet = 1; | |
1800 | while (next_packet_is_auth_tok_packet) { | |
09cbfeaf | 1801 | size_t max_packet_size = ((PAGE_SIZE - 8) - i); |
237fead6 MH |
1802 | |
1803 | switch (src[i]) { | |
1804 | case ECRYPTFS_TAG_3_PACKET_TYPE: | |
1805 | rc = parse_tag_3_packet(crypt_stat, | |
1806 | (unsigned char *)&src[i], | |
1807 | &auth_tok_list, &new_auth_tok, | |
1808 | &packet_size, max_packet_size); | |
1809 | if (rc) { | |
1810 | ecryptfs_printk(KERN_ERR, "Error parsing " | |
1811 | "tag 3 packet\n"); | |
1812 | rc = -EIO; | |
1813 | goto out_wipe_list; | |
1814 | } | |
1815 | i += packet_size; | |
1816 | rc = parse_tag_11_packet((unsigned char *)&src[i], | |
1817 | sig_tmp_space, | |
1818 | ECRYPTFS_SIG_SIZE, | |
1819 | &tag_11_contents_size, | |
1820 | &tag_11_packet_size, | |
1821 | max_packet_size); | |
1822 | if (rc) { | |
1823 | ecryptfs_printk(KERN_ERR, "No valid " | |
1824 | "(ecryptfs-specific) literal " | |
1825 | "packet containing " | |
1826 | "authentication token " | |
1827 | "signature found after " | |
1828 | "tag 3 packet\n"); | |
1829 | rc = -EIO; | |
1830 | goto out_wipe_list; | |
1831 | } | |
1832 | i += tag_11_packet_size; | |
1833 | if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) { | |
1834 | ecryptfs_printk(KERN_ERR, "Expected " | |
1835 | "signature of size [%d]; " | |
f24b3887 | 1836 | "read size [%zd]\n", |
237fead6 MH |
1837 | ECRYPTFS_SIG_SIZE, |
1838 | tag_11_contents_size); | |
1839 | rc = -EIO; | |
1840 | goto out_wipe_list; | |
1841 | } | |
1842 | ecryptfs_to_hex(new_auth_tok->token.password.signature, | |
1843 | sig_tmp_space, tag_11_contents_size); | |
1844 | new_auth_tok->token.password.signature[ | |
1845 | ECRYPTFS_PASSWORD_SIG_SIZE] = '\0'; | |
e2bd99ec | 1846 | crypt_stat->flags |= ECRYPTFS_ENCRYPTED; |
237fead6 | 1847 | break; |
dddfa461 MH |
1848 | case ECRYPTFS_TAG_1_PACKET_TYPE: |
1849 | rc = parse_tag_1_packet(crypt_stat, | |
1850 | (unsigned char *)&src[i], | |
1851 | &auth_tok_list, &new_auth_tok, | |
1852 | &packet_size, max_packet_size); | |
1853 | if (rc) { | |
1854 | ecryptfs_printk(KERN_ERR, "Error parsing " | |
1855 | "tag 1 packet\n"); | |
1856 | rc = -EIO; | |
1857 | goto out_wipe_list; | |
1858 | } | |
1859 | i += packet_size; | |
e2bd99ec | 1860 | crypt_stat->flags |= ECRYPTFS_ENCRYPTED; |
dddfa461 | 1861 | break; |
237fead6 MH |
1862 | case ECRYPTFS_TAG_11_PACKET_TYPE: |
1863 | ecryptfs_printk(KERN_WARNING, "Invalid packet set " | |
1864 | "(Tag 11 not allowed by itself)\n"); | |
1865 | rc = -EIO; | |
1866 | goto out_wipe_list; | |
237fead6 | 1867 | default: |
f24b3887 TH |
1868 | ecryptfs_printk(KERN_DEBUG, "No packet at offset [%zd] " |
1869 | "of the file header; hex value of " | |
237fead6 MH |
1870 | "character is [0x%.2x]\n", i, src[i]); |
1871 | next_packet_is_auth_tok_packet = 0; | |
1872 | } | |
1873 | } | |
1874 | if (list_empty(&auth_tok_list)) { | |
f4aad16a MH |
1875 | printk(KERN_ERR "The lower file appears to be a non-encrypted " |
1876 | "eCryptfs file; this is not supported in this version " | |
1877 | "of the eCryptfs kernel module\n"); | |
1878 | rc = -EINVAL; | |
237fead6 MH |
1879 | goto out; |
1880 | } | |
f4aad16a MH |
1881 | /* auth_tok_list contains the set of authentication tokens |
1882 | * parsed from the metadata. We need to find a matching | |
1883 | * authentication token that has the secret component(s) | |
1884 | * necessary to decrypt the EFEK in the auth_tok parsed from | |
1885 | * the metadata. There may be several potential matches, but | |
1886 | * just one will be sufficient to decrypt to get the FEK. */ | |
1887 | find_next_matching_auth_tok: | |
1888 | found_auth_tok = 0; | |
1889 | list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) { | |
237fead6 MH |
1890 | candidate_auth_tok = &auth_tok_list_item->auth_tok; |
1891 | if (unlikely(ecryptfs_verbosity > 0)) { | |
1892 | ecryptfs_printk(KERN_DEBUG, | |
1893 | "Considering cadidate auth tok:\n"); | |
1894 | ecryptfs_dump_auth_tok(candidate_auth_tok); | |
1895 | } | |
5dda6992 MH |
1896 | rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig, |
1897 | candidate_auth_tok); | |
1898 | if (rc) { | |
f4aad16a MH |
1899 | printk(KERN_ERR |
1900 | "Unrecognized candidate auth tok type: [%d]\n", | |
1901 | candidate_auth_tok->token_type); | |
1902 | rc = -EINVAL; | |
1903 | goto out_wipe_list; | |
1904 | } | |
39fac853 | 1905 | rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key, |
aee683b9 | 1906 | &matching_auth_tok, |
9c79f34f | 1907 | crypt_stat->mount_crypt_stat, |
5dda6992 | 1908 | candidate_auth_tok_sig); |
39fac853 | 1909 | if (!rc) { |
dddfa461 | 1910 | found_auth_tok = 1; |
f4aad16a | 1911 | goto found_matching_auth_tok; |
237fead6 MH |
1912 | } |
1913 | } | |
237fead6 | 1914 | if (!found_auth_tok) { |
f4aad16a MH |
1915 | ecryptfs_printk(KERN_ERR, "Could not find a usable " |
1916 | "authentication token\n"); | |
237fead6 MH |
1917 | rc = -EIO; |
1918 | goto out_wipe_list; | |
dddfa461 | 1919 | } |
f4aad16a | 1920 | found_matching_auth_tok: |
e2bd99ec | 1921 | if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
dddfa461 | 1922 | memcpy(&(candidate_auth_tok->token.private_key), |
f4aad16a | 1923 | &(matching_auth_tok->token.private_key), |
dddfa461 | 1924 | sizeof(struct ecryptfs_private_key)); |
b2987a5e TH |
1925 | up_write(&(auth_tok_key->sem)); |
1926 | key_put(auth_tok_key); | |
f4aad16a | 1927 | rc = decrypt_pki_encrypted_session_key(candidate_auth_tok, |
dddfa461 MH |
1928 | crypt_stat); |
1929 | } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) { | |
237fead6 | 1930 | memcpy(&(candidate_auth_tok->token.password), |
f4aad16a | 1931 | &(matching_auth_tok->token.password), |
237fead6 | 1932 | sizeof(struct ecryptfs_password)); |
b2987a5e TH |
1933 | up_write(&(auth_tok_key->sem)); |
1934 | key_put(auth_tok_key); | |
f4aad16a MH |
1935 | rc = decrypt_passphrase_encrypted_session_key( |
1936 | candidate_auth_tok, crypt_stat); | |
b2987a5e TH |
1937 | } else { |
1938 | up_write(&(auth_tok_key->sem)); | |
1939 | key_put(auth_tok_key); | |
1940 | rc = -EINVAL; | |
dddfa461 MH |
1941 | } |
1942 | if (rc) { | |
f4aad16a MH |
1943 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
1944 | ||
1945 | ecryptfs_printk(KERN_WARNING, "Error decrypting the " | |
1946 | "session key for authentication token with sig " | |
1947 | "[%.*s]; rc = [%d]. Removing auth tok " | |
1948 | "candidate from the list and searching for " | |
888d57bb JP |
1949 | "the next match.\n", ECRYPTFS_SIG_SIZE_HEX, |
1950 | candidate_auth_tok_sig, rc); | |
f4aad16a MH |
1951 | list_for_each_entry_safe(auth_tok_list_item, |
1952 | auth_tok_list_item_tmp, | |
1953 | &auth_tok_list, list) { | |
1954 | if (candidate_auth_tok | |
1955 | == &auth_tok_list_item->auth_tok) { | |
1956 | list_del(&auth_tok_list_item->list); | |
1957 | kmem_cache_free( | |
1958 | ecryptfs_auth_tok_list_item_cache, | |
1959 | auth_tok_list_item); | |
1960 | goto find_next_matching_auth_tok; | |
1961 | } | |
1962 | } | |
1963 | BUG(); | |
dddfa461 MH |
1964 | } |
1965 | rc = ecryptfs_compute_root_iv(crypt_stat); | |
1966 | if (rc) { | |
1967 | ecryptfs_printk(KERN_ERR, "Error computing " | |
1968 | "the root IV\n"); | |
1969 | goto out_wipe_list; | |
237fead6 MH |
1970 | } |
1971 | rc = ecryptfs_init_crypt_ctx(crypt_stat); | |
1972 | if (rc) { | |
1973 | ecryptfs_printk(KERN_ERR, "Error initializing crypto " | |
1974 | "context for cipher [%s]; rc = [%d]\n", | |
1975 | crypt_stat->cipher, rc); | |
1976 | } | |
1977 | out_wipe_list: | |
1978 | wipe_auth_tok_list(&auth_tok_list); | |
1979 | out: | |
1980 | return rc; | |
1981 | } | |
f4aad16a | 1982 | |
dddfa461 | 1983 | static int |
b2987a5e TH |
1984 | pki_encrypt_session_key(struct key *auth_tok_key, |
1985 | struct ecryptfs_auth_tok *auth_tok, | |
dddfa461 MH |
1986 | struct ecryptfs_crypt_stat *crypt_stat, |
1987 | struct ecryptfs_key_record *key_rec) | |
1988 | { | |
1989 | struct ecryptfs_msg_ctx *msg_ctx = NULL; | |
624ae528 | 1990 | char *payload = NULL; |
99b373ff | 1991 | size_t payload_len = 0; |
dddfa461 MH |
1992 | struct ecryptfs_message *msg; |
1993 | int rc; | |
1994 | ||
1995 | rc = write_tag_66_packet(auth_tok->token.private_key.signature, | |
9c79f34f MH |
1996 | ecryptfs_code_for_cipher_string( |
1997 | crypt_stat->cipher, | |
1998 | crypt_stat->key_size), | |
624ae528 | 1999 | crypt_stat, &payload, &payload_len); |
b2987a5e TH |
2000 | up_write(&(auth_tok_key->sem)); |
2001 | key_put(auth_tok_key); | |
dddfa461 MH |
2002 | if (rc) { |
2003 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n"); | |
2004 | goto out; | |
2005 | } | |
624ae528 | 2006 | rc = ecryptfs_send_message(payload, payload_len, &msg_ctx); |
dddfa461 | 2007 | if (rc) { |
624ae528 | 2008 | ecryptfs_printk(KERN_ERR, "Error sending message to " |
290502be | 2009 | "ecryptfsd: %d\n", rc); |
dddfa461 MH |
2010 | goto out; |
2011 | } | |
2012 | rc = ecryptfs_wait_for_response(msg_ctx, &msg); | |
2013 | if (rc) { | |
2014 | ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet " | |
2015 | "from the user space daemon\n"); | |
2016 | rc = -EIO; | |
2017 | goto out; | |
2018 | } | |
2019 | rc = parse_tag_67_packet(key_rec, msg); | |
2020 | if (rc) | |
2021 | ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n"); | |
2022 | kfree(msg); | |
2023 | out: | |
624ae528 | 2024 | kfree(payload); |
dddfa461 MH |
2025 | return rc; |
2026 | } | |
2027 | /** | |
2028 | * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet | |
2029 | * @dest: Buffer into which to write the packet | |
22e78faf | 2030 | * @remaining_bytes: Maximum number of bytes that can be writtn |
b2987a5e TH |
2031 | * @auth_tok_key: The authentication token key to unlock and put when done with |
2032 | * @auth_tok | |
22e78faf MH |
2033 | * @auth_tok: The authentication token used for generating the tag 1 packet |
2034 | * @crypt_stat: The cryptographic context | |
2035 | * @key_rec: The key record struct for the tag 1 packet | |
dddfa461 MH |
2036 | * @packet_size: This function will write the number of bytes that end |
2037 | * up constituting the packet; set to zero on error | |
2038 | * | |
2039 | * Returns zero on success; non-zero on error. | |
2040 | */ | |
2041 | static int | |
f4aad16a | 2042 | write_tag_1_packet(char *dest, size_t *remaining_bytes, |
b2987a5e | 2043 | struct key *auth_tok_key, struct ecryptfs_auth_tok *auth_tok, |
dddfa461 | 2044 | struct ecryptfs_crypt_stat *crypt_stat, |
dddfa461 MH |
2045 | struct ecryptfs_key_record *key_rec, size_t *packet_size) |
2046 | { | |
2047 | size_t i; | |
2048 | size_t encrypted_session_key_valid = 0; | |
dddfa461 | 2049 | size_t packet_size_length; |
f4aad16a | 2050 | size_t max_packet_size; |
dddfa461 MH |
2051 | int rc = 0; |
2052 | ||
2053 | (*packet_size) = 0; | |
2054 | ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature, | |
2055 | ECRYPTFS_SIG_SIZE); | |
2056 | encrypted_session_key_valid = 0; | |
2057 | for (i = 0; i < crypt_stat->key_size; i++) | |
2058 | encrypted_session_key_valid |= | |
2059 | auth_tok->session_key.encrypted_key[i]; | |
2060 | if (encrypted_session_key_valid) { | |
2061 | memcpy(key_rec->enc_key, | |
2062 | auth_tok->session_key.encrypted_key, | |
2063 | auth_tok->session_key.encrypted_key_size); | |
b2987a5e TH |
2064 | up_write(&(auth_tok_key->sem)); |
2065 | key_put(auth_tok_key); | |
dddfa461 MH |
2066 | goto encrypted_session_key_set; |
2067 | } | |
2068 | if (auth_tok->session_key.encrypted_key_size == 0) | |
2069 | auth_tok->session_key.encrypted_key_size = | |
2070 | auth_tok->token.private_key.key_size; | |
b2987a5e TH |
2071 | rc = pki_encrypt_session_key(auth_tok_key, auth_tok, crypt_stat, |
2072 | key_rec); | |
dddfa461 | 2073 | if (rc) { |
f66e883e MH |
2074 | printk(KERN_ERR "Failed to encrypt session key via a key " |
2075 | "module; rc = [%d]\n", rc); | |
dddfa461 MH |
2076 | goto out; |
2077 | } | |
2078 | if (ecryptfs_verbosity > 0) { | |
2079 | ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n"); | |
2080 | ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size); | |
2081 | } | |
2082 | encrypted_session_key_set: | |
f4aad16a MH |
2083 | /* This format is inspired by OpenPGP; see RFC 2440 |
2084 | * packet tag 1 */ | |
2085 | max_packet_size = (1 /* Tag 1 identifier */ | |
2086 | + 3 /* Max Tag 1 packet size */ | |
2087 | + 1 /* Version */ | |
2088 | + ECRYPTFS_SIG_SIZE /* Key identifier */ | |
2089 | + 1 /* Cipher identifier */ | |
2090 | + key_rec->enc_key_size); /* Encrypted key size */ | |
2091 | if (max_packet_size > (*remaining_bytes)) { | |
2092 | printk(KERN_ERR "Packet length larger than maximum allowable; " | |
81acbcd6 | 2093 | "need up to [%td] bytes, but there are only [%td] " |
f4aad16a | 2094 | "available\n", max_packet_size, (*remaining_bytes)); |
dddfa461 MH |
2095 | rc = -EINVAL; |
2096 | goto out; | |
2097 | } | |
2098 | dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE; | |
f66e883e MH |
2099 | rc = ecryptfs_write_packet_length(&dest[(*packet_size)], |
2100 | (max_packet_size - 4), | |
2101 | &packet_size_length); | |
dddfa461 MH |
2102 | if (rc) { |
2103 | ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet " | |
2104 | "header; cannot generate packet length\n"); | |
2105 | goto out; | |
2106 | } | |
2107 | (*packet_size) += packet_size_length; | |
2108 | dest[(*packet_size)++] = 0x03; /* version 3 */ | |
2109 | memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE); | |
2110 | (*packet_size) += ECRYPTFS_SIG_SIZE; | |
2111 | dest[(*packet_size)++] = RFC2440_CIPHER_RSA; | |
2112 | memcpy(&dest[(*packet_size)], key_rec->enc_key, | |
2113 | key_rec->enc_key_size); | |
2114 | (*packet_size) += key_rec->enc_key_size; | |
2115 | out: | |
2116 | if (rc) | |
2117 | (*packet_size) = 0; | |
f4aad16a MH |
2118 | else |
2119 | (*remaining_bytes) -= (*packet_size); | |
dddfa461 MH |
2120 | return rc; |
2121 | } | |
237fead6 MH |
2122 | |
2123 | /** | |
2124 | * write_tag_11_packet | |
2125 | * @dest: Target into which Tag 11 packet is to be written | |
22e78faf | 2126 | * @remaining_bytes: Maximum packet length |
237fead6 MH |
2127 | * @contents: Byte array of contents to copy in |
2128 | * @contents_length: Number of bytes in contents | |
2129 | * @packet_length: Length of the Tag 11 packet written; zero on error | |
2130 | * | |
2131 | * Returns zero on success; non-zero on error. | |
2132 | */ | |
2133 | static int | |
81acbcd6 | 2134 | write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents, |
146a4606 | 2135 | size_t contents_length, size_t *packet_length) |
237fead6 | 2136 | { |
237fead6 | 2137 | size_t packet_size_length; |
146a4606 | 2138 | size_t max_packet_size; |
dddfa461 | 2139 | int rc = 0; |
237fead6 MH |
2140 | |
2141 | (*packet_length) = 0; | |
146a4606 MH |
2142 | /* This format is inspired by OpenPGP; see RFC 2440 |
2143 | * packet tag 11 */ | |
2144 | max_packet_size = (1 /* Tag 11 identifier */ | |
2145 | + 3 /* Max Tag 11 packet size */ | |
2146 | + 1 /* Binary format specifier */ | |
2147 | + 1 /* Filename length */ | |
2148 | + 8 /* Filename ("_CONSOLE") */ | |
2149 | + 4 /* Modification date */ | |
2150 | + contents_length); /* Literal data */ | |
2151 | if (max_packet_size > (*remaining_bytes)) { | |
2152 | printk(KERN_ERR "Packet length larger than maximum allowable; " | |
81acbcd6 | 2153 | "need up to [%td] bytes, but there are only [%td] " |
146a4606 | 2154 | "available\n", max_packet_size, (*remaining_bytes)); |
237fead6 | 2155 | rc = -EINVAL; |
237fead6 MH |
2156 | goto out; |
2157 | } | |
237fead6 | 2158 | dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE; |
f66e883e MH |
2159 | rc = ecryptfs_write_packet_length(&dest[(*packet_length)], |
2160 | (max_packet_size - 4), | |
2161 | &packet_size_length); | |
237fead6 | 2162 | if (rc) { |
146a4606 MH |
2163 | printk(KERN_ERR "Error generating tag 11 packet header; cannot " |
2164 | "generate packet length. rc = [%d]\n", rc); | |
237fead6 MH |
2165 | goto out; |
2166 | } | |
2167 | (*packet_length) += packet_size_length; | |
146a4606 | 2168 | dest[(*packet_length)++] = 0x62; /* binary data format specifier */ |
237fead6 MH |
2169 | dest[(*packet_length)++] = 8; |
2170 | memcpy(&dest[(*packet_length)], "_CONSOLE", 8); | |
2171 | (*packet_length) += 8; | |
237fead6 MH |
2172 | memset(&dest[(*packet_length)], 0x00, 4); |
2173 | (*packet_length) += 4; | |
237fead6 MH |
2174 | memcpy(&dest[(*packet_length)], contents, contents_length); |
2175 | (*packet_length) += contents_length; | |
2176 | out: | |
2177 | if (rc) | |
2178 | (*packet_length) = 0; | |
146a4606 MH |
2179 | else |
2180 | (*remaining_bytes) -= (*packet_length); | |
237fead6 MH |
2181 | return rc; |
2182 | } | |
2183 | ||
2184 | /** | |
2185 | * write_tag_3_packet | |
2186 | * @dest: Buffer into which to write the packet | |
22e78faf | 2187 | * @remaining_bytes: Maximum number of bytes that can be written |
237fead6 MH |
2188 | * @auth_tok: Authentication token |
2189 | * @crypt_stat: The cryptographic context | |
2190 | * @key_rec: encrypted key | |
2191 | * @packet_size: This function will write the number of bytes that end | |
2192 | * up constituting the packet; set to zero on error | |
2193 | * | |
2194 | * Returns zero on success; non-zero on error. | |
2195 | */ | |
2196 | static int | |
f4aad16a MH |
2197 | write_tag_3_packet(char *dest, size_t *remaining_bytes, |
2198 | struct ecryptfs_auth_tok *auth_tok, | |
237fead6 MH |
2199 | struct ecryptfs_crypt_stat *crypt_stat, |
2200 | struct ecryptfs_key_record *key_rec, size_t *packet_size) | |
2201 | { | |
237fead6 | 2202 | size_t i; |
237fead6 MH |
2203 | size_t encrypted_session_key_valid = 0; |
2204 | char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES]; | |
ac97b9f9 MH |
2205 | struct scatterlist dst_sg[2]; |
2206 | struct scatterlist src_sg[2]; | |
237fead6 | 2207 | struct mutex *tfm_mutex = NULL; |
19e66a67 | 2208 | u8 cipher_code; |
f4aad16a MH |
2209 | size_t packet_size_length; |
2210 | size_t max_packet_size; | |
2211 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = | |
2212 | crypt_stat->mount_crypt_stat; | |
3095e8e3 HX |
2213 | struct crypto_skcipher *tfm; |
2214 | struct skcipher_request *req; | |
8bba066f | 2215 | int rc = 0; |
237fead6 MH |
2216 | |
2217 | (*packet_size) = 0; | |
dddfa461 | 2218 | ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature, |
237fead6 | 2219 | ECRYPTFS_SIG_SIZE); |
3095e8e3 | 2220 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&tfm, &tfm_mutex, |
f4aad16a MH |
2221 | crypt_stat->cipher); |
2222 | if (unlikely(rc)) { | |
2223 | printk(KERN_ERR "Internal error whilst attempting to get " | |
2224 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
2225 | crypt_stat->cipher, rc); | |
2226 | goto out; | |
2227 | } | |
2228 | if (mount_crypt_stat->global_default_cipher_key_size == 0) { | |
f4aad16a | 2229 | printk(KERN_WARNING "No key size specified at mount; " |
3095e8e3 HX |
2230 | "defaulting to [%d]\n", |
2231 | crypto_skcipher_default_keysize(tfm)); | |
f4aad16a | 2232 | mount_crypt_stat->global_default_cipher_key_size = |
3095e8e3 | 2233 | crypto_skcipher_default_keysize(tfm); |
237fead6 | 2234 | } |
f4aad16a MH |
2235 | if (crypt_stat->key_size == 0) |
2236 | crypt_stat->key_size = | |
2237 | mount_crypt_stat->global_default_cipher_key_size; | |
237fead6 MH |
2238 | if (auth_tok->session_key.encrypted_key_size == 0) |
2239 | auth_tok->session_key.encrypted_key_size = | |
2240 | crypt_stat->key_size; | |
2241 | if (crypt_stat->key_size == 24 | |
2242 | && strcmp("aes", crypt_stat->cipher) == 0) { | |
2243 | memset((crypt_stat->key + 24), 0, 8); | |
2244 | auth_tok->session_key.encrypted_key_size = 32; | |
f4aad16a MH |
2245 | } else |
2246 | auth_tok->session_key.encrypted_key_size = crypt_stat->key_size; | |
dddfa461 | 2247 | key_rec->enc_key_size = |
237fead6 | 2248 | auth_tok->session_key.encrypted_key_size; |
f4aad16a MH |
2249 | encrypted_session_key_valid = 0; |
2250 | for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++) | |
2251 | encrypted_session_key_valid |= | |
2252 | auth_tok->session_key.encrypted_key[i]; | |
2253 | if (encrypted_session_key_valid) { | |
2254 | ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; " | |
2255 | "using auth_tok->session_key.encrypted_key, " | |
f24b3887 | 2256 | "where key_rec->enc_key_size = [%zd]\n", |
f4aad16a MH |
2257 | key_rec->enc_key_size); |
2258 | memcpy(key_rec->enc_key, | |
2259 | auth_tok->session_key.encrypted_key, | |
2260 | key_rec->enc_key_size); | |
2261 | goto encrypted_session_key_set; | |
2262 | } | |
dddfa461 MH |
2263 | if (auth_tok->token.password.flags & |
2264 | ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) { | |
237fead6 MH |
2265 | ecryptfs_printk(KERN_DEBUG, "Using previously generated " |
2266 | "session key encryption key of size [%d]\n", | |
2267 | auth_tok->token.password. | |
2268 | session_key_encryption_key_bytes); | |
2269 | memcpy(session_key_encryption_key, | |
2270 | auth_tok->token.password.session_key_encryption_key, | |
2271 | crypt_stat->key_size); | |
2272 | ecryptfs_printk(KERN_DEBUG, | |
df2e301f | 2273 | "Cached session key encryption key:\n"); |
237fead6 MH |
2274 | if (ecryptfs_verbosity > 0) |
2275 | ecryptfs_dump_hex(session_key_encryption_key, 16); | |
2276 | } | |
2277 | if (unlikely(ecryptfs_verbosity > 0)) { | |
2278 | ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n"); | |
2279 | ecryptfs_dump_hex(session_key_encryption_key, 16); | |
2280 | } | |
5dda6992 | 2281 | rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size, |
ac97b9f9 MH |
2282 | src_sg, 2); |
2283 | if (rc < 1 || rc > 2) { | |
237fead6 | 2284 | ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
f4aad16a | 2285 | "for crypt_stat session key; expected rc = 1; " |
f24b3887 | 2286 | "got rc = [%d]. key_rec->enc_key_size = [%zd]\n", |
f4aad16a | 2287 | rc, key_rec->enc_key_size); |
237fead6 MH |
2288 | rc = -ENOMEM; |
2289 | goto out; | |
2290 | } | |
5dda6992 | 2291 | rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size, |
ac97b9f9 MH |
2292 | dst_sg, 2); |
2293 | if (rc < 1 || rc > 2) { | |
237fead6 | 2294 | ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
f4aad16a MH |
2295 | "for crypt_stat encrypted session key; " |
2296 | "expected rc = 1; got rc = [%d]. " | |
f24b3887 | 2297 | "key_rec->enc_key_size = [%zd]\n", rc, |
f4aad16a | 2298 | key_rec->enc_key_size); |
237fead6 MH |
2299 | rc = -ENOMEM; |
2300 | goto out; | |
2301 | } | |
f4aad16a | 2302 | mutex_lock(tfm_mutex); |
3095e8e3 HX |
2303 | rc = crypto_skcipher_setkey(tfm, session_key_encryption_key, |
2304 | crypt_stat->key_size); | |
237fead6 | 2305 | if (rc < 0) { |
f4aad16a | 2306 | mutex_unlock(tfm_mutex); |
237fead6 | 2307 | ecryptfs_printk(KERN_ERR, "Error setting key for crypto " |
8bba066f | 2308 | "context; rc = [%d]\n", rc); |
237fead6 MH |
2309 | goto out; |
2310 | } | |
3095e8e3 HX |
2311 | |
2312 | req = skcipher_request_alloc(tfm, GFP_KERNEL); | |
2313 | if (!req) { | |
2314 | mutex_unlock(tfm_mutex); | |
2315 | ecryptfs_printk(KERN_ERR, "Out of kernel memory whilst " | |
2316 | "attempting to skcipher_request_alloc for " | |
2317 | "%s\n", crypto_skcipher_driver_name(tfm)); | |
2318 | rc = -ENOMEM; | |
2319 | goto out; | |
2320 | } | |
2321 | ||
2322 | skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, | |
2323 | NULL, NULL); | |
2324 | ||
237fead6 | 2325 | rc = 0; |
f24b3887 | 2326 | ecryptfs_printk(KERN_DEBUG, "Encrypting [%zd] bytes of the key\n", |
237fead6 | 2327 | crypt_stat->key_size); |
3095e8e3 HX |
2328 | skcipher_request_set_crypt(req, src_sg, dst_sg, |
2329 | (*key_rec).enc_key_size, NULL); | |
2330 | rc = crypto_skcipher_encrypt(req); | |
f4aad16a | 2331 | mutex_unlock(tfm_mutex); |
3095e8e3 | 2332 | skcipher_request_free(req); |
8bba066f MH |
2333 | if (rc) { |
2334 | printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc); | |
2335 | goto out; | |
2336 | } | |
237fead6 | 2337 | ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n"); |
f4aad16a | 2338 | if (ecryptfs_verbosity > 0) { |
f24b3887 | 2339 | ecryptfs_printk(KERN_DEBUG, "EFEK of size [%zd]:\n", |
f4aad16a | 2340 | key_rec->enc_key_size); |
dddfa461 MH |
2341 | ecryptfs_dump_hex(key_rec->enc_key, |
2342 | key_rec->enc_key_size); | |
237fead6 | 2343 | } |
f4aad16a MH |
2344 | encrypted_session_key_set: |
2345 | /* This format is inspired by OpenPGP; see RFC 2440 | |
2346 | * packet tag 3 */ | |
2347 | max_packet_size = (1 /* Tag 3 identifier */ | |
2348 | + 3 /* Max Tag 3 packet size */ | |
2349 | + 1 /* Version */ | |
2350 | + 1 /* Cipher code */ | |
2351 | + 1 /* S2K specifier */ | |
2352 | + 1 /* Hash identifier */ | |
2353 | + ECRYPTFS_SALT_SIZE /* Salt */ | |
2354 | + 1 /* Hash iterations */ | |
2355 | + key_rec->enc_key_size); /* Encrypted key size */ | |
2356 | if (max_packet_size > (*remaining_bytes)) { | |
81acbcd6 AM |
2357 | printk(KERN_ERR "Packet too large; need up to [%td] bytes, but " |
2358 | "there are only [%td] available\n", max_packet_size, | |
f4aad16a | 2359 | (*remaining_bytes)); |
237fead6 MH |
2360 | rc = -EINVAL; |
2361 | goto out; | |
2362 | } | |
237fead6 | 2363 | dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE; |
f4aad16a MH |
2364 | /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3) |
2365 | * to get the number of octets in the actual Tag 3 packet */ | |
f66e883e MH |
2366 | rc = ecryptfs_write_packet_length(&dest[(*packet_size)], |
2367 | (max_packet_size - 4), | |
2368 | &packet_size_length); | |
237fead6 | 2369 | if (rc) { |
f4aad16a MH |
2370 | printk(KERN_ERR "Error generating tag 3 packet header; cannot " |
2371 | "generate packet length. rc = [%d]\n", rc); | |
237fead6 MH |
2372 | goto out; |
2373 | } | |
2374 | (*packet_size) += packet_size_length; | |
2375 | dest[(*packet_size)++] = 0x04; /* version 4 */ | |
f4aad16a MH |
2376 | /* TODO: Break from RFC2440 so that arbitrary ciphers can be |
2377 | * specified with strings */ | |
9c79f34f MH |
2378 | cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher, |
2379 | crypt_stat->key_size); | |
237fead6 MH |
2380 | if (cipher_code == 0) { |
2381 | ecryptfs_printk(KERN_WARNING, "Unable to generate code for " | |
2382 | "cipher [%s]\n", crypt_stat->cipher); | |
2383 | rc = -EINVAL; | |
2384 | goto out; | |
2385 | } | |
2386 | dest[(*packet_size)++] = cipher_code; | |
2387 | dest[(*packet_size)++] = 0x03; /* S2K */ | |
2388 | dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */ | |
2389 | memcpy(&dest[(*packet_size)], auth_tok->token.password.salt, | |
2390 | ECRYPTFS_SALT_SIZE); | |
2391 | (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */ | |
2392 | dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */ | |
dddfa461 MH |
2393 | memcpy(&dest[(*packet_size)], key_rec->enc_key, |
2394 | key_rec->enc_key_size); | |
2395 | (*packet_size) += key_rec->enc_key_size; | |
237fead6 | 2396 | out: |
237fead6 MH |
2397 | if (rc) |
2398 | (*packet_size) = 0; | |
f4aad16a MH |
2399 | else |
2400 | (*remaining_bytes) -= (*packet_size); | |
237fead6 MH |
2401 | return rc; |
2402 | } | |
2403 | ||
eb95e7ff MH |
2404 | struct kmem_cache *ecryptfs_key_record_cache; |
2405 | ||
237fead6 MH |
2406 | /** |
2407 | * ecryptfs_generate_key_packet_set | |
22e78faf | 2408 | * @dest_base: Virtual address from which to write the key record set |
237fead6 MH |
2409 | * @crypt_stat: The cryptographic context from which the |
2410 | * authentication tokens will be retrieved | |
2411 | * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat | |
2412 | * for the global parameters | |
2413 | * @len: The amount written | |
2414 | * @max: The maximum amount of data allowed to be written | |
2415 | * | |
2416 | * Generates a key packet set and writes it to the virtual address | |
2417 | * passed in. | |
2418 | * | |
2419 | * Returns zero on success; non-zero on error. | |
2420 | */ | |
2421 | int | |
2422 | ecryptfs_generate_key_packet_set(char *dest_base, | |
2423 | struct ecryptfs_crypt_stat *crypt_stat, | |
2424 | struct dentry *ecryptfs_dentry, size_t *len, | |
2425 | size_t max) | |
2426 | { | |
237fead6 | 2427 | struct ecryptfs_auth_tok *auth_tok; |
0e1fc5ef | 2428 | struct key *auth_tok_key = NULL; |
237fead6 MH |
2429 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
2430 | &ecryptfs_superblock_to_private( | |
2431 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
2432 | size_t written; | |
eb95e7ff | 2433 | struct ecryptfs_key_record *key_rec; |
f4aad16a | 2434 | struct ecryptfs_key_sig *key_sig; |
dddfa461 | 2435 | int rc = 0; |
237fead6 MH |
2436 | |
2437 | (*len) = 0; | |
f4aad16a | 2438 | mutex_lock(&crypt_stat->keysig_list_mutex); |
eb95e7ff MH |
2439 | key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL); |
2440 | if (!key_rec) { | |
2441 | rc = -ENOMEM; | |
2442 | goto out; | |
2443 | } | |
f4aad16a MH |
2444 | list_for_each_entry(key_sig, &crypt_stat->keysig_list, |
2445 | crypt_stat_list) { | |
2446 | memset(key_rec, 0, sizeof(*key_rec)); | |
0e1fc5ef RS |
2447 | rc = ecryptfs_find_global_auth_tok_for_sig(&auth_tok_key, |
2448 | &auth_tok, | |
f4aad16a MH |
2449 | mount_crypt_stat, |
2450 | key_sig->keysig); | |
2451 | if (rc) { | |
0e1fc5ef RS |
2452 | printk(KERN_WARNING "Unable to retrieve auth tok with " |
2453 | "sig = [%s]\n", key_sig->keysig); | |
2454 | rc = process_find_global_auth_tok_for_sig_err(rc); | |
f4aad16a MH |
2455 | goto out_free; |
2456 | } | |
237fead6 MH |
2457 | if (auth_tok->token_type == ECRYPTFS_PASSWORD) { |
2458 | rc = write_tag_3_packet((dest_base + (*len)), | |
f4aad16a | 2459 | &max, auth_tok, |
eb95e7ff | 2460 | crypt_stat, key_rec, |
237fead6 | 2461 | &written); |
b2987a5e TH |
2462 | up_write(&(auth_tok_key->sem)); |
2463 | key_put(auth_tok_key); | |
237fead6 MH |
2464 | if (rc) { |
2465 | ecryptfs_printk(KERN_WARNING, "Error " | |
2466 | "writing tag 3 packet\n"); | |
eb95e7ff | 2467 | goto out_free; |
237fead6 MH |
2468 | } |
2469 | (*len) += written; | |
2470 | /* Write auth tok signature packet */ | |
f4aad16a MH |
2471 | rc = write_tag_11_packet((dest_base + (*len)), &max, |
2472 | key_rec->sig, | |
2473 | ECRYPTFS_SIG_SIZE, &written); | |
237fead6 MH |
2474 | if (rc) { |
2475 | ecryptfs_printk(KERN_ERR, "Error writing " | |
2476 | "auth tok signature packet\n"); | |
eb95e7ff | 2477 | goto out_free; |
237fead6 MH |
2478 | } |
2479 | (*len) += written; | |
dddfa461 | 2480 | } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
b2987a5e TH |
2481 | rc = write_tag_1_packet(dest_base + (*len), &max, |
2482 | auth_tok_key, auth_tok, | |
f4aad16a | 2483 | crypt_stat, key_rec, &written); |
dddfa461 MH |
2484 | if (rc) { |
2485 | ecryptfs_printk(KERN_WARNING, "Error " | |
2486 | "writing tag 1 packet\n"); | |
eb95e7ff | 2487 | goto out_free; |
dddfa461 MH |
2488 | } |
2489 | (*len) += written; | |
237fead6 | 2490 | } else { |
b2987a5e TH |
2491 | up_write(&(auth_tok_key->sem)); |
2492 | key_put(auth_tok_key); | |
237fead6 MH |
2493 | ecryptfs_printk(KERN_WARNING, "Unsupported " |
2494 | "authentication token type\n"); | |
2495 | rc = -EINVAL; | |
eb95e7ff | 2496 | goto out_free; |
237fead6 | 2497 | } |
f4aad16a MH |
2498 | } |
2499 | if (likely(max > 0)) { | |
237fead6 MH |
2500 | dest_base[(*len)] = 0x00; |
2501 | } else { | |
2502 | ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n"); | |
2503 | rc = -EIO; | |
2504 | } | |
eb95e7ff MH |
2505 | out_free: |
2506 | kmem_cache_free(ecryptfs_key_record_cache, key_rec); | |
237fead6 MH |
2507 | out: |
2508 | if (rc) | |
2509 | (*len) = 0; | |
f4aad16a MH |
2510 | mutex_unlock(&crypt_stat->keysig_list_mutex); |
2511 | return rc; | |
2512 | } | |
2513 | ||
2514 | struct kmem_cache *ecryptfs_key_sig_cache; | |
2515 | ||
2516 | int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig) | |
2517 | { | |
2518 | struct ecryptfs_key_sig *new_key_sig; | |
f4aad16a MH |
2519 | |
2520 | new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL); | |
2521 | if (!new_key_sig) { | |
f4aad16a MH |
2522 | printk(KERN_ERR |
2523 | "Error allocating from ecryptfs_key_sig_cache\n"); | |
aa06117f | 2524 | return -ENOMEM; |
f4aad16a MH |
2525 | } |
2526 | memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX); | |
7762e230 | 2527 | new_key_sig->keysig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
aa06117f | 2528 | /* Caller must hold keysig_list_mutex */ |
f4aad16a | 2529 | list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list); |
aa06117f RD |
2530 | |
2531 | return 0; | |
237fead6 | 2532 | } |
f4aad16a MH |
2533 | |
2534 | struct kmem_cache *ecryptfs_global_auth_tok_cache; | |
2535 | ||
2536 | int | |
2537 | ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
84814d64 | 2538 | char *sig, u32 global_auth_tok_flags) |
f4aad16a MH |
2539 | { |
2540 | struct ecryptfs_global_auth_tok *new_auth_tok; | |
2541 | int rc = 0; | |
2542 | ||
459e2164 | 2543 | new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache, |
f4aad16a MH |
2544 | GFP_KERNEL); |
2545 | if (!new_auth_tok) { | |
2546 | rc = -ENOMEM; | |
2547 | printk(KERN_ERR "Error allocating from " | |
2548 | "ecryptfs_global_auth_tok_cache\n"); | |
2549 | goto out; | |
2550 | } | |
2551 | memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX); | |
84814d64 | 2552 | new_auth_tok->flags = global_auth_tok_flags; |
f4aad16a MH |
2553 | new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
2554 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
2555 | list_add(&new_auth_tok->mount_crypt_stat_list, | |
2556 | &mount_crypt_stat->global_auth_tok_list); | |
f4aad16a MH |
2557 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); |
2558 | out: | |
2559 | return rc; | |
2560 | } | |
2561 |