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Commit | Line | Data |
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237fead6 MH |
1 | /** |
2 | * eCryptfs: Linux filesystem encryption layer | |
3 | * In-kernel key management code. Includes functions to parse and | |
4 | * write authentication token-related packets with the underlying | |
5 | * file. | |
6 | * | |
7 | * Copyright (C) 2004-2006 International Business Machines Corp. | |
8 | * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com> | |
9 | * Michael C. Thompson <mcthomps@us.ibm.com> | |
dddfa461 | 10 | * Trevor S. Highland <trevor.highland@gmail.com> |
237fead6 MH |
11 | * |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU General Public License as | |
14 | * published by the Free Software Foundation; either version 2 of the | |
15 | * License, or (at your option) any later version. | |
16 | * | |
17 | * This program is distributed in the hope that it will be useful, but | |
18 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
20 | * General Public License for more details. | |
21 | * | |
22 | * You should have received a copy of the GNU General Public License | |
23 | * along with this program; if not, write to the Free Software | |
24 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
25 | * 02111-1307, USA. | |
26 | */ | |
27 | ||
28 | #include <linux/string.h> | |
237fead6 MH |
29 | #include <linux/syscalls.h> |
30 | #include <linux/pagemap.h> | |
31 | #include <linux/key.h> | |
32 | #include <linux/random.h> | |
33 | #include <linux/crypto.h> | |
34 | #include <linux/scatterlist.h> | |
5a0e3ad6 | 35 | #include <linux/slab.h> |
237fead6 MH |
36 | #include "ecryptfs_kernel.h" |
37 | ||
38 | /** | |
39 | * request_key returned an error instead of a valid key address; | |
40 | * determine the type of error, make appropriate log entries, and | |
41 | * return an error code. | |
42 | */ | |
cd9d67df | 43 | static int process_request_key_err(long err_code) |
237fead6 MH |
44 | { |
45 | int rc = 0; | |
46 | ||
47 | switch (err_code) { | |
982363c9 | 48 | case -ENOKEY: |
237fead6 MH |
49 | ecryptfs_printk(KERN_WARNING, "No key\n"); |
50 | rc = -ENOENT; | |
51 | break; | |
982363c9 | 52 | case -EKEYEXPIRED: |
237fead6 MH |
53 | ecryptfs_printk(KERN_WARNING, "Key expired\n"); |
54 | rc = -ETIME; | |
55 | break; | |
982363c9 | 56 | case -EKEYREVOKED: |
237fead6 MH |
57 | ecryptfs_printk(KERN_WARNING, "Key revoked\n"); |
58 | rc = -EINVAL; | |
59 | break; | |
60 | default: | |
61 | ecryptfs_printk(KERN_WARNING, "Unknown error code: " | |
62 | "[0x%.16x]\n", err_code); | |
63 | rc = -EINVAL; | |
64 | } | |
65 | return rc; | |
66 | } | |
67 | ||
237fead6 | 68 | /** |
f66e883e | 69 | * ecryptfs_parse_packet_length |
237fead6 MH |
70 | * @data: Pointer to memory containing length at offset |
71 | * @size: This function writes the decoded size to this memory | |
72 | * address; zero on error | |
73 | * @length_size: The number of bytes occupied by the encoded length | |
74 | * | |
22e78faf | 75 | * Returns zero on success; non-zero on error |
237fead6 | 76 | */ |
f66e883e MH |
77 | int ecryptfs_parse_packet_length(unsigned char *data, size_t *size, |
78 | size_t *length_size) | |
237fead6 MH |
79 | { |
80 | int rc = 0; | |
81 | ||
82 | (*length_size) = 0; | |
83 | (*size) = 0; | |
84 | if (data[0] < 192) { | |
85 | /* One-byte length */ | |
dddfa461 | 86 | (*size) = (unsigned char)data[0]; |
237fead6 MH |
87 | (*length_size) = 1; |
88 | } else if (data[0] < 224) { | |
89 | /* Two-byte length */ | |
dddfa461 MH |
90 | (*size) = (((unsigned char)(data[0]) - 192) * 256); |
91 | (*size) += ((unsigned char)(data[1]) + 192); | |
237fead6 MH |
92 | (*length_size) = 2; |
93 | } else if (data[0] == 255) { | |
94 | /* Five-byte length; we're not supposed to see this */ | |
95 | ecryptfs_printk(KERN_ERR, "Five-byte packet length not " | |
96 | "supported\n"); | |
97 | rc = -EINVAL; | |
98 | goto out; | |
99 | } else { | |
100 | ecryptfs_printk(KERN_ERR, "Error parsing packet length\n"); | |
101 | rc = -EINVAL; | |
102 | goto out; | |
103 | } | |
104 | out: | |
105 | return rc; | |
106 | } | |
107 | ||
108 | /** | |
f66e883e | 109 | * ecryptfs_write_packet_length |
22e78faf MH |
110 | * @dest: The byte array target into which to write the length. Must |
111 | * have at least 5 bytes allocated. | |
237fead6 | 112 | * @size: The length to write. |
22e78faf MH |
113 | * @packet_size_length: The number of bytes used to encode the packet |
114 | * length is written to this address. | |
237fead6 MH |
115 | * |
116 | * Returns zero on success; non-zero on error. | |
117 | */ | |
f66e883e MH |
118 | int ecryptfs_write_packet_length(char *dest, size_t size, |
119 | size_t *packet_size_length) | |
237fead6 MH |
120 | { |
121 | int rc = 0; | |
122 | ||
123 | if (size < 192) { | |
124 | dest[0] = size; | |
125 | (*packet_size_length) = 1; | |
126 | } else if (size < 65536) { | |
127 | dest[0] = (((size - 192) / 256) + 192); | |
128 | dest[1] = ((size - 192) % 256); | |
129 | (*packet_size_length) = 2; | |
130 | } else { | |
131 | rc = -EINVAL; | |
132 | ecryptfs_printk(KERN_WARNING, | |
133 | "Unsupported packet size: [%d]\n", size); | |
134 | } | |
135 | return rc; | |
136 | } | |
137 | ||
dddfa461 MH |
138 | static int |
139 | write_tag_64_packet(char *signature, struct ecryptfs_session_key *session_key, | |
140 | char **packet, size_t *packet_len) | |
141 | { | |
142 | size_t i = 0; | |
143 | size_t data_len; | |
144 | size_t packet_size_len; | |
145 | char *message; | |
146 | int rc; | |
147 | ||
148 | /* | |
149 | * ***** TAG 64 Packet Format ***** | |
150 | * | Content Type | 1 byte | | |
151 | * | Key Identifier Size | 1 or 2 bytes | | |
152 | * | Key Identifier | arbitrary | | |
153 | * | Encrypted File Encryption Key Size | 1 or 2 bytes | | |
154 | * | Encrypted File Encryption Key | arbitrary | | |
155 | */ | |
156 | data_len = (5 + ECRYPTFS_SIG_SIZE_HEX | |
157 | + session_key->encrypted_key_size); | |
158 | *packet = kmalloc(data_len, GFP_KERNEL); | |
159 | message = *packet; | |
160 | if (!message) { | |
161 | ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n"); | |
162 | rc = -ENOMEM; | |
163 | goto out; | |
164 | } | |
165 | message[i++] = ECRYPTFS_TAG_64_PACKET_TYPE; | |
f66e883e MH |
166 | rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX, |
167 | &packet_size_len); | |
dddfa461 MH |
168 | if (rc) { |
169 | ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet " | |
170 | "header; cannot generate packet length\n"); | |
171 | goto out; | |
172 | } | |
173 | i += packet_size_len; | |
174 | memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX); | |
175 | i += ECRYPTFS_SIG_SIZE_HEX; | |
f66e883e MH |
176 | rc = ecryptfs_write_packet_length(&message[i], |
177 | session_key->encrypted_key_size, | |
178 | &packet_size_len); | |
dddfa461 MH |
179 | if (rc) { |
180 | ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet " | |
181 | "header; cannot generate packet length\n"); | |
182 | goto out; | |
183 | } | |
184 | i += packet_size_len; | |
185 | memcpy(&message[i], session_key->encrypted_key, | |
186 | session_key->encrypted_key_size); | |
187 | i += session_key->encrypted_key_size; | |
188 | *packet_len = i; | |
189 | out: | |
190 | return rc; | |
191 | } | |
192 | ||
193 | static int | |
19e66a67 | 194 | parse_tag_65_packet(struct ecryptfs_session_key *session_key, u8 *cipher_code, |
dddfa461 MH |
195 | struct ecryptfs_message *msg) |
196 | { | |
197 | size_t i = 0; | |
198 | char *data; | |
199 | size_t data_len; | |
200 | size_t m_size; | |
201 | size_t message_len; | |
202 | u16 checksum = 0; | |
203 | u16 expected_checksum = 0; | |
204 | int rc; | |
205 | ||
206 | /* | |
207 | * ***** TAG 65 Packet Format ***** | |
208 | * | Content Type | 1 byte | | |
209 | * | Status Indicator | 1 byte | | |
210 | * | File Encryption Key Size | 1 or 2 bytes | | |
211 | * | File Encryption Key | arbitrary | | |
212 | */ | |
213 | message_len = msg->data_len; | |
214 | data = msg->data; | |
215 | if (message_len < 4) { | |
216 | rc = -EIO; | |
217 | goto out; | |
218 | } | |
219 | if (data[i++] != ECRYPTFS_TAG_65_PACKET_TYPE) { | |
220 | ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_65\n"); | |
221 | rc = -EIO; | |
222 | goto out; | |
223 | } | |
224 | if (data[i++]) { | |
225 | ecryptfs_printk(KERN_ERR, "Status indicator has non-zero value " | |
226 | "[%d]\n", data[i-1]); | |
227 | rc = -EIO; | |
228 | goto out; | |
229 | } | |
f66e883e | 230 | rc = ecryptfs_parse_packet_length(&data[i], &m_size, &data_len); |
dddfa461 MH |
231 | if (rc) { |
232 | ecryptfs_printk(KERN_WARNING, "Error parsing packet length; " | |
233 | "rc = [%d]\n", rc); | |
234 | goto out; | |
235 | } | |
236 | i += data_len; | |
237 | if (message_len < (i + m_size)) { | |
624ae528 TH |
238 | ecryptfs_printk(KERN_ERR, "The message received from ecryptfsd " |
239 | "is shorter than expected\n"); | |
dddfa461 MH |
240 | rc = -EIO; |
241 | goto out; | |
242 | } | |
243 | if (m_size < 3) { | |
244 | ecryptfs_printk(KERN_ERR, | |
245 | "The decrypted key is not long enough to " | |
246 | "include a cipher code and checksum\n"); | |
247 | rc = -EIO; | |
248 | goto out; | |
249 | } | |
250 | *cipher_code = data[i++]; | |
251 | /* The decrypted key includes 1 byte cipher code and 2 byte checksum */ | |
252 | session_key->decrypted_key_size = m_size - 3; | |
253 | if (session_key->decrypted_key_size > ECRYPTFS_MAX_KEY_BYTES) { | |
254 | ecryptfs_printk(KERN_ERR, "key_size [%d] larger than " | |
255 | "the maximum key size [%d]\n", | |
256 | session_key->decrypted_key_size, | |
257 | ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES); | |
258 | rc = -EIO; | |
259 | goto out; | |
260 | } | |
261 | memcpy(session_key->decrypted_key, &data[i], | |
262 | session_key->decrypted_key_size); | |
263 | i += session_key->decrypted_key_size; | |
264 | expected_checksum += (unsigned char)(data[i++]) << 8; | |
265 | expected_checksum += (unsigned char)(data[i++]); | |
266 | for (i = 0; i < session_key->decrypted_key_size; i++) | |
267 | checksum += session_key->decrypted_key[i]; | |
268 | if (expected_checksum != checksum) { | |
269 | ecryptfs_printk(KERN_ERR, "Invalid checksum for file " | |
270 | "encryption key; expected [%x]; calculated " | |
271 | "[%x]\n", expected_checksum, checksum); | |
272 | rc = -EIO; | |
273 | } | |
274 | out: | |
275 | return rc; | |
276 | } | |
277 | ||
278 | ||
279 | static int | |
19e66a67 | 280 | write_tag_66_packet(char *signature, u8 cipher_code, |
dddfa461 MH |
281 | struct ecryptfs_crypt_stat *crypt_stat, char **packet, |
282 | size_t *packet_len) | |
283 | { | |
284 | size_t i = 0; | |
285 | size_t j; | |
286 | size_t data_len; | |
287 | size_t checksum = 0; | |
288 | size_t packet_size_len; | |
289 | char *message; | |
290 | int rc; | |
291 | ||
292 | /* | |
293 | * ***** TAG 66 Packet Format ***** | |
294 | * | Content Type | 1 byte | | |
295 | * | Key Identifier Size | 1 or 2 bytes | | |
296 | * | Key Identifier | arbitrary | | |
297 | * | File Encryption Key Size | 1 or 2 bytes | | |
298 | * | File Encryption Key | arbitrary | | |
299 | */ | |
300 | data_len = (5 + ECRYPTFS_SIG_SIZE_HEX + crypt_stat->key_size); | |
301 | *packet = kmalloc(data_len, GFP_KERNEL); | |
302 | message = *packet; | |
303 | if (!message) { | |
304 | ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n"); | |
305 | rc = -ENOMEM; | |
306 | goto out; | |
307 | } | |
308 | message[i++] = ECRYPTFS_TAG_66_PACKET_TYPE; | |
f66e883e MH |
309 | rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX, |
310 | &packet_size_len); | |
dddfa461 MH |
311 | if (rc) { |
312 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet " | |
313 | "header; cannot generate packet length\n"); | |
314 | goto out; | |
315 | } | |
316 | i += packet_size_len; | |
317 | memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX); | |
318 | i += ECRYPTFS_SIG_SIZE_HEX; | |
319 | /* The encrypted key includes 1 byte cipher code and 2 byte checksum */ | |
f66e883e MH |
320 | rc = ecryptfs_write_packet_length(&message[i], crypt_stat->key_size + 3, |
321 | &packet_size_len); | |
dddfa461 MH |
322 | if (rc) { |
323 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet " | |
324 | "header; cannot generate packet length\n"); | |
325 | goto out; | |
326 | } | |
327 | i += packet_size_len; | |
328 | message[i++] = cipher_code; | |
329 | memcpy(&message[i], crypt_stat->key, crypt_stat->key_size); | |
330 | i += crypt_stat->key_size; | |
331 | for (j = 0; j < crypt_stat->key_size; j++) | |
332 | checksum += crypt_stat->key[j]; | |
333 | message[i++] = (checksum / 256) % 256; | |
334 | message[i++] = (checksum % 256); | |
335 | *packet_len = i; | |
336 | out: | |
337 | return rc; | |
338 | } | |
339 | ||
340 | static int | |
341 | parse_tag_67_packet(struct ecryptfs_key_record *key_rec, | |
342 | struct ecryptfs_message *msg) | |
343 | { | |
344 | size_t i = 0; | |
345 | char *data; | |
346 | size_t data_len; | |
347 | size_t message_len; | |
348 | int rc; | |
349 | ||
350 | /* | |
351 | * ***** TAG 65 Packet Format ***** | |
352 | * | Content Type | 1 byte | | |
353 | * | Status Indicator | 1 byte | | |
354 | * | Encrypted File Encryption Key Size | 1 or 2 bytes | | |
355 | * | Encrypted File Encryption Key | arbitrary | | |
356 | */ | |
357 | message_len = msg->data_len; | |
358 | data = msg->data; | |
359 | /* verify that everything through the encrypted FEK size is present */ | |
360 | if (message_len < 4) { | |
361 | rc = -EIO; | |
df261c52 | 362 | printk(KERN_ERR "%s: message_len is [%zd]; minimum acceptable " |
f66e883e | 363 | "message length is [%d]\n", __func__, message_len, 4); |
dddfa461 MH |
364 | goto out; |
365 | } | |
366 | if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) { | |
dddfa461 | 367 | rc = -EIO; |
f66e883e MH |
368 | printk(KERN_ERR "%s: Type should be ECRYPTFS_TAG_67\n", |
369 | __func__); | |
dddfa461 MH |
370 | goto out; |
371 | } | |
372 | if (data[i++]) { | |
dddfa461 | 373 | rc = -EIO; |
f66e883e MH |
374 | printk(KERN_ERR "%s: Status indicator has non zero " |
375 | "value [%d]\n", __func__, data[i-1]); | |
376 | ||
dddfa461 MH |
377 | goto out; |
378 | } | |
f66e883e MH |
379 | rc = ecryptfs_parse_packet_length(&data[i], &key_rec->enc_key_size, |
380 | &data_len); | |
dddfa461 MH |
381 | if (rc) { |
382 | ecryptfs_printk(KERN_WARNING, "Error parsing packet length; " | |
383 | "rc = [%d]\n", rc); | |
384 | goto out; | |
385 | } | |
386 | i += data_len; | |
387 | if (message_len < (i + key_rec->enc_key_size)) { | |
dddfa461 | 388 | rc = -EIO; |
df261c52 | 389 | printk(KERN_ERR "%s: message_len [%zd]; max len is [%zd]\n", |
f66e883e | 390 | __func__, message_len, (i + key_rec->enc_key_size)); |
dddfa461 MH |
391 | goto out; |
392 | } | |
393 | if (key_rec->enc_key_size > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
dddfa461 | 394 | rc = -EIO; |
df261c52 | 395 | printk(KERN_ERR "%s: Encrypted key_size [%zd] larger than " |
f66e883e MH |
396 | "the maximum key size [%d]\n", __func__, |
397 | key_rec->enc_key_size, | |
398 | ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES); | |
dddfa461 MH |
399 | goto out; |
400 | } | |
401 | memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size); | |
402 | out: | |
403 | return rc; | |
404 | } | |
405 | ||
9c79f34f MH |
406 | static int |
407 | ecryptfs_find_global_auth_tok_for_sig( | |
408 | struct ecryptfs_global_auth_tok **global_auth_tok, | |
409 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig) | |
410 | { | |
411 | struct ecryptfs_global_auth_tok *walker; | |
412 | int rc = 0; | |
413 | ||
414 | (*global_auth_tok) = NULL; | |
415 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
416 | list_for_each_entry(walker, | |
417 | &mount_crypt_stat->global_auth_tok_list, | |
418 | mount_crypt_stat_list) { | |
419 | if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX) == 0) { | |
38919598 TH |
420 | rc = key_validate(walker->global_auth_tok_key); |
421 | if (!rc) | |
422 | (*global_auth_tok) = walker; | |
9c79f34f MH |
423 | goto out; |
424 | } | |
425 | } | |
426 | rc = -EINVAL; | |
427 | out: | |
428 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
429 | return rc; | |
430 | } | |
431 | ||
432 | /** | |
433 | * ecryptfs_find_auth_tok_for_sig | |
434 | * @auth_tok: Set to the matching auth_tok; NULL if not found | |
435 | * @crypt_stat: inode crypt_stat crypto context | |
436 | * @sig: Sig of auth_tok to find | |
437 | * | |
438 | * For now, this function simply looks at the registered auth_tok's | |
439 | * linked off the mount_crypt_stat, so all the auth_toks that can be | |
440 | * used must be registered at mount time. This function could | |
441 | * potentially try a lot harder to find auth_tok's (e.g., by calling | |
442 | * out to ecryptfsd to dynamically retrieve an auth_tok object) so | |
443 | * that static registration of auth_tok's will no longer be necessary. | |
444 | * | |
445 | * Returns zero on no error; non-zero on error | |
446 | */ | |
447 | static int | |
448 | ecryptfs_find_auth_tok_for_sig( | |
449 | struct ecryptfs_auth_tok **auth_tok, | |
450 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
451 | char *sig) | |
452 | { | |
453 | struct ecryptfs_global_auth_tok *global_auth_tok; | |
454 | int rc = 0; | |
455 | ||
456 | (*auth_tok) = NULL; | |
457 | if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok, | |
458 | mount_crypt_stat, sig)) { | |
459 | struct key *auth_tok_key; | |
460 | ||
461 | rc = ecryptfs_keyring_auth_tok_for_sig(&auth_tok_key, auth_tok, | |
462 | sig); | |
463 | } else | |
464 | (*auth_tok) = global_auth_tok->global_auth_tok; | |
465 | return rc; | |
466 | } | |
467 | ||
468 | /** | |
469 | * write_tag_70_packet can gobble a lot of stack space. We stuff most | |
470 | * of the function's parameters in a kmalloc'd struct to help reduce | |
471 | * eCryptfs' overall stack usage. | |
472 | */ | |
473 | struct ecryptfs_write_tag_70_packet_silly_stack { | |
474 | u8 cipher_code; | |
475 | size_t max_packet_size; | |
476 | size_t packet_size_len; | |
477 | size_t block_aligned_filename_size; | |
478 | size_t block_size; | |
479 | size_t i; | |
480 | size_t j; | |
481 | size_t num_rand_bytes; | |
482 | struct mutex *tfm_mutex; | |
483 | char *block_aligned_filename; | |
484 | struct ecryptfs_auth_tok *auth_tok; | |
485 | struct scatterlist src_sg; | |
486 | struct scatterlist dst_sg; | |
487 | struct blkcipher_desc desc; | |
488 | char iv[ECRYPTFS_MAX_IV_BYTES]; | |
489 | char hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; | |
490 | char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; | |
491 | struct hash_desc hash_desc; | |
492 | struct scatterlist hash_sg; | |
493 | }; | |
494 | ||
495 | /** | |
496 | * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK | |
497 | * @filename: NULL-terminated filename string | |
498 | * | |
499 | * This is the simplest mechanism for achieving filename encryption in | |
500 | * eCryptfs. It encrypts the given filename with the mount-wide | |
501 | * filename encryption key (FNEK) and stores it in a packet to @dest, | |
502 | * which the callee will encode and write directly into the dentry | |
503 | * name. | |
504 | */ | |
505 | int | |
506 | ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, | |
507 | size_t *packet_size, | |
508 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
509 | char *filename, size_t filename_size) | |
510 | { | |
511 | struct ecryptfs_write_tag_70_packet_silly_stack *s; | |
512 | int rc = 0; | |
513 | ||
514 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
515 | if (!s) { | |
516 | printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc " | |
df261c52 | 517 | "[%zd] bytes of kernel memory\n", __func__, sizeof(*s)); |
f137f150 | 518 | rc = -ENOMEM; |
9c79f34f MH |
519 | goto out; |
520 | } | |
521 | s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; | |
522 | (*packet_size) = 0; | |
523 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name( | |
524 | &s->desc.tfm, | |
525 | &s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name); | |
526 | if (unlikely(rc)) { | |
527 | printk(KERN_ERR "Internal error whilst attempting to get " | |
528 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
529 | mount_crypt_stat->global_default_fn_cipher_name, rc); | |
530 | goto out; | |
531 | } | |
532 | mutex_lock(s->tfm_mutex); | |
533 | s->block_size = crypto_blkcipher_blocksize(s->desc.tfm); | |
534 | /* Plus one for the \0 separator between the random prefix | |
535 | * and the plaintext filename */ | |
536 | s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1); | |
537 | s->block_aligned_filename_size = (s->num_rand_bytes + filename_size); | |
538 | if ((s->block_aligned_filename_size % s->block_size) != 0) { | |
539 | s->num_rand_bytes += (s->block_size | |
540 | - (s->block_aligned_filename_size | |
541 | % s->block_size)); | |
542 | s->block_aligned_filename_size = (s->num_rand_bytes | |
543 | + filename_size); | |
544 | } | |
545 | /* Octet 0: Tag 70 identifier | |
546 | * Octets 1-N1: Tag 70 packet size (includes cipher identifier | |
547 | * and block-aligned encrypted filename size) | |
548 | * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) | |
549 | * Octet N2-N3: Cipher identifier (1 octet) | |
550 | * Octets N3-N4: Block-aligned encrypted filename | |
551 | * - Consists of a minimum number of random characters, a \0 | |
552 | * separator, and then the filename */ | |
553 | s->max_packet_size = (1 /* Tag 70 identifier */ | |
554 | + 3 /* Max Tag 70 packet size */ | |
555 | + ECRYPTFS_SIG_SIZE /* FNEK sig */ | |
556 | + 1 /* Cipher identifier */ | |
557 | + s->block_aligned_filename_size); | |
558 | if (dest == NULL) { | |
559 | (*packet_size) = s->max_packet_size; | |
560 | goto out_unlock; | |
561 | } | |
562 | if (s->max_packet_size > (*remaining_bytes)) { | |
a8f12864 MH |
563 | printk(KERN_WARNING "%s: Require [%zd] bytes to write; only " |
564 | "[%zd] available\n", __func__, s->max_packet_size, | |
9c79f34f MH |
565 | (*remaining_bytes)); |
566 | rc = -EINVAL; | |
567 | goto out_unlock; | |
568 | } | |
569 | s->block_aligned_filename = kzalloc(s->block_aligned_filename_size, | |
570 | GFP_KERNEL); | |
571 | if (!s->block_aligned_filename) { | |
572 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " | |
df261c52 | 573 | "kzalloc [%zd] bytes\n", __func__, |
9c79f34f MH |
574 | s->block_aligned_filename_size); |
575 | rc = -ENOMEM; | |
576 | goto out_unlock; | |
577 | } | |
578 | s->i = 0; | |
579 | dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE; | |
580 | rc = ecryptfs_write_packet_length(&dest[s->i], | |
581 | (ECRYPTFS_SIG_SIZE | |
582 | + 1 /* Cipher code */ | |
583 | + s->block_aligned_filename_size), | |
584 | &s->packet_size_len); | |
585 | if (rc) { | |
586 | printk(KERN_ERR "%s: Error generating tag 70 packet " | |
587 | "header; cannot generate packet length; rc = [%d]\n", | |
588 | __func__, rc); | |
589 | goto out_free_unlock; | |
590 | } | |
591 | s->i += s->packet_size_len; | |
592 | ecryptfs_from_hex(&dest[s->i], | |
593 | mount_crypt_stat->global_default_fnek_sig, | |
594 | ECRYPTFS_SIG_SIZE); | |
595 | s->i += ECRYPTFS_SIG_SIZE; | |
596 | s->cipher_code = ecryptfs_code_for_cipher_string( | |
597 | mount_crypt_stat->global_default_fn_cipher_name, | |
598 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
599 | if (s->cipher_code == 0) { | |
600 | printk(KERN_WARNING "%s: Unable to generate code for " | |
a8f12864 | 601 | "cipher [%s] with key bytes [%zd]\n", __func__, |
9c79f34f MH |
602 | mount_crypt_stat->global_default_fn_cipher_name, |
603 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
604 | rc = -EINVAL; | |
605 | goto out_free_unlock; | |
606 | } | |
607 | dest[s->i++] = s->cipher_code; | |
608 | rc = ecryptfs_find_auth_tok_for_sig( | |
609 | &s->auth_tok, mount_crypt_stat, | |
610 | mount_crypt_stat->global_default_fnek_sig); | |
611 | if (rc) { | |
612 | printk(KERN_ERR "%s: Error attempting to find auth tok for " | |
613 | "fnek sig [%s]; rc = [%d]\n", __func__, | |
614 | mount_crypt_stat->global_default_fnek_sig, rc); | |
615 | goto out_free_unlock; | |
616 | } | |
617 | /* TODO: Support other key modules than passphrase for | |
618 | * filename encryption */ | |
df6ad33b TH |
619 | if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) { |
620 | rc = -EOPNOTSUPP; | |
621 | printk(KERN_INFO "%s: Filename encryption only supports " | |
622 | "password tokens\n", __func__); | |
623 | goto out_free_unlock; | |
624 | } | |
9c79f34f MH |
625 | sg_init_one( |
626 | &s->hash_sg, | |
627 | (u8 *)s->auth_tok->token.password.session_key_encryption_key, | |
628 | s->auth_tok->token.password.session_key_encryption_key_bytes); | |
629 | s->hash_desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; | |
630 | s->hash_desc.tfm = crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST, 0, | |
631 | CRYPTO_ALG_ASYNC); | |
632 | if (IS_ERR(s->hash_desc.tfm)) { | |
633 | rc = PTR_ERR(s->hash_desc.tfm); | |
634 | printk(KERN_ERR "%s: Error attempting to " | |
635 | "allocate hash crypto context; rc = [%d]\n", | |
636 | __func__, rc); | |
637 | goto out_free_unlock; | |
638 | } | |
639 | rc = crypto_hash_init(&s->hash_desc); | |
640 | if (rc) { | |
641 | printk(KERN_ERR | |
642 | "%s: Error initializing crypto hash; rc = [%d]\n", | |
643 | __func__, rc); | |
644 | goto out_release_free_unlock; | |
645 | } | |
646 | rc = crypto_hash_update( | |
647 | &s->hash_desc, &s->hash_sg, | |
648 | s->auth_tok->token.password.session_key_encryption_key_bytes); | |
649 | if (rc) { | |
650 | printk(KERN_ERR | |
651 | "%s: Error updating crypto hash; rc = [%d]\n", | |
652 | __func__, rc); | |
653 | goto out_release_free_unlock; | |
654 | } | |
655 | rc = crypto_hash_final(&s->hash_desc, s->hash); | |
656 | if (rc) { | |
657 | printk(KERN_ERR | |
658 | "%s: Error finalizing crypto hash; rc = [%d]\n", | |
659 | __func__, rc); | |
660 | goto out_release_free_unlock; | |
661 | } | |
662 | for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) { | |
663 | s->block_aligned_filename[s->j] = | |
664 | s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)]; | |
665 | if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE) | |
666 | == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) { | |
667 | sg_init_one(&s->hash_sg, (u8 *)s->hash, | |
668 | ECRYPTFS_TAG_70_DIGEST_SIZE); | |
669 | rc = crypto_hash_init(&s->hash_desc); | |
670 | if (rc) { | |
671 | printk(KERN_ERR | |
672 | "%s: Error initializing crypto hash; " | |
673 | "rc = [%d]\n", __func__, rc); | |
674 | goto out_release_free_unlock; | |
675 | } | |
676 | rc = crypto_hash_update(&s->hash_desc, &s->hash_sg, | |
677 | ECRYPTFS_TAG_70_DIGEST_SIZE); | |
678 | if (rc) { | |
679 | printk(KERN_ERR | |
680 | "%s: Error updating crypto hash; " | |
681 | "rc = [%d]\n", __func__, rc); | |
682 | goto out_release_free_unlock; | |
683 | } | |
684 | rc = crypto_hash_final(&s->hash_desc, s->tmp_hash); | |
685 | if (rc) { | |
686 | printk(KERN_ERR | |
687 | "%s: Error finalizing crypto hash; " | |
688 | "rc = [%d]\n", __func__, rc); | |
689 | goto out_release_free_unlock; | |
690 | } | |
691 | memcpy(s->hash, s->tmp_hash, | |
692 | ECRYPTFS_TAG_70_DIGEST_SIZE); | |
693 | } | |
694 | if (s->block_aligned_filename[s->j] == '\0') | |
695 | s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL; | |
696 | } | |
697 | memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename, | |
698 | filename_size); | |
699 | rc = virt_to_scatterlist(s->block_aligned_filename, | |
700 | s->block_aligned_filename_size, &s->src_sg, 1); | |
701 | if (rc != 1) { | |
702 | printk(KERN_ERR "%s: Internal error whilst attempting to " | |
703 | "convert filename memory to scatterlist; " | |
704 | "expected rc = 1; got rc = [%d]. " | |
a8f12864 | 705 | "block_aligned_filename_size = [%zd]\n", __func__, rc, |
9c79f34f MH |
706 | s->block_aligned_filename_size); |
707 | goto out_release_free_unlock; | |
708 | } | |
709 | rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size, | |
710 | &s->dst_sg, 1); | |
711 | if (rc != 1) { | |
712 | printk(KERN_ERR "%s: Internal error whilst attempting to " | |
713 | "convert encrypted filename memory to scatterlist; " | |
714 | "expected rc = 1; got rc = [%d]. " | |
a8f12864 | 715 | "block_aligned_filename_size = [%zd]\n", __func__, rc, |
9c79f34f MH |
716 | s->block_aligned_filename_size); |
717 | goto out_release_free_unlock; | |
718 | } | |
719 | /* The characters in the first block effectively do the job | |
720 | * of the IV here, so we just use 0's for the IV. Note the | |
721 | * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES | |
722 | * >= ECRYPTFS_MAX_IV_BYTES. */ | |
723 | memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES); | |
724 | s->desc.info = s->iv; | |
725 | rc = crypto_blkcipher_setkey( | |
726 | s->desc.tfm, | |
727 | s->auth_tok->token.password.session_key_encryption_key, | |
728 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
729 | if (rc < 0) { | |
730 | printk(KERN_ERR "%s: Error setting key for crypto context; " | |
731 | "rc = [%d]. s->auth_tok->token.password.session_key_" | |
732 | "encryption_key = [0x%p]; mount_crypt_stat->" | |
df261c52 | 733 | "global_default_fn_cipher_key_bytes = [%zd]\n", __func__, |
9c79f34f MH |
734 | rc, |
735 | s->auth_tok->token.password.session_key_encryption_key, | |
736 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
737 | goto out_release_free_unlock; | |
738 | } | |
739 | rc = crypto_blkcipher_encrypt_iv(&s->desc, &s->dst_sg, &s->src_sg, | |
740 | s->block_aligned_filename_size); | |
741 | if (rc) { | |
742 | printk(KERN_ERR "%s: Error attempting to encrypt filename; " | |
743 | "rc = [%d]\n", __func__, rc); | |
744 | goto out_release_free_unlock; | |
745 | } | |
746 | s->i += s->block_aligned_filename_size; | |
747 | (*packet_size) = s->i; | |
748 | (*remaining_bytes) -= (*packet_size); | |
749 | out_release_free_unlock: | |
750 | crypto_free_hash(s->hash_desc.tfm); | |
751 | out_free_unlock: | |
00fcf2cb | 752 | kzfree(s->block_aligned_filename); |
9c79f34f MH |
753 | out_unlock: |
754 | mutex_unlock(s->tfm_mutex); | |
755 | out: | |
756 | kfree(s); | |
757 | return rc; | |
758 | } | |
759 | ||
760 | struct ecryptfs_parse_tag_70_packet_silly_stack { | |
761 | u8 cipher_code; | |
762 | size_t max_packet_size; | |
763 | size_t packet_size_len; | |
764 | size_t parsed_tag_70_packet_size; | |
765 | size_t block_aligned_filename_size; | |
766 | size_t block_size; | |
767 | size_t i; | |
768 | struct mutex *tfm_mutex; | |
769 | char *decrypted_filename; | |
770 | struct ecryptfs_auth_tok *auth_tok; | |
771 | struct scatterlist src_sg; | |
772 | struct scatterlist dst_sg; | |
773 | struct blkcipher_desc desc; | |
774 | char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1]; | |
775 | char iv[ECRYPTFS_MAX_IV_BYTES]; | |
776 | char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE]; | |
777 | }; | |
778 | ||
779 | /** | |
780 | * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet | |
781 | * @filename: This function kmalloc's the memory for the filename | |
7d8bc2be MH |
782 | * @filename_size: This function sets this to the amount of memory |
783 | * kmalloc'd for the filename | |
784 | * @packet_size: This function sets this to the the number of octets | |
785 | * in the packet parsed | |
786 | * @mount_crypt_stat: The mount-wide cryptographic context | |
787 | * @data: The memory location containing the start of the tag 70 | |
788 | * packet | |
789 | * @max_packet_size: The maximum legal size of the packet to be parsed | |
790 | * from @data | |
791 | * | |
792 | * Returns zero on success; non-zero otherwise | |
9c79f34f MH |
793 | */ |
794 | int | |
795 | ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, | |
796 | size_t *packet_size, | |
797 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
798 | char *data, size_t max_packet_size) | |
799 | { | |
800 | struct ecryptfs_parse_tag_70_packet_silly_stack *s; | |
801 | int rc = 0; | |
802 | ||
803 | (*packet_size) = 0; | |
804 | (*filename_size) = 0; | |
805 | (*filename) = NULL; | |
806 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
807 | if (!s) { | |
808 | printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc " | |
a8f12864 | 809 | "[%zd] bytes of kernel memory\n", __func__, sizeof(*s)); |
f137f150 | 810 | rc = -ENOMEM; |
9c79f34f MH |
811 | goto out; |
812 | } | |
813 | s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; | |
814 | if (max_packet_size < (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)) { | |
df261c52 | 815 | printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be " |
9c79f34f MH |
816 | "at least [%d]\n", __func__, max_packet_size, |
817 | (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)); | |
818 | rc = -EINVAL; | |
819 | goto out; | |
820 | } | |
821 | /* Octet 0: Tag 70 identifier | |
822 | * Octets 1-N1: Tag 70 packet size (includes cipher identifier | |
823 | * and block-aligned encrypted filename size) | |
824 | * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) | |
825 | * Octet N2-N3: Cipher identifier (1 octet) | |
826 | * Octets N3-N4: Block-aligned encrypted filename | |
827 | * - Consists of a minimum number of random numbers, a \0 | |
828 | * separator, and then the filename */ | |
829 | if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) { | |
830 | printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be " | |
831 | "tag [0x%.2x]\n", __func__, | |
832 | data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE); | |
833 | rc = -EINVAL; | |
834 | goto out; | |
835 | } | |
836 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], | |
837 | &s->parsed_tag_70_packet_size, | |
838 | &s->packet_size_len); | |
839 | if (rc) { | |
840 | printk(KERN_WARNING "%s: Error parsing packet length; " | |
841 | "rc = [%d]\n", __func__, rc); | |
842 | goto out; | |
843 | } | |
844 | s->block_aligned_filename_size = (s->parsed_tag_70_packet_size | |
845 | - ECRYPTFS_SIG_SIZE - 1); | |
846 | if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size) | |
847 | > max_packet_size) { | |
a8f12864 MH |
848 | printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet " |
849 | "size is [%zd]\n", __func__, max_packet_size, | |
9c79f34f MH |
850 | (1 + s->packet_size_len + 1 |
851 | + s->block_aligned_filename_size)); | |
852 | rc = -EINVAL; | |
853 | goto out; | |
854 | } | |
855 | (*packet_size) += s->packet_size_len; | |
856 | ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)], | |
857 | ECRYPTFS_SIG_SIZE); | |
858 | s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0'; | |
859 | (*packet_size) += ECRYPTFS_SIG_SIZE; | |
860 | s->cipher_code = data[(*packet_size)++]; | |
861 | rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code); | |
862 | if (rc) { | |
863 | printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n", | |
864 | __func__, s->cipher_code); | |
865 | goto out; | |
866 | } | |
867 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm, | |
868 | &s->tfm_mutex, | |
869 | s->cipher_string); | |
870 | if (unlikely(rc)) { | |
871 | printk(KERN_ERR "Internal error whilst attempting to get " | |
872 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
873 | s->cipher_string, rc); | |
874 | goto out; | |
875 | } | |
876 | mutex_lock(s->tfm_mutex); | |
877 | rc = virt_to_scatterlist(&data[(*packet_size)], | |
878 | s->block_aligned_filename_size, &s->src_sg, 1); | |
879 | if (rc != 1) { | |
880 | printk(KERN_ERR "%s: Internal error whilst attempting to " | |
881 | "convert encrypted filename memory to scatterlist; " | |
882 | "expected rc = 1; got rc = [%d]. " | |
a8f12864 | 883 | "block_aligned_filename_size = [%zd]\n", __func__, rc, |
9c79f34f MH |
884 | s->block_aligned_filename_size); |
885 | goto out_unlock; | |
886 | } | |
887 | (*packet_size) += s->block_aligned_filename_size; | |
888 | s->decrypted_filename = kmalloc(s->block_aligned_filename_size, | |
889 | GFP_KERNEL); | |
890 | if (!s->decrypted_filename) { | |
891 | printk(KERN_ERR "%s: Out of memory whilst attempting to " | |
a8f12864 | 892 | "kmalloc [%zd] bytes\n", __func__, |
9c79f34f MH |
893 | s->block_aligned_filename_size); |
894 | rc = -ENOMEM; | |
895 | goto out_unlock; | |
896 | } | |
897 | rc = virt_to_scatterlist(s->decrypted_filename, | |
898 | s->block_aligned_filename_size, &s->dst_sg, 1); | |
899 | if (rc != 1) { | |
900 | printk(KERN_ERR "%s: Internal error whilst attempting to " | |
901 | "convert decrypted filename memory to scatterlist; " | |
902 | "expected rc = 1; got rc = [%d]. " | |
a8f12864 | 903 | "block_aligned_filename_size = [%zd]\n", __func__, rc, |
9c79f34f MH |
904 | s->block_aligned_filename_size); |
905 | goto out_free_unlock; | |
906 | } | |
907 | /* The characters in the first block effectively do the job of | |
908 | * the IV here, so we just use 0's for the IV. Note the | |
909 | * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES | |
910 | * >= ECRYPTFS_MAX_IV_BYTES. */ | |
911 | memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES); | |
912 | s->desc.info = s->iv; | |
913 | rc = ecryptfs_find_auth_tok_for_sig(&s->auth_tok, mount_crypt_stat, | |
914 | s->fnek_sig_hex); | |
915 | if (rc) { | |
916 | printk(KERN_ERR "%s: Error attempting to find auth tok for " | |
917 | "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex, | |
918 | rc); | |
919 | goto out_free_unlock; | |
920 | } | |
921 | /* TODO: Support other key modules than passphrase for | |
922 | * filename encryption */ | |
df6ad33b TH |
923 | if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) { |
924 | rc = -EOPNOTSUPP; | |
925 | printk(KERN_INFO "%s: Filename encryption only supports " | |
926 | "password tokens\n", __func__); | |
927 | goto out_free_unlock; | |
928 | } | |
9c79f34f MH |
929 | rc = crypto_blkcipher_setkey( |
930 | s->desc.tfm, | |
931 | s->auth_tok->token.password.session_key_encryption_key, | |
932 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
933 | if (rc < 0) { | |
934 | printk(KERN_ERR "%s: Error setting key for crypto context; " | |
935 | "rc = [%d]. s->auth_tok->token.password.session_key_" | |
936 | "encryption_key = [0x%p]; mount_crypt_stat->" | |
df261c52 | 937 | "global_default_fn_cipher_key_bytes = [%zd]\n", __func__, |
9c79f34f MH |
938 | rc, |
939 | s->auth_tok->token.password.session_key_encryption_key, | |
940 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
941 | goto out_free_unlock; | |
942 | } | |
943 | rc = crypto_blkcipher_decrypt_iv(&s->desc, &s->dst_sg, &s->src_sg, | |
944 | s->block_aligned_filename_size); | |
945 | if (rc) { | |
946 | printk(KERN_ERR "%s: Error attempting to decrypt filename; " | |
947 | "rc = [%d]\n", __func__, rc); | |
948 | goto out_free_unlock; | |
949 | } | |
950 | s->i = 0; | |
951 | while (s->decrypted_filename[s->i] != '\0' | |
952 | && s->i < s->block_aligned_filename_size) | |
953 | s->i++; | |
954 | if (s->i == s->block_aligned_filename_size) { | |
955 | printk(KERN_WARNING "%s: Invalid tag 70 packet; could not " | |
956 | "find valid separator between random characters and " | |
957 | "the filename\n", __func__); | |
958 | rc = -EINVAL; | |
959 | goto out_free_unlock; | |
960 | } | |
961 | s->i++; | |
962 | (*filename_size) = (s->block_aligned_filename_size - s->i); | |
963 | if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) { | |
df261c52 | 964 | printk(KERN_WARNING "%s: Filename size is [%zd], which is " |
9c79f34f MH |
965 | "invalid\n", __func__, (*filename_size)); |
966 | rc = -EINVAL; | |
967 | goto out_free_unlock; | |
968 | } | |
969 | (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL); | |
970 | if (!(*filename)) { | |
971 | printk(KERN_ERR "%s: Out of memory whilst attempting to " | |
a8f12864 | 972 | "kmalloc [%zd] bytes\n", __func__, |
9c79f34f MH |
973 | ((*filename_size) + 1)); |
974 | rc = -ENOMEM; | |
975 | goto out_free_unlock; | |
976 | } | |
977 | memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size)); | |
978 | (*filename)[(*filename_size)] = '\0'; | |
979 | out_free_unlock: | |
980 | kfree(s->decrypted_filename); | |
981 | out_unlock: | |
982 | mutex_unlock(s->tfm_mutex); | |
983 | out: | |
984 | if (rc) { | |
985 | (*packet_size) = 0; | |
986 | (*filename_size) = 0; | |
987 | (*filename) = NULL; | |
988 | } | |
989 | kfree(s); | |
990 | return rc; | |
991 | } | |
992 | ||
cd9d67df MH |
993 | static int |
994 | ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok) | |
995 | { | |
996 | int rc = 0; | |
997 | ||
998 | (*sig) = NULL; | |
999 | switch (auth_tok->token_type) { | |
1000 | case ECRYPTFS_PASSWORD: | |
1001 | (*sig) = auth_tok->token.password.signature; | |
1002 | break; | |
1003 | case ECRYPTFS_PRIVATE_KEY: | |
1004 | (*sig) = auth_tok->token.private_key.signature; | |
1005 | break; | |
1006 | default: | |
1007 | printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n", | |
1008 | auth_tok->token_type); | |
1009 | rc = -EINVAL; | |
1010 | } | |
1011 | return rc; | |
1012 | } | |
1013 | ||
dddfa461 | 1014 | /** |
22e78faf MH |
1015 | * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok. |
1016 | * @auth_tok: The key authentication token used to decrypt the session key | |
1017 | * @crypt_stat: The cryptographic context | |
dddfa461 | 1018 | * |
22e78faf | 1019 | * Returns zero on success; non-zero error otherwise. |
dddfa461 | 1020 | */ |
f4aad16a MH |
1021 | static int |
1022 | decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, | |
1023 | struct ecryptfs_crypt_stat *crypt_stat) | |
dddfa461 | 1024 | { |
19e66a67 | 1025 | u8 cipher_code = 0; |
dddfa461 MH |
1026 | struct ecryptfs_msg_ctx *msg_ctx; |
1027 | struct ecryptfs_message *msg = NULL; | |
f4aad16a | 1028 | char *auth_tok_sig; |
624ae528 TH |
1029 | char *payload; |
1030 | size_t payload_len; | |
dddfa461 MH |
1031 | int rc; |
1032 | ||
5dda6992 MH |
1033 | rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok); |
1034 | if (rc) { | |
f4aad16a MH |
1035 | printk(KERN_ERR "Unrecognized auth tok type: [%d]\n", |
1036 | auth_tok->token_type); | |
1037 | goto out; | |
1038 | } | |
1039 | rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key), | |
624ae528 | 1040 | &payload, &payload_len); |
dddfa461 | 1041 | if (rc) { |
f66e883e | 1042 | ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n"); |
dddfa461 MH |
1043 | goto out; |
1044 | } | |
624ae528 | 1045 | rc = ecryptfs_send_message(payload, payload_len, &msg_ctx); |
dddfa461 | 1046 | if (rc) { |
624ae528 TH |
1047 | ecryptfs_printk(KERN_ERR, "Error sending message to " |
1048 | "ecryptfsd\n"); | |
dddfa461 MH |
1049 | goto out; |
1050 | } | |
1051 | rc = ecryptfs_wait_for_response(msg_ctx, &msg); | |
1052 | if (rc) { | |
1053 | ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet " | |
1054 | "from the user space daemon\n"); | |
1055 | rc = -EIO; | |
1056 | goto out; | |
1057 | } | |
1058 | rc = parse_tag_65_packet(&(auth_tok->session_key), | |
1059 | &cipher_code, msg); | |
1060 | if (rc) { | |
1061 | printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n", | |
1062 | rc); | |
1063 | goto out; | |
1064 | } | |
1065 | auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1066 | memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, | |
1067 | auth_tok->session_key.decrypted_key_size); | |
1068 | crypt_stat->key_size = auth_tok->session_key.decrypted_key_size; | |
1069 | rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code); | |
1070 | if (rc) { | |
1071 | ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n", | |
1072 | cipher_code) | |
1073 | goto out; | |
1074 | } | |
1075 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; | |
1076 | if (ecryptfs_verbosity > 0) { | |
1077 | ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n"); | |
1078 | ecryptfs_dump_hex(crypt_stat->key, | |
1079 | crypt_stat->key_size); | |
1080 | } | |
1081 | out: | |
1082 | if (msg) | |
1083 | kfree(msg); | |
1084 | return rc; | |
1085 | } | |
1086 | ||
1087 | static void wipe_auth_tok_list(struct list_head *auth_tok_list_head) | |
1088 | { | |
dddfa461 | 1089 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
e0869cc1 | 1090 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
dddfa461 | 1091 | |
e0869cc1 MH |
1092 | list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp, |
1093 | auth_tok_list_head, list) { | |
1094 | list_del(&auth_tok_list_item->list); | |
dddfa461 MH |
1095 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, |
1096 | auth_tok_list_item); | |
1097 | } | |
dddfa461 MH |
1098 | } |
1099 | ||
1100 | struct kmem_cache *ecryptfs_auth_tok_list_item_cache; | |
1101 | ||
dddfa461 MH |
1102 | /** |
1103 | * parse_tag_1_packet | |
22e78faf | 1104 | * @crypt_stat: The cryptographic context to modify based on packet contents |
dddfa461 MH |
1105 | * @data: The raw bytes of the packet. |
1106 | * @auth_tok_list: eCryptfs parses packets into authentication tokens; | |
22e78faf MH |
1107 | * a new authentication token will be placed at the |
1108 | * end of this list for this packet. | |
dddfa461 MH |
1109 | * @new_auth_tok: Pointer to a pointer to memory that this function |
1110 | * allocates; sets the memory address of the pointer to | |
1111 | * NULL on error. This object is added to the | |
1112 | * auth_tok_list. | |
1113 | * @packet_size: This function writes the size of the parsed packet | |
1114 | * into this memory location; zero on error. | |
22e78faf | 1115 | * @max_packet_size: The maximum allowable packet size |
dddfa461 MH |
1116 | * |
1117 | * Returns zero on success; non-zero on error. | |
1118 | */ | |
1119 | static int | |
1120 | parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat, | |
1121 | unsigned char *data, struct list_head *auth_tok_list, | |
1122 | struct ecryptfs_auth_tok **new_auth_tok, | |
1123 | size_t *packet_size, size_t max_packet_size) | |
1124 | { | |
1125 | size_t body_size; | |
1126 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; | |
1127 | size_t length_size; | |
1128 | int rc = 0; | |
1129 | ||
1130 | (*packet_size) = 0; | |
1131 | (*new_auth_tok) = NULL; | |
13218179 MH |
1132 | /** |
1133 | * This format is inspired by OpenPGP; see RFC 2440 | |
1134 | * packet tag 1 | |
1135 | * | |
1136 | * Tag 1 identifier (1 byte) | |
1137 | * Max Tag 1 packet size (max 3 bytes) | |
1138 | * Version (1 byte) | |
1139 | * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE) | |
1140 | * Cipher identifier (1 byte) | |
1141 | * Encrypted key size (arbitrary) | |
1142 | * | |
1143 | * 12 bytes minimum packet size | |
dddfa461 | 1144 | */ |
13218179 MH |
1145 | if (unlikely(max_packet_size < 12)) { |
1146 | printk(KERN_ERR "Invalid max packet size; must be >=12\n"); | |
dddfa461 MH |
1147 | rc = -EINVAL; |
1148 | goto out; | |
1149 | } | |
dddfa461 | 1150 | if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) { |
13218179 MH |
1151 | printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n", |
1152 | ECRYPTFS_TAG_1_PACKET_TYPE); | |
dddfa461 MH |
1153 | rc = -EINVAL; |
1154 | goto out; | |
1155 | } | |
1156 | /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or | |
1157 | * at end of function upon failure */ | |
1158 | auth_tok_list_item = | |
13218179 MH |
1159 | kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, |
1160 | GFP_KERNEL); | |
dddfa461 | 1161 | if (!auth_tok_list_item) { |
13218179 | 1162 | printk(KERN_ERR "Unable to allocate memory\n"); |
dddfa461 MH |
1163 | rc = -ENOMEM; |
1164 | goto out; | |
1165 | } | |
dddfa461 | 1166 | (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
f66e883e MH |
1167 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1168 | &length_size); | |
5dda6992 | 1169 | if (rc) { |
13218179 MH |
1170 | printk(KERN_WARNING "Error parsing packet length; " |
1171 | "rc = [%d]\n", rc); | |
dddfa461 MH |
1172 | goto out_free; |
1173 | } | |
13218179 | 1174 | if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) { |
81acbcd6 | 1175 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
dddfa461 MH |
1176 | rc = -EINVAL; |
1177 | goto out_free; | |
1178 | } | |
1179 | (*packet_size) += length_size; | |
1180 | if (unlikely((*packet_size) + body_size > max_packet_size)) { | |
13218179 | 1181 | printk(KERN_WARNING "Packet size exceeds max\n"); |
dddfa461 MH |
1182 | rc = -EINVAL; |
1183 | goto out_free; | |
1184 | } | |
dddfa461 | 1185 | if (unlikely(data[(*packet_size)++] != 0x03)) { |
13218179 MH |
1186 | printk(KERN_WARNING "Unknown version number [%d]\n", |
1187 | data[(*packet_size) - 1]); | |
dddfa461 MH |
1188 | rc = -EINVAL; |
1189 | goto out_free; | |
1190 | } | |
dddfa461 MH |
1191 | ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature, |
1192 | &data[(*packet_size)], ECRYPTFS_SIG_SIZE); | |
1193 | *packet_size += ECRYPTFS_SIG_SIZE; | |
1194 | /* This byte is skipped because the kernel does not need to | |
1195 | * know which public key encryption algorithm was used */ | |
1196 | (*packet_size)++; | |
1197 | (*new_auth_tok)->session_key.encrypted_key_size = | |
13218179 | 1198 | body_size - (ECRYPTFS_SIG_SIZE + 2); |
dddfa461 MH |
1199 | if ((*new_auth_tok)->session_key.encrypted_key_size |
1200 | > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
13218179 MH |
1201 | printk(KERN_WARNING "Tag 1 packet contains key larger " |
1202 | "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES"); | |
dddfa461 MH |
1203 | rc = -EINVAL; |
1204 | goto out; | |
1205 | } | |
dddfa461 | 1206 | memcpy((*new_auth_tok)->session_key.encrypted_key, |
13218179 | 1207 | &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2))); |
dddfa461 MH |
1208 | (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size; |
1209 | (*new_auth_tok)->session_key.flags &= | |
1210 | ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1211 | (*new_auth_tok)->session_key.flags |= | |
1212 | ECRYPTFS_CONTAINS_ENCRYPTED_KEY; | |
1213 | (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY; | |
13218179 | 1214 | (*new_auth_tok)->flags = 0; |
e2bd99ec MH |
1215 | (*new_auth_tok)->session_key.flags &= |
1216 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT); | |
1217 | (*new_auth_tok)->session_key.flags &= | |
1218 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT); | |
dddfa461 MH |
1219 | list_add(&auth_tok_list_item->list, auth_tok_list); |
1220 | goto out; | |
1221 | out_free: | |
1222 | (*new_auth_tok) = NULL; | |
1223 | memset(auth_tok_list_item, 0, | |
1224 | sizeof(struct ecryptfs_auth_tok_list_item)); | |
1225 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, | |
1226 | auth_tok_list_item); | |
1227 | out: | |
1228 | if (rc) | |
1229 | (*packet_size) = 0; | |
1230 | return rc; | |
1231 | } | |
1232 | ||
237fead6 MH |
1233 | /** |
1234 | * parse_tag_3_packet | |
1235 | * @crypt_stat: The cryptographic context to modify based on packet | |
1236 | * contents. | |
1237 | * @data: The raw bytes of the packet. | |
1238 | * @auth_tok_list: eCryptfs parses packets into authentication tokens; | |
1239 | * a new authentication token will be placed at the end | |
1240 | * of this list for this packet. | |
1241 | * @new_auth_tok: Pointer to a pointer to memory that this function | |
1242 | * allocates; sets the memory address of the pointer to | |
1243 | * NULL on error. This object is added to the | |
1244 | * auth_tok_list. | |
1245 | * @packet_size: This function writes the size of the parsed packet | |
1246 | * into this memory location; zero on error. | |
1247 | * @max_packet_size: maximum number of bytes to parse | |
1248 | * | |
1249 | * Returns zero on success; non-zero on error. | |
1250 | */ | |
1251 | static int | |
1252 | parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat, | |
1253 | unsigned char *data, struct list_head *auth_tok_list, | |
1254 | struct ecryptfs_auth_tok **new_auth_tok, | |
1255 | size_t *packet_size, size_t max_packet_size) | |
1256 | { | |
237fead6 MH |
1257 | size_t body_size; |
1258 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; | |
1259 | size_t length_size; | |
dddfa461 | 1260 | int rc = 0; |
237fead6 MH |
1261 | |
1262 | (*packet_size) = 0; | |
1263 | (*new_auth_tok) = NULL; | |
c59becfc MH |
1264 | /** |
1265 | *This format is inspired by OpenPGP; see RFC 2440 | |
1266 | * packet tag 3 | |
1267 | * | |
1268 | * Tag 3 identifier (1 byte) | |
1269 | * Max Tag 3 packet size (max 3 bytes) | |
1270 | * Version (1 byte) | |
1271 | * Cipher code (1 byte) | |
1272 | * S2K specifier (1 byte) | |
1273 | * Hash identifier (1 byte) | |
1274 | * Salt (ECRYPTFS_SALT_SIZE) | |
1275 | * Hash iterations (1 byte) | |
1276 | * Encrypted key (arbitrary) | |
1277 | * | |
1278 | * (ECRYPTFS_SALT_SIZE + 7) minimum packet size | |
237fead6 | 1279 | */ |
c59becfc MH |
1280 | if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) { |
1281 | printk(KERN_ERR "Max packet size too large\n"); | |
237fead6 MH |
1282 | rc = -EINVAL; |
1283 | goto out; | |
1284 | } | |
237fead6 | 1285 | if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) { |
c59becfc MH |
1286 | printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n", |
1287 | ECRYPTFS_TAG_3_PACKET_TYPE); | |
237fead6 MH |
1288 | rc = -EINVAL; |
1289 | goto out; | |
1290 | } | |
1291 | /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or | |
1292 | * at end of function upon failure */ | |
1293 | auth_tok_list_item = | |
c3762229 | 1294 | kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL); |
237fead6 | 1295 | if (!auth_tok_list_item) { |
c59becfc | 1296 | printk(KERN_ERR "Unable to allocate memory\n"); |
237fead6 MH |
1297 | rc = -ENOMEM; |
1298 | goto out; | |
1299 | } | |
237fead6 | 1300 | (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
f66e883e MH |
1301 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1302 | &length_size); | |
5dda6992 | 1303 | if (rc) { |
c59becfc MH |
1304 | printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n", |
1305 | rc); | |
237fead6 MH |
1306 | goto out_free; |
1307 | } | |
c59becfc | 1308 | if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) { |
81acbcd6 | 1309 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
237fead6 MH |
1310 | rc = -EINVAL; |
1311 | goto out_free; | |
1312 | } | |
1313 | (*packet_size) += length_size; | |
237fead6 | 1314 | if (unlikely((*packet_size) + body_size > max_packet_size)) { |
c59becfc | 1315 | printk(KERN_ERR "Packet size exceeds max\n"); |
237fead6 MH |
1316 | rc = -EINVAL; |
1317 | goto out_free; | |
1318 | } | |
237fead6 | 1319 | (*new_auth_tok)->session_key.encrypted_key_size = |
c59becfc | 1320 | (body_size - (ECRYPTFS_SALT_SIZE + 5)); |
f151cd2c RCV |
1321 | if ((*new_auth_tok)->session_key.encrypted_key_size |
1322 | > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
1323 | printk(KERN_WARNING "Tag 3 packet contains key larger " | |
1324 | "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n"); | |
1325 | rc = -EINVAL; | |
1326 | goto out_free; | |
1327 | } | |
237fead6 | 1328 | if (unlikely(data[(*packet_size)++] != 0x04)) { |
c59becfc MH |
1329 | printk(KERN_WARNING "Unknown version number [%d]\n", |
1330 | data[(*packet_size) - 1]); | |
237fead6 MH |
1331 | rc = -EINVAL; |
1332 | goto out_free; | |
1333 | } | |
b0105eae TH |
1334 | rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, |
1335 | (u16)data[(*packet_size)]); | |
1336 | if (rc) | |
1337 | goto out_free; | |
237fead6 MH |
1338 | /* A little extra work to differentiate among the AES key |
1339 | * sizes; see RFC2440 */ | |
1340 | switch(data[(*packet_size)++]) { | |
1341 | case RFC2440_CIPHER_AES_192: | |
1342 | crypt_stat->key_size = 24; | |
1343 | break; | |
1344 | default: | |
1345 | crypt_stat->key_size = | |
1346 | (*new_auth_tok)->session_key.encrypted_key_size; | |
1347 | } | |
b0105eae TH |
1348 | rc = ecryptfs_init_crypt_ctx(crypt_stat); |
1349 | if (rc) | |
1350 | goto out_free; | |
237fead6 | 1351 | if (unlikely(data[(*packet_size)++] != 0x03)) { |
c59becfc | 1352 | printk(KERN_WARNING "Only S2K ID 3 is currently supported\n"); |
237fead6 MH |
1353 | rc = -ENOSYS; |
1354 | goto out_free; | |
1355 | } | |
237fead6 | 1356 | /* TODO: finish the hash mapping */ |
237fead6 MH |
1357 | switch (data[(*packet_size)++]) { |
1358 | case 0x01: /* See RFC2440 for these numbers and their mappings */ | |
1359 | /* Choose MD5 */ | |
237fead6 MH |
1360 | memcpy((*new_auth_tok)->token.password.salt, |
1361 | &data[(*packet_size)], ECRYPTFS_SALT_SIZE); | |
1362 | (*packet_size) += ECRYPTFS_SALT_SIZE; | |
237fead6 | 1363 | /* This conversion was taken straight from RFC2440 */ |
237fead6 MH |
1364 | (*new_auth_tok)->token.password.hash_iterations = |
1365 | ((u32) 16 + (data[(*packet_size)] & 15)) | |
1366 | << ((data[(*packet_size)] >> 4) + 6); | |
1367 | (*packet_size)++; | |
c59becfc MH |
1368 | /* Friendly reminder: |
1369 | * (*new_auth_tok)->session_key.encrypted_key_size = | |
1370 | * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */ | |
237fead6 MH |
1371 | memcpy((*new_auth_tok)->session_key.encrypted_key, |
1372 | &data[(*packet_size)], | |
1373 | (*new_auth_tok)->session_key.encrypted_key_size); | |
1374 | (*packet_size) += | |
1375 | (*new_auth_tok)->session_key.encrypted_key_size; | |
1376 | (*new_auth_tok)->session_key.flags &= | |
1377 | ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1378 | (*new_auth_tok)->session_key.flags |= | |
1379 | ECRYPTFS_CONTAINS_ENCRYPTED_KEY; | |
c59becfc | 1380 | (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */ |
237fead6 MH |
1381 | break; |
1382 | default: | |
1383 | ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: " | |
1384 | "[%d]\n", data[(*packet_size) - 1]); | |
1385 | rc = -ENOSYS; | |
1386 | goto out_free; | |
1387 | } | |
1388 | (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD; | |
1389 | /* TODO: Parametarize; we might actually want userspace to | |
1390 | * decrypt the session key. */ | |
e2bd99ec MH |
1391 | (*new_auth_tok)->session_key.flags &= |
1392 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT); | |
1393 | (*new_auth_tok)->session_key.flags &= | |
1394 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT); | |
237fead6 MH |
1395 | list_add(&auth_tok_list_item->list, auth_tok_list); |
1396 | goto out; | |
1397 | out_free: | |
1398 | (*new_auth_tok) = NULL; | |
1399 | memset(auth_tok_list_item, 0, | |
1400 | sizeof(struct ecryptfs_auth_tok_list_item)); | |
1401 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, | |
1402 | auth_tok_list_item); | |
1403 | out: | |
1404 | if (rc) | |
1405 | (*packet_size) = 0; | |
1406 | return rc; | |
1407 | } | |
1408 | ||
1409 | /** | |
1410 | * parse_tag_11_packet | |
1411 | * @data: The raw bytes of the packet | |
1412 | * @contents: This function writes the data contents of the literal | |
1413 | * packet into this memory location | |
1414 | * @max_contents_bytes: The maximum number of bytes that this function | |
1415 | * is allowed to write into contents | |
1416 | * @tag_11_contents_size: This function writes the size of the parsed | |
1417 | * contents into this memory location; zero on | |
1418 | * error | |
1419 | * @packet_size: This function writes the size of the parsed packet | |
1420 | * into this memory location; zero on error | |
1421 | * @max_packet_size: maximum number of bytes to parse | |
1422 | * | |
1423 | * Returns zero on success; non-zero on error. | |
1424 | */ | |
1425 | static int | |
1426 | parse_tag_11_packet(unsigned char *data, unsigned char *contents, | |
1427 | size_t max_contents_bytes, size_t *tag_11_contents_size, | |
1428 | size_t *packet_size, size_t max_packet_size) | |
1429 | { | |
237fead6 MH |
1430 | size_t body_size; |
1431 | size_t length_size; | |
dddfa461 | 1432 | int rc = 0; |
237fead6 MH |
1433 | |
1434 | (*packet_size) = 0; | |
1435 | (*tag_11_contents_size) = 0; | |
f648104a MH |
1436 | /* This format is inspired by OpenPGP; see RFC 2440 |
1437 | * packet tag 11 | |
1438 | * | |
1439 | * Tag 11 identifier (1 byte) | |
1440 | * Max Tag 11 packet size (max 3 bytes) | |
1441 | * Binary format specifier (1 byte) | |
1442 | * Filename length (1 byte) | |
1443 | * Filename ("_CONSOLE") (8 bytes) | |
1444 | * Modification date (4 bytes) | |
1445 | * Literal data (arbitrary) | |
1446 | * | |
1447 | * We need at least 16 bytes of data for the packet to even be | |
1448 | * valid. | |
237fead6 | 1449 | */ |
f648104a MH |
1450 | if (max_packet_size < 16) { |
1451 | printk(KERN_ERR "Maximum packet size too small\n"); | |
237fead6 MH |
1452 | rc = -EINVAL; |
1453 | goto out; | |
1454 | } | |
237fead6 | 1455 | if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) { |
f648104a | 1456 | printk(KERN_WARNING "Invalid tag 11 packet format\n"); |
237fead6 MH |
1457 | rc = -EINVAL; |
1458 | goto out; | |
1459 | } | |
f66e883e MH |
1460 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1461 | &length_size); | |
5dda6992 | 1462 | if (rc) { |
f648104a | 1463 | printk(KERN_WARNING "Invalid tag 11 packet format\n"); |
237fead6 MH |
1464 | goto out; |
1465 | } | |
f648104a | 1466 | if (body_size < 14) { |
81acbcd6 | 1467 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
237fead6 MH |
1468 | rc = -EINVAL; |
1469 | goto out; | |
1470 | } | |
f648104a MH |
1471 | (*packet_size) += length_size; |
1472 | (*tag_11_contents_size) = (body_size - 14); | |
237fead6 | 1473 | if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) { |
f648104a | 1474 | printk(KERN_ERR "Packet size exceeds max\n"); |
237fead6 MH |
1475 | rc = -EINVAL; |
1476 | goto out; | |
1477 | } | |
6352a293 TH |
1478 | if (unlikely((*tag_11_contents_size) > max_contents_bytes)) { |
1479 | printk(KERN_ERR "Literal data section in tag 11 packet exceeds " | |
1480 | "expected size\n"); | |
1481 | rc = -EINVAL; | |
1482 | goto out; | |
1483 | } | |
237fead6 | 1484 | if (data[(*packet_size)++] != 0x62) { |
f648104a | 1485 | printk(KERN_WARNING "Unrecognizable packet\n"); |
237fead6 MH |
1486 | rc = -EINVAL; |
1487 | goto out; | |
1488 | } | |
237fead6 | 1489 | if (data[(*packet_size)++] != 0x08) { |
f648104a | 1490 | printk(KERN_WARNING "Unrecognizable packet\n"); |
237fead6 MH |
1491 | rc = -EINVAL; |
1492 | goto out; | |
1493 | } | |
f648104a | 1494 | (*packet_size) += 12; /* Ignore filename and modification date */ |
237fead6 MH |
1495 | memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size)); |
1496 | (*packet_size) += (*tag_11_contents_size); | |
237fead6 MH |
1497 | out: |
1498 | if (rc) { | |
1499 | (*packet_size) = 0; | |
1500 | (*tag_11_contents_size) = 0; | |
1501 | } | |
1502 | return rc; | |
1503 | } | |
1504 | ||
1505 | /** | |
f4aad16a MH |
1506 | * ecryptfs_verify_version |
1507 | * @version: The version number to confirm | |
1508 | * | |
1509 | * Returns zero on good version; non-zero otherwise | |
1510 | */ | |
1511 | static int ecryptfs_verify_version(u16 version) | |
1512 | { | |
1513 | int rc = 0; | |
1514 | unsigned char major; | |
1515 | unsigned char minor; | |
1516 | ||
1517 | major = ((version >> 8) & 0xFF); | |
1518 | minor = (version & 0xFF); | |
1519 | if (major != ECRYPTFS_VERSION_MAJOR) { | |
1520 | ecryptfs_printk(KERN_ERR, "Major version number mismatch. " | |
1521 | "Expected [%d]; got [%d]\n", | |
1522 | ECRYPTFS_VERSION_MAJOR, major); | |
1523 | rc = -EINVAL; | |
1524 | goto out; | |
1525 | } | |
1526 | if (minor != ECRYPTFS_VERSION_MINOR) { | |
1527 | ecryptfs_printk(KERN_ERR, "Minor version number mismatch. " | |
1528 | "Expected [%d]; got [%d]\n", | |
1529 | ECRYPTFS_VERSION_MINOR, minor); | |
1530 | rc = -EINVAL; | |
1531 | goto out; | |
1532 | } | |
1533 | out: | |
1534 | return rc; | |
1535 | } | |
1536 | ||
1537 | int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key, | |
1538 | struct ecryptfs_auth_tok **auth_tok, | |
1539 | char *sig) | |
1540 | { | |
1541 | int rc = 0; | |
1542 | ||
1543 | (*auth_tok_key) = request_key(&key_type_user, sig, NULL); | |
1544 | if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) { | |
1545 | printk(KERN_ERR "Could not find key with description: [%s]\n", | |
1546 | sig); | |
982363c9 | 1547 | rc = process_request_key_err(PTR_ERR(*auth_tok_key)); |
f4aad16a MH |
1548 | goto out; |
1549 | } | |
1550 | (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key); | |
1551 | if (ecryptfs_verify_version((*auth_tok)->version)) { | |
1552 | printk(KERN_ERR | |
1553 | "Data structure version mismatch. " | |
1554 | "Userspace tools must match eCryptfs " | |
1555 | "kernel module with major version [%d] " | |
1556 | "and minor version [%d]\n", | |
1557 | ECRYPTFS_VERSION_MAJOR, | |
1558 | ECRYPTFS_VERSION_MINOR); | |
1559 | rc = -EINVAL; | |
1560 | goto out; | |
1561 | } | |
1562 | if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD | |
1563 | && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) { | |
1564 | printk(KERN_ERR "Invalid auth_tok structure " | |
1565 | "returned from key query\n"); | |
1566 | rc = -EINVAL; | |
1567 | goto out; | |
1568 | } | |
1569 | out: | |
1570 | return rc; | |
1571 | } | |
1572 | ||
f4aad16a | 1573 | /** |
22e78faf MH |
1574 | * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok. |
1575 | * @auth_tok: The passphrase authentication token to use to encrypt the FEK | |
1576 | * @crypt_stat: The cryptographic context | |
237fead6 | 1577 | * |
22e78faf | 1578 | * Returns zero on success; non-zero error otherwise |
237fead6 | 1579 | */ |
f4aad16a MH |
1580 | static int |
1581 | decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, | |
1582 | struct ecryptfs_crypt_stat *crypt_stat) | |
237fead6 | 1583 | { |
ac97b9f9 MH |
1584 | struct scatterlist dst_sg[2]; |
1585 | struct scatterlist src_sg[2]; | |
dd8e2902 | 1586 | struct mutex *tfm_mutex; |
8bba066f MH |
1587 | struct blkcipher_desc desc = { |
1588 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
1589 | }; | |
1590 | int rc = 0; | |
237fead6 | 1591 | |
f4aad16a MH |
1592 | if (unlikely(ecryptfs_verbosity > 0)) { |
1593 | ecryptfs_printk( | |
1594 | KERN_DEBUG, "Session key encryption key (size [%d]):\n", | |
1595 | auth_tok->token.password.session_key_encryption_key_bytes); | |
1596 | ecryptfs_dump_hex( | |
1597 | auth_tok->token.password.session_key_encryption_key, | |
1598 | auth_tok->token.password.session_key_encryption_key_bytes); | |
1599 | } | |
1600 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex, | |
1601 | crypt_stat->cipher); | |
1602 | if (unlikely(rc)) { | |
1603 | printk(KERN_ERR "Internal error whilst attempting to get " | |
1604 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
1605 | crypt_stat->cipher, rc); | |
1606 | goto out; | |
237fead6 | 1607 | } |
5dda6992 MH |
1608 | rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key, |
1609 | auth_tok->session_key.encrypted_key_size, | |
ac97b9f9 MH |
1610 | src_sg, 2); |
1611 | if (rc < 1 || rc > 2) { | |
f4aad16a MH |
1612 | printk(KERN_ERR "Internal error whilst attempting to convert " |
1613 | "auth_tok->session_key.encrypted_key to scatterlist; " | |
1614 | "expected rc = 1; got rc = [%d]. " | |
1615 | "auth_tok->session_key.encrypted_key_size = [%d]\n", rc, | |
1616 | auth_tok->session_key.encrypted_key_size); | |
1617 | goto out; | |
1618 | } | |
1619 | auth_tok->session_key.decrypted_key_size = | |
1620 | auth_tok->session_key.encrypted_key_size; | |
5dda6992 MH |
1621 | rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key, |
1622 | auth_tok->session_key.decrypted_key_size, | |
ac97b9f9 MH |
1623 | dst_sg, 2); |
1624 | if (rc < 1 || rc > 2) { | |
f4aad16a MH |
1625 | printk(KERN_ERR "Internal error whilst attempting to convert " |
1626 | "auth_tok->session_key.decrypted_key to scatterlist; " | |
1627 | "expected rc = 1; got rc = [%d]\n", rc); | |
1628 | goto out; | |
1629 | } | |
1630 | mutex_lock(tfm_mutex); | |
1631 | rc = crypto_blkcipher_setkey( | |
1632 | desc.tfm, auth_tok->token.password.session_key_encryption_key, | |
1633 | crypt_stat->key_size); | |
1634 | if (unlikely(rc < 0)) { | |
1635 | mutex_unlock(tfm_mutex); | |
e5d9cbde MH |
1636 | printk(KERN_ERR "Error setting key for crypto context\n"); |
1637 | rc = -EINVAL; | |
f4aad16a | 1638 | goto out; |
237fead6 | 1639 | } |
ac97b9f9 | 1640 | rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg, |
8bba066f | 1641 | auth_tok->session_key.encrypted_key_size); |
f4aad16a MH |
1642 | mutex_unlock(tfm_mutex); |
1643 | if (unlikely(rc)) { | |
8bba066f | 1644 | printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc); |
f4aad16a | 1645 | goto out; |
8bba066f | 1646 | } |
237fead6 MH |
1647 | auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; |
1648 | memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, | |
1649 | auth_tok->session_key.decrypted_key_size); | |
e2bd99ec | 1650 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; |
f4aad16a MH |
1651 | if (unlikely(ecryptfs_verbosity > 0)) { |
1652 | ecryptfs_printk(KERN_DEBUG, "FEK of size [%d]:\n", | |
1653 | crypt_stat->key_size); | |
237fead6 MH |
1654 | ecryptfs_dump_hex(crypt_stat->key, |
1655 | crypt_stat->key_size); | |
f4aad16a | 1656 | } |
237fead6 MH |
1657 | out: |
1658 | return rc; | |
1659 | } | |
1660 | ||
1661 | /** | |
1662 | * ecryptfs_parse_packet_set | |
22e78faf MH |
1663 | * @crypt_stat: The cryptographic context |
1664 | * @src: Virtual address of region of memory containing the packets | |
1665 | * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set | |
237fead6 MH |
1666 | * |
1667 | * Get crypt_stat to have the file's session key if the requisite key | |
1668 | * is available to decrypt the session key. | |
1669 | * | |
1670 | * Returns Zero if a valid authentication token was retrieved and | |
1671 | * processed; negative value for file not encrypted or for error | |
1672 | * conditions. | |
1673 | */ | |
1674 | int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat, | |
1675 | unsigned char *src, | |
1676 | struct dentry *ecryptfs_dentry) | |
1677 | { | |
1678 | size_t i = 0; | |
f4aad16a | 1679 | size_t found_auth_tok; |
237fead6 | 1680 | size_t next_packet_is_auth_tok_packet; |
237fead6 | 1681 | struct list_head auth_tok_list; |
dd8e2902 MH |
1682 | struct ecryptfs_auth_tok *matching_auth_tok; |
1683 | struct ecryptfs_auth_tok *candidate_auth_tok; | |
f4aad16a | 1684 | char *candidate_auth_tok_sig; |
237fead6 MH |
1685 | size_t packet_size; |
1686 | struct ecryptfs_auth_tok *new_auth_tok; | |
1687 | unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE]; | |
f4aad16a | 1688 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
237fead6 MH |
1689 | size_t tag_11_contents_size; |
1690 | size_t tag_11_packet_size; | |
dddfa461 | 1691 | int rc = 0; |
237fead6 MH |
1692 | |
1693 | INIT_LIST_HEAD(&auth_tok_list); | |
f4aad16a | 1694 | /* Parse the header to find as many packets as we can; these will be |
237fead6 MH |
1695 | * added the our &auth_tok_list */ |
1696 | next_packet_is_auth_tok_packet = 1; | |
1697 | while (next_packet_is_auth_tok_packet) { | |
1698 | size_t max_packet_size = ((PAGE_CACHE_SIZE - 8) - i); | |
1699 | ||
1700 | switch (src[i]) { | |
1701 | case ECRYPTFS_TAG_3_PACKET_TYPE: | |
1702 | rc = parse_tag_3_packet(crypt_stat, | |
1703 | (unsigned char *)&src[i], | |
1704 | &auth_tok_list, &new_auth_tok, | |
1705 | &packet_size, max_packet_size); | |
1706 | if (rc) { | |
1707 | ecryptfs_printk(KERN_ERR, "Error parsing " | |
1708 | "tag 3 packet\n"); | |
1709 | rc = -EIO; | |
1710 | goto out_wipe_list; | |
1711 | } | |
1712 | i += packet_size; | |
1713 | rc = parse_tag_11_packet((unsigned char *)&src[i], | |
1714 | sig_tmp_space, | |
1715 | ECRYPTFS_SIG_SIZE, | |
1716 | &tag_11_contents_size, | |
1717 | &tag_11_packet_size, | |
1718 | max_packet_size); | |
1719 | if (rc) { | |
1720 | ecryptfs_printk(KERN_ERR, "No valid " | |
1721 | "(ecryptfs-specific) literal " | |
1722 | "packet containing " | |
1723 | "authentication token " | |
1724 | "signature found after " | |
1725 | "tag 3 packet\n"); | |
1726 | rc = -EIO; | |
1727 | goto out_wipe_list; | |
1728 | } | |
1729 | i += tag_11_packet_size; | |
1730 | if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) { | |
1731 | ecryptfs_printk(KERN_ERR, "Expected " | |
1732 | "signature of size [%d]; " | |
1733 | "read size [%d]\n", | |
1734 | ECRYPTFS_SIG_SIZE, | |
1735 | tag_11_contents_size); | |
1736 | rc = -EIO; | |
1737 | goto out_wipe_list; | |
1738 | } | |
1739 | ecryptfs_to_hex(new_auth_tok->token.password.signature, | |
1740 | sig_tmp_space, tag_11_contents_size); | |
1741 | new_auth_tok->token.password.signature[ | |
1742 | ECRYPTFS_PASSWORD_SIG_SIZE] = '\0'; | |
e2bd99ec | 1743 | crypt_stat->flags |= ECRYPTFS_ENCRYPTED; |
237fead6 | 1744 | break; |
dddfa461 MH |
1745 | case ECRYPTFS_TAG_1_PACKET_TYPE: |
1746 | rc = parse_tag_1_packet(crypt_stat, | |
1747 | (unsigned char *)&src[i], | |
1748 | &auth_tok_list, &new_auth_tok, | |
1749 | &packet_size, max_packet_size); | |
1750 | if (rc) { | |
1751 | ecryptfs_printk(KERN_ERR, "Error parsing " | |
1752 | "tag 1 packet\n"); | |
1753 | rc = -EIO; | |
1754 | goto out_wipe_list; | |
1755 | } | |
1756 | i += packet_size; | |
e2bd99ec | 1757 | crypt_stat->flags |= ECRYPTFS_ENCRYPTED; |
dddfa461 | 1758 | break; |
237fead6 MH |
1759 | case ECRYPTFS_TAG_11_PACKET_TYPE: |
1760 | ecryptfs_printk(KERN_WARNING, "Invalid packet set " | |
1761 | "(Tag 11 not allowed by itself)\n"); | |
1762 | rc = -EIO; | |
1763 | goto out_wipe_list; | |
1764 | break; | |
1765 | default: | |
1766 | ecryptfs_printk(KERN_DEBUG, "No packet at offset " | |
1767 | "[%d] of the file header; hex value of " | |
1768 | "character is [0x%.2x]\n", i, src[i]); | |
1769 | next_packet_is_auth_tok_packet = 0; | |
1770 | } | |
1771 | } | |
1772 | if (list_empty(&auth_tok_list)) { | |
f4aad16a MH |
1773 | printk(KERN_ERR "The lower file appears to be a non-encrypted " |
1774 | "eCryptfs file; this is not supported in this version " | |
1775 | "of the eCryptfs kernel module\n"); | |
1776 | rc = -EINVAL; | |
237fead6 MH |
1777 | goto out; |
1778 | } | |
f4aad16a MH |
1779 | /* auth_tok_list contains the set of authentication tokens |
1780 | * parsed from the metadata. We need to find a matching | |
1781 | * authentication token that has the secret component(s) | |
1782 | * necessary to decrypt the EFEK in the auth_tok parsed from | |
1783 | * the metadata. There may be several potential matches, but | |
1784 | * just one will be sufficient to decrypt to get the FEK. */ | |
1785 | find_next_matching_auth_tok: | |
1786 | found_auth_tok = 0; | |
1787 | list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) { | |
237fead6 MH |
1788 | candidate_auth_tok = &auth_tok_list_item->auth_tok; |
1789 | if (unlikely(ecryptfs_verbosity > 0)) { | |
1790 | ecryptfs_printk(KERN_DEBUG, | |
1791 | "Considering cadidate auth tok:\n"); | |
1792 | ecryptfs_dump_auth_tok(candidate_auth_tok); | |
1793 | } | |
5dda6992 MH |
1794 | rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig, |
1795 | candidate_auth_tok); | |
1796 | if (rc) { | |
f4aad16a MH |
1797 | printk(KERN_ERR |
1798 | "Unrecognized candidate auth tok type: [%d]\n", | |
1799 | candidate_auth_tok->token_type); | |
1800 | rc = -EINVAL; | |
1801 | goto out_wipe_list; | |
1802 | } | |
9c79f34f MH |
1803 | ecryptfs_find_auth_tok_for_sig(&matching_auth_tok, |
1804 | crypt_stat->mount_crypt_stat, | |
5dda6992 | 1805 | candidate_auth_tok_sig); |
f4aad16a | 1806 | if (matching_auth_tok) { |
dddfa461 | 1807 | found_auth_tok = 1; |
f4aad16a | 1808 | goto found_matching_auth_tok; |
237fead6 MH |
1809 | } |
1810 | } | |
237fead6 | 1811 | if (!found_auth_tok) { |
f4aad16a MH |
1812 | ecryptfs_printk(KERN_ERR, "Could not find a usable " |
1813 | "authentication token\n"); | |
237fead6 MH |
1814 | rc = -EIO; |
1815 | goto out_wipe_list; | |
dddfa461 | 1816 | } |
f4aad16a | 1817 | found_matching_auth_tok: |
e2bd99ec | 1818 | if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
dddfa461 | 1819 | memcpy(&(candidate_auth_tok->token.private_key), |
f4aad16a | 1820 | &(matching_auth_tok->token.private_key), |
dddfa461 | 1821 | sizeof(struct ecryptfs_private_key)); |
f4aad16a | 1822 | rc = decrypt_pki_encrypted_session_key(candidate_auth_tok, |
dddfa461 MH |
1823 | crypt_stat); |
1824 | } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) { | |
237fead6 | 1825 | memcpy(&(candidate_auth_tok->token.password), |
f4aad16a | 1826 | &(matching_auth_tok->token.password), |
237fead6 | 1827 | sizeof(struct ecryptfs_password)); |
f4aad16a MH |
1828 | rc = decrypt_passphrase_encrypted_session_key( |
1829 | candidate_auth_tok, crypt_stat); | |
dddfa461 MH |
1830 | } |
1831 | if (rc) { | |
f4aad16a MH |
1832 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
1833 | ||
1834 | ecryptfs_printk(KERN_WARNING, "Error decrypting the " | |
1835 | "session key for authentication token with sig " | |
1836 | "[%.*s]; rc = [%d]. Removing auth tok " | |
1837 | "candidate from the list and searching for " | |
1838 | "the next match.\n", candidate_auth_tok_sig, | |
1839 | ECRYPTFS_SIG_SIZE_HEX, rc); | |
1840 | list_for_each_entry_safe(auth_tok_list_item, | |
1841 | auth_tok_list_item_tmp, | |
1842 | &auth_tok_list, list) { | |
1843 | if (candidate_auth_tok | |
1844 | == &auth_tok_list_item->auth_tok) { | |
1845 | list_del(&auth_tok_list_item->list); | |
1846 | kmem_cache_free( | |
1847 | ecryptfs_auth_tok_list_item_cache, | |
1848 | auth_tok_list_item); | |
1849 | goto find_next_matching_auth_tok; | |
1850 | } | |
1851 | } | |
1852 | BUG(); | |
dddfa461 MH |
1853 | } |
1854 | rc = ecryptfs_compute_root_iv(crypt_stat); | |
1855 | if (rc) { | |
1856 | ecryptfs_printk(KERN_ERR, "Error computing " | |
1857 | "the root IV\n"); | |
1858 | goto out_wipe_list; | |
237fead6 MH |
1859 | } |
1860 | rc = ecryptfs_init_crypt_ctx(crypt_stat); | |
1861 | if (rc) { | |
1862 | ecryptfs_printk(KERN_ERR, "Error initializing crypto " | |
1863 | "context for cipher [%s]; rc = [%d]\n", | |
1864 | crypt_stat->cipher, rc); | |
1865 | } | |
1866 | out_wipe_list: | |
1867 | wipe_auth_tok_list(&auth_tok_list); | |
1868 | out: | |
1869 | return rc; | |
1870 | } | |
f4aad16a | 1871 | |
dddfa461 MH |
1872 | static int |
1873 | pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok, | |
1874 | struct ecryptfs_crypt_stat *crypt_stat, | |
1875 | struct ecryptfs_key_record *key_rec) | |
1876 | { | |
1877 | struct ecryptfs_msg_ctx *msg_ctx = NULL; | |
624ae528 TH |
1878 | char *payload = NULL; |
1879 | size_t payload_len; | |
dddfa461 MH |
1880 | struct ecryptfs_message *msg; |
1881 | int rc; | |
1882 | ||
1883 | rc = write_tag_66_packet(auth_tok->token.private_key.signature, | |
9c79f34f MH |
1884 | ecryptfs_code_for_cipher_string( |
1885 | crypt_stat->cipher, | |
1886 | crypt_stat->key_size), | |
624ae528 | 1887 | crypt_stat, &payload, &payload_len); |
dddfa461 MH |
1888 | if (rc) { |
1889 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n"); | |
1890 | goto out; | |
1891 | } | |
624ae528 | 1892 | rc = ecryptfs_send_message(payload, payload_len, &msg_ctx); |
dddfa461 | 1893 | if (rc) { |
624ae528 TH |
1894 | ecryptfs_printk(KERN_ERR, "Error sending message to " |
1895 | "ecryptfsd\n"); | |
dddfa461 MH |
1896 | goto out; |
1897 | } | |
1898 | rc = ecryptfs_wait_for_response(msg_ctx, &msg); | |
1899 | if (rc) { | |
1900 | ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet " | |
1901 | "from the user space daemon\n"); | |
1902 | rc = -EIO; | |
1903 | goto out; | |
1904 | } | |
1905 | rc = parse_tag_67_packet(key_rec, msg); | |
1906 | if (rc) | |
1907 | ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n"); | |
1908 | kfree(msg); | |
1909 | out: | |
624ae528 | 1910 | kfree(payload); |
dddfa461 MH |
1911 | return rc; |
1912 | } | |
1913 | /** | |
1914 | * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet | |
1915 | * @dest: Buffer into which to write the packet | |
22e78faf MH |
1916 | * @remaining_bytes: Maximum number of bytes that can be writtn |
1917 | * @auth_tok: The authentication token used for generating the tag 1 packet | |
1918 | * @crypt_stat: The cryptographic context | |
1919 | * @key_rec: The key record struct for the tag 1 packet | |
dddfa461 MH |
1920 | * @packet_size: This function will write the number of bytes that end |
1921 | * up constituting the packet; set to zero on error | |
1922 | * | |
1923 | * Returns zero on success; non-zero on error. | |
1924 | */ | |
1925 | static int | |
f4aad16a MH |
1926 | write_tag_1_packet(char *dest, size_t *remaining_bytes, |
1927 | struct ecryptfs_auth_tok *auth_tok, | |
dddfa461 | 1928 | struct ecryptfs_crypt_stat *crypt_stat, |
dddfa461 MH |
1929 | struct ecryptfs_key_record *key_rec, size_t *packet_size) |
1930 | { | |
1931 | size_t i; | |
1932 | size_t encrypted_session_key_valid = 0; | |
dddfa461 | 1933 | size_t packet_size_length; |
f4aad16a | 1934 | size_t max_packet_size; |
dddfa461 MH |
1935 | int rc = 0; |
1936 | ||
1937 | (*packet_size) = 0; | |
1938 | ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature, | |
1939 | ECRYPTFS_SIG_SIZE); | |
1940 | encrypted_session_key_valid = 0; | |
1941 | for (i = 0; i < crypt_stat->key_size; i++) | |
1942 | encrypted_session_key_valid |= | |
1943 | auth_tok->session_key.encrypted_key[i]; | |
1944 | if (encrypted_session_key_valid) { | |
1945 | memcpy(key_rec->enc_key, | |
1946 | auth_tok->session_key.encrypted_key, | |
1947 | auth_tok->session_key.encrypted_key_size); | |
1948 | goto encrypted_session_key_set; | |
1949 | } | |
1950 | if (auth_tok->session_key.encrypted_key_size == 0) | |
1951 | auth_tok->session_key.encrypted_key_size = | |
1952 | auth_tok->token.private_key.key_size; | |
1953 | rc = pki_encrypt_session_key(auth_tok, crypt_stat, key_rec); | |
1954 | if (rc) { | |
f66e883e MH |
1955 | printk(KERN_ERR "Failed to encrypt session key via a key " |
1956 | "module; rc = [%d]\n", rc); | |
dddfa461 MH |
1957 | goto out; |
1958 | } | |
1959 | if (ecryptfs_verbosity > 0) { | |
1960 | ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n"); | |
1961 | ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size); | |
1962 | } | |
1963 | encrypted_session_key_set: | |
f4aad16a MH |
1964 | /* This format is inspired by OpenPGP; see RFC 2440 |
1965 | * packet tag 1 */ | |
1966 | max_packet_size = (1 /* Tag 1 identifier */ | |
1967 | + 3 /* Max Tag 1 packet size */ | |
1968 | + 1 /* Version */ | |
1969 | + ECRYPTFS_SIG_SIZE /* Key identifier */ | |
1970 | + 1 /* Cipher identifier */ | |
1971 | + key_rec->enc_key_size); /* Encrypted key size */ | |
1972 | if (max_packet_size > (*remaining_bytes)) { | |
1973 | printk(KERN_ERR "Packet length larger than maximum allowable; " | |
81acbcd6 | 1974 | "need up to [%td] bytes, but there are only [%td] " |
f4aad16a | 1975 | "available\n", max_packet_size, (*remaining_bytes)); |
dddfa461 MH |
1976 | rc = -EINVAL; |
1977 | goto out; | |
1978 | } | |
1979 | dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE; | |
f66e883e MH |
1980 | rc = ecryptfs_write_packet_length(&dest[(*packet_size)], |
1981 | (max_packet_size - 4), | |
1982 | &packet_size_length); | |
dddfa461 MH |
1983 | if (rc) { |
1984 | ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet " | |
1985 | "header; cannot generate packet length\n"); | |
1986 | goto out; | |
1987 | } | |
1988 | (*packet_size) += packet_size_length; | |
1989 | dest[(*packet_size)++] = 0x03; /* version 3 */ | |
1990 | memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE); | |
1991 | (*packet_size) += ECRYPTFS_SIG_SIZE; | |
1992 | dest[(*packet_size)++] = RFC2440_CIPHER_RSA; | |
1993 | memcpy(&dest[(*packet_size)], key_rec->enc_key, | |
1994 | key_rec->enc_key_size); | |
1995 | (*packet_size) += key_rec->enc_key_size; | |
1996 | out: | |
1997 | if (rc) | |
1998 | (*packet_size) = 0; | |
f4aad16a MH |
1999 | else |
2000 | (*remaining_bytes) -= (*packet_size); | |
dddfa461 MH |
2001 | return rc; |
2002 | } | |
237fead6 MH |
2003 | |
2004 | /** | |
2005 | * write_tag_11_packet | |
2006 | * @dest: Target into which Tag 11 packet is to be written | |
22e78faf | 2007 | * @remaining_bytes: Maximum packet length |
237fead6 MH |
2008 | * @contents: Byte array of contents to copy in |
2009 | * @contents_length: Number of bytes in contents | |
2010 | * @packet_length: Length of the Tag 11 packet written; zero on error | |
2011 | * | |
2012 | * Returns zero on success; non-zero on error. | |
2013 | */ | |
2014 | static int | |
81acbcd6 | 2015 | write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents, |
146a4606 | 2016 | size_t contents_length, size_t *packet_length) |
237fead6 | 2017 | { |
237fead6 | 2018 | size_t packet_size_length; |
146a4606 | 2019 | size_t max_packet_size; |
dddfa461 | 2020 | int rc = 0; |
237fead6 MH |
2021 | |
2022 | (*packet_length) = 0; | |
146a4606 MH |
2023 | /* This format is inspired by OpenPGP; see RFC 2440 |
2024 | * packet tag 11 */ | |
2025 | max_packet_size = (1 /* Tag 11 identifier */ | |
2026 | + 3 /* Max Tag 11 packet size */ | |
2027 | + 1 /* Binary format specifier */ | |
2028 | + 1 /* Filename length */ | |
2029 | + 8 /* Filename ("_CONSOLE") */ | |
2030 | + 4 /* Modification date */ | |
2031 | + contents_length); /* Literal data */ | |
2032 | if (max_packet_size > (*remaining_bytes)) { | |
2033 | printk(KERN_ERR "Packet length larger than maximum allowable; " | |
81acbcd6 | 2034 | "need up to [%td] bytes, but there are only [%td] " |
146a4606 | 2035 | "available\n", max_packet_size, (*remaining_bytes)); |
237fead6 | 2036 | rc = -EINVAL; |
237fead6 MH |
2037 | goto out; |
2038 | } | |
237fead6 | 2039 | dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE; |
f66e883e MH |
2040 | rc = ecryptfs_write_packet_length(&dest[(*packet_length)], |
2041 | (max_packet_size - 4), | |
2042 | &packet_size_length); | |
237fead6 | 2043 | if (rc) { |
146a4606 MH |
2044 | printk(KERN_ERR "Error generating tag 11 packet header; cannot " |
2045 | "generate packet length. rc = [%d]\n", rc); | |
237fead6 MH |
2046 | goto out; |
2047 | } | |
2048 | (*packet_length) += packet_size_length; | |
146a4606 | 2049 | dest[(*packet_length)++] = 0x62; /* binary data format specifier */ |
237fead6 MH |
2050 | dest[(*packet_length)++] = 8; |
2051 | memcpy(&dest[(*packet_length)], "_CONSOLE", 8); | |
2052 | (*packet_length) += 8; | |
237fead6 MH |
2053 | memset(&dest[(*packet_length)], 0x00, 4); |
2054 | (*packet_length) += 4; | |
237fead6 MH |
2055 | memcpy(&dest[(*packet_length)], contents, contents_length); |
2056 | (*packet_length) += contents_length; | |
2057 | out: | |
2058 | if (rc) | |
2059 | (*packet_length) = 0; | |
146a4606 MH |
2060 | else |
2061 | (*remaining_bytes) -= (*packet_length); | |
237fead6 MH |
2062 | return rc; |
2063 | } | |
2064 | ||
2065 | /** | |
2066 | * write_tag_3_packet | |
2067 | * @dest: Buffer into which to write the packet | |
22e78faf | 2068 | * @remaining_bytes: Maximum number of bytes that can be written |
237fead6 MH |
2069 | * @auth_tok: Authentication token |
2070 | * @crypt_stat: The cryptographic context | |
2071 | * @key_rec: encrypted key | |
2072 | * @packet_size: This function will write the number of bytes that end | |
2073 | * up constituting the packet; set to zero on error | |
2074 | * | |
2075 | * Returns zero on success; non-zero on error. | |
2076 | */ | |
2077 | static int | |
f4aad16a MH |
2078 | write_tag_3_packet(char *dest, size_t *remaining_bytes, |
2079 | struct ecryptfs_auth_tok *auth_tok, | |
237fead6 MH |
2080 | struct ecryptfs_crypt_stat *crypt_stat, |
2081 | struct ecryptfs_key_record *key_rec, size_t *packet_size) | |
2082 | { | |
237fead6 | 2083 | size_t i; |
237fead6 MH |
2084 | size_t encrypted_session_key_valid = 0; |
2085 | char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES]; | |
ac97b9f9 MH |
2086 | struct scatterlist dst_sg[2]; |
2087 | struct scatterlist src_sg[2]; | |
237fead6 | 2088 | struct mutex *tfm_mutex = NULL; |
19e66a67 | 2089 | u8 cipher_code; |
f4aad16a MH |
2090 | size_t packet_size_length; |
2091 | size_t max_packet_size; | |
2092 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = | |
2093 | crypt_stat->mount_crypt_stat; | |
8bba066f MH |
2094 | struct blkcipher_desc desc = { |
2095 | .tfm = NULL, | |
2096 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
2097 | }; | |
2098 | int rc = 0; | |
237fead6 MH |
2099 | |
2100 | (*packet_size) = 0; | |
dddfa461 | 2101 | ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature, |
237fead6 | 2102 | ECRYPTFS_SIG_SIZE); |
f4aad16a MH |
2103 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex, |
2104 | crypt_stat->cipher); | |
2105 | if (unlikely(rc)) { | |
2106 | printk(KERN_ERR "Internal error whilst attempting to get " | |
2107 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
2108 | crypt_stat->cipher, rc); | |
2109 | goto out; | |
2110 | } | |
2111 | if (mount_crypt_stat->global_default_cipher_key_size == 0) { | |
2112 | struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm); | |
2113 | ||
2114 | printk(KERN_WARNING "No key size specified at mount; " | |
2115 | "defaulting to [%d]\n", alg->max_keysize); | |
2116 | mount_crypt_stat->global_default_cipher_key_size = | |
2117 | alg->max_keysize; | |
237fead6 | 2118 | } |
f4aad16a MH |
2119 | if (crypt_stat->key_size == 0) |
2120 | crypt_stat->key_size = | |
2121 | mount_crypt_stat->global_default_cipher_key_size; | |
237fead6 MH |
2122 | if (auth_tok->session_key.encrypted_key_size == 0) |
2123 | auth_tok->session_key.encrypted_key_size = | |
2124 | crypt_stat->key_size; | |
2125 | if (crypt_stat->key_size == 24 | |
2126 | && strcmp("aes", crypt_stat->cipher) == 0) { | |
2127 | memset((crypt_stat->key + 24), 0, 8); | |
2128 | auth_tok->session_key.encrypted_key_size = 32; | |
f4aad16a MH |
2129 | } else |
2130 | auth_tok->session_key.encrypted_key_size = crypt_stat->key_size; | |
dddfa461 | 2131 | key_rec->enc_key_size = |
237fead6 | 2132 | auth_tok->session_key.encrypted_key_size; |
f4aad16a MH |
2133 | encrypted_session_key_valid = 0; |
2134 | for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++) | |
2135 | encrypted_session_key_valid |= | |
2136 | auth_tok->session_key.encrypted_key[i]; | |
2137 | if (encrypted_session_key_valid) { | |
2138 | ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; " | |
2139 | "using auth_tok->session_key.encrypted_key, " | |
2140 | "where key_rec->enc_key_size = [%d]\n", | |
2141 | key_rec->enc_key_size); | |
2142 | memcpy(key_rec->enc_key, | |
2143 | auth_tok->session_key.encrypted_key, | |
2144 | key_rec->enc_key_size); | |
2145 | goto encrypted_session_key_set; | |
2146 | } | |
dddfa461 MH |
2147 | if (auth_tok->token.password.flags & |
2148 | ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) { | |
237fead6 MH |
2149 | ecryptfs_printk(KERN_DEBUG, "Using previously generated " |
2150 | "session key encryption key of size [%d]\n", | |
2151 | auth_tok->token.password. | |
2152 | session_key_encryption_key_bytes); | |
2153 | memcpy(session_key_encryption_key, | |
2154 | auth_tok->token.password.session_key_encryption_key, | |
2155 | crypt_stat->key_size); | |
2156 | ecryptfs_printk(KERN_DEBUG, | |
2157 | "Cached session key " "encryption key: \n"); | |
2158 | if (ecryptfs_verbosity > 0) | |
2159 | ecryptfs_dump_hex(session_key_encryption_key, 16); | |
2160 | } | |
2161 | if (unlikely(ecryptfs_verbosity > 0)) { | |
2162 | ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n"); | |
2163 | ecryptfs_dump_hex(session_key_encryption_key, 16); | |
2164 | } | |
5dda6992 | 2165 | rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size, |
ac97b9f9 MH |
2166 | src_sg, 2); |
2167 | if (rc < 1 || rc > 2) { | |
237fead6 | 2168 | ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
f4aad16a MH |
2169 | "for crypt_stat session key; expected rc = 1; " |
2170 | "got rc = [%d]. key_rec->enc_key_size = [%d]\n", | |
2171 | rc, key_rec->enc_key_size); | |
237fead6 MH |
2172 | rc = -ENOMEM; |
2173 | goto out; | |
2174 | } | |
5dda6992 | 2175 | rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size, |
ac97b9f9 MH |
2176 | dst_sg, 2); |
2177 | if (rc < 1 || rc > 2) { | |
237fead6 | 2178 | ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
f4aad16a MH |
2179 | "for crypt_stat encrypted session key; " |
2180 | "expected rc = 1; got rc = [%d]. " | |
2181 | "key_rec->enc_key_size = [%d]\n", rc, | |
2182 | key_rec->enc_key_size); | |
237fead6 MH |
2183 | rc = -ENOMEM; |
2184 | goto out; | |
2185 | } | |
f4aad16a | 2186 | mutex_lock(tfm_mutex); |
8bba066f MH |
2187 | rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key, |
2188 | crypt_stat->key_size); | |
237fead6 | 2189 | if (rc < 0) { |
f4aad16a | 2190 | mutex_unlock(tfm_mutex); |
237fead6 | 2191 | ecryptfs_printk(KERN_ERR, "Error setting key for crypto " |
8bba066f | 2192 | "context; rc = [%d]\n", rc); |
237fead6 MH |
2193 | goto out; |
2194 | } | |
2195 | rc = 0; | |
2196 | ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n", | |
2197 | crypt_stat->key_size); | |
ac97b9f9 | 2198 | rc = crypto_blkcipher_encrypt(&desc, dst_sg, src_sg, |
8bba066f | 2199 | (*key_rec).enc_key_size); |
f4aad16a | 2200 | mutex_unlock(tfm_mutex); |
8bba066f MH |
2201 | if (rc) { |
2202 | printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc); | |
2203 | goto out; | |
2204 | } | |
237fead6 | 2205 | ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n"); |
f4aad16a MH |
2206 | if (ecryptfs_verbosity > 0) { |
2207 | ecryptfs_printk(KERN_DEBUG, "EFEK of size [%d]:\n", | |
2208 | key_rec->enc_key_size); | |
dddfa461 MH |
2209 | ecryptfs_dump_hex(key_rec->enc_key, |
2210 | key_rec->enc_key_size); | |
237fead6 | 2211 | } |
f4aad16a MH |
2212 | encrypted_session_key_set: |
2213 | /* This format is inspired by OpenPGP; see RFC 2440 | |
2214 | * packet tag 3 */ | |
2215 | max_packet_size = (1 /* Tag 3 identifier */ | |
2216 | + 3 /* Max Tag 3 packet size */ | |
2217 | + 1 /* Version */ | |
2218 | + 1 /* Cipher code */ | |
2219 | + 1 /* S2K specifier */ | |
2220 | + 1 /* Hash identifier */ | |
2221 | + ECRYPTFS_SALT_SIZE /* Salt */ | |
2222 | + 1 /* Hash iterations */ | |
2223 | + key_rec->enc_key_size); /* Encrypted key size */ | |
2224 | if (max_packet_size > (*remaining_bytes)) { | |
81acbcd6 AM |
2225 | printk(KERN_ERR "Packet too large; need up to [%td] bytes, but " |
2226 | "there are only [%td] available\n", max_packet_size, | |
f4aad16a | 2227 | (*remaining_bytes)); |
237fead6 MH |
2228 | rc = -EINVAL; |
2229 | goto out; | |
2230 | } | |
237fead6 | 2231 | dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE; |
f4aad16a MH |
2232 | /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3) |
2233 | * to get the number of octets in the actual Tag 3 packet */ | |
f66e883e MH |
2234 | rc = ecryptfs_write_packet_length(&dest[(*packet_size)], |
2235 | (max_packet_size - 4), | |
2236 | &packet_size_length); | |
237fead6 | 2237 | if (rc) { |
f4aad16a MH |
2238 | printk(KERN_ERR "Error generating tag 3 packet header; cannot " |
2239 | "generate packet length. rc = [%d]\n", rc); | |
237fead6 MH |
2240 | goto out; |
2241 | } | |
2242 | (*packet_size) += packet_size_length; | |
2243 | dest[(*packet_size)++] = 0x04; /* version 4 */ | |
f4aad16a MH |
2244 | /* TODO: Break from RFC2440 so that arbitrary ciphers can be |
2245 | * specified with strings */ | |
9c79f34f MH |
2246 | cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher, |
2247 | crypt_stat->key_size); | |
237fead6 MH |
2248 | if (cipher_code == 0) { |
2249 | ecryptfs_printk(KERN_WARNING, "Unable to generate code for " | |
2250 | "cipher [%s]\n", crypt_stat->cipher); | |
2251 | rc = -EINVAL; | |
2252 | goto out; | |
2253 | } | |
2254 | dest[(*packet_size)++] = cipher_code; | |
2255 | dest[(*packet_size)++] = 0x03; /* S2K */ | |
2256 | dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */ | |
2257 | memcpy(&dest[(*packet_size)], auth_tok->token.password.salt, | |
2258 | ECRYPTFS_SALT_SIZE); | |
2259 | (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */ | |
2260 | dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */ | |
dddfa461 MH |
2261 | memcpy(&dest[(*packet_size)], key_rec->enc_key, |
2262 | key_rec->enc_key_size); | |
2263 | (*packet_size) += key_rec->enc_key_size; | |
237fead6 | 2264 | out: |
237fead6 MH |
2265 | if (rc) |
2266 | (*packet_size) = 0; | |
f4aad16a MH |
2267 | else |
2268 | (*remaining_bytes) -= (*packet_size); | |
237fead6 MH |
2269 | return rc; |
2270 | } | |
2271 | ||
eb95e7ff MH |
2272 | struct kmem_cache *ecryptfs_key_record_cache; |
2273 | ||
237fead6 MH |
2274 | /** |
2275 | * ecryptfs_generate_key_packet_set | |
22e78faf | 2276 | * @dest_base: Virtual address from which to write the key record set |
237fead6 MH |
2277 | * @crypt_stat: The cryptographic context from which the |
2278 | * authentication tokens will be retrieved | |
2279 | * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat | |
2280 | * for the global parameters | |
2281 | * @len: The amount written | |
2282 | * @max: The maximum amount of data allowed to be written | |
2283 | * | |
2284 | * Generates a key packet set and writes it to the virtual address | |
2285 | * passed in. | |
2286 | * | |
2287 | * Returns zero on success; non-zero on error. | |
2288 | */ | |
2289 | int | |
2290 | ecryptfs_generate_key_packet_set(char *dest_base, | |
2291 | struct ecryptfs_crypt_stat *crypt_stat, | |
2292 | struct dentry *ecryptfs_dentry, size_t *len, | |
2293 | size_t max) | |
2294 | { | |
237fead6 | 2295 | struct ecryptfs_auth_tok *auth_tok; |
f4aad16a | 2296 | struct ecryptfs_global_auth_tok *global_auth_tok; |
237fead6 MH |
2297 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
2298 | &ecryptfs_superblock_to_private( | |
2299 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
2300 | size_t written; | |
eb95e7ff | 2301 | struct ecryptfs_key_record *key_rec; |
f4aad16a | 2302 | struct ecryptfs_key_sig *key_sig; |
dddfa461 | 2303 | int rc = 0; |
237fead6 MH |
2304 | |
2305 | (*len) = 0; | |
f4aad16a | 2306 | mutex_lock(&crypt_stat->keysig_list_mutex); |
eb95e7ff MH |
2307 | key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL); |
2308 | if (!key_rec) { | |
2309 | rc = -ENOMEM; | |
2310 | goto out; | |
2311 | } | |
f4aad16a MH |
2312 | list_for_each_entry(key_sig, &crypt_stat->keysig_list, |
2313 | crypt_stat_list) { | |
2314 | memset(key_rec, 0, sizeof(*key_rec)); | |
2315 | rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok, | |
2316 | mount_crypt_stat, | |
2317 | key_sig->keysig); | |
2318 | if (rc) { | |
2319 | printk(KERN_ERR "Error attempting to get the global " | |
2320 | "auth_tok; rc = [%d]\n", rc); | |
2321 | goto out_free; | |
2322 | } | |
2323 | if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) { | |
2324 | printk(KERN_WARNING | |
2325 | "Skipping invalid auth tok with sig = [%s]\n", | |
2326 | global_auth_tok->sig); | |
2327 | continue; | |
2328 | } | |
2329 | auth_tok = global_auth_tok->global_auth_tok; | |
237fead6 MH |
2330 | if (auth_tok->token_type == ECRYPTFS_PASSWORD) { |
2331 | rc = write_tag_3_packet((dest_base + (*len)), | |
f4aad16a | 2332 | &max, auth_tok, |
eb95e7ff | 2333 | crypt_stat, key_rec, |
237fead6 MH |
2334 | &written); |
2335 | if (rc) { | |
2336 | ecryptfs_printk(KERN_WARNING, "Error " | |
2337 | "writing tag 3 packet\n"); | |
eb95e7ff | 2338 | goto out_free; |
237fead6 MH |
2339 | } |
2340 | (*len) += written; | |
2341 | /* Write auth tok signature packet */ | |
f4aad16a MH |
2342 | rc = write_tag_11_packet((dest_base + (*len)), &max, |
2343 | key_rec->sig, | |
2344 | ECRYPTFS_SIG_SIZE, &written); | |
237fead6 MH |
2345 | if (rc) { |
2346 | ecryptfs_printk(KERN_ERR, "Error writing " | |
2347 | "auth tok signature packet\n"); | |
eb95e7ff | 2348 | goto out_free; |
237fead6 MH |
2349 | } |
2350 | (*len) += written; | |
dddfa461 MH |
2351 | } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
2352 | rc = write_tag_1_packet(dest_base + (*len), | |
f4aad16a MH |
2353 | &max, auth_tok, |
2354 | crypt_stat, key_rec, &written); | |
dddfa461 MH |
2355 | if (rc) { |
2356 | ecryptfs_printk(KERN_WARNING, "Error " | |
2357 | "writing tag 1 packet\n"); | |
eb95e7ff | 2358 | goto out_free; |
dddfa461 MH |
2359 | } |
2360 | (*len) += written; | |
237fead6 MH |
2361 | } else { |
2362 | ecryptfs_printk(KERN_WARNING, "Unsupported " | |
2363 | "authentication token type\n"); | |
2364 | rc = -EINVAL; | |
eb95e7ff | 2365 | goto out_free; |
237fead6 | 2366 | } |
f4aad16a MH |
2367 | } |
2368 | if (likely(max > 0)) { | |
237fead6 MH |
2369 | dest_base[(*len)] = 0x00; |
2370 | } else { | |
2371 | ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n"); | |
2372 | rc = -EIO; | |
2373 | } | |
eb95e7ff MH |
2374 | out_free: |
2375 | kmem_cache_free(ecryptfs_key_record_cache, key_rec); | |
237fead6 MH |
2376 | out: |
2377 | if (rc) | |
2378 | (*len) = 0; | |
f4aad16a MH |
2379 | mutex_unlock(&crypt_stat->keysig_list_mutex); |
2380 | return rc; | |
2381 | } | |
2382 | ||
2383 | struct kmem_cache *ecryptfs_key_sig_cache; | |
2384 | ||
2385 | int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig) | |
2386 | { | |
2387 | struct ecryptfs_key_sig *new_key_sig; | |
f4aad16a MH |
2388 | |
2389 | new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL); | |
2390 | if (!new_key_sig) { | |
f4aad16a MH |
2391 | printk(KERN_ERR |
2392 | "Error allocating from ecryptfs_key_sig_cache\n"); | |
aa06117f | 2393 | return -ENOMEM; |
f4aad16a MH |
2394 | } |
2395 | memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX); | |
aa06117f | 2396 | /* Caller must hold keysig_list_mutex */ |
f4aad16a | 2397 | list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list); |
aa06117f RD |
2398 | |
2399 | return 0; | |
237fead6 | 2400 | } |
f4aad16a MH |
2401 | |
2402 | struct kmem_cache *ecryptfs_global_auth_tok_cache; | |
2403 | ||
2404 | int | |
2405 | ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
84814d64 | 2406 | char *sig, u32 global_auth_tok_flags) |
f4aad16a MH |
2407 | { |
2408 | struct ecryptfs_global_auth_tok *new_auth_tok; | |
2409 | int rc = 0; | |
2410 | ||
459e2164 | 2411 | new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache, |
f4aad16a MH |
2412 | GFP_KERNEL); |
2413 | if (!new_auth_tok) { | |
2414 | rc = -ENOMEM; | |
2415 | printk(KERN_ERR "Error allocating from " | |
2416 | "ecryptfs_global_auth_tok_cache\n"); | |
2417 | goto out; | |
2418 | } | |
2419 | memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX); | |
84814d64 | 2420 | new_auth_tok->flags = global_auth_tok_flags; |
f4aad16a MH |
2421 | new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
2422 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
2423 | list_add(&new_auth_tok->mount_crypt_stat_list, | |
2424 | &mount_crypt_stat->global_auth_tok_list); | |
2425 | mount_crypt_stat->num_global_auth_toks++; | |
2426 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
2427 | out: | |
2428 | return rc; | |
2429 | } | |
2430 |