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