Commit | Line | Data |
---|---|---|
1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
ffbed072 | 2 | /* |
237fead6 MH |
3 | * eCryptfs: Linux filesystem encryption layer |
4 | * In-kernel key management code. Includes functions to parse and | |
5 | * write authentication token-related packets with the underlying | |
6 | * file. | |
7 | * | |
8 | * Copyright (C) 2004-2006 International Business Machines Corp. | |
9 | * Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com> | |
10 | * Michael C. Thompson <mcthomps@us.ibm.com> | |
dddfa461 | 11 | * Trevor S. Highland <trevor.highland@gmail.com> |
237fead6 MH |
12 | */ |
13 | ||
3095e8e3 HX |
14 | #include <crypto/hash.h> |
15 | #include <crypto/skcipher.h> | |
237fead6 | 16 | #include <linux/string.h> |
237fead6 MH |
17 | #include <linux/pagemap.h> |
18 | #include <linux/key.h> | |
19 | #include <linux/random.h> | |
237fead6 | 20 | #include <linux/scatterlist.h> |
5a0e3ad6 | 21 | #include <linux/slab.h> |
237fead6 MH |
22 | #include "ecryptfs_kernel.h" |
23 | ||
ffbed072 | 24 | /* |
237fead6 MH |
25 | * request_key returned an error instead of a valid key address; |
26 | * determine the type of error, make appropriate log entries, and | |
27 | * return an error code. | |
28 | */ | |
cd9d67df | 29 | static int process_request_key_err(long err_code) |
237fead6 MH |
30 | { |
31 | int rc = 0; | |
32 | ||
33 | switch (err_code) { | |
982363c9 | 34 | case -ENOKEY: |
237fead6 MH |
35 | ecryptfs_printk(KERN_WARNING, "No key\n"); |
36 | rc = -ENOENT; | |
37 | break; | |
982363c9 | 38 | case -EKEYEXPIRED: |
237fead6 MH |
39 | ecryptfs_printk(KERN_WARNING, "Key expired\n"); |
40 | rc = -ETIME; | |
41 | break; | |
982363c9 | 42 | case -EKEYREVOKED: |
237fead6 MH |
43 | ecryptfs_printk(KERN_WARNING, "Key revoked\n"); |
44 | rc = -EINVAL; | |
45 | break; | |
46 | default: | |
47 | ecryptfs_printk(KERN_WARNING, "Unknown error code: " | |
888d57bb | 48 | "[0x%.16lx]\n", err_code); |
237fead6 MH |
49 | rc = -EINVAL; |
50 | } | |
51 | return rc; | |
52 | } | |
53 | ||
0e1fc5ef RS |
54 | static int process_find_global_auth_tok_for_sig_err(int err_code) |
55 | { | |
56 | int rc = err_code; | |
57 | ||
58 | switch (err_code) { | |
59 | case -ENOENT: | |
60 | ecryptfs_printk(KERN_WARNING, "Missing auth tok\n"); | |
61 | break; | |
62 | case -EINVAL: | |
63 | ecryptfs_printk(KERN_WARNING, "Invalid auth tok\n"); | |
64 | break; | |
65 | default: | |
66 | rc = process_request_key_err(err_code); | |
67 | break; | |
68 | } | |
69 | return rc; | |
70 | } | |
71 | ||
237fead6 | 72 | /** |
f66e883e | 73 | * ecryptfs_parse_packet_length |
237fead6 MH |
74 | * @data: Pointer to memory containing length at offset |
75 | * @size: This function writes the decoded size to this memory | |
76 | * address; zero on error | |
77 | * @length_size: The number of bytes occupied by the encoded length | |
78 | * | |
22e78faf | 79 | * Returns zero on success; non-zero on error |
237fead6 | 80 | */ |
f66e883e MH |
81 | int ecryptfs_parse_packet_length(unsigned char *data, size_t *size, |
82 | size_t *length_size) | |
237fead6 MH |
83 | { |
84 | int rc = 0; | |
85 | ||
86 | (*length_size) = 0; | |
87 | (*size) = 0; | |
88 | if (data[0] < 192) { | |
89 | /* One-byte length */ | |
831115af | 90 | (*size) = data[0]; |
237fead6 MH |
91 | (*length_size) = 1; |
92 | } else if (data[0] < 224) { | |
93 | /* Two-byte length */ | |
831115af TH |
94 | (*size) = (data[0] - 192) * 256; |
95 | (*size) += data[1] + 192; | |
237fead6 MH |
96 | (*length_size) = 2; |
97 | } else if (data[0] == 255) { | |
48399c0b | 98 | /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */ |
237fead6 MH |
99 | ecryptfs_printk(KERN_ERR, "Five-byte packet length not " |
100 | "supported\n"); | |
101 | rc = -EINVAL; | |
102 | goto out; | |
103 | } else { | |
104 | ecryptfs_printk(KERN_ERR, "Error parsing packet length\n"); | |
105 | rc = -EINVAL; | |
106 | goto out; | |
107 | } | |
108 | out: | |
109 | return rc; | |
110 | } | |
111 | ||
112 | /** | |
f66e883e | 113 | * ecryptfs_write_packet_length |
22e78faf | 114 | * @dest: The byte array target into which to write the length. Must |
48399c0b | 115 | * have at least ECRYPTFS_MAX_PKT_LEN_SIZE bytes allocated. |
237fead6 | 116 | * @size: The length to write. |
22e78faf MH |
117 | * @packet_size_length: The number of bytes used to encode the packet |
118 | * length is written to this address. | |
237fead6 MH |
119 | * |
120 | * Returns zero on success; non-zero on error. | |
121 | */ | |
f66e883e MH |
122 | int ecryptfs_write_packet_length(char *dest, size_t size, |
123 | size_t *packet_size_length) | |
237fead6 MH |
124 | { |
125 | int rc = 0; | |
126 | ||
127 | if (size < 192) { | |
128 | dest[0] = size; | |
129 | (*packet_size_length) = 1; | |
130 | } else if (size < 65536) { | |
131 | dest[0] = (((size - 192) / 256) + 192); | |
132 | dest[1] = ((size - 192) % 256); | |
133 | (*packet_size_length) = 2; | |
134 | } else { | |
48399c0b | 135 | /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */ |
237fead6 MH |
136 | rc = -EINVAL; |
137 | ecryptfs_printk(KERN_WARNING, | |
f24b3887 | 138 | "Unsupported packet size: [%zd]\n", size); |
237fead6 MH |
139 | } |
140 | return rc; | |
141 | } | |
142 | ||
dddfa461 MH |
143 | static int |
144 | write_tag_64_packet(char *signature, struct ecryptfs_session_key *session_key, | |
145 | char **packet, size_t *packet_len) | |
146 | { | |
147 | size_t i = 0; | |
148 | size_t data_len; | |
149 | size_t packet_size_len; | |
150 | char *message; | |
151 | int rc; | |
152 | ||
153 | /* | |
154 | * ***** TAG 64 Packet Format ***** | |
155 | * | Content Type | 1 byte | | |
156 | * | Key Identifier Size | 1 or 2 bytes | | |
157 | * | Key Identifier | arbitrary | | |
158 | * | Encrypted File Encryption Key Size | 1 or 2 bytes | | |
159 | * | Encrypted File Encryption Key | arbitrary | | |
160 | */ | |
161 | data_len = (5 + ECRYPTFS_SIG_SIZE_HEX | |
162 | + session_key->encrypted_key_size); | |
163 | *packet = kmalloc(data_len, GFP_KERNEL); | |
164 | message = *packet; | |
165 | if (!message) { | |
166 | ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n"); | |
167 | rc = -ENOMEM; | |
168 | goto out; | |
169 | } | |
170 | message[i++] = ECRYPTFS_TAG_64_PACKET_TYPE; | |
f66e883e MH |
171 | rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX, |
172 | &packet_size_len); | |
dddfa461 MH |
173 | if (rc) { |
174 | ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet " | |
175 | "header; cannot generate packet length\n"); | |
176 | goto out; | |
177 | } | |
178 | i += packet_size_len; | |
179 | memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX); | |
180 | i += ECRYPTFS_SIG_SIZE_HEX; | |
f66e883e MH |
181 | rc = ecryptfs_write_packet_length(&message[i], |
182 | session_key->encrypted_key_size, | |
183 | &packet_size_len); | |
dddfa461 MH |
184 | if (rc) { |
185 | ecryptfs_printk(KERN_ERR, "Error generating tag 64 packet " | |
186 | "header; cannot generate packet length\n"); | |
187 | goto out; | |
188 | } | |
189 | i += packet_size_len; | |
190 | memcpy(&message[i], session_key->encrypted_key, | |
191 | session_key->encrypted_key_size); | |
192 | i += session_key->encrypted_key_size; | |
193 | *packet_len = i; | |
194 | out: | |
195 | return rc; | |
196 | } | |
197 | ||
198 | static int | |
19e66a67 | 199 | parse_tag_65_packet(struct ecryptfs_session_key *session_key, u8 *cipher_code, |
dddfa461 MH |
200 | struct ecryptfs_message *msg) |
201 | { | |
202 | size_t i = 0; | |
203 | char *data; | |
204 | size_t data_len; | |
205 | size_t m_size; | |
206 | size_t message_len; | |
207 | u16 checksum = 0; | |
208 | u16 expected_checksum = 0; | |
209 | int rc; | |
210 | ||
211 | /* | |
212 | * ***** TAG 65 Packet Format ***** | |
213 | * | Content Type | 1 byte | | |
214 | * | Status Indicator | 1 byte | | |
215 | * | File Encryption Key Size | 1 or 2 bytes | | |
216 | * | File Encryption Key | arbitrary | | |
217 | */ | |
218 | message_len = msg->data_len; | |
219 | data = msg->data; | |
220 | if (message_len < 4) { | |
221 | rc = -EIO; | |
222 | goto out; | |
223 | } | |
224 | if (data[i++] != ECRYPTFS_TAG_65_PACKET_TYPE) { | |
225 | ecryptfs_printk(KERN_ERR, "Type should be ECRYPTFS_TAG_65\n"); | |
226 | rc = -EIO; | |
227 | goto out; | |
228 | } | |
229 | if (data[i++]) { | |
230 | ecryptfs_printk(KERN_ERR, "Status indicator has non-zero value " | |
231 | "[%d]\n", data[i-1]); | |
232 | rc = -EIO; | |
233 | goto out; | |
234 | } | |
f66e883e | 235 | rc = ecryptfs_parse_packet_length(&data[i], &m_size, &data_len); |
dddfa461 MH |
236 | if (rc) { |
237 | ecryptfs_printk(KERN_WARNING, "Error parsing packet length; " | |
238 | "rc = [%d]\n", rc); | |
239 | goto out; | |
240 | } | |
241 | i += data_len; | |
242 | if (message_len < (i + m_size)) { | |
624ae528 TH |
243 | ecryptfs_printk(KERN_ERR, "The message received from ecryptfsd " |
244 | "is shorter than expected\n"); | |
dddfa461 MH |
245 | rc = -EIO; |
246 | goto out; | |
247 | } | |
248 | if (m_size < 3) { | |
249 | ecryptfs_printk(KERN_ERR, | |
250 | "The decrypted key is not long enough to " | |
251 | "include a cipher code and checksum\n"); | |
252 | rc = -EIO; | |
253 | goto out; | |
254 | } | |
255 | *cipher_code = data[i++]; | |
256 | /* The decrypted key includes 1 byte cipher code and 2 byte checksum */ | |
257 | session_key->decrypted_key_size = m_size - 3; | |
258 | if (session_key->decrypted_key_size > ECRYPTFS_MAX_KEY_BYTES) { | |
259 | ecryptfs_printk(KERN_ERR, "key_size [%d] larger than " | |
260 | "the maximum key size [%d]\n", | |
261 | session_key->decrypted_key_size, | |
262 | ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES); | |
263 | rc = -EIO; | |
264 | goto out; | |
265 | } | |
266 | memcpy(session_key->decrypted_key, &data[i], | |
267 | session_key->decrypted_key_size); | |
268 | i += session_key->decrypted_key_size; | |
269 | expected_checksum += (unsigned char)(data[i++]) << 8; | |
270 | expected_checksum += (unsigned char)(data[i++]); | |
271 | for (i = 0; i < session_key->decrypted_key_size; i++) | |
272 | checksum += session_key->decrypted_key[i]; | |
273 | if (expected_checksum != checksum) { | |
274 | ecryptfs_printk(KERN_ERR, "Invalid checksum for file " | |
275 | "encryption key; expected [%x]; calculated " | |
276 | "[%x]\n", expected_checksum, checksum); | |
277 | rc = -EIO; | |
278 | } | |
279 | out: | |
280 | return rc; | |
281 | } | |
282 | ||
283 | ||
284 | static int | |
19e66a67 | 285 | write_tag_66_packet(char *signature, u8 cipher_code, |
dddfa461 MH |
286 | struct ecryptfs_crypt_stat *crypt_stat, char **packet, |
287 | size_t *packet_len) | |
288 | { | |
289 | size_t i = 0; | |
290 | size_t j; | |
291 | size_t data_len; | |
292 | size_t checksum = 0; | |
293 | size_t packet_size_len; | |
294 | char *message; | |
295 | int rc; | |
296 | ||
297 | /* | |
298 | * ***** TAG 66 Packet Format ***** | |
299 | * | Content Type | 1 byte | | |
300 | * | Key Identifier Size | 1 or 2 bytes | | |
301 | * | Key Identifier | arbitrary | | |
302 | * | File Encryption Key Size | 1 or 2 bytes | | |
303 | * | File Encryption Key | arbitrary | | |
304 | */ | |
305 | data_len = (5 + ECRYPTFS_SIG_SIZE_HEX + crypt_stat->key_size); | |
306 | *packet = kmalloc(data_len, GFP_KERNEL); | |
307 | message = *packet; | |
308 | if (!message) { | |
309 | ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n"); | |
310 | rc = -ENOMEM; | |
311 | goto out; | |
312 | } | |
313 | message[i++] = ECRYPTFS_TAG_66_PACKET_TYPE; | |
f66e883e MH |
314 | rc = ecryptfs_write_packet_length(&message[i], ECRYPTFS_SIG_SIZE_HEX, |
315 | &packet_size_len); | |
dddfa461 MH |
316 | if (rc) { |
317 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet " | |
318 | "header; cannot generate packet length\n"); | |
319 | goto out; | |
320 | } | |
321 | i += packet_size_len; | |
322 | memcpy(&message[i], signature, ECRYPTFS_SIG_SIZE_HEX); | |
323 | i += ECRYPTFS_SIG_SIZE_HEX; | |
324 | /* The encrypted key includes 1 byte cipher code and 2 byte checksum */ | |
f66e883e MH |
325 | rc = ecryptfs_write_packet_length(&message[i], crypt_stat->key_size + 3, |
326 | &packet_size_len); | |
dddfa461 MH |
327 | if (rc) { |
328 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet " | |
329 | "header; cannot generate packet length\n"); | |
330 | goto out; | |
331 | } | |
332 | i += packet_size_len; | |
333 | message[i++] = cipher_code; | |
334 | memcpy(&message[i], crypt_stat->key, crypt_stat->key_size); | |
335 | i += crypt_stat->key_size; | |
336 | for (j = 0; j < crypt_stat->key_size; j++) | |
337 | checksum += crypt_stat->key[j]; | |
338 | message[i++] = (checksum / 256) % 256; | |
339 | message[i++] = (checksum % 256); | |
340 | *packet_len = i; | |
341 | out: | |
342 | return rc; | |
343 | } | |
344 | ||
345 | static int | |
346 | parse_tag_67_packet(struct ecryptfs_key_record *key_rec, | |
347 | struct ecryptfs_message *msg) | |
348 | { | |
349 | size_t i = 0; | |
350 | char *data; | |
351 | size_t data_len; | |
352 | size_t message_len; | |
353 | int rc; | |
354 | ||
355 | /* | |
356 | * ***** TAG 65 Packet Format ***** | |
357 | * | Content Type | 1 byte | | |
358 | * | Status Indicator | 1 byte | | |
359 | * | Encrypted File Encryption Key Size | 1 or 2 bytes | | |
360 | * | Encrypted File Encryption Key | arbitrary | | |
361 | */ | |
362 | message_len = msg->data_len; | |
363 | data = msg->data; | |
364 | /* verify that everything through the encrypted FEK size is present */ | |
365 | if (message_len < 4) { | |
366 | rc = -EIO; | |
df261c52 | 367 | printk(KERN_ERR "%s: message_len is [%zd]; minimum acceptable " |
f66e883e | 368 | "message length is [%d]\n", __func__, message_len, 4); |
dddfa461 MH |
369 | goto out; |
370 | } | |
371 | if (data[i++] != ECRYPTFS_TAG_67_PACKET_TYPE) { | |
dddfa461 | 372 | rc = -EIO; |
f66e883e MH |
373 | printk(KERN_ERR "%s: Type should be ECRYPTFS_TAG_67\n", |
374 | __func__); | |
dddfa461 MH |
375 | goto out; |
376 | } | |
377 | if (data[i++]) { | |
dddfa461 | 378 | rc = -EIO; |
f66e883e MH |
379 | printk(KERN_ERR "%s: Status indicator has non zero " |
380 | "value [%d]\n", __func__, data[i-1]); | |
381 | ||
dddfa461 MH |
382 | goto out; |
383 | } | |
f66e883e MH |
384 | rc = ecryptfs_parse_packet_length(&data[i], &key_rec->enc_key_size, |
385 | &data_len); | |
dddfa461 MH |
386 | if (rc) { |
387 | ecryptfs_printk(KERN_WARNING, "Error parsing packet length; " | |
388 | "rc = [%d]\n", rc); | |
389 | goto out; | |
390 | } | |
391 | i += data_len; | |
392 | if (message_len < (i + key_rec->enc_key_size)) { | |
dddfa461 | 393 | rc = -EIO; |
df261c52 | 394 | printk(KERN_ERR "%s: message_len [%zd]; max len is [%zd]\n", |
f66e883e | 395 | __func__, message_len, (i + key_rec->enc_key_size)); |
dddfa461 MH |
396 | goto out; |
397 | } | |
398 | if (key_rec->enc_key_size > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
dddfa461 | 399 | rc = -EIO; |
df261c52 | 400 | printk(KERN_ERR "%s: Encrypted key_size [%zd] larger than " |
f66e883e MH |
401 | "the maximum key size [%d]\n", __func__, |
402 | key_rec->enc_key_size, | |
403 | ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES); | |
dddfa461 MH |
404 | goto out; |
405 | } | |
406 | memcpy(key_rec->enc_key, &data[i], key_rec->enc_key_size); | |
407 | out: | |
408 | return rc; | |
409 | } | |
410 | ||
0e1fc5ef RS |
411 | /** |
412 | * ecryptfs_verify_version | |
413 | * @version: The version number to confirm | |
414 | * | |
415 | * Returns zero on good version; non-zero otherwise | |
416 | */ | |
417 | static int ecryptfs_verify_version(u16 version) | |
418 | { | |
419 | int rc = 0; | |
420 | unsigned char major; | |
421 | unsigned char minor; | |
422 | ||
423 | major = ((version >> 8) & 0xFF); | |
424 | minor = (version & 0xFF); | |
425 | if (major != ECRYPTFS_VERSION_MAJOR) { | |
426 | ecryptfs_printk(KERN_ERR, "Major version number mismatch. " | |
427 | "Expected [%d]; got [%d]\n", | |
428 | ECRYPTFS_VERSION_MAJOR, major); | |
429 | rc = -EINVAL; | |
430 | goto out; | |
431 | } | |
432 | if (minor != ECRYPTFS_VERSION_MINOR) { | |
433 | ecryptfs_printk(KERN_ERR, "Minor version number mismatch. " | |
434 | "Expected [%d]; got [%d]\n", | |
435 | ECRYPTFS_VERSION_MINOR, minor); | |
436 | rc = -EINVAL; | |
437 | goto out; | |
438 | } | |
439 | out: | |
440 | return rc; | |
441 | } | |
442 | ||
443 | /** | |
444 | * ecryptfs_verify_auth_tok_from_key | |
445 | * @auth_tok_key: key containing the authentication token | |
446 | * @auth_tok: authentication token | |
447 | * | |
f66665c0 EB |
448 | * Returns zero on valid auth tok; -EINVAL if the payload is invalid; or |
449 | * -EKEYREVOKED if the key was revoked before we acquired its semaphore. | |
0e1fc5ef RS |
450 | */ |
451 | static int | |
452 | ecryptfs_verify_auth_tok_from_key(struct key *auth_tok_key, | |
453 | struct ecryptfs_auth_tok **auth_tok) | |
454 | { | |
455 | int rc = 0; | |
456 | ||
457 | (*auth_tok) = ecryptfs_get_key_payload_data(auth_tok_key); | |
f66665c0 EB |
458 | if (IS_ERR(*auth_tok)) { |
459 | rc = PTR_ERR(*auth_tok); | |
460 | *auth_tok = NULL; | |
461 | goto out; | |
462 | } | |
463 | ||
0e1fc5ef RS |
464 | if (ecryptfs_verify_version((*auth_tok)->version)) { |
465 | printk(KERN_ERR "Data structure version mismatch. Userspace " | |
466 | "tools must match eCryptfs kernel module with major " | |
467 | "version [%d] and minor version [%d]\n", | |
468 | ECRYPTFS_VERSION_MAJOR, ECRYPTFS_VERSION_MINOR); | |
469 | rc = -EINVAL; | |
470 | goto out; | |
471 | } | |
472 | if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD | |
473 | && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) { | |
474 | printk(KERN_ERR "Invalid auth_tok structure " | |
475 | "returned from key query\n"); | |
476 | rc = -EINVAL; | |
477 | goto out; | |
478 | } | |
479 | out: | |
480 | return rc; | |
481 | } | |
482 | ||
9c79f34f MH |
483 | static int |
484 | ecryptfs_find_global_auth_tok_for_sig( | |
0e1fc5ef RS |
485 | struct key **auth_tok_key, |
486 | struct ecryptfs_auth_tok **auth_tok, | |
9c79f34f MH |
487 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig) |
488 | { | |
489 | struct ecryptfs_global_auth_tok *walker; | |
490 | int rc = 0; | |
491 | ||
0e1fc5ef RS |
492 | (*auth_tok_key) = NULL; |
493 | (*auth_tok) = NULL; | |
9c79f34f MH |
494 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); |
495 | list_for_each_entry(walker, | |
496 | &mount_crypt_stat->global_auth_tok_list, | |
497 | mount_crypt_stat_list) { | |
0e1fc5ef RS |
498 | if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX)) |
499 | continue; | |
500 | ||
501 | if (walker->flags & ECRYPTFS_AUTH_TOK_INVALID) { | |
502 | rc = -EINVAL; | |
9c79f34f MH |
503 | goto out; |
504 | } | |
0e1fc5ef RS |
505 | |
506 | rc = key_validate(walker->global_auth_tok_key); | |
507 | if (rc) { | |
508 | if (rc == -EKEYEXPIRED) | |
509 | goto out; | |
510 | goto out_invalid_auth_tok; | |
511 | } | |
512 | ||
b5695d04 | 513 | down_write(&(walker->global_auth_tok_key->sem)); |
0e1fc5ef RS |
514 | rc = ecryptfs_verify_auth_tok_from_key( |
515 | walker->global_auth_tok_key, auth_tok); | |
516 | if (rc) | |
b5695d04 | 517 | goto out_invalid_auth_tok_unlock; |
0e1fc5ef RS |
518 | |
519 | (*auth_tok_key) = walker->global_auth_tok_key; | |
520 | key_get(*auth_tok_key); | |
521 | goto out; | |
9c79f34f | 522 | } |
0e1fc5ef RS |
523 | rc = -ENOENT; |
524 | goto out; | |
b5695d04 RS |
525 | out_invalid_auth_tok_unlock: |
526 | up_write(&(walker->global_auth_tok_key->sem)); | |
0e1fc5ef RS |
527 | out_invalid_auth_tok: |
528 | printk(KERN_WARNING "Invalidating auth tok with sig = [%s]\n", sig); | |
529 | walker->flags |= ECRYPTFS_AUTH_TOK_INVALID; | |
530 | key_put(walker->global_auth_tok_key); | |
531 | walker->global_auth_tok_key = NULL; | |
9c79f34f MH |
532 | out: |
533 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
534 | return rc; | |
535 | } | |
536 | ||
537 | /** | |
538 | * ecryptfs_find_auth_tok_for_sig | |
ffbed072 | 539 | * @auth_tok_key: key containing the authentication token |
9c79f34f | 540 | * @auth_tok: Set to the matching auth_tok; NULL if not found |
ffbed072 | 541 | * @mount_crypt_stat: inode crypt_stat crypto context |
9c79f34f MH |
542 | * @sig: Sig of auth_tok to find |
543 | * | |
544 | * For now, this function simply looks at the registered auth_tok's | |
545 | * linked off the mount_crypt_stat, so all the auth_toks that can be | |
546 | * used must be registered at mount time. This function could | |
547 | * potentially try a lot harder to find auth_tok's (e.g., by calling | |
548 | * out to ecryptfsd to dynamically retrieve an auth_tok object) so | |
549 | * that static registration of auth_tok's will no longer be necessary. | |
550 | * | |
551 | * Returns zero on no error; non-zero on error | |
552 | */ | |
553 | static int | |
554 | ecryptfs_find_auth_tok_for_sig( | |
aee683b9 | 555 | struct key **auth_tok_key, |
9c79f34f MH |
556 | struct ecryptfs_auth_tok **auth_tok, |
557 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
558 | char *sig) | |
559 | { | |
9c79f34f MH |
560 | int rc = 0; |
561 | ||
0e1fc5ef RS |
562 | rc = ecryptfs_find_global_auth_tok_for_sig(auth_tok_key, auth_tok, |
563 | mount_crypt_stat, sig); | |
564 | if (rc == -ENOENT) { | |
f16feb51 RS |
565 | /* if the flag ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY is set in the |
566 | * mount_crypt_stat structure, we prevent to use auth toks that | |
567 | * are not inserted through the ecryptfs_add_global_auth_tok | |
568 | * function. | |
569 | */ | |
570 | if (mount_crypt_stat->flags | |
571 | & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY) | |
572 | return -EINVAL; | |
573 | ||
aee683b9 | 574 | rc = ecryptfs_keyring_auth_tok_for_sig(auth_tok_key, auth_tok, |
9c79f34f | 575 | sig); |
0e1fc5ef | 576 | } |
9c79f34f MH |
577 | return rc; |
578 | } | |
579 | ||
ffbed072 | 580 | /* |
9c79f34f MH |
581 | * write_tag_70_packet can gobble a lot of stack space. We stuff most |
582 | * of the function's parameters in a kmalloc'd struct to help reduce | |
583 | * eCryptfs' overall stack usage. | |
584 | */ | |
585 | struct ecryptfs_write_tag_70_packet_silly_stack { | |
586 | u8 cipher_code; | |
587 | size_t max_packet_size; | |
588 | size_t packet_size_len; | |
589 | size_t block_aligned_filename_size; | |
590 | size_t block_size; | |
591 | size_t i; | |
592 | size_t j; | |
593 | size_t num_rand_bytes; | |
594 | struct mutex *tfm_mutex; | |
595 | char *block_aligned_filename; | |
596 | struct ecryptfs_auth_tok *auth_tok; | |
8d08dab7 TH |
597 | struct scatterlist src_sg[2]; |
598 | struct scatterlist dst_sg[2]; | |
3095e8e3 HX |
599 | struct crypto_skcipher *skcipher_tfm; |
600 | struct skcipher_request *skcipher_req; | |
9c79f34f MH |
601 | char iv[ECRYPTFS_MAX_IV_BYTES]; |
602 | char hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; | |
603 | char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; | |
3095e8e3 HX |
604 | struct crypto_shash *hash_tfm; |
605 | struct shash_desc *hash_desc; | |
9c79f34f MH |
606 | }; |
607 | ||
ffbed072 | 608 | /* |
9c79f34f MH |
609 | * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK |
610 | * @filename: NULL-terminated filename string | |
611 | * | |
612 | * This is the simplest mechanism for achieving filename encryption in | |
613 | * eCryptfs. It encrypts the given filename with the mount-wide | |
614 | * filename encryption key (FNEK) and stores it in a packet to @dest, | |
615 | * which the callee will encode and write directly into the dentry | |
616 | * name. | |
617 | */ | |
618 | int | |
619 | ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, | |
620 | size_t *packet_size, | |
621 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
622 | char *filename, size_t filename_size) | |
623 | { | |
624 | struct ecryptfs_write_tag_70_packet_silly_stack *s; | |
aee683b9 | 625 | struct key *auth_tok_key = NULL; |
9c79f34f MH |
626 | int rc = 0; |
627 | ||
3095e8e3 | 628 | s = kzalloc(sizeof(*s), GFP_KERNEL); |
1a0bba4f | 629 | if (!s) |
d1558f4e | 630 | return -ENOMEM; |
1a0bba4f | 631 | |
9c79f34f | 632 | (*packet_size) = 0; |
950983fc RS |
633 | rc = ecryptfs_find_auth_tok_for_sig( |
634 | &auth_tok_key, | |
635 | &s->auth_tok, mount_crypt_stat, | |
636 | mount_crypt_stat->global_default_fnek_sig); | |
637 | if (rc) { | |
638 | printk(KERN_ERR "%s: Error attempting to find auth tok for " | |
639 | "fnek sig [%s]; rc = [%d]\n", __func__, | |
640 | mount_crypt_stat->global_default_fnek_sig, rc); | |
641 | goto out; | |
642 | } | |
9c79f34f | 643 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name( |
3095e8e3 | 644 | &s->skcipher_tfm, |
9c79f34f MH |
645 | &s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name); |
646 | if (unlikely(rc)) { | |
647 | printk(KERN_ERR "Internal error whilst attempting to get " | |
648 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
649 | mount_crypt_stat->global_default_fn_cipher_name, rc); | |
650 | goto out; | |
651 | } | |
652 | mutex_lock(s->tfm_mutex); | |
3095e8e3 | 653 | s->block_size = crypto_skcipher_blocksize(s->skcipher_tfm); |
9c79f34f MH |
654 | /* Plus one for the \0 separator between the random prefix |
655 | * and the plaintext filename */ | |
656 | s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1); | |
657 | s->block_aligned_filename_size = (s->num_rand_bytes + filename_size); | |
658 | if ((s->block_aligned_filename_size % s->block_size) != 0) { | |
659 | s->num_rand_bytes += (s->block_size | |
660 | - (s->block_aligned_filename_size | |
661 | % s->block_size)); | |
662 | s->block_aligned_filename_size = (s->num_rand_bytes | |
663 | + filename_size); | |
664 | } | |
665 | /* Octet 0: Tag 70 identifier | |
666 | * Octets 1-N1: Tag 70 packet size (includes cipher identifier | |
667 | * and block-aligned encrypted filename size) | |
668 | * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) | |
669 | * Octet N2-N3: Cipher identifier (1 octet) | |
670 | * Octets N3-N4: Block-aligned encrypted filename | |
671 | * - Consists of a minimum number of random characters, a \0 | |
672 | * separator, and then the filename */ | |
4a26620d | 673 | s->max_packet_size = (ECRYPTFS_TAG_70_MAX_METADATA_SIZE |
9c79f34f | 674 | + s->block_aligned_filename_size); |
5032f360 | 675 | if (!dest) { |
9c79f34f MH |
676 | (*packet_size) = s->max_packet_size; |
677 | goto out_unlock; | |
678 | } | |
679 | if (s->max_packet_size > (*remaining_bytes)) { | |
a8f12864 MH |
680 | printk(KERN_WARNING "%s: Require [%zd] bytes to write; only " |
681 | "[%zd] available\n", __func__, s->max_packet_size, | |
9c79f34f MH |
682 | (*remaining_bytes)); |
683 | rc = -EINVAL; | |
684 | goto out_unlock; | |
685 | } | |
3095e8e3 HX |
686 | |
687 | s->skcipher_req = skcipher_request_alloc(s->skcipher_tfm, GFP_KERNEL); | |
688 | if (!s->skcipher_req) { | |
689 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " | |
690 | "skcipher_request_alloc for %s\n", __func__, | |
691 | crypto_skcipher_driver_name(s->skcipher_tfm)); | |
692 | rc = -ENOMEM; | |
693 | goto out_unlock; | |
694 | } | |
695 | ||
696 | skcipher_request_set_callback(s->skcipher_req, | |
697 | CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL); | |
698 | ||
9c79f34f MH |
699 | s->block_aligned_filename = kzalloc(s->block_aligned_filename_size, |
700 | GFP_KERNEL); | |
701 | if (!s->block_aligned_filename) { | |
9c79f34f MH |
702 | rc = -ENOMEM; |
703 | goto out_unlock; | |
704 | } | |
9c79f34f MH |
705 | dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE; |
706 | rc = ecryptfs_write_packet_length(&dest[s->i], | |
707 | (ECRYPTFS_SIG_SIZE | |
708 | + 1 /* Cipher code */ | |
709 | + s->block_aligned_filename_size), | |
710 | &s->packet_size_len); | |
711 | if (rc) { | |
712 | printk(KERN_ERR "%s: Error generating tag 70 packet " | |
713 | "header; cannot generate packet length; rc = [%d]\n", | |
714 | __func__, rc); | |
715 | goto out_free_unlock; | |
716 | } | |
717 | s->i += s->packet_size_len; | |
718 | ecryptfs_from_hex(&dest[s->i], | |
719 | mount_crypt_stat->global_default_fnek_sig, | |
720 | ECRYPTFS_SIG_SIZE); | |
721 | s->i += ECRYPTFS_SIG_SIZE; | |
722 | s->cipher_code = ecryptfs_code_for_cipher_string( | |
723 | mount_crypt_stat->global_default_fn_cipher_name, | |
724 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
725 | if (s->cipher_code == 0) { | |
726 | printk(KERN_WARNING "%s: Unable to generate code for " | |
a8f12864 | 727 | "cipher [%s] with key bytes [%zd]\n", __func__, |
9c79f34f MH |
728 | mount_crypt_stat->global_default_fn_cipher_name, |
729 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
730 | rc = -EINVAL; | |
731 | goto out_free_unlock; | |
732 | } | |
733 | dest[s->i++] = s->cipher_code; | |
9c79f34f MH |
734 | /* TODO: Support other key modules than passphrase for |
735 | * filename encryption */ | |
df6ad33b TH |
736 | if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) { |
737 | rc = -EOPNOTSUPP; | |
738 | printk(KERN_INFO "%s: Filename encryption only supports " | |
739 | "password tokens\n", __func__); | |
740 | goto out_free_unlock; | |
741 | } | |
3095e8e3 HX |
742 | s->hash_tfm = crypto_alloc_shash(ECRYPTFS_TAG_70_DIGEST, 0, 0); |
743 | if (IS_ERR(s->hash_tfm)) { | |
744 | rc = PTR_ERR(s->hash_tfm); | |
9c79f34f MH |
745 | printk(KERN_ERR "%s: Error attempting to " |
746 | "allocate hash crypto context; rc = [%d]\n", | |
747 | __func__, rc); | |
748 | goto out_free_unlock; | |
749 | } | |
3095e8e3 HX |
750 | |
751 | s->hash_desc = kmalloc(sizeof(*s->hash_desc) + | |
752 | crypto_shash_descsize(s->hash_tfm), GFP_KERNEL); | |
753 | if (!s->hash_desc) { | |
3095e8e3 | 754 | rc = -ENOMEM; |
9c79f34f MH |
755 | goto out_release_free_unlock; |
756 | } | |
3095e8e3 HX |
757 | |
758 | s->hash_desc->tfm = s->hash_tfm; | |
3095e8e3 HX |
759 | |
760 | rc = crypto_shash_digest(s->hash_desc, | |
761 | (u8 *)s->auth_tok->token.password.session_key_encryption_key, | |
762 | s->auth_tok->token.password.session_key_encryption_key_bytes, | |
763 | s->hash); | |
9c79f34f MH |
764 | if (rc) { |
765 | printk(KERN_ERR | |
3095e8e3 | 766 | "%s: Error computing crypto hash; rc = [%d]\n", |
9c79f34f MH |
767 | __func__, rc); |
768 | goto out_release_free_unlock; | |
769 | } | |
770 | for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) { | |
771 | s->block_aligned_filename[s->j] = | |
772 | s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)]; | |
773 | if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE) | |
774 | == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) { | |
3095e8e3 HX |
775 | rc = crypto_shash_digest(s->hash_desc, (u8 *)s->hash, |
776 | ECRYPTFS_TAG_70_DIGEST_SIZE, | |
777 | s->tmp_hash); | |
9c79f34f MH |
778 | if (rc) { |
779 | printk(KERN_ERR | |
3095e8e3 | 780 | "%s: Error computing crypto hash; " |
9c79f34f MH |
781 | "rc = [%d]\n", __func__, rc); |
782 | goto out_release_free_unlock; | |
783 | } | |
784 | memcpy(s->hash, s->tmp_hash, | |
785 | ECRYPTFS_TAG_70_DIGEST_SIZE); | |
786 | } | |
787 | if (s->block_aligned_filename[s->j] == '\0') | |
788 | s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL; | |
789 | } | |
790 | memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename, | |
791 | filename_size); | |
792 | rc = virt_to_scatterlist(s->block_aligned_filename, | |
8d08dab7 TH |
793 | s->block_aligned_filename_size, s->src_sg, 2); |
794 | if (rc < 1) { | |
9c79f34f | 795 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
8d08dab7 | 796 | "convert filename memory to scatterlist; rc = [%d]. " |
a8f12864 | 797 | "block_aligned_filename_size = [%zd]\n", __func__, rc, |
9c79f34f MH |
798 | s->block_aligned_filename_size); |
799 | goto out_release_free_unlock; | |
800 | } | |
801 | rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size, | |
8d08dab7 TH |
802 | s->dst_sg, 2); |
803 | if (rc < 1) { | |
9c79f34f MH |
804 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
805 | "convert encrypted filename memory to scatterlist; " | |
8d08dab7 TH |
806 | "rc = [%d]. block_aligned_filename_size = [%zd]\n", |
807 | __func__, rc, s->block_aligned_filename_size); | |
9c79f34f MH |
808 | goto out_release_free_unlock; |
809 | } | |
810 | /* The characters in the first block effectively do the job | |
811 | * of the IV here, so we just use 0's for the IV. Note the | |
812 | * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES | |
813 | * >= ECRYPTFS_MAX_IV_BYTES. */ | |
3095e8e3 HX |
814 | rc = crypto_skcipher_setkey( |
815 | s->skcipher_tfm, | |
9c79f34f MH |
816 | s->auth_tok->token.password.session_key_encryption_key, |
817 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
818 | if (rc < 0) { | |
819 | printk(KERN_ERR "%s: Error setting key for crypto context; " | |
820 | "rc = [%d]. s->auth_tok->token.password.session_key_" | |
821 | "encryption_key = [0x%p]; mount_crypt_stat->" | |
df261c52 | 822 | "global_default_fn_cipher_key_bytes = [%zd]\n", __func__, |
9c79f34f MH |
823 | rc, |
824 | s->auth_tok->token.password.session_key_encryption_key, | |
825 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
826 | goto out_release_free_unlock; | |
827 | } | |
3095e8e3 HX |
828 | skcipher_request_set_crypt(s->skcipher_req, s->src_sg, s->dst_sg, |
829 | s->block_aligned_filename_size, s->iv); | |
830 | rc = crypto_skcipher_encrypt(s->skcipher_req); | |
9c79f34f MH |
831 | if (rc) { |
832 | printk(KERN_ERR "%s: Error attempting to encrypt filename; " | |
833 | "rc = [%d]\n", __func__, rc); | |
834 | goto out_release_free_unlock; | |
835 | } | |
836 | s->i += s->block_aligned_filename_size; | |
837 | (*packet_size) = s->i; | |
838 | (*remaining_bytes) -= (*packet_size); | |
839 | out_release_free_unlock: | |
3095e8e3 | 840 | crypto_free_shash(s->hash_tfm); |
9c79f34f | 841 | out_free_unlock: |
453431a5 | 842 | kfree_sensitive(s->block_aligned_filename); |
9c79f34f MH |
843 | out_unlock: |
844 | mutex_unlock(s->tfm_mutex); | |
845 | out: | |
b5695d04 RS |
846 | if (auth_tok_key) { |
847 | up_write(&(auth_tok_key->sem)); | |
aee683b9 | 848 | key_put(auth_tok_key); |
b5695d04 | 849 | } |
3095e8e3 | 850 | skcipher_request_free(s->skcipher_req); |
453431a5 | 851 | kfree_sensitive(s->hash_desc); |
9c79f34f MH |
852 | kfree(s); |
853 | return rc; | |
854 | } | |
855 | ||
856 | struct ecryptfs_parse_tag_70_packet_silly_stack { | |
857 | u8 cipher_code; | |
858 | size_t max_packet_size; | |
859 | size_t packet_size_len; | |
860 | size_t parsed_tag_70_packet_size; | |
861 | size_t block_aligned_filename_size; | |
862 | size_t block_size; | |
863 | size_t i; | |
864 | struct mutex *tfm_mutex; | |
865 | char *decrypted_filename; | |
866 | struct ecryptfs_auth_tok *auth_tok; | |
8d08dab7 TH |
867 | struct scatterlist src_sg[2]; |
868 | struct scatterlist dst_sg[2]; | |
3095e8e3 HX |
869 | struct crypto_skcipher *skcipher_tfm; |
870 | struct skcipher_request *skcipher_req; | |
9c79f34f MH |
871 | char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1]; |
872 | char iv[ECRYPTFS_MAX_IV_BYTES]; | |
2a559a8b | 873 | char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1]; |
9c79f34f MH |
874 | }; |
875 | ||
876 | /** | |
ffbed072 | 877 | * ecryptfs_parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet |
9c79f34f | 878 | * @filename: This function kmalloc's the memory for the filename |
7d8bc2be MH |
879 | * @filename_size: This function sets this to the amount of memory |
880 | * kmalloc'd for the filename | |
881 | * @packet_size: This function sets this to the the number of octets | |
882 | * in the packet parsed | |
883 | * @mount_crypt_stat: The mount-wide cryptographic context | |
884 | * @data: The memory location containing the start of the tag 70 | |
885 | * packet | |
886 | * @max_packet_size: The maximum legal size of the packet to be parsed | |
887 | * from @data | |
888 | * | |
889 | * Returns zero on success; non-zero otherwise | |
9c79f34f MH |
890 | */ |
891 | int | |
892 | ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, | |
893 | size_t *packet_size, | |
894 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
895 | char *data, size_t max_packet_size) | |
896 | { | |
897 | struct ecryptfs_parse_tag_70_packet_silly_stack *s; | |
aee683b9 | 898 | struct key *auth_tok_key = NULL; |
9c79f34f MH |
899 | int rc = 0; |
900 | ||
901 | (*packet_size) = 0; | |
902 | (*filename_size) = 0; | |
903 | (*filename) = NULL; | |
3095e8e3 | 904 | s = kzalloc(sizeof(*s), GFP_KERNEL); |
1a0bba4f | 905 | if (!s) |
d1558f4e | 906 | return -ENOMEM; |
1a0bba4f | 907 | |
4a26620d | 908 | if (max_packet_size < ECRYPTFS_TAG_70_MIN_METADATA_SIZE) { |
df261c52 | 909 | printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be " |
9c79f34f | 910 | "at least [%d]\n", __func__, max_packet_size, |
4a26620d | 911 | ECRYPTFS_TAG_70_MIN_METADATA_SIZE); |
9c79f34f MH |
912 | rc = -EINVAL; |
913 | goto out; | |
914 | } | |
915 | /* Octet 0: Tag 70 identifier | |
916 | * Octets 1-N1: Tag 70 packet size (includes cipher identifier | |
917 | * and block-aligned encrypted filename size) | |
918 | * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) | |
919 | * Octet N2-N3: Cipher identifier (1 octet) | |
920 | * Octets N3-N4: Block-aligned encrypted filename | |
921 | * - Consists of a minimum number of random numbers, a \0 | |
922 | * separator, and then the filename */ | |
923 | if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) { | |
924 | printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be " | |
925 | "tag [0x%.2x]\n", __func__, | |
926 | data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE); | |
927 | rc = -EINVAL; | |
928 | goto out; | |
929 | } | |
930 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], | |
931 | &s->parsed_tag_70_packet_size, | |
932 | &s->packet_size_len); | |
933 | if (rc) { | |
934 | printk(KERN_WARNING "%s: Error parsing packet length; " | |
935 | "rc = [%d]\n", __func__, rc); | |
936 | goto out; | |
937 | } | |
938 | s->block_aligned_filename_size = (s->parsed_tag_70_packet_size | |
939 | - ECRYPTFS_SIG_SIZE - 1); | |
940 | if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size) | |
941 | > max_packet_size) { | |
a8f12864 MH |
942 | printk(KERN_WARNING "%s: max_packet_size is [%zd]; real packet " |
943 | "size is [%zd]\n", __func__, max_packet_size, | |
9c79f34f MH |
944 | (1 + s->packet_size_len + 1 |
945 | + s->block_aligned_filename_size)); | |
946 | rc = -EINVAL; | |
947 | goto out; | |
948 | } | |
949 | (*packet_size) += s->packet_size_len; | |
950 | ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)], | |
951 | ECRYPTFS_SIG_SIZE); | |
952 | s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0'; | |
953 | (*packet_size) += ECRYPTFS_SIG_SIZE; | |
954 | s->cipher_code = data[(*packet_size)++]; | |
955 | rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code); | |
956 | if (rc) { | |
957 | printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n", | |
958 | __func__, s->cipher_code); | |
959 | goto out; | |
960 | } | |
950983fc RS |
961 | rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key, |
962 | &s->auth_tok, mount_crypt_stat, | |
963 | s->fnek_sig_hex); | |
964 | if (rc) { | |
965 | printk(KERN_ERR "%s: Error attempting to find auth tok for " | |
966 | "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex, | |
967 | rc); | |
968 | goto out; | |
969 | } | |
3095e8e3 | 970 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->skcipher_tfm, |
9c79f34f MH |
971 | &s->tfm_mutex, |
972 | s->cipher_string); | |
973 | if (unlikely(rc)) { | |
974 | printk(KERN_ERR "Internal error whilst attempting to get " | |
975 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
976 | s->cipher_string, rc); | |
977 | goto out; | |
978 | } | |
979 | mutex_lock(s->tfm_mutex); | |
980 | rc = virt_to_scatterlist(&data[(*packet_size)], | |
8d08dab7 TH |
981 | s->block_aligned_filename_size, s->src_sg, 2); |
982 | if (rc < 1) { | |
9c79f34f MH |
983 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
984 | "convert encrypted filename memory to scatterlist; " | |
8d08dab7 TH |
985 | "rc = [%d]. block_aligned_filename_size = [%zd]\n", |
986 | __func__, rc, s->block_aligned_filename_size); | |
9c79f34f MH |
987 | goto out_unlock; |
988 | } | |
989 | (*packet_size) += s->block_aligned_filename_size; | |
990 | s->decrypted_filename = kmalloc(s->block_aligned_filename_size, | |
991 | GFP_KERNEL); | |
992 | if (!s->decrypted_filename) { | |
9c79f34f MH |
993 | rc = -ENOMEM; |
994 | goto out_unlock; | |
995 | } | |
996 | rc = virt_to_scatterlist(s->decrypted_filename, | |
8d08dab7 TH |
997 | s->block_aligned_filename_size, s->dst_sg, 2); |
998 | if (rc < 1) { | |
9c79f34f MH |
999 | printk(KERN_ERR "%s: Internal error whilst attempting to " |
1000 | "convert decrypted filename memory to scatterlist; " | |
8d08dab7 TH |
1001 | "rc = [%d]. block_aligned_filename_size = [%zd]\n", |
1002 | __func__, rc, s->block_aligned_filename_size); | |
9c79f34f MH |
1003 | goto out_free_unlock; |
1004 | } | |
3095e8e3 HX |
1005 | |
1006 | s->skcipher_req = skcipher_request_alloc(s->skcipher_tfm, GFP_KERNEL); | |
1007 | if (!s->skcipher_req) { | |
1008 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " | |
1009 | "skcipher_request_alloc for %s\n", __func__, | |
1010 | crypto_skcipher_driver_name(s->skcipher_tfm)); | |
1011 | rc = -ENOMEM; | |
1012 | goto out_free_unlock; | |
1013 | } | |
1014 | ||
1015 | skcipher_request_set_callback(s->skcipher_req, | |
1016 | CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL); | |
1017 | ||
9c79f34f MH |
1018 | /* The characters in the first block effectively do the job of |
1019 | * the IV here, so we just use 0's for the IV. Note the | |
1020 | * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES | |
1021 | * >= ECRYPTFS_MAX_IV_BYTES. */ | |
9c79f34f MH |
1022 | /* TODO: Support other key modules than passphrase for |
1023 | * filename encryption */ | |
df6ad33b TH |
1024 | if (s->auth_tok->token_type != ECRYPTFS_PASSWORD) { |
1025 | rc = -EOPNOTSUPP; | |
1026 | printk(KERN_INFO "%s: Filename encryption only supports " | |
1027 | "password tokens\n", __func__); | |
1028 | goto out_free_unlock; | |
1029 | } | |
3095e8e3 HX |
1030 | rc = crypto_skcipher_setkey( |
1031 | s->skcipher_tfm, | |
9c79f34f MH |
1032 | s->auth_tok->token.password.session_key_encryption_key, |
1033 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
1034 | if (rc < 0) { | |
1035 | printk(KERN_ERR "%s: Error setting key for crypto context; " | |
1036 | "rc = [%d]. s->auth_tok->token.password.session_key_" | |
1037 | "encryption_key = [0x%p]; mount_crypt_stat->" | |
df261c52 | 1038 | "global_default_fn_cipher_key_bytes = [%zd]\n", __func__, |
9c79f34f MH |
1039 | rc, |
1040 | s->auth_tok->token.password.session_key_encryption_key, | |
1041 | mount_crypt_stat->global_default_fn_cipher_key_bytes); | |
1042 | goto out_free_unlock; | |
1043 | } | |
3095e8e3 HX |
1044 | skcipher_request_set_crypt(s->skcipher_req, s->src_sg, s->dst_sg, |
1045 | s->block_aligned_filename_size, s->iv); | |
1046 | rc = crypto_skcipher_decrypt(s->skcipher_req); | |
9c79f34f MH |
1047 | if (rc) { |
1048 | printk(KERN_ERR "%s: Error attempting to decrypt filename; " | |
1049 | "rc = [%d]\n", __func__, rc); | |
1050 | goto out_free_unlock; | |
1051 | } | |
4b47a8b5 DC |
1052 | |
1053 | while (s->i < s->block_aligned_filename_size && | |
1054 | s->decrypted_filename[s->i] != '\0') | |
9c79f34f MH |
1055 | s->i++; |
1056 | if (s->i == s->block_aligned_filename_size) { | |
1057 | printk(KERN_WARNING "%s: Invalid tag 70 packet; could not " | |
1058 | "find valid separator between random characters and " | |
1059 | "the filename\n", __func__); | |
1060 | rc = -EINVAL; | |
1061 | goto out_free_unlock; | |
1062 | } | |
1063 | s->i++; | |
1064 | (*filename_size) = (s->block_aligned_filename_size - s->i); | |
1065 | if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) { | |
df261c52 | 1066 | printk(KERN_WARNING "%s: Filename size is [%zd], which is " |
9c79f34f MH |
1067 | "invalid\n", __func__, (*filename_size)); |
1068 | rc = -EINVAL; | |
1069 | goto out_free_unlock; | |
1070 | } | |
1071 | (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL); | |
1072 | if (!(*filename)) { | |
9c79f34f MH |
1073 | rc = -ENOMEM; |
1074 | goto out_free_unlock; | |
1075 | } | |
1076 | memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size)); | |
1077 | (*filename)[(*filename_size)] = '\0'; | |
1078 | out_free_unlock: | |
1079 | kfree(s->decrypted_filename); | |
1080 | out_unlock: | |
1081 | mutex_unlock(s->tfm_mutex); | |
1082 | out: | |
1083 | if (rc) { | |
1084 | (*packet_size) = 0; | |
1085 | (*filename_size) = 0; | |
1086 | (*filename) = NULL; | |
1087 | } | |
b5695d04 RS |
1088 | if (auth_tok_key) { |
1089 | up_write(&(auth_tok_key->sem)); | |
aee683b9 | 1090 | key_put(auth_tok_key); |
b5695d04 | 1091 | } |
3095e8e3 | 1092 | skcipher_request_free(s->skcipher_req); |
9c79f34f MH |
1093 | kfree(s); |
1094 | return rc; | |
1095 | } | |
1096 | ||
cd9d67df MH |
1097 | static int |
1098 | ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok) | |
1099 | { | |
1100 | int rc = 0; | |
1101 | ||
1102 | (*sig) = NULL; | |
1103 | switch (auth_tok->token_type) { | |
1104 | case ECRYPTFS_PASSWORD: | |
1105 | (*sig) = auth_tok->token.password.signature; | |
1106 | break; | |
1107 | case ECRYPTFS_PRIVATE_KEY: | |
1108 | (*sig) = auth_tok->token.private_key.signature; | |
1109 | break; | |
1110 | default: | |
1111 | printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n", | |
1112 | auth_tok->token_type); | |
1113 | rc = -EINVAL; | |
1114 | } | |
1115 | return rc; | |
1116 | } | |
1117 | ||
dddfa461 | 1118 | /** |
22e78faf MH |
1119 | * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok. |
1120 | * @auth_tok: The key authentication token used to decrypt the session key | |
1121 | * @crypt_stat: The cryptographic context | |
dddfa461 | 1122 | * |
22e78faf | 1123 | * Returns zero on success; non-zero error otherwise. |
dddfa461 | 1124 | */ |
f4aad16a MH |
1125 | static int |
1126 | decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, | |
1127 | struct ecryptfs_crypt_stat *crypt_stat) | |
dddfa461 | 1128 | { |
19e66a67 | 1129 | u8 cipher_code = 0; |
dddfa461 MH |
1130 | struct ecryptfs_msg_ctx *msg_ctx; |
1131 | struct ecryptfs_message *msg = NULL; | |
f4aad16a | 1132 | char *auth_tok_sig; |
3edc8376 | 1133 | char *payload = NULL; |
fa519964 | 1134 | size_t payload_len = 0; |
dddfa461 MH |
1135 | int rc; |
1136 | ||
5dda6992 MH |
1137 | rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok); |
1138 | if (rc) { | |
f4aad16a MH |
1139 | printk(KERN_ERR "Unrecognized auth tok type: [%d]\n", |
1140 | auth_tok->token_type); | |
1141 | goto out; | |
1142 | } | |
1143 | rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key), | |
624ae528 | 1144 | &payload, &payload_len); |
dddfa461 | 1145 | if (rc) { |
f66e883e | 1146 | ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet\n"); |
dddfa461 MH |
1147 | goto out; |
1148 | } | |
624ae528 | 1149 | rc = ecryptfs_send_message(payload, payload_len, &msg_ctx); |
dddfa461 | 1150 | if (rc) { |
624ae528 | 1151 | ecryptfs_printk(KERN_ERR, "Error sending message to " |
290502be | 1152 | "ecryptfsd: %d\n", rc); |
dddfa461 MH |
1153 | goto out; |
1154 | } | |
1155 | rc = ecryptfs_wait_for_response(msg_ctx, &msg); | |
1156 | if (rc) { | |
1157 | ecryptfs_printk(KERN_ERR, "Failed to receive tag 65 packet " | |
1158 | "from the user space daemon\n"); | |
1159 | rc = -EIO; | |
1160 | goto out; | |
1161 | } | |
1162 | rc = parse_tag_65_packet(&(auth_tok->session_key), | |
1163 | &cipher_code, msg); | |
1164 | if (rc) { | |
1165 | printk(KERN_ERR "Failed to parse tag 65 packet; rc = [%d]\n", | |
1166 | rc); | |
1167 | goto out; | |
1168 | } | |
1169 | auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1170 | memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, | |
1171 | auth_tok->session_key.decrypted_key_size); | |
1172 | crypt_stat->key_size = auth_tok->session_key.decrypted_key_size; | |
1173 | rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, cipher_code); | |
1174 | if (rc) { | |
1175 | ecryptfs_printk(KERN_ERR, "Cipher code [%d] is invalid\n", | |
d0eb2d86 | 1176 | cipher_code); |
dddfa461 MH |
1177 | goto out; |
1178 | } | |
1179 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; | |
1180 | if (ecryptfs_verbosity > 0) { | |
1181 | ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n"); | |
1182 | ecryptfs_dump_hex(crypt_stat->key, | |
1183 | crypt_stat->key_size); | |
1184 | } | |
1185 | out: | |
3a467418 | 1186 | kfree(msg); |
3edc8376 | 1187 | kfree(payload); |
dddfa461 MH |
1188 | return rc; |
1189 | } | |
1190 | ||
1191 | static void wipe_auth_tok_list(struct list_head *auth_tok_list_head) | |
1192 | { | |
dddfa461 | 1193 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
e0869cc1 | 1194 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
dddfa461 | 1195 | |
e0869cc1 MH |
1196 | list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp, |
1197 | auth_tok_list_head, list) { | |
1198 | list_del(&auth_tok_list_item->list); | |
dddfa461 MH |
1199 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, |
1200 | auth_tok_list_item); | |
1201 | } | |
dddfa461 MH |
1202 | } |
1203 | ||
1204 | struct kmem_cache *ecryptfs_auth_tok_list_item_cache; | |
1205 | ||
dddfa461 MH |
1206 | /** |
1207 | * parse_tag_1_packet | |
22e78faf | 1208 | * @crypt_stat: The cryptographic context to modify based on packet contents |
dddfa461 MH |
1209 | * @data: The raw bytes of the packet. |
1210 | * @auth_tok_list: eCryptfs parses packets into authentication tokens; | |
22e78faf MH |
1211 | * a new authentication token will be placed at the |
1212 | * end of this list for this packet. | |
dddfa461 MH |
1213 | * @new_auth_tok: Pointer to a pointer to memory that this function |
1214 | * allocates; sets the memory address of the pointer to | |
1215 | * NULL on error. This object is added to the | |
1216 | * auth_tok_list. | |
1217 | * @packet_size: This function writes the size of the parsed packet | |
1218 | * into this memory location; zero on error. | |
22e78faf | 1219 | * @max_packet_size: The maximum allowable packet size |
dddfa461 MH |
1220 | * |
1221 | * Returns zero on success; non-zero on error. | |
1222 | */ | |
1223 | static int | |
1224 | parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat, | |
1225 | unsigned char *data, struct list_head *auth_tok_list, | |
1226 | struct ecryptfs_auth_tok **new_auth_tok, | |
1227 | size_t *packet_size, size_t max_packet_size) | |
1228 | { | |
1229 | size_t body_size; | |
1230 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; | |
1231 | size_t length_size; | |
1232 | int rc = 0; | |
1233 | ||
1234 | (*packet_size) = 0; | |
1235 | (*new_auth_tok) = NULL; | |
13218179 MH |
1236 | /** |
1237 | * This format is inspired by OpenPGP; see RFC 2440 | |
1238 | * packet tag 1 | |
1239 | * | |
1240 | * Tag 1 identifier (1 byte) | |
1241 | * Max Tag 1 packet size (max 3 bytes) | |
1242 | * Version (1 byte) | |
1243 | * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE) | |
1244 | * Cipher identifier (1 byte) | |
1245 | * Encrypted key size (arbitrary) | |
1246 | * | |
1247 | * 12 bytes minimum packet size | |
dddfa461 | 1248 | */ |
13218179 MH |
1249 | if (unlikely(max_packet_size < 12)) { |
1250 | printk(KERN_ERR "Invalid max packet size; must be >=12\n"); | |
dddfa461 MH |
1251 | rc = -EINVAL; |
1252 | goto out; | |
1253 | } | |
dddfa461 | 1254 | if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) { |
13218179 MH |
1255 | printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n", |
1256 | ECRYPTFS_TAG_1_PACKET_TYPE); | |
dddfa461 MH |
1257 | rc = -EINVAL; |
1258 | goto out; | |
1259 | } | |
1260 | /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or | |
1261 | * at end of function upon failure */ | |
1262 | auth_tok_list_item = | |
13218179 MH |
1263 | kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, |
1264 | GFP_KERNEL); | |
dddfa461 | 1265 | if (!auth_tok_list_item) { |
13218179 | 1266 | printk(KERN_ERR "Unable to allocate memory\n"); |
dddfa461 MH |
1267 | rc = -ENOMEM; |
1268 | goto out; | |
1269 | } | |
dddfa461 | 1270 | (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
f66e883e MH |
1271 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1272 | &length_size); | |
5dda6992 | 1273 | if (rc) { |
13218179 MH |
1274 | printk(KERN_WARNING "Error parsing packet length; " |
1275 | "rc = [%d]\n", rc); | |
dddfa461 MH |
1276 | goto out_free; |
1277 | } | |
13218179 | 1278 | if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) { |
81acbcd6 | 1279 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
dddfa461 MH |
1280 | rc = -EINVAL; |
1281 | goto out_free; | |
1282 | } | |
1283 | (*packet_size) += length_size; | |
1284 | if (unlikely((*packet_size) + body_size > max_packet_size)) { | |
13218179 | 1285 | printk(KERN_WARNING "Packet size exceeds max\n"); |
dddfa461 MH |
1286 | rc = -EINVAL; |
1287 | goto out_free; | |
1288 | } | |
dddfa461 | 1289 | if (unlikely(data[(*packet_size)++] != 0x03)) { |
13218179 MH |
1290 | printk(KERN_WARNING "Unknown version number [%d]\n", |
1291 | data[(*packet_size) - 1]); | |
dddfa461 MH |
1292 | rc = -EINVAL; |
1293 | goto out_free; | |
1294 | } | |
dddfa461 MH |
1295 | ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature, |
1296 | &data[(*packet_size)], ECRYPTFS_SIG_SIZE); | |
1297 | *packet_size += ECRYPTFS_SIG_SIZE; | |
1298 | /* This byte is skipped because the kernel does not need to | |
1299 | * know which public key encryption algorithm was used */ | |
1300 | (*packet_size)++; | |
1301 | (*new_auth_tok)->session_key.encrypted_key_size = | |
13218179 | 1302 | body_size - (ECRYPTFS_SIG_SIZE + 2); |
dddfa461 MH |
1303 | if ((*new_auth_tok)->session_key.encrypted_key_size |
1304 | > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
13218179 | 1305 | printk(KERN_WARNING "Tag 1 packet contains key larger " |
0996b67d | 1306 | "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n"); |
dddfa461 | 1307 | rc = -EINVAL; |
fe2e082f | 1308 | goto out_free; |
dddfa461 | 1309 | } |
dddfa461 | 1310 | memcpy((*new_auth_tok)->session_key.encrypted_key, |
13218179 | 1311 | &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2))); |
dddfa461 MH |
1312 | (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size; |
1313 | (*new_auth_tok)->session_key.flags &= | |
1314 | ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1315 | (*new_auth_tok)->session_key.flags |= | |
1316 | ECRYPTFS_CONTAINS_ENCRYPTED_KEY; | |
1317 | (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY; | |
13218179 | 1318 | (*new_auth_tok)->flags = 0; |
e2bd99ec MH |
1319 | (*new_auth_tok)->session_key.flags &= |
1320 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT); | |
1321 | (*new_auth_tok)->session_key.flags &= | |
1322 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT); | |
dddfa461 MH |
1323 | list_add(&auth_tok_list_item->list, auth_tok_list); |
1324 | goto out; | |
1325 | out_free: | |
1326 | (*new_auth_tok) = NULL; | |
1327 | memset(auth_tok_list_item, 0, | |
1328 | sizeof(struct ecryptfs_auth_tok_list_item)); | |
1329 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, | |
1330 | auth_tok_list_item); | |
1331 | out: | |
1332 | if (rc) | |
1333 | (*packet_size) = 0; | |
1334 | return rc; | |
1335 | } | |
1336 | ||
237fead6 MH |
1337 | /** |
1338 | * parse_tag_3_packet | |
1339 | * @crypt_stat: The cryptographic context to modify based on packet | |
1340 | * contents. | |
1341 | * @data: The raw bytes of the packet. | |
1342 | * @auth_tok_list: eCryptfs parses packets into authentication tokens; | |
1343 | * a new authentication token will be placed at the end | |
1344 | * of this list for this packet. | |
1345 | * @new_auth_tok: Pointer to a pointer to memory that this function | |
1346 | * allocates; sets the memory address of the pointer to | |
1347 | * NULL on error. This object is added to the | |
1348 | * auth_tok_list. | |
1349 | * @packet_size: This function writes the size of the parsed packet | |
1350 | * into this memory location; zero on error. | |
1351 | * @max_packet_size: maximum number of bytes to parse | |
1352 | * | |
1353 | * Returns zero on success; non-zero on error. | |
1354 | */ | |
1355 | static int | |
1356 | parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat, | |
1357 | unsigned char *data, struct list_head *auth_tok_list, | |
1358 | struct ecryptfs_auth_tok **new_auth_tok, | |
1359 | size_t *packet_size, size_t max_packet_size) | |
1360 | { | |
237fead6 MH |
1361 | size_t body_size; |
1362 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; | |
1363 | size_t length_size; | |
dddfa461 | 1364 | int rc = 0; |
237fead6 MH |
1365 | |
1366 | (*packet_size) = 0; | |
1367 | (*new_auth_tok) = NULL; | |
c59becfc MH |
1368 | /** |
1369 | *This format is inspired by OpenPGP; see RFC 2440 | |
1370 | * packet tag 3 | |
1371 | * | |
1372 | * Tag 3 identifier (1 byte) | |
1373 | * Max Tag 3 packet size (max 3 bytes) | |
1374 | * Version (1 byte) | |
1375 | * Cipher code (1 byte) | |
1376 | * S2K specifier (1 byte) | |
1377 | * Hash identifier (1 byte) | |
1378 | * Salt (ECRYPTFS_SALT_SIZE) | |
1379 | * Hash iterations (1 byte) | |
1380 | * Encrypted key (arbitrary) | |
1381 | * | |
1382 | * (ECRYPTFS_SALT_SIZE + 7) minimum packet size | |
237fead6 | 1383 | */ |
c59becfc MH |
1384 | if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) { |
1385 | printk(KERN_ERR "Max packet size too large\n"); | |
237fead6 MH |
1386 | rc = -EINVAL; |
1387 | goto out; | |
1388 | } | |
237fead6 | 1389 | if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) { |
c59becfc MH |
1390 | printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n", |
1391 | ECRYPTFS_TAG_3_PACKET_TYPE); | |
237fead6 MH |
1392 | rc = -EINVAL; |
1393 | goto out; | |
1394 | } | |
1395 | /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or | |
1396 | * at end of function upon failure */ | |
1397 | auth_tok_list_item = | |
c3762229 | 1398 | kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL); |
237fead6 | 1399 | if (!auth_tok_list_item) { |
c59becfc | 1400 | printk(KERN_ERR "Unable to allocate memory\n"); |
237fead6 MH |
1401 | rc = -ENOMEM; |
1402 | goto out; | |
1403 | } | |
237fead6 | 1404 | (*new_auth_tok) = &auth_tok_list_item->auth_tok; |
f66e883e MH |
1405 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1406 | &length_size); | |
5dda6992 | 1407 | if (rc) { |
c59becfc MH |
1408 | printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n", |
1409 | rc); | |
237fead6 MH |
1410 | goto out_free; |
1411 | } | |
c59becfc | 1412 | if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) { |
81acbcd6 | 1413 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
237fead6 MH |
1414 | rc = -EINVAL; |
1415 | goto out_free; | |
1416 | } | |
1417 | (*packet_size) += length_size; | |
237fead6 | 1418 | if (unlikely((*packet_size) + body_size > max_packet_size)) { |
c59becfc | 1419 | printk(KERN_ERR "Packet size exceeds max\n"); |
237fead6 MH |
1420 | rc = -EINVAL; |
1421 | goto out_free; | |
1422 | } | |
237fead6 | 1423 | (*new_auth_tok)->session_key.encrypted_key_size = |
c59becfc | 1424 | (body_size - (ECRYPTFS_SALT_SIZE + 5)); |
f151cd2c RCV |
1425 | if ((*new_auth_tok)->session_key.encrypted_key_size |
1426 | > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { | |
1427 | printk(KERN_WARNING "Tag 3 packet contains key larger " | |
1428 | "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n"); | |
1429 | rc = -EINVAL; | |
1430 | goto out_free; | |
1431 | } | |
237fead6 | 1432 | if (unlikely(data[(*packet_size)++] != 0x04)) { |
c59becfc MH |
1433 | printk(KERN_WARNING "Unknown version number [%d]\n", |
1434 | data[(*packet_size) - 1]); | |
237fead6 MH |
1435 | rc = -EINVAL; |
1436 | goto out_free; | |
1437 | } | |
b0105eae TH |
1438 | rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher, |
1439 | (u16)data[(*packet_size)]); | |
1440 | if (rc) | |
1441 | goto out_free; | |
237fead6 MH |
1442 | /* A little extra work to differentiate among the AES key |
1443 | * sizes; see RFC2440 */ | |
1444 | switch(data[(*packet_size)++]) { | |
1445 | case RFC2440_CIPHER_AES_192: | |
1446 | crypt_stat->key_size = 24; | |
1447 | break; | |
1448 | default: | |
1449 | crypt_stat->key_size = | |
1450 | (*new_auth_tok)->session_key.encrypted_key_size; | |
1451 | } | |
b0105eae TH |
1452 | rc = ecryptfs_init_crypt_ctx(crypt_stat); |
1453 | if (rc) | |
1454 | goto out_free; | |
237fead6 | 1455 | if (unlikely(data[(*packet_size)++] != 0x03)) { |
c59becfc | 1456 | printk(KERN_WARNING "Only S2K ID 3 is currently supported\n"); |
237fead6 MH |
1457 | rc = -ENOSYS; |
1458 | goto out_free; | |
1459 | } | |
237fead6 | 1460 | /* TODO: finish the hash mapping */ |
237fead6 MH |
1461 | switch (data[(*packet_size)++]) { |
1462 | case 0x01: /* See RFC2440 for these numbers and their mappings */ | |
1463 | /* Choose MD5 */ | |
237fead6 MH |
1464 | memcpy((*new_auth_tok)->token.password.salt, |
1465 | &data[(*packet_size)], ECRYPTFS_SALT_SIZE); | |
1466 | (*packet_size) += ECRYPTFS_SALT_SIZE; | |
237fead6 | 1467 | /* This conversion was taken straight from RFC2440 */ |
237fead6 MH |
1468 | (*new_auth_tok)->token.password.hash_iterations = |
1469 | ((u32) 16 + (data[(*packet_size)] & 15)) | |
1470 | << ((data[(*packet_size)] >> 4) + 6); | |
1471 | (*packet_size)++; | |
c59becfc MH |
1472 | /* Friendly reminder: |
1473 | * (*new_auth_tok)->session_key.encrypted_key_size = | |
1474 | * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */ | |
237fead6 MH |
1475 | memcpy((*new_auth_tok)->session_key.encrypted_key, |
1476 | &data[(*packet_size)], | |
1477 | (*new_auth_tok)->session_key.encrypted_key_size); | |
1478 | (*packet_size) += | |
1479 | (*new_auth_tok)->session_key.encrypted_key_size; | |
1480 | (*new_auth_tok)->session_key.flags &= | |
1481 | ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; | |
1482 | (*new_auth_tok)->session_key.flags |= | |
1483 | ECRYPTFS_CONTAINS_ENCRYPTED_KEY; | |
c59becfc | 1484 | (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */ |
237fead6 MH |
1485 | break; |
1486 | default: | |
1487 | ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: " | |
1488 | "[%d]\n", data[(*packet_size) - 1]); | |
1489 | rc = -ENOSYS; | |
1490 | goto out_free; | |
1491 | } | |
1492 | (*new_auth_tok)->token_type = ECRYPTFS_PASSWORD; | |
1493 | /* TODO: Parametarize; we might actually want userspace to | |
1494 | * decrypt the session key. */ | |
e2bd99ec MH |
1495 | (*new_auth_tok)->session_key.flags &= |
1496 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT); | |
1497 | (*new_auth_tok)->session_key.flags &= | |
1498 | ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT); | |
237fead6 MH |
1499 | list_add(&auth_tok_list_item->list, auth_tok_list); |
1500 | goto out; | |
1501 | out_free: | |
1502 | (*new_auth_tok) = NULL; | |
1503 | memset(auth_tok_list_item, 0, | |
1504 | sizeof(struct ecryptfs_auth_tok_list_item)); | |
1505 | kmem_cache_free(ecryptfs_auth_tok_list_item_cache, | |
1506 | auth_tok_list_item); | |
1507 | out: | |
1508 | if (rc) | |
1509 | (*packet_size) = 0; | |
1510 | return rc; | |
1511 | } | |
1512 | ||
1513 | /** | |
1514 | * parse_tag_11_packet | |
1515 | * @data: The raw bytes of the packet | |
1516 | * @contents: This function writes the data contents of the literal | |
1517 | * packet into this memory location | |
1518 | * @max_contents_bytes: The maximum number of bytes that this function | |
1519 | * is allowed to write into contents | |
1520 | * @tag_11_contents_size: This function writes the size of the parsed | |
1521 | * contents into this memory location; zero on | |
1522 | * error | |
1523 | * @packet_size: This function writes the size of the parsed packet | |
1524 | * into this memory location; zero on error | |
1525 | * @max_packet_size: maximum number of bytes to parse | |
1526 | * | |
1527 | * Returns zero on success; non-zero on error. | |
1528 | */ | |
1529 | static int | |
1530 | parse_tag_11_packet(unsigned char *data, unsigned char *contents, | |
1531 | size_t max_contents_bytes, size_t *tag_11_contents_size, | |
1532 | size_t *packet_size, size_t max_packet_size) | |
1533 | { | |
237fead6 MH |
1534 | size_t body_size; |
1535 | size_t length_size; | |
dddfa461 | 1536 | int rc = 0; |
237fead6 MH |
1537 | |
1538 | (*packet_size) = 0; | |
1539 | (*tag_11_contents_size) = 0; | |
f648104a MH |
1540 | /* This format is inspired by OpenPGP; see RFC 2440 |
1541 | * packet tag 11 | |
1542 | * | |
1543 | * Tag 11 identifier (1 byte) | |
1544 | * Max Tag 11 packet size (max 3 bytes) | |
1545 | * Binary format specifier (1 byte) | |
1546 | * Filename length (1 byte) | |
1547 | * Filename ("_CONSOLE") (8 bytes) | |
1548 | * Modification date (4 bytes) | |
1549 | * Literal data (arbitrary) | |
1550 | * | |
1551 | * We need at least 16 bytes of data for the packet to even be | |
1552 | * valid. | |
237fead6 | 1553 | */ |
f648104a MH |
1554 | if (max_packet_size < 16) { |
1555 | printk(KERN_ERR "Maximum packet size too small\n"); | |
237fead6 MH |
1556 | rc = -EINVAL; |
1557 | goto out; | |
1558 | } | |
237fead6 | 1559 | if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) { |
f648104a | 1560 | printk(KERN_WARNING "Invalid tag 11 packet format\n"); |
237fead6 MH |
1561 | rc = -EINVAL; |
1562 | goto out; | |
1563 | } | |
f66e883e MH |
1564 | rc = ecryptfs_parse_packet_length(&data[(*packet_size)], &body_size, |
1565 | &length_size); | |
5dda6992 | 1566 | if (rc) { |
f648104a | 1567 | printk(KERN_WARNING "Invalid tag 11 packet format\n"); |
237fead6 MH |
1568 | goto out; |
1569 | } | |
f648104a | 1570 | if (body_size < 14) { |
81acbcd6 | 1571 | printk(KERN_WARNING "Invalid body size ([%td])\n", body_size); |
237fead6 MH |
1572 | rc = -EINVAL; |
1573 | goto out; | |
1574 | } | |
f648104a MH |
1575 | (*packet_size) += length_size; |
1576 | (*tag_11_contents_size) = (body_size - 14); | |
237fead6 | 1577 | if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) { |
f648104a | 1578 | printk(KERN_ERR "Packet size exceeds max\n"); |
237fead6 MH |
1579 | rc = -EINVAL; |
1580 | goto out; | |
1581 | } | |
6352a293 TH |
1582 | if (unlikely((*tag_11_contents_size) > max_contents_bytes)) { |
1583 | printk(KERN_ERR "Literal data section in tag 11 packet exceeds " | |
1584 | "expected size\n"); | |
1585 | rc = -EINVAL; | |
1586 | goto out; | |
1587 | } | |
237fead6 | 1588 | if (data[(*packet_size)++] != 0x62) { |
f648104a | 1589 | printk(KERN_WARNING "Unrecognizable packet\n"); |
237fead6 MH |
1590 | rc = -EINVAL; |
1591 | goto out; | |
1592 | } | |
237fead6 | 1593 | if (data[(*packet_size)++] != 0x08) { |
f648104a | 1594 | printk(KERN_WARNING "Unrecognizable packet\n"); |
237fead6 MH |
1595 | rc = -EINVAL; |
1596 | goto out; | |
1597 | } | |
f648104a | 1598 | (*packet_size) += 12; /* Ignore filename and modification date */ |
237fead6 MH |
1599 | memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size)); |
1600 | (*packet_size) += (*tag_11_contents_size); | |
237fead6 MH |
1601 | out: |
1602 | if (rc) { | |
1603 | (*packet_size) = 0; | |
1604 | (*tag_11_contents_size) = 0; | |
1605 | } | |
1606 | return rc; | |
1607 | } | |
1608 | ||
f4aad16a MH |
1609 | int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key, |
1610 | struct ecryptfs_auth_tok **auth_tok, | |
1611 | char *sig) | |
1612 | { | |
1613 | int rc = 0; | |
1614 | ||
028db3e2 | 1615 | (*auth_tok_key) = request_key(&key_type_user, sig, NULL); |
29a51df0 | 1616 | if (IS_ERR(*auth_tok_key)) { |
1252cc3b | 1617 | (*auth_tok_key) = ecryptfs_get_encrypted_key(sig); |
29a51df0 | 1618 | if (IS_ERR(*auth_tok_key)) { |
1252cc3b RS |
1619 | printk(KERN_ERR "Could not find key with description: [%s]\n", |
1620 | sig); | |
1621 | rc = process_request_key_err(PTR_ERR(*auth_tok_key)); | |
1622 | (*auth_tok_key) = NULL; | |
1623 | goto out; | |
1624 | } | |
f4aad16a | 1625 | } |
b5695d04 | 1626 | down_write(&(*auth_tok_key)->sem); |
0e1fc5ef | 1627 | rc = ecryptfs_verify_auth_tok_from_key(*auth_tok_key, auth_tok); |
aee683b9 | 1628 | if (rc) { |
b5695d04 | 1629 | up_write(&(*auth_tok_key)->sem); |
aee683b9 RS |
1630 | key_put(*auth_tok_key); |
1631 | (*auth_tok_key) = NULL; | |
0e1fc5ef | 1632 | goto out; |
f4aad16a MH |
1633 | } |
1634 | out: | |
1635 | return rc; | |
1636 | } | |
1637 | ||
f4aad16a | 1638 | /** |
22e78faf MH |
1639 | * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok. |
1640 | * @auth_tok: The passphrase authentication token to use to encrypt the FEK | |
1641 | * @crypt_stat: The cryptographic context | |
237fead6 | 1642 | * |
22e78faf | 1643 | * Returns zero on success; non-zero error otherwise |
237fead6 | 1644 | */ |
f4aad16a MH |
1645 | static int |
1646 | decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, | |
1647 | struct ecryptfs_crypt_stat *crypt_stat) | |
237fead6 | 1648 | { |
ac97b9f9 MH |
1649 | struct scatterlist dst_sg[2]; |
1650 | struct scatterlist src_sg[2]; | |
dd8e2902 | 1651 | struct mutex *tfm_mutex; |
3095e8e3 HX |
1652 | struct crypto_skcipher *tfm; |
1653 | struct skcipher_request *req = NULL; | |
8bba066f | 1654 | int rc = 0; |
237fead6 | 1655 | |
f4aad16a MH |
1656 | if (unlikely(ecryptfs_verbosity > 0)) { |
1657 | ecryptfs_printk( | |
1658 | KERN_DEBUG, "Session key encryption key (size [%d]):\n", | |
1659 | auth_tok->token.password.session_key_encryption_key_bytes); | |
1660 | ecryptfs_dump_hex( | |
1661 | auth_tok->token.password.session_key_encryption_key, | |
1662 | auth_tok->token.password.session_key_encryption_key_bytes); | |
1663 | } | |
3095e8e3 | 1664 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&tfm, &tfm_mutex, |
f4aad16a MH |
1665 | crypt_stat->cipher); |
1666 | if (unlikely(rc)) { | |
1667 | printk(KERN_ERR "Internal error whilst attempting to get " | |
1668 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
1669 | crypt_stat->cipher, rc); | |
1670 | goto out; | |
237fead6 | 1671 | } |
5dda6992 MH |
1672 | rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key, |
1673 | auth_tok->session_key.encrypted_key_size, | |
ac97b9f9 MH |
1674 | src_sg, 2); |
1675 | if (rc < 1 || rc > 2) { | |
f4aad16a MH |
1676 | printk(KERN_ERR "Internal error whilst attempting to convert " |
1677 | "auth_tok->session_key.encrypted_key to scatterlist; " | |
1678 | "expected rc = 1; got rc = [%d]. " | |
1679 | "auth_tok->session_key.encrypted_key_size = [%d]\n", rc, | |
1680 | auth_tok->session_key.encrypted_key_size); | |
1681 | goto out; | |
1682 | } | |
1683 | auth_tok->session_key.decrypted_key_size = | |
1684 | auth_tok->session_key.encrypted_key_size; | |
5dda6992 MH |
1685 | rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key, |
1686 | auth_tok->session_key.decrypted_key_size, | |
ac97b9f9 MH |
1687 | dst_sg, 2); |
1688 | if (rc < 1 || rc > 2) { | |
f4aad16a MH |
1689 | printk(KERN_ERR "Internal error whilst attempting to convert " |
1690 | "auth_tok->session_key.decrypted_key to scatterlist; " | |
1691 | "expected rc = 1; got rc = [%d]\n", rc); | |
1692 | goto out; | |
1693 | } | |
1694 | mutex_lock(tfm_mutex); | |
3095e8e3 HX |
1695 | req = skcipher_request_alloc(tfm, GFP_KERNEL); |
1696 | if (!req) { | |
1697 | mutex_unlock(tfm_mutex); | |
1698 | printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " | |
1699 | "skcipher_request_alloc for %s\n", __func__, | |
1700 | crypto_skcipher_driver_name(tfm)); | |
1701 | rc = -ENOMEM; | |
1702 | goto out; | |
1703 | } | |
1704 | ||
1705 | skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, | |
1706 | NULL, NULL); | |
1707 | rc = crypto_skcipher_setkey( | |
1708 | tfm, auth_tok->token.password.session_key_encryption_key, | |
f4aad16a MH |
1709 | crypt_stat->key_size); |
1710 | if (unlikely(rc < 0)) { | |
1711 | mutex_unlock(tfm_mutex); | |
e5d9cbde MH |
1712 | printk(KERN_ERR "Error setting key for crypto context\n"); |
1713 | rc = -EINVAL; | |
f4aad16a | 1714 | goto out; |
237fead6 | 1715 | } |
3095e8e3 HX |
1716 | skcipher_request_set_crypt(req, src_sg, dst_sg, |
1717 | auth_tok->session_key.encrypted_key_size, | |
1718 | NULL); | |
1719 | rc = crypto_skcipher_decrypt(req); | |
f4aad16a MH |
1720 | mutex_unlock(tfm_mutex); |
1721 | if (unlikely(rc)) { | |
8bba066f | 1722 | printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc); |
f4aad16a | 1723 | goto out; |
8bba066f | 1724 | } |
237fead6 MH |
1725 | auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; |
1726 | memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, | |
1727 | auth_tok->session_key.decrypted_key_size); | |
e2bd99ec | 1728 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; |
f4aad16a | 1729 | if (unlikely(ecryptfs_verbosity > 0)) { |
f24b3887 | 1730 | ecryptfs_printk(KERN_DEBUG, "FEK of size [%zd]:\n", |
f4aad16a | 1731 | crypt_stat->key_size); |
237fead6 MH |
1732 | ecryptfs_dump_hex(crypt_stat->key, |
1733 | crypt_stat->key_size); | |
f4aad16a | 1734 | } |
237fead6 | 1735 | out: |
3095e8e3 | 1736 | skcipher_request_free(req); |
237fead6 MH |
1737 | return rc; |
1738 | } | |
1739 | ||
1740 | /** | |
1741 | * ecryptfs_parse_packet_set | |
22e78faf MH |
1742 | * @crypt_stat: The cryptographic context |
1743 | * @src: Virtual address of region of memory containing the packets | |
1744 | * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set | |
237fead6 MH |
1745 | * |
1746 | * Get crypt_stat to have the file's session key if the requisite key | |
1747 | * is available to decrypt the session key. | |
1748 | * | |
1749 | * Returns Zero if a valid authentication token was retrieved and | |
1750 | * processed; negative value for file not encrypted or for error | |
1751 | * conditions. | |
1752 | */ | |
1753 | int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat, | |
1754 | unsigned char *src, | |
1755 | struct dentry *ecryptfs_dentry) | |
1756 | { | |
1757 | size_t i = 0; | |
f4aad16a | 1758 | size_t found_auth_tok; |
237fead6 | 1759 | size_t next_packet_is_auth_tok_packet; |
237fead6 | 1760 | struct list_head auth_tok_list; |
dd8e2902 MH |
1761 | struct ecryptfs_auth_tok *matching_auth_tok; |
1762 | struct ecryptfs_auth_tok *candidate_auth_tok; | |
f4aad16a | 1763 | char *candidate_auth_tok_sig; |
237fead6 MH |
1764 | size_t packet_size; |
1765 | struct ecryptfs_auth_tok *new_auth_tok; | |
1766 | unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE]; | |
f4aad16a | 1767 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item; |
237fead6 MH |
1768 | size_t tag_11_contents_size; |
1769 | size_t tag_11_packet_size; | |
aee683b9 | 1770 | struct key *auth_tok_key = NULL; |
dddfa461 | 1771 | int rc = 0; |
237fead6 MH |
1772 | |
1773 | INIT_LIST_HEAD(&auth_tok_list); | |
f4aad16a | 1774 | /* Parse the header to find as many packets as we can; these will be |
237fead6 MH |
1775 | * added the our &auth_tok_list */ |
1776 | next_packet_is_auth_tok_packet = 1; | |
1777 | while (next_packet_is_auth_tok_packet) { | |
09cbfeaf | 1778 | size_t max_packet_size = ((PAGE_SIZE - 8) - i); |
237fead6 MH |
1779 | |
1780 | switch (src[i]) { | |
1781 | case ECRYPTFS_TAG_3_PACKET_TYPE: | |
1782 | rc = parse_tag_3_packet(crypt_stat, | |
1783 | (unsigned char *)&src[i], | |
1784 | &auth_tok_list, &new_auth_tok, | |
1785 | &packet_size, max_packet_size); | |
1786 | if (rc) { | |
1787 | ecryptfs_printk(KERN_ERR, "Error parsing " | |
1788 | "tag 3 packet\n"); | |
1789 | rc = -EIO; | |
1790 | goto out_wipe_list; | |
1791 | } | |
1792 | i += packet_size; | |
1793 | rc = parse_tag_11_packet((unsigned char *)&src[i], | |
1794 | sig_tmp_space, | |
1795 | ECRYPTFS_SIG_SIZE, | |
1796 | &tag_11_contents_size, | |
1797 | &tag_11_packet_size, | |
1798 | max_packet_size); | |
1799 | if (rc) { | |
1800 | ecryptfs_printk(KERN_ERR, "No valid " | |
1801 | "(ecryptfs-specific) literal " | |
1802 | "packet containing " | |
1803 | "authentication token " | |
1804 | "signature found after " | |
1805 | "tag 3 packet\n"); | |
1806 | rc = -EIO; | |
1807 | goto out_wipe_list; | |
1808 | } | |
1809 | i += tag_11_packet_size; | |
1810 | if (ECRYPTFS_SIG_SIZE != tag_11_contents_size) { | |
1811 | ecryptfs_printk(KERN_ERR, "Expected " | |
1812 | "signature of size [%d]; " | |
f24b3887 | 1813 | "read size [%zd]\n", |
237fead6 MH |
1814 | ECRYPTFS_SIG_SIZE, |
1815 | tag_11_contents_size); | |
1816 | rc = -EIO; | |
1817 | goto out_wipe_list; | |
1818 | } | |
1819 | ecryptfs_to_hex(new_auth_tok->token.password.signature, | |
1820 | sig_tmp_space, tag_11_contents_size); | |
1821 | new_auth_tok->token.password.signature[ | |
1822 | ECRYPTFS_PASSWORD_SIG_SIZE] = '\0'; | |
e2bd99ec | 1823 | crypt_stat->flags |= ECRYPTFS_ENCRYPTED; |
237fead6 | 1824 | break; |
dddfa461 MH |
1825 | case ECRYPTFS_TAG_1_PACKET_TYPE: |
1826 | rc = parse_tag_1_packet(crypt_stat, | |
1827 | (unsigned char *)&src[i], | |
1828 | &auth_tok_list, &new_auth_tok, | |
1829 | &packet_size, max_packet_size); | |
1830 | if (rc) { | |
1831 | ecryptfs_printk(KERN_ERR, "Error parsing " | |
1832 | "tag 1 packet\n"); | |
1833 | rc = -EIO; | |
1834 | goto out_wipe_list; | |
1835 | } | |
1836 | i += packet_size; | |
e2bd99ec | 1837 | crypt_stat->flags |= ECRYPTFS_ENCRYPTED; |
dddfa461 | 1838 | break; |
237fead6 MH |
1839 | case ECRYPTFS_TAG_11_PACKET_TYPE: |
1840 | ecryptfs_printk(KERN_WARNING, "Invalid packet set " | |
1841 | "(Tag 11 not allowed by itself)\n"); | |
1842 | rc = -EIO; | |
1843 | goto out_wipe_list; | |
237fead6 | 1844 | default: |
f24b3887 TH |
1845 | ecryptfs_printk(KERN_DEBUG, "No packet at offset [%zd] " |
1846 | "of the file header; hex value of " | |
237fead6 MH |
1847 | "character is [0x%.2x]\n", i, src[i]); |
1848 | next_packet_is_auth_tok_packet = 0; | |
1849 | } | |
1850 | } | |
1851 | if (list_empty(&auth_tok_list)) { | |
f4aad16a MH |
1852 | printk(KERN_ERR "The lower file appears to be a non-encrypted " |
1853 | "eCryptfs file; this is not supported in this version " | |
1854 | "of the eCryptfs kernel module\n"); | |
1855 | rc = -EINVAL; | |
237fead6 MH |
1856 | goto out; |
1857 | } | |
f4aad16a MH |
1858 | /* auth_tok_list contains the set of authentication tokens |
1859 | * parsed from the metadata. We need to find a matching | |
1860 | * authentication token that has the secret component(s) | |
1861 | * necessary to decrypt the EFEK in the auth_tok parsed from | |
1862 | * the metadata. There may be several potential matches, but | |
1863 | * just one will be sufficient to decrypt to get the FEK. */ | |
1864 | find_next_matching_auth_tok: | |
1865 | found_auth_tok = 0; | |
1866 | list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) { | |
237fead6 MH |
1867 | candidate_auth_tok = &auth_tok_list_item->auth_tok; |
1868 | if (unlikely(ecryptfs_verbosity > 0)) { | |
1869 | ecryptfs_printk(KERN_DEBUG, | |
f62fd7a7 | 1870 | "Considering candidate auth tok:\n"); |
237fead6 MH |
1871 | ecryptfs_dump_auth_tok(candidate_auth_tok); |
1872 | } | |
5dda6992 MH |
1873 | rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig, |
1874 | candidate_auth_tok); | |
1875 | if (rc) { | |
f4aad16a MH |
1876 | printk(KERN_ERR |
1877 | "Unrecognized candidate auth tok type: [%d]\n", | |
1878 | candidate_auth_tok->token_type); | |
1879 | rc = -EINVAL; | |
1880 | goto out_wipe_list; | |
1881 | } | |
39fac853 | 1882 | rc = ecryptfs_find_auth_tok_for_sig(&auth_tok_key, |
aee683b9 | 1883 | &matching_auth_tok, |
9c79f34f | 1884 | crypt_stat->mount_crypt_stat, |
5dda6992 | 1885 | candidate_auth_tok_sig); |
39fac853 | 1886 | if (!rc) { |
dddfa461 | 1887 | found_auth_tok = 1; |
f4aad16a | 1888 | goto found_matching_auth_tok; |
237fead6 MH |
1889 | } |
1890 | } | |
237fead6 | 1891 | if (!found_auth_tok) { |
f4aad16a MH |
1892 | ecryptfs_printk(KERN_ERR, "Could not find a usable " |
1893 | "authentication token\n"); | |
237fead6 MH |
1894 | rc = -EIO; |
1895 | goto out_wipe_list; | |
dddfa461 | 1896 | } |
f4aad16a | 1897 | found_matching_auth_tok: |
e2bd99ec | 1898 | if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
dddfa461 | 1899 | memcpy(&(candidate_auth_tok->token.private_key), |
f4aad16a | 1900 | &(matching_auth_tok->token.private_key), |
dddfa461 | 1901 | sizeof(struct ecryptfs_private_key)); |
b2987a5e TH |
1902 | up_write(&(auth_tok_key->sem)); |
1903 | key_put(auth_tok_key); | |
f4aad16a | 1904 | rc = decrypt_pki_encrypted_session_key(candidate_auth_tok, |
dddfa461 MH |
1905 | crypt_stat); |
1906 | } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) { | |
237fead6 | 1907 | memcpy(&(candidate_auth_tok->token.password), |
f4aad16a | 1908 | &(matching_auth_tok->token.password), |
237fead6 | 1909 | sizeof(struct ecryptfs_password)); |
b2987a5e TH |
1910 | up_write(&(auth_tok_key->sem)); |
1911 | key_put(auth_tok_key); | |
f4aad16a MH |
1912 | rc = decrypt_passphrase_encrypted_session_key( |
1913 | candidate_auth_tok, crypt_stat); | |
b2987a5e TH |
1914 | } else { |
1915 | up_write(&(auth_tok_key->sem)); | |
1916 | key_put(auth_tok_key); | |
1917 | rc = -EINVAL; | |
dddfa461 MH |
1918 | } |
1919 | if (rc) { | |
f4aad16a MH |
1920 | struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; |
1921 | ||
1922 | ecryptfs_printk(KERN_WARNING, "Error decrypting the " | |
1923 | "session key for authentication token with sig " | |
1924 | "[%.*s]; rc = [%d]. Removing auth tok " | |
1925 | "candidate from the list and searching for " | |
888d57bb JP |
1926 | "the next match.\n", ECRYPTFS_SIG_SIZE_HEX, |
1927 | candidate_auth_tok_sig, rc); | |
f4aad16a MH |
1928 | list_for_each_entry_safe(auth_tok_list_item, |
1929 | auth_tok_list_item_tmp, | |
1930 | &auth_tok_list, list) { | |
1931 | if (candidate_auth_tok | |
1932 | == &auth_tok_list_item->auth_tok) { | |
1933 | list_del(&auth_tok_list_item->list); | |
1934 | kmem_cache_free( | |
1935 | ecryptfs_auth_tok_list_item_cache, | |
1936 | auth_tok_list_item); | |
1937 | goto find_next_matching_auth_tok; | |
1938 | } | |
1939 | } | |
1940 | BUG(); | |
dddfa461 MH |
1941 | } |
1942 | rc = ecryptfs_compute_root_iv(crypt_stat); | |
1943 | if (rc) { | |
1944 | ecryptfs_printk(KERN_ERR, "Error computing " | |
1945 | "the root IV\n"); | |
1946 | goto out_wipe_list; | |
237fead6 MH |
1947 | } |
1948 | rc = ecryptfs_init_crypt_ctx(crypt_stat); | |
1949 | if (rc) { | |
1950 | ecryptfs_printk(KERN_ERR, "Error initializing crypto " | |
1951 | "context for cipher [%s]; rc = [%d]\n", | |
1952 | crypt_stat->cipher, rc); | |
1953 | } | |
1954 | out_wipe_list: | |
1955 | wipe_auth_tok_list(&auth_tok_list); | |
1956 | out: | |
1957 | return rc; | |
1958 | } | |
f4aad16a | 1959 | |
dddfa461 | 1960 | static int |
b2987a5e TH |
1961 | pki_encrypt_session_key(struct key *auth_tok_key, |
1962 | struct ecryptfs_auth_tok *auth_tok, | |
dddfa461 MH |
1963 | struct ecryptfs_crypt_stat *crypt_stat, |
1964 | struct ecryptfs_key_record *key_rec) | |
1965 | { | |
1966 | struct ecryptfs_msg_ctx *msg_ctx = NULL; | |
624ae528 | 1967 | char *payload = NULL; |
99b373ff | 1968 | size_t payload_len = 0; |
dddfa461 MH |
1969 | struct ecryptfs_message *msg; |
1970 | int rc; | |
1971 | ||
1972 | rc = write_tag_66_packet(auth_tok->token.private_key.signature, | |
9c79f34f MH |
1973 | ecryptfs_code_for_cipher_string( |
1974 | crypt_stat->cipher, | |
1975 | crypt_stat->key_size), | |
624ae528 | 1976 | crypt_stat, &payload, &payload_len); |
b2987a5e TH |
1977 | up_write(&(auth_tok_key->sem)); |
1978 | key_put(auth_tok_key); | |
dddfa461 MH |
1979 | if (rc) { |
1980 | ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n"); | |
1981 | goto out; | |
1982 | } | |
624ae528 | 1983 | rc = ecryptfs_send_message(payload, payload_len, &msg_ctx); |
dddfa461 | 1984 | if (rc) { |
624ae528 | 1985 | ecryptfs_printk(KERN_ERR, "Error sending message to " |
290502be | 1986 | "ecryptfsd: %d\n", rc); |
dddfa461 MH |
1987 | goto out; |
1988 | } | |
1989 | rc = ecryptfs_wait_for_response(msg_ctx, &msg); | |
1990 | if (rc) { | |
1991 | ecryptfs_printk(KERN_ERR, "Failed to receive tag 67 packet " | |
1992 | "from the user space daemon\n"); | |
1993 | rc = -EIO; | |
1994 | goto out; | |
1995 | } | |
1996 | rc = parse_tag_67_packet(key_rec, msg); | |
1997 | if (rc) | |
1998 | ecryptfs_printk(KERN_ERR, "Error parsing tag 67 packet\n"); | |
1999 | kfree(msg); | |
2000 | out: | |
624ae528 | 2001 | kfree(payload); |
dddfa461 MH |
2002 | return rc; |
2003 | } | |
2004 | /** | |
2005 | * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet | |
2006 | * @dest: Buffer into which to write the packet | |
22e78faf | 2007 | * @remaining_bytes: Maximum number of bytes that can be writtn |
b2987a5e TH |
2008 | * @auth_tok_key: The authentication token key to unlock and put when done with |
2009 | * @auth_tok | |
22e78faf MH |
2010 | * @auth_tok: The authentication token used for generating the tag 1 packet |
2011 | * @crypt_stat: The cryptographic context | |
2012 | * @key_rec: The key record struct for the tag 1 packet | |
dddfa461 MH |
2013 | * @packet_size: This function will write the number of bytes that end |
2014 | * up constituting the packet; set to zero on error | |
2015 | * | |
2016 | * Returns zero on success; non-zero on error. | |
2017 | */ | |
2018 | static int | |
f4aad16a | 2019 | write_tag_1_packet(char *dest, size_t *remaining_bytes, |
b2987a5e | 2020 | struct key *auth_tok_key, struct ecryptfs_auth_tok *auth_tok, |
dddfa461 | 2021 | struct ecryptfs_crypt_stat *crypt_stat, |
dddfa461 MH |
2022 | struct ecryptfs_key_record *key_rec, size_t *packet_size) |
2023 | { | |
2024 | size_t i; | |
2025 | size_t encrypted_session_key_valid = 0; | |
dddfa461 | 2026 | size_t packet_size_length; |
f4aad16a | 2027 | size_t max_packet_size; |
dddfa461 MH |
2028 | int rc = 0; |
2029 | ||
2030 | (*packet_size) = 0; | |
2031 | ecryptfs_from_hex(key_rec->sig, auth_tok->token.private_key.signature, | |
2032 | ECRYPTFS_SIG_SIZE); | |
2033 | encrypted_session_key_valid = 0; | |
2034 | for (i = 0; i < crypt_stat->key_size; i++) | |
2035 | encrypted_session_key_valid |= | |
2036 | auth_tok->session_key.encrypted_key[i]; | |
2037 | if (encrypted_session_key_valid) { | |
2038 | memcpy(key_rec->enc_key, | |
2039 | auth_tok->session_key.encrypted_key, | |
2040 | auth_tok->session_key.encrypted_key_size); | |
b2987a5e TH |
2041 | up_write(&(auth_tok_key->sem)); |
2042 | key_put(auth_tok_key); | |
dddfa461 MH |
2043 | goto encrypted_session_key_set; |
2044 | } | |
2045 | if (auth_tok->session_key.encrypted_key_size == 0) | |
2046 | auth_tok->session_key.encrypted_key_size = | |
2047 | auth_tok->token.private_key.key_size; | |
b2987a5e TH |
2048 | rc = pki_encrypt_session_key(auth_tok_key, auth_tok, crypt_stat, |
2049 | key_rec); | |
dddfa461 | 2050 | if (rc) { |
f66e883e MH |
2051 | printk(KERN_ERR "Failed to encrypt session key via a key " |
2052 | "module; rc = [%d]\n", rc); | |
dddfa461 MH |
2053 | goto out; |
2054 | } | |
2055 | if (ecryptfs_verbosity > 0) { | |
2056 | ecryptfs_printk(KERN_DEBUG, "Encrypted key:\n"); | |
2057 | ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size); | |
2058 | } | |
2059 | encrypted_session_key_set: | |
f4aad16a MH |
2060 | /* This format is inspired by OpenPGP; see RFC 2440 |
2061 | * packet tag 1 */ | |
2062 | max_packet_size = (1 /* Tag 1 identifier */ | |
2063 | + 3 /* Max Tag 1 packet size */ | |
2064 | + 1 /* Version */ | |
2065 | + ECRYPTFS_SIG_SIZE /* Key identifier */ | |
2066 | + 1 /* Cipher identifier */ | |
2067 | + key_rec->enc_key_size); /* Encrypted key size */ | |
2068 | if (max_packet_size > (*remaining_bytes)) { | |
2069 | printk(KERN_ERR "Packet length larger than maximum allowable; " | |
81acbcd6 | 2070 | "need up to [%td] bytes, but there are only [%td] " |
f4aad16a | 2071 | "available\n", max_packet_size, (*remaining_bytes)); |
dddfa461 MH |
2072 | rc = -EINVAL; |
2073 | goto out; | |
2074 | } | |
2075 | dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE; | |
f66e883e MH |
2076 | rc = ecryptfs_write_packet_length(&dest[(*packet_size)], |
2077 | (max_packet_size - 4), | |
2078 | &packet_size_length); | |
dddfa461 MH |
2079 | if (rc) { |
2080 | ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet " | |
2081 | "header; cannot generate packet length\n"); | |
2082 | goto out; | |
2083 | } | |
2084 | (*packet_size) += packet_size_length; | |
2085 | dest[(*packet_size)++] = 0x03; /* version 3 */ | |
2086 | memcpy(&dest[(*packet_size)], key_rec->sig, ECRYPTFS_SIG_SIZE); | |
2087 | (*packet_size) += ECRYPTFS_SIG_SIZE; | |
2088 | dest[(*packet_size)++] = RFC2440_CIPHER_RSA; | |
2089 | memcpy(&dest[(*packet_size)], key_rec->enc_key, | |
2090 | key_rec->enc_key_size); | |
2091 | (*packet_size) += key_rec->enc_key_size; | |
2092 | out: | |
2093 | if (rc) | |
2094 | (*packet_size) = 0; | |
f4aad16a MH |
2095 | else |
2096 | (*remaining_bytes) -= (*packet_size); | |
dddfa461 MH |
2097 | return rc; |
2098 | } | |
237fead6 MH |
2099 | |
2100 | /** | |
2101 | * write_tag_11_packet | |
2102 | * @dest: Target into which Tag 11 packet is to be written | |
22e78faf | 2103 | * @remaining_bytes: Maximum packet length |
237fead6 MH |
2104 | * @contents: Byte array of contents to copy in |
2105 | * @contents_length: Number of bytes in contents | |
2106 | * @packet_length: Length of the Tag 11 packet written; zero on error | |
2107 | * | |
2108 | * Returns zero on success; non-zero on error. | |
2109 | */ | |
2110 | static int | |
81acbcd6 | 2111 | write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents, |
146a4606 | 2112 | size_t contents_length, size_t *packet_length) |
237fead6 | 2113 | { |
237fead6 | 2114 | size_t packet_size_length; |
146a4606 | 2115 | size_t max_packet_size; |
dddfa461 | 2116 | int rc = 0; |
237fead6 MH |
2117 | |
2118 | (*packet_length) = 0; | |
146a4606 MH |
2119 | /* This format is inspired by OpenPGP; see RFC 2440 |
2120 | * packet tag 11 */ | |
2121 | max_packet_size = (1 /* Tag 11 identifier */ | |
2122 | + 3 /* Max Tag 11 packet size */ | |
2123 | + 1 /* Binary format specifier */ | |
2124 | + 1 /* Filename length */ | |
2125 | + 8 /* Filename ("_CONSOLE") */ | |
2126 | + 4 /* Modification date */ | |
2127 | + contents_length); /* Literal data */ | |
2128 | if (max_packet_size > (*remaining_bytes)) { | |
2129 | printk(KERN_ERR "Packet length larger than maximum allowable; " | |
81acbcd6 | 2130 | "need up to [%td] bytes, but there are only [%td] " |
146a4606 | 2131 | "available\n", max_packet_size, (*remaining_bytes)); |
237fead6 | 2132 | rc = -EINVAL; |
237fead6 MH |
2133 | goto out; |
2134 | } | |
237fead6 | 2135 | dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE; |
f66e883e MH |
2136 | rc = ecryptfs_write_packet_length(&dest[(*packet_length)], |
2137 | (max_packet_size - 4), | |
2138 | &packet_size_length); | |
237fead6 | 2139 | if (rc) { |
146a4606 MH |
2140 | printk(KERN_ERR "Error generating tag 11 packet header; cannot " |
2141 | "generate packet length. rc = [%d]\n", rc); | |
237fead6 MH |
2142 | goto out; |
2143 | } | |
2144 | (*packet_length) += packet_size_length; | |
146a4606 | 2145 | dest[(*packet_length)++] = 0x62; /* binary data format specifier */ |
237fead6 MH |
2146 | dest[(*packet_length)++] = 8; |
2147 | memcpy(&dest[(*packet_length)], "_CONSOLE", 8); | |
2148 | (*packet_length) += 8; | |
237fead6 MH |
2149 | memset(&dest[(*packet_length)], 0x00, 4); |
2150 | (*packet_length) += 4; | |
237fead6 MH |
2151 | memcpy(&dest[(*packet_length)], contents, contents_length); |
2152 | (*packet_length) += contents_length; | |
2153 | out: | |
2154 | if (rc) | |
2155 | (*packet_length) = 0; | |
146a4606 MH |
2156 | else |
2157 | (*remaining_bytes) -= (*packet_length); | |
237fead6 MH |
2158 | return rc; |
2159 | } | |
2160 | ||
2161 | /** | |
2162 | * write_tag_3_packet | |
2163 | * @dest: Buffer into which to write the packet | |
22e78faf | 2164 | * @remaining_bytes: Maximum number of bytes that can be written |
237fead6 MH |
2165 | * @auth_tok: Authentication token |
2166 | * @crypt_stat: The cryptographic context | |
2167 | * @key_rec: encrypted key | |
2168 | * @packet_size: This function will write the number of bytes that end | |
2169 | * up constituting the packet; set to zero on error | |
2170 | * | |
2171 | * Returns zero on success; non-zero on error. | |
2172 | */ | |
2173 | static int | |
f4aad16a MH |
2174 | write_tag_3_packet(char *dest, size_t *remaining_bytes, |
2175 | struct ecryptfs_auth_tok *auth_tok, | |
237fead6 MH |
2176 | struct ecryptfs_crypt_stat *crypt_stat, |
2177 | struct ecryptfs_key_record *key_rec, size_t *packet_size) | |
2178 | { | |
237fead6 | 2179 | size_t i; |
237fead6 MH |
2180 | size_t encrypted_session_key_valid = 0; |
2181 | char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES]; | |
ac97b9f9 MH |
2182 | struct scatterlist dst_sg[2]; |
2183 | struct scatterlist src_sg[2]; | |
237fead6 | 2184 | struct mutex *tfm_mutex = NULL; |
19e66a67 | 2185 | u8 cipher_code; |
f4aad16a MH |
2186 | size_t packet_size_length; |
2187 | size_t max_packet_size; | |
2188 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = | |
2189 | crypt_stat->mount_crypt_stat; | |
3095e8e3 HX |
2190 | struct crypto_skcipher *tfm; |
2191 | struct skcipher_request *req; | |
8bba066f | 2192 | int rc = 0; |
237fead6 MH |
2193 | |
2194 | (*packet_size) = 0; | |
dddfa461 | 2195 | ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature, |
237fead6 | 2196 | ECRYPTFS_SIG_SIZE); |
3095e8e3 | 2197 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&tfm, &tfm_mutex, |
f4aad16a MH |
2198 | crypt_stat->cipher); |
2199 | if (unlikely(rc)) { | |
2200 | printk(KERN_ERR "Internal error whilst attempting to get " | |
2201 | "tfm and mutex for cipher name [%s]; rc = [%d]\n", | |
2202 | crypt_stat->cipher, rc); | |
2203 | goto out; | |
2204 | } | |
2205 | if (mount_crypt_stat->global_default_cipher_key_size == 0) { | |
f4aad16a | 2206 | printk(KERN_WARNING "No key size specified at mount; " |
3095e8e3 | 2207 | "defaulting to [%d]\n", |
9ac0d136 | 2208 | crypto_skcipher_max_keysize(tfm)); |
f4aad16a | 2209 | mount_crypt_stat->global_default_cipher_key_size = |
9ac0d136 | 2210 | crypto_skcipher_max_keysize(tfm); |
237fead6 | 2211 | } |
f4aad16a MH |
2212 | if (crypt_stat->key_size == 0) |
2213 | crypt_stat->key_size = | |
2214 | mount_crypt_stat->global_default_cipher_key_size; | |
237fead6 MH |
2215 | if (auth_tok->session_key.encrypted_key_size == 0) |
2216 | auth_tok->session_key.encrypted_key_size = | |
2217 | crypt_stat->key_size; | |
2218 | if (crypt_stat->key_size == 24 | |
2219 | && strcmp("aes", crypt_stat->cipher) == 0) { | |
2220 | memset((crypt_stat->key + 24), 0, 8); | |
2221 | auth_tok->session_key.encrypted_key_size = 32; | |
f4aad16a MH |
2222 | } else |
2223 | auth_tok->session_key.encrypted_key_size = crypt_stat->key_size; | |
dddfa461 | 2224 | key_rec->enc_key_size = |
237fead6 | 2225 | auth_tok->session_key.encrypted_key_size; |
f4aad16a MH |
2226 | encrypted_session_key_valid = 0; |
2227 | for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++) | |
2228 | encrypted_session_key_valid |= | |
2229 | auth_tok->session_key.encrypted_key[i]; | |
2230 | if (encrypted_session_key_valid) { | |
2231 | ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; " | |
2232 | "using auth_tok->session_key.encrypted_key, " | |
f24b3887 | 2233 | "where key_rec->enc_key_size = [%zd]\n", |
f4aad16a MH |
2234 | key_rec->enc_key_size); |
2235 | memcpy(key_rec->enc_key, | |
2236 | auth_tok->session_key.encrypted_key, | |
2237 | key_rec->enc_key_size); | |
2238 | goto encrypted_session_key_set; | |
2239 | } | |
dddfa461 MH |
2240 | if (auth_tok->token.password.flags & |
2241 | ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) { | |
237fead6 MH |
2242 | ecryptfs_printk(KERN_DEBUG, "Using previously generated " |
2243 | "session key encryption key of size [%d]\n", | |
2244 | auth_tok->token.password. | |
2245 | session_key_encryption_key_bytes); | |
2246 | memcpy(session_key_encryption_key, | |
2247 | auth_tok->token.password.session_key_encryption_key, | |
2248 | crypt_stat->key_size); | |
2249 | ecryptfs_printk(KERN_DEBUG, | |
df2e301f | 2250 | "Cached session key encryption key:\n"); |
237fead6 MH |
2251 | if (ecryptfs_verbosity > 0) |
2252 | ecryptfs_dump_hex(session_key_encryption_key, 16); | |
2253 | } | |
2254 | if (unlikely(ecryptfs_verbosity > 0)) { | |
2255 | ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n"); | |
2256 | ecryptfs_dump_hex(session_key_encryption_key, 16); | |
2257 | } | |
5dda6992 | 2258 | rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size, |
ac97b9f9 MH |
2259 | src_sg, 2); |
2260 | if (rc < 1 || rc > 2) { | |
237fead6 | 2261 | ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
f4aad16a | 2262 | "for crypt_stat session key; expected rc = 1; " |
f24b3887 | 2263 | "got rc = [%d]. key_rec->enc_key_size = [%zd]\n", |
f4aad16a | 2264 | rc, key_rec->enc_key_size); |
237fead6 MH |
2265 | rc = -ENOMEM; |
2266 | goto out; | |
2267 | } | |
5dda6992 | 2268 | rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size, |
ac97b9f9 MH |
2269 | dst_sg, 2); |
2270 | if (rc < 1 || rc > 2) { | |
237fead6 | 2271 | ecryptfs_printk(KERN_ERR, "Error generating scatterlist " |
f4aad16a MH |
2272 | "for crypt_stat encrypted session key; " |
2273 | "expected rc = 1; got rc = [%d]. " | |
f24b3887 | 2274 | "key_rec->enc_key_size = [%zd]\n", rc, |
f4aad16a | 2275 | key_rec->enc_key_size); |
237fead6 MH |
2276 | rc = -ENOMEM; |
2277 | goto out; | |
2278 | } | |
f4aad16a | 2279 | mutex_lock(tfm_mutex); |
3095e8e3 HX |
2280 | rc = crypto_skcipher_setkey(tfm, session_key_encryption_key, |
2281 | crypt_stat->key_size); | |
237fead6 | 2282 | if (rc < 0) { |
f4aad16a | 2283 | mutex_unlock(tfm_mutex); |
237fead6 | 2284 | ecryptfs_printk(KERN_ERR, "Error setting key for crypto " |
8bba066f | 2285 | "context; rc = [%d]\n", rc); |
237fead6 MH |
2286 | goto out; |
2287 | } | |
3095e8e3 HX |
2288 | |
2289 | req = skcipher_request_alloc(tfm, GFP_KERNEL); | |
2290 | if (!req) { | |
2291 | mutex_unlock(tfm_mutex); | |
2292 | ecryptfs_printk(KERN_ERR, "Out of kernel memory whilst " | |
2293 | "attempting to skcipher_request_alloc for " | |
2294 | "%s\n", crypto_skcipher_driver_name(tfm)); | |
2295 | rc = -ENOMEM; | |
2296 | goto out; | |
2297 | } | |
2298 | ||
2299 | skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, | |
2300 | NULL, NULL); | |
2301 | ||
237fead6 | 2302 | rc = 0; |
f24b3887 | 2303 | ecryptfs_printk(KERN_DEBUG, "Encrypting [%zd] bytes of the key\n", |
237fead6 | 2304 | crypt_stat->key_size); |
3095e8e3 HX |
2305 | skcipher_request_set_crypt(req, src_sg, dst_sg, |
2306 | (*key_rec).enc_key_size, NULL); | |
2307 | rc = crypto_skcipher_encrypt(req); | |
f4aad16a | 2308 | mutex_unlock(tfm_mutex); |
3095e8e3 | 2309 | skcipher_request_free(req); |
8bba066f MH |
2310 | if (rc) { |
2311 | printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc); | |
2312 | goto out; | |
2313 | } | |
237fead6 | 2314 | ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n"); |
f4aad16a | 2315 | if (ecryptfs_verbosity > 0) { |
f24b3887 | 2316 | ecryptfs_printk(KERN_DEBUG, "EFEK of size [%zd]:\n", |
f4aad16a | 2317 | key_rec->enc_key_size); |
dddfa461 MH |
2318 | ecryptfs_dump_hex(key_rec->enc_key, |
2319 | key_rec->enc_key_size); | |
237fead6 | 2320 | } |
f4aad16a MH |
2321 | encrypted_session_key_set: |
2322 | /* This format is inspired by OpenPGP; see RFC 2440 | |
2323 | * packet tag 3 */ | |
2324 | max_packet_size = (1 /* Tag 3 identifier */ | |
2325 | + 3 /* Max Tag 3 packet size */ | |
2326 | + 1 /* Version */ | |
2327 | + 1 /* Cipher code */ | |
2328 | + 1 /* S2K specifier */ | |
2329 | + 1 /* Hash identifier */ | |
2330 | + ECRYPTFS_SALT_SIZE /* Salt */ | |
2331 | + 1 /* Hash iterations */ | |
2332 | + key_rec->enc_key_size); /* Encrypted key size */ | |
2333 | if (max_packet_size > (*remaining_bytes)) { | |
81acbcd6 AM |
2334 | printk(KERN_ERR "Packet too large; need up to [%td] bytes, but " |
2335 | "there are only [%td] available\n", max_packet_size, | |
f4aad16a | 2336 | (*remaining_bytes)); |
237fead6 MH |
2337 | rc = -EINVAL; |
2338 | goto out; | |
2339 | } | |
237fead6 | 2340 | dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE; |
f4aad16a MH |
2341 | /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3) |
2342 | * to get the number of octets in the actual Tag 3 packet */ | |
f66e883e MH |
2343 | rc = ecryptfs_write_packet_length(&dest[(*packet_size)], |
2344 | (max_packet_size - 4), | |
2345 | &packet_size_length); | |
237fead6 | 2346 | if (rc) { |
f4aad16a MH |
2347 | printk(KERN_ERR "Error generating tag 3 packet header; cannot " |
2348 | "generate packet length. rc = [%d]\n", rc); | |
237fead6 MH |
2349 | goto out; |
2350 | } | |
2351 | (*packet_size) += packet_size_length; | |
2352 | dest[(*packet_size)++] = 0x04; /* version 4 */ | |
f4aad16a MH |
2353 | /* TODO: Break from RFC2440 so that arbitrary ciphers can be |
2354 | * specified with strings */ | |
9c79f34f MH |
2355 | cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher, |
2356 | crypt_stat->key_size); | |
237fead6 MH |
2357 | if (cipher_code == 0) { |
2358 | ecryptfs_printk(KERN_WARNING, "Unable to generate code for " | |
2359 | "cipher [%s]\n", crypt_stat->cipher); | |
2360 | rc = -EINVAL; | |
2361 | goto out; | |
2362 | } | |
2363 | dest[(*packet_size)++] = cipher_code; | |
2364 | dest[(*packet_size)++] = 0x03; /* S2K */ | |
2365 | dest[(*packet_size)++] = 0x01; /* MD5 (TODO: parameterize) */ | |
2366 | memcpy(&dest[(*packet_size)], auth_tok->token.password.salt, | |
2367 | ECRYPTFS_SALT_SIZE); | |
2368 | (*packet_size) += ECRYPTFS_SALT_SIZE; /* salt */ | |
2369 | dest[(*packet_size)++] = 0x60; /* hash iterations (65536) */ | |
dddfa461 MH |
2370 | memcpy(&dest[(*packet_size)], key_rec->enc_key, |
2371 | key_rec->enc_key_size); | |
2372 | (*packet_size) += key_rec->enc_key_size; | |
237fead6 | 2373 | out: |
237fead6 MH |
2374 | if (rc) |
2375 | (*packet_size) = 0; | |
f4aad16a MH |
2376 | else |
2377 | (*remaining_bytes) -= (*packet_size); | |
237fead6 MH |
2378 | return rc; |
2379 | } | |
2380 | ||
eb95e7ff MH |
2381 | struct kmem_cache *ecryptfs_key_record_cache; |
2382 | ||
237fead6 MH |
2383 | /** |
2384 | * ecryptfs_generate_key_packet_set | |
22e78faf | 2385 | * @dest_base: Virtual address from which to write the key record set |
237fead6 MH |
2386 | * @crypt_stat: The cryptographic context from which the |
2387 | * authentication tokens will be retrieved | |
2388 | * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat | |
2389 | * for the global parameters | |
2390 | * @len: The amount written | |
2391 | * @max: The maximum amount of data allowed to be written | |
2392 | * | |
2393 | * Generates a key packet set and writes it to the virtual address | |
2394 | * passed in. | |
2395 | * | |
2396 | * Returns zero on success; non-zero on error. | |
2397 | */ | |
2398 | int | |
2399 | ecryptfs_generate_key_packet_set(char *dest_base, | |
2400 | struct ecryptfs_crypt_stat *crypt_stat, | |
2401 | struct dentry *ecryptfs_dentry, size_t *len, | |
2402 | size_t max) | |
2403 | { | |
237fead6 | 2404 | struct ecryptfs_auth_tok *auth_tok; |
0e1fc5ef | 2405 | struct key *auth_tok_key = NULL; |
237fead6 MH |
2406 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
2407 | &ecryptfs_superblock_to_private( | |
2408 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
2409 | size_t written; | |
eb95e7ff | 2410 | struct ecryptfs_key_record *key_rec; |
f4aad16a | 2411 | struct ecryptfs_key_sig *key_sig; |
dddfa461 | 2412 | int rc = 0; |
237fead6 MH |
2413 | |
2414 | (*len) = 0; | |
f4aad16a | 2415 | mutex_lock(&crypt_stat->keysig_list_mutex); |
eb95e7ff MH |
2416 | key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL); |
2417 | if (!key_rec) { | |
2418 | rc = -ENOMEM; | |
2419 | goto out; | |
2420 | } | |
f4aad16a MH |
2421 | list_for_each_entry(key_sig, &crypt_stat->keysig_list, |
2422 | crypt_stat_list) { | |
2423 | memset(key_rec, 0, sizeof(*key_rec)); | |
0e1fc5ef RS |
2424 | rc = ecryptfs_find_global_auth_tok_for_sig(&auth_tok_key, |
2425 | &auth_tok, | |
f4aad16a MH |
2426 | mount_crypt_stat, |
2427 | key_sig->keysig); | |
2428 | if (rc) { | |
0e1fc5ef RS |
2429 | printk(KERN_WARNING "Unable to retrieve auth tok with " |
2430 | "sig = [%s]\n", key_sig->keysig); | |
2431 | rc = process_find_global_auth_tok_for_sig_err(rc); | |
f4aad16a MH |
2432 | goto out_free; |
2433 | } | |
237fead6 MH |
2434 | if (auth_tok->token_type == ECRYPTFS_PASSWORD) { |
2435 | rc = write_tag_3_packet((dest_base + (*len)), | |
f4aad16a | 2436 | &max, auth_tok, |
eb95e7ff | 2437 | crypt_stat, key_rec, |
237fead6 | 2438 | &written); |
b2987a5e TH |
2439 | up_write(&(auth_tok_key->sem)); |
2440 | key_put(auth_tok_key); | |
237fead6 MH |
2441 | if (rc) { |
2442 | ecryptfs_printk(KERN_WARNING, "Error " | |
2443 | "writing tag 3 packet\n"); | |
eb95e7ff | 2444 | goto out_free; |
237fead6 MH |
2445 | } |
2446 | (*len) += written; | |
2447 | /* Write auth tok signature packet */ | |
f4aad16a MH |
2448 | rc = write_tag_11_packet((dest_base + (*len)), &max, |
2449 | key_rec->sig, | |
2450 | ECRYPTFS_SIG_SIZE, &written); | |
237fead6 MH |
2451 | if (rc) { |
2452 | ecryptfs_printk(KERN_ERR, "Error writing " | |
2453 | "auth tok signature packet\n"); | |
eb95e7ff | 2454 | goto out_free; |
237fead6 MH |
2455 | } |
2456 | (*len) += written; | |
dddfa461 | 2457 | } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { |
b2987a5e TH |
2458 | rc = write_tag_1_packet(dest_base + (*len), &max, |
2459 | auth_tok_key, auth_tok, | |
f4aad16a | 2460 | crypt_stat, key_rec, &written); |
dddfa461 MH |
2461 | if (rc) { |
2462 | ecryptfs_printk(KERN_WARNING, "Error " | |
2463 | "writing tag 1 packet\n"); | |
eb95e7ff | 2464 | goto out_free; |
dddfa461 MH |
2465 | } |
2466 | (*len) += written; | |
237fead6 | 2467 | } else { |
b2987a5e TH |
2468 | up_write(&(auth_tok_key->sem)); |
2469 | key_put(auth_tok_key); | |
237fead6 MH |
2470 | ecryptfs_printk(KERN_WARNING, "Unsupported " |
2471 | "authentication token type\n"); | |
2472 | rc = -EINVAL; | |
eb95e7ff | 2473 | goto out_free; |
237fead6 | 2474 | } |
f4aad16a MH |
2475 | } |
2476 | if (likely(max > 0)) { | |
237fead6 MH |
2477 | dest_base[(*len)] = 0x00; |
2478 | } else { | |
2479 | ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n"); | |
2480 | rc = -EIO; | |
2481 | } | |
eb95e7ff MH |
2482 | out_free: |
2483 | kmem_cache_free(ecryptfs_key_record_cache, key_rec); | |
237fead6 MH |
2484 | out: |
2485 | if (rc) | |
2486 | (*len) = 0; | |
f4aad16a MH |
2487 | mutex_unlock(&crypt_stat->keysig_list_mutex); |
2488 | return rc; | |
2489 | } | |
2490 | ||
2491 | struct kmem_cache *ecryptfs_key_sig_cache; | |
2492 | ||
2493 | int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig) | |
2494 | { | |
2495 | struct ecryptfs_key_sig *new_key_sig; | |
f4aad16a MH |
2496 | |
2497 | new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL); | |
1a0bba4f | 2498 | if (!new_key_sig) |
aa06117f | 2499 | return -ENOMEM; |
1a0bba4f | 2500 | |
f4aad16a | 2501 | memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX); |
7762e230 | 2502 | new_key_sig->keysig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
aa06117f | 2503 | /* Caller must hold keysig_list_mutex */ |
f4aad16a | 2504 | list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list); |
aa06117f RD |
2505 | |
2506 | return 0; | |
237fead6 | 2507 | } |
f4aad16a MH |
2508 | |
2509 | struct kmem_cache *ecryptfs_global_auth_tok_cache; | |
2510 | ||
2511 | int | |
2512 | ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
84814d64 | 2513 | char *sig, u32 global_auth_tok_flags) |
f4aad16a MH |
2514 | { |
2515 | struct ecryptfs_global_auth_tok *new_auth_tok; | |
f4aad16a | 2516 | |
459e2164 | 2517 | new_auth_tok = kmem_cache_zalloc(ecryptfs_global_auth_tok_cache, |
f4aad16a | 2518 | GFP_KERNEL); |
a463ce5b ME |
2519 | if (!new_auth_tok) |
2520 | return -ENOMEM; | |
2521 | ||
f4aad16a | 2522 | memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX); |
84814d64 | 2523 | new_auth_tok->flags = global_auth_tok_flags; |
f4aad16a MH |
2524 | new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
2525 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
2526 | list_add(&new_auth_tok->mount_crypt_stat_list, | |
2527 | &mount_crypt_stat->global_auth_tok_list); | |
f4aad16a | 2528 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); |
a463ce5b | 2529 | return 0; |
f4aad16a MH |
2530 | } |
2531 |