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Commit | Line | Data |
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237fead6 MH |
1 | /** |
2 | * eCryptfs: Linux filesystem encryption layer | |
3 | * | |
4 | * Copyright (C) 1997-2004 Erez Zadok | |
5 | * Copyright (C) 2001-2004 Stony Brook University | |
dd2a3b7a | 6 | * Copyright (C) 2004-2007 International Business Machines Corp. |
237fead6 MH |
7 | * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> |
8 | * Michael C. Thompson <mcthomps@us.ibm.com> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License as | |
12 | * published by the Free Software Foundation; either version 2 of the | |
13 | * License, or (at your option) any later version. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, but | |
16 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | * General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License | |
21 | * along with this program; if not, write to the Free Software | |
22 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
23 | * 02111-1307, USA. | |
24 | */ | |
25 | ||
26 | #include <linux/fs.h> | |
27 | #include <linux/mount.h> | |
28 | #include <linux/pagemap.h> | |
29 | #include <linux/random.h> | |
30 | #include <linux/compiler.h> | |
31 | #include <linux/key.h> | |
32 | #include <linux/namei.h> | |
33 | #include <linux/crypto.h> | |
34 | #include <linux/file.h> | |
35 | #include <linux/scatterlist.h> | |
5a0e3ad6 | 36 | #include <linux/slab.h> |
29335c6a | 37 | #include <asm/unaligned.h> |
237fead6 MH |
38 | #include "ecryptfs_kernel.h" |
39 | ||
40 | static int | |
41 | ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
42 | struct page *dst_page, int dst_offset, | |
43 | struct page *src_page, int src_offset, int size, | |
44 | unsigned char *iv); | |
45 | static int | |
46 | ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
47 | struct page *dst_page, int dst_offset, | |
48 | struct page *src_page, int src_offset, int size, | |
49 | unsigned char *iv); | |
50 | ||
51 | /** | |
52 | * ecryptfs_to_hex | |
53 | * @dst: Buffer to take hex character representation of contents of | |
54 | * src; must be at least of size (src_size * 2) | |
55 | * @src: Buffer to be converted to a hex string respresentation | |
56 | * @src_size: number of bytes to convert | |
57 | */ | |
58 | void ecryptfs_to_hex(char *dst, char *src, size_t src_size) | |
59 | { | |
60 | int x; | |
61 | ||
62 | for (x = 0; x < src_size; x++) | |
63 | sprintf(&dst[x * 2], "%.2x", (unsigned char)src[x]); | |
64 | } | |
65 | ||
66 | /** | |
67 | * ecryptfs_from_hex | |
68 | * @dst: Buffer to take the bytes from src hex; must be at least of | |
69 | * size (src_size / 2) | |
70 | * @src: Buffer to be converted from a hex string respresentation to raw value | |
71 | * @dst_size: size of dst buffer, or number of hex characters pairs to convert | |
72 | */ | |
73 | void ecryptfs_from_hex(char *dst, char *src, int dst_size) | |
74 | { | |
75 | int x; | |
76 | char tmp[3] = { 0, }; | |
77 | ||
78 | for (x = 0; x < dst_size; x++) { | |
79 | tmp[0] = src[x * 2]; | |
80 | tmp[1] = src[x * 2 + 1]; | |
81 | dst[x] = (unsigned char)simple_strtol(tmp, NULL, 16); | |
82 | } | |
83 | } | |
84 | ||
85 | /** | |
86 | * ecryptfs_calculate_md5 - calculates the md5 of @src | |
87 | * @dst: Pointer to 16 bytes of allocated memory | |
88 | * @crypt_stat: Pointer to crypt_stat struct for the current inode | |
89 | * @src: Data to be md5'd | |
90 | * @len: Length of @src | |
91 | * | |
92 | * Uses the allocated crypto context that crypt_stat references to | |
93 | * generate the MD5 sum of the contents of src. | |
94 | */ | |
95 | static int ecryptfs_calculate_md5(char *dst, | |
96 | struct ecryptfs_crypt_stat *crypt_stat, | |
97 | char *src, int len) | |
98 | { | |
237fead6 | 99 | struct scatterlist sg; |
565d9724 MH |
100 | struct hash_desc desc = { |
101 | .tfm = crypt_stat->hash_tfm, | |
102 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
103 | }; | |
104 | int rc = 0; | |
237fead6 | 105 | |
565d9724 | 106 | mutex_lock(&crypt_stat->cs_hash_tfm_mutex); |
237fead6 | 107 | sg_init_one(&sg, (u8 *)src, len); |
565d9724 MH |
108 | if (!desc.tfm) { |
109 | desc.tfm = crypto_alloc_hash(ECRYPTFS_DEFAULT_HASH, 0, | |
110 | CRYPTO_ALG_ASYNC); | |
111 | if (IS_ERR(desc.tfm)) { | |
112 | rc = PTR_ERR(desc.tfm); | |
237fead6 | 113 | ecryptfs_printk(KERN_ERR, "Error attempting to " |
565d9724 MH |
114 | "allocate crypto context; rc = [%d]\n", |
115 | rc); | |
237fead6 MH |
116 | goto out; |
117 | } | |
565d9724 | 118 | crypt_stat->hash_tfm = desc.tfm; |
237fead6 | 119 | } |
8a29f2b0 MH |
120 | rc = crypto_hash_init(&desc); |
121 | if (rc) { | |
122 | printk(KERN_ERR | |
123 | "%s: Error initializing crypto hash; rc = [%d]\n", | |
18d1dbf1 | 124 | __func__, rc); |
8a29f2b0 MH |
125 | goto out; |
126 | } | |
127 | rc = crypto_hash_update(&desc, &sg, len); | |
128 | if (rc) { | |
129 | printk(KERN_ERR | |
130 | "%s: Error updating crypto hash; rc = [%d]\n", | |
18d1dbf1 | 131 | __func__, rc); |
8a29f2b0 MH |
132 | goto out; |
133 | } | |
134 | rc = crypto_hash_final(&desc, dst); | |
135 | if (rc) { | |
136 | printk(KERN_ERR | |
137 | "%s: Error finalizing crypto hash; rc = [%d]\n", | |
18d1dbf1 | 138 | __func__, rc); |
8a29f2b0 MH |
139 | goto out; |
140 | } | |
237fead6 | 141 | out: |
8a29f2b0 | 142 | mutex_unlock(&crypt_stat->cs_hash_tfm_mutex); |
237fead6 MH |
143 | return rc; |
144 | } | |
145 | ||
cd9d67df MH |
146 | static int ecryptfs_crypto_api_algify_cipher_name(char **algified_name, |
147 | char *cipher_name, | |
148 | char *chaining_modifier) | |
8bba066f MH |
149 | { |
150 | int cipher_name_len = strlen(cipher_name); | |
151 | int chaining_modifier_len = strlen(chaining_modifier); | |
152 | int algified_name_len; | |
153 | int rc; | |
154 | ||
155 | algified_name_len = (chaining_modifier_len + cipher_name_len + 3); | |
156 | (*algified_name) = kmalloc(algified_name_len, GFP_KERNEL); | |
7bd473fc | 157 | if (!(*algified_name)) { |
8bba066f MH |
158 | rc = -ENOMEM; |
159 | goto out; | |
160 | } | |
161 | snprintf((*algified_name), algified_name_len, "%s(%s)", | |
162 | chaining_modifier, cipher_name); | |
163 | rc = 0; | |
164 | out: | |
165 | return rc; | |
166 | } | |
167 | ||
237fead6 MH |
168 | /** |
169 | * ecryptfs_derive_iv | |
170 | * @iv: destination for the derived iv vale | |
171 | * @crypt_stat: Pointer to crypt_stat struct for the current inode | |
d6a13c17 | 172 | * @offset: Offset of the extent whose IV we are to derive |
237fead6 MH |
173 | * |
174 | * Generate the initialization vector from the given root IV and page | |
175 | * offset. | |
176 | * | |
177 | * Returns zero on success; non-zero on error. | |
178 | */ | |
a34f60f7 MH |
179 | int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat, |
180 | loff_t offset) | |
237fead6 MH |
181 | { |
182 | int rc = 0; | |
183 | char dst[MD5_DIGEST_SIZE]; | |
184 | char src[ECRYPTFS_MAX_IV_BYTES + 16]; | |
185 | ||
186 | if (unlikely(ecryptfs_verbosity > 0)) { | |
187 | ecryptfs_printk(KERN_DEBUG, "root iv:\n"); | |
188 | ecryptfs_dump_hex(crypt_stat->root_iv, crypt_stat->iv_bytes); | |
189 | } | |
190 | /* TODO: It is probably secure to just cast the least | |
191 | * significant bits of the root IV into an unsigned long and | |
192 | * add the offset to that rather than go through all this | |
193 | * hashing business. -Halcrow */ | |
194 | memcpy(src, crypt_stat->root_iv, crypt_stat->iv_bytes); | |
195 | memset((src + crypt_stat->iv_bytes), 0, 16); | |
d6a13c17 | 196 | snprintf((src + crypt_stat->iv_bytes), 16, "%lld", offset); |
237fead6 MH |
197 | if (unlikely(ecryptfs_verbosity > 0)) { |
198 | ecryptfs_printk(KERN_DEBUG, "source:\n"); | |
199 | ecryptfs_dump_hex(src, (crypt_stat->iv_bytes + 16)); | |
200 | } | |
201 | rc = ecryptfs_calculate_md5(dst, crypt_stat, src, | |
202 | (crypt_stat->iv_bytes + 16)); | |
203 | if (rc) { | |
204 | ecryptfs_printk(KERN_WARNING, "Error attempting to compute " | |
205 | "MD5 while generating IV for a page\n"); | |
206 | goto out; | |
207 | } | |
208 | memcpy(iv, dst, crypt_stat->iv_bytes); | |
209 | if (unlikely(ecryptfs_verbosity > 0)) { | |
210 | ecryptfs_printk(KERN_DEBUG, "derived iv:\n"); | |
211 | ecryptfs_dump_hex(iv, crypt_stat->iv_bytes); | |
212 | } | |
213 | out: | |
214 | return rc; | |
215 | } | |
216 | ||
217 | /** | |
218 | * ecryptfs_init_crypt_stat | |
219 | * @crypt_stat: Pointer to the crypt_stat struct to initialize. | |
220 | * | |
221 | * Initialize the crypt_stat structure. | |
222 | */ | |
223 | void | |
224 | ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat) | |
225 | { | |
226 | memset((void *)crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat)); | |
f4aad16a MH |
227 | INIT_LIST_HEAD(&crypt_stat->keysig_list); |
228 | mutex_init(&crypt_stat->keysig_list_mutex); | |
237fead6 MH |
229 | mutex_init(&crypt_stat->cs_mutex); |
230 | mutex_init(&crypt_stat->cs_tfm_mutex); | |
565d9724 | 231 | mutex_init(&crypt_stat->cs_hash_tfm_mutex); |
e2bd99ec | 232 | crypt_stat->flags |= ECRYPTFS_STRUCT_INITIALIZED; |
237fead6 MH |
233 | } |
234 | ||
235 | /** | |
fcd12835 | 236 | * ecryptfs_destroy_crypt_stat |
237fead6 MH |
237 | * @crypt_stat: Pointer to the crypt_stat struct to initialize. |
238 | * | |
239 | * Releases all memory associated with a crypt_stat struct. | |
240 | */ | |
fcd12835 | 241 | void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat) |
237fead6 | 242 | { |
f4aad16a MH |
243 | struct ecryptfs_key_sig *key_sig, *key_sig_tmp; |
244 | ||
237fead6 | 245 | if (crypt_stat->tfm) |
4dfea4f0 | 246 | crypto_free_ablkcipher(crypt_stat->tfm); |
565d9724 MH |
247 | if (crypt_stat->hash_tfm) |
248 | crypto_free_hash(crypt_stat->hash_tfm); | |
f4aad16a MH |
249 | list_for_each_entry_safe(key_sig, key_sig_tmp, |
250 | &crypt_stat->keysig_list, crypt_stat_list) { | |
251 | list_del(&key_sig->crypt_stat_list); | |
252 | kmem_cache_free(ecryptfs_key_sig_cache, key_sig); | |
253 | } | |
237fead6 MH |
254 | memset(crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat)); |
255 | } | |
256 | ||
fcd12835 | 257 | void ecryptfs_destroy_mount_crypt_stat( |
237fead6 MH |
258 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) |
259 | { | |
f4aad16a MH |
260 | struct ecryptfs_global_auth_tok *auth_tok, *auth_tok_tmp; |
261 | ||
262 | if (!(mount_crypt_stat->flags & ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED)) | |
263 | return; | |
264 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
265 | list_for_each_entry_safe(auth_tok, auth_tok_tmp, | |
266 | &mount_crypt_stat->global_auth_tok_list, | |
267 | mount_crypt_stat_list) { | |
268 | list_del(&auth_tok->mount_crypt_stat_list); | |
f4aad16a MH |
269 | if (auth_tok->global_auth_tok_key |
270 | && !(auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID)) | |
271 | key_put(auth_tok->global_auth_tok_key); | |
272 | kmem_cache_free(ecryptfs_global_auth_tok_cache, auth_tok); | |
273 | } | |
274 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
237fead6 MH |
275 | memset(mount_crypt_stat, 0, sizeof(struct ecryptfs_mount_crypt_stat)); |
276 | } | |
277 | ||
278 | /** | |
279 | * virt_to_scatterlist | |
280 | * @addr: Virtual address | |
281 | * @size: Size of data; should be an even multiple of the block size | |
282 | * @sg: Pointer to scatterlist array; set to NULL to obtain only | |
283 | * the number of scatterlist structs required in array | |
284 | * @sg_size: Max array size | |
285 | * | |
286 | * Fills in a scatterlist array with page references for a passed | |
287 | * virtual address. | |
288 | * | |
289 | * Returns the number of scatterlist structs in array used | |
290 | */ | |
291 | int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg, | |
292 | int sg_size) | |
293 | { | |
294 | int i = 0; | |
295 | struct page *pg; | |
296 | int offset; | |
297 | int remainder_of_page; | |
298 | ||
68e3f5dd HX |
299 | sg_init_table(sg, sg_size); |
300 | ||
237fead6 MH |
301 | while (size > 0 && i < sg_size) { |
302 | pg = virt_to_page(addr); | |
303 | offset = offset_in_page(addr); | |
a07c48ad | 304 | sg_set_page(&sg[i], pg, 0, offset); |
237fead6 MH |
305 | remainder_of_page = PAGE_CACHE_SIZE - offset; |
306 | if (size >= remainder_of_page) { | |
a07c48ad | 307 | sg[i].length = remainder_of_page; |
237fead6 MH |
308 | addr += remainder_of_page; |
309 | size -= remainder_of_page; | |
310 | } else { | |
a07c48ad | 311 | sg[i].length = size; |
237fead6 MH |
312 | addr += size; |
313 | size = 0; | |
314 | } | |
315 | i++; | |
316 | } | |
317 | if (size > 0) | |
318 | return -ENOMEM; | |
319 | return i; | |
320 | } | |
321 | ||
4dfea4f0 TH |
322 | struct extent_crypt_result { |
323 | struct completion completion; | |
324 | int rc; | |
325 | }; | |
326 | ||
327 | static void extent_crypt_complete(struct crypto_async_request *req, int rc) | |
328 | { | |
329 | struct extent_crypt_result *ecr = req->data; | |
330 | ||
331 | if (rc == -EINPROGRESS) | |
332 | return; | |
333 | ||
334 | ecr->rc = rc; | |
335 | complete(&ecr->completion); | |
336 | } | |
337 | ||
237fead6 MH |
338 | /** |
339 | * encrypt_scatterlist | |
340 | * @crypt_stat: Pointer to the crypt_stat struct to initialize. | |
341 | * @dest_sg: Destination of encrypted data | |
342 | * @src_sg: Data to be encrypted | |
343 | * @size: Length of data to be encrypted | |
344 | * @iv: iv to use during encryption | |
345 | * | |
346 | * Returns the number of bytes encrypted; negative value on error | |
347 | */ | |
348 | static int encrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, | |
349 | struct scatterlist *dest_sg, | |
350 | struct scatterlist *src_sg, int size, | |
351 | unsigned char *iv) | |
352 | { | |
4dfea4f0 TH |
353 | struct ablkcipher_request *req = NULL; |
354 | struct extent_crypt_result ecr; | |
237fead6 MH |
355 | int rc = 0; |
356 | ||
357 | BUG_ON(!crypt_stat || !crypt_stat->tfm | |
e2bd99ec | 358 | || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)); |
237fead6 | 359 | if (unlikely(ecryptfs_verbosity > 0)) { |
f24b3887 | 360 | ecryptfs_printk(KERN_DEBUG, "Key size [%zd]; key:\n", |
237fead6 MH |
361 | crypt_stat->key_size); |
362 | ecryptfs_dump_hex(crypt_stat->key, | |
363 | crypt_stat->key_size); | |
364 | } | |
4dfea4f0 TH |
365 | |
366 | init_completion(&ecr.completion); | |
367 | ||
237fead6 | 368 | mutex_lock(&crypt_stat->cs_tfm_mutex); |
4dfea4f0 TH |
369 | req = ablkcipher_request_alloc(crypt_stat->tfm, GFP_NOFS); |
370 | if (!req) { | |
237fead6 | 371 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
4dfea4f0 | 372 | rc = -ENOMEM; |
237fead6 MH |
373 | goto out; |
374 | } | |
4dfea4f0 TH |
375 | |
376 | ablkcipher_request_set_callback(req, | |
377 | CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, | |
378 | extent_crypt_complete, &ecr); | |
379 | /* Consider doing this once, when the file is opened */ | |
380 | if (!(crypt_stat->flags & ECRYPTFS_KEY_SET)) { | |
381 | rc = crypto_ablkcipher_setkey(crypt_stat->tfm, crypt_stat->key, | |
382 | crypt_stat->key_size); | |
383 | if (rc) { | |
384 | ecryptfs_printk(KERN_ERR, | |
385 | "Error setting key; rc = [%d]\n", | |
386 | rc); | |
387 | mutex_unlock(&crypt_stat->cs_tfm_mutex); | |
388 | rc = -EINVAL; | |
389 | goto out; | |
390 | } | |
391 | crypt_stat->flags |= ECRYPTFS_KEY_SET; | |
392 | } | |
237fead6 | 393 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
4dfea4f0 TH |
394 | ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes.\n", size); |
395 | ablkcipher_request_set_crypt(req, src_sg, dest_sg, size, iv); | |
396 | rc = crypto_ablkcipher_encrypt(req); | |
397 | if (rc == -EINPROGRESS || rc == -EBUSY) { | |
398 | struct extent_crypt_result *ecr = req->base.data; | |
399 | ||
400 | wait_for_completion(&ecr->completion); | |
401 | rc = ecr->rc; | |
402 | INIT_COMPLETION(ecr->completion); | |
403 | } | |
237fead6 | 404 | out: |
4dfea4f0 | 405 | ablkcipher_request_free(req); |
237fead6 MH |
406 | return rc; |
407 | } | |
408 | ||
0216f7f7 MH |
409 | /** |
410 | * ecryptfs_lower_offset_for_extent | |
411 | * | |
412 | * Convert an eCryptfs page index into a lower byte offset | |
413 | */ | |
7896b631 AB |
414 | static void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num, |
415 | struct ecryptfs_crypt_stat *crypt_stat) | |
0216f7f7 | 416 | { |
157f1071 TH |
417 | (*offset) = ecryptfs_lower_header_size(crypt_stat) |
418 | + (crypt_stat->extent_size * extent_num); | |
0216f7f7 MH |
419 | } |
420 | ||
421 | /** | |
422 | * ecryptfs_encrypt_extent | |
423 | * @enc_extent_page: Allocated page into which to encrypt the data in | |
424 | * @page | |
425 | * @crypt_stat: crypt_stat containing cryptographic context for the | |
426 | * encryption operation | |
427 | * @page: Page containing plaintext data extent to encrypt | |
428 | * @extent_offset: Page extent offset for use in generating IV | |
429 | * | |
430 | * Encrypts one extent of data. | |
431 | * | |
432 | * Return zero on success; non-zero otherwise | |
433 | */ | |
434 | static int ecryptfs_encrypt_extent(struct page *enc_extent_page, | |
435 | struct ecryptfs_crypt_stat *crypt_stat, | |
436 | struct page *page, | |
437 | unsigned long extent_offset) | |
438 | { | |
d6a13c17 | 439 | loff_t extent_base; |
0216f7f7 MH |
440 | char extent_iv[ECRYPTFS_MAX_IV_BYTES]; |
441 | int rc; | |
442 | ||
d6a13c17 | 443 | extent_base = (((loff_t)page->index) |
0216f7f7 MH |
444 | * (PAGE_CACHE_SIZE / crypt_stat->extent_size)); |
445 | rc = ecryptfs_derive_iv(extent_iv, crypt_stat, | |
446 | (extent_base + extent_offset)); | |
447 | if (rc) { | |
888d57bb JP |
448 | ecryptfs_printk(KERN_ERR, "Error attempting to derive IV for " |
449 | "extent [0x%.16llx]; rc = [%d]\n", | |
450 | (unsigned long long)(extent_base + extent_offset), rc); | |
0216f7f7 MH |
451 | goto out; |
452 | } | |
0216f7f7 MH |
453 | rc = ecryptfs_encrypt_page_offset(crypt_stat, enc_extent_page, 0, |
454 | page, (extent_offset | |
455 | * crypt_stat->extent_size), | |
456 | crypt_stat->extent_size, extent_iv); | |
457 | if (rc < 0) { | |
458 | printk(KERN_ERR "%s: Error attempting to encrypt page with " | |
459 | "page->index = [%ld], extent_offset = [%ld]; " | |
18d1dbf1 | 460 | "rc = [%d]\n", __func__, page->index, extent_offset, |
0216f7f7 MH |
461 | rc); |
462 | goto out; | |
463 | } | |
464 | rc = 0; | |
0216f7f7 MH |
465 | out: |
466 | return rc; | |
467 | } | |
468 | ||
237fead6 MH |
469 | /** |
470 | * ecryptfs_encrypt_page | |
0216f7f7 MH |
471 | * @page: Page mapped from the eCryptfs inode for the file; contains |
472 | * decrypted content that needs to be encrypted (to a temporary | |
473 | * page; not in place) and written out to the lower file | |
237fead6 MH |
474 | * |
475 | * Encrypt an eCryptfs page. This is done on a per-extent basis. Note | |
476 | * that eCryptfs pages may straddle the lower pages -- for instance, | |
477 | * if the file was created on a machine with an 8K page size | |
478 | * (resulting in an 8K header), and then the file is copied onto a | |
479 | * host with a 32K page size, then when reading page 0 of the eCryptfs | |
480 | * file, 24K of page 0 of the lower file will be read and decrypted, | |
481 | * and then 8K of page 1 of the lower file will be read and decrypted. | |
482 | * | |
237fead6 MH |
483 | * Returns zero on success; negative on error |
484 | */ | |
0216f7f7 | 485 | int ecryptfs_encrypt_page(struct page *page) |
237fead6 | 486 | { |
0216f7f7 | 487 | struct inode *ecryptfs_inode; |
237fead6 | 488 | struct ecryptfs_crypt_stat *crypt_stat; |
7fcba054 ES |
489 | char *enc_extent_virt; |
490 | struct page *enc_extent_page = NULL; | |
0216f7f7 | 491 | loff_t extent_offset; |
237fead6 | 492 | int rc = 0; |
0216f7f7 MH |
493 | |
494 | ecryptfs_inode = page->mapping->host; | |
495 | crypt_stat = | |
496 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); | |
13a791b4 | 497 | BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)); |
7fcba054 ES |
498 | enc_extent_page = alloc_page(GFP_USER); |
499 | if (!enc_extent_page) { | |
0216f7f7 MH |
500 | rc = -ENOMEM; |
501 | ecryptfs_printk(KERN_ERR, "Error allocating memory for " | |
502 | "encrypted extent\n"); | |
503 | goto out; | |
504 | } | |
7fcba054 | 505 | enc_extent_virt = kmap(enc_extent_page); |
0216f7f7 MH |
506 | for (extent_offset = 0; |
507 | extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); | |
508 | extent_offset++) { | |
509 | loff_t offset; | |
510 | ||
511 | rc = ecryptfs_encrypt_extent(enc_extent_page, crypt_stat, page, | |
512 | extent_offset); | |
237fead6 | 513 | if (rc) { |
0216f7f7 | 514 | printk(KERN_ERR "%s: Error encrypting extent; " |
18d1dbf1 | 515 | "rc = [%d]\n", __func__, rc); |
237fead6 MH |
516 | goto out; |
517 | } | |
0216f7f7 | 518 | ecryptfs_lower_offset_for_extent( |
d6a13c17 MH |
519 | &offset, ((((loff_t)page->index) |
520 | * (PAGE_CACHE_SIZE | |
521 | / crypt_stat->extent_size)) | |
0216f7f7 MH |
522 | + extent_offset), crypt_stat); |
523 | rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt, | |
524 | offset, crypt_stat->extent_size); | |
96a7b9c2 | 525 | if (rc < 0) { |
0216f7f7 MH |
526 | ecryptfs_printk(KERN_ERR, "Error attempting " |
527 | "to write lower page; rc = [%d]" | |
528 | "\n", rc); | |
529 | goto out; | |
237fead6 | 530 | } |
237fead6 | 531 | } |
96a7b9c2 | 532 | rc = 0; |
0216f7f7 | 533 | out: |
7fcba054 ES |
534 | if (enc_extent_page) { |
535 | kunmap(enc_extent_page); | |
536 | __free_page(enc_extent_page); | |
537 | } | |
0216f7f7 MH |
538 | return rc; |
539 | } | |
540 | ||
541 | static int ecryptfs_decrypt_extent(struct page *page, | |
542 | struct ecryptfs_crypt_stat *crypt_stat, | |
543 | struct page *enc_extent_page, | |
544 | unsigned long extent_offset) | |
545 | { | |
d6a13c17 | 546 | loff_t extent_base; |
0216f7f7 MH |
547 | char extent_iv[ECRYPTFS_MAX_IV_BYTES]; |
548 | int rc; | |
549 | ||
d6a13c17 | 550 | extent_base = (((loff_t)page->index) |
0216f7f7 MH |
551 | * (PAGE_CACHE_SIZE / crypt_stat->extent_size)); |
552 | rc = ecryptfs_derive_iv(extent_iv, crypt_stat, | |
553 | (extent_base + extent_offset)); | |
237fead6 | 554 | if (rc) { |
888d57bb JP |
555 | ecryptfs_printk(KERN_ERR, "Error attempting to derive IV for " |
556 | "extent [0x%.16llx]; rc = [%d]\n", | |
557 | (unsigned long long)(extent_base + extent_offset), rc); | |
0216f7f7 MH |
558 | goto out; |
559 | } | |
0216f7f7 MH |
560 | rc = ecryptfs_decrypt_page_offset(crypt_stat, page, |
561 | (extent_offset | |
562 | * crypt_stat->extent_size), | |
563 | enc_extent_page, 0, | |
564 | crypt_stat->extent_size, extent_iv); | |
565 | if (rc < 0) { | |
566 | printk(KERN_ERR "%s: Error attempting to decrypt to page with " | |
567 | "page->index = [%ld], extent_offset = [%ld]; " | |
18d1dbf1 | 568 | "rc = [%d]\n", __func__, page->index, extent_offset, |
0216f7f7 MH |
569 | rc); |
570 | goto out; | |
571 | } | |
572 | rc = 0; | |
237fead6 MH |
573 | out: |
574 | return rc; | |
575 | } | |
576 | ||
577 | /** | |
578 | * ecryptfs_decrypt_page | |
0216f7f7 MH |
579 | * @page: Page mapped from the eCryptfs inode for the file; data read |
580 | * and decrypted from the lower file will be written into this | |
581 | * page | |
237fead6 MH |
582 | * |
583 | * Decrypt an eCryptfs page. This is done on a per-extent basis. Note | |
584 | * that eCryptfs pages may straddle the lower pages -- for instance, | |
585 | * if the file was created on a machine with an 8K page size | |
586 | * (resulting in an 8K header), and then the file is copied onto a | |
587 | * host with a 32K page size, then when reading page 0 of the eCryptfs | |
588 | * file, 24K of page 0 of the lower file will be read and decrypted, | |
589 | * and then 8K of page 1 of the lower file will be read and decrypted. | |
590 | * | |
591 | * Returns zero on success; negative on error | |
592 | */ | |
0216f7f7 | 593 | int ecryptfs_decrypt_page(struct page *page) |
237fead6 | 594 | { |
0216f7f7 | 595 | struct inode *ecryptfs_inode; |
237fead6 | 596 | struct ecryptfs_crypt_stat *crypt_stat; |
7fcba054 ES |
597 | char *enc_extent_virt; |
598 | struct page *enc_extent_page = NULL; | |
0216f7f7 | 599 | unsigned long extent_offset; |
237fead6 | 600 | int rc = 0; |
237fead6 | 601 | |
0216f7f7 MH |
602 | ecryptfs_inode = page->mapping->host; |
603 | crypt_stat = | |
604 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); | |
13a791b4 | 605 | BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)); |
7fcba054 ES |
606 | enc_extent_page = alloc_page(GFP_USER); |
607 | if (!enc_extent_page) { | |
237fead6 | 608 | rc = -ENOMEM; |
0216f7f7 MH |
609 | ecryptfs_printk(KERN_ERR, "Error allocating memory for " |
610 | "encrypted extent\n"); | |
16a72c45 | 611 | goto out; |
237fead6 | 612 | } |
7fcba054 | 613 | enc_extent_virt = kmap(enc_extent_page); |
0216f7f7 MH |
614 | for (extent_offset = 0; |
615 | extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); | |
616 | extent_offset++) { | |
617 | loff_t offset; | |
618 | ||
619 | ecryptfs_lower_offset_for_extent( | |
620 | &offset, ((page->index * (PAGE_CACHE_SIZE | |
621 | / crypt_stat->extent_size)) | |
622 | + extent_offset), crypt_stat); | |
623 | rc = ecryptfs_read_lower(enc_extent_virt, offset, | |
624 | crypt_stat->extent_size, | |
625 | ecryptfs_inode); | |
96a7b9c2 | 626 | if (rc < 0) { |
0216f7f7 MH |
627 | ecryptfs_printk(KERN_ERR, "Error attempting " |
628 | "to read lower page; rc = [%d]" | |
629 | "\n", rc); | |
16a72c45 | 630 | goto out; |
237fead6 | 631 | } |
0216f7f7 MH |
632 | rc = ecryptfs_decrypt_extent(page, crypt_stat, enc_extent_page, |
633 | extent_offset); | |
634 | if (rc) { | |
635 | printk(KERN_ERR "%s: Error encrypting extent; " | |
18d1dbf1 | 636 | "rc = [%d]\n", __func__, rc); |
16a72c45 | 637 | goto out; |
237fead6 | 638 | } |
237fead6 MH |
639 | } |
640 | out: | |
7fcba054 ES |
641 | if (enc_extent_page) { |
642 | kunmap(enc_extent_page); | |
643 | __free_page(enc_extent_page); | |
644 | } | |
237fead6 MH |
645 | return rc; |
646 | } | |
647 | ||
648 | /** | |
649 | * decrypt_scatterlist | |
22e78faf MH |
650 | * @crypt_stat: Cryptographic context |
651 | * @dest_sg: The destination scatterlist to decrypt into | |
652 | * @src_sg: The source scatterlist to decrypt from | |
653 | * @size: The number of bytes to decrypt | |
654 | * @iv: The initialization vector to use for the decryption | |
237fead6 MH |
655 | * |
656 | * Returns the number of bytes decrypted; negative value on error | |
657 | */ | |
658 | static int decrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, | |
659 | struct scatterlist *dest_sg, | |
660 | struct scatterlist *src_sg, int size, | |
661 | unsigned char *iv) | |
662 | { | |
4dfea4f0 TH |
663 | struct ablkcipher_request *req = NULL; |
664 | struct extent_crypt_result ecr; | |
237fead6 MH |
665 | int rc = 0; |
666 | ||
4dfea4f0 TH |
667 | BUG_ON(!crypt_stat || !crypt_stat->tfm |
668 | || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)); | |
669 | if (unlikely(ecryptfs_verbosity > 0)) { | |
670 | ecryptfs_printk(KERN_DEBUG, "Key size [%zd]; key:\n", | |
671 | crypt_stat->key_size); | |
672 | ecryptfs_dump_hex(crypt_stat->key, | |
673 | crypt_stat->key_size); | |
674 | } | |
675 | ||
676 | init_completion(&ecr.completion); | |
677 | ||
237fead6 | 678 | mutex_lock(&crypt_stat->cs_tfm_mutex); |
4dfea4f0 TH |
679 | req = ablkcipher_request_alloc(crypt_stat->tfm, GFP_NOFS); |
680 | if (!req) { | |
237fead6 | 681 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
4dfea4f0 | 682 | rc = -ENOMEM; |
237fead6 MH |
683 | goto out; |
684 | } | |
4dfea4f0 TH |
685 | |
686 | ablkcipher_request_set_callback(req, | |
687 | CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, | |
688 | extent_crypt_complete, &ecr); | |
689 | /* Consider doing this once, when the file is opened */ | |
690 | if (!(crypt_stat->flags & ECRYPTFS_KEY_SET)) { | |
691 | rc = crypto_ablkcipher_setkey(crypt_stat->tfm, crypt_stat->key, | |
692 | crypt_stat->key_size); | |
693 | if (rc) { | |
694 | ecryptfs_printk(KERN_ERR, | |
695 | "Error setting key; rc = [%d]\n", | |
696 | rc); | |
697 | mutex_unlock(&crypt_stat->cs_tfm_mutex); | |
698 | rc = -EINVAL; | |
699 | goto out; | |
700 | } | |
701 | crypt_stat->flags |= ECRYPTFS_KEY_SET; | |
702 | } | |
237fead6 | 703 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
4dfea4f0 TH |
704 | ecryptfs_printk(KERN_DEBUG, "Decrypting [%d] bytes.\n", size); |
705 | ablkcipher_request_set_crypt(req, src_sg, dest_sg, size, iv); | |
706 | rc = crypto_ablkcipher_decrypt(req); | |
707 | if (rc == -EINPROGRESS || rc == -EBUSY) { | |
708 | struct extent_crypt_result *ecr = req->base.data; | |
709 | ||
710 | wait_for_completion(&ecr->completion); | |
711 | rc = ecr->rc; | |
712 | INIT_COMPLETION(ecr->completion); | |
237fead6 | 713 | } |
237fead6 | 714 | out: |
4dfea4f0 | 715 | ablkcipher_request_free(req); |
237fead6 | 716 | return rc; |
4dfea4f0 | 717 | |
237fead6 MH |
718 | } |
719 | ||
720 | /** | |
721 | * ecryptfs_encrypt_page_offset | |
22e78faf MH |
722 | * @crypt_stat: The cryptographic context |
723 | * @dst_page: The page to encrypt into | |
724 | * @dst_offset: The offset in the page to encrypt into | |
725 | * @src_page: The page to encrypt from | |
726 | * @src_offset: The offset in the page to encrypt from | |
727 | * @size: The number of bytes to encrypt | |
728 | * @iv: The initialization vector to use for the encryption | |
237fead6 MH |
729 | * |
730 | * Returns the number of bytes encrypted | |
731 | */ | |
732 | static int | |
733 | ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
734 | struct page *dst_page, int dst_offset, | |
735 | struct page *src_page, int src_offset, int size, | |
736 | unsigned char *iv) | |
737 | { | |
738 | struct scatterlist src_sg, dst_sg; | |
739 | ||
60c74f81 JA |
740 | sg_init_table(&src_sg, 1); |
741 | sg_init_table(&dst_sg, 1); | |
742 | ||
642f1490 JA |
743 | sg_set_page(&src_sg, src_page, size, src_offset); |
744 | sg_set_page(&dst_sg, dst_page, size, dst_offset); | |
237fead6 MH |
745 | return encrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); |
746 | } | |
747 | ||
748 | /** | |
749 | * ecryptfs_decrypt_page_offset | |
22e78faf MH |
750 | * @crypt_stat: The cryptographic context |
751 | * @dst_page: The page to decrypt into | |
752 | * @dst_offset: The offset in the page to decrypt into | |
753 | * @src_page: The page to decrypt from | |
754 | * @src_offset: The offset in the page to decrypt from | |
755 | * @size: The number of bytes to decrypt | |
756 | * @iv: The initialization vector to use for the decryption | |
237fead6 MH |
757 | * |
758 | * Returns the number of bytes decrypted | |
759 | */ | |
760 | static int | |
761 | ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
762 | struct page *dst_page, int dst_offset, | |
763 | struct page *src_page, int src_offset, int size, | |
764 | unsigned char *iv) | |
765 | { | |
766 | struct scatterlist src_sg, dst_sg; | |
767 | ||
60c74f81 | 768 | sg_init_table(&src_sg, 1); |
642f1490 JA |
769 | sg_set_page(&src_sg, src_page, size, src_offset); |
770 | ||
60c74f81 | 771 | sg_init_table(&dst_sg, 1); |
642f1490 | 772 | sg_set_page(&dst_sg, dst_page, size, dst_offset); |
60c74f81 | 773 | |
237fead6 MH |
774 | return decrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); |
775 | } | |
776 | ||
777 | #define ECRYPTFS_MAX_SCATTERLIST_LEN 4 | |
778 | ||
779 | /** | |
780 | * ecryptfs_init_crypt_ctx | |
421f91d2 | 781 | * @crypt_stat: Uninitialized crypt stats structure |
237fead6 MH |
782 | * |
783 | * Initialize the crypto context. | |
784 | * | |
785 | * TODO: Performance: Keep a cache of initialized cipher contexts; | |
786 | * only init if needed | |
787 | */ | |
788 | int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat) | |
789 | { | |
8bba066f | 790 | char *full_alg_name; |
237fead6 MH |
791 | int rc = -EINVAL; |
792 | ||
793 | if (!crypt_stat->cipher) { | |
794 | ecryptfs_printk(KERN_ERR, "No cipher specified\n"); | |
795 | goto out; | |
796 | } | |
797 | ecryptfs_printk(KERN_DEBUG, | |
798 | "Initializing cipher [%s]; strlen = [%d]; " | |
f24b3887 | 799 | "key_size_bits = [%zd]\n", |
237fead6 MH |
800 | crypt_stat->cipher, (int)strlen(crypt_stat->cipher), |
801 | crypt_stat->key_size << 3); | |
802 | if (crypt_stat->tfm) { | |
803 | rc = 0; | |
804 | goto out; | |
805 | } | |
806 | mutex_lock(&crypt_stat->cs_tfm_mutex); | |
8bba066f MH |
807 | rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, |
808 | crypt_stat->cipher, "cbc"); | |
809 | if (rc) | |
c8161f64 | 810 | goto out_unlock; |
4dfea4f0 | 811 | crypt_stat->tfm = crypto_alloc_ablkcipher(full_alg_name, 0, 0); |
8bba066f | 812 | kfree(full_alg_name); |
de88777e AM |
813 | if (IS_ERR(crypt_stat->tfm)) { |
814 | rc = PTR_ERR(crypt_stat->tfm); | |
b0105eae | 815 | crypt_stat->tfm = NULL; |
237fead6 MH |
816 | ecryptfs_printk(KERN_ERR, "cryptfs: init_crypt_ctx(): " |
817 | "Error initializing cipher [%s]\n", | |
818 | crypt_stat->cipher); | |
c8161f64 | 819 | goto out_unlock; |
237fead6 | 820 | } |
4dfea4f0 | 821 | crypto_ablkcipher_set_flags(crypt_stat->tfm, CRYPTO_TFM_REQ_WEAK_KEY); |
237fead6 | 822 | rc = 0; |
c8161f64 ES |
823 | out_unlock: |
824 | mutex_unlock(&crypt_stat->cs_tfm_mutex); | |
237fead6 MH |
825 | out: |
826 | return rc; | |
827 | } | |
828 | ||
829 | static void set_extent_mask_and_shift(struct ecryptfs_crypt_stat *crypt_stat) | |
830 | { | |
831 | int extent_size_tmp; | |
832 | ||
833 | crypt_stat->extent_mask = 0xFFFFFFFF; | |
834 | crypt_stat->extent_shift = 0; | |
835 | if (crypt_stat->extent_size == 0) | |
836 | return; | |
837 | extent_size_tmp = crypt_stat->extent_size; | |
838 | while ((extent_size_tmp & 0x01) == 0) { | |
839 | extent_size_tmp >>= 1; | |
840 | crypt_stat->extent_mask <<= 1; | |
841 | crypt_stat->extent_shift++; | |
842 | } | |
843 | } | |
844 | ||
845 | void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat) | |
846 | { | |
847 | /* Default values; may be overwritten as we are parsing the | |
848 | * packets. */ | |
849 | crypt_stat->extent_size = ECRYPTFS_DEFAULT_EXTENT_SIZE; | |
850 | set_extent_mask_and_shift(crypt_stat); | |
851 | crypt_stat->iv_bytes = ECRYPTFS_DEFAULT_IV_BYTES; | |
dd2a3b7a | 852 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
fa3ef1cb | 853 | crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; |
45eaab79 MH |
854 | else { |
855 | if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE) | |
fa3ef1cb | 856 | crypt_stat->metadata_size = |
cc11beff | 857 | ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; |
45eaab79 | 858 | else |
fa3ef1cb | 859 | crypt_stat->metadata_size = PAGE_CACHE_SIZE; |
45eaab79 | 860 | } |
237fead6 MH |
861 | } |
862 | ||
863 | /** | |
864 | * ecryptfs_compute_root_iv | |
865 | * @crypt_stats | |
866 | * | |
867 | * On error, sets the root IV to all 0's. | |
868 | */ | |
869 | int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat) | |
870 | { | |
871 | int rc = 0; | |
872 | char dst[MD5_DIGEST_SIZE]; | |
873 | ||
874 | BUG_ON(crypt_stat->iv_bytes > MD5_DIGEST_SIZE); | |
875 | BUG_ON(crypt_stat->iv_bytes <= 0); | |
e2bd99ec | 876 | if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { |
237fead6 MH |
877 | rc = -EINVAL; |
878 | ecryptfs_printk(KERN_WARNING, "Session key not valid; " | |
879 | "cannot generate root IV\n"); | |
880 | goto out; | |
881 | } | |
882 | rc = ecryptfs_calculate_md5(dst, crypt_stat, crypt_stat->key, | |
883 | crypt_stat->key_size); | |
884 | if (rc) { | |
885 | ecryptfs_printk(KERN_WARNING, "Error attempting to compute " | |
886 | "MD5 while generating root IV\n"); | |
887 | goto out; | |
888 | } | |
889 | memcpy(crypt_stat->root_iv, dst, crypt_stat->iv_bytes); | |
890 | out: | |
891 | if (rc) { | |
892 | memset(crypt_stat->root_iv, 0, crypt_stat->iv_bytes); | |
e2bd99ec | 893 | crypt_stat->flags |= ECRYPTFS_SECURITY_WARNING; |
237fead6 MH |
894 | } |
895 | return rc; | |
896 | } | |
897 | ||
898 | static void ecryptfs_generate_new_key(struct ecryptfs_crypt_stat *crypt_stat) | |
899 | { | |
900 | get_random_bytes(crypt_stat->key, crypt_stat->key_size); | |
e2bd99ec | 901 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; |
237fead6 MH |
902 | ecryptfs_compute_root_iv(crypt_stat); |
903 | if (unlikely(ecryptfs_verbosity > 0)) { | |
904 | ecryptfs_printk(KERN_DEBUG, "Generated new session key:\n"); | |
905 | ecryptfs_dump_hex(crypt_stat->key, | |
906 | crypt_stat->key_size); | |
907 | } | |
908 | } | |
909 | ||
17398957 MH |
910 | /** |
911 | * ecryptfs_copy_mount_wide_flags_to_inode_flags | |
22e78faf MH |
912 | * @crypt_stat: The inode's cryptographic context |
913 | * @mount_crypt_stat: The mount point's cryptographic context | |
17398957 MH |
914 | * |
915 | * This function propagates the mount-wide flags to individual inode | |
916 | * flags. | |
917 | */ | |
918 | static void ecryptfs_copy_mount_wide_flags_to_inode_flags( | |
919 | struct ecryptfs_crypt_stat *crypt_stat, | |
920 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
921 | { | |
922 | if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) | |
923 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; | |
924 | if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) | |
925 | crypt_stat->flags |= ECRYPTFS_VIEW_AS_ENCRYPTED; | |
addd65ad MH |
926 | if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) { |
927 | crypt_stat->flags |= ECRYPTFS_ENCRYPT_FILENAMES; | |
928 | if (mount_crypt_stat->flags | |
929 | & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK) | |
930 | crypt_stat->flags |= ECRYPTFS_ENCFN_USE_MOUNT_FNEK; | |
931 | else if (mount_crypt_stat->flags | |
932 | & ECRYPTFS_GLOBAL_ENCFN_USE_FEK) | |
933 | crypt_stat->flags |= ECRYPTFS_ENCFN_USE_FEK; | |
934 | } | |
17398957 MH |
935 | } |
936 | ||
f4aad16a MH |
937 | static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs( |
938 | struct ecryptfs_crypt_stat *crypt_stat, | |
939 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
940 | { | |
941 | struct ecryptfs_global_auth_tok *global_auth_tok; | |
942 | int rc = 0; | |
943 | ||
aa06117f | 944 | mutex_lock(&crypt_stat->keysig_list_mutex); |
f4aad16a | 945 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); |
aa06117f | 946 | |
f4aad16a MH |
947 | list_for_each_entry(global_auth_tok, |
948 | &mount_crypt_stat->global_auth_tok_list, | |
949 | mount_crypt_stat_list) { | |
84814d64 TH |
950 | if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_FNEK) |
951 | continue; | |
f4aad16a MH |
952 | rc = ecryptfs_add_keysig(crypt_stat, global_auth_tok->sig); |
953 | if (rc) { | |
954 | printk(KERN_ERR "Error adding keysig; rc = [%d]\n", rc); | |
f4aad16a MH |
955 | goto out; |
956 | } | |
957 | } | |
aa06117f | 958 | |
f4aad16a | 959 | out: |
aa06117f RD |
960 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); |
961 | mutex_unlock(&crypt_stat->keysig_list_mutex); | |
f4aad16a MH |
962 | return rc; |
963 | } | |
964 | ||
237fead6 MH |
965 | /** |
966 | * ecryptfs_set_default_crypt_stat_vals | |
22e78faf MH |
967 | * @crypt_stat: The inode's cryptographic context |
968 | * @mount_crypt_stat: The mount point's cryptographic context | |
237fead6 MH |
969 | * |
970 | * Default values in the event that policy does not override them. | |
971 | */ | |
972 | static void ecryptfs_set_default_crypt_stat_vals( | |
973 | struct ecryptfs_crypt_stat *crypt_stat, | |
974 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
975 | { | |
17398957 MH |
976 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
977 | mount_crypt_stat); | |
237fead6 MH |
978 | ecryptfs_set_default_sizes(crypt_stat); |
979 | strcpy(crypt_stat->cipher, ECRYPTFS_DEFAULT_CIPHER); | |
980 | crypt_stat->key_size = ECRYPTFS_DEFAULT_KEY_BYTES; | |
e2bd99ec | 981 | crypt_stat->flags &= ~(ECRYPTFS_KEY_VALID); |
237fead6 MH |
982 | crypt_stat->file_version = ECRYPTFS_FILE_VERSION; |
983 | crypt_stat->mount_crypt_stat = mount_crypt_stat; | |
984 | } | |
985 | ||
986 | /** | |
987 | * ecryptfs_new_file_context | |
b59db43a | 988 | * @ecryptfs_inode: The eCryptfs inode |
237fead6 MH |
989 | * |
990 | * If the crypto context for the file has not yet been established, | |
991 | * this is where we do that. Establishing a new crypto context | |
992 | * involves the following decisions: | |
993 | * - What cipher to use? | |
994 | * - What set of authentication tokens to use? | |
995 | * Here we just worry about getting enough information into the | |
996 | * authentication tokens so that we know that they are available. | |
997 | * We associate the available authentication tokens with the new file | |
998 | * via the set of signatures in the crypt_stat struct. Later, when | |
999 | * the headers are actually written out, we may again defer to | |
1000 | * userspace to perform the encryption of the session key; for the | |
1001 | * foreseeable future, this will be the case with public key packets. | |
1002 | * | |
1003 | * Returns zero on success; non-zero otherwise | |
1004 | */ | |
b59db43a | 1005 | int ecryptfs_new_file_context(struct inode *ecryptfs_inode) |
237fead6 | 1006 | { |
237fead6 | 1007 | struct ecryptfs_crypt_stat *crypt_stat = |
b59db43a | 1008 | &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
237fead6 MH |
1009 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
1010 | &ecryptfs_superblock_to_private( | |
b59db43a | 1011 | ecryptfs_inode->i_sb)->mount_crypt_stat; |
237fead6 | 1012 | int cipher_name_len; |
f4aad16a | 1013 | int rc = 0; |
237fead6 MH |
1014 | |
1015 | ecryptfs_set_default_crypt_stat_vals(crypt_stat, mount_crypt_stat); | |
af655dc6 | 1016 | crypt_stat->flags |= (ECRYPTFS_ENCRYPTED | ECRYPTFS_KEY_VALID); |
f4aad16a MH |
1017 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
1018 | mount_crypt_stat); | |
1019 | rc = ecryptfs_copy_mount_wide_sigs_to_inode_sigs(crypt_stat, | |
1020 | mount_crypt_stat); | |
1021 | if (rc) { | |
1022 | printk(KERN_ERR "Error attempting to copy mount-wide key sigs " | |
1023 | "to the inode key sigs; rc = [%d]\n", rc); | |
1024 | goto out; | |
1025 | } | |
1026 | cipher_name_len = | |
1027 | strlen(mount_crypt_stat->global_default_cipher_name); | |
1028 | memcpy(crypt_stat->cipher, | |
1029 | mount_crypt_stat->global_default_cipher_name, | |
1030 | cipher_name_len); | |
1031 | crypt_stat->cipher[cipher_name_len] = '\0'; | |
1032 | crypt_stat->key_size = | |
1033 | mount_crypt_stat->global_default_cipher_key_size; | |
1034 | ecryptfs_generate_new_key(crypt_stat); | |
237fead6 MH |
1035 | rc = ecryptfs_init_crypt_ctx(crypt_stat); |
1036 | if (rc) | |
1037 | ecryptfs_printk(KERN_ERR, "Error initializing cryptographic " | |
1038 | "context for cipher [%s]: rc = [%d]\n", | |
1039 | crypt_stat->cipher, rc); | |
f4aad16a | 1040 | out: |
237fead6 MH |
1041 | return rc; |
1042 | } | |
1043 | ||
1044 | /** | |
7a86617e | 1045 | * ecryptfs_validate_marker - check for the ecryptfs marker |
237fead6 MH |
1046 | * @data: The data block in which to check |
1047 | * | |
7a86617e | 1048 | * Returns zero if marker found; -EINVAL if not found |
237fead6 | 1049 | */ |
7a86617e | 1050 | static int ecryptfs_validate_marker(char *data) |
237fead6 MH |
1051 | { |
1052 | u32 m_1, m_2; | |
1053 | ||
29335c6a HH |
1054 | m_1 = get_unaligned_be32(data); |
1055 | m_2 = get_unaligned_be32(data + 4); | |
237fead6 | 1056 | if ((m_1 ^ MAGIC_ECRYPTFS_MARKER) == m_2) |
7a86617e | 1057 | return 0; |
237fead6 MH |
1058 | ecryptfs_printk(KERN_DEBUG, "m_1 = [0x%.8x]; m_2 = [0x%.8x]; " |
1059 | "MAGIC_ECRYPTFS_MARKER = [0x%.8x]\n", m_1, m_2, | |
1060 | MAGIC_ECRYPTFS_MARKER); | |
1061 | ecryptfs_printk(KERN_DEBUG, "(m_1 ^ MAGIC_ECRYPTFS_MARKER) = " | |
1062 | "[0x%.8x]\n", (m_1 ^ MAGIC_ECRYPTFS_MARKER)); | |
7a86617e | 1063 | return -EINVAL; |
237fead6 MH |
1064 | } |
1065 | ||
1066 | struct ecryptfs_flag_map_elem { | |
1067 | u32 file_flag; | |
1068 | u32 local_flag; | |
1069 | }; | |
1070 | ||
1071 | /* Add support for additional flags by adding elements here. */ | |
1072 | static struct ecryptfs_flag_map_elem ecryptfs_flag_map[] = { | |
1073 | {0x00000001, ECRYPTFS_ENABLE_HMAC}, | |
dd2a3b7a | 1074 | {0x00000002, ECRYPTFS_ENCRYPTED}, |
addd65ad MH |
1075 | {0x00000004, ECRYPTFS_METADATA_IN_XATTR}, |
1076 | {0x00000008, ECRYPTFS_ENCRYPT_FILENAMES} | |
237fead6 MH |
1077 | }; |
1078 | ||
1079 | /** | |
1080 | * ecryptfs_process_flags | |
22e78faf | 1081 | * @crypt_stat: The cryptographic context |
237fead6 MH |
1082 | * @page_virt: Source data to be parsed |
1083 | * @bytes_read: Updated with the number of bytes read | |
1084 | * | |
1085 | * Returns zero on success; non-zero if the flag set is invalid | |
1086 | */ | |
1087 | static int ecryptfs_process_flags(struct ecryptfs_crypt_stat *crypt_stat, | |
1088 | char *page_virt, int *bytes_read) | |
1089 | { | |
1090 | int rc = 0; | |
1091 | int i; | |
1092 | u32 flags; | |
1093 | ||
29335c6a | 1094 | flags = get_unaligned_be32(page_virt); |
237fead6 MH |
1095 | for (i = 0; i < ((sizeof(ecryptfs_flag_map) |
1096 | / sizeof(struct ecryptfs_flag_map_elem))); i++) | |
1097 | if (flags & ecryptfs_flag_map[i].file_flag) { | |
e2bd99ec | 1098 | crypt_stat->flags |= ecryptfs_flag_map[i].local_flag; |
237fead6 | 1099 | } else |
e2bd99ec | 1100 | crypt_stat->flags &= ~(ecryptfs_flag_map[i].local_flag); |
237fead6 MH |
1101 | /* Version is in top 8 bits of the 32-bit flag vector */ |
1102 | crypt_stat->file_version = ((flags >> 24) & 0xFF); | |
1103 | (*bytes_read) = 4; | |
1104 | return rc; | |
1105 | } | |
1106 | ||
1107 | /** | |
1108 | * write_ecryptfs_marker | |
1109 | * @page_virt: The pointer to in a page to begin writing the marker | |
1110 | * @written: Number of bytes written | |
1111 | * | |
1112 | * Marker = 0x3c81b7f5 | |
1113 | */ | |
1114 | static void write_ecryptfs_marker(char *page_virt, size_t *written) | |
1115 | { | |
1116 | u32 m_1, m_2; | |
1117 | ||
1118 | get_random_bytes(&m_1, (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); | |
1119 | m_2 = (m_1 ^ MAGIC_ECRYPTFS_MARKER); | |
29335c6a HH |
1120 | put_unaligned_be32(m_1, page_virt); |
1121 | page_virt += (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2); | |
1122 | put_unaligned_be32(m_2, page_virt); | |
237fead6 MH |
1123 | (*written) = MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; |
1124 | } | |
1125 | ||
f4e60e6b TH |
1126 | void ecryptfs_write_crypt_stat_flags(char *page_virt, |
1127 | struct ecryptfs_crypt_stat *crypt_stat, | |
1128 | size_t *written) | |
237fead6 MH |
1129 | { |
1130 | u32 flags = 0; | |
1131 | int i; | |
1132 | ||
1133 | for (i = 0; i < ((sizeof(ecryptfs_flag_map) | |
1134 | / sizeof(struct ecryptfs_flag_map_elem))); i++) | |
e2bd99ec | 1135 | if (crypt_stat->flags & ecryptfs_flag_map[i].local_flag) |
237fead6 MH |
1136 | flags |= ecryptfs_flag_map[i].file_flag; |
1137 | /* Version is in top 8 bits of the 32-bit flag vector */ | |
1138 | flags |= ((((u8)crypt_stat->file_version) << 24) & 0xFF000000); | |
29335c6a | 1139 | put_unaligned_be32(flags, page_virt); |
237fead6 MH |
1140 | (*written) = 4; |
1141 | } | |
1142 | ||
1143 | struct ecryptfs_cipher_code_str_map_elem { | |
1144 | char cipher_str[16]; | |
19e66a67 | 1145 | u8 cipher_code; |
237fead6 MH |
1146 | }; |
1147 | ||
1148 | /* Add support for additional ciphers by adding elements here. The | |
1149 | * cipher_code is whatever OpenPGP applicatoins use to identify the | |
1150 | * ciphers. List in order of probability. */ | |
1151 | static struct ecryptfs_cipher_code_str_map_elem | |
1152 | ecryptfs_cipher_code_str_map[] = { | |
1153 | {"aes",RFC2440_CIPHER_AES_128 }, | |
1154 | {"blowfish", RFC2440_CIPHER_BLOWFISH}, | |
1155 | {"des3_ede", RFC2440_CIPHER_DES3_EDE}, | |
1156 | {"cast5", RFC2440_CIPHER_CAST_5}, | |
1157 | {"twofish", RFC2440_CIPHER_TWOFISH}, | |
1158 | {"cast6", RFC2440_CIPHER_CAST_6}, | |
1159 | {"aes", RFC2440_CIPHER_AES_192}, | |
1160 | {"aes", RFC2440_CIPHER_AES_256} | |
1161 | }; | |
1162 | ||
1163 | /** | |
1164 | * ecryptfs_code_for_cipher_string | |
9c79f34f MH |
1165 | * @cipher_name: The string alias for the cipher |
1166 | * @key_bytes: Length of key in bytes; used for AES code selection | |
237fead6 MH |
1167 | * |
1168 | * Returns zero on no match, or the cipher code on match | |
1169 | */ | |
9c79f34f | 1170 | u8 ecryptfs_code_for_cipher_string(char *cipher_name, size_t key_bytes) |
237fead6 MH |
1171 | { |
1172 | int i; | |
19e66a67 | 1173 | u8 code = 0; |
237fead6 MH |
1174 | struct ecryptfs_cipher_code_str_map_elem *map = |
1175 | ecryptfs_cipher_code_str_map; | |
1176 | ||
9c79f34f MH |
1177 | if (strcmp(cipher_name, "aes") == 0) { |
1178 | switch (key_bytes) { | |
237fead6 MH |
1179 | case 16: |
1180 | code = RFC2440_CIPHER_AES_128; | |
1181 | break; | |
1182 | case 24: | |
1183 | code = RFC2440_CIPHER_AES_192; | |
1184 | break; | |
1185 | case 32: | |
1186 | code = RFC2440_CIPHER_AES_256; | |
1187 | } | |
1188 | } else { | |
1189 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++) | |
9c79f34f | 1190 | if (strcmp(cipher_name, map[i].cipher_str) == 0) { |
237fead6 MH |
1191 | code = map[i].cipher_code; |
1192 | break; | |
1193 | } | |
1194 | } | |
1195 | return code; | |
1196 | } | |
1197 | ||
1198 | /** | |
1199 | * ecryptfs_cipher_code_to_string | |
1200 | * @str: Destination to write out the cipher name | |
1201 | * @cipher_code: The code to convert to cipher name string | |
1202 | * | |
1203 | * Returns zero on success | |
1204 | */ | |
19e66a67 | 1205 | int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code) |
237fead6 MH |
1206 | { |
1207 | int rc = 0; | |
1208 | int i; | |
1209 | ||
1210 | str[0] = '\0'; | |
1211 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++) | |
1212 | if (cipher_code == ecryptfs_cipher_code_str_map[i].cipher_code) | |
1213 | strcpy(str, ecryptfs_cipher_code_str_map[i].cipher_str); | |
1214 | if (str[0] == '\0') { | |
1215 | ecryptfs_printk(KERN_WARNING, "Cipher code not recognized: " | |
1216 | "[%d]\n", cipher_code); | |
1217 | rc = -EINVAL; | |
1218 | } | |
1219 | return rc; | |
1220 | } | |
1221 | ||
778aeb42 | 1222 | int ecryptfs_read_and_validate_header_region(struct inode *inode) |
dd2a3b7a | 1223 | { |
778aeb42 TH |
1224 | u8 file_size[ECRYPTFS_SIZE_AND_MARKER_BYTES]; |
1225 | u8 *marker = file_size + ECRYPTFS_FILE_SIZE_BYTES; | |
dd2a3b7a MH |
1226 | int rc; |
1227 | ||
778aeb42 TH |
1228 | rc = ecryptfs_read_lower(file_size, 0, ECRYPTFS_SIZE_AND_MARKER_BYTES, |
1229 | inode); | |
1230 | if (rc < ECRYPTFS_SIZE_AND_MARKER_BYTES) | |
1231 | return rc >= 0 ? -EINVAL : rc; | |
1232 | rc = ecryptfs_validate_marker(marker); | |
1233 | if (!rc) | |
1234 | ecryptfs_i_size_init(file_size, inode); | |
dd2a3b7a MH |
1235 | return rc; |
1236 | } | |
1237 | ||
e77a56dd MH |
1238 | void |
1239 | ecryptfs_write_header_metadata(char *virt, | |
1240 | struct ecryptfs_crypt_stat *crypt_stat, | |
1241 | size_t *written) | |
237fead6 MH |
1242 | { |
1243 | u32 header_extent_size; | |
1244 | u16 num_header_extents_at_front; | |
1245 | ||
45eaab79 | 1246 | header_extent_size = (u32)crypt_stat->extent_size; |
237fead6 | 1247 | num_header_extents_at_front = |
fa3ef1cb | 1248 | (u16)(crypt_stat->metadata_size / crypt_stat->extent_size); |
29335c6a | 1249 | put_unaligned_be32(header_extent_size, virt); |
237fead6 | 1250 | virt += 4; |
29335c6a | 1251 | put_unaligned_be16(num_header_extents_at_front, virt); |
237fead6 MH |
1252 | (*written) = 6; |
1253 | } | |
1254 | ||
30632870 | 1255 | struct kmem_cache *ecryptfs_header_cache; |
237fead6 MH |
1256 | |
1257 | /** | |
1258 | * ecryptfs_write_headers_virt | |
22e78faf | 1259 | * @page_virt: The virtual address to write the headers to |
87b811c3 | 1260 | * @max: The size of memory allocated at page_virt |
22e78faf MH |
1261 | * @size: Set to the number of bytes written by this function |
1262 | * @crypt_stat: The cryptographic context | |
1263 | * @ecryptfs_dentry: The eCryptfs dentry | |
237fead6 MH |
1264 | * |
1265 | * Format version: 1 | |
1266 | * | |
1267 | * Header Extent: | |
1268 | * Octets 0-7: Unencrypted file size (big-endian) | |
1269 | * Octets 8-15: eCryptfs special marker | |
1270 | * Octets 16-19: Flags | |
1271 | * Octet 16: File format version number (between 0 and 255) | |
1272 | * Octets 17-18: Reserved | |
1273 | * Octet 19: Bit 1 (lsb): Reserved | |
1274 | * Bit 2: Encrypted? | |
1275 | * Bits 3-8: Reserved | |
1276 | * Octets 20-23: Header extent size (big-endian) | |
1277 | * Octets 24-25: Number of header extents at front of file | |
1278 | * (big-endian) | |
1279 | * Octet 26: Begin RFC 2440 authentication token packet set | |
1280 | * Data Extent 0: | |
1281 | * Lower data (CBC encrypted) | |
1282 | * Data Extent 1: | |
1283 | * Lower data (CBC encrypted) | |
1284 | * ... | |
1285 | * | |
1286 | * Returns zero on success | |
1287 | */ | |
87b811c3 ES |
1288 | static int ecryptfs_write_headers_virt(char *page_virt, size_t max, |
1289 | size_t *size, | |
dd2a3b7a MH |
1290 | struct ecryptfs_crypt_stat *crypt_stat, |
1291 | struct dentry *ecryptfs_dentry) | |
237fead6 MH |
1292 | { |
1293 | int rc; | |
1294 | size_t written; | |
1295 | size_t offset; | |
1296 | ||
1297 | offset = ECRYPTFS_FILE_SIZE_BYTES; | |
1298 | write_ecryptfs_marker((page_virt + offset), &written); | |
1299 | offset += written; | |
f4e60e6b TH |
1300 | ecryptfs_write_crypt_stat_flags((page_virt + offset), crypt_stat, |
1301 | &written); | |
237fead6 | 1302 | offset += written; |
e77a56dd MH |
1303 | ecryptfs_write_header_metadata((page_virt + offset), crypt_stat, |
1304 | &written); | |
237fead6 MH |
1305 | offset += written; |
1306 | rc = ecryptfs_generate_key_packet_set((page_virt + offset), crypt_stat, | |
1307 | ecryptfs_dentry, &written, | |
87b811c3 | 1308 | max - offset); |
237fead6 MH |
1309 | if (rc) |
1310 | ecryptfs_printk(KERN_WARNING, "Error generating key packet " | |
1311 | "set; rc = [%d]\n", rc); | |
dd2a3b7a MH |
1312 | if (size) { |
1313 | offset += written; | |
1314 | *size = offset; | |
1315 | } | |
1316 | return rc; | |
1317 | } | |
1318 | ||
22e78faf | 1319 | static int |
b59db43a | 1320 | ecryptfs_write_metadata_to_contents(struct inode *ecryptfs_inode, |
8faece5f | 1321 | char *virt, size_t virt_len) |
dd2a3b7a | 1322 | { |
d7cdc5fe | 1323 | int rc; |
dd2a3b7a | 1324 | |
b59db43a | 1325 | rc = ecryptfs_write_lower(ecryptfs_inode, virt, |
8faece5f | 1326 | 0, virt_len); |
96a7b9c2 | 1327 | if (rc < 0) |
d7cdc5fe | 1328 | printk(KERN_ERR "%s: Error attempting to write header " |
96a7b9c2 TH |
1329 | "information to lower file; rc = [%d]\n", __func__, rc); |
1330 | else | |
1331 | rc = 0; | |
70456600 | 1332 | return rc; |
dd2a3b7a MH |
1333 | } |
1334 | ||
22e78faf MH |
1335 | static int |
1336 | ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, | |
22e78faf | 1337 | char *page_virt, size_t size) |
dd2a3b7a MH |
1338 | { |
1339 | int rc; | |
1340 | ||
1341 | rc = ecryptfs_setxattr(ecryptfs_dentry, ECRYPTFS_XATTR_NAME, page_virt, | |
1342 | size, 0); | |
237fead6 MH |
1343 | return rc; |
1344 | } | |
1345 | ||
8faece5f TH |
1346 | static unsigned long ecryptfs_get_zeroed_pages(gfp_t gfp_mask, |
1347 | unsigned int order) | |
1348 | { | |
1349 | struct page *page; | |
1350 | ||
1351 | page = alloc_pages(gfp_mask | __GFP_ZERO, order); | |
1352 | if (page) | |
1353 | return (unsigned long) page_address(page); | |
1354 | return 0; | |
1355 | } | |
1356 | ||
237fead6 | 1357 | /** |
dd2a3b7a | 1358 | * ecryptfs_write_metadata |
b59db43a TH |
1359 | * @ecryptfs_dentry: The eCryptfs dentry, which should be negative |
1360 | * @ecryptfs_inode: The newly created eCryptfs inode | |
237fead6 MH |
1361 | * |
1362 | * Write the file headers out. This will likely involve a userspace | |
1363 | * callout, in which the session key is encrypted with one or more | |
1364 | * public keys and/or the passphrase necessary to do the encryption is | |
1365 | * retrieved via a prompt. Exactly what happens at this point should | |
1366 | * be policy-dependent. | |
1367 | * | |
1368 | * Returns zero on success; non-zero on error | |
1369 | */ | |
b59db43a TH |
1370 | int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry, |
1371 | struct inode *ecryptfs_inode) | |
237fead6 | 1372 | { |
d7cdc5fe | 1373 | struct ecryptfs_crypt_stat *crypt_stat = |
b59db43a | 1374 | &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
8faece5f | 1375 | unsigned int order; |
cc11beff | 1376 | char *virt; |
8faece5f | 1377 | size_t virt_len; |
d7cdc5fe | 1378 | size_t size = 0; |
237fead6 MH |
1379 | int rc = 0; |
1380 | ||
e2bd99ec MH |
1381 | if (likely(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
1382 | if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { | |
d7cdc5fe | 1383 | printk(KERN_ERR "Key is invalid; bailing out\n"); |
237fead6 MH |
1384 | rc = -EINVAL; |
1385 | goto out; | |
1386 | } | |
1387 | } else { | |
cc11beff | 1388 | printk(KERN_WARNING "%s: Encrypted flag not set\n", |
18d1dbf1 | 1389 | __func__); |
237fead6 | 1390 | rc = -EINVAL; |
237fead6 MH |
1391 | goto out; |
1392 | } | |
fa3ef1cb | 1393 | virt_len = crypt_stat->metadata_size; |
8faece5f | 1394 | order = get_order(virt_len); |
237fead6 | 1395 | /* Released in this function */ |
8faece5f | 1396 | virt = (char *)ecryptfs_get_zeroed_pages(GFP_KERNEL, order); |
cc11beff | 1397 | if (!virt) { |
18d1dbf1 | 1398 | printk(KERN_ERR "%s: Out of memory\n", __func__); |
237fead6 MH |
1399 | rc = -ENOMEM; |
1400 | goto out; | |
1401 | } | |
bd4f0fe8 | 1402 | /* Zeroed page ensures the in-header unencrypted i_size is set to 0 */ |
8faece5f TH |
1403 | rc = ecryptfs_write_headers_virt(virt, virt_len, &size, crypt_stat, |
1404 | ecryptfs_dentry); | |
237fead6 | 1405 | if (unlikely(rc)) { |
cc11beff | 1406 | printk(KERN_ERR "%s: Error whilst writing headers; rc = [%d]\n", |
18d1dbf1 | 1407 | __func__, rc); |
237fead6 MH |
1408 | goto out_free; |
1409 | } | |
dd2a3b7a | 1410 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
8faece5f TH |
1411 | rc = ecryptfs_write_metadata_to_xattr(ecryptfs_dentry, virt, |
1412 | size); | |
dd2a3b7a | 1413 | else |
b59db43a | 1414 | rc = ecryptfs_write_metadata_to_contents(ecryptfs_inode, virt, |
8faece5f | 1415 | virt_len); |
dd2a3b7a | 1416 | if (rc) { |
cc11beff | 1417 | printk(KERN_ERR "%s: Error writing metadata out to lower file; " |
18d1dbf1 | 1418 | "rc = [%d]\n", __func__, rc); |
dd2a3b7a | 1419 | goto out_free; |
237fead6 | 1420 | } |
237fead6 | 1421 | out_free: |
8faece5f | 1422 | free_pages((unsigned long)virt, order); |
237fead6 MH |
1423 | out: |
1424 | return rc; | |
1425 | } | |
1426 | ||
dd2a3b7a MH |
1427 | #define ECRYPTFS_DONT_VALIDATE_HEADER_SIZE 0 |
1428 | #define ECRYPTFS_VALIDATE_HEADER_SIZE 1 | |
237fead6 | 1429 | static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat, |
dd2a3b7a MH |
1430 | char *virt, int *bytes_read, |
1431 | int validate_header_size) | |
237fead6 MH |
1432 | { |
1433 | int rc = 0; | |
1434 | u32 header_extent_size; | |
1435 | u16 num_header_extents_at_front; | |
1436 | ||
29335c6a HH |
1437 | header_extent_size = get_unaligned_be32(virt); |
1438 | virt += sizeof(__be32); | |
1439 | num_header_extents_at_front = get_unaligned_be16(virt); | |
fa3ef1cb TH |
1440 | crypt_stat->metadata_size = (((size_t)num_header_extents_at_front |
1441 | * (size_t)header_extent_size)); | |
29335c6a | 1442 | (*bytes_read) = (sizeof(__be32) + sizeof(__be16)); |
dd2a3b7a | 1443 | if ((validate_header_size == ECRYPTFS_VALIDATE_HEADER_SIZE) |
fa3ef1cb | 1444 | && (crypt_stat->metadata_size |
dd2a3b7a | 1445 | < ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)) { |
237fead6 | 1446 | rc = -EINVAL; |
cc11beff | 1447 | printk(KERN_WARNING "Invalid header size: [%zd]\n", |
fa3ef1cb | 1448 | crypt_stat->metadata_size); |
237fead6 MH |
1449 | } |
1450 | return rc; | |
1451 | } | |
1452 | ||
1453 | /** | |
1454 | * set_default_header_data | |
22e78faf | 1455 | * @crypt_stat: The cryptographic context |
237fead6 MH |
1456 | * |
1457 | * For version 0 file format; this function is only for backwards | |
1458 | * compatibility for files created with the prior versions of | |
1459 | * eCryptfs. | |
1460 | */ | |
1461 | static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat) | |
1462 | { | |
fa3ef1cb | 1463 | crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; |
237fead6 MH |
1464 | } |
1465 | ||
3aeb86ea TH |
1466 | void ecryptfs_i_size_init(const char *page_virt, struct inode *inode) |
1467 | { | |
1468 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat; | |
1469 | struct ecryptfs_crypt_stat *crypt_stat; | |
1470 | u64 file_size; | |
1471 | ||
1472 | crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; | |
1473 | mount_crypt_stat = | |
1474 | &ecryptfs_superblock_to_private(inode->i_sb)->mount_crypt_stat; | |
1475 | if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) { | |
1476 | file_size = i_size_read(ecryptfs_inode_to_lower(inode)); | |
1477 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) | |
1478 | file_size += crypt_stat->metadata_size; | |
1479 | } else | |
1480 | file_size = get_unaligned_be64(page_virt); | |
1481 | i_size_write(inode, (loff_t)file_size); | |
1482 | crypt_stat->flags |= ECRYPTFS_I_SIZE_INITIALIZED; | |
1483 | } | |
1484 | ||
237fead6 MH |
1485 | /** |
1486 | * ecryptfs_read_headers_virt | |
22e78faf MH |
1487 | * @page_virt: The virtual address into which to read the headers |
1488 | * @crypt_stat: The cryptographic context | |
1489 | * @ecryptfs_dentry: The eCryptfs dentry | |
1490 | * @validate_header_size: Whether to validate the header size while reading | |
237fead6 MH |
1491 | * |
1492 | * Read/parse the header data. The header format is detailed in the | |
1493 | * comment block for the ecryptfs_write_headers_virt() function. | |
1494 | * | |
1495 | * Returns zero on success | |
1496 | */ | |
1497 | static int ecryptfs_read_headers_virt(char *page_virt, | |
1498 | struct ecryptfs_crypt_stat *crypt_stat, | |
dd2a3b7a MH |
1499 | struct dentry *ecryptfs_dentry, |
1500 | int validate_header_size) | |
237fead6 MH |
1501 | { |
1502 | int rc = 0; | |
1503 | int offset; | |
1504 | int bytes_read; | |
1505 | ||
1506 | ecryptfs_set_default_sizes(crypt_stat); | |
1507 | crypt_stat->mount_crypt_stat = &ecryptfs_superblock_to_private( | |
1508 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
1509 | offset = ECRYPTFS_FILE_SIZE_BYTES; | |
7a86617e TH |
1510 | rc = ecryptfs_validate_marker(page_virt + offset); |
1511 | if (rc) | |
237fead6 | 1512 | goto out; |
3aeb86ea TH |
1513 | if (!(crypt_stat->flags & ECRYPTFS_I_SIZE_INITIALIZED)) |
1514 | ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode); | |
237fead6 MH |
1515 | offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; |
1516 | rc = ecryptfs_process_flags(crypt_stat, (page_virt + offset), | |
1517 | &bytes_read); | |
1518 | if (rc) { | |
1519 | ecryptfs_printk(KERN_WARNING, "Error processing flags\n"); | |
1520 | goto out; | |
1521 | } | |
1522 | if (crypt_stat->file_version > ECRYPTFS_SUPPORTED_FILE_VERSION) { | |
1523 | ecryptfs_printk(KERN_WARNING, "File version is [%d]; only " | |
1524 | "file version [%d] is supported by this " | |
1525 | "version of eCryptfs\n", | |
1526 | crypt_stat->file_version, | |
1527 | ECRYPTFS_SUPPORTED_FILE_VERSION); | |
1528 | rc = -EINVAL; | |
1529 | goto out; | |
1530 | } | |
1531 | offset += bytes_read; | |
1532 | if (crypt_stat->file_version >= 1) { | |
1533 | rc = parse_header_metadata(crypt_stat, (page_virt + offset), | |
dd2a3b7a | 1534 | &bytes_read, validate_header_size); |
237fead6 MH |
1535 | if (rc) { |
1536 | ecryptfs_printk(KERN_WARNING, "Error reading header " | |
1537 | "metadata; rc = [%d]\n", rc); | |
1538 | } | |
1539 | offset += bytes_read; | |
1540 | } else | |
1541 | set_default_header_data(crypt_stat); | |
1542 | rc = ecryptfs_parse_packet_set(crypt_stat, (page_virt + offset), | |
1543 | ecryptfs_dentry); | |
1544 | out: | |
1545 | return rc; | |
1546 | } | |
1547 | ||
1548 | /** | |
dd2a3b7a | 1549 | * ecryptfs_read_xattr_region |
22e78faf | 1550 | * @page_virt: The vitual address into which to read the xattr data |
2ed92554 | 1551 | * @ecryptfs_inode: The eCryptfs inode |
dd2a3b7a MH |
1552 | * |
1553 | * Attempts to read the crypto metadata from the extended attribute | |
1554 | * region of the lower file. | |
22e78faf MH |
1555 | * |
1556 | * Returns zero on success; non-zero on error | |
dd2a3b7a | 1557 | */ |
d7cdc5fe | 1558 | int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode) |
dd2a3b7a | 1559 | { |
d7cdc5fe MH |
1560 | struct dentry *lower_dentry = |
1561 | ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry; | |
dd2a3b7a MH |
1562 | ssize_t size; |
1563 | int rc = 0; | |
1564 | ||
d7cdc5fe MH |
1565 | size = ecryptfs_getxattr_lower(lower_dentry, ECRYPTFS_XATTR_NAME, |
1566 | page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE); | |
dd2a3b7a | 1567 | if (size < 0) { |
25bd8174 MH |
1568 | if (unlikely(ecryptfs_verbosity > 0)) |
1569 | printk(KERN_INFO "Error attempting to read the [%s] " | |
1570 | "xattr from the lower file; return value = " | |
1571 | "[%zd]\n", ECRYPTFS_XATTR_NAME, size); | |
dd2a3b7a MH |
1572 | rc = -EINVAL; |
1573 | goto out; | |
1574 | } | |
1575 | out: | |
1576 | return rc; | |
1577 | } | |
1578 | ||
778aeb42 | 1579 | int ecryptfs_read_and_validate_xattr_region(struct dentry *dentry, |
3b06b3eb | 1580 | struct inode *inode) |
dd2a3b7a | 1581 | { |
778aeb42 TH |
1582 | u8 file_size[ECRYPTFS_SIZE_AND_MARKER_BYTES]; |
1583 | u8 *marker = file_size + ECRYPTFS_FILE_SIZE_BYTES; | |
dd2a3b7a MH |
1584 | int rc; |
1585 | ||
778aeb42 TH |
1586 | rc = ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), |
1587 | ECRYPTFS_XATTR_NAME, file_size, | |
1588 | ECRYPTFS_SIZE_AND_MARKER_BYTES); | |
1589 | if (rc < ECRYPTFS_SIZE_AND_MARKER_BYTES) | |
1590 | return rc >= 0 ? -EINVAL : rc; | |
1591 | rc = ecryptfs_validate_marker(marker); | |
1592 | if (!rc) | |
1593 | ecryptfs_i_size_init(file_size, inode); | |
dd2a3b7a MH |
1594 | return rc; |
1595 | } | |
1596 | ||
1597 | /** | |
1598 | * ecryptfs_read_metadata | |
1599 | * | |
1600 | * Common entry point for reading file metadata. From here, we could | |
1601 | * retrieve the header information from the header region of the file, | |
1602 | * the xattr region of the file, or some other repostory that is | |
1603 | * stored separately from the file itself. The current implementation | |
1604 | * supports retrieving the metadata information from the file contents | |
1605 | * and from the xattr region. | |
237fead6 MH |
1606 | * |
1607 | * Returns zero if valid headers found and parsed; non-zero otherwise | |
1608 | */ | |
d7cdc5fe | 1609 | int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry) |
237fead6 | 1610 | { |
bb450361 TG |
1611 | int rc; |
1612 | char *page_virt; | |
d7cdc5fe | 1613 | struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode; |
237fead6 | 1614 | struct ecryptfs_crypt_stat *crypt_stat = |
d7cdc5fe | 1615 | &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
e77a56dd MH |
1616 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
1617 | &ecryptfs_superblock_to_private( | |
1618 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
237fead6 | 1619 | |
e77a56dd MH |
1620 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
1621 | mount_crypt_stat); | |
237fead6 | 1622 | /* Read the first page from the underlying file */ |
30632870 | 1623 | page_virt = kmem_cache_alloc(ecryptfs_header_cache, GFP_USER); |
237fead6 MH |
1624 | if (!page_virt) { |
1625 | rc = -ENOMEM; | |
d7cdc5fe | 1626 | printk(KERN_ERR "%s: Unable to allocate page_virt\n", |
18d1dbf1 | 1627 | __func__); |
237fead6 MH |
1628 | goto out; |
1629 | } | |
d7cdc5fe MH |
1630 | rc = ecryptfs_read_lower(page_virt, 0, crypt_stat->extent_size, |
1631 | ecryptfs_inode); | |
96a7b9c2 | 1632 | if (rc >= 0) |
d7cdc5fe MH |
1633 | rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, |
1634 | ecryptfs_dentry, | |
1635 | ECRYPTFS_VALIDATE_HEADER_SIZE); | |
237fead6 | 1636 | if (rc) { |
bb450361 | 1637 | /* metadata is not in the file header, so try xattrs */ |
1984c23f | 1638 | memset(page_virt, 0, PAGE_CACHE_SIZE); |
d7cdc5fe | 1639 | rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode); |
dd2a3b7a MH |
1640 | if (rc) { |
1641 | printk(KERN_DEBUG "Valid eCryptfs headers not found in " | |
30373dc0 TG |
1642 | "file header region or xattr region, inode %lu\n", |
1643 | ecryptfs_inode->i_ino); | |
dd2a3b7a MH |
1644 | rc = -EINVAL; |
1645 | goto out; | |
1646 | } | |
1647 | rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, | |
1648 | ecryptfs_dentry, | |
1649 | ECRYPTFS_DONT_VALIDATE_HEADER_SIZE); | |
1650 | if (rc) { | |
1651 | printk(KERN_DEBUG "Valid eCryptfs headers not found in " | |
30373dc0 TG |
1652 | "file xattr region either, inode %lu\n", |
1653 | ecryptfs_inode->i_ino); | |
dd2a3b7a MH |
1654 | rc = -EINVAL; |
1655 | } | |
1656 | if (crypt_stat->mount_crypt_stat->flags | |
1657 | & ECRYPTFS_XATTR_METADATA_ENABLED) { | |
1658 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; | |
1659 | } else { | |
1660 | printk(KERN_WARNING "Attempt to access file with " | |
1661 | "crypto metadata only in the extended attribute " | |
1662 | "region, but eCryptfs was mounted without " | |
1663 | "xattr support enabled. eCryptfs will not treat " | |
30373dc0 TG |
1664 | "this like an encrypted file, inode %lu\n", |
1665 | ecryptfs_inode->i_ino); | |
dd2a3b7a MH |
1666 | rc = -EINVAL; |
1667 | } | |
237fead6 MH |
1668 | } |
1669 | out: | |
1670 | if (page_virt) { | |
1671 | memset(page_virt, 0, PAGE_CACHE_SIZE); | |
30632870 | 1672 | kmem_cache_free(ecryptfs_header_cache, page_virt); |
237fead6 MH |
1673 | } |
1674 | return rc; | |
1675 | } | |
1676 | ||
51ca58dc MH |
1677 | /** |
1678 | * ecryptfs_encrypt_filename - encrypt filename | |
1679 | * | |
1680 | * CBC-encrypts the filename. We do not want to encrypt the same | |
1681 | * filename with the same key and IV, which may happen with hard | |
1682 | * links, so we prepend random bits to each filename. | |
1683 | * | |
1684 | * Returns zero on success; non-zero otherwise | |
1685 | */ | |
1686 | static int | |
1687 | ecryptfs_encrypt_filename(struct ecryptfs_filename *filename, | |
1688 | struct ecryptfs_crypt_stat *crypt_stat, | |
1689 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
1690 | { | |
1691 | int rc = 0; | |
1692 | ||
1693 | filename->encrypted_filename = NULL; | |
1694 | filename->encrypted_filename_size = 0; | |
1695 | if ((crypt_stat && (crypt_stat->flags & ECRYPTFS_ENCFN_USE_MOUNT_FNEK)) | |
1696 | || (mount_crypt_stat && (mount_crypt_stat->flags | |
1697 | & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK))) { | |
1698 | size_t packet_size; | |
1699 | size_t remaining_bytes; | |
1700 | ||
1701 | rc = ecryptfs_write_tag_70_packet( | |
1702 | NULL, NULL, | |
1703 | &filename->encrypted_filename_size, | |
1704 | mount_crypt_stat, NULL, | |
1705 | filename->filename_size); | |
1706 | if (rc) { | |
1707 | printk(KERN_ERR "%s: Error attempting to get packet " | |
1708 | "size for tag 72; rc = [%d]\n", __func__, | |
1709 | rc); | |
1710 | filename->encrypted_filename_size = 0; | |
1711 | goto out; | |
1712 | } | |
1713 | filename->encrypted_filename = | |
1714 | kmalloc(filename->encrypted_filename_size, GFP_KERNEL); | |
1715 | if (!filename->encrypted_filename) { | |
1716 | printk(KERN_ERR "%s: Out of memory whilst attempting " | |
df261c52 | 1717 | "to kmalloc [%zd] bytes\n", __func__, |
51ca58dc MH |
1718 | filename->encrypted_filename_size); |
1719 | rc = -ENOMEM; | |
1720 | goto out; | |
1721 | } | |
1722 | remaining_bytes = filename->encrypted_filename_size; | |
1723 | rc = ecryptfs_write_tag_70_packet(filename->encrypted_filename, | |
1724 | &remaining_bytes, | |
1725 | &packet_size, | |
1726 | mount_crypt_stat, | |
1727 | filename->filename, | |
1728 | filename->filename_size); | |
1729 | if (rc) { | |
1730 | printk(KERN_ERR "%s: Error attempting to generate " | |
1731 | "tag 70 packet; rc = [%d]\n", __func__, | |
1732 | rc); | |
1733 | kfree(filename->encrypted_filename); | |
1734 | filename->encrypted_filename = NULL; | |
1735 | filename->encrypted_filename_size = 0; | |
1736 | goto out; | |
1737 | } | |
1738 | filename->encrypted_filename_size = packet_size; | |
1739 | } else { | |
1740 | printk(KERN_ERR "%s: No support for requested filename " | |
1741 | "encryption method in this release\n", __func__); | |
df6ad33b | 1742 | rc = -EOPNOTSUPP; |
51ca58dc MH |
1743 | goto out; |
1744 | } | |
1745 | out: | |
1746 | return rc; | |
1747 | } | |
1748 | ||
1749 | static int ecryptfs_copy_filename(char **copied_name, size_t *copied_name_size, | |
1750 | const char *name, size_t name_size) | |
1751 | { | |
1752 | int rc = 0; | |
1753 | ||
fd9fc842 | 1754 | (*copied_name) = kmalloc((name_size + 1), GFP_KERNEL); |
51ca58dc MH |
1755 | if (!(*copied_name)) { |
1756 | rc = -ENOMEM; | |
1757 | goto out; | |
1758 | } | |
1759 | memcpy((void *)(*copied_name), (void *)name, name_size); | |
1760 | (*copied_name)[(name_size)] = '\0'; /* Only for convenience | |
1761 | * in printing out the | |
1762 | * string in debug | |
1763 | * messages */ | |
fd9fc842 | 1764 | (*copied_name_size) = name_size; |
51ca58dc MH |
1765 | out: |
1766 | return rc; | |
1767 | } | |
1768 | ||
237fead6 | 1769 | /** |
f4aad16a | 1770 | * ecryptfs_process_key_cipher - Perform key cipher initialization. |
237fead6 | 1771 | * @key_tfm: Crypto context for key material, set by this function |
e5d9cbde MH |
1772 | * @cipher_name: Name of the cipher |
1773 | * @key_size: Size of the key in bytes | |
237fead6 MH |
1774 | * |
1775 | * Returns zero on success. Any crypto_tfm structs allocated here | |
1776 | * should be released by other functions, such as on a superblock put | |
1777 | * event, regardless of whether this function succeeds for fails. | |
1778 | */ | |
cd9d67df | 1779 | static int |
f4aad16a MH |
1780 | ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm, |
1781 | char *cipher_name, size_t *key_size) | |
237fead6 MH |
1782 | { |
1783 | char dummy_key[ECRYPTFS_MAX_KEY_BYTES]; | |
ece550f5 | 1784 | char *full_alg_name = NULL; |
237fead6 MH |
1785 | int rc; |
1786 | ||
e5d9cbde MH |
1787 | *key_tfm = NULL; |
1788 | if (*key_size > ECRYPTFS_MAX_KEY_BYTES) { | |
237fead6 | 1789 | rc = -EINVAL; |
df261c52 | 1790 | printk(KERN_ERR "Requested key size is [%zd] bytes; maximum " |
e5d9cbde | 1791 | "allowable is [%d]\n", *key_size, ECRYPTFS_MAX_KEY_BYTES); |
237fead6 MH |
1792 | goto out; |
1793 | } | |
8bba066f MH |
1794 | rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, cipher_name, |
1795 | "ecb"); | |
1796 | if (rc) | |
1797 | goto out; | |
1798 | *key_tfm = crypto_alloc_blkcipher(full_alg_name, 0, CRYPTO_ALG_ASYNC); | |
8bba066f MH |
1799 | if (IS_ERR(*key_tfm)) { |
1800 | rc = PTR_ERR(*key_tfm); | |
237fead6 | 1801 | printk(KERN_ERR "Unable to allocate crypto cipher with name " |
38268498 | 1802 | "[%s]; rc = [%d]\n", full_alg_name, rc); |
237fead6 MH |
1803 | goto out; |
1804 | } | |
8bba066f MH |
1805 | crypto_blkcipher_set_flags(*key_tfm, CRYPTO_TFM_REQ_WEAK_KEY); |
1806 | if (*key_size == 0) { | |
1807 | struct blkcipher_alg *alg = crypto_blkcipher_alg(*key_tfm); | |
1808 | ||
1809 | *key_size = alg->max_keysize; | |
1810 | } | |
e5d9cbde | 1811 | get_random_bytes(dummy_key, *key_size); |
8bba066f | 1812 | rc = crypto_blkcipher_setkey(*key_tfm, dummy_key, *key_size); |
237fead6 | 1813 | if (rc) { |
df261c52 | 1814 | printk(KERN_ERR "Error attempting to set key of size [%zd] for " |
38268498 DH |
1815 | "cipher [%s]; rc = [%d]\n", *key_size, full_alg_name, |
1816 | rc); | |
237fead6 MH |
1817 | rc = -EINVAL; |
1818 | goto out; | |
1819 | } | |
1820 | out: | |
ece550f5 | 1821 | kfree(full_alg_name); |
237fead6 MH |
1822 | return rc; |
1823 | } | |
f4aad16a MH |
1824 | |
1825 | struct kmem_cache *ecryptfs_key_tfm_cache; | |
7896b631 | 1826 | static struct list_head key_tfm_list; |
af440f52 | 1827 | struct mutex key_tfm_list_mutex; |
f4aad16a | 1828 | |
7371a382 | 1829 | int __init ecryptfs_init_crypto(void) |
f4aad16a MH |
1830 | { |
1831 | mutex_init(&key_tfm_list_mutex); | |
1832 | INIT_LIST_HEAD(&key_tfm_list); | |
1833 | return 0; | |
1834 | } | |
1835 | ||
af440f52 ES |
1836 | /** |
1837 | * ecryptfs_destroy_crypto - free all cached key_tfms on key_tfm_list | |
1838 | * | |
1839 | * Called only at module unload time | |
1840 | */ | |
fcd12835 | 1841 | int ecryptfs_destroy_crypto(void) |
f4aad16a MH |
1842 | { |
1843 | struct ecryptfs_key_tfm *key_tfm, *key_tfm_tmp; | |
1844 | ||
1845 | mutex_lock(&key_tfm_list_mutex); | |
1846 | list_for_each_entry_safe(key_tfm, key_tfm_tmp, &key_tfm_list, | |
1847 | key_tfm_list) { | |
1848 | list_del(&key_tfm->key_tfm_list); | |
1849 | if (key_tfm->key_tfm) | |
1850 | crypto_free_blkcipher(key_tfm->key_tfm); | |
1851 | kmem_cache_free(ecryptfs_key_tfm_cache, key_tfm); | |
1852 | } | |
1853 | mutex_unlock(&key_tfm_list_mutex); | |
1854 | return 0; | |
1855 | } | |
1856 | ||
1857 | int | |
1858 | ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name, | |
1859 | size_t key_size) | |
1860 | { | |
1861 | struct ecryptfs_key_tfm *tmp_tfm; | |
1862 | int rc = 0; | |
1863 | ||
af440f52 ES |
1864 | BUG_ON(!mutex_is_locked(&key_tfm_list_mutex)); |
1865 | ||
f4aad16a MH |
1866 | tmp_tfm = kmem_cache_alloc(ecryptfs_key_tfm_cache, GFP_KERNEL); |
1867 | if (key_tfm != NULL) | |
1868 | (*key_tfm) = tmp_tfm; | |
1869 | if (!tmp_tfm) { | |
1870 | rc = -ENOMEM; | |
1871 | printk(KERN_ERR "Error attempting to allocate from " | |
1872 | "ecryptfs_key_tfm_cache\n"); | |
1873 | goto out; | |
1874 | } | |
1875 | mutex_init(&tmp_tfm->key_tfm_mutex); | |
1876 | strncpy(tmp_tfm->cipher_name, cipher_name, | |
1877 | ECRYPTFS_MAX_CIPHER_NAME_SIZE); | |
b8862906 | 1878 | tmp_tfm->cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; |
f4aad16a | 1879 | tmp_tfm->key_size = key_size; |
5dda6992 MH |
1880 | rc = ecryptfs_process_key_cipher(&tmp_tfm->key_tfm, |
1881 | tmp_tfm->cipher_name, | |
1882 | &tmp_tfm->key_size); | |
1883 | if (rc) { | |
f4aad16a MH |
1884 | printk(KERN_ERR "Error attempting to initialize key TFM " |
1885 | "cipher with name = [%s]; rc = [%d]\n", | |
1886 | tmp_tfm->cipher_name, rc); | |
1887 | kmem_cache_free(ecryptfs_key_tfm_cache, tmp_tfm); | |
1888 | if (key_tfm != NULL) | |
1889 | (*key_tfm) = NULL; | |
1890 | goto out; | |
1891 | } | |
f4aad16a | 1892 | list_add(&tmp_tfm->key_tfm_list, &key_tfm_list); |
f4aad16a MH |
1893 | out: |
1894 | return rc; | |
1895 | } | |
1896 | ||
af440f52 ES |
1897 | /** |
1898 | * ecryptfs_tfm_exists - Search for existing tfm for cipher_name. | |
1899 | * @cipher_name: the name of the cipher to search for | |
1900 | * @key_tfm: set to corresponding tfm if found | |
1901 | * | |
1902 | * Searches for cached key_tfm matching @cipher_name | |
1903 | * Must be called with &key_tfm_list_mutex held | |
1904 | * Returns 1 if found, with @key_tfm set | |
1905 | * Returns 0 if not found, with @key_tfm set to NULL | |
1906 | */ | |
1907 | int ecryptfs_tfm_exists(char *cipher_name, struct ecryptfs_key_tfm **key_tfm) | |
1908 | { | |
1909 | struct ecryptfs_key_tfm *tmp_key_tfm; | |
1910 | ||
1911 | BUG_ON(!mutex_is_locked(&key_tfm_list_mutex)); | |
1912 | ||
1913 | list_for_each_entry(tmp_key_tfm, &key_tfm_list, key_tfm_list) { | |
1914 | if (strcmp(tmp_key_tfm->cipher_name, cipher_name) == 0) { | |
1915 | if (key_tfm) | |
1916 | (*key_tfm) = tmp_key_tfm; | |
1917 | return 1; | |
1918 | } | |
1919 | } | |
1920 | if (key_tfm) | |
1921 | (*key_tfm) = NULL; | |
1922 | return 0; | |
1923 | } | |
1924 | ||
1925 | /** | |
1926 | * ecryptfs_get_tfm_and_mutex_for_cipher_name | |
1927 | * | |
1928 | * @tfm: set to cached tfm found, or new tfm created | |
1929 | * @tfm_mutex: set to mutex for cached tfm found, or new tfm created | |
1930 | * @cipher_name: the name of the cipher to search for and/or add | |
1931 | * | |
1932 | * Sets pointers to @tfm & @tfm_mutex matching @cipher_name. | |
1933 | * Searches for cached item first, and creates new if not found. | |
1934 | * Returns 0 on success, non-zero if adding new cipher failed | |
1935 | */ | |
f4aad16a MH |
1936 | int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm, |
1937 | struct mutex **tfm_mutex, | |
1938 | char *cipher_name) | |
1939 | { | |
1940 | struct ecryptfs_key_tfm *key_tfm; | |
1941 | int rc = 0; | |
1942 | ||
1943 | (*tfm) = NULL; | |
1944 | (*tfm_mutex) = NULL; | |
af440f52 | 1945 | |
f4aad16a | 1946 | mutex_lock(&key_tfm_list_mutex); |
af440f52 ES |
1947 | if (!ecryptfs_tfm_exists(cipher_name, &key_tfm)) { |
1948 | rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0); | |
1949 | if (rc) { | |
1950 | printk(KERN_ERR "Error adding new key_tfm to list; " | |
1951 | "rc = [%d]\n", rc); | |
f4aad16a MH |
1952 | goto out; |
1953 | } | |
1954 | } | |
f4aad16a MH |
1955 | (*tfm) = key_tfm->key_tfm; |
1956 | (*tfm_mutex) = &key_tfm->key_tfm_mutex; | |
1957 | out: | |
71fd5179 | 1958 | mutex_unlock(&key_tfm_list_mutex); |
f4aad16a MH |
1959 | return rc; |
1960 | } | |
51ca58dc MH |
1961 | |
1962 | /* 64 characters forming a 6-bit target field */ | |
1963 | static unsigned char *portable_filename_chars = ("-.0123456789ABCD" | |
1964 | "EFGHIJKLMNOPQRST" | |
1965 | "UVWXYZabcdefghij" | |
1966 | "klmnopqrstuvwxyz"); | |
1967 | ||
1968 | /* We could either offset on every reverse map or just pad some 0x00's | |
1969 | * at the front here */ | |
0f751e64 | 1970 | static const unsigned char filename_rev_map[256] = { |
51ca58dc MH |
1971 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 7 */ |
1972 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 15 */ | |
1973 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 23 */ | |
1974 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 31 */ | |
1975 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 39 */ | |
1976 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, /* 47 */ | |
1977 | 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, /* 55 */ | |
1978 | 0x0A, 0x0B, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 63 */ | |
1979 | 0x00, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, /* 71 */ | |
1980 | 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, /* 79 */ | |
1981 | 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, /* 87 */ | |
1982 | 0x23, 0x24, 0x25, 0x00, 0x00, 0x00, 0x00, 0x00, /* 95 */ | |
1983 | 0x00, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, /* 103 */ | |
1984 | 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, /* 111 */ | |
1985 | 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, /* 119 */ | |
0f751e64 | 1986 | 0x3D, 0x3E, 0x3F /* 123 - 255 initialized to 0x00 */ |
51ca58dc MH |
1987 | }; |
1988 | ||
1989 | /** | |
1990 | * ecryptfs_encode_for_filename | |
1991 | * @dst: Destination location for encoded filename | |
1992 | * @dst_size: Size of the encoded filename in bytes | |
1993 | * @src: Source location for the filename to encode | |
1994 | * @src_size: Size of the source in bytes | |
1995 | */ | |
37028758 | 1996 | static void ecryptfs_encode_for_filename(unsigned char *dst, size_t *dst_size, |
51ca58dc MH |
1997 | unsigned char *src, size_t src_size) |
1998 | { | |
1999 | size_t num_blocks; | |
2000 | size_t block_num = 0; | |
2001 | size_t dst_offset = 0; | |
2002 | unsigned char last_block[3]; | |
2003 | ||
2004 | if (src_size == 0) { | |
2005 | (*dst_size) = 0; | |
2006 | goto out; | |
2007 | } | |
2008 | num_blocks = (src_size / 3); | |
2009 | if ((src_size % 3) == 0) { | |
2010 | memcpy(last_block, (&src[src_size - 3]), 3); | |
2011 | } else { | |
2012 | num_blocks++; | |
2013 | last_block[2] = 0x00; | |
2014 | switch (src_size % 3) { | |
2015 | case 1: | |
2016 | last_block[0] = src[src_size - 1]; | |
2017 | last_block[1] = 0x00; | |
2018 | break; | |
2019 | case 2: | |
2020 | last_block[0] = src[src_size - 2]; | |
2021 | last_block[1] = src[src_size - 1]; | |
2022 | } | |
2023 | } | |
2024 | (*dst_size) = (num_blocks * 4); | |
2025 | if (!dst) | |
2026 | goto out; | |
2027 | while (block_num < num_blocks) { | |
2028 | unsigned char *src_block; | |
2029 | unsigned char dst_block[4]; | |
2030 | ||
2031 | if (block_num == (num_blocks - 1)) | |
2032 | src_block = last_block; | |
2033 | else | |
2034 | src_block = &src[block_num * 3]; | |
2035 | dst_block[0] = ((src_block[0] >> 2) & 0x3F); | |
2036 | dst_block[1] = (((src_block[0] << 4) & 0x30) | |
2037 | | ((src_block[1] >> 4) & 0x0F)); | |
2038 | dst_block[2] = (((src_block[1] << 2) & 0x3C) | |
2039 | | ((src_block[2] >> 6) & 0x03)); | |
2040 | dst_block[3] = (src_block[2] & 0x3F); | |
2041 | dst[dst_offset++] = portable_filename_chars[dst_block[0]]; | |
2042 | dst[dst_offset++] = portable_filename_chars[dst_block[1]]; | |
2043 | dst[dst_offset++] = portable_filename_chars[dst_block[2]]; | |
2044 | dst[dst_offset++] = portable_filename_chars[dst_block[3]]; | |
2045 | block_num++; | |
2046 | } | |
2047 | out: | |
2048 | return; | |
2049 | } | |
2050 | ||
4a26620d TH |
2051 | static size_t ecryptfs_max_decoded_size(size_t encoded_size) |
2052 | { | |
2053 | /* Not exact; conservatively long. Every block of 4 | |
2054 | * encoded characters decodes into a block of 3 | |
2055 | * decoded characters. This segment of code provides | |
2056 | * the caller with the maximum amount of allocated | |
2057 | * space that @dst will need to point to in a | |
2058 | * subsequent call. */ | |
2059 | return ((encoded_size + 1) * 3) / 4; | |
2060 | } | |
2061 | ||
71c11c37 MH |
2062 | /** |
2063 | * ecryptfs_decode_from_filename | |
2064 | * @dst: If NULL, this function only sets @dst_size and returns. If | |
2065 | * non-NULL, this function decodes the encoded octets in @src | |
2066 | * into the memory that @dst points to. | |
2067 | * @dst_size: Set to the size of the decoded string. | |
2068 | * @src: The encoded set of octets to decode. | |
2069 | * @src_size: The size of the encoded set of octets to decode. | |
2070 | */ | |
2071 | static void | |
2072 | ecryptfs_decode_from_filename(unsigned char *dst, size_t *dst_size, | |
2073 | const unsigned char *src, size_t src_size) | |
51ca58dc MH |
2074 | { |
2075 | u8 current_bit_offset = 0; | |
2076 | size_t src_byte_offset = 0; | |
2077 | size_t dst_byte_offset = 0; | |
51ca58dc MH |
2078 | |
2079 | if (dst == NULL) { | |
4a26620d | 2080 | (*dst_size) = ecryptfs_max_decoded_size(src_size); |
51ca58dc MH |
2081 | goto out; |
2082 | } | |
2083 | while (src_byte_offset < src_size) { | |
2084 | unsigned char src_byte = | |
2085 | filename_rev_map[(int)src[src_byte_offset]]; | |
2086 | ||
2087 | switch (current_bit_offset) { | |
2088 | case 0: | |
2089 | dst[dst_byte_offset] = (src_byte << 2); | |
2090 | current_bit_offset = 6; | |
2091 | break; | |
2092 | case 6: | |
2093 | dst[dst_byte_offset++] |= (src_byte >> 4); | |
2094 | dst[dst_byte_offset] = ((src_byte & 0xF) | |
2095 | << 4); | |
2096 | current_bit_offset = 4; | |
2097 | break; | |
2098 | case 4: | |
2099 | dst[dst_byte_offset++] |= (src_byte >> 2); | |
2100 | dst[dst_byte_offset] = (src_byte << 6); | |
2101 | current_bit_offset = 2; | |
2102 | break; | |
2103 | case 2: | |
2104 | dst[dst_byte_offset++] |= (src_byte); | |
2105 | dst[dst_byte_offset] = 0; | |
2106 | current_bit_offset = 0; | |
2107 | break; | |
2108 | } | |
2109 | src_byte_offset++; | |
2110 | } | |
2111 | (*dst_size) = dst_byte_offset; | |
2112 | out: | |
71c11c37 | 2113 | return; |
51ca58dc MH |
2114 | } |
2115 | ||
2116 | /** | |
2117 | * ecryptfs_encrypt_and_encode_filename - converts a plaintext file name to cipher text | |
2118 | * @crypt_stat: The crypt_stat struct associated with the file anem to encode | |
2119 | * @name: The plaintext name | |
2120 | * @length: The length of the plaintext | |
2121 | * @encoded_name: The encypted name | |
2122 | * | |
2123 | * Encrypts and encodes a filename into something that constitutes a | |
2124 | * valid filename for a filesystem, with printable characters. | |
2125 | * | |
2126 | * We assume that we have a properly initialized crypto context, | |
2127 | * pointed to by crypt_stat->tfm. | |
2128 | * | |
2129 | * Returns zero on success; non-zero on otherwise | |
2130 | */ | |
2131 | int ecryptfs_encrypt_and_encode_filename( | |
2132 | char **encoded_name, | |
2133 | size_t *encoded_name_size, | |
2134 | struct ecryptfs_crypt_stat *crypt_stat, | |
2135 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
2136 | const char *name, size_t name_size) | |
2137 | { | |
2138 | size_t encoded_name_no_prefix_size; | |
2139 | int rc = 0; | |
2140 | ||
2141 | (*encoded_name) = NULL; | |
2142 | (*encoded_name_size) = 0; | |
2143 | if ((crypt_stat && (crypt_stat->flags & ECRYPTFS_ENCRYPT_FILENAMES)) | |
2144 | || (mount_crypt_stat && (mount_crypt_stat->flags | |
2145 | & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES))) { | |
2146 | struct ecryptfs_filename *filename; | |
2147 | ||
2148 | filename = kzalloc(sizeof(*filename), GFP_KERNEL); | |
2149 | if (!filename) { | |
2150 | printk(KERN_ERR "%s: Out of memory whilst attempting " | |
a8f12864 | 2151 | "to kzalloc [%zd] bytes\n", __func__, |
51ca58dc MH |
2152 | sizeof(*filename)); |
2153 | rc = -ENOMEM; | |
2154 | goto out; | |
2155 | } | |
2156 | filename->filename = (char *)name; | |
2157 | filename->filename_size = name_size; | |
2158 | rc = ecryptfs_encrypt_filename(filename, crypt_stat, | |
2159 | mount_crypt_stat); | |
2160 | if (rc) { | |
2161 | printk(KERN_ERR "%s: Error attempting to encrypt " | |
2162 | "filename; rc = [%d]\n", __func__, rc); | |
2163 | kfree(filename); | |
2164 | goto out; | |
2165 | } | |
2166 | ecryptfs_encode_for_filename( | |
2167 | NULL, &encoded_name_no_prefix_size, | |
2168 | filename->encrypted_filename, | |
2169 | filename->encrypted_filename_size); | |
2170 | if ((crypt_stat && (crypt_stat->flags | |
2171 | & ECRYPTFS_ENCFN_USE_MOUNT_FNEK)) | |
2172 | || (mount_crypt_stat | |
2173 | && (mount_crypt_stat->flags | |
2174 | & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK))) | |
2175 | (*encoded_name_size) = | |
2176 | (ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE | |
2177 | + encoded_name_no_prefix_size); | |
2178 | else | |
2179 | (*encoded_name_size) = | |
2180 | (ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX_SIZE | |
2181 | + encoded_name_no_prefix_size); | |
2182 | (*encoded_name) = kmalloc((*encoded_name_size) + 1, GFP_KERNEL); | |
2183 | if (!(*encoded_name)) { | |
2184 | printk(KERN_ERR "%s: Out of memory whilst attempting " | |
a8f12864 | 2185 | "to kzalloc [%zd] bytes\n", __func__, |
51ca58dc MH |
2186 | (*encoded_name_size)); |
2187 | rc = -ENOMEM; | |
2188 | kfree(filename->encrypted_filename); | |
2189 | kfree(filename); | |
2190 | goto out; | |
2191 | } | |
2192 | if ((crypt_stat && (crypt_stat->flags | |
2193 | & ECRYPTFS_ENCFN_USE_MOUNT_FNEK)) | |
2194 | || (mount_crypt_stat | |
2195 | && (mount_crypt_stat->flags | |
2196 | & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK))) { | |
2197 | memcpy((*encoded_name), | |
2198 | ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX, | |
2199 | ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE); | |
2200 | ecryptfs_encode_for_filename( | |
2201 | ((*encoded_name) | |
2202 | + ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE), | |
2203 | &encoded_name_no_prefix_size, | |
2204 | filename->encrypted_filename, | |
2205 | filename->encrypted_filename_size); | |
2206 | (*encoded_name_size) = | |
2207 | (ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE | |
2208 | + encoded_name_no_prefix_size); | |
2209 | (*encoded_name)[(*encoded_name_size)] = '\0'; | |
51ca58dc | 2210 | } else { |
df6ad33b | 2211 | rc = -EOPNOTSUPP; |
51ca58dc MH |
2212 | } |
2213 | if (rc) { | |
2214 | printk(KERN_ERR "%s: Error attempting to encode " | |
2215 | "encrypted filename; rc = [%d]\n", __func__, | |
2216 | rc); | |
2217 | kfree((*encoded_name)); | |
2218 | (*encoded_name) = NULL; | |
2219 | (*encoded_name_size) = 0; | |
2220 | } | |
2221 | kfree(filename->encrypted_filename); | |
2222 | kfree(filename); | |
2223 | } else { | |
2224 | rc = ecryptfs_copy_filename(encoded_name, | |
2225 | encoded_name_size, | |
2226 | name, name_size); | |
2227 | } | |
2228 | out: | |
2229 | return rc; | |
2230 | } | |
2231 | ||
2232 | /** | |
2233 | * ecryptfs_decode_and_decrypt_filename - converts the encoded cipher text name to decoded plaintext | |
2234 | * @plaintext_name: The plaintext name | |
2235 | * @plaintext_name_size: The plaintext name size | |
2236 | * @ecryptfs_dir_dentry: eCryptfs directory dentry | |
2237 | * @name: The filename in cipher text | |
2238 | * @name_size: The cipher text name size | |
2239 | * | |
2240 | * Decrypts and decodes the filename. | |
2241 | * | |
2242 | * Returns zero on error; non-zero otherwise | |
2243 | */ | |
2244 | int ecryptfs_decode_and_decrypt_filename(char **plaintext_name, | |
2245 | size_t *plaintext_name_size, | |
2246 | struct dentry *ecryptfs_dir_dentry, | |
2247 | const char *name, size_t name_size) | |
2248 | { | |
2aac0cf8 TH |
2249 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
2250 | &ecryptfs_superblock_to_private( | |
2251 | ecryptfs_dir_dentry->d_sb)->mount_crypt_stat; | |
51ca58dc MH |
2252 | char *decoded_name; |
2253 | size_t decoded_name_size; | |
2254 | size_t packet_size; | |
2255 | int rc = 0; | |
2256 | ||
2aac0cf8 TH |
2257 | if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) |
2258 | && !(mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) | |
2259 | && (name_size > ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE) | |
51ca58dc MH |
2260 | && (strncmp(name, ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX, |
2261 | ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE) == 0)) { | |
51ca58dc MH |
2262 | const char *orig_name = name; |
2263 | size_t orig_name_size = name_size; | |
2264 | ||
2265 | name += ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE; | |
2266 | name_size -= ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE; | |
71c11c37 MH |
2267 | ecryptfs_decode_from_filename(NULL, &decoded_name_size, |
2268 | name, name_size); | |
51ca58dc MH |
2269 | decoded_name = kmalloc(decoded_name_size, GFP_KERNEL); |
2270 | if (!decoded_name) { | |
2271 | printk(KERN_ERR "%s: Out of memory whilst attempting " | |
df261c52 | 2272 | "to kmalloc [%zd] bytes\n", __func__, |
51ca58dc MH |
2273 | decoded_name_size); |
2274 | rc = -ENOMEM; | |
2275 | goto out; | |
2276 | } | |
71c11c37 MH |
2277 | ecryptfs_decode_from_filename(decoded_name, &decoded_name_size, |
2278 | name, name_size); | |
51ca58dc MH |
2279 | rc = ecryptfs_parse_tag_70_packet(plaintext_name, |
2280 | plaintext_name_size, | |
2281 | &packet_size, | |
2282 | mount_crypt_stat, | |
2283 | decoded_name, | |
2284 | decoded_name_size); | |
2285 | if (rc) { | |
2286 | printk(KERN_INFO "%s: Could not parse tag 70 packet " | |
2287 | "from filename; copying through filename " | |
2288 | "as-is\n", __func__); | |
2289 | rc = ecryptfs_copy_filename(plaintext_name, | |
2290 | plaintext_name_size, | |
2291 | orig_name, orig_name_size); | |
2292 | goto out_free; | |
2293 | } | |
2294 | } else { | |
2295 | rc = ecryptfs_copy_filename(plaintext_name, | |
2296 | plaintext_name_size, | |
2297 | name, name_size); | |
2298 | goto out; | |
2299 | } | |
2300 | out_free: | |
2301 | kfree(decoded_name); | |
2302 | out: | |
2303 | return rc; | |
2304 | } | |
4a26620d TH |
2305 | |
2306 | #define ENC_NAME_MAX_BLOCKLEN_8_OR_16 143 | |
2307 | ||
2308 | int ecryptfs_set_f_namelen(long *namelen, long lower_namelen, | |
2309 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
2310 | { | |
2311 | struct blkcipher_desc desc; | |
2312 | struct mutex *tfm_mutex; | |
2313 | size_t cipher_blocksize; | |
2314 | int rc; | |
2315 | ||
2316 | if (!(mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)) { | |
2317 | (*namelen) = lower_namelen; | |
2318 | return 0; | |
2319 | } | |
2320 | ||
2321 | rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex, | |
2322 | mount_crypt_stat->global_default_fn_cipher_name); | |
2323 | if (unlikely(rc)) { | |
2324 | (*namelen) = 0; | |
2325 | return rc; | |
2326 | } | |
2327 | ||
2328 | mutex_lock(tfm_mutex); | |
2329 | cipher_blocksize = crypto_blkcipher_blocksize(desc.tfm); | |
2330 | mutex_unlock(tfm_mutex); | |
2331 | ||
2332 | /* Return an exact amount for the common cases */ | |
2333 | if (lower_namelen == NAME_MAX | |
2334 | && (cipher_blocksize == 8 || cipher_blocksize == 16)) { | |
2335 | (*namelen) = ENC_NAME_MAX_BLOCKLEN_8_OR_16; | |
2336 | return 0; | |
2337 | } | |
2338 | ||
2339 | /* Return a safe estimate for the uncommon cases */ | |
2340 | (*namelen) = lower_namelen; | |
2341 | (*namelen) -= ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE; | |
2342 | /* Since this is the max decoded size, subtract 1 "decoded block" len */ | |
2343 | (*namelen) = ecryptfs_max_decoded_size(*namelen) - 3; | |
2344 | (*namelen) -= ECRYPTFS_TAG_70_MAX_METADATA_SIZE; | |
2345 | (*namelen) -= ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES; | |
2346 | /* Worst case is that the filename is padded nearly a full block size */ | |
2347 | (*namelen) -= cipher_blocksize - 1; | |
2348 | ||
2349 | if ((*namelen) < 0) | |
2350 | (*namelen) = 0; | |
2351 | ||
2352 | return 0; | |
2353 | } |