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> | |
36 | #include "ecryptfs_kernel.h" | |
37 | ||
38 | static int | |
39 | ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
40 | struct page *dst_page, int dst_offset, | |
41 | struct page *src_page, int src_offset, int size, | |
42 | unsigned char *iv); | |
43 | static int | |
44 | ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
45 | struct page *dst_page, int dst_offset, | |
46 | struct page *src_page, int src_offset, int size, | |
47 | unsigned char *iv); | |
48 | ||
49 | /** | |
50 | * ecryptfs_to_hex | |
51 | * @dst: Buffer to take hex character representation of contents of | |
52 | * src; must be at least of size (src_size * 2) | |
53 | * @src: Buffer to be converted to a hex string respresentation | |
54 | * @src_size: number of bytes to convert | |
55 | */ | |
56 | void ecryptfs_to_hex(char *dst, char *src, size_t src_size) | |
57 | { | |
58 | int x; | |
59 | ||
60 | for (x = 0; x < src_size; x++) | |
61 | sprintf(&dst[x * 2], "%.2x", (unsigned char)src[x]); | |
62 | } | |
63 | ||
64 | /** | |
65 | * ecryptfs_from_hex | |
66 | * @dst: Buffer to take the bytes from src hex; must be at least of | |
67 | * size (src_size / 2) | |
68 | * @src: Buffer to be converted from a hex string respresentation to raw value | |
69 | * @dst_size: size of dst buffer, or number of hex characters pairs to convert | |
70 | */ | |
71 | void ecryptfs_from_hex(char *dst, char *src, int dst_size) | |
72 | { | |
73 | int x; | |
74 | char tmp[3] = { 0, }; | |
75 | ||
76 | for (x = 0; x < dst_size; x++) { | |
77 | tmp[0] = src[x * 2]; | |
78 | tmp[1] = src[x * 2 + 1]; | |
79 | dst[x] = (unsigned char)simple_strtol(tmp, NULL, 16); | |
80 | } | |
81 | } | |
82 | ||
83 | /** | |
84 | * ecryptfs_calculate_md5 - calculates the md5 of @src | |
85 | * @dst: Pointer to 16 bytes of allocated memory | |
86 | * @crypt_stat: Pointer to crypt_stat struct for the current inode | |
87 | * @src: Data to be md5'd | |
88 | * @len: Length of @src | |
89 | * | |
90 | * Uses the allocated crypto context that crypt_stat references to | |
91 | * generate the MD5 sum of the contents of src. | |
92 | */ | |
93 | static int ecryptfs_calculate_md5(char *dst, | |
94 | struct ecryptfs_crypt_stat *crypt_stat, | |
95 | char *src, int len) | |
96 | { | |
237fead6 | 97 | struct scatterlist sg; |
565d9724 MH |
98 | struct hash_desc desc = { |
99 | .tfm = crypt_stat->hash_tfm, | |
100 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
101 | }; | |
102 | int rc = 0; | |
237fead6 | 103 | |
565d9724 | 104 | mutex_lock(&crypt_stat->cs_hash_tfm_mutex); |
237fead6 | 105 | sg_init_one(&sg, (u8 *)src, len); |
565d9724 MH |
106 | if (!desc.tfm) { |
107 | desc.tfm = crypto_alloc_hash(ECRYPTFS_DEFAULT_HASH, 0, | |
108 | CRYPTO_ALG_ASYNC); | |
109 | if (IS_ERR(desc.tfm)) { | |
110 | rc = PTR_ERR(desc.tfm); | |
237fead6 | 111 | ecryptfs_printk(KERN_ERR, "Error attempting to " |
565d9724 MH |
112 | "allocate crypto context; rc = [%d]\n", |
113 | rc); | |
237fead6 MH |
114 | goto out; |
115 | } | |
565d9724 | 116 | crypt_stat->hash_tfm = desc.tfm; |
237fead6 | 117 | } |
565d9724 MH |
118 | crypto_hash_init(&desc); |
119 | crypto_hash_update(&desc, &sg, len); | |
120 | crypto_hash_final(&desc, dst); | |
121 | mutex_unlock(&crypt_stat->cs_hash_tfm_mutex); | |
237fead6 MH |
122 | out: |
123 | return rc; | |
124 | } | |
125 | ||
cd9d67df MH |
126 | static int ecryptfs_crypto_api_algify_cipher_name(char **algified_name, |
127 | char *cipher_name, | |
128 | char *chaining_modifier) | |
8bba066f MH |
129 | { |
130 | int cipher_name_len = strlen(cipher_name); | |
131 | int chaining_modifier_len = strlen(chaining_modifier); | |
132 | int algified_name_len; | |
133 | int rc; | |
134 | ||
135 | algified_name_len = (chaining_modifier_len + cipher_name_len + 3); | |
136 | (*algified_name) = kmalloc(algified_name_len, GFP_KERNEL); | |
7bd473fc | 137 | if (!(*algified_name)) { |
8bba066f MH |
138 | rc = -ENOMEM; |
139 | goto out; | |
140 | } | |
141 | snprintf((*algified_name), algified_name_len, "%s(%s)", | |
142 | chaining_modifier, cipher_name); | |
143 | rc = 0; | |
144 | out: | |
145 | return rc; | |
146 | } | |
147 | ||
237fead6 MH |
148 | /** |
149 | * ecryptfs_derive_iv | |
150 | * @iv: destination for the derived iv vale | |
151 | * @crypt_stat: Pointer to crypt_stat struct for the current inode | |
d6a13c17 | 152 | * @offset: Offset of the extent whose IV we are to derive |
237fead6 MH |
153 | * |
154 | * Generate the initialization vector from the given root IV and page | |
155 | * offset. | |
156 | * | |
157 | * Returns zero on success; non-zero on error. | |
158 | */ | |
159 | static int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat, | |
d6a13c17 | 160 | loff_t offset) |
237fead6 MH |
161 | { |
162 | int rc = 0; | |
163 | char dst[MD5_DIGEST_SIZE]; | |
164 | char src[ECRYPTFS_MAX_IV_BYTES + 16]; | |
165 | ||
166 | if (unlikely(ecryptfs_verbosity > 0)) { | |
167 | ecryptfs_printk(KERN_DEBUG, "root iv:\n"); | |
168 | ecryptfs_dump_hex(crypt_stat->root_iv, crypt_stat->iv_bytes); | |
169 | } | |
170 | /* TODO: It is probably secure to just cast the least | |
171 | * significant bits of the root IV into an unsigned long and | |
172 | * add the offset to that rather than go through all this | |
173 | * hashing business. -Halcrow */ | |
174 | memcpy(src, crypt_stat->root_iv, crypt_stat->iv_bytes); | |
175 | memset((src + crypt_stat->iv_bytes), 0, 16); | |
d6a13c17 | 176 | snprintf((src + crypt_stat->iv_bytes), 16, "%lld", offset); |
237fead6 MH |
177 | if (unlikely(ecryptfs_verbosity > 0)) { |
178 | ecryptfs_printk(KERN_DEBUG, "source:\n"); | |
179 | ecryptfs_dump_hex(src, (crypt_stat->iv_bytes + 16)); | |
180 | } | |
181 | rc = ecryptfs_calculate_md5(dst, crypt_stat, src, | |
182 | (crypt_stat->iv_bytes + 16)); | |
183 | if (rc) { | |
184 | ecryptfs_printk(KERN_WARNING, "Error attempting to compute " | |
185 | "MD5 while generating IV for a page\n"); | |
186 | goto out; | |
187 | } | |
188 | memcpy(iv, dst, crypt_stat->iv_bytes); | |
189 | if (unlikely(ecryptfs_verbosity > 0)) { | |
190 | ecryptfs_printk(KERN_DEBUG, "derived iv:\n"); | |
191 | ecryptfs_dump_hex(iv, crypt_stat->iv_bytes); | |
192 | } | |
193 | out: | |
194 | return rc; | |
195 | } | |
196 | ||
197 | /** | |
198 | * ecryptfs_init_crypt_stat | |
199 | * @crypt_stat: Pointer to the crypt_stat struct to initialize. | |
200 | * | |
201 | * Initialize the crypt_stat structure. | |
202 | */ | |
203 | void | |
204 | ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat) | |
205 | { | |
206 | memset((void *)crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat)); | |
f4aad16a MH |
207 | INIT_LIST_HEAD(&crypt_stat->keysig_list); |
208 | mutex_init(&crypt_stat->keysig_list_mutex); | |
237fead6 MH |
209 | mutex_init(&crypt_stat->cs_mutex); |
210 | mutex_init(&crypt_stat->cs_tfm_mutex); | |
565d9724 | 211 | mutex_init(&crypt_stat->cs_hash_tfm_mutex); |
e2bd99ec | 212 | crypt_stat->flags |= ECRYPTFS_STRUCT_INITIALIZED; |
237fead6 MH |
213 | } |
214 | ||
215 | /** | |
fcd12835 | 216 | * ecryptfs_destroy_crypt_stat |
237fead6 MH |
217 | * @crypt_stat: Pointer to the crypt_stat struct to initialize. |
218 | * | |
219 | * Releases all memory associated with a crypt_stat struct. | |
220 | */ | |
fcd12835 | 221 | void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat) |
237fead6 | 222 | { |
f4aad16a MH |
223 | struct ecryptfs_key_sig *key_sig, *key_sig_tmp; |
224 | ||
237fead6 | 225 | if (crypt_stat->tfm) |
8bba066f | 226 | crypto_free_blkcipher(crypt_stat->tfm); |
565d9724 MH |
227 | if (crypt_stat->hash_tfm) |
228 | crypto_free_hash(crypt_stat->hash_tfm); | |
f4aad16a MH |
229 | mutex_lock(&crypt_stat->keysig_list_mutex); |
230 | list_for_each_entry_safe(key_sig, key_sig_tmp, | |
231 | &crypt_stat->keysig_list, crypt_stat_list) { | |
232 | list_del(&key_sig->crypt_stat_list); | |
233 | kmem_cache_free(ecryptfs_key_sig_cache, key_sig); | |
234 | } | |
235 | mutex_unlock(&crypt_stat->keysig_list_mutex); | |
237fead6 MH |
236 | memset(crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat)); |
237 | } | |
238 | ||
fcd12835 | 239 | void ecryptfs_destroy_mount_crypt_stat( |
237fead6 MH |
240 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) |
241 | { | |
f4aad16a MH |
242 | struct ecryptfs_global_auth_tok *auth_tok, *auth_tok_tmp; |
243 | ||
244 | if (!(mount_crypt_stat->flags & ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED)) | |
245 | return; | |
246 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
247 | list_for_each_entry_safe(auth_tok, auth_tok_tmp, | |
248 | &mount_crypt_stat->global_auth_tok_list, | |
249 | mount_crypt_stat_list) { | |
250 | list_del(&auth_tok->mount_crypt_stat_list); | |
251 | mount_crypt_stat->num_global_auth_toks--; | |
252 | if (auth_tok->global_auth_tok_key | |
253 | && !(auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID)) | |
254 | key_put(auth_tok->global_auth_tok_key); | |
255 | kmem_cache_free(ecryptfs_global_auth_tok_cache, auth_tok); | |
256 | } | |
257 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
237fead6 MH |
258 | memset(mount_crypt_stat, 0, sizeof(struct ecryptfs_mount_crypt_stat)); |
259 | } | |
260 | ||
261 | /** | |
262 | * virt_to_scatterlist | |
263 | * @addr: Virtual address | |
264 | * @size: Size of data; should be an even multiple of the block size | |
265 | * @sg: Pointer to scatterlist array; set to NULL to obtain only | |
266 | * the number of scatterlist structs required in array | |
267 | * @sg_size: Max array size | |
268 | * | |
269 | * Fills in a scatterlist array with page references for a passed | |
270 | * virtual address. | |
271 | * | |
272 | * Returns the number of scatterlist structs in array used | |
273 | */ | |
274 | int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg, | |
275 | int sg_size) | |
276 | { | |
277 | int i = 0; | |
278 | struct page *pg; | |
279 | int offset; | |
280 | int remainder_of_page; | |
281 | ||
68e3f5dd HX |
282 | sg_init_table(sg, sg_size); |
283 | ||
237fead6 MH |
284 | while (size > 0 && i < sg_size) { |
285 | pg = virt_to_page(addr); | |
286 | offset = offset_in_page(addr); | |
642f1490 JA |
287 | if (sg) |
288 | sg_set_page(&sg[i], pg, 0, offset); | |
237fead6 MH |
289 | remainder_of_page = PAGE_CACHE_SIZE - offset; |
290 | if (size >= remainder_of_page) { | |
291 | if (sg) | |
292 | sg[i].length = remainder_of_page; | |
293 | addr += remainder_of_page; | |
294 | size -= remainder_of_page; | |
295 | } else { | |
296 | if (sg) | |
297 | sg[i].length = size; | |
298 | addr += size; | |
299 | size = 0; | |
300 | } | |
301 | i++; | |
302 | } | |
303 | if (size > 0) | |
304 | return -ENOMEM; | |
305 | return i; | |
306 | } | |
307 | ||
308 | /** | |
309 | * encrypt_scatterlist | |
310 | * @crypt_stat: Pointer to the crypt_stat struct to initialize. | |
311 | * @dest_sg: Destination of encrypted data | |
312 | * @src_sg: Data to be encrypted | |
313 | * @size: Length of data to be encrypted | |
314 | * @iv: iv to use during encryption | |
315 | * | |
316 | * Returns the number of bytes encrypted; negative value on error | |
317 | */ | |
318 | static int encrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, | |
319 | struct scatterlist *dest_sg, | |
320 | struct scatterlist *src_sg, int size, | |
321 | unsigned char *iv) | |
322 | { | |
8bba066f MH |
323 | struct blkcipher_desc desc = { |
324 | .tfm = crypt_stat->tfm, | |
325 | .info = iv, | |
326 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
327 | }; | |
237fead6 MH |
328 | int rc = 0; |
329 | ||
330 | BUG_ON(!crypt_stat || !crypt_stat->tfm | |
e2bd99ec | 331 | || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)); |
237fead6 MH |
332 | if (unlikely(ecryptfs_verbosity > 0)) { |
333 | ecryptfs_printk(KERN_DEBUG, "Key size [%d]; key:\n", | |
334 | crypt_stat->key_size); | |
335 | ecryptfs_dump_hex(crypt_stat->key, | |
336 | crypt_stat->key_size); | |
337 | } | |
338 | /* Consider doing this once, when the file is opened */ | |
339 | mutex_lock(&crypt_stat->cs_tfm_mutex); | |
8bba066f MH |
340 | rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key, |
341 | crypt_stat->key_size); | |
237fead6 MH |
342 | if (rc) { |
343 | ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n", | |
344 | rc); | |
345 | mutex_unlock(&crypt_stat->cs_tfm_mutex); | |
346 | rc = -EINVAL; | |
347 | goto out; | |
348 | } | |
349 | ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes.\n", size); | |
8bba066f | 350 | crypto_blkcipher_encrypt_iv(&desc, dest_sg, src_sg, size); |
237fead6 MH |
351 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
352 | out: | |
353 | return rc; | |
354 | } | |
355 | ||
0216f7f7 MH |
356 | /** |
357 | * ecryptfs_lower_offset_for_extent | |
358 | * | |
359 | * Convert an eCryptfs page index into a lower byte offset | |
360 | */ | |
361 | void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num, | |
362 | struct ecryptfs_crypt_stat *crypt_stat) | |
363 | { | |
364 | (*offset) = ((crypt_stat->extent_size | |
365 | * crypt_stat->num_header_extents_at_front) | |
366 | + (crypt_stat->extent_size * extent_num)); | |
367 | } | |
368 | ||
369 | /** | |
370 | * ecryptfs_encrypt_extent | |
371 | * @enc_extent_page: Allocated page into which to encrypt the data in | |
372 | * @page | |
373 | * @crypt_stat: crypt_stat containing cryptographic context for the | |
374 | * encryption operation | |
375 | * @page: Page containing plaintext data extent to encrypt | |
376 | * @extent_offset: Page extent offset for use in generating IV | |
377 | * | |
378 | * Encrypts one extent of data. | |
379 | * | |
380 | * Return zero on success; non-zero otherwise | |
381 | */ | |
382 | static int ecryptfs_encrypt_extent(struct page *enc_extent_page, | |
383 | struct ecryptfs_crypt_stat *crypt_stat, | |
384 | struct page *page, | |
385 | unsigned long extent_offset) | |
386 | { | |
d6a13c17 | 387 | loff_t extent_base; |
0216f7f7 MH |
388 | char extent_iv[ECRYPTFS_MAX_IV_BYTES]; |
389 | int rc; | |
390 | ||
d6a13c17 | 391 | extent_base = (((loff_t)page->index) |
0216f7f7 MH |
392 | * (PAGE_CACHE_SIZE / crypt_stat->extent_size)); |
393 | rc = ecryptfs_derive_iv(extent_iv, crypt_stat, | |
394 | (extent_base + extent_offset)); | |
395 | if (rc) { | |
396 | ecryptfs_printk(KERN_ERR, "Error attempting to " | |
397 | "derive IV for extent [0x%.16x]; " | |
398 | "rc = [%d]\n", (extent_base + extent_offset), | |
399 | rc); | |
400 | goto out; | |
401 | } | |
402 | if (unlikely(ecryptfs_verbosity > 0)) { | |
403 | ecryptfs_printk(KERN_DEBUG, "Encrypting extent " | |
404 | "with iv:\n"); | |
405 | ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes); | |
406 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes before " | |
407 | "encryption:\n"); | |
408 | ecryptfs_dump_hex((char *) | |
409 | (page_address(page) | |
410 | + (extent_offset * crypt_stat->extent_size)), | |
411 | 8); | |
412 | } | |
413 | rc = ecryptfs_encrypt_page_offset(crypt_stat, enc_extent_page, 0, | |
414 | page, (extent_offset | |
415 | * crypt_stat->extent_size), | |
416 | crypt_stat->extent_size, extent_iv); | |
417 | if (rc < 0) { | |
418 | printk(KERN_ERR "%s: Error attempting to encrypt page with " | |
419 | "page->index = [%ld], extent_offset = [%ld]; " | |
420 | "rc = [%d]\n", __FUNCTION__, page->index, extent_offset, | |
421 | rc); | |
422 | goto out; | |
423 | } | |
424 | rc = 0; | |
425 | if (unlikely(ecryptfs_verbosity > 0)) { | |
426 | ecryptfs_printk(KERN_DEBUG, "Encrypt extent [0x%.16x]; " | |
427 | "rc = [%d]\n", (extent_base + extent_offset), | |
428 | rc); | |
429 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes after " | |
430 | "encryption:\n"); | |
431 | ecryptfs_dump_hex((char *)(page_address(enc_extent_page)), 8); | |
432 | } | |
433 | out: | |
434 | return rc; | |
435 | } | |
436 | ||
237fead6 MH |
437 | /** |
438 | * ecryptfs_encrypt_page | |
0216f7f7 MH |
439 | * @page: Page mapped from the eCryptfs inode for the file; contains |
440 | * decrypted content that needs to be encrypted (to a temporary | |
441 | * page; not in place) and written out to the lower file | |
237fead6 MH |
442 | * |
443 | * Encrypt an eCryptfs page. This is done on a per-extent basis. Note | |
444 | * that eCryptfs pages may straddle the lower pages -- for instance, | |
445 | * if the file was created on a machine with an 8K page size | |
446 | * (resulting in an 8K header), and then the file is copied onto a | |
447 | * host with a 32K page size, then when reading page 0 of the eCryptfs | |
448 | * file, 24K of page 0 of the lower file will be read and decrypted, | |
449 | * and then 8K of page 1 of the lower file will be read and decrypted. | |
450 | * | |
237fead6 MH |
451 | * Returns zero on success; negative on error |
452 | */ | |
0216f7f7 | 453 | int ecryptfs_encrypt_page(struct page *page) |
237fead6 | 454 | { |
0216f7f7 | 455 | struct inode *ecryptfs_inode; |
237fead6 | 456 | struct ecryptfs_crypt_stat *crypt_stat; |
0216f7f7 MH |
457 | char *enc_extent_virt = NULL; |
458 | struct page *enc_extent_page; | |
459 | loff_t extent_offset; | |
237fead6 | 460 | int rc = 0; |
0216f7f7 MH |
461 | |
462 | ecryptfs_inode = page->mapping->host; | |
463 | crypt_stat = | |
464 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); | |
e2bd99ec | 465 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
0216f7f7 MH |
466 | rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page, |
467 | 0, PAGE_CACHE_SIZE); | |
237fead6 | 468 | if (rc) |
0216f7f7 MH |
469 | printk(KERN_ERR "%s: Error attempting to copy " |
470 | "page at index [%ld]\n", __FUNCTION__, | |
471 | page->index); | |
237fead6 MH |
472 | goto out; |
473 | } | |
0216f7f7 MH |
474 | enc_extent_virt = kmalloc(PAGE_CACHE_SIZE, GFP_USER); |
475 | if (!enc_extent_virt) { | |
476 | rc = -ENOMEM; | |
477 | ecryptfs_printk(KERN_ERR, "Error allocating memory for " | |
478 | "encrypted extent\n"); | |
479 | goto out; | |
480 | } | |
481 | enc_extent_page = virt_to_page(enc_extent_virt); | |
482 | for (extent_offset = 0; | |
483 | extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); | |
484 | extent_offset++) { | |
485 | loff_t offset; | |
486 | ||
487 | rc = ecryptfs_encrypt_extent(enc_extent_page, crypt_stat, page, | |
488 | extent_offset); | |
237fead6 | 489 | if (rc) { |
0216f7f7 MH |
490 | printk(KERN_ERR "%s: Error encrypting extent; " |
491 | "rc = [%d]\n", __FUNCTION__, rc); | |
237fead6 MH |
492 | goto out; |
493 | } | |
0216f7f7 | 494 | ecryptfs_lower_offset_for_extent( |
d6a13c17 MH |
495 | &offset, ((((loff_t)page->index) |
496 | * (PAGE_CACHE_SIZE | |
497 | / crypt_stat->extent_size)) | |
0216f7f7 MH |
498 | + extent_offset), crypt_stat); |
499 | rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt, | |
500 | offset, crypt_stat->extent_size); | |
501 | if (rc) { | |
502 | ecryptfs_printk(KERN_ERR, "Error attempting " | |
503 | "to write lower page; rc = [%d]" | |
504 | "\n", rc); | |
505 | goto out; | |
237fead6 | 506 | } |
237fead6 MH |
507 | extent_offset++; |
508 | } | |
0216f7f7 MH |
509 | out: |
510 | kfree(enc_extent_virt); | |
511 | return rc; | |
512 | } | |
513 | ||
514 | static int ecryptfs_decrypt_extent(struct page *page, | |
515 | struct ecryptfs_crypt_stat *crypt_stat, | |
516 | struct page *enc_extent_page, | |
517 | unsigned long extent_offset) | |
518 | { | |
d6a13c17 | 519 | loff_t extent_base; |
0216f7f7 MH |
520 | char extent_iv[ECRYPTFS_MAX_IV_BYTES]; |
521 | int rc; | |
522 | ||
d6a13c17 | 523 | extent_base = (((loff_t)page->index) |
0216f7f7 MH |
524 | * (PAGE_CACHE_SIZE / crypt_stat->extent_size)); |
525 | rc = ecryptfs_derive_iv(extent_iv, crypt_stat, | |
526 | (extent_base + extent_offset)); | |
237fead6 | 527 | if (rc) { |
0216f7f7 MH |
528 | ecryptfs_printk(KERN_ERR, "Error attempting to " |
529 | "derive IV for extent [0x%.16x]; " | |
530 | "rc = [%d]\n", (extent_base + extent_offset), | |
531 | rc); | |
532 | goto out; | |
533 | } | |
534 | if (unlikely(ecryptfs_verbosity > 0)) { | |
535 | ecryptfs_printk(KERN_DEBUG, "Decrypting extent " | |
536 | "with iv:\n"); | |
537 | ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes); | |
538 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes before " | |
539 | "decryption:\n"); | |
540 | ecryptfs_dump_hex((char *) | |
541 | (page_address(enc_extent_page) | |
542 | + (extent_offset * crypt_stat->extent_size)), | |
543 | 8); | |
544 | } | |
545 | rc = ecryptfs_decrypt_page_offset(crypt_stat, page, | |
546 | (extent_offset | |
547 | * crypt_stat->extent_size), | |
548 | enc_extent_page, 0, | |
549 | crypt_stat->extent_size, extent_iv); | |
550 | if (rc < 0) { | |
551 | printk(KERN_ERR "%s: Error attempting to decrypt to page with " | |
552 | "page->index = [%ld], extent_offset = [%ld]; " | |
553 | "rc = [%d]\n", __FUNCTION__, page->index, extent_offset, | |
554 | rc); | |
555 | goto out; | |
556 | } | |
557 | rc = 0; | |
558 | if (unlikely(ecryptfs_verbosity > 0)) { | |
559 | ecryptfs_printk(KERN_DEBUG, "Decrypt extent [0x%.16x]; " | |
560 | "rc = [%d]\n", (extent_base + extent_offset), | |
561 | rc); | |
562 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes after " | |
563 | "decryption:\n"); | |
564 | ecryptfs_dump_hex((char *)(page_address(page) | |
565 | + (extent_offset | |
566 | * crypt_stat->extent_size)), 8); | |
237fead6 MH |
567 | } |
568 | out: | |
569 | return rc; | |
570 | } | |
571 | ||
572 | /** | |
573 | * ecryptfs_decrypt_page | |
0216f7f7 MH |
574 | * @page: Page mapped from the eCryptfs inode for the file; data read |
575 | * and decrypted from the lower file will be written into this | |
576 | * page | |
237fead6 MH |
577 | * |
578 | * Decrypt an eCryptfs page. This is done on a per-extent basis. Note | |
579 | * that eCryptfs pages may straddle the lower pages -- for instance, | |
580 | * if the file was created on a machine with an 8K page size | |
581 | * (resulting in an 8K header), and then the file is copied onto a | |
582 | * host with a 32K page size, then when reading page 0 of the eCryptfs | |
583 | * file, 24K of page 0 of the lower file will be read and decrypted, | |
584 | * and then 8K of page 1 of the lower file will be read and decrypted. | |
585 | * | |
586 | * Returns zero on success; negative on error | |
587 | */ | |
0216f7f7 | 588 | int ecryptfs_decrypt_page(struct page *page) |
237fead6 | 589 | { |
0216f7f7 | 590 | struct inode *ecryptfs_inode; |
237fead6 | 591 | struct ecryptfs_crypt_stat *crypt_stat; |
0216f7f7 MH |
592 | char *enc_extent_virt = NULL; |
593 | struct page *enc_extent_page; | |
594 | unsigned long extent_offset; | |
237fead6 | 595 | int rc = 0; |
237fead6 | 596 | |
0216f7f7 MH |
597 | ecryptfs_inode = page->mapping->host; |
598 | crypt_stat = | |
599 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); | |
e2bd99ec | 600 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
0216f7f7 MH |
601 | rc = ecryptfs_read_lower_page_segment(page, page->index, 0, |
602 | PAGE_CACHE_SIZE, | |
603 | ecryptfs_inode); | |
237fead6 | 604 | if (rc) |
0216f7f7 MH |
605 | printk(KERN_ERR "%s: Error attempting to copy " |
606 | "page at index [%ld]\n", __FUNCTION__, | |
607 | page->index); | |
16a72c45 | 608 | goto out; |
237fead6 | 609 | } |
0216f7f7 MH |
610 | enc_extent_virt = kmalloc(PAGE_CACHE_SIZE, GFP_USER); |
611 | if (!enc_extent_virt) { | |
237fead6 | 612 | rc = -ENOMEM; |
0216f7f7 MH |
613 | ecryptfs_printk(KERN_ERR, "Error allocating memory for " |
614 | "encrypted extent\n"); | |
16a72c45 | 615 | goto out; |
237fead6 | 616 | } |
0216f7f7 MH |
617 | enc_extent_page = virt_to_page(enc_extent_virt); |
618 | for (extent_offset = 0; | |
619 | extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); | |
620 | extent_offset++) { | |
621 | loff_t offset; | |
622 | ||
623 | ecryptfs_lower_offset_for_extent( | |
624 | &offset, ((page->index * (PAGE_CACHE_SIZE | |
625 | / crypt_stat->extent_size)) | |
626 | + extent_offset), crypt_stat); | |
627 | rc = ecryptfs_read_lower(enc_extent_virt, offset, | |
628 | crypt_stat->extent_size, | |
629 | ecryptfs_inode); | |
237fead6 | 630 | if (rc) { |
0216f7f7 MH |
631 | ecryptfs_printk(KERN_ERR, "Error attempting " |
632 | "to read lower page; rc = [%d]" | |
633 | "\n", rc); | |
16a72c45 | 634 | goto out; |
237fead6 | 635 | } |
0216f7f7 MH |
636 | rc = ecryptfs_decrypt_extent(page, crypt_stat, enc_extent_page, |
637 | extent_offset); | |
638 | if (rc) { | |
639 | printk(KERN_ERR "%s: Error encrypting extent; " | |
640 | "rc = [%d]\n", __FUNCTION__, rc); | |
16a72c45 | 641 | goto out; |
237fead6 MH |
642 | } |
643 | extent_offset++; | |
644 | } | |
645 | out: | |
0216f7f7 | 646 | kfree(enc_extent_virt); |
237fead6 MH |
647 | return rc; |
648 | } | |
649 | ||
650 | /** | |
651 | * decrypt_scatterlist | |
22e78faf MH |
652 | * @crypt_stat: Cryptographic context |
653 | * @dest_sg: The destination scatterlist to decrypt into | |
654 | * @src_sg: The source scatterlist to decrypt from | |
655 | * @size: The number of bytes to decrypt | |
656 | * @iv: The initialization vector to use for the decryption | |
237fead6 MH |
657 | * |
658 | * Returns the number of bytes decrypted; negative value on error | |
659 | */ | |
660 | static int decrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, | |
661 | struct scatterlist *dest_sg, | |
662 | struct scatterlist *src_sg, int size, | |
663 | unsigned char *iv) | |
664 | { | |
8bba066f MH |
665 | struct blkcipher_desc desc = { |
666 | .tfm = crypt_stat->tfm, | |
667 | .info = iv, | |
668 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
669 | }; | |
237fead6 MH |
670 | int rc = 0; |
671 | ||
672 | /* Consider doing this once, when the file is opened */ | |
673 | mutex_lock(&crypt_stat->cs_tfm_mutex); | |
8bba066f MH |
674 | rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key, |
675 | crypt_stat->key_size); | |
237fead6 MH |
676 | if (rc) { |
677 | ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n", | |
678 | rc); | |
679 | mutex_unlock(&crypt_stat->cs_tfm_mutex); | |
680 | rc = -EINVAL; | |
681 | goto out; | |
682 | } | |
683 | ecryptfs_printk(KERN_DEBUG, "Decrypting [%d] bytes.\n", size); | |
8bba066f | 684 | rc = crypto_blkcipher_decrypt_iv(&desc, dest_sg, src_sg, size); |
237fead6 MH |
685 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
686 | if (rc) { | |
687 | ecryptfs_printk(KERN_ERR, "Error decrypting; rc = [%d]\n", | |
688 | rc); | |
689 | goto out; | |
690 | } | |
691 | rc = size; | |
692 | out: | |
693 | return rc; | |
694 | } | |
695 | ||
696 | /** | |
697 | * ecryptfs_encrypt_page_offset | |
22e78faf MH |
698 | * @crypt_stat: The cryptographic context |
699 | * @dst_page: The page to encrypt into | |
700 | * @dst_offset: The offset in the page to encrypt into | |
701 | * @src_page: The page to encrypt from | |
702 | * @src_offset: The offset in the page to encrypt from | |
703 | * @size: The number of bytes to encrypt | |
704 | * @iv: The initialization vector to use for the encryption | |
237fead6 MH |
705 | * |
706 | * Returns the number of bytes encrypted | |
707 | */ | |
708 | static int | |
709 | ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
710 | struct page *dst_page, int dst_offset, | |
711 | struct page *src_page, int src_offset, int size, | |
712 | unsigned char *iv) | |
713 | { | |
714 | struct scatterlist src_sg, dst_sg; | |
715 | ||
60c74f81 JA |
716 | sg_init_table(&src_sg, 1); |
717 | sg_init_table(&dst_sg, 1); | |
718 | ||
642f1490 JA |
719 | sg_set_page(&src_sg, src_page, size, src_offset); |
720 | sg_set_page(&dst_sg, dst_page, size, dst_offset); | |
237fead6 MH |
721 | return encrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); |
722 | } | |
723 | ||
724 | /** | |
725 | * ecryptfs_decrypt_page_offset | |
22e78faf MH |
726 | * @crypt_stat: The cryptographic context |
727 | * @dst_page: The page to decrypt into | |
728 | * @dst_offset: The offset in the page to decrypt into | |
729 | * @src_page: The page to decrypt from | |
730 | * @src_offset: The offset in the page to decrypt from | |
731 | * @size: The number of bytes to decrypt | |
732 | * @iv: The initialization vector to use for the decryption | |
237fead6 MH |
733 | * |
734 | * Returns the number of bytes decrypted | |
735 | */ | |
736 | static int | |
737 | ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
738 | struct page *dst_page, int dst_offset, | |
739 | struct page *src_page, int src_offset, int size, | |
740 | unsigned char *iv) | |
741 | { | |
742 | struct scatterlist src_sg, dst_sg; | |
743 | ||
60c74f81 | 744 | sg_init_table(&src_sg, 1); |
642f1490 JA |
745 | sg_set_page(&src_sg, src_page, size, src_offset); |
746 | ||
60c74f81 | 747 | sg_init_table(&dst_sg, 1); |
642f1490 | 748 | sg_set_page(&dst_sg, dst_page, size, dst_offset); |
60c74f81 | 749 | |
237fead6 MH |
750 | return decrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); |
751 | } | |
752 | ||
753 | #define ECRYPTFS_MAX_SCATTERLIST_LEN 4 | |
754 | ||
755 | /** | |
756 | * ecryptfs_init_crypt_ctx | |
757 | * @crypt_stat: Uninitilized crypt stats structure | |
758 | * | |
759 | * Initialize the crypto context. | |
760 | * | |
761 | * TODO: Performance: Keep a cache of initialized cipher contexts; | |
762 | * only init if needed | |
763 | */ | |
764 | int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat) | |
765 | { | |
8bba066f | 766 | char *full_alg_name; |
237fead6 MH |
767 | int rc = -EINVAL; |
768 | ||
769 | if (!crypt_stat->cipher) { | |
770 | ecryptfs_printk(KERN_ERR, "No cipher specified\n"); | |
771 | goto out; | |
772 | } | |
773 | ecryptfs_printk(KERN_DEBUG, | |
774 | "Initializing cipher [%s]; strlen = [%d]; " | |
775 | "key_size_bits = [%d]\n", | |
776 | crypt_stat->cipher, (int)strlen(crypt_stat->cipher), | |
777 | crypt_stat->key_size << 3); | |
778 | if (crypt_stat->tfm) { | |
779 | rc = 0; | |
780 | goto out; | |
781 | } | |
782 | mutex_lock(&crypt_stat->cs_tfm_mutex); | |
8bba066f MH |
783 | rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, |
784 | crypt_stat->cipher, "cbc"); | |
785 | if (rc) | |
786 | goto out; | |
787 | crypt_stat->tfm = crypto_alloc_blkcipher(full_alg_name, 0, | |
788 | CRYPTO_ALG_ASYNC); | |
789 | kfree(full_alg_name); | |
de88777e AM |
790 | if (IS_ERR(crypt_stat->tfm)) { |
791 | rc = PTR_ERR(crypt_stat->tfm); | |
237fead6 MH |
792 | ecryptfs_printk(KERN_ERR, "cryptfs: init_crypt_ctx(): " |
793 | "Error initializing cipher [%s]\n", | |
794 | crypt_stat->cipher); | |
8bba066f | 795 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
237fead6 MH |
796 | goto out; |
797 | } | |
f1ddcaf3 | 798 | crypto_blkcipher_set_flags(crypt_stat->tfm, CRYPTO_TFM_REQ_WEAK_KEY); |
8bba066f | 799 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
237fead6 MH |
800 | rc = 0; |
801 | out: | |
802 | return rc; | |
803 | } | |
804 | ||
805 | static void set_extent_mask_and_shift(struct ecryptfs_crypt_stat *crypt_stat) | |
806 | { | |
807 | int extent_size_tmp; | |
808 | ||
809 | crypt_stat->extent_mask = 0xFFFFFFFF; | |
810 | crypt_stat->extent_shift = 0; | |
811 | if (crypt_stat->extent_size == 0) | |
812 | return; | |
813 | extent_size_tmp = crypt_stat->extent_size; | |
814 | while ((extent_size_tmp & 0x01) == 0) { | |
815 | extent_size_tmp >>= 1; | |
816 | crypt_stat->extent_mask <<= 1; | |
817 | crypt_stat->extent_shift++; | |
818 | } | |
819 | } | |
820 | ||
821 | void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat) | |
822 | { | |
823 | /* Default values; may be overwritten as we are parsing the | |
824 | * packets. */ | |
825 | crypt_stat->extent_size = ECRYPTFS_DEFAULT_EXTENT_SIZE; | |
826 | set_extent_mask_and_shift(crypt_stat); | |
827 | crypt_stat->iv_bytes = ECRYPTFS_DEFAULT_IV_BYTES; | |
dd2a3b7a MH |
828 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
829 | crypt_stat->num_header_extents_at_front = 0; | |
45eaab79 MH |
830 | else { |
831 | if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE) | |
832 | crypt_stat->num_header_extents_at_front = | |
833 | (ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE | |
834 | / crypt_stat->extent_size); | |
835 | else | |
836 | crypt_stat->num_header_extents_at_front = | |
837 | (PAGE_CACHE_SIZE / crypt_stat->extent_size); | |
838 | } | |
237fead6 MH |
839 | } |
840 | ||
841 | /** | |
842 | * ecryptfs_compute_root_iv | |
843 | * @crypt_stats | |
844 | * | |
845 | * On error, sets the root IV to all 0's. | |
846 | */ | |
847 | int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat) | |
848 | { | |
849 | int rc = 0; | |
850 | char dst[MD5_DIGEST_SIZE]; | |
851 | ||
852 | BUG_ON(crypt_stat->iv_bytes > MD5_DIGEST_SIZE); | |
853 | BUG_ON(crypt_stat->iv_bytes <= 0); | |
e2bd99ec | 854 | if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { |
237fead6 MH |
855 | rc = -EINVAL; |
856 | ecryptfs_printk(KERN_WARNING, "Session key not valid; " | |
857 | "cannot generate root IV\n"); | |
858 | goto out; | |
859 | } | |
860 | rc = ecryptfs_calculate_md5(dst, crypt_stat, crypt_stat->key, | |
861 | crypt_stat->key_size); | |
862 | if (rc) { | |
863 | ecryptfs_printk(KERN_WARNING, "Error attempting to compute " | |
864 | "MD5 while generating root IV\n"); | |
865 | goto out; | |
866 | } | |
867 | memcpy(crypt_stat->root_iv, dst, crypt_stat->iv_bytes); | |
868 | out: | |
869 | if (rc) { | |
870 | memset(crypt_stat->root_iv, 0, crypt_stat->iv_bytes); | |
e2bd99ec | 871 | crypt_stat->flags |= ECRYPTFS_SECURITY_WARNING; |
237fead6 MH |
872 | } |
873 | return rc; | |
874 | } | |
875 | ||
876 | static void ecryptfs_generate_new_key(struct ecryptfs_crypt_stat *crypt_stat) | |
877 | { | |
878 | get_random_bytes(crypt_stat->key, crypt_stat->key_size); | |
e2bd99ec | 879 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; |
237fead6 MH |
880 | ecryptfs_compute_root_iv(crypt_stat); |
881 | if (unlikely(ecryptfs_verbosity > 0)) { | |
882 | ecryptfs_printk(KERN_DEBUG, "Generated new session key:\n"); | |
883 | ecryptfs_dump_hex(crypt_stat->key, | |
884 | crypt_stat->key_size); | |
885 | } | |
886 | } | |
887 | ||
17398957 MH |
888 | /** |
889 | * ecryptfs_copy_mount_wide_flags_to_inode_flags | |
22e78faf MH |
890 | * @crypt_stat: The inode's cryptographic context |
891 | * @mount_crypt_stat: The mount point's cryptographic context | |
17398957 MH |
892 | * |
893 | * This function propagates the mount-wide flags to individual inode | |
894 | * flags. | |
895 | */ | |
896 | static void ecryptfs_copy_mount_wide_flags_to_inode_flags( | |
897 | struct ecryptfs_crypt_stat *crypt_stat, | |
898 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
899 | { | |
900 | if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) | |
901 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; | |
902 | if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) | |
903 | crypt_stat->flags |= ECRYPTFS_VIEW_AS_ENCRYPTED; | |
904 | } | |
905 | ||
f4aad16a MH |
906 | static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs( |
907 | struct ecryptfs_crypt_stat *crypt_stat, | |
908 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
909 | { | |
910 | struct ecryptfs_global_auth_tok *global_auth_tok; | |
911 | int rc = 0; | |
912 | ||
913 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
914 | list_for_each_entry(global_auth_tok, | |
915 | &mount_crypt_stat->global_auth_tok_list, | |
916 | mount_crypt_stat_list) { | |
917 | rc = ecryptfs_add_keysig(crypt_stat, global_auth_tok->sig); | |
918 | if (rc) { | |
919 | printk(KERN_ERR "Error adding keysig; rc = [%d]\n", rc); | |
920 | mutex_unlock( | |
921 | &mount_crypt_stat->global_auth_tok_list_mutex); | |
922 | goto out; | |
923 | } | |
924 | } | |
925 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
926 | out: | |
927 | return rc; | |
928 | } | |
929 | ||
237fead6 MH |
930 | /** |
931 | * ecryptfs_set_default_crypt_stat_vals | |
22e78faf MH |
932 | * @crypt_stat: The inode's cryptographic context |
933 | * @mount_crypt_stat: The mount point's cryptographic context | |
237fead6 MH |
934 | * |
935 | * Default values in the event that policy does not override them. | |
936 | */ | |
937 | static void ecryptfs_set_default_crypt_stat_vals( | |
938 | struct ecryptfs_crypt_stat *crypt_stat, | |
939 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
940 | { | |
17398957 MH |
941 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
942 | mount_crypt_stat); | |
237fead6 MH |
943 | ecryptfs_set_default_sizes(crypt_stat); |
944 | strcpy(crypt_stat->cipher, ECRYPTFS_DEFAULT_CIPHER); | |
945 | crypt_stat->key_size = ECRYPTFS_DEFAULT_KEY_BYTES; | |
e2bd99ec | 946 | crypt_stat->flags &= ~(ECRYPTFS_KEY_VALID); |
237fead6 MH |
947 | crypt_stat->file_version = ECRYPTFS_FILE_VERSION; |
948 | crypt_stat->mount_crypt_stat = mount_crypt_stat; | |
949 | } | |
950 | ||
951 | /** | |
952 | * ecryptfs_new_file_context | |
22e78faf | 953 | * @ecryptfs_dentry: The eCryptfs dentry |
237fead6 MH |
954 | * |
955 | * If the crypto context for the file has not yet been established, | |
956 | * this is where we do that. Establishing a new crypto context | |
957 | * involves the following decisions: | |
958 | * - What cipher to use? | |
959 | * - What set of authentication tokens to use? | |
960 | * Here we just worry about getting enough information into the | |
961 | * authentication tokens so that we know that they are available. | |
962 | * We associate the available authentication tokens with the new file | |
963 | * via the set of signatures in the crypt_stat struct. Later, when | |
964 | * the headers are actually written out, we may again defer to | |
965 | * userspace to perform the encryption of the session key; for the | |
966 | * foreseeable future, this will be the case with public key packets. | |
967 | * | |
968 | * Returns zero on success; non-zero otherwise | |
969 | */ | |
237fead6 MH |
970 | int ecryptfs_new_file_context(struct dentry *ecryptfs_dentry) |
971 | { | |
237fead6 MH |
972 | struct ecryptfs_crypt_stat *crypt_stat = |
973 | &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; | |
974 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = | |
975 | &ecryptfs_superblock_to_private( | |
976 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
977 | int cipher_name_len; | |
f4aad16a | 978 | int rc = 0; |
237fead6 MH |
979 | |
980 | ecryptfs_set_default_crypt_stat_vals(crypt_stat, mount_crypt_stat); | |
af655dc6 | 981 | crypt_stat->flags |= (ECRYPTFS_ENCRYPTED | ECRYPTFS_KEY_VALID); |
f4aad16a MH |
982 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
983 | mount_crypt_stat); | |
984 | rc = ecryptfs_copy_mount_wide_sigs_to_inode_sigs(crypt_stat, | |
985 | mount_crypt_stat); | |
986 | if (rc) { | |
987 | printk(KERN_ERR "Error attempting to copy mount-wide key sigs " | |
988 | "to the inode key sigs; rc = [%d]\n", rc); | |
989 | goto out; | |
990 | } | |
991 | cipher_name_len = | |
992 | strlen(mount_crypt_stat->global_default_cipher_name); | |
993 | memcpy(crypt_stat->cipher, | |
994 | mount_crypt_stat->global_default_cipher_name, | |
995 | cipher_name_len); | |
996 | crypt_stat->cipher[cipher_name_len] = '\0'; | |
997 | crypt_stat->key_size = | |
998 | mount_crypt_stat->global_default_cipher_key_size; | |
999 | ecryptfs_generate_new_key(crypt_stat); | |
237fead6 MH |
1000 | rc = ecryptfs_init_crypt_ctx(crypt_stat); |
1001 | if (rc) | |
1002 | ecryptfs_printk(KERN_ERR, "Error initializing cryptographic " | |
1003 | "context for cipher [%s]: rc = [%d]\n", | |
1004 | crypt_stat->cipher, rc); | |
f4aad16a | 1005 | out: |
237fead6 MH |
1006 | return rc; |
1007 | } | |
1008 | ||
1009 | /** | |
1010 | * contains_ecryptfs_marker - check for the ecryptfs marker | |
1011 | * @data: The data block in which to check | |
1012 | * | |
1013 | * Returns one if marker found; zero if not found | |
1014 | */ | |
dd2a3b7a | 1015 | static int contains_ecryptfs_marker(char *data) |
237fead6 MH |
1016 | { |
1017 | u32 m_1, m_2; | |
1018 | ||
1019 | memcpy(&m_1, data, 4); | |
1020 | m_1 = be32_to_cpu(m_1); | |
1021 | memcpy(&m_2, (data + 4), 4); | |
1022 | m_2 = be32_to_cpu(m_2); | |
1023 | if ((m_1 ^ MAGIC_ECRYPTFS_MARKER) == m_2) | |
1024 | return 1; | |
1025 | ecryptfs_printk(KERN_DEBUG, "m_1 = [0x%.8x]; m_2 = [0x%.8x]; " | |
1026 | "MAGIC_ECRYPTFS_MARKER = [0x%.8x]\n", m_1, m_2, | |
1027 | MAGIC_ECRYPTFS_MARKER); | |
1028 | ecryptfs_printk(KERN_DEBUG, "(m_1 ^ MAGIC_ECRYPTFS_MARKER) = " | |
1029 | "[0x%.8x]\n", (m_1 ^ MAGIC_ECRYPTFS_MARKER)); | |
1030 | return 0; | |
1031 | } | |
1032 | ||
1033 | struct ecryptfs_flag_map_elem { | |
1034 | u32 file_flag; | |
1035 | u32 local_flag; | |
1036 | }; | |
1037 | ||
1038 | /* Add support for additional flags by adding elements here. */ | |
1039 | static struct ecryptfs_flag_map_elem ecryptfs_flag_map[] = { | |
1040 | {0x00000001, ECRYPTFS_ENABLE_HMAC}, | |
dd2a3b7a MH |
1041 | {0x00000002, ECRYPTFS_ENCRYPTED}, |
1042 | {0x00000004, ECRYPTFS_METADATA_IN_XATTR} | |
237fead6 MH |
1043 | }; |
1044 | ||
1045 | /** | |
1046 | * ecryptfs_process_flags | |
22e78faf | 1047 | * @crypt_stat: The cryptographic context |
237fead6 MH |
1048 | * @page_virt: Source data to be parsed |
1049 | * @bytes_read: Updated with the number of bytes read | |
1050 | * | |
1051 | * Returns zero on success; non-zero if the flag set is invalid | |
1052 | */ | |
1053 | static int ecryptfs_process_flags(struct ecryptfs_crypt_stat *crypt_stat, | |
1054 | char *page_virt, int *bytes_read) | |
1055 | { | |
1056 | int rc = 0; | |
1057 | int i; | |
1058 | u32 flags; | |
1059 | ||
1060 | memcpy(&flags, page_virt, 4); | |
1061 | flags = be32_to_cpu(flags); | |
1062 | for (i = 0; i < ((sizeof(ecryptfs_flag_map) | |
1063 | / sizeof(struct ecryptfs_flag_map_elem))); i++) | |
1064 | if (flags & ecryptfs_flag_map[i].file_flag) { | |
e2bd99ec | 1065 | crypt_stat->flags |= ecryptfs_flag_map[i].local_flag; |
237fead6 | 1066 | } else |
e2bd99ec | 1067 | crypt_stat->flags &= ~(ecryptfs_flag_map[i].local_flag); |
237fead6 MH |
1068 | /* Version is in top 8 bits of the 32-bit flag vector */ |
1069 | crypt_stat->file_version = ((flags >> 24) & 0xFF); | |
1070 | (*bytes_read) = 4; | |
1071 | return rc; | |
1072 | } | |
1073 | ||
1074 | /** | |
1075 | * write_ecryptfs_marker | |
1076 | * @page_virt: The pointer to in a page to begin writing the marker | |
1077 | * @written: Number of bytes written | |
1078 | * | |
1079 | * Marker = 0x3c81b7f5 | |
1080 | */ | |
1081 | static void write_ecryptfs_marker(char *page_virt, size_t *written) | |
1082 | { | |
1083 | u32 m_1, m_2; | |
1084 | ||
1085 | get_random_bytes(&m_1, (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); | |
1086 | m_2 = (m_1 ^ MAGIC_ECRYPTFS_MARKER); | |
1087 | m_1 = cpu_to_be32(m_1); | |
1088 | memcpy(page_virt, &m_1, (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); | |
1089 | m_2 = cpu_to_be32(m_2); | |
1090 | memcpy(page_virt + (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2), &m_2, | |
1091 | (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); | |
1092 | (*written) = MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; | |
1093 | } | |
1094 | ||
1095 | static void | |
1096 | write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat, | |
1097 | size_t *written) | |
1098 | { | |
1099 | u32 flags = 0; | |
1100 | int i; | |
1101 | ||
1102 | for (i = 0; i < ((sizeof(ecryptfs_flag_map) | |
1103 | / sizeof(struct ecryptfs_flag_map_elem))); i++) | |
e2bd99ec | 1104 | if (crypt_stat->flags & ecryptfs_flag_map[i].local_flag) |
237fead6 MH |
1105 | flags |= ecryptfs_flag_map[i].file_flag; |
1106 | /* Version is in top 8 bits of the 32-bit flag vector */ | |
1107 | flags |= ((((u8)crypt_stat->file_version) << 24) & 0xFF000000); | |
1108 | flags = cpu_to_be32(flags); | |
1109 | memcpy(page_virt, &flags, 4); | |
1110 | (*written) = 4; | |
1111 | } | |
1112 | ||
1113 | struct ecryptfs_cipher_code_str_map_elem { | |
1114 | char cipher_str[16]; | |
1115 | u16 cipher_code; | |
1116 | }; | |
1117 | ||
1118 | /* Add support for additional ciphers by adding elements here. The | |
1119 | * cipher_code is whatever OpenPGP applicatoins use to identify the | |
1120 | * ciphers. List in order of probability. */ | |
1121 | static struct ecryptfs_cipher_code_str_map_elem | |
1122 | ecryptfs_cipher_code_str_map[] = { | |
1123 | {"aes",RFC2440_CIPHER_AES_128 }, | |
1124 | {"blowfish", RFC2440_CIPHER_BLOWFISH}, | |
1125 | {"des3_ede", RFC2440_CIPHER_DES3_EDE}, | |
1126 | {"cast5", RFC2440_CIPHER_CAST_5}, | |
1127 | {"twofish", RFC2440_CIPHER_TWOFISH}, | |
1128 | {"cast6", RFC2440_CIPHER_CAST_6}, | |
1129 | {"aes", RFC2440_CIPHER_AES_192}, | |
1130 | {"aes", RFC2440_CIPHER_AES_256} | |
1131 | }; | |
1132 | ||
1133 | /** | |
1134 | * ecryptfs_code_for_cipher_string | |
22e78faf | 1135 | * @crypt_stat: The cryptographic context |
237fead6 MH |
1136 | * |
1137 | * Returns zero on no match, or the cipher code on match | |
1138 | */ | |
1139 | u16 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat) | |
1140 | { | |
1141 | int i; | |
1142 | u16 code = 0; | |
1143 | struct ecryptfs_cipher_code_str_map_elem *map = | |
1144 | ecryptfs_cipher_code_str_map; | |
1145 | ||
1146 | if (strcmp(crypt_stat->cipher, "aes") == 0) { | |
1147 | switch (crypt_stat->key_size) { | |
1148 | case 16: | |
1149 | code = RFC2440_CIPHER_AES_128; | |
1150 | break; | |
1151 | case 24: | |
1152 | code = RFC2440_CIPHER_AES_192; | |
1153 | break; | |
1154 | case 32: | |
1155 | code = RFC2440_CIPHER_AES_256; | |
1156 | } | |
1157 | } else { | |
1158 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++) | |
1159 | if (strcmp(crypt_stat->cipher, map[i].cipher_str) == 0){ | |
1160 | code = map[i].cipher_code; | |
1161 | break; | |
1162 | } | |
1163 | } | |
1164 | return code; | |
1165 | } | |
1166 | ||
1167 | /** | |
1168 | * ecryptfs_cipher_code_to_string | |
1169 | * @str: Destination to write out the cipher name | |
1170 | * @cipher_code: The code to convert to cipher name string | |
1171 | * | |
1172 | * Returns zero on success | |
1173 | */ | |
1174 | int ecryptfs_cipher_code_to_string(char *str, u16 cipher_code) | |
1175 | { | |
1176 | int rc = 0; | |
1177 | int i; | |
1178 | ||
1179 | str[0] = '\0'; | |
1180 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++) | |
1181 | if (cipher_code == ecryptfs_cipher_code_str_map[i].cipher_code) | |
1182 | strcpy(str, ecryptfs_cipher_code_str_map[i].cipher_str); | |
1183 | if (str[0] == '\0') { | |
1184 | ecryptfs_printk(KERN_WARNING, "Cipher code not recognized: " | |
1185 | "[%d]\n", cipher_code); | |
1186 | rc = -EINVAL; | |
1187 | } | |
1188 | return rc; | |
1189 | } | |
1190 | ||
d7cdc5fe MH |
1191 | int ecryptfs_read_and_validate_header_region(char *data, |
1192 | struct inode *ecryptfs_inode) | |
dd2a3b7a | 1193 | { |
d7cdc5fe MH |
1194 | struct ecryptfs_crypt_stat *crypt_stat = |
1195 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); | |
dd2a3b7a MH |
1196 | int rc; |
1197 | ||
d7cdc5fe MH |
1198 | rc = ecryptfs_read_lower(data, 0, crypt_stat->extent_size, |
1199 | ecryptfs_inode); | |
1200 | if (rc) { | |
1201 | printk(KERN_ERR "%s: Error reading header region; rc = [%d]\n", | |
1202 | __FUNCTION__, rc); | |
dd2a3b7a | 1203 | goto out; |
d7cdc5fe MH |
1204 | } |
1205 | if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) { | |
dd2a3b7a | 1206 | rc = -EINVAL; |
d7cdc5fe MH |
1207 | ecryptfs_printk(KERN_DEBUG, "Valid marker not found\n"); |
1208 | } | |
dd2a3b7a MH |
1209 | out: |
1210 | return rc; | |
1211 | } | |
1212 | ||
e77a56dd MH |
1213 | void |
1214 | ecryptfs_write_header_metadata(char *virt, | |
1215 | struct ecryptfs_crypt_stat *crypt_stat, | |
1216 | size_t *written) | |
237fead6 MH |
1217 | { |
1218 | u32 header_extent_size; | |
1219 | u16 num_header_extents_at_front; | |
1220 | ||
45eaab79 | 1221 | header_extent_size = (u32)crypt_stat->extent_size; |
237fead6 MH |
1222 | num_header_extents_at_front = |
1223 | (u16)crypt_stat->num_header_extents_at_front; | |
1224 | header_extent_size = cpu_to_be32(header_extent_size); | |
1225 | memcpy(virt, &header_extent_size, 4); | |
1226 | virt += 4; | |
1227 | num_header_extents_at_front = cpu_to_be16(num_header_extents_at_front); | |
1228 | memcpy(virt, &num_header_extents_at_front, 2); | |
1229 | (*written) = 6; | |
1230 | } | |
1231 | ||
1232 | struct kmem_cache *ecryptfs_header_cache_0; | |
1233 | struct kmem_cache *ecryptfs_header_cache_1; | |
1234 | struct kmem_cache *ecryptfs_header_cache_2; | |
1235 | ||
1236 | /** | |
1237 | * ecryptfs_write_headers_virt | |
22e78faf MH |
1238 | * @page_virt: The virtual address to write the headers to |
1239 | * @size: Set to the number of bytes written by this function | |
1240 | * @crypt_stat: The cryptographic context | |
1241 | * @ecryptfs_dentry: The eCryptfs dentry | |
237fead6 MH |
1242 | * |
1243 | * Format version: 1 | |
1244 | * | |
1245 | * Header Extent: | |
1246 | * Octets 0-7: Unencrypted file size (big-endian) | |
1247 | * Octets 8-15: eCryptfs special marker | |
1248 | * Octets 16-19: Flags | |
1249 | * Octet 16: File format version number (between 0 and 255) | |
1250 | * Octets 17-18: Reserved | |
1251 | * Octet 19: Bit 1 (lsb): Reserved | |
1252 | * Bit 2: Encrypted? | |
1253 | * Bits 3-8: Reserved | |
1254 | * Octets 20-23: Header extent size (big-endian) | |
1255 | * Octets 24-25: Number of header extents at front of file | |
1256 | * (big-endian) | |
1257 | * Octet 26: Begin RFC 2440 authentication token packet set | |
1258 | * Data Extent 0: | |
1259 | * Lower data (CBC encrypted) | |
1260 | * Data Extent 1: | |
1261 | * Lower data (CBC encrypted) | |
1262 | * ... | |
1263 | * | |
1264 | * Returns zero on success | |
1265 | */ | |
dd2a3b7a MH |
1266 | static int ecryptfs_write_headers_virt(char *page_virt, size_t *size, |
1267 | struct ecryptfs_crypt_stat *crypt_stat, | |
1268 | struct dentry *ecryptfs_dentry) | |
237fead6 MH |
1269 | { |
1270 | int rc; | |
1271 | size_t written; | |
1272 | size_t offset; | |
1273 | ||
1274 | offset = ECRYPTFS_FILE_SIZE_BYTES; | |
1275 | write_ecryptfs_marker((page_virt + offset), &written); | |
1276 | offset += written; | |
1277 | write_ecryptfs_flags((page_virt + offset), crypt_stat, &written); | |
1278 | offset += written; | |
e77a56dd MH |
1279 | ecryptfs_write_header_metadata((page_virt + offset), crypt_stat, |
1280 | &written); | |
237fead6 MH |
1281 | offset += written; |
1282 | rc = ecryptfs_generate_key_packet_set((page_virt + offset), crypt_stat, | |
1283 | ecryptfs_dentry, &written, | |
1284 | PAGE_CACHE_SIZE - offset); | |
1285 | if (rc) | |
1286 | ecryptfs_printk(KERN_WARNING, "Error generating key packet " | |
1287 | "set; rc = [%d]\n", rc); | |
dd2a3b7a MH |
1288 | if (size) { |
1289 | offset += written; | |
1290 | *size = offset; | |
1291 | } | |
1292 | return rc; | |
1293 | } | |
1294 | ||
22e78faf MH |
1295 | static int |
1296 | ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat, | |
d7cdc5fe MH |
1297 | struct dentry *ecryptfs_dentry, |
1298 | char *page_virt) | |
dd2a3b7a | 1299 | { |
dd2a3b7a MH |
1300 | int current_header_page; |
1301 | int header_pages; | |
d7cdc5fe | 1302 | int rc; |
dd2a3b7a | 1303 | |
d7cdc5fe MH |
1304 | rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, page_virt, |
1305 | 0, PAGE_CACHE_SIZE); | |
1306 | if (rc) { | |
1307 | printk(KERN_ERR "%s: Error attempting to write header " | |
1308 | "information to lower file; rc = [%d]\n", __FUNCTION__, | |
1309 | rc); | |
70456600 MH |
1310 | goto out; |
1311 | } | |
45eaab79 | 1312 | header_pages = ((crypt_stat->extent_size |
dd2a3b7a MH |
1313 | * crypt_stat->num_header_extents_at_front) |
1314 | / PAGE_CACHE_SIZE); | |
1315 | memset(page_virt, 0, PAGE_CACHE_SIZE); | |
1316 | current_header_page = 1; | |
1317 | while (current_header_page < header_pages) { | |
d7cdc5fe MH |
1318 | loff_t offset; |
1319 | ||
d6a13c17 | 1320 | offset = (((loff_t)current_header_page) << PAGE_CACHE_SHIFT); |
d7cdc5fe MH |
1321 | if ((rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, |
1322 | page_virt, offset, | |
1323 | PAGE_CACHE_SIZE))) { | |
1324 | printk(KERN_ERR "%s: Error attempting to write header " | |
1325 | "information to lower file; rc = [%d]\n", | |
1326 | __FUNCTION__, rc); | |
70456600 MH |
1327 | goto out; |
1328 | } | |
dd2a3b7a MH |
1329 | current_header_page++; |
1330 | } | |
70456600 MH |
1331 | out: |
1332 | return rc; | |
dd2a3b7a MH |
1333 | } |
1334 | ||
22e78faf MH |
1335 | static int |
1336 | ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, | |
1337 | struct ecryptfs_crypt_stat *crypt_stat, | |
1338 | char *page_virt, size_t size) | |
dd2a3b7a MH |
1339 | { |
1340 | int rc; | |
1341 | ||
1342 | rc = ecryptfs_setxattr(ecryptfs_dentry, ECRYPTFS_XATTR_NAME, page_virt, | |
1343 | size, 0); | |
237fead6 MH |
1344 | return rc; |
1345 | } | |
1346 | ||
1347 | /** | |
dd2a3b7a | 1348 | * ecryptfs_write_metadata |
22e78faf | 1349 | * @ecryptfs_dentry: The eCryptfs dentry |
237fead6 MH |
1350 | * |
1351 | * Write the file headers out. This will likely involve a userspace | |
1352 | * callout, in which the session key is encrypted with one or more | |
1353 | * public keys and/or the passphrase necessary to do the encryption is | |
1354 | * retrieved via a prompt. Exactly what happens at this point should | |
1355 | * be policy-dependent. | |
1356 | * | |
d7cdc5fe MH |
1357 | * TODO: Support header information spanning multiple pages |
1358 | * | |
237fead6 MH |
1359 | * Returns zero on success; non-zero on error |
1360 | */ | |
d7cdc5fe | 1361 | int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry) |
237fead6 | 1362 | { |
d7cdc5fe MH |
1363 | struct ecryptfs_crypt_stat *crypt_stat = |
1364 | &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; | |
237fead6 | 1365 | char *page_virt; |
d7cdc5fe | 1366 | size_t size = 0; |
237fead6 MH |
1367 | int rc = 0; |
1368 | ||
e2bd99ec MH |
1369 | if (likely(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
1370 | if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { | |
d7cdc5fe | 1371 | printk(KERN_ERR "Key is invalid; bailing out\n"); |
237fead6 MH |
1372 | rc = -EINVAL; |
1373 | goto out; | |
1374 | } | |
1375 | } else { | |
1376 | rc = -EINVAL; | |
1377 | ecryptfs_printk(KERN_WARNING, | |
1378 | "Called with crypt_stat->encrypted == 0\n"); | |
1379 | goto out; | |
1380 | } | |
1381 | /* Released in this function */ | |
c3762229 | 1382 | page_virt = kmem_cache_zalloc(ecryptfs_header_cache_0, GFP_USER); |
237fead6 MH |
1383 | if (!page_virt) { |
1384 | ecryptfs_printk(KERN_ERR, "Out of memory\n"); | |
1385 | rc = -ENOMEM; | |
1386 | goto out; | |
1387 | } | |
dd2a3b7a MH |
1388 | rc = ecryptfs_write_headers_virt(page_virt, &size, crypt_stat, |
1389 | ecryptfs_dentry); | |
237fead6 MH |
1390 | if (unlikely(rc)) { |
1391 | ecryptfs_printk(KERN_ERR, "Error whilst writing headers\n"); | |
1392 | memset(page_virt, 0, PAGE_CACHE_SIZE); | |
1393 | goto out_free; | |
1394 | } | |
dd2a3b7a MH |
1395 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
1396 | rc = ecryptfs_write_metadata_to_xattr(ecryptfs_dentry, | |
1397 | crypt_stat, page_virt, | |
1398 | size); | |
1399 | else | |
d7cdc5fe MH |
1400 | rc = ecryptfs_write_metadata_to_contents(crypt_stat, |
1401 | ecryptfs_dentry, | |
dd2a3b7a MH |
1402 | page_virt); |
1403 | if (rc) { | |
1404 | printk(KERN_ERR "Error writing metadata out to lower file; " | |
1405 | "rc = [%d]\n", rc); | |
1406 | goto out_free; | |
237fead6 | 1407 | } |
237fead6 MH |
1408 | out_free: |
1409 | kmem_cache_free(ecryptfs_header_cache_0, page_virt); | |
1410 | out: | |
1411 | return rc; | |
1412 | } | |
1413 | ||
dd2a3b7a MH |
1414 | #define ECRYPTFS_DONT_VALIDATE_HEADER_SIZE 0 |
1415 | #define ECRYPTFS_VALIDATE_HEADER_SIZE 1 | |
237fead6 | 1416 | static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat, |
dd2a3b7a MH |
1417 | char *virt, int *bytes_read, |
1418 | int validate_header_size) | |
237fead6 MH |
1419 | { |
1420 | int rc = 0; | |
1421 | u32 header_extent_size; | |
1422 | u16 num_header_extents_at_front; | |
1423 | ||
ecbdc936 | 1424 | memcpy(&header_extent_size, virt, sizeof(u32)); |
237fead6 | 1425 | header_extent_size = be32_to_cpu(header_extent_size); |
ecbdc936 MH |
1426 | virt += sizeof(u32); |
1427 | memcpy(&num_header_extents_at_front, virt, sizeof(u16)); | |
237fead6 | 1428 | num_header_extents_at_front = be16_to_cpu(num_header_extents_at_front); |
237fead6 MH |
1429 | crypt_stat->num_header_extents_at_front = |
1430 | (int)num_header_extents_at_front; | |
45eaab79 | 1431 | (*bytes_read) = (sizeof(u32) + sizeof(u16)); |
dd2a3b7a | 1432 | if ((validate_header_size == ECRYPTFS_VALIDATE_HEADER_SIZE) |
45eaab79 | 1433 | && ((crypt_stat->extent_size |
dd2a3b7a MH |
1434 | * crypt_stat->num_header_extents_at_front) |
1435 | < ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)) { | |
237fead6 | 1436 | rc = -EINVAL; |
45eaab79 MH |
1437 | printk(KERN_WARNING "Invalid number of header extents: [%zd]\n", |
1438 | crypt_stat->num_header_extents_at_front); | |
237fead6 MH |
1439 | } |
1440 | return rc; | |
1441 | } | |
1442 | ||
1443 | /** | |
1444 | * set_default_header_data | |
22e78faf | 1445 | * @crypt_stat: The cryptographic context |
237fead6 MH |
1446 | * |
1447 | * For version 0 file format; this function is only for backwards | |
1448 | * compatibility for files created with the prior versions of | |
1449 | * eCryptfs. | |
1450 | */ | |
1451 | static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat) | |
1452 | { | |
45eaab79 | 1453 | crypt_stat->num_header_extents_at_front = 2; |
237fead6 MH |
1454 | } |
1455 | ||
1456 | /** | |
1457 | * ecryptfs_read_headers_virt | |
22e78faf MH |
1458 | * @page_virt: The virtual address into which to read the headers |
1459 | * @crypt_stat: The cryptographic context | |
1460 | * @ecryptfs_dentry: The eCryptfs dentry | |
1461 | * @validate_header_size: Whether to validate the header size while reading | |
237fead6 MH |
1462 | * |
1463 | * Read/parse the header data. The header format is detailed in the | |
1464 | * comment block for the ecryptfs_write_headers_virt() function. | |
1465 | * | |
1466 | * Returns zero on success | |
1467 | */ | |
1468 | static int ecryptfs_read_headers_virt(char *page_virt, | |
1469 | struct ecryptfs_crypt_stat *crypt_stat, | |
dd2a3b7a MH |
1470 | struct dentry *ecryptfs_dentry, |
1471 | int validate_header_size) | |
237fead6 MH |
1472 | { |
1473 | int rc = 0; | |
1474 | int offset; | |
1475 | int bytes_read; | |
1476 | ||
1477 | ecryptfs_set_default_sizes(crypt_stat); | |
1478 | crypt_stat->mount_crypt_stat = &ecryptfs_superblock_to_private( | |
1479 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
1480 | offset = ECRYPTFS_FILE_SIZE_BYTES; | |
1481 | rc = contains_ecryptfs_marker(page_virt + offset); | |
1482 | if (rc == 0) { | |
1483 | rc = -EINVAL; | |
1484 | goto out; | |
1485 | } | |
1486 | offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; | |
1487 | rc = ecryptfs_process_flags(crypt_stat, (page_virt + offset), | |
1488 | &bytes_read); | |
1489 | if (rc) { | |
1490 | ecryptfs_printk(KERN_WARNING, "Error processing flags\n"); | |
1491 | goto out; | |
1492 | } | |
1493 | if (crypt_stat->file_version > ECRYPTFS_SUPPORTED_FILE_VERSION) { | |
1494 | ecryptfs_printk(KERN_WARNING, "File version is [%d]; only " | |
1495 | "file version [%d] is supported by this " | |
1496 | "version of eCryptfs\n", | |
1497 | crypt_stat->file_version, | |
1498 | ECRYPTFS_SUPPORTED_FILE_VERSION); | |
1499 | rc = -EINVAL; | |
1500 | goto out; | |
1501 | } | |
1502 | offset += bytes_read; | |
1503 | if (crypt_stat->file_version >= 1) { | |
1504 | rc = parse_header_metadata(crypt_stat, (page_virt + offset), | |
dd2a3b7a | 1505 | &bytes_read, validate_header_size); |
237fead6 MH |
1506 | if (rc) { |
1507 | ecryptfs_printk(KERN_WARNING, "Error reading header " | |
1508 | "metadata; rc = [%d]\n", rc); | |
1509 | } | |
1510 | offset += bytes_read; | |
1511 | } else | |
1512 | set_default_header_data(crypt_stat); | |
1513 | rc = ecryptfs_parse_packet_set(crypt_stat, (page_virt + offset), | |
1514 | ecryptfs_dentry); | |
1515 | out: | |
1516 | return rc; | |
1517 | } | |
1518 | ||
1519 | /** | |
dd2a3b7a | 1520 | * ecryptfs_read_xattr_region |
22e78faf | 1521 | * @page_virt: The vitual address into which to read the xattr data |
2ed92554 | 1522 | * @ecryptfs_inode: The eCryptfs inode |
dd2a3b7a MH |
1523 | * |
1524 | * Attempts to read the crypto metadata from the extended attribute | |
1525 | * region of the lower file. | |
22e78faf MH |
1526 | * |
1527 | * Returns zero on success; non-zero on error | |
dd2a3b7a | 1528 | */ |
d7cdc5fe | 1529 | int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode) |
dd2a3b7a | 1530 | { |
d7cdc5fe MH |
1531 | struct dentry *lower_dentry = |
1532 | ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry; | |
dd2a3b7a MH |
1533 | ssize_t size; |
1534 | int rc = 0; | |
1535 | ||
d7cdc5fe MH |
1536 | size = ecryptfs_getxattr_lower(lower_dentry, ECRYPTFS_XATTR_NAME, |
1537 | page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE); | |
dd2a3b7a | 1538 | if (size < 0) { |
d7cdc5fe | 1539 | printk(KERN_ERR "Error attempting to read the [%s] " |
dd2a3b7a MH |
1540 | "xattr from the lower file; return value = [%zd]\n", |
1541 | ECRYPTFS_XATTR_NAME, size); | |
1542 | rc = -EINVAL; | |
1543 | goto out; | |
1544 | } | |
1545 | out: | |
1546 | return rc; | |
1547 | } | |
1548 | ||
1549 | int ecryptfs_read_and_validate_xattr_region(char *page_virt, | |
1550 | struct dentry *ecryptfs_dentry) | |
1551 | { | |
1552 | int rc; | |
1553 | ||
d7cdc5fe | 1554 | rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry->d_inode); |
dd2a3b7a MH |
1555 | if (rc) |
1556 | goto out; | |
1557 | if (!contains_ecryptfs_marker(page_virt + ECRYPTFS_FILE_SIZE_BYTES)) { | |
1558 | printk(KERN_WARNING "Valid data found in [%s] xattr, but " | |
1559 | "the marker is invalid\n", ECRYPTFS_XATTR_NAME); | |
1560 | rc = -EINVAL; | |
1561 | } | |
1562 | out: | |
1563 | return rc; | |
1564 | } | |
1565 | ||
1566 | /** | |
1567 | * ecryptfs_read_metadata | |
1568 | * | |
1569 | * Common entry point for reading file metadata. From here, we could | |
1570 | * retrieve the header information from the header region of the file, | |
1571 | * the xattr region of the file, or some other repostory that is | |
1572 | * stored separately from the file itself. The current implementation | |
1573 | * supports retrieving the metadata information from the file contents | |
1574 | * and from the xattr region. | |
237fead6 MH |
1575 | * |
1576 | * Returns zero if valid headers found and parsed; non-zero otherwise | |
1577 | */ | |
d7cdc5fe | 1578 | int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry) |
237fead6 MH |
1579 | { |
1580 | int rc = 0; | |
1581 | char *page_virt = NULL; | |
d7cdc5fe | 1582 | struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode; |
237fead6 | 1583 | struct ecryptfs_crypt_stat *crypt_stat = |
d7cdc5fe | 1584 | &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
e77a56dd MH |
1585 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
1586 | &ecryptfs_superblock_to_private( | |
1587 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
237fead6 | 1588 | |
e77a56dd MH |
1589 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
1590 | mount_crypt_stat); | |
237fead6 | 1591 | /* Read the first page from the underlying file */ |
f7267c0c | 1592 | page_virt = kmem_cache_alloc(ecryptfs_header_cache_1, GFP_USER); |
237fead6 MH |
1593 | if (!page_virt) { |
1594 | rc = -ENOMEM; | |
d7cdc5fe MH |
1595 | printk(KERN_ERR "%s: Unable to allocate page_virt\n", |
1596 | __FUNCTION__); | |
237fead6 MH |
1597 | goto out; |
1598 | } | |
d7cdc5fe MH |
1599 | rc = ecryptfs_read_lower(page_virt, 0, crypt_stat->extent_size, |
1600 | ecryptfs_inode); | |
1601 | if (!rc) | |
1602 | rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, | |
1603 | ecryptfs_dentry, | |
1604 | ECRYPTFS_VALIDATE_HEADER_SIZE); | |
237fead6 | 1605 | if (rc) { |
d7cdc5fe | 1606 | rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode); |
dd2a3b7a MH |
1607 | if (rc) { |
1608 | printk(KERN_DEBUG "Valid eCryptfs headers not found in " | |
1609 | "file header region or xattr region\n"); | |
1610 | rc = -EINVAL; | |
1611 | goto out; | |
1612 | } | |
1613 | rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, | |
1614 | ecryptfs_dentry, | |
1615 | ECRYPTFS_DONT_VALIDATE_HEADER_SIZE); | |
1616 | if (rc) { | |
1617 | printk(KERN_DEBUG "Valid eCryptfs headers not found in " | |
1618 | "file xattr region either\n"); | |
1619 | rc = -EINVAL; | |
1620 | } | |
1621 | if (crypt_stat->mount_crypt_stat->flags | |
1622 | & ECRYPTFS_XATTR_METADATA_ENABLED) { | |
1623 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; | |
1624 | } else { | |
1625 | printk(KERN_WARNING "Attempt to access file with " | |
1626 | "crypto metadata only in the extended attribute " | |
1627 | "region, but eCryptfs was mounted without " | |
1628 | "xattr support enabled. eCryptfs will not treat " | |
1629 | "this like an encrypted file.\n"); | |
1630 | rc = -EINVAL; | |
1631 | } | |
237fead6 MH |
1632 | } |
1633 | out: | |
1634 | if (page_virt) { | |
1635 | memset(page_virt, 0, PAGE_CACHE_SIZE); | |
1636 | kmem_cache_free(ecryptfs_header_cache_1, page_virt); | |
1637 | } | |
1638 | return rc; | |
1639 | } | |
1640 | ||
1641 | /** | |
1642 | * ecryptfs_encode_filename - converts a plaintext file name to cipher text | |
1643 | * @crypt_stat: The crypt_stat struct associated with the file anem to encode | |
1644 | * @name: The plaintext name | |
1645 | * @length: The length of the plaintext | |
1646 | * @encoded_name: The encypted name | |
1647 | * | |
1648 | * Encrypts and encodes a filename into something that constitutes a | |
1649 | * valid filename for a filesystem, with printable characters. | |
1650 | * | |
1651 | * We assume that we have a properly initialized crypto context, | |
1652 | * pointed to by crypt_stat->tfm. | |
1653 | * | |
1654 | * TODO: Implement filename decoding and decryption here, in place of | |
1655 | * memcpy. We are keeping the framework around for now to (1) | |
1656 | * facilitate testing of the components needed to implement filename | |
1657 | * encryption and (2) to provide a code base from which other | |
1658 | * developers in the community can easily implement this feature. | |
1659 | * | |
1660 | * Returns the length of encoded filename; negative if error | |
1661 | */ | |
1662 | int | |
1663 | ecryptfs_encode_filename(struct ecryptfs_crypt_stat *crypt_stat, | |
1664 | const char *name, int length, char **encoded_name) | |
1665 | { | |
1666 | int error = 0; | |
1667 | ||
1668 | (*encoded_name) = kmalloc(length + 2, GFP_KERNEL); | |
1669 | if (!(*encoded_name)) { | |
1670 | error = -ENOMEM; | |
1671 | goto out; | |
1672 | } | |
1673 | /* TODO: Filename encryption is a scheduled feature for a | |
1674 | * future version of eCryptfs. This function is here only for | |
1675 | * the purpose of providing a framework for other developers | |
1676 | * to easily implement filename encryption. Hint: Replace this | |
1677 | * memcpy() with a call to encrypt and encode the | |
1678 | * filename, the set the length accordingly. */ | |
1679 | memcpy((void *)(*encoded_name), (void *)name, length); | |
1680 | (*encoded_name)[length] = '\0'; | |
1681 | error = length + 1; | |
1682 | out: | |
1683 | return error; | |
1684 | } | |
1685 | ||
1686 | /** | |
1687 | * ecryptfs_decode_filename - converts the cipher text name to plaintext | |
1688 | * @crypt_stat: The crypt_stat struct associated with the file | |
1689 | * @name: The filename in cipher text | |
1690 | * @length: The length of the cipher text name | |
1691 | * @decrypted_name: The plaintext name | |
1692 | * | |
1693 | * Decodes and decrypts the filename. | |
1694 | * | |
1695 | * We assume that we have a properly initialized crypto context, | |
1696 | * pointed to by crypt_stat->tfm. | |
1697 | * | |
1698 | * TODO: Implement filename decoding and decryption here, in place of | |
1699 | * memcpy. We are keeping the framework around for now to (1) | |
1700 | * facilitate testing of the components needed to implement filename | |
1701 | * encryption and (2) to provide a code base from which other | |
1702 | * developers in the community can easily implement this feature. | |
1703 | * | |
1704 | * Returns the length of decoded filename; negative if error | |
1705 | */ | |
1706 | int | |
1707 | ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat, | |
1708 | const char *name, int length, char **decrypted_name) | |
1709 | { | |
1710 | int error = 0; | |
1711 | ||
1712 | (*decrypted_name) = kmalloc(length + 2, GFP_KERNEL); | |
1713 | if (!(*decrypted_name)) { | |
1714 | error = -ENOMEM; | |
1715 | goto out; | |
1716 | } | |
1717 | /* TODO: Filename encryption is a scheduled feature for a | |
1718 | * future version of eCryptfs. This function is here only for | |
1719 | * the purpose of providing a framework for other developers | |
1720 | * to easily implement filename encryption. Hint: Replace this | |
1721 | * memcpy() with a call to decode and decrypt the | |
1722 | * filename, the set the length accordingly. */ | |
1723 | memcpy((void *)(*decrypted_name), (void *)name, length); | |
1724 | (*decrypted_name)[length + 1] = '\0'; /* Only for convenience | |
1725 | * in printing out the | |
1726 | * string in debug | |
1727 | * messages */ | |
1728 | error = length; | |
1729 | out: | |
1730 | return error; | |
1731 | } | |
1732 | ||
1733 | /** | |
f4aad16a | 1734 | * ecryptfs_process_key_cipher - Perform key cipher initialization. |
237fead6 | 1735 | * @key_tfm: Crypto context for key material, set by this function |
e5d9cbde MH |
1736 | * @cipher_name: Name of the cipher |
1737 | * @key_size: Size of the key in bytes | |
237fead6 MH |
1738 | * |
1739 | * Returns zero on success. Any crypto_tfm structs allocated here | |
1740 | * should be released by other functions, such as on a superblock put | |
1741 | * event, regardless of whether this function succeeds for fails. | |
1742 | */ | |
cd9d67df | 1743 | static int |
f4aad16a MH |
1744 | ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm, |
1745 | char *cipher_name, size_t *key_size) | |
237fead6 MH |
1746 | { |
1747 | char dummy_key[ECRYPTFS_MAX_KEY_BYTES]; | |
8bba066f | 1748 | char *full_alg_name; |
237fead6 MH |
1749 | int rc; |
1750 | ||
e5d9cbde MH |
1751 | *key_tfm = NULL; |
1752 | if (*key_size > ECRYPTFS_MAX_KEY_BYTES) { | |
237fead6 MH |
1753 | rc = -EINVAL; |
1754 | printk(KERN_ERR "Requested key size is [%Zd] bytes; maximum " | |
e5d9cbde | 1755 | "allowable is [%d]\n", *key_size, ECRYPTFS_MAX_KEY_BYTES); |
237fead6 MH |
1756 | goto out; |
1757 | } | |
8bba066f MH |
1758 | rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, cipher_name, |
1759 | "ecb"); | |
1760 | if (rc) | |
1761 | goto out; | |
1762 | *key_tfm = crypto_alloc_blkcipher(full_alg_name, 0, CRYPTO_ALG_ASYNC); | |
1763 | kfree(full_alg_name); | |
1764 | if (IS_ERR(*key_tfm)) { | |
1765 | rc = PTR_ERR(*key_tfm); | |
237fead6 | 1766 | printk(KERN_ERR "Unable to allocate crypto cipher with name " |
8bba066f | 1767 | "[%s]; rc = [%d]\n", cipher_name, rc); |
237fead6 MH |
1768 | goto out; |
1769 | } | |
8bba066f MH |
1770 | crypto_blkcipher_set_flags(*key_tfm, CRYPTO_TFM_REQ_WEAK_KEY); |
1771 | if (*key_size == 0) { | |
1772 | struct blkcipher_alg *alg = crypto_blkcipher_alg(*key_tfm); | |
1773 | ||
1774 | *key_size = alg->max_keysize; | |
1775 | } | |
e5d9cbde | 1776 | get_random_bytes(dummy_key, *key_size); |
8bba066f | 1777 | rc = crypto_blkcipher_setkey(*key_tfm, dummy_key, *key_size); |
237fead6 MH |
1778 | if (rc) { |
1779 | printk(KERN_ERR "Error attempting to set key of size [%Zd] for " | |
e5d9cbde | 1780 | "cipher [%s]; rc = [%d]\n", *key_size, cipher_name, rc); |
237fead6 MH |
1781 | rc = -EINVAL; |
1782 | goto out; | |
1783 | } | |
1784 | out: | |
1785 | return rc; | |
1786 | } | |
f4aad16a MH |
1787 | |
1788 | struct kmem_cache *ecryptfs_key_tfm_cache; | |
1789 | struct list_head key_tfm_list; | |
1790 | struct mutex key_tfm_list_mutex; | |
1791 | ||
1792 | int ecryptfs_init_crypto(void) | |
1793 | { | |
1794 | mutex_init(&key_tfm_list_mutex); | |
1795 | INIT_LIST_HEAD(&key_tfm_list); | |
1796 | return 0; | |
1797 | } | |
1798 | ||
fcd12835 | 1799 | int ecryptfs_destroy_crypto(void) |
f4aad16a MH |
1800 | { |
1801 | struct ecryptfs_key_tfm *key_tfm, *key_tfm_tmp; | |
1802 | ||
1803 | mutex_lock(&key_tfm_list_mutex); | |
1804 | list_for_each_entry_safe(key_tfm, key_tfm_tmp, &key_tfm_list, | |
1805 | key_tfm_list) { | |
1806 | list_del(&key_tfm->key_tfm_list); | |
1807 | if (key_tfm->key_tfm) | |
1808 | crypto_free_blkcipher(key_tfm->key_tfm); | |
1809 | kmem_cache_free(ecryptfs_key_tfm_cache, key_tfm); | |
1810 | } | |
1811 | mutex_unlock(&key_tfm_list_mutex); | |
1812 | return 0; | |
1813 | } | |
1814 | ||
1815 | int | |
1816 | ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name, | |
1817 | size_t key_size) | |
1818 | { | |
1819 | struct ecryptfs_key_tfm *tmp_tfm; | |
1820 | int rc = 0; | |
1821 | ||
1822 | tmp_tfm = kmem_cache_alloc(ecryptfs_key_tfm_cache, GFP_KERNEL); | |
1823 | if (key_tfm != NULL) | |
1824 | (*key_tfm) = tmp_tfm; | |
1825 | if (!tmp_tfm) { | |
1826 | rc = -ENOMEM; | |
1827 | printk(KERN_ERR "Error attempting to allocate from " | |
1828 | "ecryptfs_key_tfm_cache\n"); | |
1829 | goto out; | |
1830 | } | |
1831 | mutex_init(&tmp_tfm->key_tfm_mutex); | |
1832 | strncpy(tmp_tfm->cipher_name, cipher_name, | |
1833 | ECRYPTFS_MAX_CIPHER_NAME_SIZE); | |
1834 | tmp_tfm->key_size = key_size; | |
5dda6992 MH |
1835 | rc = ecryptfs_process_key_cipher(&tmp_tfm->key_tfm, |
1836 | tmp_tfm->cipher_name, | |
1837 | &tmp_tfm->key_size); | |
1838 | if (rc) { | |
f4aad16a MH |
1839 | printk(KERN_ERR "Error attempting to initialize key TFM " |
1840 | "cipher with name = [%s]; rc = [%d]\n", | |
1841 | tmp_tfm->cipher_name, rc); | |
1842 | kmem_cache_free(ecryptfs_key_tfm_cache, tmp_tfm); | |
1843 | if (key_tfm != NULL) | |
1844 | (*key_tfm) = NULL; | |
1845 | goto out; | |
1846 | } | |
1847 | mutex_lock(&key_tfm_list_mutex); | |
1848 | list_add(&tmp_tfm->key_tfm_list, &key_tfm_list); | |
1849 | mutex_unlock(&key_tfm_list_mutex); | |
1850 | out: | |
1851 | return rc; | |
1852 | } | |
1853 | ||
1854 | int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm, | |
1855 | struct mutex **tfm_mutex, | |
1856 | char *cipher_name) | |
1857 | { | |
1858 | struct ecryptfs_key_tfm *key_tfm; | |
1859 | int rc = 0; | |
1860 | ||
1861 | (*tfm) = NULL; | |
1862 | (*tfm_mutex) = NULL; | |
1863 | mutex_lock(&key_tfm_list_mutex); | |
1864 | list_for_each_entry(key_tfm, &key_tfm_list, key_tfm_list) { | |
1865 | if (strcmp(key_tfm->cipher_name, cipher_name) == 0) { | |
1866 | (*tfm) = key_tfm->key_tfm; | |
1867 | (*tfm_mutex) = &key_tfm->key_tfm_mutex; | |
1868 | mutex_unlock(&key_tfm_list_mutex); | |
1869 | goto out; | |
1870 | } | |
1871 | } | |
1872 | mutex_unlock(&key_tfm_list_mutex); | |
5dda6992 MH |
1873 | rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0); |
1874 | if (rc) { | |
f4aad16a MH |
1875 | printk(KERN_ERR "Error adding new key_tfm to list; rc = [%d]\n", |
1876 | rc); | |
1877 | goto out; | |
1878 | } | |
1879 | (*tfm) = key_tfm->key_tfm; | |
1880 | (*tfm_mutex) = &key_tfm->key_tfm_mutex; | |
1881 | out: | |
1882 | return rc; | |
1883 | } |