]>
Commit | Line | Data |
---|---|---|
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> | |
29335c6a | 36 | #include <asm/unaligned.h> |
237fead6 MH |
37 | #include "ecryptfs_kernel.h" |
38 | ||
39 | static int | |
40 | ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
41 | struct page *dst_page, int dst_offset, | |
42 | struct page *src_page, int src_offset, int size, | |
43 | unsigned char *iv); | |
44 | static int | |
45 | ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
46 | struct page *dst_page, int dst_offset, | |
47 | struct page *src_page, int src_offset, int size, | |
48 | unsigned char *iv); | |
49 | ||
50 | /** | |
51 | * ecryptfs_to_hex | |
52 | * @dst: Buffer to take hex character representation of contents of | |
53 | * src; must be at least of size (src_size * 2) | |
54 | * @src: Buffer to be converted to a hex string respresentation | |
55 | * @src_size: number of bytes to convert | |
56 | */ | |
57 | void ecryptfs_to_hex(char *dst, char *src, size_t src_size) | |
58 | { | |
59 | int x; | |
60 | ||
61 | for (x = 0; x < src_size; x++) | |
62 | sprintf(&dst[x * 2], "%.2x", (unsigned char)src[x]); | |
63 | } | |
64 | ||
65 | /** | |
66 | * ecryptfs_from_hex | |
67 | * @dst: Buffer to take the bytes from src hex; must be at least of | |
68 | * size (src_size / 2) | |
69 | * @src: Buffer to be converted from a hex string respresentation to raw value | |
70 | * @dst_size: size of dst buffer, or number of hex characters pairs to convert | |
71 | */ | |
72 | void ecryptfs_from_hex(char *dst, char *src, int dst_size) | |
73 | { | |
74 | int x; | |
75 | char tmp[3] = { 0, }; | |
76 | ||
77 | for (x = 0; x < dst_size; x++) { | |
78 | tmp[0] = src[x * 2]; | |
79 | tmp[1] = src[x * 2 + 1]; | |
80 | dst[x] = (unsigned char)simple_strtol(tmp, NULL, 16); | |
81 | } | |
82 | } | |
83 | ||
84 | /** | |
85 | * ecryptfs_calculate_md5 - calculates the md5 of @src | |
86 | * @dst: Pointer to 16 bytes of allocated memory | |
87 | * @crypt_stat: Pointer to crypt_stat struct for the current inode | |
88 | * @src: Data to be md5'd | |
89 | * @len: Length of @src | |
90 | * | |
91 | * Uses the allocated crypto context that crypt_stat references to | |
92 | * generate the MD5 sum of the contents of src. | |
93 | */ | |
94 | static int ecryptfs_calculate_md5(char *dst, | |
95 | struct ecryptfs_crypt_stat *crypt_stat, | |
96 | char *src, int len) | |
97 | { | |
237fead6 | 98 | struct scatterlist sg; |
565d9724 MH |
99 | struct hash_desc desc = { |
100 | .tfm = crypt_stat->hash_tfm, | |
101 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
102 | }; | |
103 | int rc = 0; | |
237fead6 | 104 | |
565d9724 | 105 | mutex_lock(&crypt_stat->cs_hash_tfm_mutex); |
237fead6 | 106 | sg_init_one(&sg, (u8 *)src, len); |
565d9724 MH |
107 | if (!desc.tfm) { |
108 | desc.tfm = crypto_alloc_hash(ECRYPTFS_DEFAULT_HASH, 0, | |
109 | CRYPTO_ALG_ASYNC); | |
110 | if (IS_ERR(desc.tfm)) { | |
111 | rc = PTR_ERR(desc.tfm); | |
237fead6 | 112 | ecryptfs_printk(KERN_ERR, "Error attempting to " |
565d9724 MH |
113 | "allocate crypto context; rc = [%d]\n", |
114 | rc); | |
237fead6 MH |
115 | goto out; |
116 | } | |
565d9724 | 117 | crypt_stat->hash_tfm = desc.tfm; |
237fead6 | 118 | } |
8a29f2b0 MH |
119 | rc = crypto_hash_init(&desc); |
120 | if (rc) { | |
121 | printk(KERN_ERR | |
122 | "%s: Error initializing crypto hash; rc = [%d]\n", | |
18d1dbf1 | 123 | __func__, rc); |
8a29f2b0 MH |
124 | goto out; |
125 | } | |
126 | rc = crypto_hash_update(&desc, &sg, len); | |
127 | if (rc) { | |
128 | printk(KERN_ERR | |
129 | "%s: Error updating crypto hash; rc = [%d]\n", | |
18d1dbf1 | 130 | __func__, rc); |
8a29f2b0 MH |
131 | goto out; |
132 | } | |
133 | rc = crypto_hash_final(&desc, dst); | |
134 | if (rc) { | |
135 | printk(KERN_ERR | |
136 | "%s: Error finalizing crypto hash; rc = [%d]\n", | |
18d1dbf1 | 137 | __func__, rc); |
8a29f2b0 MH |
138 | goto out; |
139 | } | |
237fead6 | 140 | out: |
8a29f2b0 | 141 | mutex_unlock(&crypt_stat->cs_hash_tfm_mutex); |
237fead6 MH |
142 | return rc; |
143 | } | |
144 | ||
cd9d67df MH |
145 | static int ecryptfs_crypto_api_algify_cipher_name(char **algified_name, |
146 | char *cipher_name, | |
147 | char *chaining_modifier) | |
8bba066f MH |
148 | { |
149 | int cipher_name_len = strlen(cipher_name); | |
150 | int chaining_modifier_len = strlen(chaining_modifier); | |
151 | int algified_name_len; | |
152 | int rc; | |
153 | ||
154 | algified_name_len = (chaining_modifier_len + cipher_name_len + 3); | |
155 | (*algified_name) = kmalloc(algified_name_len, GFP_KERNEL); | |
7bd473fc | 156 | if (!(*algified_name)) { |
8bba066f MH |
157 | rc = -ENOMEM; |
158 | goto out; | |
159 | } | |
160 | snprintf((*algified_name), algified_name_len, "%s(%s)", | |
161 | chaining_modifier, cipher_name); | |
162 | rc = 0; | |
163 | out: | |
164 | return rc; | |
165 | } | |
166 | ||
237fead6 MH |
167 | /** |
168 | * ecryptfs_derive_iv | |
169 | * @iv: destination for the derived iv vale | |
170 | * @crypt_stat: Pointer to crypt_stat struct for the current inode | |
d6a13c17 | 171 | * @offset: Offset of the extent whose IV we are to derive |
237fead6 MH |
172 | * |
173 | * Generate the initialization vector from the given root IV and page | |
174 | * offset. | |
175 | * | |
176 | * Returns zero on success; non-zero on error. | |
177 | */ | |
178 | static int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat, | |
d6a13c17 | 179 | loff_t offset) |
237fead6 MH |
180 | { |
181 | int rc = 0; | |
182 | char dst[MD5_DIGEST_SIZE]; | |
183 | char src[ECRYPTFS_MAX_IV_BYTES + 16]; | |
184 | ||
185 | if (unlikely(ecryptfs_verbosity > 0)) { | |
186 | ecryptfs_printk(KERN_DEBUG, "root iv:\n"); | |
187 | ecryptfs_dump_hex(crypt_stat->root_iv, crypt_stat->iv_bytes); | |
188 | } | |
189 | /* TODO: It is probably secure to just cast the least | |
190 | * significant bits of the root IV into an unsigned long and | |
191 | * add the offset to that rather than go through all this | |
192 | * hashing business. -Halcrow */ | |
193 | memcpy(src, crypt_stat->root_iv, crypt_stat->iv_bytes); | |
194 | memset((src + crypt_stat->iv_bytes), 0, 16); | |
d6a13c17 | 195 | snprintf((src + crypt_stat->iv_bytes), 16, "%lld", offset); |
237fead6 MH |
196 | if (unlikely(ecryptfs_verbosity > 0)) { |
197 | ecryptfs_printk(KERN_DEBUG, "source:\n"); | |
198 | ecryptfs_dump_hex(src, (crypt_stat->iv_bytes + 16)); | |
199 | } | |
200 | rc = ecryptfs_calculate_md5(dst, crypt_stat, src, | |
201 | (crypt_stat->iv_bytes + 16)); | |
202 | if (rc) { | |
203 | ecryptfs_printk(KERN_WARNING, "Error attempting to compute " | |
204 | "MD5 while generating IV for a page\n"); | |
205 | goto out; | |
206 | } | |
207 | memcpy(iv, dst, crypt_stat->iv_bytes); | |
208 | if (unlikely(ecryptfs_verbosity > 0)) { | |
209 | ecryptfs_printk(KERN_DEBUG, "derived iv:\n"); | |
210 | ecryptfs_dump_hex(iv, crypt_stat->iv_bytes); | |
211 | } | |
212 | out: | |
213 | return rc; | |
214 | } | |
215 | ||
216 | /** | |
217 | * ecryptfs_init_crypt_stat | |
218 | * @crypt_stat: Pointer to the crypt_stat struct to initialize. | |
219 | * | |
220 | * Initialize the crypt_stat structure. | |
221 | */ | |
222 | void | |
223 | ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat) | |
224 | { | |
225 | memset((void *)crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat)); | |
f4aad16a MH |
226 | INIT_LIST_HEAD(&crypt_stat->keysig_list); |
227 | mutex_init(&crypt_stat->keysig_list_mutex); | |
237fead6 MH |
228 | mutex_init(&crypt_stat->cs_mutex); |
229 | mutex_init(&crypt_stat->cs_tfm_mutex); | |
565d9724 | 230 | mutex_init(&crypt_stat->cs_hash_tfm_mutex); |
e2bd99ec | 231 | crypt_stat->flags |= ECRYPTFS_STRUCT_INITIALIZED; |
237fead6 MH |
232 | } |
233 | ||
234 | /** | |
fcd12835 | 235 | * ecryptfs_destroy_crypt_stat |
237fead6 MH |
236 | * @crypt_stat: Pointer to the crypt_stat struct to initialize. |
237 | * | |
238 | * Releases all memory associated with a crypt_stat struct. | |
239 | */ | |
fcd12835 | 240 | void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat) |
237fead6 | 241 | { |
f4aad16a MH |
242 | struct ecryptfs_key_sig *key_sig, *key_sig_tmp; |
243 | ||
237fead6 | 244 | if (crypt_stat->tfm) |
8bba066f | 245 | crypto_free_blkcipher(crypt_stat->tfm); |
565d9724 MH |
246 | if (crypt_stat->hash_tfm) |
247 | crypto_free_hash(crypt_stat->hash_tfm); | |
f4aad16a MH |
248 | mutex_lock(&crypt_stat->keysig_list_mutex); |
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 | } | |
254 | mutex_unlock(&crypt_stat->keysig_list_mutex); | |
237fead6 MH |
255 | memset(crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat)); |
256 | } | |
257 | ||
fcd12835 | 258 | void ecryptfs_destroy_mount_crypt_stat( |
237fead6 MH |
259 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) |
260 | { | |
f4aad16a MH |
261 | struct ecryptfs_global_auth_tok *auth_tok, *auth_tok_tmp; |
262 | ||
263 | if (!(mount_crypt_stat->flags & ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED)) | |
264 | return; | |
265 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
266 | list_for_each_entry_safe(auth_tok, auth_tok_tmp, | |
267 | &mount_crypt_stat->global_auth_tok_list, | |
268 | mount_crypt_stat_list) { | |
269 | list_del(&auth_tok->mount_crypt_stat_list); | |
270 | mount_crypt_stat->num_global_auth_toks--; | |
271 | if (auth_tok->global_auth_tok_key | |
272 | && !(auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID)) | |
273 | key_put(auth_tok->global_auth_tok_key); | |
274 | kmem_cache_free(ecryptfs_global_auth_tok_cache, auth_tok); | |
275 | } | |
276 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
237fead6 MH |
277 | memset(mount_crypt_stat, 0, sizeof(struct ecryptfs_mount_crypt_stat)); |
278 | } | |
279 | ||
280 | /** | |
281 | * virt_to_scatterlist | |
282 | * @addr: Virtual address | |
283 | * @size: Size of data; should be an even multiple of the block size | |
284 | * @sg: Pointer to scatterlist array; set to NULL to obtain only | |
285 | * the number of scatterlist structs required in array | |
286 | * @sg_size: Max array size | |
287 | * | |
288 | * Fills in a scatterlist array with page references for a passed | |
289 | * virtual address. | |
290 | * | |
291 | * Returns the number of scatterlist structs in array used | |
292 | */ | |
293 | int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg, | |
294 | int sg_size) | |
295 | { | |
296 | int i = 0; | |
297 | struct page *pg; | |
298 | int offset; | |
299 | int remainder_of_page; | |
300 | ||
68e3f5dd HX |
301 | sg_init_table(sg, sg_size); |
302 | ||
237fead6 MH |
303 | while (size > 0 && i < sg_size) { |
304 | pg = virt_to_page(addr); | |
305 | offset = offset_in_page(addr); | |
642f1490 JA |
306 | if (sg) |
307 | sg_set_page(&sg[i], pg, 0, offset); | |
237fead6 MH |
308 | remainder_of_page = PAGE_CACHE_SIZE - offset; |
309 | if (size >= remainder_of_page) { | |
310 | if (sg) | |
311 | sg[i].length = remainder_of_page; | |
312 | addr += remainder_of_page; | |
313 | size -= remainder_of_page; | |
314 | } else { | |
315 | if (sg) | |
316 | sg[i].length = size; | |
317 | addr += size; | |
318 | size = 0; | |
319 | } | |
320 | i++; | |
321 | } | |
322 | if (size > 0) | |
323 | return -ENOMEM; | |
324 | return i; | |
325 | } | |
326 | ||
327 | /** | |
328 | * encrypt_scatterlist | |
329 | * @crypt_stat: Pointer to the crypt_stat struct to initialize. | |
330 | * @dest_sg: Destination of encrypted data | |
331 | * @src_sg: Data to be encrypted | |
332 | * @size: Length of data to be encrypted | |
333 | * @iv: iv to use during encryption | |
334 | * | |
335 | * Returns the number of bytes encrypted; negative value on error | |
336 | */ | |
337 | static int encrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, | |
338 | struct scatterlist *dest_sg, | |
339 | struct scatterlist *src_sg, int size, | |
340 | unsigned char *iv) | |
341 | { | |
8bba066f MH |
342 | struct blkcipher_desc desc = { |
343 | .tfm = crypt_stat->tfm, | |
344 | .info = iv, | |
345 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
346 | }; | |
237fead6 MH |
347 | int rc = 0; |
348 | ||
349 | BUG_ON(!crypt_stat || !crypt_stat->tfm | |
e2bd99ec | 350 | || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)); |
237fead6 MH |
351 | if (unlikely(ecryptfs_verbosity > 0)) { |
352 | ecryptfs_printk(KERN_DEBUG, "Key size [%d]; key:\n", | |
353 | crypt_stat->key_size); | |
354 | ecryptfs_dump_hex(crypt_stat->key, | |
355 | crypt_stat->key_size); | |
356 | } | |
357 | /* Consider doing this once, when the file is opened */ | |
358 | mutex_lock(&crypt_stat->cs_tfm_mutex); | |
8e3a6f16 TH |
359 | if (!(crypt_stat->flags & ECRYPTFS_KEY_SET)) { |
360 | rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key, | |
361 | crypt_stat->key_size); | |
362 | crypt_stat->flags |= ECRYPTFS_KEY_SET; | |
363 | } | |
237fead6 MH |
364 | if (rc) { |
365 | ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n", | |
366 | rc); | |
367 | mutex_unlock(&crypt_stat->cs_tfm_mutex); | |
368 | rc = -EINVAL; | |
369 | goto out; | |
370 | } | |
371 | ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes.\n", size); | |
8bba066f | 372 | crypto_blkcipher_encrypt_iv(&desc, dest_sg, src_sg, size); |
237fead6 MH |
373 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
374 | out: | |
375 | return rc; | |
376 | } | |
377 | ||
0216f7f7 MH |
378 | /** |
379 | * ecryptfs_lower_offset_for_extent | |
380 | * | |
381 | * Convert an eCryptfs page index into a lower byte offset | |
382 | */ | |
7896b631 AB |
383 | static void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num, |
384 | struct ecryptfs_crypt_stat *crypt_stat) | |
0216f7f7 | 385 | { |
cc11beff | 386 | (*offset) = (crypt_stat->num_header_bytes_at_front |
0216f7f7 MH |
387 | + (crypt_stat->extent_size * extent_num)); |
388 | } | |
389 | ||
390 | /** | |
391 | * ecryptfs_encrypt_extent | |
392 | * @enc_extent_page: Allocated page into which to encrypt the data in | |
393 | * @page | |
394 | * @crypt_stat: crypt_stat containing cryptographic context for the | |
395 | * encryption operation | |
396 | * @page: Page containing plaintext data extent to encrypt | |
397 | * @extent_offset: Page extent offset for use in generating IV | |
398 | * | |
399 | * Encrypts one extent of data. | |
400 | * | |
401 | * Return zero on success; non-zero otherwise | |
402 | */ | |
403 | static int ecryptfs_encrypt_extent(struct page *enc_extent_page, | |
404 | struct ecryptfs_crypt_stat *crypt_stat, | |
405 | struct page *page, | |
406 | unsigned long extent_offset) | |
407 | { | |
d6a13c17 | 408 | loff_t extent_base; |
0216f7f7 MH |
409 | char extent_iv[ECRYPTFS_MAX_IV_BYTES]; |
410 | int rc; | |
411 | ||
d6a13c17 | 412 | extent_base = (((loff_t)page->index) |
0216f7f7 MH |
413 | * (PAGE_CACHE_SIZE / crypt_stat->extent_size)); |
414 | rc = ecryptfs_derive_iv(extent_iv, crypt_stat, | |
415 | (extent_base + extent_offset)); | |
416 | if (rc) { | |
417 | ecryptfs_printk(KERN_ERR, "Error attempting to " | |
418 | "derive IV for extent [0x%.16x]; " | |
419 | "rc = [%d]\n", (extent_base + extent_offset), | |
420 | rc); | |
421 | goto out; | |
422 | } | |
423 | if (unlikely(ecryptfs_verbosity > 0)) { | |
424 | ecryptfs_printk(KERN_DEBUG, "Encrypting extent " | |
425 | "with iv:\n"); | |
426 | ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes); | |
427 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes before " | |
428 | "encryption:\n"); | |
429 | ecryptfs_dump_hex((char *) | |
430 | (page_address(page) | |
431 | + (extent_offset * crypt_stat->extent_size)), | |
432 | 8); | |
433 | } | |
434 | rc = ecryptfs_encrypt_page_offset(crypt_stat, enc_extent_page, 0, | |
435 | page, (extent_offset | |
436 | * crypt_stat->extent_size), | |
437 | crypt_stat->extent_size, extent_iv); | |
438 | if (rc < 0) { | |
439 | printk(KERN_ERR "%s: Error attempting to encrypt page with " | |
440 | "page->index = [%ld], extent_offset = [%ld]; " | |
18d1dbf1 | 441 | "rc = [%d]\n", __func__, page->index, extent_offset, |
0216f7f7 MH |
442 | rc); |
443 | goto out; | |
444 | } | |
445 | rc = 0; | |
446 | if (unlikely(ecryptfs_verbosity > 0)) { | |
447 | ecryptfs_printk(KERN_DEBUG, "Encrypt extent [0x%.16x]; " | |
448 | "rc = [%d]\n", (extent_base + extent_offset), | |
449 | rc); | |
450 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes after " | |
451 | "encryption:\n"); | |
452 | ecryptfs_dump_hex((char *)(page_address(enc_extent_page)), 8); | |
453 | } | |
454 | out: | |
455 | return rc; | |
456 | } | |
457 | ||
237fead6 MH |
458 | /** |
459 | * ecryptfs_encrypt_page | |
0216f7f7 MH |
460 | * @page: Page mapped from the eCryptfs inode for the file; contains |
461 | * decrypted content that needs to be encrypted (to a temporary | |
462 | * page; not in place) and written out to the lower file | |
237fead6 MH |
463 | * |
464 | * Encrypt an eCryptfs page. This is done on a per-extent basis. Note | |
465 | * that eCryptfs pages may straddle the lower pages -- for instance, | |
466 | * if the file was created on a machine with an 8K page size | |
467 | * (resulting in an 8K header), and then the file is copied onto a | |
468 | * host with a 32K page size, then when reading page 0 of the eCryptfs | |
469 | * file, 24K of page 0 of the lower file will be read and decrypted, | |
470 | * and then 8K of page 1 of the lower file will be read and decrypted. | |
471 | * | |
237fead6 MH |
472 | * Returns zero on success; negative on error |
473 | */ | |
0216f7f7 | 474 | int ecryptfs_encrypt_page(struct page *page) |
237fead6 | 475 | { |
0216f7f7 | 476 | struct inode *ecryptfs_inode; |
237fead6 | 477 | struct ecryptfs_crypt_stat *crypt_stat; |
7fcba054 ES |
478 | char *enc_extent_virt; |
479 | struct page *enc_extent_page = NULL; | |
0216f7f7 | 480 | loff_t extent_offset; |
237fead6 | 481 | int rc = 0; |
0216f7f7 MH |
482 | |
483 | ecryptfs_inode = page->mapping->host; | |
484 | crypt_stat = | |
485 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); | |
e2bd99ec | 486 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
0216f7f7 MH |
487 | rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page, |
488 | 0, PAGE_CACHE_SIZE); | |
237fead6 | 489 | if (rc) |
0216f7f7 | 490 | printk(KERN_ERR "%s: Error attempting to copy " |
18d1dbf1 | 491 | "page at index [%ld]\n", __func__, |
0216f7f7 | 492 | page->index); |
237fead6 MH |
493 | goto out; |
494 | } | |
7fcba054 ES |
495 | enc_extent_page = alloc_page(GFP_USER); |
496 | if (!enc_extent_page) { | |
0216f7f7 MH |
497 | rc = -ENOMEM; |
498 | ecryptfs_printk(KERN_ERR, "Error allocating memory for " | |
499 | "encrypted extent\n"); | |
500 | goto out; | |
501 | } | |
7fcba054 | 502 | enc_extent_virt = kmap(enc_extent_page); |
0216f7f7 MH |
503 | for (extent_offset = 0; |
504 | extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); | |
505 | extent_offset++) { | |
506 | loff_t offset; | |
507 | ||
508 | rc = ecryptfs_encrypt_extent(enc_extent_page, crypt_stat, page, | |
509 | extent_offset); | |
237fead6 | 510 | if (rc) { |
0216f7f7 | 511 | printk(KERN_ERR "%s: Error encrypting extent; " |
18d1dbf1 | 512 | "rc = [%d]\n", __func__, rc); |
237fead6 MH |
513 | goto out; |
514 | } | |
0216f7f7 | 515 | ecryptfs_lower_offset_for_extent( |
d6a13c17 MH |
516 | &offset, ((((loff_t)page->index) |
517 | * (PAGE_CACHE_SIZE | |
518 | / crypt_stat->extent_size)) | |
0216f7f7 MH |
519 | + extent_offset), crypt_stat); |
520 | rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt, | |
521 | offset, crypt_stat->extent_size); | |
522 | if (rc) { | |
523 | ecryptfs_printk(KERN_ERR, "Error attempting " | |
524 | "to write lower page; rc = [%d]" | |
525 | "\n", rc); | |
526 | goto out; | |
237fead6 | 527 | } |
237fead6 | 528 | } |
0216f7f7 | 529 | out: |
7fcba054 ES |
530 | if (enc_extent_page) { |
531 | kunmap(enc_extent_page); | |
532 | __free_page(enc_extent_page); | |
533 | } | |
0216f7f7 MH |
534 | return rc; |
535 | } | |
536 | ||
537 | static int ecryptfs_decrypt_extent(struct page *page, | |
538 | struct ecryptfs_crypt_stat *crypt_stat, | |
539 | struct page *enc_extent_page, | |
540 | unsigned long extent_offset) | |
541 | { | |
d6a13c17 | 542 | loff_t extent_base; |
0216f7f7 MH |
543 | char extent_iv[ECRYPTFS_MAX_IV_BYTES]; |
544 | int rc; | |
545 | ||
d6a13c17 | 546 | extent_base = (((loff_t)page->index) |
0216f7f7 MH |
547 | * (PAGE_CACHE_SIZE / crypt_stat->extent_size)); |
548 | rc = ecryptfs_derive_iv(extent_iv, crypt_stat, | |
549 | (extent_base + extent_offset)); | |
237fead6 | 550 | if (rc) { |
0216f7f7 MH |
551 | ecryptfs_printk(KERN_ERR, "Error attempting to " |
552 | "derive IV for extent [0x%.16x]; " | |
553 | "rc = [%d]\n", (extent_base + extent_offset), | |
554 | rc); | |
555 | goto out; | |
556 | } | |
557 | if (unlikely(ecryptfs_verbosity > 0)) { | |
558 | ecryptfs_printk(KERN_DEBUG, "Decrypting extent " | |
559 | "with iv:\n"); | |
560 | ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes); | |
561 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes before " | |
562 | "decryption:\n"); | |
563 | ecryptfs_dump_hex((char *) | |
564 | (page_address(enc_extent_page) | |
565 | + (extent_offset * crypt_stat->extent_size)), | |
566 | 8); | |
567 | } | |
568 | rc = ecryptfs_decrypt_page_offset(crypt_stat, page, | |
569 | (extent_offset | |
570 | * crypt_stat->extent_size), | |
571 | enc_extent_page, 0, | |
572 | crypt_stat->extent_size, extent_iv); | |
573 | if (rc < 0) { | |
574 | printk(KERN_ERR "%s: Error attempting to decrypt to page with " | |
575 | "page->index = [%ld], extent_offset = [%ld]; " | |
18d1dbf1 | 576 | "rc = [%d]\n", __func__, page->index, extent_offset, |
0216f7f7 MH |
577 | rc); |
578 | goto out; | |
579 | } | |
580 | rc = 0; | |
581 | if (unlikely(ecryptfs_verbosity > 0)) { | |
582 | ecryptfs_printk(KERN_DEBUG, "Decrypt extent [0x%.16x]; " | |
583 | "rc = [%d]\n", (extent_base + extent_offset), | |
584 | rc); | |
585 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes after " | |
586 | "decryption:\n"); | |
587 | ecryptfs_dump_hex((char *)(page_address(page) | |
588 | + (extent_offset | |
589 | * crypt_stat->extent_size)), 8); | |
237fead6 MH |
590 | } |
591 | out: | |
592 | return rc; | |
593 | } | |
594 | ||
595 | /** | |
596 | * ecryptfs_decrypt_page | |
0216f7f7 MH |
597 | * @page: Page mapped from the eCryptfs inode for the file; data read |
598 | * and decrypted from the lower file will be written into this | |
599 | * page | |
237fead6 MH |
600 | * |
601 | * Decrypt an eCryptfs page. This is done on a per-extent basis. Note | |
602 | * that eCryptfs pages may straddle the lower pages -- for instance, | |
603 | * if the file was created on a machine with an 8K page size | |
604 | * (resulting in an 8K header), and then the file is copied onto a | |
605 | * host with a 32K page size, then when reading page 0 of the eCryptfs | |
606 | * file, 24K of page 0 of the lower file will be read and decrypted, | |
607 | * and then 8K of page 1 of the lower file will be read and decrypted. | |
608 | * | |
609 | * Returns zero on success; negative on error | |
610 | */ | |
0216f7f7 | 611 | int ecryptfs_decrypt_page(struct page *page) |
237fead6 | 612 | { |
0216f7f7 | 613 | struct inode *ecryptfs_inode; |
237fead6 | 614 | struct ecryptfs_crypt_stat *crypt_stat; |
7fcba054 ES |
615 | char *enc_extent_virt; |
616 | struct page *enc_extent_page = NULL; | |
0216f7f7 | 617 | unsigned long extent_offset; |
237fead6 | 618 | int rc = 0; |
237fead6 | 619 | |
0216f7f7 MH |
620 | ecryptfs_inode = page->mapping->host; |
621 | crypt_stat = | |
622 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); | |
e2bd99ec | 623 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
0216f7f7 MH |
624 | rc = ecryptfs_read_lower_page_segment(page, page->index, 0, |
625 | PAGE_CACHE_SIZE, | |
626 | ecryptfs_inode); | |
237fead6 | 627 | if (rc) |
0216f7f7 | 628 | printk(KERN_ERR "%s: Error attempting to copy " |
18d1dbf1 | 629 | "page at index [%ld]\n", __func__, |
0216f7f7 | 630 | page->index); |
16a72c45 | 631 | goto out; |
237fead6 | 632 | } |
7fcba054 ES |
633 | enc_extent_page = alloc_page(GFP_USER); |
634 | if (!enc_extent_page) { | |
237fead6 | 635 | rc = -ENOMEM; |
0216f7f7 MH |
636 | ecryptfs_printk(KERN_ERR, "Error allocating memory for " |
637 | "encrypted extent\n"); | |
16a72c45 | 638 | goto out; |
237fead6 | 639 | } |
7fcba054 | 640 | enc_extent_virt = kmap(enc_extent_page); |
0216f7f7 MH |
641 | for (extent_offset = 0; |
642 | extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); | |
643 | extent_offset++) { | |
644 | loff_t offset; | |
645 | ||
646 | ecryptfs_lower_offset_for_extent( | |
647 | &offset, ((page->index * (PAGE_CACHE_SIZE | |
648 | / crypt_stat->extent_size)) | |
649 | + extent_offset), crypt_stat); | |
650 | rc = ecryptfs_read_lower(enc_extent_virt, offset, | |
651 | crypt_stat->extent_size, | |
652 | ecryptfs_inode); | |
237fead6 | 653 | if (rc) { |
0216f7f7 MH |
654 | ecryptfs_printk(KERN_ERR, "Error attempting " |
655 | "to read lower page; rc = [%d]" | |
656 | "\n", rc); | |
16a72c45 | 657 | goto out; |
237fead6 | 658 | } |
0216f7f7 MH |
659 | rc = ecryptfs_decrypt_extent(page, crypt_stat, enc_extent_page, |
660 | extent_offset); | |
661 | if (rc) { | |
662 | printk(KERN_ERR "%s: Error encrypting extent; " | |
18d1dbf1 | 663 | "rc = [%d]\n", __func__, rc); |
16a72c45 | 664 | goto out; |
237fead6 | 665 | } |
237fead6 MH |
666 | } |
667 | out: | |
7fcba054 ES |
668 | if (enc_extent_page) { |
669 | kunmap(enc_extent_page); | |
670 | __free_page(enc_extent_page); | |
671 | } | |
237fead6 MH |
672 | return rc; |
673 | } | |
674 | ||
675 | /** | |
676 | * decrypt_scatterlist | |
22e78faf MH |
677 | * @crypt_stat: Cryptographic context |
678 | * @dest_sg: The destination scatterlist to decrypt into | |
679 | * @src_sg: The source scatterlist to decrypt from | |
680 | * @size: The number of bytes to decrypt | |
681 | * @iv: The initialization vector to use for the decryption | |
237fead6 MH |
682 | * |
683 | * Returns the number of bytes decrypted; negative value on error | |
684 | */ | |
685 | static int decrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, | |
686 | struct scatterlist *dest_sg, | |
687 | struct scatterlist *src_sg, int size, | |
688 | unsigned char *iv) | |
689 | { | |
8bba066f MH |
690 | struct blkcipher_desc desc = { |
691 | .tfm = crypt_stat->tfm, | |
692 | .info = iv, | |
693 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
694 | }; | |
237fead6 MH |
695 | int rc = 0; |
696 | ||
697 | /* Consider doing this once, when the file is opened */ | |
698 | mutex_lock(&crypt_stat->cs_tfm_mutex); | |
8bba066f MH |
699 | rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key, |
700 | crypt_stat->key_size); | |
237fead6 MH |
701 | if (rc) { |
702 | ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n", | |
703 | rc); | |
704 | mutex_unlock(&crypt_stat->cs_tfm_mutex); | |
705 | rc = -EINVAL; | |
706 | goto out; | |
707 | } | |
708 | ecryptfs_printk(KERN_DEBUG, "Decrypting [%d] bytes.\n", size); | |
8bba066f | 709 | rc = crypto_blkcipher_decrypt_iv(&desc, dest_sg, src_sg, size); |
237fead6 MH |
710 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
711 | if (rc) { | |
712 | ecryptfs_printk(KERN_ERR, "Error decrypting; rc = [%d]\n", | |
713 | rc); | |
714 | goto out; | |
715 | } | |
716 | rc = size; | |
717 | out: | |
718 | return rc; | |
719 | } | |
720 | ||
721 | /** | |
722 | * ecryptfs_encrypt_page_offset | |
22e78faf MH |
723 | * @crypt_stat: The cryptographic context |
724 | * @dst_page: The page to encrypt into | |
725 | * @dst_offset: The offset in the page to encrypt into | |
726 | * @src_page: The page to encrypt from | |
727 | * @src_offset: The offset in the page to encrypt from | |
728 | * @size: The number of bytes to encrypt | |
729 | * @iv: The initialization vector to use for the encryption | |
237fead6 MH |
730 | * |
731 | * Returns the number of bytes encrypted | |
732 | */ | |
733 | static int | |
734 | ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
735 | struct page *dst_page, int dst_offset, | |
736 | struct page *src_page, int src_offset, int size, | |
737 | unsigned char *iv) | |
738 | { | |
739 | struct scatterlist src_sg, dst_sg; | |
740 | ||
60c74f81 JA |
741 | sg_init_table(&src_sg, 1); |
742 | sg_init_table(&dst_sg, 1); | |
743 | ||
642f1490 JA |
744 | sg_set_page(&src_sg, src_page, size, src_offset); |
745 | sg_set_page(&dst_sg, dst_page, size, dst_offset); | |
237fead6 MH |
746 | return encrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); |
747 | } | |
748 | ||
749 | /** | |
750 | * ecryptfs_decrypt_page_offset | |
22e78faf MH |
751 | * @crypt_stat: The cryptographic context |
752 | * @dst_page: The page to decrypt into | |
753 | * @dst_offset: The offset in the page to decrypt into | |
754 | * @src_page: The page to decrypt from | |
755 | * @src_offset: The offset in the page to decrypt from | |
756 | * @size: The number of bytes to decrypt | |
757 | * @iv: The initialization vector to use for the decryption | |
237fead6 MH |
758 | * |
759 | * Returns the number of bytes decrypted | |
760 | */ | |
761 | static int | |
762 | ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
763 | struct page *dst_page, int dst_offset, | |
764 | struct page *src_page, int src_offset, int size, | |
765 | unsigned char *iv) | |
766 | { | |
767 | struct scatterlist src_sg, dst_sg; | |
768 | ||
60c74f81 | 769 | sg_init_table(&src_sg, 1); |
642f1490 JA |
770 | sg_set_page(&src_sg, src_page, size, src_offset); |
771 | ||
60c74f81 | 772 | sg_init_table(&dst_sg, 1); |
642f1490 | 773 | sg_set_page(&dst_sg, dst_page, size, dst_offset); |
60c74f81 | 774 | |
237fead6 MH |
775 | return decrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); |
776 | } | |
777 | ||
778 | #define ECRYPTFS_MAX_SCATTERLIST_LEN 4 | |
779 | ||
780 | /** | |
781 | * ecryptfs_init_crypt_ctx | |
782 | * @crypt_stat: Uninitilized crypt stats structure | |
783 | * | |
784 | * Initialize the crypto context. | |
785 | * | |
786 | * TODO: Performance: Keep a cache of initialized cipher contexts; | |
787 | * only init if needed | |
788 | */ | |
789 | int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat) | |
790 | { | |
8bba066f | 791 | char *full_alg_name; |
237fead6 MH |
792 | int rc = -EINVAL; |
793 | ||
794 | if (!crypt_stat->cipher) { | |
795 | ecryptfs_printk(KERN_ERR, "No cipher specified\n"); | |
796 | goto out; | |
797 | } | |
798 | ecryptfs_printk(KERN_DEBUG, | |
799 | "Initializing cipher [%s]; strlen = [%d]; " | |
800 | "key_size_bits = [%d]\n", | |
801 | crypt_stat->cipher, (int)strlen(crypt_stat->cipher), | |
802 | crypt_stat->key_size << 3); | |
803 | if (crypt_stat->tfm) { | |
804 | rc = 0; | |
805 | goto out; | |
806 | } | |
807 | mutex_lock(&crypt_stat->cs_tfm_mutex); | |
8bba066f MH |
808 | rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, |
809 | crypt_stat->cipher, "cbc"); | |
810 | if (rc) | |
c8161f64 | 811 | goto out_unlock; |
8bba066f MH |
812 | crypt_stat->tfm = crypto_alloc_blkcipher(full_alg_name, 0, |
813 | CRYPTO_ALG_ASYNC); | |
814 | kfree(full_alg_name); | |
de88777e AM |
815 | if (IS_ERR(crypt_stat->tfm)) { |
816 | rc = PTR_ERR(crypt_stat->tfm); | |
237fead6 MH |
817 | ecryptfs_printk(KERN_ERR, "cryptfs: init_crypt_ctx(): " |
818 | "Error initializing cipher [%s]\n", | |
819 | crypt_stat->cipher); | |
c8161f64 | 820 | goto out_unlock; |
237fead6 | 821 | } |
f1ddcaf3 | 822 | crypto_blkcipher_set_flags(crypt_stat->tfm, CRYPTO_TFM_REQ_WEAK_KEY); |
237fead6 | 823 | rc = 0; |
c8161f64 ES |
824 | out_unlock: |
825 | mutex_unlock(&crypt_stat->cs_tfm_mutex); | |
237fead6 MH |
826 | out: |
827 | return rc; | |
828 | } | |
829 | ||
830 | static void set_extent_mask_and_shift(struct ecryptfs_crypt_stat *crypt_stat) | |
831 | { | |
832 | int extent_size_tmp; | |
833 | ||
834 | crypt_stat->extent_mask = 0xFFFFFFFF; | |
835 | crypt_stat->extent_shift = 0; | |
836 | if (crypt_stat->extent_size == 0) | |
837 | return; | |
838 | extent_size_tmp = crypt_stat->extent_size; | |
839 | while ((extent_size_tmp & 0x01) == 0) { | |
840 | extent_size_tmp >>= 1; | |
841 | crypt_stat->extent_mask <<= 1; | |
842 | crypt_stat->extent_shift++; | |
843 | } | |
844 | } | |
845 | ||
846 | void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat) | |
847 | { | |
848 | /* Default values; may be overwritten as we are parsing the | |
849 | * packets. */ | |
850 | crypt_stat->extent_size = ECRYPTFS_DEFAULT_EXTENT_SIZE; | |
851 | set_extent_mask_and_shift(crypt_stat); | |
852 | crypt_stat->iv_bytes = ECRYPTFS_DEFAULT_IV_BYTES; | |
dd2a3b7a | 853 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
cc11beff | 854 | crypt_stat->num_header_bytes_at_front = 0; |
45eaab79 MH |
855 | else { |
856 | if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE) | |
cc11beff MH |
857 | crypt_stat->num_header_bytes_at_front = |
858 | ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; | |
45eaab79 | 859 | else |
cc11beff | 860 | crypt_stat->num_header_bytes_at_front = PAGE_CACHE_SIZE; |
45eaab79 | 861 | } |
237fead6 MH |
862 | } |
863 | ||
864 | /** | |
865 | * ecryptfs_compute_root_iv | |
866 | * @crypt_stats | |
867 | * | |
868 | * On error, sets the root IV to all 0's. | |
869 | */ | |
870 | int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat) | |
871 | { | |
872 | int rc = 0; | |
873 | char dst[MD5_DIGEST_SIZE]; | |
874 | ||
875 | BUG_ON(crypt_stat->iv_bytes > MD5_DIGEST_SIZE); | |
876 | BUG_ON(crypt_stat->iv_bytes <= 0); | |
e2bd99ec | 877 | if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { |
237fead6 MH |
878 | rc = -EINVAL; |
879 | ecryptfs_printk(KERN_WARNING, "Session key not valid; " | |
880 | "cannot generate root IV\n"); | |
881 | goto out; | |
882 | } | |
883 | rc = ecryptfs_calculate_md5(dst, crypt_stat, crypt_stat->key, | |
884 | crypt_stat->key_size); | |
885 | if (rc) { | |
886 | ecryptfs_printk(KERN_WARNING, "Error attempting to compute " | |
887 | "MD5 while generating root IV\n"); | |
888 | goto out; | |
889 | } | |
890 | memcpy(crypt_stat->root_iv, dst, crypt_stat->iv_bytes); | |
891 | out: | |
892 | if (rc) { | |
893 | memset(crypt_stat->root_iv, 0, crypt_stat->iv_bytes); | |
e2bd99ec | 894 | crypt_stat->flags |= ECRYPTFS_SECURITY_WARNING; |
237fead6 MH |
895 | } |
896 | return rc; | |
897 | } | |
898 | ||
899 | static void ecryptfs_generate_new_key(struct ecryptfs_crypt_stat *crypt_stat) | |
900 | { | |
901 | get_random_bytes(crypt_stat->key, crypt_stat->key_size); | |
e2bd99ec | 902 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; |
237fead6 MH |
903 | ecryptfs_compute_root_iv(crypt_stat); |
904 | if (unlikely(ecryptfs_verbosity > 0)) { | |
905 | ecryptfs_printk(KERN_DEBUG, "Generated new session key:\n"); | |
906 | ecryptfs_dump_hex(crypt_stat->key, | |
907 | crypt_stat->key_size); | |
908 | } | |
909 | } | |
910 | ||
17398957 MH |
911 | /** |
912 | * ecryptfs_copy_mount_wide_flags_to_inode_flags | |
22e78faf MH |
913 | * @crypt_stat: The inode's cryptographic context |
914 | * @mount_crypt_stat: The mount point's cryptographic context | |
17398957 MH |
915 | * |
916 | * This function propagates the mount-wide flags to individual inode | |
917 | * flags. | |
918 | */ | |
919 | static void ecryptfs_copy_mount_wide_flags_to_inode_flags( | |
920 | struct ecryptfs_crypt_stat *crypt_stat, | |
921 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
922 | { | |
923 | if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) | |
924 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; | |
925 | if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) | |
926 | crypt_stat->flags |= ECRYPTFS_VIEW_AS_ENCRYPTED; | |
927 | } | |
928 | ||
f4aad16a MH |
929 | static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs( |
930 | struct ecryptfs_crypt_stat *crypt_stat, | |
931 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
932 | { | |
933 | struct ecryptfs_global_auth_tok *global_auth_tok; | |
934 | int rc = 0; | |
935 | ||
936 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
937 | list_for_each_entry(global_auth_tok, | |
938 | &mount_crypt_stat->global_auth_tok_list, | |
939 | mount_crypt_stat_list) { | |
940 | rc = ecryptfs_add_keysig(crypt_stat, global_auth_tok->sig); | |
941 | if (rc) { | |
942 | printk(KERN_ERR "Error adding keysig; rc = [%d]\n", rc); | |
943 | mutex_unlock( | |
944 | &mount_crypt_stat->global_auth_tok_list_mutex); | |
945 | goto out; | |
946 | } | |
947 | } | |
948 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
949 | out: | |
950 | return rc; | |
951 | } | |
952 | ||
237fead6 MH |
953 | /** |
954 | * ecryptfs_set_default_crypt_stat_vals | |
22e78faf MH |
955 | * @crypt_stat: The inode's cryptographic context |
956 | * @mount_crypt_stat: The mount point's cryptographic context | |
237fead6 MH |
957 | * |
958 | * Default values in the event that policy does not override them. | |
959 | */ | |
960 | static void ecryptfs_set_default_crypt_stat_vals( | |
961 | struct ecryptfs_crypt_stat *crypt_stat, | |
962 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
963 | { | |
17398957 MH |
964 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
965 | mount_crypt_stat); | |
237fead6 MH |
966 | ecryptfs_set_default_sizes(crypt_stat); |
967 | strcpy(crypt_stat->cipher, ECRYPTFS_DEFAULT_CIPHER); | |
968 | crypt_stat->key_size = ECRYPTFS_DEFAULT_KEY_BYTES; | |
e2bd99ec | 969 | crypt_stat->flags &= ~(ECRYPTFS_KEY_VALID); |
237fead6 MH |
970 | crypt_stat->file_version = ECRYPTFS_FILE_VERSION; |
971 | crypt_stat->mount_crypt_stat = mount_crypt_stat; | |
972 | } | |
973 | ||
974 | /** | |
975 | * ecryptfs_new_file_context | |
22e78faf | 976 | * @ecryptfs_dentry: The eCryptfs dentry |
237fead6 MH |
977 | * |
978 | * If the crypto context for the file has not yet been established, | |
979 | * this is where we do that. Establishing a new crypto context | |
980 | * involves the following decisions: | |
981 | * - What cipher to use? | |
982 | * - What set of authentication tokens to use? | |
983 | * Here we just worry about getting enough information into the | |
984 | * authentication tokens so that we know that they are available. | |
985 | * We associate the available authentication tokens with the new file | |
986 | * via the set of signatures in the crypt_stat struct. Later, when | |
987 | * the headers are actually written out, we may again defer to | |
988 | * userspace to perform the encryption of the session key; for the | |
989 | * foreseeable future, this will be the case with public key packets. | |
990 | * | |
991 | * Returns zero on success; non-zero otherwise | |
992 | */ | |
237fead6 MH |
993 | int ecryptfs_new_file_context(struct dentry *ecryptfs_dentry) |
994 | { | |
237fead6 MH |
995 | struct ecryptfs_crypt_stat *crypt_stat = |
996 | &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; | |
997 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = | |
998 | &ecryptfs_superblock_to_private( | |
999 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
1000 | int cipher_name_len; | |
f4aad16a | 1001 | int rc = 0; |
237fead6 MH |
1002 | |
1003 | ecryptfs_set_default_crypt_stat_vals(crypt_stat, mount_crypt_stat); | |
af655dc6 | 1004 | crypt_stat->flags |= (ECRYPTFS_ENCRYPTED | ECRYPTFS_KEY_VALID); |
f4aad16a MH |
1005 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
1006 | mount_crypt_stat); | |
1007 | rc = ecryptfs_copy_mount_wide_sigs_to_inode_sigs(crypt_stat, | |
1008 | mount_crypt_stat); | |
1009 | if (rc) { | |
1010 | printk(KERN_ERR "Error attempting to copy mount-wide key sigs " | |
1011 | "to the inode key sigs; rc = [%d]\n", rc); | |
1012 | goto out; | |
1013 | } | |
1014 | cipher_name_len = | |
1015 | strlen(mount_crypt_stat->global_default_cipher_name); | |
1016 | memcpy(crypt_stat->cipher, | |
1017 | mount_crypt_stat->global_default_cipher_name, | |
1018 | cipher_name_len); | |
1019 | crypt_stat->cipher[cipher_name_len] = '\0'; | |
1020 | crypt_stat->key_size = | |
1021 | mount_crypt_stat->global_default_cipher_key_size; | |
1022 | ecryptfs_generate_new_key(crypt_stat); | |
237fead6 MH |
1023 | rc = ecryptfs_init_crypt_ctx(crypt_stat); |
1024 | if (rc) | |
1025 | ecryptfs_printk(KERN_ERR, "Error initializing cryptographic " | |
1026 | "context for cipher [%s]: rc = [%d]\n", | |
1027 | crypt_stat->cipher, rc); | |
f4aad16a | 1028 | out: |
237fead6 MH |
1029 | return rc; |
1030 | } | |
1031 | ||
1032 | /** | |
1033 | * contains_ecryptfs_marker - check for the ecryptfs marker | |
1034 | * @data: The data block in which to check | |
1035 | * | |
1036 | * Returns one if marker found; zero if not found | |
1037 | */ | |
dd2a3b7a | 1038 | static int contains_ecryptfs_marker(char *data) |
237fead6 MH |
1039 | { |
1040 | u32 m_1, m_2; | |
1041 | ||
29335c6a HH |
1042 | m_1 = get_unaligned_be32(data); |
1043 | m_2 = get_unaligned_be32(data + 4); | |
237fead6 MH |
1044 | if ((m_1 ^ MAGIC_ECRYPTFS_MARKER) == m_2) |
1045 | return 1; | |
1046 | ecryptfs_printk(KERN_DEBUG, "m_1 = [0x%.8x]; m_2 = [0x%.8x]; " | |
1047 | "MAGIC_ECRYPTFS_MARKER = [0x%.8x]\n", m_1, m_2, | |
1048 | MAGIC_ECRYPTFS_MARKER); | |
1049 | ecryptfs_printk(KERN_DEBUG, "(m_1 ^ MAGIC_ECRYPTFS_MARKER) = " | |
1050 | "[0x%.8x]\n", (m_1 ^ MAGIC_ECRYPTFS_MARKER)); | |
1051 | return 0; | |
1052 | } | |
1053 | ||
1054 | struct ecryptfs_flag_map_elem { | |
1055 | u32 file_flag; | |
1056 | u32 local_flag; | |
1057 | }; | |
1058 | ||
1059 | /* Add support for additional flags by adding elements here. */ | |
1060 | static struct ecryptfs_flag_map_elem ecryptfs_flag_map[] = { | |
1061 | {0x00000001, ECRYPTFS_ENABLE_HMAC}, | |
dd2a3b7a MH |
1062 | {0x00000002, ECRYPTFS_ENCRYPTED}, |
1063 | {0x00000004, ECRYPTFS_METADATA_IN_XATTR} | |
237fead6 MH |
1064 | }; |
1065 | ||
1066 | /** | |
1067 | * ecryptfs_process_flags | |
22e78faf | 1068 | * @crypt_stat: The cryptographic context |
237fead6 MH |
1069 | * @page_virt: Source data to be parsed |
1070 | * @bytes_read: Updated with the number of bytes read | |
1071 | * | |
1072 | * Returns zero on success; non-zero if the flag set is invalid | |
1073 | */ | |
1074 | static int ecryptfs_process_flags(struct ecryptfs_crypt_stat *crypt_stat, | |
1075 | char *page_virt, int *bytes_read) | |
1076 | { | |
1077 | int rc = 0; | |
1078 | int i; | |
1079 | u32 flags; | |
1080 | ||
29335c6a | 1081 | flags = get_unaligned_be32(page_virt); |
237fead6 MH |
1082 | for (i = 0; i < ((sizeof(ecryptfs_flag_map) |
1083 | / sizeof(struct ecryptfs_flag_map_elem))); i++) | |
1084 | if (flags & ecryptfs_flag_map[i].file_flag) { | |
e2bd99ec | 1085 | crypt_stat->flags |= ecryptfs_flag_map[i].local_flag; |
237fead6 | 1086 | } else |
e2bd99ec | 1087 | crypt_stat->flags &= ~(ecryptfs_flag_map[i].local_flag); |
237fead6 MH |
1088 | /* Version is in top 8 bits of the 32-bit flag vector */ |
1089 | crypt_stat->file_version = ((flags >> 24) & 0xFF); | |
1090 | (*bytes_read) = 4; | |
1091 | return rc; | |
1092 | } | |
1093 | ||
1094 | /** | |
1095 | * write_ecryptfs_marker | |
1096 | * @page_virt: The pointer to in a page to begin writing the marker | |
1097 | * @written: Number of bytes written | |
1098 | * | |
1099 | * Marker = 0x3c81b7f5 | |
1100 | */ | |
1101 | static void write_ecryptfs_marker(char *page_virt, size_t *written) | |
1102 | { | |
1103 | u32 m_1, m_2; | |
1104 | ||
1105 | get_random_bytes(&m_1, (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); | |
1106 | m_2 = (m_1 ^ MAGIC_ECRYPTFS_MARKER); | |
29335c6a HH |
1107 | put_unaligned_be32(m_1, page_virt); |
1108 | page_virt += (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2); | |
1109 | put_unaligned_be32(m_2, page_virt); | |
237fead6 MH |
1110 | (*written) = MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; |
1111 | } | |
1112 | ||
1113 | static void | |
1114 | write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat, | |
1115 | size_t *written) | |
1116 | { | |
1117 | u32 flags = 0; | |
1118 | int i; | |
1119 | ||
1120 | for (i = 0; i < ((sizeof(ecryptfs_flag_map) | |
1121 | / sizeof(struct ecryptfs_flag_map_elem))); i++) | |
e2bd99ec | 1122 | if (crypt_stat->flags & ecryptfs_flag_map[i].local_flag) |
237fead6 MH |
1123 | flags |= ecryptfs_flag_map[i].file_flag; |
1124 | /* Version is in top 8 bits of the 32-bit flag vector */ | |
1125 | flags |= ((((u8)crypt_stat->file_version) << 24) & 0xFF000000); | |
29335c6a | 1126 | put_unaligned_be32(flags, page_virt); |
237fead6 MH |
1127 | (*written) = 4; |
1128 | } | |
1129 | ||
1130 | struct ecryptfs_cipher_code_str_map_elem { | |
1131 | char cipher_str[16]; | |
19e66a67 | 1132 | u8 cipher_code; |
237fead6 MH |
1133 | }; |
1134 | ||
1135 | /* Add support for additional ciphers by adding elements here. The | |
1136 | * cipher_code is whatever OpenPGP applicatoins use to identify the | |
1137 | * ciphers. List in order of probability. */ | |
1138 | static struct ecryptfs_cipher_code_str_map_elem | |
1139 | ecryptfs_cipher_code_str_map[] = { | |
1140 | {"aes",RFC2440_CIPHER_AES_128 }, | |
1141 | {"blowfish", RFC2440_CIPHER_BLOWFISH}, | |
1142 | {"des3_ede", RFC2440_CIPHER_DES3_EDE}, | |
1143 | {"cast5", RFC2440_CIPHER_CAST_5}, | |
1144 | {"twofish", RFC2440_CIPHER_TWOFISH}, | |
1145 | {"cast6", RFC2440_CIPHER_CAST_6}, | |
1146 | {"aes", RFC2440_CIPHER_AES_192}, | |
1147 | {"aes", RFC2440_CIPHER_AES_256} | |
1148 | }; | |
1149 | ||
1150 | /** | |
1151 | * ecryptfs_code_for_cipher_string | |
22e78faf | 1152 | * @crypt_stat: The cryptographic context |
237fead6 MH |
1153 | * |
1154 | * Returns zero on no match, or the cipher code on match | |
1155 | */ | |
19e66a67 | 1156 | u8 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat) |
237fead6 MH |
1157 | { |
1158 | int i; | |
19e66a67 | 1159 | u8 code = 0; |
237fead6 MH |
1160 | struct ecryptfs_cipher_code_str_map_elem *map = |
1161 | ecryptfs_cipher_code_str_map; | |
1162 | ||
1163 | if (strcmp(crypt_stat->cipher, "aes") == 0) { | |
1164 | switch (crypt_stat->key_size) { | |
1165 | case 16: | |
1166 | code = RFC2440_CIPHER_AES_128; | |
1167 | break; | |
1168 | case 24: | |
1169 | code = RFC2440_CIPHER_AES_192; | |
1170 | break; | |
1171 | case 32: | |
1172 | code = RFC2440_CIPHER_AES_256; | |
1173 | } | |
1174 | } else { | |
1175 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++) | |
1176 | if (strcmp(crypt_stat->cipher, map[i].cipher_str) == 0){ | |
1177 | code = map[i].cipher_code; | |
1178 | break; | |
1179 | } | |
1180 | } | |
1181 | return code; | |
1182 | } | |
1183 | ||
1184 | /** | |
1185 | * ecryptfs_cipher_code_to_string | |
1186 | * @str: Destination to write out the cipher name | |
1187 | * @cipher_code: The code to convert to cipher name string | |
1188 | * | |
1189 | * Returns zero on success | |
1190 | */ | |
19e66a67 | 1191 | int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code) |
237fead6 MH |
1192 | { |
1193 | int rc = 0; | |
1194 | int i; | |
1195 | ||
1196 | str[0] = '\0'; | |
1197 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++) | |
1198 | if (cipher_code == ecryptfs_cipher_code_str_map[i].cipher_code) | |
1199 | strcpy(str, ecryptfs_cipher_code_str_map[i].cipher_str); | |
1200 | if (str[0] == '\0') { | |
1201 | ecryptfs_printk(KERN_WARNING, "Cipher code not recognized: " | |
1202 | "[%d]\n", cipher_code); | |
1203 | rc = -EINVAL; | |
1204 | } | |
1205 | return rc; | |
1206 | } | |
1207 | ||
d7cdc5fe MH |
1208 | int ecryptfs_read_and_validate_header_region(char *data, |
1209 | struct inode *ecryptfs_inode) | |
dd2a3b7a | 1210 | { |
d7cdc5fe MH |
1211 | struct ecryptfs_crypt_stat *crypt_stat = |
1212 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); | |
dd2a3b7a MH |
1213 | int rc; |
1214 | ||
d7cdc5fe MH |
1215 | rc = ecryptfs_read_lower(data, 0, crypt_stat->extent_size, |
1216 | ecryptfs_inode); | |
1217 | if (rc) { | |
1218 | printk(KERN_ERR "%s: Error reading header region; rc = [%d]\n", | |
18d1dbf1 | 1219 | __func__, rc); |
dd2a3b7a | 1220 | goto out; |
d7cdc5fe MH |
1221 | } |
1222 | if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) { | |
dd2a3b7a | 1223 | rc = -EINVAL; |
d7cdc5fe MH |
1224 | ecryptfs_printk(KERN_DEBUG, "Valid marker not found\n"); |
1225 | } | |
dd2a3b7a MH |
1226 | out: |
1227 | return rc; | |
1228 | } | |
1229 | ||
e77a56dd MH |
1230 | void |
1231 | ecryptfs_write_header_metadata(char *virt, | |
1232 | struct ecryptfs_crypt_stat *crypt_stat, | |
1233 | size_t *written) | |
237fead6 MH |
1234 | { |
1235 | u32 header_extent_size; | |
1236 | u16 num_header_extents_at_front; | |
1237 | ||
45eaab79 | 1238 | header_extent_size = (u32)crypt_stat->extent_size; |
237fead6 | 1239 | num_header_extents_at_front = |
cc11beff MH |
1240 | (u16)(crypt_stat->num_header_bytes_at_front |
1241 | / crypt_stat->extent_size); | |
29335c6a | 1242 | put_unaligned_be32(header_extent_size, virt); |
237fead6 | 1243 | virt += 4; |
29335c6a | 1244 | put_unaligned_be16(num_header_extents_at_front, virt); |
237fead6 MH |
1245 | (*written) = 6; |
1246 | } | |
1247 | ||
237fead6 MH |
1248 | struct kmem_cache *ecryptfs_header_cache_1; |
1249 | struct kmem_cache *ecryptfs_header_cache_2; | |
1250 | ||
1251 | /** | |
1252 | * ecryptfs_write_headers_virt | |
22e78faf | 1253 | * @page_virt: The virtual address to write the headers to |
87b811c3 | 1254 | * @max: The size of memory allocated at page_virt |
22e78faf MH |
1255 | * @size: Set to the number of bytes written by this function |
1256 | * @crypt_stat: The cryptographic context | |
1257 | * @ecryptfs_dentry: The eCryptfs dentry | |
237fead6 MH |
1258 | * |
1259 | * Format version: 1 | |
1260 | * | |
1261 | * Header Extent: | |
1262 | * Octets 0-7: Unencrypted file size (big-endian) | |
1263 | * Octets 8-15: eCryptfs special marker | |
1264 | * Octets 16-19: Flags | |
1265 | * Octet 16: File format version number (between 0 and 255) | |
1266 | * Octets 17-18: Reserved | |
1267 | * Octet 19: Bit 1 (lsb): Reserved | |
1268 | * Bit 2: Encrypted? | |
1269 | * Bits 3-8: Reserved | |
1270 | * Octets 20-23: Header extent size (big-endian) | |
1271 | * Octets 24-25: Number of header extents at front of file | |
1272 | * (big-endian) | |
1273 | * Octet 26: Begin RFC 2440 authentication token packet set | |
1274 | * Data Extent 0: | |
1275 | * Lower data (CBC encrypted) | |
1276 | * Data Extent 1: | |
1277 | * Lower data (CBC encrypted) | |
1278 | * ... | |
1279 | * | |
1280 | * Returns zero on success | |
1281 | */ | |
87b811c3 ES |
1282 | static int ecryptfs_write_headers_virt(char *page_virt, size_t max, |
1283 | size_t *size, | |
dd2a3b7a MH |
1284 | struct ecryptfs_crypt_stat *crypt_stat, |
1285 | struct dentry *ecryptfs_dentry) | |
237fead6 MH |
1286 | { |
1287 | int rc; | |
1288 | size_t written; | |
1289 | size_t offset; | |
1290 | ||
1291 | offset = ECRYPTFS_FILE_SIZE_BYTES; | |
1292 | write_ecryptfs_marker((page_virt + offset), &written); | |
1293 | offset += written; | |
1294 | write_ecryptfs_flags((page_virt + offset), crypt_stat, &written); | |
1295 | offset += written; | |
e77a56dd MH |
1296 | ecryptfs_write_header_metadata((page_virt + offset), crypt_stat, |
1297 | &written); | |
237fead6 MH |
1298 | offset += written; |
1299 | rc = ecryptfs_generate_key_packet_set((page_virt + offset), crypt_stat, | |
1300 | ecryptfs_dentry, &written, | |
87b811c3 | 1301 | max - offset); |
237fead6 MH |
1302 | if (rc) |
1303 | ecryptfs_printk(KERN_WARNING, "Error generating key packet " | |
1304 | "set; rc = [%d]\n", rc); | |
dd2a3b7a MH |
1305 | if (size) { |
1306 | offset += written; | |
1307 | *size = offset; | |
1308 | } | |
1309 | return rc; | |
1310 | } | |
1311 | ||
22e78faf MH |
1312 | static int |
1313 | ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat, | |
d7cdc5fe | 1314 | struct dentry *ecryptfs_dentry, |
cc11beff | 1315 | char *virt) |
dd2a3b7a | 1316 | { |
d7cdc5fe | 1317 | int rc; |
dd2a3b7a | 1318 | |
cc11beff MH |
1319 | rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, virt, |
1320 | 0, crypt_stat->num_header_bytes_at_front); | |
1321 | if (rc) | |
d7cdc5fe | 1322 | printk(KERN_ERR "%s: Error attempting to write header " |
18d1dbf1 | 1323 | "information to lower file; rc = [%d]\n", __func__, |
d7cdc5fe | 1324 | rc); |
70456600 | 1325 | return rc; |
dd2a3b7a MH |
1326 | } |
1327 | ||
22e78faf MH |
1328 | static int |
1329 | ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, | |
1330 | struct ecryptfs_crypt_stat *crypt_stat, | |
1331 | char *page_virt, size_t size) | |
dd2a3b7a MH |
1332 | { |
1333 | int rc; | |
1334 | ||
1335 | rc = ecryptfs_setxattr(ecryptfs_dentry, ECRYPTFS_XATTR_NAME, page_virt, | |
1336 | size, 0); | |
237fead6 MH |
1337 | return rc; |
1338 | } | |
1339 | ||
1340 | /** | |
dd2a3b7a | 1341 | * ecryptfs_write_metadata |
22e78faf | 1342 | * @ecryptfs_dentry: The eCryptfs dentry |
237fead6 MH |
1343 | * |
1344 | * Write the file headers out. This will likely involve a userspace | |
1345 | * callout, in which the session key is encrypted with one or more | |
1346 | * public keys and/or the passphrase necessary to do the encryption is | |
1347 | * retrieved via a prompt. Exactly what happens at this point should | |
1348 | * be policy-dependent. | |
1349 | * | |
1350 | * Returns zero on success; non-zero on error | |
1351 | */ | |
d7cdc5fe | 1352 | int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry) |
237fead6 | 1353 | { |
d7cdc5fe MH |
1354 | struct ecryptfs_crypt_stat *crypt_stat = |
1355 | &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; | |
cc11beff | 1356 | char *virt; |
d7cdc5fe | 1357 | size_t size = 0; |
237fead6 MH |
1358 | int rc = 0; |
1359 | ||
e2bd99ec MH |
1360 | if (likely(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
1361 | if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { | |
d7cdc5fe | 1362 | printk(KERN_ERR "Key is invalid; bailing out\n"); |
237fead6 MH |
1363 | rc = -EINVAL; |
1364 | goto out; | |
1365 | } | |
1366 | } else { | |
cc11beff | 1367 | printk(KERN_WARNING "%s: Encrypted flag not set\n", |
18d1dbf1 | 1368 | __func__); |
237fead6 | 1369 | rc = -EINVAL; |
237fead6 MH |
1370 | goto out; |
1371 | } | |
1372 | /* Released in this function */ | |
87b811c3 | 1373 | virt = (char *)get_zeroed_page(GFP_KERNEL); |
cc11beff | 1374 | if (!virt) { |
18d1dbf1 | 1375 | printk(KERN_ERR "%s: Out of memory\n", __func__); |
237fead6 MH |
1376 | rc = -ENOMEM; |
1377 | goto out; | |
1378 | } | |
87b811c3 ES |
1379 | rc = ecryptfs_write_headers_virt(virt, PAGE_CACHE_SIZE, &size, |
1380 | crypt_stat, ecryptfs_dentry); | |
237fead6 | 1381 | if (unlikely(rc)) { |
cc11beff | 1382 | printk(KERN_ERR "%s: Error whilst writing headers; rc = [%d]\n", |
18d1dbf1 | 1383 | __func__, rc); |
237fead6 MH |
1384 | goto out_free; |
1385 | } | |
dd2a3b7a MH |
1386 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
1387 | rc = ecryptfs_write_metadata_to_xattr(ecryptfs_dentry, | |
cc11beff | 1388 | crypt_stat, virt, size); |
dd2a3b7a | 1389 | else |
d7cdc5fe | 1390 | rc = ecryptfs_write_metadata_to_contents(crypt_stat, |
cc11beff | 1391 | ecryptfs_dentry, virt); |
dd2a3b7a | 1392 | if (rc) { |
cc11beff | 1393 | printk(KERN_ERR "%s: Error writing metadata out to lower file; " |
18d1dbf1 | 1394 | "rc = [%d]\n", __func__, rc); |
dd2a3b7a | 1395 | goto out_free; |
237fead6 | 1396 | } |
237fead6 | 1397 | out_free: |
87b811c3 | 1398 | free_page((unsigned long)virt); |
237fead6 MH |
1399 | out: |
1400 | return rc; | |
1401 | } | |
1402 | ||
dd2a3b7a MH |
1403 | #define ECRYPTFS_DONT_VALIDATE_HEADER_SIZE 0 |
1404 | #define ECRYPTFS_VALIDATE_HEADER_SIZE 1 | |
237fead6 | 1405 | static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat, |
dd2a3b7a MH |
1406 | char *virt, int *bytes_read, |
1407 | int validate_header_size) | |
237fead6 MH |
1408 | { |
1409 | int rc = 0; | |
1410 | u32 header_extent_size; | |
1411 | u16 num_header_extents_at_front; | |
1412 | ||
29335c6a HH |
1413 | header_extent_size = get_unaligned_be32(virt); |
1414 | virt += sizeof(__be32); | |
1415 | num_header_extents_at_front = get_unaligned_be16(virt); | |
cc11beff MH |
1416 | crypt_stat->num_header_bytes_at_front = |
1417 | (((size_t)num_header_extents_at_front | |
1418 | * (size_t)header_extent_size)); | |
29335c6a | 1419 | (*bytes_read) = (sizeof(__be32) + sizeof(__be16)); |
dd2a3b7a | 1420 | if ((validate_header_size == ECRYPTFS_VALIDATE_HEADER_SIZE) |
cc11beff | 1421 | && (crypt_stat->num_header_bytes_at_front |
dd2a3b7a | 1422 | < ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)) { |
237fead6 | 1423 | rc = -EINVAL; |
cc11beff MH |
1424 | printk(KERN_WARNING "Invalid header size: [%zd]\n", |
1425 | crypt_stat->num_header_bytes_at_front); | |
237fead6 MH |
1426 | } |
1427 | return rc; | |
1428 | } | |
1429 | ||
1430 | /** | |
1431 | * set_default_header_data | |
22e78faf | 1432 | * @crypt_stat: The cryptographic context |
237fead6 MH |
1433 | * |
1434 | * For version 0 file format; this function is only for backwards | |
1435 | * compatibility for files created with the prior versions of | |
1436 | * eCryptfs. | |
1437 | */ | |
1438 | static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat) | |
1439 | { | |
cc11beff MH |
1440 | crypt_stat->num_header_bytes_at_front = |
1441 | ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; | |
237fead6 MH |
1442 | } |
1443 | ||
1444 | /** | |
1445 | * ecryptfs_read_headers_virt | |
22e78faf MH |
1446 | * @page_virt: The virtual address into which to read the headers |
1447 | * @crypt_stat: The cryptographic context | |
1448 | * @ecryptfs_dentry: The eCryptfs dentry | |
1449 | * @validate_header_size: Whether to validate the header size while reading | |
237fead6 MH |
1450 | * |
1451 | * Read/parse the header data. The header format is detailed in the | |
1452 | * comment block for the ecryptfs_write_headers_virt() function. | |
1453 | * | |
1454 | * Returns zero on success | |
1455 | */ | |
1456 | static int ecryptfs_read_headers_virt(char *page_virt, | |
1457 | struct ecryptfs_crypt_stat *crypt_stat, | |
dd2a3b7a MH |
1458 | struct dentry *ecryptfs_dentry, |
1459 | int validate_header_size) | |
237fead6 MH |
1460 | { |
1461 | int rc = 0; | |
1462 | int offset; | |
1463 | int bytes_read; | |
1464 | ||
1465 | ecryptfs_set_default_sizes(crypt_stat); | |
1466 | crypt_stat->mount_crypt_stat = &ecryptfs_superblock_to_private( | |
1467 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
1468 | offset = ECRYPTFS_FILE_SIZE_BYTES; | |
1469 | rc = contains_ecryptfs_marker(page_virt + offset); | |
1470 | if (rc == 0) { | |
1471 | rc = -EINVAL; | |
1472 | goto out; | |
1473 | } | |
1474 | offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; | |
1475 | rc = ecryptfs_process_flags(crypt_stat, (page_virt + offset), | |
1476 | &bytes_read); | |
1477 | if (rc) { | |
1478 | ecryptfs_printk(KERN_WARNING, "Error processing flags\n"); | |
1479 | goto out; | |
1480 | } | |
1481 | if (crypt_stat->file_version > ECRYPTFS_SUPPORTED_FILE_VERSION) { | |
1482 | ecryptfs_printk(KERN_WARNING, "File version is [%d]; only " | |
1483 | "file version [%d] is supported by this " | |
1484 | "version of eCryptfs\n", | |
1485 | crypt_stat->file_version, | |
1486 | ECRYPTFS_SUPPORTED_FILE_VERSION); | |
1487 | rc = -EINVAL; | |
1488 | goto out; | |
1489 | } | |
1490 | offset += bytes_read; | |
1491 | if (crypt_stat->file_version >= 1) { | |
1492 | rc = parse_header_metadata(crypt_stat, (page_virt + offset), | |
dd2a3b7a | 1493 | &bytes_read, validate_header_size); |
237fead6 MH |
1494 | if (rc) { |
1495 | ecryptfs_printk(KERN_WARNING, "Error reading header " | |
1496 | "metadata; rc = [%d]\n", rc); | |
1497 | } | |
1498 | offset += bytes_read; | |
1499 | } else | |
1500 | set_default_header_data(crypt_stat); | |
1501 | rc = ecryptfs_parse_packet_set(crypt_stat, (page_virt + offset), | |
1502 | ecryptfs_dentry); | |
1503 | out: | |
1504 | return rc; | |
1505 | } | |
1506 | ||
1507 | /** | |
dd2a3b7a | 1508 | * ecryptfs_read_xattr_region |
22e78faf | 1509 | * @page_virt: The vitual address into which to read the xattr data |
2ed92554 | 1510 | * @ecryptfs_inode: The eCryptfs inode |
dd2a3b7a MH |
1511 | * |
1512 | * Attempts to read the crypto metadata from the extended attribute | |
1513 | * region of the lower file. | |
22e78faf MH |
1514 | * |
1515 | * Returns zero on success; non-zero on error | |
dd2a3b7a | 1516 | */ |
d7cdc5fe | 1517 | int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode) |
dd2a3b7a | 1518 | { |
d7cdc5fe MH |
1519 | struct dentry *lower_dentry = |
1520 | ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry; | |
dd2a3b7a MH |
1521 | ssize_t size; |
1522 | int rc = 0; | |
1523 | ||
d7cdc5fe MH |
1524 | size = ecryptfs_getxattr_lower(lower_dentry, ECRYPTFS_XATTR_NAME, |
1525 | page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE); | |
dd2a3b7a | 1526 | if (size < 0) { |
25bd8174 MH |
1527 | if (unlikely(ecryptfs_verbosity > 0)) |
1528 | printk(KERN_INFO "Error attempting to read the [%s] " | |
1529 | "xattr from the lower file; return value = " | |
1530 | "[%zd]\n", ECRYPTFS_XATTR_NAME, size); | |
dd2a3b7a MH |
1531 | rc = -EINVAL; |
1532 | goto out; | |
1533 | } | |
1534 | out: | |
1535 | return rc; | |
1536 | } | |
1537 | ||
1538 | int ecryptfs_read_and_validate_xattr_region(char *page_virt, | |
1539 | struct dentry *ecryptfs_dentry) | |
1540 | { | |
1541 | int rc; | |
1542 | ||
d7cdc5fe | 1543 | rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry->d_inode); |
dd2a3b7a MH |
1544 | if (rc) |
1545 | goto out; | |
1546 | if (!contains_ecryptfs_marker(page_virt + ECRYPTFS_FILE_SIZE_BYTES)) { | |
1547 | printk(KERN_WARNING "Valid data found in [%s] xattr, but " | |
1548 | "the marker is invalid\n", ECRYPTFS_XATTR_NAME); | |
1549 | rc = -EINVAL; | |
1550 | } | |
1551 | out: | |
1552 | return rc; | |
1553 | } | |
1554 | ||
1555 | /** | |
1556 | * ecryptfs_read_metadata | |
1557 | * | |
1558 | * Common entry point for reading file metadata. From here, we could | |
1559 | * retrieve the header information from the header region of the file, | |
1560 | * the xattr region of the file, or some other repostory that is | |
1561 | * stored separately from the file itself. The current implementation | |
1562 | * supports retrieving the metadata information from the file contents | |
1563 | * and from the xattr region. | |
237fead6 MH |
1564 | * |
1565 | * Returns zero if valid headers found and parsed; non-zero otherwise | |
1566 | */ | |
d7cdc5fe | 1567 | int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry) |
237fead6 MH |
1568 | { |
1569 | int rc = 0; | |
1570 | char *page_virt = NULL; | |
d7cdc5fe | 1571 | struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode; |
237fead6 | 1572 | struct ecryptfs_crypt_stat *crypt_stat = |
d7cdc5fe | 1573 | &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
e77a56dd MH |
1574 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
1575 | &ecryptfs_superblock_to_private( | |
1576 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
237fead6 | 1577 | |
e77a56dd MH |
1578 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
1579 | mount_crypt_stat); | |
237fead6 | 1580 | /* Read the first page from the underlying file */ |
f7267c0c | 1581 | page_virt = kmem_cache_alloc(ecryptfs_header_cache_1, GFP_USER); |
237fead6 MH |
1582 | if (!page_virt) { |
1583 | rc = -ENOMEM; | |
d7cdc5fe | 1584 | printk(KERN_ERR "%s: Unable to allocate page_virt\n", |
18d1dbf1 | 1585 | __func__); |
237fead6 MH |
1586 | goto out; |
1587 | } | |
d7cdc5fe MH |
1588 | rc = ecryptfs_read_lower(page_virt, 0, crypt_stat->extent_size, |
1589 | ecryptfs_inode); | |
1590 | if (!rc) | |
1591 | rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, | |
1592 | ecryptfs_dentry, | |
1593 | ECRYPTFS_VALIDATE_HEADER_SIZE); | |
237fead6 | 1594 | if (rc) { |
d7cdc5fe | 1595 | rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode); |
dd2a3b7a MH |
1596 | if (rc) { |
1597 | printk(KERN_DEBUG "Valid eCryptfs headers not found in " | |
1598 | "file header region or xattr region\n"); | |
1599 | rc = -EINVAL; | |
1600 | goto out; | |
1601 | } | |
1602 | rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, | |
1603 | ecryptfs_dentry, | |
1604 | ECRYPTFS_DONT_VALIDATE_HEADER_SIZE); | |
1605 | if (rc) { | |
1606 | printk(KERN_DEBUG "Valid eCryptfs headers not found in " | |
1607 | "file xattr region either\n"); | |
1608 | rc = -EINVAL; | |
1609 | } | |
1610 | if (crypt_stat->mount_crypt_stat->flags | |
1611 | & ECRYPTFS_XATTR_METADATA_ENABLED) { | |
1612 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; | |
1613 | } else { | |
1614 | printk(KERN_WARNING "Attempt to access file with " | |
1615 | "crypto metadata only in the extended attribute " | |
1616 | "region, but eCryptfs was mounted without " | |
1617 | "xattr support enabled. eCryptfs will not treat " | |
1618 | "this like an encrypted file.\n"); | |
1619 | rc = -EINVAL; | |
1620 | } | |
237fead6 MH |
1621 | } |
1622 | out: | |
1623 | if (page_virt) { | |
1624 | memset(page_virt, 0, PAGE_CACHE_SIZE); | |
1625 | kmem_cache_free(ecryptfs_header_cache_1, page_virt); | |
1626 | } | |
1627 | return rc; | |
1628 | } | |
1629 | ||
1630 | /** | |
1631 | * ecryptfs_encode_filename - converts a plaintext file name to cipher text | |
1632 | * @crypt_stat: The crypt_stat struct associated with the file anem to encode | |
1633 | * @name: The plaintext name | |
1634 | * @length: The length of the plaintext | |
1635 | * @encoded_name: The encypted name | |
1636 | * | |
1637 | * Encrypts and encodes a filename into something that constitutes a | |
1638 | * valid filename for a filesystem, with printable characters. | |
1639 | * | |
1640 | * We assume that we have a properly initialized crypto context, | |
1641 | * pointed to by crypt_stat->tfm. | |
1642 | * | |
1643 | * TODO: Implement filename decoding and decryption here, in place of | |
1644 | * memcpy. We are keeping the framework around for now to (1) | |
1645 | * facilitate testing of the components needed to implement filename | |
1646 | * encryption and (2) to provide a code base from which other | |
1647 | * developers in the community can easily implement this feature. | |
1648 | * | |
1649 | * Returns the length of encoded filename; negative if error | |
1650 | */ | |
1651 | int | |
1652 | ecryptfs_encode_filename(struct ecryptfs_crypt_stat *crypt_stat, | |
1653 | const char *name, int length, char **encoded_name) | |
1654 | { | |
1655 | int error = 0; | |
1656 | ||
1657 | (*encoded_name) = kmalloc(length + 2, GFP_KERNEL); | |
1658 | if (!(*encoded_name)) { | |
1659 | error = -ENOMEM; | |
1660 | goto out; | |
1661 | } | |
1662 | /* TODO: Filename encryption is a scheduled feature for a | |
1663 | * future version of eCryptfs. This function is here only for | |
1664 | * the purpose of providing a framework for other developers | |
1665 | * to easily implement filename encryption. Hint: Replace this | |
1666 | * memcpy() with a call to encrypt and encode the | |
1667 | * filename, the set the length accordingly. */ | |
1668 | memcpy((void *)(*encoded_name), (void *)name, length); | |
1669 | (*encoded_name)[length] = '\0'; | |
1670 | error = length + 1; | |
1671 | out: | |
1672 | return error; | |
1673 | } | |
1674 | ||
1675 | /** | |
1676 | * ecryptfs_decode_filename - converts the cipher text name to plaintext | |
1677 | * @crypt_stat: The crypt_stat struct associated with the file | |
1678 | * @name: The filename in cipher text | |
1679 | * @length: The length of the cipher text name | |
1680 | * @decrypted_name: The plaintext name | |
1681 | * | |
1682 | * Decodes and decrypts the filename. | |
1683 | * | |
1684 | * We assume that we have a properly initialized crypto context, | |
1685 | * pointed to by crypt_stat->tfm. | |
1686 | * | |
1687 | * TODO: Implement filename decoding and decryption here, in place of | |
1688 | * memcpy. We are keeping the framework around for now to (1) | |
1689 | * facilitate testing of the components needed to implement filename | |
1690 | * encryption and (2) to provide a code base from which other | |
1691 | * developers in the community can easily implement this feature. | |
1692 | * | |
1693 | * Returns the length of decoded filename; negative if error | |
1694 | */ | |
1695 | int | |
1696 | ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat, | |
1697 | const char *name, int length, char **decrypted_name) | |
1698 | { | |
1699 | int error = 0; | |
1700 | ||
1701 | (*decrypted_name) = kmalloc(length + 2, GFP_KERNEL); | |
1702 | if (!(*decrypted_name)) { | |
1703 | error = -ENOMEM; | |
1704 | goto out; | |
1705 | } | |
1706 | /* TODO: Filename encryption is a scheduled feature for a | |
1707 | * future version of eCryptfs. This function is here only for | |
1708 | * the purpose of providing a framework for other developers | |
1709 | * to easily implement filename encryption. Hint: Replace this | |
1710 | * memcpy() with a call to decode and decrypt the | |
1711 | * filename, the set the length accordingly. */ | |
1712 | memcpy((void *)(*decrypted_name), (void *)name, length); | |
1713 | (*decrypted_name)[length + 1] = '\0'; /* Only for convenience | |
1714 | * in printing out the | |
1715 | * string in debug | |
1716 | * messages */ | |
1717 | error = length; | |
1718 | out: | |
1719 | return error; | |
1720 | } | |
1721 | ||
1722 | /** | |
f4aad16a | 1723 | * ecryptfs_process_key_cipher - Perform key cipher initialization. |
237fead6 | 1724 | * @key_tfm: Crypto context for key material, set by this function |
e5d9cbde MH |
1725 | * @cipher_name: Name of the cipher |
1726 | * @key_size: Size of the key in bytes | |
237fead6 MH |
1727 | * |
1728 | * Returns zero on success. Any crypto_tfm structs allocated here | |
1729 | * should be released by other functions, such as on a superblock put | |
1730 | * event, regardless of whether this function succeeds for fails. | |
1731 | */ | |
cd9d67df | 1732 | static int |
f4aad16a MH |
1733 | ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm, |
1734 | char *cipher_name, size_t *key_size) | |
237fead6 MH |
1735 | { |
1736 | char dummy_key[ECRYPTFS_MAX_KEY_BYTES]; | |
8bba066f | 1737 | char *full_alg_name; |
237fead6 MH |
1738 | int rc; |
1739 | ||
e5d9cbde MH |
1740 | *key_tfm = NULL; |
1741 | if (*key_size > ECRYPTFS_MAX_KEY_BYTES) { | |
237fead6 MH |
1742 | rc = -EINVAL; |
1743 | printk(KERN_ERR "Requested key size is [%Zd] bytes; maximum " | |
e5d9cbde | 1744 | "allowable is [%d]\n", *key_size, ECRYPTFS_MAX_KEY_BYTES); |
237fead6 MH |
1745 | goto out; |
1746 | } | |
8bba066f MH |
1747 | rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, cipher_name, |
1748 | "ecb"); | |
1749 | if (rc) | |
1750 | goto out; | |
1751 | *key_tfm = crypto_alloc_blkcipher(full_alg_name, 0, CRYPTO_ALG_ASYNC); | |
1752 | kfree(full_alg_name); | |
1753 | if (IS_ERR(*key_tfm)) { | |
1754 | rc = PTR_ERR(*key_tfm); | |
237fead6 | 1755 | printk(KERN_ERR "Unable to allocate crypto cipher with name " |
8bba066f | 1756 | "[%s]; rc = [%d]\n", cipher_name, rc); |
237fead6 MH |
1757 | goto out; |
1758 | } | |
8bba066f MH |
1759 | crypto_blkcipher_set_flags(*key_tfm, CRYPTO_TFM_REQ_WEAK_KEY); |
1760 | if (*key_size == 0) { | |
1761 | struct blkcipher_alg *alg = crypto_blkcipher_alg(*key_tfm); | |
1762 | ||
1763 | *key_size = alg->max_keysize; | |
1764 | } | |
e5d9cbde | 1765 | get_random_bytes(dummy_key, *key_size); |
8bba066f | 1766 | rc = crypto_blkcipher_setkey(*key_tfm, dummy_key, *key_size); |
237fead6 MH |
1767 | if (rc) { |
1768 | printk(KERN_ERR "Error attempting to set key of size [%Zd] for " | |
e5d9cbde | 1769 | "cipher [%s]; rc = [%d]\n", *key_size, cipher_name, rc); |
237fead6 MH |
1770 | rc = -EINVAL; |
1771 | goto out; | |
1772 | } | |
1773 | out: | |
1774 | return rc; | |
1775 | } | |
f4aad16a MH |
1776 | |
1777 | struct kmem_cache *ecryptfs_key_tfm_cache; | |
7896b631 | 1778 | static struct list_head key_tfm_list; |
af440f52 | 1779 | struct mutex key_tfm_list_mutex; |
f4aad16a MH |
1780 | |
1781 | int ecryptfs_init_crypto(void) | |
1782 | { | |
1783 | mutex_init(&key_tfm_list_mutex); | |
1784 | INIT_LIST_HEAD(&key_tfm_list); | |
1785 | return 0; | |
1786 | } | |
1787 | ||
af440f52 ES |
1788 | /** |
1789 | * ecryptfs_destroy_crypto - free all cached key_tfms on key_tfm_list | |
1790 | * | |
1791 | * Called only at module unload time | |
1792 | */ | |
fcd12835 | 1793 | int ecryptfs_destroy_crypto(void) |
f4aad16a MH |
1794 | { |
1795 | struct ecryptfs_key_tfm *key_tfm, *key_tfm_tmp; | |
1796 | ||
1797 | mutex_lock(&key_tfm_list_mutex); | |
1798 | list_for_each_entry_safe(key_tfm, key_tfm_tmp, &key_tfm_list, | |
1799 | key_tfm_list) { | |
1800 | list_del(&key_tfm->key_tfm_list); | |
1801 | if (key_tfm->key_tfm) | |
1802 | crypto_free_blkcipher(key_tfm->key_tfm); | |
1803 | kmem_cache_free(ecryptfs_key_tfm_cache, key_tfm); | |
1804 | } | |
1805 | mutex_unlock(&key_tfm_list_mutex); | |
1806 | return 0; | |
1807 | } | |
1808 | ||
1809 | int | |
1810 | ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name, | |
1811 | size_t key_size) | |
1812 | { | |
1813 | struct ecryptfs_key_tfm *tmp_tfm; | |
1814 | int rc = 0; | |
1815 | ||
af440f52 ES |
1816 | BUG_ON(!mutex_is_locked(&key_tfm_list_mutex)); |
1817 | ||
f4aad16a MH |
1818 | tmp_tfm = kmem_cache_alloc(ecryptfs_key_tfm_cache, GFP_KERNEL); |
1819 | if (key_tfm != NULL) | |
1820 | (*key_tfm) = tmp_tfm; | |
1821 | if (!tmp_tfm) { | |
1822 | rc = -ENOMEM; | |
1823 | printk(KERN_ERR "Error attempting to allocate from " | |
1824 | "ecryptfs_key_tfm_cache\n"); | |
1825 | goto out; | |
1826 | } | |
1827 | mutex_init(&tmp_tfm->key_tfm_mutex); | |
1828 | strncpy(tmp_tfm->cipher_name, cipher_name, | |
1829 | ECRYPTFS_MAX_CIPHER_NAME_SIZE); | |
b8862906 | 1830 | tmp_tfm->cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; |
f4aad16a | 1831 | tmp_tfm->key_size = key_size; |
5dda6992 MH |
1832 | rc = ecryptfs_process_key_cipher(&tmp_tfm->key_tfm, |
1833 | tmp_tfm->cipher_name, | |
1834 | &tmp_tfm->key_size); | |
1835 | if (rc) { | |
f4aad16a MH |
1836 | printk(KERN_ERR "Error attempting to initialize key TFM " |
1837 | "cipher with name = [%s]; rc = [%d]\n", | |
1838 | tmp_tfm->cipher_name, rc); | |
1839 | kmem_cache_free(ecryptfs_key_tfm_cache, tmp_tfm); | |
1840 | if (key_tfm != NULL) | |
1841 | (*key_tfm) = NULL; | |
1842 | goto out; | |
1843 | } | |
f4aad16a | 1844 | list_add(&tmp_tfm->key_tfm_list, &key_tfm_list); |
f4aad16a MH |
1845 | out: |
1846 | return rc; | |
1847 | } | |
1848 | ||
af440f52 ES |
1849 | /** |
1850 | * ecryptfs_tfm_exists - Search for existing tfm for cipher_name. | |
1851 | * @cipher_name: the name of the cipher to search for | |
1852 | * @key_tfm: set to corresponding tfm if found | |
1853 | * | |
1854 | * Searches for cached key_tfm matching @cipher_name | |
1855 | * Must be called with &key_tfm_list_mutex held | |
1856 | * Returns 1 if found, with @key_tfm set | |
1857 | * Returns 0 if not found, with @key_tfm set to NULL | |
1858 | */ | |
1859 | int ecryptfs_tfm_exists(char *cipher_name, struct ecryptfs_key_tfm **key_tfm) | |
1860 | { | |
1861 | struct ecryptfs_key_tfm *tmp_key_tfm; | |
1862 | ||
1863 | BUG_ON(!mutex_is_locked(&key_tfm_list_mutex)); | |
1864 | ||
1865 | list_for_each_entry(tmp_key_tfm, &key_tfm_list, key_tfm_list) { | |
1866 | if (strcmp(tmp_key_tfm->cipher_name, cipher_name) == 0) { | |
1867 | if (key_tfm) | |
1868 | (*key_tfm) = tmp_key_tfm; | |
1869 | return 1; | |
1870 | } | |
1871 | } | |
1872 | if (key_tfm) | |
1873 | (*key_tfm) = NULL; | |
1874 | return 0; | |
1875 | } | |
1876 | ||
1877 | /** | |
1878 | * ecryptfs_get_tfm_and_mutex_for_cipher_name | |
1879 | * | |
1880 | * @tfm: set to cached tfm found, or new tfm created | |
1881 | * @tfm_mutex: set to mutex for cached tfm found, or new tfm created | |
1882 | * @cipher_name: the name of the cipher to search for and/or add | |
1883 | * | |
1884 | * Sets pointers to @tfm & @tfm_mutex matching @cipher_name. | |
1885 | * Searches for cached item first, and creates new if not found. | |
1886 | * Returns 0 on success, non-zero if adding new cipher failed | |
1887 | */ | |
f4aad16a MH |
1888 | int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm, |
1889 | struct mutex **tfm_mutex, | |
1890 | char *cipher_name) | |
1891 | { | |
1892 | struct ecryptfs_key_tfm *key_tfm; | |
1893 | int rc = 0; | |
1894 | ||
1895 | (*tfm) = NULL; | |
1896 | (*tfm_mutex) = NULL; | |
af440f52 | 1897 | |
f4aad16a | 1898 | mutex_lock(&key_tfm_list_mutex); |
af440f52 ES |
1899 | if (!ecryptfs_tfm_exists(cipher_name, &key_tfm)) { |
1900 | rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0); | |
1901 | if (rc) { | |
1902 | printk(KERN_ERR "Error adding new key_tfm to list; " | |
1903 | "rc = [%d]\n", rc); | |
f4aad16a MH |
1904 | goto out; |
1905 | } | |
1906 | } | |
f4aad16a MH |
1907 | (*tfm) = key_tfm->key_tfm; |
1908 | (*tfm_mutex) = &key_tfm->key_tfm_mutex; | |
1909 | out: | |
71fd5179 | 1910 | mutex_unlock(&key_tfm_list_mutex); |
f4aad16a MH |
1911 | return rc; |
1912 | } |