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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 | ||
8bba066f MH |
126 | int ecryptfs_crypto_api_algify_cipher_name(char **algified_name, |
127 | char *cipher_name, | |
128 | char *chaining_modifier) | |
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 | |
152 | * @offset: Offset of the page whose's iv we are to derive | |
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, | |
160 | pgoff_t offset) | |
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); | |
176 | snprintf((src + crypt_stat->iv_bytes), 16, "%ld", offset); | |
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 | ||
282 | while (size > 0 && i < sg_size) { | |
283 | pg = virt_to_page(addr); | |
284 | offset = offset_in_page(addr); | |
285 | if (sg) { | |
286 | sg[i].page = pg; | |
287 | sg[i].offset = offset; | |
288 | } | |
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 | ||
356 | static void | |
357 | ecryptfs_extent_to_lwr_pg_idx_and_offset(unsigned long *lower_page_idx, | |
358 | int *byte_offset, | |
359 | struct ecryptfs_crypt_stat *crypt_stat, | |
360 | unsigned long extent_num) | |
361 | { | |
362 | unsigned long lower_extent_num; | |
363 | int extents_occupied_by_headers_at_front; | |
364 | int bytes_occupied_by_headers_at_front; | |
365 | int extent_offset; | |
366 | int extents_per_page; | |
367 | ||
368 | bytes_occupied_by_headers_at_front = | |
369 | ( crypt_stat->header_extent_size | |
370 | * crypt_stat->num_header_extents_at_front ); | |
371 | extents_occupied_by_headers_at_front = | |
372 | ( bytes_occupied_by_headers_at_front | |
373 | / crypt_stat->extent_size ); | |
374 | lower_extent_num = extents_occupied_by_headers_at_front + extent_num; | |
375 | extents_per_page = PAGE_CACHE_SIZE / crypt_stat->extent_size; | |
376 | (*lower_page_idx) = lower_extent_num / extents_per_page; | |
377 | extent_offset = lower_extent_num % extents_per_page; | |
378 | (*byte_offset) = extent_offset * crypt_stat->extent_size; | |
379 | ecryptfs_printk(KERN_DEBUG, " * crypt_stat->header_extent_size = " | |
380 | "[%d]\n", crypt_stat->header_extent_size); | |
381 | ecryptfs_printk(KERN_DEBUG, " * crypt_stat->" | |
382 | "num_header_extents_at_front = [%d]\n", | |
383 | crypt_stat->num_header_extents_at_front); | |
384 | ecryptfs_printk(KERN_DEBUG, " * extents_occupied_by_headers_at_" | |
385 | "front = [%d]\n", extents_occupied_by_headers_at_front); | |
386 | ecryptfs_printk(KERN_DEBUG, " * lower_extent_num = [0x%.16x]\n", | |
387 | lower_extent_num); | |
388 | ecryptfs_printk(KERN_DEBUG, " * extents_per_page = [%d]\n", | |
389 | extents_per_page); | |
390 | ecryptfs_printk(KERN_DEBUG, " * (*lower_page_idx) = [0x%.16x]\n", | |
391 | (*lower_page_idx)); | |
392 | ecryptfs_printk(KERN_DEBUG, " * extent_offset = [%d]\n", | |
393 | extent_offset); | |
394 | ecryptfs_printk(KERN_DEBUG, " * (*byte_offset) = [%d]\n", | |
395 | (*byte_offset)); | |
396 | } | |
397 | ||
398 | static int ecryptfs_write_out_page(struct ecryptfs_page_crypt_context *ctx, | |
399 | struct page *lower_page, | |
400 | struct inode *lower_inode, | |
401 | int byte_offset_in_page, int bytes_to_write) | |
402 | { | |
403 | int rc = 0; | |
404 | ||
405 | if (ctx->mode == ECRYPTFS_PREPARE_COMMIT_MODE) { | |
406 | rc = ecryptfs_commit_lower_page(lower_page, lower_inode, | |
407 | ctx->param.lower_file, | |
408 | byte_offset_in_page, | |
409 | bytes_to_write); | |
410 | if (rc) { | |
411 | ecryptfs_printk(KERN_ERR, "Error calling lower " | |
412 | "commit; rc = [%d]\n", rc); | |
413 | goto out; | |
414 | } | |
415 | } else { | |
416 | rc = ecryptfs_writepage_and_release_lower_page(lower_page, | |
417 | lower_inode, | |
418 | ctx->param.wbc); | |
419 | if (rc) { | |
420 | ecryptfs_printk(KERN_ERR, "Error calling lower " | |
421 | "writepage(); rc = [%d]\n", rc); | |
422 | goto out; | |
423 | } | |
424 | } | |
425 | out: | |
426 | return rc; | |
427 | } | |
428 | ||
429 | static int ecryptfs_read_in_page(struct ecryptfs_page_crypt_context *ctx, | |
430 | struct page **lower_page, | |
431 | struct inode *lower_inode, | |
432 | unsigned long lower_page_idx, | |
433 | int byte_offset_in_page) | |
434 | { | |
435 | int rc = 0; | |
436 | ||
437 | if (ctx->mode == ECRYPTFS_PREPARE_COMMIT_MODE) { | |
438 | /* TODO: Limit this to only the data extents that are | |
439 | * needed */ | |
440 | rc = ecryptfs_get_lower_page(lower_page, lower_inode, | |
441 | ctx->param.lower_file, | |
442 | lower_page_idx, | |
443 | byte_offset_in_page, | |
444 | (PAGE_CACHE_SIZE | |
445 | - byte_offset_in_page)); | |
446 | if (rc) { | |
447 | ecryptfs_printk( | |
448 | KERN_ERR, "Error attempting to grab, map, " | |
449 | "and prepare_write lower page with index " | |
450 | "[0x%.16x]; rc = [%d]\n", lower_page_idx, rc); | |
451 | goto out; | |
452 | } | |
453 | } else { | |
9d8b8ce5 MH |
454 | *lower_page = grab_cache_page(lower_inode->i_mapping, |
455 | lower_page_idx); | |
456 | if (!(*lower_page)) { | |
457 | rc = -EINVAL; | |
237fead6 MH |
458 | ecryptfs_printk( |
459 | KERN_ERR, "Error attempting to grab and map " | |
460 | "lower page with index [0x%.16x]; rc = [%d]\n", | |
461 | lower_page_idx, rc); | |
462 | goto out; | |
463 | } | |
464 | } | |
465 | out: | |
466 | return rc; | |
467 | } | |
468 | ||
469 | /** | |
470 | * ecryptfs_encrypt_page | |
471 | * @ctx: The context of the page | |
472 | * | |
473 | * Encrypt an eCryptfs page. This is done on a per-extent basis. Note | |
474 | * that eCryptfs pages may straddle the lower pages -- for instance, | |
475 | * if the file was created on a machine with an 8K page size | |
476 | * (resulting in an 8K header), and then the file is copied onto a | |
477 | * host with a 32K page size, then when reading page 0 of the eCryptfs | |
478 | * file, 24K of page 0 of the lower file will be read and decrypted, | |
479 | * and then 8K of page 1 of the lower file will be read and decrypted. | |
480 | * | |
481 | * The actual operations performed on each page depends on the | |
482 | * contents of the ecryptfs_page_crypt_context struct. | |
483 | * | |
484 | * Returns zero on success; negative on error | |
485 | */ | |
486 | int ecryptfs_encrypt_page(struct ecryptfs_page_crypt_context *ctx) | |
487 | { | |
488 | char extent_iv[ECRYPTFS_MAX_IV_BYTES]; | |
489 | unsigned long base_extent; | |
490 | unsigned long extent_offset = 0; | |
491 | unsigned long lower_page_idx = 0; | |
492 | unsigned long prior_lower_page_idx = 0; | |
493 | struct page *lower_page; | |
494 | struct inode *lower_inode; | |
495 | struct ecryptfs_inode_info *inode_info; | |
496 | struct ecryptfs_crypt_stat *crypt_stat; | |
497 | int rc = 0; | |
498 | int lower_byte_offset = 0; | |
499 | int orig_byte_offset = 0; | |
500 | int num_extents_per_page; | |
501 | #define ECRYPTFS_PAGE_STATE_UNREAD 0 | |
502 | #define ECRYPTFS_PAGE_STATE_READ 1 | |
503 | #define ECRYPTFS_PAGE_STATE_MODIFIED 2 | |
504 | #define ECRYPTFS_PAGE_STATE_WRITTEN 3 | |
505 | int page_state; | |
506 | ||
507 | lower_inode = ecryptfs_inode_to_lower(ctx->page->mapping->host); | |
508 | inode_info = ecryptfs_inode_to_private(ctx->page->mapping->host); | |
509 | crypt_stat = &inode_info->crypt_stat; | |
e2bd99ec | 510 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
237fead6 MH |
511 | rc = ecryptfs_copy_page_to_lower(ctx->page, lower_inode, |
512 | ctx->param.lower_file); | |
513 | if (rc) | |
514 | ecryptfs_printk(KERN_ERR, "Error attempting to copy " | |
515 | "page at index [0x%.16x]\n", | |
516 | ctx->page->index); | |
517 | goto out; | |
518 | } | |
519 | num_extents_per_page = PAGE_CACHE_SIZE / crypt_stat->extent_size; | |
520 | base_extent = (ctx->page->index * num_extents_per_page); | |
521 | page_state = ECRYPTFS_PAGE_STATE_UNREAD; | |
522 | while (extent_offset < num_extents_per_page) { | |
523 | ecryptfs_extent_to_lwr_pg_idx_and_offset( | |
524 | &lower_page_idx, &lower_byte_offset, crypt_stat, | |
525 | (base_extent + extent_offset)); | |
526 | if (prior_lower_page_idx != lower_page_idx | |
527 | && page_state == ECRYPTFS_PAGE_STATE_MODIFIED) { | |
528 | rc = ecryptfs_write_out_page(ctx, lower_page, | |
529 | lower_inode, | |
530 | orig_byte_offset, | |
531 | (PAGE_CACHE_SIZE | |
532 | - orig_byte_offset)); | |
533 | if (rc) { | |
534 | ecryptfs_printk(KERN_ERR, "Error attempting " | |
535 | "to write out page; rc = [%d]" | |
536 | "\n", rc); | |
537 | goto out; | |
538 | } | |
539 | page_state = ECRYPTFS_PAGE_STATE_WRITTEN; | |
540 | } | |
541 | if (page_state == ECRYPTFS_PAGE_STATE_UNREAD | |
542 | || page_state == ECRYPTFS_PAGE_STATE_WRITTEN) { | |
543 | rc = ecryptfs_read_in_page(ctx, &lower_page, | |
544 | lower_inode, lower_page_idx, | |
545 | lower_byte_offset); | |
546 | if (rc) { | |
547 | ecryptfs_printk(KERN_ERR, "Error attempting " | |
548 | "to read in lower page with " | |
549 | "index [0x%.16x]; rc = [%d]\n", | |
550 | lower_page_idx, rc); | |
551 | goto out; | |
552 | } | |
553 | orig_byte_offset = lower_byte_offset; | |
554 | prior_lower_page_idx = lower_page_idx; | |
555 | page_state = ECRYPTFS_PAGE_STATE_READ; | |
556 | } | |
557 | BUG_ON(!(page_state == ECRYPTFS_PAGE_STATE_MODIFIED | |
558 | || page_state == ECRYPTFS_PAGE_STATE_READ)); | |
559 | rc = ecryptfs_derive_iv(extent_iv, crypt_stat, | |
560 | (base_extent + extent_offset)); | |
561 | if (rc) { | |
562 | ecryptfs_printk(KERN_ERR, "Error attempting to " | |
563 | "derive IV for extent [0x%.16x]; " | |
564 | "rc = [%d]\n", | |
565 | (base_extent + extent_offset), rc); | |
566 | goto out; | |
567 | } | |
568 | if (unlikely(ecryptfs_verbosity > 0)) { | |
569 | ecryptfs_printk(KERN_DEBUG, "Encrypting extent " | |
570 | "with iv:\n"); | |
571 | ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes); | |
572 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes before " | |
573 | "encryption:\n"); | |
574 | ecryptfs_dump_hex((char *) | |
575 | (page_address(ctx->page) | |
576 | + (extent_offset | |
577 | * crypt_stat->extent_size)), 8); | |
578 | } | |
579 | rc = ecryptfs_encrypt_page_offset( | |
580 | crypt_stat, lower_page, lower_byte_offset, ctx->page, | |
581 | (extent_offset * crypt_stat->extent_size), | |
582 | crypt_stat->extent_size, extent_iv); | |
583 | ecryptfs_printk(KERN_DEBUG, "Encrypt extent [0x%.16x]; " | |
584 | "rc = [%d]\n", | |
585 | (base_extent + extent_offset), rc); | |
586 | if (unlikely(ecryptfs_verbosity > 0)) { | |
587 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes after " | |
588 | "encryption:\n"); | |
589 | ecryptfs_dump_hex((char *)(page_address(lower_page) | |
590 | + lower_byte_offset), 8); | |
591 | } | |
592 | page_state = ECRYPTFS_PAGE_STATE_MODIFIED; | |
593 | extent_offset++; | |
594 | } | |
595 | BUG_ON(orig_byte_offset != 0); | |
596 | rc = ecryptfs_write_out_page(ctx, lower_page, lower_inode, 0, | |
597 | (lower_byte_offset | |
598 | + crypt_stat->extent_size)); | |
599 | if (rc) { | |
600 | ecryptfs_printk(KERN_ERR, "Error attempting to write out " | |
601 | "page; rc = [%d]\n", rc); | |
602 | goto out; | |
603 | } | |
604 | out: | |
605 | return rc; | |
606 | } | |
607 | ||
608 | /** | |
609 | * ecryptfs_decrypt_page | |
610 | * @file: The ecryptfs file | |
611 | * @page: The page in ecryptfs to decrypt | |
612 | * | |
613 | * Decrypt an eCryptfs page. This is done on a per-extent basis. Note | |
614 | * that eCryptfs pages may straddle the lower pages -- for instance, | |
615 | * if the file was created on a machine with an 8K page size | |
616 | * (resulting in an 8K header), and then the file is copied onto a | |
617 | * host with a 32K page size, then when reading page 0 of the eCryptfs | |
618 | * file, 24K of page 0 of the lower file will be read and decrypted, | |
619 | * and then 8K of page 1 of the lower file will be read and decrypted. | |
620 | * | |
621 | * Returns zero on success; negative on error | |
622 | */ | |
623 | int ecryptfs_decrypt_page(struct file *file, struct page *page) | |
624 | { | |
625 | char extent_iv[ECRYPTFS_MAX_IV_BYTES]; | |
626 | unsigned long base_extent; | |
627 | unsigned long extent_offset = 0; | |
628 | unsigned long lower_page_idx = 0; | |
629 | unsigned long prior_lower_page_idx = 0; | |
630 | struct page *lower_page; | |
631 | char *lower_page_virt = NULL; | |
632 | struct inode *lower_inode; | |
633 | struct ecryptfs_crypt_stat *crypt_stat; | |
634 | int rc = 0; | |
635 | int byte_offset; | |
636 | int num_extents_per_page; | |
637 | int page_state; | |
638 | ||
639 | crypt_stat = &(ecryptfs_inode_to_private( | |
640 | page->mapping->host)->crypt_stat); | |
641 | lower_inode = ecryptfs_inode_to_lower(page->mapping->host); | |
e2bd99ec | 642 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
237fead6 MH |
643 | rc = ecryptfs_do_readpage(file, page, page->index); |
644 | if (rc) | |
645 | ecryptfs_printk(KERN_ERR, "Error attempting to copy " | |
646 | "page at index [0x%.16x]\n", | |
647 | page->index); | |
648 | goto out; | |
649 | } | |
650 | num_extents_per_page = PAGE_CACHE_SIZE / crypt_stat->extent_size; | |
651 | base_extent = (page->index * num_extents_per_page); | |
652 | lower_page_virt = kmem_cache_alloc(ecryptfs_lower_page_cache, | |
e94b1766 | 653 | GFP_KERNEL); |
237fead6 MH |
654 | if (!lower_page_virt) { |
655 | rc = -ENOMEM; | |
656 | ecryptfs_printk(KERN_ERR, "Error getting page for encrypted " | |
657 | "lower page(s)\n"); | |
658 | goto out; | |
659 | } | |
660 | lower_page = virt_to_page(lower_page_virt); | |
661 | page_state = ECRYPTFS_PAGE_STATE_UNREAD; | |
662 | while (extent_offset < num_extents_per_page) { | |
663 | ecryptfs_extent_to_lwr_pg_idx_and_offset( | |
664 | &lower_page_idx, &byte_offset, crypt_stat, | |
665 | (base_extent + extent_offset)); | |
666 | if (prior_lower_page_idx != lower_page_idx | |
667 | || page_state == ECRYPTFS_PAGE_STATE_UNREAD) { | |
668 | rc = ecryptfs_do_readpage(file, lower_page, | |
669 | lower_page_idx); | |
670 | if (rc) { | |
671 | ecryptfs_printk(KERN_ERR, "Error reading " | |
672 | "lower encrypted page; rc = " | |
673 | "[%d]\n", rc); | |
674 | goto out; | |
675 | } | |
676 | prior_lower_page_idx = lower_page_idx; | |
677 | page_state = ECRYPTFS_PAGE_STATE_READ; | |
678 | } | |
679 | rc = ecryptfs_derive_iv(extent_iv, crypt_stat, | |
680 | (base_extent + extent_offset)); | |
681 | if (rc) { | |
682 | ecryptfs_printk(KERN_ERR, "Error attempting to " | |
683 | "derive IV for extent [0x%.16x]; rc = " | |
684 | "[%d]\n", | |
685 | (base_extent + extent_offset), rc); | |
686 | goto out; | |
687 | } | |
688 | if (unlikely(ecryptfs_verbosity > 0)) { | |
689 | ecryptfs_printk(KERN_DEBUG, "Decrypting extent " | |
690 | "with iv:\n"); | |
691 | ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes); | |
692 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes before " | |
693 | "decryption:\n"); | |
694 | ecryptfs_dump_hex((lower_page_virt + byte_offset), 8); | |
695 | } | |
696 | rc = ecryptfs_decrypt_page_offset(crypt_stat, page, | |
697 | (extent_offset | |
698 | * crypt_stat->extent_size), | |
699 | lower_page, byte_offset, | |
700 | crypt_stat->extent_size, | |
701 | extent_iv); | |
702 | if (rc != crypt_stat->extent_size) { | |
703 | ecryptfs_printk(KERN_ERR, "Error attempting to " | |
704 | "decrypt extent [0x%.16x]\n", | |
705 | (base_extent + extent_offset)); | |
706 | goto out; | |
707 | } | |
708 | rc = 0; | |
709 | if (unlikely(ecryptfs_verbosity > 0)) { | |
710 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes after " | |
711 | "decryption:\n"); | |
712 | ecryptfs_dump_hex((char *)(page_address(page) | |
713 | + byte_offset), 8); | |
714 | } | |
715 | extent_offset++; | |
716 | } | |
717 | out: | |
718 | if (lower_page_virt) | |
719 | kmem_cache_free(ecryptfs_lower_page_cache, lower_page_virt); | |
720 | return rc; | |
721 | } | |
722 | ||
723 | /** | |
724 | * decrypt_scatterlist | |
22e78faf MH |
725 | * @crypt_stat: Cryptographic context |
726 | * @dest_sg: The destination scatterlist to decrypt into | |
727 | * @src_sg: The source scatterlist to decrypt from | |
728 | * @size: The number of bytes to decrypt | |
729 | * @iv: The initialization vector to use for the decryption | |
237fead6 MH |
730 | * |
731 | * Returns the number of bytes decrypted; negative value on error | |
732 | */ | |
733 | static int decrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, | |
734 | struct scatterlist *dest_sg, | |
735 | struct scatterlist *src_sg, int size, | |
736 | unsigned char *iv) | |
737 | { | |
8bba066f MH |
738 | struct blkcipher_desc desc = { |
739 | .tfm = crypt_stat->tfm, | |
740 | .info = iv, | |
741 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
742 | }; | |
237fead6 MH |
743 | int rc = 0; |
744 | ||
745 | /* Consider doing this once, when the file is opened */ | |
746 | mutex_lock(&crypt_stat->cs_tfm_mutex); | |
8bba066f MH |
747 | rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key, |
748 | crypt_stat->key_size); | |
237fead6 MH |
749 | if (rc) { |
750 | ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n", | |
751 | rc); | |
752 | mutex_unlock(&crypt_stat->cs_tfm_mutex); | |
753 | rc = -EINVAL; | |
754 | goto out; | |
755 | } | |
756 | ecryptfs_printk(KERN_DEBUG, "Decrypting [%d] bytes.\n", size); | |
8bba066f | 757 | rc = crypto_blkcipher_decrypt_iv(&desc, dest_sg, src_sg, size); |
237fead6 MH |
758 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
759 | if (rc) { | |
760 | ecryptfs_printk(KERN_ERR, "Error decrypting; rc = [%d]\n", | |
761 | rc); | |
762 | goto out; | |
763 | } | |
764 | rc = size; | |
765 | out: | |
766 | return rc; | |
767 | } | |
768 | ||
769 | /** | |
770 | * ecryptfs_encrypt_page_offset | |
22e78faf MH |
771 | * @crypt_stat: The cryptographic context |
772 | * @dst_page: The page to encrypt into | |
773 | * @dst_offset: The offset in the page to encrypt into | |
774 | * @src_page: The page to encrypt from | |
775 | * @src_offset: The offset in the page to encrypt from | |
776 | * @size: The number of bytes to encrypt | |
777 | * @iv: The initialization vector to use for the encryption | |
237fead6 MH |
778 | * |
779 | * Returns the number of bytes encrypted | |
780 | */ | |
781 | static int | |
782 | ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
783 | struct page *dst_page, int dst_offset, | |
784 | struct page *src_page, int src_offset, int size, | |
785 | unsigned char *iv) | |
786 | { | |
787 | struct scatterlist src_sg, dst_sg; | |
788 | ||
789 | src_sg.page = src_page; | |
790 | src_sg.offset = src_offset; | |
791 | src_sg.length = size; | |
792 | dst_sg.page = dst_page; | |
793 | dst_sg.offset = dst_offset; | |
794 | dst_sg.length = size; | |
795 | return encrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); | |
796 | } | |
797 | ||
798 | /** | |
799 | * ecryptfs_decrypt_page_offset | |
22e78faf MH |
800 | * @crypt_stat: The cryptographic context |
801 | * @dst_page: The page to decrypt into | |
802 | * @dst_offset: The offset in the page to decrypt into | |
803 | * @src_page: The page to decrypt from | |
804 | * @src_offset: The offset in the page to decrypt from | |
805 | * @size: The number of bytes to decrypt | |
806 | * @iv: The initialization vector to use for the decryption | |
237fead6 MH |
807 | * |
808 | * Returns the number of bytes decrypted | |
809 | */ | |
810 | static int | |
811 | ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
812 | struct page *dst_page, int dst_offset, | |
813 | struct page *src_page, int src_offset, int size, | |
814 | unsigned char *iv) | |
815 | { | |
816 | struct scatterlist src_sg, dst_sg; | |
817 | ||
818 | src_sg.page = src_page; | |
819 | src_sg.offset = src_offset; | |
820 | src_sg.length = size; | |
821 | dst_sg.page = dst_page; | |
822 | dst_sg.offset = dst_offset; | |
823 | dst_sg.length = size; | |
824 | return decrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); | |
825 | } | |
826 | ||
827 | #define ECRYPTFS_MAX_SCATTERLIST_LEN 4 | |
828 | ||
829 | /** | |
830 | * ecryptfs_init_crypt_ctx | |
831 | * @crypt_stat: Uninitilized crypt stats structure | |
832 | * | |
833 | * Initialize the crypto context. | |
834 | * | |
835 | * TODO: Performance: Keep a cache of initialized cipher contexts; | |
836 | * only init if needed | |
837 | */ | |
838 | int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat) | |
839 | { | |
8bba066f | 840 | char *full_alg_name; |
237fead6 MH |
841 | int rc = -EINVAL; |
842 | ||
843 | if (!crypt_stat->cipher) { | |
844 | ecryptfs_printk(KERN_ERR, "No cipher specified\n"); | |
845 | goto out; | |
846 | } | |
847 | ecryptfs_printk(KERN_DEBUG, | |
848 | "Initializing cipher [%s]; strlen = [%d]; " | |
849 | "key_size_bits = [%d]\n", | |
850 | crypt_stat->cipher, (int)strlen(crypt_stat->cipher), | |
851 | crypt_stat->key_size << 3); | |
852 | if (crypt_stat->tfm) { | |
853 | rc = 0; | |
854 | goto out; | |
855 | } | |
856 | mutex_lock(&crypt_stat->cs_tfm_mutex); | |
8bba066f MH |
857 | rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, |
858 | crypt_stat->cipher, "cbc"); | |
859 | if (rc) | |
860 | goto out; | |
861 | crypt_stat->tfm = crypto_alloc_blkcipher(full_alg_name, 0, | |
862 | CRYPTO_ALG_ASYNC); | |
863 | kfree(full_alg_name); | |
de88777e AM |
864 | if (IS_ERR(crypt_stat->tfm)) { |
865 | rc = PTR_ERR(crypt_stat->tfm); | |
237fead6 MH |
866 | ecryptfs_printk(KERN_ERR, "cryptfs: init_crypt_ctx(): " |
867 | "Error initializing cipher [%s]\n", | |
868 | crypt_stat->cipher); | |
8bba066f | 869 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
237fead6 MH |
870 | goto out; |
871 | } | |
f1ddcaf3 | 872 | crypto_blkcipher_set_flags(crypt_stat->tfm, CRYPTO_TFM_REQ_WEAK_KEY); |
8bba066f | 873 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
237fead6 MH |
874 | rc = 0; |
875 | out: | |
876 | return rc; | |
877 | } | |
878 | ||
879 | static void set_extent_mask_and_shift(struct ecryptfs_crypt_stat *crypt_stat) | |
880 | { | |
881 | int extent_size_tmp; | |
882 | ||
883 | crypt_stat->extent_mask = 0xFFFFFFFF; | |
884 | crypt_stat->extent_shift = 0; | |
885 | if (crypt_stat->extent_size == 0) | |
886 | return; | |
887 | extent_size_tmp = crypt_stat->extent_size; | |
888 | while ((extent_size_tmp & 0x01) == 0) { | |
889 | extent_size_tmp >>= 1; | |
890 | crypt_stat->extent_mask <<= 1; | |
891 | crypt_stat->extent_shift++; | |
892 | } | |
893 | } | |
894 | ||
895 | void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat) | |
896 | { | |
897 | /* Default values; may be overwritten as we are parsing the | |
898 | * packets. */ | |
899 | crypt_stat->extent_size = ECRYPTFS_DEFAULT_EXTENT_SIZE; | |
900 | set_extent_mask_and_shift(crypt_stat); | |
901 | crypt_stat->iv_bytes = ECRYPTFS_DEFAULT_IV_BYTES; | |
902 | if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE) { | |
903 | crypt_stat->header_extent_size = | |
904 | ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; | |
905 | } else | |
906 | crypt_stat->header_extent_size = PAGE_CACHE_SIZE; | |
dd2a3b7a MH |
907 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
908 | crypt_stat->num_header_extents_at_front = 0; | |
909 | else | |
910 | crypt_stat->num_header_extents_at_front = 1; | |
237fead6 MH |
911 | } |
912 | ||
913 | /** | |
914 | * ecryptfs_compute_root_iv | |
915 | * @crypt_stats | |
916 | * | |
917 | * On error, sets the root IV to all 0's. | |
918 | */ | |
919 | int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat) | |
920 | { | |
921 | int rc = 0; | |
922 | char dst[MD5_DIGEST_SIZE]; | |
923 | ||
924 | BUG_ON(crypt_stat->iv_bytes > MD5_DIGEST_SIZE); | |
925 | BUG_ON(crypt_stat->iv_bytes <= 0); | |
e2bd99ec | 926 | if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { |
237fead6 MH |
927 | rc = -EINVAL; |
928 | ecryptfs_printk(KERN_WARNING, "Session key not valid; " | |
929 | "cannot generate root IV\n"); | |
930 | goto out; | |
931 | } | |
932 | rc = ecryptfs_calculate_md5(dst, crypt_stat, crypt_stat->key, | |
933 | crypt_stat->key_size); | |
934 | if (rc) { | |
935 | ecryptfs_printk(KERN_WARNING, "Error attempting to compute " | |
936 | "MD5 while generating root IV\n"); | |
937 | goto out; | |
938 | } | |
939 | memcpy(crypt_stat->root_iv, dst, crypt_stat->iv_bytes); | |
940 | out: | |
941 | if (rc) { | |
942 | memset(crypt_stat->root_iv, 0, crypt_stat->iv_bytes); | |
e2bd99ec | 943 | crypt_stat->flags |= ECRYPTFS_SECURITY_WARNING; |
237fead6 MH |
944 | } |
945 | return rc; | |
946 | } | |
947 | ||
948 | static void ecryptfs_generate_new_key(struct ecryptfs_crypt_stat *crypt_stat) | |
949 | { | |
950 | get_random_bytes(crypt_stat->key, crypt_stat->key_size); | |
e2bd99ec | 951 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; |
237fead6 MH |
952 | ecryptfs_compute_root_iv(crypt_stat); |
953 | if (unlikely(ecryptfs_verbosity > 0)) { | |
954 | ecryptfs_printk(KERN_DEBUG, "Generated new session key:\n"); | |
955 | ecryptfs_dump_hex(crypt_stat->key, | |
956 | crypt_stat->key_size); | |
957 | } | |
958 | } | |
959 | ||
17398957 MH |
960 | /** |
961 | * ecryptfs_copy_mount_wide_flags_to_inode_flags | |
22e78faf MH |
962 | * @crypt_stat: The inode's cryptographic context |
963 | * @mount_crypt_stat: The mount point's cryptographic context | |
17398957 MH |
964 | * |
965 | * This function propagates the mount-wide flags to individual inode | |
966 | * flags. | |
967 | */ | |
968 | static void ecryptfs_copy_mount_wide_flags_to_inode_flags( | |
969 | struct ecryptfs_crypt_stat *crypt_stat, | |
970 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
971 | { | |
972 | if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) | |
973 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; | |
974 | if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) | |
975 | crypt_stat->flags |= ECRYPTFS_VIEW_AS_ENCRYPTED; | |
976 | } | |
977 | ||
f4aad16a MH |
978 | static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs( |
979 | struct ecryptfs_crypt_stat *crypt_stat, | |
980 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
981 | { | |
982 | struct ecryptfs_global_auth_tok *global_auth_tok; | |
983 | int rc = 0; | |
984 | ||
985 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
986 | list_for_each_entry(global_auth_tok, | |
987 | &mount_crypt_stat->global_auth_tok_list, | |
988 | mount_crypt_stat_list) { | |
989 | rc = ecryptfs_add_keysig(crypt_stat, global_auth_tok->sig); | |
990 | if (rc) { | |
991 | printk(KERN_ERR "Error adding keysig; rc = [%d]\n", rc); | |
992 | mutex_unlock( | |
993 | &mount_crypt_stat->global_auth_tok_list_mutex); | |
994 | goto out; | |
995 | } | |
996 | } | |
997 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
998 | out: | |
999 | return rc; | |
1000 | } | |
1001 | ||
237fead6 MH |
1002 | /** |
1003 | * ecryptfs_set_default_crypt_stat_vals | |
22e78faf MH |
1004 | * @crypt_stat: The inode's cryptographic context |
1005 | * @mount_crypt_stat: The mount point's cryptographic context | |
237fead6 MH |
1006 | * |
1007 | * Default values in the event that policy does not override them. | |
1008 | */ | |
1009 | static void ecryptfs_set_default_crypt_stat_vals( | |
1010 | struct ecryptfs_crypt_stat *crypt_stat, | |
1011 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
1012 | { | |
17398957 MH |
1013 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
1014 | mount_crypt_stat); | |
237fead6 MH |
1015 | ecryptfs_set_default_sizes(crypt_stat); |
1016 | strcpy(crypt_stat->cipher, ECRYPTFS_DEFAULT_CIPHER); | |
1017 | crypt_stat->key_size = ECRYPTFS_DEFAULT_KEY_BYTES; | |
e2bd99ec | 1018 | crypt_stat->flags &= ~(ECRYPTFS_KEY_VALID); |
237fead6 MH |
1019 | crypt_stat->file_version = ECRYPTFS_FILE_VERSION; |
1020 | crypt_stat->mount_crypt_stat = mount_crypt_stat; | |
1021 | } | |
1022 | ||
1023 | /** | |
1024 | * ecryptfs_new_file_context | |
22e78faf | 1025 | * @ecryptfs_dentry: The eCryptfs dentry |
237fead6 MH |
1026 | * |
1027 | * If the crypto context for the file has not yet been established, | |
1028 | * this is where we do that. Establishing a new crypto context | |
1029 | * involves the following decisions: | |
1030 | * - What cipher to use? | |
1031 | * - What set of authentication tokens to use? | |
1032 | * Here we just worry about getting enough information into the | |
1033 | * authentication tokens so that we know that they are available. | |
1034 | * We associate the available authentication tokens with the new file | |
1035 | * via the set of signatures in the crypt_stat struct. Later, when | |
1036 | * the headers are actually written out, we may again defer to | |
1037 | * userspace to perform the encryption of the session key; for the | |
1038 | * foreseeable future, this will be the case with public key packets. | |
1039 | * | |
1040 | * Returns zero on success; non-zero otherwise | |
1041 | */ | |
237fead6 MH |
1042 | int ecryptfs_new_file_context(struct dentry *ecryptfs_dentry) |
1043 | { | |
237fead6 MH |
1044 | struct ecryptfs_crypt_stat *crypt_stat = |
1045 | &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; | |
1046 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = | |
1047 | &ecryptfs_superblock_to_private( | |
1048 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
1049 | int cipher_name_len; | |
f4aad16a | 1050 | int rc = 0; |
237fead6 MH |
1051 | |
1052 | ecryptfs_set_default_crypt_stat_vals(crypt_stat, mount_crypt_stat); | |
af655dc6 | 1053 | crypt_stat->flags |= (ECRYPTFS_ENCRYPTED | ECRYPTFS_KEY_VALID); |
f4aad16a MH |
1054 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
1055 | mount_crypt_stat); | |
1056 | rc = ecryptfs_copy_mount_wide_sigs_to_inode_sigs(crypt_stat, | |
1057 | mount_crypt_stat); | |
1058 | if (rc) { | |
1059 | printk(KERN_ERR "Error attempting to copy mount-wide key sigs " | |
1060 | "to the inode key sigs; rc = [%d]\n", rc); | |
1061 | goto out; | |
1062 | } | |
1063 | cipher_name_len = | |
1064 | strlen(mount_crypt_stat->global_default_cipher_name); | |
1065 | memcpy(crypt_stat->cipher, | |
1066 | mount_crypt_stat->global_default_cipher_name, | |
1067 | cipher_name_len); | |
1068 | crypt_stat->cipher[cipher_name_len] = '\0'; | |
1069 | crypt_stat->key_size = | |
1070 | mount_crypt_stat->global_default_cipher_key_size; | |
1071 | ecryptfs_generate_new_key(crypt_stat); | |
237fead6 MH |
1072 | rc = ecryptfs_init_crypt_ctx(crypt_stat); |
1073 | if (rc) | |
1074 | ecryptfs_printk(KERN_ERR, "Error initializing cryptographic " | |
1075 | "context for cipher [%s]: rc = [%d]\n", | |
1076 | crypt_stat->cipher, rc); | |
f4aad16a | 1077 | out: |
237fead6 MH |
1078 | return rc; |
1079 | } | |
1080 | ||
1081 | /** | |
1082 | * contains_ecryptfs_marker - check for the ecryptfs marker | |
1083 | * @data: The data block in which to check | |
1084 | * | |
1085 | * Returns one if marker found; zero if not found | |
1086 | */ | |
dd2a3b7a | 1087 | static int contains_ecryptfs_marker(char *data) |
237fead6 MH |
1088 | { |
1089 | u32 m_1, m_2; | |
1090 | ||
1091 | memcpy(&m_1, data, 4); | |
1092 | m_1 = be32_to_cpu(m_1); | |
1093 | memcpy(&m_2, (data + 4), 4); | |
1094 | m_2 = be32_to_cpu(m_2); | |
1095 | if ((m_1 ^ MAGIC_ECRYPTFS_MARKER) == m_2) | |
1096 | return 1; | |
1097 | ecryptfs_printk(KERN_DEBUG, "m_1 = [0x%.8x]; m_2 = [0x%.8x]; " | |
1098 | "MAGIC_ECRYPTFS_MARKER = [0x%.8x]\n", m_1, m_2, | |
1099 | MAGIC_ECRYPTFS_MARKER); | |
1100 | ecryptfs_printk(KERN_DEBUG, "(m_1 ^ MAGIC_ECRYPTFS_MARKER) = " | |
1101 | "[0x%.8x]\n", (m_1 ^ MAGIC_ECRYPTFS_MARKER)); | |
1102 | return 0; | |
1103 | } | |
1104 | ||
1105 | struct ecryptfs_flag_map_elem { | |
1106 | u32 file_flag; | |
1107 | u32 local_flag; | |
1108 | }; | |
1109 | ||
1110 | /* Add support for additional flags by adding elements here. */ | |
1111 | static struct ecryptfs_flag_map_elem ecryptfs_flag_map[] = { | |
1112 | {0x00000001, ECRYPTFS_ENABLE_HMAC}, | |
dd2a3b7a MH |
1113 | {0x00000002, ECRYPTFS_ENCRYPTED}, |
1114 | {0x00000004, ECRYPTFS_METADATA_IN_XATTR} | |
237fead6 MH |
1115 | }; |
1116 | ||
1117 | /** | |
1118 | * ecryptfs_process_flags | |
22e78faf | 1119 | * @crypt_stat: The cryptographic context |
237fead6 MH |
1120 | * @page_virt: Source data to be parsed |
1121 | * @bytes_read: Updated with the number of bytes read | |
1122 | * | |
1123 | * Returns zero on success; non-zero if the flag set is invalid | |
1124 | */ | |
1125 | static int ecryptfs_process_flags(struct ecryptfs_crypt_stat *crypt_stat, | |
1126 | char *page_virt, int *bytes_read) | |
1127 | { | |
1128 | int rc = 0; | |
1129 | int i; | |
1130 | u32 flags; | |
1131 | ||
1132 | memcpy(&flags, page_virt, 4); | |
1133 | flags = be32_to_cpu(flags); | |
1134 | for (i = 0; i < ((sizeof(ecryptfs_flag_map) | |
1135 | / sizeof(struct ecryptfs_flag_map_elem))); i++) | |
1136 | if (flags & ecryptfs_flag_map[i].file_flag) { | |
e2bd99ec | 1137 | crypt_stat->flags |= ecryptfs_flag_map[i].local_flag; |
237fead6 | 1138 | } else |
e2bd99ec | 1139 | crypt_stat->flags &= ~(ecryptfs_flag_map[i].local_flag); |
237fead6 MH |
1140 | /* Version is in top 8 bits of the 32-bit flag vector */ |
1141 | crypt_stat->file_version = ((flags >> 24) & 0xFF); | |
1142 | (*bytes_read) = 4; | |
1143 | return rc; | |
1144 | } | |
1145 | ||
1146 | /** | |
1147 | * write_ecryptfs_marker | |
1148 | * @page_virt: The pointer to in a page to begin writing the marker | |
1149 | * @written: Number of bytes written | |
1150 | * | |
1151 | * Marker = 0x3c81b7f5 | |
1152 | */ | |
1153 | static void write_ecryptfs_marker(char *page_virt, size_t *written) | |
1154 | { | |
1155 | u32 m_1, m_2; | |
1156 | ||
1157 | get_random_bytes(&m_1, (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); | |
1158 | m_2 = (m_1 ^ MAGIC_ECRYPTFS_MARKER); | |
1159 | m_1 = cpu_to_be32(m_1); | |
1160 | memcpy(page_virt, &m_1, (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); | |
1161 | m_2 = cpu_to_be32(m_2); | |
1162 | memcpy(page_virt + (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2), &m_2, | |
1163 | (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); | |
1164 | (*written) = MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; | |
1165 | } | |
1166 | ||
1167 | static void | |
1168 | write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat, | |
1169 | size_t *written) | |
1170 | { | |
1171 | u32 flags = 0; | |
1172 | int i; | |
1173 | ||
1174 | for (i = 0; i < ((sizeof(ecryptfs_flag_map) | |
1175 | / sizeof(struct ecryptfs_flag_map_elem))); i++) | |
e2bd99ec | 1176 | if (crypt_stat->flags & ecryptfs_flag_map[i].local_flag) |
237fead6 MH |
1177 | flags |= ecryptfs_flag_map[i].file_flag; |
1178 | /* Version is in top 8 bits of the 32-bit flag vector */ | |
1179 | flags |= ((((u8)crypt_stat->file_version) << 24) & 0xFF000000); | |
1180 | flags = cpu_to_be32(flags); | |
1181 | memcpy(page_virt, &flags, 4); | |
1182 | (*written) = 4; | |
1183 | } | |
1184 | ||
1185 | struct ecryptfs_cipher_code_str_map_elem { | |
1186 | char cipher_str[16]; | |
1187 | u16 cipher_code; | |
1188 | }; | |
1189 | ||
1190 | /* Add support for additional ciphers by adding elements here. The | |
1191 | * cipher_code is whatever OpenPGP applicatoins use to identify the | |
1192 | * ciphers. List in order of probability. */ | |
1193 | static struct ecryptfs_cipher_code_str_map_elem | |
1194 | ecryptfs_cipher_code_str_map[] = { | |
1195 | {"aes",RFC2440_CIPHER_AES_128 }, | |
1196 | {"blowfish", RFC2440_CIPHER_BLOWFISH}, | |
1197 | {"des3_ede", RFC2440_CIPHER_DES3_EDE}, | |
1198 | {"cast5", RFC2440_CIPHER_CAST_5}, | |
1199 | {"twofish", RFC2440_CIPHER_TWOFISH}, | |
1200 | {"cast6", RFC2440_CIPHER_CAST_6}, | |
1201 | {"aes", RFC2440_CIPHER_AES_192}, | |
1202 | {"aes", RFC2440_CIPHER_AES_256} | |
1203 | }; | |
1204 | ||
1205 | /** | |
1206 | * ecryptfs_code_for_cipher_string | |
22e78faf | 1207 | * @crypt_stat: The cryptographic context |
237fead6 MH |
1208 | * |
1209 | * Returns zero on no match, or the cipher code on match | |
1210 | */ | |
1211 | u16 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat) | |
1212 | { | |
1213 | int i; | |
1214 | u16 code = 0; | |
1215 | struct ecryptfs_cipher_code_str_map_elem *map = | |
1216 | ecryptfs_cipher_code_str_map; | |
1217 | ||
1218 | if (strcmp(crypt_stat->cipher, "aes") == 0) { | |
1219 | switch (crypt_stat->key_size) { | |
1220 | case 16: | |
1221 | code = RFC2440_CIPHER_AES_128; | |
1222 | break; | |
1223 | case 24: | |
1224 | code = RFC2440_CIPHER_AES_192; | |
1225 | break; | |
1226 | case 32: | |
1227 | code = RFC2440_CIPHER_AES_256; | |
1228 | } | |
1229 | } else { | |
1230 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++) | |
1231 | if (strcmp(crypt_stat->cipher, map[i].cipher_str) == 0){ | |
1232 | code = map[i].cipher_code; | |
1233 | break; | |
1234 | } | |
1235 | } | |
1236 | return code; | |
1237 | } | |
1238 | ||
1239 | /** | |
1240 | * ecryptfs_cipher_code_to_string | |
1241 | * @str: Destination to write out the cipher name | |
1242 | * @cipher_code: The code to convert to cipher name string | |
1243 | * | |
1244 | * Returns zero on success | |
1245 | */ | |
1246 | int ecryptfs_cipher_code_to_string(char *str, u16 cipher_code) | |
1247 | { | |
1248 | int rc = 0; | |
1249 | int i; | |
1250 | ||
1251 | str[0] = '\0'; | |
1252 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++) | |
1253 | if (cipher_code == ecryptfs_cipher_code_str_map[i].cipher_code) | |
1254 | strcpy(str, ecryptfs_cipher_code_str_map[i].cipher_str); | |
1255 | if (str[0] == '\0') { | |
1256 | ecryptfs_printk(KERN_WARNING, "Cipher code not recognized: " | |
1257 | "[%d]\n", cipher_code); | |
1258 | rc = -EINVAL; | |
1259 | } | |
1260 | return rc; | |
1261 | } | |
1262 | ||
1263 | /** | |
1264 | * ecryptfs_read_header_region | |
22e78faf MH |
1265 | * @data: The virtual address to write header region data into |
1266 | * @dentry: The lower dentry | |
1267 | * @mnt: The lower VFS mount | |
237fead6 MH |
1268 | * |
1269 | * Returns zero on success; non-zero otherwise | |
1270 | */ | |
dd2a3b7a MH |
1271 | static int ecryptfs_read_header_region(char *data, struct dentry *dentry, |
1272 | struct vfsmount *mnt) | |
237fead6 | 1273 | { |
7ff1d74f | 1274 | struct file *lower_file; |
237fead6 MH |
1275 | mm_segment_t oldfs; |
1276 | int rc; | |
1277 | ||
7ff1d74f MH |
1278 | if ((rc = ecryptfs_open_lower_file(&lower_file, dentry, mnt, |
1279 | O_RDONLY))) { | |
1280 | printk(KERN_ERR | |
1281 | "Error opening lower_file to read header region\n"); | |
237fead6 MH |
1282 | goto out; |
1283 | } | |
7ff1d74f | 1284 | lower_file->f_pos = 0; |
237fead6 MH |
1285 | oldfs = get_fs(); |
1286 | set_fs(get_ds()); | |
7ff1d74f MH |
1287 | rc = lower_file->f_op->read(lower_file, (char __user *)data, |
1288 | ECRYPTFS_DEFAULT_EXTENT_SIZE, &lower_file->f_pos); | |
237fead6 | 1289 | set_fs(oldfs); |
7ff1d74f MH |
1290 | if ((rc = ecryptfs_close_lower_file(lower_file))) { |
1291 | printk(KERN_ERR "Error closing lower_file\n"); | |
1292 | goto out; | |
1293 | } | |
237fead6 MH |
1294 | rc = 0; |
1295 | out: | |
1296 | return rc; | |
1297 | } | |
1298 | ||
dd2a3b7a MH |
1299 | int ecryptfs_read_and_validate_header_region(char *data, struct dentry *dentry, |
1300 | struct vfsmount *mnt) | |
1301 | { | |
1302 | int rc; | |
1303 | ||
1304 | rc = ecryptfs_read_header_region(data, dentry, mnt); | |
1305 | if (rc) | |
1306 | goto out; | |
1307 | if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) | |
1308 | rc = -EINVAL; | |
1309 | out: | |
1310 | return rc; | |
1311 | } | |
1312 | ||
1313 | ||
e77a56dd MH |
1314 | void |
1315 | ecryptfs_write_header_metadata(char *virt, | |
1316 | struct ecryptfs_crypt_stat *crypt_stat, | |
1317 | size_t *written) | |
237fead6 MH |
1318 | { |
1319 | u32 header_extent_size; | |
1320 | u16 num_header_extents_at_front; | |
1321 | ||
1322 | header_extent_size = (u32)crypt_stat->header_extent_size; | |
1323 | num_header_extents_at_front = | |
1324 | (u16)crypt_stat->num_header_extents_at_front; | |
1325 | header_extent_size = cpu_to_be32(header_extent_size); | |
1326 | memcpy(virt, &header_extent_size, 4); | |
1327 | virt += 4; | |
1328 | num_header_extents_at_front = cpu_to_be16(num_header_extents_at_front); | |
1329 | memcpy(virt, &num_header_extents_at_front, 2); | |
1330 | (*written) = 6; | |
1331 | } | |
1332 | ||
1333 | struct kmem_cache *ecryptfs_header_cache_0; | |
1334 | struct kmem_cache *ecryptfs_header_cache_1; | |
1335 | struct kmem_cache *ecryptfs_header_cache_2; | |
1336 | ||
1337 | /** | |
1338 | * ecryptfs_write_headers_virt | |
22e78faf MH |
1339 | * @page_virt: The virtual address to write the headers to |
1340 | * @size: Set to the number of bytes written by this function | |
1341 | * @crypt_stat: The cryptographic context | |
1342 | * @ecryptfs_dentry: The eCryptfs dentry | |
237fead6 MH |
1343 | * |
1344 | * Format version: 1 | |
1345 | * | |
1346 | * Header Extent: | |
1347 | * Octets 0-7: Unencrypted file size (big-endian) | |
1348 | * Octets 8-15: eCryptfs special marker | |
1349 | * Octets 16-19: Flags | |
1350 | * Octet 16: File format version number (between 0 and 255) | |
1351 | * Octets 17-18: Reserved | |
1352 | * Octet 19: Bit 1 (lsb): Reserved | |
1353 | * Bit 2: Encrypted? | |
1354 | * Bits 3-8: Reserved | |
1355 | * Octets 20-23: Header extent size (big-endian) | |
1356 | * Octets 24-25: Number of header extents at front of file | |
1357 | * (big-endian) | |
1358 | * Octet 26: Begin RFC 2440 authentication token packet set | |
1359 | * Data Extent 0: | |
1360 | * Lower data (CBC encrypted) | |
1361 | * Data Extent 1: | |
1362 | * Lower data (CBC encrypted) | |
1363 | * ... | |
1364 | * | |
1365 | * Returns zero on success | |
1366 | */ | |
dd2a3b7a MH |
1367 | static int ecryptfs_write_headers_virt(char *page_virt, size_t *size, |
1368 | struct ecryptfs_crypt_stat *crypt_stat, | |
1369 | struct dentry *ecryptfs_dentry) | |
237fead6 MH |
1370 | { |
1371 | int rc; | |
1372 | size_t written; | |
1373 | size_t offset; | |
1374 | ||
1375 | offset = ECRYPTFS_FILE_SIZE_BYTES; | |
1376 | write_ecryptfs_marker((page_virt + offset), &written); | |
1377 | offset += written; | |
1378 | write_ecryptfs_flags((page_virt + offset), crypt_stat, &written); | |
1379 | offset += written; | |
e77a56dd MH |
1380 | ecryptfs_write_header_metadata((page_virt + offset), crypt_stat, |
1381 | &written); | |
237fead6 MH |
1382 | offset += written; |
1383 | rc = ecryptfs_generate_key_packet_set((page_virt + offset), crypt_stat, | |
1384 | ecryptfs_dentry, &written, | |
1385 | PAGE_CACHE_SIZE - offset); | |
1386 | if (rc) | |
1387 | ecryptfs_printk(KERN_WARNING, "Error generating key packet " | |
1388 | "set; rc = [%d]\n", rc); | |
dd2a3b7a MH |
1389 | if (size) { |
1390 | offset += written; | |
1391 | *size = offset; | |
1392 | } | |
1393 | return rc; | |
1394 | } | |
1395 | ||
22e78faf MH |
1396 | static int |
1397 | ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat, | |
1398 | struct file *lower_file, char *page_virt) | |
dd2a3b7a MH |
1399 | { |
1400 | mm_segment_t oldfs; | |
1401 | int current_header_page; | |
1402 | int header_pages; | |
70456600 MH |
1403 | ssize_t size; |
1404 | int rc = 0; | |
dd2a3b7a MH |
1405 | |
1406 | lower_file->f_pos = 0; | |
1407 | oldfs = get_fs(); | |
1408 | set_fs(get_ds()); | |
70456600 MH |
1409 | size = vfs_write(lower_file, (char __user *)page_virt, PAGE_CACHE_SIZE, |
1410 | &lower_file->f_pos); | |
1411 | if (size < 0) { | |
1412 | rc = (int)size; | |
1413 | printk(KERN_ERR "Error attempting to write lower page; " | |
1414 | "rc = [%d]\n", rc); | |
1415 | set_fs(oldfs); | |
1416 | goto out; | |
1417 | } | |
dd2a3b7a MH |
1418 | header_pages = ((crypt_stat->header_extent_size |
1419 | * crypt_stat->num_header_extents_at_front) | |
1420 | / PAGE_CACHE_SIZE); | |
1421 | memset(page_virt, 0, PAGE_CACHE_SIZE); | |
1422 | current_header_page = 1; | |
1423 | while (current_header_page < header_pages) { | |
70456600 MH |
1424 | size = vfs_write(lower_file, (char __user *)page_virt, |
1425 | PAGE_CACHE_SIZE, &lower_file->f_pos); | |
1426 | if (size < 0) { | |
1427 | rc = (int)size; | |
1428 | printk(KERN_ERR "Error attempting to write lower page; " | |
1429 | "rc = [%d]\n", rc); | |
1430 | set_fs(oldfs); | |
1431 | goto out; | |
1432 | } | |
dd2a3b7a MH |
1433 | current_header_page++; |
1434 | } | |
1435 | set_fs(oldfs); | |
70456600 MH |
1436 | out: |
1437 | return rc; | |
dd2a3b7a MH |
1438 | } |
1439 | ||
22e78faf MH |
1440 | static int |
1441 | ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, | |
1442 | struct ecryptfs_crypt_stat *crypt_stat, | |
1443 | char *page_virt, size_t size) | |
dd2a3b7a MH |
1444 | { |
1445 | int rc; | |
1446 | ||
1447 | rc = ecryptfs_setxattr(ecryptfs_dentry, ECRYPTFS_XATTR_NAME, page_virt, | |
1448 | size, 0); | |
237fead6 MH |
1449 | return rc; |
1450 | } | |
1451 | ||
1452 | /** | |
dd2a3b7a | 1453 | * ecryptfs_write_metadata |
22e78faf | 1454 | * @ecryptfs_dentry: The eCryptfs dentry |
237fead6 MH |
1455 | * @lower_file: The lower file struct, which was returned from dentry_open |
1456 | * | |
1457 | * Write the file headers out. This will likely involve a userspace | |
1458 | * callout, in which the session key is encrypted with one or more | |
1459 | * public keys and/or the passphrase necessary to do the encryption is | |
1460 | * retrieved via a prompt. Exactly what happens at this point should | |
1461 | * be policy-dependent. | |
1462 | * | |
1463 | * Returns zero on success; non-zero on error | |
1464 | */ | |
dd2a3b7a MH |
1465 | int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry, |
1466 | struct file *lower_file) | |
237fead6 | 1467 | { |
237fead6 MH |
1468 | struct ecryptfs_crypt_stat *crypt_stat; |
1469 | char *page_virt; | |
dd2a3b7a | 1470 | size_t size; |
237fead6 MH |
1471 | int rc = 0; |
1472 | ||
1473 | crypt_stat = &ecryptfs_inode_to_private( | |
1474 | ecryptfs_dentry->d_inode)->crypt_stat; | |
e2bd99ec MH |
1475 | if (likely(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
1476 | if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { | |
237fead6 MH |
1477 | ecryptfs_printk(KERN_DEBUG, "Key is " |
1478 | "invalid; bailing out\n"); | |
1479 | rc = -EINVAL; | |
1480 | goto out; | |
1481 | } | |
1482 | } else { | |
1483 | rc = -EINVAL; | |
1484 | ecryptfs_printk(KERN_WARNING, | |
1485 | "Called with crypt_stat->encrypted == 0\n"); | |
1486 | goto out; | |
1487 | } | |
1488 | /* Released in this function */ | |
c3762229 | 1489 | page_virt = kmem_cache_zalloc(ecryptfs_header_cache_0, GFP_USER); |
237fead6 MH |
1490 | if (!page_virt) { |
1491 | ecryptfs_printk(KERN_ERR, "Out of memory\n"); | |
1492 | rc = -ENOMEM; | |
1493 | goto out; | |
1494 | } | |
dd2a3b7a MH |
1495 | rc = ecryptfs_write_headers_virt(page_virt, &size, crypt_stat, |
1496 | ecryptfs_dentry); | |
237fead6 MH |
1497 | if (unlikely(rc)) { |
1498 | ecryptfs_printk(KERN_ERR, "Error whilst writing headers\n"); | |
1499 | memset(page_virt, 0, PAGE_CACHE_SIZE); | |
1500 | goto out_free; | |
1501 | } | |
dd2a3b7a MH |
1502 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
1503 | rc = ecryptfs_write_metadata_to_xattr(ecryptfs_dentry, | |
1504 | crypt_stat, page_virt, | |
1505 | size); | |
1506 | else | |
1507 | rc = ecryptfs_write_metadata_to_contents(crypt_stat, lower_file, | |
1508 | page_virt); | |
1509 | if (rc) { | |
1510 | printk(KERN_ERR "Error writing metadata out to lower file; " | |
1511 | "rc = [%d]\n", rc); | |
1512 | goto out_free; | |
237fead6 | 1513 | } |
237fead6 MH |
1514 | out_free: |
1515 | kmem_cache_free(ecryptfs_header_cache_0, page_virt); | |
1516 | out: | |
1517 | return rc; | |
1518 | } | |
1519 | ||
dd2a3b7a MH |
1520 | #define ECRYPTFS_DONT_VALIDATE_HEADER_SIZE 0 |
1521 | #define ECRYPTFS_VALIDATE_HEADER_SIZE 1 | |
237fead6 | 1522 | static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat, |
dd2a3b7a MH |
1523 | char *virt, int *bytes_read, |
1524 | int validate_header_size) | |
237fead6 MH |
1525 | { |
1526 | int rc = 0; | |
1527 | u32 header_extent_size; | |
1528 | u16 num_header_extents_at_front; | |
1529 | ||
1530 | memcpy(&header_extent_size, virt, 4); | |
1531 | header_extent_size = be32_to_cpu(header_extent_size); | |
1532 | virt += 4; | |
1533 | memcpy(&num_header_extents_at_front, virt, 2); | |
1534 | num_header_extents_at_front = be16_to_cpu(num_header_extents_at_front); | |
1535 | crypt_stat->header_extent_size = (int)header_extent_size; | |
1536 | crypt_stat->num_header_extents_at_front = | |
1537 | (int)num_header_extents_at_front; | |
1538 | (*bytes_read) = 6; | |
dd2a3b7a MH |
1539 | if ((validate_header_size == ECRYPTFS_VALIDATE_HEADER_SIZE) |
1540 | && ((crypt_stat->header_extent_size | |
1541 | * crypt_stat->num_header_extents_at_front) | |
1542 | < ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)) { | |
237fead6 MH |
1543 | rc = -EINVAL; |
1544 | ecryptfs_printk(KERN_WARNING, "Invalid header extent size: " | |
1545 | "[%d]\n", crypt_stat->header_extent_size); | |
1546 | } | |
1547 | return rc; | |
1548 | } | |
1549 | ||
1550 | /** | |
1551 | * set_default_header_data | |
22e78faf | 1552 | * @crypt_stat: The cryptographic context |
237fead6 MH |
1553 | * |
1554 | * For version 0 file format; this function is only for backwards | |
1555 | * compatibility for files created with the prior versions of | |
1556 | * eCryptfs. | |
1557 | */ | |
1558 | static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat) | |
1559 | { | |
1560 | crypt_stat->header_extent_size = 4096; | |
1561 | crypt_stat->num_header_extents_at_front = 1; | |
1562 | } | |
1563 | ||
1564 | /** | |
1565 | * ecryptfs_read_headers_virt | |
22e78faf MH |
1566 | * @page_virt: The virtual address into which to read the headers |
1567 | * @crypt_stat: The cryptographic context | |
1568 | * @ecryptfs_dentry: The eCryptfs dentry | |
1569 | * @validate_header_size: Whether to validate the header size while reading | |
237fead6 MH |
1570 | * |
1571 | * Read/parse the header data. The header format is detailed in the | |
1572 | * comment block for the ecryptfs_write_headers_virt() function. | |
1573 | * | |
1574 | * Returns zero on success | |
1575 | */ | |
1576 | static int ecryptfs_read_headers_virt(char *page_virt, | |
1577 | struct ecryptfs_crypt_stat *crypt_stat, | |
dd2a3b7a MH |
1578 | struct dentry *ecryptfs_dentry, |
1579 | int validate_header_size) | |
237fead6 MH |
1580 | { |
1581 | int rc = 0; | |
1582 | int offset; | |
1583 | int bytes_read; | |
1584 | ||
1585 | ecryptfs_set_default_sizes(crypt_stat); | |
1586 | crypt_stat->mount_crypt_stat = &ecryptfs_superblock_to_private( | |
1587 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
1588 | offset = ECRYPTFS_FILE_SIZE_BYTES; | |
1589 | rc = contains_ecryptfs_marker(page_virt + offset); | |
1590 | if (rc == 0) { | |
1591 | rc = -EINVAL; | |
1592 | goto out; | |
1593 | } | |
1594 | offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; | |
1595 | rc = ecryptfs_process_flags(crypt_stat, (page_virt + offset), | |
1596 | &bytes_read); | |
1597 | if (rc) { | |
1598 | ecryptfs_printk(KERN_WARNING, "Error processing flags\n"); | |
1599 | goto out; | |
1600 | } | |
1601 | if (crypt_stat->file_version > ECRYPTFS_SUPPORTED_FILE_VERSION) { | |
1602 | ecryptfs_printk(KERN_WARNING, "File version is [%d]; only " | |
1603 | "file version [%d] is supported by this " | |
1604 | "version of eCryptfs\n", | |
1605 | crypt_stat->file_version, | |
1606 | ECRYPTFS_SUPPORTED_FILE_VERSION); | |
1607 | rc = -EINVAL; | |
1608 | goto out; | |
1609 | } | |
1610 | offset += bytes_read; | |
1611 | if (crypt_stat->file_version >= 1) { | |
1612 | rc = parse_header_metadata(crypt_stat, (page_virt + offset), | |
dd2a3b7a | 1613 | &bytes_read, validate_header_size); |
237fead6 MH |
1614 | if (rc) { |
1615 | ecryptfs_printk(KERN_WARNING, "Error reading header " | |
1616 | "metadata; rc = [%d]\n", rc); | |
1617 | } | |
1618 | offset += bytes_read; | |
1619 | } else | |
1620 | set_default_header_data(crypt_stat); | |
1621 | rc = ecryptfs_parse_packet_set(crypt_stat, (page_virt + offset), | |
1622 | ecryptfs_dentry); | |
1623 | out: | |
1624 | return rc; | |
1625 | } | |
1626 | ||
1627 | /** | |
dd2a3b7a | 1628 | * ecryptfs_read_xattr_region |
22e78faf MH |
1629 | * @page_virt: The vitual address into which to read the xattr data |
1630 | * @ecryptfs_dentry: The eCryptfs dentry | |
dd2a3b7a MH |
1631 | * |
1632 | * Attempts to read the crypto metadata from the extended attribute | |
1633 | * region of the lower file. | |
22e78faf MH |
1634 | * |
1635 | * Returns zero on success; non-zero on error | |
dd2a3b7a MH |
1636 | */ |
1637 | int ecryptfs_read_xattr_region(char *page_virt, struct dentry *ecryptfs_dentry) | |
1638 | { | |
1639 | ssize_t size; | |
1640 | int rc = 0; | |
1641 | ||
1642 | size = ecryptfs_getxattr(ecryptfs_dentry, ECRYPTFS_XATTR_NAME, | |
1643 | page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE); | |
1644 | if (size < 0) { | |
1645 | printk(KERN_DEBUG "Error attempting to read the [%s] " | |
1646 | "xattr from the lower file; return value = [%zd]\n", | |
1647 | ECRYPTFS_XATTR_NAME, size); | |
1648 | rc = -EINVAL; | |
1649 | goto out; | |
1650 | } | |
1651 | out: | |
1652 | return rc; | |
1653 | } | |
1654 | ||
1655 | int ecryptfs_read_and_validate_xattr_region(char *page_virt, | |
1656 | struct dentry *ecryptfs_dentry) | |
1657 | { | |
1658 | int rc; | |
1659 | ||
1660 | rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry); | |
1661 | if (rc) | |
1662 | goto out; | |
1663 | if (!contains_ecryptfs_marker(page_virt + ECRYPTFS_FILE_SIZE_BYTES)) { | |
1664 | printk(KERN_WARNING "Valid data found in [%s] xattr, but " | |
1665 | "the marker is invalid\n", ECRYPTFS_XATTR_NAME); | |
1666 | rc = -EINVAL; | |
1667 | } | |
1668 | out: | |
1669 | return rc; | |
1670 | } | |
1671 | ||
1672 | /** | |
1673 | * ecryptfs_read_metadata | |
22e78faf MH |
1674 | * @ecryptfs_dentry: The eCryptfs dentry |
1675 | * @lower_file: The lower file from which to read the metadata | |
dd2a3b7a MH |
1676 | * |
1677 | * Common entry point for reading file metadata. From here, we could | |
1678 | * retrieve the header information from the header region of the file, | |
1679 | * the xattr region of the file, or some other repostory that is | |
1680 | * stored separately from the file itself. The current implementation | |
1681 | * supports retrieving the metadata information from the file contents | |
1682 | * and from the xattr region. | |
237fead6 MH |
1683 | * |
1684 | * Returns zero if valid headers found and parsed; non-zero otherwise | |
1685 | */ | |
dd2a3b7a MH |
1686 | int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry, |
1687 | struct file *lower_file) | |
237fead6 MH |
1688 | { |
1689 | int rc = 0; | |
1690 | char *page_virt = NULL; | |
1691 | mm_segment_t oldfs; | |
1692 | ssize_t bytes_read; | |
1693 | struct ecryptfs_crypt_stat *crypt_stat = | |
1694 | &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; | |
e77a56dd MH |
1695 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
1696 | &ecryptfs_superblock_to_private( | |
1697 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
237fead6 | 1698 | |
e77a56dd MH |
1699 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
1700 | mount_crypt_stat); | |
237fead6 | 1701 | /* Read the first page from the underlying file */ |
f7267c0c | 1702 | page_virt = kmem_cache_alloc(ecryptfs_header_cache_1, GFP_USER); |
237fead6 MH |
1703 | if (!page_virt) { |
1704 | rc = -ENOMEM; | |
1705 | ecryptfs_printk(KERN_ERR, "Unable to allocate page_virt\n"); | |
1706 | goto out; | |
1707 | } | |
1708 | lower_file->f_pos = 0; | |
1709 | oldfs = get_fs(); | |
1710 | set_fs(get_ds()); | |
1711 | bytes_read = lower_file->f_op->read(lower_file, | |
1712 | (char __user *)page_virt, | |
1713 | ECRYPTFS_DEFAULT_EXTENT_SIZE, | |
1714 | &lower_file->f_pos); | |
1715 | set_fs(oldfs); | |
1716 | if (bytes_read != ECRYPTFS_DEFAULT_EXTENT_SIZE) { | |
1717 | rc = -EINVAL; | |
1718 | goto out; | |
1719 | } | |
1720 | rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, | |
dd2a3b7a MH |
1721 | ecryptfs_dentry, |
1722 | ECRYPTFS_VALIDATE_HEADER_SIZE); | |
237fead6 | 1723 | if (rc) { |
dd2a3b7a MH |
1724 | rc = ecryptfs_read_xattr_region(page_virt, |
1725 | ecryptfs_dentry); | |
1726 | if (rc) { | |
1727 | printk(KERN_DEBUG "Valid eCryptfs headers not found in " | |
1728 | "file header region or xattr region\n"); | |
1729 | rc = -EINVAL; | |
1730 | goto out; | |
1731 | } | |
1732 | rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, | |
1733 | ecryptfs_dentry, | |
1734 | ECRYPTFS_DONT_VALIDATE_HEADER_SIZE); | |
1735 | if (rc) { | |
1736 | printk(KERN_DEBUG "Valid eCryptfs headers not found in " | |
1737 | "file xattr region either\n"); | |
1738 | rc = -EINVAL; | |
1739 | } | |
1740 | if (crypt_stat->mount_crypt_stat->flags | |
1741 | & ECRYPTFS_XATTR_METADATA_ENABLED) { | |
1742 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; | |
1743 | } else { | |
1744 | printk(KERN_WARNING "Attempt to access file with " | |
1745 | "crypto metadata only in the extended attribute " | |
1746 | "region, but eCryptfs was mounted without " | |
1747 | "xattr support enabled. eCryptfs will not treat " | |
1748 | "this like an encrypted file.\n"); | |
1749 | rc = -EINVAL; | |
1750 | } | |
237fead6 MH |
1751 | } |
1752 | out: | |
1753 | if (page_virt) { | |
1754 | memset(page_virt, 0, PAGE_CACHE_SIZE); | |
1755 | kmem_cache_free(ecryptfs_header_cache_1, page_virt); | |
1756 | } | |
1757 | return rc; | |
1758 | } | |
1759 | ||
1760 | /** | |
1761 | * ecryptfs_encode_filename - converts a plaintext file name to cipher text | |
1762 | * @crypt_stat: The crypt_stat struct associated with the file anem to encode | |
1763 | * @name: The plaintext name | |
1764 | * @length: The length of the plaintext | |
1765 | * @encoded_name: The encypted name | |
1766 | * | |
1767 | * Encrypts and encodes a filename into something that constitutes a | |
1768 | * valid filename for a filesystem, with printable characters. | |
1769 | * | |
1770 | * We assume that we have a properly initialized crypto context, | |
1771 | * pointed to by crypt_stat->tfm. | |
1772 | * | |
1773 | * TODO: Implement filename decoding and decryption here, in place of | |
1774 | * memcpy. We are keeping the framework around for now to (1) | |
1775 | * facilitate testing of the components needed to implement filename | |
1776 | * encryption and (2) to provide a code base from which other | |
1777 | * developers in the community can easily implement this feature. | |
1778 | * | |
1779 | * Returns the length of encoded filename; negative if error | |
1780 | */ | |
1781 | int | |
1782 | ecryptfs_encode_filename(struct ecryptfs_crypt_stat *crypt_stat, | |
1783 | const char *name, int length, char **encoded_name) | |
1784 | { | |
1785 | int error = 0; | |
1786 | ||
1787 | (*encoded_name) = kmalloc(length + 2, GFP_KERNEL); | |
1788 | if (!(*encoded_name)) { | |
1789 | error = -ENOMEM; | |
1790 | goto out; | |
1791 | } | |
1792 | /* TODO: Filename encryption is a scheduled feature for a | |
1793 | * future version of eCryptfs. This function is here only for | |
1794 | * the purpose of providing a framework for other developers | |
1795 | * to easily implement filename encryption. Hint: Replace this | |
1796 | * memcpy() with a call to encrypt and encode the | |
1797 | * filename, the set the length accordingly. */ | |
1798 | memcpy((void *)(*encoded_name), (void *)name, length); | |
1799 | (*encoded_name)[length] = '\0'; | |
1800 | error = length + 1; | |
1801 | out: | |
1802 | return error; | |
1803 | } | |
1804 | ||
1805 | /** | |
1806 | * ecryptfs_decode_filename - converts the cipher text name to plaintext | |
1807 | * @crypt_stat: The crypt_stat struct associated with the file | |
1808 | * @name: The filename in cipher text | |
1809 | * @length: The length of the cipher text name | |
1810 | * @decrypted_name: The plaintext name | |
1811 | * | |
1812 | * Decodes and decrypts the filename. | |
1813 | * | |
1814 | * We assume that we have a properly initialized crypto context, | |
1815 | * pointed to by crypt_stat->tfm. | |
1816 | * | |
1817 | * TODO: Implement filename decoding and decryption here, in place of | |
1818 | * memcpy. We are keeping the framework around for now to (1) | |
1819 | * facilitate testing of the components needed to implement filename | |
1820 | * encryption and (2) to provide a code base from which other | |
1821 | * developers in the community can easily implement this feature. | |
1822 | * | |
1823 | * Returns the length of decoded filename; negative if error | |
1824 | */ | |
1825 | int | |
1826 | ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat, | |
1827 | const char *name, int length, char **decrypted_name) | |
1828 | { | |
1829 | int error = 0; | |
1830 | ||
1831 | (*decrypted_name) = kmalloc(length + 2, GFP_KERNEL); | |
1832 | if (!(*decrypted_name)) { | |
1833 | error = -ENOMEM; | |
1834 | goto out; | |
1835 | } | |
1836 | /* TODO: Filename encryption is a scheduled feature for a | |
1837 | * future version of eCryptfs. This function is here only for | |
1838 | * the purpose of providing a framework for other developers | |
1839 | * to easily implement filename encryption. Hint: Replace this | |
1840 | * memcpy() with a call to decode and decrypt the | |
1841 | * filename, the set the length accordingly. */ | |
1842 | memcpy((void *)(*decrypted_name), (void *)name, length); | |
1843 | (*decrypted_name)[length + 1] = '\0'; /* Only for convenience | |
1844 | * in printing out the | |
1845 | * string in debug | |
1846 | * messages */ | |
1847 | error = length; | |
1848 | out: | |
1849 | return error; | |
1850 | } | |
1851 | ||
1852 | /** | |
f4aad16a | 1853 | * ecryptfs_process_key_cipher - Perform key cipher initialization. |
237fead6 | 1854 | * @key_tfm: Crypto context for key material, set by this function |
e5d9cbde MH |
1855 | * @cipher_name: Name of the cipher |
1856 | * @key_size: Size of the key in bytes | |
237fead6 MH |
1857 | * |
1858 | * Returns zero on success. Any crypto_tfm structs allocated here | |
1859 | * should be released by other functions, such as on a superblock put | |
1860 | * event, regardless of whether this function succeeds for fails. | |
1861 | */ | |
1862 | int | |
f4aad16a MH |
1863 | ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm, |
1864 | char *cipher_name, size_t *key_size) | |
237fead6 MH |
1865 | { |
1866 | char dummy_key[ECRYPTFS_MAX_KEY_BYTES]; | |
8bba066f | 1867 | char *full_alg_name; |
237fead6 MH |
1868 | int rc; |
1869 | ||
e5d9cbde MH |
1870 | *key_tfm = NULL; |
1871 | if (*key_size > ECRYPTFS_MAX_KEY_BYTES) { | |
237fead6 MH |
1872 | rc = -EINVAL; |
1873 | printk(KERN_ERR "Requested key size is [%Zd] bytes; maximum " | |
e5d9cbde | 1874 | "allowable is [%d]\n", *key_size, ECRYPTFS_MAX_KEY_BYTES); |
237fead6 MH |
1875 | goto out; |
1876 | } | |
8bba066f MH |
1877 | rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, cipher_name, |
1878 | "ecb"); | |
1879 | if (rc) | |
1880 | goto out; | |
1881 | *key_tfm = crypto_alloc_blkcipher(full_alg_name, 0, CRYPTO_ALG_ASYNC); | |
1882 | kfree(full_alg_name); | |
1883 | if (IS_ERR(*key_tfm)) { | |
1884 | rc = PTR_ERR(*key_tfm); | |
237fead6 | 1885 | printk(KERN_ERR "Unable to allocate crypto cipher with name " |
8bba066f | 1886 | "[%s]; rc = [%d]\n", cipher_name, rc); |
237fead6 MH |
1887 | goto out; |
1888 | } | |
8bba066f MH |
1889 | crypto_blkcipher_set_flags(*key_tfm, CRYPTO_TFM_REQ_WEAK_KEY); |
1890 | if (*key_size == 0) { | |
1891 | struct blkcipher_alg *alg = crypto_blkcipher_alg(*key_tfm); | |
1892 | ||
1893 | *key_size = alg->max_keysize; | |
1894 | } | |
e5d9cbde | 1895 | get_random_bytes(dummy_key, *key_size); |
8bba066f | 1896 | rc = crypto_blkcipher_setkey(*key_tfm, dummy_key, *key_size); |
237fead6 MH |
1897 | if (rc) { |
1898 | printk(KERN_ERR "Error attempting to set key of size [%Zd] for " | |
e5d9cbde | 1899 | "cipher [%s]; rc = [%d]\n", *key_size, cipher_name, rc); |
237fead6 MH |
1900 | rc = -EINVAL; |
1901 | goto out; | |
1902 | } | |
1903 | out: | |
1904 | return rc; | |
1905 | } | |
f4aad16a MH |
1906 | |
1907 | struct kmem_cache *ecryptfs_key_tfm_cache; | |
1908 | struct list_head key_tfm_list; | |
1909 | struct mutex key_tfm_list_mutex; | |
1910 | ||
1911 | int ecryptfs_init_crypto(void) | |
1912 | { | |
1913 | mutex_init(&key_tfm_list_mutex); | |
1914 | INIT_LIST_HEAD(&key_tfm_list); | |
1915 | return 0; | |
1916 | } | |
1917 | ||
fcd12835 | 1918 | int ecryptfs_destroy_crypto(void) |
f4aad16a MH |
1919 | { |
1920 | struct ecryptfs_key_tfm *key_tfm, *key_tfm_tmp; | |
1921 | ||
1922 | mutex_lock(&key_tfm_list_mutex); | |
1923 | list_for_each_entry_safe(key_tfm, key_tfm_tmp, &key_tfm_list, | |
1924 | key_tfm_list) { | |
1925 | list_del(&key_tfm->key_tfm_list); | |
1926 | if (key_tfm->key_tfm) | |
1927 | crypto_free_blkcipher(key_tfm->key_tfm); | |
1928 | kmem_cache_free(ecryptfs_key_tfm_cache, key_tfm); | |
1929 | } | |
1930 | mutex_unlock(&key_tfm_list_mutex); | |
1931 | return 0; | |
1932 | } | |
1933 | ||
1934 | int | |
1935 | ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name, | |
1936 | size_t key_size) | |
1937 | { | |
1938 | struct ecryptfs_key_tfm *tmp_tfm; | |
1939 | int rc = 0; | |
1940 | ||
1941 | tmp_tfm = kmem_cache_alloc(ecryptfs_key_tfm_cache, GFP_KERNEL); | |
1942 | if (key_tfm != NULL) | |
1943 | (*key_tfm) = tmp_tfm; | |
1944 | if (!tmp_tfm) { | |
1945 | rc = -ENOMEM; | |
1946 | printk(KERN_ERR "Error attempting to allocate from " | |
1947 | "ecryptfs_key_tfm_cache\n"); | |
1948 | goto out; | |
1949 | } | |
1950 | mutex_init(&tmp_tfm->key_tfm_mutex); | |
1951 | strncpy(tmp_tfm->cipher_name, cipher_name, | |
1952 | ECRYPTFS_MAX_CIPHER_NAME_SIZE); | |
1953 | tmp_tfm->key_size = key_size; | |
1954 | if ((rc = ecryptfs_process_key_cipher(&tmp_tfm->key_tfm, | |
1955 | tmp_tfm->cipher_name, | |
1956 | &tmp_tfm->key_size))) { | |
1957 | printk(KERN_ERR "Error attempting to initialize key TFM " | |
1958 | "cipher with name = [%s]; rc = [%d]\n", | |
1959 | tmp_tfm->cipher_name, rc); | |
1960 | kmem_cache_free(ecryptfs_key_tfm_cache, tmp_tfm); | |
1961 | if (key_tfm != NULL) | |
1962 | (*key_tfm) = NULL; | |
1963 | goto out; | |
1964 | } | |
1965 | mutex_lock(&key_tfm_list_mutex); | |
1966 | list_add(&tmp_tfm->key_tfm_list, &key_tfm_list); | |
1967 | mutex_unlock(&key_tfm_list_mutex); | |
1968 | out: | |
1969 | return rc; | |
1970 | } | |
1971 | ||
1972 | int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm, | |
1973 | struct mutex **tfm_mutex, | |
1974 | char *cipher_name) | |
1975 | { | |
1976 | struct ecryptfs_key_tfm *key_tfm; | |
1977 | int rc = 0; | |
1978 | ||
1979 | (*tfm) = NULL; | |
1980 | (*tfm_mutex) = NULL; | |
1981 | mutex_lock(&key_tfm_list_mutex); | |
1982 | list_for_each_entry(key_tfm, &key_tfm_list, key_tfm_list) { | |
1983 | if (strcmp(key_tfm->cipher_name, cipher_name) == 0) { | |
1984 | (*tfm) = key_tfm->key_tfm; | |
1985 | (*tfm_mutex) = &key_tfm->key_tfm_mutex; | |
1986 | mutex_unlock(&key_tfm_list_mutex); | |
1987 | goto out; | |
1988 | } | |
1989 | } | |
1990 | mutex_unlock(&key_tfm_list_mutex); | |
1991 | if ((rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0))) { | |
1992 | printk(KERN_ERR "Error adding new key_tfm to list; rc = [%d]\n", | |
1993 | rc); | |
1994 | goto out; | |
1995 | } | |
1996 | (*tfm) = key_tfm->key_tfm; | |
1997 | (*tfm_mutex) = &key_tfm->key_tfm_mutex; | |
1998 | out: | |
1999 | return rc; | |
2000 | } |