Commit | Line | Data |
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237fead6 MH |
1 | /** |
2 | * eCryptfs: Linux filesystem encryption layer | |
3 | * | |
4 | * Copyright (C) 1997-2004 Erez Zadok | |
5 | * Copyright (C) 2001-2004 Stony Brook University | |
dd2a3b7a | 6 | * Copyright (C) 2004-2007 International Business Machines Corp. |
237fead6 MH |
7 | * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> |
8 | * Michael C. Thompson <mcthomps@us.ibm.com> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License as | |
12 | * published by the Free Software Foundation; either version 2 of the | |
13 | * License, or (at your option) any later version. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, but | |
16 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | * General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License | |
21 | * along with this program; if not, write to the Free Software | |
22 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
23 | * 02111-1307, USA. | |
24 | */ | |
25 | ||
26 | #include <linux/fs.h> | |
27 | #include <linux/mount.h> | |
28 | #include <linux/pagemap.h> | |
29 | #include <linux/random.h> | |
30 | #include <linux/compiler.h> | |
31 | #include <linux/key.h> | |
32 | #include <linux/namei.h> | |
33 | #include <linux/crypto.h> | |
34 | #include <linux/file.h> | |
35 | #include <linux/scatterlist.h> | |
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 | */ | |
a34f60f7 MH |
178 | int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat, |
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 | list_for_each_entry_safe(key_sig, key_sig_tmp, |
249 | &crypt_stat->keysig_list, crypt_stat_list) { | |
250 | list_del(&key_sig->crypt_stat_list); | |
251 | kmem_cache_free(ecryptfs_key_sig_cache, key_sig); | |
252 | } | |
237fead6 MH |
253 | memset(crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat)); |
254 | } | |
255 | ||
fcd12835 | 256 | void ecryptfs_destroy_mount_crypt_stat( |
237fead6 MH |
257 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) |
258 | { | |
f4aad16a MH |
259 | struct ecryptfs_global_auth_tok *auth_tok, *auth_tok_tmp; |
260 | ||
261 | if (!(mount_crypt_stat->flags & ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED)) | |
262 | return; | |
263 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
264 | list_for_each_entry_safe(auth_tok, auth_tok_tmp, | |
265 | &mount_crypt_stat->global_auth_tok_list, | |
266 | mount_crypt_stat_list) { | |
267 | list_del(&auth_tok->mount_crypt_stat_list); | |
268 | mount_crypt_stat->num_global_auth_toks--; | |
269 | if (auth_tok->global_auth_tok_key | |
270 | && !(auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID)) | |
271 | key_put(auth_tok->global_auth_tok_key); | |
272 | kmem_cache_free(ecryptfs_global_auth_tok_cache, auth_tok); | |
273 | } | |
274 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); | |
237fead6 MH |
275 | memset(mount_crypt_stat, 0, sizeof(struct ecryptfs_mount_crypt_stat)); |
276 | } | |
277 | ||
278 | /** | |
279 | * virt_to_scatterlist | |
280 | * @addr: Virtual address | |
281 | * @size: Size of data; should be an even multiple of the block size | |
282 | * @sg: Pointer to scatterlist array; set to NULL to obtain only | |
283 | * the number of scatterlist structs required in array | |
284 | * @sg_size: Max array size | |
285 | * | |
286 | * Fills in a scatterlist array with page references for a passed | |
287 | * virtual address. | |
288 | * | |
289 | * Returns the number of scatterlist structs in array used | |
290 | */ | |
291 | int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg, | |
292 | int sg_size) | |
293 | { | |
294 | int i = 0; | |
295 | struct page *pg; | |
296 | int offset; | |
297 | int remainder_of_page; | |
298 | ||
68e3f5dd HX |
299 | sg_init_table(sg, sg_size); |
300 | ||
237fead6 MH |
301 | while (size > 0 && i < sg_size) { |
302 | pg = virt_to_page(addr); | |
303 | offset = offset_in_page(addr); | |
642f1490 JA |
304 | if (sg) |
305 | sg_set_page(&sg[i], pg, 0, offset); | |
237fead6 MH |
306 | remainder_of_page = PAGE_CACHE_SIZE - offset; |
307 | if (size >= remainder_of_page) { | |
308 | if (sg) | |
309 | sg[i].length = remainder_of_page; | |
310 | addr += remainder_of_page; | |
311 | size -= remainder_of_page; | |
312 | } else { | |
313 | if (sg) | |
314 | sg[i].length = size; | |
315 | addr += size; | |
316 | size = 0; | |
317 | } | |
318 | i++; | |
319 | } | |
320 | if (size > 0) | |
321 | return -ENOMEM; | |
322 | return i; | |
323 | } | |
324 | ||
325 | /** | |
326 | * encrypt_scatterlist | |
327 | * @crypt_stat: Pointer to the crypt_stat struct to initialize. | |
328 | * @dest_sg: Destination of encrypted data | |
329 | * @src_sg: Data to be encrypted | |
330 | * @size: Length of data to be encrypted | |
331 | * @iv: iv to use during encryption | |
332 | * | |
333 | * Returns the number of bytes encrypted; negative value on error | |
334 | */ | |
335 | static int encrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, | |
336 | struct scatterlist *dest_sg, | |
337 | struct scatterlist *src_sg, int size, | |
338 | unsigned char *iv) | |
339 | { | |
8bba066f MH |
340 | struct blkcipher_desc desc = { |
341 | .tfm = crypt_stat->tfm, | |
342 | .info = iv, | |
343 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
344 | }; | |
237fead6 MH |
345 | int rc = 0; |
346 | ||
347 | BUG_ON(!crypt_stat || !crypt_stat->tfm | |
e2bd99ec | 348 | || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)); |
237fead6 MH |
349 | if (unlikely(ecryptfs_verbosity > 0)) { |
350 | ecryptfs_printk(KERN_DEBUG, "Key size [%d]; key:\n", | |
351 | crypt_stat->key_size); | |
352 | ecryptfs_dump_hex(crypt_stat->key, | |
353 | crypt_stat->key_size); | |
354 | } | |
355 | /* Consider doing this once, when the file is opened */ | |
356 | mutex_lock(&crypt_stat->cs_tfm_mutex); | |
8e3a6f16 TH |
357 | if (!(crypt_stat->flags & ECRYPTFS_KEY_SET)) { |
358 | rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key, | |
359 | crypt_stat->key_size); | |
360 | crypt_stat->flags |= ECRYPTFS_KEY_SET; | |
361 | } | |
237fead6 MH |
362 | if (rc) { |
363 | ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n", | |
364 | rc); | |
365 | mutex_unlock(&crypt_stat->cs_tfm_mutex); | |
366 | rc = -EINVAL; | |
367 | goto out; | |
368 | } | |
369 | ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes.\n", size); | |
8bba066f | 370 | crypto_blkcipher_encrypt_iv(&desc, dest_sg, src_sg, size); |
237fead6 MH |
371 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
372 | out: | |
373 | return rc; | |
374 | } | |
375 | ||
0216f7f7 MH |
376 | /** |
377 | * ecryptfs_lower_offset_for_extent | |
378 | * | |
379 | * Convert an eCryptfs page index into a lower byte offset | |
380 | */ | |
7896b631 AB |
381 | static void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num, |
382 | struct ecryptfs_crypt_stat *crypt_stat) | |
0216f7f7 | 383 | { |
cc11beff | 384 | (*offset) = (crypt_stat->num_header_bytes_at_front |
0216f7f7 MH |
385 | + (crypt_stat->extent_size * extent_num)); |
386 | } | |
387 | ||
388 | /** | |
389 | * ecryptfs_encrypt_extent | |
390 | * @enc_extent_page: Allocated page into which to encrypt the data in | |
391 | * @page | |
392 | * @crypt_stat: crypt_stat containing cryptographic context for the | |
393 | * encryption operation | |
394 | * @page: Page containing plaintext data extent to encrypt | |
395 | * @extent_offset: Page extent offset for use in generating IV | |
396 | * | |
397 | * Encrypts one extent of data. | |
398 | * | |
399 | * Return zero on success; non-zero otherwise | |
400 | */ | |
401 | static int ecryptfs_encrypt_extent(struct page *enc_extent_page, | |
402 | struct ecryptfs_crypt_stat *crypt_stat, | |
403 | struct page *page, | |
404 | unsigned long extent_offset) | |
405 | { | |
d6a13c17 | 406 | loff_t extent_base; |
0216f7f7 MH |
407 | char extent_iv[ECRYPTFS_MAX_IV_BYTES]; |
408 | int rc; | |
409 | ||
d6a13c17 | 410 | extent_base = (((loff_t)page->index) |
0216f7f7 MH |
411 | * (PAGE_CACHE_SIZE / crypt_stat->extent_size)); |
412 | rc = ecryptfs_derive_iv(extent_iv, crypt_stat, | |
413 | (extent_base + extent_offset)); | |
414 | if (rc) { | |
415 | ecryptfs_printk(KERN_ERR, "Error attempting to " | |
416 | "derive IV for extent [0x%.16x]; " | |
417 | "rc = [%d]\n", (extent_base + extent_offset), | |
418 | rc); | |
419 | goto out; | |
420 | } | |
421 | if (unlikely(ecryptfs_verbosity > 0)) { | |
422 | ecryptfs_printk(KERN_DEBUG, "Encrypting extent " | |
423 | "with iv:\n"); | |
424 | ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes); | |
425 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes before " | |
426 | "encryption:\n"); | |
427 | ecryptfs_dump_hex((char *) | |
428 | (page_address(page) | |
429 | + (extent_offset * crypt_stat->extent_size)), | |
430 | 8); | |
431 | } | |
432 | rc = ecryptfs_encrypt_page_offset(crypt_stat, enc_extent_page, 0, | |
433 | page, (extent_offset | |
434 | * crypt_stat->extent_size), | |
435 | crypt_stat->extent_size, extent_iv); | |
436 | if (rc < 0) { | |
437 | printk(KERN_ERR "%s: Error attempting to encrypt page with " | |
438 | "page->index = [%ld], extent_offset = [%ld]; " | |
18d1dbf1 | 439 | "rc = [%d]\n", __func__, page->index, extent_offset, |
0216f7f7 MH |
440 | rc); |
441 | goto out; | |
442 | } | |
443 | rc = 0; | |
444 | if (unlikely(ecryptfs_verbosity > 0)) { | |
445 | ecryptfs_printk(KERN_DEBUG, "Encrypt extent [0x%.16x]; " | |
446 | "rc = [%d]\n", (extent_base + extent_offset), | |
447 | rc); | |
448 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes after " | |
449 | "encryption:\n"); | |
450 | ecryptfs_dump_hex((char *)(page_address(enc_extent_page)), 8); | |
451 | } | |
452 | out: | |
453 | return rc; | |
454 | } | |
455 | ||
237fead6 MH |
456 | /** |
457 | * ecryptfs_encrypt_page | |
0216f7f7 MH |
458 | * @page: Page mapped from the eCryptfs inode for the file; contains |
459 | * decrypted content that needs to be encrypted (to a temporary | |
460 | * page; not in place) and written out to the lower file | |
237fead6 MH |
461 | * |
462 | * Encrypt an eCryptfs page. This is done on a per-extent basis. Note | |
463 | * that eCryptfs pages may straddle the lower pages -- for instance, | |
464 | * if the file was created on a machine with an 8K page size | |
465 | * (resulting in an 8K header), and then the file is copied onto a | |
466 | * host with a 32K page size, then when reading page 0 of the eCryptfs | |
467 | * file, 24K of page 0 of the lower file will be read and decrypted, | |
468 | * and then 8K of page 1 of the lower file will be read and decrypted. | |
469 | * | |
237fead6 MH |
470 | * Returns zero on success; negative on error |
471 | */ | |
0216f7f7 | 472 | int ecryptfs_encrypt_page(struct page *page) |
237fead6 | 473 | { |
0216f7f7 | 474 | struct inode *ecryptfs_inode; |
237fead6 | 475 | struct ecryptfs_crypt_stat *crypt_stat; |
7fcba054 ES |
476 | char *enc_extent_virt; |
477 | struct page *enc_extent_page = NULL; | |
0216f7f7 | 478 | loff_t extent_offset; |
237fead6 | 479 | int rc = 0; |
0216f7f7 MH |
480 | |
481 | ecryptfs_inode = page->mapping->host; | |
482 | crypt_stat = | |
483 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); | |
13a791b4 | 484 | BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)); |
7fcba054 ES |
485 | enc_extent_page = alloc_page(GFP_USER); |
486 | if (!enc_extent_page) { | |
0216f7f7 MH |
487 | rc = -ENOMEM; |
488 | ecryptfs_printk(KERN_ERR, "Error allocating memory for " | |
489 | "encrypted extent\n"); | |
490 | goto out; | |
491 | } | |
7fcba054 | 492 | enc_extent_virt = kmap(enc_extent_page); |
0216f7f7 MH |
493 | for (extent_offset = 0; |
494 | extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); | |
495 | extent_offset++) { | |
496 | loff_t offset; | |
497 | ||
498 | rc = ecryptfs_encrypt_extent(enc_extent_page, crypt_stat, page, | |
499 | extent_offset); | |
237fead6 | 500 | if (rc) { |
0216f7f7 | 501 | printk(KERN_ERR "%s: Error encrypting extent; " |
18d1dbf1 | 502 | "rc = [%d]\n", __func__, rc); |
237fead6 MH |
503 | goto out; |
504 | } | |
0216f7f7 | 505 | ecryptfs_lower_offset_for_extent( |
d6a13c17 MH |
506 | &offset, ((((loff_t)page->index) |
507 | * (PAGE_CACHE_SIZE | |
508 | / crypt_stat->extent_size)) | |
0216f7f7 MH |
509 | + extent_offset), crypt_stat); |
510 | rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt, | |
511 | offset, crypt_stat->extent_size); | |
96a7b9c2 | 512 | if (rc < 0) { |
0216f7f7 MH |
513 | ecryptfs_printk(KERN_ERR, "Error attempting " |
514 | "to write lower page; rc = [%d]" | |
515 | "\n", rc); | |
516 | goto out; | |
237fead6 | 517 | } |
237fead6 | 518 | } |
96a7b9c2 | 519 | rc = 0; |
0216f7f7 | 520 | out: |
7fcba054 ES |
521 | if (enc_extent_page) { |
522 | kunmap(enc_extent_page); | |
523 | __free_page(enc_extent_page); | |
524 | } | |
0216f7f7 MH |
525 | return rc; |
526 | } | |
527 | ||
528 | static int ecryptfs_decrypt_extent(struct page *page, | |
529 | struct ecryptfs_crypt_stat *crypt_stat, | |
530 | struct page *enc_extent_page, | |
531 | unsigned long extent_offset) | |
532 | { | |
d6a13c17 | 533 | loff_t extent_base; |
0216f7f7 MH |
534 | char extent_iv[ECRYPTFS_MAX_IV_BYTES]; |
535 | int rc; | |
536 | ||
d6a13c17 | 537 | extent_base = (((loff_t)page->index) |
0216f7f7 MH |
538 | * (PAGE_CACHE_SIZE / crypt_stat->extent_size)); |
539 | rc = ecryptfs_derive_iv(extent_iv, crypt_stat, | |
540 | (extent_base + extent_offset)); | |
237fead6 | 541 | if (rc) { |
0216f7f7 MH |
542 | ecryptfs_printk(KERN_ERR, "Error attempting to " |
543 | "derive IV for extent [0x%.16x]; " | |
544 | "rc = [%d]\n", (extent_base + extent_offset), | |
545 | rc); | |
546 | goto out; | |
547 | } | |
548 | if (unlikely(ecryptfs_verbosity > 0)) { | |
549 | ecryptfs_printk(KERN_DEBUG, "Decrypting extent " | |
550 | "with iv:\n"); | |
551 | ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes); | |
552 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes before " | |
553 | "decryption:\n"); | |
554 | ecryptfs_dump_hex((char *) | |
555 | (page_address(enc_extent_page) | |
556 | + (extent_offset * crypt_stat->extent_size)), | |
557 | 8); | |
558 | } | |
559 | rc = ecryptfs_decrypt_page_offset(crypt_stat, page, | |
560 | (extent_offset | |
561 | * crypt_stat->extent_size), | |
562 | enc_extent_page, 0, | |
563 | crypt_stat->extent_size, extent_iv); | |
564 | if (rc < 0) { | |
565 | printk(KERN_ERR "%s: Error attempting to decrypt to page with " | |
566 | "page->index = [%ld], extent_offset = [%ld]; " | |
18d1dbf1 | 567 | "rc = [%d]\n", __func__, page->index, extent_offset, |
0216f7f7 MH |
568 | rc); |
569 | goto out; | |
570 | } | |
571 | rc = 0; | |
572 | if (unlikely(ecryptfs_verbosity > 0)) { | |
573 | ecryptfs_printk(KERN_DEBUG, "Decrypt extent [0x%.16x]; " | |
574 | "rc = [%d]\n", (extent_base + extent_offset), | |
575 | rc); | |
576 | ecryptfs_printk(KERN_DEBUG, "First 8 bytes after " | |
577 | "decryption:\n"); | |
578 | ecryptfs_dump_hex((char *)(page_address(page) | |
579 | + (extent_offset | |
580 | * crypt_stat->extent_size)), 8); | |
237fead6 MH |
581 | } |
582 | out: | |
583 | return rc; | |
584 | } | |
585 | ||
586 | /** | |
587 | * ecryptfs_decrypt_page | |
0216f7f7 MH |
588 | * @page: Page mapped from the eCryptfs inode for the file; data read |
589 | * and decrypted from the lower file will be written into this | |
590 | * page | |
237fead6 MH |
591 | * |
592 | * Decrypt an eCryptfs page. This is done on a per-extent basis. Note | |
593 | * that eCryptfs pages may straddle the lower pages -- for instance, | |
594 | * if the file was created on a machine with an 8K page size | |
595 | * (resulting in an 8K header), and then the file is copied onto a | |
596 | * host with a 32K page size, then when reading page 0 of the eCryptfs | |
597 | * file, 24K of page 0 of the lower file will be read and decrypted, | |
598 | * and then 8K of page 1 of the lower file will be read and decrypted. | |
599 | * | |
600 | * Returns zero on success; negative on error | |
601 | */ | |
0216f7f7 | 602 | int ecryptfs_decrypt_page(struct page *page) |
237fead6 | 603 | { |
0216f7f7 | 604 | struct inode *ecryptfs_inode; |
237fead6 | 605 | struct ecryptfs_crypt_stat *crypt_stat; |
7fcba054 ES |
606 | char *enc_extent_virt; |
607 | struct page *enc_extent_page = NULL; | |
0216f7f7 | 608 | unsigned long extent_offset; |
237fead6 | 609 | int rc = 0; |
237fead6 | 610 | |
0216f7f7 MH |
611 | ecryptfs_inode = page->mapping->host; |
612 | crypt_stat = | |
613 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); | |
13a791b4 | 614 | BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)); |
7fcba054 ES |
615 | enc_extent_page = alloc_page(GFP_USER); |
616 | if (!enc_extent_page) { | |
237fead6 | 617 | rc = -ENOMEM; |
0216f7f7 MH |
618 | ecryptfs_printk(KERN_ERR, "Error allocating memory for " |
619 | "encrypted extent\n"); | |
16a72c45 | 620 | goto out; |
237fead6 | 621 | } |
7fcba054 | 622 | enc_extent_virt = kmap(enc_extent_page); |
0216f7f7 MH |
623 | for (extent_offset = 0; |
624 | extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); | |
625 | extent_offset++) { | |
626 | loff_t offset; | |
627 | ||
628 | ecryptfs_lower_offset_for_extent( | |
629 | &offset, ((page->index * (PAGE_CACHE_SIZE | |
630 | / crypt_stat->extent_size)) | |
631 | + extent_offset), crypt_stat); | |
632 | rc = ecryptfs_read_lower(enc_extent_virt, offset, | |
633 | crypt_stat->extent_size, | |
634 | ecryptfs_inode); | |
96a7b9c2 | 635 | if (rc < 0) { |
0216f7f7 MH |
636 | ecryptfs_printk(KERN_ERR, "Error attempting " |
637 | "to read lower page; rc = [%d]" | |
638 | "\n", rc); | |
16a72c45 | 639 | goto out; |
237fead6 | 640 | } |
0216f7f7 MH |
641 | rc = ecryptfs_decrypt_extent(page, crypt_stat, enc_extent_page, |
642 | extent_offset); | |
643 | if (rc) { | |
644 | printk(KERN_ERR "%s: Error encrypting extent; " | |
18d1dbf1 | 645 | "rc = [%d]\n", __func__, rc); |
16a72c45 | 646 | goto out; |
237fead6 | 647 | } |
237fead6 MH |
648 | } |
649 | out: | |
7fcba054 ES |
650 | if (enc_extent_page) { |
651 | kunmap(enc_extent_page); | |
652 | __free_page(enc_extent_page); | |
653 | } | |
237fead6 MH |
654 | return rc; |
655 | } | |
656 | ||
657 | /** | |
658 | * decrypt_scatterlist | |
22e78faf MH |
659 | * @crypt_stat: Cryptographic context |
660 | * @dest_sg: The destination scatterlist to decrypt into | |
661 | * @src_sg: The source scatterlist to decrypt from | |
662 | * @size: The number of bytes to decrypt | |
663 | * @iv: The initialization vector to use for the decryption | |
237fead6 MH |
664 | * |
665 | * Returns the number of bytes decrypted; negative value on error | |
666 | */ | |
667 | static int decrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, | |
668 | struct scatterlist *dest_sg, | |
669 | struct scatterlist *src_sg, int size, | |
670 | unsigned char *iv) | |
671 | { | |
8bba066f MH |
672 | struct blkcipher_desc desc = { |
673 | .tfm = crypt_stat->tfm, | |
674 | .info = iv, | |
675 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP | |
676 | }; | |
237fead6 MH |
677 | int rc = 0; |
678 | ||
679 | /* Consider doing this once, when the file is opened */ | |
680 | mutex_lock(&crypt_stat->cs_tfm_mutex); | |
8bba066f MH |
681 | rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key, |
682 | crypt_stat->key_size); | |
237fead6 MH |
683 | if (rc) { |
684 | ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n", | |
685 | rc); | |
686 | mutex_unlock(&crypt_stat->cs_tfm_mutex); | |
687 | rc = -EINVAL; | |
688 | goto out; | |
689 | } | |
690 | ecryptfs_printk(KERN_DEBUG, "Decrypting [%d] bytes.\n", size); | |
8bba066f | 691 | rc = crypto_blkcipher_decrypt_iv(&desc, dest_sg, src_sg, size); |
237fead6 MH |
692 | mutex_unlock(&crypt_stat->cs_tfm_mutex); |
693 | if (rc) { | |
694 | ecryptfs_printk(KERN_ERR, "Error decrypting; rc = [%d]\n", | |
695 | rc); | |
696 | goto out; | |
697 | } | |
698 | rc = size; | |
699 | out: | |
700 | return rc; | |
701 | } | |
702 | ||
703 | /** | |
704 | * ecryptfs_encrypt_page_offset | |
22e78faf MH |
705 | * @crypt_stat: The cryptographic context |
706 | * @dst_page: The page to encrypt into | |
707 | * @dst_offset: The offset in the page to encrypt into | |
708 | * @src_page: The page to encrypt from | |
709 | * @src_offset: The offset in the page to encrypt from | |
710 | * @size: The number of bytes to encrypt | |
711 | * @iv: The initialization vector to use for the encryption | |
237fead6 MH |
712 | * |
713 | * Returns the number of bytes encrypted | |
714 | */ | |
715 | static int | |
716 | ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
717 | struct page *dst_page, int dst_offset, | |
718 | struct page *src_page, int src_offset, int size, | |
719 | unsigned char *iv) | |
720 | { | |
721 | struct scatterlist src_sg, dst_sg; | |
722 | ||
60c74f81 JA |
723 | sg_init_table(&src_sg, 1); |
724 | sg_init_table(&dst_sg, 1); | |
725 | ||
642f1490 JA |
726 | sg_set_page(&src_sg, src_page, size, src_offset); |
727 | sg_set_page(&dst_sg, dst_page, size, dst_offset); | |
237fead6 MH |
728 | return encrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); |
729 | } | |
730 | ||
731 | /** | |
732 | * ecryptfs_decrypt_page_offset | |
22e78faf MH |
733 | * @crypt_stat: The cryptographic context |
734 | * @dst_page: The page to decrypt into | |
735 | * @dst_offset: The offset in the page to decrypt into | |
736 | * @src_page: The page to decrypt from | |
737 | * @src_offset: The offset in the page to decrypt from | |
738 | * @size: The number of bytes to decrypt | |
739 | * @iv: The initialization vector to use for the decryption | |
237fead6 MH |
740 | * |
741 | * Returns the number of bytes decrypted | |
742 | */ | |
743 | static int | |
744 | ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, | |
745 | struct page *dst_page, int dst_offset, | |
746 | struct page *src_page, int src_offset, int size, | |
747 | unsigned char *iv) | |
748 | { | |
749 | struct scatterlist src_sg, dst_sg; | |
750 | ||
60c74f81 | 751 | sg_init_table(&src_sg, 1); |
642f1490 JA |
752 | sg_set_page(&src_sg, src_page, size, src_offset); |
753 | ||
60c74f81 | 754 | sg_init_table(&dst_sg, 1); |
642f1490 | 755 | sg_set_page(&dst_sg, dst_page, size, dst_offset); |
60c74f81 | 756 | |
237fead6 MH |
757 | return decrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); |
758 | } | |
759 | ||
760 | #define ECRYPTFS_MAX_SCATTERLIST_LEN 4 | |
761 | ||
762 | /** | |
763 | * ecryptfs_init_crypt_ctx | |
764 | * @crypt_stat: Uninitilized crypt stats structure | |
765 | * | |
766 | * Initialize the crypto context. | |
767 | * | |
768 | * TODO: Performance: Keep a cache of initialized cipher contexts; | |
769 | * only init if needed | |
770 | */ | |
771 | int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat) | |
772 | { | |
8bba066f | 773 | char *full_alg_name; |
237fead6 MH |
774 | int rc = -EINVAL; |
775 | ||
776 | if (!crypt_stat->cipher) { | |
777 | ecryptfs_printk(KERN_ERR, "No cipher specified\n"); | |
778 | goto out; | |
779 | } | |
780 | ecryptfs_printk(KERN_DEBUG, | |
781 | "Initializing cipher [%s]; strlen = [%d]; " | |
782 | "key_size_bits = [%d]\n", | |
783 | crypt_stat->cipher, (int)strlen(crypt_stat->cipher), | |
784 | crypt_stat->key_size << 3); | |
785 | if (crypt_stat->tfm) { | |
786 | rc = 0; | |
787 | goto out; | |
788 | } | |
789 | mutex_lock(&crypt_stat->cs_tfm_mutex); | |
8bba066f MH |
790 | rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, |
791 | crypt_stat->cipher, "cbc"); | |
792 | if (rc) | |
c8161f64 | 793 | goto out_unlock; |
8bba066f MH |
794 | crypt_stat->tfm = crypto_alloc_blkcipher(full_alg_name, 0, |
795 | CRYPTO_ALG_ASYNC); | |
796 | kfree(full_alg_name); | |
de88777e AM |
797 | if (IS_ERR(crypt_stat->tfm)) { |
798 | rc = PTR_ERR(crypt_stat->tfm); | |
b0105eae | 799 | crypt_stat->tfm = NULL; |
237fead6 MH |
800 | ecryptfs_printk(KERN_ERR, "cryptfs: init_crypt_ctx(): " |
801 | "Error initializing cipher [%s]\n", | |
802 | crypt_stat->cipher); | |
c8161f64 | 803 | goto out_unlock; |
237fead6 | 804 | } |
f1ddcaf3 | 805 | crypto_blkcipher_set_flags(crypt_stat->tfm, CRYPTO_TFM_REQ_WEAK_KEY); |
237fead6 | 806 | rc = 0; |
c8161f64 ES |
807 | out_unlock: |
808 | mutex_unlock(&crypt_stat->cs_tfm_mutex); | |
237fead6 MH |
809 | out: |
810 | return rc; | |
811 | } | |
812 | ||
813 | static void set_extent_mask_and_shift(struct ecryptfs_crypt_stat *crypt_stat) | |
814 | { | |
815 | int extent_size_tmp; | |
816 | ||
817 | crypt_stat->extent_mask = 0xFFFFFFFF; | |
818 | crypt_stat->extent_shift = 0; | |
819 | if (crypt_stat->extent_size == 0) | |
820 | return; | |
821 | extent_size_tmp = crypt_stat->extent_size; | |
822 | while ((extent_size_tmp & 0x01) == 0) { | |
823 | extent_size_tmp >>= 1; | |
824 | crypt_stat->extent_mask <<= 1; | |
825 | crypt_stat->extent_shift++; | |
826 | } | |
827 | } | |
828 | ||
829 | void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat) | |
830 | { | |
831 | /* Default values; may be overwritten as we are parsing the | |
832 | * packets. */ | |
833 | crypt_stat->extent_size = ECRYPTFS_DEFAULT_EXTENT_SIZE; | |
834 | set_extent_mask_and_shift(crypt_stat); | |
835 | crypt_stat->iv_bytes = ECRYPTFS_DEFAULT_IV_BYTES; | |
dd2a3b7a | 836 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
cc11beff | 837 | crypt_stat->num_header_bytes_at_front = 0; |
45eaab79 MH |
838 | else { |
839 | if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE) | |
cc11beff MH |
840 | crypt_stat->num_header_bytes_at_front = |
841 | ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; | |
45eaab79 | 842 | else |
cc11beff | 843 | crypt_stat->num_header_bytes_at_front = PAGE_CACHE_SIZE; |
45eaab79 | 844 | } |
237fead6 MH |
845 | } |
846 | ||
847 | /** | |
848 | * ecryptfs_compute_root_iv | |
849 | * @crypt_stats | |
850 | * | |
851 | * On error, sets the root IV to all 0's. | |
852 | */ | |
853 | int ecryptfs_compute_root_iv(struct ecryptfs_crypt_stat *crypt_stat) | |
854 | { | |
855 | int rc = 0; | |
856 | char dst[MD5_DIGEST_SIZE]; | |
857 | ||
858 | BUG_ON(crypt_stat->iv_bytes > MD5_DIGEST_SIZE); | |
859 | BUG_ON(crypt_stat->iv_bytes <= 0); | |
e2bd99ec | 860 | if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { |
237fead6 MH |
861 | rc = -EINVAL; |
862 | ecryptfs_printk(KERN_WARNING, "Session key not valid; " | |
863 | "cannot generate root IV\n"); | |
864 | goto out; | |
865 | } | |
866 | rc = ecryptfs_calculate_md5(dst, crypt_stat, crypt_stat->key, | |
867 | crypt_stat->key_size); | |
868 | if (rc) { | |
869 | ecryptfs_printk(KERN_WARNING, "Error attempting to compute " | |
870 | "MD5 while generating root IV\n"); | |
871 | goto out; | |
872 | } | |
873 | memcpy(crypt_stat->root_iv, dst, crypt_stat->iv_bytes); | |
874 | out: | |
875 | if (rc) { | |
876 | memset(crypt_stat->root_iv, 0, crypt_stat->iv_bytes); | |
e2bd99ec | 877 | crypt_stat->flags |= ECRYPTFS_SECURITY_WARNING; |
237fead6 MH |
878 | } |
879 | return rc; | |
880 | } | |
881 | ||
882 | static void ecryptfs_generate_new_key(struct ecryptfs_crypt_stat *crypt_stat) | |
883 | { | |
884 | get_random_bytes(crypt_stat->key, crypt_stat->key_size); | |
e2bd99ec | 885 | crypt_stat->flags |= ECRYPTFS_KEY_VALID; |
237fead6 MH |
886 | ecryptfs_compute_root_iv(crypt_stat); |
887 | if (unlikely(ecryptfs_verbosity > 0)) { | |
888 | ecryptfs_printk(KERN_DEBUG, "Generated new session key:\n"); | |
889 | ecryptfs_dump_hex(crypt_stat->key, | |
890 | crypt_stat->key_size); | |
891 | } | |
892 | } | |
893 | ||
17398957 MH |
894 | /** |
895 | * ecryptfs_copy_mount_wide_flags_to_inode_flags | |
22e78faf MH |
896 | * @crypt_stat: The inode's cryptographic context |
897 | * @mount_crypt_stat: The mount point's cryptographic context | |
17398957 MH |
898 | * |
899 | * This function propagates the mount-wide flags to individual inode | |
900 | * flags. | |
901 | */ | |
902 | static void ecryptfs_copy_mount_wide_flags_to_inode_flags( | |
903 | struct ecryptfs_crypt_stat *crypt_stat, | |
904 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
905 | { | |
906 | if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) | |
907 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; | |
908 | if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) | |
909 | crypt_stat->flags |= ECRYPTFS_VIEW_AS_ENCRYPTED; | |
addd65ad MH |
910 | if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) { |
911 | crypt_stat->flags |= ECRYPTFS_ENCRYPT_FILENAMES; | |
912 | if (mount_crypt_stat->flags | |
913 | & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK) | |
914 | crypt_stat->flags |= ECRYPTFS_ENCFN_USE_MOUNT_FNEK; | |
915 | else if (mount_crypt_stat->flags | |
916 | & ECRYPTFS_GLOBAL_ENCFN_USE_FEK) | |
917 | crypt_stat->flags |= ECRYPTFS_ENCFN_USE_FEK; | |
918 | } | |
17398957 MH |
919 | } |
920 | ||
f4aad16a MH |
921 | static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs( |
922 | struct ecryptfs_crypt_stat *crypt_stat, | |
923 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
924 | { | |
925 | struct ecryptfs_global_auth_tok *global_auth_tok; | |
926 | int rc = 0; | |
927 | ||
aa06117f | 928 | mutex_lock(&crypt_stat->keysig_list_mutex); |
f4aad16a | 929 | mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); |
aa06117f | 930 | |
f4aad16a MH |
931 | list_for_each_entry(global_auth_tok, |
932 | &mount_crypt_stat->global_auth_tok_list, | |
933 | mount_crypt_stat_list) { | |
84814d64 TH |
934 | if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_FNEK) |
935 | continue; | |
f4aad16a MH |
936 | rc = ecryptfs_add_keysig(crypt_stat, global_auth_tok->sig); |
937 | if (rc) { | |
938 | printk(KERN_ERR "Error adding keysig; rc = [%d]\n", rc); | |
f4aad16a MH |
939 | goto out; |
940 | } | |
941 | } | |
aa06117f | 942 | |
f4aad16a | 943 | out: |
aa06117f RD |
944 | mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); |
945 | mutex_unlock(&crypt_stat->keysig_list_mutex); | |
f4aad16a MH |
946 | return rc; |
947 | } | |
948 | ||
237fead6 MH |
949 | /** |
950 | * ecryptfs_set_default_crypt_stat_vals | |
22e78faf MH |
951 | * @crypt_stat: The inode's cryptographic context |
952 | * @mount_crypt_stat: The mount point's cryptographic context | |
237fead6 MH |
953 | * |
954 | * Default values in the event that policy does not override them. | |
955 | */ | |
956 | static void ecryptfs_set_default_crypt_stat_vals( | |
957 | struct ecryptfs_crypt_stat *crypt_stat, | |
958 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
959 | { | |
17398957 MH |
960 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
961 | mount_crypt_stat); | |
237fead6 MH |
962 | ecryptfs_set_default_sizes(crypt_stat); |
963 | strcpy(crypt_stat->cipher, ECRYPTFS_DEFAULT_CIPHER); | |
964 | crypt_stat->key_size = ECRYPTFS_DEFAULT_KEY_BYTES; | |
e2bd99ec | 965 | crypt_stat->flags &= ~(ECRYPTFS_KEY_VALID); |
237fead6 MH |
966 | crypt_stat->file_version = ECRYPTFS_FILE_VERSION; |
967 | crypt_stat->mount_crypt_stat = mount_crypt_stat; | |
968 | } | |
969 | ||
970 | /** | |
971 | * ecryptfs_new_file_context | |
22e78faf | 972 | * @ecryptfs_dentry: The eCryptfs dentry |
237fead6 MH |
973 | * |
974 | * If the crypto context for the file has not yet been established, | |
975 | * this is where we do that. Establishing a new crypto context | |
976 | * involves the following decisions: | |
977 | * - What cipher to use? | |
978 | * - What set of authentication tokens to use? | |
979 | * Here we just worry about getting enough information into the | |
980 | * authentication tokens so that we know that they are available. | |
981 | * We associate the available authentication tokens with the new file | |
982 | * via the set of signatures in the crypt_stat struct. Later, when | |
983 | * the headers are actually written out, we may again defer to | |
984 | * userspace to perform the encryption of the session key; for the | |
985 | * foreseeable future, this will be the case with public key packets. | |
986 | * | |
987 | * Returns zero on success; non-zero otherwise | |
988 | */ | |
237fead6 MH |
989 | int ecryptfs_new_file_context(struct dentry *ecryptfs_dentry) |
990 | { | |
237fead6 MH |
991 | struct ecryptfs_crypt_stat *crypt_stat = |
992 | &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; | |
993 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = | |
994 | &ecryptfs_superblock_to_private( | |
995 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
996 | int cipher_name_len; | |
f4aad16a | 997 | int rc = 0; |
237fead6 MH |
998 | |
999 | ecryptfs_set_default_crypt_stat_vals(crypt_stat, mount_crypt_stat); | |
af655dc6 | 1000 | crypt_stat->flags |= (ECRYPTFS_ENCRYPTED | ECRYPTFS_KEY_VALID); |
f4aad16a MH |
1001 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
1002 | mount_crypt_stat); | |
1003 | rc = ecryptfs_copy_mount_wide_sigs_to_inode_sigs(crypt_stat, | |
1004 | mount_crypt_stat); | |
1005 | if (rc) { | |
1006 | printk(KERN_ERR "Error attempting to copy mount-wide key sigs " | |
1007 | "to the inode key sigs; rc = [%d]\n", rc); | |
1008 | goto out; | |
1009 | } | |
1010 | cipher_name_len = | |
1011 | strlen(mount_crypt_stat->global_default_cipher_name); | |
1012 | memcpy(crypt_stat->cipher, | |
1013 | mount_crypt_stat->global_default_cipher_name, | |
1014 | cipher_name_len); | |
1015 | crypt_stat->cipher[cipher_name_len] = '\0'; | |
1016 | crypt_stat->key_size = | |
1017 | mount_crypt_stat->global_default_cipher_key_size; | |
1018 | ecryptfs_generate_new_key(crypt_stat); | |
237fead6 MH |
1019 | rc = ecryptfs_init_crypt_ctx(crypt_stat); |
1020 | if (rc) | |
1021 | ecryptfs_printk(KERN_ERR, "Error initializing cryptographic " | |
1022 | "context for cipher [%s]: rc = [%d]\n", | |
1023 | crypt_stat->cipher, rc); | |
f4aad16a | 1024 | out: |
237fead6 MH |
1025 | return rc; |
1026 | } | |
1027 | ||
1028 | /** | |
1029 | * contains_ecryptfs_marker - check for the ecryptfs marker | |
1030 | * @data: The data block in which to check | |
1031 | * | |
1032 | * Returns one if marker found; zero if not found | |
1033 | */ | |
dd2a3b7a | 1034 | static int contains_ecryptfs_marker(char *data) |
237fead6 MH |
1035 | { |
1036 | u32 m_1, m_2; | |
1037 | ||
29335c6a HH |
1038 | m_1 = get_unaligned_be32(data); |
1039 | m_2 = get_unaligned_be32(data + 4); | |
237fead6 MH |
1040 | if ((m_1 ^ MAGIC_ECRYPTFS_MARKER) == m_2) |
1041 | return 1; | |
1042 | ecryptfs_printk(KERN_DEBUG, "m_1 = [0x%.8x]; m_2 = [0x%.8x]; " | |
1043 | "MAGIC_ECRYPTFS_MARKER = [0x%.8x]\n", m_1, m_2, | |
1044 | MAGIC_ECRYPTFS_MARKER); | |
1045 | ecryptfs_printk(KERN_DEBUG, "(m_1 ^ MAGIC_ECRYPTFS_MARKER) = " | |
1046 | "[0x%.8x]\n", (m_1 ^ MAGIC_ECRYPTFS_MARKER)); | |
1047 | return 0; | |
1048 | } | |
1049 | ||
1050 | struct ecryptfs_flag_map_elem { | |
1051 | u32 file_flag; | |
1052 | u32 local_flag; | |
1053 | }; | |
1054 | ||
1055 | /* Add support for additional flags by adding elements here. */ | |
1056 | static struct ecryptfs_flag_map_elem ecryptfs_flag_map[] = { | |
1057 | {0x00000001, ECRYPTFS_ENABLE_HMAC}, | |
dd2a3b7a | 1058 | {0x00000002, ECRYPTFS_ENCRYPTED}, |
addd65ad MH |
1059 | {0x00000004, ECRYPTFS_METADATA_IN_XATTR}, |
1060 | {0x00000008, ECRYPTFS_ENCRYPT_FILENAMES} | |
237fead6 MH |
1061 | }; |
1062 | ||
1063 | /** | |
1064 | * ecryptfs_process_flags | |
22e78faf | 1065 | * @crypt_stat: The cryptographic context |
237fead6 MH |
1066 | * @page_virt: Source data to be parsed |
1067 | * @bytes_read: Updated with the number of bytes read | |
1068 | * | |
1069 | * Returns zero on success; non-zero if the flag set is invalid | |
1070 | */ | |
1071 | static int ecryptfs_process_flags(struct ecryptfs_crypt_stat *crypt_stat, | |
1072 | char *page_virt, int *bytes_read) | |
1073 | { | |
1074 | int rc = 0; | |
1075 | int i; | |
1076 | u32 flags; | |
1077 | ||
29335c6a | 1078 | flags = get_unaligned_be32(page_virt); |
237fead6 MH |
1079 | for (i = 0; i < ((sizeof(ecryptfs_flag_map) |
1080 | / sizeof(struct ecryptfs_flag_map_elem))); i++) | |
1081 | if (flags & ecryptfs_flag_map[i].file_flag) { | |
e2bd99ec | 1082 | crypt_stat->flags |= ecryptfs_flag_map[i].local_flag; |
237fead6 | 1083 | } else |
e2bd99ec | 1084 | crypt_stat->flags &= ~(ecryptfs_flag_map[i].local_flag); |
237fead6 MH |
1085 | /* Version is in top 8 bits of the 32-bit flag vector */ |
1086 | crypt_stat->file_version = ((flags >> 24) & 0xFF); | |
1087 | (*bytes_read) = 4; | |
1088 | return rc; | |
1089 | } | |
1090 | ||
1091 | /** | |
1092 | * write_ecryptfs_marker | |
1093 | * @page_virt: The pointer to in a page to begin writing the marker | |
1094 | * @written: Number of bytes written | |
1095 | * | |
1096 | * Marker = 0x3c81b7f5 | |
1097 | */ | |
1098 | static void write_ecryptfs_marker(char *page_virt, size_t *written) | |
1099 | { | |
1100 | u32 m_1, m_2; | |
1101 | ||
1102 | get_random_bytes(&m_1, (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); | |
1103 | m_2 = (m_1 ^ MAGIC_ECRYPTFS_MARKER); | |
29335c6a HH |
1104 | put_unaligned_be32(m_1, page_virt); |
1105 | page_virt += (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2); | |
1106 | put_unaligned_be32(m_2, page_virt); | |
237fead6 MH |
1107 | (*written) = MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; |
1108 | } | |
1109 | ||
1110 | static void | |
1111 | write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat, | |
1112 | size_t *written) | |
1113 | { | |
1114 | u32 flags = 0; | |
1115 | int i; | |
1116 | ||
1117 | for (i = 0; i < ((sizeof(ecryptfs_flag_map) | |
1118 | / sizeof(struct ecryptfs_flag_map_elem))); i++) | |
e2bd99ec | 1119 | if (crypt_stat->flags & ecryptfs_flag_map[i].local_flag) |
237fead6 MH |
1120 | flags |= ecryptfs_flag_map[i].file_flag; |
1121 | /* Version is in top 8 bits of the 32-bit flag vector */ | |
1122 | flags |= ((((u8)crypt_stat->file_version) << 24) & 0xFF000000); | |
29335c6a | 1123 | put_unaligned_be32(flags, page_virt); |
237fead6 MH |
1124 | (*written) = 4; |
1125 | } | |
1126 | ||
1127 | struct ecryptfs_cipher_code_str_map_elem { | |
1128 | char cipher_str[16]; | |
19e66a67 | 1129 | u8 cipher_code; |
237fead6 MH |
1130 | }; |
1131 | ||
1132 | /* Add support for additional ciphers by adding elements here. The | |
1133 | * cipher_code is whatever OpenPGP applicatoins use to identify the | |
1134 | * ciphers. List in order of probability. */ | |
1135 | static struct ecryptfs_cipher_code_str_map_elem | |
1136 | ecryptfs_cipher_code_str_map[] = { | |
1137 | {"aes",RFC2440_CIPHER_AES_128 }, | |
1138 | {"blowfish", RFC2440_CIPHER_BLOWFISH}, | |
1139 | {"des3_ede", RFC2440_CIPHER_DES3_EDE}, | |
1140 | {"cast5", RFC2440_CIPHER_CAST_5}, | |
1141 | {"twofish", RFC2440_CIPHER_TWOFISH}, | |
1142 | {"cast6", RFC2440_CIPHER_CAST_6}, | |
1143 | {"aes", RFC2440_CIPHER_AES_192}, | |
1144 | {"aes", RFC2440_CIPHER_AES_256} | |
1145 | }; | |
1146 | ||
1147 | /** | |
1148 | * ecryptfs_code_for_cipher_string | |
9c79f34f MH |
1149 | * @cipher_name: The string alias for the cipher |
1150 | * @key_bytes: Length of key in bytes; used for AES code selection | |
237fead6 MH |
1151 | * |
1152 | * Returns zero on no match, or the cipher code on match | |
1153 | */ | |
9c79f34f | 1154 | u8 ecryptfs_code_for_cipher_string(char *cipher_name, size_t key_bytes) |
237fead6 MH |
1155 | { |
1156 | int i; | |
19e66a67 | 1157 | u8 code = 0; |
237fead6 MH |
1158 | struct ecryptfs_cipher_code_str_map_elem *map = |
1159 | ecryptfs_cipher_code_str_map; | |
1160 | ||
9c79f34f MH |
1161 | if (strcmp(cipher_name, "aes") == 0) { |
1162 | switch (key_bytes) { | |
237fead6 MH |
1163 | case 16: |
1164 | code = RFC2440_CIPHER_AES_128; | |
1165 | break; | |
1166 | case 24: | |
1167 | code = RFC2440_CIPHER_AES_192; | |
1168 | break; | |
1169 | case 32: | |
1170 | code = RFC2440_CIPHER_AES_256; | |
1171 | } | |
1172 | } else { | |
1173 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++) | |
9c79f34f | 1174 | if (strcmp(cipher_name, map[i].cipher_str) == 0) { |
237fead6 MH |
1175 | code = map[i].cipher_code; |
1176 | break; | |
1177 | } | |
1178 | } | |
1179 | return code; | |
1180 | } | |
1181 | ||
1182 | /** | |
1183 | * ecryptfs_cipher_code_to_string | |
1184 | * @str: Destination to write out the cipher name | |
1185 | * @cipher_code: The code to convert to cipher name string | |
1186 | * | |
1187 | * Returns zero on success | |
1188 | */ | |
19e66a67 | 1189 | int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code) |
237fead6 MH |
1190 | { |
1191 | int rc = 0; | |
1192 | int i; | |
1193 | ||
1194 | str[0] = '\0'; | |
1195 | for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++) | |
1196 | if (cipher_code == ecryptfs_cipher_code_str_map[i].cipher_code) | |
1197 | strcpy(str, ecryptfs_cipher_code_str_map[i].cipher_str); | |
1198 | if (str[0] == '\0') { | |
1199 | ecryptfs_printk(KERN_WARNING, "Cipher code not recognized: " | |
1200 | "[%d]\n", cipher_code); | |
1201 | rc = -EINVAL; | |
1202 | } | |
1203 | return rc; | |
1204 | } | |
1205 | ||
d7cdc5fe MH |
1206 | int ecryptfs_read_and_validate_header_region(char *data, |
1207 | struct inode *ecryptfs_inode) | |
dd2a3b7a | 1208 | { |
d7cdc5fe MH |
1209 | struct ecryptfs_crypt_stat *crypt_stat = |
1210 | &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); | |
dd2a3b7a MH |
1211 | int rc; |
1212 | ||
addd65ad MH |
1213 | if (crypt_stat->extent_size == 0) |
1214 | crypt_stat->extent_size = ECRYPTFS_DEFAULT_EXTENT_SIZE; | |
d7cdc5fe MH |
1215 | rc = ecryptfs_read_lower(data, 0, crypt_stat->extent_size, |
1216 | ecryptfs_inode); | |
96a7b9c2 | 1217 | if (rc < 0) { |
d7cdc5fe | 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; |
96a7b9c2 TH |
1224 | } else |
1225 | rc = 0; | |
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 | 1312 | static int |
8faece5f TH |
1313 | ecryptfs_write_metadata_to_contents(struct dentry *ecryptfs_dentry, |
1314 | char *virt, size_t virt_len) | |
dd2a3b7a | 1315 | { |
d7cdc5fe | 1316 | int rc; |
dd2a3b7a | 1317 | |
cc11beff | 1318 | rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, virt, |
8faece5f | 1319 | 0, virt_len); |
96a7b9c2 | 1320 | if (rc < 0) |
d7cdc5fe | 1321 | printk(KERN_ERR "%s: Error attempting to write header " |
96a7b9c2 TH |
1322 | "information to lower file; rc = [%d]\n", __func__, rc); |
1323 | else | |
1324 | rc = 0; | |
70456600 | 1325 | return rc; |
dd2a3b7a MH |
1326 | } |
1327 | ||
22e78faf MH |
1328 | static int |
1329 | ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, | |
22e78faf | 1330 | char *page_virt, size_t size) |
dd2a3b7a MH |
1331 | { |
1332 | int rc; | |
1333 | ||
1334 | rc = ecryptfs_setxattr(ecryptfs_dentry, ECRYPTFS_XATTR_NAME, page_virt, | |
1335 | size, 0); | |
237fead6 MH |
1336 | return rc; |
1337 | } | |
1338 | ||
8faece5f TH |
1339 | static unsigned long ecryptfs_get_zeroed_pages(gfp_t gfp_mask, |
1340 | unsigned int order) | |
1341 | { | |
1342 | struct page *page; | |
1343 | ||
1344 | page = alloc_pages(gfp_mask | __GFP_ZERO, order); | |
1345 | if (page) | |
1346 | return (unsigned long) page_address(page); | |
1347 | return 0; | |
1348 | } | |
1349 | ||
237fead6 | 1350 | /** |
dd2a3b7a | 1351 | * ecryptfs_write_metadata |
22e78faf | 1352 | * @ecryptfs_dentry: The eCryptfs dentry |
237fead6 MH |
1353 | * |
1354 | * Write the file headers out. This will likely involve a userspace | |
1355 | * callout, in which the session key is encrypted with one or more | |
1356 | * public keys and/or the passphrase necessary to do the encryption is | |
1357 | * retrieved via a prompt. Exactly what happens at this point should | |
1358 | * be policy-dependent. | |
1359 | * | |
1360 | * Returns zero on success; non-zero on error | |
1361 | */ | |
d7cdc5fe | 1362 | int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry) |
237fead6 | 1363 | { |
d7cdc5fe MH |
1364 | struct ecryptfs_crypt_stat *crypt_stat = |
1365 | &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; | |
8faece5f | 1366 | unsigned int order; |
cc11beff | 1367 | char *virt; |
8faece5f | 1368 | size_t virt_len; |
d7cdc5fe | 1369 | size_t size = 0; |
237fead6 MH |
1370 | int rc = 0; |
1371 | ||
e2bd99ec MH |
1372 | if (likely(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
1373 | if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { | |
d7cdc5fe | 1374 | printk(KERN_ERR "Key is invalid; bailing out\n"); |
237fead6 MH |
1375 | rc = -EINVAL; |
1376 | goto out; | |
1377 | } | |
1378 | } else { | |
cc11beff | 1379 | printk(KERN_WARNING "%s: Encrypted flag not set\n", |
18d1dbf1 | 1380 | __func__); |
237fead6 | 1381 | rc = -EINVAL; |
237fead6 MH |
1382 | goto out; |
1383 | } | |
8faece5f TH |
1384 | virt_len = crypt_stat->num_header_bytes_at_front; |
1385 | order = get_order(virt_len); | |
237fead6 | 1386 | /* Released in this function */ |
8faece5f | 1387 | virt = (char *)ecryptfs_get_zeroed_pages(GFP_KERNEL, order); |
cc11beff | 1388 | if (!virt) { |
18d1dbf1 | 1389 | printk(KERN_ERR "%s: Out of memory\n", __func__); |
237fead6 MH |
1390 | rc = -ENOMEM; |
1391 | goto out; | |
1392 | } | |
8faece5f TH |
1393 | rc = ecryptfs_write_headers_virt(virt, virt_len, &size, crypt_stat, |
1394 | ecryptfs_dentry); | |
237fead6 | 1395 | if (unlikely(rc)) { |
cc11beff | 1396 | printk(KERN_ERR "%s: Error whilst writing headers; rc = [%d]\n", |
18d1dbf1 | 1397 | __func__, rc); |
237fead6 MH |
1398 | goto out_free; |
1399 | } | |
dd2a3b7a | 1400 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
8faece5f TH |
1401 | rc = ecryptfs_write_metadata_to_xattr(ecryptfs_dentry, virt, |
1402 | size); | |
dd2a3b7a | 1403 | else |
8faece5f TH |
1404 | rc = ecryptfs_write_metadata_to_contents(ecryptfs_dentry, virt, |
1405 | virt_len); | |
dd2a3b7a | 1406 | if (rc) { |
cc11beff | 1407 | printk(KERN_ERR "%s: Error writing metadata out to lower file; " |
18d1dbf1 | 1408 | "rc = [%d]\n", __func__, rc); |
dd2a3b7a | 1409 | goto out_free; |
237fead6 | 1410 | } |
237fead6 | 1411 | out_free: |
8faece5f | 1412 | free_pages((unsigned long)virt, order); |
237fead6 MH |
1413 | out: |
1414 | return rc; | |
1415 | } | |
1416 | ||
dd2a3b7a MH |
1417 | #define ECRYPTFS_DONT_VALIDATE_HEADER_SIZE 0 |
1418 | #define ECRYPTFS_VALIDATE_HEADER_SIZE 1 | |
237fead6 | 1419 | static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat, |
dd2a3b7a MH |
1420 | char *virt, int *bytes_read, |
1421 | int validate_header_size) | |
237fead6 MH |
1422 | { |
1423 | int rc = 0; | |
1424 | u32 header_extent_size; | |
1425 | u16 num_header_extents_at_front; | |
1426 | ||
29335c6a HH |
1427 | header_extent_size = get_unaligned_be32(virt); |
1428 | virt += sizeof(__be32); | |
1429 | num_header_extents_at_front = get_unaligned_be16(virt); | |
cc11beff MH |
1430 | crypt_stat->num_header_bytes_at_front = |
1431 | (((size_t)num_header_extents_at_front | |
1432 | * (size_t)header_extent_size)); | |
29335c6a | 1433 | (*bytes_read) = (sizeof(__be32) + sizeof(__be16)); |
dd2a3b7a | 1434 | if ((validate_header_size == ECRYPTFS_VALIDATE_HEADER_SIZE) |
cc11beff | 1435 | && (crypt_stat->num_header_bytes_at_front |
dd2a3b7a | 1436 | < ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)) { |
237fead6 | 1437 | rc = -EINVAL; |
cc11beff MH |
1438 | printk(KERN_WARNING "Invalid header size: [%zd]\n", |
1439 | crypt_stat->num_header_bytes_at_front); | |
237fead6 MH |
1440 | } |
1441 | return rc; | |
1442 | } | |
1443 | ||
1444 | /** | |
1445 | * set_default_header_data | |
22e78faf | 1446 | * @crypt_stat: The cryptographic context |
237fead6 MH |
1447 | * |
1448 | * For version 0 file format; this function is only for backwards | |
1449 | * compatibility for files created with the prior versions of | |
1450 | * eCryptfs. | |
1451 | */ | |
1452 | static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat) | |
1453 | { | |
cc11beff MH |
1454 | crypt_stat->num_header_bytes_at_front = |
1455 | ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; | |
237fead6 MH |
1456 | } |
1457 | ||
1458 | /** | |
1459 | * ecryptfs_read_headers_virt | |
22e78faf MH |
1460 | * @page_virt: The virtual address into which to read the headers |
1461 | * @crypt_stat: The cryptographic context | |
1462 | * @ecryptfs_dentry: The eCryptfs dentry | |
1463 | * @validate_header_size: Whether to validate the header size while reading | |
237fead6 MH |
1464 | * |
1465 | * Read/parse the header data. The header format is detailed in the | |
1466 | * comment block for the ecryptfs_write_headers_virt() function. | |
1467 | * | |
1468 | * Returns zero on success | |
1469 | */ | |
1470 | static int ecryptfs_read_headers_virt(char *page_virt, | |
1471 | struct ecryptfs_crypt_stat *crypt_stat, | |
dd2a3b7a MH |
1472 | struct dentry *ecryptfs_dentry, |
1473 | int validate_header_size) | |
237fead6 MH |
1474 | { |
1475 | int rc = 0; | |
1476 | int offset; | |
1477 | int bytes_read; | |
1478 | ||
1479 | ecryptfs_set_default_sizes(crypt_stat); | |
1480 | crypt_stat->mount_crypt_stat = &ecryptfs_superblock_to_private( | |
1481 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
1482 | offset = ECRYPTFS_FILE_SIZE_BYTES; | |
1483 | rc = contains_ecryptfs_marker(page_virt + offset); | |
1484 | if (rc == 0) { | |
1485 | rc = -EINVAL; | |
1486 | goto out; | |
1487 | } | |
1488 | offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; | |
1489 | rc = ecryptfs_process_flags(crypt_stat, (page_virt + offset), | |
1490 | &bytes_read); | |
1491 | if (rc) { | |
1492 | ecryptfs_printk(KERN_WARNING, "Error processing flags\n"); | |
1493 | goto out; | |
1494 | } | |
1495 | if (crypt_stat->file_version > ECRYPTFS_SUPPORTED_FILE_VERSION) { | |
1496 | ecryptfs_printk(KERN_WARNING, "File version is [%d]; only " | |
1497 | "file version [%d] is supported by this " | |
1498 | "version of eCryptfs\n", | |
1499 | crypt_stat->file_version, | |
1500 | ECRYPTFS_SUPPORTED_FILE_VERSION); | |
1501 | rc = -EINVAL; | |
1502 | goto out; | |
1503 | } | |
1504 | offset += bytes_read; | |
1505 | if (crypt_stat->file_version >= 1) { | |
1506 | rc = parse_header_metadata(crypt_stat, (page_virt + offset), | |
dd2a3b7a | 1507 | &bytes_read, validate_header_size); |
237fead6 MH |
1508 | if (rc) { |
1509 | ecryptfs_printk(KERN_WARNING, "Error reading header " | |
1510 | "metadata; rc = [%d]\n", rc); | |
1511 | } | |
1512 | offset += bytes_read; | |
1513 | } else | |
1514 | set_default_header_data(crypt_stat); | |
1515 | rc = ecryptfs_parse_packet_set(crypt_stat, (page_virt + offset), | |
1516 | ecryptfs_dentry); | |
1517 | out: | |
1518 | return rc; | |
1519 | } | |
1520 | ||
1521 | /** | |
dd2a3b7a | 1522 | * ecryptfs_read_xattr_region |
22e78faf | 1523 | * @page_virt: The vitual address into which to read the xattr data |
2ed92554 | 1524 | * @ecryptfs_inode: The eCryptfs inode |
dd2a3b7a MH |
1525 | * |
1526 | * Attempts to read the crypto metadata from the extended attribute | |
1527 | * region of the lower file. | |
22e78faf MH |
1528 | * |
1529 | * Returns zero on success; non-zero on error | |
dd2a3b7a | 1530 | */ |
d7cdc5fe | 1531 | int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode) |
dd2a3b7a | 1532 | { |
d7cdc5fe MH |
1533 | struct dentry *lower_dentry = |
1534 | ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry; | |
dd2a3b7a MH |
1535 | ssize_t size; |
1536 | int rc = 0; | |
1537 | ||
d7cdc5fe MH |
1538 | size = ecryptfs_getxattr_lower(lower_dentry, ECRYPTFS_XATTR_NAME, |
1539 | page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE); | |
dd2a3b7a | 1540 | if (size < 0) { |
25bd8174 MH |
1541 | if (unlikely(ecryptfs_verbosity > 0)) |
1542 | printk(KERN_INFO "Error attempting to read the [%s] " | |
1543 | "xattr from the lower file; return value = " | |
1544 | "[%zd]\n", ECRYPTFS_XATTR_NAME, size); | |
dd2a3b7a MH |
1545 | rc = -EINVAL; |
1546 | goto out; | |
1547 | } | |
1548 | out: | |
1549 | return rc; | |
1550 | } | |
1551 | ||
1552 | int ecryptfs_read_and_validate_xattr_region(char *page_virt, | |
1553 | struct dentry *ecryptfs_dentry) | |
1554 | { | |
1555 | int rc; | |
1556 | ||
d7cdc5fe | 1557 | rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry->d_inode); |
dd2a3b7a MH |
1558 | if (rc) |
1559 | goto out; | |
1560 | if (!contains_ecryptfs_marker(page_virt + ECRYPTFS_FILE_SIZE_BYTES)) { | |
1561 | printk(KERN_WARNING "Valid data found in [%s] xattr, but " | |
1562 | "the marker is invalid\n", ECRYPTFS_XATTR_NAME); | |
1563 | rc = -EINVAL; | |
1564 | } | |
1565 | out: | |
1566 | return rc; | |
1567 | } | |
1568 | ||
1569 | /** | |
1570 | * ecryptfs_read_metadata | |
1571 | * | |
1572 | * Common entry point for reading file metadata. From here, we could | |
1573 | * retrieve the header information from the header region of the file, | |
1574 | * the xattr region of the file, or some other repostory that is | |
1575 | * stored separately from the file itself. The current implementation | |
1576 | * supports retrieving the metadata information from the file contents | |
1577 | * and from the xattr region. | |
237fead6 MH |
1578 | * |
1579 | * Returns zero if valid headers found and parsed; non-zero otherwise | |
1580 | */ | |
d7cdc5fe | 1581 | int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry) |
237fead6 MH |
1582 | { |
1583 | int rc = 0; | |
1584 | char *page_virt = NULL; | |
d7cdc5fe | 1585 | struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode; |
237fead6 | 1586 | struct ecryptfs_crypt_stat *crypt_stat = |
d7cdc5fe | 1587 | &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
e77a56dd MH |
1588 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
1589 | &ecryptfs_superblock_to_private( | |
1590 | ecryptfs_dentry->d_sb)->mount_crypt_stat; | |
237fead6 | 1591 | |
e77a56dd MH |
1592 | ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, |
1593 | mount_crypt_stat); | |
237fead6 | 1594 | /* Read the first page from the underlying file */ |
f7267c0c | 1595 | page_virt = kmem_cache_alloc(ecryptfs_header_cache_1, GFP_USER); |
237fead6 MH |
1596 | if (!page_virt) { |
1597 | rc = -ENOMEM; | |
d7cdc5fe | 1598 | printk(KERN_ERR "%s: Unable to allocate page_virt\n", |
18d1dbf1 | 1599 | __func__); |
237fead6 MH |
1600 | goto out; |
1601 | } | |
d7cdc5fe MH |
1602 | rc = ecryptfs_read_lower(page_virt, 0, crypt_stat->extent_size, |
1603 | ecryptfs_inode); | |
96a7b9c2 | 1604 | if (rc >= 0) |
d7cdc5fe MH |
1605 | rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, |
1606 | ecryptfs_dentry, | |
1607 | ECRYPTFS_VALIDATE_HEADER_SIZE); | |
237fead6 | 1608 | if (rc) { |
d7cdc5fe | 1609 | rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode); |
dd2a3b7a MH |
1610 | if (rc) { |
1611 | printk(KERN_DEBUG "Valid eCryptfs headers not found in " | |
1612 | "file header region or xattr region\n"); | |
1613 | rc = -EINVAL; | |
1614 | goto out; | |
1615 | } | |
1616 | rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, | |
1617 | ecryptfs_dentry, | |
1618 | ECRYPTFS_DONT_VALIDATE_HEADER_SIZE); | |
1619 | if (rc) { | |
1620 | printk(KERN_DEBUG "Valid eCryptfs headers not found in " | |
1621 | "file xattr region either\n"); | |
1622 | rc = -EINVAL; | |
1623 | } | |
1624 | if (crypt_stat->mount_crypt_stat->flags | |
1625 | & ECRYPTFS_XATTR_METADATA_ENABLED) { | |
1626 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; | |
1627 | } else { | |
1628 | printk(KERN_WARNING "Attempt to access file with " | |
1629 | "crypto metadata only in the extended attribute " | |
1630 | "region, but eCryptfs was mounted without " | |
1631 | "xattr support enabled. eCryptfs will not treat " | |
1632 | "this like an encrypted file.\n"); | |
1633 | rc = -EINVAL; | |
1634 | } | |
237fead6 MH |
1635 | } |
1636 | out: | |
1637 | if (page_virt) { | |
1638 | memset(page_virt, 0, PAGE_CACHE_SIZE); | |
1639 | kmem_cache_free(ecryptfs_header_cache_1, page_virt); | |
1640 | } | |
1641 | return rc; | |
1642 | } | |
1643 | ||
51ca58dc MH |
1644 | /** |
1645 | * ecryptfs_encrypt_filename - encrypt filename | |
1646 | * | |
1647 | * CBC-encrypts the filename. We do not want to encrypt the same | |
1648 | * filename with the same key and IV, which may happen with hard | |
1649 | * links, so we prepend random bits to each filename. | |
1650 | * | |
1651 | * Returns zero on success; non-zero otherwise | |
1652 | */ | |
1653 | static int | |
1654 | ecryptfs_encrypt_filename(struct ecryptfs_filename *filename, | |
1655 | struct ecryptfs_crypt_stat *crypt_stat, | |
1656 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat) | |
1657 | { | |
1658 | int rc = 0; | |
1659 | ||
1660 | filename->encrypted_filename = NULL; | |
1661 | filename->encrypted_filename_size = 0; | |
1662 | if ((crypt_stat && (crypt_stat->flags & ECRYPTFS_ENCFN_USE_MOUNT_FNEK)) | |
1663 | || (mount_crypt_stat && (mount_crypt_stat->flags | |
1664 | & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK))) { | |
1665 | size_t packet_size; | |
1666 | size_t remaining_bytes; | |
1667 | ||
1668 | rc = ecryptfs_write_tag_70_packet( | |
1669 | NULL, NULL, | |
1670 | &filename->encrypted_filename_size, | |
1671 | mount_crypt_stat, NULL, | |
1672 | filename->filename_size); | |
1673 | if (rc) { | |
1674 | printk(KERN_ERR "%s: Error attempting to get packet " | |
1675 | "size for tag 72; rc = [%d]\n", __func__, | |
1676 | rc); | |
1677 | filename->encrypted_filename_size = 0; | |
1678 | goto out; | |
1679 | } | |
1680 | filename->encrypted_filename = | |
1681 | kmalloc(filename->encrypted_filename_size, GFP_KERNEL); | |
1682 | if (!filename->encrypted_filename) { | |
1683 | printk(KERN_ERR "%s: Out of memory whilst attempting " | |
df261c52 | 1684 | "to kmalloc [%zd] bytes\n", __func__, |
51ca58dc MH |
1685 | filename->encrypted_filename_size); |
1686 | rc = -ENOMEM; | |
1687 | goto out; | |
1688 | } | |
1689 | remaining_bytes = filename->encrypted_filename_size; | |
1690 | rc = ecryptfs_write_tag_70_packet(filename->encrypted_filename, | |
1691 | &remaining_bytes, | |
1692 | &packet_size, | |
1693 | mount_crypt_stat, | |
1694 | filename->filename, | |
1695 | filename->filename_size); | |
1696 | if (rc) { | |
1697 | printk(KERN_ERR "%s: Error attempting to generate " | |
1698 | "tag 70 packet; rc = [%d]\n", __func__, | |
1699 | rc); | |
1700 | kfree(filename->encrypted_filename); | |
1701 | filename->encrypted_filename = NULL; | |
1702 | filename->encrypted_filename_size = 0; | |
1703 | goto out; | |
1704 | } | |
1705 | filename->encrypted_filename_size = packet_size; | |
1706 | } else { | |
1707 | printk(KERN_ERR "%s: No support for requested filename " | |
1708 | "encryption method in this release\n", __func__); | |
df6ad33b | 1709 | rc = -EOPNOTSUPP; |
51ca58dc MH |
1710 | goto out; |
1711 | } | |
1712 | out: | |
1713 | return rc; | |
1714 | } | |
1715 | ||
1716 | static int ecryptfs_copy_filename(char **copied_name, size_t *copied_name_size, | |
1717 | const char *name, size_t name_size) | |
1718 | { | |
1719 | int rc = 0; | |
1720 | ||
fd9fc842 | 1721 | (*copied_name) = kmalloc((name_size + 1), GFP_KERNEL); |
51ca58dc MH |
1722 | if (!(*copied_name)) { |
1723 | rc = -ENOMEM; | |
1724 | goto out; | |
1725 | } | |
1726 | memcpy((void *)(*copied_name), (void *)name, name_size); | |
1727 | (*copied_name)[(name_size)] = '\0'; /* Only for convenience | |
1728 | * in printing out the | |
1729 | * string in debug | |
1730 | * messages */ | |
fd9fc842 | 1731 | (*copied_name_size) = name_size; |
51ca58dc MH |
1732 | out: |
1733 | return rc; | |
1734 | } | |
1735 | ||
237fead6 | 1736 | /** |
f4aad16a | 1737 | * ecryptfs_process_key_cipher - Perform key cipher initialization. |
237fead6 | 1738 | * @key_tfm: Crypto context for key material, set by this function |
e5d9cbde MH |
1739 | * @cipher_name: Name of the cipher |
1740 | * @key_size: Size of the key in bytes | |
237fead6 MH |
1741 | * |
1742 | * Returns zero on success. Any crypto_tfm structs allocated here | |
1743 | * should be released by other functions, such as on a superblock put | |
1744 | * event, regardless of whether this function succeeds for fails. | |
1745 | */ | |
cd9d67df | 1746 | static int |
f4aad16a MH |
1747 | ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm, |
1748 | char *cipher_name, size_t *key_size) | |
237fead6 MH |
1749 | { |
1750 | char dummy_key[ECRYPTFS_MAX_KEY_BYTES]; | |
8bba066f | 1751 | char *full_alg_name; |
237fead6 MH |
1752 | int rc; |
1753 | ||
e5d9cbde MH |
1754 | *key_tfm = NULL; |
1755 | if (*key_size > ECRYPTFS_MAX_KEY_BYTES) { | |
237fead6 | 1756 | rc = -EINVAL; |
df261c52 | 1757 | printk(KERN_ERR "Requested key size is [%zd] bytes; maximum " |
e5d9cbde | 1758 | "allowable is [%d]\n", *key_size, ECRYPTFS_MAX_KEY_BYTES); |
237fead6 MH |
1759 | goto out; |
1760 | } | |
8bba066f MH |
1761 | rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, cipher_name, |
1762 | "ecb"); | |
1763 | if (rc) | |
1764 | goto out; | |
1765 | *key_tfm = crypto_alloc_blkcipher(full_alg_name, 0, CRYPTO_ALG_ASYNC); | |
1766 | kfree(full_alg_name); | |
1767 | if (IS_ERR(*key_tfm)) { | |
1768 | rc = PTR_ERR(*key_tfm); | |
237fead6 | 1769 | printk(KERN_ERR "Unable to allocate crypto cipher with name " |
38268498 | 1770 | "[%s]; rc = [%d]\n", full_alg_name, rc); |
237fead6 MH |
1771 | goto out; |
1772 | } | |
8bba066f MH |
1773 | crypto_blkcipher_set_flags(*key_tfm, CRYPTO_TFM_REQ_WEAK_KEY); |
1774 | if (*key_size == 0) { | |
1775 | struct blkcipher_alg *alg = crypto_blkcipher_alg(*key_tfm); | |
1776 | ||
1777 | *key_size = alg->max_keysize; | |
1778 | } | |
e5d9cbde | 1779 | get_random_bytes(dummy_key, *key_size); |
8bba066f | 1780 | rc = crypto_blkcipher_setkey(*key_tfm, dummy_key, *key_size); |
237fead6 | 1781 | if (rc) { |
df261c52 | 1782 | printk(KERN_ERR "Error attempting to set key of size [%zd] for " |
38268498 DH |
1783 | "cipher [%s]; rc = [%d]\n", *key_size, full_alg_name, |
1784 | rc); | |
237fead6 MH |
1785 | rc = -EINVAL; |
1786 | goto out; | |
1787 | } | |
1788 | out: | |
1789 | return rc; | |
1790 | } | |
f4aad16a MH |
1791 | |
1792 | struct kmem_cache *ecryptfs_key_tfm_cache; | |
7896b631 | 1793 | static struct list_head key_tfm_list; |
af440f52 | 1794 | struct mutex key_tfm_list_mutex; |
f4aad16a MH |
1795 | |
1796 | int ecryptfs_init_crypto(void) | |
1797 | { | |
1798 | mutex_init(&key_tfm_list_mutex); | |
1799 | INIT_LIST_HEAD(&key_tfm_list); | |
1800 | return 0; | |
1801 | } | |
1802 | ||
af440f52 ES |
1803 | /** |
1804 | * ecryptfs_destroy_crypto - free all cached key_tfms on key_tfm_list | |
1805 | * | |
1806 | * Called only at module unload time | |
1807 | */ | |
fcd12835 | 1808 | int ecryptfs_destroy_crypto(void) |
f4aad16a MH |
1809 | { |
1810 | struct ecryptfs_key_tfm *key_tfm, *key_tfm_tmp; | |
1811 | ||
1812 | mutex_lock(&key_tfm_list_mutex); | |
1813 | list_for_each_entry_safe(key_tfm, key_tfm_tmp, &key_tfm_list, | |
1814 | key_tfm_list) { | |
1815 | list_del(&key_tfm->key_tfm_list); | |
1816 | if (key_tfm->key_tfm) | |
1817 | crypto_free_blkcipher(key_tfm->key_tfm); | |
1818 | kmem_cache_free(ecryptfs_key_tfm_cache, key_tfm); | |
1819 | } | |
1820 | mutex_unlock(&key_tfm_list_mutex); | |
1821 | return 0; | |
1822 | } | |
1823 | ||
1824 | int | |
1825 | ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name, | |
1826 | size_t key_size) | |
1827 | { | |
1828 | struct ecryptfs_key_tfm *tmp_tfm; | |
1829 | int rc = 0; | |
1830 | ||
af440f52 ES |
1831 | BUG_ON(!mutex_is_locked(&key_tfm_list_mutex)); |
1832 | ||
f4aad16a MH |
1833 | tmp_tfm = kmem_cache_alloc(ecryptfs_key_tfm_cache, GFP_KERNEL); |
1834 | if (key_tfm != NULL) | |
1835 | (*key_tfm) = tmp_tfm; | |
1836 | if (!tmp_tfm) { | |
1837 | rc = -ENOMEM; | |
1838 | printk(KERN_ERR "Error attempting to allocate from " | |
1839 | "ecryptfs_key_tfm_cache\n"); | |
1840 | goto out; | |
1841 | } | |
1842 | mutex_init(&tmp_tfm->key_tfm_mutex); | |
1843 | strncpy(tmp_tfm->cipher_name, cipher_name, | |
1844 | ECRYPTFS_MAX_CIPHER_NAME_SIZE); | |
b8862906 | 1845 | tmp_tfm->cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; |
f4aad16a | 1846 | tmp_tfm->key_size = key_size; |
5dda6992 MH |
1847 | rc = ecryptfs_process_key_cipher(&tmp_tfm->key_tfm, |
1848 | tmp_tfm->cipher_name, | |
1849 | &tmp_tfm->key_size); | |
1850 | if (rc) { | |
f4aad16a MH |
1851 | printk(KERN_ERR "Error attempting to initialize key TFM " |
1852 | "cipher with name = [%s]; rc = [%d]\n", | |
1853 | tmp_tfm->cipher_name, rc); | |
1854 | kmem_cache_free(ecryptfs_key_tfm_cache, tmp_tfm); | |
1855 | if (key_tfm != NULL) | |
1856 | (*key_tfm) = NULL; | |
1857 | goto out; | |
1858 | } | |
f4aad16a | 1859 | list_add(&tmp_tfm->key_tfm_list, &key_tfm_list); |
f4aad16a MH |
1860 | out: |
1861 | return rc; | |
1862 | } | |
1863 | ||
af440f52 ES |
1864 | /** |
1865 | * ecryptfs_tfm_exists - Search for existing tfm for cipher_name. | |
1866 | * @cipher_name: the name of the cipher to search for | |
1867 | * @key_tfm: set to corresponding tfm if found | |
1868 | * | |
1869 | * Searches for cached key_tfm matching @cipher_name | |
1870 | * Must be called with &key_tfm_list_mutex held | |
1871 | * Returns 1 if found, with @key_tfm set | |
1872 | * Returns 0 if not found, with @key_tfm set to NULL | |
1873 | */ | |
1874 | int ecryptfs_tfm_exists(char *cipher_name, struct ecryptfs_key_tfm **key_tfm) | |
1875 | { | |
1876 | struct ecryptfs_key_tfm *tmp_key_tfm; | |
1877 | ||
1878 | BUG_ON(!mutex_is_locked(&key_tfm_list_mutex)); | |
1879 | ||
1880 | list_for_each_entry(tmp_key_tfm, &key_tfm_list, key_tfm_list) { | |
1881 | if (strcmp(tmp_key_tfm->cipher_name, cipher_name) == 0) { | |
1882 | if (key_tfm) | |
1883 | (*key_tfm) = tmp_key_tfm; | |
1884 | return 1; | |
1885 | } | |
1886 | } | |
1887 | if (key_tfm) | |
1888 | (*key_tfm) = NULL; | |
1889 | return 0; | |
1890 | } | |
1891 | ||
1892 | /** | |
1893 | * ecryptfs_get_tfm_and_mutex_for_cipher_name | |
1894 | * | |
1895 | * @tfm: set to cached tfm found, or new tfm created | |
1896 | * @tfm_mutex: set to mutex for cached tfm found, or new tfm created | |
1897 | * @cipher_name: the name of the cipher to search for and/or add | |
1898 | * | |
1899 | * Sets pointers to @tfm & @tfm_mutex matching @cipher_name. | |
1900 | * Searches for cached item first, and creates new if not found. | |
1901 | * Returns 0 on success, non-zero if adding new cipher failed | |
1902 | */ | |
f4aad16a MH |
1903 | int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm, |
1904 | struct mutex **tfm_mutex, | |
1905 | char *cipher_name) | |
1906 | { | |
1907 | struct ecryptfs_key_tfm *key_tfm; | |
1908 | int rc = 0; | |
1909 | ||
1910 | (*tfm) = NULL; | |
1911 | (*tfm_mutex) = NULL; | |
af440f52 | 1912 | |
f4aad16a | 1913 | mutex_lock(&key_tfm_list_mutex); |
af440f52 ES |
1914 | if (!ecryptfs_tfm_exists(cipher_name, &key_tfm)) { |
1915 | rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0); | |
1916 | if (rc) { | |
1917 | printk(KERN_ERR "Error adding new key_tfm to list; " | |
1918 | "rc = [%d]\n", rc); | |
f4aad16a MH |
1919 | goto out; |
1920 | } | |
1921 | } | |
f4aad16a MH |
1922 | (*tfm) = key_tfm->key_tfm; |
1923 | (*tfm_mutex) = &key_tfm->key_tfm_mutex; | |
1924 | out: | |
71fd5179 | 1925 | mutex_unlock(&key_tfm_list_mutex); |
f4aad16a MH |
1926 | return rc; |
1927 | } | |
51ca58dc MH |
1928 | |
1929 | /* 64 characters forming a 6-bit target field */ | |
1930 | static unsigned char *portable_filename_chars = ("-.0123456789ABCD" | |
1931 | "EFGHIJKLMNOPQRST" | |
1932 | "UVWXYZabcdefghij" | |
1933 | "klmnopqrstuvwxyz"); | |
1934 | ||
1935 | /* We could either offset on every reverse map or just pad some 0x00's | |
1936 | * at the front here */ | |
71c11c37 | 1937 | static const unsigned char filename_rev_map[] = { |
51ca58dc MH |
1938 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 7 */ |
1939 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 15 */ | |
1940 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 23 */ | |
1941 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 31 */ | |
1942 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 39 */ | |
1943 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, /* 47 */ | |
1944 | 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, /* 55 */ | |
1945 | 0x0A, 0x0B, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 63 */ | |
1946 | 0x00, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, /* 71 */ | |
1947 | 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, /* 79 */ | |
1948 | 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, /* 87 */ | |
1949 | 0x23, 0x24, 0x25, 0x00, 0x00, 0x00, 0x00, 0x00, /* 95 */ | |
1950 | 0x00, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, /* 103 */ | |
1951 | 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, /* 111 */ | |
1952 | 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, /* 119 */ | |
1953 | 0x3D, 0x3E, 0x3F | |
1954 | }; | |
1955 | ||
1956 | /** | |
1957 | * ecryptfs_encode_for_filename | |
1958 | * @dst: Destination location for encoded filename | |
1959 | * @dst_size: Size of the encoded filename in bytes | |
1960 | * @src: Source location for the filename to encode | |
1961 | * @src_size: Size of the source in bytes | |
1962 | */ | |
1963 | void ecryptfs_encode_for_filename(unsigned char *dst, size_t *dst_size, | |
1964 | unsigned char *src, size_t src_size) | |
1965 | { | |
1966 | size_t num_blocks; | |
1967 | size_t block_num = 0; | |
1968 | size_t dst_offset = 0; | |
1969 | unsigned char last_block[3]; | |
1970 | ||
1971 | if (src_size == 0) { | |
1972 | (*dst_size) = 0; | |
1973 | goto out; | |
1974 | } | |
1975 | num_blocks = (src_size / 3); | |
1976 | if ((src_size % 3) == 0) { | |
1977 | memcpy(last_block, (&src[src_size - 3]), 3); | |
1978 | } else { | |
1979 | num_blocks++; | |
1980 | last_block[2] = 0x00; | |
1981 | switch (src_size % 3) { | |
1982 | case 1: | |
1983 | last_block[0] = src[src_size - 1]; | |
1984 | last_block[1] = 0x00; | |
1985 | break; | |
1986 | case 2: | |
1987 | last_block[0] = src[src_size - 2]; | |
1988 | last_block[1] = src[src_size - 1]; | |
1989 | } | |
1990 | } | |
1991 | (*dst_size) = (num_blocks * 4); | |
1992 | if (!dst) | |
1993 | goto out; | |
1994 | while (block_num < num_blocks) { | |
1995 | unsigned char *src_block; | |
1996 | unsigned char dst_block[4]; | |
1997 | ||
1998 | if (block_num == (num_blocks - 1)) | |
1999 | src_block = last_block; | |
2000 | else | |
2001 | src_block = &src[block_num * 3]; | |
2002 | dst_block[0] = ((src_block[0] >> 2) & 0x3F); | |
2003 | dst_block[1] = (((src_block[0] << 4) & 0x30) | |
2004 | | ((src_block[1] >> 4) & 0x0F)); | |
2005 | dst_block[2] = (((src_block[1] << 2) & 0x3C) | |
2006 | | ((src_block[2] >> 6) & 0x03)); | |
2007 | dst_block[3] = (src_block[2] & 0x3F); | |
2008 | dst[dst_offset++] = portable_filename_chars[dst_block[0]]; | |
2009 | dst[dst_offset++] = portable_filename_chars[dst_block[1]]; | |
2010 | dst[dst_offset++] = portable_filename_chars[dst_block[2]]; | |
2011 | dst[dst_offset++] = portable_filename_chars[dst_block[3]]; | |
2012 | block_num++; | |
2013 | } | |
2014 | out: | |
2015 | return; | |
2016 | } | |
2017 | ||
71c11c37 MH |
2018 | /** |
2019 | * ecryptfs_decode_from_filename | |
2020 | * @dst: If NULL, this function only sets @dst_size and returns. If | |
2021 | * non-NULL, this function decodes the encoded octets in @src | |
2022 | * into the memory that @dst points to. | |
2023 | * @dst_size: Set to the size of the decoded string. | |
2024 | * @src: The encoded set of octets to decode. | |
2025 | * @src_size: The size of the encoded set of octets to decode. | |
2026 | */ | |
2027 | static void | |
2028 | ecryptfs_decode_from_filename(unsigned char *dst, size_t *dst_size, | |
2029 | const unsigned char *src, size_t src_size) | |
51ca58dc MH |
2030 | { |
2031 | u8 current_bit_offset = 0; | |
2032 | size_t src_byte_offset = 0; | |
2033 | size_t dst_byte_offset = 0; | |
51ca58dc MH |
2034 | |
2035 | if (dst == NULL) { | |
71c11c37 MH |
2036 | /* Not exact; conservatively long. Every block of 4 |
2037 | * encoded characters decodes into a block of 3 | |
2038 | * decoded characters. This segment of code provides | |
2039 | * the caller with the maximum amount of allocated | |
2040 | * space that @dst will need to point to in a | |
2041 | * subsequent call. */ | |
51ca58dc MH |
2042 | (*dst_size) = (((src_size + 1) * 3) / 4); |
2043 | goto out; | |
2044 | } | |
2045 | while (src_byte_offset < src_size) { | |
2046 | unsigned char src_byte = | |
2047 | filename_rev_map[(int)src[src_byte_offset]]; | |
2048 | ||
2049 | switch (current_bit_offset) { | |
2050 | case 0: | |
2051 | dst[dst_byte_offset] = (src_byte << 2); | |
2052 | current_bit_offset = 6; | |
2053 | break; | |
2054 | case 6: | |
2055 | dst[dst_byte_offset++] |= (src_byte >> 4); | |
2056 | dst[dst_byte_offset] = ((src_byte & 0xF) | |
2057 | << 4); | |
2058 | current_bit_offset = 4; | |
2059 | break; | |
2060 | case 4: | |
2061 | dst[dst_byte_offset++] |= (src_byte >> 2); | |
2062 | dst[dst_byte_offset] = (src_byte << 6); | |
2063 | current_bit_offset = 2; | |
2064 | break; | |
2065 | case 2: | |
2066 | dst[dst_byte_offset++] |= (src_byte); | |
2067 | dst[dst_byte_offset] = 0; | |
2068 | current_bit_offset = 0; | |
2069 | break; | |
2070 | } | |
2071 | src_byte_offset++; | |
2072 | } | |
2073 | (*dst_size) = dst_byte_offset; | |
2074 | out: | |
71c11c37 | 2075 | return; |
51ca58dc MH |
2076 | } |
2077 | ||
2078 | /** | |
2079 | * ecryptfs_encrypt_and_encode_filename - converts a plaintext file name to cipher text | |
2080 | * @crypt_stat: The crypt_stat struct associated with the file anem to encode | |
2081 | * @name: The plaintext name | |
2082 | * @length: The length of the plaintext | |
2083 | * @encoded_name: The encypted name | |
2084 | * | |
2085 | * Encrypts and encodes a filename into something that constitutes a | |
2086 | * valid filename for a filesystem, with printable characters. | |
2087 | * | |
2088 | * We assume that we have a properly initialized crypto context, | |
2089 | * pointed to by crypt_stat->tfm. | |
2090 | * | |
2091 | * Returns zero on success; non-zero on otherwise | |
2092 | */ | |
2093 | int ecryptfs_encrypt_and_encode_filename( | |
2094 | char **encoded_name, | |
2095 | size_t *encoded_name_size, | |
2096 | struct ecryptfs_crypt_stat *crypt_stat, | |
2097 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat, | |
2098 | const char *name, size_t name_size) | |
2099 | { | |
2100 | size_t encoded_name_no_prefix_size; | |
2101 | int rc = 0; | |
2102 | ||
2103 | (*encoded_name) = NULL; | |
2104 | (*encoded_name_size) = 0; | |
2105 | if ((crypt_stat && (crypt_stat->flags & ECRYPTFS_ENCRYPT_FILENAMES)) | |
2106 | || (mount_crypt_stat && (mount_crypt_stat->flags | |
2107 | & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES))) { | |
2108 | struct ecryptfs_filename *filename; | |
2109 | ||
2110 | filename = kzalloc(sizeof(*filename), GFP_KERNEL); | |
2111 | if (!filename) { | |
2112 | printk(KERN_ERR "%s: Out of memory whilst attempting " | |
a8f12864 | 2113 | "to kzalloc [%zd] bytes\n", __func__, |
51ca58dc MH |
2114 | sizeof(*filename)); |
2115 | rc = -ENOMEM; | |
2116 | goto out; | |
2117 | } | |
2118 | filename->filename = (char *)name; | |
2119 | filename->filename_size = name_size; | |
2120 | rc = ecryptfs_encrypt_filename(filename, crypt_stat, | |
2121 | mount_crypt_stat); | |
2122 | if (rc) { | |
2123 | printk(KERN_ERR "%s: Error attempting to encrypt " | |
2124 | "filename; rc = [%d]\n", __func__, rc); | |
2125 | kfree(filename); | |
2126 | goto out; | |
2127 | } | |
2128 | ecryptfs_encode_for_filename( | |
2129 | NULL, &encoded_name_no_prefix_size, | |
2130 | filename->encrypted_filename, | |
2131 | filename->encrypted_filename_size); | |
2132 | if ((crypt_stat && (crypt_stat->flags | |
2133 | & ECRYPTFS_ENCFN_USE_MOUNT_FNEK)) | |
2134 | || (mount_crypt_stat | |
2135 | && (mount_crypt_stat->flags | |
2136 | & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK))) | |
2137 | (*encoded_name_size) = | |
2138 | (ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE | |
2139 | + encoded_name_no_prefix_size); | |
2140 | else | |
2141 | (*encoded_name_size) = | |
2142 | (ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX_SIZE | |
2143 | + encoded_name_no_prefix_size); | |
2144 | (*encoded_name) = kmalloc((*encoded_name_size) + 1, GFP_KERNEL); | |
2145 | if (!(*encoded_name)) { | |
2146 | printk(KERN_ERR "%s: Out of memory whilst attempting " | |
a8f12864 | 2147 | "to kzalloc [%zd] bytes\n", __func__, |
51ca58dc MH |
2148 | (*encoded_name_size)); |
2149 | rc = -ENOMEM; | |
2150 | kfree(filename->encrypted_filename); | |
2151 | kfree(filename); | |
2152 | goto out; | |
2153 | } | |
2154 | if ((crypt_stat && (crypt_stat->flags | |
2155 | & ECRYPTFS_ENCFN_USE_MOUNT_FNEK)) | |
2156 | || (mount_crypt_stat | |
2157 | && (mount_crypt_stat->flags | |
2158 | & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK))) { | |
2159 | memcpy((*encoded_name), | |
2160 | ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX, | |
2161 | ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE); | |
2162 | ecryptfs_encode_for_filename( | |
2163 | ((*encoded_name) | |
2164 | + ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE), | |
2165 | &encoded_name_no_prefix_size, | |
2166 | filename->encrypted_filename, | |
2167 | filename->encrypted_filename_size); | |
2168 | (*encoded_name_size) = | |
2169 | (ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE | |
2170 | + encoded_name_no_prefix_size); | |
2171 | (*encoded_name)[(*encoded_name_size)] = '\0'; | |
2172 | (*encoded_name_size)++; | |
2173 | } else { | |
df6ad33b | 2174 | rc = -EOPNOTSUPP; |
51ca58dc MH |
2175 | } |
2176 | if (rc) { | |
2177 | printk(KERN_ERR "%s: Error attempting to encode " | |
2178 | "encrypted filename; rc = [%d]\n", __func__, | |
2179 | rc); | |
2180 | kfree((*encoded_name)); | |
2181 | (*encoded_name) = NULL; | |
2182 | (*encoded_name_size) = 0; | |
2183 | } | |
2184 | kfree(filename->encrypted_filename); | |
2185 | kfree(filename); | |
2186 | } else { | |
2187 | rc = ecryptfs_copy_filename(encoded_name, | |
2188 | encoded_name_size, | |
2189 | name, name_size); | |
2190 | } | |
2191 | out: | |
2192 | return rc; | |
2193 | } | |
2194 | ||
2195 | /** | |
2196 | * ecryptfs_decode_and_decrypt_filename - converts the encoded cipher text name to decoded plaintext | |
2197 | * @plaintext_name: The plaintext name | |
2198 | * @plaintext_name_size: The plaintext name size | |
2199 | * @ecryptfs_dir_dentry: eCryptfs directory dentry | |
2200 | * @name: The filename in cipher text | |
2201 | * @name_size: The cipher text name size | |
2202 | * | |
2203 | * Decrypts and decodes the filename. | |
2204 | * | |
2205 | * Returns zero on error; non-zero otherwise | |
2206 | */ | |
2207 | int ecryptfs_decode_and_decrypt_filename(char **plaintext_name, | |
2208 | size_t *plaintext_name_size, | |
2209 | struct dentry *ecryptfs_dir_dentry, | |
2210 | const char *name, size_t name_size) | |
2211 | { | |
2aac0cf8 TH |
2212 | struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
2213 | &ecryptfs_superblock_to_private( | |
2214 | ecryptfs_dir_dentry->d_sb)->mount_crypt_stat; | |
51ca58dc MH |
2215 | char *decoded_name; |
2216 | size_t decoded_name_size; | |
2217 | size_t packet_size; | |
2218 | int rc = 0; | |
2219 | ||
2aac0cf8 TH |
2220 | if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) |
2221 | && !(mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) | |
2222 | && (name_size > ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE) | |
51ca58dc MH |
2223 | && (strncmp(name, ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX, |
2224 | ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE) == 0)) { | |
51ca58dc MH |
2225 | const char *orig_name = name; |
2226 | size_t orig_name_size = name_size; | |
2227 | ||
2228 | name += ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE; | |
2229 | name_size -= ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE; | |
71c11c37 MH |
2230 | ecryptfs_decode_from_filename(NULL, &decoded_name_size, |
2231 | name, name_size); | |
51ca58dc MH |
2232 | decoded_name = kmalloc(decoded_name_size, GFP_KERNEL); |
2233 | if (!decoded_name) { | |
2234 | printk(KERN_ERR "%s: Out of memory whilst attempting " | |
df261c52 | 2235 | "to kmalloc [%zd] bytes\n", __func__, |
51ca58dc MH |
2236 | decoded_name_size); |
2237 | rc = -ENOMEM; | |
2238 | goto out; | |
2239 | } | |
71c11c37 MH |
2240 | ecryptfs_decode_from_filename(decoded_name, &decoded_name_size, |
2241 | name, name_size); | |
51ca58dc MH |
2242 | rc = ecryptfs_parse_tag_70_packet(plaintext_name, |
2243 | plaintext_name_size, | |
2244 | &packet_size, | |
2245 | mount_crypt_stat, | |
2246 | decoded_name, | |
2247 | decoded_name_size); | |
2248 | if (rc) { | |
2249 | printk(KERN_INFO "%s: Could not parse tag 70 packet " | |
2250 | "from filename; copying through filename " | |
2251 | "as-is\n", __func__); | |
2252 | rc = ecryptfs_copy_filename(plaintext_name, | |
2253 | plaintext_name_size, | |
2254 | orig_name, orig_name_size); | |
2255 | goto out_free; | |
2256 | } | |
2257 | } else { | |
2258 | rc = ecryptfs_copy_filename(plaintext_name, | |
2259 | plaintext_name_size, | |
2260 | name, name_size); | |
2261 | goto out; | |
2262 | } | |
2263 | out_free: | |
2264 | kfree(decoded_name); | |
2265 | out: | |
2266 | return rc; | |
2267 | } |