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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
3325bea5 TT |
2 | /* |
3 | * fscrypt_private.h | |
4 | * | |
5 | * Copyright (C) 2015, Google, Inc. | |
6 | * | |
3ec4f2a6 EB |
7 | * Originally written by Michael Halcrow, Ildar Muslukhov, and Uday Savagaonkar. |
8 | * Heavily modified since then. | |
3325bea5 TT |
9 | */ |
10 | ||
11 | #ifndef _FSCRYPT_PRIVATE_H | |
12 | #define _FSCRYPT_PRIVATE_H | |
13 | ||
734f0d24 | 14 | #include <linux/fscrypt.h> |
aa408f83 | 15 | #include <linux/siphash.h> |
b7e7cf7a | 16 | #include <crypto/hash.h> |
5fee3609 | 17 | #include <linux/blk-crypto.h> |
3325bea5 | 18 | |
22d94f49 EB |
19 | #define CONST_STRLEN(str) (sizeof(str) - 1) |
20 | ||
11b8818e | 21 | #define FS_KEY_DERIVATION_NONCE_SIZE 16 |
cc4e0df0 | 22 | |
22d94f49 EB |
23 | #define FSCRYPT_MIN_KEY_SIZE 16 |
24 | ||
5dae460c EB |
25 | #define FSCRYPT_CONTEXT_V1 1 |
26 | #define FSCRYPT_CONTEXT_V2 2 | |
27 | ||
28 | struct fscrypt_context_v1 { | |
29 | u8 version; /* FSCRYPT_CONTEXT_V1 */ | |
cc4e0df0 TT |
30 | u8 contents_encryption_mode; |
31 | u8 filenames_encryption_mode; | |
32 | u8 flags; | |
3b6df59b | 33 | u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE]; |
cc4e0df0 | 34 | u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE]; |
5dae460c | 35 | }; |
cc4e0df0 | 36 | |
5dae460c EB |
37 | struct fscrypt_context_v2 { |
38 | u8 version; /* FSCRYPT_CONTEXT_V2 */ | |
39 | u8 contents_encryption_mode; | |
40 | u8 filenames_encryption_mode; | |
41 | u8 flags; | |
42 | u8 __reserved[4]; | |
43 | u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE]; | |
44 | u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE]; | |
45 | }; | |
46 | ||
d2fe9754 | 47 | /* |
5dae460c EB |
48 | * fscrypt_context - the encryption context of an inode |
49 | * | |
50 | * This is the on-disk equivalent of an fscrypt_policy, stored alongside each | |
51 | * encrypted file usually in a hidden extended attribute. It contains the | |
52 | * fields from the fscrypt_policy, in order to identify the encryption algorithm | |
53 | * and key with which the file is encrypted. It also contains a nonce that was | |
54 | * randomly generated by fscrypt itself; this is used as KDF input or as a tweak | |
55 | * to cause different files to be encrypted differently. | |
56 | */ | |
57 | union fscrypt_context { | |
58 | u8 version; | |
59 | struct fscrypt_context_v1 v1; | |
60 | struct fscrypt_context_v2 v2; | |
61 | }; | |
62 | ||
63 | /* | |
64 | * Return the size expected for the given fscrypt_context based on its version | |
65 | * number, or 0 if the context version is unrecognized. | |
66 | */ | |
67 | static inline int fscrypt_context_size(const union fscrypt_context *ctx) | |
68 | { | |
69 | switch (ctx->version) { | |
70 | case FSCRYPT_CONTEXT_V1: | |
71 | BUILD_BUG_ON(sizeof(ctx->v1) != 28); | |
72 | return sizeof(ctx->v1); | |
73 | case FSCRYPT_CONTEXT_V2: | |
74 | BUILD_BUG_ON(sizeof(ctx->v2) != 40); | |
75 | return sizeof(ctx->v2); | |
76 | } | |
77 | return 0; | |
78 | } | |
79 | ||
e98ad464 EB |
80 | /* Check whether an fscrypt_context has a recognized version number and size */ |
81 | static inline bool fscrypt_context_is_valid(const union fscrypt_context *ctx, | |
82 | int ctx_size) | |
83 | { | |
84 | return ctx_size >= 1 && ctx_size == fscrypt_context_size(ctx); | |
85 | } | |
86 | ||
87 | /* Retrieve the context's nonce, assuming the context was already validated */ | |
88 | static inline const u8 *fscrypt_context_nonce(const union fscrypt_context *ctx) | |
89 | { | |
90 | switch (ctx->version) { | |
91 | case FSCRYPT_CONTEXT_V1: | |
92 | return ctx->v1.nonce; | |
93 | case FSCRYPT_CONTEXT_V2: | |
94 | return ctx->v2.nonce; | |
95 | } | |
96 | WARN_ON(1); | |
97 | return NULL; | |
98 | } | |
99 | ||
5dae460c EB |
100 | #undef fscrypt_policy |
101 | union fscrypt_policy { | |
102 | u8 version; | |
103 | struct fscrypt_policy_v1 v1; | |
104 | struct fscrypt_policy_v2 v2; | |
105 | }; | |
106 | ||
107 | /* | |
108 | * Return the size expected for the given fscrypt_policy based on its version | |
109 | * number, or 0 if the policy version is unrecognized. | |
110 | */ | |
111 | static inline int fscrypt_policy_size(const union fscrypt_policy *policy) | |
112 | { | |
113 | switch (policy->version) { | |
114 | case FSCRYPT_POLICY_V1: | |
115 | return sizeof(policy->v1); | |
116 | case FSCRYPT_POLICY_V2: | |
117 | return sizeof(policy->v2); | |
118 | } | |
119 | return 0; | |
120 | } | |
121 | ||
122 | /* Return the contents encryption mode of a valid encryption policy */ | |
123 | static inline u8 | |
124 | fscrypt_policy_contents_mode(const union fscrypt_policy *policy) | |
125 | { | |
126 | switch (policy->version) { | |
127 | case FSCRYPT_POLICY_V1: | |
128 | return policy->v1.contents_encryption_mode; | |
129 | case FSCRYPT_POLICY_V2: | |
130 | return policy->v2.contents_encryption_mode; | |
131 | } | |
132 | BUG(); | |
133 | } | |
134 | ||
135 | /* Return the filenames encryption mode of a valid encryption policy */ | |
136 | static inline u8 | |
137 | fscrypt_policy_fnames_mode(const union fscrypt_policy *policy) | |
138 | { | |
139 | switch (policy->version) { | |
140 | case FSCRYPT_POLICY_V1: | |
141 | return policy->v1.filenames_encryption_mode; | |
142 | case FSCRYPT_POLICY_V2: | |
143 | return policy->v2.filenames_encryption_mode; | |
144 | } | |
145 | BUG(); | |
146 | } | |
147 | ||
148 | /* Return the flags (FSCRYPT_POLICY_FLAG*) of a valid encryption policy */ | |
149 | static inline u8 | |
150 | fscrypt_policy_flags(const union fscrypt_policy *policy) | |
151 | { | |
152 | switch (policy->version) { | |
153 | case FSCRYPT_POLICY_V1: | |
154 | return policy->v1.flags; | |
155 | case FSCRYPT_POLICY_V2: | |
156 | return policy->v2.flags; | |
157 | } | |
158 | BUG(); | |
159 | } | |
160 | ||
d2fe9754 | 161 | /* |
0eaab5b1 EB |
162 | * For encrypted symlinks, the ciphertext length is stored at the beginning |
163 | * of the string in little-endian format. | |
164 | */ | |
165 | struct fscrypt_symlink_data { | |
166 | __le16 len; | |
167 | char encrypted_path[1]; | |
168 | } __packed; | |
169 | ||
5fee3609 ST |
170 | /** |
171 | * struct fscrypt_prepared_key - a key prepared for actual encryption/decryption | |
172 | * @tfm: crypto API transform object | |
173 | * @blk_key: key for blk-crypto | |
174 | * | |
175 | * Normally only one of the fields will be non-NULL. | |
176 | */ | |
177 | struct fscrypt_prepared_key { | |
178 | struct crypto_skcipher *tfm; | |
179 | #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT | |
180 | struct fscrypt_blk_crypto_key *blk_key; | |
181 | #endif | |
182 | }; | |
183 | ||
cc4e0df0 | 184 | /* |
8094c3ce EB |
185 | * fscrypt_info - the "encryption key" for an inode |
186 | * | |
187 | * When an encrypted file's key is made available, an instance of this struct is | |
188 | * allocated and stored in ->i_crypt_info. Once created, it remains until the | |
189 | * inode is evicted. | |
cc4e0df0 TT |
190 | */ |
191 | struct fscrypt_info { | |
8094c3ce | 192 | |
5fee3609 ST |
193 | /* The key in a form prepared for actual encryption/decryption */ |
194 | struct fscrypt_prepared_key ci_enc_key; | |
8094c3ce | 195 | |
5fee3609 | 196 | /* True if ci_enc_key should be freed when this fscrypt_info is freed */ |
b103fb76 EB |
197 | bool ci_owns_key; |
198 | ||
5fee3609 ST |
199 | #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT |
200 | /* | |
201 | * True if this inode will use inline encryption (blk-crypto) instead of | |
202 | * the traditional filesystem-layer encryption. | |
203 | */ | |
204 | bool ci_inlinecrypt; | |
205 | #endif | |
206 | ||
8094c3ce | 207 | /* |
5dae460c EB |
208 | * Encryption mode used for this inode. It corresponds to either the |
209 | * contents or filenames encryption mode, depending on the inode type. | |
8094c3ce EB |
210 | */ |
211 | struct fscrypt_mode *ci_mode; | |
212 | ||
59dc6a8e EB |
213 | /* Back-pointer to the inode */ |
214 | struct inode *ci_inode; | |
215 | ||
b1c0ec35 EB |
216 | /* |
217 | * The master key with which this inode was unlocked (decrypted). This | |
218 | * will be NULL if the master key was found in a process-subscribed | |
219 | * keyring rather than in the filesystem-level keyring. | |
220 | */ | |
221 | struct key *ci_master_key; | |
222 | ||
223 | /* | |
224 | * Link in list of inodes that were unlocked with the master key. | |
225 | * Only used when ->ci_master_key is set. | |
226 | */ | |
227 | struct list_head ci_master_key_link; | |
228 | ||
8094c3ce | 229 | /* |
a828daab | 230 | * If non-NULL, then encryption is done using the master key directly |
5fee3609 | 231 | * and ci_enc_key will equal ci_direct_key->dk_key. |
8094c3ce | 232 | */ |
a828daab | 233 | struct fscrypt_direct_key *ci_direct_key; |
8094c3ce | 234 | |
aa408f83 DR |
235 | /* |
236 | * This inode's hash key for filenames. This is a 128-bit SipHash-2-4 | |
237 | * key. This is only set for directories that use a keyed dirhash over | |
238 | * the plaintext filenames -- currently just casefolded directories. | |
239 | */ | |
240 | siphash_key_t ci_dirhash_key; | |
241 | bool ci_dirhash_key_initialized; | |
242 | ||
5dae460c EB |
243 | /* The encryption policy used by this inode */ |
244 | union fscrypt_policy ci_policy; | |
245 | ||
246 | /* This inode's nonce, copied from the fscrypt_context */ | |
8094c3ce | 247 | u8 ci_nonce[FS_KEY_DERIVATION_NONCE_SIZE]; |
e3b1078b EB |
248 | |
249 | /* Hashed inode number. Only set for IV_INO_LBLK_32 */ | |
250 | u32 ci_hashed_ino; | |
cc4e0df0 TT |
251 | }; |
252 | ||
58ae7468 RW |
253 | typedef enum { |
254 | FS_DECRYPT = 0, | |
255 | FS_ENCRYPT, | |
256 | } fscrypt_direction_t; | |
257 | ||
b98701df | 258 | /* crypto.c */ |
e4de782a | 259 | extern struct kmem_cache *fscrypt_info_cachep; |
60700902 EB |
260 | int fscrypt_initialize(unsigned int cop_flags); |
261 | int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw, | |
262 | u64 lblk_num, struct page *src_page, | |
263 | struct page *dest_page, unsigned int len, | |
264 | unsigned int offs, gfp_t gfp_flags); | |
265 | struct page *fscrypt_alloc_bounce_page(gfp_t gfp_flags); | |
266 | ||
267 | void __printf(3, 4) __cold | |
886da8b3 | 268 | fscrypt_msg(const struct inode *inode, const char *level, const char *fmt, ...); |
544d08fd | 269 | |
886da8b3 EB |
270 | #define fscrypt_warn(inode, fmt, ...) \ |
271 | fscrypt_msg((inode), KERN_WARNING, fmt, ##__VA_ARGS__) | |
272 | #define fscrypt_err(inode, fmt, ...) \ | |
273 | fscrypt_msg((inode), KERN_ERR, fmt, ##__VA_ARGS__) | |
544d08fd | 274 | |
8094c3ce EB |
275 | #define FSCRYPT_MAX_IV_SIZE 32 |
276 | ||
277 | union fscrypt_iv { | |
278 | struct { | |
279 | /* logical block number within the file */ | |
280 | __le64 lblk_num; | |
281 | ||
282 | /* per-file nonce; only set in DIRECT_KEY mode */ | |
283 | u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE]; | |
284 | }; | |
285 | u8 raw[FSCRYPT_MAX_IV_SIZE]; | |
5fee3609 | 286 | __le64 dun[FSCRYPT_MAX_IV_SIZE / sizeof(__le64)]; |
8094c3ce EB |
287 | }; |
288 | ||
289 | void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num, | |
290 | const struct fscrypt_info *ci); | |
291 | ||
76e81d6d | 292 | /* fname.c */ |
60700902 EB |
293 | int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname, |
294 | u8 *out, unsigned int olen); | |
295 | bool fscrypt_fname_encrypted_size(const struct inode *inode, u32 orig_len, | |
296 | u32 max_len, u32 *encrypted_len_ret); | |
2ebdef6d | 297 | extern const struct dentry_operations fscrypt_d_ops; |
76e81d6d | 298 | |
c1144c9b EB |
299 | /* hkdf.c */ |
300 | ||
301 | struct fscrypt_hkdf { | |
302 | struct crypto_shash *hmac_tfm; | |
303 | }; | |
304 | ||
60700902 EB |
305 | int fscrypt_init_hkdf(struct fscrypt_hkdf *hkdf, const u8 *master_key, |
306 | unsigned int master_key_size); | |
c1144c9b | 307 | |
5dae460c EB |
308 | /* |
309 | * The list of contexts in which fscrypt uses HKDF. These values are used as | |
310 | * the first byte of the HKDF application-specific info string to guarantee that | |
311 | * info strings are never repeated between contexts. This ensures that all HKDF | |
312 | * outputs are unique and cryptographically isolated, i.e. knowledge of one | |
313 | * output doesn't reveal another. | |
314 | */ | |
e455de31 EB |
315 | #define HKDF_CONTEXT_KEY_IDENTIFIER 1 /* info=<empty> */ |
316 | #define HKDF_CONTEXT_PER_FILE_ENC_KEY 2 /* info=file_nonce */ | |
317 | #define HKDF_CONTEXT_DIRECT_KEY 3 /* info=mode_num */ | |
318 | #define HKDF_CONTEXT_IV_INO_LBLK_64_KEY 4 /* info=mode_num||fs_uuid */ | |
319 | #define HKDF_CONTEXT_DIRHASH_KEY 5 /* info=file_nonce */ | |
320 | #define HKDF_CONTEXT_IV_INO_LBLK_32_KEY 6 /* info=mode_num||fs_uuid */ | |
321 | #define HKDF_CONTEXT_INODE_HASH_KEY 7 /* info=<empty> */ | |
5dae460c | 322 | |
60700902 EB |
323 | int fscrypt_hkdf_expand(const struct fscrypt_hkdf *hkdf, u8 context, |
324 | const u8 *info, unsigned int infolen, | |
325 | u8 *okm, unsigned int okmlen); | |
c1144c9b | 326 | |
60700902 | 327 | void fscrypt_destroy_hkdf(struct fscrypt_hkdf *hkdf); |
c1144c9b | 328 | |
5fee3609 ST |
329 | /* inline_crypt.c */ |
330 | #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT | |
331 | int fscrypt_select_encryption_impl(struct fscrypt_info *ci); | |
332 | ||
333 | static inline bool | |
334 | fscrypt_using_inline_encryption(const struct fscrypt_info *ci) | |
335 | { | |
336 | return ci->ci_inlinecrypt; | |
337 | } | |
338 | ||
339 | int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key, | |
340 | const u8 *raw_key, | |
341 | const struct fscrypt_info *ci); | |
342 | ||
343 | void fscrypt_destroy_inline_crypt_key(struct fscrypt_prepared_key *prep_key); | |
344 | ||
345 | /* | |
346 | * Check whether the crypto transform or blk-crypto key has been allocated in | |
347 | * @prep_key, depending on which encryption implementation the file will use. | |
348 | */ | |
349 | static inline bool | |
350 | fscrypt_is_key_prepared(struct fscrypt_prepared_key *prep_key, | |
351 | const struct fscrypt_info *ci) | |
352 | { | |
353 | /* | |
354 | * The READ_ONCE() here pairs with the smp_store_release() in | |
355 | * fscrypt_prepare_key(). (This only matters for the per-mode keys, | |
356 | * which are shared by multiple inodes.) | |
357 | */ | |
358 | if (fscrypt_using_inline_encryption(ci)) | |
359 | return READ_ONCE(prep_key->blk_key) != NULL; | |
360 | return READ_ONCE(prep_key->tfm) != NULL; | |
361 | } | |
362 | ||
363 | #else /* CONFIG_FS_ENCRYPTION_INLINE_CRYPT */ | |
364 | ||
365 | static inline int fscrypt_select_encryption_impl(struct fscrypt_info *ci) | |
366 | { | |
367 | return 0; | |
368 | } | |
369 | ||
370 | static inline bool | |
371 | fscrypt_using_inline_encryption(const struct fscrypt_info *ci) | |
372 | { | |
373 | return false; | |
374 | } | |
375 | ||
376 | static inline int | |
377 | fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key, | |
378 | const u8 *raw_key, | |
379 | const struct fscrypt_info *ci) | |
380 | { | |
381 | WARN_ON(1); | |
382 | return -EOPNOTSUPP; | |
383 | } | |
384 | ||
385 | static inline void | |
386 | fscrypt_destroy_inline_crypt_key(struct fscrypt_prepared_key *prep_key) | |
387 | { | |
388 | } | |
389 | ||
390 | static inline bool | |
391 | fscrypt_is_key_prepared(struct fscrypt_prepared_key *prep_key, | |
392 | const struct fscrypt_info *ci) | |
393 | { | |
394 | return READ_ONCE(prep_key->tfm) != NULL; | |
395 | } | |
396 | #endif /* !CONFIG_FS_ENCRYPTION_INLINE_CRYPT */ | |
397 | ||
22d94f49 EB |
398 | /* keyring.c */ |
399 | ||
400 | /* | |
401 | * fscrypt_master_key_secret - secret key material of an in-use master key | |
402 | */ | |
403 | struct fscrypt_master_key_secret { | |
404 | ||
5dae460c EB |
405 | /* |
406 | * For v2 policy keys: HKDF context keyed by this master key. | |
407 | * For v1 policy keys: not set (hkdf.hmac_tfm == NULL). | |
408 | */ | |
409 | struct fscrypt_hkdf hkdf; | |
410 | ||
411 | /* Size of the raw key in bytes. Set even if ->raw isn't set. */ | |
22d94f49 EB |
412 | u32 size; |
413 | ||
5dae460c | 414 | /* For v1 policy keys: the raw key. Wiped for v2 policy keys. */ |
22d94f49 EB |
415 | u8 raw[FSCRYPT_MAX_KEY_SIZE]; |
416 | ||
417 | } __randomize_layout; | |
418 | ||
419 | /* | |
420 | * fscrypt_master_key - an in-use master key | |
421 | * | |
422 | * This represents a master encryption key which has been added to the | |
423 | * filesystem and can be used to "unlock" the encrypted files which were | |
424 | * encrypted with it. | |
425 | */ | |
426 | struct fscrypt_master_key { | |
427 | ||
b1c0ec35 EB |
428 | /* |
429 | * The secret key material. After FS_IOC_REMOVE_ENCRYPTION_KEY is | |
430 | * executed, this is wiped and no new inodes can be unlocked with this | |
431 | * key; however, there may still be inodes in ->mk_decrypted_inodes | |
432 | * which could not be evicted. As long as some inodes still remain, | |
433 | * FS_IOC_REMOVE_ENCRYPTION_KEY can be retried, or | |
434 | * FS_IOC_ADD_ENCRYPTION_KEY can add the secret again. | |
435 | * | |
23c688b5 EB |
436 | * Locking: protected by key->sem (outer) and mk_secret_sem (inner). |
437 | * The reason for two locks is that key->sem also protects modifying | |
438 | * mk_users, which ranks it above the semaphore for the keyring key | |
439 | * type, which is in turn above page faults (via keyring_read). But | |
440 | * sometimes filesystems call fscrypt_get_encryption_info() from within | |
441 | * a transaction, which ranks it below page faults. So we need a | |
442 | * separate lock which protects mk_secret but not also mk_users. | |
b1c0ec35 | 443 | */ |
22d94f49 | 444 | struct fscrypt_master_key_secret mk_secret; |
23c688b5 | 445 | struct rw_semaphore mk_secret_sem; |
22d94f49 | 446 | |
5dae460c EB |
447 | /* |
448 | * For v1 policy keys: an arbitrary key descriptor which was assigned by | |
449 | * userspace (->descriptor). | |
450 | * | |
451 | * For v2 policy keys: a cryptographic hash of this key (->identifier). | |
452 | */ | |
22d94f49 EB |
453 | struct fscrypt_key_specifier mk_spec; |
454 | ||
23c688b5 EB |
455 | /* |
456 | * Keyring which contains a key of type 'key_type_fscrypt_user' for each | |
457 | * user who has added this key. Normally each key will be added by just | |
458 | * one user, but it's possible that multiple users share a key, and in | |
459 | * that case we need to keep track of those users so that one user can't | |
460 | * remove the key before the others want it removed too. | |
461 | * | |
462 | * This is NULL for v1 policy keys; those can only be added by root. | |
463 | * | |
464 | * Locking: in addition to this keyrings own semaphore, this is | |
465 | * protected by the master key's key->sem, so we can do atomic | |
466 | * search+insert. It can also be searched without taking any locks, but | |
467 | * in that case the returned key may have already been removed. | |
468 | */ | |
469 | struct key *mk_users; | |
470 | ||
b1c0ec35 EB |
471 | /* |
472 | * Length of ->mk_decrypted_inodes, plus one if mk_secret is present. | |
473 | * Once this goes to 0, the master key is removed from ->s_master_keys. | |
474 | * The 'struct fscrypt_master_key' will continue to live as long as the | |
475 | * 'struct key' whose payload it is, but we won't let this reference | |
476 | * count rise again. | |
477 | */ | |
478 | refcount_t mk_refcount; | |
479 | ||
480 | /* | |
481 | * List of inodes that were unlocked using this key. This allows the | |
482 | * inodes to be evicted efficiently if the key is removed. | |
483 | */ | |
484 | struct list_head mk_decrypted_inodes; | |
485 | spinlock_t mk_decrypted_inodes_lock; | |
486 | ||
b103fb76 | 487 | /* |
e3b1078b EB |
488 | * Per-mode encryption keys for the various types of encryption policies |
489 | * that use them. Allocated and derived on-demand. | |
b103fb76 | 490 | */ |
5fee3609 ST |
491 | struct fscrypt_prepared_key mk_direct_keys[__FSCRYPT_MODE_MAX + 1]; |
492 | struct fscrypt_prepared_key mk_iv_ino_lblk_64_keys[__FSCRYPT_MODE_MAX + 1]; | |
493 | struct fscrypt_prepared_key mk_iv_ino_lblk_32_keys[__FSCRYPT_MODE_MAX + 1]; | |
e3b1078b EB |
494 | |
495 | /* Hash key for inode numbers. Initialized only when needed. */ | |
496 | siphash_key_t mk_ino_hash_key; | |
497 | bool mk_ino_hash_key_initialized; | |
5dae460c | 498 | |
22d94f49 EB |
499 | } __randomize_layout; |
500 | ||
b1c0ec35 EB |
501 | static inline bool |
502 | is_master_key_secret_present(const struct fscrypt_master_key_secret *secret) | |
503 | { | |
504 | /* | |
505 | * The READ_ONCE() is only necessary for fscrypt_drop_inode() and | |
506 | * fscrypt_key_describe(). These run in atomic context, so they can't | |
23c688b5 EB |
507 | * take ->mk_secret_sem and thus 'secret' can change concurrently which |
508 | * would be a data race. But they only need to know whether the secret | |
509 | * *was* present at the time of check, so READ_ONCE() suffices. | |
b1c0ec35 EB |
510 | */ |
511 | return READ_ONCE(secret->size) != 0; | |
512 | } | |
513 | ||
22d94f49 EB |
514 | static inline const char *master_key_spec_type( |
515 | const struct fscrypt_key_specifier *spec) | |
516 | { | |
517 | switch (spec->type) { | |
518 | case FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR: | |
519 | return "descriptor"; | |
5dae460c EB |
520 | case FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER: |
521 | return "identifier"; | |
22d94f49 EB |
522 | } |
523 | return "[unknown]"; | |
524 | } | |
525 | ||
526 | static inline int master_key_spec_len(const struct fscrypt_key_specifier *spec) | |
527 | { | |
528 | switch (spec->type) { | |
529 | case FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR: | |
530 | return FSCRYPT_KEY_DESCRIPTOR_SIZE; | |
5dae460c EB |
531 | case FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER: |
532 | return FSCRYPT_KEY_IDENTIFIER_SIZE; | |
22d94f49 EB |
533 | } |
534 | return 0; | |
535 | } | |
536 | ||
60700902 | 537 | struct key * |
22d94f49 EB |
538 | fscrypt_find_master_key(struct super_block *sb, |
539 | const struct fscrypt_key_specifier *mk_spec); | |
540 | ||
cdeb21da EB |
541 | int fscrypt_add_test_dummy_key(struct super_block *sb, |
542 | struct fscrypt_key_specifier *key_spec); | |
543 | ||
60700902 EB |
544 | int fscrypt_verify_key_added(struct super_block *sb, |
545 | const u8 identifier[FSCRYPT_KEY_IDENTIFIER_SIZE]); | |
5ab7189a | 546 | |
60700902 | 547 | int __init fscrypt_init_keyring(void); |
22d94f49 | 548 | |
feed8258 | 549 | /* keysetup.c */ |
8094c3ce EB |
550 | |
551 | struct fscrypt_mode { | |
552 | const char *friendly_name; | |
553 | const char *cipher_str; | |
554 | int keysize; | |
555 | int ivsize; | |
ff73c2c0 | 556 | int logged_impl_name; |
5fee3609 | 557 | enum blk_crypto_mode_num blk_crypto_mode; |
8094c3ce EB |
558 | }; |
559 | ||
85af90e5 | 560 | extern struct fscrypt_mode fscrypt_modes[]; |
3ec4f2a6 | 561 | |
5fee3609 ST |
562 | int fscrypt_prepare_key(struct fscrypt_prepared_key *prep_key, |
563 | const u8 *raw_key, const struct fscrypt_info *ci); | |
564 | ||
565 | void fscrypt_destroy_prepared_key(struct fscrypt_prepared_key *prep_key); | |
0109ce76 | 566 | |
60700902 | 567 | int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci, const u8 *raw_key); |
0109ce76 | 568 | |
60700902 EB |
569 | int fscrypt_derive_dirhash_key(struct fscrypt_info *ci, |
570 | const struct fscrypt_master_key *mk); | |
aa408f83 | 571 | |
0109ce76 EB |
572 | /* keysetup_v1.c */ |
573 | ||
60700902 | 574 | void fscrypt_put_direct_key(struct fscrypt_direct_key *dk); |
0109ce76 | 575 | |
60700902 EB |
576 | int fscrypt_setup_v1_file_key(struct fscrypt_info *ci, |
577 | const u8 *raw_master_key); | |
578 | ||
579 | int fscrypt_setup_v1_file_key_via_subscribed_keyrings(struct fscrypt_info *ci); | |
0109ce76 | 580 | |
5dae460c EB |
581 | /* policy.c */ |
582 | ||
60700902 EB |
583 | bool fscrypt_policies_equal(const union fscrypt_policy *policy1, |
584 | const union fscrypt_policy *policy2); | |
585 | bool fscrypt_supported_policy(const union fscrypt_policy *policy_u, | |
586 | const struct inode *inode); | |
587 | int fscrypt_policy_from_context(union fscrypt_policy *policy_u, | |
588 | const union fscrypt_context *ctx_u, | |
589 | int ctx_size); | |
0109ce76 | 590 | |
3325bea5 | 591 | #endif /* _FSCRYPT_PRIVATE_H */ |