1 /* SPDX-License-Identifier: GPL-2.0 */
5 * Copyright (C) 2015, Google, Inc.
7 * This contains encryption key functions.
9 * Written by Michael Halcrow, Ildar Muslukhov, and Uday Savagaonkar, 2015.
12 #ifndef _FSCRYPT_PRIVATE_H
13 #define _FSCRYPT_PRIVATE_H
15 #include <linux/fscrypt_supp.h>
16 #include <crypto/hash.h>
18 /* Encryption parameters */
20 #define FS_AES_128_ECB_KEY_SIZE 16
21 #define FS_AES_128_CBC_KEY_SIZE 16
22 #define FS_AES_128_CTS_KEY_SIZE 16
23 #define FS_AES_256_GCM_KEY_SIZE 32
24 #define FS_AES_256_CBC_KEY_SIZE 32
25 #define FS_AES_256_CTS_KEY_SIZE 32
26 #define FS_AES_256_XTS_KEY_SIZE 64
28 #define FS_KEY_DERIVATION_NONCE_SIZE 16
31 * Encryption context for inode
34 * 1 byte: Protector format (1 = this version)
35 * 1 byte: File contents encryption mode
36 * 1 byte: File names encryption mode
38 * 8 bytes: Master Key descriptor
39 * 16 bytes: Encryption Key derivation nonce
41 struct fscrypt_context
{
43 u8 contents_encryption_mode
;
44 u8 filenames_encryption_mode
;
46 u8 master_key_descriptor
[FS_KEY_DESCRIPTOR_SIZE
];
47 u8 nonce
[FS_KEY_DERIVATION_NONCE_SIZE
];
50 #define FS_ENCRYPTION_CONTEXT_FORMAT_V1 1
53 * A pointer to this structure is stored in the file system's in-core
54 * representation of an inode.
60 struct crypto_skcipher
*ci_ctfm
;
61 struct crypto_cipher
*ci_essiv_tfm
;
62 u8 ci_master_key
[FS_KEY_DESCRIPTOR_SIZE
];
68 } fscrypt_direction_t
;
70 #define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
71 #define FS_CTX_HAS_BOUNCE_BUFFER_FL 0x00000002
74 extern int fscrypt_initialize(unsigned int cop_flags
);
75 extern struct workqueue_struct
*fscrypt_read_workqueue
;
76 extern int fscrypt_do_page_crypto(const struct inode
*inode
,
77 fscrypt_direction_t rw
, u64 lblk_num
,
78 struct page
*src_page
,
79 struct page
*dest_page
,
80 unsigned int len
, unsigned int offs
,
82 extern struct page
*fscrypt_alloc_bounce_page(struct fscrypt_ctx
*ctx
,
86 extern void __exit
fscrypt_essiv_cleanup(void);
88 #endif /* _FSCRYPT_PRIVATE_H */