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 #define __FS_HAS_ENCRYPTION 1
16 #include <linux/fscrypt.h>
17 #include <crypto/hash.h>
19 /* Encryption parameters */
21 #define FS_AES_128_ECB_KEY_SIZE 16
22 #define FS_AES_128_CBC_KEY_SIZE 16
23 #define FS_AES_128_CTS_KEY_SIZE 16
24 #define FS_AES_256_GCM_KEY_SIZE 32
25 #define FS_AES_256_CBC_KEY_SIZE 32
26 #define FS_AES_256_CTS_KEY_SIZE 32
27 #define FS_AES_256_XTS_KEY_SIZE 64
29 #define FS_KEY_DERIVATION_NONCE_SIZE 16
32 * Encryption context for inode
35 * 1 byte: Protector format (1 = this version)
36 * 1 byte: File contents encryption mode
37 * 1 byte: File names encryption mode
39 * 8 bytes: Master Key descriptor
40 * 16 bytes: Encryption Key derivation nonce
42 struct fscrypt_context {
44 u8 contents_encryption_mode;
45 u8 filenames_encryption_mode;
47 u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE];
48 u8 nonce[FS_KEY_DERIVATION_NONCE_SIZE];
51 #define FS_ENCRYPTION_CONTEXT_FORMAT_V1 1
54 * A pointer to this structure is stored in the file system's in-core
55 * representation of an inode.
61 struct crypto_skcipher *ci_ctfm;
62 struct crypto_cipher *ci_essiv_tfm;
63 u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE];
69 } fscrypt_direction_t;
71 #define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
72 #define FS_CTX_HAS_BOUNCE_BUFFER_FL 0x00000002
75 extern int fscrypt_initialize(unsigned int cop_flags);
76 extern struct workqueue_struct *fscrypt_read_workqueue;
77 extern int fscrypt_do_page_crypto(const struct inode *inode,
78 fscrypt_direction_t rw, u64 lblk_num,
79 struct page *src_page,
80 struct page *dest_page,
81 unsigned int len, unsigned int offs,
83 extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx,
87 extern void __exit fscrypt_essiv_cleanup(void);
89 #endif /* _FSCRYPT_PRIVATE_H */