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
73 struct fscrypt_completion_result {
74 struct completion completion;
78 #define DECLARE_FS_COMPLETION_RESULT(ecr) \
79 struct fscrypt_completion_result ecr = { \
80 COMPLETION_INITIALIZER_ONSTACK((ecr).completion), 0 }
84 extern int fscrypt_initialize(unsigned int cop_flags);
85 extern struct workqueue_struct *fscrypt_read_workqueue;
86 extern int fscrypt_do_page_crypto(const struct inode *inode,
87 fscrypt_direction_t rw, u64 lblk_num,
88 struct page *src_page,
89 struct page *dest_page,
90 unsigned int len, unsigned int offs,
92 extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx,
96 extern void __exit fscrypt_essiv_cleanup(void);
98 #endif /* _FSCRYPT_PRIVATE_H */