blob: 58682d2830e990c2e3fe291abe86764ad9c4dce1 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
/*
* linux/fs/f2fs/f2fs_crypto.h
*
* Copied from linux/fs/ext4/ext4_crypto.h
*
* Copyright (C) 2015, Google, Inc.
*
* This contains encryption header content for f2fs
*
* Written by Michael Halcrow, 2015.
* Modified by Jaegeuk Kim, 2015.
*/
#ifndef _F2FS_CRYPTO_H
#define _F2FS_CRYPTO_H
#include <linux/fs.h>
#define F2FS_KEY_DESCRIPTOR_SIZE 8
/* Policy provided via an ioctl on the topmost directory */
struct f2fs_encryption_policy {
char version;
char contents_encryption_mode;
char filenames_encryption_mode;
char flags;
char master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE];
} __attribute__((__packed__));
#define F2FS_ENCRYPTION_CONTEXT_FORMAT_V1 1
#define F2FS_KEY_DERIVATION_NONCE_SIZE 16
#define F2FS_POLICY_FLAGS_PAD_4 0x00
#define F2FS_POLICY_FLAGS_PAD_8 0x01
#define F2FS_POLICY_FLAGS_PAD_16 0x02
#define F2FS_POLICY_FLAGS_PAD_32 0x03
#define F2FS_POLICY_FLAGS_PAD_MASK 0x03
#define F2FS_POLICY_FLAGS_VALID 0x03
/**
* Encryption context for inode
*
* Protector format:
* 1 byte: Protector format (1 = this version)
* 1 byte: File contents encryption mode
* 1 byte: File names encryption mode
* 1 byte: Flags
* 8 bytes: Master Key descriptor
* 16 bytes: Encryption Key derivation nonce
*/
struct f2fs_encryption_context {
char format;
char contents_encryption_mode;
char filenames_encryption_mode;
char flags;
char master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE];
char nonce[F2FS_KEY_DERIVATION_NONCE_SIZE];
} __attribute__((__packed__));
/* Encryption parameters */
#define F2FS_XTS_TWEAK_SIZE 16
#define F2FS_AES_128_ECB_KEY_SIZE 16
#define F2FS_AES_256_GCM_KEY_SIZE 32
#define F2FS_AES_256_CBC_KEY_SIZE 32
#define F2FS_AES_256_CTS_KEY_SIZE 32
#define F2FS_AES_256_XTS_KEY_SIZE 64
#define F2FS_MAX_KEY_SIZE 64
#define F2FS_KEY_DESC_PREFIX "f2fs:"
#define F2FS_KEY_DESC_PREFIX_SIZE 5
struct f2fs_encryption_key {
__u32 mode;
char raw[F2FS_MAX_KEY_SIZE];
__u32 size;
} __attribute__((__packed__));
struct f2fs_crypt_info {
unsigned char ci_size;
char ci_data_mode;
char ci_filename_mode;
char ci_flags;
struct crypto_ablkcipher *ci_ctfm;
struct key *ci_keyring_key;
char ci_raw[F2FS_MAX_KEY_SIZE];
char ci_master_key[F2FS_KEY_DESCRIPTOR_SIZE];
};
#define F2FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
#define F2FS_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL 0x00000002
struct f2fs_crypto_ctx {
struct crypto_tfm *tfm; /* Crypto API context */
struct page *bounce_page; /* Ciphertext page on write path */
struct page *control_page; /* Original page on write path */
struct bio *bio; /* The bio for this context */
struct work_struct work; /* Work queue for read complete path */
struct list_head free_list; /* Free list */
int flags; /* Flags */
int mode; /* Encryption mode for tfm */
};
struct f2fs_completion_result {
struct completion completion;
int res;
};
#define DECLARE_F2FS_COMPLETION_RESULT(ecr) \
struct f2fs_completion_result ecr = { \
COMPLETION_INITIALIZER((ecr).completion), 0 }
static inline int f2fs_encryption_key_size(int mode)
{
switch (mode) {
case F2FS_ENCRYPTION_MODE_AES_256_XTS:
return F2FS_AES_256_XTS_KEY_SIZE;
case F2FS_ENCRYPTION_MODE_AES_256_GCM:
return F2FS_AES_256_GCM_KEY_SIZE;
case F2FS_ENCRYPTION_MODE_AES_256_CBC:
return F2FS_AES_256_CBC_KEY_SIZE;
case F2FS_ENCRYPTION_MODE_AES_256_CTS:
return F2FS_AES_256_CTS_KEY_SIZE;
default:
BUG();
}
return 0;
}
#define F2FS_FNAME_NUM_SCATTER_ENTRIES 4
#define F2FS_CRYPTO_BLOCK_SIZE 16
#define F2FS_FNAME_CRYPTO_DIGEST_SIZE 32
/**
* For encrypted symlinks, the ciphertext length is stored at the beginning
* of the string in little-endian format.
*/
struct f2fs_encrypted_symlink_data {
__le16 len;
char encrypted_path[1];
} __attribute__((__packed__));
/**
* This function is used to calculate the disk space required to
* store a filename of length l in encrypted symlink format.
*/
static inline u32 encrypted_symlink_data_len(u32 l)
{
return (l + sizeof(struct f2fs_encrypted_symlink_data) - 1);
}
#endif /* _F2FS_CRYPTO_H */
|
