xref: /linux-6.15/include/uapi/linux/fscrypt.h (revision 2336d0de)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /*
3  * fscrypt user API
4  *
5  * These ioctls can be used on filesystems that support fscrypt.  See the
6  * "User API" section of Documentation/filesystems/fscrypt.rst.
7  */
8 #ifndef _UAPI_LINUX_FSCRYPT_H
9 #define _UAPI_LINUX_FSCRYPT_H
10 
11 #include <linux/types.h>
12 
13 #define FSCRYPT_KEY_DESCRIPTOR_SIZE	8
14 
15 /* Encryption policy flags */
16 #define FSCRYPT_POLICY_FLAGS_PAD_4		0x00
17 #define FSCRYPT_POLICY_FLAGS_PAD_8		0x01
18 #define FSCRYPT_POLICY_FLAGS_PAD_16		0x02
19 #define FSCRYPT_POLICY_FLAGS_PAD_32		0x03
20 #define FSCRYPT_POLICY_FLAGS_PAD_MASK		0x03
21 #define FSCRYPT_POLICY_FLAG_DIRECT_KEY		0x04	/* use master key directly */
22 #define FSCRYPT_POLICY_FLAGS_VALID		0x07
23 
24 /* Encryption algorithms */
25 #define FSCRYPT_MODE_AES_256_XTS		1
26 #define FSCRYPT_MODE_AES_256_CTS		4
27 #define FSCRYPT_MODE_AES_128_CBC		5
28 #define FSCRYPT_MODE_AES_128_CTS		6
29 #define FSCRYPT_MODE_ADIANTUM			9
30 
31 struct fscrypt_policy {
32 	__u8 version;
33 	__u8 contents_encryption_mode;
34 	__u8 filenames_encryption_mode;
35 	__u8 flags;
36 	__u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
37 };
38 
39 #define FS_IOC_SET_ENCRYPTION_POLICY	_IOR('f', 19, struct fscrypt_policy)
40 #define FS_IOC_GET_ENCRYPTION_PWSALT	_IOW('f', 20, __u8[16])
41 #define FS_IOC_GET_ENCRYPTION_POLICY	_IOW('f', 21, struct fscrypt_policy)
42 
43 /* Parameters for passing an encryption key into the kernel keyring */
44 #define FSCRYPT_KEY_DESC_PREFIX		"fscrypt:"
45 #define FSCRYPT_KEY_DESC_PREFIX_SIZE		8
46 
47 /* Structure that userspace passes to the kernel keyring */
48 #define FSCRYPT_MAX_KEY_SIZE			64
49 
50 struct fscrypt_key {
51 	__u32 mode;
52 	__u8 raw[FSCRYPT_MAX_KEY_SIZE];
53 	__u32 size;
54 };
55 /**********************************************************************/
56 
57 /* old names; don't add anything new here! */
58 #define FS_KEY_DESCRIPTOR_SIZE		FSCRYPT_KEY_DESCRIPTOR_SIZE
59 #define FS_POLICY_FLAGS_PAD_4		FSCRYPT_POLICY_FLAGS_PAD_4
60 #define FS_POLICY_FLAGS_PAD_8		FSCRYPT_POLICY_FLAGS_PAD_8
61 #define FS_POLICY_FLAGS_PAD_16		FSCRYPT_POLICY_FLAGS_PAD_16
62 #define FS_POLICY_FLAGS_PAD_32		FSCRYPT_POLICY_FLAGS_PAD_32
63 #define FS_POLICY_FLAGS_PAD_MASK	FSCRYPT_POLICY_FLAGS_PAD_MASK
64 #define FS_POLICY_FLAG_DIRECT_KEY	FSCRYPT_POLICY_FLAG_DIRECT_KEY
65 #define FS_POLICY_FLAGS_VALID		FSCRYPT_POLICY_FLAGS_VALID
66 #define FS_ENCRYPTION_MODE_INVALID	0	/* never used */
67 #define FS_ENCRYPTION_MODE_AES_256_XTS	FSCRYPT_MODE_AES_256_XTS
68 #define FS_ENCRYPTION_MODE_AES_256_GCM	2	/* never used */
69 #define FS_ENCRYPTION_MODE_AES_256_CBC	3	/* never used */
70 #define FS_ENCRYPTION_MODE_AES_256_CTS	FSCRYPT_MODE_AES_256_CTS
71 #define FS_ENCRYPTION_MODE_AES_128_CBC	FSCRYPT_MODE_AES_128_CBC
72 #define FS_ENCRYPTION_MODE_AES_128_CTS	FSCRYPT_MODE_AES_128_CTS
73 #define FS_ENCRYPTION_MODE_SPECK128_256_XTS	7	/* removed */
74 #define FS_ENCRYPTION_MODE_SPECK128_256_CTS	8	/* removed */
75 #define FS_ENCRYPTION_MODE_ADIANTUM	FSCRYPT_MODE_ADIANTUM
76 #define FS_KEY_DESC_PREFIX		FSCRYPT_KEY_DESC_PREFIX
77 #define FS_KEY_DESC_PREFIX_SIZE		FSCRYPT_KEY_DESC_PREFIX_SIZE
78 #define FS_MAX_KEY_SIZE			FSCRYPT_MAX_KEY_SIZE
79 
80 #endif /* _UAPI_LINUX_FSCRYPT_H */
81