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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/* Encryption policy flags */
14#define FSCRYPT_POLICY_FLAGS_PAD_4 0x00
15#define FSCRYPT_POLICY_FLAGS_PAD_8 0x01
16#define FSCRYPT_POLICY_FLAGS_PAD_16 0x02
17#define FSCRYPT_POLICY_FLAGS_PAD_32 0x03
18#define FSCRYPT_POLICY_FLAGS_PAD_MASK 0x03
19#define FSCRYPT_POLICY_FLAG_DIRECT_KEY 0x04
20#define FSCRYPT_POLICY_FLAGS_VALID 0x07
21
22/* Encryption algorithms */
23#define FSCRYPT_MODE_AES_256_XTS 1
24#define FSCRYPT_MODE_AES_256_CTS 4
25#define FSCRYPT_MODE_AES_128_CBC 5
26#define FSCRYPT_MODE_AES_128_CTS 6
27#define FSCRYPT_MODE_ADIANTUM 9
28#define __FSCRYPT_MODE_MAX 9
29
30/*
31 * Legacy policy version; ad-hoc KDF and no key verification.
32 * For new encrypted directories, use fscrypt_policy_v2 instead.
33 *
34 * Careful: the .version field for this is actually 0, not 1.
35 */
36#define FSCRYPT_POLICY_V1 0
37#define FSCRYPT_KEY_DESCRIPTOR_SIZE 8
38struct fscrypt_policy_v1 {
39 __u8 version;
40 __u8 contents_encryption_mode;
41 __u8 filenames_encryption_mode;
42 __u8 flags;
43 __u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
44};
45#define fscrypt_policy fscrypt_policy_v1
46
47/*
48 * Process-subscribed "logon" key description prefix and payload format.
49 * Deprecated; prefer FS_IOC_ADD_ENCRYPTION_KEY instead.
50 */
51#define FSCRYPT_KEY_DESC_PREFIX "fscrypt:"
52#define FSCRYPT_KEY_DESC_PREFIX_SIZE 8
53#define FSCRYPT_MAX_KEY_SIZE 64
54struct fscrypt_key {
55 __u32 mode;
56 __u8 raw[FSCRYPT_MAX_KEY_SIZE];
57 __u32 size;
58};
59
60/*
61 * New policy version with HKDF and key verification (recommended).
62 */
63#define FSCRYPT_POLICY_V2 2
64#define FSCRYPT_KEY_IDENTIFIER_SIZE 16
65struct fscrypt_policy_v2 {
66 __u8 version;
67 __u8 contents_encryption_mode;
68 __u8 filenames_encryption_mode;
69 __u8 flags;
70 __u8 __reserved[4];
71 __u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
72};
73
74/* Struct passed to FS_IOC_GET_ENCRYPTION_POLICY_EX */
75struct fscrypt_get_policy_ex_arg {
76 __u64 policy_size; /* input/output */
77 union {
78 __u8 version;
79 struct fscrypt_policy_v1 v1;
80 struct fscrypt_policy_v2 v2;
81 } policy; /* output */
82};
83
84/*
85 * v1 policy keys are specified by an arbitrary 8-byte key "descriptor",
86 * matching fscrypt_policy_v1::master_key_descriptor.
87 */
88#define FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR 1
89
90/*
91 * v2 policy keys are specified by a 16-byte key "identifier" which the kernel
92 * calculates as a cryptographic hash of the key itself,
93 * matching fscrypt_policy_v2::master_key_identifier.
94 */
95#define FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER 2
96
97/*
98 * Specifies a key, either for v1 or v2 policies. This doesn't contain the
99 * actual key itself; this is just the "name" of the key.
100 */
101struct fscrypt_key_specifier {
102 __u32 type; /* one of FSCRYPT_KEY_SPEC_TYPE_* */
103 __u32 __reserved;
104 union {
105 __u8 __reserved[32]; /* reserve some extra space */
106 __u8 descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
107 __u8 identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
108 } u;
109};
110
111/* Struct passed to FS_IOC_ADD_ENCRYPTION_KEY */
112struct fscrypt_add_key_arg {
113 struct fscrypt_key_specifier key_spec;
114 __u32 raw_size;
115 __u32 __reserved[9];
116 __u8 raw[];
117};
118
119/* Struct passed to FS_IOC_REMOVE_ENCRYPTION_KEY */
120struct fscrypt_remove_key_arg {
121 struct fscrypt_key_specifier key_spec;
122#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY 0x00000001
123#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_OTHER_USERS 0x00000002
124 __u32 removal_status_flags; /* output */
125 __u32 __reserved[5];
126};
127
128/* Struct passed to FS_IOC_GET_ENCRYPTION_KEY_STATUS */
129struct fscrypt_get_key_status_arg {
130 /* input */
131 struct fscrypt_key_specifier key_spec;
132 __u32 __reserved[6];
133
134 /* output */
135#define FSCRYPT_KEY_STATUS_ABSENT 1
136#define FSCRYPT_KEY_STATUS_PRESENT 2
137#define FSCRYPT_KEY_STATUS_INCOMPLETELY_REMOVED 3
138 __u32 status;
139#define FSCRYPT_KEY_STATUS_FLAG_ADDED_BY_SELF 0x00000001
140 __u32 status_flags;
141 __u32 user_count;
142 __u32 __out_reserved[13];
143};
144
145#define FS_IOC_SET_ENCRYPTION_POLICY _IOR('f', 19, struct fscrypt_policy)
146#define FS_IOC_GET_ENCRYPTION_PWSALT _IOW('f', 20, __u8[16])
147#define FS_IOC_GET_ENCRYPTION_POLICY _IOW('f', 21, struct fscrypt_policy)
148#define FS_IOC_GET_ENCRYPTION_POLICY_EX _IOWR('f', 22, __u8[9]) /* size + version */
149#define FS_IOC_ADD_ENCRYPTION_KEY _IOWR('f', 23, struct fscrypt_add_key_arg)
150#define FS_IOC_REMOVE_ENCRYPTION_KEY _IOWR('f', 24, struct fscrypt_remove_key_arg)
151#define FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS _IOWR('f', 25, struct fscrypt_remove_key_arg)
152#define FS_IOC_GET_ENCRYPTION_KEY_STATUS _IOWR('f', 26, struct fscrypt_get_key_status_arg)
153
154/**********************************************************************/
155
156/* old names; don't add anything new here! */
157#ifndef __KERNEL__
158#define FS_KEY_DESCRIPTOR_SIZE FSCRYPT_KEY_DESCRIPTOR_SIZE
159#define FS_POLICY_FLAGS_PAD_4 FSCRYPT_POLICY_FLAGS_PAD_4
160#define FS_POLICY_FLAGS_PAD_8 FSCRYPT_POLICY_FLAGS_PAD_8
161#define FS_POLICY_FLAGS_PAD_16 FSCRYPT_POLICY_FLAGS_PAD_16
162#define FS_POLICY_FLAGS_PAD_32 FSCRYPT_POLICY_FLAGS_PAD_32
163#define FS_POLICY_FLAGS_PAD_MASK FSCRYPT_POLICY_FLAGS_PAD_MASK
164#define FS_POLICY_FLAG_DIRECT_KEY FSCRYPT_POLICY_FLAG_DIRECT_KEY
165#define FS_POLICY_FLAGS_VALID FSCRYPT_POLICY_FLAGS_VALID
166#define FS_ENCRYPTION_MODE_INVALID 0 /* never used */
167#define FS_ENCRYPTION_MODE_AES_256_XTS FSCRYPT_MODE_AES_256_XTS
168#define FS_ENCRYPTION_MODE_AES_256_GCM 2 /* never used */
169#define FS_ENCRYPTION_MODE_AES_256_CBC 3 /* never used */
170#define FS_ENCRYPTION_MODE_AES_256_CTS FSCRYPT_MODE_AES_256_CTS
171#define FS_ENCRYPTION_MODE_AES_128_CBC FSCRYPT_MODE_AES_128_CBC
172#define FS_ENCRYPTION_MODE_AES_128_CTS FSCRYPT_MODE_AES_128_CTS
173#define FS_ENCRYPTION_MODE_SPECK128_256_XTS 7 /* removed */
174#define FS_ENCRYPTION_MODE_SPECK128_256_CTS 8 /* removed */
175#define FS_ENCRYPTION_MODE_ADIANTUM FSCRYPT_MODE_ADIANTUM
176#define FS_KEY_DESC_PREFIX FSCRYPT_KEY_DESC_PREFIX
177#define FS_KEY_DESC_PREFIX_SIZE FSCRYPT_KEY_DESC_PREFIX_SIZE
178#define FS_MAX_KEY_SIZE FSCRYPT_MAX_KEY_SIZE
179#endif /* !__KERNEL__ */
180
181#endif /* _UAPI_LINUX_FSCRYPT_H */