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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_FLAG_IV_INO_LBLK_64 0x08
21#define FSCRYPT_POLICY_FLAGS_VALID 0x0F
22
23/* Encryption algorithms */
24#define FSCRYPT_MODE_AES_256_XTS 1
25#define FSCRYPT_MODE_AES_256_CTS 4
26#define FSCRYPT_MODE_AES_128_CBC 5
27#define FSCRYPT_MODE_AES_128_CTS 6
28#define FSCRYPT_MODE_ADIANTUM 9
29#define __FSCRYPT_MODE_MAX 9
30
31/*
32 * Legacy policy version; ad-hoc KDF and no key verification.
33 * For new encrypted directories, use fscrypt_policy_v2 instead.
34 *
35 * Careful: the .version field for this is actually 0, not 1.
36 */
37#define FSCRYPT_POLICY_V1 0
38#define FSCRYPT_KEY_DESCRIPTOR_SIZE 8
39struct fscrypt_policy_v1 {
40 __u8 version;
41 __u8 contents_encryption_mode;
42 __u8 filenames_encryption_mode;
43 __u8 flags;
44 __u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
45};
46#define fscrypt_policy fscrypt_policy_v1
47
48/*
49 * Process-subscribed "logon" key description prefix and payload format.
50 * Deprecated; prefer FS_IOC_ADD_ENCRYPTION_KEY instead.
51 */
52#define FSCRYPT_KEY_DESC_PREFIX "fscrypt:"
53#define FSCRYPT_KEY_DESC_PREFIX_SIZE 8
54#define FSCRYPT_MAX_KEY_SIZE 64
55struct fscrypt_key {
56 __u32 mode;
57 __u8 raw[FSCRYPT_MAX_KEY_SIZE];
58 __u32 size;
59};
60
61/*
62 * New policy version with HKDF and key verification (recommended).
63 */
64#define FSCRYPT_POLICY_V2 2
65#define FSCRYPT_KEY_IDENTIFIER_SIZE 16
66struct fscrypt_policy_v2 {
67 __u8 version;
68 __u8 contents_encryption_mode;
69 __u8 filenames_encryption_mode;
70 __u8 flags;
71 __u8 __reserved[4];
72 __u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
73};
74
75/* Struct passed to FS_IOC_GET_ENCRYPTION_POLICY_EX */
76struct fscrypt_get_policy_ex_arg {
77 __u64 policy_size; /* input/output */
78 union {
79 __u8 version;
80 struct fscrypt_policy_v1 v1;
81 struct fscrypt_policy_v2 v2;
82 } policy; /* output */
83};
84
85/*
86 * v1 policy keys are specified by an arbitrary 8-byte key "descriptor",
87 * matching fscrypt_policy_v1::master_key_descriptor.
88 */
89#define FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR 1
90
91/*
92 * v2 policy keys are specified by a 16-byte key "identifier" which the kernel
93 * calculates as a cryptographic hash of the key itself,
94 * matching fscrypt_policy_v2::master_key_identifier.
95 */
96#define FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER 2
97
98/*
99 * Specifies a key, either for v1 or v2 policies. This doesn't contain the
100 * actual key itself; this is just the "name" of the key.
101 */
102struct fscrypt_key_specifier {
103 __u32 type; /* one of FSCRYPT_KEY_SPEC_TYPE_* */
104 __u32 __reserved;
105 union {
106 __u8 __reserved[32]; /* reserve some extra space */
107 __u8 descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
108 __u8 identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
109 } u;
110};
111
112/* Struct passed to FS_IOC_ADD_ENCRYPTION_KEY */
113struct fscrypt_add_key_arg {
114 struct fscrypt_key_specifier key_spec;
115 __u32 raw_size;
116 __u32 __reserved[9];
117 __u8 raw[];
118};
119
120/* Struct passed to FS_IOC_REMOVE_ENCRYPTION_KEY */
121struct fscrypt_remove_key_arg {
122 struct fscrypt_key_specifier key_spec;
123#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY 0x00000001
124#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_OTHER_USERS 0x00000002
125 __u32 removal_status_flags; /* output */
126 __u32 __reserved[5];
127};
128
129/* Struct passed to FS_IOC_GET_ENCRYPTION_KEY_STATUS */
130struct fscrypt_get_key_status_arg {
131 /* input */
132 struct fscrypt_key_specifier key_spec;
133 __u32 __reserved[6];
134
135 /* output */
136#define FSCRYPT_KEY_STATUS_ABSENT 1
137#define FSCRYPT_KEY_STATUS_PRESENT 2
138#define FSCRYPT_KEY_STATUS_INCOMPLETELY_REMOVED 3
139 __u32 status;
140#define FSCRYPT_KEY_STATUS_FLAG_ADDED_BY_SELF 0x00000001
141 __u32 status_flags;
142 __u32 user_count;
143 __u32 __out_reserved[13];
144};
145
146#define FS_IOC_SET_ENCRYPTION_POLICY _IOR('f', 19, struct fscrypt_policy)
147#define FS_IOC_GET_ENCRYPTION_PWSALT _IOW('f', 20, __u8[16])
148#define FS_IOC_GET_ENCRYPTION_POLICY _IOW('f', 21, struct fscrypt_policy)
149#define FS_IOC_GET_ENCRYPTION_POLICY_EX _IOWR('f', 22, __u8[9]) /* size + version */
150#define FS_IOC_ADD_ENCRYPTION_KEY _IOWR('f', 23, struct fscrypt_add_key_arg)
151#define FS_IOC_REMOVE_ENCRYPTION_KEY _IOWR('f', 24, struct fscrypt_remove_key_arg)
152#define FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS _IOWR('f', 25, struct fscrypt_remove_key_arg)
153#define FS_IOC_GET_ENCRYPTION_KEY_STATUS _IOWR('f', 26, struct fscrypt_get_key_status_arg)
154
155/**********************************************************************/
156
157/* old names; don't add anything new here! */
158#ifndef __KERNEL__
159#define FS_KEY_DESCRIPTOR_SIZE FSCRYPT_KEY_DESCRIPTOR_SIZE
160#define FS_POLICY_FLAGS_PAD_4 FSCRYPT_POLICY_FLAGS_PAD_4
161#define FS_POLICY_FLAGS_PAD_8 FSCRYPT_POLICY_FLAGS_PAD_8
162#define FS_POLICY_FLAGS_PAD_16 FSCRYPT_POLICY_FLAGS_PAD_16
163#define FS_POLICY_FLAGS_PAD_32 FSCRYPT_POLICY_FLAGS_PAD_32
164#define FS_POLICY_FLAGS_PAD_MASK FSCRYPT_POLICY_FLAGS_PAD_MASK
165#define FS_POLICY_FLAG_DIRECT_KEY FSCRYPT_POLICY_FLAG_DIRECT_KEY
166#define FS_POLICY_FLAGS_VALID FSCRYPT_POLICY_FLAGS_VALID
167#define FS_ENCRYPTION_MODE_INVALID 0 /* never used */
168#define FS_ENCRYPTION_MODE_AES_256_XTS FSCRYPT_MODE_AES_256_XTS
169#define FS_ENCRYPTION_MODE_AES_256_GCM 2 /* never used */
170#define FS_ENCRYPTION_MODE_AES_256_CBC 3 /* never used */
171#define FS_ENCRYPTION_MODE_AES_256_CTS FSCRYPT_MODE_AES_256_CTS
172#define FS_ENCRYPTION_MODE_AES_128_CBC FSCRYPT_MODE_AES_128_CBC
173#define FS_ENCRYPTION_MODE_AES_128_CTS FSCRYPT_MODE_AES_128_CTS
174#define FS_ENCRYPTION_MODE_SPECK128_256_XTS 7 /* removed */
175#define FS_ENCRYPTION_MODE_SPECK128_256_CTS 8 /* removed */
176#define FS_ENCRYPTION_MODE_ADIANTUM FSCRYPT_MODE_ADIANTUM
177#define FS_KEY_DESC_PREFIX FSCRYPT_KEY_DESC_PREFIX
178#define FS_KEY_DESC_PREFIX_SIZE FSCRYPT_KEY_DESC_PREFIX_SIZE
179#define FS_MAX_KEY_SIZE FSCRYPT_MAX_KEY_SIZE
180#endif /* !__KERNEL__ */
181
182#endif /* _UAPI_LINUX_FSCRYPT_H */