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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/ioctl.h>
12#include <linux/types.h>
13
14/* Encryption policy flags */
15#define FSCRYPT_POLICY_FLAGS_PAD_4 0x00
16#define FSCRYPT_POLICY_FLAGS_PAD_8 0x01
17#define FSCRYPT_POLICY_FLAGS_PAD_16 0x02
18#define FSCRYPT_POLICY_FLAGS_PAD_32 0x03
19#define FSCRYPT_POLICY_FLAGS_PAD_MASK 0x03
20#define FSCRYPT_POLICY_FLAG_DIRECT_KEY 0x04
21#define FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64 0x08
22#define FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32 0x10
23#define FSCRYPT_POLICY_FLAGS_VALID 0x1F
24
25/* Encryption algorithms */
26#define FSCRYPT_MODE_AES_256_XTS 1
27#define FSCRYPT_MODE_AES_256_CTS 4
28#define FSCRYPT_MODE_AES_128_CBC 5
29#define FSCRYPT_MODE_AES_128_CTS 6
30#define FSCRYPT_MODE_ADIANTUM 9
31#define __FSCRYPT_MODE_MAX 9
32
33/*
34 * Legacy policy version; ad-hoc KDF and no key verification.
35 * For new encrypted directories, use fscrypt_policy_v2 instead.
36 *
37 * Careful: the .version field for this is actually 0, not 1.
38 */
39#define FSCRYPT_POLICY_V1 0
40#define FSCRYPT_KEY_DESCRIPTOR_SIZE 8
41struct fscrypt_policy_v1 {
42 __u8 version;
43 __u8 contents_encryption_mode;
44 __u8 filenames_encryption_mode;
45 __u8 flags;
46 __u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
47};
48#define fscrypt_policy fscrypt_policy_v1
49
50/*
51 * Process-subscribed "logon" key description prefix and payload format.
52 * Deprecated; prefer FS_IOC_ADD_ENCRYPTION_KEY instead.
53 */
54#define FSCRYPT_KEY_DESC_PREFIX "fscrypt:"
55#define FSCRYPT_KEY_DESC_PREFIX_SIZE 8
56#define FSCRYPT_MAX_KEY_SIZE 64
57struct fscrypt_key {
58 __u32 mode;
59 __u8 raw[FSCRYPT_MAX_KEY_SIZE];
60 __u32 size;
61};
62
63/*
64 * New policy version with HKDF and key verification (recommended).
65 */
66#define FSCRYPT_POLICY_V2 2
67#define FSCRYPT_KEY_IDENTIFIER_SIZE 16
68struct fscrypt_policy_v2 {
69 __u8 version;
70 __u8 contents_encryption_mode;
71 __u8 filenames_encryption_mode;
72 __u8 flags;
73 __u8 __reserved[4];
74 __u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
75};
76
77/* Struct passed to FS_IOC_GET_ENCRYPTION_POLICY_EX */
78struct fscrypt_get_policy_ex_arg {
79 __u64 policy_size; /* input/output */
80 union {
81 __u8 version;
82 struct fscrypt_policy_v1 v1;
83 struct fscrypt_policy_v2 v2;
84 } policy; /* output */
85};
86
87/*
88 * v1 policy keys are specified by an arbitrary 8-byte key "descriptor",
89 * matching fscrypt_policy_v1::master_key_descriptor.
90 */
91#define FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR 1
92
93/*
94 * v2 policy keys are specified by a 16-byte key "identifier" which the kernel
95 * calculates as a cryptographic hash of the key itself,
96 * matching fscrypt_policy_v2::master_key_identifier.
97 */
98#define FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER 2
99
100/*
101 * Specifies a key, either for v1 or v2 policies. This doesn't contain the
102 * actual key itself; this is just the "name" of the key.
103 */
104struct fscrypt_key_specifier {
105 __u32 type; /* one of FSCRYPT_KEY_SPEC_TYPE_* */
106 __u32 __reserved;
107 union {
108 __u8 __reserved[32]; /* reserve some extra space */
109 __u8 descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
110 __u8 identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
111 } u;
112};
113
114/*
115 * Payload of Linux keyring key of type "fscrypt-provisioning", referenced by
116 * fscrypt_add_key_arg::key_id as an alternative to fscrypt_add_key_arg::raw.
117 */
118struct fscrypt_provisioning_key_payload {
119 __u32 type;
120 __u32 __reserved;
121 __u8 raw[];
122};
123
124/* Struct passed to FS_IOC_ADD_ENCRYPTION_KEY */
125struct fscrypt_add_key_arg {
126 struct fscrypt_key_specifier key_spec;
127 __u32 raw_size;
128 __u32 key_id;
129 __u32 __reserved[8];
130 __u8 raw[];
131};
132
133/* Struct passed to FS_IOC_REMOVE_ENCRYPTION_KEY */
134struct fscrypt_remove_key_arg {
135 struct fscrypt_key_specifier key_spec;
136#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY 0x00000001
137#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_OTHER_USERS 0x00000002
138 __u32 removal_status_flags; /* output */
139 __u32 __reserved[5];
140};
141
142/* Struct passed to FS_IOC_GET_ENCRYPTION_KEY_STATUS */
143struct fscrypt_get_key_status_arg {
144 /* input */
145 struct fscrypt_key_specifier key_spec;
146 __u32 __reserved[6];
147
148 /* output */
149#define FSCRYPT_KEY_STATUS_ABSENT 1
150#define FSCRYPT_KEY_STATUS_PRESENT 2
151#define FSCRYPT_KEY_STATUS_INCOMPLETELY_REMOVED 3
152 __u32 status;
153#define FSCRYPT_KEY_STATUS_FLAG_ADDED_BY_SELF 0x00000001
154 __u32 status_flags;
155 __u32 user_count;
156 __u32 __out_reserved[13];
157};
158
159#define FS_IOC_SET_ENCRYPTION_POLICY _IOR('f', 19, struct fscrypt_policy)
160#define FS_IOC_GET_ENCRYPTION_PWSALT _IOW('f', 20, __u8[16])
161#define FS_IOC_GET_ENCRYPTION_POLICY _IOW('f', 21, struct fscrypt_policy)
162#define FS_IOC_GET_ENCRYPTION_POLICY_EX _IOWR('f', 22, __u8[9]) /* size + version */
163#define FS_IOC_ADD_ENCRYPTION_KEY _IOWR('f', 23, struct fscrypt_add_key_arg)
164#define FS_IOC_REMOVE_ENCRYPTION_KEY _IOWR('f', 24, struct fscrypt_remove_key_arg)
165#define FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS _IOWR('f', 25, struct fscrypt_remove_key_arg)
166#define FS_IOC_GET_ENCRYPTION_KEY_STATUS _IOWR('f', 26, struct fscrypt_get_key_status_arg)
167#define FS_IOC_GET_ENCRYPTION_NONCE _IOR('f', 27, __u8[16])
168
169/**********************************************************************/
170
171/* old names; don't add anything new here! */
172#ifndef __KERNEL__
173#define FS_KEY_DESCRIPTOR_SIZE FSCRYPT_KEY_DESCRIPTOR_SIZE
174#define FS_POLICY_FLAGS_PAD_4 FSCRYPT_POLICY_FLAGS_PAD_4
175#define FS_POLICY_FLAGS_PAD_8 FSCRYPT_POLICY_FLAGS_PAD_8
176#define FS_POLICY_FLAGS_PAD_16 FSCRYPT_POLICY_FLAGS_PAD_16
177#define FS_POLICY_FLAGS_PAD_32 FSCRYPT_POLICY_FLAGS_PAD_32
178#define FS_POLICY_FLAGS_PAD_MASK FSCRYPT_POLICY_FLAGS_PAD_MASK
179#define FS_POLICY_FLAG_DIRECT_KEY FSCRYPT_POLICY_FLAG_DIRECT_KEY
180#define FS_POLICY_FLAGS_VALID FSCRYPT_POLICY_FLAGS_VALID
181#define FS_ENCRYPTION_MODE_INVALID 0 /* never used */
182#define FS_ENCRYPTION_MODE_AES_256_XTS FSCRYPT_MODE_AES_256_XTS
183#define FS_ENCRYPTION_MODE_AES_256_GCM 2 /* never used */
184#define FS_ENCRYPTION_MODE_AES_256_CBC 3 /* never used */
185#define FS_ENCRYPTION_MODE_AES_256_CTS FSCRYPT_MODE_AES_256_CTS
186#define FS_ENCRYPTION_MODE_AES_128_CBC FSCRYPT_MODE_AES_128_CBC
187#define FS_ENCRYPTION_MODE_AES_128_CTS FSCRYPT_MODE_AES_128_CTS
188#define FS_ENCRYPTION_MODE_SPECK128_256_XTS 7 /* removed */
189#define FS_ENCRYPTION_MODE_SPECK128_256_CTS 8 /* removed */
190#define FS_ENCRYPTION_MODE_ADIANTUM FSCRYPT_MODE_ADIANTUM
191#define FS_KEY_DESC_PREFIX FSCRYPT_KEY_DESC_PREFIX
192#define FS_KEY_DESC_PREFIX_SIZE FSCRYPT_KEY_DESC_PREFIX_SIZE
193#define FS_MAX_KEY_SIZE FSCRYPT_MAX_KEY_SIZE
194#endif /* !__KERNEL__ */
195
196#endif /* _UAPI_LINUX_FSCRYPT_H */