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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
49/*
50 * Process-subscribed "logon" key description prefix and payload format.
51 * Deprecated; prefer FS_IOC_ADD_ENCRYPTION_KEY instead.
52 */
53#define FSCRYPT_KEY_DESC_PREFIX "fscrypt:"
54#define FSCRYPT_KEY_DESC_PREFIX_SIZE 8
55#define FSCRYPT_MAX_KEY_SIZE 64
56struct fscrypt_key {
57 __u32 mode;
58 __u8 raw[FSCRYPT_MAX_KEY_SIZE];
59 __u32 size;
60};
61
62/*
63 * New policy version with HKDF and key verification (recommended).
64 */
65#define FSCRYPT_POLICY_V2 2
66#define FSCRYPT_KEY_IDENTIFIER_SIZE 16
67struct fscrypt_policy_v2 {
68 __u8 version;
69 __u8 contents_encryption_mode;
70 __u8 filenames_encryption_mode;
71 __u8 flags;
72 __u8 __reserved[4];
73 __u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
74};
75
76/* Struct passed to FS_IOC_GET_ENCRYPTION_POLICY_EX */
77struct fscrypt_get_policy_ex_arg {
78 __u64 policy_size; /* input/output */
79 union {
80 __u8 version;
81 struct fscrypt_policy_v1 v1;
82 struct fscrypt_policy_v2 v2;
83 } policy; /* output */
84};
85
86/*
87 * v1 policy keys are specified by an arbitrary 8-byte key "descriptor",
88 * matching fscrypt_policy_v1::master_key_descriptor.
89 */
90#define FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR 1
91
92/*
93 * v2 policy keys are specified by a 16-byte key "identifier" which the kernel
94 * calculates as a cryptographic hash of the key itself,
95 * matching fscrypt_policy_v2::master_key_identifier.
96 */
97#define FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER 2
98
99/*
100 * Specifies a key, either for v1 or v2 policies. This doesn't contain the
101 * actual key itself; this is just the "name" of the key.
102 */
103struct fscrypt_key_specifier {
104 __u32 type; /* one of FSCRYPT_KEY_SPEC_TYPE_* */
105 __u32 __reserved;
106 union {
107 __u8 __reserved[32]; /* reserve some extra space */
108 __u8 descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
109 __u8 identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
110 } u;
111};
112
113/*
114 * Payload of Linux keyring key of type "fscrypt-provisioning", referenced by
115 * fscrypt_add_key_arg::key_id as an alternative to fscrypt_add_key_arg::raw.
116 */
117struct fscrypt_provisioning_key_payload {
118 __u32 type;
119 __u32 __reserved;
120 __u8 raw[];
121};
122
123/* Struct passed to FS_IOC_ADD_ENCRYPTION_KEY */
124struct fscrypt_add_key_arg {
125 struct fscrypt_key_specifier key_spec;
126 __u32 raw_size;
127 __u32 key_id;
128 __u32 __reserved[8];
129 __u8 raw[];
130};
131
132/* Struct passed to FS_IOC_REMOVE_ENCRYPTION_KEY */
133struct fscrypt_remove_key_arg {
134 struct fscrypt_key_specifier key_spec;
135#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY 0x00000001
136#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_OTHER_USERS 0x00000002
137 __u32 removal_status_flags; /* output */
138 __u32 __reserved[5];
139};
140
141/* Struct passed to FS_IOC_GET_ENCRYPTION_KEY_STATUS */
142struct fscrypt_get_key_status_arg {
143 /* input */
144 struct fscrypt_key_specifier key_spec;
145 __u32 __reserved[6];
146
147 /* output */
148#define FSCRYPT_KEY_STATUS_ABSENT 1
149#define FSCRYPT_KEY_STATUS_PRESENT 2
150#define FSCRYPT_KEY_STATUS_INCOMPLETELY_REMOVED 3
151 __u32 status;
152#define FSCRYPT_KEY_STATUS_FLAG_ADDED_BY_SELF 0x00000001
153 __u32 status_flags;
154 __u32 user_count;
155 __u32 __out_reserved[13];
156};
157
158#define FS_IOC_SET_ENCRYPTION_POLICY _IOR('f', 19, struct fscrypt_policy_v1)
159#define FS_IOC_GET_ENCRYPTION_PWSALT _IOW('f', 20, __u8[16])
160#define FS_IOC_GET_ENCRYPTION_POLICY _IOW('f', 21, struct fscrypt_policy_v1)
161#define FS_IOC_GET_ENCRYPTION_POLICY_EX _IOWR('f', 22, __u8[9]) /* size + version */
162#define FS_IOC_ADD_ENCRYPTION_KEY _IOWR('f', 23, struct fscrypt_add_key_arg)
163#define FS_IOC_REMOVE_ENCRYPTION_KEY _IOWR('f', 24, struct fscrypt_remove_key_arg)
164#define FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS _IOWR('f', 25, struct fscrypt_remove_key_arg)
165#define FS_IOC_GET_ENCRYPTION_KEY_STATUS _IOWR('f', 26, struct fscrypt_get_key_status_arg)
166#define FS_IOC_GET_ENCRYPTION_NONCE _IOR('f', 27, __u8[16])
167
168/**********************************************************************/
169
170/* old names; don't add anything new here! */
171#ifndef __KERNEL__
172#define fscrypt_policy fscrypt_policy_v1
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 */