root/include/uapi/linux/fscrypt.h

INCLUDED FROM

   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
  38 struct 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
  54 struct 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
  65 struct 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 */
  75 struct 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  */
 101 struct 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 */
 112 struct 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 */
 120 struct 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 */
 129 struct 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 */