/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
* fscrypt user API
*
* These ioctls can be used on filesystems that support fscrypt. See the
* "User API" section of Documentation/filesystems/fscrypt.rst.
*/
#ifndef _LINUX_FSCRYPT_H
#define _LINUX_FSCRYPT_H
#include <linux/ioctl.h>
#include <linux/types.h>
/* Encryption policy flags */
#define FSCRYPT_POLICY_FLAGS_PAD_4 0x00
#define FSCRYPT_POLICY_FLAGS_PAD_8 0x01
#define FSCRYPT_POLICY_FLAGS_PAD_16 0x02
#define FSCRYPT_POLICY_FLAGS_PAD_32 0x03
#define FSCRYPT_POLICY_FLAGS_PAD_MASK 0x03
#define FSCRYPT_POLICY_FLAG_DIRECT_KEY 0x04
#define FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64 0x08
#define FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32 0x10
/* Encryption algorithms */
#define FSCRYPT_MODE_AES_256_XTS 1
#define FSCRYPT_MODE_AES_256_CTS 4
#define FSCRYPT_MODE_AES_128_CBC 5
#define FSCRYPT_MODE_AES_128_CTS 6
#define FSCRYPT_MODE_SM4_XTS 7
#define FSCRYPT_MODE_SM4_CTS 8
#define FSCRYPT_MODE_ADIANTUM 9
#define FSCRYPT_MODE_AES_256_HCTR2 10
/* If adding a mode number > 10, update FSCRYPT_MODE_MAX in fscrypt_private.h */
/*
* Legacy policy version; ad-hoc KDF and no key verification.
* For new encrypted directories, use fscrypt_policy_v2 instead.
*
* Careful: the .version field for this is actually 0, not 1.
*/
#define FSCRYPT_POLICY_V1 0
#define FSCRYPT_KEY_DESCRIPTOR_SIZE 8
struct fscrypt_policy_v1 {
__u8 version;
__u8 contents_encryption_mode;
__u8 filenames_encryption_mode;
__u8 flags;
__u8 master_key_descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
};
/*
* Process-subscribed "logon" key description prefix and payload format.
* Deprecated; prefer FS_IOC_ADD_ENCRYPTION_KEY instead.
*/
#define FSCRYPT_KEY_DESC_PREFIX "fscrypt:"
#define FSCRYPT_KEY_DESC_PREFIX_SIZE 8
#define FSCRYPT_MAX_KEY_SIZE 64
struct fscrypt_key {
__u32 mode;
__u8 raw[FSCRYPT_MAX_KEY_SIZE];
__u32 size;
};
/*
* New policy version with HKDF and key verification (recommended).
*/
#define FSCRYPT_POLICY_V2 2
#define FSCRYPT_KEY_IDENTIFIER_SIZE 16
struct fscrypt_policy_v2 {
__u8 version;
__u8 contents_encryption_mode;
__u8 filenames_encryption_mode;
__u8 flags;
__u8 __reserved[4];
__u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
};
/* Struct passed to FS_IOC_GET_ENCRYPTION_POLICY_EX */
struct fscrypt_get_policy_ex_arg {
__u64 policy_size; /* input/output */
union {
__u8 version;
struct fscrypt_policy_v1 v1;
struct fscrypt_policy_v2 v2;
} policy; /* output */
};
/*
* v1 policy keys are specified by an arbitrary 8-byte key "descriptor",
* matching fscrypt_policy_v1::master_key_descriptor.
*/
#define FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR 1
/*
* v2 policy keys are specified by a 16-byte key "identifier" which the kernel
* calculates as a cryptographic hash of the key itself,
* matching fscrypt_policy_v2::master_key_identifier.
*/
#define FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER 2
/*
* Specifies a key, either for v1 or v2 policies. This doesn't contain the
* actual key itself; this is just the "name" of the key.
*/
struct fscrypt_key_specifier {
__u32 type; /* one of FSCRYPT_KEY_SPEC_TYPE_* */
__u32 __reserved;
union {
__u8 __reserved[32]; /* reserve some extra space */
__u8 descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
__u8 identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
} u;
};
/*
* Payload of Linux keyring key of type "fscrypt-provisioning", referenced by
* fscrypt_add_key_arg::key_id as an alternative to fscrypt_add_key_arg::raw.
*/
struct fscrypt_provisioning_key_payload {
__u32 type;
__u32 __reserved;
__u8 raw[];
};
/* Struct passed to FS_IOC_ADD_ENCRYPTION_KEY */
struct fscrypt_add_key_arg {
struct fscrypt_key_specifier key_spec;
__u32 raw_size;
__u32 key_id;
__u32 __reserved[8];
__u8 raw[];
};
/* Struct passed to FS_IOC_REMOVE_ENCRYPTION_KEY */
struct fscrypt_remove_key_arg {
struct fscrypt_key_specifier key_spec;
#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY 0x00000001
#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_OTHER_USERS 0x00000002
__u32 removal_status_flags; /* output */
__u32 __reserved[5];
};
/* Struct passed to FS_IOC_GET_ENCRYPTION_KEY_STATUS */
struct fscrypt_get_key_status_arg {
/* input */
struct fscrypt_key_specifier key_spec;
__u32 __reserved[6];
/* output */
#define FSCRYPT_KEY_STATUS_ABSENT 1
#define FSCRYPT_KEY_STATUS_PRESENT 2
#define FSCRYPT_KEY_STATUS_INCOMPLETELY_REMOVED 3
__u32 status;
#define FSCRYPT_KEY_STATUS_FLAG_ADDED_BY_SELF 0x00000001
__u32 status_flags;
__u32 user_count;
__u32 __out_reserved[13];
};
#define FS_IOC_SET_ENCRYPTION_POLICY _IOR('f', 19, struct fscrypt_policy_v1)
#define FS_IOC_GET_ENCRYPTION_PWSALT _IOW('f', 20, __u8[16])
#define FS_IOC_GET_ENCRYPTION_POLICY _IOW('f', 21, struct fscrypt_policy_v1)
#define FS_IOC_GET_ENCRYPTION_POLICY_EX _IOWR('f', 22, __u8[9]) /* size + version */
#define FS_IOC_ADD_ENCRYPTION_KEY _IOWR('f', 23, struct fscrypt_add_key_arg)
#define FS_IOC_REMOVE_ENCRYPTION_KEY _IOWR('f', 24, struct fscrypt_remove_key_arg)
#define FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS _IOWR('f', 25, struct fscrypt_remove_key_arg)
#define FS_IOC_GET_ENCRYPTION_KEY_STATUS _IOWR('f', 26, struct fscrypt_get_key_status_arg)
#define FS_IOC_GET_ENCRYPTION_NONCE _IOR('f', 27, __u8[16])
/**********************************************************************/
/* old names; don't add anything new here! */
#define fscrypt_policy fscrypt_policy_v1
#define FS_KEY_DESCRIPTOR_SIZE FSCRYPT_KEY_DESCRIPTOR_SIZE
#define FS_POLICY_FLAGS_PAD_4 FSCRYPT_POLICY_FLAGS_PAD_4
#define FS_POLICY_FLAGS_PAD_8 FSCRYPT_POLICY_FLAGS_PAD_8
#define FS_POLICY_FLAGS_PAD_16 FSCRYPT_POLICY_FLAGS_PAD_16
#define FS_POLICY_FLAGS_PAD_32 FSCRYPT_POLICY_FLAGS_PAD_32
#define FS_POLICY_FLAGS_PAD_MASK FSCRYPT_POLICY_FLAGS_PAD_MASK
#define FS_POLICY_FLAG_DIRECT_KEY FSCRYPT_POLICY_FLAG_DIRECT_KEY
#define FS_POLICY_FLAGS_VALID 0x07 /* contains old flags only */
#define FS_ENCRYPTION_MODE_INVALID 0 /* never used */
#define FS_ENCRYPTION_MODE_AES_256_XTS FSCRYPT_MODE_AES_256_XTS
#define FS_ENCRYPTION_MODE_AES_256_GCM 2 /* never used */
#define FS_ENCRYPTION_MODE_AES_256_CBC 3 /* never used */
#define FS_ENCRYPTION_MODE_AES_256_CTS FSCRYPT_MODE_AES_256_CTS
#define FS_ENCRYPTION_MODE_AES_128_CBC FSCRYPT_MODE_AES_128_CBC
#define FS_ENCRYPTION_MODE_AES_128_CTS FSCRYPT_MODE_AES_128_CTS
#define FS_ENCRYPTION_MODE_ADIANTUM FSCRYPT_MODE_ADIANTUM
#define FS_KEY_DESC_PREFIX FSCRYPT_KEY_DESC_PREFIX
#define FS_KEY_DESC_PREFIX_SIZE FSCRYPT_KEY_DESC_PREFIX_SIZE
#define FS_MAX_KEY_SIZE FSCRYPT_MAX_KEY_SIZE
#endif /* _LINUX_FSCRYPT_H */
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