sys/linux/fscrypt.txt

# Copyright 2019 syzkaller project authors. All rights reserved.
# Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.

include <uapi/linux/fs.h>
include <uapi/linux/fscrypt.h>

ioctl$FS_IOC_SET_ENCRYPTION_POLICY(fd fd, cmd const[FS_IOC_SET_ENCRYPTION_POLICY], arg ptr[in, fscrypt_policy])
ioctl$FS_IOC_GET_ENCRYPTION_PWSALT(fd fd, cmd const[FS_IOC_GET_ENCRYPTION_PWSALT], arg ptr[out, array[int8, 16]])
ioctl$FS_IOC_GET_ENCRYPTION_POLICY(fd fd, cmd const[FS_IOC_GET_ENCRYPTION_POLICY], arg ptr[out, fscrypt_policy_v1])
ioctl$FS_IOC_GET_ENCRYPTION_POLICY_EX(fd fd, cmd const[FS_IOC_GET_ENCRYPTION_POLICY_EX], arg ptr[inout, fscrypt_get_policy_ex_arg])
ioctl$FS_IOC_ADD_ENCRYPTION_KEY(fd fd, cmd const[FS_IOC_ADD_ENCRYPTION_KEY], arg ptr[inout, fscrypt_add_key_arg])
ioctl$FS_IOC_REMOVE_ENCRYPTION_KEY(fd fd, cmd const[FS_IOC_REMOVE_ENCRYPTION_KEY], arg ptr[inout, fscrypt_remove_key_arg])
ioctl$FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS(fd fd, cmd const[FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS], arg ptr[inout, fscrypt_remove_key_arg])
ioctl$FS_IOC_GET_ENCRYPTION_KEY_STATUS(fd fd, cmd const[FS_IOC_GET_ENCRYPTION_KEY_STATUS], arg ptr[inout, fscrypt_get_key_status_arg])

type fscrypt_key_descriptor array[int8, FSCRYPT_KEY_DESCRIPTOR_SIZE]
type fscrypt_key_identifier array[int8, FSCRYPT_KEY_IDENTIFIER_SIZE]

fscrypt_policy_v1 {
	version			const[0, int8]
	modes			fscrypt_policy_modes
	flags			flags[fscrypt_policy_flags, int8]
	master_key_descriptor	fscrypt_key_descriptor
}

fscrypt_policy_v2 {
	version			const[2, int8]
	modes			fscrypt_policy_modes
	flags			flags[fscrypt_policy_flags, int8]
	reserved		array[const[0, int8], 4]
	master_key_identifier	fscrypt_key_identifier
}

fscrypt_policy [
	v1	fscrypt_policy_v1
	v2	fscrypt_policy_v2
] [varlen]

fscrypt_policy_modes [
	aes256		fscrypt_policy_mode_t[FSCRYPT_MODE_AES_256_XTS, FSCRYPT_MODE_AES_256_CTS]
	aes128		fscrypt_policy_mode_t[FSCRYPT_MODE_AES_128_CBC, FSCRYPT_MODE_AES_128_CTS]
	adiantum	fscrypt_policy_mode_t[FSCRYPT_MODE_ADIANTUM, FSCRYPT_MODE_ADIANTUM]
]

type fscrypt_policy_mode_t[CONTENTS, FILENAMES] {
	contents_encryption_mode	const[CONTENTS, int8]
	filenames_encryption_mode	const[FILENAMES, int8]
}

fscrypt_policy_flags = FSCRYPT_POLICY_FLAGS_PAD_4, FSCRYPT_POLICY_FLAGS_PAD_8, FSCRYPT_POLICY_FLAGS_PAD_16, FSCRYPT_POLICY_FLAGS_PAD_32, FSCRYPT_POLICY_FLAG_DIRECT_KEY

fscrypt_get_policy_ex_arg {
	policy_size	len[policy, int64]
# policy is an output field, so just leave it zeroed.
	policy		array[const[0, int8]]
}

fscrypt_key_specifier {
	type		flags[fscrypt_key_specifier_type, int32]
	reserved	const[0, int32]
	u		fscrypt_key_specifier_payload
}

fscrypt_key_specifier_type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR, FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER

fscrypt_key_specifier_payload [
	reserved	array[int8, 32]
	descriptor	fscrypt_key_descriptor
	identifier	fscrypt_key_identifier
]

fscrypt_add_key_arg {
	key_spec	fscrypt_key_specifier
	raw_size	len[raw, int32]
	reserved	array[const[0, int32], 9]
	raw		array[int8]
}

fscrypt_remove_key_arg {
	key_spec		fscrypt_key_specifier
# removal_status_flags is an output field, so just leave it zeroed.
	removal_status_flags	const[0, int32]
	reserved		array[const[0, int32], 5]
}

fscrypt_get_key_status_arg {
	key_spec	fscrypt_key_specifier
	reserved	array[const[0, int32], 6]

# The following are output fields, so just leave them zeroed.
	status		const[0, int32]
	status_flags	const[0, int32]
	user_count	const[0, int32]
	out_reserved	array[const[0, int32], 13]
}