/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note *//* * fs-verity user API * * These ioctls can be used on filesystems that support fs-verity.  See the * "User API" section of Documentation/filesystems/fsverity.rst. * * Copyright 2019 Google LLC */#ifndef _UAPI_LINUX_FSVERITY_H#define _UAPI_LINUX_FSVERITY_H #include <linux/ioctl.h>#include <linux/types.h> #define FS_VERITY_HASH_ALG_SHA256	1#define FS_VERITY_HASH_ALG_SHA512	2 struct fsverity_enable_arg {	__u32 version;	__u32 hash_algorithm;	__u32 block_size;	__u32 salt_size;	__u64 salt_ptr;	__u32 sig_size;	__u32 __reserved1;	__u64 sig_ptr;	__u64 __reserved2[11];}; struct fsverity_digest {	__u16 digest_algorithm;	__u16 digest_size; /* input/output */	__u8 digest[];}; /* * Struct containing a file's Merkle tree properties.  The fs-verity file digest * is the hash of this struct.  A userspace program needs this struct only if it * needs to compute fs-verity file digests itself, e.g. in order to sign files. * It isn't needed just to enable fs-verity on a file. * * Note: when computing the file digest, 'sig_size' and 'signature' must be left * zero and empty, respectively.  These fields are present only because some * filesystems reuse this struct as part of their on-disk format. */struct fsverity_descriptor {	__u8 version;		/* must be 1 */	__u8 hash_algorithm;	/* Merkle tree hash algorithm */	__u8 log_blocksize;	/* log2 of size of data and tree blocks */	__u8 salt_size;		/* size of salt in bytes; 0 if none */#ifdef __KERNEL__	__le32 sig_size;#else	__le32 __reserved_0x04;	/* must be 0 */#endif	__le64 data_size;	/* size of file the Merkle tree is built over */	__u8 root_hash[64];	/* Merkle tree root hash */	__u8 salt[32];		/* salt prepended to each hashed block */	__u8 __reserved[144];	/* must be 0's */#ifdef __KERNEL__	__u8 signature[];#endif}; /* * Format in which fs-verity file digests are signed in built-in signatures. * This is the same as 'struct fsverity_digest', except here some magic bytes * are prepended to provide some context about what is being signed in case the * same key is used for non-fsverity purposes, and here the fields have fixed * endianness. * * This struct is specific to the built-in signature verification support, which * is optional.  fs-verity users may also verify signatures in userspace, in * which case userspace is responsible for deciding on what bytes are signed. * This struct may still be used, but it doesn't have to be.  For example, * userspace could instead use a string like "sha256:$digest_as_hex_string". */struct fsverity_formatted_digest {	char magic[8];			/* must be "FSVerity" */	__le16 digest_algorithm;	__le16 digest_size;	__u8 digest[];}; #define FS_IOC_ENABLE_VERITY	_IOW('f', 133, struct fsverity_enable_arg)#define FS_IOC_MEASURE_VERITY	_IOWR('f', 134, struct fsverity_digest) #endif /* _UAPI_LINUX_FSVERITY_H */