Re: [PATCH 3/9] Move fsverity_descriptor definition to libfsverity.h

[Eric Biggers <ebiggers@kernel.org>]

On Thu, Mar 12, 2020 at 05:47:52PM -0400, Jes Sorensen wrote:
> From: Jes Sorensen <jsorensen@fb.com>
> 
> Signed-off-by: Jes Sorensen <jsorensen@fb.com>
> ---
>  cmd_sign.c    | 19 +------------------
>  libfsverity.h | 26 +++++++++++++++++++++++++-
>  2 files changed, 26 insertions(+), 19 deletions(-)
> 
> diff --git a/cmd_sign.c b/cmd_sign.c
> index dcc44f8..1792084 100644
> --- a/cmd_sign.c
> +++ b/cmd_sign.c
> @@ -20,26 +20,9 @@
>  #include <unistd.h>
>  
>  #include "commands.h"
> -#include "fsverity_uapi.h"
> +#include "libfsverity.h"
>  #include "hash_algs.h"
>  
> -/*
> - * Merkle tree properties.  The file measurement is the hash of this structure
> - * excluding the signature and with the sig_size field set to 0.
> - */
> -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 */
> -	__le32 sig_size;	/* size of signature in bytes; 0 if none */
> -	__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 */
> -	__u8 signature[];	/* optional PKCS#7 signature */
> -};
> -
>  /*
>   * Format in which verity file measurements are signed.  This is the same as
>   * 'struct fsverity_digest', except here some magic bytes are prepended to
> diff --git a/libfsverity.h b/libfsverity.h
> index ceebae1..396a6ee 100644
> --- a/libfsverity.h
> +++ b/libfsverity.h
> @@ -13,13 +13,14 @@
>  
>  #include <stddef.h>
>  #include <stdint.h>
> +#include <linux/types.h>
>  
>  #define FS_VERITY_HASH_ALG_SHA256       1
>  #define FS_VERITY_HASH_ALG_SHA512       2
>  
>  struct libfsverity_merkle_tree_params {
>  	uint16_t version;
> -	uint16_t hash_algorithm;
> +	uint16_t hash_algorithm;	/* Matches the digest_algorithm type */
>  	uint32_t block_size;
>  	uint32_t salt_size;
>  	const uint8_t *salt;
> @@ -27,6 +28,7 @@ struct libfsverity_merkle_tree_params {
>  };
>  
>  struct libfsverity_digest {
> +	char magic[8];			/* must be "FSVerity" */
>  	uint16_t digest_algorithm;
>  	uint16_t digest_size;
>  	uint8_t digest[];
> @@ -38,4 +40,26 @@ struct libfsverity_signature_params {
>  	uint64_t reserved[11];
>  };
>  
> +/*
> + * Merkle tree properties.  The file measurement is the hash of this structure
> + * excluding the signature and with the sig_size field set to 0.
> + */
> +struct fsverity_descriptor {
> +	uint8_t version;	/* must be 1 */
> +	uint8_t hash_algorithm;	/* Merkle tree hash algorithm */
> +	uint8_t log_blocksize;	/* log2 of size of data and tree blocks */
> +	uint8_t salt_size;	/* size of salt in bytes; 0 if none */
> +	__le32 sig_size;	/* size of signature in bytes; 0 if none */
> +	__le64 data_size;	/* size of file the Merkle tree is built over */
> +	uint8_t root_hash[64];	/* Merkle tree root hash */
> +	uint8_t salt[32];	/* salt prepended to each hashed block */
> +	uint8_t __reserved[144];/* must be 0's */
> +	uint8_t signature[];	/* optional PKCS#7 signature */
> +};
> +

I thought there was no need for this to be part of the library API?

- Eric