On 06/20, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@xxxxxxxxxx>
>
> Add SHA-512 support to fs-verity. This is primarily a demonstration of
> the trivial changes needed to support a new hash algorithm in fs-verity;
> most users will still use SHA-256, due to the smaller space required to
> store the hashes. But some users may prefer SHA-512.
>
> Reviewed-by: Theodore Ts'o <tytso@xxxxxxx>
Reviewed-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
> ---
> fs/verity/fsverity_private.h | 2 +-
> fs/verity/hash_algs.c | 5 +++++
> include/uapi/linux/fsverity.h | 1 +
> 3 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/fs/verity/fsverity_private.h b/fs/verity/fsverity_private.h
> index eaa2b3b93bbf6b..02a547f0667c13 100644
> --- a/fs/verity/fsverity_private.h
> +++ b/fs/verity/fsverity_private.h
> @@ -29,7 +29,7 @@ struct ahash_request;
> * Largest digest size among all hash algorithms supported by fs-verity.
> * Currently assumed to be <= size of fsverity_descriptor::root_hash.
> */
> -#define FS_VERITY_MAX_DIGEST_SIZE SHA256_DIGEST_SIZE
> +#define FS_VERITY_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE
>
> /* A hash algorithm supported by fs-verity */
> struct fsverity_hash_alg {
> diff --git a/fs/verity/hash_algs.c b/fs/verity/hash_algs.c
> index 46df17094fc252..e0462a010cabfb 100644
> --- a/fs/verity/hash_algs.c
> +++ b/fs/verity/hash_algs.c
> @@ -17,6 +17,11 @@ struct fsverity_hash_alg fsverity_hash_algs[] = {
> .digest_size = SHA256_DIGEST_SIZE,
> .block_size = SHA256_BLOCK_SIZE,
> },
> + [FS_VERITY_HASH_ALG_SHA512] = {
> + .name = "sha512",
> + .digest_size = SHA512_DIGEST_SIZE,
> + .block_size = SHA512_BLOCK_SIZE,
> + },
> };
>
> /**
> diff --git a/include/uapi/linux/fsverity.h b/include/uapi/linux/fsverity.h
> index 57d1d7fc0c345a..da0daf6c193b4b 100644
> --- a/include/uapi/linux/fsverity.h
> +++ b/include/uapi/linux/fsverity.h
> @@ -14,6 +14,7 @@
> #include <linux/types.h>
>
> #define FS_VERITY_HASH_ALG_SHA256 1
> +#define FS_VERITY_HASH_ALG_SHA512 2
>
> struct fsverity_enable_arg {
> __u32 version;
> --
> 2.22.0.410.gd8fdbe21b5-goog
