[PATCH 4/7] digest: add verify callback

[Sascha Hauer]

On Thu, Mar 12, 2015 at 03:22:23PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> this will allow to compare a md with the original one
> 
> When calling this do not call final
> 
> For RSA_SIGN verification final does not exist only verify
> as final will be for signing
> 
> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
> ---
>  crypto/digest.c   | 23 ++++++++++++++++++++++-
>  crypto/hmac.c     |  1 +
>  crypto/internal.h |  2 ++
>  crypto/md5.c      |  1 +
>  crypto/sha1.c     |  1 +
>  crypto/sha2.c     |  2 ++
>  crypto/sha4.c     |  2 ++
>  include/digest.h  |  6 ++++++
>  8 files changed, 37 insertions(+), 1 deletion(-)
> 
> diff --git a/crypto/digest.c b/crypto/digest.c
> index c06089d..98c3607 100644
> --- a/crypto/digest.c
> +++ b/crypto/digest.c
> @@ -26,6 +26,8 @@
>  #include <module.h>
>  #include <linux/err.h>
>  
> +#include "internal.h"
> +
>  static LIST_HEAD(digests);
>  
>  static struct digest_algo *digest_algo_get_by_name(const char *name);
> @@ -37,9 +39,28 @@ static int dummy_init(struct digest *d)
>  
>  static void dummy_free(struct digest *d) {}
>  
> +int digest_generic_verity(struct digest *d, const unsigned char *md)

s/verity/verify/

> +{
> +	int ret;
> +	int len = digest_length(d);
> +	unsigned char *tmp;
> +
> +	tmp = xmalloc(sizeof(len));

sizeof(len) is not what you want.

> +
> +	ret = digest_final(d, tmp);
> +	if (ret)
> +		goto end;
> +
> +	ret = memcmp(md, tmp, len);

ret = ret ? -EINVAL : 0;

To consistently return an error code.

Sascha

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