Re: [PATCH 3/8] crypto: atmel-sha - fix error handling when setting hmac key

[<Tudor.Ambarus@microchip.com>]

On Tuesday, December 31, 2019 5:19:33 AM EET Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> HMAC keys can be of any length, and atmel_sha_hmac_key_set() can only
> fail due to -ENOMEM.  But atmel_sha_hmac_setkey() incorrectly treated
> any error as a "bad key length" error.  Fix it to correctly propagate
> the -ENOMEM error code and not set any tfm result flags.
> 
> Fixes: 81d8750b2b59 ("crypto: atmel-sha - add support to hmac(shaX)")
> Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
> Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---
>  drivers/crypto/atmel-sha.c | 7 +------
>  1 file changed, 1 insertion(+), 6 deletions(-)
> 
> diff --git a/drivers/crypto/atmel-sha.c b/drivers/crypto/atmel-sha.c
> index e8e4200c1ab3..d3bcd14201c2 100644
> --- a/drivers/crypto/atmel-sha.c
> +++ b/drivers/crypto/atmel-sha.c
> @@ -1853,12 +1853,7 @@ static int atmel_sha_hmac_setkey(struct crypto_ahash
> *tfm, const u8 *key, {
>  	struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
> 
> -	if (atmel_sha_hmac_key_set(&hmac->hkey, key, keylen)) {
> -		crypto_ahash_set_flags(tfm, 
CRYPTO_TFM_RES_BAD_KEY_LEN);
> -		return -EINVAL;
> -	}
> -
> -	return 0;
> +	return atmel_sha_hmac_key_set(&hmac->hkey, key, keylen);

The atmel_sha_hmac_key_set() is used just here, maybe it is worth getting rid 
of the function and copy its body here. As this is just a cosmetic suggestion, 
with or without this, one can add:

Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>

>  }
> 
>  static int atmel_sha_hmac_init(struct ahash_request *req)