Re: [PATCH v2 01/10] crypto: AF_ALG: add user space interface for AEAD

[Herbert Xu]

On Sun, Nov 16, 2014 at 03:23:50AM +0100, Stephan Mueller wrote:
> AEAD requires the following data in addition to normal symmetric
> ciphers:
> 
> 	* Associated authentication data of arbitrary length
> 
> 	* Authentication tag for decryption
> 
> 	* Length of authentication tag for encryption
> 
> The authentication tag data is communicated as part of the actual
> ciphertext as mandated by the kernel crypto API. Therefore we only need
> to provide a user space interface for the associated authentication data
> as well as for the authentication tag length.
> 
> This patch adds both as a setsockopt interface that is identical to the
> AF_ALG interface for setting an IV and for selecting the cipher
> operation type (encrypt or decrypt).
> 
> Signed-off-by: Stephan Mueller <smueller@xxxxxxxxxx>

I don't like the fact that we're putting arbitrary limits on
the AD, as well as the fact that the way you're doing it the
AD has to be copied.

How about simply saying that the first X bytes of the input
shall be the AD?

Cheers,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/