Re: [PATCH 2.6.26rc5] xfrm: SHA-256/384/512 HMAC support for IPsec

["Adrian-Ken Rüegsegger" <rueegsegger@swiss-it.ch>]

Martin Willi wrote:
> RFC4868 defines the use of SHA256, SHA384 and SHA512 in HMAC using 128,
> 192 and 256 bits truncation. This patch replaces the outdated SHA256
> algorithm with 96 bits truncation by the 128 bit variant and adds the
> SHA384/512 algorithms.
> 
> Signed-off-by: Martin Willi <martin@strongswan.org>
> 
> ---
> Replacing the 96 bit truncation SHA256 algorithm might be problematic,
> but it is obsolete in IPsec and I don't see a way to register two
> different truncation lengths in XFRM.

You could register a new SADB algorithm id in pfkeyv2.h and add a new
entry to the aalg_list analogous to how GCM is doing that in the aead_list.

Adrian

> --- a/net/xfrm/xfrm_algo.c 2008-06-05 14:01:01.000000000 +0200
> +++ b/net/xfrm/xfrm_algo.c 2008-06-05 14:39:31.000000000 +0200
> @@ -187,7 +187,7 @@
>  
>  	.uinfo = {
>  		.auth = {
> -			.icv_truncbits = 96,
> +			.icv_truncbits = 128,
>  			.icv_fullbits = 256,
>  		}
>  	},
> @@ -200,6 +200,42 @@
>  	}
>  },
>  {
> +	.name = "hmac(sha384)",
> +	.compat = "sha384",
> +
> +	.uinfo = {
> +		.auth = {
> +			.icv_truncbits = 192,
> +			.icv_fullbits = 384,
> +		}
> +	},
> +
> +	.desc = {
> +		.sadb_alg_id = SADB_X_AALG_SHA2_384HMAC,
> +		.sadb_alg_ivlen = 0,
> +		.sadb_alg_minbits = 384,
> +		.sadb_alg_maxbits = 384
> +	}
> +},
> +{
> +	.name = "hmac(sha512)",
> +	.compat = "sha512",
> +
> +	.uinfo = {
> +		.auth = {
> +			.icv_truncbits = 256,
> +			.icv_fullbits = 512,
> +		}
> +	},
> +
> +	.desc = {
> +		.sadb_alg_id = SADB_X_AALG_SHA2_512HMAC,
> +		.sadb_alg_ivlen = 0,
> +		.sadb_alg_minbits = 512,
> +		.sadb_alg_maxbits = 512
> +	}
> +},
> +{
>  	.name = "hmac(rmd160)",
>  	.compat = "rmd160",
>