[PATCH] COMP128v23 improvements

[Peter Stuge]

Hi,

☎ wrote:
> I've got rid of unnecessary cycle and to made difference between v2 and
> v3 more visible: v2 is basically just v3 with last bits of Kc zeroed.
> Also - small readability improvements.

More on this below.


> Also I've added test suite with test vectors from original python implementation.

Cool!

> +++ b/include/osmocom/gsm/comp128v23.h
> @@ -13,11 +13,11 @@
>   * Performs the COMP128 version 2 and 3 algorithm (used as A3/A8)
>   * ki    : uint8_t [16]
>   * srand : uint8_t [16]
> - * version : uint8_t (2 or 3)
>   * sres  : uint8_t [4]
>   * kc    : uint8_t [8]
>   * returns 1 if not version 2 or 3 specified
>   */
> -int comp128v23(const uint8_t *ki, const uint8_t *rand, uint8_t version, uint8_t *sres, uint8_t *kc);

Since this is a public API I don't know if the old function can be removed.


> +int comp128v3(const uint8_t *ki, const uint8_t *rand, uint8_t *sres, uint8_t *kc);
> +int comp128v3(const uint8_t *ki, const uint8_t *rand, uint8_t *sres, uint8_t *kc);

Copypaste error here. I think it's nice to add two new functions, but
probably the old one needs to stay there.


> +++ b/src/gsm/auth_comp128v23.c
> @@ -31,7 +31,7 @@ static int c128v2_gen_vec(struct osmo_auth_vector *vec,
>  			  struct osmo_sub_auth_data *aud,
>  			  const uint8_t *_rand)
>  {
> -	comp128v23(aud->u.gsm.ki, _rand, 2, vec->sres, vec->kc);
> +	comp128v2(aud->u.gsm.ki, _rand, vec->sres, vec->kc);
>  	vec->auth_types = OSMO_AUTH_TYPE_GSM;
>  
>  	return 0;

I like this change, thanks to the two new functions.


//Peter