And a couple of comments on the implementation.
Simon Josefsson <si...@josefsson.org> writes:
> + for (i = 1; i <= l; i++)
> + {
> + memset (T, 0, hLen);
> +
> + for (u = 1; u <= c; u++)
> + {
> + hmac_set_key (outer, inner, state, hash, Plen, P);
> +
> + if (u == 1)
> + {
> + tmp[0] = (i & 0xff000000) >> 24;
> + tmp[1] = (i & 0x00ff0000) >> 16;
> + tmp[2] = (i & 0x0000ff00) >> 8;
> + tmp[3] = (i & 0x000000ff) >> 0;
> +
> + hmac_update (state, hash, Slen, S);
> + hmac_update (state, hash, 4, tmp);
> + }
> + else
> + {
> + hmac_set_key (outer, inner, state, hash, Plen, P);
> + hmac_update (state, hash, hLen, U);
> + }
> +
> + hmac_digest (outer, inner, state, hash, hLen, U);
There's no need for all those hmac_set_key. You can set it once, and
compute several macs usign the same key, each with a sequence of update,
update, ..., update, digest.
If documentation or implementation doesn't agree, patches are appreciated.
> + for (k = 0; k < hLen; k++)
> + T[k] ^= U[k];
> + }
And that's what memxor is for ;-)
Regards,
/Niels
--
Niels Möller. PGP-encrypted email is preferred. Keyid C0B98E26.
Internet email is subject to wholesale government surveillance.
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