On 21-07-2010, Dario Teixeira <darioteixeira@yahoo.com> wrote:
> Hi,
>
> I need a keyed hash function (HMAC) based on SHA256.  I looked at Cryptokit's
> support for HMAC, and though it has built-in support for HMAC-MD5 and HMAC-SHA1,
> it seems HMAC-SHA256 is not directly supported, despite Cryptokit implementing
> the SHA256 algorithm.
>
> While RFC 2104 seems straightforward enough and there's always the option
> of adapting Cryptokit's HMAC-SHA1 code, I wonder if someone else out there
> either a) has already done this, or b) knows of an alternative library
> implementing HMAC-SHA256.
>

If you decide to code the solution and provide the patch, I will be
happy to apply it to cryptokit (if the main author of cryptokit accepts
it, of course).

Regards,
Sylvain Le Gall