HMAC has a security proof. I'm not sure CMAC does? HMAC is generally more 
practical and probably faster usually too. Would be nice to have something 
to point users at though. I think @alex had some good answers to his SO 
question about this?


On 1 May 2014 07:48:48 Ayrx <notifications@github.com> wrote:

> > @@ -3,6 +3,9 @@
> >  Message Authentication Codes
> >  ============================
> > +While cryptography supports both the CMAC and HMAC algorithms, we strongly
> > +recommend that HMAC should be used unless you have a good reason otherwise.
>
> I don't think so beyond "HMAC is more widely used". AFAIK they are both 
> unbroken.
>
> ---
> Reply to this email directly or view it on GitHub:
> https://github.com/pyca/cryptography/pull/985/files#r12180222