[curves] Curve448

[Michael Hamburg]

Hi Jason,

Sounds like a handy #ifdef.  I remember detection of 64-bit being harder than that, but maybe I’m misremembering.

The scalarmul routine conditions the key in the /* Scalar conditioning */ section.  You can move the conditioning code to generate_secret though if you want.

Thanks,
— Mike

> On Oct 23, 2015, at 9:33 AM, Jason A. Donenfeld <Jason at zx2c4.com> wrote:
> 
> Hey Mike,
> 
> Thanks again for putting this together. Lots of fun to play with. In
> case you're curious, I've attached here my "respin" of your
> implementation, making it suitable for kernelspace. The "#ifdef
> __SIZEOF_INT128__" might be of note for your WBITS to-do comment.
> Sending this to you in case its of interest to see an example of how
> it might be used.
> 
> Jason
> <curve448.c><curve448.h>