chacha20+poly1305 authenticated encryption

[Damien Miller]

On Sun, 17 Nov 2013, Christian Weisgerber wrote:

> Christian Weisgerber <naddy at mips.inka.de> wrote:
> 
> > There must be a bug somewhere else, but I don't see it.
> 
> Found it.  The authentication tag size was wrong in the ciphers
> table.  With the changes below, this now passes the relevant
> regression tests on alpha, amd64, and sparc64; and I verified that
> these architectures all interoperate successfully.

Thanks, good catches.

-d