ChaCha20-Poly1305 auth tag failure

[Damien Miller]

On Mon, 19 Feb 2018, Will Cosgrove wrote:

> Hi All,
>
> I’m implementing ChaCha20-Poly1305 in an OS ssh client library libssh2
>(https://github.com/libssh2/libssh2). I’m using the ChaCha related
>files from OpenSSH with very minimal modifications. I have it working
>connecting to sshd, but every ~2 million packets I'll get a random auth
>tag failure when downloading files (the last 4 bytes don’t match).
>
> I know this borderline off-topic, but if I could bend the ear of the
>implementer of the ChaCha20 support off-list that’d be great. I’d
>really like to get this working 100% but I’m running out of ideas.

That would be me - go for it.

-d