openssh unix dev - Feb 2018 - ChaCha20-Poly1305 auth tag failure

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.

Thanks in advance,

Will

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