sshpoc

This demonstrates issues connecting to Go x/crypto/ssh servers using OpenSSH client.

On certain versions, the SSH client, when using an RSA identity, in the absence of server extension indicating otherwise will select handshake algorithms that the Go x/crypto/ssh server does not support.

The tracking issue for Go is golang/go#49952.

Known affected versions

• Debian Sid OpenSSH_9.0p1 Debian-1+b2, OpenSSL 3.0.5 5 Jul 2022
• Ubuntu Jammy OpenSSH_8.9p1 Ubuntu-3, OpenSSL 3.0.2 15 Mar 2022
• Fedora 36 OpenSSH_8.8p1, OpenSSL 3.0.5 5 Jul 2022
• macOS Ventura

Known unaffected versions

• macOS Monterey OpenSSH_8.6p1, LibreSSL 3.3.6

Running

You need Go 1.17 or newer to build this package.

To test your version of ssh, run: go run .