Un-documented feature: SSH keys

Does anybody know how to use the SSH keys feature I just stumbled across in 2.9.14?

It’s still un-documented. Trying to import a public key it states that it only like DSA keys. But trying a DSA key I keep getting the same error message?

I created my test keys with PuTTYgen, if that matters… Will try with OpenSSH generated keys later.

Best regards,
Christian Meis