Read host keys from environment variables

[Theo de Raadt]

> I'm just looking at alternative ways to secure the host-keys.

I think you are very wrong here.  Maybe it feels more secure in your specific
synthetic environment.

But your proposal is going to be accidentally used by others in
environments where host keys become significantly LESS SECURED than
filesystem access, which is why I (and others) do not believe this
proposed mechanism should exist.

This has been said by others in different ways, and I now think you are
not engaging in good faith.