Re: Host key offered
                The line after "Host key fingerprint is:" has this format:
What goes to
Though a better way to collect the host key automatically is using
https://winscp.net/eng/docs/library_session_scanfingerprint
For an example, see
https://winscp.net/eng/docs/library_example_known_hosts
Btw, there's no "Host key offered" message in WinSCP.
        keytype bits md5 sha1
What goes to
-hostkey is either keytype bits sha1 (more secure) or keytype bits md5.
Though a better way to collect the host key automatically is using
Session.ScanFingerprint method:
https://winscp.net/eng/docs/library_session_scanfingerprint
For an example, see
https://winscp.net/eng/docs/library_example_known_hosts
Btw, there's no "Host key offered" message in WinSCP.