Binary package “sidedoor” in ubuntu eoan

SSH connection daemon

 sidedoor maintains an SSH connection or tunnel
 with a shell script daemon.
 The primary use case is maintaining a remote port forward
 to the local SSH server (or another port). Thus, the local
 device can be accessed without using incoming connections
 that may be blocked by a NAT or firewall or otherwise
 impractical with mobile devices.
 SSH clients can connect to the device via the reverse SSH proxy
 that sidedoor tunnels to. This proxy server can be untrusted
 and run by a third party or cloud service.
 sidedoor enables SSH keepalives and retries SSH with
 exponential backoff. In order to reconnect as soon as possible,
 it resets the backoff when a network interface is brought up
 (or changed).
 Refer to the sidedoor man page to configure and set SSH keys.