NAME

       sidedoor - SSH connection daemon

SYNOPSIS

       sidedoor [SSH options] [user@]hostname

DESCRIPTION

       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).

OPTIONS

       See ssh(1).

SIGNALS

       SIGUSR1 resets the retry backoff, immediately retrying ssh(1) if it is not currently running.

FILES

       /etc/default/sidedoor
              Arguments to pass to sidedoor when run as a service. See ssh(1).

       /etc/sidedoor/config
              SSH client configuration file.

       /etc/sidedoor/id_rsa
              SSH private key to access the remote server.

              ssh-keygen(1) can generate this key (press y when prompted to overwrite the existing file):

                  $ sudo ssh-keygen -t rsa -N '' -f /etc/sidedoor/id_rsa

              The  corresponding  public  key  id_rsa.pub  will  need  to  be  included  in  the  remote  user's
              ~/.ssh/authorized_keys file.

       /etc/sidedoor/known_hosts
              SSH host key of the remote server.

       /etc/sidedoor/authorized_keys
              Optionally, SSH public key(s) with remote access to the local sidedoor user.

              This is a symlink to ~sidedoor/.ssh/authorized_keys.  The sidedoor-sudo package provides full root
              access to this user.

       /etc/network/if-up.d/sidedoor
              Sends SIGUSR1 to reset the retry backoff on network state changes.

SEE ALSO

       ssh(1), /usr/share/doc/sidedoor/README.md.gz

                                                   2017-01-14                                        SIDEDOOR(1)