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)