OpenWrt SSH tunnel

OpenWrt SSH tunnel.md

Short how-to for creating a reverse ssh tunnel to a remote server. Useful for breaking NATted connection for example.

1. At OpenWrt:

opkg update
opkg install sshtunnel

2. At remote server: create client ssh keys

ssh-keygen -b 2048 -t rsa

Move the resulting private key to OpenWrt /root/.ssh/id_rsa, and assign chmod 600.

3. At remote server: Authorize OpenWrt client at remote server (authorized_keys)

4. At OpenWrt: Store remote host public key as known host

ssh MYUSER@REMOTEHOST
# accept yes, and press ctrl + c

5. At OpenWrt: Enable service (Start on bootup)

/etc/init.d/sshtunnel enable

6. At OpenWrt: Start service

/etc/init.d/sshtunnel start

7. At OpenWrt: configure sshtunnel

See https://wiki.openwrt.org/doc/uci/sshtunnel for more information

Example configuration

config server myremote
	option user	myuser
	option hostname	remotehost
	option IdentityFile	/root/.ssh/id_rsa
	option retrydelay	5
	option ServerAliveInterval	30
	option ServerAliveCountMax	3
	option LogLevel		DEBUG1

config tunnelR sshtunnel
	option server	myremote
	option remoteport	44423
	option remoteaddress	*
	option localport	22
	option localaddress	127.0.0.1

/etc/init.d/sshtunnel reload

For Ubuntu and other desktop Linux I created the https://github.com/yurt-page/sshtunnel