goxz

Tool for creating ssh reverse tunnel on remote host to local SOCKS server. server mode is equivalent of: ssh -D <port> <user>@<address> “ssh -R <remote-address>:<remote-port>:<address>:<port> <remote-user>@<remote-host> -p <remote-port>”

client mode is equivalent of: ssh -L <remote-address>:<remote-port>:<address>:<port> <remote-user>@<remote-host> -p <remote-port>”

Forward UDP traffic over TCP:

• Open additional UDP endpoint (CLIENT_HOST_UDP:CLIENT_PORT_UDP) on client
• Open additional TCP_UDP endpoint (SERVER_HOST_TCP_UDP:SERVER_PORT_TCP_UDP should be availiable from client!) on server
• Client dials SERVER_HOST_TCP_UDP:SERVER_PORT_TCP_UDP and forward traffic from local UDP endpoint to this connection
• Server forwards traffic from TCP_UDP enpoint to specified UDP remote host (REMOTE_HOST_UDP:REMOTE_PORT_UDP) and send response over TCP back to client

Usage

goxz <server/client>

Specify following mandatory environment variables:

Server side:

ENV	Meaning
BASTION_HOST_SSH	Address of remote ssh server
BASTION_PORT_SSH	Port of remote ssh server
BASTION_SSH_USER	User to login on remote ssh server
LOCAL_HOST_TCP	TCP address on local machine to forward TCP traffic
LOCAL_PORT_TCP	TCP port on local machine to forward TCP traffic
SERVER_HOST_TCP_UDP	TCP address on local machine to forward TCP->UDP traffic (0.0.0.0 mainly)
SERVER_PORT_TCP_UDP	TCP port on local machine to forward TCP->UDP traffic
REMOTE_HOST_UDP	Remote host UDP address (DNS server, for example)
REMOTE_PORT_UDP	Remote host UDP address (DNS server, for example)

If remote host interface not configured ipv6, always listen on 0.0.0.0, no matter of REMOTE_FORWARD_HOST. Issue

Client side

ENV	Meaning
BASTION_HOST_SSH	Address of remote ssh server
BASTION_PORT_SSH	Port of remote ssh server
BASTION_SSH_USER	User to login on remote ssh server
LOCAL_HOST_TCP	TCP address on local machine to forward TCP traffic
LOCAL_PORT_TCP	TCP port on local machine to forward TCP traffic
SERVER_HOST_TCP_UDP	Server TCP address to forward TCP->UDP traffic
SERVER_PORT_TCP_UDP	Server TCP port to forward TCP->UDP traffic
CLIENT_HOST_UDP	UDP address on local machine to forward TCP->UDP traffic
CLIENT_PORT_UDP	UDP port on local machine to forward TCP->UDP traffic

Also you must specify at least one of environment variables to use for authentication on remote ssh server:

ENV	Meaning
SSH_KEY_PATH	Path to ssh private key. Use with SSH_KEY_PASSPHRASE env, if there is passhrase on key
SSH_AUTH_SOCK	SSH-Agent socket address
SSH_USER_PASSWORD	Password for user to login on remote ssh server

TODO:

• Dockerfile for build and runtime
• Monitor goroutines (possible memory leaks)
• Implement tun2socks?
• Implement UDP over TCP
• Workaround for Issue