provide a socks proxy

this is how you provide a socks proxy, or create one. below you can find some instructions how to consume or use this proxy.

socks5 proxy ssh

ssh tunnel@server -NT -D 127.0.0.1:8080

drop it in the background:

ssh tunnel@server -NTf -D 127.0.0.1:8080

this will expose an socks proxy on your local system using port 8080. if you replace 127.0.0.1 with * everyone can connect to your machine using this proxy

socks5 proxy autossh

autossh will ensure that the ssh proxy is up all the time even when the connection drops

basic example

this will expose a socks5 proxy on port 8081.

autossh -M 0 -q -f -N user@server -D 8081 -o "ConnectTimeout 10" -o "ServerAliveCountMax 3" -o "ServerAliveInterval 60" -o "ExitOnForwardFailure=yes"

more advanced example with reverse tunnel

this will expose a socks5 proxy on port 8081, bound to the local ip address of the device (192.168.178.21) so it can be used by other systems on the network. this one is running on a raspberry pi, available to all other devices at home.

it also exposes a reverse tunnel on the machine it’s connecting to using port 2222, meaning, when I’m on the host machine (server) I can ssh into my raspberry pi like so: ssh -p2222 pi@localhost to end up on my pi. this is great if you’re behind some stupid carrier grade nat.

autossh -M 0 -q -f -N -o "ConnectTimeout 10" -o "ServerAliveCountMax 3" -o "ServerAliveInterval 60" -o "Port=22022" -o "ExitOnForwardFailure=yes" -R2222:localhost:22 -D192.168.178.21:8081 tunnel@server

use a socks proxy

system wide

usually there’s a system setting on your machine to use a socks proxy, just enter the ip address (either 127.0.0.1 or the one of your proxy device like the raspberry pi 192.168.178.21) followed by the port (8081) and you’re good to go.

browsers

some browsers use the system settings, some don’t. firefox doesn’t, so you need to go into the firefox settings to set a socks proxy. for (google) chrome there’s an extension like Proxy SwitchyOmega to have a proxy set just for the chrome browser

terminal / shell

if you want to use the proxy in a terminal with other tools like curl, you need to expose / set the environment variables http_proxy and https_proxy

export http_proxy="socks5://192.168.178.21:8081"
export https_proxy=$http_proxy

then you can do things like: curl icanhazip.com and it’ll use the proxy. make sure that this is not permanent, if you need this permanent it needs to be placed into your .zshrc or .bashrc file

there are also tools like tsocks which I haven’t used yet or sshuttle

there’s also other software out there which could help with a somewhat syste-mwide proxy or a poor mans vpn:

sshuttle
tsocks
proxychains
proxychains-ng

alpine