iox v0.4 releases: Tool for port forward & intranet proxy

Why write?

lcx and ew are awesome but can be improved.

when I first used them, I can’t remember these complicated parameters for a long time, such as tran, slave, rcsocks, sssocks… The work mode is clear, why do they design parameters like this(especially ew’s -l -d -e -f -g -h)

Besides, I think the net programming logic could be optimized.

For example, while running lcx -listen 8888 9999 command, the client must connect to :8888 first, then :9999, in iox, there’s no limit to the order in two ports. And while running lcx -slave 1.1.1.1 8888 1.1.1.1 9999 command, lcx will connect two hosts serially, but it’s more efficient to connect in concurrent, as iox does.

What’s more, iox provides a traffic encryption feature. Actually, you can use iox as a simple ShadowSocks.

And iox also provides UDP traffic forward.

Of course, because iox is written in Go, the static-link-program is a little large, raw program is 2.2MB (800KB after UPX compression)

Feature

• traffic encryption (optional)
• humanized CLI option
• logic optimization
• UDP traffic forward

Changelog v0.4

0db18f3 :

• Add TCP multiplexing in ProxyRemote(reverse proxy), only one TCP connection will be established between the victim and our forward server
• -l/–local parameter could specify which IP to listen on now

Download

Use

You can see, all params are uniform. -l/–local means listen on a local port; -r/–remote means connect to the remote host

Two-mode

fwd：

Listen on 0.0.0.0:8888 and 0.0.0.0:9999, forward traffic between 2 connections

./iox fwd -l 8888 -l 9999

for lcx:
./lcx -listen 8888 9999

Listen on 0.0.0.0:8888, forward traffic to 1.1.1.1:9999

./iox fwd -l 8888 -r 1.1.1.1:9999

for lcx:
./lcx -tran 8888 1.1.1.1 9999

Connect 1.1.1.1:8888 and 1.1.1.1:9999, forward between 2 connection

./iox fwd -r 1.1.1.1:8888 -r 1.1.1.1:9999

for lcx:
./lcx -slave 1.1.1.1 8888 1.1.1.1 9999

proxy

Start Socks5 server on 0.0.0.0:1080

./iox proxy -l 1080

for ew:
./ew -s ssocksd -l 1080

Start Socks5 server on the be-controlled host, then forward to internet VPS

VPS forward 0.0.0.0:9999 to 0.0.0.0:1080

You must use in pair because it contains a simple protocol to control connecting back

./iox proxy -r 1.1.1.1:9999
./iox proxy -l 9999 -l 1080 // notice, the two port are in order

for ew:
./ew -s rcsocks -l 1080 -e 9999
./ew -s rssocks -d 1.1.1.1 -e 9999

Then connect intranet host

# proxychains.conf
# socks5://1.1.1.1:1080

$ proxychains rdesktop 192.168.0.100:3389

enable encryption

For example, we forward the 3389 port in intranet to our VPS

// be-controller host
./iox fwd -r 192.168.0.100:3389 -r *1.1.1.1:8888 -k 656565

// our VPS
./iox fwd -l *8888 -l 33890 -k 656565

It’s easy to understand: traffic between the be-controlled host and our VPS:8888 will be encrypted, the pre-shared secret key is ‘AAA’, iox will use it to generate seed key and IV, then encrypt with AES-CTR

So, the * should be used in pairs

./iox fwd -l 1000 -r *127.0.0.1:1001 -k 000102
./iox fwd -l *1001 -r *127.0.0.1:1002 -k 000102
./iox fwd -l *1002 -r *127.0.0.1:1003 -k 000102
./iox proxy -l *1003 -k 000102

Using iox as a simple ShadowSocks

// ssserver
./iox proxy -l *9999 -k 000102

// sslocal
./iox fwd -l 1080 -r *VPS:9999 -k 000102

UDP forward

Only need to add CLI option u

./iox fwd -l 53 -r *127.0.0.1:8888 -k 000102 -u
./iox fwd -l *8888 -l *9999 -k 000102 -u
./iox fwd -r *127.0.0.1:9999 -r 8.8.8.8:53 -k 000102 -u

NOTICE: When you make a multistage connection, the Remote2Remote-UDP-mode must be started last, which is the No.3 command in the above example

UDP forwarding may have behavior that is not as you expected. Actually, on GitHub now, there are only examples of forwarding a local listener to a remote host, so I can only implement them with my understanding