Free secure tunnel software for linux

Cubehub is a simple UDP over TCP tunnel application written in Java. It is designed to help people behind a firewall to connect through a TCP connection and play Quake and other UDP-based games.
SOCKS 4 and 5 are protocols that are supposed to allow users to send data through a firewall. However, they only work like this if the SOCKS server is on the firewall itself. Whilst TCP/IP traffic is frequently permitted through firewalls, UDP/IP (required by most online games) is often blocked. When a SOCKS 5 server relays UDP data (SOCKS 4 does not support UDP), the packets are simply relayed, there is no tunnelling involved.
This application provides a solution, tunnelling the data being relayed by a SOCKS server over one or (for better gaming performance) multiple TCP connections to help applications and games to work from behind a restrictive firewall.
Main features:
- Socks 4/5 server
- TCP and UDP tunnelling over single or multiple TCP connections
- Resilience against individual connection dropping

tcptunnel is a simple TCP tunnel written in Perl.

Also is a versatile tcp tunnel. The tcptunnel uses:
- tunnelling through a firewall or proxy
- redirecting tcp connections to other ports or machines
- debugging tcp connections in-place
- packet sniffing

The tcptunnel listens on local port < port > and when a connection is made it connects the other end of the tunnel as follows:
a) With no proxy specified, it connects the other end
to < srvport > on < srv >.
b) With a proxy, it connects to < srvport > on < proxy >.
It then directs the proxy to telnet to < srv >, and then it connects the ends of the tunnel.

Autotunnel is a small Project for setting up ipip-tunnel automatically. This can give you the possibility to have a static ip address although you get a dynamic address by your dial-in provider. You need Linux-2.2.x or 2.4.x kernel on the server and the client to run it. (with ipip support of course)


A client have to connect to an autotunnel daemon, which is setting up the ipip tunnel after the client has authentificated. Authentification is done via PAM, SSL encrypted. So you need libpam and libssl libcrypt

Change into the diectory where you unpacked the tar-ball. Have a look at the Makefile and type make and make install . If you need a new certificate - key pair type make key
The certificate and key is installed /var/autotunnel.

Secure Login provides a login extension similar to Operas Wand login.

It uses the built-in password manager, but deactivates the prefilling of login forms.
Instead, you are now able to login with one click or a keyboard shortcut (ALT+N).
Just add the Secure Login toolbar button to your toolbar, or use the provided statusbar icon.
If you hover over one of the icons, a tooltip is shown, displaying the login url and the number of available logins (users).
For more than one user or login forms on the current page a selection prompt is displayed on login.
You have the option to play sound notifications (*.wav) for found login data on the current page or when logging in.
All the options can be changed using the Secure Login settings menu or the statusbar icon context menu.

Secure Login provides you with a number of Security enhancements and helps protecting you from phishing:

Disabling the prefilling of login forms prevents malicious JavaScript code to automatically steal your login data.
This is due to the fact that no login data is inserted in form fields before the user clicks on the login button or logs in using the keyboard shortcut.
To make sure you login to the right website, the second level domain of the login url is compared to the second level domain of the current page.
If they do not match a dialog prompt is displayed before login.

SecureLogin provides you with an optional setting to protect you from all JavaScript code during login.
This can prevent cross-site scripting (XSS) attacks without having to deactivate JavaScript completely.
If you enable this option, your login data will never be inserted in any form fields nor will the login form be submitted.
Instead your credentials will be sent to the login page using internal Firefox methods.
Not all login forms will work this way, e.g. not those using JavaScript routines.
Therefore, you can add such websites to an exception list.

Ptunnel is an application that allows you to reliably tunnel TCP connections to a remote host using ICMP echo request and reply packets, commonly known as ping requests and replies. At first glance, this might seem like a rather useless thing to do, but it can actually come in your help in some cases.
Setting: Youre on the go, and stumble across an open wireless network. The network gives you an IP address, but wont let you send TCP or UDP packets out to the rest of the internet, for instance to check your mail. What to do? By chance, you discover that the network will allow you to ping any computer on the rest of the internet. With ptunnel, you can utilize this feature to check your mail, or do other things that require TCP.
Main features:
- Tunnel TCP using ICMP echo request and reply packets
- Connections are reliable (lost packets are resent as necessary)
- Handles multiple connections
- Acceptable bandwidth (150 kb/s downstream and about 50 kb/s upstream are the currently measured maximas for one tunnel, but with tweaking this can be improved further)
- Authentication, to prevent just anyone from using your proxy

HTTunnel is a universal HTTP tunnel using Apache, mod_perl and Perl.

To install this module do the following:

perl Makefile.PL
make
make test
make install

Note 1: The test suite will require the URL to an Apache::HTTunnel server to run. You will prompted for it during the installation. This server must allow tunnels to localhost:80. That Apache server must also return an HTTP 200 code for a "GET / HTTP/1.0" request.
Generally if the server has index.html file in the document root it will be ok.

SquTUN creates an AES-encrypted, SHA-1 authenticated UDP tunnel over which IP packets received from a TUN interface are encapsulated and transmitted.
It is intended to replace installations that are currently using CIPE for point-to-point VPNs. Unlike CIPE, SquTUN doesnt require a custom kernel module.
Furthermore, SquTUNs implementation and interface are much less complex, leading to greater confidence in its correctness.
Enhancements:
- This release zeroes out the remainder of the last plaintext block before sending, to avoid sending uninitialized (and possibly private) data.
- It also fixes type mismatch warnings with syslog/printf under -Wall.