En/docs/api/socks

SOCKS

Copying from Wikipedia:

SOCKS is an Internet protocol that exchanges network packets between a client and server through a proxy server. SOCKS5 optionally provides authentication so only authorized users may access a server. Practically, a SOCKS server proxies TCP connections to an arbitrary IP address, and provides a means for UDP packets to be forwarded.

SOCKS and SOCKS proxies

The SOCKS proxy is working as of release 0.7.1. SOCKS 4/4a/5 are supported. Enable SOCKS by creating a SOCKS client tunnel in i2ptunnel. Both shared-clients and non-shared are supported. There is no SOCKS outproxy so it is of limited use.

As it says on the FAQ:

Many applications leak sensitive
information that could identify you on the Internet. I2P only filters
connection data, but if the program you intend to run sends this
information as content, I2P has no way to protect your anonymity.  For
example, some mail applications will send the IP address of the machine
they are running on to a mail server. There is no way for I2P to filter
this, thus using I2P to 'socksify' existing applications is possible, but
extremely dangerous.

And quoting from a 2005 email:

... there is a reason why human and
others have both built and abandoned the SOCKS proxies.  Forwarding
arbitrary traffic is just plain unsafe, and it behooves us as
developers of anonymity and security software to have the safety of
our end users foremost in our minds.

Hoping that we can simply strap an arbitrary client on top of I2P without auditing both its behavior and its exposed protocols for security and anonymity is naive. Pretty much *every* application and protocol violates anonymity, unless it was designed for it specifically, and even then, most of those do too. That's the reality. End users are better served with systems designed for anonymity and security. Modifying existing systems to work in anonymous environments is no small feat, orders of magnitude more work that simply using the existing I2P APIs.

The SOCKS proxy supports standard addressbook names, but not Base64 destinations. Base32 hashes should work as of release 0.7. It supports outgoing connections only, i.e. an I2PTunnel Client. UDP support is stubbed out but not working yet. Outproxy selection by port number is stubbed out.

See Also

• The notes for meetings #81 and #82 in March 2004.
• Onioncat
• search for "socks" on zzz.i2p

If You Do Get Something Working

Please let us know. And please provide substantial warnings about the risks of socks proxies.