Coda Hale has announced the release of his new ‘bcrypt-ruby’ gem. bcrypt-ruby brings simple OpenSSL powered password hashing to Ruby along with some useful features like hash versioning, automatic salt handling, and the ability to produce hashes that are computationally difficult to compute to reduce the risks of attacks. Read More

Skype and Google Talk are pretty clever in the way that they still work even if all of its users are behind firewalls (or NAT systems) that block incoming connections. The way they enable two-way connections is by using a ‘firewall busting’ technique. Simply, a central server does nothing but share IP addresses (and port numbers) and clients can then ‘punch’ holes through their firewalls and trick their firewalls and routers to route incoming packets back to them if they have certain source host and port numbers.

I was playing with the technique and have put together an example client that you can run on two separate hosts that have no open incoming ports but which demonstrates two way connection to an arbitrary port (6311 in this case) with UDP. Read More