Modern password hashing for your software and your servers
BS Editor: This is an implementation of a modern password hashing Algorithm, based on the Blowfish block Cipher, provided via the crypt(3) and a reentrant interface. It is compatible with Bcrypt (version 2a) by Niels Provos and David Mazieres, as used in OpenBSD. A paper on the algorithm that explains its design decisions is available here.

The most important property of bcrypt (and thus crypt_blowfish) is that it is adaptable to future processor performance improvements, allowing you to arbitrarily increase the processing cost of checking a password while still maintaining compatibility with your older password hashes. Already now bcrypt hashes you would use are several orders of magnitude stronger than traditional Unix DES-based or FreeBSD-style MD5-based hashes.

Today, a number of other operating systems, besides OpenBSD, support bcrypt password hashes, with Niels original implementation, with this implementation (crypt_blowfish), or otherwise. These systems include recent versions of FreeBSD and NetBSD, Solaris 10, and indeed the Linux distributions that have integrated crypt_blowfish (see below for a list). Only some of these systems use bcrypt for newly set passwords by Default, though.

This code comes from John the Ripper password cracker, and is placed in the public domain to let you use this on your system, as a part of a software package, or anywhere else to improve security, ensure compatibility, or for any other purpose. Theres no license to worry about, not even a BSD-style copyright. you can free download Crypt Blowfish 1.0.2 now.