From: Luis Parravicini <lparravi@...>
Date: 2010-10-28T12:15:03+09:00
Subject: Re: Blowfish hash

On Wed, Oct 27, 2010 at 6:50 PM, James Keener <jimktrains@gmail.com> wrote:
> With the PHP Crypt function
> [http://php.net/manual/en/function.crypt.php] I can use blowfish to
> create a hash.  Is there an equivalent function for ruby?  Preferably
> native code, as the cost parameter we use is high (more than my example
> below) and takes about 3 seconds in native code to run.
>
> Before you reply:
> 1) Block ciphers can be used as one-way hash functions and vice-verse
> 2) The salt does not need to be formatted the same, just the output of
> hashing itself (excluding the salt)
>
> So, for example:
> php> echo crypt('this is a test', '$2a$12$abcdefghijklmnopqrstuv');
> $2a$12$abcdefghijklmnopqrstuulXXDmWA0ghEUfxodWoZCvd8NILoFYg2
>
> Where:
> '12' is the 'base-2 logarithm of the iteration count for the underlying
> Blowfish-based hashing algorithmeter'
> 'abcdefghijklmnopqrstuv' is the IV (I think?) in base64 (I'm not 100%
> sure why it only uses to u but fails w/o the v)
> 'ulXXDmWA0ghEUfxodWoZCvd8NILoFYg2' is the output of the hashing
> algorithm
>
>
> php> echo crypt('\/\/007 my example rocks because it\'s amazing!!!!!!',
> '$2a$12$wellwhatdoyaknowimhere');
> $2a$12$wellwhatdoyaknowimheremd2ausy8yN9LSOrhdYQXUwYi1oQIEzi
>
> Where:
> '12' is the 'base-2 logarithm of the iteration count for the underlying
> Blowfish-based hashing algorithmeter'
> 'wellwhatdoyaknowimhere' is the IV (I think?) in base64
> 'md2ausy8yN9LSOrhdYQXUwYi1oQIEzi' is the output of the hashing algorithm

Have you seen http://philtoland.com/post/807114394/simple-blowfish-encryption-with-ruby
or this http://crypt.rubyforge.org/blowfish.html ?



-- 
Luis Parravicini
http://ktulu.com.ar/blog/