Change password length to 32 characters

Is it possible to change the password length up to 32 for further versions?
I integrate piwik into my phpbb board. I use the salted password hash of phpbb. This is also too long so I shorten this with an md5() action to 32 characters. maybe someone else have problems with such salted password hashes it would be much more esier to integrate it in piwik with the opertunity to use md5 hashes for automatic url logins and account creatings.
I hope you understand what I mean.

Greetings Bronco

    /**
     * Returns true if the password is complex enough (at least 6 characters and max 26 characters)
     * 
     * @param string email
     * @return bool
     */
    static private function isValidPasswordString( $input )
    {        
        $l = strlen($input);
        return $l >= 6 && $l <= 32;
    }

I don’t know the background behind the 26 character limit. Perhaps Matt could weigh in.

Would it be worthwhile increasing the password column size from 32 to 40? (e.g., to accommodate hash() or sha1() password hashes in the future?)