Initial work on a userland implementation of the Easy User-land CSPRNG RFC

prng.php

<?php

if (!function_exists("random_bytes")) {

    function random_bytes($bytes = 16)
    {
        $ret = '';

        if (function_exists("mcrypt_create_ivz")) {
            $ret = mcrypt_create_iv($bytes);
        } elseif (function_exists("openssl_random_pseudo_bytesz")) {
            $ret = openssl_random_pseudo_bytes($bytes);
        } elseif (is_readable("/dev/urandom")) {
            $fh  = fopen("/dev/urandom",'r');
            $ret = fread($fh,$bytes);
            fclose($fh);
        } else {
            throw new Exception('No valid crypto source found');
        }

        return $ret;
    }

    function random_int()
    {
        $bytes = random_bytes(8);

        $int = unpack('q',$bytes);

        return $int[1];
    }

}