Allow any character in URL

I want to deliver an URL using Post in HTML/PHP with codeIgniter. So I output my URL's BASE64-Encoded in a hidden field because the URL is crawled from Googles response Page and nearly any character can be in the URL. As I'll only use my website on a local server (it's a SEO tool for my company), I want to enable any character in POST data. I already tried it with $config['permitted_uri_chars'] = '';, but that did not work. I got a 'Disallowed Key Characters' error because the Base64 string contains a =.

I'm using CodeIgniter 2

Edit:

Fivell's answer was right, thanks. So, for interested people, I took the code from Fivell's link above and wrote a small class for CodeIgniter. To do this, add a file named Base64 to your application/libraries folder and insert this code:

<?php

class Base64 {

    function url_encode($url) {
        $data = base64_encode($url开发者_C百科);
        $data = str_replace(array('+','/','='),array('-','_',''),$data);
        return $data;
    }

    function url_decode($url) {
        $data = str_replace(array('-','_'),array('+','/'),$url);
        $mod4 = strlen($data) % 4;
        if ($mod4) {
            $data .= substr('====', $mod4);
        }
        return base64_decode($data);
    }

}

?>

then, you can use it in any controller by loading the library via $this->load->library('base64); and en- or decrypt the url via $this->base64->url_encode($url) or $this->base64->url_decode($url)

http://www.php.net/manual/ru/function.base64-encode.php#63543

I think that the problem is standart base64 encoding/decoding in php which is not url safe

This is not a codeigniter issue, base64 is not safe by for POST transfer. I use this pair of function to safely encode/decode the POST data.

/**
 *
 * Safely encrypts data for POST transport
 * URL issues
 *  transforms + to spaces
 *  / are param value separators
 *  = are param value separators
 *
 *  we process the string on reverse
 * @param string $string
 */
function my_urlsafe_b64encode($string)
{
    $data = base64_encode($string);
    $data = str_replace(array('+','/','='),array('-','_','.'),$data);
    return $data;
}

/**
 *
 * The encoding string had to be specially encoded to be transported
 * over the HTTP
 *
 * The reverse function has to be executed on the client
 *
 * @param string $string
 */
private function urlsafe_b64decode($string)
{
  $data = str_replace(array('-','_','.'),array('+','/','='),$string);
  $mod4 = strlen($data) % 4;
  if ($mod4) {
    $data .= substr('====', $mod4);
  }
  return base64_decode($data);
}