<?php

function benc($str) //bencoding
{
  if (is_string($str)) { //string
    return strlen($str) . ':' . $str;
  }

  if (is_numeric($str)) { //integer
    return 'i' . $str . 'e';
  }

  if (is_array($str)) {
    $ret_str = ''; //the return string

    $k = key($str); //we check the 1st key, if the key is 0 then is a list if not a dictionary
    foreach($str as $var => $val) {
      if ($k) { //is dictionary
        $ret_str .= benc($var); //bencode the var
      }
      $ret_str .= benc($val); //we recursivly bencode the contents
    }

    if ($k) { //is dictionary
      return 'd' . $ret_str . 'e';
    }

    return 'l' . $ret_str . 'e';
  }
}

function bdec_file($f, $ms)
{
    $fp = fopen($f, "rb");
    if (!$fp)
        return;
    $e = fread($fp, $ms);
    fclose($fp);
    return bdec($e);
}

function bdec($str, &$_len = 0) //bdecoding
{
  $type = substr($str, 0, 1);

  if (is_numeric($type)) {
    $type = 's';
  }

  switch ($type) {
    case 'i': //integer
      $p = strpos($str, 'e');
      $_len = $p + 1; //lenght of bencoded data
      return intval(substr($str, 1, $p - 1));
    break;

    case 's': //string
      $p = strpos($str, ':');
      $len = substr($str, 0, $p);
      $_len = $len + $p + 1; //lenght of bencoded data
      return substr($str, $p + 1, $len);
    break;

    case 'l': //list
      $l = 1;
      $ret_array = array();
      while (substr($str, $l, 1) != 'e') {
        $ret_array[] = bdec(substr($str, $l), $len);
        $l += $len;
      }
      $_len = $l + 1; //lenght of bencoded data
      return $ret_array;
    break;

    case 'd': //dictionary
      $l = 1;
      $ret_array = array();
      while (substr($str, $l, 1) != 'e') {
        $var = bdec(substr($str, $l), $len);
        $l += $len;

        $ret_array[$var] = bdec(substr($str, $l), $len);
        $l += $len;
      }
      $_len = $l + 1; //lenght of bencoded data
      return $ret_array;
    break;
  }
}

function hex2bin($hex){
    $bin="";
    for($i=0;$i<strlen($hex);$i+=2) {
        $bin .= chr(hexdec(substr($hex,$i,2)));
    }
    return $bin;
}

//
// +----------------------------------------------------------------------+
// | Base32 Library                                                     |
// +----------------------------------------------------------------------+
// | Copyright (c) 2001 The PHP Group                                     |
// +----------------------------------------------------------------------+
// | This source file is dual-licensed. It is available under the terms   |
// | of the GNU GPL v2.0 and under the terms of the PHP license version   |
// | 2.02,  available at through the world-wide-web at                    |
// | available at through the world-wide-web at                           |
// | http://www.php.net/license/2_02.txt.                                 |
// +----------------------------------------------------------------------+
// |  Minor fixes and additional functions by Allan Hansen.               |
// |  Moodle porting work by Martin Langhoff                              |
// +----------------------------------------------------------------------+
// | base32.php - based on race.php  - RACE encode and decode strings.    |
// +----------------------------------------------------------------------+
// | Authors: Allan Hansen  <All@nHansen.dk>                              |
// |          Arjan Wekking <a.wekking@synantics.nl>                      |
// |          Martin Langhoff <martin@catalyst.net.nz>                    |
// +----------------------------------------------------------------------+
//

/**
 * Base32 encode a binary string
 *
 * @param    $inString   Binary string to base32 encode
 *
 * @return   $outString  Base32 encoded $inString
 *
 * @access   private
 *
 */

function base32_encode ($inString)
{
    $outString = "";
    $compBits = "";
    $BASE32_TABLE = array(
                          '00000' => 0x61,
                          '00001' => 0x62,
                          '00010' => 0x63,
                          '00011' => 0x64,
                          '00100' => 0x65,
                          '00101' => 0x66,
                          '00110' => 0x67,
                          '00111' => 0x68,
                          '01000' => 0x69,
                          '01001' => 0x6a,
                          '01010' => 0x6b,
                          '01011' => 0x6c,
                          '01100' => 0x6d,
                          '01101' => 0x6e,
                          '01110' => 0x6f,
                          '01111' => 0x70,
                          '10000' => 0x71,
                          '10001' => 0x72,
                          '10010' => 0x73,
                          '10011' => 0x74,
                          '10100' => 0x75,
                          '10101' => 0x76,
                          '10110' => 0x77,
                          '10111' => 0x78,
                          '11000' => 0x79,
                          '11001' => 0x7a,
                          '11010' => 0x32,
                          '11011' => 0x33,
                          '11100' => 0x34,
                          '11101' => 0x35,
                          '11110' => 0x36,
                          '11111' => 0x37,
                          );

    /* Turn the compressed string into a string that represents the bits as 0 and 1. */
    for ($i = 0; $i < strlen($inString); $i++) {
        $compBits .= str_pad(decbin(ord(substr($inString,$i,1))), 8, '0', STR_PAD_LEFT);
    }

    /* Pad the value with enough 0's to make it a multiple of 5 */
    if((strlen($compBits) % 5) != 0) {
        $compBits = str_pad($compBits, strlen($compBits)+(5-(strlen($compBits)%5)), '0', STR_PAD_RIGHT);
    }

    /* Create an array by chunking it every 5 chars */
    $fiveBitsArray = split("\n",rtrim(chunk_split($compBits, 5, "\n")));

    /* Look-up each chunk and add it to $outstring */
    foreach($fiveBitsArray as $fiveBitsString) {
        $outString .= chr($BASE32_TABLE[$fiveBitsString]);
    }

    return $outString;
}



/**
 * Base32 decode to a binary string
 *
 * @param    $inString   String to base32 decode
 *
 * @return   $outString  Base32 decoded $inString
 *
 * @access   private
 *
 */

function Base32_decode($inString) {
    /* declaration */
    $inputCheck = null;
    $deCompBits = null;

    $BASE32_TABLE = array(
                          0x61 => '00000',
                          0x62 => '00001',
                          0x63 => '00010',
                          0x64 => '00011',
                          0x65 => '00100',
                          0x66 => '00101',
                          0x67 => '00110',
                          0x68 => '00111',
                          0x69 => '01000',
                          0x6a => '01001',
                          0x6b => '01010',
                          0x6c => '01011',
                          0x6d => '01100',
                          0x6e => '01101',
                          0x6f => '01110',
                          0x70 => '01111',
                          0x71 => '10000',
                          0x72 => '10001',
                          0x73 => '10010',
                          0x74 => '10011',
                          0x75 => '10100',
                          0x76 => '10101',
                          0x77 => '10110',
                          0x78 => '10111',
                          0x79 => '11000',
                          0x7a => '11001',
                          0x32 => '11010',
                          0x33 => '11011',
                          0x34 => '11100',
                          0x35 => '11101',
                          0x36 => '11110',
                          0x37 => '11111',
                          );

    /* Step 1 */
    $inputCheck = strlen($inString) % 8;
    if(($inputCheck == 1)||($inputCheck == 3)||($inputCheck == 6)) {
        trigger_error('input to Base32Decode was a bad mod length: '.$inputCheck);
        return false;
        //return $this->raiseError('input to Base32Decode was a bad mod length: '.$inputCheck, null,
        // PEAR_ERROR_DIE, null, null, 'Net_RACE_Error', false );
    }

    /* $deCompBits is a string that represents the bits as 0 and 1.*/
    for ($i = 0; $i < strlen($inString); $i++) {
        $inChar = ord(substr($inString,$i,1));
        if(isset($BASE32_TABLE[$inChar])) {
            $deCompBits .= $BASE32_TABLE[$inChar];
        } else {
            trigger_error('input to Base32Decode had a bad character: '.$inChar);
            return false;
            //return $this->raiseError('input to Base32Decode had a bad character: '.$inChar, null,
            //    PEAR_ERROR_DIE, null, null, 'Net_RACE_Error', false );
        }
    }

    /* Step 5 */
    $padding = strlen($deCompBits) % 8;
    $paddingContent = substr($deCompBits, (strlen($deCompBits) - $padding));
    if(substr_count($paddingContent, '1')>0) {
        trigger_error('found non-zero padding in Base32Decode');
        return false;
        //return $this->raiseError('found non-zero padding in Base32Decode', null,
        //    PEAR_ERROR_DIE, null, null, 'Net_RACE_Error', false );
    }

    /* Break the decompressed string into octets for returning */
    $deArr = array();
    for($i = 0; $i < (int)(strlen($deCompBits) / 8); $i++) {
        $deArr[$i] = chr(bindec(substr($deCompBits, $i*8, 8)));
    }

    $outString = join('',$deArr);

    return $outString;
}

?>