<?php

/* THIS WILL NOT WORK WITHOUT BuddyServ V2.0 or later.
 *
 ***************************************************************************
 *   Copyright (C) 2009 by lynk   					                       *
 *   hide@address.com   						                           *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/

/* Bittorrent protocol -- taken from TBDev SOurce */

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

function benc_str($s) 
{
	return strlen($s) . ":$s";
}

function benc_int($i) 
{
	return "i" . $i . "e";
}

function benc($obj) 
{
	if (!is_array($obj) || !isset($obj["type"]) || !isset($obj["value"]))
		return;
		
	$c = $obj["value"];
	
	switch ($obj["type"]) 
	{
		case "string":
			return benc_str($c);
			
		case "integer":
			return benc_int($c);
			
		case "list":
			return benc_list($c);
			
		case "dictionary":
			return benc_dict($c);
			
		default:
			return;
	}
}

function bdec($s) 
{
	if (preg_match('/^(\d+):/', $s, $m)) 
	{
		$l = $m[1];
		$pl = strlen($l) + 1;
		$v = substr($s, $pl, $l);
		$ss = substr($s, 0, $pl + $l);
		
		if (strlen($v) != $l)
			return;
			
		return array(type => "string", value => $v, strlen => strlen($ss), string => $ss);
	}
	
	if (preg_match('/^i(\d+)e/', $s, $m)) 
	{
		$v = $m[1];
		$ss = "i" . $v . "e";
		
		if ($v === "-0")
			return;
			
		if ($v[0] == "0" && strlen($v) != 1)
			return;
			
		return array(type => "integer", value => $v, strlen => strlen($ss), string => $ss);
	}
	
	switch ($s[0]) 
	{
		case "l":
			return bdec_list($s);
			
		case "d":
			return bdec_dict($s);
			
		default:
			return;
	}
}

function bdec_list($s) 
{
	if ($s[0] != "l")
		return;
		
	$sl = strlen($s);
	$i = 1;
	$v = array();
	$ss = "l";
	
	for (;;) 
	{
		if ($i >= $sl)
			return;
			
		if ($s[$i] == "e")
			break;
			
		$ret = bdec(substr($s, $i));
		
		if (!isset($ret) || !is_array($ret))
			return;
			
		$v[] = $ret;
		$i += $ret["strlen"];
		$ss .= $ret["string"];
	}
	
	$ss .= "e";
	
	return array(type => "list", value => $v, strlen => strlen($ss), string => $ss);
}

function benc_dict($d) 
{
	$s = "d";
	$keys = array_keys($d);
	sort($keys);
	
	foreach ($keys as $k) 
	{
		$v = $d[$k];
		$s .= benc_str($k);
		$s .= benc($v);
	}
	
	$s .= "e";
	return $s;
}

function benc_list($a) 
{
	$s = "l";
	foreach ($a as $e) 
	{
		$s .= benc($e);
	}
	
	$s .= "e";
	return $s;
}

function bdec_dict($s) 
{
	if ($s[0] != "d")
		return;
		
	$sl = strlen($s);
	$i = 1;
	$v = array();
	$ss = "d";
	
	for (;;) 
	{
		if ($i >= $sl)
			return;
			
		if ($s[$i] == "e")
			break;
			
		$ret = bdec(substr($s, $i));
		
		if (!isset($ret) || !is_array($ret) || $ret["type"] != "string")
			return;
			
		$k = $ret["value"];
		$i += $ret["strlen"];
		$ss .= $ret["string"];
		
		if ($i >= $sl)
			return;
			
		$ret = bdec(substr($s, $i));
		
		if (!isset($ret) || !is_array($ret))
			return;
			
		$v[$k] = $ret;
		$i += $ret["strlen"];
		$ss .= $ret["string"];
	}
	
	$ss .= "e";
	
	return array(type => "dictionary", value => $v, strlen => strlen($ss), string => $ss);
}

function dict_check($d, $s) 
{
	if ($d["type"] != "dictionary")
		die("not a dictionary");
		
	$a = explode(":", $s);
	$dd = $d["value"];
	$ret = array();
	$t='';
	
	foreach ($a as $k) 
	{
		unset($t);
		if (preg_match('/^(.*)\((.*)\)$/', $k, $m)) 
		{
			$k = $m[1];
			$t = $m[2];
		}
		
		if (!isset($dd[$k]))
			die("dictionary is missing key(s)");
			
		if (isset($t)) 
		{
			if ($dd[$k]["type"] != $t)
				die("invalid entry in dictionary");
				
			$ret[] = $dd[$k]["value"];
		}
		else
			$ret[] = $dd[$k];
	}
	return $ret;
}