/*****************************************************
* COPYRIGHT NOTICE
* Copyright (c) 2011, 艾克视图
* All rights reserved
*
* @file XHaffmanSec.class.php
* @brief X哈弗曼码加密类
* 本PHP类实现了以哈弗曼编码形式对文本进行加密及解密。
* 使用方法
* $xhaff = new XHaffman();
* $text_1 = $xhaf-->Encode("明文", "密钥"); ///< 加密
* $text_2 = $xhaff->Decode("密文", "密钥"); ///< 解密
*
* @version 1.0
* @author XadillaX
* @date 2011-1-13
* @web http://www.xcoder.in
*
* 修订说明：最初版本
*****************************************************/
define("COPY_CONSTRUCT", "-65535");
define("NO_NODE", "-65535");
define("NO_POS", "-65535");
class HTNode {
var $data = 0;
var $lc = NO_NODE, $rc = NO_NODE;
var $w = 0;
var $pos = 0;
public function __construct($_d, $_w, $_pos = NO_POS, $_l = NO_NODE, $_r = NO_NODE) {
$this->data = $_d;
$this->w = $_w;
$this->lc = $_l;
$this->rc = $_r;
$this->pos = $_pos;
}
};
function HTNodeCmp(HTNode $a, HTNode $b) {
return $a->w < $b->w;
}
class XHaffman {
/** 权值从Lolita小说中抽样取出 */
var $ch = array(
10, 32, 33, 37, 40, 41, 44, 45, 46, 48,
49, 50, 51, 52, 53, 54, 55, 56, 57, 58,
59, 63, 65, 66, 67, 68, 69, 70, 71, 72,
73, 74, 75, 76, 77, 78, 79, 80, 81, 82,
83, 84, 85, 86, 87, 88, 89, 90, 91, 93,
97, 98, 99, 100, 101, 102, 103, 104, 105, 106,
107, 108, 109, 110, 111, 112, 113, 114, 115, 116,
117, 118, 119, 120, 121, 122, 123, 161, 164, 166,
168, 170, 173, 174, 175, 176, 177, 180, 186,
95
);
var $fnum = array(
2970, 99537, 265, 1, 496, 494, 9032, 1185, 5064, 108,
180, 132, 99, 105, 82, 64, 62, 77, 126, 296,
556, 548, 818, 443, 543, 435, 225, 271, 260, 797,
3487, 158, 50, 1053, 589, 498, 332, 316, 61, 276,
724, 855, 54, 293, 543, 11, 185, 11, 25, 26,
42416, 7856, 12699, 23670, 61127, 10229, 10651, 27912, 32809, 510,
4475, 23812, 13993, 34096, 38387, 9619, 500, 30592, 30504, 42377,
14571, 4790, 11114, 769, 10394, 611, 1, 4397, 12, 71,
117, 1234, 81, 5, 852, 1116, 1109, 1, 3,
5000
);
var $root = NULL;
var $nodes = array();
var $_nodes = array();
var $decode_arr = array();
var $encode_arr = array();
/**
* 创建哈弗曼树
*/
private function __CreateHT() {
$len = count($this->nodes);
$_len = 0;
while($len > 1) {
/** 对结点排序并取出权值最小的两个节点 */
usort($this->nodes, "HTNodeCmp");
$lmin = $this->nodes[$len - 1];
$rmin = $this->nodes[$len - 2];
/** 若此节点未记录，则在_nodes中记录 */
if($lmin->pos == NO_POS) {
$lmin->pos = $_len;
$this->_nodes[$_len] = $lmin;
$_len++;
}
if($rmin->pos == NO_POS) {
$rmin->pos = $_len;
$this->_nodes[$_len] = $rmin;
$_len++;
}
/** 合并两个节点，并将新节点放入数组 */
$this->_nodes[$_len] = new HTNode(0, $lmin->w + $rmin->w, $_len, $lmin->pos, $rmin->pos);
$_len++;
unset($this->nodes[$len - 1]);
unset($this->nodes[$len - 2]);
$len--;
$this->nodes[$len - 1] = $this->_nodes[$_len - 1];
}
/** 根节点 */
$this->root = $this->nodes[0];
}
/**
* 创建哈弗曼编码
*/
private function __CreateHTCode($pos, $num) {
if($pos == NO_POS) return;
$node = $this->_nodes[$pos];
if($node->data != 0) {
$this->decode_arr[strval($num)] = $node->data;
$this->encode_arr[$node->data] = $num;
}
$this->__CreateHTCode($node->lc, $num << 1);
$this->__CreateHTCode($node->rc, ($num << 1) + 1);
}
public function __construct() {
/** 构造函数 */
$len = count($this->fnum);
/** 照权值设置结点 */
for($i = 0; $i < $len; $i++)
$this->nodes[$i] = new HTNode($this->ch[$i], (int)($this->fnum[$i]));
/** 未设置的编码以4000为权值 */
for($i = 1; $i < 256; $i++)
if(!in_array($i, $this->ch))
$this->nodes[$len++] = new HTNode($i, 4000);
/** 创建Haffman编码 */
$this->__CreateHT();
$this->__CreateHTCode($this->root->pos, 1);
}
/**
* 解密函数
* @param $str
* @param $key
* @return 明文
* 将密文$str以密钥$key解密，返回明文
*/
public function Decode($str, $key) {
$comlen = strlen($str);
$klen = strlen($key);
$decode = "";
$decode_arr = array();
for($i = 0; $i < $comlen; $i++)
$str[$i] = chr(ord($str[$i]) ^ ord($key[$i % $klen]));
$str = gzuncompress($str);
$decode_arr = explode("#", $str);
$len = count($decode_arr);
for($i = 0; $i < $len; $i++) {
$type = $decode_arr[$i][0];
$haff = intval(substr($decode_arr[$i], 1, strlen($decode_arr[$i]) - 1));
$haff ^= ord($key[$i % $klen]);
if(array_key_exists(strval($haff), $this->decode_arr))
$ch = $this->decode_arr[strval($haff)];
else $ch = $haff;
//echo $ch . " ";
$decode .= chr($ch);
}
return $decode;
}
/**
* 加密函数
* @param $str
* @param $key
* @return 密文
* 将$str以$key为密钥进行加密，返回加密串
*/
public function Encode($str, $key) {
$len = strlen($str);
$klen = strlen($key);
$encode_arr = array();
for($i = 0; $i < $len; $i++) {
$asc = ord($str[$i]);
if(array_key_exists($asc, $this->encode_arr)) {
$haff = $this->encode_arr[$asc];
$haff ^= ord($key[$i % $klen]);
$encode_arr[$i] = "1" . $haff;
}
else {
$haff = $asc;
$haff ^= ord($key[$i % klen]);
$encode_arr[$i] = "2" . $haff;
}
}
$text = implode("#", $encode_arr);
$text = gzcompress($text, 9);
$comlen = strlen($text);
for($i = 0; $i < $comlen; $i++)
$text[$i] = chr(ord($text[$i]) ^ ord($key[$i % $klen]));
return $text;
}
}
//$h = new XHaffman(); //$text = $h->Encode("的发生加拉克四谛法加拉克", "12345");
//
//echo $h->Decode($text, "12345");
?>
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