<?php
class Crypt{
// 本文來源：龍哥博客
protected $key = “”; //公鑰
private function keyED($txt,$encrypt_key)
{
$encrypt_key = md5($encrypt_key);
$ctr=0;
$tmp = “”;
for ($i=0;$i<strlen($txt);$i++)
{
if ($ctr==strlen($encrypt_key)){
$ctr=0;
}
$tmp.= substr($txt,$i,1) ^ substr($encrypt_key,$ctr,1);
$ctr++;
}
return $tmp;
}
public function encrypt($txt,$key=”")
{
if(empty($key)){
$key=$this->key;
}
srand((double)microtime()*1000000);
$encrypt_key = md5(rand(0,32000));
$ctr=0;
$tmp = “”;
for ($i=0;$i<strlen($txt);$i++)
{
if ($ctr==strlen($encrypt_key)){
$ctr=0;
}
$tmp.= substr($encrypt_key,$ctr,1) .
(substr($txt,$i,1) ^ substr($encrypt_key,$ctr,1));
$ctr++;
}
return $this->keyED($tmp,$key);
}
public function decrypt($txt,$key=”")
{
if(empty($key)){
$key=$this->key;
}
$txt = $this->keyED($txt,$key);
$tmp = “”;
for ($i=0;$i<strlen($txt);$i++)
{
$md5 = substr($txt,$i,1);
$i++;
$tmp.= (substr($txt,$i,1) ^ $md5);
}
return $tmp;
}
public function setKey($key)
{
if(empty($key)){
return null;
}
$this->key=$key;
}
public function getKey()
{
return $this->key;
}
// Downloads By http://www.bkjia.com
}
$string = “http://www.52blogger.com”;
$crypt= new Crypt();
$crypt->setKey(“http://www.52blogger.com”);
$enc_text = $crypt->encrypt($string,$crypt->getKey());
$dec_text = $crypt->decrypt($enc_text,$crypt->getKey());
echo “加密前 : $string <br/>\n”;
echo “加密後 : $enc_text <br/>\n”;
echo “解密後 : $dec_text \n”;
?>
執行結果:
加密前 : http://www.52blogger.com
加密後 : hSzQ’Z* kP~y(WpVs=6Q3gZbR5QkhtZ(f=Zm
解密後 : http://www.52blogger.com
注意的是：每次加密後的字符串都不一樣,另外還需要公鑰才能解密,如果公鑰不對,解密的結果與明文是不一致的.可惜的是,此方法貌似不支持中文~
