加密解密类

 <?php

/**

 *  加密 解密类

 *  加密，可逆

 *  可接受任何字符

 *  安全度非常高

 * 自定义 字符串 和 key

 */

/**

 * 使用示例：

 *$s = new  myCrypt($text);

 *加密

 *echo $string = $s->encrypt();

 *echo "<br>";

 *  解密

 *echo $s->decrypt($string);

 *

 */

class myCrypt

{

/**

* 要加密的字符串

*

* @var string

*/

var $sTxt;

/**

* key 

*

* @var string

*/

var $sKey;

/**

* 定义的加密串码

*

* @var string

*/

var $sChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_."; 

 

/**

* 加密 解密 的key

*

* @var string

*/

var $iKey ="-x6g6ZWm2G9g_vr0Bo.pOq3kRIxsZ6rm3330os";

/**

* 构造函数   

*

* @param string $sTxt

* @param string $sKey

*/

function __construct($sKey = 'anihc ctI')

{

if(empty($sKey))

{

$this->sKey = 'anihc ctI';

}

else

{

$this->sKey = $sKey;

}

}

/**

 * 加密函数

 *

 * @return string

  */

function encrypt($sTxt)

{

$this->sTxt = $sTxt;

$nh1 = rand(0,64);

$nh2 = rand(0,64);

$nh3 = rand(0,64);

$ch1 = $this->sChars{$nh1};

$ch2 = $this->sChars{$nh2};

$ch3 = $this->sChars{$nh3};

$nhnum = $nh1 + $nh2 + $nh3;

$knum = 0;$i = 0;

while(isset($this->sKey{$i}))

{

$knum += ord($this->sKey{$i++});

$mdKey = substr(md5(md5(md5($this->sKey.$ch1).$ch2.$this->iKey).$ch3),$nhnum%8,$knum%8 + 16);

}

$this->sTxt = base64_encode($this->sTxt);

$this->sTxt = str_replace(array('+','/','='),array('-','_','.'),$this->sTxt);

$tmp = '';

$j=0;$k = 0;

$tlen = strlen($this->sTxt);

$klen = strlen($mdKey);

for ($i=0; $i<$tlen; $i++)

{

$k = $k == $klen ? 0 : $k;

$j = ($nhnum+strpos($this->sChars,$this->sTxt{$i})+ord($mdKey{$k++}))%64;

$tmp .= $this->sChars{$j};

}

$tmplen = strlen($tmp);

$tmp = substr_replace($tmp,$ch3,$nh2 % ++$tmplen,0);

$tmp = substr_replace($tmp,$ch2,$nh1 % ++$tmplen,0);

$tmp = substr_replace($tmp,$ch1,$knum % ++$tmplen,0);

return $tmp;

}

 

/**

    * 解密函数

    *

    * @param string $sString  需要解密的字符串

    * @return string

    */

function decrypt($sString)

{

$knum = 0;

$i = 0;

$tlen = strlen($sString);

while(isset($this->sKey{$i}))

{

$knum +=ord($this->sKey{$i++});

}

$ch1 = $sString{$knum % $tlen};

$nh1 = strpos($this->sChars,$ch1);

$sString = substr_replace($sString,'',$knum % $tlen--,1);

$ch2 = $sString{$nh1 % $tlen};

$nh2 = strpos($this->sChars,$ch2);

$sString = substr_replace($sString,'',$nh1 % $tlen--,1);

$ch3 = $sString{$nh2 % $tlen};

$nh3 = strpos($this->sChars,$ch3);

$sString = substr_replace($sString,'',$nh2 % $tlen--,1);

$nhnum = $nh1 + $nh2 + $nh3;

$mdKey = substr(md5(md5(md5($this->sKey.$ch1).$ch2.$this->iKey).$ch3),$nhnum % 8,$knum % 8 + 16);

$tmp = '';

$j=0; $k = 0;

$tlen = strlen($sString);

$klen = strlen($mdKey);

for ($i=0; $i<$tlen; $i++)

{

$k = $k == $klen ? 0 : $k;

$j = strpos($this->sChars,$sString{$i})-$nhnum - ord($mdKey{$k++});

while ($j<0) $j+=64;

$tmp .= $this->sChars{$j};

}

$tmp = str_replace(array('-','_','.'),array('+','/','='),$tmp);

return trim(base64_decode($tmp));

}

}

?>