PHP实现加强版加密解密类实例

<?php class Ender{ private $enkey;//加密解密用的密钥 private $rep_char='#'; //替换加密后的base64字符串中的=,因为=在有些场合是禁止使用的， //这里可以用一个允许的字符作为替换。 //构造参数是密钥 public function __construct($key=''){ if(!$key){ $this->enkey=$key; } } //设置密钥 public function set_key($key){ $this->enkey=$key; } 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 $tmp; } //加密字符串 public function encrypt($txt,$key='') { if(!$key){ $key=$this->enkey; } 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++; } $r=base64_encode($this->keyED($tmp,$key)); $r=str_replace('=',$this->rep_char,$r); return $r; } //解密字符串 public function decrypt($txt,$key='') { $txt=str_replace($this->rep_char,'=',$txt); $txt=base64_decode($txt); if(!$key){ $key=$this->enkey; } $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; } }