php实现的三个常用加密解密功能函数示例

本文实例讲述了php实现的三个常用加密解密功能函数。分享给大家供大家参考，具体如下：

算法一：

//加密函数
function lock_url($txt,$key='www.jb51.net')
{
 $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";
 $nh = rand(0,64);
 $ch = $chars[$nh];
 $mdKey = md5($key.$ch);
 $mdKey = substr($mdKey,$nh％8, $nh％8+7);
 $txt = base64_encode($txt);
 $tmp = '';
 $i=0;$j=0;$k = 0;
 for ($i=0; $i<strlen($txt); $i++) {
   $k = $k == strlen($mdKey) ? 0 : $k;
   $j = ($nh+strpos($chars,$txt[$i])+ord($mdKey[$k++]))％64;
   $tmp .= $chars[$j];
 }
 return urlencode($ch.$tmp);
}
//解密函数
function unlock_url($txt,$key='www.jb51.net')
{
 $txt = urldecode($txt);
 $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";
 $ch = $txt[0];
 $nh = strpos($chars,$ch);
 $mdKey = md5($key.$ch);
 $mdKey = substr($mdKey,$nh％8, $nh％8+7);
 $txt = substr($txt,1);
 $tmp = '';
 $i=0;$j=0; $k = 0;
 for ($i=0; $i<strlen($txt); $i++) {
   $k = $k == strlen($mdKey) ? 0 : $k;
   $j = strpos($chars,$txt[$i])-$nh - ord($mdKey[$k++]);
   while ($j<0) $j+=64;
   $tmp .= $chars[$j];
 }
 return base64_decode($tmp);
}

用法：

$str="脚本之家";
$pwd = lock_url($str);
echo "加密之后：".$pwd."<br/>";
echo "解密还原：".unlock_url($pwd);

运行结果：

算法二：

<?php
function passport_encrypt($txt, $key = 'www.jb51.net')
{
 srand((double)microtime() * 1000000);
 $encrypt_key = md5(rand(0, 32000));
 $ctr = 0;
 $tmp = '';
 for($i = 0;$i < strlen($txt); $i++) {
 $ctr = $ctr == strlen($encrypt_key) ? 0 : $ctr;
 $tmp .= $encrypt_key[$ctr].($txt[$i] ^ $encrypt_key[$ctr++]);
 }
 return urlencode(base64_encode(passport_key($tmp, $key)));
}
function passport_decrypt($txt, $key = 'www.jb51.net')
{
 $txt = passport_key(base64_decode(urldecode($txt)), $key);
 $tmp = '';
 for($i = 0;$i < strlen($txt); $i++) {
 $md5 = $txt[$i];
 $tmp .= $txt[++$i] ^ $md5;
 }
 return $tmp;
}
function passport_key($txt, $encrypt_key)
{
 $encrypt_key = md5($encrypt_key);
 $ctr = 0;
 $tmp = '';
 for($i = 0; $i < strlen($txt); $i++) {
 $ctr = $ctr == strlen($encrypt_key) ? 0 : $ctr;
 $tmp .= $txt[$i] ^ $encrypt_key[$ctr++];
 }
 return $tmp;
}
?>

用法：

<?php
$txt = "1";
$key = "testkey";
$encrypt = passport_encrypt($txt,$key);
$decrypt = passport_decrypt($encrypt,$key);
echo $encrypt."<br>";
echo $decrypt."<br>";
?>

运行结果：

算法三（改进第一个加密之后的算法）

//加密函数
function lock_url($txt,$key='www.jb51.net')
{
 $txt = $txt.$key;
 $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";
 $nh = rand(0,64);
 $ch = $chars[$nh];
 $mdKey = md5($key.$ch);
 $mdKey = substr($mdKey,$nh％8, $nh％8+7);
 $txt = base64_encode($txt);
 $tmp = '';
 $i=0;$j=0;$k = 0;
 for ($i=0; $i<strlen($txt); $i++) {
   $k = $k == strlen($mdKey) ? 0 : $k;
   $j = ($nh+strpos($chars,$txt[$i])+ord($mdKey[$k++]))％64;
   $tmp .= $chars[$j];
 }
 return urlencode(base64_encode($ch.$tmp));
}
//解密函数
function unlock_url($txt,$key='www.jb51.net')
{
 $txt = base64_decode(urldecode($txt));
 $chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-=+";
 $ch = $txt[0];
 $nh = strpos($chars,$ch);
 $mdKey = md5($key.$ch);
 $mdKey = substr($mdKey,$nh％8, $nh％8+7);
 $txt = substr($txt,1);
 $tmp = '';
 $i=0;$j=0; $k = 0;
 for ($i=0; $i<strlen($txt); $i++) {
   $k = $k == strlen($mdKey) ? 0 : $k;
   $j = strpos($chars,$txt[$i])-$nh - ord($mdKey[$k++]);
   while ($j<0) $j+=64;
   $tmp .= $chars[$j];
 }
 return trim(base64_decode($tmp),$key);
}

用法：

$str="脚本之家";
$pwd = lock_url($str);
echo "加密之后：".$pwd."<br/>";
echo "解密还原：".unlock_url($pwd);

运行结果：

希望本文所述对大家PHP程序设计有所帮助。

来源：http://www.cnblogs.com/zqifa/p/php-8.html