php 加密解密函数封装

算法一：　

//加密函数
function lock_url($txt,$key='yang')
{
  $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='yang')
{
  $txt = urldecode($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);
}

算法二：

function passport_encrypt($txt, $key = 'yang')
{
  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 = 'yang')
{
  $txt = passport_key(base64_decode(urldecode($txt)), $key);
  $tmp = '';
  for($i = 0;$i < strlen($txt); $i++) {
  $md5 = $txt[$i];
  $tmp .= $txt[++$i] ^ $md5;
  }
  return $tmp;
} 

算法三：

//加密函数
function lock_url($txt,$key='yang')
{
  $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='yang')
{
  $txt = base64_decode(urldecode($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);
}