php自定义加密函数、解密的例子

“/*加密*/

function addcoder($str)

    {

        $yuan = 'abA!c1dB#ef2@Cg$h%iD_3jkl^E:m}4n.o{&F*p)5q(G-r[sH]6tuIv7w+Jxy8z9K0';

        $jia = 'zAy%0Bx+1C$wDv^Eu2-t3(F{sr&G4q_pH5*on6I)m:l7.Jk]j8K}ih@gf9#ed!cb[a';

       if ( strlen($str) == 0) return false;

for($i = 0;$i

        {

            for($j = 0;$j

{

if($str[$i]==$yuan[$j])

                    {

$results.= $jia[$j];

break;

}

            }

        }

       return $results;

    }

/*解密*/

function removecoder($str)

{

        $yuan = 'abA!c1dB#ef2@Cg$h%iD_3jkl^E:m}4n.o{&F*p)5q(G-r[sH]6tuIv7w+Jxy8z9K0';

        $jia = 'zAy%0Bx+1C$wDv^Eu2-t3(F{sr&G4q_pH5*on6I)m:l7.Jk]j8K}ih@gf9#ed!cb[a';

       If (strlen($str)==0) return false;

  for($i = 0;$i< strlen($str);$i++)

{

 for($j = 0;$j

  {

  if($str[$i]==$jia[$j]) 

{

$results .= $yuan[$j];

break;

}

  }

}

       return $results;

    }

$str = "www.111com.net";
echo "加密前：".$str."
";
$str1= addcoder($str);
echo "加密后：".$str1."
";
$str2= removecoder($str1);
echo "解密后：".$str2."
";

//www.111com.net
function passport_encrypt($txt, $key) {
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 base64_encode(passport_key($tmp, $key));
}
function passport_decrypt($txt, $key) {
$txt = passport_key(base64_decode($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;
}
?>