<?php
$key = "This is supposed to be a secret key !!!";
function keyED($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 $tmp;
}
function encrypt($txt,$key)
{
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));
$ctr++;
}
return keyED($tmp,$key);
}
function decrypt($txt,$key)
{
$txt = keyED($txt,$key);
$tmp = "";
for ($i=0;$i<strlen($txt);$i++)
{
$md5 = substr($txt,$i,1);
$i++;
$tmp.= (substr($txt,$i,1) ^ $md5);
}
return $tmp;
}
$string = "Hello World !!!";
// encrypt $string, and store it in $enc_text
$enc_text = encrypt($string,$key);
// decrypt the encrypted text $enc_text, and store it in $dec_text
$dec_text = decrypt($enc_text,$key);
//加密
function str2hex($s)
{
$r = "";
$hexes = array ("0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f");
for ($i=0; $i<strlen($s); $i++)
$r .= ($hexes [(ord($s{$i}) >> 4)] . $hexes [(ord($s{$i}) & 0xf)]);
return $r;
}
//解密
function hex2str($s)
{
$r = "";
for ( $i = 0; $i<strlen($s); $i += 2)
{
$x1 = ord($s{$i});
$x1 = ($x1>=48 && $x1<58) ? $x1-48 : $x1-97+10;
$x2 = ord($s{$i+1});
$x2 = ($x2>=48 && $x2<58) ? $x2-48 : $x2-97+10;
$r .= chr((($x1 << 4) & 0xf0) | ($x2 & 0x0f));
}
return $r;
}
echo str2hex("山东");
echo "<br>";
echo hex2str("c9bdb6ab");
?>
