一、利用md5和字符串处理函数
$key = "This is supposed to be a secret key !!!";
function keyED($txt,$encrypt_key) {
$encrypt_key = md5($encrypt_key);
$ctr=0; $tmp = "";
for ($i=0;$i if ($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;$i if ($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 $md5 = substr($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);
print "Original text : $string
";
print "Encrypted text : $enc_text
";
print "Decrypted text : $dec_text
";
?>
二、利用md5和base64_encode及json_encode函数
// 表单验证密匙$form_api_secret = 'Wuuh7ZL8n5gdhCFS2wtm6FmU/M0=';
$options = array();
$options['expiration'] = time()+600;
$options['save-key'] = '/{year}/{mon}/{day}/upload_{filename}{.suffix}';
$policy = base64_encode(json_encode($options));
$signature = md5($policy.'&'.$form_api_secret);
?>
