Here are two functions i wrote to encrypt and decrypt some text. It takes a global key to encrypt it, which means that the passwords cant be unencrypted unless the key is thrown into the function.
PHP Code:
//md5 encryption
function md5_encrypt($plain_text, $password, $iv_len = 16)
{
$plain_text .= "\x13";
$n = strlen($plain_text);
if ($n % 16) $plain_text .= str_repeat("\0", 16 - ($n % 16));
$i = 0;
$enc_text = get_rnd_iv($iv_len);
$iv = substr($password ^ $enc_text, 0, 512);
while ($i < $n) {
$block = substr($plain_text, $i, 16) ^ pack('H*', md5($iv));
$enc_text .= $block;
$iv = substr($block . $iv, 0, 512) ^ $password;
$i += 16;
}
return base64_encode($enc_text);
}
//md5 decryption
function md5_decrypt($enc_text, $password, $iv_len = 16)
{
$enc_text = base64_decode($enc_text);
$n = strlen($enc_text);
$i = $iv_len;
$plain_text = '';
$iv = substr($password ^ substr($enc_text, 0, $iv_len), 0, 512);
while ($i < $n) {
$block = substr($enc_text, $i, 16);
$plain_text .= $block ^ pack('H*', md5($iv));
$iv = substr($block . $iv, 0, 512) ^ $password;
$i += 16;
}
return preg_replace('/\\x13\\x00*$/', '', $plain_text);
}
To use it you would do somethign like this:
PHP Code:
$encrypt_key = 'globalencryption';
$string = md5_encrypt('password',$encrypt_key);