/**
* Encrypts plaintext using Blowfish with the given key.
*
* @param string $plaintext the string to encrypt
* @param string $key the encryption key
* @param int $mode one of BLOWFISH_MODE_CBC, BLOWFISH_MODE_EBC. BLOWFISH_MODE_CBC is recommened
* @param int $padding one of BLOWFISH_PADDING_NONE, BLOWFISH_PADDING_RFC, BLOWFISH_PADDING_ZERO. BLOWFISH_PADDING_RFC is recommened
* @param int $iv the initialisation vector. Required when using CBC mode.
* @return string Returns the encrypted string. It is recommended you base64encode this for storage.
* @author Matt Harris
**/
function encrypt($plaintext, $key, $mode = Native::BLOWFISH_MODE_CBC, $padding = Native::BLOWFISH_PADDING_RFC, $iv = NULL)
{
if ($mode == Native::BLOWFISH_MODE_CBC and empty($iv)) {
throw new \Exception('CBC Mode requires an IV key');
return;
}
$ciphertext = '';
$fish = new Native($key, $mode, $padding, $iv);
$block =& $fish->blockSize;
$paded = $fish->_pad($plaintext);
$len = strlen($paded);
# encrypt in 1 byte intervals
for ($i = 0; $i < $len; $i += $block) {
if ($mode == Native::BLOWFISH_MODE_CBC) {
$chain = $i == 0 ? $fish->IV : substr($ciphertext, $i - $block, $block);
list(, $xL, $xR) = unpack('N2', substr($paded, $i, $block) ^ $chain);
} else {
list(, $xL, $xR) = unpack('N2', substr($paded, $i, $block));
}
$fish->_encipher($xL, $xR);
$ciphertext .= pack('N2', $xL, $xR);
}
unset($fish);
return $ciphertext;
}
