/**
* Returns the result of applying XOR on the specified attribute's address. The method may be used
* for both encoding and decoding XorMappedAddresses.
*
* @param address the address on which XOR should be applied
* @param transactionID the transaction id to use for the XOR
* @return the XOR-ed address.
*/
public static TransportAddress applyXor(TransportAddress address, byte[] transactionID) {
byte[] addressBytes = address.getAddressBytes();
char port = (char) address.getPort();
char portModifier =
(char) ((transactionID[0] << 8 & 0x0000FF00) | (transactionID[1] & 0x000000FF));
port ^= portModifier;
for (int i = 0; i < addressBytes.length; i++) addressBytes[i] ^= transactionID[i];
TransportAddress xoredAdd;
try {
xoredAdd = new TransportAddress(addressBytes, port, Transport.UDP);
} catch (UnknownHostException e) {
// shouldn't happen so just throw an illegal arg
throw new IllegalArgumentException(e);
}
return xoredAdd;
}
