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/* $Id$ */
package org.noreply.fancydress.type3;
import org.noreply.fancydress.misc.Util;
import org.noreply.fancydress.type3.routing.*;
import org.noreply.fancydress.crypto.*;
import org.noreply.fancydress.status.*;
import java.util.*;
public class Packet {
private byte[] packet;
private Routing thisRoute;
public Packet(
Path path,
RoutingDestination address,
Payload payload)
throws Mix3BadArgumentsChainTooLongException
{
ForwardLeg leg2 = new ForwardLeg(path.getSecondHalf(), address);
if (!(leg2.getRoute() instanceof RoutingForward))
throw new Error("Routing Type of second leg is not a forward type.");
ForwardLeg leg1 = new ForwardLeg(path.getFirstHalf(), ((RoutingForward)leg2.getRoute()).asSwap());
makePacket(leg1, leg2, payload);
}
public Packet(
HalfPath path,
SURB surb,
Payload payload)
throws Mix3BadArgumentsChainTooLongException
{
ForwardLeg leg1 = new ForwardLeg(path, surb.getRoute());
makePacket(leg1, surb, payload);
}
public static boolean isPacketVersionSupported(String s) {
return s.equals(SingleLeg.MAJOR_VERSION + "." + SingleLeg.MINOR_VERSION);
}
private void makePacket(ForwardLeg leg1, SingleLeg leg2, Payload payload) {
byte p[] = payload.asOctets();
byte h1[] = leg1.asOctets();
byte h2[] = leg2.asOctets();
// Phase 1
if (leg2 instanceof SURB) {
byte[] k = ((SURB) leg2).getEncryptionKey();
p = CryptoPrimitives.sprpDecrypt(k, "PAYLOAD ENCRYPT", p);
} else {
byte[][] sk = ((ForwardLeg) leg2).getSharedKeys();
for (int i=sk.length-1; i>=0; i--)
p = CryptoPrimitives.sprpEncrypt(sk[i], "PAYLOAD ENCRYPT", p);
}
// Phase 2
h2 = CryptoPrimitives.sprpEncrypt(CryptoPrimitives.hash(p), "HIDE HEADER", h2);
p = CryptoPrimitives.sprpEncrypt(CryptoPrimitives.hash(h2), "HIDE PAYLOAD", p);
byte[][] sk = leg1.getSharedKeys();
for (int i=sk.length-1; i>=0; i--) {
h2 = CryptoPrimitives.sprpEncrypt(sk[i], "HEADER ENCRYPT", h2);
p = CryptoPrimitives.sprpEncrypt(sk[i], "PAYLOAD ENCRYPT", p);
}
packet = Util.concat(Util.concat(h1,h2),p);
thisRoute = leg1.getRoute();
}
public Routing getRoute() {
return thisRoute;
}
public byte[] asOctets() {
return packet;
}
}
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