org.jgroups.protocols.KeyExchange Maven / Gradle / Ivy
package org.jgroups.protocols;
import org.jgroups.Address;
import org.jgroups.Event;
import org.jgroups.View;
import org.jgroups.stack.Protocol;
import org.jgroups.util.Tuple;
import javax.crypto.SecretKey;
import java.util.Arrays;
import java.util.List;
/**
* Base class for protocols implementing key exchange: a secret key to be used for encryption is exchanged between
* 2 parties (usually the key server and a new cluster member) securely; ie. without the possibility of
* man-in-the-middle attacks, compromising the key and (optional) perfect forward secrecy.
* This protocol has to be placed somewhere below {@link ASYM_ENCRYPT}.
* @author Bela Ban
* @since 4.0.5
*/
public abstract class KeyExchange extends Protocol {
public List requiredUpServices() {
return Arrays.asList(Event.GET_SECRET_KEY, Event.SET_SECRET_KEY);
}
/**
* Needs to fetch the secret key from a given destination (usually the key server). When received, the secret key
* (and version) needs to be installed in a protocol above using {@link #setSecretKeyAbove(Tuple)}.
* @param target The member from which to fetch the secret key
*/
public abstract void fetchSecretKeyFrom(Address target) throws Exception;
/** Returns the address of the server, e.g. server socket (if any) */
public abstract Address getServerLocation();
public Object down(Event evt) {
switch(evt.type()) {
case Event.VIEW_CHANGE:
handleView(evt.arg());
break;
}
return down_prot.down(evt);
}
protected void handleView(View view) {}
/** Fetches the secret key from a protocol above us
* @return The secret key and its version
*/
protected Tuple getSecretKeyFromAbove() {
return (Tuple)up_prot.up(new Event(Event.GET_SECRET_KEY));
}
/** Sets the secret key in a protocol above us
* @param key The secret key and its version
*/
protected void setSecretKeyAbove(Tuple key) {
up_prot.up(new Event(Event.SET_SECRET_KEY, key));
}
protected T findProtocolAbove(Class clazz) {
Protocol tmp=this;
while(tmp != null) {
Class protClass=tmp.getClass();
if(clazz.isAssignableFrom(protClass))
return (T)tmp;
tmp=tmp.getUpProtocol();
}
return null;
}
}