Retrieving client identity during method call

Question

Hy,
I have written an RMI application wich uses JSSE with client authentication. I would like to get the client Identity (Certificate information) each time the client perform a method call.
Can anybody help me?

Answer 1

This is rather complicated but it can be done. You need:
1. an RMIServerSocketFactory which returns
2. a wrapper ServerSocket implementation around a real ServerSocket, which delegates everything to the real ServerSocket except for the accept method, which does the delegation but then wraps the result in
3. a wrapper Socket implementation around the real Socket which delegates everything to the real Socket
except getInputStream, which does the delegation but then wraps the result in
4. a wrapper InputStream implementation around the real InputStream, which delegates everything to the real input stream but which registers the underlying Socket (the delegate, not your wrapper) in a ThreadLocal when any read method is called.
Are you with me so far? ;-)
The registered Socket will really be an SSLSocket. Now, inside your remote method implementation, you can do threadLocal.get() to get the SSLSocket associated with the current client (because you're in the same thread as in (4), because the socket is actually read for the first time in the method despatching thread. You can now do SSLSocket.getSession() and get hold of the client certificates.
Sample of (2) to get you started:
public class WrappedServerSocket extends ServerSocket
SSLServerSocket serverSocket;
public WrappedServerSocket(int port) throws IOException
{ this.serverSocket = SSLServerSocketFactory.createServerSocket(port); }
public Socket accept() throws IOException
  Socket socket = serverSocket.accept();
  return new WrappedSocket(socket);
// all other methods should delegate to serverSocket
}EJP