Re: Java/OO techniques for modularity and re-use
Richard Maher wrote:
Since SSLSocket inherits from Socket then you can make your
t3sock of type Socket (you can assign from a subtype to a
super type).
But because SSLSocket "extends" Socket, surely I have to instantiate a
SSLSocket object somewhere don't I?
Really no need for this: -
sockFactory = (SSLSocketFactory)SSLSocketFactory.getDefault();
t3Sock = (SSLSocket)sockFactory.createSocket();
What about all the Value-Added SSL bits that the SSLSocket class must
bolt-on to a Socket?
If you need to use a SSL specific funtion you can use:
((SSLSocket)t3Sock).someSSLSOcketSpecificMethod()
You're casting t3Sock (a Socket object) as a SSLSocket object there right? I
haven't missed some abstract-class or Interface wizardry? So I've got a
vanilla Socket and cast it as a SSLSocket to call, say startHandshake(), and
it's not gonna complain about a bodgy brick-veneer job, absent any
certificate or crypto-algorithm info?
I'd find it easier to picture it the other way around where we have a
SSLSocket and our casting it as a Socket effectively masks out all the SSL
bits, but who cares? I'll just code it like you've said and see how I get
on.
Below are a little standalone console app client-server example.
I know you are in applet environment, but the idea is general.
Look for the hack section.
Arne
============================================================
import java.io.*;
import java.net.*;
import javax.net.ssl.*;
public class MultiServer {
private final static int PORT = 12345;
public static void main(String[] args) throws Exception {
ServerSocket ss;
if(args.length > 0 && args[0].equals("SSL")) {
System.out.println("SSL");
ss =
SSLServerSocketFactory.getDefault().createServerSocket(PORT);
} else {
System.out.println("Non-SSL");
ss = new ServerSocket(PORT);
}
System.out.println("Accepting connection");
Socket s = ss.accept();
System.out.println("Reading");
InputStream is = s.getInputStream();
byte[] b = new byte[10000];
int blen = 0;
int n;
while((n = is.read(b, blen, b.length - blen)) > 0) {
blen += n;
}
System.out.print("Received " + blen + " bytes from client:");
for(int i = 0; i < blen; i++) System.out.print(" " + b[i]);
System.out.println();
System.out.println("Closing");
is.close();
s.close();
ss.close();
}
}
import java.io.*;
import java.net.*;
import java.security.*;
import java.security.cert.*;
import javax.net.ssl.*;
public class MultiClient {
private final static String HOST = "localhost";
private final static int PORT = 12345;
public static void main(String[] args) throws Exception {
Socket s;
if(args.length > 0 && args[0].equals("SSL")) {
System.out.println("Connecting via SSL");
SSLContext sslctx = SSLContext.getInstance("SSL");
sslctx.init(null, new X509TrustManager[] { new
MyTrustManager() }, null);
SSLSocketFactory sf = sslctx.getSocketFactory();
s = sf.createSocket(new Socket(HOST, PORT), HOST, PORT, true);
} else {
System.out.println("Connecting plain");
s = new Socket(HOST, PORT);
}
// hack
if(s instanceof SSLSocket) {
SSLSession ses = ((SSLSocket)s).getSession();
System.out.println("Server: " + ses.getPeerPrincipal());
}
System.out.println("Sending 1 2 3 to server");
OutputStream os = s.getOutputStream();
byte[] b = { 1, 2, 3 };
os.write(b);
System.out.println("Closing");
os.close();
s.close();
}
}
class MyTrustManager implements X509TrustManager
{
public void checkClientTrusted(X509Certificate[] chain, String
authType) {
}
public void checkServerTrusted(X509Certificate[] chain, String
authType) {
}
public X509Certificate[] getAcceptedIssuers() {
return new X509Certificate[0];
}
}
C:\>java MultiServer
Non-SSL
Accepting connection
Reading
Received 3 bytes from client: 1 2 3
Closing
C:\>java -Djavax.net.ssl.keyStore=server.jks
-Djavax.net.ssl.keyStorePassword=superhemmeligt MultiServer SSL
SSL
Accepting connection
Reading
Received 3 bytes from client: 1 2 3
Closing
C:\>java MultiClient
Connecting plain
Sending 1 2 3 to server
Closing
C:\>java MultiClient SSL
Connecting via SSL
Server: CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
Sending 1 2 3 to server
Closing
Arne