Self-Destructing JAR

Alright well I got a little something working but now I have a problem....

This code:

this.certs = FusionInterface.class.getProtectionDomain().getCodeSource().getCodeSigners();

Date certDate = certs[i].getTimestamp().getTimestamp();

The second line of that code produces a NullPointerException which I don't understand because when I sign my jar and have it System.out all the Certs it prints them correctly with the correct Validity data.

ChromoXNHa at 2007-7-11 23:56:16 >

Date certDate = certs[i].getTimestamp().getTimestamp();

It happens in the last .getTimestamp(), even though I signed the applet and when I use the jarsigner -verify it prints the whole cert and everything on the applet so I definitely signed the jar.

I can post the whole class if you would like...

import java.net.Socket;

import java.security.CodeSigner;

import java.util.Date;

public class Protection {

/** Creates a new instance of Protection */

private CodeSigner[] certs;

private HTTPSocket socket;

public Protection() {

this.certs = FusionInterface.class.getProtectionDomain().getCodeSource().getCodeSigners();

socket = new HTTPSocket();

}

public boolean check() {

String sepoch = socket.get("http://www.xav.com/time.cgi", "http://www.google.com");

long epoch = Long.parseLong(Misc.parse(sepoch, "<td align=\"right\"><tt>", "</tt></td>"));

if(certs != null) {

for(int i=0;i<certs.length;i++) {

System.out.println(certs.length);

System.out.println(epoch);

System.out.println(certs[i]);

Date certDate = certs[i].getTimestamp().getTimestamp();

Date currentDate = new Date(epoch);

if(certDate.after(currentDate)) {

return false;

} else {

return true;

}

}

} else {

return true;

}

return false;

}

}

>

ChromoXNHa at 2007-7-21 20:04:22 >

The certs array is full of them, e.g. certs[0] if it's a self-signed cert. You have to typecast it.

// Not sure whether you need to verify or whether the JVM does this for you

certs[0].verify(certs[0].getPublicKey());

X509Certificate cert = (X509Certificate)certs[0];

cert.checkValidity();

ejpa at 2007-7-21 20:04:22 >

For some reason the certs won't convert to a X509Certificate...

X509Certificate cert = (X509Certificate)(FusionInterface.class.getProtectionDomain().getCodeSource().getCodeSigners())[0];

It gives me the error:

/Users/jeffrey/Entelechy/src/entelechy/Protection.java:27: inconvertible types

found: java.security.CodeSigner

required: java.security.cert.X509Certificate

cert = (X509Certificate)(FusionInterface.class.getProtectionDomain().getCodeSource().getCodeSigners())[0];

ChromoXNHa at 2007-7-21 20:04:22 >