Getting Kerberos Service Ticket Using Waffle in Java

Question

I am working on true SSO in Java application running on Windows 10. My application already has Kerberos auth using Java's GSSAPI (but it obviously does not work on any modern Windows, especially with strict security policies and domain users), so I would like to replace current authorization system with Waffle with minimal implications to overall app design - which I think should be possible if I can get KerberosTicket instance somehow. I am struggling writing this functionality, so far I managed to request some token, but I don't really know what this token is, it does not match Kerberos ticket format. Here is my (actually more like found online code):

public byte[] getServiceTicketSSPI() {
    final String securityPackage = "Kerberos";
    final String targetName = "<disclosed>";
    IWindowsCredentialsHandle clientCredentials = null;
    WindowsSecurityContextImpl clientContext = null;
    final String currentUser = WindowsAccountImpl.getCurrentUsername();
    try {
        clientCredentials = WindowsCredentialsHandleImpl.getCurrent(securityPackage);                               
        clientCredentials.initialize();
        // initial client security context
        clientContext = new WindowsSecurityContextImpl();
        clientContext.setPrincipalName(currentUser);
        clientContext.setCredentialsHandle(clientCredentials);
        clientContext.setSecurityPackage(securityPackage);
        final Sspi.SecBufferDesc continueToken = null;
        do {
            if(debug)
                System.out.println("Using target name: " + targetName);
            clientContext.initialize(clientContext.getHandle(), continueToken, targetName);
        } while(clientContext.isContinue());

        return clientContext.getToken();
    } finally {
        if (clientContext != null)
            clientContext.dispose();
        if (clientCredentials != null)
            clientCredentials.dispose();
    }
}

To be fair I am not even sure if SSPI allows me to actually see real ticket. Am I even going in right direction with this snippet? I will be really happy so see any clues as to what should I do. It would be perfect to have KerberosTicket instance in the end.

Answer 1

Below are the steps to do Single Sign On using Waffle for standalone Java Client without using server.

Create client credentials Get service ticket using initializeSecurityContext of WindowsSecurityContextImpl. Get WindowsIdentity using accessSecurityContext of WindowsAuthProviderImpl Original link https://exceptionshub.com/getting-kerberos-service-ticket-using-waffle-in-java.html

For client-server sso, you should follow https://code.dblock.org/2010/04/08/pure-java-waffle.html The code below depicts the standalone java sso using kerberos.

import com.sun.jna.platform.win32.Sspi;
import waffle.windows.auth.IWindowsCredentialsHandle;
import waffle.windows.auth.IWindowsIdentity;
import waffle.windows.auth.IWindowsSecurityContext;
import waffle.windows.auth.impl.WindowsAccountImpl;
import waffle.windows.auth.impl.WindowsAuthProviderImpl;
import waffle.windows.auth.impl.WindowsCredentialsHandleImpl;
import waffle.windows.auth.impl.WindowsSecurityContextImpl;

public class KerberosSingleSignOn {
  public static void main() {
    try {
      System.out.println(getWindowsIdentity().getFqn());
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }

  public static IWindowsIdentity getWindowsIdentity() throws Exception {
    try {
      byte[] kerberosToken = getServiceTicketSSPI();
      WindowsAuthProviderImpl provider = new WindowsAuthProviderImpl();
      IWindowsSecurityContext securityContext = provider
        .acceptSecurityToken("client-connection", kerberosToken, "Kerberos");
      return securityContext.getIdentity();
    }
    catch (Exception e) {
      throw new Exception("Failed to process kerberos token");
    }
  }

  public static byte[] getServiceTicketSSPI() throws Exception {
    final String securityPackage = "Kerberos";
    IWindowsCredentialsHandle clientCredentials = null;
    WindowsSecurityContextImpl clientContext = null;
    final String currentUser = WindowsAccountImpl.getCurrentUsername();
    try {
      clientCredentials = WindowsCredentialsHandleImpl.getCurrent(securityPackage);
      clientCredentials.initialize();
      // initial client security context
      clientContext = new WindowsSecurityContextImpl();
      clientContext.setCredentialsHandle(clientCredentials.getHandle());
      /*OR 
       clientContext.setCredentialsHandle(clientCredentials);
       */
      clientContext.setSecurityPackage(securityPackage);
      final Sspi.SecBufferDesc continueToken = null;
      do {
        System.out.println("Using current username: " + currentUser);
        clientContext.initialize(clientContext.getHandle(), continueToken, currentUser);
      }
      while (clientContext.isContinue());

      return clientContext.getToken();
    }
    catch (Exception e) {
      throw new Exception("Failed to process kerberos token");
    }
    finally {
      if (clientContext != null)
        clientContext.dispose();
      if (clientCredentials != null)
        clientCredentials.dispose();
    }
  }
}