30
votes

I'd like to have my desktop Java application to have single sign on related to Active Directory users. In two steps, I'd like to:

  1. Be sure that the particular user has logged in to Windows with some user entry.
  2. Check out some setup information for that user from the Active Directory

With Java: Programatic Way to Determine Current Windows User I can get the name of the current Windows user but can I rely to that? I think the

System.getProperty("user.name")

won't be secure enough? ("user.name" seems to be got from environment variables, so I can't rely on that, I think?)

Question Authenticating against Active Directory with Java on Linux provides me the authentication for given name+pass but I'd like to authenticate based on the Windows logon?

For the Active Directory access, LDAP would probably be the choice?

6

6 Answers

14
votes

It is not supported. Java 6 has improvements, but not enough yet.

Java has its own GSS stack. The problem is for single sign-on, you need to get the Kerberos ticket from the OS (not the Java stack). Otherwise the user has to authenticate a second time (defeating the purpose of single sign-on).

Look at http://java.sun.com/developer/technicalArticles/J2SE/security/. Look down for "Access Native GSS-API" and it talks about a new system property sun.security.jgss.native which when set to true causes Java to use the underlying OS GSS implementation, giving access to the OS level authentication. Perfect!.... except its only supported for Solaris and Linux, not Microsoft Windows.

Java 6 however does appear to have enough support for acting as a server receiving SPNEGO authentication requests from IE and then authenticating that user against Active Directory. Its just the desktop client support that is still incomplete.

5
votes

Use JAAS with an LDAP LoginModule. This will allow you to plug-into the underlying Java security infrastructure.

When you need to take the app offline or "debug" the app, you can easily swap-out the LDAP module for a dummy module. This allows you to continue testing your "security", without depending on Active Directory. Highly testable, decoupled, and you can the authentication scheme at a later time with almost no grief.

4
votes

Project Waffle has both client and server-side code to do SSO on Windows. It's JNA-based, no native libraries required.

0
votes

Check jCifs at http://jcifs.samba.org/

Other than that, stick with LDAP (actually, it should be my first try, but...)

0
votes

Have you considered using the JNA api (allows you to do native calls to the operating system easy)?

You can call the win32 metod GetCurrentUser MSDN documentation at http://msdn.microsoft.com/en-us/library/ms724432(VS.85).aspx. It's located inside Advapi32.dll.

It also has a unicode version, GetCurrentUserW if needed.

And you are right. It does seem that the environment variable can be changed, so that can be misleading to use.

I'm not sure about cross platform implications over 32/64bit windows. If you need the solution in code, I'm sure I could write something up for it.

But yea, just an idea :)

0
votes

You will probably get most flexibility by using Spring Security. You can use it with both JAAS and LDAP authentication.