Kerberos Delegation thru Windows' ISAPI?

[Michael B Allen]

On Fri, 8 Sep 2006 11:33:31 +0200
vadim <vadim.tarassov at swissonline.ch> wrote:

> Hi Michael,
> 
> If I understood you correctly your goal is to trigger from MS IIS something 
> written in java using kerberos authentication. I would suggest you to put 
> together a servlet in tomcat and make IIS to authenticate itself against this 
> servlet using SPNEGO. 

Yeah, we know we can do SPNEGO entriely on the Tomcat side (Vintela
does it) but some shops prefer to use IIS's IWA feature through and
through. You can still run through IIS but if you do you have to turn
off IWA or IIS will intercept the GSSAPI tokens.

So I'm trying to determine if I can get around the logon session
partitioning problem. The ideal solution would be to enable Tomcat's ISAPI
redirector to copy the TGT from the IIS worker process logon session to
the Tomcat worker's logon session credential cache. But I suppose that's
a lost cause ...

> Most probably you will have to develop SPNEGO authenticator in Tomcat 
> yourself. I was looking for this thing a while ago in inet, and could not 
> find anything meaningfull, and therefore I have developed something similar 
> myself. 

There's also jcifs-ext on sourceforge (the regular jcifs Filter only
does NTLM).  It's fallen by the wayside a little but the JBOSS folks
have tossed it around. Personally I don't think the code is used enough
to give to a customer.

> What you will have to do in such case, is to extract GSSAPIv2 tokens from 
> SPNEGO tokens which you will receive from IIS, or otherwise build SPNEGO 
> tokens from GSSAPIv2 tokens provided by sun GSSAPIv2 implementation. That's 
> you will need an API to parse DER encoded ASN.1 structures, or otherwise 
> encode ASN.1 structures. 
> 
> Even for this you will have troubles to find meaningfull API unless you can 
> use IAIK. If you have to stay "opensource" you may probably want to try 
> www.bouncycastle.org, they claim to have library to work with ASN.1 
> structures.
> 
> Best regards, vadim tarassov
> 
> On Friday 08 September 2006 00:20, Michael B Allen wrote:
> > I have a Kerberos delegation issue caused by the separation of IIS worker
> > processes and the Tomcat web server process on Windows.
> >
> > Specifically, I have a customer running Tomcat through ISAPI
> > on Windows with ISS using Integrated Windows Authentication
> > (Kerberos). Authentication is working. The getRemoteUser method returns
> > the user's expected identity. Delegation is working. An ASP can use
> > the clients credentials to request another protected page on a second
> > IIS server. Note, impersonation is not used in any way shape or form
> > (nor would it work).
> >
> > I put together a Kerberos capable HTTP client and tried to invoke it
> > through the IIS authenticated Servlet. This does not work. The JGSS
> > routines cannot find the delegated ticket (TGT).
> >
> > Can anyone guess as to why this is?
> >
> > My thinking is that even though the Tomcat process and IIS workers are
> > running under the same service account Tomcat servlets do not have
> > access to the IIS worker's credential cache because the credential
> > cache is per-logon session and IIS creates a new logon session with each
> > authentication. Does this sound right? I can't find any documentation
> > about this scenario.
> >
> > My next thought was to export the security context but someone just
> > posted a message that indicated Sun's Java doesn't support exporting
> > the credential. If that's true I guess I'm toast?
> >
> > It would be a nice feature if Tomcat's ISAPI dll used
> > LsaGetLogonSessionData and similar in the IIS worker to get any TGT
> > present and ship it over to the Tomcat worker so Java can get to it. A
> > lot of shops are MS SSO only and don't want a separate container for Java.
> >
> > Mike
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-- 
Michael B Allen
PHP Active Directory SSO
http://www.ioplex.com/