By the way, SpnegoAuthSupplier now checks for GSSCredential on the CXF
message and will use it if it is there to get a new token - that might
simplify a bit the propagation in the future for cases when no CXF is
involved to get the original in request
Sergey
On 18/07/12 17:10, Sergey Beryozkin wrote:
Hi Josef
On 18/07/12 15:47, Josef Bajada wrote:
Hi Sergey,
In my case the endpoint is a simple<jaxws:client> specified in the
Spring app-context and injected to a few Controllers or similar classes.
The only extra thing is that we want to 'impersonate' or 'delegate'
the user's credentials so that any call we do from the Web Service
client appears as if it is being done by the logged in user (the
Tomcat principal of the web app which is in fact the client of the web
service).
Thanks, that answers my question. Specifically, no CXF is involved to
accept the request, it's only used to make the outbound request.
As I've mentioned in the previous message, a server-side CXF filter is
now available which manages the Negotiate scheme and can be used to make
it pretty easy to propagate the available user credential, provided it
is available, over to the outbound client.
However this filter would be of interest only if CXF also acted as a
receiver of the original request
Cheers, Sergey
Josef
-----Original Message-----
From: Sergey Beryozkin [mailto:sberyoz...@gmail.com]
Sent: 18 July 2012 14:33
To: users@cxf.apache.org
Subject: Re: Kerberos authentication using delegation from Principal
Ticket
On 18/07/12 13:05, Sergey Beryozkin wrote:
Hi Christian, All
On 18/07/12 10:06, Christian Schneider wrote:
Hi Sergey and Josef,
in Kerberos there are two kinds of tickets. The Ticket Granting
Ticket
(TGT) together with a session key is the one issued for the user
after he authenticates on his machine. This ticket then allows to get
a Service Ticket (ST) for a certain server. This service ticket is
typically then forwarded to the webserver during SPNEGO.
So on the server side we can use the ST to authenticate the user but
I am not sure how we can use it to get a Service Token for the next
server. In standard Kerberos this is not possible as far as I know
but Microsoft has a Kerberos extension that allows this. I am not
sure though if this can be used from Java.
In any case the username alone is obviously not enough to get another
ticket. What may be possible is to establish an authentication
context using subject.doAs after the authentication using the ST. In
this context it may then be possible to get another ST but I am not
sure how this works.
So using an STS or Fediz may be the more solid way to solve this.
The quick test shows that the the server side validator is capable of
getting GSSCredential using GSSContext.getDelegCred() (the method name
is a bit cryptic I have to say :-)) but only if the initiator
(SpnegoAuthSupplier) sets the cred delegation property to true (or I
assume if the relevant login process say at the Tomcat level allows
for it).
Next, SpnegoAuthSupplier needs to check if GSSCredential is already
available on the message and if yes, just pass it to the context
creation call and let the context populate the token, without
attempting to log in again.
The delegated GSSCredential can be set by the code, before a WS/RS
client is invoked again.
I'm going to do few minor updates (at the JAX-RS level first) and then
push them to CXF interceptors, for cases like the one Josef is dealing
with easily handled at WS call level too
I've done the updates but I'm going to wait with pushing the server
side negotiate handler code to CXF interceptor. Colm has implemented
the advanced WS-Security level Kerberos support, but I'm not sure it
can be needed at the CXF WS end without WS-Sec
Josef, in your case, how the endpoint is implemented ? Is CXF involved
at all, except for the need to do the outbound call with CXF ?
Sergey
Christian
Am 18.07.2012 01:15, schrieb Sergey Beryozkin:
Hi Josef
On 18/07/12 00:03, Josef Bajada wrote:
Hi Sergey,
Yes the Principal will be available (i.e. the Username).
I am thinking that we will need to generate the new token for the
remote service (Sharepoint) from the original Token we had received
from the browser. So we would need to do gsscontext.getDelegCr() to
get the Delegate Credentials for the user and get the new token
from that, so that we put it in the outbound HTTP header.
As far as I know (again I could be mistaken), the old ticket would
be only valid for our URL (SPN), and a new one would be needed for
the Sharepoint URL.
That is pretty interesting. I just happen to have spent few days
only on the subject, so hope our security experts can help :-).
I thought that the tickets that can be 'forwarded' if the kdc
configuration allows for that.
But may be not, may be gsscontext.getDelegCr() has to be called.
I think that a case like this has to be managed in a simpler way in
CXF, though probably at the moment the way you suggest is the way
to go.
I've just added a jaxrs filter but I can definitely push most of the
code to the CXF in interceptor. This filter currently validates the
in service ticket only plus sets a basic SecurityContext. However it
can be configured to propagate the other useful info for
SpnegoAuthSupplier to reuse when this info is available on the
message...
Hope you can make it all work - please share the code when you are
done and we can put some of it at the base CXF level
Cheers, Sergey
Josef Bajada
Senior Technical Architect
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