Hi Marek,
There are a lot of different ways how load balancers can create stickiness. They can use
source or destination IP, they can use cookie insertion or cookie rewriting adding a route
identifier to the response (this is similar to what you did), or they can also maintain
sticky tables holding state like opaque session ids to map future requests to the right
node.
There is some documentation how to do this in a simple way for nginx
(
https://www.nginx.com/products/session-persistence/), while
(
https://cbonte.github.io/haproxy-dconv/1.8/configuration.html#4.2-stick%2...)
shows you can store arbitrary things to realize stickiness in HAProxy if you want to (e.g
to act differently for requests coming from a proxy).
Anyways, I guess my point is that you can create session stickiness by just configuring
your load balancer to use whatever mechanism you prefer. Ideally, Keycloak should not care
and should not require a specific mechanism to be used. If I want a higher level of
protection for my cluster more and not give out any information, I should be able to do
this (at the cost of more work for the load balancers).
Of course, I am assuming Keycloak still works fine without session stickiness being
configured correctly (just with reduced efficiency).
Best regards,
Sebastian
Mit freundlichen Grüßen / Best regards
Sebastian Schuster
Engineering and Support (INST/ESY1)
Bosch Software Innovations GmbH | Schöneberger Ufer 89-91 | 10785 Berlin | GERMANY |
www.bosch-si.com
Tel. +49 30 726112-485 | Fax +49 30 726112-100 | Sebastian.Schuster(a)bosch-si.com
Sitz: Berlin, Registergericht: Amtsgericht Charlottenburg; HRB 148411 B
Geschäftsführung: Dr.-Ing. Rainer Kallenbach, Michael Hahn
-----Original Message-----
From: Marek Posolda [mailto:mposolda@redhat.com]
Sent: Montag, 15. Mai 2017 13:02
To: Schuster Sebastian (INST/ESY1) <Sebastian.Schuster(a)bosch-si.com>;
keycloak-dev(a)lists.jboss.org
Subject: Re: [keycloak-dev] Authentication sessions & Action tokens PR
On 15/05/17 10:20, Schuster Sebastian (INST/ESY1) wrote:
Hi Marek,
I guess using sticky sessions is fine. I was only referring to the
fact that the cookie content looked like it contains some route
identifier that is visible to the client. This way a client could find
out how many nodes are behind the load balancer or it could target
individual nodes. I think this would be a security issue and should be avoided by using
just an opaque session id in the cookie. The load balancer will keep track of which node
generated the session id and will route further requests accordingly.
Yes, it works
this way. However AFAIK using the cookie to route requests is standard way, which most
loadbalancers are using. Exposing some informations about underlying routes, and possibly
count of cluster nodes, might be a price to pay.
It is possible to avoid it by:
- Avoid sticky sessions.
- I suppose some loadbalancers might have tools to somehow hide this (eg. encrypt the
cookie), or track the mapping of the session-to-routes in some internal memory.
I must admin that I am not so experienced in what admins are typically doing. I am curious
about your setup. Do you want to avoid sticky sessions at all or your loadbalancer has
some other way to track them rather than through browser cookie? Which loadbalancer are
you using?
Marek
Best regards,
Sebastian
Mit freundlichen Grüßen / Best regards
Sebastian Schuster
Engineering and Support (INST/ESY1)
Bosch Software Innovations GmbH | Schöneberger Ufer 89-91 | 10785
Berlin | GERMANY |
www.bosch-si.com Tel. +49 30 726112-485 | Fax +49
30 726112-100 | Sebastian.Schuster(a)bosch-si.com
Sitz: Berlin, Registergericht: Amtsgericht Charlottenburg; HRB 148411
B
Geschäftsführung: Dr.-Ing. Rainer Kallenbach, Michael Hahn
-----Original Message-----
From: Marek Posolda [mailto:mposolda@redhat.com]
Sent: Montag, 15. Mai 2017 09:47
To: Schuster Sebastian (INST/ESY1) <Sebastian.Schuster(a)bosch-si.com>;
keycloak-dev(a)lists.jboss.org
Subject: Re: [keycloak-dev] Authentication sessions & Action tokens PR
Hi,
we are adding some sticky session support, so this routeId is used by the loadbalancer to
track to which cluster backend node it should forward the request. This is pretty much
similar to what Wildfly is doing to track the session stickiness of servlet httpSessions.
However I've added the SPI, so it would be possible to avoid adding the route to the
cookie or use different strategy to add the route to the request.
But without sticky sessions, you might have worse performance in cluster environment.
Btv. do you want to avoid sticky sessions at all or your loadbalancer has some other way
to track them rather than through browser cookie?
Which loadbalancer are you using?
Marek
On 12/05/17 08:30, Schuster Sebastian (INST/ESY1) wrote:
> Hi Marek,
>
> Is there a technical reason for including the routeid explicitely in the Cookie?
> Normally, I would be reluctant to give out information about the
> setup behind the load balancer, like how many nodes the cluster consists of.
>
> Best regards,
> Sebastian
>
> Mit freundlichen Grüßen / Best regards
>
> Sebastian Schuster
>
> Engineering and Support (INST/ESY1)
> Bosch Software Innovations GmbH | Schöneberger Ufer 89-91 | 10785
> Berlin | GERMANY |
www.bosch-si.com Tel. +49 30 726112-485 | Fax +49
> 30 726112-100 | Sebastian.Schuster(a)bosch-si.com
>
> Sitz: Berlin, Registergericht: Amtsgericht Charlottenburg; HRB 148411
> B
> Geschäftsführung: Dr.-Ing. Rainer Kallenbach, Michael Hahn
>
>
>
>
> -----Original Message-----
> From: keycloak-dev-bounces(a)lists.jboss.org
> [mailto:keycloak-dev-bounces@lists.jboss.org] On Behalf Of Marek
> Posolda
> Sent: Donnerstag, 11. Mai 2017 22:33
> To: keycloak-dev(a)lists.jboss.org
> Subject: [keycloak-dev] Authentication sessions & Action tokens PR
>
> I've finally sent the PR
>
https://github.com/keycloak/keycloak/pull/4132
> with the work for $subject. This includes the work by Hynek and me on Authentication
sessions and action tokens. We finally managed to sort various kinks and have all tests
passing.
>
> Some things and concepts were already discussed in some previous threads [1], [2],
[3] and during presentations. So I won't repeat everything.
> Just some highlights:
>
> - authenticationSession replaces the old ClientSessionModel. There is separate
AuthenticationSessionProvider and separate infinispan cache
"authenticationSessions" . This cache typicaly won't be replicated over all
the datacenters, but instead it will rely on browser sticky sessions, hence browser will
be redirected by loadbalancer to correct node in correct datacenter. So typicaly there
won't be cross-dc communication needed during authentication.
>
> - I've added some support for sticky sessions already. In cluster environment,
the authentication session cookie is created in the format like
"sessionId.routeId" . For example
"aabf27e6-7945-4d3a-a023-c1c64f7fdab4.node1". Pretty much same format like
JSESSIONID cookie used as a cookie in classic java web applications. One side-effect of
this PR is, that it also covers the support for running clustering tests on embedded
undertow and from IDE.
>
> - Support for browser back/forward/refresh buttons was improved since my presentation
last month. There are no browser redirects after the form submit, but instead there is a
change of browser history through the javascript history.replaceState function. This
pretty much removes all the POST requests from the browser history and helps with having
good experience regarding browser buttons. In case that you have old browser not
supporting this, the behaviour is same like before. Hence default browser "Page
expired" page after clicking back from POST request (same behaviour like latest
master). There are no additional redirects.
>
> - For action tokens, Hynek will likely add more. For quick summary, I can just
mention that action token is JWT signed by realm secret key.
> You can generate it in your authenticator or requiredActionProvider and send it
somehow to user. Typically through email. Once user opens the actionToken URL from the
email, it is processed on LoginActionsService endpoint, which provides most of the common
basic functionality and verifications. LoginActionsService then finds the correct
implementation of ActionTokenHandler, which is separate SPI. This allows to specify the
details how can be actionToken handled, whether it's single use or not etc. There is
support for the scenario if user opened link in the same browser when he started
authenticationSession or in different browser etc.
>
> - Regarding PR, I've tried to squash the commits a bit. However PR still consists
of more commits to track at least what was done by me and what by Hynek. Do you think it
is the issue to have more commits in the PR?
>
> - This is hopefully the bigest task for the cross-dc support. My hope is that PR can
be reviewed and merged soon as the work is more and more unsynced with the latest master
and rebasing is a bit of pain. But I understand that this will require time. There is
change in 324 files :) There are still a lot things to cover for cross-dc, but I think
those can be done in smaller pieces and commit more often.
>
> [1]
>
http://lists.jboss.org/pipermail/keycloak-dev/2017-March/009066.html
> [2]
>
http://lists.jboss.org/pipermail/keycloak-dev/2017-March/009121.html
> [3]
>
http://lists.jboss.org/pipermail/keycloak-dev/2017-March/009125.html
>
> Marek
>
> _______________________________________________
> keycloak-dev mailing list
> keycloak-dev(a)lists.jboss.org
>
https://lists.jboss.org/mailman/listinfo/keycloak-dev
>
> _______________________________________________
> keycloak-dev mailing list
> keycloak-dev(a)lists.jboss.org
>
https://lists.jboss.org/mailman/listinfo/keycloak-dev