[keycloak-dev] Authentication sessions & Action tokens PR

[Marek Posolda]

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