[keycloak-dev] Proposal - use Ant Plugin for generating JKS files

[Sebastian Laskawiec]

Hey,

Together with Sebi we are working on Certificate-based authentication for
the clients. Our work will require adding at least 2-3 keystores to the
codebase with different DNs and I think this might be a good opportunity to
revisit the way we handle JKS files in the tests.

Currently we push JKS files directly into our repo, which has a couple of
drawbacks:
- it is hard to figure out what's inside the JKS, it requires looking up
for password (usually in some JSON configuration file or hardcoded in the
test) and using keytool (or some similar one) to explore its content.
- It is not git-friendly. Every time we update JKS content we effectively
store another binary file (git doesn't understand binary file changes and
can not diff it).
- we use many different naming and password schemes in our tests.
- it is hard to migrate all keystores to pkcs12 at the same time (JKS
format is deprecated) [0]

I believe most of the issues could be addressed by generating JKS files on
the fly - during the build. In Infinispan we did it with Maven Ant Plugin
[1]. I already created a very limited POC for Keycloak and you can check it
out here [2]. Unfortunately, the process of reverse engineering all those
files is quite time-consuming, so I would like to know your opinion before
moving on.

Of course, generating JKS files on the fly has some drawbacks:
- It increases build time (~1s per keytool invocation, and we probably will
have more than 30 of them).
- it makes testing from IDE a bit harder, you need to run Maven and process
test resources before doing anything. A common workaround is to use `mvn
clean install -DskipTests` and then opening your IntelliJ.

Please let me know what you think.

Thanks,
Sebastian

[0]
https://blogs.oracle.com/jtc/jdk9-keytool-transitions-default-keystore-to-pkcs12
[1]
https://github.com/infinispan/infinispan/blob/master/server/integration/testsuite/pom.xml#L460
[2] https://github.com/keycloak/keycloak/pull/5410