ZOOKEEPER-3404. Downgrade BouncyCastle to 1.60

[anmolnar]

I've seen a lot of test timeout errors with QuorumSSL tests since I upgraded master to BouncyCastle 1.61 due to a Java 9 warning. The warning has been reported by Enrico Olivelli which we tried to solve by the upgrade, but the warning message is still present so I don't see any harm in downgrading to the previous version.

https://issues.apache.org/jira/browse/ZOOKEEPER-3404

[eolivelli]

As we are using BC only for tests it is okay to downgrade in order to make tests more stable.

btw if we have these problems now someday we will see them again when we will need to upgrade.
Aren't we using BC only for generating certs and keys ? it is not used by the runtime.

BC comes with its own Security Providers, I am afraid that it not polluting the classpath during tests executions. The JVM (Javax Crypto) selects Security Providers by using what is on the classpath.
It is a problem if during tests execution we are using a Security Provider that it is not used in production.

We should add debug in every security-related utility and dump which Security Provider is in use.
In order to be sure about the security provider we are using every Javax Crypto utility has a way to force the provider without using auto discovery.

We should also add Netty (Google) Boring SSL library in order to be sure about the SSL implementation we are using.

Unfortunately we are not using Netty yet on server to server communication, as so I guess we are more fragile in this Security Provider selection.

cc @enixon

[anmolnar]

btw if we have these problems now someday we will see them again when we will need to upgrade.
Aren't we using BC only for generating certs and keys ? it is not used by the runtime.

@eolivelli This is valid. BC is for testing only currently and we'll face this problem again once we need to upgrade to address a CVE for example. However that could be a more recent version of BC where they identify and fix the performance regression.

Other option could be to improve QuorumSSL tests: it's already running for 5-6 minutes which is kinda odd for unit tests. I'll do some research on that side to find where the bottleneck is.

Wrt to Security Providers I think you're right, though I'm not an expert of Java Security, so not sure how to address the problem properly. I suggest to keep this patch for the performance problem only for now.

Please see my comments / evidence in Jira too.

[nkalmar]

Then I think we have an agreement for the downgrade. For now, this will solve the performance issue on Quorum SSL tests. Thanks Andor.

[nkalmar]

Thanks @anmolnar , merged to master and 3.5

[enixon]

@eolivelli @anmolnar - one of you want to open a ticket for the improvements mentioned above? Getting the dependencies clarified and reducing the running time of the SSL tests are good improvements.