NIFI-8096 Deprecated ClientAuth references in SSLContextService

[exceptionfactory]

Description of PR

NIFI-8096 Deprecates createSSLContext() methods in SSLContextService and adds a createContext() method that does not use the ClientAuth enumeration. Updated extension components to use SSLContextService.createContext() in place of deprecated methods.

Removed references to ClientAuth from internal SslContextFactory class, and refactored framework classes to eliminate unnecessary usage of ClientAuth.

Updated ListenHTTP to call SslContextBuilder.Server.setNeedClientAuth(true) when the Client Authentication property is REQUIRED and call setWantClientAuth(true) when the Client Authentication property is WANT.

These changes remove attempts in SslContextFactory to modify the default SSLParameters object, which is a read-only representation for the Java Virtual Machine configuration. Deprecating methods on SSLContextService that use ClientAuth is necessary to clarify component behavior.

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[markap14]

Thanks @exceptionfactory for the update. Definitely cleans up a lot of code that wasn't necessary! I did have one concern though, with changing the default value on ListenHTTP from REQUIRE to WANT client auth. We should remain as secure as possible by default.

[markap14]

I don't think we want to make this change. The default value should always lean toward being more secure, not less secure. And if I set an SSL Context on the processor, I would assume mutual auth is going to happen unless i explicitly change it. This is especially true, since that's always been the behavior in the past.

[exceptionfactory]

Previous behavior inferred requiring a client certificate when the SSLContextService was configured with trust store properties, falling back to wanting a client certificate in the absence of trust store properties. Making REQUIRED the default value going forward sounds like the best approach. Perhaps putting a comment in future release notes indicating this change in behavior would be worthwhile for users of ListenHTTP who do not require clients to provide certificates.

[exceptionfactory]

Thanks for the review @markap14. I pushed an update to address your comments.

[markap14]

Thanks @exceptionfactory! All looks good. +1 merged to main