NIFI-8403: Generating Self-signed cert on startup when applicable

[gresockj]

Description of PR

Adding autogeneration of self-signed certificate in a default keystore/truststore when applicable. Conditions for autogeneration are as follows:

nifi.properties contains the following configuration:

nifi.web.https.port=<value> // Must be set
nifi.security.keystore=<value> // Recommend testing with ./conf/keystore.p12
nifi.security.truststore=<value> // Recommend testing with ./conf/truststore.p12

Additionally, the keystore and truststore files as configured must not exist on the file system at those locations in order for them to be autogenerated. The code will not attempt to generate these files if one or both of them is present in the configured locations.

The results will be:

• A self-signed certificate (CN=localhost) is generated with an expiration of 60 days. The cert will be configured with Subject Alternative Names for the localhost hostname and address, as well as any values found in the following nifi.properties: nifi.remote.input.host, nifi.web.https.host, nifi.web.proxy.host, nifi.cluster.load.balance.address
• A keystore containing the corresponding private key is placed at the path configured in nifi.security.keystore
• A truststore containing the trusted certificate entry is placed at the path configured in nifi.security.truststore
• Passwords generated with a secure random are used to protect the keystore/truststore
• The following properties are populated appropriately in nifi.properties:

nifi.security.keystoreType=PKCS12
nifi.security.keystorePassword=<generated password>
nifi.security.keyPassword=<same as keystore password>
nifi.security.truststoreType=PKCS12
nifi.security.truststorePassword=<generated password>

In order to streamline the review of the contribution we ask you
to ensure the following steps have been taken:

For all changes:

• Is there a JIRA ticket associated with this PR? Is it referenced
  in the commit message?

• Does your PR title start with NIFI-XXXX where XXXX is the JIRA number you are trying to resolve? Pay particular attention to the hyphen "-" character.

• Has your PR been rebased against the latest commit within the target branch (typically main)?

• Is your initial contribution a single, squashed commit? Additional commits in response to PR reviewer feedback should be made on this branch and pushed to allow change tracking. Do not squash or use --force when pushing to allow for clean monitoring of changes.

For code changes:

• Have you ensured that the full suite of tests is executed via mvn -Pcontrib-check clean install at the root nifi folder?
• Have you written or updated unit tests to verify your changes?
• Have you verified that the full build is successful on JDK 8?
• Have you verified that the full build is successful on JDK 11?
• If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under ASF 2.0?
• If applicable, have you updated the LICENSE file, including the main LICENSE file under nifi-assembly?
• If applicable, have you updated the NOTICE file, including the main NOTICE file found under nifi-assembly?
• If adding new Properties, have you added .displayName in addition to .name (programmatic access) for each of the new properties?

For documentation related changes:

• Have you ensured that format looks appropriate for the output in which it is rendered?

Note:

Please ensure that once the PR is submitted, you check GitHub Actions CI for build issues and submit an update to your PR as soon as possible.

[exceptionfactory]

Thanks for your work on this feature @gresockj. Encapsulating the implementation in a separate utility class looks good. See individual comments regarding implementation details and consideration of logging for various situations.

[exceptionfactory]

Thanks for the updates @gresockj! It looks close to completion, I made a few additional comments. As an injection into the NiFi startup process, this should be as clean as possible to avoid issues, so thanks for continuing to work through the details.

[exceptionfactory]

Thanks for the work on this feature @gresockj! Verified runtime behavior with current default properties as well as with the keystore and truststore file paths specified.

[exceptionfactory]

Thanks for making updating the logic to check password properties @gresockj, those changes look good. Do you have any additional feedback @bbende?

[bbende]

Latest changes look good to me, going to merge, thanks!