Fix Blake2b hash

[terryquigleysas]

Description

• Bug fix
• Blake2b is deterministic. Passing the parameters incorrectly results in the wrong hash being produced.
• What is the old behavior before changes and new behavior after changes?
  This may be considered a "Breaking Change" for 3.0.0 as the hashes will now be different - correct, but different from before.

Issues Resolved

Resolves #4274

Testing

Updated existing tests.
Ran Bulk Integration Test action against the branch.
Local testing.

Check List

• New functionality includes testing
• New functionality has been documented
• New Roles/Permissions have a corresponding security dashboards plugin PR
• API changes companion pull request created
• Commits are signed per the DCO using --signoff

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[nibix]

Note: In a mixed cluster state, this will yield inconsistent results: Some nodes will hash value A to hash X, while other nodes will hash value A to hash Y. This will especially affect aggregations. Are we okay with this (genuine question)? In any case, this should be documented.

[terryquigleysas]

Note: In a mixed cluster state, this will yield inconsistent results: Some nodes will hash value A to hash X, while other nodes will hash value A to hash Y. This will especially affect aggregations. Are we okay with this (genuine question)? In any case, this should be documented.

@nibix Thank you for your comment. That is not something that I would have been aware of.

I still strongly lean towards putting this change in.

• It is a clear bug with incorrect behavior that should be fixed
• Now that version 3.x is imminent would be a good time to make the change
• I totally agree that any potential behavior differences should be documented

[nibix]

@terryquigleysas One way to work around that issue would be to gate the new behavior by a config option that can be changed at runtime (In config.yml for example). That way, the behavior can be changed from old to new nearly instantaneously, thus reducing the chance of inconsistent aggregations massively.