This commit removes and now forbids all uses of
Collections#shuffle(List) and Random#<init>() across the codebase. The
rationale for removing and forbidding these methods is to increase test
reproducibility. As these methods use non-reproducible seeds, production
code and tests that rely on these methods contribute to
non-reproducbility of tests.
Instead of Collections#shuffle(List) the method
Collections#shuffle(List, Random) can be used. All that is required then
is a reproducible source of randomness. Consequently, the utility class
Randomness has been added to assist in creating reproducible sources of
randomness.
Instead of Random#<init>(), Random#<init>(long) with a reproducible seed
or the aforementioned Randomess class can be used.
Closes#15287
Since 2.2 we run all scripts with minimal privileges, similar to applets in your browser.
The problem is, they have unrestricted access to other things they can muck with (ES, JDK, whatever).
So they can still easily do tons of bad things
This PR restricts what classes scripts can load via the classloader mechanism, to make life more difficult.
The "standard" list was populated from the old list used for the groovy sandbox: though
a few more were needed for tests to pass (java.lang.String, java.util.Iterator, nothing scary there).
Additionally, each scripting engine typically needs permissions to some runtime stuff.
That is the downside of this "good old classloader" approach, but I like the transparency and simplicity,
and I don't want to waste my time with any feature provided by the engine itself for this, I don't trust them.
This is not perfect and the engines are not perfect but you gotta start somewhere. For expert users that
need to tweak the permissions, we already support that via the standard java security configuration files, the
specification is simple, supports wildcards, etc (though we do not use them ourselves).
While the GreekAnalyzer supports stemming, custom analyzers for the greek language cannot be build because there is no GreekStemmer (although lucene has one).
Jason Tedor
Robert Muir
Areek Zillur
Ryan Ernst
Shay Banon
Njal Karevoll
George Chatzigeorgiou