SecurityManager is deprecated for removal

[cushon]

The SecurityManager API is deprecated for removal, see https://openjdk.org/jeps/486

It is being used here:

ldapsdk/src/com/unboundid/util/ssl/cert/ManageCertificatesSecurityManager.java

Lines 51 to 59 in 12c0673

	/**
	* This class provides an implementation of a Java security manager that will
	* prevent System.exit from being invoked. This is needed when invoking the
	* keytool utility programmatically via reflection, because it has the potential
	* to call System.exit if an error is encountered, and we don't want to allow
	* that (but we do want to be able to trap it).
	*/
	@ThreadSafety(level=ThreadSafetyLevel.NOT_THREADSAFE)
	final class ManageCertificatesSecurityManager

[dirmgr]

It is true that the LDAP SDK ships with a SecurityManager implementation. However, this isn’t actually used anywhere in the LDAP SDK, and it hasn’t been used in quite some time. It was introduced in 2017 as part of the initial version of the manage-certificates tool, back when it needed to invoke keytool for certain functions, and it was used to prevent the possibility that keytool could do something like call System.exit in response to an error.

The manage-certificates tool no longer has any dependency on the keytool utility, and hasn’t for quite some time. As such, the security manager isn’t actually used anymore for any purpose. It’s only referenced by unit tests that cover it. Since it’s not part of the LDAP SDK’s public API, it would be possible to remove it, and I’ll probably do that for the next release. However, its presence doesn’t adversely affect anything.

[dirmgr]

I have removed the security manager. Since it's never been part of the public API, and since this has no effect on any LDAP SDK functionality, it won't be mentioned in the release notes for the next release.