Fix for OpenSAML 4.3

Signed-off-by: Andrey Pleskach <[email protected]>

plugin-security.policy

@@ -76,7 +76,6 @@ grant {
 
   //SAML policy
   permission java.util.PropertyPermission "*", "read,write";
-  permission org.opensearch.secure_sm.ThreadPermission "modifyArbitraryThread";
 };
 
 grant codeBase "${codebase.netty-common}" {

src/main/java/net/shibboleth/shared/primitive/CleanerSupport.java

@@ -0,0 +1,21 @@
+package net.shibboleth.shared.primitive;
+
+import java.lang.ref.Cleaner;
+import javax.annotation.Nonnull;
+
+import org.opensearch.common.util.concurrent.OpenSearchExecutors;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public final class CleanerSupport {
+    @Nonnull
+    private static final Logger LOG = LoggerFactory.getLogger(CleanerSupport.class);
+
+    private CleanerSupport() {}
+
+    @Nonnull
+    public static Cleaner getInstance(@Nonnull final Class<?> requester) {
+        LOG.debug("Creating new java.lang.ref.Cleaner instance requested by class: {}", requester.getName());
+        return Cleaner.create(OpenSearchExecutors.daemonThreadFactory("cleaners"));
+    }
+}