ARTEMIS-5340 ensure PEM provider is truly optional

artemis-core-client/src/main/java/org/apache/activemq/artemis/core/remoting/impl/ssl/PemSupport.java

@@ -0,0 +1,26 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.activemq.artemis.core.remoting.impl.ssl;
+
+import java.security.Security;
+
+public class PemSupport {
+
+   public static void loadProvider() {
+      Security.insertProviderAt(new de.dentrassi.crypto.pem.PemKeyStoreProvider(), Integer.parseInt(System.getProperty("artemis.pemProvider.insertAt", "0")));
+   }
+}

artemis-core-client/src/main/java/org/apache/activemq/artemis/core/remoting/impl/ssl/SSLSupport.java

@@ -352,11 +352,14 @@ public static KeyStore loadKeystore(final String keystoreProvider,
       return ks;
    }
 
-   public static void checkPemProviderLoaded(String keystoreType) {
+   /**
+    * This method calls out to a separate class in order to avoid a hard dependency on the provider's implementation.
+    * This allows folks who don't use PEM to avoid using the corresponding dependency.
+    */
+   public static void checkPemProviderLoaded(String keystoreType) throws Exception {
       if (keystoreType != null && keystoreType.startsWith("PEM")) {
          if (Security.getProvider("PEM") == null) {
-            Security.insertProviderAt(new de.dentrassi.crypto.pem.PemKeyStoreProvider(),
-               Integer.parseInt(System.getProperty("artemis.pemProvider.insertAt", "0")));
+            PemSupport.loadProvider();
          }
       }
    }

artemis-core-client/src/test/java/org/apache/activemq/artemis/core/remoting/impl/netty/PemProviderTest.java

@@ -0,0 +1,61 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.activemq.artemis.core.remoting.impl.netty;
+
+import java.util.Arrays;
+
+import de.dentrassi.crypto.pem.PemKeyStoreProvider;
+import org.apache.activemq.artemis.core.remoting.impl.ssl.SSLSupport;
+import org.junit.jupiter.api.Assumptions;
+import org.junit.jupiter.api.MethodOrderer.OrderAnnotation;
+import org.junit.jupiter.api.Order;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.TestMethodOrder;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+@TestMethodOrder(OrderAnnotation.class)
+public class PemProviderTest {
+
+   static final String PEM_PROVIDER_PACKAGE = "de.dentrassi.crypto.pem";
+
+   @Test
+   @Order(1)
+   public void testPemProviderNotLoaded() {
+      // ensure the PEM provider wasn't already loaded by some other test
+      Assumptions.assumeFalse(Arrays.stream(ClassLoader.getSystemClassLoader().getDefinedPackages()).anyMatch(pkg -> PEM_PROVIDER_PACKAGE.equals(pkg.getName())));
+
+      // use a method from SSLSupport to force the JVM to load it as well as any hard dependencies it has
+      SSLSupport.parseCommaSeparatedListIntoArray("");
+
+      // verify the actual PEM provider class is not loaded; using a literal to avoid loading the actual package/class
+      assertNull(ClassLoader.getSystemClassLoader().getDefinedPackage(PEM_PROVIDER_PACKAGE));
+   }
+
+   /**
+    * This test simply verifies that we're using the right literal for the PEM provider implementation and that it does
+    * actually get loaded when referenced.
+    */
+   @Test
+   @Order(2)
+   public void testPemProviderPackageName() {
+      assertEquals(PEM_PROVIDER_PACKAGE, PemKeyStoreProvider.class.getPackageName());
+      assertNotNull(ClassLoader.getSystemClassLoader().getDefinedPackage(PEM_PROVIDER_PACKAGE));
+   }
+}