Address code review comments

Signed-off-by: Andriy Redko <andriy.redko@aiven.io>

modules/transport-netty4/src/main/java/org/opensearch/http/netty4/ssl/SecureNetty4HttpServerTransport.java

@@ -55,6 +55,9 @@
 import io.netty.handler.ssl.ApplicationProtocolNegotiationHandler;
 import io.netty.handler.ssl.SslHandler;
 
+/**
+ * @see <a href="https://github.com/opensearch-project/security/blob/main/src/main/java/org/opensearch/security/ssl/http/netty/SecuritySSLNettyHttpServerTransport.java">SecuritySSLNettyHttpServerTransport</a>
+ */
 public class SecureNetty4HttpServerTransport extends Netty4HttpServerTransport {
     private static final Logger logger = LogManager.getLogger(SecureNetty4HttpServerTransport.class);
     private final SecureTransportSettingsProvider secureTransportSettingsProvider;

modules/transport-netty4/src/main/java/org/opensearch/transport/netty4/ssl/DualModeSslHandler.java

@@ -33,6 +33,8 @@
 
 /**
  * Modifies the current pipeline dynamically to enable TLS
+ *
+ * @see <a href="https://github.com/opensearch-project/security/blob/main/src/main/java/org/opensearch/security/ssl/transport/DualModeSSLHandler.java">DualModeSSLHandler</a>
  */
 public class DualModeSslHandler extends ByteToMessageDecoder {
 

modules/transport-netty4/src/main/java/org/opensearch/transport/netty4/ssl/SecureConnectionTestUtil.java

@@ -28,6 +28,8 @@
  * SSL Check will be done by sending an OpenSearch Ping to see if server is replying to pings.
  * Following that a custom client hello message will be sent to the server, if the server
  * side has OpenSearchPortUnificationHandler it will reply with server hello message.
+ *
+ * @see <a href="https://github.com/opensearch-project/security/blob/main/src/main/java/org/opensearch/security/ssl/util/SSLConnectionTestUtil.java">SSLConnectionTestUtil</a>
  */
 class SecureConnectionTestUtil {
     private static final Logger logger = LogManager.getLogger(SecureConnectionTestUtil.class);

modules/transport-netty4/src/main/java/org/opensearch/transport/netty4/ssl/SecureNetty4Transport.java

@@ -65,6 +65,9 @@
 import io.netty.handler.codec.DecoderException;
 import io.netty.handler.ssl.SslHandler;
 
+/**
+ * @see <a href="https://github.com/opensearch-project/security/blob/main/src/main/java/org/opensearch/security/ssl/transport/SecuritySSLNettyTransport.java">SecuritySSLNettyTransport</a>
+ */
 public class SecureNetty4Transport extends Netty4Transport {
 
     private static final Logger logger = LogManager.getLogger(SecureNetty4Transport.class);

modules/transport-netty4/src/main/java/org/opensearch/transport/netty4/ssl/SslUtils.java

@@ -20,6 +20,9 @@
 
 import io.netty.buffer.ByteBuf;
 
+/**
+ * @see <a href="https://github.com/opensearch-project/security/blob/main/src/main/java/org/opensearch/security/ssl/util/TLSUtil.java">TLSUtil</a>
+ */
 public class SslUtils {
     private static final String[] DEFAULT_SSL_PROTOCOLS = { "TLSv1.3", "TLSv1.2", "TLSv1.1" };
 

server/src/main/java/org/opensearch/plugins/SecureTransportSettingsProvider.java

@@ -28,17 +28,19 @@ public interface SecureTransportSettingsProvider {
     /**
      * An exception handler for errors that might happen while secure transport handle the requests.
      *
+     * @see <a href="https://github.com/opensearch-project/security/blob/main/src/main/java/org/opensearch/security/ssl/SslExceptionHandler.java">SslExceptionHandler</a>
+     *
      * @opensearch.experimental
      */
     @ExperimentalApi
+    @FunctionalInterface
     interface ServerExceptionHandler {
-        static ServerExceptionHandler NOOP = new ServerExceptionHandler() {
-            @Override
-            public void onError(Throwable t) {
-                // NOOP
-            }
-        };
+        static ServerExceptionHandler NOOP = t -> {};
 
+        /**
+         * Handler for errors happening during the server side processing of the requests
+         * @param t the error
+         */
         void onError(Throwable t);
     }