Github user anmolnar commented on a diff in the pull request:
https://github.com/apache/zookeeper/pull/184#discussion_r221584542
--- Diff: src/java/main/org/apache/zookeeper/common/ZKTrustManager.java ---
@@ -0,0 +1,151 @@
+/**
+ * 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.zookeeper.common;
+
+import org.apache.http.conn.ssl.DefaultHostnameVerifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.net.ssl.SSLEngine;
+import javax.net.ssl.SSLException;
+import javax.net.ssl.X509ExtendedTrustManager;
+import java.net.InetAddress;
+import java.net.Socket;
+import java.net.UnknownHostException;
+import java.security.cert.CertificateException;
+import java.security.cert.X509Certificate;
+
+/**
+ * A custom TrustManager that supports hostname verification via
org.apache.http.conn.ssl.DefaultHostnameVerifier.
+ *
+ * We attempt to perform verification using just the IP address first and
if that fails will attempt to perform a
+ * reverse DNS lookup and verify using the hostname.
+ */
+public class ZKTrustManager extends X509ExtendedTrustManager {
+
+ private static final Logger LOG =
LoggerFactory.getLogger(ZKTrustManager.class);
+
+ private X509ExtendedTrustManager x509ExtendedTrustManager;
+ private boolean serverHostnameVerificationEnabled;
+ private boolean clientHostnameVerificationEnabled;
+
+ private DefaultHostnameVerifier hostnameVerifier;
+
+ /**
+ * Instantiate a new ZKTrustManager.
+ *
+ * @param x509ExtendedTrustManager The trustmanager to use for
checkClientTrusted/checkServerTrusted logic
+ * @param serverHostnameVerificationEnabled If true, this
TrustManager should verify hostnames of servers that this
+ * instance connects to.
+ * @param clientHostnameVerificationEnabled If true, and
verifySSLServerHostname is true, the hostname of a client
--- End diff --
I would just simplify the comment and remove description of this logic. It
should rather go to the documentation, because it's essentially the behaviour
of a configuration setting.
Logic is placed in `createSSLContext`, but that doesn't have any related
parameter.
---
