--- a/src/share/classes/sun/security/util/HostnameChecker.java	Sun Jul 16 00:29:10 2017 +0100
+++ b/src/share/classes/sun/security/util/HostnameChecker.java	Tue Jul 18 00:17:03 2017 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2006, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,6 +26,7 @@
 package sun.security.util;
 
 import java.io.IOException;
+import java.net.IDN;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.util.*;
@@ -186,6 +187,15 @@
      */
     private void matchDNS(String expectedName, X509Certificate cert)
             throws CertificateException {
+        // Check that the expected name is a valid domain name.
+        try {
+            // Using the checking taken from OpenJDK 8's SNIHostName
+            checkHostName(expectedName);
+        } catch (IllegalArgumentException iae) {
+            throw new CertificateException(
+                "Illegal given domain name: " + expectedName, iae);
+        }
+
         Collection<List<?>> subjAltNames = cert.getSubjectAlternativeNames();
         if (subjAltNames != null) {
             boolean foundDNS = false;
@@ -257,6 +267,18 @@
      * may contain the wildcard character *
      */
     private boolean isMatched(String name, String template) {
+        // check the validity of the domain name template.
+        try {
+            // Replacing wildcard character '*' with 'x' so as to check
+            // the domain name template validity.
+            //
+            // Using the checking taken from OpenJDK 8's SNIHostName
+            checkHostName(template.replace('*', 'x'));
+        } catch (IllegalArgumentException iae) {
+            // It would be nice to add debug log if not matching.
+            return false;
+        }
+
         if (checkType == TYPE_TLS) {
             return matchAllWildcards(name, template);
         } else if (checkType == TYPE_LDAP) {
@@ -366,4 +388,22 @@
         }
         return name.endsWith(afterWildcard);
     }
+
+    // check the validity of the string hostname
+    private void checkHostName(String hostname) {
+        hostname = IDN.toASCII(Objects.requireNonNull(hostname,
+                                   "Server name value of host_name cannot be null"),
+                               IDN.USE_STD3_ASCII_RULES);
+
+        if (hostname.isEmpty()) {
+            throw new IllegalArgumentException(
+                "Server name value of host_name cannot be empty");
+        }
+
+        if (hostname.endsWith(".")) {
+            throw new IllegalArgumentException(
+                "Server name value of host_name cannot have the trailing dot");
+        }
+    }
+
 }