--- a/jdk/src/java.security.jgss/share/classes/sun/security/krb5/KrbKdcRep.java	Tue Jul 21 14:18:07 2015 -0700
+++ b/jdk/src/java.security.jgss/share/classes/sun/security/krb5/KrbKdcRep.java	Tue Jul 21 18:02:36 2015 +0800
@@ -75,10 +75,11 @@
             }
         }
 
-        // XXX Can renew a ticket but not ask for a renewable renewed ticket
-        // See impl of Credentials.renew().
-        if (req.reqBody.kdcOptions.get(KDCOptions.RENEWABLE) !=
-            rep.encKDCRepPart.flags.get(KDCOptions.RENEWABLE)) {
+        // Reply to a renewable request should be renewable, but if request does
+        // not contain renewable, KDC is free to issue a renewable ticket (for
+        // example, if ticket_lifetime is too big).
+        if (req.reqBody.kdcOptions.get(KDCOptions.RENEWABLE) &&
+                !rep.encKDCRepPart.flags.get(KDCOptions.RENEWABLE)) {
             throw new KrbApErrException(Krb5.KRB_AP_ERR_MODIFIED);
         }
 

--- a/jdk/test/sun/security/krb5/auto/KDC.java	Tue Jul 21 14:18:07 2015 -0700
+++ b/jdk/test/sun/security/krb5/auto/KDC.java	Tue Jul 21 18:02:36 2015 +0800
@@ -28,6 +28,10 @@
 import java.io.*;
 import java.lang.reflect.Method;
 import java.security.SecureRandom;
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
+import java.time.temporal.TemporalAmount;
+import java.time.temporal.TemporalUnit;
 import java.util.*;
 import java.util.concurrent.*;
 
@@ -939,6 +943,13 @@
             } else if (till.isZero()) {
                 till = new KerberosTime(
                         new Date().getTime() + 1000 * DEFAULT_LIFETIME);
+            } else if (till.greaterThan(new KerberosTime(Instant.now()
+                    .plus(1, ChronoUnit.DAYS)))) {
+                // If till is more than 1 day later, make it renewable
+                till = new KerberosTime(
+                        new Date().getTime() + 1000 * DEFAULT_LIFETIME);
+                body.kdcOptions.set(KDCOptions.RENEWABLE, true);
+                if (rtime == null) rtime = till;
             }
             if (rtime == null && body.kdcOptions.get(KDCOptions.RENEWABLE)) {
                 rtime = new KerberosTime(

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/sun/security/krb5/auto/LongLife.java	Tue Jul 21 18:02:36 2015 +0800
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2015, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8131051
+ * @summary KDC might issue a renewable ticket even if not requested
+ * @compile -XDignore.symbol.file LongLife.java
+ * @run main/othervm LongLife
+ */
+
+import sun.security.krb5.Config;
+
+public class LongLife {
+
+    public static void main(String[] args) throws Exception {
+
+        OneKDC kdc = new OneKDC(null).writeJAASConf();
+
+        // A lifetime 2d will make it renewable
+        KDC.saveConfig(OneKDC.KRB5_CONF, kdc,
+                "ticket_lifetime = 2d");
+        Config.refresh();
+
+        Context.fromJAAS("client");
+    }
+}

--- a/jdk/test/sun/security/krb5/auto/OneKDC.java	Tue Jul 21 14:18:07 2015 -0700
+++ b/jdk/test/sun/security/krb5/auto/OneKDC.java	Tue Jul 21 18:02:36 2015 +0800
@@ -95,7 +95,7 @@
      * entries with names using existing OneKDC principals.
      * @throws java.lang.Exception if anything goes wrong
      */
-    public void writeJAASConf() throws IOException {
+    public OneKDC writeJAASConf() throws IOException {
         System.setProperty("java.security.auth.login.config", JAAS_CONF);
         File f = new File(JAAS_CONF);
         FileOutputStream fos = new FileOutputStream(f);
@@ -123,6 +123,7 @@
                 "    isInitiator=false;\n};\n"
                 ).getBytes());
         fos.close();
+        return this;
     }
 
     /**