--- a/src/share/classes/sun/security/krb5/KrbKdcRep.java	Mon Aug 31 07:09:57 2020 +0100
+++ b/src/share/classes/sun/security/krb5/KrbKdcRep.java	Sun May 31 10:13:04 2020 +0800
@@ -134,12 +134,14 @@
             boolean reqPaReqEncPaRep = false;
             boolean repPaReqEncPaRepValid = false;
 
-            for (PAData pa : req.pAData) {
-                if (pa.getType() == Krb5.PA_REQ_ENC_PA_REP) {
-                    // The KDC supports RFC 6806 and ENC-PA-REP was sent in
-                    // the request (AS-REQ). A valid checksum is now required.
-                    reqPaReqEncPaRep = true;
-                    break;
+            if (req.pAData != null) {
+                for (PAData pa : req.pAData) {
+                    if (pa.getType() == Krb5.PA_REQ_ENC_PA_REP) {
+                        // The KDC supports RFC 6806 and ENC-PA-REP was sent in
+                        // the request (AS-REQ). A valid checksum is now required.
+                        reqPaReqEncPaRep = true;
+                        break;
+                    }
                 }
             }
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/sun/security/krb5/auto/AlwaysEncPaReq.java	Sun May 31 10:13:04 2020 +0800
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2020, 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 8246193
+ * @summary Possible NPE in ENC-PA-REP search in AS-REQ
+ * @library /lib/testlibrary
+ * @compile -XDignore.symbol.file AlwaysEncPaReq.java
+ * @run main/othervm -Dtest.kdc.always.enc.pa.rep
+ *                   -Dsun.net.spi.nameservice.provider.1=ns,mock AlwaysEncPaReq
+ */
+
+public class AlwaysEncPaReq {
+    public static void main(String[] args) throws Exception {
+        new OneKDC(null).writeJAASConf()
+                .setOption(KDC.Option.PREAUTH_REQUIRED, false);
+        Context.fromJAAS("client");
+    }
+}

--- a/test/sun/security/krb5/auto/KDC.java	Mon Aug 31 07:09:57 2020 +0100
+++ b/test/sun/security/krb5/auto/KDC.java	Sun May 31 10:13:04 2020 +0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2020, 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
@@ -1178,6 +1178,9 @@
                 bFlags[Krb5.TKT_OPTS_MAY_POSTDATE] = true;
             }
             bFlags[Krb5.TKT_OPTS_INITIAL] = true;
+            if (System.getProperty("test.kdc.always.enc.pa.rep") != null) {
+                bFlags[Krb5.TKT_OPTS_ENC_PA_REP] = true;
+            }
 
             // Creating PA-DATA
             DerValue[] pas2 = null, pas = null;