8274205: Handle KDC_ERR_SVC_UNAVAILABLE error code from KDC

Backport-of: 5ba0d09fe47439880daf913f4ff0b978ed9c1ac6

src/java.security.jgss/share/classes/sun/security/krb5/KdcComm.java

@@ -256,9 +256,14 @@ private byte[] sendIfPossible(byte[] obuf, String tempKdc, boolean useTCP)
             } catch (Exception e) {
                 // OK
             }
-            if (ke != null && ke.getErrorCode() ==
+            if (ke != null) {
+                if (ke.getErrorCode() ==
                     Krb5.KRB_ERR_RESPONSE_TOO_BIG) {
-                ibuf = send(obuf, tempKdc, true);
+                    ibuf = send(obuf, tempKdc, true);
+                } else if (ke.getErrorCode() ==
+                        Krb5.KDC_ERR_SVC_UNAVAILABLE) {
+                    throw new KrbException("A service is not available");
+                }
             }
             KdcAccessibility.removeBad(tempKdc);
             return ibuf;

src/java.security.jgss/share/classes/sun/security/krb5/internal/Krb5.java

@@ -250,6 +250,7 @@ public class Krb5 {
     public static final int KDC_ERR_KEY_EXPIRED          = 23;   //Password has expired - change password to reset
     public static final int KDC_ERR_PREAUTH_FAILED       = 24;   //Pre-authentication information was invalid
     public static final int KDC_ERR_PREAUTH_REQUIRED     = 25;   //Additional pre-authentication required
+    public static final int KDC_ERR_SVC_UNAVAILABLE      = 29;   //A service is not available
     public static final int KRB_AP_ERR_BAD_INTEGRITY     = 31;   //Integrity check on decrypted field failed
     public static final int KRB_AP_ERR_TKT_EXPIRED       = 32;   //Ticket expired
     public static final int KRB_AP_ERR_TKT_NYV           = 33;   //Ticket not yet valid

test/jdk/sun/security/krb5/auto/Unavailable.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2021, 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 8274205
+ * @summary Handle KDC_ERR_SVC_UNAVAILABLE error code from KDC
+ * @library /test/lib
+ * @compile -XDignore.symbol.file Unavailable.java
+ * @run main jdk.test.lib.FileInstaller TestHosts TestHosts
+ * @run main/othervm -Djdk.net.hosts.file=TestHosts Unavailable
+ */
+
+import sun.security.krb5.Config;
+import sun.security.krb5.PrincipalName;
+import sun.security.krb5.internal.KRBError;
+import sun.security.krb5.internal.KerberosTime;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Locale;
+
+public class Unavailable {
+
+    public static void main(String[] args) throws Exception {
+
+        // Good KDC
+        KDC kdc1 = KDC.create(OneKDC.REALM);
+        kdc1.addPrincipal(OneKDC.USER, OneKDC.PASS);
+        kdc1.addPrincipalRandKey("krbtgt/" + OneKDC.REALM);
+
+        // The "not available" KDC
+        KDC kdc2 = new KDC(OneKDC.REALM, "kdc." + OneKDC.REALM.toLowerCase(Locale.US), 0, true) {
+            @Override
+            protected byte[] processAsReq(byte[] in) throws Exception {
+                KRBError err = new KRBError(null, null, null,
+                        KerberosTime.now(), 0,
+                        29, // KDC_ERR_SVC_UNAVAILABLE
+                        null, new PrincipalName("krbtgt/" + OneKDC.REALM),
+                        null, null);
+                return err.asn1Encode();
+            }
+        };
+
+        Files.write(Path.of(OneKDC.KRB5_CONF), String.format("""
+                [libdefaults]
+                default_realm = RABBIT.HOLE
+
+                [realms]
+                RABBIT.HOLE = {
+                    kdc = kdc.rabbit.hole:%d
+                    kdc = kdc.rabbit.hole:%d
+                }
+                """, kdc2.getPort(), kdc1.getPort()).getBytes());
+        System.setProperty("java.security.krb5.conf", OneKDC.KRB5_CONF);
+        Config.refresh();
+
+        Context.fromUserPass(OneKDC.USER, OneKDC.PASS, false);
+    }
+}