| /* |
| * Copyright (c) 2011, 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. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * 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. |
| */ |
| |
| package javax.security.auth.kerberos; |
| |
| import java.io.File; |
| import java.util.Objects; |
| import sun.misc.SharedSecrets; |
| import sun.security.krb5.EncryptionKey; |
| import sun.security.krb5.PrincipalName; |
| import sun.security.krb5.RealmException; |
| |
| /** |
| * This class encapsulates a keytab file. |
| * <p> |
| * A Kerberos JAAS login module that obtains long term secret keys from a |
| * keytab file should use this class. The login module will store |
| * an instance of this class in the private credential set of a |
| * {@link javax.security.auth.Subject Subject} during the commit phase of the |
| * authentication process. |
| * <p> |
| * It might be necessary for the application to be granted a |
| * {@link javax.security.auth.PrivateCredentialPermission |
| * PrivateCredentialPermission} if it needs to access the KeyTab |
| * instance from a Subject. This permission is not needed when the |
| * application depends on the default JGSS Kerberos mechanism to access the |
| * KeyTab. In that case, however, the application will need an appropriate |
| * {@link javax.security.auth.kerberos.ServicePermission ServicePermission}. |
| * <p> |
| * The keytab file format is described at |
| * <a href="http://www.ioplex.com/utilities/keytab.txt"> |
| * http://www.ioplex.com/utilities/keytab.txt</a>. |
| * |
| * @since 1.7 |
| */ |
| public final class KeyTab { |
| |
| /* |
| * Impl notes: |
| * |
| * This class is only a name, a permanent link to the keytab source |
| * (can be missing). Itself has no content. In order to read content, |
| * take a snapshot and read from it. |
| * |
| * The snapshot is of type sun.security.krb5.internal.ktab.KeyTab, which |
| * contains the content of the keytab file when the snapshot is taken. |
| * Itself has no refresh function and mostly an immutable class (except |
| * for the create/add/save methods only used by the ktab command). |
| */ |
| |
| // Source, null if using the default one. Note that the default name |
| // is maintained in snapshot, this field is never "resolved". |
| private final File file; |
| |
| // Set up JavaxSecurityAuthKerberosAccess in SharedSecrets |
| static { |
| SharedSecrets.setJavaxSecurityAuthKerberosAccess( |
| new JavaxSecurityAuthKerberosAccessImpl()); |
| } |
| |
| private KeyTab(File file) { |
| this.file = file; |
| } |
| |
| /** |
| * Returns a {@code KeyTab} instance from a {@code File} object. |
| * <p> |
| * The result of this method is never null. This method only associates |
| * the returned {@code KeyTab} object with the file and does not read it. |
| * @param file the keytab {@code File} object, must not be null |
| * @return the keytab instance |
| * @throws NullPointerException if the {@code file} argument is null |
| */ |
| public static KeyTab getInstance(File file) { |
| if (file == null) { |
| throw new NullPointerException("file must be non null"); |
| } |
| return new KeyTab(file); |
| } |
| |
| /** |
| * Returns the default {@code KeyTab} instance. |
| * <p> |
| * The result of this method is never null. This method only associates |
| * the returned {@code KeyTab} object with the default keytab file and |
| * does not read it. |
| * @return the default keytab instance. |
| */ |
| public static KeyTab getInstance() { |
| return new KeyTab(null); |
| } |
| |
| //Takes a snapshot of the keytab content |
| private sun.security.krb5.internal.ktab.KeyTab takeSnapshot() { |
| return sun.security.krb5.internal.ktab.KeyTab.getInstance(file); |
| } |
| |
| /** |
| * Returns fresh keys for the given Kerberos principal. |
| * <p> |
| * Implementation of this method should make sure the returned keys match |
| * the latest content of the keytab file. The result is a newly created |
| * copy that can be modified by the caller without modifying the keytab |
| * object. The caller should {@link KerberosKey#destroy() destroy} the |
| * result keys after they are used. |
| * <p> |
| * Please note that the keytab file can be created after the |
| * {@code KeyTab} object is instantiated and its content may change over |
| * time. Therefore, an application should call this method only when it |
| * needs to use the keys. Any previous result from an earlier invocation |
| * could potentially be expired. |
| * <p> |
| * If there is any error (say, I/O error or format error) |
| * during the reading process of the KeyTab file, a saved result should be |
| * returned. If there is no saved result (say, this is the first time this |
| * method is called, or, all previous read attempts failed), an empty array |
| * should be returned. This can make sure the result is not drastically |
| * changed during the (probably slow) update of the keytab file. |
| * <p> |
| * Each time this method is called and the reading of the file succeeds |
| * with no exception (say, I/O error or file format error), |
| * the result should be saved for {@code principal}. The implementation can |
| * also save keys for other principals having keys in the same keytab object |
| * if convenient. |
| * <p> |
| * Any unsupported key read from the keytab is ignored and not included |
| * in the result. |
| * |
| * @param principal the Kerberos principal, must not be null. |
| * @return the keys (never null, may be empty) |
| * @throws NullPointerException if the {@code principal} |
| * argument is null |
| * @throws SecurityException if a security manager exists and the read |
| * access to the keytab file is not permitted |
| */ |
| public KerberosKey[] getKeys(KerberosPrincipal principal) { |
| try { |
| EncryptionKey[] keys = takeSnapshot().readServiceKeys( |
| new PrincipalName(principal.getName())); |
| KerberosKey[] kks = new KerberosKey[keys.length]; |
| for (int i=0; i<kks.length; i++) { |
| Integer tmp = keys[i].getKeyVersionNumber(); |
| kks[i] = new KerberosKey( |
| principal, |
| keys[i].getBytes(), |
| keys[i].getEType(), |
| tmp == null ? 0 : tmp.intValue()); |
| keys[i].destroy(); |
| } |
| return kks; |
| } catch (RealmException re) { |
| return new KerberosKey[0]; |
| } |
| } |
| |
| EncryptionKey[] getEncryptionKeys(PrincipalName principal) { |
| return takeSnapshot().readServiceKeys(principal); |
| } |
| |
| /** |
| * Checks if the keytab file exists. Implementation of this method |
| * should make sure that the result matches the latest status of the |
| * keytab file. |
| * <p> |
| * The caller can use the result to determine if it should fallback to |
| * another mechanism to read the keys. |
| * @return true if the keytab file exists; false otherwise. |
| * @throws SecurityException if a security manager exists and the read |
| * access to the keytab file is not permitted |
| */ |
| public boolean exists() { |
| return !takeSnapshot().isMissing(); |
| } |
| |
| public String toString() { |
| return file == null ? "Default keytab" : file.toString(); |
| } |
| |
| /** |
| * Returns a hashcode for this KeyTab. |
| * |
| * @return a hashCode() for the <code>KeyTab</code> |
| */ |
| public int hashCode() { |
| return Objects.hash(file); |
| } |
| |
| /** |
| * Compares the specified Object with this KeyTab for equality. |
| * Returns true if the given object is also a |
| * <code>KeyTab</code> and the two |
| * <code>KeyTab</code> instances are equivalent. |
| * |
| * @param other the Object to compare to |
| * @return true if the specified object is equal to this KeyTab |
| */ |
| public boolean equals(Object other) { |
| if (other == this) |
| return true; |
| |
| if (! (other instanceof KeyTab)) { |
| return false; |
| } |
| |
| KeyTab otherKtab = (KeyTab) other; |
| return Objects.equals(otherKtab.file, file); |
| } |
| } |
