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1   /*
2    * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23   * questions.
24   */
25  
26  package javax.crypto;
27  
28  /**
29   * A secret (symmetric) key.
30   * The purpose of this interface is to group (and provide type safety
31   * for) all secret key interfaces.
32   * <p>
33   * Provider implementations of this interface must overwrite the
34   * {@code equals} and {@code hashCode} methods inherited from
35   * {@link java.lang.Object}, so that secret keys are compared based on
36   * their underlying key material and not based on reference.
37   * Implementations should override the default {@code destroy} and
38   * {@code isDestroyed} methods from the
39   * {@link javax.security.auth.Destroyable} interface to enable
40   * sensitive key information to be destroyed, cleared, or in the case
41   * where such information is immutable, unreferenced.
42   * Finally, since {@code SecretKey} is {@code Serializable}, implementations
43   * should also override
44   * {@link java.io.ObjectOutputStream#writeObject(java.lang.Object)}
45   * to prevent keys that have been destroyed from being serialized.
46   *
47   * <p>Keys that implement this interface return the string {@code RAW}
48   * as their encoding format (see {@code getFormat}), and return the
49   * raw key bytes as the result of a {@code getEncoded} method call. (The
50   * {@code getFormat} and {@code getEncoded} methods are inherited
51   * from the {@link java.security.Key} parent interface.)
52   *
53   * @author Jan Luehe
54   *
55   * @see SecretKeyFactory
56   * @see Cipher
57   * @since 1.4
58   */
59  
60  public interface SecretKey extends
61      java.security.Key, javax.security.auth.Destroyable {
62  
63      /**
64       * The class fingerprint that is set to indicate serialization
65       * compatibility since J2SE 1.4.
66       */
67      static final long serialVersionUID = -4795878709595146952L;
68  }