1 /* MacOutputStream.java --
2 Copyright (C) 2003, 2006 Free Software Foundation, Inc.
4 This file is a part of GNU Classpath.
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or (at
9 your option) any later version.
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
39 package gnu
.javax
.crypto
.mac
;
41 import java
.io
.FilterOutputStream
;
42 import java
.io
.IOException
;
43 import java
.io
.OutputStream
;
46 * <p>A filtering output stream that computes a MAC (message authentication
47 * code) over all data written to the stream.</p>
49 public class MacOutputStream
extends FilterOutputStream
52 // Constants and variables
53 // -------------------------------------------------------------------------
55 /** The digesting state. The MAC is updated only if this flag is true. */
56 private boolean digesting
;
58 /** The MAC being updated. */
62 // -------------------------------------------------------------------------
65 * <p>Creates a new <code>MacOutputStream</code>. The stream is initially set
66 * to digest data written, the <code>mac</code> argument must have already
67 * been initialized, and the <code>mac</code> argument is <b>not</b> cloned.</p>
69 * @param out The underlying output stream.
70 * @param mac The mac instance to use.
72 public MacOutputStream(OutputStream out
, IMac mac
)
77 throw new NullPointerException();
84 // -------------------------------------------------------------------------
87 * <p>Returns the MAC this stream is updating.</p>
97 * <p>Sets the MAC this stream is updating, which must have already been
98 * initialized. The argument is not cloned by this method.</p>
100 * @param mac The non-null new MAC.
101 * @throws NullPointerException If the argument is null.
103 public void setMac(IMac mac
)
107 throw new NullPointerException();
113 * <p>Turns the digesting state on or off. When off, the MAC will not be
114 * updated when data is written to the stream.</p>
116 * @param flag The new digesting state.
118 public void on(boolean flag
)
123 public void write(int b
) throws IOException
127 mac
.update((byte) b
);
132 public void write(byte[] buf
, int off
, int len
) throws IOException
136 mac
.update(buf
, off
, len
);
138 out
.write(buf
, off
, len
);