mirror of git://gcc.gnu.org/git/gcc.git
124 lines
3.7 KiB
Java
124 lines
3.7 KiB
Java
/* MacOutputStream.java --
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Copyright (C) 2003, 2006 Free Software Foundation, Inc.
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This file is a part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or (at
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your option) any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
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USA
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Linking this library statically or dynamically with other modules is
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making a combined work based on this library. Thus, the terms and
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conditions of the GNU General Public License cover the whole
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combination.
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As a special exception, the copyright holders of this library give you
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permission to link this library with independent modules to produce an
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executable, regardless of the license terms of these independent
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modules, and to copy and distribute the resulting executable under
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terms of your choice, provided that you also meet, for each linked
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independent module, the terms and conditions of the license of that
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module. An independent module is a module which is not derived from
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or based on this library. If you modify this library, you may extend
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this exception to your version of the library, but you are not
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obligated to do so. If you do not wish to do so, delete this
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exception statement from your version. */
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package gnu.javax.crypto.mac;
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import java.io.FilterOutputStream;
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import java.io.IOException;
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import java.io.OutputStream;
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/**
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* A filtering output stream that computes a MAC (message authentication code)
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* over all data written to the stream.
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*/
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public class MacOutputStream
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extends FilterOutputStream
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{
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/** The digesting state. The MAC is updated only if this flag is true. */
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private boolean digesting;
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/** The MAC being updated. */
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private IMac mac;
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/**
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* Creates a new <code>MacOutputStream</code>. The stream is initially set
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* to digest data written, the <code>mac</code> argument must have already
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* been initialized, and the <code>mac</code> argument is <b>not</b>
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* cloned.
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*
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* @param out The underlying output stream.
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* @param mac The mac instance to use.
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*/
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public MacOutputStream(OutputStream out, IMac mac)
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{
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super(out);
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if (mac == null)
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throw new NullPointerException();
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this.mac = mac;
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digesting = true;
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}
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/**
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* Returns the MAC this stream is updating.
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*
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* @return The MAC.
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*/
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public IMac getMac()
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{
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return mac;
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}
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/**
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* Sets the MAC this stream is updating, which must have already been
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* initialized. The argument is not cloned by this method.
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*
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* @param mac The non-null new MAC.
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* @throws NullPointerException If the argument is null.
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*/
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public void setMac(IMac mac)
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{
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if (mac == null)
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throw new NullPointerException();
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this.mac = mac;
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}
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/**
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* Turns the digesting state on or off. When off, the MAC will not be updated
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* when data is written to the stream.
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*
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* @param flag The new digesting state.
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*/
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public void on(boolean flag)
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{
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digesting = flag;
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}
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public void write(int b) throws IOException
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{
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if (digesting)
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mac.update((byte) b);
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out.write(b);
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}
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public void write(byte[] buf, int off, int len) throws IOException
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{
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if (digesting)
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mac.update(buf, off, len);
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out.write(buf, off, len);
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}
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}
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