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Diffstat (limited to 'libjava/classpath/javax/crypto/CipherOutputStream.java')
| -rw-r--r-- | libjava/classpath/javax/crypto/CipherOutputStream.java | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/libjava/classpath/javax/crypto/CipherOutputStream.java b/libjava/classpath/javax/crypto/CipherOutputStream.java new file mode 100644 index 00000000000..adeb6e5ed38 --- /dev/null +++ b/libjava/classpath/javax/crypto/CipherOutputStream.java @@ -0,0 +1,268 @@ +/* CipherOutputStream.java -- Filters output through a cipher. + Copyright (C) 2004 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package javax.crypto; + +import java.io.FilterOutputStream; +import java.io.IOException; +import java.io.OutputStream; + +/** + * A filtered output stream that transforms data written to it with a + * {@link Cipher} before sending it to the underlying output stream. + * + * @author Casey Marshall (csm@gnu.org) + */ +public class CipherOutputStream extends FilterOutputStream +{ + + // Fields. + // ------------------------------------------------------------------------ + + /** The underlying cipher. */ + private Cipher cipher; + + private byte[][] inBuffer; + + private int inLength; + + private byte[] outBuffer; + + private static final int FIRST_TIME = 0; + private static final int SECOND_TIME = 1; + private static final int SEASONED = 2; + private int state; + + /** True if the cipher is a stream cipher (blockSize == 1) */ + private boolean isStream; + + // Constructors. + // ------------------------------------------------------------------------ + + /** + * Create a new cipher output stream. The cipher argument must have + * already been initialized. + * + * @param out The sink for transformed data. + * @param cipher The cipher to transform data with. + */ + public CipherOutputStream(OutputStream out, Cipher cipher) + { + super(out); + if (cipher != null) + { + this.cipher = cipher; + if (!(isStream = cipher.getBlockSize() == 1)) + { + inBuffer = new byte[2][]; + inBuffer[0] = new byte[cipher.getBlockSize()]; + inBuffer[1] = new byte[cipher.getBlockSize()]; + inLength = 0; + state = FIRST_TIME; + } + } + else + this.cipher = new NullCipher(); + } + + /** + * Create a cipher output stream with no cipher. + * + * @param out The sink for transformed data. + */ + protected CipherOutputStream(OutputStream out) + { + super(out); + } + + // Instance methods. + // ------------------------------------------------------------------------ + + /** + * Close this output stream, and the sink output stream. + * + * <p>This method will first invoke the {@link Cipher#doFinal()} + * method of the underlying {@link Cipher}, and writes the output of + * that method to the sink output stream. + * + * @throws java.io.IOException If an I/O error occurs, or if an error + * is caused by finalizing the transformation. + */ + public void close() throws IOException + { + try + { + int len; + if (state != FIRST_TIME) + { + len = cipher.update(inBuffer[0], 0, inBuffer[0].length, outBuffer); + out.write(outBuffer, 0, len); + } + len = cipher.doFinal(inBuffer[0], 0, inLength, outBuffer); + out.write(outBuffer, 0, len); + } + catch (javax.crypto.IllegalBlockSizeException ibse) + { + throw new IOException(ibse.toString()); + } + catch (javax.crypto.BadPaddingException bpe) + { + throw new IOException(bpe.toString()); + } + catch (ShortBufferException sbe) + { + throw new IOException(sbe.toString()); + } + out.flush(); + out.close(); + } + + /** + * Flush any pending output. + * + * @throws java.io.IOException If an I/O error occurs. + */ + public void flush() throws IOException + { + out.flush(); + } + + /** + * Write a single byte to the output stream. + * + * @param b The next byte. + * @throws java.io.IOException If an I/O error occurs, or if the + * underlying cipher is not in the correct state to transform + * data. + */ + public void write(int b) throws IOException + { + if (isStream) + { + byte[] buf = new byte[] { (byte) b }; + try + { + cipher.update(buf, 0, 1, buf, 0); + } + catch (ShortBufferException sbe) + { + throw new IOException(sbe.toString()); + } + out.write(buf); + return; + } + inBuffer[1][inLength++] = (byte) b; + if (inLength == inBuffer[1].length) + process(); + } + + /** + * Write a byte array to the output stream. + * + * @param buf The next bytes. + * @throws java.io.IOException If an I/O error occurs, or if the + * underlying cipher is not in the correct state to transform + * data. + */ + public void write(byte[] buf) throws IOException + { + write(buf, 0, buf.length); + } + + /** + * Write a portion of a byte array to the output stream. + * + * @param buf The next bytes. + * @param off The offset in the byte array to start. + * @param len The number of bytes to write. + * @throws java.io.IOException If an I/O error occurs, or if the + * underlying cipher is not in the correct state to transform + * data. + */ + public void write(byte[] buf, int off, int len) throws IOException + { + if (isStream) + { + out.write(cipher.update(buf, off, len)); + return; + } + int count = 0; + while (count < len) + { + int l = Math.min(inBuffer[1].length - inLength, len - count); + System.arraycopy(buf, off+count, inBuffer[1], inLength, l); + count += l; + inLength += l; + if (inLength == inBuffer[1].length) + process(); + } + } + + // Own method. + // ------------------------------------------------------------------------- + + private void process() throws IOException + { + if (state == SECOND_TIME) + { + state = SEASONED; + } + else + { + byte[] temp = inBuffer[0]; + inBuffer[0] = inBuffer[1]; + inBuffer[1] = temp; + } + if (state == FIRST_TIME) + { + inLength = 0; + state = SECOND_TIME; + return; + } + try + { + cipher.update(inBuffer[0], 0, inBuffer[0].length, outBuffer); + } + catch (ShortBufferException sbe) + { + throw new IOException(sbe.toString()); + } + out.write(outBuffer); + inLength = 0; + } +} |