| /* |
| * Copyright (c) 1997, 2013, 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.crypto; |
| |
| import java.io.*; |
| |
| /** |
| * A CipherOutputStream is composed of an OutputStream and a Cipher so |
| * that write() methods first process the data before writing them out |
| * to the underlying OutputStream. The cipher must be fully |
| * initialized before being used by a CipherOutputStream. |
| * |
| * <p> For example, if the cipher is initialized for encryption, the |
| * CipherOutputStream will attempt to encrypt data before writing out the |
| * encrypted data. |
| * |
| * <p> This class adheres strictly to the semantics, especially the |
| * failure semantics, of its ancestor classes |
| * java.io.OutputStream and java.io.FilterOutputStream. This class |
| * has exactly those methods specified in its ancestor classes, and |
| * overrides them all. Moreover, this class catches all exceptions |
| * that are not thrown by its ancestor classes. |
| * |
| * <p> It is crucial for a programmer using this class not to use |
| * methods that are not defined or overriden in this class (such as a |
| * new method or constructor that is later added to one of the super |
| * classes), because the design and implementation of those methods |
| * are unlikely to have considered security impact with regard to |
| * CipherOutputStream. |
| * |
| * @author Li Gong |
| * @see java.io.OutputStream |
| * @see java.io.FilterOutputStream |
| * @see javax.crypto.Cipher |
| * @see javax.crypto.CipherInputStream |
| * |
| * @since 1.4 |
| */ |
| |
| public class CipherOutputStream extends FilterOutputStream { |
| |
| // the cipher engine to use to process stream data |
| private Cipher cipher; |
| |
| // the underlying output stream |
| private OutputStream output; |
| |
| /* the buffer holding one byte of incoming data */ |
| private byte[] ibuffer = new byte[1]; |
| |
| // the buffer holding data ready to be written out |
| private byte[] obuffer; |
| |
| // stream status |
| private boolean closed = false; |
| |
| /** |
| * |
| * Constructs a CipherOutputStream from an OutputStream and a |
| * Cipher. |
| * <br>Note: if the specified output stream or cipher is |
| * null, a NullPointerException may be thrown later when |
| * they are used. |
| * |
| * @param os the OutputStream object |
| * @param c an initialized Cipher object |
| */ |
| public CipherOutputStream(OutputStream os, Cipher c) { |
| super(os); |
| output = os; |
| cipher = c; |
| }; |
| |
| /** |
| * Constructs a CipherOutputStream from an OutputStream without |
| * specifying a Cipher. This has the effect of constructing a |
| * CipherOutputStream using a NullCipher. |
| * <br>Note: if the specified output stream is null, a |
| * NullPointerException may be thrown later when it is used. |
| * |
| * @param os the OutputStream object |
| */ |
| protected CipherOutputStream(OutputStream os) { |
| super(os); |
| output = os; |
| cipher = new NullCipher(); |
| } |
| |
| /** |
| * Writes the specified byte to this output stream. |
| * |
| * @param b the <code>byte</code>. |
| * @exception IOException if an I/O error occurs. |
| */ |
| public void write(int b) throws IOException { |
| ibuffer[0] = (byte) b; |
| obuffer = cipher.update(ibuffer, 0, 1); |
| if (obuffer != null) { |
| output.write(obuffer); |
| obuffer = null; |
| } |
| }; |
| |
| /** |
| * Writes <code>b.length</code> bytes from the specified byte array |
| * to this output stream. |
| * <p> |
| * The <code>write</code> method of |
| * <code>CipherOutputStream</code> calls the <code>write</code> |
| * method of three arguments with the three arguments |
| * <code>b</code>, <code>0</code>, and <code>b.length</code>. |
| * |
| * @param b the data. |
| * @exception NullPointerException if <code>b</code> is null. |
| * @exception IOException if an I/O error occurs. |
| * @see javax.crypto.CipherOutputStream#write(byte[], int, int) |
| */ |
| public void write(byte b[]) throws IOException { |
| write(b, 0, b.length); |
| } |
| |
| /** |
| * Writes <code>len</code> bytes from the specified byte array |
| * starting at offset <code>off</code> to this output stream. |
| * |
| * @param b the data. |
| * @param off the start offset in the data. |
| * @param len the number of bytes to write. |
| * @exception IOException if an I/O error occurs. |
| */ |
| public void write(byte b[], int off, int len) throws IOException { |
| obuffer = cipher.update(b, off, len); |
| if (obuffer != null) { |
| output.write(obuffer); |
| obuffer = null; |
| } |
| } |
| |
| /** |
| * Flushes this output stream by forcing any buffered output bytes |
| * that have already been processed by the encapsulated cipher object |
| * to be written out. |
| * |
| * <p>Any bytes buffered by the encapsulated cipher |
| * and waiting to be processed by it will not be written out. For example, |
| * if the encapsulated cipher is a block cipher, and the total number of |
| * bytes written using one of the <code>write</code> methods is less than |
| * the cipher's block size, no bytes will be written out. |
| * |
| * @exception IOException if an I/O error occurs. |
| */ |
| public void flush() throws IOException { |
| if (obuffer != null) { |
| output.write(obuffer); |
| obuffer = null; |
| } |
| output.flush(); |
| } |
| |
| /** |
| * Closes this output stream and releases any system resources |
| * associated with this stream. |
| * <p> |
| * This method invokes the <code>doFinal</code> method of the encapsulated |
| * cipher object, which causes any bytes buffered by the encapsulated |
| * cipher to be processed. The result is written out by calling the |
| * <code>flush</code> method of this output stream. |
| * <p> |
| * This method resets the encapsulated cipher object to its initial state |
| * and calls the <code>close</code> method of the underlying output |
| * stream. |
| * |
| * @exception IOException if an I/O error occurs. |
| */ |
| public void close() throws IOException { |
| if (closed) { |
| return; |
| } |
| |
| closed = true; |
| try { |
| obuffer = cipher.doFinal(); |
| } catch (IllegalBlockSizeException | BadPaddingException e) { |
| obuffer = null; |
| } |
| try { |
| flush(); |
| } catch (IOException ignored) {} |
| out.close(); |
| } |
| } |