| /* |
| * Copyright (c) 2008, 2009, 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 sun.jkernel; |
| |
| import java.io.FilterOutputStream; |
| import java.io.OutputStream; |
| import java.io.IOException; |
| import java.security.NoSuchAlgorithmException; |
| import sun.jkernel.StandaloneMessageDigest; |
| |
| |
| /* |
| * This class provides the main functionality of <code>FilterOutputStream</code>, |
| * and accumulates a check value as bytes are written to |
| * it. The check value is available by method <code>getCheckValue</code>. |
| *<p> |
| * Operations on the public <code>out</code> field of this class should be |
| * avoided to prevent an invalid check code being generated. |
| * |
| * TODO: The javadoc HTML hasn't been generated and eyeballed for yet. |
| * TODO: There is a javadoc trick to cause the parent class javadoc to be |
| * automagically used: try to take advantage of this. |
| * TODO: Add javadoc links instead of <code>API</code> where it would be useful. |
| * TODO: Go visit the Docs style guide again and get the periods right and |
| * consistent for all sun.* classes. |
| * @author Pete Soper |
| * @see java.lang.FilterOutputStream |
| * @see getCheckValue |
| */ |
| |
| public class DigestOutputStream extends FilterOutputStream { |
| private static final String DEFAULT_ALGORITHM = "SHA-1"; |
| |
| private final boolean debug = false; |
| |
| private StandaloneMessageDigest smd = null; |
| |
| private void initDigest(String algorithm) throws NoSuchAlgorithmException { |
| smd = StandaloneMessageDigest.getInstance(algorithm); |
| } |
| |
| // The underlying stream. |
| |
| protected volatile OutputStream out; |
| |
| /** |
| * Creates a <code>DigestOutputStream</code> with stream <code>s</code> |
| * to be checked with using <code>algorithm</code>. |
| * <p> |
| * If <code>algorithm</code> is not supported then |
| * <code>NoSuchAlgorithm</code> is thrown. |
| * <p> |
| * See {linkplain sun.security.provider.StandaloneMessageDigest} for an |
| * implementation-specific list of supported algorithms. |
| * |
| * @throws NoSuchAlgorithm if <code>algorithm</code> is not supported |
| * @see sun.security.provider.StandaloneMessageDigest |
| */ |
| |
| /** |
| * Creates an output stream filter built on top of |
| * underlying output stream <code>out</code> for checking with |
| * algorithm <code>algorithm</code>. |
| * <p> |
| * If <code>algorithm</code> is not supported then |
| * <code>NoSuchAlgorithm</code> is thrown. |
| * <p> |
| * See {linkplain sun.security.provider.StandaloneMessageDigest} for an |
| * implementation-specific list of supported algorithms. |
| * |
| * @param out the underlying output stream to be assigned to |
| * the field <tt>this.out</tt> for later use, or |
| * <code>null</code> if this instance is to be |
| * created without an underlying stream. |
| * @param algorithm the check algorithm to use. |
| * @throws NoSuchAlgorithm if <code>algorithm</code> is not supported |
| * @see sun.security.provider.StandaloneMessageDigest |
| * @see DigestInputStream(InputStream, String) |
| */ |
| |
| public DigestOutputStream(OutputStream out, String algorithm) throws NoSuchAlgorithmException { |
| super(out); |
| initDigest(algorithm); |
| this.out = out; |
| } |
| |
| /** |
| * Creates an output stream filter built on top of |
| * underlying output stream <code>out</code> for the default checking |
| * algorithm. |
| * <p> |
| * This implemention provides "SHA-1" as the default checking algorithm. |
| * |
| * @param out the underlying output stream to be assigned to |
| * the field <tt>this.out</tt> for later use, or |
| * <code>null</code> if this instance is to be |
| * created without an underlying stream. |
| * @see DigestInputStream(InputStream) |
| */ |
| |
| public DigestOutputStream(OutputStream out) { |
| super(out); |
| try { |
| initDigest(DEFAULT_ALGORITHM); |
| } catch (NoSuchAlgorithmException e) { |
| // Impossible to get here, but stranger things have happened... |
| throw new RuntimeException("DigestOutputStream() unknown algorithm"); |
| } |
| // superstition from a test failure this.out = out; |
| } |
| |
| /** |
| * Writes a byte specified by <code>v</code> to this stream |
| * and updates the check information. |
| * |
| * |
| * @param v the byte to be written. |
| * @throws IOException if an I/O error occurs. |
| */ |
| public void write(int v) throws IOException { |
| super.write(v); |
| // TODO Could create this array once |
| byte[] b = new byte[] {(byte) (v & 0xff)}; |
| smd.update(b,0,1); |
| } |
| |
| /** |
| * Writes the bytes in array <code>data</code> |
| * to this stream and updates the check information. |
| * |
| * @param data the data. |
| * @throws IOException if an I/O error occurs. |
| * @throws NullPointerException if <code>data</code> is <code>null</code> |
| */ |
| public void write(byte[] data) throws IOException { |
| write(data,0,data.length); |
| } |
| |
| /** |
| * Writes a sub array as a sequence of bytes to this output stream and |
| * updates the check information. |
| * @param data the data to be written |
| * @param ofs the start offset in the data |
| * @param len the number of bytes that are written |
| * @throws IOException If an I/O error has occurred. |
| * @throws NullPointerException if <code>data</code> is <code>null</code> |
| * @throws IndexOutOfBoundsException If <code>ofs</code> is negative, |
| * <code>len</code> is negative, or <code>len</code> is greater than |
| * <code>b.length - ofs</code> |
| */ |
| public void write(byte[] data, int ofs, int len) throws IOException { |
| if (debug) { |
| System.out.print("DigestOutputStream.write: "); |
| for (int i=ofs; i<(len - ofs); i++) { |
| System.out.format("%02X",data[i]); |
| } |
| System.out.println(); |
| } |
| if (data == null) { |
| throw new NullPointerException("null array in DigestOutputStream.write"); |
| } else if (ofs < 0 || len < 0 || len > data.length - ofs) { |
| throw new IndexOutOfBoundsException(); |
| } |
| //super.write(data,ofs,len); |
| // WATCH OUT: FilterOutputStream does a byte at a time write(byte) |
| // TODO: Will this work all the time, or is there another caveat |
| // to publish |
| out.write(data,ofs,len); |
| if (debug) { |
| System.out.println("DigestOutputStream.write before"); |
| } |
| smd.update(data,ofs,len); |
| if (debug) { |
| System.out.println("DigestOutputStream.write after"); |
| } |
| } |
| |
| /** |
| * Closes this file output stream and releases any system resources |
| * associated with this stream and makes the check value for the stream |
| * available via <code>getCheckValue</code>. This file output stream may |
| * no longer be used for writing bytes. |
| * |
| * @throws IOException if an I/O error occurs. |
| * @see getCheckValue |
| */ |
| public void close() throws IOException { |
| super.close(); |
| } |
| |
| /** |
| * Return the check value computed for the stream and reset the state of |
| * check value generation. |
| * |
| * @return the check value bytes |
| */ |
| public byte[] getCheckValue() { |
| byte[] b = smd.digest(); |
| if (debug) { |
| System.out.print("DigestOutputStream.getCheckValue: "); |
| for (int i=0; i<b.length; i++) { |
| System.out.format("%02X",b[i]); |
| } |
| System.out.println(); |
| } |
| smd.reset(); |
| return b; |
| } |
| |
| /** |
| * Flushes this output stream. |
| * |
| * @throws IOException if an I/O error occurs. |
| * @see java.io.FilterOutputStream#flush() |
| */ |
| public void flush() throws IOException { |
| super.flush(); |
| } |
| |
| /** |
| * Compares two digests for equality. Does a simple byte compare. |
| * |
| * @param digesta one of the digests to compare. |
| * |
| * @param digestb the other digest to compare. |
| * |
| * @return true if the digests are equal, false otherwise. |
| */ |
| // public static boolean isEqual(byte digesta[], byte digestb[]) { |
| // return StandaloneMessageDigest.isEqual(digesta, digestb); |
| // } |
| |
| } |