--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/security/DigestInputStream.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,188 @@
+/*
+ * Copyright 1996-1999 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.security;
+
+import java.io.IOException;
+import java.io.EOFException;
+import java.io.InputStream;
+import java.io.FilterInputStream;
+import java.io.PrintStream;
+import java.io.ByteArrayInputStream;
+
+/**
+ * A transparent stream that updates the associated message digest using
+ * the bits going through the stream.
+ *
+ * <p>To complete the message digest computation, call one of the
+ * <code>digest</code> methods on the associated message
+ * digest after your calls to one of this digest input stream's
+ * {@link #read() read} methods.
+ *
+ * <p>It is possible to turn this stream on or off (see
+ * {@link #on(boolean) on}). When it is on, a call to one of the
+ * <code>read</code> methods
+ * results in an update on the message digest. But when it is off,
+ * the message digest is not updated. The default is for the stream
+ * to be on.
+ *
+ * <p>Note that digest objects can compute only one digest (see
+ * {@link MessageDigest}),
+ * so that in order to compute intermediate digests, a caller should
+ * retain a handle onto the digest object, and clone it for each
+ * digest to be computed, leaving the orginal digest untouched.
+ *
+ * @see MessageDigest
+ *
+ * @see DigestOutputStream
+ *
+ * @author Benjamin Renaud
+ */
+
+public class DigestInputStream extends FilterInputStream {
+
+ /* NOTE: This should be made a generic UpdaterInputStream */
+
+ /* Are we on or off? */
+ private boolean on = true;
+
+ /**
+ * The message digest associated with this stream.
+ */
+ protected MessageDigest digest;
+
+ /**
+ * Creates a digest input stream, using the specified input stream
+ * and message digest.
+ *
+ * @param stream the input stream.
+ *
+ * @param digest the message digest to associate with this stream.
+ */
+ public DigestInputStream(InputStream stream, MessageDigest digest) {
+ super(stream);
+ setMessageDigest(digest);
+ }
+
+ /**
+ * Returns the message digest associated with this stream.
+ *
+ * @return the message digest associated with this stream.
+ * @see #setMessageDigest(java.security.MessageDigest)
+ */
+ public MessageDigest getMessageDigest() {
+ return digest;
+ }
+
+ /**
+ * Associates the specified message digest with this stream.
+ *
+ * @param digest the message digest to be associated with this stream.
+ * @see #getMessageDigest()
+ */
+ public void setMessageDigest(MessageDigest digest) {
+ this.digest = digest;
+ }
+
+ /**
+ * Reads a byte, and updates the message digest (if the digest
+ * function is on). That is, this method reads a byte from the
+ * input stream, blocking until the byte is actually read. If the
+ * digest function is on (see {@link #on(boolean) on}), this method
+ * will then call <code>update</code> on the message digest associated
+ * with this stream, passing it the byte read.
+ *
+ * @return the byte read.
+ *
+ * @exception IOException if an I/O error occurs.
+ *
+ * @see MessageDigest#update(byte)
+ */
+ public int read() throws IOException {
+ int ch = in.read();
+ if (on && ch != -1) {
+ digest.update((byte)ch);
+ }
+ return ch;
+ }
+
+ /**
+ * Reads into a byte array, and updates the message digest (if the
+ * digest function is on). That is, this method reads up to
+ * <code>len</code> bytes from the input stream into the array
+ * <code>b</code>, starting at offset <code>off</code>. This method
+ * blocks until the data is actually
+ * read. If the digest function is on (see
+ * {@link #on(boolean) on}), this method will then call <code>update</code>
+ * on the message digest associated with this stream, passing it
+ * the data.
+ *
+ * @param b the array into which the data is read.
+ *
+ * @param off the starting offset into <code>b</code> of where the
+ * data should be placed.
+ *
+ * @param len the maximum number of bytes to be read from the input
+ * stream into b, starting at offset <code>off</code>.
+ *
+ * @return the actual number of bytes read. This is less than
+ * <code>len</code> if the end of the stream is reached prior to
+ * reading <code>len</code> bytes. -1 is returned if no bytes were
+ * read because the end of the stream had already been reached when
+ * the call was made.
+ *
+ * @exception IOException if an I/O error occurs.
+ *
+ * @see MessageDigest#update(byte[], int, int)
+ */
+ public int read(byte[] b, int off, int len) throws IOException {
+ int result = in.read(b, off, len);
+ if (on && result != -1) {
+ digest.update(b, off, result);
+ }
+ return result;
+ }
+
+ /**
+ * Turns the digest function on or off. The default is on. When
+ * it is on, a call to one of the <code>read</code> methods results in an
+ * update on the message digest. But when it is off, the message
+ * digest is not updated.
+ *
+ * @param on true to turn the digest function on, false to turn
+ * it off.
+ */
+ public void on(boolean on) {
+ this.on = on;
+ }
+
+ /**
+ * Prints a string representation of this digest input stream and
+ * its associated message digest object.
+ */
+ public String toString() {
+ return "[Digest Input Stream] " + digest.toString();
+ }
+}