8187443: Forest Consolidation: Move files to unified layout

Reviewed-by: darcy, ihse

src/java.base/share/classes/java/security/DigestInputStream.java

@@ -0,0 +1,189 @@
+/*
+ * Copyright (c) 1996, 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 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} 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} 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 original digest untouched.
+ *
+ * @see MessageDigest
+ *
+ * @see DigestOutputStream
+ *
+ * @author Benjamin Renaud
+ * @since 1.2
+ */
+
+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} 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} bytes from the input stream into the array
+     * {@code b}, starting at offset {@code off}. 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}
+     * 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} 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}.
+     *
+     * @return  the actual number of bytes read. This is less than
+     * {@code len} if the end of the stream is reached prior to
+     * reading {@code len} 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} 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();
+     }
+}