/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/**

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements. See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership. The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License. You may obtain a copy of the License at

 *

 * http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing,

 * software distributed under the License is distributed on an

 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

 * KIND, either express or implied. See the License for the

 * specific language governing permissions and limitations

 * under the License.

 */

/*

 * Copyright (c) 2005, 2018, Oracle and/or its affiliates. All rights reserved.

 */

/*

 * $Id: DigesterOutputStream.java, v 1.5 2005/12/20 20:02:39 mullan Exp $

 */

package org.jcp.xml.dsig.internal;

import java.io.ByteArrayInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.security.MessageDigest;

import com.sun.org.apache.xml.internal.security.utils.UnsyncByteArrayOutputStream;

/**

 * This class has been modified slightly to use java.security.MessageDigest

 * objects as input, rather than

 * com.sun.org.apache.xml.internal.security.algorithms.MessageDigestAlgorithm objects.

 * It also optionally caches the input bytes.

 *

 */

public class DigesterOutputStream extends OutputStream {

    private static final com.sun.org.slf4j.internal.Logger LOG =

        com.sun.org.slf4j.internal.LoggerFactory.getLogger(DigesterOutputStream.class);

    private final boolean buffer;

    private UnsyncByteArrayOutputStream bos;

    private final MessageDigest md;

    /**

     * Creates a DigesterOutputStream.

     *

     * @param md the MessageDigest

     */

    public DigesterOutputStream(MessageDigest md) {

        this(md, false);

    }

    /**

     * Creates a DigesterOutputStream.

     *

     * @param md the MessageDigest

     * @param buffer if true, caches the input bytes

     */

    public DigesterOutputStream(MessageDigest md, boolean buffer) {

        this.md = md;

        this.buffer = buffer;

        if (buffer) {

            bos = new UnsyncByteArrayOutputStream();

        }

    }

    public void write(int input) {

        if (buffer) {

            bos.write(input);

        }

        md.update((byte)input);

    }

    @Override

    public void write(byte[] input, int offset, int len) {

        if (buffer) {

            bos.write(input, offset, len);

        }

        if (LOG.isDebugEnabled()) {

            LOG.debug("Pre-digested input:");

            StringBuilder sb = new StringBuilder(len);

            for (int i = offset; i < (offset + len); i++) {

                sb.append((char)input[i]);

            }

            LOG.debug(sb.toString());

        }

        md.update(input, offset, len);

    }

    /**

     * @return the digest value

     */

    public byte[] getDigestValue() {

         return md.digest();

    }

    /**

     * @return an input stream containing the cached bytes, or

     *    null if not cached

     */

    public InputStream getInputStream() {

        if (buffer) {

            return new ByteArrayInputStream(bos.toByteArray());

        } else {

            return null;

        }

    }

    @Override

    public void close() throws IOException {

        if (buffer) {

            bos.close();

        }

    }

}