/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * Copyright 1999-2005 The Apache Software Foundation.

 *

 *  Licensed 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.

 *

 */

/*

 */

package org.jcp.xml.dsig.internal;

import java.io.ByteArrayInputStream;

import java.io.InputStream;

import java.io.OutputStream;

import java.security.MessageDigest;

import java.util.logging.Logger;

import java.util.logging.Level;

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

 * It also optionally caches the input bytes.

 *

 * @author raul

 */

public class DigesterOutputStream extends OutputStream {

    private boolean buffer = false;

    private UnsyncByteArrayOutputStream bos;

    private final MessageDigest md;

    private static Logger log = Logger.getLogger("org.jcp.xml.dsig.internal");

    /**

     * 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();

        }

    }

    /** @inheritDoc */

    public void write(byte[] input) {

        write(input, 0, input.length);

    }

    /** @inheritDoc */

    public void write(int input) {

        if (buffer) {

            bos.write(input);

        }

        md.update((byte)input);

    }

    /** @inheritDoc */

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

        if (buffer) {

            bos.write(input, offset, len);

        }

        if (log.isLoggable(Level.FINER)) {

            log.log(Level.FINER, "Pre-digested input:");

            StringBuffer sb = new StringBuffer(len);

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

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

            }

            log.log(Level.FINER, 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;

        }

    }

}