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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2015 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * 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.wildfly.security.digest;

import java.security.DigestException;
import java.security.MessageDigest;
import java.util.Arrays;

import org.wildfly.common.Assert;

/**
 * A message digest that truncates another message digest.
 *
 * @author David M. Lloyd
 */
public final class TruncatedMessageDigest extends MessageDigest {

    private final MessageDigest delegate;
    private final int bytes;

    /**
     * Construct a new instance.
     *
     * @param delegate the delegate message digest
     * @param bytes the truncation size
     */
    public TruncatedMessageDigest(final MessageDigest delegate, final int bytes) {
        super(delegate.getAlgorithm());
        this.delegate = delegate;
        this.bytes = bytes;
    }

    @Override
    public void update(final byte input) {
        delegate.update(input);
    }

    @Override
    public void update(final byte[] input, final int offset, final int len) {
        delegate.update(input, offset, len);
    }

    @Override
    public void update(final byte[] input) {
        delegate.update(input);
    }

    @Override
    public byte[] digest() {
        final byte[] digest = delegate.digest();
        return digest.length > bytes ? Arrays.copyOf(digest, bytes) : digest;
    }

    @Override
    public int digest(final byte[] buf, final int offset, final int len) throws DigestException {
        Assert.checkNotNullParam("buf", buf);
        if (bytes > len) {
            // exactly match the JDK message
            throw new IllegalArgumentException("Output buffer too small for specified offset and length");
        }
        System.arraycopy(delegate.digest(), 0, buf, offset, bytes);
        return bytes;
    }

    @Override
    public byte[] digest(final byte[] input) {
        update(input);
        return digest();
    }

    @Override
    public void reset() {
        delegate.reset();
    }

    @Override
    public Object clone() throws CloneNotSupportedException {
        return new TruncatedMessageDigest((MessageDigest) delegate.clone(), bytes);
    }

    @Override
    protected void engineUpdate(final byte input) {
    }

    @Override
    protected void engineUpdate(final byte[] input, final int offset, final int len) {
    }

    @Override
    protected byte[] engineDigest() {
        return null;
    }

    @Override
    protected void engineReset() {
    }
}