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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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/*
 * 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.
 */
package org.apache.sshd.common.digest;

import java.security.MessageDigest;
import java.util.Objects;

import org.apache.sshd.common.util.GenericUtils;
import org.apache.sshd.common.util.NumberUtils;
import org.apache.sshd.common.util.ValidateUtils;
import org.apache.sshd.common.util.security.SecurityUtils;

/**
 * Base class for Digest algorithms based on the JCE provider.
 *
 * @author Apache MINA SSHD Project
 */
public class BaseDigest implements Digest {

    private final String algorithm;
    private final int bsize;
    private int h;
    private String s;
    private MessageDigest md;

    /**
     * Create a new digest using the given algorithm and block size. The initialization and creation of the underlying
     * {@link MessageDigest} object will be done in the {@link #init()} method.
     *
     * @param algorithm the JCE algorithm to use for this digest
     * @param bsize     the block size of this digest
     */
    public BaseDigest(String algorithm, int bsize) {
        this.algorithm = ValidateUtils.checkNotNullAndNotEmpty(algorithm, "No algorithm");
        ValidateUtils.checkTrue(bsize > 0, "Invalid block size: %d", bsize);
        this.bsize = bsize;
    }

    @Override
    public final String getAlgorithm() {
        return algorithm;
    }

    @Override
    public int getBlockSize() {
        return bsize;
    }

    @Override
    public void init() throws Exception {
        this.md = SecurityUtils.getMessageDigest(getAlgorithm());
    }

    @Override
    public void update(byte[] data) throws Exception {
        update(data, 0, NumberUtils.length(data));
    }

    @Override
    public void update(byte[] data, int start, int len) throws Exception {
        Objects.requireNonNull(md, "Digest not initialized").update(data, start, len);
    }

    /**
     * @return The current {@link MessageDigest} - may be {@code null} if {@link #init()} not called
     */
    protected MessageDigest getMessageDigest() {
        return md;
    }

    @Override
    public byte[] digest() throws Exception {
        return Objects.requireNonNull(md, "Digest not initialized").digest();
    }

    @Override
    public int hashCode() {
        synchronized (this) {
            if (h == 0) {
                h = Objects.hashCode(getAlgorithm()) + getBlockSize();
                if (h == 0) {
                    h = 1;
                }
            }
        }

        return h;
    }

    @Override
    public int compareTo(Digest that) {
        if (that == null) {
            return -1; // push null(s) to end
        } else if (this == that) {
            return 0;
        }

        String thisAlg = getAlgorithm();
        String thatAlg = that.getAlgorithm();
        int nRes = GenericUtils.safeCompare(thisAlg, thatAlg, false);
        if (nRes != 0) {
            return nRes; // debug breakpoint
        }

        nRes = Integer.compare(this.getBlockSize(), that.getBlockSize());
        if (nRes != 0) {
            return nRes; // debug breakpoint
        }

        return 0;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == null) {
            return false;
        }
        if (obj == this) {
            return true;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }

        int nRes = compareTo((Digest) obj);
        return nRes == 0;
    }

    @Override
    public String toString() {
        synchronized (this) {
            if (s == null) {
                s = getClass().getSimpleName() + "[" + getAlgorithm() + ":" + getBlockSize() + "]";
            }
        }

        return s;
    }
}