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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.mac;

import org.apache.sshd.common.util.NumberUtils;

/**
 * Message Authentication Code for use in SSH. It usually wraps a javax.crypto.Mac class.
 *
 * @author Apache MINA SSHD Project
 */
public interface Mac extends MacInformation {
    void init(byte[] key) throws Exception;

    default void update(byte[] buf) {
        update(buf, 0, NumberUtils.length(buf));
    }

    void update(byte[] buf, int start, int len);

    void updateUInt(long foo);

    default byte[] doFinal() throws Exception {
        int blockSize = getBlockSize();
        byte[] buf = new byte[blockSize];
        doFinal(buf);
        return buf;
    }

    default void doFinal(byte[] buf) throws Exception {
        doFinal(buf, 0);
    }

    void doFinal(byte[] buf, int offset) throws Exception;

    /*
     * Executes a more-or-less constant time verification in order
     * to avoid timing side-channel information leak
     */
    static boolean equals(byte[] a1, int a1Offset, byte[] a2, int a2Offset, int length) {
        int len1 = NumberUtils.length(a1);
        int len2 = NumberUtils.length(a2);
        int result = 0;

        if (len1 < (a1Offset + length)) {
            length = Math.min(length, len1 - a1Offset);
            length = Math.max(length, 0);
            result |= 0x00FF;
        }

        if (len2 < (a2Offset + length)) {
            length = Math.min(length, len2 - a2Offset);
            length = Math.max(length, 0);
            result |= 0xFF00;
        }

        for (int cmpLen = length; cmpLen > 0; a1Offset++, a2Offset++, cmpLen--) {
            result |= a1[a1Offset] ^ a2[a2Offset];
        }

        return result == 0;
    }
}