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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.cipher;

import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.spec.AlgorithmParameterSpec;

import javax.crypto.spec.IvParameterSpec;

import org.apache.sshd.common.util.buffer.ByteArrayBuffer;

public class BaseCTRCipher extends BaseCipher {

    private long blocksProcessed;

    public BaseCTRCipher(int ivsize, int authSize, int kdfSize, String algorithm, int keySize, String transformation,
                         int blkSize) {
        super(ivsize, authSize, kdfSize, algorithm, keySize, transformation, blkSize);
    }

    @Override
    public void update(byte[] input, int inputOffset, int inputLen) throws Exception {
        blocksProcessed += inputLen / getCipherBlockSize();
        super.update(input, inputOffset, inputLen);
    }

    @Override
    protected void reInit(byte[] processed, int offset, int length)
            throws InvalidKeyException, InvalidAlgorithmParameterException {
        super.reInit(processed, offset, length);
        blocksProcessed = 0;
    }

    @Override
    protected AlgorithmParameterSpec determineNewParameters(byte[] processed, int offset, int length) {
        byte[] iv = getCipherInstance().getIV().clone();
        // Treat the IV as a counter and add blocksProcessed
        ByteArrayBuffer buf = new ByteArrayBuffer(iv, iv.length - Long.BYTES, Long.BYTES);
        long unsigned = buf.getLong();
        long highBitBefore = unsigned & ~Long.MAX_VALUE;
        unsigned &= Long.MAX_VALUE; // Clear most significant bit
        unsigned += blocksProcessed;
        long highBitNow = unsigned & ~Long.MAX_VALUE;
        unsigned = (unsigned & Long.MAX_VALUE) | (highBitBefore ^ highBitNow);
        int carry = (int) ((highBitBefore & highBitNow) >>> (Long.SIZE - 1));
        addCarry(iv, iv.length - Long.BYTES, carry);
        buf.wpos(iv.length - Long.BYTES);
        buf.putLong(unsigned);
        return new IvParameterSpec(iv);
    }

    private void addCarry(byte[] iv, int length, int carry) {
        int add = carry;
        for (int i = length - 1; i >= 0; i--) {
            int b = (iv[i] & 0xFF) + add;
            iv[i] = (byte) b;
            add = b >> Byte.SIZE;
        }
    }
}