org.bouncycastle.crypto.engines.DSTU7624WrapEngine Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of bcprov-ext-debug-jdk18on Show documentation
The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for Java 1.8 and later with debug enabled.
The newest version!
package org.bouncycastle.crypto.engines;

import java.util.ArrayList;

import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.DataLengthException;
import org.bouncycastle.crypto.InvalidCipherTextException;
import org.bouncycastle.crypto.Wrapper;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.params.ParametersWithRandom;
import org.bouncycastle.util.Arrays;

/**
 * Implementation of DSTU7624 KEY WRAP mode
 */
public class DSTU7624WrapEngine
    implements Wrapper
{

    private static final int BYTES_IN_INTEGER = 4;

    private boolean forWrapping;
    private DSTU7624Engine engine;

    private byte[] B, intArray;
    private byte[] checkSumArray, zeroArray;
    private ArrayList Btemp;


    public DSTU7624WrapEngine(int blockBitLength)
    {

        this.engine = new DSTU7624Engine(blockBitLength);
        this.B = new byte[engine.getBlockSize() / 2];
        this.checkSumArray = new byte[engine.getBlockSize()];
        this.zeroArray = new byte[engine.getBlockSize()];
        this.Btemp = new ArrayList();
        this.intArray = new byte[BYTES_IN_INTEGER];

    }

    public void init(boolean forWrapping, CipherParameters param)
    {
        if (param instanceof ParametersWithRandom)
        {
            param = ((ParametersWithRandom)param).getParameters();
        }

        this.forWrapping = forWrapping;
        if (param instanceof KeyParameter)
        {
            engine.init(forWrapping, param);
        }
        else
        {
            throw new IllegalArgumentException("invalid parameters passed to DSTU7624WrapEngine");
        }

    }

    public String getAlgorithmName()
    {
        return "DSTU7624WrapEngine";
    }

    public byte[] wrap(byte[] in, int inOff, int inLen)
    {
        if (!forWrapping)
        {
            throw new IllegalStateException("not set for wrapping");
        }

        if ((inLen % engine.getBlockSize()) != 0)
        {
            //Partial blocks not supported
            throw new DataLengthException("wrap data must be a multiple of " + engine.getBlockSize() + " bytes");
        }

        if (inOff + inLen > in.length)
        {
            throw new DataLengthException("input buffer too short");
        }

        int n = 2 * (1 + inLen / engine.getBlockSize()); /* Defined in DSTU7624 standard */
        int V = (n - 1) * 6; /* Defined in DSTU7624 standard */


        byte[] wrappedBuffer = new byte[inLen + engine.getBlockSize()];
        System.arraycopy(in, inOff, wrappedBuffer, 0, inLen);

        System.arraycopy(wrappedBuffer, 0, B, 0, engine.getBlockSize() / 2);

        Btemp.clear();

        int bHalfBlocksLen = wrappedBuffer.length - engine.getBlockSize() / 2;
        int bufOff = engine.getBlockSize() / 2;
        while (bHalfBlocksLen != 0)
        {
            byte[] temp = new byte[engine.getBlockSize() / 2];
            System.arraycopy(wrappedBuffer, bufOff, temp, 0, engine.getBlockSize() / 2);

            Btemp.add(temp);

            bHalfBlocksLen -= engine.getBlockSize() / 2;
            bufOff += engine.getBlockSize() / 2;
        }

        for (int j = 0; j < V; j++)
        {
            System.arraycopy(B, 0, wrappedBuffer, 0, engine.getBlockSize() / 2);
            System.arraycopy(Btemp.get(0), 0, wrappedBuffer, engine.getBlockSize() / 2, engine.getBlockSize() / 2);

            engine.processBlock(wrappedBuffer, 0, wrappedBuffer, 0);

            intToBytes(j + 1, intArray, 0);
            for (int byteNum = 0; byteNum < BYTES_IN_INTEGER; byteNum++)
            {
                wrappedBuffer[byteNum + engine.getBlockSize() / 2] ^= intArray[byteNum];
            }

            System.arraycopy(wrappedBuffer, engine.getBlockSize() / 2, B, 0, engine.getBlockSize() / 2);

            for (int i = 2; i < n; i++)
            {
                System.arraycopy(Btemp.get(i - 1), 0, Btemp.get(i - 2), 0, engine.getBlockSize() / 2);
            }

            System.arraycopy(wrappedBuffer, 0, Btemp.get(n - 2), 0, engine.getBlockSize() / 2);
        }


        System.arraycopy(B, 0, wrappedBuffer, 0, engine.getBlockSize() / 2);
        bufOff = engine.getBlockSize() / 2;

        for (int i = 0; i < n - 1; i++)
        {
            System.arraycopy(Btemp.get(i), 0, wrappedBuffer, bufOff, engine.getBlockSize() / 2);
            bufOff += engine.getBlockSize() / 2;
        }

        return wrappedBuffer;

    }

    public byte[] unwrap(byte[] in, int inOff, int inLen)
        throws InvalidCipherTextException
    {
        if (forWrapping)
        {
            throw new IllegalStateException("not set for unwrapping");
        }

        if ((inLen % engine.getBlockSize()) != 0)
        {
            //Partial blocks not supported
            throw new DataLengthException("unwrap data must be a multiple of " + engine.getBlockSize() + " bytes");
        }

        int n = 2 * inLen / engine.getBlockSize();

        int V = (n - 1) * 6;

        byte[] buffer = new byte[inLen];
        System.arraycopy(in, inOff, buffer, 0, inLen);

        byte[] B = new byte[engine.getBlockSize() / 2];
        System.arraycopy(buffer, 0, B, 0, engine.getBlockSize() / 2);

        Btemp.clear();

        int bHalfBlocksLen = buffer.length - engine.getBlockSize() / 2;
        int bufOff = engine.getBlockSize() / 2;
        while (bHalfBlocksLen != 0)
        {
            byte[] temp = new byte[engine.getBlockSize() / 2];
            System.arraycopy(buffer, bufOff, temp, 0, engine.getBlockSize() / 2);

            Btemp.add(temp);

            bHalfBlocksLen -= engine.getBlockSize() / 2;
            bufOff += engine.getBlockSize() / 2;
        }

        for (int j = 0; j < V; j++)
        {
            System.arraycopy(Btemp.get(n - 2), 0, buffer, 0, engine.getBlockSize() / 2);
            System.arraycopy(B, 0, buffer, engine.getBlockSize() / 2, engine.getBlockSize() / 2);
            intToBytes(V - j, intArray, 0);
            for (int byteNum = 0; byteNum < BYTES_IN_INTEGER; byteNum++)
            {
                buffer[byteNum + engine.getBlockSize() / 2] ^= intArray[byteNum];
            }

            engine.processBlock(buffer, 0, buffer, 0);

            System.arraycopy(buffer, 0, B, 0, engine.getBlockSize() / 2);

            for (int i = 2; i < n; i++)
            {
                System.arraycopy(Btemp.get(n - i - 1), 0, Btemp.get(n - i), 0, engine.getBlockSize() / 2);
            }

            System.arraycopy(buffer, engine.getBlockSize() / 2, Btemp.get(0), 0, engine.getBlockSize() / 2);
        }

        System.arraycopy(B, 0, buffer, 0, engine.getBlockSize() / 2);
        bufOff = engine.getBlockSize() / 2;

        for (int i = 0; i < n - 1; i++)
        {
            System.arraycopy(Btemp.get(i), 0, buffer, bufOff, engine.getBlockSize() / 2);
            bufOff += engine.getBlockSize() / 2;
        }

        System.arraycopy(buffer, buffer.length - engine.getBlockSize(), checkSumArray, 0, engine.getBlockSize());

        byte[] wrappedBuffer = new byte[buffer.length - engine.getBlockSize()];
        if (!Arrays.areEqual(checkSumArray, zeroArray))
        {
            throw new InvalidCipherTextException("checksum failed");
        }
        else
        {
            System.arraycopy(buffer, 0, wrappedBuffer, 0, buffer.length - engine.getBlockSize());
        }


        return wrappedBuffer;
    }


    private void intToBytes(int number, byte[] outBytes, int outOff)
    {
        outBytes[outOff + 3] = (byte)(number >> 24);
        outBytes[outOff + 2] = (byte)(number >> 16);
        outBytes[outOff + 1] = (byte)(number >> 8);
        outBytes[outOff] = (byte)number;
    }
}