All Downloads are FREE. Search and download functionalities are using the official Maven repository.
Please wait. This can take some minutes ...
Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $
You can buy this project and download/modify it how often you want.
org.bouncycastle.crypto.engines.GOST28147WrapEngine Maven / Gradle / Ivy
package org.bouncycastle.crypto.engines;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.InvalidCipherTextException;
import org.bouncycastle.crypto.Wrapper;
import org.bouncycastle.crypto.macs.GOST28147Mac;
import org.bouncycastle.crypto.params.ParametersWithIV;
import org.bouncycastle.crypto.params.ParametersWithRandom;
import org.bouncycastle.crypto.params.ParametersWithUKM;
import org.bouncycastle.util.Arrays;
public class GOST28147WrapEngine
implements Wrapper
{
private GOST28147Engine cipher = new GOST28147Engine();
private GOST28147Mac mac = new GOST28147Mac();
public void init(boolean forWrapping, CipherParameters param)
{
if (param instanceof ParametersWithRandom)
{
ParametersWithRandom pr = (ParametersWithRandom)param;
param = pr.getParameters();
}
ParametersWithUKM pU = (ParametersWithUKM)param;
cipher.init(forWrapping, pU.getParameters());
mac.init(new ParametersWithIV(pU.getParameters(), pU.getUKM()));
}
public String getAlgorithmName()
{
return "GOST28147Wrap";
}
public byte[] wrap(byte[] input, int inOff, int inLen)
{
mac.update(input, inOff, inLen);
byte[] wrappedKey = new byte[inLen + mac.getMacSize()];
cipher.processBlock(input, inOff, wrappedKey, 0);
cipher.processBlock(input, inOff + 8, wrappedKey, 8);
cipher.processBlock(input, inOff + 16, wrappedKey, 16);
cipher.processBlock(input, inOff + 24, wrappedKey, 24);
mac.doFinal(wrappedKey, inLen);
return wrappedKey;
}
public byte[] unwrap(byte[] input, int inOff, int inLen)
throws InvalidCipherTextException
{
byte[] decKey = new byte[inLen - mac.getMacSize()];
cipher.processBlock(input, inOff, decKey, 0);
cipher.processBlock(input, inOff + 8, decKey, 8);
cipher.processBlock(input, inOff + 16, decKey, 16);
cipher.processBlock(input, inOff + 24, decKey, 24);
byte[] macResult = new byte[mac.getMacSize()];
mac.update(decKey, 0, decKey.length);
mac.doFinal(macResult, 0);
byte[] macExpected = new byte[mac.getMacSize()];
System.arraycopy(input, inOff + inLen - 4, macExpected, 0, mac.getMacSize());
if (!Arrays.constantTimeAreEqual(macResult, macExpected))
{
throw new IllegalStateException("mac mismatch");
}
return decKey;
}
}