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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 JDK 1.5 to JDK 1.8. Note: this package includes the NTRU encryption algorithms.

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package org.bouncycastle.crypto.macs;

import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.Mac;
import org.bouncycastle.crypto.digests.SkeinEngine;
import org.bouncycastle.crypto.engines.ThreefishEngine;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.params.SkeinParameters;

/**
 * Implementation of the Skein parameterised MAC function in 256, 512 and 1024 bit block sizes,
 * based on the {@link ThreefishEngine Threefish} tweakable block cipher.
 * 

* This is the 1.3 version of Skein defined in the Skein hash function submission to the NIST SHA-3 * competition in October 2010. *

* Skein was designed by Niels Ferguson - Stefan Lucks - Bruce Schneier - Doug Whiting - Mihir * Bellare - Tadayoshi Kohno - Jon Callas - Jesse Walker. * * @see SkeinEngine * @see SkeinParameters */ public class SkeinMac implements Mac { /** * 256 bit block size - Skein MAC-256 */ public static final int SKEIN_256 = SkeinEngine.SKEIN_256; /** * 512 bit block size - Skein MAC-512 */ public static final int SKEIN_512 = SkeinEngine.SKEIN_512; /** * 1024 bit block size - Skein MAC-1024 */ public static final int SKEIN_1024 = SkeinEngine.SKEIN_1024; private SkeinEngine engine; /** * Constructs a Skein MAC with an internal state size and output size. * * @param stateSizeBits the internal state size in bits - one of {@link #SKEIN_256}, {@link #SKEIN_512} or * {@link #SKEIN_1024}. * @param digestSizeBits the output/MAC size to produce in bits, which must be an integral number of bytes. */ public SkeinMac(int stateSizeBits, int digestSizeBits) { this.engine = new SkeinEngine(stateSizeBits, digestSizeBits); } public SkeinMac(SkeinMac mac) { this.engine = new SkeinEngine(mac.engine); } public String getAlgorithmName() { return "Skein-MAC-" + (engine.getBlockSize() * 8) + "-" + (engine.getOutputSize() * 8); } /** * Initialises the Skein digest with the provided parameters.
* See {@link SkeinParameters} for details on the parameterisation of the Skein hash function. * * @param params an instance of {@link SkeinParameters} or {@link KeyParameter}. */ public void init(CipherParameters params) throws IllegalArgumentException { SkeinParameters skeinParameters; if (params instanceof SkeinParameters) { skeinParameters = (SkeinParameters)params; } else if (params instanceof KeyParameter) { skeinParameters = new SkeinParameters.Builder().setKey(((KeyParameter)params).getKey()).build(); } else { throw new IllegalArgumentException("Invalid parameter passed to Skein MAC init - " + params.getClass().getName()); } if (skeinParameters.getKey() == null) { throw new IllegalArgumentException("Skein MAC requires a key parameter."); } engine.init(skeinParameters); } public int getMacSize() { return engine.getOutputSize(); } public void reset() { engine.reset(); } public void update(byte in) { engine.update(in); } public void update(byte[] in, int inOff, int len) { engine.update(in, inOff, len); } public int doFinal(byte[] out, int outOff) { return engine.doFinal(out, outOff); } }





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