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Diffstat (limited to 'core/src/main/java/org/spongycastle/crypto/digests/SkeinDigest.java')
-rw-r--r-- | core/src/main/java/org/spongycastle/crypto/digests/SkeinDigest.java | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/crypto/digests/SkeinDigest.java b/core/src/main/java/org/spongycastle/crypto/digests/SkeinDigest.java new file mode 100644 index 00000000..d476170f --- /dev/null +++ b/core/src/main/java/org/spongycastle/crypto/digests/SkeinDigest.java @@ -0,0 +1,115 @@ +package org.spongycastle.crypto.digests; + +import org.spongycastle.crypto.ExtendedDigest; +import org.spongycastle.crypto.engines.ThreefishEngine; +import org.spongycastle.crypto.params.SkeinParameters; +import org.spongycastle.util.Memoable; + +/** + * Implementation of the Skein parameterised hash function in 256, 512 and 1024 bit block sizes, + * based on the {@link ThreefishEngine Threefish} tweakable block cipher. + * <p> + * This is the 1.3 version of Skein defined in the Skein hash function submission to the NIST SHA-3 + * competition in October 2010. + * <p> + * 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 SkeinDigest + implements ExtendedDigest, Memoable +{ + /** + * 256 bit block size - Skein-256 + */ + public static final int SKEIN_256 = SkeinEngine.SKEIN_256; + /** + * 512 bit block size - Skein-512 + */ + public static final int SKEIN_512 = SkeinEngine.SKEIN_512; + /** + * 1024 bit block size - Skein-1024 + */ + public static final int SKEIN_1024 = SkeinEngine.SKEIN_1024; + + private SkeinEngine engine; + + /** + * Constructs a Skein digest 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/digest size to produce in bits, which must be an integral number of + * bytes. + */ + public SkeinDigest(int stateSizeBits, int digestSizeBits) + { + this.engine = new SkeinEngine(stateSizeBits, digestSizeBits); + init(null); + } + + public SkeinDigest(SkeinDigest digest) + { + this.engine = new SkeinEngine(digest.engine); + } + + public void reset(Memoable other) + { + SkeinDigest d = (SkeinDigest)other; + engine.reset(d.engine); + } + + public Memoable copy() + { + return new SkeinDigest(this); + } + + public String getAlgorithmName() + { + return "Skein-" + (engine.getBlockSize() * 8) + "-" + (engine.getOutputSize() * 8); + } + + public int getDigestSize() + { + return engine.getOutputSize(); + } + + public int getByteLength() + { + return engine.getBlockSize(); + } + + /** + * Optionally initialises the Skein digest with the provided parameters.<br> + * See {@link SkeinParameters} for details on the parameterisation of the Skein hash function. + * + * @param params the parameters to apply to this engine, or <code>null</code> to use no parameters. + */ + public void init(SkeinParameters params) + { + engine.init(params); + } + + 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); + } + +} |