init commit

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Crypto/Digests/ShakeDigest.cs

@@ -0,0 +1,88 @@
+using System;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Digests;
+
+public class ShakeDigest : KeccakDigest, IXof, IDigest
+{
+	public override string AlgorithmName => "SHAKE" + fixedOutputLength;
+
+	private static int CheckBitLength(int bitLength)
+	{
+		if (bitLength == 128 || bitLength == 256)
+		{
+			return bitLength;
+		}
+		throw new ArgumentException(bitLength + " not supported for SHAKE", "bitLength");
+	}
+
+	public ShakeDigest()
+		: this(128)
+	{
+	}
+
+	public ShakeDigest(int bitLength)
+		: base(CheckBitLength(bitLength))
+	{
+	}
+
+	public ShakeDigest(ShakeDigest source)
+		: base(source)
+	{
+	}
+
+	public override int DoFinal(byte[] output, int outOff)
+	{
+		return DoFinal(output, outOff, GetDigestSize());
+	}
+
+	public virtual int DoFinal(byte[] output, int outOff, int outLen)
+	{
+		DoOutput(output, outOff, outLen);
+		Reset();
+		return outLen;
+	}
+
+	public virtual int DoOutput(byte[] output, int outOff, int outLen)
+	{
+		if (!squeezing)
+		{
+			AbsorbBits(15, 4);
+		}
+		Squeeze(output, outOff, (long)outLen << 3);
+		return outLen;
+	}
+
+	protected override int DoFinal(byte[] output, int outOff, byte partialByte, int partialBits)
+	{
+		return DoFinal(output, outOff, GetDigestSize(), partialByte, partialBits);
+	}
+
+	protected virtual int DoFinal(byte[] output, int outOff, int outLen, byte partialByte, int partialBits)
+	{
+		if (partialBits < 0 || partialBits > 7)
+		{
+			throw new ArgumentException("must be in the range [0,7]", "partialBits");
+		}
+		int num = (partialByte & ((1 << partialBits) - 1)) | (15 << partialBits);
+		int num2 = partialBits + 4;
+		if (num2 >= 8)
+		{
+			Absorb(new byte[1] { (byte)num }, 0, 1);
+			num2 -= 8;
+			num >>= 8;
+		}
+		if (num2 > 0)
+		{
+			AbsorbBits(num, num2);
+		}
+		Squeeze(output, outOff, (long)outLen << 3);
+		Reset();
+		return outLen;
+	}
+
+	public override IMemoable Copy()
+	{
+		return new ShakeDigest(this);
+	}
+}