Sha3Digest
Implementation of SHA-3 based on following KeccakNISTInterface.c from http://keccak.noekeon.org/
using Org.BouncyCastle.Crypto.Utilities;
using Org.BouncyCastle.Math.Raw;
using Org.BouncyCastle.Utilities;
using System;
namespace Org.BouncyCastle.Crypto.Digests
{
public class Sha3Digest : KeccakDigest
{
public override string AlgorithmName => "SHA3-" + fixedOutputLength.ToString();
internal static void CalculateDigest(ulong[] input, int inputOffset, int inputLengthBits, byte[] output, int outputOffset, int outputLengthBits)
{
int num = inputLengthBits + 63 >> 6;
Check.DataLength(inputOffset > input.Length - num, "input buffer too short");
int len = outputLengthBits + 7 >> 3;
Check.OutputLength(output, outputOffset, len, "output buffer too short");
if ((inputLengthBits & 7) != 0)
throw new ArgumentOutOfRangeException("inputLengthBits");
switch (outputLengthBits) {
default:
throw new ArgumentOutOfRangeException("outputLengthBits");
case 224:
case 256:
case 384:
case 512: {
int num2 = 1600 - (outputLengthBits << 1);
int num3 = num2 >> 6;
ulong[] array = new ulong[25];
while (inputLengthBits >= num2) {
Nat.XorTo64(num3, input, inputOffset, array, 0);
inputOffset += num3;
inputLengthBits -= num2;
KeccakDigest.KeccakPermutation(array);
}
int num4 = inputLengthBits >> 6;
int num5 = inputLengthBits & 63;
Nat.XorTo64(num4, input, inputOffset, array, 0);
ulong num6 = 6;
if (num5 != 0) {
num6 <<= num5;
num6 = (ulong)((long)num6 | ((long)input[inputOffset + num4] & ~(-1 << num5)));
}
array[num4] ^= num6;
array[num3 - 1] ^= 9223372036854775808;
KeccakDigest.KeccakPermutation(array);
int num7 = outputLengthBits >> 6;
Pack.UInt64_To_LE(array, 0, num7, output, outputOffset);
if ((outputLengthBits & 32) != 0)
Pack.UInt32_To_LE((uint)array[num7], output, outputOffset + (num7 << 3));
break;
}
}
}
internal unsafe static void CalculateDigest(ReadOnlySpan<ulong> input, int inputLengthBits, Span<byte> output, int outputLengthBits)
{
int len = inputLengthBits + 63 >> 6;
Check.DataLength(input, len, "input buffer too short");
int len2 = outputLengthBits + 7 >> 3;
Check.OutputLength(output, len2, "output buffer too short");
if ((inputLengthBits & 7) != 0)
throw new ArgumentOutOfRangeException("inputLengthBits");
switch (outputLengthBits) {
default:
throw new ArgumentOutOfRangeException("outputLengthBits");
case 224:
case 256:
case 384:
case 512: {
int num = 1600 - (outputLengthBits << 1);
int num2 = num >> 6;
Span<ulong> span = new Span<ulong>(stackalloc byte[200], 25);
while (inputLengthBits >= num) {
Nat.XorTo64(num2, input, span);
int num3 = num2;
input = input.Slice(num3, input.Length - num3);
inputLengthBits -= num;
KeccakDigest.KeccakPermutation(span);
}
int num4 = inputLengthBits >> 6;
int num5 = inputLengthBits & 63;
Nat.XorTo64(num4, input, span);
ulong num6 = 6;
if (num5 != 0) {
num6 <<= num5;
num6 = (ulong)((long)num6 | ((long)input[num4] & ~(-1 << num5)));
}
span[num4] ^= num6;
span[num2 - 1] ^= 9223372036854775808;
KeccakDigest.KeccakPermutation(span);
int num7 = outputLengthBits >> 6;
Pack.UInt64_To_LE(span.Slice(0, num7), output);
if ((outputLengthBits & 32) != 0) {
int n = (int)span[num7];
int num3 = num7 << 3;
Pack.UInt32_To_LE((uint)n, output.Slice(num3, output.Length - num3));
}
break;
}
}
}
private static int CheckBitLength(int bitLength)
{
switch (bitLength) {
case 224:
case 256:
case 384:
case 512:
return bitLength;
default:
throw new ArgumentException(bitLength.ToString() + " not supported for SHA-3", "bitLength");
}
}
public Sha3Digest()
: this(256)
{
}
public Sha3Digest(int bitLength)
: base(CheckBitLength(bitLength))
{
}
public Sha3Digest(Sha3Digest source)
: base(source)
{
}
public override int DoFinal(byte[] output, int outOff)
{
AbsorbBits(2, 2);
return base.DoFinal(output, outOff);
}
public override int DoFinal(Span<byte> output)
{
AbsorbBits(2, 2);
return base.DoFinal(output);
}
protected override int DoFinal(byte[] output, int outOff, 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)) | (2 << partialBits);
int num2 = partialBits + 2;
if (num2 >= 8) {
Absorb((byte)num);
num2 -= 8;
num >>= 8;
}
return base.DoFinal(output, outOff, (byte)num, num2);
}
public override IMemoable Copy()
{
return new Sha3Digest(this);
}
}
}