IsapDigest
using Org.BouncyCastle.Crypto.Utilities;
using Org.BouncyCastle.Utilities;
using System;
using System.Runtime.CompilerServices;
namespace Org.BouncyCastle.Crypto.Digests
{
public sealed class IsapDigest : IDigest
{
private readonly byte[] m_buf = new byte[8];
private int m_bufPos;
private ulong x0 = 17191252062196199485;
private ulong x1 = 10066134719181819906;
private ulong x2 = 13009371945472744034;
private ulong x3 = 4834782570098516968;
private ulong x4 = 3787428097924915520;
public string AlgorithmName => "ISAP Hash";
public int GetDigestSize()
{
return 32;
}
public int GetByteLength()
{
return 8;
}
public void Update(byte input)
{
m_buf[m_bufPos] = input;
if (++m_bufPos == 8) {
x0 ^= Pack.BE_To_UInt64(m_buf, 0);
P12();
m_bufPos = 0;
}
}
public void BlockUpdate(byte[] input, int inOff, int inLen)
{
Check.DataLength(input, inOff, inLen, "input buffer too short");
if (inLen >= 1) {
int num = 8 - m_bufPos;
if (inLen < num) {
Array.Copy(input, inOff, m_buf, m_bufPos, inLen);
m_bufPos += inLen;
} else {
int num2 = 0;
if (m_bufPos > 0) {
Array.Copy(input, inOff, m_buf, m_bufPos, num);
num2 += num;
x0 ^= Pack.BE_To_UInt64(m_buf, 0);
P12();
}
int num3;
while ((num3 = inLen - num2) >= 8) {
x0 ^= Pack.BE_To_UInt64(input, inOff + num2);
P12();
num2 += 8;
}
Array.Copy(input, inOff + num2, m_buf, 0, num3);
m_bufPos = num3;
}
}
}
public int DoFinal(byte[] output, int outOff)
{
Check.OutputLength(output, outOff, 32, "output buffer too short");
FinishAbsorbing();
for (int i = 0; i < 4; i++) {
P12();
Pack.UInt64_To_BE(x0, output, outOff + (i << 3));
}
Reset();
return 32;
}
public void Reset()
{
Array.Clear(m_buf, 0, m_buf.Length);
m_bufPos = 0;
x0 = 17191252062196199485;
x1 = 10066134719181819906;
x2 = 13009371945472744034;
x3 = 4834782570098516968;
x4 = 3787428097924915520;
}
private void FinishAbsorbing()
{
m_buf[m_bufPos] = 128;
x0 ^= (ulong)((long)Pack.BE_To_UInt64(m_buf, 0) & (-1 << 56 - (m_bufPos << 3)));
}
private void P12()
{
ROUND(240);
ROUND(225);
ROUND(210);
ROUND(195);
ROUND(180);
ROUND(165);
ROUND(150);
ROUND(135);
ROUND(120);
ROUND(105);
ROUND(90);
ROUND(75);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private void ROUND(ulong c)
{
ulong num = x0 ^ x1 ^ x2 ^ x3 ^ c ^ (x1 & (x0 ^ x2 ^ x4 ^ c));
ulong num2 = x0 ^ x2 ^ x3 ^ x4 ^ c ^ ((x1 ^ x2 ^ c) & (x1 ^ x3));
ulong num3 = x1 ^ x2 ^ x4 ^ c ^ (x3 & x4);
ulong num4 = x0 ^ x1 ^ x2 ^ c ^ (~x0 & (x3 ^ x4));
ulong num5 = x1 ^ x3 ^ x4 ^ ((x0 ^ x4) & x1);
x0 = (num ^ Longs.RotateRight(num, 19) ^ Longs.RotateRight(num, 28));
x1 = (num2 ^ Longs.RotateRight(num2, 39) ^ Longs.RotateRight(num2, 61));
x2 = ~(num3 ^ Longs.RotateRight(num3, 1) ^ Longs.RotateRight(num3, 6));
x3 = (num4 ^ Longs.RotateRight(num4, 10) ^ Longs.RotateRight(num4, 17));
x4 = (num5 ^ Longs.RotateRight(num5, 7) ^ Longs.RotateRight(num5, 41));
}
}
}