using System;
using System.Linq;
using System.Text;

namespace System.Security.Cryptography
{
    public sealed class RIPEMD160Managed : IDisposable
    {
		private const int DigestLength = 20;
		private int _h0, _h1, _h2, _h3, _h4;
		private int[] X = new int[16];
		private int xOff;

		private byte[] xBuf = new byte[4];
		private int xBufOff;
		private long byteCount;

		public RIPEMD160Managed()
		{
			Reset();
		}

        public byte[] ComputeHash(byte[] data, int offset, int count)
        {
			BlockUpdate(data, offset, count);
			var rv = new byte[20];
			DoFinal(rv, 0);
			return rv;
        }

		public void Update(byte input)
		{
			xBuf[xBufOff++] = input;

			if(xBufOff == xBuf.Length)
			{
				ProcessWord(xBuf, 0);
				xBufOff = 0;
			}

			byteCount++;
		}

		public void BlockUpdate(byte[] input, int inOff, int length)
		{
			length = System.Math.Max(0, length);

			int i = 0;
			if(xBufOff != 0)
			{
				while(i < length)
				{
					xBuf[xBufOff++] = input[inOff + i++];
					if(xBufOff == 4)
					{
						ProcessWord(xBuf, 0);
						xBufOff = 0;
						break;
					}
				}
			}

			int limit = ((length - i) & ~3) + i;
			for(; i < limit; i += 4)
			{
				ProcessWord(input, inOff + i);
			}

			while(i < length)
			{
				xBuf[xBufOff++] = input[inOff + i++];
			}

			byteCount += length;
		}

		private void ProcessWord(byte[] input, int inOff)
		{
			X[xOff++] = (input[inOff] & 0xff) | ((input[inOff + 1] & 0xff) << 8)
				| ((input[inOff + 2] & 0xff) << 16) | ((input[inOff + 3] & 0xff) << 24);

			if(xOff == 16)
			{
				ProcessBlock();
			}
		}

		private void ProcessLength(long bitLength)
		{
			if(xOff > 14)
			{
				ProcessBlock();
			}

			X[14] = (int)(bitLength & 0xffffffff);
			X[15] = (int)((ulong)bitLength >> 32);
		}

		private void UnpackWord(int word, byte[] outBytes, int outOff)
		{
			outBytes[outOff] = (byte)word;
			outBytes[outOff + 1] = (byte)((uint)word >> 8);
			outBytes[outOff + 2] = (byte)((uint)word >> 16);
			outBytes[outOff + 3] = (byte)((uint)word >> 24);
		}

		public int DoFinal(byte[] output, int outOff)
		{
			Finish();

			UnpackWord(_h0, output, outOff);
			UnpackWord(_h1, output, outOff + 4);
			UnpackWord(_h2, output, outOff + 8);
			UnpackWord(_h3, output, outOff + 12);
			UnpackWord(_h4, output, outOff + 16);

			Reset();

			return DigestLength;
		}
		public void Finish()
		{
			long bitLength = (byteCount << 3);

			Update((byte)128);

			while(xBufOff != 0)
				Update((byte)0);
			ProcessLength(bitLength);
			ProcessBlock();
		}

		public void Reset()
		{
			byteCount = 0;
			xBufOff = 0;
			Array.Clear(xBuf, 0, xBuf.Length);

			_h0 = unchecked((int)0x67452301);
			_h1 = unchecked((int)0xefcdab89);
			_h2 = unchecked((int)0x98badcfe);
			_h3 = unchecked((int)0x10325476);
			_h4 = unchecked((int)0xc3d2e1f0);

			xOff = 0;

			for(int i = 0; i != X.Length; i++)
			{
				X[i] = 0;
			}
		}

        private static int RL(int x, int n) => (x << n) | (int)((uint)x >> (32 - n));
        private int F1(int x, int y, int z) => x ^ y ^ z;
        private int F2(int x, int y, int z) => (x & y) | (~x & z);
        private int F3(int x, int y, int z) => (x | ~y) ^ z;
        private int F4(int x, int y, int z) => (x & z) | (y & ~z);
        private int F5(int x, int y, int z) => x ^ (y | ~z);

        private void ProcessBlock()
		{
			int a, aa;
			int b, bb;
			int c, cc;
			int d, dd;
			int e, ee;

			a = aa = _h0;
			b = bb = _h1;
			c = cc = _h2;
			d = dd = _h3;
			e = ee = _h4;

			//
			// Rounds 1 - 16
			//
			// left
			a = RL(a + F1(b, c, d) + X[0], 11) + e;
			c = RL(c, 10);
			e = RL(e + F1(a, b, c) + X[1], 14) + d;
			b = RL(b, 10);
			d = RL(d + F1(e, a, b) + X[2], 15) + c;
			a = RL(a, 10);
			c = RL(c + F1(d, e, a) + X[3], 12) + b;
			e = RL(e, 10);
			b = RL(b + F1(c, d, e) + X[4], 5) + a;
			d = RL(d, 10);
			a = RL(a + F1(b, c, d) + X[5], 8) + e;
			c = RL(c, 10);
			e = RL(e + F1(a, b, c) + X[6], 7) + d;
			b = RL(b, 10);
			d = RL(d + F1(e, a, b) + X[7], 9) + c;
			a = RL(a, 10);
			c = RL(c + F1(d, e, a) + X[8], 11) + b;
			e = RL(e, 10);
			b = RL(b + F1(c, d, e) + X[9], 13) + a;
			d = RL(d, 10);
			a = RL(a + F1(b, c, d) + X[10], 14) + e;
			c = RL(c, 10);
			e = RL(e + F1(a, b, c) + X[11], 15) + d;
			b = RL(b, 10);
			d = RL(d + F1(e, a, b) + X[12], 6) + c;
			a = RL(a, 10);
			c = RL(c + F1(d, e, a) + X[13], 7) + b;
			e = RL(e, 10);
			b = RL(b + F1(c, d, e) + X[14], 9) + a;
			d = RL(d, 10);
			a = RL(a + F1(b, c, d) + X[15], 8) + e;
			c = RL(c, 10);

			// right
			aa = RL(aa + F5(bb, cc, dd) + X[5] + unchecked((int)0x50a28be6), 8) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F5(aa, bb, cc) + X[14] + unchecked((int)0x50a28be6), 9) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F5(ee, aa, bb) + X[7] + unchecked((int)0x50a28be6), 9) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F5(dd, ee, aa) + X[0] + unchecked((int)0x50a28be6), 11) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F5(cc, dd, ee) + X[9] + unchecked((int)0x50a28be6), 13) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F5(bb, cc, dd) + X[2] + unchecked((int)0x50a28be6), 15) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F5(aa, bb, cc) + X[11] + unchecked((int)0x50a28be6), 15) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F5(ee, aa, bb) + X[4] + unchecked((int)0x50a28be6), 5) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F5(dd, ee, aa) + X[13] + unchecked((int)0x50a28be6), 7) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F5(cc, dd, ee) + X[6] + unchecked((int)0x50a28be6), 7) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F5(bb, cc, dd) + X[15] + unchecked((int)0x50a28be6), 8) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F5(aa, bb, cc) + X[8] + unchecked((int)0x50a28be6), 11) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F5(ee, aa, bb) + X[1] + unchecked((int)0x50a28be6), 14) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F5(dd, ee, aa) + X[10] + unchecked((int)0x50a28be6), 14) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F5(cc, dd, ee) + X[3] + unchecked((int)0x50a28be6), 12) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F5(bb, cc, dd) + X[12] + unchecked((int)0x50a28be6), 6) + ee;
			cc = RL(cc, 10);

			//
			// Rounds 16-31
			//
			// left
			e = RL(e + F2(a, b, c) + X[7] + unchecked((int)0x5a827999), 7) + d;
			b = RL(b, 10);
			d = RL(d + F2(e, a, b) + X[4] + unchecked((int)0x5a827999), 6) + c;
			a = RL(a, 10);
			c = RL(c + F2(d, e, a) + X[13] + unchecked((int)0x5a827999), 8) + b;
			e = RL(e, 10);
			b = RL(b + F2(c, d, e) + X[1] + unchecked((int)0x5a827999), 13) + a;
			d = RL(d, 10);
			a = RL(a + F2(b, c, d) + X[10] + unchecked((int)0x5a827999), 11) + e;
			c = RL(c, 10);
			e = RL(e + F2(a, b, c) + X[6] + unchecked((int)0x5a827999), 9) + d;
			b = RL(b, 10);
			d = RL(d + F2(e, a, b) + X[15] + unchecked((int)0x5a827999), 7) + c;
			a = RL(a, 10);
			c = RL(c + F2(d, e, a) + X[3] + unchecked((int)0x5a827999), 15) + b;
			e = RL(e, 10);
			b = RL(b + F2(c, d, e) + X[12] + unchecked((int)0x5a827999), 7) + a;
			d = RL(d, 10);
			a = RL(a + F2(b, c, d) + X[0] + unchecked((int)0x5a827999), 12) + e;
			c = RL(c, 10);
			e = RL(e + F2(a, b, c) + X[9] + unchecked((int)0x5a827999), 15) + d;
			b = RL(b, 10);
			d = RL(d + F2(e, a, b) + X[5] + unchecked((int)0x5a827999), 9) + c;
			a = RL(a, 10);
			c = RL(c + F2(d, e, a) + X[2] + unchecked((int)0x5a827999), 11) + b;
			e = RL(e, 10);
			b = RL(b + F2(c, d, e) + X[14] + unchecked((int)0x5a827999), 7) + a;
			d = RL(d, 10);
			a = RL(a + F2(b, c, d) + X[11] + unchecked((int)0x5a827999), 13) + e;
			c = RL(c, 10);
			e = RL(e + F2(a, b, c) + X[8] + unchecked((int)0x5a827999), 12) + d;
			b = RL(b, 10);

			// right
			ee = RL(ee + F4(aa, bb, cc) + X[6] + unchecked((int)0x5c4dd124), 9) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F4(ee, aa, bb) + X[11] + unchecked((int)0x5c4dd124), 13) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F4(dd, ee, aa) + X[3] + unchecked((int)0x5c4dd124), 15) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F4(cc, dd, ee) + X[7] + unchecked((int)0x5c4dd124), 7) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F4(bb, cc, dd) + X[0] + unchecked((int)0x5c4dd124), 12) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F4(aa, bb, cc) + X[13] + unchecked((int)0x5c4dd124), 8) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F4(ee, aa, bb) + X[5] + unchecked((int)0x5c4dd124), 9) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F4(dd, ee, aa) + X[10] + unchecked((int)0x5c4dd124), 11) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F4(cc, dd, ee) + X[14] + unchecked((int)0x5c4dd124), 7) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F4(bb, cc, dd) + X[15] + unchecked((int)0x5c4dd124), 7) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F4(aa, bb, cc) + X[8] + unchecked((int)0x5c4dd124), 12) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F4(ee, aa, bb) + X[12] + unchecked((int)0x5c4dd124), 7) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F4(dd, ee, aa) + X[4] + unchecked((int)0x5c4dd124), 6) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F4(cc, dd, ee) + X[9] + unchecked((int)0x5c4dd124), 15) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F4(bb, cc, dd) + X[1] + unchecked((int)0x5c4dd124), 13) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F4(aa, bb, cc) + X[2] + unchecked((int)0x5c4dd124), 11) + dd;
			bb = RL(bb, 10);

			//
			// Rounds 32-47
			//
			// left
			d = RL(d + F3(e, a, b) + X[3] + unchecked((int)0x6ed9eba1), 11) + c;
			a = RL(a, 10);
			c = RL(c + F3(d, e, a) + X[10] + unchecked((int)0x6ed9eba1), 13) + b;
			e = RL(e, 10);
			b = RL(b + F3(c, d, e) + X[14] + unchecked((int)0x6ed9eba1), 6) + a;
			d = RL(d, 10);
			a = RL(a + F3(b, c, d) + X[4] + unchecked((int)0x6ed9eba1), 7) + e;
			c = RL(c, 10);
			e = RL(e + F3(a, b, c) + X[9] + unchecked((int)0x6ed9eba1), 14) + d;
			b = RL(b, 10);
			d = RL(d + F3(e, a, b) + X[15] + unchecked((int)0x6ed9eba1), 9) + c;
			a = RL(a, 10);
			c = RL(c + F3(d, e, a) + X[8] + unchecked((int)0x6ed9eba1), 13) + b;
			e = RL(e, 10);
			b = RL(b + F3(c, d, e) + X[1] + unchecked((int)0x6ed9eba1), 15) + a;
			d = RL(d, 10);
			a = RL(a + F3(b, c, d) + X[2] + unchecked((int)0x6ed9eba1), 14) + e;
			c = RL(c, 10);
			e = RL(e + F3(a, b, c) + X[7] + unchecked((int)0x6ed9eba1), 8) + d;
			b = RL(b, 10);
			d = RL(d + F3(e, a, b) + X[0] + unchecked((int)0x6ed9eba1), 13) + c;
			a = RL(a, 10);
			c = RL(c + F3(d, e, a) + X[6] + unchecked((int)0x6ed9eba1), 6) + b;
			e = RL(e, 10);
			b = RL(b + F3(c, d, e) + X[13] + unchecked((int)0x6ed9eba1), 5) + a;
			d = RL(d, 10);
			a = RL(a + F3(b, c, d) + X[11] + unchecked((int)0x6ed9eba1), 12) + e;
			c = RL(c, 10);
			e = RL(e + F3(a, b, c) + X[5] + unchecked((int)0x6ed9eba1), 7) + d;
			b = RL(b, 10);
			d = RL(d + F3(e, a, b) + X[12] + unchecked((int)0x6ed9eba1), 5) + c;
			a = RL(a, 10);

			// right
			dd = RL(dd + F3(ee, aa, bb) + X[15] + unchecked((int)0x6d703ef3), 9) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F3(dd, ee, aa) + X[5] + unchecked((int)0x6d703ef3), 7) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F3(cc, dd, ee) + X[1] + unchecked((int)0x6d703ef3), 15) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F3(bb, cc, dd) + X[3] + unchecked((int)0x6d703ef3), 11) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F3(aa, bb, cc) + X[7] + unchecked((int)0x6d703ef3), 8) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F3(ee, aa, bb) + X[14] + unchecked((int)0x6d703ef3), 6) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F3(dd, ee, aa) + X[6] + unchecked((int)0x6d703ef3), 6) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F3(cc, dd, ee) + X[9] + unchecked((int)0x6d703ef3), 14) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F3(bb, cc, dd) + X[11] + unchecked((int)0x6d703ef3), 12) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F3(aa, bb, cc) + X[8] + unchecked((int)0x6d703ef3), 13) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F3(ee, aa, bb) + X[12] + unchecked((int)0x6d703ef3), 5) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F3(dd, ee, aa) + X[2] + unchecked((int)0x6d703ef3), 14) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F3(cc, dd, ee) + X[10] + unchecked((int)0x6d703ef3), 13) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F3(bb, cc, dd) + X[0] + unchecked((int)0x6d703ef3), 13) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F3(aa, bb, cc) + X[4] + unchecked((int)0x6d703ef3), 7) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F3(ee, aa, bb) + X[13] + unchecked((int)0x6d703ef3), 5) + cc;
			aa = RL(aa, 10);

			//
			// Rounds 48-63
			//
			// left
			c = RL(c + F4(d, e, a) + X[1] + unchecked((int)0x8f1bbcdc), 11) + b;
			e = RL(e, 10);
			b = RL(b + F4(c, d, e) + X[9] + unchecked((int)0x8f1bbcdc), 12) + a;
			d = RL(d, 10);
			a = RL(a + F4(b, c, d) + X[11] + unchecked((int)0x8f1bbcdc), 14) + e;
			c = RL(c, 10);
			e = RL(e + F4(a, b, c) + X[10] + unchecked((int)0x8f1bbcdc), 15) + d;
			b = RL(b, 10);
			d = RL(d + F4(e, a, b) + X[0] + unchecked((int)0x8f1bbcdc), 14) + c;
			a = RL(a, 10);
			c = RL(c + F4(d, e, a) + X[8] + unchecked((int)0x8f1bbcdc), 15) + b;
			e = RL(e, 10);
			b = RL(b + F4(c, d, e) + X[12] + unchecked((int)0x8f1bbcdc), 9) + a;
			d = RL(d, 10);
			a = RL(a + F4(b, c, d) + X[4] + unchecked((int)0x8f1bbcdc), 8) + e;
			c = RL(c, 10);
			e = RL(e + F4(a, b, c) + X[13] + unchecked((int)0x8f1bbcdc), 9) + d;
			b = RL(b, 10);
			d = RL(d + F4(e, a, b) + X[3] + unchecked((int)0x8f1bbcdc), 14) + c;
			a = RL(a, 10);
			c = RL(c + F4(d, e, a) + X[7] + unchecked((int)0x8f1bbcdc), 5) + b;
			e = RL(e, 10);
			b = RL(b + F4(c, d, e) + X[15] + unchecked((int)0x8f1bbcdc), 6) + a;
			d = RL(d, 10);
			a = RL(a + F4(b, c, d) + X[14] + unchecked((int)0x8f1bbcdc), 8) + e;
			c = RL(c, 10);
			e = RL(e + F4(a, b, c) + X[5] + unchecked((int)0x8f1bbcdc), 6) + d;
			b = RL(b, 10);
			d = RL(d + F4(e, a, b) + X[6] + unchecked((int)0x8f1bbcdc), 5) + c;
			a = RL(a, 10);
			c = RL(c + F4(d, e, a) + X[2] + unchecked((int)0x8f1bbcdc), 12) + b;
			e = RL(e, 10);

			// right
			cc = RL(cc + F2(dd, ee, aa) + X[8] + unchecked((int)0x7a6d76e9), 15) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F2(cc, dd, ee) + X[6] + unchecked((int)0x7a6d76e9), 5) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F2(bb, cc, dd) + X[4] + unchecked((int)0x7a6d76e9), 8) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F2(aa, bb, cc) + X[1] + unchecked((int)0x7a6d76e9), 11) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F2(ee, aa, bb) + X[3] + unchecked((int)0x7a6d76e9), 14) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F2(dd, ee, aa) + X[11] + unchecked((int)0x7a6d76e9), 14) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F2(cc, dd, ee) + X[15] + unchecked((int)0x7a6d76e9), 6) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F2(bb, cc, dd) + X[0] + unchecked((int)0x7a6d76e9), 14) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F2(aa, bb, cc) + X[5] + unchecked((int)0x7a6d76e9), 6) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F2(ee, aa, bb) + X[12] + unchecked((int)0x7a6d76e9), 9) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F2(dd, ee, aa) + X[2] + unchecked((int)0x7a6d76e9), 12) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F2(cc, dd, ee) + X[13] + unchecked((int)0x7a6d76e9), 9) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F2(bb, cc, dd) + X[9] + unchecked((int)0x7a6d76e9), 12) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F2(aa, bb, cc) + X[7] + unchecked((int)0x7a6d76e9), 5) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F2(ee, aa, bb) + X[10] + unchecked((int)0x7a6d76e9), 15) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F2(dd, ee, aa) + X[14] + unchecked((int)0x7a6d76e9), 8) + bb;
			ee = RL(ee, 10);

			//
			// Rounds 64-79
			//
			// left
			b = RL(b + F5(c, d, e) + X[4] + unchecked((int)0xa953fd4e), 9) + a;
			d = RL(d, 10);
			a = RL(a + F5(b, c, d) + X[0] + unchecked((int)0xa953fd4e), 15) + e;
			c = RL(c, 10);
			e = RL(e + F5(a, b, c) + X[5] + unchecked((int)0xa953fd4e), 5) + d;
			b = RL(b, 10);
			d = RL(d + F5(e, a, b) + X[9] + unchecked((int)0xa953fd4e), 11) + c;
			a = RL(a, 10);
			c = RL(c + F5(d, e, a) + X[7] + unchecked((int)0xa953fd4e), 6) + b;
			e = RL(e, 10);
			b = RL(b + F5(c, d, e) + X[12] + unchecked((int)0xa953fd4e), 8) + a;
			d = RL(d, 10);
			a = RL(a + F5(b, c, d) + X[2] + unchecked((int)0xa953fd4e), 13) + e;
			c = RL(c, 10);
			e = RL(e + F5(a, b, c) + X[10] + unchecked((int)0xa953fd4e), 12) + d;
			b = RL(b, 10);
			d = RL(d + F5(e, a, b) + X[14] + unchecked((int)0xa953fd4e), 5) + c;
			a = RL(a, 10);
			c = RL(c + F5(d, e, a) + X[1] + unchecked((int)0xa953fd4e), 12) + b;
			e = RL(e, 10);
			b = RL(b + F5(c, d, e) + X[3] + unchecked((int)0xa953fd4e), 13) + a;
			d = RL(d, 10);
			a = RL(a + F5(b, c, d) + X[8] + unchecked((int)0xa953fd4e), 14) + e;
			c = RL(c, 10);
			e = RL(e + F5(a, b, c) + X[11] + unchecked((int)0xa953fd4e), 11) + d;
			b = RL(b, 10);
			d = RL(d + F5(e, a, b) + X[6] + unchecked((int)0xa953fd4e), 8) + c;
			a = RL(a, 10);
			c = RL(c + F5(d, e, a) + X[15] + unchecked((int)0xa953fd4e), 5) + b;
			e = RL(e, 10);
			b = RL(b + F5(c, d, e) + X[13] + unchecked((int)0xa953fd4e), 6) + a;
			d = RL(d, 10);

			// right
			bb = RL(bb + F1(cc, dd, ee) + X[12], 8) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F1(bb, cc, dd) + X[15], 5) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F1(aa, bb, cc) + X[10], 12) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F1(ee, aa, bb) + X[4], 9) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F1(dd, ee, aa) + X[1], 12) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F1(cc, dd, ee) + X[5], 5) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F1(bb, cc, dd) + X[8], 14) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F1(aa, bb, cc) + X[7], 6) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F1(ee, aa, bb) + X[6], 8) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F1(dd, ee, aa) + X[2], 13) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F1(cc, dd, ee) + X[13], 6) + aa;
			dd = RL(dd, 10);
			aa = RL(aa + F1(bb, cc, dd) + X[14], 5) + ee;
			cc = RL(cc, 10);
			ee = RL(ee + F1(aa, bb, cc) + X[0], 15) + dd;
			bb = RL(bb, 10);
			dd = RL(dd + F1(ee, aa, bb) + X[3], 13) + cc;
			aa = RL(aa, 10);
			cc = RL(cc + F1(dd, ee, aa) + X[9], 11) + bb;
			ee = RL(ee, 10);
			bb = RL(bb + F1(cc, dd, ee) + X[11], 11) + aa;
			dd = RL(dd, 10);

			dd += c + _h1;
			_h1 = _h2 + d + ee;
			_h2 = _h3 + e + aa;
			_h3 = _h4 + a + bb;
			_h4 = _h0 + b + cc;
			_h0 = dd;

			//
			// reset the offset and clean out the word buffer.
			//
			xOff = 0;
			for(int i = 0; i != X.Length; i++)
			{
				X[i] = 0;
			}
		}

        public void Dispose()
        {
			for(int i = 0; i != X.Length; i++)
			{
				X[i] = 0;
			}
        }
    }
}
