cemu-DS4Windows/DS4Windows/DS4Library/Crc32.cs
Travis Nickles c228b4348c Removed use of rectangular array for CRC32
Now use one dimensional array instead
2018-03-06 11:47:24 -06:00

391 lines
17 KiB
C#

/*
Modified version of http://damieng.com/blog/2006/08/08/calculating_crc32_in_c_and_net
Using a default table improves drastically the performance of the algorithm.
Credit for the implementation should be awarded to Damien Guard.
Modified under the intention of creating a Nuget package
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
Originally published at http://damieng.com/blog/2006/08/08/calculating_crc32_in_c_and_net
*/
using System;
using System.Security.Cryptography;
namespace DS4Windows
{
/// <summary>
/// Implements a 32-bit CRC hash algorithm compatible with Zip etc.
/// </summary>
/// <remarks>
/// Crc32 should only be used for backward compatibility with older file formats
/// and algorithms. It is not secure enough for new applications.
/// If you need to call multiple times for the same data either use the HashAlgorithm
/// interface or remember that the result of one Compute call needs to be ~ (XOR) before
/// being passed in as the seed for the next Compute call.
/// </remarks>
public sealed class Crc32Algorithm : HashAlgorithm
{
public const uint DefaultPolynomial = 0xedb88320u;
public const uint DefaultSeed = 0xffffffffu;
private static readonly uint[] defaultTable =
{
0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA,
0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,
0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE,
0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC,
0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,
0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940,
0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116,
0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,
0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A,
0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818,
0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,
0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C,
0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2,
0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,
0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,
0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086,
0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4,
0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,
0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,
0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8,
0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE,
0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,
0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252,
0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60,
0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,
0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04,
0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A,
0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,
0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E,
0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C,
0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,
0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,
0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0,
0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6,
0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
};
private static uint[] testLook = new uint[16 * 256];
private static bool secondTablePop = false;
private readonly uint _seed;
private readonly uint[] _table;
private uint _hash;
public Crc32Algorithm()
: this(DefaultPolynomial, DefaultSeed)
{
}
public Crc32Algorithm(uint polynomial, uint seed)
{
_table = InitializeTable(polynomial);
_seed = _hash = seed;
}
public override void Initialize()
{
_hash = _seed;
}
protected override void HashCore(byte[] buffer, int start, int length)
{
_hash = CalculateHash(_table, _hash, buffer, start, length);
}
protected override byte[] HashFinal()
{
var hashBuffer = UintToBigEndianBytes(~_hash);
HashValue = hashBuffer;
return hashBuffer;
}
public override int HashSize { get { return 32; } }
public static uint Compute(byte[] buffer)
{
return ~CalculateHash(defaultTable, DefaultSeed, buffer, 0, buffer.Length);
}
public static uint Compute(uint seed, byte[] buffer)
{
return ~CalculateHash(defaultTable, seed, buffer, 0, buffer.Length);
}
public static uint Compute(uint polynomial, uint seed, byte[] buffer)
{
return ~CalculateHash(InitializeTable(polynomial), seed, buffer, 0, buffer.Length);
}
public static uint[] InitializeTable(uint polynomial)
{
if (polynomial == DefaultPolynomial)
{
if (!secondTablePop)
{
for (int i = 0; i <= 0xFF; i++)
{
testLook[0 + i] = defaultTable[i];
testLook[256+i] = (defaultTable[i] >> 8) ^ defaultTable[defaultTable[i] & 0xFF];
testLook[512 + i] = (testLook[256 + i] >> 8) ^ defaultTable[testLook[256 + i] & 0xFF];
testLook[768 + i] = (testLook[512 + i] >> 8) ^ defaultTable[testLook[512 + i] & 0xFF];
testLook[1024 + i] = (testLook[768 + i] >> 8) ^ defaultTable[testLook[768 + i] & 0xFF];
testLook[1280 + i] = (testLook[1024 + i] >> 8) ^ defaultTable[testLook[1024 + i] & 0xFF];
testLook[1536 + i] = (testLook[1280 + i] >> 8) ^ defaultTable[testLook[1280 + i] & 0xFF];
testLook[1792 + i] = (testLook[1536 + i] >> 8) ^ defaultTable[testLook[1536 + i] & 0xFF];
testLook[2048 + i] = (testLook[1792 + i] >> 8) ^ defaultTable[testLook[1792 + i] & 0xFF];
testLook[2304 + i] = (testLook[2048 + i] >> 8) ^ defaultTable[testLook[2048 + i] & 0xFF];
testLook[2560 + i] = (testLook[2304 + i] >> 8) ^ defaultTable[testLook[2304 + i] & 0xFF];
testLook[2816 + i] = (testLook[2560 + i] >> 8) ^ defaultTable[testLook[2560 + i] & 0xFF];
testLook[3072 + i] = (testLook[2816 + i] >> 8) ^ defaultTable[testLook[2816 + i] & 0xFF];
testLook[3328 + i] = (testLook[3072 + i] >> 8) ^ defaultTable[testLook[3072 + i] & 0xFF];
testLook[3584 + i] = (testLook[3328 + i] >> 8) ^ defaultTable[testLook[3328 + i] & 0xFF];
testLook[3840 + i] = (testLook[3584 + i] >> 8) ^ defaultTable[testLook[3584 + i] & 0xFF];
}
secondTablePop = true;
}
return defaultTable;
}
var createTable = new uint[256];
for (uint i = 0; i < 256; i++)
{
var entry = i;
for (var j = 0; j < 8; j++)
entry = ((entry & 1) == 1) ? (entry >> 1) ^ polynomial : (entry >> 1);
createTable[i] = entry;
}
return createTable;
}
private static uint CalculateHash(uint[] table, uint seed, byte[] buffer, int start, int size)
{
var crc = seed;
for (var i = start; i < size - start; i++)
crc = (crc >> 8) ^ table[buffer[i] ^ crc & 0xff];
return crc;
}
public static unsafe uint CalculateBasicHash(ref uint seed, ref byte[] buffer, int offset, int size)
{
uint crc = seed;
int i = offset;
fixed (byte* byteP = buffer)
fixed (uint* byteT = testLook)
{
while (size >= 16)
{
uint one = (byteP[i++] |
(uint)(byteP[i++] << 8) |
(uint)(byteP[i++] << 16) |
(uint)(byteP[i++] << 24)) ^ crc;
uint two = byteP[i++] |
(uint)(byteP[i++] << 8) |
(uint)(byteP[i++] << 16) |
(uint)(byteP[i++] << 24);
uint three = (byteP[i++] |
(uint)(byteP[i++] << 8) |
(uint)(byteP[i++] << 16) |
(uint)(byteP[i++] << 24));
uint four = byteP[i++] |
(uint)(byteP[i++] << 8) |
(uint)(byteP[i++] << 16) |
(uint)(byteP[i++] << 24);
crc = byteT[3840 + (one & 0xFF)] ^
byteT[3584 + ((one >> 8) & 0xFF)] ^
byteT[3328 + ((one >> 16) & 0xFF)] ^
byteT[3072 + ((one >> 24) & 0xFF)] ^
byteT[2816 + (two & 0xFF)] ^
byteT[2560 + ((two >> 8) & 0xFF)] ^
byteT[2304 + ((two >> 16) & 0xFF)] ^
byteT[2048 + ((two >> 24) & 0xFF)] ^
byteT[1792 + (three & 0xFF)] ^
byteT[1536 + ((three >> 8) & 0xFF)] ^
byteT[1280 + ((three >> 16) & 0xFF)] ^
byteT[1024 + ((three >> 24) & 0xFF)] ^
byteT[768 + (four & 0xFF)] ^
byteT[512 + ((four >> 8) & 0xFF)] ^
byteT[256 + ((four >> 16) & 0xFF)] ^
byteT[(four >> 24) & 0xFF];
size -= 16;
}
while (size >= 8)
{
uint one8 = (byteP[i++] |
(uint)(byteP[i++] << 8) |
(uint)(byteP[i++] << 16) |
(uint)(byteP[i++] << 24)) ^ crc;
uint two8 = byteP[i++] |
(uint)(byteP[i++] << 8) |
(uint)(byteP[i++] << 16) |
(uint)(byteP[i++] << 24);
crc = byteT[1792 + (one8 & 0xFF)] ^
byteT[1536 + ((one8 >> 8) & 0xFF)] ^
byteT[1280 + ((one8 >> 16) & 0xFF)] ^
byteT[1024 + (one8 >> 24)] ^
byteT[768 + (two8 & 0xFF)] ^
byteT[512 + ((two8 >> 8) & 0xFF)] ^
byteT[256 + ((two8 >> 16) & 0xFF)] ^
byteT[two8 >> 24];
size -= 8;
}
while (--size >= 0)
{
crc = (crc >> 8) ^ byteT[(crc & 0xFF) ^ byteP[i++]];// i++;
}
}
return crc;
}
public static unsafe uint CalculateFasterBTHash(ref uint seed, ref byte[] buffer, ref int start, ref int size)
{
/*uint crc = seed;
for (int i = start; i < size + start; i++)
crc = (crc >> 8) ^ defaultTable[buffer[i] ^ crc & 0xff];
return crc;
*/
uint crc = seed;
int i = start;
int bufsize = size;
//while (bufsize >= 16)
fixed (byte* byteP = buffer)
fixed (uint* byteT = testLook)
{
for (int j = 0; j < 4; j++)
{
uint one = (byteP[i++] |
(uint)(byteP[i++] << 8) |
(uint)(byteP[i++] << 16) |
(uint)(byteP[i++] << 24)) ^ crc;
uint two = byteP[i++] |
(uint)(byteP[i++] << 8) |
(uint)(byteP[i++] << 16) |
(uint)(byteP[i++] << 24);
uint three = (byteP[i++] |
(uint)(byteP[i++] << 8) |
(uint)(byteP[i++] << 16) |
(uint)(byteP[i++] << 24));
uint four = byteP[i++] |
(uint)(byteP[i++] << 8) |
(uint)(byteP[i++] << 16) |
(uint)(byteP[i++] << 24);
crc = byteT[3840+(one & 0xFF)] ^
byteT[3584+((one >> 8) & 0xFF)] ^
byteT[3328+((one >> 16) & 0xFF)] ^
byteT[3072+((one >> 24) & 0xFF)] ^
byteT[2816+(two & 0xFF)] ^
byteT[2560+((two >> 8) & 0xFF)] ^
byteT[2304+((two >> 16) & 0xFF)] ^
byteT[2048+((two >> 24) & 0xFF)] ^
byteT[1792+(three & 0xFF)] ^
byteT[1536+((three >> 8) & 0xFF)] ^
byteT[1280+((three >> 16) & 0xFF)] ^
byteT[1024+((three >> 24) & 0xFF)] ^
byteT[768+(four & 0xFF)] ^
byteT[512+((four >> 8) & 0xFF)] ^
byteT[256+((four >> 16) & 0xFF)] ^
byteT[(four >> 24) & 0xFF];
bufsize -= 16;
}
//while (bufsize >= 8)
//if (bufsize >= 8)
uint one8 = (byteP[i++] |
(uint)(byteP[i++] << 8) |
(uint)(byteP[i++] << 16) |
(uint)(byteP[i++] << 24)) ^ crc;
uint two8 = byteP[i++] |
(uint)(byteP[i++] << 8) |
(uint)(byteP[i++] << 16) |
(uint)(byteP[i++] << 24);
crc = byteT[1792+(one8 & 0xFF)] ^
byteT[1536+((one8 >> 8) & 0xFF)] ^
byteT[1280+((one8 >> 16) & 0xFF)] ^
byteT[1024+(one8 >> 24)] ^
byteT[768+(two8 & 0xFF)] ^
byteT[512+((two8 >> 8) & 0xFF)] ^
byteT[256+((two8 >> 16) & 0xFF)] ^
byteT[two8 >> 24];
bufsize -= 8;
/*crc ^= buffer[i++] |
(uint)(buffer[i++] << 8) |
(uint)(buffer[i++] << 16) |
(uint)(buffer[i++] << 24);// i = i + 4;
//crc ^= buffer[i];
crc = secondLook[3, (crc & 0xFF)] ^
secondLook[2, ((crc >> 8) & 0xFF)] ^
secondLook[1, ((crc >> 16) & 0xFF)] ^
defaultTable[crc >> 24];
bufsize -= 4;
*/
//while (--bufsize >= 0)
//{
crc = (crc >> 8) ^ byteT[(crc & 0xFF) ^ byteP[i++]];// i++;
crc = (crc >> 8) ^ byteT[(crc & 0xFF) ^ byteP[i++]];// i++;
//}
}
return crc;
}
private static byte[] UintToBigEndianBytes(uint uint32)
{
var result = BitConverter.GetBytes(uint32);
if (BitConverter.IsLittleEndian)
Array.Reverse(result);
return result;
}
}
}