public static unsafe uint CalculateCRCForChunk(string chunkType, byte[] chunkData)
{
byte[] chunkTypeBytes = Encoding.UTF8.GetBytes(chunkType);
Crc32 crc32Calculator = new Crc32();
crc32Calculator.Append(chunkTypeBytes);
crc32Calculator.Append(chunkData);
Span <byte> hashData = stackalloc byte[4];
crc32Calculator.GetCurrentHash(hashData);
return(BinaryPrimitives.ReadUInt32LittleEndian(hashData));
}
/// <summary>
/// Computes CRC-32 (IEEE 802.3) digest from given data.
/// </summary>
/// <param name="value">Unicode text for performing hash functions.</param>
/// <param name="useAsciiEncoding">If True, ASCII encoding is used instead of Unicode.</param>
public static int ComputeCrc(string value, bool useAsciiEncoding)
{
Crc32 crc = new Crc32();
crc.Append(value, useAsciiEncoding);
return(crc.Digest);
}
/// <summary>
/// Computes CRC-32 (IEEE 802.3) digest from given data.
/// </summary>
/// <param name="value">Value.</param>
/// <param name="index">A 32-bit integer that represents the index at which data begins.</param>
/// <param name="length">A 32-bit integer that represents the number of elements.</param>
public static int ComputeCrc(byte[] value, int index, int length)
{
Crc32 crc = new Crc32();
crc.Append(value, index, length);
return(crc.Digest);
}
/// <summary>
/// Computes CRC-32 (IEEE 802.3) digest from given data.
/// </summary>
/// <param name="value">Value.</param>
public static int ComputeCrc(byte[] value)
{
Crc32 crc = new Crc32();
crc.Append(value);
return(crc.Digest);
}
public void Crc32_Ieee()
{
string expected = "1A657BE2";
Crc32 actualCrc = Crc32.GetIeee();
actualCrc.Append("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ", true);
string actual = actualCrc.Digest.ToString("X8");
Assert.AreEqual(expected, actual);
}
public void TestCrc32(string name, uint polynomial, uint initialState, uint xorOutput, bool reverseInput, bool reverseOutput, uint check)
{
using (Crc32 crc = new Crc32(polynomial, initialState, xorOutput, reverseInput, reverseOutput))
{
crc.Initialize();
var bytes = Encoding.UTF8.GetBytes(data);
for (int i = 0; i < bytes.Length; i++)
{
crc.Append(bytes[i]);
}
uint output = crc.CurrentOutput;
Assert.AreEqual(check, output, 0);
}
}
