C# Crc32 实现

Question

我有以下示例:

3D020000000F0000112233445566778899AABBCCDDEEFF - Crc32 Input
280ACDA5 - Crc32 Result

但使用以下计算器:sunshine2k和 zorc.breitbandkatze我无法重建结果。文档说:Polynomial-04C11DB7、Reverse-EDB88320、Initvalue-FFFFFFFF 以及结果不应反转。

我在 NuGet 上搜索了库并找到了 Nito但也得不到正确的结果。我还尝试了标志和多项式的所有组合(04C11DB7、EDB88320)。

有人能告诉我我做错了什么吗？计算器和库错了吗？我也尝试过在两侧和 lib 上使用相同的 polinom 和标志组合，但得到了不同的结果 :-( 有人可以告诉 lib 哪个绝对正确吗？

这是我的测试代码:

        [Theory]
        [InlineData("3D 00 00 00 00 10 00 00 23 00 00 00 00 00 00 08 12 34 56 78 00 00 00 00", "7B 8A 60 0F")]
        [InlineData("3D020000000F0000112233445566778899AABBCCDDEEFF", "280ACDA5")]
        public void Crc32_Test(string input, string assumedCrc32)
        {
            var definition = new Definition
            {
                Initializer = 0xFFFFFFFF,
                TruncatedPolynomial = 0xEDB88320,
                ReverseResultBeforeFinalXor = false,
                ReverseDataBytes = false,
            };

            var whow = new Nito.HashAlgorithms.CRC32(definition);

            var inputArray = DESFireSessionHandler.StringToByte(input);
            var assumedCrc32Array = DESFireSessionHandler.StringToByte(assumedCrc32);

            var crc32 = whow.ComputeHash(inputArray);

            if (crc32.SequenceEqual(assumedCrc32Array))
                Assert.True(true);
            else if (crc32.Reverse().SequenceEqual(assumedCrc32Array))
                Assert.True(true);
            else Assert.False(true);
}

Answer 1

以下参数产生所需的结果 280ACDA5:

Initializer = 0xFFFFFFFF,
TruncatedPolynomial = 0x04C11DB7,
FinalXorValue = 0x00000000,
ReverseResultBeforeFinalXor = true,
ReverseDataBytes = true

---

这与在线工具相同(字节顺序除外):

https://crccalc.com/

http://www.sunshine2k.de/coding/javascript/crc/crc_js.html

---

完整的C#代码是:

using System;
using static Nito.HashAlgorithms.CRC32;
                    
public class Program
{
    public static void Main()
    {
        var definition = new Definition
        {
            Initializer = 0xFFFFFFFF,
            TruncatedPolynomial = 0x04C11DB7,
            FinalXorValue = 0x00000000,
            ReverseResultBeforeFinalXor = true,
            ReverseDataBytes = true
        };

        var inputHex = "3D020000000F0000112233445566778899AABBCCDDEEFF";
        var input = Convert.FromHexString(inputHex);
        var whow = new Nito.HashAlgorithms.CRC32(definition);
        
        var crc32 = whow.ComputeHash(input);
        var crc32Hex = Convert.ToHexString(crc32);
        Console.WriteLine(crc32Hex); // 280ACDA5
    }
}