NullFX CRC

NullFX CRC is a small set of CRC utilities written in native C# released under the MIT License

NuGet:

GitHub Package Page

NuGet.org Package Page

Install

dotnet add package NullFX.CRC

Run this from the folder that contains your project file (or add the project path after dotnet add). The latest released version is installed; the NuGet badge above shows the current version.

Supported target frameworks: netstandard2.0, netcoreapp3.1, net40, net45, net46, net47, net48, net6.0, net7.0, net8.0 and net10.0.

Examples:

Each CRC library uses a common ComputeChecksum format. It accepts a byte array which can be obtained by converting text / numbers / structures etc into an array, then passing the byte array into ComputeChecksum for it's CRC.

The ComputeChecksum method also has a params argument parameter allowing individual bytes to be passed into the method one at a time rather than as an array.

If a checksum needs to be performed on a segment of an array, rather than creating a copy of the array to perform the CRC on, you can pass in the entire buffer and specify the section of the array in which to perform the CRC calculation, saving time and memory:

// using text
var text = "I am string content";
// convert text to a byte array
var textBuffer = System.Text.Encoding.UTF8.GetBytes ( text );

// get the CRC for the text
var textCrc = NullFX.CRC.Crc32.ComputeChecksum ( textBuffer );
Console.WriteLine ( "Text CRC: {0:X8}", textCrc );


// use a large number
var aNumber = 0xDEADBEEF;
// convert that to a byte array
var numberBuffer = System.BitConverter.GetBytes ( aNumber );

// get the CRC for the number
var numberCrc = NullFX.CRC.Crc32.ComputeChecksum ( numberBuffer );
Console.WriteLine ( "Number CRC: {0:X8}", numberCrc );


// bytes as params
var randomCrc = NullFX.CRC.Crc32.ComputeChecksum ( 0x01, 0x02, 0x03, 0x04 );
Console.WriteLine ( "Random bytes CRC: {0:X8}", randomCrc );


/// checksum of a subset of an array. perform the CRC on bytes at indices
// 2, 3, 4 and 5
var bytes = new byte[] { 0xFE, 0x2C, 0xED, 0x4B, 0x88, 0x31, 0x07, 0xBE };
var segmentedBytesCrc = Crc32.ComputeChecksum ( bytes, 2, 4 );
Console.WriteLine ( "Segment of bytes CRC: {0:X8}", segmentedBytesCrc );

Output:

Text CRC: 3AD00FD2
Number CRC: 1A5A601F
Random bytes CRC: B63CFBCD
Segment of bytes CRC: DB1A36A1

API Information

Crc8, and Crc32's ComputeChecksum have 2 different signatures

ComputeChecksum(byte[] bytes)

and

ComputeChecksum(byte[] bytes, int start, int length )

Crc16 has one additional initial parameter ( Crc16Algorithm ) where Crc16Algorithm is one of the following:

• Standard CRC 16
• CRC 16 CCITT with initial values of 0, FFFF and 1D0F
  • CRC 16 CCITT Kermit
• Modbus

ComputeChecksum ( Crc16Algorithm algorithm, byte[] bytes )

and

ComputeChecksum ( Crc16Algorithm algorithm, byte[] bytes, int start, int length )

.

Note: this repository is also mirrored on GitLab

Benchmarks

BenchmarkDotNet ShortRun results from the release build for v1.1.15 on a GitHub-hosted runner. Absolute timings vary between runs and machines; compare rows within a table.

BenchmarkDotNet v0.15.8, Windows 11 (10.0.26100.33438/24H2/2024Update/HudsonValley) (Hyper-V)
AMD EPYC 7763 2.44GHz, 1 CPU, 4 logical and 2 physical cores
.NET SDK 10.0.401
  [Host]   : .NET 10.0.12 (10.0.12, 10.0.1226.42308), X64 RyuJIT x86-64-v3
  ShortRun : .NET 10.0.12 (10.0.12, 10.0.1226.42308), X64 RyuJIT x86-64-v3

Job=ShortRun  IterationCount=3  LaunchCount=1  
WarmupCount=3  

Method	ArraySize	Mean	Error	StdDev
NullFxCrc8	10	8.676 ns	0.4364 ns	0.0239 ns
NullFxCrc16	10	13.695 ns	3.3818 ns	0.1854 ns
NullFxCrc32	10	12.138 ns	1.0032 ns	0.0550 ns
DataHashFunctionCrc8	10	98.618 ns	26.8391 ns	1.4711 ns
DataHashFunctionCrc16	10	110.368 ns	14.7429 ns	0.8081 ns
DataHashFunctionCrc32	10	114.110 ns	18.3534 ns	1.0060 ns
NullFxCrc8	100	155.654 ns	4.5711 ns	0.2506 ns
NullFxCrc16	100	261.538 ns	1.3877 ns	0.0761 ns
NullFxCrc32	100	232.148 ns	9.4263 ns	0.5167 ns
DataHashFunctionCrc8	100	427.921 ns	18.4161 ns	1.0095 ns
DataHashFunctionCrc16	100	568.411 ns	33.0251 ns	1.8102 ns
DataHashFunctionCrc32	100	580.170 ns	51.8906 ns	2.8443 ns
NullFxCrc8	1000	1,848.433 ns	34.3229 ns	1.8814 ns
NullFxCrc16	1000	2,809.540 ns	93.3972 ns	5.1194 ns
NullFxCrc32	1000	2,507.788 ns	14.5636 ns	0.7983 ns
DataHashFunctionCrc8	1000	3,399.219 ns	770.8561 ns	42.2532 ns
DataHashFunctionCrc16	1000	5,151.755 ns	299.4059 ns	16.4114 ns
DataHashFunctionCrc32	1000	5,167.148 ns	146.2924 ns	8.0188 ns