NullFX.CRC 1.1.8

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 PROJECT package NullFX.CRC --version 1.1.8

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