ChaCha20.NetCore

Implementation of chacha20 cipher, designed by D. J. Bernstein. Optimized for PinnedMemory.

Install

From a command prompt

dotnet add package ChaCha20.NetCore

Install-Package ChaCha20.NetCore

You can also search for package via your nuget ui / website:

https://www.nuget.org/packages/ChaCha20.NetCore/

Examples

You can find more examples in the github examples project.

var iv = new byte[16];
var key = new byte[32];

using var provider = new RNGCryptoServiceProvider();
provider.GetBytes(iv);
provider.GetBytes(key);

using var keyPin = new PinnedMemory<byte>(key, false);
using var cipher = new ChaCha20(keyPin, iv);
cipher.UpdateBlock(new PinnedMemory<byte>(new byte[] {63, 61, 77, 20, 63, 61, 77, 20, 63, 61, 77}, false), 0, 11); // caw caw caw in utf8

using var output = new PinnedMemory<byte>(new byte[cipher.GetLength()]);
cipher.DoFinal(output, 0);

Constructor

ChaCha20(PinnedMemory<byte> key, byte[] iv, int rounds = 20)

Methods

Get the cipher output length.

int GetLength()

Update the cipher with a single byte.

void Update(byte input)

Update the cipher with a pinned memory byte array.

void UpdateBlock(PinnedMemory<byte> input, int inOff, int len)

Update the cipher with a byte array.

void UpdateBlock(byte[] input, int inOff, int len)

Produce the final cipher outputting to pinned memory. Key & iv remain until dispose is called.

void DoFinal(PinnedMemory<byte> output, int outOff)

Reset the cipher back to it's initial state for further processing. Key & iv remain until dispose is called.

void Reset()

Clear key & iv, reset cipher back to it's initial state.

void Dispose()