CSharp-ChaCha20-NetStandard

Managed .Net (Standard 2.0, .NET 6 and .NET 8) compatible ChaCha20 cipher written in C#

Build status

Why?

Because I needed this for my personal project

Origin

Scott Bennett wrote C# implementation called ChaCha20-csharp, which works as base for my code. That is why the license is same for both projects

Documentation

Docs

How do I use this?

Either copy the CSChaCha20.cs to your project or use LibChaCha20 nuget package

Then do code like

using CSChaCha20;

byte[] mySimpleTextAsBytes = Encoding.ASCII.GetBytes("Plain text I want to encrypt");

// Do not use these key and nonce values in your own code!
byte[] key = new byte[32] { 142, 26, 14, 68, 43, 188, 234, 12, 73, 246, 252, 111, 8, 227, 57, 22, 168, 140, 41, 18, 91, 76, 181, 239, 95, 182, 248, 44, 165, 98, 34, 12 };
byte[] nonce = new byte[12] { 139, 164, 65, 213, 125, 108, 159, 118, 252, 180, 33, 88 };
uint counter = 1;

// Encrypt
ChaCha20 forEncrypting = new ChaCha20(key, nonce, counter);
byte[] encryptedContent = new byte[mySimpleTextAsBytes.Length];
forEncrypting.EncryptBytes(encryptedContent, mySimpleTextAsBytes);

// Decrypt
ChaCha20 forDecrypting = new ChaCha20(key, nonce, counter);
byte[] decryptedContent = new byte[encryptedContent.Length];
forDecrypting.DecryptBytes(decryptedContent, encryptedContent);

You can try out the code in .NET Fiddle

Test cases

You can run test cases by moving to tests folder and running following command

dotnet test

Benchmarks

You can run benchmarks (which compare this implementation to the original version) by moving to benchmarks folder and running following command

dotnet run -c Release

there are three different input sizes (64 bytes, 1024 bytes and 1 MiB) and comparisons are done between the original version (made by Scott Bennett) and this project

License

All the code is licensed under ISC License