xchacha20-poly1305

README

XChaCha20-Poly1305

A fully RFC 8439 and RFC draft-irtf-cfrg-xchacha-03 compliant implementation of the XChaCha20-Poly1305 AEAD algorithm.

XChaCha20-Poly1305 combines the ChaCha20 stream cipher with the Poly1305 message authentication code (MAC).

Both components and their extensions were implemented as self-contained units, so you can e.g. use ChaCha20 without Poly1305 if you want to.

Looking into the tests you'll find full coverage of all RFC test vectors which makes this implementation compliant with both RFCs.

Note: While you could in theory use these implementations as drop-in replacements, you probably shouldn't. The code was written for educational purposes and is therefore neither optimized (e.g. to combat timing attacks), nor audited.

Setup

1. git clone <url>
2. asdf install
3. go test -race ./...
4. go run ./cmd/cli/main.go

Primitives

Stream Cipher

The ChaCha20 stream cipher and its variant XChaCha20 (with HChaCha20).

Message Authenticate Code

The Poly1305 message authentication code (MAC).

Authenticated Encryption with Associated Data

The ChaCha20-Poly1305 AEAD construction alongside its variant XChaCha20-Poly1305.

Useful Commands

go run <package-path>
go build [<package-path>]

go test [<package-path>][/...] [-v] [-cover] [-race] [-parallel <number>]
go test -bench=. [<package-path>] [-count <number>] [-benchmem] [-benchtime 2s] [-memprofile <name>]

go test -coverprofile <name> [<package-path>]
go tool cover -html <name>
go tool cover -func <name>

go doc [<package-path>]
go fmt [<package-path>]
go vet [<package-path>]

go mod init [<module-path>]
go mod tidy
go mod vendor
go mod download

go work init [<module-path-1> [<module-path-2>] [...]]
go work use [<module-path-1> [<module-path-2>] [...]]
go work sync

# Adjust dependencies in `go.mod`.
go get <package-path>[@<version>]

# Build and install commands.
go install <package-path>[@<version>]

go list -m [all]

Useful Resources

• Go - Learn
• Go - Documentation
• Go - A Tour of Go
• Go - Effective Go
• Go - Playground
• Go by Example
• 100 Go Mistakes and How to Avoid Them