Snowstorm

A minimalistic encryption protocol for rust async streams / packets, based on noise protocol and snow.

Quickstart

Snowstorm allows you to secure any streams implemented AsyncRead + AsyncWrite + Unpin. For example, TcpStream in Tokio. Note that the underlying connections need to be reliable.

Create a Key Pair

// Noise protocol params, see: http://www.noiseprotocol.org/noise.html#protocol-names-and-modifiers
// Use `KK` to enable bidirectional identity verification
static PATTERN: &str = "Noise_KK_25519_ChaChaPoly_BLAKE2s"; 

// Generate a private / public key pair
let key_pair = snowstorm::Builder::new(PATTERN.parse()?).generate_keypair().unwrap()

Client

// Connect to the peer
let stream = TcpStream::connect("127.0.0.1:12345").await?;

// The client should build an initiator to launch the handshake process
let initiator = snowstorm::Builder::new(PATTERN.parse()?)
    .local_private_key(local_private_key)
    .remote_public_key(remote_public_key)
    .build_initiator()?;

// Start handshaking
let mut secured_stream = NoiseStream::handshake(stream, initiator).await?;

// A secured stream `NoiseStream<T>` will be return once the handshake is done
secured_stream.write_all(b"hello world").await?;

Server

// Accept a `TcpStream` from the listener
let listener = TcpListener::bind("127.0.0.1:12345").await?;
let (stream, _) = listener.accept().await?;

// The server needs a responder to handle handshake reqeusts from clients
let responder = snowstorm::Builder::new(PATTERN.parse()?)
    .local_private_key(local_private_key)
    .remote_public_key(remote_public_key)
    .build_responder()?;

// Start handshaking
let mut secured_stream = NoiseStream::handshake(stream, responder).await?;

let mut buf = [0; 1024];
secured_stream.read(&mut buf).await?;

Spec

Stream

[ length (2 bytes, little endian) ] [ noise message (length bytes) ]

Packet

[ nonce (8 bytes) ] [ noise message ]

Todo

• UDP Support
• Documentation
• Benchmarks
• Async-std support