@web4/secret-stream

Secret stream backed by Noise and libsodium's secretstream

npm install @web4/secret-stream

Usage

You can either make a secret stream from an existing transport stream.

const SecretStream = require('@web4/secret-stream')

const a = new SecretStream(true, tcpClientStream)
const b = new SecretStream(false, tcpServerStream)

// pipe the underlying rawstreams together

a.write(Buffer.from('hello encrypted!'))

b.on('data', function (data) {
  console.log(data) // <Buffer hello encrypted!>
})

Or by making your own pipeline

const a = new SecretStream(true)
const b = new SecretStream(false)

// pipe the underlying rawstreams together
a.rawStream.pipe(b.rawStream).pipe(a.rawStream)

a.write(Buffer.from('hello encrypted!'))

b.on('data', function (data) {
  console.log(data) // <Buffer hello encrypted!>
})

API

const s = new SecretStream(isInitiator, [rawStream], [options])

Make a new stream. isInitiator is a boolean indication whether you are the client or the server. rawStream can be set to an underlying transport stream you want to run the noise stream over.

Options include:

{
  pattern: 'XX', // which noise pattern to use
  remotePublicKey, // set if your handshake requires it
  keyPair: { publicKey, secretKey },
  handshake: { // if you want to use an handshake performed elsewhere pass it here
    tx,
    rx,
    handshakeHash,
    publicKey,
    remotePublicKey
  }
}

The SecretStream returned is a Duplex stream that you use as as normal stream, to write/read data from, except it's payloads are encrypted using the libsodium secretstream.

Note that this uses ed25519 for the handshakes per default.

If need to load the key pair asynchronously, then secret-stream also supports passing in a promise instead of the keypair that later resolves to { publicKey, secretKey }. The stream lifecycle will wait for the resolution and auto destroy the stream if the promise errors.

s.start(rawStream, [options])

Start a SecretStream from a rawStream asynchrously.

const s = new SecretStream({
  autoStart: false // call start manually
})

// ... do async stuff or destroy the stream

s.start(rawStream, {
  ... options from above
})

keyPair = SecretStream.keyPair([seed])

Generate a ed25519 key pair.

s.publicKey

Get the local public key.

s.remotePublicKey

Get the remote's public key. Populated after open is emitted.

s.handshakeHash

Get the unique hash of this handshake. Populated after open is emitted.

s.on('connect', onconnect)

Emitted when the handshake is fully done. It is safe to write to the stream immediately though, as data is buffered internally before the handshake has been completed.

License

MIT