# xsalsa20

XSalsa20 implemented in Javascript and WebAssembly.

```
npm install xsalsa20
```

[![build status](https://travis-ci.org/mafintosh/xsalsa20.svg?branch=master)](https://travis-ci.org/mafintosh/xsalsa20)


## Usage

``` js
var crypto = require('crypto')
var xsalsa20 = require('xsalsa20')
var key = crypto.randomBytes(32)
var nonce = crypto.randomBytes(24)

var xor = xsalsa20(nonce, key)

console.log(xor.update(Buffer.from('hello')))
console.log(xor.update(Buffer.from('world')))

xor.finalize()
```

## API

#### `var xor = xsalsa20(nonce, key)`

Create a new xor instance.

Nonce should be a 24 byte buffer/uint8array and key should be 32 bytes.

#### `var output = xor.update(input, [output])`

Update the xor instance with a new input buffer. Optionally you can pass in an output buffer.

#### `xor.finalize()`

Call this method last. Clears internal state.

## Contributing

The bulk of this module is implemented in WebAssembly in the [xsalsa20.wat](xsalsa20.wat) file. To build the thin Javascript wrapper do:

```
npm run compile
```

## License

MIT