xsalsa20-encoding

xsalsa20-encoding

XSalsa20 codec that implements tha abstract-encoding interface.

Installation

$ npm install xsalsa20-encoding

Usage

const codec = require('xsalsa20-encoding')(nonce, secretKey)

// encode a value
buffer = codec.encode(value)

// decode a value
value = codec.decode(buffer)

Example

const crypto = require('crypto')
const Codec = require('xsalsa20-encoding')

const nonce = crypto.randomBytes(24)
const key = crypto.randomBytes(32)

const codec = Codec(nonce, key)
const hello = codec.encode('hello')
const world = codec.encode('world')

console.log('%s %s', codec.decode(hello), codec.decode(world)) // 'hello world'

Custom Value Encodings

const pbs = require('protocol-buffers')
const { Message } = pbs(`
message {
  string data = 1;
}
`)

const codec = Codec(nonce, key, { valueEncoding: Message })
const encoded = codec.encode({ data: 'hello world' })
const message = codec.decode(encoded) // { data: 'hello world' }

API

codec = require('xsalsa20-encoding')([nonce,] secretKey[, opts])

Create a codec object from a 24 byte nonce and 32 byte secretKey. If only a 32 byte nonce is given, it is treated as a secretKey.

const nonce = crypto.randomBytes(24)
const key = crypto.randomBytes(32)
const codec = Codec(nonce, key)

or

const key = crypto.randomBytes(32)
const codec = Codec(key)

buffer = codec.encode(value[, output[, offset]])

Encode a value using xsalsa20 (XOR) into an optional output buffer at an optional offset defaulting to 0. If an output buffer is not given, one is allocated for you and returned.

const buffer = codec.encode('hello world')

value = codec.decode(buffer[, offset])

Decode a buffer using xsalsa20 (XOR) at an optional offset defaulting to 0.

const value = codec.decode(buffer)

length = codec.encodingLength(value)

Returns the encoding length for a given value.

const length = codec.encodingLength('hello world') // 11

License

MIT