ChainSafe ETH2.0 Projects

Note: There is a lot of work being done that are core infrastructural pieces for Eth2.0. Contributions to any of the below repositories would be greatly appreciated. All the libraries are written in TypeScript (or in the process of being converted from pure JS to TypeScript): -- PM / Meta Repo |-- Beacon Chain |-- Simple Serialize (SSZ) |-- Fixed Size Numbers |-- BLS Singatures and Signature Aggregation

ssz-js

Simple Serialize (SSZ) in pure Javascript

Install

npm install @chainsafesystems/ssz

Usage

See API.md for comprehensive API docs.

Serialize:

Array

let array = [1, 2, 3]
let serialized = ssz.serialize(array, ['uint16'])

Boolean

let bool = true
let serialized = ssz.serialize(bool, 'bool')

Number

let num = 16
let serialized = ssz.serialize(num, 'uint32')

Bytes

let bytes = Buffer.from([1,2,3])
let serialized = ssz.serialize(bytes, 'bytes')

We can also serialize to BytesN:

// Note: N === bytes.length
let arr = new Uint8Array(1)
let bytes = Buffer.from(arr.buffer)
let serialized = ssz.serialize(bytes, 'bytes1')

Object

let obj = {
	a: Buffer.from('hello'),
	b: 10,
	c: false
}

let types = {
	'fields' : [
		['a', 'bytes'],
		['b', 'int16'],
		['c', 'bool'],
	]
}

let serialized = ssz.serialize(obj, types)

Deserialize

For deserialization we need to specify:

• data {buffer} - encoded data
• type {string | object | array} - type of data we want to decode, same as encoding types
• start {number} - optional, default: 0, start location in the data buffer from where we wish to read

// eg. deserialize a boolean at position 0
ssz.deserialize(buf, 'bool')

// eg. deserialize an object at position 32
let types = {
    'fields' : [
        ['a', 'bool'],
        ['b', 'uint8']
    ]
}
ssz.deserialize(buf, types, 32)

Contributors

Very special thank you to Darren Langley for helping build this.