multibase

What is multibase?

The 'multibase' npm package provides a way to encode and decode data using various base encoding schemes. It supports a wide range of base encodings, making it useful for applications that need to handle data in different formats.

What are multibase's main functionalities?

Encoding Data

This feature allows you to encode data using a specified base encoding. In this example, the data 'hello world' is encoded using base32.

const multibase = require('multibase');
const data = Buffer.from('hello world');
const encoded = multibase.encode('base32', data);
console.log(encoded.toString());

Decoding Data

This feature allows you to decode data that has been encoded with a base encoding. In this example, the base32 encoded string 'bnbswy3dpeb3w64tmmq' is decoded back to 'hello world'.

const multibase = require('multibase');
const encoded = 'bnbswy3dpeb3w64tmmq';
const decoded = multibase.decode(encoded);
console.log(decoded.toString());

Listing Supported Encodings

This feature provides a list of all supported base encodings. It can be useful to know which encodings are available for use.

const multibase = require('multibase');
const encodings = multibase.names;
console.log(encodings);

Other packages similar to multibase

base-x

The 'base-x' package provides a way to encode and decode data using custom base encodings. It is similar to 'multibase' but focuses on custom base encodings rather than a predefined set of encodings.

base64-js

The 'base64-js' package is specifically designed for base64 encoding and decoding. It is more specialized compared to 'multibase', which supports a wider range of encodings.

bs58

The 'bs58' package provides base58 encoding and decoding. It is similar to 'multibase' in that it handles base encodings, but it is specialized for base58.

README

js-multibase

JavaScript implementation of the multibase specification

Lead Maintainer

Oli Evans

Table of Contents

• Install
  • In Node.js through npm
  • Browser: Browserify, Webpack, other bundlers
  • In the Browser through <script> tag
    • Gotchas
• Usage
  • Example
• API
  • multibase - Prefixes an encoded buffer with its multibase code
  • multibase.encode - Encodes a buffer into one of the supported encodings, prefixing it with the multibase code
  • multibase.decode - Decodes a buffer or string
  • multibase.isEncoded - Checks if buffer or string is encoded
  • multibase.names - Supported base encoding names
  • multibase.codes - Supported base encoding codes
  • Supported Encodings, see src/constants.js
• Architecture and Encoding/Decoding
• Adding additional bases
• License

Install

In Node.js through npm

> npm install --save multibase

Browser: Browserify, Webpack, other bundlers

The code published to npm that gets loaded on require is in fact an ES5 transpiled version with the right shims added. This means that you can require it and use with your favourite bundler without having to adjust asset management process.

const multibase = require('multibase')

In the Browser through <script> tag

Loading this module through a script tag will make the Multibase obj available in the global namespace.

<script src="https://unpkg.com/multibase/dist/index.min.js"></script>
<!-- OR -->
<script src="https://unpkg.com/multibase/dist/index.js"></script>

Usage

Example

const { Buffer } = require('buffer')
const multibase = require('multibase')

const encodedBuf = multibase.encode('base58btc', new Buffer('hey, how is it going'))

const decodedBuf = multibase.decode(encodedBuf)
console.log(decodedBuf.toString())
// hey, how is it going

API

https://multiformats.github.io/js-multibase/

multibase - Prefixes an encoded buffer with its multibase code

const multibased = multibase(<nameOrCode>, encodedBuf)

multibase.encode - Encodes a buffer into one of the supported encodings, prefixing it with the multibase code

const encodedBuf = multibase.encode(<nameOrCode>, <buf>)

multibase.decode - Decodes a buffer or string

const decodedBuf = multibase.decode(bufOrString)

multibase.isEncoded - Checks if buffer or string is encoded

const value = multibase.isEncoded(bufOrString)
// value is the name of the encoding if it is encoded, false otherwise

multibase.names

A frozen Array of supported base encoding names.

multibase.codes

A frozen Array of supported base encoding codes.

Supported Encodings, see src/constants.js

Architecture and Encoding/Decoding

Multibase package defines all the supported bases and the location of their implementation in the constants.js file. A base is a class with a name, a code, an implementation and an alphabet.

class Base {
  constructor (name, code, implementation, alphabet) {
    //...
  }
  // ...
}

The implementation is an object where the encoding/decoding functions are implemented. It must take one argument, (the alphabet) following the base-x module architecture.

The alphabet is the ordered set of defined symbols for a given base.

The idea behind this is that several bases may have implementations from different locations/modules so it's useful to have an object (and a summary) of all of them in one location (hence the constants.js).

All the supported bases are currently using the npm base-x module as their implementation. It is using bitwise maipulation to go from one base to another, so this module does not support padding at the moment.

Adding additional bases

If the base you are looking for is not supported yet in js-multibase and you know a good encoding/decoding algorithm, you can add support for this base easily by editing the constants.js file (you'll need to create an issue about that beforehand since a code and a canonical name have to be defined):

const baseX = require('base-x')
//const newPackage = require('your-package-name')

const constants = [
  ['base2', '0', baseX, '01'],
  ['base8', '7', baseX, '01234567'],
  // ... [ 'your-base-name', 'code-to-be-defined', newPackage, 'alphabet']
]

The required package defines the implementation of the encoding/decoding process. It must comply by these rules :

• encode and decode functions with to-be-encoded buffer as the only expected argument
• the require call use the alphabet given as an argument for the encoding/decoding process

If no package is specified , it means the base is not implemented yet

Adding a new base requires the tests to be updated. Test files to be updated are :

• constants.spec.js

describe('constants', () => {
  it('constants indexed by name', () => {
    const names = constants.names
    expect(Object.keys(names).length).to.equal(constants-count) // currently 12
  })

  it('constants indexed by code', () => {
    const codes = constants.codes
    expect(Object.keys(codes).length).to.equal(constants-count)
  })
})

• multibase.spec.js
  • if the base is implemented

  const supportedBases = [
    ['base2', 'yes mani !', '01111001011001010111001100100000011011010110000101101110011010010010000000100001'],
    ['base8', 'yes mani !', '7171312714403326055632220041'],
    ['base10', 'yes mani !', '9573277761329450583662625'],
    // ... ['your-base-name', 'what you want', 'expected output']
  

  • if the base is not implemented yet

  const supportedBases = [
    // ... ['your-base-name']
  

Contribute

Contributions welcome. Please check out the issues.

Check out our contributing document for more information on how we work, and about contributing in general. Please be aware that all interactions related to multiformats are subject to the IPFS Code of Conduct.

Small note: If editing the README, please conform to the standard-readme specification.

License

MIT © Protocol Labs Inc.