npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

bitgesell-merkle-lib

v1.0.6

Published

A performance conscious library for merkle root and tree calculations for Bitgesell Blockchain network.

Downloads

23

Readme

bitgesell-merkle-lib

js-standard-style

A performance conscious library for merkle root and tree calculations for Bitgesell Blockchain Network.

Disclaimer

This implementation is vulnerable to a forgery attack as a second pre-image attack, see these[1][2] crypto.stackexchange questions for an explanation. To avoid this vulnerability, you should pre-hash your leaves using a different hash function than the function provided such that H(x) != H'(x).

Additionally, this implementation is vulnerable to a forgery attack for an unbalanced merkle tree, wherein, in an unbalanced merkle tree, the last leaf node can be duplicated to create an artificial balanced tree, resulting in the same root hash. To avoid this vulnerability [in this implementation], do not accept unbalanced merkle trees in your application.

Usage

Preamble

const crypto = require('crypto')

function sha256 (data) {
  return crypto.createHash('sha256').update(data).digest()
}

const data = [
  'cafebeef',
  'ffffffff',
  'aaaaaaaa',
  'bbbbbbbb',
  'cccccccc'
].map(x => new Buffer(x, 'hex'))

// ... now, the examples

Tree

const { merkleTree } = require('bitgesell-merkle-lib')
const tree = merkleTree(data, sha256)

console.log(tree.map(x => x.toString('hex')))
// => [
//  'cafebeef',
//  'ffffffff',
//  'aaaaaaaa',
//  'bbbbbbbb',
//  'cccccccc',
//  'bda5c39dec343da54ce91c57bf8e796c2ca16a1bd8cae6a2cefbdd16efc32578',
//  '8b722baf6775a313f1032ba9984c0dce32ff3c40d7a67b5df8de4dbaa43a3db0',
//  '3d2f424783df5853c8d7121b1371650c04241f318e1b0cd46bedbc805b9164c3',
//  'bb232963fd0efdeacb0fd76e26cf69055fa5facc19a5f5c2f2f27a6925d1db2f',
//  '2256e70bea2c591190a0d4d6c1415acd7458fae84d8d85cdc68b851da27777d4',
//  'c2692b0e127b3b774a92f6e1d8ff8c3a5ea9eef9a1d389fe294f0a7a2fec9be1'
//]

Root only (equivalent to tree[tree.length - 1])

const { 
  fastRoot, 
  verify
} = require('bitgesell-merkle-lib')

const root = fastRoot(data, sha256)

console.log(root.toString('hex'))
// => 'c2692b0e127b3b774a92f6e1d8ff8c3a5ea9eef9a1d389fe294f0a7a2fec9be1'

Proof (with verify)

const {merkleProof} = require('bitgesell-merkle-lib')
const proof = merkleProof(tree, data[0])

if (proof === null) {
  console.error('No proof exists!')
}

console.log(proof.map(x => x && x.toString('hex')))
// => [
//   'cafebeef',
//   'ffffffff',
//   null,
//   '8b722baf6775a313f1032ba9984c0dce32ff3c40d7a67b5df8de4dbaa43a3db0',
//   null,
//   '2256e70bea2c591190a0d4d6c1415acd7458fae84d8d85cdc68b851da27777d4',
//   'c2692b0e127b3b774a92f6e1d8ff8c3a5ea9eef9a1d389fe294f0a7a2fec9be1'
// ]

console.log(verify(proof, sha256))
// => true

API

For an indepth documentation refer to docs also see usage for practical usage.

Tests

To run tests,

npm install
npm run unit

Credits

Thanks to Meni Rosenfield on bitcointalk for the math.