@gotbit/merkle

Library for work with Merkle Tree Was choosen sorted version of Merkle Tree, with keccak256 hash function from ethers.js

Features

• Calculate root from raw leaves
• Generate proofs
• Verify proof

Examples

Root

Calculation of root for Merkle tree you need to prepare array of leaves (hashed values)

import { calculateRoot } from '@gotbit/merkle'

const leaves = [
  '0xbc45a2b14ce263793725c93e12afa83d2cc6312b9abe44ed06fb66afd4394175',
  '0x67cdf3d02c0c38e81f3def6251132aaae3d70cd50a1639b039b3c87c99a6092b',
  '0x85e0c2c66b77fed6c821710352651309dc3792db7db10788af32daa42706a527',
  '0xdb5425be7bb655e161ff2939dfe331a07c16e42933b133c624d1dce76f66fb6b',
]

const root = calculateRoot(leaves)

Proof

Generation of proof for specific leafe

import { generateProof } from '@gotbit/merkle'

const leaves = [
  '0xbc45a2b14ce263793725c93e12afa83d2cc6312b9abe44ed06fb66afd4394175',
  '0x67cdf3d02c0c38e81f3def6251132aaae3d70cd50a1639b039b3c87c99a6092b',
  '0x85e0c2c66b77fed6c821710352651309dc3792db7db10788af32daa42706a527',
  '0xdb5425be7bb655e161ff2939dfe331a07c16e42933b133c624d1dce76f66fb6b',
]

const i = 0
const proof = generateProof(leaves, leaves[i]) // generates proof for i-leaf

Verify

To verify correctness of proof you can use typescript or make on-chain with Merkle solidity library

Typescript

import { generateProof, calculateRoot, verify } from '@gotbit/merkle'

const leaves = [
  '0xbc45a2b14ce263793725c93e12afa83d2cc6312b9abe44ed06fb66afd4394175',
  '0x67cdf3d02c0c38e81f3def6251132aaae3d70cd50a1639b039b3c87c99a6092b',
  '0x85e0c2c66b77fed6c821710352651309dc3792db7db10788af32daa42706a527',
  '0xdb5425be7bb655e161ff2939dfe331a07c16e42933b133c624d1dce76f66fb6b',
]

const root = calculateRoot(leaves)

const index = 0
const proof = generateProof(leaves, leaves[index]) // generates proof for i-leaf

const result = verify(proof, root, leaves[index]) // return `true` if proof is correct

Solidity

import "@gotbit/merkle/contracts/Merkle.sol";

contract Vesting {
  using Merkle for bytes32[];

  bytes32 ROOT;

  function verify(bytes32[] memory proof) external {
    bytes32 leaf = abi.encode(msg.sender);
    require(proof.verify(ROOT, leaf), 'Incorrect proof');
  }
}