jcc-blockchain/scripts/generate-static-keys-run.js

const { createHash } = require('crypto');
const fs = require('fs');
const path = require('path');

let secp256k1 = null;
let keccak256 = null;
let RLP = null;

try {
  ({ secp256k1 } = require('ethereum-cryptography/secp256k1'));
  ({ keccak256 } = require('ethereum-cryptography/keccak'));
  RLP = require('@ethereumjs/rlp').RLP;
} catch (e) {
  console.error('ERROR: key generation deps not available.');
  console.error('Run: npm install ethereum-cryptography @ethereumjs/rlp');
  process.exit(1);
}

function derivePrivateKey(seed, label) {
  let buf = Buffer.from(`${seed}-${label}`, 'utf8');
  for (let i = 0; i < 1000; i++) buf = createHash('sha256').update(buf).digest();
  return '0x' + buf.toString('hex');
}

function seedToBuffer(s) {
  if (typeof s === 'string') return Buffer.from(s.slice(2), 'hex');
  return s;
}

function privateKeyToAddress(privKey) {
  const pub = secp256k1.getPublicKey(seedToBuffer(privKey), false);
  const pubNoHeader = pub.slice(1); // 64 bytes
  const hash = keccak256(pubNoHeader);
  return '0x' + Buffer.from(hash).subarray(-20).toString('hex');
}

function padHexTo(s, n) {
  s = s.startsWith('0x') ? s.slice(2) : s;
  return s.padStart(n * 2, '0');
}

const seed = process.env.DEVNET_SEED || 'jcc-devnet-v1';
const outDir = process.argv[2] || path.join(__dirname, '..', 'devnet');

// Node.js util for hex bytes to Buffer
function hexToBuf(hex) {
  return Buffer.from(hex.startsWith('0x') ? hex.slice(2) : hex, 'hex');
}

const validators = [];
for (let i = 1; i <= 3; i++) {
  const priv = derivePrivateKey(seed, `validator-${i}`);
  const addr = privateKeyToAddress(priv);
  validators.push({ name: `validator${i}`, privateKey: priv, address: addr });
}

// Write key files
for (const v of validators) {
  const dir = path.join(outDir, 'validator-keys', v.name);
  fs.mkdirSync(dir, { recursive: true });
  fs.writeFileSync(path.join(dir, 'key'), v.privateKey.slice(2), 'utf8');
  fs.writeFileSync(path.join(dir, 'address'), v.address, 'utf8');
  const pub = secp256k1.getPublicKey(seedToBuffer(v.privateKey), false);
  fs.writeFileSync(path.join(dir, 'key.pub'), Buffer.from(pub).toString('hex'), 'utf8');
}

// Build extraData via RLP
const encodedValidators = validators.map(v => hexToBuf(padHexTo(v.address, 20)));
const extraDataItems = [
  Buffer.alloc(32, 0), // vanity
  encodedValidators,
  [], // vote
  Buffer.alloc(8, 0), // round
  [] // seals
];
const extraData = '0x' + Buffer.from(RLP.encode(extraDataItems)).toString('hex');

// Build allocations
const alloc = {};
for (const v of validators) {
  alloc[v.address.slice(2)] = { comment: v.name, balance: '0xad78ebc5ac6200000' };
}
alloc['f39Fd6e51aad88F6F4ce6aB8827279cffFb92266'] = { comment: 'Anvil default #0', balance: '0x56bc75e2d63100000' };

const genesis = {
  config: {
    chainId: 1337,
    homesteadBlock: 0,
    eip150Block: 0,
    eip150Hash: '0x' + '00'.repeat(32),
    eip155Block: 0,
    eip158Block: 0,
    byzantiumBlock: 0,
    constantinopleBlock: 0,
    petersburgBlock: 0,
    istanbulBlock: 0,
    muirGlacierBlock: 0,
    berlinBlock: 0,
    londonBlock: 0,
    zeroBaseFee: true,
    ibft2: {
      blockperiodseconds: 2,
      epochlength: 30000,
      requesttimeoutseconds: 4,
      blockreward: '0x0',
      miningbeneficiary: '0x' + '00'.repeat(20)
    }
  },
  nonce: '0x0',
  timestamp: '0x' + Math.floor(Date.now() / 1000).toString(16),
  gasLimit: '0x1fffffffffffff',
  difficulty: '0x1',
  mixHash: '0x63746963616c2062797a616e74696e65206661756c7420746f6c6572616e6365',
  coinbase: '0x' + '00'.repeat(20),
  alloc,
  extraData
};

fs.writeFileSync(path.join(outDir, 'besu-config', 'genesis.json'), JSON.stringify(genesis, null, 2), 'utf8');

const summary = { seed, validators, extraData, genesisFile: 'besu-config/genesis.json' };
fs.writeFileSync(path.join(outDir, 'besu-config', 'nodes-summary.json'), JSON.stringify(summary, null, 2), 'utf8');

console.log('Devnet config generated successfully.');
console.log(JSON.stringify(summary, null, 2));