@trade-quorum/tq-helpers/src/crypto-helpers.js

Various common helpers for Trade Quorum API/App

const crypto = require('crypto');
const fs = require('fs');

exports.getFileHash = (filename, algorithm, callback) => {
  const hash = crypto.createHash('sha256');
  const stream = fs.createReadStream(filename);

  stream.on('error', (err) => {
    callback(err, null);
  });

  stream.on('data', (data) => {
    hash.update(data);
  });

  stream.on('end', () => {
    callback(null, hash.digest('hex'));
  });
};