File Validation using MD5 and SHA-256 in Node.js

File Validation using MD5 and SHA-256 in Node.js

The Crypto Library in Node.js is a core module that offers cryptographic functionalities, including hashing algorithms like MD5 (Message Digest Algorithm 5) and SHA-256 (Secure Hash Algorithm 256-bit). These algorithms are widely used for generating unique hash values from data.


When transmitting files over the internet or storing them on servers, ensuring data integrity is crucial. The Crypto Library can be utilized to generate hash values for files, allowing verification of their integrity at both ends.

Let's assume we have a file named "example.txt" with the following content:

Hello, this is an example file for file validation using Node.js Crypto Library!

We will calculate both MD5 and SHA-256 hashes for this file and then validate them.

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

// Function to calculate the hash of a file using a specific algorithm
function calculateHash(filePath, algorithm) {
  return new Promise((resolve, reject) => {
    const hash = crypto.createHash(algorithm);
    const stream = fs.createReadStream(filePath);

    stream.on('data', (data) => hash.update(data));
    stream.on('end', () => resolve(hash.digest('hex')));
    stream.on('error', (error) => reject(error));

// File path and algorithms
const filePath = './example.txt';
const md5HashPromise = calculateHash(filePath, 'md5');
const sha256HashPromise = calculateHash(filePath, 'sha256');

// Valid hash values (you can change these values for testing)
const validMD5Hash = '6cb4c9e3a7a126d0f09150b806533ff2';
const validSHA256Hash = '3b310c99b9c541c15f2a0b7edc1e9a6f218978671e1f4a9a013b82e3ee7a7b38';

Promise.all([md5HashPromise, sha256HashPromise])
  .then(([calculatedMD5Hash, calculatedSHA256Hash]) => {
    if (calculatedMD5Hash === validMD5Hash && calculatedSHA256Hash === validSHA256Hash) {
      console.log('File is valid. Hashes match!');
    } else {
      console.log('File is not valid. Hashes do not match!');
  .catch((error) => {
    console.error('Error calculating hash:', error);


By using the Crypto Library in Node.js, developers can easily calculate hash values for files, such as MD5 and SHA-256, to verify their integrity during transmission or storage. This helps ensure that files remain unchanged and have not been tampered with.