passport-cookie-session/src/utils/encryption.js

Encrypted, cookie-based session middleware compatible with PassportJS

const crypto = require('crypto');
const { ALGORITHM, IV_LENGTH, TAG_LENGTH } = require('../constants');

async function encryptPassport(data, signingKey) {
  const iv = crypto.randomBytes(IV_LENGTH);
  const key = crypto.createHash('sha256').update(signingKey).digest();
  const cipher = crypto.createCipheriv(ALGORITHM, key, iv);

  const encrypted = Buffer.concat([
    cipher.update(data, 'utf8'),
    cipher.final()
  ]);

  const tag = cipher.getAuthTag();
  const result = Buffer.concat([iv, tag, encrypted]).toString('base64');

  return result;
}

async function decryptPassport(data, signingKey) {
  const buffer = Buffer.from(data, 'base64');
  const iv = buffer.subarray(0, IV_LENGTH);
  const tag = buffer.subarray(IV_LENGTH, IV_LENGTH + TAG_LENGTH);
  const encrypted = buffer.subarray(IV_LENGTH + TAG_LENGTH);

  const key = crypto.createHash('sha256').update(signingKey).digest();
  const decipher = crypto.createDecipheriv(ALGORITHM, key, iv);
  decipher.setAuthTag(tag);

  const decrypted = Buffer.concat([
    decipher.update(encrypted),
    decipher.final()
  ]);

  return decrypted.toString('utf8');
}

module.exports = { encryptPassport, decryptPassport };