eas

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

const AppendInitVect = require('./AppendInitVect');
// const getCipherKey = require('./getCipherKey');

function getCipherKey(password) {
    return crypto.createHash('sha256').update(password).digest();
  }

function encrypt({ file, password }) {
  // Generate a secure, pseudo random initialization vector.
  const initVect = crypto.randomBytes(16);

  // Generate a cipher key from the password.
  const CIPHER_KEY = getCipherKey(password);
  const readStream = fs.createReadStream(file);
  const gzip = zlib.createGzip();
  const cipher = crypto.createCipheriv('aes256', CIPHER_KEY, initVect);
  const appendInitVect = new AppendInitVect(initVect);
  // Create a write stream with a different file extension.
  const writeStream = fs.createWriteStream(path.join(file + ".enc"));

  readStream
    .pipe(gzip)
    .pipe(cipher)
    .pipe(appendInitVect)
    .pipe(writeStream);
}

function decrypt({ file, password }) {
    // First, get the initialization vector from the file.
    const readInitVect = fs.createReadStream(file, { end: 15 });

    let initVect;
    readInitVect.on('data', (chunk) => {
      initVect = chunk;
    });

    // Once we’ve got the initialization vector, we can decrypt the file.
    readInitVect.on('close', () => {
      const cipherKey = getCipherKey(password);
      const readStream = fs.createReadStream(file, { start: 16 });
      const decipher = crypto.createDecipheriv('aes256', cipherKey, initVect);
      const unzip = zlib.createUnzip();
      const writeStream = fs.createWriteStream(file + '.unenc');

      readStream
        .pipe(decipher)
        .pipe(unzip)
        .pipe(writeStream);
    });
  }

  encrypt('./watermark.pdf', 'password')