Encrypting to a file instead of to string.

encrypToFile.js

/*
 * Encryption function.
 *
 * @param {string} fileName Name of the file to encrypt.
 */
async function encrypt(fileName){
  const encryptParams = new Virtru.EncryptParamsBuilder()
    .withFileSource(`./encrypt-in/${fileName}`)
    .withDisplayfileName(fileName)
    .build();
  ct = await client.encrypt(encryptParams);
  
  //var ctString = await ct.toString();    
  
  await ct.toFile(`./encrypt-out/${fileName}`);  // Encrypt directly to file instead of string.
}