/**
* An example for synchronous encryption and decryption of a String with password derived key featuring:
* - An out of the box working Example
* - Generation of a random password
* - derivation of a key
* - Utf8 Encoding of Strings
* - Base64 String encoding of byte-Arrays
* - Logging of exceptions
*/
var crypto = require("crypto"),
winston = require("winston");
const logger = winston.createLogger({
format: winston.format.combine(
winston.format.splat(),
winston.format.simple()
),
transports: [
new winston.transports.Console({
format: winston.format.simple(),
handleExceptions: true
})
]
});
const demonstratePasswordBasedSymmetricEncryption = () => {
try {
// replace with your actual String
let exampleString =
"Text that is going to be sent over an insecure channel and must be encrypted at all costs!";
// the password used for derviation of a key, assign your password here
// if none is assigned a random one is generated
let password = null;
if (password === null) {
password = crypto.randomBytes(48).toString("utf8");
}
// derive key with password and salt
// keylength adheres to the "ECRYPT-CSA Recommendations" on "www.keylength.com"
let salt = crypto.randomBytes(128);
let derivedKey = crypto.pbkdf2Sync(password, salt, 10000, 32, "sha256");
// create random initialization vector
let iv = crypto.randomBytes(16);
// encrypt the Text
let cipher = crypto.createCipheriv("aes-256-gcm", derivedKey, iv);
let encrypted = cipher.update(exampleString, "utf8", "base64");
encrypted += cipher.final("base64");
let authTag = cipher.getAuthTag();
// decrypt the Text
let decipher = crypto.createDecipheriv("aes-256-gcm", derivedKey, iv);
decipher.setAuthTag(authTag);
let decrypted = decipher.update(encrypted, "base64", "utf8");
decrypted += decipher.final("utf8");
logger.info(
"Decrypted String and original String are the same: %s",
exampleString.localeCompare(decrypted) === 0 ? "yes" : "no"
);
} catch (error) {
logger.error(error.message);
}
};
demonstratePasswordBasedSymmetricEncryption();
// for unit testing purposes
module.exports = { demonstratePasswordBasedSymmetricEncryption, logger };