encrypt-at-rest

Simple, secure, forward-proof encryption at rest for Node using AES 256 GCM, with support for multiple master encryption keys.

let encrypted = encrypt("something"); // returns base64 string
decrypt(encrypted); // "something"

Approach

• Secure: Uses AES 256 GCM (Galois Counter Mode) algorithm for encryption, an authenticated encryption mechanism, with a unique initialization vector (IV) for each encrypted value.

• Forward-proof: Each encrypted value contains all information needed to decrypt the value. The encryption key id, algorithm, IV, and authentication tag are all stored along with the encrypted value, so that decrypt() is able to work with multiple encryption keys.

• Simple: Both encrypt() / decrypt() only take one argument, making the library extremely simple to use.

Installation

npm i encrypt-at-rest --save

Usage

This master key will need to be populated on application startup using setEncryptionKey(base64EncodedMasterKey). The master key must be 32 bytes in length.

Create a master encryption key

npm run generate-encryption-key

{"id":"ee518f7a-d297-4130-9b71-c1b36e6de793","value":"poKsapwI6vBAA+gQdFrxbOauEL6yxYXjCmUPxtxdQ6k="}

Load a key into memory on application startup

const {
	loadKey,
} = require("encrypt-at-rest");

// example: the serialized encryption key is loaded via an environment variable
loadKey(process.env.MASTER_ENCRYPTION_KEY);

Use the key to encrypt/decrypt values

const {
	decrypt,
	encrypt,
} = require("encrypt-at-rest");
const {
	strictEqual,
} = require("assert");

// Encrypt a value, e.g. before storing in database
const inputValue = "some valuable piece of information";
const encryptedValue = encrypt(inputValue);

// Decrypt a value, e.g. when pulling out of database
strictEqual(inputValue, decrypt(encryptedValue));

Load multiple keys

const {
	createKey,
	loadKey,
} = require("encrypt-at-rest");

// Encryption keys should be stored in and retrieved from a secure environment, e.g. AWS KMS,
// and loaded at runtime into the app.
let allKeys = await keysTable.fetchAll();
allKeys.forEach(keyRow => {
	const key = loadKey(createKey(keyRow.get("id"), keyRow.get("value"));
	if (keyRow.get("is_current")) {
		key.markCurrent();
	}
});

Contributing

This repo intentionally has no dependencies to keep it as lightweight as possible, including dev dependencies.

Lint: npm i eslint -g && npm run lint

Test: npm test. Tests are written using native node assertions.