Encrypting & Decrypting

Encrypt with createCipheriv

Node allows for creating a cipher, which are encryption algorithms. Using the provided function, createCipheriv, returns an objects that can be used to encrypt data.

Decrypt with createDecipheriv

Node also allows for creating a decipher, which can be used to "decrypt" an encrypted value.

Key details that matter when encrypting and decrypting are:

• both must take the same encryption algorithm when creating the objects (createCipheriv, createDecipheriv)
• both must take the same "key" when creating the objects (createCipheriv, createDecipheriv)
• both must take the same "initializationVector" when creating the objects (createCipheriv, createDecipheriv)
• both leverage the "update" and "final" methods, where data + input encoding + output encoding can get passed to the update method, and output encoding get passed to the final method

const { createCipheriv, createDecipheriv, randomBytes } = require("crypto");

const envryptionAlgorithm = "aes-256-cbc"; 
const random16Bytes = randomBytes(16);
const random32Bytes = randomBytes(32);

// protected data
const message = "This is a secret message";

// encrypt
const cipher = createCipheriv(envryptionAlgorithm, random32Bytes, random16Bytes);
// decrypt
const decipher = createDecipheriv(envryptionAlgorithm, random32Bytes, random16Bytes);

// encrypt the message
let encryptedData = cipher.update(message, "utf-8", "hex");
encryptedData += cipher.final("hex");
console.log(`Encrypted message: ${encryptedData}`);


// decrypt
let decryptedData = decipher.update(encryptedData, "hex", "utf-8")
decryptedData += decipher.final("utf8");
console.log(`Decrypted message: ${decryptedData}`);