Node.js cipher.update() Method

The cipher.update() method is an inbuilt application programming interface of class Cipher within crypto module which is used to update the cipher with data according to the given encoding format.

Syntax:

const cipher.update(data[, inputEncoding][, outputEncoding])

Parameters: This method takes the following parameter:

• data: It is used to update the cipher by new content.
• inputEncoding: Input encoding format.
• outputEncoding: Output encoding format.

Return Value: This method returns the object of buffer containing the cipher value.

Example 1: Filename: index.js

Javascript

// Node.js program to demonstrate the
// cipher.update() method

// Importing crypto module
const crypto = require('crypto');

// Creating and initializing algorithm and password
const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// Getting key for the cipher object
const key = crypto.scryptSync(password, 'salt', 24);

// Creating and initializing the static iv
const iv = Buffer.alloc(16, 0);

// Creating and initializing the cipher object
const cipher = crypto.createCipheriv(algorithm, key, iv);

// Updating the cipher with the data
// by using update() method
let encrypted = cipher.update(
    'some clear text data', 'utf8', 'hex');

// Getting the buffer data of cipher
encrypted += cipher.final('hex');

// Display the result
console.log(encrypted);

Output:

e5f79c5915c02171eec6b212d5520d44480993d7d622a7c4c2da32f6efda0ffa

Example 2: Filename: index.js

Javascript

// Node.js program to demonstrate the
// cipher.update() method

// Importing crypto module
const crypto = require('crypto');

// Creating and initializing algorithm and password
const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// Getting key for cipher object
crypto.scrypt(password, 'salt', 24,
    { N: 512 }, (err, key) => {
        if (err) throw err;

        // Creating and initializing the static iv
        const iv = Buffer.alloc(16, 0);

        // Creating and initializing the cipher object
        const cipher = crypto
            .createCipheriv(algorithm, key, iv);

        // Updating the cipher with the data
        // by using update() method
        let encrypted = cipher.update(
            'some clear text data', 'utf8', 'hex');

        // Getting the buffer data of cipher
        encrypted += cipher.final('hex');

        // Display the result
        console.log(encrypted);
    });

Output:

5850288b1848440f0c410400403f7b456293229b5231c17d2b83b602f252714b

Run the index.js file using the following command:

node index.js

Reference: https://nodejs.org/dist/latest-v12.x/docs/api/crypto.html#crypto_cipher_update_data_inputencoding_outputencoding