Crypto Module in Node.js

The Node.js crypto module provides cryptographic functionality used to secure data and protect information in applications and network communications.

• The crypto module is used to perform cryptographic operations in Node.js.
• Cryptography is an important part of network security.
• Cryptography refers to the science of secret writing used to keep data confidential.

    // 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);
    
    // Getting buffer value
    // by using final() method
    let value = cipher.final('hex');
    
    // Display the result
    console.log("buffer :- " + value);

Output:

buffer :- b9be42878310d599e4e49e040d1badb9

Methods of the Node.js Crypto Module

The Complete List of crypto module are listed below:

1. Cipher Methods

These methods are used to perform encryption operations using a cipher object.

• cipher.final(): cipher.final() returns the buffer containing the final encrypted data of the cipher object.
• cipher.update(): cipher.update() updates the cipher with data according to the given encoding format.

2. Decipher Methods

These methods are used to decrypt encrypted data using a decipher object.

• decipher.update(): decipher.update() updates the decipher with encrypted data according to the encoding format.
• decipher.final():  decipher.final() returns the buffer containing the final decrypted value of the decipher object.

3. Cipher and Decipher Creation

These methods are used to create objects required for performing encryption and decryption.

• crypto.createCipheriv(): crypto.createCipheriv() creates a Cipher object using a specified algorithm, key, and initialization vector.
• crypto.createDecipheriv(): crypto.createDecipheriv() creates a Decipher object using a specified algorithm, key, and initialization vector.

4. Encryption and Decryption

These methods are used to encrypt and decrypt data using public and private keys.

• crypto.publicEncrypt(): crypto.publicEncrypt() encrypts data using a public key.
• crypto.privateDecrypt(): crypto.privateDecrypt() decrypts data using a private key.
• crypto.privateEncrypt(): crypto.privateEncrypt() encrypts data using a private key.
• crypto.publicDecrypt(): crypto.publicDecrypt() decrypts data using a public key.

5. Hashing and Message Authentication

These methods are used to generate secure hashes and message authentication codes.

• crypto.createHash(): crypto.createHash() creates a hash object used to generate hash digests using a specified algorithm.
• crypto.createHmac(): crypto.createHmac() creates an HMAC object using a given algorithm and secret key.
• crypto.getHashes(): crypto.getHashes() returns an array containing the names of all supported hash algorithms.

6. Random Data Generation

These methods generate cryptographically secure random data for security purposes.

• crypto.randomBytes(): crypto.randomBytes() generates cryptographically secure random data.
• crypto.randomFill(): crypto.randomFill() fills a buffer with cryptographically secure random values.
• crypto.randomFillSync(): crypto.randomFillSync() synchronously fills a buffer with random data.

7. Password-Based Key Derivation

These methods generate secure keys from passwords using key derivation algorithms.

• crypto.pbkdf2(): crypto.pbkdf2() provides an asynchronous implementation of the PBKDF2 key derivation function.
• crypto.pbkdf2Sync(): crypto.pbkdf2Sync() provides a synchronous implementation of PBKDF2.
• crypto.scrypt(): crypto.scrypt() provides an asynchronous implementation of the scrypt key derivation algorithm.

8. Diffie-Hellman Key Exchange

These methods implement the Diffie-Hellman algorithm used for secure key exchange.

• crypto.getDiffieHellman(): crypto.getDiffieHellman() creates a predefined Diffie-Hellman key exchange object.
• crypto.createDiffieHellmanGroup(): crypto.createDiffieHellmanGroup() creates a Diffie-Hellman group used for key exchange.
• crypto.createDiffieHellman(primeLength, generator): crypto.createDiffieHellman(primeLength, generator) creates a Diffie-Hellman key exchange object using a generated prime number.
• crypto.createDiffieHellman(prime, primeEncoding, generator, generatorEncoding): crypto.createDiffieHellman(prime, primeEncoding, generator, generatorEncoding) creates a Diffie-Hellman key exchange object using a specified prime.

9. Elliptic Curve Cryptography

These methods support elliptic curve cryptography for secure communication.

• crypto.createECDH(): crypto.createECDH() creates an Elliptic Curve Diffie-Hellman key exchange object.
• crypto.getCurves(): crypto.getCurves() returns an array containing the names of supported elliptic curves.

10. Digital Signatures

These methods are used to create and verify digital signatures.

• crypto.createSign(): crypto.createSign() creates a Sign object used to generate digital signatures.
• crypto.createVerify(): crypto.createVerify() creates a Verify object used to verify digital signatures.

11. Key Generation

These methods generate asymmetric public and private key pairs.

• crypto.generateKeyPair(): crypto.generateKeyPair() generates a new asymmetric key pair of the specified type.
• crypto.generateKeyPairSync(): crypto.generateKeyPairSync() synchronously generates a new asymmetric key pair.

12. Other Methods

These additional methods provide utility functions related to cryptography.

• crypto.getCiphers(): crypto.getCiphers() returns an array containing the names of all supported cipher algorithms.
• script.createCachedData(): script.createCachedData() creates cached data that can be used with the script constructor to improve performance.