Cipher Class

This Cipher class provides various cryptographic functionalities using Node.js's built-in crypto module. It supports hashing, JWT creation and validation, RSA key pair generation, and AES-256 encryption and decryption.

Installation

To use this class, ensure you have Node.js installed.

Usage

Importing the Class

const { Cipher } = require('./path/to/cipher');

Initialization

Create an instance of the Cipher class by providing the necessary keys and tokens.

const cipher = new Cipher(aes256Key, aes256Iv, appKey, appToken);

Methods

hash(input, [algorithm='sha256'])

Generates a hash of the input using the specified algorithm.

const hash = cipher.hash('your-input-string', 'sha256');

CheckClientHeaders(clientAppKey, clientAppToken)

Checks the validity of client headers.

cipher.CheckClientHeaders(clientAppKey, clientAppToken)
    .then(isValid => console.log(isValid))
    .catch(error => console.error(error));

createJWT(payload, jwtPrivateKey, [validationInputPromise])

Creates a JWT with the given payload and private key. Optionally, a validation promise can be provided.

cipher.createJWT(payload, jwtPrivateKey, validationInputPromise)
    .then(token => console.log(token))
    .catch(error => console.error(error));

getSessionData(JWTtoken)

Gets session data from a JWT.

cipher.getSessionData(JWTtoken)
    .then(sessionData => console.log(sessionData))
    .catch(error => console.error(error));

validateJWT(ip, jwt, jwtpublickey)

Validates a JWT with the given IP and public key.

cipher.validateJWT(ip, jwt, jwtpublickey, validationInputPromise)
    .then(isValid => console.log(isValid))
    .catch(error => console.error(error));

RSAGenerateKeyPair([encodingPrivateKeyType], [encodingFormatBoth], [encodingPublicKeyType], [bitLength])

Generates an RSA key pair.

cipher.RSAGenerateKeyPair()
    .then(([publicKey, privateKey]) => console.log(publicKey, privateKey))
    .catch(error => console.error(error));

RSAsignDocument(privateKey, dataToSign, [encodingFormat], [encodingType])

Signs data using RSA.

cipher.RSAsignDocument(privateKey, dataToSign)
    .then(signature => console.log(signature))
    .catch(error => console.error(error));

RSAverifySignature(publicKey, dataToVerify, signature, [encodingFormat], [publicKeyType])

Verifies an RSA signature.

cipher.RSAverifySignature(publicKey, dataToVerify, signature)
    .then(isValid => console.log(isValid))
    .catch(error => console.error(error));

AES256encrypt(text, salt)

Encrypts text using AES-256-CBC.

cipher.AES256encrypt('your-text', 'your-salt')
    .then(encryptedText => console.log(encryptedText))
    .catch(error => console.error(error));

AES256decrypt(cryptedText, salt)

Decrypts text using AES-256-CBC.

cipher.AES256decrypt(encryptedText, 'your-salt')
    .then(decryptedText => console.log(decryptedText))
    .catch(error => console.error(error));

Detailed Explanation of Salt Usage in AES256encrypt

The AES256encrypt method uses a salt to derive the key and IV for AES-256 encryption, ensuring unique and secure encryption for each salt value.

Key and IV Derivation

The key and IV are derived using the pbkdf2Sync function from the crypto module with the following parameters:

• this.#aes256Key: AES-256 key.
• this.#aes256Iv: AES-256 IV.
• salt: Salt value.
• 100000: Iterations for PBKDF2.
• 32: Key length in bytes.
• 16: IV length in bytes.
• 'sha512': Hash function.

Encryption Process

The AES256encrypt method uses the derived key and IV to perform AES-256-CBC encryption:

• text: Text to encrypt.
• salt: Salt value.
• createCipheriv('aes-256-cbc', key, iv): Creates a cipher object.
• cipher.update(text, 'utf-8', 'hex') + cipher.final('hex'): Encrypts the text.

Example Usage

const aes256Key = 'your-aes256-key';
const aes256Iv = 'your-aes256-iv';
const cipher = new Cipher(aes256Key, aes256Iv);

const textToEncrypt = 'Hello, World!';
const salt = 'random_salt';

cipher.AES256encrypt(textToEncrypt, salt)
    .then(encryptedText => console.log(encryptedText))
    .catch(error => console.error(error));

Using a unique salt for each encryption ensures different derived keys and IVs, enhancing security.

License

This project is licensed under the MIT License.