The crypto.createDiffieHellmanGroup(primeLength, [generator]) method is used for creating a key exchange object that generates a prime number of primeLength bits using a numeric generator. Default value is 2 when the generator is not defined.
Syntax
crypto.createDiffieHelmmanGroup(primeLength, [generator])
Parameters
The above parameters are described as below −
primeLength – The number of prime bits that will be generated. Input value is of type number.
generator – Generator for generating the exchange key object. Default value: 2.
Example
Create a file with name – index.js and copy the below code snippet. After creating file, use the following command to run this code as shown in the example below −
node index.js
index.js
// crypto.createDiffieHellman(primeLength, [generator]) Demo Example
// Importing the crypto module
const crypto = require('crypto');
// Initializing the variable primeLength
var primeLength = 29;
// Creating DiffieHellman keyexchange object
var exchangeKey = crypto.createDiffieHellman(primeLength);
// Printing the exchange keys
console.log("DiffieHellman key is: " + exchangeKey.generateKeys('base64'));Output
C:\home\node>> node index.js DiffieHellman key is: BaRoaA==
Example
Let's take a look at one more example.
// crypto.createDiffieHellman(primeLength, [generator]) Demo Example
// Importing the crypto module
const crypto = require('crypto');
// Initializing the variable primeLength
var primeLength = 29;
var generator = 3; //Default value is 2
// Creating DiffieHellman keyexchange object
var exchangeKey = crypto.createDiffieHellman(primeLength, generator);
// Printing the exchange keys
console.log("DiffieHellman keys are: " + exchangeKey.generateKeys('hex'));
// Displays public and private keys
console.log("Public Key is: ",
exchangeKey.getPublicKey('hex'));
console.log("Private Key: ",
exchangeKey.getPrivateKey('hex'));Output
C:\home\node>> node index.js DiffieHellman keys are: 1a21670d Public Key is: 1a21670d Private Key: 0d4a1a3c