Node.js – diffieHellman.getPublicKey() Method

The diffieHellman.getPublicKey() returns the Diffie-Hellman generated public key that is specified by the encoding passed. It will return a string in case the encoding is passed, else it will return a buffer.

Syntax

diffieHellman.getPublicKey([encoding])

Parameters

• encoding – This parameter specifies the encoding of the return value.

Example 1

Create a file with the name "publicKey.js" and copy the following code snippet. After creating the file, use the command "node publicKey.js" to run this code.

// diffieHellman.getPublicKey() Demo Example

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

// Initializing the diffieHellman
const dh = crypto.createDiffieHellman(512);

// Taking default publicKey as null
let publicKey = null

// Generate Keys
dh.generateKeys()

// Getting string with base64 encoding
publicKey = dh.getPublicKey('base64')
console.log('Public Key (with base64 encoding): ', publicKey, '
')

// Getting buffer without encoding
publicKey = dh.getPublicKey()
console.log('Public Key ( ithout encoding): ', publicKey, '
')

Output

Public Key (with base64 encoding): ZY0wKH6d7Te8OPeIgHr7OlwSiH8d7MLGya9wopMgt5/liiKwFTgXsGE/07BQ6u98kUJJbr8cRgtD02D2I21xsg==

Public Key ( ithout encoding): 

Example 2

Let’s take a look at one more example.

// diffieHellman.getPublicKey() Demo Example

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

// Initializing the diffieHellman
const a = crypto.createDiffieHellman(512);
const b = crypto.createDiffieHellman(
   a.getPrime(), a.getGenerator() );

// Generating Keys
a.generateKeys()
b.generateKeys()

// Generating public key for a
let keyA = a.getPublicKey('base64')

// Generating public key for b
let keyB = b.getPublicKey('base64')

// Computing secret
let secretA = a.computeSecret(keyB, 'base64', 'base64')
let secretB = b.computeSecret(keyA, 'base64', 'base64')

if(secretA === secretB)
   console.log('Symmetric key A:', secretA)
   console.log('Symmetric key B:', secretB)

Output

Symmetric key A: shrRZLrIF/Uz52T4XCjALAuRgJ+1luVSesG2Q4bhW2+59qcWu5SI8P3XjSUXRMIcvIGQc2gzv/ENirozxU+iwA==
Symmetric key B: shrRZLrIF/Uz52T4XCjALAuRgJ+1luVSesG2Q4bhW2+59qcWu5SI8P3XjSUXRMIcvIGQc2gzv/ENirozxU+iwA==