Node.js crypto.createECDH() Method

The crypto.createECDH() method is an inbuilt application programming interface of crypto module which is used to create an Elliptic Curve Diffie-Hellman i.e, (ECDH) key exchange object with the help of a predefined curve which is defined by the curveName string. Moreover you can use crypto.getCurves() method in order to return the list of available curve names.

Syntax:

crypto.createECDH( curveName )

Parameters: This method accepts single parameters curveName which is of type string.

Return Value: It returns ECDH key exchange object.

Below examples illustrate the use of crypto.createECDH() method in Node.js:

Example 1:

// Node.js program to demonstrate the
// crypto.createECDH() method

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

// Creating ECDH with curve name
const curv = crypto.createECDH('secp521r1');

// Prints keys
console.log(curv.generateKeys());

Output:

<Buffer 04 01 0a cd d0 94 80 31 e8 ... >

Example 2:

// Node.js program to demonstrate the
// crypto.createECDH() method

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

// Creating ECDH with curve name
const curv = crypto.createECDH('secp521r1');
curv.generateKeys();

// Prints Public key
console.log("Public Key: ", curv.getPublicKey());

// Prints Private Key
console.log("Private Key :", curv.getPrivateKey());

Output:

Public Key: <Buffer 04 01 68 25 14 c8 ... >
Private Key : <Buffer 01 7a ab 4d 71 60 ... >

Reference: https://nodejs.org/api/crypto.html#crypto_crypto_createecdh_curvename