Sign

Class: Sign

The Sign Class is a utility for generating signatures. It can be used in one of two ways:

• As a writable stream, where data to be signed is written and the sign.sign() method is used to generate and return the signature, or
• Using the sign.update() and sign.sign() methods to produce the signature.

The crypto.createSign() method is used to create Sign instances. Sign objects are not to be created directly using the new keyword.

Example: Using Sign objects as streams:

const crypto = require('crypto');
const sign = crypto.createSign('RSA-SHA256');

sign.write('some data to sign');
sign.end();

const private_key = getPrivateKeySomehow();
console.log(sign.sign(private_key, 'hex'));
  // Prints the calculated signature

Example: Using the sign.update() and sign.sign() methods:

const crypto = require('crypto');
const sign = crypto.createSign('RSA-SHA256');

sign.update('some data to sign');

const private_key = getPrivateKeySomehow();
console.log(sign.sign(private_key, 'hex'));
  // Prints the calculated signature