Node crypto.randomBytes() Method
The crypto.randomBytes() method is used to generate cryptographically well-built artificial random data and the number of bytes to be generated in the written code.
Syntax:
crypto.randomBytes( size, callback )
Parameters: This method accepts two parameters as mentioned above and described below:
- size: It is of type number which indicates the number of bytes to be generated.
- callback: It is a function which is made of two parameters namely, err and buf. However, if a callback function is available in the stated code then the bytes are generated asynchronously else these bytes are generated synchronously.
Return Type: It returns a Buffer if the callback function is given.
Example 1: Below example illustrate the use of crypto.randomBytes() method in Node.js:
Javascript
// Node.js program to demonstrate the // crypto.randomBytes() method// Including crypto moduleconst crypto = require('crypto');// Calling randomBytes method with callbackcrypto.randomBytes(127, (err, buf) => { if (err) { // Prints error console.log(err); return; } // Prints random bytes of generated data console.log("The random data is: " + buf.toString('hex'));}); |
Output: Here, callback function is provided so random bytes are generated asynchronously.
The random data is:
074e48c8e3c0bc19f9e22dd7570037392e5d0bf80cf9dd51bb7808872a511b3 c1cd91053fca873a4cb7b2549ec1010a9a1a4c2a6aceead9d115eb9d60a1630e056f3accb10574cd563 371296d4e4e898941231d06d8dd5de35690c4ba94ca12729aa316365145f8a00c410a859c40a46bbb4d 5d51995241eec8f6b7a90415e
Example 2: Below examples illustrate the use of crypto.randomBytes() Method in Node.js:
Javascript
// Node.js program to demonstrate the // crypto.randomBytes() method// Including crypto moduleconst crypto = require('crypto');// Calling randomBytes method without callbackconst buf = crypto.randomBytes(60);// Prints random bytes of generated dataconsole.log("The random bytes of data generated is: " + buf.toString('hex')); |
Output: Here, callback function is not provided so bytes are generated synchronously
The random bytes of data generated is: 865f38a9950699794e81fcd91584f8612f5a42aec5b7bbed48c1683832c519c22c836c91fe1afc0330a2ea02dea0a31a1f509dfde1a780ce82ec0eb1
We have a Cheat Sheet on Node crypto methods where we covered all the crypto methods to check those please go through Crypto Module Complete Reference this article.