The crypto.createSign() will create and return a sign object tha uses the passed algorithm in the parameter. One can use, crypto.getHashes() to get the names of all the available digest algorithms. You can create a Sign instance by using the name of the signature algorithms such as 'RHA-SHA256' only in some of the cases, instead of a digest algorithm.
Syntax
crypto.createSign(algorithm, [options])
Parameters
The above parameters are described as below −
algorithm – It takes the input for the algorithm name to be used while creating the sign object/instance.
options – This is an optional parameter that can be used for controlling the stream behaviour.
Example
Create a file with name – createSign.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 createSign.js
createSign.js
// Node.js program to demonstrate the use of createSign() method // Importing the crypto module const crypto = require('crypto'); // Creating sign object with the input algorithm const sign = crypto.createSign('SHA256'); // Returning the sign object console.log(sign);
Output
C:\home\node>> node createSign.js Sign { _handle: {}, _writableState: WritableState { objectMode: false, highWaterMark: 16384, finalCalled: false, needDrain: false, ending: false, ended: false, finished: false, destroyed: false, decodeStrings: true, defaultEncoding: 'utf8', length: 0, writing: false, corked: 0, sync: true, bufferProcessing: false, onwrite: [Function: bound onwrite], writecb: null, writelen: 0, bufferedRequest: null, lastBufferedRequest: null, pendingcb: 0, prefinished: false, errorEmitted: false, emitClose: true, autoDestroy: false, bufferedRequestCount: 0, corkedRequestsFree: { next: null, entry: null, finish: [Function: bound onCorkedFinish] } }, writable: true, _events: [Object: null prototype] {}, _eventsCount: 0, _maxListeners: undefined }
Example
Let's take a look at one more example.
// Node.js program to demonstrate the use of createSign() method // Importing the crypto module const crypto = require('crypto'); // Creating sign object with the input algorithm const sign = crypto.createSign('SHA256'); // Returning the sign object console.log(sign.write('Welcome to Tutorials Point'));
Output
C:\home\node>> node createSign.js true