crypto.createVerify() Method in Node.js

The crypto.createVerify() will create and return a verify object that uses the passed algorithm in the parameter. One can use, crypto.getHashes() to get the names of all the available signing algorithms. You can create a Verify 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.createVerify(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 verify object/instance.

• options – This is an optional parameter that can be used for controlling the stream behaviour.

Example

Create a file with name – createVerify.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 createVerify.js

createVerify.js

// Node.js program to demonstrate the use of createVerify() method

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

// Creating verify object with the input algorithm
const verify = crypto.createVerify('SHA256');

// Returning the verify object
console.log(verify);

Output

C:\home\node>> node createVerify.js
Verify {
   _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 createVerify() method

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

// Creating the verify object from SHA256 algo
const verify = crypto.createVerify('SHA256');

// Writing the below data to be signed and verified
verify.write('TutorialPoint');

// Ending the method
verify.end();

   // Beginning public key execution
   const l1 = "-----BEGIN PUBLIC KEY-----\n"

   // Encrypted data
   const l2 = "MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEXIvPbzLjaPLd8jgiv1TL/X8PXpJNgDkGRj9U9Lcx1
      yKURpQFVavcMkfWyO8r7JlZNMax0JKfLZUM1IePRjHlFw=="

   // Finishing public key execution
   const l3 = "\n-----END PUBLIC KEY-----"

   // concatenating all public keys
   const publicKey = l1 + l2 + l3

   // Signature that will be verified
   const signature = "MEYCIQCPfWhpzxMqu3gZWflBm5V0aetgb2/S+SGyGcElaOjgdgIhALaD4lbxVwa8HUUBFOLz+CGvI
ioDkf9oihSnXHCqh8yV";

   // Prints true if signature is verified else false
   console.log(verify.verify(publicKey, signature));

Output

C:\home\node>> node createVerify.js
false