Node.js crypto.createVerify() Method

The crypto.createVerify() method is used to create a Verify object that uses the stated algorithm. Moreover, you can use crypto.getHashes() to access the names of all the available signing algorithms.

Syntax:

crypto.createVerify( algorithm, options )

Parameters: This method accept two parameters as mentioned above and described below:

• algorithm: It is a string type value. A Sign instance can be created by applying the name of a signature algorithms, like ‘RSA-SHA256’, in place of a digest algorithms.
• options: It is an optional parameter that is used to control stream behavior. It returns an object.

Return Value: It returns Verify object.

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

Example 1:

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

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

// Creating verify object with its algo
const verify = crypto.createVerify('SHA256');

// Returns the 'Verify' object
console.log(verify);

Output:

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,
  domain: null,
  _events: [Object: null prototype] {},
  _eventsCount: 0,
  _maxListeners: undefined }

Example 2:

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

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

// Creating verify object with its algo
const verify = crypto.createVerify('SHA256');

// Writing data to be signed and verified
verify.write('some text to sign');

// Calling end method
verify.end();

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

    // Encrypted data
    const l2 =
  "MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEXIvPbzLjaPLd8jgiv1TL/X8PXpJNgDkGRj9U9Lcx1yKURpQFVavcMkfWyO8r7JlZNMax0JKfLZUM1IePRjHlFw=="

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

    // Constructing public key
    const publicKey = l1 + l2 + l3

    // Signature to be verified
    const signature = "MEYCIQCPfWhpzxMqu3gZWflBm5V0aetgb2/S+SGyGcElaOjgdgIhALaD4lbxVwa8HUUBFOLz+CGvIioDkf9oihSnXHCqh8yV";

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

Output:

false

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