3

I want to HMAC SHA256 hash the normalized request using the client secret and base64 encode the result. I am getting different result in python and typeScript. My goal is to achieve python result in typeScript. How to do that?

I was able to convert hashlib.sha256 (Here is my approach) to typeScript equivalent but not sure about hmac.new

Python Code:

import hashlib
import hmac
import base64

request = "Hello World";
secret = "MySecret"

requestBytes = bytes(request.encode('utf-8'))
secretBytes = bytes(secret.encode('utf-8'))
hmacConversion = hmac.new(secretBytes, requestBytes, digestmod=hashlib.sha256).digest()
signature = base64.b64encode(hmacConversion)
print(signature)

Output:

b'm4nZSWE3Y/tPXToy/0cJMGpR2qpsXgCnF3tsSiZtYt0='

Sample Code

TypeScript Code:

var secret = "Hello World";
var body = "MySecret";

var hmac = crypto.createHmac("sha256", secret)
                 .update(Buffer.from(body, 'utf-8'))
                 .digest('hex');
console.log(hmac);


var hmac2 = crypto.createHmac("sha256", secret)
                 .update(body, 'utf-8')
                 .digest('hex');
console.log(hmac2);

Output:

f1f157335b0982cbba94290163d61582a87352817788b793238817dd631c26d4

Sample Code

GThree
  • 2,708
  • 7
  • 34
  • 67

1 Answers1

1

I found the answer. This is very silly mistake where I spent 1 day. Hope this would save someone's day.

Code:

var crypto = require('crypto');

// Below was silly mistake. In my question those parameters are swapped.
var body = "Hello World"; 
var secret = "MySecret";

var hmac = crypto.createHmac("sha256", secret )
                 .update(body)
                 .digest('base64')
console.log(hmac);

Output:

m4nZSWE3Y/tPXToy/0cJMGpR2qpsXgCnF3tsSiZtYt0=

Sample Code

GThree
  • 2,708
  • 7
  • 34
  • 67