HMAC Base64 Authentication? - php

Question

I have no clue what's even going on in this but I am attempting to use an API and they have yet another different authentication standard called HMAC with Sha384 to base64.
This is the example provided:
class ICObenchAPI {
private $privateKey = 'private-key';
private $publicKey = 'public-key';
private $apiUrl = 'https://icobench.com/api/v1/';
public $result;
public function getICOs($type = 'all', $data = ''){
return $this->send('icos/' . $type, $data);
}
public function getICO($icoId, $data = ''){
return $this->send('ico/' . $icoId, $data);
}
public function getOther($type){
return $this->send('other/' . $type, '');
}
private function send($action, $data){
$dataJson = json_encode($data);
$sig = base64_encode(hash_hmac('sha384', $dataJson, $this->privateKey, true));
$ch = curl_init($this->apiUrl . $action);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, $dataJson);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Content-Type: application/json',
'Content-Length: ' . strlen($dataJson),
'X-ICObench-Key: ' . $this->publicKey,
'X-ICObench-Sig: ' . $sig)
);
$reply = curl_exec($ch);
$ff = $reply;
$reply = json_decode($reply,true);
if(isset($reply['error'])){
$this->result = $reply['error'];
return false;
}else if(isset($reply['message'])){
$this->result = $reply['message'];
return true;
}else if(isset($reply)){
$this->result = json_encode($reply);
return true;
}else{
$this->result = htmlspecialchars($ff);
return false;
}
}
public function result(){
return $this->result;
}
}
I'm looking to take the PHP example provided and turn it into a nodeJS script, just really don't know where to start. I've looked at crypto-js and others but just don't comperhend what specifically is happening in the request to make since of what i'm even writing

Answer 1

Crypto-js is the good way to do.
You need to first encrypt your data and then Base64 it to create a signature used in header
let dataJSON = JSON.stringify(data);
let sign = CryptoJS.HmacSHA384(dataJSON, this.privateKey);
sign = CryptoJS.enc.Base64.stringify(sign);
I pushed on github a working example : ICObenchAPI.js

Answer 2

I wrote a Node js wrapper library called node-icobench. You are welcome to use it.
npm install node-icobench
Here is a sneak peek to the HMAC part with a few alterations for the sake of this example:
const crypto = require('crypto');
// Stringify POST data
let jsonData = JSON.stringify(data);
// Create HMAC based on algo and private key
let hmac = crypto.createHmac('sha384', privateKey);
// Create HMAC Digest of json data
hmac.update(jsonData);
// return Base64 encoding of HMAC
let signedData = hmac.digest('base64');