Crypto Facilities Request Authentication

This is a help readme for Crypto Facilities Ltd, to demonstrate the message signing in REST v3 API and WS v1 API requests and subscriptions.

NodeJs

const API_SECRET = "..."
var nonce = 1;

// Generate nonce
function createNonce() {
	
	var timestamp = (new Date()).getTime();
	var n = timestamp + ("0000" + nonce++).slice(-5);
	return n;
}

// Sign request
function signMessage(endpoint, nonce, postData) {
	const utf8 = require("utf8");
	const crypto = require('crypto');
	
	// step 1: concatenate postData, nonce + endpoint   
	var message = postData + nonce + endpoint;

	// Step 2: hash the result of step 1 with SHA256
	var hash = crypto.createHash('sha256').update(utf8.encode(message)).digest();

	// step 3: base64 decode apiPrivateKey
	var secretDecoded = Buffer.from(API_SECRET,'base64');

	// step 4: use result of step 3 to hash the resultof step 2 with
	var hash2 = crypto.createHmac('sha512',secretDecoded).update(hash).digest();
	
	// step 5: base64 encode the result of step 4 and return
	var signed = Buffer.from(hash2).toString('base64')

	return signed;
}