(Node.js) Payeezy HMAC Computation

Demonstrates how to calculate the HMAC for a Payeezy REST request.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    var crypt = new chilkat.Crypt2();
    var prng = new chilkat.Prng();
    var success;

    // An API key such as y6pWAJNyJyjGv66IsVuWnklkKUPFbb0a
    var apiKey = "my_api_key";
    // An API secret such as 86fbae7030253af3cd15faef2a1f4b67353e41fb6799f576b5093ae52901e6f7
    var apiSecret = "my_api_secret";
    // A token such as fdoa-a480ce8951daa73262734cf102641994c1e55e7cdf4c02b6
    var token = "my_merchant_token";

    // The nonce is a random number (bytes), something like "6057786719490086000"
    var nonce = prng.GenRandom(8,"decimal");
    console.log("nonce = " + nonce);

    var dtNow = new chilkat.CkDateTime();
    dtNow.SetFromCurrentSystemTime();
    var sbTimestamp = new chilkat.StringBuilder();
    // Get the epoch timestamp in seconds
    sbTimestamp.Append(dtNow.GetAsUnixTimeStr(false));
    // Change it to milliseconds
    sbTimestamp.Append("000");
    // The timestamp is a number similar to this: 1546011905000 (which is a timestamp taken on 28-Dec-2018).
    var timestamp = sbTimestamp.GetAsString();
    console.log("timestamp = " + timestamp);

    // Generate the following JSON request body:
    // 	{
    // 	  "merchant_ref": "Astonishing-Sale",
    // 	  "transaction_type": "authorize",
    // 	  "method": "token",
    // 	  "amount": "200",
    // 	  "currency_code": "USD",
    // 	  "token": {
    // 	    "token_type": "FDToken",
    // 	    "token_data": {
    // 	      "type": "visa",
    // 	      "value": "2537446225198291",
    // 	      "cardholder_name": "JohnSmith",
    // 	      "exp_date": "1030",
    // 	      "special_payment": "B"
    // 	    }
    // 	  }
    // 	}

    var json = new chilkat.JsonObject();
    json.UpdateString("merchant_ref","Astonishing-Sale");
    json.UpdateString("transaction_type","authorize");
    json.UpdateString("method","token");
    json.UpdateString("amount","200");
    json.UpdateString("currency_code","USD");
    json.UpdateString("token.token_type","FDToken");
    json.UpdateString("token.token_data.type","visa");
    json.UpdateString("token.token_data.value","2537446225198291");
    json.UpdateString("token.token_data.cardholder_name","JohnSmith");
    json.UpdateString("token.token_data.exp_date","1030");
    json.UpdateString("token.token_data.special_payment","B");

    // string hashData = apiKey + nonce + timestamp + token + jsonString;
    var sbHmacData = new chilkat.StringBuilder();
    sbHmacData.Append(apiKey);
    sbHmacData.Append(nonce);
    sbHmacData.Append(timestamp);
    sbHmacData.Append(token);
    sbHmacData.Append(json.Emit());

    // HMAC the data to produce a hex string.
    crypt.EncodingMode = "hexlower";
    crypt.MacAlgorithm = "hmac";
    crypt.SetMacKeyString(apiSecret);
    crypt.HashAlgorithm = "sha256";
    crypt.Charset = "utf-8";
    var hexHash = crypt.MacStringENC(sbHmacData.GetAsString());

    // Now base64 encode the hex string:
    var sbBase64Hash = new chilkat.StringBuilder();
    sbBase64Hash.Append(hexHash);
    sbBase64Hash.Encode("base64","utf-8");

    console.log("This is the Authorization header to be sent with the payeezy request:");
    console.log("Authorization: " + sbBase64Hash.GetAsString());

}

chilkatExample();