(Node.js) Walmart Partner API Authentication (Generate a Signature for a Request)

Demonstrates how to generate a signature for a Walmart Partner REST API call.

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

var os = require('os');
if (os.platform() == 'win32') {  
  var chilkat = require('@chilkat/ck-node23-win64'); 
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node23-linux-arm');
    } else if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node23-linux-arm64');
    } else {
        var chilkat = require('@chilkat/ck-node23-linux-x64');
    }
} else if (os.platform() == 'darwin') {
  var chilkat = require('@chilkat/ck-node23-mac-universal');
}

function chilkatExample() {

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

    var success;

    var consumerId = "b68d2a72....";
    var baseUrl = "https://marketplace.walmartapis.com/v2/feeds";
    // This is your Base64 encoded private key
    var privateEncodedStr = "MIICeAIBADANBgkqhkiG9w0BAQEFAA......";
    var httpMethod = "GET";

    // We need a timestamp in decimal string form representing the number of milliseconds since Jan 01 1970 UTC.
    var dt = new chilkat.CkDateTime();
    // Set bLocal = true for a timestamp in the local timezone.  Set bLocal = false for a UTC timestamp.
    var bLocal = false;
    // This gets the timestamp in seconds, not milliseconds.
    var timeStampVal = dt.GetAsUnixTime(bLocal);

    // Build the string to sign.
    var sbStringToSign = new chilkat.StringBuilder();
    sbStringToSign.Append(consumerId);
    sbStringToSign.Append("\n");
    sbStringToSign.Append(baseUrl);
    sbStringToSign.Append("\n");
    sbStringToSign.Append(httpMethod);
    sbStringToSign.Append("\n");
    sbStringToSign.AppendInt(timeStampVal);
    // We add three zero's so that the timestamp value is in milliseconds.
    // We don't care about accuracy down to less than a second.
    // All the server cares about is that the request was signed at the current date/time
    // within some reasonable margin of error (to account for systems having clocks
    // that may be slightly different).
    sbStringToSign.Append("000\n");

    var privKey = new chilkat.PrivateKey();
    // Load the private key into a private key object.
    // Note: Technically the private key is not PEM because it lacks the header/footer strings
    // used for PEM.  However, the LoadPem method will still accept it and load it correctly.
    success = privKey.LoadPem(privateEncodedStr);
    if (success !== true) {
        console.log(privKey.LastErrorText);
        return;
    }

    var rsa = new chilkat.Rsa();
    success = rsa.ImportPrivateKeyObj(privKey);
    if (success !== true) {
        console.log(rsa.LastErrorText);
        return;
    }

    // We want a base64 signature string.
    rsa.EncodingMode = "base64";

    var signatureString = rsa.SignStringENC(sbStringToSign.GetAsString(),"SHA256");
    if (rsa.LastMethodSuccess !== true) {
        console.log(rsa.LastErrorText);
        return;
    }

    console.log("Signature String: " + signatureString);

}

chilkatExample();