(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, 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 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();