(PHP Extension) Walmart Partner API Authentication (Generate a Signature for a Request)

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

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

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

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

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

// Build the string to sign.
$sbStringToSign = new CkStringBuilder();
$sbStringToSign->Append($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');

$privKey = new CkPrivateKey();
// 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) {
    print $privKey->lastErrorText() . "\n";
    exit;
}

$rsa = new CkRsa();
$success = $rsa->ImportPrivateKeyObj($privKey);
if ($success != true) {
    print $rsa->lastErrorText() . "\n";
    exit;
}

// We want a base64 signature string.
$rsa->put_EncodingMode('base64');

$signatureString = $rsa->signStringENC($sbStringToSign->getAsString(),'SHA256');
if ($rsa->get_LastMethodSuccess() != true) {
    print $rsa->lastErrorText() . "\n";
    exit;
}

print 'Signature String: ' . $signatureString . "\n";

?>