title: Walmart Seller API POST not working, Gives 401 unauthorized in PHP only
body: <p>I am trying to GET Walmart Seller API using CURL PHP to acknowledge.
  Can any one suggest which RSA PHP library i need to use ? So that Authentication Signature is verify while making calls to walmart.</p>
  
  <p>Any one experience with this ?</p>
  
  <pre><code>$headers = array(
      'WM_SVC.NAME: Walmart Marketplace',
      'WM_QOS.CORRELATION_ID: 14730688612',
      'WM_SEC.TIMESTAMP:14730688612',
      'WM_SEC.AUTH_SIGNATURE: XXXXXXXXXXX'
      'WM_CONSUMER.ID: XXXXXXXXXXX',
      'Content-Type: application/xml',
      'Accept: application/xml',
   );
  
  
  $ch = curl_init();
  curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
  curl_setopt($ch, CURLOPT_URL,$requestUrl);
  curl_setopt($ch, CURLOPT_HEADER, TRUE);
  curl_setopt($ch, CURLOPT_VERBOSE, true);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
  curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'GET');
  curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
  curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
  $result = curl_exec( $ch );
  if(curl_errno($ch)):
      echo 'Curl error: '.curl_error($ch);
  endif;
  </code></pre>
  
  <p>I have used reference that found while googling.</p>
  
  <pre><code> - https://github.com/fillup/walmart-auth-signature-php
  </code></pre>