title: Paypal Access - SSL certificate: unable to get local issuer certificate
body: <p>I'm working with cUrl and PHP to make a request to a server (for paypal access)</p>
  
  <p>Paypal developer website does never mention that an SSL certificate is required to use PayPal access API, however the code that I use to request the token is the following:</p>
  
  <pre><code>$options = array(
                  CURLOPT_URL =&gt; $url,
                  CURLOPT_POST =&gt; 1,
                  CURLOPT_VERBOSE =&gt; 1,
                  CURLOPT_POSTFIELDS =&gt; $postvals,
                  CURLOPT_RETURNTRANSFER =&gt; 1,
                  CURLOPT_SSLVERSION =&gt; 3
  );
  
  curl_setopt_array($ch, $options);
  
  $response = curl_exec($ch); 
  echo curl_error($ch);
  </code></pre>
  
  <p>This echo outputs the following error:</p>
  
  <pre><code>SSL certificate problem: unable to get local issuer certificate
  </code></pre>
  
  <p>My questions are: </p>
  
  <p>1) do I need SSL to use paypal access if I need only to get the user email?</p>
  
  <p>2) if I do not need SSL why this error occours?</p>
  
  <p>PS: the endpoint is the following: <a href="https://www.sandbox.paypal.com/webapps/auth/protocol/openidconnect/v1/tokenservice" rel="noreferrer">https://www.sandbox.paypal.com/webapps/auth/protocol/openidconnect/v1/tokenservice</a></p>