Error Received when Punching Out to Oracle Exchange (Model 5)

Hello

We have just obtained registration approval from testexchange.oracle.com and i have started setting up the punch-out in iProcurement. However, when I click on the punch-out link, I receive the error below. How do I obtain the digital certificate for testexchange.oracle.com so that I can pass the SSL handshake?

Error Code: 201 Unable To Reach Supplier Site
Unable to send the Login Request XML.
Supplier Login URL: https://testexchange.oracle.com:443
Request String: <?xml version = '1.0' encoding = 'UTF-8'?>
<request>
   <header version="1.0">
      <login>
         <username>
            <![CDATA[PROXY_USER]]>
         </username>
         <password>*********************************************</password>
      </login>
      <action>
         <![CDATA[shopping]]>
      </action>
      <language>
         <![CDATA[US]]>