SOAP and https

Hi I am new in php (php4) and Linux and perhaps my problem is not so big :) I'm making internet store. When the buyer will pay, then my aplication redirect him to the bank server and then he pays on banks server. To know, if the buyer has paid, bank server every 30 minuts calls my server on https://mystore.com/pay/paid.php . When the banks calls my server, she also send data about payments in SOAP. But I don't have idea, hot to see those data. Bank has also gave me his root certificate (certificate1.cer) and user (certificate2.cer), but I don't know, how to include this in my Linux (Apache) server. I think that if I will make corenct instalations of Certificates, then i will see the SOAP data (I hope :) ) Can anybody help me? Thanks Janez