Openbravo POS First Data Link Point Payment Gateway Integration -- 2

We are using Openbravo POS. We plan to move from [login to view URL] to First Data to handle our retail grocery store (card present) credit card transactions. [login to view URL] is handing off the transactions to First Data anyways, but [login to view URL] was very easy for me to implement. However, some of our credit cards transactions are being declined even though they work fine on our physical terminals. This has been going on for far too long. Help me help our customers. You should be able to accomplish this by just editing [login to view URL] Source code and API documentation is readily available online. The certificates come in .pem extension and should be .p12 Files attached. My errors include: "Invalid XML" "Transaction Error Null" You must provide explanations for your changes and installation i.e. certificate installation. This must be fully functional on a First Data test account for proof of functionality. ******************** BONUS + $ for extra work ******************** Save me the trouble of coding after your integration. It should follow my [login to view URL] flow, or better. The only forms of transactions I require are 1. SALE (easy. total > 0) 2. VOID (should be issued on "returns" for transactions that haven't been batched & if total < 0. (for the same trans_id already processed) procedure should first try to RETURN up to the total amount. If return fails, then the transaction is on the same day and we should issue an VOID followed by an immediate SALE of the difference = new_total - old_total). If the difference is 0, then obviously it's a full refund and no SALE should follow. 3. RETURN 4. CREDIT (does not require a trans_id, should be issued just if total < 0 and no gateway trans_id exists) You will need a lookup table to keep track of all transaction ID's so everything goes smoothly. Write to the file and chain the new total tied to the same transaction id. Overwrite duplicate keys. Here is an example with : and _ delimiters. :8019459012:8019459013=_21.00 :8019459012=_30.00 overwrite :8019459012=_50.00 overwrite :8019459012:8019459013=_50.00_5.00 purchase after void :8019459012:8019459013:8019459014=50.00_5.00_3.00 purchase after void More details once you sign up... *******************************************