Omnipay is an open source payment processor library that supports multiple payment processors (around 30 currently). https://github.com/omnipay/omnipay
This extension exposes those processors to CiviCRM. However, the focus so far has been on Cybersource Secure Acceptance POST. This processor uses the Transparent Redirect method (also called Direct Post Method) which is new to CiviCRM and involves the normal billing address data being collected onsite but credit card details being entered into a form that POSTs directly to Cybersource.
If your gateway uses a callback (AKA IPN or Silent Post or web hook) configure it to post to https://yoursite/civicrm/civicrm/payment/ipn?processor_id=x - obviously you need to swap out 'yoursite' & 'x' and if you don't have https use http. For test instances add &test=1 to the URL
Note Sagepay recurring is supported as of version 5.34
Current gateways (this is a moving target but as of 5 Jan 15)
- Cybersource
- GoPay (release 1.4)
- Mollie - integrated into master & being tested
- Paypal - works but disabled due to built in status
- Bitpay - worked under testing on one site but not another -disabled
There are a large range of others available which would be good to test - but still some technical challenges
