03-17-2012 08:13 AM
All of the integration methods work with any programming language. Unfortunately you'll be hard pressed to find code samples for C++ as Authnet doesn't offer any and I would be surprised if anyone opensourced their C++ code.
03-23-2012 01:59 PM
The only way you can charge cards directly from an application is with AIM. Since you're connecting directly to Authorize.net and using their SSL, all your application has to be able to do is connect successfully to an https:// URL, you don't need a certificate on your end.
Keep in mind that AIM has PCI security requirements, and should only be used on devices that are used solely for charging cards, are not networked to other devices, connect directly to Authorize.net, and have sufficient firewalls / security software / etc. to protect your Internet connection. Following those rules will qualify you for SAQ-C, which is doable, rather than SAQ-D, which isn't.
Short of that, you can just put the charging part of the application on a web site and pop up a web browser. That will enable you to use methods hosted from Authorize.net, such as SIM or DPM.