The ccLinkPoint class interfaces with the LinkPoint API via a managed DLL that interfaces with a couple of unmanaged DLLs (the SSL interfaces). The process of using LinkPoint involves:

• Signing up with LinkPoint and getting a test account
  
• Downloading and installing the .NET API
  
• Using the ccLinkPoint class from within .NET
  
• Enabling the class by setting a #define EnableLinkPoint
  

Getting and Installing the LinkPoint API

The LinkPoint API provides a variety of components for different languages and development environments. The API basically handles setting up transactions and sending the transactions via HTTPS to the LinkPoint Gateway server. To work with the API you only the appropriate component plus a little code to drive the component which is provided by the wwLinkPoint class.

You can download the LinkPoint API from:
https://www.linkpoint.com/viewcart/

You'll want to use the LinkPoint API .NET (C# or VB) download for Windows. This download includes a couple of DLLs (linkpointTransaction.dll and lpssl.dll) which you should copy in your bin or executable directory so your application can find it.

OpenSSL is a separate, required download
For .NET you will also need to download the OpenSSL DLLs which Linkpoint uses. You can go to http://www.linkpoint.com/support/ and follow the links from there to download and drop libeay.dll and ssleay.dll into your System32 directory.

Using the wwLinkPoint Class

Once the LinkPoint API is installed you'll need the following information from your confirmation email(s):

• The path to the filename to which you copied your Certificate (a .PEM file)
  
• Your Store Number
  
• Your Store Password
  
• The domain name and port number of the live or test server
  

Enabling the ccLinkPoint class

Because the LinkPoint API has a dependency on the external LinkPoint assemblies the ccLinkPoint class by default disables the class. At the top of the ccLinkPoint class there's a #define EnableLinkPoint directive, which is commented out by default. When commented the body of the class is included and any attempt to instantiate the class fails with an exception.

To enable the class uncomment the #define EnableLinkPoint directive. Then copy the LinkpointTransaction.dll and lpssl.dll into the bin/executable directory of your application and add a reference in your project to LinkPointTransaction.dll.

Although a factory pattern might have isolated this interface more cleanly it would have also required a separate assembly. Since LinkPoint is a specialty install and you will need to copy the LinkPoint DLLs explicitly anyway we opted for this simpler more integrated approach.

Special Properties you need to set

CC = new ccLinkPoint();
CC.MerchantPassword = App.Configuration.CCMerchantId;   // "123412314"
CC.CertificatePath = App.Configuration.CCCertificatePath;     // "d:\app\MyCert.pem" 

// *** HTTP Link can be server name plus port
CC.HTTPLink = "staging.linkpt.net:1229";
// CC.Port = 1229;    // or specify port separately