Hi Paul,
I have implemented similar sort of IAS implementation as extension dll. Initially I also faced many problems while implementing the same since there is very less information available on internet. Although whatever the information is available they are scattered and not properly organized. With my experience I can share something with you which might be of help to you.
If you are looking for any free dll on internet then u might return empty handed. From you above post it seems you want to implement something where the client is you web citrix which will be connecting to the IAS server on Win2003 server or NPS server on Win2008 server. The IAS/NPS will inturn connect to MS SQL server for further authentication or authorization process.
As per my understanding IAS/NPS understands only the unmanaged windows dll. So I would suggest to use VC++ to create MFC Extension dll which will expose following functions as part of dll:
1) RadiusExtensionInit 2) RadiusExtensionProcessEx 3) RadiusExtensionFreeAttributes 4) RadiusExtensionTerm
You can get the signature of these functions from MSDN
Within the RadiusExtensionProcessEx function you will have to write the code which will connect with your MS SQL and do further processing. Once you are done with the dll, then you will have to create following registry entries:
Refer: http://msdn.microsoft.com/en-us/library/bb892024%28VS.85%29.aspx
The extension dlls can be registered and hence by the above mentioned registry entries only you can notify the IAS/NPS about that dll. Once the registry entries are done, restart the IAS/NPS server, now make a hit from the citrix web client to IAS/NPS. IAS/NPS will look for the above registry entry and if any dll is referred then it sarts calling the 2nd function with each call as mentioned above.
One more thing if your IAS/NPS sever is on 64-bit machine then you will have to build the 64-bit version of the dll.
Thanks,
Ashish
