Connecting to Microsoft Dynamics CRM 4.0 from a legacy ASP application

Question

I have a legacy ASP application written in JScript. At the moment it uses its own database tables for user accounts and authentication. The customer data for this app is being moved into Microsoft Dynamics CRM 4.0, and I need to modify the ASP site's authentication to look up user credentials in Dynamics CRM instead.

Here's the possible approaches I've come up with so far:

1. Move all the authentication tokens into explicit cookies instead of relying on Session variables; then rewrite the login pages, etc. as .aspx pages, and connected to the Dynamics web service from within these pages using the WSDL-generated wrapper class.
2. Create a COM wrapper around the WSDL-generated wrapper class, and invoke this using Server.CreateObject() from within the legacy ASP pages
3. Write a JSON wrapper around the WSDL interface, and call this from within legacy ASP using the MSXML2.ServerXMLHTTP COM object or something similar
4. Call WSDL from ASP directly and parse the results using MSXML or something.

I'm thinking option 1 is probably the best at this stage, but I'm hoping someone out there has tried this before and can share the benefit of their experience!

Answer 1

We work in a mixed environment (some classic asp, some asp.net) and we hook into mscrm 3.0. So it's not exactly what you're doing but similar.

We do a combo of 1 & 2. We wrote a class library that encapsulates the mscrm web service functionality we need to use. We then expose that library to COM so both our legacy stuff and our asp .net apps can use it.

Then in the near future when we move to mscrm 4.0 the only thing we need to update is our class library as the asp and asp.net stuff should be unchanged.