CryptAcquireContext Fails in VFP on Windows 7

Question

More of a direct answer for myself, and others who may be supporting legacy VFP apps using the _Crypt.vcx class library from Visual Foxpro.

I recently upgraded to a new Windows 7-64bit machine for development and had to support as described a legacy system. The _Crypt.vcx class is used for encryption/decryption. While running the app on the new machine, I had a problem getting / setting decryption values.

The failure was when trying to get a provider handle when calling the "CryptAcquireContext" during the class initialization.

For whatever reason, and I do not know why, there is a property on the class called

This.cContainerName

and from the "WinCrypt.h" file, if no value is provided for this property, it was getting set to "FOXPRO_APP". Again, for whatever reason, I don't know, but through debugging, I forced changing this value to anything else, such as just "Visual FoxPro", and the encryption worked.

That is the ONLY change I made, and it is now working in VFP on Windows 7 machines.

So, now, on that class, I have changed the default value to "Visual FoxPro" (or you could change in the header file) and it works.

Hope this helps anyone in the future.

Answer 1

Again, self-answered, hoping it helps anyone else on legacy support.