I've got most of the basic WSSPI managed wrapper already built, and I'm adding a few NUnit tests.
The lousy part is that lost a good hour trying to find out why the managed wrapper didn't work, while the unmanaged code did, only to find out that it was my own fault! It turned out I was passing the incorrect buffer type to the SSPI Context APIs, so instead of passing
SECBUFFER_TOKEN as I should have, I was passing
SECBUFFER_DATA. No wonder I was getting an invalid token error...