HTTPAuth
The elements described here are not a part of the Win32 API. They are
specific to Security Providers and Account Management.
Please be aware In the future many of these elements will be replaced
with OLE Interfaces, and will subsequently be dropped.
Documentation on sspi.h can be found in \mstools\help\spk.mvb --
use \mstools\help\infoview.exe spk.mvb to view.