[freetds] Windows authentication on Windows

jklowden at schemamania.org jklowden at schemamania.org
Tue Jan 26 13:42:28 EST 2010

On Tue, Jan 26, 2010 at 02:53:51PM +0100, Frediano Ziglio wrote:
> 2010/1/26 James K. Lowden <jklowden at freetds.org>:
> > Mark Brand wrote:
> >> I would like to avoid specifying the password when making the
> >> connection. I am using FreeTDS cross-compiled in mingw-cross-env.
> >> http://www.nongnu.org/mingw-cross-env/
> >
> > The only such API call in NTWDBLIB.DLL is one of the SSPI functions:
> > InitSecurityInterface(). It returns a dispatch table to the rest of the
> > SSPI functions, so that would seem to be what they're doing. From the
> > docs, it looks like InitializeSecurityContext(),
> > AcquireCredentialsHandle(), and EncryptMessage() are what we need.
> I committed an initial patch for SSPI support... quite limited:
> - currently supported using MingW cross compiler
> - use only NTLM, no SPNEGO or Kerberos
> - does not take into account username/password (so using any
> domain\user and a password will use your current account)
> - have some possible leak (dll initilization is not thread safe)
> Attached patch for review.
> I uploaded a dll cross compiled at http://freetds.sf.net/odbc.zip. I
> also applyed a fake ole registration extension to dll so you can
> "register" odbc driver using regsvr32 executable. Just copy the dll
> somewhere and execute

Excellent!  Absolutely amazingly jaw-dropping awesome!  

I modified Nmakefile to build tds.lib with sspi.c (and to generate 
header files).  It works!  

$ echo select @@version | src\apps\win32\debug\bsqldb.exe -S %S% -U "" -P ""

Microsoft SQL Server 2005 - 9.00.3282.00 (X64)
        Aug  5 2008 00:48:00
        Copyright (c) 1988-2005 Microsoft Corporation
        Enterprise Edition (64-bit) on Windows NT 5.2 (Build 3790: Service Pack 2)

$ cl -? 2>&1 | grep Version
Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 14.00.50727.762 for 80x86

Did I mention how excellent this is?  The FreeTDS community owes you a 
big smooch.  



P.S.  One tiny question: you used function names like "AcquireCredentialsHandleA"; the canonical form is "AcquireCredentialsHandle". 
Does mingw need the "A" form, or can we use normal one?  

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