[freetds] windows named pipe authentication

Frediano Ziglio freddy77 at gmail.com
Sat May 24 05:08:51 EDT 2008


Il giorno ven, 23/05/2008 alle 23.05 -0500, Thomas Stover ha scritto:
> OK here's one from left field. I was reading the notes about domain 
> authentication, and how password-less authentication / win32 named pipes 
> connections, would require a lgpl compatible Unix implementation of the 
> smb ipc stuff (at least). Since this is something that really would help 

Looking deeper to the problem I can really say that I never see a
password-less authentication on Windows... usually password are "cached"
during login and windows have some stuff to login using this cached
login. There are some services that don't require authentication (ftp,
http, many unix daemons with particular configurations) but Windows
authentication require a password somewhere.
Named pipes use windows authentication to do the job (lm/ntlm/kerberos
usually). At this point however your *nix system should have some stuff
to store login password... I don't know if samba can do something
similar providing also ntlm support. Currently FreeTDS support either
kerberos and ntlm so "password-less" authentication can be done with
kerberos (ntlm require your password cause *nix don't have stuff to
store login password in a safe way... well... perhaps we could use
winbind in some way using ntlm_auth or the newer libwbclient, see
http://us3.samba.org/samba/ftp/pre/WHATSNEW-3-2-0pre3.txt, yes it's a
prerelease!)

> me out, I started looking into the issue some more. I have come up with 
> three possible avenues of approach: 1) conceivably using socat & 
> smbclient to forward a tcp port on the loopback adapter to the sql 
> server named pipe. 2) similar except use socat on *nix forward to child 
> ssh that logs into a 'doz box with cygwin sshd, then run socat inside 
> cygwin to forward stdio to the named pipe as a "regular" windows file. 
> 3) write special purpose windows and *nix utilities to forward a tcp (or 
> better yet unix domain socket) connection to the windows sql server 
> named pipe.  
>     My main question is this: For the sake of discussion lets say that 
> freetds could interface with a ms sql server over a windows named pipe. 
> How difficult would it be from there? Would this just turn into 
> man-years of examining wireshark dumps (which I noticed will do win 
> named pipes), or is it suppose to be the same wire level protocol?
> 

Well... you don't need either to use wireshark... you could port jcifs
(which is lgpl but java) to C... there are some projects that support
smb/cifs that are quite open (samba is gpl :( that is building FreeTDS
with samba code produce a gpl object that is to use this library your
application have to be gpl while using standard FreeTDS you have no
limit for your license) however the better IMHO is jCIFS.
However there has been very few requires for named pipes, the reason is
that mssql came (from 2000 version) with tcp protocol enabled so you can
do all with tcp (which is also faster)!
Time ago (some years) I spoke with Simo Sorce about moving some stuff to
lgpl but it tolds me that Andrew own most of copyrights (honestly I
never wrote to Andrew but if you want to try feels free). 

freddy77





More information about the FreeTDS mailing list