[linux-cifs-client] International characters in username/password

[Jeff Layton]

On Thu, 22 Apr 2010 08:38:40 -0500
Shirish Pargaonkar <shirishpargaonkar at gmail.com> wrote:

> On Thu, Apr 22, 2010 at 7:28 AM, Jeff Layton <jlayton at samba.org> wrote:
> > On Thu, 22 Apr 2010 10:58:03 +0100
> > Alex Zeffertt <alex.zeffertt at eu.citrix.com> wrote:
> >
> >> Hi all,
> >>
> >> Does anybody know how to get "mount.cifs -ocredentials=path/to/file" to work
> >> when there are international characters in the credentials file?
> >>
> >> I tested this with a password containing the £ (British pound) sign and I got
> >> the following error:
> >>
> >>    mount error 13 = Permission denied
> >>    Refer to the mount.cifs(8) manual page (e.g.man mount.cifs)
> >>
> >> The credentials file appears to be UTF-8, with all the characters one byte wide
> >> except for the "£" sign which is encoded as "0xc2 0xa3".
> >>
> >> I am using samba-client-3.0.33-3.15.el5_4.1 with linux-2.6.27 and Windows 2003
> >> Server to host the share.
> >>
> >> Regards,
> >>
> >> Alex
> >> _______________________________________________
> >> linux-cifs-client mailing list
> >> linux-cifs-client at lists.samba.org
> >> https://lists.samba.org/mailman/listinfo/linux-cifs-client
> >>
> >
> > mount.cifs and the kernel both pretty much treat the password as an
> > opaque sequence of bytes and don't really care what character set
> > they're in. The exception would be if you had a character with a NULL
> > byte embedded in it, which would probably trick them into truncating
> > the password. That doesn't sound like it's the case here.
> >
> > I think it's likely that the kernel routine that generates the NTLM
> > hashes in fs/cifs/smbencrypt.c is broken with respect to multibyte
> > characters. It seems to expect ASCII passwords, but I don't 100%
> > understand what it's doing at the moment.
> 
> E_md4hash converts passwords to Unicode but I am not sure
> whether it handles non-ascii characters in the password during conversion
> and how.
> 

The conversion to unicode seems to be very suspect (see _my_mbstowcs).
It doesn't call into the NLS routines, for instance but rather converts
each byte to a wide char using its own routine. This seems to be OK
with ASCII, but it probably falls down with a multibyte UTF8 char.

-- 
Jeff Layton <jlayton at samba.org>