[PATCHES] Fix userParameters once and for all

[Andrew Bartlett]

On Mon, 2014-06-30 at 18:47 +0200, Stefan (metze) Metzmacher wrote:
> Am 30.06.2014 00:07, schrieb Andrew Bartlett:
> > On Sun, 2014-06-29 at 23:57 +0200, Stefan (metze) Metzmacher wrote:
> >> Hi Andrew,
> >>
> >>>>> This patch series tries to fix the userParameters issue once and for all
> >>>>> rather than just papering over it by increasing the malloc buffer.
> >>>>>
> >>>>> This ensures that Samba stores the userParameters array in the same
> >>>>> way the windows client uses it, as a 'UTF-16-LE' buffer (sort of, the
> >>>>> data is not actually unicode).  
> >>>>>
> >>>>> The only thing not done in this patch set is to have our LDAP server
> >>>>> convert on output, but Microsoft assures us that this can not be
> >>>>> relied on anyway, as the data is not UTF8 nor can it be transformed to
> >>>>> UTF8 with certainty.
> >>>>>
> >>>>> Please review and push.
> >>>>
> >>>> I'll have a look at it next week...
> >>>
> >>> Any thoughts?
> >>
> >> I really would like to implement this like windows and provide
> >> the utf8 view over LDAP. Otherwise it's not "once and for all".
> > 
> > Perhaps, but this is still a necessary and required condition for this,
> > and as far as I propose to go at this time.
> > 
> > We already store and return this value over SAMR 'as is', and if we
> > don't merge these patches, we have memory corruption as Univention saw. 
> > 
> >> A while ago I started a test check the LDAP/SAMR interaction.
> >> https://git.samba.org/?p=metze/samba/wip.git;a=commitdiff;h=cc3aeb1fa904e58bb1e93ab0636048298a5f64e1
> >>
> >> It isn't just a start and we need to extend it to also check DRSUAPI.
> >>
> >> Once we have tests which demonstrate the real bahavior we might decide
> >> to leave out some features.
> >>
> >> Do we have real world examples where the userParameters field is set to
> >> values which can't be represented by utf8 in a lossless fashion?
> > 
> > We have the very strong assurance from Microsoft's engineers that this
> > value is not safely represented as UTF8. 
> > 
> > I don't have anything more than this for now, but the work I've done is,
> > in my view, a required pre-condition to further work here.  Leaving us
> > with memory corruption bugs or returning 'UTF8' data over SAMR is not an
> > acceptable state of affairs.  
> > 
> > None of this stops you doing further work on this, but as neither of us
> > got any further than this in the 6 months we have known about this
> > issue, leaving it totally broken for Samba 4.2 isn't an option. 
> > 
> > Therefore, I would request that we merge my changes, and that then you
> > build on top of that work when you have the time. 
> 
> Ok, I'll think about it for a few days. Please ping me again if
> got distracted.

Thank you,

Andrew Bartlett

-- 
Andrew Bartlett
http://samba.org/~abartlet/
Authentication Developer, Samba Team  http://samba.org
Samba Developer, Catalyst IT          http://catalyst.net.nz/services/samba



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