X-Recipient: archive-cygwin AT delorie DOT com
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 810A23858283
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1708801053;
	bh=igA+B1OH5UriyU8d8OrGKnCsrGtjwS3K+z7jPrr9Fu4=;
	h=Date:To:Subject:References:In-Reply-To:List-Id:List-Unsubscribe:
	 List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc:
	 From;
	b=ByNu9gUYRcThTaxVFjdbHkkcKYIdj1az7qBdye7qtGPqLoxyrCRmgm/HY9QqJ8emq
	 k3dkfGdDn1L7bl9JjRBDIc+oUNMEWXSbQHbnQf7x/hvSLFbDz186qR5QW3C/iAkj6b
	 6jC4Ao7DrqM7+hwb2Z7MF3F/Jm+m7LelqMBU5ARo=
X-Original-To: cygwin AT cygwin DOT com
Delivered-To: cygwin AT cygwin DOT com
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9D52C3858D34
Date: Sat, 24 Feb 2024 19:57:11 +0100
To: cygwin AT cygwin DOT com
Subject: Re: Will all SIDs fit into |SECURITY_MAX_SID_SIZE| bytes ? / was:
 Re: Switching groups with newgrp - how to get the new group with
 |GetTokenInformation()| ?
Message-ID: <Zdo8B-IhG_dYAjGo@calimero.vinschen.de>
Mail-Followup-To: cygwin AT cygwin DOT com
References: <CAKAoaQnFxij4Np-jg+bOLEpiSziCfamFrJ2FR_JeO+Sv_Td2Kg AT mail DOT gmail DOT com>
 <ZdecXZNUgQ3i0hYN AT calimero DOT vinschen DOT de>
 <CAKAoaQk39bKbG0a_sZAR2KKz5f4U04xc=499YibfbdLesxC4Vg AT mail DOT gmail DOT com>
MIME-Version: 1.0
Content-Disposition: inline
In-Reply-To: <CAKAoaQk39bKbG0a_sZAR2KKz5f4U04xc=499YibfbdLesxC4Vg@mail.gmail.com>
X-BeenThere: cygwin AT cygwin DOT com
X-Mailman-Version: 2.1.30
Precedence: list
List-Id: General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe: <https://cygwin.com/mailman/options/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=unsubscribe>
List-Archive: <https://cygwin.com/pipermail/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe: <https://cygwin.com/mailman/listinfo/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From: Corinna Vinschen via Cygwin <cygwin AT cygwin DOT com>
Reply-To: cygwin AT cygwin DOT com
Cc: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
Content-Type: text/plain; charset="utf-8"
Errors-To: cygwin-bounces+archive-cygwin=delorie DOT com AT cygwin DOT com
Sender: "Cygwin" <cygwin-bounces+archive-cygwin=delorie DOT com AT cygwin DOT com>
Content-Transfer-Encoding: 8bit
X-MIME-Autoconverted: from base64 to 8bit by delorie.com id 41OIvZrI023324

On Feb 24 15:38, Roland Mainz via Cygwin wrote:
> On Thu, Feb 22, 2024 at 8:11 PM Corinna Vinschen via Cygwin
> <cygwin AT cygwin DOT com> wrote:
> > On Feb 22 18:38, Roland Mainz via Cygwin wrote:
> > > If I switch the current user's group with /usr/bin/newgrp, how can a
> > > (native) Win32 process use
> > > |GetTokenInformation(GetCurrentThreadToken(), ...)| to find out which
> > > group is the new "current group" (e.g. which |TokenInformationClass|
> > > should I use) ?
> >
> >   PSID sidbuf = (PSID) alloca (SECURITY_MAX_SID_SIZE);
> [snip]
> 
> Win32/NT API question: All known SIDs will fit into
> |SECURITY_MAX_SID_SIZE| bytes, right ? I'm asking because right now
> the ms-nfs41-client code assumes that all SIDs use a variable amount
> of memory, and we always have to ask the Win32/NT API about the number
> of bytes to allocate. If |SECURITY_MAX_SID_SIZE| is the global maximum
> limit for all Windows versions, then we could simplify the code a
> lot...

Yes.  ACLs are size restricted to 64K, though, but that shouldn't be
much of a problem usally.


Corinna

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple