delorie.com/archives/browse.cgi   search  
Mail Archives: cygwin/2014/12/15/06:36:02

X-Recipient: archive-cygwin AT delorie DOT com
DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
:list-unsubscribe:list-subscribe:list-archive:list-post
:list-help:sender:date:from:to:subject:message-id:reply-to
:references:mime-version:content-type:in-reply-to; q=dns; s=
default; b=QeLz+1yliKoNm2n6r+x6YN8/8BhDeiMOpEAzFN167FHCMLaHXIo5W
vPOF5nbYmG28CCwVLPULK0YFKevT8HOC2qCfD/7XBMKsHg1EFqM7WJ49HIIZi3ES
klOzBgET0IepmxFQUA3UKGk3p46Pqeau+u1Hg86hncAKjWRCXRo3IQ=
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
:list-unsubscribe:list-subscribe:list-archive:list-post
:list-help:sender:date:from:to:subject:message-id:reply-to
:references:mime-version:content-type:in-reply-to; s=default;
bh=iHnEEXHWn15OU6rs6xUytk7ksjM=; b=sH7Mp+E663y6Y8ZuWTBTajSgb/uF
4GDUMJuRntUBnz8fxoG28tyGTRQUa5GBPTqeiNfZbWmdFs9Epd1Wk36aUh3EY/py
5hx76ECdtMCmB4zcQ29/x6jjrMqvxiZG4bL8QuNnFgpogEC9W9ufyYpZf5QT4ATy
h5pgswIQOdaB8g4=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
Authentication-Results: sourceware.org; auth=none
X-Virus-Found: No
X-Spam-SWARE-Status: No, score=-5.9 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=3.3.2
X-HELO: calimero.vinschen.de
Date: Mon, 15 Dec 2014 12:35:42 +0100
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: TEST RELEASE: Cygwin 1.7.34-002
Message-ID: <20141215113542.GE11307@calimero.vinschen.de>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <20141206194943 DOT GD3810 AT calimero DOT vinschen DOT de> <CAMKht8iYnRuAJ7Eau6LDa_Jszxwo8YwybzwZNHjzWXLMUS8Y-w AT mail DOT gmail DOT com> <548AFD43 DOT 1040306 AT cornell DOT edu>
MIME-Version: 1.0
In-Reply-To: <548AFD43.1040306@cornell.edu>
User-Agent: Mutt/1.5.23 (2014-03-12)

--maH1Gajj2nflutpK
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Dec 12 09:35, Ken Brown wrote:
> On 12/12/2014 8:49 AM, Michael DePaulo wrote:
> >On Sat, Dec 6, 2014 at 2:49 PM, Corinna Vinschen
> ><corinna-cygwin AT cygwin DOT com> wrote:
> >>I finally released another TEST version of the next upcoming Cygwin
> >>release.  The version number is 1.7.34-002.
> >
> >I *think* I am experiencing a very bad regression.
> >
> >These are the Windows permissions on my ~/.ssh/id_rsa file:
> >C:\cygwin\home\mike\.ssh>icacls id_rsa
> >id_rsa NT AUTHORITY\SYSTEM:(F)
> >        DEPAULO\mike:(R,W,D,WDAC,WO)
> >[...]
> >$ uname -a
> >CYGWIN_NT-6.3-WOW64 executor 1.7.34(0.282/5/3) 2014-12-06 18:03 i686 Cyg=
win
> >
> >mike AT executor ~
> >$ ssh galactica
> >@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
> >@         WARNING: UNPROTECTED PRIVATE KEY FILE!          @
> >@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
> >Permissions 0670 for '/home/mike/.ssh/id_rsa' are too open.
> >It is recommended that your private key files are NOT accessible by othe=
rs.
> >This private key will be ignored.
> >key_load_private_type: bad permissions
> >[...]
> >mike AT executor ~/.ssh
> >$ ls -latr id_rsa
> >-rw-rwx---+ 1 mike Domain Users 1743 Dec  7  2013 id_rsa
>=20
> This isn't a regression.  It's a deliberate change, so that Cygwin now ta=
kes
> ACLs into account when calculating permissions.  The simplest fix is to u=
se
> the new feature of setfacl to remove the unwanted permissions.  From the
> release announcement:
>=20
> >- Add -b/--remove-all option to setfacl to reduce the ACL to only the
> >  entries representing POSIX permission bits.
>=20
> Ken

What he says.  Here are the important snippets from the POSIX ACL Linux
man page (for instance http://linux.die.net/man/5/acl), which was never
before implemented in Cygwin, but which is with the test release (and
thus the upcoming release):

  An ACL that contains entries of ACL_USER or ACL_GROUP tag types must
  contain exactly one entry of the ACL_MASK tag type.

Windows doesn't support MASK entries.  But POSIX requires a MASK entry
if a supplementary user or group has an ACL entry, thus Cygwin emulates
the entry.

  The ACL_MASK entry denotes the maximum access rights that can be
  granted by entries of type ACL_USER, ACL_GROUP_OBJ, or ACL_GROUP.=20

So the emulated MASK entry is the or'ed mask of all permissions granted
to the primary group and all supplementary users and groups.

  There is a correspondence between the file owner, group, and other
  permissions and specific ACL entries:
  [...]
  If the ACL has an ACL_MASK entry, the group permissions correspond to
  the permissions of the ACL_MASK entry.

So, the group permissions don't simply reflect the permissions of the
primary group, but the sum of permissions of the primary group and all
supplementary users and groups in the ACL.

It's unfortunate that this may break more installations, but it's also a
security improvment.  The group permissions reflect the fact that the
permissions granted to your ssh key are too open.  Fortunately the new
-b option to setfacl allows a quick fix.


Corinna

--=20
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

--maH1Gajj2nflutpK
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
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=VB5m
-----END PGP SIGNATURE-----

--maH1Gajj2nflutpK--

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019