From: Corinna Vinschen <corinna-cygwin@cygwin.com>
To: cygwin@cygwin.com
Subject: Re: POSIX permission mapping and NULL SIDs
Date: Wed, 29 Jun 2016 16:06:00 -0000 [thread overview]
Message-ID: <20160629151322.GN981@calimero.vinschen.de> (raw)
In-Reply-To: <20160629134515.GL981@calimero.vinschen.de>
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On Jun 29 15:45, Corinna Vinschen wrote:
> Hi Bill,
>
> On Jun 29 10:21, Corinna Vinschen wrote:
> > On Jun 28 18:06, Bill Zissimopoulos wrote:
> > > In any case I will use your mapping of S-1-0-65534 <-> 65534.
> >
> > Thanks. Do you want to add handling for this mapping to
> > pwdgrp::fetch_account_from_windows yourself or shall I do it? I could
> > come up with a patch in the next couple of days. I will prepare a
> > developer's snapshot then, so you can immediately test if it works as
> > desired.
>
> How do we avoid name collisions? I can easily see admins creating an
> AD account called "nobody".
>
> Shall we fake a "WinFSP" domain such that the name is "WinFSP+nobody"?
Preliminary patch attached.
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Maintainer cygwin AT cygwin DOT com
Red Hat
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From a0bdba1cc4b8515e933e1c1caf59fcc310c48613 Mon Sep 17 00:00:00 2001
From: Corinna Vinschen <corinna@vinschen.de>
Date: Wed, 29 Jun 2016 17:12:38 +0200
Subject: [PATCH] Handle WinFSP nobody account
Per discussion started at
https://cygwin.com/ml/cygwin/2016-06/msg00347.html
S-1-0-65534 == WinFSP\nobody == WinFSP+nobody == uid/gid 65534
---
winsup/cygwin/uinfo.cc | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/winsup/cygwin/uinfo.cc b/winsup/cygwin/uinfo.cc
index 247131d..af1a4e5 100644
--- a/winsup/cygwin/uinfo.cc
+++ b/winsup/cygwin/uinfo.cc
@@ -1894,6 +1894,14 @@ pwdgrp::fetch_account_from_windows (fetch_user_arg_t &arg, cyg_ldap *pldap)
}
if (!ret)
{
+ if (!strcmp (arg.name, "WinFSP+nobody"))
+ {
+ /* Special case "nobody" for reproducible construction of a
+ nobody SID for WinFSP. We use the value 65534 which is
+ -2 with 16 bit uid/gids. */
+ csid.create (0, 1, 0xfffe);
+ break;
+ }
debug_printf ("LookupAccountNameW (%W), %E", name);
return NULL;
}
@@ -2004,6 +2012,15 @@ pwdgrp::fetch_account_from_windows (fetch_user_arg_t &arg, cyg_ldap *pldap)
sid = logon_sid;
break;
}
+ else if (arg.id == 0xfffe)
+ {
+ /* Special case "nobody" for reproducible construction of a
+ nobody SID for WinFSP. We use the value 65534 which is
+ -2 with 16 bit uid/gids. */
+ csid.create (0, 1, 0xfffe);
+ sid = csid;
+ break;
+ }
else if (arg.id < 0x10000)
{
/* Nothing. */
@@ -2428,6 +2445,14 @@ pwdgrp::fetch_account_from_windows (fetch_user_arg_t &arg, cyg_ldap *pldap)
return NULL;
}
}
+ else if (sid_id_auth (sid) == 0 && sid_sub_auth (sid, 0) == 0xfffe)
+ {
+ uid = gid = 0xfffe;
+ wcpcpy (dom, L"WinFSP");
+ wcpcpy (name = namebuf, L"nobody");
+ fully_qualified_name = true;
+ acc_type = SidTypeUnknown;
+ }
else if (sid_id_auth (sid) == 5 /* SECURITY_NT_AUTHORITY */
&& sid_sub_auth (sid, 0) == SECURITY_LOGON_IDS_RID)
{
--
2.5.5
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next prev parent reply other threads:[~2016-06-29 15:13 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-24 19:02 Bill Zissimopoulos
2016-06-24 21:37 ` Corinna Vinschen
2016-06-24 22:00 ` Corinna Vinschen
2016-06-24 22:06 ` Bill Zissimopoulos
2016-06-24 22:31 ` Corinna Vinschen
2016-06-24 22:36 ` Erik Soderquist
2016-06-24 23:03 ` Bill Zissimopoulos
2016-06-24 23:51 ` Bill Zissimopoulos
2016-06-27 13:20 ` Corinna Vinschen
2016-06-24 22:53 ` Bill Zissimopoulos
2016-06-25 17:10 ` Brian Inglis
2016-06-27 10:26 ` Bill Zissimopoulos
2016-06-27 10:29 ` Andrey Repin
2016-06-27 12:06 ` Corinna Vinschen
2016-06-27 20:31 ` Bill Zissimopoulos
2016-06-28 11:08 ` Corinna Vinschen
2016-06-28 19:17 ` Bill Zissimopoulos
2016-06-28 19:17 ` John Ruckstuhl
2016-06-29 8:43 ` Corinna Vinschen
2016-06-29 15:14 ` Corinna Vinschen
2016-06-29 16:06 ` Corinna Vinschen [this message]
2016-06-30 9:26 ` Bill Zissimopoulos
2016-06-30 14:15 ` Corinna Vinschen
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