From: Bill Zissimopoulos <billziss@navimatics.com>
To: "cygwin@cygwin.com" <cygwin@cygwin.com>
Subject: Re: POSIX permission mapping and NULL SIDs
Date: Tue, 28 Jun 2016 19:17:00 -0000 [thread overview]
Message-ID: <D3980824.9862%billziss@navimatics.com> (raw)
In-Reply-To: <20160628102705.GA22797@calimero.vinschen.de>
On 6/28/16, 3:27 AM, "Corinna Vinschen" <cygwin-owner@cygwin.com on behalf
of corinna-cygwin@cygwin.com> wrote:
>>Ok. Please keep in mind that
>
>a) there can't be a bijective mapping between arbitrary length SIDs
> and a 32 bit uid/gid.
>
>b) The mapping used in Cygwin is not self-created but (mostly, except
> for a single deviation) identical to the Interix mapping. The code
> basically follows how this mapping has been defined by Microsoft.
Corinna, please stop explaining things to me that I already know.
>> BTW, I have here a partitioning of the UID namespace that may help
>>choose
>> the right mapping:
>>
>> /*
>> * UID namespace partitioning (from [IDMAP] rules):
>> *
>> * 0x000000 + RID S-1-5-RID,S-1-5-32-RID
>> * 0x000ffe OtherSession
>> * 0x000fff CurrentSession
>> * 0x001000 * X + RID S-1-5-X-RID ([WKSID]:
>> X=1-15,17-21,32,64,80,83)
>> * 0x010000 + 0x100 * X + Y S-1-X-Y ([WKSID]: X=1,2,3,4,5,9,16)
>> * 0x030000 + RID S-1-5-21-X-Y-Z-RID
>> * 0x060000 + RID S-1-16-RID
>> * 0x100000 + RID S-1-5-21-X-Y-Z-RID
>> */
>
>You're aware that I wrote the code for this mapping as well as its
>documentation? :)
Corinna, of course I am aware of that. I have found your original post to
this list about it. Why would you think otherwise? And why would it change
anything?
>>With all that and to help conclude this thread I gather here all the
>> proposed mappings. Corinna, I will use the one which you prefer the
>>most:
>>
>> S-1-0-65534 <-> 65534
>
>This one is still my favorite. Again, the range from 0x1000 up to
>0xffff is unused. Right now any incoming uid/gid value in this range
>for a reverse SID lookup is treated as invalid SID.
I disagree. You are saying that it is unused, but a (perhaps erroneous)
SID would map into that space.
In any case I will use your mapping of S-1-0-65534 <-> 65534.
Bill
next prev parent reply other threads:[~2016-06-28 18:06 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 [this message]
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
2016-06-30 9:26 ` Bill Zissimopoulos
2016-06-30 14:15 ` Corinna Vinschen
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