Re: user guide draft: "SELinux Contexts and Attributes" review

[Murray McAllister <mmcallis@redhat.com>]

Stephen Smalley wrote:
> On Fri, 2008-09-05 at 15:46 +1000, Murray McAllister wrote:
>> Stephen Smalley wrote:
>>> On Wed, 2008-09-03 at 16:04 +1000, Murray McAllister wrote:
>>>> How about:
>>>>
>>>> The level is an attribute of MLS and Multi-Category Security (MCS). The 
>>>> first part of the level, s0-s0, is the sensitivity.
>>> Actually, s0-s0 is a MLS range where the low level has sensitivity s0
>>> and no categories and the high level has sensitivity s0 and no
>>> categories.
>>>
>>>>  The s0 sensitivity 
>>>> is the only sensitivity used for MCS. Since the format of the level is 
>>>> the same for MLS and MCS, and MLS supports ranges of sensitivities, a 
>>>> sensitivity such as s0-s0 is the same as s0 when using MCS.
>>> No, s0-s0 is always the same as just s0, regardless of MCS or MLS.  Just
>>> like s1-s1 is the same as just s1.  Versus a non-trivial range like
>>> s0-s1 or s0-s3.
>>>
>>>>  Optionally, 
>>>> the level can have a list of categories.
>> I hope this is correct soon ;)
>>
>> The level is an attribute of MLS and Multi-Category Security (MCS). The 
>> first part of the level, s0-s0, is an MLS range.
> 
> s0-s0 is a range.  It is not a level.  A MLS range is a pair of levels
> (lowlevel, highlevel) written as "lowlevel-highlevel" if they differ or
> as just "lowlevel" if they are the identical.  Each level is a
> (sensitivity, categoryset) pair written as "sensitivity:categoryset" or
> just "sensitivity" if the category set is empty.  A categoryset is a
> list of categories written as "category1,category2,...".  If a category
> set contains a contiguous series of categories (e.g.
> "c1,c2,c3,c4,c5,c6,c7,c8,c9,c10") this can be abbreviated as the first
> category in the series followed by a dot (".") followed by the last
> category in the series, e.g. "c1.c10".
> 
> s0-s0 is a range where the lowlevel == highlevel == (sensitivity s0,
> emptycategoryset).
> 

If it is not right this time, it's being deleted ;)

level: The level[1] is an attribute of MLS and Multi-Category Security 
(MCS). An MLS range is a pair of levels, written as lowlevel-highlevel 
if the levels differ, or lowlevel if the levels are identical (s0-s0 is 
the same as s0). Each level is a sensitivity-category pair, with 
categories being optional. If there are categories, the level is written 
as sensitivity:category-set. If there are no categories, it is written 
as sensitivity. If the category set is a contiguous series, it can be 
abbreviated. For example, c0.c3 is the same as c0,c1,c2,c3. The 
/etc/selinux/targeted/setrans.conf file is used to map levels (s0:c0) to 
human-readable form (CompanyConfidential).


[1] talking about all of the output (s0-s0:c0.c1023
) from semanage login -l

--
This message was distributed to subscribers of the selinux mailing list.
If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
the words "unsubscribe selinux" without quotes as the message.