Skip top menus
National Security Agency and Central Security Service with agency logos.NSA/CSS Memorial Wall
Home    About NSA    Research    Business    Careers    Public Info    History
Introduction to Research    Security-Enhanced Linux    Information Assurance Research    Technology Transfer    Publications    Related Links

>>SELinux Mailing List: by thread

Search
What's new?
Contents
Overview
What's New
Frequently Asked Questions
Background
Documentation
License
Download
Participating
Mail List
Archive Summary
Archive by Thread
Archive by Author
Archive by Date
Archive by Subject
Remaining Work
Contributors
Related Work
Press Releases
  • Contemporary messages sorted: [ by date ] [ by thread ] [ by subject ] [ by author ]
From: Frank Mayer <mayerf_at_tresys.com>
subject: Security policy analysis
Date: Tue, 9 Oct 2001 15:49:31 -0400
  • This message: [ Message body ]
  • Next message: John Scroggins: "RE: Security policy analysis"
  • Previous message: Stephen Smalley: "Re: ssh, ad nauseum"
  • Next in thread: John Scroggins: "RE: Security policy analysis"
  • Reply: John Scroggins: "RE: Security policy analysis"
  • Reply: Ravi Prakash B.V.: "Interested in Reserach work"
  • Reply: Stephen Smalley: "Re: Security policy analysis"


We're looking at SE Linux as a building block upon which we can build protected applications of various types. One of the issues we are working through include identifying a core "baseline" Linux configuration and associated SE Linux policy for that baseline. One means of doing this is to examine sample policies (like the one distributed with the source). If anyone else is doing similar things, we'd like to like to hear more. Also, is anyone else working on alternative sample policies, especially for a core Linux configuration?

We also find ourselves incrementally building tools to analyze policy.conf files (e.g., show all types with a given attribute, show all rules that involve a given type/attribute). Essentially to help reverse engineer and analyze the intent of a given policy. We have some capabilities built, and are writing additional ones as time and need allow (essentially by borrowing the lex/yacc source from checkpolicy, and building our own policy database and analysis logic). Is anyone else building similar tools? We'd be happy to share our source incrementally with members of the list as we build new capabilities if anyone is interested.

PS- Please reply to the mail list; we'd like to start open discussions of policy analysis and development.

Regards,
Frank Mayer
mayerf@tresys.com
Tresys Technology

--
You have received this message because you are subscribed to the selinux 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.
From: John Scroggins <dataefx_at_earthlink.net>
subject: RE: Security policy analysis
Date: Tue, 9 Oct 2001 16:32:38 -0700
  • This message: [ Message body ]
  • Next message: Ravi Prakash B.V.: "Interested in Reserach work"
  • Previous message: Frank Mayer: "Security policy analysis"
  • In reply to: Frank Mayer: "Security policy analysis"
  • Next in thread: Ravi Prakash B.V.: "Interested in Reserach work"


We're looking at SE Linux as a building block upon which we can build protected applications of various types. One of the issues we are working through include identifying a core "baseline" Linux configuration and associated SE Linux policy for that baseline. One means of doing this is to examine sample policies (like the one distributed with the source). If anyone else is doing similar things, we'd like to like to hear more. Also, is anyone else working on alternative sample policies, especially for a core Linux configuration?

I am not sure if anyone is doing so at the present time, but the direction you are heading is interesting.. As it would help to broaden the use of the kernel in general by supplying those "sample policies". I think one of the hindrances in a large deployment scenario is understanding the policy structure(s) and how they apply to processes (that require protection). A more extensive set of elements which would help guide the potential user,(admin or engineer) in defining environment specific variables, may be a welcome addition.

We also find ourselves incrementally building tools to analyze policy.conf files (e.g., show all types with a given attribute, show all rules that involve a given type/attribute). Essentially to help reverse engineer and analyze the intent of a given policy. We have some capabilities built, and are writing additional ones as time and need allow (essentially by borrowing the lex/yacc source from checkpolicy, and building our own policy database and analysis logic).

I see this as potentially valuable. I too, would also like to see an extended discussion regarding this resource.

Is anyone else building similar tools? We'd be happy to share our source incrementally with members of the list as we build new capabilities if anyone is interested.

Integrating this into a kernel-building utility sounds interesting. :)

PS- Please reply to the mail list; we'd like to start open discussions of policy analysis and development.

Regards,
Frank Mayer
mayerf@tresys.com
Tresys Technology

--

You have received this message because you are subscribed to the selinux 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.

--

You have received this message because you are subscribed to the selinux 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.

From: Ravi Prakash B.V. <ravi_at_atc.tcs.co.in>
subject: Interested in Reserach work
Date: Wed, 10 Oct 2001 11:35:34 +0530
  • This message: [ Message body ]
  • Next message: Stephen Smalley: "Re: Security policy analysis"
  • Previous message: John Scroggins: "RE: Security policy analysis"
  • In reply to: Frank Mayer: "Security policy analysis"
  • Next in thread: Stephen Smalley: "Re: Security policy analysis"


Dear all,

I joined into this group today.
I am interested to do the research work in security area. I want to contribute my research work to this group. I would like to know the current active work in the group so that i can join and start work in one of it.

Thanks & Regards,
Ravi Prakash B.V.

--
You have received this message because you are subscribed to the selinux 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.
From: Stephen Smalley <sds_at_tislabs.com>
subject: Re: Security policy analysis
Date: Wed, 10 Oct 2001 08:26:09 -0400 (EDT)
  • This message: [ Message body ]
  • Next message: Carl Carpenter: "Problems with eth0"
  • Previous message: Ravi Prakash B.V.: "Interested in Reserach work"
  • In reply to: Frank Mayer: "Security policy analysis"
  • Next in thread: ipv6: "Re: Security policy analysis"
  • Reply: ipv6: "Re: Security policy analysis"
  • Reply: Jon Crowley: "Re: Security policy analysis"

On Tue, 9 Oct 2001, Frank Mayer wrote:

> We also find ourselves incrementally building tools to analyze policy.conf
> files (e.g., show all types with a given attribute, show all rules that
> involve a given type/attribute). Essentially to help reverse engineer and
> analyze the intent of a given policy. We have some capabilities built, and
> are writing additional ones as time and need allow (essentially by borrowing
> the lex/yacc source from checkpolicy, and building our own policy database
> and analysis logic). Is anyone else building similar tools? We'd be happy
> to share our source incrementally with members of the list as we build new
> capabilities if anyone is interested.

Some people at MITRE have been working on similar policy analysis tools. Originally, they were creating these tools separately from checkpolicy but drawing from the checkpolicy sources. However, I recommended that they instead look into merging the support for new kinds of queries directly into the existing checkpolicy debugging facility (the -d option) and possibly replacing the checkpolicy debugging interface with an interactive query interface. I'm not sure how far along they are, but you should certainly coordinate.

We're interested in the capabilities that you've developed. Can we acquire a copy?

--
Stephen D. Smalley, NAI Labs
ssmalley@nai.com




--
You have received this message because you are subscribed to the selinux 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.
From: ipv6 <ipv6_at_311c.com>
subject: Re: Security policy analysis
Date: Wed, 10 Oct 2001 08:23:07 -0600
  • This message: [ Message body ]
  • Next message: Frank Mayer: "RE: Security policy analysis"
  • Previous message: Stephen Smalley: "Re: Problems with eth0"
  • In reply to: Stephen Smalley: "Re: Security policy analysis"
  • Next in thread: Frank Mayer: "RE: Security policy analysis"
  • Reply: Frank Mayer: "RE: Security policy analysis"
  • Reply: EZ: "Re: Security policy analysis"

>
> On Tue, 9 Oct 2001, Frank Mayer wrote:
>
> > We also find ourselves incrementally building tools to analyze
policy.conf
> > files (e.g., show all types with a given attribute, show all rules that
> > involve a given type/attribute). Essentially to help reverse engineer
and
> > analyze the intent of a given policy. We have some capabilities built,
and
> > are writing additional ones as time and need allow (essentially by
borrowing
> > the lex/yacc source from checkpolicy, and building our own policy
database
> > and analysis logic). Is anyone else building similar tools? We'd be
happy
> > to share our source incrementally with members of the list as we build
new
> > capabilities if anyone is interested.

> We're interested in the capabilities that you've developed. Can we
> acquire a copy?

We would also like to get a copy if that is possible?

Joop Cousteau
CTO
ImageSave Corp

--
You have received this message because you are subscribed to the selinux 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.
From: Frank Mayer <mayerf_at_tresys.com>
subject: RE: Security policy analysis
Date: Wed, 10 Oct 2001 10:39:42 -0400
  • This message: [ Message body ]
  • Next message: Justin R. Smith: "Vanilla unix policy"
  • Previous message: ipv6: "Re: Security policy analysis"
  • In reply to: ipv6: "Re: Security policy analysis"
  • Next in thread: Julien Palardy: "Re: Security policy analysis"
  • Reply: Julien Palardy: "Re: Security policy analysis"


I will post a site where the current source can be downloaded within a day or two.

However, I still encourage folks who are looking at developing or analyzing security policies to share any insights you might have. Thanks

Frank Mayer
mayerf@tresys.com
Tresys Technology

--
You have received this message because you are subscribed to the selinux 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.
From: Julien Palardy <palj_at_praefect-sys.com>
subject: Re: Security policy analysis
Date: Wed, 10 Oct 2001 14:50:58 +0200
  • This message: [ Message body ]
  • Next message: Julien Palardy: "Re: Problems with eth0"
  • Previous message: Frank Mayer: "RE: Security policy analysis"
  • In reply to: Frank Mayer: "RE: Security policy analysis"
  • Next in thread: EZ: "Re: Security policy analysis"

You have any detail on the licensing form of the code? I am highly interested in any policy reverse-engineering mechanism, and even more in policy engineering itself, which can probably be much more useful at this stage of SELinux's developement.

---
Julien Palardy <palj@praefect-sys.com>
1AC7 1DB0 FEA6 93C2 6731  0AB1 07BA B3C7 458E E234



> I will post a site where the current source can be downloaded within a day
> or two.
>
> However, I still encourage folks who are looking at developing or
analyzing
> security policies to share any insights you might have. Thanks
>
> Frank Mayer
> mayerf@tresys.com
> Tresys Technology
>
-- You have received this message because you are subscribed to the selinux 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.
From: EZ <papaz_at_md.prestige.net>
subject: Re: Security policy analysis
Date: Wed, 10 Oct 2001 13:52:24 -0400
  • This message: [ Message body ]
  • Next message: Frank Mayer: "RE: Security policy analysis"
  • Previous message: Jon Crowley: "Re: Security policy analysis"
  • In reply to: ipv6: "Re: Security policy analysis"
  • Next in thread: ipv6: "Re: Security policy analysis"
  • Reply: ipv6: "Re: Security policy analysis"


Same here...a copy would be great!

Edmund Zynda II

  • Original Message ----- From: "ipv6" <ipv6@311c.com> To: "Stephen Smalley" <sds@tislabs.com>; "Frank Mayer" <mayerf@tresys.com> Cc: <SELinux@tycho.nsa.gov> Sent: Wednesday, October 10, 2001 10:23 AM Subject: Re: Security policy analysis

>
>
>
> >
> > On Tue, 9 Oct 2001, Frank Mayer wrote:
> >
> > > We also find ourselves incrementally building tools to analyze
> policy.conf
> > > files (e.g., show all types with a given attribute, show all rules
that
> > > involve a given type/attribute). Essentially to help reverse engineer
> and
> > > analyze the intent of a given policy. We have some capabilities
built,
> and
> > > are writing additional ones as time and need allow (essentially by
> borrowing
> > > the lex/yacc source from checkpolicy, and building our own policy
> database
> > > and analysis logic). Is anyone else building similar tools? We'd be
> happy
> > > to share our source incrementally with members of the list as we build
> new
> > > capabilities if anyone is interested.
>
> > We're interested in the capabilities that you've developed. Can we
> > acquire a copy?
>
> We would also like to get a copy if that is possible?
>
> Joop Cousteau
> CTO
> ImageSave Corp
>
>
>
> --
> You have received this message because you are subscribed to the selinux
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.

--
You have received this message because you are subscribed to the selinux 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.
From: ipv6 <ipv6_at_311c.com>
subject: Re: Security policy analysis
Date: Wed, 10 Oct 2001 13:40:45 -0600
  • This message: [ Message body ]
  • Next message: Frank Mayer: "RE: Security policy analysis"
  • Previous message: Stephen Smalley: "Re: Vanilla unix policy"
  • In reply to: EZ: "Re: Security policy analysis"
  • Next in thread: Jon Crowley: "Re: Security policy analysis"


OK !!!! We all agree - please send a copy ! This is a Great Group of people !

  • Original Message ----- From: "EZ" <papaz@md.prestige.net> To: "ipv6" <ipv6@311c.com>; "Stephen Smalley" <sds@tislabs.com>; "Frank Mayer" <mayerf@tresys.com> Cc: <SELinux@tycho.nsa.gov> Sent: Wednesday, October 10, 2001 11:52 Subject: Re: Security policy analysis

> Same here...a copy would be great!
>
> Edmund Zynda II
>
> ----- Original Message -----
> From: "ipv6" <ipv6@311c.com>
> To: "Stephen Smalley" <sds@tislabs.com>; "Frank Mayer" <mayerf@tresys.com>
> Cc: <SELinux@tycho.nsa.gov>
> Sent: Wednesday, October 10, 2001 10:23 AM
> Subject: Re: Security policy analysis
>
>
> >
> >
> >
> > >
> > > On Tue, 9 Oct 2001, Frank Mayer wrote:
> > >
> > > > We also find ourselves incrementally building tools to analyze
> > policy.conf
> > > > files (e.g., show all types with a given attribute, show all rules
> that
> > > > involve a given type/attribute). Essentially to help reverse
engineer
> > and
> > > > analyze the intent of a given policy. We have some capabilities
> built,
> > and
> > > > are writing additional ones as time and need allow (essentially by
> > borrowing
> > > > the lex/yacc source from checkpolicy, and building our own policy
> > database
> > > > and analysis logic). Is anyone else building similar tools? We'd
be
> > happy
> > > > to share our source incrementally with members of the list as we
build
> > new
> > > > capabilities if anyone is interested.
> >
> > > We're interested in the capabilities that you've developed. Can we
> > > acquire a copy?
> >
> > We would also like to get a copy if that is possible?
> >
> > Joop Cousteau
> > CTO
> > ImageSave Corp
> >
> >
> >
> > --
> > You have received this message because you are subscribed to the selinux
> 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.
>
>
> --
> You have received this message because you are subscribed to the selinux
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.
>

--
You have received this message because you are subscribed to the selinux 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.
From: Jon Crowley <jonathan_at_mitre.org>
subject: Re: Security policy analysis
Date: Wed, 10 Oct 2001 13:02:20 -0400
  • This message: [ Message body ]
  • Next message: EZ: "Re: Security policy analysis"
  • Previous message: Justin R. Smith: "Vanilla unix policy"
  • In reply to: Stephen Smalley: "Re: Security policy analysis"
  • Next in thread: Frank Mayer: "RE: Security policy analysis"
  • Reply: Frank Mayer: "RE: Security policy analysis"
  • Reply: Stephen Smalley: "Re: Security policy analysis"


> Some people at MITRE have been working on similar policy analysis tools.

Yes, MITRE is developing tools for policy analysis.

We intend on developing functions to do the following first:

  1. List the process transitions for type "T"
  2. List the file transitions for type "T"
  3. List the type enforcement entries for type "T"
  4. List all roles for type "T"
  5. List all roles to which role "R" can transition
  6. List all roles that can transition to role "R"
  7. List all types with permission "P" in class "C" to type "T"
  8. List all types with attribute "A".
  9. List contexts with attribute "A".
  10. Which policy rule is blocking a particular permission "P" between two contexts "C1" and "C2"?
  11. Trace how a process in context C1 gains access (as a set of one or more permissions) to an object with context C2.
  12. Which file does rule "R" come from? (And where in that file is it?)
  13. List all equivalent types in the policy. Already done in checkpolicy.c, but may need refinement.
  14. Show the difference(s) between type "T1" and "T2" in the policy.
  15. Identify types that are within some "delta" of each other in the policy. Useful for identifying possibly redundant types.
  16. List all process types reachable from type "T" and show the path to them.
  17. List all object types to which data of type "T" can flow and show the path to them.
  18. Graph (or describe) all paths by which data might flow from type "T1" to type "T2"

For testing purposes, we implemented some of these functions (1-6, 7 under construction) as small, individual programs borrowing code from checkpolicy sources. Eventually we would like to combine these programs into one tool that provides policy analysis capabilities. Because we see the above list as growing and want it to be as flexible as possible to be able to handle tailored requests from the policy administrator, we plan on implementing an interactive query language front-end to this tool, as Steve suggested.

Steve also suggested incorporating these functions into checkpolicy. With the interactive query front-end, this would become the policy analysis tool. However, our take on checkpolicy is that it is intended to compile policies and to assist in debugging specific to security identifiers. We are thinking it might be cleaner to keep policy analysis tools separate from a policy compiling/debugging tool. Though perhaps we have the wrong take on checkpolicy. More thoughts on this?

The problem with building a separate tool is that both tools will share some of the same code. Does it makes sense to pull out commonly-used code in checkpolicy, specifically the code that reads in the binary and text versions of the policy into data structures, and put this code into some sort of library? It seems this code may be useful to future applications, and it would be easier to maintain and more accessible if it was in a library.

Jon Crowley
MITRE Corporation

--
You have received this message because you are subscribed to the selinux 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.
From: Frank Mayer <mayerf_at_tresys.com>
subject: RE: Security policy analysis
Date: Wed, 10 Oct 2001 14:09:14 -0400
  • This message: [ Message body ]
  • Next message: Julien Palardy: "Re: Security policy analysis"
  • Previous message: EZ: "Re: Security policy analysis"
  • In reply to: Jon Crowley: "Re: Security policy analysis"
  • Next in thread: Stephen Smalley: "RE: Security policy analysis"
  • Reply: Stephen Smalley: "RE: Security policy analysis"


> From: root@smtpsrv1.mitre.org [mailto:root@smtpsrv1.mitre.org]On Behalf
> Of Jon Crowley
> Sent: Wednesday, October 10, 2001 1:02 PM
>
> We intend on developing functions to do the following first:
>
> <list deleted>

We have very similar thoughts, though our goal is to define a building block policy configuration for SE Linux and then methods for building upon that building block for a variety of applications. The analysis tool is a by-product.

> However, our take on checkpolicy is that it is intended
> to compile policies and to assist in debugging specific to security
> identifiers. We are thinking it might be cleaner to keep policy
> analysis tools separate from a policy compiling/debugging tool. Though
> perhaps we have the wrong take on checkpolicy. More thoughts on this?

We looked quickly at checkpolicy and came to the same conclusion, i.e., that it
compiles policies for a different reason and has a policy DB not suited for our purpose. That's not a strong opinion. We're also just incrementally building quick tools and creating our own database format was simpler. The only code we're currently using from checkpolicy is the lex code, the yacc framework and parser (though all the semantic logic is new), and the associated queue.c. However, it is conceptually simple to integrate our logic into checkpolicy
if we wanted to. Essentially we would just add our logic to the functions already in policy_parse.y, with changes to the main() function in checkpolicy.c
for our menu items plus a few other housekeeping items.

I will also say that our analysis policy structure is quick and dirty without
much effort spent on performance issues like sorted insertions and searches. It
hasn't been any issue since once we digest the policy and build the policy DB,
everything else is fast enough (we don't have the burden of building a kernel
database like checkpolicy does!)

--
You have received this message because you are subscribed to the selinux 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.
From: Stephen Smalley <sds_at_tislabs.com>
subject: RE: Security policy analysis
Date: Wed, 10 Oct 2001 15:32:25 -0400 (EDT)
  • This message: [ Message body ]
  • Next message: Stephen Smalley: "Re: Vanilla unix policy"
  • Previous message: Stephen Smalley: "Re: Security policy analysis"
  • In reply to: Frank Mayer: "RE: Security policy analysis"
  • Next in thread: Frank Mayer: "RE: Security policy analysis"
  • Reply: Frank Mayer: "RE: Security policy analysis"
  • Reply: Frank Mayer: "RE: Security policy analysis"

On Wed, 10 Oct 2001, Frank Mayer wrote:

>We looked quickly at checkpolicy and came to the same conclusion, i.e., that
>it compiles policies for a different reason and has a policy DB not
>suited for our purpose. That's not a strong opinion.

So perhaps checkpolicy needs to be revised to generate an intermediate set of data structures that are more suitable for policy analysis tools prior to generating the final set of data structures for the kernel security server?

--
Stephen D. Smalley, NAI Labs
ssmalley@nai.com




--
You have received this message because you are subscribed to the selinux 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.
From: Frank Mayer <mayerf_at_tresys.com>
subject: RE: Security policy analysis
Date: Wed, 10 Oct 2001 16:11:31 -0400
  • This message: [ Message body ]
  • Next message: Frank Mayer: "RE: Security policy analysis"
  • Previous message: ipv6: "Re: Security policy analysis"
  • In reply to: Stephen Smalley: "RE: Security policy analysis"
  • Next in thread: Frank Mayer: "RE: Security policy analysis"
  • Reply: Frank Mayer: "RE: Security policy analysis"


Ok, we've made our source available. First let me lower expectations. This is a small, quickly built tool with limited and evolving capabilities that I wrote only as a by-product of our real effort. From the messages I've read today, too many people seem to be reading too much into all of this. Also, someone asked about license. We just quickly put this under a GNU GPL and added the appropriate (C) statements, primarily to give us the liability protection.

You can download the tar file at http://www.tresys.com/selinux.html

Frank

--
You have received this message because you are subscribed to the selinux 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.
From: Frank Mayer <mayerf_at_tresys.com>
subject: RE: Security policy analysis
Date: Wed, 10 Oct 2001 17:11:02 -0400
  • This message: [ Message body ]
  • Next message: James Bishop: "Re: Compiling for SuSE 7.2"
  • Previous message: Frank Mayer: "RE: Security policy analysis"
  • In reply to: Frank Mayer: "RE: Security policy analysis"
  • Next in thread: Frank Mayer: "RE: Security policy analysis"


> You can download the tar file at http://www.tresys.com/selinux.html

My apologies, the file that was posted recently was not the correct file. The one at the site now has been update. There really isn't much difference, just some minor changes that removed some (not all!) warnings when -Wall is used.

Frank

--
You have received this message because you are subscribed to the selinux 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.
From: Frank Mayer <mayerf_at_tresys.com>
subject: RE: Security policy analysis
Date: Wed, 10 Oct 2001 16:11:32 -0400
  • This message: [ Message body ]
  • Next message: Frank Mayer: "RE: Security policy analysis"
  • Previous message: Frank Mayer: "RE: Security policy analysis"
  • In reply to: Stephen Smalley: "RE: Security policy analysis"
  • Next in thread: Stephen Smalley: "Re: Security policy analysis"


> So perhaps checkpolicy needs to be revised to generate an intermediate set
> of data structures that are more suitable for policy analysis tools prior
> to generating the final set of data structures for the kernel security
> server?

I think what Steve says is all reasonable and like I mentioned before, it wouldn't be hard to put what we have into checkpolicy even with two different policy DBs. Like I said, we really didn't set out to build a tool, but to analyze policies and so what we have can be viewed as a rapid prototype that we will likely continue to add to.

Frank

--
You have received this message because you are subscribed to the selinux 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.
From: Stephen Smalley <sds_at_tislabs.com>
subject: Re: Security policy analysis
Date: Wed, 10 Oct 2001 15:04:53 -0400 (EDT)
  • This message: [ Message body ]
  • Next message: Stephen Smalley: "RE: Security policy analysis"
  • Previous message: Julien Palardy: "Re: Problems with eth0"
  • In reply to: Jon Crowley: "Re: Security policy analysis"

On Wed, 10 Oct 2001, Jon Crowley wrote:

> Steve also suggested incorporating these functions into checkpolicy.
> With the interactive query front-end, this would become the policy
> analysis tool. However, our take on checkpolicy is that it is intended
> to compile policies and to assist in debugging specific to security
> identifiers. We are thinking it might be cleaner to keep policy
> analysis tools separate from a policy compiling/debugging tool. Though
> perhaps we have the wrong take on checkpolicy. More thoughts on this?

The -d option to the checkpolicy progam can be used to determine how the security server would respond if it were using the policy without actually loading the policy into the kernel security server. Currently, it simply allows you to exercise the security server functions, which are essentially primitive queries on the policy. I don't see why you wouldn't want to add additional support for more complex queries to it. Creating separate tools (with their own code and data structures) will make maintenance harder and increase the likelihood that the policy analysis tools will have a different interpretation of the policy than the security server.

> The problem with building a separate tool is that both tools will share
> some of the same code. Does it makes sense to pull out commonly-used
> code in checkpolicy, specifically the code that reads in the binary and
> text versions of the policy into data structures, and put this code into
> some sort of library? It seems this code may be useful to future
> applications, and it would be easier to maintain and more accessible if
> it was in a library.

This could be done, but it isn't necessary if you merge your tools into checkpolicy.

--
Stephen D. Smalley, NAI Labs
ssmalley@nai.com




--
You have received this message because you are subscribed to the selinux 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.
  • Contemporary messages sorted: [ by date ] [ by thread ] [ by subject ] [ by author ]

This archive was generated by hypermail 2.2.0 on Wed 11 Jun 2008 - 08:10:54 EDT

Information Assurance | Signals & Intelligence        Links | Accessibility | Privacy & Security