[Bluez-devel] Service level security for RFCOMM

7 messages, 4 authors, 2004-10-29 · open the first message on its own page

[Bluez-devel] Service level security for RFCOMM

From: Marcel Holtmann <marcel@holtmann.org>
Date: 2004-10-29 04:42:15

Hi Folks,

actually it seems that nobody really cares about service level security
on the RFCOMM layer. Or people are too lazy to send in a patch. However,
I spent some hours with thinking about it and the core stuff of a small
framework for providing authentication and encrypt feedback from HCI to
higher level protocols is finished.

The problem now is to change the RFCOMM state machine to deal with it
and reject connections in the failure case. After looking at the state
machine of RFCOMM, I realized that there are two posibilities when to
trigger the authentication. One is after we receive the PN CMD and the
other after the SABM for the specific channel. The specification says
nothing about that. What are the pros and cons?

And btw, who is really interested in this feature or needs it?

Regards

Marcel




-------------------------------------------------------
This Newsletter Sponsored by: Macrovision 
For reliable Linux application installations, use the industry's leading
setup authoring tool, InstallShield X. Learn more and evaluate 
today. http://clk.atdmt.com/MSI/go/ins0030000001msi/direct/01/
_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel

Re: [Bluez-devel] Service level security for RFCOMM

From: James Cameron <hidden>
Date: 2004-10-29 04:46:27

I'm afraid I don't understand the issues enough to know if I need the
feature.

-- 
James Cameron                         http://quozl.netrek.org/
HP Open Source, Volunteer             http://opensource.hp.com/
PPTP Client Project, Release Engineer http://pptpclient.sourceforge.net/


-------------------------------------------------------
This Newsletter Sponsored by: Macrovision 
For reliable Linux application installations, use the industry's leading
setup authoring tool, InstallShield X. Learn more and evaluate 
today. http://clk.atdmt.com/MSI/go/ins0030000001msi/direct/01/
_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel

Re: [Bluez-devel] Service level security for RFCOMM

From: Marcel Holtmann <marcel@holtmann.org>
Date: 2004-10-29 04:55:58

Hi James,
I'm afraid I don't understand the issues enough to know if I need the
feature.
at the moment you can trigger authentication and encryption for server
sockets on a per PSM basis for the L2CAP. If you use RFCOMM you can't
trigger this and especially not per RFCOMM channel.

Regards

Marcel




-------------------------------------------------------
This Newsletter Sponsored by: Macrovision 
For reliable Linux application installations, use the industry's leading
setup authoring tool, InstallShield X. Learn more and evaluate 
today. http://clk.atdmt.com/MSI/go/ins0030000001msi/direct/01/
_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel

Re: [Bluez-devel] Service level security for RFCOMM

From: Stephen Crane <hidden>
Date: 2004-10-29 09:31:18

On Fri, 2004-10-29 at 05:42, Marcel Holtmann wrote:
actually it seems that nobody really cares about service level security
on the RFCOMM layer. Or people are too lazy to send in a patch. However,
I spent some hours with thinking about it and the core stuff of a small
framework for providing authentication and encrypt feedback from HCI to
higher level protocols is finished.
Perhaps this is because no-one except you and Max understands the RFComm
state-machine? :-)
The problem now is to change the RFCOMM state machine to deal with it
and reject connections in the failure case. After looking at the state
machine of RFCOMM, I realized that there are two posibilities when to
trigger the authentication. One is after we receive the PN CMD and the
other after the SABM for the specific channel. The specification says
nothing about that. What are the pros and cons?

And btw, who is really interested in this feature or needs it?
This is useful (and probably required, I can't remember) for JSR-82.
Especially for people who want to encrypted/authenticated OBEX
connections.

Are you going to do the client-side too?

Steve
-- 
Stephen Crane, Rococo Software Ltd. http://www.rococosoft.com
steve.crane@rococosoft.com +353-1-6601315 (ext 209)

Re: [Bluez-devel] Service level security for RFCOMM

From: Fred Schaettgen <hidden>
Date: 2004-10-29 10:34:49

On Friday 29 October 2004 11:31, Stephen Crane wrote:
On Fri, 2004-10-29 at 05:42, Marcel Holtmann wrote:
quoted
actually it seems that nobody really cares about service level security
on the RFCOMM layer. Or people are too lazy to send in a patch. However,
I spent some hours with thinking about it and the core stuff of a small
framework for providing authentication and encrypt feedback from HCI to
higher level protocols is finished.
..
quoted
And btw, who is really interested in this feature or needs it?
Over here! I'm interested.
I would like to integrate service level security into the meta server of 
kdebluetooth. At the moment you can allow/disallow connections (or show a 
confirmation popup) based on the service/rfcomm channel and on the peer 
device address, but we can't ask for an authenticated link. Being able to use 
service level security would allow us to force authenticated links when using 
any service other than obex push, which should work without having to pair 
devices first.
IIRC I asked you to allow every user to send authentication requests a few 
months ago, so that even programs running without root privileges can trigger 
authentication. But then I didn't post it on the list as you told me, to let 
other people comment on the security implications. The corresonding patch 
changed only a single bit somewhere, but of course this solution is not very 
conveniant. But if you want authentication to appear as a property of a 
single rfcomm connection that's fine too, as long as a regular users are 
allowed to use this feature. Would that be safe?

regards
Fred

-- 
Fred Schaettgen
bluez-devel@schaettgen.de


-------------------------------------------------------
This Newsletter Sponsored by: Macrovision 
For reliable Linux application installations, use the industry's leading
setup authoring tool, InstallShield X. Learn more and evaluate 
today. http://clk.atdmt.com/MSI/go/ins0030000001msi/direct/01/
_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel

Re: [Bluez-devel] Service level security for RFCOMM

From: Marcel Holtmann <marcel@holtmann.org>
Date: 2004-10-29 12:02:46

Hi Steve,
quoted
actually it seems that nobody really cares about service level security
on the RFCOMM layer. Or people are too lazy to send in a patch. However,
I spent some hours with thinking about it and the core stuff of a small
framework for providing authentication and encrypt feedback from HCI to
higher level protocols is finished.
Perhaps this is because no-one except you and Max understands the RFComm
state-machine? :-)
this maybe right, but it is a problem of the RFCOMM protocol itself and
the differences between the 1.0b and 1.1 specification :(
quoted
The problem now is to change the RFCOMM state machine to deal with it
and reject connections in the failure case. After looking at the state
machine of RFCOMM, I realized that there are two posibilities when to
trigger the authentication. One is after we receive the PN CMD and the
other after the SABM for the specific channel. The specification says
nothing about that. What are the pros and cons?

And btw, who is really interested in this feature or needs it?
This is useful (and probably required, I can't remember) for JSR-82.
Especially for people who want to encrypted/authenticated OBEX
connections.
And what to do next? When should the authentication be triggered? What
should happen if the encryption on a link gets deactivated afterwards?
Are you going to do the client-side too?
I have no plan for this, because I don't see the need. What is bad in
using security mode 1 for outgoing and security mode 2 for incoming?

Regards

Marcel




-------------------------------------------------------
This Newsletter Sponsored by: Macrovision 
For reliable Linux application installations, use the industry's leading
setup authoring tool, InstallShield X. Learn more and evaluate 
today. http://clk.atdmt.com/MSI/go/ins0030000001msi/direct/01/
_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel

Re: [Bluez-devel] Service level security for RFCOMM

From: Marcel Holtmann <marcel@holtmann.org>
Date: 2004-10-29 12:10:27

Hi Fred,
quoted
quoted
And btw, who is really interested in this feature or needs it?
Over here! I'm interested.
ok, so lets count. The KDE Bluetooth framework will be the first user :)
I would like to integrate service level security into the meta server of 
kdebluetooth. At the moment you can allow/disallow connections (or show a 
confirmation popup) based on the service/rfcomm channel and on the peer 
device address, but we can't ask for an authenticated link. Being able to use 
service level security would allow us to force authenticated links when using 
any service other than obex push, which should work without having to pair 
devices first.
IIRC I asked you to allow every user to send authentication requests a few 
months ago, so that even programs running without root privileges can trigger 
authentication. But then I didn't post it on the list as you told me, to let 
other people comment on the security implications. The corresonding patch 
changed only a single bit somewhere, but of course this solution is not very 
conveniant. But if you want authentication to appear as a property of a 
single rfcomm connection that's fine too, as long as a regular users are 
allowed to use this feature. Would that be safe?
You should always remember that the authentication is per device and not
per service. You can trigger it on a per service basis, but it is still
common for the complete device.

Regards

Marcel




-------------------------------------------------------
This Newsletter Sponsored by: Macrovision 
For reliable Linux application installations, use the industry's leading
setup authoring tool, InstallShield X. Learn more and evaluate 
today. http://clk.atdmt.com/MSI/go/ins0030000001msi/direct/01/
_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help