Re: LE Kernel (bluetooth-le-2.6) and LE Security Manager

[Brian Gix <bgix@codeaurora.org>]

Hi Vinicius,

I am sorry that it has taken so long to test the snapshot that you
placed on gitorious, but I have now done so.

On Fri, 2010-12-03 at 19:05 -0300, Vinicius Costa Gomes wrote:
> Hi Brian,
> 
> On 11:11 Fri 03 Dec, Brian Gix wrote:
> > 
> > Hi Claudio, Johan & All,
> > 
> > Is this LE capable kernel that Ville is working on, the development stream
> > for the LE Security Manager?  And if so, is it in a partial fleshed out
> > state?
> 
> There is a simple implementation of SMP here[1] on my "devel" branch. I am 
> cleaning it up for sending it for review.
> 
> If you want to help, have any comments or just want to tell us what you are
> working on, please drop by #bluez on freenode, or send an email.

I have been able to verify that the Just Works negotiation of the Short
Term Key does work against an independent implementation of the LE
Security Manager, as long as I have requested no MITM protection.  I
have the following comments:

1. You currently reject security if I *do* request MITM protection.
This should not be done.  The correct functionality should be to
continue the negotiation.  Even though I requested MITM, it will be
clear to both sides that JUST_WORKS methodology has been used, and so
when the Keys are generated and exchanged, both sides will indicate in
their Key Database that they are no-MITM keys. If I then actually
*needed* MITM protection, then whatever functionality requiring that
level of security will fail with an insufficient security error code.
However, security should *never* be rejected unless there is a
fundamental incompatibility such as no level of security actually
supported.  This is the only functionality that I found to be actually
incorrect.

2. Currently, you are not exchanging any permanent keys, which I am sure
you are aware.  This makes it impossible to test much else, such as
command signing, or security requests that use the generated keys.

If you have a later version of SM that could be uploaded to your devel
branch on gitorious, I would be more than happy (and in fact would love
to be able) to test that for you as well.

This is the git configuration I used for testing, which only has your SM
up to the end of last December, and is so about a month old:

remote.origin.url=git://gitorious.org/bluetooth-next/bluetooth-next.git
branch.devel.remote=origin
branch.devel.merge=refs/heads/devel


Thanks for doing the SM,

-- 
Brian Gix
bgix@codeaurora.org
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum