Re: NetworkManager time sync

[Daniel Drake]

On 5 July 2010 21:44, C. Scott Ananian <cscott(a)laptop.org&gt; wrote:
>  Maybe someone's got a copy of build 653 lying around and they can
> run
>  rpm -q for us. 
While we have your attention on this topic...
Do you not think that this is a security issue? In that a thief could
put a laptop on a network with rigged DNS and have control over the
time/date on the laptop?

It does seem like that we have (unintentionally?) dropped this
functionality from recent builds, but it seems like we could even call
it intentional: this functionality weakens the security system, and in
recent builds we now have a secure way of updating the time: the
olpc-update-query OAT client now synchronizes the time from the OAT
server, and this communication is covered by the usual key-based
security mechanisms.

Daniel

NetworkManager time sync

[Martin Langhoff]

On Mon, Jul 5, 2010 at 11:52 PM, Daniel Drake <dsd(a)laptop.org&gt; wrote:
>  While we have your attention on this topic...
>  Do you not think that this is a security issue? In that a thief could
>  put a laptop on a network with rigged DNS and have control over the
>  time/date on the laptop? 
We *really* have to get OFW clock checks working -- then this
disappears as an issue. I really want to be able to use ntp (at least
ntpdate on NM successful connect). The OATS clock sync is very rough
-- on purpose.

Apparently the ntp protocol supports some server-signing of the
messages -- we could use an OATS key for that. But it looks rickety.

cheers,



m
-- 
 martin.langhoff(a)gmail.com
 martin(a)laptop.org -- School Server Architect
 - ask interesting questions
 - don't get distracted with shiny stuff  - working code first
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NetworkManager time sync

[Bernie Innocenti]

El Wed, 07-07-2010 a las 12:20 -0400, Martin Langhoff escribió:

>  Apparently the ntp protocol supports some server-signing of the
>  messages -- we could use an OATS key for that. But it looks rickety. 
Authenticated NTP sounds like a good solution. NTP4 supports public key
cryptography based on SSL certificates.

We don't have to reuse the OATS keys for authentication and we also
don't have to use the same server for OATS and NTP. Any trusted public
ntp server should be fine. Maybe also the school servers.

So, how about setting up a public ntp server and publishing the keys?
I've already been running two public servers for one year or so:

  time1.sugarlabs.org
  time2.sugarlabs.org

These are registered with ntp.org. I could generate keys and use them
with py builds. Anyone else would be welcome to use our servers, of
course.

Alternatively, we could simply distribute ntp keys to our xs with
puppet. However, this would stop working once the kids leave the school
system.

In case we opt for using public ntp servers with no authentication, I've
also registered olpc.ntp.org (as recommended by someone in this thread).

-- 
   // Bernie Innocenti - http://codewiz.org/
 \X/  Sugar Labs       - http://sugarlabs.org/