Re: Checking for services to be restarted on a default Debian installation

2014-09-07 Thread Eirik Schwenke
On 7 September 2014 15:30:22 CEST, David Prévot taf...@debian.org wrote:
Le 07/09/2014 02:07, Paul Wise a écrit :
 On Tue, Sep 2, 2014 at 2:48 AM, Thijs Kinkhorst wrote:

 My questions to this list:
 - Do people agree that this would be something that's good to have
in a
 default installation? Are there drawbacks?

Not restarting by default the DM seems to be nice thing to have.
How does it work if the upgrade run in the background? Will all needed
service be restarted without asking? (If so, the gdm3 restart issue may
be a blocker).


As a long time user and system administrator I agree that notification and 
*optional* automatic restarts have a place in the default install (with 
appropriate notes in the changelog for Jessie, obviously!).

For a server, there should be some easy to adjust setting, choosing between 
automatic restarts and simply notifying of restart of x, y, z needed due to 
upgrade b and c (with comment from changelog: is this a security issue?).

Do we have a framework for persistent gui notifications on the desktop? Eg: 
next time someone in the sudo group logs in; show request for system 
restart/kexec and/or subsystem restarts? I know Ubuntu has a default software 
center thing for that -- is there something like it in tasksel-desktop? (I 
generally run a lean xmonad-only setup - a notification in my xmobar would be 
nice, though)

On a server I'm generally happy with an email to root - but do we have 
somewhere we could put notifications? Eg: service names in 
/var/run/restart-pending or something along those lines?

The idea being that apt/dpgk/checkrestart could append package names here, and 
a do-pending-restarts-script could remove them (probably better just to run 
checkrestarts again and verify start time/loaded libraries vs latest installed 
version and update the needs-restart queue as appropriate?).

The more I think about, the better I like the idea of having a text-file as a 
job queue of pending restarts, and a script that checks running processes for 
open dlls that updates such a file (can be put in cron for generatoøing gui 
alerts w fallback to console alerts on systems w/o xorg).

Alerting for restarts amounts to checking for the presence of such a file and 
re-running the checkrestart script to regenerate it, or remove it if all needed 
restarts are done (seperate file for kernel, or use service name kexec? For 
servers it might nice to notify on updated inintrd/grub.cfg as there is no 
*guarantee* the system will boot after such changes -- until they've been 
verified by a successful reboot).

Thoughts? Is this overboard for getting into Jessie?

Best regards, 

Eirik

-- 
Via phone - please excuse quoting and spelling


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Re: concrete steps for improving apt downloading security and privacy

2014-07-10 Thread Eirik Schwenke
On 10 July 2014 18:07:59 CEST, Elmar Stellnberger estel...@gmail.com wrote:

In order to prevent unsuspecting users from downloading a compromised
version of Debian I wanna propose the following:

* promote the inclusion of Debian-public-keys in any free live CD sold
with magazines and books:

I believe there is a copy of the key on the install cds? I don't see how 
getting a cd and a key from the same source really increases the trust level?

A better approach might be having the magazines publish their own 
key/fingerprint in every issue and then manually (with a face-to-face meeting) 
have the magazines sign the Debian key (s) and upload the signatures to the 
keyerver network.

(...)

There is no sense in verifying a download with gpg unless you have
fetched the public keys from a secure source.

You should be very careful when using the term secure source of public keys. 
A key is considered secure of it is trusted; it is considered trusted if it is 
signed by someone (many!) you trust: eg yourself or someone you know (and have 
the trusted key of).

Don't turn public crytography into secret key cryptography! Web-of-trust is a 
state of the art way to manage trust and key distribution!

(...)

* https mirrors could in addition provide some additional security
including
   - more privacy about the selection of packages you have downloaded

I think now, and for the forseeable future, many (most) mirrors are likely to 
be run by goverment sponsored/friendly institutions - and at any rate are 
likely to maintain traffic/access logs (in some jurisdictions this is mandated 
by law). Plain https does not protect (much) against a nation state level 
adversary.

Onion transports and local mirroring seem a better option if the goal is 
privacy. Even then, knowing that someone runs Debian and dates and filesizes of 
security updates might be enough to guess at installed packages/open 
vulnerabilities in a system?

  - no deliberate delaying of new security updates (+ dnssec of course)

See above re:traffic analysis. I do think cron-apt could use some love/a better 
alternative?

- secure download of individual packages on a non Debian machine for
transport to an offline Debian machine

We already have this?

- an additional security mechanism if some private keys should ever be
stolen temporarily

Keys cannot be stolen temporary;  they are trusted or untrusted (revoked).

Speaking off - we could perhaps have a better ui for adding/revoking keys? With 
better support for web of trust and key severs?

the current certificate authorization process is heavily compromised !!

Yes, I would also like to see a Debian CA set up - just because it would make 
sense to anchor trust of other ssl - infrastructure in the gpg-signed iso/dpkg 
distribution. As it is (as the ca certs are distributed the same as the rest of 
Debian) it only offers a secondary attack surface. You could be getting rogue 
ca certs the same way you could ne getting a backdoored libssl/kernel/etc.

The one benefit of the CA system is that cacerts are distributed by other os 
vendors as well. I think that is where a lot of this type of discussion is 
comming from. People would rather go to a website that windos xp saus is safe, 
in order to get Debian - rather than make an effort to verify the trust of 
Debian's various gpg keys.

Arguably we could do better with encouraging more user groups to do keysigning 
parties and education in order to make trust in gpg more easily viable for new 
users. 


As for pinning trust: one (not very rigorous) approach is to simpky assume 
you're not currently compromised (that is a necessary assumtion if you want to 
use gpg anyway) and sign the current Debian keys with your own gpg key (plaese 
do not upload such leap-of-faith signatures to the keyservers, though).

When you've done that, either:

1) you've signed a compromised key: at least if you discover that later, you 
know how far back you were (at least) compromised. 

2) You've trrusted a trustworthy key; you're safe until the next roll-over.

We could perhaps do a better job saying some of the above on the wiki/homepage? 
It's unfortunately unreasonable to assume most users are familiar with gpg and 
trust networks.

Comments?


-eirik

Ps: please trim and quote appropriately when posting to the list.



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