On Nov 29, 2018, at 04:53, Warren Kumari <war...@kumari.net> wrote:
> 
> 
> helps mitigate this -- as Tero says above, the user would have to jump 
> through many stupid hoops in order to make themselves vulnerable.

That’s what we came up with when we talked to ekr.

> If think that if the text around "that can be updated out of band" were 
> strengthened (the current wording sounds like being updated out of band is 
> one option, but e.g being updated in-band and "approved" by the user is 
> another), and it were made a bit clearer how the whitelist might be managed 
> I'd be (grudgingly) willing to remove my DISCUSS.

I have no problem making that text stronger / clearer.

> Again, I don't love this, but I think that the mitigations can be made to 
> work, and it *does* solve a real world problem.

Yes, if we want enterprises to deploy DNSSEC, we need this. The 
internal/external views are almost always administrated by a different party, 
so the likelihood of sharing private key is extremely unlikely (plus we would 
be telling them how to run their infrastructure). 

> Can anyone *not* live with this?
> W

I’m fine with the phrasing changes you are requesting.

Paul

> 
>> On Wed, Nov 28, 2018 at 8:12 AM Tero Kivinen <kivi...@iki.fi> wrote:
>> Tony Finch writes:
>> > Joe Abley <jab...@hopcount.ca> wrote:
>> > >
>> > > It seems to me that the intended use-case is access to corporate-like
>> > > network environments where intranet.corporate-like.com might exist on
>> > > the inside but not on the outside.
>> > 
>> > More likely cases like corporate-like.local or corporate-like.int or
>> > like.corp etc. usw. :-(
>> 
>> Yes, this is the more common practice to use. I.e., several companies
>> quite often have (multiple) internal domains they use. Because those
>> are internal domains they cannot get real certificates for them.
>> Because they cannot use real certificates they use self signed
>> certificates, thus users have to click on "trust this web site having
>> invalid certificate yes/no". The idea is that with TLSA we could get
>> some kind of security for those internal sites.
>> 
>> More competent companies might also run their own CA and use that to
>> sign internal web sites, but unfortunately those more competent
>> companies usually then also have heavy IT processes that requires all
>> kind of complicated stuff to get things be signed by corporate CA, and
>> then developers setting up intranet / chat system / testing setup etc
>> revert to self signed certificates, because it is easy. On the other
>> hand getting DNS names added to the internal DNS is usually something
>> that happens often, and is not too hard to do, getting TLSA record
>> along with the name should also be quite easy.
>> 
>> Now when browsers start to make it harder and harder to allow access
>> to self signed certificates, users are seeing more and more problems
>> with that.
>> 
>> > Private DNSSEC trust anchors should be distributed in the same way
>> > that you would distribute corporate X.509 trust anchors.
>> 
>> This is exactly what is proposed by the draft, execpt that it is split
>> in two parts, i.e., the names for which TAs can be given are
>> distributed in same way as X.509 trust anchors, the actual contents
>> for the TA for that whitelisted name is distributed inside IKE.
>> 
>> The draft requires the whitelist to pre-configured before starting up
>> the VPN connection. It also do require implementations to ignore all
>> those settings unless user have explictly configured split-tunnel on
>> for that connection.
>> 
>> I.e., in the example the VPNs-R-Us would not be able to set those
>> configuration settings, nor would it be able to provide dialog asking
>> that.
>> 
>> VPN-R-Us would require provide instructions how to configure your VPN
>> client to do that, i.e., it would need to ask users to do following:
>> 
>>   - In your IPsec VPN configuration dialog click "Add" to add new VPN. 
>>   - Type in VPNs-R-Us for name, and IP of f00::BA5 as IP-address.
>>   - Click advanced
>>   - In Advanced settings to go the enterprise VPN tab
>>   - In there click the Enable Split-tunnel setup check box.
>>   - Answer YES to question verifying that you really want to configure
>>     this manually, and do not want to use the managment profile
>>     provided by the enterprise (normally enterprise VPN setups are
>>     managed automatically by profiles provided by the company, normal
>>     users usually do not even have option to change anything).
>>   - After that click "Add items to DNSSEC whitelist".
>>   - Type in "farfetch.com", and click OK.
>>   - (vpn client would probably forbid him adding .com to list as or if
>>     it is added it would be ignored), so VPN-R-Us is smart and asks
>>     following:
>>   - Type in "paypal.com" and click OK.
>>   - Click OK to few times and get the VPN configuration setup.
>>   - Then fire up the VPN client.
>> 
>> More likely VPN-R-Us would say if you do not want to do that, just
>> download this easy binary exe that will do all that configuration for
>> you (and some others they do not mention).
>> 
>> I.e., that whitelist needs to be modified out of band. Usually it is
>> done by the management system taking care of the enterprise profiles,
>> i.e., the same program that installs X.509 roots for the company CA,
>> and mandates that virus checkers are up to date before allowing
>> connection to the corporate network, and which also configures the VPN
>> connection too.
>> 
>> If you are running that kind of programs you have already given all
>> control to whoever provided you that program (VPN-R-Us, or the
>> enterprise).
>> 
>> In enterprise case, you usually do not have option not to, as those
>> softwares come pre-installed and you cannot uninstall or not to use
>> them. On the other hand do not use your work laptop to go to paypal,
>> if you do not trust your company...
>> 
>> And yes, the enterprise (or VPN-R-Us) management.exe could also
>> install those TAs directly for the global system use without any
>> problems. This would not be problem for the VPN-R-Us (they would be
>> happy to have fake TA in your system even when you are not using their
>> VPN), but enterprise might not want to have its TA there when you are
>> not connected to its network, just to limit the exposure, and they
>> might want to update the TA contens, even when the whitelisted domain
>> name stays same.
>> 
>> I.e., if the TAs cannot be transmitted and agreed to be taken in use
>> (after comparing them to whitelist) inside the IKE, then enterprises
>> will most likely just install them by the management system for
>> general use (or not use DNSSEC). I think that would weaken security
>> more than what is proposed in this draft.
>> -- 
>> kivi...@iki.fi
> 
> 
> -- 
> I don't think the execution is relevant when it was obviously a bad idea in 
> the first place.
> This is like putting rabid weasels in your pants, and later expressing regret 
> at having chosen those particular rabid weasels and that pair of pants.
>    ---maf
> _______________________________________________
> DNSOP mailing list
> DNSOP@ietf.org
> https://www.ietf.org/mailman/listinfo/dnsop
_______________________________________________
DNSOP mailing list
DNSOP@ietf.org
https://www.ietf.org/mailman/listinfo/dnsop

Reply via email to