China Internet Network Information Center accepted as a Mozilla root CA | Hacker News Reader

China Internet Network Information Center accepted as a Mozilla root CA

lwn.net

68 pointsjeffreyg32 comments

To remove it

Firefox: Tools > Options > Advanced > Encryption > View Certificates > Authorities > find and delete the CNNIC entry

IE: Tools > Internet Options > Content > Publishers > Trusted Root Certification Authorities > find and delete the CNNIC entry

Chrome: Wrench > Options > Under the Hood > Manage Certificates > Trusted Root Certification Authorities > find and delete the CNNIC entry

Note, removing it from either Chrome or IE will remove it from both.

[Edit: added instructions for Chrome and IE]

I followed your deletion instructions on Firefox on OS X, but it keeps coming back like some sort of zombie totalitarian (Hitler?) Even after restarting Firefox, if I go back to the dialog, CNNIC is back.

please file a bug - this should not happen

Ha, this caught me off guard too, but even though it's still listed after restarting Firefox, the permissions have been removed. If you select the cert and click edit, you can see the permission boxes are no longer checked where they were before. See https://bugzilla.mozilla.org/show_bug.cgi?id=173729 for details.

[Edit: At least this is the case on Windows. File a bug report as sandGorgon suggested if that's not the case.]

Mac OS X (affects Safari and presumably other WebKit-based browsers like Chrome): run the "Keychain Access" app in /Applications/Utilities. Select "System Roots" from the upper left pane, then "Certificates" from the lower left. A long list of root CAs should appear in the middle pane, double click "CNNIC ROOT" to edit, expand the "Trust" triangle, change to "Never Trust", close, and authenticate if needed.

Remove it won't do anything, if you visit https://www.enum.cn/ it will come back to your system. You have to disable it and add it to Untrusted.

After just following the steps above, visiting enum.cn shows the "This Connection is Untrusted" dialogue for me on Windows. According to the bug report here: https://bugzilla.mozilla.org/show_bug.cgi?id=173729 I believe the steps above are all you should need to do.

https://bugzilla.mozilla.org/show_bug.cgi?id=542689: "CNNIC is an evil organization. Reproducible: Always"

This is hardly the first SSL certificate authority to be under the thumb of a nation-state actor, but maybe people will listen this time: Don't trust SSL unless you can't avoid it.

Although, how many of those are root CAs in Firefox?

I'm more than a little leery about this, but at least if there is a security breach due to this, it should be traceable, right? I mean, if a CA signs a faulty certificate, their signature is part of the certificate, so it should be traceable. So, without any evidence of wrongdoing, how are they any worse than Verisign? Or any of the cheap SSL certificate providers? It's not like the CNNIC is going out of business anytime soon.

There will be documentary evidence if a nation-state actor uses a bogus SSL certificate, yes. Whether anyone will keep said evidence -- do you keep long-term copies of every SSL certificate you see for www.google.com? -- is a different matter, especially since a smart attacker (which we presume nation-state actors are) is likely to be selective in their targets.

It would be nice if Firefox kept track of certs and notified you of changes (like ssh) regardless of them being signed by a CA or not. Especially if servers made their certs continuous (ie, signing the new one with the old one), in which case it would only warn on discontinuous cert changes.

Yes, this tool should be on by default:

https://addons.mozilla.org/en-US/firefox/addon/6415

Interesting point. But if we aren't going to trust SSL, what should we trust for commerce over the Internet?

Does anyone know how many other browsers have the CNNIC as a root CA?

Given the demographic of Firefox users, I think that this could end up being a huge PR problem for Mozilla.

Edit: After some checking, CNNIC is a root CA in both Windows and Mac, so I don't think that there was much avoiding this for Firefox.

Snow Leopard

So now Google needs to become a SSL CA and at least self-sign certificates for its own domains.

Actually, in paying attention to the certificate chain active in my Gmail sessions, I've noticed that, since last fall, early winter, they may be moving in this direction.

Could someone please explain how CINIC could enact a man in the middle act with this inclusion?

I am vaguely aware of MITM attacks: that someone sends you their public key while pretending to be someone else. And this means the data you send is encrypted in a way that the MITM can see.

However, I'm unsure how CINIC's inclusion in Firefox's root certificates facilitates this. Perhaps I'm not the only one?

On thinking about it a little more, I guess when you visit a site with SSL, and that site subsequently sends you its public key, which in turns allows you to send it encrypted data, Firefox will only accept public keys signed (authorised) by those companies in your root certificate list.

This means if, unknown to you, CINIC impersonates a domain which uses SSL, and you visit that domain and assume your SSL connection will be safe from prying Chinese officials, you're incorrect. Incorrect because Chinese officials could have created that bogus SSL certificate, and it would be accepted by Firefox because Firefox now accept CINIC as a root authority.

Any confirmation, in case I'm spreading inaccuracies, would be appreciated.

Does anyone know if the Chinese gov't could use information gathered by CNNIC for issuing the certificate to decrypt traffic it intercepts encrypted by the public key?

CNNIC would only ever see the public key, and you can't decrypt encrypted data using the public key--you must use the private key to decrypt the data, something CNNIC would not see--so no.

As mentioned, CNNIC's inclusion only allows a Man In The Middle Attack. That is, CNNIC, i.e. the Chinese government, pretending to be a site they're not, and using their status as a Firefox (and other) -authorised root certificate provider to further trick the user into accepting the bogus SSL certificate as originating from the hijacked domain.

OK, thanks for the explanation.

This is indeed the case. The weakness of our current SSL infrastructure is that any CA can sign any site's cert. So the more trusted CAs you have, the wider the attack vector is--all it takes is one rogue CA (or more likely, one CA with weak security) and you can be effectively man-in-the-middled.

Incidentally, it doesn't have to be evil governments doing this.

If your employer uses Watchguard firewalls, they can proxy SSL connections, replace the SSL certificate with one signed by the firewall, and act as a MITM to filter and report the connection contents. If your employer has pushed out certificates by, e.g. active directory and group policies on Windows, then the site will appear padlocked without warnings and you will be none the wiser unless you inspect the certificate. I'm assuming other firewalling products can do similar.

Here is a Chinese blog, hijacking the top 4 email provider SSL on a local machine

http://wuhongsheng.com/it/2009/09/ssl-hijack/

Quite a lot of drama involving China in recent weeks. I wonder what's next? Chinese made laptops contains trojans? Chinese made iPhones contain spy chips? Chinese made clothes stitched with wiretapping chips?

I hate sounding paranoid, but all of these things are possible. Given the tight relationship between Chinese companies and the Chinese government, such shenanigans would be trivially easy.

For anyone looking to do manufacturing in China, this is something to consider.

Has anyone proposed limits on what certs could be issued by root CAs? e.g. What if Firefox only accepted CNNIC certs for .cn names?

One of the problems with CAs and chains of trust is that the decision is binary; if you want a more nuanced view of the trust one should have in a connection, the best you can do is examine the signing chain manually, through the nested dialogs.

This is part of my set of gripes, that the chain is buried. Put it up front. Even "clueless" users will be somewhat likely to notice when it changes, especially if the popular media nudge them in this direction.

Mathematics aside, the basic concepts are not that difficult. (E.g. chain of trust) Let the users know what's behind the padlock icon; they'll pick it up.

(Oh, and stop making https calls from http pages that ask for security information. The paradigm of "look for https in the address bar" and "the closed padlock icon" was a good start. Then everyone went and started breaking it.)

Mozilla is so idealistic about the H.264 video codec but couldn't care less about something like this that actually has serious consequences for end-users.

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