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MITM on HTTPS traffic in Kazakhstan

bugzilla.mozilla.org

41–50 of 471 posts

Re: MITM on HTTPS traffic in Kazakhstan

#41

Earlier quoted context omitted.

> What Kazakhstan has done is create their own root certificate and asked people who live there to install it in their browsers. Is this voluntary? If I bring a device into the country without this certificate (or if the local removes it from their machine) do things go back to normal?

Going back to normal, i.e the browser saying that the presented certificate is invalid, yes. But you will not be able to browse anything over a HTTPS connection. (Or do other stuff over PKI based TLS, i.e downloading software updates etc.)

Shoot, I hadn't even considered software updates. If this is installed at the system level, they could MITM any software update mechanism that doesn't use cert pinning, couldn't they? Woof.

Re: MITM on HTTPS traffic in Kazakhstan

#42
post #20

Could someone explain to me what this means and/or why it's bad?

When you connect to a website via HTTPS, your browser downloads the certificate from that website and validates it by checking that the website's certificate was cryptographically signed by an entity that the browser trusts. If the certificate is valid, then you can assume that your data will only be decrypt-able by the website owner, so the connection is secure. Your browser will display a happy green banner showing…

What prevents us from having to trust Verisign (or its employees) or a government warrant, etc. to not do the same?

Can we leverage signed DNS records to add another layer of control needed? Do we also need encrypted DNS where we can choose who to trust? Are we stuck with the CA trust model?

Re: MITM on HTTPS traffic in Kazakhstan

#43
post #20

Earlier quoted context omitted.

When you connect to a website via HTTPS, your browser downloads the certificate from that website and validates it by checking that the website's certificate was cryptographically signed by an entity that the browser trusts. If the certificate is valid, then you can assume that your data will only be decrypt-able by the website owner, so the connection is secure. Your browser will display a happy green banner showing…

> What Kazakhstan has done is create their own root certificate and asked people who live there to install it in their browsers. Is this voluntary? If I bring a device into the country without this certificate (or if the local removes it from their machine) do things go back to normal?

If you don't have the special root certificate installed, the browser will refuse to connect because the certificate being presented is invalid (it's the government spying certificate, which you don't trust, not Facebook's certificate, which you do trust).

Re: MITM on HTTPS traffic in Kazakhstan

#44

Warning: what follows is completely baseless speculation, and let's concede that right off the bat. Who's to say that this isn't happening in the US as well? The US has invested billions of dollars in dragnet surveillance that is allegedly useless for anything other than metadata in the context of HTTPS. Is it out of the question to ask whether our secret courts could issue gag orders and claim that national security…

If the NSA was using their own certificates to MITM all HTTPS traffic it would be easily noticed by security researchers. Its not like they obtain the private keys of every US company. They'd have to make their own replacement certain for every site they wish to intercept. That could easily be noticed by security professionals and targeted companies by monitoring.

Re: MITM on HTTPS traffic in Kazakhstan

#45

Does such a certificate compromise non-browser traffic as well? Like SSH tunnels, mobile apps, Telegram etc.

SSH doesn't depend on certificate authorities, it's up to you to manage your own keys, each end point also has a uniquely generated signature which avoids MITM after first time auth (including by taking over domains).

This is a HTTPS only issue and fundamentally it's the same problem as control over domains (ease of manipulation through centralisation).

Re: MITM on HTTPS traffic in Kazakhstan

#46

I have custom root certs for internal dev sites for my company. That's fine, but I'd like to add the root with a caveat that I control saying "I trust this root for *.mycompany.com,mycompany.org", but that I know means they wouldn't be able to proxy "mybank.com". I don't think Firefox or Chrome can do that can it?

There is a Name Constraints extension in X.509[1] that does exactly that, but to my knowledge no browser implements it. [1] https://tools.ietf.org/html/rfc5280#section-4.2.1.10

and that would have to be baked into the CA certificate, not specified when the CA is trusted. I dont want my browser to ask the CA what it's allowed to do, i want to tell it what it's allowed to do

Re: MITM on HTTPS traffic in Kazakhstan

#47
post #33
post #21

I find the social aspect of this interesting. Us "smart tech people" have been pushing https everywhere for a few years now as a way of protecting internet privacy "for the masses". And now the government found a very simple non-technical workaround. Send a message to everyone requiring a government root CA with an easy install, or their internet won't work. Now "us techies" have to find a new technical solution to a…

We need new measures to not allow these certificates to be installed unless they're verified, or at least the OS shows a massive giant warning "DO NOT DO THIS unless you accept this cert gives $identity access to all your data". Seems a very solvable problem.

Verified by whom? I certainly want my browser and OS to retain my possibility of installing certificates all day long.

Trivial technological solutions will not stop the state actor from retaliating against those not following their policy either.

Re: MITM on HTTPS traffic in Kazakhstan

#48
post #31

Earlier quoted context omitted.

Theoretical quedtion: would a VPN in Kazakhstan allow you to test this?

No, as the certificates are user installed. The Bugzilla and other threads are about distrusting that user certificate.

VPN with endpoint on affected ISP + Installing the cert (which is linked in the issue on Bugzilla) should be the same as just using the affect ISP directly, shouldn't it?

Re: MITM on HTTPS traffic in Kazakhstan

#49
post #42
post #20

Earlier quoted context omitted.

When you connect to a website via HTTPS, your browser downloads the certificate from that website and validates it by checking that the website's certificate was cryptographically signed by an entity that the browser trusts. If the certificate is valid, then you can assume that your data will only be decrypt-able by the website owner, so the connection is secure. Your browser will display a happy green banner showing…

What prevents us from having to trust Verisign (or its employees) or a government warrant, etc. to not do the same? Can we leverage signed DNS records to add another layer of control needed? Do we also need encrypted DNS where we can choose who to trust? Are we stuck with the CA trust model?

You're right, trust is a major issue with any PKI. You can find hundreds of research papers and blog posts and probably even a few whole books on the topic, I'm sure :)

Re: MITM on HTTPS traffic in Kazakhstan

#50

Warning: what follows is completely baseless speculation, and let's concede that right off the bat. Who's to say that this isn't happening in the US as well? The US has invested billions of dollars in dragnet surveillance that is allegedly useless for anything other than metadata in the context of HTTPS. Is it out of the question to ask whether our secret courts could issue gag orders and claim that national security…

If the NSA was using their own certificates to MITM all HTTPS traffic it would be easily noticed by security researchers. Its not like they obtain the private keys of every US company. They'd have to make their own replacement certain for every site they wish to intercept. That could easily be noticed by security professionals and targeted companies by monitoring.

What about just for the Alexa 100?
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