@kravietz
> group chats can’t be end-to-end encrypted (E2EE), so their contents are readable to at least Telegram operators
Only today this came to me: little is known about it in the rest of the world, but due to sanctions, Russian enterprises and government organizations can't acquire proper security certificates recognised by most widely used browsers.
@kravietz
Thus communication of Russians, most of which have to have this cert installed (they still have to use banks and government-provided services) over non-E2E-encrypted messengers such as Telegram are in theory "transparent" to Russian "law enforcement". I don't know though, if Telegram apps perform any checks and give you any warning if the non-expired certificate gets replaced all of a sudden.
Normally this would be done by the clients using HTTP Public Key Pinning (now obsolete), DANE and CAA, all of which essentially allow checking that the end user certificate has been signed by a specific CA and thus it was not “reissued” by a local security agency. But this of course depends on the client actually doing this check :)
@ackasaber@mathstodon.xyz
Well, Armenian company is unlikely to hold certificates issued to host names used by Telegram, with compromised CA you can do lots of interesting things. For example I hate ajax.googleapis.com so I've made a local mirror of it (you can use Decentraleyes or other such extensions, but why bother if you can have a more fundamental solution), of course I can't legitimately issue a certificate to a host name owned by Google, so it uses my own cert.
@kravietz
@ackasaber@mathstodon.xyz
Normally a browser would detect that and refuse to connect giving you a warning or silently fail if such a host is only a source of scripts images, but as I have my own CA, all my computers have its cert installed, all the certificates I sign with it become trusted and it works 😁
It's just something that I realised today (well, yesterday in fact, before Durov got apprehended). There might be other caveats, I'm not a security researcher, otherwise I'd do a proper writeup.
@kravietz
@robryk
Yandex might be compromised and has security services representatives on board — therefore should no be trusted, but it's not officially a state-owned company — they might be exempt to these sanctions, but they still distribute their own Yandex Browser with said CA baked in. Few others might be using certs that are still valid — those didn't get revoked, they just can't renew them.
@kravietz
@robryk
It was on the news in 2022, e.g. here: https://www.bleepingcomputer.com/news/security/russia-creates-its-own-tls-certificate-authority-to-bypass-sanctions/
In Russia it's a well known fact, maybe not so much outside of it, hence my remark
Check out https://sberbank.ru/ for example, this is one of the biggest banks in Russia and their cert expired only just recently.
@kravietz
@robryk
Yes, that statement was indeed too broad, sorry!
I'm not sure that Yandex is exempt BTW, not versed enough in this topic to tell. They did have to split off the operations in Russia into a separate company and distance the main one from it, maybe they are affected by a different set of sanctions and have problems of their own coming 🤷
@kravietz
@kravietz
To avoid the suspiciously looking warnings they have made their own certification authority and are actively encouraging users to install this CA certificate to their systems. With this cert in the system, MITMing anything gets relatively easy.