“Signal is being blocked in Venezuela and Russia. The app is a popular choice for encrypted messaging and people trying to avoid government censorship, and the blocks appear to be part of a crackdown on internal dissent in both countries…”
Yeah the main thing is that the ports and addresses can change and it’s nbd. From a firewall perspective, it’s impossible to block them all. Especially when the clients are doing mundane https requests. Even if the server goes down or partial connectivity, the channel can still be used.
But this seems easy to automatically block, no? If a client is querying an unknown domain check for some Matrix related data in /.well-known/ and add it to the block list if there is. And since the servers are publicly advertising the port used you just need to periodically check the list of known matrix domains you are creating in the first step.
Russia is already doing DPI and blocking ESNI so that seems easy. A more widespread usage of ECH would help everyone, as is Signal advocating, but that’s not the case yet.
