Telegram Desktop has received an initial implementation of a new WEB proxy that hides messenger connections inside ordinary HTTPS and WebSocket traffic. For network providers the user appears to be simply visiting a website, while MTProxy continues to function under the hood.
Changes were discovered in the client source code. Developers added more than 3,000 lines, a separate WEB-proxy transport, domain settings, and interface controls including “Open browser” and “Waiting for browser.”
The scheme operates as follows: Telegram Desktop launches an embedded web page and establishes a secure WebSocket connection to a domain that externally resembles an ordinary site. Several MTProxy connections are combined into one stream and transmitted through this channel. On the server side an intermediate node splits the stream back into separate connections and passes them to a conventional MTProxy instance. The relay does not need to decrypt the correspondence content and functions only as a transport sorter.
This approach is expected to complicate traffic blocking by providers that rely on DPI or simple domain blacklists, because the observable traffic matches typical web browsing patterns.
