migrated from:
https://github.com/Whonix/Whonix/issues/316

There is an attack bridges can perform on first-time users. This involves feeding old consensus data (which can be up to a week old).

We could use anondate to parse Tor consensus from two sources:

• downloaded by Tor
• (multiple times) downloaded by python-stem

Treat the bridge's consensus as untrusted and not factor it in.

sdwdate / sdwdate-gui has already a good infrastructure.

• To inform the user about the state of network time synchronization. A progress indicator, telling them to wait until it's done before using the internet. One more sanity check that adds up to the wait is negligible. Also this is very similar to the sanity check planned in T151.
• sdwdate prerequisite would wait until this check could even be run - A standalone bridgesanitycheck cannot run before Tor starts serving anyhow.

Give it its own indicator. It shouldn't wait for sdwdate.

Rely on Tor stem in all cases.

Let's implement sdwdate Tor Consensus Time Sanity Check (T151) first, see how that goes and then get back to this one.