Tor bridge scanning
We need to scan the reachability of Tor Bridges from parts of the world. This is geared at detecting what bridges are working correctly and which are censored from where.
This is what the ooni-probe test BridgeT does.
The main question this tool wants to answer is: "Amongst this set of bridges which ones are working from where?"
the sub-question is: "The not working ones are not working because they are censored?"
The data that should come out of BridgeT are:
- Timestamp of the scan
- IP address of the scanner
- IP address of the scanned bridge
- Status: working | not working | censored
- Some debug information on what went wrong
The debug information should be in a first stage the output of Tors log for loglevel notice, info or debug. In future this may be expanded to include some other information (what? packet captures?).
This will be deployed in a first stage on Planet labs servers. In future it will be one of the default ooni-probe tests and will run from wherever ooni-probe is running from.
Another worth considering question is how BridgeT learns about the bridges to test. If we want this to scale well we should figure out a mechanism for making BridgeT learn about new bridges to scan.
In the first phase the list is just a static text file.
Somebody should test out the current BridgeT code to make sure that it is working correctly.