Opened 3 months ago

Last modified 9 days ago

#30870 needs_information defect

Default obfs4 bridges are all offline

Reported by: phw Owned by: n8fr8
Priority: Medium Milestone:
Component: Applications/Orbot Version:
Severity: Normal Keywords: tbb-bridges
Cc: Actual Points:
Parent ID: Points:
Reviewer: Sponsor:

Description

All obfs4 bridges in the following two files are offline as of June 12 2019:

  • orbotservice/src/main/res/raw-fa/bridges.txt
  • orbotservice/src/main/res/raw/bridges.txt

I hear that in the long run, Orbot will use tor-android-service, which includes our up-to-date default bridges, but in the short run we should make sure that these bridges are kept in sync with our default bridges.

Child Tickets

Change History (6)

comment:1 Changed 3 months ago by phw

Status: newneeds_review

I have a fix in my GitHub branch fix/30870 .

Edit: I deleted my patch because it's outdated.

Last edited 10 days ago by phw (previous) (diff)

comment:2 Changed 3 months ago by phw

FWIW, I updated and force-pushed my patch because Linus' obfs4 bridges have been removed in the meanwhile.

comment:3 in reply to:  description Changed 10 days ago by arma

Replying to phw:

but in the short run we should make sure that these bridges are kept in sync with our default bridges

Btw, the original idea here was that Orbot intentionally shipped with a different list of default bridges than Tor Browser, because then whichever one attracted more censor attention wouldn't automatically undermine the other.

Though if Orbot isn't maintaining its chosen bridges, that original idea isn't so smart anymore. :)

comment:4 Changed 10 days ago by phw

Status: needs_reviewneeds_information

Setting this to "needs_information" to see what orbot's strategy here is. I will remove the fix I pushed earlier because it's already outdated again. For what it's worth, our list of default bridges is available here: https://trac.torproject.org/projects/tor/wiki/doc/TorBrowser/DefaultBridges

comment:5 Changed 10 days ago by n8fr8

Why is it so hard to keep good obfs4 bridges online? It is frustrating that we have to keep changing these.

I am not even talking about "unblocked in China", I just mean reliably running. What is the expected life time of an obfs4 bridge?

We don't run our own bridges, but it may be time for us to do that.

comment:6 in reply to:  5 Changed 9 days ago by phw

Replying to n8fr8:

Why is it so hard to keep good obfs4 bridges online? It is frustrating that we have to keep changing these.


The last few disappeared because 1) one operator's server contract expired, 2) another operator wanted to reduce his maintenance burden, and 3) several default bridges disappeared without anyone noticing, so we removed them.

I am not even talking about "unblocked in China", I just mean reliably running. What is the expected life time of an obfs4 bridge?


The longer, the better. We are in touch with a bunch of research groups who are interested in setting up a default bridge (e.g., #31164). Hopefully, this will result in several new and long-lived bridges.

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