Opened 10 months ago

Closed 3 months ago

#27723 closed task (fixed)

Obfs4 stopped working 16 Sept 18

Reported by: mwolfe Owned by: dcf
Priority: Medium Milestone:
Component: Circumvention/Censorship analysis Version:
Severity: Normal Keywords: censorship block ae obfs4 meek
Cc: anadahz Actual Points:
Parent ID: Points:
Reviewer: Sponsor:

Description

I was using obfs4 on 15 Sept 18, but shortly after midnight, it stopped working, and I'm using azure. I assume that's the only thing that works when obfs4 fails.

Child Tickets

Attachments (1)

torlog19122018.doc (30.0 KB) - added by mwolfe 7 months ago.
log trying to connnect without and with bridge

Download all attachments as: .zip

Change History (19)

comment:1 Changed 10 months ago by mwolfe

I forgot to mention I am in the UAE.

comment:2 Changed 10 months ago by Dbryrtfbcbhgf

  1. After the connection fails click on configure, or just cancel the connection and then click configure.
  2. Make sure tor is centered in my country is checked
  3. Check request a bridge from Torproject.org and click on request the bridge
  4. Fill in the captcha and click the return “enter” button on your keyboard.
  5. It should now connect

Here’s an explanation on how to manually connect to a bridge.

https://tb-manual.torproject.org/en-US/bridges.html

comment:3 Changed 10 months ago by cypherpunks3

I assume that's the only thing that works when obfs4 fails.

Try snowflake ;)

comment:4 Changed 10 months ago by mwolfe

After 1 day, whatever was blocking obfs4 disappeared (meek is very slow, but better than no access at all; but I tried obfs4 again, and late today, it worked). This happened before, when obfs4 could not access any websites for a few days, and then it could again. Back then, there were 2 meeks, and I had better luck with the other one than with Azure.

comment:5 Changed 10 months ago by mwolfe

I went back to the stable Tor (I was having problems with the unstable), and no snowflake appears on stable Tor. Unless I installed it wrong. I tried to go back to stable, and it was difficult, since the unstable puts stuff in that breaks the stable version on a Mac (both stable and unstable share a directory with stuff that doens't get overwritten with a normal install). Is there a way to do a clean install of Tor?

comment:6 Changed 10 months ago by Felixix

After 1 day, whatever was blocking obfs4 disappeared (meek is very slow, but better than no access at all; but I tried obfs4 again, and late today, it worked).

Is this about build-in obfs4 bridges? There was a 4 hours maintainance of two bridges with offtime and a possible overload of the remaining ones.

This happened before, when obfs4 could not access any websites for a few days, and then it could again.

If this was around end of July we might have had a gap because of the change to the new Bridge Authority Serge.
Both would be technical cases and no blocking events. If this does not meet your observation disregard the said.

comment:7 Changed 10 months ago by traumschule

Component: - Select a componentObfuscation/Obfsproxy
Owner: set to asn

comment:8 Changed 10 months ago by dcf

Component: Obfuscation/ObfsproxyObfuscation/Censorship analysis
Keywords: censorship block ae obfs4 meek added
Owner: changed from asn to dcf
Type: enhancementtask

comment:9 Changed 9 months ago by arma

I would assume the issue here is that the person's specific obfs4 bridges stopped working, e.g. they went down, not that the obfs4 protocol started getting blocked.

One corollary is that we need to do a better job of teaching people how each pluggable transport design works, e.g. in some of them you need to get individual bridges, and those bridges need to stay up and also not discovered by the censor. (I don't know of any cases where UAE blocked specific bridges by IP address, but in China they definitely do.)

comment:10 Changed 9 months ago by traumschule

Where should that teaching happen: in TB, the FAQ, wiki, tb-manual or on the download page even?

comment:11 in reply to:  5 ; Changed 7 months ago by anadahz

Replying to mwolfe:

I went back to the stable Tor (I was having problems with the unstable), and no snowflake appears on stable Tor. Unless I installed it wrong. I tried to go back to stable, and it was difficult, since the unstable puts stuff in that breaks the stable version on a Mac (both stable and unstable share a directory with stuff that doens't get overwritten with a normal install). Is there a way to do a clean install of Tor?

Do you know if Tor vanilla (no usage of bridges) is blocked in UAE?

comment:12 Changed 7 months ago by anadahz

Cc: anadahz added

comment:13 in reply to:  11 ; Changed 7 months ago by mwolfe

Replying to anadahz:

Replying to mwolfe:
Do you know if Tor vanilla (no usage of bridges) is blocked in UAE?

As of today, Tor is not blocked. Sometimes, I have been unable to connect without bridges. Today, I can. They seem to block and unblock. Sometimes I use obfs4, sometimes that's blocked so I switch to obfs3 and that works. Sometimes nothing works except Azure. But today, Tor is not being censored. (Skype is censored, so I wish Tor would let me Skype.)

comment:14 in reply to:  13 ; Changed 7 months ago by anadahz

Replying to mwolfe:

Replying to anadahz:

Replying to mwolfe:
Do you know if Tor vanilla (no usage of bridges) is blocked in UAE?

As of today, Tor is not blocked. Sometimes, I have been unable to connect without bridges. Today, I can. They seem to block and unblock. Sometimes I use obfs4, sometimes that's blocked so I switch to obfs3 and that works. Sometimes nothing works except Azure. But today, Tor is not being censored. (Skype is censored, so I wish Tor would let me Skype.)

It will be really interesting to find out if there is any pattern on how often/which date/time interval they use to block.

Changed 7 months ago by mwolfe

Attachment: torlog19122018.doc added

log trying to connnect without and with bridge

comment:15 in reply to:  14 ; Changed 7 months ago by mwolfe

Replying to anadahz:

Replying to mwolfe:

Replying to anadahz:

Replying to mwolfe:
Do you know if Tor vanilla (no usage of bridges) is blocked in UAE?

As of today, 18 Dec 2018, Tor is not blocked.

It will be really interesting to find out if there is any pattern on how often/which date/time interval they use to block.

Today, 19 Dec 2018, Tor is blocked. I have attached a copy of the log showing Tor trying to connect, failing until I turned on obfs4, then connecting. I have no idea when Tor is blocked and unblocked, but at least I can connect just by clicking obfs4. For now.

comment:16 in reply to:  15 Changed 7 months ago by mwolfe

Replying to mwolfe:

Replying to anadahz:

Replying to mwolfe:

Replying to anadahz:

Replying to mwolfe:
Do you know if Tor vanilla (no usage of bridges) is blocked in UAE?

As of today, 18 Dec 2018, Tor is not blocked.

It will be really interesting to find out if there is any pattern on how often/which date/time interval they use to block.

Today, 19 Dec 2018, Tor is blocked. I have attached a copy of the log showing Tor trying to connect, failing until I turned on obfs4, then connecting. I have no idea when Tor is blocked and unblocked, but at least I can connect just by clicking obfs4. For now.

Today, 21 Dec 2018, Tor is unblocked, I can connect without a bridge. I have no idea when or why Tor is sometimes blocked (but obfs4 usually works) and other times is unblocked.

comment:17 Changed 3 months ago by dcf

I added the two blocking events to the Metrics Timeline:
https://trac.torproject.org/projects/tor/wiki/doc/MetricsTimeline?action=diff&version=315
Other than that, I don't know what more we can do on this. Thank you for continuing to report conditions in the UAE, mwolfe.

comment:18 Changed 3 months ago by dcf

Resolution: fixed
Status: newclosed
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