[tbb-bugs] #15690 [Applications/Tor Browser]: Document how other extensions should ask to isolate their streams

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#15690: Document how other extensions should ask to isolate their streams
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 Reporter:  arma                      |          Owner:  tbb-team
     Type:  enhancement               |         Status:  new
 Priority:  Medium                    |      Milestone:
Component:  Applications/Tor Browser  |        Version:
 Severity:  Normal                    |     Resolution:
 Keywords:                            |  Actual Points:
Parent ID:                            |         Points:
 Reviewer:                            |        Sponsor:
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Comment (by sysrqb):

 Last night I noticed if the browser is closed for more than 24 hours, then
 at startup both torbutton and https-everywhere check for updates at the
 same time - and they use the same catch-all circuit.

 {{{
 [04-02 23:05:41] Torbutton INFO: Checking version with socks port: 9150
 [04-02 23:05:41] Torbutton INFO: tor SOCKS:
 https://www.torproject.org/projects/torbrowser/RecommendedTBBVersions via
                        --unknown--:ccf852ed7d4b2ab5dee2e90ae4950456
 [04-02 23:05:42] Torbutton INFO: controlPort >> 650 STREAM 22 REMAP 4
 138.201.14.197:443 SOURCE=EXIT
 [04-02 23:05:42] Torbutton INFO: controlPort >> 650 STREAM 22 SUCCEEDED 4
 138.201.14.197:443
 [04-02 23:05:42] Torbutton WARN: no SOCKS credentials found for current
 document.
 [04-02 23:05:42] Torbutton INFO: tor SOCKS: https://www.https-
 rulesets.org/v1//rulesets-signature.1554143726.sha256 via
                        --unknown--:ccf852ed7d4b2ab5dee2e90ae4950456
 [04-02 23:05:42] Torbutton INFO: tor SOCKS: https://www.https-
 rulesets.org/v1//default.rulesets.1554143726.gz via
                        --unknown--:ccf852ed7d4b2ab5dee2e90ae4950456
 [04-02 23:05:42] Torbutton INFO: tor SOCKS:
 https://2019.www.torproject.org/projects/torbrowser/RecommendedTBBVersions
 via
                        --unknown--:ccf852ed7d4b2ab5dee2e90ae4950456
 }}}

 My feeling is this is a bug, and these requests should be FPI-respecting
 (meaning each extension should be considered as its own first-party in
 this context). It seems like there should be some mechanism for linking a
 connection (when it reaches the proxy service) with the extension where it
 originated. Unforunately, it seems like this doesn't currently exist(?).

 In spite of my feeling, I'm not sure about the harm imposed by not
 isolating these requests. It potentially leaks to an exit node there is
 (with high probability) a Tor Browser user who started the browser after
 24+ hours of it not running. This could mean they didn't upgrade to the
 latest version yet, and this could expose them to an attack vector (if a
 severe vulnerability in Tor Browser was recently patched). But I'm not
 sure leaking this information is different than many other traffic
 patterns (such as connecting to aus1.tp.o and downloading megabytes of
 data at a time when there wasn't a recent release). It would be nice if we
 can quantify the risk associated with this.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/15690#comment:5>
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