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Diffstat (limited to 'doc/spec/proposals/148-uniform-client-end-reason.txt')
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diff --git a/doc/spec/proposals/148-uniform-client-end-reason.txt b/doc/spec/proposals/148-uniform-client-end-reason.txt deleted file mode 100644 index cec81253ea..0000000000 --- a/doc/spec/proposals/148-uniform-client-end-reason.txt +++ /dev/null @@ -1,59 +0,0 @@ -Filename: 148-uniform-client-end-reason.txt -Title: Stream end reasons from the client side should be uniform -Version: $Revision$ -Last-Modified: $Date$ -Author: Roger Dingledine -Created: 2-Jul-2008 -Status: Closed -Implemented-In: 0.2.1.9-alpha - -Overview - - When a stream closes before it's finished, the end relay cell that's - sent includes an "end stream reason" to tell the other end why it - closed. It's useful for the exit relay to send a reason to the client, - so the client can choose a different circuit, inform the user, etc. But - there's no reason to include it from the client to the exit relay, - and in some cases it can even harm anonymity. - - We should pick a single reason for the client-to-exit-relay direction - and always just send that. - -Motivation - - Back when I first deployed the Tor network, it was useful to have - the Tor relays learn why a stream closed, so I could debug both ends - of the stream at once. Now that streams have worked for many years, - there's no need to continue telling the exit relay whether the client - gave up on a stream because of "timeout" or "misc" or what. - - Then in Tor 0.2.0.28-rc, I fixed this bug: - - Fix a bug where, when we were choosing the 'end stream reason' to - put in our relay end cell that we send to the exit relay, Tor - clients on Windows were sometimes sending the wrong 'reason'. The - anonymity problem is that exit relays may be able to guess whether - the client is running Windows, thus helping partition the anonymity - set. Down the road we should stop sending reasons to exit relays, - or otherwise prevent future versions of this bug. - - It turned out that non-Windows clients were choosing their reason - correctly, whereas Windows clients were potentially looking at errno - wrong and so always choosing 'misc'. - - I fixed that particular bug, but I think we should prevent future - versions of the bug too. - - (We already fixed it so *circuit* end reasons don't get sent from - the client to the exit relay. But we appear to be have skipped over - stream end reasons thus far.) - -Design: - - One option would be to no longer include any 'reason' field in end - relay cells. But that would introduce a partitioning attack ("users - running the old version" vs "users running the new version"). - - Instead I suggest that clients all switch to sending the "misc" reason, - like most of the Windows clients currently do and like the non-Windows - clients already do sometimes. - |