commit 5b2b6b591ee436b9ff1e65247f4f32fe145c2c78 Author: Jacob Appelbaum jacob@appelbaum.net Date: Wed Feb 29 13:40:14 2012 -0400

add xxx-pluggable-transports-through-proxy.txt by hellais --- .../xxx-pluggable-transports-through-proxy.txt | 79 ++++++++++++++++++++ 1 files changed, 79 insertions(+), 0 deletions(-)

diff --git a/proposals/ideas/xxx-pluggable-transports-through-proxy.txt b/proposals/ideas/xxx-pluggable-transports-through-proxy.txt new file mode 100644 index 0000000..221c0d1 --- /dev/null +++ b/proposals/ideas/xxx-pluggable-transports-through-proxy.txt @@ -0,0 +1,79 @@ +Filename: xxx-pluggable-transports-through-proxy.txt +Title: Pluggable Transport through SOCKS proxy +Author: Arturo Filastò +Created: 28 February 2012 +Status: Draft + +Overview + + Tor introduced Pluggable Transports in proposal 180 Pluggable Transports + for circumvention. + + The problem is that Tor currently cannot use a Pluggable Transport proxy + and a SOCKS proxy at the same time. This has been noticed by users in + #5195, where Tor would be failing saying "Unacceptable option value: + You have configured more than one proxy type". + + +Trivia + + This comes from a discussion that came up with Nick and I promised + to write a proposal for it if I wanted to hear what he had to say. + Nick spoke and I am writing this proposal. + +Acknowledgements + + Most of the credit goes to Nick Mathewson for the main idea and + the rest of it goes to George Kadianakis for helping me out in writing + it. + +Motivation + + After looking at some options we decided to go for this solution solution + since it guarantees backwards compatibility and is not particularly + costly to implement. + +Design overview + + When Tor is configured to use both a Pluggable Transport proxy and SOCKS + proxy it should delegate the proxying to the pluggable transport proxy. + + This can be achieved by setting the environment variables for the SOCKS + proxy to that specified inside of the torrc. + + When the pluggable transport proxy starts it will first read the environment + variables and if it detects that it should be using a SOCKS proxy make + all it's traffic go through it. Once the pluggable transport proxy has successfully + established a connection to the SOCKS proxy it should notify Tor of it's + success or failure. + When both the SOCKS and the PluggableTransport directives are set Tor + should set the environemnt variable start the pluggabletransport proxy and wait + for it to report back on the SOCKS proxy status. If the pluggable transport + reports back a failure or it does not report back at all (maybe because + it is an outdated version), Tor should notify the user of the failure + and exit with an error. + + + The environment variables can also contain the credentials for accessing + the proxy. + +Specifications: Tor Pluggable Transport communication + + When Tor detects a SOCKS proxy directive and a Pluggable Transport + proxy directive it sets the environment variable: + + "TOR_PT_PROXY" -- This is the address of the proxy to be used by + the pluggable transport proxy. It is in the format: + <proxy_type>://<user_name?>:<password?>@<ip>:<port> + ex. socks5://tor:test1234@198.51.100.1:8000 + socks4a://198.51.100.2:8001 + + + If the pluggable transport proxy detects that the TOR_PT_PROXY environment + variable is set it attempts connecting to it. On successs it will + write to stdout (as specified in 180-pluggable-transport.txt) + PROXY true. On failure it should write PROXY-ERROR <errormessage>. + + If Tor does not read any PROXY line or it reads a PROXY-ERROR line + and it is configured to use both SOCKS and PluggableTransport it should + exit with error.