commit 1648ca676aa2ae251b6d751fb826470eadc699f3 Author: George Kadianakis <desnacked@riseup.net> Date: Thu Mar 14 12:26:32 2013 -0400 Edit the xxx-pluggable-transports-through-proxy.txt proposal a bit --- .../xxx-pluggable-transports-through-proxy.txt | 73 ++++++++++---------- 1 files changed, 36 insertions(+), 37 deletions(-) diff --git a/proposals/ideas/xxx-pluggable-transports-through-proxy.txt b/proposals/ideas/xxx-pluggable-transports-through-proxy.txt index 221c0d1..3fc7754 100644 --- a/proposals/ideas/xxx-pluggable-transports-through-proxy.txt +++ b/proposals/ideas/xxx-pluggable-transports-through-proxy.txt @@ -6,14 +6,14 @@ 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". + 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 normal (SOCKS/HTTP) 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 @@ -21,7 +21,7 @@ Trivia 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 +Acknowledgments 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 @@ -29,51 +29,50 @@ Acknowledgements Motivation - After looking at some options we decided to go for this solution solution + After looking at some options we decided to go for this 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 Tor is configured to use both a pluggable transport proxy and a + normal proxy it should delegate the proxying to the pluggable + transport proxy. - 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. + This can be achieved by specifying the address and port of the normal + proxy to the pluggable transport proxy using environment variables: + When both a normal proxy and the ClientTransportPlugin directives + are set in the torrc, Tor should put the address of the normal proxy + in an environment variable and start the pluggable transport + proxy. When the pluggable transport proxy starts, it should read the + address of the normal proxy and route all its traffic through it. + After connecting to the normal proxy, the pluggable transport proxy + notifies Tor whether it managed to connect or not. - The environment variables can also contain the credentials for accessing - the proxy. + The environment variables also contain the authentication + 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: + When Tor detects a normal 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> + <proxy_type>://[<user_name>][:<password>][@]<ip>:<port> ex. socks5://tor:test1234@198.51.100.1:8000 socks4a://198.51.100.2:8001 + Acceptable values for <proxy_type> are: 'socks5', 'socks4a' and 'http'. + If no <password> can be specified (e.g. in 'socks4a'), it is left out. + + If the pluggable transport proxy detects that the TOR_PT_PROXY + environment variable is set, it attempts connecting to it. On + success it writes to stdout: "PROXY true". + On failure it writes: "PROXY-ERROR <errormessage>". - 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 a PROXY line or it reads a PROXY-ERROR line + from its stdout and it is configured to use both a normal proxy and + a pluggable transport it should kill the transport proxy. - 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.