NAME

       obfs4proxy - pluggable transport proxy for Tor, implementing obfs4

SYNOPSIS

       obfs4proxy [options]

DESCRIPTION

       obfs4proxy  is  a tool that attempts to circumvent censorship by transforming the Tor traffic between the
       client and the bridge. This way censors, who usually monitor traffic between the client and  the  bridge,
       will see innocent-looking transformed traffic instead of the actual Tor traffic.

       obfs4proxy  implements  the  obfuscation protocols obfs2, obfs3, ScrambleSuit (client only), meek (client
       only) and obfs4.

       obfs4proxy is currently only supported as a managed pluggable transport spawned as a helper  process  via
       the tor daemon.

OPTIONS

       -h, --help
              Display usage information and exit.

       --version
              Display version information and exit.

       --enableLogging
              Enable logging.

       --logLevel=level
              Specify the maximum log severity to log out of "ERROR", "WARN", "INFO", and "DEBUG".

       --unsafeLogging
              Disable  the  IP address scrubber when logging, storing personally identifiable information in the
              logs.

       --obfs4-distBias
              When generating probability distributions for the obfs4 length and  timing  obfuscation,  generate
              biased distributions similar to ScrambleSuit.

ENVIORNMENT

       obfs4proxy  honors  all  of  the  enviornment  variables  as  specified  in  the  Tor Pluggable Transport
       Specification.

FILES

       DataDirectory/pt_state/obfs4proxy.log
           The log file, assuming logging is enabled.

       DataDirectory/pt_state/obfs4_state.json
           The Bridge (server) auto-generated obfs4 bridge parameters file.  This file will not  be  created  if
           the administrator specifies them in the torrc via a ServerTransportOptions directive.

       DataDirectory/pt_state/obfs4_bridgeline.txt
           The  Bridge  (server) obfs4 bridge's client parameters.  This file is created and contains the Bridge
           directive a client should add to their torrc to connect to the running server's obfs4 instance.

CONFORMING TO

       Tor Pluggable Transport Specification

NOTES

       Using the obfs4 protocol requires tor-0.2.5.x or later.

       The obfs2 protocol is included for backwards compatibility purposes only, and should not be used  in  new
       deployments.

EXAMPLE

       To configure tor to be able to use obfs4 bridges (as a client), add obfs4proxy to the torrc like thus:

              # Use obfs4proxy to provide the obfs4 protocol.
              ClientTransportPlugin obfs4 exec /usr/bin/obfs4proxy

       To configure tor to act as an obfs4 bridge (as the server), add obfs4proxy to the torrc like thus:

              #
              # In addition to the standard tor bridge configuration, add:
              #

              # Use obfs4proxy to provide the obfs4 protocol.
              ServerTransportPlugin obfs4 exec /usr/bin/obfs4proxy

SEE ALSO

       tor (1), torrc (5), obfsproxy (1)

                                                   2015-10-29                                      OBFS4PROXY(1)