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)