obfs4proxy(1)

1OBFS4PROXY(1)               General Commands Manual              OBFS4PROXY(1)
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NAME

6       obfs4proxy - pluggable transport proxy for Tor, implementing obfs4
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SYNOPSIS

9       obfs4proxy [options]
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DESCRIPTION

12       obfs4proxy  is  a tool that attempts to circumvent censorship by trans‐
13       forming the Tor traffic between the client and  the  bridge.  This  way
14       censors, who usually monitor traffic between the client and the bridge,
15       will see innocent-looking transformed traffic instead of the actual Tor
16       traffic.
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18       obfs4proxy implements the obfuscation protocols obfs2, obfs3, Scramble‐
19       Suit (client only), meek (client only) and obfs4.
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21       obfs4proxy is currently only supported as a managed pluggable transport
22       spawned as a helper process via the tor daemon.
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OPTIONS

25       -h, --help
26              Display usage information and exit.
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28       --version
29              Display version information and exit.
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31       --enableLogging
32              Enable logging.
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34       --logLevel=level
35              Specify  the maximum log severity to log out of "ERROR", "WARN",
36              "INFO", and "DEBUG".
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38       --unsafeLogging
39              Disable the IP address scrubber when logging, storing personally
40              identifiable information in the logs.
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42       --obfs4-distBias
43              When  generating  probability distributions for the obfs4 length
44              and timing obfuscation, generate biased distributions similar to
45              ScrambleSuit.
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ENVIORNMENT

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

52       DataDirectory/pt_state/obfs4proxy.log
53           The log file, assuming logging is enabled.
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55       DataDirectory/pt_state/obfs4_state.json
56           The Bridge (server) auto-generated obfs4  bridge  parameters  file.
57           This  file  will not be created if the administrator specifies them
58           in the torrc via a ServerTransportOptions directive.
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60       DataDirectory/pt_state/obfs4_bridgeline.txt
61           The Bridge (server) obfs4 bridge's client parameters.  This file is
62           created  and  contains  the Bridge directive a client should add to
63           their torrc to connect to the running server's obfs4 instance.
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CONFORMING TO

66       Tor Pluggable Transport Specification
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NOTES

69       Using the obfs4 protocol requires tor-0.2.5.x or later.
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71       The obfs2 protocol is included  for  backwards  compatibility  purposes
72       only, and should not be used in new deployments.
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EXAMPLE

75       To  configure  tor  to  be able to use obfs4 bridges (as a client), add
76       obfs4proxy to the torrc like thus:
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78              # Use obfs4proxy to provide the obfs4 protocol.
79              ClientTransportPlugin obfs4 exec /usr/bin/obfs4proxy
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81       To configure tor to act  as  an  obfs4  bridge  (as  the  server),  add
82       obfs4proxy to the torrc like thus:
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84              #
85              # In addition to the standard tor bridge configuration, add:
86              #
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88              # Use obfs4proxy to provide the obfs4 protocol.
89              ServerTransportPlugin obfs4 exec /usr/bin/obfs4proxy
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