OBFS4PROXY(1) General Commands Manual OBFS4PROXY(1) NNAAMMEE obfs4proxy - pluggable transport proxy for Tor, implementing obfs4 SSYYNNOOPPSSIISS oobbffss44pprrooxxyy [_o_p_t_i_o_n_s] DDEESSCCRRIIPPTTIIOONN 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 ttoorr daemon. OOPPTTIIOONNSS --hh, ----hheellpp Display usage information and exit. ----vveerrssiioonn Display version information and exit. ----eennaabblleeLLooggggiinngg Enable logging. ----llooggLLeevveell=_l_e_v_e_l Specify the maximum log severity to log out of "EERRRROORR", "WWAARRNN", "IINNFFOO", and "DDEEBBUUGG". ----uunnssaaffeeLLooggggiinngg Disable the IP address scrubber when logging, storing personally identifiable information in the logs. ----oobbffss44--ddiissttBBiiaass When generating probability distributions for the obfs4 length and timing obfuscation, generate biased distributions similar to ScrambleSuit. EENNVVIIOORRNNMMEENNTT obfs4proxy honors all of the enviornment variables as specified in the Tor Pluggable Transport Specification. FFIILLEESS _D_a_t_a_D_i_r_e_c_t_o_r_y//pptt__ssttaattee//oobbffss44pprrooxxyy..lloogg The log file, assuming logging is enabled. _D_a_t_a_D_i_r_e_c_t_o_r_y//pptt__ssttaattee//oobbffss44__ssttaattee..jjssoonn The Bridge (server) auto-generated obfs4 bridge parameters file. This file will not be created if the administrator specifies them in the ttoorrrrcc via a SSeerrvveerrTTrraannssppoorrttOOppttiioonnss directive. _D_a_t_a_D_i_r_e_c_t_o_r_y//pptt__ssttaattee//oobbffss44__bbrriiddggeelliinnee..ttxxtt The Bridge (server) obfs4 bridge's client parameters. This file is created and contains the BBrriiddggee directive a client should add to their ttoorrrrcc to connect to the running server's obfs4 instance. CCOONNFFOORRMMIINNGG TTOO Tor Pluggable Transport Specification NNOOTTEESS 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. EEXXAAMMPPLLEE To configure tor to be able to use obfs4 bridges (as a client), add obfs4proxy to the ttoorrrrcc 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 ttoorrrrcc like thus: # # In addition to the standard tor bridge configuration, add: # # Use obfs4proxy to provide the obfs4 protocol. ServerTransportPlugin obfs4 exec /usr/bin/obfs4proxy SSEEEE AALLSSOO ttoorr ((11)),, ttoorrrrcc ((55)),, oobbffsspprrooxxyy ((11)) 2015-10-29 OBFS4PROXY(1)