[tor-relays] Multiple ServerTransportListenAddr OBFS2|3|4 Configuration

[Gary C. New]

All:

I noticed that the obfs2, obfs3, and obfs4 transport names seem to be hardcoded into tor.

I have been able to configure the torrc to register each of the transports for multiple ServerTransportListenAddr:

# cat torrc
ORPort xxx.xxx.xxx.xxx:443 NoListen
ORPort 192.168.0.31:9001 NoAdvertise
SocksPort 9050
SocksPort 192.168.0.31:9050
ControlPort 9051
HTTPTunnelPort 9080
HTTPTunnelPort 192.168.0.31:9080
ExtORPort 192.168.0.31:auto
BridgeRelay 1
BridgeDistribution moat
ServerTransportPlugin obfs2 exec /opt/bin/obfs4proxy -enableLogging
ServerTransportListenAddr obfs2 192.168.0.31:3102
ServerTransportOptions obfs2 iat-mode=2
ServerTransportPlugin obfs3 exec /opt/bin/obfs4proxy -enableLogging
ServerTransportListenAddr obfs3 192.168.0.31:3103
ServerTransportOptions obfs3 iat-mode=2
ServerTransportPlugin obfs4 exec /opt/bin/obfs4proxy -enableLogging
ServerTransportListenAddr obfs4 192.168.0.31:3104
ServerTransportOptions obfs4 iat-mode=2
DirCache 1
ExitRelay 0

# grep -i obfs ./torlog 
2022/12/14 00:39:07 [NOTICE]: obfs4proxy-0.0.14 - launched
Dec 13 17:41:48.000 [notice] Registered server transport 'obfs2' at '192.168.0.31:3102'
Dec 13 17:41:48.000 [notice] Registered server transport 'obfs3' at '192.168.0.31:3103'
Dec 13 17:41:48.000 [notice] Registered server transport 'obfs4' at '192.168.0.31:3104'

# netstat -anp | grep obfs4proxy
tcp        0      0 192.168.0.31:3102       0.0.0.0:*               LISTEN      30185/obfs4proxy
tcp        0      0 192.168.0.31:3103       0.0.0.0:*               LISTEN      30185/obfs4proxy
tcp        0      0 192.168.0.31:3104       0.0.0.0:*               LISTEN      30185/obfs4proxy

My question is whether the respective obfs2|3|4 transport names force the corresponding protocol?

If so... Are there any ServerTransportOptions that can force the obfs4 protocol on the legacy obfs2|3 transports?

Also... It wasn't clear in the manual whether obfs4proxy -enableLogging takes an optional path/file?

I appreciate any knowledge on the subjects.

Respectfully,


Gary