Date: Mon, 01 Jun 2015 19:20:32 +0000 From: nusenu nusenu@openmailbox.org
Hi,
by comparing different methodologies of "parsing" myfamily data I stumbled upon differences between onionoo and compass.
After manual review I assume there is a bug in onionoo (or onionoo has a different opinion on what families actually are)
Example:
According to onionoo, torpidsDEevanzo [1] is part of a family with 38 members.
It lists torpidsFRonline [2] as one of its members, that implies that torpidsFRonline lists torpidsDEevanzo as one of its members as well, but torpidsDEevanzo does _not_ list torpidsFRonline (according to onionoo data).
grep 'fingerprint":"0C77421C890D16B6D201283A2' details.json|grep 5510FC1736B16D46D3F2DDA5011995C478D42594 (no result)
Is this a bug?
thanks
[1] https://atlas.torproject.org/#details/5510FC1736B16D46D3F2DDA5011995C478D425...
[2] https://atlas.torproject.org/#details/0C77421C890D16B6D201283A2244F43DF5BC89...
No, it's a feature :-)
MyFamily requires bidirectional declarations to be effective. This prevents a malicious relay nominating significant portions of the Tor network as its family, in order to direct traffic to another malicious relay. (And/or slowing down the network and attempting to cause a DoS.)
In this case:
torpids relays have inconsistent MyFamily configurations. OnionOO appears to correctly implement the bidirectional MyFamily logic, and remove inconsistent one-way MyFamily declarations. Compass appears to believe each relay's MyFamily claims, without checking the other relay. This appears to be a fairly harmless bug in Compass, as Compass itself is not used for path selection.
teor
teor2345 at gmail dot com pgp 0xABFED1AC https://gist.github.com/teor2345/d033b8ce0a99adbc89c5
teor at blah dot im OTR D5BE4EC2 255D7585 F3874930 DB130265 7C9EBBC7
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512
teor:
MyFamily requires bidirectional declarations to be effective.
I'm aware of that fact ;)
In this case: OnionOO appears to correctly implement the bidirectional MyFamily logic
Apparently it doesn't.
Since onionoo says there is a bidirectional "connection" (family) between 5510FC1736B16D46D3F2DDA5011995C478D42594 => 0C77421C890D16B6D201283A2244F43DF5BC89DD
but there is none.. (as explained in my last email)
Compass does *not* say that there is a bidirectional connection between those relays.. onionoo says there is one even though I can't see it, do you see it?
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nusenu -
teor