This commit changes the upstream repo location to:
https://gitlab.com/yawning/obfs4.git
Additionally all the non-`main` sub-packages now have an import
comment annotation. As a matter of courtesy, I will continue to
push to both the existing github.com and git.torproject.org repos
for the foreseeable future, though I reserve the right to stop
doing so at any time.
ClientFactories now have a Dial() method instead of a WrapConn()
method, so that it is possible to write something like meek-client
using the obfs4proxy framework.
This breaks the external interface if anyone is using obfs4proxy as
a library, but the new way of doing things is a trivial modification,
to a single routine that shouldn't have been very large to begin with.
Differences from my goptlib branch:
* Instead of exposing a net.Listener, just expose a Handshake() routine
that takes an existing net.Conn. (#14135 is irrelevant to this socks
server.
* There's an extra routine for sending back sensible errors on Dial
failure instead of "General failure".
* The code is slightly cleaner (IMO).
Gotchas:
* If the goptlib pt.Args datatype or external interface changes,
args.go will need to be updated.
Tested with obfs3 and obfs4, including IPv6.
This combines the old signal processing code with the parent monitor,
into a new termination monitor structure, which also now handles keeping
track of outstanding sessions.
The ideal solution here would be to implement #15435, but till then
use one of several kludges:
* Linux - prctl() so that the kernel SIGTERMs on parent exit.
* Other U*ix - Poll the parent process id once a second, and SIGTERM
ourself/exit if it changes. Former is better since all the normal
cleanup if any gets done.
* Windows - Log a warning.
The Go developers decided to move the go.net repository to
golang.org/x/net, and also to transition from hg to git. This wasn't
changed when the go.crypto imports were since the 'proxy' component
doesn't have imports that break, so the old code still works.
While the change here is simple (just update the import location), this
affects packagers as it now expects the updated package. Sorry for the
inconveneince, I blame the Go people, and myself for not just doing
this along with the go.crypto changes.
Client side logs are less spammy than server side in general, so more
messages should be visible at the default logLevel when running as a
client.
Server side logging will be spammy basically no matter what unless
obfs4proxy gets into the (arguably dangerous) business of figuring out
which errors are people being evil vs which ones are transient network
issues, so most logging is suppressed by default, unless the admin
choses to open the floodgates.
The prolog prints the version as soon as logging is enabled, but before
the pluggable transport configuration is done. The epilog is printed as
the code returns from main, as long as either client or server pt
configuration succeded.
By default logging will be done at the "WARN" level. Fatal
initialization errors will always be logged as long as logging
is enabled regardless of logLevel.
Instead of omitting errors entirely when running with the log scrubber,
filter common network errors through elideError() that can scrub the
common net.Error types and remove sensitive information.
The Golang runtime will happily splatter the remote IP address and port
in the error's string representation for network related errors. While
useful for debugging, this is unacceptable from a privacy standpoint.
* Changed obfs4proxy to be more like obfsproxy in terms of design,
including being an easy framework for developing new TCP/IP style
pluggable transports.
* Added support for also acting as an obfs2/obfs3 client or bridge
as a transition measure (and because the code itself is trivial).
* Massively cleaned up the obfs4 and related code to be easier to
read, and more idiomatic Go-like in style.
* To ease deployment, obfs4proxy will now autogenerate the node-id,
curve25519 keypair, and drbg seed if none are specified, and save
them to a JSON file in the pt_state directory (Fixes Tor bug #12605).
To ease delopyment, "-genServerParams has changed".
* "-genServerParams" is now a bool, and will by default generate a
random node-id.
* "-genServerParams -genServerParamsFP=<Base16 blob>" will convert the
supplied bridge fingerprint to a node-id (the old behavior).
Either way of deriving node-id is belived to be secure.
* https://lists.torproject.org/pipermail/tor-dev/2014-May/006929.html
* https://lists.torproject.org/pipermail/tor-dev/2014-June/006936.html
The extra parameter was added because golang's flags library doesn't
support distinguishing between "set but used the default value" and
"not set, so you go the default value".
Instead of using the nonce for the secret box, just use SipHash-2-4 in
OFB mode instead. The IV is generated as part of the KDF. This
simplifies the code a decent amount and also is better on the off
chance that SipHash-2-4 does not avalanche as well as it is currently
assumed.
While here, also decouple the fact that *this implementation* of obfs4
uses a PRNG with 24 bytes of internal state for protocol polymorphism
instead of 32 bytes (that the spec requires).
THIS CHANGE BREAKS WIRE PROTCOL COMPATIBILITY.
Yawning Angel
Yawning Angel
Daniel Martí