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path: root/obfs4.go
AgeCommit message (Collapse)Author
2014-05-21Finish adding godoc comments to all public interfaces.Yawning Angel
2014-05-18Actually keep the delay/threshold in the listener struct.Yawning Angel
This makes it consistent across all incoming connections, for real this time (oops).
2014-05-18Change the server failure close delay/discard length to be consistent.Yawning Angel
It will vary per bridge as it is based off the DRBG, but ever attempt at poking at any given bridge will exhibit consistent behavior.
2014-05-17Change the client connection timeout to 30 sec.Yawning Angel
This is more common than 15 seconds (It's what Firefox uses for the request timeout).
2014-05-16Treat the PrngSeed frame as part of the handshake.Yawning Angel
Clients will now always add 87 bytes of padding to the clientRequest, and Servers will always send the PRNG seed frame unpadded, and bundled with the serverResponse. Why 87 bytes? The amount of data that the server sends is 87. This fixes #5.
2014-05-15Send the DRBG seed as a packetTypePrngSeed post server handshake.Yawning Angel
This fixes #3, and brings the code to be on par with the delopyed versions of ScrambleSuit in terms of features.
2014-05-15Load the drbg-seed from the ServerTransportOptions args.Yawning Angel
This also adds the drgb-seed option to the `-gen` obfs4proxy output.
2014-05-15Change hashDrbg to take a drbgSeed for initialization.Yawning Angel
This paves the way for having servers use the same seed for all incoming connections, across multiple startup/shutdown cycles. As opposed to the current situation where each Obfs4Listener will randomly generate it's seed at creation time. Additionally, use 256 bit seeds (128 bit SipHash-2-4 key + 16 bytes of initial material).
2014-05-15Fix up how Read() errors were processed where appropriate.Yawning Angel
2014-05-14Kill Obfs4Conn.isOk with fire, and replace it with a state var.Yawning Angel
2014-05-14First pass at cleaning up the write code.Yawning Angel
2014-05-14Implement the io.WriterTo interface.Yawning Angel
2014-05-14First pass at cleaning up the read code.Yawning Angel
2014-05-13Add vim modelines to some files (No functional changes).Yawning Angel
2014-05-13Add preliminary support for packet length obfuscation.Yawning Angel
The same algorithm as ScrambleSuit is used, except: * SipHash-2-4 in OFB mode is used to create the distribution. * The system CSPRNG is used when sampling the distribution. This fixes most of #3, all that remains is generating and sending a persistent distribution on the server side to the client.
2014-05-12Fix logging again.Yawning Angel
On second thought instead of using log.Panicf(), panic() and do the logging with recover(). This somewhat centralizes logging in obfs4proxy, which will be easier to change when I invariably decide to do logging differently in the future.
2014-05-12Preliminary support padding, log on panic.Yawning Angel
This adds preliminary support for data padding by adding another layer of encapsulation inside each AEAD frame containing a type and length. For now, data is still sent unpadded, but the infrastructure for supporting it is mostly there. Additionally, use log.Panic[f]() instead of panic through out the code so that some panics are logged.
2014-05-12Remove support for Write deadlines since it wasn't working.Yawning Angel
Write timeouts are obnoxious to handle as the frame encoder state already is updated to cover the entire payload for the Write() call that timed out. In theory it is possible to buffer the pending data, but that causes Write() to voilate the semantics of the interface.
2014-05-12Set a timeout on outgoing handshakes as well.Yawning Angel
2014-05-12Reject clients that do not authenticate quickly enough.Yawning Angel
The current timeout value before the server fails the handshake is 15 s. This may need to be increased for clients over slow links.
2014-05-12Close connections that fail to authenticate after a while.Yawning Angel
Like ScrambleSuit, a random interval between 1x and 5x of additional data from the peer is read and immediately discarded before closing. Additionally, obfs4 will close off invalid connections anywhere between 0 and 60 seconds after it determines that the incoming connection will never complete the handshake successfully.
2014-05-12Move to a unified client/server binary, and fix bugs.Yawning Angel
* The old and the busted: obfs4-[client,server]. * The new hotness: obfs4client. * Add obfs4.ServerHandshake() that servers need to call after a successful return from Accept(). This allows implementations to move the handshake into a goroutine or whatever.
2014-05-09Initial import.Yawning Angel