Massive cleanup/code reorg.

 * 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).

1 files changed, 0 insertions, 212 deletions

diff --git a/packet.go b/packet.go
deleted file mode 100644
index 58a5877..0000000
--- a/packet.go
+++ /dev/null
@@ -1,212 +0,0 @@
-/*
- * Copyright (c) 2014, Yawning Angel <yawning at torproject dot org>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- *  * Redistributions of source code must retain the above copyright notice,
- *    this list of conditions and the following disclaimer.
- *
- *  * Redistributions in binary form must reproduce the above copyright notice,
- *    this list of conditions and the following disclaimer in the documentation
- *    and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-
-package obfs4
-
-import (
-	"crypto/sha256"
-	"encoding/binary"
-	"fmt"
-	"io"
-	"syscall"
-
-	"git.torproject.org/pluggable-transports/obfs4.git/drbg"
-	"git.torproject.org/pluggable-transports/obfs4.git/framing"
-)
-
-const (
-	packetOverhead          = 2 + 1
-	maxPacketPayloadLength  = framing.MaximumFramePayloadLength - packetOverhead
-	maxPacketPaddingLength  = maxPacketPayloadLength
-	seedPacketPayloadLength = SeedLength
-
-	consumeReadSize = framing.MaximumSegmentLength * 16
-)
-
-const (
-	packetTypePayload = iota
-	packetTypePrngSeed
-)
-
-// InvalidPacketLengthError is the error returned when decodePacket detects a
-// invalid packet length/
-type InvalidPacketLengthError int
-
-func (e InvalidPacketLengthError) Error() string {
-	return fmt.Sprintf("packet: Invalid packet length: %d", int(e))
-}
-
-// InvalidPayloadLengthError is the error returned when decodePacket rejects the
-// payload length.
-type InvalidPayloadLengthError int
-
-func (e InvalidPayloadLengthError) Error() string {
-	return fmt.Sprintf("packet: Invalid payload length: %d", int(e))
-}
-
-var zeroPadBytes [maxPacketPaddingLength]byte
-
-func (c *Obfs4Conn) producePacket(w io.Writer, pktType uint8, data []byte, padLen uint16) (err error) {
-	var pkt [framing.MaximumFramePayloadLength]byte
-
-	if !c.CanReadWrite() {
-		return syscall.EINVAL
-	}
-
-	if len(data)+int(padLen) > maxPacketPayloadLength {
-		panic(fmt.Sprintf("BUG: makePacket() len(data) + padLen > maxPacketPayloadLength: %d + %d > %d",
-			len(data), padLen, maxPacketPayloadLength))
-	}
-
-	defer func() {
-		if err != nil {
-			c.setBroken()
-		}
-	}()
-
-	// Packets are:
-	//   uint8_t type      packetTypePayload (0x00)
-	//   uint16_t length   Length of the payload (Big Endian).
-	//   uint8_t[] payload Data payload.
-	//   uint8_t[] padding Padding.
-	pkt[0] = pktType
-	binary.BigEndian.PutUint16(pkt[1:], uint16(len(data)))
-	if len(data) > 0 {
-		copy(pkt[3:], data[:])
-	}
-	copy(pkt[3+len(data):], zeroPadBytes[:padLen])
-
-	pktLen := packetOverhead + len(data) + int(padLen)
-
-	// Encode the packet in an AEAD frame.
-	var frame [framing.MaximumSegmentLength]byte
-	frameLen := 0
-	frameLen, err = c.encoder.Encode(frame[:], pkt[:pktLen])
-	if err != nil {
-		// All encoder errors are fatal.
-		return
-	}
-	var wrLen int
-	wrLen, err = w.Write(frame[:frameLen])
-	if err != nil {
-		return
-	} else if wrLen < frameLen {
-		err = io.ErrShortWrite
-		return
-	}
-
-	return
-}
-
-func (c *Obfs4Conn) consumeFramedPackets(w io.Writer) (n int, err error) {
-	if !c.CanReadWrite() {
-		return n, syscall.EINVAL
-	}
-
-	var buf [consumeReadSize]byte
-	rdLen, rdErr := c.conn.Read(buf[:])
-	c.receiveBuffer.Write(buf[:rdLen])
-	var decoded [framing.MaximumFramePayloadLength]byte
-	for c.receiveBuffer.Len() > 0 {
-		// Decrypt an AEAD frame.
-		decLen := 0
-		decLen, err = c.decoder.Decode(decoded[:], &c.receiveBuffer)
-		if err == framing.ErrAgain {
-			break
-		} else if err != nil {
-			break
-		} else if decLen < packetOverhead {
-			err = InvalidPacketLengthError(decLen)
-			break
-		}
-
-		// Decode the packet.
-		pkt := decoded[0:decLen]
-		pktType := pkt[0]
-		payloadLen := binary.BigEndian.Uint16(pkt[1:])
-		if int(payloadLen) > len(pkt)-packetOverhead {
-			err = InvalidPayloadLengthError(int(payloadLen))
-			break
-		}
-		payload := pkt[3 : 3+payloadLen]
-
-		switch pktType {
-		case packetTypePayload:
-			if payloadLen > 0 {
-				if w != nil {
-					// c.WriteTo() skips buffering in c.receiveDecodedBuffer
-					var wrLen int
-					wrLen, err = w.Write(payload)
-					n += wrLen
-					if err != nil {
-						break
-					} else if wrLen < int(payloadLen) {
-						err = io.ErrShortWrite
-						break
-					}
-				} else {
-					// c.Read() stashes decoded payload in receiveDecodedBuffer
-					c.receiveDecodedBuffer.Write(payload)
-					n += int(payloadLen)
-				}
-			}
-		case packetTypePrngSeed:
-			// Only regenerate the distribution if we are the client.
-			if len(payload) == seedPacketPayloadLength && !c.isServer {
-				var seed *drbg.Seed
-				seed, err = drbg.SeedFromBytes(payload)
-				if err != nil {
-					break
-				}
-				c.lenProbDist.reset(seed)
-				if c.iatProbDist != nil {
-					iatSeedSrc := sha256.Sum256(seed.Bytes()[:])
-					iatSeed, err := drbg.SeedFromBytes(iatSeedSrc[:])
-					if err != nil {
-						break
-					}
-					c.iatProbDist.reset(iatSeed)
-				}
-			}
-		default:
-			// Ignore unrecognised packet types.
-		}
-	}
-
-	// Read errors and non-framing.ErrAgain errors are all fatal.
-	if (err != nil && err != framing.ErrAgain) || rdErr != nil {
-		// Propagate read errors correctly.
-		if err == nil && rdErr != nil {
-			err = rdErr
-		}
-		c.setBroken()
-	}
-
-	return
-}
-
-/* vim :set ts=4 sw=4 sts=4 noet : */