Initial import.

1 files changed, 225 insertions, 0 deletions

diff --git a/obfs4-server/obfs4-server.go b/obfs4-server/obfs4-server.go
new file mode 100644
index 0000000..aac2351
--- /dev/null
+++ b/obfs4-server/obfs4-server.go
@@ -0,0 +1,225 @@
+/*
+ * 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.
+ *
+ * This file is based off goptlib's dummy-server.go file.
+ */
+
+// obfs4 pluggable transport server. Works only as a managed proxy.
+//
+// Usage (in torrc):
+// 	BridgeRelay 1
+// 	ORPort 9001
+// 	ExtORPort 6669
+// 	ServerTransportPlugin obfs4 exec obfs4-server
+//  ServerTransportOptions obfs4 private-key=<Base64 Bridge private key> node-id=<Base64 Node ID>
+//
+// Becuase the pluggable transport requires arguments, using obfs4-server
+// requires tor 0.2.5.x.
+package main
+
+import (
+	"encoding/hex"
+	"flag"
+	"fmt"
+	"io"
+	"net"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+
+	"github.com/yawning/obfs4"
+	"github.com/yawning/obfs4/ntor"
+)
+
+import "git.torproject.org/pluggable-transports/goptlib.git"
+
+var ptInfo pt.ServerInfo
+
+// When a connection handler starts, +1 is written to this channel; when it
+// ends, -1 is written.
+var handlerChan = make(chan int)
+
+func copyLoop(a, b net.Conn) {
+	var wg sync.WaitGroup
+	wg.Add(2)
+
+	go func() {
+		io.Copy(b, a)
+		wg.Done()
+	}()
+	go func() {
+		io.Copy(a, b)
+		wg.Done()
+	}()
+
+	wg.Wait()
+}
+
+func handler(conn net.Conn) error {
+	defer conn.Close()
+
+	handlerChan <- 1
+	defer func() {
+		handlerChan <- -1
+	}()
+
+	or, err := pt.DialOr(&ptInfo, conn.RemoteAddr().String(), "obfs4")
+	if err != nil {
+		return err
+	}
+	defer or.Close()
+
+	copyLoop(conn, or)
+
+	return nil
+}
+
+func acceptLoop(ln net.Listener) error {
+	defer ln.Close()
+	for {
+		conn, err := ln.Accept()
+		if err != nil {
+			if e, ok := err.(net.Error); ok && !e.Temporary() {
+				return err
+			}
+			continue
+		}
+		go handler(conn)
+	}
+}
+
+func generateParams(id string) {
+	rawID, err := hex.DecodeString(id)
+	if err != nil {
+		fmt.Println("Failed to hex decode id:", err)
+		return
+	}
+
+	parsedID, err := ntor.NewNodeID(rawID)
+	if err != nil {
+		fmt.Println("Failed to parse id:", err)
+		return
+	}
+
+	fmt.Println("Generated node_id:", parsedID.Base64())
+
+	keypair, err := ntor.NewKeypair(false)
+	if err != nil {
+		fmt.Println("Failed to generate keypair:", err)
+		return
+	}
+
+	fmt.Println("Generated private-key:", keypair.Private().Base64())
+	fmt.Println("Generated public-key:", keypair.Public().Base64())
+}
+
+func main() {
+	var err error
+
+	// Some command line args.
+	genParams := flag.String("gen", "", "Generate params given a Node ID.")
+	flag.Parse()
+	if *genParams != "" {
+		generateParams(*genParams)
+		os.Exit(0)
+	}
+
+	// Ok, guess we're in PT land.
+	ptInfo, err = pt.ServerSetup([]string{"obfs4"})
+	if err != nil {
+		os.Exit(1)
+	}
+
+	listeners := make([]net.Listener, 0)
+	for _, bindaddr := range ptInfo.Bindaddrs {
+		switch bindaddr.MethodName {
+		case "obfs4":
+			// Handle the mandetory arguments.
+			privateKey, ok := bindaddr.Options.Get("private-key")
+			if !ok {
+				pt.SmethodError(bindaddr.MethodName, "need a private-key option")
+				break
+			}
+			nodeID, ok := bindaddr.Options.Get("node-id")
+			if !ok {
+				pt.SmethodError(bindaddr.MethodName, "need a node-id option")
+				break
+			}
+
+			ln, err := obfs4.Listen("tcp", bindaddr.Addr.String(), nodeID,
+									privateKey)
+			if err != nil {
+				pt.SmethodError(bindaddr.MethodName, err.Error())
+				break
+			}
+
+			oLn, _ := ln.(*obfs4.Obfs4Listener)
+			args := pt.Args{}
+			args.Add("node-id", nodeID)
+			args.Add("public-key", oLn.PublicKey())
+			go acceptLoop(ln)
+			pt.SmethodArgs(bindaddr.MethodName, ln.Addr(), args)
+			// TODO: Maybe log the args?
+			listeners = append(listeners, ln)
+		default:
+			pt.SmethodError(bindaddr.MethodName, "no such method")
+		}
+	}
+	pt.SmethodsDone()
+
+	var numHandlers int = 0
+	var sig os.Signal
+	sigChan := make(chan os.Signal, 1)
+	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
+
+	// wait for first signal
+	sig = nil
+	for sig == nil {
+		select {
+		case n := <-handlerChan:
+			numHandlers += n
+		case sig = <-sigChan:
+		}
+	}
+	for _, ln := range listeners {
+		ln.Close()
+	}
+
+	if sig == syscall.SIGTERM {
+		return
+	}
+
+	// wait for second signal or no more handlers
+	sig = nil
+	for sig == nil && numHandlers != 0 {
+		select {
+		case n := <-handlerChan:
+			numHandlers += n
+		case sig = <-sigChan:
+		}
+	}
+}