whisper: command-line tool (whisper node) introduced

whisper/wnode/main.go

@@ -0,0 +1,477 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// This is a simple Whisper node.
+// It also implements a command line chat between the peers sharing the same credentials.
+
+package main
+
+import (
+	"bufio"
+	"crypto/ecdsa"
+	"crypto/sha1"
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/hex"
+	"fmt"
+	"os"
+	"strconv"
+	"syscall"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/p2p/nat"
+	whisper "github.com/ethereum/go-ethereum/whisper/whisperv5"
+	"golang.org/x/crypto/pbkdf2"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+var input *bufio.Reader
+var done chan struct{}
+var server p2p.Server
+var shh *whisper.Whisper
+var asymKey *ecdsa.PrivateKey // used for asymmetric decryption and signing
+var pub *ecdsa.PublicKey      // used for asymmetric encryption
+var symKey []byte             // used for symmetric encryption
+var filter whisper.Filter
+var filterID uint32
+var topic whisper.TopicType
+var pow float64 = whisper.MinimumPoW
+var ttl uint32 = 30
+var workTime uint32 = 5
+var ipAddress, enode, salt, topicStr, pubStr string
+
+var bootstrapNode bool // does not actively connect to peers, wait for incoming connections
+var daemonMode bool    // only forward messages, neither send nor track
+var testMode bool      // predefined password, topic, ip and port
+var echoMode bool      // shows params, etc.
+var isAsymmetric bool
+
+var argNameHelp string = "-h"
+var argNameBootstrap string = "-b"
+var argNameDaemon string = "-d"
+var argNameAsymmetric string = "-a"
+var argNameTest string = "-test"
+var argNameEcho string = "-echo"
+var argNameWorkTime string = "-work"
+var argNameTTL string = "-ttl"
+var argNameIP string = "-ip"
+var argNameTopic string = "-topic"
+var argNamePoW string = "-pow"
+var argNameSalt string = "-salt"
+var argNamePub string = "-pub"
+var argNameEnode string = "-enode"
+var quitCommand string = "/q/"
+
+func printHelp() {
+	fmt.Println("wchat is a stand-alone whisper node with command-line interface.")
+	fmt.Println("wchat also allows to set up a chat using either symmetric or asymmetric encryption.\n")
+	fmt.Println("usage: wchat [arguments]")
+	fmt.Printf("    %s\t\t boostrap node: don't actively connect to peers, wait for incoming connections\n", argNameBootstrap)
+	fmt.Printf("    %s\t\t daemon mode: only forward messages, neither send nor decrypt messages \n", argNameDaemon)
+	fmt.Printf("    %s\t\t use asymmetric encryption \n", argNameAsymmetric)
+	fmt.Printf("    %s\t\t test mode: predefined password, topic, ip and port \n", argNameTest)
+	fmt.Printf("    %s\t\t echo mode: shows arguments \n", argNameEcho)
+	fmt.Printf("    %s\t\t work time in seconds (e.g. -w=12) \n", argNameWorkTime)
+	fmt.Printf("    %s\t\t time-to-live for messages in seconds (e.g. -l=30) \n", argNameTTL)
+	fmt.Printf("    %s\t\t IP address and port of this node (e.g. 127.0.0.1:30303) \n", argNameIP)
+	fmt.Printf("    %s\t\t topic in hexadecimal format (e.g. 0f45beef) \n", argNameTopic)
+	fmt.Printf("    %s\t\t public key for asymmetric encryption \n", argNamePub)
+	fmt.Printf("    %s\t\t PoW in integer format \n", argNamePoW)
+	fmt.Printf("    %s\t\t salt \n", argNameSalt)
+	fmt.Printf("    %s\t\t enode \n", argNameEnode)
+	fmt.Printf("    %s\t\t help \n", argNameHelp)
+}
+
+func main() {
+	parseArgs()
+	initialize()
+	run()
+}
+
+func parseArgs() {
+	var p uint32
+	help1 := checkMode(argNameHelp)
+	help2 := checkMode("-help")
+	help3 := checkMode("--help")
+	if help1 || help2 || help3 {
+		printHelp()
+		os.Exit(0)
+	}
+
+	bootstrapNode = checkMode(argNameBootstrap)
+	daemonMode = checkMode(argNameDaemon)
+	testMode = checkMode(argNameTest)
+	echoMode = checkMode(argNameEcho)
+	isAsymmetric = checkMode(argNameAsymmetric)
+
+	checkIntArg(argNameTTL, &ttl)
+	checkIntArg(argNameWorkTime, &workTime)
+	checkIntArg(argNamePoW, &p)
+	checkStringArg(argNameIP, &ipAddress)
+	checkStringArg(argNameEnode, &enode)
+	checkStringArg(argNameSalt, &salt)
+	checkStringArg(argNameTopic, &topicStr)
+	checkStringArg(argNamePub, &pubStr)
+
+	if p > 0 {
+		pow = float64(p)
+	}
+
+	if len(topicStr) > 0 {
+		var x []byte
+		x, err := hex.DecodeString(topicStr)
+		if err != nil {
+			fmt.Printf("Failed to parse the topic: %s \n", err)
+			os.Exit(0)
+		}
+		topic = whisper.BytesToTopic(x)
+	}
+
+	if isAsymmetric && len(pubStr) > 0 {
+		pub = crypto.ToECDSAPub(common.FromHex(pubStr))
+		if !isKeyValid(pub) {
+			fmt.Println("Error: invalid public key")
+			os.Exit(0)
+		}
+	}
+
+	if echoMode {
+		fmt.Printf("ttl = %d \n", ttl)
+		fmt.Printf("workTime = %d \n", workTime)
+		fmt.Printf("pow = %f \n", pow)
+		fmt.Printf("ip = %s \n", ipAddress)
+		fmt.Printf("salt = %s \n", salt)
+		fmt.Printf("topic = %x \n", topic)
+		fmt.Printf("pub = %s \n", common.ToHex(crypto.FromECDSAPub(pub)))
+		fmt.Printf("enode = %s \n", enode)
+	}
+}
+
+func checkIntArg(pattern string, dst *uint32) {
+	pattern += "="
+	sz := len(pattern)
+	for _, arg := range os.Args {
+		if len(arg) < sz {
+			continue
+		}
+
+		prefix := arg[:sz]
+		if prefix == pattern {
+			s := arg[sz:]
+			i, err := strconv.ParseUint(s, 10, 0)
+			if err != nil {
+				fmt.Printf("Failed to parse argument %s: %s \n", pattern, err)
+				os.Exit(0)
+			}
+			if err == nil && i > 0 {
+				*dst = uint32(i)
+			}
+			return
+		}
+	}
+}
+
+func checkStringArg(pattern string, dst *string) {
+	pattern += "="
+	sz := len(pattern)
+	for _, arg := range os.Args {
+		if len(arg) < sz {
+			continue
+		}
+
+		prefix := arg[:sz]
+		if prefix == pattern {
+			s := arg[sz:]
+			if len(s) > 0 {
+				*dst = s
+			}
+			return
+		}
+	}
+}
+
+func checkMode(pattern string) bool {
+	for _, arg := range os.Args {
+		if arg == pattern {
+			return true
+		}
+	}
+	return false
+}
+
+func initialize() {
+	glog.SetV(logger.Warn)
+	glog.SetToStderr(true)
+
+	done = make(chan struct{})
+	input = bufio.NewReader(os.Stdin)
+	var peers []*discover.Node
+
+	if testMode {
+		password := []byte("this is a test password for symmetric encryption")
+		salt := []byte("this is a test salt for symmetric encryption")
+		symKey = pbkdf2.Key(password, salt, 64, 32, sha256.New)
+		topic = whisper.TopicType{0xFF, 0xFF, 0xFF, 0xFF}
+	}
+
+	if bootstrapNode {
+		if len(ipAddress) == 0 {
+			if testMode {
+				ipAddress = "127.0.0.1:30303"
+			} else {
+				fmt.Printf("Please enter your IP and port (e.g. 127.0.0.1:30303): ")
+				fmt.Scanln(&ipAddress)
+			}
+		}
+	} else {
+		if len(enode) == 0 {
+			fmt.Printf("Please enter the peer's enode: ")
+			fmt.Scanln(&enode)
+		}
+		peer := discover.MustParseNode(enode)
+		peers = append(peers, peer)
+	}
+
+	shh = whisper.NewWhisper(nil)
+	myNodeId := shh.NewIdentity()
+	asymKey = shh.NewIdentity()
+
+	server = p2p.Server{
+		Config: p2p.Config{
+			PrivateKey:     myNodeId,
+			MaxPeers:       48,
+			Name:           common.MakeName("whisper-go", "5.0"),
+			Protocols:      shh.Protocols(),
+			ListenAddr:     ipAddress,
+			NAT:            nat.Any(),
+			BootstrapNodes: peers,
+			StaticNodes:    peers,
+			TrustedNodes:   peers,
+		},
+	}
+}
+
+func startServer() {
+	err := server.Start()
+	if err != nil {
+		fmt.Printf("Failed to start Whsiper peer: %s.\n", err)
+		os.Exit(0)
+	}
+
+	fmt.Printf("my public key: %s \n", common.ToHex(crypto.FromECDSAPub(&asymKey.PublicKey)))
+	fmt.Println(server.NodeInfo().Enode)
+
+	if bootstrapNode {
+		configureChat()
+		fmt.Println("Bootstrap Whisper node started")
+		waitForConnection(false)
+	} else {
+		fmt.Println("Whisper node started")
+		// first see if we can establish connection, then require futher user input
+		waitForConnection(true)
+		configureChat()
+	}
+
+	if !daemonMode {
+		fmt.Printf("Chat is enabled. Please type the message. To quit type: '%s'\n", quitCommand)
+	}
+}
+
+func isKeyValid(k *ecdsa.PublicKey) bool {
+	return k.X != nil && k.Y != nil
+}
+
+func configureChat() {
+	if daemonMode {
+		return
+	}
+
+	if isAsymmetric && len(pubStr) == 0 {
+		fmt.Printf("Please enter the peer's public key: ")
+		pubStr = scanLine()
+		pub = crypto.ToECDSAPub(common.FromHex(pubStr))
+		if !isKeyValid(pub) {
+			fmt.Println("Error: invalid public key")
+			os.Exit(0)
+		}
+	}
+
+	if !isAsymmetric && !testMode {
+		fmt.Printf("Please enter the password: ")
+		pass, err := terminal.ReadPassword(syscall.Stdin)
+		fmt.Println()
+		if err != nil {
+			fmt.Printf("Error: %s \n", err)
+			os.Exit(0)
+		}
+
+		if len(salt) == 0 {
+			fmt.Printf("Please enter the salt: ")
+			salt = scanLine()
+		}
+
+		symKey = pbkdf2.Key(pass, []byte(salt), 65356, 32, sha256.New)
+
+		if len(topicStr) == 0 {
+			generateTopic(pass, []byte(salt))
+		}
+	}
+
+	filter = whisper.Filter{KeySym: symKey, KeyAsym: asymKey, Topics: []whisper.TopicType{topic}}
+	filterID = shh.Watch(&filter)
+}
+
+func generateTopic(password, salt []byte) {
+	const rounds = 4000
+	const size = 128
+	x1 := pbkdf2.Key(password, salt, rounds, size, sha512.New)
+	x2 := pbkdf2.Key(password, salt, rounds, size, sha1.New)
+	x3 := pbkdf2.Key(x1, x2, rounds, size, sha256.New)
+
+	for i := 0; i < size; i++ {
+		topic[i%whisper.TopicLength] ^= x3[i]
+	}
+}
+
+func waitForConnection(timeout bool) {
+	var cnt int
+	var connected bool
+	for !connected {
+		time.Sleep(time.Millisecond * 50)
+		connected = server.PeerCount() > 0
+		if timeout {
+			cnt++
+			if cnt > 1000 {
+				fmt.Println("Timeout expired, failed to connect")
+				os.Exit(0)
+			}
+		}
+	}
+
+	fmt.Println("Connected to peer.")
+}
+
+func run() {
+	startServer()
+	defer server.Stop()
+	shh.Start(nil)
+	defer shh.Stop()
+
+	if !daemonMode {
+		go messageLoop()
+	}
+
+	for {
+		s := scanLine()
+		if s == quitCommand {
+			fmt.Println("Quit command received")
+			close(done)
+			break
+		}
+		sendMsg([]byte(s))
+
+		if isAsymmetric {
+			// print your own message for convenience,
+			// because in asymmetric mode it is impossible to decrypt it
+			hour, min, sec := time.Now().Clock()
+			from := crypto.PubkeyToAddress(asymKey.PublicKey)
+			fmt.Printf("\n%02d:%02d:%02d <%x>: %s\n", hour, min, sec, from, s)
+		}
+	}
+}
+
+func scanLine() string {
+	txt, err := input.ReadString('\n')
+	if err != nil {
+		fmt.Printf("input error: %s \n", err)
+		os.Exit(0)
+	}
+	last := len(txt) - 1
+	if txt[last] == '\n' {
+		return txt[:last] // without the trailing newline
+	}
+	return txt
+}
+
+func sendMsg(payload []byte) {
+	params := whisper.MessageParams{
+		Src:      asymKey,
+		Dst:      pub,
+		KeySym:   symKey,
+		Payload:  payload,
+		Topic:    topic,
+		TTL:      ttl,
+		PoW:      pow,
+		WorkTime: workTime,
+	}
+
+	msg := whisper.NewSentMessage(&params)
+	envelope, err := msg.Wrap(&params)
+	if err != nil {
+		fmt.Printf("failed to seal message: %v \n", err)
+		return
+	}
+
+	err = shh.Send(envelope)
+	if err != nil {
+		fmt.Printf("failed to send message: %v \n", err)
+	}
+}
+
+func messageLoop() {
+	f := shh.GetFilter(filterID)
+	if f == nil {
+		fmt.Println("error: filter is not installed!")
+		os.Exit(0)
+	}
+
+	ticker := time.NewTicker(time.Millisecond * 50)
+
+	for {
+		select {
+		case <-ticker.C:
+			messages := f.Retrieve()
+			for _, msg := range messages {
+				printMessageInfo(msg)
+			}
+		case <-done:
+			return
+		}
+	}
+}
+
+func printMessageInfo(msg *whisper.ReceivedMessage) {
+	hour, min, sec := time.Now().Clock()
+	timestamp := fmt.Sprintf("%02d:%02d:%02d", hour, min, sec)
+	text := string(msg.Payload)
+
+	var address common.Address
+	if msg.Src != nil {
+		address = crypto.PubkeyToAddress(*msg.Src)
+	}
+
+	if whisper.IsPubKeyEqual(msg.Src, &asymKey.PublicKey) {
+		fmt.Printf("\n%s <%x>: %s\n", timestamp, address, text) // message from myself
+	} else {
+		fmt.Printf("\n%s [%x]: %s\n", timestamp, address, text) // message from a peer
+	}
+}