// Copyright 2017 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
// This is a simple Whisper node. It could be used as a stand-alone bootstrap node.
// Also, could be used for different test and diagnostics purposes.
package main
import (
"bufio"
"crypto/ecdsa"
crand "crypto/rand"
"crypto/sha512"
"encoding/binary"
"encoding/hex"
"flag"
"fmt"
"io/ioutil"
"os"
"path/filepath"
"strconv"
"strings"
"time"
"github.com/ethereum/go-ethereum/cmd/utils"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/console"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/discover"
"github.com/ethereum/go-ethereum/p2p/nat"
"github.com/ethereum/go-ethereum/whisper/mailserver"
whisper "github.com/ethereum/go-ethereum/whisper/whisperv6"
"golang.org/x/crypto/pbkdf2"
)
const quitCommand = "~Q"
const entropySize = 32
// singletons
var (
server *p2p.Server
shh *whisper.Whisper
done chan struct{}
mailServer mailserver.WMailServer
entropy [entropySize]byte
input = bufio.NewReader(os.Stdin)
)
// encryption
var (
symKey []byte
pub *ecdsa.PublicKey
asymKey *ecdsa.PrivateKey
nodeid *ecdsa.PrivateKey
topic whisper.TopicType
asymKeyID string
asymFilterID string
symFilterID string
symPass string
msPassword string
)
// cmd arguments
var (
bootstrapMode = flag.Bool("standalone", false, "boostrap node: don't initiate connection to peers, just wait for incoming connections")
forwarderMode = flag.Bool("forwarder", false, "forwarder mode: only forward messages, neither encrypt nor decrypt messages")
mailServerMode = flag.Bool("mailserver", false, "mail server mode: delivers expired messages on demand")
requestMail = flag.Bool("mailclient", false, "request expired messages from the bootstrap server")
asymmetricMode = flag.Bool("asym", false, "use asymmetric encryption")
generateKey = flag.Bool("generatekey", false, "generate and show the private key")
fileExMode = flag.Bool("fileexchange", false, "file exchange mode")
fileReader = flag.Bool("filereader", false, "load and decrypt messages saved as files, display as plain text")
testMode = flag.Bool("test", false, "use of predefined parameters for diagnostics (password, etc.)")
echoMode = flag.Bool("echo", false, "echo mode: prints some arguments for diagnostics")
argVerbosity = flag.Int("verbosity", int(log.LvlError), "log verbosity level")
argTTL = flag.Uint("ttl", 30, "time-to-live for messages in seconds")
argWorkTime = flag.Uint("work", 5, "work time in seconds")
argMaxSize = flag.Uint("maxsize", uint(whisper.DefaultMaxMessageSize), "max size of message")
argPoW = flag.Float64("pow", whisper.DefaultMinimumPoW, "PoW for normal messages in float format (e.g. 2.7)")
argServerPoW = flag.Float64("mspow", whisper.DefaultMinimumPoW, "PoW requirement for Mail Server request")
argIP = flag.String("ip", "", "IP address and port of this node (e.g. 127.0.0.1:30303)")
argPub = flag.String("pub", "", "public key for asymmetric encryption")
argDBPath = flag.String("dbpath", "", "path to the server's DB directory")
argIDFile = flag.String("idfile", "", "file name with node id (private key)")
argEnode = flag.String("boot", "", "bootstrap node you want to connect to (e.g. enode://e454......08d50@52.176.211.200:16428)")
argTopic = flag.String("topic", "", "topic in hexadecimal format (e.g. 70a4beef)")
argSaveDir = flag.String("savedir", "", "directory where all incoming messages will be saved as files")
)
func main() {
processArgs()
initialize()
run()
shutdown()
}
func processArgs() {
flag.Parse()
if len(*argIDFile) > 0 {
var err error
nodeid, err = crypto.LoadECDSA(*argIDFile)
if err != nil {
utils.Fatalf("Failed to load file [%s]: %s.", *argIDFile, err)
}
}
const enodePrefix = "enode://"
if len(*argEnode) > 0 {
if (*argEnode)[:len(enodePrefix)] != enodePrefix {
*argEnode = enodePrefix + *argEnode
}
}
if len(*argTopic) > 0 {
x, err := hex.DecodeString(*argTopic)
if err != nil {
utils.Fatalf("Failed to parse the topic: %s", err)
}
topic = whisper.BytesToTopic(x)
}
if *asymmetricMode && len(*argPub) > 0 {
var err error
if pub, err = crypto.UnmarshalPubkey(common.FromHex(*argPub)); err != nil {
utils.Fatalf("invalid public key")
}
}
if len(*argSaveDir) > 0 {
if _, err := os.Stat(*argSaveDir); os.IsNotExist(err) {
utils.Fatalf("Download directory '%s' does not exist", *argSaveDir)
}
} else if *fileExMode {
utils.Fatalf("Parameter 'savedir' is mandatory for file exchange mode")
}
if *echoMode {
echo()
}
}
func echo() {
fmt.Printf("ttl = %d \n", *argTTL)
fmt.Printf("workTime = %d \n", *argWorkTime)
fmt.Printf("pow = %f \n", *argPoW)
fmt.Printf("mspow = %f \n", *argServerPoW)
fmt.Printf("ip = %s \n", *argIP)
fmt.Printf("pub = %s \n", common.ToHex(crypto.FromECDSAPub(pub)))
fmt.Printf("idfile = %s \n", *argIDFile)
fmt.Printf("dbpath = %s \n", *argDBPath)
fmt.Printf("boot = %s \n", *argEnode)
}
func initialize() {
log.Root().SetHandler(log.LvlFilterHandler(log.Lvl(*argVerbosity), log.StreamHandler(os.Stderr, log.TerminalFormat(false))))
done = make(chan struct{})
var peers []*discover.Node
var err error
if *generateKey {
key, err := crypto.GenerateKey()
if err != nil {
utils.Fatalf("Failed to generate private key: %s", err)
}
k := hex.EncodeToString(crypto.FromECDSA(key))
fmt.Printf("Random private key: %s \n", k)
os.Exit(0)
}
if *testMode {
symPass = "wwww" // ascii code: 0x77777777
msPassword = "wwww"
}
if *bootstrapMode {
if len(*argIP) == 0 {
argIP = scanLineA("Please enter your IP and port (e.g. 127.0.0.1:30348): ")
}
} else if *fileReader {
*bootstrapMode = true
} else {
if len(*argEnode) == 0 {
argEnode = scanLineA("Please enter the peer's enode: ")
}
peer := discover.MustParseNode(*argEnode)
peers = append(peers, peer)
}
if *mailServerMode {
if len(msPassword) == 0 {
msPassword, err = console.Stdin.PromptPassword("Please enter the Mail Server password: ")
if err != nil {
utils.Fatalf("Failed to read Mail Server password: %s", err)
}
}
}
cfg := &whisper.Config{
MaxMessageSize: uint32(*argMaxSize),
MinimumAcceptedPOW: *argPoW,
}
shh = whisper.New(cfg)
if *argPoW != whisper.DefaultMinimumPoW {
err := shh.SetMinimumPoW(*argPoW)
if err != nil {
utils.Fatalf("Failed to set PoW: %s", err)
}
}
if uint32(*argMaxSize) != whisper.DefaultMaxMessageSize {
err := shh.SetMaxMessageSize(uint32(*argMaxSize))
if err != nil {
utils.Fatalf("Failed to set max message size: %s", err)
}
}
asymKeyID, err = shh.NewKeyPair()
if err != nil {
utils.Fatalf("Failed to generate a new key pair: %s", err)
}
asymKey, err = shh.GetPrivateKey(asymKeyID)
if err != nil {
utils.Fatalf("Failed to retrieve a new key pair: %s", err)
}
if nodeid == nil {
tmpID, err := shh.NewKeyPair()
if err != nil {
utils.Fatalf("Failed to generate a new key pair: %s", err)
}
nodeid, err = shh.GetPrivateKey(tmpID)
if err != nil {
utils.Fatalf("Failed to retrieve a new key pair: %s", err)
}
}
maxPeers := 80
if *bootstrapMode {
maxPeers = 800
}
_, err = crand.Read(entropy[:])
if err != nil {
utils.Fatalf("crypto/rand failed: %s", err)
}
if *mailServerMode {
shh.RegisterServer(&mailServer)
if err := mailServer.Init(shh, *argDBPath, msPassword, *argServerPoW); err != nil {
utils.Fatalf("Failed to init MailServer: %s", err)
}
}
server = &p2p.Server{
Config: p2p.Config{
PrivateKey: nodeid,
MaxPeers: maxPeers,
Name: common.MakeName("wnode", "6.0"),
Protocols: shh.Protocols(),
ListenAddr: *argIP,
NAT: nat.Any(),
BootstrapNodes: peers,
StaticNodes: peers,
TrustedNodes: peers,
},
}
}
func startServer() error {
err := server.Start()
if err != nil {
fmt.Printf("Failed to start Whisper peer: %s.", err)
return err
}
fmt.Printf("my public key: %s \n", common.ToHex(crypto.FromECDSAPub(&asymKey.PublicKey)))
fmt.Println(server.NodeInfo().Enode)
if *bootstrapMode {
configureNode()
fmt.Println("Bootstrap Whisper node started")
} else {
fmt.Println("Whisper node started")
// first see if we can establish connection, then ask for user input
waitForConnection(true)
configureNode()
}
if *fileExMode {
fmt.Printf("Please type the file name to be send. To quit type: '%s'\n", quitCommand)
} else if *fileReader {
fmt.Printf("Please type the file name to be decrypted. To quit type: '%s'\n", quitCommand)
} else if !*forwarderMode {
fmt.Printf("Please type the message. To quit type: '%s'\n", quitCommand)
}
return nil
}
func configureNode() {
var err error
var p2pAccept bool
if *forwarderMode {
return
}
if *asymmetricMode {
if len(*argPub) == 0 {
s := scanLine("Please enter the peer's public key: ")
b := common.FromHex(s)
if b == nil {
utils.Fatalf("Error: can not convert hexadecimal string")
}
if pub, err = crypto.UnmarshalPubkey(b); err != nil {
utils.Fatalf("Error: invalid peer public key")
}
}
}
if *requestMail {
p2pAccept = true
if len(msPassword) == 0 {
msPassword, err = console.Stdin.PromptPassword("Please enter the Mail Server password: ")
if err != nil {
utils.Fatalf("Failed to read Mail Server password: %s", err)
}
}
}
if !*asymmetricMode && !*forwarderMode {
if len(symPass) == 0 {
symPass, err = console.Stdin.PromptPassword("Please enter the password for symmetric encryption: ")
if err != nil {
utils.Fatalf("Failed to read passphrase: %v", err)
}
}
symKeyID, err := shh.AddSymKeyFromPassword(symPass)
if err != nil {
utils.Fatalf("Failed to create symmetric key: %s", err)
}
symKey, err = shh.GetSymKey(symKeyID)
if err != nil {
utils.Fatalf("Failed to save symmetric key: %s", err)
}
if len(*argTopic) == 0 {
generateTopic([]byte(symPass))
}
fmt.Printf("Filter is configured for the topic: %x \n", topic)
}
if *mailServerMode {
if len(*argDBPath) == 0 {
argDBPath = scanLineA("Please enter the path to DB file: ")
}
}
symFilter := whisper.Filter{
KeySym: symKey,
Topics: [][]byte{topic[:]},
AllowP2P: p2pAccept,
}
symFilterID, err = shh.Subscribe(&symFilter)
if err != nil {
utils.Fatalf("Failed to install filter: %s", err)
}
asymFilter := whisper.Filter{
KeyAsym: asymKey,
Topics: [][]byte{topic[:]},
AllowP2P: p2pAccept,
}
asymFilterID, err = shh.Subscribe(&asymFilter)
if err != nil {
utils.Fatalf("Failed to install filter: %s", err)
}
}
func generateTopic(password []byte) {
x := pbkdf2.Key(password, password, 4096, 128, sha512.New)
for i := 0; i < len(x); i++ {
topic[i%whisper.TopicLength] ^= x[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 {
utils.Fatalf("Timeout expired, failed to connect")
}
}
}
fmt.Println("Connected to peer.")
}
func run() {
err := startServer()
if err != nil {
return
}
defer server.Stop()
shh.Start(nil)
defer shh.Stop()
if !*forwarderMode {
go messageLoop()
}
if *requestMail {
requestExpiredMessagesLoop()
} else if *fileExMode {
sendFilesLoop()
} else if *fileReader {
fileReaderLoop()
} else {
sendLoop()
}
}
func shutdown() {
close(done)
mailServer.Close()
}
func sendLoop() {
for {
s := scanLine("")
if s == quitCommand {
fmt.Println("Quit command received")
return
}
sendMsg([]byte(s))
if *asymmetricMode {
// print your own message for convenience,
// because in asymmetric mode it is impossible to decrypt it
timestamp := time.Now().Unix()
from := crypto.PubkeyToAddress(asymKey.PublicKey)
fmt.Printf("\n%d <%x>: %s\n", timestamp, from, s)
}
}
}
func sendFilesLoop() {
for {
s := scanLine("")
if s == quitCommand {
fmt.Println("Quit command received")
return
}
b, err := ioutil.ReadFile(s)
if err != nil {
fmt.Printf(">>> Error: %s \n", err)
} else {
h := sendMsg(b)
if (h == common.Hash{}) {
fmt.Printf(">>> Error: message was not sent \n")
} else {
timestamp := time.Now().Unix()
from := crypto.PubkeyToAddress(asymKey.PublicKey)
fmt.Printf("\n%d <%x>: sent message with hash %x\n", timestamp, from, h)
}
}
}
}
func fileReaderLoop() {
watcher1 := shh.GetFilter(symFilterID)
watcher2 := shh.GetFilter(asymFilterID)
if watcher1 == nil && watcher2 == nil {
fmt.Println("Error: neither symmetric nor asymmetric filter is installed")
return
}
for {
s := scanLine("")
if s == quitCommand {
fmt.Println("Quit command received")
return
}
raw, err := ioutil.ReadFile(s)
if err != nil {
fmt.Printf(">>> Error: %s \n", err)
} else {
env := whisper.Envelope{Data: raw} // the topic is zero
msg := env.Open(watcher1) // force-open envelope regardless of the topic
if msg == nil {
msg = env.Open(watcher2)
}
if msg == nil {
fmt.Printf(">>> Error: failed to decrypt the message \n")
} else {
printMessageInfo(msg)
}
}
}
}
func scanLine(prompt string) string {
if len(prompt) > 0 {
fmt.Print(prompt)
}
txt, err := input.ReadString('\n')
if err != nil {
utils.Fatalf("input error: %s", err)
}
txt = strings.TrimRight(txt, "\n\r")
return txt
}
func scanLineA(prompt string) *string {
s := scanLine(prompt)
return &s
}
func scanUint(prompt string) uint32 {
s := scanLine(prompt)
i, err := strconv.Atoi(s)
if err != nil {
utils.Fatalf("Fail to parse the lower time limit: %s", err)
}
return uint32(i)
}
func sendMsg(payload []byte) common.Hash {
params := whisper.MessageParams{
Src: asymKey,
Dst: pub,
KeySym: symKey,
Payload: payload,
Topic: topic,
TTL: uint32(*argTTL),
PoW: *argPoW,
WorkTime: uint32(*argWorkTime),
}
msg, err := whisper.NewSentMessage(¶ms)
if err != nil {
utils.Fatalf("failed to create new message: %s", err)
}
envelope, err := msg.Wrap(¶ms)
if err != nil {
fmt.Printf("failed to seal message: %v \n", err)
return common.Hash{}
}
err = shh.Send(envelope)
if err != nil {
fmt.Printf("failed to send message: %v \n", err)
return common.Hash{}
}
return envelope.Hash()
}
func messageLoop() {
sf := shh.GetFilter(symFilterID)
if sf == nil {
utils.Fatalf("symmetric filter is not installed")
}
af := shh.GetFilter(asymFilterID)
if af == nil {
utils.Fatalf("asymmetric filter is not installed")
}
ticker := time.NewTicker(time.Millisecond * 50)
for {
select {
case <-ticker.C:
m1 := sf.Retrieve()
m2 := af.Retrieve()
messages := append(m1, m2...)
for _, msg := range messages {
reportedOnce := false
if !*fileExMode && len(msg.Payload) <= 2048 {
printMessageInfo(msg)
reportedOnce = true
}
// All messages are saved upon specifying argSaveDir.
// fileExMode only specifies how messages are displayed on the console after they are saved.
// if fileExMode == true, only the hashes are displayed, since messages might be too big.
if len(*argSaveDir) > 0 {
writeMessageToFile(*argSaveDir, msg, !reportedOnce)
}
}
case <-done:
return
}
}
}
func printMessageInfo(msg *whisper.ReceivedMessage) {
timestamp := fmt.Sprintf("%d", msg.Sent) // unix timestamp for diagnostics
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
}
}
func writeMessageToFile(dir string, msg *whisper.ReceivedMessage, show bool) {
if len(dir) == 0 {
return
}
timestamp := fmt.Sprintf("%d", msg.Sent)
name := fmt.Sprintf("%x", msg.EnvelopeHash)
var address common.Address
if msg.Src != nil {
address = crypto.PubkeyToAddress(*msg.Src)
}
env := shh.GetEnvelope(msg.EnvelopeHash)
if env == nil {
fmt.Printf("\nUnexpected error: envelope not found: %x\n", msg.EnvelopeHash)
return
}
// this is a sample code; uncomment if you don't want to save your own messages.
//if whisper.IsPubKeyEqual(msg.Src, &asymKey.PublicKey) {
// fmt.Printf("\n%s <%x>: message from myself received, not saved: '%s'\n", timestamp, address, name)
// return
//}
fullpath := filepath.Join(dir, name)
err := ioutil.WriteFile(fullpath, env.Data, 0644)
if err != nil {
fmt.Printf("\n%s {%x}: message received but not saved: %s\n", timestamp, address, err)
} else if show {
fmt.Printf("\n%s {%x}: message received and saved as '%s' (%d bytes)\n", timestamp, address, name, len(env.Data))
}
}
func requestExpiredMessagesLoop() {
var key, peerID, bloom []byte
var timeLow, timeUpp uint32
var t string
var xt whisper.TopicType
keyID, err := shh.AddSymKeyFromPassword(msPassword)
if err != nil {
utils.Fatalf("Failed to create symmetric key for mail request: %s", err)
}
key, err = shh.GetSymKey(keyID)
if err != nil {
utils.Fatalf("Failed to save symmetric key for mail request: %s", err)
}
peerID = extractIDFromEnode(*argEnode)
shh.AllowP2PMessagesFromPeer(peerID)
for {
timeLow = scanUint("Please enter the lower limit of the time range (unix timestamp): ")
timeUpp = scanUint("Please enter the upper limit of the time range (unix timestamp): ")
t = scanLine("Enter the topic (hex). Press enter to request all messages, regardless of the topic: ")
if len(t) == whisper.TopicLength*2 {
x, err := hex.DecodeString(t)
if err != nil {
fmt.Printf("Failed to parse the topic: %s \n", err)
continue
}
xt = whisper.BytesToTopic(x)
bloom = whisper.TopicToBloom(xt)
obfuscateBloom(bloom)
} else if len(t) == 0 {
bloom = whisper.MakeFullNodeBloom()
} else {
fmt.Println("Error: topic is invalid, request aborted")
continue
}
if timeUpp == 0 {
timeUpp = 0xFFFFFFFF
}
data := make([]byte, 8, 8+whisper.BloomFilterSize)
binary.BigEndian.PutUint32(data, timeLow)
binary.BigEndian.PutUint32(data[4:], timeUpp)
data = append(data, bloom...)
var params whisper.MessageParams
params.PoW = *argServerPoW
params.Payload = data
params.KeySym = key
params.Src = asymKey
params.WorkTime = 5
msg, err := whisper.NewSentMessage(¶ms)
if err != nil {
utils.Fatalf("failed to create new message: %s", err)
}
env, err := msg.Wrap(¶ms)
if err != nil {
utils.Fatalf("Wrap failed: %s", err)
}
err = shh.RequestHistoricMessages(peerID, env)
if err != nil {
utils.Fatalf("Failed to send P2P message: %s", err)
}
time.Sleep(time.Second * 5)
}
}
func extractIDFromEnode(s string) []byte {
n, err := discover.ParseNode(s)
if err != nil {
utils.Fatalf("Failed to parse enode: %s", err)
}
return n.ID[:]
}
// obfuscateBloom adds 16 random bits to the bloom
// filter, in order to obfuscate the containing topics.
// it does so deterministically within every session.
// despite additional bits, it will match on average
// 32000 times less messages than full node's bloom filter.
func obfuscateBloom(bloom []byte) {
const half = entropySize / 2
for i := 0; i < half; i++ {
x := int(entropy[i])
if entropy[half+i] < 128 {
x += 256
}
bloom[x/8] = 1 << uint(x%8) // set the bit number X
}
}
