path: root/cmd/wnode/main.go

// Copyright 2016 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"
    "crypto/sha1"
    "crypto/sha256"
    "crypto/sha512"
    "encoding/binary"
    "encoding/hex"
    "flag"
    "fmt"
    "os"
    "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/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"
    "github.com/ethereum/go-ethereum/whisper/mailserver"
    whisper "github.com/ethereum/go-ethereum/whisper/whisperv5"
    "golang.org/x/crypto/pbkdf2"
)

const quitCommand = "~Q"

// singletons
var (
    server     *p2p.Server
    shh        *whisper.Whisper
    done       chan struct{}
    mailServer mailserver.WMailServer

    input = bufio.NewReader(os.Stdin)
)

// encryption
var (
    symKey     []byte
    pub        *ecdsa.PublicKey
    asymKey    *ecdsa.PrivateKey
    nodeid     *ecdsa.PrivateKey
    topic      whisper.TopicType
    filterID   uint32
    msPassword string
)

// cmd arguments
var (
    echoMode       = flag.Bool("e", false, "echo mode: prints some arguments for diagnostics")
    bootstrapMode  = flag.Bool("b", false, "boostrap node: don't actively connect to peers, wait for incoming connections")
    forwarderMode  = flag.Bool("f", false, "forwarder mode: only forward messages, neither send nor decrypt messages")
    mailServerMode = flag.Bool("s", false, "mail server mode: delivers expired messages on demand")
    requestMail    = flag.Bool("r", false, "request expired messages from the bootstrap server")
    asymmetricMode = flag.Bool("a", false, "use asymmetric encryption")
    testMode       = flag.Bool("t", false, "use of predefined parameters for diagnostics")
    generateKey    = flag.Bool("k", false, "generate and show the private key")

    argTTL       = flag.Uint("ttl", 30, "time-to-live for messages in seconds")
    argWorkTime  = flag.Uint("work", 5, "work time in seconds")
    argPoW       = flag.Float64("pow", whisper.MinimumPoW, "PoW for normal messages in float format (e.g. 2.7)")
    argServerPoW = flag.Float64("mspow", whisper.MinimumPoW, "PoW requirement for Mail Server request")

    argIP     = flag.String("ip", "", "IP address and port of this node (e.g. 127.0.0.1:30303)")
    argSalt   = flag.String("salt", "", "salt (for topic and key derivation)")
    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)")
)

func main() {
    processArgs()
    initialize()
    run()
}

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 {
        pub = crypto.ToECDSAPub(common.FromHex(*argPub))
        if !isKeyValid(pub) {
            utils.Fatalf("invalid public key")
        }
    }

    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("salt = %s \n", *argSalt)
    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() {
    glog.SetV(logger.Warn)
    glog.SetToStderr(true)

    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 {
        password := []byte("test password for symmetric encryption")
        salt := []byte("test salt for symmetric encryption")
        symKey = pbkdf2.Key(password, salt, 64, 32, sha256.New)
        topic = whisper.TopicType{0xFF, 0xFF, 0xFF, 0xFF}
        msPassword = "mail server test password"
    }

    if *bootstrapMode {
        if len(*argIP) == 0 {
            argIP = scanLineA("Please enter your IP and port (e.g. 127.0.0.1:30348): ")
        }
    } 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)
            }
        }
        shh = whisper.New()
        shh.RegisterServer(&mailServer)
        mailServer.Init(shh, *argDBPath, msPassword, *argServerPoW)
    } else {
        shh = whisper.New()
    }

    asymKey = shh.NewIdentity()
    if nodeid == nil {
        nodeid = shh.NewIdentity()
    }

    maxPeers := 80
    if *bootstrapMode {
        maxPeers = 800
    }

    server = &p2p.Server{
        Config: p2p.Config{
            PrivateKey:     nodeid,
            MaxPeers:       maxPeers,
            Name:           common.MakeName("whisper-go", "5.0"),
            Protocols:      shh.Protocols(),
            ListenAddr:     *argIP,
            NAT:            nat.Any(),
            BootstrapNodes: peers,
            StaticNodes:    peers,
            TrustedNodes:   peers,
        },
    }
}

func startServer() {
    err := server.Start()
    if err != nil {
        utils.Fatalf("Failed to start Whisper peer: %s.", 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 !*forwarderMode {
        fmt.Printf("Please type the message. To quit type: '%s'\n", quitCommand)
    }
}

func isKeyValid(k *ecdsa.PublicKey) bool {
    return k.X != nil && k.Y != 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: ")
            pub = crypto.ToECDSAPub(common.FromHex(s))
            if !isKeyValid(pub) {
                utils.Fatalf("Error: invalid 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 && !*testMode {
        pass, err := console.Stdin.PromptPassword("Please enter the password: ")
        if err != nil {
            utils.Fatalf("Failed to read passphrase: %v", err)
        }

        if len(*argSalt) == 0 {
            argSalt = scanLineA("Please enter the salt: ")
        }

        symKey = pbkdf2.Key([]byte(pass), []byte(*argSalt), 65356, 32, sha256.New)

        if len(*argTopic) == 0 {
            generateTopic([]byte(pass), []byte(*argSalt))
        }
    }

    if *mailServerMode {
        if len(*argDBPath) == 0 {
            argDBPath = scanLineA("Please enter the path to DB file: ")
        }
    }

    filter := whisper.Filter{
        KeySym:    symKey,
        KeyAsym:   asymKey,
        Topics:    []whisper.TopicType{topic},
        AcceptP2P: p2pAccept,
    }
    filterID = shh.Watch(&filter)
    fmt.Printf("Filter is configured for the topic: %x \n", topic)
}

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 {
                utils.Fatalf("Timeout expired, failed to connect")
            }
        }
    }

    fmt.Println("Connected to peer.")
}

func run() {
    defer mailServer.Close()
    startServer()
    defer server.Stop()
    shh.Start(nil)
    defer shh.Stop()

    if !*forwarderMode {
        go messageLoop()
    }

    if *requestMail {
        requestExpiredMessagesLoop()
    } else {
        sendLoop()
    }
}

func sendLoop() {
    for {
        s := scanLine("")
        if s == quitCommand {
            fmt.Println("Quit command received")
            close(done)
            break
        }
        sendMsg([]byte(s))

        if *asymmetricMode {
            // 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(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) {
    params := whisper.MessageParams{
        Src:      asymKey,
        Dst:      pub,
        KeySym:   symKey,
        Payload:  payload,
        Topic:    topic,
        TTL:      uint32(*argTTL),
        PoW:      *argPoW,
        WorkTime: uint32(*argWorkTime),
    }

    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 {
        utils.Fatalf("filter is not installed")
    }

    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) {
    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 requestExpiredMessagesLoop() {
    var key, peerID []byte
    var timeLow, timeUpp uint32
    var t string
    var xt, empty whisper.TopicType

    err := shh.AddSymKey(mailserver.MailServerKeyName, []byte(msPassword))
    if err != nil {
        utils.Fatalf("Failed to create symmetric key for mail request: %s", err)
    }
    key = shh.GetSymKey(mailserver.MailServerKeyName)
    peerID = extractIdFromEnode(*argEnode)
    shh.MarkPeerTrusted(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("Please enter the topic (hexadecimal): ")
        if len(t) >= whisper.TopicLength*2 {
            x, err := hex.DecodeString(t)
            if err != nil {
                utils.Fatalf("Failed to parse the topic: %s", err)
            }
            xt = whisper.BytesToTopic(x)
        }
        if timeUpp == 0 {
            timeUpp = 0xFFFFFFFF
        }

        data := make([]byte, 8+whisper.TopicLength)
        binary.BigEndian.PutUint32(data, timeLow)
        binary.BigEndian.PutUint32(data[4:], timeUpp)
        copy(data[8:], xt[:])
        if xt == empty {
            data = data[:8]
        }

        var params whisper.MessageParams
        params.PoW = *argServerPoW
        params.Payload = data
        params.KeySym = key
        params.Src = nodeid
        params.WorkTime = 5

        msg := whisper.NewSentMessage(&params)
        env, err := msg.Wrap(&params)
        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 nil
    }
    return n.ID[:]
}