sendafriend/main.go

package main

import (
	"bufio"
	"cwtch.im/cwtch/model"
	libpeer "cwtch.im/cwtch/peer"
	"fmt"
	"github.com/sethvargo/go-diceware/diceware"
		"math/big"
	"os"
	"time"
	"path"
	"os/user"
	"strings"
	"log"
	"io/ioutil"
	"sync"
	"cwtch.im/cwtch/peer/connections"
)

func driftoff() {
	time.Sleep(time.Second * 7)
	os.Exit(1)
}

func addContactEntry(peer libpeer.CwtchPeer, name string, onion string) {
	pp := model.PublicProfile{
		name,
		nil,
		false,
		false,
		onion}

	if peer == nil {
		fmt.Printf("peer is nil?!?!?\n")
	}

	peer.GetProfile().Contacts[onion] = &pp
	peer.GetProfile().SetCustomAttribute(onion+"_name", name)
	peer.GetProfile().SetCustomAttribute(name+"_onion", onion)
}

func exitOnEnter() {
	fmt.Println("okay, now have your friend type \"sendafriend seek\" and enter the secret")
	fmt.Println("or press enter to cancel the game and exit")
	reader := bufio.NewReader(os.Stdin)
	reader.ReadString('\n')
	os.Exit(0)
}

func printHelp() {
	fmt.Println("usage: sendafriend [command] [options]\nCommands: help, setname, info, list, add, send, receive, hide, seek")
}

func main() {
	if len(os.Args) < 2 {
		printHelp()
		os.Exit(1)
	}

	if os.Getenv("SENDAFRIEND_DEBUG") != "YES" {
		log.SetFlags(0)
		log.SetOutput(ioutil.Discard)
	}

	// this is a cwtch server used only to make the "pair" command work
	// it is completely untrusted and only blinded information is passed through it
	// it can point to any ol cwtch group, as long as both people running "pair" are using the same one
	inviteStr := "torv30I0zJgNiUz57gJlxFsp4PUq47WDoKNCL95GEadaLlEE=EsABCiA1MjQzYjNkNzczMjAwNzc1MDExMDI0MjJkM2NkOGNmZBIgsXZKp350ShZ2l3iqOh4ZhGJmj0Etb5QmkL5iLZno9AQaOGZxcWJkNWxrNzRnbG5zZ292aXVuNm92Z3V0MmNqY252Mm12aWdvamNuc21wd3NucTJ5ZGpmM3FkIkD5x/JNhpLVe982dE9+3mp1IEog6O8yGdrIuUs0Tb6F1Fh1J1zuv1nJBFECuzYyF1yhqNvOn9Z6MatXVi+PKQIO"

	var dirname, filename string
	if os.Getenv("SENDAFRIEND_FOLDER") != "" {
		dirname = os.Getenv("SENDAFRIEND_FOLDER")
		filename = path.Join(dirname, "identity.private")
	} else {
		usr, err := user.Current()
		if err != nil {
			fmt.Printf("\nerror: could not load current user: %v\n", err)
			os.Exit(1)
		}
		dirname = path.Join(usr.HomeDir, ".sendafriend")
		filename = path.Join(dirname, "identity.private")
	}

	os.MkdirAll(dirname, 0700)
	peer, err := libpeer.LoadCwtchPeer(filename, "be gay do crime")
	if err != nil {
		fmt.Println("couldn't load your config file, attempting to create a new one now")

		names, err := diceware.Generate(1)
		peer, err = libpeer.NewCwtchPeer(names[0], "be gay do crime", filename)
		if err != nil {
			fmt.Println("couldn't create one either :( exiting")
			os.Exit(1)
		}
	}

	switch os.Args[1] {
	default:
		printHelp()
	case "help":
		printHelp()
	case "iam":
		if len(os.Args) != 3 {
			fmt.Println("example: sendafriend iam alice")
			os.Exit(1)
		}

		peer.GetProfile().Name = os.Args[2]
		fmt.Printf("hi, %v!\n", os.Args[2])
	case "setname":
		if len(os.Args) == 3 {
			fmt.Println("example: sendafriend setname alice xyz")
			os.Exit(1)
		}

		_, exists := peer.GetProfile().GetCustomAttribute(os.Args[3] + "_name")
		if !exists {
			fmt.Printf("um you don't have anyone with that onion address in your list")
			os.Exit(1)
		}

		peer.GetProfile().SetCustomAttribute(os.Args[3]+"_name", os.Args[2])
		peer.GetProfile().SetCustomAttribute(os.Args[2]+"_onion", os.Args[3])
		//todo: unset old one
		fmt.Printf("okay, i'll remember that %v is named %v\n", os.Args[3], os.Args[2])
	case "info":
		fmt.Printf("your name is currently %v and your address is currently %v\n", peer.GetProfile().Name, peer.GetProfile().Onion)
	case "list":
		contacts := peer.GetContacts()
		for i := range contacts {
			attr, _ := peer.GetProfile().GetCustomAttribute(contacts[i] + "_name")
			fmt.Printf("%v <%v>\n", attr, contacts[i])
		}
	case "add":
		if len(os.Args) != 4 {
			fmt.Println("example: sendafriend add bob xyz")
			os.Exit(1)
		}

		_, exists := peer.GetProfile().GetCustomAttribute(os.Args[3] + "_name")
		if exists {
			fmt.Printf("woah you already have someone named %v\n", os.Args[3])
			os.Exit(1)
		}

		addContactEntry(peer, os.Args[2], os.Args[3])

		fmt.Printf("okay, added %v <%v>\n", os.Args[2], os.Args[3])
	case "send":
		if len(os.Args) != 3 {
			fmt.Println("example: sendafriend send bob < file.txt")
			os.Exit(1)
		}

		onion, exists := peer.GetProfile().GetCustomAttribute(os.Args[2] + "_onion")
		if !exists {
			fmt.Printf("you don't seem to have a contact named %v\n", os.Args[2])
		}

		processData := func(onion string, data []byte) []byte {
			return nil
		}

		peer.SetPeerDataHandler(processData)

		fmt.Printf("connecting to %v...\n", os.Args[2])
		connection := peer.PeerWithOnion(onion)

		fmt.Printf("sending data...\n")
		reader := bufio.NewReader(os.Stdin)
		packet := make([]byte, 65531)
		br, _ := reader.Read(packet)
		if br > 65530 {
			fmt.Printf("sorry but i can't send more than 65530 bytes at once right now :( errorinn is working on it!\n")
			os.Exit(1)
		}
		connection.SendPacket(packet[:br])
	case "receive":
		if len(os.Args) != 3 {
			fmt.Fprintf(os.Stderr, "example: sendafriend receive bob > file.txt\n")
			os.Exit(1)
		}

		verifyOnion, exists := peer.GetProfile().GetCustomAttribute(os.Args[2] + "_onion")
		if !exists {
			fmt.Fprintf(os.Stderr, "hmm you don't have a contact named %v\n", os.Args[2])
			os.Exit(1)
		}

		processData := func(onion string, data []byte) []byte {
			if onion != verifyOnion {
				fmt.Fprintf(os.Stderr, "woah, got some unauthenticated data. discarding it!\n")
				os.Exit(1)
			}

			fmt.Printf("%s", data)
			os.Exit(0)
			return nil
		}

		peer.SetPeerDataHandler(processData)
		fmt.Fprintf(os.Stderr, "waiting for %v to send...\n", os.Args[2])
		err = peer.Listen()
		if err != nil {
			fmt.Printf("error listening for connections: %v\n", err)
		}
	case "hide":
		if len(os.Args) != 3 {
			fmt.Fprintf(os.Stderr, "example: sendafriend hide bob\n")
			os.Exit(1)
		}

		suggestedSecret, _ := diceware.Generate(2)
		fmt.Printf("enter a secret that only the two of you would know [%v %v]: ", suggestedSecret[0], suggestedSecret[1])
		in := bufio.NewReader(os.Stdin)
		secret, _ := in.ReadString('\n')
		secret = secret[:len(secret)-1]

		if secret == "" {
			secret = strings.Join(suggestedSecret, " ")
		}

		fmt.Println("okay, now please wait a moment while some magic happens...")
		ephemeralPeer, err := libpeer.NewCwtchPeer("Alice", "alicepass", "")
		if err != nil {
			fmt.Printf("couldn't create an ephemeral onion address: %v\n", err)
			os.Exit(1)
		}

		groupId, err := ephemeralPeer.ImportGroup(inviteStr)
		if err != nil {
			fmt.Printf("couldn't configure the bbs settings: %v\n", err)
			os.Exit(1)
		}

		group := ephemeralPeer.GetGroup(groupId)
		ephemeralPeer.JoinServer(group.GroupServer)
		mp := ephemeralPeer.GetServers()
		for ; mp[group.GroupServer] != connections.AUTHENTICATED; mp = ephemeralPeer.GetServers() {
			time.Sleep(time.Millisecond * 500)
		}

		err = ephemeralPeer.SendMessageToGroup(groupId, "be gay do crimes")
		if err != nil {
			fmt.Printf("the hide-n-seek server is down or something? try again i guess; %v\n", err)
			os.Exit(1)
		}

		convos := make(map[string]*Conversation)
		processData := func(onion string, data []byte) []byte {
			if _, contains := convos[onion]; !contains {
				convos[onion] = new(Conversation)
				secretInt := new(big.Int)
				secretInt.SetBytes([]byte(secret))
				convos[onion].smp.secret = secretInt
			}

			tlvPacket := arr2tlv(data)
			if tlvPacket.typ == 42 {
				fmt.Printf("you've been found! adding %v <%s> to contact list\n", os.Args[2], tlvPacket.data)
				addContactEntry(peer, os.Args[2], string(tlvPacket.data))
				peer.Save()
				finalPacket := tlv{42, uint16(len(peer.GetProfile().Onion)), []byte(peer.GetProfile().Onion)}
				go driftoff()
				return tlv2arr(finalPacket)
			}

			out, _, _ := convos[onion].processSMP(tlvPacket)
			return tlv2arr(out)
		}
		ephemeralPeer.SetPeerDataHandler(processData)
		go ephemeralPeer.Listen()
		exitOnEnter()
	case "seek":
		if len(os.Args) != 3 {
			fmt.Fprintf(os.Stderr, "example: sendafriend seek alice\n")
			os.Exit(1)
		}

		fmt.Print("enter a secret that only the two of you would know: ")
		in := bufio.NewReader(os.Stdin)
		secret, _ := in.ReadString('\n')
		secret = secret[:len(secret)-1]
		fmt.Println("okay, now please wait a moment while some magic happens...")

		ephemeralPeer, err := libpeer.NewCwtchPeer("Alice", "alicepass", "")
		if err != nil {
			fmt.Printf("couldn't create an ephemeral onion address: %v\n", err)
			os.Exit(1)
		}

		groupId, err := ephemeralPeer.ImportGroup(inviteStr)
		if err != nil {
			fmt.Printf("couldn't configure the bbs settings: %v\n", err)
			os.Exit(1)
		}

		group := ephemeralPeer.GetGroup(groupId)
		ephemeralPeer.JoinServer(group.GroupServer)

		//sadly we cannot listen for messages normally because we want to go in reverse order
		messages := group.GetTimeline()
		for ; len(messages) == 0; messages = group.GetTimeline() {
			time.Sleep(time.Second * 3)
		}

		var waitGroup sync.WaitGroup
		fmt.Printf("got advertisements. checking them...")
		for i := len(messages) - 1; i >= 0; i-- {
			if messages[i].Message == "be gay do crimes" {
				// this is not as scary as it seems because only one of these goroutines will actually use the peer
				waitGroup.Add(1)
				go doSMP(peer, messages[i].PeerID, secret, os.Args[2])
			}
		}
		waitGroup.Wait()
	}

	peer.Save()
}