Tor (#12)

* added tor support

* change text

.gitignore

@@ -1,2 +1,3 @@
 videos/*
 !videos/README.md
+onion.key

config.json

@@ -19,5 +19,12 @@
             "email": "author@somewhere.example"
         },
         "copyright": "Copyright Text"
+    },
+    "tor": {
+        "enable": true,
+        "controller": {
+            "host": "127.0.0.1",
+            "port": 9051
+        }
     }
 }

main.go

@@ -19,7 +19,7 @@ func main() {
 		log.Fatal(err)
 	}
 	addr := fmt.Sprintf("%s:%d", cfg.Server.Host, cfg.Server.Port)
-	log.Printf("Serving at http://%s", addr)
+	log.Printf("Local server: http://%s", addr)
 	err = a.Run()
 	if err != nil {
 		log.Fatal(err)

pkg/app/app.go

@@ -16,6 +16,7 @@ import (
 	"github.com/gorilla/feeds"
 	"github.com/gorilla/mux"
 	"github.com/wybiral/tube/pkg/media"
+	"github.com/wybiral/tube/pkg/onionkey"
 )
 
 // App represents main application.
@@ -24,6 +25,7 @@ type App struct {
 	Library   *media.Library
 	Watcher   *fsnotify.Watcher
 	Templates *template.Template
+	Tor       *tor
 	Listener  net.Listener
 	Router    *mux.Router
 }
@@ -52,6 +54,14 @@ func NewApp(cfg *Config) (*App, error) {
 	a.Listener = ln
 	// Setup Templates
 	a.Templates = template.Must(template.ParseGlob("templates/*"))
+	// Setup Tor
+	if cfg.Tor.Enable {
+		t, err := newTor(cfg.Tor)
+		if err != nil {
+			return nil, err
+		}
+		a.Tor = t
+	}
 	// Setup Router
 	r := mux.NewRouter().StrictSlash(true)
 	r.HandleFunc("/", a.indexHandler).Methods("GET")
@@ -74,6 +84,27 @@ func NewApp(cfg *Config) (*App, error) {
 
 // Run imports the library and starts server.
 func (a *App) Run() error {
+	if a.Tor != nil {
+		var err error
+		cs := a.Config.Server
+		key := a.Tor.OnionKey
+		if key == nil {
+			key, err = onionkey.GenerateKey()
+			if err != nil {
+				return err
+			}
+		}
+		onion, err := key.Onion()
+		if err != nil {
+			return err
+		}
+		onion.Ports[80] = fmt.Sprintf("%s:%d", cs.Host, cs.Port)
+		err = a.Tor.Controller.AddOnion(onion)
+		if err != nil {
+			return err
+		}
+		log.Printf("Onion service: http://%s.onion", onion.ServiceID)
+	}
 	for _, pc := range a.Config.Library {
 		p := &media.Path{
 			Path:   pc.Path,

pkg/app/config.go

@@ -10,6 +10,7 @@ type Config struct {
 	Library []*PathConfig `json:"library"`
 	Server  *ServerConfig `json:"server"`
 	Feed    *FeedConfig   `json:"feed"`
+	Tor     *TorConfig    `json:"tor,omitempty"`
 }
 
 // PathConfig settings for media library path.
@@ -37,6 +38,19 @@ type FeedConfig struct {
 	Copyright string `json:"copyright"`
 }
 
+// TorConfig stores tor configuration.
+type TorConfig struct {
+	Enable     bool                 `json:"enable"`
+	Controller *TorControllerConfig `json:"controller"`
+}
+
+// TorControllerConfig stores tor controller configuration.
+type TorControllerConfig struct {
+	Host     string `json:"host"`
+	Port     int    `json:"port"`
+	Password string `json:"password,omitempty"`
+}
+
 // DefaultConfig returns Config initialized with default values.
 func DefaultConfig() *Config {
 	return &Config{
@@ -53,6 +67,13 @@ func DefaultConfig() *Config {
 		Feed: &FeedConfig{
 			ExternalURL: "http://localhost",
 		},
+		Tor: &TorConfig{
+			Enable: false,
+			Controller: &TorControllerConfig{
+				Host: "127.0.0.1",
+				Port: 9051,
+			},
+		},
 	}
 }
 

pkg/app/tor.go

@@ -0,0 +1,44 @@
+package app
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/wybiral/torgo"
+	"github.com/wybiral/tube/pkg/onionkey"
+)
+
+type tor struct {
+	OnionKey   onionkey.Key
+	Controller *torgo.Controller
+}
+
+func newTor(ct *TorConfig) (*tor, error) {
+	addr := fmt.Sprintf("%s:%d", ct.Controller.Host, ct.Controller.Port)
+	ctrl, err := torgo.NewController(addr)
+	if err != nil {
+		return nil, err
+	}
+	if len(ct.Controller.Password) > 0 {
+		err = ctrl.AuthenticatePassword(ct.Controller.Password)
+	} else {
+		err = ctrl.AuthenticateCookie()
+		if err != nil {
+			err = ctrl.AuthenticateNone()
+		}
+	}
+	if err != nil {
+		return nil, err
+	}
+	key, err := onionkey.ReadFile("onion.key")
+	if os.IsNotExist(err) {
+		key = nil
+	} else if err != nil {
+		return nil, err
+	}
+	t := &tor{
+		Controller: ctrl,
+		OnionKey:   key,
+	}
+	return t, nil
+}

pkg/onionkey/key.go

@@ -0,0 +1,22 @@
+package onionkey
+
+import (
+	"github.com/wybiral/torgo"
+)
+
+// Key is generic interface type for Tor onion keys.
+type Key interface {
+	WriteFile(path string) error
+	Onion() (*torgo.Onion, error)
+	ServiceID() string
+}
+
+// GenerateKey generates a Tor onion key.
+func GenerateKey() (Key, error) {
+	return generateV3()
+}
+
+// ReadFile reads a Tor onion key from file path.
+func ReadFile(path string) (Key, error) {
+	return readV3(path)
+}

pkg/onionkey/v3.go

@@ -0,0 +1,76 @@
+package onionkey
+
+import (
+	"crypto/rand"
+	"encoding/base32"
+	"encoding/base64"
+	"errors"
+	"io/ioutil"
+	"os"
+	"strings"
+
+	"github.com/wybiral/torgo"
+	"golang.org/x/crypto/ed25519"
+	"golang.org/x/crypto/sha3"
+)
+
+type v3Key ed25519.PrivateKey
+
+func generateV3() (v3Key, error) {
+	_, key, err := ed25519.GenerateKey(rand.Reader)
+	return v3Key(key), err
+}
+
+func readV3(path string) (v3Key, error) {
+	raw, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	pk := strings.TrimSpace(string(raw))
+	parts := strings.SplitN(pk, ":", 2)
+	if parts[0] != "v3" {
+		return nil, errors.New("Invalid key type")
+	}
+	seed, err := base64.StdEncoding.DecodeString(parts[1])
+	if err != nil {
+		return nil, err
+	}
+	key := ed25519.NewKeyFromSeed(seed)
+	return v3Key(key), nil
+}
+
+func (k v3Key) Onion() (*torgo.Onion, error) {
+	return torgo.OnionFromEd25519(ed25519.PrivateKey(k))
+}
+
+func (k v3Key) WriteFile(path string) error {
+	seed := ed25519.PrivateKey(k).Seed()
+	b64 := base64.StdEncoding.EncodeToString(seed)
+	f, err := os.Create(path)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	_, err = f.WriteString("v3:" + b64)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (k v3Key) ServiceID() string {
+	// Get ed25519 public key
+	pub := ed25519.PrivateKey(k).Public().(ed25519.PublicKey)
+	// Calculate check digits
+	checkstr := []byte(".onion checksum")
+	checkstr = append(checkstr, pub...)
+	checkstr = append(checkstr, 0x03)
+	checksum := sha3.Sum256(checkstr)
+	checkdigits := checksum[:2]
+	// Calculate service ID
+	combined := pub[:]
+	combined = append(combined, checkdigits...)
+	combined = append(combined, 0x03)
+	serviceID := base32.StdEncoding.EncodeToString(combined)
+	return strings.ToLower(serviceID)
+}