Merge branch 'e2ee'

6 files changed, 265 insertions, 41 deletions

diff --git a/matrix/crypto.go b/matrix/crypto.go
new file mode 100644
index 0000000..8eab355
--- /dev/null
+++ b/matrix/crypto.go
@@ -0,0 +1,62 @@
+// gomuks - A terminal Matrix client written in Go.
+// Copyright (C) 2020 Tulir Asokan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program 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 Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+// +build cgo
+
+package matrix
+
+import (
+	"path/filepath"
+
+	"maunium.net/go/mautrix/crypto"
+
+	"maunium.net/go/gomuks/debug"
+)
+
+type cryptoLogger struct{}
+
+func (c cryptoLogger) Error(message string, args ...interface{}) {
+	debug.Printf("[Crypto/Error] "+message, args...)
+}
+
+func (c cryptoLogger) Warn(message string, args ...interface{}) {
+	debug.Printf("[Crypto/Warn] "+message, args...)
+}
+
+func (c cryptoLogger) Debug(message string, args ...interface{}) {
+	debug.Printf("[Crypto/Debug] "+message, args...)
+}
+
+func (c cryptoLogger) Trace(message string, args ...interface{}) {
+	debug.Printf("[Crypto/Trace] "+message, args...)
+}
+
+func isBadEncryptError(err error) bool {
+	return err != crypto.SessionExpired && err != crypto.SessionNotShared && err != crypto.NoGroupSession
+}
+
+func (c *Container) initCrypto() error {
+	cryptoStore, err := crypto.NewGobStore(filepath.Join(c.config.DataDir, "crypto.gob"))
+	if err != nil {
+		return err
+	}
+	c.crypto = crypto.NewOlmMachine(c.client, cryptoLogger{}, cryptoStore, c.config.Rooms)
+	err = c.crypto.Load()
+	if err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/matrix/matrix.go b/matrix/matrix.go
index d0fd2f4..30e28fb 100644
--- a/matrix/matrix.go
+++ b/matrix/matrix.go
@@ -17,7 +17,6 @@
 package matrix
 
 import (
-	"bytes"
 	"context"
 	"crypto/tls"
 	"encoding/gob"
@@ -37,6 +36,7 @@ import (
 	"github.com/pkg/errors"
 
 	"maunium.net/go/mautrix"
+	"maunium.net/go/mautrix/crypto/attachment"
 	"maunium.net/go/mautrix/event"
 	"maunium.net/go/mautrix/format"
 	"maunium.net/go/mautrix/id"
@@ -55,6 +55,7 @@ import (
 // It is used for all Matrix calls from the UI and Matrix event handlers.
 type Container struct {
 	client  *mautrix.Client
+	crypto  CryptoInterface
 	syncer  *GomuksSyncer
 	gmx     ifc.Gomuks
 	ui      ifc.GomuksUI
@@ -88,6 +89,16 @@ func (log mxLogger) Debugfln(message string, args ...interface{}) {
 	debug.Printf("[Matrix] "+message, args...)
 }
 
+type CryptoInterface interface {
+	Load() error
+	FlushStore() error
+	ProcessSyncResponse(resp *mautrix.RespSync, since string)
+	HandleMemberEvent(*event.Event)
+	DecryptMegolmEvent(*event.Event) (*event.Event, error)
+	EncryptMegolmEvent(id.RoomID, event.Type, event.Content) (*event.EncryptedEventContent, error)
+	ShareGroupSession(id.RoomID, []id.UserID) error
+}
+
 // InitClient initializes the mautrix client and connects to the homeserver specified in the config.
 func (c *Container) InitClient() error {
 	if len(c.config.HS) == 0 {
@@ -97,6 +108,7 @@ func (c *Container) InitClient() error {
 	if c.client != nil {
 		c.Stop()
 		c.client = nil
+		c.crypto = nil
 	}
 
 	var mxid id.UserID
@@ -112,6 +124,12 @@ func (c *Container) InitClient() error {
 		return err
 	}
 	c.client.Logger = mxLogger{}
+	c.client.DeviceID = c.config.DeviceID
+
+	err = c.initCrypto()
+	if err != nil {
+		return err
+	}
 
 	if c.history == nil {
 		c.history, err = NewHistoryManager(c.config.HistoryPath)
@@ -159,7 +177,9 @@ func (c *Container) PasswordLogin(user, password string) error {
 
 func (c *Container) finishLogin(resp *mautrix.RespLogin) {
 	c.client.SetCredentials(resp.UserID, resp.AccessToken)
+	c.client.DeviceID = resp.DeviceID
 	c.config.UserID = resp.UserID
+	c.config.DeviceID = resp.DeviceID
 	c.config.AccessToken = resp.AccessToken
 	c.config.Save()
 
@@ -247,9 +267,10 @@ func (c *Container) Login(user, password string) error {
 // Logout revokes the access token, stops the syncer and calls the OnLogout() method of the UI.
 func (c *Container) Logout() {
 	c.client.Logout()
-	c.config.DeleteSession()
 	c.Stop()
+	c.config.DeleteSession()
 	c.client = nil
+	c.crypto = nil
 	c.ui.OnLogout()
 }
 
@@ -265,6 +286,13 @@ func (c *Container) Stop() {
 			debug.Print("Error closing history manager:", err)
 		}
 		c.history = nil
+		if c.crypto != nil {
+			debug.Print("Flushing crypto store")
+			err = c.crypto.FlushStore()
+			if err != nil {
+				debug.Print("Error flushing crypto store:", err)
+			}
+		}
 	}
 }
 
@@ -315,8 +343,20 @@ func (c *Container) OnLogin() {
 
 	debug.Print("Initializing syncer")
 	c.syncer = NewGomuksSyncer(c.config.Rooms)
+	if c.crypto != nil {
+		c.syncer.OnSync(c.crypto.ProcessSyncResponse)
+		c.syncer.OnEventType(event.StateMember, func(source EventSource, evt *event.Event) {
+			// Don't spam the crypto module with member events of an initial sync
+			// TODO invalidate all group sessions when clearing cache?
+			if c.config.AuthCache.InitialSyncDone {
+				c.crypto.HandleMemberEvent(evt)
+			}
+		})
+		c.syncer.OnEventType(event.EventEncrypted, c.HandleEncrypted)
+	} else {
+		c.syncer.OnEventType(event.EventEncrypted, c.HandleMessage)
+	}
 	c.syncer.OnEventType(event.EventMessage, c.HandleMessage)
-	c.syncer.OnEventType(event.EventEncrypted, c.HandleMessage)
 	c.syncer.OnEventType(event.EventSticker, c.HandleMessage)
 	c.syncer.OnEventType(event.EventReaction, c.HandleMessage)
 	c.syncer.OnEventType(event.EventRedaction, c.HandleRedaction)
@@ -516,6 +556,17 @@ func (c *Container) HandleReaction(room *rooms.Room, reactsTo id.EventID, reactE
 	}
 }
 
+func (c *Container) HandleEncrypted(source EventSource, mxEvent *event.Event) {
+	evt, err := c.crypto.DecryptMegolmEvent(mxEvent)
+	if err != nil {
+		debug.Print("Failed to decrypt event:", err)
+		// TODO add decryption failed message instead of passing through directly
+		c.HandleMessage(source, mxEvent)
+		return
+	}
+	c.HandleMessage(source, evt)
+}
+
 // HandleMessage is the event handler for the m.room.message timeline event.
 func (c *Container) HandleMessage(source EventSource, mxEvent *event.Event) {
 	room := c.GetOrCreateRoom(mxEvent.RoomID)
@@ -526,13 +577,16 @@ func (c *Container) HandleMessage(source EventSource, mxEvent *event.Event) {
 		return
 	}
 
-	rel := mxEvent.Content.AsMessage().GetRelatesTo()
-	if editID := rel.GetReplaceID(); len(editID) > 0 {
-		c.HandleEdit(room, editID, muksevt.Wrap(mxEvent))
-		return
-	} else if reactionID := rel.GetAnnotationID(); mxEvent.Type == event.EventReaction && len(reactionID) > 0 {
-		c.HandleReaction(room, reactionID, muksevt.Wrap(mxEvent))
-		return
+	relatable, ok := mxEvent.Content.Parsed.(event.Relatable)
+	if ok {
+		rel := relatable.GetRelatesTo()
+		if editID := rel.GetReplaceID(); len(editID) > 0 {
+			c.HandleEdit(room, editID, muksevt.Wrap(mxEvent))
+			return
+		} else if reactionID := rel.GetAnnotationID(); mxEvent.Type == event.EventReaction && len(reactionID) > 0 {
+			c.HandleReaction(room, reactionID, muksevt.Wrap(mxEvent))
+			return
+		}
 	}
 
 	events, err := c.history.Append(room, []*event.Event{mxEvent})
@@ -824,8 +878,28 @@ func (c *Container) Redact(roomID id.RoomID, eventID id.EventID, reason string)
 func (c *Container) SendEvent(evt *muksevt.Event) (id.EventID, error) {
 	defer debug.Recover()
 
-	c.client.UserTyping(evt.RoomID, false, 0)
+	_, _ = c.client.UserTyping(evt.RoomID, false, 0)
 	c.typing = 0
+	room := c.GetRoom(evt.RoomID)
+	if room != nil && room.Encrypted && c.crypto != nil && evt.Type != event.EventReaction {
+		encrypted, err := c.crypto.EncryptMegolmEvent(evt.RoomID, evt.Type, evt.Content)
+		if err != nil {
+			if isBadEncryptError(err) {
+				return "", err
+			}
+			debug.Print("Got", err, "while trying to encrypt message, sharing group session and trying again...")
+			err = c.crypto.ShareGroupSession(room.ID, room.GetMemberList())
+			if err != nil {
+				return "", err
+			}
+			encrypted, err = c.crypto.EncryptMegolmEvent(evt.RoomID, evt.Type, evt.Content)
+			if err != nil {
+				return "", err
+			}
+		}
+		evt.Type = event.EventEncrypted
+		evt.Content = event.Content{Parsed: encrypted}
+	}
 	resp, err := c.client.SendMessageEvent(evt.RoomID, evt.Type, &evt.Content, mautrix.ReqSendEvent{TransactionID: evt.Unsigned.TransactionID})
 	if err != nil {
 		return "", err
@@ -923,11 +997,21 @@ func (c *Container) GetHistory(room *rooms.Room, limit int) ([]*muksevt.Event, e
 		return nil, err
 	}
 	debug.Printf("Loaded %d events for %s from server from %s to %s", len(resp.Chunk), room.ID, resp.Start, resp.End)
-	for _, evt := range resp.Chunk {
+	for i, evt := range resp.Chunk {
 		err := evt.Content.ParseRaw(evt.Type)
 		if err != nil {
 			debug.Printf("Failed to unmarshal content of event %s (type %s) by %s in %s: %v\n%s", evt.ID, evt.Type.Repr(), evt.Sender, evt.RoomID, err, string(evt.Content.VeryRaw))
 		}
+
+		if c.crypto != nil && evt.Type == event.EventEncrypted {
+			decrypted, err := c.crypto.DecryptMegolmEvent(evt)
+			if err != nil {
+				debug.Print("Failed to decrypt event:", err)
+				// TODO add decryption failed message instead of passing through directly
+			} else {
+				resp.Chunk[i] = decrypted
+			}
+		}
 	}
 	for _, evt := range resp.State {
 		room.UpdateState(evt)
@@ -991,7 +1075,7 @@ func cp(src, dst string) error {
 	return out.Close()
 }
 
-func (c *Container) DownloadToDisk(uri id.ContentURI, target string) (fullPath string, err error) {
+func (c *Container) DownloadToDisk(uri id.ContentURI, file *attachment.EncryptedFile, target string) (fullPath string, err error) {
 	cachePath := c.GetCachePath(uri)
 	if target == "" {
 		fullPath = cachePath
@@ -1002,21 +1086,27 @@ func (c *Container) DownloadToDisk(uri id.ContentURI, target string) (fullPath s
 	}
 
 	if _, statErr := os.Stat(cachePath); os.IsNotExist(statErr) {
-		var file *os.File
-		file, err = os.OpenFile(cachePath, os.O_CREATE|os.O_WRONLY, 0600)
+		var body io.ReadCloser
+		body, err = c.client.Download(uri)
 		if err != nil {
 			return
 		}
-		defer file.Close()
 
-		var body io.ReadCloser
-		body, err = c.client.Download(uri)
+		var data []byte
+		data, err = ioutil.ReadAll(body)
+		_ = body.Close()
 		if err != nil {
 			return
 		}
-		defer body.Close()
 
-		_, err = io.Copy(file, body)
+		if file != nil {
+			data, err = file.Decrypt(data)
+			if err != nil {
+				return
+			}
+		}
+
+		err = ioutil.WriteFile(cachePath, data, 0600)
 		if err != nil {
 			return
 		}
@@ -1036,7 +1126,7 @@ func (c *Container) DownloadToDisk(uri id.ContentURI, target string) (fullPath s
 // Download fetches the given Matrix content (mxc) URL and returns the data, homeserver, file ID and potential errors.
 //
 // The file will be either read from the media cache (if found) or downloaded from the server.
-func (c *Container) Download(uri id.ContentURI) (data []byte, err error) {
+func (c *Container) Download(uri id.ContentURI, file *attachment.EncryptedFile) (data []byte, err error) {
 	cacheFile := c.GetCachePath(uri)
 	var info os.FileInfo
 	if info, err = os.Stat(cacheFile); err == nil && !info.IsDir() {
@@ -1046,7 +1136,7 @@ func (c *Container) Download(uri id.ContentURI) (data []byte, err error) {
 		}
 	}
 
-	data, err = c.download(uri, cacheFile)
+	data, err = c.download(uri, file, cacheFile)
 	return
 }
 
@@ -1054,21 +1144,25 @@ func (c *Container) GetDownloadURL(uri id.ContentURI) string {
 	return c.client.GetDownloadURL(uri)
 }
 
-func (c *Container) download(uri id.ContentURI, cacheFile string) (data []byte, err error) {
+func (c *Container) download(uri id.ContentURI, file *attachment.EncryptedFile, cacheFile string) (data []byte, err error) {
 	var body io.ReadCloser
 	body, err = c.client.Download(uri)
 	if err != nil {
 		return
 	}
-	defer body.Close()
 
-	var buf bytes.Buffer
-	_, err = io.Copy(&buf, body)
+	data, err = ioutil.ReadAll(body)
+	_ = body.Close()
 	if err != nil {
 		return
 	}
 
-	data = buf.Bytes()
+	if file != nil {
+		data, err = file.Decrypt(data)
+		if err != nil {
+			return
+		}
+	}
 
 	err = ioutil.WriteFile(cacheFile, data, 0600)
 	return
diff --git a/matrix/nocrypto.go b/matrix/nocrypto.go
new file mode 100644
index 0000000..979afda
--- /dev/null
+++ b/matrix/nocrypto.go
@@ -0,0 +1,13 @@
+// This contains no-op stubs of the methods in crypto.go for non-cgo builds with crypto disabled.
+
+// +build !cgo
+
+package matrix
+
+func isBadEncryptError(err error) bool {
+	return false
+}
+
+func (c *Container) initCrypto() error {
+	return nil
+}
diff --git a/matrix/rooms/room.go b/matrix/rooms/room.go
index 0238cfb..d5d1d8f 100644
--- a/matrix/rooms/room.go
+++ b/matrix/rooms/room.go
@@ -412,7 +412,7 @@ func (room *Room) UpdateState(evt *event.Event) {
 	case *event.TopicEventContent:
 		room.topicCache = content.Topic
 	case *event.EncryptionEventContent:
-		if content.Algorithm == event.AlgorithmMegolmV1 {
+		if content.Algorithm == id.AlgorithmMegolmV1 {
 			room.Encrypted = true
 		}
 	}
@@ -650,6 +650,17 @@ func (room *Room) GetMembers() map[id.UserID]*Member {
 	return room.memberCache
 }
 
+func (room *Room) GetMemberList() []id.UserID {
+	members := room.GetMembers()
+	memberList := make([]id.UserID, len(members))
+	index := 0
+	for userID, _ := range members {
+		memberList[index] = userID
+		index++
+	}
+	return memberList
+}
+
 // GetMember returns the member with the given MXID.
 // If the member doesn't exist, nil is returned.
 func (room *Room) GetMember(userID id.UserID) *Member {
diff --git a/matrix/rooms/roomcache.go b/matrix/rooms/roomcache.go
index ffdcad1..067cbb6 100644
--- a/matrix/rooms/roomcache.go
+++ b/matrix/rooms/roomcache.go
@@ -27,6 +27,7 @@ import (
 	sync "github.com/sasha-s/go-deadlock"
 
 	"maunium.net/go/gomuks/debug"
+	"maunium.net/go/mautrix/event"
 	"maunium.net/go/mautrix/id"
 )
 
@@ -67,6 +68,29 @@ func (cache *RoomCache) EnableUnloading() {
 	cache.noUnload = false
 }
 
+func (cache *RoomCache) IsEncrypted(roomID id.RoomID) bool {
+	room := cache.Get(roomID)
+	return room != nil && room.Encrypted
+}
+
+func (cache *RoomCache) FindSharedRooms(userID id.UserID) (shared []id.RoomID) {
+	// FIXME this disables unloading so TouchNode wouldn't try to double-lock
+	cache.DisableUnloading()
+	cache.Lock()
+	for _, room := range cache.Map {
+		if !room.Encrypted {
+			continue
+		}
+		member, ok := room.GetMembers()[userID]
+		if ok && member.Membership == event.MembershipJoin {
+			shared = append(shared, room.ID)
+		}
+	}
+	cache.Unlock()
+	cache.EnableUnloading()
+	return
+}
+
 func (cache *RoomCache) LoadList() error {
 	cache.Lock()
 	defer cache.Unlock()
diff --git a/matrix/sync.go b/matrix/sync.go
index 85de68c..2136088 100644
--- a/matrix/sync.go
+++ b/matrix/sync.go
@@ -83,9 +83,11 @@ func (es EventSource) String() string {
 }
 
 type EventHandler func(source EventSource, event *event.Event)
+type SyncHandler func(resp *mautrix.RespSync, since string)
 
 type GomuksSyncer struct {
 	rooms             *rooms.RoomCache
+	globalListeners   []SyncHandler
 	listeners         map[event.Type][]EventHandler // event type to listeners array
 	FirstSyncDone     bool
 	InitDoneCallback  func()
@@ -96,10 +98,11 @@ type GomuksSyncer struct {
 // NewGomuksSyncer returns an instantiated GomuksSyncer
 func NewGomuksSyncer(rooms *rooms.RoomCache) *GomuksSyncer {
 	return &GomuksSyncer{
-		rooms:         rooms,
-		listeners:     make(map[event.Type][]EventHandler),
-		FirstSyncDone: false,
-		Progress:      StubSyncingModal{},
+		rooms:           rooms,
+		globalListeners: []SyncHandler{},
+		listeners:       make(map[event.Type][]EventHandler),
+		FirstSyncDone:   false,
+		Progress:        StubSyncingModal{},
 	}
 }
 
@@ -109,23 +112,26 @@ func (s *GomuksSyncer) ProcessResponse(res *mautrix.RespSync, since string) (err
 		s.rooms.DisableUnloading()
 	}
 	debug.Print("Received sync response")
+	s.Progress.SetMessage("Processing sync response")
 	steps := len(res.Rooms.Join) + len(res.Rooms.Invite) + len(res.Rooms.Leave)
-	s.Progress.SetSteps(steps + 2)
-	s.Progress.SetMessage("Processing global events")
-	s.processSyncEvents(nil, res.Presence.Events, EventSourcePresence)
-	s.Progress.Step()
-	s.processSyncEvents(nil, res.AccountData.Events, EventSourceAccountData)
-	s.Progress.Step()
+	s.Progress.SetSteps(steps + 2 + len(s.globalListeners))
 
 	wait := &sync.WaitGroup{}
-
-	wait.Add(steps)
 	callback := func() {
 		wait.Done()
 		s.Progress.Step()
 	}
+	wait.Add(len(s.globalListeners))
+	s.notifyGlobalListeners(res, since, callback)
+	wait.Wait()
+
+	s.processSyncEvents(nil, res.Presence.Events, EventSourcePresence)
+	s.Progress.Step()
+	s.processSyncEvents(nil, res.AccountData.Events, EventSourceAccountData)
+	s.Progress.Step()
+
+	wait.Add(steps)
 
-	s.Progress.SetMessage("Processing room events")
 	for roomID, roomData := range res.Rooms.Join {
 		go s.processJoinedRoom(roomID, roomData, callback)
 	}
@@ -152,6 +158,15 @@ func (s *GomuksSyncer) ProcessResponse(res *mautrix.RespSync, since string) (err
 	return
 }
 
+func (s *GomuksSyncer) notifyGlobalListeners(res *mautrix.RespSync, since string, callback func()) {
+	for _, listener := range s.globalListeners {
+		go func(listener SyncHandler) {
+			listener(res, since)
+			callback()
+		}(listener)
+	}
+}
+
 func (s *GomuksSyncer) processJoinedRoom(roomID id.RoomID, roomData mautrix.SyncJoinedRoom, callback func()) {
 	defer debug.Recover()
 	room := s.rooms.GetOrCreate(roomID)
@@ -239,6 +254,10 @@ func (s *GomuksSyncer) OnEventType(eventType event.Type, callback EventHandler)
 	s.listeners[eventType] = append(s.listeners[eventType], callback)
 }
 
+func (s *GomuksSyncer) OnSync(callback SyncHandler) {
+	s.globalListeners = append(s.globalListeners, callback)
+}
+
 func (s *GomuksSyncer) notifyListeners(source EventSource, evt *event.Event) {
 	listeners, exists := s.listeners[evt.Type]
 	if !exists {
@@ -269,6 +288,7 @@ func (s *GomuksSyncer) GetFilterJSON(_ id.UserID) *mautrix.Filter {
 					event.StateCanonicalAlias,
 					event.StatePowerLevels,
 					event.StateTombstone,
+					event.StateEncryption,
 				},
 			},
 			Timeline: mautrix.FilterPart{