Fixed DMs

internal/database.go

@@ -48,7 +48,6 @@ func InitDB() {
         FOREIGN KEY (room_id) REFERENCES rooms(id),
         FOREIGN KEY (username) REFERENCES users(username)
     );
-    -- Stores the encrypted room key for a specific user for a specific epoch
     CREATE TABLE IF NOT EXISTS user_room_keys (
         username TEXT,
         room_id TEXT,
@@ -132,6 +131,12 @@ func getRoomIDByName(name string) (string, error) {
 	return id, err
 }
 
+func getRoomCreator(roomID string) (string, error) {
+	var creator string
+	err := db.QueryRow("SELECT creator FROM rooms WHERE id = ?", roomID).Scan(&creator)
+	return creator, err
+}
+
 func getRoomCurrentEpoch(roomID string) (int, error) {
 	var epoch int
 	err := db.QueryRow("SELECT current_epoch FROM rooms WHERE id = ?", roomID).Scan(&epoch)
@@ -140,7 +145,6 @@ func getRoomCurrentEpoch(roomID string) (int, error) {
 
 func incrementRoomEpoch(roomID string) (int, error) {
 	var newEpoch int
-	// Atomic increment
 	err := db.QueryRow("UPDATE rooms SET current_epoch = current_epoch + 1 WHERE id = ? RETURNING current_epoch", roomID).Scan(&newEpoch)
 	return newEpoch, err
 }
@@ -175,7 +179,6 @@ func leaveRoom(roomID, username string) error {
 }
 
 func joinRoomMember(roomID, username string) error {
-	// Check if already joined
 	var count int
 	db.QueryRow("SELECT COUNT(*) FROM room_members WHERE room_id = ? AND username = ?", roomID, username).Scan(&count)
 	if count > 0 {

internal/model.go

@@ -51,7 +51,6 @@ type model struct {
 
 	currentRoomID    string
 	currentRoomEpoch int
-	// We cache keys: Epoch -> Plaintext Key
 	roomKeyCache     map[int][]byte
 
 	rooms []struct {
@@ -143,6 +142,11 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		return m, tea.ClearScreen
 
 	case tea.KeyMsg:
+		// Clear any displayed errors on user interaction
+		if m.err != nil {
+			m.err = nil
+		}
+
 		switch msg.Type {
 		case tea.KeyCtrlC, tea.KeyEsc:
 			return m, tea.Quit
@@ -226,23 +230,21 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 					}
 
 					if val == "/leave" {
+						creator, _ := getRoomCreator(m.currentRoomID)
+						if creator == m.username {
+							m.saveMessage("System", "Error: Owners cannot leave. Use /delete to destroy room.")
+							m.input.Reset()
+							return m, nil
+						}
 						leaveRoom(m.currentRoomID, m.username)
-						m.rotateRoomKey(m.currentRoomID) // Rotate key on leave
+						m.rotateRoomKey(m.currentRoomID)
 						m.exitChat()
 						return m, tea.ClearScreen
 					}
 
 					if val == "/delete" {
-						isCreator := false
+						creator, _ := getRoomCreator(m.currentRoomID)
-						for _, r := range m.rooms {
+						if creator == m.username {
-							if r.ID == m.currentRoomID {
-								if r.Creator == m.username {
-									isCreator = true
-								}
-								break
-							}
-						}
-						if isCreator {
 							deleteRoom(m.currentRoomID)
 							m.exitChat()
 							return m, tea.ClearScreen
@@ -289,15 +291,10 @@ func (m *model) loadRooms() {
 	m.rooms = rooms
 	m.viewport.SetContent("")
 	m.input.SetValue("")
-	m.input.Placeholder = "Enter room # or: /join <name>, /dm <username>, /list"
+	m.input.Placeholder = "Enter room # or: /join <name>, /dm <username>"
 }
 
 func (m *model) handleRoomListInput(text string) {
-	if text == "/list" {
-		m.loadRooms()
-		return
-	}
-
 	if strings.HasPrefix(text, "/join ") {
 		roomName := strings.TrimPrefix(text, "/join ")
 		m.handleJoinRoom(roomName)
@@ -324,18 +321,15 @@ func (m *model) handleRoomListInput(text string) {
 func (m *model) handleJoinRoom(roomName string) {
 	existingID, err := getRoomIDByName(roomName)
 	if err == nil && existingID != "" {
-		// Join existing
 		if err := joinRoomMember(existingID, m.username); err != nil {
 			m.err = err
 			return
 		}
-		// ROTATE KEY so new user gets a key, but doesn't get old keys
 		m.rotateRoomKey(existingID)
 		m.enterRoom(existingID, roomName)
 		return
 	}
 
-	// Create new
 	roomID := generateRoomID()
 	if err := createRoom(roomID, roomName, m.username, false); err != nil {
 		m.err = err
@@ -345,7 +339,6 @@ func (m *model) handleJoinRoom(roomName string) {
 		m.err = err
 		return
 	}
-	// Initial Key
 	m.rotateRoomKey(roomID)
 	m.enterRoom(roomID, roomName)
 }
@@ -382,7 +375,7 @@ func (m *model) rotateRoomKey(roomID string) {
 func (m *model) handleSelectUserForDM(username string) {
 	if username == "/cancel" {
 		m.state = 1
-		m.input.Placeholder = "Enter room # or: /join <name>, /dm <username>, /list"
+		m.input.Placeholder = "Enter room # or: /join <name>, /dm <username>"
 		return
 	}
 	if username == m.username {
@@ -390,6 +383,40 @@ func (m *model) handleSelectUserForDM(username string) {
 		return
 	}
 
+	// CHECK IF USER EXISTS
+	identityKey, prekey, prekeySignature, err := getUserKeys(username)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			m.err = fmt.Errorf("user '%s' not found", username)
+		} else {
+			m.err = err
+		}
+		return
+	}
+
+	if len(identityKey) == 0 {
+		m.err = fmt.Errorf("user '%s' has no keys set up", username)
+		return
+	}
+
+	// Pre-calc shared secret for DM
+	var theirIdentityKey, theirPrekey [32]byte
+	copy(theirIdentityKey[:], identityKey)
+	copy(theirPrekey[:], prekey)
+
+	ephemeralKey, err := generateIdentityKeyPair()
+	if err != nil {
+		m.err = err
+		return
+	}
+
+	dh1, _ := performDH(m.identityKey.PrivateKey, theirPrekey)
+	dh2, _ := performDH(ephemeralKey.PrivateKey, theirIdentityKey)
+	dh3, _ := performDH(ephemeralKey.PrivateKey, theirPrekey)
+
+	_ = deriveSharedSecret(dh1, dh2, dh3)
+	_ = prekeySignature
+
 	roomID := generateRoomID()
 	roomName := fmt.Sprintf("DM: %s <-> %s", m.username, username)
 
@@ -418,10 +445,17 @@ func (m *model) createNoteToSelf() {
 
 func (m *model) enterRoom(roomID, roomName string) {
 	epoch, _ := getRoomCurrentEpoch(roomID)
+	creator, _ := getRoomCreator(roomID)
+
 	m.currentRoomID = roomID
 	m.currentRoomEpoch = epoch
 	m.state = 2
-	m.input.Placeholder = fmt.Sprintf("[%s] /back, /leave, /delete", roomName)
+
+	if creator == m.username {
+		m.input.Placeholder = fmt.Sprintf("[%s] /back to menu, /delete to destroy", roomName)
+	} else {
+		m.input.Placeholder = fmt.Sprintf("[%s] /back to menu, /leave to quit", roomName)
+	}
 	m.loadMessages()
 }
 
@@ -442,28 +476,23 @@ func generateRoomID() string {
 }
 
 func (m *model) getEpochKey(epoch int) []byte {
-	// Check cache
 	if key, ok := m.roomKeyCache[epoch]; ok {
 		return key
 	}
-
 	encKey, err := getUserRoomKey(m.username, m.currentRoomID, epoch)
 	if err != nil || encKey == nil {
 		return nil
 	}
-
 	key, err := DecryptKeyForUser(m.identityKey.PrivateKey, encKey)
 	if err != nil {
 		return nil
 	}
-
 	m.roomKeyCache[epoch] = key
 	return key
 }
 
 func (m *model) saveMessage(sender, text string) {
 	m.currentRoomEpoch, _ = getRoomCurrentEpoch(m.currentRoomID)
-
 	key := m.getEpochKey(m.currentRoomEpoch)
 	if key == nil {
 		m.err = fmt.Errorf("no key for current epoch")
@@ -555,29 +584,38 @@ No public key authentication provided.
 	}
 
 	if m.needsRegistration {
+		errStr := ""
+		if m.err != nil {
+			errStr = "\n" + errStyle.Render(m.err.Error()) + "\n"
+		}
 		return fmt.Sprintf(`
 %s
 Welcome! You're a new user.
 Please choose a username to register.
-
 %s
-`, sysStyle.Render("SECURE TUI CHAT - REGISTRATION"), m.input.View())
+%s
+`, sysStyle.Render("SECURE TUI CHAT - REGISTRATION"), errStr, m.input.View())
 	}
 
 	if m.state == 0 {
+		errStr := ""
+		if m.err != nil {
+			errStr = "\n" + errStyle.Render(m.err.Error()) + "\n"
+		}
 		return fmt.Sprintf(`
 %s
 Welcome back, %s.
 This environment is encrypted at rest.
 Please enter your passphrase to unlock your keys.
-
 %s
-`, sysStyle.Render("SECURE TUI CHAT"), senderStyle.Render(m.username), m.input.View())
+%s
+`, sysStyle.Render("SECURE TUI CHAT"), senderStyle.Render(m.username), errStr, m.input.View())
 	}
 
 	if m.state == 1 {
 		var b strings.Builder
 		b.WriteString(sysStyle.Render("=== YOUR ROOMS ===") + "\n\n")
+
 		if len(m.rooms) == 0 {
 			b.WriteString(sysStyle.Render("No rooms yet.") + "\n")
 			b.WriteString(commandStyle.Render("  /join <name>") + " - Join/Create room\n")
@@ -601,7 +639,11 @@ Please enter your passphrase to unlock your keys.
 					prefix,
 					style.Render(room.Name)))
 			}
-			b.WriteString("\n" + sysStyle.Render("Commands: ") + commandStyle.Render("/join /dm /list") + "\n")
+			b.WriteString("\n" + sysStyle.Render("Commands: ") + commandStyle.Render("/join /dm") + "\n")
+		}
+
+		if m.err != nil {
+			b.WriteString("\n" + errStyle.Render(m.err.Error()))
 		}
 		b.WriteString("\n" + m.input.View())
 		return b.String()