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This commit is contained in:
Atridad Lahiji
2025-12-28 00:55:33 -07:00
parent d1fe671704
commit a046e0eb0e
3 changed files with 256 additions and 162 deletions
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206
internal/model.go
View File

@@ -17,13 +17,13 @@ import (
)
var (
msgStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("252")).PaddingLeft(1)
senderStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("205")).Bold(true)
errStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("196")).Bold(true)
sysStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("117")).Italic(true)
roomStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("86")).Bold(true)
dmStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("141")).Bold(true)
noteStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("228")).Bold(true)
msgStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("252")).PaddingLeft(1)
senderStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("205")).Bold(true)
errStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("196")).Bold(true)
sysStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("117")).Italic(true)
roomStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("86")).Bold(true)
dmStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("141")).Bold(true)
noteStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("228")).Bold(true)
commandStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("39")).Italic(true)
timeStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("246"))
lockedStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("240")).Italic(true)
@@ -49,16 +49,17 @@ type model struct {
privKeySalt []byte
privKeyNonce []byte
currentRoomID string
currentRoomKey []byte
currentRoomJoinedAt time.Time
rooms []struct {
currentRoomID string
currentRoomEpoch int
// We cache keys: Epoch -> Plaintext Key
roomKeyCache map[int][]byte
rooms []struct {
ID string
Name string
Creator string
IsDM bool
}
availableUsers []string
err error
@@ -117,6 +118,7 @@ func initialModel(s ssh.Session) model {
input: ti,
viewport: vp,
updateChan: updates.subscribe(),
roomKeyCache: make(map[int][]byte),
}
}
@@ -225,6 +227,7 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
if val == "/leave" {
leaveRoom(m.currentRoomID, m.username)
m.rotateRoomKey(m.currentRoomID) // Rotate key on leave
m.exitChat()
return m, tea.ClearScreen
}
@@ -269,8 +272,9 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
func (m *model) exitChat() {
m.state = 1
m.currentRoomID = ""
m.currentRoomKey = nil
m.currentRoomEpoch = 0
m.messages = nil
m.roomKeyCache = make(map[int][]byte)
m.viewport.SetContent("")
m.loadRooms()
m.input.Reset()
@@ -299,7 +303,6 @@ func (m *model) handleRoomListInput(text string) {
m.handleJoinRoom(roomName)
return
}
// Keep /new as an alias for /join
if strings.HasPrefix(text, "/new ") {
roomName := strings.TrimPrefix(text, "/new ")
m.handleJoinRoom(roomName)
@@ -319,81 +322,74 @@ func (m *model) handleRoomListInput(text string) {
}
func (m *model) handleJoinRoom(roomName string) {
// Check if room exists
existingID, err := getRoomIDByName(roomName)
// Room Exists: Join it
if err == nil && existingID != "" {
// Need key
secret, err := getAnyRoomSecret(existingID)
if err != nil {
m.err = fmt.Errorf("could not join: room key unreachable")
return
}
if err := joinRoom(existingID, m.username, secret); err != nil {
// 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
}
// Room Does Not Exist: Create it
// Create new
roomID := generateRoomID()
if err := createRoom(roomID, roomName, m.username, false); err != nil {
m.err = err
return
}
sharedSecret := make([]byte, 32)
if _, err := io.ReadFull(rand.Reader, sharedSecret); err != nil {
if err := joinRoomMember(roomID, m.username); err != nil {
m.err = err
return
}
if err := joinRoom(roomID, m.username, sharedSecret); err != nil {
m.err = err
return
}
// Initial Key
m.rotateRoomKey(roomID)
m.enterRoom(roomID, roomName)
}
func (m *model) rotateRoomKey(roomID string) {
newKey := make([]byte, 32)
io.ReadFull(rand.Reader, newKey)
newEpoch, err := incrementRoomEpoch(roomID)
if err != nil {
m.err = err
return
}
members, err := getRoomMembers(roomID)
if err != nil {
m.err = err
return
}
for _, user := range members {
idKey, err := getMemberIdentityKey(user)
if err != nil {
continue
}
encrypted, err := EncryptKeyForUser(idKey, newKey)
if err != nil {
continue
}
storeUserRoomKey(user, roomID, newEpoch, encrypted)
}
}
func (m *model) handleSelectUserForDM(username string) {
if username == "/cancel" {
m.state = 1
m.input.Placeholder = "Enter room # or: /join <name>, /dm <username>, /list"
return
}
if username == m.username {
m.createNoteToSelf()
return
}
identityKey, prekey, prekeySignature, err := getUserKeys(username)
if err != nil {
m.err = fmt.Errorf("user not found: %w", err)
return
}
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)
sharedSecret := deriveSharedSecret(dh1, dh2, dh3)
roomID := generateRoomID()
roomName := fmt.Sprintf("DM: %s <-> %s", m.username, username)
@@ -401,56 +397,31 @@ func (m *model) handleSelectUserForDM(username string) {
m.err = err
return
}
joinRoomMember(roomID, m.username)
joinRoomMember(roomID, username)
if err := joinRoom(roomID, m.username, sharedSecret); err != nil {
m.err = err
return
}
m.rotateRoomKey(roomID)
m.enterRoom(roomID, roomName)
_ = prekeySignature
}
func (m *model) createNoteToSelf() {
roomID := generateRoomID()
roomName := "[Note to Self]"
sharedSecret := make([]byte, 32)
if _, err := io.ReadFull(rand.Reader, sharedSecret); err != nil {
m.err = err
return
}
if err := createRoom(roomID, roomName, m.username, true); err != nil {
m.err = err
return
}
if err := joinRoom(roomID, m.username, sharedSecret); err != nil {
m.err = err
return
}
joinRoomMember(roomID, m.username)
m.rotateRoomKey(roomID)
m.enterRoom(roomID, roomName)
}
func (m *model) enterRoom(roomID, roomName string) {
secret, err := getRoomSharedSecret(roomID, m.username)
if err != nil {
m.err = err
return
}
joinedAt, err := getMemberJoinedAt(roomID, m.username)
if err != nil {
joinedAt = time.Now() // Fallback
}
epoch, _ := getRoomCurrentEpoch(roomID)
m.currentRoomID = roomID
m.currentRoomKey = secret
m.currentRoomJoinedAt = joinedAt
m.currentRoomEpoch = epoch
m.state = 2
m.input.Placeholder = fmt.Sprintf("[%s] /back to menu, /leave to quit room", roomName)
m.input.Placeholder = fmt.Sprintf("[%s] /back, /leave, /delete", roomName)
m.loadMessages()
}
@@ -470,14 +441,42 @@ func generateRoomID() string {
return base64.URLEncoding.EncodeToString(b)
}
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) {
ct, nonce, err := encryptMsg(text, m.currentRoomKey)
m.currentRoomEpoch, _ = getRoomCurrentEpoch(m.currentRoomID)
key := m.getEpochKey(m.currentRoomEpoch)
if key == nil {
m.err = fmt.Errorf("no key for current epoch")
return
}
ct, nonce, err := encryptMsg(text, key)
if err != nil {
m.err = err
return
}
err = saveMessage(m.currentRoomID, sender, ct, nonce)
err = saveMessage(m.currentRoomID, sender, m.currentRoomEpoch, ct, nonce)
if err != nil {
m.err = err
return
@@ -499,10 +498,19 @@ func (m *model) loadMessages() {
var msgs []chatMsg
for _, dbMsg := range dbMessages {
plain, err := decryptMsg(dbMsg.Ciphertext, dbMsg.Nonce, m.currentRoomKey)
if err != nil {
plain = "[Decryption Failed]"
key := m.getEpochKey(dbMsg.Epoch)
var plain string
if key == nil {
plain = "[Unreadable: Old History or Key Rotated]"
} else {
p, err := decryptMsg(dbMsg.Ciphertext, dbMsg.Nonce, key)
if err != nil {
plain = "[Decryption Failed]"
} else {
plain = p
}
}
msgs = append(msgs, chatMsg{
Timestamp: dbMsg.Timestamp,
Sender: dbMsg.Sender,
@@ -518,12 +526,10 @@ func (m *model) updateViewport() {
for _, msg := range m.messages {
dateStr := msg.Timestamp.Format("Jan 2 15:04")
// Mask history before join time
// Add 1 second buffer to avoid hiding immediate first messages
if msg.Timestamp.Before(m.currentRoomJoinedAt.Add(-1 * time.Second)) {
if strings.Contains(msg.Content, "[Unreadable") {
b.WriteString(fmt.Sprintf("%s %s\n",
timeStyle.Render(dateStr),
lockedStyle.Render("[Encrypted message - History hidden]"),
lockedStyle.Render(msg.Content),
))
} else {
b.WriteString(fmt.Sprintf("%s %s: %s\n",