Refactor QR verification: Extract VerificationHandler and fix concurrency issues

2026-07-25 04:45:21 +00:00 · 2026-01-04 14:17:13 +07:00
parent 6b1ec534b6
commit 00cc9b3e75
3 changed files with 425 additions and 357 deletions
@@ -35,6 +35,7 @@ class SecureIdentityStateManager(private val context: Context) {
    }
    
    private val prefs: SharedPreferences
+    private val lock = Any()
    
    init {
        // Create master key for encryption
@@ -199,17 +200,23 @@ class SecureIdentityStateManager(private val context: Context) {

    fun setVerifiedFingerprint(fingerprint: String, verified: Boolean) {
        if (!isValidFingerprint(fingerprint)) return
-        val current = prefs.getStringSet(KEY_VERIFIED_FINGERPRINTS, emptySet())?.toMutableSet() ?: mutableSetOf()
-        if (verified) {
-            current.add(fingerprint)
-        } else {
-            current.remove(fingerprint)
+        synchronized(lock) {
+            val current = prefs.getStringSet(KEY_VERIFIED_FINGERPRINTS, emptySet())?.toMutableSet() ?: mutableSetOf()
+            if (verified) {
+                current.add(fingerprint)
+            } else {
+                current.remove(fingerprint)
+            }
+            prefs.edit { putStringSet(KEY_VERIFIED_FINGERPRINTS, current) }
        }
-        prefs.edit { putStringSet(KEY_VERIFIED_FINGERPRINTS, current) }
    }

    fun getCachedPeerFingerprint(peerID: String): String? {
        val pid = peerID.lowercase()
+        // Reading is safe without lock for SharedPreferences, but synchronizing ensures memory visibility
+        // if we are paranoid, but SharedPreferences is generally thread-safe for reads.
+        // However, to ensure we don't read a partial update (unlikely with SP), we can leave it.
+        // The critical part is the write.
        val entries = prefs.getStringSet(KEY_CACHED_PEER_FINGERPRINTS, emptySet()) ?: return null
        val entry = entries.firstOrNull { it.startsWith("$pid:") } ?: return null
        return entry.substringAfter(':').takeIf { isValidFingerprint(it) }
@@ -218,10 +225,12 @@ class SecureIdentityStateManager(private val context: Context) {
    fun cachePeerFingerprint(peerID: String, fingerprint: String) {
        if (!isValidFingerprint(fingerprint)) return
        val pid = peerID.lowercase()
-        val current = prefs.getStringSet(KEY_CACHED_PEER_FINGERPRINTS, emptySet())?.toMutableSet() ?: mutableSetOf()
-        current.removeAll { it.startsWith("$pid:") }
-        current.add("$pid:$fingerprint")
-        prefs.edit { putStringSet(KEY_CACHED_PEER_FINGERPRINTS, current) }
+        synchronized(lock) {
+            val current = prefs.getStringSet(KEY_CACHED_PEER_FINGERPRINTS, emptySet())?.toMutableSet() ?: mutableSetOf()
+            current.removeAll { it.startsWith("$pid:") }
+            current.add("$pid:$fingerprint")
+            prefs.edit { putStringSet(KEY_CACHED_PEER_FINGERPRINTS, current) }
+        }
    }

    fun getCachedNoiseKey(peerID: String): String? {
@@ -234,10 +243,12 @@ class SecureIdentityStateManager(private val context: Context) {
    fun cachePeerNoiseKey(peerID: String, noiseKeyHex: String) {
        if (!noiseKeyHex.matches(Regex("^[a-fA-F0-9]{64}$"))) return
        val pid = peerID.lowercase()
-        val current = prefs.getStringSet(KEY_CACHED_PEER_NOISE_KEYS, emptySet())?.toMutableSet() ?: mutableSetOf()
-        current.removeAll { it.startsWith("$pid=") }
-        current.add("$pid=${noiseKeyHex.lowercase()}")
-        prefs.edit { putStringSet(KEY_CACHED_PEER_NOISE_KEYS, current) }
+        synchronized(lock) {
+            val current = prefs.getStringSet(KEY_CACHED_PEER_NOISE_KEYS, emptySet())?.toMutableSet() ?: mutableSetOf()
+            current.removeAll { it.startsWith("$pid=") }
+            current.add("$pid=${noiseKeyHex.lowercase()}")
+            prefs.edit { putStringSet(KEY_CACHED_PEER_NOISE_KEYS, current) }
+        }
    }

    fun getCachedNoiseFingerprint(noiseKeyHex: String): String? {
@@ -251,10 +262,12 @@ class SecureIdentityStateManager(private val context: Context) {
        if (!isValidFingerprint(fingerprint)) return
        if (!noiseKeyHex.matches(Regex("^[a-fA-F0-9]{64}$"))) return
        val key = noiseKeyHex.lowercase()
-        val current = prefs.getStringSet(KEY_CACHED_NOISE_FINGERPRINTS, emptySet())?.toMutableSet() ?: mutableSetOf()
-        current.removeAll { it.startsWith("$key=") }
-        current.add("$key=$fingerprint")
-        prefs.edit { putStringSet(KEY_CACHED_NOISE_FINGERPRINTS, current) }
+        synchronized(lock) {
+            val current = prefs.getStringSet(KEY_CACHED_NOISE_FINGERPRINTS, emptySet())?.toMutableSet() ?: mutableSetOf()
+            current.removeAll { it.startsWith("$key=") }
+            current.add("$key=$fingerprint")
+            prefs.edit { putStringSet(KEY_CACHED_NOISE_FINGERPRINTS, current) }
+        }
    }

    fun getCachedFingerprintNickname(fingerprint: String): String? {
@@ -273,10 +286,12 @@ class SecureIdentityStateManager(private val context: Context) {
        if (!isValidFingerprint(fingerprint)) return
        val key = fingerprint.lowercase()
        val encoded = Base64.encodeToString(nickname.toByteArray(Charsets.UTF_8), Base64.NO_WRAP)
-        val current = prefs.getStringSet(KEY_CACHED_FINGERPRINT_NICKNAMES, emptySet())?.toMutableSet() ?: mutableSetOf()
-        current.removeAll { it.startsWith("$key=") }
-        current.add("$key=$encoded")
-        prefs.edit { putStringSet(KEY_CACHED_FINGERPRINT_NICKNAMES, current) }
+        synchronized(lock) {
+            val current = prefs.getStringSet(KEY_CACHED_FINGERPRINT_NICKNAMES, emptySet())?.toMutableSet() ?: mutableSetOf()
+            current.removeAll { it.startsWith("$key=") }
+            current.add("$key=$encoded")
+            prefs.edit { putStringSet(KEY_CACHED_FINGERPRINT_NICKNAMES, current) }
+        }
    }
    
    // MARK: - Peer ID Rotation Management (removed)
@@ -101,13 +101,15 @@ class ChatViewModel(
      NotificationIntervalManager()
    )

-    // QR verification state
-    private val _verifiedFingerprints = MutableStateFlow<Set<String>>(emptySet())
-    val verifiedFingerprints: StateFlow<Set<String>> = _verifiedFingerprints.asStateFlow()
-    private val pendingQRVerifications = mutableMapOf<String, PendingVerification>()
-    private val lastVerifyNonceByPeer = mutableMapOf<String, ByteArray>()
-    private val lastInboundVerifyChallengeAt = mutableMapOf<String, Long>()
-    private val lastMutualToastAt = mutableMapOf<String, Long>()
+    private val verificationHandler = VerificationHandler(
+        scope = viewModelScope,
+        meshService = meshService,
+        identityManager = identityManager,
+        state = state,
+        notificationManager = notificationManager,
+        messageManager = messageManager
+    )
+    val verifiedFingerprints = verificationHandler.verifiedFingerprints

    // Media file sending manager
    private val mediaSendingManager = MediaSendingManager(state, messageManager, channelManager, meshService)
@@ -284,7 +286,7 @@ class ChatViewModel(
        com.bitchat.android.favorites.FavoritesPersistenceService.initialize(getApplication())

        // Load verified fingerprints from secure storage
-        loadVerifiedFingerprints()
+        verificationHandler.loadVerifiedFingerprints()


        // Ensure NostrTransport knows our mesh peer ID for embedded packets
@@ -715,7 +717,7 @@ class ChatViewModel(
        // Flush any pending QR verification once a Noise session is established
        currentPeers.forEach { peerID ->
            if (meshService.getSessionState(peerID) is NoiseSession.NoiseSessionState.Established) {
-                sendPendingVerificationIfNeeded(peerID)
+                verificationHandler.sendPendingVerificationIfNeeded(peerID)
            }
        }
    }
@@ -724,125 +726,23 @@ class ChatViewModel(

    fun isPeerVerified(peerID: String, verifiedFingerprints: Set<String>): Boolean {
        if (peerID.startsWith("nostr_") || peerID.startsWith("nostr:")) return false
-        val fingerprint = getPeerFingerprintForDisplay(peerID)
+        val fingerprint = verificationHandler.getPeerFingerprintForDisplay(peerID)
        return fingerprint != null && verifiedFingerprints.contains(fingerprint)
    }

    fun isNoisePublicKeyVerified(noisePublicKey: ByteArray, verifiedFingerprints: Set<String>): Boolean {
-        val fingerprint = fingerprintFromNoiseBytes(noisePublicKey)
+        val fingerprint = verificationHandler.fingerprintFromNoiseBytes(noisePublicKey)
        return verifiedFingerprints.contains(fingerprint)
    }

-    private fun loadVerifiedFingerprints() {
-        val identityManager = SecureIdentityStateManager(getApplication())
-        _verifiedFingerprints.value = identityManager.getVerifiedFingerprints()
-    }
-
    fun unverifyFingerprint(peerID: String) {
-        val fingerprint = meshService.getPeerFingerprint(peerID) ?: return
-        val identityManager = SecureIdentityStateManager(getApplication())
-        identityManager.setVerifiedFingerprint(fingerprint, false)
-        _verifiedFingerprints.value -= fingerprint
+        verificationHandler.unverifyFingerprint(peerID)
    }

    fun beginQRVerification(qr: VerificationService.VerificationQR): Boolean {
-        val targetNoise = qr.noiseKeyHex.lowercase()
-        val peerID = state.getConnectedPeersValue().firstOrNull { pid ->
-            val noiseKeyHex = meshService.getPeerInfo(pid)?.noisePublicKey?.hexEncodedString()?.lowercase()
-            noiseKeyHex == targetNoise
-        } ?: return false
-
-        if (pendingQRVerifications.containsKey(peerID)) return true
-        val nonce = ByteArray(16)
-        java.security.SecureRandom().nextBytes(nonce)
-        val pending = PendingVerification(qr.noiseKeyHex, qr.signKeyHex, nonce, System.currentTimeMillis(), false)
-        pendingQRVerifications[peerID] = pending
-
-        if (meshService.getSessionState(peerID) is NoiseSession.NoiseSessionState.Established) {
-            meshService.sendVerifyChallenge(peerID, qr.noiseKeyHex, nonce)
-            pendingQRVerifications[peerID] = pending.copy(sent = true)
-        } else {
-            meshService.initiateNoiseHandshake(peerID)
-        }
-        fingerprintFromNoiseHex(qr.noiseKeyHex)?.let { fp ->
-            identityManager.cacheFingerprintNickname(fp, qr.nickname)
-            identityManager.cacheNoiseFingerprint(qr.noiseKeyHex, fp)
-            identityManager.cachePeerNoiseKey(peerID, qr.noiseKeyHex)
-        }
-        return true
+        return verificationHandler.beginQRVerification(qr)
    }

-    private fun sendPendingVerificationIfNeeded(peerID: String) {
-        val pending = pendingQRVerifications[peerID] ?: return
-        if (pending.sent) return
-        meshService.sendVerifyChallenge(peerID, pending.noiseKeyHex, pending.nonceA)
-        pendingQRVerifications[peerID] = pending.copy(sent = true)
-    }
-
-    private fun addVerificationSystemMessage(peerID: String, text: String) {
-        val msg = BitchatMessage(
-            sender = "system",
-            content = text,
-            timestamp = Date(),
-            isRelay = false,
-            isPrivate = true,
-            senderPeerID = peerID
-        )
-        messageManager.addPrivateMessageNoUnread(peerID, msg)
-    }
-
-    private fun resolvePeerDisplayName(peerID: String): String {
-        val nick = try { meshService.getPeerInfo(peerID)?.nickname } catch (_: Exception) { null }
-        return nick ?: peerID.take(8)
-    }
-
-    private fun sendVerificationNotification(title: String, body: String, peerID: String) {
-        notificationManager.showVerificationNotification(title, body, peerID)
-    }
-
-    // MARK: - Debug and Troubleshooting
-    
-    fun getDebugStatus(): String {
-        return meshService.getDebugStatus()
-    }
-    
-    // Note: Mesh service restart is now handled by MainActivity
-    // This function is no longer needed
-    
-    fun setAppBackgroundState(inBackground: Boolean) {
-        // Forward to notification manager for notification logic
-        notificationManager.setAppBackgroundState(inBackground)
-    }
-    
-    fun setCurrentPrivateChatPeer(peerID: String?) {
-        // Update notification manager with current private chat peer
-        notificationManager.setCurrentPrivateChatPeer(peerID)
-    }
-    
-    fun setCurrentGeohash(geohash: String?) {
-        // Update notification manager with current geohash for notification logic
-        notificationManager.setCurrentGeohash(geohash)
-    }
-
-    fun clearNotificationsForSender(peerID: String) {
-        // Clear notifications when user opens a chat
-        notificationManager.clearNotificationsForSender(peerID)
-    }
-    
-    fun clearNotificationsForGeohash(geohash: String) {
-        // Clear notifications when user opens a geohash chat
-        notificationManager.clearNotificationsForGeohash(geohash)
-    }
-
-    /**
-     * Clear mesh mention notifications when user opens mesh chat
-     */
-    fun clearMeshMentionNotifications() {
-        notificationManager.clearMeshMentionNotifications()
-    }
-
-    private var reopenSidebarAfterVerification = false
-
    fun showVerificationSheet(fromSidebar: Boolean = false) {
        if (fromSidebar) {
            reopenSidebarAfterVerification = true
@@ -867,128 +767,23 @@ class ChatViewModel(
    }

    fun getPeerFingerprintForDisplay(peerID: String): String? {
-        val fromMap = peerFingerprints.value[peerID]
-        if (fromMap != null) return fromMap
-        val hexRegex = Regex("^[0-9a-fA-F]+$")
-        return try {
-            when {
-                peerID.length == 64 && peerID.matches(hexRegex) -> {
-                    identityManager.getCachedNoiseFingerprint(peerID)?.let { return it }
-                    fingerprintFromNoiseHex(peerID)?.also { identityManager.cacheNoiseFingerprint(peerID, it) }
-                }
-                peerID.length == 16 && peerID.matches(hexRegex) -> {
-                    val meshFp = meshService.getPeerFingerprint(peerID)
-                    if (meshFp != null) return meshFp
-                    identityManager.getCachedPeerFingerprint(peerID)?.let { return it }
-                    identityManager.getCachedNoiseKey(peerID)?.let { noiseHex ->
-                        identityManager.getCachedNoiseFingerprint(noiseHex)?.let { return it }
-                        return fingerprintFromNoiseHex(noiseHex)?.also { identityManager.cacheNoiseFingerprint(noiseHex, it) }
-                    }
-                    val favorite = try {
-                        FavoritesPersistenceService.shared.getFavoriteStatus(peerID)
-                    } catch (_: Exception) {
-                        null
-                    }
-                    favorite?.peerNoisePublicKey?.let { fingerprintFromNoiseBytes(it) }
-                }
-                peerID.startsWith("nostr_") -> {
-                    val pubHex = GeohashAliasRegistry.get(peerID)
-                    val noiseKey = pubHex?.let {
-                        FavoritesPersistenceService.shared.findNoiseKey(it)
-                    }
-                    noiseKey?.let {
-                        val noiseHex = it.hexEncodedString()
-                        identityManager.getCachedNoiseFingerprint(noiseHex) ?: fingerprintFromNoiseBytes(it)
-                    }
-                }
-                peerID.startsWith("nostr:") -> {
-                    val prefix = peerID.removePrefix("nostr:").lowercase()
-                    val pubHex = GeohashAliasRegistry
-                        .snapshot()
-                        .values
-                        .firstOrNull { it.lowercase().startsWith(prefix) }
-                    val noiseKey = pubHex?.let {
-                        FavoritesPersistenceService.shared.findNoiseKey(it)
-                    }
-                    noiseKey?.let {
-                        val noiseHex = it.hexEncodedString()
-                        identityManager.getCachedNoiseFingerprint(noiseHex) ?: fingerprintFromNoiseBytes(it)
-                    }
-                }
-                else -> {
-                    val meshFp = meshService.getPeerFingerprint(peerID)
-                    if (meshFp != null) return meshFp
-                    identityManager.getCachedPeerFingerprint(peerID)?.let { return it }
-                    identityManager.getCachedNoiseKey(peerID)?.let { noiseHex ->
-                        identityManager.getCachedNoiseFingerprint(noiseHex)?.let { return it }
-                        return fingerprintFromNoiseHex(noiseHex)?.also { identityManager.cacheNoiseFingerprint(noiseHex, it) }
-                    }
-                    val favorite = try {
-                        FavoritesPersistenceService.shared.getFavoriteStatus(peerID)
-                    } catch (_: Exception) {
-                        null
-                    }
-                    favorite?.peerNoisePublicKey?.let { fingerprintFromNoiseBytes(it) }
-                }
-            }
-        } catch (_: Exception) {
-            null
-        }
+        return verificationHandler.getPeerFingerprintForDisplay(peerID)
    }

    fun getMyFingerprint(): String {
-        return meshService.getIdentityFingerprint()
+        return verificationHandler.getMyFingerprint()
    }

    fun resolvePeerDisplayNameForFingerprint(peerID: String): String {
-        val nicknameMap = peerNicknames.value
-        nicknameMap[peerID]?.let { return it }
-        try {
-            meshService.getPeerInfo(peerID)?.nickname?.let { return it }
-        } catch (_: Exception) { }
-
-        val fingerprint = getPeerFingerprintForDisplay(peerID)
-        fingerprint?.let { fp ->
-            identityManager.getCachedFingerprintNickname(fp)?.let { cached ->
-                if (cached.isNotBlank()) return cached
-            }
-        }
-
-        val hexRegex = Regex("^[0-9a-fA-F]+$")
-        if (peerID.length == 64 && peerID.matches(hexRegex)) {
-            val noiseKeyBytes = try {
-                peerID.chunked(2).map { it.toInt(16).toByte() }.toByteArray()
-            } catch (_: Exception) { null }
-            val favorite = noiseKeyBytes?.let {
-                FavoritesPersistenceService.shared.getFavoriteStatus(it)
-            }
-            favorite?.peerNickname?.takeIf { it.isNotBlank() }?.let { return it }
-        }
-
-        if (peerID.length == 16 && peerID.matches(hexRegex)) {
-            val favorite = try {
-                FavoritesPersistenceService.shared.getFavoriteStatus(peerID)
-            } catch (_: Exception) {
-                null
-            }
-            favorite?.peerNickname?.takeIf { it.isNotBlank() }?.let { return it }
-        }
-
-        return peerID.take(8)
+        return verificationHandler.resolvePeerDisplayNameForFingerprint(peerID)
    }

    fun verifyFingerprintValue(fingerprint: String) {
-        if (fingerprint.isBlank()) return
-        val identityManager = SecureIdentityStateManager(getApplication())
-        identityManager.setVerifiedFingerprint(fingerprint, true)
-        _verifiedFingerprints.value += fingerprint
+        verificationHandler.verifyFingerprintValue(fingerprint)
    }

    fun unverifyFingerprintValue(fingerprint: String) {
-        if (fingerprint.isBlank()) return
-        val identityManager = SecureIdentityStateManager(getApplication())
-        identityManager.setVerifiedFingerprint(fingerprint, false)
-        _verifiedFingerprints.value -= fingerprint
+        verificationHandler.unverifyFingerprintValue(fingerprint)
    }

    // MARK: - Command Autocomplete (delegated)
@@ -1034,78 +829,11 @@ class ChatViewModel(
    }

    override fun didReceiveVerifyChallenge(peerID: String, payload: ByteArray, timestampMs: Long) {
-        viewModelScope.launch {
-            val parsed = VerificationService.parseVerifyChallenge(payload) ?: return@launch
-            val myNoiseHex = meshService.getStaticNoisePublicKey()?.hexEncodedString()?.lowercase() ?: return@launch
-            if (parsed.first.lowercase() != myNoiseHex) return@launch
-
-            val lastNonce = lastVerifyNonceByPeer[peerID]
-            if (lastNonce != null && lastNonce.contentEquals(parsed.second)) return@launch
-            lastVerifyNonceByPeer[peerID] = parsed.second
-
-            val fp = meshService.getPeerFingerprint(peerID)
-            if (fp != null) {
-                lastInboundVerifyChallengeAt[fp] = System.currentTimeMillis()
-                if (_verifiedFingerprints.value.contains(fp)) {
-                    val lastToast = lastMutualToastAt[fp] ?: 0L
-                    if (System.currentTimeMillis() - lastToast > 60_000L) {
-                        lastMutualToastAt[fp] = System.currentTimeMillis()
-                        val name = resolvePeerDisplayName(peerID)
-                        val body = "You and $name verified each other"
-                        addVerificationSystemMessage(peerID, "mutual verification with $name")
-                        sendVerificationNotification("Mutual verification", body, peerID)
-                    }
-                }
-            }
-
-            meshService.sendVerifyResponse(peerID, parsed.first, parsed.second)
-        }
+        verificationHandler.didReceiveVerifyChallenge(peerID, payload)
    }

    override fun didReceiveVerifyResponse(peerID: String, payload: ByteArray, timestampMs: Long) {
-        viewModelScope.launch {
-            val resp = VerificationService.parseVerifyResponse(payload) ?: return@launch
-            val pending = pendingQRVerifications[peerID] ?: return@launch
-            if (!resp.noiseKeyHex.equals(pending.noiseKeyHex, ignoreCase = true)) return@launch
-            if (!resp.nonceA.contentEquals(pending.nonceA)) return@launch
-
-            val ok = VerificationService.verifyResponseSignature(
-                noiseKeyHex = resp.noiseKeyHex,
-                nonceA = resp.nonceA,
-                signature = resp.signature,
-                signerPublicKeyHex = pending.signKeyHex
-            )
-            if (!ok) return@launch
-
-            pendingQRVerifications.remove(peerID)
-            val fp = meshService.getPeerFingerprint(peerID) ?: return@launch
-            identityManager.setVerifiedFingerprint(fp, true)
-            _verifiedFingerprints.value = _verifiedFingerprints.value + fp
-            val name = resolvePeerDisplayName(peerID)
-            identityManager.cacheFingerprintNickname(fp, name)
-            val noiseKeyHex = try {
-                meshService.getPeerInfo(peerID)?.noisePublicKey?.hexEncodedString()
-            } catch (_: Exception) {
-                null
-            }
-            if (noiseKeyHex != null) {
-                identityManager.cachePeerNoiseKey(peerID, noiseKeyHex)
-                identityManager.cacheNoiseFingerprint(noiseKeyHex, fp)
-            }
-            addVerificationSystemMessage(peerID, "verified $name")
-            sendVerificationNotification("Verified", "You verified $name", peerID)
-
-            val lastChallenge = lastInboundVerifyChallengeAt[fp] ?: 0L
-            if (System.currentTimeMillis() - lastChallenge < 600_000L) {
-                val lastToast = lastMutualToastAt[fp] ?: 0L
-                if (System.currentTimeMillis() - lastToast > 60_000L) {
-                    lastMutualToastAt[fp] = System.currentTimeMillis()
-                    val body = "You and $name verified each other"
-                    addVerificationSystemMessage(peerID, "mutual verification with $name")
-                    sendVerificationNotification("Mutual verification", body, peerID)
-                }
-            }
-        }
+        verificationHandler.didReceiveVerifyResponse(peerID, payload)
    }
    
    override fun decryptChannelMessage(encryptedContent: ByteArray, channel: String): String? {
@@ -1316,16 +1044,6 @@ class ChatViewModel(
        }
    }

-    private fun fingerprintFromNoiseHex(noiseHex: String): String? {
-        val bytes = noiseHex.dataFromHexString() ?: return null
-        return fingerprintFromNoiseBytes(bytes)
-    }
-
-    private fun fingerprintFromNoiseBytes(bytes: ByteArray): String {
-        val hash = MessageDigest.getInstance("SHA-256").digest(bytes)
-        return hash.hexEncodedString()
-    }
-
    // MARK: - iOS-Compatible Color System

    /**
@@ -1344,36 +1062,6 @@ class ChatViewModel(
        return geohashViewModel.colorForNostrPubkey(pubkeyHex, isDark)
    }

-    private data class PendingVerification(
-        val noiseKeyHex: String,
-        val signKeyHex: String,
-        val nonceA: ByteArray,
-        val startedAtMs: Long,
-        val sent: Boolean
-    ) {
-        override fun equals(other: Any?): Boolean {
-            if (this === other) return true
-            if (javaClass != other?.javaClass) return false
-
-            other as PendingVerification
-
-            if (startedAtMs != other.startedAtMs) return false
-            if (sent != other.sent) return false
-            if (noiseKeyHex != other.noiseKeyHex) return false
-            if (signKeyHex != other.signKeyHex) return false
-            if (!nonceA.contentEquals(other.nonceA)) return false
-
-            return true
-        }
-
-        override fun hashCode(): Int {
-            var result = startedAtMs.hashCode()
-            result = 31 * result + sent.hashCode()
-            result = 31 * result + noiseKeyHex.hashCode()
-            result = 31 * result + signKeyHex.hashCode()
-            result = 31 * result + nonceA.contentHashCode()
-            return result
-        }
-    }
+}

 }
@@ -0,0 +1,365 @@
+package com.bitchat.android.ui
+
+import com.bitchat.android.favorites.FavoritesPersistenceService
+import com.bitchat.android.identity.SecureIdentityStateManager
+import com.bitchat.android.mesh.BluetoothMeshService
+import com.bitchat.android.model.BitchatMessage
+import com.bitchat.android.noise.NoiseSession
+import com.bitchat.android.nostr.GeohashAliasRegistry
+import com.bitchat.android.services.VerificationService
+import com.bitchat.android.util.dataFromHexString
+import com.bitchat.android.util.hexEncodedString
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.launch
+import java.security.MessageDigest
+import java.util.Date
+import java.util.concurrent.ConcurrentHashMap
+
+/**
+ * Handles QR verification logic and state, extracted from ChatViewModel.
+ */
+class VerificationHandler(
+    private val scope: CoroutineScope,
+    private val meshService: BluetoothMeshService,
+    private val identityManager: SecureIdentityStateManager,
+    private val state: ChatState,
+    private val notificationManager: NotificationManager,
+    private val messageManager: MessageManager
+) {
+
+    private val _verifiedFingerprints = MutableStateFlow<Set<String>>(emptySet())
+    val verifiedFingerprints: StateFlow<Set<String>> = _verifiedFingerprints.asStateFlow()
+
+    private val pendingQRVerifications = ConcurrentHashMap<String, PendingVerification>()
+    private val lastVerifyNonceByPeer = ConcurrentHashMap<String, ByteArray>()
+    private val lastInboundVerifyChallengeAt = ConcurrentHashMap<String, Long>()
+    private val lastMutualToastAt = ConcurrentHashMap<String, Long>()
+
+    fun loadVerifiedFingerprints() {
+        _verifiedFingerprints.value = identityManager.getVerifiedFingerprints()
+    }
+
+    fun isPeerVerified(peerID: String): Boolean {
+        if (peerID.startsWith("nostr_") || peerID.startsWith("nostr:")) return false
+        val fingerprint = getPeerFingerprintForDisplay(peerID)
+        return fingerprint != null && _verifiedFingerprints.value.contains(fingerprint)
+    }
+
+    fun isNoisePublicKeyVerified(noisePublicKey: ByteArray): Boolean {
+        val fingerprint = fingerprintFromNoiseBytes(noisePublicKey)
+        return _verifiedFingerprints.value.contains(fingerprint)
+    }
+
+    fun unverifyFingerprint(peerID: String) {
+        val fingerprint = meshService.getPeerFingerprint(peerID) ?: return
+        identityManager.setVerifiedFingerprint(fingerprint, false)
+        val current = _verifiedFingerprints.value.toMutableSet()
+        current.remove(fingerprint)
+        _verifiedFingerprints.value = current
+    }
+
+    fun beginQRVerification(qr: VerificationService.VerificationQR): Boolean {
+        val targetNoise = qr.noiseKeyHex.lowercase()
+        val peerID = state.getConnectedPeersValue().firstOrNull { pid ->
+            val noiseKeyHex = meshService.getPeerInfo(pid)?.noisePublicKey?.hexEncodedString()?.lowercase()
+            noiseKeyHex == targetNoise
+        } ?: return false
+
+        if (pendingQRVerifications.containsKey(peerID)) return true
+        val nonce = ByteArray(16)
+        java.security.SecureRandom().nextBytes(nonce)
+        val pending = PendingVerification(qr.noiseKeyHex, qr.signKeyHex, nonce, System.currentTimeMillis(), false)
+        pendingQRVerifications[peerID] = pending
+
+        if (meshService.getSessionState(peerID) is NoiseSession.NoiseSessionState.Established) {
+            meshService.sendVerifyChallenge(peerID, qr.noiseKeyHex, nonce)
+            pendingQRVerifications[peerID] = pending.copy(sent = true)
+        } else {
+            meshService.initiateNoiseHandshake(peerID)
+        }
+        fingerprintFromNoiseHex(qr.noiseKeyHex)?.let { fp ->
+            identityManager.cacheFingerprintNickname(fp, qr.nickname)
+            identityManager.cacheNoiseFingerprint(qr.noiseKeyHex, fp)
+            identityManager.cachePeerNoiseKey(peerID, qr.noiseKeyHex)
+        }
+        return true
+    }
+
+    fun sendPendingVerificationIfNeeded(peerID: String) {
+        val pending = pendingQRVerifications[peerID] ?: return
+        if (pending.sent) return
+        meshService.sendVerifyChallenge(peerID, pending.noiseKeyHex, pending.nonceA)
+        pendingQRVerifications[peerID] = pending.copy(sent = true)
+    }
+
+    fun didReceiveVerifyChallenge(peerID: String, payload: ByteArray) {
+        scope.launch {
+            val parsed = VerificationService.parseVerifyChallenge(payload) ?: return@launch
+            val myNoiseHex = meshService.getStaticNoisePublicKey()?.hexEncodedString()?.lowercase() ?: return@launch
+            if (parsed.first.lowercase() != myNoiseHex) return@launch
+
+            val lastNonce = lastVerifyNonceByPeer[peerID]
+            if (lastNonce != null && lastNonce.contentEquals(parsed.second)) return@launch
+            lastVerifyNonceByPeer[peerID] = parsed.second
+
+            val fp = meshService.getPeerFingerprint(peerID)
+            if (fp != null) {
+                lastInboundVerifyChallengeAt[fp] = System.currentTimeMillis()
+                if (_verifiedFingerprints.value.contains(fp)) {
+                    val lastToast = lastMutualToastAt[fp] ?: 0L
+                    if (System.currentTimeMillis() - lastToast > 60_000L) {
+                        lastMutualToastAt[fp] = System.currentTimeMillis()
+                        val name = resolvePeerDisplayName(peerID)
+                        val body = "You and $name verified each other"
+                        addVerificationSystemMessage(peerID, "mutual verification with $name")
+                        sendVerificationNotification("Mutual verification", body, peerID)
+                    }
+                }
+            }
+
+            meshService.sendVerifyResponse(peerID, parsed.first, parsed.second)
+        }
+    }
+
+    fun didReceiveVerifyResponse(peerID: String, payload: ByteArray) {
+        scope.launch {
+            val resp = VerificationService.parseVerifyResponse(payload) ?: return@launch
+            val pending = pendingQRVerifications[peerID] ?: return@launch
+            if (!resp.noiseKeyHex.equals(pending.noiseKeyHex, ignoreCase = true)) return@launch
+            if (!resp.nonceA.contentEquals(pending.nonceA)) return@launch
+
+            val ok = VerificationService.verifyResponseSignature(
+                noiseKeyHex = resp.noiseKeyHex,
+                nonceA = resp.nonceA,
+                signature = resp.signature,
+                signerPublicKeyHex = pending.signKeyHex
+            )
+            if (!ok) return@launch
+
+            pendingQRVerifications.remove(peerID)
+            val fp = meshService.getPeerFingerprint(peerID) ?: return@launch
+            identityManager.setVerifiedFingerprint(fp, true)
+            val current = _verifiedFingerprints.value.toMutableSet()
+            current.add(fp)
+            _verifiedFingerprints.value = current
+
+            val name = resolvePeerDisplayName(peerID)
+            identityManager.cacheFingerprintNickname(fp, name)
+            val noiseKeyHex = try {
+                meshService.getPeerInfo(peerID)?.noisePublicKey?.hexEncodedString()
+            } catch (_: Exception) {
+                null
+            }
+            if (noiseKeyHex != null) {
+                identityManager.cachePeerNoiseKey(peerID, noiseKeyHex)
+                identityManager.cacheNoiseFingerprint(noiseKeyHex, fp)
+            }
+            addVerificationSystemMessage(peerID, "verified $name")
+            sendVerificationNotification("Verified", "You verified $name", peerID)
+
+            val lastChallenge = lastInboundVerifyChallengeAt[fp] ?: 0L
+            if (System.currentTimeMillis() - lastChallenge < 600_000L) {
+                val lastToast = lastMutualToastAt[fp] ?: 0L
+                if (System.currentTimeMillis() - lastToast > 60_000L) {
+                    lastMutualToastAt[fp] = System.currentTimeMillis()
+                    val body = "You and $name verified each other"
+                    addVerificationSystemMessage(peerID, "mutual verification with $name")
+                    sendVerificationNotification("Mutual verification", body, peerID)
+                }
+            }
+        }
+    }
+
+    fun getPeerFingerprintForDisplay(peerID: String): String? {
+        val fromMap = state.getPeerFingerprintsValue()[peerID]
+        if (fromMap != null) return fromMap
+        val hexRegex = Regex("^[0-9a-fA-F]+$")
+        return try {
+            when {
+                peerID.length == 64 && peerID.matches(hexRegex) -> {
+                    identityManager.getCachedNoiseFingerprint(peerID)?.let { return it }
+                    fingerprintFromNoiseHex(peerID)?.also { identityManager.cacheNoiseFingerprint(peerID, it) }
+                }
+                peerID.length == 16 && peerID.matches(hexRegex) -> {
+                    val meshFp = meshService.getPeerFingerprint(peerID)
+                    if (meshFp != null) return meshFp
+                    identityManager.getCachedPeerFingerprint(peerID)?.let { return it }
+                    identityManager.getCachedNoiseKey(peerID)?.let { noiseHex ->
+                        identityManager.getCachedNoiseFingerprint(noiseHex)?.let { return it }
+                        return fingerprintFromNoiseHex(noiseHex)?.also { identityManager.cacheNoiseFingerprint(noiseHex, it) }
+                    }
+                    val favorite = try {
+                        FavoritesPersistenceService.shared.getFavoriteStatus(peerID)
+                    } catch (_: Exception) {
+                        null
+                    }
+                    favorite?.peerNoisePublicKey?.let { fingerprintFromNoiseBytes(it) }
+                }
+                peerID.startsWith("nostr_") -> {
+                    val pubHex = GeohashAliasRegistry.get(peerID)
+                    val noiseKey = pubHex?.let {
+                        FavoritesPersistenceService.shared.findNoiseKey(it)
+                    }
+                    noiseKey?.let {
+                        val noiseHex = it.hexEncodedString()
+                        identityManager.getCachedNoiseFingerprint(noiseHex) ?: fingerprintFromNoiseBytes(it)
+                    }
+                }
+                peerID.startsWith("nostr:") -> {
+                    val prefix = peerID.removePrefix("nostr:").lowercase()
+                    val pubHex = GeohashAliasRegistry
+                        .snapshot()
+                        .values
+                        .firstOrNull { it.lowercase().startsWith(prefix) }
+                    val noiseKey = pubHex?.let {
+                        FavoritesPersistenceService.shared.findNoiseKey(it)
+                    }
+                    noiseKey?.let {
+                        val noiseHex = it.hexEncodedString()
+                        identityManager.getCachedNoiseFingerprint(noiseHex) ?: fingerprintFromNoiseBytes(it)
+                    }
+                }
+                else -> {
+                    val meshFp = meshService.getPeerFingerprint(peerID)
+                    if (meshFp != null) return meshFp
+                    identityManager.getCachedPeerFingerprint(peerID)?.let { return it }
+                    identityManager.getCachedNoiseKey(peerID)?.let { noiseHex ->
+                        identityManager.getCachedNoiseFingerprint(noiseHex)?.let { return it }
+                        return fingerprintFromNoiseHex(noiseHex)?.also { identityManager.cacheNoiseFingerprint(noiseHex, it) }
+                    }
+                    val favorite = try {
+                        FavoritesPersistenceService.shared.getFavoriteStatus(peerID)
+                    } catch (_: Exception) {
+                        null
+                    }
+                    favorite?.peerNoisePublicKey?.let { fingerprintFromNoiseBytes(it) }
+                }
+            }
+        } catch (_: Exception) {
+            null
+        }
+    }
+
+    fun resolvePeerDisplayNameForFingerprint(peerID: String): String {
+        val nicknameMap = state.peerNicknames.value
+        nicknameMap[peerID]?.let { return it }
+        try {
+            meshService.getPeerInfo(peerID)?.nickname?.let { return it }
+        } catch (_: Exception) { }
+
+        val fingerprint = getPeerFingerprintForDisplay(peerID)
+        fingerprint?.let { fp ->
+            identityManager.getCachedFingerprintNickname(fp)?.let { cached ->
+                if (cached.isNotBlank()) return cached
+            }
+        }
+
+        val hexRegex = Regex("^[0-9a-fA-F]+$")
+        if (peerID.length == 64 && peerID.matches(hexRegex)) {
+            val noiseKeyBytes = try {
+                peerID.chunked(2).map { it.toInt(16).toByte() }.toByteArray()
+            } catch (_: Exception) { null }
+            val favorite = noiseKeyBytes?.let {
+                FavoritesPersistenceService.shared.getFavoriteStatus(it)
+            }
+            favorite?.peerNickname?.takeIf { it.isNotBlank() }?.let { return it }
+        }
+
+        if (peerID.length == 16 && peerID.matches(hexRegex)) {
+            val favorite = try {
+                FavoritesPersistenceService.shared.getFavoriteStatus(peerID)
+            } catch (_: Exception) {
+                null
+            }
+            favorite?.peerNickname?.takeIf { it.isNotBlank() }?.let { return it }
+        }
+
+        return peerID.take(8)
+    }
+
+    fun getMyFingerprint(): String {
+        return meshService.getIdentityFingerprint()
+    }
+
+    fun verifyFingerprintValue(fingerprint: String) {
+        if (fingerprint.isBlank()) return
+        identityManager.setVerifiedFingerprint(fingerprint, true)
+        val current = _verifiedFingerprints.value.toMutableSet()
+        current.add(fingerprint)
+        _verifiedFingerprints.value = current
+    }
+
+    fun unverifyFingerprintValue(fingerprint: String) {
+        if (fingerprint.isBlank()) return
+        identityManager.setVerifiedFingerprint(fingerprint, false)
+        val current = _verifiedFingerprints.value.toMutableSet()
+        current.remove(fingerprint)
+        _verifiedFingerprints.value = current
+    }
+
+    private fun addVerificationSystemMessage(peerID: String, text: String) {
+        val msg = BitchatMessage(
+            sender = "system",
+            content = text,
+            timestamp = Date(),
+            isRelay = false,
+            isPrivate = true,
+            senderPeerID = peerID
+        )
+        messageManager.addPrivateMessageNoUnread(peerID, msg)
+    }
+
+    private fun resolvePeerDisplayName(peerID: String): String {
+        val nick = try { meshService.getPeerInfo(peerID)?.nickname } catch (_: Exception) { null }
+        return nick ?: peerID.take(8)
+    }
+
+    private fun sendVerificationNotification(title: String, body: String, peerID: String) {
+        notificationManager.showVerificationNotification(title, body, peerID)
+    }
+
+    private fun fingerprintFromNoiseHex(noiseHex: String): String? {
+        val bytes = noiseHex.dataFromHexString() ?: return null
+        return fingerprintFromNoiseBytes(bytes)
+    }
+
+    fun fingerprintFromNoiseBytes(bytes: ByteArray): String {
+        val hash = MessageDigest.getInstance("SHA-256").digest(bytes)
+        return hash.hexEncodedString()
+    }
+
+    private data class PendingVerification(
+        val noiseKeyHex: String,
+        val signKeyHex: String,
+        val nonceA: ByteArray,
+        val startedAtMs: Long,
+        val sent: Boolean
+    ) {
+        override fun equals(other: Any?): Boolean {
+            if (this === other) return true
+            if (javaClass != other?.javaClass) return false
+
+            other as PendingVerification
+
+            if (startedAtMs != other.startedAtMs) return false
+            if (sent != other.sent) return false
+            if (noiseKeyHex != other.noiseKeyHex) return false
+            if (signKeyHex != other.signKeyHex) return false
+            if (!nonceA.contentEquals(other.nonceA)) return false
+
+            return true
+        }
+
+        override fun hashCode(): Int {
+            var result = startedAtMs.hashCode()
+            result = 31 * result + sent.hashCode()
+            result = 31 * result + noiseKeyHex.hashCode()
+            result = 31 * result + signKeyHex.hashCode()
+            result = 31 * result + nonceA.contentHashCode()
+            return result
+        }
+    }
+}