Make Noise generation race test deterministic

bitchat/App/ConversationUIModel.swift

@@ -12,6 +12,7 @@ final class ConversationUIModel: ObservableObject {
     @Published private(set) var currentNickname: String
     @Published private(set) var isBatchingPublic = false
     @Published private(set) var canSendMediaInCurrentContext = true
+    @Published private(set) var legacyPrivateMediaConsentRequest: LegacyPrivateMediaConsentRequest?
     /// Who is talking live in the public mesh channel right now (floor
     /// courtesy: the composer mic tints "busy" while someone holds the floor).
     @Published private(set) var activeLiveVoiceTalker: String?
@@ -153,6 +154,13 @@ final class ConversationUIModel: ObservableObject {
         chatViewModel.sendVoiceNote(at: url)
     }
 
+    func resolveLegacyPrivateMediaConsent(requestID: UUID, approved: Bool) {
+        chatViewModel.resolveLegacyPrivateMediaConsent(
+            requestID: requestID,
+            approved: approved
+        )
+    }
+
     /// Capture backend for the mic gesture: live PTT when the current DM
     /// peer can hear it now, classic voice note otherwise.
     func makeVoiceCaptureSession() -> VoiceCaptureSession {
@@ -193,6 +201,10 @@ final class ConversationUIModel: ObservableObject {
             .receive(on: DispatchQueue.main)
             .assign(to: &$activeLiveVoiceTalker)
 
+        chatViewModel.$legacyPrivateMediaConsentRequest
+            .receive(on: DispatchQueue.main)
+            .assign(to: &$legacyPrivateMediaConsentRequest)
+
         conversations.$activeChannel
             .receive(on: DispatchQueue.main)
             .sink { [weak self] channel in

bitchat/Identity/IdentityModels.swift

@@ -189,6 +189,18 @@ struct IdentityCache: Codable {
     // Fingerprint -> when we verified it (orders outgoing vouch batches;
     // entries verified before this field exists sort as oldest)
     var verifiedAt: [String: Date]? = nil
+
+    // Stable Noise fingerprints that proved encrypted private-media support
+    // inside an authenticated Noise session. Optional for decoding caches
+    // written before this migration. Entries are monotonic until a panic wipe
+    // so an old/replayed announce cannot silently downgrade a peer.
+    var privateMediaCapableFingerprints: Set<String>? = nil
+
+    // Noise-fingerprint -> Ed25519 announcement key, learned only from the
+    // authenticated peer-state payload. This prevents a self-signed announce
+    // containing a copied public Noise key from replacing a previously bound
+    // public-message signing identity. Optional for old cache compatibility.
+    var authenticatedSigningKeysByFingerprint: [String: Data]? = nil
 }
 
 //

bitchat/Identity/SecureIdentityStateManager.swift

@@ -140,6 +140,14 @@ protocol SecureIdentityStateManagerProtocol {
     func markVouchBatchSent(to fingerprint: String, at date: Date)
     func signingPublicKey(forFingerprint fingerprint: String) -> Data?
     func mostRecentlyVerifiedFingerprints(limit: Int, excluding fingerprint: String) -> [String]
+
+    // MARK: Noise-authenticated announcement identity
+    func bindAuthenticatedSigningPublicKey(_ signingPublicKey: Data, fingerprint: String)
+    func authenticatedSigningPublicKey(forFingerprint fingerprint: String) -> Data?
+
+    // MARK: Private-media downgrade protection
+    func markPrivateMediaCapable(fingerprint: String)
+    func hasObservedPrivateMediaCapability(fingerprint: String) -> Bool
 }
 
 /// Singleton manager for secure identity state persistence and retrieval.
@@ -157,6 +165,7 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
     
     // Thread safety
     private let queue = DispatchQueue(label: "bitchat.identity.state", attributes: .concurrent)
+    private let queueSpecificKey = DispatchSpecificKey<UInt8>()
     
     // Pending-save coalescing flag. Reads/writes are serialized on `queue`.
     // Persistence is done with a fire-and-forget `queue.async(.barrier)` rather
@@ -214,6 +223,7 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
 
         self.encryptionKey = loadedKey
         self.encryptionKeyIsEphemeral = keyIsEphemeral
+        queue.setSpecific(key: queueSpecificKey, value: 1)
 
         // Only read the persisted cache when we hold the real key; with an
         // ephemeral key the decrypt would fail and discard the real cache.
@@ -371,6 +381,66 @@ final class SecureIdentityStateManager: SecureIdentityStateManagerProtocol {
         }
     }
 
+    // MARK: - Private-media downgrade protection
+
+    func markPrivateMediaCapable(fingerprint: String) {
+        guard !fingerprint.isEmpty else { return }
+        let insertAndPersist = {
+            var pinned = self.cache.privateMediaCapableFingerprints ?? []
+            guard pinned.insert(fingerprint).inserted else { return }
+            self.cache.privateMediaCapableFingerprints = pinned
+            self.saveIdentityCache()
+        }
+        // Downgrade decisions can run immediately after an authenticated
+        // announce. Make the pin visible before returning; merely enqueueing a
+        // barrier leaves a cross-queue window where a replay can look legacy.
+        // The queue-specific fast path prevents self-deadlock if a future
+        // identity-state mutation records the capability from inside `queue`.
+        if DispatchQueue.getSpecific(key: queueSpecificKey) != nil {
+            insertAndPersist()
+        } else {
+            queue.sync(flags: .barrier, execute: insertAndPersist)
+        }
+    }
+
+    func hasObservedPrivateMediaCapability(fingerprint: String) -> Bool {
+        guard !fingerprint.isEmpty else { return false }
+        return queue.sync {
+            cache.privateMediaCapableFingerprints?.contains(fingerprint) == true
+        }
+    }
+
+    // MARK: - Noise-authenticated announcement identity
+
+    func bindAuthenticatedSigningPublicKey(_ signingPublicKey: Data, fingerprint: String) {
+        guard signingPublicKey.count == AuthenticatedPeerStatePacket.signingPublicKeyLength,
+              !fingerprint.isEmpty else { return }
+        let bindAndPersist = {
+            var bindings = self.cache.authenticatedSigningKeysByFingerprint ?? [:]
+            let bindingChanged = bindings[fingerprint] != signingPublicKey
+            bindings[fingerprint] = signingPublicKey
+            self.cache.authenticatedSigningKeysByFingerprint = bindings
+            if var cryptoIdentity = self.cryptographicIdentities[fingerprint] {
+                cryptoIdentity.signingPublicKey = signingPublicKey
+                self.cryptographicIdentities[fingerprint] = cryptoIdentity
+            }
+            guard bindingChanged else { return }
+            self.saveIdentityCache()
+        }
+        if DispatchQueue.getSpecific(key: queueSpecificKey) != nil {
+            bindAndPersist()
+        } else {
+            queue.sync(flags: .barrier, execute: bindAndPersist)
+        }
+    }
+
+    func authenticatedSigningPublicKey(forFingerprint fingerprint: String) -> Data? {
+        guard !fingerprint.isEmpty else { return nil }
+        return queue.sync {
+            cache.authenticatedSigningKeysByFingerprint?[fingerprint]
+        }
+    }
+    
     func updateSocialIdentity(_ identity: SocialIdentity) {
         queue.async(flags: .barrier) {
             let previousClaimedNickname = self.cache.socialIdentities[identity.fingerprint]?.claimedNickname

bitchat/Models/NoisePayload.swift

@@ -30,7 +30,7 @@ struct NoisePayload {
         
         // Safely get the first byte
         let firstByte = data[data.startIndex]
-        guard let type = NoisePayloadType(rawValue: firstByte) else {
+        guard let type = NoisePayloadType.decoded(rawValue: firstByte) else {
             return nil
         }
         

bitchat/Noise/NoiseSecurityConstants.swift

@@ -6,15 +6,37 @@
 // For more information, see <https://unlicense.org>
 //
 
+import BitFoundation
 import Foundation
 
 enum NoiseSecurityConstants {
     // Maximum message size to prevent memory exhaustion
     static let maxMessageSize = 65535 // 64KB as per Noise spec
 
+    /// The extracted transport nonce (4 bytes) and Poly1305 tag (16 bytes)
+    /// added by `NoiseCipherState` around every transport plaintext.
+    static let transportCiphertextOverhead = 20
+
+    /// Private files are an explicit BitChat extension to the ordinary Noise
+    /// message-size ceiling. They remain bounded by the same framed-file cap
+    /// used by the binary and fragment decoders. Only the `.privateFile`
+    /// typed-payload path is allowed to use this larger budget.
+    private static let privateFileOuterPacketOverhead =
+        (BinaryProtocol.v1HeaderSize + 2) // v2 adds two length bytes
+        + BinaryProtocol.senderIDSize
+        + BinaryProtocol.recipientIDSize
+    static let maxPrivateFilePlaintextSize = FileTransferLimits.maxFramedFileBytes
+        - privateFileOuterPacketOverhead
+        - transportCiphertextOverhead
+    static let maxPrivateFileCiphertextSize =
+        maxPrivateFilePlaintextSize + transportCiphertextOverhead
+    
     // Maximum handshake message size
     static let maxHandshakeMessageSize = 2048 // 2KB to accommodate XX pattern
 
+    // Noise XX message 1 contains only the initiator's 32-byte ephemeral key.
+    static let xxInitialMessageSize = 32
+    
     // Session timeout - sessions older than this should be renegotiated
     static let sessionTimeout: TimeInterval = 86400 // 24 hours
     

bitchat/Noise/NoiseSecurityValidator.swift

@@ -15,6 +15,19 @@ struct NoiseSecurityValidator {
         return data.count <= NoiseSecurityConstants.maxMessageSize
     }
 
+    static func validateCiphertextSize(_ data: Data) -> Bool {
+        data.count <= NoiseSecurityConstants.maxMessageSize
+            + NoiseSecurityConstants.transportCiphertextOverhead
+    }
+
+    static func validatePrivateFileMessageSize(_ data: Data) -> Bool {
+        data.count <= NoiseSecurityConstants.maxPrivateFilePlaintextSize
+    }
+
+    static func validatePrivateFileCiphertextSize(_ data: Data) -> Bool {
+        data.count <= NoiseSecurityConstants.maxPrivateFileCiphertextSize
+    }
+    
     /// Validate handshake message size
     static func validateHandshakeMessageSize(_ data: Data) -> Bool {
         return data.count <= NoiseSecurityConstants.maxHandshakeMessageSize

bitchat/Noise/NoiseSessionError.swift

@@ -11,4 +11,5 @@ enum NoiseSessionError: Error, Equatable {
     case notEstablished
     case sessionNotFound
     case alreadyEstablished
+    case peerIdentityMismatch
 }

bitchat/Noise/NoiseSessionManager.swift

@@ -13,11 +13,20 @@ import BitFoundation
 
 final class NoiseSessionManager {
     private var sessions: [PeerID: NoiseSession] = [:]
+    /// Opaque identity for each exact entry in `sessions`. The generation is
+    /// created and removed under the same barrier as the session itself, so a
+    /// caller can never authenticate data with one session and lease another.
+    private var sessionGenerations: [PeerID: UUID] = [:]
+    /// A responder rehandshake must not evict a working transport session
+    /// before the candidate proves that its authenticated static key belongs
+    /// to the claimed wire ID. Candidates therefore live outside `sessions`
+    /// until the XX handshake completes and the binding is validated.
+    private var responderCandidates: [PeerID: NoiseSession] = [:]
     private let sessionFactory: (PeerID, NoiseRole) -> NoiseSession
     private let managerQueue = DispatchQueue(label: "chat.bitchat.noise.manager", attributes: .concurrent)
     
     // Callbacks
-    var onSessionEstablished: ((PeerID, Curve25519.KeyAgreement.PublicKey) -> Void)?
+    var onSessionEstablished: ((PeerID, Curve25519.KeyAgreement.PublicKey, UUID) -> Void)?
     var onSessionFailed: ((PeerID, Error) -> Void)?
     
     init(localStaticKey: Curve25519.KeyAgreement.PrivateKey, keychain: KeychainManagerProtocol) {
@@ -54,6 +63,10 @@ final class NoiseSessionManager {
             if let session = sessions.removeValue(forKey: peerID) {
                 session.reset() // Clear sensitive data before removing
             }
+            sessionGenerations.removeValue(forKey: peerID)
+            if let candidate = responderCandidates.removeValue(forKey: peerID) {
+                candidate.reset()
+            }
         }
     }
 
@@ -62,7 +75,12 @@ final class NoiseSessionManager {
             for (_, session) in sessions {
                 session.reset()
             }
+            for (_, candidate) in responderCandidates {
+                candidate.reset()
+            }
             sessions.removeAll()
+            sessionGenerations.removeAll()
+            responderCandidates.removeAll()
         }
     }
     
@@ -79,11 +97,14 @@ final class NoiseSessionManager {
             // Remove any existing non-established session
             if let existingSession = sessions[peerID], !existingSession.isEstablished() {
                 _ = sessions.removeValue(forKey: peerID)
+                sessionGenerations.removeValue(forKey: peerID)
+                existingSession.reset()
             }
             
             // Create new initiator session
             let session = sessionFactory(peerID, .initiator)
             sessions[peerID] = session
+            sessionGenerations[peerID] = UUID()
             
             do {
                 let handshakeData = try session.startHandshake()
@@ -91,6 +112,8 @@ final class NoiseSessionManager {
             } catch {
                 // Clean up failed session
                 _ = sessions.removeValue(forKey: peerID)
+                sessionGenerations.removeValue(forKey: peerID)
+                session.reset()
                 SecureLogger.error(.handshakeFailed(peerID: peerID.id, error: error.localizedDescription))
                 throw error
             }
@@ -98,41 +121,64 @@ final class NoiseSessionManager {
     }
     
     func handleIncomingHandshake(from peerID: PeerID, message: Data) throws -> Data? {
-        // Process everything within the synchronized block to prevent race conditions
-        return try managerQueue.sync(flags: .barrier) {
-            var shouldCreateNew = false
-            var existingSession: NoiseSession? = nil
-            
-            if let existing = sessions[peerID] {
-                // If we have an established session, the peer must have cleared their session
-                // for a good reason (e.g., decryption failure, restart, etc.)
-                // We should accept the new handshake to re-establish encryption
-                if existing.isEstablished() {
-                    SecureLogger.info("Accepting handshake from \(peerID) despite existing session - peer likely cleared their session", category: .session)
-                    _ = sessions.removeValue(forKey: peerID)
-                    shouldCreateNew = true
-                } else {
-                    // If we're in the middle of a handshake and receive a new initiation,
-                    // reset and start fresh (the other side may have restarted)
-                    if existing.getState() == .handshaking && message.count == 32 {
-                        _ = sessions.removeValue(forKey: peerID)
-                        shouldCreateNew = true
-                    } else {
-                        existingSession = existing
-                    }
-                }
-            } else {
-                shouldCreateNew = true
-            }
-            
-            // Get or create session
+        // Process everything within the synchronized block to prevent race conditions.
+        // Return establishment metadata and publish the callback only after the
+        // manager barrier is released, avoiding both a deadlock and a window in
+        // which `processHandshakeMessage` returns before authentication state.
+        let result: (
+            response: Data?,
+            establishedSession: (
+                remoteKey: Curve25519.KeyAgreement.PublicKey,
+                generation: UUID
+            )?
+        ) = try managerQueue.sync(flags: .barrier) {
             let session: NoiseSession
-            if shouldCreateNew {
+            let isReplacementCandidate: Bool
+
+            if let candidate = responderCandidates[peerID] {
+                // A fresh XX message 1 supersedes an incomplete candidate,
+                // but never the established session it is trying to replace.
+                if message.count == NoiseSecurityConstants.xxInitialMessageSize {
+                    candidate.reset()
+                    let replacement = sessionFactory(peerID, .responder)
+                    responderCandidates[peerID] = replacement
+                    session = replacement
+                } else {
+                    session = candidate
+                }
+                isReplacementCandidate = true
+            } else if let existing = sessions[peerID] {
+                if existing.isEstablished() {
+                    SecureLogger.info(
+                        "Validating replacement handshake from \(peerID) while preserving the established session",
+                        category: .session
+                    )
+                    let candidate = sessionFactory(peerID, .responder)
+                    responderCandidates[peerID] = candidate
+                    session = candidate
+                    isReplacementCandidate = true
+                } else if existing.getState() == .handshaking,
+                          message.count == NoiseSecurityConstants.xxInitialMessageSize {
+                    // No established transport state exists to preserve. A
+                    // fresh initiation replaces the incomplete handshake.
+                    _ = sessions.removeValue(forKey: peerID)
+                    sessionGenerations.removeValue(forKey: peerID)
+                    existing.reset()
+                    let replacement = sessionFactory(peerID, .responder)
+                    sessions[peerID] = replacement
+                    sessionGenerations[peerID] = UUID()
+                    session = replacement
+                    isReplacementCandidate = false
+                } else {
+                    session = existing
+                    isReplacementCandidate = false
+                }
+            } else {
                 let newSession = sessionFactory(peerID, .responder)
                 sessions[peerID] = newSession
+                sessionGenerations[peerID] = UUID()
                 session = newSession
-            } else {
-                session = existingSession!
+                isReplacementCandidate = false
             }
             
             // Process the handshake message within the synchronized block
@@ -140,19 +186,46 @@ final class NoiseSessionManager {
                 let response = try session.processHandshakeMessage(message)
                 
                 // Check if session is established after processing
+                var establishedSession: (
+                    remoteKey: Curve25519.KeyAgreement.PublicKey,
+                    generation: UUID
+                )?
                 if session.isEstablished() {
-                    if let remoteKey = session.getRemoteStaticPublicKey() {
-                        // Schedule callback outside the synchronized block to prevent deadlock
-                        DispatchQueue.global().async { [weak self] in
-                            self?.onSessionEstablished?(peerID, remoteKey)
-                        }
-                    }
+                    guard let remoteKey = session.getRemoteStaticPublicKey(),
+                          authenticatedRemoteKey(remoteKey, matches: peerID) else {
+                        throw NoiseSessionError.peerIdentityMismatch
                     }
 
-                return response
+                    if isReplacementCandidate {
+                        _ = responderCandidates.removeValue(forKey: peerID)
+                        let previous = sessions.updateValue(session, forKey: peerID)
+                        sessionGenerations[peerID] = UUID()
+                        if let previous, previous !== session {
+                            previous.reset()
+                        }
+                    }
+                    guard let generation = sessionGenerations[peerID] else {
+                        throw NoiseEncryptionError.sessionNotEstablished
+                    }
+                    establishedSession = (remoteKey, generation)
+                }
+                
+                return (response, establishedSession)
             } catch {
-                // Reset the session on handshake failure so next attempt can start fresh
+                // A failed candidate is discarded without touching the
+                // established session. Ordinary failed handshakes retain the
+                // historical cleanup behavior.
+                if isReplacementCandidate {
+                    if let storedCandidate = responderCandidates[peerID],
+                       storedCandidate === session {
+                        _ = responderCandidates.removeValue(forKey: peerID)
+                    }
+                } else if let storedSession = sessions[peerID],
+                          storedSession === session {
                     _ = sessions.removeValue(forKey: peerID)
+                    sessionGenerations.removeValue(forKey: peerID)
+                }
+                session.reset()
                 
                 // Schedule callback outside the synchronized block to prevent deadlock
                 DispatchQueue.global().async { [weak self] in
@@ -163,24 +236,102 @@ final class NoiseSessionManager {
                 throw error
             }
         }
+
+        if let established = result.establishedSession {
+            onSessionEstablished?(peerID, established.remoteKey, established.generation)
+        }
+        return result.response
+    }
+
+    /// Mesh handshakes normally use a 16-hex wire ID. Full Noise-key IDs are
+    /// also accepted by internal callers when they exactly match the static
+    /// key. Non-wire identifiers remain available to protocol test harnesses;
+    /// BLE packet ingress always supplies a short hexadecimal ID.
+    private func authenticatedRemoteKey(
+        _ remoteKey: Curve25519.KeyAgreement.PublicKey,
+        matches claimedPeerID: PeerID
+    ) -> Bool {
+        let rawKey = remoteKey.rawRepresentation
+        if claimedPeerID.isShort {
+            return PeerID(publicKey: rawKey) == claimedPeerID
+        }
+        if let claimedNoiseKey = claimedPeerID.noiseKey {
+            return claimedNoiseKey == rawKey
+        }
+        return true
     }
     
     // MARK: - Encryption/Decryption
     
     func encrypt(_ plaintext: Data, for peerID: PeerID) throws -> Data {
-        guard let session = getSession(for: peerID) else {
+        try managerQueue.sync {
+            guard let session = sessions[peerID] else {
                 throw NoiseSessionError.sessionNotFound
             }
-        
             return try session.encrypt(plaintext)
         }
+    }
+
+    /// Encrypts only if `expected` still names the current established entry.
+    /// A rekey between capability proof and media encryption therefore fails
+    /// closed instead of sending on an unproven replacement session.
+    func encrypt(
+        _ plaintext: Data,
+        for peerID: PeerID,
+        expectedSessionGeneration expected: UUID
+    ) throws -> Data {
+        try managerQueue.sync {
+            guard let session = sessions[peerID],
+                  session.isEstablished(),
+                  sessionGenerations[peerID] == expected else {
+                throw NoiseEncryptionError.sessionNotEstablished
+            }
+            return try session.encrypt(plaintext)
+        }
+    }
     
     func decrypt(_ ciphertext: Data, from peerID: PeerID) throws -> Data {
-        guard let session = getSession(for: peerID) else {
-            throw NoiseSessionError.sessionNotFound
+        try decryptWithSessionGeneration(ciphertext, from: peerID).plaintext
     }
 
-        return try session.decrypt(ciphertext)
+    func sessionGeneration(for peerID: PeerID) -> UUID? {
+        managerQueue.sync {
+            guard sessions[peerID]?.isEstablished() == true else { return nil }
+            return sessionGenerations[peerID]
+        }
+    }
+
+    /// Decrypts while holding the manager's read lease. Session promotion and
+    /// removal require its barrier, so the returned generation always names
+    /// the exact session object that authenticated these bytes.
+    func decryptWithSessionGeneration(
+        _ ciphertext: Data,
+        from peerID: PeerID
+    ) throws -> (plaintext: Data, sessionGeneration: UUID) {
+        try managerQueue.sync {
+            guard let session = sessions[peerID] else {
+                throw NoiseSessionError.sessionNotFound
+            }
+            guard session.isEstablished(),
+                  let generation = sessionGenerations[peerID] else {
+                throw NoiseEncryptionError.sessionNotEstablished
+            }
+            return (try session.decrypt(ciphertext), generation)
+        }
+    }
+
+    /// Runs a state commit under a read lease for the exact established
+    /// session. Rekey, replacement, and removal all need the same barrier.
+    func withCurrentSessionGeneration<Result>(
+        for peerID: PeerID,
+        expected: UUID,
+        _ body: () -> Result
+    ) -> Result? {
+        managerQueue.sync {
+            guard sessions[peerID]?.isEstablished() == true,
+                  sessionGenerations[peerID] == expected else { return nil }
+            return body()
+        }
     }
     
     // MARK: - Key Management
@@ -207,11 +358,11 @@ final class NoiseSessionManager {
         }
     }
     
-    func initiateRekey(for peerID: PeerID) throws {
+    func initiateRekey(for peerID: PeerID) throws -> Data {
         // Remove old session
         removeSession(for: peerID)
         
         // Initiate new handshake
-        _ = try initiateHandshake(with: peerID)
+        return try initiateHandshake(with: peerID)
     }
 }

bitchat/Noise/SecureNoiseSession.swift

@@ -24,8 +24,12 @@ final class SecureNoiseSession: NoiseSession {
             throw NoiseSecurityError.sessionExhausted
         }
         
-        // Validate message size
-        guard NoiseSecurityValidator.validateMessageSize(plaintext) else {
+        // Ordinary Noise messages keep the protocol ceiling. Finalized media
+        // is the sole typed-payload extension and remains under the framed-file
+        // cap enforced again at the service and file-decoder layers.
+        let isPrivateFile = NoisePayloadType.isPrivateFile(rawValue: plaintext.first)
+            && NoiseSecurityValidator.validatePrivateFileMessageSize(plaintext)
+        guard NoiseSecurityValidator.validateMessageSize(plaintext) || isPrivateFile else {
             throw NoiseSecurityError.messageTooLarge
         }
         
@@ -42,8 +46,11 @@ final class SecureNoiseSession: NoiseSession {
             throw NoiseSecurityError.sessionExpired
         }
         
-        // Validate message size
-        guard NoiseSecurityValidator.validateMessageSize(ciphertext) else {
+        // The payload type is encrypted, so a large candidate can only be
+        // bounded here; `NoiseEncryptionService.decrypt` authenticates it and
+        // then requires the resulting type to be `.privateFile`.
+        guard NoiseSecurityValidator.validateCiphertextSize(ciphertext)
+                || NoiseSecurityValidator.validatePrivateFileCiphertextSize(ciphertext) else {
             throw NoiseSecurityError.messageTooLarge
         }
         

bitchat/Protocols/BitchatProtocol.swift

@@ -79,12 +79,35 @@ enum NoisePayloadType: UInt8 {
     case groupKeyUpdate = 0x07      // Creator-signed group state (key rotation / roster update)
     // Live voice (push-to-talk)
     case voiceFrame = 0x08          // One live voice-burst packet (see VoiceBurstPacket)
+    // Finalized private media. `0x20` is the value already deployed by the
+    // Android client. The complete BitchatFilePacket is encrypted inside
+    // Noise before the outer noiseEncrypted packet is fragmented.
+    case privateFile = 0x20
+    // Versioned peer state authenticated by the surrounding Noise session.
+    // This is intentionally distinct from the public announce: announce
+    // capabilities are discovery hints, while this payload proves possession
+    // of the advertised Noise static key before downgrade state is pinned.
+    case authenticatedPeerState = 0x21
     // Verification (QR-based OOB binding)
     case verifyChallenge = 0x10     // Verification challenge
     case verifyResponse  = 0x11     // Verification response
     // Transitive verification (web of trust)
     case vouch = 0x12               // Batch of vouch attestations
 
+    /// #1434 briefly used 0x09 before release. Accept it while prerelease
+    /// builds age out, but never emit it. Decoders canonicalize both values to
+    /// `.privateFile` so the compatibility alias cannot leak into app logic.
+    static let prereleasePrivateFileRawValue: UInt8 = 0x09
+
+    static func decoded(rawValue: UInt8) -> NoisePayloadType? {
+        rawValue == prereleasePrivateFileRawValue ? .privateFile : Self(rawValue: rawValue)
+    }
+
+    static func isPrivateFile(rawValue: UInt8?) -> Bool {
+        guard let rawValue else { return false }
+        return rawValue == privateFile.rawValue || rawValue == prereleasePrivateFileRawValue
+    }
+
     var description: String {
         switch self {
         case .privateMessage: return "privateMessage"
@@ -93,6 +116,8 @@ enum NoisePayloadType: UInt8 {
         case .groupInvite: return "groupInvite"
         case .groupKeyUpdate: return "groupKeyUpdate"
         case .voiceFrame: return "voiceFrame"
+        case .privateFile: return "privateFile"
+        case .authenticatedPeerState: return "authenticatedPeerState"
         case .verifyChallenge: return "verifyChallenge"
         case .verifyResponse: return "verifyResponse"
         case .vouch: return "vouch"

bitchat/Protocols/Packets.swift

@@ -156,6 +156,89 @@ struct AnnouncementPacket {
     }
 }
 
+/// State that is authoritative only because it is carried inside an
+/// established Noise session. The public announce remains useful for
+/// discovery, but its self-signature cannot prove possession of the copied
+/// Noise public key it contains.
+///
+/// Wire format (v1):
+/// `[version=0x01][type][length][value]...`
+/// - TLV `0x01`: canonical minimal little-endian `PeerCapabilities`
+/// - TLV `0x02`: 32-byte Ed25519 signing public key
+///
+/// Unknown TLVs are skipped for forward compatibility. Unknown versions,
+/// duplicates, non-canonical capability fields, and malformed lengths are
+/// rejected without changing authenticated state.
+struct AuthenticatedPeerStatePacket: Equatable {
+    static let currentVersion: UInt8 = 1
+    static let signingPublicKeyLength = 32
+
+    let capabilities: PeerCapabilities
+    let signingPublicKey: Data
+
+    private enum TLVType: UInt8 {
+        case capabilities = 0x01
+        case signingPublicKey = 0x02
+    }
+
+    func encode() -> Data? {
+        guard signingPublicKey.count == Self.signingPublicKeyLength else { return nil }
+        let capabilityBytes = capabilities.encoded()
+        guard !capabilityBytes.isEmpty, capabilityBytes.count <= 8 else { return nil }
+
+        var data = Data([Self.currentVersion])
+        data.append(TLVType.capabilities.rawValue)
+        data.append(UInt8(capabilityBytes.count))
+        data.append(capabilityBytes)
+        data.append(TLVType.signingPublicKey.rawValue)
+        data.append(UInt8(signingPublicKey.count))
+        data.append(signingPublicKey)
+        return data
+    }
+
+    static func decode(from data: Data) -> AuthenticatedPeerStatePacket? {
+        guard data.first == Self.currentVersion else { return nil }
+
+        var offset = 1
+        var capabilities: PeerCapabilities?
+        var signingPublicKey: Data?
+
+        while offset < data.count {
+            guard offset + 2 <= data.count else { return nil }
+            let typeRaw = data[offset]
+            let length = Int(data[offset + 1])
+            offset += 2
+            guard offset + length <= data.count else { return nil }
+            let value = Data(data[offset..<(offset + length)])
+            offset += length
+
+            guard let type = TLVType(rawValue: typeRaw) else {
+                continue
+            }
+            switch type {
+            case .capabilities:
+                guard capabilities == nil,
+                      !value.isEmpty,
+                      value.count <= 8 else { return nil }
+                let decoded = PeerCapabilities(encoded: value)
+                guard decoded.encoded() == value else { return nil }
+                capabilities = decoded
+
+            case .signingPublicKey:
+                guard signingPublicKey == nil,
+                      value.count == Self.signingPublicKeyLength else { return nil }
+                signingPublicKey = value
+            }
+        }
+
+        guard let capabilities, let signingPublicKey else { return nil }
+        return AuthenticatedPeerStatePacket(
+            capabilities: capabilities,
+            signingPublicKey: signingPublicKey
+        )
+    }
+}
+
 struct PrivateMessagePacket {
     let messageID: String
     let content: String

bitchat/Protocols/PeerCapabilities+Local.swift

@@ -3,5 +3,5 @@ import BitFoundation
 extension PeerCapabilities {
     /// Capabilities this build advertises in its announce packets.
     /// Each feature adds its bit here when it ships.
-    static let localSupported: PeerCapabilities = [.vouch, .prekeys, .groups]
+    static let localSupported: PeerCapabilities = [.vouch, .prekeys, .groups, .privateMedia]
 }

bitchat/Services/BLE/BLEAnnounceHandler.swift

@@ -16,6 +16,9 @@ struct BLEAnnounceHandlerEnvironment {
     let now: () -> Date
     /// Noise public key already recorded for the peer, if any (registry read).
     let existingNoisePublicKey: (PeerID) -> Data?
+    /// Ed25519 key previously bound to this Noise identity by an authenticated
+    /// peer-state payload, if any (persistent identity-state read).
+    let authenticatedSigningPublicKey: (_ noisePublicKey: Data) -> Data?
     /// Verifies the packet signature against the announced signing key.
     let verifySignature: (_ packet: BitchatPacket, _ signingPublicKey: Data) -> Bool
     /// Direct link state for the peer (BLE-queue read).
@@ -130,11 +133,21 @@ final class BLEAnnounceHandler {
             hasSignature: hasSignature,
             signatureValid: signatureValid,
             existingNoisePublicKey: existingNoisePublicKey,
-            announcedNoisePublicKey: announcement.noisePublicKey
+            announcedNoisePublicKey: announcement.noisePublicKey,
+            authenticatedSigningPublicKey: env.authenticatedSigningPublicKey(
+                announcement.noisePublicKey
+            ),
+            announcedSigningPublicKey: announcement.signingPublicKey
         )
         if case .reject(.keyMismatch) = trustDecision {
             SecureLogger.warning("⚠️ Announce key mismatch for \(peerID.id.prefix(8))… — keeping unverified", category: .security)
         }
+        if case .reject(.authenticatedSigningKeyMismatch) = trustDecision {
+            SecureLogger.warning(
+                "⚠️ Announce signing-key replacement rejected for Noise-authenticated peer \(peerID.id.prefix(8))…",
+                category: .security
+            )
+        }
         let verifiedAnnounce = trustDecision.isVerified
 
         var isNewPeer = false

bitchat/Services/BLE/BLEAnnounceHandlingPolicy.swift

@@ -56,6 +56,7 @@ enum BLEAnnounceTrustRejection: Equatable {
     case missingSignature
     case invalidSignature
     case keyMismatch
+    case authenticatedSigningKeyMismatch
 }
 
 enum BLEAnnounceTrustDecision: Equatable {
@@ -72,12 +73,19 @@ enum BLEAnnounceTrustPolicy {
         hasSignature: Bool,
         signatureValid: Bool,
         existingNoisePublicKey: Data?,
-        announcedNoisePublicKey: Data
+        announcedNoisePublicKey: Data,
+        authenticatedSigningPublicKey: Data? = nil,
+        announcedSigningPublicKey: Data? = nil
     ) -> BLEAnnounceTrustDecision {
         if let existingNoisePublicKey, existingNoisePublicKey != announcedNoisePublicKey {
             return .reject(.keyMismatch)
         }
 
+        if let authenticatedSigningPublicKey,
+           announcedSigningPublicKey != authenticatedSigningPublicKey {
+            return .reject(.authenticatedSigningKeyMismatch)
+        }
+
         guard hasSignature else {
             return .reject(.missingSignature)
         }

bitchat/Services/BLE/BLEFileTransferHandler.swift

@@ -16,6 +16,8 @@ struct BLEFileTransferHandlerEnvironment {
     let peersSnapshot: () -> [PeerID: BLEPeerInfo]
     /// Verifies a packet's signature against a candidate signing key (registry path).
     let verifyPacketSignature: (_ packet: BitchatPacket, _ signingPublicKey: Data) -> Bool
+    /// Local signing key used to authenticate our own gossip-sync replays.
+    let localSigningPublicKey: () -> Data
     /// Resolves a display name from a verified packet signature for peers missing from the registry.
     let signedSenderDisplayName: (_ packet: BitchatPacket, _ peerID: PeerID) -> String?
     /// Tracks the broadcast file packet for gossip sync.
@@ -46,54 +48,105 @@ final class BLEFileTransferHandler {
         self.environment = environment
     }
 
-    /// Returns `false` when the packet fails sender authentication and must
-    /// not be relayed onward. Every other outcome returns `true`: files
-    /// directed to another peer are forwarded untouched, and local-only drops
-    /// (malformed payload, quota, save failure) don't affect multi-hop
-    /// delivery to nodes that may handle them fine.
+    /// Returns `false` when the raw packet fails sender authentication (or is
+    /// a live self-echo) and must not be relayed onward. Authentication runs
+    /// before the routing decision, so a forged directed packet cannot use a
+    /// node that is not its recipient as an unsigned forwarding hop.
     @discardableResult
     func handle(_ packet: BitchatPacket, from peerID: PeerID) -> Bool {
         let env = environment
-        if BLEFileTransferPolicy.isSelfEcho(packet: packet, from: peerID, localPeerID: env.localPeerID()) { return true }
-
-        guard let deliveryPlan = BLEFileTransferPolicy.deliveryPlan(packet: packet, localPeerID: env.localPeerID()) else {
-            return true
-        }
-
+        let localPeerID = env.localPeerID()
         let peersSnapshot = env.peersSnapshot()
-        guard let senderNickname = resolveSenderNickname(
+
+        guard let senderNickname = authenticatedRawSenderNickname(
             packet: packet,
             from: peerID,
-            isBroadcast: !deliveryPlan.isPrivateMessage,
             peers: peersSnapshot,
             env: env
         ) else {
-            SecureLogger.warning("🚫 Dropping file transfer from unverified or unknown peer \(peerID.id.prefix(8))…", category: .security)
+            SecureLogger.warning("🚫 Dropping raw file transfer with missing/invalid signature from \(peerID.id.prefix(8))…", category: .security)
             return false
         }
 
+        if BLEFileTransferPolicy.isSelfEcho(packet: packet, from: peerID, localPeerID: localPeerID) {
+            return false
+        }
+
+        guard let deliveryPlan = BLEFileTransferPolicy.deliveryPlan(packet: packet, localPeerID: localPeerID) else {
+            return true
+        }
+
         if deliveryPlan.shouldTrackForSync {
             env.trackPacketSeen(packet)
         }
 
+        _ = storeIncomingPayload(
+            packet.payload,
+            from: peerID,
+            senderNickname: senderNickname,
+            timestamp: Date(timeIntervalSince1970: Double(packet.timestamp) / 1000),
+            isPrivate: deliveryPlan.isPrivateMessage,
+            env: env
+        )
+        // Once authenticated, a local decode/quota/save failure is not proof
+        // that downstream nodes should be denied the valid signed packet.
+        return true
+    }
+
+    /// Accepts a file packet only after it has been authenticated and
+    /// decrypted by the peer's Noise session. The inner packet deliberately
+    /// has no redundant signature: Noise supplies sender authentication and
+    /// confidentiality, while this handler retains the same validation,
+    /// quota, persistence, and UI-delivery behavior as public files.
+    @discardableResult
+    func handlePrivatePayload(_ payload: Data, from peerID: PeerID, timestamp: Date) -> Bool {
+        let env = environment
+        let peers = env.peersSnapshot()
+        let senderNickname = BLEPeerSenderDisplayName.resolveKnownPeer(
+            peerID: peerID,
+            localPeerID: env.localPeerID(),
+            localNickname: env.localNickname(),
+            peers: peers,
+            allowConnectedUnverified: true
+        ) ?? BLEPeerSenderDisplayName.anonymousNickname(for: peerID)
+
+        return storeIncomingPayload(
+            payload,
+            from: peerID,
+            senderNickname: senderNickname,
+            timestamp: timestamp,
+            isPrivate: true,
+            env: env
+        )
+    }
+
+    private func storeIncomingPayload(
+        _ payload: Data,
+        from peerID: PeerID,
+        senderNickname: String,
+        timestamp: Date,
+        isPrivate: Bool,
+        env: BLEFileTransferHandlerEnvironment
+    ) -> Bool {
+
         let filePacket: BitchatFilePacket
         let mime: MimeType
-        switch BLEIncomingFileValidator.validate(payload: packet.payload) {
+        switch BLEIncomingFileValidator.validate(payload: payload) {
         case .success(let acceptance):
             filePacket = acceptance.filePacket
             mime = acceptance.mime
         case .failure(.malformedPayload):
             SecureLogger.error("❌ Failed to decode file transfer payload", category: .session)
-            return true
+            return false
         case .failure(.payloadTooLarge(let bytes)):
             SecureLogger.warning("🚫 Dropping file transfer exceeding size cap (\(bytes) bytes)", category: .security)
-            return true
+            return false
         case .failure(.unsupportedMime(let mimeType, let bytes)):
             SecureLogger.warning("🚫 MIME REJECT: '\(mimeType ?? "<empty>")' not supported. Size=\(bytes)b from \(peerID.id.prefix(8))...", category: .security)
-            return true
+            return false
         case .failure(.magicMismatch(let mime, let bytes, let prefixHex)):
             SecureLogger.warning("🚫 MAGIC REJECT: MIME='\(mime)' size=\(bytes)b prefix=[\(prefixHex)] from \(peerID.id.prefix(8))...", category: .security)
-            return true
+            return false
         }
 
         // BCH-01-002: Enforce storage quota before saving
@@ -106,28 +159,27 @@ final class BLEFileTransferHandler {
             mime.defaultExtension,
             mime.category.rawValue
         ) else {
-            return true
+            return false
         }
 
-        if deliveryPlan.isPrivateMessage {
+        if isPrivate {
             env.updatePeerLastSeen(peerID)
         }
 
-        let ts = Date(timeIntervalSince1970: Double(packet.timestamp) / 1000)
         let message = BitchatMessage(
             sender: senderNickname,
             content: "\(mime.category.messagePrefix)\(destination.lastPathComponent)",
-            timestamp: ts,
+            timestamp: timestamp,
             isRelay: false,
             originalSender: nil,
-            isPrivate: deliveryPlan.isPrivateMessage,
+            isPrivate: isPrivate,
             recipientNickname: nil,
             senderPeerID: peerID,
             // Received messages need an explicit status: BitchatMessage
             // defaults private messages to .sending, which the media views
             // render as an in-flight send (empty reveal mask, disabled tap).
-            deliveryStatus: deliveryPlan.isPrivateMessage
-                ? .delivered(to: env.localNickname(), at: ts)
+            deliveryStatus: isPrivate
+                ? .delivered(to: env.localNickname(), at: timestamp)
                 : nil
         )
 
@@ -137,51 +189,38 @@ final class BLEFileTransferHandler {
         return true
     }
 
-    /// Resolves the authenticated display name for a file transfer's sender.
-    ///
-    /// Directed (private) transfers are addressed to us specifically and keep
-    /// the lenient connected-peer path. Broadcast transfers carry an
-    /// attacker-controllable `senderID` exactly like public messages and public
-    /// voice frames — registry membership alone is NOT proof of identity, so a
-    /// valid packet signature from the claimed sender is required before we
-    /// trust it. Without this, a peer that observed a public voice burst could
-    /// spoof a broadcast `voice_<burstID>.m4a` note under the talker's ID and
-    /// overwrite the signature-verified live bubble with attacker audio.
-    private func resolveSenderNickname(
+    /// Every remaining raw file transfer is signed, regardless of whether it
+    /// is broadcast, addressed to us, or merely passing through. Registry
+    /// signing keys are preferred; persisted identities cover peers that have
+    /// rotated or are not currently present in the registry.
+    private func authenticatedRawSenderNickname(
         packet: BitchatPacket,
         from peerID: PeerID,
-        isBroadcast: Bool,
         peers: [PeerID: BLEPeerInfo],
         env: BLEFileTransferHandlerEnvironment
     ) -> String? {
-        guard isBroadcast else {
+        guard packet.signature != nil else { return nil }
+
+        let localPeerID = env.localPeerID()
+        let candidateKey = peerID == localPeerID
+            ? env.localSigningPublicKey()
+            : peers[peerID]?.signingPublicKey
+        let verifiedWithKnownKey = candidateKey.map {
+            env.verifyPacketSignature(packet, $0)
+        } ?? false
+        let signedDisplayName = verifiedWithKnownKey
+            ? nil
+            : env.signedSenderDisplayName(packet, peerID)
+        guard verifiedWithKnownKey || signedDisplayName != nil else { return nil }
+
         return BLEPeerSenderDisplayName.resolveKnownPeer(
             peerID: peerID,
-                localPeerID: env.localPeerID(),
+            localPeerID: localPeerID,
             localNickname: env.localNickname(),
             peers: peers,
+            // The packet signature authenticates the announced peer; the old
+            // connected-but-unsigned leniency is not involved.
             allowConnectedUnverified: true
-            ) ?? env.signedSenderDisplayName(packet, peerID)
-        }
-
-        // Our own broadcasts replayed back via gossip sync (ttl==0) are
-        // trivially authentic and cannot be verified against the peer registry
-        // or identity cache, so exempt self exactly as `BLEPublicMessageHandler`
-        // does. Verify against the signing key already in the
-        // (synchronously-updated) registry first, then fall back to the
-        // persisted-identity signature lookup for peers not yet cached there.
-        let isSelf = peerID == env.localPeerID()
-        let registrySigningKey = peers[peerID]?.signingPublicKey
-        let verifiedViaRegistry = !isSelf && (registrySigningKey.map { env.verifyPacketSignature(packet, $0) } ?? false)
-        let signedDisplayName = (isSelf || verifiedViaRegistry) ? nil : env.signedSenderDisplayName(packet, peerID)
-        guard isSelf || verifiedViaRegistry || signedDisplayName != nil else { return nil }
-
-        return BLEPeerSenderDisplayName.resolveKnownPeer(
-            peerID: peerID,
-            localPeerID: env.localPeerID(),
-            localNickname: env.localNickname(),
-            peers: peers,
-            allowConnectedUnverified: false
-        ) ?? signedDisplayName
+        ) ?? signedDisplayName ?? BLEPeerSenderDisplayName.anonymousNickname(for: peerID)
     }
 }

bitchat/Services/BLE/BLEFragmentAssemblyBuffer.swift

@@ -201,8 +201,11 @@ struct BLEFragmentAssemblyBuffer {
     }
 
     private static func assemblyLimit(for originalType: UInt8) -> Int {
-        if originalType == MessageType.fileTransfer.rawValue {
+        if originalType == MessageType.fileTransfer.rawValue
+            || originalType == MessageType.noiseEncrypted.rawValue {
             // Allow headroom for TLV metadata and binary framing overhead.
+            // A large noiseEncrypted packet can be an E2E-encrypted private
+            // file; its authenticated plaintext is validated after decrypt.
             return FileTransferLimits.maxFramedFileBytes
         }
 

bitchat/Services/BLE/BLENoisePacketHandler.swift

@@ -2,6 +2,11 @@ import BitFoundation
 import BitLogger
 import Foundation
 
+struct BLENoiseDecryptionResult {
+    let plaintext: Data
+    let sessionGeneration: UUID
+}
+
 /// Narrow environment for `BLENoisePacketHandler`.
 ///
 /// All queue hops (collections barrier writes, main-actor UI notification)
@@ -27,9 +32,16 @@ struct BLENoisePacketHandlerEnvironment {
     /// Updates the registry last-seen timestamp for the peer (async barrier write).
     let updatePeerLastSeen: (PeerID) -> Void
     /// Decrypts an encrypted payload from the peer (crypto).
-    let decrypt: (_ payload: Data, _ peerID: PeerID) throws -> Data
+    let decrypt: (_ payload: Data, _ peerID: PeerID) throws -> BLENoiseDecryptionResult
     /// Clears the peer's Noise session after an unrecoverable decrypt failure (crypto).
     let clearSession: (PeerID) -> Void
+    /// Consumes session-authenticated protocol state inside the transport. It
+    /// must never escape to UI or Nostr payload dispatch.
+    let handleAuthenticatedPeerState: (
+        _ peerID: PeerID,
+        _ payload: Data,
+        _ sessionGeneration: UUID
+    ) -> Void
     /// Delivers `.noisePayloadReceived` to the UI as one main-actor hop.
     let deliverNoisePayload: (
         _ peerID: PeerID,
@@ -49,7 +61,11 @@ final class BLENoisePacketHandler {
         self.environment = environment
     }
 
-    func handleHandshake(_ packet: BitchatPacket, from peerID: PeerID) {
+    /// Returns true when the handshake message was processed successfully.
+    /// Callers use this to distinguish an authenticated replacement completion
+    /// from a rejected candidate while an older session remains established.
+    @discardableResult
+    func handleHandshake(_ packet: BitchatPacket, from peerID: PeerID) -> Bool {
         let env = environment
         // Use NoiseEncryptionService for handshake processing
         if PeerID(hexData: packet.recipientID) == env.localPeerID() {
@@ -72,14 +88,26 @@ final class BLENoisePacketHandler {
 
                 // Session establishment will trigger onPeerAuthenticated callback
                 // which will send any pending messages at the right time
+                return true
+            } catch NoiseSessionError.peerIdentityMismatch {
+                // The candidate was already discarded by the session manager.
+                // Do not let a spoofed claimed ID trigger a fresh outbound
+                // handshake or recreate state for the attacker-selected ID.
+                SecureLogger.warning(
+                    "Rejected Noise handshake whose static key does not match \(peerID.id.prefix(8))…",
+                    category: .security
+                )
+                return false
             } catch {
                 SecureLogger.error("Failed to process handshake: \(error)")
                 // Try initiating a new handshake
                 if !env.hasNoiseSession(peerID) {
                     env.initiateHandshake(peerID)
                 }
+                return false
             }
         }
+        return false
     }
 
     func handleEncrypted(_ packet: BitchatPacket, from peerID: PeerID) {
@@ -98,20 +126,30 @@ final class BLENoisePacketHandler {
         env.updatePeerLastSeen(peerID)
 
         do {
-            let decrypted = try env.decrypt(packet.payload, peerID)
+            let decryption = try env.decrypt(packet.payload, peerID)
+            let decrypted = decryption.plaintext
             guard decrypted.count > 0 else { return }
 
             // First byte indicates the payload type
             let payloadType = decrypted[0]
             let payloadData = decrypted.dropFirst()
 
-            guard let noisePayloadType = NoisePayloadType(rawValue: payloadType) else {
+            guard let noisePayloadType = NoisePayloadType.decoded(rawValue: payloadType) else {
                 SecureLogger.warning("⚠️ Unknown noise payload type: \(payloadType)")
                 return
             }
 
             SecureLogger.debug("🔐 Decrypted noise payload type \(noisePayloadType.description) from \(peerID.id.prefix(8))…", category: .session)
 
+            if noisePayloadType == .authenticatedPeerState {
+                env.handleAuthenticatedPeerState(
+                    peerID,
+                    Data(payloadData),
+                    decryption.sessionGeneration
+                )
+                return
+            }
+
             let ts = Date(timeIntervalSince1970: Double(packet.timestamp) / 1000)
             env.deliverNoisePayload(peerID, noisePayloadType, Data(payloadData), ts)
         } catch NoiseEncryptionError.sessionNotEstablished {

bitchat/Services/BLE/BLENoisePayloadFactory.swift

@@ -17,6 +17,16 @@ enum BLENoisePayloadFactory {
         typedPayload(.delivered, payload: Data(messageID.utf8))
     }
 
+    static func privateFile(_ filePacket: BitchatFilePacket) -> Data? {
+        guard let payload = filePacket.encode() else { return nil }
+        return typedPayload(.privateFile, payload: payload)
+    }
+
+    static func authenticatedPeerState(_ state: AuthenticatedPeerStatePacket) -> Data? {
+        guard let payload = state.encode() else { return nil }
+        return typedPayload(.authenticatedPeerState, payload: payload)
+    }
+
     static func typedPayload(_ type: NoisePayloadType, payload: Data) -> Data {
         var typed = Data([type.rawValue])
         typed.append(payload)

bitchat/Services/BLE/BLENoiseSessionQueues.swift

@@ -6,9 +6,16 @@ struct BLEPendingPrivateMessage: Equatable {
     let messageID: String
 }
 
+struct BLEPendingTypedPayload: Equatable {
+    let payload: Data
+    /// Present for app-initiated media so handshake queuing preserves the
+    /// fragment scheduler's progress/cancellation identity.
+    let transferId: String?
+}
+
 struct BLENoiseSessionQueues {
     private var privateMessagesByPeerID: [PeerID: [BLEPendingPrivateMessage]] = [:]
-    private var typedPayloadsByPeerID: [PeerID: [Data]] = [:]
+    private var typedPayloadsByPeerID: [PeerID: [BLEPendingTypedPayload]] = [:]
 
     var isEmpty: Bool {
         privateMessagesByPeerID.isEmpty && typedPayloadsByPeerID.isEmpty
@@ -34,13 +41,35 @@ struct BLENoiseSessionQueues {
         privateMessagesByPeerID[peerID, default: []].insert(contentsOf: messages, at: 0)
     }
 
-    mutating func appendTypedPayload(_ payload: Data, for peerID: PeerID) {
-        typedPayloadsByPeerID[peerID, default: []].append(payload)
+    mutating func appendTypedPayload(_ payload: Data, transferId: String? = nil, for peerID: PeerID) {
+        typedPayloadsByPeerID[peerID, default: []].append(
+            BLEPendingTypedPayload(payload: payload, transferId: transferId)
+        )
     }
 
-    mutating func takeTypedPayloads(for peerID: PeerID) -> [Data] {
+    mutating func takeTypedPayloads(for peerID: PeerID) -> [BLEPendingTypedPayload] {
         let payloads = typedPayloadsByPeerID[peerID] ?? []
         typedPayloadsByPeerID.removeValue(forKey: peerID)
         return payloads
     }
+
+    func containsTypedPayload(transferId: String) -> Bool {
+        typedPayloadsByPeerID.values.contains { payloads in
+            payloads.contains { $0.transferId == transferId }
+        }
+    }
+
+    @discardableResult
+    mutating func removeTypedPayload(transferId: String) -> Bool {
+        for peerID in Array(typedPayloadsByPeerID.keys) {
+            guard var payloads = typedPayloadsByPeerID[peerID],
+                  let index = payloads.firstIndex(where: { $0.transferId == transferId }) else {
+                continue
+            }
+            payloads.remove(at: index)
+            typedPayloadsByPeerID[peerID] = payloads.isEmpty ? nil : payloads
+            return true
+        }
+        return false
+    }
 }

bitchat/Services/BLE/BLEOutboundFragmentPlanner.swift

@@ -17,6 +17,9 @@ struct BLEOutboundFragmentPlan {
 }
 
 enum BLEOutboundFragmentPlanner {
+    /// Current Android receivers reject fragment sets above 256. Private
+    /// media v1 treats that deployed ceiling as a cross-platform contract.
+    static let privateMediaV1MaxFragments = 256
     private static let minimumChunkSize = 64
     private static let fragmentIDLength = 8
 
@@ -71,6 +74,10 @@ enum BLEOutboundFragmentPlanner {
         )
     }
 
+    static func isPrivateMediaV1Compatible(_ plan: BLEOutboundFragmentPlan) -> Bool {
+        plan.totalFragments <= privateMediaV1MaxFragments
+    }
+
     private static func sizingPolicy(
         for packet: BitchatPacket,
         requestedMaxChunk: Int?,

bitchat/Services/BLE/BLEOutboundFragmentTransferScheduler.swift

@@ -29,8 +29,9 @@ struct BLEOutboundFragmentTransferRequest {
     }
 
     var resolvedTransferId: String? {
+        if let transferId { return transferId }
         guard packet.type == MessageType.fileTransfer.rawValue else { return nil }
-        return transferId ?? packet.payload.sha256Hex()
+        return packet.payload.sha256Hex()
     }
 
     /// Content identity independent of the caller-chosen transfer ID: the

bitchat/Services/BLE/BLEPeerRegistry.swift

@@ -10,6 +10,9 @@ struct BLEPeerInfo: Equatable {
     var isVerifiedNickname: Bool
     var lastSeen: Date
     var capabilities: PeerCapabilities = []
+    /// Distinguishes an old client that omitted the capabilities TLV from a
+    /// modern client that explicitly advertised a set without a given bit.
+    var capabilitiesWereExplicitlyAdvertised: Bool = false
     /// Rendezvous cell from the peer's announce when it advertises `.bridge`.
     var bridgeGeohash: String?
 }
@@ -114,6 +117,10 @@ struct BLEPeerRegistry {
         peers[peerID.toShort()]?.capabilities ?? []
     }
 
+    func capabilitiesWereExplicitlyAdvertised(for peerID: PeerID) -> Bool {
+        peers[peerID.toShort()]?.capabilitiesWereExplicitlyAdvertised == true
+    }
+
     /// Peers whose last verified announce advertised the given capability.
     func peers(advertising capability: PeerCapabilities) -> [PeerID] {
         peers.values.filter { $0.capabilities.contains(capability) }.map(\.peerID)
@@ -174,6 +181,14 @@ struct BLEPeerRegistry {
         peers[peerID] = peer
     }
 
+    /// Replaces the announcement signing key only after the surrounding Noise
+    /// session proved possession of this peer's static key.
+    mutating func bindAuthenticatedSigningPublicKey(_ key: Data, for peerID: PeerID) {
+        guard var peer = peers[peerID.toShort()] else { return }
+        peer.signingPublicKey = key
+        peers[peer.peerID] = peer
+    }
+
     mutating func upsertVerifiedAnnounce(
         peerID: PeerID,
         nickname: String,
@@ -181,7 +196,7 @@ struct BLEPeerRegistry {
         signingPublicKey: Data?,
         isConnected: Bool,
         now: Date,
-        capabilities: PeerCapabilities = [],
+        capabilities: PeerCapabilities? = nil,
         bridgeGeohash: String? = nil
     ) -> BLEPeerAnnounceUpdate {
         let existing = peers[peerID]
@@ -199,7 +214,8 @@ struct BLEPeerRegistry {
             signingPublicKey: signingPublicKey,
             isVerifiedNickname: true,
             lastSeen: now,
-            capabilities: capabilities,
+            capabilities: capabilities ?? [],
+            capabilitiesWereExplicitlyAdvertised: capabilities != nil,
             bridgeGeohash: bridgeGeohash
         )
 

bitchat/Services/NoiseEncryptionService.swift

@@ -165,7 +165,6 @@ final class NoiseEncryptionService {
     // Peer fingerprints (SHA256 hash of static public key)
     private var peerFingerprints: [PeerID: String] = [:]
     private var fingerprintToPeerID: [String: PeerID] = [:]
-    
     // Thread safety
     private let serviceQueue = DispatchQueue(label: "chat.bitchat.noise.service", attributes: .concurrent)
     
@@ -183,12 +182,18 @@ final class NoiseEncryptionService {
     
     // Callbacks
     private var onPeerAuthenticatedHandlers: [((PeerID, String) -> Void)] = [] // Array of handlers for peer authentication
+    private var onPeerAuthenticatedWithGenerationHandlers: [((PeerID, String, UUID) -> Void)] = []
     var onHandshakeRequired: ((PeerID) -> Void)? // peerID needs handshake
+    /// Automatic rekey removed the old session and produced XX message 1.
+    /// The transport must clear session-scoped state and put these exact bytes
+    /// on the wire; merely reporting "handshake required" strands the partial
+    /// initiator session because a second initiate call sees it already exists.
+    var onRekeyHandshakeReady: ((_ peerID: PeerID, _ message: Data) -> Void)?
     
     // Add a handler for peer authentication
     func addOnPeerAuthenticatedHandler(_ handler: @escaping (PeerID, String) -> Void) {
-        serviceQueue.async(flags: .barrier) { [weak self] in
-            self?.onPeerAuthenticatedHandlers.append(handler)
+        serviceQueue.sync(flags: .barrier) {
+            onPeerAuthenticatedHandlers.append(handler)
         }
     }
     
@@ -202,6 +207,18 @@ final class NoiseEncryptionService {
         }
     }
 
+    /// Generation-aware authentication notifications are used by protocols
+    /// whose state must be bound to one exact Noise transport session.
+    var onPeerAuthenticatedWithGeneration: ((PeerID, String, UUID) -> Void)? {
+        get { nil }
+        set {
+            guard let handler = newValue else { return }
+            serviceQueue.sync(flags: .barrier) {
+                onPeerAuthenticatedWithGenerationHandlers.append(handler)
+            }
+        }
+    }
+    
     init(keychain: KeychainManagerProtocol) {
         self.keychain = keychain
         self.localPrekeys = LocalPrekeyStore(keychain: keychain)
@@ -295,8 +312,12 @@ final class NoiseEncryptionService {
         self.sessionManager = NoiseSessionManager(localStaticKey: staticIdentityKey, keychain: keychain)
 
         // Set up session callbacks
-        sessionManager.onSessionEstablished = { [weak self] peerID, remoteStaticKey in
-            self?.handleSessionEstablished(peerID: peerID, remoteStaticKey: remoteStaticKey)
+        sessionManager.onSessionEstablished = { [weak self] peerID, remoteStaticKey, generation in
+            self?.handleSessionEstablished(
+                peerID: peerID,
+                remoteStaticKey: remoteStaticKey,
+                sessionGeneration: generation
+            )
         }
 
         // Start session maintenance timer
@@ -726,10 +747,55 @@ final class NoiseEncryptionService {
         return try sessionManager.encrypt(data, for: peerID)
     }
 
+    /// Encrypts a finalized private-media packet. Ordinary Noise application
+    /// messages retain the 64 KiB ceiling; this purpose-specific path permits
+    /// the bounded `BitchatFilePacket` envelope and refuses every other typed
+    /// payload so the larger allocation budget cannot become a generic bypass.
+    func encryptPrivateFilePayload(
+        _ data: Data,
+        for peerID: PeerID,
+        sessionGeneration: UUID? = nil
+    ) throws -> Data {
+        guard NoisePayloadType.isPrivateFile(rawValue: data.first),
+              NoiseSecurityValidator.validatePrivateFileMessageSize(data) else {
+            throw NoiseSecurityError.messageTooLarge
+        }
+
+        guard rateLimiter.allowMessage(from: peerID) else {
+            throw NoiseSecurityError.rateLimitExceeded
+        }
+
+        guard hasEstablishedSession(with: peerID) else {
+            onHandshakeRequired?(peerID)
+            throw NoiseEncryptionError.handshakeRequired
+        }
+
+        // `maxPrivateFilePlaintextSize` already subtracts the cipher's fixed
+        // nonce/tag overhead, so the result is bounded without a second copy.
+        if let sessionGeneration {
+            return try sessionManager.encrypt(
+                data,
+                for: peerID,
+                expectedSessionGeneration: sessionGeneration
+            )
+        }
+        return try sessionManager.encrypt(data, for: peerID)
+    }
+    
     /// Decrypt data from a specific peer
     func decrypt(_ data: Data, from peerID: PeerID) throws -> Data {
-        // Validate message size
-        guard NoiseSecurityValidator.validateMessageSize(data) else {
+        try decryptWithSessionGeneration(data, from: peerID).plaintext
+    }
+
+    func decryptWithSessionGeneration(
+        _ data: Data,
+        from peerID: PeerID
+    ) throws -> (plaintext: Data, sessionGeneration: UUID) {
+        // Standard transport ciphertext has 20 bytes of nonce/tag overhead.
+        // A larger candidate is admitted only up to the framed-file ceiling;
+        // after authenticated decryption it must prove it is `.privateFile`.
+        let isStandardCiphertext = NoiseSecurityValidator.validateCiphertextSize(data)
+        guard isStandardCiphertext || NoiseSecurityValidator.validatePrivateFileCiphertextSize(data) else {
             throw NoiseSecurityError.messageTooLarge
         }
         
@@ -743,7 +809,14 @@ final class NoiseEncryptionService {
             throw NoiseEncryptionError.sessionNotEstablished
         }
         
-        return try sessionManager.decrypt(data, from: peerID)
+        let result = try sessionManager.decryptWithSessionGeneration(data, from: peerID)
+        if !isStandardCiphertext {
+            guard NoisePayloadType.isPrivateFile(rawValue: result.plaintext.first),
+                  NoiseSecurityValidator.validatePrivateFileMessageSize(result.plaintext) else {
+                throw NoiseSecurityError.messageTooLarge
+            }
+        }
+        return result
     }
     
     // MARK: - Peer Management
@@ -755,6 +828,25 @@ final class NoiseEncryptionService {
         }
     }
 
+    func sessionGeneration(for peerID: PeerID) -> UUID? {
+        sessionManager.sessionGeneration(for: peerID)
+    }
+
+    /// Runs `body` while holding a read lease on the exact session generation.
+    /// Session insertion, replacement, and removal use the same manager
+    /// barrier, so they cannot interleave with an authenticated-state commit.
+    func withCurrentSessionGeneration<Result>(
+        for peerID: PeerID,
+        expected: UUID,
+        _ body: () -> Result
+    ) -> Result? {
+        sessionManager.withCurrentSessionGeneration(
+            for: peerID,
+            expected: expected,
+            body
+        )
+    }
+
     func clearEphemeralStateForPanic() {
         sessionManager.removeAllSessions()
         serviceQueue.sync(flags: .barrier) {
@@ -777,24 +869,36 @@ final class NoiseEncryptionService {
     
     // MARK: - Private Helpers
     
-    private func handleSessionEstablished(peerID: PeerID, remoteStaticKey: Curve25519.KeyAgreement.PublicKey) {
+    private func handleSessionEstablished(
+        peerID: PeerID,
+        remoteStaticKey: Curve25519.KeyAgreement.PublicKey,
+        sessionGeneration: UUID
+    ) {
         // Calculate fingerprint
         let fingerprint = remoteStaticKey.rawRepresentation.sha256Fingerprint()
         
-        // Store fingerprint mapping
-        serviceQueue.sync(flags: .barrier) {
+        // Registering handlers is synchronous, and this barrier snapshots them
+        // with the fingerprint update. Invoke the snapshot outside the queue:
+        // parallel Swift Testing workers must not block behind queued callback
+        // registration or allow a handler to re-enter serviceQueue.
+        let handlers: (
+            generationAware: [(PeerID, String, UUID) -> Void],
+            legacy: [(PeerID, String) -> Void]
+        ) = serviceQueue.sync(flags: .barrier) {
             peerFingerprints[peerID] = fingerprint
             fingerprintToPeerID[fingerprint] = peerID
+            return (onPeerAuthenticatedWithGenerationHandlers, onPeerAuthenticatedHandlers)
         }
         
         // Log security event
         SecureLogger.info(.handshakeCompleted(peerID: peerID.id))
         
-        // Notify all handlers about authentication
-        serviceQueue.async { [weak self] in
-            self?.onPeerAuthenticatedHandlers.forEach { handler in
-                handler(peerID, fingerprint)
+        // Notify all handlers about authentication.
+        handlers.generationAware.forEach { handler in
+            handler(peerID, fingerprint, sessionGeneration)
         }
+        handlers.legacy.forEach { handler in
+            handler(peerID, fingerprint)
         }
     }
         
@@ -815,20 +919,27 @@ final class NoiseEncryptionService {
         let sessionsNeedingRekey = sessionManager.getSessionsNeedingRekey()
         
         for (peerID, needsRekey) in sessionsNeedingRekey where needsRekey {
-            
-            // Attempt to rekey the session
             do {
-                try sessionManager.initiateRekey(for: peerID)
-                SecureLogger.debug("Key rotation initiated for peer: \(peerID)", category: .security)
-                
-                // Signal that handshake is needed
-                onHandshakeRequired?(peerID)
+                try initiateAutomaticRekey(for: peerID)
             } catch {
                 SecureLogger.error(error, context: "Failed to initiate rekey for peer: \(peerID)", category: .session)
             }
         }
     }
 
+    private func initiateAutomaticRekey(for peerID: PeerID) throws {
+        let handshakeMessage = try sessionManager.initiateRekey(for: peerID)
+        SecureLogger.debug("Key rotation initiated for peer: \(peerID)", category: .security)
+        onRekeyHandshakeReady?(peerID, handshakeMessage)
+        onHandshakeRequired?(peerID)
+    }
+
+    #if DEBUG
+    func _test_initiateAutomaticRekey(for peerID: PeerID) throws {
+        try initiateAutomaticRekey(for: peerID)
+    }
+    #endif
+    
     deinit {
         stopRekeyTimer()
     }

bitchat/Services/TransferProgressManager.swift

@@ -11,6 +11,7 @@ final class TransferProgressManager {
         case updated(id: String, sentFragments: Int, totalFragments: Int)
         case completed(id: String, totalFragments: Int)
         case cancelled(id: String, sentFragments: Int, totalFragments: Int)
+        case rejected(id: String, reason: String)
     }
 
     private let subject = PassthroughSubject<Event, Never>()
@@ -49,6 +50,17 @@ final class TransferProgressManager {
         }
     }
 
+    /// Fails a preflight check while keeping the outgoing placeholder visible
+    /// with an actionable reason instead of treating policy/size rejection as
+    /// a user cancellation.
+    func rejectBeforeStart(id: String, reason: String) {
+        queue.async(flags: .barrier) { [weak self] in
+            guard let self = self else { return }
+            self.states.removeValue(forKey: id)
+            self.subject.send(.rejected(id: id, reason: reason))
+        }
+    }
+
     func snapshot(id: String) -> (sent: Int, total: Int)? {
         var result: (sent: Int, total: Int)?
         queue.sync {

bitchat/Services/Transport.swift

@@ -83,6 +83,20 @@ enum TransportEvent: @unchecked Sendable {
     case bluetoothStateUpdated(CBManagerState)
 }
 
+/// Downgrade-safe decision for a private-media recipient. Callers ask before
+/// prompting, and BLEService checks again when it consumes any one-shot
+/// legacy consent.
+enum PrivateMediaSendPolicy: Equatable {
+    case encrypted
+    /// A public announce hinted at encrypted media (or a prior authenticated
+    /// pin exists), but this exact Noise session has not yet supplied its
+    /// authenticated peer-state proof. Callers wait boundedly; they must not
+    /// pre-queue encrypted bytes or silently select the legacy path.
+    case awaitingCapabilityProof
+    case legacyRequiresConsent
+    case blockedDowngrade
+}
+
 protocol TransportEventDelegate: AnyObject {
     @MainActor func didReceiveTransportEvent(_ event: TransportEvent)
 }
@@ -163,6 +177,12 @@ protocol Transport: AnyObject {
     func sendDeliveryAck(for messageID: String, to peerID: PeerID)
     func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String)
     func sendFilePrivate(_ packet: BitchatFilePacket, to peerID: PeerID, transferId: String)
+    func sendFilePrivate(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        allowLegacyFallback: Bool
+    )
     func cancelTransfer(_ transferId: String)
 
     // Live voice / push-to-talk (mesh transports only): one encoded
@@ -208,6 +228,11 @@ protocol Transport: AnyObject {
     /// Capabilities the peer advertised in its last verified announce;
     /// empty for peers that predate the capabilities TLV.
     func peerCapabilities(_ peerID: PeerID) -> PeerCapabilities
+    func privateMediaSendPolicy(to peerID: PeerID) -> PrivateMediaSendPolicy
+    func resolvePrivateMediaSendPolicy(
+        to peerID: PeerID,
+        completion: @escaping @MainActor (PrivateMediaSendPolicy) -> Void
+    )
     /// Sends an encoded vouch-attestation batch inside the Noise session.
     func sendVouchAttestations(_ payload: Data, to peerID: PeerID)
     /// Appends a peer-authenticated observer. Unlike
@@ -278,6 +303,16 @@ extension Transport {
     func sendGroupKeyUpdate(_ statePayload: Data, to peerID: PeerID) {}
     func broadcastGroupMessage(_ envelope: Data) {}
     func peerCapabilities(_ peerID: PeerID) -> PeerCapabilities { [] }
+    func privateMediaSendPolicy(to peerID: PeerID) -> PrivateMediaSendPolicy { .blockedDowngrade }
+    func resolvePrivateMediaSendPolicy(
+        to peerID: PeerID,
+        completion: @escaping @MainActor (PrivateMediaSendPolicy) -> Void
+    ) {
+        let policy = privateMediaSendPolicy(to: peerID)
+        Task { @MainActor in
+            completion(policy == .awaitingCapabilityProof ? .blockedDowngrade : policy)
+        }
+    }
     func sendVouchAttestations(_ payload: Data, to peerID: PeerID) {}
     func addPeerAuthenticatedObserver(_ handler: @escaping (PeerID, String) -> Void) {}
     func sendCourierMessage(_ content: String, messageID: String, recipientNoiseKey: Data, via couriers: [PeerID]) -> Bool { false }
@@ -294,6 +329,15 @@ extension Transport {
     func currentMeshTopology() -> MeshTopologySnapshot? { nil }
     func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String) {}
     func sendFilePrivate(_ packet: BitchatFilePacket, to peerID: PeerID, transferId: String) {}
+    func sendFilePrivate(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        allowLegacyFallback: Bool
+    ) {
+        guard !allowLegacyFallback else { return }
+        sendFilePrivate(packet, to: peerID, transferId: transferId)
+    }
     func cancelTransfer(_ transferId: String) {}
 
     func sendMessage(_ content: String, mentions: [String], messageID: String, timestamp: Date) {

bitchat/Services/TransportConfig.swift

@@ -9,6 +9,12 @@ enum TransportConfig {
     static let bleMaxInFlightAssemblies: Int = 128          // Cap concurrent fragment assemblies
     static let bleHighDegreeThreshold: Int = 6              // For adaptive TTL/probabilistic relays
     static let bleMaxConcurrentTransfers: Int = 2           // Limit simultaneous large media sends
+    // Bounded wait for the session-authenticated capability proof used by
+    // private-media migration. Expiry never auto-sends clear bytes; it only
+    // resolves to the existing one-shot consent or downgrade-blocked path.
+    static let privateMediaCapabilityProofTimeoutSeconds: TimeInterval = 5
+    static let privateMediaCapabilityProofPendingPeerCap: Int = 64
+    static let privateMediaCapabilityProofWaitersPerPeerCap: Int = 16
     static let bleFragmentRelayMinDelayMs: Int = 8          // Faster forwarding for media fragments
     static let bleFragmentRelayMaxDelayMs: Int = 25         // Upper jitter bound for fragment relays
     // Fragment relay TTL in sparse graphs; matches messageTTLDefault so media

bitchat/ViewModels/ChatMediaTransferCoordinator.swift

@@ -6,6 +6,19 @@ import Foundation
 import UIKit
 #endif
 
+struct LegacyPrivateMediaConsentRequest: Identifiable, Equatable {
+    let id: UUID
+    let peerID: PeerID
+    let peerName: String
+    let transferId: String
+    let messageID: String
+}
+
+struct PendingLegacyPrivateMediaConsent {
+    let request: LegacyPrivateMediaConsentRequest
+    let completion: @MainActor (Bool) -> Void
+}
+
 /// The narrow surface `ChatMediaTransferCoordinator` needs from its owner.
 ///
 /// Follows the `ChatDeliveryContext` exemplar: the coordinator depends on the
@@ -43,7 +56,24 @@ protocol ChatMediaTransferContext: AnyObject {
     func recordContentKey(_ key: String, timestamp: Date)
 
     // MARK: Mesh file transfer
-    func sendFilePrivate(_ packet: BitchatFilePacket, to peerID: PeerID, transferId: String)
+    func privateMediaSendPolicy(to peerID: PeerID) -> PrivateMediaSendPolicy
+    func resolvePrivateMediaSendPolicy(
+        to peerID: PeerID,
+        completion: @escaping @MainActor (PrivateMediaSendPolicy) -> Void
+    )
+    func requestLegacyPrivateMediaConsent(
+        for peerID: PeerID,
+        transferId: String,
+        messageID: String,
+        completion: @escaping @MainActor (Bool) -> Void
+    )
+    func cancelLegacyPrivateMediaConsent(transferId: String, messageID: String)
+    func sendFilePrivate(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        allowLegacyFallback: Bool
+    )
     func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String)
     func cancelTransfer(_ transferId: String)
 }
@@ -59,8 +89,50 @@ extension ChatViewModel: ChatMediaTransferContext {
     // other contexts or satisfied by existing `ChatViewModel` members. The
     // members below flatten mesh service accesses.
 
-    func sendFilePrivate(_ packet: BitchatFilePacket, to peerID: PeerID, transferId: String) {
-        meshService.sendFilePrivate(packet, to: peerID, transferId: transferId)
+    func privateMediaSendPolicy(to peerID: PeerID) -> PrivateMediaSendPolicy {
+        meshService.privateMediaSendPolicy(to: peerID)
+    }
+
+    func resolvePrivateMediaSendPolicy(
+        to peerID: PeerID,
+        completion: @escaping @MainActor (PrivateMediaSendPolicy) -> Void
+    ) {
+        meshService.resolvePrivateMediaSendPolicy(to: peerID, completion: completion)
+    }
+
+    func requestLegacyPrivateMediaConsent(
+        for peerID: PeerID,
+        transferId: String,
+        messageID: String,
+        completion: @escaping @MainActor (Bool) -> Void
+    ) {
+        enqueueLegacyPrivateMediaConsent(
+            for: peerID,
+            transferId: transferId,
+            messageID: messageID,
+            completion: completion
+        )
+    }
+
+    func cancelLegacyPrivateMediaConsent(transferId: String, messageID: String) {
+        invalidateLegacyPrivateMediaConsent(
+            transferId: transferId,
+            messageID: messageID
+        )
+    }
+
+    func sendFilePrivate(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        allowLegacyFallback: Bool
+    ) {
+        meshService.sendFilePrivate(
+            packet,
+            to: peerID,
+            transferId: transferId,
+            allowLegacyFallback: allowLegacyFallback
+        )
     }
 
     func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String) {
@@ -75,12 +147,19 @@ extension ChatViewModel: ChatMediaTransferContext {
 @MainActor
 final class ChatMediaTransferCoordinator {
     private unowned let context: any ChatMediaTransferContext
+    private let prepareVoiceNotePacket: @Sendable (URL) throws -> BitchatFilePacket
 
     private(set) var transferIdToMessageIDs: [String: [String]] = [:]
     private(set) var messageIDToTransferId: [String: String] = [:]
 
-    init(context: any ChatMediaTransferContext) {
+    init(
+        context: any ChatMediaTransferContext,
+        prepareVoiceNotePacket: @escaping @Sendable (URL) throws -> BitchatFilePacket = {
+            try ChatMediaPreparation.prepareVoiceNotePacket(at: $0)
+        }
+    ) {
         self.context = context
+        self.prepareVoiceNotePacket = prepareVoiceNotePacket
     }
 
     func sendVoiceNote(at url: URL) {
@@ -98,16 +177,28 @@ final class ChatMediaTransferCoordinator {
         )
         let messageID = message.id
         let transferId = makeTransferID(messageID: messageID)
+        // Own the transfer before detached preparation begins. Cancel/delete
+        // must be able to invalidate this exact invocation even while file I/O
+        // is still running off the main actor.
+        registerTransfer(transferId: transferId, messageID: messageID)
+        let prepareVoiceNotePacket = self.prepareVoiceNotePacket
 
         Task.detached(priority: .userInitiated) { [weak self] in
             do {
-                let packet = try ChatMediaPreparation.prepareVoiceNotePacket(at: url)
+                let packet = try prepareVoiceNotePacket(url)
 
                 await MainActor.run { [weak self] in
-                    guard let self else { return }
-                    self.registerTransfer(transferId: transferId, messageID: messageID)
+                    guard let self,
+                          self.isRegisteredTransfer(transferId, messageID: messageID) else {
+                        return
+                    }
                     if let peerID = targetPeer {
-                        self.context.sendFilePrivate(packet, to: peerID, transferId: transferId)
+                        self.beginPrivateMediaSend(
+                            packet,
+                            to: peerID,
+                            transferId: transferId,
+                            messageID: messageID
+                        )
                     } else {
                         self.context.sendFileBroadcast(packet, transferId: transferId)
                     }
@@ -116,13 +207,19 @@ final class ChatMediaTransferCoordinator {
                 SecureLogger.warning("Voice note exceeds size limit (\(size) bytes)", category: .session)
                 try? FileManager.default.removeItem(at: url)
                 await MainActor.run { [weak self] in
-                    guard let self else { return }
+                    guard let self,
+                          self.isRegisteredTransfer(transferId, messageID: messageID) else {
+                        return
+                    }
                     self.handleMediaSendFailure(messageID: messageID, reason: String(localized: "content.delivery.reason.voice_too_large", comment: "Failure reason shown when a voice note exceeds the size limit"))
                 }
             } catch {
                 SecureLogger.error("Voice note send failed: \(error)", category: .session)
                 await MainActor.run { [weak self] in
-                    guard let self else { return }
+                    guard let self,
+                          self.isRegisteredTransfer(transferId, messageID: messageID) else {
+                        return
+                    }
                     self.handleMediaSendFailure(messageID: messageID, reason: String(localized: "content.delivery.reason.voice_send_failed", comment: "Failure reason shown when a voice note could not be sent"))
                 }
             }
@@ -193,7 +290,12 @@ final class ChatMediaTransferCoordinator {
                     let transferId = self.makeTransferID(messageID: messageID)
                     self.registerTransfer(transferId: transferId, messageID: messageID)
                     if let peerID = targetPeer {
-                        self.context.sendFilePrivate(prepared.packet, to: peerID, transferId: transferId)
+                        self.beginPrivateMediaSend(
+                            prepared.packet,
+                            to: peerID,
+                            transferId: transferId,
+                            messageID: messageID
+                        )
                     } else {
                         self.context.sendFileBroadcast(prepared.packet, transferId: transferId)
                     }
@@ -253,17 +355,127 @@ final class ChatMediaTransferCoordinator {
         return message
     }
 
+    private func beginPrivateMediaSend(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        messageID: String
+    ) {
+        continuePrivateMediaSend(
+            packet,
+            to: peerID,
+            transferId: transferId,
+            messageID: messageID,
+            policy: context.privateMediaSendPolicy(to: peerID)
+        )
+    }
+
+    private func continuePrivateMediaSend(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        messageID: String,
+        policy: PrivateMediaSendPolicy
+    ) {
+        switch policy {
+        case .encrypted:
+            context.sendFilePrivate(
+                packet,
+                to: peerID,
+                transferId: transferId,
+                allowLegacyFallback: false
+            )
+
+        case .awaitingCapabilityProof:
+            context.resolvePrivateMediaSendPolicy(to: peerID) { [weak self] resolvedPolicy in
+                guard let self,
+                      self.isRegisteredTransfer(transferId, messageID: messageID) else {
+                    return
+                }
+                guard resolvedPolicy != .awaitingCapabilityProof else {
+                    self.handleMediaSendFailure(
+                        messageID: messageID,
+                        reason: String(
+                            localized: "content.delivery.reason.private_media_capability_unresolved",
+                            defaultValue: "Could not confirm encrypted media support",
+                            comment: "Failure reason when private-media capability negotiation did not resolve"
+                        )
+                    )
+                    return
+                }
+                self.continuePrivateMediaSend(
+                    packet,
+                    to: peerID,
+                    transferId: transferId,
+                    messageID: messageID,
+                    policy: resolvedPolicy
+                )
+            }
+
+        case .legacyRequiresConsent:
+            context.requestLegacyPrivateMediaConsent(
+                for: peerID,
+                transferId: transferId,
+                messageID: messageID
+            ) { [weak self] approved in
+                guard let self else { return }
+                // Consent belongs to this exact placeholder/transfer. A late
+                // dialog callback after cancel/delete must never resurrect it.
+                guard self.messageIDToTransferId[messageID] == transferId,
+                      self.transferIdToMessageIDs[transferId]?.contains(messageID) == true else {
+                    return
+                }
+                guard approved else {
+                    self.handleMediaSendFailure(
+                        messageID: messageID,
+                        reason: String(
+                            localized: "content.delivery.reason.legacy_media_declined",
+                            defaultValue: "Not sent without end-to-end encryption",
+                            comment: "Failure reason after declining the warning for a legacy clear private-media send"
+                        )
+                    )
+                    return
+                }
+                self.context.sendFilePrivate(
+                    packet,
+                    to: peerID,
+                    transferId: transferId,
+                    allowLegacyFallback: true
+                )
+            }
+
+        case .blockedDowngrade:
+            handleMediaSendFailure(
+                messageID: messageID,
+                reason: String(
+                    localized: "content.delivery.reason.private_media_downgrade_blocked",
+                    defaultValue: "Encrypted media required; ask this contact to upgrade",
+                    comment: "Failure reason when a peer that previously supported encrypted media appears to downgrade"
+                )
+            )
+        }
+    }
+
     func registerTransfer(transferId: String, messageID: String) {
         transferIdToMessageIDs[transferId, default: []].append(messageID)
         messageIDToTransferId[messageID] = transferId
     }
 
+    private func isRegisteredTransfer(_ transferId: String, messageID: String) -> Bool {
+        messageIDToTransferId[messageID] == transferId
+            && transferIdToMessageIDs[transferId]?.contains(messageID) == true
+    }
+
     func makeTransferID(messageID: String) -> String {
         "\(messageID)-\(UUID().uuidString)"
     }
 
     func clearTransferMapping(for messageID: String) {
         guard let transferId = messageIDToTransferId.removeValue(forKey: messageID) else { return }
+        context.cancelLegacyPrivateMediaConsent(
+            transferId: transferId,
+            messageID: messageID
+        )
         guard var queue = transferIdToMessageIDs[transferId] else { return }
 
         if !queue.isEmpty {
@@ -298,6 +510,9 @@ final class ChatMediaTransferCoordinator {
             guard let messageID = transferIdToMessageIDs[id]?.first else { return }
             clearTransferMapping(for: messageID)
             context.removeMessage(withID: messageID, cleanupFile: true)
+        case .rejected(let id, let reason):
+            guard let messageID = transferIdToMessageIDs[id]?.first else { return }
+            handleMediaSendFailure(messageID: messageID, reason: reason)
         }
     }
 
@@ -338,6 +553,13 @@ final class ChatMediaTransferCoordinator {
     }
 
     func deleteMediaMessage(messageID: String) {
+        // Delete is also a send cancellation. In particular, an approved
+        // legacy-clear send may still be waiting on BLEService.messageQueue;
+        // removing only the UI mapping would let that deferred work transmit.
+        if let transferId = messageIDToTransferId[messageID],
+           transferIdToMessageIDs[transferId]?.first == messageID {
+            context.cancelTransfer(transferId)
+        }
         clearTransferMapping(for: messageID)
         context.removeMessage(withID: messageID, cleanupFile: true)
     }

bitchat/ViewModels/ChatTransportEventCoordinator.swift

@@ -407,6 +407,13 @@ private extension ChatTransportEventCoordinator {
 
         case .voiceFrame:
             context.handleVoiceFramePayload(from: peerID, payload: payload, timestamp: timestamp)
+
+        case .privateFile, .authenticatedPeerState:
+            // BLEService validates and persists decrypted private files before
+            // emitting a normal `.messageReceived` event, and consumes peer
+            // state inside the transport. Neither payload crosses this
+            // UI-facing typed-payload fallback.
+            break
         }
     }
 

bitchat/ViewModels/ChatViewModel.swift

@@ -347,6 +347,8 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
     @Published var showBluetoothAlert = false
     @Published var bluetoothAlertMessage = ""
     @Published var bluetoothState: CBManagerState = .unknown
+    @Published private(set) var legacyPrivateMediaConsentRequest: LegacyPrivateMediaConsentRequest?
+    private var pendingLegacyPrivateMediaConsents: [PendingLegacyPrivateMediaConsent] = []
 
     private func performDeliveryUpdate(_ update: @escaping @MainActor (ChatDeliveryCoordinator) -> Void) {
         if Thread.isMainThread {
@@ -1156,6 +1158,10 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
     func panicClearAllData() {
         // Messages are processed immediately - nothing to flush
 
+        // Deny and release any clear-media confirmations before identities,
+        // message state, and local files are wiped.
+        cancelAllLegacyPrivateMediaConsents()
+
         // Clear all messages (public timelines and private chats live in the
         // single-writer ConversationStore; the derived `messages` view and
         // the legacy mirror empty with it)
@@ -1804,4 +1810,91 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
         publicConversationCoordinator.sendHapticFeedback(for: message)
     }
 }
+
+@MainActor
+extension ChatViewModel {
+    func enqueueLegacyPrivateMediaConsent(
+        for peerID: PeerID,
+        transferId: String,
+        messageID: String,
+        completion: @escaping @MainActor (Bool) -> Void
+    ) {
+        let request = LegacyPrivateMediaConsentRequest(
+            id: UUID(),
+            peerID: peerID,
+            peerName: nicknameForPeer(peerID),
+            transferId: transferId,
+            messageID: messageID
+        )
+        pendingLegacyPrivateMediaConsents.append(PendingLegacyPrivateMediaConsent(
+            request: request,
+            completion: completion
+        ))
+        if legacyPrivateMediaConsentRequest == nil {
+            legacyPrivateMediaConsentRequest = request
+        }
+    }
+
+    func resolveLegacyPrivateMediaConsent(requestID: UUID, approved: Bool) {
+        // SwiftUI may report both the selected button and the presentation
+        // binding's dismissal. Resolve only the exact request that was shown;
+        // a duplicate callback for it must not consume the next queued send.
+        guard legacyPrivateMediaConsentRequest?.id == requestID,
+              pendingLegacyPrivateMediaConsents.first?.request.id == requestID else {
+            return
+        }
+        let resolved = pendingLegacyPrivateMediaConsents.removeFirst()
+        // Drive the boolean presentation state through false before showing
+        // the next queued per-send warning. Otherwise SwiftUI sees true→true,
+        // closes the first dialog, and never presents the second.
+        legacyPrivateMediaConsentRequest = nil
+        resolved.completion(approved)
+        presentNextLegacyPrivateMediaConsentDeferred()
+    }
+
+    func invalidateLegacyPrivateMediaConsent(transferId: String, messageID: String) {
+        let invalidatedIDs = Set(
+            pendingLegacyPrivateMediaConsents.compactMap { pending -> UUID? in
+                let request = pending.request
+                return request.transferId == transferId && request.messageID == messageID
+                    ? request.id
+                    : nil
+            }
+        )
+        guard !invalidatedIDs.isEmpty else { return }
+
+        pendingLegacyPrivateMediaConsents.removeAll {
+            invalidatedIDs.contains($0.request.id)
+        }
+        if let currentID = legacyPrivateMediaConsentRequest?.id,
+           invalidatedIDs.contains(currentID) {
+            legacyPrivateMediaConsentRequest = nil
+            presentNextLegacyPrivateMediaConsentDeferred()
+        }
+    }
+
+    func cancelAllLegacyPrivateMediaConsents() {
+        let pending = pendingLegacyPrivateMediaConsents
+        pendingLegacyPrivateMediaConsents.removeAll()
+        legacyPrivateMediaConsentRequest = nil
+        for item in pending {
+            item.completion(false)
+        }
+    }
+
+    private func presentNextLegacyPrivateMediaConsentDeferred() {
+        guard legacyPrivateMediaConsentRequest == nil,
+              let nextRequestID = pendingLegacyPrivateMediaConsents.first?.request.id else {
+            return
+        }
+        DispatchQueue.main.async { [weak self] in
+            guard let self,
+                  self.legacyPrivateMediaConsentRequest == nil,
+                  self.pendingLegacyPrivateMediaConsents.first?.request.id == nextRequestID else {
+                return
+            }
+            self.legacyPrivateMediaConsentRequest = self.pendingLegacyPrivateMediaConsents[0].request
+        }
+    }
+}
 // End of ChatViewModel class

bitchat/ViewModels/NostrInboundPipeline.swift

@@ -307,7 +307,7 @@ final class NostrInboundPipeline {
         // claiming to be group traffic over Nostr is ignored.
         // Live voice is mesh-only: latency and relay cost make it
         // meaningless over Nostr.
-        case .verifyChallenge, .verifyResponse, .groupInvite, .groupKeyUpdate, .vouch, .voiceFrame:
+        case .verifyChallenge, .verifyResponse, .groupInvite, .groupKeyUpdate, .vouch, .voiceFrame, .privateFile, .authenticatedPeerState:
             break
         }
     }
@@ -363,7 +363,7 @@ final class NostrInboundPipeline {
         // claiming to be group traffic over Nostr is ignored.
         // Live voice is mesh-only: latency and relay cost make it
         // meaningless over Nostr.
-        case .verifyChallenge, .verifyResponse, .groupInvite, .groupKeyUpdate, .vouch, .voiceFrame:
+        case .verifyChallenge, .verifyResponse, .groupInvite, .groupKeyUpdate, .vouch, .voiceFrame, .privateFile, .authenticatedPeerState:
             break
         }
     }
@@ -446,7 +446,7 @@ final class NostrInboundPipeline {
                         // in v1; group traffic over Nostr is ignored.
                         // Live voice is mesh-only: latency and relay cost make it
                         // meaningless over Nostr.
-                        case .verifyChallenge, .verifyResponse, .groupInvite, .groupKeyUpdate, .vouch, .voiceFrame:
+                        case .verifyChallenge, .verifyResponse, .groupInvite, .groupKeyUpdate, .vouch, .voiceFrame, .privateFile, .authenticatedPeerState:
                             break
                         }
                     }

bitchat/Views/ContentSheetViews.swift

@@ -36,6 +36,7 @@ struct ContentPeopleSheetView: View {
     #endif
 
     var body: some View {
+        let legacyConsentRequest = conversationUIModel.legacyPrivateMediaConsentRequest
         NavigationStack {
             Group {
                 if privateConversationModel.selectedPeerID != nil {
@@ -97,6 +98,63 @@ struct ContentPeopleSheetView: View {
         }
         .themedSheetBackground()
         .foregroundColor(palette.primary)
+        .confirmationDialog(
+            String(
+                localized: "content.private_media.legacy_warning.title",
+                defaultValue: "Send without end-to-end encryption?",
+                comment: "Title warning before sending private media to an older client in a clear signed envelope"
+            ),
+            isPresented: Binding(
+                get: { legacyConsentRequest != nil },
+                set: { isPresented in
+                    if !isPresented, let requestID = legacyConsentRequest?.id {
+                        conversationUIModel.resolveLegacyPrivateMediaConsent(
+                            requestID: requestID,
+                            approved: false
+                        )
+                    }
+                }
+            ),
+            titleVisibility: .visible
+        ) {
+            Button(
+                String(
+                    localized: "content.private_media.legacy_warning.send",
+                    defaultValue: "send visible file",
+                    comment: "Destructive confirmation action for one legacy clear private-media send"
+                ),
+                role: .destructive
+            ) {
+                if let requestID = legacyConsentRequest?.id {
+                    conversationUIModel.resolveLegacyPrivateMediaConsent(
+                        requestID: requestID,
+                        approved: true
+                    )
+                }
+            }
+            Button("common.cancel", role: .cancel) {
+                if let requestID = legacyConsentRequest?.id {
+                    conversationUIModel.resolveLegacyPrivateMediaConsent(
+                        requestID: requestID,
+                        approved: false
+                    )
+                }
+            }
+        } message: {
+            if let request = legacyConsentRequest {
+                Text(
+                    String(
+                        format: String(
+                            localized: "content.private_media.legacy_warning.message",
+                            defaultValue: "%@'s client does not advertise encrypted private media. This file will be signed but not end-to-end encrypted, so mesh relays can see it. Send this file anyway?",
+                            comment: "Warning explaining the confidentiality loss for one legacy private-media send; parameter is the peer name"
+                        ),
+                        locale: .current,
+                        request.peerName
+                    )
+                )
+            }
+        }
         #if os(macOS)
         .frame(minWidth: 420, minHeight: 520)
         #endif

bitchatTests/BLEServiceCoreTests.swift

@@ -99,6 +99,95 @@ struct BLEServiceCoreTests {
         #expect(ble.currentPeerSnapshots().isEmpty)
     }
 
+    @Test
+    func unsignedAndBadSignatureLeaveDoNotEvictOrRelayClaimedPeer() async throws {
+        let ble = makeService()
+        let alice = NoiseEncryptionService(keychain: MockKeychain())
+        let mallory = NoiseEncryptionService(keychain: MockKeychain())
+        let alicePeerID = PeerID(publicKey: alice.getStaticPublicKeyData())
+        let outbound = OutboundPacketTap()
+        ble._test_onOutboundPacket = outbound.record
+
+        let unsigned = makeLeavePacket(sender: alicePeerID, marker: "unsigned")
+        ble._test_handlePacket(
+            unsigned,
+            fromPeerID: alicePeerID,
+            signingPublicKey: alice.getSigningPublicKeyData()
+        )
+
+        let unsignedRelayed = await TestHelpers.waitUntil(
+            { outbound.count(ofType: .leave) > 0 },
+            timeout: TestConstants.shortTimeout
+        )
+        #expect(!unsignedRelayed)
+        #expect(ble.currentPeerSnapshots().contains { $0.peerID == alicePeerID })
+
+        let badSignature = try #require(
+            mallory.signPacket(makeLeavePacket(sender: alicePeerID, marker: "bad-signature"))
+        )
+        ble._test_handlePacket(
+            badSignature,
+            fromPeerID: alicePeerID,
+            signingPublicKey: alice.getSigningPublicKeyData()
+        )
+
+        let badSignatureRelayed = await TestHelpers.waitUntil(
+            { outbound.count(ofType: .leave) > 0 },
+            timeout: TestConstants.shortTimeout
+        )
+        #expect(!badSignatureRelayed)
+        #expect(ble.currentPeerSnapshots().contains { $0.peerID == alicePeerID })
+    }
+
+    @Test
+    func validSignedLeaveEvictsSessionAndRelays() async throws {
+        let ble = makeService()
+        let alice = NoiseEncryptionService(keychain: MockKeychain())
+        let alicePeerID = PeerID(publicKey: alice.getStaticPublicKeyData())
+
+        // Establish a real session so the leave regression also verifies that
+        // stale secure-delivery state is retired, not just the peer-list row.
+        let message1 = try ble._test_noiseInitiateHandshake(with: alicePeerID)
+        let message2 = try #require(
+            try alice.processHandshakeMessage(from: ble.myPeerID, message: message1)
+        )
+        let message3 = try #require(
+            try ble._test_noiseProcessHandshakeMessage(from: alicePeerID, message: message2)
+        )
+        _ = try alice.processHandshakeMessage(from: ble.myPeerID, message: message3)
+        #expect(ble.canDeliverSecurely(to: alicePeerID))
+        let centralUUID = "central-valid-leave"
+        ble._test_bindCentral(centralUUID, to: alicePeerID)
+        ble._test_markNoiseAuthenticatedCentral(centralUUID, to: alicePeerID)
+        #expect(ble._test_isNoiseAuthenticatedCentral(centralUUID, for: alicePeerID))
+
+        let outbound = OutboundPacketTap()
+        ble._test_onOutboundPacket = outbound.record
+        let signedLeave = try #require(
+            alice.signPacket(makeLeavePacket(sender: alicePeerID, marker: "valid"))
+        )
+        ble._test_handlePacket(
+            signedLeave,
+            fromPeerID: alicePeerID,
+            signingPublicKey: alice.getSigningPublicKeyData()
+        )
+
+        let evicted = await TestHelpers.waitUntil(
+            {
+                !ble.currentPeerSnapshots().contains { $0.peerID == alicePeerID }
+                    && !ble.canDeliverSecurely(to: alicePeerID)
+                    && !ble._test_isNoiseAuthenticatedCentral(centralUUID, for: alicePeerID)
+            },
+            timeout: TestConstants.longTimeout
+        )
+        #expect(evicted)
+        let relayed = await TestHelpers.waitUntil(
+            { outbound.count(ofType: .leave) == 1 },
+            timeout: TestConstants.longTimeout
+        )
+        #expect(relayed)
+    }
+
     @Test
     func ingressAllowsRelayedSenderOnBoundLink() async throws {
         let ble = makeService()
@@ -690,6 +779,18 @@ private func makePublicPacket(content: String, sender: PeerID, timestamp: UInt64
     )
 }
 
+private func makeLeavePacket(sender: PeerID, marker: String) -> BitchatPacket {
+    BitchatPacket(
+        type: MessageType.leave.rawValue,
+        senderID: Data(hexString: sender.id) ?? Data(),
+        recipientID: nil,
+        timestamp: UInt64(Date().timeIntervalSince1970 * 1000),
+        payload: Data(marker.utf8),
+        signature: nil,
+        ttl: TransportConfig.messageTTLDefault
+    )
+}
+
 private final class PublicCaptureDelegate: BitchatDelegate {
     private let lock = NSLock()
     private(set) var publicMessages: [BitchatMessage] = []

bitchatTests/ChatMediaTransferCoordinatorContextTests.swift

@@ -7,10 +7,9 @@
 // `ChatViewModel`, following the `ChatDeliveryCoordinatorContextTests` /
 // `ChatPrivateConversationCoordinatorContextTests` exemplars.
 //
-// Scope note: the async media-preparation pipelines (`ImageUtils`,
-// `ChatMediaPreparation`) run real file/codec work and remain covered by
-// `ChatMediaPreparationTests`; here we cover message enqueueing, transfer
-// bookkeeping, and the blocked-context guards.
+// Real file/codec work remains covered by `ChatMediaPreparationTests`. These
+// tests inject a paused voice-note preparer to exercise cancellation ownership
+// across the detached-preparation/MainActor boundary deterministically.
 //
 
 import Testing
@@ -86,11 +85,72 @@ private final class MockChatMediaTransferContext: ChatMediaTransferContext {
 
     // Mesh file transfer
     private(set) var privateFileSends: [(peerID: PeerID, transferId: String)] = []
+    private(set) var privateFileLegacyAllowances: [Bool] = []
     private(set) var broadcastFileSends: [String] = []
     private(set) var cancelledTransfers: [String] = []
+    var privateMediaPolicy: PrivateMediaSendPolicy = .encrypted
+    var resolvedPrivateMediaPolicy: PrivateMediaSendPolicy?
+    private(set) var legacyConsentRequests: [(
+        id: UUID,
+        peerID: PeerID,
+        transferId: String,
+        messageID: String
+    )] = []
+    private(set) var invalidatedLegacyConsents: [(transferId: String, messageID: String)] = []
+    private var pendingLegacyConsentIDs: [UUID] = []
+    private var legacyConsentCompletions: [UUID: @MainActor (Bool) -> Void] = [:]
 
-    func sendFilePrivate(_ packet: BitchatFilePacket, to peerID: PeerID, transferId: String) {
+    func privateMediaSendPolicy(to peerID: PeerID) -> PrivateMediaSendPolicy {
+        privateMediaPolicy
+    }
+
+    func resolvePrivateMediaSendPolicy(
+        to peerID: PeerID,
+        completion: @escaping @MainActor (PrivateMediaSendPolicy) -> Void
+    ) {
+        completion(resolvedPrivateMediaPolicy ?? privateMediaPolicy)
+    }
+
+    func requestLegacyPrivateMediaConsent(
+        for peerID: PeerID,
+        transferId: String,
+        messageID: String,
+        completion: @escaping @MainActor (Bool) -> Void
+    ) {
+        let id = UUID()
+        legacyConsentRequests.append((id, peerID, transferId, messageID))
+        pendingLegacyConsentIDs.append(id)
+        legacyConsentCompletions[id] = completion
+    }
+
+    func cancelLegacyPrivateMediaConsent(transferId: String, messageID: String) {
+        invalidatedLegacyConsents.append((transferId, messageID))
+        let matchingIDs = Set(legacyConsentRequests.compactMap { request in
+            request.transferId == transferId && request.messageID == messageID
+                ? request.id
+                : nil
+        })
+        pendingLegacyConsentIDs.removeAll { matchingIDs.contains($0) }
+    }
+
+    func resolveNextLegacyConsent(_ approved: Bool) {
+        guard !pendingLegacyConsentIDs.isEmpty else { return }
+        let id = pendingLegacyConsentIDs.removeFirst()
+        legacyConsentCompletions[id]?(approved)
+    }
+
+    func invokeLegacyConsentEvenIfInvalidated(id: UUID, approved: Bool) {
+        legacyConsentCompletions[id]?(approved)
+    }
+
+    func sendFilePrivate(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        allowLegacyFallback: Bool
+    ) {
         privateFileSends.append((peerID, transferId))
+        privateFileLegacyAllowances.append(allowLegacyFallback)
     }
 
     func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String) {
@@ -102,6 +162,56 @@ private final class MockChatMediaTransferContext: ChatMediaTransferContext {
     }
 }
 
+private final class PausedVoiceNotePreparer: @unchecked Sendable {
+    private let condition = NSCondition()
+    private var started = false
+    private var released = false
+    private var finished = false
+    private let packet: BitchatFilePacket
+
+    init() {
+        let content = Data("voice".utf8)
+        packet = BitchatFilePacket(
+            fileName: "paused.m4a",
+            fileSize: UInt64(content.count),
+            mimeType: "audio/mp4",
+            content: content
+        )
+    }
+
+    func prepare(_: URL) throws -> BitchatFilePacket {
+        condition.lock()
+        started = true
+        condition.broadcast()
+        while !released {
+            condition.wait()
+        }
+        finished = true
+        condition.broadcast()
+        condition.unlock()
+        return packet
+    }
+
+    var hasStarted: Bool {
+        condition.lock()
+        defer { condition.unlock() }
+        return started
+    }
+
+    var hasFinished: Bool {
+        condition.lock()
+        defer { condition.unlock() }
+        return finished
+    }
+
+    func release() {
+        condition.lock()
+        released = true
+        condition.broadcast()
+        condition.unlock()
+    }
+}
+
 // MARK: - Coordinator Tests Against Mock Context
 
 /// Exercises `ChatMediaTransferCoordinator` against
@@ -166,6 +276,14 @@ struct ChatMediaTransferCoordinatorContextTests {
         #expect(context.removedMessages.count == 1)
         #expect(context.removedMessages.first?.messageID == "m2")
         #expect(context.removedMessages.first?.cleanupFile == true)
+
+        // A pre-start rejection keeps the placeholder visible and failed,
+        // including queued post-handshake encryption failures.
+        coordinator.registerTransfer(transferId: "t3", messageID: "m3")
+        coordinator.handleTransferEvent(.rejected(id: "t3", reason: "encryption failed"))
+        #expect(context.deliveryStatusUpdates.last?.messageID == "m3")
+        #expect(context.deliveryStatusUpdates.last?.status == .failed(reason: "encryption failed"))
+        #expect(coordinator.messageIDToTransferId["m3"] == nil)
     }
 
     @Test @MainActor
@@ -188,6 +306,20 @@ struct ChatMediaTransferCoordinatorContextTests {
         #expect(coordinator.messageIDToTransferId.isEmpty)
     }
 
+    @Test @MainActor
+    func deleteMediaMessage_cancelsApprovedTransferBeforeRemovingMapping() {
+        let context = MockChatMediaTransferContext()
+        let coordinator = ChatMediaTransferCoordinator(context: context)
+        coordinator.registerTransfer(transferId: "approved-delete", messageID: "message-delete")
+
+        coordinator.deleteMediaMessage(messageID: "message-delete")
+
+        #expect(context.cancelledTransfers == ["approved-delete"])
+        #expect(coordinator.messageIDToTransferId["message-delete"] == nil)
+        #expect(context.removedMessages.map(\.messageID) == ["message-delete"])
+        #expect(context.removedMessages.first?.cleanupFile == true)
+    }
+
     @Test @MainActor
     func sendVoiceNote_blockedContextRemovesFileAndExplains() async throws {
         let context = MockChatMediaTransferContext()
@@ -206,4 +338,249 @@ struct ChatMediaTransferCoordinatorContextTests {
         #expect(context.appendedPublicMessages.isEmpty)
         #expect(coordinator.transferIdToMessageIDs.isEmpty)
     }
+
+    @Test @MainActor
+    func cancelVoiceNoteDuringDetachedPreparationCannotSendOrRestoreMapping() async throws {
+        let context = MockChatMediaTransferContext()
+        let peerID = PeerID(str: "5566778899aabbcc")
+        context.selectedPrivateChatPeer = peerID
+        let preparer = PausedVoiceNotePreparer()
+        let coordinator = ChatMediaTransferCoordinator(
+            context: context,
+            prepareVoiceNotePacket: { url in try preparer.prepare(url) }
+        )
+        let url = FileManager.default.temporaryDirectory
+            .appendingPathComponent("paused-private-\(UUID().uuidString).m4a")
+        try Data("voice".utf8).write(to: url)
+        defer {
+            preparer.release()
+            try? FileManager.default.removeItem(at: url)
+        }
+
+        coordinator.sendVoiceNote(at: url)
+        #expect(await TestHelpers.waitUntil({ preparer.hasStarted }, timeout: TestConstants.longTimeout))
+        let messageID = try #require(context.privateChats[peerID]?.first?.id)
+        let transferId = try #require(coordinator.messageIDToTransferId[messageID])
+
+        coordinator.cancelMediaSend(messageID: messageID)
+        preparer.release()
+        #expect(await TestHelpers.waitUntil({ preparer.hasFinished }, timeout: TestConstants.longTimeout))
+        for _ in 0..<10 { await Task.yield() }
+
+        #expect(context.cancelledTransfers == [transferId])
+        #expect(context.privateFileSends.isEmpty)
+        #expect(context.broadcastFileSends.isEmpty)
+        #expect(coordinator.messageIDToTransferId[messageID] == nil)
+        #expect(coordinator.transferIdToMessageIDs[transferId] == nil)
+        #expect(context.removedMessages.map(\.messageID) == [messageID])
+    }
+
+    @Test @MainActor
+    func deletePublicVoiceNoteDuringDetachedPreparationCannotBroadcastOrRestoreMapping() async throws {
+        let context = MockChatMediaTransferContext()
+        let preparer = PausedVoiceNotePreparer()
+        let coordinator = ChatMediaTransferCoordinator(
+            context: context,
+            prepareVoiceNotePacket: { url in try preparer.prepare(url) }
+        )
+        let url = FileManager.default.temporaryDirectory
+            .appendingPathComponent("paused-public-\(UUID().uuidString).m4a")
+        try Data("voice".utf8).write(to: url)
+        defer {
+            preparer.release()
+            try? FileManager.default.removeItem(at: url)
+        }
+
+        coordinator.sendVoiceNote(at: url)
+        #expect(await TestHelpers.waitUntil({ preparer.hasStarted }, timeout: TestConstants.longTimeout))
+        let messageID = try #require(context.appendedPublicMessages.first?.message.id)
+        let transferId = try #require(coordinator.messageIDToTransferId[messageID])
+
+        coordinator.deleteMediaMessage(messageID: messageID)
+        preparer.release()
+        #expect(await TestHelpers.waitUntil({ preparer.hasFinished }, timeout: TestConstants.longTimeout))
+        for _ in 0..<10 { await Task.yield() }
+
+        #expect(context.cancelledTransfers == [transferId])
+        #expect(context.broadcastFileSends.isEmpty)
+        #expect(context.privateFileSends.isEmpty)
+        #expect(coordinator.messageIDToTransferId[messageID] == nil)
+        #expect(coordinator.transferIdToMessageIDs[transferId] == nil)
+        #expect(context.removedMessages.map(\.messageID) == [messageID])
+    }
+
+    @Test @MainActor
+    func voicePreparationFailureMarksPlaceholderFailedAndClearsEarlyMapping() async throws {
+        let context = MockChatMediaTransferContext()
+        let peerID = PeerID(str: "66778899aabbccdd")
+        context.selectedPrivateChatPeer = peerID
+        let coordinator = ChatMediaTransferCoordinator(
+            context: context,
+            prepareVoiceNotePacket: { _ in
+                throw ChatMediaPreparationError.voiceNoteTooLarge(bytes: 999_999)
+            }
+        )
+        let url = FileManager.default.temporaryDirectory
+            .appendingPathComponent("failing-private-\(UUID().uuidString).m4a")
+        try Data("voice".utf8).write(to: url)
+        defer { try? FileManager.default.removeItem(at: url) }
+
+        coordinator.sendVoiceNote(at: url)
+        #expect(await TestHelpers.waitUntil(
+            {
+                context.deliveryStatusUpdates.contains { update in
+                    if case .failed = update.status { return true }
+                    return false
+                }
+            },
+            timeout: TestConstants.longTimeout
+        ))
+        let messageID = try #require(context.privateChats[peerID]?.first?.id)
+
+        #expect(coordinator.messageIDToTransferId[messageID] == nil)
+        #expect(coordinator.transferIdToMessageIDs.isEmpty)
+        #expect(context.privateFileSends.isEmpty)
+        #expect(context.broadcastFileSends.isEmpty)
+    }
+
+    @Test @MainActor
+    func legacyPrivateVoiceNoteWaitsForPerSendConsent() async throws {
+        let context = MockChatMediaTransferContext()
+        let coordinator = ChatMediaTransferCoordinator(context: context)
+        let peerID = PeerID(str: "1122334455667788")
+        context.selectedPrivateChatPeer = peerID
+        context.privateMediaPolicy = .legacyRequiresConsent
+        let url = FileManager.default.temporaryDirectory
+            .appendingPathComponent("legacy-consent-\(UUID().uuidString).m4a")
+        try (Data([0x00, 0x00, 0x00, 0x18]) + Data("ftypM4A voice".utf8)).write(to: url)
+        defer { try? FileManager.default.removeItem(at: url) }
+
+        coordinator.sendVoiceNote(at: url)
+
+        let prompted = await TestHelpers.waitUntil(
+            { context.legacyConsentRequests.count == 1 },
+            timeout: TestConstants.longTimeout
+        )
+        #expect(prompted)
+        #expect(context.legacyConsentRequests.map { $0.peerID } == [peerID])
+        #expect(context.privateFileSends.isEmpty)
+
+        context.resolveNextLegacyConsent(true)
+
+        #expect(context.privateFileSends.count == 1)
+        #expect(context.privateFileLegacyAllowances == [true])
+    }
+
+    @Test @MainActor
+    func capabilityProofTimeoutTransitionsToConsentWithoutAutomaticRawSend() async throws {
+        let context = MockChatMediaTransferContext()
+        let coordinator = ChatMediaTransferCoordinator(context: context)
+        let peerID = PeerID(str: "1020304050607080")
+        context.selectedPrivateChatPeer = peerID
+        context.privateMediaPolicy = .awaitingCapabilityProof
+        context.resolvedPrivateMediaPolicy = .legacyRequiresConsent
+        let url = FileManager.default.temporaryDirectory
+            .appendingPathComponent("proof-timeout-consent-\(UUID().uuidString).m4a")
+        try Data("voice".utf8).write(to: url)
+        defer { try? FileManager.default.removeItem(at: url) }
+
+        coordinator.sendVoiceNote(at: url)
+
+        let prompted = await TestHelpers.waitUntil(
+            { context.legacyConsentRequests.count == 1 },
+            timeout: TestConstants.longTimeout
+        )
+        #expect(prompted)
+        #expect(context.privateFileSends.isEmpty)
+        context.resolveNextLegacyConsent(false)
+        #expect(context.privateFileSends.isEmpty)
+    }
+
+    @Test @MainActor
+    func legacyConsentApprovalAfterCancelCannotSend() async throws {
+        let context = MockChatMediaTransferContext()
+        let coordinator = ChatMediaTransferCoordinator(context: context)
+        let peerID = PeerID(str: "2233445566778899")
+        context.selectedPrivateChatPeer = peerID
+        context.privateMediaPolicy = .legacyRequiresConsent
+        let url = FileManager.default.temporaryDirectory
+            .appendingPathComponent("legacy-cancel-\(UUID().uuidString).m4a")
+        try Data("voice".utf8).write(to: url)
+        defer { try? FileManager.default.removeItem(at: url) }
+
+        coordinator.sendVoiceNote(at: url)
+        let prompted = await TestHelpers.waitUntil(
+            { context.legacyConsentRequests.count == 1 },
+            timeout: TestConstants.longTimeout
+        )
+        #expect(prompted)
+        let request = try #require(context.legacyConsentRequests.first)
+
+        coordinator.cancelMediaSend(messageID: request.messageID)
+        #expect(context.invalidatedLegacyConsents.contains {
+            $0.transferId == request.transferId && $0.messageID == request.messageID
+        })
+
+        // Model a stale framework callback that escaped active invalidation.
+        // The coordinator's transfer/message binding check is the final gate.
+        context.invokeLegacyConsentEvenIfInvalidated(id: request.id, approved: true)
+        #expect(context.privateFileSends.isEmpty)
+        #expect(coordinator.messageIDToTransferId[request.messageID] == nil)
+    }
+
+    @Test @MainActor
+    func legacyConsentApprovalAfterDeleteCannotSend() async throws {
+        let context = MockChatMediaTransferContext()
+        let coordinator = ChatMediaTransferCoordinator(context: context)
+        let peerID = PeerID(str: "33445566778899aa")
+        context.selectedPrivateChatPeer = peerID
+        context.privateMediaPolicy = .legacyRequiresConsent
+        let url = FileManager.default.temporaryDirectory
+            .appendingPathComponent("legacy-delete-\(UUID().uuidString).m4a")
+        try Data("voice".utf8).write(to: url)
+        defer { try? FileManager.default.removeItem(at: url) }
+
+        coordinator.sendVoiceNote(at: url)
+        let prompted = await TestHelpers.waitUntil(
+            { context.legacyConsentRequests.count == 1 },
+            timeout: TestConstants.longTimeout
+        )
+        #expect(prompted)
+        let request = try #require(context.legacyConsentRequests.first)
+
+        coordinator.deleteMediaMessage(messageID: request.messageID)
+        context.invokeLegacyConsentEvenIfInvalidated(id: request.id, approved: true)
+
+        #expect(context.invalidatedLegacyConsents.contains {
+            $0.transferId == request.transferId && $0.messageID == request.messageID
+        })
+        #expect(context.privateFileSends.isEmpty)
+        #expect(coordinator.messageIDToTransferId[request.messageID] == nil)
+    }
+
+    @Test @MainActor
+    func pinnedPrivateMediaDowngradeNeverPromptsOrSends() async throws {
+        let context = MockChatMediaTransferContext()
+        let coordinator = ChatMediaTransferCoordinator(context: context)
+        let peerID = PeerID(str: "1122334455667788")
+        context.selectedPrivateChatPeer = peerID
+        context.privateMediaPolicy = .blockedDowngrade
+        let url = FileManager.default.temporaryDirectory
+            .appendingPathComponent("blocked-downgrade-\(UUID().uuidString).m4a")
+        try Data("voice".utf8).write(to: url)
+        defer { try? FileManager.default.removeItem(at: url) }
+
+        coordinator.sendVoiceNote(at: url)
+
+        let failed = await TestHelpers.waitUntil(
+            { context.deliveryStatusUpdates.contains { update in
+                if case .failed = update.status { return true }
+                return false
+            } },
+            timeout: TestConstants.longTimeout
+        )
+        #expect(failed)
+        #expect(context.legacyConsentRequests.isEmpty)
+        #expect(context.privateFileSends.isEmpty)
+    }
 }

bitchatTests/ChatViewModelExtensionsTests.swift

@@ -1048,6 +1048,89 @@ struct ChatViewModelMediaTransferTests {
         #expect(viewModel.transferIdToMessageIDs.count == 1)
     }
 
+    @Test @MainActor
+    func legacyPrivateMediaConsentRequestsArePerSendAndQueued() async throws {
+        let (viewModel, _) = makeTestableViewModel()
+        let firstPeer = PeerID(str: "1111111111111111")
+        let secondPeer = PeerID(str: "2222222222222222")
+        var decisions: [Bool] = []
+
+        viewModel.enqueueLegacyPrivateMediaConsent(
+            for: firstPeer,
+            transferId: "transfer-1",
+            messageID: "message-1"
+        ) { decisions.append($0) }
+        viewModel.enqueueLegacyPrivateMediaConsent(
+            for: secondPeer,
+            transferId: "transfer-2",
+            messageID: "message-2"
+        ) { decisions.append($0) }
+
+        #expect(viewModel.legacyPrivateMediaConsentRequest?.peerID == firstPeer)
+        let firstRequestID = try #require(viewModel.legacyPrivateMediaConsentRequest?.id)
+        viewModel.resolveLegacyPrivateMediaConsent(requestID: firstRequestID, approved: true)
+        let showedSecond = await TestHelpers.waitUntil(
+            { viewModel.legacyPrivateMediaConsentRequest?.peerID == secondPeer },
+            timeout: TestConstants.longTimeout
+        )
+        #expect(showedSecond)
+        let secondRequestID = try #require(viewModel.legacyPrivateMediaConsentRequest?.id)
+
+        // A button action and the dialog binding may both resolve the first
+        // ID. The stale second callback must not consume the queued request.
+        viewModel.resolveLegacyPrivateMediaConsent(requestID: firstRequestID, approved: false)
+        #expect(decisions == [true])
+        #expect(viewModel.legacyPrivateMediaConsentRequest?.id == secondRequestID)
+
+        viewModel.resolveLegacyPrivateMediaConsent(requestID: secondRequestID, approved: false)
+
+        #expect(decisions == [true, false])
+        #expect(viewModel.legacyPrivateMediaConsentRequest == nil)
+    }
+
+    @Test @MainActor
+    func invalidatingPresentedLegacyConsentAdvancesQueueAndStaleResolutionNoops() async throws {
+        let (viewModel, _) = makeTestableViewModel()
+        let firstPeer = PeerID(str: "3333333333333333")
+        let secondPeer = PeerID(str: "4444444444444444")
+        var decisions: [String] = []
+
+        viewModel.enqueueLegacyPrivateMediaConsent(
+            for: firstPeer,
+            transferId: "transfer-cancelled",
+            messageID: "message-cancelled"
+        ) { decisions.append("first:\($0)") }
+        viewModel.enqueueLegacyPrivateMediaConsent(
+            for: secondPeer,
+            transferId: "transfer-kept",
+            messageID: "message-kept"
+        ) { decisions.append("second:\($0)") }
+
+        let cancelledRequestID = try #require(viewModel.legacyPrivateMediaConsentRequest?.id)
+        viewModel.invalidateLegacyPrivateMediaConsent(
+            transferId: "transfer-cancelled",
+            messageID: "message-cancelled"
+        )
+        let advanced = await TestHelpers.waitUntil(
+            { viewModel.legacyPrivateMediaConsentRequest?.peerID == secondPeer },
+            timeout: TestConstants.longTimeout
+        )
+        #expect(advanced)
+        #expect(decisions.isEmpty, "Invalidation drops the request rather than resolving its send")
+
+        viewModel.resolveLegacyPrivateMediaConsent(
+            requestID: cancelledRequestID,
+            approved: true
+        )
+        #expect(viewModel.legacyPrivateMediaConsentRequest?.peerID == secondPeer)
+        #expect(decisions.isEmpty)
+
+        let keptRequestID = try #require(viewModel.legacyPrivateMediaConsentRequest?.id)
+        viewModel.resolveLegacyPrivateMediaConsent(requestID: keptRequestID, approved: true)
+        #expect(decisions == ["second:true"])
+        #expect(viewModel.legacyPrivateMediaConsentRequest == nil)
+    }
+
     @Test @MainActor
     func sendVoiceNote_oversizedFileFailsAndDeletesTempFile() async throws {
         let (viewModel, transport) = makeTestableViewModel()

bitchatTests/Mocks/MockIdentityManager.swift

@@ -14,6 +14,8 @@ final class MockIdentityManager: SecureIdentityStateManagerProtocol {
     private var blockedFingerprints: Set<String> = []
     private var blockedNostrPubkeys: Set<String> = []
     private var socialIdentities: [String: SocialIdentity] = [:]
+    private var privateMediaCapableFingerprints: Set<String> = []
+    private var authenticatedSigningKeys: [String: Data] = [:]
 
     init(_: KeychainManagerProtocol) {}
     
@@ -87,7 +89,10 @@ final class MockIdentityManager: SecureIdentityStateManagerProtocol {
     
     func registerEphemeralSession(peerID: PeerID, handshakeState: HandshakeState) {}
 
-    func clearAllIdentityData() {}
+    func clearAllIdentityData() {
+        privateMediaCapableFingerprints.removeAll()
+        authenticatedSigningKeys.removeAll()
+    }
     
     func removeEphemeralSession(peerID: PeerID) {}
     
@@ -101,6 +106,22 @@ final class MockIdentityManager: SecureIdentityStateManagerProtocol {
         Set()
     }
 
+    func markPrivateMediaCapable(fingerprint: String) {
+        privateMediaCapableFingerprints.insert(fingerprint)
+    }
+
+    func hasObservedPrivateMediaCapability(fingerprint: String) -> Bool {
+        privateMediaCapableFingerprints.contains(fingerprint)
+    }
+
+    func bindAuthenticatedSigningPublicKey(_ signingPublicKey: Data, fingerprint: String) {
+        authenticatedSigningKeys[fingerprint] = signingPublicKey
+    }
+
+    func authenticatedSigningPublicKey(forFingerprint fingerprint: String) -> Data? {
+        authenticatedSigningKeys[fingerprint]
+    }
+
     // MARK: Vouching (transitive verification)
 
     private var vouchesByVouchee: [String: [VouchRecord]] = [:]

bitchatTests/Mocks/MockTransport.swift

@@ -36,6 +36,7 @@ final class MockTransport: Transport {
     private(set) var sentFavoriteNotifications: [(peerID: PeerID, isFavorite: Bool)] = []
     private(set) var sentBroadcastFiles: [(packet: BitchatFilePacket, transferID: String)] = []
     private(set) var sentPrivateFiles: [(packet: BitchatFilePacket, peerID: PeerID, transferID: String)] = []
+    private(set) var sentPrivateFileLegacyAllowances: [Bool] = []
     private(set) var cancelledTransfers: [String] = []
     private(set) var sentVerifyChallenges: [(peerID: PeerID, noiseKeyHex: String, nonceA: Data)] = []
     private(set) var sentVerifyResponses: [(peerID: PeerID, noiseKeyHex: String, nonceA: Data)] = []
@@ -58,6 +59,7 @@ final class MockTransport: Transport {
     var peerNicknames: [PeerID: String] = [:]
     var peerFingerprints: [PeerID: String] = [:]
     var peerNoiseStates: [PeerID: LazyHandshakeState] = [:]
+    var privateMediaPolicies: [PeerID: PrivateMediaSendPolicy] = [:]
     private let mockKeychain = MockKeychain()
 
     // MARK: - Transport Protocol Implementation
@@ -186,6 +188,29 @@ final class MockTransport: Transport {
 
     func sendFilePrivate(_ packet: BitchatFilePacket, to peerID: PeerID, transferId: String) {
         sentPrivateFiles.append((packet, peerID, transferId))
+        sentPrivateFileLegacyAllowances.append(false)
+    }
+
+    func sendFilePrivate(
+        _ packet: BitchatFilePacket,
+        to peerID: PeerID,
+        transferId: String,
+        allowLegacyFallback: Bool
+    ) {
+        sentPrivateFiles.append((packet, peerID, transferId))
+        sentPrivateFileLegacyAllowances.append(allowLegacyFallback)
+    }
+
+    func privateMediaSendPolicy(to peerID: PeerID) -> PrivateMediaSendPolicy {
+        privateMediaPolicies[peerID] ?? .encrypted
+    }
+
+    func resolvePrivateMediaSendPolicy(
+        to peerID: PeerID,
+        completion: @escaping @MainActor (PrivateMediaSendPolicy) -> Void
+    ) {
+        let policy = privateMediaPolicies[peerID] ?? .encrypted
+        Task { @MainActor in completion(policy) }
     }
 
     func cancelTransfer(_ transferId: String) {

bitchatTests/Noise/NoiseCoverageTests.swift

@@ -12,8 +12,15 @@ struct NoiseCoverageTests {
     private let bobStaticKey = Curve25519.KeyAgreement.PrivateKey()
     private let charlieStaticKey = Curve25519.KeyAgreement.PrivateKey()
 
-    private let alicePeerID = PeerID(str: "0011223344556677")
-    private let bobPeerID = PeerID(str: "8899aabbccddeeff")
+    // Manager test dictionaries are keyed by the remote peer. Keep the
+    // historical names, but derive each wire ID from the static key that the
+    // corresponding manager authenticates during the handshake.
+    private var alicePeerID: PeerID {
+        PeerID(publicKey: bobStaticKey.publicKey.rawRepresentation)
+    }
+    private var bobPeerID: PeerID {
+        PeerID(publicKey: aliceStaticKey.publicKey.rawRepresentation)
+    }
     private let charliePeerID = PeerID(str: "fedcba9876543210")
 
     @Test("Protocol metadata and handshake patterns expose expected values")
@@ -535,8 +542,12 @@ struct NoiseCoverageTests {
         let aliceManager = NoiseSessionManager(localStaticKey: aliceStaticKey, keychain: keychain)
         let bobManager = NoiseSessionManager(localStaticKey: bobStaticKey, keychain: keychain)
 
-        aliceManager.onSessionEstablished = establishedRecorder.recordEstablished(peerID:remoteKey:)
-        bobManager.onSessionEstablished = establishedRecorder.recordEstablished(peerID:remoteKey:)
+        aliceManager.onSessionEstablished = establishedRecorder.recordEstablished(
+            peerID:remoteKey:sessionGeneration:
+        )
+        bobManager.onSessionEstablished = establishedRecorder.recordEstablished(
+            peerID:remoteKey:sessionGeneration:
+        )
 
         try establishManagerSessions(aliceManager: aliceManager, bobManager: bobManager)
 
@@ -643,13 +654,121 @@ struct NoiseCoverageTests {
             try aliceManager.initiateHandshake(with: alicePeerID)
         }
 
-        try aliceManager.initiateRekey(for: alicePeerID)
+        let rekeyHandshake = try aliceManager.initiateRekey(for: alicePeerID)
+        #expect(!rekeyHandshake.isEmpty)
         let rekeyedSession = try #require(aliceManager.getSession(for: alicePeerID))
 
         #expect(rekeyedSession !== establishedSession)
         #expect(rekeyedSession.getState() == .handshaking)
     }
 
+    @Test("A stale decrypt generation cannot commit across session promotion")
+    func staleDecryptGenerationCannotCommitAcrossPromotion() throws {
+        let aliceManager = NoiseSessionManager(
+            localStaticKey: aliceStaticKey,
+            keychain: keychain,
+            sessionFactory: { peerID, role in
+                BlockingDecryptNoiseSession(
+                    peerID: peerID,
+                    role: role,
+                    keychain: self.keychain,
+                    localStaticKey: self.aliceStaticKey
+                )
+            }
+        )
+        let bobManager = NoiseSessionManager(localStaticKey: bobStaticKey, keychain: keychain)
+        try establishManagerSessions(aliceManager: aliceManager, bobManager: bobManager)
+
+        let oldSession = try #require(
+            aliceManager.getSession(for: alicePeerID) as? BlockingDecryptNoiseSession
+        )
+        let oldGeneration = try #require(aliceManager.sessionGeneration(for: alicePeerID))
+
+        // Prepare a fully authenticated responder candidate without promoting
+        // it yet. Its final XX message is the exact operation that replaces
+        // the old `sessions[peerID]` entry.
+        let replacementInitiator = NoiseSession(
+            peerID: bobPeerID,
+            role: .initiator,
+            keychain: keychain,
+            localStaticKey: bobStaticKey
+        )
+        let message1 = try replacementInitiator.startHandshake()
+        let message2 = try #require(
+            try aliceManager.handleIncomingHandshake(from: alicePeerID, message: message1)
+        )
+        let message3 = try #require(try replacementInitiator.processHandshakeMessage(message2))
+
+        let ciphertext = try bobManager.encrypt(Data("old session".utf8), for: bobPeerID)
+        oldSession.pauseNextDecrypt()
+
+        let decryptResult = ConcurrentTestResult<(plaintext: Data, sessionGeneration: UUID)>()
+        var promotionResultForCleanup: ConcurrentTestResult<Data?>?
+        defer {
+            // A failed startup requirement must not strand a late thread in
+            // the blocking test double after the test has returned.
+            oldSession.resumeDecrypt()
+            _ = decryptResult.wait(timeout: 5)
+            if let promotionResultForCleanup {
+                _ = promotionResultForCleanup.wait(timeout: 5)
+            }
+        }
+
+        let decryptThread = Thread {
+            decryptResult.capture {
+                try aliceManager.decryptWithSessionGeneration(ciphertext, from: self.alicePeerID)
+            }
+        }
+        decryptThread.name = "NoiseCoverageTests.staleDecrypt.decrypt"
+        decryptThread.qualityOfService = .userInitiated
+        decryptThread.start()
+        try #require(oldSession.waitForDecryptStart(timeout: 5))
+
+        let promotionStarted = DispatchSemaphore(value: 0)
+        let promotionResult = ConcurrentTestResult<Data?>()
+        promotionResultForCleanup = promotionResult
+        let promotionThread = Thread {
+            promotionStarted.signal()
+            promotionResult.capture {
+                try aliceManager.handleIncomingHandshake(from: self.alicePeerID, message: message3)
+            }
+        }
+        promotionThread.name = "NoiseCoverageTests.staleDecrypt.promote"
+        promotionThread.qualityOfService = .userInitiated
+        promotionThread.start()
+        try #require(promotionStarted.wait(timeout: .now() + 5) == .success)
+        #expect(
+            promotionResult.wait(timeout: 0.05) == nil,
+            "Promotion must wait for the exact decrypting-session lease"
+        )
+
+        oldSession.resumeDecrypt()
+        let decrypted = try #require(decryptResult.wait(timeout: 5)).get()
+        _ = try #require(promotionResult.wait(timeout: 5)).get()
+
+        #expect(decrypted.plaintext == Data("old session".utf8))
+        #expect(decrypted.sessionGeneration == oldGeneration)
+        #expect(aliceManager.sessionGeneration(for: alicePeerID) != oldGeneration)
+        #expect(throws: NoiseEncryptionError.sessionNotEstablished) {
+            try aliceManager.encrypt(
+                Data("stale send".utf8),
+                for: alicePeerID,
+                expectedSessionGeneration: oldGeneration
+            )
+        }
+
+        var staleCommitRan = false
+        let staleCommit = aliceManager.withCurrentSessionGeneration(
+            for: alicePeerID,
+            expected: decrypted.sessionGeneration
+        ) {
+            staleCommitRan = true
+            return true
+        }
+        #expect(staleCommit == nil)
+        #expect(!staleCommitRan)
+    }
+
     @Test("Secure noise sessions enforce limits and renegotiation thresholds")
     func secureNoiseSessionsEnforceLimitsAndThresholds() throws {
         let initiator = SecureNoiseSession(
@@ -844,7 +963,11 @@ private final class SessionCallbackRecorder: @unchecked Sendable {
         return establishedEntries.map(\.0)
     }
 
-    func recordEstablished(peerID: PeerID, remoteKey: Curve25519.KeyAgreement.PublicKey) {
+    func recordEstablished(
+        peerID: PeerID,
+        remoteKey: Curve25519.KeyAgreement.PublicKey,
+        sessionGeneration _: UUID
+    ) {
         lock.lock()
         establishedEntries.append((peerID, remoteKey.rawRepresentation))
         lock.unlock()
@@ -866,3 +989,62 @@ private final class FailingNoiseSession: NoiseSession {
         throw Error.synthetic
     }
 }
+
+private final class BlockingDecryptNoiseSession: NoiseSession, @unchecked Sendable {
+    private let controlLock = NSLock()
+    private var shouldPauseNextDecrypt = false
+    private let decryptStarted = DispatchSemaphore(value: 0)
+    private let resumeDecryptSemaphore = DispatchSemaphore(value: 0)
+
+    func pauseNextDecrypt() {
+        controlLock.lock()
+        shouldPauseNextDecrypt = true
+        controlLock.unlock()
+    }
+
+    func waitForDecryptStart(timeout: TimeInterval) -> Bool {
+        decryptStarted.wait(timeout: .now() + timeout) == .success
+    }
+
+    func resumeDecrypt() {
+        resumeDecryptSemaphore.signal()
+    }
+
+    override func decrypt(_ ciphertext: Data) throws -> Data {
+        controlLock.lock()
+        let shouldPause = shouldPauseNextDecrypt
+        shouldPauseNextDecrypt = false
+        controlLock.unlock()
+
+        if shouldPause {
+            decryptStarted.signal()
+            resumeDecryptSemaphore.wait()
+        }
+        return try super.decrypt(ciphertext)
+    }
+}
+
+private final class ConcurrentTestResult<Value>: @unchecked Sendable {
+    private let lock = NSLock()
+    private let completed = DispatchGroup()
+    private var storedResult: Result<Value, Error>?
+
+    init() {
+        completed.enter()
+    }
+
+    func capture(_ operation: () throws -> Value) {
+        let result = Result(catching: operation)
+        lock.lock()
+        storedResult = result
+        lock.unlock()
+        completed.leave()
+    }
+
+    func wait(timeout: TimeInterval) -> Result<Value, Error>? {
+        guard completed.wait(timeout: .now() + timeout) == .success else { return nil }
+        lock.lock()
+        defer { lock.unlock() }
+        return storedResult
+    }
+}

bitchatTests/Protocols/PacketsTests.swift

@@ -145,6 +145,39 @@ struct PacketsTests {
         #expect(decoded.capabilities?.rawValue == 0x0180)
     }
 
+    @Test
+    func authenticatedPeerStateUsesVersionedCanonicalTLVs() throws {
+        let signingKey = Data(repeating: 0xA5, count: 32)
+        let packet = AuthenticatedPeerStatePacket(
+            capabilities: [.privateMedia, .vouch],
+            signingPublicKey: signingKey
+        )
+
+        var encoded = try #require(packet.encode())
+        #expect(encoded.prefix(5) == Data([0x01, 0x01, 0x02, 0x20, 0x01]))
+        // Unknown TLVs are forward-compatible and do not alter v1 state.
+        encoded.append(makeTLV(type: 0x7F, value: Data([0xCA, 0xFE])))
+
+        #expect(AuthenticatedPeerStatePacket.decode(from: encoded) == packet)
+    }
+
+    @Test
+    func authenticatedPeerStateRejectsMalformedAmbiguousOrUnknownVersion() {
+        let key = Data(repeating: 0x44, count: 32)
+        let capabilities = makeTLV(type: 0x01, value: Data([0x00, 0x01]))
+        let signing = makeTLV(type: 0x02, value: key)
+
+        #expect(AuthenticatedPeerStatePacket.decode(from: Data([0x02]) + capabilities + signing) == nil)
+        #expect(AuthenticatedPeerStatePacket.decode(from: Data([0x01]) + signing) == nil)
+        #expect(AuthenticatedPeerStatePacket.decode(from: Data([0x01]) + capabilities + capabilities + signing) == nil)
+        #expect(AuthenticatedPeerStatePacket.decode(from: Data([0x01, 0x01, 0x00]) + signing) == nil)
+        // 0x0001 is non-minimal little endian; the canonical form is [0x01].
+        #expect(AuthenticatedPeerStatePacket.decode(from: Data([0x01]) + makeTLV(type: 0x01, value: Data([0x01, 0x00])) + signing) == nil)
+        #expect(AuthenticatedPeerStatePacket.decode(from: Data([0x01]) + capabilities + makeTLV(type: 0x02, value: Data(key.dropLast()))) == nil)
+        #expect(AuthenticatedPeerStatePacket.decode(from: Data([0x01]) + capabilities + Data(signing.dropLast())) == nil)
+        #expect(AuthenticatedPeerStatePacket.decode(from: Data([0x01]) + makeTLV(type: 0x01, value: Data(repeating: 0x01, count: 9)) + signing) == nil)
+    }
+
     @Test
     func privateMessagePacketRejectsUnknownTypeAndTruncation() {
         let unknownTLV = Data([0x7F, 0x01, 0x41])

bitchatTests/Services/BLEAnnounceHandlerTests.swift

@@ -6,6 +6,7 @@ import Testing
 struct BLEAnnounceHandlerTests {
     private final class Recorder {
         var existingNoisePublicKey: Data?
+        var authenticatedSigningPublicKey: Data?
         var signatureValid = true
         var linkState: (hasPeripheral: Bool, hasCentral: Bool) = (false, false)
         var linkBoundToOtherPeer = false
@@ -37,6 +38,7 @@ struct BLEAnnounceHandlerTests {
             messageTTL: TransportConfig.messageTTLDefault,
             now: { now },
             existingNoisePublicKey: { _ in recorder.existingNoisePublicKey },
+            authenticatedSigningPublicKey: { _ in recorder.authenticatedSigningPublicKey },
             verifySignature: { packet, signingPublicKey in
                 recorder.verifySignatureCalls.append((packet, signingPublicKey))
                 return recorder.signatureValid

bitchatTests/Services/BLEAnnounceHandlingPolicyTests.swift

@@ -169,6 +169,23 @@ struct BLEAnnounceHandlingPolicyTests {
         #expect(decision.isVerified)
     }
 
+    @Test
+    func trustPolicyRejectsSigningKeyReplacementAfterNoiseBinding() {
+        let noiseKey = Data(repeating: 0xCC, count: 32)
+        let boundSigningKey = Data(repeating: 0x11, count: 32)
+
+        let decision = BLEAnnounceTrustPolicy.evaluate(
+            hasSignature: true,
+            signatureValid: true,
+            existingNoisePublicKey: noiseKey,
+            announcedNoisePublicKey: noiseKey,
+            authenticatedSigningPublicKey: boundSigningKey,
+            announcedSigningPublicKey: Data(repeating: 0x22, count: 32)
+        )
+
+        #expect(decision == .reject(.authenticatedSigningKeyMismatch))
+    }
+
     @Test
     func responsePolicyConnectsOnlyForDirectNewOrReconnectedPeers() {
         let directNew = BLEAnnounceResponsePolicy.plan(

bitchatTests/Services/BLEFileTransferHandlerTests.swift

@@ -33,6 +33,7 @@ struct BLEFileTransferHandlerTests {
                 recorder.signatureVerifyCount += 1
                 return recorder.signatureVerifies
             },
+            localSigningPublicKey: { [sampleSigningKey] in sampleSigningKey },
             signedSenderDisplayName: { _, peerID in
                 recorder.signedNameQueries.append(peerID)
                 return recorder.signedName
@@ -92,12 +93,11 @@ struct BLEFileTransferHandlerTests {
     @Test
     func selfEchoIsDropped() throws {
         let recorder = Recorder()
+        recorder.signatureVerifies = true
         let handler = makeHandler(recorder: recorder)
         let packet = try makeFileTransferPacket(sender: localPeerID, mimeType: "application/pdf", content: Data("%PDF-1.7".utf8), ttl: 3)
 
-        // The relay pipeline already suppresses self-originated packets, so the
-        // handler reports "relayable" rather than treating the echo as forged.
-        #expect(handler.handle(packet, from: localPeerID))
+        #expect(!handler.handle(packet, from: localPeerID))
 
         expectNoSideEffects(recorder)
     }
@@ -120,7 +120,12 @@ struct BLEFileTransferHandlerTests {
         let recorder = Recorder()
         recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Bob", isVerified: false, isConnected: true)]
         let handler = makeHandler(recorder: recorder)
-        let packet = try makeFileTransferPacket(sender: remotePeerID, mimeType: "application/pdf", content: Data("%PDF-1.7".utf8))
+        let packet = try makeFileTransferPacket(
+            sender: remotePeerID,
+            mimeType: "application/pdf",
+            content: Data("%PDF-1.7".utf8),
+            hasSignature: false
+        )
 
         // Failed sender authentication must also stop the packet from being
         // relayed to downstream nodes.
@@ -129,7 +134,7 @@ struct BLEFileTransferHandlerTests {
         // Broadcast files carry an attacker-controllable senderID, so — like
         // public messages — a connected-but-unverified peer must present a valid
         // packet signature. No signing key + no signed identity means dropped.
-        #expect(recorder.signedNameQueries == [remotePeerID])
+        #expect(recorder.signedNameQueries.isEmpty)
         #expect(recorder.trackedPackets.isEmpty)
         #expect(recorder.deliveredMessages.isEmpty)
     }
@@ -153,12 +158,11 @@ struct BLEFileTransferHandlerTests {
     }
 
     @Test
-    func selfBroadcastReplayIsDeliveredWithoutSignatureCheck() throws {
-        // Our own broadcast file replayed via gossip sync arrives with ttl==0
-        // (so it is not treated as a self-echo) and cannot be verified against
-        // the peer registry — it must still be accepted, matching
-        // BLEPublicMessageHandler's self exemption.
+    func signedSelfBroadcastReplayIsDelivered() throws {
+        // Our own broadcast file replayed via gossip sync arrives with ttl==0;
+        // it is verified against our local signing key before delivery.
         let recorder = Recorder()
+        recorder.signatureVerifies = true
         let handler = makeHandler(recorder: recorder)
         let packet = try makeFileTransferPacket(
             sender: localPeerID,
@@ -169,7 +173,7 @@ struct BLEFileTransferHandlerTests {
 
         #expect(handler.handle(packet, from: localPeerID))
 
-        #expect(recorder.signatureVerifyCount == 0)
+        #expect(recorder.signatureVerifyCount == 1)
         #expect(recorder.signedNameQueries.isEmpty)
         #expect(recorder.deliveredMessages.count == 1)
         #expect(recorder.deliveredMessages.first?.sender == "Me")
@@ -205,7 +209,8 @@ struct BLEFileTransferHandlerTests {
             sender: remotePeerID,
             mimeType: "audio/mp4",
             content: m4a,
-            fileName: "voice_1122334455667788"
+            fileName: "voice_1122334455667788",
+            hasSignature: false
         )
 
         // The spoofed note must be dropped locally AND not relayed onward.
@@ -215,7 +220,7 @@ struct BLEFileTransferHandlerTests {
     }
 
     @Test
-    func privateFileFromConnectedUnverifiedPeerIsAccepted() throws {
+    func rawDirectedFileWithoutVerifiableSignatureIsDroppedWithoutWriteOrRelay() throws {
         let recorder = Recorder()
         recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Bob", isVerified: false, isConnected: true)]
         let handler = makeHandler(recorder: recorder)
@@ -223,23 +228,25 @@ struct BLEFileTransferHandlerTests {
             sender: remotePeerID,
             mimeType: "application/pdf",
             content: Data("%PDF-1.7".utf8),
-            recipientID: Data(hexString: localPeerID.id)
+            recipientID: Data(hexString: localPeerID.id),
+            hasSignature: false
         )
 
-        #expect(handler.handle(packet, from: remotePeerID))
+        #expect(!handler.handle(packet, from: remotePeerID))
 
-        // Directed transfers keep the lenient connected-peer path (no broadcast
-        // exposure); no signature check is required.
         #expect(recorder.signatureVerifyCount == 0)
         #expect(recorder.signedNameQueries.isEmpty)
-        #expect(recorder.deliveredMessages.count == 1)
-        #expect(recorder.deliveredMessages.first?.isPrivate == true)
+        #expect(recorder.trackedPackets.isEmpty)
+        #expect(recorder.quotaReservations.isEmpty)
+        #expect(recorder.saveCalls.isEmpty)
+        #expect(recorder.deliveredMessages.isEmpty)
     }
 
     @Test
     func fileDirectedToAnotherPeerIsIgnored() throws {
         let recorder = Recorder()
-        recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Alice", isVerified: true)]
+        recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Alice", isVerified: true, signingPublicKey: sampleSigningKey)]
+        recorder.signatureVerifies = true
         let handler = makeHandler(recorder: recorder)
         let packet = try makeFileTransferPacket(
             sender: remotePeerID,
@@ -260,7 +267,8 @@ struct BLEFileTransferHandlerTests {
     @Test
     func privateFileUpdatesLastSeenAndDeliversPrivateMessage() throws {
         let recorder = Recorder()
-        recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Alice", isVerified: true)]
+        recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Alice", isVerified: true, signingPublicKey: sampleSigningKey)]
+        recorder.signatureVerifies = true
         let handler = makeHandler(recorder: recorder)
         let packet = try makeFileTransferPacket(
             sender: remotePeerID,
@@ -282,6 +290,56 @@ struct BLEFileTransferHandlerTests {
         #expect(recorder.deliveredMessages.first?.deliveryStatus == .delivered(to: "Me", at: Date(timeIntervalSince1970: 900)))
     }
 
+    @Test
+    func decryptedPrivateFileUsesValidationQuotaAndPrivateDeliveryWithoutRawSignature() throws {
+        let recorder = Recorder()
+        recorder.peers = [remotePeerID: makePeerInfo(remotePeerID, nickname: "Alice", isVerified: true)]
+        let handler = makeHandler(recorder: recorder)
+        let content = Data([0xFF, 0xD8, 0xFF]) + Data(repeating: 0x41, count: 128)
+        let file = BitchatFilePacket(
+            fileName: "secret.jpg",
+            fileSize: UInt64(content.count),
+            mimeType: "image/jpeg",
+            content: content
+        )
+        let payload = try #require(file.encode())
+        let timestamp = Date(timeIntervalSince1970: 1_234)
+
+        #expect(handler.handlePrivatePayload(payload, from: remotePeerID, timestamp: timestamp))
+
+        #expect(recorder.signatureVerifyCount == 0)
+        #expect(recorder.signedNameQueries.isEmpty)
+        #expect(recorder.trackedPackets.isEmpty)
+        #expect(recorder.quotaReservations == [content.count])
+        #expect(recorder.saveCalls.first?.data == content)
+        #expect(recorder.lastSeenUpdates == [remotePeerID])
+        #expect(recorder.deliveredMessages.count == 1)
+        #expect(recorder.deliveredMessages.first?.isPrivate == true)
+        #expect(recorder.deliveredMessages.first?.timestamp == timestamp)
+    }
+
+    @Test
+    func decryptedPrivateFileOverPayloadCapIsRejectedBeforeQuotaOrDiskWrite() {
+        let recorder = Recorder()
+        let handler = makeHandler(recorder: recorder)
+        let oversizedCount = FileTransferLimits.maxPayloadBytes + 1
+        var length = UInt32(oversizedCount).bigEndian
+        var payload = Data([0x04]) // BitchatFilePacket CONTENT TLV
+        withUnsafeBytes(of: &length) { payload.append(contentsOf: $0) }
+        payload.append(Data(repeating: 0x41, count: oversizedCount))
+
+        #expect(!handler.handlePrivatePayload(
+            payload,
+            from: remotePeerID,
+            timestamp: Date(timeIntervalSince1970: 1_234)
+        ))
+
+        #expect(recorder.quotaReservations.isEmpty)
+        #expect(recorder.saveCalls.isEmpty)
+        #expect(recorder.lastSeenUpdates.isEmpty)
+        #expect(recorder.deliveredMessages.isEmpty)
+    }
+
     @Test
     func malformedPayloadIsTrackedForSyncButDropped() {
         let recorder = Recorder()
@@ -294,7 +352,7 @@ struct BLEFileTransferHandlerTests {
             recipientID: nil,
             timestamp: 900_000,
             payload: Data([0x01, 0x02, 0x03]),
-            signature: nil,
+            signature: Data(repeating: 0x5A, count: 64),
             ttl: TransportConfig.messageTTLDefault
         )
 
@@ -403,7 +461,8 @@ struct BLEFileTransferHandlerTests {
         content: Data,
         ttl: UInt8 = TransportConfig.messageTTLDefault,
         recipientID: Data? = nil,
-        fileName: String = "sample"
+        fileName: String = "sample",
+        hasSignature: Bool = true
     ) throws -> BitchatPacket {
         let filePacket = BitchatFilePacket(
             fileName: fileName,
@@ -418,7 +477,7 @@ struct BLEFileTransferHandlerTests {
             recipientID: recipientID,
             timestamp: 900_000,
             payload: payload,
-            signature: nil,
+            signature: hasSignature ? Data(repeating: 0x5A, count: 64) : nil,
             ttl: ttl
         )
     }

bitchatTests/Services/BLEFragmentAssemblyBufferTests.swift

@@ -117,6 +117,35 @@ struct BLEFragmentAssemblyBufferTests {
         }
     }
 
+    @Test
+    func encryptedPrivateFileAssemblyGetsFramedFileHeadroom() throws {
+        var buffer = BLEFragmentAssemblyBuffer()
+        let fragmentID = Data(repeating: 0x15, count: 8)
+        let first = try #require(BLEFragmentHeader(packet: makeFragmentPacket(
+            fragmentID: fragmentID,
+            index: 0,
+            total: 2,
+            originalType: MessageType.noiseEncrypted.rawValue,
+            fragmentData: Data(repeating: 0x01, count: FileTransferLimits.maxPayloadBytes)
+        )))
+        let second = try #require(BLEFragmentHeader(packet: makeFragmentPacket(
+            fragmentID: fragmentID,
+            index: 1,
+            total: 2,
+            originalType: MessageType.noiseEncrypted.rawValue,
+            fragmentData: Data([0x02])
+        )))
+
+        _ = buffer.append(first, maxInFlightAssemblies: 8)
+        let result = buffer.append(second, maxInFlightAssemblies: 8)
+
+        if case let .complete(_, data, _) = result {
+            #expect(data.count == FileTransferLimits.maxPayloadBytes + 1)
+        } else {
+            Issue.record("Expected encrypted private-file assembly to use framed-file limit")
+        }
+    }
+
     @Test
     func removeExpiredDropsOldAssemblies() throws {
         var buffer = BLEFragmentAssemblyBuffer()

bitchatTests/Services/BLENoisePacketHandlerTests.swift

@@ -9,6 +9,7 @@ struct BLENoisePacketHandlerTests {
     private final class Recorder {
         var handshakeResult: Result<Data?, Error> = .success(nil)
         var hasSession = false
+        let sessionGeneration = UUID()
         var decryptResult: Result<Data, Error> = .success(Data())
 
         var processedHandshakes: [(peerID: PeerID, message: Data)] = []
@@ -18,6 +19,7 @@ struct BLENoisePacketHandlerTests {
         var lastSeenUpdates: [PeerID] = []
         var decryptCalls: [(payload: Data, peerID: PeerID)] = []
         var clearedSessions: [PeerID] = []
+        var authenticatedPeerStates: [(peerID: PeerID, payload: Data, generation: UUID)] = []
         var deliveries: [(peerID: PeerID, type: NoisePayloadType, payload: Data, timestamp: Date)] = []
         /// Ordered side-effect log to assert recovery sequencing.
         var events: [String] = []
@@ -56,12 +58,18 @@ struct BLENoisePacketHandlerTests {
             },
             decrypt: { payload, peerID in
                 recorder.decryptCalls.append((payload, peerID))
-                return try recorder.decryptResult.get()
+                return BLENoiseDecryptionResult(
+                    plaintext: try recorder.decryptResult.get(),
+                    sessionGeneration: recorder.sessionGeneration
+                )
             },
             clearSession: { peerID in
                 recorder.clearedSessions.append(peerID)
                 recorder.events.append("clearSession")
             },
+            handleAuthenticatedPeerState: { peerID, payload, generation in
+                recorder.authenticatedPeerStates.append((peerID, payload, generation))
+            },
             deliverNoisePayload: { peerID, type, payload, timestamp in
                 recorder.deliveries.append((peerID, type, payload, timestamp))
             }
@@ -152,6 +160,21 @@ struct BLENoisePacketHandlerTests {
         #expect(recorder.initiatedHandshakes.isEmpty)
     }
 
+    @Test
+    func peerIdentityMismatchDoesNotRecreateHandshakeState() {
+        let recorder = Recorder()
+        recorder.handshakeResult = .failure(NoiseSessionError.peerIdentityMismatch)
+        recorder.hasSession = false
+        let handler = makeHandler(recorder: recorder)
+        let packet = makeHandshakePacket(recipientID: Data(hexString: localPeerID.id))
+
+        #expect(!handler.handleHandshake(packet, from: remotePeerID))
+
+        #expect(recorder.hasSessionQueries.isEmpty)
+        #expect(recorder.initiatedHandshakes.isEmpty)
+        #expect(recorder.broadcastPackets.isEmpty)
+    }
+
     // MARK: Encrypted
 
     @Test
@@ -206,6 +229,25 @@ struct BLENoisePacketHandlerTests {
         #expect(recorder.initiatedHandshakes.isEmpty)
     }
 
+    @Test
+    func authenticatedPeerStateIsConsumedByTransportNotDeliveredToUI() {
+        let recorder = Recorder()
+        recorder.decryptResult = .success(Data([
+            NoisePayloadType.authenticatedPeerState.rawValue,
+            0x01, 0x02, 0x03
+        ]))
+        let handler = makeHandler(recorder: recorder)
+        let packet = makeEncryptedPacket(recipientID: Data(hexString: localPeerID.id))
+
+        handler.handleEncrypted(packet, from: remotePeerID)
+
+        #expect(recorder.authenticatedPeerStates.count == 1)
+        #expect(recorder.authenticatedPeerStates.first?.peerID == remotePeerID)
+        #expect(recorder.authenticatedPeerStates.first?.payload == Data([0x01, 0x02, 0x03]))
+        #expect(recorder.authenticatedPeerStates.first?.generation == recorder.sessionGeneration)
+        #expect(recorder.deliveries.isEmpty)
+    }
+
     @Test
     func emptyDecryptedPayloadIsIgnored() {
         let recorder = Recorder()

bitchatTests/Services/BLENoisePayloadFactoryTests.swift

@@ -1,5 +1,6 @@
 import Foundation
 import Testing
+import BitFoundation
 @testable import bitchat
 
 struct BLENoisePayloadFactoryTests {
@@ -31,4 +32,63 @@ struct BLENoisePayloadFactoryTests {
 
         #expect(payload == Data([NoisePayloadType.verifyChallenge.rawValue, 0xCA, 0xFE]))
     }
+
+    @Test
+    func privateFilePayloadPrefixesCanonicalFilePacket() throws {
+        let content = Data("%PDF-secret".utf8)
+        let file = BitchatFilePacket(
+            fileName: "secret.pdf",
+            fileSize: UInt64(content.count),
+            mimeType: "application/pdf",
+            content: content
+        )
+
+        let payload = try #require(BLENoisePayloadFactory.privateFile(file))
+
+        #expect(payload.first == 0x20, "Encrypted files must use Android's deployed wire value")
+        let decoded = try #require(BitchatFilePacket.decode(Data(payload.dropFirst())))
+        #expect(decoded.fileName == "secret.pdf")
+        #expect(decoded.mimeType == "application/pdf")
+        #expect(decoded.content == content)
+    }
+
+    @Test
+    func androidB7f0b33PrivateFilePlaintextFixtureIsByteCompatible() throws {
+        // Runtime-emitted by Android commit b7f0b33d from
+        // BitchatFilePacket("a.txt", 3, "text/plain", [01, 02, 03]) and
+        // NoisePayload(type = FILE_TRANSFER, data = file.encode()).encode().
+        let fixtureHex = "20010005612e7478740200040000000303000a746578742f706c61696e0400000003010203"
+        let fixture = try #require(Data(hexString: fixtureHex))
+
+        let typed = try #require(NoisePayload.decode(fixture))
+        #expect(typed.type == .privateFile)
+        let file = try #require(BitchatFilePacket.decode(typed.data))
+        #expect(file.fileName == "a.txt")
+        #expect(file.fileSize == 3)
+        #expect(file.mimeType == "text/plain")
+        #expect(file.content == Data([0x01, 0x02, 0x03]))
+        #expect(BLENoisePayloadFactory.privateFile(file) == fixture)
+    }
+
+    @Test
+    func prereleasePrivateFileTypeCanonicalizesOnDecode() throws {
+        let encoded = Data([NoisePayloadType.prereleasePrivateFileRawValue, 0xCA, 0xFE])
+        let decoded = try #require(NoisePayload.decode(encoded))
+
+        #expect(decoded.type == .privateFile)
+        #expect(decoded.data == Data([0xCA, 0xFE]))
+        #expect(decoded.encode().first == 0x20)
+    }
+
+    @Test
+    func authenticatedPeerStateUsesPermanent0x21Type() throws {
+        let state = AuthenticatedPeerStatePacket(
+            capabilities: .privateMedia,
+            signingPublicKey: Data(repeating: 0x77, count: 32)
+        )
+        let encoded = try #require(BLENoisePayloadFactory.authenticatedPeerState(state))
+
+        #expect(encoded.first == 0x21)
+        #expect(AuthenticatedPeerStatePacket.decode(from: Data(encoded.dropFirst())) == state)
+    }
 }

bitchatTests/Services/BLENoiseSessionQueuesTests.swift

@@ -48,7 +48,10 @@ struct BLENoiseSessionQueuesTests {
         queues.appendTypedPayload(Data([0x01]), for: peerID)
         queues.appendTypedPayload(Data([0x02]), for: peerID)
 
-        #expect(queues.takeTypedPayloads(for: peerID) == [Data([0x01]), Data([0x02])])
+        #expect(queues.takeTypedPayloads(for: peerID) == [
+            BLEPendingTypedPayload(payload: Data([0x01]), transferId: nil),
+            BLEPendingTypedPayload(payload: Data([0x02]), transferId: nil)
+        ])
         #expect(queues.takeTypedPayloads(for: peerID).isEmpty)
         #expect(queues.takePrivateMessages(for: peerID).map(\.messageID) == ["m1"])
     }
@@ -64,4 +67,21 @@ struct BLENoiseSessionQueuesTests {
 
         #expect(queues.isEmpty)
     }
+
+    @Test
+    func transferIDSurvivesHandshakeQueueAndCanBeCancelledBeforeDrain() {
+        let peerID = PeerID(str: "aaaaaaaaaaaaaaaa")
+        var queues = BLENoiseSessionQueues()
+
+        queues.appendTypedPayload(Data([0x20, 0xAA]), transferId: "media-1", for: peerID)
+        queues.appendTypedPayload(Data([0x01, 0xBB]), for: peerID)
+
+        let removed = queues.removeTypedPayload(transferId: "media-1")
+        let removedAgain = queues.removeTypedPayload(transferId: "media-1")
+        #expect(removed)
+        #expect(!removedAgain)
+        #expect(queues.takeTypedPayloads(for: peerID) == [
+            BLEPendingTypedPayload(payload: Data([0x01, 0xBB]), transferId: nil)
+        ])
+    }
 }

bitchatTests/Services/BLEOutboundFragmentPlannerTests.swift

@@ -108,6 +108,58 @@ struct BLEOutboundFragmentPlannerTests {
         ) == nil)
     }
 
+    @Test("private media v1 accepts exactly 256 fragments and rejects 257")
+    func privateMediaCrossPlatformFragmentBoundary() throws {
+        let maxPayload = makePayload(count: 160 * 1024, seed: 0xFACE_CAFE)
+
+        func plan(payloadCount: Int) throws -> BLEOutboundFragmentPlan {
+            let packet = BitchatPacket(
+                type: MessageType.noiseEncrypted.rawValue,
+                senderID: Data(hexString: "0011223344556677") ?? Data(),
+                recipientID: Data(hexString: "8877665544332211"),
+                timestamp: 0x0102030405,
+                payload: Data(maxPayload.prefix(payloadCount)),
+                signature: nil,
+                ttl: 3,
+                version: 2
+            )
+            return try #require(BLEOutboundFragmentPlanner.makePlan(
+                for: BLEOutboundFragmentTransferRequest(
+                    packet: packet,
+                    pad: false,
+                    maxChunk: nil,
+                    directedPeer: PeerID(str: "8877665544332211"),
+                    transferId: "boundary"
+                ),
+                defaultChunkSize: TransportConfig.bleDefaultFragmentSize,
+                bleMaxMTU: 512,
+                fragmentID: Data(repeating: 0xD4, count: 8)
+            ))
+        }
+
+        func firstPlan(withAtLeast target: Int) throws -> BLEOutboundFragmentPlan {
+            var low = 1
+            var high = maxPayload.count
+            while low < high {
+                let mid = low + (high - low) / 2
+                if try plan(payloadCount: mid).totalFragments >= target {
+                    high = mid
+                } else {
+                    low = mid + 1
+                }
+            }
+            return try plan(payloadCount: low)
+        }
+
+        let at256 = try firstPlan(withAtLeast: 256)
+        let at257 = try firstPlan(withAtLeast: 257)
+
+        #expect(at256.totalFragments == 256)
+        #expect(BLEOutboundFragmentPlanner.isPrivateMediaV1Compatible(at256))
+        #expect(at257.totalFragments == 257)
+        #expect(!BLEOutboundFragmentPlanner.isPrivateMediaV1Compatible(at257))
+    }
+
     private func makePacket(
         payload: Data,
         route: [Data]? = nil,

bitchatTests/Services/BLEOutboundFragmentTransferSchedulerTests.swift

@@ -20,6 +20,24 @@ struct BLEOutboundFragmentTransferSchedulerTests {
         }
     }
 
+    @Test
+    func explicitTransferIDReservesEncryptedPrivateFileFragments() {
+        var scheduler = BLEOutboundFragmentTransferScheduler()
+        let request = makeRequest(
+            type: MessageType.noiseEncrypted.rawValue,
+            transferId: "private-media"
+        )
+
+        let result = scheduler.submit(request, maxConcurrentTransfers: 1)
+
+        if case let .start(_, reservedTransferId) = result {
+            #expect(reservedTransferId == "private-media")
+            #expect(scheduler.activeCount == 1)
+        } else {
+            Issue.record("Expected encrypted private media to reserve its progress slot")
+        }
+    }
+
     @Test
     func submitQueuesFileTransferWhenSlotsAreFull() {
         var scheduler = BLEOutboundFragmentTransferScheduler()

bitchatTests/Services/BLEPeerRegistryTests.swift

@@ -42,6 +42,37 @@ struct BLEPeerRegistryTests {
         #expect(registry.info(for: peerID)?.nickname == "alice-renamed")
     }
 
+    @Test("registry preserves absent versus explicit empty capabilities")
+    func capabilitiesPresenceIsPreserved() {
+        var registry = BLEPeerRegistry()
+        let oldPeer = PeerID(str: "1122334455667788")
+        let modernPeer = PeerID(str: "8877665544332211")
+
+        _ = registry.upsertVerifiedAnnounce(
+            peerID: oldPeer,
+            nickname: "old",
+            noisePublicKey: Data(repeating: 0x11, count: 32),
+            signingPublicKey: Data(repeating: 0x12, count: 32),
+            isConnected: true,
+            now: Date(),
+            capabilities: nil
+        )
+        _ = registry.upsertVerifiedAnnounce(
+            peerID: modernPeer,
+            nickname: "modern",
+            noisePublicKey: Data(repeating: 0x21, count: 32),
+            signingPublicKey: Data(repeating: 0x22, count: 32),
+            isConnected: true,
+            now: Date(),
+            capabilities: []
+        )
+
+        #expect(registry.capabilities(for: oldPeer).isEmpty)
+        #expect(!registry.capabilitiesWereExplicitlyAdvertised(for: oldPeer))
+        #expect(registry.capabilities(for: modernPeer).isEmpty)
+        #expect(registry.capabilitiesWereExplicitlyAdvertised(for: modernPeer))
+    }
+
     @Test("reachability keeps recent verified offline peers only when mesh is attached")
     func reachabilityRequiresMeshAttachmentForOfflinePeers() {
         let offlinePeer = PeerID(str: "1122334455667788")

bitchatTests/Services/NoiseEncryptionServiceTests.swift

@@ -91,39 +91,266 @@ struct NoiseEncryptionServiceTests {
     func handshakeEncryptionAndFingerprintLifecycle() async throws {
         let alice = NoiseEncryptionService(keychain: MockKeychain())
         let bob = NoiseEncryptionService(keychain: MockKeychain())
-        let alicePeerID = PeerID(str: "0011223344556677")
-        let bobPeerID = PeerID(str: "8899aabbccddeeff")
+        let alicePeerID = PeerID(publicKey: alice.getStaticPublicKeyData())
+        let bobPeerID = PeerID(publicKey: bob.getStaticPublicKeyData())
         let recorder = AuthenticationRecorder()
 
         #expect(alice.onPeerAuthenticated == nil)
+        #expect(bob.onPeerAuthenticatedWithGeneration == nil)
         alice.addOnPeerAuthenticatedHandler(recorder.record(peerID:fingerprint:))
         bob.onPeerAuthenticated = recorder.record(peerID:fingerprint:)
+        bob.onPeerAuthenticatedWithGeneration = recorder.record(
+            peerID:fingerprint:sessionGeneration:
+        )
 
-        try establishSessions(alice: alice, bob: bob, alicePeerID: alicePeerID, bobPeerID: bobPeerID)
+        try establishSessions(alice: alice, bob: bob)
 
         let authenticated = await TestHelpers.waitUntil({ recorder.count >= 2 }, timeout: 5.0)
         #expect(authenticated)
-        #expect(alice.hasEstablishedSession(with: alicePeerID))
-        #expect(bob.hasEstablishedSession(with: bobPeerID))
-        #expect(alice.hasSession(with: alicePeerID))
-        #expect(bob.hasSession(with: bobPeerID))
-        #expect(alice.getPeerPublicKeyData(alicePeerID)?.count == 32)
-        #expect(bob.getPeerPublicKeyData(bobPeerID)?.count == 32)
-        #expect(alice.getPeerFingerprint(alicePeerID) != nil)
-        #expect(bob.getPeerFingerprint(bobPeerID) != nil)
+        let generationAuthenticated = await TestHelpers.waitUntil(
+            { recorder.generationCount >= 1 },
+            timeout: 5.0
+        )
+        #expect(generationAuthenticated)
+        #expect(alice.hasEstablishedSession(with: bobPeerID))
+        #expect(bob.hasEstablishedSession(with: alicePeerID))
+        #expect(alice.hasSession(with: bobPeerID))
+        #expect(bob.hasSession(with: alicePeerID))
+        #expect(alice.getPeerPublicKeyData(bobPeerID)?.count == 32)
+        #expect(bob.getPeerPublicKeyData(alicePeerID)?.count == 32)
+        #expect(alice.getPeerFingerprint(bobPeerID) != nil)
+        #expect(bob.getPeerFingerprint(alicePeerID) != nil)
+        #expect(recorder.generation(for: alicePeerID) == bob.sessionGeneration(for: alicePeerID))
 
         let plaintext = Data("secret payload".utf8)
-        let ciphertext = try alice.encrypt(plaintext, for: alicePeerID)
-        let decrypted = try bob.decrypt(ciphertext, from: bobPeerID)
+        let ciphertext = try alice.encrypt(plaintext, for: bobPeerID)
+        let decrypted = try bob.decrypt(ciphertext, from: alicePeerID)
         #expect(decrypted == plaintext)
 
-        alice.clearSession(for: alicePeerID)
-        #expect(!alice.hasSession(with: alicePeerID))
-        #expect(alice.getPeerFingerprint(alicePeerID) == nil)
+        alice.clearSession(for: bobPeerID)
+        #expect(!alice.hasSession(with: bobPeerID))
+        #expect(alice.getPeerFingerprint(bobPeerID) == nil)
 
         bob.clearEphemeralStateForPanic()
-        #expect(!bob.hasSession(with: bobPeerID))
-        #expect(bob.getPeerFingerprint(bobPeerID) == nil)
+        #expect(!bob.hasSession(with: alicePeerID))
+        #expect(bob.getPeerFingerprint(alicePeerID) == nil)
+    }
+
+    @Test("Handshake rejects a claimed peer ID that does not match the authenticated static key")
+    func handshakeRejectsClaimedPeerIDStaticKeyMismatch() async throws {
+        let receiver = NoiseEncryptionService(keychain: MockKeychain())
+        let claimedAlice = NoiseEncryptionService(keychain: MockKeychain())
+        let mallory = NoiseEncryptionService(keychain: MockKeychain())
+        let receiverPeerID = PeerID(publicKey: receiver.getStaticPublicKeyData())
+        let claimedAlicePeerID = PeerID(publicKey: claimedAlice.getStaticPublicKeyData())
+        let recorder = AuthenticationRecorder()
+        receiver.addOnPeerAuthenticatedHandler(recorder.record(peerID:fingerprint:))
+
+        let message1 = try mallory.initiateHandshake(with: receiverPeerID)
+        let message2 = try #require(
+            try receiver.processHandshakeMessage(from: claimedAlicePeerID, message: message1)
+        )
+        let message3 = try #require(
+            try mallory.processHandshakeMessage(from: receiverPeerID, message: message2)
+        )
+
+        do {
+            _ = try receiver.processHandshakeMessage(from: claimedAlicePeerID, message: message3)
+            Issue.record("Expected the authenticated Mallory key to be rejected for Alice's peer ID")
+        } catch let error as NoiseSessionError {
+            #expect(error == .peerIdentityMismatch)
+        } catch {
+            Issue.record("Unexpected mismatch error: \(error)")
+        }
+
+        #expect(!receiver.hasSession(with: claimedAlicePeerID))
+        let emittedAuthentication = await TestHelpers.waitUntil(
+            { recorder.count > 0 },
+            timeout: TestConstants.shortTimeout
+        )
+        #expect(!emittedAuthentication)
+    }
+
+    @Test("Failed forged replacement preserves the established peer session")
+    func forgedReplacementPreservesEstablishedSession() async throws {
+        let alice = NoiseEncryptionService(keychain: MockKeychain())
+        let receiver = NoiseEncryptionService(keychain: MockKeychain())
+        let mallory = NoiseEncryptionService(keychain: MockKeychain())
+        let alicePeerID = PeerID(publicKey: alice.getStaticPublicKeyData())
+        let receiverPeerID = PeerID(publicKey: receiver.getStaticPublicKeyData())
+        let recorder = AuthenticationRecorder()
+        receiver.addOnPeerAuthenticatedHandler(recorder.record(peerID:fingerprint:))
+
+        try establishSessions(alice: alice, bob: receiver)
+        let initialAuthentication = await TestHelpers.waitUntil(
+            { recorder.count == 1 },
+            timeout: TestConstants.longTimeout
+        )
+        #expect(initialAuthentication)
+
+        let before = try alice.encrypt(Data("before".utf8), for: receiverPeerID)
+        #expect(try receiver.decrypt(before, from: alicePeerID) == Data("before".utf8))
+
+        let forgedMessage1 = try mallory.initiateHandshake(with: receiverPeerID)
+        let forgedMessage2 = try #require(
+            try receiver.processHandshakeMessage(from: alicePeerID, message: forgedMessage1)
+        )
+        // The replacement has not authenticated yet; the working Alice
+        // transport session must remain available throughout the candidate.
+        #expect(receiver.hasEstablishedSession(with: alicePeerID))
+        let forgedMessage3 = try #require(
+            try mallory.processHandshakeMessage(from: receiverPeerID, message: forgedMessage2)
+        )
+
+        do {
+            _ = try receiver.processHandshakeMessage(from: alicePeerID, message: forgedMessage3)
+            Issue.record("Expected forged replacement to fail peer binding")
+        } catch let error as NoiseSessionError {
+            #expect(error == .peerIdentityMismatch)
+        } catch {
+            Issue.record("Unexpected replacement error: \(error)")
+        }
+
+        #expect(receiver.hasEstablishedSession(with: alicePeerID))
+        let after = try alice.encrypt(Data("after".utf8), for: receiverPeerID)
+        #expect(try receiver.decrypt(after, from: alicePeerID) == Data("after".utf8))
+        let emittedReplacementAuthentication = await TestHelpers.waitUntil(
+            { recorder.count > 1 },
+            timeout: TestConstants.shortTimeout
+        )
+        #expect(!emittedReplacementAuthentication)
+    }
+
+    @Test("Valid rehandshake atomically replaces the established session")
+    func validRehandshakeReplacesEstablishedSession() throws {
+        let alice = NoiseEncryptionService(keychain: MockKeychain())
+        let receiver = NoiseEncryptionService(keychain: MockKeychain())
+        let alicePeerID = PeerID(publicKey: alice.getStaticPublicKeyData())
+        let receiverPeerID = PeerID(publicKey: receiver.getStaticPublicKeyData())
+
+        try establishSessions(alice: alice, bob: receiver)
+        alice.clearSession(for: receiverPeerID)
+
+        let message1 = try alice.initiateHandshake(with: receiverPeerID)
+        let message2 = try #require(
+            try receiver.processHandshakeMessage(from: alicePeerID, message: message1)
+        )
+        #expect(receiver.hasEstablishedSession(with: alicePeerID))
+        let message3 = try #require(
+            try alice.processHandshakeMessage(from: receiverPeerID, message: message2)
+        )
+        _ = try receiver.processHandshakeMessage(from: alicePeerID, message: message3)
+
+        #expect(alice.hasEstablishedSession(with: receiverPeerID))
+        #expect(receiver.hasEstablishedSession(with: alicePeerID))
+        let ciphertext = try alice.encrypt(Data("new session".utf8), for: receiverPeerID)
+        #expect(try receiver.decrypt(ciphertext, from: alicePeerID) == Data("new session".utf8))
+    }
+
+    @Test("Automatic rekey exposes and completes its exact handshake bytes")
+    func automaticRekeyHandshakeIsNotStranded() throws {
+        let alice = NoiseEncryptionService(keychain: MockKeychain())
+        let bob = NoiseEncryptionService(keychain: MockKeychain())
+        let alicePeerID = PeerID(publicKey: alice.getStaticPublicKeyData())
+        let bobPeerID = PeerID(publicKey: bob.getStaticPublicKeyData())
+        try establishSessions(alice: alice, bob: bob)
+        let originalGeneration = try #require(alice.sessionGeneration(for: bobPeerID))
+        var leaseRan = false
+        let leased = alice.withCurrentSessionGeneration(
+            for: bobPeerID,
+            expected: originalGeneration
+        ) {
+            leaseRan = true
+            return true
+        }
+        #expect(leased == true)
+        #expect(leaseRan)
+
+        var emittedPeerID: PeerID?
+        var emittedMessage: Data?
+        alice.onRekeyHandshakeReady = { peerID, message in
+            emittedPeerID = peerID
+            emittedMessage = message
+        }
+        try alice._test_initiateAutomaticRekey(for: bobPeerID)
+
+        #expect(emittedPeerID == bobPeerID)
+        #expect(alice.sessionGeneration(for: bobPeerID) == nil)
+        leaseRan = false
+        let staleLease = alice.withCurrentSessionGeneration(
+            for: bobPeerID,
+            expected: originalGeneration
+        ) {
+            leaseRan = true
+            return true
+        }
+        #expect(staleLease == nil)
+        #expect(!leaseRan)
+        let message1 = try #require(emittedMessage)
+        #expect(!message1.isEmpty)
+        #expect(alice.hasSession(with: bobPeerID))
+        #expect(!alice.hasEstablishedSession(with: bobPeerID))
+
+        let message2 = try #require(
+            try bob.processHandshakeMessage(from: alicePeerID, message: message1)
+        )
+        let message3 = try #require(
+            try alice.processHandshakeMessage(from: bobPeerID, message: message2)
+        )
+        _ = try bob.processHandshakeMessage(from: alicePeerID, message: message3)
+
+        #expect(alice.hasEstablishedSession(with: bobPeerID))
+        #expect(bob.hasEstablishedSession(with: alicePeerID))
+        #expect(alice.sessionGeneration(for: bobPeerID) != originalGeneration)
+    }
+
+    @Test("Large private-file payloads use the bounded Noise extension")
+    func largePrivateFileNoiseRoundTrip() throws {
+        let alice = NoiseEncryptionService(keychain: MockKeychain())
+        let bob = NoiseEncryptionService(keychain: MockKeychain())
+        let alicePeerID = PeerID(publicKey: alice.getStaticPublicKeyData())
+        let bobPeerID = PeerID(publicKey: bob.getStaticPublicKeyData())
+        try establishSessions(alice: alice, bob: bob)
+
+        let content = Data("%PDF-1.7\n".utf8) + Data(repeating: 0x51, count: 96 * 1024)
+        let file = BitchatFilePacket(
+            fileName: "large-private.pdf",
+            fileSize: UInt64(content.count),
+            mimeType: "application/pdf",
+            content: content
+        )
+        let typedPayload = try #require(BLENoisePayloadFactory.privateFile(file))
+        #expect(typedPayload.count > NoiseSecurityConstants.maxMessageSize)
+        #expect(typedPayload.first == NoisePayloadType.privateFile.rawValue)
+        #expect(
+            typedPayload.count <= NoiseSecurityConstants.maxPrivateFilePlaintextSize,
+            "typedBytes=\(typedPayload.count) limit=\(NoiseSecurityConstants.maxPrivateFilePlaintextSize)"
+        )
+
+        do {
+            _ = try alice.encrypt(typedPayload, for: bobPeerID)
+            Issue.record("Ordinary Noise payload path must retain its 64 KiB ceiling")
+        } catch NoiseSecurityError.messageTooLarge {
+            // Expected: only the purpose-specific private-file API may extend it.
+        }
+
+        let ciphertext: Data
+        do {
+            ciphertext = try alice.encryptPrivateFilePayload(typedPayload, for: bobPeerID)
+        } catch {
+            Issue.record("Private-file encryption failed: \(error)")
+            return
+        }
+        let decrypted: Data
+        do {
+            decrypted = try bob.decrypt(ciphertext, from: alicePeerID)
+        } catch {
+            Issue.record("Private-file decryption failed: \(error); ciphertextBytes=\(ciphertext.count)")
+            return
+        }
+
+        #expect(ciphertext.range(of: content) == nil)
+        #expect(decrypted == typedPayload)
     }
 
     @Test("Encrypt without a session requests handshake and decrypt without session fails")
@@ -200,16 +427,16 @@ struct NoiseEncryptionServiceTests {
 
     private func establishSessions(
         alice: NoiseEncryptionService,
-        bob: NoiseEncryptionService,
-        alicePeerID: PeerID,
-        bobPeerID: PeerID
+        bob: NoiseEncryptionService
     ) throws {
-        let message1 = try alice.initiateHandshake(with: alicePeerID)
-        let response = try bob.processHandshakeMessage(from: bobPeerID, message: message1)
+        let alicePeerID = PeerID(publicKey: alice.getStaticPublicKeyData())
+        let bobPeerID = PeerID(publicKey: bob.getStaticPublicKeyData())
+        let message1 = try alice.initiateHandshake(with: bobPeerID)
+        let response = try bob.processHandshakeMessage(from: alicePeerID, message: message1)
         let message2 = try #require(response, "Expected handshake response")
-        let final = try alice.processHandshakeMessage(from: alicePeerID, message: message2)
+        let final = try alice.processHandshakeMessage(from: bobPeerID, message: message2)
         let message3 = try #require(final, "Expected handshake final")
-        let finalMessage = try bob.processHandshakeMessage(from: bobPeerID, message: message3)
+        let finalMessage = try bob.processHandshakeMessage(from: alicePeerID, message: message3)
         #expect(finalMessage == nil)
     }
 }
@@ -217,6 +444,7 @@ struct NoiseEncryptionServiceTests {
 private final class AuthenticationRecorder: @unchecked Sendable {
     private let lock = NSLock()
     private var entries: [(PeerID, String)] = []
+    private var generationEntries: [(PeerID, UUID)] = []
 
     var count: Int {
         lock.lock()
@@ -224,9 +452,27 @@ private final class AuthenticationRecorder: @unchecked Sendable {
         return entries.count
     }
 
+    var generationCount: Int {
+        lock.lock()
+        defer { lock.unlock() }
+        return generationEntries.count
+    }
+
     func record(peerID: PeerID, fingerprint: String) {
         lock.lock()
         entries.append((peerID, fingerprint))
         lock.unlock()
     }
+
+    func record(peerID: PeerID, fingerprint _: String, sessionGeneration: UUID) {
+        lock.lock()
+        generationEntries.append((peerID, sessionGeneration))
+        lock.unlock()
+    }
+
+    func generation(for peerID: PeerID) -> UUID? {
+        lock.lock()
+        defer { lock.unlock() }
+        return generationEntries.last { $0.0 == peerID }?.1
+    }
 }

bitchatTests/Services/SecureIdentityStateManagerTests.swift

@@ -399,6 +399,59 @@ final class SecureIdentityStateManagerTests: XCTestCase {
         XCTAssertTrue(cleared)
     }
 
+    func test_privateMediaCapabilityPinPersistsMonotonicallyAndPanicClearRemovesIt() async {
+        let keychain = MockKeychain()
+        let fingerprint = Data(repeating: 0x42, count: 32).sha256Fingerprint()
+        let manager = SecureIdentityStateManager(keychain)
+
+        XCTAssertFalse(manager.hasObservedPrivateMediaCapability(fingerprint: fingerprint))
+        manager.markPrivateMediaCapable(fingerprint: fingerprint)
+        XCTAssertTrue(
+            manager.hasObservedPrivateMediaCapability(fingerprint: fingerprint),
+            "pin insertion must be synchronously visible to the next downgrade decision"
+        )
+
+        // Re-marking is idempotent, and the encrypted cache carries the pin
+        // across launches.
+        manager.markPrivateMediaCapable(fingerprint: fingerprint)
+        manager.forceSave()
+        let reloaded = SecureIdentityStateManager(keychain)
+        XCTAssertTrue(reloaded.hasObservedPrivateMediaCapability(fingerprint: fingerprint))
+
+        // ChatViewModel's panic path calls this same wipe after deleting
+        // keychain data; the in-memory pin must disappear immediately too.
+        reloaded.clearAllIdentityData()
+        let cleared = await waitUntil {
+            !reloaded.hasObservedPrivateMediaCapability(fingerprint: fingerprint)
+        }
+        XCTAssertTrue(cleared)
+    }
+
+    func test_noiseAuthenticatedSigningKeyBindingPersistsAndPanicClearRemovesIt() async {
+        let keychain = MockKeychain()
+        let fingerprint = Data(repeating: 0x31, count: 32).sha256Fingerprint()
+        let firstKey = Data(repeating: 0x41, count: 32)
+        let rotatedKey = Data(repeating: 0x42, count: 32)
+        let manager = SecureIdentityStateManager(keychain)
+
+        manager.bindAuthenticatedSigningPublicKey(firstKey, fingerprint: fingerprint)
+        XCTAssertEqual(manager.authenticatedSigningPublicKey(forFingerprint: fingerprint), firstKey)
+        // A later authenticated Noise session may legitimately rotate the
+        // announcement signing key.
+        manager.bindAuthenticatedSigningPublicKey(rotatedKey, fingerprint: fingerprint)
+        XCTAssertEqual(manager.authenticatedSigningPublicKey(forFingerprint: fingerprint), rotatedKey)
+
+        manager.forceSave()
+        let reloaded = SecureIdentityStateManager(keychain)
+        XCTAssertEqual(reloaded.authenticatedSigningPublicKey(forFingerprint: fingerprint), rotatedKey)
+
+        reloaded.clearAllIdentityData()
+        let cleared = await waitUntil {
+            reloaded.authenticatedSigningPublicKey(forFingerprint: fingerprint) == nil
+        }
+        XCTAssertTrue(cleared)
+    }
+
     func test_forceSave_withFailingCacheWriteDoesNotPersistCache() async {
         let keychain = FailingCacheSaveKeychain()
         let manager = SecureIdentityStateManager(keychain)

bitchatTests/Services/TransferProgressManagerTests.swift

@@ -49,7 +49,7 @@ struct TransferProgressManagerTests {
                 recorder.append("updated:\(id):\(sent):\(total)")
             case .completed(let id, let total):
                 recorder.append("completed:\(id):\(total)")
-            case .cancelled:
+            case .cancelled, .rejected:
                 break
             }
         }
@@ -85,7 +85,7 @@ struct TransferProgressManagerTests {
                 recorder.append("started:\(id):\(total)")
             case .cancelled(let id, let sent, let total):
                 recorder.append("cancelled:\(id):\(sent):\(total)")
-            case .updated, .completed:
+            case .updated, .completed, .rejected:
                 break
             }
         }
@@ -105,6 +105,28 @@ struct TransferProgressManagerTests {
         #expect(manager.snapshot(id: transferID) == nil)
         _ = cancellable
     }
+
+    @Test("Preflight policy rejection publishes a visible failure reason")
+    @MainActor
+    func rejectBeforeStartPublishesReason() async {
+        let manager = TransferProgressManager()
+        let transferID = "transfer-visible-reject"
+        let recorder = EventRecorder()
+        let cancellable = manager.publisher.sink { event in
+            if case .rejected(let id, let reason) = event {
+                recorder.append("rejected:\(id):\(reason)")
+            }
+        }
+
+        manager.rejectBeforeStart(id: transferID, reason: "upgrade required")
+
+        let didReceive = await TestHelpers.waitUntil({
+            recorder.values == ["rejected:\(transferID):upgrade required"]
+        }, timeout: 5.0)
+        #expect(didReceive)
+        #expect(manager.snapshot(id: transferID) == nil)
+        _ = cancellable
+    }
 }
 
 private final class EventRecorder: @unchecked Sendable {

bitchatTests/Services/UnifiedPeerServiceTests.swift

@@ -266,6 +266,11 @@ private final class TestIdentityManager: SecureIdentityStateManagerProtocol {
         verified.removeAll()
     }
 
+    func markPrivateMediaCapable(fingerprint: String) {}
+    func hasObservedPrivateMediaCapability(fingerprint: String) -> Bool { false }
+    func bindAuthenticatedSigningPublicKey(_ signingPublicKey: Data, fingerprint: String) {}
+    func authenticatedSigningPublicKey(forFingerprint fingerprint: String) -> Data? { nil }
+
     func removeEphemeralSession(peerID: PeerID) {}
 
     func setVerified(fingerprint: String, verified: Bool) {

docs/PRIVATE-MEDIA-MIGRATION.md

@@ -0,0 +1,107 @@
+# Private-media wire migration
+
+Private files use the `BitchatFilePacket` TLV shared by iOS and Android. The
+preferred direct-message wire form encrypts that complete TLV inside the
+peer's Noise session before BLE fragmentation.
+
+## Wire values and capability
+
+- `NoisePayloadType.privateFile` is `0x20`, the value already deployed by the
+  Android client. New sends must use this value.
+- iOS temporarily accepts `0x09`, which appeared in prerelease builds of the
+  private-media change. Decoders canonicalize it to `privateFile`; they never
+  emit it.
+- `NoisePayloadType.authenticatedPeerState` is permanently assigned `0x21`.
+  It is emitted after every completed/rekeyed Noise XX session and echoed at
+  most once when the remote state arrives, so message-3/proof reordering over
+  different mesh links converges. This type is part of the protocol security
+  boundary and is not removed when the media migration ends.
+- The `0x21` payload starts with version `0x01`, followed by one-byte
+  type/length/value fields. Version 1 requires canonical TLV `0x01` (the
+  minimal little-endian `PeerCapabilities` bitfield, 1-8 bytes) and TLV `0x02`
+  (the 32-byte Ed25519 announcement signing key). Duplicate required fields,
+  non-minimal capabilities, malformed lengths, missing fields, and unknown
+  versions are ignored without changing state. Unknown TLVs are skipped.
+- The public `PeerCapabilities.privateMedia` announce bit is a discovery hint:
+  it starts a Noise handshake, but never selects encrypted sending or creates
+  a pin. A private transfer waits boundedly for the exact session's encrypted
+  `0x21`. A valid bit-8 proof selects Noise `0x20`; a valid no-bit proof or a
+  no-proof timeout reaches the explicit legacy-consent path for an unpinned
+  peer. No timeout automatically sends raw bytes.
+- An unpinned peer with a stable Noise key but without that capability is
+  eligible for one signed, directed
+  `fileTransfer`, matching the pre-migration wire form used by older iOS and
+  accepted by current Android clients, only after the sender confirms a
+  per-send warning that the file is not end-to-end encrypted and mesh relays
+  can see it. The
+  consent is consumed by that invocation and is never remembered.
+- A signed announce never creates a pin by itself: an attacker can copy a
+  victim's public Noise key, supply its own Ed25519 key and capability bits,
+  and self-sign an internally consistent announce. Only successfully
+  decrypted `0x21` state pins the authenticated Noise fingerprint and binds
+  the Ed25519 key used by later announces/public messages. A later valid
+  no-bit `0x21` is treated as a downgrade, and raw fallback is blocked even if
+  a caller presents legacy consent. Public no-bit announces cannot overwrite
+  current session-authenticated state.
+- During migration, both an absent capabilities TLV and an explicit TLV
+  without `privateMedia` are legacy-eligible when that stable fingerprint is
+  not pinned. This supports clients that added capability advertisement before
+  encrypted media. Neither shape bypasses a previously authenticated pin.
+
+Older clients decrypt and ignore unknown inner type `0x21`; they do not need to
+understand it to continue using text or the warned legacy media path. They are
+never inferred capable merely because the handshake succeeded.
+
+Removal gates are independent and must not share an arbitrary calendar date:
+
+- Remove the `0x09` receive alias only after every TestFlight/internal build
+  that emitted it has expired and minimum-supported-client policy excludes it.
+- Remove the signed directed raw `0x22` fallback only after minimum-supported
+  iOS and Android clients emit authenticated bit-8 `0x21` state and the legacy
+  population has aged out.
+- Nostr kind `1059` compatibility is a separate envelope migration. Its dual
+  publish/removal gate is not evidence that either BLE compatibility shape can
+  be removed.
+
+## Security boundary
+
+The encrypted form provides Noise confidentiality and peer authentication.
+The fallback is signed and its signature is required on receive, so relays
+cannot forge its sender or contents. It is not confidential: relays can see
+the raw file TLV. The UI says this explicitly and asks on every send. A peer
+without a stable Noise key from a verified registry entry cannot use the
+fallback. Keep it only for the mixed-version migration, and remove it only
+after minimum-supported Android and iOS releases emit authenticated bit-8
+`0x21` state and the legacy population has aged out. Never replace it with an
+unsigned fallback, persist blanket consent, or send both forms.
+
+Incoming clients accept all three migration-era shapes:
+
+| Sender | Inbound form | Result |
+| --- | --- | --- |
+| Current Android | Noise `0x20` | Decrypt and deliver |
+| Prerelease iOS | Noise `0x09` | Decrypt, canonicalize, and deliver |
+| Older client | Signed directed `fileTransfer` | Verify signature and deliver |
+| Forged/unsigned raw sender | Directed `fileTransfer` | Reject |
+
+Panic wipe clears the persistent capability pins together with the rest of
+the encrypted identity cache.
+
+This migration path is mesh-Noise-only (BLE and compatible direct mesh links).
+Nostr private-media transport is unchanged and remains a follow-up. Nostr
+inbound paths explicitly ignore `0x21`; do not infer the mesh consent fallback
+or capability-pin semantics for Nostr delivery.
+
+## Size interoperability
+
+iOS bounds inbound file content at 1 MiB and applies the expanded allocation
+budget only after a large Noise ciphertext authenticates to `0x20` or the
+temporary `0x09` alias. Ordinary Noise messages retain their 64 KiB limit.
+
+Current Android builds cap each reassembly at 256 fragments. Depending on the
+negotiated BLE packet size and routing overhead, that is roughly 110-120 KiB,
+well below iOS's absolute inbound ceiling. Private-media v1 therefore runs the
+actual route-aware BLE fragment planner before both encrypted and consented
+legacy sends and rejects any plan above 256 fragments with a visible failure.
+This fragment-count contract, rather than a guessed byte threshold, stays
+correct as route overhead changes.

localPackages/BitFoundation/Sources/BitFoundation/PeerCapabilities.swift

@@ -24,6 +24,10 @@ public struct PeerCapabilities: OptionSet, Equatable, Hashable, Sendable {
     /// (uplink/downlink carriers for mesh-only peers). Advertised alongside
     /// a `bridgeGeohash` TLV carrying the rendezvous cell.
     public static let bridge = PeerCapabilities(rawValue: 1 << 7)
+    /// Finalized direct-message media encrypted as Noise payload `0x20`
+    /// before outer BLE fragmentation. Peers that omit this bit require the
+    /// signed directed raw-file migration fallback.
+    public static let privateMedia = PeerCapabilities(rawValue: 1 << 8)
 
     /// Minimal little-endian byte encoding; always at least one byte so an
     /// empty set is distinguishable from an absent TLV.

localPackages/BitFoundation/Tests/BitFoundationTests/PeerCapabilitiesTests.swift

@@ -16,11 +16,12 @@ struct PeerCapabilitiesTests {
         #expect(PeerCapabilities([]).encoded() == Data([0x00]))
         #expect(PeerCapabilities.prekeys.encoded() == Data([0x01]))
         #expect(PeerCapabilities.meshDiagnostics.encoded() == Data([0x40]))
+        #expect(PeerCapabilities.privateMedia.encoded() == Data([0x00, 0x01]))
 
         let high = PeerCapabilities(rawValue: 1 << 9)
         #expect(high.encoded() == Data([0x00, 0x02]))
 
-        let all: PeerCapabilities = [.prekeys, .wifiBulk, .gateway, .groups, .board, .vouch, .meshDiagnostics]
+        let all: PeerCapabilities = [.prekeys, .wifiBulk, .gateway, .groups, .board, .vouch, .meshDiagnostics, .privateMedia]
         #expect(PeerCapabilities(encoded: all.encoded()) == all)
         #expect(PeerCapabilities(encoded: high.encoded()) == high)
         #expect(PeerCapabilities(encoded: PeerCapabilities([]).encoded()) == [])