Extract Noise into a dedicated module

This commit is contained in:
islam
2026-04-14 20:16:45 +01:00
parent 4cfcefcda6
commit e8fb4a6333
26 changed files with 209 additions and 53 deletions
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-96
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@@ -1,96 +0,0 @@
//
// NoiseRateLimiter.swift
// bitchat
//
// This is free and unencumbered software released into the public domain.
// For more information, see <https://unlicense.org>
//
import BitLogger
import BitFoundation
import Foundation
final class NoiseRateLimiter {
private var handshakeTimestamps: [PeerID: [Date]] = [:]
private var messageTimestamps: [PeerID: [Date]] = [:]
// Global rate limiting
private var globalHandshakeTimestamps: [Date] = []
private var globalMessageTimestamps: [Date] = []
private let queue = DispatchQueue(label: "chat.bitchat.noise.ratelimit", attributes: .concurrent)
func allowHandshake(from peerID: PeerID) -> Bool {
return queue.sync(flags: .barrier) {
let now = Date()
let oneMinuteAgo = now.addingTimeInterval(-60)
// Check global rate limit first
globalHandshakeTimestamps = globalHandshakeTimestamps.filter { $0 > oneMinuteAgo }
if globalHandshakeTimestamps.count >= NoiseSecurityConstants.maxGlobalHandshakesPerMinute {
SecureLogger.warning("Global handshake rate limit exceeded: \(globalHandshakeTimestamps.count)/\(NoiseSecurityConstants.maxGlobalHandshakesPerMinute) per minute", category: .security)
return false
}
// Check per-peer rate limit
var timestamps = handshakeTimestamps[peerID] ?? []
timestamps = timestamps.filter { $0 > oneMinuteAgo }
if timestamps.count >= NoiseSecurityConstants.maxHandshakesPerMinute {
SecureLogger.warning("Per-peer handshake rate limit exceeded for \(peerID): \(timestamps.count)/\(NoiseSecurityConstants.maxHandshakesPerMinute) per minute", category: .security)
return false
}
// Record new handshake
timestamps.append(now)
handshakeTimestamps[peerID] = timestamps
globalHandshakeTimestamps.append(now)
return true
}
}
func allowMessage(from peerID: PeerID) -> Bool {
return queue.sync(flags: .barrier) {
let now = Date()
let oneSecondAgo = now.addingTimeInterval(-1)
// Check global rate limit first
globalMessageTimestamps = globalMessageTimestamps.filter { $0 > oneSecondAgo }
if globalMessageTimestamps.count >= NoiseSecurityConstants.maxGlobalMessagesPerSecond {
SecureLogger.warning("Global message rate limit exceeded: \(globalMessageTimestamps.count)/\(NoiseSecurityConstants.maxGlobalMessagesPerSecond) per second", category: .security)
return false
}
// Check per-peer rate limit
var timestamps = messageTimestamps[peerID] ?? []
timestamps = timestamps.filter { $0 > oneSecondAgo }
if timestamps.count >= NoiseSecurityConstants.maxMessagesPerSecond {
SecureLogger.warning("Per-peer message rate limit exceeded for \(peerID): \(timestamps.count)/\(NoiseSecurityConstants.maxMessagesPerSecond) per second", category: .security)
return false
}
// Record new message
timestamps.append(now)
messageTimestamps[peerID] = timestamps
globalMessageTimestamps.append(now)
return true
}
}
func reset(for peerID: PeerID) {
queue.async(flags: .barrier) {
self.handshakeTimestamps.removeValue(forKey: peerID)
self.messageTimestamps.removeValue(forKey: peerID)
}
}
func resetAll() {
queue.async(flags: .barrier) {
self.handshakeTimestamps.removeAll()
self.messageTimestamps.removeAll()
self.globalHandshakeTimestamps.removeAll()
self.globalMessageTimestamps.removeAll()
}
}
}
@@ -1,37 +0,0 @@
//
// NoiseSecurityConstants.swift
// bitchat
//
// This is free and unencumbered software released into the public domain.
// For more information, see <https://unlicense.org>
//
import Foundation
enum NoiseSecurityConstants {
// Maximum message size to prevent memory exhaustion
static let maxMessageSize = 65535 // 64KB as per Noise spec
// Maximum handshake message size
static let maxHandshakeMessageSize = 2048 // 2KB to accommodate XX pattern
// Session timeout - sessions older than this should be renegotiated
static let sessionTimeout: TimeInterval = 86400 // 24 hours
// Maximum number of messages before rekey (2^64 - 1 is the nonce limit)
static let maxMessagesPerSession: UInt64 = 1_000_000_000 // 1 billion messages
// Handshake timeout - abandon incomplete handshakes
static let handshakeTimeout: TimeInterval = 60 // 1 minute
// Maximum concurrent sessions per peer
static let maxSessionsPerPeer = 3
// Rate limiting
static let maxHandshakesPerMinute = 10
static let maxMessagesPerSecond = 100
// Global rate limiting (across all peers)
static let maxGlobalHandshakesPerMinute = 30
static let maxGlobalMessagesPerSecond = 500
}
-18
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//
// NoiseSecurityError.swift
// bitchat
//
// This is free and unencumbered software released into the public domain.
// For more information, see <https://unlicense.org>
//
import Foundation
enum NoiseSecurityError: Error {
case sessionExpired
case sessionExhausted
case messageTooLarge
case invalidPeerID
case rateLimitExceeded
case handshakeTimeout
}
@@ -1,22 +0,0 @@
//
// NoiseSecurityValidator.swift
// bitchat
//
// This is free and unencumbered software released into the public domain.
// For more information, see <https://unlicense.org>
//
import Foundation
struct NoiseSecurityValidator {
/// Validate message size
static func validateMessageSize(_ data: Data) -> Bool {
return data.count <= NoiseSecurityConstants.maxMessageSize
}
/// Validate handshake message size
static func validateHandshakeMessageSize(_ data: Data) -> Bool {
return data.count <= NoiseSecurityConstants.maxHandshakeMessageSize
}
}
-230
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//
// NoiseSession.swift
// bitchat
//
// This is free and unencumbered software released into the public domain.
// For more information, see <https://unlicense.org>
//
import BitLogger
import Foundation
import CryptoKit
import BitFoundation
class NoiseSession {
let peerID: PeerID
let role: NoiseRole
private let keychain: KeychainManagerProtocol
private var state: NoiseSessionState = .uninitialized
private var handshakeState: NoiseHandshakeState?
private var sendCipher: NoiseCipherState?
private var receiveCipher: NoiseCipherState?
// Keys
private let localStaticKey: Curve25519.KeyAgreement.PrivateKey
private var remoteStaticPublicKey: Curve25519.KeyAgreement.PublicKey?
// Handshake messages for retransmission
private var sentHandshakeMessages: [Data] = []
private var handshakeHash: Data?
// Thread safety
private let sessionQueue = DispatchQueue(label: "chat.bitchat.noise.session", attributes: .concurrent)
init(
peerID: PeerID,
role: NoiseRole,
keychain: KeychainManagerProtocol,
localStaticKey: Curve25519.KeyAgreement.PrivateKey,
remoteStaticKey: Curve25519.KeyAgreement.PublicKey? = nil
) {
self.peerID = peerID
self.role = role
self.keychain = keychain
self.localStaticKey = localStaticKey
self.remoteStaticPublicKey = remoteStaticKey
}
// MARK: - Handshake
func startHandshake() throws -> Data {
return try sessionQueue.sync(flags: .barrier) {
guard case .uninitialized = state else {
throw NoiseSessionError.invalidState
}
// For XX pattern, we don't need remote static key upfront
handshakeState = NoiseHandshakeState(
role: role,
pattern: .XX,
keychain: keychain,
localStaticKey: localStaticKey,
remoteStaticKey: nil
)
state = .handshaking
// Only initiator writes the first message
if role == .initiator {
let message = try handshakeState!.writeMessage()
sentHandshakeMessages.append(message)
return message
} else {
// Responder doesn't send first message in XX pattern
return Data()
}
}
}
func processHandshakeMessage(_ message: Data) throws -> Data? {
return try sessionQueue.sync(flags: .barrier) {
SecureLogger.debug("NoiseSession[\(peerID)]: Processing handshake message, current state: \(state), role: \(role)")
// Initialize handshake state if needed (for responders)
if state == .uninitialized && role == .responder {
handshakeState = NoiseHandshakeState(
role: role,
pattern: .XX,
keychain: keychain,
localStaticKey: localStaticKey,
remoteStaticKey: nil
)
state = .handshaking
SecureLogger.debug("NoiseSession[\(peerID)]: Initialized handshake state for responder")
}
guard case .handshaking = state, let handshake = handshakeState else {
throw NoiseSessionError.invalidState
}
// Process incoming message
_ = try handshake.readMessage(message)
SecureLogger.debug("NoiseSession[\(peerID)]: Read handshake message, checking if complete")
// Check if handshake is complete
if handshake.isHandshakeComplete() {
// Get transport ciphers and handshake hash (hash captured before split clears state)
let (send, receive, hash) = try handshake.getTransportCiphers(useExtractedNonce: true)
sendCipher = send
receiveCipher = receive
// Store remote static key
remoteStaticPublicKey = handshake.getRemoteStaticPublicKey()
// Store handshake hash for channel binding
handshakeHash = hash
state = .established
handshakeState = nil // Clear handshake state
SecureLogger.debug("NoiseSession[\(peerID)]: Handshake complete (no response needed), transitioning to established")
SecureLogger.info(.handshakeCompleted(peerID: peerID.id))
return nil
} else {
// Generate response
let response = try handshake.writeMessage()
sentHandshakeMessages.append(response)
SecureLogger.debug("NoiseSession[\(peerID)]: Generated handshake response of size \(response.count)")
// Check if handshake is complete after writing
if handshake.isHandshakeComplete() {
// Get transport ciphers and handshake hash (hash captured before split clears state)
let (send, receive, hash) = try handshake.getTransportCiphers(useExtractedNonce: true)
sendCipher = send
receiveCipher = receive
// Store remote static key
remoteStaticPublicKey = handshake.getRemoteStaticPublicKey()
// Store handshake hash for channel binding
handshakeHash = hash
state = .established
handshakeState = nil // Clear handshake state
SecureLogger.debug("NoiseSession[\(peerID)]: Handshake complete after writing response, transitioning to established")
SecureLogger.info(.handshakeCompleted(peerID: peerID.id))
}
return response
}
}
}
// MARK: - Transport
func encrypt(_ plaintext: Data) throws -> Data {
return try sessionQueue.sync(flags: .barrier) {
guard case .established = state, let cipher = sendCipher else {
throw NoiseSessionError.notEstablished
}
return try cipher.encrypt(plaintext: plaintext)
}
}
func decrypt(_ ciphertext: Data) throws -> Data {
return try sessionQueue.sync(flags: .barrier) {
guard case .established = state, let cipher = receiveCipher else {
throw NoiseSessionError.notEstablished
}
return try cipher.decrypt(ciphertext: ciphertext)
}
}
// MARK: - State Management
func getState() -> NoiseSessionState {
return sessionQueue.sync {
return state
}
}
func isEstablished() -> Bool {
return sessionQueue.sync {
if case .established = state {
return true
}
return false
}
}
func getRemoteStaticPublicKey() -> Curve25519.KeyAgreement.PublicKey? {
return sessionQueue.sync {
return remoteStaticPublicKey
}
}
func reset() {
sessionQueue.sync(flags: .barrier) {
let wasEstablished = state == .established
state = .uninitialized
handshakeState = nil
// Clear sensitive cipher states
sendCipher?.clearSensitiveData()
receiveCipher?.clearSensitiveData()
sendCipher = nil
receiveCipher = nil
// Clear sent handshake messages
for i in 0..<sentHandshakeMessages.count {
var message = sentHandshakeMessages[i]
keychain.secureClear(&message)
}
sentHandshakeMessages.removeAll()
// Clear handshake hash
if var hash = handshakeHash {
keychain.secureClear(&hash)
}
handshakeHash = nil
if wasEstablished {
SecureLogger.info(.sessionExpired(peerID: peerID.id))
}
}
}
}
-14
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//
// NoiseSessionError.swift
// bitchat
//
// This is free and unencumbered software released into the public domain.
// For more information, see <https://unlicense.org>
//
enum NoiseSessionError: Error, Equatable {
case invalidState
case notEstablished
case sessionNotFound
case alreadyEstablished
}
-223
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@@ -1,223 +0,0 @@
//
// NoiseSessionManager.swift
// bitchat
//
// This is free and unencumbered software released into the public domain.
// For more information, see <https://unlicense.org>
//
import BitLogger
import CryptoKit
import Foundation
import BitFoundation
final class NoiseSessionManager {
private var sessions: [PeerID: NoiseSession] = [:]
private let localStaticKey: Curve25519.KeyAgreement.PrivateKey
private let keychain: KeychainManagerProtocol
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 onSessionFailed: ((PeerID, Error) -> Void)?
init(localStaticKey: Curve25519.KeyAgreement.PrivateKey, keychain: KeychainManagerProtocol) {
self.localStaticKey = localStaticKey
self.keychain = keychain
self.sessionFactory = { peerID, role in
SecureNoiseSession(
peerID: peerID,
role: role,
keychain: keychain,
localStaticKey: localStaticKey
)
}
}
#if DEBUG
init(
localStaticKey: Curve25519.KeyAgreement.PrivateKey,
keychain: KeychainManagerProtocol,
sessionFactory: @escaping (PeerID, NoiseRole) -> NoiseSession
) {
self.localStaticKey = localStaticKey
self.keychain = keychain
self.sessionFactory = sessionFactory
}
#endif
// MARK: - Session Management
func getSession(for peerID: PeerID) -> NoiseSession? {
return managerQueue.sync {
return sessions[peerID]
}
}
func removeSession(for peerID: PeerID) {
managerQueue.sync(flags: .barrier) {
if let session = sessions.removeValue(forKey: peerID) {
session.reset() // Clear sensitive data before removing
}
}
}
func removeAllSessions() {
managerQueue.sync(flags: .barrier) {
for (_, session) in sessions {
session.reset()
}
sessions.removeAll()
}
}
// MARK: - Handshake Helpers
func initiateHandshake(with peerID: PeerID) throws -> Data {
return try managerQueue.sync(flags: .barrier) {
// Check if we already have an established session
if let existingSession = sessions[peerID], existingSession.isEstablished() {
// Session already established, don't recreate
throw NoiseSessionError.alreadyEstablished
}
// Remove any existing non-established session
if let existingSession = sessions[peerID], !existingSession.isEstablished() {
_ = sessions.removeValue(forKey: peerID)
}
// Create new initiator session
let session = sessionFactory(peerID, .initiator)
sessions[peerID] = session
do {
let handshakeData = try session.startHandshake()
return handshakeData
} catch {
// Clean up failed session
_ = sessions.removeValue(forKey: peerID)
SecureLogger.error(.handshakeFailed(peerID: peerID.id, error: error.localizedDescription))
throw error
}
}
}
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
let session: NoiseSession
if shouldCreateNew {
let newSession = sessionFactory(peerID, .responder)
sessions[peerID] = newSession
session = newSession
} else {
session = existingSession!
}
// Process the handshake message within the synchronized block
do {
let response = try session.processHandshakeMessage(message)
// Check if session is established after processing
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)
}
}
}
return response
} catch {
// Reset the session on handshake failure so next attempt can start fresh
_ = sessions.removeValue(forKey: peerID)
// Schedule callback outside the synchronized block to prevent deadlock
DispatchQueue.global().async { [weak self] in
self?.onSessionFailed?(peerID, error)
}
SecureLogger.error(.handshakeFailed(peerID: peerID.id, error: error.localizedDescription))
throw error
}
}
}
// MARK: - Encryption/Decryption
func encrypt(_ plaintext: Data, for peerID: PeerID) throws -> Data {
guard let session = getSession(for: peerID) else {
throw NoiseSessionError.sessionNotFound
}
return try session.encrypt(plaintext)
}
func decrypt(_ ciphertext: Data, from peerID: PeerID) throws -> Data {
guard let session = getSession(for: peerID) else {
throw NoiseSessionError.sessionNotFound
}
return try session.decrypt(ciphertext)
}
// MARK: - Key Management
func getRemoteStaticKey(for peerID: PeerID) -> Curve25519.KeyAgreement.PublicKey? {
return getSession(for: peerID)?.getRemoteStaticPublicKey()
}
// MARK: - Session Rekeying
func getSessionsNeedingRekey() -> [(peerID: PeerID, needsRekey: Bool)] {
return managerQueue.sync {
var needingRekey: [(peerID: PeerID, needsRekey: Bool)] = []
for (peerID, session) in sessions {
if let secureSession = session as? SecureNoiseSession,
secureSession.isEstablished(),
secureSession.needsRenegotiation() {
needingRekey.append((peerID: peerID, needsRekey: true))
}
}
return needingRekey
}
}
func initiateRekey(for peerID: PeerID) throws {
// Remove old session
removeSession(for: peerID)
// Initiate new handshake
_ = try initiateHandshake(with: peerID)
}
}
-13
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//
// NoiseSessionState.swift
// bitchat
//
// This is free and unencumbered software released into the public domain.
// For more information, see <https://unlicense.org>
//
enum NoiseSessionState: Equatable {
case uninitialized
case handshaking
case established
}
-85
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@@ -1,85 +0,0 @@
//
// SecureNoiseSession.swift
// bitchat
//
// This is free and unencumbered software released into the public domain.
// For more information, see <https://unlicense.org>
//
import Foundation
final class SecureNoiseSession: NoiseSession {
private(set) var messageCount: UInt64 = 0
private var sessionStartTime = Date()
private(set) var lastActivityTime = Date()
override func encrypt(_ plaintext: Data) throws -> Data {
// Check session age
if Date().timeIntervalSince(sessionStartTime) > NoiseSecurityConstants.sessionTimeout {
throw NoiseSecurityError.sessionExpired
}
// Check message count
if messageCount >= NoiseSecurityConstants.maxMessagesPerSession {
throw NoiseSecurityError.sessionExhausted
}
// Validate message size
guard NoiseSecurityValidator.validateMessageSize(plaintext) else {
throw NoiseSecurityError.messageTooLarge
}
let encrypted = try super.encrypt(plaintext)
messageCount += 1
lastActivityTime = Date()
return encrypted
}
override func decrypt(_ ciphertext: Data) throws -> Data {
// Check session age
if Date().timeIntervalSince(sessionStartTime) > NoiseSecurityConstants.sessionTimeout {
throw NoiseSecurityError.sessionExpired
}
// Validate message size
guard NoiseSecurityValidator.validateMessageSize(ciphertext) else {
throw NoiseSecurityError.messageTooLarge
}
let decrypted = try super.decrypt(ciphertext)
lastActivityTime = Date()
return decrypted
}
func needsRenegotiation() -> Bool {
// Check if we've used more than 90% of message limit
let messageThreshold = UInt64(Double(NoiseSecurityConstants.maxMessagesPerSession) * 0.9)
if messageCount >= messageThreshold {
return true
}
// Check if last activity was more than 30 minutes ago
if Date().timeIntervalSince(lastActivityTime) > NoiseSecurityConstants.sessionTimeout {
return true
}
return false
}
// MARK: - Testing Support
#if DEBUG
func setLastActivityTimeForTesting(_ date: Date) {
lastActivityTime = date
}
func setMessageCountForTesting(_ count: UInt64) {
messageCount = count
}
func setSessionStartTimeForTesting(_ date: Date) {
sessionStartTime = date
}
#endif
}
+2 -1
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@@ -7,6 +7,7 @@
//
import BitLogger
import protocol Noise.SecureMemoryCleaner
import Foundation
import Security
@@ -51,7 +52,7 @@ enum KeychainSaveResult {
}
}
protocol KeychainManagerProtocol {
protocol KeychainManagerProtocol: SecureMemoryCleaner {
func saveIdentityKey(_ keyData: Data, forKey key: String) -> Bool
func getIdentityKey(forKey key: String) -> Data?
func deleteIdentityKey(forKey key: String) -> Bool
@@ -84,6 +84,7 @@
import BitLogger
import BitFoundation
import Noise
import Foundation
import CryptoKit