Raise Noise coverage to 99 percent (#1057)

Co-authored-by: jack <jackjackbits@users.noreply.github.com>

bitchat/Noise/NoiseProtocol.swift

@@ -384,6 +384,16 @@ final class NoiseCipherState {
             replayWindow[i] = 0
         }
     }
+
+    #if DEBUG
+    func setNonceForTesting(_ nonce: UInt64) {
+        self.nonce = nonce
+    }
+
+    func extractNonceFromCiphertextPayloadForTesting(_ combinedPayload: Data) throws -> (nonce: UInt64, ciphertext: Data)? {
+        try extractNonceFromCiphertextPayload(combinedPayload)
+    }
+    #endif
 }
 
 // MARK: - Symmetric State
@@ -585,8 +595,9 @@ final class NoiseHandshakeState {
             break // No pre-message keys
         case .IK, .NK:
             if role == .initiator, let remoteStatic = remoteStaticPublic {
-                _ = symmetricState.getHandshakeHash()
                 symmetricState.mixHash(remoteStatic.rawRepresentation)
+            } else if role == .responder, let localStatic = localStaticPublic {
+                symmetricState.mixHash(localStatic.rawRepresentation)
             }
         }
     }
@@ -861,6 +872,20 @@ final class NoiseHandshakeState {
     func getHandshakeHash() -> Data {
         return symmetricState.getHandshakeHash()
     }
+
+    #if DEBUG
+    func performDHOperationForTesting(_ pattern: NoiseMessagePattern) throws {
+        try performDHOperation(pattern)
+    }
+
+    func setCurrentPatternForTesting(_ currentPattern: Int) {
+        self.currentPattern = currentPattern
+    }
+
+    func setRemoteEphemeralPublicKeyForTesting(_ key: Curve25519.KeyAgreement.PublicKey?) {
+        self.remoteEphemeralPublic = key
+    }
+    #endif
 }
 
 // MARK: - Pattern Extensions

bitchat/Noise/NoiseSessionManager.swift

@@ -14,6 +14,7 @@ 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
@@ -23,7 +24,27 @@ final class NoiseSessionManager {
     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
     
@@ -66,12 +87,7 @@ final class NoiseSessionManager {
             }
             
             // Create new initiator session
-            let session = SecureNoiseSession(
-                peerID: peerID,
-                role: .initiator,
-                keychain: keychain,
-                localStaticKey: localStaticKey
-            )
+            let session = sessionFactory(peerID, .initiator)
             sessions[peerID] = session
             
             do {
@@ -117,12 +133,7 @@ final class NoiseSessionManager {
             // Get or create session
             let session: NoiseSession
             if shouldCreateNew {
-                let newSession = SecureNoiseSession(
-                    peerID: peerID,
-                    role: .responder,
-                    keychain: keychain,
-                    localStaticKey: localStaticKey
-                )
+                let newSession = sessionFactory(peerID, .responder)
                 sessions[peerID] = newSession
                 session = newSession
             } else {

bitchat/Noise/SecureNoiseSession.swift

@@ -10,7 +10,7 @@ import Foundation
 
 final class SecureNoiseSession: NoiseSession {
     private(set) var messageCount: UInt64 = 0
-    private let sessionStartTime = Date()
+    private var sessionStartTime = Date()
     private(set) var lastActivityTime = Date()
     
     override func encrypt(_ plaintext: Data) throws -> Data {
@@ -77,5 +77,9 @@ final class SecureNoiseSession: NoiseSession {
     func setMessageCountForTesting(_ count: UInt64) {
         messageCount = count
     }
+
+    func setSessionStartTimeForTesting(_ date: Date) {
+        sessionStartTime = date
+    }
     #endif
 }