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