Security System

Overview

The GC2 Networking Security System provides comprehensive server-authoritative protection for all Game Creator 2 networking modules. It includes:

• Rate Limiting: Prevents request spam from clients

• Sequence Validation: Detects replay attacks

• State Validation: Detects state desynchronization and cheating

• Violation Tracking: Logs, warns, blocks, or kicks malicious clients

• Optional Source Patches: Deep integration for maximum security

Architecture

┌─────────────────────────────────────────────────────────────────┐
│                    NetworkSecurityManager                        │
│  ┌──────────────┐ ┌──────────────┐ ┌──────────────┐             │
│  │ Rate Limiter │ │  Violation   │ │   Sequence   │             │
│  │  (per module)│ │   Tracker    │ │   Tracker    │             │
│  └──────────────┘ └──────────────┘ └──────────────┘             │
└─────────────────────────────────────────────────────────────────┘
                              │
                              ▼
┌─────────────────────────────────────────────────────────────────┐
│                   SecurityIntegration                            │
│  ┌──────────────┐ ┌──────────────┐ ┌──────────────┐             │
│  │ValidateCore()│ │ValidateStats │ │ValidateMelee │             │
│  │ValidateShooter│ │ValidateInventory│ │ValidateAbilities │       │
│  └──────────────┘ └──────────────┘ └──────────────┘             │
└─────────────────────────────────────────────────────────────────┘
                              │
                              ▼
┌─────────────────────────────────────────────────────────────────┐
│                   Network Controllers                            │
│  NetworkStatsController | NetworkInventoryController | etc.     │
└─────────────────────────────────────────────────────────────────┘

Quick Start

1. Add NetworkSecurityManager to Scene

// Add to your NetworkManager or a persistent object
[RequireComponent(typeof(NetworkSecurityManager))]
public class MyNetworkManager : MonoBehaviour
{
    private void Start()
    {
        var security = GetComponent<NetworkSecurityManager>();
        
        // Initialize on server
        security.Initialize(
            isServer: true, 
            getServerTime: () => Time.time
        );
        
        // Set up kick handler
        security.KickClient = (clientId, reason) =>
        {
            // Your transport adapter's disconnect/kick implementation
            MyNetworkTransport.KickClient(clientId, reason);
        };
    }
}

2. Configure Security Settings

In the Inspector on NetworkSecurityManager:

Setting	Default	Description
Enable Rate Limiting	true	Limit requests per second
Max Requests Per Second	20	Per-module request limit
Enable Anomaly Detection	true	Track violation patterns
Violation Threshold	5	Violations before action
Violation Action	TempBlock	LogOnly/LogAndWarn/TempBlock/Kick
Temp Block Duration	30s	Block duration for TempBlock
Enable State Validation	true	Periodic state checks

3. Integrate with Controllers

// In your server-side request processor:
public NetworkStatModifyResponse ProcessStatModifyRequest(
    NetworkStatModifyRequest request, 
    uint clientNetworkId)
{
    // Validate using SecurityIntegration
    uint correlationId = NetworkCorrelation.Compose(request.ActorNetworkId, request.RequestId);
    if (!SecurityIntegration.ValidateStatsRequest(
        clientNetworkId, 
        request.ActorNetworkId,
        correlationId,
        "StatModify",
        request.StatHash, 
        request.Value))
    {
        return new NetworkStatModifyResponse
        {
            RequestId = request.RequestId,
            Authorized = false,
            RejectionReason = StatRejectionReason.SecurityViolation
        };
    }
    
    // Continue with normal processing...
}

Optional Source Patches

For maximum security, you can patch GC2 source files to add deep network validation hooks. This prevents clients from bypassing network validation by calling GC2 methods directly.

Patch Menu

Access via: Game Creator > Networking Layer > Patches

Module	What Gets Patched
Abilities	Caster.Cast(), Learn(), UnLearn()
Stats	RuntimeStatData.Base, AddModifier(), RemoveModifier()
	RuntimeAttributeData.Value
Inventory	TBagContent.Use(), Drop()
	BagWealth.Set(), Add()
Melee	MeleeStance.InputCharge/Execute(), PlaySkill(), Hit()
	Skill.OnHit()
Shooter	ShooterStance.PullTrigger(), ReleaseTrigger(), Reload()
	WeaponData.Shoot()

How to Apply Patches

1. Go to Game Creator > Networking Layer > Patches > [Module] > Patch

2. Review the dialog explaining changes

3. Click "Apply Patch"

4. Backups are created automatically

How to Remove Patches

1. Go to Game Creator > Networking Layer > Patches > [Module] > Unpatch

2. Original files are restored from backup

Check Patch Status

• Single module: Game Creator > Networking Layer > Patches > [Module] > Check Status

• All modules: Game Creator > Networking Layer > Patches > Status Overview...

Security Violation Types

Type	Description
RateLimitExceeded	Client sending too many requests
InvalidSequence	Out-of-order or duplicate request IDs (replay attack)
ReplayAttack	Request ID already processed
OutOfBoundsValue	Value outside acceptable range
StateDesync	Client state doesn't match server
UnauthorizedAction	Action not permitted for client
InvalidTarget	Targeting entity client shouldn't access

Violation Actions

Configure in NetworkSecurityConfig:

Action	Behavior
LogOnly	Log to console only
LogAndWarn	Log + send warning to client
TempBlock	Temporarily block client requests
Kick	Disconnect client from server
Custom	Call your custom handler

Module-Specific Configuration

You can configure different security settings per module:

var security = NetworkSecurityManager.Instance;

// Get config for specific module
var statsConfig = security.GetConfigForModule("Stats");
statsConfig.MaxRequestsPerSecond = 30; // Stats need more requests

var combatConfig = security.GetConfigForModule("Melee");
combatConfig.ViolationThreshold = 3; // Combat is stricter

Enable module overrides in Inspector by checking "Use Module Overrides".

State Validators

State validators periodically compare client-reported state with server-authoritative state:

// Example: Stats state validation
public struct StatsState : IEquatable<StatsState>
{
    public Dictionary<int, float> StatValues;
    public Dictionary<int, float> AttributeValues;
    public HashSet<int> ActiveStatusEffects;
}

Configure validation interval and discrepancy threshold per module.

Events

Subscribe to security events for custom handling:

var security = NetworkSecurityManager.Instance;

security.OnViolationDetected += (violation) =>
{
    Debug.Log($"Violation: {violation.ViolationType} from client {violation.ClientId}");
};

security.OnThresholdExceeded += (clientId, violationType) =>
{
    Debug.LogWarning($"Client {clientId} exceeded threshold for {violationType}");
};

security.OnClientBlocked += (clientId, duration) =>
{
    Debug.LogWarning($"Client {clientId} blocked for {duration} seconds");
};

Best Practices

1. Always validate on server: Never trust client data

2. Use rate limiting: Prevent request flooding

3. Enable state validation: Catch desync early

4. Apply patches for competitive games: Maximum security

5. Test thoroughly: Security can cause false positives

6. Log violations: Track potential exploits

7. Tune thresholds: Balance security vs. false positives

Troubleshooting

"Rate limited" errors for legitimate players

• Increase MaxRequestsPerSecond for the module

• Increase RateLimitWindow for burst tolerance

False positive state desync

• Increase ValidationInterval

• Increase MaxDiscrepancies threshold

• Check for high network latency

Patches fail to apply

• GC2 source may have been updated

• Check console for specific error

• Create GitHub issue with GC2 version

File Locations

File	Purpose
Security/NetworkSecurityTypes.cs	Config, enums, helpers
Security/NetworkSecurityManager.cs	Central manager singleton
Security/StateValidators.cs	State validation classes
Security/SecurityIntegration.cs	Controller integration helpers
Patches/GC2PatcherBase.cs	Abstract patcher base
Patches/GC2PatchManager.cs	Menu items & status window
Patches/[Module]Patcher.cs	Module-specific patchers
Library/GameCreator2NetworkingLayer/Patches/Backups/[Module]/	Auto-generated backup files

Version Compatibility

• Unity: 6 LTS

• Game Creator 2: 2.18.6+

• DaimahouGames Abilities: 2.0+

Support

For issues or questions, please open a GitHub issue with:

• Unity version

• GC2 module versions

• Console error logs

• Steps to reproduce