RemoteDesk 🖥️

A remote desktop system that lets you view and control a Windows PC through a browser — similar to TeamViewer.

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Overview

The system consists of 3 components:

[Windows Client App]  ←──SignalR──→  [ASP.NET Core Server]  ←──SignalR──→  [Browser]
  Screen Capture                        JWT Auth + Relay                   Live View +
  Mouse/Keyboard                        WebSockets                         Control

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Requirements

• .NET 8 SDK or higher
• Windows (for the client — requires Screen Capture & P/Invoke)
• A modern browser (Chrome, Firefox, Edge)

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Getting Started

1. Trust the HTTPS certificate (one-time)

dotnet dev-certs https --trust

2. Start the Server

cd Server
dotnet run

Server runs on:

• https://localhost:7001
• http://localhost:5000

3. Start the Client

cd Client
dotnet run

The Windows Forms window will open.

4. Connect

In the Client window:

1. Server URL: https://localhost:7001
2. PC Name: auto-filled with your machine name
3. Click Connect → status turns green

In the Browser:

1. Open https://localhost:7001
2. Login: admin / admin123
3. Click your PC in the sidebar → live stream starts
4. Use your mouse and keyboard directly in the browser

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Project Structure

RemoteDesk/
├── Client/                          # Windows Forms application
│   ├── Form1.cs                     # Core logic (capture, input, SignalR)
│   ├── Form1.Designer.cs            # UI layout
│   ├── Program.cs                   # Entry point
│   ├── Properties/
│   │   └── Settings.cs              # JSON-based persistent settings
│   └── RemoteDesk.Client.csproj
│
└── Server/                          # ASP.NET Core web server
    ├── Controllers/
    │   └── AuthController.cs        # POST /api/auth/login → JWT token
    ├── Hubs/
    │   └── RemoteHub.cs             # SignalR hub (core relay logic)
    ├── Models/
    │   └── Models.cs                # LoginRequest, PcInfo
    ├── Services/
    │   └── PcRegistryService.cs     # In-memory registry of connected PCs
    ├── wwwroot/
    │   ├── index.html               # Web UI (single page app)
    │   ├── css/style.css            # Dark theme design
    │   └── js/app.js                # SignalR client + rendering + input
    ├── Program.cs                   # Server configuration
    ├── appsettings.json             # JWT, ports, logging
    └── RemoteDesk.Server.csproj

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Features

Feature	Description
🖥️ Screen Streaming	JPEG frames transmitted via SignalR WebSocket
🖱️ Mouse Control	Move, click, right-click, double-click, scroll
⌨️ Keyboard Control	Full keyboard pass-through incl. F-keys and special keys
🔐 JWT Authentication	Token-based login, valid for 8 hours
🔄 Auto-Reconnect	Client and browser reconnect automatically on disconnect
📊 FPS Counter	Live frames-per-second display in the toolbar
🔔 System Tray	Client minimizes to the system tray and runs in the background
⛶ Fullscreen	Browser fullscreen mode for immersive control
💻 Multiple PCs	Multiple PCs can be registered and switched between

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Configuration

Managing Users

In Server/Controllers/AuthController.cs:

private static readonly Dictionary<string, string> _users = new()
{
    ["admin"] = "admin123",
    ["alice"] = "mypassword"
};

Changing the JWT Secret

In Server/appsettings.json — must be changed before deploying!

"Jwt": {
  "Key": "REPLACE_WITH_A_LONG_RANDOM_SECRET_MIN_32_CHARS",
  "Issuer": "RemoteDesktopServer",
  "Audience": "RemoteDesktopClients"
}

Performance Tuning

Adjust in the Client window:

Setting	Recommended	Description
JPEG Quality	50–70	Lower = faster, less quality
Interval (ms)	66 ms	≈ 15 FPS (smooth)
Interval (ms)	100 ms	≈ 10 FPS (lighter load)

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SignalR Hub Methods

PC → Server

Method	Description
RegisterPc(pcId)	PC agent registers itself on connect
SendFrame(pcId, base64)	Streams a JPEG screen frame

Browser → Server

Method	Description
WatchPc(pcId)	Browser starts watching a PC
StopWatching(pcId)	Browser stops the session
SendMouseEvent(pcId, x, y, type)	Forward a mouse event
SendKeyboardEvent(pcId, key, isDown)	Forward a key press
GetOnlinePcs()	Get list of all connected PCs

Server → Browser

Event	Description
ReceiveFrame(base64)	New screen frame arrived
PcOnline(pcId)	A PC came online
PcOffline(pcId)	A PC disconnected

Server → PC

Event	Description
StartStream	Begin sending frames
StopStream	Pause sending frames
MouseEvent(x, y, type)	Execute mouse action
KeyboardEvent(key, isDown)	Execute key press

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Security Notes

⚠️ This project is intended as a development / learning project.

For production use, consider:

• Replace the JWT secret with a strong, random value
• Store users in a database (e.g. ASP.NET Core Identity)
• Restrict CORS to known domains only
• Use HTTPS with a real certificate (e.g. Let's Encrypt)
• Add two-factor authentication
• Implement IP allowlisting

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Tech Stack

Layer	Technology
Windows Client	C# .NET 8, Windows Forms, SignalR Client
Web Server	ASP.NET Core 8, SignalR, JWT Bearer Auth
Web Frontend	HTML, CSS, Vanilla JavaScript, SignalR JS
Communication	WebSockets (SignalR)
Screen Capture	System.Drawing, GDI+
Input Simulation	user32.dll P/Invoke