🚀 SecureWebSocketClient-Cpp

A Native C++17 Secure WebSocket Client (Winsock + OpenSSL)

A lightweight, high-performance WebSocket client built from scratch, implementing the full WebSocket RFC 6455 handshake, framing logic, masking, and TLS encryption — without using any external WebSocket libraries.

This client connects to secure WSS servers, performs the HTTP Upgrade handshake, encrypts packets using OpenSSL, and handles full-duplex messaging.

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⭐ Why This Project Stands Out

🔹 Fully Native WebSocket Stack

Implements the protocol manually:

• HTTP Upgrade → 101 Switching Protocols
• Base64 nonce generation
• Frame masking/unmasking
• Bit-level frame construction
• Opcode handling

🔹 Secure by Design

Uses OpenSSL for TLS handshaking and encrypted communication.

🔹 Windows-Native

Built using:

• Winsock2
• CMake
• MSVC (Visual Studio)
• vcpkg for dependency management

🔹 Clean, Modular Codebase

Separated into:

• websocket_client.*
• tls_context.*
• cli.*
• tests/

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🧩 Features

Feature	Description
✔️ Secure WSS support	Encrypted WebSocket over TLS
✔️ Manual frame construction	FIN, Opcode, Payload Length, Masking
✔️ True full-duplex	Separate listening + sending threads
✔️ Native sockets	No Boost or external WebSocket libs
✔️ Unit tests	Simple connection and echo tests
✔️ Clean CLI	/exit, message input, and error reporting

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🛠️ Tech Stack

• C++17
• Windows API (Winsock2)
• OpenSSL (via vcpkg)
• CMake Build System
• MSVC Toolchain

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📦 Installation & Build Guide

1️⃣ Install Dependencies

vcpkg install openssl:x64-windows

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2️⃣ Configure the Project

mkdir build
cmake -S . -B build -DCMAKE_TOOLCHAIN_FILE=C:/Users/ershe/vcpkg/scripts/buildsystems/vcpkg.cmake -A x64

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3️⃣ Build

cmake --build build --config Release

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4️⃣ Run

./build/Release/websocket_client.exe

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🧠 Core Concepts Learned

🔸 WebSocket Protocol (RFC 6455)

• HTTP Upgrade handshake
• Sec-WebSocket-Key + Base64
• Accept hash using SHA-1
• Opcode handling

🔸 Secure Networking

• TLS handshake
• Certificate validation
• OpenSSL BIO socket integration

🔸 Windows Systems Programming

• Winsock socket creation
• Address resolution
• TCP stream communication

🔸 Low-Level Bit Manipulation

• ASN.1 compliant masking
• Payload segmentation
• Frame packing/unpacking

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🧪 Testing

Inside tests/:

• Automated connect / send / receive test
• Asserts handshake success
• Tests echo server consistency

Run manually:

./build/Release/websocket_tests.exe

📁 Project Structure

SecureWebSocketClient-Cpp
│   CMakeLists.txt
│   LICENSE
│
├── src
│   ├── main.cpp
│   ├── cli/
│   │     cli.h
│   │     cli.cpp
│   └── websocket/
│         websocket_client.h
│         websocket_client.cpp
│         tls_context.h
│         tls_context.cpp
│
└── tests/
      websocket_client_test.cpp

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📜 License

This project is licensed under the MIT License.

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✨ Created By

Shehzan Khan