https://github.com/marichu-kt/chacha20-poly1305-x25519
Esto es una app cliente-servidor en C++ que cifra mensajes con ChaCha20-Poly1305 y usa X25519 para el intercambio seguro de claves. Soporta comunicación bidireccional por TCP y configuración vía XML.
https://github.com/marichu-kt/chacha20-poly1305-x25519
asymmetric-encryption c-plus-plus chacha20-poly1305 client-server cpp cryptography curve25519 end-to-end-encryption multi-threading network-security openssl secure-chat secure-communication secure-messaging tcp-sockets x25519 xml-configuration
Last synced: about 1 month ago
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Esto es una app cliente-servidor en C++ que cifra mensajes con ChaCha20-Poly1305 y usa X25519 para el intercambio seguro de claves. Soporta comunicación bidireccional por TCP y configuración vía XML.
- Host: GitHub
- URL: https://github.com/marichu-kt/chacha20-poly1305-x25519
- Owner: marichu-kt
- License: other
- Created: 2025-04-02T20:50:41.000Z (about 2 months ago)
- Default Branch: main
- Last Pushed: 2025-04-16T14:13:42.000Z (about 1 month ago)
- Last Synced: 2025-04-16T20:42:41.873Z (about 1 month ago)
- Topics: asymmetric-encryption, c-plus-plus, chacha20-poly1305, client-server, cpp, cryptography, curve25519, end-to-end-encryption, multi-threading, network-security, openssl, secure-chat, secure-communication, secure-messaging, tcp-sockets, x25519, xml-configuration
- Language: C++
- Homepage:
- Size: 398 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Secure Communication System with ChaCha20-Poly1305 and X25519
## 🔐 Project Overview
This project implements a secure, multi-client communication system in C++ using modern cryptographic algorithms: **ChaCha20-Poly1305** for authenticated encryption and **X25519** for secure key exchange. It allows simultaneous connections from multiple clients to a central server, enabling encrypted real-time messaging and file transfer with built-in logging and full control from the server side.
> Designed as a robust, modular, and real-world secure communication platform.
---
## ✨ Key Features
- ✅ **End-to-end encryption** using ChaCha20-Poly1305 (AEAD).
- ✅ **Ephemeral session keys** via X25519 ECDH key exchange.
- ✅ **Multiclient support** with unique session per client.
- ✅ **Encrypted file transfer** including metadata (name, size).
- ✅ **Binary communication protocol** (type + length + data).
- ✅ **XML-based configuration** for IP/PORT.
- ✅ **Custom command interface** for both client and server.
- ✅ **Logging system** for all communications.
- ✅ **Safe packet reconstruction** before decryption.
---
## 🌐 System Architecture
```
+------------+ +-------------+
| Client 1 | <--+ +->| Server |<--+--> Client N
+------------+ | | +-------------+ |
| ChaCha20 |<---+ +--| X25519 | +-> Logger
+------------+ +-------------+
```
- Each client initiates connection and performs **ECDH** handshake.
- A unique **symmetric session key** is derived.
- All communication is **encrypted + authenticated** using ChaCha20-Poly1305.
- Server handles multiple clients concurrently with threading.
---
## 📂 Project Structure
```mermaid
graph LR
A[ChaCha20-Poly1305-X25519/] --> A1[README.md]
A --> A2[LICENSE]
A --> A3[client.cpp]
A --> A4[server.cpp]
A --> A5[common_crypto.h]
A --> A6[logger.h]
A --> A7[tinyxml2.cpp/.h]
A --> B[logs/]
B --> B1[communications_history.log]
A --> C[bin/]
C --> C1[client.exe]
C --> C2[server.exe]
A --> D[public/]
D --> D1[COMPILATION.md]
A --> E[received_files/]
A --> F[src/]
F --> F1[client.bat]
F --> F2[server.bat]
F --> F3[client.xml]
F --> F4[server.xml]
```
---
## ⚖️ Requirements
- **C++17** or higher
- **OpenSSL** (1.1.1+)
- **TinyXML2**
- **g++ (MinGW-w64)** for Windows
---
## ⚙️ Compilation (Windows with g++)
```bash
g++ client.cpp tinyxml2.cpp -lws2_32 -lssl -lcrypto -o bin/client.exe
g++ server.cpp tinyxml2.cpp -lws2_32 -lssl -lcrypto -o bin/server.exe
```
Ensure that the DLLs from OpenSSL are accessible at runtime (`libssl`, `libcrypto`).
---
## 🚀 Execution
Use the `.bat` scripts to run:
```bash
src/client.bat
src/server.bat
```
They load config from:
- `client.xml` for the client
- `server.xml` for the server
Each file contains:
```xml
127.0.0.1
40000
```
---
## 🔐 Cryptography in Detail
- **X25519**: Each connection uses ephemeral keys to derive a shared session key securely.
- **ChaCha20-Poly1305**:
- 256-bit key
- 96-bit nonce
- 128-bit authentication tag
- Nonces and keys are generated using secure RNG (OpenSSL).
---
## ✉️ Binary Protocol
Every message is sent in this format:
```
[ 4 bytes length ] [ 1 byte type ] [ encrypted content ] [ 16 bytes tag ]
```
- Types:
- `0x01` Text message
- `0xAA` Encrypted file with metadata
- `0x04` Broadcast message
- `0xFF` Exit / shutdown
---
## 📄 File Transfer & Metadata
- Command: `file `
- Payload structure (encrypted):
```
[4 bytes client ID][4 bytes name_len][filename][8 bytes size][file_data]
```
- Files are saved on the server in `received_files/`
- All parts (name, size, content) are encrypted.
---
## 🔄 Communication Flow
1. Client connects and receives server public key
2. Client sends its public key
3. Server derives shared key and sends nonce
4. Communication begins: encrypted messages/files
5. Messages are reconstructed based on length before decryption
---
## 🔐 Client Selection & Multiuser Control
- Each client gets a unique 4-digit ID
- Server operator can:
- List connected clients: `list`
- Send private messages: `send `
- Broadcast to all: `broadcast `
---
## 🔑 Key & Session Management
- Keys are **ephemeral** and regenerated on every connection
- No key is stored on disk
- Each session is uniquely encrypted
---
## ✅ Security Best Practices
- AEAD cipher ensures **confidentiality + authenticity**
- No plaintext metadata transmitted
- Per-client encryption avoids shared state
- Secure random generation for all nonces and keypairs
- Logs never store plaintext content
---
## 📃 Example Output
```bash
mario@server:~$ list
[*] Connected clients:
ID: 1032
ID: 4821
mario@server:~$ send 1032 Hola, cliente 1032
[>] Message sent to Client 1032
mario@client[1032]:~$ file C:/Users/user/Desktop/test.pdf
[*] Archivo enviado: test.pdf (14358 bytes)
```
---
## 📋 Example Log File
Logs are automatically stored with timestamp, source, and message. Sample:
```log
[2025-04-16 00:01:01.646] [Servidor 1842] Cliente conectado
[2025-04-16 00:01:08.984] [Servidor 7935] Cliente conectado
[2025-04-16 00:01:12.122] [Servidor 6263] Cliente conectado
[2025-04-16 00:03:20.371] [Broadcast 6263] Hola a todos los clientes
[2025-04-16 00:03:20.371] [Broadcast 7935] Hola a todos los clientes
[2025-04-16 00:03:20.371] [Broadcast 1842] Hola a todos los clientes
[2025-04-16 00:03:20.372] [Servidor -1] Broadcast: Hola a todos los clientes
[2025-04-16 00:03:45.434] [Servidor 7935] Hola cliente individual
[2025-04-16 00:04:11.820] [Cliente 1842] Hola Servidor, soy un Cliente
[2025-04-16 00:04:46.816] [Cliente 6263] Oye Servidor, te voy a enviar un NFT
[2025-04-16 00:05:42.763] [Cliente 6263] Archivo recibido: NFT_V5.jpg (72523 bytes)
[2025-04-16 00:06:09.480] [Servidor 6263] Recibido el NFT, muchas gracias
[2025-04-16 00:06:17.591] [Cliente 7935] Adios
[2025-04-16 00:06:20.620] [Servidor 7935] Cliente desconectado
[2025-04-16 00:06:35.365] [Cliente 6263] Tengo que irme
[2025-04-16 00:06:37.895] [Servidor 6263] Cliente desconectado
[2025-04-16 00:07:00.628] [Servidor -1] Server terminated via 'exit' command.
```
📄 Full log file available here: [communications_history.log](https://github.com/marichu-kt/ChaCha20-Poly1305-X25519/blob/main/logs/communications_history.log)
---
## 🌍 License
This project is licensed under a custom educational license.
See the full license here: [LICENSE](https://github.com/marichu-kt/ChaCha20-Poly1305-X25519/blob/main/LICENSE)
---
## 📄 Credits
Developed by [@marichu_kt](https://github.com/marichu-kt)
Official Repository: [ChaCha20-Poly1305-X25519](https://github.com/marichu-kt/ChaCha20-Poly1305-X25519)