CTF_MCP_Server

CTF MCP Server is a multi-function cryptography tool server designed to assist participants in CTF challenges. It exposes a set of cryptographic and analysis tools that you can invoke remotely via the MCP protocol, including aes_decrypt for various AES modes, base64 encoding/decoding, caesar cipher shifts, basic calculate operations, frequency_analysis for text patterns, rsa_factor_n for factoring tasks, vigenere_decrypt for breaking Vigenère ciphers, and xor_cipher for XOR-based operations. To use it, start the server with the provided executable and connect a MCP client to the server according to your environment. Once connected, you can send requests specifying the desired tool (e.g., aes_decrypt, base64, caesar) along with the input data and any parameters the tool requires, and receive the computed result in response.

Typical usage flow:

• Start the server using the configured binary and ensure it is reachable by your MCP client.
• In your MCP client, choose the function you want to run (e.g., base64, caesar, or vigenere_decrypt) and supply the input data plus any needed parameters (like shift for caesar or key for vigenere).
• Submit the request and process the returned result in your challenge workflow. The server is designed to be a drop-in cryptography toolkit for rapid challenge solving and verification.

Prerequisites:

• A compatible operating system (the server binary shown is a Windows executable; ensure you can run Windows executables).
• Access to the CTF MCP Server binary (ctf_mcp_server.exe) and its directory permissions.

Installation steps:

1. Obtain the server binary:
   • Download or clone the repository that contains ctf_mcp_server.exe and the accompanying files.
2. Prepare the runtime environment:
   • Ensure the executable has permissions to run on your system.
   • Confirm that the network/port settings (as required by your MCP client) are available and not blocked by a firewall.
3. Configure the MCP server (example):
   • Create or modify your MCP configuration to reference the server binary path and any environment variables. An example configuration snippet is provided in the repository: { "ctf_mcp_server": { "command": "D:/MCPServer/ctf_mcp_server.exe", "args": [], "env": {} } }
4. Start the server:
   • Run the executable directly or use your MCP framework to launch it with the configured settings.
5. Connect a MCP client:
   • Use your preferred MCP client to connect to the server and begin issuing tool requests (aes_decrypt, base64, caesar, etc.).

Tips and caveats:

• The server is exposed as a Windows executable in the example configuration; if you move the binary, ensure the path in the config is updated accordingly.
• The env field in the configuration is optional; you can add environment variables as needed by your deployment, e.g., {"ENV_VAR": "value"}.
• If you encounter issues starting the server, verify file permissions, correct path names (watch for spaces or non-ASCII characters), and that the MCP client and server can reach each other over the intended network port.
• When testing tools, sanitize and validate inputs to avoid unintended behavior and to ensure deterministic results during challenges.