A simple SSH tunneling application written in Go.

• Configuration via JSON file
• SSH authentication with username/password or private key
• Source and destination port configuration for tunneling
• No interactive shell access
• Optional configuration encryption

1. Make sure you have Go installed (version 1.21 or later)
2. Clone this repository
3. Run go build to build the application

./tunnel.exe -config config.json

The application uses a JSON configuration file with the following structure:

{
  "ssh": {
    "host": "example.com",
    "port": 22,
    "username": "user",
    "password": "password",
    "private_key": ""
  },
  "tunnel": {
    "source_port": 8080,
    "destination_port": 3306
  },
  "encrypted": false
}

• host: The SSH server hostname or IP address
• port: The SSH server port (usually 22)
• username: SSH username
• password: SSH password (optional if using private key)
• private_key: SSH private key file path or private key content (optional if using password)

If you specify a file path for private_key (e.g., "./id_rsa"), the application will read the private key from that file. If you specify the actual private key content (e.g., "-----BEGIN RSA PRIVATE KEY-----..."), the application will use it directly.

• source_port: The local port to listen on
• destination_port: The remote port to connect to

• encrypted: Whether the configuration file is encrypted

To create an encrypted configuration file, set encrypted to true in the configuration and use the saveConfig function to save it.

Note: The current implementation uses a fixed encryption key for simplicity. In a production environment, you should use a more secure method for managing encryption keys.

To tunnel localhost:8080 to a remote MySQL server running on port 3306:

{
  "ssh": {
    "host": "remote-server.com",
    "port": 22,
    "username": "myuser",
    "password": "mypassword"
  },
  "tunnel": {
    "source_port": 8080,
    "destination_port": 3306
  },
  "encrypted": false
}

Then run:

./tunnel.exe -config config.json

This will forward all connections to localhost:8080 through the SSH server to remote-server.com:3306.