Improve security for public file serving

[KjetilIN]

What?

Within the ./public/ folder, there are files that can be served as they are. For now, the function is private, but to improve the code, one can implement functions for serving the files more secure.

Such as validating the input. The function is currently very simple, and is currently NOT A SECURITY ISSUE (due to hard-coded paths)

This is the code that needs improvement in the feature:

fn serve_public_file(file_name:&str, content_type: &str, request: Request) -> (){
    let file = format!("./src/public/{}", file_name);
    let content = read_file(&file);

    match content{
        Ok(ct) => {
            let response = Response::from_string(ct)
                                                                .with_header(tiny_http::Header::from_bytes(&b"Content-Type"[..], &content_type.as_bytes()[..]).unwrap());

            let _ = request.respond(response);
            return; 
        },
        Err(_) => {
            eprintln!("[ERROR] Could not read {}", file_name);
        },
    }
}

pub fn handle_get_request(request: Request)-> (){
    // Serve based on the url
    match request.url(){
        // INDEX File
        "/" => serve_public_file("index.html", "text/html", request),
        // Serving the styles request 
        "/style.css" => serve_public_file("style.css", "text/css", request),
        _ => {}
    }
}
``