Revert "Remove barebone CSRF protection fairing"

This reverts commit 4ec439a6f3.

src/csrf.rs

@@ -0,0 +1,27 @@
+use rocket::{Data, Request};
+use rocket::fairing::{Fairing as RocketFairing, Info, Kind};
+
+const COOKIE_NAME: &str = "csrf_token";
+
+pub struct Fairing;
+
+impl Fairing {
+    pub fn new() -> Self {
+        Self {}
+    }
+}
+
+impl RocketFairing for Fairing {
+    fn info(&self) -> Info {
+        Info {
+            name: "CSRF (Cross-Site Request Forgery) protection",
+            kind: Kind::Request,
+        }
+    }
+
+    fn on_request(&self, request: &mut Request, _: &Data) {
+        let _token: Option<String> = request.cookies()
+            .get_private(COOKIE_NAME)
+            .and_then(|cookie| Some(cookie.value().to_string()));
+    }
+}

src/main.rs

@@ -2,6 +2,7 @@
 
 #[cfg(test)] mod tests;
 
+mod csrf;
 mod config;
 mod web;
 mod database;

src/web.rs

@@ -1,3 +1,4 @@
+use crate::csrf;
 use crate::config;
 use crate::database;
 use crate::routes;
@@ -10,10 +11,9 @@ pub fn rocket(config: &config::Config) -> Result<rocket::Rocket, ()> {
 
     let public_path = config.public_path()?;
 
-    let secret_key = config.secret_key.as_ref().unwrap().to_string();
-
     let result = rocket::custom(rocket_config)
         .manage(database::create_db_pool(config))
+        .attach(csrf::Fairing::new())
         .attach(Template::fairing())
         .mount("/", routes::routes())
         .mount("/", StaticFiles::new(public_path, ServeOptions::None));