add cookie utils module for requests and responses

peach-web/src/utils/cookie.rs

@@ -0,0 +1,64 @@
+use rouille::{input, Request, Response};
+
+// The CookieRequest and CookieResponse traits are currently only used
+// to add, retrieve and reset the `back_url` cookie. That cookie is
+// used to set the URL of the in-UI back button when visiting a page
+// which can be arrived at via several paths.
+//
+// An example of this is the Scuttlebutt Settings menu (/settings/scuttlebutt),
+// which can be accessed via the Settings menu (/settings) or the Scuttlebutt
+// Status page (/status/scuttlebutt). We need to be able to set the path of
+// the back button to point to the correct page (ie. the one from which we've
+// come).
+//
+// The `back_url` cookie is also used on the Profile page
+// (/scuttlebutt/profile).
+
+/// Cookie trait for `Request`.
+pub trait CookieRequest {
+    /// Retrieve a cookie value from a `Request`.
+    fn retrieve_cookie(&self, cookie_name: &str) -> Option<&str>;
+}
+
+impl CookieRequest for Request {
+    fn retrieve_cookie(&self, cookie_name: &str) -> Option<&str> {
+        // check for cookie using given name
+        let cookie_val = input::cookies(self)
+            .find(|&(n, _)| n == cookie_name)
+            // return the value of the cookie (key is already known)
+            .map(|key_val| key_val.1);
+
+        cookie_val
+    }
+}
+
+/// Cookie trait for `Response`.
+pub trait CookieResponse {
+    /// Add a cookie containing the given data to a `Response`. Data should be
+    /// in the form of `cookie_name=cookie_val`.
+    fn add_cookie(self, cookie_name_val: &str) -> Response;
+    /// Reset a cookie value for a `Response`.
+    fn reset_cookie(self, cookie_name: &str) -> Response;
+}
+
+impl CookieResponse for Response {
+    fn add_cookie(self, cookie_name_val: &str) -> Response {
+        // set the cookie header
+        // max-age is currently set to 3600 seconds (1 hour)
+        self.with_additional_header(
+            "Set-Cookie",
+            format!("{}; Max-Age=3600; SameSite=Lax; Path=/", cookie_name_val),
+        )
+    }
+
+    fn reset_cookie(self, cookie_name: &str) -> Response {
+        // set a blank cookie to clear the cookie from the previous request
+        self.with_additional_header(
+            "Set-Cookie",
+            format!(
+                "{}=; Max-Age=0; SameSite=Lax; Path=/; Expires=Fri, 21 Aug 1987 12:00:00 UTC",
+                cookie_name
+            ),
+        )
+    }
+}

peach-web/src/utils/mod.rs

@@ -1,3 +1,4 @@
+pub mod cookie;
 pub mod flash;
 pub mod sbot;
 pub mod theme;