Shut down the `/api/events` stream when the user logs out or their token expires.

When tokens are revoked (logout or expiry), the server now publishes an internal event via the new `logins` event broadcaster. These events are used to guard the `/api/events` stream. When a token revocation event arrives for the token used to subscribe to the stream, the stream is cut short, disconnecting the client.

In service of this, tokens now have IDs, which are non-confidential values that can be used to discuss tokens without their secrets being passed around unnecessarily. These IDs are not (at this time) exposed to clients, but they could be.

1 files changed, 71 insertions, 3 deletions

diff --git a/src/login/extract.rs b/src/login/extract.rs
index 3b31d4c..b585565 100644
--- a/src/login/extract.rs
+++ b/src/login/extract.rs
@@ -1,12 +1,20 @@
 use std::fmt;
 
 use axum::{
-    extract::FromRequestParts,
-    http::request::Parts,
-    response::{IntoResponseParts, ResponseParts},
+    extract::{FromRequestParts, State},
+    http::{request::Parts, StatusCode},
+    response::{IntoResponse, IntoResponseParts, Response, ResponseParts},
 };
 use axum_extra::extract::cookie::{Cookie, CookieJar};
 
+use crate::{
+    app::App,
+    clock::RequestedAt,
+    error::Internal,
+    login::app::ValidateError,
+    repo::{login::Login, token},
+};
+
 // The usage pattern here - receive the extractor as an argument, return it in
 // the response - is heavily modelled after CookieJar's own intended usage.
 #[derive(Clone)]
@@ -112,3 +120,63 @@ where
         Self(value.into())
     }
 }
+
+#[derive(Clone, Debug)]
+pub struct Identity {
+    pub token: token::Id,
+    pub login: Login,
+}
+
+#[async_trait::async_trait]
+impl FromRequestParts<App> for Identity {
+    type Rejection = LoginError<Internal>;
+
+    async fn from_request_parts(parts: &mut Parts, state: &App) -> Result<Self, Self::Rejection> {
+        // After Rust 1.82 (and #[feature(min_exhaustive_patterns)] lands on
+        // stable), the following can be replaced:
+        //
+        // ```
+        // let Ok(identity_token) = IdentityToken::from_request_parts(
+        //     parts,
+        //     state,
+        // ).await;
+        // ```
+        let identity_token = IdentityToken::from_request_parts(parts, state).await?;
+        let RequestedAt(used_at) = RequestedAt::from_request_parts(parts, state).await?;
+
+        let secret = identity_token.secret().ok_or(LoginError::Unauthorized)?;
+
+        let app = State::<App>::from_request_parts(parts, state).await?;
+        match app.logins().validate(&secret, &used_at).await {
+            Ok((token, login)) => Ok(Identity { token, login }),
+            Err(ValidateError::InvalidToken) => Err(LoginError::Unauthorized),
+            Err(other) => Err(other.into()),
+        }
+    }
+}
+
+pub enum LoginError<E> {
+    Failure(E),
+    Unauthorized,
+}
+
+impl<E> IntoResponse for LoginError<E>
+where
+    E: IntoResponse,
+{
+    fn into_response(self) -> Response {
+        match self {
+            Self::Unauthorized => (StatusCode::UNAUTHORIZED, "unauthorized").into_response(),
+            Self::Failure(e) => e.into_response(),
+        }
+    }
+}
+
+impl<E> From<E> for LoginError<Internal>
+where
+    E: Into<Internal>,
+{
+    fn from(err: E) -> Self {
+        Self::Failure(err.into())
+    }
+}