modo/auth/session/cookie/
middleware.rs

1use std::future::Future;
2use std::pin::Pin;
3use std::sync::atomic::{AtomicBool, Ordering};
4use std::sync::{Arc, Mutex};
5use std::task::{Context, Poll};
6
7use axum::body::Body;
8use axum::extract::connect_info::ConnectInfo;
9use cookie::{Cookie, CookieJar, SameSite};
10use http::{HeaderValue, Request, Response};
11use tower::{Layer, Service};
12
13use crate::ip::ClientIp;
14
15use super::CookieSessionService;
16use super::extractor::{SessionAction, SessionState};
17use crate::auth::session::data::Session;
18use crate::auth::session::meta::{SessionMeta, header_str};
19use crate::auth::session::token::SessionToken;
20use crate::cookie::{CookieConfig, Key};
21
22// --- Layer ---
23
24/// Tower [`Layer`] that installs the session middleware into the request pipeline.
25///
26/// Construct with [`layer`] or [`CookieSessionService::layer`] rather than
27/// directly. Apply before route handlers with `Router::layer(session_layer)`.
28///
29/// The middleware reads the signed session cookie, loads the session from the
30/// database, validates the browser fingerprint (when configured), and inserts:
31/// - an `Arc<SessionState>` for the [`super::extractor::CookieSession`] extractor
32/// - a [`crate::auth::session::data::Session`] snapshot for the data extractor
33///
34/// On the response path it flushes dirty session data, touches the expiry
35/// timestamp, and sets or clears the session cookie as needed.
36#[derive(Clone)]
37pub struct CookieSessionLayer {
38    service: CookieSessionService,
39}
40
41/// Create a [`CookieSessionLayer`] from a [`CookieSessionService`].
42///
43/// Prefer [`CookieSessionService::layer`] in application code — this free
44/// function exists so integration tests and advanced callers can assemble the
45/// layer without borrowing the service.
46pub fn layer(service: CookieSessionService) -> CookieSessionLayer {
47    CookieSessionLayer { service }
48}
49
50impl<S> Layer<S> for CookieSessionLayer {
51    type Service = CookieSessionMiddleware<S>;
52
53    fn layer(&self, inner: S) -> Self::Service {
54        CookieSessionMiddleware {
55            inner,
56            service: self.service.clone(),
57        }
58    }
59}
60
61// --- Service ---
62
63/// Tower [`Service`] that manages the session lifecycle for each request.
64///
65/// Produced by [`CookieSessionLayer`]; not constructed directly.
66#[derive(Clone)]
67pub struct CookieSessionMiddleware<S> {
68    inner: S,
69    service: CookieSessionService,
70}
71
72impl<S, ReqBody> Service<Request<ReqBody>> for CookieSessionMiddleware<S>
73where
74    S: Service<Request<ReqBody>, Response = Response<Body>> + Clone + Send + 'static,
75    S::Future: Send + 'static,
76    S::Error: Into<Box<dyn std::error::Error + Send + Sync>> + Send + 'static,
77    ReqBody: Send + 'static,
78{
79    type Response = Response<Body>;
80    type Error = S::Error;
81    type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>> + Send>>;
82
83    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
84        self.inner.poll_ready(cx)
85    }
86
87    fn call(&mut self, mut request: Request<ReqBody>) -> Self::Future {
88        let svc = self.service.clone();
89        let mut inner = self.inner.clone();
90        std::mem::swap(&mut self.inner, &mut inner);
91
92        Box::pin(async move {
93            let store = svc.store();
94            let config = store.config();
95            let cookie_name = &config.cookie_name;
96            let key = svc.cookie_key();
97            let cookie_config = svc.config().cookie.clone();
98
99            let ip = request
100                .extensions()
101                .get::<ClientIp>()
102                .map(|c| c.0.to_string())
103                .unwrap_or_else(|| {
104                    request
105                        .extensions()
106                        .get::<ConnectInfo<std::net::SocketAddr>>()
107                        .map(|ci| ci.0.ip().to_string())
108                        .unwrap_or_else(|| "unknown".to_string())
109                });
110            let headers = request.headers();
111
112            let ua = header_str(headers, "user-agent");
113            let accept_lang = header_str(headers, "accept-language");
114            let accept_enc = header_str(headers, "accept-encoding");
115            let meta = SessionMeta::from_headers(ip, ua, accept_lang, accept_enc);
116
117            let session_token = read_signed_cookie(request.headers(), cookie_name, key);
118            let had_cookie = session_token.is_some();
119
120            let (current_session, read_failed) = if let Some(ref token) = session_token {
121                match store.read_by_token(token).await {
122                    Ok(session) => (session, false),
123                    Err(e) => {
124                        tracing::error!("failed to read session: {e}");
125                        (None, true)
126                    }
127                }
128            } else {
129                (None, false)
130            };
131
132            let current_session = if let Some(session) = current_session {
133                if config.validate_fingerprint && meta.fingerprint != session.fingerprint {
134                    tracing::warn!(
135                        session_id = session.id,
136                        user_id = session.user_id,
137                        "session fingerprint mismatch — possible hijack, destroying session"
138                    );
139                    let _ = store.destroy(&session.id).await;
140                    None
141                } else {
142                    Some(session)
143                }
144            } else {
145                None
146            };
147
148            let should_touch = current_session.as_ref().is_some_and(|s| {
149                let elapsed = chrono::Utc::now() - s.last_active_at;
150                elapsed >= chrono::Duration::seconds(config.touch_interval_secs as i64)
151            });
152
153            if let Some(raw) = current_session.as_ref() {
154                let session_data = Session::from(raw.clone());
155                request.extensions_mut().insert(session_data);
156            }
157
158            let session_state = Arc::new(SessionState {
159                service: svc.clone(),
160                meta,
161                current: Mutex::new(current_session.clone()),
162                dirty: AtomicBool::new(false),
163                action: Mutex::new(SessionAction::None),
164            });
165
166            request.extensions_mut().insert(session_state.clone());
167
168            let mut response = inner.call(request).await?;
169
170            let action = {
171                let guard = session_state.action.lock().expect("session mutex poisoned");
172                guard.clone()
173            };
174            let is_dirty = session_state.dirty.load(Ordering::SeqCst);
175            let ttl_secs = config.session_ttl_secs;
176
177            match action {
178                SessionAction::Set(token) => {
179                    set_signed_cookie(
180                        &mut response,
181                        cookie_name,
182                        &token.as_hex(),
183                        ttl_secs,
184                        &cookie_config,
185                        key,
186                    );
187                }
188                SessionAction::Remove => {
189                    remove_signed_cookie(&mut response, cookie_name, &cookie_config, key);
190                }
191                SessionAction::None => {
192                    if let Some(ref session) = current_session {
193                        let now = chrono::Utc::now();
194                        let new_expires = now + chrono::Duration::seconds(ttl_secs as i64);
195
196                        if is_dirty {
197                            let data = {
198                                let guard = session_state
199                                    .current
200                                    .lock()
201                                    .expect("session mutex poisoned");
202                                guard.as_ref().map(|s| s.data.clone())
203                            };
204                            if let Some(data) = data
205                                && let Err(e) =
206                                    store.flush(&session.id, &data, now, new_expires).await
207                            {
208                                tracing::error!(
209                                    session_id = session.id,
210                                    "failed to flush session data: {e}"
211                                );
212                            }
213                        } else if should_touch
214                            && let Err(e) = store.touch(&session.id, now, new_expires).await
215                        {
216                            tracing::error!(
217                                session_id = session.id,
218                                "failed to touch session: {e}"
219                            );
220                        }
221
222                        if (is_dirty || should_touch)
223                            && let Some(ref token) = session_token
224                        {
225                            set_signed_cookie(
226                                &mut response,
227                                cookie_name,
228                                &token.as_hex(),
229                                ttl_secs,
230                                &cookie_config,
231                                key,
232                            );
233                        }
234                    }
235
236                    if had_cookie && current_session.is_none() && !read_failed {
237                        remove_signed_cookie(&mut response, cookie_name, &cookie_config, key);
238                    }
239                }
240            }
241
242            Ok(response)
243        })
244    }
245}
246
247/// Read a signed cookie value from request headers.
248/// Returns `Some(SessionToken)` if the cookie exists, signature is valid, and hex decodes.
249fn read_signed_cookie(
250    headers: &http::HeaderMap,
251    cookie_name: &str,
252    key: &Key,
253) -> Option<SessionToken> {
254    let cookie_header = headers.get(http::header::COOKIE)?;
255    let cookie_str = cookie_header.to_str().ok()?;
256
257    for pair in cookie_str.split(';') {
258        let pair = pair.trim();
259        if let Some((name, value)) = pair.split_once('=')
260            && name.trim() == cookie_name
261        {
262            let mut jar = CookieJar::new();
263            jar.add_original(Cookie::new(
264                cookie_name.to_string(),
265                value.trim().to_string(),
266            ));
267            let verified = jar.signed(key).get(cookie_name)?;
268            return SessionToken::from_hex(verified.value()).ok();
269        }
270    }
271    None
272}
273
274/// Sign a cookie value and append Set-Cookie header to response.
275fn set_signed_cookie(
276    response: &mut Response<Body>,
277    name: &str,
278    value: &str,
279    max_age_secs: u64,
280    config: &CookieConfig,
281    key: &Key,
282) {
283    // Sign the value
284    let mut jar = CookieJar::new();
285    jar.signed_mut(key)
286        .add(Cookie::new(name.to_string(), value.to_string()));
287    let signed_value = jar
288        .get(name)
289        .expect("cookie was just added")
290        .value()
291        .to_string();
292
293    let same_site = match config.same_site.as_str() {
294        "strict" => SameSite::Strict,
295        "none" => SameSite::None,
296        _ => SameSite::Lax,
297    };
298    let set_cookie_str = Cookie::build((name.to_string(), signed_value))
299        .path("/")
300        .secure(config.secure)
301        .http_only(config.http_only)
302        .same_site(same_site)
303        .max_age(cookie::time::Duration::seconds(max_age_secs as i64))
304        .build()
305        .to_string();
306
307    match HeaderValue::from_str(&set_cookie_str) {
308        Ok(v) => {
309            response.headers_mut().append(http::header::SET_COOKIE, v);
310        }
311        Err(e) => {
312            tracing::error!(
313                cookie_name = name,
314                "failed to set session cookie header: {e}"
315            );
316        }
317    }
318}
319
320fn remove_signed_cookie(
321    response: &mut Response<Body>,
322    name: &str,
323    config: &CookieConfig,
324    key: &Key,
325) {
326    set_signed_cookie(response, name, "", 0, config, key);
327}
modo/auth/session/cookie/middleware.rs

modo/auth/session/cookie/
middleware.rs
