allowthem-server 0.0.6

HTTP server and middleware for allowthem
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395

use axum::body::Body;
use axum::extract::FromRef;
use axum::http::{Request, StatusCode, header::COOKIE};
use axum::middleware::Next;
use axum::response::{IntoResponse, Response};
use serde_json::json;

use std::sync::Arc;

use allowthem_core::{AuthClient, AuthError, PermissionName, RoleName, User, parse_session_cookie};

/// Axum middleware that requires a valid authenticated session.
///
/// Validates the session cookie, fetches the user, and inserts the [`User`]
/// into request extensions so downstream handlers can access it cheaply via
/// `Extension<User>`. Returns 401 JSON on any authentication failure.
///
/// Apply to a route group with `axum::middleware::from_fn_with_state(ath, require_auth)`.
pub async fn require_auth<S>(
    state: axum::extract::State<S>,
    mut request: Request<Body>,
    next: Next,
) -> Response
where
    Arc<dyn AuthClient>: FromRef<S>,
    S: Send + Sync + Clone,
{
    let client = <Arc<dyn AuthClient>>::from_ref(&*state);
    // Clone the headers out before any await so we don't hold &Request<Body>
    // (Body is not Sync) across an await point.
    let headers = request.headers().clone();

    let user = match authenticate(&*client, &headers).await {
        Ok(u) => u,
        Err(r) => return r,
    };

    request.extensions_mut().insert(user);
    next.run(request).await
}

/// Middleware factory that requires the authenticated user to have a specific role.
///
/// Builds on `require_auth`: first validates the session (inserting `User` into
/// extensions), then checks the role. Returns 401 if not authenticated, 403 if
/// authenticated but missing the role.
///
/// Usage:
/// ```ignore
/// use axum::middleware;
///
/// let app = Router::new()
///     .route("/admin", get(handler))
///     .layer(middleware::from_fn_with_state(
///         ath.clone(),
///         require_role("admin"),
///     ));
/// ```
pub fn require_role<S>(
    role: impl Into<String>,
) -> impl Fn(
    axum::extract::State<S>,
    Request<Body>,
    Next,
) -> std::pin::Pin<Box<dyn std::future::Future<Output = Response> + Send>>
+ Clone
+ Send
+ 'static
where
    Arc<dyn AuthClient>: FromRef<S>,
    S: Send + Sync + Clone + 'static,
{
    let role_name = role.into();
    move |state, request, next| {
        let role_name = role_name.clone();
        Box::pin(require_role_inner(state, request, next, role_name))
    }
}

async fn require_role_inner<S>(
    state: axum::extract::State<S>,
    mut request: Request<Body>,
    next: Next,
    role_name: String,
) -> Response
where
    Arc<dyn AuthClient>: FromRef<S>,
    S: Send + Sync + Clone,
{
    let client = <Arc<dyn AuthClient>>::from_ref(&*state);
    let headers = request.headers().clone();

    let user = match authenticate(&*client, &headers).await {
        Ok(u) => u,
        Err(r) => return r,
    };

    let rn = RoleName::new(role_name);
    match client.check_role(&user.id, &rn).await {
        Ok(true) => {}
        Ok(false) => {
            return (
                StatusCode::FORBIDDEN,
                axum::Json(json!({"error": "forbidden"})),
            )
                .into_response();
        }
        Err(e) => return internal_error(e),
    }

    request.extensions_mut().insert(user);
    next.run(request).await
}

/// Middleware factory that requires the authenticated user to have a specific permission.
///
/// Works identically to [`require_role`] but checks permissions instead of roles.
/// Permissions are checked via both direct assignment and role membership.
///
/// Returns 401 if not authenticated, 403 if authenticated but missing the permission.
pub fn require_permission<S>(
    permission: impl Into<String>,
) -> impl Fn(
    axum::extract::State<S>,
    Request<Body>,
    Next,
) -> std::pin::Pin<Box<dyn std::future::Future<Output = Response> + Send>>
+ Clone
+ Send
+ 'static
where
    Arc<dyn AuthClient>: FromRef<S>,
    S: Send + Sync + Clone + 'static,
{
    let perm_name = permission.into();
    move |state, request, next| {
        let perm_name = perm_name.clone();
        Box::pin(require_permission_inner(state, request, next, perm_name))
    }
}

async fn require_permission_inner<S>(
    state: axum::extract::State<S>,
    mut request: Request<Body>,
    next: Next,
    perm_name: String,
) -> Response
where
    Arc<dyn AuthClient>: FromRef<S>,
    S: Send + Sync + Clone,
{
    let client = <Arc<dyn AuthClient>>::from_ref(&*state);
    let headers = request.headers().clone();

    let user = match authenticate(&*client, &headers).await {
        Ok(u) => u,
        Err(r) => return r,
    };

    let pn = PermissionName::new(perm_name);
    match client.check_permission(&user.id, &pn).await {
        Ok(true) => {}
        Ok(false) => {
            return (
                StatusCode::FORBIDDEN,
                axum::Json(json!({"error": "forbidden"})),
            )
                .into_response();
        }
        Err(e) => return internal_error(e),
    }

    request.extensions_mut().insert(user);
    next.run(request).await
}

/// Shared authentication logic: parse cookie and validate session.
///
/// Takes the headers directly so the caller does not hold a `&Request<Body>` reference
/// across await points (Body is not Sync).
///
/// Returns the active `User` on success, or an `IntoResponse` error response.
async fn authenticate(
    client: &dyn AuthClient,
    headers: &axum::http::HeaderMap,
) -> Result<User, Response> {
    let cookie_header = headers
        .get(COOKIE)
        .and_then(|v| v.to_str().ok())
        .ok_or_else(unauthenticated)?
        .to_string();

    let token = parse_session_cookie(&cookie_header, client.session_cookie_name())
        .ok_or_else(unauthenticated)?;

    let user = client
        .validate_session(&token)
        .await
        .map_err(internal_error)?
        .ok_or_else(unauthenticated)?;

    Ok(user)
}

fn unauthenticated() -> Response {
    (
        StatusCode::UNAUTHORIZED,
        axum::Json(json!({"error": "unauthenticated"})),
    )
        .into_response()
}

fn internal_error(err: AuthError) -> Response {
    tracing::error!("auth middleware error: {err}");
    (
        StatusCode::INTERNAL_SERVER_ERROR,
        axum::Json(json!({"error": "internal error"})),
    )
        .into_response()
}

#[cfg(test)]
mod tests {
    use std::sync::Arc;

    use super::*;
    use allowthem_core::{
        AllowThem, AllowThemBuilder, AuthClient, Email, EmbeddedAuthClient, generate_token,
        hash_token,
    };
    use axum::extract::FromRef;
    use axum::http::StatusCode;
    use axum::routing::get;
    use axum::{Router, middleware};
    use chrono::{Duration, Utc};
    use tower::ServiceExt;

    #[derive(Clone)]
    struct TestState {
        auth: Arc<dyn AuthClient>,
    }

    impl FromRef<TestState> for Arc<dyn AuthClient> {
        fn from_ref(s: &TestState) -> Self {
            Arc::clone(&s.auth)
        }
    }

    /// Build AllowThem, create a user with an active session, return (AllowThem, cookie_value).
    async fn test_setup() -> (AllowThem, String) {
        let ath = AllowThemBuilder::new("sqlite::memory:")
            .cookie_secure(false)
            .build()
            .await
            .unwrap();

        let email = Email::new("user@example.com".into()).unwrap();
        let user = ath
            .db()
            .create_user(email, "password123", None, None)
            .await
            .unwrap();

        let token = generate_token();
        let token_hash = hash_token(&token);
        let expires = Utc::now() + Duration::hours(24);
        ath.db()
            .create_session(user.id, token_hash, None, None, expires)
            .await
            .unwrap();

        let cookie = ath.session_cookie(&token);
        let cookie_value = cookie.split(';').next().unwrap().to_string();
        (ath, cookie_value)
    }

    async fn ok_handler() -> StatusCode {
        StatusCode::OK
    }

    fn auth_app(ath: AllowThem) -> Router {
        let auth: Arc<dyn AuthClient> = Arc::new(EmbeddedAuthClient::new(ath, "/login"));
        let state = TestState { auth };
        Router::new()
            .route("/protected", get(ok_handler))
            .layer(middleware::from_fn_with_state(
                state.clone(),
                require_auth::<TestState>,
            ))
            .with_state(state)
    }

    fn role_app(ath: AllowThem, role: &str) -> Router {
        let role = role.to_string();
        let auth: Arc<dyn AuthClient> = Arc::new(EmbeddedAuthClient::new(ath, "/login"));
        let state = TestState { auth };
        Router::new()
            .route("/protected", get(ok_handler))
            .layer(middleware::from_fn_with_state(
                state.clone(),
                require_role::<TestState>(role),
            ))
            .with_state(state)
    }

    fn perm_app(ath: AllowThem, perm: &str) -> Router {
        let perm = perm.to_string();
        let auth: Arc<dyn AuthClient> = Arc::new(EmbeddedAuthClient::new(ath, "/login"));
        let state = TestState { auth };
        Router::new()
            .route("/protected", get(ok_handler))
            .layer(middleware::from_fn_with_state(
                state.clone(),
                require_permission::<TestState>(perm),
            ))
            .with_state(state)
    }

    fn make_request(cookie: Option<&str>) -> axum::http::Request<Body> {
        let mut builder = axum::http::Request::builder().uri("/protected");
        if let Some(c) = cookie {
            builder = builder.header(COOKIE, c);
        }
        builder.body(Body::empty()).unwrap()
    }

    #[tokio::test]
    async fn authenticated_request_passes_through() {
        let (ath, cookie) = test_setup().await;
        let app = auth_app(ath);
        let resp = app.oneshot(make_request(Some(&cookie))).await.unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
    }

    #[tokio::test]
    async fn unauthenticated_request_returns_401() {
        let (ath, _) = test_setup().await;
        let app = auth_app(ath);
        let resp = app.oneshot(make_request(None)).await.unwrap();
        assert_eq!(resp.status(), StatusCode::UNAUTHORIZED);
    }

    #[tokio::test]
    async fn require_role_with_correct_role_passes() {
        let (ath, cookie) = test_setup().await;

        // Create role and assign to user.
        let rn = allowthem_core::RoleName::new("admin");
        let role = ath.db().create_role(&rn, None).await.unwrap();
        let email = Email::new("user@example.com".into()).unwrap();
        let user = ath.db().get_user_by_email(&email).await.unwrap();
        ath.db().assign_role(&user.id, &role.id).await.unwrap();

        let app = role_app(ath, "admin");
        let resp = app.oneshot(make_request(Some(&cookie))).await.unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
    }

    #[tokio::test]
    async fn require_role_with_wrong_role_returns_403() {
        let (ath, cookie) = test_setup().await;
        // User has no roles assigned.
        let app = role_app(ath, "admin");
        let resp = app.oneshot(make_request(Some(&cookie))).await.unwrap();
        assert_eq!(resp.status(), StatusCode::FORBIDDEN);
    }

    #[tokio::test]
    async fn require_permission_with_correct_permission_passes() {
        let (ath, cookie) = test_setup().await;

        // Create permission and assign directly to user.
        let pn = allowthem_core::PermissionName::new("posts:write");
        let perm = ath.db().create_permission(&pn, None).await.unwrap();
        let email = Email::new("user@example.com".into()).unwrap();
        let user = ath.db().get_user_by_email(&email).await.unwrap();
        ath.db()
            .assign_permission_to_user(&user.id, &perm.id)
            .await
            .unwrap();

        let app = perm_app(ath, "posts:write");
        let resp = app.oneshot(make_request(Some(&cookie))).await.unwrap();
        assert_eq!(resp.status(), StatusCode::OK);
    }

    #[tokio::test]
    async fn require_permission_with_missing_permission_returns_403() {
        let (ath, cookie) = test_setup().await;
        // User has no permissions.
        let app = perm_app(ath, "posts:write");
        let resp = app.oneshot(make_request(Some(&cookie))).await.unwrap();
        assert_eq!(resp.status(), StatusCode::FORBIDDEN);
    }
}