data-model: Make the user_id optional in the OAuth 2.0 sessions

crates/graphql/src/lib.rs

@@ -63,7 +63,7 @@ pub enum Requester {
     BrowserSession(BrowserSession),
 
     /// The requester is a OAuth2 session, with an access token.
-    OAuth2Session(Session, User),
+    OAuth2Session(Session, Option<User>),
 }
 
 trait OwnerId {
@@ -90,7 +90,7 @@ impl OwnerId for mas_data_model::UserEmail {
 
 impl OwnerId for Session {
     fn owner_id(&self) -> Option<Ulid> {
-        Some(self.user_id)
+        self.user_id
     }
 }
 
@@ -126,7 +126,7 @@ impl Requester {
     fn user(&self) -> Option<&User> {
         match self {
             Self::BrowserSession(session) => Some(&session.user),
-            Self::OAuth2Session(_session, user) => Some(user),
+            Self::OAuth2Session(_session, user) => user.as_ref(),
             Self::Anonymous => None,
         }
     }

crates/graphql/src/model/oauth.rs

@@ -22,7 +22,7 @@ use ulid::Ulid;
 use url::Url;
 
 use super::{BrowserSession, NodeType, User};
-use crate::state::ContextExt;
+use crate::{state::ContextExt, UserId};
 
 /// The state of an OAuth 2.0 session.
 #[derive(Enum, Copy, Clone, Eq, PartialEq)]
@@ -108,17 +108,25 @@ impl OAuth2Session {
     }
 
     /// User authorized for this session.
-    pub async fn user(&self, ctx: &Context<'_>) -> Result<User, async_graphql::Error> {
+    pub async fn user(&self, ctx: &Context<'_>) -> Result<Option<User>, async_graphql::Error> {
         let state = ctx.state();
+        let Some(user_id) = self.0.user_id else {
+            return Ok(None);
+        };
+
+        if !ctx.requester().is_owner_or_admin(&UserId(user_id)) {
+            return Err(async_graphql::Error::new("Unauthorized"));
+        }
+
         let mut repo = state.repository().await?;
         let user = repo
             .user()
-            .lookup(self.0.user_id)
+            .lookup(user_id)
             .await?
             .context("Could not load user")?;
         repo.cancel().await?;
 
-        Ok(User(user))
+        Ok(Some(User(user)))
     }
 }
 

crates/graphql/src/mutations/oauth2_session.rs

@@ -96,24 +96,26 @@ impl OAuth2SessionMutations {
             return Ok(EndOAuth2SessionPayload::NotFound);
         }
 
-        let user = repo
-            .user()
-            .lookup(session.user_id)
-            .await?
-            .context("Could not load user")?;
+        if let Some(user_id) = session.user_id {
+            let user = repo
+                .user()
+                .lookup(user_id)
+                .await?
+                .context("Could not load user")?;
 
-        // Scan the scopes of the session to find if there is any device that should be
-        // deleted from the Matrix server.
-        // TODO: this should be moved in a higher level "end oauth session" method.
-        // XXX: this might not be the right semantic, but it's the best we
-        // can do for now, since we're not explicitly storing devices for OAuth2
-        // sessions.
-        for scope in &*session.scope {
-            if let Some(device) = Device::from_scope_token(scope) {
-                // Schedule a job to delete the device.
-                repo.job()
-                    .schedule_job(DeleteDeviceJob::new(&user, &device))
-                    .await?;
+            // Scan the scopes of the session to find if there is any device that should be
+            // deleted from the Matrix server.
+            // TODO: this should be moved in a higher level "end oauth session" method.
+            // XXX: this might not be the right semantic, but it's the best we
+            // can do for now, since we're not explicitly storing devices for OAuth2
+            // sessions.
+            for scope in &*session.scope {
+                if let Some(device) = Device::from_scope_token(scope) {
+                    // Schedule a job to delete the device.
+                    repo.job()
+                        .schedule_job(DeleteDeviceJob::new(&user, &device))
+                        .await?;
+                }
             }
         }
 

crates/graphql/src/query/viewer.rs

@@ -31,8 +31,8 @@ impl ViewerQuery {
 
         match requester {
             Requester::BrowserSession(session) => Viewer::user(session.user.clone()),
-            Requester::OAuth2Session(_session, user) => Viewer::user(user.clone()),
-            Requester::Anonymous => Viewer::anonymous(),
+            Requester::OAuth2Session(_session, Some(user)) => Viewer::user(user.clone()),
+            Requester::OAuth2Session(_, None) | Requester::Anonymous => Viewer::anonymous(),
         }
     }