Federate user deletion (#551)

* Federate user deletion

- When someone deletes their account
- When a local user is banned

Fixes #509

* cargo fmt

plume-models/src/inbox.rs

@@ -53,6 +53,7 @@ pub fn inbox(ctx: &PlumeRocket, act: serde_json::Value) -> Result<InboxResult, E
         .with::<User, Create, Post>()
         .with::<User, Delete, Comment>()
         .with::<User, Delete, Post>()
+        .with::<User, Delete, User>()
         .with::<User, Follow, User>()
         .with::<User, Like, Post>()
         .with::<User, Undo, Reshare>()
@@ -286,6 +287,34 @@ pub(crate) mod tests {
         });
     }
 
+    #[test]
+    fn delete_user() {
+        let r = rockets();
+        let conn = &*r.conn;
+        conn.test_transaction::<_, (), _>(|| {
+            let (_, users, _) = fill_database(&r);
+
+            let fail_act = json!({
+                "id": "https://plu.me/@/Admin#delete",
+                "actor": users[1].ap_url, // Not the same account
+                "object": users[0].ap_url,
+                "type": "Delete",
+            });
+            assert!(super::inbox(&r, fail_act).is_err());
+
+            let ok_act = json!({
+                "id": "https://plu.me/@/Admin#delete",
+                "actor": users[0].ap_url,
+                "object": users[0].ap_url,
+                "type": "Delete",
+            });
+            assert!(super::inbox(&r, ok_act).is_ok());
+            assert!(crate::users::User::get(conn, users[0].id).is_err());
+
+            Ok(())
+        });
+    }
+
     #[test]
     fn follow() {
         let r = rockets();

plume-models/src/users.rs

@@ -1,5 +1,9 @@
 use activitypub::{
-    actor::Person, collection::OrderedCollection, object::Image, Activity, CustomObject, Endpoint,
+    activity::Delete,
+    actor::Person,
+    collection::OrderedCollection,
+    object::{Image, Tombstone},
+    Activity, CustomObject, Endpoint,
 };
 use bcrypt;
 use chrono::{NaiveDateTime, Utc};
@@ -12,9 +16,9 @@ use openssl::{
 };
 use plume_common::activity_pub::{
     ap_accept_header,
-    inbox::{AsActor, FromId},
+    inbox::{AsActor, AsObject, FromId},
     sign::{gen_keypair, Signer},
-    ActivityStream, ApSignature, Id, IntoId, PublicKey,
+    ActivityStream, ApSignature, Id, IntoId, PublicKey, PUBLIC_VISIBILITY,
 };
 use plume_common::utils;
 use reqwest::{
@@ -632,6 +636,29 @@ impl User {
         Ok(CustomPerson::new(actor, ap_signature))
     }
 
+    pub fn delete_activity(&self, conn: &Connection) -> Result<Delete> {
+        let mut del = Delete::default();
+
+        let mut tombstone = Tombstone::default();
+        tombstone.object_props.set_id_string(self.ap_url.clone())?;
+
+        del.delete_props
+            .set_actor_link(Id::new(self.ap_url.clone()))?;
+        del.delete_props.set_object_object(tombstone)?;
+        del.object_props
+            .set_id_string(format!("{}#delete", self.ap_url))?;
+        del.object_props
+            .set_to_link_vec(vec![Id::new(PUBLIC_VISIBILITY)])?;
+        del.object_props.set_cc_link_vec(
+            self.get_followers(conn)?
+                .into_iter()
+                .map(|f| Id::new(f.ap_url))
+                .collect(),
+        )?;
+
+        Ok(del)
+    }
+
     pub fn avatar_url(&self, conn: &Connection) -> String {
         self.avatar_id
             .and_then(|id| Media::get(conn, id).and_then(|m| m.url(conn)).ok())
@@ -832,6 +859,19 @@ impl AsActor<&PlumeRocket> for User {
     }
 }
 
+impl AsObject<User, Delete, &PlumeRocket> for User {
+    type Error = Error;
+    type Output = ();
+
+    fn activity(self, c: &PlumeRocket, actor: User, _id: &str) -> Result<()> {
+        if self.id == actor.id {
+            self.delete(&c.conn, &c.searcher).map(|_| ())
+        } else {
+            Err(Error::Unauthorized)
+        }
+    }
+}
+
 impl Signer for User {
     type Error = Error;