Fix missing private key for signed fetch (#4516)

* Fix missing private key for signed fetch (fixes #4451)

* clippy

* instance actor name and webfinger

* better webfinger handling

* upgrade lib

* update test asset

Cargo.lock

@@ -16,9 +16,9 @@ checksum = "8f27d075294830fcab6f66e320dab524bc6d048f4a151698e153205559113772"
 
 [[package]]
 name = "activitypub_federation"
-version = "0.5.1"
+version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eee115a53849bbcac6c953495b5f9322b56680c0a1bdef6813183f0453f9ee3c"
+checksum = "a028034c642d3ed16b535f98f48b3df30397833c183d68852d79de16650d5ed5"
 dependencies = [
  "activitystreams-kinds",
  "actix-web",
@@ -2577,7 +2577,6 @@ version = "0.19.3"
 dependencies = [
  "activitypub_federation",
  "actix-web",
- "anyhow",
  "chrono",
  "encoding",
  "enum-map",
@@ -2599,7 +2598,6 @@ dependencies = [
  "serde",
  "serde_with",
  "serial_test",
- "task-local-extensions",
  "tokio",
  "tracing",
  "ts-rs",

Cargo.toml

@@ -96,7 +96,7 @@ lemmy_routes = { version = "=0.19.3", path = "./crates/routes" }
 lemmy_db_views = { version = "=0.19.3", path = "./crates/db_views" }
 lemmy_db_views_actor = { version = "=0.19.3", path = "./crates/db_views_actor" }
 lemmy_db_views_moderator = { version = "=0.19.3", path = "./crates/db_views_moderator" }
-activitypub_federation = { version = "0.5.1", default-features = false, features = [
+activitypub_federation = { version = "0.5.2", default-features = false, features = [
   "actix-web",
 ] }
 diesel = "2.1.4"

crates/apub/assets/lemmy/objects/instance.json

@@ -2,6 +2,7 @@
   "type": "Application",
   "id": "https://enterprise.lemmy.ml/",
   "name": "Enterprise",
+  "preferredUsername": "enterprise.lemmy.ml",
   "summary": "A test instance",
   "content": "<p>Enterprise sidebar</p>\\n",
   "mediaType": "text/html",

crates/apub/src/objects/instance.rs

@@ -96,6 +96,7 @@ impl Object for ApubSite {
       kind: ApplicationType::Application,
       id: self.id().into(),
       name: self.name.clone(),
+      preferred_username: data.domain().to_string(),
       content: self.sidebar.as_ref().map(|d| markdown_to_html(d)),
       source: self.sidebar.clone().map(Source::new),
       summary: self.description.clone(),

crates/apub/src/protocol/objects/instance.rs

@@ -19,8 +19,10 @@ pub struct Instance {
   #[serde(rename = "type")]
   pub(crate) kind: ApplicationType,
   pub(crate) id: ObjectId<ApubSite>,
-  // site name
+  /// site name
   pub(crate) name: String,
+  /// instance domain, necessary for mastodon authorized fetch
+  pub(crate) preferred_username: String,
   pub(crate) inbox: Url,
   /// mandatory field in activitypub, lemmy currently serves an empty outbox
   pub(crate) outbox: Url,

crates/db_schema/src/source/site.rs

@@ -34,7 +34,9 @@ pub struct Site {
   pub last_refreshed_at: DateTime<Utc>,
   /// The site inbox
   pub inbox_url: DbUrl,
+  #[serde(skip)]
   pub private_key: Option<String>,
+  #[serde(skip)]
   pub public_key: String,
   pub instance_id: InstanceId,
   /// If present, nsfw content is visible by default. Should be displayed by frontends/clients

crates/db_views/src/site_view.rs

@@ -9,7 +9,7 @@ use lemmy_db_schema::{
 impl SiteView {
   pub async fn read_local(pool: &mut DbPool<'_>) -> Result<Self, Error> {
     let conn = &mut get_conn(pool).await?;
-    let mut res = site::table
+    site::table
       .inner_join(local_site::table)
       .inner_join(
         local_site_rate_limit::table.on(local_site::id.eq(local_site_rate_limit::local_site_id)),
@@ -22,9 +22,6 @@ impl SiteView {
         site_aggregates::all_columns,
       ))
       .first::<SiteView>(conn)
-      .await?;
-
-    res.site.private_key = None;
-    Ok(res)
+      .await
   }
 }

crates/routes/src/webfinger.rs

@@ -38,6 +38,12 @@ async fn get_webfinger_response(
 ) -> Result<HttpResponse, LemmyError> {
   let name = extract_webfinger_name(&info.resource, &context)?;
 
+  let links = if name == context.settings().hostname {
+    // webfinger response for instance actor (required for mastodon authorized fetch)
+    let url = Url::parse(&context.settings().get_protocol_and_hostname())?;
+    vec![webfinger_link_for_actor(Some(url), "none", &context)]
+  } else {
+    // webfinger response for user/community
     let user_id: Option<Url> = Person::read_from_name(&mut context.pool(), name, false)
       .await
       .ok()
@@ -56,14 +62,18 @@ async fn get_webfinger_response(
 
     // Mastodon seems to prioritize the last webfinger item in case of duplicates. Put
     // community last so that it gets prioritized. For Lemmy the order doesnt matter.
-  let links = vec![
+    vec![
       webfinger_link_for_actor(user_id, "Person", &context),
       webfinger_link_for_actor(community_id, "Group", &context),
     ]
+  }
   .into_iter()
   .flatten()
-  .collect();
+  .collect::<Vec<_>>();
 
+  if links.is_empty() {
+    Ok(HttpResponse::NotFound().finish())
+  } else {
     let json = Webfinger {
       subject: info.resource.clone(),
       links,
@@ -75,6 +85,7 @@ async fn get_webfinger_response(
         .content_type(&WEBFINGER_CONTENT_TYPE)
         .json(json),
     )
+  }
 }
 
 fn webfinger_link_for_actor(