Handle user gone and fix more public key stuff

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/service/activity_pub/activity_pub.ex

@@ -203,6 +203,10 @@ defmodule Mobilizon.Service.ActivityPub do
     with {:ok, data} <- fetch_and_prepare_user_from_url(url) do
       Actors.insert_or_update_actor(data)
     else
+      # Request returned 410
+      {:error, :actor_deleted} ->
+        {:error, :actor_deleted}
+
       e ->
         Logger.error("Failed to make actor from url")
         Logger.error(inspect(e))
@@ -283,12 +287,18 @@ defmodule Mobilizon.Service.ActivityPub do
   def fetch_and_prepare_user_from_url(url) do
     Logger.debug("Fetching and preparing user from url")
 
-    with {:ok, %{status_code: 200, body: body}} <-
+    with {:ok, %HTTPoison.Response{status_code: 200, body: body}} <-
            HTTPoison.get(url, [Accept: "application/activity+json"], follow_redirect: true),
          {:ok, data} <- Jason.decode(body) do
       user_data_from_user_object(data)
     else
-      e -> Logger.error("Could not decode user at fetch #{url}, #{inspect(e)}")
+      # User is gone, probably deleted
+      {:ok, %HTTPoison.Response{status_code: 410}} ->
+        {:error, :actor_deleted}
+
+      e ->
+        Logger.error("Could not decode user at fetch #{url}, #{inspect(e)}")
+        e
     end
   end
 

lib/service/http_signatures/http_signatures.ex

@@ -44,14 +44,17 @@ defmodule Mobilizon.Service.HTTPSignatures do
   defp prepare_public_key(public_key_code) do
     with [public_key_entry] <- :public_key.pem_decode(public_key_code) do
       :public_key.pem_entry_decode(public_key_entry)
+    else
+      _err ->
+        {:error, :pem_decode_error}
     end
   end
 
   def validate_conn(conn) do
     # TODO: How to get the right key and see if it is actually valid for that request.
     # For now, fetch the key for the actor.
-    with public_key <-
-           conn.params["actor"] |> Actor.get_public_key_for_url() |> prepare_public_key() do
+    with {:ok, public_key} <- conn.params["actor"] |> Actor.get_public_key_for_url(),
+         {:ok, public_key} <- prepare_public_key(public_key) do
       if validate_conn(conn, public_key) do
         true
       else
@@ -59,7 +62,8 @@ defmodule Mobilizon.Service.HTTPSignatures do
         # Fetch user anew and try one more time
         with actor_id <- conn.params["actor"],
              {:ok, _actor} <- ActivityPub.make_actor_from_url(actor_id),
-             public_key <- actor_id |> Actor.get_public_key_for_url() |> prepare_public_key() do
+             {:ok, public_key} <- actor_id |> Actor.get_public_key_for_url(),
+             {:ok, public_key} <- prepare_public_key(public_key) do
           validate_conn(conn, public_key)
         end
       end