Various HTTP signature code improvements

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

lib/web/plugs/http_signatures.ex

@@ -36,14 +36,7 @@ defmodule Mobilizon.Web.Plugs.HTTPSignatures do
           "(request-target)",
           String.downcase("#{conn.method}") <> " #{conn.request_path}"
         )
-
-      conn =
-        if conn.assigns[:digest] do
-          conn
-          |> put_req_header("digest", conn.assigns[:digest])
-        else
-          conn
-        end
+        |> maybe_put_digest_header()
 
       signature_valid = HTTPSignatures.validate_conn(conn)
       Logger.debug("Is signature valid ? #{inspect(signature_valid)}")
@@ -53,6 +46,11 @@ defmodule Mobilizon.Web.Plugs.HTTPSignatures do
     end
   end
 
+  defp maybe_put_digest_header(%Plug.Conn{assigns: %{digest: digest}} = conn),
+    do: put_req_header(conn, "digest", digest)
+
+  defp maybe_put_digest_header(%Plug.Conn{} = conn), do: conn
+
   @spec date_valid?(Plug.Conn.t()) :: boolean()
   defp date_valid?(conn) do
     date = conn |> get_req_header("date") |> List.first()

lib/web/plugs/mapped_signature_to_identity.ex

@@ -11,7 +11,6 @@ defmodule Mobilizon.Web.Plugs.MappedSignatureToIdentity do
   import Plug.Conn
 
   alias Mobilizon.Actors.Actor
-
   alias Mobilizon.Federation.ActivityPub.Actor, as: ActivityPubActor
   alias Mobilizon.Federation.ActivityPub.Utils
   alias Mobilizon.Federation.HTTPSignatures.Signature
@@ -32,16 +31,20 @@ defmodule Mobilizon.Web.Plugs.MappedSignatureToIdentity do
     end
   end
 
-  @spec actor_from_key_id(Plug.Conn.t()) :: Actor.t() | nil
+  @spec actor_from_key_id(Plug.Conn.t()) ::
+          {:ok, Actor.t()} | {:error, :actor_not_found | :no_key_in_conn}
   defp actor_from_key_id(conn) do
     Logger.debug("Determining actor from connection signature")
 
-    with key_actor_id when is_binary(key_actor_id) <- key_id_from_conn(conn),
-         {:ok, %Actor{} = actor} <- ActivityPubActor.get_or_fetch_actor_by_url(key_actor_id) do
-      actor
-    else
-      _ ->
-        nil
+    case key_id_from_conn(conn) do
+      key_actor_id when is_binary(key_actor_id) ->
+        # We don't need to call refreshment here since
+        # the Mobilizon.Federation.HTTPSignatures.Signature plug
+        # should already have refreshed the actor if needed
+        ActivityPubActor.make_actor_from_url(key_actor_id, ignore_sign_object_fetches: true)
+
+      nil ->
+        {:error, :no_key_in_conn}
     end
   end
 
@@ -51,7 +54,7 @@ defmodule Mobilizon.Web.Plugs.MappedSignatureToIdentity do
   # if this has payload make sure it is signed by the same actor that made it
   def call(%{assigns: %{valid_signature: true}, params: %{"actor" => actor}} = conn, _opts) do
     with actor_id when actor_id != nil <- Utils.get_url(actor),
-         {:actor, %Actor{} = actor} <- {:actor, actor_from_key_id(conn)},
+         {:ok, %Actor{} = actor} <- actor_from_key_id(conn),
          {:actor_match, true} <- {:actor_match, actor.url == actor_id} do
       Logger.debug("Mapped identity to #{actor.url} from actor param")
       assign(conn, :actor, actor)
@@ -61,8 +64,12 @@ defmodule Mobilizon.Web.Plugs.MappedSignatureToIdentity do
         Logger.debug("key_id=#{key_id_from_conn(conn)}, actor=#{actor}")
         assign(conn, :valid_signature, false)
 
+      {:error, :no_key_in_conn} ->
+        Logger.debug("There was no key in conn")
+        conn
+
       # TODO: remove me once testsuite uses mapped capabilities instead of what we do now
-      {:actor, nil} ->
+      {:error, :actor_not_found} ->
         Logger.debug("Failed to map identity from signature (lookup failure)")
         Logger.debug("key_id=#{key_id_from_conn(conn)}, actor=#{actor}")
         conn
@@ -72,11 +79,15 @@ defmodule Mobilizon.Web.Plugs.MappedSignatureToIdentity do
   # no payload, probably a signed fetch
   def call(%{assigns: %{valid_signature: true}} = conn, _opts) do
     case actor_from_key_id(conn) do
-      %Actor{} = actor ->
+      {:ok, %Actor{} = actor} ->
         Logger.debug("Mapped identity to #{actor.url} from signed fetch")
         assign(conn, :actor, actor)
 
-      _ ->
+      {:error, :no_key_in_conn} ->
+        Logger.debug("There was no key in conn")
+        assign(conn, :valid_signature, false)
+
+      {:error, :actor_not_found} ->
         Logger.debug("Failed to map identity from signature (no payload actor mismatch)")
         Logger.debug("key_id=#{key_id_from_conn(conn)}")
         assign(conn, :valid_signature, false)