1 files changed, 41 insertions, 0 deletions
diff --git a/lib/pleroma/plugs/oauth_scopes_plug.ex b/lib/pleroma/plugs/oauth_scopes_plug.ex
new file mode 100644
index 000000000..f2bfa2b1a
--- /dev/null
+++ b/lib/pleroma/plugs/oauth_scopes_plug.ex
@@ -0,0 +1,41 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Plugs.OAuthScopesPlug do
+  import Plug.Conn
+
+  @behaviour Plug
+
+  def init(%{scopes: _} = options), do: options
+
+  def call(%Plug.Conn{assigns: assigns} = conn, %{scopes: scopes} = options) do
+    op = options[:op] || :|
+    token = assigns[:token]
+
+    cond do
+      is_nil(token) ->
+        conn
+
+      op == :| && scopes -- token.scopes != scopes ->
+        conn
+
+      op == :& && scopes -- token.scopes == [] ->
+        conn
+
+      options[:fallback] == :proceed_unauthenticated ->
+        conn
+        |> assign(:user, nil)
+        |> assign(:token, nil)
+
+      true ->
+        missing_scopes = scopes -- token.scopes
+        error_message = "Insufficient permissions: #{Enum.join(missing_scopes, " #{op} ")}."
+
+        conn
+        |> put_resp_content_type("application/json")
+        |> send_resp(403, Jason.encode!(%{error: error_message}))
+        |> halt()
+    end
+  end
+end