Add Signed Fetch Statistics (#312)

[akkoma] / lib / pleroma / web / plugs / http_signature_plug.ex

diff --git a/lib/pleroma/web/plugs/http_signature_plug.ex b/lib/pleroma/web/plugs/http_signature_plug.ex
index c906a4eecaee47ffbc4d4fa38f47afb129ea8cbe..5ed3235e2e32985c4d0b736326d185396160dc08 100644 (file)
--- a/lib/pleroma/web/plugs/http_signature_plug.ex
+++ b/lib/pleroma/web/plugs/http_signature_plug.ex
@@ -7,8 +7,12 @@ defmodule Pleroma.Web.Plugs.HTTPSignaturePlug do
   import Phoenix.Controller, only: [get_format: 1, text: 2]
   alias Pleroma.Activity
   alias Pleroma.Web.Router
+  alias Pleroma.Signature
+  alias Pleroma.Instances
   require Logger
 
+  @cachex Pleroma.Config.get([:cachex, :provider], Cachex)
+
   def init(options) do
     options
   end
@@ -57,6 +61,7 @@ defmodule Pleroma.Web.Plugs.HTTPSignaturePlug do
 
     conn
     |> assign(:valid_signature, HTTPSignatures.validate_conn(conn))
+    |> assign(:signature_actor_id, signature_host(conn))
     |> assign_valid_signature_on_route_aliases(rest)
   end
 
@@ -78,6 +83,36 @@ defmodule Pleroma.Web.Plugs.HTTPSignaturePlug do
     conn |> get_req_header("signature") |> Enum.at(0, false)
   end
 
+  defp maybe_require_signature(
+         %{assigns: %{valid_signature: true, signature_actor_id: actor_id}} = conn
+       ) do
+    # inboxes implicitly need http signatures for authentication
+    # so we don't really know if the instance will have broken federation after
+    # we turn on authorized_fetch_mode.
+    #
+    # to "check" this is a signed fetch, verify if method is GET
+    if conn.method == "GET" do
+      actor_host = URI.parse(actor_id).host
+
+      case @cachex.get(:request_signatures_cache, actor_host) do
+        {:ok, nil} ->
+          Logger.debug("Successful signature from #{actor_host}")
+          Instances.set_request_signatures(actor_host)
+          @cachex.put(:request_signatures_cache, actor_host, true)
+
+        {:ok, true} ->
+          :noop
+
+        any ->
+          Logger.warn(
+            "expected request signature cache to return a boolean, instead got #{inspect(any)}"
+          )
+      end
+    end
+
+    conn
+  end
+
   defp maybe_require_signature(%{assigns: %{valid_signature: true}} = conn), do: conn
 
   defp maybe_require_signature(conn) do
@@ -90,4 +125,14 @@ defmodule Pleroma.Web.Plugs.HTTPSignaturePlug do
       conn
     end
   end
+
+  defp signature_host(conn) do
+    with %{"keyId" => kid} <- HTTPSignatures.signature_for_conn(conn),
+         {:ok, actor_id} <- Signature.key_id_to_actor_id(kid) do
+      actor_id
+    else
+      e ->
+        {:error, e}
+    end
+  end
 end