From 41b8a76e969e97aef68e7be1f1cdadcb31ea9b1d Mon Sep 17 00:00:00 2001
From: Roger Braun <roger@rogerbraun.net>
Date: Thu, 9 Nov 2017 08:32:54 +0100
Subject: [PATCH] Re-fetch user data on salmon decode error.

---
 lib/pleroma/web/ostatus/ostatus.ex            |  5 ++-
 lib/pleroma/web/ostatus/ostatus_controller.ex | 21 +++++++++-
 test/web/ostatus/ostatus_controller_test.exs  | 41 ++++++++++++++++++-
 3 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/lib/pleroma/web/ostatus/ostatus.ex b/lib/pleroma/web/ostatus/ostatus.ex
index 308e206c5..b0d2dda5d 100644
--- a/lib/pleroma/web/ostatus/ostatus.ex
+++ b/lib/pleroma/web/ostatus/ostatus.ex
@@ -221,7 +221,7 @@ def insert_or_update_user(data) do
     Repo.insert(cs, on_conflict: :replace_all, conflict_target: :nickname)
   end
 
-  def make_user(uri) do
+  def make_user(uri, update \\ false) do
     with {:ok, info} <- gather_user_info(uri) do
       data = %{
         name: info["name"],
@@ -231,7 +231,8 @@ def make_user(uri) do
         avatar: info["avatar"],
         bio: info["bio"]
       }
-      with %User{} = user <- User.get_by_ap_id(data.ap_id) do
+      with false <- update,
+           %User{} = user <- User.get_by_ap_id(data.ap_id) do
         {:ok, user}
       else _e -> insert_or_update_user(data)
       end
diff --git a/lib/pleroma/web/ostatus/ostatus_controller.ex b/lib/pleroma/web/ostatus/ostatus_controller.ex
index 4e3fbb4f6..67688ace4 100644
--- a/lib/pleroma/web/ostatus/ostatus_controller.ex
+++ b/lib/pleroma/web/ostatus/ostatus_controller.ex
@@ -5,6 +5,7 @@ defmodule Pleroma.Web.OStatus.OStatusController do
   alias Pleroma.Web.OStatus.{FeedRepresenter, ActivityRepresenter}
   alias Pleroma.Repo
   alias Pleroma.Web.{OStatus, Federator}
+  alias Pleroma.Web.XML
   import Ecto.Query
 
   def feed_redirect(conn, %{"nickname" => nickname}) do
@@ -36,10 +37,26 @@ def feed(conn, %{"nickname" => nickname}) do
     |> send_resp(200, response)
   end
 
+  defp decode_or_retry(body) do
+    with {:ok, magic_key} <- Pleroma.Web.Salmon.fetch_magic_key(body),
+         {:ok, doc} <- Pleroma.Web.Salmon.decode_and_validate(magic_key, body) do
+      {:ok, doc}
+    else
+      _e ->
+        with [decoded | _] <- Pleroma.Web.Salmon.decode(body),
+             doc <- XML.parse_document(decoded),
+             uri when not is_nil(uri) <- XML.string_from_xpath("/entry/author[1]/uri", doc),
+             {:ok, user} <- Pleroma.Web.OStatus.make_user(uri, true),
+             {:ok, magic_key} <- Pleroma.Web.Salmon.fetch_magic_key(body),
+             {:ok, doc} <- Pleroma.Web.Salmon.decode_and_validate(magic_key, body) do
+          {:ok, doc}
+        end
+    end
+  end
+
   def salmon_incoming(conn, params) do
     {:ok, body, _conn} = read_body(conn)
-    {:ok, magic_key} = Pleroma.Web.Salmon.fetch_magic_key(body)
-    {:ok, doc} = Pleroma.Web.Salmon.decode_and_validate(magic_key, body)
+    {:ok, doc} = decode_or_retry(body)
 
     Federator.enqueue(:incoming_doc, doc)
 
diff --git a/test/web/ostatus/ostatus_controller_test.exs b/test/web/ostatus/ostatus_controller_test.exs
index 77bc202fe..20d17d41f 100644
--- a/test/web/ostatus/ostatus_controller_test.exs
+++ b/test/web/ostatus/ostatus_controller_test.exs
@@ -1,9 +1,41 @@
 defmodule Pleroma.Web.OStatus.OStatusControllerTest do
   use Pleroma.Web.ConnCase
   import Pleroma.Factory
-  alias Pleroma.User
+  alias Pleroma.{User, Repo}
   alias Pleroma.Web.OStatus.ActivityRepresenter
 
+  test "decodes a salmon", %{conn: conn} do
+    user = insert(:user)
+    salmon = File.read!("test/fixtures/salmon.xml")
+    conn = conn
+    |> put_req_header("content-type", "application/atom+xml")
+    |> post("/users/#{user.nickname}/salmon", salmon)
+
+    assert response(conn, 200)
+  end
+
+  test "decodes a salmon with a changed magic key", %{conn: conn} do
+    user = insert(:user)
+    salmon = File.read!("test/fixtures/salmon.xml")
+    conn = conn
+    |> put_req_header("content-type", "application/atom+xml")
+    |> post("/users/#{user.nickname}/salmon", salmon)
+
+    assert response(conn, 200)
+
+    # Set a wrong magic-key for a user so it has to refetch
+    salmon_user = User.get_by_ap_id("http://gs.example.org:4040/index.php/user/1")
+    info = salmon_user.info
+    |> Map.put("magic_key", "RSA.pu0s-halox4tu7wmES1FVSx6u-4wc0YrUFXcqWXZG4-27UmbCOpMQftRCldNRfyA-qLbz-eqiwrong1EwUvjsD4cYbAHNGHwTvDOyx5AKthQUP44ykPv7kjKGh3DWKySJvcs9tlUG87hlo7AvnMo9pwRS_Zz2CacQ-MKaXyDepk=.AQAB") # Wrong key
+    Repo.update(User.info_changeset(salmon_user, %{info: info}))
+
+    conn = build_conn()
+    |> put_req_header("content-type", "application/atom+xml")
+    |> post("/users/#{user.nickname}/salmon", salmon)
+
+    assert response(conn, 200)
+  end
+
   test "gets a feed", %{conn: conn} do
     note_activity = insert(:note_activity)
     user = User.get_cached_by_ap_id(note_activity.data["actor"])
@@ -42,3 +74,10 @@ test "gets an activity", %{conn: conn} do
     assert response(conn, 200)
   end
 end
+
+defmodule Pleroma.Web.OStatusMock do
+  import Pleroma.Factory
+  def handle_incoming(_doc) do
+    insert(:note_activity)
+  end
+end