From 2c9465cc51160546ae054d1a1912fbb8e9add8e8 Mon Sep 17 00:00:00 2001
From: lain <lain@soykaf.club>
Date: Sat, 30 May 2020 12:17:18 +0200
Subject: [PATCH] SafeText: Let through basic html.

---
 .../object_validators/types/safe_text.ex           |  2 +-
 test/web/activity_pub/object_validator_test.exs    | 14 ++++++++++++++
 .../object_validators/types/safe_text_test.exs     |  7 +++++++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/lib/pleroma/web/activity_pub/object_validators/types/safe_text.ex b/lib/pleroma/web/activity_pub/object_validators/types/safe_text.ex
index 822e8d2c1..95c948123 100644
--- a/lib/pleroma/web/activity_pub/object_validators/types/safe_text.ex
+++ b/lib/pleroma/web/activity_pub/object_validators/types/safe_text.ex
@@ -10,7 +10,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.Types.SafeText do
   def type, do: :string
 
   def cast(str) when is_binary(str) do
-    {:ok, HTML.strip_tags(str)}
+    {:ok, HTML.filter_tags(str)}
   end
 
   def cast(_), do: :error
diff --git a/test/web/activity_pub/object_validator_test.exs b/test/web/activity_pub/object_validator_test.exs
index 929fdbc9b..31224abe0 100644
--- a/test/web/activity_pub/object_validator_test.exs
+++ b/test/web/activity_pub/object_validator_test.exs
@@ -113,6 +113,20 @@ test "it is invalid if the object data has a different `to` or `actor` field" do
       %{user: user, recipient: recipient, valid_chat_message: valid_chat_message}
     end
 
+    test "let's through some basic html", %{user: user, recipient: recipient} do
+      {:ok, valid_chat_message, _} =
+        Builder.chat_message(
+          user,
+          recipient.ap_id,
+          "hey <a href='https://example.org'>example</a> <script>alert('uguu')</script>"
+        )
+
+      assert {:ok, object, _meta} = ObjectValidator.validate(valid_chat_message, [])
+
+      assert object["content"] ==
+               "hey <a href=\"https://example.org\">example</a> alert(&#39;uguu&#39;)"
+    end
+
     test "validates for a basic object we build", %{valid_chat_message: valid_chat_message} do
       assert {:ok, object, _meta} = ObjectValidator.validate(valid_chat_message, [])
 
diff --git a/test/web/activity_pub/object_validators/types/safe_text_test.exs b/test/web/activity_pub/object_validators/types/safe_text_test.exs
index 59ed0a1fe..d4a574554 100644
--- a/test/web/activity_pub/object_validators/types/safe_text_test.exs
+++ b/test/web/activity_pub/object_validators/types/safe_text_test.exs
@@ -17,6 +17,13 @@ test "it removes html tags from text" do
     assert {:ok, "hey look xss alert(&#39;foo&#39;)"} == SafeText.cast(text)
   end
 
+  test "it keeps basic html tags" do
+    text = "hey <a href='http://gensokyo.2hu'>look</a> xss <script>alert('foo')</script>"
+
+    assert {:ok, "hey <a href=\"http://gensokyo.2hu\">look</a> xss alert(&#39;foo&#39;)"} ==
+             SafeText.cast(text)
+  end
+
   test "errors for non-text" do
     assert :error == SafeText.cast(1)
   end