akkoma/lib/pleroma/web/metadata/utils.ex
Floatingghost 05f8179d08 check if data is visible before embedding it in OG tags
previously we would uncritically take data and format it into
tags for static-fe and the like - however, instances can be
configured to disallow unauthenticated access to these resources.

this means that OG tags as a vector for information leakage.

_technically_ this should only occur if you have both
restrict_unauthenticated *AND* you run static-fe, which makes no
sense since static-fe is for unauthenticated people in particular,
but hey ho.
2024-04-12 05:16:47 +01:00

80 lines
2.2 KiB
Elixir

# Pleroma: A lightweight social networking server
# Copyright © 2017-2021 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.Web.Metadata.Utils do
alias Pleroma.Activity
alias Pleroma.Emoji
alias Pleroma.Formatter
alias Pleroma.HTML
alias Pleroma.Web.ActivityPub.Visibility
def visible?(%Pleroma.User{} = object) do
Visibility.restrict_unauthenticated_access?(object) == :visible
end
def visible?(object) do
Visibility.visible_for_user?(object, nil)
end
defp scrub_html_and_truncate_object_field(field, object) do
field
# html content comes from DB already encoded, decode first and scrub after
|> HtmlEntities.decode()
|> String.replace(~r/<br\s?\/?>/, " ")
|> Activity.HTML.get_cached_stripped_html_for_activity(object, "metadata")
|> Emoji.Formatter.demojify()
|> HtmlEntities.decode()
|> Formatter.truncate()
end
def scrub_html_and_truncate(%{data: %{"summary" => summary}} = object)
when is_binary(summary) and summary != "" do
summary
|> scrub_html_and_truncate_object_field(object)
end
def scrub_html_and_truncate(%{data: %{"content" => content}} = object) do
content
|> scrub_html_and_truncate_object_field(object)
end
def scrub_html_and_truncate(%{data: _}) do
""
end
def scrub_html_and_truncate(content, max_length \\ 200) when is_binary(content) do
content
|> scrub_html
|> Emoji.Formatter.demojify()
|> HtmlEntities.decode()
|> Formatter.truncate(max_length)
end
def scrub_html(content) when is_binary(content) do
content
# html content comes from DB already encoded, decode first and scrub after
|> HtmlEntities.decode()
|> String.replace(~r/<br\s?\/?>/, " ")
|> HTML.strip_tags()
end
def scrub_html(content), do: content
def user_name_string(user) do
"#{user.name} " <>
if user.local do
"(@#{user.nickname}@#{Pleroma.Web.WebFinger.domain()})"
else
"(@#{user.nickname})"
end
end
@spec fetch_media_type(list(String.t()), String.t()) :: String.t() | nil
def fetch_media_type(supported_types, media_type) do
Enum.find(supported_types, fn support_type ->
String.starts_with?(media_type, support_type)
end)
end
end