# Pleroma: A lightweight social networking server # Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/> # SPDX-License-Identifier: AGPL-3.0-only defmodule Pleroma.HTML do # Scrubbers are compiled on boot so they can be configured in OTP releases # @on_load :compile_scrubbers def compile_scrubbers do dir = Path.join(:code.priv_dir(:pleroma), "scrubbers") dir |> Pleroma.Utils.compile_dir() |> case do {:error, _errors, _warnings} -> raise "Compiling scrubbers failed" {:ok, _modules, _warnings} -> :ok end end defp get_scrubbers(scrubber) when is_atom(scrubber), do: [scrubber] defp get_scrubbers(scrubbers) when is_list(scrubbers), do: scrubbers defp get_scrubbers(_), do: [Pleroma.HTML.Scrubber.Default] def get_scrubbers do Pleroma.Config.get([:markup, :scrub_policy]) |> get_scrubbers end def filter_tags(html, nil) do filter_tags(html, get_scrubbers()) end def filter_tags(html, scrubbers) when is_list(scrubbers) do Enum.reduce(scrubbers, html, fn scrubber, html -> filter_tags(html, scrubber) end) end def filter_tags(html, scrubber) do {:ok, content} = FastSanitize.Sanitizer.scrub(html, scrubber) content end def filter_tags(html), do: filter_tags(html, nil) def strip_tags(html), do: filter_tags(html, FastSanitize.Sanitizer.StripTags) def get_cached_scrubbed_html_for_activity( content, scrubbers, activity, key \\ "", callback \\ fn x -> x end ) do key = "#{key}#{generate_scrubber_signature(scrubbers)}|#{activity.id}" Cachex.fetch!(:scrubber_cache, key, fn _key -> object = Pleroma.Object.normalize(activity) ensure_scrubbed_html(content, scrubbers, object.data["fake"] || false, callback) end) end def get_cached_stripped_html_for_activity(content, activity, key) do get_cached_scrubbed_html_for_activity( content, FastSanitize.Sanitizer.StripTags, activity, key, &HtmlEntities.decode/1 ) end def ensure_scrubbed_html( content, scrubbers, fake, callback ) do content = content |> filter_tags(scrubbers) |> callback.() if fake do {:ignore, content} else {:commit, content} end end defp generate_scrubber_signature(scrubber) when is_atom(scrubber) do generate_scrubber_signature([scrubber]) end defp generate_scrubber_signature(scrubbers) do Enum.reduce(scrubbers, "", fn scrubber, signature -> "#{signature}#{to_string(scrubber)}" end) end def extract_first_external_url(_, nil), do: {:error, "No content"} def extract_first_external_url(object, content) do key = "URL|#{object.id}" Cachex.fetch!(:scrubber_cache, key, fn _key -> result = content |> Floki.parse_fragment!() |> Floki.filter_out("a.mention,a.hashtag,a.attachment,a[rel~=\"tag\"]") |> Floki.attribute("a", "href") |> Enum.at(0) {:commit, {:ok, result}} end) end end