Merge branch 'bugfix/html-scrub-comments' into 'develop'

[akkoma] / lib / pleroma / html.ex

diff --git a/lib/pleroma/html.ex b/lib/pleroma/html.ex
index 0ec73a91d39c3763e34f8cb98c8af7203b22ec3a..a7338eac3681b6bd4804cf32674d57f5865da1cc 100644 (file)
--- a/lib/pleroma/html.ex
+++ b/lib/pleroma/html.ex
@@ -3,12 +3,183 @@ defmodule Pleroma.HTML do
 
   @markup Application.get_env(:pleroma, :markup)
 
-  def filter_tags(html) do
-    scrubber = Keyword.get(@markup, :scrub_policy)
+  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
+    Keyword.get(@markup, :scrub_policy)
+    |> get_scrubbers
+  end
+
+  def filter_tags(html, nil) do
+    get_scrubbers()
+    |> Enum.reduce(html, fn scrubber, html ->
+      filter_tags(html, scrubber)
+    end)
+  end
+
+  def filter_tags(html, scrubber) do
     html |> Scrubber.scrub(scrubber)
   end
 
+  def filter_tags(html), do: filter_tags(html, nil)
+
   def strip_tags(html) do
     html |> Scrubber.scrub(Scrubber.StripTags)
   end
 end
+
+defmodule Pleroma.HTML.Scrubber.TwitterText do
+  @moduledoc """
+  An HTML scrubbing policy which limits to twitter-style text.  Only
+  paragraphs, breaks and links are allowed through the filter.
+  """
+
+  @markup Application.get_env(:pleroma, :markup)
+  @uri_schemes Application.get_env(:pleroma, :uri_schemes, [])
+  @valid_schemes Keyword.get(@uri_schemes, :valid_schemes, [])
+
+  require HtmlSanitizeEx.Scrubber.Meta
+  alias HtmlSanitizeEx.Scrubber.Meta
+
+  Meta.remove_cdata_sections_before_scrub()
+  Meta.strip_comments()
+
+  # links
+  Meta.allow_tag_with_uri_attributes("a", ["href"], @valid_schemes)
+  Meta.allow_tag_with_these_attributes("a", ["name", "title"])
+
+  # paragraphs and linebreaks
+  Meta.allow_tag_with_these_attributes("br", [])
+  Meta.allow_tag_with_these_attributes("p", [])
+
+  # microformats
+  Meta.allow_tag_with_these_attributes("span", [])
+
+  # allow inline images for custom emoji
+  @allow_inline_images Keyword.get(@markup, :allow_inline_images)
+
+  if @allow_inline_images do
+    # restrict img tags to http/https only, because of MediaProxy.
+    Meta.allow_tag_with_uri_attributes("img", ["src"], ["http", "https"])
+
+    Meta.allow_tag_with_these_attributes("img", [
+      "width",
+      "height",
+      "title",
+      "alt"
+    ])
+  end
+
+  Meta.strip_everything_not_covered()
+end
+
+defmodule Pleroma.HTML.Scrubber.Default do
+  @doc "The default HTML scrubbing policy: no "
+
+  require HtmlSanitizeEx.Scrubber.Meta
+  alias HtmlSanitizeEx.Scrubber.Meta
+
+  @markup Application.get_env(:pleroma, :markup)
+  @uri_schemes Application.get_env(:pleroma, :uri_schemes, [])
+  @valid_schemes Keyword.get(@uri_schemes, :valid_schemes, [])
+
+  Meta.remove_cdata_sections_before_scrub()
+  Meta.strip_comments()
+
+  Meta.allow_tag_with_uri_attributes("a", ["href"], @valid_schemes)
+  Meta.allow_tag_with_these_attributes("a", ["name", "title"])
+
+  Meta.allow_tag_with_these_attributes("b", [])
+  Meta.allow_tag_with_these_attributes("blockquote", [])
+  Meta.allow_tag_with_these_attributes("br", [])
+  Meta.allow_tag_with_these_attributes("code", [])
+  Meta.allow_tag_with_these_attributes("del", [])
+  Meta.allow_tag_with_these_attributes("em", [])
+  Meta.allow_tag_with_these_attributes("i", [])
+  Meta.allow_tag_with_these_attributes("li", [])
+  Meta.allow_tag_with_these_attributes("ol", [])
+  Meta.allow_tag_with_these_attributes("p", [])
+  Meta.allow_tag_with_these_attributes("pre", [])
+  Meta.allow_tag_with_these_attributes("span", [])
+  Meta.allow_tag_with_these_attributes("strong", [])
+  Meta.allow_tag_with_these_attributes("u", [])
+  Meta.allow_tag_with_these_attributes("ul", [])
+
+  @allow_inline_images Keyword.get(@markup, :allow_inline_images)
+
+  if @allow_inline_images do
+    # restrict img tags to http/https only, because of MediaProxy.
+    Meta.allow_tag_with_uri_attributes("img", ["src"], ["http", "https"])
+
+    Meta.allow_tag_with_these_attributes("img", [
+      "width",
+      "height",
+      "title",
+      "alt"
+    ])
+  end
+
+  @allow_tables Keyword.get(@markup, :allow_tables)
+
+  if @allow_tables do
+    Meta.allow_tag_with_these_attributes("table", [])
+    Meta.allow_tag_with_these_attributes("tbody", [])
+    Meta.allow_tag_with_these_attributes("td", [])
+    Meta.allow_tag_with_these_attributes("th", [])
+    Meta.allow_tag_with_these_attributes("thead", [])
+    Meta.allow_tag_with_these_attributes("tr", [])
+  end
+
+  @allow_headings Keyword.get(@markup, :allow_headings)
+
+  if @allow_headings do
+    Meta.allow_tag_with_these_attributes("h1", [])
+    Meta.allow_tag_with_these_attributes("h2", [])
+    Meta.allow_tag_with_these_attributes("h3", [])
+    Meta.allow_tag_with_these_attributes("h4", [])
+    Meta.allow_tag_with_these_attributes("h5", [])
+  end
+
+  @allow_fonts Keyword.get(@markup, :allow_fonts)
+
+  if @allow_fonts do
+    Meta.allow_tag_with_these_attributes("font", ["face"])
+  end
+
+  Meta.strip_everything_not_covered()
+end
+
+defmodule Pleroma.HTML.Transform.MediaProxy do
+  @moduledoc "Transforms inline image URIs to use MediaProxy."
+
+  alias Pleroma.Web.MediaProxy
+
+  def before_scrub(html), do: html
+
+  def scrub_attribute("img", {"src", "http" <> target}) do
+    media_url =
+      ("http" <> target)
+      |> MediaProxy.url()
+
+    {"src", media_url}
+  end
+
+  def scrub_attribute(tag, attribute), do: attribute
+
+  def scrub({"img", attributes, children}) do
+    attributes =
+      attributes
+      |> Enum.map(fn attr -> scrub_attribute("img", attr) end)
+      |> Enum.reject(&is_nil(&1))
+
+    {"img", attributes, children}
+  end
+
+  def scrub({:comment, children}), do: ""
+
+  def scrub({tag, attributes, children}), do: {tag, attributes, children}
+  def scrub({tag, children}), do: children
+  def scrub(text), do: text
+end