HTML: Compile Scrubbers on boot

This makes it possible to configure their behavior on OTP releases.
This commit is contained in:
rinpatch 2019-12-08 19:42:40 +03:00
parent af5fef1f22
commit d6c89068f3
8 changed files with 231 additions and 214 deletions

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@ -1,3 +1,3 @@
[ [
inputs: ["mix.exs", "{config,lib,test}/**/*.{ex,exs}", "priv/repo/migrations/*.exs"] inputs: ["mix.exs", "{config,lib,test}/**/*.{ex,exs}", "priv/repo/migrations/*.exs", "priv/scrubbers/*.ex"]
] ]

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@ -82,6 +82,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
- Report emails now include functional links to profiles of remote user accounts - Report emails now include functional links to profiles of remote user accounts
- Not being able to log in to some third-party apps when logged in to MastoFE - Not being able to log in to some third-party apps when logged in to MastoFE
- MRF: `Delete` activities being exempt from MRF policies - MRF: `Delete` activities being exempt from MRF policies
- OTP releases: Not being able to configure HTML sanitization policy
<details> <details>
<summary>API Changes</summary> <summary>API Changes</summary>

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@ -30,6 +30,7 @@ def user_agent do
# See http://elixir-lang.org/docs/stable/elixir/Application.html # See http://elixir-lang.org/docs/stable/elixir/Application.html
# for more information on OTP Applications # for more information on OTP Applications
def start(_type, _args) do def start(_type, _args) do
Pleroma.HTML.compile_scrubbers()
Pleroma.Config.DeprecationWarnings.warn() Pleroma.Config.DeprecationWarnings.warn()
setup_instrumenters() setup_instrumenters()

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@ -3,6 +3,25 @@
# SPDX-License-Identifier: AGPL-3.0-only # SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.HTML do 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
|> File.ls!()
|> Enum.map(&Path.join(dir, &1))
|> Kernel.ParallelCompiler.compile()
|> 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(scrubber) when is_atom(scrubber), do: [scrubber]
defp get_scrubbers(scrubbers) when is_list(scrubbers), do: scrubbers defp get_scrubbers(scrubbers) when is_list(scrubbers), do: scrubbers
defp get_scrubbers(_), do: [Pleroma.HTML.Scrubber.Default] defp get_scrubbers(_), do: [Pleroma.HTML.Scrubber.Default]
@ -99,216 +118,3 @@ def extract_first_external_url(object, content) do
end) end)
end end
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.
"""
@valid_schemes Pleroma.Config.get([:uri_schemes, :valid_schemes], [])
require FastSanitize.Sanitizer.Meta
alias FastSanitize.Sanitizer.Meta
Meta.strip_comments()
# links
Meta.allow_tag_with_uri_attributes(:a, ["href", "data-user", "data-tag"], @valid_schemes)
Meta.allow_tag_with_this_attribute_values(:a, "class", [
"hashtag",
"u-url",
"mention",
"u-url mention",
"mention u-url"
])
Meta.allow_tag_with_this_attribute_values(:a, "rel", [
"tag",
"nofollow",
"noopener",
"noreferrer"
])
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_this_attribute_values(:span, "class", ["h-card"])
Meta.allow_tag_with_these_attributes(:span, [])
# allow inline images for custom emoji
if Pleroma.Config.get([:markup, :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",
"class",
"title",
"alt"
])
end
Meta.strip_everything_not_covered()
end
defmodule Pleroma.HTML.Scrubber.Default do
@doc "The default HTML scrubbing policy: no "
require FastSanitize.Sanitizer.Meta
alias FastSanitize.Sanitizer.Meta
# credo:disable-for-previous-line
# No idea how to fix this one…
@valid_schemes Pleroma.Config.get([:uri_schemes, :valid_schemes], [])
Meta.strip_comments()
Meta.allow_tag_with_uri_attributes(:a, ["href", "data-user", "data-tag"], @valid_schemes)
Meta.allow_tag_with_this_attribute_values(:a, "class", [
"hashtag",
"u-url",
"mention",
"u-url mention",
"mention u-url"
])
Meta.allow_tag_with_this_attribute_values(:a, "rel", [
"tag",
"nofollow",
"noopener",
"noreferrer",
"ugc"
])
Meta.allow_tag_with_these_attributes(:a, ["name", "title"])
Meta.allow_tag_with_these_attributes(:abbr, ["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(:strong, [])
Meta.allow_tag_with_these_attributes(:sub, [])
Meta.allow_tag_with_these_attributes(:sup, [])
Meta.allow_tag_with_these_attributes(:u, [])
Meta.allow_tag_with_these_attributes(:ul, [])
Meta.allow_tag_with_this_attribute_values(:span, "class", ["h-card"])
Meta.allow_tag_with_these_attributes(:span, [])
@allow_inline_images Pleroma.Config.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",
"class",
"title",
"alt"
])
end
if Pleroma.Config.get([:markup, :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
if Pleroma.Config.get([:markup, :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
if Pleroma.Config.get([:markup, :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, _text, _children}), do: ""
def scrub({tag, attributes, children}), do: {tag, attributes, children}
def scrub({_tag, children}), do: children
def scrub(text), do: text
end
defmodule Pleroma.HTML.Scrubber.LinksOnly do
@moduledoc """
An HTML scrubbing policy which limits to links only.
"""
@valid_schemes Pleroma.Config.get([:uri_schemes, :valid_schemes], [])
require FastSanitize.Sanitizer.Meta
alias FastSanitize.Sanitizer.Meta
Meta.strip_comments()
# links
Meta.allow_tag_with_uri_attributes(:a, ["href"], @valid_schemes)
Meta.allow_tag_with_this_attribute_values(:a, "rel", [
"tag",
"nofollow",
"noopener",
"noreferrer",
"me",
"ugc"
])
Meta.allow_tag_with_these_attributes(:a, ["name", "title"])
Meta.strip_everything_not_covered()
end

93
priv/scrubbers/default.ex Normal file
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@ -0,0 +1,93 @@
defmodule Pleroma.HTML.Scrubber.Default do
@doc "The default HTML scrubbing policy: no "
require FastSanitize.Sanitizer.Meta
alias FastSanitize.Sanitizer.Meta
# credo:disable-for-previous-line
# No idea how to fix this one…
@valid_schemes Pleroma.Config.get([:uri_schemes, :valid_schemes], [])
Meta.strip_comments()
Meta.allow_tag_with_uri_attributes(:a, ["href", "data-user", "data-tag"], @valid_schemes)
Meta.allow_tag_with_this_attribute_values(:a, "class", [
"hashtag",
"u-url",
"mention",
"u-url mention",
"mention u-url"
])
Meta.allow_tag_with_this_attribute_values(:a, "rel", [
"tag",
"nofollow",
"noopener",
"noreferrer",
"ugc"
])
Meta.allow_tag_with_these_attributes(:a, ["name", "title"])
Meta.allow_tag_with_these_attributes(:abbr, ["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(:strong, [])
Meta.allow_tag_with_these_attributes(:sub, [])
Meta.allow_tag_with_these_attributes(:sup, [])
Meta.allow_tag_with_these_attributes(:u, [])
Meta.allow_tag_with_these_attributes(:ul, [])
Meta.allow_tag_with_this_attribute_values(:span, "class", ["h-card"])
Meta.allow_tag_with_these_attributes(:span, [])
@allow_inline_images Pleroma.Config.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",
"class",
"title",
"alt"
])
end
if Pleroma.Config.get([:markup, :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
if Pleroma.Config.get([:markup, :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
if Pleroma.Config.get([:markup, :allow_fonts]) do
Meta.allow_tag_with_these_attributes(:font, ["face"])
end
Meta.strip_everything_not_covered()
end

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@ -0,0 +1,27 @@
defmodule Pleroma.HTML.Scrubber.LinksOnly do
@moduledoc """
An HTML scrubbing policy which limits to links only.
"""
@valid_schemes Pleroma.Config.get([:uri_schemes, :valid_schemes], [])
require FastSanitize.Sanitizer.Meta
alias FastSanitize.Sanitizer.Meta
Meta.strip_comments()
# links
Meta.allow_tag_with_uri_attributes(:a, ["href"], @valid_schemes)
Meta.allow_tag_with_this_attribute_values(:a, "rel", [
"tag",
"nofollow",
"noopener",
"noreferrer",
"me",
"ugc"
])
Meta.allow_tag_with_these_attributes(:a, ["name", "title"])
Meta.strip_everything_not_covered()
end

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@ -0,0 +1,32 @@
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, _text, _children}), do: ""
def scrub({tag, attributes, children}), do: {tag, attributes, children}
def scrub({_tag, children}), do: children
def scrub(text), do: text
end

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@ -0,0 +1,57 @@
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.
"""
@valid_schemes Pleroma.Config.get([:uri_schemes, :valid_schemes], [])
require FastSanitize.Sanitizer.Meta
alias FastSanitize.Sanitizer.Meta
Meta.strip_comments()
# links
Meta.allow_tag_with_uri_attributes(:a, ["href", "data-user", "data-tag"], @valid_schemes)
Meta.allow_tag_with_this_attribute_values(:a, "class", [
"hashtag",
"u-url",
"mention",
"u-url mention",
"mention u-url"
])
Meta.allow_tag_with_this_attribute_values(:a, "rel", [
"tag",
"nofollow",
"noopener",
"noreferrer"
])
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_this_attribute_values(:span, "class", ["h-card"])
Meta.allow_tag_with_these_attributes(:span, [])
# allow inline images for custom emoji
if Pleroma.Config.get([:markup, :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",
"class",
"title",
"alt"
])
end
Meta.strip_everything_not_covered()
end