akkoma/lib/pleroma/web/activity_pub/mrf.ex
floatingghost 31ad09010e Fix regex usage in MRF (#254)
fixes #235
fixes #228

Co-authored-by: FloatingGhost <hannah@coffee-and-dreams.uk>
Reviewed-on: https://akkoma.dev/AkkomaGang/akkoma/pulls/254
2022-11-06 23:50:32 +00:00

241 lines
7 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.ActivityPub.MRF do
require Logger
@behaviour Pleroma.Web.ActivityPub.MRF.PipelineFiltering
@mrf_config_descriptions [
%{
group: :pleroma,
key: :mrf,
tab: :mrf,
label: "MRF",
type: :group,
description: "General MRF settings",
children: [
%{
key: :policies,
type: [:module, {:list, :module}],
description:
"A list of MRF policies enabled. Module names are shortened (removed leading `Pleroma.Web.ActivityPub.MRF.` part), but on adding custom module you need to use full name.",
suggestions: {:list_behaviour_implementations, Pleroma.Web.ActivityPub.MRF.Policy}
},
%{
key: :transparency,
label: "MRF transparency",
type: :boolean,
description:
"Make the content of your Message Rewrite Facility settings public (via nodeinfo)"
},
%{
key: :transparency_exclusions,
label: "MRF transparency exclusions",
type: {:list, :tuple},
key_placeholder: "instance",
value_placeholder: "reason",
description:
"Exclude specific instance names from MRF transparency. The use of the exclusions feature will be disclosed in nodeinfo as a boolean value. You can also provide a reason for excluding these instance names. The instances and reasons won't be publicly disclosed.",
suggestions: [
"exclusion.com"
]
},
%{
key: :transparency_obfuscate_domains,
label: "MRF domain obfuscation",
type: {:list, :string},
description:
"Obfuscate domains in MRF transparency. This is useful if the domain you're blocking contains words you don't want displayed, but still want to disclose the MRF settings.",
suggestions: [
"badword.com"
]
}
]
}
]
@default_description %{
label: "",
description: ""
}
@required_description_keys [:key, :related_policy]
def filter_one(policy, message) do
should_plug_history? =
if function_exported?(policy, :history_awareness, 0) do
policy.history_awareness()
else
:manual
end
|> Kernel.==(:auto)
if not should_plug_history? do
policy.filter(message)
else
main_result = policy.filter(message)
with {_, {:ok, main_message}} <- {:main, main_result},
{_,
%{
"formerRepresentations" => %{
"orderedItems" => [_ | _]
}
}} = {_, object} <- {:object, message["object"]},
{_, {:ok, new_history}} <-
{:history,
Pleroma.Object.Updater.for_each_history_item(
object["formerRepresentations"],
object,
fn item ->
with {:ok, filtered} <- policy.filter(Map.put(message, "object", item)) do
{:ok, filtered["object"]}
else
e -> e
end
end
)} do
{:ok, put_in(main_message, ["object", "formerRepresentations"], new_history)}
else
{:main, _} -> main_result
{:object, _} -> main_result
{:history, e} -> e
end
end
end
def filter(policies, %{} = message) do
policies
|> Enum.reduce({:ok, message}, fn
policy, {:ok, message} -> filter_one(policy, message)
_, error -> error
end)
end
def filter(%{} = object), do: get_policies() |> filter(object)
@impl true
def pipeline_filter(%{} = message, meta) do
object = meta[:object_data]
ap_id = message["object"]
if object && ap_id do
with {:ok, message} <- filter(Map.put(message, "object", object)) do
meta = Keyword.put(meta, :object_data, message["object"])
{:ok, Map.put(message, "object", ap_id), meta}
else
{err, message} -> {err, message, meta}
end
else
{err, message} = filter(message)
{err, message, meta}
end
end
def get_policies do
Pleroma.Config.get([:mrf, :policies], [])
|> get_policies()
|> Enum.concat([
Pleroma.Web.ActivityPub.MRF.HashtagPolicy,
Pleroma.Web.ActivityPub.MRF.InlineQuotePolicy
])
|> Enum.uniq()
end
defp get_policies(policy) when is_atom(policy), do: [policy]
defp get_policies(policies) when is_list(policies), do: policies
defp get_policies(_), do: []
# Matches the following:
# - https://baddomain.net
# - https://extra.baddomain.net/
# Does NOT match the following:
# - https://maybebaddomain.net/
def subdomain_regex(domain) do
~r/^(.+\.)?#{Regex.escape(domain)}$/i
end
@spec subdomains_regex([String.t()]) :: [Regex.t()]
def subdomains_regex(domains) when is_list(domains) do
Enum.map(domains, &subdomain_regex/1)
end
@spec subdomain_match?([Regex.t()], String.t()) :: boolean()
def subdomain_match?(domains, host) do
Enum.any?(domains, fn domain -> Regex.match?(domain, host) end)
end
@spec instance_list_from_tuples([{String.t(), String.t()}]) :: [String.t()]
def instance_list_from_tuples(list) do
Enum.map(list, fn {instance, _} -> instance end)
end
def describe(policies) do
{:ok, policy_configs} =
policies
|> Enum.reduce({:ok, %{}}, fn
policy, {:ok, data} ->
{:ok, policy_data} = policy.describe()
{:ok, Map.merge(data, policy_data)}
_, error ->
error
end)
mrf_policies =
get_policies()
|> Enum.map(fn policy -> to_string(policy) |> String.split(".") |> List.last() end)
exclusions = Pleroma.Config.get([:mrf, :transparency_exclusions])
base =
%{
mrf_policies: mrf_policies,
exclusions: length(exclusions) > 0
}
|> Map.merge(policy_configs)
{:ok, base}
end
def describe, do: get_policies() |> describe()
def config_descriptions do
Pleroma.Web.ActivityPub.MRF.Policy
|> Pleroma.Docs.Generator.list_behaviour_implementations()
|> config_descriptions()
end
def config_descriptions(policies) do
Enum.reduce(policies, @mrf_config_descriptions, fn policy, acc ->
if function_exported?(policy, :config_description, 0) do
description =
@default_description
|> Map.merge(policy.config_description)
|> Map.put(:group, :pleroma)
|> Map.put(:tab, :mrf)
|> Map.put(:type, :group)
if Enum.all?(@required_description_keys, &Map.has_key?(description, &1)) do
[description | acc]
else
Logger.warn(
"#{policy} config description doesn't have one or all required keys #{inspect(@required_description_keys)}"
)
acc
end
else
Logger.debug(
"#{policy} is excluded from config descriptions, because does not implement `config_description/0` method."
)
acc
end
end)
end
end