debianize-mobilizon/lib/federation/activity_pub/fetcher.ex
Thomas Citharel 6f9db37ca3
Fix checking origin from a tombstone
When comparing an activity with their origin, only compare the ID
directly, as Tombstones don't have actors anymore

Signed-off-by: Thomas Citharel <tcit@tcit.fr>
2021-08-10 20:49:45 +02:00

158 lines
5.2 KiB
Elixir

defmodule Mobilizon.Federation.ActivityPub.Fetcher do
@moduledoc """
Module to handle direct URL ActivityPub fetches to remote content
If you need to first get cached data, see `Mobilizon.Federation.ActivityPub.fetch_object_from_url/2`
"""
require Logger
alias Mobilizon.Federation.HTTPSignatures.Signature
alias Mobilizon.Federation.ActivityPub.{Relay, Transmogrifier}
alias Mobilizon.Federation.ActivityStream.Converter.Actor, as: ActorConverter
alias Mobilizon.Service.ErrorReporting.Sentry
alias Mobilizon.Service.HTTP.ActivityPub, as: ActivityPubClient
import Mobilizon.Federation.ActivityPub.Utils,
only: [maybe_date_fetch: 2, sign_fetch: 4, origin_check?: 2]
@spec fetch(String.t(), Keyword.t()) :: {:ok, map()}
def fetch(url, options \\ []) do
on_behalf_of = Keyword.get(options, :on_behalf_of, Relay.get_actor())
with false <- address_invalid(url),
date <- Signature.generate_date_header(),
headers <-
[{:Accept, "application/activity+json"}]
|> maybe_date_fetch(date)
|> sign_fetch(on_behalf_of, url, date),
client <-
ActivityPubClient.client(headers: headers),
{:ok, %Tesla.Env{body: data, status: code}} when code in 200..299 <-
ActivityPubClient.get(client, url) do
{:ok, data}
else
{:ok, %Tesla.Env{status: 410}} ->
Logger.debug("Resource at #{url} is 410 Gone")
{:error, "Gone"}
{:ok, %Tesla.Env{status: 404}} ->
Logger.debug("Resource at #{url} is 404 Gone")
{:error, "Not found"}
{:ok, %Tesla.Env{} = res} ->
{:error, res}
{:error, err} ->
{:error, err}
end
end
@spec fetch_and_create(String.t(), Keyword.t()) :: {:ok, map(), struct()}
def fetch_and_create(url, options \\ []) do
with {:ok, data} when is_map(data) <- fetch(url, options),
{:origin_check, true} <- {:origin_check, origin_check?(url, data)},
params <- %{
"type" => "Create",
"to" => data["to"],
"cc" => data["cc"],
"actor" => data["actor"] || data["attributedTo"],
"attributedTo" => data["attributedTo"] || data["actor"],
"object" => data
} do
Transmogrifier.handle_incoming(params)
else
{:origin_check, false} ->
Logger.warn("Object origin check failed")
{:error, "Object origin check failed"}
# Returned content is not JSON
{:ok, data} when is_binary(data) ->
{:error, "Failed to parse content as JSON"}
{:error, err} ->
{:error, err}
end
end
@spec fetch_and_update(String.t(), Keyword.t()) :: {:ok, map(), struct()}
def fetch_and_update(url, options \\ []) do
with {:ok, data} when is_map(data) <- fetch(url, options),
{:origin_check, true} <- {:origin_check, origin_check(url, data)},
params <- %{
"type" => "Update",
"to" => data["to"],
"cc" => data["cc"],
"actor" => data["actor"] || data["attributedTo"],
"attributedTo" => data["attributedTo"] || data["actor"],
"object" => data
} do
Transmogrifier.handle_incoming(params)
else
{:origin_check, false} ->
{:error, "Object origin check failed"}
{:error, err} ->
{:error, err}
end
end
@doc """
Fetching a remote actor's information through its AP ID
"""
@spec fetch_and_prepare_actor_from_url(String.t()) :: {:ok, map()} | {:error, atom()} | any()
def fetch_and_prepare_actor_from_url(url) do
Logger.debug("Fetching and preparing actor from url")
Logger.debug(inspect(url))
res =
with {:ok, %{status: 200, body: body}} <-
Tesla.get(url,
headers: [{"Accept", "application/activity+json"}],
follow_redirect: true
),
:ok <- Logger.debug("response okay, now decoding json"),
{:ok, data} <- Jason.decode(body) do
Logger.debug("Got activity+json response at actor's endpoint, now converting data")
{:ok, ActorConverter.as_to_model_data(data)}
else
# Actor is gone, probably deleted
{:ok, %{status: 410}} ->
Logger.info("Response HTTP 410")
{:error, :actor_deleted}
{:ok, %Tesla.Env{}} ->
Logger.info("Non 200 HTTP Code")
{:error, :http_error}
{:error, e} ->
Logger.warn("Could not decode actor at fetch #{url}, #{inspect(e)}")
{:error, e}
e ->
Logger.warn("Could not decode actor at fetch #{url}, #{inspect(e)}")
{:error, e}
end
res
end
@spec origin_check(String.t(), map()) :: boolean()
defp origin_check(url, data) do
if origin_check?(url, data) do
true
else
Sentry.capture_message("Object origin check failed", extra: %{url: url, data: data})
Logger.debug("Object origin check failed between #{inspect(url)} and #{inspect(data)}")
false
end
end
@spec address_invalid(String.t()) :: false | {:error, :invalid_url}
defp address_invalid(address) do
with %URI{host: host, scheme: scheme} <- URI.parse(address),
true <- is_nil(host) or is_nil(scheme) do
{:error, :invalid_url}
end
end
end