+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
defmodule Pleroma.Web.MediaProxy do
+ alias Pleroma.Config
+ alias Pleroma.Upload
+ alias Pleroma.Web
+ alias Pleroma.Web.MediaProxy.Invalidation
+
@base64_opts [padding: false]
- @base64_key Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
- def url(nil), do: nil
+ @spec in_banned_urls(String.t()) :: boolean()
+ def in_banned_urls(url), do: elem(Cachex.exists?(:banned_urls_cache, url(url)), 1)
+
+ def remove_from_banned_urls(urls) when is_list(urls) do
+ Cachex.execute!(:banned_urls_cache, fn cache ->
+ Enum.each(Invalidation.prepare_urls(urls), &Cachex.del(cache, &1))
+ end)
+ end
+
+ def remove_from_banned_urls(url) when is_binary(url) do
+ Cachex.del(:banned_urls_cache, url(url))
+ end
+
+ def put_in_banned_urls(urls) when is_list(urls) do
+ Cachex.execute!(:banned_urls_cache, fn cache ->
+ Enum.each(Invalidation.prepare_urls(urls), &Cachex.put(cache, &1, true))
+ end)
+ end
+
+ def put_in_banned_urls(url) when is_binary(url) do
+ Cachex.put(:banned_urls_cache, url(url), true)
+ end
+
+ def url(url) when is_nil(url) or url == "", do: nil
+ def url("/" <> _ = url), do: url
def url(url) do
- if String.starts_with?(url, Pleroma.Web.base_url) do
+ if disabled?() or not url_proxiable?(url) do
url
else
- base64 = Base.url_encode64(url, @base64_opts)
- sig = :crypto.hmac(:sha, @base64_key, base64)
- sig64 = sig |> Base.url_encode64(@base64_opts)
- cache_url("#{sig64}/#{base64}")
+ encode_url(url)
+ end
+ end
+
+ @spec url_proxiable?(String.t()) :: boolean()
+ def url_proxiable?(url) do
+ if local?(url) or whitelisted?(url) do
+ false
+ else
+ true
end
end
+ defp disabled?, do: !Config.get([:media_proxy, :enabled], false)
+
+ defp local?(url), do: String.starts_with?(url, Pleroma.Web.base_url())
+
+ defp whitelisted?(url) do
+ %{host: domain} = URI.parse(url)
+
+ mediaproxy_whitelist_domains =
+ [:media_proxy, :whitelist]
+ |> Config.get()
+ |> Enum.map(&maybe_get_domain_from_url/1)
+
+ whitelist_domains =
+ if base_url = Config.get([Upload, :base_url]) do
+ %{host: base_domain} = URI.parse(base_url)
+ [base_domain | mediaproxy_whitelist_domains]
+ else
+ mediaproxy_whitelist_domains
+ end
+
+ domain in whitelist_domains
+ end
+
+ defp maybe_get_domain_from_url("http" <> _ = url) do
+ URI.parse(url).host
+ end
+
+ defp maybe_get_domain_from_url(domain), do: domain
+
+ def encode_url(url) do
+ base64 = Base.url_encode64(url, @base64_opts)
+
+ sig64 =
+ base64
+ |> signed_url
+ |> Base.url_encode64(@base64_opts)
+
+ build_url(sig64, base64, filename(url))
+ end
+
def decode_url(sig, url) do
- sig = Base.url_decode64!(sig, @base64_opts)
- local_sig = :crypto.hmac(:sha, @base64_key, url)
- if local_sig == sig do
+ with {:ok, sig} <- Base.url_decode64(sig, @base64_opts),
+ signature when signature == sig <- signed_url(url) do
{:ok, Base.url_decode64!(url, @base64_opts)}
else
- {:error, :invalid_signature}
+ _ -> {:error, :invalid_signature}
end
end
- defp cache_url(path) do
- "/proxy/" <> path
+ defp signed_url(url) do
+ :crypto.hmac(:sha, Config.get([Web.Endpoint, :secret_key_base]), url)
end
+ def filename(url_or_path) do
+ if path = URI.parse(url_or_path).path, do: Path.basename(path)
+ end
+ def build_url(sig_base64, url_base64, filename \\ nil) do
+ [
+ Config.get([:media_proxy, :base_url], Web.base_url()),
+ "proxy",
+ sig_base64,
+ url_base64,
+ filename
+ ]
+ |> Enum.filter(& &1)
+ |> Path.join()
+ end
end