# Pleroma: A lightweight social networking server
-# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# 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]
- 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 url(""), do: nil
+ 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 !enabled?() or local?(url) or whitelisted?(url) do
+ if not enabled?() or not url_proxiable?(url) do
url
else
encode_url(url)
end
end
- defp enabled?, do: Pleroma.Config.get([:media_proxy, :enabled], false)
+ @spec url_proxiable?(String.t()) :: boolean()
+ def url_proxiable?(url) do
+ if local?(url) or whitelisted?(url) do
+ false
+ else
+ true
+ end
+ end
- defp local?(url), do: String.starts_with?(url, Pleroma.Web.base_url())
+ # Note: routing all URLs to preview handler (even local and whitelisted).
+ # Preview handler will call url/1 on decoded URLs, and applicable ones will detour media proxy.
+ def preview_url(url) do
+ if preview_enabled?() do
+ encode_preview_url(url)
+ else
+ url
+ end
+ end
+
+ def enabled?, do: Config.get([:media_proxy, :enabled], false)
- defp whitelisted?(url) do
+ # Note: media proxy must be enabled for media preview proxy in order to load all
+ # non-local non-whitelisted URLs through it and be sure that body size constraint is preserved.
+ def preview_enabled?, do: enabled?() and Config.get([:media_preview_proxy, :enabled], false)
+
+ def local?(url), do: String.starts_with?(url, Pleroma.Web.base_url())
+
+ def whitelisted?(url) do
%{host: domain} = URI.parse(url)
- Enum.any?(Pleroma.Config.get([:media_proxy, :whitelist]), fn pattern ->
- String.equivalent?(domain, pattern)
- end)
+ 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
- def encode_url(url) do
- secret = Pleroma.Config.get([Pleroma.Web.Endpoint, :secret_key_base])
+ defp maybe_get_domain_from_url("http" <> _ = url) do
+ URI.parse(url).host
+ end
+
+ defp maybe_get_domain_from_url(domain), do: domain
+
+ defp base64_sig64(url) do
base64 = Base.url_encode64(url, @base64_opts)
- sig = :crypto.hmac(:sha, secret, base64)
- sig64 = sig |> Base.url_encode64(@base64_opts)
+
+ sig64 =
+ base64
+ |> signed_url()
+ |> Base.url_encode64(@base64_opts)
+
+ {base64, sig64}
+ end
+
+ def encode_url(url) do
+ {base64, sig64} = base64_sig64(url)
build_url(sig64, base64, filename(url))
end
- def decode_url(sig, url) do
- secret = Pleroma.Config.get([Pleroma.Web.Endpoint, :secret_key_base])
- sig = Base.url_decode64!(sig, @base64_opts)
- local_sig = :crypto.hmac(:sha, secret, url)
+ def encode_preview_url(url) do
+ {base64, sig64} = base64_sig64(url)
+
+ build_preview_url(sig64, base64, filename(url))
+ end
- if local_sig == sig do
+ def decode_url(sig, url) 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 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
+ defp proxy_url(path, sig_base64, url_base64, filename) do
[
- Pleroma.Config.get([:media_proxy, :base_url], Pleroma.Web.base_url()),
- "proxy",
+ Config.get([:media_proxy, :base_url], Web.base_url()),
+ path,
sig_base64,
url_base64,
filename
]
- |> Enum.filter(fn value -> value end)
+ |> Enum.filter(& &1)
|> Path.join()
end
+
+ def build_url(sig_base64, url_base64, filename \\ nil) do
+ proxy_url("proxy", sig_base64, url_base64, filename)
+ end
+
+ def build_preview_url(sig_base64, url_base64, filename \\ nil) do
+ proxy_url("proxy/preview", sig_base64, url_base64, filename)
+ end
+
+ def verify_request_path_and_url(
+ %Plug.Conn{params: %{"filename" => _}, request_path: request_path},
+ url
+ ) do
+ verify_request_path_and_url(request_path, url)
+ end
+
+ def verify_request_path_and_url(request_path, url) when is_binary(request_path) do
+ filename = filename(url)
+
+ if filename && not basename_matches?(request_path, filename) do
+ {:wrong_filename, filename}
+ else
+ :ok
+ end
+ end
+
+ def verify_request_path_and_url(_, _), do: :ok
+
+ defp basename_matches?(path, filename) do
+ basename = Path.basename(path)
+ basename == filename or URI.decode(basename) == filename or URI.encode(basename) == filename
+ end
end
projects / akkoma / blobdiff