Merge branch 'develop' into activation-meta

[akkoma] / lib / pleroma / web / media_proxy / media_proxy.ex

diff --git a/lib/pleroma/web/media_proxy/media_proxy.ex b/lib/pleroma/web/media_proxy/media_proxy.ex
index 21ebdfbbc13fcb2a51c3c05deed89714891b6fbc..077fabe47bf6fbab92ff175dfe44269dcf4e9de8 100644 (file)
--- a/lib/pleroma/web/media_proxy/media_proxy.ex
+++ b/lib/pleroma/web/media_proxy/media_proxy.ex
@@ -1,30 +1,118 @@
+# 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]
 
-  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
-    config = Application.get_env(:pleroma, :media_proxy, [])
-    if !Keyword.get(config, :enabled, false) or String.starts_with?(url, Pleroma.Web.base_url) do
+    if disabled?() or not url_proxiable?(url) do
       url
     else
-      secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
-      base64 = Base.url_encode64(url, @base64_opts)
-      sig = :crypto.hmac(:sha, secret, base64)
-      sig64 = sig |> Base.url_encode64(@base64_opts)
-      Keyword.get(config, :base_url, Pleroma.Web.base_url) <> "/proxy/#{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 = Config.get([:media_proxy, :whitelist])
+
+    upload_base_url_domain =
+      if !is_nil(Config.get([Upload, :base_url])) do
+        [URI.parse(Config.get([Upload, :base_url])).host]
+      else
+        []
+      end
+
+    whitelist = mediaproxy_whitelist ++ upload_base_url_domain
+
+    Enum.any?(whitelist, fn pattern ->
+      String.equivalent?(domain, pattern)
+    end)
+  end
+
+  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
-    secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
-    sig = Base.url_decode64!(sig, @base64_opts)
-    local_sig = :crypto.hmac(:sha, secret, 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 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
+    [
+      Pleroma.Config.get([:media_proxy, :base_url], Web.base_url()),
+      "proxy",
+      sig_base64,
+      url_base64,
+      filename
+    ]
+    |> Enum.filter(& &1)
+    |> Path.join()
+  end
 end