Merge branch 'enable-ogp-by-default' into 'develop'

[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 6819c0917846674d84013f902541d98c6aa80150..dd8888a021635357b4fe88c1bb2748517c7c6062 100644 (file)
--- a/lib/pleroma/web/media_proxy/media_proxy.ex
+++ b/lib/pleroma/web/media_proxy/media_proxy.ex
@@ -1,29 +1,47 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
 defmodule Pleroma.Web.MediaProxy do
   @base64_opts [padding: false]
 
   def url(nil), do: nil
 
-  def url(url = "/" <> _), do: url
+  def url(""), do: nil
 
-  def url(url) do
-    config = Application.get_env(:pleroma, :media_proxy, [])
+  def url("/" <> _ = url), do: url
 
-    if !Keyword.get(config, :enabled, false) or String.starts_with?(url, Pleroma.Web.base_url()) do
+  def url(url) do
+    if !enabled?() or local?(url) or whitelisted?(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)
-      filename = Path.basename(url)
-
-      Keyword.get(config, :base_url, Pleroma.Web.base_url()) <>
-        "/proxy/#{sig64}/#{base64}/#{filename}"
+      encode_url(url)
     end
   end
 
+  defp enabled?, do: Pleroma.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)
+
+    Enum.any?(Pleroma.Config.get([:media_proxy, :whitelist]), fn pattern ->
+      String.equivalent?(domain, pattern)
+    end)
+  end
+
+  def encode_url(url) do
+    secret = Pleroma.Config.get([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)
+
+    build_url(sig64, base64, filename(url))
+  end
+
   def decode_url(sig, url) do
-    secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
+    secret = Pleroma.Config.get([Pleroma.Web.Endpoint, :secret_key_base])
     sig = Base.url_decode64!(sig, @base64_opts)
     local_sig = :crypto.hmac(:sha, secret, url)
 
@@ -33,4 +51,20 @@ defmodule Pleroma.Web.MediaProxy do
       {:error, :invalid_signature}
     end
   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], Pleroma.Web.base_url()),
+      "proxy",
+      sig_base64,
+      url_base64,
+      filename
+    ]
+    |> Enum.filter(fn value -> value end)
+    |> Path.join()
+  end
 end