add license boilerplate to pleroma core

[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 9c1d717481d2ec7dde07ad50d3e87e515a878673..a61726b3efc384dfeb288b22b46f905a16ed2e76 100644 (file)
--- a/lib/pleroma/web/media_proxy/media_proxy.ex
+++ b/lib/pleroma/web/media_proxy/media_proxy.ex
@@ -1,23 +1,43 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2018 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
 defmodule Pleroma.Web.MediaProxy do
   @base64_opts [padding: false]
-  @base64_key Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
 
   def url(nil), do: nil
 
+  def url(""), do: nil
+
+  def url(url = "/" <> _), do: url
+
   def url(url) do
-    if String.starts_with?(url, Pleroma.Web.base_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
       url
     else
-      base64 = Base.url_encode64(url, @base64_opts)
-      sig = :crypto.hmac(:sha, @base64_key, base64)
+      secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
+
+      # The URL is url-decoded and encoded again to ensure it is correctly encoded and not twice.
+      base64 =
+        url
+        |> URI.decode()
+        |> URI.encode()
+        |> Base.url_encode64(@base64_opts)
+
+      sig = :crypto.hmac(:sha, secret, base64)
       sig64 = sig |> Base.url_encode64(@base64_opts)
-      cache_url("#{sig64}/#{base64}")
+
+      build_url(sig64, base64, filename(url))
     end
   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, @base64_key, url)
+    local_sig = :crypto.hmac(:sha, secret, url)
+
     if local_sig == sig do
       {:ok, Base.url_decode64!(url, @base64_opts)}
     else
@@ -25,9 +45,19 @@ defmodule Pleroma.Web.MediaProxy do
     end
   end
 
-  defp cache_url(path) do
-    "/proxy/" <> path
+  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