Merge remote-tracking branch 'remotes/origin/develop' into 2168-media-preview-proxy

[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 077fabe47bf6fbab92ff175dfe44269dcf4e9de8..1b6242cb4d0fa9fad178216094956d9f088145a9 100644 (file)
--- a/lib/pleroma/web/media_proxy/media_proxy.ex
+++ b/lib/pleroma/web/media_proxy/media_proxy.ex
@@ -37,7 +37,7 @@ defmodule Pleroma.Web.MediaProxy do
   def url("/" <> _ = url), do: url
 
   def url(url) do
-    if disabled?() or not url_proxiable?(url) do
+    if not enabled?() or not url_proxiable?(url) do
       url
     else
       encode_url(url)
@@ -53,11 +53,25 @@ defmodule Pleroma.Web.MediaProxy do
     end
   end
 
-  defp disabled?, do: !Config.get([:media_proxy, :enabled], false)
+  # 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
 
-  defp local?(url), do: String.starts_with?(url, Pleroma.Web.base_url())
+  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)
 
     mediaproxy_whitelist = Config.get([:media_proxy, :whitelist])
@@ -76,17 +90,29 @@ defmodule Pleroma.Web.MediaProxy do
     end)
   end
 
-  def encode_url(url) do
+  defp base64_sig64(url) do
     base64 = Base.url_encode64(url, @base64_opts)
 
     sig64 =
       base64
-      |> signed_url
+      |> 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 encode_preview_url(url) do
+    {base64, sig64} = base64_sig64(url)
+
+    build_preview_url(sig64, base64, filename(url))
+  end
+
   def decode_url(sig, url) do
     with {:ok, sig} <- Base.url_decode64(sig, @base64_opts),
          signature when signature == sig <- signed_url(url) do
@@ -104,10 +130,10 @@ defmodule Pleroma.Web.MediaProxy 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], Web.base_url()),
-      "proxy",
+      path,
       sig_base64,
       url_base64,
       filename
@@ -115,4 +141,36 @@ defmodule Pleroma.Web.MediaProxy do
     |> 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