Merge branch 'feature/jobs' 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 21ebdfbbc13fcb2a51c3c05deed89714891b6fbc..39a725a6941c86c61ae69d18657772ad7fb61c43 100644 (file)
--- a/lib/pleroma/web/media_proxy/media_proxy.ex
+++ b/lib/pleroma/web/media_proxy/media_proxy.ex
@@ -1,18 +1,40 @@
+# 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(""), 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 !Keyword.get(config, :enabled, false) or String.starts_with?(url, Pleroma.Web.base_url()) do
       url
     else
       secret = Application.get_env(:pleroma, Pleroma.Web.Endpoint)[:secret_key_base]
-      base64 = Base.url_encode64(url, @base64_opts)
+
+      # Must preserve `%2F` for compatibility with S3 (https://git.pleroma.social/pleroma/pleroma/issues/580)
+      replacement = get_replacement(url, ":2F:")
+
+      # The URL is url-decoded and encoded again to ensure it is correctly encoded and not twice.
+      base64 =
+        url
+        |> String.replace("%2F", replacement)
+        |> URI.decode()
+        |> URI.encode()
+        |> String.replace(replacement, "%2F")
+        |> Base.url_encode64(@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}"
+
+      build_url(sig64, base64, filename(url))
     end
   end
 
@@ -20,6 +42,7 @@ defmodule Pleroma.Web.MediaProxy 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
       {:ok, Base.url_decode64!(url, @base64_opts)}
     else
@@ -27,4 +50,27 @@ defmodule Pleroma.Web.MediaProxy do
     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
+
+  defp get_replacement(url, replacement) do
+    if String.contains?(url, replacement) do
+      get_replacement(url, replacement <> replacement)
+    else
+      replacement
+    end
+  end
 end