Merge branch 'fix/csp-for-captcha' into 'develop'

Add Captcha endpoint to CSP headers when MediaProxy is enabled.

See merge request pleroma/pleroma!2718

CHANGELOG.md

@@ -81,6 +81,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - `blob:` urls not being allowed by connect-src CSP
 - Mastodon API: fix `GET /api/v1/notifications` not returning the full result set
 - Rich Media Previews for Twitter links
+- Fix CSP policy generation to include remote Captcha services
 
 ## [Unreleased (patch)]
 

lib/pleroma/plugs/http_security_plug.ex

@@ -69,10 +69,11 @@ defp csp_string do
     img_src = "img-src 'self' data: blob:"
     media_src = "media-src 'self'"
 
+    # Strict multimedia CSP enforcement only when MediaProxy is enabled
     {img_src, media_src} =
       if Config.get([:media_proxy, :enabled]) &&
            !Config.get([:media_proxy, :proxy_opts, :redirect_on_failure]) do
-        sources = get_proxy_and_attachment_sources()
+        sources = build_csp_multimedia_source_list()
         {[img_src, sources], [media_src, sources]}
       else
         {[img_src, " https:"], [media_src, " https:"]}
@@ -107,29 +108,28 @@ defp csp_string do
     |> :erlang.iolist_to_binary()
   end
 
-  defp get_proxy_and_attachment_sources do
+  defp build_csp_multimedia_source_list do
     media_proxy_whitelist =
       Enum.reduce(Config.get([:media_proxy, :whitelist]), [], fn host, acc ->
         add_source(acc, host)
       end)
 
-    media_proxy_base_url =
-      if Config.get([:media_proxy, :base_url]),
-        do: URI.parse(Config.get([:media_proxy, :base_url])).host
+    media_proxy_base_url = build_csp_param(Config.get([:media_proxy, :base_url]))
 
-    upload_base_url =
-      if Config.get([Pleroma.Upload, :base_url]),
-        do: URI.parse(Config.get([Pleroma.Upload, :base_url])).host
+    upload_base_url = build_csp_param(Config.get([Pleroma.Upload, :base_url]))
 
-    s3_endpoint =
-      if Config.get([Pleroma.Upload, :uploader]) == Pleroma.Uploaders.S3,
-        do: URI.parse(Config.get([Pleroma.Uploaders.S3, :public_endpoint])).host
+    s3_endpoint = build_csp_param(Config.get([Pleroma.Uploaders.S3, :public_endpoint]))
+
+    captcha_method = Config.get([Pleroma.Captcha, :method])
+
+    captcha_endpoint = build_csp_param(Config.get([captcha_method, :endpoint]))
 
     []
     |> add_source(media_proxy_base_url)
     |> add_source(upload_base_url)
     |> add_source(s3_endpoint)
     |> add_source(media_proxy_whitelist)
+    |> add_source(captcha_endpoint)
   end
 
   defp add_source(iodata, nil), do: iodata
@@ -139,6 +139,16 @@ defp add_csp_param(csp_iodata, nil), do: csp_iodata
 
   defp add_csp_param(csp_iodata, param), do: [[param, ?;] | csp_iodata]
 
+  defp build_csp_param(nil), do: nil
+
+  defp build_csp_param(url) when is_binary(url) do
+    %{host: host, scheme: scheme} = URI.parse(url)
+
+    if scheme do
+      [scheme, "://", host]
+    end
+  end
+
   def warn_if_disabled do
     unless Config.get([:http_security, :enabled]) do
       Logger.warn("