From 455a402c8a967b3a234c836b0574c4f011860d43 Mon Sep 17 00:00:00 2001 From: rinpatch Date: Wed, 27 May 2020 20:27:30 +0300 Subject: [PATCH] HTTP Security plug: rewrite &csp_string/0 - Directives are now separated with ";" instead of " ;", according to https://www.w3.org/TR/CSP2/#policy-parsing the space is optional - Use an IO list, which at the end gets converted to a binary as opposed to ++ing a bunch of arrays with binaries together and joining them to a string. I doubt it gives any significant real world advantage, but the code is cleaner and now I can sleep at night. - The static part of csp is pre-joined to a single binary at compile time. Same reasoning as the last point. --- lib/pleroma/plugs/http_security_plug.ex | 52 ++++++++++++++----------- test/plugs/http_security_plug_test.exs | 2 +- 2 files changed, 31 insertions(+), 23 deletions(-) diff --git a/lib/pleroma/plugs/http_security_plug.ex b/lib/pleroma/plugs/http_security_plug.ex index 6462797b6..f9aff2fab 100644 --- a/lib/pleroma/plugs/http_security_plug.ex +++ b/lib/pleroma/plugs/http_security_plug.ex @@ -31,7 +31,7 @@ defp headers do {"x-content-type-options", "nosniff"}, {"referrer-policy", referrer_policy}, {"x-download-options", "noopen"}, - {"content-security-policy", csp_string() <> ";"} + {"content-security-policy", csp_string()} ] if report_uri do @@ -43,23 +43,35 @@ defp headers do ] } - headers ++ [{"reply-to", Jason.encode!(report_group)}] + [{"reply-to", Jason.encode!(report_group)} | headers] else headers end end + @csp_start [ + "default-src 'none'", + "base-uri 'self'", + "frame-ancestors 'none'", + "style-src 'self' 'unsafe-inline'", + "font-src 'self'", + "manifest-src 'self'" + ] + |> Enum.join(";") + |> Kernel.<>(";") + |> List.wrap() + defp csp_string do scheme = Config.get([Pleroma.Web.Endpoint, :url])[:scheme] static_url = Pleroma.Web.Endpoint.static_url() websocket_url = Pleroma.Web.Endpoint.websocket_url() report_uri = Config.get([:http_security, :report_uri]) - connect_src = "connect-src 'self' #{static_url} #{websocket_url}" + connect_src = ["connect-src 'self' ", static_url, ?\s, websocket_url] connect_src = if Pleroma.Config.get(:env) == :dev do - connect_src <> " http://localhost:3035/" + [connect_src," http://localhost:3035/"] else connect_src end @@ -71,27 +83,23 @@ defp csp_string do "script-src 'self'" end - main_part = [ - "default-src 'none'", - "base-uri 'self'", - "frame-ancestors 'none'", - "img-src 'self' data: blob: https:", - "media-src 'self' https:", - "style-src 'self' 'unsafe-inline'", - "font-src 'self'", - "manifest-src 'self'", - connect_src, - script_src - ] + report = if report_uri, do: ["report-uri ", report_uri, ";report-to csp-endpoint"] + insecure = if scheme == "https", do: "upgrade-insecure-requests" - report = if report_uri, do: ["report-uri #{report_uri}; report-to csp-endpoint"], else: [] - - insecure = if scheme == "https", do: ["upgrade-insecure-requests"], else: [] - - (main_part ++ report ++ insecure) - |> Enum.join("; ") + @csp_start + |> add_csp_param("img-src 'self' data: blob: https:") + |> add_csp_param("media-src 'self' https:") + |> add_csp_param(connect_src) + |> add_csp_param(script_src) + |> add_csp_param(insecure) + |> add_csp_param(report) + |> :erlang.iolist_to_binary() end + defp add_csp_param(csp_iodata, nil), do: csp_iodata + + defp add_csp_param(csp_iodata, param), do: [[param, ?;] | csp_iodata] + def warn_if_disabled do unless Config.get([:http_security, :enabled]) do Logger.warn(" diff --git a/test/plugs/http_security_plug_test.exs b/test/plugs/http_security_plug_test.exs index 84e4c274f..63b4d3f31 100644 --- a/test/plugs/http_security_plug_test.exs +++ b/test/plugs/http_security_plug_test.exs @@ -67,7 +67,7 @@ test "it sends `report-to` & `report-uri` CSP response headers" do [csp] = Conn.get_resp_header(conn, "content-security-policy") - assert csp =~ ~r|report-uri https://endpoint.com; report-to csp-endpoint;| + assert csp =~ ~r|report-uri https://endpoint.com;report-to csp-endpoint;| [reply_to] = Conn.get_resp_header(conn, "reply-to")