mobilizon.chapril.org-mobil.../lib/web/plugs/http_signatures.ex
Thomas Citharel 3a753312c1
Validate Date header in HTTPSignatures
Signed-off-by: Thomas Citharel <tcit@tcit.fr>
2020-02-14 09:22:17 +01:00

69 lines
1.9 KiB
Elixir
Raw Permalink Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# Portions of this file are derived from Pleroma:
# Copyright © 2017-2018 Pleroma Authors <https://pleroma.social>
# SPDX-License-Identifier: AGPL-3.0-only
# Upstream: https://git.pleroma.social/pleroma/pleroma/blob/develop/lib/pleroma/plugs/http_signature.ex
defmodule Mobilizon.Web.Plugs.HTTPSignatures do
@moduledoc """
Plug to check HTTP Signatures on every incoming request
"""
import Plug.Conn
require Logger
def init(options) do
options
end
def call(%{assigns: %{valid_signature: true}} = conn, _opts) do
conn
end
def call(conn, _opts) do
case get_req_header(conn, "signature") do
[signature | _] ->
if signature do
# set (request-target) header to the appropriate value
# we also replace the digest header with the one we computed
conn =
conn
|> put_req_header(
"(request-target)",
String.downcase("#{conn.method}") <> " #{conn.request_path}"
)
conn =
if conn.assigns[:digest] do
conn
|> put_req_header("digest", conn.assigns[:digest])
else
conn
end
signature_valid = HTTPSignatures.validate_conn(conn)
Logger.debug("Is signature valid ? #{inspect(signature_valid)}")
date_valid = date_valid?(conn)
assign(conn, :valid_signature, signature_valid && date_valid)
else
Logger.debug("No signature header!")
conn
end
_ ->
conn
end
end
@spec date_valid?(Plug.Conn.t()) :: boolean()
defp date_valid?(conn) do
with [date | _] <- get_req_header(conn, "date") || [""],
{:ok, date} <- Timex.parse(date, "{WDshort}, {0D} {Mshort} {YYYY} {h24}:{m}:{s} GMT") do
Timex.diff(date, DateTime.utc_now(), :hours) <= 12 &&
Timex.diff(date, DateTime.utc_now(), :hours) >= -12
else
_ -> false
end
end
end