X-Git-Url: https://git.squeep.com/?a=blobdiff_plain;f=lib%2Fpleroma%2Fcaptcha%2Fcaptcha.ex;h=6ab754b6f1dc333930471555b5c09c5e593144a0;hb=09d31d24de568aac06fe203beeb8bb2a9de8f602;hp=133a9fd68cf67a73a79e5c2704bc12d4b341626a;hpb=90e157ef803296989b41d1fbfb5096b39320f75d;p=akkoma
diff --git a/lib/pleroma/captcha/captcha.ex b/lib/pleroma/captcha/captcha.ex
index 133a9fd68..6ab754b6f 100644
--- a/lib/pleroma/captcha/captcha.ex
+++ b/lib/pleroma/captcha/captcha.ex
@@ -1,69 +1,101 @@
# Pleroma: A lightweight social networking server
-# Copyright © 2017-2019 Pleroma Authors
+# Copyright © 2017-2020 Pleroma Authors
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.Captcha do
- use GenServer
+ alias Calendar.DateTime
+ alias Plug.Crypto.KeyGenerator
+ alias Plug.Crypto.MessageEncryptor
- @ets_options [:ordered_set, :private, :named_table, {:read_concurrency, true}]
-
- @doc false
- def start_link() do
- GenServer.start_link(__MODULE__, [], name: __MODULE__)
- end
+ @doc """
+ Ask the configured captcha service for a new captcha
+ """
+ def new do
+ if not enabled?() do
+ %{type: :none}
+ else
+ new_captcha = method().new()
- @doc false
- def init(_) do
- # Create a ETS table to store captchas
- ets_name = Module.concat(method(), Ets)
- ^ets_name = :ets.new(Module.concat(method(), Ets), @ets_options)
+ # This make salt a little different for two keys
+ {secret, sign_secret} = secret_pair(new_captcha[:token])
- # Clean up old captchas every few minutes
- seconds_retained = Pleroma.Config.get!([__MODULE__, :seconds_retained])
- Process.send_after(self(), :cleanup, 1000 * seconds_retained)
+ # Basically copy what Phoenix.Token does here, add the time to
+ # the actual data and make it a binary to then encrypt it
+ encrypted_captcha_answer =
+ %{
+ at: DateTime.now_utc(),
+ answer_data: new_captcha[:answer_data]
+ }
+ |> :erlang.term_to_binary()
+ |> MessageEncryptor.encrypt(secret, sign_secret)
- {:ok, nil}
+ # Replace the answer with the encrypted answer
+ %{new_captcha | answer_data: encrypted_captcha_answer}
+ end
end
@doc """
- Ask the configured captcha service for a new captcha
+ Ask the configured captcha service to validate the captcha
"""
- def new() do
- GenServer.call(__MODULE__, :new)
+ def validate(token, captcha, answer_data) do
+ with {:ok, %{at: at, answer_data: answer_md5}} <- validate_answer_data(token, answer_data),
+ :ok <- validate_expiration(at),
+ :ok <- validate_usage(token),
+ :ok <- method().validate(token, captcha, answer_md5),
+ {:ok, _} <- mark_captcha_as_used(token) do
+ :ok
+ end
end
- @doc """
- Ask the configured captcha service to validate the captcha
- """
- def validate(token, captcha) do
- GenServer.call(__MODULE__, {:validate, token, captcha})
+ def enabled?, do: Pleroma.Config.get([__MODULE__, :enabled], false)
+
+ defp seconds_valid, do: Pleroma.Config.get!([__MODULE__, :seconds_valid])
+
+ defp secret_pair(token) do
+ secret_key_base = Pleroma.Config.get!([Pleroma.Web.Endpoint, :secret_key_base])
+ secret = KeyGenerator.generate(secret_key_base, token <> "_encrypt")
+ sign_secret = KeyGenerator.generate(secret_key_base, token <> "_sign")
+
+ {secret, sign_secret}
end
- @doc false
- def handle_call(:new, _from, state) do
- enabled = Pleroma.Config.get([__MODULE__, :enabled])
+ defp validate_answer_data(token, answer_data) do
+ {secret, sign_secret} = secret_pair(token)
- if !enabled do
- {:reply, %{type: :none}, state}
+ with false <- is_nil(answer_data),
+ {:ok, data} <- MessageEncryptor.decrypt(answer_data, secret, sign_secret),
+ %{at: at, answer_data: answer_md5} <- :erlang.binary_to_term(data) do
+ {:ok, %{at: at, answer_data: answer_md5}}
else
- {:reply, method().new(), state}
+ _ -> {:error, :invalid_answer_data}
end
end
- @doc false
- def handle_call({:validate, token, captcha}, _from, state) do
- {:reply, method().validate(token, captcha), state}
- end
+ defp validate_expiration(created_at) do
+ # If the time found is less than (current_time-seconds_valid) then the time has already passed
+ # Later we check that the time found is more than the presumed invalidatation time, that means
+ # that the data is still valid and the captcha can be checked
+
+ valid_if_after = DateTime.subtract!(DateTime.now_utc(), seconds_valid())
- @doc false
- def handle_info(:cleanup, state) do
- :ok = method().cleanup()
+ if DateTime.before?(created_at, valid_if_after) do
+ {:error, :expired}
+ else
+ :ok
+ end
+ end
- seconds_retained = Pleroma.Config.get!([__MODULE__, :seconds_retained])
- # Schedule the next clenup
- Process.send_after(self(), :cleanup, 1000 * seconds_retained)
+ defp validate_usage(token) do
+ if is_nil(Cachex.get!(:used_captcha_cache, token)) do
+ :ok
+ else
+ {:error, :already_used}
+ end
+ end
- {:noreply, state}
+ defp mark_captcha_as_used(token) do
+ ttl = seconds_valid() |> :timer.seconds()
+ Cachex.put(:used_captcha_cache, token, true, ttl: ttl)
end
defp method, do: Pleroma.Config.get!([__MODULE__, :method])