From a2399c1c7c17ee1c8e85ae0b6095405c7cb9f6f1 Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sat, 15 Dec 2018 01:31:19 +0300
Subject: [PATCH 01/18] Add base CAPTCHA support (currently only kocaptcha)

---
 config/config.exs                             |  7 ++
 lib/pleroma/application.ex                    |  1 +
 lib/pleroma/captcha.ex                        | 68 +++++++++++++++++++
 lib/pleroma/web/router.ex                     |  1 +
 .../controllers/util_controller.ex            |  4 ++
 lib/pleroma/web/twitter_api/twitter_api.ex    | 47 +++++++------
 6 files changed, 109 insertions(+), 19 deletions(-)
 create mode 100644 lib/pleroma/captcha.ex

diff --git a/config/config.exs b/config/config.exs
index 1401b0a3d..df4c618a7 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -10,6 +10,13 @@ config :pleroma, ecto_repos: [Pleroma.Repo]
 
 config :pleroma, Pleroma.Repo, types: Pleroma.PostgresTypes
 
+config :pleroma, Pleroma.Captcha,
+  method: Pleroma.Captcha.Kocaptcha
+
+# Kocaptcha is a very simple captcha service, the source code is here: https://github.com/koto-bank/kocaptcha
+config :pleroma, Pleroma.Captcha.Kocaptcha,
+  endpoint: "http://localhost:9093"
+
 # Upload configuration
 config :pleroma, Pleroma.Upload,
   uploader: Pleroma.Uploaders.Local,
diff --git a/lib/pleroma/application.ex b/lib/pleroma/application.ex
index 8705395a4..e15991957 100644
--- a/lib/pleroma/application.ex
+++ b/lib/pleroma/application.ex
@@ -24,6 +24,7 @@ defmodule Pleroma.Application do
         # Start the Ecto repository
         supervisor(Pleroma.Repo, []),
         worker(Pleroma.Emoji, []),
+        worker(Pleroma.Captcha, []),
         worker(
           Cachex,
           [
diff --git a/lib/pleroma/captcha.ex b/lib/pleroma/captcha.ex
new file mode 100644
index 000000000..31f3bc797
--- /dev/null
+++ b/lib/pleroma/captcha.ex
@@ -0,0 +1,68 @@
+defmodule Pleroma.Captcha do
+  use GenServer
+
+  @ets __MODULE__.Ets
+  @ets_options [:ordered_set, :private, :named_table, {:read_concurrency, true}]
+
+
+  @doc false
+  def start_link() do
+    GenServer.start_link(__MODULE__, [], name: __MODULE__)
+  end
+
+
+  @doc false
+  def init(_) do
+    @ets = :ets.new(@ets, @ets_options)
+
+    {:ok, nil}
+  end
+
+  def new() do
+    GenServer.call(__MODULE__, :new)
+  end
+
+  def validate(token, captcha) do
+    GenServer.call(__MODULE__, {:validate, token, captcha})
+  end
+
+  @doc false
+  def handle_call(:new, _from, state) do
+    method = Pleroma.Config.get!([__MODULE__, :method])
+
+    case method do
+      __MODULE__.Kocaptcha ->
+        endpoint = Pleroma.Config.get!([method, :endpoint])
+        case HTTPoison.get(endpoint <> "/new") do
+          {:error, _} ->
+            %{error: "Kocaptcha service unavailable"}
+          {:ok, res} ->
+            json_resp = Poison.decode!(res.body)
+
+            token = json_resp["token"]
+
+            true = :ets.insert(@ets, {token, json_resp["md5"]})
+
+            {
+              :reply,
+              %{type: :kocaptcha, token: token, url: endpoint <> json_resp["url"]},
+              state
+            }
+        end
+    end
+  end
+
+  @doc false
+  def handle_call({:validate, token, captcha}, _from, state) do
+    with false <- is_nil(captcha),
+         [{^token, saved_md5}] <- :ets.lookup(@ets, token),
+         true <- (:crypto.hash(:md5, captcha) |> Base.encode16) == String.upcase(saved_md5) do
+      # Clear the saved value
+      :ets.delete(@ets, token)
+
+      {:reply, true, state}
+    else
+      e -> IO.inspect(e); {:reply, false, state}
+    end
+  end
+end
diff --git a/lib/pleroma/web/router.ex b/lib/pleroma/web/router.ex
index daff3362c..60342cfb4 100644
--- a/lib/pleroma/web/router.ex
+++ b/lib/pleroma/web/router.ex
@@ -99,6 +99,7 @@ defmodule Pleroma.Web.Router do
     get("/password_reset/:token", UtilController, :show_password_reset)
     post("/password_reset", UtilController, :password_reset)
     get("/emoji", UtilController, :emoji)
+    get("/captcha", UtilController, :captcha)
   end
 
   scope "/api/pleroma/admin", Pleroma.Web.AdminAPI do
diff --git a/lib/pleroma/web/twitter_api/controllers/util_controller.ex b/lib/pleroma/web/twitter_api/controllers/util_controller.ex
index 2f2b69623..38653f0b8 100644
--- a/lib/pleroma/web/twitter_api/controllers/util_controller.ex
+++ b/lib/pleroma/web/twitter_api/controllers/util_controller.ex
@@ -284,4 +284,8 @@ defmodule Pleroma.Web.TwitterAPI.UtilController do
         json(conn, %{error: msg})
     end
   end
+
+  def captcha(conn, _params) do
+    json(conn, Pleroma.Captcha.new())
+  end
 end
diff --git a/lib/pleroma/web/twitter_api/twitter_api.ex b/lib/pleroma/web/twitter_api/twitter_api.ex
index 1e764f24a..c9e8fbcbb 100644
--- a/lib/pleroma/web/twitter_api/twitter_api.ex
+++ b/lib/pleroma/web/twitter_api/twitter_api.ex
@@ -132,38 +132,47 @@ defmodule Pleroma.Web.TwitterAPI.TwitterAPI do
       bio: User.parse_bio(params["bio"]),
       email: params["email"],
       password: params["password"],
-      password_confirmation: params["confirm"]
+      password_confirmation: params["confirm"],
+      captcha_solution: params["captcha_solution"],
+      captcha_token: params["captcha_token"]
     }
 
-    registrations_open = Pleroma.Config.get([:instance, :registrations_open])
+    # Captcha invalid
+    if not Pleroma.Captcha.validate(params[:captcha_token], params[:captcha_solution]) do
+      # I have no idea how this error handling works
+      {:error, %{error: Jason.encode!(%{captcha: ["Invalid CAPTCHA"]})}}
+    else
+      registrations_open = Pleroma.Config.get([:instance, :registrations_open])
 
-    # no need to query DB if registration is open
-    token =
-      unless registrations_open || is_nil(tokenString) do
+      # no need to query DB if registration is open
+      token =
+        unless registrations_open || is_nil(tokenString) do
         Repo.get_by(UserInviteToken, %{token: tokenString})
       end
 
-    cond do
-      registrations_open || (!is_nil(token) && !token.used) ->
-        changeset = User.register_changeset(%User{info: %{}}, params)
+      cond do
+        registrations_open || (!is_nil(token) && !token.used) ->
+          changeset = User.register_changeset(%User{info: %{}}, params)
 
-        with {:ok, user} <- Repo.insert(changeset) do
-          !registrations_open && UserInviteToken.mark_as_used(token.token)
-          {:ok, user}
-        else
-          {:error, changeset} ->
-            errors =
+          with {:ok, user} <- Repo.insert(changeset) do
+            !registrations_open && UserInviteToken.mark_as_used(token.token)
+            {:ok, user}
+          else
+            {:error, changeset} ->
+              errors =
               Ecto.Changeset.traverse_errors(changeset, fn {msg, _opts} -> msg end)
               |> Jason.encode!()
 
             {:error, %{error: errors}}
-        end
+          end
 
-      !registrations_open && is_nil(token) ->
-        {:error, "Invalid token"}
 
-      !registrations_open && token.used ->
-        {:error, "Expired token"}
+        !registrations_open && is_nil(token) ->
+            {:error, "Invalid token"}
+
+        !registrations_open && token.used ->
+            {:error, "Expired token"}
+      end
     end
   end
 

From 28c43a417e89ad68674f6e60d7d3025fbb4655ff Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sat, 15 Dec 2018 02:00:00 +0300
Subject: [PATCH 02/18] Add an ability to disabled captcha

---
 config/config.exs                          |  1 +
 lib/pleroma/captcha.ex                     | 44 +++++++++++++---------
 lib/pleroma/web/twitter_api/twitter_api.ex | 10 ++++-
 3 files changed, 37 insertions(+), 18 deletions(-)

diff --git a/config/config.exs b/config/config.exs
index df4c618a7..32593045c 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -11,6 +11,7 @@ config :pleroma, ecto_repos: [Pleroma.Repo]
 config :pleroma, Pleroma.Repo, types: Pleroma.PostgresTypes
 
 config :pleroma, Pleroma.Captcha,
+  enabled: false,
   method: Pleroma.Captcha.Kocaptcha
 
 # Kocaptcha is a very simple captcha service, the source code is here: https://github.com/koto-bank/kocaptcha
diff --git a/lib/pleroma/captcha.ex b/lib/pleroma/captcha.ex
index 31f3bc797..ffa5640ea 100644
--- a/lib/pleroma/captcha.ex
+++ b/lib/pleroma/captcha.ex
@@ -28,27 +28,37 @@ defmodule Pleroma.Captcha do
 
   @doc false
   def handle_call(:new, _from, state) do
-    method = Pleroma.Config.get!([__MODULE__, :method])
+    enabled = Pleroma.Config.get([__MODULE__, :enabled])
 
-    case method do
-      __MODULE__.Kocaptcha ->
-        endpoint = Pleroma.Config.get!([method, :endpoint])
-        case HTTPoison.get(endpoint <> "/new") do
-          {:error, _} ->
-            %{error: "Kocaptcha service unavailable"}
-          {:ok, res} ->
-            json_resp = Poison.decode!(res.body)
+    if !enabled do
+      {
+        :reply,
+        %{type: :none},
+        state
+      }
+    else
+      method = Pleroma.Config.get!([__MODULE__, :method])
 
-            token = json_resp["token"]
+      case method do
+        __MODULE__.Kocaptcha ->
+          endpoint = Pleroma.Config.get!([method, :endpoint])
+          case HTTPoison.get(endpoint <> "/new") do
+            {:error, _} ->
+              %{error: "Kocaptcha service unavailable"}
+            {:ok, res} ->
+              json_resp = Poison.decode!(res.body)
 
-            true = :ets.insert(@ets, {token, json_resp["md5"]})
+              token = json_resp["token"]
 
-            {
-              :reply,
-              %{type: :kocaptcha, token: token, url: endpoint <> json_resp["url"]},
-              state
-            }
-        end
+              true = :ets.insert(@ets, {token, json_resp["md5"]})
+
+              {
+                :reply,
+                %{type: :kocaptcha, token: token, url: endpoint <> json_resp["url"]},
+                state
+              }
+          end
+      end
     end
   end
 
diff --git a/lib/pleroma/web/twitter_api/twitter_api.ex b/lib/pleroma/web/twitter_api/twitter_api.ex
index c9e8fbcbb..9f98c43c9 100644
--- a/lib/pleroma/web/twitter_api/twitter_api.ex
+++ b/lib/pleroma/web/twitter_api/twitter_api.ex
@@ -137,8 +137,16 @@ defmodule Pleroma.Web.TwitterAPI.TwitterAPI do
       captcha_token: params["captcha_token"]
     }
 
+    captcha_enabled = Pleroma.Config.get([Pleroma.Captcha, :enabled])
+    # true if captcha is disabled or enabled and valid, false otherwise
+    captcha_ok = if !captcha_enabled do
+      true
+    else
+      Pleroma.Captcha.validate(params[:captcha_token], params[:captcha_solution])
+    end
+
     # Captcha invalid
-    if not Pleroma.Captcha.validate(params[:captcha_token], params[:captcha_solution]) do
+    if not captcha_ok do
       # I have no idea how this error handling works
       {:error, %{error: Jason.encode!(%{captcha: ["Invalid CAPTCHA"]})}}
     else

From b5518da90468ab1cde40593695d75f3d72d66783 Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sat, 15 Dec 2018 22:06:44 +0300
Subject: [PATCH 03/18] Separate captcha implementation into a behaviour and
 use it

---
 lib/pleroma/captcha.ex                 | 78 --------------------------
 lib/pleroma/captcha/captcha.ex         | 51 +++++++++++++++++
 lib/pleroma/captcha/captcha_service.ex | 24 ++++++++
 lib/pleroma/captcha/kocaptcha.ex       | 37 ++++++++++++
 4 files changed, 112 insertions(+), 78 deletions(-)
 delete mode 100644 lib/pleroma/captcha.ex
 create mode 100644 lib/pleroma/captcha/captcha.ex
 create mode 100644 lib/pleroma/captcha/captcha_service.ex
 create mode 100644 lib/pleroma/captcha/kocaptcha.ex

diff --git a/lib/pleroma/captcha.ex b/lib/pleroma/captcha.ex
deleted file mode 100644
index ffa5640ea..000000000
--- a/lib/pleroma/captcha.ex
+++ /dev/null
@@ -1,78 +0,0 @@
-defmodule Pleroma.Captcha do
-  use GenServer
-
-  @ets __MODULE__.Ets
-  @ets_options [:ordered_set, :private, :named_table, {:read_concurrency, true}]
-
-
-  @doc false
-  def start_link() do
-    GenServer.start_link(__MODULE__, [], name: __MODULE__)
-  end
-
-
-  @doc false
-  def init(_) do
-    @ets = :ets.new(@ets, @ets_options)
-
-    {:ok, nil}
-  end
-
-  def new() do
-    GenServer.call(__MODULE__, :new)
-  end
-
-  def validate(token, captcha) do
-    GenServer.call(__MODULE__, {:validate, token, captcha})
-  end
-
-  @doc false
-  def handle_call(:new, _from, state) do
-    enabled = Pleroma.Config.get([__MODULE__, :enabled])
-
-    if !enabled do
-      {
-        :reply,
-        %{type: :none},
-        state
-      }
-    else
-      method = Pleroma.Config.get!([__MODULE__, :method])
-
-      case method do
-        __MODULE__.Kocaptcha ->
-          endpoint = Pleroma.Config.get!([method, :endpoint])
-          case HTTPoison.get(endpoint <> "/new") do
-            {:error, _} ->
-              %{error: "Kocaptcha service unavailable"}
-            {:ok, res} ->
-              json_resp = Poison.decode!(res.body)
-
-              token = json_resp["token"]
-
-              true = :ets.insert(@ets, {token, json_resp["md5"]})
-
-              {
-                :reply,
-                %{type: :kocaptcha, token: token, url: endpoint <> json_resp["url"]},
-                state
-              }
-          end
-      end
-    end
-  end
-
-  @doc false
-  def handle_call({:validate, token, captcha}, _from, state) do
-    with false <- is_nil(captcha),
-         [{^token, saved_md5}] <- :ets.lookup(@ets, token),
-         true <- (:crypto.hash(:md5, captcha) |> Base.encode16) == String.upcase(saved_md5) do
-      # Clear the saved value
-      :ets.delete(@ets, token)
-
-      {:reply, true, state}
-    else
-      e -> IO.inspect(e); {:reply, false, state}
-    end
-  end
-end
diff --git a/lib/pleroma/captcha/captcha.ex b/lib/pleroma/captcha/captcha.ex
new file mode 100644
index 000000000..df33406ee
--- /dev/null
+++ b/lib/pleroma/captcha/captcha.ex
@@ -0,0 +1,51 @@
+defmodule Pleroma.Captcha do
+  use GenServer
+
+  @ets_options [:ordered_set, :private, :named_table, {:read_concurrency, true}]
+
+  @doc false
+  def start_link() do
+    GenServer.start_link(__MODULE__, [], name: __MODULE__)
+  end
+
+  @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)
+
+    {:ok, nil}
+  end
+
+  @doc """
+  Ask the configured captcha service for a new captcha
+  """
+  def new() do
+    GenServer.call(__MODULE__, :new)
+  end
+
+  @doc """
+  Ask the configured captcha service to validate the captcha
+  """
+  def validate(token, captcha) do
+    GenServer.call(__MODULE__, {:validate, token, captcha})
+  end
+
+  @doc false
+  def handle_call(:new, _from, state) do
+    enabled = Pleroma.Config.get([__MODULE__, :enabled])
+
+    if !enabled do
+      {:reply, %{type: :none}, state}
+    else
+      {:reply, method().new(), state}
+    end
+  end
+
+  @doc false
+  def handle_call({:validate, token, captcha}, _from, state) do
+    {:reply, method().validate(token, captcha), state}
+  end
+
+  defp method, do: Pleroma.Config.get!([__MODULE__, :method])
+end
diff --git a/lib/pleroma/captcha/captcha_service.ex b/lib/pleroma/captcha/captcha_service.ex
new file mode 100644
index 000000000..ae1d6e7c7
--- /dev/null
+++ b/lib/pleroma/captcha/captcha_service.ex
@@ -0,0 +1,24 @@
+defmodule Pleroma.Captcha.Service do
+
+  @doc """
+  Request new captcha from a captcha service.
+
+  Returns:
+
+  Service-specific data for using the newly created captcha
+  """
+  @callback new() :: map
+
+  @doc """
+  Validated the provided captcha solution.
+
+  Arguments:
+  * `token` the captcha is associated with
+  * `captcha` solution of the captcha to validate
+
+  Returns:
+
+  `true` if captcha is valid, `false` if not
+  """
+  @callback validate(token :: String.t, captcha :: String.t) :: boolean
+end
diff --git a/lib/pleroma/captcha/kocaptcha.ex b/lib/pleroma/captcha/kocaptcha.ex
new file mode 100644
index 000000000..abccbf6d3
--- /dev/null
+++ b/lib/pleroma/captcha/kocaptcha.ex
@@ -0,0 +1,37 @@
+defmodule Pleroma.Captcha.Kocaptcha do
+  alias Pleroma.Captcha.Service
+  @behaviour Service
+
+  @ets __MODULE__.Ets
+
+  @impl Service
+  def new() do
+    endpoint = Pleroma.Config.get!([__MODULE__, :endpoint])
+    case HTTPoison.get(endpoint <> "/new") do
+      {:error, _} ->
+        %{error: "Kocaptcha service unavailable"}
+      {:ok, res} ->
+        json_resp = Poison.decode!(res.body)
+
+        token = json_resp["token"]
+
+        true = :ets.insert(@ets, {token, json_resp["md5"]})
+
+        %{type: :kocaptcha, token: token, url: endpoint <> json_resp["url"]}
+    end
+  end
+
+  @impl Service
+  def validate(token, captcha) do
+    with false <- is_nil(captcha),
+         [{^token, saved_md5}] <- :ets.lookup(@ets, token),
+         true <- (:crypto.hash(:md5, captcha) |> Base.encode16) == String.upcase(saved_md5) do
+      # Clear the saved value
+      :ets.delete(@ets, token)
+
+      true
+    else
+      _ -> false
+    end
+  end
+end

From 23549d39521386f217a57ef1aeb3d660eff06860 Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sat, 15 Dec 2018 22:08:26 +0300
Subject: [PATCH 04/18] Formatting fixes

---
 config/config.exs                          |  3 +--
 lib/pleroma/captcha/captcha_service.ex     |  3 +--
 lib/pleroma/captcha/kocaptcha.ex           |  4 +++-
 lib/pleroma/web/twitter_api/twitter_api.ex | 26 +++++++++++-----------
 4 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/config/config.exs b/config/config.exs
index 32593045c..b7d439e9d 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -15,8 +15,7 @@ config :pleroma, Pleroma.Captcha,
   method: Pleroma.Captcha.Kocaptcha
 
 # Kocaptcha is a very simple captcha service, the source code is here: https://github.com/koto-bank/kocaptcha
-config :pleroma, Pleroma.Captcha.Kocaptcha,
-  endpoint: "http://localhost:9093"
+config :pleroma, Pleroma.Captcha.Kocaptcha, endpoint: "http://localhost:9093"
 
 # Upload configuration
 config :pleroma, Pleroma.Upload,
diff --git a/lib/pleroma/captcha/captcha_service.ex b/lib/pleroma/captcha/captcha_service.ex
index ae1d6e7c7..907a73ad0 100644
--- a/lib/pleroma/captcha/captcha_service.ex
+++ b/lib/pleroma/captcha/captcha_service.ex
@@ -1,5 +1,4 @@
 defmodule Pleroma.Captcha.Service do
-
   @doc """
   Request new captcha from a captcha service.
 
@@ -20,5 +19,5 @@ defmodule Pleroma.Captcha.Service do
 
   `true` if captcha is valid, `false` if not
   """
-  @callback validate(token :: String.t, captcha :: String.t) :: boolean
+  @callback validate(token :: String.t(), captcha :: String.t()) :: boolean
 end
diff --git a/lib/pleroma/captcha/kocaptcha.ex b/lib/pleroma/captcha/kocaptcha.ex
index abccbf6d3..173ce17f7 100644
--- a/lib/pleroma/captcha/kocaptcha.ex
+++ b/lib/pleroma/captcha/kocaptcha.ex
@@ -7,9 +7,11 @@ defmodule Pleroma.Captcha.Kocaptcha do
   @impl Service
   def new() do
     endpoint = Pleroma.Config.get!([__MODULE__, :endpoint])
+
     case HTTPoison.get(endpoint <> "/new") do
       {:error, _} ->
         %{error: "Kocaptcha service unavailable"}
+
       {:ok, res} ->
         json_resp = Poison.decode!(res.body)
 
@@ -25,7 +27,7 @@ defmodule Pleroma.Captcha.Kocaptcha do
   def validate(token, captcha) do
     with false <- is_nil(captcha),
          [{^token, saved_md5}] <- :ets.lookup(@ets, token),
-         true <- (:crypto.hash(:md5, captcha) |> Base.encode16) == String.upcase(saved_md5) do
+         true <- :crypto.hash(:md5, captcha) |> Base.encode16() == String.upcase(saved_md5) do
       # Clear the saved value
       :ets.delete(@ets, token)
 
diff --git a/lib/pleroma/web/twitter_api/twitter_api.ex b/lib/pleroma/web/twitter_api/twitter_api.ex
index 9f98c43c9..90b8345c5 100644
--- a/lib/pleroma/web/twitter_api/twitter_api.ex
+++ b/lib/pleroma/web/twitter_api/twitter_api.ex
@@ -139,11 +139,12 @@ defmodule Pleroma.Web.TwitterAPI.TwitterAPI do
 
     captcha_enabled = Pleroma.Config.get([Pleroma.Captcha, :enabled])
     # true if captcha is disabled or enabled and valid, false otherwise
-    captcha_ok = if !captcha_enabled do
-      true
-    else
-      Pleroma.Captcha.validate(params[:captcha_token], params[:captcha_solution])
-    end
+    captcha_ok =
+      if !captcha_enabled do
+        true
+      else
+        Pleroma.Captcha.validate(params[:captcha_token], params[:captcha_solution])
+      end
 
     # Captcha invalid
     if not captcha_ok do
@@ -155,8 +156,8 @@ defmodule Pleroma.Web.TwitterAPI.TwitterAPI do
       # no need to query DB if registration is open
       token =
         unless registrations_open || is_nil(tokenString) do
-        Repo.get_by(UserInviteToken, %{token: tokenString})
-      end
+          Repo.get_by(UserInviteToken, %{token: tokenString})
+        end
 
       cond do
         registrations_open || (!is_nil(token) && !token.used) ->
@@ -168,18 +169,17 @@ defmodule Pleroma.Web.TwitterAPI.TwitterAPI do
           else
             {:error, changeset} ->
               errors =
-              Ecto.Changeset.traverse_errors(changeset, fn {msg, _opts} -> msg end)
-              |> Jason.encode!()
+                Ecto.Changeset.traverse_errors(changeset, fn {msg, _opts} -> msg end)
+                |> Jason.encode!()
 
-            {:error, %{error: errors}}
+              {:error, %{error: errors}}
           end
 
-
         !registrations_open && is_nil(token) ->
-            {:error, "Invalid token"}
+          {:error, "Invalid token"}
 
         !registrations_open && token.used ->
-            {:error, "Expired token"}
+          {:error, "Expired token"}
       end
     end
   end

From 98e10c0d4f9d0aa32e34d706c9aa5919a64c2db2 Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sat, 15 Dec 2018 22:12:20 +0300
Subject: [PATCH 05/18] Add captcha documentation to config.md

---
 config/config.exs |  1 -
 config/config.md  | 12 +++++++++++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/config/config.exs b/config/config.exs
index b7d439e9d..5149e9c41 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -14,7 +14,6 @@ config :pleroma, Pleroma.Captcha,
   enabled: false,
   method: Pleroma.Captcha.Kocaptcha
 
-# Kocaptcha is a very simple captcha service, the source code is here: https://github.com/koto-bank/kocaptcha
 config :pleroma, Pleroma.Captcha.Kocaptcha, endpoint: "http://localhost:9093"
 
 # Upload configuration
diff --git a/config/config.md b/config/config.md
index 8282eab14..e8b5e52cb 100644
--- a/config/config.md
+++ b/config/config.md
@@ -7,7 +7,7 @@ If you run Pleroma with ``MIX_ENV=prod`` the file is ``prod.secret.exs``, otherw
 * `uploader`: Select which `Pleroma.Uploaders` to use
 * `filters`: List of `Pleroma.Upload.Filter` to use.
 * `base_url`: The base URL to access a user-uploaded file. Useful when you want to proxy the media files via another host.
-* `proxy_remote`: If you're using a remote uploader, Pleroma will proxy media requests instead of redirecting to it.
+* `proxy_remote`: If you\'re using a remote uploader, Pleroma will proxy media requests instead of redirecting to it.
 * `proxy_opts`: Proxy options, see `Pleroma.ReverseProxy` documentation.
 
 Note: `strip_exif` has been replaced by `Pleroma.Upload.Filter.Mogrify`.
@@ -163,3 +163,13 @@ Web Push Notifications configuration. You can use the mix task `mix web_push.gen
 * ``subject``: a mailto link for the administrative contact. It’s best if this email is not a personal email address, but rather a group email so that if a person leaves an organization, is unavailable for an extended period, or otherwise can’t respond, someone else on the list can.
 * ``public_key``: VAPID public key
 * ``private_key``: VAPID private key
+
+## Pleroma.Captcha
+* `enabled`: Whether the captcha should be shown on registration
+* `method`: The method/service to use for captcha
+
+### Pleroma.Captcha.Kocaptcha
+Kocaptcha is a very simple captcha service with a single API endpoint,
+the source code is here: https://github.com/koto-bank/kocaptcha
+
+* `endpoint`: the kocaptcha endpoint to use
\ No newline at end of file

From e8537208bd9af701cbfc788ca307b8352306a36b Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sat, 15 Dec 2018 22:38:39 +0300
Subject: [PATCH 06/18] Add a captcha mock for tests

---
 config/test.exs              |  5 +++++
 test/support/captcha_mock.ex | 10 ++++++++++
 2 files changed, 15 insertions(+)
 create mode 100644 test/support/captcha_mock.ex

diff --git a/config/test.exs b/config/test.exs
index 5c6acfead..f5348bd46 100644
--- a/config/test.exs
+++ b/config/test.exs
@@ -6,6 +6,11 @@ config :pleroma, Pleroma.Web.Endpoint,
   http: [port: 4001],
   server: false
 
+# Disable captha for tests
+config :pleroma, Pleroma.Captcha,
+  enabled: true,
+  method: Pleroma.Captcha.Mock # A fake captcha service for tests
+
 # Print only warnings and errors during test
 config :logger, level: :warn
 
diff --git a/test/support/captcha_mock.ex b/test/support/captcha_mock.ex
new file mode 100644
index 000000000..9d79f2e95
--- /dev/null
+++ b/test/support/captcha_mock.ex
@@ -0,0 +1,10 @@
+defmodule Pleroma.Captcha.Mock do
+  alias Pleroma.Captcha.Service
+  @behaviour Service
+
+  @impl Service
+  def new(), do: %{type: :mock}
+
+  @impl Service
+  def validate(_token, _captcha), do: true
+end

From 8d55a549e678daa057fce81d1d2ee46b2f8c5545 Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sat, 15 Dec 2018 22:43:28 +0300
Subject: [PATCH 07/18] Replace HTTPoison with Tesla for kocaptha

---
 lib/pleroma/captcha/kocaptcha.ex | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/pleroma/captcha/kocaptcha.ex b/lib/pleroma/captcha/kocaptcha.ex
index 173ce17f7..4ecd1a81f 100644
--- a/lib/pleroma/captcha/kocaptcha.ex
+++ b/lib/pleroma/captcha/kocaptcha.ex
@@ -8,7 +8,7 @@ defmodule Pleroma.Captcha.Kocaptcha do
   def new() do
     endpoint = Pleroma.Config.get!([__MODULE__, :endpoint])
 
-    case HTTPoison.get(endpoint <> "/new") do
+    case Tesla.get(endpoint <> "/new") do
       {:error, _} ->
         %{error: "Kocaptcha service unavailable"}
 

From 5f96c2d216c2728367dfdacb2dbbfc92eb30ce3c Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sat, 15 Dec 2018 23:38:19 +0300
Subject: [PATCH 08/18] Add a test for kocaptcha

---
 test/captcha_test.ex | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 test/captcha_test.ex

diff --git a/test/captcha_test.ex b/test/captcha_test.ex
new file mode 100644
index 000000000..3942cb051
--- /dev/null
+++ b/test/captcha_test.ex
@@ -0,0 +1,41 @@
+defmodule Pleroma.CaptchaTest do
+  use ExUnit.Case
+
+  import Tesla.Mock
+
+  @ets_options [:ordered_set, :private, :named_table, {:read_concurrency, true}]
+
+  describe "Kocaptcha" do
+
+    setup do
+      ets_name = Pleroma.Captcha.Kocaptcha.Ets
+      ^ets_name = :ets.new(ets_name, @ets_options)
+
+      mock fn
+        %{method: :get, url: "http://localhost:9093/new"} ->
+          json(
+            %{
+              md5: "63615261b77f5354fb8c4e4986477555",
+              token: "afa1815e14e29355e6c8f6b143a39fa2",
+              url: "/captchas/afa1815e14e29355e6c8f6b143a39fa2.png"
+            }
+          )
+      end
+
+      :ok
+    end
+
+    test "new and validate" do
+      assert Pleroma.Captcha.Kocaptcha.new() == %{
+        type: :kocaptcha,
+        token: "afa1815e14e29355e6c8f6b143a39fa2",
+        url: "http://localhost:9093/captchas/afa1815e14e29355e6c8f6b143a39fa2.png"
+      }
+
+      assert Pleroma.Captcha.Kocaptcha.validate(
+        "afa1815e14e29355e6c8f6b143a39fa2",
+        "7oEy8c"
+      )
+    end
+  end
+end

From c859cd1d61d81db4999c594ef61164d752d76145 Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sat, 15 Dec 2018 23:39:23 +0300
Subject: [PATCH 09/18] Fix style

---
 config/test.exs      |  3 ++-
 test/captcha_test.ex | 31 ++++++++++++++-----------------
 2 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/config/test.exs b/config/test.exs
index f5348bd46..5670e11a0 100644
--- a/config/test.exs
+++ b/config/test.exs
@@ -9,7 +9,8 @@ config :pleroma, Pleroma.Web.Endpoint,
 # Disable captha for tests
 config :pleroma, Pleroma.Captcha,
   enabled: true,
-  method: Pleroma.Captcha.Mock # A fake captcha service for tests
+  # A fake captcha service for tests
+  method: Pleroma.Captcha.Mock
 
 # Print only warnings and errors during test
 config :logger, level: :warn
diff --git a/test/captcha_test.ex b/test/captcha_test.ex
index 3942cb051..98e8da79b 100644
--- a/test/captcha_test.ex
+++ b/test/captcha_test.ex
@@ -6,36 +6,33 @@ defmodule Pleroma.CaptchaTest do
   @ets_options [:ordered_set, :private, :named_table, {:read_concurrency, true}]
 
   describe "Kocaptcha" do
-
     setup do
       ets_name = Pleroma.Captcha.Kocaptcha.Ets
       ^ets_name = :ets.new(ets_name, @ets_options)
 
-      mock fn
+      mock(fn
         %{method: :get, url: "http://localhost:9093/new"} ->
-          json(
-            %{
-              md5: "63615261b77f5354fb8c4e4986477555",
-              token: "afa1815e14e29355e6c8f6b143a39fa2",
-              url: "/captchas/afa1815e14e29355e6c8f6b143a39fa2.png"
-            }
-          )
-      end
+          json(%{
+            md5: "63615261b77f5354fb8c4e4986477555",
+            token: "afa1815e14e29355e6c8f6b143a39fa2",
+            url: "/captchas/afa1815e14e29355e6c8f6b143a39fa2.png"
+          })
+      end)
 
       :ok
     end
 
     test "new and validate" do
       assert Pleroma.Captcha.Kocaptcha.new() == %{
-        type: :kocaptcha,
-        token: "afa1815e14e29355e6c8f6b143a39fa2",
-        url: "http://localhost:9093/captchas/afa1815e14e29355e6c8f6b143a39fa2.png"
-      }
+               type: :kocaptcha,
+               token: "afa1815e14e29355e6c8f6b143a39fa2",
+               url: "http://localhost:9093/captchas/afa1815e14e29355e6c8f6b143a39fa2.png"
+             }
 
       assert Pleroma.Captcha.Kocaptcha.validate(
-        "afa1815e14e29355e6c8f6b143a39fa2",
-        "7oEy8c"
-      )
+               "afa1815e14e29355e6c8f6b143a39fa2",
+               "7oEy8c"
+             )
     end
   end
 end

From 2e72d49e373abf2957df82db6f8031c62936f9ba Mon Sep 17 00:00:00 2001
From: vaartis <vaartis@cock.li>
Date: Sun, 16 Dec 2018 07:35:45 +0000
Subject: [PATCH 10/18] Rename captcha_test.ex to exs

---
 test/{captcha_test.ex => captcha_test.exs} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename test/{captcha_test.ex => captcha_test.exs} (100%)

diff --git a/test/captcha_test.ex b/test/captcha_test.exs
similarity index 100%
rename from test/captcha_test.ex
rename to test/captcha_test.exs

From 6062885df6178c09544b6a0b5b731a554786397e Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sun, 16 Dec 2018 22:04:43 +0300
Subject: [PATCH 11/18] Add a configurable auto-cleanup for captchas

---
 config/config.exs                      |  1 +
 config/config.md                       |  1 +
 lib/pleroma/captcha/captcha.ex         | 15 ++++++++++++++-
 lib/pleroma/captcha/captcha_service.ex |  5 +++++
 lib/pleroma/captcha/kocaptcha.ex       | 11 ++++++++++-
 5 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/config/config.exs b/config/config.exs
index 5149e9c41..21cdc0537 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -12,6 +12,7 @@ config :pleroma, Pleroma.Repo, types: Pleroma.PostgresTypes
 
 config :pleroma, Pleroma.Captcha,
   enabled: false,
+  minutes_retained: 5,
   method: Pleroma.Captcha.Kocaptcha
 
 config :pleroma, Pleroma.Captcha.Kocaptcha, endpoint: "http://localhost:9093"
diff --git a/config/config.md b/config/config.md
index e8b5e52cb..65f0866fd 100644
--- a/config/config.md
+++ b/config/config.md
@@ -167,6 +167,7 @@ Web Push Notifications configuration. You can use the mix task `mix web_push.gen
 ## Pleroma.Captcha
 * `enabled`: Whether the captcha should be shown on registration
 * `method`: The method/service to use for captcha
+* `minutes_retained`: The time in minutes for which the captcha is valid (stored in the cache)
 
 ### Pleroma.Captcha.Kocaptcha
 Kocaptcha is a very simple captcha service with a single API endpoint,
diff --git a/lib/pleroma/captcha/captcha.ex b/lib/pleroma/captcha/captcha.ex
index df33406ee..2dcbc4717 100644
--- a/lib/pleroma/captcha/captcha.ex
+++ b/lib/pleroma/captcha/captcha.ex
@@ -38,7 +38,13 @@ defmodule Pleroma.Captcha do
     if !enabled do
       {:reply, %{type: :none}, state}
     else
-      {:reply, method().new(), state}
+      new_captcha = method().new()
+
+      minutes_retained = Pleroma.Config.get!([__MODULE__, :minutes_retained])
+      # Wait several minutes and if the captcha is still there, delete it
+      Process.send_after(self(), {:cleanup, new_captcha.token}, 1000 * 60 * minutes_retained)
+
+      {:reply, new_captcha, state}
     end
   end
 
@@ -47,5 +53,12 @@ defmodule Pleroma.Captcha do
     {:reply, method().validate(token, captcha), state}
   end
 
+  @doc false
+  def handle_info({:cleanup, token}, state) do
+    method().cleanup(token)
+
+    {:noreply, state}
+  end
+
   defp method, do: Pleroma.Config.get!([__MODULE__, :method])
 end
diff --git a/lib/pleroma/captcha/captcha_service.ex b/lib/pleroma/captcha/captcha_service.ex
index 907a73ad0..fe5a6bf66 100644
--- a/lib/pleroma/captcha/captcha_service.ex
+++ b/lib/pleroma/captcha/captcha_service.ex
@@ -20,4 +20,9 @@ defmodule Pleroma.Captcha.Service do
   `true` if captcha is valid, `false` if not
   """
   @callback validate(token :: String.t(), captcha :: String.t()) :: boolean
+
+  @doc """
+  This function is called periodically to clean up old captchas
+  """
+  @callback cleanup(token :: String.t()) :: :ok
 end
diff --git a/lib/pleroma/captcha/kocaptcha.ex b/lib/pleroma/captcha/kocaptcha.ex
index 4ecd1a81f..9891d4031 100644
--- a/lib/pleroma/captcha/kocaptcha.ex
+++ b/lib/pleroma/captcha/kocaptcha.ex
@@ -29,11 +29,20 @@ defmodule Pleroma.Captcha.Kocaptcha do
          [{^token, saved_md5}] <- :ets.lookup(@ets, token),
          true <- :crypto.hash(:md5, captcha) |> Base.encode16() == String.upcase(saved_md5) do
       # Clear the saved value
-      :ets.delete(@ets, token)
+      cleanup(token)
 
       true
     else
       _ -> false
     end
   end
+
+  @impl Service
+  def cleanup(token) do
+    # Only delete the entry if it exists in the table, because ets:delete raises an exception if it does not
+    case :ets.lookup(@ets, token) do
+      [{^token, _}] -> :ets.delete(@ets, token)
+      _ -> true
+    end
+  end
 end

From 1d31fd0722c27803adc077e2efb424229f31d361 Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sun, 16 Dec 2018 22:37:16 +0300
Subject: [PATCH 12/18] Make the hosted kocaptcha the default value

---
 config/config.exs | 2 +-
 config/config.md  | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/config/config.exs b/config/config.exs
index 21cdc0537..eba401d3e 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -15,7 +15,7 @@ config :pleroma, Pleroma.Captcha,
   minutes_retained: 5,
   method: Pleroma.Captcha.Kocaptcha
 
-config :pleroma, Pleroma.Captcha.Kocaptcha, endpoint: "http://localhost:9093"
+config :pleroma, Pleroma.Captcha.Kocaptcha, endpoint: "https://captcha.kotobank.ch"
 
 # Upload configuration
 config :pleroma, Pleroma.Upload,
diff --git a/config/config.md b/config/config.md
index 65f0866fd..324f837ce 100644
--- a/config/config.md
+++ b/config/config.md
@@ -171,6 +171,7 @@ Web Push Notifications configuration. You can use the mix task `mix web_push.gen
 
 ### Pleroma.Captcha.Kocaptcha
 Kocaptcha is a very simple captcha service with a single API endpoint,
-the source code is here: https://github.com/koto-bank/kocaptcha
+the source code is here: https://github.com/koto-bank/kocaptcha. The default endpoint
+`https://captcha.kotobank.ch` is hosted by the developer.
 
 * `endpoint`: the kocaptcha endpoint to use
\ No newline at end of file

From 3a31fdaf0668b4fb4d05c3087674c2b32b6afbe9 Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sun, 16 Dec 2018 22:40:44 +0300
Subject: [PATCH 13/18] Change minutes_retained config to seconds_retained

---
 config/config.exs              | 2 +-
 lib/pleroma/captcha/captcha.ex | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/config/config.exs b/config/config.exs
index eba401d3e..45a22f5da 100644
--- a/config/config.exs
+++ b/config/config.exs
@@ -12,7 +12,7 @@ config :pleroma, Pleroma.Repo, types: Pleroma.PostgresTypes
 
 config :pleroma, Pleroma.Captcha,
   enabled: false,
-  minutes_retained: 5,
+  seconds_retained: 180,
   method: Pleroma.Captcha.Kocaptcha
 
 config :pleroma, Pleroma.Captcha.Kocaptcha, endpoint: "https://captcha.kotobank.ch"
diff --git a/lib/pleroma/captcha/captcha.ex b/lib/pleroma/captcha/captcha.ex
index 2dcbc4717..26477a214 100644
--- a/lib/pleroma/captcha/captcha.ex
+++ b/lib/pleroma/captcha/captcha.ex
@@ -40,9 +40,9 @@ defmodule Pleroma.Captcha do
     else
       new_captcha = method().new()
 
-      minutes_retained = Pleroma.Config.get!([__MODULE__, :minutes_retained])
+      seconds_retained = Pleroma.Config.get!([__MODULE__, :seconds_retained])
       # Wait several minutes and if the captcha is still there, delete it
-      Process.send_after(self(), {:cleanup, new_captcha.token}, 1000 * 60 * minutes_retained)
+      Process.send_after(self(), {:cleanup, new_captcha.token}, 1000 * seconds_retained)
 
       {:reply, new_captcha, state}
     end

From 73576ab64ef00aa012dbabae907e03faa436c212 Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sun, 16 Dec 2018 23:01:44 +0300
Subject: [PATCH 14/18] Fix captcha tests

---
 test/captcha_test.exs        | 4 ++--
 test/support/captcha_mock.ex | 3 +++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/test/captcha_test.exs b/test/captcha_test.exs
index 98e8da79b..2729e1382 100644
--- a/test/captcha_test.exs
+++ b/test/captcha_test.exs
@@ -11,7 +11,7 @@ defmodule Pleroma.CaptchaTest do
       ^ets_name = :ets.new(ets_name, @ets_options)
 
       mock(fn
-        %{method: :get, url: "http://localhost:9093/new"} ->
+        %{method: :get, url: "https://captcha.kotobank.ch/new"} ->
           json(%{
             md5: "63615261b77f5354fb8c4e4986477555",
             token: "afa1815e14e29355e6c8f6b143a39fa2",
@@ -26,7 +26,7 @@ defmodule Pleroma.CaptchaTest do
       assert Pleroma.Captcha.Kocaptcha.new() == %{
                type: :kocaptcha,
                token: "afa1815e14e29355e6c8f6b143a39fa2",
-               url: "http://localhost:9093/captchas/afa1815e14e29355e6c8f6b143a39fa2.png"
+               url: "https://captcha.kotobank.ch/captchas/afa1815e14e29355e6c8f6b143a39fa2.png"
              }
 
       assert Pleroma.Captcha.Kocaptcha.validate(
diff --git a/test/support/captcha_mock.ex b/test/support/captcha_mock.ex
index 9d79f2e95..560d6c457 100644
--- a/test/support/captcha_mock.ex
+++ b/test/support/captcha_mock.ex
@@ -7,4 +7,7 @@ defmodule Pleroma.Captcha.Mock do
 
   @impl Service
   def validate(_token, _captcha), do: true
+
+  @impl Service
+  def cleanup(_token), do: true
 end

From ef6829382aa32c03cf8536422537a9c219bd0035 Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Sun, 16 Dec 2018 23:41:11 +0300
Subject: [PATCH 15/18] Clean captchas up periodically, not schedule it after
 theyre created

---
 lib/pleroma/captcha/captcha.ex         | 20 +++++++++++---------
 lib/pleroma/captcha/captcha_service.ex |  2 +-
 lib/pleroma/captcha/kocaptcha.ex       | 26 +++++++++++++++++---------
 test/support/captcha_mock.ex           |  2 +-
 4 files changed, 30 insertions(+), 20 deletions(-)

diff --git a/lib/pleroma/captcha/captcha.ex b/lib/pleroma/captcha/captcha.ex
index 26477a214..5630f6b57 100644
--- a/lib/pleroma/captcha/captcha.ex
+++ b/lib/pleroma/captcha/captcha.ex
@@ -14,6 +14,10 @@ defmodule Pleroma.Captcha do
     ets_name = Module.concat(method(), Ets)
     ^ets_name = :ets.new(Module.concat(method(), Ets), @ets_options)
 
+    # Clean up old captchas every few minutes
+    seconds_retained = Pleroma.Config.get!([__MODULE__, :seconds_retained])
+    Process.send_after(self(), :cleanup, 1000 * seconds_retained)
+
     {:ok, nil}
   end
 
@@ -38,13 +42,7 @@ defmodule Pleroma.Captcha do
     if !enabled do
       {:reply, %{type: :none}, state}
     else
-      new_captcha = method().new()
-
-      seconds_retained = Pleroma.Config.get!([__MODULE__, :seconds_retained])
-      # Wait several minutes and if the captcha is still there, delete it
-      Process.send_after(self(), {:cleanup, new_captcha.token}, 1000 * seconds_retained)
-
-      {:reply, new_captcha, state}
+      {:reply, method().new(), state}
     end
   end
 
@@ -54,8 +52,12 @@ defmodule Pleroma.Captcha do
   end
 
   @doc false
-  def handle_info({:cleanup, token}, state) do
-    method().cleanup(token)
+  def handle_info(:cleanup, state) do
+    :ok = method().cleanup()
+
+    seconds_retained = Pleroma.Config.get!([__MODULE__, :seconds_retained])
+    # Schedule the next clenup
+    Process.send_after(self(), :cleanup, 1000 * seconds_retained)
 
     {:noreply, state}
   end
diff --git a/lib/pleroma/captcha/captcha_service.ex b/lib/pleroma/captcha/captcha_service.ex
index fe5a6bf66..8d0b76f86 100644
--- a/lib/pleroma/captcha/captcha_service.ex
+++ b/lib/pleroma/captcha/captcha_service.ex
@@ -24,5 +24,5 @@ defmodule Pleroma.Captcha.Service do
   @doc """
   This function is called periodically to clean up old captchas
   """
-  @callback cleanup(token :: String.t()) :: :ok
+  @callback cleanup() :: :ok
 end
diff --git a/lib/pleroma/captcha/kocaptcha.ex b/lib/pleroma/captcha/kocaptcha.ex
index 9891d4031..7f9637ad0 100644
--- a/lib/pleroma/captcha/kocaptcha.ex
+++ b/lib/pleroma/captcha/kocaptcha.ex
@@ -1,4 +1,6 @@
 defmodule Pleroma.Captcha.Kocaptcha do
+  alias Calendar.DateTime
+
   alias Pleroma.Captcha.Service
   @behaviour Service
 
@@ -17,7 +19,7 @@ defmodule Pleroma.Captcha.Kocaptcha do
 
         token = json_resp["token"]
 
-        true = :ets.insert(@ets, {token, json_resp["md5"]})
+        true = :ets.insert(@ets, {token, json_resp["md5"], DateTime.now_utc()})
 
         %{type: :kocaptcha, token: token, url: endpoint <> json_resp["url"]}
     end
@@ -26,10 +28,10 @@ defmodule Pleroma.Captcha.Kocaptcha do
   @impl Service
   def validate(token, captcha) do
     with false <- is_nil(captcha),
-         [{^token, saved_md5}] <- :ets.lookup(@ets, token),
+         [{^token, saved_md5, _}] <- :ets.lookup(@ets, token),
          true <- :crypto.hash(:md5, captcha) |> Base.encode16() == String.upcase(saved_md5) do
       # Clear the saved value
-      cleanup(token)
+      :ets.delete(@ets, token)
 
       true
     else
@@ -38,11 +40,17 @@ defmodule Pleroma.Captcha.Kocaptcha do
   end
 
   @impl Service
-  def cleanup(token) do
-    # Only delete the entry if it exists in the table, because ets:delete raises an exception if it does not
-    case :ets.lookup(@ets, token) do
-      [{^token, _}] -> :ets.delete(@ets, token)
-      _ -> true
-    end
+  def cleanup() do
+    seconds_retained = Pleroma.Config.get!([Pleroma.Captcha, :seconds_retained])
+
+    # Go through captchas and remove expired ones
+    :ets.tab2list(@ets)
+    |> Enum.each(fn {token, _, time_inserted} ->
+      # time created + expiration time = time when the captcha should be removed
+      remove_time = DateTime.add!(time_inserted, seconds_retained)
+      if DateTime.after?(DateTime.now_utc(), remove_time), do: :ets.delete(@ets, token)
+    end)
+
+    :ok
   end
 end
diff --git a/test/support/captcha_mock.ex b/test/support/captcha_mock.ex
index 560d6c457..898aa17b8 100644
--- a/test/support/captcha_mock.ex
+++ b/test/support/captcha_mock.ex
@@ -9,5 +9,5 @@ defmodule Pleroma.Captcha.Mock do
   def validate(_token, _captcha), do: true
 
   @impl Service
-  def cleanup(_token), do: true
+  def cleanup(), do: :ok
 end

From 6e2f64a0a65a2c6fe2aacab164ab0a08341be919 Mon Sep 17 00:00:00 2001
From: vaartis <vaartis@cock.li>
Date: Mon, 17 Dec 2018 06:41:41 +0000
Subject: [PATCH 16/18] minutes->seconds_retained in config.md

---
 config/config.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/config/config.md b/config/config.md
index 324f837ce..edabd6e0f 100644
--- a/config/config.md
+++ b/config/config.md
@@ -167,7 +167,7 @@ Web Push Notifications configuration. You can use the mix task `mix web_push.gen
 ## Pleroma.Captcha
 * `enabled`: Whether the captcha should be shown on registration
 * `method`: The method/service to use for captcha
-* `minutes_retained`: The time in minutes for which the captcha is valid (stored in the cache)
+* `seconds_retained`: The time in seconds for which the captcha is valid (stored in the cache)
 
 ### Pleroma.Captcha.Kocaptcha
 Kocaptcha is a very simple captcha service with a single API endpoint,

From 35522fef0958c2843107a6c9cce546e7e0dfcd44 Mon Sep 17 00:00:00 2001
From: vaartis <vaartis@cock.li>
Date: Mon, 17 Dec 2018 17:19:28 +0300
Subject: [PATCH 17/18] Use :ets.match_delete to delete old captchas

---
 lib/pleroma/captcha/kocaptcha.ex | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/lib/pleroma/captcha/kocaptcha.ex b/lib/pleroma/captcha/kocaptcha.ex
index 7f9637ad0..51900d123 100644
--- a/lib/pleroma/captcha/kocaptcha.ex
+++ b/lib/pleroma/captcha/kocaptcha.ex
@@ -19,7 +19,11 @@ defmodule Pleroma.Captcha.Kocaptcha do
 
         token = json_resp["token"]
 
-        true = :ets.insert(@ets, {token, json_resp["md5"], DateTime.now_utc()})
+        true =
+          :ets.insert(
+            @ets,
+            {token, json_resp["md5"], DateTime.now_utc() |> DateTime.Format.unix()}
+          )
 
         %{type: :kocaptcha, token: token, url: endpoint <> json_resp["url"]}
     end
@@ -42,14 +46,21 @@ defmodule Pleroma.Captcha.Kocaptcha do
   @impl Service
   def cleanup() do
     seconds_retained = Pleroma.Config.get!([Pleroma.Captcha, :seconds_retained])
+    # If the time in ETS is less than current_time - seconds_retained, then the time has
+    # already passed
+    delete_after =
+      DateTime.subtract!(DateTime.now_utc(), seconds_retained) |> DateTime.Format.unix()
 
-    # Go through captchas and remove expired ones
-    :ets.tab2list(@ets)
-    |> Enum.each(fn {token, _, time_inserted} ->
-      # time created + expiration time = time when the captcha should be removed
-      remove_time = DateTime.add!(time_inserted, seconds_retained)
-      if DateTime.after?(DateTime.now_utc(), remove_time), do: :ets.delete(@ets, token)
-    end)
+    :ets.select_delete(
+      @ets,
+      [
+        {
+          {:_, :_, :"$1"},
+          [{:<, :"$1", {:const, delete_after}}],
+          [true]
+        }
+      ]
+    )
 
     :ok
   end

From de981ac5a23673797951096b64a7f5ca49630467 Mon Sep 17 00:00:00 2001
From: Ekaterina Vaartis <vaartis@cock.li>
Date: Mon, 17 Dec 2018 20:53:42 +0300
Subject: [PATCH 18/18] Alias Kocaptcha in the test

---
 test/captcha_test.exs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/test/captcha_test.exs b/test/captcha_test.exs
index 2729e1382..54ffbd92f 100644
--- a/test/captcha_test.exs
+++ b/test/captcha_test.exs
@@ -3,11 +3,13 @@ defmodule Pleroma.CaptchaTest do
 
   import Tesla.Mock
 
+  alias Pleroma.Captcha.Kocaptcha
+
   @ets_options [:ordered_set, :private, :named_table, {:read_concurrency, true}]
 
   describe "Kocaptcha" do
     setup do
-      ets_name = Pleroma.Captcha.Kocaptcha.Ets
+      ets_name = Kocaptcha.Ets
       ^ets_name = :ets.new(ets_name, @ets_options)
 
       mock(fn
@@ -23,13 +25,13 @@ defmodule Pleroma.CaptchaTest do
     end
 
     test "new and validate" do
-      assert Pleroma.Captcha.Kocaptcha.new() == %{
+      assert Kocaptcha.new() == %{
                type: :kocaptcha,
                token: "afa1815e14e29355e6c8f6b143a39fa2",
                url: "https://captcha.kotobank.ch/captchas/afa1815e14e29355e6c8f6b143a39fa2.png"
              }
 
-      assert Pleroma.Captcha.Kocaptcha.validate(
+      assert Kocaptcha.validate(
                "afa1815e14e29355e6c8f6b143a39fa2",
                "7oEy8c"
              )