1 files changed, 45 insertions, 0 deletions
diff --git a/lib/pleroma/web/auth/totp_authenticator.ex b/lib/pleroma/web/auth/totp_authenticator.ex
new file mode 100644
index 000000000..98aca9a51
--- /dev/null
+++ b/lib/pleroma/web/auth/totp_authenticator.ex
@@ -0,0 +1,45 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.Auth.TOTPAuthenticator do
+  alias Comeonin.Pbkdf2
+  alias Pleroma.MFA
+  alias Pleroma.MFA.TOTP
+  alias Pleroma.User
+
+  @doc "Verify code or check backup code."
+  @spec verify(String.t(), User.t()) ::
+          {:ok, :pass} | {:error, :invalid_token | :invalid_secret_and_token}
+  def verify(
+        token,
+        %User{
+          multi_factor_authentication_settings:
+            %{enabled: true, totp: %{secret: secret, confirmed: true}} = _
+        } = _user
+      )
+      when is_binary(token) and byte_size(token) > 0 do
+    TOTP.validate_token(secret, token)
+  end
+
+  def verify(_, _), do: {:error, :invalid_token}
+
+  @spec verify_recovery_code(User.t(), String.t()) ::
+          {:ok, :pass} | {:error, :invalid_token}
+  def verify_recovery_code(
+        %User{multi_factor_authentication_settings: %{enabled: true, backup_codes: codes}} = user,
+        code
+      )
+      when is_list(codes) and is_binary(code) do
+    hash_code = Enum.find(codes, fn hash -> Pbkdf2.checkpw(code, hash) end)
+
+    if hash_code do
+      MFA.invalidate_backup_code(user, hash_code)
+      {:ok, :pass}
+    else
+      {:error, :invalid_token}
+    end
+  end
+
+  def verify_recovery_code(_, _), do: {:error, :invalid_token}
+end