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diff --git a/lib/pleroma/mfa/totp.ex b/lib/pleroma/mfa/totp.ex
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+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.MFA.TOTP do
+  @moduledoc """
+  This module represents functions to create secrets for
+  TOTP Application as well as validate them with a time based token.
+  """
+  alias Pleroma.Config
+
+  @config_ns [:instance, :multi_factor_authentication, :totp]
+
+  @doc """
+  https://github.com/google/google-authenticator/wiki/Key-Uri-Format
+  """
+  def provisioning_uri(secret, label, opts \\ []) do
+    query =
+      %{
+        secret: secret,
+        issuer: Keyword.get(opts, :issuer, default_issuer()),
+        digits: Keyword.get(opts, :digits, default_digits()),
+        period: Keyword.get(opts, :period, default_period())
+      }
+      |> Enum.filter(fn {_, v} -> not is_nil(v) end)
+      |> Enum.into(%{})
+      |> URI.encode_query()
+
+    %URI{scheme: "otpauth", host: "totp", path: "/" <> label, query: query}
+    |> URI.to_string()
+  end
+
+  defp default_period, do: Config.get(@config_ns ++ [:period])
+  defp default_digits, do: Config.get(@config_ns ++ [:digits])
+
+  defp default_issuer,
+    do: Config.get(@config_ns ++ [:issuer], Config.get([:instance, :name]))
+
+  @doc "Creates a random Base 32 encoded string"
+  def generate_secret do
+    Base.encode32(:crypto.strong_rand_bytes(10))
+  end
+
+  @doc "Generates a valid token based on a secret"
+  def generate_token(secret) do
+    :pot.totp(secret)
+  end
+
+  @doc """
+  Validates a given token based on a secret.
+
+  optional parameters:
+  `token_length` default `6`
+  `interval_length` default `30`
+  `window` default 0
+
+  Returns {:ok, :pass} if the token is valid and
+  {:error, :invalid_token} if it is not.
+  """
+  @spec validate_token(String.t(), String.t()) ::
+          {:ok, :pass} | {:error, :invalid_token | :invalid_secret_and_token}
+  def validate_token(secret, token)
+      when is_binary(secret) and is_binary(token) do
+    opts = [
+      token_length: default_digits(),
+      interval_length: default_period()
+    ]
+
+    validate_token(secret, token, opts)
+  end
+
+  def validate_token(_, _), do: {:error, :invalid_secret_and_token}
+
+  @doc "See `validate_token/2`"
+  @spec validate_token(String.t(), String.t(), Keyword.t()) ::
+          {:ok, :pass} | {:error, :invalid_token | :invalid_secret_and_token}
+  def validate_token(secret, token, options)
+      when is_binary(secret) and is_binary(token) do
+    case :pot.valid_totp(token, secret, options) do
+      true -> {:ok, :pass}
+      false -> {:error, :invalid_token}
+    end
+  end
+
+  def validate_token(_, _, _), do: {:error, :invalid_secret_and_token}
+end