OneTimePassEcto

One-time password library for apps using Ecto.

Installation

OneTimePassEcto can be installed by adding one_time_pass_ecto to your list of dependencies in mix.exs:

Usage

Step 1

Add this to your mix.exs file

def deps do
  [{:one_time_pass_ecto, "~> 1.0"}]
end

Step 2

Read the module implementation details

Step 3

OTPs smaller than 6 digits return false when checking them using OneTimePassEcto.Base.check_totp/3 and OneTimePassEcto.Base.check_hotp/3

Using Time-based One Time Passwords(TOTP).

iex> secret = OneTimePassEcto.Base.gen_secret(32) # Default secret length is 16
"ZOMPHX3LA5IM64A66RG6YW7ATUFO5D5G"
iex> OneTimePassEcto.Base.gen_totp(s, [{:interval_length, 300}]) # The library generates 6 digit OTP
"679648"
iex> OneTimePassEcto.Base.check_totp("123456", secret, [interval_length: 300]) # Testing a wrong OTP
false
iex> OneTimePassEcto.Base.check_totp("679648", s, [interval_length: 300]) # You can pass token_length in the keyword list. 6 is its default value
5160711 # This is the 'last' value

Using HMAC-based One Time Passwords

iex> secret = OneTimePassEcto.Base.gen_secret(32) # Default secret length is 16
"WXEXLDA6YKUH7CRHU66OGO43JB7SIUF7"
iex> OneTimePassEcto.Base.gen_hotp(secret, 5, [token_length: 6])
"444385"
iex> OneTimePassEcto.Base.check_hotp("354532", secret)
false
iex> OneTimePassEcto.Base.check_hotp("444385", s, [window: 400]) # Set the 'window' in keyword list otherwise you may receive false even with correct OTP
32

Step 4

OneTimePassEcto.verify/4 can help you persist your generated OTPs in Ecto-supported DBs of your choice. The params map is either %{"id" => id, "hotp" => otp} or %{"id" => id, "totp" => otp}, where otp is your generated OTP and hotp/totp identify the type.