Is there a way to generate 4 digit code?

[shivanibhanwal]

Hi @robertomiranda,
Thank you for the nice gem. It is really helpful for the OTP generation.
I am using it in my project however we have requirement of 4 digit otp code instead of 6 digit.
Would like to know is there a way to customise it to make it 4 digit or any number of digit?

Another question about Padding a otp code. I have seen that one of the issue has been closed and there has been a pull request. However I am using active_model_otp (1.0.0) version in my project. But still I am getting 5 digit digit some times randomly. And also I did not set any "padding: false"

Is that change related to padding has been published ?

Thanks
Shivani

[robertomiranda]

@shivanibhanwal currently there's not way to specified a length for the code generated, but is something that we can add look https://github.com/mdp/rotp/blob/master/lib/rotp/otp.rb#L14 and would looks like:

class User < ActiveRecord::Base
  has_one_time_password length: 4
end

about your second question, could you paste some code in order to repreduce the issue?. for me is working good

[shivanibhanwal]

Thank you @robertomiranda ! yes I think that would really help as most of the time people use 4 or 6 digit code for OTP
I am planning to make this change If I am done soon will send you a PR
(will make change here -

active_model_otp/lib/active_model/one_time_password.rb

Line 9 in 4ec7c56

self.otp_column_name = (options[:column_name] || "otp_secret_key").to_s

)

[shivanibhanwal]

About the other issue I see code is there in the gem files.
In my case I am not using same User table for the Token. I have separate Auth_tokens table for the token. Also the time drift which we needed that is like few minutes so I have passed drift value.
When I test my app for 1-2 hours after every 10-15 tries I get one OTP which is 5 digit.
And that cause a problem too. when I try to authenticate it it does not authenticate 5 digit otp.

user = self.auth_token
drift_time = Time.now + drift
new_otp = user.otp_code(drift_time)

and this time I got it 3 digit

UPDATE "auth_tokens" SET "otp_code" = 940, "otp_code_expiry" = '2014-08-21 17:11:50.147128' 

Its happening verify frequently

[shivanibhanwal]

@robertomiranda About my second query, Issue was the DataType of the "otp_code" field. I was having it as integer and that was trimming these zero paddings.
I have implemented dynamic length for the otp_code. I have not sent a PR as I am yet to write tests for it.
However you can review my changes here https://github.com/shivanibhanwal/active_model_otp/tree/otp_generation_with_custom_length.

[robertomiranda]

@shivanibhanwal for sure, I'll take a look 👍, but please open the Pull request anyway this can help us to keep and track better the discussion.

[shivanibhanwal]

Sure