Base32 decode about rotp

[mdp]

It's hand rolled to match Google Authenticator's ignoring padding. See #29 and https://code.google.com/p/google-authenticator/source/browse/src/com/google/android/apps/authenticator/Base32String.java?repo=android#101

Most sites stick to using a random string of base32 characters as the secret, usually 16 bytes long (Google) or 24(Dropbox).

Feel free to reopen this if you feel there's a better solution.

[mdp]

Oh, and TOTP.new expects to be passed a string of Base32 characters. Your example above would be double encoding the secret

Base32.encode("dntqoaxas7rvtfuf") #=> "MRXHI4LPMF4GC4ZXOJ3HIZTVMY======"

ROTP::TOTP.new("dntqoaxas7rvtfuf") would be the preferred instantiation in this case and would match the output of most OTP mobile apps sharing this secret.

Hope that helps.