Symmetrically encrypt backup codes with user password & attr_encrypted about devise-two-factor HOT 3 CLOSED

Added in #73 and #76

from devise-two-factor.

@f3ndot Can you give an example of how to use attr_encrypted with otp_backup_codes so that it can be displayed to user anytime?

from devise-two-factor.

@melbreaker should be as simple as:

Class User

 # ...

  attribute :otp_backup_codes # Needed for Rails 5. Remove once attr_encrypted releases their fix. See attr-encrypted/attr_encrypted#263
  attr_encrypted :otp_backup_codes, key: Rails.application.secrets.two_factor_auth[:otp_encryption_key]

 # ...

end

Note you probably don't want to show the backup codes to the user without first prompting them for a password.

from devise-two-factor.