ErrInvalidConfig signals that an invalid configuration was provided.

ErrNilOTPProvider signals that a nil otp provider was provided.

ErrNilRateLimiter signals that a nil rate limiter was provided.

ErrRegistrationFailed signals that registration failed.

OTP defines the methods available for a one time password provider.

OTPProvider defines the methods available for an otp provider.

SecureOtpHandler defines the methods available for a secure otp handler.

ShardedStorageFactory defines the methods available for a sharded storage factory.

TOTPHandler defines the methods available for a time based one time password handler.