TOTP AUTHENTICATE

Command Description

This command performs a TOTP authentication operation.

Access Condition: PIN, see VERIFY PIN

Note: This only applies to the HID Crescendo key. It does not apply to the HID Crescendo 2300 card.

Command Message

The following table lists the coding for the TOTP AUTHENTICATE command message.

CLA	80h
INS	88h
P1	11h
P2	00h
Lc	Challenge Length
Data Field	Challenge
Le	00h

Data Field Sent in the Command Message

The Data Field contains the Current Unix Time on 32-bits (that is, the number of seconds elapsed since Unix epoch (January 1st, 1970 at UTC)).

For example, for the date 2016, Dec the 13th@ 8:00am, the associated Unix Time is 1481616000 in decimal (or 584FAA80 in hexadecimal), so the following data fields are to be sent:

CD0	58h
CD1	4Fh
CD2	AAh
CD3	80h

Response Message

Data Field Returned in the Response Message

The data field in the response message contains the TOTP authentication code in BCD.

Processing State Returned in the Response Message

Status	Meaning
9000h	Successful execution: No more data available
6700h	Incorrect Lc Parameter: Lc ≠04h
6985	LED of the device blinks to indicate that the device is waiting for the end user to press the button to get the OTP Important: A polling request is required to resend the command until the OTP is returned with 9000.