Command Group 0Xennn - Security; Command 0Xe001 - Get Challenge - Magtek DynaFlex II Go Programmer's Manual

6 - Commands
Tag Len
81 var Data being echoed
82 var Data being echoed
End of any wrappers, at minimum including Response Message found on page 33
Table 6.8-3 - Request Example
AA 00 81 04 01 01 DF 01 84 07 DF 01 81 03 01 02 03
Table 6.8-4 - Response Example
AA 00 81 04 82 01 DF 01 82 04 00 00 00 00 84 07 DF 01 81 03 01 02 03
6.9

Command Group 0xEnnn - Security

6.9.1 Command 0xE001 - Get Challenge

The host uses this command to request challenge data from the device, which the host can then use to
perform a specific sensitive operation / modify a specific type of device setting. Information about how
the host should pass the required challenge data to the device is included in the documentation for all
commands that use this security mechanism.
The sequence of events is as follows:
1) The host already wants to perform a secured operation that requires a challenge [for example
Command 0xEEEE - Send Secured Command to Device].
2) The host constructs the command request for Command 0xE001 - Get Challenge in the format
below.
3) The host sends the command request to the device.
4) The device generates a random number for the challenge, stores it locally, and sends a response in the
format below to the host.
5) The device starts a 5 minute countdown timer during which the challenge is valid. If the host takes
no action within 5 minutes, the timer expires, the device erases the challenge data, and the device
must retrieve a fresh challenge to perform the operation it wants to perform. This binding of the
command to a specific time period allows the device to detect and reject commands that have been
captured/intercepted at one point in time and replayed later.
Table 6.9-1 - Request Data for Command 0xE001 - Get Challenge
Tag Len
Beginning of any wrappers, at minimum including Request Message found on page 32
E001 = Command 0xE001 - Get Challenge
81 02 Request ID to be protected
DynaFlex II Go| Secure Card Reader | Programmer's Manual (COMMANDS)
Value / Description
Example (Hex)
Example (Hex)
Value / Description
Page 140 of 301 (D998200597-102)
Typ Req Default
B O
B O
Typ Req Default
B R