MagTek Bluetooth MagneSafe V5 Swipe Reader - Manual (Page 53)

Section 5. Communications
45
If the reader decrypts Challenge 2 successfully, it will exit the
Authenticated Mode and, depending on the Increment flag, may increment
the KSN.
If the reader cannot decrypt Challenge 2 successfully, it will stay in the
Authenticated Mode until either the time specified in the Activate
Authenticated Mode command passes or the user swipes a card. This
behavior is intended to discourage denial of service attacks. Exiting the
Authenticated Mode by timeout or card swipe always increments the
KSN; exiting Authenticated Mode by the Deactivate Authenticated Mode
command may increment the KSN.
Data structure:
Request Data:
Offset Field Name Description
0 Response to
Challenge 2 Seven bytes of Challenge 2 plus one byte of
Increment flag as outlined above, encrypted by the
specified variant of the current DUKPT Key
Response Data: None
Result codes:
0x00 (Success)
0x02 (Bad Parameters – the Request Data is not a correct length)
0x03 (Bad Data – the encrypted reply data could not be verified)
0x07 (Sequence – not expecting this command)
Example Deactivate Authenticated Mode Request (Hex):
Cmd Num Data Len Data
12 08 8579827521573495
Example Deactivate Authenticated Mode Response (Hex):
Result Code Data Len Data
00 00
GET READER STATE COMMAND
Command Number: 0x14
Description:
This command is used to get the current state of the reader. The state is
returned as two bytes that represent the Current State of the reader and
how it got to that state (Antecedent). For more information see
Reader
States .
Data Structure:
Request Data: None
Response Data: