Mac-Specific Packets; Mac Packet Z66: Request Mac - VeriFone MX800 series Programmer's Manual

IPP MS DUKPT C
AND OMMUNICATIONS

MAC-Specific Packets

MAC-Specific
Packets
MAC Packet Z66:
Request MAC
336
M X 800 S P
ERIES ROGRAMMERS
P
ACKETS
Table 86 DUKPT Packet 78 Communication Protocol
Master Device
78 Packet
ACK if LRC
•
NAK if LRC incorrect
•
EOT after 3 NAKs
•
This section describes the master-session MAC generation of received message
packets for the IPP. Two packet formats are specified: Z66 and Z67. The detailed
module design and interface design are discussed. ANSI (Standard) MAC
algorithms are used. The following are the packets in this module:
•
Z66: Request MAC
•
Z67: Return MAC
•
72: Cancel MAC Session
Used by the master device to direct the IPP to generate the MAC of the current
packet. If it is the first Z66 packet, the IPP begins MAC generation. If it is the last
Z66 packet, the IPP completes the MAC calculation for current packet, and
returns the MAC to the master device through the Z67 packet. Otherwise, the IPP
calculates the MAC from current packet and stores it in memory.
Table 87 MAC Packet Z66 Format
Data Element Characteristic
<STX> 1H
Packet Type 3AN
[flag] 1N
[sequence] 2N
Master Key 1N
Pointer
<FS> 1H
Working Key 16H
<FS> 1H
G
UIDE
Transmit
IPP
Direction
ACK if LRC
•
NAK if LRC incorrect
•
Packet 75 with PIN = 1234
Comments
Start of text, value: 02h
value: Z66
ANSI (Standard) MAC: ASCII Data: Range: 4–5
4 = the last packet
•
5 = the first/middle packet
•
Binary Data; Range: 6–7
6 = the last packet
•
7 = the first/middle packet
•
Range: 00–99
Optional; Range: 0–9
Field separator, value: 1Ch
Encrypted working key for DES
Field separator, value: 1Ch