Packet 04: Check Master Key - VeriFone MX800 series Programmer's Manual

Packet 04: Check
Master Key
MS Packet 04 Length:
Table 56 Packet 02 GISKE Key Block Format Communication Protocol
Master Device
<SI>02[r][hhh.hhh]<SO>{LRC}
ACK if LRC, no errors, and key
•
echo okay
NAK if LRC incorrect
•
EOT after 3 NAKs
•
EOT if LRC correct, but key echo
•
incorrect
The master device sends this packet to check if the IPP has a master key stored
at a designated master key address. To avoid an overwrite, this packet must be
sent before sending packet 02 to check that a valid master key is already stored in
the designated address.
Table 57 MS Packet 04 Format
Data Element Characteristic
<SI> 1H
Packet Type 2AN
[a] 1N
<SO> 1H
{LRC} 1H
•
MAX: 6 characters
•
MIN: 6 characters
IPP MS DUKPT C
AND
Transmit
IPP
Direction
ACK if LRC
•
NAK if LRC incorrect
•
EOT after 3 NAKs
•
<SI>02[n]<SO>{LRC}
IPP saves new key only on
•
receipt of ACK
EOT terminates session
•
Comments
Shift In, Value: 0Fh
Value: 04
Master Key address: 0–9
KLK: F
Shift Out, Value: 0Eh
Error Check
X
M 800 S
ERIES
P
OMMUNICATIONS ACKETS
MS-Specific Packets
317
P G
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