VeriFone MX800 Series - Page 321

IPP MS AND DUKPT COMMUNICATIONS PACKETS
MS-Specific Packets
M
X
800 SERIES PROGRAMMERS GUIDE 321
Response Packet
GISKE Block Format
04 Length:
• MAX: 12 characters
• MIN: 12 characters
Response Packet 04
GISKE Block Format
Example:
<SI>040[KUA][MOUA][MACMA][KV][KL]<SO>{LRC}
Mode of Use
Attribute
(MOUA)
1AH (optional) Only if the master key present at
address [a]. The value is stored in the key
attributes register.
• N: No special restrictions [0]
• E: Encryption only [1]
• D: Decryption only [2]
• S: Signature only [3]
• 0: IV [4]
• G: MAC generate [5]
• V: MAC verify [6]
• C: Calculate = generate or verify) [7]
• [6]–[F]: Reserved
Note: To save storage space in RAM, the
mode of use attribute is converted to [x],
a hex number ranging form 0–F (4 bits).
In the response packet (to packet 04),
the IPP converts the hex number back
to characters used in the GISKE
specification.
Key Version
(KV)
2AH (optional) Only if the master key present at
address [a]. The 2-digit ASCII character version
number is optionally used to reinject old keys. If
not used, this field is filled with ASCII 0 (0x30).
Note: The IPP allocates 1 byte per key for
each key version register.
Key Length
(KL)
1AH (optional) Only if the master key present at
address [a].
• 1: single-length key
• 2: double-length key
• 3: triple-length key
Note: The IPP allocates 1 byte per key for
each key version register.
<SO> 1H Shift Out, Value: 0Eh
{LRC} 1H Error Check
Table 60 Response Packet 04 GISKE Key Block Format (Continued)
Data
Element
Characteristic Comments