Get Key Info - Command 0xEF11

The host uses this command to retrieve information about a key slot, including details about the key stored in that slot. It can be used for several purposes, including:

• Determine if a key exists / has been loaded

• Get key derivation data to derive a DUKPT key

• Get transport key information to retrieve the appropriate transport key

Sequence of events:

1

Construct request

The host constructs the command request in the format below.

2

Send request

The host sends the command request to the device.

3

Receive response

The device sends a response in the format below to the host.

Request Data for Command 0xEF11 - Get Key Info

Tag	Len	Value / Description	Typ	Req	Default
Beginning of any wrappers, at minimum including Request Message
EF11		Get Key Info - Command 0xEF11
81	02	Key Slot ID — See Table XX - Key Slot ID	B	R
End of any wrappers, at minimum including Request Message

Response Data for Command 0xEF11 - Get Key Info

Tag	Len	Value / Description	Typ	Req	Default
EF11 = Get Key Info - Command 0xEF11
81	04	Key Slot Information	B	R
82	06	Loaded Key Information	B	O
/null	(1)	Key Slot Status · 0x00 = Empty · 0x01 = Loaded (Key not assigned purpose) · 0x02 = Loaded & Active · 0x03 = Exhausted (End of DUKPT key sequence · 0x04 = Expired (Reserved, certificate status) 0xFF = Not supported in this device	B	R
/null	(1)	Key Slot Type First byte of the Key Slot ID in the host’s request message.	B	R
/null	(2)	Transport Key Slot ID This specifies the key used to secure and load the key that the host is retrieving information about. See Table 59 - Key Slot ID	B	R
82	06	Loaded Key Information	B	O
/null	(1)	Key Environment — ‘T’ = Test, ‘P’ = Production	A	R
/null	(4)	TR-31 Attributes — See Table XX - TR-31 Key Type Table - Usage/Algorithm/Mode.	B	R
/null	(1)	Encoding of Algorithm & Length: - 0x01 = DEA - 0x02 = 2TDEA - 0x03 = 3TDEA - 0x04 = AES128 - 0x05 = AES192 - 0x06 = AES256	B	R
83	var	Key Check Value: - For AES-CMAC, 5 bytes. - For TDES-CMAC or TDES-CBCMAC, 3 bytes.	B	O
84	var	Key Derivation Information — Contains the derivation block, key serial number (KSN), or key label, as appropriate for the key type.	B	O
A6	var	Restrictions — Reserved. Do not include.	B	O
81	02	DUKPT Restrictions — These restrictions come from the TR-31 block.	B	O
89	var	Timestamp — This comes from the TR-31 block or from device’s real-time clock.	B	O

Request Example - Command 0xEF11

Example (hex)

AA 00 81 04 01 21 EF 11 84 06 EF 11 81 02 20 07

Response Example - Command 0xEF11

Example (hex)

AA 00 81 04 82 21 EF 11 82 04 00 00 00 00 84 34 A2 32 81 04 02 20 10 81 82 06 54 
42 31 54 58 03 84 0A FF FF 98 76 54 32 10 30 00 00 A6 04 81 02 00 3F 89 10 32 30 
32 30 30 39 30 32 54 31 35 35 38 30 32 5A

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