Command:

Validate the S₅  Variant MAC for new terminals

Notes:

Use of this command requires the optional ESP licence. Error code 67 will be returned if the command is not licensed.

Field

Length & Type

Details

COMMAND MESSAGE

Message Header

m A

Will be returned to the Host unchanged

Command Code

2 A

Value “X8”

*KMAC_S5

32 H

Double length KMAC_S5 encrypted under LMK pair 20-21 variant 8

S₅ Variant

16 H

Signature for verification

Length of DD_CEP

1 B

Length of DD_CEP field (range 0 to 16)

Record Length

2 B

Record Length

Record Type

1 B

Record Type

ID_RECORD

2 B

Record number within batch

RID_PSAM

5 B

The RID of the PSAM creator

ID_PSAMCREATOR

4 B

The identifier assigned to the PSAM creator by the RID_PSAM owner

ID_PSAM

4 B

Identifier for a PSAM

ID_BATCH

2 B

Identifier for a POS Transaction Batch

NT_PSAM

4 B

PSAM Transaction Number

MTOT_SIGNED

4 B

Net value of record

CURR_PDA

3 B

Currency of transaction

ID_SCHEME

1 B

Reference number assigned to AID_CEP in AID table

ID_ISS

4 B

Issuer Identifier

ID_CEP

6 B

ID of CEP or IEP application

NT_CEP

2 B

CEP card transaction number

S_6’ or S_6’’

8 B

Signature from CEP card

NT_{ISS, SIGNED}

2 B

Number of transactions accounted for in the signed MTOT in this summary

MTOT_NOSIG

4 B

Unsigned net value of record

NT_{ISS, NOSIG}

4 B

Number of transactions included in unsigned net value

ALG_KS

1 B

Algorithm used to calculate S₄ and S₅ MACs

L_DDCEP

1 B

Length of the DD_CEP field

DD_CEP

N B

DD_CEP response

NUM_SEG

1 B

Number of Segments

End Message Delimiter

1 C

Optional. Must be present if a message trailer is present. Value X'19

Message Trailer

n A

Optional. Maximum length 32 characters

Field

Length & Type

Details

RESPONSE MESSAGE

Message Header

m A

Will be returned to the Host unchanged

Response Code

2 A

Value “X9”

Error Code

2 N

00 – No error. S₅ variant validated successfully

01 – S₅ variant validation failed.

10 – KMAC parity error

12 – No keys loaded in user storage

13 – LMK error - report to Supervisor

15 – Error in input data

21 – Invalid user storage index  

End Message Delimiter

1 C

Will only be present if present in the command message. Value X'19

Message Trailer

n A

Will only be present if in the command message. Maximum length 32 characters