Command:

Validate the S₄ MAC (MAC of the PSAM for a Batch) for old 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 “X0”

*KMAC_S4

32 H

Double length KMAC_S4 encrypted under LMK pair 20-21 variant 7

S₄

16 H

Signature for verification

ID_CAD

4 B

Identifier for the CAD

ID_MCARD

4 B

Identifier for the MCard

Collection Number

1 B

Collection Number

MCard Date

1 B

Month number as known by the MCard

MTOT_BATCH

4 B

Total of all successful payments in the batch

CURR_MCARD

2 B

Currency code for the batch

NT_BATCH

2 B

Number of payment records in the batch

NTENQ_BATCH

2 B

Number of successful balance enquiries in the batch

NTREJ_BATCH

2 B

Total number of invalid records in the batch

NTFLT_BATCH

2 B

Number of non-readable ICCs

NTSFLT_BATCH

2 B

Number of system faults

MCard Version

1 B

Firmware version of the MCard

CEXP_MCARD

1 B

Currency exponent

Batch Close Date & Time

2 B

Batch close date and time (may be all a zeroes)

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 “X1”

Error Code

2 N

00 – No error. S₄ validated successfully

01 – S₄ 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