Generate a MAC on a Binary Message

Command:

Generate a MAC on a binary message.

Notes:

If the Host is unable to support binary data transfers, the command can be used in standard (ASCII character) asynchronous mode (in which the message to be MACed is transferred in expanded hexadecimal notation).

 

Field

Length & Type

Details

COMMAND MESSAGE

Message header

m A

(Subsequently returned to the Host unchanged).

Command code

2 A

Value MU.

Mode number

1 N

The MAC calculation mode number: 0 to 3.

0:  The only block.

1:  The first block.

2:  A middle block.

3:  The last block

Terminal authentication key

16H or 1A+32H or 1A+48H

TAK encrypted under LMK pair 16-17.

Initialization vector

16 H

Modes 2,3. IV returned from either mode 1 or 2 encrypted under variant 1 of LMK pair 16-17.

EITHER

For Binary Communications Modes:

Message length

3 H

X’001 to X’320 indicating the length of the next field.

Message text

n B

1 to 800 bytes of message.

OR

For Standard Async Communications Mode:

Message length

3 H

X’002 to X’320 indicating the number of characters in the next field.

Message text

n H

2 to 800 hexadecimal characters representing 1 to 400 bytes of message.

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

n A

Returned to the Host unchanged.

Response code

2 A

Value MV.

Error code

2 N

00 : No errors

10 : TAK 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

27 : TAK not single length

80 : Message length error (including odd number of

       characters when using standard async mode)

90 : Communications link parity error

91 : Communications link LRC error

92 : Transparent async data length error

IV

16 H

Present only in modes 1 and 2. The IV encrypted under variant 1 of LMK pair 16-17.

MAC

8 H

Present only in modes 0 and 3.

End message delimiter

1 C

Present only if present in the command message. Value X’19.

Message trailer

n A

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