DUKPT Pin Verification IBM method - Error

Oct 17, 2012 at 4:59 PM
Edited Oct 24, 2012 at 7:09 PM

While testing DUKPT, I have the following query.

000000: 00 92 30 30 30 34 47 4f 30 42 45 36 31 41 44 35  ..0004GO0BE61AD5
000010: 37 35 38 41 38 35 31 42 46 36 42 46 34 39 43 38  758A851BF6BF49C8
000020: 45 30 45 38 31 39 39 43 38 36 35 46 31 35 34 36  E0E8199C865F1546
000030: 41 43 31 35 37 38 36 36 32 36 30 35 37 36 39 42  AC1578662605769B
000040: 39 45 30 30 30 41 38 30 30 30 30 31 32 44 36 38  9E000A8000012D68
000050: 32 42 33 32 34 34 39 38 33 46 39 46 30 31 30 34  2B3244983F9F0104
000060: 36 32 34 32 35 30 34 39 35 37 37 36 31 32 33 34  6242504957761234
000070: 35 36 37 38 39 30 31 32 33 34 35 36 34 33 38 36  5678901234564386
000080: 32 34 32 35 30 34 4e 36 31 32 33 34 46 46 46 46  242504N61234FFFF
000090: 46 46 46 46                                                        FFFF



2012-10-23 02:46:00,414: INFO - [XBExtCommPoint] TCPIP Hexdump at receive

000000: 00 08 30 30 30 34 47 50 32 34                    ..0004GP24

24 => PIN is fewer than 4 or more than 12 digits in length

This is for Triple DES pin verification - IBM method.

The data split-up is,

The Header is => 0004
The command code => OG
Mode => '0' ( Pin Verify Only )
BDK ( Encrypted Under LMK ) => BE61AD5758A851BF6BF49C8E0E8199C8
PVK => 65F1546AC1578662
KSN Descriptor => 605 ( I copied this composition from Andy Orrock's site, but I am not sure )
KSN => 769B9E000A800001 ( This composition also I am not sure )
Source Encrypted Pin Block => 2D682B3244983F9F ( Since I don't have PED to test, I used codemagus site tool to generate PIN block )
           Code magus URL is => http://www.codemagus.com/WebTools/cgi-bin/cmldkencrypt
Pin Block format Code => 01
Check Length => 04
Account Number => 624250495776 ( My Pan is 4386242504957766 )
Decimalization Table => 1234567890123456
Pin Validation Data => 4386242504N6
Pin Offset => 1234FFFFFFFF

My Clear PIN is 2449 ( This I generated for PIN offset 1234 in a normal way )

I have created BDK by the following steps:

1. DD
Clear ZMK => 266D B657 896D A46E 8968 519D 206B 1670

2. DE
Enc ZMK => C87E 17F8 EE75 94B5 30DB 22C0 C8BC 9236

3. DG
BDK_ZMK => 99C2 8330 6262 09AA 88E1 AA4E 1A4C 0997
BDK_LMK => BE61 AD57 58A8 51BF 6BF4 9C8E 0E81 99C8

When I decrypt the BDK_ZMK with clear ZMK to feed at PED ( for me it is a web browser )

BDK => 769B9E2A293B5726B976BAC7C7621597

Since I don't have any utility for Single DES DUKPT encryption, I used the codemagus utility with 3DES.

    Can you please help me to find out the reason for this error code 24?

    Please enlighten me on the concepts of KSN and KSN Descriptor.