I have succesfully retrieved the CVM List from EMV card.
0000 0000 0000 0000 4103 4203 1E03 1F02
From the EMV specification book 3, the first 4 bytes and second 4 bytes are amount and rest is CV rules. Making these the CV Rule 4103 4203 1E03 1F02
The book also shows how to parse the CV rules, as shown below:
I am assuming that I need to convert the first two bytes in a CV rule to binary and match with the table above? But why does the table above have empty cells? Also can someone explain in a simple pseudo code algorithm to parse this?
Cardholder verification ensures that no third-parties using the card. The card has a Cardholder Verification Method List (CVM List) to inform the terminal wether and which verification methods have to be executed.
Terminal verification results (TVR) or Tag '95' is an EMV data object . The TVR is a series of bits set by the terminal reading an EMV card, based on logical tests (for example has the card expired). This data object is used in the terminal's decision whether to accept, decline or go on-line for a payment transaction.
Consumer Device Cardholder Verification Method (CDCVM) is a type of Cardholder Verification supported by the card networks when accepting contactless transactions originating from mobile devices.
When used on a payment terminal, credit and debit cards can require a cardholder verification method (CVM) to make sure that the person using the card is the legitimate cardholder.
Have you referred section 10.5.5 CVM Processing Logic in the same book ? It has it detailed and even as a flow cart.
As to the empty bits read as RFU.
This is how your sample is parsed.
41 03 41 => 0100 0001 Apply succeeding CV Rule if this CVM is unsuccessful Plaintext PIN verification performed by ICC 03 If terminal supports the CVM --------------------------------------------------- Similarly, 42 03 42 Apply succeeding CV Rule if thisCVM is unsuccessful Enciphered PIN verified online 03 If terminal supports the CVM ---------------------------------------------------- 1E03 1E Signature (paper) 03 If terminal supports the CVM ---------------------------------------------------- 1F 02 1F No CVM required 02 If not unattended cash and not manual cash and not purchase with cashback
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