How MIFARE Uses Cookies

[onyekachi]

Please my question is not about where you can buy it from, rather to understand what the meaning of the world Emulation means. When it says the card Emulates Desfire EV1, does that mean that you can programme is as Desfire EV1

---

+ 0  |  - 0

[onyekachi]

Thank you for your immediate response.

I guess what I am having problem wrapping my head around is that, according to the spec for NXP.J3D081, the J3D081 Contactless interface emulates MIFARE DESFire EV1 8K (See attachment). My assumption becomes that this card which is a dual interface, shares the same object between the Contact ISO/IEC 7816 specification and the Contactless ISO/IEC 14443 A specification.

I have customers that wants their application to support the 2 specifications and I am of the believe that this NXP.J3D081 Dual Interface with P5CD081 chip is the solution that provide both interfaces.

I know the JCOP is a marketing name, but it seems this card has the SmartMX chip. Please see the attachment and let me know if my assumptions are unfounded

http://www.nxp.com/documents/leaflet/75017515.pdf

https://www.motechno.com/uploads/media/J3D081-JCOP2.4.2.pdf

---

+ 0  |  - 0

[onyekachi]

How about J3D081? I believe that is one of the SmartCards. NXP.J3D081 Dual Interface with P5CD081

---

+ 0  |  - 0

[onyekachi]

What is nit being explained and frankly, not sure why.
Why is no person explaining the inverted bits and which bits are inverted. Anywell, it took me 4 weeks but I do not want the next person 4 hours. So, to add to the explanation from the mifare team

If you have a close look at the figure 10 of the page 12 (mentioned above, with link), you will see the access condition diagram. Please pay attention to bytes 6 and 7. bytes 6 bites are all inverted and there are denoted with line on top of them. Also, notice that bytes 7, C33, C32, C31 and C30 are all inverted.
An invert in this case means that if the calculated bit is 1, it becomes 0. if the calculated bit is 0, it becomes 1.
There is no invert in bytes 8

Bytes 6 C23 C22 C21 C20 C13 C12 C11 C10 Hex
0 0 0 0 1 0 0 0 X08
Bytes 7 C13 C12 C11 C10 C33 C32 C31 C30
0 1 1 1 0 1 1 1 X77
Bytes 8 C33 C32 C31 C30 C23 C22 C21 C20
1 0 0 0 1 1 1 1 X8F

---

+ 0  |  - 0

[onyekachi]

Please help me with the calculation. I have been studying this write-up and explantin for the last 1 week and I believe I got it except that my calculation is coming wrong

Byte 6 is C23 = 1, C22 = 1, C21 = 1, C20 = 1, C13 = 0, C12 = 1, C11 = 1, C10 = 1 -> 11110111 You Have 00001000 [Like are reverse]
Byte 7 is C13 = 0, C12 = 1, C11 = 1, C10 = 1, C33 = 1, C32 = 0, C31 = 0, C30 = 0 -> 01111000 You Have 01110111
Byte 8 is C33 = 1, C32 = 0, C31 = 0, C30 = 0, C23 = 1, C22 = 1, C21 = 1, C20 = 1 -> 10001111 You Have 10001111

This 11110111 01111000 10001111 = F7788F You have 08778F

What am I missing or did not understand?

---

+ 0  |  - 0

[onyekachi]

No option for United State or any Country in North America

See attachment

---

+ 0  |  - 0

[onyekachi]

Steve, I did and I have. but check on sample took purchase, http://www.nfc-tag-shop.de/en/nxp-mifare-sdk-taplinx/24/nfc-nxp-sdk-sample-box-taplinx?c=76, you cannot select United States

How do I get the sample toolkit with the Library?

---

+ 0  |  - 0

[onyekachi]

Thank you very much for your response. What I did not get from the response though, is the support - the Mifare SDK support. Is the support stay the same as it is today or is it going to be different like, for example, a paid support?

---

+ 0  |  - 0

[onyekachi]

Thank you very much for your response - but does Ultralight provide me the capability to initialize (Set) the number of counters (bit). Can I set the counter to 0000 or 0010 myself, or is it pre-set?

---

+ 0  |  - 0

[onyekachi]

Thank you very much for the prompt response,

With the information you provided in-mind, is it possible to prevent one from adding an application to a Desfire card, if they know its a Desfire card and has knowledge of adding application to a card, How does changing the Masterkey prevent one from adding application to the card in anyway?

---

+ 0  |  - 0

[onyekachi]

I saw a response to most of my questions in a previous history https://www.mifare.net/support/forum/topic/set-keys-and-do-authentication-to-desfire-using-mifare-advanced-sdk/

I think the example in the link above was very helpful. I have a follow-up questions though

1> Please explain why its not a good practice to change the whole card default key, Am assuming the master key for default app(0) is the main master key that can be used to reformat the whole card right?

2> in the change key function

 objDESFireEV1.changeKey( 1 , 2, (byte)0x00, 5, (byte)0, DESFire.KeyType.TWOK3DES,



                            IKeyConstants.DIV_OPTION_NODIVERSIFICATION,



                            IKeyConstants.DIV_OPTION_NODIVERSIFICATION, null );



			showMessage( "Card key 1 changed from default to new value", 'd' );

What determines number of keys I have? where was the number of keys defined first before knowing which number to change.

---

+ 0  |  - 0

[onyekachi]

Thanks for your response, based on your response, would you please help me with the comparable Advanced SDK function for the give SDK LIte functions?

1. In SDK LIte, I can perform a function mDESFire.updatePICCMasterKey(piccMasterKey, newPiccMasterKey). Assume the piccMasterKey is the default masterkey and the newpiccMasterKey is the new Key and your converting from DES to AES

I was using the functions mDESFire.changeKey . Is this the correct function? Can you give me a sample argument on how to call it (if its the right function)

2. How do you perform the following SDK Lite function in Advanced?
mDESFire.updateApplicationMasterKey(piccMasterKey, appId, appKey, newAppKey);

---

+ 0  |  - 0

[onyekachi]

Excellent explanation.

Thank you very much for the explanation

---

+ 0  |  - 0

[onyekachi]

Even more confused than I rhought I was.. I am beginning to feel foolish

As a developer that uses the Mifare advanced sdK to devlop application. I have a Mifare card, I have the Mifare Advanced SDK, I have the NFC terminal with SAM slot. I have SD card placed inside the terminal. What else would I need to perform SAM key security and other services provided by Miafre SAM. DO I need to buy the NXP SAM card instead of the regular SD cards. if so, where Do I get it. I live in the United States.

---

+ 0  |  - 0

[onyekachi]

I always has thought SAM Card is a special Secure Device (SD) Card that you buy just like you buy Mifare Cards. What I have understood from your response is that SAM is a regular SD card on a device on your computer that you write a secure element on. Frankly, SAM AV2 is what is written on an SD card, not the special card itself.

---

+ 0  |  - 0

[Author]

Posts