How MIFARE Uses Cookies

[David92]

Hi,

1) I am not sure as to why it is not. I think you should change your DEFAULT MASTER KEY to something what you want, otherwise everyone who detects that you use DESFire will first try to authenticate with DEFAULT MASTER KEY, which means, that person can erase your card or even do other changes if you weren't carefull.

2) You determine the number of keys you have during application creation procedure in KeySettingsTwo --> check the JavaDoc you'll notice it. Once you create an application with 5 keys (for example) they are all 00's. Once you apply changeKey method, they will change to the keys you defined in KeyStore.

Hope it helps.
David

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[David92]

Hi,

I just want to say here, that formatKeyEntry and setKey has NOTHING to do with the PICC (Card)!
When you create an application on DESFire and you specify that the application will have for example 5 keys AES. The card saves 5 AES keys with all 0's on it.

KeyStore is a SOFTWARE part. You use it just to store the keys temporary for easier access (via keyNumber).

If you want to apply changes to the card, do it after personalization. Then you need to call command changeKey(). Now, this will infact change the key on the card with they key in the KeyStore.


Also to your previous post:
Make sure that once you used formatKeyEntry() you also used the same slot (keyNo) and the same AuthType(AES) as in the setKey() method.

A bit confusing, but I hope you understand.

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[David92]

What exactly is not working in your case ? Can you specify the LOC ?

NOTE: Whilre creating a file on DESFire, you had to specify keys which grant you different access: Read, Write. Once you select the application you have to authenticate with a READ KEY (same one as you used during creating that file) and then you can read the file.

Best,
David

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[David92]

Hi,

You could first try to "connect" with the card, once you detect it: plus.getReader().connect();
If that does not help, please write which line is reporting the error inside your code.

Best,
David

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[David92]

Hi,
Did this Error resolve ? Maybe there was an issue with the Server.

Best,
David

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[David92]

Hi Philip,

I did not check you code, but from reading your post, first thing that came to my mind is, that your NFC Controller inside your phone does not recognize your MF Classic as classic card and confuses it with some other TAG / CARD, and throws you that error.

But this is a wide guess, when I will have more time, I will try to look into this one.

Best,
David

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[David92]

Hello Greg,

Yes that is true. SSG S4 has a broadcom chip inside it, which causes some issues with certain MIFARE cards. As you mentioned there are issues with MIFARE Classic not being detected. But there might be also some wrong detection with the particular SmartPhone, for e.g. Ultralight getting detected as NTAG. For the latter I am not sure.

Best,
David

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[David92]

Hey,

From what I know, the above answer is not really correct.

When a user will use your Android App that has imported the nxpnfcliblite inside it, the user will be prompted to register the App with one-time only activation (which requires internet connection, with this one we track the usage of LITE version in the field - for the statistics of SDK Lite downloads / usages in app).

Currently there is no possible way to delay this or to have a pre-activated lib, but in future some solutions might pop-up to remove the warning messages / pre-activate the lib. If you control the 5 devices you mention, you could run the App once with internet connection and then put in the field - that way you have your app registered and will work without warning. If you do not have control of the devices that will use your App, then unfortunately the only way to go is to activate it once with Internet Connection.

Hope I could explain it well for you, if I'm mistaken, please correct me.

Best,
David

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[David92]

No problem Greg.
Just let me know if there's still an issue with SampleApp working with Android Studio as this is important for us.

Best,
David

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[David92]

When did you try to download it ?
Because there is a newer version of LITE SDK uploaded since 3 days ago and the Sample App should be now Android Studio compatible.
Please let me know if this is not the case.

David

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[David92]

Hello,

I am not sure of which Tags are we speaking about, so I will assume you mean NTag.
With the SDK there's no direct method to check "isPwdProtected()", but probably you could try to use some other methods within SDK, and if it throws you an exception, like "authentication error", then you know it's password protected, because it tells you you need to authenticate wit PWD.

If you are interested perhaps in pages withing NTags, there is a method to check "isPageLocked()" where you input the Address an it will return you a boolean, True for locked, false for not-locked.

Hope I could help you a bit.
If there's something I did not get quite alright, please try to be more specific.

Best,
David

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[David92]

Hello Philip,

Your scenario described above definetly implies that your Android Device has NFC Controller that is unable to detect Classic Card.
Establishing connection with android native commands to the card does not mean that your phone now detects MF Classic.
As you can see soon after sending some APDUs you are reciving exception "TagLost", this happens also on my Galaxy S4, which has Broadcom controller in it.

I would really love to see, if you can manage to borromw from some a Nexus 7, or some other Android Device that has NXP NFC Controller.
Just to really put a dot at the end of our statements - because we know are guessing that NFC Controller is the issue here.

Best,
David

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[David92]

Hey Phillip,

I was trying to find out information on your NFC Controller used in your Device, but I could not find the info.
The reason is, that non-NXP NFC controllers might not recognize Classic Card or have issues with detecting it.

For example my Samsung Galaxy S4 cannot detect MF Classic Card, because I have a BROADCOM NFC Controller inside it,
but the same card works perfeclty on my NEXUS 7 Tablet, because it has NXP NFC Controller in it.

I would suggest first to determine if this is the possible issue, what you can do:

- Figure out your NFC controller, which one it is
- Try your App / Sample App on another Android Device that has NXP NFC Controller in it and see what happens if you tap the same card you use to it

Then we will be able to narrow down reasons why is this happening. Because currently I see only these options:

- You do not have a real MIFARE Classic card
- You have a non-NXP NFC controller chip inside your Android Device
- OR COULD be possible bug in your software (but this one I doubt since SDK is working for me, for example)

Lets see what you find out.

Best,
David

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[David92]

Hey Philip,

Could you tell me what Android device are using for your App ?
And if you have any Error / Warnings in LogCat of your Android Studio or in Eclipse ?

Best,
David

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[David92]

Hey Christopher,
The 80h represents BCC = Block Check Character, which is calculated as Exclusive OR over the last 4 bytes.

Best,
David

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