NFC ndef read write mifare classic tag PN532

[iyosch]

Hello, currently I am working on a project that uses PN532 nfc module from itead. I managed to use the module using I2C and libnfc following this tutorial : http://blog.iteadstudio.com/raspberry-p ... th-libnfc/

I can read the UID, ATQA, and SAK from my NFC tag. But I don't really know what ATQA and SAK means and how can I change the value of those things?

I also want to know how to read and write the ndef message on my nfc tag. How can I do that? Do libnfc capable of doing that?
I have done some research on this website http://www.libnfc.org/api/examples_page.html but I don't really understand all of them. I've tried every example program provided by the lib-nfc, the only one working is nfc-poll and quick_start_example1 and 2 which is actually doing the same thing as the nfc-poll.

Can anyone help?

Edit 2015-08-07 :
i have done searching all over the web so far this is what i have found useful
http://matt.bionicmessage.net/blog/2010 ... h%20course
it looks like this guy successfully authenticate the key to read the data block for NFC card but this guy is using different files/library not from libnfc
so i modified the quick_start_example1.c from libnfc (libnfc-1.7.1/examples/doc/quick_start_example1.c) and i make this new code

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/**
 * @file quick_start_example1.c
 * @brief Quick start example that presents how to use libnfc
 */
 
/**
 * this code is edited from quick_start_example1
 * this code doesnt work.
 */

// To compile this simple example:
// $ gcc -o quick_start_example1 quick_start_example1.c -lnfc

#include <stdlib.h>
#include <nfc/nfc.h> //located on libnfc-1.7.1/include/nfc/nfc.h
#include <string.h>
//#include <nfc/nfc-types.h> //located on libnfc-1.7.1/include/nfc/nfc-types.h
#include </home/pi/libnfc-1.7.1/utils/mifare.h>

static mifare_param mp; //addition
nfc_target_info nti; //declare nfc_target_info as nti for ease of use
nfc_device *pnd;



//declaring keys 6x8 = 48 bit
static uint8_t keys[] = {
        0xff,0xff,0xff,0xff,0xff,0xff,
        0xd3,0xf7,0xd3,0xf7,0xd3,0xf7,
        0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,
        0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,
        0x4d,0x3a,0x99,0xc3,0x51,0xdd,
        0x1a,0x98,0x2c,0x7e,0x45,0x9a,
        0xaa,0xbb,0xcc,0xdd,0xee,0xff,
        0x00,0x00,0x00,0x00,0x00,0x00
};


//function to authenticate
static bool
authenticate(int block, int keynum, bool keyB) {
        memcpy(mp.mpa.abtAuthUid,nti.nai.abtUid,4);
        memcpy(mp.mpa.abtKey, &keys[keynum], 6);
        
        bool res = nfc_initiator_mifare_cmd(pnd, (keyB ? MC_AUTH_B : MC_AUTH_A), block, &mp);
        if (res) {
                printf("Authentication succcessful on block %d\n",block);
        } else {
                printf("Authentication failed on block %d\n",block);
        }
        return res;
}


//function to readblock
void readblocks(int start, int end) {
        int block;
        for (block=start; block<(end+1); block++) {
                bool res = nfc_initiator_mifare_cmd(pnd, MC_READ, block, &mp);
                if (res) {
                        printf("Block %d data: ",block);
                        //print_hex(mp.mpd.abtData,16);
                } else {
                        printf("Reading block %d failed\n",block);
                }
        }
}


//function print_hex to show data on terminal
static void print_hex(const uint8_t *pbtData, const size_t szBytes)
{
  size_t  szPos;

  for (szPos = 0; szPos < szBytes; szPos++) {
    printf("%02x  ", pbtData[szPos]);
  }
  printf("\n");
}

//function main
int
main(int argc, const char *argv[])
{
  //nfc_device *pnd; //this initialization is moved to the top of the file
  nfc_target nt;
  
  // Allocate only a pointer to nfc_context
  nfc_context *context;

  // Initialize libnfc and set the nfc_context
  nfc_init(&context);
  if (context == NULL) {
    printf("Unable to init libnfc (malloc)\n");
    exit(EXIT_FAILURE);
  }

  // Display libnfc version
  const char *acLibnfcVersion = nfc_version();
  (void)argc;
  printf("%s uses libnfc %s\n", argv[0], acLibnfcVersion);

  // Open, using the first available NFC device which can be in order of selection:
  //   - default device specified using environment variable or
  //   - first specified device in libnfc.conf (/etc/nfc) or
  //   - first specified device in device-configuration directory (/etc/nfc/devices.d) or
  //   - first auto-detected (if feature is not disabled in libnfc.conf) device
  pnd = nfc_open(context, NULL);

  if (pnd == NULL) {
    printf("ERROR: %s\n", "Unable to open NFC device.");
    exit(EXIT_FAILURE);
  }
  // Set opened NFC device to initiator mode
  if (nfc_initiator_init(pnd) < 0) {
    nfc_perror(pnd, "nfc_initiator_init");
    exit(EXIT_FAILURE);
  }

  printf("NFC reader: %s opened\n", nfc_device_get_name(pnd));

  // Poll for a ISO14443A (MIFARE) tag
  const nfc_modulation nmMifare = {
    .nmt = NMT_ISO14443A,
    .nbr = NBR_106,
  };
  if (nfc_initiator_select_passive_target(pnd, nmMifare, NULL, 0, &nt) > 0) {
    printf("The following (NFC) ISO14443A tag was found:\n");
    printf("    ATQA (SENS_RES): ");
    print_hex(nt.nti.nai.abtAtqa, 2);
    printf("       UID (NFCID%c): ", (nt.nti.nai.abtUid[0] == 0x08 ? '3' : '1'));
    print_hex(nt.nti.nai.abtUid, nt.nti.nai.szUidLen);
    printf("      SAK (SEL_RES): ");
    print_hex(&nt.nti.nai.btSak, 1);
    if (nt.nti.nai.szAtsLen) {
      printf("          ATS (ATR): ");
      print_hex(nt.nti.nai.abtAts, nt.nti.nai.szAtsLen);
    }
    
    //try to read blocks
        } else {
                goto DISCONNECT;
        }
        // Try to login to sector 0. Use the default key FFFF, for key A
        bool authenticated = authenticate(3,0,false);
        
        if (!authenticated) {
                goto DISCONNECT;
        }
        
        readblocks(0,3); //read block 0 untill 3 (4 blocks)
        
        DISCONNECT: 
        // Disconnect from NFC device
        nfc_disconnect(pnd);
        return EXIT_SUCCESS;
        
    
    //compare the UID from nt.nti.nai.abtUid with stored UID
    const uint8_t winner[] = { 0x9e, 0x74, 0x03, 0x0a};
        if (memcmp(nt.nti.nai.abtUid, winner, 4) == 0) {
            printf("UID matched\n");
        }
    //nt.nti.nai.abtUid
    //nt = nfc_target
    //nti = nfc_target info
    //nai =  nfc_iso14443a_info nai <- all this is set on nfc-types.h
    //abtUid = UID of the nfc tag
        
    //template of memcmp 
    //int memcmp(const void *str1, const void *str2, size_t n)
    
    //try to read the data block
    //template to read data block
    //uint8_t mifareclassic_ReadDataBlock (uint8_t blockNumber, uint8_t * data);
    
    //print the ats
    printf("         Test ATS : ");
    print_hex(nt.nti.nai.abtAts, 254);
    
    //print dep info
    printf("         DEP abtNFCID3 : ");
    print_hex(nt.nti.ndi.abtNFCID3 , 11);    

    
  // Close NFC device
  nfc_close(pnd);
  // Release the context
  nfc_exit(context);
  exit(EXIT_SUCCESS);
}

this code can't be compiled, i don't know why. i use the command :

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gcc -o quick_start_example4 quick_start_example4.c -lnfc

but then i got into error

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/usr/bin/ld:cannot find -lnfc
collect2: ld returned 1 exit status

can anyone help?

Edit 2015-07-09
Turns out there is something wrong with the script i use to compile the code. I changed it with my script that has been successful to compile quick_start_example3.c and now the quick_start_example4.c doesn't show

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/usr/bin/ld:cannot find -lnfc

that error anymore. But changed into this

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/tmp/cc3wcb4X.o: In function `authenticate':
quick_start_example3.c:(.text+0xa0): undefined reference to `nfc_initiator_mifare_cmd'
/tmp/cc3wcb4X.o: In function `readblocks':
quick_start_example3.c:(.text+0x144): undefined reference to `nfc_initiator_mifare_cmd'
/tmp/cc3wcb4X.o: In function `main':
quick_start_example3.c:(.text+0x498): undefined reference to `nfc_disconnect'
collect2: ld returned 1 exit status

Edit 2015-08-05:
Turns out we can read mifare classic tag PN532 using libnfc-1.7.1
after setting up from http://blog.iteadstudio.com/raspberry-p ... th-libnfc/
we can create hex dump file using this :

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nfc-mfclassic r b dump.mfd

nfc-mfclassic r b dump.mfd
r means read, b means using key b, dump.mfd is a file created containing sectors, blocks, keys, and data stored on the card
we read the .mfd filetypes using command

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xxd dump.mfd

if the linux don't have xxd, install it using

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sudo apt-get install xxd

Now, how can we read ndef from nfc mifare classic just like we do on android smartphone easily?

[GartZen]

Hi,

First nfc_disconnect has been replaced by nfc_close.
About nfc_initiator_mifare_cmd, this function is available in the mifare.c, just compile wih mifare.c (see in utils folder of libnfc-1.7.1) should be enough.

[iyosch]

thank you for your reply. turns out we can use nfc-mfclassic provided by libnfc-1.7.1 to read the NFC mifare classic. I didn't see it untill now. We can type

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nfc-mfclassic r b dump.mfd

r means read, b means using key b, dump.mfd is a file created containing sectors, blocks, keys, and data stored on the card
read the .mfd filetypes using command

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xxd dump.mfd

I will update my post.

Is there any easier method to read and write ndef message NFC mifare classic 4k ?

[engrkhawaja]

Hi,

I am working of similar sort of thing. The code following this tuotorial http://matt.bionicmessage.net/blog/2010 ... h%20course
is being compiled and build. It can read the tag ID as in nfc-poll and display the tag info. But it cannot authenticate the block sector.

I would appreciate if you could help me to solve this.

Also if you found solution to ndef read data then please also inform me about it.

Looking Forward

[topguy]

It can read the tag ID as in nfc-poll and display the tag info. But it cannot authenticate the block sector.

I would appreciate if you could help me to solve this.

Do you know the key(s) for the sector you are trying to read or are you guessing ? Is the card blank or has some other application written to it.

[iyosch]

i am guessing that you are not using a clean or new nfc card/tag. in that case you might try using mfoc
follow this : https://www.youtube.com/watch?v=BDO84uO ... ck%20keys"

source :
https://github.com/nfc-tools/mfoc
install using :
(on download directory)
git clone https://github.com/nfc-tools/mfoc
cd mfoc
autoreconf -vis
./configure
make
sudo make install
sudo ldconfig

then you can run
mfoc -h or place an nfc card then mfoc -P 500 -O keyFileDump.mfd

you will get a keydumpfile.mfd which contains the same key as the card. now you can use it along with
the program "nfc-mfclassic" from libnfc along with the keydumpfile.mfd that you get from mfoc. at the moment i am still searching on how to modify the keys and the value of each block data. hope that helps.