crewID/libnfc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Fix nfc_initiator_select_passive_target target count on PN53x when not using InListPassiveTarget

Browse source 
When using `pn53x` chip with target not compatible with `InListPassiveTarget` (like `NMT_ISO14443BICLASS`, `NMT_ISO14443B2CT` & `NMT_ISO14443B2SR` by eg.), the logic behind `nfc_initiator_select_passive_target` to return target count seems to be buggy

`nfc_initiator_select_passive_target`:
> Returns:
> Returns selected passive target count on success, otherwise returns libnfc's error code (negative value)

In `pn53x_initiator_select_passive_target_ext`, the return value in success is always `abtTargetsData[0]`. This is correct when using `InListPassiveTarget` as the first byte is `NbTg`, but it can be problematic for other cases.

- Example with a Mifare:
```
gentilkiwi@pi5:~/libnfc-dev $ ./utils/nfc-list -t 1
NFC device: Elechouse NFC Module V3 (SPI) opened

## End of function 'pn53x_initiator_select_passive_target_ext'...
##  abtTargetsData content is : 01 01 00 04 08 04 1a da 74 44
##  return will be:           0x01 (?)

1 ISO14443A passive target(s) found:
ISO/IEC 14443A (106 kbps) target:
    ATQA (SENS_RES): 00  04
       UID (NFCID1): 1a  da  74  44
      SAK (SEL_RES): 08
```

- Example with 2x ST25TB:
```
gentilkiwi@pi5:~/libnfc-dev $ ./utils/nfc-list -t 32
NFC device: Elechouse NFC Module V3 (SPI) opened

## End of function 'pn53x_initiator_select_passive_target_ext'...
##  abtTargetsData content is : 35 a5 f2 a4 68 1f 02 d0
##  return will be:           0x35 (?)

1 ISO14443B-2 ST SRx passive target(s) found:
ISO/IEC 14443-2B ST SRx (106 kbps) target:
                UID: 35  a5  f2  a4  68  1f  02  d0
```
```
gentilkiwi@pi5:~/libnfc-dev $ ./utils/nfc-list -t 32
NFC device: Elechouse NFC Module V3 (SPI) opened

## End of function 'pn53x_initiator_select_passive_target_ext'...
##  abtTargetsData content is : 00 92 f0 a4 68 1f 02 d0
##  return will be:           0x00 (?)

0 ISO14443B-2 ST SRx passive target(s) found.
```

The proposed PR will fix the target count to 1 when not using `InListPassiveTarget`, since current versions of target initialisation do not support for more.

- Results:

```
gentilkiwi@pi5:~/libnfc-dev $ ./utils/nfc-list -t 32
NFC device: Elechouse NFC Module V3 (SPI) opened
1 ISO14443B-2 ST SRx passive target(s) found:
ISO/IEC 14443-2B ST SRx (106 kbps) target:
                UID: 00  92  f0  a4  68  1f  02  d0

gentilkiwi@pi5:~/libnfc-dev $ ./examples/nfc-st25tb
|mode   : info
Reader  : Elechouse NFC Module V3 (SPI) - via pn532_spi:/dev/spidev0.0:500000
  ...wait for card...
Target  : ISO/IEC 14443-2B ST SRx (106 kbps)
UID     : 00 92 f0 a4 68 1f 02 d0
Manuf   : 0x02 - STMicroelectronics
ChipId  : 0x1f - ST25TB04K
Serial  : 0x68a4f09200
|blk sz : 32 bits
|nb blks: 128
|sys idx: 255
```

(also checked for non-regression with `InListPassiveTarget`, including multiples `A` targets)
This commit is contained in:
Benjamin Delpy 2024-07-28 12:36:49 +02:00
parent df0a3beca9
commit 3f0101bd3f
2 changed files with 7 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
examples/nfc-st25tb.c
View file

@ -205,7 +205,8 @@ int main(int argc, char *argv[])
{
printf("Reader : %s - via %s\n ...wait for card...\n", nfc_device_get_name(pnd), nfc_device_get_connstring(pnd));
if (nfc_initiator_select_passive_target(pnd, nm, NULL, 0, &nt) > 0)
res = nfc_initiator_select_passive_target(pnd, nm, NULL, 0, &nt);
if (res > 0)
{
stcurrent = get_info(&nt, true);
if(stcurrent)
@ -234,6 +235,7 @@ int main(int argc, char *argv[])
}
}
}
else printf("ERROR - nfc_initiator_select_passive_target: %i\n", res);
}
else printf("ERROR - nfc_initiator_init: %i\n", res);

5
libnfc/chips/pn53x.c
View file

@ -1267,6 +1267,7 @@ pn53x_initiator_select_passive_target_ext(struct nfc_device *pnd,
szTargetsData = (size_t)res;
}
found = true;
res = 1; // TargetCount to 1 as only one target is supported here
break;
} while (pnd->bInfiniteSelect);
if (! found)
@ -1347,6 +1348,7 @@ pn53x_initiator_select_passive_target_ext(struct nfc_device *pnd,
return res;
}
found = true;
res = 1; // TargetCount to 1 as only one target is supported here
break;
} while (pnd->bInfiniteSelect);
if (! found) {
@ -1377,6 +1379,7 @@ pn53x_initiator_select_passive_target_ext(struct nfc_device *pnd,
return res;
}
}
res = abtTargetsData[0]; // TargetCount to abtTargetsData[0] (Tg from InListPassiveTarget answer)
}
if (pn53x_current_target_new(pnd, &nttmp) == NULL) {
pnd->last_error = NFC_ESOFT;
@ -1386,7 +1389,7 @@ pn53x_initiator_select_passive_target_ext(struct nfc_device *pnd,
if (pnt) {
memcpy(pnt, &nttmp, sizeof(nfc_target));
}
return abtTargetsData[0];
return res;
}
int