Sending a select apdu message to a phone using st25r3911b

[rabinniroula]

I have ported rfal platform to work on my esp32 and have successfully detected all kinds of cards. Now I want to send select APDU message to the phone but I am unsucessful at doing so.

The code I have used:

 

err = rfal_nfc.rfalIsoDepPollAHandleActivation(RFAL_ISODEP_FSXI_512, RFAL_ISODEP_NO_DID, RFAL_BR_424, &isoDepDev);
Serial.print("handle activation: ");
Serial.println(err);

err = rfal_nfc.rfalIsoDepStartApduTransceive(param);
Serial.print("APDU txrx error: ");
Serial.println(err);

if (err == ERR_NONE)
{
 do
 {
 rfal_nfc.rfalNfcWorker();
 err = rfal_nfc.rfalIsoDepGetApduTransceiveStatus();
 Serial.print(".");
 // delay(200);
 Serial.print(err);
 } while (err == ERR_BUSY);
 Serial.println("Received!");
 Serial.println(rxLen);
}

 

The param I've used is:

 

rfalIsoDepApduTxRxParam param;
rfalIsoDepApduBufFormat txapdu;
rfalIsoDepApduBufFormat rxapdu;
rfalIsoDepApduBufFormat temp;
uint16_t rxLen;
txapdu.apdu[0] = SELECT_APDU[0];
txapdu.apdu[1] = SELECT_APDU[1];
txapdu.apdu[2] = SELECT_APDU[2];
txapdu.apdu[3] = SELECT_APDU[3];
txapdu.apdu[4] = SELECT_APDU[4];
txapdu.apdu[5] = SELECT_APDU[5];
txapdu.apdu[6] = SELECT_APDU[6];
txapdu.apdu[7] = SELECT_APDU[7];
txapdu.apdu[8] = SELECT_APDU[8];
txapdu.apdu[9] = SELECT_APDU[9];
txapdu.apdu[10] = SELECT_APDU[10];
txapdu.apdu[11] = SELECT_APDU[11];
txapdu.apdu[12] = SELECT_APDU[12];
param.txBuf = &txapdu;
param.txBufLen = sizeof(txapdu);
param.rxBuf = &rxapdu;
param.rxLen = &rxLen;
param.FWT = isoDepDev.info.FWT;

param.dFWT = isoDepDev.info.dFWT;

param.FSx = RFAL_ISODEP_FSX_KEEP; 

//myParam.FSx = isoDepDevice.info.FSx;

param.DID = isoDepDev.info.DID; 
param.ourFSx = isoDepDev.info.FSx; 

 

The rxLen I get is always 42405. I couldn't find any examples to transceive apdu messages. Can you please help me? Thank you

[rabinniroula]

rfalIsoDepApduTxRxParam param;
rfalIsoDepApduBufFormat txapdu;
rfalIsoDepApduBufFormat rxapdu;
rfalIsoDepApduBufFormat temp;
uint16_t rxLen;
txapdu.apdu[0] = SELECT_APDU[0];
txapdu.apdu[1] = SELECT_APDU[1];
txapdu.apdu[2] = SELECT_APDU[2];
txapdu.apdu[3] = SELECT_APDU[3];
txapdu.apdu[4] = SELECT_APDU[4];
txapdu.apdu[5] = SELECT_APDU[5];
txapdu.apdu[6] = SELECT_APDU[6];
txapdu.apdu[7] = SELECT_APDU[7];
txapdu.apdu[8] = SELECT_APDU[8];
txapdu.apdu[9] = SELECT_APDU[9];
txapdu.apdu[10] = SELECT_APDU[10];
txapdu.apdu[11] = SELECT_APDU[11];
txapdu.apdu[12] = SELECT_APDU[12];
param.txBuf = &txapdu;
param.txBufLen = sizeof(txapdu);
param.rxBuf = &rxapdu;
param.rxLen = &rxLen;
param.FWT = isoDepDev.info.FWT;

param.dFWT = isoDepDev.info.dFWT;

param.FSx = RFAL_ISODEP_FSX_KEEP; 

//myParam.FSx = isoDepDevice.info.FSx;

param.DID = isoDepDev.info.DID; 
param.ourFSx = isoDepDev.info.FSx; 

Is there anything wrong with my param?

[Brian TIDAL]

Hi

when exiting from the do { ... } while (err == ERR_BUSY); loop, the error code is not checked. The rfalIsoDepGetApduTransceiveStatus probably returns an ERR_TIMEOUT due to no response from the tag. When the error code is different from ERR_NONE, the rxLen is not updated and contains probably garbage from the stack.

Can you log the error code when exiting from the do while loop ?

Also, can you print the content of param.txBuf?

Note that rfal_t4t.c provides an rfalT4TPollerCompose API to build the SELECT application, SELECT file, READ BINARY and UPDATE BINARY Commands APDU. 

An example of APDU transceive is available in ndefT4TTransceiveTxRx function in ndef_t4t.c file.

Rgds

BT

[rabinniroula]

 

#include <SPI.h>
#include "rfal_rf.h"
#include "rfal_nfc.h"
#include "rfal_rfst25r3911.h"
#include "ndef_class.h"

// Initialize SPI and RFAL instances
SPIClass dev_spi;
RfalRfST25R3911BClass rfst25r3911b(&dev_spi, 5, 17);
RfalNfcClass rfal_nfc(&rfst25r3911b);
NdefClass ndef(&rfal_nfc);

// Define constants
#define APDU_CMD_LEN 13
uint8_t SELECT_APDU[] = {}; // I can't disclose this for security reasons
ReturnCode err;
void setup() {
 Serial.begin(115200);
 dev_spi.begin();

 // Initialize RFAL
 err = rfal_nfc.rfalNfcInitialize();
 if (err != ERR_NONE) {
 Serial.println("RFAL initialization failed.");
 while (true);
 }
 Serial.println("RFAL Initialized");

 err = rfst25r3911b.rfalFieldOnAndStartGT();
 if (err != ERR_NONE) {
 Serial.println("Field activation failed.");
 while (true);
 }
 Serial.println("Field On");

 pinMode(LED_BUILTIN, OUTPUT);
 digitalWrite(LED_BUILTIN, LOW);
}

void loop() {
 rfal_nfc.rfalNfcWorker(); // RFAL worker

 // Initialize as NFC-A poller
 err = rfal_nfc.rfalNfcaPollerInitialize();
 if (err != ERR_NONE) {
 Serial.println("Poller initialization failed.");
 delay(1000);
 return;
 }
 Serial.println("Poller Initialized");

 // Check for NFC-A tag presence
 rfalNfcaSensRes sensRes;
 err = rfal_nfc.rfalNfcaPollerCheckPresence(RFAL_14443A_SHORTFRAME_CMD_REQA, &sensRes);
 if (err != ERR_NONE) {
 Serial.println("No tag detected.");
 delay(1000);
 return;
 }
 Serial.println("NFC-A tag detected.");

 // Perform collision resolution
 bool collPending = false;
 rfalNfcaSelRes selRes;
 uint8_t nfcId[10];
 uint8_t nfcIdLen;
 err = rfal_nfc.rfalNfcaPollerSingleCollisionResolution(1, &collPending, &selRes, nfcId, &nfcIdLen);
 if (err != ERR_NONE) {
 Serial.println("Collision resolution failed.");
 delay(1000);
 return;
 }
 Serial.print("Tag selected. UID: ");
 for (int i = 0; i < nfcIdLen; i++) {
 Serial.print(nfcId[i], HEX);
 Serial.print(" ");
 }
 Serial.println();

 // Activate device
 rfalIsoDepDevice isoDepDev;
 err = rfal_nfc.rfalIsoDepPollAHandleActivation((rfalIsoDepFSxI)RFAL_ISODEP_FSDI_DEFAULT, RFAL_ISODEP_NO_DID, RFAL_BR_106, &isoDepDev);
 if (err != ERR_NONE) {
 Serial.print("Handle activation error: ");
 Serial.println(err);
 delay(1000);
 return;
 }
 Serial.println("Device activated");

 // Set up APDU parameters
 rfalIsoDepApduTxRxParam param;
 rfalIsoDepApduBufFormat txapdu;
 rfalIsoDepApduBufFormat rxapdu;
 uint16_t rxLen;

 memcpy(txapdu.apdu, SELECT_APDU, sizeof(SELECT_APDU));
 param.txBuf = &txapdu;
 param.txBufLen = sizeof(SELECT_APDU);
 param.rxBuf = &rxapdu;
 param.rxLen = &rxLen;
 param.FWT = isoDepDev.info.FWT;
 param.dFWT = isoDepDev.info.dFWT;
 param.FSx = RFAL_ISODEP_FSX_KEEP;
 param.DID = isoDepDev.info.DID;
 param.ourFSx = isoDepDev.info.FSx;

 Serial.println("Sending APDU...");
 err = rfal_nfc.rfalIsoDepStartApduTransceive(param);
 if (err != ERR_NONE) {
 Serial.print("Error in transceive: ");
 Serial.println(err);
 delay(1000);
 return;
 }

 // Wait for response
 do {
 rfal_nfc.rfalNfcWorker();
 err = rfal_nfc.rfalIsoDepGetApduTransceiveStatus();
 } while (err == ERR_BUSY);

 if (err != ERR_NONE)
 {
 Serial.printf("Error in response: %d \n", err);
 return;
 }

 // if (err != ERR_NONE) {
 // Serial.print("Error receiving APDU response: ");
 // Serial.println(err);
 // } else {
 // Serial.println("APDU Response received:");
 // for (uint8_t i = 0; i < rxLen; i++) {
 // Serial.print(rxapdu.apdu[i], HEX);
 // Serial.print(" ");
 // }
 // Serial.println();
 // }

 // delay(1000); // Add delay between polling attempts
}

This is the full code that I'm using, there's no transceive happening. No response the length of the response is 0. What did I do wrong here?

 

[rabinniroula]

How would i send apdu to multiple detected devices? I believe I should use the rfalIsoDepPollAHandleActivation() function with different DID values. I couldn't find much documentation on DID other than it's used to determine which device to activate and that it's a logical address, could you explain?

[Brian TIDAL]

Hi,

I would suggest to have a dedicated post for this new question.

Rgds

BT