Updates to DESfire support code in #287

Firmware/Chameleon-Mini/Application/DESFire/DESFireISO14443Support.c

@@ -347,7 +347,7 @@ uint16_t ISO144433APiccProcess(uint8_t* Buffer, uint16_t BitCount) {
  Uid[1] = Uid[0];
  Uid[0] = ISO14443A_UID0_CT;
  }
- if (ISO14443ASelect(Buffer, &BitCount, Uid, SAK_CL1_VALUE)) {
+ if (ISO14443ASelectDesfire(Buffer, &BitCount, Uid, SAK_CL1_VALUE)) {
  /* CL1 stage has ended successfully */
  const char *debugPrintStr = PSTR("ISO14443-4: Select OK");
  LogDebuggingMsg(debugPrintStr);
@@ -372,7 +372,7 @@ uint16_t ISO144433APiccProcess(uint8_t* Buffer, uint16_t BitCount) {
  /* Load UID CL2 and perform anticollision */
  ConfigurationUidType Uid;
  ApplicationGetUid(Uid);
- if (ISO14443ASelect(Buffer, &BitCount, &Uid[3], SAK_CL2_VALUE)) {
+ if (ISO14443ASelectDesfire(Buffer, &BitCount, &Uid[3], SAK_CL2_VALUE)) {
  /* CL2 stage has ended successfully. This means
  * our complete UID has been sent to the reader. */
  ISO144433ASwitchState(ISO14443_3A_STATE_ACTIVE);

Firmware/Chameleon-Mini/Application/ISO14443-3A.c

@@ -10,6 +10,10 @@
 #define CRC_INIT 0x6363
 #define CRC_INIT_R 0xC6C6 /* Bit reversed */
 
+#ifdef CONFIG_MF_DESFIRE_SUPPORT
+uint8_t FirstUidCL[4] = { 0 };
+#endif
+
 #define USE_HW_CRC
 
 #ifdef USE_HW_CRC

Firmware/Chameleon-Mini/Application/ISO14443-3A.h

@@ -121,6 +121,80 @@ bool ISO14443ASelect(void *Buffer, uint16_t *BitCount, uint8_t *UidCL, uint8_t S
  }
 }
 
+#ifdef CONFIG_MF_DESFIRE_SUPPORT
+extern uint8_t FirstUidCL[4];
+
+INLINE
+bool ISO14443ASelectDesfire(void* Buffer, uint16_t* BitCount, uint8_t* UidCL, uint8_t SAKValue)
+{
+ uint8_t* DataPtr = (uint8_t*) Buffer;
+ uint8_t NVB = DataPtr[1];
+
+ switch (NVB) {
+ case ISO14443A_NVB_AC_START:
+ /* Start of anticollision procedure.
+ * Send whole UID CLn + BCC */
+ DataPtr[0] = UidCL[0];
+ DataPtr[1] = UidCL[1];
+ DataPtr[2] = UidCL[2];
+ DataPtr[3] = UidCL[3];
+ DataPtr[ISO14443A_CL_BCC_OFFSET] = ISO14443A_CALC_BCC(DataPtr);
+ memcpy(FirstUidCL, UidCL, ISO14443A_CL_UID_SIZE);
+ *BitCount = ISO14443A_CL_FRAME_SIZE;
+ return false;
+
+ case ISO14443A_NVB_AC_END:
+ /* End of anticollision procedure.
+ * Send SAK CLn if we are selected. */
+ if ( (DataPtr[2] == UidCL[0]) &&
+ (DataPtr[3] == UidCL[1]) &&
+ (DataPtr[4] == UidCL[2]) &&
+ (DataPtr[5] == UidCL[3]) ) {
+ DataPtr[0] = SAKValue;
+ *BitCount = BITS_PER_BYTE;
+ return true;
+ }
+ else {
+ /* We have not been selected. Don't send anything. */
+ *BitCount = 0;
+ return false;
+ }
+ default:
+ {
+ uint8_t CollisionByteCount = ((NVB >> 4) & 0x0f) - 2;
+ uint8_t CollisionBitCount = (NVB >> 0) & 0x0f;
+ uint8_t mask = 0xFF >> (8 - CollisionBitCount);
+ // Since the UidCL does not contain the BCC, we have to distinguish here
+ if (
+ ((CollisionByteCount == 5 || (CollisionByteCount == 4 && CollisionBitCount > 0)) &&
+ memcmp(UidCL, &DataPtr[2], 4) == 0 && (ISO14443A_CALC_BCC(UidCL) & mask) == (DataPtr[6] & mask))
+ ||
+ (CollisionByteCount == 4 && CollisionBitCount == 0 && memcmp(UidCL, &DataPtr[2], 4) == 0)
+ ||
+ (CollisionByteCount < 4 && memcmp(UidCL, &DataPtr[2], CollisionByteCount) == 0 &&
+ (UidCL[CollisionByteCount] & mask) == (DataPtr[CollisionByteCount + 2] & mask))
+ )
+ {
+ DataPtr[0] = UidCL[0];
+ DataPtr[1] = UidCL[1];
+ DataPtr[2] = UidCL[2];
+ DataPtr[3] = UidCL[3];
+ DataPtr[4] = ISO14443A_CALC_BCC(DataPtr);
+
+ *BitCount = ISO14443A_CL_FRAME_SIZE;
+ } else {
+ *BitCount = 0;
+ }
+ return false;
+ }
+ /* No anticollision supported */
+ *BitCount = 0;
+ return false;
+ }
+}
+
+#endif
+
 INLINE
 bool ISO14443AWakeUp(void *Buffer, uint16_t *BitCount, uint16_t ATQAValue, bool FromHalt) {
  uint8_t *DataPtr = (uint8_t *) Buffer;