ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
}
+void AppendCrc14443b(uint8_t* data, int len)
+{
+ ComputeCrc14443(CRC_14443_B,data,len,data+len,data+len+1);
+}
+
+
//=============================================================================
// ISO 14443 Type A - Miller decoder
//=============================================================================
static tUart Uart;
// Lookup-Table to decide if 4 raw bits are a modulation.
-// We accept two or three consecutive "0" in any position with the rest "1"
+// We accept the following:
+// 0001 - a 3 tick wide pause
+// 0011 - a 2 tick wide pause, or a three tick wide pause shifted left
+// 0111 - a 2 tick wide pause shifted left
+// 1001 - a 2 tick wide pause shifted right
const bool Mod_Miller_LUT[] = {
- TRUE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, FALSE,
- TRUE, TRUE, FALSE, FALSE, TRUE, FALSE, FALSE, FALSE
+ FALSE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, TRUE,
+ FALSE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
};
-#define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x00F0) >> 4])
-#define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x000F)])
+#define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4])
+#define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)])
void UartReset()
{
Uart.parityLen = 0; // number of decoded parity bytes
Uart.shiftReg = 0; // shiftreg to hold decoded data bits
Uart.parityBits = 0; // holds 8 parity bits
- Uart.twoBits = 0x0000; // buffer for 2 Bits
- Uart.highCnt = 0;
Uart.startTime = 0;
Uart.endTime = 0;
}
{
Uart.output = data;
Uart.parity = parity;
+ Uart.fourBits = 0x00000000; // clear the buffer for 4 Bits
UartReset();
}
static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
{
- Uart.twoBits = (Uart.twoBits << 8) | bit;
+ Uart.fourBits = (Uart.fourBits << 8) | bit;
if (Uart.state == STATE_UNSYNCD) { // not yet synced
- if (Uart.highCnt < 2) { // wait for a stable unmodulated signal
- if (Uart.twoBits == 0xffff) {
- Uart.highCnt++;
- } else {
- Uart.highCnt = 0;
- }
- } else {
- Uart.syncBit = 0xFFFF; // not set
- // we look for a ...1111111100x11111xxxxxx pattern (the start bit)
- if ((Uart.twoBits & 0xDF00) == 0x1F00) Uart.syncBit = 8; // mask is 11x11111 xxxxxxxx,
- // check for 00x11111 xxxxxxxx
- else if ((Uart.twoBits & 0xEF80) == 0x8F80) Uart.syncBit = 7; // both masks shifted right one bit, left padded with '1'
- else if ((Uart.twoBits & 0xF7C0) == 0xC7C0) Uart.syncBit = 6; // ...
- else if ((Uart.twoBits & 0xFBE0) == 0xE3E0) Uart.syncBit = 5;
- else if ((Uart.twoBits & 0xFDF0) == 0xF1F0) Uart.syncBit = 4;
- else if ((Uart.twoBits & 0xFEF8) == 0xF8F8) Uart.syncBit = 3;
- else if ((Uart.twoBits & 0xFF7C) == 0xFC7C) Uart.syncBit = 2;
- else if ((Uart.twoBits & 0xFFBE) == 0xFE3E) Uart.syncBit = 1;
- if (Uart.syncBit != 0xFFFF) { // found a sync bit
- Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
- Uart.startTime -= Uart.syncBit;
- Uart.endTime = Uart.startTime;
- Uart.state = STATE_START_OF_COMMUNICATION;
- }
+ Uart.syncBit = 9999; // not set
+ // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from
+ // Sequence X followed by Sequence Y followed by Sequence Z (111100x1 11111111 00x11111)
+ // we therefore look for a ...xx11111111111100x11111xxxxxx... pattern
+ // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's)
+ #define ISO14443A_STARTBIT_MASK 0x07FFEF80 // mask is 00000111 11111111 11101111 10000000
+ #define ISO14443A_STARTBIT_PATTERN 0x07FF8F80 // pattern is 00000111 11111111 10001111 10000000
+ if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0;
+
+ if (Uart.syncBit != 9999) { // found a sync bit
+ Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
+ Uart.startTime -= Uart.syncBit;
+ Uart.endTime = Uart.startTime;
+ Uart.state = STATE_START_OF_COMMUNICATION;
}
} else {
- if (IsMillerModulationNibble1(Uart.twoBits >> Uart.syncBit)) {
- if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation in both halves - error
+ if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) {
+ if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation in both halves - error
UartReset();
} else { // Modulation in first half = Sequence Z = logic "0"
if (Uart.state == STATE_MILLER_X) { // error - must not follow after X
}
}
} else {
- if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1"
+ if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1"
Uart.bitCount++;
Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg
Uart.state = STATE_MILLER_X;
return TRUE; // we are finished with decoding the raw data sequence
} else {
UartReset(); // Nothing received - start over
- Uart.highCnt = 1;
}
}
if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC
UartReset();
- Uart.highCnt = 1;
} else { // a logic "0"
Uart.bitCount++;
Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
// And ready to receive another response.
DemodReset();
+ // And reset the Miller decoder including itS (now outdated) input buffer
+ UartInit(receivedCmd, receivedCmdPar);
+
LED_C_OFF();
}
TagIsActive = (Demod.state != DEMOD_UNSYNCD);
}
// Only transmit parity bit if we transmitted a complete byte
- if (j == 8) {
+ if (j == 8 && parity != NULL) {
// Get the parity bit
if (parity[i>>3] & (0x80 >> (i&0x0007))) {
// Sequence X
}
}
+
void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing)
{
CodeIso14443aBitsAsReaderPar(frame, bits, par);
}
}
+
void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing)
{
ReaderTransmitBitsPar(frame, len*8, par, timing);
}
+
void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing)
{
// Generate parity and redirect
ReaderTransmitBitsPar(frame, len, par, timing);
}
+
void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing)
{
// Generate parity and redirect
if(param & ISO14A_RAW) {
if(param & ISO14A_APPEND_CRC) {
- AppendCrc14443a(cmd,len);
+ if(param & ISO14A_TOPAZMODE) {
+ AppendCrc14443b(cmd,len);
+ } else {
+ AppendCrc14443a(cmd,len);
+ }
len += 2;
if (lenbits) lenbits += 16;
}
- if(lenbits>0) {
- GetParity(cmd, lenbits/8, par);
- ReaderTransmitBitsPar(cmd, lenbits, par, NULL);
- } else {
- ReaderTransmit(cmd,len, NULL);
+ if(lenbits>0) { // want to send a specific number of bits (e.g. short commands)
+ if(param & ISO14A_TOPAZMODE) {
+ int bits_to_send = lenbits;
+ uint16_t i = 0;
+ ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL); // first byte is always short (7bits) and no parity
+ bits_to_send -= 7;
+ while (bits_to_send > 0) {
+ ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL); // following bytes are 8 bit and no parity
+ bits_to_send -= 8;
+ }
+ } else {
+ GetParity(cmd, lenbits/8, par);
+ ReaderTransmitBitsPar(cmd, lenbits, par, NULL); // bytes are 8 bit with odd parity
+ }
+ } else { // want to send complete bytes only
+ if(param & ISO14A_TOPAZMODE) {
+ uint16_t i = 0;
+ ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL); // first byte: 7 bits, no paritiy
+ while (i < len) {
+ ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL); // following bytes: 8 bits, no paritiy
+ }
+ } else {
+ ReaderTransmit(cmd,len, NULL); // 8 bits, odd parity
+ }
}
arg0 = ReaderReceive(buf, par);
cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
/* And ready to receive another command. */
- UartReset();
+ UartInit(receivedCmd, receivedCmdPar);
/* And also reset the demod code */
DemodReset();
// And ready to receive another response.
DemodReset();
+ // And reset the Miller decoder including its (now outdated) input buffer
+ UartInit(receivedCmd, receivedCmdPar);
}
TagIsActive = (Demod.state != DEMOD_UNSYNCD);
}
projects / proxmark3-svn / blobdiff