STATE_UNSYNCD,
STATE_GOT_FALLING_EDGE_OF_SOF,
STATE_AWAITING_START_BIT,
- STATE_RECEIVING_DATA,
- STATE_ERROR_WAIT
+ STATE_RECEIVING_DATA
} state;
uint16_t shiftReg;
int bitCnt;
* Returns: true if we received a EOF
* false if we are still waiting for some more
*/
-static int Handle14443bUartBit(int bit)
+static RAMFUNC int Handle14443bUartBit(uint8_t bit)
{
switch(Uart.state) {
case STATE_UNSYNCD:
} else {
// didn't stay down long enough
// before going high, error
- Uart.state = STATE_ERROR_WAIT;
+ Uart.state = STATE_UNSYNCD;
}
} else {
// do nothing, keep waiting
if(Uart.bitCnt > 12) {
// Give up if we see too many zeros without
// a one, too.
- Uart.state = STATE_ERROR_WAIT;
+ LED_A_OFF();
+ Uart.state = STATE_UNSYNCD;
}
break;
if(Uart.posCnt > 50/2) { // max 57us between characters = 49 1/fs, max 3 etus after low phase of SOF = 24 1/fs
// stayed high for too long between
// characters, error
- Uart.state = STATE_ERROR_WAIT;
+ Uart.state = STATE_UNSYNCD;
}
} else {
// falling edge, this starts the data byte
if(Uart.byteCnt >= Uart.byteCntMax) {
// Buffer overflowed, give up
- Uart.posCnt = 0;
- Uart.state = STATE_ERROR_WAIT;
+ LED_A_OFF();
+ Uart.state = STATE_UNSYNCD;
} else {
// so get the next byte now
Uart.posCnt = 0;
Uart.state = STATE_AWAITING_START_BIT;
}
- } else if(Uart.shiftReg == 0x000) {
+ } else if (Uart.shiftReg == 0x000) {
// this is an EOF byte
LED_A_OFF(); // Finished receiving
+ Uart.state = STATE_UNSYNCD;
if (Uart.byteCnt != 0) {
return TRUE;
}
- Uart.posCnt = 0;
- Uart.state = STATE_ERROR_WAIT;
} else {
// this is an error
- Uart.posCnt = 0;
- Uart.state = STATE_ERROR_WAIT;
+ LED_A_OFF();
+ Uart.state = STATE_UNSYNCD;
}
}
break;
- case STATE_ERROR_WAIT:
- // We're all screwed up, so wait a little while
- // for whatever went wrong to finish, and then
- // start over.
- Uart.posCnt++;
- if(Uart.posCnt > 10) {
- Uart.state = STATE_UNSYNCD;
- LED_A_OFF();
- }
- break;
-
default:
+ LED_A_OFF();
Uart.state = STATE_UNSYNCD;
break;
}
return FALSE;
}
+
+static void UartReset()
+{
+ Uart.byteCntMax = MAX_FRAME_SIZE;
+ Uart.state = STATE_UNSYNCD;
+ Uart.byteCnt = 0;
+ Uart.bitCnt = 0;
+}
+
+
+static void UartInit(uint8_t *data)
+{
+ Uart.output = data;
+ UartReset();
+}
+
+
//-----------------------------------------------------------------------------
// Receive a command (from the reader to us, where we are the simulated tag),
// and store it in the given buffer, up to the given maximum length. Keeps
// Assume that we're called with the SSC (to the FPGA) and ADC path set
// correctly.
//-----------------------------------------------------------------------------
-static int GetIso14443bCommandFromReader(uint8_t *received, int *len, int maxLen)
+static int GetIso14443bCommandFromReader(uint8_t *received, uint16_t *len)
{
- uint8_t mask;
- int i, bit;
-
// Set FPGA mode to "simulated ISO 14443B tag", no modulation (listen
// only, since we are receiving, not transmitting).
// Signal field is off with the appropriate LED
LED_D_OFF();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION);
-
// Now run a `software UART' on the stream of incoming samples.
- Uart.output = received;
- Uart.byteCntMax = maxLen;
- Uart.state = STATE_UNSYNCD;
+ UartInit(received);
for(;;) {
WDT_HIT();
if(BUTTON_PRESS()) return FALSE;
- if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
- AT91C_BASE_SSC->SSC_THR = 0x00;
- }
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-
- mask = 0x80;
- for(i = 0; i < 8; i++, mask >>= 1) {
- bit = (b & mask);
- if(Handle14443bUartBit(bit)) {
+ for(uint8_t mask = 0x80; mask != 0x00; mask >>= 1) {
+ if(Handle14443bUartBit(b & mask)) {
*len = Uart.byteCnt;
return TRUE;
}
}
}
}
+
+ return FALSE;
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void SimulateIso14443bTag(void)
{
- // the only command we understand is REQB, AFI=0, Select All, N=0:
+ // the only commands we understand is REQB, AFI=0, Select All, N=0:
static const uint8_t cmd1[] = { 0x05, 0x00, 0x08, 0x39, 0x73 };
- // ... and we respond with ATQB, PUPI = 820de174, Application Data = 0x20381922,
+ // ... and REQB, AFI=0, Normal Request, N=0:
+ static const uint8_t cmd2[] = { 0x05, 0x00, 0x00, 0x71, 0xFF };
+
+ // ... and we always respond with ATQB, PUPI = 820de174, Application Data = 0x20381922,
// supports only 106kBit/s in both directions, max frame size = 32Bytes,
// supports ISO14443-4, FWI=8 (77ms), NAD supported, CID not supported:
static const uint8_t response1[] = {
0x00, 0x21, 0x85, 0x5e, 0xd7
};
- uint8_t *resp;
- int respLen;
+ clear_trace();
+ set_tracing(TRUE);
+
+ const uint8_t *resp;
+ uint8_t *respCode;
+ uint16_t respLen, respCodeLen;
// allocate command receive buffer
BigBuf_free();
uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
- int len;
-
- int i;
- int cmdsRecvd = 0;
+ uint16_t len;
+ uint16_t cmdsRecvd = 0;
FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
// prepare the (only one) tag answer:
CodeIso14443bAsTag(response1, sizeof(response1));
- uint8_t *resp1 = BigBuf_malloc(ToSendMax);
- memcpy(resp1, ToSend, ToSendMax);
- uint16_t resp1Len = ToSendMax;
+ uint8_t *resp1Code = BigBuf_malloc(ToSendMax);
+ memcpy(resp1Code, ToSend, ToSendMax);
+ uint16_t resp1CodeLen = ToSendMax;
// We need to listen to the high-frequency, peak-detected path.
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
cmdsRecvd = 0;
for(;;) {
- uint8_t b1, b2;
- if(!GetIso14443bCommandFromReader(receivedCmd, &len, 100)) {
+ if(!GetIso14443bCommandFromReader(receivedCmd, &len)) {
Dbprintf("button pressed, received %d commands", cmdsRecvd);
break;
- }
+ }
- // Good, look at the command now.
+ if (tracing) {
+ uint8_t parity[MAX_PARITY_SIZE];
+ LogTrace(receivedCmd, len, 0, 0, parity, TRUE);
+ }
- if(len == sizeof(cmd1) && memcmp(receivedCmd, cmd1, len) == 0) {
- resp = resp1; respLen = resp1Len;
+ // Good, look at the command now.
+ if ( (len == sizeof(cmd1) && memcmp(receivedCmd, cmd1, len) == 0)
+ || (len == sizeof(cmd2) && memcmp(receivedCmd, cmd2, len) == 0) ) {
+ resp = response1;
+ respLen = sizeof(response1);
+ respCode = resp1Code;
+ respCodeLen = resp1CodeLen;
} else {
Dbprintf("new cmd from reader: len=%d, cmdsRecvd=%d", len, cmdsRecvd);
// And print whether the CRC fails, just for good measure
+ uint8_t b1, b2;
ComputeCrc14443(CRC_14443_B, receivedCmd, len-2, &b1, &b2);
if(b1 != receivedCmd[len-2] || b2 != receivedCmd[len-1]) {
// Not so good, try again.
break;
}
- if(respLen <= 0) continue;
+ if(respCodeLen <= 0) continue;
// Modulate BPSK
// Signal field is off with the appropriate LED
FpgaSetupSsc();
// Transmit the response.
- i = 0;
+ uint16_t i = 0;
for(;;) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
- uint8_t b = resp[i];
+ uint8_t b = respCode[i];
AT91C_BASE_SSC->SSC_THR = b;
i++;
- if(i > respLen) {
+ if(i > respCodeLen) {
break;
}
}
(void)b;
}
}
+
+ // trace the response:
+ if (tracing) {
+ uint8_t parity[MAX_PARITY_SIZE];
+ LogTrace(resp, respLen, 0, 0, parity, FALSE);
+ }
+
}
}
DEMOD_AWAITING_FALLING_EDGE_OF_SOF,
DEMOD_GOT_FALLING_EDGE_OF_SOF,
DEMOD_AWAITING_START_BIT,
- DEMOD_RECEIVING_DATA,
- DEMOD_ERROR_WAIT
+ DEMOD_RECEIVING_DATA
} state;
int bitCount;
int posCount;
}
-static void UartReset()
-{
- Uart.byteCntMax = MAX_FRAME_SIZE;
- Uart.state = STATE_UNSYNCD;
- Uart.byteCnt = 0;
- Uart.bitCnt = 0;
-}
-
-
-static void UartInit(uint8_t *data)
-{
- Uart.output = data;
- UartReset();
-}
-
-
/*
* Demodulate the samples we received from the tag, also log to tracebuffer
* quiet: set to 'TRUE' to disable debug output
/* false-triggered by the commands from the reader. */
DemodReset();
}
- ReaderIsActive = (Uart.state != STATE_UNSYNCD);
+ ReaderIsActive = (Uart.state > STATE_GOT_FALLING_EDGE_OF_SOF);
}
if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time
- if(Handle14443bSamplesDemod(ci & 0xFE, cq & 0xFE)) {
+ if(Handle14443bSamplesDemod(ci | 0x01, cq | 0x01)) {
//Use samples as a time measurement
if(tracing)
assign pwr_oe3 = 1'b0;
assign pwr_oe4 = 1'b0;
-(* clock_signal = "yes" *) reg fc_div_2;
+wire adc_clk = ck_1356megb;
+
+reg fc_div_2;
always @(negedge ck_1356megb)
fc_div_2 <= fc_div_2 + 1;
-(* clock_signal = "yes" *) reg adc_clk;
-always @(xcorr_is_848, ck_1356megb, fc_div_2)
-if (xcorr_is_848)
- // The subcarrier frequency is fc/16; we will sample at fc, so that
- // means the subcarrier is 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 ...
- adc_clk <= ck_1356megb;
-else
- // The subcarrier frequency is fc/32; we will sample at fc/2, and
- // the subcarrier will look identical.
- adc_clk <= fc_div_2;
-
-
// When we're a reader, we just need to do the BPSK demod; but when we're an
// eavesdropper, we also need to pick out the commands sent by the reader,
// using AM. Do this the same way that we do it for the simulated tag.
reg ssp_frame;
+always @(negedge adc_clk)
+begin
+ if (xcorr_is_848 | fc_div_2)
+ corr_i_cnt <= corr_i_cnt + 1;
+end
+
// ADC data appears on the rising edge, so sample it on the falling edge
always @(negedge adc_clk)
begin
- corr_i_cnt <= corr_i_cnt + 1;
-
// These are the correlators: we correlate against in-phase and quadrature
// versions of our reference signal, and keep the (signed) result to
// send out later over the SSP.
begin
if(snoop)
begin
- // 7 most significant bits of tag signal (signed), 1 bit reader signal:
+ // Send only 7 most significant bits of tag signal (signed), LSB is reader signal:
corr_i_out <= {corr_i_accum[13:7], after_hysteresis_prev_prev};
corr_q_out <= {corr_q_accum[13:7], after_hysteresis_prev};
after_hysteresis_prev_prev <= after_hysteresis;
projects / proxmark3-svn / commitdiff