1 //-----------------------------------------------------------------------------
2 // Jonathan Westhues, split Nov 2006
5 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
6 // at your option, any later version. See the LICENSE.txt file for the text of
8 //-----------------------------------------------------------------------------
9 // Routines to support ISO 14443B. This includes both the reader software and
10 // the `fake tag' modes.
11 //-----------------------------------------------------------------------------
13 #include "proxmark3.h"
18 #include "iso14443crc.h"
20 #define RECEIVE_SAMPLES_TIMEOUT 1000 // TR0 max is 256/fs = 256/(848kHz) = 302us or 64 samples from FPGA. 1000 seems to be much too high?
21 #define ISO14443B_DMA_BUFFER_SIZE 128
23 // PCB Block number for APDUs
24 static uint8_t pcb_blocknum
= 0;
26 //=============================================================================
27 // An ISO 14443 Type B tag. We listen for commands from the reader, using
28 // a UART kind of thing that's implemented in software. When we get a
29 // frame (i.e., a group of bytes between SOF and EOF), we check the CRC.
30 // If it's good, then we can do something appropriate with it, and send
32 //=============================================================================
34 //-----------------------------------------------------------------------------
35 // Code up a string of octets at layer 2 (including CRC, we don't generate
36 // that here) so that they can be transmitted to the reader. Doesn't transmit
37 // them yet, just leaves them ready to send in ToSend[].
38 //-----------------------------------------------------------------------------
39 static void CodeIso14443bAsTag(const uint8_t *cmd
, int len
)
45 // Transmit a burst of ones, as the initial thing that lets the
46 // reader get phase sync. This (TR1) must be > 80/fs, per spec,
47 // but tag that I've tried (a Paypass) exceeds that by a fair bit,
49 for(i
= 0; i
< 20; i
++) {
57 for(i
= 0; i
< 10; i
++) {
63 for(i
= 0; i
< 2; i
++) {
70 for(i
= 0; i
< len
; i
++) {
81 for(j
= 0; j
< 8; j
++) {
104 for(i
= 0; i
< 10; i
++) {
110 for(i
= 0; i
< 2; i
++) {
117 // Convert from last byte pos to length
121 //-----------------------------------------------------------------------------
122 // The software UART that receives commands from the reader, and its state
124 //-----------------------------------------------------------------------------
128 STATE_GOT_FALLING_EDGE_OF_SOF
,
129 STATE_AWAITING_START_BIT
,
140 /* Receive & handle a bit coming from the reader.
142 * This function is called 4 times per bit (every 2 subcarrier cycles).
143 * Subcarrier frequency fs is 848kHz, 1/fs = 1,18us, i.e. function is called every 2,36us
146 * LED A -> ON once we have received the SOF and are expecting the rest.
147 * LED A -> OFF once we have received EOF or are in error state or unsynced
149 * Returns: true if we received a EOF
150 * false if we are still waiting for some more
152 static RAMFUNC
int Handle14443bUartBit(uint8_t bit
)
157 // we went low, so this could be the beginning
159 Uart
.state
= STATE_GOT_FALLING_EDGE_OF_SOF
;
165 case STATE_GOT_FALLING_EDGE_OF_SOF
:
167 if(Uart
.posCnt
== 2) { // sample every 4 1/fs in the middle of a bit
169 if(Uart
.bitCnt
> 9) {
170 // we've seen enough consecutive
171 // zeros that it's a valid SOF
174 Uart
.state
= STATE_AWAITING_START_BIT
;
175 LED_A_ON(); // Indicate we got a valid SOF
177 // didn't stay down long enough
178 // before going high, error
179 Uart
.state
= STATE_UNSYNCD
;
182 // do nothing, keep waiting
186 if(Uart
.posCnt
>= 4) Uart
.posCnt
= 0;
187 if(Uart
.bitCnt
> 12) {
188 // Give up if we see too many zeros without
191 Uart
.state
= STATE_UNSYNCD
;
195 case STATE_AWAITING_START_BIT
:
198 if(Uart
.posCnt
> 50/2) { // max 57us between characters = 49 1/fs, max 3 etus after low phase of SOF = 24 1/fs
199 // stayed high for too long between
201 Uart
.state
= STATE_UNSYNCD
;
204 // falling edge, this starts the data byte
208 Uart
.state
= STATE_RECEIVING_DATA
;
212 case STATE_RECEIVING_DATA
:
214 if(Uart
.posCnt
== 2) {
215 // time to sample a bit
218 Uart
.shiftReg
|= 0x200;
222 if(Uart
.posCnt
>= 4) {
225 if(Uart
.bitCnt
== 10) {
226 if((Uart
.shiftReg
& 0x200) && !(Uart
.shiftReg
& 0x001))
228 // this is a data byte, with correct
229 // start and stop bits
230 Uart
.output
[Uart
.byteCnt
] = (Uart
.shiftReg
>> 1) & 0xff;
233 if(Uart
.byteCnt
>= Uart
.byteCntMax
) {
234 // Buffer overflowed, give up
236 Uart
.state
= STATE_UNSYNCD
;
238 // so get the next byte now
240 Uart
.state
= STATE_AWAITING_START_BIT
;
242 } else if (Uart
.shiftReg
== 0x000) {
243 // this is an EOF byte
244 LED_A_OFF(); // Finished receiving
245 Uart
.state
= STATE_UNSYNCD
;
246 if (Uart
.byteCnt
!= 0) {
252 Uart
.state
= STATE_UNSYNCD
;
259 Uart
.state
= STATE_UNSYNCD
;
267 static void UartReset()
269 Uart
.byteCntMax
= MAX_FRAME_SIZE
;
270 Uart
.state
= STATE_UNSYNCD
;
276 static void UartInit(uint8_t *data
)
283 //-----------------------------------------------------------------------------
284 // Receive a command (from the reader to us, where we are the simulated tag),
285 // and store it in the given buffer, up to the given maximum length. Keeps
286 // spinning, waiting for a well-framed command, until either we get one
287 // (returns true) or someone presses the pushbutton on the board (false).
289 // Assume that we're called with the SSC (to the FPGA) and ADC path set
291 //-----------------------------------------------------------------------------
292 static int GetIso14443bCommandFromReader(uint8_t *received
, uint16_t *len
)
294 // Set FPGA mode to "simulated ISO 14443B tag", no modulation (listen
295 // only, since we are receiving, not transmitting).
296 // Signal field is off with the appropriate LED
298 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR
| FPGA_HF_SIMULATOR_NO_MODULATION
);
300 // Now run a `software UART' on the stream of incoming samples.
306 if(BUTTON_PRESS()) return false;
308 if(AT91C_BASE_SSC
->SSC_SR
& (AT91C_SSC_RXRDY
)) {
309 uint8_t b
= (uint8_t)AT91C_BASE_SSC
->SSC_RHR
;
310 for(uint8_t mask
= 0x80; mask
!= 0x00; mask
>>= 1) {
311 if(Handle14443bUartBit(b
& mask
)) {
322 //-----------------------------------------------------------------------------
323 // Main loop of simulated tag: receive commands from reader, decide what
324 // response to send, and send it.
325 //-----------------------------------------------------------------------------
326 void SimulateIso14443bTag(void)
328 // the only commands we understand is WUPB, AFI=0, Select All, N=1:
329 static const uint8_t cmd1
[] = { 0x05, 0x00, 0x08, 0x39, 0x73 }; // WUPB
330 // ... and REQB, AFI=0, Normal Request, N=1:
331 static const uint8_t cmd2
[] = { 0x05, 0x00, 0x00, 0x71, 0xFF }; // REQB
333 static const uint8_t cmd3
[] = { 0x50, 0xff, 0xff, 0xff, 0xff }; // HLTB
335 static const uint8_t cmd4
[] = { 0x1D, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; // ATTRIB
337 // ... and we always respond with ATQB, PUPI = 820de174, Application Data = 0x20381922,
338 // supports only 106kBit/s in both directions, max frame size = 32Bytes,
339 // supports ISO14443-4, FWI=8 (77ms), NAD supported, CID not supported:
340 static const uint8_t response1
[] = {
341 0x50, 0x82, 0x0d, 0xe1, 0x74, 0x20, 0x38, 0x19, 0x22,
342 0x00, 0x21, 0x85, 0x5e, 0xd7
344 // response to HLTB and ATTRIB
345 static const uint8_t response2
[] = {0x00, 0x78, 0xF0};
348 FpgaDownloadAndGo(FPGA_BITSTREAM_HF
);
355 uint16_t respLen
, respCodeLen
;
357 // allocate command receive buffer
359 uint8_t *receivedCmd
= BigBuf_malloc(MAX_FRAME_SIZE
);
362 uint16_t cmdsRecvd
= 0;
364 // prepare the (only one) tag answer:
365 CodeIso14443bAsTag(response1
, sizeof(response1
));
366 uint8_t *resp1Code
= BigBuf_malloc(ToSendMax
);
367 memcpy(resp1Code
, ToSend
, ToSendMax
);
368 uint16_t resp1CodeLen
= ToSendMax
;
370 // prepare the (other) tag answer:
371 CodeIso14443bAsTag(response2
, sizeof(response2
));
372 uint8_t *resp2Code
= BigBuf_malloc(ToSendMax
);
373 memcpy(resp2Code
, ToSend
, ToSendMax
);
374 uint16_t resp2CodeLen
= ToSendMax
;
376 // We need to listen to the high-frequency, peak-detected path.
377 SetAdcMuxFor(GPIO_MUXSEL_HIPKD
);
378 FpgaSetupSsc(FPGA_MAJOR_MODE_HF_SIMULATOR
);
384 if(!GetIso14443bCommandFromReader(receivedCmd
, &len
)) {
385 Dbprintf("button pressed, received %d commands", cmdsRecvd
);
389 LogTrace(receivedCmd
, len
, 0, 0, NULL
, true);
391 // Good, look at the command now.
392 if ( (len
== sizeof(cmd1
) && memcmp(receivedCmd
, cmd1
, len
) == 0)
393 || (len
== sizeof(cmd2
) && memcmp(receivedCmd
, cmd2
, len
) == 0) ) {
395 respLen
= sizeof(response1
);
396 respCode
= resp1Code
;
397 respCodeLen
= resp1CodeLen
;
398 } else if ( (len
== sizeof(cmd3
) && receivedCmd
[0] == cmd3
[0])
399 || (len
== sizeof(cmd4
) && receivedCmd
[0] == cmd4
[0]) ) {
401 respLen
= sizeof(response2
);
402 respCode
= resp2Code
;
403 respCodeLen
= resp2CodeLen
;
405 Dbprintf("new cmd from reader: len=%d, cmdsRecvd=%d", len
, cmdsRecvd
);
406 // And print whether the CRC fails, just for good measure
408 if (len
>= 3){ // if crc exists
409 ComputeCrc14443(CRC_14443_B
, receivedCmd
, len
-2, &b1
, &b2
);
410 if(b1
!= receivedCmd
[len
-2] || b2
!= receivedCmd
[len
-1]) {
411 // Not so good, try again.
412 DbpString("+++CRC fail");
415 DbpString("CRC passes");
418 //get rid of compiler warning
422 respCode
= resp1Code
;
423 //don't crash at new command just wait and see if reader will send other new cmds.
429 if(cmdsRecvd
> 0x30) {
430 DbpString("many commands later...");
434 if(respCodeLen
<= 0) continue;
437 // Signal field is off with the appropriate LED
439 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR
| FPGA_HF_SIMULATOR_MODULATE_BPSK
);
440 AT91C_BASE_SSC
->SSC_THR
= 0xff;
441 FpgaSetupSsc(FPGA_MAJOR_MODE_HF_SIMULATOR
);
443 // Transmit the response.
446 if(AT91C_BASE_SSC
->SSC_SR
& (AT91C_SSC_TXRDY
)) {
447 uint8_t b
= respCode
[i
];
449 AT91C_BASE_SSC
->SSC_THR
= b
;
452 if(i
> respCodeLen
) {
456 if(AT91C_BASE_SSC
->SSC_SR
& (AT91C_SSC_RXRDY
)) {
457 volatile uint8_t b
= (uint8_t)AT91C_BASE_SSC
->SSC_RHR
;
462 // trace the response:
463 LogTrace(resp
, respLen
, 0, 0, NULL
, false);
468 //=============================================================================
469 // An ISO 14443 Type B reader. We take layer two commands, code them
470 // appropriately, and then send them to the tag. We then listen for the
471 // tag's response, which we leave in the buffer to be demodulated on the
473 //=============================================================================
478 DEMOD_PHASE_REF_TRAINING
,
479 DEMOD_AWAITING_FALLING_EDGE_OF_SOF
,
480 DEMOD_GOT_FALLING_EDGE_OF_SOF
,
481 DEMOD_AWAITING_START_BIT
,
487 /* this had been used to add RSSI (Received Signal Strength Indication) to traces. Currently not implemented.
499 * Handles reception of a bit from the tag
501 * This function is called 2 times per bit (every 4 subcarrier cycles).
502 * Subcarrier frequency fs is 848kHz, 1/fs = 1,18us, i.e. function is called every 4,72us
505 * LED C -> ON once we have received the SOF and are expecting the rest.
506 * LED C -> OFF once we have received EOF or are unsynced
508 * Returns: true if we received a EOF
509 * false if we are still waiting for some more
512 static RAMFUNC
int Handle14443bSamplesDemod(int ci
, int cq
)
516 // The soft decision on the bit uses an estimate of just the
517 // quadrant of the reference angle, not the exact angle.
518 #define MAKE_SOFT_DECISION() { \
519 if(Demod.sumI > 0) { \
524 if(Demod.sumQ > 0) { \
531 #define SUBCARRIER_DETECT_THRESHOLD 8
533 // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq)))
534 #define AMPLITUDE(ci,cq) (MAX(ABS(ci),ABS(cq)) + (MIN(ABS(ci),ABS(cq))/2))
535 switch(Demod
.state
) {
537 if(AMPLITUDE(ci
,cq
) > SUBCARRIER_DETECT_THRESHOLD
) { // subcarrier detected
538 Demod
.state
= DEMOD_PHASE_REF_TRAINING
;
545 case DEMOD_PHASE_REF_TRAINING
:
546 if(Demod
.posCount
< 8) {
547 if (AMPLITUDE(ci
,cq
) > SUBCARRIER_DETECT_THRESHOLD
) {
548 // set the reference phase (will code a logic '1') by averaging over 32 1/fs.
549 // note: synchronization time > 80 1/fs
553 } else { // subcarrier lost
554 Demod
.state
= DEMOD_UNSYNCD
;
557 Demod
.state
= DEMOD_AWAITING_FALLING_EDGE_OF_SOF
;
561 case DEMOD_AWAITING_FALLING_EDGE_OF_SOF
:
562 MAKE_SOFT_DECISION();
563 if(v
< 0) { // logic '0' detected
564 Demod
.state
= DEMOD_GOT_FALLING_EDGE_OF_SOF
;
565 Demod
.posCount
= 0; // start of SOF sequence
567 if(Demod
.posCount
> 200/4) { // maximum length of TR1 = 200 1/fs
568 Demod
.state
= DEMOD_UNSYNCD
;
574 case DEMOD_GOT_FALLING_EDGE_OF_SOF
:
576 MAKE_SOFT_DECISION();
578 if(Demod
.posCount
< 9*2) { // low phase of SOF too short (< 9 etu). Note: spec is >= 10, but FPGA tends to "smear" edges
579 Demod
.state
= DEMOD_UNSYNCD
;
581 LED_C_ON(); // Got SOF
582 Demod
.state
= DEMOD_AWAITING_START_BIT
;
585 /* this had been used to add RSSI (Received Signal Strength Indication) to traces. Currently not implemented.
591 if(Demod
.posCount
> 12*2) { // low phase of SOF too long (> 12 etu)
592 Demod
.state
= DEMOD_UNSYNCD
;
598 case DEMOD_AWAITING_START_BIT
:
600 MAKE_SOFT_DECISION();
602 if(Demod
.posCount
> 3*2) { // max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs
603 Demod
.state
= DEMOD_UNSYNCD
;
606 } else { // start bit detected
608 Demod
.posCount
= 1; // this was the first half
611 Demod
.state
= DEMOD_RECEIVING_DATA
;
615 case DEMOD_RECEIVING_DATA
:
616 MAKE_SOFT_DECISION();
617 if(Demod
.posCount
== 0) { // first half of bit
620 } else { // second half of bit
623 /* this had been used to add RSSI (Received Signal Strength Indication) to traces. Currently not implemented.
624 if(Demod.thisBit > 0) {
625 Demod.metric += Demod.thisBit;
627 Demod.metric -= Demod.thisBit;
632 Demod
.shiftReg
>>= 1;
633 if(Demod
.thisBit
> 0) { // logic '1'
634 Demod
.shiftReg
|= 0x200;
638 if(Demod
.bitCount
== 10) {
639 uint16_t s
= Demod
.shiftReg
;
640 if((s
& 0x200) && !(s
& 0x001)) { // stop bit == '1', start bit == '0'
641 uint8_t b
= (s
>> 1);
642 Demod
.output
[Demod
.len
] = b
;
644 Demod
.state
= DEMOD_AWAITING_START_BIT
;
646 Demod
.state
= DEMOD_UNSYNCD
;
649 // This is EOF (start, stop and all data bits == '0'
659 Demod
.state
= DEMOD_UNSYNCD
;
668 static void DemodReset()
670 // Clear out the state of the "UART" that receives from the tag.
672 Demod
.state
= DEMOD_UNSYNCD
;
674 memset(Demod
.output
, 0x00, MAX_FRAME_SIZE
);
678 static void DemodInit(uint8_t *data
)
686 * Demodulate the samples we received from the tag, also log to tracebuffer
687 * quiet: set to 'true' to disable debug output
689 static void GetSamplesFor14443bDemod(int n
, bool quiet
)
692 bool gotFrame
= false;
693 int lastRxCounter
, samples
= 0;
696 // Allocate memory from BigBuf for some buffers
697 // free all previous allocations first
700 // The response (tag -> reader) that we're receiving.
701 uint8_t *receivedResponse
= BigBuf_malloc(MAX_FRAME_SIZE
);
703 // The DMA buffer, used to stream samples from the FPGA
704 uint16_t *dmaBuf
= (uint16_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE
* sizeof(uint16_t));
706 // Set up the demodulator for tag -> reader responses.
707 DemodInit(receivedResponse
);
709 // wait for last transfer to complete
710 while (!(AT91C_BASE_SSC
->SSC_SR
& AT91C_SSC_TXEMPTY
))
712 // Setup and start DMA.
713 FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER_RX_XCORR
);
714 FpgaSetupSscDma((uint8_t*) dmaBuf
, ISO14443B_DMA_BUFFER_SIZE
);
716 uint16_t *upTo
= dmaBuf
;
717 lastRxCounter
= ISO14443B_DMA_BUFFER_SIZE
;
719 // Signal field is ON with the appropriate LED:
721 // And put the FPGA in the appropriate mode
722 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR
| FPGA_HF_READER_RX_XCORR_848_KHZ
);
725 int behindBy
= (lastRxCounter
- AT91C_BASE_PDC_SSC
->PDC_RCR
) & (ISO14443B_DMA_BUFFER_SIZE
-1);
726 if(behindBy
> maxBehindBy
) {
727 maxBehindBy
= behindBy
;
730 if(behindBy
< 1) continue;
736 if(upTo
>= dmaBuf
+ ISO14443B_DMA_BUFFER_SIZE
) { // we have read all of the DMA buffer content.
737 upTo
= dmaBuf
; // start reading the circular buffer from the beginning
738 lastRxCounter
+= ISO14443B_DMA_BUFFER_SIZE
;
740 if (AT91C_BASE_SSC
->SSC_SR
& (AT91C_SSC_ENDRX
)) { // DMA Counter Register had reached 0, already rotated.
741 AT91C_BASE_PDC_SSC
->PDC_RNPR
= (uint32_t) dmaBuf
; // refresh the DMA Next Buffer and
742 AT91C_BASE_PDC_SSC
->PDC_RNCR
= ISO14443B_DMA_BUFFER_SIZE
; // DMA Next Counter registers
746 if(Handle14443bSamplesDemod(ci
, cq
)) {
758 if (!quiet
) Dbprintf("max behindby = %d, samples = %d, gotFrame = %d, Demod.len = %d, Demod.sumI = %d, Demod.sumQ = %d", maxBehindBy
, samples
, gotFrame
, Demod
.len
, Demod
.sumI
, Demod
.sumQ
);
761 LogTrace(Demod
.output
, Demod
.len
, 0, 0, NULL
, false);
766 //-----------------------------------------------------------------------------
767 // Transmit the command (to the tag) that was placed in ToSend[].
768 //-----------------------------------------------------------------------------
769 static void TransmitFor14443b(void)
773 FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER_TX
);
775 // Signal field is ON with the appropriate Red LED
777 // Signal we are transmitting with the Green LED
779 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX
| FPGA_HF_READER_TX_SHALLOW_MOD
);
783 if(AT91C_BASE_SSC
->SSC_SR
& (AT91C_SSC_TXRDY
)) {
784 AT91C_BASE_SSC
->SSC_THR
= ~ToSend
[c
];
792 LED_B_OFF(); // Finished sending
796 //-----------------------------------------------------------------------------
797 // Code a layer 2 command (string of octets, including CRC) into ToSend[],
798 // so that it is ready to transmit to the tag using TransmitFor14443b().
799 //-----------------------------------------------------------------------------
800 static void CodeIso14443bAsReader(const uint8_t *cmd
, int len
)
808 for(i
= 0; i
< 10; i
++) {
814 for(i
= 0; i
< len
; i
++) {
819 for(j
= 0; j
< 8; j
++) {
832 for(i
= 0; i
< 10; i
++) {
837 // ensure that last byte is filled up
838 for(i
= 0; i
< 8; i
++) {
842 // Convert from last character reference to length
848 Convenience function to encode, transmit and trace iso 14443b comms
850 static void CodeAndTransmit14443bAsReader(const uint8_t *cmd
, int len
)
852 CodeIso14443bAsReader(cmd
, len
);
854 LogTrace(cmd
,len
, 0, 0, NULL
, true);
857 /* Sends an APDU to the tag
858 * TODO: check CRC and preamble
860 int iso14443b_apdu(uint8_t const *message
, size_t message_length
, uint8_t *response
)
862 uint8_t message_frame
[message_length
+ 4];
864 message_frame
[0] = 0x0A | pcb_blocknum
;
867 message_frame
[1] = 0;
869 memcpy(message_frame
+ 2, message
, message_length
);
871 ComputeCrc14443(CRC_14443_B
, message_frame
, message_length
+ 2, &message_frame
[message_length
+ 2], &message_frame
[message_length
+ 3]);
873 CodeAndTransmit14443bAsReader(message_frame
, message_length
+ 4);
875 GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT
, true);
881 // copy response contents
884 memcpy(response
, Demod
.output
, Demod
.len
);
889 /* Perform the ISO 14443 B Card Selection procedure
890 * Currently does NOT do any collision handling.
891 * It expects 0-1 cards in the device's range.
892 * TODO: Support multiple cards (perform anticollision)
893 * TODO: Verify CRC checksums
895 int iso14443b_select_card()
897 // WUPB command (including CRC)
898 // Note: WUPB wakes up all tags, REQB doesn't wake up tags in HALT state
899 static const uint8_t wupb
[] = { 0x05, 0x00, 0x08, 0x39, 0x73 };
900 // ATTRIB command (with space for CRC)
901 uint8_t attrib
[] = { 0x1D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00};
903 // first, wake up the tag
904 CodeAndTransmit14443bAsReader(wupb
, sizeof(wupb
));
905 GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT
, true);
913 // copy the PUPI to ATTRIB
914 memcpy(attrib
+ 1, Demod
.output
+ 1, 4);
915 /* copy the protocol info from ATQB (Protocol Info -> Protocol_Type) into
917 attrib
[7] = Demod
.output
[10] & 0x0F;
918 ComputeCrc14443(CRC_14443_B
, attrib
, 9, attrib
+ 9, attrib
+ 10);
919 CodeAndTransmit14443bAsReader(attrib
, sizeof(attrib
));
920 GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT
, true);
921 // Answer to ATTRIB too short?
926 // reset PCB block number
931 // Set up ISO 14443 Type B communication (similar to iso14443a_setup)
932 void iso14443b_setup() {
933 FpgaDownloadAndGo(FPGA_BITSTREAM_HF
);
934 // Set up the synchronous serial port
935 FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER_TX
);
936 // connect Demodulated Signal to ADC:
937 SetAdcMuxFor(GPIO_MUXSEL_HIPKD
);
939 // Signal field is on with the appropriate LED
941 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX
| FPGA_HF_READER_TX_SHALLOW_MOD
);
947 //-----------------------------------------------------------------------------
948 // Read a SRI512 ISO 14443B tag.
950 // SRI512 tags are just simple memory tags, here we're looking at making a dump
951 // of the contents of the memory. No anticollision algorithm is done, we assume
952 // we have a single tag in the field.
954 // I tried to be systematic and check every answer of the tag, every CRC, etc...
955 //-----------------------------------------------------------------------------
956 void ReadSTMemoryIso14443b(uint32_t dwLast
)
960 FpgaDownloadAndGo(FPGA_BITSTREAM_HF
);
961 // Make sure that we start from off, since the tags are stateful;
962 // confusing things will happen if we don't reset them between reads.
964 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF
);
967 SetAdcMuxFor(GPIO_MUXSEL_HIPKD
);
968 FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER_RX_XCORR
);
970 // Now give it time to spin up.
971 // Signal field is on with the appropriate LED
973 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR
| FPGA_HF_READER_RX_XCORR_848_KHZ
);
979 // First command: wake up the tag using the INITIATE command
980 uint8_t cmd1
[] = {0x06, 0x00, 0x97, 0x5b};
981 CodeAndTransmit14443bAsReader(cmd1
, sizeof(cmd1
));
982 GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT
, true);
984 if (Demod
.len
== 0) {
985 DbpString("No response from tag");
987 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF
);
990 Dbprintf("Randomly generated Chip ID (+ 2 byte CRC): %02x %02x %02x",
991 Demod
.output
[0], Demod
.output
[1], Demod
.output
[2]);
994 // There is a response, SELECT the uid
995 DbpString("Now SELECT tag:");
996 cmd1
[0] = 0x0E; // 0x0E is SELECT
997 cmd1
[1] = Demod
.output
[0];
998 ComputeCrc14443(CRC_14443_B
, cmd1
, 2, &cmd1
[2], &cmd1
[3]);
999 CodeAndTransmit14443bAsReader(cmd1
, sizeof(cmd1
));
1000 GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT
, true);
1001 if (Demod
.len
!= 3) {
1002 Dbprintf("Expected 3 bytes from tag, got %d", Demod
.len
);
1004 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF
);
1007 // Check the CRC of the answer:
1008 ComputeCrc14443(CRC_14443_B
, Demod
.output
, 1 , &cmd1
[2], &cmd1
[3]);
1009 if(cmd1
[2] != Demod
.output
[1] || cmd1
[3] != Demod
.output
[2]) {
1010 DbpString("CRC Error reading select response.");
1012 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF
);
1015 // Check response from the tag: should be the same UID as the command we just sent:
1016 if (cmd1
[1] != Demod
.output
[0]) {
1017 Dbprintf("Bad response to SELECT from Tag, aborting: %02x %02x", cmd1
[1], Demod
.output
[0]);
1019 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF
);
1023 // Tag is now selected,
1024 // First get the tag's UID:
1026 ComputeCrc14443(CRC_14443_B
, cmd1
, 1 , &cmd1
[1], &cmd1
[2]);
1027 CodeAndTransmit14443bAsReader(cmd1
, 3); // Only first three bytes for this one
1028 GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT
, true);
1029 if (Demod
.len
!= 10) {
1030 Dbprintf("Expected 10 bytes from tag, got %d", Demod
.len
);
1032 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF
);
1035 // The check the CRC of the answer (use cmd1 as temporary variable):
1036 ComputeCrc14443(CRC_14443_B
, Demod
.output
, 8, &cmd1
[2], &cmd1
[3]);
1037 if(cmd1
[2] != Demod
.output
[8] || cmd1
[3] != Demod
.output
[9]) {
1038 Dbprintf("CRC Error reading block! Expected: %04x got: %04x",
1039 (cmd1
[2]<<8)+cmd1
[3], (Demod
.output
[8]<<8)+Demod
.output
[9]);
1040 // Do not return;, let's go on... (we should retry, maybe ?)
1042 Dbprintf("Tag UID (64 bits): %08x %08x",
1043 (Demod
.output
[7]<<24) + (Demod
.output
[6]<<16) + (Demod
.output
[5]<<8) + Demod
.output
[4],
1044 (Demod
.output
[3]<<24) + (Demod
.output
[2]<<16) + (Demod
.output
[1]<<8) + Demod
.output
[0]);
1046 // Now loop to read all 16 blocks, address from 0 to last block
1047 Dbprintf("Tag memory dump, block 0 to %d", dwLast
);
1053 DbpString("System area block (0xff):");
1057 ComputeCrc14443(CRC_14443_B
, cmd1
, 2, &cmd1
[2], &cmd1
[3]);
1058 CodeAndTransmit14443bAsReader(cmd1
, sizeof(cmd1
));
1059 GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT
, true);
1060 if (Demod
.len
!= 6) { // Check if we got an answer from the tag
1061 DbpString("Expected 6 bytes from tag, got less...");
1063 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF
);
1066 // The check the CRC of the answer (use cmd1 as temporary variable):
1067 ComputeCrc14443(CRC_14443_B
, Demod
.output
, 4, &cmd1
[2], &cmd1
[3]);
1068 if(cmd1
[2] != Demod
.output
[4] || cmd1
[3] != Demod
.output
[5]) {
1069 Dbprintf("CRC Error reading block! Expected: %04x got: %04x",
1070 (cmd1
[2]<<8)+cmd1
[3], (Demod
.output
[4]<<8)+Demod
.output
[5]);
1071 // Do not return;, let's go on... (we should retry, maybe ?)
1073 // Now print out the memory location:
1074 Dbprintf("Address=%02x, Contents=%08x, CRC=%04x", i
,
1075 (Demod
.output
[3]<<24) + (Demod
.output
[2]<<16) + (Demod
.output
[1]<<8) + Demod
.output
[0],
1076 (Demod
.output
[4]<<8)+Demod
.output
[5]);
1084 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF
);
1088 //=============================================================================
1089 // Finally, the `sniffer' combines elements from both the reader and
1090 // simulated tag, to show both sides of the conversation.
1091 //=============================================================================
1093 //-----------------------------------------------------------------------------
1094 // Record the sequence of commands sent by the reader to the tag, with
1095 // triggering so that we start recording at the point that the tag is moved
1097 //-----------------------------------------------------------------------------
1099 * Memory usage for this function, (within BigBuf)
1100 * Last Received command (reader->tag) - MAX_FRAME_SIZE
1101 * Last Received command (tag->reader) - MAX_FRAME_SIZE
1102 * DMA Buffer - ISO14443B_DMA_BUFFER_SIZE
1103 * Demodulated samples received - all the rest
1105 void RAMFUNC
SnoopIso14443b(void)
1107 FpgaDownloadAndGo(FPGA_BITSTREAM_HF
);
1113 // The DMA buffer, used to stream samples from the FPGA
1114 uint16_t *dmaBuf
= (uint16_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE
* sizeof(uint16_t));
1118 int maxBehindBy
= 0;
1120 // Count of samples received so far, so that we can include timing
1121 // information in the trace buffer.
1124 DemodInit(BigBuf_malloc(MAX_FRAME_SIZE
));
1125 UartInit(BigBuf_malloc(MAX_FRAME_SIZE
));
1127 // Print some debug information about the buffer sizes
1128 Dbprintf("Snooping buffers initialized:");
1129 Dbprintf(" Trace: %i bytes", BigBuf_max_traceLen());
1130 Dbprintf(" Reader -> tag: %i bytes", MAX_FRAME_SIZE
);
1131 Dbprintf(" tag -> Reader: %i bytes", MAX_FRAME_SIZE
);
1132 Dbprintf(" DMA: %i bytes", ISO14443B_DMA_BUFFER_SIZE
);
1134 // Signal field is off, no reader signal, no tag signal
1137 // And put the FPGA in the appropriate mode
1138 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR
| FPGA_HF_READER_RX_XCORR_848_KHZ
| FPGA_HF_READER_RX_XCORR_SNOOP
);
1139 SetAdcMuxFor(GPIO_MUXSEL_HIPKD
);
1141 // Setup for the DMA.
1142 FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER_RX_XCORR
);
1144 lastRxCounter
= ISO14443B_DMA_BUFFER_SIZE
;
1145 FpgaSetupSscDma((uint8_t*) dmaBuf
, ISO14443B_DMA_BUFFER_SIZE
);
1147 bool TagIsActive
= false;
1148 bool ReaderIsActive
= false;
1149 // We won't start recording the frames that we acquire until we trigger.
1150 // A good trigger condition to get started is probably when we see a
1152 bool triggered
= false;
1154 // And now we loop, receiving samples.
1156 int behindBy
= (lastRxCounter
- AT91C_BASE_PDC_SSC
->PDC_RCR
) & (ISO14443B_DMA_BUFFER_SIZE
-1);
1157 if(behindBy
> maxBehindBy
) {
1158 maxBehindBy
= behindBy
;
1161 if(behindBy
< 1) continue;
1167 if(upTo
>= dmaBuf
+ ISO14443B_DMA_BUFFER_SIZE
) { // we have read all of the DMA buffer content.
1168 upTo
= dmaBuf
; // start reading the circular buffer from the beginning again
1169 lastRxCounter
+= ISO14443B_DMA_BUFFER_SIZE
;
1170 if(behindBy
> (9*ISO14443B_DMA_BUFFER_SIZE
/10)) {
1171 Dbprintf("About to blow circular buffer - aborted! behindBy=%d", behindBy
);
1175 if (AT91C_BASE_SSC
->SSC_SR
& (AT91C_SSC_ENDRX
)) { // DMA Counter Register had reached 0, already rotated.
1176 AT91C_BASE_PDC_SSC
->PDC_RNPR
= (uint32_t) dmaBuf
; // refresh the DMA Next Buffer and
1177 AT91C_BASE_PDC_SSC
->PDC_RNCR
= ISO14443B_DMA_BUFFER_SIZE
; // DMA Next Counter registers
1179 if(BUTTON_PRESS()) {
1180 DbpString("cancelled");
1187 if (!TagIsActive
) { // no need to try decoding reader data if the tag is sending
1188 if(Handle14443bUartBit(ci
& 0x01)) {
1190 LogTrace(Uart
.output
, Uart
.byteCnt
, samples
, samples
, NULL
, true);
1191 /* And ready to receive another command. */
1193 /* And also reset the demod code, which might have been */
1194 /* false-triggered by the commands from the reader. */
1197 if(Handle14443bUartBit(cq
& 0x01)) {
1199 LogTrace(Uart
.output
, Uart
.byteCnt
, samples
, samples
, NULL
, true);
1200 /* And ready to receive another command. */
1202 /* And also reset the demod code, which might have been */
1203 /* false-triggered by the commands from the reader. */
1206 ReaderIsActive
= (Uart
.state
> STATE_GOT_FALLING_EDGE_OF_SOF
);
1209 if(!ReaderIsActive
&& triggered
) { // no need to try decoding tag data if the reader is sending or not yet triggered
1210 if(Handle14443bSamplesDemod(ci
/2, cq
/2)) {
1211 //Use samples as a time measurement
1212 LogTrace(Demod
.output
, Demod
.len
, samples
, samples
, NULL
, false);
1213 // And ready to receive another response.
1216 TagIsActive
= (Demod
.state
> DEMOD_GOT_FALLING_EDGE_OF_SOF
);
1221 FpgaDisableSscDma();
1223 DbpString("Snoop statistics:");
1224 Dbprintf(" Max behind by: %i", maxBehindBy
);
1225 Dbprintf(" Uart State: %x", Uart
.state
);
1226 Dbprintf(" Uart ByteCnt: %i", Uart
.byteCnt
);
1227 Dbprintf(" Uart ByteCntMax: %i", Uart
.byteCntMax
);
1228 Dbprintf(" Trace length: %i", BigBuf_get_traceLen());
1233 * Send raw command to tag ISO14443B
1235 * datalen len of buffer data
1236 * recv bool when true wait for data from tag and send to client
1237 * powerfield bool leave the field on when true
1238 * data buffer with byte to send
1244 void SendRawCommand14443B(uint32_t datalen
, uint32_t recv
, uint8_t powerfield
, uint8_t data
[])
1246 FpgaDownloadAndGo(FPGA_BITSTREAM_HF
);
1247 SetAdcMuxFor(GPIO_MUXSEL_HIPKD
);
1249 // switch field on and give tag some time to power up
1251 FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER_TX
);
1257 CodeAndTransmit14443bAsReader(data
, datalen
);
1260 GetSamplesFor14443bDemod(RECEIVE_SAMPLES_TIMEOUT
, true);
1261 uint16_t iLen
= MIN(Demod
.len
, USB_CMD_DATA_SIZE
);
1262 cmd_send(CMD_ACK
, iLen
, 0, 0, Demod
.output
, iLen
);
1267 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF
);