]> git.zerfleddert.de Git - proxmark3-svn/blob - armsrc/iso14443.c
3c8e1fddad95ee42e52ec58ef5aa9dbb53745040
[proxmark3-svn] / armsrc / iso14443.c
1 //-----------------------------------------------------------------------------
2 // Jonathan Westhues, split Nov 2006
3 //
4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
5 // at your option, any later version. See the LICENSE.txt file for the text of
6 // the license.
7 //-----------------------------------------------------------------------------
8 // Routines to support ISO 14443. This includes both the reader software and
9 // the `fake tag' modes. At the moment only the Type B modulation is
10 // supported.
11 //-----------------------------------------------------------------------------
12
13 #include "proxmark3.h"
14 #include "apps.h"
15 #include "util.h"
16 #include "string.h"
17
18 #include "iso14443crc.h"
19
20 //static void GetSamplesFor14443(int weTx, int n);
21
22 #define DEMOD_TRACE_SIZE 4096
23 #define READER_TAG_BUFFER_SIZE 2048
24 #define TAG_READER_BUFFER_SIZE 2048
25 #define DEMOD_DMA_BUFFER_SIZE 1024
26
27 //=============================================================================
28 // An ISO 14443 Type B tag. We listen for commands from the reader, using
29 // a UART kind of thing that's implemented in software. When we get a
30 // frame (i.e., a group of bytes between SOF and EOF), we check the CRC.
31 // If it's good, then we can do something appropriate with it, and send
32 // a response.
33 //=============================================================================
34
35 //-----------------------------------------------------------------------------
36 // Code up a string of octets at layer 2 (including CRC, we don't generate
37 // that here) so that they can be transmitted to the reader. Doesn't transmit
38 // them yet, just leaves them ready to send in ToSend[].
39 //-----------------------------------------------------------------------------
40 static void CodeIso14443bAsTag(const uint8_t *cmd, int len)
41 {
42 int i;
43
44 ToSendReset();
45
46 // Transmit a burst of ones, as the initial thing that lets the
47 // reader get phase sync. This (TR1) must be > 80/fs, per spec,
48 // but tag that I've tried (a Paypass) exceeds that by a fair bit,
49 // so I will too.
50 for(i = 0; i < 20; i++) {
51 ToSendStuffBit(1);
52 ToSendStuffBit(1);
53 ToSendStuffBit(1);
54 ToSendStuffBit(1);
55 }
56
57 // Send SOF.
58 for(i = 0; i < 10; i++) {
59 ToSendStuffBit(0);
60 ToSendStuffBit(0);
61 ToSendStuffBit(0);
62 ToSendStuffBit(0);
63 }
64 for(i = 0; i < 2; i++) {
65 ToSendStuffBit(1);
66 ToSendStuffBit(1);
67 ToSendStuffBit(1);
68 ToSendStuffBit(1);
69 }
70
71 for(i = 0; i < len; i++) {
72 int j;
73 uint8_t b = cmd[i];
74
75 // Start bit
76 ToSendStuffBit(0);
77 ToSendStuffBit(0);
78 ToSendStuffBit(0);
79 ToSendStuffBit(0);
80
81 // Data bits
82 for(j = 0; j < 8; j++) {
83 if(b & 1) {
84 ToSendStuffBit(1);
85 ToSendStuffBit(1);
86 ToSendStuffBit(1);
87 ToSendStuffBit(1);
88 } else {
89 ToSendStuffBit(0);
90 ToSendStuffBit(0);
91 ToSendStuffBit(0);
92 ToSendStuffBit(0);
93 }
94 b >>= 1;
95 }
96
97 // Stop bit
98 ToSendStuffBit(1);
99 ToSendStuffBit(1);
100 ToSendStuffBit(1);
101 ToSendStuffBit(1);
102 }
103
104 // Send SOF.
105 for(i = 0; i < 10; i++) {
106 ToSendStuffBit(0);
107 ToSendStuffBit(0);
108 ToSendStuffBit(0);
109 ToSendStuffBit(0);
110 }
111 for(i = 0; i < 10; i++) {
112 ToSendStuffBit(1);
113 ToSendStuffBit(1);
114 ToSendStuffBit(1);
115 ToSendStuffBit(1);
116 }
117
118 // Convert from last byte pos to length
119 ToSendMax++;
120
121 // Add a few more for slop
122 ToSendMax += 2;
123 }
124
125 //-----------------------------------------------------------------------------
126 // The software UART that receives commands from the reader, and its state
127 // variables.
128 //-----------------------------------------------------------------------------
129 static struct {
130 enum {
131 STATE_UNSYNCD,
132 STATE_GOT_FALLING_EDGE_OF_SOF,
133 STATE_AWAITING_START_BIT,
134 STATE_RECEIVING_DATA,
135 STATE_ERROR_WAIT
136 } state;
137 uint16_t shiftReg;
138 int bitCnt;
139 int byteCnt;
140 int byteCntMax;
141 int posCnt;
142 uint8_t *output;
143 } Uart;
144
145 /* Receive & handle a bit coming from the reader.
146 *
147 * LED handling:
148 * LED A -> ON once we have received the SOF and are expecting the rest.
149 * LED A -> OFF once we have received EOF or are in error state or unsynced
150 *
151 * Returns: true if we received a EOF
152 * false if we are still waiting for some more
153 */
154 static int Handle14443UartBit(int bit)
155 {
156 switch(Uart.state) {
157 case STATE_UNSYNCD:
158 LED_A_OFF();
159 if(!bit) {
160 // we went low, so this could be the beginning
161 // of an SOF
162 Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF;
163 Uart.posCnt = 0;
164 Uart.bitCnt = 0;
165 }
166 break;
167
168 case STATE_GOT_FALLING_EDGE_OF_SOF:
169 Uart.posCnt++;
170 if(Uart.posCnt == 2) {
171 if(bit) {
172 if(Uart.bitCnt >= 10) {
173 // we've seen enough consecutive
174 // zeros that it's a valid SOF
175 Uart.posCnt = 0;
176 Uart.byteCnt = 0;
177 Uart.state = STATE_AWAITING_START_BIT;
178 LED_A_ON(); // Indicate we got a valid SOF
179 } else {
180 // didn't stay down long enough
181 // before going high, error
182 Uart.state = STATE_ERROR_WAIT;
183 }
184 } else {
185 // do nothing, keep waiting
186 }
187 Uart.bitCnt++;
188 }
189 if(Uart.posCnt >= 4) Uart.posCnt = 0;
190 if(Uart.bitCnt > 14) {
191 // Give up if we see too many zeros without
192 // a one, too.
193 Uart.state = STATE_ERROR_WAIT;
194 }
195 break;
196
197 case STATE_AWAITING_START_BIT:
198 Uart.posCnt++;
199 if(bit) {
200 if(Uart.posCnt > 25) {
201 // stayed high for too long between
202 // characters, error
203 Uart.state = STATE_ERROR_WAIT;
204 }
205 } else {
206 // falling edge, this starts the data byte
207 Uart.posCnt = 0;
208 Uart.bitCnt = 0;
209 Uart.shiftReg = 0;
210 Uart.state = STATE_RECEIVING_DATA;
211 LED_A_ON(); // Indicate we're receiving
212 }
213 break;
214
215 case STATE_RECEIVING_DATA:
216 Uart.posCnt++;
217 if(Uart.posCnt == 2) {
218 // time to sample a bit
219 Uart.shiftReg >>= 1;
220 if(bit) {
221 Uart.shiftReg |= 0x200;
222 }
223 Uart.bitCnt++;
224 }
225 if(Uart.posCnt >= 4) {
226 Uart.posCnt = 0;
227 }
228 if(Uart.bitCnt == 10) {
229 if((Uart.shiftReg & 0x200) && !(Uart.shiftReg & 0x001))
230 {
231 // this is a data byte, with correct
232 // start and stop bits
233 Uart.output[Uart.byteCnt] = (Uart.shiftReg >> 1) & 0xff;
234 Uart.byteCnt++;
235
236 if(Uart.byteCnt >= Uart.byteCntMax) {
237 // Buffer overflowed, give up
238 Uart.posCnt = 0;
239 Uart.state = STATE_ERROR_WAIT;
240 } else {
241 // so get the next byte now
242 Uart.posCnt = 0;
243 Uart.state = STATE_AWAITING_START_BIT;
244 }
245 } else if(Uart.shiftReg == 0x000) {
246 // this is an EOF byte
247 LED_A_OFF(); // Finished receiving
248 return TRUE;
249 } else {
250 // this is an error
251 Uart.posCnt = 0;
252 Uart.state = STATE_ERROR_WAIT;
253 }
254 }
255 break;
256
257 case STATE_ERROR_WAIT:
258 // We're all screwed up, so wait a little while
259 // for whatever went wrong to finish, and then
260 // start over.
261 Uart.posCnt++;
262 if(Uart.posCnt > 10) {
263 Uart.state = STATE_UNSYNCD;
264 }
265 break;
266
267 default:
268 Uart.state = STATE_UNSYNCD;
269 break;
270 }
271
272 // This row make the error blew circular buffer in hf 14b snoop
273 //if (Uart.state == STATE_ERROR_WAIT) LED_A_OFF(); // Error
274
275 return FALSE;
276 }
277
278 //-----------------------------------------------------------------------------
279 // Receive a command (from the reader to us, where we are the simulated tag),
280 // and store it in the given buffer, up to the given maximum length. Keeps
281 // spinning, waiting for a well-framed command, until either we get one
282 // (returns TRUE) or someone presses the pushbutton on the board (FALSE).
283 //
284 // Assume that we're called with the SSC (to the FPGA) and ADC path set
285 // correctly.
286 //-----------------------------------------------------------------------------
287 static int GetIso14443CommandFromReader(uint8_t *received, int *len, int maxLen)
288 {
289 uint8_t mask;
290 int i, bit;
291
292 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
293 // only, since we are receiving, not transmitting).
294 // Signal field is off with the appropriate LED
295 LED_D_OFF();
296 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION);
297
298
299 // Now run a `software UART' on the stream of incoming samples.
300 Uart.output = received;
301 Uart.byteCntMax = maxLen;
302 Uart.state = STATE_UNSYNCD;
303
304 for(;;) {
305 WDT_HIT();
306
307 if(BUTTON_PRESS()) return FALSE;
308
309 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
310 AT91C_BASE_SSC->SSC_THR = 0x00;
311 }
312 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
313 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
314
315 mask = 0x80;
316 for(i = 0; i < 8; i++, mask >>= 1) {
317 bit = (b & mask);
318 if(Handle14443UartBit(bit)) {
319 *len = Uart.byteCnt;
320 return TRUE;
321 }
322 }
323 }
324 }
325 }
326
327 //-----------------------------------------------------------------------------
328 // Main loop of simulated tag: receive commands from reader, decide what
329 // response to send, and send it.
330 //-----------------------------------------------------------------------------
331 void SimulateIso14443Tag(void)
332 {
333 static const uint8_t cmd1[] = { 0x05, 0x00, 0x08, 0x39, 0x73 };
334 static const uint8_t response1[] = {
335 0x50, 0x82, 0x0d, 0xe1, 0x74, 0x20, 0x38, 0x19, 0x22,
336 0x00, 0x21, 0x85, 0x5e, 0xd7
337 };
338
339 uint8_t *resp;
340 int respLen;
341
342 uint8_t *resp1 = (((uint8_t *)BigBuf) + 800);
343 int resp1Len;
344
345 uint8_t *receivedCmd = (uint8_t *)BigBuf;
346 int len;
347
348 int i;
349
350 int cmdsRecvd = 0;
351
352 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
353 memset(receivedCmd, 0x44, 400);
354
355 CodeIso14443bAsTag(response1, sizeof(response1));
356 memcpy(resp1, ToSend, ToSendMax); resp1Len = ToSendMax;
357
358 // We need to listen to the high-frequency, peak-detected path.
359 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
360 FpgaSetupSsc();
361
362 cmdsRecvd = 0;
363
364 for(;;) {
365 uint8_t b1, b2;
366
367 if(!GetIso14443CommandFromReader(receivedCmd, &len, 100)) {
368 Dbprintf("button pressed, received %d commands", cmdsRecvd);
369 break;
370 }
371
372 // Good, look at the command now.
373
374 if(len == sizeof(cmd1) && memcmp(receivedCmd, cmd1, len)==0) {
375 resp = resp1; respLen = resp1Len;
376 } else {
377 Dbprintf("new cmd from reader: len=%d, cmdsRecvd=%d", len, cmdsRecvd);
378 // And print whether the CRC fails, just for good measure
379 ComputeCrc14443(CRC_14443_B, receivedCmd, len-2, &b1, &b2);
380 if(b1 != receivedCmd[len-2] || b2 != receivedCmd[len-1]) {
381 // Not so good, try again.
382 DbpString("+++CRC fail");
383 } else {
384 DbpString("CRC passes");
385 }
386 break;
387 }
388
389 memset(receivedCmd, 0x44, 32);
390
391 cmdsRecvd++;
392
393 if(cmdsRecvd > 0x30) {
394 DbpString("many commands later...");
395 break;
396 }
397
398 if(respLen <= 0) continue;
399
400 // Modulate BPSK
401 // Signal field is off with the appropriate LED
402 LED_D_OFF();
403 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_BPSK);
404 AT91C_BASE_SSC->SSC_THR = 0xff;
405 FpgaSetupSsc();
406
407 // Transmit the response.
408 i = 0;
409 for(;;) {
410 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
411 uint8_t b = resp[i];
412
413 AT91C_BASE_SSC->SSC_THR = b;
414
415 i++;
416 if(i > respLen) {
417 break;
418 }
419 }
420 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
421 volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
422 (void)b;
423 }
424 }
425 }
426 }
427
428 //=============================================================================
429 // An ISO 14443 Type B reader. We take layer two commands, code them
430 // appropriately, and then send them to the tag. We then listen for the
431 // tag's response, which we leave in the buffer to be demodulated on the
432 // PC side.
433 //=============================================================================
434
435 static struct {
436 enum {
437 DEMOD_UNSYNCD,
438 DEMOD_PHASE_REF_TRAINING,
439 DEMOD_AWAITING_FALLING_EDGE_OF_SOF,
440 DEMOD_GOT_FALLING_EDGE_OF_SOF,
441 DEMOD_AWAITING_START_BIT,
442 DEMOD_RECEIVING_DATA,
443 DEMOD_ERROR_WAIT
444 } state;
445 int bitCount;
446 int posCount;
447 int thisBit;
448 int metric;
449 int metricN;
450 uint16_t shiftReg;
451 uint8_t *output;
452 int len;
453 int sumI;
454 int sumQ;
455 } Demod;
456
457 /*
458 * Handles reception of a bit from the tag
459 *
460 * LED handling:
461 * LED C -> ON once we have received the SOF and are expecting the rest.
462 * LED C -> OFF once we have received EOF or are unsynced
463 *
464 * Returns: true if we received a EOF
465 * false if we are still waiting for some more
466 *
467 */
468 static RAMFUNC int Handle14443SamplesDemod(int ci, int cq)
469 {
470 int v;
471
472 // The soft decision on the bit uses an estimate of just the
473 // quadrant of the reference angle, not the exact angle.
474 #define MAKE_SOFT_DECISION() { \
475 if(Demod.sumI > 0) { \
476 v = ci; \
477 } else { \
478 v = -ci; \
479 } \
480 if(Demod.sumQ > 0) { \
481 v += cq; \
482 } else { \
483 v -= cq; \
484 } \
485 }
486
487 switch(Demod.state) {
488 case DEMOD_UNSYNCD:
489 v = ci;
490 if(v < 0) v = -v;
491 if(cq > 0) {
492 v += cq;
493 } else {
494 v -= cq;
495 }
496 if(v > 40) {
497 Demod.posCount = 0;
498 Demod.state = DEMOD_PHASE_REF_TRAINING;
499 Demod.sumI = 0;
500 Demod.sumQ = 0;
501 }
502 break;
503
504 case DEMOD_PHASE_REF_TRAINING:
505 if(Demod.posCount < 8) {
506 Demod.sumI += ci;
507 Demod.sumQ += cq;
508 } else if(Demod.posCount > 100) {
509 // error, waited too long
510 Demod.state = DEMOD_UNSYNCD;
511 } else {
512 MAKE_SOFT_DECISION();
513 if(v < 0) {
514 Demod.state = DEMOD_AWAITING_FALLING_EDGE_OF_SOF;
515 Demod.posCount = 0;
516 }
517 }
518 Demod.posCount++;
519 break;
520
521 case DEMOD_AWAITING_FALLING_EDGE_OF_SOF:
522 MAKE_SOFT_DECISION();
523 if(v < 0) {
524 Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF;
525 Demod.posCount = 0;
526 } else {
527 if(Demod.posCount > 100) {
528 Demod.state = DEMOD_UNSYNCD;
529 }
530 }
531 Demod.posCount++;
532 break;
533
534 case DEMOD_GOT_FALLING_EDGE_OF_SOF:
535 MAKE_SOFT_DECISION();
536 if(v > 0) {
537 if(Demod.posCount < 12) {
538 Demod.state = DEMOD_UNSYNCD;
539 } else {
540 LED_C_ON(); // Got SOF
541 Demod.state = DEMOD_AWAITING_START_BIT;
542 Demod.posCount = 0;
543 Demod.len = 0;
544 Demod.metricN = 0;
545 Demod.metric = 0;
546 }
547 } else {
548 if(Demod.posCount > 100) {
549 Demod.state = DEMOD_UNSYNCD;
550 }
551 }
552 Demod.posCount++;
553 break;
554
555 case DEMOD_AWAITING_START_BIT:
556 MAKE_SOFT_DECISION();
557 if(v > 0) {
558 if(Demod.posCount > 10) {
559 Demod.state = DEMOD_UNSYNCD;
560 }
561 } else {
562 Demod.bitCount = 0;
563 Demod.posCount = 1;
564 Demod.thisBit = v;
565 Demod.shiftReg = 0;
566 Demod.state = DEMOD_RECEIVING_DATA;
567 }
568 break;
569
570 case DEMOD_RECEIVING_DATA:
571 MAKE_SOFT_DECISION();
572 if(Demod.posCount == 0) {
573 Demod.thisBit = v;
574 Demod.posCount = 1;
575 } else {
576 Demod.thisBit += v;
577
578 if(Demod.thisBit > 0) {
579 Demod.metric += Demod.thisBit;
580 } else {
581 Demod.metric -= Demod.thisBit;
582 }
583 (Demod.metricN)++;
584
585 Demod.shiftReg >>= 1;
586 if(Demod.thisBit > 0) {
587 Demod.shiftReg |= 0x200;
588 }
589
590 Demod.bitCount++;
591 if(Demod.bitCount == 10) {
592 uint16_t s = Demod.shiftReg;
593 if((s & 0x200) && !(s & 0x001)) {
594 uint8_t b = (s >> 1);
595 Demod.output[Demod.len] = b;
596 Demod.len++;
597 Demod.state = DEMOD_AWAITING_START_BIT;
598 } else if(s == 0x000) {
599 // This is EOF
600 LED_C_OFF();
601 Demod.state = DEMOD_UNSYNCD;
602 return TRUE;
603 } else {
604 Demod.state = DEMOD_UNSYNCD;
605 }
606 }
607 Demod.posCount = 0;
608 }
609 break;
610
611 default:
612 Demod.state = DEMOD_UNSYNCD;
613 break;
614 }
615
616 if (Demod.state == DEMOD_UNSYNCD) LED_C_OFF(); // Not synchronized...
617 return FALSE;
618 }
619
620 /*
621 * Demodulate the samples we received from the tag, also log to tracebuffer
622 * weTx: set to 'TRUE' if we behave like a reader
623 * set to 'FALSE' if we behave like a snooper
624 * quiet: set to 'TRUE' to disable debug output
625 */
626 static void GetSamplesFor14443Demod(int weTx, int n, int quiet)
627 {
628 int max = 0;
629 int gotFrame = FALSE;
630
631 int lastRxCounter;
632
633 int ci, cq;
634
635 int samples = 0;
636
637 // Clear out the state of the "UART" that receives from the tag.
638 memset(Demod.output, 0x00, MAX_FRAME_SIZE);
639 Demod.output = ((uint8_t *)BigBuf) + RECV_RESP_OFFSET;
640 Demod.len = 0;
641 Demod.state = DEMOD_UNSYNCD;
642
643 // And the UART that receives from the reader
644 Uart.output = ((uint8_t *)BigBuf) + RECV_CMD_OFFSET;
645 Uart.byteCntMax = MAX_FRAME_SIZE;
646 Uart.state = STATE_UNSYNCD;
647
648 // The DMA buffer, used to stream samples from the FPGA
649 int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET;
650 int8_t *upTo= dmaBuf;
651 lastRxCounter = DEMOD_DMA_BUFFER_SIZE;
652 FpgaSetupSscDma((uint8_t *)dmaBuf, DEMOD_DMA_BUFFER_SIZE);
653
654 // Signal field is ON with the appropriate LED:
655 if (weTx) LED_D_ON(); else LED_D_OFF();
656 // And put the FPGA in the appropriate mode
657 FpgaWriteConfWord(
658 FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ |
659 (weTx ? 0 : FPGA_HF_READER_RX_XCORR_SNOOP));
660
661 for(;;) {
662 int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR;
663 if(behindBy > max) max = behindBy;
664
665 while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (DEMOD_DMA_BUFFER_SIZE-1))
666 > 2)
667 {
668 ci = upTo[0];
669 cq = upTo[1];
670 upTo += 2;
671 if(upTo - dmaBuf > DEMOD_DMA_BUFFER_SIZE) {
672 upTo -= DEMOD_DMA_BUFFER_SIZE;
673 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo;
674 AT91C_BASE_PDC_SSC->PDC_RNCR = DEMOD_DMA_BUFFER_SIZE;
675 }
676 lastRxCounter -= 2;
677 if(lastRxCounter <= 0) {
678 lastRxCounter += DEMOD_DMA_BUFFER_SIZE;
679 }
680
681 samples += 2;
682
683 Handle14443UartBit(1);
684 Handle14443UartBit(1);
685
686 if(Handle14443SamplesDemod(ci, cq)) {
687 gotFrame = 1;
688 }
689 }
690
691 if(samples > 2000) {
692 break;
693 }
694 }
695 AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
696 if (!quiet) Dbprintf("%x %x %x", max, gotFrame, Demod.len);
697 //Tracing
698 if (tracing && Demod.len > 0) {
699 uint8_t parity[MAX_PARITY_SIZE];
700 GetParity(Demod.output , Demod.len, parity);
701 LogTrace(Demod.output,Demod.len, 0, 0, parity, FALSE);
702 }
703 }
704
705 //-----------------------------------------------------------------------------
706 // Read the tag's response. We just receive a stream of slightly-processed
707 // samples from the FPGA, which we will later do some signal processing on,
708 // to get the bits.
709 //-----------------------------------------------------------------------------
710 /*static void GetSamplesFor14443(int weTx, int n)
711 {
712 uint8_t *dest = (uint8_t *)BigBuf;
713 int c;
714
715 FpgaWriteConfWord(
716 FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ |
717 (weTx ? 0 : FPGA_HF_READER_RX_XCORR_SNOOP));
718
719 c = 0;
720 for(;;) {
721 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
722 AT91C_BASE_SSC->SSC_THR = 0x43;
723 }
724 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
725 int8_t b;
726 b = (int8_t)AT91C_BASE_SSC->SSC_RHR;
727
728 dest[c++] = (uint8_t)b;
729
730 if(c >= n) {
731 break;
732 }
733 }
734 }
735 }*/
736
737 //-----------------------------------------------------------------------------
738 // Transmit the command (to the tag) that was placed in ToSend[].
739 //-----------------------------------------------------------------------------
740 static void TransmitFor14443(void)
741 {
742 int c;
743
744 FpgaSetupSsc();
745
746 while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
747 AT91C_BASE_SSC->SSC_THR = 0xff;
748 }
749
750 // Signal field is ON with the appropriate Red LED
751 LED_D_ON();
752 // Signal we are transmitting with the Green LED
753 LED_B_ON();
754 FpgaWriteConfWord(
755 FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
756
757 for(c = 0; c < 10;) {
758 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
759 AT91C_BASE_SSC->SSC_THR = 0xff;
760 c++;
761 }
762 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
763 volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
764 (void)r;
765 }
766 WDT_HIT();
767 }
768
769 c = 0;
770 for(;;) {
771 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
772 AT91C_BASE_SSC->SSC_THR = ToSend[c];
773 c++;
774 if(c >= ToSendMax) {
775 break;
776 }
777 }
778 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
779 volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
780 (void)r;
781 }
782 WDT_HIT();
783 }
784 LED_B_OFF(); // Finished sending
785 }
786
787 //-----------------------------------------------------------------------------
788 // Code a layer 2 command (string of octets, including CRC) into ToSend[],
789 // so that it is ready to transmit to the tag using TransmitFor14443().
790 //-----------------------------------------------------------------------------
791 static void CodeIso14443bAsReader(const uint8_t *cmd, int len)
792 {
793 int i, j;
794 uint8_t b;
795
796 ToSendReset();
797
798 // Establish initial reference level
799 for(i = 0; i < 40; i++) {
800 ToSendStuffBit(1);
801 }
802 // Send SOF
803 for(i = 0; i < 10; i++) {
804 ToSendStuffBit(0);
805 }
806
807 for(i = 0; i < len; i++) {
808 // Stop bits/EGT
809 ToSendStuffBit(1);
810 ToSendStuffBit(1);
811 // Start bit
812 ToSendStuffBit(0);
813 // Data bits
814 b = cmd[i];
815 for(j = 0; j < 8; j++) {
816 if(b & 1) {
817 ToSendStuffBit(1);
818 } else {
819 ToSendStuffBit(0);
820 }
821 b >>= 1;
822 }
823 }
824 // Send EOF
825 ToSendStuffBit(1);
826 for(i = 0; i < 10; i++) {
827 ToSendStuffBit(0);
828 }
829 for(i = 0; i < 8; i++) {
830 ToSendStuffBit(1);
831 }
832
833 // And then a little more, to make sure that the last character makes
834 // it out before we switch to rx mode.
835 for(i = 0; i < 24; i++) {
836 ToSendStuffBit(1);
837 }
838
839 // Convert from last character reference to length
840 ToSendMax++;
841 }
842
843 //-----------------------------------------------------------------------------
844 // Read an ISO 14443 tag. We send it some set of commands, and record the
845 // responses.
846 // The command name is misleading, it actually decodes the reponse in HEX
847 // into the output buffer (read the result using hexsamples, not hisamples)
848 //
849 // obsolete function only for test
850 //-----------------------------------------------------------------------------
851 void AcquireRawAdcSamplesIso14443(uint32_t parameter)
852 {
853 uint8_t cmd1[] = { 0x05, 0x00, 0x08, 0x39, 0x73 };
854
855 SendRawCommand14443B(sizeof(cmd1),1,1,cmd1);
856 }
857
858 /**
859 Convenience function to encode, transmit and trace iso 14443b comms
860 **/
861 static void CodeAndTransmit14443bAsReader(const uint8_t *cmd, int len)
862 {
863 CodeIso14443bAsReader(cmd, len);
864 TransmitFor14443();
865 if (tracing) {
866 uint8_t parity[MAX_PARITY_SIZE];
867 GetParity(cmd, len, parity);
868 LogTrace(cmd,len, 0, 0, parity, TRUE);
869 }
870 }
871
872 //-----------------------------------------------------------------------------
873 // Read a SRI512 ISO 14443 tag.
874 //
875 // SRI512 tags are just simple memory tags, here we're looking at making a dump
876 // of the contents of the memory. No anticollision algorithm is done, we assume
877 // we have a single tag in the field.
878 //
879 // I tried to be systematic and check every answer of the tag, every CRC, etc...
880 //-----------------------------------------------------------------------------
881 void ReadSTMemoryIso14443(uint32_t dwLast)
882 {
883 clear_trace();
884 set_tracing(TRUE);
885
886 uint8_t i = 0x00;
887
888 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
889 // Make sure that we start from off, since the tags are stateful;
890 // confusing things will happen if we don't reset them between reads.
891 LED_D_OFF();
892 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
893 SpinDelay(200);
894
895 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
896 FpgaSetupSsc();
897
898 // Now give it time to spin up.
899 // Signal field is on with the appropriate LED
900 LED_D_ON();
901 FpgaWriteConfWord(
902 FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
903 SpinDelay(200);
904
905 // First command: wake up the tag using the INITIATE command
906 uint8_t cmd1[] = { 0x06, 0x00, 0x97, 0x5b};
907
908 CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1));
909 // LED_A_ON();
910 GetSamplesFor14443Demod(TRUE, 2000,TRUE);
911 // LED_A_OFF();
912
913 if (Demod.len == 0) {
914 DbpString("No response from tag");
915 return;
916 } else {
917 Dbprintf("Randomly generated UID from tag (+ 2 byte CRC): %x %x %x",
918 Demod.output[0], Demod.output[1],Demod.output[2]);
919 }
920 // There is a response, SELECT the uid
921 DbpString("Now SELECT tag:");
922 cmd1[0] = 0x0E; // 0x0E is SELECT
923 cmd1[1] = Demod.output[0];
924 ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
925 CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1));
926
927 // LED_A_ON();
928 GetSamplesFor14443Demod(TRUE, 2000,TRUE);
929 // LED_A_OFF();
930 if (Demod.len != 3) {
931 Dbprintf("Expected 3 bytes from tag, got %d", Demod.len);
932 return;
933 }
934 // Check the CRC of the answer:
935 ComputeCrc14443(CRC_14443_B, Demod.output, 1 , &cmd1[2], &cmd1[3]);
936 if(cmd1[2] != Demod.output[1] || cmd1[3] != Demod.output[2]) {
937 DbpString("CRC Error reading select response.");
938 return;
939 }
940 // Check response from the tag: should be the same UID as the command we just sent:
941 if (cmd1[1] != Demod.output[0]) {
942 Dbprintf("Bad response to SELECT from Tag, aborting: %x %x", cmd1[1], Demod.output[0]);
943 return;
944 }
945 // Tag is now selected,
946 // First get the tag's UID:
947 cmd1[0] = 0x0B;
948 ComputeCrc14443(CRC_14443_B, cmd1, 1 , &cmd1[1], &cmd1[2]);
949 CodeAndTransmit14443bAsReader(cmd1, 3); // Only first three bytes for this one
950
951 // LED_A_ON();
952 GetSamplesFor14443Demod(TRUE, 2000,TRUE);
953 // LED_A_OFF();
954 if (Demod.len != 10) {
955 Dbprintf("Expected 10 bytes from tag, got %d", Demod.len);
956 return;
957 }
958 // The check the CRC of the answer (use cmd1 as temporary variable):
959 ComputeCrc14443(CRC_14443_B, Demod.output, 8, &cmd1[2], &cmd1[3]);
960 if(cmd1[2] != Demod.output[8] || cmd1[3] != Demod.output[9]) {
961 Dbprintf("CRC Error reading block! - Below: expected, got %x %x",
962 (cmd1[2]<<8)+cmd1[3], (Demod.output[8]<<8)+Demod.output[9]);
963 // Do not return;, let's go on... (we should retry, maybe ?)
964 }
965 Dbprintf("Tag UID (64 bits): %08x %08x",
966 (Demod.output[7]<<24) + (Demod.output[6]<<16) + (Demod.output[5]<<8) + Demod.output[4],
967 (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0]);
968
969 // Now loop to read all 16 blocks, address from 0 to last block
970 Dbprintf("Tag memory dump, block 0 to %d",dwLast);
971 cmd1[0] = 0x08;
972 i = 0x00;
973 dwLast++;
974 for (;;) {
975 if (i == dwLast) {
976 DbpString("System area block (0xff):");
977 i = 0xff;
978 }
979 cmd1[1] = i;
980 ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
981 CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1));
982
983 // LED_A_ON();
984 GetSamplesFor14443Demod(TRUE, 2000,TRUE);
985 // LED_A_OFF();
986 if (Demod.len != 6) { // Check if we got an answer from the tag
987 DbpString("Expected 6 bytes from tag, got less...");
988 return;
989 }
990 // The check the CRC of the answer (use cmd1 as temporary variable):
991 ComputeCrc14443(CRC_14443_B, Demod.output, 4, &cmd1[2], &cmd1[3]);
992 if(cmd1[2] != Demod.output[4] || cmd1[3] != Demod.output[5]) {
993 Dbprintf("CRC Error reading block! - Below: expected, got %x %x",
994 (cmd1[2]<<8)+cmd1[3], (Demod.output[4]<<8)+Demod.output[5]);
995 // Do not return;, let's go on... (we should retry, maybe ?)
996 }
997 // Now print out the memory location:
998 Dbprintf("Address=%x, Contents=%x, CRC=%x", i,
999 (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0],
1000 (Demod.output[4]<<8)+Demod.output[5]);
1001 if (i == 0xff) {
1002 break;
1003 }
1004 i++;
1005 }
1006 }
1007
1008
1009 //=============================================================================
1010 // Finally, the `sniffer' combines elements from both the reader and
1011 // simulated tag, to show both sides of the conversation.
1012 //=============================================================================
1013
1014 //-----------------------------------------------------------------------------
1015 // Record the sequence of commands sent by the reader to the tag, with
1016 // triggering so that we start recording at the point that the tag is moved
1017 // near the reader.
1018 //-----------------------------------------------------------------------------
1019 /*
1020 * Memory usage for this function, (within BigBuf)
1021 * 0-4095 : Demodulated samples receive (4096 bytes) - DEMOD_TRACE_SIZE
1022 * 4096-6143 : Last Received command, 2048 bytes (reader->tag) - READER_TAG_BUFFER_SIZE
1023 * 6144-8191 : Last Received command, 2048 bytes(tag->reader) - TAG_READER_BUFFER_SIZE
1024 * 8192-9215 : DMA Buffer, 1024 bytes (samples) - DEMOD_DMA_BUFFER_SIZE
1025 */
1026 void RAMFUNC SnoopIso14443(void)
1027 {
1028 // We won't start recording the frames that we acquire until we trigger;
1029 // a good trigger condition to get started is probably when we see a
1030 // response from the tag.
1031 int triggered = TRUE;
1032
1033 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1034 // The command (reader -> tag) that we're working on receiving.
1035 uint8_t *receivedCmd = (uint8_t *)(BigBuf) + DEMOD_TRACE_SIZE;
1036 // The response (tag -> reader) that we're working on receiving.
1037 uint8_t *receivedResponse = (uint8_t *)(BigBuf) + DEMOD_TRACE_SIZE + READER_TAG_BUFFER_SIZE;
1038
1039 // As we receive stuff, we copy it from receivedCmd or receivedResponse
1040 // into trace, along with its length and other annotations.
1041 uint8_t *trace = (uint8_t *)BigBuf;
1042 int traceLen = 0;
1043
1044 // The DMA buffer, used to stream samples from the FPGA.
1045 int8_t *dmaBuf = (int8_t *)(BigBuf) + DEMOD_TRACE_SIZE + READER_TAG_BUFFER_SIZE + TAG_READER_BUFFER_SIZE;
1046 int lastRxCounter;
1047 int8_t *upTo;
1048 int ci, cq;
1049 int maxBehindBy = 0;
1050
1051 // Count of samples received so far, so that we can include timing
1052 // information in the trace buffer.
1053 int samples = 0;
1054
1055 // Initialize the trace buffer
1056 memset(trace, 0x44, DEMOD_TRACE_SIZE);
1057
1058 // Set up the demodulator for tag -> reader responses.
1059 Demod.output = receivedResponse;
1060 Demod.len = 0;
1061 Demod.state = DEMOD_UNSYNCD;
1062
1063 // And the reader -> tag commands
1064 memset(&Uart, 0, sizeof(Uart));
1065 Uart.output = receivedCmd;
1066 Uart.byteCntMax = 100;
1067 Uart.state = STATE_UNSYNCD;
1068
1069 // Print some debug information about the buffer sizes
1070 Dbprintf("Snooping buffers initialized:");
1071 Dbprintf(" Trace: %i bytes", DEMOD_TRACE_SIZE);
1072 Dbprintf(" Reader -> tag: %i bytes", READER_TAG_BUFFER_SIZE);
1073 Dbprintf(" tag -> Reader: %i bytes", TAG_READER_BUFFER_SIZE);
1074 Dbprintf(" DMA: %i bytes", DEMOD_DMA_BUFFER_SIZE);
1075
1076 // And put the FPGA in the appropriate mode
1077 // Signal field is off with the appropriate LED
1078 LED_D_OFF();
1079 FpgaWriteConfWord(
1080 FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ |
1081 FPGA_HF_READER_RX_XCORR_SNOOP);
1082 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1083
1084 // Setup for the DMA.
1085 FpgaSetupSsc();
1086 upTo = dmaBuf;
1087 lastRxCounter = DEMOD_DMA_BUFFER_SIZE;
1088 FpgaSetupSscDma((uint8_t *)dmaBuf, DEMOD_DMA_BUFFER_SIZE);
1089
1090 LED_A_ON();
1091
1092 // And now we loop, receiving samples.
1093 for(;;) {
1094 int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) &
1095 (DEMOD_DMA_BUFFER_SIZE-1);
1096 if(behindBy > maxBehindBy) {
1097 maxBehindBy = behindBy;
1098 if(behindBy > (DEMOD_DMA_BUFFER_SIZE-2)) { // TODO: understand whether we can increase/decrease as we want or not?
1099 Dbprintf("blew circular buffer! behindBy=0x%x", behindBy);
1100 goto done;
1101 }
1102 }
1103 if(behindBy < 2) continue;
1104
1105 ci = upTo[0];
1106 cq = upTo[1];
1107 upTo += 2;
1108 lastRxCounter -= 2;
1109 if(upTo - dmaBuf > DEMOD_DMA_BUFFER_SIZE) {
1110 upTo -= DEMOD_DMA_BUFFER_SIZE;
1111 lastRxCounter += DEMOD_DMA_BUFFER_SIZE;
1112 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo;
1113 AT91C_BASE_PDC_SSC->PDC_RNCR = DEMOD_DMA_BUFFER_SIZE;
1114 }
1115
1116 samples += 2;
1117
1118 #define HANDLE_BIT_IF_BODY \
1119 if(triggered && tracing) {\
1120 uint8_t parity[MAX_PARITY_SIZE];\
1121 GetParity(receivedCmd, Uart.byteCnt, parity);\
1122 LogTrace(receivedCmd,Uart.byteCnt,samples, samples,parity,TRUE);\
1123 if(!tracing) {\
1124 DbpString("Reached trace limit");\
1125 break;\
1126 }\
1127 }\
1128 /* And ready to receive another command. */ \
1129 memset(&Uart, 0, sizeof(Uart)); \
1130 Uart.output = receivedCmd; \
1131 Uart.byteCntMax = 100; \
1132 Uart.state = STATE_UNSYNCD; \
1133 /* And also reset the demod code, which might have been */ \
1134 /* false-triggered by the commands from the reader. */ \
1135 memset(&Demod, 0, sizeof(Demod)); \
1136 Demod.output = receivedResponse; \
1137 Demod.state = DEMOD_UNSYNCD; \
1138
1139 if(Handle14443UartBit(ci & 1)) {
1140 HANDLE_BIT_IF_BODY
1141 }
1142 if(Handle14443UartBit(cq & 1)) {
1143 HANDLE_BIT_IF_BODY
1144 }
1145
1146 if(Handle14443SamplesDemod(ci, cq)) {
1147
1148 //Use samples as a time measurement
1149 if(tracing)
1150 {
1151 uint8_t parity[MAX_PARITY_SIZE];
1152 GetParity(receivedResponse, Demod.len, parity);
1153 LogTrace(receivedResponse,Demod.len,samples, samples,parity,FALSE);
1154 if(!tracing) {
1155 DbpString("Reached trace limit");
1156 break;
1157 }
1158 }
1159 triggered = TRUE;
1160 LED_A_OFF();
1161 LED_B_ON();
1162
1163 // And ready to receive another response.
1164 memset(&Demod, 0, sizeof(Demod));
1165 Demod.output = receivedResponse;
1166 Demod.state = DEMOD_UNSYNCD;
1167 }
1168 WDT_HIT();
1169
1170 if(BUTTON_PRESS()) {
1171 DbpString("cancelled");
1172 goto done;
1173 }
1174 }
1175
1176 done:
1177 LED_A_OFF();
1178 LED_B_OFF();
1179 LED_C_OFF();
1180 AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
1181 DbpString("Snoop statistics:");
1182 Dbprintf(" Max behind by: %i", maxBehindBy);
1183 Dbprintf(" Uart State: %x", Uart.state);
1184 Dbprintf(" Uart ByteCnt: %i", Uart.byteCnt);
1185 Dbprintf(" Uart ByteCntMax: %i", Uart.byteCntMax);
1186 Dbprintf(" Trace length: %i", traceLen);
1187 }
1188
1189 /*
1190 * Send raw command to tag ISO14443B
1191 * @Input
1192 * datalen len of buffer data
1193 * recv bool when true wait for data from tag and send to client
1194 * powerfield bool leave the field on when true
1195 * data buffer with byte to send
1196 *
1197 * @Output
1198 * none
1199 *
1200 */
1201
1202 void SendRawCommand14443B(uint32_t datalen, uint32_t recv,uint8_t powerfield, uint8_t data[])
1203 {
1204 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1205 if(!powerfield)
1206 {
1207 // Make sure that we start from off, since the tags are stateful;
1208 // confusing things will happen if we don't reset them between reads.
1209 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1210 LED_D_OFF();
1211 SpinDelay(200);
1212 }
1213
1214 if(!GETBIT(GPIO_LED_D))
1215 {
1216 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1217 FpgaSetupSsc();
1218
1219 // Now give it time to spin up.
1220 // Signal field is on with the appropriate LED
1221 LED_D_ON();
1222 FpgaWriteConfWord(
1223 FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
1224 SpinDelay(200);
1225 }
1226
1227 CodeAndTransmit14443bAsReader(data, datalen);
1228
1229 if(recv)
1230 {
1231 uint16_t iLen = MIN(Demod.len,USB_CMD_DATA_SIZE);
1232 GetSamplesFor14443Demod(TRUE, 2000, TRUE);
1233 cmd_send(CMD_ACK,iLen,0,0,Demod.output,iLen);
1234 }
1235 if(!powerfield)
1236 {
1237 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1238 LED_D_OFF();
1239 }
1240 }
1241
Impressum, Datenschutz