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Merge pull request #32 from osysltd/patch-1
[proxmark3-svn] / armsrc / iso14443b.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 14443B. This includes both the reader software and
9 // the `fake tag' modes.
10 //-----------------------------------------------------------------------------
11 #include "iso14443b.h"
12
13 #ifndef FWT_TIMEOUT_14B
14 // defaults to 2000ms
15 # define FWT_TIMEOUT_14B 35312
16 #endif
17 #ifndef ISO14443B_DMA_BUFFER_SIZE
18 # define ISO14443B_DMA_BUFFER_SIZE 256
19 #endif
20 #ifndef RECEIVE_MASK
21 # define RECEIVE_MASK (ISO14443B_DMA_BUFFER_SIZE-1)
22 #endif
23
24 // Guard Time (per 14443-2)
25 #ifndef TR0
26 # define TR0 0
27 #endif
28
29 // Synchronization time (per 14443-2)
30 #ifndef TR1
31 # define TR1 0
32 #endif
33 // Frame Delay Time PICC to PCD (per 14443-3 Amendment 1)
34 #ifndef TR2
35 # define TR2 0
36 #endif
37
38 // 4sample
39 #define SEND4STUFFBIT(x) ToSendStuffBit(x);ToSendStuffBit(x);ToSendStuffBit(x);ToSendStuffBit(x);
40 //#define SEND4STUFFBIT(x) ToSendStuffBit(x);
41 // iceman, this threshold value, what makes 8 a good amplituted for this IQ values?
42 #ifndef SUBCARRIER_DETECT_THRESHOLD
43 # define SUBCARRIER_DETECT_THRESHOLD 8
44 #endif
45
46 static void iso14b_set_timeout(uint32_t timeout);
47 static void iso14b_set_maxframesize(uint16_t size);
48 static void switch_off(void);
49
50 // the block number for the ISO14443-4 PCB (used with APDUs)
51 static uint8_t pcb_blocknum = 0;
52 static uint32_t iso14b_timeout = FWT_TIMEOUT_14B;
53
54
55 //=============================================================================
56 // An ISO 14443 Type B tag. We listen for commands from the reader, using
57 // a UART kind of thing that's implemented in software. When we get a
58 // frame (i.e., a group of bytes between SOF and EOF), we check the CRC.
59 // If it's good, then we can do something appropriate with it, and send
60 // a response.
61 //=============================================================================
62
63
64 //-----------------------------------------------------------------------------
65 // The software UART that receives commands from the reader, and its state variables.
66 //-----------------------------------------------------------------------------
67 static struct {
68 enum {
69 STATE_UNSYNCD,
70 STATE_GOT_FALLING_EDGE_OF_SOF,
71 STATE_AWAITING_START_BIT,
72 STATE_RECEIVING_DATA
73 } state;
74 uint16_t shiftReg;
75 int bitCnt;
76 int byteCnt;
77 int byteCntMax;
78 int posCnt;
79 uint8_t *output;
80 } Uart;
81
82 static void UartReset() {
83 Uart.state = STATE_UNSYNCD;
84 Uart.shiftReg = 0;
85 Uart.bitCnt = 0;
86 Uart.byteCnt = 0;
87 Uart.byteCntMax = MAX_FRAME_SIZE;
88 Uart.posCnt = 0;
89 }
90
91 static void UartInit(uint8_t *data) {
92 Uart.output = data;
93 UartReset();
94 // memset(Uart.output, 0x00, MAX_FRAME_SIZE);
95 }
96
97 //-----------------------------------------------------------------------------
98 // The software Demod that receives commands from the tag, and its state variables.
99 //-----------------------------------------------------------------------------
100 static struct {
101 enum {
102 DEMOD_UNSYNCD,
103 DEMOD_PHASE_REF_TRAINING,
104 DEMOD_AWAITING_FALLING_EDGE_OF_SOF,
105 DEMOD_GOT_FALLING_EDGE_OF_SOF,
106 DEMOD_AWAITING_START_BIT,
107 DEMOD_RECEIVING_DATA
108 } state;
109 uint16_t bitCount;
110 int posCount;
111 int thisBit;
112 /* this had been used to add RSSI (Received Signal Strength Indication) to traces. Currently not implemented.
113 int metric;
114 int metricN;
115 */
116 uint16_t shiftReg;
117 uint8_t *output;
118 uint16_t len;
119 int sumI;
120 int sumQ;
121 uint32_t startTime, endTime;
122 } Demod;
123
124 // Clear out the state of the "UART" that receives from the tag.
125 static void DemodReset() {
126 Demod.state = DEMOD_UNSYNCD;
127 Demod.bitCount = 0;
128 Demod.posCount = 0;
129 Demod.thisBit = 0;
130 Demod.shiftReg = 0;
131 Demod.len = 0;
132 Demod.sumI = 0;
133 Demod.sumQ = 0;
134 Demod.startTime = 0;
135 Demod.endTime = 0;
136 }
137
138 static void DemodInit(uint8_t *data) {
139 Demod.output = data;
140 DemodReset();
141 // memset(Demod.output, 0x00, MAX_FRAME_SIZE);
142 }
143
144
145 /*
146 * 9.4395 us = 1 ETU and clock is about 1.5 us
147 * 13560000Hz
148 * 1000ms/s
149 * timeout in ETUs (time to transfer 1 bit, 9.4395 us)
150 *
151 * Formula to calculate FWT (in ETUs) by timeout (in ms):
152 * fwt = 13560000 * 1000 / (8*16) * timeout;
153 * Sample: 3sec == 3000ms
154 * 13560000 * 1000 / (8*16) * 3000 ==
155 * 13560000000 / 384000 = 35312 FWT
156 * @param timeout is in frame wait time, fwt, measured in ETUs
157 */
158 static void iso14b_set_timeout(uint32_t timeout) {
159 #define MAX_TIMEOUT 40542464 // 13560000Hz * 1000ms / (2^32-1) * (8*16)
160 if(timeout > MAX_TIMEOUT)
161 timeout = MAX_TIMEOUT;
162
163 iso14b_timeout = timeout;
164 if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443B Timeout set to %ld fwt", iso14b_timeout);
165 }
166 static void iso14b_set_maxframesize(uint16_t size) {
167 if (size > 256)
168 size = MAX_FRAME_SIZE;
169
170 Uart.byteCntMax = size;
171 if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443B Max frame size set to %d bytes", Uart.byteCntMax);
172 }
173 static void switch_off(void){
174 if (MF_DBGLEVEL > 3) Dbprintf("switch_off");
175 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
176 SpinDelay(100);
177 FpgaDisableSscDma();
178 set_tracing(FALSE);
179 LEDsoff();
180 }
181
182 void AppendCrc14443b(uint8_t* data, int len) {
183 ComputeCrc14443(CRC_14443_B, data, len, data+len, data+len+1);
184 }
185
186 //-----------------------------------------------------------------------------
187 // Code up a string of octets at layer 2 (including CRC, we don't generate
188 // that here) so that they can be transmitted to the reader. Doesn't transmit
189 // them yet, just leaves them ready to send in ToSend[].
190 //-----------------------------------------------------------------------------
191 static void CodeIso14443bAsTag(const uint8_t *cmd, int len) {
192 /* ISO 14443 B
193 *
194 * Reader to card | ASK - Amplitude Shift Keying Modulation (PCD to PICC for Type B) (NRZ-L encodig)
195 * Card to reader | BPSK - Binary Phase Shift Keying Modulation, (PICC to PCD for Type B)
196 *
197 * fc - carrier frequency 13.56mHz
198 * TR0 - Guard Time per 14443-2
199 * TR1 - Synchronization Time per 14443-2
200 * TR2 - PICC to PCD Frame Delay Time (per 14443-3 Amendment 1)
201 *
202 * Elementary Time Unit (ETU) is
203 * - 128 Carrier Cycles (9.4395 µS) = 8 Subcarrier Units
204 * - 1 ETU = 1 bit
205 * - 10 ETU = 1 startbit, 8 databits, 1 stopbit (10bits length)
206 * - startbit is a 0
207 * - stopbit is a 1
208 *
209 * Start of frame (SOF) is
210 * - [10-11] ETU of ZEROS, unmodulated time
211 * - [2-3] ETU of ONES,
212 *
213 * End of frame (EOF) is
214 * - [10-11] ETU of ZEROS, unmodulated time
215 *
216 * -TO VERIFY THIS BELOW-
217 * The mode FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_BPSK which we use to simulate tag
218 * works like this:
219 * - A 1-bit input to the FPGA becomes 8 pulses at 847.5kHz (9.44µS)
220 * - A 0-bit input to the FPGA becomes an unmodulated time of 9.44µS
221 *
222 *
223 *
224 * Card sends data ub 847.e kHz subcarrier
225 * 848k = 9.44µS = 128 fc
226 * 424k = 18.88µS = 256 fc
227 * 212k = 37.76µS = 512 fc
228 * 106k = 75.52µS = 1024 fc
229 *
230 * Reader data transmission:
231 * - no modulation ONES
232 * - SOF
233 * - Command, data and CRC_B
234 * - EOF
235 * - no modulation ONES
236 *
237 * Card data transmission
238 * - TR1
239 * - SOF
240 * - data (each bytes is: 1startbit, 8bits, 1stopbit)
241 * - CRC_B
242 * - EOF
243 *
244 * FPGA implementation :
245 * At this point only Type A is implemented. This means that we are using a
246 * bit rate of 106 kbit/s, or fc/128. Oversample by 4, which ought to make
247 * things practical for the ARM (fc/32, 423.8 kbits/s, ~50 kbytes/s)
248 *
249 */
250
251 int i,j;
252 uint8_t b;
253
254 ToSendReset();
255
256 // Transmit a burst of ones, as the initial thing that lets the
257 // reader get phase sync.
258 // This loop is TR1, per specification
259 // TR1 minimum must be > 80/fs
260 // TR1 maximum 200/fs
261 // 80/fs < TR1 < 200/fs
262 // 10 ETU < TR1 < 24 ETU
263
264 // Send SOF.
265 // 10-11 ETU * 4times samples ZEROS
266 for(i = 0; i < 10; i++) { SEND4STUFFBIT(0); }
267 //for(i = 0; i < 10; i++) { ToSendStuffBit(0); }
268
269 // 2-3 ETU * 4times samples ONES
270 for(i = 0; i < 3; i++) { SEND4STUFFBIT(1); }
271 //for(i = 0; i < 3; i++) { ToSendStuffBit(1); }
272
273 // data
274 for(i = 0; i < len; ++i) {
275
276 // Start bit
277 SEND4STUFFBIT(0);
278 //ToSendStuffBit(0);
279
280 // Data bits
281 b = cmd[i];
282 for(j = 0; j < 8; ++j) {
283 // if(b & 1) {
284 // SEND4STUFFBIT(1);
285 // //ToSendStuffBit(1);
286 // } else {
287 // SEND4STUFFBIT(0);
288 // //ToSendStuffBit(0);
289 // }
290 SEND4STUFFBIT( b & 1 );
291 b >>= 1;
292 }
293
294 // Stop bit
295 SEND4STUFFBIT(1);
296 //ToSendStuffBit(1);
297
298 // Extra Guard bit
299 // For PICC it ranges 0-18us (1etu = 9us)
300 SEND4STUFFBIT(1);
301 //ToSendStuffBit(1);
302 }
303
304 // Send EOF.
305 // 10-11 ETU * 4 sample rate = ZEROS
306 for(i = 0; i < 10; i++) { SEND4STUFFBIT(0); }
307 //for(i = 0; i < 10; i++) { ToSendStuffBit(0); }
308
309 // why this?
310 for(i = 0; i < 40; i++) { SEND4STUFFBIT(1); }
311 //for(i = 0; i < 40; i++) { ToSendStuffBit(1); }
312
313 // Convert from last byte pos to length
314 ++ToSendMax;
315 }
316
317
318 /* Receive & handle a bit coming from the reader.
319 *
320 * This function is called 4 times per bit (every 2 subcarrier cycles).
321 * Subcarrier frequency fs is 848kHz, 1/fs = 1,18us, i.e. function is called every 2,36us
322 *
323 * LED handling:
324 * LED A -> ON once we have received the SOF and are expecting the rest.
325 * LED A -> OFF once we have received EOF or are in error state or unsynced
326 *
327 * Returns: true if we received a EOF
328 * false if we are still waiting for some more
329 */
330 static RAMFUNC int Handle14443bReaderUartBit(uint8_t bit) {
331 switch (Uart.state) {
332 case STATE_UNSYNCD:
333 if (!bit) {
334 // we went low, so this could be the beginning of an SOF
335 Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF;
336 Uart.posCnt = 0;
337 Uart.bitCnt = 0;
338 }
339 break;
340
341 case STATE_GOT_FALLING_EDGE_OF_SOF:
342 Uart.posCnt++;
343 if (Uart.posCnt == 2) { // sample every 4 1/fs in the middle of a bit
344 if (bit) {
345 if (Uart.bitCnt > 9) {
346 // we've seen enough consecutive
347 // zeros that it's a valid SOF
348 Uart.posCnt = 0;
349 Uart.byteCnt = 0;
350 Uart.state = STATE_AWAITING_START_BIT;
351 LED_A_ON(); // Indicate we got a valid SOF
352 } else {
353 // didn't stay down long enough before going high, error
354 Uart.state = STATE_UNSYNCD;
355 }
356 } else {
357 // do nothing, keep waiting
358 }
359 Uart.bitCnt++;
360 }
361 if (Uart.posCnt >= 4) Uart.posCnt = 0;
362 if (Uart.bitCnt > 12) {
363 // Give up if we see too many zeros without a one, too.
364 LED_A_OFF();
365 Uart.state = STATE_UNSYNCD;
366 }
367 break;
368
369 case STATE_AWAITING_START_BIT:
370 Uart.posCnt++;
371 if (bit) {
372 if (Uart.posCnt > 50/2) { // max 57us between characters = 49 1/fs, max 3 etus after low phase of SOF = 24 1/fs
373 // stayed high for too long between characters, error
374 Uart.state = STATE_UNSYNCD;
375 }
376 } else {
377 // falling edge, this starts the data byte
378 Uart.posCnt = 0;
379 Uart.bitCnt = 0;
380 Uart.shiftReg = 0;
381 Uart.state = STATE_RECEIVING_DATA;
382 }
383 break;
384
385 case STATE_RECEIVING_DATA:
386 Uart.posCnt++;
387 if (Uart.posCnt == 2) {
388 // time to sample a bit
389 Uart.shiftReg >>= 1;
390 if (bit) {
391 Uart.shiftReg |= 0x200;
392 }
393 Uart.bitCnt++;
394 }
395 if (Uart.posCnt >= 4) {
396 Uart.posCnt = 0;
397 }
398 if (Uart.bitCnt == 10) {
399 if ((Uart.shiftReg & 0x200) && !(Uart.shiftReg & 0x001))
400 {
401 // this is a data byte, with correct
402 // start and stop bits
403 Uart.output[Uart.byteCnt] = (Uart.shiftReg >> 1) & 0xff;
404 Uart.byteCnt++;
405
406 if (Uart.byteCnt >= Uart.byteCntMax) {
407 // Buffer overflowed, give up
408 LED_A_OFF();
409 Uart.state = STATE_UNSYNCD;
410 } else {
411 // so get the next byte now
412 Uart.posCnt = 0;
413 Uart.state = STATE_AWAITING_START_BIT;
414 }
415 } else if (Uart.shiftReg == 0x000) {
416 // this is an EOF byte
417 LED_A_OFF(); // Finished receiving
418 Uart.state = STATE_UNSYNCD;
419 if (Uart.byteCnt != 0)
420 return TRUE;
421
422 } else {
423 // this is an error
424 LED_A_OFF();
425 Uart.state = STATE_UNSYNCD;
426 }
427 }
428 break;
429
430 default:
431 LED_A_OFF();
432 Uart.state = STATE_UNSYNCD;
433 break;
434 }
435 return FALSE;
436 }
437
438 //-----------------------------------------------------------------------------
439 // Receive a command (from the reader to us, where we are the simulated tag),
440 // and store it in the given buffer, up to the given maximum length. Keeps
441 // spinning, waiting for a well-framed command, until either we get one
442 // (returns TRUE) or someone presses the pushbutton on the board (FALSE).
443 //
444 // Assume that we're called with the SSC (to the FPGA) and ADC path set
445 // correctly.
446 //-----------------------------------------------------------------------------
447 static int GetIso14443bCommandFromReader(uint8_t *received, uint16_t *len) {
448 // Set FPGA mode to "simulated ISO 14443B tag", no modulation (listen
449 // only, since we are receiving, not transmitting).
450 // Signal field is off with the appropriate LED
451 LED_D_OFF();
452 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION);
453
454 StartCountSspClk();
455
456 volatile uint8_t b;
457
458 // clear receiving shift register and holding register
459 // What does this loop do? Is it TR1?
460 for(uint8_t c = 0; c < 10;) {
461 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
462 AT91C_BASE_SSC->SSC_THR = 0xFF;
463 ++c;
464 }
465 }
466
467 // Now run a `software UART' on the stream of incoming samples.
468 UartInit(received);
469
470 b = 0;
471 uint8_t mask;
472 while( !BUTTON_PRESS() ) {
473 WDT_HIT();
474
475 if ( AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY ) {
476 b = (uint8_t) AT91C_BASE_SSC->SSC_RHR;
477 for ( mask = 0x80; mask != 0; mask >>= 1) {
478 if ( Handle14443bReaderUartBit(b & mask)) {
479 *len = Uart.byteCnt;
480 return TRUE;
481 }
482 }
483 }
484 }
485 return FALSE;
486 }
487
488 void ClearFpgaShiftingRegisters(void){
489
490 volatile uint8_t b;
491
492 // clear receiving shift register and holding register
493 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
494
495 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
496
497 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
498
499 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
500
501
502 // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
503 for (uint8_t j = 0; j < 5; j++) { // allow timeout - better late than never
504 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
505 if (AT91C_BASE_SSC->SSC_RHR) break;
506 }
507
508 // Clear TXRDY:
509 //AT91C_BASE_SSC->SSC_THR = 0xFF;
510 }
511
512 void WaitForFpgaDelayQueueIsEmpty( uint16_t delay ){
513 // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
514 uint8_t fpga_queued_bits = delay >> 3; // twich /8 ?? >>3,
515 for (uint8_t i = 0; i <= fpga_queued_bits/8 + 1; ) {
516 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
517 AT91C_BASE_SSC->SSC_THR = 0xFF;
518 i++;
519 }
520 }
521 }
522
523 static void TransmitFor14443b_AsTag( uint8_t *response, uint16_t len) {
524
525 volatile uint32_t b;
526
527 // Signal field is off with the appropriate LED
528 LED_D_OFF();
529 //uint16_t fpgasendQueueDelay = 0;
530
531 // Modulate BPSK
532 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_BPSK);
533 SpinDelay(40);
534
535 ClearFpgaShiftingRegisters();
536
537 FpgaSetupSsc();
538
539 // Transmit the response.
540 for(uint16_t i = 0; i < len;) {
541 if(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
542 AT91C_BASE_SSC->SSC_THR = response[++i];
543 }
544 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
545 b = AT91C_BASE_SSC->SSC_RHR;
546 (void)b;
547 }
548 }
549
550 //WaitForFpgaDelayQueueIsEmpty(fpgasendQueueDelay);
551 AT91C_BASE_SSC->SSC_THR = 0xFF;
552 }
553 //-----------------------------------------------------------------------------
554 // Main loop of simulated tag: receive commands from reader, decide what
555 // response to send, and send it.
556 //-----------------------------------------------------------------------------
557 void SimulateIso14443bTag(uint32_t pupi) {
558
559 ///////////// setup device.
560 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
561
562 // allocate command receive buffer
563 BigBuf_free();
564 BigBuf_Clear_ext(false);
565 clear_trace(); //sim
566 set_tracing(TRUE);
567
568 // connect Demodulated Signal to ADC:
569 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
570
571 // Set up the synchronous serial port
572 FpgaSetupSsc();
573 /////////////
574
575 uint16_t len, cmdsReceived = 0;
576 int cardSTATE = SIM_NOFIELD;
577 int vHf = 0; // in mV
578 // uint32_t time_0 = 0;
579 // uint32_t t2r_time = 0;
580 // uint32_t r2t_time = 0;
581 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
582
583 // the only commands we understand is WUPB, AFI=0, Select All, N=1:
584 // static const uint8_t cmdWUPB[] = { ISO14443B_REQB, 0x00, 0x08, 0x39, 0x73 }; // WUPB
585 // ... and REQB, AFI=0, Normal Request, N=1:
586 // static const uint8_t cmdREQB[] = { ISO14443B_REQB, 0x00, 0x00, 0x71, 0xFF }; // REQB
587 // ... and ATTRIB
588 // static const uint8_t cmdATTRIB[] = { ISO14443B_ATTRIB, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; // ATTRIB
589
590 // ... if not PUPI/UID is supplied we always respond with ATQB, PUPI = 820de174, Application Data = 0x20381922,
591 // supports only 106kBit/s in both directions, max frame size = 32Bytes,
592 // supports ISO14443-4, FWI=8 (77ms), NAD supported, CID not supported:
593 uint8_t respATQB[] = { 0x50, 0x82, 0x0d, 0xe1, 0x74, 0x20, 0x38, 0x19,
594 0x22, 0x00, 0x21, 0x85, 0x5e, 0xd7 };
595
596 // response to HLTB and ATTRIB
597 static const uint8_t respOK[] = {0x00, 0x78, 0xF0};
598
599 // ...PUPI/UID supplied from user. Adjust ATQB response accordingly
600 if ( pupi > 0 ) {
601 uint8_t len = sizeof(respATQB);
602 num_to_bytes(pupi, 4, respATQB+1);
603 ComputeCrc14443(CRC_14443_B, respATQB, 12, &respATQB[len-2], &respATQB[len-1]);
604 }
605
606 // prepare "ATQB" tag answer (encoded):
607 CodeIso14443bAsTag(respATQB, sizeof(respATQB));
608 uint8_t *encodedATQB = BigBuf_malloc(ToSendMax);
609 uint16_t encodedATQBLen = ToSendMax;
610 memcpy(encodedATQB, ToSend, ToSendMax);
611
612
613 // prepare "OK" tag answer (encoded):
614 CodeIso14443bAsTag(respOK, sizeof(respOK));
615 uint8_t *encodedOK = BigBuf_malloc(ToSendMax);
616 uint16_t encodedOKLen = ToSendMax;
617 memcpy(encodedOK, ToSend, ToSendMax);
618
619 // Simulation loop
620 while (!BUTTON_PRESS() && !usb_poll_validate_length()) {
621 WDT_HIT();
622
623 // find reader field
624 if (cardSTATE == SIM_NOFIELD) {
625 vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
626 if ( vHf > MF_MINFIELDV ) {
627 cardSTATE = SIM_IDLE;
628 LED_A_ON();
629 }
630 }
631 if (cardSTATE == SIM_NOFIELD) continue;
632
633 // Get reader command
634 if (!GetIso14443bCommandFromReader(receivedCmd, &len)) {
635 Dbprintf("button pressed, received %d commands", cmdsReceived);
636 break;
637 }
638
639 // ISO14443-B protocol states:
640 // REQ or WUP request in ANY state
641 // WUP in HALTED state
642 if (len == 5 ) {
643 if ( (receivedCmd[0] == ISO14443B_REQB && (receivedCmd[2] & 0x8)== 0x8 && cardSTATE == SIM_HALTED) ||
644 receivedCmd[0] == ISO14443B_REQB ){
645 LogTrace(receivedCmd, len, 0, 0, NULL, TRUE);
646 cardSTATE = SIM_SELECTING;
647 }
648 }
649
650 /*
651 * How should this flow go?
652 * REQB or WUPB
653 * send response ( waiting for Attrib)
654 * ATTRIB
655 * send response ( waiting for commands 7816)
656 * HALT
657 send halt response ( waiting for wupb )
658 */
659
660 switch (cardSTATE) {
661 case SIM_NOFIELD:
662 case SIM_HALTED:
663 case SIM_IDLE: {
664 LogTrace(receivedCmd, len, 0, 0, NULL, TRUE);
665 break;
666 }
667 case SIM_SELECTING: {
668 TransmitFor14443b_AsTag( encodedATQB, encodedATQBLen );
669 LogTrace(respATQB, sizeof(respATQB), 0, 0, NULL, FALSE);
670 cardSTATE = SIM_WORK;
671 break;
672 }
673 case SIM_HALTING: {
674 TransmitFor14443b_AsTag( encodedOK, encodedOKLen );
675 LogTrace(respOK, sizeof(respOK), 0, 0, NULL, FALSE);
676 cardSTATE = SIM_HALTED;
677 break;
678 }
679 case SIM_ACKNOWLEDGE: {
680 TransmitFor14443b_AsTag( encodedOK, encodedOKLen );
681 LogTrace(respOK, sizeof(respOK), 0, 0, NULL, FALSE);
682 cardSTATE = SIM_IDLE;
683 break;
684 }
685 case SIM_WORK: {
686 if ( len == 7 && receivedCmd[0] == ISO14443B_HALT ) {
687 cardSTATE = SIM_HALTED;
688 } else if ( len == 11 && receivedCmd[0] == ISO14443B_ATTRIB ) {
689 cardSTATE = SIM_ACKNOWLEDGE;
690 } else {
691 // Todo:
692 // - SLOT MARKER
693 // - ISO7816
694 // - emulate with a memory dump
695 Dbprintf("new cmd from reader: len=%d, cmdsRecvd=%d", len, cmdsReceived);
696
697 // CRC Check
698 uint8_t b1, b2;
699 if (len >= 3){ // if crc exists
700 ComputeCrc14443(CRC_14443_B, receivedCmd, len-2, &b1, &b2);
701 if(b1 != receivedCmd[len-2] || b2 != receivedCmd[len-1])
702 DbpString("+++CRC fail");
703 else
704 DbpString("CRC passes");
705 }
706 cardSTATE = SIM_IDLE;
707 }
708 break;
709 }
710 default: break;
711 }
712
713 ++cmdsReceived;
714 // iceman, could add a switch to turn this on/off (if off, no logging?)
715 if(cmdsReceived > 1000) {
716 DbpString("14B Simulate, 1000 commands later...");
717 break;
718 }
719 }
720 if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen());
721 switch_off(); //simulate
722 }
723
724 //=============================================================================
725 // An ISO 14443 Type B reader. We take layer two commands, code them
726 // appropriately, and then send them to the tag. We then listen for the
727 // tag's response, which we leave in the buffer to be demodulated on the
728 // PC side.
729 //=============================================================================
730
731 /*
732 * Handles reception of a bit from the tag
733 *
734 * This function is called 2 times per bit (every 4 subcarrier cycles).
735 * Subcarrier frequency fs is 848kHz, 1/fs = 1,18us, i.e. function is called every 4,72us
736 *
737 * LED handling:
738 * LED C -> ON once we have received the SOF and are expecting the rest.
739 * LED C -> OFF once we have received EOF or are unsynced
740 *
741 * Returns: true if we received a EOF
742 * false if we are still waiting for some more
743 *
744 */
745 static RAMFUNC int Handle14443bTagSamplesDemod(int ci, int cq) {
746 int v = 0, myI = ABS(ci), myQ = ABS(cq);
747
748 // The soft decision on the bit uses an estimate of just the
749 // quadrant of the reference angle, not the exact angle.
750 #define MAKE_SOFT_DECISION() { \
751 if(Demod.sumI > 0) { \
752 v = ci; \
753 } else { \
754 v = -ci; \
755 } \
756 if(Demod.sumQ > 0) { \
757 v += cq; \
758 } else { \
759 v -= cq; \
760 } \
761 }
762
763 // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by abs(ci) + abs(cq)
764 // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq)))
765 #define CHECK_FOR_SUBCARRIER_old() { \
766 if(ci < 0) { \
767 if(cq < 0) { /* ci < 0, cq < 0 */ \
768 if (cq < ci) { \
769 v = -cq - (ci >> 1); \
770 } else { \
771 v = -ci - (cq >> 1); \
772 } \
773 } else { /* ci < 0, cq >= 0 */ \
774 if (cq < -ci) { \
775 v = -ci + (cq >> 1); \
776 } else { \
777 v = cq - (ci >> 1); \
778 } \
779 } \
780 } else { \
781 if(cq < 0) { /* ci >= 0, cq < 0 */ \
782 if (-cq < ci) { \
783 v = ci - (cq >> 1); \
784 } else { \
785 v = -cq + (ci >> 1); \
786 } \
787 } else { /* ci >= 0, cq >= 0 */ \
788 if (cq < ci) { \
789 v = ci + (cq >> 1); \
790 } else { \
791 v = cq + (ci >> 1); \
792 } \
793 } \
794 } \
795 }
796
797 //note: couldn't we just use MAX(ABS(ci),ABS(cq)) + (MIN(ABS(ci),ABS(cq))/2) from common.h - marshmellow
798 #define CHECK_FOR_SUBCARRIER() { \
799 v = MAX(myI, myQ) + (MIN(myI, myQ) >> 1); \
800 }
801
802 switch(Demod.state) {
803 case DEMOD_UNSYNCD:
804
805 CHECK_FOR_SUBCARRIER();
806
807 // subcarrier detected
808 if (v > SUBCARRIER_DETECT_THRESHOLD) {
809 Demod.state = DEMOD_PHASE_REF_TRAINING;
810 Demod.sumI = ci;
811 Demod.sumQ = cq;
812 Demod.posCount = 1;
813 }
814 break;
815
816 case DEMOD_PHASE_REF_TRAINING:
817 if (Demod.posCount < 8) {
818
819 CHECK_FOR_SUBCARRIER();
820
821 if (v > SUBCARRIER_DETECT_THRESHOLD) {
822 // set the reference phase (will code a logic '1') by averaging over 32 1/fs.
823 // note: synchronization time > 80 1/fs
824 Demod.sumI += ci;
825 Demod.sumQ += cq;
826 ++Demod.posCount;
827 } else {
828 // subcarrier lost
829 Demod.state = DEMOD_UNSYNCD;
830 }
831 } else {
832 Demod.state = DEMOD_AWAITING_FALLING_EDGE_OF_SOF;
833 }
834 break;
835
836 case DEMOD_AWAITING_FALLING_EDGE_OF_SOF:
837
838 MAKE_SOFT_DECISION();
839
840 if (v < 0) { // logic '0' detected
841 Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF;
842 Demod.posCount = 0; // start of SOF sequence
843 } else {
844 // maximum length of TR1 = 200 1/fs
845 if(Demod.posCount > 26*2) Demod.state = DEMOD_UNSYNCD;
846 }
847 ++Demod.posCount;
848 break;
849
850 case DEMOD_GOT_FALLING_EDGE_OF_SOF:
851 ++Demod.posCount;
852
853 MAKE_SOFT_DECISION();
854
855 if (v > 0) {
856 // low phase of SOF too short (< 9 etu). Note: spec is >= 10, but FPGA tends to "smear" edges
857 if (Demod.posCount < 8*2) {
858 Demod.state = DEMOD_UNSYNCD;
859 } else {
860 LED_C_ON(); // Got SOF
861 //Demod.startTime = GetCountSspClk();
862 Demod.state = DEMOD_AWAITING_START_BIT;
863 Demod.posCount = 0;
864 Demod.len = 0;
865 }
866 } else {
867 // low phase of SOF too long (> 12 etu)
868 if (Demod.posCount > 14*2) {
869 Demod.state = DEMOD_UNSYNCD;
870 LED_C_OFF();
871 }
872 }
873 break;
874
875 case DEMOD_AWAITING_START_BIT:
876 ++Demod.posCount;
877
878 MAKE_SOFT_DECISION();
879
880 if (v > 0) {
881 if(Demod.posCount > 2*2) { // max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs
882 Demod.state = DEMOD_UNSYNCD;
883 LED_C_OFF();
884 }
885 } else { // start bit detected
886 Demod.bitCount = 0;
887 Demod.posCount = 1; // this was the first half
888 Demod.thisBit = v;
889 Demod.shiftReg = 0;
890 Demod.state = DEMOD_RECEIVING_DATA;
891 }
892 break;
893
894 case DEMOD_RECEIVING_DATA:
895
896 MAKE_SOFT_DECISION();
897
898 if (Demod.posCount == 0) {
899 // first half of bit
900 Demod.thisBit = v;
901 Demod.posCount = 1;
902 } else {
903 // second half of bit
904 Demod.thisBit += v;
905 Demod.shiftReg >>= 1;
906
907 // OR in a logic '1'
908 if (Demod.thisBit > 0) Demod.shiftReg |= 0x200;
909
910 ++Demod.bitCount;
911
912 // 1 start 8 data 1 stop = 10
913 if (Demod.bitCount == 10) {
914
915 uint16_t s = Demod.shiftReg;
916
917 // stop bit == '1', start bit == '0'
918 if ((s & 0x200) && (s & 0x001) == 0 ) {
919 // left shift to drop the startbit
920 Demod.output[Demod.len] = (s >> 1) & 0xFF;
921 ++Demod.len;
922 Demod.state = DEMOD_AWAITING_START_BIT;
923 } else {
924 // this one is a bit hard, either its a correc byte or its unsynced.
925 Demod.state = DEMOD_UNSYNCD;
926 //Demod.endTime = GetCountSspClk();
927 LED_C_OFF();
928
929 // This is EOF (start, stop and all data bits == '0'
930 if (s == 0) return TRUE;
931 }
932 }
933 Demod.posCount = 0;
934 }
935 break;
936
937 default:
938 Demod.state = DEMOD_UNSYNCD;
939 LED_C_OFF();
940 break;
941 }
942 return FALSE;
943 }
944
945
946 /*
947 * Demodulate the samples we received from the tag, also log to tracebuffer
948 * quiet: set to 'TRUE' to disable debug output
949 */
950 static void GetTagSamplesFor14443bDemod() {
951 bool gotFrame = FALSE, finished = FALSE;
952 int lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
953 int ci = 0, cq = 0;
954 uint32_t time_0 = 0, time_stop = 0;
955
956 BigBuf_free();
957
958 // Set up the demodulator for tag -> reader responses.
959 DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
960
961 // The DMA buffer, used to stream samples from the FPGA
962 int8_t *dmaBuf = (int8_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE);
963 int8_t *upTo = dmaBuf;
964
965 // Setup and start DMA.
966 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE) ){
967 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
968 return;
969 }
970
971 // And put the FPGA in the appropriate mode
972 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
973
974 // get current clock
975 time_0 = GetCountSspClk();
976
977 // rx counter - dma counter? (how much?) & (mod) mask > 2. (since 2bytes at the time is read)
978 while ( !finished ) {
979
980 LED_A_INV();
981 WDT_HIT();
982
983 // LSB is a fpga signal bit.
984 ci = upTo[0] >> 1;
985 cq = upTo[1] >> 1;
986 upTo += 2;
987 lastRxCounter -= 2;
988
989 // restart DMA buffer to receive again.
990 if(upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) {
991 upTo = dmaBuf;
992 lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
993 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo;
994 AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE;
995 }
996
997 // https://github.com/Proxmark/proxmark3/issues/103
998 gotFrame = Handle14443bTagSamplesDemod(ci, cq);
999 time_stop = GetCountSspClk() - time_0;
1000
1001 finished = (time_stop > iso14b_timeout || gotFrame);
1002 }
1003
1004 FpgaDisableSscDma();
1005
1006 if ( upTo ) upTo = NULL;
1007
1008 if (MF_DBGLEVEL >= 3) {
1009 Dbprintf("Demod.state = %d, Demod.len = %u, PDC_RCR = %u",
1010 Demod.state,
1011 Demod.len,
1012 AT91C_BASE_PDC_SSC->PDC_RCR
1013 );
1014 }
1015
1016 // print the last batch of IQ values from FPGA
1017 if (MF_DBGLEVEL == 4)
1018 Dbhexdump(ISO14443B_DMA_BUFFER_SIZE, (uint8_t *)dmaBuf, FALSE);
1019
1020 if ( Demod.len > 0 )
1021 LogTrace(Demod.output, Demod.len, time_0, time_stop, NULL, FALSE);
1022 }
1023
1024
1025 //-----------------------------------------------------------------------------
1026 // Transmit the command (to the tag) that was placed in ToSend[].
1027 //-----------------------------------------------------------------------------
1028 static void TransmitFor14443b_AsReader(void) {
1029
1030 // we could been in following mode:
1031 // FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ
1032 // if its second call or more
1033
1034 // while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1035 // AT91C_BASE_SSC->SSC_THR = 0XFF;
1036 // }
1037
1038 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
1039 SpinDelay(40);
1040
1041 int c;
1042 volatile uint32_t b;
1043
1044 // What does this loop do? Is it TR1?
1045 // 0xFF = 8 bits of 1. 1 bit == 1Etu,..
1046 // loop 10 * 8 = 80 ETU of delay, with a non modulated signal. why?
1047 // 80*9 = 720us.
1048 for(c = 0; c < 50;) {
1049 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1050 AT91C_BASE_SSC->SSC_THR = 0xFF;
1051 ++c;
1052 }
1053 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1054 b = AT91C_BASE_SSC->SSC_RHR;
1055 (void)b;
1056 }
1057 }
1058
1059 // Send frame loop
1060 for(c = 0; c < ToSendMax;) {
1061 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1062 AT91C_BASE_SSC->SSC_THR = ToSend[c++];
1063 }
1064 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1065 b = AT91C_BASE_SSC->SSC_RHR;
1066 (void)b;
1067 }
1068 }
1069 //WaitForFpgaDelayQueueIsEmpty(delay);
1070 // We should wait here for the FPGA to send all bits.
1071 WDT_HIT();
1072 }
1073
1074 //-----------------------------------------------------------------------------
1075 // Code a layer 2 command (string of octets, including CRC) into ToSend[],
1076 // so that it is ready to transmit to the tag using TransmitFor14443b().
1077 //-----------------------------------------------------------------------------
1078 static void CodeIso14443bAsReader(const uint8_t *cmd, int len) {
1079 /*
1080 * Reader data transmission:
1081 * - no modulation ONES
1082 * - SOF
1083 * - Command, data and CRC_B
1084 * - EOF
1085 * - no modulation ONES
1086 *
1087 * 1 ETU == 1 BIT!
1088 * TR0 - 8 ETUS minimum.
1089 *
1090 * QUESTION: how long is a 1 or 0 in pulses in the xcorr_848 mode?
1091 * 1 "stuffbit" = 1ETU (9us)
1092 */
1093 int i;
1094 uint8_t b;
1095
1096 ToSendReset();
1097
1098 // Send SOF
1099 // 10-11 ETUs of ZERO
1100 for(i = 0; i < 10; ++i) ToSendStuffBit(0);
1101
1102 // 2-3 ETUs of ONE
1103 ToSendStuffBit(1);
1104 ToSendStuffBit(1);
1105 ToSendStuffBit(1);
1106
1107 // Sending cmd, LSB
1108 // from here we add BITS
1109 for(i = 0; i < len; ++i) {
1110 // Start bit
1111 ToSendStuffBit(0);
1112 // Data bits
1113 b = cmd[i];
1114 // if ( b & 1 ) ToSendStuffBit(1); else ToSendStuffBit(0);
1115 // if ( (b>>1) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1116 // if ( (b>>2) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1117 // if ( (b>>3) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1118 // if ( (b>>4) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1119 // if ( (b>>5) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1120 // if ( (b>>6) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1121 // if ( (b>>7) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1122
1123 ToSendStuffBit( b & 1);
1124 ToSendStuffBit( (b>>1) & 1);
1125 ToSendStuffBit( (b>>2) & 1);
1126 ToSendStuffBit( (b>>3) & 1);
1127 ToSendStuffBit( (b>>4) & 1);
1128 ToSendStuffBit( (b>>5) & 1);
1129 ToSendStuffBit( (b>>6) & 1);
1130 ToSendStuffBit( (b>>7) & 1);
1131
1132 // Stop bit
1133 ToSendStuffBit(1);
1134 // EGT extra guard time
1135 // For PCD it ranges 0-57us (1etu = 9us)
1136 ToSendStuffBit(1);
1137 ToSendStuffBit(1);
1138 ToSendStuffBit(1);
1139 }
1140
1141 // Send EOF
1142 // 10-11 ETUs of ZERO
1143 for(i = 0; i < 10; ++i) ToSendStuffBit(0);
1144
1145 // Transition time. TR0 - guard time
1146 // 8ETUS minum?
1147 // Per specification, Subcarrier must be stopped no later than 2 ETUs after EOF.
1148 // I'm guessing this is for the FPGA to be able to send all bits before we switch to listening mode
1149 for(i = 0; i < 32 ; ++i) ToSendStuffBit(1);
1150
1151 // TR1 - Synchronization time
1152 // Convert from last character reference to length
1153 ++ToSendMax;
1154 }
1155
1156
1157 /*
1158 * Convenience function to encode, transmit and trace iso 14443b comms
1159 */
1160 static void CodeAndTransmit14443bAsReader(const uint8_t *cmd, int len) {
1161
1162 uint32_t time_start = GetCountSspClk();
1163
1164 CodeIso14443bAsReader(cmd, len);
1165
1166 TransmitFor14443b_AsReader();
1167
1168 if(trigger) LED_A_ON();
1169
1170 LogTrace(cmd, len, time_start, GetCountSspClk()-time_start, NULL, TRUE);
1171 }
1172
1173 /* Sends an APDU to the tag
1174 * TODO: check CRC and preamble
1175 */
1176 uint8_t iso14443b_apdu(uint8_t const *message, size_t message_length, uint8_t *response)
1177 {
1178 uint8_t crc[2] = {0x00, 0x00};
1179 uint8_t message_frame[message_length + 4];
1180 // PCB
1181 message_frame[0] = 0x0A | pcb_blocknum;
1182 pcb_blocknum ^= 1;
1183 // CID
1184 message_frame[1] = 0;
1185 // INF
1186 memcpy(message_frame + 2, message, message_length);
1187 // EDC (CRC)
1188 ComputeCrc14443(CRC_14443_B, message_frame, message_length + 2, &message_frame[message_length + 2], &message_frame[message_length + 3]);
1189 // send
1190 CodeAndTransmit14443bAsReader(message_frame, message_length + 4); //no
1191 // get response
1192 GetTagSamplesFor14443bDemod(); //no
1193 if(Demod.len < 3)
1194 return 0;
1195
1196 // VALIDATE CRC
1197 ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
1198 if ( crc[0] != Demod.output[Demod.len-2] || crc[1] != Demod.output[Demod.len-1] )
1199 return 0;
1200
1201 // copy response contents
1202 if(response != NULL)
1203 memcpy(response, Demod.output, Demod.len);
1204
1205 return Demod.len;
1206 }
1207
1208 /**
1209 * SRx Initialise.
1210 */
1211 uint8_t iso14443b_select_srx_card(iso14b_card_select_t *card )
1212 {
1213 // INITIATE command: wake up the tag using the INITIATE
1214 static const uint8_t init_srx[] = { ISO14443B_INITIATE, 0x00, 0x97, 0x5b };
1215 // SELECT command (with space for CRC)
1216 uint8_t select_srx[] = { ISO14443B_SELECT, 0x00, 0x00, 0x00};
1217 // temp to calc crc.
1218 uint8_t crc[2] = {0x00, 0x00};
1219
1220 CodeAndTransmit14443bAsReader(init_srx, sizeof(init_srx));
1221 GetTagSamplesFor14443bDemod(); //no
1222
1223 if (Demod.len == 0) return 2;
1224
1225 // Randomly generated Chip ID
1226 if (card) card->chipid = Demod.output[0];
1227
1228 select_srx[1] = Demod.output[0];
1229
1230 ComputeCrc14443(CRC_14443_B, select_srx, 2, &select_srx[2], &select_srx[3]);
1231 CodeAndTransmit14443bAsReader(select_srx, sizeof(select_srx));
1232 GetTagSamplesFor14443bDemod(); //no
1233
1234 if (Demod.len != 3) return 2;
1235
1236 // Check the CRC of the answer:
1237 ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2 , &crc[0], &crc[1]);
1238 if(crc[0] != Demod.output[1] || crc[1] != Demod.output[2]) return 3;
1239
1240 // Check response from the tag: should be the same UID as the command we just sent:
1241 if (select_srx[1] != Demod.output[0]) return 1;
1242
1243 // First get the tag's UID:
1244 select_srx[0] = ISO14443B_GET_UID;
1245
1246 ComputeCrc14443(CRC_14443_B, select_srx, 1 , &select_srx[1], &select_srx[2]);
1247 CodeAndTransmit14443bAsReader(select_srx, 3); // Only first three bytes for this one
1248 GetTagSamplesFor14443bDemod(); //no
1249
1250 if (Demod.len != 10) return 2;
1251
1252 // The check the CRC of the answer
1253 ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
1254 if(crc[0] != Demod.output[8] || crc[1] != Demod.output[9]) return 3;
1255
1256 if (card) {
1257 card->uidlen = 8;
1258 memcpy(card->uid, Demod.output, 8);
1259 }
1260
1261 return 0;
1262 }
1263 /* Perform the ISO 14443 B Card Selection procedure
1264 * Currently does NOT do any collision handling.
1265 * It expects 0-1 cards in the device's range.
1266 * TODO: Support multiple cards (perform anticollision)
1267 * TODO: Verify CRC checksums
1268 */
1269 uint8_t iso14443b_select_card(iso14b_card_select_t *card )
1270 {
1271 // WUPB command (including CRC)
1272 // Note: WUPB wakes up all tags, REQB doesn't wake up tags in HALT state
1273 static const uint8_t wupb[] = { ISO14443B_REQB, 0x00, 0x08, 0x39, 0x73 };
1274 // ATTRIB command (with space for CRC)
1275 uint8_t attrib[] = { ISO14443B_ATTRIB, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00};
1276
1277 // temp to calc crc.
1278 uint8_t crc[2] = {0x00, 0x00};
1279
1280 // first, wake up the tag
1281 CodeAndTransmit14443bAsReader(wupb, sizeof(wupb));
1282 GetTagSamplesFor14443bDemod(); //select_card
1283
1284 // ATQB too short?
1285 if (Demod.len < 14) return 2;
1286
1287 // VALIDATE CRC
1288 ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
1289 if ( crc[0] != Demod.output[12] || crc[1] != Demod.output[13] )
1290 return 3;
1291
1292 if (card) {
1293 card->uidlen = 4;
1294 memcpy(card->uid, Demod.output+1, 4);
1295 memcpy(card->atqb, Demod.output+5, 7);
1296 }
1297
1298 // copy the PUPI to ATTRIB ( PUPI == UID )
1299 memcpy(attrib + 1, Demod.output + 1, 4);
1300
1301 // copy the protocol info from ATQB (Protocol Info -> Protocol_Type) into ATTRIB (Param 3)
1302 attrib[7] = Demod.output[10] & 0x0F;
1303 ComputeCrc14443(CRC_14443_B, attrib, 9, attrib + 9, attrib + 10);
1304
1305 CodeAndTransmit14443bAsReader(attrib, sizeof(attrib));
1306 GetTagSamplesFor14443bDemod();//select_card
1307
1308 // Answer to ATTRIB too short?
1309 if(Demod.len < 3) return 2;
1310
1311 // VALIDATE CRC
1312 ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
1313 if ( crc[0] != Demod.output[1] || crc[1] != Demod.output[2] )
1314 return 3;
1315
1316 if (card) {
1317
1318 // CID
1319 card->cid = Demod.output[0];
1320
1321 // MAX FRAME
1322 uint16_t maxFrame = card->atqb[5] >> 4;
1323 if (maxFrame < 5) maxFrame = 8 * maxFrame + 16;
1324 else if (maxFrame == 5) maxFrame = 64;
1325 else if (maxFrame == 6) maxFrame = 96;
1326 else if (maxFrame == 7) maxFrame = 128;
1327 else if (maxFrame == 8) maxFrame = 256;
1328 else maxFrame = 257;
1329 iso14b_set_maxframesize(maxFrame);
1330
1331 // FWT
1332 uint8_t fwt = card->atqb[6] >> 4;
1333 if ( fwt < 16 ){
1334 uint32_t fwt_time = (302 << fwt);
1335 iso14b_set_timeout( fwt_time);
1336 }
1337 }
1338 // reset PCB block number
1339 pcb_blocknum = 0;
1340 return 0;
1341 }
1342
1343 // Set up ISO 14443 Type B communication (similar to iso14443a_setup)
1344 // field is setup for "Sending as Reader"
1345 void iso14443b_setup() {
1346 if (MF_DBGLEVEL > 3) Dbprintf("iso1443b_setup Enter");
1347 LEDsoff();
1348 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1349 //BigBuf_free();
1350 //BigBuf_Clear_ext(false);
1351
1352 // Initialize Demod and Uart structs
1353 DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
1354 UartInit(BigBuf_malloc(MAX_FRAME_SIZE));
1355
1356 // connect Demodulated Signal to ADC:
1357 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1358
1359 // Set up the synchronous serial port
1360 FpgaSetupSsc();
1361
1362 // Signal field is on with the appropriate LED
1363 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
1364 SpinDelay(100);
1365
1366 // Start the timer
1367 StartCountSspClk();
1368
1369 LED_D_ON();
1370 if (MF_DBGLEVEL > 3) Dbprintf("iso1443b_setup Exit");
1371 }
1372
1373 //-----------------------------------------------------------------------------
1374 // Read a SRI512 ISO 14443B tag.
1375 //
1376 // SRI512 tags are just simple memory tags, here we're looking at making a dump
1377 // of the contents of the memory. No anticollision algorithm is done, we assume
1378 // we have a single tag in the field.
1379 //
1380 // I tried to be systematic and check every answer of the tag, every CRC, etc...
1381 //-----------------------------------------------------------------------------
1382 void ReadSTMemoryIso14443b(uint8_t numofblocks)
1383 {
1384 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1385
1386 // Make sure that we start from off, since the tags are stateful;
1387 // confusing things will happen if we don't reset them between reads.
1388 switch_off(); // before ReadStMemory
1389
1390 set_tracing(TRUE);
1391
1392 uint8_t i = 0x00;
1393
1394 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1395 FpgaSetupSsc();
1396
1397 // Now give it time to spin up.
1398 // Signal field is on with the appropriate LED
1399 LED_D_ON();
1400 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
1401 SpinDelay(20);
1402
1403 // First command: wake up the tag using the INITIATE command
1404 uint8_t cmd1[] = {ISO14443B_INITIATE, 0x00, 0x97, 0x5b};
1405 CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1)); //no
1406 GetTagSamplesFor14443bDemod(); // no
1407
1408 if (Demod.len == 0) {
1409 DbpString("No response from tag");
1410 set_tracing(FALSE);
1411 return;
1412 } else {
1413 Dbprintf("Randomly generated Chip ID (+ 2 byte CRC): %02x %02x %02x",
1414 Demod.output[0], Demod.output[1], Demod.output[2]);
1415 }
1416
1417 // There is a response, SELECT the uid
1418 DbpString("Now SELECT tag:");
1419 cmd1[0] = ISO14443B_SELECT; // 0x0E is SELECT
1420 cmd1[1] = Demod.output[0];
1421 ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
1422 CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1)); //no
1423 GetTagSamplesFor14443bDemod(); //no
1424 if (Demod.len != 3) {
1425 Dbprintf("Expected 3 bytes from tag, got %d", Demod.len);
1426 set_tracing(FALSE);
1427 return;
1428 }
1429 // Check the CRC of the answer:
1430 ComputeCrc14443(CRC_14443_B, Demod.output, 1 , &cmd1[2], &cmd1[3]);
1431 if(cmd1[2] != Demod.output[1] || cmd1[3] != Demod.output[2]) {
1432 DbpString("CRC Error reading select response.");
1433 set_tracing(FALSE);
1434 return;
1435 }
1436 // Check response from the tag: should be the same UID as the command we just sent:
1437 if (cmd1[1] != Demod.output[0]) {
1438 Dbprintf("Bad response to SELECT from Tag, aborting: %02x %02x", cmd1[1], Demod.output[0]);
1439 set_tracing(FALSE);
1440 return;
1441 }
1442
1443 // Tag is now selected,
1444 // First get the tag's UID:
1445 cmd1[0] = ISO14443B_GET_UID;
1446 ComputeCrc14443(CRC_14443_B, cmd1, 1 , &cmd1[1], &cmd1[2]);
1447 CodeAndTransmit14443bAsReader(cmd1, 3); // no -- Only first three bytes for this one
1448 GetTagSamplesFor14443bDemod(); //no
1449 if (Demod.len != 10) {
1450 Dbprintf("Expected 10 bytes from tag, got %d", Demod.len);
1451 set_tracing(FALSE);
1452 return;
1453 }
1454 // The check the CRC of the answer (use cmd1 as temporary variable):
1455 ComputeCrc14443(CRC_14443_B, Demod.output, 8, &cmd1[2], &cmd1[3]);
1456 if(cmd1[2] != Demod.output[8] || cmd1[3] != Demod.output[9]) {
1457 Dbprintf("CRC Error reading block! Expected: %04x got: %04x",
1458 (cmd1[2]<<8)+cmd1[3], (Demod.output[8]<<8)+Demod.output[9]);
1459 // Do not return;, let's go on... (we should retry, maybe ?)
1460 }
1461 Dbprintf("Tag UID (64 bits): %08x %08x",
1462 (Demod.output[7]<<24) + (Demod.output[6]<<16) + (Demod.output[5]<<8) + Demod.output[4],
1463 (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0]);
1464
1465 // Now loop to read all 16 blocks, address from 0 to last block
1466 Dbprintf("Tag memory dump, block 0 to %d", numofblocks);
1467 cmd1[0] = 0x08;
1468 i = 0x00;
1469 ++numofblocks;
1470
1471 for (;;) {
1472 if (i == numofblocks) {
1473 DbpString("System area block (0xff):");
1474 i = 0xff;
1475 }
1476 cmd1[1] = i;
1477 ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
1478 CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1)); //no
1479 GetTagSamplesFor14443bDemod(); //no
1480
1481 if (Demod.len != 6) { // Check if we got an answer from the tag
1482 DbpString("Expected 6 bytes from tag, got less...");
1483 return;
1484 }
1485 // The check the CRC of the answer (use cmd1 as temporary variable):
1486 ComputeCrc14443(CRC_14443_B, Demod.output, 4, &cmd1[2], &cmd1[3]);
1487 if(cmd1[2] != Demod.output[4] || cmd1[3] != Demod.output[5]) {
1488 Dbprintf("CRC Error reading block! Expected: %04x got: %04x",
1489 (cmd1[2]<<8)+cmd1[3], (Demod.output[4]<<8)+Demod.output[5]);
1490 // Do not return;, let's go on... (we should retry, maybe ?)
1491 }
1492 // Now print out the memory location:
1493 Dbprintf("Address=%02x, Contents=%08x, CRC=%04x", i,
1494 (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0],
1495 (Demod.output[4]<<8)+Demod.output[5]);
1496
1497 if (i == 0xff) break;
1498 ++i;
1499 }
1500
1501 set_tracing(FALSE);
1502 }
1503
1504
1505 static void iso1444b_setup_snoop(void){
1506 if (MF_DBGLEVEL > 3) Dbprintf("iso1443b_setup_snoop Enter");
1507 LEDsoff();
1508 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1509 BigBuf_free();
1510 BigBuf_Clear_ext(false);
1511 clear_trace();//setup snoop
1512 set_tracing(TRUE);
1513
1514 // Initialize Demod and Uart structs
1515 DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
1516 UartInit(BigBuf_malloc(MAX_FRAME_SIZE));
1517
1518 if (MF_DBGLEVEL > 1) {
1519 // Print debug information about the buffer sizes
1520 Dbprintf("Snooping buffers initialized:");
1521 Dbprintf(" Trace: %i bytes", BigBuf_max_traceLen());
1522 Dbprintf(" Reader -> tag: %i bytes", MAX_FRAME_SIZE);
1523 Dbprintf(" tag -> Reader: %i bytes", MAX_FRAME_SIZE);
1524 Dbprintf(" DMA: %i bytes", ISO14443B_DMA_BUFFER_SIZE);
1525 }
1526
1527 // connect Demodulated Signal to ADC:
1528 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1529
1530 // Setup for the DMA.
1531 FpgaSetupSsc();
1532
1533 // Set FPGA in the appropriate mode
1534 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | FPGA_HF_READER_RX_XCORR_SNOOP);
1535 SpinDelay(20);
1536
1537 // Start the SSP timer
1538 StartCountSspClk();
1539 if (MF_DBGLEVEL > 3) Dbprintf("iso1443b_setup_snoop Exit");
1540 }
1541
1542 //=============================================================================
1543 // Finally, the `sniffer' combines elements from both the reader and
1544 // simulated tag, to show both sides of the conversation.
1545 //=============================================================================
1546
1547 //-----------------------------------------------------------------------------
1548 // Record the sequence of commands sent by the reader to the tag, with
1549 // triggering so that we start recording at the point that the tag is moved
1550 // near the reader.
1551 //-----------------------------------------------------------------------------
1552 /*
1553 * Memory usage for this function, (within BigBuf)
1554 * Last Received command (reader->tag) - MAX_FRAME_SIZE
1555 * Last Received command (tag->reader) - MAX_FRAME_SIZE
1556 * DMA Buffer - ISO14443B_DMA_BUFFER_SIZE
1557 * Demodulated samples received - all the rest
1558 */
1559 void RAMFUNC SnoopIso14443b(void) {
1560
1561 uint32_t time_0 = 0, time_start = 0, time_stop = 0;
1562 int ci = 0, cq = 0;
1563 int lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
1564
1565 // We won't start recording the frames that we acquire until we trigger;
1566 // a good trigger condition to get started is probably when we see a
1567 // response from the tag.
1568 bool triggered = TRUE; // TODO: set and evaluate trigger condition
1569 bool TagIsActive = FALSE;
1570 bool ReaderIsActive = FALSE;
1571
1572 iso1444b_setup_snoop();
1573
1574 // The DMA buffer, used to stream samples from the FPGA
1575 int8_t *dmaBuf = (int8_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE);
1576 int8_t *upTo = dmaBuf;
1577
1578 // Setup and start DMA.
1579 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE) ){
1580 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
1581 BigBuf_free();
1582 return;
1583 }
1584
1585 time_0 = GetCountSspClk();
1586
1587 // And now we loop, receiving samples.
1588 for(;;) {
1589
1590 WDT_HIT();
1591
1592 ci = upTo[0];
1593 cq = upTo[1];
1594 upTo += 2;
1595 lastRxCounter -= 2;
1596
1597 if (upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) {
1598 upTo = dmaBuf;
1599 lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
1600 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
1601 AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE;
1602
1603 if (!tracing) {
1604 if (MF_DBGLEVEL >= 2) DbpString("Trace full");
1605 break;
1606 }
1607
1608 if (BUTTON_PRESS()) {
1609 if (MF_DBGLEVEL >= 2) DbpString("cancelled");
1610 break;
1611 }
1612 }
1613
1614 if (!TagIsActive) {
1615
1616 LED_A_ON();
1617
1618 // no need to try decoding reader data if the tag is sending
1619 if (Handle14443bReaderUartBit(ci & 0x01)) {
1620
1621 time_stop = GetCountSspClk() - time_0;
1622
1623 if (triggered)
1624 LogTrace(Uart.output, Uart.byteCnt, time_start, time_stop, NULL, TRUE);
1625
1626 /* And ready to receive another command. */
1627 UartReset();
1628 /* And also reset the demod code, which might have been */
1629 /* false-triggered by the commands from the reader. */
1630 DemodReset();
1631 } else {
1632 time_start = GetCountSspClk() - time_0;
1633 }
1634
1635 if (Handle14443bReaderUartBit(cq & 0x01)) {
1636
1637 time_stop = GetCountSspClk() - time_0;
1638
1639 if (triggered)
1640 LogTrace(Uart.output, Uart.byteCnt, time_start, time_stop, NULL, TRUE);
1641
1642 /* And ready to receive another command. */
1643 UartReset();
1644 /* And also reset the demod code, which might have been */
1645 /* false-triggered by the commands from the reader. */
1646 DemodReset();
1647 } else {
1648 time_start = GetCountSspClk() - time_0;
1649 }
1650 ReaderIsActive = (Uart.state > STATE_GOT_FALLING_EDGE_OF_SOF);
1651 LED_A_OFF();
1652 }
1653
1654 if (!ReaderIsActive) {
1655 // no need to try decoding tag data if the reader is sending - and we cannot afford the time
1656 // is this | 0x01 the error? & 0xfe in https://github.com/Proxmark/proxmark3/issues/103
1657 // LSB is a fpga signal bit.
1658 if (Handle14443bTagSamplesDemod(ci >> 1, cq >> 1)) {
1659
1660 time_stop = GetCountSspClk() - time_0;
1661
1662 LogTrace(Demod.output, Demod.len, time_start, time_stop, NULL, FALSE);
1663
1664 triggered = TRUE;
1665
1666 // And ready to receive another response.
1667 DemodReset();
1668 } else {
1669 time_start = GetCountSspClk() - time_0;
1670 }
1671 TagIsActive = (Demod.state > DEMOD_GOT_FALLING_EDGE_OF_SOF);
1672 }
1673 }
1674
1675 switch_off(); // Snoop
1676
1677 DbpString("Snoop statistics:");
1678 Dbprintf(" Uart State: %x ByteCount: %i ByteCountMax: %i", Uart.state, Uart.byteCnt, Uart.byteCntMax);
1679 Dbprintf(" Trace length: %i", BigBuf_get_traceLen());
1680
1681 // free mem refs.
1682 if ( upTo ) upTo = NULL;
1683
1684 // Uart.byteCntMax should be set with ATQB value..
1685 }
1686
1687 void iso14b_set_trigger(bool enable) {
1688 trigger = enable;
1689 }
1690
1691 /*
1692 * Send raw command to tag ISO14443B
1693 * @Input
1694 * param flags enum ISO14B_COMMAND. (mifare.h)
1695 * len len of buffer data
1696 * data buffer with bytes to send
1697 *
1698 * @Output
1699 * none
1700 *
1701 */
1702 void SendRawCommand14443B_Ex(UsbCommand *c)
1703 {
1704 iso14b_command_t param = c->arg[0];
1705 size_t len = c->arg[1] & 0xffff;
1706 uint8_t *cmd = c->d.asBytes;
1707 uint8_t status = 0;
1708 uint32_t sendlen = sizeof(iso14b_card_select_t);
1709 uint8_t buf[USB_CMD_DATA_SIZE] = {0x00};
1710
1711 if (MF_DBGLEVEL > 3) Dbprintf("14b raw: param, %04x", param );
1712
1713 // turn on trigger (LED_A)
1714 if ((param & ISO14B_REQUEST_TRIGGER) == ISO14B_REQUEST_TRIGGER)
1715 iso14b_set_trigger(TRUE);
1716
1717 if ((param & ISO14B_CONNECT) == ISO14B_CONNECT) {
1718 // Make sure that we start from off, since the tags are stateful;
1719 // confusing things will happen if we don't reset them between reads.
1720 //switch_off(); // before connect in raw
1721 iso14443b_setup();
1722 }
1723
1724 set_tracing(TRUE);
1725
1726 if ((param & ISO14B_SELECT_STD) == ISO14B_SELECT_STD) {
1727 iso14b_card_select_t *card = (iso14b_card_select_t*)buf;
1728 status = iso14443b_select_card(card);
1729 cmd_send(CMD_ACK, status, sendlen, 0, buf, sendlen);
1730 // 0: OK 2: attrib fail, 3:crc fail,
1731 if ( status > 0 ) return;
1732 }
1733
1734 if ((param & ISO14B_SELECT_SR) == ISO14B_SELECT_SR) {
1735 iso14b_card_select_t *card = (iso14b_card_select_t*)buf;
1736 status = iso14443b_select_srx_card(card);
1737 cmd_send(CMD_ACK, status, sendlen, 0, buf, sendlen);
1738 // 0: OK 2: attrib fail, 3:crc fail,
1739 if ( status > 0 ) return;
1740 }
1741
1742 if ((param & ISO14B_APDU) == ISO14B_APDU) {
1743 status = iso14443b_apdu(cmd, len, buf);
1744 cmd_send(CMD_ACK, status, status, 0, buf, status);
1745 }
1746
1747 if ((param & ISO14B_RAW) == ISO14B_RAW) {
1748 if((param & ISO14B_APPEND_CRC) == ISO14B_APPEND_CRC) {
1749 AppendCrc14443b(cmd, len);
1750 len += 2;
1751 }
1752
1753 CodeAndTransmit14443bAsReader(cmd, len); // raw
1754 GetTagSamplesFor14443bDemod(); // raw
1755
1756 sendlen = MIN(Demod.len, USB_CMD_DATA_SIZE);
1757 status = (Demod.len > 0) ? 0 : 1;
1758 cmd_send(CMD_ACK, status, sendlen, 0, Demod.output, sendlen);
1759 }
1760
1761 // turn off trigger (LED_A)
1762 if ((param & ISO14B_REQUEST_TRIGGER) == ISO14B_REQUEST_TRIGGER)
1763 iso14b_set_trigger(FALSE);
1764
1765 // turn off antenna et al
1766 // we don't send a HALT command.
1767 if ((param & ISO14B_DISCONNECT) == ISO14B_DISCONNECT) {
1768 if (MF_DBGLEVEL > 3) Dbprintf("disconnect");
1769 switch_off(); // disconnect raw
1770 } else {
1771 //FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
1772 }
1773
1774 }
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