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CHG: iso14443b.c got some more love. using the "hf 14b raw" command gives now...
[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 # define FWT_TIMEOUT_14B 60000
15 #endif
16 #ifndef ISO14443B_DMA_BUFFER_SIZE
17 # define ISO14443B_DMA_BUFFER_SIZE 256
18 #endif
19 #ifndef RECEIVE_MASK
20 # define RECEIVE_MASK (ISO14443B_DMA_BUFFER_SIZE-1)
21 #endif
22
23 // Guard Time (per 14443-2)
24 #ifndef TR0
25 # define TR0 0
26 #endif
27
28 // Synchronization time (per 14443-2)
29 #ifndef TR1
30 # define TR1 0
31 #endif
32 // Frame Delay Time PICC to PCD (per 14443-3 Amendment 1)
33 #ifndef TR2
34 # define TR2 0
35 #endif
36
37 // 4sample
38 #define SEND4STUFFBIT(x) ToSendStuffBit(x);ToSendStuffBit(x);ToSendStuffBit(x);ToSendStuffBit(x);
39 //#define SEND4STUFFBIT(x) ToSendStuffBit(x);
40
41 static void switch_off(void);
42
43 // the block number for the ISO14443-4 PCB (used with APDUs)
44 static uint8_t pcb_blocknum = 0;
45
46 static uint32_t iso14b_timeout = FWT_TIMEOUT_14B;
47 // param timeout is in ftw_
48 void iso14b_set_timeout(uint32_t timeout) {
49 // 9.4395us = 1etu.
50 // clock is about 1.5 us
51 iso14b_timeout = timeout;
52 if(MF_DBGLEVEL >= 2) Dbprintf("ISO14443B Timeout set to %ld fwt", iso14b_timeout);
53 }
54
55 static void switch_off(void){
56 if (MF_DBGLEVEL > 3) Dbprintf("switch_off");
57 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
58 SpinDelay(100);
59 FpgaDisableSscDma();
60 set_tracing(FALSE);
61 LEDsoff();
62 }
63
64 //=============================================================================
65 // An ISO 14443 Type B tag. We listen for commands from the reader, using
66 // a UART kind of thing that's implemented in software. When we get a
67 // frame (i.e., a group of bytes between SOF and EOF), we check the CRC.
68 // If it's good, then we can do something appropriate with it, and send
69 // a response.
70 //=============================================================================
71
72
73 //-----------------------------------------------------------------------------
74 // The software UART that receives commands from the reader, and its state variables.
75 //-----------------------------------------------------------------------------
76 static struct {
77 enum {
78 STATE_UNSYNCD,
79 STATE_GOT_FALLING_EDGE_OF_SOF,
80 STATE_AWAITING_START_BIT,
81 STATE_RECEIVING_DATA
82 } state;
83 uint16_t shiftReg;
84 int bitCnt;
85 int byteCnt;
86 int byteCntMax;
87 int posCnt;
88 uint8_t *output;
89 } Uart;
90
91 static void UartReset() {
92 Uart.state = STATE_UNSYNCD;
93 Uart.shiftReg = 0;
94 Uart.bitCnt = 0;
95 Uart.byteCnt = 0;
96 Uart.byteCntMax = MAX_FRAME_SIZE;
97 Uart.posCnt = 0;
98 }
99
100 static void UartInit(uint8_t *data) {
101 Uart.output = data;
102 UartReset();
103 // memset(Uart.output, 0x00, MAX_FRAME_SIZE);
104 }
105
106 //-----------------------------------------------------------------------------
107 // The software Demod that receives commands from the tag, and its state variables.
108 //-----------------------------------------------------------------------------
109 static struct {
110 enum {
111 DEMOD_UNSYNCD,
112 DEMOD_PHASE_REF_TRAINING,
113 DEMOD_AWAITING_FALLING_EDGE_OF_SOF,
114 DEMOD_GOT_FALLING_EDGE_OF_SOF,
115 DEMOD_AWAITING_START_BIT,
116 DEMOD_RECEIVING_DATA
117 } state;
118 uint16_t bitCount;
119 int posCount;
120 int thisBit;
121 /* this had been used to add RSSI (Received Signal Strength Indication) to traces. Currently not implemented.
122 int metric;
123 int metricN;
124 */
125 uint16_t shiftReg;
126 uint8_t *output;
127 uint16_t len;
128 int sumI;
129 int sumQ;
130 uint32_t startTime, endTime;
131 } Demod;
132
133 // Clear out the state of the "UART" that receives from the tag.
134 static void DemodReset() {
135 Demod.state = DEMOD_UNSYNCD;
136 Demod.bitCount = 0;
137 Demod.posCount = 0;
138 Demod.thisBit = 0;
139 Demod.shiftReg = 0;
140 Demod.len = 0;
141 Demod.sumI = 0;
142 Demod.sumQ = 0;
143 Demod.startTime = 0;
144 Demod.endTime = 0;
145 }
146
147 static void DemodInit(uint8_t *data) {
148 Demod.output = data;
149 DemodReset();
150 // memset(Demod.output, 0x00, MAX_FRAME_SIZE);
151 }
152
153 void AppendCrc14443b(uint8_t* data, int len) {
154 ComputeCrc14443(CRC_14443_B, data, len, data+len, data+len+1);
155 }
156
157 //-----------------------------------------------------------------------------
158 // Code up a string of octets at layer 2 (including CRC, we don't generate
159 // that here) so that they can be transmitted to the reader. Doesn't transmit
160 // them yet, just leaves them ready to send in ToSend[].
161 //-----------------------------------------------------------------------------
162 static void CodeIso14443bAsTag(const uint8_t *cmd, int len) {
163 /* ISO 14443 B
164 *
165 * Reader to card | ASK - Amplitude Shift Keying Modulation (PCD to PICC for Type B) (NRZ-L encodig)
166 * Card to reader | BPSK - Binary Phase Shift Keying Modulation, (PICC to PCD for Type B)
167 *
168 * fc - carrier frequency 13.56mHz
169 * TR0 - Guard Time per 14443-2
170 * TR1 - Synchronization Time per 14443-2
171 * TR2 - PICC to PCD Frame Delay Time (per 14443-3 Amendment 1)
172 *
173 * Elementary Time Unit (ETU) is
174 * - 128 Carrier Cycles (9.4395 µS) = 8 Subcarrier Units
175 * - 1 ETU = 1 bit
176 * - 10 ETU = 1 startbit, 8 databits, 1 stopbit (10bits length)
177 * - startbit is a 0
178 * - stopbit is a 1
179 *
180 * Start of frame (SOF) is
181 * - [10-11] ETU of ZEROS, unmodulated time
182 * - [2-3] ETU of ONES,
183 *
184 * End of frame (EOF) is
185 * - [10-11] ETU of ZEROS, unmodulated time
186 *
187 * -TO VERIFY THIS BELOW-
188 * The mode FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_BPSK which we use to simulate tag
189 * works like this:
190 * - A 1-bit input to the FPGA becomes 8 pulses at 847.5kHz (9.44µS)
191 * - A 0-bit input to the FPGA becomes an unmodulated time of 9.44µS
192 *
193 *
194 *
195 * Card sends data ub 847.e kHz subcarrier
196 * 848k = 9.44µS = 128 fc
197 * 424k = 18.88µS = 256 fc
198 * 212k = 37.76µS = 512 fc
199 * 106k = 75.52µS = 1024 fc
200 *
201 * Reader data transmission:
202 * - no modulation ONES
203 * - SOF
204 * - Command, data and CRC_B
205 * - EOF
206 * - no modulation ONES
207 *
208 * Card data transmission
209 * - TR1
210 * - SOF
211 * - data (each bytes is: 1startbit,8bits, 1stopbit)
212 * - CRC_B
213 * - EOF
214 *
215 * FPGA implementation :
216 * At this point only Type A is implemented. This means that we are using a
217 * bit rate of 106 kbit/s, or fc/128. Oversample by 4, which ought to make
218 * things practical for the ARM (fc/32, 423.8 kbits/s, ~50 kbytes/s)
219 *
220 */
221
222 int i,j;
223 uint8_t b;
224
225 ToSendReset();
226
227 // Transmit a burst of ones, as the initial thing that lets the
228 // reader get phase sync.
229 // This loop is TR1, per specification
230 // TR1 minimum must be > 80/fs
231 // TR1 maximum 200/fs
232 // 80/fs < TR1 < 200/fs
233 // 10 ETU < TR1 < 24 ETU
234
235 // Send SOF.
236 // 10-11 ETU * 4times samples ZEROS
237 for(i = 0; i < 10; i++) { SEND4STUFFBIT(0); }
238 //for(i = 0; i < 10; i++) { ToSendStuffBit(0); }
239
240 // 2-3 ETU * 4times samples ONES
241 for(i = 0; i < 3; i++) { SEND4STUFFBIT(1); }
242 //for(i = 0; i < 3; i++) { ToSendStuffBit(1); }
243
244 // data
245 for(i = 0; i < len; ++i) {
246
247 // Start bit
248 SEND4STUFFBIT(0);
249 //ToSendStuffBit(0);
250
251 // Data bits
252 b = cmd[i];
253 for(j = 0; j < 8; ++j) {
254 if(b & 1) {
255 SEND4STUFFBIT(1);
256 //ToSendStuffBit(1);
257 } else {
258 SEND4STUFFBIT(0);
259 //ToSendStuffBit(0);
260 }
261 b >>= 1;
262 }
263
264 // Stop bit
265 SEND4STUFFBIT(1);
266 //ToSendStuffBit(1);
267
268 // Extra Guard bit
269 // For PICC it ranges 0-18us (1etu = 9us)
270 SEND4STUFFBIT(1);
271 //ToSendStuffBit(1);
272 }
273
274 // Send EOF.
275 // 10-11 ETU * 4 sample rate = ZEROS
276 for(i = 0; i < 10; i++) { SEND4STUFFBIT(0); }
277 //for(i = 0; i < 10; i++) { ToSendStuffBit(0); }
278
279 // why this?
280 for(i = 0; i < 40; i++) { SEND4STUFFBIT(1); }
281 //for(i = 0; i < 40; i++) { ToSendStuffBit(1); }
282
283 // Convert from last byte pos to length
284 ++ToSendMax;
285 }
286
287
288 /* Receive & handle a bit coming from the reader.
289 *
290 * This function is called 4 times per bit (every 2 subcarrier cycles).
291 * Subcarrier frequency fs is 848kHz, 1/fs = 1,18us, i.e. function is called every 2,36us
292 *
293 * LED handling:
294 * LED A -> ON once we have received the SOF and are expecting the rest.
295 * LED A -> OFF once we have received EOF or are in error state or unsynced
296 *
297 * Returns: true if we received a EOF
298 * false if we are still waiting for some more
299 */
300 static RAMFUNC int Handle14443bReaderUartBit(uint8_t bit) {
301 switch(Uart.state) {
302 case STATE_UNSYNCD:
303 if(!bit) {
304 // we went low, so this could be the beginning of an SOF
305 Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF;
306 Uart.posCnt = 0;
307 Uart.bitCnt = 0;
308 }
309 break;
310
311 case STATE_GOT_FALLING_EDGE_OF_SOF:
312 Uart.posCnt++;
313 if(Uart.posCnt == 2) { // sample every 4 1/fs in the middle of a bit
314 if(bit) {
315 if(Uart.bitCnt > 9) {
316 // we've seen enough consecutive
317 // zeros that it's a valid SOF
318 Uart.posCnt = 0;
319 Uart.byteCnt = 0;
320 Uart.state = STATE_AWAITING_START_BIT;
321 LED_A_ON(); // Indicate we got a valid SOF
322 } else {
323 // didn't stay down long enough
324 // before going high, error
325 Uart.state = STATE_UNSYNCD;
326 }
327 } else {
328 // do nothing, keep waiting
329 }
330 Uart.bitCnt++;
331 }
332 if(Uart.posCnt >= 4) Uart.posCnt = 0;
333 if(Uart.bitCnt > 12) {
334 // Give up if we see too many zeros without
335 // a one, too.
336 LED_A_OFF();
337 Uart.state = STATE_UNSYNCD;
338 }
339 break;
340
341 case STATE_AWAITING_START_BIT:
342 Uart.posCnt++;
343 if(bit) {
344 if(Uart.posCnt > 50/2) { // max 57us between characters = 49 1/fs, max 3 etus after low phase of SOF = 24 1/fs
345 // stayed high for too long between
346 // characters, error
347 Uart.state = STATE_UNSYNCD;
348 }
349 } else {
350 // falling edge, this starts the data byte
351 Uart.posCnt = 0;
352 Uart.bitCnt = 0;
353 Uart.shiftReg = 0;
354 Uart.state = STATE_RECEIVING_DATA;
355 }
356 break;
357
358 case STATE_RECEIVING_DATA:
359 Uart.posCnt++;
360 if(Uart.posCnt == 2) {
361 // time to sample a bit
362 Uart.shiftReg >>= 1;
363 if(bit) {
364 Uart.shiftReg |= 0x200;
365 }
366 Uart.bitCnt++;
367 }
368 if(Uart.posCnt >= 4) {
369 Uart.posCnt = 0;
370 }
371 if(Uart.bitCnt == 10) {
372 if((Uart.shiftReg & 0x200) && !(Uart.shiftReg & 0x001))
373 {
374 // this is a data byte, with correct
375 // start and stop bits
376 Uart.output[Uart.byteCnt] = (Uart.shiftReg >> 1) & 0xff;
377 Uart.byteCnt++;
378
379 if(Uart.byteCnt >= Uart.byteCntMax) {
380 // Buffer overflowed, give up
381 LED_A_OFF();
382 Uart.state = STATE_UNSYNCD;
383 } else {
384 // so get the next byte now
385 Uart.posCnt = 0;
386 Uart.state = STATE_AWAITING_START_BIT;
387 }
388 } else if (Uart.shiftReg == 0x000) {
389 // this is an EOF byte
390 LED_A_OFF(); // Finished receiving
391 Uart.state = STATE_UNSYNCD;
392 if (Uart.byteCnt != 0) {
393 return TRUE;
394 }
395 } else {
396 // this is an error
397 LED_A_OFF();
398 Uart.state = STATE_UNSYNCD;
399 }
400 }
401 break;
402
403 default:
404 LED_A_OFF();
405 Uart.state = STATE_UNSYNCD;
406 break;
407 }
408
409 return FALSE;
410 }
411
412 //-----------------------------------------------------------------------------
413 // Receive a command (from the reader to us, where we are the simulated tag),
414 // and store it in the given buffer, up to the given maximum length. Keeps
415 // spinning, waiting for a well-framed command, until either we get one
416 // (returns TRUE) or someone presses the pushbutton on the board (FALSE).
417 //
418 // Assume that we're called with the SSC (to the FPGA) and ADC path set
419 // correctly.
420 //-----------------------------------------------------------------------------
421 static int GetIso14443bCommandFromReader(uint8_t *received, uint16_t *len) {
422 // Set FPGA mode to "simulated ISO 14443B tag", no modulation (listen
423 // only, since we are receiving, not transmitting).
424 // Signal field is off with the appropriate LED
425 LED_D_OFF();
426 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION);
427
428 StartCountSspClk();
429
430 volatile uint8_t b;
431
432 // clear receiving shift register and holding register
433 // What does this loop do? Is it TR1?
434 for(uint8_t c = 0; c < 10;) {
435 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
436 AT91C_BASE_SSC->SSC_THR = 0xFF;
437 ++c;
438 }
439 }
440
441 // Now run a `software UART' on the stream of incoming samples.
442 UartInit(received);
443
444 b = 0;
445 uint8_t mask;
446 while( !BUTTON_PRESS() ) {
447 WDT_HIT();
448
449 if ( AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY ) {
450 b = (uint8_t) AT91C_BASE_SSC->SSC_RHR;
451 for ( mask = 0x80; mask != 0; mask >>= 1) {
452 if ( Handle14443bReaderUartBit(b & mask)) {
453 *len = Uart.byteCnt;
454 return TRUE;
455 }
456 }
457 }
458 }
459 return FALSE;
460 }
461
462 void ClearFpgaShiftingRegisters(void){
463
464 volatile uint8_t b;
465
466 // clear receiving shift register and holding register
467 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
468
469 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
470
471 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
472
473 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
474
475
476 // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
477 for (uint8_t j = 0; j < 5; j++) { // allow timeout - better late than never
478 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
479 if (AT91C_BASE_SSC->SSC_RHR) break;
480 }
481
482 // Clear TXRDY:
483 //AT91C_BASE_SSC->SSC_THR = 0xFF;
484 }
485
486 void WaitForFpgaDelayQueueIsEmpty( uint16_t delay ){
487 // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
488 uint8_t fpga_queued_bits = delay >> 3; // twich /8 ?? >>3,
489 for (uint8_t i = 0; i <= fpga_queued_bits/8 + 1; ) {
490 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
491 AT91C_BASE_SSC->SSC_THR = 0xFF;
492 i++;
493 }
494 }
495 }
496
497 static void TransmitFor14443b_AsTag( uint8_t *response, uint16_t len) {
498
499 volatile uint32_t b;
500
501 // Signal field is off with the appropriate LED
502 LED_D_OFF();
503 //uint16_t fpgasendQueueDelay = 0;
504
505 // Modulate BPSK
506 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_BPSK);
507 SpinDelay(40);
508
509 ClearFpgaShiftingRegisters();
510
511 FpgaSetupSsc();
512
513 // Transmit the response.
514 for(uint16_t i = 0; i < len;) {
515 if(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
516 AT91C_BASE_SSC->SSC_THR = response[++i];
517 }
518 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
519 b = AT91C_BASE_SSC->SSC_RHR;
520 (void)b;
521 }
522 }
523
524 //WaitForFpgaDelayQueueIsEmpty(fpgasendQueueDelay);
525 AT91C_BASE_SSC->SSC_THR = 0xFF;
526 }
527 //-----------------------------------------------------------------------------
528 // Main loop of simulated tag: receive commands from reader, decide what
529 // response to send, and send it.
530 //-----------------------------------------------------------------------------
531 void SimulateIso14443bTag(uint32_t pupi) {
532
533 ///////////// setup device.
534 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
535
536 // allocate command receive buffer
537 BigBuf_free();
538 BigBuf_Clear_ext(false);
539 clear_trace(); //sim
540 set_tracing(TRUE);
541
542 // connect Demodulated Signal to ADC:
543 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
544
545 // Set up the synchronous serial port
546 FpgaSetupSsc();
547 /////////////
548
549 uint16_t len, cmdsReceived = 0;
550 int cardSTATE = SIM_NOFIELD;
551 int vHf = 0; // in mV
552 // uint32_t time_0 = 0;
553 // uint32_t t2r_time = 0;
554 // uint32_t r2t_time = 0;
555 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
556
557 // the only commands we understand is WUPB, AFI=0, Select All, N=1:
558 // static const uint8_t cmdWUPB[] = { ISO14443B_REQB, 0x00, 0x08, 0x39, 0x73 }; // WUPB
559 // ... and REQB, AFI=0, Normal Request, N=1:
560 // static const uint8_t cmdREQB[] = { ISO14443B_REQB, 0x00, 0x00, 0x71, 0xFF }; // REQB
561 // ... and ATTRIB
562 // static const uint8_t cmdATTRIB[] = { ISO14443B_ATTRIB, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; // ATTRIB
563
564 // ... if not PUPI/UID is supplied we always respond with ATQB, PUPI = 820de174, Application Data = 0x20381922,
565 // supports only 106kBit/s in both directions, max frame size = 32Bytes,
566 // supports ISO14443-4, FWI=8 (77ms), NAD supported, CID not supported:
567 uint8_t respATQB[] = { 0x50, 0x82, 0x0d, 0xe1, 0x74, 0x20, 0x38, 0x19,
568 0x22, 0x00, 0x21, 0x85, 0x5e, 0xd7 };
569
570 // response to HLTB and ATTRIB
571 static const uint8_t respOK[] = {0x00, 0x78, 0xF0};
572
573 // ...PUPI/UID supplied from user. Adjust ATQB response accordingly
574 if ( pupi > 0 ) {
575 uint8_t len = sizeof(respATQB);
576 num_to_bytes(pupi, 4, respATQB+1);
577 ComputeCrc14443(CRC_14443_B, respATQB, 12, &respATQB[len-2], &respATQB[len-1]);
578 }
579
580 // prepare "ATQB" tag answer (encoded):
581 CodeIso14443bAsTag(respATQB, sizeof(respATQB));
582 uint8_t *encodedATQB = BigBuf_malloc(ToSendMax);
583 uint16_t encodedATQBLen = ToSendMax;
584 memcpy(encodedATQB, ToSend, ToSendMax);
585
586
587 // prepare "OK" tag answer (encoded):
588 CodeIso14443bAsTag(respOK, sizeof(respOK));
589 uint8_t *encodedOK = BigBuf_malloc(ToSendMax);
590 uint16_t encodedOKLen = ToSendMax;
591 memcpy(encodedOK, ToSend, ToSendMax);
592
593 // Simulation loop
594 while (!BUTTON_PRESS() && !usb_poll_validate_length()) {
595 WDT_HIT();
596
597 // find reader field
598 if (cardSTATE == SIM_NOFIELD) {
599 vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
600 if ( vHf > MF_MINFIELDV ) {
601 cardSTATE = SIM_IDLE;
602 LED_A_ON();
603 }
604 }
605 if (cardSTATE == SIM_NOFIELD) continue;
606
607 // Get reader command
608 if (!GetIso14443bCommandFromReader(receivedCmd, &len)) {
609 Dbprintf("button pressed, received %d commands", cmdsReceived);
610 break;
611 }
612
613 // ISO14443-B protocol states:
614 // REQ or WUP request in ANY state
615 // WUP in HALTED state
616 if (len == 5 ) {
617 if ( (receivedCmd[0] == ISO14443B_REQB && (receivedCmd[2] & 0x8)== 0x8 && cardSTATE == SIM_HALTED) ||
618 receivedCmd[0] == ISO14443B_REQB ){
619 LogTrace(receivedCmd, len, 0, 0, NULL, TRUE);
620 cardSTATE = SIM_SELECTING;
621 }
622 }
623
624 /*
625 * How should this flow go?
626 * REQB or WUPB
627 * send response ( waiting for Attrib)
628 * ATTRIB
629 * send response ( waiting for commands 7816)
630 * HALT
631 send halt response ( waiting for wupb )
632 */
633
634 switch (cardSTATE) {
635 case SIM_NOFIELD:
636 case SIM_HALTED:
637 case SIM_IDLE: {
638 LogTrace(receivedCmd, len, 0, 0, NULL, TRUE);
639 break;
640 }
641 case SIM_SELECTING: {
642 TransmitFor14443b_AsTag( encodedATQB, encodedATQBLen );
643 LogTrace(respATQB, sizeof(respATQB), 0, 0, NULL, FALSE);
644 cardSTATE = SIM_WORK;
645 break;
646 }
647 case SIM_HALTING: {
648 TransmitFor14443b_AsTag( encodedOK, encodedOKLen );
649 LogTrace(respOK, sizeof(respOK), 0, 0, NULL, FALSE);
650 cardSTATE = SIM_HALTED;
651 break;
652 }
653 case SIM_ACKNOWLEDGE: {
654 TransmitFor14443b_AsTag( encodedOK, encodedOKLen );
655 LogTrace(respOK, sizeof(respOK), 0, 0, NULL, FALSE);
656 cardSTATE = SIM_IDLE;
657 break;
658 }
659 case SIM_WORK: {
660 if ( len == 7 && receivedCmd[0] == ISO14443B_HALT ) {
661 cardSTATE = SIM_HALTED;
662 } else if ( len == 11 && receivedCmd[0] == ISO14443B_ATTRIB ) {
663 cardSTATE = SIM_ACKNOWLEDGE;
664 } else {
665 // Todo:
666 // - SLOT MARKER
667 // - ISO7816
668 // - emulate with a memory dump
669 Dbprintf("new cmd from reader: len=%d, cmdsRecvd=%d", len, cmdsReceived);
670
671 // CRC Check
672 uint8_t b1, b2;
673 if (len >= 3){ // if crc exists
674 ComputeCrc14443(CRC_14443_B, receivedCmd, len-2, &b1, &b2);
675 if(b1 != receivedCmd[len-2] || b2 != receivedCmd[len-1])
676 DbpString("+++CRC fail");
677 else
678 DbpString("CRC passes");
679 }
680 cardSTATE = SIM_IDLE;
681 }
682 break;
683 }
684 default: break;
685 }
686
687 ++cmdsReceived;
688 // iceman, could add a switch to turn this on/off (if off, no logging?)
689 if(cmdsReceived > 1000) {
690 DbpString("14B Simulate, 1000 commands later...");
691 break;
692 }
693 }
694 if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen());
695 switch_off(); //simulate
696 }
697
698 //=============================================================================
699 // An ISO 14443 Type B reader. We take layer two commands, code them
700 // appropriately, and then send them to the tag. We then listen for the
701 // tag's response, which we leave in the buffer to be demodulated on the
702 // PC side.
703 //=============================================================================
704
705 /*
706 * Handles reception of a bit from the tag
707 *
708 * This function is called 2 times per bit (every 4 subcarrier cycles).
709 * Subcarrier frequency fs is 848kHz, 1/fs = 1,18us, i.e. function is called every 4,72us
710 *
711 * LED handling:
712 * LED C -> ON once we have received the SOF and are expecting the rest.
713 * LED C -> OFF once we have received EOF or are unsynced
714 *
715 * Returns: true if we received a EOF
716 * false if we are still waiting for some more
717 *
718 */
719 // iceman, this threshold value, what makes 8 a good amplituted for this IQ values?
720 #ifndef SUBCARRIER_DETECT_THRESHOLD
721 # define SUBCARRIER_DETECT_THRESHOLD 6
722 #endif
723
724 static RAMFUNC int Handle14443bTagSamplesDemod(int ci, int cq) {
725 int v = 0, myI = 0, myQ = 0;
726 // The soft decision on the bit uses an estimate of just the
727 // quadrant of the reference angle, not the exact angle.
728 #define MAKE_SOFT_DECISION() { \
729 if(Demod.sumI > 0) { \
730 v = ci; \
731 } else { \
732 v = -ci; \
733 } \
734 if(Demod.sumQ > 0) { \
735 v += cq; \
736 } else { \
737 v -= cq; \
738 } \
739 }
740
741 // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by abs(ci) + abs(cq)
742 // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq)))
743 #define CHECK_FOR_SUBCARRIER_old() { \
744 if(ci < 0) { \
745 if(cq < 0) { /* ci < 0, cq < 0 */ \
746 if (cq < ci) { \
747 v = -cq - (ci >> 1); \
748 } else { \
749 v = -ci - (cq >> 1); \
750 } \
751 } else { /* ci < 0, cq >= 0 */ \
752 if (cq < -ci) { \
753 v = -ci + (cq >> 1); \
754 } else { \
755 v = cq - (ci >> 1); \
756 } \
757 } \
758 } else { \
759 if(cq < 0) { /* ci >= 0, cq < 0 */ \
760 if (-cq < ci) { \
761 v = ci - (cq >> 1); \
762 } else { \
763 v = -cq + (ci >> 1); \
764 } \
765 } else { /* ci >= 0, cq >= 0 */ \
766 if (cq < ci) { \
767 v = ci + (cq >> 1); \
768 } else { \
769 v = cq + (ci >> 1); \
770 } \
771 } \
772 } \
773 }
774
775 //note: couldn't we just use MAX(ABS(ci),ABS(cq)) + (MIN(ABS(ci),ABS(cq))/2) from common.h - marshmellow
776 #define CHECK_FOR_SUBCARRIER() { \
777 myI = ABS(ci); \
778 myQ = ABS(cq); \
779 v = MAX(myI, myQ) + (MIN(myI, myQ) >> 1); \
780 }
781
782 switch(Demod.state) {
783 case DEMOD_UNSYNCD:
784
785 CHECK_FOR_SUBCARRIER();
786
787 // subcarrier detected
788 if(v > SUBCARRIER_DETECT_THRESHOLD) {
789 Demod.state = DEMOD_PHASE_REF_TRAINING;
790 Demod.sumI = ci;
791 Demod.sumQ = cq;
792 Demod.posCount = 1;
793 }
794 break;
795
796 case DEMOD_PHASE_REF_TRAINING:
797 if(Demod.posCount < 8) {
798
799 CHECK_FOR_SUBCARRIER();
800
801 if (v > SUBCARRIER_DETECT_THRESHOLD) {
802 // set the reference phase (will code a logic '1') by averaging over 32 1/fs.
803 // note: synchronization time > 80 1/fs
804 Demod.sumI += ci;
805 Demod.sumQ += cq;
806 ++Demod.posCount;
807 } else {
808 // subcarrier lost
809 Demod.state = DEMOD_UNSYNCD;
810 }
811 } else {
812 Demod.state = DEMOD_AWAITING_FALLING_EDGE_OF_SOF;
813 }
814 break;
815
816 case DEMOD_AWAITING_FALLING_EDGE_OF_SOF:
817
818 MAKE_SOFT_DECISION();
819
820 if(v < 0) { // logic '0' detected
821 Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF;
822 Demod.posCount = 0; // start of SOF sequence
823 } else {
824 // maximum length of TR1 = 200 1/fs
825 if(Demod.posCount > 26*2) Demod.state = DEMOD_UNSYNCD;
826 }
827 ++Demod.posCount;
828 break;
829
830 case DEMOD_GOT_FALLING_EDGE_OF_SOF:
831 ++Demod.posCount;
832
833 MAKE_SOFT_DECISION();
834
835 if(v > 0) {
836 // low phase of SOF too short (< 9 etu). Note: spec is >= 10, but FPGA tends to "smear" edges
837 if(Demod.posCount < 8*2) {
838 Demod.state = DEMOD_UNSYNCD;
839 } else {
840 LED_C_ON(); // Got SOF
841 Demod.startTime = GetCountSspClk();
842 Demod.state = DEMOD_AWAITING_START_BIT;
843 Demod.posCount = 0;
844 Demod.len = 0;
845 }
846 } else {
847 // low phase of SOF too long (> 12 etu)
848 if (Demod.posCount > 14*2) {
849 Demod.state = DEMOD_UNSYNCD;
850 LED_C_OFF();
851 }
852 }
853 break;
854
855 case DEMOD_AWAITING_START_BIT:
856 ++Demod.posCount;
857
858 MAKE_SOFT_DECISION();
859
860 if (v > 0) {
861 if(Demod.posCount > 2*2) { // max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs
862 Demod.state = DEMOD_UNSYNCD;
863 LED_C_OFF();
864 }
865 } else { // start bit detected
866 Demod.bitCount = 0;
867 Demod.posCount = 1; // this was the first half
868 Demod.thisBit = v;
869 Demod.shiftReg = 0;
870 Demod.state = DEMOD_RECEIVING_DATA;
871 }
872 break;
873
874 case DEMOD_RECEIVING_DATA:
875
876 MAKE_SOFT_DECISION();
877
878 if (Demod.posCount == 0) {
879 // first half of bit
880 Demod.thisBit = v;
881 Demod.posCount = 1;
882 } else {
883 // second half of bit
884 Demod.thisBit += v;
885 Demod.shiftReg >>= 1;
886
887 // logic '1'
888 if (Demod.thisBit > 0) Demod.shiftReg |= 0x200;
889
890 ++Demod.bitCount;
891
892 // 1 start 8 data 1 stop = 10
893 if (Demod.bitCount == 10) {
894
895 uint16_t s = Demod.shiftReg;
896
897 // stop bit == '1', start bit == '0'
898 if((s & 0x200) && !(s & 0x001)) {
899 uint8_t b = (s >> 1);
900 Demod.output[Demod.len] = b;
901 ++Demod.len;
902 Demod.state = DEMOD_AWAITING_START_BIT;
903 } else {
904 Demod.state = DEMOD_UNSYNCD;
905 Demod.endTime = GetCountSspClk();
906 LED_C_OFF();
907
908 // This is EOF (start, stop and all data bits == '0'
909 if(s == 0) return TRUE;
910 }
911 }
912 Demod.posCount = 0;
913 }
914 break;
915
916 default:
917 Demod.state = DEMOD_UNSYNCD;
918 LED_C_OFF();
919 break;
920 }
921 return FALSE;
922 }
923
924
925 /*
926 * Demodulate the samples we received from the tag, also log to tracebuffer
927 * quiet: set to 'TRUE' to disable debug output
928 */
929 static void GetTagSamplesFor14443bDemod() {
930 bool gotFrame = FALSE, finished = FALSE;
931 int lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
932 int ci = 0, cq = 0, samples = 0;
933 uint32_t time_0 = 0, time_stop = 0;
934
935 BigBuf_free();
936
937 // Set up the demodulator for tag -> reader responses.
938 DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
939
940 // The DMA buffer, used to stream samples from the FPGA
941 int8_t *dmaBuf = (int8_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE);
942 int8_t *upTo = dmaBuf;
943
944 // Setup and start DMA.
945 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE) ){
946 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
947 return;
948 }
949
950 // And put the FPGA in the appropriate mode
951 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
952
953 // get current clock
954 time_0 = GetCountSspClk();
955
956 // rx counter - dma counter? (how much?) & (mod) mask > 2. (since 2bytes at the time is read)
957 while ( !finished ) {
958
959 LED_A_INV();
960 WDT_HIT();
961
962 // LSB is a fpga signal bit.
963 ci = upTo[0] >> 1;
964 cq = upTo[1] >> 1;
965 upTo += 2;
966 samples += 2;
967
968 lastRxCounter -= 2;
969
970 // restart DMA buffer to receive again.
971 if(upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) {
972 upTo = dmaBuf;
973 lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
974 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo;
975 AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE;
976 }
977
978 // https://github.com/Proxmark/proxmark3/issues/103
979 //gotFrame = Handle14443bTagSamplesDemod(ci & 0xfe, cq & 0xfe);
980 gotFrame = Handle14443bTagSamplesDemod(ci, cq);
981 time_stop = GetCountSspClk() - time_0;
982
983 finished = (time_stop > iso14b_timeout || gotFrame);
984 }
985
986 FpgaDisableSscDma();
987
988 if (MF_DBGLEVEL >= 3) {
989 Dbprintf("time_stop = %u PDC_RCR = %u", time_stop, AT91C_BASE_PDC_SSC->PDC_RCR);
990 Dbprintf("#Samples = %d, Demod.state = %d, Demod.len = %u",
991 samples,
992 Demod.state,
993 Demod.len
994 );
995 }
996
997 if (MF_DBGLEVEL == 4)
998 Dbhexdump(ISO14443B_DMA_BUFFER_SIZE, (uint8_t *)dmaBuf, FALSE);
999
1000 if ( Demod.len > 0 )
1001 LogTrace(Demod.output, Demod.len, Demod.startTime, Demod.endTime, NULL, FALSE);
1002 }
1003
1004
1005 //-----------------------------------------------------------------------------
1006 // Transmit the command (to the tag) that was placed in ToSend[].
1007 //-----------------------------------------------------------------------------
1008 static void TransmitFor14443b_AsReader(void) {
1009
1010 // we could been in following mode:
1011 // FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ
1012 // if its second call or more
1013
1014 // while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1015 // AT91C_BASE_SSC->SSC_THR = 0XFF;
1016 // }
1017
1018 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
1019 SpinDelay(40);
1020
1021 int c;
1022 volatile uint32_t b;
1023
1024 // What does this loop do? Is it TR1?
1025 // 0xFF = 8 bits of 1. 1 bit == 1Etu,..
1026 // loop 10 * 8 = 80 ETU of delay, with a non modulated signal. why?
1027 // 80*9 = 720us.
1028 for(c = 0; c < 50;) {
1029 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1030 AT91C_BASE_SSC->SSC_THR = 0xFF;
1031 ++c;
1032 }
1033 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1034 b = AT91C_BASE_SSC->SSC_RHR;
1035 (void)b;
1036 }
1037 }
1038
1039 // Send frame loop
1040 for(c = 0; c < ToSendMax;) {
1041 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1042 AT91C_BASE_SSC->SSC_THR = ToSend[c++];
1043 }
1044 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1045 b = AT91C_BASE_SSC->SSC_RHR;
1046 (void)b;
1047 }
1048 }
1049 //WaitForFpgaDelayQueueIsEmpty(delay);
1050 // We should wait here for the FPGA to send all bits.
1051 WDT_HIT();
1052 }
1053
1054 //-----------------------------------------------------------------------------
1055 // Code a layer 2 command (string of octets, including CRC) into ToSend[],
1056 // so that it is ready to transmit to the tag using TransmitFor14443b().
1057 //-----------------------------------------------------------------------------
1058 static void CodeIso14443bAsReader(const uint8_t *cmd, int len)
1059 {
1060 /*
1061 * Reader data transmission:
1062 * - no modulation ONES
1063 * - SOF
1064 * - Command, data and CRC_B
1065 * - EOF
1066 * - no modulation ONES
1067 *
1068 * 1 ETU == 1 BIT!
1069 * TR0 - 8 ETUS minimum.
1070 *
1071 * QUESTION: how long is a 1 or 0 in pulses in the xcorr_848 mode?
1072 * 1 "stuffbit" = 1ETU (9us)
1073 */
1074 int i;
1075 uint8_t b;
1076
1077 ToSendReset();
1078
1079 // Send SOF
1080 // 10-11 ETUs of ZERO
1081 for(i = 0; i < 10; ++i) ToSendStuffBit(0);
1082
1083 // 2-3 ETUs of ONE
1084 ToSendStuffBit(1);
1085 ToSendStuffBit(1);
1086 ToSendStuffBit(1);
1087
1088 // Sending cmd, LSB
1089 // from here we add BITS
1090 for(i = 0; i < len; ++i) {
1091 // Start bit
1092 ToSendStuffBit(0);
1093 // Data bits
1094 b = cmd[i];
1095 if ( b & 1 ) ToSendStuffBit(1); else ToSendStuffBit(0);
1096 if ( (b>>1) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1097 if ( (b>>2) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1098 if ( (b>>3) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1099 if ( (b>>4) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1100 if ( (b>>5) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1101 if ( (b>>6) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1102 if ( (b>>7) & 1) ToSendStuffBit(1); else ToSendStuffBit(0);
1103 // Stop bit
1104 ToSendStuffBit(1);
1105 // EGT extra guard time
1106 // For PCD it ranges 0-57us (1etu = 9us)
1107 ToSendStuffBit(1);
1108 ToSendStuffBit(1);
1109 ToSendStuffBit(1);
1110 }
1111
1112 // Send EOF
1113 // 10-11 ETUs of ZERO
1114 for(i = 0; i < 10; ++i) ToSendStuffBit(0);
1115
1116 // Transition time. TR0 - guard time
1117 // 8ETUS minum?
1118 // Per specification, Subcarrier must be stopped no later than 2 ETUs after EOF.
1119 // I'm guessing this is for the FPGA to be able to send all bits before we switch to listening mode
1120 for(i = 0; i < 32 ; ++i) ToSendStuffBit(1);
1121
1122 // TR1 - Synchronization time
1123 // Convert from last character reference to length
1124 ++ToSendMax;
1125 }
1126
1127
1128 /**
1129 Convenience function to encode, transmit and trace iso 14443b comms
1130 **/
1131 static void CodeAndTransmit14443bAsReader(const uint8_t *cmd, int len) {
1132
1133 CodeIso14443bAsReader(cmd, len);
1134
1135 uint32_t time_start = GetCountSspClk();
1136
1137 TransmitFor14443b_AsReader();
1138
1139 if(trigger) LED_A_ON();
1140
1141 LogTrace(cmd, len, time_start, GetCountSspClk()-time_start, NULL, TRUE);
1142 }
1143
1144 /* Sends an APDU to the tag
1145 * TODO: check CRC and preamble
1146 */
1147 uint8_t iso14443b_apdu(uint8_t const *message, size_t message_length, uint8_t *response)
1148 {
1149 uint8_t crc[2] = {0x00, 0x00};
1150 uint8_t message_frame[message_length + 4];
1151 // PCB
1152 message_frame[0] = 0x0A | pcb_blocknum;
1153 pcb_blocknum ^= 1;
1154 // CID
1155 message_frame[1] = 0;
1156 // INF
1157 memcpy(message_frame + 2, message, message_length);
1158 // EDC (CRC)
1159 ComputeCrc14443(CRC_14443_B, message_frame, message_length + 2, &message_frame[message_length + 2], &message_frame[message_length + 3]);
1160 // send
1161 CodeAndTransmit14443bAsReader(message_frame, message_length + 4); //no
1162 // get response
1163 GetTagSamplesFor14443bDemod(); //no
1164 if(Demod.len < 3)
1165 return 0;
1166
1167 // VALIDATE CRC
1168 ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
1169 if ( crc[0] != Demod.output[Demod.len-2] || crc[1] != Demod.output[Demod.len-1] )
1170 return 0;
1171
1172 // copy response contents
1173 if(response != NULL)
1174 memcpy(response, Demod.output, Demod.len);
1175
1176 return Demod.len;
1177 }
1178
1179 /**
1180 * SRx Initialise.
1181 */
1182 uint8_t iso14443b_select_srx_card(iso14b_card_select_t *card )
1183 {
1184 // INITIATE command: wake up the tag using the INITIATE
1185 static const uint8_t init_srx[] = { ISO14443B_INITIATE, 0x00, 0x97, 0x5b };
1186 // SELECT command (with space for CRC)
1187 uint8_t select_srx[] = { ISO14443B_SELECT, 0x00, 0x00, 0x00};
1188 // temp to calc crc.
1189 uint8_t crc[2] = {0x00, 0x00};
1190
1191 CodeAndTransmit14443bAsReader(init_srx, sizeof(init_srx));
1192 GetTagSamplesFor14443bDemod(); //no
1193
1194 if (Demod.len == 0) return 2;
1195
1196 // Randomly generated Chip ID
1197 if (card) card->chipid = Demod.output[0];
1198
1199 select_srx[1] = Demod.output[0];
1200
1201 ComputeCrc14443(CRC_14443_B, select_srx, 2, &select_srx[2], &select_srx[3]);
1202 CodeAndTransmit14443bAsReader(select_srx, sizeof(select_srx));
1203 GetTagSamplesFor14443bDemod(); //no
1204
1205 if (Demod.len != 3) return 2;
1206
1207 // Check the CRC of the answer:
1208 ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2 , &crc[0], &crc[1]);
1209 if(crc[0] != Demod.output[1] || crc[1] != Demod.output[2]) return 3;
1210
1211 // Check response from the tag: should be the same UID as the command we just sent:
1212 if (select_srx[1] != Demod.output[0]) return 1;
1213
1214 // First get the tag's UID:
1215 select_srx[0] = ISO14443B_GET_UID;
1216
1217 ComputeCrc14443(CRC_14443_B, select_srx, 1 , &select_srx[1], &select_srx[2]);
1218 CodeAndTransmit14443bAsReader(select_srx, 3); // Only first three bytes for this one
1219 GetTagSamplesFor14443bDemod(); //no
1220
1221 if (Demod.len != 10) return 2;
1222
1223 // The check the CRC of the answer
1224 ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
1225 if(crc[0] != Demod.output[8] || crc[1] != Demod.output[9]) return 3;
1226
1227 if (card) {
1228 card->uidlen = 8;
1229 memcpy(card->uid, Demod.output, 8);
1230 }
1231
1232 return 0;
1233 }
1234 /* Perform the ISO 14443 B Card Selection procedure
1235 * Currently does NOT do any collision handling.
1236 * It expects 0-1 cards in the device's range.
1237 * TODO: Support multiple cards (perform anticollision)
1238 * TODO: Verify CRC checksums
1239 */
1240 uint8_t iso14443b_select_card(iso14b_card_select_t *card )
1241 {
1242 // WUPB command (including CRC)
1243 // Note: WUPB wakes up all tags, REQB doesn't wake up tags in HALT state
1244 static const uint8_t wupb[] = { ISO14443B_REQB, 0x00, 0x08, 0x39, 0x73 };
1245 // ATTRIB command (with space for CRC)
1246 uint8_t attrib[] = { ISO14443B_ATTRIB, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00};
1247
1248 // temp to calc crc.
1249 uint8_t crc[2] = {0x00, 0x00};
1250
1251 // first, wake up the tag
1252 CodeAndTransmit14443bAsReader(wupb, sizeof(wupb));
1253 GetTagSamplesFor14443bDemod(); //select_card
1254
1255 // ATQB too short?
1256 if (Demod.len < 14) return 2;
1257
1258 // VALIDATE CRC
1259 ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
1260 if ( crc[0] != Demod.output[12] || crc[1] != Demod.output[13] )
1261 return 3;
1262
1263 if (card) {
1264 card->uidlen = 4;
1265 memcpy(card->uid, Demod.output+1, 4);
1266 memcpy(card->atqb, Demod.output+5, 7);
1267 }
1268
1269 // copy the PUPI to ATTRIB ( PUPI == UID )
1270 memcpy(attrib + 1, Demod.output + 1, 4);
1271
1272 // copy the protocol info from ATQB (Protocol Info -> Protocol_Type) into ATTRIB (Param 3)
1273 attrib[7] = Demod.output[10] & 0x0F;
1274 ComputeCrc14443(CRC_14443_B, attrib, 9, attrib + 9, attrib + 10);
1275
1276 CodeAndTransmit14443bAsReader(attrib, sizeof(attrib));
1277 GetTagSamplesFor14443bDemod();//select_card
1278
1279 // Answer to ATTRIB too short?
1280 if(Demod.len < 3) return 2;
1281
1282 // VALIDATE CRC
1283 ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
1284 if ( crc[0] != Demod.output[1] || crc[1] != Demod.output[2] )
1285 return 3;
1286
1287 // CID
1288 if (card) {
1289 card->cid = Demod.output[0];
1290 uint8_t fwt = card->atqb[6] >> 4;
1291 if ( fwt < 16 ){
1292 uint32_t fwt_time = (302 << fwt);
1293 iso14b_set_timeout( fwt_time);
1294 }
1295 }
1296 // reset PCB block number
1297 pcb_blocknum = 0;
1298 return 0;
1299 }
1300
1301 // Set up ISO 14443 Type B communication (similar to iso14443a_setup)
1302 // field is setup for "Sending as Reader"
1303 void iso14443b_setup() {
1304 if (MF_DBGLEVEL > 3) Dbprintf("iso1443b_setup Enter");
1305 LEDsoff();
1306 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1307 //BigBuf_free();
1308 //BigBuf_Clear_ext(false);
1309
1310 // Initialize Demod and Uart structs
1311 DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
1312 UartInit(BigBuf_malloc(MAX_FRAME_SIZE));
1313
1314 // connect Demodulated Signal to ADC:
1315 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1316
1317 // Set up the synchronous serial port
1318 FpgaSetupSsc();
1319
1320 // Signal field is on with the appropriate LED
1321 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
1322 SpinDelay(100);
1323
1324 // Start the timer
1325 StartCountSspClk();
1326
1327 LED_D_ON();
1328 if (MF_DBGLEVEL > 3) Dbprintf("iso1443b_setup Exit");
1329 }
1330
1331 //-----------------------------------------------------------------------------
1332 // Read a SRI512 ISO 14443B tag.
1333 //
1334 // SRI512 tags are just simple memory tags, here we're looking at making a dump
1335 // of the contents of the memory. No anticollision algorithm is done, we assume
1336 // we have a single tag in the field.
1337 //
1338 // I tried to be systematic and check every answer of the tag, every CRC, etc...
1339 //-----------------------------------------------------------------------------
1340 void ReadSTMemoryIso14443b(uint8_t numofblocks)
1341 {
1342 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1343
1344 // Make sure that we start from off, since the tags are stateful;
1345 // confusing things will happen if we don't reset them between reads.
1346 switch_off(); // before ReadStMemory
1347
1348 set_tracing(TRUE);
1349
1350 uint8_t i = 0x00;
1351
1352 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1353 FpgaSetupSsc();
1354
1355 // Now give it time to spin up.
1356 // Signal field is on with the appropriate LED
1357 LED_D_ON();
1358 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ);
1359 SpinDelay(20);
1360
1361 // First command: wake up the tag using the INITIATE command
1362 uint8_t cmd1[] = {ISO14443B_INITIATE, 0x00, 0x97, 0x5b};
1363 CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1)); //no
1364 GetTagSamplesFor14443bDemod(); // no
1365
1366 if (Demod.len == 0) {
1367 DbpString("No response from tag");
1368 set_tracing(FALSE);
1369 return;
1370 } else {
1371 Dbprintf("Randomly generated Chip ID (+ 2 byte CRC): %02x %02x %02x",
1372 Demod.output[0], Demod.output[1], Demod.output[2]);
1373 }
1374
1375 // There is a response, SELECT the uid
1376 DbpString("Now SELECT tag:");
1377 cmd1[0] = ISO14443B_SELECT; // 0x0E is SELECT
1378 cmd1[1] = Demod.output[0];
1379 ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
1380 CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1)); //no
1381 GetTagSamplesFor14443bDemod(); //no
1382 if (Demod.len != 3) {
1383 Dbprintf("Expected 3 bytes from tag, got %d", Demod.len);
1384 set_tracing(FALSE);
1385 return;
1386 }
1387 // Check the CRC of the answer:
1388 ComputeCrc14443(CRC_14443_B, Demod.output, 1 , &cmd1[2], &cmd1[3]);
1389 if(cmd1[2] != Demod.output[1] || cmd1[3] != Demod.output[2]) {
1390 DbpString("CRC Error reading select response.");
1391 set_tracing(FALSE);
1392 return;
1393 }
1394 // Check response from the tag: should be the same UID as the command we just sent:
1395 if (cmd1[1] != Demod.output[0]) {
1396 Dbprintf("Bad response to SELECT from Tag, aborting: %02x %02x", cmd1[1], Demod.output[0]);
1397 set_tracing(FALSE);
1398 return;
1399 }
1400
1401 // Tag is now selected,
1402 // First get the tag's UID:
1403 cmd1[0] = ISO14443B_GET_UID;
1404 ComputeCrc14443(CRC_14443_B, cmd1, 1 , &cmd1[1], &cmd1[2]);
1405 CodeAndTransmit14443bAsReader(cmd1, 3); // no -- Only first three bytes for this one
1406 GetTagSamplesFor14443bDemod(); //no
1407 if (Demod.len != 10) {
1408 Dbprintf("Expected 10 bytes from tag, got %d", Demod.len);
1409 set_tracing(FALSE);
1410 return;
1411 }
1412 // The check the CRC of the answer (use cmd1 as temporary variable):
1413 ComputeCrc14443(CRC_14443_B, Demod.output, 8, &cmd1[2], &cmd1[3]);
1414 if(cmd1[2] != Demod.output[8] || cmd1[3] != Demod.output[9]) {
1415 Dbprintf("CRC Error reading block! Expected: %04x got: %04x",
1416 (cmd1[2]<<8)+cmd1[3], (Demod.output[8]<<8)+Demod.output[9]);
1417 // Do not return;, let's go on... (we should retry, maybe ?)
1418 }
1419 Dbprintf("Tag UID (64 bits): %08x %08x",
1420 (Demod.output[7]<<24) + (Demod.output[6]<<16) + (Demod.output[5]<<8) + Demod.output[4],
1421 (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0]);
1422
1423 // Now loop to read all 16 blocks, address from 0 to last block
1424 Dbprintf("Tag memory dump, block 0 to %d", numofblocks);
1425 cmd1[0] = 0x08;
1426 i = 0x00;
1427 ++numofblocks;
1428
1429 for (;;) {
1430 if (i == numofblocks) {
1431 DbpString("System area block (0xff):");
1432 i = 0xff;
1433 }
1434 cmd1[1] = i;
1435 ComputeCrc14443(CRC_14443_B, cmd1, 2, &cmd1[2], &cmd1[3]);
1436 CodeAndTransmit14443bAsReader(cmd1, sizeof(cmd1)); //no
1437 GetTagSamplesFor14443bDemod(); //no
1438
1439 if (Demod.len != 6) { // Check if we got an answer from the tag
1440 DbpString("Expected 6 bytes from tag, got less...");
1441 return;
1442 }
1443 // The check the CRC of the answer (use cmd1 as temporary variable):
1444 ComputeCrc14443(CRC_14443_B, Demod.output, 4, &cmd1[2], &cmd1[3]);
1445 if(cmd1[2] != Demod.output[4] || cmd1[3] != Demod.output[5]) {
1446 Dbprintf("CRC Error reading block! Expected: %04x got: %04x",
1447 (cmd1[2]<<8)+cmd1[3], (Demod.output[4]<<8)+Demod.output[5]);
1448 // Do not return;, let's go on... (we should retry, maybe ?)
1449 }
1450 // Now print out the memory location:
1451 Dbprintf("Address=%02x, Contents=%08x, CRC=%04x", i,
1452 (Demod.output[3]<<24) + (Demod.output[2]<<16) + (Demod.output[1]<<8) + Demod.output[0],
1453 (Demod.output[4]<<8)+Demod.output[5]);
1454
1455 if (i == 0xff) break;
1456 ++i;
1457 }
1458
1459 set_tracing(FALSE);
1460 }
1461
1462
1463 static void iso1444b_setup_snoop(void){
1464 if (MF_DBGLEVEL > 3) Dbprintf("iso1443b_setup_snoop Enter");
1465 LEDsoff();
1466 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1467 BigBuf_free();
1468 BigBuf_Clear_ext(false);
1469 clear_trace();//setup snoop
1470 set_tracing(TRUE);
1471
1472 // Initialize Demod and Uart structs
1473 DemodInit(BigBuf_malloc(MAX_FRAME_SIZE));
1474 UartInit(BigBuf_malloc(MAX_FRAME_SIZE));
1475
1476 if (MF_DBGLEVEL > 1) {
1477 // Print debug information about the buffer sizes
1478 Dbprintf("Snooping buffers initialized:");
1479 Dbprintf(" Trace: %i bytes", BigBuf_max_traceLen());
1480 Dbprintf(" Reader -> tag: %i bytes", MAX_FRAME_SIZE);
1481 Dbprintf(" tag -> Reader: %i bytes", MAX_FRAME_SIZE);
1482 Dbprintf(" DMA: %i bytes", ISO14443B_DMA_BUFFER_SIZE);
1483 }
1484
1485 // connect Demodulated Signal to ADC:
1486 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1487
1488 // Setup for the DMA.
1489 FpgaSetupSsc();
1490
1491 // Set FPGA in the appropriate mode
1492 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | FPGA_HF_READER_RX_XCORR_SNOOP);
1493 SpinDelay(20);
1494
1495 // Start the SSP timer
1496 StartCountSspClk();
1497 if (MF_DBGLEVEL > 3) Dbprintf("iso1443b_setup_snoop Exit");
1498 }
1499
1500 //=============================================================================
1501 // Finally, the `sniffer' combines elements from both the reader and
1502 // simulated tag, to show both sides of the conversation.
1503 //=============================================================================
1504
1505 //-----------------------------------------------------------------------------
1506 // Record the sequence of commands sent by the reader to the tag, with
1507 // triggering so that we start recording at the point that the tag is moved
1508 // near the reader.
1509 //-----------------------------------------------------------------------------
1510 /*
1511 * Memory usage for this function, (within BigBuf)
1512 * Last Received command (reader->tag) - MAX_FRAME_SIZE
1513 * Last Received command (tag->reader) - MAX_FRAME_SIZE
1514 * DMA Buffer - ISO14443B_DMA_BUFFER_SIZE
1515 * Demodulated samples received - all the rest
1516 */
1517 void RAMFUNC SnoopIso14443b(void) {
1518
1519 uint32_t time_0 = 0, time_start = 0, time_stop = 0;
1520
1521 // We won't start recording the frames that we acquire until we trigger;
1522 // a good trigger condition to get started is probably when we see a
1523 // response from the tag.
1524 int triggered = TRUE; // TODO: set and evaluate trigger condition
1525 int ci, cq;
1526 int maxBehindBy = 0;
1527 //int behindBy = 0;
1528 int lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
1529
1530 bool TagIsActive = FALSE;
1531 bool ReaderIsActive = FALSE;
1532
1533 iso1444b_setup_snoop();
1534
1535 // The DMA buffer, used to stream samples from the FPGA
1536 int8_t *dmaBuf = (int8_t*) BigBuf_malloc(ISO14443B_DMA_BUFFER_SIZE);
1537 int8_t *upTo = dmaBuf;
1538
1539 // Setup and start DMA.
1540 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, ISO14443B_DMA_BUFFER_SIZE) ){
1541 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
1542 BigBuf_free();
1543 return;
1544 }
1545
1546 time_0 = GetCountSspClk();
1547
1548 // And now we loop, receiving samples.
1549 for(;;) {
1550
1551 WDT_HIT();
1552
1553 /* iceman: the & (and) should do what?
1554 ISO14443B_DMA_BUFFER_SIZE = 256
1555 Should it be a "mod 255" ?
1556
1557 (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & (ISO14443B_DMA_BUFFER_SIZE-1);
1558
1559 */
1560 int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) & RECEIVE_MASK;
1561
1562 if ( behindBy > maxBehindBy )
1563 maxBehindBy = behindBy;
1564
1565 // this one needs the inner loop from tr
1566 if ( behindBy < 2 ) continue;
1567
1568 ci = upTo[0];
1569 cq = upTo[1];
1570 upTo += 2;
1571
1572 lastRxCounter -= 2;
1573
1574 if (upTo >= dmaBuf + ISO14443B_DMA_BUFFER_SIZE) {
1575 upTo = dmaBuf;
1576 lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
1577 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
1578 AT91C_BASE_PDC_SSC->PDC_RNCR = ISO14443B_DMA_BUFFER_SIZE;
1579 WDT_HIT();
1580
1581 // TODO: understand whether we can increase/decrease as we want or not?
1582 if ( behindBy > ( 9 * ISO14443B_DMA_BUFFER_SIZE/10) ) {
1583 Dbprintf("blew circular buffer! behindBy = %d", behindBy);
1584 break;
1585 }
1586
1587 if(!tracing) {
1588 DbpString("Trace full");
1589 break;
1590 }
1591
1592 if(BUTTON_PRESS()) {
1593 DbpString("cancelled");
1594 break;
1595 }
1596 }
1597
1598 if (!TagIsActive) {
1599
1600 LED_A_ON();
1601
1602 // no need to try decoding reader data if the tag is sending
1603 if (Handle14443bReaderUartBit(ci & 0x01)) {
1604
1605 time_stop = GetCountSspClk() - time_0;
1606
1607 if (triggered)
1608 LogTrace(Uart.output, Uart.byteCnt, time_start, time_stop, NULL, TRUE);
1609
1610 /* And ready to receive another command. */
1611 UartReset();
1612 /* And also reset the demod code, which might have been */
1613 /* false-triggered by the commands from the reader. */
1614 DemodReset();
1615 } else {
1616 time_start = GetCountSspClk() - time_0;
1617 }
1618
1619 if (Handle14443bReaderUartBit(cq & 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 ReaderIsActive = (Uart.state > STATE_GOT_FALLING_EDGE_OF_SOF);
1635 LED_A_OFF();
1636 }
1637
1638 if(!ReaderIsActive) {
1639 // no need to try decoding tag data if the reader is sending - and we cannot afford the time
1640 // is this | 0x01 the error? & 0xfe in https://github.com/Proxmark/proxmark3/issues/103
1641 if(Handle14443bTagSamplesDemod(ci & 0xFE, cq & 0xFE)) {
1642
1643 time_stop = GetCountSspClk() - time_0;
1644
1645 LogTrace(Demod.output, Demod.len, time_start, time_stop, NULL, FALSE);
1646
1647 triggered = TRUE;
1648
1649 // And ready to receive another response.
1650 DemodReset();
1651 } else {
1652 time_start = GetCountSspClk() - time_0;
1653 }
1654 TagIsActive = (Demod.state > DEMOD_GOT_FALLING_EDGE_OF_SOF);
1655 }
1656 }
1657
1658 switch_off(); // Snoop
1659
1660 DbpString("Snoop statistics:");
1661 Dbprintf(" Max behind by: %i", maxBehindBy);
1662 Dbprintf(" Uart State: %x ByteCount: %i ByteCountMax: %i", Uart.state, Uart.byteCnt, Uart.byteCntMax);
1663 Dbprintf(" Trace length: %i", BigBuf_get_traceLen());
1664
1665 // free mem refs.
1666 if ( upTo ) upTo = NULL;
1667
1668 // Uart.byteCntMax should be set with ATQB value..
1669 }
1670
1671 void iso14b_set_trigger(bool enable) {
1672 trigger = enable;
1673 }
1674
1675 /*
1676 * Send raw command to tag ISO14443B
1677 * @Input
1678 * param flags enum ISO14B_COMMAND. (mifare.h)
1679 * len len of buffer data
1680 * data buffer with bytes to send
1681 *
1682 * @Output
1683 * none
1684 *
1685 */
1686 void SendRawCommand14443B_Ex(UsbCommand *c)
1687 {
1688 iso14b_command_t param = c->arg[0];
1689 size_t len = c->arg[1] & 0xffff;
1690 uint8_t *cmd = c->d.asBytes;
1691 uint8_t status = 0;
1692 uint32_t sendlen = sizeof(iso14b_card_select_t);
1693 uint8_t buf[USB_CMD_DATA_SIZE] = {0x00};
1694
1695 if (MF_DBGLEVEL > 3) Dbprintf("14b raw: param, %04x", param );
1696
1697 // turn on trigger (LED_A)
1698 if ((param & ISO14B_REQUEST_TRIGGER) == ISO14B_REQUEST_TRIGGER)
1699 iso14b_set_trigger(TRUE);
1700
1701 if ((param & ISO14B_CONNECT) == ISO14B_CONNECT) {
1702 // Make sure that we start from off, since the tags are stateful;
1703 // confusing things will happen if we don't reset them between reads.
1704 //switch_off(); // before connect in raw
1705 iso14443b_setup();
1706 }
1707
1708 set_tracing(TRUE);
1709
1710 if ((param & ISO14B_SELECT_STD) == ISO14B_SELECT_STD) {
1711 iso14b_card_select_t *card = (iso14b_card_select_t*)buf;
1712 status = iso14443b_select_card(card);
1713 cmd_send(CMD_ACK, status, sendlen, 0, buf, sendlen);
1714 // 0: OK 2: attrib fail, 3:crc fail,
1715 if ( status > 0 ) return;
1716 }
1717
1718 if ((param & ISO14B_SELECT_SR) == ISO14B_SELECT_SR) {
1719 iso14b_card_select_t *card = (iso14b_card_select_t*)buf;
1720 status = iso14443b_select_srx_card(card);
1721 cmd_send(CMD_ACK, status, sendlen, 0, buf, sendlen);
1722 // 0: OK 2: attrib fail, 3:crc fail,
1723 if ( status > 0 ) return;
1724 }
1725
1726 if ((param & ISO14B_APDU) == ISO14B_APDU) {
1727 status = iso14443b_apdu(cmd, len, buf);
1728 cmd_send(CMD_ACK, status, status, 0, buf, status);
1729 }
1730
1731 if ((param & ISO14B_RAW) == ISO14B_RAW) {
1732 if((param & ISO14B_APPEND_CRC) == ISO14B_APPEND_CRC) {
1733 AppendCrc14443b(cmd, len);
1734 len += 2;
1735 }
1736
1737 CodeAndTransmit14443bAsReader(cmd, len); // raw
1738 GetTagSamplesFor14443bDemod(); // raw
1739
1740 sendlen = MIN(Demod.len, USB_CMD_DATA_SIZE);
1741 status = (Demod.len > 0) ? 0 : 1;
1742 cmd_send(CMD_ACK, status, sendlen, 0, Demod.output, sendlen);
1743 }
1744
1745 // turn off trigger (LED_A)
1746 if ((param & ISO14B_REQUEST_TRIGGER) == ISO14B_REQUEST_TRIGGER)
1747 iso14b_set_trigger(FALSE);
1748
1749 // turn off antenna et al
1750 // we don't send a HALT command.
1751 if ((param & ISO14B_DISCONNECT) == ISO14B_DISCONNECT) {
1752 if (MF_DBGLEVEL > 3) Dbprintf("disconnect");
1753 switch_off(); // disconnect raw
1754 } else {
1755 //FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD);
1756 }
1757
1758 }
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