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1 //-----------------------------------------------------------------------------
2 // Merlok - June 2011, 2012
3 // Gerhard de Koning Gans - May 2008
4 // Hagen Fritsch - June 2010
5 //
6 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
7 // at your option, any later version. See the LICENSE.txt file for the text of
8 // the license.
9 //-----------------------------------------------------------------------------
10 // Routines to support ISO 14443 type A.
11 //-----------------------------------------------------------------------------
12
13 #include "proxmark3.h"
14 #include "apps.h"
15 #include "util.h"
16 #include "string.h"
17 #include "cmd.h"
18 #include "iso14443crc.h"
19 #include "iso14443a.h"
20 #include "crapto1.h"
21 #include "mifareutil.h"
22 #include "BigBuf.h"
23 #include "parity.h"
24
25 static uint32_t iso14a_timeout;
26 int rsamples = 0;
27 uint8_t trigger = 0;
28 // the block number for the ISO14443-4 PCB
29 static uint8_t iso14_pcb_blocknum = 0;
30
31 //
32 // ISO14443 timing:
33 //
34 // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
35 #define REQUEST_GUARD_TIME (7000/16 + 1)
36 // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
37 #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
38 // bool LastCommandWasRequest = FALSE;
39
40 //
41 // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
42 //
43 // When the PM acts as reader and is receiving tag data, it takes
44 // 3 ticks delay in the AD converter
45 // 16 ticks until the modulation detector completes and sets curbit
46 // 8 ticks until bit_to_arm is assigned from curbit
47 // 8*16 ticks for the transfer from FPGA to ARM
48 // 4*16 ticks until we measure the time
49 // - 8*16 ticks because we measure the time of the previous transfer
50 #define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
51
52 // When the PM acts as a reader and is sending, it takes
53 // 4*16 ticks until we can write data to the sending hold register
54 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
55 // 8 ticks until the first transfer starts
56 // 8 ticks later the FPGA samples the data
57 // 1 tick to assign mod_sig_coil
58 #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
59
60 // When the PM acts as tag and is receiving it takes
61 // 2 ticks delay in the RF part (for the first falling edge),
62 // 3 ticks for the A/D conversion,
63 // 8 ticks on average until the start of the SSC transfer,
64 // 8 ticks until the SSC samples the first data
65 // 7*16 ticks to complete the transfer from FPGA to ARM
66 // 8 ticks until the next ssp_clk rising edge
67 // 4*16 ticks until we measure the time
68 // - 8*16 ticks because we measure the time of the previous transfer
69 #define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
70
71 // The FPGA will report its internal sending delay in
72 uint16_t FpgaSendQueueDelay;
73 // the 5 first bits are the number of bits buffered in mod_sig_buf
74 // the last three bits are the remaining ticks/2 after the mod_sig_buf shift
75 #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
76
77 // When the PM acts as tag and is sending, it takes
78 // 4*16 ticks until we can write data to the sending hold register
79 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
80 // 8 ticks until the first transfer starts
81 // 8 ticks later the FPGA samples the data
82 // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
83 // + 1 tick to assign mod_sig_coil
84 #define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
85
86 // When the PM acts as sniffer and is receiving tag data, it takes
87 // 3 ticks A/D conversion
88 // 14 ticks to complete the modulation detection
89 // 8 ticks (on average) until the result is stored in to_arm
90 // + the delays in transferring data - which is the same for
91 // sniffing reader and tag data and therefore not relevant
92 #define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
93
94 // When the PM acts as sniffer and is receiving reader data, it takes
95 // 2 ticks delay in analogue RF receiver (for the falling edge of the
96 // start bit, which marks the start of the communication)
97 // 3 ticks A/D conversion
98 // 8 ticks on average until the data is stored in to_arm.
99 // + the delays in transferring data - which is the same for
100 // sniffing reader and tag data and therefore not relevant
101 #define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
102
103 //variables used for timing purposes:
104 //these are in ssp_clk cycles:
105 static uint32_t NextTransferTime;
106 static uint32_t LastTimeProxToAirStart;
107 static uint32_t LastProxToAirDuration;
108
109
110
111 // CARD TO READER - manchester
112 // Sequence D: 11110000 modulation with subcarrier during first half
113 // Sequence E: 00001111 modulation with subcarrier during second half
114 // Sequence F: 00000000 no modulation with subcarrier
115 // READER TO CARD - miller
116 // Sequence X: 00001100 drop after half a period
117 // Sequence Y: 00000000 no drop
118 // Sequence Z: 11000000 drop at start
119 #define SEC_D 0xf0
120 #define SEC_E 0x0f
121 #define SEC_F 0x00
122 #define SEC_X 0x0c
123 #define SEC_Y 0x00
124 #define SEC_Z 0xc0
125
126 void iso14a_set_trigger(bool enable) {
127 trigger = enable;
128 }
129
130
131 void iso14a_set_timeout(uint32_t timeout) {
132 iso14a_timeout = timeout;
133 if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
134 }
135
136
137 void iso14a_set_ATS_timeout(uint8_t *ats) {
138
139 uint8_t tb1;
140 uint8_t fwi;
141 uint32_t fwt;
142
143 if (ats[0] > 1) { // there is a format byte T0
144 if ((ats[1] & 0x20) == 0x20) { // there is an interface byte TB(1)
145 if ((ats[1] & 0x10) == 0x10) { // there is an interface byte TA(1) preceding TB(1)
146 tb1 = ats[3];
147 } else {
148 tb1 = ats[2];
149 }
150 fwi = (tb1 & 0xf0) >> 4; // frame waiting indicator (FWI)
151 fwt = 256 * 16 * (1 << fwi); // frame waiting time (FWT) in 1/fc
152
153 iso14a_set_timeout(fwt/(8*16));
154 }
155 }
156 }
157
158
159 //-----------------------------------------------------------------------------
160 // Generate the parity value for a byte sequence
161 //
162 //-----------------------------------------------------------------------------
163 void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par)
164 {
165 uint16_t paritybit_cnt = 0;
166 uint16_t paritybyte_cnt = 0;
167 uint8_t parityBits = 0;
168
169 for (uint16_t i = 0; i < iLen; i++) {
170 // Generate the parity bits
171 parityBits |= ((oddparity8(pbtCmd[i])) << (7-paritybit_cnt));
172 if (paritybit_cnt == 7) {
173 par[paritybyte_cnt] = parityBits; // save 8 Bits parity
174 parityBits = 0; // and advance to next Parity Byte
175 paritybyte_cnt++;
176 paritybit_cnt = 0;
177 } else {
178 paritybit_cnt++;
179 }
180 }
181
182 // save remaining parity bits
183 par[paritybyte_cnt] = parityBits;
184
185 }
186
187 void AppendCrc14443a(uint8_t* data, int len)
188 {
189 ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
190 }
191
192 void AppendCrc14443b(uint8_t* data, int len)
193 {
194 ComputeCrc14443(CRC_14443_B,data,len,data+len,data+len+1);
195 }
196
197
198 //=============================================================================
199 // ISO 14443 Type A - Miller decoder
200 //=============================================================================
201 // Basics:
202 // This decoder is used when the PM3 acts as a tag.
203 // The reader will generate "pauses" by temporarily switching of the field.
204 // At the PM3 antenna we will therefore measure a modulated antenna voltage.
205 // The FPGA does a comparison with a threshold and would deliver e.g.:
206 // ........ 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 .......
207 // The Miller decoder needs to identify the following sequences:
208 // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0")
209 // 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information")
210 // 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1")
211 // Note 1: the bitstream may start at any time. We therefore need to sync.
212 // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
213 //-----------------------------------------------------------------------------
214 static tUart Uart;
215
216 // Lookup-Table to decide if 4 raw bits are a modulation.
217 // We accept the following:
218 // 0001 - a 3 tick wide pause
219 // 0011 - a 2 tick wide pause, or a three tick wide pause shifted left
220 // 0111 - a 2 tick wide pause shifted left
221 // 1001 - a 2 tick wide pause shifted right
222 const bool Mod_Miller_LUT[] = {
223 FALSE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, TRUE,
224 FALSE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
225 };
226 #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4])
227 #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)])
228
229 void UartReset()
230 {
231 Uart.state = STATE_UNSYNCD;
232 Uart.bitCount = 0;
233 Uart.len = 0; // number of decoded data bytes
234 Uart.parityLen = 0; // number of decoded parity bytes
235 Uart.shiftReg = 0; // shiftreg to hold decoded data bits
236 Uart.parityBits = 0; // holds 8 parity bits
237 Uart.startTime = 0;
238 Uart.endTime = 0;
239
240 Uart.byteCntMax = 0;
241 Uart.posCnt = 0;
242 Uart.syncBit = 9999;
243 }
244
245 void UartInit(uint8_t *data, uint8_t *parity)
246 {
247 Uart.output = data;
248 Uart.parity = parity;
249 Uart.fourBits = 0x00000000; // clear the buffer for 4 Bits
250 UartReset();
251 }
252
253 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
254 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
255 {
256
257 Uart.fourBits = (Uart.fourBits << 8) | bit;
258
259 if (Uart.state == STATE_UNSYNCD) { // not yet synced
260
261 Uart.syncBit = 9999; // not set
262
263 // 00x11111 2|3 ticks pause followed by 6|5 ticks unmodulated Sequence Z (a "0" or "start of communication")
264 // 11111111 8 ticks unmodulation Sequence Y (a "0" or "end of communication" or "no information")
265 // 111100x1 4 ticks unmodulated followed by 2|3 ticks pause Sequence X (a "1")
266
267 // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from
268 // Sequence X followed by Sequence Y followed by Sequence Z (111100x1 11111111 00x11111)
269 // we therefore look for a ...xx1111 11111111 00x11111xxxxxx... pattern
270 // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's)
271 //
272 #define ISO14443A_STARTBIT_MASK 0x07FFEF80 // mask is 00001111 11111111 1110 1111 10000000
273 #define ISO14443A_STARTBIT_PATTERN 0x07FF8F80 // pattern is 00001111 11111111 1000 1111 10000000
274
275 if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7;
276 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6;
277 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5;
278 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4;
279 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3;
280 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2;
281 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1;
282 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0;
283
284 if (Uart.syncBit != 9999) { // found a sync bit
285 Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
286 Uart.startTime -= Uart.syncBit;
287 Uart.endTime = Uart.startTime;
288 Uart.state = STATE_START_OF_COMMUNICATION;
289 }
290
291 } else {
292
293 if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) {
294 if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation in both halves - error
295 UartReset();
296 } else { // Modulation in first half = Sequence Z = logic "0"
297 if (Uart.state == STATE_MILLER_X) { // error - must not follow after X
298 UartReset();
299 } else {
300 Uart.bitCount++;
301 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
302 Uart.state = STATE_MILLER_Z;
303 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
304 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
305 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
306 Uart.parityBits <<= 1; // make room for the parity bit
307 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
308 Uart.bitCount = 0;
309 Uart.shiftReg = 0;
310 if((Uart.len&0x0007) == 0) { // every 8 data bytes
311 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
312 Uart.parityBits = 0;
313 }
314 }
315 }
316 }
317 } else {
318 if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1"
319 Uart.bitCount++;
320 Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg
321 Uart.state = STATE_MILLER_X;
322 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
323 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
324 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
325 Uart.parityBits <<= 1; // make room for the new parity bit
326 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
327 Uart.bitCount = 0;
328 Uart.shiftReg = 0;
329 if ((Uart.len&0x0007) == 0) { // every 8 data bytes
330 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
331 Uart.parityBits = 0;
332 }
333 }
334 } else { // no modulation in both halves - Sequence Y
335 if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication
336 Uart.state = STATE_UNSYNCD;
337 Uart.bitCount--; // last "0" was part of EOC sequence
338 Uart.shiftReg <<= 1; // drop it
339 if(Uart.bitCount > 0) { // if we decoded some bits
340 Uart.shiftReg >>= (9 - Uart.bitCount); // right align them
341 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); // add last byte to the output
342 Uart.parityBits <<= 1; // add a (void) parity bit
343 Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align parity bits
344 Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store it
345 return TRUE;
346 } else if (Uart.len & 0x0007) { // there are some parity bits to store
347 Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align remaining parity bits
348 Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store them
349 }
350 if (Uart.len) {
351 return TRUE; // we are finished with decoding the raw data sequence
352 } else {
353 UartReset(); // Nothing received - start over
354 }
355 }
356 if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC
357 UartReset();
358 } else { // a logic "0"
359 Uart.bitCount++;
360 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
361 Uart.state = STATE_MILLER_Y;
362 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
363 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
364 Uart.parityBits <<= 1; // make room for the parity bit
365 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
366 Uart.bitCount = 0;
367 Uart.shiftReg = 0;
368 if ((Uart.len&0x0007) == 0) { // every 8 data bytes
369 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
370 Uart.parityBits = 0;
371 }
372 }
373 }
374 }
375 }
376
377 }
378
379 return FALSE; // not finished yet, need more data
380 }
381
382
383
384 //=============================================================================
385 // ISO 14443 Type A - Manchester decoder
386 //=============================================================================
387 // Basics:
388 // This decoder is used when the PM3 acts as a reader.
389 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
390 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
391 // ........ 0 0 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 .......
392 // The Manchester decoder needs to identify the following sequences:
393 // 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication")
394 // 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0
395 // 8 ticks unmodulated: Sequence F = end of communication
396 // 8 ticks modulated: A collision. Save the collision position and treat as Sequence D
397 // Note 1: the bitstream may start at any time. We therefore need to sync.
398 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
399 static tDemod Demod;
400
401 // Lookup-Table to decide if 4 raw bits are a modulation.
402 // We accept three or four "1" in any position
403 const bool Mod_Manchester_LUT[] = {
404 FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
405 FALSE, FALSE, FALSE, TRUE, FALSE, TRUE, TRUE, TRUE
406 };
407
408 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
409 #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
410
411
412 void DemodReset()
413 {
414 Demod.state = DEMOD_UNSYNCD;
415 Demod.len = 0; // number of decoded data bytes
416 Demod.parityLen = 0;
417 Demod.shiftReg = 0; // shiftreg to hold decoded data bits
418 Demod.parityBits = 0; //
419 Demod.collisionPos = 0; // Position of collision bit
420 Demod.twoBits = 0xffff; // buffer for 2 Bits
421 Demod.highCnt = 0;
422 Demod.startTime = 0;
423 Demod.endTime = 0;
424
425 //
426 Demod.bitCount = 0;
427 Demod.syncBit = 0xFFFF;
428 Demod.samples = 0;
429 }
430
431 void DemodInit(uint8_t *data, uint8_t *parity)
432 {
433 Demod.output = data;
434 Demod.parity = parity;
435 DemodReset();
436 }
437
438 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
439 static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
440 {
441
442 Demod.twoBits = (Demod.twoBits << 8) | bit;
443
444 if (Demod.state == DEMOD_UNSYNCD) {
445
446 if (Demod.highCnt < 2) { // wait for a stable unmodulated signal
447 if (Demod.twoBits == 0x0000) {
448 Demod.highCnt++;
449 } else {
450 Demod.highCnt = 0;
451 }
452 } else {
453 Demod.syncBit = 0xFFFF; // not set
454 if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
455 else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
456 else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
457 else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
458 else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
459 else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
460 else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
461 else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
462 if (Demod.syncBit != 0xFFFF) {
463 Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
464 Demod.startTime -= Demod.syncBit;
465 Demod.bitCount = offset; // number of decoded data bits
466 Demod.state = DEMOD_MANCHESTER_DATA;
467 }
468 }
469
470 } else {
471
472 if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half
473 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... and in second half = collision
474 if (!Demod.collisionPos) {
475 Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
476 }
477 } // modulation in first half only - Sequence D = 1
478 Demod.bitCount++;
479 Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg
480 if(Demod.bitCount == 9) { // if we decoded a full byte (including parity)
481 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
482 Demod.parityBits <<= 1; // make room for the parity bit
483 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
484 Demod.bitCount = 0;
485 Demod.shiftReg = 0;
486 if((Demod.len&0x0007) == 0) { // every 8 data bytes
487 Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits
488 Demod.parityBits = 0;
489 }
490 }
491 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
492 } else { // no modulation in first half
493 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // and modulation in second half = Sequence E = 0
494 Demod.bitCount++;
495 Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg
496 if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity)
497 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
498 Demod.parityBits <<= 1; // make room for the new parity bit
499 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
500 Demod.bitCount = 0;
501 Demod.shiftReg = 0;
502 if ((Demod.len&0x0007) == 0) { // every 8 data bytes
503 Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits1
504 Demod.parityBits = 0;
505 }
506 }
507 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
508 } else { // no modulation in both halves - End of communication
509 if(Demod.bitCount > 0) { // there are some remaining data bits
510 Demod.shiftReg >>= (9 - Demod.bitCount); // right align the decoded bits
511 Demod.output[Demod.len++] = Demod.shiftReg & 0xff; // and add them to the output
512 Demod.parityBits <<= 1; // add a (void) parity bit
513 Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
514 Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
515 return TRUE;
516 } else if (Demod.len & 0x0007) { // there are some parity bits to store
517 Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
518 Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
519 }
520 if (Demod.len) {
521 return TRUE; // we are finished with decoding the raw data sequence
522 } else { // nothing received. Start over
523 DemodReset();
524 }
525 }
526 }
527 }
528 return FALSE; // not finished yet, need more data
529 }
530
531 //=============================================================================
532 // Finally, a `sniffer' for ISO 14443 Type A
533 // Both sides of communication!
534 //=============================================================================
535
536 //-----------------------------------------------------------------------------
537 // Record the sequence of commands sent by the reader to the tag, with
538 // triggering so that we start recording at the point that the tag is moved
539 // near the reader.
540 //-----------------------------------------------------------------------------
541 void RAMFUNC SniffIso14443a(uint8_t param) {
542 // param:
543 // bit 0 - trigger from first card answer
544 // bit 1 - trigger from first reader 7-bit request
545 LEDsoff();
546
547 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
548
549 // Allocate memory from BigBuf for some buffers
550 // free all previous allocations first
551 BigBuf_free();
552
553 // init trace buffer
554 clear_trace();
555 set_tracing(TRUE);
556
557 // The command (reader -> tag) that we're receiving.
558 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
559 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
560
561 // The response (tag -> reader) that we're receiving.
562 uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
563 uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE);
564
565 // The DMA buffer, used to stream samples from the FPGA
566 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
567
568 uint8_t *data = dmaBuf;
569 uint8_t previous_data = 0;
570 int maxDataLen = 0;
571 int dataLen = 0;
572 bool TagIsActive = FALSE;
573 bool ReaderIsActive = FALSE;
574
575 // Set up the demodulator for tag -> reader responses.
576 DemodInit(receivedResponse, receivedResponsePar);
577
578 // Set up the demodulator for the reader -> tag commands
579 UartInit(receivedCmd, receivedCmdPar);
580
581 // Setup and start DMA.
582 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
583
584 // We won't start recording the frames that we acquire until we trigger;
585 // a good trigger condition to get started is probably when we see a
586 // response from the tag.
587 // triggered == FALSE -- to wait first for card
588 bool triggered = !(param & 0x03);
589
590 // And now we loop, receiving samples.
591 for(uint32_t rsamples = 0; TRUE; ) {
592
593 if(BUTTON_PRESS()) {
594 DbpString("cancelled by button");
595 break;
596 }
597
598 LED_A_ON();
599 WDT_HIT();
600
601 int register readBufDataP = data - dmaBuf;
602 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
603 if (readBufDataP <= dmaBufDataP){
604 dataLen = dmaBufDataP - readBufDataP;
605 } else {
606 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
607 }
608 // test for length of buffer
609 if(dataLen > maxDataLen) {
610 maxDataLen = dataLen;
611 if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
612 Dbprintf("blew circular buffer! dataLen=%d", dataLen);
613 break;
614 }
615 }
616 if(dataLen < 1) continue;
617
618 // primary buffer was stopped( <-- we lost data!
619 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
620 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
621 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
622 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
623 }
624 // secondary buffer sets as primary, secondary buffer was stopped
625 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
626 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
627 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
628 }
629
630 LED_A_OFF();
631
632 if (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder
633
634 if(!TagIsActive) { // no need to try decoding reader data if the tag is sending
635 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
636 if (MillerDecoding(readerdata, (rsamples-1)*4)) {
637 LED_C_ON();
638
639 // check - if there is a short 7bit request from reader
640 if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
641
642 if(triggered) {
643 if (!LogTrace(receivedCmd,
644 Uart.len,
645 Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
646 Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
647 Uart.parity,
648 TRUE)) break;
649 }
650 /* And ready to receive another command. */
651 UartReset();
652 /* And also reset the demod code, which might have been */
653 /* false-triggered by the commands from the reader. */
654 DemodReset();
655 LED_B_OFF();
656 }
657 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
658 }
659
660 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time
661 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
662 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
663 LED_B_ON();
664
665 if (!LogTrace(receivedResponse,
666 Demod.len,
667 Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
668 Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
669 Demod.parity,
670 FALSE)) break;
671
672 if ((!triggered) && (param & 0x01)) triggered = TRUE;
673
674 // And ready to receive another response.
675 DemodReset();
676 // And reset the Miller decoder including itS (now outdated) input buffer
677 UartInit(receivedCmd, receivedCmdPar);
678
679 LED_C_OFF();
680 }
681 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
682 }
683 }
684
685 previous_data = *data;
686 rsamples++;
687 data++;
688 if(data == dmaBuf + DMA_BUFFER_SIZE) {
689 data = dmaBuf;
690 }
691 } // main cycle
692
693 FpgaDisableSscDma();
694 LEDsoff();
695
696 Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
697 Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
698
699 set_tracing(FALSE);
700 }
701
702 //-----------------------------------------------------------------------------
703 // Prepare tag messages
704 //-----------------------------------------------------------------------------
705 static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity)
706 {
707 ToSendReset();
708
709 // Correction bit, might be removed when not needed
710 ToSendStuffBit(0);
711 ToSendStuffBit(0);
712 ToSendStuffBit(0);
713 ToSendStuffBit(0);
714 ToSendStuffBit(1); // 1
715 ToSendStuffBit(0);
716 ToSendStuffBit(0);
717 ToSendStuffBit(0);
718
719 // Send startbit
720 ToSend[++ToSendMax] = SEC_D;
721 LastProxToAirDuration = 8 * ToSendMax - 4;
722
723 for(uint16_t i = 0; i < len; i++) {
724 uint8_t b = cmd[i];
725
726 // Data bits
727 for(uint16_t j = 0; j < 8; j++) {
728 if(b & 1) {
729 ToSend[++ToSendMax] = SEC_D;
730 } else {
731 ToSend[++ToSendMax] = SEC_E;
732 }
733 b >>= 1;
734 }
735
736 // Get the parity bit
737 if (parity[i>>3] & (0x80>>(i&0x0007))) {
738 ToSend[++ToSendMax] = SEC_D;
739 LastProxToAirDuration = 8 * ToSendMax - 4;
740 } else {
741 ToSend[++ToSendMax] = SEC_E;
742 LastProxToAirDuration = 8 * ToSendMax;
743 }
744 }
745
746 // Send stopbit
747 ToSend[++ToSendMax] = SEC_F;
748
749 // Convert from last byte pos to length
750 ToSendMax++;
751 }
752
753 static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len)
754 {
755 uint8_t par[MAX_PARITY_SIZE];
756
757 GetParity(cmd, len, par);
758 CodeIso14443aAsTagPar(cmd, len, par);
759 }
760
761
762 static void Code4bitAnswerAsTag(uint8_t cmd)
763 {
764 int i;
765
766 ToSendReset();
767
768 // Correction bit, might be removed when not needed
769 ToSendStuffBit(0);
770 ToSendStuffBit(0);
771 ToSendStuffBit(0);
772 ToSendStuffBit(0);
773 ToSendStuffBit(1); // 1
774 ToSendStuffBit(0);
775 ToSendStuffBit(0);
776 ToSendStuffBit(0);
777
778 // Send startbit
779 ToSend[++ToSendMax] = SEC_D;
780
781 uint8_t b = cmd;
782 for(i = 0; i < 4; i++) {
783 if(b & 1) {
784 ToSend[++ToSendMax] = SEC_D;
785 LastProxToAirDuration = 8 * ToSendMax - 4;
786 } else {
787 ToSend[++ToSendMax] = SEC_E;
788 LastProxToAirDuration = 8 * ToSendMax;
789 }
790 b >>= 1;
791 }
792
793 // Send stopbit
794 ToSend[++ToSendMax] = SEC_F;
795
796 // Convert from last byte pos to length
797 ToSendMax++;
798 }
799
800 //-----------------------------------------------------------------------------
801 // Wait for commands from reader
802 // Stop when button is pressed
803 // Or return TRUE when command is captured
804 //-----------------------------------------------------------------------------
805 static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len)
806 {
807 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
808 // only, since we are receiving, not transmitting).
809 // Signal field is off with the appropriate LED
810 LED_D_OFF();
811 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
812
813 // Now run a `software UART' on the stream of incoming samples.
814 UartInit(received, parity);
815
816 // clear RXRDY:
817 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
818
819 for(;;) {
820 WDT_HIT();
821
822 if(BUTTON_PRESS()) return FALSE;
823
824 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
825 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
826 if(MillerDecoding(b, 0)) {
827 *len = Uart.len;
828 return TRUE;
829 }
830 }
831 }
832 }
833
834 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
835 int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
836 int EmSend4bit(uint8_t resp);
837 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par);
838 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
839 int EmSendCmd(uint8_t *resp, uint16_t respLen);
840 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par);
841 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
842 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity);
843
844 static uint8_t* free_buffer_pointer;
845
846 typedef struct {
847 uint8_t* response;
848 size_t response_n;
849 uint8_t* modulation;
850 size_t modulation_n;
851 uint32_t ProxToAirDuration;
852 } tag_response_info_t;
853
854 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
855 // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
856 // This will need the following byte array for a modulation sequence
857 // 144 data bits (18 * 8)
858 // 18 parity bits
859 // 2 Start and stop
860 // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA)
861 // 1 just for the case
862 // ----------- +
863 // 166 bytes, since every bit that needs to be send costs us a byte
864 //
865
866
867 // Prepare the tag modulation bits from the message
868 CodeIso14443aAsTag(response_info->response,response_info->response_n);
869
870 // Make sure we do not exceed the free buffer space
871 if (ToSendMax > max_buffer_size) {
872 Dbprintf("Out of memory, when modulating bits for tag answer:");
873 Dbhexdump(response_info->response_n,response_info->response,false);
874 return false;
875 }
876
877 // Copy the byte array, used for this modulation to the buffer position
878 memcpy(response_info->modulation,ToSend,ToSendMax);
879
880 // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
881 response_info->modulation_n = ToSendMax;
882 response_info->ProxToAirDuration = LastProxToAirDuration;
883
884 return true;
885 }
886
887
888 // "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit.
889 // Coded responses need one byte per bit to transfer (data, parity, start, stop, correction)
890 // 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits
891 // -> need 273 bytes buffer
892 // 44 * 8 data bits, 44 * 1 parity bits, 9 start bits, 9 stop bits, 9 correction bits --370
893 // 47 * 8 data bits, 47 * 1 parity bits, 10 start bits, 10 stop bits, 10 correction bits
894 #define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 453
895
896 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
897 // Retrieve and store the current buffer index
898 response_info->modulation = free_buffer_pointer;
899
900 // Determine the maximum size we can use from our buffer
901 size_t max_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE;
902
903 // Forward the prepare tag modulation function to the inner function
904 if (prepare_tag_modulation(response_info, max_buffer_size)) {
905 // Update the free buffer offset
906 free_buffer_pointer += ToSendMax;
907 return true;
908 } else {
909 return false;
910 }
911 }
912
913 //-----------------------------------------------------------------------------
914 // Main loop of simulated tag: receive commands from reader, decide what
915 // response to send, and send it.
916 //-----------------------------------------------------------------------------
917 void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
918 {
919 uint32_t counters[] = {0,0,0};
920 //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
921 // This can be used in a reader-only attack.
922 // (it can also be retrieved via 'hf 14a list', but hey...
923 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0,0,0};
924 uint8_t ar_nr_collected = 0;
925
926 uint8_t sak;
927
928 // PACK response to PWD AUTH for EV1/NTAG
929 uint8_t response8[4] = {0,0,0,0};
930
931 // The first response contains the ATQA (note: bytes are transmitted in reverse order).
932 uint8_t response1[2] = {0,0};
933
934 switch (tagType) {
935 case 1: { // MIFARE Classic
936 // Says: I am Mifare 1k - original line
937 response1[0] = 0x04;
938 response1[1] = 0x00;
939 sak = 0x08;
940 } break;
941 case 2: { // MIFARE Ultralight
942 // Says: I am a stupid memory tag, no crypto
943 response1[0] = 0x44;
944 response1[1] = 0x00;
945 sak = 0x00;
946 } break;
947 case 3: { // MIFARE DESFire
948 // Says: I am a DESFire tag, ph33r me
949 response1[0] = 0x04;
950 response1[1] = 0x03;
951 sak = 0x20;
952 } break;
953 case 4: { // ISO/IEC 14443-4
954 // Says: I am a javacard (JCOP)
955 response1[0] = 0x04;
956 response1[1] = 0x00;
957 sak = 0x28;
958 } break;
959 case 5: { // MIFARE TNP3XXX
960 // Says: I am a toy
961 response1[0] = 0x01;
962 response1[1] = 0x0f;
963 sak = 0x01;
964 } break;
965 case 6: { // MIFARE Mini
966 // Says: I am a Mifare Mini, 320b
967 response1[0] = 0x44;
968 response1[1] = 0x00;
969 sak = 0x09;
970 } break;
971 case 7: { // NTAG?
972 // Says: I am a NTAG,
973 response1[0] = 0x44;
974 response1[1] = 0x00;
975 sak = 0x00;
976 // PACK
977 response8[0] = 0x80;
978 response8[1] = 0x80;
979 ComputeCrc14443(CRC_14443_A, response8, 2, &response8[2], &response8[3]);
980 // uid not supplied then get from emulator memory
981 if (data[0]==0) {
982 uint16_t start = 4 * (0+12);
983 uint8_t emdata[8];
984 emlGetMemBt( emdata, start, sizeof(emdata));
985 memcpy(data, emdata, 3); //uid bytes 0-2
986 memcpy(data+3, emdata+4, 4); //uid bytes 3-7
987 flags |= FLAG_7B_UID_IN_DATA;
988 }
989 } break;
990 default: {
991 Dbprintf("Error: unkown tagtype (%d)",tagType);
992 return;
993 } break;
994 }
995
996 // The second response contains the (mandatory) first 24 bits of the UID
997 uint8_t response2[5] = {0x00};
998
999 // Check if the uid uses the (optional) part
1000 uint8_t response2a[5] = {0x00};
1001
1002 if (flags & FLAG_7B_UID_IN_DATA) {
1003 response2[0] = 0x88;
1004 response2[1] = data[0];
1005 response2[2] = data[1];
1006 response2[3] = data[2];
1007
1008 response2a[0] = data[3];
1009 response2a[1] = data[4];
1010 response2a[2] = data[5];
1011 response2a[3] = data[6]; //??
1012 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
1013
1014 // Configure the ATQA and SAK accordingly
1015 response1[0] |= 0x40;
1016 sak |= 0x04;
1017 } else {
1018 memcpy(response2, data, 4);
1019 //num_to_bytes(uid_1st,4,response2);
1020 // Configure the ATQA and SAK accordingly
1021 response1[0] &= 0xBF;
1022 sak &= 0xFB;
1023 }
1024
1025 // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
1026 response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
1027
1028 // Prepare the mandatory SAK (for 4 and 7 byte UID)
1029 uint8_t response3[3] = {0x00};
1030 response3[0] = sak;
1031 ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
1032
1033 // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
1034 uint8_t response3a[3] = {0x00};
1035 response3a[0] = sak & 0xFB;
1036 ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
1037
1038 uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
1039 uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS:
1040 // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
1041 // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
1042 // TB(1) = not present. Defaults: FWI = 4 (FWT = 256 * 16 * 2^4 * 1/fc = 4833us), SFGI = 0 (SFG = 256 * 16 * 2^0 * 1/fc = 302us)
1043 // TC(1) = 0x02: CID supported, NAD not supported
1044 ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
1045
1046 // Prepare GET_VERSION (different for UL EV-1 / NTAG)
1047 //uint8_t response7_EV1[] = {0x00, 0x04, 0x03, 0x01, 0x01, 0x00, 0x0b, 0x03, 0xfd, 0xf7}; //EV1 48bytes VERSION.
1048 //uint8_t response7_NTAG[] = {0x00, 0x04, 0x04, 0x02, 0x01, 0x00, 0x11, 0x03, 0x01, 0x9e}; //NTAG 215
1049
1050 // Prepare CHK_TEARING
1051 //uint8_t response9[] = {0xBD,0x90,0x3f};
1052
1053 #define TAG_RESPONSE_COUNT 10
1054 tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
1055 { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type
1056 { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid
1057 { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked
1058 { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1
1059 { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2
1060 { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce)
1061 { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS
1062 //{ .response = response7_NTAG, .response_n = sizeof(response7_NTAG)}, // EV1/NTAG GET_VERSION response
1063 { .response = response8, .response_n = sizeof(response8) }, // EV1/NTAG PACK response
1064 //{ .response = response9, .response_n = sizeof(response9) } // EV1/NTAG CHK_TEAR response
1065 };
1066
1067 // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
1068 // Such a response is less time critical, so we can prepare them on the fly
1069 #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
1070 #define DYNAMIC_MODULATION_BUFFER_SIZE 512
1071 uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
1072 uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
1073 tag_response_info_t dynamic_response_info = {
1074 .response = dynamic_response_buffer,
1075 .response_n = 0,
1076 .modulation = dynamic_modulation_buffer,
1077 .modulation_n = 0
1078 };
1079
1080 // We need to listen to the high-frequency, peak-detected path.
1081 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1082
1083 BigBuf_free_keep_EM();
1084
1085 // allocate buffers:
1086 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
1087 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
1088 free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
1089
1090 // clear trace
1091 clear_trace();
1092 set_tracing(TRUE);
1093
1094 // Prepare the responses of the anticollision phase
1095 // there will be not enough time to do this at the moment the reader sends it REQA
1096 for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
1097 prepare_allocated_tag_modulation(&responses[i]);
1098 }
1099
1100 int len = 0;
1101
1102 // To control where we are in the protocol
1103 int order = 0;
1104 int lastorder;
1105
1106 // Just to allow some checks
1107 int happened = 0;
1108 int happened2 = 0;
1109 int cmdsRecvd = 0;
1110
1111 cmdsRecvd = 0;
1112 tag_response_info_t* p_response;
1113
1114 LED_A_ON();
1115 for(;;) {
1116 // Clean receive command buffer
1117 if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
1118 DbpString("Button press");
1119 break;
1120 }
1121
1122 p_response = NULL;
1123
1124 // Okay, look at the command now.
1125 lastorder = order;
1126 if(receivedCmd[0] == 0x26) { // Received a REQUEST
1127 p_response = &responses[0]; order = 1;
1128 } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
1129 p_response = &responses[0]; order = 6;
1130 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // Received request for UID (cascade 1)
1131 p_response = &responses[1]; order = 2;
1132 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2)
1133 p_response = &responses[2]; order = 20;
1134 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) { // Received a SELECT (cascade 1)
1135 p_response = &responses[3]; order = 3;
1136 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) { // Received a SELECT (cascade 2)
1137 p_response = &responses[4]; order = 30;
1138 } else if(receivedCmd[0] == 0x30) { // Received a (plain) READ
1139 uint8_t block = receivedCmd[1];
1140 // if Ultralight or NTAG (4 byte blocks)
1141 if ( tagType == 7 || tagType == 2 ) {
1142 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1143 uint16_t start = 4 * (block+12);
1144 uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
1145 emlGetMemBt( emdata, start, 16);
1146 AppendCrc14443a(emdata, 16);
1147 EmSendCmdEx(emdata, sizeof(emdata), false);
1148 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1149 p_response = NULL;
1150 } else { // all other tags (16 byte block tags)
1151 EmSendCmdEx(data+(4*receivedCmd[1]),16,false);
1152 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1153 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1154 p_response = NULL;
1155 }
1156 } else if(receivedCmd[0] == 0x3A) { // Received a FAST READ (ranged read)
1157
1158 uint8_t emdata[MAX_FRAME_SIZE];
1159 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1160 int start = (receivedCmd[1]+12) * 4;
1161 int len = (receivedCmd[2] - receivedCmd[1] + 1) * 4;
1162 emlGetMemBt( emdata, start, len);
1163 AppendCrc14443a(emdata, len);
1164 EmSendCmdEx(emdata, len+2, false);
1165 p_response = NULL;
1166
1167 } else if(receivedCmd[0] == 0x3C && tagType == 7) { // Received a READ SIGNATURE --
1168 // ECC data, taken from a NTAG215 amiibo token. might work. LEN: 32, + 2 crc
1169 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1170 uint16_t start = 4 * 4;
1171 uint8_t emdata[34];
1172 emlGetMemBt( emdata, start, 32);
1173 AppendCrc14443a(emdata, 32);
1174 EmSendCmdEx(emdata, sizeof(emdata), false);
1175 //uint8_t data[] = {0x56,0x06,0xa6,0x4f,0x43,0x32,0x53,0x6f,
1176 // 0x43,0xda,0x45,0xd6,0x61,0x38,0xaa,0x1e,
1177 // 0xcf,0xd3,0x61,0x36,0xca,0x5f,0xbb,0x05,
1178 // 0xce,0x21,0x24,0x5b,0xa6,0x7a,0x79,0x07,
1179 // 0x00,0x00};
1180 //AppendCrc14443a(data, sizeof(data)-2);
1181 //EmSendCmdEx(data,sizeof(data),false);
1182 p_response = NULL;
1183 } else if (receivedCmd[0] == 0x39 && tagType == 7) { // Received a READ COUNTER --
1184 uint8_t index = receivedCmd[1];
1185 uint8_t data[] = {0x00,0x00,0x00,0x14,0xa5};
1186 if ( counters[index] > 0) {
1187 num_to_bytes(counters[index], 3, data);
1188 AppendCrc14443a(data, sizeof(data)-2);
1189 }
1190 EmSendCmdEx(data,sizeof(data),false);
1191 p_response = NULL;
1192 } else if (receivedCmd[0] == 0xA5 && tagType == 7) { // Received a INC COUNTER --
1193 // number of counter
1194 uint8_t counter = receivedCmd[1];
1195 uint32_t val = bytes_to_num(receivedCmd+2,4);
1196 counters[counter] = val;
1197
1198 // send ACK
1199 uint8_t ack[] = {0x0a};
1200 EmSendCmdEx(ack,sizeof(ack),false);
1201 p_response = NULL;
1202
1203 } else if(receivedCmd[0] == 0x3E && tagType == 7) { // Received a CHECK_TEARING_EVENT --
1204 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1205 uint8_t emdata[3];
1206 uint8_t counter=0;
1207 if (receivedCmd[1]<3) counter = receivedCmd[1];
1208 emlGetMemBt( emdata, 10+counter, 1);
1209 AppendCrc14443a(emdata, sizeof(emdata)-2);
1210 EmSendCmdEx(emdata, sizeof(emdata), false);
1211 p_response = NULL;
1212 //p_response = &responses[9];
1213
1214 } else if(receivedCmd[0] == 0x50) { // Received a HALT
1215
1216 if (tracing) {
1217 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1218 }
1219 p_response = NULL;
1220 } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) { // Received an authentication request
1221
1222 if ( tagType == 7 ) { // IF NTAG /EV1 0x60 == GET_VERSION, not a authentication request.
1223 uint8_t emdata[10];
1224 emlGetMemBt( emdata, 0, 8 );
1225 AppendCrc14443a(emdata, sizeof(emdata)-2);
1226 EmSendCmdEx(emdata, sizeof(emdata), false);
1227 p_response = NULL;
1228 //p_response = &responses[7];
1229 } else {
1230 p_response = &responses[5]; order = 7;
1231 }
1232 } else if(receivedCmd[0] == 0xE0) { // Received a RATS request
1233 if (tagType == 1 || tagType == 2) { // RATS not supported
1234 EmSend4bit(CARD_NACK_NA);
1235 p_response = NULL;
1236 } else {
1237 p_response = &responses[6]; order = 70;
1238 }
1239 } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
1240 if (tracing) {
1241 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1242 }
1243 uint32_t nonce = bytes_to_num(response5,4);
1244 uint32_t nr = bytes_to_num(receivedCmd,4);
1245 uint32_t ar = bytes_to_num(receivedCmd+4,4);
1246 //Dbprintf("Auth attempt {nonce}{nr}{ar}: %08x %08x %08x", nonce, nr, ar);
1247
1248 if(flags & FLAG_NR_AR_ATTACK )
1249 {
1250 if(ar_nr_collected < 2){
1251 // Avoid duplicates... probably not necessary, nr should vary.
1252 //if(ar_nr_responses[3] != nr){
1253 ar_nr_responses[ar_nr_collected*5] = 0;
1254 ar_nr_responses[ar_nr_collected*5+1] = 0;
1255 ar_nr_responses[ar_nr_collected*5+2] = nonce;
1256 ar_nr_responses[ar_nr_collected*5+3] = nr;
1257 ar_nr_responses[ar_nr_collected*5+4] = ar;
1258 ar_nr_collected++;
1259 //}
1260 }
1261
1262 if(ar_nr_collected > 1 ) {
1263
1264 if (MF_DBGLEVEL >= 2) {
1265 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
1266 Dbprintf("../tools/mfkey/mfkey32 %07x%08x %08x %08x %08x %08x %08x",
1267 ar_nr_responses[0], // UID1
1268 ar_nr_responses[1], // UID2
1269 ar_nr_responses[2], // NT
1270 ar_nr_responses[3], // AR1
1271 ar_nr_responses[4], // NR1
1272 ar_nr_responses[8], // AR2
1273 ar_nr_responses[9] // NR2
1274 );
1275 Dbprintf("../tools/mfkey/mfkey32v2 %06x%08x %08x %08x %08x %08x %08x %08x",
1276 ar_nr_responses[0], // UID1
1277 ar_nr_responses[1], // UID2
1278 ar_nr_responses[2], // NT1
1279 ar_nr_responses[3], // AR1
1280 ar_nr_responses[4], // NR1
1281 ar_nr_responses[7], // NT2
1282 ar_nr_responses[8], // AR2
1283 ar_nr_responses[9] // NR2
1284 );
1285 }
1286 uint8_t len = ar_nr_collected*5*4;
1287 cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,len,0,&ar_nr_responses,len);
1288 ar_nr_collected = 0;
1289 memset(ar_nr_responses, 0x00, len);
1290 }
1291 }
1292 } else if (receivedCmd[0] == 0x1a ) // ULC authentication
1293 {
1294
1295 }
1296 else if (receivedCmd[0] == 0x1b) // NTAG / EV-1 authentication
1297 {
1298 if ( tagType == 7 ) {
1299 uint16_t start = 13; //first 4 blocks of emu are [getversion answer - check tearing - pack - 0x00]
1300 uint8_t emdata[4];
1301 emlGetMemBt( emdata, start, 2);
1302 AppendCrc14443a(emdata, 2);
1303 EmSendCmdEx(emdata, sizeof(emdata), false);
1304 p_response = NULL;
1305 //p_response = &responses[8]; // PACK response
1306 uint32_t pwd = bytes_to_num(receivedCmd+1,4);
1307
1308 if ( MF_DBGLEVEL >= 3) Dbprintf("Auth attempt: %08x", pwd);
1309 }
1310 } else {
1311 // Check for ISO 14443A-4 compliant commands, look at left nibble
1312 switch (receivedCmd[0]) {
1313 case 0x02:
1314 case 0x03: { // IBlock (command no CID)
1315 dynamic_response_info.response[0] = receivedCmd[0];
1316 dynamic_response_info.response[1] = 0x90;
1317 dynamic_response_info.response[2] = 0x00;
1318 dynamic_response_info.response_n = 3;
1319 } break;
1320 case 0x0B:
1321 case 0x0A: { // IBlock (command CID)
1322 dynamic_response_info.response[0] = receivedCmd[0];
1323 dynamic_response_info.response[1] = 0x00;
1324 dynamic_response_info.response[2] = 0x90;
1325 dynamic_response_info.response[3] = 0x00;
1326 dynamic_response_info.response_n = 4;
1327 } break;
1328
1329 case 0x1A:
1330 case 0x1B: { // Chaining command
1331 dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1332 dynamic_response_info.response_n = 2;
1333 } break;
1334
1335 case 0xaa:
1336 case 0xbb: {
1337 dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1338 dynamic_response_info.response_n = 2;
1339 } break;
1340
1341 case 0xBA: { // ping / pong
1342 dynamic_response_info.response[0] = 0xAB;
1343 dynamic_response_info.response[1] = 0x00;
1344 dynamic_response_info.response_n = 2;
1345 } break;
1346
1347 case 0xCA:
1348 case 0xC2: { // Readers sends deselect command
1349 dynamic_response_info.response[0] = 0xCA;
1350 dynamic_response_info.response[1] = 0x00;
1351 dynamic_response_info.response_n = 2;
1352 } break;
1353
1354 default: {
1355 // Never seen this command before
1356 if (tracing) {
1357 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1358 }
1359 Dbprintf("Received unknown command (len=%d):",len);
1360 Dbhexdump(len,receivedCmd,false);
1361 // Do not respond
1362 dynamic_response_info.response_n = 0;
1363 } break;
1364 }
1365
1366 if (dynamic_response_info.response_n > 0) {
1367 // Copy the CID from the reader query
1368 dynamic_response_info.response[1] = receivedCmd[1];
1369
1370 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1371 AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
1372 dynamic_response_info.response_n += 2;
1373
1374 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1375 Dbprintf("Error preparing tag response");
1376 if (tracing) {
1377 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1378 }
1379 break;
1380 }
1381 p_response = &dynamic_response_info;
1382 }
1383 }
1384
1385 // Count number of wakeups received after a halt
1386 if(order == 6 && lastorder == 5) { happened++; }
1387
1388 // Count number of other messages after a halt
1389 if(order != 6 && lastorder == 5) { happened2++; }
1390
1391 if(cmdsRecvd > 999) {
1392 DbpString("1000 commands later...");
1393 break;
1394 }
1395 cmdsRecvd++;
1396
1397 if (p_response != NULL) {
1398 EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1399 // do the tracing for the previous reader request and this tag answer:
1400 uint8_t par[MAX_PARITY_SIZE];
1401 GetParity(p_response->response, p_response->response_n, par);
1402
1403 EmLogTrace(Uart.output,
1404 Uart.len,
1405 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1406 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1407 Uart.parity,
1408 p_response->response,
1409 p_response->response_n,
1410 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1411 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1412 par);
1413 }
1414
1415 if (!tracing) {
1416 Dbprintf("Trace Full. Simulation stopped.");
1417 break;
1418 }
1419 }
1420
1421 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1422 set_tracing(FALSE);
1423 BigBuf_free_keep_EM();
1424 LED_A_OFF();
1425
1426 if (MF_DBGLEVEL >= 4){
1427 Dbprintf("-[ Wake ups after halt [%d]", happened);
1428 Dbprintf("-[ Messages after halt [%d]", happened2);
1429 Dbprintf("-[ Num of received cmd [%d]", cmdsRecvd);
1430 }
1431 }
1432
1433
1434 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1435 // of bits specified in the delay parameter.
1436 void PrepareDelayedTransfer(uint16_t delay)
1437 {
1438 uint8_t bitmask = 0;
1439 uint8_t bits_to_shift = 0;
1440 uint8_t bits_shifted = 0;
1441
1442 delay &= 0x07;
1443 if (delay) {
1444 for (uint16_t i = 0; i < delay; i++) {
1445 bitmask |= (0x01 << i);
1446 }
1447 ToSend[ToSendMax++] = 0x00;
1448 for (uint16_t i = 0; i < ToSendMax; i++) {
1449 bits_to_shift = ToSend[i] & bitmask;
1450 ToSend[i] = ToSend[i] >> delay;
1451 ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1452 bits_shifted = bits_to_shift;
1453 }
1454 }
1455 }
1456
1457
1458 //-------------------------------------------------------------------------------------
1459 // Transmit the command (to the tag) that was placed in ToSend[].
1460 // Parameter timing:
1461 // if NULL: transfer at next possible time, taking into account
1462 // request guard time and frame delay time
1463 // if == 0: transfer immediately and return time of transfer
1464 // if != 0: delay transfer until time specified
1465 //-------------------------------------------------------------------------------------
1466 static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing)
1467 {
1468
1469 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1470
1471 uint32_t ThisTransferTime = 0;
1472
1473 if (timing) {
1474 if(*timing == 0) { // Measure time
1475 *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1476 } else {
1477 PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
1478 }
1479 if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
1480 while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
1481 LastTimeProxToAirStart = *timing;
1482 } else {
1483 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1484 while(GetCountSspClk() < ThisTransferTime);
1485 LastTimeProxToAirStart = ThisTransferTime;
1486 }
1487
1488 // clear TXRDY
1489 AT91C_BASE_SSC->SSC_THR = SEC_Y;
1490
1491 uint16_t c = 0;
1492 for(;;) {
1493 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1494 AT91C_BASE_SSC->SSC_THR = cmd[c];
1495 c++;
1496 if(c >= len) {
1497 break;
1498 }
1499 }
1500 }
1501
1502 NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1503 }
1504
1505
1506 //-----------------------------------------------------------------------------
1507 // Prepare reader command (in bits, support short frames) to send to FPGA
1508 //-----------------------------------------------------------------------------
1509 void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity)
1510 {
1511 int i, j;
1512 int last;
1513 uint8_t b;
1514
1515 ToSendReset();
1516
1517 // Start of Communication (Seq. Z)
1518 ToSend[++ToSendMax] = SEC_Z;
1519 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1520 last = 0;
1521
1522 size_t bytecount = nbytes(bits);
1523 // Generate send structure for the data bits
1524 for (i = 0; i < bytecount; i++) {
1525 // Get the current byte to send
1526 b = cmd[i];
1527 size_t bitsleft = MIN((bits-(i*8)),8);
1528
1529 for (j = 0; j < bitsleft; j++) {
1530 if (b & 1) {
1531 // Sequence X
1532 ToSend[++ToSendMax] = SEC_X;
1533 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1534 last = 1;
1535 } else {
1536 if (last == 0) {
1537 // Sequence Z
1538 ToSend[++ToSendMax] = SEC_Z;
1539 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1540 } else {
1541 // Sequence Y
1542 ToSend[++ToSendMax] = SEC_Y;
1543 last = 0;
1544 }
1545 }
1546 b >>= 1;
1547 }
1548
1549 // Only transmit parity bit if we transmitted a complete byte
1550 if (j == 8 && parity != NULL) {
1551 // Get the parity bit
1552 if (parity[i>>3] & (0x80 >> (i&0x0007))) {
1553 // Sequence X
1554 ToSend[++ToSendMax] = SEC_X;
1555 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1556 last = 1;
1557 } else {
1558 if (last == 0) {
1559 // Sequence Z
1560 ToSend[++ToSendMax] = SEC_Z;
1561 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1562 } else {
1563 // Sequence Y
1564 ToSend[++ToSendMax] = SEC_Y;
1565 last = 0;
1566 }
1567 }
1568 }
1569 }
1570
1571 // End of Communication: Logic 0 followed by Sequence Y
1572 if (last == 0) {
1573 // Sequence Z
1574 ToSend[++ToSendMax] = SEC_Z;
1575 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1576 } else {
1577 // Sequence Y
1578 ToSend[++ToSendMax] = SEC_Y;
1579 last = 0;
1580 }
1581 ToSend[++ToSendMax] = SEC_Y;
1582
1583 // Convert to length of command:
1584 ToSendMax++;
1585 }
1586
1587 //-----------------------------------------------------------------------------
1588 // Prepare reader command to send to FPGA
1589 //-----------------------------------------------------------------------------
1590 void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity)
1591 {
1592 CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
1593 }
1594
1595
1596 //-----------------------------------------------------------------------------
1597 // Wait for commands from reader
1598 // Stop when button is pressed (return 1) or field was gone (return 2)
1599 // Or return 0 when command is captured
1600 //-----------------------------------------------------------------------------
1601 static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity)
1602 {
1603 *len = 0;
1604
1605 uint32_t timer = 0, vtime = 0;
1606 int analogCnt = 0;
1607 int analogAVG = 0;
1608
1609 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1610 // only, since we are receiving, not transmitting).
1611 // Signal field is off with the appropriate LED
1612 LED_D_OFF();
1613 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1614
1615 // Set ADC to read field strength
1616 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1617 AT91C_BASE_ADC->ADC_MR =
1618 ADC_MODE_PRESCALE(63) |
1619 ADC_MODE_STARTUP_TIME(1) |
1620 ADC_MODE_SAMPLE_HOLD_TIME(15);
1621 AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1622 // start ADC
1623 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1624
1625 // Now run a 'software UART' on the stream of incoming samples.
1626 UartInit(received, parity);
1627
1628 // Clear RXRDY:
1629 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1630
1631 for(;;) {
1632 WDT_HIT();
1633
1634 if (BUTTON_PRESS()) return 1;
1635
1636 // test if the field exists
1637 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1638 analogCnt++;
1639 analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1640 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1641 if (analogCnt >= 32) {
1642 if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1643 vtime = GetTickCount();
1644 if (!timer) timer = vtime;
1645 // 50ms no field --> card to idle state
1646 if (vtime - timer > 50) return 2;
1647 } else
1648 if (timer) timer = 0;
1649 analogCnt = 0;
1650 analogAVG = 0;
1651 }
1652 }
1653
1654 // receive and test the miller decoding
1655 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1656 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1657 if(MillerDecoding(b, 0)) {
1658 *len = Uart.len;
1659 return 0;
1660 }
1661 }
1662
1663 }
1664 }
1665
1666
1667 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded)
1668 {
1669 uint8_t b;
1670 uint16_t i = 0;
1671 uint32_t ThisTransferTime;
1672
1673 // Modulate Manchester
1674 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1675
1676 // include correction bit if necessary
1677 if (Uart.parityBits & 0x01) {
1678 correctionNeeded = TRUE;
1679 }
1680 if(correctionNeeded) {
1681 // 1236, so correction bit needed
1682 i = 0;
1683 } else {
1684 i = 1;
1685 }
1686
1687 // clear receiving shift register and holding register
1688 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1689 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1690 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1691 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1692
1693 // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1694 for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never
1695 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1696 if (AT91C_BASE_SSC->SSC_RHR) break;
1697 }
1698
1699 while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1700
1701 // Clear TXRDY:
1702 AT91C_BASE_SSC->SSC_THR = SEC_F;
1703
1704 // send cycle
1705 for(; i < respLen; ) {
1706 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1707 AT91C_BASE_SSC->SSC_THR = resp[i++];
1708 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1709 }
1710
1711 if(BUTTON_PRESS()) break;
1712 }
1713
1714 // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1715 uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3;
1716 for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
1717 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1718 AT91C_BASE_SSC->SSC_THR = SEC_F;
1719 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1720 i++;
1721 }
1722 }
1723
1724 LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
1725
1726 return 0;
1727 }
1728
1729 int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
1730 Code4bitAnswerAsTag(resp);
1731 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1732 // do the tracing for the previous reader request and this tag answer:
1733 uint8_t par[1];
1734 GetParity(&resp, 1, par);
1735 EmLogTrace(Uart.output,
1736 Uart.len,
1737 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1738 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1739 Uart.parity,
1740 &resp,
1741 1,
1742 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1743 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1744 par);
1745 return res;
1746 }
1747
1748 int EmSend4bit(uint8_t resp){
1749 return EmSend4bitEx(resp, false);
1750 }
1751
1752 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){
1753 CodeIso14443aAsTagPar(resp, respLen, par);
1754 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1755 // do the tracing for the previous reader request and this tag answer:
1756 EmLogTrace(Uart.output,
1757 Uart.len,
1758 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1759 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1760 Uart.parity,
1761 resp,
1762 respLen,
1763 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1764 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1765 par);
1766 return res;
1767 }
1768
1769 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){
1770 uint8_t par[MAX_PARITY_SIZE];
1771 GetParity(resp, respLen, par);
1772 return EmSendCmdExPar(resp, respLen, correctionNeeded, par);
1773 }
1774
1775 int EmSendCmd(uint8_t *resp, uint16_t respLen){
1776 uint8_t par[MAX_PARITY_SIZE];
1777 GetParity(resp, respLen, par);
1778 return EmSendCmdExPar(resp, respLen, false, par);
1779 }
1780
1781 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
1782 return EmSendCmdExPar(resp, respLen, false, par);
1783 }
1784
1785 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
1786 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity)
1787 {
1788 if (tracing) {
1789 // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1790 // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1791 // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1792 uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1793 uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1794 uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1795 reader_EndTime = tag_StartTime - exact_fdt;
1796 reader_StartTime = reader_EndTime - reader_modlen;
1797 if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE)) {
1798 return FALSE;
1799 } else return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
1800 } else {
1801 return TRUE;
1802 }
1803 }
1804
1805 //-----------------------------------------------------------------------------
1806 // Wait a certain time for tag response
1807 // If a response is captured return TRUE
1808 // If it takes too long return FALSE
1809 //-----------------------------------------------------------------------------
1810 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset)
1811 {
1812 uint32_t c = 0x00;
1813
1814 // Set FPGA mode to "reader listen mode", no modulation (listen
1815 // only, since we are receiving, not transmitting).
1816 // Signal field is on with the appropriate LED
1817 LED_D_ON();
1818 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1819
1820 // Now get the answer from the card
1821 DemodInit(receivedResponse, receivedResponsePar);
1822
1823 // clear RXRDY:
1824 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1825
1826 for(;;) {
1827 WDT_HIT();
1828
1829 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1830 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1831 if(ManchesterDecoding(b, offset, 0)) {
1832 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1833 return TRUE;
1834 } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
1835 return FALSE;
1836 }
1837 }
1838 }
1839 }
1840
1841 void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing)
1842 {
1843 CodeIso14443aBitsAsReaderPar(frame, bits, par);
1844
1845 // Send command to tag
1846 TransmitFor14443a(ToSend, ToSendMax, timing);
1847 if(trigger)
1848 LED_A_ON();
1849
1850 // Log reader command in trace buffer
1851 if (tracing) {
1852 LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
1853 }
1854 }
1855
1856 void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing)
1857 {
1858 ReaderTransmitBitsPar(frame, len*8, par, timing);
1859 }
1860
1861 void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing)
1862 {
1863 // Generate parity and redirect
1864 uint8_t par[MAX_PARITY_SIZE];
1865 GetParity(frame, len/8, par);
1866 ReaderTransmitBitsPar(frame, len, par, timing);
1867 }
1868
1869 void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing)
1870 {
1871 // Generate parity and redirect
1872 uint8_t par[MAX_PARITY_SIZE];
1873 GetParity(frame, len, par);
1874 ReaderTransmitBitsPar(frame, len*8, par, timing);
1875 }
1876
1877 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity)
1878 {
1879 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset)) return FALSE;
1880 if (tracing) {
1881 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1882 }
1883 return Demod.len;
1884 }
1885
1886 int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
1887 {
1888 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0)) return FALSE;
1889 if (tracing) {
1890 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1891 }
1892 return Demod.len;
1893 }
1894
1895 // performs iso14443a anticollision (optional) and card select procedure
1896 // fills the uid and cuid pointer unless NULL
1897 // fills the card info record unless NULL
1898 // if anticollision is false, then the UID must be provided in uid_ptr[]
1899 // and num_cascades must be set (1: 4 Byte UID, 2: 7 Byte UID, 3: 10 Byte UID)
1900 int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr, bool anticollision, uint8_t num_cascades) {
1901 uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP
1902 uint8_t sel_all[] = { 0x93,0x20 };
1903 uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1904 uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1905 uint8_t resp[MAX_FRAME_SIZE]; // theoretically. A usual RATS will be much smaller
1906 uint8_t resp_par[MAX_PARITY_SIZE];
1907 byte_t uid_resp[4];
1908 size_t uid_resp_len;
1909
1910 uint8_t sak = 0x04; // cascade uid
1911 int cascade_level = 0;
1912 int len;
1913
1914 // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1915 ReaderTransmitBitsPar(wupa, 7, NULL, NULL);
1916
1917 // Receive the ATQA
1918 if(!ReaderReceive(resp, resp_par)) return 0;
1919
1920 if(p_hi14a_card) {
1921 memcpy(p_hi14a_card->atqa, resp, 2);
1922 p_hi14a_card->uidlen = 0;
1923 memset(p_hi14a_card->uid,0,10);
1924 }
1925
1926 if (anticollision) {
1927 // clear uid
1928 if (uid_ptr) {
1929 memset(uid_ptr,0,10);
1930 }
1931 }
1932
1933 // check for proprietary anticollision:
1934 if ((resp[0] & 0x1F) == 0) {
1935 return 3;
1936 }
1937
1938 // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1939 // which case we need to make a cascade 2 request and select - this is a long UID
1940 // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1941 for(; sak & 0x04; cascade_level++) {
1942 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1943 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1944
1945 if (anticollision) {
1946 // SELECT_ALL
1947 ReaderTransmit(sel_all, sizeof(sel_all), NULL);
1948 if (!ReaderReceive(resp, resp_par)) return 0;
1949
1950 if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit
1951 memset(uid_resp, 0, 4);
1952 uint16_t uid_resp_bits = 0;
1953 uint16_t collision_answer_offset = 0;
1954 // anti-collision-loop:
1955 while (Demod.collisionPos) {
1956 Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1957 for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point
1958 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1959 uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8);
1960 }
1961 uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position
1962 uid_resp_bits++;
1963 // construct anticollosion command:
1964 sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits
1965 for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1966 sel_uid[2+i] = uid_resp[i];
1967 }
1968 collision_answer_offset = uid_resp_bits%8;
1969 ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1970 if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0;
1971 }
1972 // finally, add the last bits and BCC of the UID
1973 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1974 uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1975 uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1976 }
1977
1978 } else { // no collision, use the response to SELECT_ALL as current uid
1979 memcpy(uid_resp, resp, 4);
1980 }
1981 } else {
1982 if (cascade_level < num_cascades - 1) {
1983 uid_resp[0] = 0x88;
1984 memcpy(uid_resp+1, uid_ptr+cascade_level*3, 3);
1985 } else {
1986 memcpy(uid_resp, uid_ptr+cascade_level*3, 4);
1987 }
1988 }
1989 uid_resp_len = 4;
1990
1991 // calculate crypto UID. Always use last 4 Bytes.
1992 if(cuid_ptr) {
1993 *cuid_ptr = bytes_to_num(uid_resp, 4);
1994 }
1995
1996 // Construct SELECT UID command
1997 sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1998 memcpy(sel_uid+2, uid_resp, 4); // the UID received during anticollision, or the provided UID
1999 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC
2000 AppendCrc14443a(sel_uid, 7); // calculate and add CRC
2001 ReaderTransmit(sel_uid, sizeof(sel_uid), NULL);
2002
2003 // Receive the SAK
2004 if (!ReaderReceive(resp, resp_par)) return 0;
2005 sak = resp[0];
2006
2007 // Test if more parts of the uid are coming
2008 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
2009 // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
2010 // http://www.nxp.com/documents/application_note/AN10927.pdf
2011 uid_resp[0] = uid_resp[1];
2012 uid_resp[1] = uid_resp[2];
2013 uid_resp[2] = uid_resp[3];
2014 uid_resp_len = 3;
2015 }
2016
2017 if(uid_ptr && anticollision) {
2018 memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
2019 }
2020
2021 if(p_hi14a_card) {
2022 memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
2023 p_hi14a_card->uidlen += uid_resp_len;
2024 }
2025 }
2026
2027 if(p_hi14a_card) {
2028 p_hi14a_card->sak = sak;
2029 p_hi14a_card->ats_len = 0;
2030 }
2031
2032 // non iso14443a compliant tag
2033 if( (sak & 0x20) == 0) return 2;
2034
2035 // Request for answer to select
2036 AppendCrc14443a(rats, 2);
2037 ReaderTransmit(rats, sizeof(rats), NULL);
2038
2039 if (!(len = ReaderReceive(resp, resp_par))) return 0;
2040
2041
2042 if(p_hi14a_card) {
2043 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
2044 p_hi14a_card->ats_len = len;
2045 }
2046
2047 // reset the PCB block number
2048 iso14_pcb_blocknum = 0;
2049
2050 // set default timeout based on ATS
2051 iso14a_set_ATS_timeout(resp);
2052
2053 return 1;
2054 }
2055
2056 void iso14443a_setup(uint8_t fpga_minor_mode) {
2057 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
2058 // Set up the synchronous serial port
2059 FpgaSetupSsc();
2060 // connect Demodulated Signal to ADC:
2061 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
2062
2063 // Signal field is on with the appropriate LED
2064 if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
2065 || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
2066 LED_D_ON();
2067 } else {
2068 LED_D_OFF();
2069 }
2070 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
2071
2072 // Start the timer
2073 StartCountSspClk();
2074
2075 DemodReset();
2076 UartReset();
2077 NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
2078 iso14a_set_timeout(10*106); // 10ms default
2079 }
2080
2081 int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
2082 uint8_t parity[MAX_PARITY_SIZE];
2083 uint8_t real_cmd[cmd_len+4];
2084 real_cmd[0] = 0x0a; //I-Block
2085 // put block number into the PCB
2086 real_cmd[0] |= iso14_pcb_blocknum;
2087 real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
2088 memcpy(real_cmd+2, cmd, cmd_len);
2089 AppendCrc14443a(real_cmd,cmd_len+2);
2090
2091 ReaderTransmit(real_cmd, cmd_len+4, NULL);
2092 size_t len = ReaderReceive(data, parity);
2093 uint8_t *data_bytes = (uint8_t *) data;
2094 if (!len)
2095 return 0; //DATA LINK ERROR
2096 // if we received an I- or R(ACK)-Block with a block number equal to the
2097 // current block number, toggle the current block number
2098 else if (len >= 4 // PCB+CID+CRC = 4 bytes
2099 && ((data_bytes[0] & 0xC0) == 0 // I-Block
2100 || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
2101 && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
2102 {
2103 iso14_pcb_blocknum ^= 1;
2104 }
2105
2106 return len;
2107 }
2108
2109 //-----------------------------------------------------------------------------
2110 // Read an ISO 14443a tag. Send out commands and store answers.
2111 //
2112 //-----------------------------------------------------------------------------
2113 void ReaderIso14443a(UsbCommand *c)
2114 {
2115 iso14a_command_t param = c->arg[0];
2116 uint8_t *cmd = c->d.asBytes;
2117 size_t len = c->arg[1] & 0xffff;
2118 size_t lenbits = c->arg[1] >> 16;
2119 uint32_t timeout = c->arg[2];
2120 uint32_t arg0 = 0;
2121 byte_t buf[USB_CMD_DATA_SIZE];
2122 uint8_t par[MAX_PARITY_SIZE];
2123
2124 if(param & ISO14A_CONNECT) {
2125 clear_trace();
2126 }
2127
2128 set_tracing(TRUE);
2129
2130 if(param & ISO14A_REQUEST_TRIGGER) {
2131 iso14a_set_trigger(TRUE);
2132 }
2133
2134 if(param & ISO14A_CONNECT) {
2135 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
2136 if(!(param & ISO14A_NO_SELECT)) {
2137 iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
2138 arg0 = iso14443a_select_card(NULL,card,NULL, true, 0);
2139 cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
2140 }
2141 }
2142
2143 if(param & ISO14A_SET_TIMEOUT) {
2144 iso14a_set_timeout(timeout);
2145 }
2146
2147 if(param & ISO14A_APDU) {
2148 arg0 = iso14_apdu(cmd, len, buf);
2149 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2150 }
2151
2152 if(param & ISO14A_RAW) {
2153 if(param & ISO14A_APPEND_CRC) {
2154 if(param & ISO14A_TOPAZMODE) {
2155 AppendCrc14443b(cmd,len);
2156 } else {
2157 AppendCrc14443a(cmd,len);
2158 }
2159 len += 2;
2160 if (lenbits) lenbits += 16;
2161 }
2162 if(lenbits>0) { // want to send a specific number of bits (e.g. short commands)
2163 if(param & ISO14A_TOPAZMODE) {
2164 int bits_to_send = lenbits;
2165 uint16_t i = 0;
2166 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL); // first byte is always short (7bits) and no parity
2167 bits_to_send -= 7;
2168 while (bits_to_send > 0) {
2169 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL); // following bytes are 8 bit and no parity
2170 bits_to_send -= 8;
2171 }
2172 } else {
2173 GetParity(cmd, lenbits/8, par);
2174 ReaderTransmitBitsPar(cmd, lenbits, par, NULL); // bytes are 8 bit with odd parity
2175 }
2176 } else { // want to send complete bytes only
2177 if(param & ISO14A_TOPAZMODE) {
2178 uint16_t i = 0;
2179 ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL); // first byte: 7 bits, no paritiy
2180 while (i < len) {
2181 ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL); // following bytes: 8 bits, no paritiy
2182 }
2183 } else {
2184 ReaderTransmit(cmd,len, NULL); // 8 bits, odd parity
2185 }
2186 }
2187 arg0 = ReaderReceive(buf, par);
2188 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2189 }
2190
2191 if(param & ISO14A_REQUEST_TRIGGER) {
2192 iso14a_set_trigger(FALSE);
2193 }
2194
2195 if(param & ISO14A_NO_DISCONNECT) {
2196 return;
2197 }
2198
2199 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2200 set_tracing(FALSE);
2201 LEDsoff();
2202 }
2203
2204
2205 // Determine the distance between two nonces.
2206 // Assume that the difference is small, but we don't know which is first.
2207 // Therefore try in alternating directions.
2208 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
2209
2210 uint16_t i;
2211 uint32_t nttmp1, nttmp2;
2212
2213 if (nt1 == nt2) return 0;
2214
2215 nttmp1 = nt1;
2216 nttmp2 = nt2;
2217
2218 for (i = 1; i < 0xFFFF; i++) {
2219 nttmp1 = prng_successor(nttmp1, 1);
2220 if (nttmp1 == nt2) return i;
2221 nttmp2 = prng_successor(nttmp2, 1);
2222 if (nttmp2 == nt1) return -i;
2223 }
2224
2225 return(-99999); // either nt1 or nt2 are invalid nonces
2226 }
2227
2228
2229 //-----------------------------------------------------------------------------
2230 // Recover several bits of the cypher stream. This implements (first stages of)
2231 // the algorithm described in "The Dark Side of Security by Obscurity and
2232 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
2233 // (article by Nicolas T. Courtois, 2009)
2234 //-----------------------------------------------------------------------------
2235 void ReaderMifare(bool first_try)
2236 {
2237 // Mifare AUTH
2238 uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b };
2239 uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
2240 static uint8_t mf_nr_ar3;
2241
2242 uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE];
2243 uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE];
2244
2245 if (first_try) {
2246 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2247 }
2248
2249 // free eventually allocated BigBuf memory. We want all for tracing.
2250 BigBuf_free();
2251
2252 clear_trace();
2253 set_tracing(TRUE);
2254
2255 byte_t nt_diff = 0;
2256 uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
2257 static byte_t par_low = 0;
2258 bool led_on = TRUE;
2259 uint8_t uid[10] ={0};
2260 uint32_t cuid;
2261
2262 uint32_t nt = 0;
2263 uint32_t previous_nt = 0;
2264 static uint32_t nt_attacked = 0;
2265 byte_t par_list[8] = {0x00};
2266 byte_t ks_list[8] = {0x00};
2267
2268 #define PRNG_SEQUENCE_LENGTH (1 << 16);
2269 static uint32_t sync_time = 0;
2270 static int32_t sync_cycles = 0;
2271 int catch_up_cycles = 0;
2272 int last_catch_up = 0;
2273 uint16_t elapsed_prng_sequences;
2274 uint16_t consecutive_resyncs = 0;
2275 int isOK = 0;
2276
2277 if (first_try) {
2278 mf_nr_ar3 = 0;
2279 sync_time = GetCountSspClk() & 0xfffffff8;
2280 sync_cycles = PRNG_SEQUENCE_LENGTH; //65536; //0x10000 // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
2281 nt_attacked = 0;
2282 par[0] = 0;
2283 }
2284 else {
2285 // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
2286 mf_nr_ar3++;
2287 mf_nr_ar[3] = mf_nr_ar3;
2288 par[0] = par_low;
2289 }
2290
2291 LED_A_ON();
2292 LED_B_OFF();
2293 LED_C_OFF();
2294
2295
2296 #define MAX_UNEXPECTED_RANDOM 4 // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up.
2297 #define MAX_SYNC_TRIES 32
2298 #define NUM_DEBUG_INFOS 8 // per strategy
2299 #define MAX_STRATEGY 3
2300 uint16_t unexpected_random = 0;
2301 uint16_t sync_tries = 0;
2302 int16_t debug_info_nr = -1;
2303 uint16_t strategy = 0;
2304 int32_t debug_info[MAX_STRATEGY][NUM_DEBUG_INFOS];
2305 uint32_t select_time;
2306 uint32_t halt_time;
2307
2308 for(uint16_t i = 0; TRUE; i++) {
2309
2310 LED_C_ON();
2311 WDT_HIT();
2312
2313 // Test if the action was cancelled
2314 if(BUTTON_PRESS()) {
2315 isOK = -1;
2316 break;
2317 }
2318
2319 if (strategy == 2) {
2320 // test with additional hlt command
2321 halt_time = 0;
2322 int len = mifare_sendcmd_short(NULL, false, 0x50, 0x00, receivedAnswer, receivedAnswerPar, &halt_time);
2323 if (len && MF_DBGLEVEL >= 3) {
2324 Dbprintf("Unexpected response of %d bytes to hlt command (additional debugging).", len);
2325 }
2326 }
2327
2328 if (strategy == 3) {
2329 // test with FPGA power off/on
2330 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2331 SpinDelay(200);
2332 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2333 SpinDelay(100);
2334 }
2335
2336 if(!iso14443a_select_card(uid, NULL, &cuid, true, 0)) {
2337 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
2338 continue;
2339 }
2340 select_time = GetCountSspClk();
2341
2342 elapsed_prng_sequences = 1;
2343 if (debug_info_nr == -1) {
2344 sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
2345 catch_up_cycles = 0;
2346
2347 // if we missed the sync time already, advance to the next nonce repeat
2348 while(GetCountSspClk() > sync_time) {
2349 elapsed_prng_sequences++;
2350 sync_time = (sync_time & 0xfffffff8) + sync_cycles;
2351 }
2352
2353 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2354 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2355 } else {
2356 // collect some information on tag nonces for debugging:
2357 #define DEBUG_FIXED_SYNC_CYCLES PRNG_SEQUENCE_LENGTH
2358 if (strategy == 0) {
2359 // nonce distances at fixed time after card select:
2360 sync_time = select_time + DEBUG_FIXED_SYNC_CYCLES;
2361 } else if (strategy == 1) {
2362 // nonce distances at fixed time between authentications:
2363 sync_time = sync_time + DEBUG_FIXED_SYNC_CYCLES;
2364 } else if (strategy == 2) {
2365 // nonce distances at fixed time after halt:
2366 sync_time = halt_time + DEBUG_FIXED_SYNC_CYCLES;
2367 } else {
2368 // nonce_distances at fixed time after power on
2369 sync_time = DEBUG_FIXED_SYNC_CYCLES;
2370 }
2371 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2372 }
2373
2374 // Receive the (4 Byte) "random" nonce
2375 if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2376 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce");
2377 continue;
2378 }
2379
2380 previous_nt = nt;
2381 nt = bytes_to_num(receivedAnswer, 4);
2382
2383 // Transmit reader nonce with fake par
2384 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2385
2386 if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
2387 int nt_distance = dist_nt(previous_nt, nt);
2388 if (nt_distance == 0) {
2389 nt_attacked = nt;
2390 } else {
2391 if (nt_distance == -99999) { // invalid nonce received
2392 unexpected_random++;
2393 if (unexpected_random > MAX_UNEXPECTED_RANDOM) {
2394 isOK = -3; // Card has an unpredictable PRNG. Give up
2395 break;
2396 } else {
2397 continue; // continue trying...
2398 }
2399 }
2400 if (++sync_tries > MAX_SYNC_TRIES) {
2401 if (strategy > MAX_STRATEGY || MF_DBGLEVEL < 3) {
2402 isOK = -4; // Card's PRNG runs at an unexpected frequency or resets unexpectedly
2403 break;
2404 } else { // continue for a while, just to collect some debug info
2405 debug_info[strategy][debug_info_nr] = nt_distance;
2406 debug_info_nr++;
2407 if (debug_info_nr == NUM_DEBUG_INFOS) {
2408 strategy++;
2409 debug_info_nr = 0;
2410 }
2411 continue;
2412 }
2413 }
2414 sync_cycles = (sync_cycles - nt_distance/elapsed_prng_sequences);
2415 if (sync_cycles <= 0) {
2416 sync_cycles += PRNG_SEQUENCE_LENGTH;
2417 }
2418 if (MF_DBGLEVEL >= 3) {
2419 Dbprintf("calibrating in cycle %d. nt_distance=%d, elapsed_prng_sequences=%d, new sync_cycles: %d\n", i, nt_distance, elapsed_prng_sequences, sync_cycles);
2420 }
2421 continue;
2422 }
2423 }
2424
2425 if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
2426 catch_up_cycles = -dist_nt(nt_attacked, nt);
2427 if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one.
2428 catch_up_cycles = 0;
2429 continue;
2430 }
2431 catch_up_cycles /= elapsed_prng_sequences;
2432 if (catch_up_cycles == last_catch_up) {
2433 consecutive_resyncs++;
2434 }
2435 else {
2436 last_catch_up = catch_up_cycles;
2437 consecutive_resyncs = 0;
2438 }
2439 if (consecutive_resyncs < 3) {
2440 if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, -catch_up_cycles, consecutive_resyncs);
2441 }
2442 else {
2443 sync_cycles = sync_cycles + catch_up_cycles;
2444 if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d for the fourth time consecutively (nt_distance = %d). Adjusting sync_cycles to %d.\n", i, -catch_up_cycles, sync_cycles);
2445 last_catch_up = 0;
2446 catch_up_cycles = 0;
2447 consecutive_resyncs = 0;
2448 }
2449 continue;
2450 }
2451
2452 consecutive_resyncs = 0;
2453
2454 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2455 if (ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2456 catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2457
2458 if (nt_diff == 0) {
2459 par_low = par[0] & 0xE0; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change
2460 }
2461
2462 led_on = !led_on;
2463 if(led_on) LED_B_ON(); else LED_B_OFF();
2464
2465 par_list[nt_diff] = SwapBits(par[0], 8);
2466 ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
2467
2468 // Test if the information is complete
2469 if (nt_diff == 0x07) {
2470 isOK = 1;
2471 break;
2472 }
2473
2474 nt_diff = (nt_diff + 1) & 0x07;
2475 mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2476 par[0] = par_low;
2477 } else {
2478 if (nt_diff == 0 && first_try)
2479 {
2480 par[0]++;
2481 if (par[0] == 0x00) { // tried all 256 possible parities without success. Card doesn't send NACK.
2482 isOK = -2;
2483 break;
2484 }
2485 } else {
2486 par[0] = ((par[0] & 0x1F) + 1) | par_low;
2487 }
2488 }
2489 }
2490
2491
2492 mf_nr_ar[3] &= 0x1F;
2493
2494 if (isOK == -4) {
2495 if (MF_DBGLEVEL >= 3) {
2496 for (uint16_t i = 0; i <= MAX_STRATEGY; i++) {
2497 for(uint16_t j = 0; j < NUM_DEBUG_INFOS; j++) {
2498 Dbprintf("collected debug info[%d][%d] = %d", i, j, debug_info[i][j]);
2499 }
2500 }
2501 }
2502 }
2503
2504 byte_t buf[28];
2505 memcpy(buf + 0, uid, 4);
2506 num_to_bytes(nt, 4, buf + 4);
2507 memcpy(buf + 8, par_list, 8);
2508 memcpy(buf + 16, ks_list, 8);
2509 memcpy(buf + 24, mf_nr_ar, 4);
2510
2511 cmd_send(CMD_ACK,isOK,0,0,buf,28);
2512
2513 // Thats it...
2514 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2515 LEDsoff();
2516
2517 set_tracing(FALSE);
2518 }
2519
2520 /**
2521 *MIFARE 1K simulate.
2522 *
2523 *@param flags :
2524 * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2525 * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
2526 * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
2527 * FLAG_NR_AR_ATTACK - means we should collect NR_AR responses for bruteforcing later
2528 *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2529 */
2530 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
2531 {
2532 int cardSTATE = MFEMUL_NOFIELD;
2533 int _7BUID = 0;
2534 int vHf = 0; // in mV
2535 int res;
2536 uint32_t selTimer = 0;
2537 uint32_t authTimer = 0;
2538 uint16_t len = 0;
2539 uint8_t cardWRBL = 0;
2540 uint8_t cardAUTHSC = 0;
2541 uint8_t cardAUTHKEY = 0xff; // no authentication
2542 // uint32_t cardRr = 0;
2543 uint32_t cuid = 0;
2544 //uint32_t rn_enc = 0;
2545 uint32_t ans = 0;
2546 uint32_t cardINTREG = 0;
2547 uint8_t cardINTBLOCK = 0;
2548 struct Crypto1State mpcs = {0, 0};
2549 struct Crypto1State *pcs;
2550 pcs = &mpcs;
2551 uint32_t numReads = 0;//Counts numer of times reader read a block
2552 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
2553 uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE];
2554 uint8_t response[MAX_MIFARE_FRAME_SIZE];
2555 uint8_t response_par[MAX_MIFARE_PARITY_SIZE];
2556
2557 uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
2558 uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2559 uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
2560 uint8_t rSAK[] = {0x08, 0xb6, 0xdd}; // Mifare Classic
2561 //uint8_t rSAK[] = {0x09, 0x3f, 0xcc }; // Mifare Mini
2562 uint8_t rSAK1[] = {0x04, 0xda, 0x17};
2563
2564 uint8_t rAUTH_NT[] = {0x01, 0x01, 0x01, 0x01};
2565 uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2566
2567 //Here, we collect UID1,UID2,NT,AR,NR,0,0,NT2,AR2,NR2
2568 // This can be used in a reader-only attack.
2569 // (it can also be retrieved via 'hf 14a list', but hey...
2570 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0,0,0};
2571 uint8_t ar_nr_collected = 0;
2572
2573 // Authenticate response - nonce
2574 uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2575
2576 //-- Determine the UID
2577 // Can be set from emulator memory, incoming data
2578 // and can be 7 or 4 bytes long
2579 if (flags & FLAG_4B_UID_IN_DATA)
2580 {
2581 // 4B uid comes from data-portion of packet
2582 memcpy(rUIDBCC1,datain,4);
2583 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2584
2585 } else if (flags & FLAG_7B_UID_IN_DATA) {
2586 // 7B uid comes from data-portion of packet
2587 memcpy(&rUIDBCC1[1],datain,3);
2588 memcpy(rUIDBCC2, datain+3, 4);
2589 _7BUID = true;
2590 } else {
2591 // get UID from emul memory
2592 emlGetMemBt(receivedCmd, 7, 1);
2593 _7BUID = !(receivedCmd[0] == 0x00);
2594 if (!_7BUID) { // ---------- 4BUID
2595 emlGetMemBt(rUIDBCC1, 0, 4);
2596 } else { // ---------- 7BUID
2597 emlGetMemBt(&rUIDBCC1[1], 0, 3);
2598 emlGetMemBt(rUIDBCC2, 3, 4);
2599 }
2600 }
2601
2602 // save uid.
2603 ar_nr_responses[0*5] = bytes_to_num(rUIDBCC1+1, 3);
2604 if ( _7BUID )
2605 ar_nr_responses[0*5+1] = bytes_to_num(rUIDBCC2, 4);
2606
2607 /*
2608 * Regardless of what method was used to set the UID, set fifth byte and modify
2609 * the ATQA for 4 or 7-byte UID
2610 */
2611 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2612 if (_7BUID) {
2613 rATQA[0] = 0x44;
2614 rUIDBCC1[0] = 0x88;
2615 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2616 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2617 }
2618
2619 if (MF_DBGLEVEL >= 1) {
2620 if (!_7BUID) {
2621 Dbprintf("4B UID: %02x%02x%02x%02x",
2622 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3]);
2623 } else {
2624 Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",
2625 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3],
2626 rUIDBCC2[0], rUIDBCC2[1] ,rUIDBCC2[2], rUIDBCC2[3]);
2627 }
2628 }
2629
2630 // We need to listen to the high-frequency, peak-detected path.
2631 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2632
2633 // free eventually allocated BigBuf memory but keep Emulator Memory
2634 BigBuf_free_keep_EM();
2635
2636 // clear trace
2637 clear_trace();
2638 set_tracing(TRUE);
2639
2640
2641 bool finished = FALSE;
2642 while (!BUTTON_PRESS() && !finished && !usb_poll_validate_length()) {
2643 WDT_HIT();
2644
2645 // find reader field
2646 if (cardSTATE == MFEMUL_NOFIELD) {
2647 vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
2648 if (vHf > MF_MINFIELDV) {
2649 cardSTATE_TO_IDLE();
2650 LED_A_ON();
2651 }
2652 }
2653 if(cardSTATE == MFEMUL_NOFIELD) continue;
2654
2655 //Now, get data
2656 res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
2657 if (res == 2) { //Field is off!
2658 cardSTATE = MFEMUL_NOFIELD;
2659 LEDsoff();
2660 continue;
2661 } else if (res == 1) {
2662 break; //return value 1 means button press
2663 }
2664
2665 // REQ or WUP request in ANY state and WUP in HALTED state
2666 if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
2667 selTimer = GetTickCount();
2668 EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
2669 cardSTATE = MFEMUL_SELECT1;
2670
2671 // init crypto block
2672 LED_B_OFF();
2673 LED_C_OFF();
2674 crypto1_destroy(pcs);
2675 cardAUTHKEY = 0xff;
2676 continue;
2677 }
2678
2679 switch (cardSTATE) {
2680 case MFEMUL_NOFIELD:
2681 case MFEMUL_HALTED:
2682 case MFEMUL_IDLE:{
2683 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2684 break;
2685 }
2686 case MFEMUL_SELECT1:{
2687 // select all
2688 if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
2689 if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received");
2690 EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2691 break;
2692 }
2693
2694 if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
2695 {
2696 Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
2697 }
2698 // select card
2699 if (len == 9 &&
2700 (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2701 EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK));
2702 cuid = bytes_to_num(rUIDBCC1, 4);
2703 if (!_7BUID) {
2704 cardSTATE = MFEMUL_WORK;
2705 LED_B_ON();
2706 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2707 break;
2708 } else {
2709 cardSTATE = MFEMUL_SELECT2;
2710 }
2711 }
2712 break;
2713 }
2714 case MFEMUL_AUTH1:{
2715 if( len != 8)
2716 {
2717 cardSTATE_TO_IDLE();
2718 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2719 break;
2720 }
2721
2722 uint32_t ar = bytes_to_num(receivedCmd, 4);
2723 uint32_t nr = bytes_to_num(&receivedCmd[4], 4);
2724
2725 //Collect AR/NR
2726 //if(ar_nr_collected < 2 && cardAUTHSC == 2){
2727 if(ar_nr_collected < 2){
2728 if(ar_nr_responses[2] != ar)
2729 {// Avoid duplicates... probably not necessary, ar should vary.
2730 //ar_nr_responses[ar_nr_collected*5] = 0;
2731 //ar_nr_responses[ar_nr_collected*5+1] = 0;
2732 ar_nr_responses[ar_nr_collected*5+2] = nonce;
2733 ar_nr_responses[ar_nr_collected*5+3] = nr;
2734 ar_nr_responses[ar_nr_collected*5+4] = ar;
2735 ar_nr_collected++;
2736 }
2737 // Interactive mode flag, means we need to send ACK
2738 if(flags & FLAG_INTERACTIVE && ar_nr_collected == 2)
2739 {
2740 finished = true;
2741 }
2742 }
2743
2744 // --- crypto
2745 //crypto1_word(pcs, ar , 1);
2746 //cardRr = nr ^ crypto1_word(pcs, 0, 0);
2747
2748 //test if auth OK
2749 //if (cardRr != prng_successor(nonce, 64)){
2750
2751 //if (MF_DBGLEVEL >= 4) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
2752 // cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2753 // cardRr, prng_successor(nonce, 64));
2754 // Shouldn't we respond anything here?
2755 // Right now, we don't nack or anything, which causes the
2756 // reader to do a WUPA after a while. /Martin
2757 // -- which is the correct response. /piwi
2758 //cardSTATE_TO_IDLE();
2759 //LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2760 //break;
2761 //}
2762
2763 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2764
2765 num_to_bytes(ans, 4, rAUTH_AT);
2766 // --- crypto
2767 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2768 LED_C_ON();
2769 cardSTATE = MFEMUL_WORK;
2770 if (MF_DBGLEVEL >= 4) Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2771 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2772 GetTickCount() - authTimer);
2773 break;
2774 }
2775 case MFEMUL_SELECT2:{
2776 if (!len) {
2777 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2778 break;
2779 }
2780 if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
2781 EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2782 break;
2783 }
2784
2785 // select 2 card
2786 if (len == 9 &&
2787 (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
2788 EmSendCmd(rSAK, sizeof(rSAK));
2789 cuid = bytes_to_num(rUIDBCC2, 4);
2790 cardSTATE = MFEMUL_WORK;
2791 LED_B_ON();
2792 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2793 break;
2794 }
2795
2796 // i guess there is a command). go into the work state.
2797 if (len != 4) {
2798 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2799 break;
2800 }
2801 cardSTATE = MFEMUL_WORK;
2802 //goto lbWORK;
2803 //intentional fall-through to the next case-stmt
2804 }
2805
2806 case MFEMUL_WORK:{
2807 if (len == 0) {
2808 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2809 break;
2810 }
2811
2812 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2813
2814 if(encrypted_data) {
2815 // decrypt seqence
2816 mf_crypto1_decrypt(pcs, receivedCmd, len);
2817 }
2818
2819 if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
2820 authTimer = GetTickCount();
2821 cardAUTHSC = receivedCmd[1] / 4; // received block num
2822 cardAUTHKEY = receivedCmd[0] - 0x60;
2823 crypto1_destroy(pcs);//Added by martin
2824 crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2825
2826 if (!encrypted_data) { // first authentication
2827 if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2828
2829 crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
2830 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2831 } else { // nested authentication
2832 if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2833 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2834 num_to_bytes(ans, 4, rAUTH_AT);
2835 }
2836
2837 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2838 //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
2839 cardSTATE = MFEMUL_AUTH1;
2840 break;
2841 }
2842
2843 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2844 // BUT... ACK --> NACK
2845 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2846 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2847 break;
2848 }
2849
2850 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2851 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2852 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2853 break;
2854 }
2855
2856 if(len != 4) {
2857 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2858 break;
2859 }
2860
2861 if(receivedCmd[0] == 0x30 // read block
2862 || receivedCmd[0] == 0xA0 // write block
2863 || receivedCmd[0] == 0xC0 // inc
2864 || receivedCmd[0] == 0xC1 // dec
2865 || receivedCmd[0] == 0xC2 // restore
2866 || receivedCmd[0] == 0xB0) { // transfer
2867 if (receivedCmd[1] >= 16 * 4) {
2868 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2869 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate (0x%02) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2870 break;
2871 }
2872
2873 if (receivedCmd[1] / 4 != cardAUTHSC) {
2874 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2875 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate (0x%02) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
2876 break;
2877 }
2878 }
2879 // read block
2880 if (receivedCmd[0] == 0x30) {
2881 if (MF_DBGLEVEL >= 4) {
2882 Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
2883 }
2884 emlGetMem(response, receivedCmd[1], 1);
2885 AppendCrc14443a(response, 16);
2886 mf_crypto1_encrypt(pcs, response, 18, response_par);
2887 EmSendCmdPar(response, 18, response_par);
2888 numReads++;
2889 if(exitAfterNReads > 0 && numReads >= exitAfterNReads) {
2890 Dbprintf("%d reads done, exiting", numReads);
2891 finished = true;
2892 }
2893 break;
2894 }
2895 // write block
2896 if (receivedCmd[0] == 0xA0) {
2897 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
2898 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2899 cardSTATE = MFEMUL_WRITEBL2;
2900 cardWRBL = receivedCmd[1];
2901 break;
2902 }
2903 // increment, decrement, restore
2904 if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
2905 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2906 if (emlCheckValBl(receivedCmd[1])) {
2907 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2908 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2909 break;
2910 }
2911 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2912 if (receivedCmd[0] == 0xC1)
2913 cardSTATE = MFEMUL_INTREG_INC;
2914 if (receivedCmd[0] == 0xC0)
2915 cardSTATE = MFEMUL_INTREG_DEC;
2916 if (receivedCmd[0] == 0xC2)
2917 cardSTATE = MFEMUL_INTREG_REST;
2918 cardWRBL = receivedCmd[1];
2919 break;
2920 }
2921 // transfer
2922 if (receivedCmd[0] == 0xB0) {
2923 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2924 if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2925 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2926 else
2927 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2928 break;
2929 }
2930 // halt
2931 if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
2932 LED_B_OFF();
2933 LED_C_OFF();
2934 cardSTATE = MFEMUL_HALTED;
2935 if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer);
2936 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2937 break;
2938 }
2939 // RATS
2940 if (receivedCmd[0] == 0xe0) {//RATS
2941 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2942 break;
2943 }
2944 // command not allowed
2945 if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking");
2946 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2947 break;
2948 }
2949 case MFEMUL_WRITEBL2:{
2950 if (len == 18){
2951 mf_crypto1_decrypt(pcs, receivedCmd, len);
2952 emlSetMem(receivedCmd, cardWRBL, 1);
2953 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2954 cardSTATE = MFEMUL_WORK;
2955 } else {
2956 cardSTATE_TO_IDLE();
2957 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2958 }
2959 break;
2960 }
2961
2962 case MFEMUL_INTREG_INC:{
2963 mf_crypto1_decrypt(pcs, receivedCmd, len);
2964 memcpy(&ans, receivedCmd, 4);
2965 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2966 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2967 cardSTATE_TO_IDLE();
2968 break;
2969 }
2970 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2971 cardINTREG = cardINTREG + ans;
2972 cardSTATE = MFEMUL_WORK;
2973 break;
2974 }
2975 case MFEMUL_INTREG_DEC:{
2976 mf_crypto1_decrypt(pcs, receivedCmd, len);
2977 memcpy(&ans, receivedCmd, 4);
2978 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2979 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2980 cardSTATE_TO_IDLE();
2981 break;
2982 }
2983 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2984 cardINTREG = cardINTREG - ans;
2985 cardSTATE = MFEMUL_WORK;
2986 break;
2987 }
2988 case MFEMUL_INTREG_REST:{
2989 mf_crypto1_decrypt(pcs, receivedCmd, len);
2990 memcpy(&ans, receivedCmd, 4);
2991 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2992 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2993 cardSTATE_TO_IDLE();
2994 break;
2995 }
2996 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2997 cardSTATE = MFEMUL_WORK;
2998 break;
2999 }
3000 }
3001 }
3002
3003 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
3004 LEDsoff();
3005
3006 if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
3007 {
3008 //May just aswell send the collected ar_nr in the response aswell
3009 uint8_t len = ar_nr_collected*5*4;
3010 cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, len, 0, &ar_nr_responses, len);
3011 }
3012
3013 if(flags & FLAG_NR_AR_ATTACK && MF_DBGLEVEL >= 1 )
3014 {
3015 if(ar_nr_collected > 1 ) {
3016 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
3017 Dbprintf("../tools/mfkey/mfkey32 %06x%08x %08x %08x %08x %08x %08x",
3018 ar_nr_responses[0], // UID1
3019 ar_nr_responses[1], // UID2
3020 ar_nr_responses[2], // NT
3021 ar_nr_responses[3], // AR1
3022 ar_nr_responses[4], // NR1
3023 ar_nr_responses[8], // AR2
3024 ar_nr_responses[9] // NR2
3025 );
3026 Dbprintf("../tools/mfkey/mfkey32v2 %06x%08x %08x %08x %08x %08x %08x %08x",
3027 ar_nr_responses[0], // UID1
3028 ar_nr_responses[1], // UID2
3029 ar_nr_responses[2], // NT1
3030 ar_nr_responses[3], // AR1
3031 ar_nr_responses[4], // NR1
3032 ar_nr_responses[7], // NT2
3033 ar_nr_responses[8], // AR2
3034 ar_nr_responses[9] // NR2
3035 );
3036 } else {
3037 Dbprintf("Failed to obtain two AR/NR pairs!");
3038 if(ar_nr_collected > 0 ) {
3039 Dbprintf("Only got these: UID=%06x%08x, nonce=%08x, AR1=%08x, NR1=%08x",
3040 ar_nr_responses[0], // UID1
3041 ar_nr_responses[1], // UID2
3042 ar_nr_responses[2], // NT
3043 ar_nr_responses[3], // AR1
3044 ar_nr_responses[4] // NR1
3045 );
3046 }
3047 }
3048 }
3049 if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen());
3050
3051 set_tracing(FALSE);
3052 }
3053
3054
3055 //-----------------------------------------------------------------------------
3056 // MIFARE sniffer.
3057 //
3058 //-----------------------------------------------------------------------------
3059 void RAMFUNC SniffMifare(uint8_t param) {
3060 // param:
3061 // bit 0 - trigger from first card answer
3062 // bit 1 - trigger from first reader 7-bit request
3063
3064 // C(red) A(yellow) B(green)
3065 LEDsoff();
3066 // init trace buffer
3067 clear_trace();
3068 set_tracing(TRUE);
3069
3070 // The command (reader -> tag) that we're receiving.
3071 // The length of a received command will in most cases be no more than 18 bytes.
3072 // So 32 should be enough!
3073 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
3074 uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE];
3075 // The response (tag -> reader) that we're receiving.
3076 uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE];
3077 uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE];
3078
3079 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
3080
3081 // free eventually allocated BigBuf memory
3082 BigBuf_free();
3083 // allocate the DMA buffer, used to stream samples from the FPGA
3084 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
3085 uint8_t *data = dmaBuf;
3086 uint8_t previous_data = 0;
3087 int maxDataLen = 0;
3088 int dataLen = 0;
3089 bool ReaderIsActive = FALSE;
3090 bool TagIsActive = FALSE;
3091
3092 // Set up the demodulator for tag -> reader responses.
3093 DemodInit(receivedResponse, receivedResponsePar);
3094
3095 // Set up the demodulator for the reader -> tag commands
3096 UartInit(receivedCmd, receivedCmdPar);
3097
3098 // Setup for the DMA.
3099 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
3100
3101 LED_D_OFF();
3102
3103 // init sniffer
3104 MfSniffInit();
3105
3106 // And now we loop, receiving samples.
3107 for(uint32_t sniffCounter = 0; TRUE; ) {
3108
3109 if(BUTTON_PRESS()) {
3110 DbpString("cancelled by button");
3111 break;
3112 }
3113
3114 LED_A_ON();
3115 WDT_HIT();
3116
3117 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
3118 // check if a transaction is completed (timeout after 2000ms).
3119 // if yes, stop the DMA transfer and send what we have so far to the client
3120 if (MfSniffSend(2000)) {
3121 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
3122 sniffCounter = 0;
3123 data = dmaBuf;
3124 maxDataLen = 0;
3125 ReaderIsActive = FALSE;
3126 TagIsActive = FALSE;
3127 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
3128 }
3129 }
3130
3131 int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
3132 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
3133 if (readBufDataP <= dmaBufDataP){ // we are processing the same block of data which is currently being transferred
3134 dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
3135 } else {
3136 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
3137 }
3138 // test for length of buffer
3139 if(dataLen > maxDataLen) { // we are more behind than ever...
3140 maxDataLen = dataLen;
3141 if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
3142 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
3143 break;
3144 }
3145 }
3146 if(dataLen < 1) continue;
3147
3148 // primary buffer was stopped ( <-- we lost data!
3149 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
3150 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
3151 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
3152 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
3153 }
3154 // secondary buffer sets as primary, secondary buffer was stopped
3155 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
3156 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
3157 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
3158 }
3159
3160 LED_A_OFF();
3161
3162 if (sniffCounter & 0x01) {
3163
3164 if(!TagIsActive) { // no need to try decoding tag data if the reader is sending
3165 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
3166 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
3167 LED_C_INV();
3168 if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
3169
3170 /* And ready to receive another command. */
3171 UartInit(receivedCmd, receivedCmdPar);
3172
3173 /* And also reset the demod code */
3174 DemodReset();
3175 }
3176 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
3177 }
3178
3179 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending
3180 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
3181 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
3182 LED_C_INV();
3183
3184 if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
3185
3186 // And ready to receive another response.
3187 DemodReset();
3188 // And reset the Miller decoder including its (now outdated) input buffer
3189 UartInit(receivedCmd, receivedCmdPar);
3190 }
3191 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
3192 }
3193 }
3194
3195 previous_data = *data;
3196 sniffCounter++;
3197 data++;
3198 if(data == dmaBuf + DMA_BUFFER_SIZE) {
3199 data = dmaBuf;
3200 }
3201
3202 } // main cycle
3203
3204 FpgaDisableSscDma();
3205 MfSniffEnd();
3206 LEDsoff();
3207 Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
3208 set_tracing(FALSE);
3209 }
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