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FIX: antenna was not turn off after "hf 14b write" command. The method is using...
[proxmark3-svn] / armsrc / iso14443a.c
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 "../include/proxmark3.h"
14 #include "apps.h"
15 #include "util.h"
16 #include "string.h"
17 #include "../common/cmd.h"
18 #include "../common/iso14443crc.h"
19 #include "iso14443a.h"
20 #include "crapto1.h"
21 #include "mifareutil.h"
22
23 static uint32_t iso14a_timeout;
24 uint8_t *trace = (uint8_t *) BigBuf+TRACE_OFFSET;
25 int rsamples = 0;
26 int traceLen = 0;
27 int tracing = TRUE;
28 uint8_t trigger = 0;
29 // the block number for the ISO14443-4 PCB
30 static uint8_t iso14_pcb_blocknum = 0;
31
32 //
33 // ISO14443 timing:
34 //
35 // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
36 #define REQUEST_GUARD_TIME (7000/16 + 1)
37 // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
38 #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
39 // bool LastCommandWasRequest = FALSE;
40
41 //
42 // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
43 //
44 // When the PM acts as reader and is receiving tag data, it takes
45 // 3 ticks delay in the AD converter
46 // 16 ticks until the modulation detector completes and sets curbit
47 // 8 ticks until bit_to_arm is assigned from curbit
48 // 8*16 ticks for the transfer from FPGA to ARM
49 // 4*16 ticks until we measure the time
50 // - 8*16 ticks because we measure the time of the previous transfer
51 #define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
52
53 // When the PM acts as a reader and is sending, it takes
54 // 4*16 ticks until we can write data to the sending hold register
55 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
56 // 8 ticks until the first transfer starts
57 // 8 ticks later the FPGA samples the data
58 // 1 tick to assign mod_sig_coil
59 #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
60
61 // When the PM acts as tag and is receiving it takes
62 // 2 ticks delay in the RF part (for the first falling edge),
63 // 3 ticks for the A/D conversion,
64 // 8 ticks on average until the start of the SSC transfer,
65 // 8 ticks until the SSC samples the first data
66 // 7*16 ticks to complete the transfer from FPGA to ARM
67 // 8 ticks until the next ssp_clk rising edge
68 // 4*16 ticks until we measure the time
69 // - 8*16 ticks because we measure the time of the previous transfer
70 #define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
71
72 // The FPGA will report its internal sending delay in
73 uint16_t FpgaSendQueueDelay;
74 // the 5 first bits are the number of bits buffered in mod_sig_buf
75 // the last three bits are the remaining ticks/2 after the mod_sig_buf shift
76 #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
77
78 // When the PM acts as tag and is sending, it takes
79 // 4*16 ticks until we can write data to the sending hold register
80 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
81 // 8 ticks until the first transfer starts
82 // 8 ticks later the FPGA samples the data
83 // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
84 // + 1 tick to assign mod_sig_coil
85 #define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
86
87 // When the PM acts as sniffer and is receiving tag data, it takes
88 // 3 ticks A/D conversion
89 // 14 ticks to complete the modulation detection
90 // 8 ticks (on average) until the result is stored in to_arm
91 // + the delays in transferring data - which is the same for
92 // sniffing reader and tag data and therefore not relevant
93 #define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
94
95 // When the PM acts as sniffer and is receiving reader data, it takes
96 // 2 ticks delay in analogue RF receiver (for the falling edge of the
97 // start bit, which marks the start of the communication)
98 // 3 ticks A/D conversion
99 // 8 ticks on average until the data is stored in to_arm.
100 // + the delays in transferring data - which is the same for
101 // sniffing reader and tag data and therefore not relevant
102 #define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
103
104 //variables used for timing purposes:
105 //these are in ssp_clk cycles:
106 static uint32_t NextTransferTime;
107 static uint32_t LastTimeProxToAirStart;
108 static uint32_t LastProxToAirDuration;
109
110
111
112 // CARD TO READER - manchester
113 // Sequence D: 11110000 modulation with subcarrier during first half
114 // Sequence E: 00001111 modulation with subcarrier during second half
115 // Sequence F: 00000000 no modulation with subcarrier
116 // READER TO CARD - miller
117 // Sequence X: 00001100 drop after half a period
118 // Sequence Y: 00000000 no drop
119 // Sequence Z: 11000000 drop at start
120 #define SEC_D 0xf0
121 #define SEC_E 0x0f
122 #define SEC_F 0x00
123 #define SEC_X 0x0c
124 #define SEC_Y 0x00
125 #define SEC_Z 0xc0
126
127 const uint8_t OddByteParity[256] = {
128 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
129 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
130 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
131 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
132 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
133 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
134 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
135 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
136 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
137 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
138 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
139 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
140 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
141 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
142 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
143 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1
144 };
145
146 void iso14a_set_trigger(bool enable) {
147 trigger = enable;
148 }
149
150 void iso14a_clear_trace() {
151 memset(trace, 0x44, TRACE_SIZE);
152 traceLen = 0;
153 }
154
155 void iso14a_set_tracing(bool enable) {
156 tracing = enable;
157 }
158
159 void iso14a_set_timeout(uint32_t timeout) {
160 iso14a_timeout = timeout;
161 }
162
163 //-----------------------------------------------------------------------------
164 // Generate the parity value for a byte sequence
165 //
166 //-----------------------------------------------------------------------------
167 byte_t oddparity (const byte_t bt)
168 {
169 return OddByteParity[bt];
170 }
171
172 void GetParity(const uint8_t * pbtCmd, uint16_t iLen, uint8_t *par)
173 {
174 uint16_t paritybit_cnt = 0;
175 uint16_t paritybyte_cnt = 0;
176 uint8_t parityBits = 0;
177
178 for (uint16_t i = 0; i < iLen; i++) {
179 // Generate the parity bits
180 parityBits |= ((OddByteParity[pbtCmd[i]]) << (7-paritybit_cnt));
181 if (paritybit_cnt == 7) {
182 par[paritybyte_cnt] = parityBits; // save 8 Bits parity
183 parityBits = 0; // and advance to next Parity Byte
184 paritybyte_cnt++;
185 paritybit_cnt = 0;
186 } else {
187 paritybit_cnt++;
188 }
189 }
190
191 // save remaining parity bits
192 par[paritybyte_cnt] = parityBits;
193
194 }
195
196 void AppendCrc14443a(uint8_t* data, int len)
197 {
198 ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
199 }
200
201 // The function LogTrace() is also used by the iClass implementation in iClass.c
202 bool RAMFUNC LogTrace(const uint8_t *btBytes, uint16_t iLen, uint32_t timestamp_start, uint32_t timestamp_end, uint8_t *parity, bool readerToTag)
203 {
204 if (!tracing) return FALSE;
205
206 uint16_t num_paritybytes = (iLen-1)/8 + 1; // number of valid paritybytes in *parity
207 uint16_t duration = timestamp_end - timestamp_start;
208
209 // Return when trace is full
210 if (traceLen + sizeof(iLen) + sizeof(timestamp_start) + sizeof(duration) + num_paritybytes + iLen >= TRACE_SIZE) {
211 tracing = FALSE; // don't trace any more
212 return FALSE;
213 }
214
215 // Traceformat:
216 // 32 bits timestamp (little endian)
217 // 16 bits duration (little endian)
218 // 16 bits data length (little endian, Highest Bit used as readerToTag flag)
219 // y Bytes data
220 // x Bytes parity (one byte per 8 bytes data)
221
222 // timestamp (start)
223 trace[traceLen++] = ((timestamp_start >> 0) & 0xff);
224 trace[traceLen++] = ((timestamp_start >> 8) & 0xff);
225 trace[traceLen++] = ((timestamp_start >> 16) & 0xff);
226 trace[traceLen++] = ((timestamp_start >> 24) & 0xff);
227
228 // duration
229 trace[traceLen++] = ((duration >> 0) & 0xff);
230 trace[traceLen++] = ((duration >> 8) & 0xff);
231
232 // data length
233 trace[traceLen++] = ((iLen >> 0) & 0xff);
234 trace[traceLen++] = ((iLen >> 8) & 0xff);
235
236 // readerToTag flag
237 if (!readerToTag) {
238 trace[traceLen - 1] |= 0x80;
239 }
240
241 // data bytes
242 if (btBytes != NULL && iLen != 0) {
243 memcpy(trace + traceLen, btBytes, iLen);
244 }
245 traceLen += iLen;
246
247 // parity bytes
248 if (parity != NULL && iLen != 0) {
249 memcpy(trace + traceLen, parity, num_paritybytes);
250 }
251 traceLen += num_paritybytes;
252
253 return TRUE;
254 }
255
256 //=============================================================================
257 // ISO 14443 Type A - Miller decoder
258 //=============================================================================
259 // Basics:
260 // This decoder is used when the PM3 acts as a tag.
261 // The reader will generate "pauses" by temporarily switching of the field.
262 // At the PM3 antenna we will therefore measure a modulated antenna voltage.
263 // The FPGA does a comparison with a threshold and would deliver e.g.:
264 // ........ 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 .......
265 // The Miller decoder needs to identify the following sequences:
266 // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0")
267 // 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information")
268 // 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1")
269 // Note 1: the bitstream may start at any time. We therefore need to sync.
270 // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
271 //-----------------------------------------------------------------------------
272 static tUart Uart;
273
274 // Lookup-Table to decide if 4 raw bits are a modulation.
275 // We accept two or three consecutive "0" in any position with the rest "1"
276 const bool Mod_Miller_LUT[] = {
277 TRUE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, FALSE,
278 TRUE, TRUE, FALSE, FALSE, TRUE, FALSE, FALSE, FALSE
279 };
280 #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x00F0) >> 4])
281 #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x000F)])
282
283 void UartReset()
284 {
285 Uart.state = STATE_UNSYNCD;
286 Uart.bitCount = 0;
287 Uart.len = 0; // number of decoded data bytes
288 Uart.parityLen = 0; // number of decoded parity bytes
289 Uart.shiftReg = 0; // shiftreg to hold decoded data bits
290 Uart.parityBits = 0; // holds 8 parity bits
291 Uart.twoBits = 0x0000; // buffer for 2 Bits
292 Uart.highCnt = 0;
293 Uart.startTime = 0;
294 Uart.endTime = 0;
295 }
296
297 void UartInit(uint8_t *data, uint8_t *parity)
298 {
299 Uart.output = data;
300 Uart.parity = parity;
301 UartReset();
302 }
303
304 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
305 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
306 {
307
308 Uart.twoBits = (Uart.twoBits << 8) | bit;
309
310 if (Uart.state == STATE_UNSYNCD) { // not yet synced
311
312 if (Uart.highCnt < 7) { // wait for a stable unmodulated signal
313 if (Uart.twoBits == 0xffff) {
314 Uart.highCnt++;
315 } else {
316 Uart.highCnt = 0;
317 }
318 } else {
319 Uart.syncBit = 0xFFFF; // not set
320 // look for 00xx1111 (the start bit)
321 if ((Uart.twoBits & 0x6780) == 0x0780) Uart.syncBit = 7;
322 else if ((Uart.twoBits & 0x33C0) == 0x03C0) Uart.syncBit = 6;
323 else if ((Uart.twoBits & 0x19E0) == 0x01E0) Uart.syncBit = 5;
324 else if ((Uart.twoBits & 0x0CF0) == 0x00F0) Uart.syncBit = 4;
325 else if ((Uart.twoBits & 0x0678) == 0x0078) Uart.syncBit = 3;
326 else if ((Uart.twoBits & 0x033C) == 0x003C) Uart.syncBit = 2;
327 else if ((Uart.twoBits & 0x019E) == 0x001E) Uart.syncBit = 1;
328 else if ((Uart.twoBits & 0x00CF) == 0x000F) Uart.syncBit = 0;
329 if (Uart.syncBit != 0xFFFF) {
330 Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
331 Uart.startTime -= Uart.syncBit;
332 Uart.endTime = Uart.startTime;
333 Uart.state = STATE_START_OF_COMMUNICATION;
334 }
335 }
336
337 } else {
338
339 if (IsMillerModulationNibble1(Uart.twoBits >> Uart.syncBit)) {
340 if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation in both halves - error
341 UartReset();
342 Uart.highCnt = 6;
343 } else { // Modulation in first half = Sequence Z = logic "0"
344 if (Uart.state == STATE_MILLER_X) { // error - must not follow after X
345 UartReset();
346 Uart.highCnt = 6;
347 } else {
348 Uart.bitCount++;
349 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
350 Uart.state = STATE_MILLER_Z;
351 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
352 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
353 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
354 Uart.parityBits <<= 1; // make room for the parity bit
355 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
356 Uart.bitCount = 0;
357 Uart.shiftReg = 0;
358 if((Uart.len & 0x0007) == 0) { // every 8 data bytes
359 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
360 Uart.parityBits = 0;
361 }
362 }
363 }
364 }
365 } else {
366 if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1"
367 Uart.bitCount++;
368 Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg
369 Uart.state = STATE_MILLER_X;
370 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
371 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
372 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
373 Uart.parityBits <<= 1; // make room for the new parity bit
374 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
375 Uart.bitCount = 0;
376 Uart.shiftReg = 0;
377 if ((Uart.len & 0x0007) == 0) { // every 8 data bytes
378 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
379 Uart.parityBits = 0;
380 }
381 }
382 } else { // no modulation in both halves - Sequence Y
383 if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication
384 Uart.state = STATE_UNSYNCD;
385 Uart.bitCount--; // last "0" was part of EOC sequence
386 Uart.shiftReg <<= 1; // drop it
387 if(Uart.bitCount > 0) { // if we decoded some bits
388 Uart.shiftReg >>= (9 - Uart.bitCount); // right align them
389 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); // add last byte to the output
390 Uart.parityBits <<= 1; // add a (void) parity bit
391 Uart.parityBits <<= (8 - (Uart.len & 0x0007)); // left align parity bits
392 Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store it
393 return TRUE;
394 } else if (Uart.len & 0x0007) { // there are some parity bits to store
395 Uart.parityBits <<= (8 - (Uart.len & 0x0007)); // left align remaining parity bits
396 Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store them
397 }
398 if ( Uart.len) {
399 return TRUE; // we are finished with decoding the raw data sequence
400 } else {
401 UartReset(); // Nothing receiver - start over
402 }
403 }
404 if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC
405 UartReset();
406 Uart.highCnt = 6;
407 } else { // a logic "0"
408 Uart.bitCount++;
409 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
410 Uart.state = STATE_MILLER_Y;
411 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
412 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
413 Uart.parityBits <<= 1; // make room for the parity bit
414 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
415 Uart.bitCount = 0;
416 Uart.shiftReg = 0;
417 if ((Uart.len & 0x0007) == 0) { // every 8 data bytes
418 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
419 Uart.parityBits = 0;
420 }
421 }
422 }
423 }
424 }
425
426 }
427
428 return FALSE; // not finished yet, need more data
429 }
430
431
432
433 //=============================================================================
434 // ISO 14443 Type A - Manchester decoder
435 //=============================================================================
436 // Basics:
437 // This decoder is used when the PM3 acts as a reader.
438 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
439 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
440 // ........ 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 .......
441 // The Manchester decoder needs to identify the following sequences:
442 // 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication")
443 // 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0
444 // 8 ticks unmodulated: Sequence F = end of communication
445 // 8 ticks modulated: A collision. Save the collision position and treat as Sequence D
446 // Note 1: the bitstream may start at any time. We therefore need to sync.
447 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
448 static tDemod Demod;
449
450 // Lookup-Table to decide if 4 raw bits are a modulation.
451 // We accept three or four "1" in any position
452 const bool Mod_Manchester_LUT[] = {
453 FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
454 FALSE, FALSE, FALSE, TRUE, FALSE, TRUE, TRUE, TRUE
455 };
456
457 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
458 #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
459
460
461 void DemodReset()
462 {
463 Demod.state = DEMOD_UNSYNCD;
464 Demod.len = 0; // number of decoded data bytes
465 Demod.parityLen = 0;
466 Demod.shiftReg = 0; // shiftreg to hold decoded data bits
467 Demod.parityBits = 0; //
468 Demod.collisionPos = 0; // Position of collision bit
469 Demod.twoBits = 0xffff; // buffer for 2 Bits
470 Demod.highCnt = 0;
471 Demod.startTime = 0;
472 Demod.endTime = 0;
473 }
474
475 void DemodInit(uint8_t *data, uint8_t *parity)
476 {
477 Demod.output = data;
478 Demod.parity = parity;
479 DemodReset();
480 }
481
482 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
483 static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
484 {
485
486 Demod.twoBits = (Demod.twoBits << 8) | bit;
487
488 if (Demod.state == DEMOD_UNSYNCD) {
489
490 if (Demod.highCnt < 2) { // wait for a stable unmodulated signal
491 if (Demod.twoBits == 0x0000) {
492 Demod.highCnt++;
493 } else {
494 Demod.highCnt = 0;
495 }
496 } else {
497 Demod.syncBit = 0xFFFF; // not set
498 if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
499 else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
500 else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
501 else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
502 else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
503 else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
504 else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
505 else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
506 if (Demod.syncBit != 0xFFFF) {
507 Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
508 Demod.startTime -= Demod.syncBit;
509 Demod.bitCount = offset; // number of decoded data bits
510 Demod.state = DEMOD_MANCHESTER_DATA;
511 }
512 }
513
514 } else {
515
516 if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half
517 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... and in second half = collision
518 if (!Demod.collisionPos) {
519 Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
520 }
521 } // modulation in first half only - Sequence D = 1
522 Demod.bitCount++;
523 Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg
524 if(Demod.bitCount == 9) { // if we decoded a full byte (including parity)
525 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
526 Demod.parityBits <<= 1; // make room for the parity bit
527 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
528 Demod.bitCount = 0;
529 Demod.shiftReg = 0;
530 if((Demod.len & 0x0007) == 0) { // every 8 data bytes
531 Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits
532 Demod.parityBits = 0;
533 }
534 }
535 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
536 } else { // no modulation in first half
537 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // and modulation in second half = Sequence E = 0
538 Demod.bitCount++;
539 Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg
540 if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity)
541 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
542 Demod.parityBits <<= 1; // make room for the new parity bit
543 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
544 Demod.bitCount = 0;
545 Demod.shiftReg = 0;
546 if ((Demod.len & 0x0007) == 0) { // every 8 data bytes
547 Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits1
548 Demod.parityBits = 0;
549 }
550 }
551 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
552 } else { // no modulation in both halves - End of communication
553 if(Demod.bitCount > 0) { // there are some remaining data bits
554 Demod.shiftReg >>= (9 - Demod.bitCount); // right align the decoded bits
555 Demod.output[Demod.len++] = Demod.shiftReg & 0xff; // and add them to the output
556 Demod.parityBits <<= 1; // add a (void) parity bit
557 Demod.parityBits <<= (8 - (Demod.len & 0x0007)); // left align remaining parity bits
558 Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
559 return TRUE;
560 } else if (Demod.len & 0x0007) { // there are some parity bits to store
561 Demod.parityBits <<= (8 - (Demod.len & 0x0007)); // left align remaining parity bits
562 Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
563 }
564 if (Demod.len) {
565 return TRUE; // we are finished with decoding the raw data sequence
566 } else { // nothing received. Start over
567 DemodReset();
568 }
569 }
570 }
571
572 }
573
574 return FALSE; // not finished yet, need more data
575 }
576
577 //=============================================================================
578 // Finally, a `sniffer' for ISO 14443 Type A
579 // Both sides of communication!
580 //=============================================================================
581
582 //-----------------------------------------------------------------------------
583 // Record the sequence of commands sent by the reader to the tag, with
584 // triggering so that we start recording at the point that the tag is moved
585 // near the reader.
586 //-----------------------------------------------------------------------------
587 void RAMFUNC SnoopIso14443a(uint8_t param) {
588 // param:
589 // bit 0 - trigger from first card answer
590 // bit 1 - trigger from first reader 7-bit request
591
592 LEDsoff();
593 // init trace buffer
594 iso14a_clear_trace();
595 iso14a_set_tracing(TRUE);
596
597 // We won't start recording the frames that we acquire until we trigger;
598 // a good trigger condition to get started is probably when we see a
599 // response from the tag.
600 // triggered == FALSE -- to wait first for card
601 bool triggered = !(param & 0x03);
602
603 // The command (reader -> tag) that we're receiving.
604 // The length of a received command will in most cases be no more than 18 bytes.
605 // So 32 should be enough!
606 uint8_t *receivedCmd = ((uint8_t *)BigBuf) + RECV_CMD_OFFSET;
607 uint8_t *receivedCmdPar = ((uint8_t *)BigBuf) + RECV_CMD_PAR_OFFSET;
608
609 // The response (tag -> reader) that we're receiving.
610 uint8_t *receivedResponse = ((uint8_t *)BigBuf) + RECV_RESP_OFFSET;
611 uint8_t *receivedResponsePar = ((uint8_t *)BigBuf) + RECV_RESP_PAR_OFFSET;
612
613 // As we receive stuff, we copy it from receivedCmd or receivedResponse
614 // into trace, along with its length and other annotations.
615 //uint8_t *trace = (uint8_t *)BigBuf;
616
617 // The DMA buffer, used to stream samples from the FPGA
618 uint8_t *dmaBuf = ((uint8_t *)BigBuf) + DMA_BUFFER_OFFSET;
619 uint8_t *data = dmaBuf;
620 uint8_t previous_data = 0;
621 int maxDataLen = 0;
622 int dataLen = 0;
623 bool TagIsActive = FALSE;
624 bool ReaderIsActive = FALSE;
625
626 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
627
628 // Set up the demodulator for tag -> reader responses.
629 DemodInit(receivedResponse, receivedResponsePar);
630
631 // Set up the demodulator for the reader -> tag commands
632 UartInit(receivedCmd, receivedCmdPar);
633
634 // Setup and start DMA.
635 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
636
637 // And now we loop, receiving samples.
638 for(uint32_t rsamples = 0; TRUE; ) {
639
640 if(BUTTON_PRESS()) {
641 DbpString("cancelled by button");
642 break;
643 }
644
645 LED_A_ON();
646 WDT_HIT();
647
648 int register readBufDataP = data - dmaBuf;
649 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
650 if (readBufDataP <= dmaBufDataP){
651 dataLen = dmaBufDataP - readBufDataP;
652 } else {
653 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
654 }
655 // test for length of buffer
656 if(dataLen > maxDataLen) {
657 maxDataLen = dataLen;
658 if(dataLen > 400) {
659 Dbprintf("blew circular buffer! dataLen=%d", dataLen);
660 break;
661 }
662 }
663 if(dataLen < 1) continue;
664
665 // primary buffer was stopped( <-- we lost data!
666 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
667 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
668 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
669 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
670 }
671 // secondary buffer sets as primary, secondary buffer was stopped
672 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
673 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
674 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
675 }
676
677 LED_A_OFF();
678
679 if (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder
680
681 if(!TagIsActive) { // no need to try decoding reader data if the tag is sending
682 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
683 if (MillerDecoding(readerdata, (rsamples-1)*4)) {
684 LED_C_ON();
685
686 // check - if there is a short 7bit request from reader
687 if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
688
689 if(triggered) {
690 if (!LogTrace(receivedCmd,
691 Uart.len,
692 Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
693 Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
694 Uart.parity,
695 TRUE)) break;
696 }
697 /* And ready to receive another command. */
698 UartReset();
699 /* And also reset the demod code, which might have been */
700 /* false-triggered by the commands from the reader. */
701 DemodReset();
702 LED_B_OFF();
703 }
704 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
705 }
706
707 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time
708 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
709 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
710 LED_B_ON();
711
712 if (!LogTrace(receivedResponse,
713 Demod.len,
714 Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
715 Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
716 Demod.parity,
717 FALSE)) break;
718
719 if ((!triggered) && (param & 0x01)) triggered = TRUE;
720
721 // And ready to receive another response.
722 DemodReset();
723 LED_C_OFF();
724 }
725 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
726 }
727 }
728
729 previous_data = *data;
730 rsamples++;
731 data++;
732 if(data == dmaBuf + DMA_BUFFER_SIZE) {
733 data = dmaBuf;
734 }
735 } // main cycle
736
737 DbpString("COMMAND FINISHED");
738
739 FpgaDisableSscDma();
740 Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
741 Dbprintf("traceLen=%d, Uart.output[0]=%08x", traceLen, (uint32_t)Uart.output[0]);
742 LEDsoff();
743 }
744
745 //-----------------------------------------------------------------------------
746 // Prepare tag messages
747 //-----------------------------------------------------------------------------
748 static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity)
749 {
750 ToSendReset();
751
752 // Correction bit, might be removed when not needed
753 ToSendStuffBit(0);
754 ToSendStuffBit(0);
755 ToSendStuffBit(0);
756 ToSendStuffBit(0);
757 ToSendStuffBit(1); // 1
758 ToSendStuffBit(0);
759 ToSendStuffBit(0);
760 ToSendStuffBit(0);
761
762 // Send startbit
763 ToSend[++ToSendMax] = SEC_D;
764 LastProxToAirDuration = 8 * ToSendMax - 4;
765
766 for( uint16_t i = 0; i < len; i++) {
767 uint8_t b = cmd[i];
768
769 // Data bits
770 for(uint16_t j = 0; j < 8; j++) {
771 if(b & 1) {
772 ToSend[++ToSendMax] = SEC_D;
773 } else {
774 ToSend[++ToSendMax] = SEC_E;
775 }
776 b >>= 1;
777 }
778
779 // Get the parity bit
780 if (parity[i>>3] & (0x80>>(i&0x0007))) {
781 ToSend[++ToSendMax] = SEC_D;
782 LastProxToAirDuration = 8 * ToSendMax - 4;
783 } else {
784 ToSend[++ToSendMax] = SEC_E;
785 LastProxToAirDuration = 8 * ToSendMax;
786 }
787 }
788
789 // Send stopbit
790 ToSend[++ToSendMax] = SEC_F;
791
792 // Convert from last byte pos to length
793 ToSendMax++;
794 }
795
796 static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len)
797 {
798 uint8_t par[MAX_PARITY_SIZE];
799
800 GetParity(cmd, len, par);
801 CodeIso14443aAsTagPar(cmd, len, par);
802 }
803
804
805 static void Code4bitAnswerAsTag(uint8_t cmd)
806 {
807 int i;
808
809 ToSendReset();
810
811 // Correction bit, might be removed when not needed
812 ToSendStuffBit(0);
813 ToSendStuffBit(0);
814 ToSendStuffBit(0);
815 ToSendStuffBit(0);
816 ToSendStuffBit(1); // 1
817 ToSendStuffBit(0);
818 ToSendStuffBit(0);
819 ToSendStuffBit(0);
820
821 // Send startbit
822 ToSend[++ToSendMax] = SEC_D;
823
824 uint8_t b = cmd;
825 for(i = 0; i < 4; i++) {
826 if(b & 1) {
827 ToSend[++ToSendMax] = SEC_D;
828 LastProxToAirDuration = 8 * ToSendMax - 4;
829 } else {
830 ToSend[++ToSendMax] = SEC_E;
831 LastProxToAirDuration = 8 * ToSendMax;
832 }
833 b >>= 1;
834 }
835
836 // Send stopbit
837 ToSend[++ToSendMax] = SEC_F;
838
839 // Convert from last byte pos to length
840 ToSendMax++;
841 }
842
843 //-----------------------------------------------------------------------------
844 // Wait for commands from reader
845 // Stop when button is pressed
846 // Or return TRUE when command is captured
847 //-----------------------------------------------------------------------------
848 static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len)
849 {
850 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
851 // only, since we are receiving, not transmitting).
852 // Signal field is off with the appropriate LED
853 LED_D_OFF();
854 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
855
856 // Now run a `software UART' on the stream of incoming samples.
857 UartInit(received, parity);
858
859 // clear RXRDY:
860 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
861
862 for(;;) {
863 WDT_HIT();
864
865 if(BUTTON_PRESS()) return FALSE;
866
867 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
868 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
869 if(MillerDecoding(b, 0)) {
870 *len = Uart.len;
871 return TRUE;
872 }
873 }
874 }
875 }
876
877 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
878 int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
879 int EmSend4bit(uint8_t resp);
880 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par);
881 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
882 int EmSendCmd(uint8_t *resp, uint16_t respLen);
883 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par);
884 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
885 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity);
886
887 static uint8_t* free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
888
889 typedef struct {
890 uint8_t* response;
891 size_t response_n;
892 uint8_t* modulation;
893 size_t modulation_n;
894 uint32_t ProxToAirDuration;
895 } tag_response_info_t;
896
897 void reset_free_buffer() {
898 free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
899 }
900
901 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
902 // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
903 // This will need the following byte array for a modulation sequence
904 // 144 data bits (18 * 8)
905 // 18 parity bits
906 // 2 Start and stop
907 // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA)
908 // 1 just for the case
909 // ----------- +
910 // 166 bytes, since every bit that needs to be send costs us a byte
911 //
912
913 // Prepare the tag modulation bits from the message
914 CodeIso14443aAsTag(response_info->response,response_info->response_n);
915
916 // Make sure we do not exceed the free buffer space
917 if (ToSendMax > max_buffer_size) {
918 Dbprintf("Out of memory, when modulating bits for tag answer:");
919 Dbhexdump(response_info->response_n,response_info->response,false);
920 return false;
921 }
922
923 // Copy the byte array, used for this modulation to the buffer position
924 memcpy(response_info->modulation,ToSend,ToSendMax);
925
926 // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
927 response_info->modulation_n = ToSendMax;
928 response_info->ProxToAirDuration = LastProxToAirDuration;
929
930 return true;
931 }
932
933 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
934 // Retrieve and store the current buffer index
935 response_info->modulation = free_buffer_pointer;
936
937 // Determine the maximum size we can use from our buffer
938 size_t max_buffer_size = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + FREE_BUFFER_SIZE) - free_buffer_pointer;
939
940 // Forward the prepare tag modulation function to the inner function
941 if (prepare_tag_modulation(response_info,max_buffer_size)) {
942 // Update the free buffer offset
943 free_buffer_pointer += ToSendMax;
944 return true;
945 } else {
946 return false;
947 }
948 }
949
950 //-----------------------------------------------------------------------------
951 // Main loop of simulated tag: receive commands from reader, decide what
952 // response to send, and send it.
953 //-----------------------------------------------------------------------------
954 void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
955 {
956 // Enable and clear the trace
957 iso14a_clear_trace();
958 iso14a_set_tracing(TRUE);
959
960 uint8_t sak;
961
962 // The first response contains the ATQA (note: bytes are transmitted in reverse order).
963 uint8_t response1[2];
964
965 switch (tagType) {
966 case 1: { // MIFARE Classic
967 // Says: I am Mifare 1k - original line
968 response1[0] = 0x04;
969 response1[1] = 0x00;
970 sak = 0x08;
971 } break;
972 case 2: { // MIFARE Ultralight
973 // Says: I am a stupid memory tag, no crypto
974 response1[0] = 0x04;
975 response1[1] = 0x00;
976 sak = 0x00;
977 } break;
978 case 3: { // MIFARE DESFire
979 // Says: I am a DESFire tag, ph33r me
980 response1[0] = 0x04;
981 response1[1] = 0x03;
982 sak = 0x20;
983 } break;
984 case 4: { // ISO/IEC 14443-4
985 // Says: I am a javacard (JCOP)
986 response1[0] = 0x04;
987 response1[1] = 0x00;
988 sak = 0x28;
989 } break;
990 case 5: { // MIFARE TNP3XXX
991 // Says: I am a toy
992 response1[0] = 0x01;
993 response1[1] = 0x0f;
994 sak = 0x01;
995 } break;
996 default: {
997 Dbprintf("Error: unkown tagtype (%d)",tagType);
998 return;
999 } break;
1000 }
1001
1002 // The second response contains the (mandatory) first 24 bits of the UID
1003 uint8_t response2[5];
1004
1005 // Check if the uid uses the (optional) part
1006 uint8_t response2a[5];
1007 if (uid_2nd) {
1008 response2[0] = 0x88;
1009 num_to_bytes(uid_1st,3,response2+1);
1010 num_to_bytes(uid_2nd,4,response2a);
1011 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
1012
1013 // Configure the ATQA and SAK accordingly
1014 response1[0] |= 0x40;
1015 sak |= 0x04;
1016 } else {
1017 num_to_bytes(uid_1st,4,response2);
1018 // Configure the ATQA and SAK accordingly
1019 response1[0] &= 0xBF;
1020 sak &= 0xFB;
1021 }
1022
1023 // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
1024 response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
1025
1026 // Prepare the mandatory SAK (for 4 and 7 byte UID)
1027 uint8_t response3[3];
1028 response3[0] = sak;
1029 ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
1030
1031 // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
1032 uint8_t response3a[3];
1033 response3a[0] = sak & 0xFB;
1034 ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
1035
1036 uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
1037 uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS:
1038 // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
1039 // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
1040 // 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)
1041 // TC(1) = 0x02: CID supported, NAD not supported
1042 ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
1043
1044 #define TAG_RESPONSE_COUNT 7
1045 tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
1046 { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type
1047 { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid
1048 { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked
1049 { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1
1050 { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2
1051 { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce)
1052 { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS
1053 };
1054
1055 // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
1056 // Such a response is less time critical, so we can prepare them on the fly
1057 #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
1058 #define DYNAMIC_MODULATION_BUFFER_SIZE 512
1059 uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
1060 uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
1061 tag_response_info_t dynamic_response_info = {
1062 .response = dynamic_response_buffer,
1063 .response_n = 0,
1064 .modulation = dynamic_modulation_buffer,
1065 .modulation_n = 0
1066 };
1067
1068 // Reset the offset pointer of the free buffer
1069 reset_free_buffer();
1070
1071 // Prepare the responses of the anticollision phase
1072 // there will be not enough time to do this at the moment the reader sends it REQA
1073 for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
1074 prepare_allocated_tag_modulation(&responses[i]);
1075 }
1076
1077 int len = 0;
1078
1079 // To control where we are in the protocol
1080 int order = 0;
1081 int lastorder;
1082
1083 // Just to allow some checks
1084 int happened = 0;
1085 int happened2 = 0;
1086 int cmdsRecvd = 0;
1087
1088 // We need to listen to the high-frequency, peak-detected path.
1089 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1090
1091 // buffers used on software Uart:
1092 uint8_t *receivedCmd = ((uint8_t *)BigBuf) + RECV_CMD_OFFSET;
1093 uint8_t *receivedCmdPar = ((uint8_t *)BigBuf) + RECV_CMD_PAR_OFFSET;
1094
1095 cmdsRecvd = 0;
1096 tag_response_info_t* p_response;
1097
1098 LED_A_ON();
1099 for(;;) {
1100 // Clean receive command buffer
1101
1102 if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
1103 DbpString("Button press");
1104 break;
1105 }
1106
1107 p_response = NULL;
1108
1109 // Okay, look at the command now.
1110 lastorder = order;
1111 if(receivedCmd[0] == 0x26) { // Received a REQUEST
1112 p_response = &responses[0]; order = 1;
1113 } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
1114 p_response = &responses[0]; order = 6;
1115 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // Received request for UID (cascade 1)
1116 p_response = &responses[1]; order = 2;
1117 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2)
1118 p_response = &responses[2]; order = 20;
1119 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) { // Received a SELECT (cascade 1)
1120 p_response = &responses[3]; order = 3;
1121 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) { // Received a SELECT (cascade 2)
1122 p_response = &responses[4]; order = 30;
1123 } else if(receivedCmd[0] == 0x30) { // Received a (plain) READ
1124 EmSendCmdEx(data+(4*receivedCmd[1]),16,false);
1125 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1126 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1127 p_response = NULL;
1128 } else if(receivedCmd[0] == 0x50) { // Received a HALT
1129
1130 if (tracing) {
1131 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1132 }
1133 p_response = NULL;
1134 } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) { // Received an authentication request
1135 p_response = &responses[5]; order = 7;
1136 } else if(receivedCmd[0] == 0xE0) { // Received a RATS request
1137 if (tagType == 1 || tagType == 2) { // RATS not supported
1138 EmSend4bit(CARD_NACK_NA);
1139 p_response = NULL;
1140 } else {
1141 p_response = &responses[6]; order = 70;
1142 }
1143 } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
1144 if (tracing) {
1145 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1146 }
1147 uint32_t nr = bytes_to_num(receivedCmd,4);
1148 uint32_t ar = bytes_to_num(receivedCmd+4,4);
1149 Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar);
1150 } else {
1151 // Check for ISO 14443A-4 compliant commands, look at left nibble
1152 switch (receivedCmd[0]) {
1153
1154 case 0x0B:
1155 case 0x0A: { // IBlock (command)
1156 dynamic_response_info.response[0] = receivedCmd[0];
1157 dynamic_response_info.response[1] = 0x00;
1158 dynamic_response_info.response[2] = 0x90;
1159 dynamic_response_info.response[3] = 0x00;
1160 dynamic_response_info.response_n = 4;
1161 } break;
1162
1163 case 0x1A:
1164 case 0x1B: { // Chaining command
1165 dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1166 dynamic_response_info.response_n = 2;
1167 } break;
1168
1169 case 0xaa:
1170 case 0xbb: {
1171 dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1172 dynamic_response_info.response_n = 2;
1173 } break;
1174
1175 case 0xBA: { //
1176 memcpy(dynamic_response_info.response,"\xAB\x00",2);
1177 dynamic_response_info.response_n = 2;
1178 } break;
1179
1180 case 0xCA:
1181 case 0xC2: { // Readers sends deselect command
1182 memcpy(dynamic_response_info.response,"\xCA\x00",2);
1183 dynamic_response_info.response_n = 2;
1184 } break;
1185
1186 default: {
1187 // Never seen this command before
1188 if (tracing) {
1189 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1190 }
1191 Dbprintf("Received unknown command (len=%d):",len);
1192 Dbhexdump(len,receivedCmd,false);
1193 // Do not respond
1194 dynamic_response_info.response_n = 0;
1195 } break;
1196 }
1197
1198 if (dynamic_response_info.response_n > 0) {
1199 // Copy the CID from the reader query
1200 dynamic_response_info.response[1] = receivedCmd[1];
1201
1202 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1203 AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
1204 dynamic_response_info.response_n += 2;
1205
1206 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1207 Dbprintf("Error preparing tag response");
1208 if (tracing) {
1209 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1210 }
1211 break;
1212 }
1213 p_response = &dynamic_response_info;
1214 }
1215 }
1216
1217 // Count number of wakeups received after a halt
1218 if(order == 6 && lastorder == 5) { happened++; }
1219
1220 // Count number of other messages after a halt
1221 if(order != 6 && lastorder == 5) { happened2++; }
1222
1223 if(cmdsRecvd > 999) {
1224 DbpString("1000 commands later...");
1225 break;
1226 }
1227 cmdsRecvd++;
1228
1229 if (p_response != NULL) {
1230 EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1231 // do the tracing for the previous reader request and this tag answer:
1232 uint8_t par[MAX_PARITY_SIZE];
1233 GetParity(p_response->response, p_response->response_n, par);
1234
1235 EmLogTrace(Uart.output,
1236 Uart.len,
1237 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1238 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1239 Uart.parity,
1240 p_response->response,
1241 p_response->response_n,
1242 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1243 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1244 par);
1245 }
1246
1247 if (!tracing) {
1248 Dbprintf("Trace Full. Simulation stopped.");
1249 break;
1250 }
1251 }
1252
1253 Dbprintf("%x %x %x", happened, happened2, cmdsRecvd);
1254 LED_A_OFF();
1255 }
1256
1257
1258 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1259 // of bits specified in the delay parameter.
1260 void PrepareDelayedTransfer(uint16_t delay)
1261 {
1262 uint8_t bitmask = 0;
1263 uint8_t bits_to_shift = 0;
1264 uint8_t bits_shifted = 0;
1265
1266 delay &= 0x07;
1267 if (delay) {
1268 for (uint16_t i = 0; i < delay; i++) {
1269 bitmask |= (0x01 << i);
1270 }
1271 ToSend[ToSendMax++] = 0x00;
1272 for (uint16_t i = 0; i < ToSendMax; i++) {
1273 bits_to_shift = ToSend[i] & bitmask;
1274 ToSend[i] = ToSend[i] >> delay;
1275 ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1276 bits_shifted = bits_to_shift;
1277 }
1278 }
1279 }
1280
1281
1282 //-------------------------------------------------------------------------------------
1283 // Transmit the command (to the tag) that was placed in ToSend[].
1284 // Parameter timing:
1285 // if NULL: transfer at next possible time, taking into account
1286 // request guard time and frame delay time
1287 // if == 0: transfer immediately and return time of transfer
1288 // if != 0: delay transfer until time specified
1289 //-------------------------------------------------------------------------------------
1290 static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing)
1291 {
1292
1293 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1294
1295 uint32_t ThisTransferTime = 0;
1296
1297 if (timing) {
1298 if(*timing == 0) { // Measure time
1299 *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1300 } else {
1301 PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
1302 }
1303 if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
1304 while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
1305 LastTimeProxToAirStart = *timing;
1306 } else {
1307 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1308 while(GetCountSspClk() < ThisTransferTime);
1309 LastTimeProxToAirStart = ThisTransferTime;
1310 }
1311
1312 // clear TXRDY
1313 AT91C_BASE_SSC->SSC_THR = SEC_Y;
1314
1315 uint16_t c = 0;
1316 for(;;) {
1317 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1318 AT91C_BASE_SSC->SSC_THR = cmd[c];
1319 c++;
1320 if(c >= len) {
1321 break;
1322 }
1323 }
1324 }
1325
1326 NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1327 }
1328
1329
1330 //-----------------------------------------------------------------------------
1331 // Prepare reader command (in bits, support short frames) to send to FPGA
1332 //-----------------------------------------------------------------------------
1333 void CodeIso14443aBitsAsReaderPar(const uint8_t * cmd, uint16_t bits, const uint8_t *parity)
1334 {
1335 int i, j;
1336 int last;
1337 uint8_t b;
1338
1339 ToSendReset();
1340
1341 // Start of Communication (Seq. Z)
1342 ToSend[++ToSendMax] = SEC_Z;
1343 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1344 last = 0;
1345
1346 size_t bytecount = nbytes(bits);
1347 // Generate send structure for the data bits
1348 for (i = 0; i < bytecount; i++) {
1349 // Get the current byte to send
1350 b = cmd[i];
1351 size_t bitsleft = MIN((bits-(i*8)),8);
1352
1353 for (j = 0; j < bitsleft; j++) {
1354 if (b & 1) {
1355 // Sequence X
1356 ToSend[++ToSendMax] = SEC_X;
1357 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1358 last = 1;
1359 } else {
1360 if (last == 0) {
1361 // Sequence Z
1362 ToSend[++ToSendMax] = SEC_Z;
1363 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1364 } else {
1365 // Sequence Y
1366 ToSend[++ToSendMax] = SEC_Y;
1367 last = 0;
1368 }
1369 }
1370 b >>= 1;
1371 }
1372
1373 // Only transmit parity bit if we transmitted a complete byte
1374 if (j == 8) {
1375 // Get the parity bit
1376 if (parity[i>>3] & (0x80 >> (i&0x0007))) {
1377 // Sequence X
1378 ToSend[++ToSendMax] = SEC_X;
1379 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1380 last = 1;
1381 } else {
1382 if (last == 0) {
1383 // Sequence Z
1384 ToSend[++ToSendMax] = SEC_Z;
1385 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1386 } else {
1387 // Sequence Y
1388 ToSend[++ToSendMax] = SEC_Y;
1389 last = 0;
1390 }
1391 }
1392 }
1393 }
1394
1395 // End of Communication: Logic 0 followed by Sequence Y
1396 if (last == 0) {
1397 // Sequence Z
1398 ToSend[++ToSendMax] = SEC_Z;
1399 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1400 } else {
1401 // Sequence Y
1402 ToSend[++ToSendMax] = SEC_Y;
1403 last = 0;
1404 }
1405 ToSend[++ToSendMax] = SEC_Y;
1406
1407 // Convert to length of command:
1408 ToSendMax++;
1409 }
1410
1411 //-----------------------------------------------------------------------------
1412 // Prepare reader command to send to FPGA
1413 //-----------------------------------------------------------------------------
1414 void CodeIso14443aAsReaderPar(const uint8_t * cmd, uint16_t len, const uint8_t *parity)
1415 {
1416 CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
1417 }
1418
1419 //-----------------------------------------------------------------------------
1420 // Wait for commands from reader
1421 // Stop when button is pressed (return 1) or field was gone (return 2)
1422 // Or return 0 when command is captured
1423 //-----------------------------------------------------------------------------
1424 static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity)
1425 {
1426 *len = 0;
1427
1428 uint32_t timer = 0, vtime = 0;
1429 int analogCnt = 0;
1430 int analogAVG = 0;
1431
1432 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1433 // only, since we are receiving, not transmitting).
1434 // Signal field is off with the appropriate LED
1435 LED_D_OFF();
1436 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1437
1438 // Set ADC to read field strength
1439 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1440 AT91C_BASE_ADC->ADC_MR =
1441 ADC_MODE_PRESCALE(32) |
1442 ADC_MODE_STARTUP_TIME(16) |
1443 ADC_MODE_SAMPLE_HOLD_TIME(8);
1444 AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1445 // start ADC
1446 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1447
1448 // Now run a 'software UART' on the stream of incoming samples.
1449 UartInit(received, parity);
1450
1451 // Clear RXRDY:
1452 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1453
1454 for(;;) {
1455 WDT_HIT();
1456
1457 if (BUTTON_PRESS()) return 1;
1458
1459 // test if the field exists
1460 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1461 analogCnt++;
1462 analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1463 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1464 if (analogCnt >= 32) {
1465 if ((33000 * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1466 vtime = GetTickCount();
1467 if (!timer) timer = vtime;
1468 // 50ms no field --> card to idle state
1469 if (vtime - timer > 50) return 2;
1470 } else
1471 if (timer) timer = 0;
1472 analogCnt = 0;
1473 analogAVG = 0;
1474 }
1475 }
1476
1477 // receive and test the miller decoding
1478 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1479 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1480 if(MillerDecoding(b, 0)) {
1481 *len = Uart.len;
1482 return 0;
1483 }
1484 }
1485
1486 }
1487 }
1488
1489
1490 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded)
1491 {
1492 uint8_t b;
1493 uint16_t i = 0;
1494 uint32_t ThisTransferTime;
1495
1496 // Modulate Manchester
1497 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1498
1499 // include correction bit if necessary
1500 if (Uart.parityBits & 0x01) {
1501 correctionNeeded = TRUE;
1502 }
1503 if(correctionNeeded) {
1504 // 1236, so correction bit needed
1505 i = 0;
1506 } else {
1507 i = 1;
1508 }
1509
1510 // clear receiving shift register and holding register
1511 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1512 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1513 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1514 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1515
1516 // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1517 for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never
1518 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1519 if (AT91C_BASE_SSC->SSC_RHR) break;
1520 }
1521
1522 while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1523
1524 // Clear TXRDY:
1525 AT91C_BASE_SSC->SSC_THR = SEC_F;
1526
1527 // send cycle
1528 for(; i <= respLen; ) {
1529 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1530 AT91C_BASE_SSC->SSC_THR = resp[i++];
1531 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1532 }
1533
1534 if(BUTTON_PRESS()) {
1535 break;
1536 }
1537 }
1538
1539 // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1540 for (i = 0; i < 2 ; ) {
1541 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1542 AT91C_BASE_SSC->SSC_THR = SEC_F;
1543 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1544 i++;
1545 }
1546 }
1547
1548 LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
1549
1550 return 0;
1551 }
1552
1553 int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
1554 Code4bitAnswerAsTag(resp);
1555 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1556 // do the tracing for the previous reader request and this tag answer:
1557 uint8_t par[1];
1558 GetParity(&resp, 1, par);
1559 EmLogTrace(Uart.output,
1560 Uart.len,
1561 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1562 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1563 Uart.parity,
1564 &resp,
1565 1,
1566 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1567 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1568 par);
1569 return res;
1570 }
1571
1572 int EmSend4bit(uint8_t resp){
1573 return EmSend4bitEx(resp, false);
1574 }
1575
1576 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){
1577 CodeIso14443aAsTagPar(resp, respLen, par);
1578 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1579 // do the tracing for the previous reader request and this tag answer:
1580 EmLogTrace(Uart.output,
1581 Uart.len,
1582 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1583 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1584 Uart.parity,
1585 resp,
1586 respLen,
1587 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1588 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1589 par);
1590 return res;
1591 }
1592
1593 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){
1594 uint8_t par[MAX_PARITY_SIZE];
1595 GetParity(resp, respLen, par);
1596 return EmSendCmdExPar(resp, respLen, correctionNeeded, par);
1597 }
1598
1599 int EmSendCmd(uint8_t *resp, uint16_t respLen){
1600 uint8_t par[MAX_PARITY_SIZE];
1601 GetParity(resp, respLen, par);
1602 return EmSendCmdExPar(resp, respLen, false, par);
1603 }
1604
1605 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
1606 return EmSendCmdExPar(resp, respLen, false, par);
1607 }
1608
1609 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
1610 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity)
1611 {
1612 if (tracing) {
1613 // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1614 // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1615 // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1616 uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1617 uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1618 uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1619 reader_EndTime = tag_StartTime - exact_fdt;
1620 reader_StartTime = reader_EndTime - reader_modlen;
1621 if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE)) {
1622 return FALSE;
1623 } else return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
1624 } else {
1625 return TRUE;
1626 }
1627 }
1628
1629 //-----------------------------------------------------------------------------
1630 // Wait a certain time for tag response
1631 // If a response is captured return TRUE
1632 // If it takes too long return FALSE
1633 //-----------------------------------------------------------------------------
1634 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset)
1635 {
1636 uint32_t c;
1637
1638 // Set FPGA mode to "reader listen mode", no modulation (listen
1639 // only, since we are receiving, not transmitting).
1640 // Signal field is on with the appropriate LED
1641 LED_D_ON();
1642 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1643
1644 // Now get the answer from the card
1645 DemodInit(receivedResponse, receivedResponsePar);
1646
1647 // clear RXRDY:
1648 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1649
1650 c = 0;
1651 for(;;) {
1652 WDT_HIT();
1653
1654 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1655 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1656 if(ManchesterDecoding(b, offset, 0)) {
1657 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1658 return TRUE;
1659 } else if (c++ > iso14a_timeout) {
1660 return FALSE;
1661 }
1662 }
1663 }
1664 }
1665
1666 void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing)
1667 {
1668 CodeIso14443aBitsAsReaderPar(frame, bits, par);
1669
1670 // Send command to tag
1671 TransmitFor14443a(ToSend, ToSendMax, timing);
1672 if(trigger)
1673 LED_A_ON();
1674
1675 // Log reader command in trace buffer
1676 if (tracing) {
1677 LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
1678 }
1679 }
1680
1681 void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing)
1682 {
1683 ReaderTransmitBitsPar(frame, len*8, par, timing);
1684 }
1685
1686 void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing)
1687 {
1688 // Generate parity and redirect
1689 uint8_t par[MAX_PARITY_SIZE];
1690 GetParity(frame, len/8, par);
1691 ReaderTransmitBitsPar(frame, len, par, timing);
1692 }
1693
1694 void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing)
1695 {
1696 // Generate parity and redirect
1697 uint8_t par[MAX_PARITY_SIZE];
1698 GetParity(frame, len, par);
1699 ReaderTransmitBitsPar(frame, len*8, par, timing);
1700 }
1701
1702 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity)
1703 {
1704 if (!GetIso14443aAnswerFromTag(receivedAnswer,parity,offset)) return FALSE;
1705 if (tracing) {
1706 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1707 }
1708 return Demod.len;
1709 }
1710
1711 int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
1712 {
1713 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0)) return FALSE;
1714 if (tracing) {
1715 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1716 }
1717 return Demod.len;
1718 }
1719
1720 /* performs iso14443a anticollision procedure
1721 * fills the uid pointer unless NULL
1722 * fills resp_data unless NULL */
1723 int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, uint32_t* cuid_ptr) {
1724
1725 //uint8_t deselect[] = {0xc2}; //DESELECT
1726 //uint8_t halt[] = { 0x50, 0x00, 0x57, 0xCD }; // HALT
1727 uint8_t wupa[] = { 0x52 }; // WAKE-UP
1728 //uint8_t reqa[] = { 0x26 }; // REQUEST A
1729 uint8_t sel_all[] = { 0x93,0x20 };
1730 uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1731 uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1732 uint8_t *resp = ((uint8_t *)BigBuf) + RECV_RESP_OFFSET;
1733 uint8_t *resp_par = ((uint8_t *)BigBuf) + RECV_RESP_PAR_OFFSET;
1734
1735 byte_t uid_resp[4];
1736 size_t uid_resp_len;
1737 uint8_t sak = 0x04; // cascade uid
1738 int cascade_level = 0;
1739 int len =0;
1740
1741 // test for the SKYLANDERS TOY.
1742 // ReaderTransmit(deselect,sizeof(deselect), NULL);
1743 // len = ReaderReceive(resp, resp_par);
1744
1745 // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1746 ReaderTransmitBitsPar(wupa,7,0, NULL);
1747
1748 // Receive the ATQA
1749 if(!ReaderReceive(resp, resp_par)) return 0;
1750
1751 if(p_hi14a_card) {
1752 memcpy(p_hi14a_card->atqa, resp, 2);
1753 p_hi14a_card->uidlen = 0;
1754 memset(p_hi14a_card->uid,0,10);
1755 }
1756
1757 // clear uid
1758 if (uid_ptr) {
1759 memset(uid_ptr,0,10);
1760 }
1761
1762 // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1763 // which case we need to make a cascade 2 request and select - this is a long UID
1764 // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1765 for(; sak & 0x04; cascade_level++) {
1766 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1767 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1768
1769 // SELECT_ALL
1770 ReaderTransmit(sel_all,sizeof(sel_all), NULL);
1771 if (!ReaderReceive(resp, resp_par)) return 0;
1772
1773 if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit
1774 memset(uid_resp, 0, 4);
1775 uint16_t uid_resp_bits = 0;
1776 uint16_t collision_answer_offset = 0;
1777 // anti-collision-loop:
1778 while (Demod.collisionPos) {
1779 Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1780 for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point
1781 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1782 uid_resp[uid_resp_bits & 0xf8] |= UIDbit << (uid_resp_bits % 8);
1783 }
1784 uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position
1785 uid_resp_bits++;
1786 // construct anticollosion command:
1787 sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits
1788 for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1789 sel_uid[2+i] = uid_resp[i];
1790 }
1791 collision_answer_offset = uid_resp_bits%8;
1792 ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1793 if (!ReaderReceiveOffset(resp, collision_answer_offset,resp_par)) return 0;
1794 }
1795 // finally, add the last bits and BCC of the UID
1796 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1797 uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1798 uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1799 }
1800
1801 } else { // no collision, use the response to SELECT_ALL as current uid
1802 memcpy(uid_resp,resp,4);
1803 }
1804 uid_resp_len = 4;
1805
1806 // calculate crypto UID. Always use last 4 Bytes.
1807 if(cuid_ptr) {
1808 *cuid_ptr = bytes_to_num(uid_resp, 4);
1809 }
1810
1811 // Construct SELECT UID command
1812 sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1813 memcpy(sel_uid+2,uid_resp,4); // the UID
1814 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC
1815 AppendCrc14443a(sel_uid,7); // calculate and add CRC
1816 ReaderTransmit(sel_uid,sizeof(sel_uid), NULL);
1817
1818 // Receive the SAK
1819 if (!ReaderReceive(resp, resp_par)) return 0;
1820 sak = resp[0];
1821
1822 // Test if more parts of the uid are coming
1823 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
1824 // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
1825 // http://www.nxp.com/documents/application_note/AN10927.pdf
1826 uid_resp[0] = uid_resp[1];
1827 uid_resp[1] = uid_resp[2];
1828 uid_resp[2] = uid_resp[3];
1829
1830 uid_resp_len = 3;
1831 }
1832
1833 if(uid_ptr) {
1834 memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
1835 }
1836
1837 if(p_hi14a_card) {
1838 memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
1839 p_hi14a_card->uidlen += uid_resp_len;
1840 }
1841 }
1842
1843 if(p_hi14a_card) {
1844 p_hi14a_card->sak = sak;
1845 p_hi14a_card->ats_len = 0;
1846 }
1847
1848 // non iso14443a compliant tag
1849 if( (sak & 0x20) == 0) return 2;
1850
1851 // Request for answer to select
1852 AppendCrc14443a(rats, 2);
1853 ReaderTransmit(rats, sizeof(rats), NULL);
1854
1855 if (!(len = ReaderReceive(resp, resp_par))) return 0;
1856
1857
1858 if(p_hi14a_card) {
1859 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
1860 p_hi14a_card->ats_len = len;
1861 }
1862
1863 // reset the PCB block number
1864 iso14_pcb_blocknum = 0;
1865 return 1;
1866 }
1867
1868 void iso14443a_setup(uint8_t fpga_minor_mode) {
1869 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1870 // Set up the synchronous serial port
1871 FpgaSetupSsc();
1872 // connect Demodulated Signal to ADC:
1873 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1874
1875 // Signal field is on with the appropriate LED
1876 if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
1877 LED_D_ON();
1878 } else {
1879 LED_D_OFF();
1880 }
1881 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
1882
1883 // Start the timer
1884 StartCountSspClk();
1885
1886 DemodReset();
1887 UartReset();
1888 NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
1889 iso14a_set_timeout(1050); // 10ms default 10*105 =
1890 }
1891
1892 int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
1893 uint8_t parity[MAX_PARITY_SIZE];
1894 uint8_t real_cmd[cmd_len+4];
1895 real_cmd[0] = 0x0a; //I-Block
1896 // put block number into the PCB
1897 real_cmd[0] |= iso14_pcb_blocknum;
1898 real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
1899 memcpy(real_cmd+2, cmd, cmd_len);
1900 AppendCrc14443a(real_cmd,cmd_len+2);
1901
1902 ReaderTransmit(real_cmd, cmd_len+4, NULL);
1903 size_t len = ReaderReceive(data, parity);
1904 uint8_t * data_bytes = (uint8_t *) data;
1905 if (!len)
1906 return 0; //DATA LINK ERROR
1907 // if we received an I- or R(ACK)-Block with a block number equal to the
1908 // current block number, toggle the current block number
1909 else if (len >= 4 // PCB+CID+CRC = 4 bytes
1910 && ((data_bytes[0] & 0xC0) == 0 // I-Block
1911 || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
1912 && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
1913 {
1914 iso14_pcb_blocknum ^= 1;
1915 }
1916
1917 return len;
1918 }
1919
1920 //-----------------------------------------------------------------------------
1921 // Read an ISO 14443a tag. Send out commands and store answers.
1922 //
1923 //-----------------------------------------------------------------------------
1924 void ReaderIso14443a(UsbCommand *c)
1925 {
1926 iso14a_command_t param = c->arg[0];
1927 uint8_t *cmd = c->d.asBytes;
1928 size_t len = c->arg[1];
1929 size_t lenbits = c->arg[2];
1930 uint32_t arg0 = 0;
1931 byte_t buf[USB_CMD_DATA_SIZE];
1932 uint8_t par[MAX_PARITY_SIZE];
1933
1934 if(param & ISO14A_CONNECT) {
1935 iso14a_clear_trace();
1936 }
1937
1938 iso14a_set_tracing(TRUE);
1939
1940 if(param & ISO14A_REQUEST_TRIGGER) {
1941 iso14a_set_trigger(TRUE);
1942 }
1943
1944 if(param & ISO14A_CONNECT) {
1945 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
1946 if(!(param & ISO14A_NO_SELECT)) {
1947 iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
1948 arg0 = iso14443a_select_card(NULL,card,NULL);
1949 cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
1950 }
1951 }
1952
1953 if(param & ISO14A_SET_TIMEOUT) {
1954 iso14a_set_timeout(c->arg[2]);
1955 }
1956
1957 if(param & ISO14A_APDU) {
1958 arg0 = iso14_apdu(cmd, len, buf);
1959 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
1960 }
1961
1962 if(param & ISO14A_RAW) {
1963 if(param & ISO14A_APPEND_CRC) {
1964 AppendCrc14443a(cmd,len);
1965 len += 2;
1966 if (lenbits) lenbits += 16;
1967 }
1968 if(lenbits>0) {
1969 GetParity(cmd, lenbits/8, par);
1970 ReaderTransmitBitsPar(cmd, lenbits, par, NULL);
1971 } else {
1972 ReaderTransmit(cmd,len, NULL);
1973 }
1974 arg0 = ReaderReceive(buf, par);
1975 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
1976 }
1977
1978 if(param & ISO14A_REQUEST_TRIGGER) {
1979 iso14a_set_trigger(FALSE);
1980 }
1981
1982 if(param & ISO14A_NO_DISCONNECT) {
1983 return;
1984 }
1985
1986 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1987 LEDsoff();
1988 }
1989
1990
1991 // Determine the distance between two nonces.
1992 // Assume that the difference is small, but we don't know which is first.
1993 // Therefore try in alternating directions.
1994 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
1995
1996 uint16_t i;
1997 uint32_t nttmp1, nttmp2;
1998
1999 if (nt1 == nt2) return 0;
2000
2001 nttmp1 = nt1;
2002 nttmp2 = nt2;
2003
2004 for (i = 1; i < 32768; i++) {
2005 nttmp1 = prng_successor(nttmp1, 1);
2006 if (nttmp1 == nt2) return i;
2007 nttmp2 = prng_successor(nttmp2, 1);
2008 if (nttmp2 == nt1) return -i;
2009 }
2010
2011 return(-99999); // either nt1 or nt2 are invalid nonces
2012 }
2013
2014
2015 //-----------------------------------------------------------------------------
2016 // Recover several bits of the cypher stream. This implements (first stages of)
2017 // the algorithm described in "The Dark Side of Security by Obscurity and
2018 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
2019 // (article by Nicolas T. Courtois, 2009)
2020 //-----------------------------------------------------------------------------
2021 void ReaderMifare(bool first_try)
2022 {
2023 // Mifare AUTH
2024 uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b };
2025 uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
2026 static uint8_t mf_nr_ar3;
2027
2028 uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + RECV_RESP_OFFSET);
2029 uint8_t* receivedAnswerPar = (((uint8_t *)BigBuf) + RECV_RESP_PAR_OFFSET);
2030
2031 iso14a_clear_trace();
2032 iso14a_set_tracing(TRUE);
2033
2034 byte_t nt_diff = 0;
2035 uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
2036 static byte_t par_low = 0;
2037 bool led_on = TRUE;
2038 uint8_t uid[10] ={0};
2039 uint32_t cuid;
2040
2041 uint32_t nt = 0;
2042 uint32_t previous_nt = 0;
2043 static uint32_t nt_attacked = 0;
2044 byte_t par_list[8] = {0x00};
2045 byte_t ks_list[8] = {0x00};
2046
2047 static uint32_t sync_time;
2048 static uint32_t sync_cycles;
2049 int catch_up_cycles = 0;
2050 int last_catch_up = 0;
2051 uint16_t consecutive_resyncs = 0;
2052 int isOK = 0;
2053
2054 if (first_try) {
2055 mf_nr_ar3 = 0;
2056 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2057 sync_time = GetCountSspClk() & 0xfffffff8;
2058 sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
2059 nt_attacked = 0;
2060 nt = 0;
2061 par[0] = 0;
2062 }
2063 else {
2064 // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
2065 mf_nr_ar3++;
2066 mf_nr_ar[3] = mf_nr_ar3;
2067 par[0] = par_low;
2068 }
2069
2070 LED_A_ON();
2071 LED_B_OFF();
2072 LED_C_OFF();
2073
2074
2075 for(uint16_t i = 0; TRUE; i++) {
2076
2077 WDT_HIT();
2078
2079 // Test if the action was cancelled
2080 if(BUTTON_PRESS()) {
2081 break;
2082 }
2083
2084 LED_C_ON();
2085
2086 if(!iso14443a_select_card(uid, NULL, &cuid)) {
2087 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
2088 continue;
2089 }
2090
2091 sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
2092 catch_up_cycles = 0;
2093
2094 // if we missed the sync time already, advance to the next nonce repeat
2095 while(GetCountSspClk() > sync_time) {
2096 sync_time = (sync_time & 0xfffffff8) + sync_cycles;
2097 }
2098
2099 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2100 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2101
2102 // Receive the (4 Byte) "random" nonce
2103 if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2104 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce");
2105 continue;
2106 }
2107
2108 previous_nt = nt;
2109 nt = bytes_to_num(receivedAnswer, 4);
2110
2111 // Transmit reader nonce with fake par
2112 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2113
2114 if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
2115 int nt_distance = dist_nt(previous_nt, nt);
2116 if (nt_distance == 0) {
2117 nt_attacked = nt;
2118 }
2119 else {
2120 if (nt_distance == -99999) { // invalid nonce received, try again
2121 continue;
2122 }
2123 sync_cycles = (sync_cycles - nt_distance);
2124 if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
2125 continue;
2126 }
2127 }
2128
2129 if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
2130 catch_up_cycles = -dist_nt(nt_attacked, nt);
2131 if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one.
2132 catch_up_cycles = 0;
2133 continue;
2134 }
2135 if (catch_up_cycles == last_catch_up) {
2136 consecutive_resyncs++;
2137 }
2138 else {
2139 last_catch_up = catch_up_cycles;
2140 consecutive_resyncs = 0;
2141 }
2142 if (consecutive_resyncs < 3) {
2143 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);
2144 }
2145 else {
2146 sync_cycles = sync_cycles + catch_up_cycles;
2147 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);
2148 }
2149 continue;
2150 }
2151
2152 consecutive_resyncs = 0;
2153
2154 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2155 if (ReaderReceive(receivedAnswer, receivedAnswerPar))
2156 {
2157 catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2158
2159 if (nt_diff == 0)
2160 {
2161 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
2162 }
2163
2164 led_on = !led_on;
2165 if(led_on) LED_B_ON(); else LED_B_OFF();
2166
2167 par_list[nt_diff] = SwapBits(par[0], 8);
2168 ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
2169
2170 // Test if the information is complete
2171 if (nt_diff == 0x07) {
2172 isOK = 1;
2173 break;
2174 }
2175
2176 nt_diff = (nt_diff + 1) & 0x07;
2177 mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2178 par[0] = par_low;
2179 } else {
2180 if (nt_diff == 0 && first_try)
2181 {
2182 par[0]++;
2183 } else {
2184 par[0] = ((par[0] & 0x1F) + 1) | par_low;
2185 }
2186 }
2187 }
2188
2189
2190 mf_nr_ar[3] &= 0x1F;
2191
2192 byte_t buf[28];
2193 memcpy(buf + 0, uid, 4);
2194 num_to_bytes(nt, 4, buf + 4);
2195 memcpy(buf + 8, par_list, 8);
2196 memcpy(buf + 16, ks_list, 8);
2197 memcpy(buf + 24, mf_nr_ar, 4);
2198
2199 cmd_send(CMD_ACK,isOK,0,0,buf,28);
2200
2201 // Thats it...
2202 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2203 LEDsoff();
2204
2205 iso14a_set_tracing(FALSE);
2206 }
2207
2208 /**
2209 *MIFARE 1K simulate.
2210 *
2211 *@param flags :
2212 * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2213 * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
2214 * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
2215 * FLAG_NR_AR_ATTACK - means we should collect NR_AR responses for bruteforcing later
2216 *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2217 */
2218 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
2219 {
2220 int cardSTATE = MFEMUL_NOFIELD;
2221 int _7BUID = 0;
2222 int vHf = 0; // in mV
2223 int res;
2224 uint32_t selTimer = 0;
2225 uint32_t authTimer = 0;
2226 uint16_t len = 0;
2227 uint8_t cardWRBL = 0;
2228 uint8_t cardAUTHSC = 0;
2229 uint8_t cardAUTHKEY = 0xff; // no authentication
2230 uint32_t cardRr = 0;
2231 uint32_t cuid = 0;
2232 //uint32_t rn_enc = 0;
2233 uint32_t ans = 0;
2234 uint32_t cardINTREG = 0;
2235 uint8_t cardINTBLOCK = 0;
2236 struct Crypto1State mpcs = {0, 0};
2237 struct Crypto1State *pcs;
2238 pcs = &mpcs;
2239 uint32_t numReads = 0;//Counts numer of times reader read a block
2240 uint8_t* receivedCmd = get_bigbufptr_recvcmdbuf();
2241 uint8_t* receivedCmd_par = receivedCmd + MAX_FRAME_SIZE;
2242 uint8_t* response = get_bigbufptr_recvrespbuf();
2243 uint8_t* response_par = response + MAX_FRAME_SIZE;
2244
2245 uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
2246 uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2247 uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
2248 uint8_t rSAK[] = {0x08, 0xb6, 0xdd};
2249 uint8_t rSAK1[] = {0x04, 0xda, 0x17};
2250
2251 uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04};
2252 uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2253
2254 //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
2255 // This can be used in a reader-only attack.
2256 // (it can also be retrieved via 'hf 14a list', but hey...
2257 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
2258 uint8_t ar_nr_collected = 0;
2259
2260 // clear trace
2261 iso14a_clear_trace();
2262 iso14a_set_tracing(TRUE);
2263
2264 // Authenticate response - nonce
2265 uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2266
2267 //-- Determine the UID
2268 // Can be set from emulator memory, incoming data
2269 // and can be 7 or 4 bytes long
2270 if (flags & FLAG_4B_UID_IN_DATA)
2271 {
2272 // 4B uid comes from data-portion of packet
2273 memcpy(rUIDBCC1,datain,4);
2274 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2275
2276 } else if (flags & FLAG_7B_UID_IN_DATA) {
2277 // 7B uid comes from data-portion of packet
2278 memcpy(&rUIDBCC1[1],datain,3);
2279 memcpy(rUIDBCC2, datain+3, 4);
2280 _7BUID = true;
2281 } else {
2282 // get UID from emul memory
2283 emlGetMemBt(receivedCmd, 7, 1);
2284 _7BUID = !(receivedCmd[0] == 0x00);
2285 if (!_7BUID) { // ---------- 4BUID
2286 emlGetMemBt(rUIDBCC1, 0, 4);
2287 } else { // ---------- 7BUID
2288 emlGetMemBt(&rUIDBCC1[1], 0, 3);
2289 emlGetMemBt(rUIDBCC2, 3, 4);
2290 }
2291 }
2292
2293 /*
2294 * Regardless of what method was used to set the UID, set fifth byte and modify
2295 * the ATQA for 4 or 7-byte UID
2296 */
2297 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2298 if (_7BUID) {
2299 rATQA[0] = 0x44;
2300 rUIDBCC1[0] = 0x88;
2301 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2302 }
2303
2304 // We need to listen to the high-frequency, peak-detected path.
2305 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2306
2307
2308 if (MF_DBGLEVEL >= 1) {
2309 if (!_7BUID) {
2310 Dbprintf("4B UID: %02x%02x%02x%02x",
2311 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3]);
2312 } else {
2313 Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",
2314 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3],
2315 rUIDBCC2[0], rUIDBCC2[1] ,rUIDBCC2[2], rUIDBCC2[3]);
2316 }
2317 }
2318
2319 bool finished = FALSE;
2320 while (!BUTTON_PRESS() && !finished) {
2321 WDT_HIT();
2322
2323 // find reader field
2324 // Vref = 3300mV, and an 10:1 voltage divider on the input
2325 // can measure voltages up to 33000 mV
2326 if (cardSTATE == MFEMUL_NOFIELD) {
2327 vHf = (33000 * AvgAdc(ADC_CHAN_HF)) >> 10;
2328 if (vHf > MF_MINFIELDV) {
2329 cardSTATE_TO_IDLE();
2330 LED_A_ON();
2331 }
2332 }
2333 if(cardSTATE == MFEMUL_NOFIELD) continue;
2334
2335 //Now, get data
2336
2337 res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
2338 if (res == 2) { //Field is off!
2339 cardSTATE = MFEMUL_NOFIELD;
2340 LEDsoff();
2341 continue;
2342 } else if (res == 1) {
2343 break; //return value 1 means button press
2344 }
2345
2346 // REQ or WUP request in ANY state and WUP in HALTED state
2347 if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
2348 selTimer = GetTickCount();
2349 EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
2350 cardSTATE = MFEMUL_SELECT1;
2351
2352 // init crypto block
2353 LED_B_OFF();
2354 LED_C_OFF();
2355 crypto1_destroy(pcs);
2356 cardAUTHKEY = 0xff;
2357 continue;
2358 }
2359
2360 switch (cardSTATE) {
2361 case MFEMUL_NOFIELD:
2362 case MFEMUL_HALTED:
2363 case MFEMUL_IDLE:{
2364 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2365 break;
2366 }
2367 case MFEMUL_SELECT1:{
2368 // select all
2369 if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
2370 if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received");
2371 EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2372 break;
2373 }
2374
2375 if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
2376 {
2377 Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
2378 }
2379 // select card
2380 if (len == 9 &&
2381 (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2382 EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK));
2383 cuid = bytes_to_num(rUIDBCC1, 4);
2384 if (!_7BUID) {
2385 cardSTATE = MFEMUL_WORK;
2386 LED_B_ON();
2387 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2388 break;
2389 } else {
2390 cardSTATE = MFEMUL_SELECT2;
2391 }
2392 }
2393 break;
2394 }
2395 case MFEMUL_AUTH1:{
2396 if( len != 8)
2397 {
2398 cardSTATE_TO_IDLE();
2399 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2400 break;
2401 }
2402 uint32_t ar = bytes_to_num(receivedCmd, 4);
2403 uint32_t nr = bytes_to_num(&receivedCmd[4], 4);
2404
2405 //Collect AR/NR
2406 if(ar_nr_collected < 2){
2407 if(ar_nr_responses[2] != ar)
2408 {// Avoid duplicates... probably not necessary, ar should vary.
2409 ar_nr_responses[ar_nr_collected*4] = cuid;
2410 ar_nr_responses[ar_nr_collected*4+1] = nonce;
2411 ar_nr_responses[ar_nr_collected*4+2] = ar;
2412 ar_nr_responses[ar_nr_collected*4+3] = nr;
2413 ar_nr_collected++;
2414 }
2415 }
2416
2417 // --- crypto
2418 crypto1_word(pcs, ar , 1);
2419 cardRr = nr ^ crypto1_word(pcs, 0, 0);
2420
2421 // test if auth OK
2422 if (cardRr != prng_successor(nonce, 64)){
2423 if (MF_DBGLEVEL >= 2) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
2424 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2425 cardRr, prng_successor(nonce, 64));
2426 // Shouldn't we respond anything here?
2427 // Right now, we don't nack or anything, which causes the
2428 // reader to do a WUPA after a while. /Martin
2429 // -- which is the correct response. /piwi
2430 cardSTATE_TO_IDLE();
2431 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2432 break;
2433 }
2434
2435 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2436
2437 num_to_bytes(ans, 4, rAUTH_AT);
2438 // --- crypto
2439 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2440 LED_C_ON();
2441 cardSTATE = MFEMUL_WORK;
2442 if (MF_DBGLEVEL >= 4) Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2443 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2444 GetTickCount() - authTimer);
2445 break;
2446 }
2447 case MFEMUL_SELECT2:{
2448 if (!len) {
2449 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2450 break;
2451 }
2452 if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
2453 EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2454 break;
2455 }
2456
2457 // select 2 card
2458 if (len == 9 &&
2459 (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
2460 EmSendCmd(rSAK, sizeof(rSAK));
2461 cuid = bytes_to_num(rUIDBCC2, 4);
2462 cardSTATE = MFEMUL_WORK;
2463 LED_B_ON();
2464 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2465 break;
2466 }
2467
2468 // i guess there is a command). go into the work state.
2469 if (len != 4) {
2470 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2471 break;
2472 }
2473 cardSTATE = MFEMUL_WORK;
2474 //goto lbWORK;
2475 //intentional fall-through to the next case-stmt
2476 }
2477
2478 case MFEMUL_WORK:{
2479 if (len == 0) {
2480 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2481 break;
2482 }
2483
2484 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2485
2486 if(encrypted_data) {
2487 // decrypt seqence
2488 mf_crypto1_decrypt(pcs, receivedCmd, len);
2489 }
2490
2491 if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
2492 authTimer = GetTickCount();
2493 cardAUTHSC = receivedCmd[1] / 4; // received block num
2494 cardAUTHKEY = receivedCmd[0] - 0x60;
2495 crypto1_destroy(pcs);//Added by martin
2496 crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2497
2498 if (!encrypted_data) { // first authentication
2499 if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2500
2501 crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
2502 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2503 } else { // nested authentication
2504 if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2505 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2506 num_to_bytes(ans, 4, rAUTH_AT);
2507 }
2508 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2509 //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
2510 cardSTATE = MFEMUL_AUTH1;
2511 break;
2512 }
2513
2514 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2515 // BUT... ACK --> NACK
2516 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2517 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2518 break;
2519 }
2520
2521 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2522 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2523 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2524 break;
2525 }
2526
2527 if(len != 4) {
2528 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2529 break;
2530 }
2531
2532 if(receivedCmd[0] == 0x30 // read block
2533 || receivedCmd[0] == 0xA0 // write block
2534 || receivedCmd[0] == 0xC0 // inc
2535 || receivedCmd[0] == 0xC1 // dec
2536 || receivedCmd[0] == 0xC2 // restore
2537 || receivedCmd[0] == 0xB0) { // transfer
2538 if (receivedCmd[1] >= 16 * 4) {
2539 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2540 if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2541 break;
2542 }
2543
2544 if (receivedCmd[1] / 4 != cardAUTHSC) {
2545 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2546 if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
2547 break;
2548 }
2549 }
2550 // read block
2551 if (receivedCmd[0] == 0x30) {
2552 if (MF_DBGLEVEL >= 4) {
2553 Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
2554 }
2555 emlGetMem(response, receivedCmd[1], 1);
2556 AppendCrc14443a(response, 16);
2557 mf_crypto1_encrypt(pcs, response, 18, response_par);
2558 EmSendCmdPar(response, 18, response_par);
2559 numReads++;
2560 if(exitAfterNReads > 0 && numReads == exitAfterNReads) {
2561 Dbprintf("%d reads done, exiting", numReads);
2562 finished = true;
2563 }
2564 break;
2565 }
2566 // write block
2567 if (receivedCmd[0] == 0xA0) {
2568 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
2569 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2570 cardSTATE = MFEMUL_WRITEBL2;
2571 cardWRBL = receivedCmd[1];
2572 break;
2573 }
2574 // increment, decrement, restore
2575 if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
2576 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2577 if (emlCheckValBl(receivedCmd[1])) {
2578 if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2579 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2580 break;
2581 }
2582 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2583 if (receivedCmd[0] == 0xC1)
2584 cardSTATE = MFEMUL_INTREG_INC;
2585 if (receivedCmd[0] == 0xC0)
2586 cardSTATE = MFEMUL_INTREG_DEC;
2587 if (receivedCmd[0] == 0xC2)
2588 cardSTATE = MFEMUL_INTREG_REST;
2589 cardWRBL = receivedCmd[1];
2590 break;
2591 }
2592 // transfer
2593 if (receivedCmd[0] == 0xB0) {
2594 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2595 if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2596 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2597 else
2598 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2599 break;
2600 }
2601 // halt
2602 if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
2603 LED_B_OFF();
2604 LED_C_OFF();
2605 cardSTATE = MFEMUL_HALTED;
2606 if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer);
2607 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2608 break;
2609 }
2610 // RATS
2611 if (receivedCmd[0] == 0xe0) {//RATS
2612 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2613 break;
2614 }
2615 // command not allowed
2616 if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking");
2617 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2618 break;
2619 }
2620 case MFEMUL_WRITEBL2:{
2621 if (len == 18){
2622 mf_crypto1_decrypt(pcs, receivedCmd, len);
2623 emlSetMem(receivedCmd, cardWRBL, 1);
2624 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2625 cardSTATE = MFEMUL_WORK;
2626 } else {
2627 cardSTATE_TO_IDLE();
2628 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2629 }
2630 break;
2631 }
2632
2633 case MFEMUL_INTREG_INC:{
2634 mf_crypto1_decrypt(pcs, receivedCmd, len);
2635 memcpy(&ans, receivedCmd, 4);
2636 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2637 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2638 cardSTATE_TO_IDLE();
2639 break;
2640 }
2641 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2642 cardINTREG = cardINTREG + ans;
2643 cardSTATE = MFEMUL_WORK;
2644 break;
2645 }
2646 case MFEMUL_INTREG_DEC:{
2647 mf_crypto1_decrypt(pcs, receivedCmd, len);
2648 memcpy(&ans, receivedCmd, 4);
2649 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2650 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2651 cardSTATE_TO_IDLE();
2652 break;
2653 }
2654 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2655 cardINTREG = cardINTREG - ans;
2656 cardSTATE = MFEMUL_WORK;
2657 break;
2658 }
2659 case MFEMUL_INTREG_REST:{
2660 mf_crypto1_decrypt(pcs, receivedCmd, len);
2661 memcpy(&ans, receivedCmd, 4);
2662 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2663 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2664 cardSTATE_TO_IDLE();
2665 break;
2666 }
2667 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2668 cardSTATE = MFEMUL_WORK;
2669 break;
2670 }
2671 }
2672 }
2673
2674 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2675 LEDsoff();
2676
2677 if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
2678 {
2679 //May just aswell send the collected ar_nr in the response aswell
2680 cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_responses,ar_nr_collected*4*4);
2681 }
2682
2683 if(flags & FLAG_NR_AR_ATTACK)
2684 {
2685 if(ar_nr_collected > 1) {
2686 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
2687 Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
2688 ar_nr_responses[0], // UID
2689 ar_nr_responses[1], //NT
2690 ar_nr_responses[2], //AR1
2691 ar_nr_responses[3], //NR1
2692 ar_nr_responses[6], //AR2
2693 ar_nr_responses[7] //NR2
2694 );
2695 } else {
2696 Dbprintf("Failed to obtain two AR/NR pairs!");
2697 if(ar_nr_collected >0) {
2698 Dbprintf("Only got these: UID=%08x, nonce=%08x, AR1=%08x, NR1=%08x",
2699 ar_nr_responses[0], // UID
2700 ar_nr_responses[1], //NT
2701 ar_nr_responses[2], //AR1
2702 ar_nr_responses[3] //NR1
2703 );
2704 }
2705 }
2706 }
2707 if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, traceLen);
2708 }
2709
2710
2711
2712 //-----------------------------------------------------------------------------
2713 // MIFARE sniffer.
2714 //
2715 //-----------------------------------------------------------------------------
2716 void RAMFUNC SniffMifare(uint8_t param) {
2717 // param:
2718 // bit 0 - trigger from first card answer
2719 // bit 1 - trigger from first reader 7-bit request
2720
2721 // C(red) A(yellow) B(green)
2722 LEDsoff();
2723 // init trace buffer
2724 iso14a_clear_trace();
2725 iso14a_set_tracing(TRUE);
2726
2727 // The command (reader -> tag) that we're receiving.
2728 // The length of a received command will in most cases be no more than 18 bytes.
2729 // So 32 should be enough!
2730 uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
2731 uint8_t *receivedCmdPar = ((uint8_t *)BigBuf) + RECV_CMD_PAR_OFFSET;
2732 // The response (tag -> reader) that we're receiving.
2733 uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RESP_OFFSET);
2734 uint8_t *receivedResponsePar = ((uint8_t *)BigBuf) + RECV_RESP_PAR_OFFSET;
2735
2736 // As we receive stuff, we copy it from receivedCmd or receivedResponse
2737 // into trace, along with its length and other annotations.
2738 //uint8_t *trace = (uint8_t *)BigBuf;
2739
2740 // The DMA buffer, used to stream samples from the FPGA
2741 uint8_t *dmaBuf = ((uint8_t *)BigBuf) + DMA_BUFFER_OFFSET;
2742 uint8_t *data = dmaBuf;
2743 uint8_t previous_data = 0;
2744 int maxDataLen = 0;
2745 int dataLen = 0;
2746 bool ReaderIsActive = FALSE;
2747 bool TagIsActive = FALSE;
2748
2749 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
2750
2751 // Set up the demodulator for tag -> reader responses.
2752 DemodInit(receivedResponse, receivedResponsePar);
2753
2754 // Set up the demodulator for the reader -> tag commands
2755 UartInit(receivedCmd, receivedCmdPar);
2756
2757 // Setup for the DMA.
2758 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2759
2760 LED_D_OFF();
2761
2762 // init sniffer
2763 MfSniffInit();
2764
2765 // And now we loop, receiving samples.
2766 for(uint32_t sniffCounter = 0; TRUE; ) {
2767
2768 if(BUTTON_PRESS()) {
2769 DbpString("cancelled by button");
2770 break;
2771 }
2772
2773 LED_A_ON();
2774 WDT_HIT();
2775
2776 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
2777 // check if a transaction is completed (timeout after 2000ms).
2778 // if yes, stop the DMA transfer and send what we have so far to the client
2779 if (MfSniffSend(2000)) {
2780 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
2781 sniffCounter = 0;
2782 data = dmaBuf;
2783 maxDataLen = 0;
2784 ReaderIsActive = FALSE;
2785 TagIsActive = FALSE;
2786 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2787 }
2788 }
2789
2790 int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
2791 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
2792 if (readBufDataP <= dmaBufDataP){ // we are processing the same block of data which is currently being transferred
2793 dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
2794 } else {
2795 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
2796 }
2797 // test for length of buffer
2798 if(dataLen > maxDataLen) { // we are more behind than ever...
2799 maxDataLen = dataLen;
2800 if(dataLen > 400) {
2801 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
2802 break;
2803 }
2804 }
2805 if(dataLen < 1) continue;
2806
2807 // primary buffer was stopped ( <-- we lost data!
2808 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
2809 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
2810 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
2811 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
2812 }
2813 // secondary buffer sets as primary, secondary buffer was stopped
2814 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
2815 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
2816 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
2817 }
2818
2819 LED_A_OFF();
2820
2821 if (sniffCounter & 0x01) {
2822
2823 if(!TagIsActive) { // no need to try decoding tag data if the reader is sending
2824 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
2825 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
2826 LED_C_INV();
2827 if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
2828
2829 /* And ready to receive another command. */
2830 UartReset();
2831
2832 /* And also reset the demod code */
2833 DemodReset();
2834 }
2835 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
2836 }
2837
2838 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending
2839 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
2840 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
2841 LED_C_INV();
2842
2843 if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
2844
2845 // And ready to receive another response.
2846 DemodReset();
2847 }
2848 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
2849 }
2850 }
2851
2852 previous_data = *data;
2853 sniffCounter++;
2854 data++;
2855 if(data == dmaBuf + DMA_BUFFER_SIZE) {
2856 data = dmaBuf;
2857 }
2858
2859 } // main cycle
2860
2861 DbpString("COMMAND FINISHED");
2862
2863 FpgaDisableSscDma();
2864 MfSniffEnd();
2865
2866 Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
2867 LEDsoff();
2868 }
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