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