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1 //-----------------------------------------------------------------------------
2 // Merlok - June 2011, 2012
3 // Gerhard de Koning Gans - May 2008
4 // Hagen Fritsch - June 2010
5 //
6 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
7 // at your option, any later version. See the LICENSE.txt file for the text of
8 // the license.
9 //-----------------------------------------------------------------------------
10 // Routines to support ISO 14443 type A.
11 //-----------------------------------------------------------------------------
12
13 #include "proxmark3.h"
14 #include "apps.h"
15 #include "util.h"
16 #include "string.h"
17 #include "cmd.h"
18
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 uint32_t NextTransferTime;
108 uint32_t LastTimeProxToAirStart;
109 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
148 void iso14a_set_trigger(bool enable) {
149 trigger = enable;
150 }
151
152 void iso14a_clear_trace() {
153 memset(trace, 0x44, TRACE_SIZE);
154 traceLen = 0;
155 }
156
157 void iso14a_set_tracing(bool enable) {
158 tracing = enable;
159 }
160
161 void iso14a_set_timeout(uint32_t timeout) {
162 iso14a_timeout = timeout;
163 }
164
165 //-----------------------------------------------------------------------------
166 // Generate the parity value for a byte sequence
167 //
168 //-----------------------------------------------------------------------------
169 byte_t oddparity (const byte_t bt)
170 {
171 return OddByteParity[bt];
172 }
173
174 uint32_t GetParity(const uint8_t * pbtCmd, int iLen)
175 {
176 int i;
177 uint32_t dwPar = 0;
178
179 // Generate the parity bits
180 for (i = 0; i < iLen; i++) {
181 // and save them to a 32Bit word
182 dwPar |= ((OddByteParity[pbtCmd[i]]) << i);
183 }
184 return dwPar;
185 }
186
187 void AppendCrc14443a(uint8_t* data, int len)
188 {
189 ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
190 }
191
192 // The function LogTrace() is also used by the iClass implementation in iClass.c
193 bool RAMFUNC LogTrace(const uint8_t * btBytes, uint8_t iLen, uint32_t timestamp, uint32_t dwParity, bool readerToTag)
194 {
195 if (!tracing) return FALSE;
196 // Return when trace is full
197 if (traceLen + sizeof(timestamp) + sizeof(dwParity) + iLen >= TRACE_SIZE) {
198 tracing = FALSE; // don't trace any more
199 return FALSE;
200 }
201
202 // Trace the random, i'm curious
203 trace[traceLen++] = ((timestamp >> 0) & 0xff);
204 trace[traceLen++] = ((timestamp >> 8) & 0xff);
205 trace[traceLen++] = ((timestamp >> 16) & 0xff);
206 trace[traceLen++] = ((timestamp >> 24) & 0xff);
207
208 if (!readerToTag) {
209 trace[traceLen - 1] |= 0x80;
210 }
211 trace[traceLen++] = ((dwParity >> 0) & 0xff);
212 trace[traceLen++] = ((dwParity >> 8) & 0xff);
213 trace[traceLen++] = ((dwParity >> 16) & 0xff);
214 trace[traceLen++] = ((dwParity >> 24) & 0xff);
215 trace[traceLen++] = iLen;
216 if (btBytes != NULL && iLen != 0) {
217 memcpy(trace + traceLen, btBytes, iLen);
218 }
219 traceLen += iLen;
220 return TRUE;
221 }
222
223 //=============================================================================
224 // ISO 14443 Type A - Miller decoder
225 //=============================================================================
226 // Basics:
227 // This decoder is used when the PM3 acts as a tag.
228 // The reader will generate "pauses" by temporarily switching of the field.
229 // At the PM3 antenna we will therefore measure a modulated antenna voltage.
230 // The FPGA does a comparison with a threshold and would deliver e.g.:
231 // ........ 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 .......
232 // The Miller decoder needs to identify the following sequences:
233 // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0")
234 // 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information")
235 // 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1")
236 // Note 1: the bitstream may start at any time. We therefore need to sync.
237 // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
238 //-----------------------------------------------------------------------------
239 static tUart Uart;
240
241 // Lookup-Table to decide if 4 raw bits are a modulation.
242 // We accept two or three consecutive "0" in any position with the rest "1"
243 const bool Mod_Miller_LUT[] = {
244 TRUE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, FALSE,
245 TRUE, TRUE, FALSE, FALSE, TRUE, FALSE, FALSE, FALSE
246 };
247 #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x00F0) >> 4])
248 #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x000F)])
249
250 void UartReset()
251 {
252 Uart.state = STATE_UNSYNCD;
253 Uart.bitCount = 0;
254 Uart.len = 0; // number of decoded data bytes
255 Uart.shiftReg = 0; // shiftreg to hold decoded data bits
256 Uart.parityBits = 0; //
257 Uart.twoBits = 0x0000; // buffer for 2 Bits
258 Uart.highCnt = 0;
259 Uart.startTime = 0;
260 Uart.endTime = 0;
261 }
262
263
264 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
265 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
266 {
267
268 Uart.twoBits = (Uart.twoBits << 8) | bit;
269
270 if (Uart.state == STATE_UNSYNCD) { // not yet synced
271 if (Uart.highCnt < 7) { // wait for a stable unmodulated signal
272 if (Uart.twoBits == 0xffff) {
273 Uart.highCnt++;
274 } else {
275 Uart.highCnt = 0;
276 }
277 } else {
278 Uart.syncBit = 0xFFFF; // not set
279 // look for 00xx1111 (the start bit)
280 if ((Uart.twoBits & 0x6780) == 0x0780) Uart.syncBit = 7;
281 else if ((Uart.twoBits & 0x33C0) == 0x03C0) Uart.syncBit = 6;
282 else if ((Uart.twoBits & 0x19E0) == 0x01E0) Uart.syncBit = 5;
283 else if ((Uart.twoBits & 0x0CF0) == 0x00F0) Uart.syncBit = 4;
284 else if ((Uart.twoBits & 0x0678) == 0x0078) Uart.syncBit = 3;
285 else if ((Uart.twoBits & 0x033C) == 0x003C) Uart.syncBit = 2;
286 else if ((Uart.twoBits & 0x019E) == 0x001E) Uart.syncBit = 1;
287 else if ((Uart.twoBits & 0x00CF) == 0x000F) Uart.syncBit = 0;
288 if (Uart.syncBit != 0xFFFF) {
289 Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
290 Uart.startTime -= Uart.syncBit;
291 Uart.endTime = Uart.startTime;
292 Uart.state = STATE_START_OF_COMMUNICATION;
293 }
294 }
295
296 } else {
297
298 if (IsMillerModulationNibble1(Uart.twoBits >> Uart.syncBit)) {
299 if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation in both halves - error
300 UartReset();
301 Uart.highCnt = 6;
302 } else { // Modulation in first half = Sequence Z = logic "0"
303 if (Uart.state == STATE_MILLER_X) { // error - must not follow after X
304 UartReset();
305 Uart.highCnt = 6;
306 } else {
307 Uart.bitCount++;
308 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
309 Uart.state = STATE_MILLER_Z;
310 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
311 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
312 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
313 Uart.parityBits <<= 1; // make room for the parity bit
314 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
315 Uart.bitCount = 0;
316 Uart.shiftReg = 0;
317 }
318 }
319 }
320 } else {
321 if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1"
322 Uart.bitCount++;
323 Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg
324 Uart.state = STATE_MILLER_X;
325 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
326 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
327 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
328 Uart.parityBits <<= 1; // make room for the new parity bit
329 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
330 Uart.bitCount = 0;
331 Uart.shiftReg = 0;
332 }
333 } else { // no modulation in both halves - Sequence Y
334 if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication
335 Uart.state = STATE_UNSYNCD;
336 if(Uart.len == 0 && Uart.bitCount > 0) { // if we decoded some bits
337 Uart.shiftReg >>= (9 - Uart.bitCount); // add them to the output
338 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
339 Uart.parityBits <<= 1; // no parity bit - add "0"
340 Uart.bitCount--; // last "0" was part of the EOC sequence
341 }
342 return TRUE;
343 }
344 if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC
345 UartReset();
346 Uart.highCnt = 6;
347 } else { // a logic "0"
348 Uart.bitCount++;
349 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
350 Uart.state = STATE_MILLER_Y;
351 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
352 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
353 Uart.parityBits <<= 1; // make room for the parity bit
354 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
355 Uart.bitCount = 0;
356 Uart.shiftReg = 0;
357 }
358 }
359 }
360 }
361
362 }
363
364 return FALSE; // not finished yet, need more data
365 }
366
367
368
369 //=============================================================================
370 // ISO 14443 Type A - Manchester decoder
371 //=============================================================================
372 // Basics:
373 // This decoder is used when the PM3 acts as a reader.
374 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
375 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
376 // ........ 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 .......
377 // The Manchester decoder needs to identify the following sequences:
378 // 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication")
379 // 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0
380 // 8 ticks unmodulated: Sequence F = end of communication
381 // 8 ticks modulated: A collision. Save the collision position and treat as Sequence D
382 // Note 1: the bitstream may start at any time. We therefore need to sync.
383 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
384 static tDemod Demod;
385
386 // Lookup-Table to decide if 4 raw bits are a modulation.
387 // We accept three or four "1" in any position
388 const bool Mod_Manchester_LUT[] = {
389 FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
390 FALSE, FALSE, FALSE, TRUE, FALSE, TRUE, TRUE, TRUE
391 };
392
393 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
394 #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
395
396
397 void DemodReset()
398 {
399 Demod.state = DEMOD_UNSYNCD;
400 Demod.len = 0; // number of decoded data bytes
401 Demod.shiftReg = 0; // shiftreg to hold decoded data bits
402 Demod.parityBits = 0; //
403 Demod.collisionPos = 0; // Position of collision bit
404 Demod.twoBits = 0xffff; // buffer for 2 Bits
405 Demod.highCnt = 0;
406 Demod.startTime = 0;
407 Demod.endTime = 0;
408 }
409
410 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
411 static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
412 {
413
414 Demod.twoBits = (Demod.twoBits << 8) | bit;
415
416 if (Demod.state == DEMOD_UNSYNCD) {
417
418 if (Demod.highCnt < 2) { // wait for a stable unmodulated signal
419 if (Demod.twoBits == 0x0000) {
420 Demod.highCnt++;
421 } else {
422 Demod.highCnt = 0;
423 }
424 } else {
425 Demod.syncBit = 0xFFFF; // not set
426 if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
427 else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
428 else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
429 else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
430 else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
431 else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
432 else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
433 else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
434 if (Demod.syncBit != 0xFFFF) {
435 Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
436 Demod.startTime -= Demod.syncBit;
437 Demod.bitCount = offset; // number of decoded data bits
438 Demod.state = DEMOD_MANCHESTER_DATA;
439 }
440 }
441
442 } else {
443
444 if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half
445 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... and in second half = collision
446 if (!Demod.collisionPos) {
447 Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
448 }
449 } // modulation in first half only - Sequence D = 1
450 Demod.bitCount++;
451 Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg
452 if(Demod.bitCount == 9) { // if we decoded a full byte (including parity)
453 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
454 Demod.parityBits <<= 1; // make room for the parity bit
455 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
456 Demod.bitCount = 0;
457 Demod.shiftReg = 0;
458 }
459 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
460 } else { // no modulation in first half
461 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // and modulation in second half = Sequence E = 0
462 Demod.bitCount++;
463 Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg
464 if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity)
465 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
466 Demod.parityBits <<= 1; // make room for the new parity bit
467 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
468 Demod.bitCount = 0;
469 Demod.shiftReg = 0;
470 }
471 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
472 } else { // no modulation in both halves - End of communication
473 if (Demod.len > 0 || Demod.bitCount > 0) { // received something
474 if(Demod.bitCount > 0) { // if we decoded bits
475 Demod.shiftReg >>= (9 - Demod.bitCount); // add the remaining decoded bits to the output
476 Demod.output[Demod.len++] = Demod.shiftReg & 0xff;
477 // No parity bit, so just shift a 0
478 Demod.parityBits <<= 1;
479 }
480 return TRUE; // we are finished with decoding the raw data sequence
481 } else { // nothing received. Start over
482 DemodReset();
483 }
484 }
485 }
486
487 }
488
489 return FALSE; // not finished yet, need more data
490 }
491
492 //=============================================================================
493 // Finally, a `sniffer' for ISO 14443 Type A
494 // Both sides of communication!
495 //=============================================================================
496
497 //-----------------------------------------------------------------------------
498 // Record the sequence of commands sent by the reader to the tag, with
499 // triggering so that we start recording at the point that the tag is moved
500 // near the reader.
501 //-----------------------------------------------------------------------------
502 void RAMFUNC SnoopIso14443a(uint8_t param) {
503 // param:
504 // bit 0 - trigger from first card answer
505 // bit 1 - trigger from first reader 7-bit request
506
507 LEDsoff();
508 // init trace buffer
509 iso14a_clear_trace();
510 iso14a_set_tracing(TRUE);
511
512 // We won't start recording the frames that we acquire until we trigger;
513 // a good trigger condition to get started is probably when we see a
514 // response from the tag.
515 // triggered == FALSE -- to wait first for card
516 bool triggered = !(param & 0x03);
517
518 // The command (reader -> tag) that we're receiving.
519 // The length of a received command will in most cases be no more than 18 bytes.
520 // So 32 should be enough!
521 uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
522 // The response (tag -> reader) that we're receiving.
523 uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
524
525 // As we receive stuff, we copy it from receivedCmd or receivedResponse
526 // into trace, along with its length and other annotations.
527 //uint8_t *trace = (uint8_t *)BigBuf;
528
529 // The DMA buffer, used to stream samples from the FPGA
530 uint8_t *dmaBuf = ((uint8_t *)BigBuf) + DMA_BUFFER_OFFSET;
531 uint8_t *data = dmaBuf;
532 uint8_t previous_data = 0;
533 int maxDataLen = 0;
534 int dataLen = 0;
535 bool TagIsActive = FALSE;
536 bool ReaderIsActive = FALSE;
537
538 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
539
540 // Set up the demodulator for tag -> reader responses.
541 Demod.output = receivedResponse;
542
543 // Set up the demodulator for the reader -> tag commands
544 Uart.output = receivedCmd;
545
546 // Setup and start DMA.
547 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
548
549 // And now we loop, receiving samples.
550 for(uint32_t rsamples = 0; TRUE; ) {
551
552 if(BUTTON_PRESS()) {
553 DbpString("cancelled by button");
554 break;
555 }
556
557 LED_A_ON();
558 WDT_HIT();
559
560 int register readBufDataP = data - dmaBuf;
561 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
562 if (readBufDataP <= dmaBufDataP){
563 dataLen = dmaBufDataP - readBufDataP;
564 } else {
565 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
566 }
567 // test for length of buffer
568 if(dataLen > maxDataLen) {
569 maxDataLen = dataLen;
570 if(dataLen > 400) {
571 Dbprintf("blew circular buffer! dataLen=%d", dataLen);
572 break;
573 }
574 }
575 if(dataLen < 1) continue;
576
577 // primary buffer was stopped( <-- we lost data!
578 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
579 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
580 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
581 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
582 }
583 // secondary buffer sets as primary, secondary buffer was stopped
584 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
585 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
586 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
587 }
588
589 LED_A_OFF();
590
591 if (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder
592
593 if(!TagIsActive) { // no need to try decoding reader data if the tag is sending
594 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
595 if (MillerDecoding(readerdata, (rsamples-1)*4)) {
596 LED_C_ON();
597
598 // check - if there is a short 7bit request from reader
599 if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
600
601 if(triggered) {
602 if (!LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, Uart.parityBits, TRUE)) break;
603 if (!LogTrace(NULL, 0, Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, 0, TRUE)) break;
604 }
605 /* And ready to receive another command. */
606 UartReset();
607 /* And also reset the demod code, which might have been */
608 /* false-triggered by the commands from the reader. */
609 DemodReset();
610 LED_B_OFF();
611 }
612 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
613 }
614
615 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time
616 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
617 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
618 LED_B_ON();
619
620 if (!LogTrace(receivedResponse, Demod.len, Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, Demod.parityBits, FALSE)) break;
621 if (!LogTrace(NULL, 0, Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, 0, FALSE)) break;
622
623 if ((!triggered) && (param & 0x01)) triggered = TRUE;
624
625 // And ready to receive another response.
626 DemodReset();
627 LED_C_OFF();
628 }
629 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
630 }
631 }
632
633 previous_data = *data;
634 rsamples++;
635 data++;
636 if(data == dmaBuf + DMA_BUFFER_SIZE) {
637 data = dmaBuf;
638 }
639 } // main cycle
640
641 DbpString("COMMAND FINISHED");
642
643 FpgaDisableSscDma();
644 Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
645 Dbprintf("traceLen=%d, Uart.output[0]=%08x", traceLen, (uint32_t)Uart.output[0]);
646 LEDsoff();
647 }
648
649 //-----------------------------------------------------------------------------
650 // Prepare tag messages
651 //-----------------------------------------------------------------------------
652 static void CodeIso14443aAsTagPar(const uint8_t *cmd, int len, uint32_t dwParity)
653 {
654 int i;
655
656 ToSendReset();
657
658 // Correction bit, might be removed when not needed
659 ToSendStuffBit(0);
660 ToSendStuffBit(0);
661 ToSendStuffBit(0);
662 ToSendStuffBit(0);
663 ToSendStuffBit(1); // 1
664 ToSendStuffBit(0);
665 ToSendStuffBit(0);
666 ToSendStuffBit(0);
667
668 // Send startbit
669 ToSend[++ToSendMax] = SEC_D;
670 LastProxToAirDuration = 8 * ToSendMax - 4;
671
672 for(i = 0; i < len; i++) {
673 int j;
674 uint8_t b = cmd[i];
675
676 // Data bits
677 for(j = 0; j < 8; j++) {
678 if(b & 1) {
679 ToSend[++ToSendMax] = SEC_D;
680 } else {
681 ToSend[++ToSendMax] = SEC_E;
682 }
683 b >>= 1;
684 }
685
686 // Get the parity bit
687 if ((dwParity >> i) & 0x01) {
688 ToSend[++ToSendMax] = SEC_D;
689 LastProxToAirDuration = 8 * ToSendMax - 4;
690 } else {
691 ToSend[++ToSendMax] = SEC_E;
692 LastProxToAirDuration = 8 * ToSendMax;
693 }
694 }
695
696 // Send stopbit
697 ToSend[++ToSendMax] = SEC_F;
698
699 // Convert from last byte pos to length
700 ToSendMax++;
701 }
702
703 static void CodeIso14443aAsTag(const uint8_t *cmd, int len){
704 CodeIso14443aAsTagPar(cmd, len, GetParity(cmd, len));
705 }
706
707
708 static void Code4bitAnswerAsTag(uint8_t cmd)
709 {
710 int i;
711
712 ToSendReset();
713
714 // Correction bit, might be removed when not needed
715 ToSendStuffBit(0);
716 ToSendStuffBit(0);
717 ToSendStuffBit(0);
718 ToSendStuffBit(0);
719 ToSendStuffBit(1); // 1
720 ToSendStuffBit(0);
721 ToSendStuffBit(0);
722 ToSendStuffBit(0);
723
724 // Send startbit
725 ToSend[++ToSendMax] = SEC_D;
726
727 uint8_t b = cmd;
728 for(i = 0; i < 4; i++) {
729 if(b & 1) {
730 ToSend[++ToSendMax] = SEC_D;
731 LastProxToAirDuration = 8 * ToSendMax - 4;
732 } else {
733 ToSend[++ToSendMax] = SEC_E;
734 LastProxToAirDuration = 8 * ToSendMax;
735 }
736 b >>= 1;
737 }
738
739 // Send stopbit
740 ToSend[++ToSendMax] = SEC_F;
741
742 // Convert from last byte pos to length
743 ToSendMax++;
744 }
745
746 //-----------------------------------------------------------------------------
747 // Wait for commands from reader
748 // Stop when button is pressed
749 // Or return TRUE when command is captured
750 //-----------------------------------------------------------------------------
751 static int GetIso14443aCommandFromReader(uint8_t *received, int *len, int maxLen)
752 {
753 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
754 // only, since we are receiving, not transmitting).
755 // Signal field is off with the appropriate LED
756 LED_D_OFF();
757 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
758
759 // Now run a `software UART' on the stream of incoming samples.
760 UartReset();
761 Uart.output = received;
762
763 // clear RXRDY:
764 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
765
766 for(;;) {
767 WDT_HIT();
768
769 if(BUTTON_PRESS()) return FALSE;
770
771 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
772 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
773 if(MillerDecoding(b, 0)) {
774 *len = Uart.len;
775 return TRUE;
776 }
777 }
778 }
779 }
780
781 static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, bool correctionNeeded);
782 int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
783 int EmSend4bit(uint8_t resp);
784 int EmSendCmdExPar(uint8_t *resp, int respLen, bool correctionNeeded, uint32_t par);
785 int EmSendCmdExPar(uint8_t *resp, int respLen, bool correctionNeeded, uint32_t par);
786 int EmSendCmdEx(uint8_t *resp, int respLen, bool correctionNeeded);
787 int EmSendCmd(uint8_t *resp, int respLen);
788 int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par);
789 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint32_t reader_Parity,
790 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint32_t tag_Parity);
791
792 static uint8_t* free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
793
794 typedef struct {
795 uint8_t* response;
796 size_t response_n;
797 uint8_t* modulation;
798 size_t modulation_n;
799 uint32_t ProxToAirDuration;
800 } tag_response_info_t;
801
802 void reset_free_buffer() {
803 free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
804 }
805
806 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
807 // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
808 // This will need the following byte array for a modulation sequence
809 // 144 data bits (18 * 8)
810 // 18 parity bits
811 // 2 Start and stop
812 // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA)
813 // 1 just for the case
814 // ----------- +
815 // 166 bytes, since every bit that needs to be send costs us a byte
816 //
817
818 // Prepare the tag modulation bits from the message
819 CodeIso14443aAsTag(response_info->response,response_info->response_n);
820
821 // Make sure we do not exceed the free buffer space
822 if (ToSendMax > max_buffer_size) {
823 Dbprintf("Out of memory, when modulating bits for tag answer:");
824 Dbhexdump(response_info->response_n,response_info->response,false);
825 return false;
826 }
827
828 // Copy the byte array, used for this modulation to the buffer position
829 memcpy(response_info->modulation,ToSend,ToSendMax);
830
831 // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
832 response_info->modulation_n = ToSendMax;
833 response_info->ProxToAirDuration = LastProxToAirDuration;
834
835 return true;
836 }
837
838 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
839 // Retrieve and store the current buffer index
840 response_info->modulation = free_buffer_pointer;
841
842 // Determine the maximum size we can use from our buffer
843 size_t max_buffer_size = (((uint8_t *)BigBuf)+FREE_BUFFER_OFFSET+FREE_BUFFER_SIZE)-free_buffer_pointer;
844
845 // Forward the prepare tag modulation function to the inner function
846 if (prepare_tag_modulation(response_info,max_buffer_size)) {
847 // Update the free buffer offset
848 free_buffer_pointer += ToSendMax;
849 return true;
850 } else {
851 return false;
852 }
853 }
854
855 //-----------------------------------------------------------------------------
856 // Main loop of simulated tag: receive commands from reader, decide what
857 // response to send, and send it.
858 //-----------------------------------------------------------------------------
859 void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
860 {
861 // Enable and clear the trace
862 iso14a_clear_trace();
863 iso14a_set_tracing(TRUE);
864
865 uint8_t sak;
866
867 // The first response contains the ATQA (note: bytes are transmitted in reverse order).
868 uint8_t response1[2];
869
870 switch (tagType) {
871 case 1: { // MIFARE Classic
872 // Says: I am Mifare 1k - original line
873 response1[0] = 0x04;
874 response1[1] = 0x00;
875 sak = 0x08;
876 } break;
877 case 2: { // MIFARE Ultralight
878 // Says: I am a stupid memory tag, no crypto
879 response1[0] = 0x04;
880 response1[1] = 0x00;
881 sak = 0x00;
882 } break;
883 case 3: { // MIFARE DESFire
884 // Says: I am a DESFire tag, ph33r me
885 response1[0] = 0x04;
886 response1[1] = 0x03;
887 sak = 0x20;
888 } break;
889 case 4: { // ISO/IEC 14443-4
890 // Says: I am a javacard (JCOP)
891 response1[0] = 0x04;
892 response1[1] = 0x00;
893 sak = 0x28;
894 } break;
895 default: {
896 Dbprintf("Error: unkown tagtype (%d)",tagType);
897 return;
898 } break;
899 }
900
901 // The second response contains the (mandatory) first 24 bits of the UID
902 uint8_t response2[5];
903
904 // Check if the uid uses the (optional) part
905 uint8_t response2a[5];
906 if (uid_2nd) {
907 response2[0] = 0x88;
908 num_to_bytes(uid_1st,3,response2+1);
909 num_to_bytes(uid_2nd,4,response2a);
910 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
911
912 // Configure the ATQA and SAK accordingly
913 response1[0] |= 0x40;
914 sak |= 0x04;
915 } else {
916 num_to_bytes(uid_1st,4,response2);
917 // Configure the ATQA and SAK accordingly
918 response1[0] &= 0xBF;
919 sak &= 0xFB;
920 }
921
922 // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
923 response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
924
925 // Prepare the mandatory SAK (for 4 and 7 byte UID)
926 uint8_t response3[3];
927 response3[0] = sak;
928 ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
929
930 // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
931 uint8_t response3a[3];
932 response3a[0] = sak & 0xFB;
933 ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
934
935 uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
936 uint8_t response6[] = { 0x04, 0x58, 0x00, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS
937 ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
938
939 #define TAG_RESPONSE_COUNT 7
940 tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
941 { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type
942 { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid
943 { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked
944 { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1
945 { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2
946 { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce)
947 { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS
948 };
949
950 // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
951 // Such a response is less time critical, so we can prepare them on the fly
952 #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
953 #define DYNAMIC_MODULATION_BUFFER_SIZE 512
954 uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
955 uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
956 tag_response_info_t dynamic_response_info = {
957 .response = dynamic_response_buffer,
958 .response_n = 0,
959 .modulation = dynamic_modulation_buffer,
960 .modulation_n = 0
961 };
962
963 // Reset the offset pointer of the free buffer
964 reset_free_buffer();
965
966 // Prepare the responses of the anticollision phase
967 // there will be not enough time to do this at the moment the reader sends it REQA
968 for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
969 prepare_allocated_tag_modulation(&responses[i]);
970 }
971
972 uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
973 int len = 0;
974
975 // To control where we are in the protocol
976 int order = 0;
977 int lastorder;
978
979 // Just to allow some checks
980 int happened = 0;
981 int happened2 = 0;
982 int cmdsRecvd = 0;
983
984 // We need to listen to the high-frequency, peak-detected path.
985 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
986
987 cmdsRecvd = 0;
988 tag_response_info_t* p_response;
989
990 LED_A_ON();
991 for(;;) {
992 // Clean receive command buffer
993
994 if(!GetIso14443aCommandFromReader(receivedCmd, &len, RECV_CMD_SIZE)) {
995 DbpString("Button press");
996 break;
997 }
998
999 p_response = NULL;
1000
1001 // doob - added loads of debug strings so we can see what the reader is saying to us during the sim as hi14alist is not populated
1002 // Okay, look at the command now.
1003 lastorder = order;
1004 if(receivedCmd[0] == 0x26) { // Received a REQUEST
1005 p_response = &responses[0]; order = 1;
1006 } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
1007 p_response = &responses[0]; order = 6;
1008 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // Received request for UID (cascade 1)
1009 p_response = &responses[1]; order = 2;
1010 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2)
1011 p_response = &responses[2]; order = 20;
1012 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) { // Received a SELECT (cascade 1)
1013 p_response = &responses[3]; order = 3;
1014 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) { // Received a SELECT (cascade 2)
1015 p_response = &responses[4]; order = 30;
1016 } else if(receivedCmd[0] == 0x30) { // Received a (plain) READ
1017 EmSendCmdEx(data+(4*receivedCmd[0]),16,false);
1018 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1019 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1020 p_response = NULL;
1021 } else if(receivedCmd[0] == 0x50) { // Received a HALT
1022 // DbpString("Reader requested we HALT!:");
1023 if (tracing) {
1024 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
1025 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
1026 }
1027 p_response = NULL;
1028 } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) { // Received an authentication request
1029 p_response = &responses[5]; order = 7;
1030 } else if(receivedCmd[0] == 0xE0) { // Received a RATS request
1031 if (tagType == 1 || tagType == 2) { // RATS not supported
1032 EmSend4bit(CARD_NACK_NA);
1033 p_response = NULL;
1034 } else {
1035 p_response = &responses[6]; order = 70;
1036 }
1037 } else if (order == 7 && len == 8) { // Received authentication request
1038 if (tracing) {
1039 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
1040 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
1041 }
1042 uint32_t nr = bytes_to_num(receivedCmd,4);
1043 uint32_t ar = bytes_to_num(receivedCmd+4,4);
1044 Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar);
1045 } else {
1046 // Check for ISO 14443A-4 compliant commands, look at left nibble
1047 switch (receivedCmd[0]) {
1048
1049 case 0x0B:
1050 case 0x0A: { // IBlock (command)
1051 dynamic_response_info.response[0] = receivedCmd[0];
1052 dynamic_response_info.response[1] = 0x00;
1053 dynamic_response_info.response[2] = 0x90;
1054 dynamic_response_info.response[3] = 0x00;
1055 dynamic_response_info.response_n = 4;
1056 } break;
1057
1058 case 0x1A:
1059 case 0x1B: { // Chaining command
1060 dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1061 dynamic_response_info.response_n = 2;
1062 } break;
1063
1064 case 0xaa:
1065 case 0xbb: {
1066 dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1067 dynamic_response_info.response_n = 2;
1068 } break;
1069
1070 case 0xBA: { //
1071 memcpy(dynamic_response_info.response,"\xAB\x00",2);
1072 dynamic_response_info.response_n = 2;
1073 } break;
1074
1075 case 0xCA:
1076 case 0xC2: { // Readers sends deselect command
1077 memcpy(dynamic_response_info.response,"\xCA\x00",2);
1078 dynamic_response_info.response_n = 2;
1079 } break;
1080
1081 default: {
1082 // Never seen this command before
1083 if (tracing) {
1084 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
1085 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
1086 }
1087 Dbprintf("Received unknown command (len=%d):",len);
1088 Dbhexdump(len,receivedCmd,false);
1089 // Do not respond
1090 dynamic_response_info.response_n = 0;
1091 } break;
1092 }
1093
1094 if (dynamic_response_info.response_n > 0) {
1095 // Copy the CID from the reader query
1096 dynamic_response_info.response[1] = receivedCmd[1];
1097
1098 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1099 AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
1100 dynamic_response_info.response_n += 2;
1101
1102 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1103 Dbprintf("Error preparing tag response");
1104 if (tracing) {
1105 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
1106 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
1107 }
1108 break;
1109 }
1110 p_response = &dynamic_response_info;
1111 }
1112 }
1113
1114 // Count number of wakeups received after a halt
1115 if(order == 6 && lastorder == 5) { happened++; }
1116
1117 // Count number of other messages after a halt
1118 if(order != 6 && lastorder == 5) { happened2++; }
1119
1120 if(cmdsRecvd > 999) {
1121 DbpString("1000 commands later...");
1122 break;
1123 }
1124 cmdsRecvd++;
1125
1126 if (p_response != NULL) {
1127 EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1128 // do the tracing for the previous reader request and this tag answer:
1129 EmLogTrace(Uart.output,
1130 Uart.len,
1131 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1132 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1133 Uart.parityBits,
1134 p_response->response,
1135 p_response->response_n,
1136 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1137 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1138 SwapBits(GetParity(p_response->response, p_response->response_n), p_response->response_n));
1139 }
1140
1141 if (!tracing) {
1142 Dbprintf("Trace Full. Simulation stopped.");
1143 break;
1144 }
1145 }
1146
1147 Dbprintf("%x %x %x", happened, happened2, cmdsRecvd);
1148 LED_A_OFF();
1149 }
1150
1151
1152 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1153 // of bits specified in the delay parameter.
1154 void PrepareDelayedTransfer(uint16_t delay)
1155 {
1156 uint8_t bitmask = 0;
1157 uint8_t bits_to_shift = 0;
1158 uint8_t bits_shifted = 0;
1159
1160 delay &= 0x07;
1161 if (delay) {
1162 for (uint16_t i = 0; i < delay; i++) {
1163 bitmask |= (0x01 << i);
1164 }
1165 ToSend[ToSendMax++] = 0x00;
1166 for (uint16_t i = 0; i < ToSendMax; i++) {
1167 bits_to_shift = ToSend[i] & bitmask;
1168 ToSend[i] = ToSend[i] >> delay;
1169 ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1170 bits_shifted = bits_to_shift;
1171 }
1172 }
1173 }
1174
1175
1176 //-------------------------------------------------------------------------------------
1177 // Transmit the command (to the tag) that was placed in ToSend[].
1178 // Parameter timing:
1179 // if NULL: transfer at next possible time, taking into account
1180 // request guard time and frame delay time
1181 // if == 0: transfer immediately and return time of transfer
1182 // if != 0: delay transfer until time specified
1183 //-------------------------------------------------------------------------------------
1184 static void TransmitFor14443a(const uint8_t *cmd, int len, uint32_t *timing)
1185 {
1186
1187 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1188
1189 uint32_t ThisTransferTime = 0;
1190
1191 if (timing) {
1192 if(*timing == 0) { // Measure time
1193 *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1194 } else {
1195 PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
1196 }
1197 if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
1198 while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
1199 LastTimeProxToAirStart = *timing;
1200 } else {
1201 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1202 while(GetCountSspClk() < ThisTransferTime);
1203 LastTimeProxToAirStart = ThisTransferTime;
1204 }
1205
1206 // clear TXRDY
1207 AT91C_BASE_SSC->SSC_THR = SEC_Y;
1208
1209 // for(uint16_t c = 0; c < 10;) { // standard delay for each transfer (allow tag to be ready after last transmission)
1210 // if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1211 // AT91C_BASE_SSC->SSC_THR = SEC_Y;
1212 // c++;
1213 // }
1214 // }
1215
1216 uint16_t c = 0;
1217 for(;;) {
1218 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1219 AT91C_BASE_SSC->SSC_THR = cmd[c];
1220 c++;
1221 if(c >= len) {
1222 break;
1223 }
1224 }
1225 }
1226
1227 NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1228
1229 }
1230
1231
1232 //-----------------------------------------------------------------------------
1233 // Prepare reader command (in bits, support short frames) to send to FPGA
1234 //-----------------------------------------------------------------------------
1235 void CodeIso14443aBitsAsReaderPar(const uint8_t * cmd, int bits, uint32_t dwParity)
1236 {
1237 int i, j;
1238 int last;
1239 uint8_t b;
1240
1241 ToSendReset();
1242
1243 // Start of Communication (Seq. Z)
1244 ToSend[++ToSendMax] = SEC_Z;
1245 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1246 last = 0;
1247
1248 size_t bytecount = nbytes(bits);
1249 // Generate send structure for the data bits
1250 for (i = 0; i < bytecount; i++) {
1251 // Get the current byte to send
1252 b = cmd[i];
1253 size_t bitsleft = MIN((bits-(i*8)),8);
1254
1255 for (j = 0; j < bitsleft; j++) {
1256 if (b & 1) {
1257 // Sequence X
1258 ToSend[++ToSendMax] = SEC_X;
1259 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1260 last = 1;
1261 } else {
1262 if (last == 0) {
1263 // Sequence Z
1264 ToSend[++ToSendMax] = SEC_Z;
1265 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1266 } else {
1267 // Sequence Y
1268 ToSend[++ToSendMax] = SEC_Y;
1269 last = 0;
1270 }
1271 }
1272 b >>= 1;
1273 }
1274
1275 // Only transmit (last) parity bit if we transmitted a complete byte
1276 if (j == 8) {
1277 // Get the parity bit
1278 if ((dwParity >> i) & 0x01) {
1279 // Sequence X
1280 ToSend[++ToSendMax] = SEC_X;
1281 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1282 last = 1;
1283 } else {
1284 if (last == 0) {
1285 // Sequence Z
1286 ToSend[++ToSendMax] = SEC_Z;
1287 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1288 } else {
1289 // Sequence Y
1290 ToSend[++ToSendMax] = SEC_Y;
1291 last = 0;
1292 }
1293 }
1294 }
1295 }
1296
1297 // End of Communication: Logic 0 followed by Sequence Y
1298 if (last == 0) {
1299 // Sequence Z
1300 ToSend[++ToSendMax] = SEC_Z;
1301 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1302 } else {
1303 // Sequence Y
1304 ToSend[++ToSendMax] = SEC_Y;
1305 last = 0;
1306 }
1307 ToSend[++ToSendMax] = SEC_Y;
1308
1309 // Convert to length of command:
1310 ToSendMax++;
1311 }
1312
1313 //-----------------------------------------------------------------------------
1314 // Prepare reader command to send to FPGA
1315 //-----------------------------------------------------------------------------
1316 void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity)
1317 {
1318 CodeIso14443aBitsAsReaderPar(cmd,len*8,dwParity);
1319 }
1320
1321 //-----------------------------------------------------------------------------
1322 // Wait for commands from reader
1323 // Stop when button is pressed (return 1) or field was gone (return 2)
1324 // Or return 0 when command is captured
1325 //-----------------------------------------------------------------------------
1326 static int EmGetCmd(uint8_t *received, int *len)
1327 {
1328 *len = 0;
1329
1330 uint32_t timer = 0, vtime = 0;
1331 int analogCnt = 0;
1332 int analogAVG = 0;
1333
1334 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1335 // only, since we are receiving, not transmitting).
1336 // Signal field is off with the appropriate LED
1337 LED_D_OFF();
1338 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1339
1340 // Set ADC to read field strength
1341 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1342 AT91C_BASE_ADC->ADC_MR =
1343 ADC_MODE_PRESCALE(32) |
1344 ADC_MODE_STARTUP_TIME(16) |
1345 ADC_MODE_SAMPLE_HOLD_TIME(8);
1346 AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1347 // start ADC
1348 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1349
1350 // Now run a 'software UART' on the stream of incoming samples.
1351 UartReset();
1352 Uart.output = received;
1353
1354 // Clear RXRDY:
1355 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1356
1357 for(;;) {
1358 WDT_HIT();
1359
1360 if (BUTTON_PRESS()) return 1;
1361
1362 // test if the field exists
1363 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1364 analogCnt++;
1365 analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1366 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1367 if (analogCnt >= 32) {
1368 if ((33000 * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1369 vtime = GetTickCount();
1370 if (!timer) timer = vtime;
1371 // 50ms no field --> card to idle state
1372 if (vtime - timer > 50) return 2;
1373 } else
1374 if (timer) timer = 0;
1375 analogCnt = 0;
1376 analogAVG = 0;
1377 }
1378 }
1379
1380 // receive and test the miller decoding
1381 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1382 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1383 if(MillerDecoding(b, 0)) {
1384 *len = Uart.len;
1385 return 0;
1386 }
1387 }
1388
1389 }
1390 }
1391
1392
1393 static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, bool correctionNeeded)
1394 {
1395 uint8_t b;
1396 uint16_t i = 0;
1397 uint32_t ThisTransferTime;
1398
1399 // Modulate Manchester
1400 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1401
1402 // include correction bit if necessary
1403 if (Uart.parityBits & 0x01) {
1404 correctionNeeded = TRUE;
1405 }
1406 if(correctionNeeded) {
1407 // 1236, so correction bit needed
1408 i = 0;
1409 } else {
1410 i = 1;
1411 }
1412
1413 // clear receiving shift register and holding register
1414 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1415 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1416 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1417 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1418
1419 // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1420 for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never
1421 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1422 if (AT91C_BASE_SSC->SSC_RHR) break;
1423 }
1424
1425 while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1426
1427 // Clear TXRDY:
1428 AT91C_BASE_SSC->SSC_THR = SEC_F;
1429
1430 // send cycle
1431 for(; i <= respLen; ) {
1432 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1433 AT91C_BASE_SSC->SSC_THR = resp[i++];
1434 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1435 }
1436
1437 if(BUTTON_PRESS()) {
1438 break;
1439 }
1440 }
1441
1442 // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1443 for (i = 0; i < 2 ; ) {
1444 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1445 AT91C_BASE_SSC->SSC_THR = SEC_F;
1446 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1447 i++;
1448 }
1449 }
1450
1451 LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
1452
1453 return 0;
1454 }
1455
1456 int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
1457 Code4bitAnswerAsTag(resp);
1458 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1459 // do the tracing for the previous reader request and this tag answer:
1460 EmLogTrace(Uart.output,
1461 Uart.len,
1462 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1463 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1464 Uart.parityBits,
1465 &resp,
1466 1,
1467 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1468 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1469 SwapBits(GetParity(&resp, 1), 1));
1470 return res;
1471 }
1472
1473 int EmSend4bit(uint8_t resp){
1474 return EmSend4bitEx(resp, false);
1475 }
1476
1477 int EmSendCmdExPar(uint8_t *resp, int respLen, bool correctionNeeded, uint32_t par){
1478 CodeIso14443aAsTagPar(resp, respLen, par);
1479 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1480 // do the tracing for the previous reader request and this tag answer:
1481 EmLogTrace(Uart.output,
1482 Uart.len,
1483 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1484 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1485 Uart.parityBits,
1486 resp,
1487 respLen,
1488 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1489 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1490 SwapBits(GetParity(resp, respLen), respLen));
1491 return res;
1492 }
1493
1494 int EmSendCmdEx(uint8_t *resp, int respLen, bool correctionNeeded){
1495 return EmSendCmdExPar(resp, respLen, correctionNeeded, GetParity(resp, respLen));
1496 }
1497
1498 int EmSendCmd(uint8_t *resp, int respLen){
1499 return EmSendCmdExPar(resp, respLen, false, GetParity(resp, respLen));
1500 }
1501
1502 int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par){
1503 return EmSendCmdExPar(resp, respLen, false, par);
1504 }
1505
1506 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint32_t reader_Parity,
1507 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint32_t tag_Parity)
1508 {
1509 if (tracing) {
1510 // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1511 // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1512 // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1513 uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1514 uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1515 uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1516 reader_EndTime = tag_StartTime - exact_fdt;
1517 reader_StartTime = reader_EndTime - reader_modlen;
1518 if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_Parity, TRUE)) {
1519 return FALSE;
1520 } else if (!LogTrace(NULL, 0, reader_EndTime, 0, TRUE)) {
1521 return FALSE;
1522 } else if (!LogTrace(tag_data, tag_len, tag_StartTime, tag_Parity, FALSE)) {
1523 return FALSE;
1524 } else {
1525 return (!LogTrace(NULL, 0, tag_EndTime, 0, FALSE));
1526 }
1527 } else {
1528 return TRUE;
1529 }
1530 }
1531
1532 //-----------------------------------------------------------------------------
1533 // Wait a certain time for tag response
1534 // If a response is captured return TRUE
1535 // If it takes too long return FALSE
1536 //-----------------------------------------------------------------------------
1537 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint16_t offset, int maxLen)
1538 {
1539 uint16_t c;
1540
1541 // Set FPGA mode to "reader listen mode", no modulation (listen
1542 // only, since we are receiving, not transmitting).
1543 // Signal field is on with the appropriate LED
1544 LED_D_ON();
1545 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1546
1547 // Now get the answer from the card
1548 DemodReset();
1549 Demod.output = receivedResponse;
1550
1551 // clear RXRDY:
1552 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1553
1554 c = 0;
1555 for(;;) {
1556 WDT_HIT();
1557
1558 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1559 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1560 if(ManchesterDecoding(b, offset, 0)) {
1561 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1562 return TRUE;
1563 } else if(c++ > iso14a_timeout) {
1564 return FALSE;
1565 }
1566 }
1567 }
1568 }
1569
1570 void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par, uint32_t *timing)
1571 {
1572
1573 CodeIso14443aBitsAsReaderPar(frame,bits,par);
1574
1575 // Send command to tag
1576 TransmitFor14443a(ToSend, ToSendMax, timing);
1577 if(trigger)
1578 LED_A_ON();
1579
1580 // Log reader command in trace buffer
1581 if (tracing) {
1582 LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
1583 LogTrace(NULL, 0, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, 0, TRUE);
1584 }
1585 }
1586
1587 void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par, uint32_t *timing)
1588 {
1589 ReaderTransmitBitsPar(frame,len*8,par, timing);
1590 }
1591
1592 void ReaderTransmitBits(uint8_t* frame, int len, uint32_t *timing)
1593 {
1594 // Generate parity and redirect
1595 ReaderTransmitBitsPar(frame,len,GetParity(frame,len/8), timing);
1596 }
1597
1598 void ReaderTransmit(uint8_t* frame, int len, uint32_t *timing)
1599 {
1600 // Generate parity and redirect
1601 ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len), timing);
1602 }
1603
1604 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset)
1605 {
1606 if (!GetIso14443aAnswerFromTag(receivedAnswer,offset,160)) return FALSE;
1607 if (tracing) {
1608 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.parityBits, FALSE);
1609 LogTrace(NULL, 0, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, 0, FALSE);
1610 }
1611 return Demod.len;
1612 }
1613
1614 int ReaderReceive(uint8_t* receivedAnswer)
1615 {
1616 return ReaderReceiveOffset(receivedAnswer, 0);
1617 }
1618
1619 int ReaderReceivePar(uint8_t *receivedAnswer, uint32_t *parptr)
1620 {
1621 if (!GetIso14443aAnswerFromTag(receivedAnswer,0,160)) return FALSE;
1622 if (tracing) {
1623 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.parityBits, FALSE);
1624 LogTrace(NULL, 0, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, 0, FALSE);
1625 }
1626 *parptr = Demod.parityBits;
1627 return Demod.len;
1628 }
1629
1630 /* performs iso14443a anticollision procedure
1631 * fills the uid pointer unless NULL
1632 * fills resp_data unless NULL */
1633 int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, uint32_t* cuid_ptr) {
1634 uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP
1635 uint8_t sel_all[] = { 0x93,0x20 };
1636 uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1637 uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1638 uint8_t* resp = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); // was 3560 - tied to other size changes
1639 byte_t uid_resp[4];
1640 size_t uid_resp_len;
1641
1642 uint8_t sak = 0x04; // cascade uid
1643 int cascade_level = 0;
1644 int len;
1645
1646 // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1647 ReaderTransmitBitsPar(wupa,7,0, NULL);
1648
1649 // Receive the ATQA
1650 if(!ReaderReceive(resp)) return 0;
1651 // Dbprintf("atqa: %02x %02x",resp[0],resp[1]);
1652
1653 if(p_hi14a_card) {
1654 memcpy(p_hi14a_card->atqa, resp, 2);
1655 p_hi14a_card->uidlen = 0;
1656 memset(p_hi14a_card->uid,0,10);
1657 }
1658
1659 // clear uid
1660 if (uid_ptr) {
1661 memset(uid_ptr,0,10);
1662 }
1663
1664 // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1665 // which case we need to make a cascade 2 request and select - this is a long UID
1666 // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1667 for(; sak & 0x04; cascade_level++) {
1668 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1669 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1670
1671 // SELECT_ALL
1672 ReaderTransmit(sel_all,sizeof(sel_all), NULL);
1673 if (!ReaderReceive(resp)) return 0;
1674
1675 if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit
1676 memset(uid_resp, 0, 4);
1677 uint16_t uid_resp_bits = 0;
1678 uint16_t collision_answer_offset = 0;
1679 // anti-collision-loop:
1680 while (Demod.collisionPos) {
1681 Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1682 for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point
1683 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1684 uid_resp[uid_resp_bits & 0xf8] |= UIDbit << (uid_resp_bits % 8);
1685 }
1686 uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position
1687 uid_resp_bits++;
1688 // construct anticollosion command:
1689 sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits
1690 for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1691 sel_uid[2+i] = uid_resp[i];
1692 }
1693 collision_answer_offset = uid_resp_bits%8;
1694 ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1695 if (!ReaderReceiveOffset(resp, collision_answer_offset)) return 0;
1696 }
1697 // finally, add the last bits and BCC of the UID
1698 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1699 uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1700 uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1701 }
1702
1703 } else { // no collision, use the response to SELECT_ALL as current uid
1704 memcpy(uid_resp,resp,4);
1705 }
1706 uid_resp_len = 4;
1707 // Dbprintf("uid: %02x %02x %02x %02x",uid_resp[0],uid_resp[1],uid_resp[2],uid_resp[3]);
1708
1709 // calculate crypto UID. Always use last 4 Bytes.
1710 if(cuid_ptr) {
1711 *cuid_ptr = bytes_to_num(uid_resp, 4);
1712 }
1713
1714 // Construct SELECT UID command
1715 sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1716 memcpy(sel_uid+2,uid_resp,4); // the UID
1717 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC
1718 AppendCrc14443a(sel_uid,7); // calculate and add CRC
1719 ReaderTransmit(sel_uid,sizeof(sel_uid), NULL);
1720
1721 // Receive the SAK
1722 if (!ReaderReceive(resp)) return 0;
1723 sak = resp[0];
1724
1725 // Test if more parts of the uid are comming
1726 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
1727 // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
1728 // http://www.nxp.com/documents/application_note/AN10927.pdf
1729 memcpy(uid_resp, uid_resp + 1, 3);
1730 uid_resp_len = 3;
1731 }
1732
1733 if(uid_ptr) {
1734 memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
1735 }
1736
1737 if(p_hi14a_card) {
1738 memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
1739 p_hi14a_card->uidlen += uid_resp_len;
1740 }
1741 }
1742
1743 if(p_hi14a_card) {
1744 p_hi14a_card->sak = sak;
1745 p_hi14a_card->ats_len = 0;
1746 }
1747
1748 if( (sak & 0x20) == 0) {
1749 return 2; // non iso14443a compliant tag
1750 }
1751
1752 // Request for answer to select
1753 AppendCrc14443a(rats, 2);
1754 ReaderTransmit(rats, sizeof(rats), NULL);
1755
1756 if (!(len = ReaderReceive(resp))) return 0;
1757
1758 if(p_hi14a_card) {
1759 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
1760 p_hi14a_card->ats_len = len;
1761 }
1762
1763 // reset the PCB block number
1764 iso14_pcb_blocknum = 0;
1765 return 1;
1766 }
1767
1768 void iso14443a_setup(uint8_t fpga_minor_mode) {
1769 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1770 // Set up the synchronous serial port
1771 FpgaSetupSsc();
1772 // connect Demodulated Signal to ADC:
1773 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1774
1775 // Signal field is on with the appropriate LED
1776 if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
1777 || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
1778 LED_D_ON();
1779 } else {
1780 LED_D_OFF();
1781 }
1782 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
1783
1784 // Start the timer
1785 StartCountSspClk();
1786
1787 DemodReset();
1788 UartReset();
1789 NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
1790 iso14a_set_timeout(1050); // 10ms default
1791 }
1792
1793 int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) {
1794 uint8_t real_cmd[cmd_len+4];
1795 real_cmd[0] = 0x0a; //I-Block
1796 // put block number into the PCB
1797 real_cmd[0] |= iso14_pcb_blocknum;
1798 real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
1799 memcpy(real_cmd+2, cmd, cmd_len);
1800 AppendCrc14443a(real_cmd,cmd_len+2);
1801
1802 ReaderTransmit(real_cmd, cmd_len+4, NULL);
1803 size_t len = ReaderReceive(data);
1804 uint8_t * data_bytes = (uint8_t *) data;
1805 if (!len)
1806 return 0; //DATA LINK ERROR
1807 // if we received an I- or R(ACK)-Block with a block number equal to the
1808 // current block number, toggle the current block number
1809 else if (len >= 4 // PCB+CID+CRC = 4 bytes
1810 && ((data_bytes[0] & 0xC0) == 0 // I-Block
1811 || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
1812 && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
1813 {
1814 iso14_pcb_blocknum ^= 1;
1815 }
1816
1817 return len;
1818 }
1819
1820 //-----------------------------------------------------------------------------
1821 // Read an ISO 14443a tag. Send out commands and store answers.
1822 //
1823 //-----------------------------------------------------------------------------
1824 void ReaderIso14443a(UsbCommand *c)
1825 {
1826 iso14a_command_t param = c->arg[0];
1827 uint8_t *cmd = c->d.asBytes;
1828 size_t len = c->arg[1];
1829 size_t lenbits = c->arg[2];
1830 uint32_t arg0 = 0;
1831 byte_t buf[USB_CMD_DATA_SIZE];
1832
1833 if(param & ISO14A_CONNECT) {
1834 iso14a_clear_trace();
1835 }
1836
1837 iso14a_set_tracing(TRUE);
1838
1839 if(param & ISO14A_REQUEST_TRIGGER) {
1840 iso14a_set_trigger(TRUE);
1841 }
1842
1843 if(param & ISO14A_CONNECT) {
1844 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
1845 if(!(param & ISO14A_NO_SELECT)) {
1846 iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
1847 arg0 = iso14443a_select_card(NULL,card,NULL);
1848 cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
1849 }
1850 }
1851
1852 if(param & ISO14A_SET_TIMEOUT) {
1853 iso14a_timeout = c->arg[2];
1854 }
1855
1856 if(param & ISO14A_APDU) {
1857 arg0 = iso14_apdu(cmd, len, buf);
1858 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
1859 }
1860
1861 if(param & ISO14A_RAW) {
1862 if(param & ISO14A_APPEND_CRC) {
1863 AppendCrc14443a(cmd,len);
1864 len += 2;
1865 if (lenbits) lenbits += 16;
1866 }
1867 if(lenbits>0) {
1868 ReaderTransmitBitsPar(cmd,lenbits,GetParity(cmd,lenbits/8), NULL);
1869 } else {
1870 ReaderTransmit(cmd,len, NULL);
1871 }
1872 arg0 = ReaderReceive(buf);
1873 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
1874 }
1875
1876 if(param & ISO14A_REQUEST_TRIGGER) {
1877 iso14a_set_trigger(FALSE);
1878 }
1879
1880 if(param & ISO14A_NO_DISCONNECT) {
1881 return;
1882 }
1883
1884 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1885 LEDsoff();
1886 }
1887
1888
1889 // Determine the distance between two nonces.
1890 // Assume that the difference is small, but we don't know which is first.
1891 // Therefore try in alternating directions.
1892 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
1893
1894 uint16_t i;
1895 uint32_t nttmp1, nttmp2;
1896
1897 if (nt1 == nt2) return 0;
1898
1899 nttmp1 = nt1;
1900 nttmp2 = nt2;
1901
1902 for (i = 1; i < 32768; i++) {
1903 nttmp1 = prng_successor(nttmp1, 1);
1904 if (nttmp1 == nt2) return i;
1905 nttmp2 = prng_successor(nttmp2, 1);
1906 if (nttmp2 == nt1) return -i;
1907 }
1908
1909 return(-99999); // either nt1 or nt2 are invalid nonces
1910 }
1911
1912
1913 //-----------------------------------------------------------------------------
1914 // Recover several bits of the cypher stream. This implements (first stages of)
1915 // the algorithm described in "The Dark Side of Security by Obscurity and
1916 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
1917 // (article by Nicolas T. Courtois, 2009)
1918 //-----------------------------------------------------------------------------
1919 void ReaderMifare(bool first_try)
1920 {
1921 // Mifare AUTH
1922 uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b };
1923 uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
1924 static uint8_t mf_nr_ar3;
1925
1926 uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
1927
1928 iso14a_clear_trace();
1929 iso14a_set_tracing(TRUE);
1930
1931 byte_t nt_diff = 0;
1932 byte_t par = 0;
1933 //byte_t par_mask = 0xff;
1934 static byte_t par_low = 0;
1935 bool led_on = TRUE;
1936 uint8_t uid[10];
1937 uint32_t cuid;
1938
1939 uint32_t nt, previous_nt;
1940 static uint32_t nt_attacked = 0;
1941 byte_t par_list[8] = {0,0,0,0,0,0,0,0};
1942 byte_t ks_list[8] = {0,0,0,0,0,0,0,0};
1943
1944 static uint32_t sync_time;
1945 static uint32_t sync_cycles;
1946 int catch_up_cycles = 0;
1947 int last_catch_up = 0;
1948 uint16_t consecutive_resyncs = 0;
1949 int isOK = 0;
1950
1951
1952
1953 if (first_try) {
1954 mf_nr_ar3 = 0;
1955 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
1956 sync_time = GetCountSspClk() & 0xfffffff8;
1957 sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
1958 nt_attacked = 0;
1959 nt = 0;
1960 par = 0;
1961 }
1962 else {
1963 // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
1964 // nt_attacked = prng_successor(nt_attacked, 1);
1965 mf_nr_ar3++;
1966 mf_nr_ar[3] = mf_nr_ar3;
1967 par = par_low;
1968 }
1969
1970 LED_A_ON();
1971 LED_B_OFF();
1972 LED_C_OFF();
1973
1974
1975 for(uint16_t i = 0; TRUE; i++) {
1976
1977 WDT_HIT();
1978
1979 // Test if the action was cancelled
1980 if(BUTTON_PRESS()) {
1981 break;
1982 }
1983
1984 LED_C_ON();
1985
1986 if(!iso14443a_select_card(uid, NULL, &cuid)) {
1987 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
1988 continue;
1989 }
1990
1991 sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
1992 catch_up_cycles = 0;
1993
1994 // if we missed the sync time already, advance to the next nonce repeat
1995 while(GetCountSspClk() > sync_time) {
1996 sync_time = (sync_time & 0xfffffff8) + sync_cycles;
1997 }
1998
1999 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2000 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2001
2002 // Receive the (4 Byte) "random" nonce
2003 if (!ReaderReceive(receivedAnswer)) {
2004 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce");
2005 continue;
2006 }
2007
2008 previous_nt = nt;
2009 nt = bytes_to_num(receivedAnswer, 4);
2010
2011 // Transmit reader nonce with fake par
2012 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2013
2014 if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
2015 int nt_distance = dist_nt(previous_nt, nt);
2016 if (nt_distance == 0) {
2017 nt_attacked = nt;
2018 }
2019 else {
2020 if (nt_distance == -99999) { // invalid nonce received, try again
2021 continue;
2022 }
2023 sync_cycles = (sync_cycles - nt_distance);
2024 if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
2025 continue;
2026 }
2027 }
2028
2029 if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
2030 catch_up_cycles = -dist_nt(nt_attacked, nt);
2031 if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one.
2032 catch_up_cycles = 0;
2033 continue;
2034 }
2035 if (catch_up_cycles == last_catch_up) {
2036 consecutive_resyncs++;
2037 }
2038 else {
2039 last_catch_up = catch_up_cycles;
2040 consecutive_resyncs = 0;
2041 }
2042 if (consecutive_resyncs < 3) {
2043 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);
2044 }
2045 else {
2046 sync_cycles = sync_cycles + catch_up_cycles;
2047 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);
2048 }
2049 continue;
2050 }
2051
2052 consecutive_resyncs = 0;
2053
2054 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2055 if (ReaderReceive(receivedAnswer))
2056 {
2057 catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2058
2059 if (nt_diff == 0)
2060 {
2061 par_low = par & 0x07; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change
2062 }
2063
2064 led_on = !led_on;
2065 if(led_on) LED_B_ON(); else LED_B_OFF();
2066
2067 par_list[nt_diff] = par;
2068 ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
2069
2070 // Test if the information is complete
2071 if (nt_diff == 0x07) {
2072 isOK = 1;
2073 break;
2074 }
2075
2076 nt_diff = (nt_diff + 1) & 0x07;
2077 mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2078 par = par_low;
2079 } else {
2080 if (nt_diff == 0 && first_try)
2081 {
2082 par++;
2083 } else {
2084 par = (((par >> 3) + 1) << 3) | par_low;
2085 }
2086 }
2087 }
2088
2089
2090 mf_nr_ar[3] &= 0x1F;
2091
2092 byte_t buf[28];
2093 memcpy(buf + 0, uid, 4);
2094 num_to_bytes(nt, 4, buf + 4);
2095 memcpy(buf + 8, par_list, 8);
2096 memcpy(buf + 16, ks_list, 8);
2097 memcpy(buf + 24, mf_nr_ar, 4);
2098
2099 cmd_send(CMD_ACK,isOK,0,0,buf,28);
2100
2101 // Thats it...
2102 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2103 LEDsoff();
2104
2105 iso14a_set_tracing(FALSE);
2106 }
2107
2108 /**
2109 *MIFARE 1K simulate.
2110 *
2111 *@param flags :
2112 * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2113 * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
2114 * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
2115 * FLAG_NR_AR_ATTACK - means we should collect NR_AR responses for bruteforcing later
2116 *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2117 */
2118 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
2119 {
2120 int cardSTATE = MFEMUL_NOFIELD;
2121 int _7BUID = 0;
2122 int vHf = 0; // in mV
2123 int res;
2124 uint32_t selTimer = 0;
2125 uint32_t authTimer = 0;
2126 uint32_t par = 0;
2127 int len = 0;
2128 uint8_t cardWRBL = 0;
2129 uint8_t cardAUTHSC = 0;
2130 uint8_t cardAUTHKEY = 0xff; // no authentication
2131 uint32_t cardRr = 0;
2132 uint32_t cuid = 0;
2133 //uint32_t rn_enc = 0;
2134 uint32_t ans = 0;
2135 uint32_t cardINTREG = 0;
2136 uint8_t cardINTBLOCK = 0;
2137 struct Crypto1State mpcs = {0, 0};
2138 struct Crypto1State *pcs;
2139 pcs = &mpcs;
2140 uint32_t numReads = 0;//Counts numer of times reader read a block
2141 uint8_t* receivedCmd = eml_get_bigbufptr_recbuf();
2142 uint8_t *response = eml_get_bigbufptr_sendbuf();
2143
2144 uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
2145 uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2146 uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
2147 uint8_t rSAK[] = {0x08, 0xb6, 0xdd};
2148 uint8_t rSAK1[] = {0x04, 0xda, 0x17};
2149
2150 uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04};
2151 uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2152
2153 //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
2154 // This can be used in a reader-only attack.
2155 // (it can also be retrieved via 'hf 14a list', but hey...
2156 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
2157 uint8_t ar_nr_collected = 0;
2158
2159 // clear trace
2160 iso14a_clear_trace();
2161 iso14a_set_tracing(TRUE);
2162
2163 // Authenticate response - nonce
2164 uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2165
2166 //-- Determine the UID
2167 // Can be set from emulator memory, incoming data
2168 // and can be 7 or 4 bytes long
2169 if (flags & FLAG_4B_UID_IN_DATA)
2170 {
2171 // 4B uid comes from data-portion of packet
2172 memcpy(rUIDBCC1,datain,4);
2173 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2174
2175 } else if (flags & FLAG_7B_UID_IN_DATA) {
2176 // 7B uid comes from data-portion of packet
2177 memcpy(&rUIDBCC1[1],datain,3);
2178 memcpy(rUIDBCC2, datain+3, 4);
2179 _7BUID = true;
2180 } else {
2181 // get UID from emul memory
2182 emlGetMemBt(receivedCmd, 7, 1);
2183 _7BUID = !(receivedCmd[0] == 0x00);
2184 if (!_7BUID) { // ---------- 4BUID
2185 emlGetMemBt(rUIDBCC1, 0, 4);
2186 } else { // ---------- 7BUID
2187 emlGetMemBt(&rUIDBCC1[1], 0, 3);
2188 emlGetMemBt(rUIDBCC2, 3, 4);
2189 }
2190 }
2191
2192 /*
2193 * Regardless of what method was used to set the UID, set fifth byte and modify
2194 * the ATQA for 4 or 7-byte UID
2195 */
2196 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2197 if (_7BUID) {
2198 rATQA[0] = 0x44;
2199 rUIDBCC1[0] = 0x88;
2200 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2201 }
2202
2203 // We need to listen to the high-frequency, peak-detected path.
2204 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2205
2206
2207 if (MF_DBGLEVEL >= 1) {
2208 if (!_7BUID) {
2209 Dbprintf("4B UID: %02x%02x%02x%02x",
2210 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3]);
2211 } else {
2212 Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",
2213 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3],
2214 rUIDBCC2[0], rUIDBCC2[1] ,rUIDBCC2[2], rUIDBCC2[3]);
2215 }
2216 }
2217
2218 bool finished = FALSE;
2219 while (!BUTTON_PRESS() && !finished) {
2220 WDT_HIT();
2221
2222 // find reader field
2223 // Vref = 3300mV, and an 10:1 voltage divider on the input
2224 // can measure voltages up to 33000 mV
2225 if (cardSTATE == MFEMUL_NOFIELD) {
2226 vHf = (33000 * AvgAdc(ADC_CHAN_HF)) >> 10;
2227 if (vHf > MF_MINFIELDV) {
2228 cardSTATE_TO_IDLE();
2229 LED_A_ON();
2230 }
2231 }
2232 if(cardSTATE == MFEMUL_NOFIELD) continue;
2233
2234 //Now, get data
2235
2236 res = EmGetCmd(receivedCmd, &len);
2237 if (res == 2) { //Field is off!
2238 cardSTATE = MFEMUL_NOFIELD;
2239 LEDsoff();
2240 continue;
2241 } else if (res == 1) {
2242 break; //return value 1 means button press
2243 }
2244
2245 // REQ or WUP request in ANY state and WUP in HALTED state
2246 if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
2247 selTimer = GetTickCount();
2248 EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
2249 cardSTATE = MFEMUL_SELECT1;
2250
2251 // init crypto block
2252 LED_B_OFF();
2253 LED_C_OFF();
2254 crypto1_destroy(pcs);
2255 cardAUTHKEY = 0xff;
2256 continue;
2257 }
2258
2259 switch (cardSTATE) {
2260 case MFEMUL_NOFIELD:
2261 case MFEMUL_HALTED:
2262 case MFEMUL_IDLE:{
2263 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2264 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2265 break;
2266 }
2267 case MFEMUL_SELECT1:{
2268 // select all
2269 if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
2270 if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received");
2271 EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2272 break;
2273 }
2274
2275 if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
2276 {
2277 Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
2278 }
2279 // select card
2280 if (len == 9 &&
2281 (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2282 EmSendCmd(_7BUID?rSAK1:rSAK, sizeof(_7BUID?rSAK1:rSAK));
2283 cuid = bytes_to_num(rUIDBCC1, 4);
2284 if (!_7BUID) {
2285 cardSTATE = MFEMUL_WORK;
2286 LED_B_ON();
2287 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2288 break;
2289 } else {
2290 cardSTATE = MFEMUL_SELECT2;
2291 }
2292 }
2293 break;
2294 }
2295 case MFEMUL_AUTH1:{
2296 if( len != 8)
2297 {
2298 cardSTATE_TO_IDLE();
2299 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2300 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2301 break;
2302 }
2303 uint32_t ar = bytes_to_num(receivedCmd, 4);
2304 uint32_t nr= bytes_to_num(&receivedCmd[4], 4);
2305
2306 //Collect AR/NR
2307 if(ar_nr_collected < 2){
2308 if(ar_nr_responses[2] != ar)
2309 {// Avoid duplicates... probably not necessary, ar should vary.
2310 ar_nr_responses[ar_nr_collected*4] = cuid;
2311 ar_nr_responses[ar_nr_collected*4+1] = nonce;
2312 ar_nr_responses[ar_nr_collected*4+2] = ar;
2313 ar_nr_responses[ar_nr_collected*4+3] = nr;
2314 ar_nr_collected++;
2315 }
2316 }
2317
2318 // --- crypto
2319 crypto1_word(pcs, ar , 1);
2320 cardRr = nr ^ crypto1_word(pcs, 0, 0);
2321
2322 // test if auth OK
2323 if (cardRr != prng_successor(nonce, 64)){
2324 if (MF_DBGLEVEL >= 2) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
2325 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2326 cardRr, prng_successor(nonce, 64));
2327 // Shouldn't we respond anything here?
2328 // Right now, we don't nack or anything, which causes the
2329 // reader to do a WUPA after a while. /Martin
2330 // -- which is the correct response. /piwi
2331 cardSTATE_TO_IDLE();
2332 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2333 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2334 break;
2335 }
2336
2337 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2338
2339 num_to_bytes(ans, 4, rAUTH_AT);
2340 // --- crypto
2341 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2342 LED_C_ON();
2343 cardSTATE = MFEMUL_WORK;
2344 if (MF_DBGLEVEL >= 4) Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2345 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2346 GetTickCount() - authTimer);
2347 break;
2348 }
2349 case MFEMUL_SELECT2:{
2350 if (!len) {
2351 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2352 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2353 break;
2354 }
2355 if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
2356 EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2357 break;
2358 }
2359
2360 // select 2 card
2361 if (len == 9 &&
2362 (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
2363 EmSendCmd(rSAK, sizeof(rSAK));
2364 cuid = bytes_to_num(rUIDBCC2, 4);
2365 cardSTATE = MFEMUL_WORK;
2366 LED_B_ON();
2367 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2368 break;
2369 }
2370
2371 // i guess there is a command). go into the work state.
2372 if (len != 4) {
2373 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2374 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2375 break;
2376 }
2377 cardSTATE = MFEMUL_WORK;
2378 //goto lbWORK;
2379 //intentional fall-through to the next case-stmt
2380 }
2381
2382 case MFEMUL_WORK:{
2383 if (len == 0) {
2384 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2385 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2386 break;
2387 }
2388
2389 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2390
2391 if(encrypted_data) {
2392 // decrypt seqence
2393 mf_crypto1_decrypt(pcs, receivedCmd, len);
2394 }
2395
2396 if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
2397 authTimer = GetTickCount();
2398 cardAUTHSC = receivedCmd[1] / 4; // received block num
2399 cardAUTHKEY = receivedCmd[0] - 0x60;
2400 crypto1_destroy(pcs);//Added by martin
2401 crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2402
2403 if (!encrypted_data) { // first authentication
2404 if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2405
2406 crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
2407 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2408 } else { // nested authentication
2409 if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2410 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2411 num_to_bytes(ans, 4, rAUTH_AT);
2412 }
2413 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2414 //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
2415 cardSTATE = MFEMUL_AUTH1;
2416 break;
2417 }
2418
2419 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2420 // BUT... ACK --> NACK
2421 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2422 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2423 break;
2424 }
2425
2426 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2427 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2428 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2429 break;
2430 }
2431
2432 if(len != 4) {
2433 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2434 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2435 break;
2436 }
2437
2438 if(receivedCmd[0] == 0x30 // read block
2439 || receivedCmd[0] == 0xA0 // write block
2440 || receivedCmd[0] == 0xC0 // inc
2441 || receivedCmd[0] == 0xC1 // dec
2442 || receivedCmd[0] == 0xC2 // restore
2443 || receivedCmd[0] == 0xB0) { // transfer
2444 if (receivedCmd[1] >= 16 * 4) {
2445 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2446 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]);
2447 break;
2448 }
2449
2450 if (receivedCmd[1] / 4 != cardAUTHSC) {
2451 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2452 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);
2453 break;
2454 }
2455 }
2456 // read block
2457 if (receivedCmd[0] == 0x30) {
2458 if (MF_DBGLEVEL >= 4) {
2459 Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
2460 }
2461 emlGetMem(response, receivedCmd[1], 1);
2462 AppendCrc14443a(response, 16);
2463 mf_crypto1_encrypt(pcs, response, 18, &par);
2464 EmSendCmdPar(response, 18, par);
2465 numReads++;
2466 if(exitAfterNReads > 0 && numReads == exitAfterNReads) {
2467 Dbprintf("%d reads done, exiting", numReads);
2468 finished = true;
2469 }
2470 break;
2471 }
2472 // write block
2473 if (receivedCmd[0] == 0xA0) {
2474 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
2475 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2476 cardSTATE = MFEMUL_WRITEBL2;
2477 cardWRBL = receivedCmd[1];
2478 break;
2479 }
2480 // increment, decrement, restore
2481 if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
2482 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2483 if (emlCheckValBl(receivedCmd[1])) {
2484 if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2485 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2486 break;
2487 }
2488 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2489 if (receivedCmd[0] == 0xC1)
2490 cardSTATE = MFEMUL_INTREG_INC;
2491 if (receivedCmd[0] == 0xC0)
2492 cardSTATE = MFEMUL_INTREG_DEC;
2493 if (receivedCmd[0] == 0xC2)
2494 cardSTATE = MFEMUL_INTREG_REST;
2495 cardWRBL = receivedCmd[1];
2496 break;
2497 }
2498 // transfer
2499 if (receivedCmd[0] == 0xB0) {
2500 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2501 if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2502 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2503 else
2504 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2505 break;
2506 }
2507 // halt
2508 if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
2509 LED_B_OFF();
2510 LED_C_OFF();
2511 cardSTATE = MFEMUL_HALTED;
2512 if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer);
2513 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2514 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2515 break;
2516 }
2517 // RATS
2518 if (receivedCmd[0] == 0xe0) {//RATS
2519 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2520 break;
2521 }
2522 // command not allowed
2523 if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking");
2524 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2525 break;
2526 }
2527 case MFEMUL_WRITEBL2:{
2528 if (len == 18){
2529 mf_crypto1_decrypt(pcs, receivedCmd, len);
2530 emlSetMem(receivedCmd, cardWRBL, 1);
2531 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2532 cardSTATE = MFEMUL_WORK;
2533 } else {
2534 cardSTATE_TO_IDLE();
2535 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2536 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2537 }
2538 break;
2539 }
2540
2541 case MFEMUL_INTREG_INC:{
2542 mf_crypto1_decrypt(pcs, receivedCmd, len);
2543 memcpy(&ans, receivedCmd, 4);
2544 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2545 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2546 cardSTATE_TO_IDLE();
2547 break;
2548 }
2549 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2550 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2551 cardINTREG = cardINTREG + ans;
2552 cardSTATE = MFEMUL_WORK;
2553 break;
2554 }
2555 case MFEMUL_INTREG_DEC:{
2556 mf_crypto1_decrypt(pcs, receivedCmd, len);
2557 memcpy(&ans, receivedCmd, 4);
2558 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2559 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2560 cardSTATE_TO_IDLE();
2561 break;
2562 }
2563 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2564 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2565 cardINTREG = cardINTREG - ans;
2566 cardSTATE = MFEMUL_WORK;
2567 break;
2568 }
2569 case MFEMUL_INTREG_REST:{
2570 mf_crypto1_decrypt(pcs, receivedCmd, len);
2571 memcpy(&ans, receivedCmd, 4);
2572 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2573 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2574 cardSTATE_TO_IDLE();
2575 break;
2576 }
2577 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2578 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2579 cardSTATE = MFEMUL_WORK;
2580 break;
2581 }
2582 }
2583 }
2584
2585 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2586 LEDsoff();
2587
2588 if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
2589 {
2590 //May just aswell send the collected ar_nr in the response aswell
2591 cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_responses,ar_nr_collected*4*4);
2592 }
2593
2594 if(flags & FLAG_NR_AR_ATTACK)
2595 {
2596 if(ar_nr_collected > 1) {
2597 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
2598 Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
2599 ar_nr_responses[0], // UID
2600 ar_nr_responses[1], //NT
2601 ar_nr_responses[2], //AR1
2602 ar_nr_responses[3], //NR1
2603 ar_nr_responses[6], //AR2
2604 ar_nr_responses[7] //NR2
2605 );
2606 } else {
2607 Dbprintf("Failed to obtain two AR/NR pairs!");
2608 if(ar_nr_collected >0) {
2609 Dbprintf("Only got these: UID=%08x, nonce=%08x, AR1=%08x, NR1=%08x",
2610 ar_nr_responses[0], // UID
2611 ar_nr_responses[1], //NT
2612 ar_nr_responses[2], //AR1
2613 ar_nr_responses[3] //NR1
2614 );
2615 }
2616 }
2617 }
2618 if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, traceLen);
2619 }
2620
2621
2622
2623 //-----------------------------------------------------------------------------
2624 // MIFARE sniffer.
2625 //
2626 //-----------------------------------------------------------------------------
2627 void RAMFUNC SniffMifare(uint8_t param) {
2628 // param:
2629 // bit 0 - trigger from first card answer
2630 // bit 1 - trigger from first reader 7-bit request
2631
2632 // C(red) A(yellow) B(green)
2633 LEDsoff();
2634 // init trace buffer
2635 iso14a_clear_trace();
2636 iso14a_set_tracing(TRUE);
2637
2638 // The command (reader -> tag) that we're receiving.
2639 // The length of a received command will in most cases be no more than 18 bytes.
2640 // So 32 should be enough!
2641 uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
2642 // The response (tag -> reader) that we're receiving.
2643 uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
2644
2645 // As we receive stuff, we copy it from receivedCmd or receivedResponse
2646 // into trace, along with its length and other annotations.
2647 //uint8_t *trace = (uint8_t *)BigBuf;
2648
2649 // The DMA buffer, used to stream samples from the FPGA
2650 uint8_t *dmaBuf = ((uint8_t *)BigBuf) + DMA_BUFFER_OFFSET;
2651 uint8_t *data = dmaBuf;
2652 uint8_t previous_data = 0;
2653 int maxDataLen = 0;
2654 int dataLen = 0;
2655 bool ReaderIsActive = FALSE;
2656 bool TagIsActive = FALSE;
2657
2658 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
2659
2660 // Set up the demodulator for tag -> reader responses.
2661 Demod.output = receivedResponse;
2662
2663 // Set up the demodulator for the reader -> tag commands
2664 Uart.output = receivedCmd;
2665
2666 // Setup for the DMA.
2667 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2668
2669 LED_D_OFF();
2670
2671 // init sniffer
2672 MfSniffInit();
2673
2674 // And now we loop, receiving samples.
2675 for(uint32_t sniffCounter = 0; TRUE; ) {
2676
2677 if(BUTTON_PRESS()) {
2678 DbpString("cancelled by button");
2679 break;
2680 }
2681
2682 LED_A_ON();
2683 WDT_HIT();
2684
2685 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
2686 // check if a transaction is completed (timeout after 2000ms).
2687 // if yes, stop the DMA transfer and send what we have so far to the client
2688 if (MfSniffSend(2000)) {
2689 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
2690 sniffCounter = 0;
2691 data = dmaBuf;
2692 maxDataLen = 0;
2693 ReaderIsActive = FALSE;
2694 TagIsActive = FALSE;
2695 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2696 }
2697 }
2698
2699 int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
2700 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
2701 if (readBufDataP <= dmaBufDataP){ // we are processing the same block of data which is currently being transferred
2702 dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
2703 } else {
2704 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
2705 }
2706 // test for length of buffer
2707 if(dataLen > maxDataLen) { // we are more behind than ever...
2708 maxDataLen = dataLen;
2709 if(dataLen > 400) {
2710 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
2711 break;
2712 }
2713 }
2714 if(dataLen < 1) continue;
2715
2716 // primary buffer was stopped ( <-- we lost data!
2717 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
2718 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
2719 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
2720 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
2721 }
2722 // secondary buffer sets as primary, secondary buffer was stopped
2723 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
2724 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
2725 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
2726 }
2727
2728 LED_A_OFF();
2729
2730 if (sniffCounter & 0x01) {
2731
2732 if(!TagIsActive) { // no need to try decoding tag data if the reader is sending
2733 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
2734 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
2735 LED_C_INV();
2736 if (MfSniffLogic(receivedCmd, Uart.len, Uart.parityBits, Uart.bitCount, TRUE)) break;
2737
2738 /* And ready to receive another command. */
2739 UartReset();
2740
2741 /* And also reset the demod code */
2742 DemodReset();
2743 }
2744 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
2745 }
2746
2747 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending
2748 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
2749 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
2750 LED_C_INV();
2751
2752 if (MfSniffLogic(receivedResponse, Demod.len, Demod.parityBits, Demod.bitCount, FALSE)) break;
2753
2754 // And ready to receive another response.
2755 DemodReset();
2756 }
2757 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
2758 }
2759 }
2760
2761 previous_data = *data;
2762 sniffCounter++;
2763 data++;
2764 if(data == dmaBuf + DMA_BUFFER_SIZE) {
2765 data = dmaBuf;
2766 }
2767
2768 } // main cycle
2769
2770 DbpString("COMMAND FINISHED");
2771
2772 FpgaDisableSscDma();
2773 MfSniffEnd();
2774
2775 Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
2776 LEDsoff();
2777 }
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