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[proxmark3-svn] / armsrc / iso14443a.c
1 //-----------------------------------------------------------------------------
2 // Merlok - June 2011, 2012
3 // Gerhard de Koning Gans - May 2008
4 // Hagen Fritsch - June 2010
5 //
6 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
7 // at your option, any later version. See the LICENSE.txt file for the text of
8 // the license.
9 //-----------------------------------------------------------------------------
10 // Routines to support ISO 14443 type A.
11 //-----------------------------------------------------------------------------
12
13 #include "proxmark3.h"
14 #include "apps.h"
15 #include "util.h"
16 #include "string.h"
17 #include "cmd.h"
18
19 #include "iso14443crc.h"
20 #include "iso14443a.h"
21 #include "crapto1.h"
22 #include "mifareutil.h"
23
24 static uint32_t iso14a_timeout;
25 uint8_t *trace = (uint8_t *) BigBuf+TRACE_OFFSET;
26 int rsamples = 0;
27 int traceLen = 0;
28 int tracing = TRUE;
29 uint8_t trigger = 0;
30 // the block number for the ISO14443-4 PCB
31 static uint8_t iso14_pcb_blocknum = 0;
32
33 //
34 // ISO14443 timing:
35 //
36 // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
37 #define REQUEST_GUARD_TIME (7000/16 + 1)
38 // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
39 #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
40 // bool LastCommandWasRequest = FALSE;
41
42 //
43 // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
44 //
45 // When the PM acts as reader and is receiving tag data, it takes
46 // 3 ticks delay in the AD converter
47 // 16 ticks until the modulation detector completes and sets curbit
48 // 8 ticks until bit_to_arm is assigned from curbit
49 // 8*16 ticks for the transfer from FPGA to ARM
50 // 4*16 ticks until we measure the time
51 // - 8*16 ticks because we measure the time of the previous transfer
52 #define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
53
54 // When the PM acts as a reader and is sending, it takes
55 // 4*16 ticks until we can write data to the sending hold register
56 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
57 // 8 ticks until the first transfer starts
58 // 8 ticks later the FPGA samples the data
59 // 1 tick to assign mod_sig_coil
60 #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
61
62 // When the PM acts as tag and is receiving it takes
63 // 2 ticks delay in the RF part (for the first falling edge),
64 // 3 ticks for the A/D conversion,
65 // 8 ticks on average until the start of the SSC transfer,
66 // 8 ticks until the SSC samples the first data
67 // 7*16 ticks to complete the transfer from FPGA to ARM
68 // 8 ticks until the next ssp_clk rising edge
69 // 4*16 ticks until we measure the time
70 // - 8*16 ticks because we measure the time of the previous transfer
71 #define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
72
73 // The FPGA will report its internal sending delay in
74 uint16_t FpgaSendQueueDelay;
75 // the 5 first bits are the number of bits buffered in mod_sig_buf
76 // the last three bits are the remaining ticks/2 after the mod_sig_buf shift
77 #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
78
79 // When the PM acts as tag and is sending, it takes
80 // 4*16 ticks until we can write data to the sending hold register
81 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
82 // 8 ticks until the first transfer starts
83 // 8 ticks later the FPGA samples the data
84 // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
85 // + 1 tick to assign mod_sig_coil
86 #define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
87
88 // When the PM acts as sniffer and is receiving tag data, it takes
89 // 3 ticks A/D conversion
90 // 14 ticks to complete the modulation detection
91 // 8 ticks (on average) until the result is stored in to_arm
92 // + the delays in transferring data - which is the same for
93 // sniffing reader and tag data and therefore not relevant
94 #define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
95
96 // When the PM acts as sniffer and is receiving reader data, it takes
97 // 2 ticks delay in analogue RF receiver (for the falling edge of the
98 // start bit, which marks the start of the communication)
99 // 3 ticks A/D conversion
100 // 8 ticks on average until the data is stored in to_arm.
101 // + the delays in transferring data - which is the same for
102 // sniffing reader and tag data and therefore not relevant
103 #define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
104
105 //variables used for timing purposes:
106 //these are in ssp_clk cycles:
107 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 bReader)
194 {
195 // Return when trace is full
196 if (traceLen + sizeof(timestamp) + sizeof(dwParity) + iLen >= TRACE_SIZE) {
197 tracing = FALSE; // don't trace any more
198 return FALSE;
199 }
200
201 // Trace the random, i'm curious
202 trace[traceLen++] = ((timestamp >> 0) & 0xff);
203 trace[traceLen++] = ((timestamp >> 8) & 0xff);
204 trace[traceLen++] = ((timestamp >> 16) & 0xff);
205 trace[traceLen++] = ((timestamp >> 24) & 0xff);
206 if (!bReader) {
207 trace[traceLen - 1] |= 0x80;
208 }
209 trace[traceLen++] = ((dwParity >> 0) & 0xff);
210 trace[traceLen++] = ((dwParity >> 8) & 0xff);
211 trace[traceLen++] = ((dwParity >> 16) & 0xff);
212 trace[traceLen++] = ((dwParity >> 24) & 0xff);
213 trace[traceLen++] = iLen;
214 if (btBytes != NULL && iLen != 0) {
215 memcpy(trace + traceLen, btBytes, iLen);
216 }
217 traceLen += iLen;
218 return TRUE;
219 }
220
221 //=============================================================================
222 // ISO 14443 Type A - Miller decoder
223 //=============================================================================
224 // Basics:
225 // This decoder is used when the PM3 acts as a tag.
226 // The reader will generate "pauses" by temporarily switching of the field.
227 // At the PM3 antenna we will therefore measure a modulated antenna voltage.
228 // The FPGA does a comparison with a threshold and would deliver e.g.:
229 // ........ 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 .......
230 // The Miller decoder needs to identify the following sequences:
231 // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0")
232 // 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information")
233 // 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1")
234 // Note 1: the bitstream may start at any time. We therefore need to sync.
235 // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
236 //-----------------------------------------------------------------------------
237 static tUart Uart;
238
239 // Lookup-Table to decide if 4 raw bits are a modulation.
240 // We accept two or three consecutive "0" in any position with the rest "1"
241 const bool Mod_Miller_LUT[] = {
242 TRUE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, FALSE,
243 TRUE, TRUE, FALSE, FALSE, TRUE, FALSE, FALSE, FALSE
244 };
245 #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x00F0) >> 4])
246 #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x000F)])
247
248 void UartReset()
249 {
250 Uart.state = STATE_UNSYNCD;
251 Uart.bitCount = 0;
252 Uart.len = 0; // number of decoded data bytes
253 Uart.shiftReg = 0; // shiftreg to hold decoded data bits
254 Uart.parityBits = 0; //
255 Uart.twoBits = 0x0000; // buffer for 2 Bits
256 Uart.highCnt = 0;
257 Uart.startTime = 0;
258 Uart.endTime = 0;
259 }
260
261
262 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
263 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
264 {
265
266 Uart.twoBits = (Uart.twoBits << 8) | bit;
267
268 if (Uart.state == STATE_UNSYNCD) { // not yet synced
269 if (Uart.highCnt < 7) { // wait for a stable unmodulated signal
270 if (Uart.twoBits == 0xffff) {
271 Uart.highCnt++;
272 } else {
273 Uart.highCnt = 0;
274 }
275 } else {
276 Uart.syncBit = 0xFFFF; // not set
277 // look for 00xx1111 (the start bit)
278 if ((Uart.twoBits & 0x6780) == 0x0780) Uart.syncBit = 7;
279 else if ((Uart.twoBits & 0x33C0) == 0x03C0) Uart.syncBit = 6;
280 else if ((Uart.twoBits & 0x19E0) == 0x01E0) Uart.syncBit = 5;
281 else if ((Uart.twoBits & 0x0CF0) == 0x00F0) Uart.syncBit = 4;
282 else if ((Uart.twoBits & 0x0678) == 0x0078) Uart.syncBit = 3;
283 else if ((Uart.twoBits & 0x033C) == 0x003C) Uart.syncBit = 2;
284 else if ((Uart.twoBits & 0x019E) == 0x001E) Uart.syncBit = 1;
285 else if ((Uart.twoBits & 0x00CF) == 0x000F) Uart.syncBit = 0;
286 if (Uart.syncBit != 0xFFFF) {
287 Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
288 Uart.startTime -= Uart.syncBit;
289 Uart.endTime = Uart.startTime;
290 Uart.state = STATE_START_OF_COMMUNICATION;
291 }
292 }
293
294 } else {
295
296 if (IsMillerModulationNibble1(Uart.twoBits >> Uart.syncBit)) {
297 if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation in both halves - error
298 UartReset();
299 Uart.highCnt = 6;
300 } else { // Modulation in first half = Sequence Z = logic "0"
301 if (Uart.state == STATE_MILLER_X) { // error - must not follow after X
302 UartReset();
303 Uart.highCnt = 6;
304 } else {
305 Uart.bitCount++;
306 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
307 Uart.state = STATE_MILLER_Z;
308 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
309 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
310 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
311 Uart.parityBits <<= 1; // make room for the parity bit
312 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
313 Uart.bitCount = 0;
314 Uart.shiftReg = 0;
315 }
316 }
317 }
318 } else {
319 if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1"
320 Uart.bitCount++;
321 Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg
322 Uart.state = STATE_MILLER_X;
323 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
324 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
325 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
326 Uart.parityBits <<= 1; // make room for the new parity bit
327 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
328 Uart.bitCount = 0;
329 Uart.shiftReg = 0;
330 }
331 } else { // no modulation in both halves - Sequence Y
332 if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication
333 Uart.state = STATE_UNSYNCD;
334 if(Uart.len == 0 && Uart.bitCount > 0) { // if we decoded some bits
335 Uart.shiftReg >>= (9 - Uart.bitCount); // add them to the output
336 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
337 Uart.parityBits <<= 1; // no parity bit - add "0"
338 Uart.bitCount--; // last "0" was part of the EOC sequence
339 }
340 return TRUE;
341 }
342 if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC
343 UartReset();
344 Uart.highCnt = 6;
345 } else { // a logic "0"
346 Uart.bitCount++;
347 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
348 Uart.state = STATE_MILLER_Y;
349 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
350 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
351 Uart.parityBits <<= 1; // make room for the parity bit
352 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
353 Uart.bitCount = 0;
354 Uart.shiftReg = 0;
355 }
356 }
357 }
358 }
359
360 }
361
362 return FALSE; // not finished yet, need more data
363 }
364
365
366
367 //=============================================================================
368 // ISO 14443 Type A - Manchester decoder
369 //=============================================================================
370 // Basics:
371 // This decoder is used when the PM3 acts as a reader.
372 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
373 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
374 // ........ 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 .......
375 // The Manchester decoder needs to identify the following sequences:
376 // 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication")
377 // 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0
378 // 8 ticks unmodulated: Sequence F = end of communication
379 // 8 ticks modulated: A collision. Save the collision position and treat as Sequence D
380 // Note 1: the bitstream may start at any time. We therefore need to sync.
381 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
382 static tDemod Demod;
383
384 // Lookup-Table to decide if 4 raw bits are a modulation.
385 // We accept three or four "1" in any position
386 const bool Mod_Manchester_LUT[] = {
387 FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
388 FALSE, FALSE, FALSE, TRUE, FALSE, TRUE, TRUE, TRUE
389 };
390
391 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
392 #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
393
394
395 void DemodReset()
396 {
397 Demod.state = DEMOD_UNSYNCD;
398 Demod.len = 0; // number of decoded data bytes
399 Demod.shiftReg = 0; // shiftreg to hold decoded data bits
400 Demod.parityBits = 0; //
401 Demod.collisionPos = 0; // Position of collision bit
402 Demod.twoBits = 0xffff; // buffer for 2 Bits
403 Demod.highCnt = 0;
404 Demod.startTime = 0;
405 Demod.endTime = 0;
406 }
407
408 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
409 static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
410 {
411
412 Demod.twoBits = (Demod.twoBits << 8) | bit;
413
414 if (Demod.state == DEMOD_UNSYNCD) {
415
416 if (Demod.highCnt < 2) { // wait for a stable unmodulated signal
417 if (Demod.twoBits == 0x0000) {
418 Demod.highCnt++;
419 } else {
420 Demod.highCnt = 0;
421 }
422 } else {
423 Demod.syncBit = 0xFFFF; // not set
424 if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
425 else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
426 else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
427 else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
428 else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
429 else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
430 else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
431 else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
432 if (Demod.syncBit != 0xFFFF) {
433 Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
434 Demod.startTime -= Demod.syncBit;
435 Demod.bitCount = offset; // number of decoded data bits
436 Demod.state = DEMOD_MANCHESTER_DATA;
437 }
438 }
439
440 } else {
441
442 if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half
443 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... and in second half = collision
444 if (!Demod.collisionPos) {
445 Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
446 }
447 } // modulation in first half only - Sequence D = 1
448 Demod.bitCount++;
449 Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg
450 if(Demod.bitCount == 9) { // if we decoded a full byte (including parity)
451 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
452 Demod.parityBits <<= 1; // make room for the parity bit
453 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
454 Demod.bitCount = 0;
455 Demod.shiftReg = 0;
456 }
457 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
458 } else { // no modulation in first half
459 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // and modulation in second half = Sequence E = 0
460 Demod.bitCount++;
461 Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg
462 if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity)
463 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
464 Demod.parityBits <<= 1; // make room for the new parity bit
465 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
466 Demod.bitCount = 0;
467 Demod.shiftReg = 0;
468 }
469 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
470 } else { // no modulation in both halves - End of communication
471 if (Demod.len > 0 || Demod.bitCount > 0) { // received something
472 if(Demod.bitCount > 0) { // if we decoded bits
473 Demod.shiftReg >>= (9 - Demod.bitCount); // add the remaining decoded bits to the output
474 Demod.output[Demod.len++] = Demod.shiftReg & 0xff;
475 // No parity bit, so just shift a 0
476 Demod.parityBits <<= 1;
477 }
478 return TRUE; // we are finished with decoding the raw data sequence
479 } else { // nothing received. Start over
480 DemodReset();
481 }
482 }
483 }
484
485 }
486
487 return FALSE; // not finished yet, need more data
488 }
489
490 //=============================================================================
491 // Finally, a `sniffer' for ISO 14443 Type A
492 // Both sides of communication!
493 //=============================================================================
494
495 //-----------------------------------------------------------------------------
496 // Record the sequence of commands sent by the reader to the tag, with
497 // triggering so that we start recording at the point that the tag is moved
498 // near the reader.
499 //-----------------------------------------------------------------------------
500 void RAMFUNC SnoopIso14443a(uint8_t param) {
501 // param:
502 // bit 0 - trigger from first card answer
503 // bit 1 - trigger from first reader 7-bit request
504
505 LEDsoff();
506 // init trace buffer
507 iso14a_clear_trace();
508
509 // We won't start recording the frames that we acquire until we trigger;
510 // a good trigger condition to get started is probably when we see a
511 // response from the tag.
512 // triggered == FALSE -- to wait first for card
513 bool triggered = !(param & 0x03);
514
515 // The command (reader -> tag) that we're receiving.
516 // The length of a received command will in most cases be no more than 18 bytes.
517 // So 32 should be enough!
518 uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
519 // The response (tag -> reader) that we're receiving.
520 uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
521
522 // As we receive stuff, we copy it from receivedCmd or receivedResponse
523 // into trace, along with its length and other annotations.
524 //uint8_t *trace = (uint8_t *)BigBuf;
525
526 // The DMA buffer, used to stream samples from the FPGA
527 uint8_t *dmaBuf = ((uint8_t *)BigBuf) + DMA_BUFFER_OFFSET;
528 uint8_t *data = dmaBuf;
529 uint8_t previous_data = 0;
530 int maxDataLen = 0;
531 int dataLen = 0;
532 bool TagIsActive = FALSE;
533 bool ReaderIsActive = FALSE;
534
535 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
536
537 // Set up the demodulator for tag -> reader responses.
538 Demod.output = receivedResponse;
539
540 // Set up the demodulator for the reader -> tag commands
541 Uart.output = receivedCmd;
542
543 // Setup and start DMA.
544 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
545
546 // And now we loop, receiving samples.
547 for(uint32_t rsamples = 0; TRUE; ) {
548
549 if(BUTTON_PRESS()) {
550 DbpString("cancelled by button");
551 break;
552 }
553
554 LED_A_ON();
555 WDT_HIT();
556
557 int register readBufDataP = data - dmaBuf;
558 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
559 if (readBufDataP <= dmaBufDataP){
560 dataLen = dmaBufDataP - readBufDataP;
561 } else {
562 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
563 }
564 // test for length of buffer
565 if(dataLen > maxDataLen) {
566 maxDataLen = dataLen;
567 if(dataLen > 400) {
568 Dbprintf("blew circular buffer! dataLen=%d", dataLen);
569 break;
570 }
571 }
572 if(dataLen < 1) continue;
573
574 // primary buffer was stopped( <-- we lost data!
575 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
576 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
577 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
578 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
579 }
580 // secondary buffer sets as primary, secondary buffer was stopped
581 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
582 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
583 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
584 }
585
586 LED_A_OFF();
587
588 if (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder
589
590 if(!TagIsActive) { // no need to try decoding reader data if the tag is sending
591 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
592 if (MillerDecoding(readerdata, (rsamples-1)*4)) {
593 LED_C_ON();
594
595 // check - if there is a short 7bit request from reader
596 if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
597
598 if(triggered) {
599 if (!LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, Uart.parityBits, TRUE)) break;
600 if (!LogTrace(NULL, 0, Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, 0, TRUE)) break;
601 }
602 /* And ready to receive another command. */
603 UartReset();
604 /* And also reset the demod code, which might have been */
605 /* false-triggered by the commands from the reader. */
606 DemodReset();
607 LED_B_OFF();
608 }
609 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
610 }
611
612 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time
613 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
614 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
615 LED_B_ON();
616
617 if (!LogTrace(receivedResponse, Demod.len, Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, Demod.parityBits, FALSE)) break;
618 if (!LogTrace(NULL, 0, Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, 0, FALSE)) break;
619
620 if ((!triggered) && (param & 0x01)) triggered = TRUE;
621
622 // And ready to receive another response.
623 DemodReset();
624 LED_C_OFF();
625 }
626 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
627 }
628 }
629
630 previous_data = *data;
631 rsamples++;
632 data++;
633 if(data == dmaBuf + DMA_BUFFER_SIZE) {
634 data = dmaBuf;
635 }
636 } // main cycle
637
638 DbpString("COMMAND FINISHED");
639
640 FpgaDisableSscDma();
641 Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
642 Dbprintf("traceLen=%d, Uart.output[0]=%08x", traceLen, (uint32_t)Uart.output[0]);
643 LEDsoff();
644 }
645
646 //-----------------------------------------------------------------------------
647 // Prepare tag messages
648 //-----------------------------------------------------------------------------
649 static void CodeIso14443aAsTagPar(const uint8_t *cmd, int len, uint32_t dwParity)
650 {
651 int i;
652
653 ToSendReset();
654
655 // Correction bit, might be removed when not needed
656 ToSendStuffBit(0);
657 ToSendStuffBit(0);
658 ToSendStuffBit(0);
659 ToSendStuffBit(0);
660 ToSendStuffBit(1); // 1
661 ToSendStuffBit(0);
662 ToSendStuffBit(0);
663 ToSendStuffBit(0);
664
665 // Send startbit
666 ToSend[++ToSendMax] = SEC_D;
667 LastProxToAirDuration = 8 * ToSendMax - 4;
668
669 for(i = 0; i < len; i++) {
670 int j;
671 uint8_t b = cmd[i];
672
673 // Data bits
674 for(j = 0; j < 8; j++) {
675 if(b & 1) {
676 ToSend[++ToSendMax] = SEC_D;
677 } else {
678 ToSend[++ToSendMax] = SEC_E;
679 }
680 b >>= 1;
681 }
682
683 // Get the parity bit
684 if ((dwParity >> i) & 0x01) {
685 ToSend[++ToSendMax] = SEC_D;
686 LastProxToAirDuration = 8 * ToSendMax - 4;
687 } else {
688 ToSend[++ToSendMax] = SEC_E;
689 LastProxToAirDuration = 8 * ToSendMax;
690 }
691 }
692
693 // Send stopbit
694 ToSend[++ToSendMax] = SEC_F;
695
696 // Convert from last byte pos to length
697 ToSendMax++;
698 }
699
700 static void CodeIso14443aAsTag(const uint8_t *cmd, int len){
701 CodeIso14443aAsTagPar(cmd, len, GetParity(cmd, len));
702 }
703
704
705 static void Code4bitAnswerAsTag(uint8_t cmd)
706 {
707 int i;
708
709 ToSendReset();
710
711 // Correction bit, might be removed when not needed
712 ToSendStuffBit(0);
713 ToSendStuffBit(0);
714 ToSendStuffBit(0);
715 ToSendStuffBit(0);
716 ToSendStuffBit(1); // 1
717 ToSendStuffBit(0);
718 ToSendStuffBit(0);
719 ToSendStuffBit(0);
720
721 // Send startbit
722 ToSend[++ToSendMax] = SEC_D;
723
724 uint8_t b = cmd;
725 for(i = 0; i < 4; i++) {
726 if(b & 1) {
727 ToSend[++ToSendMax] = SEC_D;
728 LastProxToAirDuration = 8 * ToSendMax - 4;
729 } else {
730 ToSend[++ToSendMax] = SEC_E;
731 LastProxToAirDuration = 8 * ToSendMax;
732 }
733 b >>= 1;
734 }
735
736 // Send stopbit
737 ToSend[++ToSendMax] = SEC_F;
738
739 // Convert from last byte pos to length
740 ToSendMax++;
741 }
742
743 //-----------------------------------------------------------------------------
744 // Wait for commands from reader
745 // Stop when button is pressed
746 // Or return TRUE when command is captured
747 //-----------------------------------------------------------------------------
748 static int GetIso14443aCommandFromReader(uint8_t *received, int *len, int maxLen)
749 {
750 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
751 // only, since we are receiving, not transmitting).
752 // Signal field is off with the appropriate LED
753 LED_D_OFF();
754 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
755
756 // Now run a `software UART' on the stream of incoming samples.
757 UartReset();
758 Uart.output = received;
759
760 // clear RXRDY:
761 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
762
763 for(;;) {
764 WDT_HIT();
765
766 if(BUTTON_PRESS()) return FALSE;
767
768 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
769 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
770 if(MillerDecoding(b, 0)) {
771 *len = Uart.len;
772 return TRUE;
773 }
774 }
775 }
776 }
777
778 static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, bool correctionNeeded);
779 int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
780 int EmSend4bit(uint8_t resp);
781 int EmSendCmdExPar(uint8_t *resp, int respLen, bool correctionNeeded, uint32_t par);
782 int EmSendCmdExPar(uint8_t *resp, int respLen, bool correctionNeeded, uint32_t par);
783 int EmSendCmdEx(uint8_t *resp, int respLen, bool correctionNeeded);
784 int EmSendCmd(uint8_t *resp, int respLen);
785 int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par);
786 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint32_t reader_Parity,
787 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint32_t tag_Parity);
788
789 static uint8_t* free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
790
791 typedef struct {
792 uint8_t* response;
793 size_t response_n;
794 uint8_t* modulation;
795 size_t modulation_n;
796 uint32_t ProxToAirDuration;
797 } tag_response_info_t;
798
799 void reset_free_buffer() {
800 free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
801 }
802
803 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
804 // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
805 // This will need the following byte array for a modulation sequence
806 // 144 data bits (18 * 8)
807 // 18 parity bits
808 // 2 Start and stop
809 // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA)
810 // 1 just for the case
811 // ----------- +
812 // 166 bytes, since every bit that needs to be send costs us a byte
813 //
814
815 // Prepare the tag modulation bits from the message
816 CodeIso14443aAsTag(response_info->response,response_info->response_n);
817
818 // Make sure we do not exceed the free buffer space
819 if (ToSendMax > max_buffer_size) {
820 Dbprintf("Out of memory, when modulating bits for tag answer:");
821 Dbhexdump(response_info->response_n,response_info->response,false);
822 return false;
823 }
824
825 // Copy the byte array, used for this modulation to the buffer position
826 memcpy(response_info->modulation,ToSend,ToSendMax);
827
828 // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
829 response_info->modulation_n = ToSendMax;
830 response_info->ProxToAirDuration = LastProxToAirDuration;
831
832 return true;
833 }
834
835 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
836 // Retrieve and store the current buffer index
837 response_info->modulation = free_buffer_pointer;
838
839 // Determine the maximum size we can use from our buffer
840 size_t max_buffer_size = (((uint8_t *)BigBuf)+FREE_BUFFER_OFFSET+FREE_BUFFER_SIZE)-free_buffer_pointer;
841
842 // Forward the prepare tag modulation function to the inner function
843 if (prepare_tag_modulation(response_info,max_buffer_size)) {
844 // Update the free buffer offset
845 free_buffer_pointer += ToSendMax;
846 return true;
847 } else {
848 return false;
849 }
850 }
851
852 //-----------------------------------------------------------------------------
853 // Main loop of simulated tag: receive commands from reader, decide what
854 // response to send, and send it.
855 //-----------------------------------------------------------------------------
856 void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
857 {
858 // Enable and clear the trace
859 iso14a_clear_trace();
860 iso14a_set_tracing(TRUE);
861
862 uint8_t sak;
863
864 // The first response contains the ATQA (note: bytes are transmitted in reverse order).
865 uint8_t response1[2];
866
867 switch (tagType) {
868 case 1: { // MIFARE Classic
869 // Says: I am Mifare 1k - original line
870 response1[0] = 0x04;
871 response1[1] = 0x00;
872 sak = 0x08;
873 } break;
874 case 2: { // MIFARE Ultralight
875 // Says: I am a stupid memory tag, no crypto
876 response1[0] = 0x04;
877 response1[1] = 0x00;
878 sak = 0x00;
879 } break;
880 case 3: { // MIFARE DESFire
881 // Says: I am a DESFire tag, ph33r me
882 response1[0] = 0x04;
883 response1[1] = 0x03;
884 sak = 0x20;
885 } break;
886 case 4: { // ISO/IEC 14443-4
887 // Says: I am a javacard (JCOP)
888 response1[0] = 0x04;
889 response1[1] = 0x00;
890 sak = 0x28;
891 } break;
892 default: {
893 Dbprintf("Error: unkown tagtype (%d)",tagType);
894 return;
895 } break;
896 }
897
898 // The second response contains the (mandatory) first 24 bits of the UID
899 uint8_t response2[5];
900
901 // Check if the uid uses the (optional) part
902 uint8_t response2a[5];
903 if (uid_2nd) {
904 response2[0] = 0x88;
905 num_to_bytes(uid_1st,3,response2+1);
906 num_to_bytes(uid_2nd,4,response2a);
907 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
908
909 // Configure the ATQA and SAK accordingly
910 response1[0] |= 0x40;
911 sak |= 0x04;
912 } else {
913 num_to_bytes(uid_1st,4,response2);
914 // Configure the ATQA and SAK accordingly
915 response1[0] &= 0xBF;
916 sak &= 0xFB;
917 }
918
919 // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
920 response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
921
922 // Prepare the mandatory SAK (for 4 and 7 byte UID)
923 uint8_t response3[3];
924 response3[0] = sak;
925 ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
926
927 // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
928 uint8_t response3a[3];
929 response3a[0] = sak & 0xFB;
930 ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
931
932 uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
933 uint8_t response6[] = { 0x04, 0x58, 0x00, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS
934 ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
935
936 #define TAG_RESPONSE_COUNT 7
937 tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
938 { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type
939 { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid
940 { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked
941 { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1
942 { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2
943 { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce)
944 { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS
945 };
946
947 // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
948 // Such a response is less time critical, so we can prepare them on the fly
949 #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
950 #define DYNAMIC_MODULATION_BUFFER_SIZE 512
951 uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
952 uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
953 tag_response_info_t dynamic_response_info = {
954 .response = dynamic_response_buffer,
955 .response_n = 0,
956 .modulation = dynamic_modulation_buffer,
957 .modulation_n = 0
958 };
959
960 // Reset the offset pointer of the free buffer
961 reset_free_buffer();
962
963 // Prepare the responses of the anticollision phase
964 // there will be not enough time to do this at the moment the reader sends it REQA
965 for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
966 prepare_allocated_tag_modulation(&responses[i]);
967 }
968
969 uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
970 int len = 0;
971
972 // To control where we are in the protocol
973 int order = 0;
974 int lastorder;
975
976 // Just to allow some checks
977 int happened = 0;
978 int happened2 = 0;
979 int cmdsRecvd = 0;
980
981 // We need to listen to the high-frequency, peak-detected path.
982 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
983
984 cmdsRecvd = 0;
985 tag_response_info_t* p_response;
986
987 LED_A_ON();
988 for(;;) {
989 // Clean receive command buffer
990
991 if(!GetIso14443aCommandFromReader(receivedCmd, &len, RECV_CMD_SIZE)) {
992 DbpString("Button press");
993 break;
994 }
995
996 p_response = NULL;
997
998 // 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
999 // Okay, look at the command now.
1000 lastorder = order;
1001 if(receivedCmd[0] == 0x26) { // Received a REQUEST
1002 p_response = &responses[0]; order = 1;
1003 } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
1004 p_response = &responses[0]; order = 6;
1005 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // Received request for UID (cascade 1)
1006 p_response = &responses[1]; order = 2;
1007 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2)
1008 p_response = &responses[2]; order = 20;
1009 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) { // Received a SELECT (cascade 1)
1010 p_response = &responses[3]; order = 3;
1011 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) { // Received a SELECT (cascade 2)
1012 p_response = &responses[4]; order = 30;
1013 } else if(receivedCmd[0] == 0x30) { // Received a (plain) READ
1014 EmSendCmdEx(data+(4*receivedCmd[0]),16,false);
1015 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1016 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1017 p_response = NULL;
1018 } else if(receivedCmd[0] == 0x50) { // Received a HALT
1019 // DbpString("Reader requested we HALT!:");
1020 if (tracing) {
1021 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
1022 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
1023 }
1024 p_response = NULL;
1025 } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) { // Received an authentication request
1026 p_response = &responses[5]; order = 7;
1027 } else if(receivedCmd[0] == 0xE0) { // Received a RATS request
1028 if (tagType == 1 || tagType == 2) { // RATS not supported
1029 EmSend4bit(CARD_NACK_NA);
1030 p_response = NULL;
1031 } else {
1032 p_response = &responses[6]; order = 70;
1033 }
1034 } else if (order == 7 && len == 8) { // Received authentication request
1035 if (tracing) {
1036 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
1037 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
1038 }
1039 uint32_t nr = bytes_to_num(receivedCmd,4);
1040 uint32_t ar = bytes_to_num(receivedCmd+4,4);
1041 Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar);
1042 } else {
1043 // Check for ISO 14443A-4 compliant commands, look at left nibble
1044 switch (receivedCmd[0]) {
1045
1046 case 0x0B:
1047 case 0x0A: { // IBlock (command)
1048 dynamic_response_info.response[0] = receivedCmd[0];
1049 dynamic_response_info.response[1] = 0x00;
1050 dynamic_response_info.response[2] = 0x90;
1051 dynamic_response_info.response[3] = 0x00;
1052 dynamic_response_info.response_n = 4;
1053 } break;
1054
1055 case 0x1A:
1056 case 0x1B: { // Chaining command
1057 dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1058 dynamic_response_info.response_n = 2;
1059 } break;
1060
1061 case 0xaa:
1062 case 0xbb: {
1063 dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1064 dynamic_response_info.response_n = 2;
1065 } break;
1066
1067 case 0xBA: { //
1068 memcpy(dynamic_response_info.response,"\xAB\x00",2);
1069 dynamic_response_info.response_n = 2;
1070 } break;
1071
1072 case 0xCA:
1073 case 0xC2: { // Readers sends deselect command
1074 memcpy(dynamic_response_info.response,"\xCA\x00",2);
1075 dynamic_response_info.response_n = 2;
1076 } break;
1077
1078 default: {
1079 // Never seen this command before
1080 if (tracing) {
1081 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
1082 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
1083 }
1084 Dbprintf("Received unknown command (len=%d):",len);
1085 Dbhexdump(len,receivedCmd,false);
1086 // Do not respond
1087 dynamic_response_info.response_n = 0;
1088 } break;
1089 }
1090
1091 if (dynamic_response_info.response_n > 0) {
1092 // Copy the CID from the reader query
1093 dynamic_response_info.response[1] = receivedCmd[1];
1094
1095 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1096 AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
1097 dynamic_response_info.response_n += 2;
1098
1099 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1100 Dbprintf("Error preparing tag response");
1101 if (tracing) {
1102 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
1103 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
1104 }
1105 break;
1106 }
1107 p_response = &dynamic_response_info;
1108 }
1109 }
1110
1111 // Count number of wakeups received after a halt
1112 if(order == 6 && lastorder == 5) { happened++; }
1113
1114 // Count number of other messages after a halt
1115 if(order != 6 && lastorder == 5) { happened2++; }
1116
1117 if(cmdsRecvd > 999) {
1118 DbpString("1000 commands later...");
1119 break;
1120 }
1121 cmdsRecvd++;
1122
1123 if (p_response != NULL) {
1124 EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1125 // do the tracing for the previous reader request and this tag answer:
1126 EmLogTrace(Uart.output,
1127 Uart.len,
1128 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1129 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1130 Uart.parityBits,
1131 p_response->response,
1132 p_response->response_n,
1133 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1134 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1135 SwapBits(GetParity(p_response->response, p_response->response_n), p_response->response_n));
1136 }
1137
1138 if (!tracing) {
1139 Dbprintf("Trace Full. Simulation stopped.");
1140 break;
1141 }
1142 }
1143
1144 Dbprintf("%x %x %x", happened, happened2, cmdsRecvd);
1145 LED_A_OFF();
1146 }
1147
1148
1149 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1150 // of bits specified in the delay parameter.
1151 void PrepareDelayedTransfer(uint16_t delay)
1152 {
1153 uint8_t bitmask = 0;
1154 uint8_t bits_to_shift = 0;
1155 uint8_t bits_shifted = 0;
1156
1157 delay &= 0x07;
1158 if (delay) {
1159 for (uint16_t i = 0; i < delay; i++) {
1160 bitmask |= (0x01 << i);
1161 }
1162 ToSend[ToSendMax++] = 0x00;
1163 for (uint16_t i = 0; i < ToSendMax; i++) {
1164 bits_to_shift = ToSend[i] & bitmask;
1165 ToSend[i] = ToSend[i] >> delay;
1166 ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1167 bits_shifted = bits_to_shift;
1168 }
1169 }
1170 }
1171
1172
1173 //-------------------------------------------------------------------------------------
1174 // Transmit the command (to the tag) that was placed in ToSend[].
1175 // Parameter timing:
1176 // if NULL: transfer at next possible time, taking into account
1177 // request guard time and frame delay time
1178 // if == 0: transfer immediately and return time of transfer
1179 // if != 0: delay transfer until time specified
1180 //-------------------------------------------------------------------------------------
1181 static void TransmitFor14443a(const uint8_t *cmd, int len, uint32_t *timing)
1182 {
1183
1184 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1185
1186 uint32_t ThisTransferTime = 0;
1187
1188 if (timing) {
1189 if(*timing == 0) { // Measure time
1190 *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1191 } else {
1192 PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
1193 }
1194 if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
1195 while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
1196 LastTimeProxToAirStart = *timing;
1197 } else {
1198 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1199 while(GetCountSspClk() < ThisTransferTime);
1200 LastTimeProxToAirStart = ThisTransferTime;
1201 }
1202
1203 // clear TXRDY
1204 AT91C_BASE_SSC->SSC_THR = SEC_Y;
1205
1206 // for(uint16_t c = 0; c < 10;) { // standard delay for each transfer (allow tag to be ready after last transmission)
1207 // if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1208 // AT91C_BASE_SSC->SSC_THR = SEC_Y;
1209 // c++;
1210 // }
1211 // }
1212
1213 uint16_t c = 0;
1214 for(;;) {
1215 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1216 AT91C_BASE_SSC->SSC_THR = cmd[c];
1217 c++;
1218 if(c >= len) {
1219 break;
1220 }
1221 }
1222 }
1223
1224 NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1225
1226 }
1227
1228
1229 //-----------------------------------------------------------------------------
1230 // Prepare reader command (in bits, support short frames) to send to FPGA
1231 //-----------------------------------------------------------------------------
1232 void CodeIso14443aBitsAsReaderPar(const uint8_t * cmd, int bits, uint32_t dwParity)
1233 {
1234 int i, j;
1235 int last;
1236 uint8_t b;
1237
1238 ToSendReset();
1239
1240 // Start of Communication (Seq. Z)
1241 ToSend[++ToSendMax] = SEC_Z;
1242 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1243 last = 0;
1244
1245 size_t bytecount = nbytes(bits);
1246 // Generate send structure for the data bits
1247 for (i = 0; i < bytecount; i++) {
1248 // Get the current byte to send
1249 b = cmd[i];
1250 size_t bitsleft = MIN((bits-(i*8)),8);
1251
1252 for (j = 0; j < bitsleft; j++) {
1253 if (b & 1) {
1254 // Sequence X
1255 ToSend[++ToSendMax] = SEC_X;
1256 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1257 last = 1;
1258 } else {
1259 if (last == 0) {
1260 // Sequence Z
1261 ToSend[++ToSendMax] = SEC_Z;
1262 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1263 } else {
1264 // Sequence Y
1265 ToSend[++ToSendMax] = SEC_Y;
1266 last = 0;
1267 }
1268 }
1269 b >>= 1;
1270 }
1271
1272 // Only transmit (last) parity bit if we transmitted a complete byte
1273 if (j == 8) {
1274 // Get the parity bit
1275 if ((dwParity >> i) & 0x01) {
1276 // Sequence X
1277 ToSend[++ToSendMax] = SEC_X;
1278 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1279 last = 1;
1280 } else {
1281 if (last == 0) {
1282 // Sequence Z
1283 ToSend[++ToSendMax] = SEC_Z;
1284 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1285 } else {
1286 // Sequence Y
1287 ToSend[++ToSendMax] = SEC_Y;
1288 last = 0;
1289 }
1290 }
1291 }
1292 }
1293
1294 // End of Communication: Logic 0 followed by Sequence Y
1295 if (last == 0) {
1296 // Sequence Z
1297 ToSend[++ToSendMax] = SEC_Z;
1298 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1299 } else {
1300 // Sequence Y
1301 ToSend[++ToSendMax] = SEC_Y;
1302 last = 0;
1303 }
1304 ToSend[++ToSendMax] = SEC_Y;
1305
1306 // Convert to length of command:
1307 ToSendMax++;
1308 }
1309
1310 //-----------------------------------------------------------------------------
1311 // Prepare reader command to send to FPGA
1312 //-----------------------------------------------------------------------------
1313 void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity)
1314 {
1315 CodeIso14443aBitsAsReaderPar(cmd,len*8,dwParity);
1316 }
1317
1318 //-----------------------------------------------------------------------------
1319 // Wait for commands from reader
1320 // Stop when button is pressed (return 1) or field was gone (return 2)
1321 // Or return 0 when command is captured
1322 //-----------------------------------------------------------------------------
1323 static int EmGetCmd(uint8_t *received, int *len)
1324 {
1325 *len = 0;
1326
1327 uint32_t timer = 0, vtime = 0;
1328 int analogCnt = 0;
1329 int analogAVG = 0;
1330
1331 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1332 // only, since we are receiving, not transmitting).
1333 // Signal field is off with the appropriate LED
1334 LED_D_OFF();
1335 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1336
1337 // Set ADC to read field strength
1338 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1339 AT91C_BASE_ADC->ADC_MR =
1340 ADC_MODE_PRESCALE(32) |
1341 ADC_MODE_STARTUP_TIME(16) |
1342 ADC_MODE_SAMPLE_HOLD_TIME(8);
1343 AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1344 // start ADC
1345 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1346
1347 // Now run a 'software UART' on the stream of incoming samples.
1348 UartReset();
1349 Uart.output = received;
1350
1351 // Clear RXRDY:
1352 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1353
1354 for(;;) {
1355 WDT_HIT();
1356
1357 if (BUTTON_PRESS()) return 1;
1358
1359 // test if the field exists
1360 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1361 analogCnt++;
1362 analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1363 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1364 if (analogCnt >= 32) {
1365 if ((33000 * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1366 vtime = GetTickCount();
1367 if (!timer) timer = vtime;
1368 // 50ms no field --> card to idle state
1369 if (vtime - timer > 50) return 2;
1370 } else
1371 if (timer) timer = 0;
1372 analogCnt = 0;
1373 analogAVG = 0;
1374 }
1375 }
1376
1377 // receive and test the miller decoding
1378 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1379 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1380 if(MillerDecoding(b, 0)) {
1381 *len = Uart.len;
1382 return 0;
1383 }
1384 }
1385
1386 }
1387 }
1388
1389
1390 static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, bool correctionNeeded)
1391 {
1392 uint8_t b;
1393 uint16_t i = 0;
1394 uint32_t ThisTransferTime;
1395
1396 // Modulate Manchester
1397 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1398
1399 // include correction bit if necessary
1400 if (Uart.parityBits & 0x01) {
1401 correctionNeeded = TRUE;
1402 }
1403 if(correctionNeeded) {
1404 // 1236, so correction bit needed
1405 i = 0;
1406 } else {
1407 i = 1;
1408 }
1409
1410 // clear receiving shift register and holding register
1411 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1412 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1413 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1414 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1415
1416 // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1417 for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never
1418 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1419 if (AT91C_BASE_SSC->SSC_RHR) break;
1420 }
1421
1422 while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1423
1424 // Clear TXRDY:
1425 AT91C_BASE_SSC->SSC_THR = SEC_F;
1426
1427 // send cycle
1428 for(; i <= respLen; ) {
1429 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1430 AT91C_BASE_SSC->SSC_THR = resp[i++];
1431 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1432 }
1433
1434 if(BUTTON_PRESS()) {
1435 break;
1436 }
1437 }
1438
1439 // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1440 for (i = 0; i < 2 ; ) {
1441 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1442 AT91C_BASE_SSC->SSC_THR = SEC_F;
1443 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1444 i++;
1445 }
1446 }
1447
1448 LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
1449
1450 return 0;
1451 }
1452
1453 int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
1454 Code4bitAnswerAsTag(resp);
1455 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1456 // do the tracing for the previous reader request and this tag answer:
1457 EmLogTrace(Uart.output,
1458 Uart.len,
1459 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1460 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1461 Uart.parityBits,
1462 &resp,
1463 1,
1464 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1465 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1466 SwapBits(GetParity(&resp, 1), 1));
1467 return res;
1468 }
1469
1470 int EmSend4bit(uint8_t resp){
1471 return EmSend4bitEx(resp, false);
1472 }
1473
1474 int EmSendCmdExPar(uint8_t *resp, int respLen, bool correctionNeeded, uint32_t par){
1475 CodeIso14443aAsTagPar(resp, respLen, par);
1476 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1477 // do the tracing for the previous reader request and this tag answer:
1478 EmLogTrace(Uart.output,
1479 Uart.len,
1480 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1481 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1482 Uart.parityBits,
1483 resp,
1484 respLen,
1485 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1486 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1487 SwapBits(GetParity(resp, respLen), respLen));
1488 return res;
1489 }
1490
1491 int EmSendCmdEx(uint8_t *resp, int respLen, bool correctionNeeded){
1492 return EmSendCmdExPar(resp, respLen, correctionNeeded, GetParity(resp, respLen));
1493 }
1494
1495 int EmSendCmd(uint8_t *resp, int respLen){
1496 return EmSendCmdExPar(resp, respLen, false, GetParity(resp, respLen));
1497 }
1498
1499 int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par){
1500 return EmSendCmdExPar(resp, respLen, false, par);
1501 }
1502
1503 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint32_t reader_Parity,
1504 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint32_t tag_Parity)
1505 {
1506 if (tracing) {
1507 // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1508 // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1509 // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1510 uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1511 uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1512 uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1513 reader_EndTime = tag_StartTime - exact_fdt;
1514 reader_StartTime = reader_EndTime - reader_modlen;
1515 if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_Parity, TRUE)) {
1516 return FALSE;
1517 } else if (!LogTrace(NULL, 0, reader_EndTime, 0, TRUE)) {
1518 return FALSE;
1519 } else if (!LogTrace(tag_data, tag_len, tag_StartTime, tag_Parity, FALSE)) {
1520 return FALSE;
1521 } else {
1522 return (!LogTrace(NULL, 0, tag_EndTime, 0, FALSE));
1523 }
1524 } else {
1525 return TRUE;
1526 }
1527 }
1528
1529 //-----------------------------------------------------------------------------
1530 // Wait a certain time for tag response
1531 // If a response is captured return TRUE
1532 // If it takes too long return FALSE
1533 //-----------------------------------------------------------------------------
1534 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint16_t offset, int maxLen)
1535 {
1536 uint16_t c;
1537
1538 // Set FPGA mode to "reader listen mode", no modulation (listen
1539 // only, since we are receiving, not transmitting).
1540 // Signal field is on with the appropriate LED
1541 LED_D_ON();
1542 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1543
1544 // Now get the answer from the card
1545 DemodReset();
1546 Demod.output = receivedResponse;
1547
1548 // clear RXRDY:
1549 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1550
1551 c = 0;
1552 for(;;) {
1553 WDT_HIT();
1554
1555 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1556 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1557 if(ManchesterDecoding(b, offset, 0)) {
1558 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1559 return TRUE;
1560 } else if(c++ > iso14a_timeout) {
1561 return FALSE;
1562 }
1563 }
1564 }
1565 }
1566
1567 void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par, uint32_t *timing)
1568 {
1569
1570 CodeIso14443aBitsAsReaderPar(frame,bits,par);
1571
1572 // Send command to tag
1573 TransmitFor14443a(ToSend, ToSendMax, timing);
1574 if(trigger)
1575 LED_A_ON();
1576
1577 // Log reader command in trace buffer
1578 if (tracing) {
1579 LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
1580 LogTrace(NULL, 0, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, 0, TRUE);
1581 }
1582 }
1583
1584 void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par, uint32_t *timing)
1585 {
1586 ReaderTransmitBitsPar(frame,len*8,par, timing);
1587 }
1588
1589 void ReaderTransmitBits(uint8_t* frame, int len, uint32_t *timing)
1590 {
1591 // Generate parity and redirect
1592 ReaderTransmitBitsPar(frame,len,GetParity(frame,len/8), timing);
1593 }
1594
1595 void ReaderTransmit(uint8_t* frame, int len, uint32_t *timing)
1596 {
1597 // Generate parity and redirect
1598 ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len), timing);
1599 }
1600
1601 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset)
1602 {
1603 if (!GetIso14443aAnswerFromTag(receivedAnswer,offset,160)) return FALSE;
1604 if (tracing) {
1605 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.parityBits, FALSE);
1606 LogTrace(NULL, 0, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, 0, FALSE);
1607 }
1608 return Demod.len;
1609 }
1610
1611 int ReaderReceive(uint8_t* receivedAnswer)
1612 {
1613 return ReaderReceiveOffset(receivedAnswer, 0);
1614 }
1615
1616 int ReaderReceivePar(uint8_t *receivedAnswer, uint32_t *parptr)
1617 {
1618 if (!GetIso14443aAnswerFromTag(receivedAnswer,0,160)) return FALSE;
1619 if (tracing) {
1620 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.parityBits, FALSE);
1621 LogTrace(NULL, 0, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, 0, FALSE);
1622 }
1623 *parptr = Demod.parityBits;
1624 return Demod.len;
1625 }
1626
1627 /* performs iso14443a anticollision procedure
1628 * fills the uid pointer unless NULL
1629 * fills resp_data unless NULL */
1630 int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, uint32_t* cuid_ptr) {
1631 uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP
1632 uint8_t sel_all[] = { 0x93,0x20 };
1633 uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1634 uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1635 uint8_t* resp = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); // was 3560 - tied to other size changes
1636 byte_t uid_resp[4];
1637 size_t uid_resp_len;
1638
1639 uint8_t sak = 0x04; // cascade uid
1640 int cascade_level = 0;
1641 int len;
1642
1643 // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1644 ReaderTransmitBitsPar(wupa,7,0, NULL);
1645
1646 // Receive the ATQA
1647 if(!ReaderReceive(resp)) return 0;
1648 // Dbprintf("atqa: %02x %02x",resp[0],resp[1]);
1649
1650 if(p_hi14a_card) {
1651 memcpy(p_hi14a_card->atqa, resp, 2);
1652 p_hi14a_card->uidlen = 0;
1653 memset(p_hi14a_card->uid,0,10);
1654 }
1655
1656 // clear uid
1657 if (uid_ptr) {
1658 memset(uid_ptr,0,10);
1659 }
1660
1661 // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1662 // which case we need to make a cascade 2 request and select - this is a long UID
1663 // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1664 for(; sak & 0x04; cascade_level++) {
1665 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1666 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1667
1668 // SELECT_ALL
1669 ReaderTransmit(sel_all,sizeof(sel_all), NULL);
1670 if (!ReaderReceive(resp)) return 0;
1671
1672 if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit
1673 memset(uid_resp, 0, 4);
1674 uint16_t uid_resp_bits = 0;
1675 uint16_t collision_answer_offset = 0;
1676 // anti-collision-loop:
1677 while (Demod.collisionPos) {
1678 Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1679 for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point
1680 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1681 uid_resp[uid_resp_bits & 0xf8] |= UIDbit << (uid_resp_bits % 8);
1682 }
1683 uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position
1684 uid_resp_bits++;
1685 // construct anticollosion command:
1686 sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits
1687 for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1688 sel_uid[2+i] = uid_resp[i];
1689 }
1690 collision_answer_offset = uid_resp_bits%8;
1691 ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1692 if (!ReaderReceiveOffset(resp, collision_answer_offset)) return 0;
1693 }
1694 // finally, add the last bits and BCC of the UID
1695 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1696 uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1697 uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1698 }
1699
1700 } else { // no collision, use the response to SELECT_ALL as current uid
1701 memcpy(uid_resp,resp,4);
1702 }
1703 uid_resp_len = 4;
1704 // Dbprintf("uid: %02x %02x %02x %02x",uid_resp[0],uid_resp[1],uid_resp[2],uid_resp[3]);
1705
1706 // calculate crypto UID. Always use last 4 Bytes.
1707 if(cuid_ptr) {
1708 *cuid_ptr = bytes_to_num(uid_resp, 4);
1709 }
1710
1711 // Construct SELECT UID command
1712 sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1713 memcpy(sel_uid+2,uid_resp,4); // the UID
1714 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC
1715 AppendCrc14443a(sel_uid,7); // calculate and add CRC
1716 ReaderTransmit(sel_uid,sizeof(sel_uid), NULL);
1717
1718 // Receive the SAK
1719 if (!ReaderReceive(resp)) return 0;
1720 sak = resp[0];
1721
1722 // Test if more parts of the uid are comming
1723 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
1724 // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
1725 // http://www.nxp.com/documents/application_note/AN10927.pdf
1726 memcpy(uid_resp, uid_resp + 1, 3);
1727 uid_resp_len = 3;
1728 }
1729
1730 if(uid_ptr) {
1731 memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
1732 }
1733
1734 if(p_hi14a_card) {
1735 memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
1736 p_hi14a_card->uidlen += uid_resp_len;
1737 }
1738 }
1739
1740 if(p_hi14a_card) {
1741 p_hi14a_card->sak = sak;
1742 p_hi14a_card->ats_len = 0;
1743 }
1744
1745 if( (sak & 0x20) == 0) {
1746 return 2; // non iso14443a compliant tag
1747 }
1748
1749 // Request for answer to select
1750 AppendCrc14443a(rats, 2);
1751 ReaderTransmit(rats, sizeof(rats), NULL);
1752
1753 if (!(len = ReaderReceive(resp))) return 0;
1754
1755 if(p_hi14a_card) {
1756 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
1757 p_hi14a_card->ats_len = len;
1758 }
1759
1760 // reset the PCB block number
1761 iso14_pcb_blocknum = 0;
1762 return 1;
1763 }
1764
1765 void iso14443a_setup(uint8_t fpga_minor_mode) {
1766 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1767 // Set up the synchronous serial port
1768 FpgaSetupSsc();
1769 // connect Demodulated Signal to ADC:
1770 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1771
1772 // Signal field is on with the appropriate LED
1773 if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
1774 || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
1775 LED_D_ON();
1776 } else {
1777 LED_D_OFF();
1778 }
1779 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
1780
1781 // Start the timer
1782 StartCountSspClk();
1783
1784 DemodReset();
1785 UartReset();
1786 NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
1787 iso14a_set_timeout(1050); // 10ms default
1788 }
1789
1790 int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) {
1791 uint8_t real_cmd[cmd_len+4];
1792 real_cmd[0] = 0x0a; //I-Block
1793 // put block number into the PCB
1794 real_cmd[0] |= iso14_pcb_blocknum;
1795 real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
1796 memcpy(real_cmd+2, cmd, cmd_len);
1797 AppendCrc14443a(real_cmd,cmd_len+2);
1798
1799 ReaderTransmit(real_cmd, cmd_len+4, NULL);
1800 size_t len = ReaderReceive(data);
1801 uint8_t * data_bytes = (uint8_t *) data;
1802 if (!len)
1803 return 0; //DATA LINK ERROR
1804 // if we received an I- or R(ACK)-Block with a block number equal to the
1805 // current block number, toggle the current block number
1806 else if (len >= 4 // PCB+CID+CRC = 4 bytes
1807 && ((data_bytes[0] & 0xC0) == 0 // I-Block
1808 || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
1809 && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
1810 {
1811 iso14_pcb_blocknum ^= 1;
1812 }
1813
1814 return len;
1815 }
1816
1817 //-----------------------------------------------------------------------------
1818 // Read an ISO 14443a tag. Send out commands and store answers.
1819 //
1820 //-----------------------------------------------------------------------------
1821 void ReaderIso14443a(UsbCommand *c)
1822 {
1823 iso14a_command_t param = c->arg[0];
1824 uint8_t *cmd = c->d.asBytes;
1825 size_t len = c->arg[1];
1826 size_t lenbits = c->arg[2];
1827 uint32_t arg0 = 0;
1828 byte_t buf[USB_CMD_DATA_SIZE];
1829
1830 if(param & ISO14A_CONNECT) {
1831 iso14a_clear_trace();
1832 }
1833
1834 iso14a_set_tracing(TRUE);
1835
1836 if(param & ISO14A_REQUEST_TRIGGER) {
1837 iso14a_set_trigger(TRUE);
1838 }
1839
1840 if(param & ISO14A_CONNECT) {
1841 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
1842 if(!(param & ISO14A_NO_SELECT)) {
1843 iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
1844 arg0 = iso14443a_select_card(NULL,card,NULL);
1845 cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
1846 }
1847 }
1848
1849 if(param & ISO14A_SET_TIMEOUT) {
1850 iso14a_timeout = c->arg[2];
1851 }
1852
1853 if(param & ISO14A_APDU) {
1854 arg0 = iso14_apdu(cmd, len, buf);
1855 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
1856 }
1857
1858 if(param & ISO14A_RAW) {
1859 if(param & ISO14A_APPEND_CRC) {
1860 AppendCrc14443a(cmd,len);
1861 len += 2;
1862 }
1863 if(lenbits>0) {
1864 ReaderTransmitBitsPar(cmd,lenbits,GetParity(cmd,lenbits/8), NULL);
1865 } else {
1866 ReaderTransmit(cmd,len, NULL);
1867 }
1868 arg0 = ReaderReceive(buf);
1869 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
1870 }
1871
1872 if(param & ISO14A_REQUEST_TRIGGER) {
1873 iso14a_set_trigger(FALSE);
1874 }
1875
1876 if(param & ISO14A_NO_DISCONNECT) {
1877 return;
1878 }
1879
1880 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1881 LEDsoff();
1882 }
1883
1884
1885 // Determine the distance between two nonces.
1886 // Assume that the difference is small, but we don't know which is first.
1887 // Therefore try in alternating directions.
1888 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
1889
1890 uint16_t i;
1891 uint32_t nttmp1, nttmp2;
1892
1893 if (nt1 == nt2) return 0;
1894
1895 nttmp1 = nt1;
1896 nttmp2 = nt2;
1897
1898 for (i = 1; i < 32768; i++) {
1899 nttmp1 = prng_successor(nttmp1, 1);
1900 if (nttmp1 == nt2) return i;
1901 nttmp2 = prng_successor(nttmp2, 1);
1902 if (nttmp2 == nt1) return -i;
1903 }
1904
1905 return(-99999); // either nt1 or nt2 are invalid nonces
1906 }
1907
1908
1909 //-----------------------------------------------------------------------------
1910 // Recover several bits of the cypher stream. This implements (first stages of)
1911 // the algorithm described in "The Dark Side of Security by Obscurity and
1912 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
1913 // (article by Nicolas T. Courtois, 2009)
1914 //-----------------------------------------------------------------------------
1915 void ReaderMifare(bool first_try)
1916 {
1917 // Mifare AUTH
1918 uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b };
1919 uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
1920 static uint8_t mf_nr_ar3;
1921
1922 uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
1923
1924 iso14a_clear_trace();
1925 iso14a_set_tracing(TRUE);
1926
1927 byte_t nt_diff = 0;
1928 byte_t par = 0;
1929 //byte_t par_mask = 0xff;
1930 static byte_t par_low = 0;
1931 bool led_on = TRUE;
1932 uint8_t uid[10];
1933 uint32_t cuid;
1934
1935 uint32_t nt, previous_nt;
1936 static uint32_t nt_attacked = 0;
1937 byte_t par_list[8] = {0,0,0,0,0,0,0,0};
1938 byte_t ks_list[8] = {0,0,0,0,0,0,0,0};
1939
1940 static uint32_t sync_time;
1941 static uint32_t sync_cycles;
1942 int catch_up_cycles = 0;
1943 int last_catch_up = 0;
1944 uint16_t consecutive_resyncs = 0;
1945 int isOK = 0;
1946
1947
1948
1949 if (first_try) {
1950 mf_nr_ar3 = 0;
1951 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
1952 sync_time = GetCountSspClk() & 0xfffffff8;
1953 sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
1954 nt_attacked = 0;
1955 nt = 0;
1956 par = 0;
1957 }
1958 else {
1959 // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
1960 // nt_attacked = prng_successor(nt_attacked, 1);
1961 mf_nr_ar3++;
1962 mf_nr_ar[3] = mf_nr_ar3;
1963 par = par_low;
1964 }
1965
1966 LED_A_ON();
1967 LED_B_OFF();
1968 LED_C_OFF();
1969
1970
1971 for(uint16_t i = 0; TRUE; i++) {
1972
1973 WDT_HIT();
1974
1975 // Test if the action was cancelled
1976 if(BUTTON_PRESS()) {
1977 break;
1978 }
1979
1980 LED_C_ON();
1981
1982 if(!iso14443a_select_card(uid, NULL, &cuid)) {
1983 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
1984 continue;
1985 }
1986
1987 sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
1988 catch_up_cycles = 0;
1989
1990 // if we missed the sync time already, advance to the next nonce repeat
1991 while(GetCountSspClk() > sync_time) {
1992 sync_time = (sync_time & 0xfffffff8) + sync_cycles;
1993 }
1994
1995 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
1996 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
1997
1998 // Receive the (4 Byte) "random" nonce
1999 if (!ReaderReceive(receivedAnswer)) {
2000 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce");
2001 continue;
2002 }
2003
2004 previous_nt = nt;
2005 nt = bytes_to_num(receivedAnswer, 4);
2006
2007 // Transmit reader nonce with fake par
2008 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2009
2010 if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
2011 int nt_distance = dist_nt(previous_nt, nt);
2012 if (nt_distance == 0) {
2013 nt_attacked = nt;
2014 }
2015 else {
2016 if (nt_distance == -99999) { // invalid nonce received, try again
2017 continue;
2018 }
2019 sync_cycles = (sync_cycles - nt_distance);
2020 if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
2021 continue;
2022 }
2023 }
2024
2025 if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
2026 catch_up_cycles = -dist_nt(nt_attacked, nt);
2027 if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one.
2028 catch_up_cycles = 0;
2029 continue;
2030 }
2031 if (catch_up_cycles == last_catch_up) {
2032 consecutive_resyncs++;
2033 }
2034 else {
2035 last_catch_up = catch_up_cycles;
2036 consecutive_resyncs = 0;
2037 }
2038 if (consecutive_resyncs < 3) {
2039 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);
2040 }
2041 else {
2042 sync_cycles = sync_cycles + catch_up_cycles;
2043 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);
2044 }
2045 continue;
2046 }
2047
2048 consecutive_resyncs = 0;
2049
2050 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2051 if (ReaderReceive(receivedAnswer))
2052 {
2053 catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2054
2055 if (nt_diff == 0)
2056 {
2057 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
2058 }
2059
2060 led_on = !led_on;
2061 if(led_on) LED_B_ON(); else LED_B_OFF();
2062
2063 par_list[nt_diff] = par;
2064 ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
2065
2066 // Test if the information is complete
2067 if (nt_diff == 0x07) {
2068 isOK = 1;
2069 break;
2070 }
2071
2072 nt_diff = (nt_diff + 1) & 0x07;
2073 mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2074 par = par_low;
2075 } else {
2076 if (nt_diff == 0 && first_try)
2077 {
2078 par++;
2079 } else {
2080 par = (((par >> 3) + 1) << 3) | par_low;
2081 }
2082 }
2083 }
2084
2085
2086 mf_nr_ar[3] &= 0x1F;
2087
2088 byte_t buf[28];
2089 memcpy(buf + 0, uid, 4);
2090 num_to_bytes(nt, 4, buf + 4);
2091 memcpy(buf + 8, par_list, 8);
2092 memcpy(buf + 16, ks_list, 8);
2093 memcpy(buf + 24, mf_nr_ar, 4);
2094
2095 cmd_send(CMD_ACK,isOK,0,0,buf,28);
2096
2097 // Thats it...
2098 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2099 LEDsoff();
2100
2101 iso14a_set_tracing(FALSE);
2102 }
2103
2104 /**
2105 *MIFARE 1K simulate.
2106 *
2107 *@param flags :
2108 * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2109 * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
2110 * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
2111 * FLAG_NR_AR_ATTACK - means we should collect NR_AR responses for bruteforcing later
2112 *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2113 */
2114 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
2115 {
2116 int cardSTATE = MFEMUL_NOFIELD;
2117 int _7BUID = 0;
2118 int vHf = 0; // in mV
2119 int res;
2120 uint32_t selTimer = 0;
2121 uint32_t authTimer = 0;
2122 uint32_t par = 0;
2123 int len = 0;
2124 uint8_t cardWRBL = 0;
2125 uint8_t cardAUTHSC = 0;
2126 uint8_t cardAUTHKEY = 0xff; // no authentication
2127 uint32_t cardRr = 0;
2128 uint32_t cuid = 0;
2129 //uint32_t rn_enc = 0;
2130 uint32_t ans = 0;
2131 uint32_t cardINTREG = 0;
2132 uint8_t cardINTBLOCK = 0;
2133 struct Crypto1State mpcs = {0, 0};
2134 struct Crypto1State *pcs;
2135 pcs = &mpcs;
2136 uint32_t numReads = 0;//Counts numer of times reader read a block
2137 uint8_t* receivedCmd = eml_get_bigbufptr_recbuf();
2138 uint8_t *response = eml_get_bigbufptr_sendbuf();
2139
2140 uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
2141 uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2142 uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
2143 uint8_t rSAK[] = {0x08, 0xb6, 0xdd};
2144 uint8_t rSAK1[] = {0x04, 0xda, 0x17};
2145
2146 uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04};
2147 uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2148
2149 //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
2150 // This can be used in a reader-only attack.
2151 // (it can also be retrieved via 'hf 14a list', but hey...
2152 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
2153 uint8_t ar_nr_collected = 0;
2154
2155 // clear trace
2156 iso14a_clear_trace();
2157 iso14a_set_tracing(TRUE);
2158
2159 // Authenticate response - nonce
2160 uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2161
2162 //-- Determine the UID
2163 // Can be set from emulator memory, incoming data
2164 // and can be 7 or 4 bytes long
2165 if (flags & FLAG_4B_UID_IN_DATA)
2166 {
2167 // 4B uid comes from data-portion of packet
2168 memcpy(rUIDBCC1,datain,4);
2169 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2170
2171 } else if (flags & FLAG_7B_UID_IN_DATA) {
2172 // 7B uid comes from data-portion of packet
2173 memcpy(&rUIDBCC1[1],datain,3);
2174 memcpy(rUIDBCC2, datain+3, 4);
2175 _7BUID = true;
2176 } else {
2177 // get UID from emul memory
2178 emlGetMemBt(receivedCmd, 7, 1);
2179 _7BUID = !(receivedCmd[0] == 0x00);
2180 if (!_7BUID) { // ---------- 4BUID
2181 emlGetMemBt(rUIDBCC1, 0, 4);
2182 } else { // ---------- 7BUID
2183 emlGetMemBt(&rUIDBCC1[1], 0, 3);
2184 emlGetMemBt(rUIDBCC2, 3, 4);
2185 }
2186 }
2187
2188 /*
2189 * Regardless of what method was used to set the UID, set fifth byte and modify
2190 * the ATQA for 4 or 7-byte UID
2191 */
2192 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2193 if (_7BUID) {
2194 rATQA[0] = 0x44;
2195 rUIDBCC1[0] = 0x88;
2196 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2197 }
2198
2199 // We need to listen to the high-frequency, peak-detected path.
2200 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2201
2202
2203 if (MF_DBGLEVEL >= 1) {
2204 if (!_7BUID) {
2205 Dbprintf("4B UID: %02x%02x%02x%02x",rUIDBCC1[0] , rUIDBCC1[1] , rUIDBCC1[2] , rUIDBCC1[3]);
2206 } else {
2207 Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",rUIDBCC1[0] , rUIDBCC1[1] , rUIDBCC1[2] , rUIDBCC1[3],rUIDBCC2[0],rUIDBCC2[1] ,rUIDBCC2[2] , rUIDBCC2[3]);
2208 }
2209 }
2210
2211 bool finished = FALSE;
2212 while (!BUTTON_PRESS() && !finished) {
2213 WDT_HIT();
2214
2215 // find reader field
2216 // Vref = 3300mV, and an 10:1 voltage divider on the input
2217 // can measure voltages up to 33000 mV
2218 if (cardSTATE == MFEMUL_NOFIELD) {
2219 vHf = (33000 * AvgAdc(ADC_CHAN_HF)) >> 10;
2220 if (vHf > MF_MINFIELDV) {
2221 cardSTATE_TO_IDLE();
2222 LED_A_ON();
2223 }
2224 }
2225 if(cardSTATE == MFEMUL_NOFIELD) continue;
2226
2227 //Now, get data
2228
2229 res = EmGetCmd(receivedCmd, &len);
2230 if (res == 2) { //Field is off!
2231 cardSTATE = MFEMUL_NOFIELD;
2232 LEDsoff();
2233 continue;
2234 } else if (res == 1) {
2235 break; //return value 1 means button press
2236 }
2237
2238 // REQ or WUP request in ANY state and WUP in HALTED state
2239 if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
2240 selTimer = GetTickCount();
2241 EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
2242 cardSTATE = MFEMUL_SELECT1;
2243
2244 // init crypto block
2245 LED_B_OFF();
2246 LED_C_OFF();
2247 crypto1_destroy(pcs);
2248 cardAUTHKEY = 0xff;
2249 continue;
2250 }
2251
2252 switch (cardSTATE) {
2253 case MFEMUL_NOFIELD:
2254 case MFEMUL_HALTED:
2255 case MFEMUL_IDLE:{
2256 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2257 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2258 break;
2259 }
2260 case MFEMUL_SELECT1:{
2261 // select all
2262 if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
2263 if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received");
2264 EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2265 break;
2266 }
2267
2268 if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
2269 {
2270 Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
2271 }
2272 // select card
2273 if (len == 9 &&
2274 (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2275 EmSendCmd(_7BUID?rSAK1:rSAK, sizeof(_7BUID?rSAK1:rSAK));
2276 cuid = bytes_to_num(rUIDBCC1, 4);
2277 if (!_7BUID) {
2278 cardSTATE = MFEMUL_WORK;
2279 LED_B_ON();
2280 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2281 break;
2282 } else {
2283 cardSTATE = MFEMUL_SELECT2;
2284 }
2285 }
2286 break;
2287 }
2288 case MFEMUL_AUTH1:{
2289 if( len != 8)
2290 {
2291 cardSTATE_TO_IDLE();
2292 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2293 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2294 break;
2295 }
2296 uint32_t ar = bytes_to_num(receivedCmd, 4);
2297 uint32_t nr= bytes_to_num(&receivedCmd[4], 4);
2298
2299 //Collect AR/NR
2300 if(ar_nr_collected < 2){
2301 if(ar_nr_responses[2] != ar)
2302 {// Avoid duplicates... probably not necessary, ar should vary.
2303 ar_nr_responses[ar_nr_collected*4] = cuid;
2304 ar_nr_responses[ar_nr_collected*4+1] = nonce;
2305 ar_nr_responses[ar_nr_collected*4+2] = ar;
2306 ar_nr_responses[ar_nr_collected*4+3] = nr;
2307 ar_nr_collected++;
2308 }
2309 }
2310
2311 // --- crypto
2312 crypto1_word(pcs, ar , 1);
2313 cardRr = nr ^ crypto1_word(pcs, 0, 0);
2314
2315 // test if auth OK
2316 if (cardRr != prng_successor(nonce, 64)){
2317 if (MF_DBGLEVEL >= 2) Dbprintf("AUTH FAILED. cardRr=%08x, succ=%08x",cardRr, prng_successor(nonce, 64));
2318 // Shouldn't we respond anything here?
2319 // Right now, we don't nack or anything, which causes the
2320 // reader to do a WUPA after a while. /Martin
2321 cardSTATE_TO_IDLE();
2322 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2323 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2324 break;
2325 }
2326
2327 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2328
2329 num_to_bytes(ans, 4, rAUTH_AT);
2330 // --- crypto
2331 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2332 LED_C_ON();
2333 cardSTATE = MFEMUL_WORK;
2334 if (MF_DBGLEVEL >= 4) Dbprintf("AUTH COMPLETED. sector=%d, key=%d time=%d", cardAUTHSC, cardAUTHKEY, GetTickCount() - authTimer);
2335 break;
2336 }
2337 case MFEMUL_SELECT2:{
2338 if (!len) {
2339 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2340 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2341 break;
2342 }
2343 if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
2344 EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2345 break;
2346 }
2347
2348 // select 2 card
2349 if (len == 9 &&
2350 (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
2351 EmSendCmd(rSAK, sizeof(rSAK));
2352 cuid = bytes_to_num(rUIDBCC2, 4);
2353 cardSTATE = MFEMUL_WORK;
2354 LED_B_ON();
2355 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2356 break;
2357 }
2358
2359 // i guess there is a command). go into the work state.
2360 if (len != 4) {
2361 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2362 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2363 break;
2364 }
2365 cardSTATE = MFEMUL_WORK;
2366 //goto lbWORK;
2367 //intentional fall-through to the next case-stmt
2368 }
2369
2370 case MFEMUL_WORK:{
2371 if (len == 0) {
2372 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2373 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2374 break;
2375 }
2376
2377 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2378
2379 if(encrypted_data) {
2380 // decrypt seqence
2381 mf_crypto1_decrypt(pcs, receivedCmd, len);
2382 }
2383
2384 if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
2385 authTimer = GetTickCount();
2386 cardAUTHSC = receivedCmd[1] / 4; // received block num
2387 cardAUTHKEY = receivedCmd[0] - 0x60;
2388 crypto1_destroy(pcs);//Added by martin
2389 crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2390
2391 if (!encrypted_data) { // first authentication
2392 if (MF_DBGLEVEL >= 2) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2393
2394 crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
2395 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2396 } else { // nested authentication
2397 if (MF_DBGLEVEL >= 2) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2398 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2399 num_to_bytes(ans, 4, rAUTH_AT);
2400 }
2401 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2402 //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
2403 cardSTATE = MFEMUL_AUTH1;
2404 break;
2405 }
2406
2407 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2408 // BUT... ACK --> NACK
2409 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2410 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2411 break;
2412 }
2413
2414 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2415 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2416 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2417 break;
2418 }
2419
2420 if(len != 4) {
2421 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2422 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2423 break;
2424 }
2425
2426 if(receivedCmd[0] == 0x30 // read block
2427 || receivedCmd[0] == 0xA0 // write block
2428 || receivedCmd[0] == 0xC0
2429 || receivedCmd[0] == 0xC1
2430 || receivedCmd[0] == 0xC2 // inc dec restore
2431 || receivedCmd[0] == 0xB0) { // transfer
2432 if (receivedCmd[1] >= 16 * 4) {
2433 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2434 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]);
2435 break;
2436 }
2437
2438 if (receivedCmd[1] / 4 != cardAUTHSC) {
2439 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2440 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);
2441 break;
2442 }
2443 }
2444 // read block
2445 if (receivedCmd[0] == 0x30) {
2446 if (MF_DBGLEVEL >= 2) {
2447 Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
2448 }
2449 emlGetMem(response, receivedCmd[1], 1);
2450 AppendCrc14443a(response, 16);
2451 mf_crypto1_encrypt(pcs, response, 18, &par);
2452 EmSendCmdPar(response, 18, par);
2453 numReads++;
2454 if(exitAfterNReads > 0 && numReads == exitAfterNReads) {
2455 Dbprintf("%d reads done, exiting", numReads);
2456 finished = true;
2457 }
2458 break;
2459 }
2460 // write block
2461 if (receivedCmd[0] == 0xA0) {
2462 if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
2463 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2464 cardSTATE = MFEMUL_WRITEBL2;
2465 cardWRBL = receivedCmd[1];
2466 break;
2467 }
2468 // increment, decrement, restore
2469 if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
2470 if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2471 if (emlCheckValBl(receivedCmd[1])) {
2472 if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2473 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2474 break;
2475 }
2476 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2477 if (receivedCmd[0] == 0xC1)
2478 cardSTATE = MFEMUL_INTREG_INC;
2479 if (receivedCmd[0] == 0xC0)
2480 cardSTATE = MFEMUL_INTREG_DEC;
2481 if (receivedCmd[0] == 0xC2)
2482 cardSTATE = MFEMUL_INTREG_REST;
2483 cardWRBL = receivedCmd[1];
2484 break;
2485 }
2486 // transfer
2487 if (receivedCmd[0] == 0xB0) {
2488 if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2489 if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2490 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2491 else
2492 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2493 break;
2494 }
2495 // halt
2496 if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
2497 LED_B_OFF();
2498 LED_C_OFF();
2499 cardSTATE = MFEMUL_HALTED;
2500 if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer);
2501 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2502 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2503 break;
2504 }
2505 // RATS
2506 if (receivedCmd[0] == 0xe0) {//RATS
2507 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2508 break;
2509 }
2510 // command not allowed
2511 if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking");
2512 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2513 break;
2514 }
2515 case MFEMUL_WRITEBL2:{
2516 if (len == 18){
2517 mf_crypto1_decrypt(pcs, receivedCmd, len);
2518 emlSetMem(receivedCmd, cardWRBL, 1);
2519 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2520 cardSTATE = MFEMUL_WORK;
2521 } else {
2522 cardSTATE_TO_IDLE();
2523 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2524 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2525 }
2526 break;
2527 }
2528
2529 case MFEMUL_INTREG_INC:{
2530 mf_crypto1_decrypt(pcs, receivedCmd, len);
2531 memcpy(&ans, receivedCmd, 4);
2532 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2533 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2534 cardSTATE_TO_IDLE();
2535 break;
2536 }
2537 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2538 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2539 cardINTREG = cardINTREG + ans;
2540 cardSTATE = MFEMUL_WORK;
2541 break;
2542 }
2543 case MFEMUL_INTREG_DEC:{
2544 mf_crypto1_decrypt(pcs, receivedCmd, len);
2545 memcpy(&ans, receivedCmd, 4);
2546 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2547 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2548 cardSTATE_TO_IDLE();
2549 break;
2550 }
2551 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2552 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2553 cardINTREG = cardINTREG - ans;
2554 cardSTATE = MFEMUL_WORK;
2555 break;
2556 }
2557 case MFEMUL_INTREG_REST:{
2558 mf_crypto1_decrypt(pcs, receivedCmd, len);
2559 memcpy(&ans, receivedCmd, 4);
2560 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2561 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2562 cardSTATE_TO_IDLE();
2563 break;
2564 }
2565 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2566 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2567 cardSTATE = MFEMUL_WORK;
2568 break;
2569 }
2570 }
2571 }
2572
2573 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2574 LEDsoff();
2575
2576 if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
2577 {
2578 //May just aswell send the collected ar_nr in the response aswell
2579 cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_responses,ar_nr_collected*4*4);
2580 }
2581
2582 if(flags & FLAG_NR_AR_ATTACK)
2583 {
2584 if(ar_nr_collected > 1) {
2585 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
2586 Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
2587 ar_nr_responses[0], // UID
2588 ar_nr_responses[1], //NT
2589 ar_nr_responses[2], //AR1
2590 ar_nr_responses[3], //NR1
2591 ar_nr_responses[6], //AR2
2592 ar_nr_responses[7] //NR2
2593 );
2594 } else {
2595 Dbprintf("Failed to obtain two AR/NR pairs!");
2596 if(ar_nr_collected >0) {
2597 Dbprintf("Only got these: UID=%08x, nonce=%08x, AR1=%08x, NR1=%08x",
2598 ar_nr_responses[0], // UID
2599 ar_nr_responses[1], //NT
2600 ar_nr_responses[2], //AR1
2601 ar_nr_responses[3] //NR1
2602 );
2603 }
2604 }
2605 }
2606 if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, traceLen);
2607 }
2608
2609
2610
2611 //-----------------------------------------------------------------------------
2612 // MIFARE sniffer.
2613 //
2614 //-----------------------------------------------------------------------------
2615 void RAMFUNC SniffMifare(uint8_t param) {
2616 // param:
2617 // bit 0 - trigger from first card answer
2618 // bit 1 - trigger from first reader 7-bit request
2619
2620 // C(red) A(yellow) B(green)
2621 LEDsoff();
2622 // init trace buffer
2623 iso14a_clear_trace();
2624
2625 // The command (reader -> tag) that we're receiving.
2626 // The length of a received command will in most cases be no more than 18 bytes.
2627 // So 32 should be enough!
2628 uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
2629 // The response (tag -> reader) that we're receiving.
2630 uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
2631
2632 // As we receive stuff, we copy it from receivedCmd or receivedResponse
2633 // into trace, along with its length and other annotations.
2634 //uint8_t *trace = (uint8_t *)BigBuf;
2635
2636 // The DMA buffer, used to stream samples from the FPGA
2637 uint8_t *dmaBuf = ((uint8_t *)BigBuf) + DMA_BUFFER_OFFSET;
2638 uint8_t *data = dmaBuf;
2639 uint8_t previous_data = 0;
2640 int maxDataLen = 0;
2641 int dataLen = 0;
2642 bool ReaderIsActive = FALSE;
2643 bool TagIsActive = FALSE;
2644
2645 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
2646
2647 // Set up the demodulator for tag -> reader responses.
2648 Demod.output = receivedResponse;
2649
2650 // Set up the demodulator for the reader -> tag commands
2651 Uart.output = receivedCmd;
2652
2653 // Setup for the DMA.
2654 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2655
2656 LED_D_OFF();
2657
2658 // init sniffer
2659 MfSniffInit();
2660
2661 // And now we loop, receiving samples.
2662 for(uint32_t sniffCounter = 0; TRUE; ) {
2663
2664 if(BUTTON_PRESS()) {
2665 DbpString("cancelled by button");
2666 break;
2667 }
2668
2669 LED_A_ON();
2670 WDT_HIT();
2671
2672 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
2673 // check if a transaction is completed (timeout after 2000ms).
2674 // if yes, stop the DMA transfer and send what we have so far to the client
2675 if (MfSniffSend(2000)) {
2676 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
2677 sniffCounter = 0;
2678 data = dmaBuf;
2679 maxDataLen = 0;
2680 ReaderIsActive = FALSE;
2681 TagIsActive = FALSE;
2682 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2683 }
2684 }
2685
2686 int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
2687 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
2688 if (readBufDataP <= dmaBufDataP){ // we are processing the same block of data which is currently being transferred
2689 dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
2690 } else {
2691 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
2692 }
2693 // test for length of buffer
2694 if(dataLen > maxDataLen) { // we are more behind than ever...
2695 maxDataLen = dataLen;
2696 if(dataLen > 400) {
2697 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
2698 break;
2699 }
2700 }
2701 if(dataLen < 1) continue;
2702
2703 // primary buffer was stopped ( <-- we lost data!
2704 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
2705 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
2706 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
2707 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
2708 }
2709 // secondary buffer sets as primary, secondary buffer was stopped
2710 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
2711 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
2712 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
2713 }
2714
2715 LED_A_OFF();
2716
2717 if (sniffCounter & 0x01) {
2718
2719 if(!TagIsActive) { // no need to try decoding tag data if the reader is sending
2720 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
2721 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
2722 LED_C_INV();
2723 if (MfSniffLogic(receivedCmd, Uart.len, Uart.parityBits, Uart.bitCount, TRUE)) break;
2724
2725 /* And ready to receive another command. */
2726 UartReset();
2727
2728 /* And also reset the demod code */
2729 DemodReset();
2730 }
2731 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
2732 }
2733
2734 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending
2735 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
2736 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
2737 LED_C_INV();
2738
2739 if (MfSniffLogic(receivedResponse, Demod.len, Demod.parityBits, Demod.bitCount, FALSE)) break;
2740
2741 // And ready to receive another response.
2742 DemodReset();
2743 }
2744 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
2745 }
2746 }
2747
2748 previous_data = *data;
2749 sniffCounter++;
2750 data++;
2751 if(data == dmaBuf + DMA_BUFFER_SIZE) {
2752 data = dmaBuf;
2753 }
2754
2755 } // main cycle
2756
2757 DbpString("COMMAND FINISHED");
2758
2759 FpgaDisableSscDma();
2760 MfSniffEnd();
2761
2762 Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
2763 LEDsoff();
2764 }
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