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Merge branch 'master' of https://github.com/Proxmark/proxmark3
[proxmark3-svn] / armsrc / iso14443a.c
1 //-----------------------------------------------------------------------------
2 // Merlok - June 2011, 2012
3 // Gerhard de Koning Gans - May 2008
4 // Hagen Fritsch - June 2010
5 //
6 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
7 // at your option, any later version. See the LICENSE.txt file for the text of
8 // the license.
9 //-----------------------------------------------------------------------------
10 // Routines to support ISO 14443 type A.
11 //-----------------------------------------------------------------------------
12
13 #include "../include/proxmark3.h"
14 #include "apps.h"
15 #include "util.h"
16 #include "string.h"
17 #include "../common/cmd.h"
18 #include "../common/iso14443crc.h"
19 #include "iso14443a.h"
20 #include "crapto1.h"
21 #include "mifareutil.h"
22
23 static uint32_t iso14a_timeout;
24 uint8_t *trace = (uint8_t *) BigBuf+TRACE_OFFSET;
25 int rsamples = 0;
26 int traceLen = 0;
27 int tracing = TRUE;
28 uint8_t trigger = 0;
29 // the block number for the ISO14443-4 PCB
30 static uint8_t iso14_pcb_blocknum = 0;
31
32 //
33 // ISO14443 timing:
34 //
35 // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
36 #define REQUEST_GUARD_TIME (7000/16 + 1)
37 // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
38 #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
39 // bool LastCommandWasRequest = FALSE;
40
41 //
42 // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
43 //
44 // When the PM acts as reader and is receiving tag data, it takes
45 // 3 ticks delay in the AD converter
46 // 16 ticks until the modulation detector completes and sets curbit
47 // 8 ticks until bit_to_arm is assigned from curbit
48 // 8*16 ticks for the transfer from FPGA to ARM
49 // 4*16 ticks until we measure the time
50 // - 8*16 ticks because we measure the time of the previous transfer
51 #define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
52
53 // When the PM acts as a reader and is sending, it takes
54 // 4*16 ticks until we can write data to the sending hold register
55 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
56 // 8 ticks until the first transfer starts
57 // 8 ticks later the FPGA samples the data
58 // 1 tick to assign mod_sig_coil
59 #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
60
61 // When the PM acts as tag and is receiving it takes
62 // 2 ticks delay in the RF part (for the first falling edge),
63 // 3 ticks for the A/D conversion,
64 // 8 ticks on average until the start of the SSC transfer,
65 // 8 ticks until the SSC samples the first data
66 // 7*16 ticks to complete the transfer from FPGA to ARM
67 // 8 ticks until the next ssp_clk rising edge
68 // 4*16 ticks until we measure the time
69 // - 8*16 ticks because we measure the time of the previous transfer
70 #define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
71
72 // The FPGA will report its internal sending delay in
73 uint16_t FpgaSendQueueDelay;
74 // the 5 first bits are the number of bits buffered in mod_sig_buf
75 // the last three bits are the remaining ticks/2 after the mod_sig_buf shift
76 #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
77
78 // When the PM acts as tag and is sending, it takes
79 // 4*16 ticks until we can write data to the sending hold register
80 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
81 // 8 ticks until the first transfer starts
82 // 8 ticks later the FPGA samples the data
83 // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
84 // + 1 tick to assign mod_sig_coil
85 #define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
86
87 // When the PM acts as sniffer and is receiving tag data, it takes
88 // 3 ticks A/D conversion
89 // 14 ticks to complete the modulation detection
90 // 8 ticks (on average) until the result is stored in to_arm
91 // + the delays in transferring data - which is the same for
92 // sniffing reader and tag data and therefore not relevant
93 #define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
94
95 // When the PM acts as sniffer and is receiving reader data, it takes
96 // 2 ticks delay in analogue RF receiver (for the falling edge of the
97 // start bit, which marks the start of the communication)
98 // 3 ticks A/D conversion
99 // 8 ticks on average until the data is stored in to_arm.
100 // + the delays in transferring data - which is the same for
101 // sniffing reader and tag data and therefore not relevant
102 #define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
103
104 //variables used for timing purposes:
105 //these are in ssp_clk cycles:
106 uint32_t NextTransferTime;
107 uint32_t LastTimeProxToAirStart;
108 uint32_t LastProxToAirDuration;
109
110
111
112 // CARD TO READER - manchester
113 // Sequence D: 11110000 modulation with subcarrier during first half
114 // Sequence E: 00001111 modulation with subcarrier during second half
115 // Sequence F: 00000000 no modulation with subcarrier
116 // READER TO CARD - miller
117 // Sequence X: 00001100 drop after half a period
118 // Sequence Y: 00000000 no drop
119 // Sequence Z: 11000000 drop at start
120 #define SEC_D 0xf0
121 #define SEC_E 0x0f
122 #define SEC_F 0x00
123 #define SEC_X 0x0c
124 #define SEC_Y 0x00
125 #define SEC_Z 0xc0
126
127 const uint8_t OddByteParity[256] = {
128 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
129 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
130 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
131 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
132 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
133 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
134 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
135 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
136 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
137 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
138 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
139 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
140 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
141 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
142 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
143 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1
144 };
145
146
147 void iso14a_set_trigger(bool enable) {
148 trigger = enable;
149 }
150
151 void iso14a_clear_trace() {
152 memset(trace, 0x44, TRACE_SIZE);
153 traceLen = 0;
154 }
155
156 void iso14a_set_tracing(bool enable) {
157 tracing = enable;
158 }
159
160 void iso14a_set_timeout(uint32_t timeout) {
161 iso14a_timeout = timeout;
162 }
163
164 //-----------------------------------------------------------------------------
165 // Generate the parity value for a byte sequence
166 //
167 //-----------------------------------------------------------------------------
168 byte_t oddparity (const byte_t bt)
169 {
170 return OddByteParity[bt];
171 }
172
173 uint32_t GetParity(const uint8_t * pbtCmd, int iLen)
174 {
175 int i;
176 uint32_t dwPar = 0;
177
178 // Generate the parity bits
179 for (i = 0; i < iLen; i++) {
180 // and save them to a 32Bit word
181 dwPar |= ((OddByteParity[pbtCmd[i]]) << i);
182 }
183 return dwPar;
184 }
185
186 void AppendCrc14443a(uint8_t* data, int len)
187 {
188 ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
189 }
190
191 // The function LogTrace() is also used by the iClass implementation in iClass.c
192 bool RAMFUNC LogTrace(const uint8_t * btBytes, uint8_t iLen, uint32_t timestamp, uint32_t dwParity, bool readerToTag)
193 {
194 if (!tracing) return FALSE;
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
207 if (!readerToTag) {
208 trace[traceLen - 1] |= 0x80;
209 }
210 trace[traceLen++] = ((dwParity >> 0) & 0xff);
211 trace[traceLen++] = ((dwParity >> 8) & 0xff);
212 trace[traceLen++] = ((dwParity >> 16) & 0xff);
213 trace[traceLen++] = ((dwParity >> 24) & 0xff);
214 trace[traceLen++] = iLen;
215 if (btBytes != NULL && iLen != 0) {
216 memcpy(trace + traceLen, btBytes, iLen);
217 }
218 traceLen += iLen;
219 return TRUE;
220 }
221
222 //=============================================================================
223 // ISO 14443 Type A - Miller decoder
224 //=============================================================================
225 // Basics:
226 // This decoder is used when the PM3 acts as a tag.
227 // The reader will generate "pauses" by temporarily switching of the field.
228 // At the PM3 antenna we will therefore measure a modulated antenna voltage.
229 // The FPGA does a comparison with a threshold and would deliver e.g.:
230 // ........ 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 .......
231 // The Miller decoder needs to identify the following sequences:
232 // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0")
233 // 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information")
234 // 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1")
235 // Note 1: the bitstream may start at any time. We therefore need to sync.
236 // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
237 //-----------------------------------------------------------------------------
238 static tUart Uart;
239
240 // Lookup-Table to decide if 4 raw bits are a modulation.
241 // We accept two or three consecutive "0" in any position with the rest "1"
242 const bool Mod_Miller_LUT[] = {
243 TRUE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, FALSE,
244 TRUE, TRUE, FALSE, FALSE, TRUE, FALSE, FALSE, FALSE
245 };
246 #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x00F0) >> 4])
247 #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x000F)])
248
249 void UartReset()
250 {
251 Uart.state = STATE_UNSYNCD;
252 Uart.bitCount = 0;
253 Uart.len = 0; // number of decoded data bytes
254 Uart.shiftReg = 0; // shiftreg to hold decoded data bits
255 Uart.parityBits = 0; //
256 Uart.twoBits = 0x0000; // buffer for 2 Bits
257 Uart.highCnt = 0;
258 Uart.startTime = 0;
259 Uart.endTime = 0;
260 }
261
262
263 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
264 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
265 {
266
267 Uart.twoBits = (Uart.twoBits << 8) | bit;
268
269 if (Uart.state == STATE_UNSYNCD) { // not yet synced
270 if (Uart.highCnt < 7) { // wait for a stable unmodulated signal
271 if (Uart.twoBits == 0xffff) {
272 Uart.highCnt++;
273 } else {
274 Uart.highCnt = 0;
275 }
276 } else {
277 Uart.syncBit = 0xFFFF; // not set
278 // look for 00xx1111 (the start bit)
279 if ((Uart.twoBits & 0x6780) == 0x0780) Uart.syncBit = 7;
280 else if ((Uart.twoBits & 0x33C0) == 0x03C0) Uart.syncBit = 6;
281 else if ((Uart.twoBits & 0x19E0) == 0x01E0) Uart.syncBit = 5;
282 else if ((Uart.twoBits & 0x0CF0) == 0x00F0) Uart.syncBit = 4;
283 else if ((Uart.twoBits & 0x0678) == 0x0078) Uart.syncBit = 3;
284 else if ((Uart.twoBits & 0x033C) == 0x003C) Uart.syncBit = 2;
285 else if ((Uart.twoBits & 0x019E) == 0x001E) Uart.syncBit = 1;
286 else if ((Uart.twoBits & 0x00CF) == 0x000F) Uart.syncBit = 0;
287 if (Uart.syncBit != 0xFFFF) {
288 Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
289 Uart.startTime -= Uart.syncBit;
290 Uart.endTime = Uart.startTime;
291 Uart.state = STATE_START_OF_COMMUNICATION;
292 }
293 }
294
295 } else {
296
297 if (IsMillerModulationNibble1(Uart.twoBits >> Uart.syncBit)) {
298 if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation in both halves - error
299 UartReset();
300 Uart.highCnt = 6;
301 } else { // Modulation in first half = Sequence Z = logic "0"
302 if (Uart.state == STATE_MILLER_X) { // error - must not follow after X
303 UartReset();
304 Uart.highCnt = 6;
305 } else {
306 Uart.bitCount++;
307 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
308 Uart.state = STATE_MILLER_Z;
309 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
310 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
311 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
312 Uart.parityBits <<= 1; // make room for the parity bit
313 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
314 Uart.bitCount = 0;
315 Uart.shiftReg = 0;
316 }
317 }
318 }
319 } else {
320 if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1"
321 Uart.bitCount++;
322 Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg
323 Uart.state = STATE_MILLER_X;
324 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
325 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
326 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
327 Uart.parityBits <<= 1; // make room for the new parity bit
328 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
329 Uart.bitCount = 0;
330 Uart.shiftReg = 0;
331 }
332 } else { // no modulation in both halves - Sequence Y
333 if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication
334 Uart.state = STATE_UNSYNCD;
335 if(Uart.len == 0 && Uart.bitCount > 0) { // if we decoded some bits
336 Uart.shiftReg >>= (9 - Uart.bitCount); // add them to the output
337 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
338 Uart.parityBits <<= 1; // no parity bit - add "0"
339 Uart.bitCount--; // last "0" was part of the EOC sequence
340 }
341 return TRUE;
342 }
343 if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC
344 UartReset();
345 Uart.highCnt = 6;
346 } else { // a logic "0"
347 Uart.bitCount++;
348 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
349 Uart.state = STATE_MILLER_Y;
350 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
351 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
352 Uart.parityBits <<= 1; // make room for the parity bit
353 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
354 Uart.bitCount = 0;
355 Uart.shiftReg = 0;
356 }
357 }
358 }
359 }
360
361 }
362
363 return FALSE; // not finished yet, need more data
364 }
365
366
367
368 //=============================================================================
369 // ISO 14443 Type A - Manchester decoder
370 //=============================================================================
371 // Basics:
372 // This decoder is used when the PM3 acts as a reader.
373 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
374 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
375 // ........ 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 .......
376 // The Manchester decoder needs to identify the following sequences:
377 // 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication")
378 // 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0
379 // 8 ticks unmodulated: Sequence F = end of communication
380 // 8 ticks modulated: A collision. Save the collision position and treat as Sequence D
381 // Note 1: the bitstream may start at any time. We therefore need to sync.
382 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
383 static tDemod Demod;
384
385 // Lookup-Table to decide if 4 raw bits are a modulation.
386 // We accept three or four "1" in any position
387 const bool Mod_Manchester_LUT[] = {
388 FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
389 FALSE, FALSE, FALSE, TRUE, FALSE, TRUE, TRUE, TRUE
390 };
391
392 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
393 #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
394
395
396 void DemodReset()
397 {
398 Demod.state = DEMOD_UNSYNCD;
399 Demod.len = 0; // number of decoded data bytes
400 Demod.shiftReg = 0; // shiftreg to hold decoded data bits
401 Demod.parityBits = 0; //
402 Demod.collisionPos = 0; // Position of collision bit
403 Demod.twoBits = 0xffff; // buffer for 2 Bits
404 Demod.highCnt = 0;
405 Demod.startTime = 0;
406 Demod.endTime = 0;
407 }
408
409 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
410 static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
411 {
412
413 Demod.twoBits = (Demod.twoBits << 8) | bit;
414
415 if (Demod.state == DEMOD_UNSYNCD) {
416
417 if (Demod.highCnt < 2) { // wait for a stable unmodulated signal
418 if (Demod.twoBits == 0x0000) {
419 Demod.highCnt++;
420 } else {
421 Demod.highCnt = 0;
422 }
423 } else {
424 Demod.syncBit = 0xFFFF; // not set
425 if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
426 else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
427 else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
428 else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
429 else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
430 else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
431 else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
432 else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
433 if (Demod.syncBit != 0xFFFF) {
434 Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
435 Demod.startTime -= Demod.syncBit;
436 Demod.bitCount = offset; // number of decoded data bits
437 Demod.state = DEMOD_MANCHESTER_DATA;
438 }
439 }
440
441 } else {
442
443 if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half
444 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... and in second half = collision
445 if (!Demod.collisionPos) {
446 Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
447 }
448 } // modulation in first half only - Sequence D = 1
449 Demod.bitCount++;
450 Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg
451 if(Demod.bitCount == 9) { // if we decoded a full byte (including parity)
452 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
453 Demod.parityBits <<= 1; // make room for the parity bit
454 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
455 Demod.bitCount = 0;
456 Demod.shiftReg = 0;
457 }
458 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
459 } else { // no modulation in first half
460 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // and modulation in second half = Sequence E = 0
461 Demod.bitCount++;
462 Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg
463 if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity)
464 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
465 Demod.parityBits <<= 1; // make room for the new parity bit
466 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
467 Demod.bitCount = 0;
468 Demod.shiftReg = 0;
469 }
470 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
471 } else { // no modulation in both halves - End of communication
472 if (Demod.len > 0 || Demod.bitCount > 0) { // received something
473 if(Demod.bitCount > 0) { // if we decoded bits
474 Demod.shiftReg >>= (9 - Demod.bitCount); // add the remaining decoded bits to the output
475 Demod.output[Demod.len++] = Demod.shiftReg & 0xff;
476 // No parity bit, so just shift a 0
477 Demod.parityBits <<= 1;
478 }
479 return TRUE; // we are finished with decoding the raw data sequence
480 } else { // nothing received. Start over
481 DemodReset();
482 }
483 }
484 }
485
486 }
487
488 return FALSE; // not finished yet, need more data
489 }
490
491 //=============================================================================
492 // Finally, a `sniffer' for ISO 14443 Type A
493 // Both sides of communication!
494 //=============================================================================
495
496 //-----------------------------------------------------------------------------
497 // Record the sequence of commands sent by the reader to the tag, with
498 // triggering so that we start recording at the point that the tag is moved
499 // near the reader.
500 //-----------------------------------------------------------------------------
501 void RAMFUNC SnoopIso14443a(uint8_t param) {
502 // param:
503 // bit 0 - trigger from first card answer
504 // bit 1 - trigger from first reader 7-bit request
505
506 LEDsoff();
507 // init trace buffer
508 iso14a_clear_trace();
509 iso14a_set_tracing(TRUE);
510
511 // We won't start recording the frames that we acquire until we trigger;
512 // a good trigger condition to get started is probably when we see a
513 // response from the tag.
514 // triggered == FALSE -- to wait first for card
515 bool triggered = !(param & 0x03);
516
517 // The command (reader -> tag) that we're receiving.
518 // The length of a received command will in most cases be no more than 18 bytes.
519 // So 32 should be enough!
520 uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
521 // The response (tag -> reader) that we're receiving.
522 uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
523
524 // As we receive stuff, we copy it from receivedCmd or receivedResponse
525 // into trace, along with its length and other annotations.
526 //uint8_t *trace = (uint8_t *)BigBuf;
527
528 // The DMA buffer, used to stream samples from the FPGA
529 uint8_t *dmaBuf = ((uint8_t *)BigBuf) + DMA_BUFFER_OFFSET;
530 uint8_t *data = dmaBuf;
531 uint8_t previous_data = 0;
532 int maxDataLen = 0;
533 int dataLen = 0;
534 bool TagIsActive = FALSE;
535 bool ReaderIsActive = FALSE;
536
537 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
538
539 // Set up the demodulator for tag -> reader responses.
540 Demod.output = receivedResponse;
541
542 // Set up the demodulator for the reader -> tag commands
543 Uart.output = receivedCmd;
544
545 // Setup and start DMA.
546 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
547
548 // And now we loop, receiving samples.
549 for(uint32_t rsamples = 0; TRUE; ) {
550
551 if(BUTTON_PRESS()) {
552 DbpString("cancelled by button");
553 break;
554 }
555
556 LED_A_ON();
557 WDT_HIT();
558
559 int register readBufDataP = data - dmaBuf;
560 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
561 if (readBufDataP <= dmaBufDataP){
562 dataLen = dmaBufDataP - readBufDataP;
563 } else {
564 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
565 }
566 // test for length of buffer
567 if(dataLen > maxDataLen) {
568 maxDataLen = dataLen;
569 if(dataLen > 400) {
570 Dbprintf("blew circular buffer! dataLen=%d", dataLen);
571 break;
572 }
573 }
574 if(dataLen < 1) continue;
575
576 // primary buffer was stopped( <-- we lost data!
577 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
578 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
579 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
580 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
581 }
582 // secondary buffer sets as primary, secondary buffer was stopped
583 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
584 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
585 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
586 }
587
588 LED_A_OFF();
589
590 if (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder
591
592 if(!TagIsActive) { // no need to try decoding reader data if the tag is sending
593 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
594 if (MillerDecoding(readerdata, (rsamples-1)*4)) {
595 LED_C_ON();
596
597 // check - if there is a short 7bit request from reader
598 if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
599
600 if(triggered) {
601 if (!LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, Uart.parityBits, TRUE)) break;
602 if (!LogTrace(NULL, 0, Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, 0, TRUE)) break;
603 }
604 /* And ready to receive another command. */
605 UartReset();
606 /* And also reset the demod code, which might have been */
607 /* false-triggered by the commands from the reader. */
608 DemodReset();
609 LED_B_OFF();
610 }
611 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
612 }
613
614 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time
615 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
616 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
617 LED_B_ON();
618
619 if (!LogTrace(receivedResponse, Demod.len, Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, Demod.parityBits, FALSE)) break;
620 if (!LogTrace(NULL, 0, Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, 0, FALSE)) break;
621
622 if ((!triggered) && (param & 0x01)) triggered = TRUE;
623
624 // And ready to receive another response.
625 DemodReset();
626 LED_C_OFF();
627 }
628 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
629 }
630 }
631
632 previous_data = *data;
633 rsamples++;
634 data++;
635 if(data == dmaBuf + DMA_BUFFER_SIZE) {
636 data = dmaBuf;
637 }
638 } // main cycle
639
640 DbpString("COMMAND FINISHED");
641
642 FpgaDisableSscDma();
643 Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
644 Dbprintf("traceLen=%d, Uart.output[0]=%08x", traceLen, (uint32_t)Uart.output[0]);
645 LEDsoff();
646 }
647
648 //-----------------------------------------------------------------------------
649 // Prepare tag messages
650 //-----------------------------------------------------------------------------
651 static void CodeIso14443aAsTagPar(const uint8_t *cmd, int len, uint32_t dwParity)
652 {
653 int i;
654
655 ToSendReset();
656
657 // Correction bit, might be removed when not needed
658 ToSendStuffBit(0);
659 ToSendStuffBit(0);
660 ToSendStuffBit(0);
661 ToSendStuffBit(0);
662 ToSendStuffBit(1); // 1
663 ToSendStuffBit(0);
664 ToSendStuffBit(0);
665 ToSendStuffBit(0);
666
667 // Send startbit
668 ToSend[++ToSendMax] = SEC_D;
669 LastProxToAirDuration = 8 * ToSendMax - 4;
670
671 for(i = 0; i < len; i++) {
672 int j;
673 uint8_t b = cmd[i];
674
675 // Data bits
676 for(j = 0; j < 8; j++) {
677 if(b & 1) {
678 ToSend[++ToSendMax] = SEC_D;
679 } else {
680 ToSend[++ToSendMax] = SEC_E;
681 }
682 b >>= 1;
683 }
684
685 // Get the parity bit
686 if ((dwParity >> i) & 0x01) {
687 ToSend[++ToSendMax] = SEC_D;
688 LastProxToAirDuration = 8 * ToSendMax - 4;
689 } else {
690 ToSend[++ToSendMax] = SEC_E;
691 LastProxToAirDuration = 8 * ToSendMax;
692 }
693 }
694
695 // Send stopbit
696 ToSend[++ToSendMax] = SEC_F;
697
698 // Convert from last byte pos to length
699 ToSendMax++;
700 }
701
702 static void CodeIso14443aAsTag(const uint8_t *cmd, int len){
703 CodeIso14443aAsTagPar(cmd, len, GetParity(cmd, len));
704 }
705
706
707 static void Code4bitAnswerAsTag(uint8_t cmd)
708 {
709 int i;
710
711 ToSendReset();
712
713 // Correction bit, might be removed when not needed
714 ToSendStuffBit(0);
715 ToSendStuffBit(0);
716 ToSendStuffBit(0);
717 ToSendStuffBit(0);
718 ToSendStuffBit(1); // 1
719 ToSendStuffBit(0);
720 ToSendStuffBit(0);
721 ToSendStuffBit(0);
722
723 // Send startbit
724 ToSend[++ToSendMax] = SEC_D;
725
726 uint8_t b = cmd;
727 for(i = 0; i < 4; i++) {
728 if(b & 1) {
729 ToSend[++ToSendMax] = SEC_D;
730 LastProxToAirDuration = 8 * ToSendMax - 4;
731 } else {
732 ToSend[++ToSendMax] = SEC_E;
733 LastProxToAirDuration = 8 * ToSendMax;
734 }
735 b >>= 1;
736 }
737
738 // Send stopbit
739 ToSend[++ToSendMax] = SEC_F;
740
741 // Convert from last byte pos to length
742 ToSendMax++;
743 }
744
745 //-----------------------------------------------------------------------------
746 // Wait for commands from reader
747 // Stop when button is pressed
748 // Or return TRUE when command is captured
749 //-----------------------------------------------------------------------------
750 static int GetIso14443aCommandFromReader(uint8_t *received, int *len, int maxLen)
751 {
752 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
753 // only, since we are receiving, not transmitting).
754 // Signal field is off with the appropriate LED
755 LED_D_OFF();
756 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
757
758 // Now run a `software UART' on the stream of incoming samples.
759 UartReset();
760 Uart.output = received;
761
762 // clear RXRDY:
763 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
764
765 for(;;) {
766 WDT_HIT();
767
768 if(BUTTON_PRESS()) return FALSE;
769
770 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
771 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
772 if(MillerDecoding(b, 0)) {
773 *len = Uart.len;
774 return TRUE;
775 }
776 }
777 }
778 }
779
780 static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, bool correctionNeeded);
781 int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
782 int EmSend4bit(uint8_t resp);
783 int EmSendCmdExPar(uint8_t *resp, int respLen, bool correctionNeeded, uint32_t par);
784 int EmSendCmdExPar(uint8_t *resp, int respLen, bool correctionNeeded, uint32_t par);
785 int EmSendCmdEx(uint8_t *resp, int respLen, bool correctionNeeded);
786 int EmSendCmd(uint8_t *resp, int respLen);
787 int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par);
788 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint32_t reader_Parity,
789 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint32_t tag_Parity);
790
791 static uint8_t* free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
792
793 typedef struct {
794 uint8_t* response;
795 size_t response_n;
796 uint8_t* modulation;
797 size_t modulation_n;
798 uint32_t ProxToAirDuration;
799 } tag_response_info_t;
800
801 void reset_free_buffer() {
802 free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
803 }
804
805 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
806 // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
807 // This will need the following byte array for a modulation sequence
808 // 144 data bits (18 * 8)
809 // 18 parity bits
810 // 2 Start and stop
811 // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA)
812 // 1 just for the case
813 // ----------- +
814 // 166 bytes, since every bit that needs to be send costs us a byte
815 //
816
817 // Prepare the tag modulation bits from the message
818 CodeIso14443aAsTag(response_info->response,response_info->response_n);
819
820 // Make sure we do not exceed the free buffer space
821 if (ToSendMax > max_buffer_size) {
822 Dbprintf("Out of memory, when modulating bits for tag answer:");
823 Dbhexdump(response_info->response_n,response_info->response,false);
824 return false;
825 }
826
827 // Copy the byte array, used for this modulation to the buffer position
828 memcpy(response_info->modulation,ToSend,ToSendMax);
829
830 // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
831 response_info->modulation_n = ToSendMax;
832 response_info->ProxToAirDuration = LastProxToAirDuration;
833
834 return true;
835 }
836
837 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
838 // Retrieve and store the current buffer index
839 response_info->modulation = free_buffer_pointer;
840
841 // Determine the maximum size we can use from our buffer
842 size_t max_buffer_size = (((uint8_t *)BigBuf)+FREE_BUFFER_OFFSET+FREE_BUFFER_SIZE)-free_buffer_pointer;
843
844 // Forward the prepare tag modulation function to the inner function
845 if (prepare_tag_modulation(response_info,max_buffer_size)) {
846 // Update the free buffer offset
847 free_buffer_pointer += ToSendMax;
848 return true;
849 } else {
850 return false;
851 }
852 }
853
854 //-----------------------------------------------------------------------------
855 // Main loop of simulated tag: receive commands from reader, decide what
856 // response to send, and send it.
857 //-----------------------------------------------------------------------------
858 void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
859 {
860 // Enable and clear the trace
861 iso14a_clear_trace();
862 iso14a_set_tracing(TRUE);
863
864 uint8_t sak;
865
866 // The first response contains the ATQA (note: bytes are transmitted in reverse order).
867 uint8_t response1[2];
868
869 switch (tagType) {
870 case 1: { // MIFARE Classic
871 // Says: I am Mifare 1k - original line
872 response1[0] = 0x04;
873 response1[1] = 0x00;
874 sak = 0x08;
875 } break;
876 case 2: { // MIFARE Ultralight
877 // Says: I am a stupid memory tag, no crypto
878 response1[0] = 0x04;
879 response1[1] = 0x00;
880 sak = 0x00;
881 } break;
882 case 3: { // MIFARE DESFire
883 // Says: I am a DESFire tag, ph33r me
884 response1[0] = 0x04;
885 response1[1] = 0x03;
886 sak = 0x20;
887 } break;
888 case 4: { // ISO/IEC 14443-4
889 // Says: I am a javacard (JCOP)
890 response1[0] = 0x04;
891 response1[1] = 0x00;
892 sak = 0x28;
893 } break;
894 default: {
895 Dbprintf("Error: unkown tagtype (%d)",tagType);
896 return;
897 } break;
898 }
899
900 // The second response contains the (mandatory) first 24 bits of the UID
901 uint8_t response2[5];
902
903 // Check if the uid uses the (optional) part
904 uint8_t response2a[5];
905 if (uid_2nd) {
906 response2[0] = 0x88;
907 num_to_bytes(uid_1st,3,response2+1);
908 num_to_bytes(uid_2nd,4,response2a);
909 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
910
911 // Configure the ATQA and SAK accordingly
912 response1[0] |= 0x40;
913 sak |= 0x04;
914 } else {
915 num_to_bytes(uid_1st,4,response2);
916 // Configure the ATQA and SAK accordingly
917 response1[0] &= 0xBF;
918 sak &= 0xFB;
919 }
920
921 // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
922 response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
923
924 // Prepare the mandatory SAK (for 4 and 7 byte UID)
925 uint8_t response3[3];
926 response3[0] = sak;
927 ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
928
929 // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
930 uint8_t response3a[3];
931 response3a[0] = sak & 0xFB;
932 ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
933
934 uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
935 uint8_t response6[] = { 0x04, 0x58, 0x00, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS
936 ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
937
938 #define TAG_RESPONSE_COUNT 7
939 tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
940 { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type
941 { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid
942 { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked
943 { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1
944 { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2
945 { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce)
946 { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS
947 };
948
949 // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
950 // Such a response is less time critical, so we can prepare them on the fly
951 #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
952 #define DYNAMIC_MODULATION_BUFFER_SIZE 512
953 uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
954 uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
955 tag_response_info_t dynamic_response_info = {
956 .response = dynamic_response_buffer,
957 .response_n = 0,
958 .modulation = dynamic_modulation_buffer,
959 .modulation_n = 0
960 };
961
962 // Reset the offset pointer of the free buffer
963 reset_free_buffer();
964
965 // Prepare the responses of the anticollision phase
966 // there will be not enough time to do this at the moment the reader sends it REQA
967 for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
968 prepare_allocated_tag_modulation(&responses[i]);
969 }
970
971 uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
972 int len = 0;
973
974 // To control where we are in the protocol
975 int order = 0;
976 int lastorder;
977
978 // Just to allow some checks
979 int happened = 0;
980 int happened2 = 0;
981 int cmdsRecvd = 0;
982
983 // We need to listen to the high-frequency, peak-detected path.
984 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
985
986 cmdsRecvd = 0;
987 tag_response_info_t* p_response;
988
989 LED_A_ON();
990 for(;;) {
991 // Clean receive command buffer
992
993 if(!GetIso14443aCommandFromReader(receivedCmd, &len, RECV_CMD_SIZE)) {
994 DbpString("Button press");
995 break;
996 }
997
998 p_response = NULL;
999
1000 // 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
1001 // Okay, look at the command now.
1002 lastorder = order;
1003 if(receivedCmd[0] == 0x26) { // Received a REQUEST
1004 p_response = &responses[0]; order = 1;
1005 } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
1006 p_response = &responses[0]; order = 6;
1007 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // Received request for UID (cascade 1)
1008 p_response = &responses[1]; order = 2;
1009 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2)
1010 p_response = &responses[2]; order = 20;
1011 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) { // Received a SELECT (cascade 1)
1012 p_response = &responses[3]; order = 3;
1013 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) { // Received a SELECT (cascade 2)
1014 p_response = &responses[4]; order = 30;
1015 } else if(receivedCmd[0] == 0x30) { // Received a (plain) READ
1016 EmSendCmdEx(data+(4*receivedCmd[0]),16,false);
1017 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1018 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1019 p_response = NULL;
1020 } else if(receivedCmd[0] == 0x50) { // Received a HALT
1021 // DbpString("Reader requested we HALT!:");
1022 if (tracing) {
1023 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
1024 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
1025 }
1026 p_response = NULL;
1027 } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) { // Received an authentication request
1028 p_response = &responses[5]; order = 7;
1029 } else if(receivedCmd[0] == 0xE0) { // Received a RATS request
1030 if (tagType == 1 || tagType == 2) { // RATS not supported
1031 EmSend4bit(CARD_NACK_NA);
1032 p_response = NULL;
1033 } else {
1034 p_response = &responses[6]; order = 70;
1035 }
1036 } else if (order == 7 && len == 8) { // Received authentication request
1037 if (tracing) {
1038 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
1039 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
1040 }
1041 uint32_t nr = bytes_to_num(receivedCmd,4);
1042 uint32_t ar = bytes_to_num(receivedCmd+4,4);
1043 Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar);
1044 } else {
1045 // Check for ISO 14443A-4 compliant commands, look at left nibble
1046 switch (receivedCmd[0]) {
1047
1048 case 0x0B:
1049 case 0x0A: { // IBlock (command)
1050 dynamic_response_info.response[0] = receivedCmd[0];
1051 dynamic_response_info.response[1] = 0x00;
1052 dynamic_response_info.response[2] = 0x90;
1053 dynamic_response_info.response[3] = 0x00;
1054 dynamic_response_info.response_n = 4;
1055 } break;
1056
1057 case 0x1A:
1058 case 0x1B: { // Chaining command
1059 dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1060 dynamic_response_info.response_n = 2;
1061 } break;
1062
1063 case 0xaa:
1064 case 0xbb: {
1065 dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1066 dynamic_response_info.response_n = 2;
1067 } break;
1068
1069 case 0xBA: { //
1070 memcpy(dynamic_response_info.response,"\xAB\x00",2);
1071 dynamic_response_info.response_n = 2;
1072 } break;
1073
1074 case 0xCA:
1075 case 0xC2: { // Readers sends deselect command
1076 memcpy(dynamic_response_info.response,"\xCA\x00",2);
1077 dynamic_response_info.response_n = 2;
1078 } break;
1079
1080 default: {
1081 // Never seen this command before
1082 if (tracing) {
1083 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
1084 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
1085 }
1086 Dbprintf("Received unknown command (len=%d):",len);
1087 Dbhexdump(len,receivedCmd,false);
1088 // Do not respond
1089 dynamic_response_info.response_n = 0;
1090 } break;
1091 }
1092
1093 if (dynamic_response_info.response_n > 0) {
1094 // Copy the CID from the reader query
1095 dynamic_response_info.response[1] = receivedCmd[1];
1096
1097 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1098 AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
1099 dynamic_response_info.response_n += 2;
1100
1101 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1102 Dbprintf("Error preparing tag response");
1103 if (tracing) {
1104 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
1105 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
1106 }
1107 break;
1108 }
1109 p_response = &dynamic_response_info;
1110 }
1111 }
1112
1113 // Count number of wakeups received after a halt
1114 if(order == 6 && lastorder == 5) { happened++; }
1115
1116 // Count number of other messages after a halt
1117 if(order != 6 && lastorder == 5) { happened2++; }
1118
1119 if(cmdsRecvd > 999) {
1120 DbpString("1000 commands later...");
1121 break;
1122 }
1123 cmdsRecvd++;
1124
1125 if (p_response != NULL) {
1126 EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1127 // do the tracing for the previous reader request and this tag answer:
1128 EmLogTrace(Uart.output,
1129 Uart.len,
1130 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1131 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1132 Uart.parityBits,
1133 p_response->response,
1134 p_response->response_n,
1135 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1136 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1137 SwapBits(GetParity(p_response->response, p_response->response_n), p_response->response_n));
1138 }
1139
1140 if (!tracing) {
1141 Dbprintf("Trace Full. Simulation stopped.");
1142 break;
1143 }
1144 }
1145
1146 Dbprintf("%x %x %x", happened, happened2, cmdsRecvd);
1147 LED_A_OFF();
1148 }
1149
1150
1151 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1152 // of bits specified in the delay parameter.
1153 void PrepareDelayedTransfer(uint16_t delay)
1154 {
1155 uint8_t bitmask = 0;
1156 uint8_t bits_to_shift = 0;
1157 uint8_t bits_shifted = 0;
1158
1159 delay &= 0x07;
1160 if (delay) {
1161 for (uint16_t i = 0; i < delay; i++) {
1162 bitmask |= (0x01 << i);
1163 }
1164 ToSend[ToSendMax++] = 0x00;
1165 for (uint16_t i = 0; i < ToSendMax; i++) {
1166 bits_to_shift = ToSend[i] & bitmask;
1167 ToSend[i] = ToSend[i] >> delay;
1168 ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1169 bits_shifted = bits_to_shift;
1170 }
1171 }
1172 }
1173
1174
1175 //-------------------------------------------------------------------------------------
1176 // Transmit the command (to the tag) that was placed in ToSend[].
1177 // Parameter timing:
1178 // if NULL: transfer at next possible time, taking into account
1179 // request guard time and frame delay time
1180 // if == 0: transfer immediately and return time of transfer
1181 // if != 0: delay transfer until time specified
1182 //-------------------------------------------------------------------------------------
1183 static void TransmitFor14443a(const uint8_t *cmd, int len, uint32_t *timing)
1184 {
1185
1186 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1187
1188 uint32_t ThisTransferTime = 0;
1189
1190 if (timing) {
1191 if(*timing == 0) { // Measure time
1192 *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1193 } else {
1194 PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
1195 }
1196 if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
1197 while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
1198 LastTimeProxToAirStart = *timing;
1199 } else {
1200 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1201 while(GetCountSspClk() < ThisTransferTime);
1202 LastTimeProxToAirStart = ThisTransferTime;
1203 }
1204
1205 // clear TXRDY
1206 AT91C_BASE_SSC->SSC_THR = SEC_Y;
1207
1208 // for(uint16_t c = 0; c < 10;) { // standard delay for each transfer (allow tag to be ready after last transmission)
1209 // if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1210 // AT91C_BASE_SSC->SSC_THR = SEC_Y;
1211 // c++;
1212 // }
1213 // }
1214
1215 uint16_t c = 0;
1216 for(;;) {
1217 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1218 AT91C_BASE_SSC->SSC_THR = cmd[c];
1219 c++;
1220 if(c >= len) {
1221 break;
1222 }
1223 }
1224 }
1225
1226 NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1227
1228 }
1229
1230
1231 //-----------------------------------------------------------------------------
1232 // Prepare reader command (in bits, support short frames) to send to FPGA
1233 //-----------------------------------------------------------------------------
1234 void CodeIso14443aBitsAsReaderPar(const uint8_t * cmd, int bits, uint32_t dwParity)
1235 {
1236 int i, j;
1237 int last;
1238 uint8_t b;
1239
1240 ToSendReset();
1241
1242 // Start of Communication (Seq. Z)
1243 ToSend[++ToSendMax] = SEC_Z;
1244 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1245 last = 0;
1246
1247 size_t bytecount = nbytes(bits);
1248 // Generate send structure for the data bits
1249 for (i = 0; i < bytecount; i++) {
1250 // Get the current byte to send
1251 b = cmd[i];
1252 size_t bitsleft = MIN((bits-(i*8)),8);
1253
1254 for (j = 0; j < bitsleft; j++) {
1255 if (b & 1) {
1256 // Sequence X
1257 ToSend[++ToSendMax] = SEC_X;
1258 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1259 last = 1;
1260 } else {
1261 if (last == 0) {
1262 // Sequence Z
1263 ToSend[++ToSendMax] = SEC_Z;
1264 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1265 } else {
1266 // Sequence Y
1267 ToSend[++ToSendMax] = SEC_Y;
1268 last = 0;
1269 }
1270 }
1271 b >>= 1;
1272 }
1273
1274 // Only transmit (last) parity bit if we transmitted a complete byte
1275 if (j == 8) {
1276 // Get the parity bit
1277 if ((dwParity >> i) & 0x01) {
1278 // Sequence X
1279 ToSend[++ToSendMax] = SEC_X;
1280 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1281 last = 1;
1282 } else {
1283 if (last == 0) {
1284 // Sequence Z
1285 ToSend[++ToSendMax] = SEC_Z;
1286 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1287 } else {
1288 // Sequence Y
1289 ToSend[++ToSendMax] = SEC_Y;
1290 last = 0;
1291 }
1292 }
1293 }
1294 }
1295
1296 // End of Communication: Logic 0 followed by Sequence Y
1297 if (last == 0) {
1298 // Sequence Z
1299 ToSend[++ToSendMax] = SEC_Z;
1300 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1301 } else {
1302 // Sequence Y
1303 ToSend[++ToSendMax] = SEC_Y;
1304 last = 0;
1305 }
1306 ToSend[++ToSendMax] = SEC_Y;
1307
1308 // Convert to length of command:
1309 ToSendMax++;
1310 }
1311
1312 //-----------------------------------------------------------------------------
1313 // Prepare reader command to send to FPGA
1314 //-----------------------------------------------------------------------------
1315 void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity)
1316 {
1317 CodeIso14443aBitsAsReaderPar(cmd,len*8,dwParity);
1318 }
1319
1320 //-----------------------------------------------------------------------------
1321 // Wait for commands from reader
1322 // Stop when button is pressed (return 1) or field was gone (return 2)
1323 // Or return 0 when command is captured
1324 //-----------------------------------------------------------------------------
1325 static int EmGetCmd(uint8_t *received, int *len)
1326 {
1327 *len = 0;
1328
1329 uint32_t timer = 0, vtime = 0;
1330 int analogCnt = 0;
1331 int analogAVG = 0;
1332
1333 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1334 // only, since we are receiving, not transmitting).
1335 // Signal field is off with the appropriate LED
1336 LED_D_OFF();
1337 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1338
1339 // Set ADC to read field strength
1340 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1341 AT91C_BASE_ADC->ADC_MR =
1342 ADC_MODE_PRESCALE(32) |
1343 ADC_MODE_STARTUP_TIME(16) |
1344 ADC_MODE_SAMPLE_HOLD_TIME(8);
1345 AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1346 // start ADC
1347 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1348
1349 // Now run a 'software UART' on the stream of incoming samples.
1350 UartReset();
1351 Uart.output = received;
1352
1353 // Clear RXRDY:
1354 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1355
1356 for(;;) {
1357 WDT_HIT();
1358
1359 if (BUTTON_PRESS()) return 1;
1360
1361 // test if the field exists
1362 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1363 analogCnt++;
1364 analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1365 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1366 if (analogCnt >= 32) {
1367 if ((33000 * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1368 vtime = GetTickCount();
1369 if (!timer) timer = vtime;
1370 // 50ms no field --> card to idle state
1371 if (vtime - timer > 50) return 2;
1372 } else
1373 if (timer) timer = 0;
1374 analogCnt = 0;
1375 analogAVG = 0;
1376 }
1377 }
1378
1379 // receive and test the miller decoding
1380 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1381 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1382 if(MillerDecoding(b, 0)) {
1383 *len = Uart.len;
1384 return 0;
1385 }
1386 }
1387
1388 }
1389 }
1390
1391
1392 static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, bool correctionNeeded)
1393 {
1394 uint8_t b;
1395 uint16_t i = 0;
1396 uint32_t ThisTransferTime;
1397
1398 // Modulate Manchester
1399 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1400
1401 // include correction bit if necessary
1402 if (Uart.parityBits & 0x01) {
1403 correctionNeeded = TRUE;
1404 }
1405 if(correctionNeeded) {
1406 // 1236, so correction bit needed
1407 i = 0;
1408 } else {
1409 i = 1;
1410 }
1411
1412 // clear receiving shift register and holding register
1413 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1414 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1415 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1416 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1417
1418 // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1419 for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never
1420 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1421 if (AT91C_BASE_SSC->SSC_RHR) break;
1422 }
1423
1424 while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1425
1426 // Clear TXRDY:
1427 AT91C_BASE_SSC->SSC_THR = SEC_F;
1428
1429 // send cycle
1430 for(; i <= respLen; ) {
1431 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1432 AT91C_BASE_SSC->SSC_THR = resp[i++];
1433 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1434 }
1435
1436 if(BUTTON_PRESS()) {
1437 break;
1438 }
1439 }
1440
1441 // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1442 for (i = 0; i < 2 ; ) {
1443 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1444 AT91C_BASE_SSC->SSC_THR = SEC_F;
1445 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1446 i++;
1447 }
1448 }
1449
1450 LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
1451
1452 return 0;
1453 }
1454
1455 int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
1456 Code4bitAnswerAsTag(resp);
1457 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1458 // do the tracing for the previous reader request and this tag answer:
1459 EmLogTrace(Uart.output,
1460 Uart.len,
1461 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1462 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1463 Uart.parityBits,
1464 &resp,
1465 1,
1466 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1467 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1468 SwapBits(GetParity(&resp, 1), 1));
1469 return res;
1470 }
1471
1472 int EmSend4bit(uint8_t resp){
1473 return EmSend4bitEx(resp, false);
1474 }
1475
1476 int EmSendCmdExPar(uint8_t *resp, int respLen, bool correctionNeeded, uint32_t par){
1477 CodeIso14443aAsTagPar(resp, respLen, par);
1478 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1479 // do the tracing for the previous reader request and this tag answer:
1480 EmLogTrace(Uart.output,
1481 Uart.len,
1482 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1483 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1484 Uart.parityBits,
1485 resp,
1486 respLen,
1487 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1488 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1489 SwapBits(GetParity(resp, respLen), respLen));
1490 return res;
1491 }
1492
1493 int EmSendCmdEx(uint8_t *resp, int respLen, bool correctionNeeded){
1494 return EmSendCmdExPar(resp, respLen, correctionNeeded, GetParity(resp, respLen));
1495 }
1496
1497 int EmSendCmd(uint8_t *resp, int respLen){
1498 return EmSendCmdExPar(resp, respLen, false, GetParity(resp, respLen));
1499 }
1500
1501 int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par){
1502 return EmSendCmdExPar(resp, respLen, false, par);
1503 }
1504
1505 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint32_t reader_Parity,
1506 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint32_t tag_Parity)
1507 {
1508 if (tracing) {
1509 // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1510 // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1511 // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1512 uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1513 uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1514 uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1515 reader_EndTime = tag_StartTime - exact_fdt;
1516 reader_StartTime = reader_EndTime - reader_modlen;
1517 if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_Parity, TRUE)) {
1518 return FALSE;
1519 } else if (!LogTrace(NULL, 0, reader_EndTime, 0, TRUE)) {
1520 return FALSE;
1521 } else if (!LogTrace(tag_data, tag_len, tag_StartTime, tag_Parity, FALSE)) {
1522 return FALSE;
1523 } else {
1524 return (!LogTrace(NULL, 0, tag_EndTime, 0, FALSE));
1525 }
1526 } else {
1527 return TRUE;
1528 }
1529 }
1530
1531 //-----------------------------------------------------------------------------
1532 // Wait a certain time for tag response
1533 // If a response is captured return TRUE
1534 // If it takes too long return FALSE
1535 //-----------------------------------------------------------------------------
1536 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint16_t offset, int maxLen)
1537 {
1538 uint16_t c;
1539
1540 // Set FPGA mode to "reader listen mode", no modulation (listen
1541 // only, since we are receiving, not transmitting).
1542 // Signal field is on with the appropriate LED
1543 LED_D_ON();
1544 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1545
1546 // Now get the answer from the card
1547 DemodReset();
1548 Demod.output = receivedResponse;
1549
1550 // clear RXRDY:
1551 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1552
1553 c = 0;
1554 for(;;) {
1555 WDT_HIT();
1556
1557 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1558 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1559 if(ManchesterDecoding(b, offset, 0)) {
1560 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1561 return TRUE;
1562 } else if(c++ > iso14a_timeout) {
1563 return FALSE;
1564 }
1565 }
1566 }
1567 }
1568
1569 void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par, uint32_t *timing)
1570 {
1571
1572 CodeIso14443aBitsAsReaderPar(frame,bits,par);
1573
1574 // Send command to tag
1575 TransmitFor14443a(ToSend, ToSendMax, timing);
1576 if(trigger)
1577 LED_A_ON();
1578
1579 // Log reader command in trace buffer
1580 if (tracing) {
1581 LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
1582 LogTrace(NULL, 0, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, 0, TRUE);
1583 }
1584 }
1585
1586 void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par, uint32_t *timing)
1587 {
1588 ReaderTransmitBitsPar(frame,len*8,par, timing);
1589 }
1590
1591 void ReaderTransmitBits(uint8_t* frame, int len, uint32_t *timing)
1592 {
1593 // Generate parity and redirect
1594 ReaderTransmitBitsPar(frame,len,GetParity(frame,len/8), timing);
1595 }
1596
1597 void ReaderTransmit(uint8_t* frame, int len, uint32_t *timing)
1598 {
1599 // Generate parity and redirect
1600 ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len), timing);
1601 }
1602
1603 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset)
1604 {
1605 if (!GetIso14443aAnswerFromTag(receivedAnswer,offset,160)) return FALSE;
1606 if (tracing) {
1607 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.parityBits, FALSE);
1608 LogTrace(NULL, 0, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, 0, FALSE);
1609 }
1610 return Demod.len;
1611 }
1612
1613 int ReaderReceive(uint8_t* receivedAnswer)
1614 {
1615 return ReaderReceiveOffset(receivedAnswer, 0);
1616 }
1617
1618 int ReaderReceivePar(uint8_t *receivedAnswer, uint32_t *parptr)
1619 {
1620 if (!GetIso14443aAnswerFromTag(receivedAnswer,0,160)) return FALSE;
1621 if (tracing) {
1622 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.parityBits, FALSE);
1623 LogTrace(NULL, 0, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, 0, FALSE);
1624 }
1625 *parptr = Demod.parityBits;
1626 return Demod.len;
1627 }
1628
1629 /* performs iso14443a anticollision procedure
1630 * fills the uid pointer unless NULL
1631 * fills resp_data unless NULL */
1632 int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, uint32_t* cuid_ptr) {
1633 uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP
1634 uint8_t sel_all[] = { 0x93,0x20 };
1635 uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1636 uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1637 uint8_t* resp = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); // was 3560 - tied to other size changes
1638 byte_t uid_resp[4];
1639 size_t uid_resp_len;
1640
1641 uint8_t sak = 0x04; // cascade uid
1642 int cascade_level = 0;
1643 int len;
1644
1645 // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1646 ReaderTransmitBitsPar(wupa,7,0, NULL);
1647
1648 // Receive the ATQA
1649 if(!ReaderReceive(resp)) return 0;
1650 // Dbprintf("atqa: %02x %02x",resp[0],resp[1]);
1651
1652 if(p_hi14a_card) {
1653 memcpy(p_hi14a_card->atqa, resp, 2);
1654 p_hi14a_card->uidlen = 0;
1655 memset(p_hi14a_card->uid,0,10);
1656 }
1657
1658 // clear uid
1659 if (uid_ptr) {
1660 memset(uid_ptr,0,10);
1661 }
1662
1663 // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1664 // which case we need to make a cascade 2 request and select - this is a long UID
1665 // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1666 for(; sak & 0x04; cascade_level++) {
1667 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1668 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1669
1670 // SELECT_ALL
1671 ReaderTransmit(sel_all,sizeof(sel_all), NULL);
1672 if (!ReaderReceive(resp)) return 0;
1673
1674 if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit
1675 memset(uid_resp, 0, 4);
1676 uint16_t uid_resp_bits = 0;
1677 uint16_t collision_answer_offset = 0;
1678 // anti-collision-loop:
1679 while (Demod.collisionPos) {
1680 Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1681 for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point
1682 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1683 uid_resp[uid_resp_bits & 0xf8] |= UIDbit << (uid_resp_bits % 8);
1684 }
1685 uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position
1686 uid_resp_bits++;
1687 // construct anticollosion command:
1688 sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits
1689 for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1690 sel_uid[2+i] = uid_resp[i];
1691 }
1692 collision_answer_offset = uid_resp_bits%8;
1693 ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1694 if (!ReaderReceiveOffset(resp, collision_answer_offset)) return 0;
1695 }
1696 // finally, add the last bits and BCC of the UID
1697 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1698 uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1699 uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1700 }
1701
1702 } else { // no collision, use the response to SELECT_ALL as current uid
1703 memcpy(uid_resp,resp,4);
1704 }
1705 uid_resp_len = 4;
1706 // Dbprintf("uid: %02x %02x %02x %02x",uid_resp[0],uid_resp[1],uid_resp[2],uid_resp[3]);
1707
1708 // calculate crypto UID. Always use last 4 Bytes.
1709 if(cuid_ptr) {
1710 *cuid_ptr = bytes_to_num(uid_resp, 4);
1711 }
1712
1713 // Construct SELECT UID command
1714 sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1715 memcpy(sel_uid+2,uid_resp,4); // the UID
1716 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC
1717 AppendCrc14443a(sel_uid,7); // calculate and add CRC
1718 ReaderTransmit(sel_uid,sizeof(sel_uid), NULL);
1719
1720 // Receive the SAK
1721 if (!ReaderReceive(resp)) return 0;
1722 sak = resp[0];
1723
1724 // Test if more parts of the uid are comming
1725 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
1726 // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
1727 // http://www.nxp.com/documents/application_note/AN10927.pdf
1728 memcpy(uid_resp, uid_resp + 1, 3);
1729 uid_resp_len = 3;
1730 }
1731
1732 if(uid_ptr) {
1733 memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
1734 }
1735
1736 if(p_hi14a_card) {
1737 memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
1738 p_hi14a_card->uidlen += uid_resp_len;
1739 }
1740 }
1741
1742 if(p_hi14a_card) {
1743 p_hi14a_card->sak = sak;
1744 p_hi14a_card->ats_len = 0;
1745 }
1746
1747 if( (sak & 0x20) == 0) {
1748 return 2; // non iso14443a compliant tag
1749 }
1750
1751 // Request for answer to select
1752 AppendCrc14443a(rats, 2);
1753 ReaderTransmit(rats, sizeof(rats), NULL);
1754
1755 if (!(len = ReaderReceive(resp))) return 0;
1756
1757 if(p_hi14a_card) {
1758 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
1759 p_hi14a_card->ats_len = len;
1760 }
1761
1762 // reset the PCB block number
1763 iso14_pcb_blocknum = 0;
1764 return 1;
1765 }
1766
1767 void iso14443a_setup(uint8_t fpga_minor_mode) {
1768 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1769 // Set up the synchronous serial port
1770 FpgaSetupSsc();
1771 // connect Demodulated Signal to ADC:
1772 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1773
1774 // Signal field is on with the appropriate LED
1775 if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
1776 || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
1777 LED_D_ON();
1778 } else {
1779 LED_D_OFF();
1780 }
1781 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
1782
1783 // Start the timer
1784 StartCountSspClk();
1785
1786 DemodReset();
1787 UartReset();
1788 NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
1789 iso14a_set_timeout(1050); // 10ms default 10*105 =
1790 }
1791
1792 int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) {
1793 uint8_t real_cmd[cmd_len+4];
1794 real_cmd[0] = 0x0a; //I-Block
1795 // put block number into the PCB
1796 real_cmd[0] |= iso14_pcb_blocknum;
1797 real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
1798 memcpy(real_cmd+2, cmd, cmd_len);
1799 AppendCrc14443a(real_cmd,cmd_len+2);
1800
1801 ReaderTransmit(real_cmd, cmd_len+4, NULL);
1802 size_t len = ReaderReceive(data);
1803 uint8_t * data_bytes = (uint8_t *) data;
1804 if (!len)
1805 return 0; //DATA LINK ERROR
1806 // if we received an I- or R(ACK)-Block with a block number equal to the
1807 // current block number, toggle the current block number
1808 else if (len >= 4 // PCB+CID+CRC = 4 bytes
1809 && ((data_bytes[0] & 0xC0) == 0 // I-Block
1810 || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
1811 && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
1812 {
1813 iso14_pcb_blocknum ^= 1;
1814 }
1815
1816 return len;
1817 }
1818
1819 //-----------------------------------------------------------------------------
1820 // Read an ISO 14443a tag. Send out commands and store answers.
1821 //
1822 //-----------------------------------------------------------------------------
1823 void ReaderIso14443a(UsbCommand *c)
1824 {
1825 iso14a_command_t param = c->arg[0];
1826 uint8_t *cmd = c->d.asBytes;
1827 size_t len = c->arg[1] & 0xFFFF;
1828 size_t lenbits = c->arg[1] >> 16;
1829 uint32_t arg0 = 0;
1830 byte_t buf[USB_CMD_DATA_SIZE];
1831
1832 if(param & ISO14A_CONNECT) {
1833 iso14a_clear_trace();
1834 }
1835
1836 iso14a_set_tracing(TRUE);
1837
1838 if(param & ISO14A_REQUEST_TRIGGER) {
1839 iso14a_set_trigger(TRUE);
1840 }
1841
1842 if(param & ISO14A_CONNECT) {
1843 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
1844 if(!(param & ISO14A_NO_SELECT)) {
1845 iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
1846 arg0 = iso14443a_select_card(NULL,card,NULL);
1847 cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
1848 }
1849 }
1850
1851 if(param & ISO14A_SET_TIMEOUT) {
1852 iso14a_set_timeout(c->arg[2]);
1853 }
1854
1855 if(param & ISO14A_APDU) {
1856 arg0 = iso14_apdu(cmd, len, buf);
1857 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
1858 }
1859
1860 if(param & ISO14A_RAW) {
1861 if(param & ISO14A_APPEND_CRC) {
1862 AppendCrc14443a(cmd,len);
1863 len += 2;
1864 lenbits += 16;
1865 }
1866 if(lenbits>0) {
1867
1868 ReaderTransmitBitsPar(cmd,lenbits,GetParity(cmd,lenbits/8), NULL);
1869 } else {
1870 ReaderTransmit(cmd,len, NULL);
1871 }
1872 arg0 = ReaderReceive(buf);
1873 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
1874 }
1875
1876 if(param & ISO14A_REQUEST_TRIGGER) {
1877 iso14a_set_trigger(FALSE);
1878 }
1879
1880 if(param & ISO14A_NO_DISCONNECT) {
1881 return;
1882 }
1883
1884 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1885 LEDsoff();
1886 }
1887
1888
1889 // Determine the distance between two nonces.
1890 // Assume that the difference is small, but we don't know which is first.
1891 // Therefore try in alternating directions.
1892 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
1893
1894 uint16_t i;
1895 uint32_t nttmp1, nttmp2;
1896
1897 if (nt1 == nt2) return 0;
1898
1899 nttmp1 = nt1;
1900 nttmp2 = nt2;
1901
1902 for (i = 1; i < 32768; i++) {
1903 nttmp1 = prng_successor(nttmp1, 1);
1904 if (nttmp1 == nt2) return i;
1905 nttmp2 = prng_successor(nttmp2, 1);
1906 if (nttmp2 == nt1) return -i;
1907 }
1908
1909 return(-99999); // either nt1 or nt2 are invalid nonces
1910 }
1911
1912
1913 //-----------------------------------------------------------------------------
1914 // Recover several bits of the cypher stream. This implements (first stages of)
1915 // the algorithm described in "The Dark Side of Security by Obscurity and
1916 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
1917 // (article by Nicolas T. Courtois, 2009)
1918 //-----------------------------------------------------------------------------
1919 void ReaderMifare(bool first_try)
1920 {
1921 // Mifare AUTH
1922 uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b };
1923 uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
1924 static uint8_t mf_nr_ar3;
1925
1926 uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
1927
1928 iso14a_clear_trace();
1929 iso14a_set_tracing(TRUE);
1930
1931 byte_t nt_diff = 0;
1932 byte_t par = 0;
1933 //byte_t par_mask = 0xff;
1934 static byte_t par_low = 0;
1935 bool led_on = TRUE;
1936 uint8_t uid[10];
1937 uint32_t cuid;
1938
1939 uint32_t nt, previous_nt;
1940 static uint32_t nt_attacked = 0;
1941 byte_t par_list[8] = {0,0,0,0,0,0,0,0};
1942 byte_t ks_list[8] = {0,0,0,0,0,0,0,0};
1943
1944 static uint32_t sync_time;
1945 static uint32_t sync_cycles;
1946 int catch_up_cycles = 0;
1947 int last_catch_up = 0;
1948 uint16_t consecutive_resyncs = 0;
1949 int isOK = 0;
1950
1951
1952
1953 if (first_try) {
1954 mf_nr_ar3 = 0;
1955 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
1956 sync_time = GetCountSspClk() & 0xfffffff8;
1957 sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
1958 nt_attacked = 0;
1959 nt = 0;
1960 par = 0;
1961 }
1962 else {
1963 // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
1964 // nt_attacked = prng_successor(nt_attacked, 1);
1965 mf_nr_ar3++;
1966 mf_nr_ar[3] = mf_nr_ar3;
1967 par = par_low;
1968 }
1969
1970 LED_A_ON();
1971 LED_B_OFF();
1972 LED_C_OFF();
1973
1974
1975 for(uint16_t i = 0; TRUE; i++) {
1976
1977 WDT_HIT();
1978
1979 // Test if the action was cancelled
1980 if(BUTTON_PRESS()) {
1981 break;
1982 }
1983
1984 LED_C_ON();
1985
1986 if(!iso14443a_select_card(uid, NULL, &cuid)) {
1987 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
1988 continue;
1989 }
1990
1991 sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
1992 catch_up_cycles = 0;
1993
1994 // if we missed the sync time already, advance to the next nonce repeat
1995 while(GetCountSspClk() > sync_time) {
1996 sync_time = (sync_time & 0xfffffff8) + sync_cycles;
1997 }
1998
1999 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2000 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2001
2002 // Receive the (4 Byte) "random" nonce
2003 if (!ReaderReceive(receivedAnswer)) {
2004 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce");
2005 continue;
2006 }
2007
2008 previous_nt = nt;
2009 nt = bytes_to_num(receivedAnswer, 4);
2010
2011 // Transmit reader nonce with fake par
2012 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2013
2014 if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
2015 int nt_distance = dist_nt(previous_nt, nt);
2016 if (nt_distance == 0) {
2017 nt_attacked = nt;
2018 }
2019 else {
2020 if (nt_distance == -99999) { // invalid nonce received, try again
2021 continue;
2022 }
2023 sync_cycles = (sync_cycles - nt_distance);
2024 if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
2025 continue;
2026 }
2027 }
2028
2029 if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
2030 catch_up_cycles = -dist_nt(nt_attacked, nt);
2031 if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one.
2032 catch_up_cycles = 0;
2033 continue;
2034 }
2035 if (catch_up_cycles == last_catch_up) {
2036 consecutive_resyncs++;
2037 }
2038 else {
2039 last_catch_up = catch_up_cycles;
2040 consecutive_resyncs = 0;
2041 }
2042 if (consecutive_resyncs < 3) {
2043 if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, -catch_up_cycles, consecutive_resyncs);
2044 }
2045 else {
2046 sync_cycles = sync_cycles + catch_up_cycles;
2047 if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d for the fourth time consecutively (nt_distance = %d). Adjusting sync_cycles to %d.\n", i, -catch_up_cycles, sync_cycles);
2048 }
2049 continue;
2050 }
2051
2052 consecutive_resyncs = 0;
2053
2054 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2055 if (ReaderReceive(receivedAnswer))
2056 {
2057 catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2058
2059 if (nt_diff == 0)
2060 {
2061 par_low = par & 0x07; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change
2062 }
2063
2064 led_on = !led_on;
2065 if(led_on) LED_B_ON(); else LED_B_OFF();
2066
2067 par_list[nt_diff] = par;
2068 ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
2069
2070 // Test if the information is complete
2071 if (nt_diff == 0x07) {
2072 isOK = 1;
2073 break;
2074 }
2075
2076 nt_diff = (nt_diff + 1) & 0x07;
2077 mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2078 par = par_low;
2079 } else {
2080 if (nt_diff == 0 && first_try)
2081 {
2082 par++;
2083 } else {
2084 par = (((par >> 3) + 1) << 3) | par_low;
2085 }
2086 }
2087 }
2088
2089
2090 mf_nr_ar[3] &= 0x1F;
2091
2092 byte_t buf[28];
2093 memcpy(buf + 0, uid, 4);
2094 num_to_bytes(nt, 4, buf + 4);
2095 memcpy(buf + 8, par_list, 8);
2096 memcpy(buf + 16, ks_list, 8);
2097 memcpy(buf + 24, mf_nr_ar, 4);
2098
2099 cmd_send(CMD_ACK,isOK,0,0,buf,28);
2100
2101 // Thats it...
2102 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2103 LEDsoff();
2104
2105 iso14a_set_tracing(FALSE);
2106 }
2107
2108 /**
2109 *MIFARE 1K simulate.
2110 *
2111 *@param flags :
2112 * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2113 * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
2114 * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
2115 * FLAG_NR_AR_ATTACK - means we should collect NR_AR responses for bruteforcing later
2116 *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2117 */
2118 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
2119 {
2120 int cardSTATE = MFEMUL_NOFIELD;
2121 int _7BUID = 0;
2122 int vHf = 0; // in mV
2123 int res;
2124 uint32_t selTimer = 0;
2125 uint32_t authTimer = 0;
2126 uint32_t par = 0;
2127 int len = 0;
2128 uint8_t cardWRBL = 0;
2129 uint8_t cardAUTHSC = 0;
2130 uint8_t cardAUTHKEY = 0xff; // no authentication
2131 uint32_t cardRr = 0;
2132 uint32_t cuid = 0;
2133 //uint32_t rn_enc = 0;
2134 uint32_t ans = 0;
2135 uint32_t cardINTREG = 0;
2136 uint8_t cardINTBLOCK = 0;
2137 struct Crypto1State mpcs = {0, 0};
2138 struct Crypto1State *pcs;
2139 pcs = &mpcs;
2140 uint32_t numReads = 0;//Counts numer of times reader read a block
2141 uint8_t* receivedCmd = eml_get_bigbufptr_recbuf();
2142 uint8_t *response = eml_get_bigbufptr_sendbuf();
2143
2144 uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
2145 uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2146 uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
2147 uint8_t rSAK[] = {0x08, 0xb6, 0xdd};
2148 uint8_t rSAK1[] = {0x04, 0xda, 0x17};
2149
2150 uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04};
2151 uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2152
2153 //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
2154 // This can be used in a reader-only attack.
2155 // (it can also be retrieved via 'hf 14a list', but hey...
2156 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
2157 uint8_t ar_nr_collected = 0;
2158
2159 // clear trace
2160 iso14a_clear_trace();
2161 iso14a_set_tracing(TRUE);
2162
2163 // Authenticate response - nonce
2164 uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2165
2166 //-- Determine the UID
2167 // Can be set from emulator memory, incoming data
2168 // and can be 7 or 4 bytes long
2169 if (flags & FLAG_4B_UID_IN_DATA)
2170 {
2171 // 4B uid comes from data-portion of packet
2172 memcpy(rUIDBCC1,datain,4);
2173 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2174
2175 } else if (flags & FLAG_7B_UID_IN_DATA) {
2176 // 7B uid comes from data-portion of packet
2177 memcpy(&rUIDBCC1[1],datain,3);
2178 memcpy(rUIDBCC2, datain+3, 4);
2179 _7BUID = true;
2180 } else {
2181 // get UID from emul memory
2182 emlGetMemBt(receivedCmd, 7, 1);
2183 _7BUID = !(receivedCmd[0] == 0x00);
2184 if (!_7BUID) { // ---------- 4BUID
2185 emlGetMemBt(rUIDBCC1, 0, 4);
2186 } else { // ---------- 7BUID
2187 emlGetMemBt(&rUIDBCC1[1], 0, 3);
2188 emlGetMemBt(rUIDBCC2, 3, 4);
2189 }
2190 }
2191
2192 /*
2193 * Regardless of what method was used to set the UID, set fifth byte and modify
2194 * the ATQA for 4 or 7-byte UID
2195 */
2196 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2197 if (_7BUID) {
2198 rATQA[0] = 0x44;
2199 rUIDBCC1[0] = 0x88;
2200 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2201 }
2202
2203 // We need to listen to the high-frequency, peak-detected path.
2204 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2205
2206
2207 if (MF_DBGLEVEL >= 1) {
2208 if (!_7BUID) {
2209 Dbprintf("4B UID: %02x%02x%02x%02x",rUIDBCC1[0] , rUIDBCC1[1] , rUIDBCC1[2] , rUIDBCC1[3]);
2210 } else {
2211 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]);
2212 }
2213 }
2214
2215 bool finished = FALSE;
2216 while (!BUTTON_PRESS() && !finished) {
2217 WDT_HIT();
2218
2219 // find reader field
2220 // Vref = 3300mV, and an 10:1 voltage divider on the input
2221 // can measure voltages up to 33000 mV
2222 if (cardSTATE == MFEMUL_NOFIELD) {
2223 vHf = (33000 * AvgAdc(ADC_CHAN_HF)) >> 10;
2224 if (vHf > MF_MINFIELDV) {
2225 cardSTATE_TO_IDLE();
2226 LED_A_ON();
2227 }
2228 }
2229 if(cardSTATE == MFEMUL_NOFIELD) continue;
2230
2231 //Now, get data
2232
2233 res = EmGetCmd(receivedCmd, &len);
2234 if (res == 2) { //Field is off!
2235 cardSTATE = MFEMUL_NOFIELD;
2236 LEDsoff();
2237 continue;
2238 } else if (res == 1) {
2239 break; //return value 1 means button press
2240 }
2241
2242 // REQ or WUP request in ANY state and WUP in HALTED state
2243 if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
2244 selTimer = GetTickCount();
2245 EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
2246 cardSTATE = MFEMUL_SELECT1;
2247
2248 // init crypto block
2249 LED_B_OFF();
2250 LED_C_OFF();
2251 crypto1_destroy(pcs);
2252 cardAUTHKEY = 0xff;
2253 continue;
2254 }
2255
2256 switch (cardSTATE) {
2257 case MFEMUL_NOFIELD:
2258 case MFEMUL_HALTED:
2259 case MFEMUL_IDLE:{
2260 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2261 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2262 break;
2263 }
2264 case MFEMUL_SELECT1:{
2265 // select all
2266 if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
2267 if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received");
2268 EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2269 break;
2270 }
2271
2272 if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
2273 {
2274 Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
2275 }
2276 // select card
2277 if (len == 9 &&
2278 (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2279 EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK));
2280 cuid = bytes_to_num(rUIDBCC1, 4);
2281 if (!_7BUID) {
2282 cardSTATE = MFEMUL_WORK;
2283 LED_B_ON();
2284 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2285 break;
2286 } else {
2287 cardSTATE = MFEMUL_SELECT2;
2288 }
2289 }
2290 break;
2291 }
2292 case MFEMUL_AUTH1:{
2293 if( len != 8)
2294 {
2295 cardSTATE_TO_IDLE();
2296 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2297 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2298 break;
2299 }
2300 uint32_t ar = bytes_to_num(receivedCmd, 4);
2301 uint32_t nr= bytes_to_num(&receivedCmd[4], 4);
2302
2303 //Collect AR/NR
2304 if(ar_nr_collected < 2){
2305 if(ar_nr_responses[2] != ar)
2306 {// Avoid duplicates... probably not necessary, ar should vary.
2307 ar_nr_responses[ar_nr_collected*4] = cuid;
2308 ar_nr_responses[ar_nr_collected*4+1] = nonce;
2309 ar_nr_responses[ar_nr_collected*4+2] = ar;
2310 ar_nr_responses[ar_nr_collected*4+3] = nr;
2311 ar_nr_collected++;
2312 }
2313 }
2314
2315 // --- crypto
2316 crypto1_word(pcs, ar , 1);
2317 cardRr = nr ^ crypto1_word(pcs, 0, 0);
2318
2319 // test if auth OK
2320 if (cardRr != prng_successor(nonce, 64)){
2321 if (MF_DBGLEVEL >= 2) Dbprintf("AUTH FAILED. cardRr=%08x, succ=%08x",cardRr, prng_successor(nonce, 64));
2322 // Shouldn't we respond anything here?
2323 // Right now, we don't nack or anything, which causes the
2324 // reader to do a WUPA after a while. /Martin
2325 // -- which is the correct response. /piwi
2326 cardSTATE_TO_IDLE();
2327 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2328 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2329 break;
2330 }
2331
2332 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2333
2334 num_to_bytes(ans, 4, rAUTH_AT);
2335 // --- crypto
2336 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2337 LED_C_ON();
2338 cardSTATE = MFEMUL_WORK;
2339 if (MF_DBGLEVEL >= 4) Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2340 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2341 GetTickCount() - authTimer);
2342 break;
2343 }
2344 case MFEMUL_SELECT2:{
2345 if (!len) {
2346 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2347 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2348 break;
2349 }
2350 if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
2351 EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2352 break;
2353 }
2354
2355 // select 2 card
2356 if (len == 9 &&
2357 (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
2358 EmSendCmd(rSAK, sizeof(rSAK));
2359 cuid = bytes_to_num(rUIDBCC2, 4);
2360 cardSTATE = MFEMUL_WORK;
2361 LED_B_ON();
2362 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2363 break;
2364 }
2365
2366 // i guess there is a command). go into the work state.
2367 if (len != 4) {
2368 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2369 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2370 break;
2371 }
2372 cardSTATE = MFEMUL_WORK;
2373 //goto lbWORK;
2374 //intentional fall-through to the next case-stmt
2375 }
2376
2377 case MFEMUL_WORK:{
2378 if (len == 0) {
2379 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2380 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2381 break;
2382 }
2383
2384 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2385
2386 if(encrypted_data) {
2387 // decrypt seqence
2388 mf_crypto1_decrypt(pcs, receivedCmd, len);
2389 }
2390
2391 if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
2392 authTimer = GetTickCount();
2393 cardAUTHSC = receivedCmd[1] / 4; // received block num
2394 cardAUTHKEY = receivedCmd[0] - 0x60;
2395 crypto1_destroy(pcs);//Added by martin
2396 crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2397
2398 if (!encrypted_data) { // first authentication
2399 if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2400
2401 crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
2402 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2403 } else { // nested authentication
2404 if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2405 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2406 num_to_bytes(ans, 4, rAUTH_AT);
2407 }
2408 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2409 //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
2410 cardSTATE = MFEMUL_AUTH1;
2411 break;
2412 }
2413
2414 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2415 // BUT... ACK --> NACK
2416 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2417 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2418 break;
2419 }
2420
2421 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2422 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2423 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2424 break;
2425 }
2426
2427 if(len != 4) {
2428 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2429 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2430 break;
2431 }
2432
2433 if(receivedCmd[0] == 0x30 // read block
2434 || receivedCmd[0] == 0xA0 // write block
2435 || receivedCmd[0] == 0xC0 // inc
2436 || receivedCmd[0] == 0xC1 // dec
2437 || receivedCmd[0] == 0xC2 // restore
2438 || receivedCmd[0] == 0xB0) { // transfer
2439 if (receivedCmd[1] >= 16 * 4) {
2440 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2441 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]);
2442 break;
2443 }
2444
2445 if (receivedCmd[1] / 4 != cardAUTHSC) {
2446 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2447 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);
2448 break;
2449 }
2450 }
2451 // read block
2452 if (receivedCmd[0] == 0x30) {
2453 if (MF_DBGLEVEL >= 4) {
2454 Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
2455 }
2456 emlGetMem(response, receivedCmd[1], 1);
2457 AppendCrc14443a(response, 16);
2458 mf_crypto1_encrypt(pcs, response, 18, &par);
2459 EmSendCmdPar(response, 18, par);
2460 numReads++;
2461 if(exitAfterNReads > 0 && numReads == exitAfterNReads) {
2462 Dbprintf("%d reads done, exiting", numReads);
2463 finished = true;
2464 }
2465 break;
2466 }
2467 // write block
2468 if (receivedCmd[0] == 0xA0) {
2469 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
2470 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2471 cardSTATE = MFEMUL_WRITEBL2;
2472 cardWRBL = receivedCmd[1];
2473 break;
2474 }
2475 // increment, decrement, restore
2476 if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
2477 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2478 if (emlCheckValBl(receivedCmd[1])) {
2479 if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2480 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2481 break;
2482 }
2483 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2484 if (receivedCmd[0] == 0xC1)
2485 cardSTATE = MFEMUL_INTREG_INC;
2486 if (receivedCmd[0] == 0xC0)
2487 cardSTATE = MFEMUL_INTREG_DEC;
2488 if (receivedCmd[0] == 0xC2)
2489 cardSTATE = MFEMUL_INTREG_REST;
2490 cardWRBL = receivedCmd[1];
2491 break;
2492 }
2493 // transfer
2494 if (receivedCmd[0] == 0xB0) {
2495 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2496 if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2497 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2498 else
2499 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2500 break;
2501 }
2502 // halt
2503 if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
2504 LED_B_OFF();
2505 LED_C_OFF();
2506 cardSTATE = MFEMUL_HALTED;
2507 if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer);
2508 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2509 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2510 break;
2511 }
2512 // RATS
2513 if (receivedCmd[0] == 0xe0) {//RATS
2514 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2515 break;
2516 }
2517 // command not allowed
2518 if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking");
2519 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2520 break;
2521 }
2522 case MFEMUL_WRITEBL2:{
2523 if (len == 18){
2524 mf_crypto1_decrypt(pcs, receivedCmd, len);
2525 emlSetMem(receivedCmd, cardWRBL, 1);
2526 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2527 cardSTATE = MFEMUL_WORK;
2528 } else {
2529 cardSTATE_TO_IDLE();
2530 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2531 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2532 }
2533 break;
2534 }
2535
2536 case MFEMUL_INTREG_INC:{
2537 mf_crypto1_decrypt(pcs, receivedCmd, len);
2538 memcpy(&ans, receivedCmd, 4);
2539 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2540 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2541 cardSTATE_TO_IDLE();
2542 break;
2543 }
2544 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2545 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2546 cardINTREG = cardINTREG + ans;
2547 cardSTATE = MFEMUL_WORK;
2548 break;
2549 }
2550 case MFEMUL_INTREG_DEC:{
2551 mf_crypto1_decrypt(pcs, receivedCmd, len);
2552 memcpy(&ans, receivedCmd, 4);
2553 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2554 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2555 cardSTATE_TO_IDLE();
2556 break;
2557 }
2558 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2559 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2560 cardINTREG = cardINTREG - ans;
2561 cardSTATE = MFEMUL_WORK;
2562 break;
2563 }
2564 case MFEMUL_INTREG_REST:{
2565 mf_crypto1_decrypt(pcs, receivedCmd, len);
2566 memcpy(&ans, receivedCmd, 4);
2567 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2568 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2569 cardSTATE_TO_IDLE();
2570 break;
2571 }
2572 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parityBits, TRUE);
2573 LogTrace(NULL, 0, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, 0, TRUE);
2574 cardSTATE = MFEMUL_WORK;
2575 break;
2576 }
2577 }
2578 }
2579
2580 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2581 LEDsoff();
2582
2583 if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
2584 {
2585 //May just aswell send the collected ar_nr in the response aswell
2586 cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_responses,ar_nr_collected*4*4);
2587 }
2588
2589 if(flags & FLAG_NR_AR_ATTACK)
2590 {
2591 if(ar_nr_collected > 1) {
2592 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
2593 Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
2594 ar_nr_responses[0], // UID
2595 ar_nr_responses[1], //NT
2596 ar_nr_responses[2], //AR1
2597 ar_nr_responses[3], //NR1
2598 ar_nr_responses[6], //AR2
2599 ar_nr_responses[7] //NR2
2600 );
2601 } else {
2602 Dbprintf("Failed to obtain two AR/NR pairs!");
2603 if(ar_nr_collected >0) {
2604 Dbprintf("Only got these: UID=%08x, nonce=%08x, AR1=%08x, NR1=%08x",
2605 ar_nr_responses[0], // UID
2606 ar_nr_responses[1], //NT
2607 ar_nr_responses[2], //AR1
2608 ar_nr_responses[3] //NR1
2609 );
2610 }
2611 }
2612 }
2613 if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, traceLen);
2614 }
2615
2616
2617
2618 //-----------------------------------------------------------------------------
2619 // MIFARE sniffer.
2620 //
2621 //-----------------------------------------------------------------------------
2622 void RAMFUNC SniffMifare(uint8_t param) {
2623 // param:
2624 // bit 0 - trigger from first card answer
2625 // bit 1 - trigger from first reader 7-bit request
2626
2627 // C(red) A(yellow) B(green)
2628 LEDsoff();
2629 // init trace buffer
2630 iso14a_clear_trace();
2631 iso14a_set_tracing(TRUE);
2632
2633 // The command (reader -> tag) that we're receiving.
2634 // The length of a received command will in most cases be no more than 18 bytes.
2635 // So 32 should be enough!
2636 uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
2637 // The response (tag -> reader) that we're receiving.
2638 uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
2639
2640 // As we receive stuff, we copy it from receivedCmd or receivedResponse
2641 // into trace, along with its length and other annotations.
2642 //uint8_t *trace = (uint8_t *)BigBuf;
2643
2644 // The DMA buffer, used to stream samples from the FPGA
2645 uint8_t *dmaBuf = ((uint8_t *)BigBuf) + DMA_BUFFER_OFFSET;
2646 uint8_t *data = dmaBuf;
2647 uint8_t previous_data = 0;
2648 int maxDataLen = 0;
2649 int dataLen = 0;
2650 bool ReaderIsActive = FALSE;
2651 bool TagIsActive = FALSE;
2652
2653 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
2654
2655 // Set up the demodulator for tag -> reader responses.
2656 Demod.output = receivedResponse;
2657
2658 // Set up the demodulator for the reader -> tag commands
2659 Uart.output = receivedCmd;
2660
2661 // Setup for the DMA.
2662 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2663
2664 LED_D_OFF();
2665
2666 // init sniffer
2667 MfSniffInit();
2668
2669 // And now we loop, receiving samples.
2670 for(uint32_t sniffCounter = 0; TRUE; ) {
2671
2672 if(BUTTON_PRESS()) {
2673 DbpString("cancelled by button");
2674 break;
2675 }
2676
2677 LED_A_ON();
2678 WDT_HIT();
2679
2680 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
2681 // check if a transaction is completed (timeout after 2000ms).
2682 // if yes, stop the DMA transfer and send what we have so far to the client
2683 if (MfSniffSend(2000)) {
2684 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
2685 sniffCounter = 0;
2686 data = dmaBuf;
2687 maxDataLen = 0;
2688 ReaderIsActive = FALSE;
2689 TagIsActive = FALSE;
2690 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2691 }
2692 }
2693
2694 int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
2695 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
2696 if (readBufDataP <= dmaBufDataP){ // we are processing the same block of data which is currently being transferred
2697 dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
2698 } else {
2699 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
2700 }
2701 // test for length of buffer
2702 if(dataLen > maxDataLen) { // we are more behind than ever...
2703 maxDataLen = dataLen;
2704 if(dataLen > 400) {
2705 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
2706 break;
2707 }
2708 }
2709 if(dataLen < 1) continue;
2710
2711 // primary buffer was stopped ( <-- we lost data!
2712 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
2713 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
2714 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
2715 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
2716 }
2717 // secondary buffer sets as primary, secondary buffer was stopped
2718 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
2719 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
2720 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
2721 }
2722
2723 LED_A_OFF();
2724
2725 if (sniffCounter & 0x01) {
2726
2727 if(!TagIsActive) { // no need to try decoding tag data if the reader is sending
2728 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
2729 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
2730 LED_C_INV();
2731 if (MfSniffLogic(receivedCmd, Uart.len, Uart.parityBits, Uart.bitCount, TRUE)) break;
2732
2733 /* And ready to receive another command. */
2734 UartReset();
2735
2736 /* And also reset the demod code */
2737 DemodReset();
2738 }
2739 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
2740 }
2741
2742 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending
2743 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
2744 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
2745 LED_C_INV();
2746
2747 if (MfSniffLogic(receivedResponse, Demod.len, Demod.parityBits, Demod.bitCount, FALSE)) break;
2748
2749 // And ready to receive another response.
2750 DemodReset();
2751 }
2752 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
2753 }
2754 }
2755
2756 previous_data = *data;
2757 sniffCounter++;
2758 data++;
2759 if(data == dmaBuf + DMA_BUFFER_SIZE) {
2760 data = dmaBuf;
2761 }
2762
2763 } // main cycle
2764
2765 DbpString("COMMAND FINISHED");
2766
2767 FpgaDisableSscDma();
2768 MfSniffEnd();
2769
2770 Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
2771 LEDsoff();
2772 }
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