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1 //-----------------------------------------------------------------------------
2 // Merlok - June 2011, 2012
3 // Gerhard de Koning Gans - May 2008
4 // Hagen Fritsch - June 2010
5 //
6 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
7 // at your option, any later version. See the LICENSE.txt file for the text of
8 // the license.
9 //-----------------------------------------------------------------------------
10 // Routines to support ISO 14443 type A.
11 //-----------------------------------------------------------------------------
12 #include "iso14443a.h"
13
14 static uint32_t iso14a_timeout;
15 int rsamples = 0;
16 uint8_t trigger = 0;
17 // the block number for the ISO14443-4 PCB
18 static uint8_t iso14_pcb_blocknum = 0;
19
20 static uint8_t* free_buffer_pointer;
21
22 //
23 // ISO14443 timing:
24 //
25 // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
26 #define REQUEST_GUARD_TIME (7000/16 + 1)
27 // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
28 #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
29 // bool LastCommandWasRequest = FALSE;
30
31 //
32 // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
33 //
34 // When the PM acts as reader and is receiving tag data, it takes
35 // 3 ticks delay in the AD converter
36 // 16 ticks until the modulation detector completes and sets curbit
37 // 8 ticks until bit_to_arm is assigned from curbit
38 // 8*16 ticks for the transfer from FPGA to ARM
39 // 4*16 ticks until we measure the time
40 // - 8*16 ticks because we measure the time of the previous transfer
41 #define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
42
43 // When the PM acts as a reader and is sending, it takes
44 // 4*16 ticks until we can write data to the sending hold register
45 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
46 // 8 ticks until the first transfer starts
47 // 8 ticks later the FPGA samples the data
48 // 1 tick to assign mod_sig_coil
49 #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
50
51 // When the PM acts as tag and is receiving it takes
52 // 2 ticks delay in the RF part (for the first falling edge),
53 // 3 ticks for the A/D conversion,
54 // 8 ticks on average until the start of the SSC transfer,
55 // 8 ticks until the SSC samples the first data
56 // 7*16 ticks to complete the transfer from FPGA to ARM
57 // 8 ticks until the next ssp_clk rising edge
58 // 4*16 ticks until we measure the time
59 // - 8*16 ticks because we measure the time of the previous transfer
60 #define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
61
62 // The FPGA will report its internal sending delay in
63 uint16_t FpgaSendQueueDelay;
64 // the 5 first bits are the number of bits buffered in mod_sig_buf
65 // the last three bits are the remaining ticks/2 after the mod_sig_buf shift
66 #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
67
68 // When the PM acts as tag and is sending, it takes
69 // 4*16 ticks until we can write data to the sending hold register
70 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
71 // 8 ticks until the first transfer starts
72 // 8 ticks later the FPGA samples the data
73 // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
74 // + 1 tick to assign mod_sig_coil
75 #define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
76
77 // When the PM acts as sniffer and is receiving tag data, it takes
78 // 3 ticks A/D conversion
79 // 14 ticks to complete the modulation detection
80 // 8 ticks (on average) until the result is stored in to_arm
81 // + the delays in transferring data - which is the same for
82 // sniffing reader and tag data and therefore not relevant
83 #define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
84
85 // When the PM acts as sniffer and is receiving reader data, it takes
86 // 2 ticks delay in analogue RF receiver (for the falling edge of the
87 // start bit, which marks the start of the communication)
88 // 3 ticks A/D conversion
89 // 8 ticks on average until the data is stored in to_arm.
90 // + the delays in transferring data - which is the same for
91 // sniffing reader and tag data and therefore not relevant
92 #define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
93
94 //variables used for timing purposes:
95 //these are in ssp_clk cycles:
96 static uint32_t NextTransferTime;
97 static uint32_t LastTimeProxToAirStart;
98 static uint32_t LastProxToAirDuration;
99
100 // CARD TO READER - manchester
101 // Sequence D: 11110000 modulation with subcarrier during first half
102 // Sequence E: 00001111 modulation with subcarrier during second half
103 // Sequence F: 00000000 no modulation with subcarrier
104 // READER TO CARD - miller
105 // Sequence X: 00001100 drop after half a period
106 // Sequence Y: 00000000 no drop
107 // Sequence Z: 11000000 drop at start
108 #define SEC_D 0xf0
109 #define SEC_E 0x0f
110 #define SEC_F 0x00
111 #define SEC_X 0x0c
112 #define SEC_Y 0x00
113 #define SEC_Z 0xc0
114
115 void iso14a_set_trigger(bool enable) {
116 trigger = enable;
117 }
118
119 void iso14a_set_timeout(uint32_t timeout) {
120 iso14a_timeout = timeout;
121 if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
122 }
123
124 void iso14a_set_ATS_timeout(uint8_t *ats) {
125 uint8_t tb1;
126 uint8_t fwi;
127 uint32_t fwt;
128
129 if (ats[0] > 1) { // there is a format byte T0
130 if ((ats[1] & 0x20) == 0x20) { // there is an interface byte TB(1)
131
132 if ((ats[1] & 0x10) == 0x10) // there is an interface byte TA(1) preceding TB(1)
133 tb1 = ats[3];
134 else
135 tb1 = ats[2];
136
137 fwi = (tb1 & 0xf0) >> 4; // frame waiting indicator (FWI)
138 fwt = 256 * 16 * (1 << fwi); // frame waiting time (FWT) in 1/fc
139 //fwt = 4096 * (1 << fwi);
140
141 iso14a_set_timeout(fwt/(8*16));
142 //iso14a_set_timeout(fwt/128);
143 }
144 }
145 }
146
147 //-----------------------------------------------------------------------------
148 // Generate the parity value for a byte sequence
149 //
150 //-----------------------------------------------------------------------------
151 void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par) {
152 uint16_t paritybit_cnt = 0;
153 uint16_t paritybyte_cnt = 0;
154 uint8_t parityBits = 0;
155
156 for (uint16_t i = 0; i < iLen; i++) {
157 // Generate the parity bits
158 parityBits |= ((oddparity8(pbtCmd[i])) << (7-paritybit_cnt));
159 if (paritybit_cnt == 7) {
160 par[paritybyte_cnt] = parityBits; // save 8 Bits parity
161 parityBits = 0; // and advance to next Parity Byte
162 paritybyte_cnt++;
163 paritybit_cnt = 0;
164 } else {
165 paritybit_cnt++;
166 }
167 }
168
169 // save remaining parity bits
170 par[paritybyte_cnt] = parityBits;
171 }
172
173 void AppendCrc14443a(uint8_t* data, int len) {
174 ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
175 }
176
177 //=============================================================================
178 // ISO 14443 Type A - Miller decoder
179 //=============================================================================
180 // Basics:
181 // This decoder is used when the PM3 acts as a tag.
182 // The reader will generate "pauses" by temporarily switching of the field.
183 // At the PM3 antenna we will therefore measure a modulated antenna voltage.
184 // The FPGA does a comparison with a threshold and would deliver e.g.:
185 // ........ 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 .......
186 // The Miller decoder needs to identify the following sequences:
187 // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0")
188 // 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information")
189 // 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1")
190 // Note 1: the bitstream may start at any time. We therefore need to sync.
191 // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
192 //-----------------------------------------------------------------------------
193 static tUart Uart;
194
195 // Lookup-Table to decide if 4 raw bits are a modulation.
196 // We accept the following:
197 // 0001 - a 3 tick wide pause
198 // 0011 - a 2 tick wide pause, or a three tick wide pause shifted left
199 // 0111 - a 2 tick wide pause shifted left
200 // 1001 - a 2 tick wide pause shifted right
201 const bool Mod_Miller_LUT[] = {
202 FALSE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, TRUE,
203 FALSE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
204 };
205 #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4])
206 #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)])
207
208 void UartReset() {
209 Uart.state = STATE_UNSYNCD;
210 Uart.bitCount = 0;
211 Uart.len = 0; // number of decoded data bytes
212 Uart.parityLen = 0; // number of decoded parity bytes
213 Uart.shiftReg = 0; // shiftreg to hold decoded data bits
214 Uart.parityBits = 0; // holds 8 parity bits
215 Uart.startTime = 0;
216 Uart.endTime = 0;
217
218 Uart.byteCntMax = 0;
219 Uart.posCnt = 0;
220 Uart.syncBit = 9999;
221 }
222
223 void UartInit(uint8_t *data, uint8_t *parity) {
224 Uart.output = data;
225 Uart.parity = parity;
226 Uart.fourBits = 0x00000000; // clear the buffer for 4 Bits
227 UartReset();
228 }
229
230 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
231 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time) {
232 Uart.fourBits = (Uart.fourBits << 8) | bit;
233
234 if (Uart.state == STATE_UNSYNCD) { // not yet synced
235 Uart.syncBit = 9999; // not set
236
237 // 00x11111 2|3 ticks pause followed by 6|5 ticks unmodulated Sequence Z (a "0" or "start of communication")
238 // 11111111 8 ticks unmodulation Sequence Y (a "0" or "end of communication" or "no information")
239 // 111100x1 4 ticks unmodulated followed by 2|3 ticks pause Sequence X (a "1")
240
241 // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from
242 // Sequence X followed by Sequence Y followed by Sequence Z (111100x1 11111111 00x11111)
243 // we therefore look for a ...xx1111 11111111 00x11111xxxxxx... pattern
244 // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's)
245 //
246 #define ISO14443A_STARTBIT_MASK 0x07FFEF80 // mask is 00001111 11111111 1110 1111 10000000
247 #define ISO14443A_STARTBIT_PATTERN 0x07FF8F80 // pattern is 00001111 11111111 1000 1111 10000000
248
249 if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7;
250 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6;
251 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5;
252 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4;
253 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3;
254 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2;
255 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1;
256 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0;
257
258 if (Uart.syncBit != 9999) { // found a sync bit
259 Uart.startTime = non_real_time ? non_real_time : (GetCountSspClk() & 0xfffffff8);
260 Uart.startTime -= Uart.syncBit;
261 Uart.endTime = Uart.startTime;
262 Uart.state = STATE_START_OF_COMMUNICATION;
263 }
264 } else {
265
266 if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) {
267 if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation in both halves - error
268 UartReset();
269 } else { // Modulation in first half = Sequence Z = logic "0"
270 if (Uart.state == STATE_MILLER_X) { // error - must not follow after X
271 UartReset();
272 } else {
273 Uart.bitCount++;
274 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
275 Uart.state = STATE_MILLER_Z;
276 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
277 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
278 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
279 Uart.parityBits <<= 1; // make room for the parity bit
280 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
281 Uart.bitCount = 0;
282 Uart.shiftReg = 0;
283 if((Uart.len&0x0007) == 0) { // every 8 data bytes
284 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
285 Uart.parityBits = 0;
286 }
287 }
288 }
289 }
290 } else {
291 if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1"
292 Uart.bitCount++;
293 Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg
294 Uart.state = STATE_MILLER_X;
295 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
296 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
297 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
298 Uart.parityBits <<= 1; // make room for the new parity bit
299 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
300 Uart.bitCount = 0;
301 Uart.shiftReg = 0;
302 if ((Uart.len&0x0007) == 0) { // every 8 data bytes
303 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
304 Uart.parityBits = 0;
305 }
306 }
307 } else { // no modulation in both halves - Sequence Y
308 if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication
309 Uart.state = STATE_UNSYNCD;
310 Uart.bitCount--; // last "0" was part of EOC sequence
311 Uart.shiftReg <<= 1; // drop it
312 if(Uart.bitCount > 0) { // if we decoded some bits
313 Uart.shiftReg >>= (9 - Uart.bitCount); // right align them
314 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); // add last byte to the output
315 Uart.parityBits <<= 1; // add a (void) parity bit
316 Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align parity bits
317 Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store it
318 return TRUE;
319 } else if (Uart.len & 0x0007) { // there are some parity bits to store
320 Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align remaining parity bits
321 Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store them
322 }
323 if (Uart.len) {
324 return TRUE; // we are finished with decoding the raw data sequence
325 } else {
326 UartReset(); // Nothing received - start over
327 }
328 }
329 if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC
330 UartReset();
331 } else { // a logic "0"
332 Uart.bitCount++;
333 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
334 Uart.state = STATE_MILLER_Y;
335 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
336 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
337 Uart.parityBits <<= 1; // make room for the parity bit
338 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
339 Uart.bitCount = 0;
340 Uart.shiftReg = 0;
341 if ((Uart.len&0x0007) == 0) { // every 8 data bytes
342 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
343 Uart.parityBits = 0;
344 }
345 }
346 }
347 }
348 }
349 }
350 return FALSE; // not finished yet, need more data
351 }
352
353 //=============================================================================
354 // ISO 14443 Type A - Manchester decoder
355 //=============================================================================
356 // Basics:
357 // This decoder is used when the PM3 acts as a reader.
358 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
359 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
360 // ........ 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 .......
361 // The Manchester decoder needs to identify the following sequences:
362 // 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication")
363 // 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0
364 // 8 ticks unmodulated: Sequence F = end of communication
365 // 8 ticks modulated: A collision. Save the collision position and treat as Sequence D
366 // Note 1: the bitstream may start at any time. We therefore need to sync.
367 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
368 static tDemod Demod;
369
370 // Lookup-Table to decide if 4 raw bits are a modulation.
371 // We accept three or four "1" in any position
372 const bool Mod_Manchester_LUT[] = {
373 FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
374 FALSE, FALSE, FALSE, TRUE, FALSE, TRUE, TRUE, TRUE
375 };
376
377 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
378 #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
379
380 void DemodReset() {
381 Demod.state = DEMOD_UNSYNCD;
382 Demod.len = 0; // number of decoded data bytes
383 Demod.parityLen = 0;
384 Demod.shiftReg = 0; // shiftreg to hold decoded data bits
385 Demod.parityBits = 0; //
386 Demod.collisionPos = 0; // Position of collision bit
387 Demod.twoBits = 0xffff; // buffer for 2 Bits
388 Demod.highCnt = 0;
389 Demod.startTime = 0;
390 Demod.endTime = 0;
391 Demod.bitCount = 0;
392 Demod.syncBit = 0xFFFF;
393 Demod.samples = 0;
394 }
395
396 void DemodInit(uint8_t *data, uint8_t *parity) {
397 Demod.output = data;
398 Demod.parity = parity;
399 DemodReset();
400 }
401
402 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
403 static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time) {
404 Demod.twoBits = (Demod.twoBits << 8) | bit;
405
406 if (Demod.state == DEMOD_UNSYNCD) {
407
408 if (Demod.highCnt < 2) { // wait for a stable unmodulated signal
409 if (Demod.twoBits == 0x0000) {
410 Demod.highCnt++;
411 } else {
412 Demod.highCnt = 0;
413 }
414 } else {
415 Demod.syncBit = 0xFFFF; // not set
416 if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
417 else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
418 else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
419 else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
420 else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
421 else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
422 else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
423 else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
424 if (Demod.syncBit != 0xFFFF) {
425 Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
426 Demod.startTime -= Demod.syncBit;
427 Demod.bitCount = offset; // number of decoded data bits
428 Demod.state = DEMOD_MANCHESTER_DATA;
429 }
430 }
431 } else {
432
433 if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half
434 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... and in second half = collision
435 if (!Demod.collisionPos) {
436 Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
437 }
438 } // modulation in first half only - Sequence D = 1
439 Demod.bitCount++;
440 Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg
441 if(Demod.bitCount == 9) { // if we decoded a full byte (including parity)
442 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
443 Demod.parityBits <<= 1; // make room for the parity bit
444 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
445 Demod.bitCount = 0;
446 Demod.shiftReg = 0;
447 if((Demod.len&0x0007) == 0) { // every 8 data bytes
448 Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits
449 Demod.parityBits = 0;
450 }
451 }
452 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
453 } else { // no modulation in first half
454 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // and modulation in second half = Sequence E = 0
455 Demod.bitCount++;
456 Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg
457 if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity)
458 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
459 Demod.parityBits <<= 1; // make room for the new parity bit
460 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
461 Demod.bitCount = 0;
462 Demod.shiftReg = 0;
463 if ((Demod.len&0x0007) == 0) { // every 8 data bytes
464 Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits1
465 Demod.parityBits = 0;
466 }
467 }
468 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
469 } else { // no modulation in both halves - End of communication
470 if(Demod.bitCount > 0) { // there are some remaining data bits
471 Demod.shiftReg >>= (9 - Demod.bitCount); // right align the decoded bits
472 Demod.output[Demod.len++] = Demod.shiftReg & 0xff; // and add them to the output
473 Demod.parityBits <<= 1; // add a (void) parity bit
474 Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
475 Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
476 return TRUE;
477 } else if (Demod.len & 0x0007) { // there are some parity bits to store
478 Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
479 Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
480 }
481 if (Demod.len) {
482 return TRUE; // we are finished with decoding the raw data sequence
483 } else { // nothing received. Start over
484 DemodReset();
485 }
486 }
487 }
488 }
489 return FALSE; // not finished yet, need more data
490 }
491
492 //=============================================================================
493 // Finally, a `sniffer' for ISO 14443 Type A
494 // Both sides of communication!
495 //=============================================================================
496
497 //-----------------------------------------------------------------------------
498 // Record the sequence of commands sent by the reader to the tag, with
499 // triggering so that we start recording at the point that the tag is moved
500 // near the reader.
501 // "hf 14a sniff"
502 //-----------------------------------------------------------------------------
503 void RAMFUNC SniffIso14443a(uint8_t param) {
504 // param:
505 // bit 0 - trigger from first card answer
506 // bit 1 - trigger from first reader 7-bit request
507 LEDsoff();
508
509 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
510
511 // Allocate memory from BigBuf for some buffers
512 // free all previous allocations first
513 BigBuf_free(); BigBuf_Clear_ext(false);
514 clear_trace();
515 set_tracing(TRUE);
516
517 // The command (reader -> tag) that we're receiving.
518 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
519 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
520
521 // The response (tag -> reader) that we're receiving.
522 uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
523 uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE);
524
525 // The DMA buffer, used to stream samples from the FPGA
526 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
527
528 uint8_t *data = dmaBuf;
529 uint8_t previous_data = 0;
530 int maxDataLen = 0;
531 int dataLen = 0;
532 bool TagIsActive = FALSE;
533 bool ReaderIsActive = FALSE;
534
535 // Set up the demodulator for tag -> reader responses.
536 DemodInit(receivedResponse, receivedResponsePar);
537
538 // Set up the demodulator for the reader -> tag commands
539 UartInit(receivedCmd, receivedCmdPar);
540
541 // Setup and start DMA.
542 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, DMA_BUFFER_SIZE) ){
543 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
544 return;
545 }
546
547 // We won't start recording the frames that we acquire until we trigger;
548 // a good trigger condition to get started is probably when we see a
549 // response from the tag.
550 // triggered == FALSE -- to wait first for card
551 bool triggered = !(param & 0x03);
552
553 // And now we loop, receiving samples.
554 for(uint32_t rsamples = 0; TRUE; ) {
555
556 if(BUTTON_PRESS()) {
557 DbpString("cancelled by button");
558 break;
559 }
560
561 LED_A_ON();
562 WDT_HIT();
563
564 int register readBufDataP = data - dmaBuf;
565 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
566 if (readBufDataP <= dmaBufDataP){
567 dataLen = dmaBufDataP - readBufDataP;
568 } else {
569 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
570 }
571 // test for length of buffer
572 if(dataLen > maxDataLen) {
573 maxDataLen = dataLen;
574 if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
575 Dbprintf("blew circular buffer! dataLen=%d", dataLen);
576 break;
577 }
578 }
579 if(dataLen < 1) continue;
580
581 // primary buffer was stopped( <-- we lost data!
582 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
583 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
584 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
585 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
586 }
587 // secondary buffer sets as primary, secondary buffer was stopped
588 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
589 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
590 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
591 }
592
593 LED_A_OFF();
594
595 if (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder
596
597 if(!TagIsActive) { // no need to try decoding reader data if the tag is sending
598 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
599 if (MillerDecoding(readerdata, (rsamples-1)*4)) {
600 LED_C_ON();
601
602 // check - if there is a short 7bit request from reader
603 if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
604
605 if(triggered) {
606 if (!LogTrace(receivedCmd,
607 Uart.len,
608 Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
609 Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
610 Uart.parity,
611 TRUE)) break;
612 }
613 /* And ready to receive another command. */
614 UartReset();
615 /* And also reset the demod code, which might have been */
616 /* false-triggered by the commands from the reader. */
617 DemodReset();
618 LED_B_OFF();
619 }
620 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
621 }
622
623 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time
624 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
625 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
626 LED_B_ON();
627
628 if (!LogTrace(receivedResponse,
629 Demod.len,
630 Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
631 Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
632 Demod.parity,
633 FALSE)) break;
634
635 if ((!triggered) && (param & 0x01)) triggered = TRUE;
636
637 // And ready to receive another response.
638 DemodReset();
639 // And reset the Miller decoder including itS (now outdated) input buffer
640 UartInit(receivedCmd, receivedCmdPar);
641 LED_C_OFF();
642 }
643 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
644 }
645 }
646
647 previous_data = *data;
648 rsamples++;
649 data++;
650 if(data == dmaBuf + DMA_BUFFER_SIZE) {
651 data = dmaBuf;
652 }
653 } // main cycle
654
655 if (MF_DBGLEVEL >= 1) {
656 Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
657 Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
658 }
659 FpgaDisableSscDma();
660 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
661 LEDsoff();
662 set_tracing(FALSE);
663 }
664
665 //-----------------------------------------------------------------------------
666 // Prepare tag messages
667 //-----------------------------------------------------------------------------
668 static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity) {
669 ToSendReset();
670
671 // Correction bit, might be removed when not needed
672 ToSendStuffBit(0);
673 ToSendStuffBit(0);
674 ToSendStuffBit(0);
675 ToSendStuffBit(0);
676 ToSendStuffBit(1); // 1
677 ToSendStuffBit(0);
678 ToSendStuffBit(0);
679 ToSendStuffBit(0);
680
681 // Send startbit
682 ToSend[++ToSendMax] = SEC_D;
683 LastProxToAirDuration = 8 * ToSendMax - 4;
684
685 for(uint16_t i = 0; i < len; i++) {
686 uint8_t b = cmd[i];
687
688 // Data bits
689 for(uint16_t j = 0; j < 8; j++) {
690 if(b & 1) {
691 ToSend[++ToSendMax] = SEC_D;
692 } else {
693 ToSend[++ToSendMax] = SEC_E;
694 }
695 b >>= 1;
696 }
697
698 // Get the parity bit
699 if (parity[i>>3] & (0x80>>(i&0x0007))) {
700 ToSend[++ToSendMax] = SEC_D;
701 LastProxToAirDuration = 8 * ToSendMax - 4;
702 } else {
703 ToSend[++ToSendMax] = SEC_E;
704 LastProxToAirDuration = 8 * ToSendMax;
705 }
706 }
707
708 // Send stopbit
709 ToSend[++ToSendMax] = SEC_F;
710
711 // Convert from last byte pos to length
712 ++ToSendMax;
713 }
714
715 static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len) {
716 uint8_t par[MAX_PARITY_SIZE] = {0};
717 GetParity(cmd, len, par);
718 CodeIso14443aAsTagPar(cmd, len, par);
719 }
720
721 static void Code4bitAnswerAsTag(uint8_t cmd) {
722 uint8_t b = cmd;
723
724 ToSendReset();
725
726 // Correction bit, might be removed when not needed
727 ToSendStuffBit(0);
728 ToSendStuffBit(0);
729 ToSendStuffBit(0);
730 ToSendStuffBit(0);
731 ToSendStuffBit(1); // 1
732 ToSendStuffBit(0);
733 ToSendStuffBit(0);
734 ToSendStuffBit(0);
735
736 // Send startbit
737 ToSend[++ToSendMax] = SEC_D;
738
739 for(uint8_t i = 0; i < 4; i++) {
740 if(b & 1) {
741 ToSend[++ToSendMax] = SEC_D;
742 LastProxToAirDuration = 8 * ToSendMax - 4;
743 } else {
744 ToSend[++ToSendMax] = SEC_E;
745 LastProxToAirDuration = 8 * ToSendMax;
746 }
747 b >>= 1;
748 }
749
750 // Send stopbit
751 ToSend[++ToSendMax] = SEC_F;
752
753 // Convert from last byte pos to length
754 ToSendMax++;
755 }
756
757 //-----------------------------------------------------------------------------
758 // Wait for commands from reader
759 // Stop when button is pressed
760 // Or return TRUE when command is captured
761 //-----------------------------------------------------------------------------
762 static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len) {
763 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
764 // only, since we are receiving, not transmitting).
765 // Signal field is off with the appropriate LED
766 LED_D_OFF();
767 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
768
769 // Now run a `software UART` on the stream of incoming samples.
770 UartInit(received, parity);
771
772 // clear RXRDY:
773 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
774
775 for(;;) {
776 WDT_HIT();
777
778 if(BUTTON_PRESS()) return FALSE;
779
780 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
781 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
782 if(MillerDecoding(b, 0)) {
783 *len = Uart.len;
784 return TRUE;
785 }
786 }
787 }
788 }
789
790 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
791 // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
792 // This will need the following byte array for a modulation sequence
793 // 144 data bits (18 * 8)
794 // 18 parity bits
795 // 2 Start and stop
796 // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA)
797 // 1 just for the case
798 // ----------- +
799 // 166 bytes, since every bit that needs to be send costs us a byte
800 //
801 // Prepare the tag modulation bits from the message
802 CodeIso14443aAsTag(response_info->response,response_info->response_n);
803
804 // Make sure we do not exceed the free buffer space
805 if (ToSendMax > max_buffer_size) {
806 Dbprintf("Out of memory, when modulating bits for tag answer:");
807 Dbhexdump(response_info->response_n,response_info->response,false);
808 return FALSE;
809 }
810
811 // Copy the byte array, used for this modulation to the buffer position
812 memcpy(response_info->modulation,ToSend,ToSendMax);
813
814 // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
815 response_info->modulation_n = ToSendMax;
816 response_info->ProxToAirDuration = LastProxToAirDuration;
817 return TRUE;
818 }
819
820 // "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit.
821 // Coded responses need one byte per bit to transfer (data, parity, start, stop, correction)
822 // 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits
823 // -> need 273 bytes buffer
824 // 44 * 8 data bits, 44 * 1 parity bits, 9 start bits, 9 stop bits, 9 correction bits --370
825 // 47 * 8 data bits, 47 * 1 parity bits, 10 start bits, 10 stop bits, 10 correction bits
826 #define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 453
827
828 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
829 // Retrieve and store the current buffer index
830 response_info->modulation = free_buffer_pointer;
831
832 // Determine the maximum size we can use from our buffer
833 size_t max_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE;
834
835 // Forward the prepare tag modulation function to the inner function
836 if (prepare_tag_modulation(response_info, max_buffer_size)) {
837 // Update the free buffer offset
838 free_buffer_pointer += ToSendMax;
839 return true;
840 } else {
841 return false;
842 }
843 }
844
845 //-----------------------------------------------------------------------------
846 // Main loop of simulated tag: receive commands from reader, decide what
847 // response to send, and send it.
848 // 'hf 14a sim'
849 //-----------------------------------------------------------------------------
850 void SimulateIso14443aTag(int tagType, int flags, byte_t* data) {
851
852 #define ATTACK_KEY_COUNT 8 // keep same as define in cmdhfmf.c -> readerAttack()
853 // init pseudorand
854 fast_prand();
855
856 uint8_t sak = 0;
857 uint32_t cuid = 0;
858 uint32_t nonce = 0;
859
860 // PACK response to PWD AUTH for EV1/NTAG
861 uint8_t response8[4] = {0,0,0,0};
862 // Counter for EV1/NTAG
863 uint32_t counters[] = {0,0,0};
864
865 // The first response contains the ATQA (note: bytes are transmitted in reverse order).
866 uint8_t response1[] = {0,0};
867
868 // Here, we collect CUID, block1, keytype1, NT1, NR1, AR1, CUID, block2, keytyp2, NT2, NR2, AR2
869 // it should also collect block, keytype.
870 uint8_t cardAUTHSC = 0;
871 uint8_t cardAUTHKEY = 0xff; // no authentication
872 // allow collecting up to 8 sets of nonces to allow recovery of up to 8 keys
873
874 nonces_t ar_nr_nonces[ATTACK_KEY_COUNT]; // for attack types moebius
875 memset(ar_nr_nonces, 0x00, sizeof(ar_nr_nonces));
876 uint8_t moebius_count = 0;
877
878 switch (tagType) {
879 case 1: { // MIFARE Classic 1k
880 response1[0] = 0x04;
881 sak = 0x08;
882 } break;
883 case 2: { // MIFARE Ultralight
884 response1[0] = 0x44;
885 sak = 0x00;
886 } break;
887 case 3: { // MIFARE DESFire
888 response1[0] = 0x04;
889 response1[1] = 0x03;
890 sak = 0x20;
891 } break;
892 case 4: { // ISO/IEC 14443-4 - javacard (JCOP)
893 response1[0] = 0x04;
894 sak = 0x28;
895 } break;
896 case 5: { // MIFARE TNP3XXX
897 response1[0] = 0x01;
898 response1[1] = 0x0f;
899 sak = 0x01;
900 } break;
901 case 6: { // MIFARE Mini 320b
902 response1[0] = 0x44;
903 sak = 0x09;
904 } break;
905 case 7: { // NTAG
906 response1[0] = 0x44;
907 sak = 0x00;
908 // PACK
909 response8[0] = 0x80;
910 response8[1] = 0x80;
911 ComputeCrc14443(CRC_14443_A, response8, 2, &response8[2], &response8[3]);
912 // uid not supplied then get from emulator memory
913 if (data[0]==0) {
914 uint16_t start = 4 * (0+12);
915 uint8_t emdata[8];
916 emlGetMemBt( emdata, start, sizeof(emdata));
917 memcpy(data, emdata, 3); // uid bytes 0-2
918 memcpy(data+3, emdata+4, 4); // uid bytes 3-7
919 flags |= FLAG_7B_UID_IN_DATA;
920 }
921 } break;
922 case 8: { // MIFARE Classic 4k
923 response1[0] = 0x02;
924 sak = 0x18;
925 } break;
926 default: {
927 Dbprintf("Error: unkown tagtype (%d)",tagType);
928 return;
929 } break;
930 }
931
932 // The second response contains the (mandatory) first 24 bits of the UID
933 uint8_t response2[5] = {0x00};
934
935 // For UID size 7,
936 uint8_t response2a[5] = {0x00};
937
938 if ( (flags & FLAG_7B_UID_IN_DATA) == FLAG_7B_UID_IN_DATA ) {
939 response2[0] = 0x88; // Cascade Tag marker
940 response2[1] = data[0];
941 response2[2] = data[1];
942 response2[3] = data[2];
943
944 response2a[0] = data[3];
945 response2a[1] = data[4];
946 response2a[2] = data[5];
947 response2a[3] = data[6]; //??
948 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
949
950 // Configure the ATQA and SAK accordingly
951 response1[0] |= 0x40;
952 sak |= 0x04;
953
954 cuid = bytes_to_num(data+3, 4);
955 } else {
956 memcpy(response2, data, 4);
957 // Configure the ATQA and SAK accordingly
958 response1[0] &= 0xBF;
959 sak &= 0xFB;
960 cuid = bytes_to_num(data, 4);
961 }
962
963 // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
964 response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
965
966 // Prepare the mandatory SAK (for 4 and 7 byte UID)
967 uint8_t response3[3] = {sak, 0x00, 0x00};
968 ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
969
970 // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
971 uint8_t response3a[3] = {0x00};
972 response3a[0] = sak & 0xFB;
973 ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
974
975 // Tag NONCE.
976 uint8_t response5[4];
977
978 uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS:
979 // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
980 // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
981 // TB(1) = not present. Defaults: FWI = 4 (FWT = 256 * 16 * 2^4 * 1/fc = 4833us), SFGI = 0 (SFG = 256 * 16 * 2^0 * 1/fc = 302us)
982 // TC(1) = 0x02: CID supported, NAD not supported
983 ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
984
985 // Prepare GET_VERSION (different for UL EV-1 / NTAG)
986 // uint8_t response7_EV1[] = {0x00, 0x04, 0x03, 0x01, 0x01, 0x00, 0x0b, 0x03, 0xfd, 0xf7}; //EV1 48bytes VERSION.
987 // uint8_t response7_NTAG[] = {0x00, 0x04, 0x04, 0x02, 0x01, 0x00, 0x11, 0x03, 0x01, 0x9e}; //NTAG 215
988 // Prepare CHK_TEARING
989 // uint8_t response9[] = {0xBD,0x90,0x3f};
990
991 #define TAG_RESPONSE_COUNT 10
992 tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
993 { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type
994 { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid
995 { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked
996 { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1
997 { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2
998 { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce)
999 { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS
1000
1001 { .response = response8, .response_n = sizeof(response8) } // EV1/NTAG PACK response
1002 };
1003 // { .response = response7_NTAG, .response_n = sizeof(response7_NTAG)}, // EV1/NTAG GET_VERSION response
1004 // { .response = response9, .response_n = sizeof(response9) } // EV1/NTAG CHK_TEAR response
1005
1006
1007 // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
1008 // Such a response is less time critical, so we can prepare them on the fly
1009 #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
1010 #define DYNAMIC_MODULATION_BUFFER_SIZE 512
1011 uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
1012 uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
1013 tag_response_info_t dynamic_response_info = {
1014 .response = dynamic_response_buffer,
1015 .response_n = 0,
1016 .modulation = dynamic_modulation_buffer,
1017 .modulation_n = 0
1018 };
1019
1020 // We need to listen to the high-frequency, peak-detected path.
1021 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1022
1023 BigBuf_free_keep_EM();
1024 clear_trace();
1025 set_tracing(TRUE);
1026
1027 // allocate buffers:
1028 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
1029 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
1030 free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
1031
1032 // Prepare the responses of the anticollision phase
1033 // there will be not enough time to do this at the moment the reader sends it REQA
1034 for (size_t i=0; i<TAG_RESPONSE_COUNT; i++)
1035 prepare_allocated_tag_modulation(&responses[i]);
1036
1037 int len = 0;
1038
1039 // To control where we are in the protocol
1040 int order = 0;
1041 int lastorder;
1042
1043 // Just to allow some checks
1044 int happened = 0;
1045 int happened2 = 0;
1046 int cmdsRecvd = 0;
1047 tag_response_info_t* p_response;
1048
1049 LED_A_ON();
1050 for(;;) {
1051 WDT_HIT();
1052
1053 // Clean receive command buffer
1054 if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
1055 Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen());
1056 break;
1057 }
1058 p_response = NULL;
1059
1060 // Okay, look at the command now.
1061 lastorder = order;
1062 if(receivedCmd[0] == ISO14443A_CMD_REQA) { // Received a REQUEST
1063 p_response = &responses[0]; order = 1;
1064 } else if(receivedCmd[0] == ISO14443A_CMD_WUPA) { // Received a WAKEUP
1065 p_response = &responses[0]; order = 6;
1066 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT) { // Received request for UID (cascade 1)
1067 p_response = &responses[1]; order = 2;
1068 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2) { // Received request for UID (cascade 2)
1069 p_response = &responses[2]; order = 20;
1070 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT) { // Received a SELECT (cascade 1)
1071 p_response = &responses[3]; order = 3;
1072 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2) { // Received a SELECT (cascade 2)
1073 p_response = &responses[4]; order = 30;
1074 } else if(receivedCmd[0] == ISO14443A_CMD_READBLOCK) { // Received a (plain) READ
1075 uint8_t block = receivedCmd[1];
1076 // if Ultralight or NTAG (4 byte blocks)
1077 if ( tagType == 7 || tagType == 2 ) {
1078 // first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1079 uint16_t start = 4 * (block+12);
1080 uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
1081 emlGetMemBt( emdata, start, 16);
1082 AppendCrc14443a(emdata, 16);
1083 EmSendCmdEx(emdata, sizeof(emdata), false);
1084 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1085 p_response = NULL;
1086 } else { // all other tags (16 byte block tags)
1087 uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
1088 emlGetMemBt( emdata, block, 16);
1089 AppendCrc14443a(emdata, 16);
1090 EmSendCmdEx(emdata, sizeof(emdata), false);
1091 // EmSendCmdEx(data+(4*receivedCmd[1]),16,false);
1092 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1093 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1094 p_response = NULL;
1095 }
1096 } else if(receivedCmd[0] == MIFARE_ULEV1_FASTREAD) { // Received a FAST READ (ranged read)
1097 uint8_t emdata[MAX_FRAME_SIZE];
1098 // first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1099 int start = (receivedCmd[1]+12) * 4;
1100 int len = (receivedCmd[2] - receivedCmd[1] + 1) * 4;
1101 emlGetMemBt( emdata, start, len);
1102 AppendCrc14443a(emdata, len);
1103 EmSendCmdEx(emdata, len+2, false);
1104 p_response = NULL;
1105 } else if(receivedCmd[0] == MIFARE_ULEV1_READSIG && tagType == 7) { // Received a READ SIGNATURE --
1106 // first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1107 uint16_t start = 4 * 4;
1108 uint8_t emdata[34];
1109 emlGetMemBt( emdata, start, 32);
1110 AppendCrc14443a(emdata, 32);
1111 EmSendCmdEx(emdata, sizeof(emdata), false);
1112 p_response = NULL;
1113 } else if (receivedCmd[0] == MIFARE_ULEV1_READ_CNT && tagType == 7) { // Received a READ COUNTER --
1114 uint8_t index = receivedCmd[1];
1115 uint8_t cmd[] = {0x00,0x00,0x00,0x14,0xa5};
1116 if ( counters[index] > 0) {
1117 num_to_bytes(counters[index], 3, cmd);
1118 AppendCrc14443a(cmd, sizeof(cmd)-2);
1119 }
1120 EmSendCmdEx(cmd,sizeof(cmd),false);
1121 p_response = NULL;
1122 } else if (receivedCmd[0] == MIFARE_ULEV1_INCR_CNT && tagType == 7) { // Received a INC COUNTER --
1123 // number of counter
1124 uint8_t counter = receivedCmd[1];
1125 uint32_t val = bytes_to_num(receivedCmd+2,4);
1126 counters[counter] = val;
1127
1128 // send ACK
1129 uint8_t ack[] = {0x0a};
1130 EmSendCmdEx(ack,sizeof(ack),false);
1131 p_response = NULL;
1132 } else if(receivedCmd[0] == MIFARE_ULEV1_CHECKTEAR && tagType == 7) { // Received a CHECK_TEARING_EVENT --
1133 // first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1134 uint8_t emdata[3];
1135 uint8_t counter=0;
1136 if (receivedCmd[1]<3) counter = receivedCmd[1];
1137 emlGetMemBt( emdata, 10+counter, 1);
1138 AppendCrc14443a(emdata, sizeof(emdata)-2);
1139 EmSendCmdEx(emdata, sizeof(emdata), false);
1140 p_response = NULL;
1141 } else if(receivedCmd[0] == ISO14443A_CMD_HALT) { // Received a HALT
1142 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1143 p_response = NULL;
1144 } else if(receivedCmd[0] == MIFARE_AUTH_KEYA || receivedCmd[0] == MIFARE_AUTH_KEYB) { // Received an authentication request
1145 if ( tagType == 7 ) { // IF NTAG /EV1 0x60 == GET_VERSION, not a authentication request.
1146 uint8_t emdata[10];
1147 emlGetMemBt( emdata, 0, 8 );
1148 AppendCrc14443a(emdata, sizeof(emdata)-2);
1149 EmSendCmdEx(emdata, sizeof(emdata), false);
1150 p_response = NULL;
1151 } else {
1152
1153 cardAUTHKEY = receivedCmd[0] - 0x60;
1154 cardAUTHSC = receivedCmd[1] / 4; // received block num
1155
1156 // incease nonce at AUTH requests. this is time consuming.
1157 nonce = prand();
1158 //num_to_bytes(nonce, 4, response5);
1159 num_to_bytes(nonce, 4, dynamic_response_info.response);
1160 dynamic_response_info.response_n = 4;
1161
1162 //prepare_tag_modulation(&responses[5], DYNAMIC_MODULATION_BUFFER_SIZE);
1163 prepare_tag_modulation(&dynamic_response_info, DYNAMIC_MODULATION_BUFFER_SIZE);
1164 p_response = &dynamic_response_info;
1165 //p_response = &responses[5];
1166 order = 7;
1167 }
1168 } else if(receivedCmd[0] == ISO14443A_CMD_RATS) { // Received a RATS request
1169 if (tagType == 1 || tagType == 2) { // RATS not supported
1170 EmSend4bit(CARD_NACK_NA);
1171 p_response = NULL;
1172 } else {
1173 p_response = &responses[6]; order = 70;
1174 }
1175 } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
1176 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1177 uint32_t nr = bytes_to_num(receivedCmd,4);
1178 uint32_t ar = bytes_to_num(receivedCmd+4,4);
1179
1180 // Collect AR/NR per keytype & sector
1181 if ( (flags & FLAG_NR_AR_ATTACK) == FLAG_NR_AR_ATTACK ) {
1182
1183 int8_t index = -1;
1184 int8_t empty = -1;
1185 for (uint8_t i = 0; i < ATTACK_KEY_COUNT; i++) {
1186 // find which index to use
1187 if ( (cardAUTHSC == ar_nr_nonces[i].sector) && (cardAUTHKEY == ar_nr_nonces[i].keytype))
1188 index = i;
1189
1190 // keep track of empty slots.
1191 if ( ar_nr_nonces[i].state == EMPTY)
1192 empty = i;
1193 }
1194 // if no empty slots. Choose first and overwrite.
1195 if ( index == -1 ) {
1196 if ( empty == -1 ) {
1197 index = 0;
1198 ar_nr_nonces[index].state = EMPTY;
1199 } else {
1200 index = empty;
1201 }
1202 }
1203
1204 switch(ar_nr_nonces[index].state) {
1205 case EMPTY: {
1206 // first nonce collect
1207 ar_nr_nonces[index].cuid = cuid;
1208 ar_nr_nonces[index].sector = cardAUTHSC;
1209 ar_nr_nonces[index].keytype = cardAUTHKEY;
1210 ar_nr_nonces[index].nonce = nonce;
1211 ar_nr_nonces[index].nr = nr;
1212 ar_nr_nonces[index].ar = ar;
1213 ar_nr_nonces[index].state = FIRST;
1214 break;
1215 }
1216 case FIRST : {
1217 // second nonce collect
1218 ar_nr_nonces[index].nonce2 = nonce;
1219 ar_nr_nonces[index].nr2 = nr;
1220 ar_nr_nonces[index].ar2 = ar;
1221 ar_nr_nonces[index].state = SECOND;
1222
1223 // send to client
1224 cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, 0, 0, &ar_nr_nonces[index], sizeof(nonces_t));
1225
1226 ar_nr_nonces[index].state = EMPTY;
1227 ar_nr_nonces[index].sector = 0;
1228 ar_nr_nonces[index].keytype = 0;
1229
1230 moebius_count++;
1231 break;
1232 }
1233 default: break;
1234 }
1235 }
1236 p_response = NULL;
1237
1238 } else if (receivedCmd[0] == MIFARE_ULC_AUTH_1 ) { // ULC authentication, or Desfire Authentication
1239 } else if (receivedCmd[0] == MIFARE_ULEV1_AUTH) { // NTAG / EV-1 authentication
1240 if ( tagType == 7 ) {
1241 uint16_t start = 13; // first 4 blocks of emu are [getversion answer - check tearing - pack - 0x00]
1242 uint8_t emdata[4];
1243 emlGetMemBt( emdata, start, 2);
1244 AppendCrc14443a(emdata, 2);
1245 EmSendCmdEx(emdata, sizeof(emdata), false);
1246 p_response = NULL;
1247 uint32_t pwd = bytes_to_num(receivedCmd+1,4);
1248
1249 if ( MF_DBGLEVEL >= 3) Dbprintf("Auth attempt: %08x", pwd);
1250 }
1251 } else {
1252 // Check for ISO 14443A-4 compliant commands, look at left nibble
1253 switch (receivedCmd[0]) {
1254 case 0x02:
1255 case 0x03: { // IBlock (command no CID)
1256 dynamic_response_info.response[0] = receivedCmd[0];
1257 dynamic_response_info.response[1] = 0x90;
1258 dynamic_response_info.response[2] = 0x00;
1259 dynamic_response_info.response_n = 3;
1260 } break;
1261 case 0x0B:
1262 case 0x0A: { // IBlock (command CID)
1263 dynamic_response_info.response[0] = receivedCmd[0];
1264 dynamic_response_info.response[1] = 0x00;
1265 dynamic_response_info.response[2] = 0x90;
1266 dynamic_response_info.response[3] = 0x00;
1267 dynamic_response_info.response_n = 4;
1268 } break;
1269
1270 case 0x1A:
1271 case 0x1B: { // Chaining command
1272 dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1273 dynamic_response_info.response_n = 2;
1274 } break;
1275
1276 case 0xAA:
1277 case 0xBB: {
1278 dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1279 dynamic_response_info.response_n = 2;
1280 } break;
1281
1282 case 0xBA: { // ping / pong
1283 dynamic_response_info.response[0] = 0xAB;
1284 dynamic_response_info.response[1] = 0x00;
1285 dynamic_response_info.response_n = 2;
1286 } break;
1287
1288 case 0xCA:
1289 case 0xC2: { // Readers sends deselect command
1290 dynamic_response_info.response[0] = 0xCA;
1291 dynamic_response_info.response[1] = 0x00;
1292 dynamic_response_info.response_n = 2;
1293 } break;
1294
1295 default: {
1296 // Never seen this command before
1297 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1298 Dbprintf("Received unknown command (len=%d):",len);
1299 Dbhexdump(len,receivedCmd,false);
1300 // Do not respond
1301 dynamic_response_info.response_n = 0;
1302 } break;
1303 }
1304
1305 if (dynamic_response_info.response_n > 0) {
1306 // Copy the CID from the reader query
1307 dynamic_response_info.response[1] = receivedCmd[1];
1308
1309 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1310 AppendCrc14443a(dynamic_response_info.response, dynamic_response_info.response_n);
1311 dynamic_response_info.response_n += 2;
1312
1313 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1314 DbpString("Error preparing tag response");
1315 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1316 break;
1317 }
1318 p_response = &dynamic_response_info;
1319 }
1320 }
1321
1322 // Count number of wakeups received after a halt
1323 if(order == 6 && lastorder == 5) { happened++; }
1324
1325 // Count number of other messages after a halt
1326 if(order != 6 && lastorder == 5) { happened2++; }
1327
1328 // comment this limit if you want to simulation longer
1329 if (!tracing) {
1330 DbpString("Trace Full. Simulation stopped.");
1331 break;
1332 }
1333 // comment this limit if you want to simulation longer
1334 if(cmdsRecvd > 999) {
1335 DbpString("1000 commands later...");
1336 break;
1337 }
1338 cmdsRecvd++;
1339
1340 if (p_response != NULL) {
1341 EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1342 // do the tracing for the previous reader request and this tag answer:
1343 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1344 GetParity(p_response->response, p_response->response_n, par);
1345
1346 EmLogTrace(Uart.output,
1347 Uart.len,
1348 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1349 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1350 Uart.parity,
1351 p_response->response,
1352 p_response->response_n,
1353 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1354 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1355 par);
1356 }
1357 }
1358
1359 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1360 set_tracing(FALSE);
1361 BigBuf_free_keep_EM();
1362 LED_A_OFF();
1363
1364 /*
1365 if(flags & FLAG_NR_AR_ATTACK && MF_DBGLEVEL >= 1) {
1366
1367 for ( uint8_t i = 0; i < ATTACK_KEY_COUNT; i++) {
1368 if (ar_nr_collected[i] == 2) {
1369 Dbprintf("Collected two pairs of AR/NR which can be used to extract %s from reader for sector %d:", (i<ATTACK_KEY_COUNT/2) ? "keyA" : "keyB", ar_nr_resp[i].sector);
1370 Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
1371 ar_nr_resp[i].cuid, //UID
1372 ar_nr_resp[i].nonce, //NT
1373 ar_nr_resp[i].nr, //NR1
1374 ar_nr_resp[i].ar, //AR1
1375 ar_nr_resp[i].nr2, //NR2
1376 ar_nr_resp[i].ar2 //AR2
1377 );
1378 }
1379 }
1380
1381 for ( uint8_t i = ATTACK_KEY_COUNT; i < ATTACK_KEY_COUNT*2; i++) {
1382 if (ar_nr_collected[i] == 2) {
1383 Dbprintf("Collected two pairs of AR/NR which can be used to extract %s from reader for sector %d:", (i<ATTACK_KEY_COUNT/2) ? "keyA" : "keyB", ar_nr_resp[i].sector);
1384 Dbprintf("../tools/mfkey/mfkey32v2 %08x %08x %08x %08x %08x %08x %08x",
1385 ar_nr_resp[i].cuid, //UID
1386 ar_nr_resp[i].nonce, //NT
1387 ar_nr_resp[i].nr, //NR1
1388 ar_nr_resp[i].ar, //AR1
1389 ar_nr_resp[i].nonce2,//NT2
1390 ar_nr_resp[i].nr2, //NR2
1391 ar_nr_resp[i].ar2 //AR2
1392 );
1393 }
1394 }
1395 }
1396 */
1397
1398 if (MF_DBGLEVEL >= 4){
1399 Dbprintf("-[ Wake ups after halt [%d]", happened);
1400 Dbprintf("-[ Messages after halt [%d]", happened2);
1401 Dbprintf("-[ Num of received cmd [%d]", cmdsRecvd);
1402 Dbprintf("-[ Num of moebius tries [%d]", moebius_count);
1403 }
1404
1405 cmd_send(CMD_ACK,1,0,0,0,0);
1406 }
1407
1408 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1409 // of bits specified in the delay parameter.
1410 void PrepareDelayedTransfer(uint16_t delay) {
1411 delay &= 0x07;
1412 if (!delay) return;
1413
1414 uint8_t bitmask = 0;
1415 uint8_t bits_to_shift = 0;
1416 uint8_t bits_shifted = 0;
1417 uint16_t i = 0;
1418
1419 for (i = 0; i < delay; ++i)
1420 bitmask |= (0x01 << i);
1421
1422 ToSend[++ToSendMax] = 0x00;
1423
1424 for (i = 0; i < ToSendMax; ++i) {
1425 bits_to_shift = ToSend[i] & bitmask;
1426 ToSend[i] = ToSend[i] >> delay;
1427 ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1428 bits_shifted = bits_to_shift;
1429 }
1430 }
1431
1432
1433 //-------------------------------------------------------------------------------------
1434 // Transmit the command (to the tag) that was placed in ToSend[].
1435 // Parameter timing:
1436 // if NULL: transfer at next possible time, taking into account
1437 // request guard time and frame delay time
1438 // if == 0: transfer immediately and return time of transfer
1439 // if != 0: delay transfer until time specified
1440 //-------------------------------------------------------------------------------------
1441 static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing) {
1442 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1443
1444 uint32_t ThisTransferTime = 0;
1445
1446 if (timing) {
1447 if(*timing == 0) { // Measure time
1448 *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1449 } else {
1450 PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
1451 }
1452 if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
1453 while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
1454 LastTimeProxToAirStart = *timing;
1455 } else {
1456 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1457
1458 while(GetCountSspClk() < ThisTransferTime);
1459
1460 LastTimeProxToAirStart = ThisTransferTime;
1461 }
1462
1463 // clear TXRDY
1464 AT91C_BASE_SSC->SSC_THR = SEC_Y;
1465
1466 uint16_t c = 0;
1467 for(;;) {
1468 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1469 AT91C_BASE_SSC->SSC_THR = cmd[c];
1470 ++c;
1471 if(c >= len)
1472 break;
1473 }
1474 }
1475
1476 NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1477 }
1478
1479 //-----------------------------------------------------------------------------
1480 // Prepare reader command (in bits, support short frames) to send to FPGA
1481 //-----------------------------------------------------------------------------
1482 void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity) {
1483 int i, j;
1484 int last = 0;
1485 uint8_t b;
1486
1487 ToSendReset();
1488
1489 // Start of Communication (Seq. Z)
1490 ToSend[++ToSendMax] = SEC_Z;
1491 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1492
1493 size_t bytecount = nbytes(bits);
1494 // Generate send structure for the data bits
1495 for (i = 0; i < bytecount; i++) {
1496 // Get the current byte to send
1497 b = cmd[i];
1498 size_t bitsleft = MIN((bits-(i*8)),8);
1499
1500 for (j = 0; j < bitsleft; j++) {
1501 if (b & 1) {
1502 // Sequence X
1503 ToSend[++ToSendMax] = SEC_X;
1504 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1505 last = 1;
1506 } else {
1507 if (last == 0) {
1508 // Sequence Z
1509 ToSend[++ToSendMax] = SEC_Z;
1510 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1511 } else {
1512 // Sequence Y
1513 ToSend[++ToSendMax] = SEC_Y;
1514 last = 0;
1515 }
1516 }
1517 b >>= 1;
1518 }
1519
1520 // Only transmit parity bit if we transmitted a complete byte
1521 if (j == 8 && parity != NULL) {
1522 // Get the parity bit
1523 if (parity[i>>3] & (0x80 >> (i&0x0007))) {
1524 // Sequence X
1525 ToSend[++ToSendMax] = SEC_X;
1526 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1527 last = 1;
1528 } else {
1529 if (last == 0) {
1530 // Sequence Z
1531 ToSend[++ToSendMax] = SEC_Z;
1532 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1533 } else {
1534 // Sequence Y
1535 ToSend[++ToSendMax] = SEC_Y;
1536 last = 0;
1537 }
1538 }
1539 }
1540 }
1541
1542 // End of Communication: Logic 0 followed by Sequence Y
1543 if (last == 0) {
1544 // Sequence Z
1545 ToSend[++ToSendMax] = SEC_Z;
1546 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1547 } else {
1548 // Sequence Y
1549 ToSend[++ToSendMax] = SEC_Y;
1550 last = 0;
1551 }
1552 ToSend[++ToSendMax] = SEC_Y;
1553
1554 // Convert to length of command:
1555 ++ToSendMax;
1556 }
1557
1558 //-----------------------------------------------------------------------------
1559 // Prepare reader command to send to FPGA
1560 //-----------------------------------------------------------------------------
1561 void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity) {
1562 CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
1563 }
1564
1565 //-----------------------------------------------------------------------------
1566 // Wait for commands from reader
1567 // Stop when button is pressed (return 1) or field was gone (return 2)
1568 // Or return 0 when command is captured
1569 //-----------------------------------------------------------------------------
1570 static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity) {
1571 *len = 0;
1572
1573 uint32_t timer = 0, vtime = 0;
1574 int analogCnt = 0;
1575 int analogAVG = 0;
1576
1577 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1578 // only, since we are receiving, not transmitting).
1579 // Signal field is off with the appropriate LED
1580 LED_D_OFF();
1581 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1582
1583 // Set ADC to read field strength
1584 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1585 AT91C_BASE_ADC->ADC_MR =
1586 ADC_MODE_PRESCALE(63) |
1587 ADC_MODE_STARTUP_TIME(1) |
1588 ADC_MODE_SAMPLE_HOLD_TIME(15);
1589 AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1590 // start ADC
1591 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1592
1593 // Now run a 'software UART' on the stream of incoming samples.
1594 UartInit(received, parity);
1595
1596 // Clear RXRDY:
1597 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1598
1599 for(;;) {
1600 WDT_HIT();
1601
1602 if (BUTTON_PRESS()) return 1;
1603
1604 // test if the field exists
1605 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1606 analogCnt++;
1607 analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1608 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1609 if (analogCnt >= 32) {
1610 if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1611 vtime = GetTickCount();
1612 if (!timer) timer = vtime;
1613 // 50ms no field --> card to idle state
1614 if (vtime - timer > 50) return 2;
1615 } else
1616 if (timer) timer = 0;
1617 analogCnt = 0;
1618 analogAVG = 0;
1619 }
1620 }
1621
1622 // receive and test the miller decoding
1623 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1624 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1625 if(MillerDecoding(b, 0)) {
1626 *len = Uart.len;
1627 return 0;
1628 }
1629 }
1630 }
1631 }
1632
1633 int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded) {
1634 uint8_t b;
1635 uint16_t i = 0;
1636 uint32_t ThisTransferTime;
1637
1638 // Modulate Manchester
1639 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1640
1641 // include correction bit if necessary
1642 if (Uart.parityBits & 0x01) {
1643 correctionNeeded = TRUE;
1644 }
1645 // 1236, so correction bit needed
1646 i = (correctionNeeded) ? 0 : 1;
1647
1648 // clear receiving shift register and holding register
1649 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1650 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1651 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1652 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1653
1654 // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1655 for (uint8_t j = 0; j < 5; j++) { // allow timeout - better late than never
1656 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1657 if (AT91C_BASE_SSC->SSC_RHR) break;
1658 }
1659
1660 while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1661
1662 // Clear TXRDY:
1663 AT91C_BASE_SSC->SSC_THR = SEC_F;
1664
1665 // send cycle
1666 for(; i < respLen; ) {
1667 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1668 AT91C_BASE_SSC->SSC_THR = resp[i++];
1669 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1670 }
1671
1672 if(BUTTON_PRESS()) break;
1673 }
1674
1675 // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1676 uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3; // twich /8 ?? >>3,
1677 for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
1678 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1679 AT91C_BASE_SSC->SSC_THR = SEC_F;
1680 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1681 i++;
1682 }
1683 }
1684 LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
1685 return 0;
1686 }
1687
1688 int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
1689 Code4bitAnswerAsTag(resp);
1690 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1691 // do the tracing for the previous reader request and this tag answer:
1692 uint8_t par[1] = {0x00};
1693 GetParity(&resp, 1, par);
1694 EmLogTrace(Uart.output,
1695 Uart.len,
1696 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1697 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1698 Uart.parity,
1699 &resp,
1700 1,
1701 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1702 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1703 par);
1704 return res;
1705 }
1706
1707 int EmSend4bit(uint8_t resp){
1708 return EmSend4bitEx(resp, false);
1709 }
1710
1711 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){
1712 CodeIso14443aAsTagPar(resp, respLen, par);
1713 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1714 // do the tracing for the previous reader request and this tag answer:
1715 EmLogTrace(Uart.output,
1716 Uart.len,
1717 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1718 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1719 Uart.parity,
1720 resp,
1721 respLen,
1722 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1723 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1724 par);
1725 return res;
1726 }
1727
1728 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){
1729 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1730 GetParity(resp, respLen, par);
1731 return EmSendCmdExPar(resp, respLen, correctionNeeded, par);
1732 }
1733
1734 int EmSendCmd(uint8_t *resp, uint16_t respLen){
1735 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1736 GetParity(resp, respLen, par);
1737 return EmSendCmdExPar(resp, respLen, false, par);
1738 }
1739
1740 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
1741 return EmSendCmdExPar(resp, respLen, false, par);
1742 }
1743
1744 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
1745 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity)
1746 {
1747 // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1748 // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1749 // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1750 uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1751 uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1752 uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1753 reader_EndTime = tag_StartTime - exact_fdt;
1754 reader_StartTime = reader_EndTime - reader_modlen;
1755
1756 if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE))
1757 return FALSE;
1758 else
1759 return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
1760
1761 }
1762
1763 //-----------------------------------------------------------------------------
1764 // Wait a certain time for tag response
1765 // If a response is captured return TRUE
1766 // If it takes too long return FALSE
1767 //-----------------------------------------------------------------------------
1768 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset) {
1769 uint32_t c = 0x00;
1770
1771 // Set FPGA mode to "reader listen mode", no modulation (listen
1772 // only, since we are receiving, not transmitting).
1773 // Signal field is on with the appropriate LED
1774 LED_D_ON();
1775 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1776
1777 // Now get the answer from the card
1778 DemodInit(receivedResponse, receivedResponsePar);
1779
1780 // clear RXRDY:
1781 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1782
1783 for(;;) {
1784 WDT_HIT();
1785
1786 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1787 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1788 if(ManchesterDecoding(b, offset, 0)) {
1789 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1790 return TRUE;
1791 } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
1792 return FALSE;
1793 }
1794 }
1795 }
1796 }
1797
1798 void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing) {
1799
1800 CodeIso14443aBitsAsReaderPar(frame, bits, par);
1801 // Send command to tag
1802 TransmitFor14443a(ToSend, ToSendMax, timing);
1803 if(trigger) LED_A_ON();
1804
1805 LogTrace(frame, nbytes(bits), (LastTimeProxToAirStart<<4) + DELAY_ARM2AIR_AS_READER, ((LastTimeProxToAirStart + LastProxToAirDuration)<<4) + DELAY_ARM2AIR_AS_READER, par, TRUE);
1806 }
1807
1808 void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing) {
1809 ReaderTransmitBitsPar(frame, len*8, par, timing);
1810 }
1811
1812 void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing) {
1813 // Generate parity and redirect
1814 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1815 GetParity(frame, len/8, par);
1816 ReaderTransmitBitsPar(frame, len, par, timing);
1817 }
1818
1819 void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing) {
1820 // Generate parity and redirect
1821 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1822 GetParity(frame, len, par);
1823 ReaderTransmitBitsPar(frame, len*8, par, timing);
1824 }
1825
1826 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity) {
1827 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset))
1828 return FALSE;
1829 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1830 return Demod.len;
1831 }
1832
1833 int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity) {
1834 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0))
1835 return FALSE;
1836 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1837 return Demod.len;
1838 }
1839
1840 // performs iso14443a anticollision (optional) and card select procedure
1841 // fills the uid and cuid pointer unless NULL
1842 // fills the card info record unless NULL
1843 // if anticollision is false, then the UID must be provided in uid_ptr[]
1844 // and num_cascades must be set (1: 4 Byte UID, 2: 7 Byte UID, 3: 10 Byte UID)
1845 int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr, bool anticollision, uint8_t num_cascades) {
1846 uint8_t wupa[] = { ISO14443A_CMD_WUPA }; // 0x26 - ISO14443A_CMD_REQA 0x52 - ISO14443A_CMD_WUPA
1847 uint8_t sel_all[] = { ISO14443A_CMD_ANTICOLL_OR_SELECT,0x20 };
1848 uint8_t sel_uid[] = { ISO14443A_CMD_ANTICOLL_OR_SELECT,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1849 uint8_t rats[] = { ISO14443A_CMD_RATS,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1850 uint8_t resp[MAX_FRAME_SIZE] = {0}; // theoretically. A usual RATS will be much smaller
1851 uint8_t resp_par[MAX_PARITY_SIZE] = {0};
1852 byte_t uid_resp[4] = {0};
1853 size_t uid_resp_len = 0;
1854
1855 uint8_t sak = 0x04; // cascade uid
1856 int cascade_level = 0;
1857 int len;
1858
1859 // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1860 ReaderTransmitBitsPar(wupa, 7, NULL, NULL);
1861
1862 // Receive the ATQA
1863 if(!ReaderReceive(resp, resp_par)) return 0;
1864
1865 if(p_hi14a_card) {
1866 memcpy(p_hi14a_card->atqa, resp, 2);
1867 p_hi14a_card->uidlen = 0;
1868 memset(p_hi14a_card->uid,0,10);
1869 }
1870
1871 if (anticollision) {
1872 // clear uid
1873 if (uid_ptr)
1874 memset(uid_ptr,0,10);
1875 }
1876
1877 // reset the PCB block number
1878 iso14_pcb_blocknum = 0;
1879
1880 // check for proprietary anticollision:
1881 if ((resp[0] & 0x1F) == 0) return 3;
1882
1883 // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1884 // which case we need to make a cascade 2 request and select - this is a long UID
1885 // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1886 for(; sak & 0x04; cascade_level++) {
1887 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1888 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1889
1890 if (anticollision) {
1891 // SELECT_ALL
1892 ReaderTransmit(sel_all, sizeof(sel_all), NULL);
1893 if (!ReaderReceive(resp, resp_par)) return 0;
1894
1895 if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit
1896 memset(uid_resp, 0, 4);
1897 uint16_t uid_resp_bits = 0;
1898 uint16_t collision_answer_offset = 0;
1899 // anti-collision-loop:
1900 while (Demod.collisionPos) {
1901 Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1902 for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point
1903 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1904 uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8);
1905 }
1906 uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position
1907 uid_resp_bits++;
1908 // construct anticollosion command:
1909 sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits
1910 for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1911 sel_uid[2+i] = uid_resp[i];
1912 }
1913 collision_answer_offset = uid_resp_bits%8;
1914 ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1915 if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0;
1916 }
1917 // finally, add the last bits and BCC of the UID
1918 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1919 uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1920 uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1921 }
1922
1923 } else { // no collision, use the response to SELECT_ALL as current uid
1924 memcpy(uid_resp, resp, 4);
1925 }
1926
1927 } else {
1928 if (cascade_level < num_cascades - 1) {
1929 uid_resp[0] = 0x88;
1930 memcpy(uid_resp+1, uid_ptr+cascade_level*3, 3);
1931 } else {
1932 memcpy(uid_resp, uid_ptr+cascade_level*3, 4);
1933 }
1934 }
1935 uid_resp_len = 4;
1936
1937 // calculate crypto UID. Always use last 4 Bytes.
1938 if(cuid_ptr)
1939 *cuid_ptr = bytes_to_num(uid_resp, 4);
1940
1941 // Construct SELECT UID command
1942 sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1943 memcpy(sel_uid+2, uid_resp, 4); // the UID received during anticollision, or the provided UID
1944 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC
1945 AppendCrc14443a(sel_uid, 7); // calculate and add CRC
1946 ReaderTransmit(sel_uid, sizeof(sel_uid), NULL);
1947
1948 // Receive the SAK
1949 if (!ReaderReceive(resp, resp_par)) return 0;
1950
1951 sak = resp[0];
1952
1953 // Test if more parts of the uid are coming
1954 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
1955 // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
1956 // http://www.nxp.com/documents/application_note/AN10927.pdf
1957 uid_resp[0] = uid_resp[1];
1958 uid_resp[1] = uid_resp[2];
1959 uid_resp[2] = uid_resp[3];
1960 uid_resp_len = 3;
1961 }
1962
1963 if(uid_ptr && anticollision)
1964 memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
1965
1966 if(p_hi14a_card) {
1967 memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
1968 p_hi14a_card->uidlen += uid_resp_len;
1969 }
1970 }
1971
1972 if(p_hi14a_card) {
1973 p_hi14a_card->sak = sak;
1974 p_hi14a_card->ats_len = 0;
1975 }
1976
1977 // non iso14443a compliant tag
1978 if( (sak & 0x20) == 0) return 2;
1979
1980 // Request for answer to select
1981 AppendCrc14443a(rats, 2);
1982 ReaderTransmit(rats, sizeof(rats), NULL);
1983
1984 if (!(len = ReaderReceive(resp, resp_par))) return 0;
1985
1986 if(p_hi14a_card) {
1987 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
1988 p_hi14a_card->ats_len = len;
1989 }
1990
1991 // set default timeout based on ATS
1992 iso14a_set_ATS_timeout(resp);
1993 return 1;
1994 }
1995
1996 void iso14443a_setup(uint8_t fpga_minor_mode) {
1997
1998 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1999 // Set up the synchronous serial port
2000 FpgaSetupSsc();
2001 // connect Demodulated Signal to ADC:
2002 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
2003
2004 LED_D_OFF();
2005 // Signal field is on with the appropriate LED
2006 if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD ||
2007 fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN)
2008 LED_D_ON();
2009
2010 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
2011
2012 SpinDelay(20);
2013
2014 // Start the timer
2015 StartCountSspClk();
2016
2017 // Prepare the demodulation functions
2018 DemodReset();
2019 UartReset();
2020 NextTransferTime = 2 * DELAY_ARM2AIR_AS_READER;
2021 iso14a_set_timeout(10*106); // 20ms default
2022 }
2023
2024 int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
2025 uint8_t parity[MAX_PARITY_SIZE] = {0x00};
2026 uint8_t real_cmd[cmd_len+4];
2027 real_cmd[0] = 0x0a; //I-Block
2028 // put block number into the PCB
2029 real_cmd[0] |= iso14_pcb_blocknum;
2030 real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
2031 memcpy(real_cmd+2, cmd, cmd_len);
2032 AppendCrc14443a(real_cmd,cmd_len+2);
2033
2034 ReaderTransmit(real_cmd, cmd_len+4, NULL);
2035 size_t len = ReaderReceive(data, parity);
2036 //DATA LINK ERROR
2037 if (!len) return 0;
2038
2039 uint8_t *data_bytes = (uint8_t *) data;
2040
2041 // if we received an I- or R(ACK)-Block with a block number equal to the
2042 // current block number, toggle the current block number
2043 if (len >= 4 // PCB+CID+CRC = 4 bytes
2044 && ((data_bytes[0] & 0xC0) == 0 // I-Block
2045 || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
2046 && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
2047 {
2048 iso14_pcb_blocknum ^= 1;
2049 }
2050 return len;
2051 }
2052
2053
2054 //-----------------------------------------------------------------------------
2055 // Read an ISO 14443a tag. Send out commands and store answers.
2056 //-----------------------------------------------------------------------------
2057 void ReaderIso14443a(UsbCommand *c) {
2058 iso14a_command_t param = c->arg[0];
2059 size_t len = c->arg[1] & 0xffff;
2060 size_t lenbits = c->arg[1] >> 16;
2061 uint32_t timeout = c->arg[2];
2062 uint8_t *cmd = c->d.asBytes;
2063 uint32_t arg0 = 0;
2064 byte_t buf[USB_CMD_DATA_SIZE] = {0x00};
2065 uint8_t par[MAX_PARITY_SIZE] = {0x00};
2066
2067 if (param & ISO14A_CONNECT)
2068 clear_trace();
2069
2070 set_tracing(TRUE);
2071
2072 if (param & ISO14A_REQUEST_TRIGGER)
2073 iso14a_set_trigger(TRUE);
2074
2075 if (param & ISO14A_CONNECT) {
2076 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
2077 if(!(param & ISO14A_NO_SELECT)) {
2078 iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
2079 arg0 = iso14443a_select_card(NULL,card,NULL, true, 0);
2080 cmd_send(CMD_ACK, arg0, card->uidlen, 0, buf, sizeof(iso14a_card_select_t));
2081 // if it fails, the cmdhf14a.c client quites.. however this one still executes.
2082 if ( arg0 == 0 ) return;
2083 }
2084 }
2085
2086 if (param & ISO14A_SET_TIMEOUT)
2087 iso14a_set_timeout(timeout);
2088
2089 if (param & ISO14A_APDU) {
2090 arg0 = iso14_apdu(cmd, len, buf);
2091 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2092 }
2093
2094 if (param & ISO14A_RAW) {
2095 if (param & ISO14A_APPEND_CRC) {
2096 if (param & ISO14A_TOPAZMODE)
2097 AppendCrc14443b(cmd,len);
2098 else
2099 AppendCrc14443a(cmd,len);
2100
2101 len += 2;
2102 if (lenbits) lenbits += 16;
2103 }
2104 if (lenbits>0) { // want to send a specific number of bits (e.g. short commands)
2105 if (param & ISO14A_TOPAZMODE) {
2106 int bits_to_send = lenbits;
2107 uint16_t i = 0;
2108 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL); // first byte is always short (7bits) and no parity
2109 bits_to_send -= 7;
2110 while (bits_to_send > 0) {
2111 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL); // following bytes are 8 bit and no parity
2112 bits_to_send -= 8;
2113 }
2114 } else {
2115 GetParity(cmd, lenbits/8, par);
2116 ReaderTransmitBitsPar(cmd, lenbits, par, NULL); // bytes are 8 bit with odd parity
2117 }
2118 } else { // want to send complete bytes only
2119 if (param & ISO14A_TOPAZMODE) {
2120 uint16_t i = 0;
2121 ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL); // first byte: 7 bits, no paritiy
2122 while (i < len) {
2123 ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL); // following bytes: 8 bits, no paritiy
2124 }
2125 } else {
2126 ReaderTransmit(cmd,len, NULL); // 8 bits, odd parity
2127 }
2128 }
2129 arg0 = ReaderReceive(buf, par);
2130 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2131 }
2132
2133 if (param & ISO14A_REQUEST_TRIGGER)
2134 iso14a_set_trigger(FALSE);
2135
2136 if (param & ISO14A_NO_DISCONNECT)
2137 return;
2138
2139 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2140 set_tracing(FALSE);
2141 LEDsoff();
2142 }
2143
2144 // Determine the distance between two nonces.
2145 // Assume that the difference is small, but we don't know which is first.
2146 // Therefore try in alternating directions.
2147 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
2148
2149 if (nt1 == nt2) return 0;
2150
2151 uint32_t nttmp1 = nt1;
2152 uint32_t nttmp2 = nt2;
2153
2154 // 0xFFFF -- Half up and half down to find distance between nonces
2155 for (uint16_t i = 1; i < 32768/8; i += 8) {
2156 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i;
2157 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+1;
2158 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+2;
2159 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+3;
2160 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+4;
2161 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+5;
2162 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+6;
2163 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+7;
2164
2165 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -i;
2166 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+1);
2167 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+2);
2168 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+3);
2169 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+4);
2170 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+5);
2171 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+6);
2172 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+7);
2173 }
2174 // either nt1 or nt2 are invalid nonces
2175 return(-99999);
2176 }
2177
2178 //-----------------------------------------------------------------------------
2179 // Recover several bits of the cypher stream. This implements (first stages of)
2180 // the algorithm described in "The Dark Side of Security by Obscurity and
2181 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
2182 // (article by Nicolas T. Courtois, 2009)
2183 //-----------------------------------------------------------------------------
2184
2185 void ReaderMifare(bool first_try, uint8_t block, uint8_t keytype ) {
2186
2187 uint8_t mf_auth[] = { keytype, block, 0x00, 0x00 };
2188 uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
2189 uint8_t uid[10] = {0,0,0,0,0,0,0,0,0,0};
2190 uint8_t par_list[8] = {0,0,0,0,0,0,0,0};
2191 uint8_t ks_list[8] = {0,0,0,0,0,0,0,0};
2192 uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE] = {0x00};
2193 uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
2194 uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
2195 byte_t nt_diff = 0;
2196 uint32_t nt = 0;
2197 uint32_t previous_nt = 0;
2198 uint32_t cuid = 0;
2199
2200 int32_t catch_up_cycles = 0;
2201 int32_t last_catch_up = 0;
2202 int32_t isOK = 0;
2203 int32_t nt_distance = 0;
2204
2205 uint16_t elapsed_prng_sequences = 1;
2206 uint16_t consecutive_resyncs = 0;
2207 uint16_t unexpected_random = 0;
2208 uint16_t sync_tries = 0;
2209
2210 // static variables here, is re-used in the next call
2211 static uint32_t nt_attacked = 0;
2212 static uint32_t sync_time = 0;
2213 static uint32_t sync_cycles = 0;
2214 static uint8_t par_low = 0;
2215 static uint8_t mf_nr_ar3 = 0;
2216
2217 #define PRNG_SEQUENCE_LENGTH (1 << 16)
2218 #define MAX_UNEXPECTED_RANDOM 4 // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up.
2219 #define MAX_SYNC_TRIES 32
2220
2221 AppendCrc14443a(mf_auth, 2);
2222
2223 BigBuf_free(); BigBuf_Clear_ext(false);
2224 clear_trace();
2225 set_tracing(FALSE);
2226 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2227
2228 sync_time = GetCountSspClk() & 0xfffffff8;
2229 sync_cycles = PRNG_SEQUENCE_LENGTH; // Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
2230 nt_attacked = 0;
2231
2232 if (MF_DBGLEVEL >= 4) Dbprintf("Mifare::Sync %u", sync_time);
2233
2234 if (first_try) {
2235 mf_nr_ar3 = 0;
2236 par_low = 0;
2237 } else {
2238 // we were unsuccessful on a previous call.
2239 // Try another READER nonce (first 3 parity bits remain the same)
2240 ++mf_nr_ar3;
2241 mf_nr_ar[3] = mf_nr_ar3;
2242 par[0] = par_low;
2243 }
2244
2245 bool have_uid = FALSE;
2246 uint8_t cascade_levels = 0;
2247
2248 LED_C_ON();
2249 uint16_t i;
2250 for(i = 0; TRUE; ++i) {
2251
2252 WDT_HIT();
2253
2254 // Test if the action was cancelled
2255 if(BUTTON_PRESS()) {
2256 isOK = -1;
2257 break;
2258 }
2259
2260 // this part is from Piwi's faster nonce collecting part in Hardnested.
2261 if (!have_uid) { // need a full select cycle to get the uid first
2262 iso14a_card_select_t card_info;
2263 if(!iso14443a_select_card(uid, &card_info, &cuid, true, 0)) {
2264 if (MF_DBGLEVEL >= 4) Dbprintf("Mifare: Can't select card (ALL)");
2265 break;
2266 }
2267 switch (card_info.uidlen) {
2268 case 4 : cascade_levels = 1; break;
2269 case 7 : cascade_levels = 2; break;
2270 case 10: cascade_levels = 3; break;
2271 default: break;
2272 }
2273 have_uid = TRUE;
2274 } else { // no need for anticollision. We can directly select the card
2275 if(!iso14443a_select_card(uid, NULL, &cuid, false, cascade_levels)) {
2276 if (MF_DBGLEVEL >= 4) Dbprintf("Mifare: Can't select card (UID)");
2277 continue;
2278 }
2279 }
2280
2281 // Sending timeslot of ISO14443a frame
2282 sync_time = (sync_time & 0xfffffff8 ) + sync_cycles + catch_up_cycles;
2283 catch_up_cycles = 0;
2284
2285 // if we missed the sync time already, advance to the next nonce repeat
2286 while( GetCountSspClk() > sync_time) {
2287 ++elapsed_prng_sequences;
2288 sync_time = (sync_time & 0xfffffff8 ) + sync_cycles;
2289 }
2290
2291 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2292 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2293
2294 // Receive the (4 Byte) "random" nonce from TAG
2295 if (!ReaderReceive(receivedAnswer, receivedAnswerPar))
2296 continue;
2297
2298 previous_nt = nt;
2299 nt = bytes_to_num(receivedAnswer, 4);
2300
2301 // Transmit reader nonce with fake par
2302 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2303
2304 // we didn't calibrate our clock yet,
2305 // iceman: has to be calibrated every time.
2306 if (previous_nt && !nt_attacked) {
2307
2308 nt_distance = dist_nt(previous_nt, nt);
2309
2310 // if no distance between, then we are in sync.
2311 if (nt_distance == 0) {
2312 nt_attacked = nt;
2313 } else {
2314 if (nt_distance == -99999) { // invalid nonce received
2315 ++unexpected_random;
2316 if (unexpected_random > MAX_UNEXPECTED_RANDOM) {
2317 isOK = -3; // Card has an unpredictable PRNG. Give up
2318 break;
2319 } else {
2320 if (sync_cycles <= 0) sync_cycles += PRNG_SEQUENCE_LENGTH;
2321 LED_B_OFF();
2322 continue; // continue trying...
2323 }
2324 }
2325
2326 if (++sync_tries > MAX_SYNC_TRIES) {
2327 isOK = -4; // Card's PRNG runs at an unexpected frequency or resets unexpectedly
2328 break;
2329 }
2330
2331 sync_cycles = (sync_cycles - nt_distance)/elapsed_prng_sequences;
2332
2333 if (sync_cycles <= 0)
2334 sync_cycles += PRNG_SEQUENCE_LENGTH;
2335
2336 if (MF_DBGLEVEL >= 4)
2337 Dbprintf("calibrating in cycle %d. nt_distance=%d, elapsed_prng_sequences=%d, new sync_cycles: %d\n", i, nt_distance, elapsed_prng_sequences, sync_cycles);
2338
2339 LED_B_OFF();
2340 continue;
2341 }
2342 }
2343 LED_B_OFF();
2344
2345 if ( (nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
2346
2347 catch_up_cycles = ABS(dist_nt(nt_attacked, nt));
2348 if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one.
2349 catch_up_cycles = 0;
2350 continue;
2351 }
2352 // average?
2353 catch_up_cycles /= elapsed_prng_sequences;
2354
2355 if (catch_up_cycles == last_catch_up) {
2356 ++consecutive_resyncs;
2357 } else {
2358 last_catch_up = catch_up_cycles;
2359 consecutive_resyncs = 0;
2360 }
2361
2362 if (consecutive_resyncs < 3) {
2363 if (MF_DBGLEVEL >= 4)
2364 Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, catch_up_cycles, consecutive_resyncs);
2365 } else {
2366 sync_cycles += catch_up_cycles;
2367
2368 if (MF_DBGLEVEL >= 4)
2369 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);
2370
2371 last_catch_up = 0;
2372 catch_up_cycles = 0;
2373 consecutive_resyncs = 0;
2374 }
2375 continue;
2376 }
2377
2378 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2379 if (ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2380 catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2381
2382 if (nt_diff == 0)
2383 par_low = par[0] & 0xE0; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change
2384
2385 par_list[nt_diff] = SwapBits(par[0], 8);
2386 ks_list[nt_diff] = receivedAnswer[0] ^ 0x05; // xor with NACK value to get keystream
2387
2388 // Test if the information is complete
2389 if (nt_diff == 0x07) {
2390 isOK = 1;
2391 break;
2392 }
2393
2394 nt_diff = (nt_diff + 1) & 0x07;
2395 mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2396 par[0] = par_low;
2397
2398 } else {
2399 // No NACK.
2400 if (nt_diff == 0 && first_try) {
2401 par[0]++;
2402 if (par[0] == 0x00) { // tried all 256 possible parities without success. Card doesn't send NACK.
2403 isOK = -2;
2404 break;
2405 }
2406 } else {
2407 // Why this?
2408 par[0] = ((par[0] & 0x1F) + 1) | par_low;
2409 }
2410 }
2411
2412 // reset the resyncs since we got a complete transaction on right time.
2413 consecutive_resyncs = 0;
2414 } // end for loop
2415
2416 mf_nr_ar[3] &= 0x1F;
2417
2418 if (MF_DBGLEVEL >= 4) Dbprintf("Number of sent auth requestes: %u", i);
2419
2420 uint8_t buf[28] = {0x00};
2421 memset(buf, 0x00, sizeof(buf));
2422 num_to_bytes(cuid, 4, buf);
2423 num_to_bytes(nt, 4, buf + 4);
2424 memcpy(buf + 8, par_list, 8);
2425 memcpy(buf + 16, ks_list, 8);
2426 memcpy(buf + 24, mf_nr_ar, 4);
2427
2428 cmd_send(CMD_ACK, isOK, 0, 0, buf, sizeof(buf) );
2429
2430 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2431 LEDsoff();
2432 set_tracing(FALSE);
2433 }
2434
2435
2436 /**
2437 *MIFARE 1K simulate.
2438 *
2439 *@param flags :
2440 * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2441 * FLAG_4B_UID_IN_DATA - use 4-byte UID in the data-section
2442 * FLAG_7B_UID_IN_DATA - use 7-byte UID in the data-section
2443 * FLAG_10B_UID_IN_DATA - use 10-byte UID in the data-section
2444 * FLAG_UID_IN_EMUL - use 4-byte UID from emulator memory
2445 * FLAG_NR_AR_ATTACK - collect NR_AR responses for bruteforcing later
2446 *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2447 */
2448 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain) {
2449
2450 // init pseudorand
2451 fast_prand( GetTickCount() );
2452
2453 int cardSTATE = MFEMUL_NOFIELD;
2454 int _UID_LEN = 0; // 4, 7, 10
2455 int vHf = 0; // in mV
2456 int res = 0;
2457 uint32_t selTimer = 0;
2458 uint32_t authTimer = 0;
2459 uint16_t len = 0;
2460 uint8_t cardWRBL = 0;
2461 uint8_t cardAUTHSC = 0;
2462 uint8_t cardAUTHKEY = 0xff; // no authentication
2463 uint32_t cuid = 0;
2464 uint32_t ans = 0;
2465 uint32_t cardINTREG = 0;
2466 uint8_t cardINTBLOCK = 0;
2467 struct Crypto1State mpcs = {0, 0};
2468 struct Crypto1State *pcs;
2469 pcs = &mpcs;
2470 uint32_t numReads = 0; // Counts numer of times reader read a block
2471 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00};
2472 uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
2473 uint8_t response[MAX_MIFARE_FRAME_SIZE] = {0x00};
2474 uint8_t response_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
2475
2476 uint8_t atqa[] = {0x04, 0x00}; // Mifare classic 1k
2477 uint8_t sak_4[] = {0x0C, 0x00, 0x00}; // CL1 - 4b uid
2478 uint8_t sak_7[] = {0x0C, 0x00, 0x00}; // CL2 - 7b uid
2479 uint8_t sak_10[] = {0x0C, 0x00, 0x00}; // CL3 - 10b uid
2480 // uint8_t sak[] = {0x09, 0x3f, 0xcc }; // Mifare Mini
2481
2482 uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2483 uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2484 uint8_t rUIDBCC3[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2485
2486 // TAG Nonce - Authenticate response
2487 uint8_t rAUTH_NT[4];
2488 uint32_t nonce = prand();
2489 num_to_bytes(nonce, 4, rAUTH_NT);
2490
2491 // uint8_t rAUTH_NT[] = {0x55, 0x41, 0x49, 0x92};// nonce from nested? why this?
2492 uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2493
2494 // Here, we collect CUID, NT, NR, AR, CUID2, NT2, NR2, AR2
2495 // This can be used in a reader-only attack.
2496 nonces_t ar_nr_nonces[ATTACK_KEY_COUNT];
2497 memset(ar_nr_nonces, 0x00, sizeof(ar_nr_nonces));
2498
2499 // -- Determine the UID
2500 // Can be set from emulator memory or incoming data
2501 // Length: 4,7,or 10 bytes
2502 if ( (flags & FLAG_UID_IN_EMUL) == FLAG_UID_IN_EMUL)
2503 emlGetMemBt(datain, 0, 10); // load 10bytes from EMUL to the datain pointer. to be used below.
2504
2505 if ( (flags & FLAG_4B_UID_IN_DATA) == FLAG_4B_UID_IN_DATA) {
2506 memcpy(rUIDBCC1, datain, 4);
2507 _UID_LEN = 4;
2508 } else if ( (flags & FLAG_7B_UID_IN_DATA) == FLAG_7B_UID_IN_DATA) {
2509 memcpy(&rUIDBCC1[1], datain, 3);
2510 memcpy( rUIDBCC2, datain+3, 4);
2511 _UID_LEN = 7;
2512 } else if ( (flags & FLAG_10B_UID_IN_DATA) == FLAG_10B_UID_IN_DATA) {
2513 memcpy(&rUIDBCC1[1], datain, 3);
2514 memcpy(&rUIDBCC2[1], datain+3, 3);
2515 memcpy( rUIDBCC3, datain+6, 4);
2516 _UID_LEN = 10;
2517 }
2518
2519 switch (_UID_LEN) {
2520 case 4:
2521 sak_4[0] &= 0xFB;
2522 // save CUID
2523 cuid = bytes_to_num(rUIDBCC1, 4);
2524 // BCC
2525 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2526 if (MF_DBGLEVEL >= 2) {
2527 Dbprintf("4B UID: %02x%02x%02x%02x",
2528 rUIDBCC1[0],
2529 rUIDBCC1[1],
2530 rUIDBCC1[2],
2531 rUIDBCC1[3]
2532 );
2533 }
2534 break;
2535 case 7:
2536 atqa[0] |= 0x40;
2537 sak_7[0] &= 0xFB;
2538 // save CUID
2539 cuid = bytes_to_num(rUIDBCC2, 4);
2540 // CascadeTag, CT
2541 rUIDBCC1[0] = 0x88;
2542 // BCC
2543 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2544 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2545 if (MF_DBGLEVEL >= 2) {
2546 Dbprintf("7B UID: %02x %02x %02x %02x %02x %02x %02x",
2547 rUIDBCC1[1],
2548 rUIDBCC1[2],
2549 rUIDBCC1[3],
2550 rUIDBCC2[0],
2551 rUIDBCC2[1],
2552 rUIDBCC2[2],
2553 rUIDBCC2[3]
2554 );
2555 }
2556 break;
2557 case 10:
2558 atqa[0] |= 0x80;
2559 sak_10[0] &= 0xFB;
2560 // save CUID
2561 cuid = bytes_to_num(rUIDBCC3, 4);
2562 // CascadeTag, CT
2563 rUIDBCC1[0] = 0x88;
2564 rUIDBCC2[0] = 0x88;
2565 // BCC
2566 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2567 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2568 rUIDBCC3[4] = rUIDBCC3[0] ^ rUIDBCC3[1] ^ rUIDBCC3[2] ^ rUIDBCC3[3];
2569
2570 if (MF_DBGLEVEL >= 2) {
2571 Dbprintf("10B UID: %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
2572 rUIDBCC1[1],
2573 rUIDBCC1[2],
2574 rUIDBCC1[3],
2575 rUIDBCC2[1],
2576 rUIDBCC2[2],
2577 rUIDBCC2[3],
2578 rUIDBCC3[0],
2579 rUIDBCC3[1],
2580 rUIDBCC3[2],
2581 rUIDBCC3[3]
2582 );
2583 }
2584 break;
2585 default:
2586 break;
2587 }
2588 // calc some crcs
2589 ComputeCrc14443(CRC_14443_A, sak_4, 1, &sak_4[1], &sak_4[2]);
2590 ComputeCrc14443(CRC_14443_A, sak_7, 1, &sak_7[1], &sak_7[2]);
2591 ComputeCrc14443(CRC_14443_A, sak_10, 1, &sak_10[1], &sak_10[2]);
2592
2593 // We need to listen to the high-frequency, peak-detected path.
2594 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2595
2596 // free eventually allocated BigBuf memory but keep Emulator Memory
2597 BigBuf_free_keep_EM();
2598 clear_trace();
2599 set_tracing(TRUE);
2600
2601 bool finished = FALSE;
2602 while (!BUTTON_PRESS() && !finished && !usb_poll_validate_length()) {
2603 WDT_HIT();
2604
2605 // find reader field
2606 if (cardSTATE == MFEMUL_NOFIELD) {
2607 vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
2608 if (vHf > MF_MINFIELDV) {
2609 cardSTATE_TO_IDLE();
2610 LED_A_ON();
2611 }
2612 }
2613 if (cardSTATE == MFEMUL_NOFIELD) continue;
2614
2615 // Now, get data
2616 res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
2617 if (res == 2) { //Field is off!
2618 cardSTATE = MFEMUL_NOFIELD;
2619 LEDsoff();
2620 continue;
2621 } else if (res == 1) {
2622 break; // return value 1 means button press
2623 }
2624
2625 // REQ or WUP request in ANY state and WUP in HALTED state
2626 // this if-statement doesn't match the specification above. (iceman)
2627 if (len == 1 && ((receivedCmd[0] == ISO14443A_CMD_REQA && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == ISO14443A_CMD_WUPA)) {
2628 selTimer = GetTickCount();
2629 EmSendCmdEx(atqa, sizeof(atqa), (receivedCmd[0] == ISO14443A_CMD_WUPA));
2630 cardSTATE = MFEMUL_SELECT1;
2631 crypto1_destroy(pcs);
2632 cardAUTHKEY = 0xff;
2633 LEDsoff();
2634 nonce = prand();
2635 continue;
2636 }
2637
2638 switch (cardSTATE) {
2639 case MFEMUL_NOFIELD:
2640 case MFEMUL_HALTED:
2641 case MFEMUL_IDLE:{
2642 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2643 break;
2644 }
2645 case MFEMUL_SELECT1:{
2646 if (len == 2 && (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT && receivedCmd[1] == 0x20)) {
2647 if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received");
2648 EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2649 break;
2650 }
2651 // select card
2652 if (len == 9 &&
2653 ( receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT &&
2654 receivedCmd[1] == 0x70 &&
2655 memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2656
2657 // SAK 4b
2658 EmSendCmd(sak_4, sizeof(sak_4));
2659 switch(_UID_LEN){
2660 case 4:
2661 cardSTATE = MFEMUL_WORK;
2662 LED_B_ON();
2663 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2664 continue;
2665 case 7:
2666 case 10:
2667 cardSTATE = MFEMUL_SELECT2;
2668 continue;
2669 default:break;
2670 }
2671 } else {
2672 cardSTATE_TO_IDLE();
2673 }
2674 break;
2675 }
2676 case MFEMUL_SELECT2:{
2677 if (!len) {
2678 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2679 break;
2680 }
2681 if (len == 2 && (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2 && receivedCmd[1] == 0x20)) {
2682 EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2683 break;
2684 }
2685 if (len == 9 &&
2686 (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2 &&
2687 receivedCmd[1] == 0x70 &&
2688 memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0) ) {
2689
2690 EmSendCmd(sak_7, sizeof(sak_7));
2691 switch(_UID_LEN){
2692 case 7:
2693 cardSTATE = MFEMUL_WORK;
2694 LED_B_ON();
2695 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2696 continue;
2697 case 10:
2698 cardSTATE = MFEMUL_SELECT3;
2699 continue;
2700 default:break;
2701 }
2702 }
2703 cardSTATE_TO_IDLE();
2704 break;
2705 }
2706 case MFEMUL_SELECT3:{
2707 if (!len) {
2708 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2709 break;
2710 }
2711 if (len == 2 && (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_3 && receivedCmd[1] == 0x20)) {
2712 EmSendCmd(rUIDBCC3, sizeof(rUIDBCC3));
2713 break;
2714 }
2715 if (len == 9 &&
2716 (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_3 &&
2717 receivedCmd[1] == 0x70 &&
2718 memcmp(&receivedCmd[2], rUIDBCC3, 4) == 0) ) {
2719
2720 EmSendCmd(sak_10, sizeof(sak_10));
2721 cardSTATE = MFEMUL_WORK;
2722 LED_B_ON();
2723 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol3 time: %d", GetTickCount() - selTimer);
2724 break;
2725 }
2726 cardSTATE_TO_IDLE();
2727 break;
2728 }
2729 case MFEMUL_AUTH1:{
2730 if( len != 8) {
2731 cardSTATE_TO_IDLE();
2732 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2733 break;
2734 }
2735
2736 uint32_t nr = bytes_to_num(receivedCmd, 4);
2737 uint32_t ar = bytes_to_num(&receivedCmd[4], 4);
2738
2739 // Collect AR/NR per keytype & sector
2740 if ( (flags & FLAG_NR_AR_ATTACK) == FLAG_NR_AR_ATTACK ) {
2741
2742 int8_t index = -1;
2743 int8_t empty = -1;
2744 for (uint8_t i = 0; i < ATTACK_KEY_COUNT; i++) {
2745 // find which index to use
2746 if ( (cardAUTHSC == ar_nr_nonces[i].sector) && (cardAUTHKEY == ar_nr_nonces[i].keytype))
2747 index = i;
2748
2749 // keep track of empty slots.
2750 if ( ar_nr_nonces[i].state == EMPTY)
2751 empty = i;
2752 }
2753 // if no empty slots. Choose first and overwrite.
2754 if ( index == -1 ) {
2755 if ( empty == -1 ) {
2756 index = 0;
2757 ar_nr_nonces[index].state = EMPTY;
2758 } else {
2759 index = empty;
2760 }
2761 }
2762
2763 switch(ar_nr_nonces[index].state) {
2764 case EMPTY: {
2765 // first nonce collect
2766 ar_nr_nonces[index].cuid = cuid;
2767 ar_nr_nonces[index].sector = cardAUTHSC;
2768 ar_nr_nonces[index].keytype = cardAUTHKEY;
2769 ar_nr_nonces[index].nonce = nonce;
2770 ar_nr_nonces[index].nr = nr;
2771 ar_nr_nonces[index].ar = ar;
2772 ar_nr_nonces[index].state = FIRST;
2773 break;
2774 }
2775 case FIRST : {
2776 // second nonce collect
2777 ar_nr_nonces[index].nonce2 = nonce;
2778 ar_nr_nonces[index].nr2 = nr;
2779 ar_nr_nonces[index].ar2 = ar;
2780 ar_nr_nonces[index].state = SECOND;
2781
2782 // send to client
2783 cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, 0, 0, &ar_nr_nonces[index], sizeof(nonces_t));
2784
2785 ar_nr_nonces[index].state = EMPTY;
2786 ar_nr_nonces[index].sector = 0;
2787 ar_nr_nonces[index].keytype = 0;
2788 break;
2789 }
2790 default: break;
2791 }
2792 }
2793
2794 crypto1_word(pcs, nr , 1);
2795 uint32_t cardRr = ar ^ crypto1_word(pcs, 0, 0);
2796
2797 //test if auth OK
2798 if (cardRr != prng_successor(nonce, 64)){
2799
2800 if (MF_DBGLEVEL >= 3)
2801 Dbprintf("AUTH FAILED for sector %d with key %c. [nr=%08x cardRr=%08x] [nt=%08x succ=%08x]"
2802 , cardAUTHSC
2803 , (cardAUTHKEY == 0) ? 'A' : 'B'
2804 , nr
2805 , cardRr
2806 , nonce // nt
2807 , prng_successor(nonce, 64)
2808
2809 );
2810 // Shouldn't we respond anything here?
2811 // Right now, we don't nack or anything, which causes the
2812 // reader to do a WUPA after a while. /Martin
2813 // -- which is the correct response. /piwi
2814 cardSTATE_TO_IDLE();
2815 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2816 break;
2817 }
2818
2819 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2820 num_to_bytes(ans, 4, rAUTH_AT);
2821 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2822 LED_C_ON();
2823
2824 if (MF_DBGLEVEL >= 1) {
2825 Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2826 cardAUTHSC,
2827 cardAUTHKEY == 0 ? 'A' : 'B',
2828 GetTickCount() - authTimer
2829 );
2830 }
2831 cardSTATE = MFEMUL_WORK;
2832 break;
2833 }
2834 case MFEMUL_WORK:{
2835 if (len == 0) {
2836 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2837 break;
2838 }
2839 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2840
2841 if(encrypted_data)
2842 mf_crypto1_decrypt(pcs, receivedCmd, len);
2843
2844 if (len == 4 && (receivedCmd[0] == MIFARE_AUTH_KEYA ||
2845 receivedCmd[0] == MIFARE_AUTH_KEYB) ) {
2846
2847 authTimer = GetTickCount();
2848 cardAUTHSC = receivedCmd[1] / 4; // received block -> sector
2849 cardAUTHKEY = receivedCmd[0] & 0x1;
2850 crypto1_destroy(pcs);
2851
2852 // load key into crypto
2853 crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2854
2855 if (!encrypted_data) {
2856 // first authentication
2857 // Update crypto state init (UID ^ NONCE)
2858 crypto1_word(pcs, cuid ^ nonce, 0);
2859 num_to_bytes(nonce, 4, rAUTH_AT);
2860 }
2861
2862 } else {
2863 // nested authentication
2864 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2865 num_to_bytes(ans, 4, rAUTH_AT);
2866
2867 if (MF_DBGLEVEL >= 3) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %c", receivedCmd[1], receivedCmd[1], cardAUTHKEY == 0 ? 'A' : 'B');
2868 }
2869
2870 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2871 cardSTATE = MFEMUL_AUTH1;
2872 break;
2873 }
2874
2875 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2876 // BUT... ACK --> NACK
2877 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2878 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2879 break;
2880 }
2881
2882 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2883 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2884 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2885 break;
2886 }
2887
2888 if(len != 4) {
2889 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2890 break;
2891 }
2892
2893 if ( receivedCmd[0] == ISO14443A_CMD_READBLOCK ||
2894 receivedCmd[0] == ISO14443A_CMD_WRITEBLOCK ||
2895 receivedCmd[0] == MIFARE_CMD_INC ||
2896 receivedCmd[0] == MIFARE_CMD_DEC ||
2897 receivedCmd[0] == MIFARE_CMD_RESTORE ||
2898 receivedCmd[0] == MIFARE_CMD_TRANSFER ) {
2899
2900 if (receivedCmd[1] >= 16 * 4) {
2901 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2902 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate (0x%02) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2903 break;
2904 }
2905
2906 if (receivedCmd[1] / 4 != cardAUTHSC) {
2907 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2908 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate (0x%02) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
2909 break;
2910 }
2911 }
2912 // read block
2913 if (receivedCmd[0] == ISO14443A_CMD_READBLOCK) {
2914 if (MF_DBGLEVEL >= 4) Dbprintf("Reader reading block %d (0x%02x)", receivedCmd[1], receivedCmd[1]);
2915
2916 emlGetMem(response, receivedCmd[1], 1);
2917 AppendCrc14443a(response, 16);
2918 mf_crypto1_encrypt(pcs, response, 18, response_par);
2919 EmSendCmdPar(response, 18, response_par);
2920 numReads++;
2921 if(exitAfterNReads > 0 && numReads >= exitAfterNReads) {
2922 Dbprintf("%d reads done, exiting", numReads);
2923 finished = true;
2924 }
2925 break;
2926 }
2927 // write block
2928 if (receivedCmd[0] == ISO14443A_CMD_WRITEBLOCK) {
2929 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)", receivedCmd[1], receivedCmd[1]);
2930 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2931 cardSTATE = MFEMUL_WRITEBL2;
2932 cardWRBL = receivedCmd[1];
2933 break;
2934 }
2935 // increment, decrement, restore
2936 if ( receivedCmd[0] == MIFARE_CMD_INC ||
2937 receivedCmd[0] == MIFARE_CMD_DEC ||
2938 receivedCmd[0] == MIFARE_CMD_RESTORE) {
2939
2940 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0], receivedCmd[1], receivedCmd[1]);
2941
2942 if (emlCheckValBl(receivedCmd[1])) {
2943 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2944 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2945 break;
2946 }
2947 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2948 if (receivedCmd[0] == MIFARE_CMD_INC) cardSTATE = MFEMUL_INTREG_INC;
2949 if (receivedCmd[0] == MIFARE_CMD_DEC) cardSTATE = MFEMUL_INTREG_DEC;
2950 if (receivedCmd[0] == MIFARE_CMD_RESTORE) cardSTATE = MFEMUL_INTREG_REST;
2951 cardWRBL = receivedCmd[1];
2952 break;
2953 }
2954 // transfer
2955 if (receivedCmd[0] == MIFARE_CMD_TRANSFER) {
2956 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)", receivedCmd[0], receivedCmd[1], receivedCmd[1]);
2957 if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2958 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2959 else
2960 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2961 break;
2962 }
2963 // halt
2964 if (receivedCmd[0] == ISO14443A_CMD_HALT && receivedCmd[1] == 0x00) {
2965 LED_B_OFF();
2966 LED_C_OFF();
2967 cardSTATE = MFEMUL_HALTED;
2968 if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer);
2969 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2970 break;
2971 }
2972 // RATS
2973 if (receivedCmd[0] == ISO14443A_CMD_RATS) {
2974 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2975 break;
2976 }
2977 // command not allowed
2978 if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking");
2979 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2980 break;
2981 }
2982 case MFEMUL_WRITEBL2:{
2983 if (len == 18) {
2984 mf_crypto1_decrypt(pcs, receivedCmd, len);
2985 emlSetMem(receivedCmd, cardWRBL, 1);
2986 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2987 cardSTATE = MFEMUL_WORK;
2988 } else {
2989 cardSTATE_TO_IDLE();
2990 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2991 }
2992 break;
2993 }
2994 case MFEMUL_INTREG_INC:{
2995 mf_crypto1_decrypt(pcs, receivedCmd, len);
2996 memcpy(&ans, receivedCmd, 4);
2997 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2998 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2999 cardSTATE_TO_IDLE();
3000 break;
3001 }
3002 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
3003 cardINTREG = cardINTREG + ans;
3004 cardSTATE = MFEMUL_WORK;
3005 break;
3006 }
3007 case MFEMUL_INTREG_DEC:{
3008 mf_crypto1_decrypt(pcs, receivedCmd, len);
3009 memcpy(&ans, receivedCmd, 4);
3010 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
3011 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
3012 cardSTATE_TO_IDLE();
3013 break;
3014 }
3015 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
3016 cardINTREG = cardINTREG - ans;
3017 cardSTATE = MFEMUL_WORK;
3018 break;
3019 }
3020 case MFEMUL_INTREG_REST:{
3021 mf_crypto1_decrypt(pcs, receivedCmd, len);
3022 memcpy(&ans, receivedCmd, 4);
3023 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
3024 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
3025 cardSTATE_TO_IDLE();
3026 break;
3027 }
3028 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
3029 cardSTATE = MFEMUL_WORK;
3030 break;
3031 }
3032 }
3033 }
3034
3035 if (MF_DBGLEVEL >= 1)
3036 Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen());
3037
3038 cmd_send(CMD_ACK,1,0,0,0,0); FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
3039 LEDsoff();
3040 set_tracing(FALSE);
3041 }
3042
3043
3044 //-----------------------------------------------------------------------------
3045 // MIFARE sniffer.
3046 //
3047 // if no activity for 2sec, it sends the collected data to the client.
3048 //-----------------------------------------------------------------------------
3049 // "hf mf sniff"
3050 void RAMFUNC SniffMifare(uint8_t param) {
3051
3052 LEDsoff();
3053
3054 // free eventually allocated BigBuf memory
3055 BigBuf_free(); BigBuf_Clear_ext(false);
3056 clear_trace();
3057 set_tracing(TRUE);
3058
3059 // The command (reader -> tag) that we're receiving.
3060 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00};
3061 uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
3062
3063 // The response (tag -> reader) that we're receiving.
3064 uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE] = {0x00};
3065 uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE] = {0x00};
3066
3067 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
3068
3069 // allocate the DMA buffer, used to stream samples from the FPGA
3070 // [iceman] is this sniffed data unsigned?
3071 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
3072 uint8_t *data = dmaBuf;
3073 uint8_t previous_data = 0;
3074 int maxDataLen = 0;
3075 int dataLen = 0;
3076 bool ReaderIsActive = FALSE;
3077 bool TagIsActive = FALSE;
3078
3079 // Set up the demodulator for tag -> reader responses.
3080 DemodInit(receivedResponse, receivedResponsePar);
3081
3082 // Set up the demodulator for the reader -> tag commands
3083 UartInit(receivedCmd, receivedCmdPar);
3084
3085 // Setup and start DMA.
3086 // set transfer address and number of bytes. Start transfer.
3087 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, DMA_BUFFER_SIZE) ){
3088 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
3089 return;
3090 }
3091
3092 LED_D_OFF();
3093
3094 MfSniffInit();
3095
3096 // And now we loop, receiving samples.
3097 for(uint32_t sniffCounter = 0;; ) {
3098
3099 LED_A_ON();
3100 WDT_HIT();
3101
3102 if(BUTTON_PRESS()) {
3103 DbpString("cancelled by button");
3104 break;
3105 }
3106
3107 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
3108 // check if a transaction is completed (timeout after 2000ms).
3109 // if yes, stop the DMA transfer and send what we have so far to the client
3110 if (MfSniffSend(2000)) {
3111 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
3112 sniffCounter = 0;
3113 data = dmaBuf;
3114 maxDataLen = 0;
3115 ReaderIsActive = FALSE;
3116 TagIsActive = FALSE;
3117 // Setup and start DMA. set transfer address and number of bytes. Start transfer.
3118 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, DMA_BUFFER_SIZE) ){
3119 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
3120 return;
3121 }
3122 }
3123 }
3124
3125 int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
3126 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
3127
3128 if (readBufDataP <= dmaBufDataP) // we are processing the same block of data which is currently being transferred
3129 dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
3130 else
3131 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
3132
3133 // test for length of buffer
3134 if(dataLen > maxDataLen) { // we are more behind than ever...
3135 maxDataLen = dataLen;
3136 if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
3137 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
3138 break;
3139 }
3140 }
3141 if(dataLen < 1) continue;
3142
3143 // primary buffer was stopped ( <-- we lost data!
3144 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
3145 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
3146 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
3147 Dbprintf("RxEmpty ERROR, data length:%d", dataLen); // temporary
3148 }
3149 // secondary buffer sets as primary, secondary buffer was stopped
3150 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
3151 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
3152 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
3153 }
3154
3155 LED_A_OFF();
3156
3157 if (sniffCounter & 0x01) {
3158
3159 // no need to try decoding tag data if the reader is sending
3160 if(!TagIsActive) {
3161 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
3162 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
3163 LED_C_INV();
3164
3165 if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
3166
3167 UartInit(receivedCmd, receivedCmdPar);
3168 DemodReset();
3169 }
3170 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
3171 }
3172
3173 // no need to try decoding tag data if the reader is sending
3174 if(!ReaderIsActive) {
3175 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
3176 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
3177 LED_C_INV();
3178
3179 if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
3180
3181 DemodReset();
3182 UartInit(receivedCmd, receivedCmdPar);
3183 }
3184 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
3185 }
3186 }
3187
3188 previous_data = *data;
3189 sniffCounter++;
3190 data++;
3191
3192 if(data == dmaBuf + DMA_BUFFER_SIZE)
3193 data = dmaBuf;
3194
3195 } // main cycle
3196
3197 if (MF_DBGLEVEL >= 1) Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
3198
3199 FpgaDisableSscDma();
3200 MfSniffEnd();
3201 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
3202 LEDsoff();
3203 set_tracing(FALSE);
3204 }
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