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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 uint8_t sak = 0;
853 uint32_t cuid = 0;
854 uint32_t nonce = 0;
855
856 // PACK response to PWD AUTH for EV1/NTAG
857 uint8_t response8[4] = {0,0,0,0};
858 // Counter for EV1/NTAG
859 uint32_t counters[] = {0,0,0};
860
861 // The first response contains the ATQA (note: bytes are transmitted in reverse order).
862 uint8_t response1[] = {0,0};
863
864 // Here, we collect CUID, block1, keytype1, NT1, NR1, AR1, CUID, block2, keytyp2, NT2, NR2, AR2
865 // it should also collect block, keytype.
866 uint8_t cardAUTHSC = 0;
867 uint8_t cardAUTHKEY = 0xff; // no authentication
868 // allow collecting up to 8 sets of nonces to allow recovery of up to 8 keys
869 #define ATTACK_KEY_COUNT 8 // keep same as define in cmdhfmf.c -> readerAttack()
870 nonces_t ar_nr_resp[ATTACK_KEY_COUNT*2]; // for 2 separate attack types (nml, moebius)
871 memset(ar_nr_resp, 0x00, sizeof(ar_nr_resp));
872
873 uint8_t ar_nr_collected[ATTACK_KEY_COUNT*2]; // for 2nd attack type (moebius)
874 memset(ar_nr_collected, 0x00, sizeof(ar_nr_collected));
875 uint8_t nonce1_count = 0;
876 uint8_t nonce2_count = 0;
877 uint8_t moebius_n_count = 0;
878 bool gettingMoebius = false;
879 uint8_t mM = 0; // moebius_modifier for collection storage
880
881
882 switch (tagType) {
883 case 1: { // MIFARE Classic 1k
884 response1[0] = 0x04;
885 sak = 0x08;
886 } break;
887 case 2: { // MIFARE Ultralight
888 response1[0] = 0x44;
889 sak = 0x00;
890 } break;
891 case 3: { // MIFARE DESFire
892 response1[0] = 0x04;
893 response1[1] = 0x03;
894 sak = 0x20;
895 } break;
896 case 4: { // ISO/IEC 14443-4 - javacard (JCOP)
897 response1[0] = 0x04;
898 sak = 0x28;
899 } break;
900 case 5: { // MIFARE TNP3XXX
901 response1[0] = 0x01;
902 response1[1] = 0x0f;
903 sak = 0x01;
904 } break;
905 case 6: { // MIFARE Mini 320b
906 response1[0] = 0x44;
907 sak = 0x09;
908 } break;
909 case 7: { // NTAG
910 response1[0] = 0x44;
911 sak = 0x00;
912 // PACK
913 response8[0] = 0x80;
914 response8[1] = 0x80;
915 ComputeCrc14443(CRC_14443_A, response8, 2, &response8[2], &response8[3]);
916 // uid not supplied then get from emulator memory
917 if (data[0]==0) {
918 uint16_t start = 4 * (0+12);
919 uint8_t emdata[8];
920 emlGetMemBt( emdata, start, sizeof(emdata));
921 memcpy(data, emdata, 3); // uid bytes 0-2
922 memcpy(data+3, emdata+4, 4); // uid bytes 3-7
923 flags |= FLAG_7B_UID_IN_DATA;
924 }
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 uint8_t response5[] = { 0x01, 0x01, 0x01, 0x01 }; // Very random tag nonce
976 uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS:
977 // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
978 // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
979 // 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)
980 // TC(1) = 0x02: CID supported, NAD not supported
981 ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
982
983 // the randon nonce
984 nonce = bytes_to_num(response5, 4);
985
986 // Prepare GET_VERSION (different for UL EV-1 / NTAG)
987 // uint8_t response7_EV1[] = {0x00, 0x04, 0x03, 0x01, 0x01, 0x00, 0x0b, 0x03, 0xfd, 0xf7}; //EV1 48bytes VERSION.
988 // uint8_t response7_NTAG[] = {0x00, 0x04, 0x04, 0x02, 0x01, 0x00, 0x11, 0x03, 0x01, 0x9e}; //NTAG 215
989 // Prepare CHK_TEARING
990 // uint8_t response9[] = {0xBD,0x90,0x3f};
991
992 #define TAG_RESPONSE_COUNT 10
993 tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
994 { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type
995 { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid
996 { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked
997 { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1
998 { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2
999 { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce)
1000 { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS
1001
1002 { .response = response8, .response_n = sizeof(response8) } // EV1/NTAG PACK response
1003 };
1004 // { .response = response7_NTAG, .response_n = sizeof(response7_NTAG)}, // EV1/NTAG GET_VERSION response
1005 // { .response = response9, .response_n = sizeof(response9) } // EV1/NTAG CHK_TEAR response
1006
1007
1008 // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
1009 // Such a response is less time critical, so we can prepare them on the fly
1010 #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
1011 #define DYNAMIC_MODULATION_BUFFER_SIZE 512
1012 uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
1013 uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
1014 tag_response_info_t dynamic_response_info = {
1015 .response = dynamic_response_buffer,
1016 .response_n = 0,
1017 .modulation = dynamic_modulation_buffer,
1018 .modulation_n = 0
1019 };
1020
1021 // We need to listen to the high-frequency, peak-detected path.
1022 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1023
1024 BigBuf_free_keep_EM();
1025 clear_trace();
1026 set_tracing(TRUE);
1027
1028 // allocate buffers:
1029 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
1030 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
1031 free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
1032
1033 // Prepare the responses of the anticollision phase
1034 // there will be not enough time to do this at the moment the reader sends it REQA
1035 for (size_t i=0; i<TAG_RESPONSE_COUNT; i++)
1036 prepare_allocated_tag_modulation(&responses[i]);
1037
1038 int len = 0;
1039
1040 // To control where we are in the protocol
1041 int order = 0;
1042 int lastorder;
1043
1044 // Just to allow some checks
1045 int happened = 0;
1046 int happened2 = 0;
1047 int cmdsRecvd = 0;
1048 tag_response_info_t* p_response;
1049
1050 LED_A_ON();
1051 for(;;) {
1052 WDT_HIT();
1053
1054 // Clean receive command buffer
1055 if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
1056 DbpString("Button press");
1057 break;
1058 }
1059
1060 // incease nonce at every command recieved
1061 nonce++;
1062 num_to_bytes(nonce, 4, response5);
1063
1064 p_response = NULL;
1065
1066 // Okay, look at the command now.
1067 lastorder = order;
1068 if(receivedCmd[0] == ISO14443A_CMD_REQA) { // Received a REQUEST
1069 p_response = &responses[0]; order = 1;
1070 } else if(receivedCmd[0] == ISO14443A_CMD_WUPA) { // Received a WAKEUP
1071 p_response = &responses[0]; order = 6;
1072 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT) { // Received request for UID (cascade 1)
1073 p_response = &responses[1]; order = 2;
1074 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2) { // Received request for UID (cascade 2)
1075 p_response = &responses[2]; order = 20;
1076 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT) { // Received a SELECT (cascade 1)
1077 p_response = &responses[3]; order = 3;
1078 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2) { // Received a SELECT (cascade 2)
1079 p_response = &responses[4]; order = 30;
1080 } else if(receivedCmd[0] == ISO14443A_CMD_READBLOCK) { // Received a (plain) READ
1081 uint8_t block = receivedCmd[1];
1082 // if Ultralight or NTAG (4 byte blocks)
1083 if ( tagType == 7 || tagType == 2 ) {
1084 // first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1085 uint16_t start = 4 * (block+12);
1086 uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
1087 emlGetMemBt( emdata, start, 16);
1088 AppendCrc14443a(emdata, 16);
1089 EmSendCmdEx(emdata, sizeof(emdata), false);
1090 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1091 p_response = NULL;
1092 } else { // all other tags (16 byte block tags)
1093 uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
1094 emlGetMemBt( emdata, block, 16);
1095 AppendCrc14443a(emdata, 16);
1096 EmSendCmdEx(emdata, sizeof(emdata), false);
1097 // EmSendCmdEx(data+(4*receivedCmd[1]),16,false);
1098 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1099 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1100 p_response = NULL;
1101 }
1102 } else if(receivedCmd[0] == MIFARE_ULEV1_FASTREAD) { // Received a FAST READ (ranged read)
1103 uint8_t emdata[MAX_FRAME_SIZE];
1104 // first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1105 int start = (receivedCmd[1]+12) * 4;
1106 int len = (receivedCmd[2] - receivedCmd[1] + 1) * 4;
1107 emlGetMemBt( emdata, start, len);
1108 AppendCrc14443a(emdata, len);
1109 EmSendCmdEx(emdata, len+2, false);
1110 p_response = NULL;
1111 } else if(receivedCmd[0] == MIFARE_ULEV1_READSIG && tagType == 7) { // Received a READ SIGNATURE --
1112 // first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1113 uint16_t start = 4 * 4;
1114 uint8_t emdata[34];
1115 emlGetMemBt( emdata, start, 32);
1116 AppendCrc14443a(emdata, 32);
1117 EmSendCmdEx(emdata, sizeof(emdata), false);
1118 p_response = NULL;
1119 } else if (receivedCmd[0] == MIFARE_ULEV1_READ_CNT && tagType == 7) { // Received a READ COUNTER --
1120 uint8_t index = receivedCmd[1];
1121 uint8_t data[] = {0x00,0x00,0x00,0x14,0xa5};
1122 if ( counters[index] > 0) {
1123 num_to_bytes(counters[index], 3, data);
1124 AppendCrc14443a(data, sizeof(data)-2);
1125 }
1126 EmSendCmdEx(data,sizeof(data),false);
1127 p_response = NULL;
1128 } else if (receivedCmd[0] == MIFARE_ULEV1_INCR_CNT && tagType == 7) { // Received a INC COUNTER --
1129 // number of counter
1130 uint8_t counter = receivedCmd[1];
1131 uint32_t val = bytes_to_num(receivedCmd+2,4);
1132 counters[counter] = val;
1133
1134 // send ACK
1135 uint8_t ack[] = {0x0a};
1136 EmSendCmdEx(ack,sizeof(ack),false);
1137 p_response = NULL;
1138 } else if(receivedCmd[0] == MIFARE_ULEV1_CHECKTEAR && tagType == 7) { // Received a CHECK_TEARING_EVENT --
1139 // first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1140 uint8_t emdata[3];
1141 uint8_t counter=0;
1142 if (receivedCmd[1]<3) counter = receivedCmd[1];
1143 emlGetMemBt( emdata, 10+counter, 1);
1144 AppendCrc14443a(emdata, sizeof(emdata)-2);
1145 EmSendCmdEx(emdata, sizeof(emdata), false);
1146 p_response = NULL;
1147 } else if(receivedCmd[0] == ISO14443A_CMD_HALT) { // Received a HALT
1148 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1149 p_response = NULL;
1150 } else if(receivedCmd[0] == MIFARE_AUTH_KEYA || receivedCmd[0] == MIFARE_AUTH_KEYB) { // Received an authentication request
1151 if ( tagType == 7 ) { // IF NTAG /EV1 0x60 == GET_VERSION, not a authentication request.
1152 uint8_t emdata[10];
1153 emlGetMemBt( emdata, 0, 8 );
1154 AppendCrc14443a(emdata, sizeof(emdata)-2);
1155 EmSendCmdEx(emdata, sizeof(emdata), false);
1156 p_response = NULL;
1157 } else {
1158 cardAUTHSC = receivedCmd[1] / 4; // received block num
1159 cardAUTHKEY = receivedCmd[0] - 0x60;
1160 p_response = &responses[5]; order = 7;
1161 }
1162 } else if(receivedCmd[0] == ISO14443A_CMD_RATS) { // Received a RATS request
1163 if (tagType == 1 || tagType == 2) { // RATS not supported
1164 EmSend4bit(CARD_NACK_NA);
1165 p_response = NULL;
1166 } else {
1167 p_response = &responses[6]; order = 70;
1168 }
1169 } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
1170 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1171 uint32_t nr = bytes_to_num(receivedCmd,4);
1172 uint32_t ar = bytes_to_num(receivedCmd+4,4);
1173
1174 // Collect AR/NR per keytype & sector
1175 if ( (flags & FLAG_NR_AR_ATTACK) == FLAG_NR_AR_ATTACK ) {
1176 for (uint8_t i = 0; i < ATTACK_KEY_COUNT; i++) {
1177 if ( ar_nr_collected[i+mM]==0 || ((cardAUTHSC == ar_nr_resp[i+mM].sector) && (cardAUTHKEY == ar_nr_resp[i+mM].keytype) && (ar_nr_collected[i+mM] > 0)) ) {
1178 // if first auth for sector, or matches sector and keytype of previous auth
1179 if (ar_nr_collected[i+mM] < 2) {
1180 // if we haven't already collected 2 nonces for this sector
1181 if (ar_nr_resp[ar_nr_collected[i+mM]].ar != ar) {
1182 // Avoid duplicates... probably not necessary, ar should vary.
1183 if (ar_nr_collected[i+mM]==0) {
1184 // first nonce collect
1185 ar_nr_resp[i+mM].cuid = cuid;
1186 ar_nr_resp[i+mM].sector = cardAUTHSC;
1187 ar_nr_resp[i+mM].keytype = cardAUTHKEY;
1188 ar_nr_resp[i+mM].nonce = nonce;
1189 ar_nr_resp[i+mM].nr = nr;
1190 ar_nr_resp[i+mM].ar = ar;
1191 nonce1_count++;
1192 // add this nonce to first moebius nonce
1193 ar_nr_resp[i+ATTACK_KEY_COUNT].cuid = cuid;
1194 ar_nr_resp[i+ATTACK_KEY_COUNT].sector = cardAUTHSC;
1195 ar_nr_resp[i+ATTACK_KEY_COUNT].keytype = cardAUTHKEY;
1196 ar_nr_resp[i+ATTACK_KEY_COUNT].nonce = nonce;
1197 ar_nr_resp[i+ATTACK_KEY_COUNT].nr = nr;
1198 ar_nr_resp[i+ATTACK_KEY_COUNT].ar = ar;
1199 ar_nr_collected[i+ATTACK_KEY_COUNT]++;
1200 } else { // second nonce collect (std and moebius)
1201 ar_nr_resp[i+mM].nonce2 = nonce;
1202 ar_nr_resp[i+mM].nr2 = nr;
1203 ar_nr_resp[i+mM].ar2 = ar;
1204 if (!gettingMoebius) {
1205 nonce2_count++;
1206 // check if this was the last second nonce we need for std attack
1207 if ( nonce2_count == nonce1_count ) {
1208 // done collecting std test switch to moebius
1209 // first finish incrementing last sample
1210 ar_nr_collected[i+mM]++;
1211 // switch to moebius collection
1212 gettingMoebius = true;
1213 mM = ATTACK_KEY_COUNT;
1214 break;
1215 }
1216 } else {
1217 moebius_n_count++;
1218 // if we've collected all the nonces we need - finish.
1219 if (nonce1_count == moebius_n_count) {
1220 cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_resp,sizeof(ar_nr_resp));
1221 nonce1_count = 0;
1222 nonce2_count = 0;
1223 moebius_n_count = 0;
1224 gettingMoebius = false;
1225 }
1226 }
1227 }
1228 ar_nr_collected[i+mM]++;
1229 }
1230 }
1231 // we found right spot for this nonce stop looking
1232 break;
1233 }
1234 }
1235 }
1236
1237 } else if (receivedCmd[0] == MIFARE_ULC_AUTH_1 ) { // ULC authentication, or Desfire Authentication
1238 } else if (receivedCmd[0] == MIFARE_ULEV1_AUTH) { // NTAG / EV-1 authentication
1239 if ( tagType == 7 ) {
1240 uint16_t start = 13; // first 4 blocks of emu are [getversion answer - check tearing - pack - 0x00]
1241 uint8_t emdata[4];
1242 emlGetMemBt( emdata, start, 2);
1243 AppendCrc14443a(emdata, 2);
1244 EmSendCmdEx(emdata, sizeof(emdata), false);
1245 p_response = NULL;
1246 uint32_t pwd = bytes_to_num(receivedCmd+1,4);
1247
1248 if ( MF_DBGLEVEL >= 3) Dbprintf("Auth attempt: %08x", pwd);
1249 }
1250 } else {
1251 // Check for ISO 14443A-4 compliant commands, look at left nibble
1252 switch (receivedCmd[0]) {
1253 case 0x02:
1254 case 0x03: { // IBlock (command no CID)
1255 dynamic_response_info.response[0] = receivedCmd[0];
1256 dynamic_response_info.response[1] = 0x90;
1257 dynamic_response_info.response[2] = 0x00;
1258 dynamic_response_info.response_n = 3;
1259 } break;
1260 case 0x0B:
1261 case 0x0A: { // IBlock (command CID)
1262 dynamic_response_info.response[0] = receivedCmd[0];
1263 dynamic_response_info.response[1] = 0x00;
1264 dynamic_response_info.response[2] = 0x90;
1265 dynamic_response_info.response[3] = 0x00;
1266 dynamic_response_info.response_n = 4;
1267 } break;
1268
1269 case 0x1A:
1270 case 0x1B: { // Chaining command
1271 dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1272 dynamic_response_info.response_n = 2;
1273 } break;
1274
1275 case 0xaa:
1276 case 0xbb: {
1277 dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1278 dynamic_response_info.response_n = 2;
1279 } break;
1280
1281 case 0xBA: { // ping / pong
1282 dynamic_response_info.response[0] = 0xAB;
1283 dynamic_response_info.response[1] = 0x00;
1284 dynamic_response_info.response_n = 2;
1285 } break;
1286
1287 case 0xCA:
1288 case 0xC2: { // Readers sends deselect command
1289 dynamic_response_info.response[0] = 0xCA;
1290 dynamic_response_info.response[1] = 0x00;
1291 dynamic_response_info.response_n = 2;
1292 } break;
1293
1294 default: {
1295 // Never seen this command before
1296 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1297 Dbprintf("Received unknown command (len=%d):",len);
1298 Dbhexdump(len,receivedCmd,false);
1299 // Do not respond
1300 dynamic_response_info.response_n = 0;
1301 } break;
1302 }
1303
1304 if (dynamic_response_info.response_n > 0) {
1305 // Copy the CID from the reader query
1306 dynamic_response_info.response[1] = receivedCmd[1];
1307
1308 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1309 AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
1310 dynamic_response_info.response_n += 2;
1311
1312 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1313 Dbprintf("Error preparing tag response");
1314 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1315 break;
1316 }
1317 p_response = &dynamic_response_info;
1318 }
1319 }
1320
1321 // Count number of wakeups received after a halt
1322 if(order == 6 && lastorder == 5) { happened++; }
1323
1324 // Count number of other messages after a halt
1325 if(order != 6 && lastorder == 5) { happened2++; }
1326
1327 // comment this limit if you want to simulation longer
1328 if (!tracing) {
1329 Dbprintf("Trace Full. Simulation stopped.");
1330 break;
1331 }
1332 // comment this limit if you want to simulation longer
1333 if(cmdsRecvd > 999) {
1334 DbpString("1000 commands later...");
1335 break;
1336 }
1337 cmdsRecvd++;
1338
1339 if (p_response != NULL) {
1340 EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1341 // do the tracing for the previous reader request and this tag answer:
1342 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1343 GetParity(p_response->response, p_response->response_n, par);
1344
1345 EmLogTrace(Uart.output,
1346 Uart.len,
1347 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1348 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1349 Uart.parity,
1350 p_response->response,
1351 p_response->response_n,
1352 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1353 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1354 par);
1355 }
1356 }
1357
1358 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1359 set_tracing(FALSE);
1360 BigBuf_free_keep_EM();
1361 LED_A_OFF();
1362
1363 if(flags & FLAG_NR_AR_ATTACK && MF_DBGLEVEL >= 1) {
1364 for ( uint8_t i = 0; i < ATTACK_KEY_COUNT; i++) {
1365 if (ar_nr_collected[i] == 2) {
1366 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);
1367 Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
1368 ar_nr_resp[i].cuid, //UID
1369 ar_nr_resp[i].nonce, //NT
1370 ar_nr_resp[i].nr, //NR1
1371 ar_nr_resp[i].ar, //AR1
1372 ar_nr_resp[i].nr2, //NR2
1373 ar_nr_resp[i].ar2 //AR2
1374 );
1375 }
1376 }
1377 for ( uint8_t i = ATTACK_KEY_COUNT; i < ATTACK_KEY_COUNT*2; i++) {
1378 if (ar_nr_collected[i] == 2) {
1379 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);
1380 Dbprintf("../tools/mfkey/mfkey32v2 %08x %08x %08x %08x %08x %08x %08x",
1381 ar_nr_resp[i].cuid, //UID
1382 ar_nr_resp[i].nonce, //NT
1383 ar_nr_resp[i].nr, //NR1
1384 ar_nr_resp[i].ar, //AR1
1385 ar_nr_resp[i].nonce2,//NT2
1386 ar_nr_resp[i].nr2, //NR2
1387 ar_nr_resp[i].ar2 //AR2
1388 );
1389 }
1390 }
1391 }
1392
1393 if (MF_DBGLEVEL >= 4){
1394 Dbprintf("-[ Wake ups after halt [%d]", happened);
1395 Dbprintf("-[ Messages after halt [%d]", happened2);
1396 Dbprintf("-[ Num of received cmd [%d]", cmdsRecvd);
1397 }
1398 }
1399
1400 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1401 // of bits specified in the delay parameter.
1402 void PrepareDelayedTransfer(uint16_t delay) {
1403 delay &= 0x07;
1404 if (!delay) return;
1405
1406 uint8_t bitmask = 0;
1407 uint8_t bits_to_shift = 0;
1408 uint8_t bits_shifted = 0;
1409 uint16_t i = 0;
1410
1411 for (i = 0; i < delay; ++i)
1412 bitmask |= (0x01 << i);
1413
1414 ToSend[++ToSendMax] = 0x00;
1415
1416 for (i = 0; i < ToSendMax; ++i) {
1417 bits_to_shift = ToSend[i] & bitmask;
1418 ToSend[i] = ToSend[i] >> delay;
1419 ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1420 bits_shifted = bits_to_shift;
1421 }
1422 }
1423
1424
1425 //-------------------------------------------------------------------------------------
1426 // Transmit the command (to the tag) that was placed in ToSend[].
1427 // Parameter timing:
1428 // if NULL: transfer at next possible time, taking into account
1429 // request guard time and frame delay time
1430 // if == 0: transfer immediately and return time of transfer
1431 // if != 0: delay transfer until time specified
1432 //-------------------------------------------------------------------------------------
1433 static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing) {
1434 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1435
1436 uint32_t ThisTransferTime = 0;
1437
1438 if (timing) {
1439 if(*timing == 0) { // Measure time
1440 *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1441 } else {
1442 PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
1443 }
1444 if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
1445 while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
1446 LastTimeProxToAirStart = *timing;
1447 } else {
1448 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1449
1450 while(GetCountSspClk() < ThisTransferTime);
1451
1452 LastTimeProxToAirStart = ThisTransferTime;
1453 }
1454
1455 // clear TXRDY
1456 AT91C_BASE_SSC->SSC_THR = SEC_Y;
1457
1458 uint16_t c = 0;
1459 for(;;) {
1460 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1461 AT91C_BASE_SSC->SSC_THR = cmd[c];
1462 ++c;
1463 if(c >= len)
1464 break;
1465 }
1466 }
1467
1468 NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1469 }
1470
1471 //-----------------------------------------------------------------------------
1472 // Prepare reader command (in bits, support short frames) to send to FPGA
1473 //-----------------------------------------------------------------------------
1474 void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity) {
1475 int i, j;
1476 int last = 0;
1477 uint8_t b;
1478
1479 ToSendReset();
1480
1481 // Start of Communication (Seq. Z)
1482 ToSend[++ToSendMax] = SEC_Z;
1483 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1484
1485 size_t bytecount = nbytes(bits);
1486 // Generate send structure for the data bits
1487 for (i = 0; i < bytecount; i++) {
1488 // Get the current byte to send
1489 b = cmd[i];
1490 size_t bitsleft = MIN((bits-(i*8)),8);
1491
1492 for (j = 0; j < bitsleft; j++) {
1493 if (b & 1) {
1494 // Sequence X
1495 ToSend[++ToSendMax] = SEC_X;
1496 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1497 last = 1;
1498 } else {
1499 if (last == 0) {
1500 // Sequence Z
1501 ToSend[++ToSendMax] = SEC_Z;
1502 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1503 } else {
1504 // Sequence Y
1505 ToSend[++ToSendMax] = SEC_Y;
1506 last = 0;
1507 }
1508 }
1509 b >>= 1;
1510 }
1511
1512 // Only transmit parity bit if we transmitted a complete byte
1513 if (j == 8 && parity != NULL) {
1514 // Get the parity bit
1515 if (parity[i>>3] & (0x80 >> (i&0x0007))) {
1516 // Sequence X
1517 ToSend[++ToSendMax] = SEC_X;
1518 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1519 last = 1;
1520 } else {
1521 if (last == 0) {
1522 // Sequence Z
1523 ToSend[++ToSendMax] = SEC_Z;
1524 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1525 } else {
1526 // Sequence Y
1527 ToSend[++ToSendMax] = SEC_Y;
1528 last = 0;
1529 }
1530 }
1531 }
1532 }
1533
1534 // End of Communication: Logic 0 followed by Sequence Y
1535 if (last == 0) {
1536 // Sequence Z
1537 ToSend[++ToSendMax] = SEC_Z;
1538 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1539 } else {
1540 // Sequence Y
1541 ToSend[++ToSendMax] = SEC_Y;
1542 last = 0;
1543 }
1544 ToSend[++ToSendMax] = SEC_Y;
1545
1546 // Convert to length of command:
1547 ++ToSendMax;
1548 }
1549
1550 //-----------------------------------------------------------------------------
1551 // Prepare reader command to send to FPGA
1552 //-----------------------------------------------------------------------------
1553 void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity) {
1554 CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
1555 }
1556
1557 //-----------------------------------------------------------------------------
1558 // Wait for commands from reader
1559 // Stop when button is pressed (return 1) or field was gone (return 2)
1560 // Or return 0 when command is captured
1561 //-----------------------------------------------------------------------------
1562 static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity) {
1563 *len = 0;
1564
1565 uint32_t timer = 0, vtime = 0;
1566 int analogCnt = 0;
1567 int analogAVG = 0;
1568
1569 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1570 // only, since we are receiving, not transmitting).
1571 // Signal field is off with the appropriate LED
1572 LED_D_OFF();
1573 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1574
1575 // Set ADC to read field strength
1576 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1577 AT91C_BASE_ADC->ADC_MR =
1578 ADC_MODE_PRESCALE(63) |
1579 ADC_MODE_STARTUP_TIME(1) |
1580 ADC_MODE_SAMPLE_HOLD_TIME(15);
1581 AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1582 // start ADC
1583 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1584
1585 // Now run a 'software UART' on the stream of incoming samples.
1586 UartInit(received, parity);
1587
1588 // Clear RXRDY:
1589 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1590
1591 for(;;) {
1592 WDT_HIT();
1593
1594 if (BUTTON_PRESS()) return 1;
1595
1596 // test if the field exists
1597 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1598 analogCnt++;
1599 analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1600 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1601 if (analogCnt >= 32) {
1602 if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1603 vtime = GetTickCount();
1604 if (!timer) timer = vtime;
1605 // 50ms no field --> card to idle state
1606 if (vtime - timer > 50) return 2;
1607 } else
1608 if (timer) timer = 0;
1609 analogCnt = 0;
1610 analogAVG = 0;
1611 }
1612 }
1613
1614 // receive and test the miller decoding
1615 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1616 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1617 if(MillerDecoding(b, 0)) {
1618 *len = Uart.len;
1619 return 0;
1620 }
1621 }
1622 }
1623 }
1624
1625 int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded) {
1626 uint8_t b;
1627 uint16_t i = 0;
1628 uint32_t ThisTransferTime;
1629
1630 // Modulate Manchester
1631 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1632
1633 // include correction bit if necessary
1634 if (Uart.parityBits & 0x01) {
1635 correctionNeeded = TRUE;
1636 }
1637 // 1236, so correction bit needed
1638 i = (correctionNeeded) ? 0 : 1;
1639
1640 // clear receiving shift register and holding register
1641 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1642 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1643 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1644 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1645
1646 // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1647 for (uint8_t j = 0; j < 5; j++) { // allow timeout - better late than never
1648 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1649 if (AT91C_BASE_SSC->SSC_RHR) break;
1650 }
1651
1652 while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1653
1654 // Clear TXRDY:
1655 AT91C_BASE_SSC->SSC_THR = SEC_F;
1656
1657 // send cycle
1658 for(; i < respLen; ) {
1659 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1660 AT91C_BASE_SSC->SSC_THR = resp[i++];
1661 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1662 }
1663
1664 if(BUTTON_PRESS()) break;
1665 }
1666
1667 // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1668 uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3; // twich /8 ?? >>3,
1669 for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
1670 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1671 AT91C_BASE_SSC->SSC_THR = SEC_F;
1672 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1673 i++;
1674 }
1675 }
1676 LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
1677 return 0;
1678 }
1679
1680 int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
1681 Code4bitAnswerAsTag(resp);
1682 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1683 // do the tracing for the previous reader request and this tag answer:
1684 uint8_t par[1] = {0x00};
1685 GetParity(&resp, 1, par);
1686 EmLogTrace(Uart.output,
1687 Uart.len,
1688 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1689 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1690 Uart.parity,
1691 &resp,
1692 1,
1693 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1694 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1695 par);
1696 return res;
1697 }
1698
1699 int EmSend4bit(uint8_t resp){
1700 return EmSend4bitEx(resp, false);
1701 }
1702
1703 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){
1704 CodeIso14443aAsTagPar(resp, respLen, par);
1705 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1706 // do the tracing for the previous reader request and this tag answer:
1707 EmLogTrace(Uart.output,
1708 Uart.len,
1709 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1710 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1711 Uart.parity,
1712 resp,
1713 respLen,
1714 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1715 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1716 par);
1717 return res;
1718 }
1719
1720 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){
1721 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1722 GetParity(resp, respLen, par);
1723 return EmSendCmdExPar(resp, respLen, correctionNeeded, par);
1724 }
1725
1726 int EmSendCmd(uint8_t *resp, uint16_t respLen){
1727 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1728 GetParity(resp, respLen, par);
1729 return EmSendCmdExPar(resp, respLen, false, par);
1730 }
1731
1732 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
1733 return EmSendCmdExPar(resp, respLen, false, par);
1734 }
1735
1736 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
1737 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity)
1738 {
1739 // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1740 // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1741 // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1742 uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1743 uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1744 uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1745 reader_EndTime = tag_StartTime - exact_fdt;
1746 reader_StartTime = reader_EndTime - reader_modlen;
1747
1748 if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE))
1749 return FALSE;
1750 else
1751 return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
1752
1753 }
1754
1755 //-----------------------------------------------------------------------------
1756 // Wait a certain time for tag response
1757 // If a response is captured return TRUE
1758 // If it takes too long return FALSE
1759 //-----------------------------------------------------------------------------
1760 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset) {
1761 uint32_t c = 0x00;
1762
1763 // Set FPGA mode to "reader listen mode", no modulation (listen
1764 // only, since we are receiving, not transmitting).
1765 // Signal field is on with the appropriate LED
1766 LED_D_ON();
1767 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1768
1769 // Now get the answer from the card
1770 DemodInit(receivedResponse, receivedResponsePar);
1771
1772 // clear RXRDY:
1773 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1774
1775 for(;;) {
1776 WDT_HIT();
1777
1778 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1779 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1780 if(ManchesterDecoding(b, offset, 0)) {
1781 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1782 return TRUE;
1783 } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
1784 return FALSE;
1785 }
1786 }
1787 }
1788 }
1789
1790 void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing) {
1791
1792 CodeIso14443aBitsAsReaderPar(frame, bits, par);
1793 // Send command to tag
1794 TransmitFor14443a(ToSend, ToSendMax, timing);
1795 if(trigger) LED_A_ON();
1796
1797 LogTrace(frame, nbytes(bits), (LastTimeProxToAirStart<<4) + DELAY_ARM2AIR_AS_READER, ((LastTimeProxToAirStart + LastProxToAirDuration)<<4) + DELAY_ARM2AIR_AS_READER, par, TRUE);
1798 }
1799
1800 void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing) {
1801 ReaderTransmitBitsPar(frame, len*8, par, timing);
1802 }
1803
1804 void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing) {
1805 // Generate parity and redirect
1806 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1807 GetParity(frame, len/8, par);
1808 ReaderTransmitBitsPar(frame, len, par, timing);
1809 }
1810
1811 void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing) {
1812 // Generate parity and redirect
1813 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1814 GetParity(frame, len, par);
1815 ReaderTransmitBitsPar(frame, len*8, par, timing);
1816 }
1817
1818 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity) {
1819 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset))
1820 return FALSE;
1821 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1822 return Demod.len;
1823 }
1824
1825 int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity) {
1826 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0))
1827 return FALSE;
1828 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1829 return Demod.len;
1830 }
1831
1832 // performs iso14443a anticollision (optional) and card select procedure
1833 // fills the uid and cuid pointer unless NULL
1834 // fills the card info record unless NULL
1835 // if anticollision is false, then the UID must be provided in uid_ptr[]
1836 // and num_cascades must be set (1: 4 Byte UID, 2: 7 Byte UID, 3: 10 Byte UID)
1837 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) {
1838 uint8_t wupa[] = { ISO14443A_CMD_WUPA }; // 0x26 - ISO14443A_CMD_REQA 0x52 - ISO14443A_CMD_WUPA
1839 uint8_t sel_all[] = { ISO14443A_CMD_ANTICOLL_OR_SELECT,0x20 };
1840 uint8_t sel_uid[] = { ISO14443A_CMD_ANTICOLL_OR_SELECT,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1841 uint8_t rats[] = { ISO14443A_CMD_RATS,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1842 uint8_t resp[MAX_FRAME_SIZE] = {0}; // theoretically. A usual RATS will be much smaller
1843 uint8_t resp_par[MAX_PARITY_SIZE] = {0};
1844 byte_t uid_resp[4] = {0};
1845 size_t uid_resp_len = 0;
1846
1847 uint8_t sak = 0x04; // cascade uid
1848 int cascade_level = 0;
1849 int len;
1850
1851 // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1852 ReaderTransmitBitsPar(wupa, 7, NULL, NULL);
1853
1854 // Receive the ATQA
1855 if(!ReaderReceive(resp, resp_par)) return 0;
1856
1857 if(p_hi14a_card) {
1858 memcpy(p_hi14a_card->atqa, resp, 2);
1859 p_hi14a_card->uidlen = 0;
1860 memset(p_hi14a_card->uid,0,10);
1861 }
1862
1863 if (anticollision) {
1864 // clear uid
1865 if (uid_ptr)
1866 memset(uid_ptr,0,10);
1867 }
1868
1869 // check for proprietary anticollision:
1870 if ((resp[0] & 0x1F) == 0) return 3;
1871
1872 // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1873 // which case we need to make a cascade 2 request and select - this is a long UID
1874 // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1875 for(; sak & 0x04; cascade_level++) {
1876 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1877 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1878
1879 if (anticollision) {
1880 // SELECT_ALL
1881 ReaderTransmit(sel_all, sizeof(sel_all), NULL);
1882 if (!ReaderReceive(resp, resp_par)) return 0;
1883
1884 if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit
1885 memset(uid_resp, 0, 4);
1886 uint16_t uid_resp_bits = 0;
1887 uint16_t collision_answer_offset = 0;
1888 // anti-collision-loop:
1889 while (Demod.collisionPos) {
1890 Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1891 for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point
1892 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1893 uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8);
1894 }
1895 uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position
1896 uid_resp_bits++;
1897 // construct anticollosion command:
1898 sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits
1899 for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1900 sel_uid[2+i] = uid_resp[i];
1901 }
1902 collision_answer_offset = uid_resp_bits%8;
1903 ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1904 if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0;
1905 }
1906 // finally, add the last bits and BCC of the UID
1907 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1908 uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1909 uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1910 }
1911
1912 } else { // no collision, use the response to SELECT_ALL as current uid
1913 memcpy(uid_resp, resp, 4);
1914 }
1915
1916 } else {
1917 if (cascade_level < num_cascades - 1) {
1918 uid_resp[0] = 0x88;
1919 memcpy(uid_resp+1, uid_ptr+cascade_level*3, 3);
1920 } else {
1921 memcpy(uid_resp, uid_ptr+cascade_level*3, 4);
1922 }
1923 }
1924 uid_resp_len = 4;
1925
1926 // calculate crypto UID. Always use last 4 Bytes.
1927 if(cuid_ptr)
1928 *cuid_ptr = bytes_to_num(uid_resp, 4);
1929
1930 // Construct SELECT UID command
1931 sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1932 memcpy(sel_uid+2, uid_resp, 4); // the UID received during anticollision, or the provided UID
1933 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC
1934 AppendCrc14443a(sel_uid, 7); // calculate and add CRC
1935 ReaderTransmit(sel_uid, sizeof(sel_uid), NULL);
1936
1937 // Receive the SAK
1938 if (!ReaderReceive(resp, resp_par)) return 0;
1939
1940 sak = resp[0];
1941
1942 // Test if more parts of the uid are coming
1943 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
1944 // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
1945 // http://www.nxp.com/documents/application_note/AN10927.pdf
1946 uid_resp[0] = uid_resp[1];
1947 uid_resp[1] = uid_resp[2];
1948 uid_resp[2] = uid_resp[3];
1949 uid_resp_len = 3;
1950 }
1951
1952 if(uid_ptr && anticollision)
1953 memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
1954
1955 if(p_hi14a_card) {
1956 memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
1957 p_hi14a_card->uidlen += uid_resp_len;
1958 }
1959 }
1960
1961 if(p_hi14a_card) {
1962 p_hi14a_card->sak = sak;
1963 p_hi14a_card->ats_len = 0;
1964 }
1965
1966 // non iso14443a compliant tag
1967 if( (sak & 0x20) == 0) return 2;
1968
1969 // Request for answer to select
1970 AppendCrc14443a(rats, 2);
1971 ReaderTransmit(rats, sizeof(rats), NULL);
1972
1973 if (!(len = ReaderReceive(resp, resp_par))) return 0;
1974
1975 if(p_hi14a_card) {
1976 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
1977 p_hi14a_card->ats_len = len;
1978 }
1979
1980 // reset the PCB block number
1981 iso14_pcb_blocknum = 0;
1982
1983 // set default timeout based on ATS
1984 iso14a_set_ATS_timeout(resp);
1985
1986 return 1;
1987 }
1988
1989 void iso14443a_setup(uint8_t fpga_minor_mode) {
1990
1991 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1992 // Set up the synchronous serial port
1993 FpgaSetupSsc();
1994 // connect Demodulated Signal to ADC:
1995 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1996
1997 LED_D_OFF();
1998 // Signal field is on with the appropriate LED
1999 if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD ||
2000 fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN)
2001 LED_D_ON();
2002
2003 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
2004
2005 // Start the timer
2006 StartCountSspClk();
2007
2008 // Prepare the demodulation functions
2009 DemodReset();
2010 UartReset();
2011 NextTransferTime = 2 * DELAY_ARM2AIR_AS_READER;
2012 iso14a_set_timeout(20*106); // 20ms default
2013 }
2014
2015 int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
2016 uint8_t parity[MAX_PARITY_SIZE] = {0x00};
2017 uint8_t real_cmd[cmd_len+4];
2018 real_cmd[0] = 0x0a; //I-Block
2019 // put block number into the PCB
2020 real_cmd[0] |= iso14_pcb_blocknum;
2021 real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
2022 memcpy(real_cmd+2, cmd, cmd_len);
2023 AppendCrc14443a(real_cmd,cmd_len+2);
2024
2025 ReaderTransmit(real_cmd, cmd_len+4, NULL);
2026 size_t len = ReaderReceive(data, parity);
2027 //DATA LINK ERROR
2028 if (!len) return 0;
2029
2030 uint8_t *data_bytes = (uint8_t *) data;
2031
2032 // if we received an I- or R(ACK)-Block with a block number equal to the
2033 // current block number, toggle the current block number
2034 if (len >= 4 // PCB+CID+CRC = 4 bytes
2035 && ((data_bytes[0] & 0xC0) == 0 // I-Block
2036 || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
2037 && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
2038 {
2039 iso14_pcb_blocknum ^= 1;
2040 }
2041
2042 return len;
2043 }
2044
2045
2046 //-----------------------------------------------------------------------------
2047 // Read an ISO 14443a tag. Send out commands and store answers.
2048 //-----------------------------------------------------------------------------
2049 void ReaderIso14443a(UsbCommand *c) {
2050 iso14a_command_t param = c->arg[0];
2051 size_t len = c->arg[1] & 0xffff;
2052 size_t lenbits = c->arg[1] >> 16;
2053 uint32_t timeout = c->arg[2];
2054 uint8_t *cmd = c->d.asBytes;
2055 uint32_t arg0 = 0;
2056 byte_t buf[USB_CMD_DATA_SIZE] = {0x00};
2057 uint8_t par[MAX_PARITY_SIZE] = {0x00};
2058
2059 if (param & ISO14A_CONNECT)
2060 clear_trace();
2061
2062 set_tracing(TRUE);
2063
2064 if (param & ISO14A_REQUEST_TRIGGER)
2065 iso14a_set_trigger(TRUE);
2066
2067 if (param & ISO14A_CONNECT) {
2068 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
2069 if(!(param & ISO14A_NO_SELECT)) {
2070 iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
2071 arg0 = iso14443a_select_card(NULL,card,NULL, true, 0);
2072 cmd_send(CMD_ACK, arg0, card->uidlen, 0, buf, sizeof(iso14a_card_select_t));
2073 // if it fails, the cmdhf14a.c client quites.. however this one still executes.
2074 if ( arg0 == 0 ) return;
2075 }
2076 }
2077
2078 if (param & ISO14A_SET_TIMEOUT)
2079 iso14a_set_timeout(timeout);
2080
2081 if (param & ISO14A_APDU) {
2082 arg0 = iso14_apdu(cmd, len, buf);
2083 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2084 }
2085
2086 if (param & ISO14A_RAW) {
2087 if(param & ISO14A_APPEND_CRC) {
2088 if(param & ISO14A_TOPAZMODE) {
2089 AppendCrc14443b(cmd,len);
2090 } else {
2091 AppendCrc14443a(cmd,len);
2092 }
2093 len += 2;
2094 if (lenbits) lenbits += 16;
2095 }
2096 if(lenbits>0) { // want to send a specific number of bits (e.g. short commands)
2097 if(param & ISO14A_TOPAZMODE) {
2098 int bits_to_send = lenbits;
2099 uint16_t i = 0;
2100 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL); // first byte is always short (7bits) and no parity
2101 bits_to_send -= 7;
2102 while (bits_to_send > 0) {
2103 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL); // following bytes are 8 bit and no parity
2104 bits_to_send -= 8;
2105 }
2106 } else {
2107 GetParity(cmd, lenbits/8, par);
2108 ReaderTransmitBitsPar(cmd, lenbits, par, NULL); // bytes are 8 bit with odd parity
2109 }
2110 } else { // want to send complete bytes only
2111 if(param & ISO14A_TOPAZMODE) {
2112 uint16_t i = 0;
2113 ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL); // first byte: 7 bits, no paritiy
2114 while (i < len) {
2115 ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL); // following bytes: 8 bits, no paritiy
2116 }
2117 } else {
2118 ReaderTransmit(cmd,len, NULL); // 8 bits, odd parity
2119 }
2120 }
2121 arg0 = ReaderReceive(buf, par);
2122 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2123 }
2124
2125 if (param & ISO14A_REQUEST_TRIGGER)
2126 iso14a_set_trigger(FALSE);
2127
2128 if (param & ISO14A_NO_DISCONNECT)
2129 return;
2130
2131 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2132 set_tracing(FALSE);
2133 LEDsoff();
2134 }
2135
2136 // Determine the distance between two nonces.
2137 // Assume that the difference is small, but we don't know which is first.
2138 // Therefore try in alternating directions.
2139 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
2140
2141 if (nt1 == nt2) return 0;
2142
2143 uint32_t nttmp1 = nt1;
2144 uint32_t nttmp2 = nt2;
2145
2146 for (uint16_t i = 1; i < 32768/8; ++i) {
2147 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i;
2148 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -i;
2149
2150 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+1;
2151 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+1);
2152
2153 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+2;
2154 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+2);
2155
2156 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+3;
2157 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+3);
2158
2159 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+4;
2160 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+4);
2161
2162 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+5;
2163 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+5);
2164
2165 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+6;
2166 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+6);
2167
2168 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+7;
2169 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+7);
2170 }
2171 // either nt1 or nt2 are invalid nonces
2172 return(-99999);
2173 }
2174
2175 //-----------------------------------------------------------------------------
2176 // Recover several bits of the cypher stream. This implements (first stages of)
2177 // the algorithm described in "The Dark Side of Security by Obscurity and
2178 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
2179 // (article by Nicolas T. Courtois, 2009)
2180 //-----------------------------------------------------------------------------
2181
2182 void ReaderMifare(bool first_try, uint8_t block, uint8_t keytype ) {
2183
2184 uint8_t mf_auth[] = { keytype, block, 0x00, 0x00 };
2185 uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
2186 uint8_t uid[10] = {0,0,0,0,0,0,0,0,0,0};
2187 uint8_t par_list[8] = {0,0,0,0,0,0,0,0};
2188 uint8_t ks_list[8] = {0,0,0,0,0,0,0,0};
2189 uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE] = {0x00};
2190 uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
2191 uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
2192 byte_t nt_diff = 0;
2193 uint32_t nt = 0;
2194 uint32_t previous_nt = 0;
2195 uint32_t cuid = 0;
2196
2197 int32_t catch_up_cycles = 0;
2198 int32_t last_catch_up = 0;
2199 int32_t isOK = 0;
2200 int32_t nt_distance = 0;
2201
2202 uint16_t elapsed_prng_sequences = 1;
2203 uint16_t consecutive_resyncs = 0;
2204 uint16_t unexpected_random = 0;
2205 uint16_t sync_tries = 0;
2206
2207 // static variables here, is re-used in the next call
2208 static uint32_t nt_attacked = 0;
2209 static uint32_t sync_time = 0;
2210 static uint32_t sync_cycles = 0;
2211 static uint8_t par_low = 0;
2212 static uint8_t mf_nr_ar3 = 0;
2213
2214 #define PRNG_SEQUENCE_LENGTH (1 << 16)
2215 #define MAX_UNEXPECTED_RANDOM 4 // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up.
2216 #define MAX_SYNC_TRIES 32
2217
2218 AppendCrc14443a(mf_auth, 2);
2219
2220 BigBuf_free(); BigBuf_Clear_ext(false);
2221 clear_trace();
2222 set_tracing(TRUE);
2223 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2224
2225 sync_time = GetCountSspClk() & 0xfffffff8;
2226 sync_cycles = PRNG_SEQUENCE_LENGTH; // Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
2227 nt_attacked = 0;
2228
2229 if (MF_DBGLEVEL >= 4) Dbprintf("Mifare::Sync %08x", sync_time);
2230
2231 if (first_try) {
2232 mf_nr_ar3 = 0;
2233 par_low = 0;
2234 } else {
2235 // we were unsuccessful on a previous call.
2236 // Try another READER nonce (first 3 parity bits remain the same)
2237 ++mf_nr_ar3;
2238 mf_nr_ar[3] = mf_nr_ar3;
2239 par[0] = par_low;
2240 }
2241
2242 bool have_uid = FALSE;
2243 uint8_t cascade_levels = 0;
2244
2245 LED_C_ON();
2246 uint16_t i;
2247 for(i = 0; TRUE; ++i) {
2248
2249 WDT_HIT();
2250
2251 // Test if the action was cancelled
2252 if(BUTTON_PRESS()) {
2253 isOK = -1;
2254 break;
2255 }
2256
2257 // this part is from Piwi's faster nonce collecting part in Hardnested.
2258 if (!have_uid) { // need a full select cycle to get the uid first
2259 iso14a_card_select_t card_info;
2260 if(!iso14443a_select_card(uid, &card_info, &cuid, true, 0)) {
2261 if (MF_DBGLEVEL >= 4) Dbprintf("Mifare: Can't select card (ALL)");
2262 break;
2263 }
2264 switch (card_info.uidlen) {
2265 case 4 : cascade_levels = 1; break;
2266 case 7 : cascade_levels = 2; break;
2267 case 10: cascade_levels = 3; break;
2268 default: break;
2269 }
2270 have_uid = TRUE;
2271 } else { // no need for anticollision. We can directly select the card
2272 if(!iso14443a_select_card(uid, NULL, &cuid, false, cascade_levels)) {
2273 if (MF_DBGLEVEL >= 4) Dbprintf("Mifare: Can't select card (UID)");
2274 continue;
2275 }
2276 }
2277
2278 // Sending timeslot of ISO14443a frame
2279 sync_time = (sync_time & 0xfffffff8 ) + sync_cycles + catch_up_cycles;
2280 catch_up_cycles = 0;
2281
2282 // if we missed the sync time already, advance to the next nonce repeat
2283 while( GetCountSspClk() > sync_time) {
2284 ++elapsed_prng_sequences;
2285 sync_time = (sync_time & 0xfffffff8 ) + sync_cycles;
2286 }
2287
2288 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2289 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2290
2291 // Receive the (4 Byte) "random" nonce from TAG
2292 if (!ReaderReceive(receivedAnswer, receivedAnswerPar))
2293 continue;
2294
2295 previous_nt = nt;
2296 nt = bytes_to_num(receivedAnswer, 4);
2297
2298 // Transmit reader nonce with fake par
2299 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2300
2301 // we didn't calibrate our clock yet,
2302 // iceman: has to be calibrated every time.
2303 if (previous_nt && !nt_attacked) {
2304
2305 nt_distance = dist_nt(previous_nt, nt);
2306
2307 // if no distance between, then we are in sync.
2308 if (nt_distance == 0) {
2309 nt_attacked = nt;
2310 } else {
2311 if (nt_distance == -99999) { // invalid nonce received
2312 ++unexpected_random;
2313 if (unexpected_random > MAX_UNEXPECTED_RANDOM) {
2314 isOK = -3; // Card has an unpredictable PRNG. Give up
2315 break;
2316 } else {
2317 if (sync_cycles <= 0) sync_cycles += PRNG_SEQUENCE_LENGTH;
2318 LED_B_OFF();
2319 continue; // continue trying...
2320 }
2321 }
2322
2323 if (++sync_tries > MAX_SYNC_TRIES) {
2324 isOK = -4; // Card's PRNG runs at an unexpected frequency or resets unexpectedly
2325 break;
2326 }
2327
2328 sync_cycles = (sync_cycles - nt_distance)/elapsed_prng_sequences;
2329
2330 if (sync_cycles <= 0)
2331 sync_cycles += PRNG_SEQUENCE_LENGTH;
2332
2333 if (MF_DBGLEVEL >= 4)
2334 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);
2335
2336 LED_B_OFF();
2337 continue;
2338 }
2339 }
2340 LED_B_OFF();
2341
2342 if ( (nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
2343
2344 catch_up_cycles = ABS(dist_nt(nt_attacked, nt));
2345 if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one.
2346 catch_up_cycles = 0;
2347 continue;
2348 }
2349 // average?
2350 catch_up_cycles /= elapsed_prng_sequences;
2351
2352 if (catch_up_cycles == last_catch_up) {
2353 ++consecutive_resyncs;
2354 } else {
2355 last_catch_up = catch_up_cycles;
2356 consecutive_resyncs = 0;
2357 }
2358
2359 if (consecutive_resyncs < 3) {
2360 if (MF_DBGLEVEL >= 4)
2361 Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, catch_up_cycles, consecutive_resyncs);
2362 } else {
2363 sync_cycles += catch_up_cycles;
2364
2365 if (MF_DBGLEVEL >= 4)
2366 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);
2367
2368 last_catch_up = 0;
2369 catch_up_cycles = 0;
2370 consecutive_resyncs = 0;
2371 }
2372 continue;
2373 }
2374
2375 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2376 if (ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2377 catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2378
2379 if (nt_diff == 0)
2380 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
2381
2382 par_list[nt_diff] = SwapBits(par[0], 8);
2383 ks_list[nt_diff] = receivedAnswer[0] ^ 0x05; // xor with NACK value to get keystream
2384
2385 // Test if the information is complete
2386 if (nt_diff == 0x07) {
2387 isOK = 1;
2388 break;
2389 }
2390
2391 nt_diff = (nt_diff + 1) & 0x07;
2392 mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2393 par[0] = par_low;
2394
2395 } else {
2396 // No NACK.
2397 if (nt_diff == 0 && first_try) {
2398 par[0]++;
2399 if (par[0] == 0x00) { // tried all 256 possible parities without success. Card doesn't send NACK.
2400 isOK = -2;
2401 break;
2402 }
2403 } else {
2404 // Why this?
2405 par[0] = ((par[0] & 0x1F) + 1) | par_low;
2406 }
2407 }
2408
2409 // reset the resyncs since we got a complete transaction on right time.
2410 consecutive_resyncs = 0;
2411 } // end for loop
2412
2413 mf_nr_ar[3] &= 0x1F;
2414
2415 if (MF_DBGLEVEL >= 4) Dbprintf("Number of sent auth requestes: %u", i);
2416
2417 uint8_t buf[28] = {0x00};
2418 memset(buf, 0x00, sizeof(buf));
2419 num_to_bytes(cuid, 4, buf);
2420 num_to_bytes(nt, 4, buf + 4);
2421 memcpy(buf + 8, par_list, 8);
2422 memcpy(buf + 16, ks_list, 8);
2423 memcpy(buf + 24, mf_nr_ar, 4);
2424
2425 cmd_send(CMD_ACK, isOK, 0, 0, buf, sizeof(buf) );
2426
2427 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2428 LEDsoff();
2429 set_tracing(FALSE);
2430 }
2431
2432
2433 /**
2434 *MIFARE 1K simulate.
2435 *
2436 *@param flags :
2437 * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2438 * FLAG_4B_UID_IN_DATA - use 4-byte UID in the data-section
2439 * FLAG_7B_UID_IN_DATA - use 7-byte UID in the data-section
2440 * FLAG_10B_UID_IN_DATA - use 10-byte UID in the data-section
2441 * FLAG_UID_IN_EMUL - use 4-byte UID from emulator memory
2442 * FLAG_NR_AR_ATTACK - collect NR_AR responses for bruteforcing later
2443 *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2444 */
2445 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain) {
2446 int cardSTATE = MFEMUL_NOFIELD;
2447 int _UID_LEN = 0; // 4, 7, 10
2448 int vHf = 0; // in mV
2449 int res = 0;
2450 uint32_t selTimer = 0;
2451 uint32_t authTimer = 0;
2452 uint16_t len = 0;
2453 uint8_t cardWRBL = 0;
2454 uint8_t cardAUTHSC = 0;
2455 uint8_t cardAUTHKEY = 0xff; // no authentication
2456 uint32_t cuid = 0;
2457 uint32_t ans = 0;
2458 uint32_t cardINTREG = 0;
2459 uint8_t cardINTBLOCK = 0;
2460 struct Crypto1State mpcs = {0, 0};
2461 struct Crypto1State *pcs;
2462 pcs = &mpcs;
2463 uint32_t numReads = 0; // Counts numer of times reader read a block
2464 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00};
2465 uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
2466 uint8_t response[MAX_MIFARE_FRAME_SIZE] = {0x00};
2467 uint8_t response_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
2468
2469 uint8_t atqa[] = {0x04, 0x00}; // Mifare classic 1k
2470 uint8_t sak_4[] = {0x0C, 0x00, 0x00}; // CL1 - 4b uid
2471 uint8_t sak_7[] = {0x0C, 0x00, 0x00}; // CL2 - 7b uid
2472 uint8_t sak_10[] = {0x0C, 0x00, 0x00}; // CL3 - 10b uid
2473 // uint8_t sak[] = {0x09, 0x3f, 0xcc }; // Mifare Mini
2474
2475 uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2476 uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2477 uint8_t rUIDBCC3[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2478
2479 uint8_t rAUTH_NT[] = {0x01, 0x01, 0x01, 0x01}; // very random nonce
2480 // uint8_t rAUTH_NT[] = {0x55, 0x41, 0x49, 0x92};// nonce from nested? why this?
2481 uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2482
2483 // Here, we collect CUID, NT, NR, AR, CUID2, NT2, NR2, AR2
2484 // This can be used in a reader-only attack.
2485 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0,0};
2486 uint8_t ar_nr_collected = 0;
2487
2488 // Authenticate response - nonce
2489 uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2490 ar_nr_responses[1] = nonce;
2491
2492 // -- Determine the UID
2493 // Can be set from emulator memory or incoming data
2494 // Length: 4,7,or 10 bytes
2495 if ( (flags & FLAG_UID_IN_EMUL) == FLAG_UID_IN_EMUL)
2496 emlGetMemBt(datain, 0, 10); // load 10bytes from EMUL to the datain pointer. to be used below.
2497
2498 if ( (flags & FLAG_4B_UID_IN_DATA) == FLAG_4B_UID_IN_DATA) {
2499 memcpy(rUIDBCC1, datain, 4);
2500 _UID_LEN = 4;
2501 } else if ( (flags & FLAG_7B_UID_IN_DATA) == FLAG_7B_UID_IN_DATA) {
2502 memcpy(&rUIDBCC1[1], datain, 3);
2503 memcpy( rUIDBCC2, datain+3, 4);
2504 _UID_LEN = 7;
2505 } else if ( (flags & FLAG_10B_UID_IN_DATA) == FLAG_10B_UID_IN_DATA) {
2506 memcpy(&rUIDBCC1[1], datain, 3);
2507 memcpy(&rUIDBCC2[1], datain+3, 3);
2508 memcpy( rUIDBCC3, datain+6, 4);
2509 _UID_LEN = 10;
2510 }
2511
2512 switch (_UID_LEN) {
2513 case 4:
2514 sak_4[0] &= 0xFB;
2515 // save CUID
2516 ar_nr_responses[0] = cuid = bytes_to_num(rUIDBCC1, 4);
2517 // BCC
2518 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2519 if (MF_DBGLEVEL >= 2) {
2520 Dbprintf("4B UID: %02x%02x%02x%02x",
2521 rUIDBCC1[0],
2522 rUIDBCC1[1],
2523 rUIDBCC1[2],
2524 rUIDBCC1[3]
2525 );
2526 }
2527 break;
2528 case 7:
2529 atqa[0] |= 0x40;
2530 sak_7[0] &= 0xFB;
2531 // save CUID
2532 ar_nr_responses[0] = cuid = bytes_to_num(rUIDBCC2, 4);
2533 // CascadeTag, CT
2534 rUIDBCC1[0] = 0x88;
2535 // BCC
2536 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2537 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2538 if (MF_DBGLEVEL >= 2) {
2539 Dbprintf("7B UID: %02x %02x %02x %02x %02x %02x %02x",
2540 rUIDBCC1[1],
2541 rUIDBCC1[2],
2542 rUIDBCC1[3],
2543 rUIDBCC2[0],
2544 rUIDBCC2[1],
2545 rUIDBCC2[2],
2546 rUIDBCC2[3]
2547 );
2548 }
2549 break;
2550 case 10:
2551 atqa[0] |= 0x80;
2552 sak_10[0] &= 0xFB;
2553 // save CUID
2554 ar_nr_responses[0] = cuid = bytes_to_num(rUIDBCC3, 4);
2555 // CascadeTag, CT
2556 rUIDBCC1[0] = 0x88;
2557 rUIDBCC2[0] = 0x88;
2558 // BCC
2559 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2560 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2561 rUIDBCC3[4] = rUIDBCC3[0] ^ rUIDBCC3[1] ^ rUIDBCC3[2] ^ rUIDBCC3[3];
2562
2563 if (MF_DBGLEVEL >= 2) {
2564 Dbprintf("10B UID: %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
2565 rUIDBCC1[1],
2566 rUIDBCC1[2],
2567 rUIDBCC1[3],
2568 rUIDBCC2[1],
2569 rUIDBCC2[2],
2570 rUIDBCC2[3],
2571 rUIDBCC3[0],
2572 rUIDBCC3[1],
2573 rUIDBCC3[2],
2574 rUIDBCC3[3]
2575 );
2576 }
2577 break;
2578 default:
2579 break;
2580 }
2581 // calc some crcs
2582 ComputeCrc14443(CRC_14443_A, sak_4, 1, &sak_4[1], &sak_4[2]);
2583 ComputeCrc14443(CRC_14443_A, sak_7, 1, &sak_7[1], &sak_7[2]);
2584 ComputeCrc14443(CRC_14443_A, sak_10, 1, &sak_10[1], &sak_10[2]);
2585
2586 // We need to listen to the high-frequency, peak-detected path.
2587 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2588
2589 // free eventually allocated BigBuf memory but keep Emulator Memory
2590 BigBuf_free_keep_EM();
2591 clear_trace();
2592 set_tracing(TRUE);
2593
2594 bool finished = FALSE;
2595 while (!BUTTON_PRESS() && !finished && !usb_poll_validate_length()) {
2596 WDT_HIT();
2597
2598 // find reader field
2599 if (cardSTATE == MFEMUL_NOFIELD) {
2600 vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
2601 if (vHf > MF_MINFIELDV) {
2602 cardSTATE_TO_IDLE();
2603 LED_A_ON();
2604 }
2605 }
2606 if (cardSTATE == MFEMUL_NOFIELD) continue;
2607
2608 // Now, get data
2609 res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
2610 if (res == 2) { //Field is off!
2611 cardSTATE = MFEMUL_NOFIELD;
2612 LEDsoff();
2613 continue;
2614 } else if (res == 1) {
2615 break; // return value 1 means button press
2616 }
2617
2618 // REQ or WUP request in ANY state and WUP in HALTED state
2619 // this if-statement doesn't match the specification above. (iceman)
2620 if (len == 1 && ((receivedCmd[0] == ISO14443A_CMD_REQA && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == ISO14443A_CMD_WUPA)) {
2621 selTimer = GetTickCount();
2622 EmSendCmdEx(atqa, sizeof(atqa), (receivedCmd[0] == ISO14443A_CMD_WUPA));
2623 cardSTATE = MFEMUL_SELECT1;
2624 crypto1_destroy(pcs);
2625 cardAUTHKEY = 0xff;
2626 LEDsoff();
2627 nonce++;
2628 continue;
2629 }
2630
2631 switch (cardSTATE) {
2632 case MFEMUL_NOFIELD:
2633 case MFEMUL_HALTED:
2634 case MFEMUL_IDLE:{
2635 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2636 break;
2637 }
2638 case MFEMUL_SELECT1:{
2639 if (len == 2 && (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT && receivedCmd[1] == 0x20)) {
2640 if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received");
2641 EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2642 break;
2643 }
2644 // select card
2645 if (len == 9 &&
2646 ( receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT &&
2647 receivedCmd[1] == 0x70 &&
2648 memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2649
2650 // SAK 4b
2651 EmSendCmd(sak_4, sizeof(sak_4));
2652 switch(_UID_LEN){
2653 case 4:
2654 cardSTATE = MFEMUL_WORK;
2655 LED_B_ON();
2656 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2657 continue;
2658 case 7:
2659 case 10:
2660 cardSTATE = MFEMUL_SELECT2;
2661 continue;
2662 default:break;
2663 }
2664 } else {
2665 cardSTATE_TO_IDLE();
2666 }
2667 break;
2668 }
2669 case MFEMUL_SELECT2:{
2670 if (!len) {
2671 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2672 break;
2673 }
2674 if (len == 2 && (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2 && receivedCmd[1] == 0x20)) {
2675 EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2676 break;
2677 }
2678 if (len == 9 &&
2679 (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2 &&
2680 receivedCmd[1] == 0x70 &&
2681 memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0) ) {
2682
2683 EmSendCmd(sak_7, sizeof(sak_7));
2684 switch(_UID_LEN){
2685 case 7:
2686 cardSTATE = MFEMUL_WORK;
2687 LED_B_ON();
2688 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2689 continue;
2690 case 10:
2691 cardSTATE = MFEMUL_SELECT3;
2692 continue;
2693 default:break;
2694 }
2695 }
2696 cardSTATE_TO_IDLE();
2697 break;
2698 }
2699 case MFEMUL_SELECT3:{
2700 if (!len) {
2701 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2702 break;
2703 }
2704 if (len == 2 && (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_3 && receivedCmd[1] == 0x20)) {
2705 EmSendCmd(rUIDBCC3, sizeof(rUIDBCC3));
2706 break;
2707 }
2708 if (len == 9 &&
2709 (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_3 &&
2710 receivedCmd[1] == 0x70 &&
2711 memcmp(&receivedCmd[2], rUIDBCC3, 4) == 0) ) {
2712
2713 EmSendCmd(sak_10, sizeof(sak_10));
2714 cardSTATE = MFEMUL_WORK;
2715 LED_B_ON();
2716 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol3 time: %d", GetTickCount() - selTimer);
2717 break;
2718 }
2719 cardSTATE_TO_IDLE();
2720 break;
2721 }
2722 case MFEMUL_AUTH1:{
2723 if( len != 8) {
2724 cardSTATE_TO_IDLE();
2725 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2726 break;
2727 }
2728
2729 uint32_t nr = bytes_to_num(receivedCmd, 4);
2730 uint32_t ar = bytes_to_num(&receivedCmd[4], 4);
2731
2732 // Collect AR/NR
2733 // if(ar_nr_collected < 2 && cardAUTHSC == 2){
2734 if(ar_nr_collected < 2) {
2735 // if(ar_nr_responses[2] != nr) {
2736 ar_nr_responses[ar_nr_collected*4] = cuid;
2737 ar_nr_responses[ar_nr_collected*4+1] = nonce;
2738 ar_nr_responses[ar_nr_collected*4+2] = nr;
2739 ar_nr_responses[ar_nr_collected*4+3] = ar;
2740 ar_nr_collected++;
2741 // }
2742
2743 // Interactive mode flag, means we need to send ACK
2744 finished = ( ((flags & FLAG_INTERACTIVE) == FLAG_INTERACTIVE)&& ar_nr_collected == 2);
2745 }
2746 /*
2747 crypto1_word(pcs, ar , 1);
2748 cardRr = nr ^ crypto1_word(pcs, 0, 0);
2749
2750 test if auth OK
2751 if (cardRr != prng_successor(nonce, 64)){
2752
2753 if (MF_DBGLEVEL >= 4) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
2754 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2755 cardRr, prng_successor(nonce, 64));
2756 Shouldn't we respond anything here?
2757 Right now, we don't nack or anything, which causes the
2758 reader to do a WUPA after a while. /Martin
2759 -- which is the correct response. /piwi
2760 cardSTATE_TO_IDLE();
2761 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2762 break;
2763 }
2764 */
2765
2766 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2767 num_to_bytes(ans, 4, rAUTH_AT);
2768 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2769 LED_C_ON();
2770
2771 if (MF_DBGLEVEL >= 4) {
2772 Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2773 cardAUTHSC,
2774 cardAUTHKEY == 0 ? 'A' : 'B',
2775 GetTickCount() - authTimer
2776 );
2777 }
2778 cardSTATE = MFEMUL_WORK;
2779 break;
2780 }
2781 case MFEMUL_WORK:{
2782 if (len == 0) {
2783 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2784 break;
2785 }
2786 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2787
2788 if(encrypted_data)
2789 mf_crypto1_decrypt(pcs, receivedCmd, len);
2790
2791 if (len == 4 && (receivedCmd[0] == MIFARE_AUTH_KEYA ||
2792 receivedCmd[0] == MIFARE_AUTH_KEYB) ) {
2793
2794 authTimer = GetTickCount();
2795 cardAUTHSC = receivedCmd[1] / 4; // received block num
2796 cardAUTHKEY = receivedCmd[0] - 0x60; // & 1
2797 crypto1_destroy(pcs);
2798 crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2799
2800 if (!encrypted_data) {
2801 // first authentication
2802 crypto1_word(pcs, cuid ^ nonce, 0);// Update crypto state
2803 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2804
2805 if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2806
2807 } else {
2808 // nested authentication
2809 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2810 num_to_bytes(ans, 4, rAUTH_AT);
2811
2812 if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2813 }
2814
2815 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2816 cardSTATE = MFEMUL_AUTH1;
2817 break;
2818 }
2819
2820 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2821 // BUT... ACK --> NACK
2822 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2823 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2824 break;
2825 }
2826
2827 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2828 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2829 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2830 break;
2831 }
2832
2833 if(len != 4) {
2834 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2835 break;
2836 }
2837
2838 if ( receivedCmd[0] == ISO14443A_CMD_READBLOCK ||
2839 receivedCmd[0] == ISO14443A_CMD_WRITEBLOCK ||
2840 receivedCmd[0] == MIFARE_CMD_INC ||
2841 receivedCmd[0] == MIFARE_CMD_DEC ||
2842 receivedCmd[0] == MIFARE_CMD_RESTORE ||
2843 receivedCmd[0] == MIFARE_CMD_TRANSFER ) {
2844
2845 if (receivedCmd[1] >= 16 * 4) {
2846 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2847 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]);
2848 break;
2849 }
2850
2851 if (receivedCmd[1] / 4 != cardAUTHSC) {
2852 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2853 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);
2854 break;
2855 }
2856 }
2857 // read block
2858 if (receivedCmd[0] == ISO14443A_CMD_READBLOCK) {
2859 if (MF_DBGLEVEL >= 4) Dbprintf("Reader reading block %d (0x%02x)", receivedCmd[1], receivedCmd[1]);
2860
2861 emlGetMem(response, receivedCmd[1], 1);
2862 AppendCrc14443a(response, 16);
2863 mf_crypto1_encrypt(pcs, response, 18, response_par);
2864 EmSendCmdPar(response, 18, response_par);
2865 numReads++;
2866 if(exitAfterNReads > 0 && numReads >= exitAfterNReads) {
2867 Dbprintf("%d reads done, exiting", numReads);
2868 finished = true;
2869 }
2870 break;
2871 }
2872 // write block
2873 if (receivedCmd[0] == ISO14443A_CMD_WRITEBLOCK) {
2874 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)", receivedCmd[1], receivedCmd[1]);
2875 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2876 cardSTATE = MFEMUL_WRITEBL2;
2877 cardWRBL = receivedCmd[1];
2878 break;
2879 }
2880 // increment, decrement, restore
2881 if ( receivedCmd[0] == MIFARE_CMD_INC ||
2882 receivedCmd[0] == MIFARE_CMD_DEC ||
2883 receivedCmd[0] == MIFARE_CMD_RESTORE) {
2884
2885 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0], receivedCmd[1], receivedCmd[1]);
2886
2887 if (emlCheckValBl(receivedCmd[1])) {
2888 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2889 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2890 break;
2891 }
2892 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2893 if (receivedCmd[0] == MIFARE_CMD_INC) cardSTATE = MFEMUL_INTREG_INC;
2894 if (receivedCmd[0] == MIFARE_CMD_DEC) cardSTATE = MFEMUL_INTREG_DEC;
2895 if (receivedCmd[0] == MIFARE_CMD_RESTORE) cardSTATE = MFEMUL_INTREG_REST;
2896 cardWRBL = receivedCmd[1];
2897 break;
2898 }
2899 // transfer
2900 if (receivedCmd[0] == MIFARE_CMD_TRANSFER) {
2901 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)", receivedCmd[0], receivedCmd[1], receivedCmd[1]);
2902 if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2903 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2904 else
2905 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2906 break;
2907 }
2908 // halt
2909 if (receivedCmd[0] == ISO14443A_CMD_HALT && receivedCmd[1] == 0x00) {
2910 LED_B_OFF();
2911 LED_C_OFF();
2912 cardSTATE = MFEMUL_HALTED;
2913 if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer);
2914 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2915 break;
2916 }
2917 // RATS
2918 if (receivedCmd[0] == ISO14443A_CMD_RATS) {
2919 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2920 break;
2921 }
2922 // command not allowed
2923 if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking");
2924 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2925 break;
2926 }
2927 case MFEMUL_WRITEBL2:{
2928 if (len == 18) {
2929 mf_crypto1_decrypt(pcs, receivedCmd, len);
2930 emlSetMem(receivedCmd, cardWRBL, 1);
2931 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2932 cardSTATE = MFEMUL_WORK;
2933 } else {
2934 cardSTATE_TO_IDLE();
2935 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2936 }
2937 break;
2938 }
2939 case MFEMUL_INTREG_INC:{
2940 mf_crypto1_decrypt(pcs, receivedCmd, len);
2941 memcpy(&ans, receivedCmd, 4);
2942 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2943 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2944 cardSTATE_TO_IDLE();
2945 break;
2946 }
2947 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2948 cardINTREG = cardINTREG + ans;
2949 cardSTATE = MFEMUL_WORK;
2950 break;
2951 }
2952 case MFEMUL_INTREG_DEC:{
2953 mf_crypto1_decrypt(pcs, receivedCmd, len);
2954 memcpy(&ans, receivedCmd, 4);
2955 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2956 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2957 cardSTATE_TO_IDLE();
2958 break;
2959 }
2960 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2961 cardINTREG = cardINTREG - ans;
2962 cardSTATE = MFEMUL_WORK;
2963 break;
2964 }
2965 case MFEMUL_INTREG_REST:{
2966 mf_crypto1_decrypt(pcs, receivedCmd, len);
2967 memcpy(&ans, receivedCmd, 4);
2968 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2969 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2970 cardSTATE_TO_IDLE();
2971 break;
2972 }
2973 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2974 cardSTATE = MFEMUL_WORK;
2975 break;
2976 }
2977 }
2978 }
2979
2980 // Interactive mode flag, means we need to send ACK
2981 if((flags & FLAG_INTERACTIVE) == FLAG_INTERACTIVE) {
2982 // May just aswell send the collected ar_nr in the response aswell
2983 uint8_t len = ar_nr_collected * 4 * 4;
2984 cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, len, 0, &ar_nr_responses, len);
2985 }
2986
2987 if( ((flags & FLAG_NR_AR_ATTACK) == FLAG_NR_AR_ATTACK ) && MF_DBGLEVEL >= 1 ) {
2988 if(ar_nr_collected > 1 ) {
2989 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
2990 Dbprintf("../tools/mfkey/mfkey32v2.exe %08x %08x %08x %08x %08x %08x %08x",
2991 ar_nr_responses[0], // CUID
2992 ar_nr_responses[1], // NT1
2993 ar_nr_responses[2], // NR1
2994 ar_nr_responses[3], // AR1
2995 // ar_nr_responses[4], // CUID2
2996 ar_nr_responses[5], // NT2
2997 ar_nr_responses[6], // NR2
2998 ar_nr_responses[7] // AR2
2999 );
3000 } else {
3001 Dbprintf("Failed to obtain two AR/NR pairs!");
3002 if(ar_nr_collected == 1 ) {
3003 Dbprintf("Only got these: UID=%08x, nonce=%08x, NR1=%08x, AR1=%08x",
3004 ar_nr_responses[0], // CUID
3005 ar_nr_responses[1], // NT
3006 ar_nr_responses[2], // NR1
3007 ar_nr_responses[3] // AR1
3008 );
3009 }
3010 }
3011 }
3012 if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen());
3013
3014 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
3015 LEDsoff();
3016 set_tracing(FALSE);
3017 }
3018
3019
3020 //-----------------------------------------------------------------------------
3021 // MIFARE sniffer.
3022 //
3023 // if no activity for 2sec, it sends the collected data to the client.
3024 //-----------------------------------------------------------------------------
3025 // "hf mf sniff"
3026 void RAMFUNC SniffMifare(uint8_t param) {
3027
3028 LEDsoff();
3029
3030 // free eventually allocated BigBuf memory
3031 BigBuf_free(); BigBuf_Clear_ext(false);
3032 clear_trace();
3033 set_tracing(TRUE);
3034
3035 // The command (reader -> tag) that we're receiving.
3036 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00};
3037 uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
3038
3039 // The response (tag -> reader) that we're receiving.
3040 uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE] = {0x00};
3041 uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE] = {0x00};
3042
3043 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
3044
3045 // allocate the DMA buffer, used to stream samples from the FPGA
3046 // [iceman] is this sniffed data unsigned?
3047 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
3048 uint8_t *data = dmaBuf;
3049 uint8_t previous_data = 0;
3050 int maxDataLen = 0;
3051 int dataLen = 0;
3052 bool ReaderIsActive = FALSE;
3053 bool TagIsActive = FALSE;
3054
3055 // Set up the demodulator for tag -> reader responses.
3056 DemodInit(receivedResponse, receivedResponsePar);
3057
3058 // Set up the demodulator for the reader -> tag commands
3059 UartInit(receivedCmd, receivedCmdPar);
3060
3061 // Setup and start DMA.
3062 // set transfer address and number of bytes. Start transfer.
3063 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, DMA_BUFFER_SIZE) ){
3064 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
3065 return;
3066 }
3067
3068 LED_D_OFF();
3069
3070 MfSniffInit();
3071
3072 // And now we loop, receiving samples.
3073 for(uint32_t sniffCounter = 0;; ) {
3074
3075 LED_A_ON();
3076 WDT_HIT();
3077
3078 if(BUTTON_PRESS()) {
3079 DbpString("cancelled by button");
3080 break;
3081 }
3082
3083 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
3084 // check if a transaction is completed (timeout after 2000ms).
3085 // if yes, stop the DMA transfer and send what we have so far to the client
3086 if (MfSniffSend(2000)) {
3087 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
3088 sniffCounter = 0;
3089 data = dmaBuf;
3090 maxDataLen = 0;
3091 ReaderIsActive = FALSE;
3092 TagIsActive = FALSE;
3093 // Setup and start DMA. set transfer address and number of bytes. Start transfer.
3094 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, DMA_BUFFER_SIZE) ){
3095 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
3096 return;
3097 }
3098 }
3099 }
3100
3101 int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
3102 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
3103
3104 if (readBufDataP <= dmaBufDataP) // we are processing the same block of data which is currently being transferred
3105 dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
3106 else
3107 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
3108
3109 // test for length of buffer
3110 if(dataLen > maxDataLen) { // we are more behind than ever...
3111 maxDataLen = dataLen;
3112 if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
3113 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
3114 break;
3115 }
3116 }
3117 if(dataLen < 1) continue;
3118
3119 // primary buffer was stopped ( <-- we lost data!
3120 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
3121 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
3122 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
3123 Dbprintf("RxEmpty ERROR, data length:%d", dataLen); // temporary
3124 }
3125 // secondary buffer sets as primary, secondary buffer was stopped
3126 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
3127 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
3128 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
3129 }
3130
3131 LED_A_OFF();
3132
3133 if (sniffCounter & 0x01) {
3134
3135 // no need to try decoding tag data if the reader is sending
3136 if(!TagIsActive) {
3137 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
3138 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
3139 LED_C_INV();
3140
3141 if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
3142
3143 UartInit(receivedCmd, receivedCmdPar);
3144 DemodReset();
3145 }
3146 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
3147 }
3148
3149 // no need to try decoding tag data if the reader is sending
3150 if(!ReaderIsActive) {
3151 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
3152 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
3153 LED_C_INV();
3154
3155 if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
3156
3157 DemodReset();
3158 UartInit(receivedCmd, receivedCmdPar);
3159 }
3160 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
3161 }
3162 }
3163
3164 previous_data = *data;
3165 sniffCounter++;
3166 data++;
3167
3168 if(data == dmaBuf + DMA_BUFFER_SIZE)
3169 data = dmaBuf;
3170
3171 } // main cycle
3172
3173 if (MF_DBGLEVEL >= 1) Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
3174
3175 FpgaDisableSscDma();
3176 MfSniffEnd();
3177 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
3178 LEDsoff();
3179 set_tracing(FALSE);
3180 }
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