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1 //-----------------------------------------------------------------------------
2 // Merlok - June 2011, 2012
3 // Gerhard de Koning Gans - May 2008
4 // Hagen Fritsch - June 2010
5 //
6 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
7 // at your option, any later version. See the LICENSE.txt file for the text of
8 // the license.
9 //-----------------------------------------------------------------------------
10 // Routines to support ISO 14443 type A.
11 //-----------------------------------------------------------------------------
12
13 #include "proxmark3.h"
14 #include "apps.h"
15 #include "util.h"
16 #include "string.h"
17 #include "cmd.h"
18 #include "iso14443crc.h"
19 #include "iso14443a.h"
20 #include "iso14443b.h"
21 #include "crapto1.h"
22 #include "mifareutil.h"
23 #include "BigBuf.h"
24 #include "parity.h"
25
26 static uint32_t iso14a_timeout;
27 int rsamples = 0;
28 uint8_t trigger = 0;
29 // the block number for the ISO14443-4 PCB
30 static uint8_t iso14_pcb_blocknum = 0;
31
32 static uint8_t* free_buffer_pointer;
33
34 //
35 // ISO14443 timing:
36 //
37 // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
38 #define REQUEST_GUARD_TIME (7000/16 + 1)
39 // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
40 #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
41 // bool LastCommandWasRequest = FALSE;
42
43 //
44 // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
45 //
46 // When the PM acts as reader and is receiving tag data, it takes
47 // 3 ticks delay in the AD converter
48 // 16 ticks until the modulation detector completes and sets curbit
49 // 8 ticks until bit_to_arm is assigned from curbit
50 // 8*16 ticks for the transfer from FPGA to ARM
51 // 4*16 ticks until we measure the time
52 // - 8*16 ticks because we measure the time of the previous transfer
53 #define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
54
55 // When the PM acts as a reader and is sending, it takes
56 // 4*16 ticks until we can write data to the sending hold register
57 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
58 // 8 ticks until the first transfer starts
59 // 8 ticks later the FPGA samples the data
60 // 1 tick to assign mod_sig_coil
61 #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
62
63 // When the PM acts as tag and is receiving it takes
64 // 2 ticks delay in the RF part (for the first falling edge),
65 // 3 ticks for the A/D conversion,
66 // 8 ticks on average until the start of the SSC transfer,
67 // 8 ticks until the SSC samples the first data
68 // 7*16 ticks to complete the transfer from FPGA to ARM
69 // 8 ticks until the next ssp_clk rising edge
70 // 4*16 ticks until we measure the time
71 // - 8*16 ticks because we measure the time of the previous transfer
72 #define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
73
74 // The FPGA will report its internal sending delay in
75 uint16_t FpgaSendQueueDelay;
76 // the 5 first bits are the number of bits buffered in mod_sig_buf
77 // the last three bits are the remaining ticks/2 after the mod_sig_buf shift
78 #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
79
80 // When the PM acts as tag and is sending, it takes
81 // 4*16 ticks until we can write data to the sending hold register
82 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
83 // 8 ticks until the first transfer starts
84 // 8 ticks later the FPGA samples the data
85 // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
86 // + 1 tick to assign mod_sig_coil
87 #define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
88
89 // When the PM acts as sniffer and is receiving tag data, it takes
90 // 3 ticks A/D conversion
91 // 14 ticks to complete the modulation detection
92 // 8 ticks (on average) until the result is stored in to_arm
93 // + the delays in transferring data - which is the same for
94 // sniffing reader and tag data and therefore not relevant
95 #define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
96
97 // When the PM acts as sniffer and is receiving reader data, it takes
98 // 2 ticks delay in analogue RF receiver (for the falling edge of the
99 // start bit, which marks the start of the communication)
100 // 3 ticks A/D conversion
101 // 8 ticks on average until the data is stored in to_arm.
102 // + the delays in transferring data - which is the same for
103 // sniffing reader and tag data and therefore not relevant
104 #define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
105
106 //variables used for timing purposes:
107 //these are in ssp_clk cycles:
108 static uint32_t NextTransferTime;
109 static uint32_t LastTimeProxToAirStart;
110 static uint32_t LastProxToAirDuration;
111
112 // CARD TO READER - manchester
113 // Sequence D: 11110000 modulation with subcarrier during first half
114 // Sequence E: 00001111 modulation with subcarrier during second half
115 // Sequence F: 00000000 no modulation with subcarrier
116 // READER TO CARD - miller
117 // Sequence X: 00001100 drop after half a period
118 // Sequence Y: 00000000 no drop
119 // Sequence Z: 11000000 drop at start
120 #define SEC_D 0xf0
121 #define SEC_E 0x0f
122 #define SEC_F 0x00
123 #define SEC_X 0x0c
124 #define SEC_Y 0x00
125 #define SEC_Z 0xc0
126
127 void iso14a_set_trigger(bool enable) {
128 trigger = enable;
129 }
130
131 void iso14a_set_timeout(uint32_t timeout) {
132 iso14a_timeout = timeout;
133 if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
134 }
135
136 void iso14a_set_ATS_timeout(uint8_t *ats) {
137 uint8_t tb1;
138 uint8_t fwi;
139 uint32_t fwt;
140
141 if (ats[0] > 1) { // there is a format byte T0
142 if ((ats[1] & 0x20) == 0x20) { // there is an interface byte TB(1)
143
144 if ((ats[1] & 0x10) == 0x10) // there is an interface byte TA(1) preceding TB(1)
145 tb1 = ats[3];
146 else
147 tb1 = ats[2];
148
149 fwi = (tb1 & 0xf0) >> 4; // frame waiting indicator (FWI)
150 fwt = 256 * 16 * (1 << fwi); // frame waiting time (FWT) in 1/fc
151 //fwt = 4096 * (1 << fwi);
152
153 iso14a_set_timeout(fwt/(8*16));
154 //iso14a_set_timeout(fwt/128);
155 }
156 }
157 }
158
159 //-----------------------------------------------------------------------------
160 // Generate the parity value for a byte sequence
161 //
162 //-----------------------------------------------------------------------------
163 void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par) {
164 uint16_t paritybit_cnt = 0;
165 uint16_t paritybyte_cnt = 0;
166 uint8_t parityBits = 0;
167
168 for (uint16_t i = 0; i < iLen; i++) {
169 // Generate the parity bits
170 parityBits |= ((oddparity8(pbtCmd[i])) << (7-paritybit_cnt));
171 if (paritybit_cnt == 7) {
172 par[paritybyte_cnt] = parityBits; // save 8 Bits parity
173 parityBits = 0; // and advance to next Parity Byte
174 paritybyte_cnt++;
175 paritybit_cnt = 0;
176 } else {
177 paritybit_cnt++;
178 }
179 }
180
181 // save remaining parity bits
182 par[paritybyte_cnt] = parityBits;
183 }
184
185 void AppendCrc14443a(uint8_t* data, int len) {
186 ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
187 }
188
189 //=============================================================================
190 // ISO 14443 Type A - Miller decoder
191 //=============================================================================
192 // Basics:
193 // This decoder is used when the PM3 acts as a tag.
194 // The reader will generate "pauses" by temporarily switching of the field.
195 // At the PM3 antenna we will therefore measure a modulated antenna voltage.
196 // The FPGA does a comparison with a threshold and would deliver e.g.:
197 // ........ 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 .......
198 // The Miller decoder needs to identify the following sequences:
199 // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0")
200 // 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information")
201 // 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1")
202 // Note 1: the bitstream may start at any time. We therefore need to sync.
203 // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
204 //-----------------------------------------------------------------------------
205 static tUart Uart;
206
207 // Lookup-Table to decide if 4 raw bits are a modulation.
208 // We accept the following:
209 // 0001 - a 3 tick wide pause
210 // 0011 - a 2 tick wide pause, or a three tick wide pause shifted left
211 // 0111 - a 2 tick wide pause shifted left
212 // 1001 - a 2 tick wide pause shifted right
213 const bool Mod_Miller_LUT[] = {
214 FALSE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, TRUE,
215 FALSE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
216 };
217 #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4])
218 #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)])
219
220 void UartReset() {
221 Uart.state = STATE_UNSYNCD;
222 Uart.bitCount = 0;
223 Uart.len = 0; // number of decoded data bytes
224 Uart.parityLen = 0; // number of decoded parity bytes
225 Uart.shiftReg = 0; // shiftreg to hold decoded data bits
226 Uart.parityBits = 0; // holds 8 parity bits
227 Uart.startTime = 0;
228 Uart.endTime = 0;
229
230 Uart.byteCntMax = 0;
231 Uart.posCnt = 0;
232 Uart.syncBit = 9999;
233 }
234
235 void UartInit(uint8_t *data, uint8_t *parity) {
236 Uart.output = data;
237 Uart.parity = parity;
238 Uart.fourBits = 0x00000000; // clear the buffer for 4 Bits
239 UartReset();
240 }
241
242 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
243 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time) {
244 Uart.fourBits = (Uart.fourBits << 8) | bit;
245
246 if (Uart.state == STATE_UNSYNCD) { // not yet synced
247 Uart.syncBit = 9999; // not set
248
249 // 00x11111 2|3 ticks pause followed by 6|5 ticks unmodulated Sequence Z (a "0" or "start of communication")
250 // 11111111 8 ticks unmodulation Sequence Y (a "0" or "end of communication" or "no information")
251 // 111100x1 4 ticks unmodulated followed by 2|3 ticks pause Sequence X (a "1")
252
253 // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from
254 // Sequence X followed by Sequence Y followed by Sequence Z (111100x1 11111111 00x11111)
255 // we therefore look for a ...xx1111 11111111 00x11111xxxxxx... pattern
256 // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's)
257 //
258 #define ISO14443A_STARTBIT_MASK 0x07FFEF80 // mask is 00001111 11111111 1110 1111 10000000
259 #define ISO14443A_STARTBIT_PATTERN 0x07FF8F80 // pattern is 00001111 11111111 1000 1111 10000000
260
261 if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7;
262 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6;
263 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5;
264 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4;
265 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3;
266 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2;
267 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1;
268 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0;
269
270 if (Uart.syncBit != 9999) { // found a sync bit
271 Uart.startTime = non_real_time ? non_real_time : (GetCountSspClk() & 0xfffffff8);
272 Uart.startTime -= Uart.syncBit;
273 Uart.endTime = Uart.startTime;
274 Uart.state = STATE_START_OF_COMMUNICATION;
275 }
276 } else {
277
278 if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) {
279 if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation in both halves - error
280 UartReset();
281 } else { // Modulation in first half = Sequence Z = logic "0"
282 if (Uart.state == STATE_MILLER_X) { // error - must not follow after X
283 UartReset();
284 } else {
285 Uart.bitCount++;
286 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
287 Uart.state = STATE_MILLER_Z;
288 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
289 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
290 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
291 Uart.parityBits <<= 1; // make room for the parity bit
292 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
293 Uart.bitCount = 0;
294 Uart.shiftReg = 0;
295 if((Uart.len&0x0007) == 0) { // every 8 data bytes
296 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
297 Uart.parityBits = 0;
298 }
299 }
300 }
301 }
302 } else {
303 if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1"
304 Uart.bitCount++;
305 Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg
306 Uart.state = STATE_MILLER_X;
307 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
308 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
309 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
310 Uart.parityBits <<= 1; // make room for the new parity bit
311 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
312 Uart.bitCount = 0;
313 Uart.shiftReg = 0;
314 if ((Uart.len&0x0007) == 0) { // every 8 data bytes
315 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
316 Uart.parityBits = 0;
317 }
318 }
319 } else { // no modulation in both halves - Sequence Y
320 if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication
321 Uart.state = STATE_UNSYNCD;
322 Uart.bitCount--; // last "0" was part of EOC sequence
323 Uart.shiftReg <<= 1; // drop it
324 if(Uart.bitCount > 0) { // if we decoded some bits
325 Uart.shiftReg >>= (9 - Uart.bitCount); // right align them
326 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); // add last byte to the output
327 Uart.parityBits <<= 1; // add a (void) parity bit
328 Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align parity bits
329 Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store it
330 return TRUE;
331 } else if (Uart.len & 0x0007) { // there are some parity bits to store
332 Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align remaining parity bits
333 Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store them
334 }
335 if (Uart.len) {
336 return TRUE; // we are finished with decoding the raw data sequence
337 } else {
338 UartReset(); // Nothing received - start over
339 }
340 }
341 if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC
342 UartReset();
343 } else { // a logic "0"
344 Uart.bitCount++;
345 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
346 Uart.state = STATE_MILLER_Y;
347 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
348 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
349 Uart.parityBits <<= 1; // make room for the parity bit
350 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
351 Uart.bitCount = 0;
352 Uart.shiftReg = 0;
353 if ((Uart.len&0x0007) == 0) { // every 8 data bytes
354 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
355 Uart.parityBits = 0;
356 }
357 }
358 }
359 }
360 }
361 }
362 return FALSE; // not finished yet, need more data
363 }
364
365 //=============================================================================
366 // ISO 14443 Type A - Manchester decoder
367 //=============================================================================
368 // Basics:
369 // This decoder is used when the PM3 acts as a reader.
370 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
371 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
372 // ........ 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 .......
373 // The Manchester decoder needs to identify the following sequences:
374 // 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication")
375 // 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0
376 // 8 ticks unmodulated: Sequence F = end of communication
377 // 8 ticks modulated: A collision. Save the collision position and treat as Sequence D
378 // Note 1: the bitstream may start at any time. We therefore need to sync.
379 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
380 static tDemod Demod;
381
382 // Lookup-Table to decide if 4 raw bits are a modulation.
383 // We accept three or four "1" in any position
384 const bool Mod_Manchester_LUT[] = {
385 FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
386 FALSE, FALSE, FALSE, TRUE, FALSE, TRUE, TRUE, TRUE
387 };
388
389 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
390 #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
391
392 void DemodReset() {
393 Demod.state = DEMOD_UNSYNCD;
394 Demod.len = 0; // number of decoded data bytes
395 Demod.parityLen = 0;
396 Demod.shiftReg = 0; // shiftreg to hold decoded data bits
397 Demod.parityBits = 0; //
398 Demod.collisionPos = 0; // Position of collision bit
399 Demod.twoBits = 0xffff; // buffer for 2 Bits
400 Demod.highCnt = 0;
401 Demod.startTime = 0;
402 Demod.endTime = 0;
403 Demod.bitCount = 0;
404 Demod.syncBit = 0xFFFF;
405 Demod.samples = 0;
406 }
407
408 void DemodInit(uint8_t *data, uint8_t *parity) {
409 Demod.output = data;
410 Demod.parity = parity;
411 DemodReset();
412 }
413
414 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
415 static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time) {
416 Demod.twoBits = (Demod.twoBits << 8) | bit;
417
418 if (Demod.state == DEMOD_UNSYNCD) {
419
420 if (Demod.highCnt < 2) { // wait for a stable unmodulated signal
421 if (Demod.twoBits == 0x0000) {
422 Demod.highCnt++;
423 } else {
424 Demod.highCnt = 0;
425 }
426 } else {
427 Demod.syncBit = 0xFFFF; // not set
428 if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
429 else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
430 else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
431 else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
432 else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
433 else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
434 else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
435 else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
436 if (Demod.syncBit != 0xFFFF) {
437 Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
438 Demod.startTime -= Demod.syncBit;
439 Demod.bitCount = offset; // number of decoded data bits
440 Demod.state = DEMOD_MANCHESTER_DATA;
441 }
442 }
443 } else {
444
445 if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half
446 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... and in second half = collision
447 if (!Demod.collisionPos) {
448 Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
449 }
450 } // modulation in first half only - Sequence D = 1
451 Demod.bitCount++;
452 Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg
453 if(Demod.bitCount == 9) { // if we decoded a full byte (including parity)
454 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
455 Demod.parityBits <<= 1; // make room for the parity bit
456 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
457 Demod.bitCount = 0;
458 Demod.shiftReg = 0;
459 if((Demod.len&0x0007) == 0) { // every 8 data bytes
460 Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits
461 Demod.parityBits = 0;
462 }
463 }
464 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
465 } else { // no modulation in first half
466 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // and modulation in second half = Sequence E = 0
467 Demod.bitCount++;
468 Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg
469 if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity)
470 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
471 Demod.parityBits <<= 1; // make room for the new parity bit
472 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
473 Demod.bitCount = 0;
474 Demod.shiftReg = 0;
475 if ((Demod.len&0x0007) == 0) { // every 8 data bytes
476 Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits1
477 Demod.parityBits = 0;
478 }
479 }
480 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
481 } else { // no modulation in both halves - End of communication
482 if(Demod.bitCount > 0) { // there are some remaining data bits
483 Demod.shiftReg >>= (9 - Demod.bitCount); // right align the decoded bits
484 Demod.output[Demod.len++] = Demod.shiftReg & 0xff; // and add them to the output
485 Demod.parityBits <<= 1; // add a (void) parity bit
486 Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
487 Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
488 return TRUE;
489 } else if (Demod.len & 0x0007) { // there are some parity bits to store
490 Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
491 Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
492 }
493 if (Demod.len) {
494 return TRUE; // we are finished with decoding the raw data sequence
495 } else { // nothing received. Start over
496 DemodReset();
497 }
498 }
499 }
500 }
501 return FALSE; // not finished yet, need more data
502 }
503
504 //=============================================================================
505 // Finally, a `sniffer' for ISO 14443 Type A
506 // Both sides of communication!
507 //=============================================================================
508
509 //-----------------------------------------------------------------------------
510 // Record the sequence of commands sent by the reader to the tag, with
511 // triggering so that we start recording at the point that the tag is moved
512 // near the reader.
513 // "hf 14a sniff"
514 //-----------------------------------------------------------------------------
515 void RAMFUNC SniffIso14443a(uint8_t param) {
516 // param:
517 // bit 0 - trigger from first card answer
518 // bit 1 - trigger from first reader 7-bit request
519 LEDsoff();
520
521 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
522
523 // Allocate memory from BigBuf for some buffers
524 // free all previous allocations first
525 BigBuf_free(); BigBuf_Clear_ext(false);
526 clear_trace();
527 set_tracing(TRUE);
528
529 // The command (reader -> tag) that we're receiving.
530 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
531 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
532
533 // The response (tag -> reader) that we're receiving.
534 uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
535 uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE);
536
537 // The DMA buffer, used to stream samples from the FPGA
538 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
539
540 uint8_t *data = dmaBuf;
541 uint8_t previous_data = 0;
542 int maxDataLen = 0;
543 int dataLen = 0;
544 bool TagIsActive = FALSE;
545 bool ReaderIsActive = FALSE;
546
547 // Set up the demodulator for tag -> reader responses.
548 DemodInit(receivedResponse, receivedResponsePar);
549
550 // Set up the demodulator for the reader -> tag commands
551 UartInit(receivedCmd, receivedCmdPar);
552
553 // Setup and start DMA.
554 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, DMA_BUFFER_SIZE) ){
555 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
556 return;
557 }
558
559 // We won't start recording the frames that we acquire until we trigger;
560 // a good trigger condition to get started is probably when we see a
561 // response from the tag.
562 // triggered == FALSE -- to wait first for card
563 bool triggered = !(param & 0x03);
564
565 // And now we loop, receiving samples.
566 for(uint32_t rsamples = 0; TRUE; ) {
567
568 if(BUTTON_PRESS()) {
569 DbpString("cancelled by button");
570 break;
571 }
572
573 LED_A_ON();
574 WDT_HIT();
575
576 int register readBufDataP = data - dmaBuf;
577 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
578 if (readBufDataP <= dmaBufDataP){
579 dataLen = dmaBufDataP - readBufDataP;
580 } else {
581 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
582 }
583 // test for length of buffer
584 if(dataLen > maxDataLen) {
585 maxDataLen = dataLen;
586 if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
587 Dbprintf("blew circular buffer! dataLen=%d", dataLen);
588 break;
589 }
590 }
591 if(dataLen < 1) continue;
592
593 // primary buffer was stopped( <-- we lost data!
594 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
595 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
596 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
597 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
598 }
599 // secondary buffer sets as primary, secondary buffer was stopped
600 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
601 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
602 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
603 }
604
605 LED_A_OFF();
606
607 if (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder
608
609 if(!TagIsActive) { // no need to try decoding reader data if the tag is sending
610 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
611 if (MillerDecoding(readerdata, (rsamples-1)*4)) {
612 LED_C_ON();
613
614 // check - if there is a short 7bit request from reader
615 if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
616
617 if(triggered) {
618 if (!LogTrace(receivedCmd,
619 Uart.len,
620 Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
621 Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
622 Uart.parity,
623 TRUE)) break;
624 }
625 /* And ready to receive another command. */
626 UartReset();
627 /* And also reset the demod code, which might have been */
628 /* false-triggered by the commands from the reader. */
629 DemodReset();
630 LED_B_OFF();
631 }
632 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
633 }
634
635 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time
636 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
637 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
638 LED_B_ON();
639
640 if (!LogTrace(receivedResponse,
641 Demod.len,
642 Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
643 Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
644 Demod.parity,
645 FALSE)) break;
646
647 if ((!triggered) && (param & 0x01)) triggered = TRUE;
648
649 // And ready to receive another response.
650 DemodReset();
651 // And reset the Miller decoder including itS (now outdated) input buffer
652 UartInit(receivedCmd, receivedCmdPar);
653 LED_C_OFF();
654 }
655 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
656 }
657 }
658
659 previous_data = *data;
660 rsamples++;
661 data++;
662 if(data == dmaBuf + DMA_BUFFER_SIZE) {
663 data = dmaBuf;
664 }
665 } // main cycle
666
667 if (MF_DBGLEVEL >= 1) {
668 Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
669 Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
670 }
671 FpgaDisableSscDma();
672 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
673 LEDsoff();
674 set_tracing(FALSE);
675 }
676
677 //-----------------------------------------------------------------------------
678 // Prepare tag messages
679 //-----------------------------------------------------------------------------
680 static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity) {
681 ToSendReset();
682
683 // Correction bit, might be removed when not needed
684 ToSendStuffBit(0);
685 ToSendStuffBit(0);
686 ToSendStuffBit(0);
687 ToSendStuffBit(0);
688 ToSendStuffBit(1); // 1
689 ToSendStuffBit(0);
690 ToSendStuffBit(0);
691 ToSendStuffBit(0);
692
693 // Send startbit
694 ToSend[++ToSendMax] = SEC_D;
695 LastProxToAirDuration = 8 * ToSendMax - 4;
696
697 for(uint16_t i = 0; i < len; i++) {
698 uint8_t b = cmd[i];
699
700 // Data bits
701 for(uint16_t j = 0; j < 8; j++) {
702 if(b & 1) {
703 ToSend[++ToSendMax] = SEC_D;
704 } else {
705 ToSend[++ToSendMax] = SEC_E;
706 }
707 b >>= 1;
708 }
709
710 // Get the parity bit
711 if (parity[i>>3] & (0x80>>(i&0x0007))) {
712 ToSend[++ToSendMax] = SEC_D;
713 LastProxToAirDuration = 8 * ToSendMax - 4;
714 } else {
715 ToSend[++ToSendMax] = SEC_E;
716 LastProxToAirDuration = 8 * ToSendMax;
717 }
718 }
719
720 // Send stopbit
721 ToSend[++ToSendMax] = SEC_F;
722
723 // Convert from last byte pos to length
724 ++ToSendMax;
725 }
726
727 static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len) {
728 uint8_t par[MAX_PARITY_SIZE] = {0};
729 GetParity(cmd, len, par);
730 CodeIso14443aAsTagPar(cmd, len, par);
731 }
732
733 static void Code4bitAnswerAsTag(uint8_t cmd) {
734 uint8_t b = cmd;
735
736 ToSendReset();
737
738 // Correction bit, might be removed when not needed
739 ToSendStuffBit(0);
740 ToSendStuffBit(0);
741 ToSendStuffBit(0);
742 ToSendStuffBit(0);
743 ToSendStuffBit(1); // 1
744 ToSendStuffBit(0);
745 ToSendStuffBit(0);
746 ToSendStuffBit(0);
747
748 // Send startbit
749 ToSend[++ToSendMax] = SEC_D;
750
751 for(uint8_t i = 0; i < 4; i++) {
752 if(b & 1) {
753 ToSend[++ToSendMax] = SEC_D;
754 LastProxToAirDuration = 8 * ToSendMax - 4;
755 } else {
756 ToSend[++ToSendMax] = SEC_E;
757 LastProxToAirDuration = 8 * ToSendMax;
758 }
759 b >>= 1;
760 }
761
762 // Send stopbit
763 ToSend[++ToSendMax] = SEC_F;
764
765 // Convert from last byte pos to length
766 ToSendMax++;
767 }
768
769 //-----------------------------------------------------------------------------
770 // Wait for commands from reader
771 // Stop when button is pressed
772 // Or return TRUE when command is captured
773 //-----------------------------------------------------------------------------
774 static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len) {
775 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
776 // only, since we are receiving, not transmitting).
777 // Signal field is off with the appropriate LED
778 LED_D_OFF();
779 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
780
781 // Now run a `software UART` on the stream of incoming samples.
782 UartInit(received, parity);
783
784 // clear RXRDY:
785 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
786
787 for(;;) {
788 WDT_HIT();
789
790 if(BUTTON_PRESS()) return FALSE;
791
792 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
793 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
794 if(MillerDecoding(b, 0)) {
795 *len = Uart.len;
796 return TRUE;
797 }
798 }
799 }
800 }
801
802 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
803 // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
804 // This will need the following byte array for a modulation sequence
805 // 144 data bits (18 * 8)
806 // 18 parity bits
807 // 2 Start and stop
808 // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA)
809 // 1 just for the case
810 // ----------- +
811 // 166 bytes, since every bit that needs to be send costs us a byte
812 //
813 // Prepare the tag modulation bits from the message
814 CodeIso14443aAsTag(response_info->response,response_info->response_n);
815
816 // Make sure we do not exceed the free buffer space
817 if (ToSendMax > max_buffer_size) {
818 Dbprintf("Out of memory, when modulating bits for tag answer:");
819 Dbhexdump(response_info->response_n,response_info->response,false);
820 return FALSE;
821 }
822
823 // Copy the byte array, used for this modulation to the buffer position
824 memcpy(response_info->modulation,ToSend,ToSendMax);
825
826 // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
827 response_info->modulation_n = ToSendMax;
828 response_info->ProxToAirDuration = LastProxToAirDuration;
829 return TRUE;
830 }
831
832 // "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit.
833 // Coded responses need one byte per bit to transfer (data, parity, start, stop, correction)
834 // 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits
835 // -> need 273 bytes buffer
836 // 44 * 8 data bits, 44 * 1 parity bits, 9 start bits, 9 stop bits, 9 correction bits --370
837 // 47 * 8 data bits, 47 * 1 parity bits, 10 start bits, 10 stop bits, 10 correction bits
838 #define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 453
839
840 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
841 // Retrieve and store the current buffer index
842 response_info->modulation = free_buffer_pointer;
843
844 // Determine the maximum size we can use from our buffer
845 size_t max_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE;
846
847 // Forward the prepare tag modulation function to the inner function
848 if (prepare_tag_modulation(response_info, max_buffer_size)) {
849 // Update the free buffer offset
850 free_buffer_pointer += ToSendMax;
851 return true;
852 } else {
853 return false;
854 }
855 }
856
857 //-----------------------------------------------------------------------------
858 // Main loop of simulated tag: receive commands from reader, decide what
859 // response to send, and send it.
860 //-----------------------------------------------------------------------------
861 void SimulateIso14443aTag(int tagType, int flags, byte_t* data) {
862
863 //Here, we collect CUID, NT, NR, AR, CUID, NT2, NR2, AR2
864 // This can be used in a reader-only attack.
865 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0,0,0};
866 uint8_t ar_nr_collected = 0;
867 uint8_t sak = 0;
868 uint32_t cuid = 0;
869 uint32_t nonce = 0;
870
871 // PACK response to PWD AUTH for EV1/NTAG
872 uint8_t response8[4] = {0,0,0,0};
873 // Counter for EV1/NTAG
874 uint32_t counters[] = {0,0,0};
875
876 // The first response contains the ATQA (note: bytes are transmitted in reverse order).
877 uint8_t response1[] = {0,0};
878
879 switch (tagType) {
880 case 1: { // MIFARE Classic 1k
881 response1[0] = 0x04;
882 sak = 0x08;
883 } break;
884 case 2: { // MIFARE Ultralight
885 response1[0] = 0x44;
886 sak = 0x00;
887 } break;
888 case 3: { // MIFARE DESFire
889 response1[0] = 0x04;
890 response1[1] = 0x03;
891 sak = 0x20;
892 } break;
893 case 4: { // ISO/IEC 14443-4 - javacard (JCOP)
894 response1[0] = 0x04;
895 sak = 0x28;
896 } break;
897 case 5: { // MIFARE TNP3XXX
898 response1[0] = 0x01;
899 response1[1] = 0x0f;
900 sak = 0x01;
901 } break;
902 case 6: { // MIFARE Mini 320b
903 response1[0] = 0x44;
904 sak = 0x09;
905 } break;
906 case 7: { // NTAG
907 response1[0] = 0x44;
908 sak = 0x00;
909 // PACK
910 response8[0] = 0x80;
911 response8[1] = 0x80;
912 ComputeCrc14443(CRC_14443_A, response8, 2, &response8[2], &response8[3]);
913 // uid not supplied then get from emulator memory
914 if (data[0]==0) {
915 uint16_t start = 4 * (0+12);
916 uint8_t emdata[8];
917 emlGetMemBt( emdata, start, sizeof(emdata));
918 memcpy(data, emdata, 3); //uid bytes 0-2
919 memcpy(data+3, emdata+4, 4); //uid bytes 3-7
920 flags |= FLAG_7B_UID_IN_DATA;
921 }
922 } break;
923 default: {
924 Dbprintf("Error: unkown tagtype (%d)",tagType);
925 return;
926 } break;
927 }
928
929 // The second response contains the (mandatory) first 24 bits of the UID
930 uint8_t response2[5] = {0x00};
931
932 // For UID size 7,
933 uint8_t response2a[5] = {0x00};
934
935 if ( (flags & FLAG_7B_UID_IN_DATA) == FLAG_7B_UID_IN_DATA ) {
936 response2[0] = 0x88; // Cascade Tag marker
937 response2[1] = data[0];
938 response2[2] = data[1];
939 response2[3] = data[2];
940
941 response2a[0] = data[3];
942 response2a[1] = data[4];
943 response2a[2] = data[5];
944 response2a[3] = data[6]; //??
945 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
946
947 // Configure the ATQA and SAK accordingly
948 response1[0] |= 0x40;
949 sak |= 0x04;
950
951 cuid = bytes_to_num(data+3, 4);
952 } else {
953 memcpy(response2, data, 4);
954 // Configure the ATQA and SAK accordingly
955 response1[0] &= 0xBF;
956 sak &= 0xFB;
957 cuid = bytes_to_num(data, 4);
958 }
959
960 // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
961 response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
962
963 // Prepare the mandatory SAK (for 4 and 7 byte UID)
964 uint8_t response3[3] = {sak, 0x00, 0x00};
965 ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
966
967 // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
968 uint8_t response3a[3] = {0x00};
969 response3a[0] = sak & 0xFB;
970 ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
971
972 uint8_t response5[] = { 0x01, 0x01, 0x01, 0x01 }; // Very random tag nonce
973 uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS:
974 // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
975 // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
976 // 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)
977 // TC(1) = 0x02: CID supported, NAD not supported
978 ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
979
980 // the randon nonce
981 nonce = bytes_to_num(response5, 4);
982
983 // Prepare GET_VERSION (different for UL EV-1 / NTAG)
984 //uint8_t response7_EV1[] = {0x00, 0x04, 0x03, 0x01, 0x01, 0x00, 0x0b, 0x03, 0xfd, 0xf7}; //EV1 48bytes VERSION.
985 //uint8_t response7_NTAG[] = {0x00, 0x04, 0x04, 0x02, 0x01, 0x00, 0x11, 0x03, 0x01, 0x9e}; //NTAG 215
986 // Prepare CHK_TEARING
987 //uint8_t response9[] = {0xBD,0x90,0x3f};
988
989 #define TAG_RESPONSE_COUNT 10
990 tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
991 { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type
992 { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid
993 { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked
994 { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1
995 { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2
996 { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce)
997 { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS
998
999 { .response = response8, .response_n = sizeof(response8) } // EV1/NTAG PACK response
1000 };
1001 //{ .response = response7_NTAG, .response_n = sizeof(response7_NTAG)}, // EV1/NTAG GET_VERSION response
1002 //{ .response = response9, .response_n = sizeof(response9) } // EV1/NTAG CHK_TEAR response
1003
1004
1005 // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
1006 // Such a response is less time critical, so we can prepare them on the fly
1007 #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
1008 #define DYNAMIC_MODULATION_BUFFER_SIZE 512
1009 uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
1010 uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
1011 tag_response_info_t dynamic_response_info = {
1012 .response = dynamic_response_buffer,
1013 .response_n = 0,
1014 .modulation = dynamic_modulation_buffer,
1015 .modulation_n = 0
1016 };
1017
1018 // We need to listen to the high-frequency, peak-detected path.
1019 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1020
1021 BigBuf_free_keep_EM();
1022 clear_trace();
1023 set_tracing(TRUE);
1024
1025 // allocate buffers:
1026 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
1027 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
1028 free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
1029
1030 // Prepare the responses of the anticollision phase
1031 // there will be not enough time to do this at the moment the reader sends it REQA
1032 for (size_t i=0; i<TAG_RESPONSE_COUNT; i++)
1033 prepare_allocated_tag_modulation(&responses[i]);
1034
1035 int len = 0;
1036
1037 // To control where we are in the protocol
1038 int order = 0;
1039 int lastorder;
1040
1041 // Just to allow some checks
1042 int happened = 0;
1043 int happened2 = 0;
1044 int cmdsRecvd = 0;
1045 tag_response_info_t* p_response;
1046
1047 LED_A_ON();
1048 for(;;) {
1049 WDT_HIT();
1050
1051 // Clean receive command buffer
1052 if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
1053 DbpString("Button press");
1054 break;
1055 }
1056
1057 // incease nonce at every command recieved
1058 nonce++;
1059 num_to_bytes(nonce, 4, response5);
1060
1061 p_response = NULL;
1062
1063 // Okay, look at the command now.
1064 lastorder = order;
1065 if(receivedCmd[0] == ISO14443A_CMD_REQA) { // Received a REQUEST
1066 p_response = &responses[0]; order = 1;
1067 } else if(receivedCmd[0] == ISO14443A_CMD_WUPA) { // Received a WAKEUP
1068 p_response = &responses[0]; order = 6;
1069 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT) { // Received request for UID (cascade 1)
1070 p_response = &responses[1]; order = 2;
1071 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2) { // Received request for UID (cascade 2)
1072 p_response = &responses[2]; order = 20;
1073 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT) { // Received a SELECT (cascade 1)
1074 p_response = &responses[3]; order = 3;
1075 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2) { // Received a SELECT (cascade 2)
1076 p_response = &responses[4]; order = 30;
1077 } else if(receivedCmd[0] == ISO14443A_CMD_READBLOCK) { // Received a (plain) READ
1078 uint8_t block = receivedCmd[1];
1079 // if Ultralight or NTAG (4 byte blocks)
1080 if ( tagType == 7 || tagType == 2 ) {
1081 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1082 uint16_t start = 4 * (block+12);
1083 uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
1084 emlGetMemBt( emdata, start, 16);
1085 AppendCrc14443a(emdata, 16);
1086 EmSendCmdEx(emdata, sizeof(emdata), false);
1087 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1088 p_response = NULL;
1089 } else { // all other tags (16 byte block tags)
1090 EmSendCmdEx(data+(4*receivedCmd[1]),16,false);
1091 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1092 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1093 p_response = NULL;
1094 }
1095 } else if(receivedCmd[0] == MIFARE_ULEV1_FASTREAD) { // Received a FAST READ (ranged read)
1096 uint8_t emdata[MAX_FRAME_SIZE];
1097 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1098 int start = (receivedCmd[1]+12) * 4;
1099 int len = (receivedCmd[2] - receivedCmd[1] + 1) * 4;
1100 emlGetMemBt( emdata, start, len);
1101 AppendCrc14443a(emdata, len);
1102 EmSendCmdEx(emdata, len+2, false);
1103 p_response = NULL;
1104 } else if(receivedCmd[0] == MIFARE_ULEV1_READSIG && tagType == 7) { // Received a READ SIGNATURE --
1105 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1106 uint16_t start = 4 * 4;
1107 uint8_t emdata[34];
1108 emlGetMemBt( emdata, start, 32);
1109 AppendCrc14443a(emdata, 32);
1110 EmSendCmdEx(emdata, sizeof(emdata), false);
1111 p_response = NULL;
1112 } else if (receivedCmd[0] == MIFARE_ULEV1_READ_CNT && tagType == 7) { // Received a READ COUNTER --
1113 uint8_t index = receivedCmd[1];
1114 uint8_t data[] = {0x00,0x00,0x00,0x14,0xa5};
1115 if ( counters[index] > 0) {
1116 num_to_bytes(counters[index], 3, data);
1117 AppendCrc14443a(data, sizeof(data)-2);
1118 }
1119 EmSendCmdEx(data,sizeof(data),false);
1120 p_response = NULL;
1121 } else if (receivedCmd[0] == MIFARE_ULEV1_INCR_CNT && tagType == 7) { // Received a INC COUNTER --
1122 // number of counter
1123 uint8_t counter = receivedCmd[1];
1124 uint32_t val = bytes_to_num(receivedCmd+2,4);
1125 counters[counter] = val;
1126
1127 // send ACK
1128 uint8_t ack[] = {0x0a};
1129 EmSendCmdEx(ack,sizeof(ack),false);
1130 p_response = NULL;
1131 } else if(receivedCmd[0] == MIFARE_ULEV1_CHECKTEAR && tagType == 7) { // Received a CHECK_TEARING_EVENT --
1132 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1133 uint8_t emdata[3];
1134 uint8_t counter=0;
1135 if (receivedCmd[1]<3) counter = receivedCmd[1];
1136 emlGetMemBt( emdata, 10+counter, 1);
1137 AppendCrc14443a(emdata, sizeof(emdata)-2);
1138 EmSendCmdEx(emdata, sizeof(emdata), false);
1139 p_response = NULL;
1140 } else if(receivedCmd[0] == ISO14443A_CMD_HALT) { // Received a HALT
1141 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1142 p_response = NULL;
1143 } else if(receivedCmd[0] == MIFARE_AUTH_KEYA || receivedCmd[0] == MIFARE_AUTH_KEYB) { // Received an authentication request
1144 if ( tagType == 7 ) { // IF NTAG /EV1 0x60 == GET_VERSION, not a authentication request.
1145 uint8_t emdata[10];
1146 emlGetMemBt( emdata, 0, 8 );
1147 AppendCrc14443a(emdata, sizeof(emdata)-2);
1148 EmSendCmdEx(emdata, sizeof(emdata), false);
1149 p_response = NULL;
1150 } else {
1151 p_response = &responses[5]; order = 7;
1152 }
1153 } else if(receivedCmd[0] == ISO14443A_CMD_RATS) { // Received a RATS request
1154 if (tagType == 1 || tagType == 2) { // RATS not supported
1155 EmSend4bit(CARD_NACK_NA);
1156 p_response = NULL;
1157 } else {
1158 p_response = &responses[6]; order = 70;
1159 }
1160 } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
1161 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1162 uint32_t nr = bytes_to_num(receivedCmd,4);
1163 uint32_t ar = bytes_to_num(receivedCmd+4,4);
1164
1165 if ( (flags & FLAG_NR_AR_ATTACK) == FLAG_NR_AR_ATTACK ) {
1166 if(ar_nr_collected < 2){
1167 ar_nr_responses[ar_nr_collected*4] = cuid;
1168 ar_nr_responses[ar_nr_collected*4+1] = nonce;
1169 ar_nr_responses[ar_nr_collected*4+2] = nr;
1170 ar_nr_responses[ar_nr_collected*4+3] = ar;
1171 ar_nr_collected++;
1172 }
1173 if(ar_nr_collected > 1 ) {
1174 if (MF_DBGLEVEL >= 2 && !(flags & FLAG_INTERACTIVE)) {
1175 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
1176 Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
1177 ar_nr_responses[0], // CUID
1178 ar_nr_responses[1], // NT
1179 ar_nr_responses[2], // AR1
1180 ar_nr_responses[3], // NR1
1181 ar_nr_responses[6], // AR2
1182 ar_nr_responses[7] // NR2
1183 );
1184 }
1185 uint8_t len = ar_nr_collected*4*4;
1186 cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, len, 0, &ar_nr_responses, len);
1187 ar_nr_collected = 0;
1188 memset(ar_nr_responses, 0x00, len);
1189 }
1190 }
1191
1192 } else if (receivedCmd[0] == MIFARE_ULC_AUTH_1 ) { // ULC authentication, or Desfire Authentication
1193 } else if (receivedCmd[0] == MIFARE_ULEV1_AUTH) { // NTAG / EV-1 authentication
1194 if ( tagType == 7 ) {
1195 uint16_t start = 13; //first 4 blocks of emu are [getversion answer - check tearing - pack - 0x00]
1196 uint8_t emdata[4];
1197 emlGetMemBt( emdata, start, 2);
1198 AppendCrc14443a(emdata, 2);
1199 EmSendCmdEx(emdata, sizeof(emdata), false);
1200 p_response = NULL;
1201 uint32_t pwd = bytes_to_num(receivedCmd+1,4);
1202
1203 if ( MF_DBGLEVEL >= 3) Dbprintf("Auth attempt: %08x", pwd);
1204 }
1205 } else {
1206 // Check for ISO 14443A-4 compliant commands, look at left nibble
1207 switch (receivedCmd[0]) {
1208 case 0x02:
1209 case 0x03: { // IBlock (command no CID)
1210 dynamic_response_info.response[0] = receivedCmd[0];
1211 dynamic_response_info.response[1] = 0x90;
1212 dynamic_response_info.response[2] = 0x00;
1213 dynamic_response_info.response_n = 3;
1214 } break;
1215 case 0x0B:
1216 case 0x0A: { // IBlock (command CID)
1217 dynamic_response_info.response[0] = receivedCmd[0];
1218 dynamic_response_info.response[1] = 0x00;
1219 dynamic_response_info.response[2] = 0x90;
1220 dynamic_response_info.response[3] = 0x00;
1221 dynamic_response_info.response_n = 4;
1222 } break;
1223
1224 case 0x1A:
1225 case 0x1B: { // Chaining command
1226 dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1227 dynamic_response_info.response_n = 2;
1228 } break;
1229
1230 case 0xaa:
1231 case 0xbb: {
1232 dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1233 dynamic_response_info.response_n = 2;
1234 } break;
1235
1236 case 0xBA: { // ping / pong
1237 dynamic_response_info.response[0] = 0xAB;
1238 dynamic_response_info.response[1] = 0x00;
1239 dynamic_response_info.response_n = 2;
1240 } break;
1241
1242 case 0xCA:
1243 case 0xC2: { // Readers sends deselect command
1244 dynamic_response_info.response[0] = 0xCA;
1245 dynamic_response_info.response[1] = 0x00;
1246 dynamic_response_info.response_n = 2;
1247 } break;
1248
1249 default: {
1250 // Never seen this command before
1251 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1252 Dbprintf("Received unknown command (len=%d):",len);
1253 Dbhexdump(len,receivedCmd,false);
1254 // Do not respond
1255 dynamic_response_info.response_n = 0;
1256 } break;
1257 }
1258
1259 if (dynamic_response_info.response_n > 0) {
1260 // Copy the CID from the reader query
1261 dynamic_response_info.response[1] = receivedCmd[1];
1262
1263 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1264 AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
1265 dynamic_response_info.response_n += 2;
1266
1267 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1268 Dbprintf("Error preparing tag response");
1269 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1270 break;
1271 }
1272 p_response = &dynamic_response_info;
1273 }
1274 }
1275
1276 // Count number of wakeups received after a halt
1277 if(order == 6 && lastorder == 5) { happened++; }
1278
1279 // Count number of other messages after a halt
1280 if(order != 6 && lastorder == 5) { happened2++; }
1281
1282 // comment this limit if you want to simulation longer
1283 if (!tracing) {
1284 Dbprintf("Trace Full. Simulation stopped.");
1285 break;
1286 }
1287 // comment this limit if you want to simulation longer
1288 if(cmdsRecvd > 999) {
1289 DbpString("1000 commands later...");
1290 break;
1291 }
1292 cmdsRecvd++;
1293
1294 if (p_response != NULL) {
1295 EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1296 // do the tracing for the previous reader request and this tag answer:
1297 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1298 GetParity(p_response->response, p_response->response_n, par);
1299
1300 EmLogTrace(Uart.output,
1301 Uart.len,
1302 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1303 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1304 Uart.parity,
1305 p_response->response,
1306 p_response->response_n,
1307 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1308 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1309 par);
1310 }
1311 }
1312
1313 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1314 set_tracing(FALSE);
1315 BigBuf_free_keep_EM();
1316 LED_A_OFF();
1317
1318 if (MF_DBGLEVEL >= 4){
1319 Dbprintf("-[ Wake ups after halt [%d]", happened);
1320 Dbprintf("-[ Messages after halt [%d]", happened2);
1321 Dbprintf("-[ Num of received cmd [%d]", cmdsRecvd);
1322 }
1323 }
1324
1325 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1326 // of bits specified in the delay parameter.
1327 void PrepareDelayedTransfer(uint16_t delay) {
1328 delay &= 0x07;
1329 if (!delay) return;
1330
1331 uint8_t bitmask = 0;
1332 uint8_t bits_to_shift = 0;
1333 uint8_t bits_shifted = 0;
1334 uint16_t i = 0;
1335
1336 for (i = 0; i < delay; ++i)
1337 bitmask |= (0x01 << i);
1338
1339 ToSend[++ToSendMax] = 0x00;
1340
1341 for (i = 0; i < ToSendMax; ++i) {
1342 bits_to_shift = ToSend[i] & bitmask;
1343 ToSend[i] = ToSend[i] >> delay;
1344 ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1345 bits_shifted = bits_to_shift;
1346 }
1347 }
1348
1349
1350 //-------------------------------------------------------------------------------------
1351 // Transmit the command (to the tag) that was placed in ToSend[].
1352 // Parameter timing:
1353 // if NULL: transfer at next possible time, taking into account
1354 // request guard time and frame delay time
1355 // if == 0: transfer immediately and return time of transfer
1356 // if != 0: delay transfer until time specified
1357 //-------------------------------------------------------------------------------------
1358 static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing) {
1359 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1360
1361 uint32_t ThisTransferTime = 0;
1362
1363 if (timing) {
1364 if(*timing == 0) { // Measure time
1365 *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1366 } else {
1367 PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
1368 }
1369 if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
1370 while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
1371 LastTimeProxToAirStart = *timing;
1372 } else {
1373 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1374
1375 while(GetCountSspClk() < ThisTransferTime);
1376
1377 LastTimeProxToAirStart = ThisTransferTime;
1378 }
1379
1380 // clear TXRDY
1381 AT91C_BASE_SSC->SSC_THR = SEC_Y;
1382
1383 uint16_t c = 0;
1384 for(;;) {
1385 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1386 AT91C_BASE_SSC->SSC_THR = cmd[c];
1387 ++c;
1388 if(c >= len)
1389 break;
1390 }
1391 }
1392
1393 NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1394 }
1395
1396 //-----------------------------------------------------------------------------
1397 // Prepare reader command (in bits, support short frames) to send to FPGA
1398 //-----------------------------------------------------------------------------
1399 void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity)
1400 {
1401 int i, j;
1402 int last = 0;
1403 uint8_t b;
1404
1405 ToSendReset();
1406
1407 // Start of Communication (Seq. Z)
1408 ToSend[++ToSendMax] = SEC_Z;
1409 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1410
1411 size_t bytecount = nbytes(bits);
1412 // Generate send structure for the data bits
1413 for (i = 0; i < bytecount; i++) {
1414 // Get the current byte to send
1415 b = cmd[i];
1416 size_t bitsleft = MIN((bits-(i*8)),8);
1417
1418 for (j = 0; j < bitsleft; j++) {
1419 if (b & 1) {
1420 // Sequence X
1421 ToSend[++ToSendMax] = SEC_X;
1422 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1423 last = 1;
1424 } else {
1425 if (last == 0) {
1426 // Sequence Z
1427 ToSend[++ToSendMax] = SEC_Z;
1428 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1429 } else {
1430 // Sequence Y
1431 ToSend[++ToSendMax] = SEC_Y;
1432 last = 0;
1433 }
1434 }
1435 b >>= 1;
1436 }
1437
1438 // Only transmit parity bit if we transmitted a complete byte
1439 if (j == 8 && parity != NULL) {
1440 // Get the parity bit
1441 if (parity[i>>3] & (0x80 >> (i&0x0007))) {
1442 // Sequence X
1443 ToSend[++ToSendMax] = SEC_X;
1444 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1445 last = 1;
1446 } else {
1447 if (last == 0) {
1448 // Sequence Z
1449 ToSend[++ToSendMax] = SEC_Z;
1450 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1451 } else {
1452 // Sequence Y
1453 ToSend[++ToSendMax] = SEC_Y;
1454 last = 0;
1455 }
1456 }
1457 }
1458 }
1459
1460 // End of Communication: Logic 0 followed by Sequence Y
1461 if (last == 0) {
1462 // Sequence Z
1463 ToSend[++ToSendMax] = SEC_Z;
1464 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1465 } else {
1466 // Sequence Y
1467 ToSend[++ToSendMax] = SEC_Y;
1468 last = 0;
1469 }
1470 ToSend[++ToSendMax] = SEC_Y;
1471
1472 // Convert to length of command:
1473 ++ToSendMax;
1474 }
1475
1476 //-----------------------------------------------------------------------------
1477 // Prepare reader command to send to FPGA
1478 //-----------------------------------------------------------------------------
1479 void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity) {
1480 CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
1481 }
1482
1483 //-----------------------------------------------------------------------------
1484 // Wait for commands from reader
1485 // Stop when button is pressed (return 1) or field was gone (return 2)
1486 // Or return 0 when command is captured
1487 //-----------------------------------------------------------------------------
1488 static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity) {
1489 *len = 0;
1490
1491 uint32_t timer = 0, vtime = 0;
1492 int analogCnt = 0;
1493 int analogAVG = 0;
1494
1495 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1496 // only, since we are receiving, not transmitting).
1497 // Signal field is off with the appropriate LED
1498 LED_D_OFF();
1499 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1500
1501 // Set ADC to read field strength
1502 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1503 AT91C_BASE_ADC->ADC_MR =
1504 ADC_MODE_PRESCALE(63) |
1505 ADC_MODE_STARTUP_TIME(1) |
1506 ADC_MODE_SAMPLE_HOLD_TIME(15);
1507 AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1508 // start ADC
1509 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1510
1511 // Now run a 'software UART' on the stream of incoming samples.
1512 UartInit(received, parity);
1513
1514 // Clear RXRDY:
1515 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1516
1517 for(;;) {
1518 WDT_HIT();
1519
1520 if (BUTTON_PRESS()) return 1;
1521
1522 // test if the field exists
1523 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1524 analogCnt++;
1525 analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1526 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1527 if (analogCnt >= 32) {
1528 if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1529 vtime = GetTickCount();
1530 if (!timer) timer = vtime;
1531 // 50ms no field --> card to idle state
1532 if (vtime - timer > 50) return 2;
1533 } else
1534 if (timer) timer = 0;
1535 analogCnt = 0;
1536 analogAVG = 0;
1537 }
1538 }
1539
1540 // receive and test the miller decoding
1541 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1542 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1543 if(MillerDecoding(b, 0)) {
1544 *len = Uart.len;
1545 return 0;
1546 }
1547 }
1548 }
1549 }
1550
1551 int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded) {
1552 uint8_t b;
1553 uint16_t i = 0;
1554 uint32_t ThisTransferTime;
1555
1556 // Modulate Manchester
1557 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1558
1559 // include correction bit if necessary
1560 if (Uart.parityBits & 0x01) {
1561 correctionNeeded = TRUE;
1562 }
1563 // 1236, so correction bit needed
1564 i = (correctionNeeded) ? 0 : 1;
1565
1566 // clear receiving shift register and holding register
1567 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1568 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1569 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1570 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1571
1572 // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1573 for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never
1574 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1575 if (AT91C_BASE_SSC->SSC_RHR) break;
1576 }
1577
1578 while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1579
1580 // Clear TXRDY:
1581 AT91C_BASE_SSC->SSC_THR = SEC_F;
1582
1583 // send cycle
1584 for(; i < respLen; ) {
1585 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1586 AT91C_BASE_SSC->SSC_THR = resp[i++];
1587 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1588 }
1589
1590 if(BUTTON_PRESS()) break;
1591 }
1592
1593 // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1594 uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3; // twich /8 ?? >>3,
1595 for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
1596 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1597 AT91C_BASE_SSC->SSC_THR = SEC_F;
1598 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1599 i++;
1600 }
1601 }
1602 LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
1603 return 0;
1604 }
1605
1606 int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
1607 Code4bitAnswerAsTag(resp);
1608 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1609 // do the tracing for the previous reader request and this tag answer:
1610 uint8_t par[1] = {0x00};
1611 GetParity(&resp, 1, par);
1612 EmLogTrace(Uart.output,
1613 Uart.len,
1614 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1615 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1616 Uart.parity,
1617 &resp,
1618 1,
1619 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1620 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1621 par);
1622 return res;
1623 }
1624
1625 int EmSend4bit(uint8_t resp){
1626 return EmSend4bitEx(resp, false);
1627 }
1628
1629 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){
1630 CodeIso14443aAsTagPar(resp, respLen, par);
1631 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1632 // do the tracing for the previous reader request and this tag answer:
1633 EmLogTrace(Uart.output,
1634 Uart.len,
1635 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1636 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1637 Uart.parity,
1638 resp,
1639 respLen,
1640 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1641 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1642 par);
1643 return res;
1644 }
1645
1646 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){
1647 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1648 GetParity(resp, respLen, par);
1649 return EmSendCmdExPar(resp, respLen, correctionNeeded, par);
1650 }
1651
1652 int EmSendCmd(uint8_t *resp, uint16_t respLen){
1653 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1654 GetParity(resp, respLen, par);
1655 return EmSendCmdExPar(resp, respLen, false, par);
1656 }
1657
1658 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
1659 return EmSendCmdExPar(resp, respLen, false, par);
1660 }
1661
1662 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
1663 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity)
1664 {
1665 // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1666 // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1667 // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1668 uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1669 uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1670 uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1671 reader_EndTime = tag_StartTime - exact_fdt;
1672 reader_StartTime = reader_EndTime - reader_modlen;
1673
1674 if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE))
1675 return FALSE;
1676 else
1677 return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
1678
1679 }
1680
1681 //-----------------------------------------------------------------------------
1682 // Wait a certain time for tag response
1683 // If a response is captured return TRUE
1684 // If it takes too long return FALSE
1685 //-----------------------------------------------------------------------------
1686 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset) {
1687 uint32_t c = 0x00;
1688
1689 // Set FPGA mode to "reader listen mode", no modulation (listen
1690 // only, since we are receiving, not transmitting).
1691 // Signal field is on with the appropriate LED
1692 LED_D_ON();
1693 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1694
1695 // Now get the answer from the card
1696 DemodInit(receivedResponse, receivedResponsePar);
1697
1698 // clear RXRDY:
1699 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1700
1701 for(;;) {
1702 WDT_HIT();
1703
1704 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1705 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1706 if(ManchesterDecoding(b, offset, 0)) {
1707 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1708 return TRUE;
1709 } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
1710 return FALSE;
1711 }
1712 }
1713 }
1714 }
1715
1716 void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing) {
1717
1718 CodeIso14443aBitsAsReaderPar(frame, bits, par);
1719 // Send command to tag
1720 TransmitFor14443a(ToSend, ToSendMax, timing);
1721 if(trigger) LED_A_ON();
1722
1723 LogTrace(frame, nbytes(bits), (LastTimeProxToAirStart<<4) + DELAY_ARM2AIR_AS_READER, ((LastTimeProxToAirStart + LastProxToAirDuration)<<4) + DELAY_ARM2AIR_AS_READER, par, TRUE);
1724 }
1725
1726 void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing) {
1727 ReaderTransmitBitsPar(frame, len*8, par, timing);
1728 }
1729
1730 void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing) {
1731 // Generate parity and redirect
1732 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1733 GetParity(frame, len/8, par);
1734 ReaderTransmitBitsPar(frame, len, par, timing);
1735 }
1736
1737 void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing) {
1738 // Generate parity and redirect
1739 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1740 GetParity(frame, len, par);
1741 ReaderTransmitBitsPar(frame, len*8, par, timing);
1742 }
1743
1744 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity) {
1745 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset))
1746 return FALSE;
1747 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1748 return Demod.len;
1749 }
1750
1751 int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity) {
1752 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0))
1753 return FALSE;
1754 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1755 return Demod.len;
1756 }
1757
1758 // performs iso14443a anticollision (optional) and card select procedure
1759 // fills the uid and cuid pointer unless NULL
1760 // fills the card info record unless NULL
1761 // if anticollision is false, then the UID must be provided in uid_ptr[]
1762 // and num_cascades must be set (1: 4 Byte UID, 2: 7 Byte UID, 3: 10 Byte UID)
1763 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) {
1764 uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP
1765 uint8_t sel_all[] = { 0x93,0x20 };
1766 uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1767 uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1768 uint8_t resp[MAX_FRAME_SIZE] = {0}; // theoretically. A usual RATS will be much smaller
1769 uint8_t resp_par[MAX_PARITY_SIZE] = {0};
1770 byte_t uid_resp[4] = {0};
1771 size_t uid_resp_len = 0;
1772
1773 uint8_t sak = 0x04; // cascade uid
1774 int cascade_level = 0;
1775 int len;
1776
1777 // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1778 ReaderTransmitBitsPar(wupa, 7, NULL, NULL);
1779
1780 // Receive the ATQA
1781 if(!ReaderReceive(resp, resp_par)) return 0;
1782
1783 if(p_hi14a_card) {
1784 memcpy(p_hi14a_card->atqa, resp, 2);
1785 p_hi14a_card->uidlen = 0;
1786 memset(p_hi14a_card->uid,0,10);
1787 }
1788
1789 if (anticollision) {
1790 // clear uid
1791 if (uid_ptr)
1792 memset(uid_ptr,0,10);
1793 }
1794
1795 // check for proprietary anticollision:
1796 if ((resp[0] & 0x1F) == 0) return 3;
1797
1798 // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1799 // which case we need to make a cascade 2 request and select - this is a long UID
1800 // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1801 for(; sak & 0x04; cascade_level++) {
1802 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1803 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1804
1805 if (anticollision) {
1806 // SELECT_ALL
1807 ReaderTransmit(sel_all, sizeof(sel_all), NULL);
1808 if (!ReaderReceive(resp, resp_par)) return 0;
1809
1810 if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit
1811 memset(uid_resp, 0, 4);
1812 uint16_t uid_resp_bits = 0;
1813 uint16_t collision_answer_offset = 0;
1814 // anti-collision-loop:
1815 while (Demod.collisionPos) {
1816 Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1817 for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point
1818 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1819 uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8);
1820 }
1821 uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position
1822 uid_resp_bits++;
1823 // construct anticollosion command:
1824 sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits
1825 for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1826 sel_uid[2+i] = uid_resp[i];
1827 }
1828 collision_answer_offset = uid_resp_bits%8;
1829 ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1830 if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0;
1831 }
1832 // finally, add the last bits and BCC of the UID
1833 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1834 uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1835 uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1836 }
1837
1838 } else { // no collision, use the response to SELECT_ALL as current uid
1839 memcpy(uid_resp, resp, 4);
1840 }
1841
1842 } else {
1843 if (cascade_level < num_cascades - 1) {
1844 uid_resp[0] = 0x88;
1845 memcpy(uid_resp+1, uid_ptr+cascade_level*3, 3);
1846 } else {
1847 memcpy(uid_resp, uid_ptr+cascade_level*3, 4);
1848 }
1849 }
1850 uid_resp_len = 4;
1851
1852 // calculate crypto UID. Always use last 4 Bytes.
1853 if(cuid_ptr)
1854 *cuid_ptr = bytes_to_num(uid_resp, 4);
1855
1856 // Construct SELECT UID command
1857 sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1858 memcpy(sel_uid+2, uid_resp, 4); // the UID received during anticollision, or the provided UID
1859 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC
1860 AppendCrc14443a(sel_uid, 7); // calculate and add CRC
1861 ReaderTransmit(sel_uid, sizeof(sel_uid), NULL);
1862
1863 // Receive the SAK
1864 if (!ReaderReceive(resp, resp_par)) return 0;
1865
1866 sak = resp[0];
1867
1868 // Test if more parts of the uid are coming
1869 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
1870 // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
1871 // http://www.nxp.com/documents/application_note/AN10927.pdf
1872 uid_resp[0] = uid_resp[1];
1873 uid_resp[1] = uid_resp[2];
1874 uid_resp[2] = uid_resp[3];
1875 uid_resp_len = 3;
1876 }
1877
1878 if(uid_ptr && anticollision)
1879 memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
1880
1881 if(p_hi14a_card) {
1882 memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
1883 p_hi14a_card->uidlen += uid_resp_len;
1884 }
1885 }
1886
1887 if(p_hi14a_card) {
1888 p_hi14a_card->sak = sak;
1889 p_hi14a_card->ats_len = 0;
1890 }
1891
1892 // non iso14443a compliant tag
1893 if( (sak & 0x20) == 0) return 2;
1894
1895 // Request for answer to select
1896 AppendCrc14443a(rats, 2);
1897 ReaderTransmit(rats, sizeof(rats), NULL);
1898
1899 if (!(len = ReaderReceive(resp, resp_par))) return 0;
1900
1901 if(p_hi14a_card) {
1902 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
1903 p_hi14a_card->ats_len = len;
1904 }
1905
1906 // reset the PCB block number
1907 iso14_pcb_blocknum = 0;
1908
1909 // set default timeout based on ATS
1910 iso14a_set_ATS_timeout(resp);
1911
1912 return 1;
1913 }
1914
1915 void iso14443a_setup(uint8_t fpga_minor_mode) {
1916 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1917 // Set up the synchronous serial port
1918 FpgaSetupSsc();
1919 // connect Demodulated Signal to ADC:
1920 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1921
1922 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
1923
1924 LED_D_OFF();
1925 // Signal field is on with the appropriate LED
1926 if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD ||
1927 fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN)
1928 LED_D_ON();
1929
1930 // Prepare the demodulation functions
1931 DemodReset();
1932 UartReset();
1933
1934 iso14a_set_timeout(10*106); // 10ms default
1935
1936 //NextTransferTime = 2 * DELAY_ARM2AIR_AS_READER;
1937 NextTransferTime = DELAY_ARM2AIR_AS_READER << 1;
1938
1939 // Start the timer
1940 StartCountSspClk();
1941 }
1942
1943 int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
1944 uint8_t parity[MAX_PARITY_SIZE] = {0x00};
1945 uint8_t real_cmd[cmd_len+4];
1946 real_cmd[0] = 0x0a; //I-Block
1947 // put block number into the PCB
1948 real_cmd[0] |= iso14_pcb_blocknum;
1949 real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
1950 memcpy(real_cmd+2, cmd, cmd_len);
1951 AppendCrc14443a(real_cmd,cmd_len+2);
1952
1953 ReaderTransmit(real_cmd, cmd_len+4, NULL);
1954 size_t len = ReaderReceive(data, parity);
1955 //DATA LINK ERROR
1956 if (!len) return 0;
1957
1958 uint8_t *data_bytes = (uint8_t *) data;
1959
1960 // if we received an I- or R(ACK)-Block with a block number equal to the
1961 // current block number, toggle the current block number
1962 if (len >= 4 // PCB+CID+CRC = 4 bytes
1963 && ((data_bytes[0] & 0xC0) == 0 // I-Block
1964 || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
1965 && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
1966 {
1967 iso14_pcb_blocknum ^= 1;
1968 }
1969
1970 return len;
1971 }
1972
1973 //-----------------------------------------------------------------------------
1974 // Read an ISO 14443a tag. Send out commands and store answers.
1975 //
1976 //-----------------------------------------------------------------------------
1977 void ReaderIso14443a(UsbCommand *c) {
1978 iso14a_command_t param = c->arg[0];
1979 size_t len = c->arg[1] & 0xffff;
1980 size_t lenbits = c->arg[1] >> 16;
1981 uint32_t timeout = c->arg[2];
1982 uint8_t *cmd = c->d.asBytes;
1983 uint32_t arg0 = 0;
1984 byte_t buf[USB_CMD_DATA_SIZE] = {0x00};
1985 uint8_t par[MAX_PARITY_SIZE] = {0x00};
1986
1987 if (param & ISO14A_CONNECT)
1988 clear_trace();
1989
1990 set_tracing(TRUE);
1991
1992 if (param & ISO14A_REQUEST_TRIGGER)
1993 iso14a_set_trigger(TRUE);
1994
1995 if (param & ISO14A_CONNECT) {
1996 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
1997 if(!(param & ISO14A_NO_SELECT)) {
1998 iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
1999 arg0 = iso14443a_select_card(NULL,card,NULL, true, 0);
2000 cmd_send(CMD_ACK, arg0, card->uidlen, 0, buf, sizeof(iso14a_card_select_t));
2001 // if it fails, the cmdhf14a.c client quites.. however this one still executes.
2002 if ( arg0 == 0 ) return;
2003 }
2004 }
2005
2006 if (param & ISO14A_SET_TIMEOUT)
2007 iso14a_set_timeout(timeout);
2008
2009 if (param & ISO14A_APDU) {
2010 arg0 = iso14_apdu(cmd, len, buf);
2011 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2012 }
2013
2014 if (param & ISO14A_RAW) {
2015 if(param & ISO14A_APPEND_CRC) {
2016 if(param & ISO14A_TOPAZMODE) {
2017 AppendCrc14443b(cmd,len);
2018 } else {
2019 AppendCrc14443a(cmd,len);
2020 }
2021 len += 2;
2022 if (lenbits) lenbits += 16;
2023 }
2024 if(lenbits>0) { // want to send a specific number of bits (e.g. short commands)
2025 if(param & ISO14A_TOPAZMODE) {
2026 int bits_to_send = lenbits;
2027 uint16_t i = 0;
2028 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL); // first byte is always short (7bits) and no parity
2029 bits_to_send -= 7;
2030 while (bits_to_send > 0) {
2031 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL); // following bytes are 8 bit and no parity
2032 bits_to_send -= 8;
2033 }
2034 } else {
2035 GetParity(cmd, lenbits/8, par);
2036 ReaderTransmitBitsPar(cmd, lenbits, par, NULL); // bytes are 8 bit with odd parity
2037 }
2038 } else { // want to send complete bytes only
2039 if(param & ISO14A_TOPAZMODE) {
2040 uint16_t i = 0;
2041 ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL); // first byte: 7 bits, no paritiy
2042 while (i < len) {
2043 ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL); // following bytes: 8 bits, no paritiy
2044 }
2045 } else {
2046 ReaderTransmit(cmd,len, NULL); // 8 bits, odd parity
2047 }
2048 }
2049 arg0 = ReaderReceive(buf, par);
2050 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2051 }
2052
2053 if (param & ISO14A_REQUEST_TRIGGER)
2054 iso14a_set_trigger(FALSE);
2055
2056 if (param & ISO14A_NO_DISCONNECT)
2057 return;
2058
2059 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2060 set_tracing(FALSE);
2061 LEDsoff();
2062 }
2063
2064 // Determine the distance between two nonces.
2065 // Assume that the difference is small, but we don't know which is first.
2066 // Therefore try in alternating directions.
2067 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
2068
2069 if (nt1 == nt2) return 0;
2070
2071 uint16_t i;
2072 uint32_t nttmp1 = nt1;
2073 uint32_t nttmp2 = nt2;
2074
2075 for (i = 1; i < (32768/8); ++i) {
2076 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i;
2077 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -i;
2078
2079 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+1;
2080 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+1);
2081 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+2;
2082 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+2);
2083 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+3;
2084 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+3);
2085 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+4;
2086 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+4);
2087 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+5;
2088 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+5);
2089 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+6;
2090 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+6);
2091 nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i+7;
2092 nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -(i+7);
2093 }
2094 // either nt1 or nt2 are invalid nonces
2095 return(-99999);
2096 }
2097
2098 //-----------------------------------------------------------------------------
2099 // Recover several bits of the cypher stream. This implements (first stages of)
2100 // the algorithm described in "The Dark Side of Security by Obscurity and
2101 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
2102 // (article by Nicolas T. Courtois, 2009)
2103 //-----------------------------------------------------------------------------
2104 void ReaderMifare(bool first_try, uint8_t block ) {
2105 uint8_t mf_auth[] = { MIFARE_AUTH_KEYA, block, 0x00, 0x00 };
2106 uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
2107 uint8_t uid[10] = {0,0,0,0,0,0,0,0,0,0};
2108 uint8_t par_list[8] = {0,0,0,0,0,0,0,0};
2109 uint8_t ks_list[8] = {0,0,0,0,0,0,0,0};
2110 uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE] = {0x00};
2111 uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
2112 uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
2113 byte_t nt_diff = 0;
2114 uint32_t nt = 0;
2115 uint32_t previous_nt = 0;
2116 uint32_t cuid = 0;
2117
2118 int32_t catch_up_cycles = 0;
2119 int32_t last_catch_up = 0;
2120 int32_t isOK = 0;
2121 int32_t nt_distance = 0;
2122
2123 uint16_t elapsed_prng_sequences = 1;
2124 uint16_t consecutive_resyncs = 0;
2125 uint16_t unexpected_random = 0;
2126 uint16_t sync_tries = 0;
2127
2128 // static variables here, is re-used in the next call
2129 static uint32_t nt_attacked = 0;
2130 static uint32_t sync_time = 0;
2131 static uint32_t sync_cycles = 0;
2132 static uint8_t par_low = 0;
2133 static uint8_t mf_nr_ar3 = 0;
2134
2135 #define PRNG_SEQUENCE_LENGTH (1 << 16)
2136 #define MAX_UNEXPECTED_RANDOM 4 // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up.
2137 #define MAX_SYNC_TRIES 32
2138
2139 BigBuf_free(); BigBuf_Clear_ext(false);
2140 clear_trace();
2141 set_tracing(TRUE);
2142 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2143
2144 AppendCrc14443a(mf_auth, 2);
2145
2146 if (first_try) {
2147 sync_time = GetCountSspClk() & 0xfffffff8;
2148 sync_cycles = PRNG_SEQUENCE_LENGTH + 1130; //65536; //0x10000 // Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
2149 mf_nr_ar3 = 0;
2150 nt_attacked = 0;
2151 par_low = 0;
2152 } else {
2153 // we were unsuccessful on a previous call.
2154 // Try another READER nonce (first 3 parity bits remain the same)
2155 ++mf_nr_ar3;
2156 mf_nr_ar[3] = mf_nr_ar3;
2157 par[0] = par_low;
2158 }
2159
2160 bool have_uid = FALSE;
2161 uint8_t cascade_levels = 0;
2162
2163 LED_C_ON();
2164 uint16_t i;
2165 for(i = 0; TRUE; ++i) {
2166
2167 WDT_HIT();
2168
2169 // Test if the action was cancelled
2170 if(BUTTON_PRESS()) {
2171 isOK = -1;
2172 break;
2173 }
2174
2175 // this part is from Piwi's faster nonce collecting part in Hardnested.
2176 if (!have_uid) { // need a full select cycle to get the uid first
2177 iso14a_card_select_t card_info;
2178 if(!iso14443a_select_card(uid, &card_info, &cuid, true, 0)) {
2179 if (MF_DBGLEVEL >= 4) Dbprintf("Mifare: Can't select card (ALL)");
2180 break;
2181 }
2182 switch (card_info.uidlen) {
2183 case 4 : cascade_levels = 1; break;
2184 case 7 : cascade_levels = 2; break;
2185 case 10: cascade_levels = 3; break;
2186 default: break;
2187 }
2188 have_uid = TRUE;
2189 } else { // no need for anticollision. We can directly select the card
2190 if(!iso14443a_select_card(uid, NULL, &cuid, false, cascade_levels)) {
2191 if (MF_DBGLEVEL >= 4) Dbprintf("Mifare: Can't select card (UID)");
2192 continue;
2193 }
2194 }
2195
2196 // Sending timeslot of ISO14443a frame
2197 sync_time = (sync_time & 0xfffffff8 ) + sync_cycles + catch_up_cycles;
2198 catch_up_cycles = 0;
2199
2200 // if we missed the sync time already, advance to the next nonce repeat
2201 while( GetCountSspClk() > sync_time) {
2202 ++elapsed_prng_sequences;
2203 sync_time = (sync_time & 0xfffffff8 ) + sync_cycles;
2204 }
2205
2206 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2207 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2208
2209 // Receive the (4 Byte) "random" nonce from TAG
2210 if (!ReaderReceive(receivedAnswer, receivedAnswerPar))
2211 continue;
2212
2213 previous_nt = nt;
2214 nt = bytes_to_num(receivedAnswer, 4);
2215
2216 // Transmit reader nonce with fake par
2217 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2218
2219 WDT_HIT();
2220 LED_B_ON();
2221 if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
2222
2223 nt_distance = dist_nt(previous_nt, nt);
2224
2225 // if no distance between, then we are in sync.
2226 if (nt_distance == 0) {
2227 nt_attacked = nt;
2228 } else {
2229 if (nt_distance == -99999) { // invalid nonce received
2230 ++unexpected_random;
2231 if (unexpected_random > MAX_UNEXPECTED_RANDOM) {
2232 isOK = -3; // Card has an unpredictable PRNG. Give up
2233 break;
2234 } else {
2235 if (sync_cycles <= 0) sync_cycles += PRNG_SEQUENCE_LENGTH;
2236 LED_B_OFF();
2237 continue; // continue trying...
2238 }
2239 }
2240
2241 if (++sync_tries > MAX_SYNC_TRIES) {
2242 isOK = -4; // Card's PRNG runs at an unexpected frequency or resets unexpectedly
2243 break;
2244 }
2245
2246 sync_cycles = (sync_cycles - nt_distance)/elapsed_prng_sequences;
2247
2248 if (sync_cycles <= 0)
2249 sync_cycles += PRNG_SEQUENCE_LENGTH;
2250
2251 if (MF_DBGLEVEL >= 4)
2252 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);
2253
2254 LED_B_OFF();
2255 continue;
2256 }
2257 }
2258 LED_B_OFF();
2259
2260 if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
2261
2262 catch_up_cycles = ABS(dist_nt(nt_attacked, nt));
2263 if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one.
2264 catch_up_cycles = 0;
2265 continue;
2266 }
2267 // average?
2268 catch_up_cycles /= elapsed_prng_sequences;
2269
2270 if (catch_up_cycles == last_catch_up) {
2271 ++consecutive_resyncs;
2272 } else {
2273 last_catch_up = catch_up_cycles;
2274 consecutive_resyncs = 0;
2275 }
2276
2277 if (consecutive_resyncs < 3) {
2278 if (MF_DBGLEVEL >= 4)
2279 Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, catch_up_cycles, consecutive_resyncs);
2280 } else {
2281 sync_cycles += catch_up_cycles;
2282
2283 if (MF_DBGLEVEL >= 4)
2284 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);
2285
2286 last_catch_up = 0;
2287 catch_up_cycles = 0;
2288 consecutive_resyncs = 0;
2289 }
2290 continue;
2291 }
2292
2293 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2294 if (ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2295 catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2296
2297 if (nt_diff == 0)
2298 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
2299
2300 par_list[nt_diff] = SwapBits(par[0], 8);
2301 ks_list[nt_diff] = receivedAnswer[0] ^ 0x05; // xor with NACK value to get keystream
2302
2303 // Test if the information is complete
2304 if (nt_diff == 0x07) {
2305 isOK = 1;
2306 break;
2307 }
2308
2309 nt_diff = (nt_diff + 1) & 0x07;
2310 mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2311 par[0] = par_low;
2312
2313 } else {
2314 // No NACK.
2315 if (nt_diff == 0 && first_try) {
2316 par[0]++;
2317 if (par[0] == 0x00) { // tried all 256 possible parities without success. Card doesn't send NACK.
2318 isOK = -2;
2319 break;
2320 }
2321 } else {
2322 // Why this?
2323 par[0] = ((par[0] & 0x1F) + 1) | par_low;
2324 }
2325 }
2326
2327 // reset the resyncs since we got a complete transaction on right time.
2328 consecutive_resyncs = 0;
2329 } // end for loop
2330
2331 mf_nr_ar[3] &= 0x1F;
2332
2333 if (MF_DBGLEVEL >= 4) Dbprintf("Number of sent auth requestes: %u", i);
2334
2335 uint8_t buf[28] = {0x00};
2336 memset(buf, 0x00, sizeof(buf));
2337 num_to_bytes(cuid, 4, buf);
2338 num_to_bytes(nt, 4, buf + 4);
2339 memcpy(buf + 8, par_list, 8);
2340 memcpy(buf + 16, ks_list, 8);
2341 memcpy(buf + 24, mf_nr_ar, 4);
2342
2343 cmd_send(CMD_ACK, isOK, 0, 0, buf, sizeof(buf) );
2344
2345 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2346 LEDsoff();
2347 set_tracing(FALSE);
2348 }
2349
2350 /**
2351 *MIFARE 1K simulate.
2352 *
2353 *@param flags :
2354 * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2355 * FLAG_4B_UID_IN_DATA - use 4-byte UID in the data-section
2356 * FLAG_7B_UID_IN_DATA - use 7-byte UID in the data-section
2357 * FLAG_10B_UID_IN_DATA - use 10-byte UID in the data-section
2358 * FLAG_UID_IN_EMUL - use 4-byte UID from emulator memory
2359 * FLAG_NR_AR_ATTACK - collect NR_AR responses for bruteforcing later
2360 *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2361 */
2362 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain) {
2363 int cardSTATE = MFEMUL_NOFIELD;
2364 int _UID_LEN = 0; // 4, 7, 10
2365 int vHf = 0; // in mV
2366 int res = 0;
2367 uint32_t selTimer = 0;
2368 uint32_t authTimer = 0;
2369 uint16_t len = 0;
2370 uint8_t cardWRBL = 0;
2371 uint8_t cardAUTHSC = 0;
2372 uint8_t cardAUTHKEY = 0xff; // no authentication
2373 uint32_t cuid = 0;
2374 uint32_t ans = 0;
2375 uint32_t cardINTREG = 0;
2376 uint8_t cardINTBLOCK = 0;
2377 struct Crypto1State mpcs = {0, 0};
2378 struct Crypto1State *pcs;
2379 pcs = &mpcs;
2380 uint32_t numReads = 0; //Counts numer of times reader read a block
2381 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00};
2382 uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
2383 uint8_t response[MAX_MIFARE_FRAME_SIZE] = {0x00};
2384 uint8_t response_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
2385
2386 uint8_t atqa[] = {0x04, 0x00}; // Mifare classic 1k
2387 uint8_t sak_4[] = {0x0C, 0x00, 0x00}; // CL1 - 4b uid
2388 uint8_t sak_7[] = {0x0C, 0x00, 0x00}; // CL2 - 7b uid
2389 uint8_t sak_10[] = {0x0C, 0x00, 0x00}; // CL3 - 10b uid
2390 //uint8_t sak[] = {0x09, 0x3f, 0xcc }; // Mifare Mini
2391
2392 uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2393 uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2394 uint8_t rUIDBCC3[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2395
2396 uint8_t rAUTH_NT[] = {0x01, 0x01, 0x01, 0x01}; // very random nonce
2397 //uint8_t rAUTH_NT[] = {0x55, 0x41, 0x49, 0x92};// nonce from nested? why this?
2398 uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2399
2400 // Here, we collect CUID, NT, NR, AR, CUID2, NT2, NR2, AR2
2401 // This can be used in a reader-only attack.
2402 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0,0};
2403 uint8_t ar_nr_collected = 0;
2404
2405 // Authenticate response - nonce
2406 uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2407 ar_nr_responses[1] = nonce;
2408
2409 //-- Determine the UID
2410 // Can be set from emulator memory or incoming data
2411 // Length: 4,7,or 10 bytes
2412 if ( (flags & FLAG_UID_IN_EMUL) == FLAG_UID_IN_EMUL)
2413 emlGetMemBt(datain, 0, 10); // load 10bytes from EMUL to the datain pointer. to be used below.
2414
2415 if ( (flags & FLAG_4B_UID_IN_DATA) == FLAG_4B_UID_IN_DATA) {
2416 memcpy(rUIDBCC1, datain, 4);
2417 _UID_LEN = 4;
2418 } else if ( (flags & FLAG_7B_UID_IN_DATA) == FLAG_7B_UID_IN_DATA) {
2419 memcpy(&rUIDBCC1[1], datain, 3);
2420 memcpy( rUIDBCC2, datain+3, 4);
2421 _UID_LEN = 7;
2422 } else if ( (flags & FLAG_10B_UID_IN_DATA) == FLAG_10B_UID_IN_DATA) {
2423 memcpy(&rUIDBCC1[1], datain, 3);
2424 memcpy(&rUIDBCC2[1], datain+3, 3);
2425 memcpy( rUIDBCC3, datain+6, 4);
2426 _UID_LEN = 10;
2427 }
2428
2429 switch (_UID_LEN) {
2430 case 4:
2431 sak_4[0] &= 0xFB;
2432 // save CUID
2433 ar_nr_responses[0] = cuid = bytes_to_num(rUIDBCC1, 4);
2434 // BCC
2435 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2436 if (MF_DBGLEVEL >= 2) {
2437 Dbprintf("4B UID: %02x%02x%02x%02x",
2438 rUIDBCC1[0],
2439 rUIDBCC1[1],
2440 rUIDBCC1[2],
2441 rUIDBCC1[3]
2442 );
2443 }
2444 break;
2445 case 7:
2446 atqa[0] |= 0x40;
2447 sak_7[0] &= 0xFB;
2448 // save CUID
2449 ar_nr_responses[0] = cuid = bytes_to_num(rUIDBCC2, 4);
2450 // CascadeTag, CT
2451 rUIDBCC1[0] = 0x88;
2452 // BCC
2453 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2454 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2455 if (MF_DBGLEVEL >= 2) {
2456 Dbprintf("7B UID: %02x %02x %02x %02x %02x %02x %02x",
2457 rUIDBCC1[1],
2458 rUIDBCC1[2],
2459 rUIDBCC1[3],
2460 rUIDBCC2[0],
2461 rUIDBCC2[1],
2462 rUIDBCC2[2],
2463 rUIDBCC2[3]
2464 );
2465 }
2466 break;
2467 case 10:
2468 atqa[0] |= 0x80;
2469 sak_10[0] &= 0xFB;
2470 // save CUID
2471 ar_nr_responses[0] = cuid = bytes_to_num(rUIDBCC3, 4);
2472 // CascadeTag, CT
2473 rUIDBCC1[0] = 0x88;
2474 rUIDBCC2[0] = 0x88;
2475 // BCC
2476 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2477 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2478 rUIDBCC3[4] = rUIDBCC3[0] ^ rUIDBCC3[1] ^ rUIDBCC3[2] ^ rUIDBCC3[3];
2479
2480 if (MF_DBGLEVEL >= 2) {
2481 Dbprintf("10B UID: %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
2482 rUIDBCC1[1],
2483 rUIDBCC1[2],
2484 rUIDBCC1[3],
2485 rUIDBCC2[1],
2486 rUIDBCC2[2],
2487 rUIDBCC2[3],
2488 rUIDBCC3[0],
2489 rUIDBCC3[1],
2490 rUIDBCC3[2],
2491 rUIDBCC3[3]
2492 );
2493 }
2494 break;
2495 default:
2496 break;
2497 }
2498 // calc some crcs
2499 ComputeCrc14443(CRC_14443_A, sak_4, 1, &sak_4[1], &sak_4[2]);
2500 ComputeCrc14443(CRC_14443_A, sak_7, 1, &sak_7[1], &sak_7[2]);
2501 ComputeCrc14443(CRC_14443_A, sak_10, 1, &sak_10[1], &sak_10[2]);
2502
2503 // We need to listen to the high-frequency, peak-detected path.
2504 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2505
2506 // free eventually allocated BigBuf memory but keep Emulator Memory
2507 BigBuf_free_keep_EM();
2508 clear_trace();
2509 set_tracing(TRUE);
2510
2511 bool finished = FALSE;
2512 while (!BUTTON_PRESS() && !finished && !usb_poll_validate_length()) {
2513 WDT_HIT();
2514
2515 // find reader field
2516 if (cardSTATE == MFEMUL_NOFIELD) {
2517 vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
2518 if (vHf > MF_MINFIELDV) {
2519 cardSTATE_TO_IDLE();
2520 LED_A_ON();
2521 }
2522 }
2523 if (cardSTATE == MFEMUL_NOFIELD) continue;
2524
2525 //Now, get data
2526 res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
2527 if (res == 2) { //Field is off!
2528 cardSTATE = MFEMUL_NOFIELD;
2529 LEDsoff();
2530 continue;
2531 } else if (res == 1) {
2532 break; //return value 1 means button press
2533 }
2534
2535 // REQ or WUP request in ANY state and WUP in HALTED state
2536 // this if-statement doesn't match the specification above. (iceman)
2537 if (len == 1 && ((receivedCmd[0] == ISO14443A_CMD_REQA && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == ISO14443A_CMD_WUPA)) {
2538 selTimer = GetTickCount();
2539 EmSendCmdEx(atqa, sizeof(atqa), (receivedCmd[0] == ISO14443A_CMD_WUPA));
2540 cardSTATE = MFEMUL_SELECT1;
2541 crypto1_destroy(pcs);
2542 cardAUTHKEY = 0xff;
2543 LEDsoff();
2544 nonce++;
2545 continue;
2546 }
2547
2548 switch (cardSTATE) {
2549 case MFEMUL_NOFIELD:
2550 case MFEMUL_HALTED:
2551 case MFEMUL_IDLE:{
2552 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2553 break;
2554 }
2555 case MFEMUL_SELECT1:{
2556 if (len == 2 && (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT && receivedCmd[1] == 0x20)) {
2557 if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received");
2558 EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2559 break;
2560 }
2561 // select card
2562 if (len == 9 &&
2563 ( receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT &&
2564 receivedCmd[1] == 0x70 &&
2565 memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2566
2567 // SAK 4b
2568 EmSendCmd(sak_4, sizeof(sak_4));
2569 switch(_UID_LEN){
2570 case 4:
2571 cardSTATE = MFEMUL_WORK;
2572 LED_B_ON();
2573 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2574 continue;
2575 case 7:
2576 case 10:
2577 cardSTATE = MFEMUL_SELECT2;
2578 continue;
2579 default:break;
2580 }
2581 } else {
2582 cardSTATE_TO_IDLE();
2583 }
2584 break;
2585 }
2586 case MFEMUL_SELECT2:{
2587 if (!len) {
2588 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2589 break;
2590 }
2591 if (len == 2 && (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2 && receivedCmd[1] == 0x20)) {
2592 EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2593 break;
2594 }
2595 if (len == 9 &&
2596 (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2 &&
2597 receivedCmd[1] == 0x70 &&
2598 memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0) ) {
2599
2600 EmSendCmd(sak_7, sizeof(sak_7));
2601 switch(_UID_LEN){
2602 case 7:
2603 cardSTATE = MFEMUL_WORK;
2604 LED_B_ON();
2605 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2606 continue;
2607 case 10:
2608 cardSTATE = MFEMUL_SELECT3;
2609 continue;
2610 default:break;
2611 }
2612 }
2613 cardSTATE_TO_IDLE();
2614 break;
2615 }
2616 case MFEMUL_SELECT3:{
2617 if (!len) {
2618 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2619 break;
2620 }
2621 if (len == 2 && (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_3 && receivedCmd[1] == 0x20)) {
2622 EmSendCmd(rUIDBCC3, sizeof(rUIDBCC3));
2623 break;
2624 }
2625 if (len == 9 &&
2626 (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_3 &&
2627 receivedCmd[1] == 0x70 &&
2628 memcmp(&receivedCmd[2], rUIDBCC3, 4) == 0) ) {
2629
2630 EmSendCmd(sak_10, sizeof(sak_10));
2631 cardSTATE = MFEMUL_WORK;
2632 LED_B_ON();
2633 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol3 time: %d", GetTickCount() - selTimer);
2634 break;
2635 }
2636 cardSTATE_TO_IDLE();
2637 break;
2638 }
2639 case MFEMUL_AUTH1:{
2640 if( len != 8) {
2641 cardSTATE_TO_IDLE();
2642 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2643 break;
2644 }
2645
2646 uint32_t nr = bytes_to_num(receivedCmd, 4);
2647 uint32_t ar = bytes_to_num(&receivedCmd[4], 4);
2648
2649 //Collect AR/NR
2650 //if(ar_nr_collected < 2 && cardAUTHSC == 2){
2651 if(ar_nr_collected < 2) {
2652 //if(ar_nr_responses[2] != nr) {
2653 ar_nr_responses[ar_nr_collected*4] = cuid;
2654 ar_nr_responses[ar_nr_collected*4+1] = nonce;
2655 ar_nr_responses[ar_nr_collected*4+2] = nr;
2656 ar_nr_responses[ar_nr_collected*4+3] = ar;
2657 ar_nr_collected++;
2658 //}
2659
2660 // Interactive mode flag, means we need to send ACK
2661 finished = ( ((flags & FLAG_INTERACTIVE) == FLAG_INTERACTIVE)&& ar_nr_collected == 2);
2662 }
2663 /*
2664 crypto1_word(pcs, ar , 1);
2665 cardRr = nr ^ crypto1_word(pcs, 0, 0);
2666
2667 test if auth OK
2668 if (cardRr != prng_successor(nonce, 64)){
2669
2670 if (MF_DBGLEVEL >= 4) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
2671 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2672 cardRr, prng_successor(nonce, 64));
2673 Shouldn't we respond anything here?
2674 Right now, we don't nack or anything, which causes the
2675 reader to do a WUPA after a while. /Martin
2676 -- which is the correct response. /piwi
2677 cardSTATE_TO_IDLE();
2678 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2679 break;
2680 }
2681 */
2682
2683 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2684 num_to_bytes(ans, 4, rAUTH_AT);
2685 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2686 LED_C_ON();
2687
2688 if (MF_DBGLEVEL >= 4) {
2689 Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2690 cardAUTHSC,
2691 cardAUTHKEY == 0 ? 'A' : 'B',
2692 GetTickCount() - authTimer
2693 );
2694 }
2695 cardSTATE = MFEMUL_WORK;
2696 break;
2697 }
2698 case MFEMUL_WORK:{
2699 if (len == 0) {
2700 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2701 break;
2702 }
2703 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2704
2705 if(encrypted_data)
2706 mf_crypto1_decrypt(pcs, receivedCmd, len);
2707
2708 if (len == 4 && (receivedCmd[0] == MIFARE_AUTH_KEYA ||
2709 receivedCmd[0] == MIFARE_AUTH_KEYB) ) {
2710
2711 authTimer = GetTickCount();
2712 cardAUTHSC = receivedCmd[1] / 4; // received block num
2713 cardAUTHKEY = receivedCmd[0] - 0x60; // & 1
2714 crypto1_destroy(pcs);
2715 crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2716
2717 if (!encrypted_data) {
2718 // first authentication
2719 crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
2720 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2721
2722 if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2723
2724 } else {
2725 // nested authentication
2726 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2727 num_to_bytes(ans, 4, rAUTH_AT);
2728
2729 if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2730 }
2731
2732 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2733 cardSTATE = MFEMUL_AUTH1;
2734 break;
2735 }
2736
2737 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2738 // BUT... ACK --> NACK
2739 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2740 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2741 break;
2742 }
2743
2744 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2745 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2746 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2747 break;
2748 }
2749
2750 if(len != 4) {
2751 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2752 break;
2753 }
2754
2755 if ( receivedCmd[0] == ISO14443A_CMD_READBLOCK ||
2756 receivedCmd[0] == ISO14443A_CMD_WRITEBLOCK ||
2757 receivedCmd[0] == MIFARE_CMD_INC ||
2758 receivedCmd[0] == MIFARE_CMD_DEC ||
2759 receivedCmd[0] == MIFARE_CMD_RESTORE ||
2760 receivedCmd[0] == MIFARE_CMD_TRANSFER ) {
2761
2762 if (receivedCmd[1] >= 16 * 4) {
2763 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2764 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]);
2765 break;
2766 }
2767
2768 if (receivedCmd[1] / 4 != cardAUTHSC) {
2769 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2770 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);
2771 break;
2772 }
2773 }
2774 // read block
2775 if (receivedCmd[0] == ISO14443A_CMD_READBLOCK) {
2776 if (MF_DBGLEVEL >= 4) Dbprintf("Reader reading block %d (0x%02x)", receivedCmd[1], receivedCmd[1]);
2777
2778 emlGetMem(response, receivedCmd[1], 1);
2779 AppendCrc14443a(response, 16);
2780 mf_crypto1_encrypt(pcs, response, 18, response_par);
2781 EmSendCmdPar(response, 18, response_par);
2782 numReads++;
2783 if(exitAfterNReads > 0 && numReads >= exitAfterNReads) {
2784 Dbprintf("%d reads done, exiting", numReads);
2785 finished = true;
2786 }
2787 break;
2788 }
2789 // write block
2790 if (receivedCmd[0] == ISO14443A_CMD_WRITEBLOCK) {
2791 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)", receivedCmd[1], receivedCmd[1]);
2792 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2793 cardSTATE = MFEMUL_WRITEBL2;
2794 cardWRBL = receivedCmd[1];
2795 break;
2796 }
2797 // increment, decrement, restore
2798 if ( receivedCmd[0] == MIFARE_CMD_INC ||
2799 receivedCmd[0] == MIFARE_CMD_DEC ||
2800 receivedCmd[0] == MIFARE_CMD_RESTORE) {
2801
2802 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0], receivedCmd[1], receivedCmd[1]);
2803
2804 if (emlCheckValBl(receivedCmd[1])) {
2805 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2806 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2807 break;
2808 }
2809 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2810 if (receivedCmd[0] == MIFARE_CMD_INC) cardSTATE = MFEMUL_INTREG_INC;
2811 if (receivedCmd[0] == MIFARE_CMD_DEC) cardSTATE = MFEMUL_INTREG_DEC;
2812 if (receivedCmd[0] == MIFARE_CMD_RESTORE) cardSTATE = MFEMUL_INTREG_REST;
2813 cardWRBL = receivedCmd[1];
2814 break;
2815 }
2816 // transfer
2817 if (receivedCmd[0] == MIFARE_CMD_TRANSFER) {
2818 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)", receivedCmd[0], receivedCmd[1], receivedCmd[1]);
2819 if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2820 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2821 else
2822 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2823 break;
2824 }
2825 // halt
2826 if (receivedCmd[0] == ISO14443A_CMD_HALT && receivedCmd[1] == 0x00) {
2827 LED_B_OFF();
2828 LED_C_OFF();
2829 cardSTATE = MFEMUL_HALTED;
2830 if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer);
2831 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2832 break;
2833 }
2834 // RATS
2835 if (receivedCmd[0] == ISO14443A_CMD_RATS) {
2836 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2837 break;
2838 }
2839 // command not allowed
2840 if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking");
2841 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2842 break;
2843 }
2844 case MFEMUL_WRITEBL2:{
2845 if (len == 18) {
2846 mf_crypto1_decrypt(pcs, receivedCmd, len);
2847 emlSetMem(receivedCmd, cardWRBL, 1);
2848 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2849 cardSTATE = MFEMUL_WORK;
2850 } else {
2851 cardSTATE_TO_IDLE();
2852 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2853 }
2854 break;
2855 }
2856 case MFEMUL_INTREG_INC:{
2857 mf_crypto1_decrypt(pcs, receivedCmd, len);
2858 memcpy(&ans, receivedCmd, 4);
2859 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2860 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2861 cardSTATE_TO_IDLE();
2862 break;
2863 }
2864 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2865 cardINTREG = cardINTREG + ans;
2866 cardSTATE = MFEMUL_WORK;
2867 break;
2868 }
2869 case MFEMUL_INTREG_DEC:{
2870 mf_crypto1_decrypt(pcs, receivedCmd, len);
2871 memcpy(&ans, receivedCmd, 4);
2872 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2873 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2874 cardSTATE_TO_IDLE();
2875 break;
2876 }
2877 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2878 cardINTREG = cardINTREG - ans;
2879 cardSTATE = MFEMUL_WORK;
2880 break;
2881 }
2882 case MFEMUL_INTREG_REST:{
2883 mf_crypto1_decrypt(pcs, receivedCmd, len);
2884 memcpy(&ans, receivedCmd, 4);
2885 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2886 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2887 cardSTATE_TO_IDLE();
2888 break;
2889 }
2890 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2891 cardSTATE = MFEMUL_WORK;
2892 break;
2893 }
2894 }
2895 }
2896
2897 // Interactive mode flag, means we need to send ACK
2898 if((flags & FLAG_INTERACTIVE) == FLAG_INTERACTIVE) {
2899 //May just aswell send the collected ar_nr in the response aswell
2900 uint8_t len = ar_nr_collected * 4 * 4;
2901 cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, len, 0, &ar_nr_responses, len);
2902 }
2903
2904 if( ((flags & FLAG_NR_AR_ATTACK) == FLAG_NR_AR_ATTACK ) && MF_DBGLEVEL >= 1 ) {
2905 if(ar_nr_collected > 1 ) {
2906 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
2907 Dbprintf("../tools/mfkey/mfkey32v2.exe %08x %08x %08x %08x %08x %08x %08x",
2908 ar_nr_responses[0], // CUID
2909 ar_nr_responses[1], // NT1
2910 ar_nr_responses[2], // NR1
2911 ar_nr_responses[3], // AR1
2912 //ar_nr_responses[4], // CUID2
2913 ar_nr_responses[5], // NT2
2914 ar_nr_responses[6], // NR2
2915 ar_nr_responses[7] // AR2
2916 );
2917 } else {
2918 Dbprintf("Failed to obtain two AR/NR pairs!");
2919 if(ar_nr_collected == 1 ) {
2920 Dbprintf("Only got these: UID=%08x, nonce=%08x, NR1=%08x, AR1=%08x",
2921 ar_nr_responses[0], // CUID
2922 ar_nr_responses[1], // NT
2923 ar_nr_responses[2], // NR1
2924 ar_nr_responses[3] // AR1
2925 );
2926 }
2927 }
2928 }
2929 if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen());
2930
2931 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2932 LEDsoff();
2933 set_tracing(FALSE);
2934 }
2935
2936
2937 //-----------------------------------------------------------------------------
2938 // MIFARE sniffer.
2939 //
2940 // if no activity for 2sec, it sends the collected data to the client.
2941 //-----------------------------------------------------------------------------
2942 // "hf mf sniff"
2943 void RAMFUNC SniffMifare(uint8_t param) {
2944
2945 LEDsoff();
2946
2947 // free eventually allocated BigBuf memory
2948 BigBuf_free(); BigBuf_Clear_ext(false);
2949 clear_trace();
2950 set_tracing(TRUE);
2951
2952 // The command (reader -> tag) that we're receiving.
2953 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00};
2954 uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
2955
2956 // The response (tag -> reader) that we're receiving.
2957 uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE] = {0x00};
2958 uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE] = {0x00};
2959
2960 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
2961
2962 // allocate the DMA buffer, used to stream samples from the FPGA
2963 // [iceman] is this sniffed data unsigned?
2964 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
2965 uint8_t *data = dmaBuf;
2966 uint8_t previous_data = 0;
2967 int maxDataLen = 0;
2968 int dataLen = 0;
2969 bool ReaderIsActive = FALSE;
2970 bool TagIsActive = FALSE;
2971
2972 // Set up the demodulator for tag -> reader responses.
2973 DemodInit(receivedResponse, receivedResponsePar);
2974
2975 // Set up the demodulator for the reader -> tag commands
2976 UartInit(receivedCmd, receivedCmdPar);
2977
2978 // Setup and start DMA.
2979 // set transfer address and number of bytes. Start transfer.
2980 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, DMA_BUFFER_SIZE) ){
2981 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
2982 return;
2983 }
2984
2985 LED_D_OFF();
2986
2987 MfSniffInit();
2988
2989 // And now we loop, receiving samples.
2990 for(uint32_t sniffCounter = 0;; ) {
2991
2992 LED_A_ON();
2993 WDT_HIT();
2994
2995 if(BUTTON_PRESS()) {
2996 DbpString("cancelled by button");
2997 break;
2998 }
2999
3000 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
3001 // check if a transaction is completed (timeout after 2000ms).
3002 // if yes, stop the DMA transfer and send what we have so far to the client
3003 if (MfSniffSend(2000)) {
3004 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
3005 sniffCounter = 0;
3006 data = dmaBuf;
3007 maxDataLen = 0;
3008 ReaderIsActive = FALSE;
3009 TagIsActive = FALSE;
3010 // Setup and start DMA. set transfer address and number of bytes. Start transfer.
3011 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, DMA_BUFFER_SIZE) ){
3012 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
3013 return;
3014 }
3015 }
3016 }
3017
3018 int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
3019 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
3020
3021 if (readBufDataP <= dmaBufDataP) // we are processing the same block of data which is currently being transferred
3022 dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
3023 else
3024 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
3025
3026 // test for length of buffer
3027 if(dataLen > maxDataLen) { // we are more behind than ever...
3028 maxDataLen = dataLen;
3029 if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
3030 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
3031 break;
3032 }
3033 }
3034 if(dataLen < 1) continue;
3035
3036 // primary buffer was stopped ( <-- we lost data!
3037 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
3038 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
3039 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
3040 Dbprintf("RxEmpty ERROR, data length:%d", dataLen); // temporary
3041 }
3042 // secondary buffer sets as primary, secondary buffer was stopped
3043 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
3044 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
3045 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
3046 }
3047
3048 LED_A_OFF();
3049
3050 if (sniffCounter & 0x01) {
3051
3052 // no need to try decoding tag data if the reader is sending
3053 if(!TagIsActive) {
3054 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
3055 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
3056 LED_C_INV();
3057
3058 if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
3059
3060 UartInit(receivedCmd, receivedCmdPar);
3061 DemodReset();
3062 }
3063 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
3064 }
3065
3066 // no need to try decoding tag data if the reader is sending
3067 if(!ReaderIsActive) {
3068 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
3069 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
3070 LED_C_INV();
3071
3072 if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
3073
3074 DemodReset();
3075 UartInit(receivedCmd, receivedCmdPar);
3076 }
3077 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
3078 }
3079 }
3080
3081 previous_data = *data;
3082 sniffCounter++;
3083 data++;
3084
3085 if(data == dmaBuf + DMA_BUFFER_SIZE)
3086 data = dmaBuf;
3087
3088 } // main cycle
3089
3090 if (MF_DBGLEVEL >= 1) Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
3091
3092 FpgaDisableSscDma();
3093 MfSniffEnd();
3094 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
3095 LEDsoff();
3096 set_tracing(FALSE);
3097 }
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