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CHG: minor correction to the em410xsim help text.
[proxmark3-svn] / armsrc / iso14443a.c
1 //-----------------------------------------------------------------------------
2 // Merlok - June 2011, 2012
3 // Gerhard de Koning Gans - May 2008
4 // Hagen Fritsch - June 2010
5 //
6 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
7 // at your option, any later version. See the LICENSE.txt file for the text of
8 // the license.
9 //-----------------------------------------------------------------------------
10 // Routines to support ISO 14443 type A.
11 //-----------------------------------------------------------------------------
12
13 #include "proxmark3.h"
14 #include "apps.h"
15 #include "util.h"
16 #include "string.h"
17 #include "cmd.h"
18 #include "iso14443crc.h"
19 #include "iso14443a.h"
20 #include "crapto1.h"
21 #include "mifareutil.h"
22 #include "BigBuf.h"
23 static uint32_t iso14a_timeout;
24 int rsamples = 0;
25 uint8_t trigger = 0;
26 // the block number for the ISO14443-4 PCB
27 static uint8_t iso14_pcb_blocknum = 0;
28
29 //
30 // ISO14443 timing:
31 //
32 // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
33 #define REQUEST_GUARD_TIME (7000/16 + 1)
34 // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
35 #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
36 // bool LastCommandWasRequest = FALSE;
37
38 //
39 // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
40 //
41 // When the PM acts as reader and is receiving tag data, it takes
42 // 3 ticks delay in the AD converter
43 // 16 ticks until the modulation detector completes and sets curbit
44 // 8 ticks until bit_to_arm is assigned from curbit
45 // 8*16 ticks for the transfer from FPGA to ARM
46 // 4*16 ticks until we measure the time
47 // - 8*16 ticks because we measure the time of the previous transfer
48 #define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
49
50 // When the PM acts as a reader and is sending, it takes
51 // 4*16 ticks until we can write data to the sending hold register
52 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
53 // 8 ticks until the first transfer starts
54 // 8 ticks later the FPGA samples the data
55 // 1 tick to assign mod_sig_coil
56 #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
57
58 // When the PM acts as tag and is receiving it takes
59 // 2 ticks delay in the RF part (for the first falling edge),
60 // 3 ticks for the A/D conversion,
61 // 8 ticks on average until the start of the SSC transfer,
62 // 8 ticks until the SSC samples the first data
63 // 7*16 ticks to complete the transfer from FPGA to ARM
64 // 8 ticks until the next ssp_clk rising edge
65 // 4*16 ticks until we measure the time
66 // - 8*16 ticks because we measure the time of the previous transfer
67 #define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
68
69 // The FPGA will report its internal sending delay in
70 uint16_t FpgaSendQueueDelay;
71 // the 5 first bits are the number of bits buffered in mod_sig_buf
72 // the last three bits are the remaining ticks/2 after the mod_sig_buf shift
73 #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
74
75 // When the PM acts as tag and is sending, it takes
76 // 4*16 ticks until we can write data to the sending hold register
77 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
78 // 8 ticks until the first transfer starts
79 // 8 ticks later the FPGA samples the data
80 // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
81 // + 1 tick to assign mod_sig_coil
82 #define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
83
84 // When the PM acts as sniffer and is receiving tag data, it takes
85 // 3 ticks A/D conversion
86 // 14 ticks to complete the modulation detection
87 // 8 ticks (on average) until the result is stored in to_arm
88 // + the delays in transferring data - which is the same for
89 // sniffing reader and tag data and therefore not relevant
90 #define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
91
92 // When the PM acts as sniffer and is receiving reader data, it takes
93 // 2 ticks delay in analogue RF receiver (for the falling edge of the
94 // start bit, which marks the start of the communication)
95 // 3 ticks A/D conversion
96 // 8 ticks on average until the data is stored in to_arm.
97 // + the delays in transferring data - which is the same for
98 // sniffing reader and tag data and therefore not relevant
99 #define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
100
101 //variables used for timing purposes:
102 //these are in ssp_clk cycles:
103 static uint32_t NextTransferTime;
104 static uint32_t LastTimeProxToAirStart;
105 static uint32_t LastProxToAirDuration;
106
107
108
109 // CARD TO READER - manchester
110 // Sequence D: 11110000 modulation with subcarrier during first half
111 // Sequence E: 00001111 modulation with subcarrier during second half
112 // Sequence F: 00000000 no modulation with subcarrier
113 // READER TO CARD - miller
114 // Sequence X: 00001100 drop after half a period
115 // Sequence Y: 00000000 no drop
116 // Sequence Z: 11000000 drop at start
117 #define SEC_D 0xf0
118 #define SEC_E 0x0f
119 #define SEC_F 0x00
120 #define SEC_X 0x0c
121 #define SEC_Y 0x00
122 #define SEC_Z 0xc0
123
124 const uint8_t OddByteParity[256] = {
125 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
126 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
127 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
128 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
129 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
130 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
131 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
132 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
133 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
134 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
135 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
136 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
137 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
138 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
139 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
140 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1
141 };
142
143
144 void iso14a_set_trigger(bool enable) {
145 trigger = enable;
146 }
147
148
149 void iso14a_set_timeout(uint32_t timeout) {
150 iso14a_timeout = timeout;
151 if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
152 }
153
154
155 void iso14a_set_ATS_timeout(uint8_t *ats) {
156
157 uint8_t tb1;
158 uint8_t fwi;
159 uint32_t fwt;
160
161 if (ats[0] > 1) { // there is a format byte T0
162 if ((ats[1] & 0x20) == 0x20) { // there is an interface byte TB(1)
163 if ((ats[1] & 0x10) == 0x10) { // there is an interface byte TA(1) preceding TB(1)
164 tb1 = ats[3];
165 } else {
166 tb1 = ats[2];
167 }
168 fwi = (tb1 & 0xf0) >> 4; // frame waiting indicator (FWI)
169 fwt = 256 * 16 * (1 << fwi); // frame waiting time (FWT) in 1/fc
170
171 iso14a_set_timeout(fwt/(8*16));
172 }
173 }
174 }
175
176
177 //-----------------------------------------------------------------------------
178 // Generate the parity value for a byte sequence
179 //
180 //-----------------------------------------------------------------------------
181 byte_t oddparity (const byte_t bt)
182 {
183 return OddByteParity[bt];
184 }
185
186 void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par)
187 {
188 uint16_t paritybit_cnt = 0;
189 uint16_t paritybyte_cnt = 0;
190 uint8_t parityBits = 0;
191
192 for (uint16_t i = 0; i < iLen; i++) {
193 // Generate the parity bits
194 parityBits |= ((OddByteParity[pbtCmd[i]]) << (7-paritybit_cnt));
195 if (paritybit_cnt == 7) {
196 par[paritybyte_cnt] = parityBits; // save 8 Bits parity
197 parityBits = 0; // and advance to next Parity Byte
198 paritybyte_cnt++;
199 paritybit_cnt = 0;
200 } else {
201 paritybit_cnt++;
202 }
203 }
204
205 // save remaining parity bits
206 par[paritybyte_cnt] = parityBits;
207
208 }
209
210 void AppendCrc14443a(uint8_t* data, int len)
211 {
212 ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
213 }
214
215 void AppendCrc14443b(uint8_t* data, int len)
216 {
217 ComputeCrc14443(CRC_14443_B,data,len,data+len,data+len+1);
218 }
219
220
221 //=============================================================================
222 // ISO 14443 Type A - Miller decoder
223 //=============================================================================
224 // Basics:
225 // This decoder is used when the PM3 acts as a tag.
226 // The reader will generate "pauses" by temporarily switching of the field.
227 // At the PM3 antenna we will therefore measure a modulated antenna voltage.
228 // The FPGA does a comparison with a threshold and would deliver e.g.:
229 // ........ 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 .......
230 // The Miller decoder needs to identify the following sequences:
231 // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0")
232 // 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information")
233 // 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1")
234 // Note 1: the bitstream may start at any time. We therefore need to sync.
235 // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
236 //-----------------------------------------------------------------------------
237 static tUart Uart;
238
239 // Lookup-Table to decide if 4 raw bits are a modulation.
240 // We accept the following:
241 // 0001 - a 3 tick wide pause
242 // 0011 - a 2 tick wide pause, or a three tick wide pause shifted left
243 // 0111 - a 2 tick wide pause shifted left
244 // 1001 - a 2 tick wide pause shifted right
245 const bool Mod_Miller_LUT[] = {
246 FALSE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, TRUE,
247 FALSE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
248 };
249 #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4])
250 #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)])
251
252 void UartReset()
253 {
254 Uart.state = STATE_UNSYNCD;
255 Uart.bitCount = 0;
256 Uart.len = 0; // number of decoded data bytes
257 Uart.parityLen = 0; // number of decoded parity bytes
258 Uart.shiftReg = 0; // shiftreg to hold decoded data bits
259 Uart.parityBits = 0; // holds 8 parity bits
260 Uart.startTime = 0;
261 Uart.endTime = 0;
262
263 Uart.byteCntMax = 0;
264 Uart.posCnt = 0;
265 Uart.syncBit = 9999;
266 }
267
268 void UartInit(uint8_t *data, uint8_t *parity)
269 {
270 Uart.output = data;
271 Uart.parity = parity;
272 Uart.fourBits = 0x00000000; // clear the buffer for 4 Bits
273 UartReset();
274 }
275
276 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
277 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
278 {
279
280 Uart.fourBits = (Uart.fourBits << 8) | bit;
281
282 if (Uart.state == STATE_UNSYNCD) { // not yet synced
283
284 Uart.syncBit = 9999; // not set
285
286 // 00x11111 2|3 ticks pause followed by 6|5 ticks unmodulated Sequence Z (a "0" or "start of communication")
287 // 11111111 8 ticks unmodulation Sequence Y (a "0" or "end of communication" or "no information")
288 // 111100x1 4 ticks unmodulated followed by 2|3 ticks pause Sequence X (a "1")
289
290 // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from
291 // Sequence X followed by Sequence Y followed by Sequence Z (111100x1 11111111 00x11111)
292 // we therefore look for a ...xx1111 11111111 00x11111xxxxxx... pattern
293 // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's)
294 //
295 #define ISO14443A_STARTBIT_MASK 0x07FFEF80 // mask is 00001111 11111111 1110 1111 10000000
296 #define ISO14443A_STARTBIT_PATTERN 0x07FF8F80 // pattern is 00001111 11111111 1000 1111 10000000
297
298 if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7;
299 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6;
300 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5;
301 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4;
302 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3;
303 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2;
304 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1;
305 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0;
306
307 if (Uart.syncBit != 9999) { // found a sync bit
308 Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
309 Uart.startTime -= Uart.syncBit;
310 Uart.endTime = Uart.startTime;
311 Uart.state = STATE_START_OF_COMMUNICATION;
312 }
313
314 } else {
315
316 if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) {
317 if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation in both halves - error
318 UartReset();
319 } else { // Modulation in first half = Sequence Z = logic "0"
320 if (Uart.state == STATE_MILLER_X) { // error - must not follow after X
321 UartReset();
322 } else {
323 Uart.bitCount++;
324 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
325 Uart.state = STATE_MILLER_Z;
326 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
327 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
328 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
329 Uart.parityBits <<= 1; // make room for the parity bit
330 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
331 Uart.bitCount = 0;
332 Uart.shiftReg = 0;
333 if((Uart.len&0x0007) == 0) { // every 8 data bytes
334 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
335 Uart.parityBits = 0;
336 }
337 }
338 }
339 }
340 } else {
341 if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1"
342 Uart.bitCount++;
343 Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg
344 Uart.state = STATE_MILLER_X;
345 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
346 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
347 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
348 Uart.parityBits <<= 1; // make room for the new parity bit
349 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
350 Uart.bitCount = 0;
351 Uart.shiftReg = 0;
352 if ((Uart.len&0x0007) == 0) { // every 8 data bytes
353 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
354 Uart.parityBits = 0;
355 }
356 }
357 } else { // no modulation in both halves - Sequence Y
358 if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication
359 Uart.state = STATE_UNSYNCD;
360 Uart.bitCount--; // last "0" was part of EOC sequence
361 Uart.shiftReg <<= 1; // drop it
362 if(Uart.bitCount > 0) { // if we decoded some bits
363 Uart.shiftReg >>= (9 - Uart.bitCount); // right align them
364 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); // add last byte to the output
365 Uart.parityBits <<= 1; // add a (void) parity bit
366 Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align parity bits
367 Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store it
368 return TRUE;
369 } else if (Uart.len & 0x0007) { // there are some parity bits to store
370 Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align remaining parity bits
371 Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store them
372 }
373 if (Uart.len) {
374 return TRUE; // we are finished with decoding the raw data sequence
375 } else {
376 UartReset(); // Nothing received - start over
377 }
378 }
379 if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC
380 UartReset();
381 } else { // a logic "0"
382 Uart.bitCount++;
383 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
384 Uart.state = STATE_MILLER_Y;
385 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
386 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
387 Uart.parityBits <<= 1; // make room for the parity bit
388 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
389 Uart.bitCount = 0;
390 Uart.shiftReg = 0;
391 if ((Uart.len&0x0007) == 0) { // every 8 data bytes
392 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
393 Uart.parityBits = 0;
394 }
395 }
396 }
397 }
398 }
399
400 }
401
402 return FALSE; // not finished yet, need more data
403 }
404
405
406
407 //=============================================================================
408 // ISO 14443 Type A - Manchester decoder
409 //=============================================================================
410 // Basics:
411 // This decoder is used when the PM3 acts as a reader.
412 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
413 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
414 // ........ 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 .......
415 // The Manchester decoder needs to identify the following sequences:
416 // 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication")
417 // 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0
418 // 8 ticks unmodulated: Sequence F = end of communication
419 // 8 ticks modulated: A collision. Save the collision position and treat as Sequence D
420 // Note 1: the bitstream may start at any time. We therefore need to sync.
421 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
422 static tDemod Demod;
423
424 // Lookup-Table to decide if 4 raw bits are a modulation.
425 // We accept three or four "1" in any position
426 const bool Mod_Manchester_LUT[] = {
427 FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
428 FALSE, FALSE, FALSE, TRUE, FALSE, TRUE, TRUE, TRUE
429 };
430
431 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
432 #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
433
434
435 void DemodReset()
436 {
437 Demod.state = DEMOD_UNSYNCD;
438 Demod.len = 0; // number of decoded data bytes
439 Demod.parityLen = 0;
440 Demod.shiftReg = 0; // shiftreg to hold decoded data bits
441 Demod.parityBits = 0; //
442 Demod.collisionPos = 0; // Position of collision bit
443 Demod.twoBits = 0xffff; // buffer for 2 Bits
444 Demod.highCnt = 0;
445 Demod.startTime = 0;
446 Demod.endTime = 0;
447
448 //
449 Demod.bitCount = 0;
450 Demod.syncBit = 0xFFFF;
451 Demod.samples = 0;
452 }
453
454 void DemodInit(uint8_t *data, uint8_t *parity)
455 {
456 Demod.output = data;
457 Demod.parity = parity;
458 DemodReset();
459 }
460
461 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
462 static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
463 {
464
465 Demod.twoBits = (Demod.twoBits << 8) | bit;
466
467 if (Demod.state == DEMOD_UNSYNCD) {
468
469 if (Demod.highCnt < 2) { // wait for a stable unmodulated signal
470 if (Demod.twoBits == 0x0000) {
471 Demod.highCnt++;
472 } else {
473 Demod.highCnt = 0;
474 }
475 } else {
476 Demod.syncBit = 0xFFFF; // not set
477 if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
478 else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
479 else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
480 else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
481 else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
482 else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
483 else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
484 else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
485 if (Demod.syncBit != 0xFFFF) {
486 Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
487 Demod.startTime -= Demod.syncBit;
488 Demod.bitCount = offset; // number of decoded data bits
489 Demod.state = DEMOD_MANCHESTER_DATA;
490 }
491 }
492
493 } else {
494
495 if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half
496 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... and in second half = collision
497 if (!Demod.collisionPos) {
498 Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
499 }
500 } // modulation in first half only - Sequence D = 1
501 Demod.bitCount++;
502 Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg
503 if(Demod.bitCount == 9) { // if we decoded a full byte (including parity)
504 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
505 Demod.parityBits <<= 1; // make room for the parity bit
506 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
507 Demod.bitCount = 0;
508 Demod.shiftReg = 0;
509 if((Demod.len&0x0007) == 0) { // every 8 data bytes
510 Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits
511 Demod.parityBits = 0;
512 }
513 }
514 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
515 } else { // no modulation in first half
516 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // and modulation in second half = Sequence E = 0
517 Demod.bitCount++;
518 Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg
519 if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity)
520 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
521 Demod.parityBits <<= 1; // make room for the new parity bit
522 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
523 Demod.bitCount = 0;
524 Demod.shiftReg = 0;
525 if ((Demod.len&0x0007) == 0) { // every 8 data bytes
526 Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits1
527 Demod.parityBits = 0;
528 }
529 }
530 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
531 } else { // no modulation in both halves - End of communication
532 if(Demod.bitCount > 0) { // there are some remaining data bits
533 Demod.shiftReg >>= (9 - Demod.bitCount); // right align the decoded bits
534 Demod.output[Demod.len++] = Demod.shiftReg & 0xff; // and add them to the output
535 Demod.parityBits <<= 1; // add a (void) parity bit
536 Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
537 Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
538 return TRUE;
539 } else if (Demod.len & 0x0007) { // there are some parity bits to store
540 Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
541 Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
542 }
543 if (Demod.len) {
544 return TRUE; // we are finished with decoding the raw data sequence
545 } else { // nothing received. Start over
546 DemodReset();
547 }
548 }
549 }
550 }
551 return FALSE; // not finished yet, need more data
552 }
553
554 //=============================================================================
555 // Finally, a `sniffer' for ISO 14443 Type A
556 // Both sides of communication!
557 //=============================================================================
558
559 //-----------------------------------------------------------------------------
560 // Record the sequence of commands sent by the reader to the tag, with
561 // triggering so that we start recording at the point that the tag is moved
562 // near the reader.
563 //-----------------------------------------------------------------------------
564 void RAMFUNC SnoopIso14443a(uint8_t param) {
565 // param:
566 // bit 0 - trigger from first card answer
567 // bit 1 - trigger from first reader 7-bit request
568
569 LEDsoff();
570
571 // We won't start recording the frames that we acquire until we trigger;
572 // a good trigger condition to get started is probably when we see a
573 // response from the tag.
574 // triggered == FALSE -- to wait first for card
575 bool triggered = !(param & 0x03);
576
577 // Allocate memory from BigBuf for some buffers
578 // free all previous allocations first
579 BigBuf_free();
580
581 // The command (reader -> tag) that we're receiving.
582 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
583 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
584
585 // The response (tag -> reader) that we're receiving.
586 uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
587 uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE);
588
589 // The DMA buffer, used to stream samples from the FPGA
590 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
591
592 // init trace buffer
593 clear_trace();
594 set_tracing(TRUE);
595
596 uint8_t *data = dmaBuf;
597 uint8_t previous_data = 0;
598 int maxDataLen = 0;
599 int dataLen = 0;
600 bool TagIsActive = FALSE;
601 bool ReaderIsActive = FALSE;
602
603 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
604
605 // Set up the demodulator for tag -> reader responses.
606 DemodInit(receivedResponse, receivedResponsePar);
607
608 // Set up the demodulator for the reader -> tag commands
609 UartInit(receivedCmd, receivedCmdPar);
610
611 // Setup and start DMA.
612 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
613
614 // And now we loop, receiving samples.
615 for(uint32_t rsamples = 0; TRUE; ) {
616
617 if(BUTTON_PRESS()) {
618 DbpString("cancelled by button");
619 break;
620 }
621
622 LED_A_ON();
623 WDT_HIT();
624
625 int register readBufDataP = data - dmaBuf;
626 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
627 if (readBufDataP <= dmaBufDataP){
628 dataLen = dmaBufDataP - readBufDataP;
629 } else {
630 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
631 }
632 // test for length of buffer
633 if(dataLen > maxDataLen) {
634 maxDataLen = dataLen;
635 if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
636 Dbprintf("blew circular buffer! dataLen=%d", dataLen);
637 break;
638 }
639 }
640 if(dataLen < 1) continue;
641
642 // primary buffer was stopped( <-- we lost data!
643 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
644 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
645 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
646 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
647 }
648 // secondary buffer sets as primary, secondary buffer was stopped
649 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
650 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
651 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
652 }
653
654 LED_A_OFF();
655
656 if (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder
657
658 if(!TagIsActive) { // no need to try decoding reader data if the tag is sending
659 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
660 if (MillerDecoding(readerdata, (rsamples-1)*4)) {
661 LED_C_ON();
662
663 // check - if there is a short 7bit request from reader
664 if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
665
666 if(triggered) {
667 if (!LogTrace(receivedCmd,
668 Uart.len,
669 Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
670 Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
671 Uart.parity,
672 TRUE)) break;
673 }
674 /* And ready to receive another command. */
675 UartReset();
676 /* And also reset the demod code, which might have been */
677 /* false-triggered by the commands from the reader. */
678 DemodReset();
679 LED_B_OFF();
680 }
681 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
682 }
683
684 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time
685 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
686 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
687 LED_B_ON();
688
689 if (!LogTrace(receivedResponse,
690 Demod.len,
691 Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
692 Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
693 Demod.parity,
694 FALSE)) break;
695
696 if ((!triggered) && (param & 0x01)) triggered = TRUE;
697
698 // And ready to receive another response.
699 DemodReset();
700 // And reset the Miller decoder including itS (now outdated) input buffer
701 UartInit(receivedCmd, receivedCmdPar);
702
703 LED_C_OFF();
704 }
705 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
706 }
707 }
708
709 previous_data = *data;
710 rsamples++;
711 data++;
712 if(data == dmaBuf + DMA_BUFFER_SIZE) {
713 data = dmaBuf;
714 }
715 } // main cycle
716
717 DbpString("COMMAND FINISHED");
718
719 FpgaDisableSscDma();
720 Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
721 Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
722 LEDsoff();
723 }
724
725 //-----------------------------------------------------------------------------
726 // Prepare tag messages
727 //-----------------------------------------------------------------------------
728 static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity)
729 {
730 ToSendReset();
731
732 // Correction bit, might be removed when not needed
733 ToSendStuffBit(0);
734 ToSendStuffBit(0);
735 ToSendStuffBit(0);
736 ToSendStuffBit(0);
737 ToSendStuffBit(1); // 1
738 ToSendStuffBit(0);
739 ToSendStuffBit(0);
740 ToSendStuffBit(0);
741
742 // Send startbit
743 ToSend[++ToSendMax] = SEC_D;
744 LastProxToAirDuration = 8 * ToSendMax - 4;
745
746 for(uint16_t i = 0; i < len; i++) {
747 uint8_t b = cmd[i];
748
749 // Data bits
750 for(uint16_t j = 0; j < 8; j++) {
751 if(b & 1) {
752 ToSend[++ToSendMax] = SEC_D;
753 } else {
754 ToSend[++ToSendMax] = SEC_E;
755 }
756 b >>= 1;
757 }
758
759 // Get the parity bit
760 if (parity[i>>3] & (0x80>>(i&0x0007))) {
761 ToSend[++ToSendMax] = SEC_D;
762 LastProxToAirDuration = 8 * ToSendMax - 4;
763 } else {
764 ToSend[++ToSendMax] = SEC_E;
765 LastProxToAirDuration = 8 * ToSendMax;
766 }
767 }
768
769 // Send stopbit
770 ToSend[++ToSendMax] = SEC_F;
771
772 // Convert from last byte pos to length
773 ToSendMax++;
774 }
775
776 static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len)
777 {
778 uint8_t par[MAX_PARITY_SIZE];
779
780 GetParity(cmd, len, par);
781 CodeIso14443aAsTagPar(cmd, len, par);
782 }
783
784
785 static void Code4bitAnswerAsTag(uint8_t cmd)
786 {
787 int i;
788
789 ToSendReset();
790
791 // Correction bit, might be removed when not needed
792 ToSendStuffBit(0);
793 ToSendStuffBit(0);
794 ToSendStuffBit(0);
795 ToSendStuffBit(0);
796 ToSendStuffBit(1); // 1
797 ToSendStuffBit(0);
798 ToSendStuffBit(0);
799 ToSendStuffBit(0);
800
801 // Send startbit
802 ToSend[++ToSendMax] = SEC_D;
803
804 uint8_t b = cmd;
805 for(i = 0; i < 4; i++) {
806 if(b & 1) {
807 ToSend[++ToSendMax] = SEC_D;
808 LastProxToAirDuration = 8 * ToSendMax - 4;
809 } else {
810 ToSend[++ToSendMax] = SEC_E;
811 LastProxToAirDuration = 8 * ToSendMax;
812 }
813 b >>= 1;
814 }
815
816 // Send stopbit
817 ToSend[++ToSendMax] = SEC_F;
818
819 // Convert from last byte pos to length
820 ToSendMax++;
821 }
822
823 //-----------------------------------------------------------------------------
824 // Wait for commands from reader
825 // Stop when button is pressed
826 // Or return TRUE when command is captured
827 //-----------------------------------------------------------------------------
828 static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len)
829 {
830 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
831 // only, since we are receiving, not transmitting).
832 // Signal field is off with the appropriate LED
833 LED_D_OFF();
834 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
835
836 // Now run a `software UART' on the stream of incoming samples.
837 UartInit(received, parity);
838
839 // clear RXRDY:
840 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
841
842 for(;;) {
843 WDT_HIT();
844
845 if(BUTTON_PRESS()) return FALSE;
846
847 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
848 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
849 if(MillerDecoding(b, 0)) {
850 *len = Uart.len;
851 return TRUE;
852 }
853 }
854 }
855 }
856
857 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
858 int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
859 int EmSend4bit(uint8_t resp);
860 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par);
861 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
862 int EmSendCmd(uint8_t *resp, uint16_t respLen);
863 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par);
864 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
865 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity);
866
867 static uint8_t* free_buffer_pointer;
868
869 typedef struct {
870 uint8_t* response;
871 size_t response_n;
872 uint8_t* modulation;
873 size_t modulation_n;
874 uint32_t ProxToAirDuration;
875 } tag_response_info_t;
876
877 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
878 // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
879 // This will need the following byte array for a modulation sequence
880 // 144 data bits (18 * 8)
881 // 18 parity bits
882 // 2 Start and stop
883 // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA)
884 // 1 just for the case
885 // ----------- +
886 // 166 bytes, since every bit that needs to be send costs us a byte
887 //
888
889
890 // Prepare the tag modulation bits from the message
891 CodeIso14443aAsTag(response_info->response,response_info->response_n);
892
893 // Make sure we do not exceed the free buffer space
894 if (ToSendMax > max_buffer_size) {
895 Dbprintf("Out of memory, when modulating bits for tag answer:");
896 Dbhexdump(response_info->response_n,response_info->response,false);
897 return false;
898 }
899
900 // Copy the byte array, used for this modulation to the buffer position
901 memcpy(response_info->modulation,ToSend,ToSendMax);
902
903 // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
904 response_info->modulation_n = ToSendMax;
905 response_info->ProxToAirDuration = LastProxToAirDuration;
906
907 return true;
908 }
909
910
911 // "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit.
912 // Coded responses need one byte per bit to transfer (data, parity, start, stop, correction)
913 // 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits
914 // -> need 273 bytes buffer
915 #define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 273
916
917 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
918 // Retrieve and store the current buffer index
919 response_info->modulation = free_buffer_pointer;
920
921 // Determine the maximum size we can use from our buffer
922 size_t max_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE;
923
924 // Forward the prepare tag modulation function to the inner function
925 if (prepare_tag_modulation(response_info, max_buffer_size)) {
926 // Update the free buffer offset
927 free_buffer_pointer += ToSendMax;
928 return true;
929 } else {
930 return false;
931 }
932 }
933
934 //-----------------------------------------------------------------------------
935 // Main loop of simulated tag: receive commands from reader, decide what
936 // response to send, and send it.
937 //-----------------------------------------------------------------------------
938 void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
939 {
940 uint8_t sak;
941
942 // The first response contains the ATQA (note: bytes are transmitted in reverse order).
943 uint8_t response1[2];
944
945 switch (tagType) {
946 case 1: { // MIFARE Classic
947 // Says: I am Mifare 1k - original line
948 response1[0] = 0x04;
949 response1[1] = 0x00;
950 sak = 0x08;
951 } break;
952 case 2: { // MIFARE Ultralight
953 // Says: I am a stupid memory tag, no crypto
954 response1[0] = 0x04;
955 response1[1] = 0x00;
956 sak = 0x00;
957 } break;
958 case 3: { // MIFARE DESFire
959 // Says: I am a DESFire tag, ph33r me
960 response1[0] = 0x04;
961 response1[1] = 0x03;
962 sak = 0x20;
963 } break;
964 case 4: { // ISO/IEC 14443-4
965 // Says: I am a javacard (JCOP)
966 response1[0] = 0x04;
967 response1[1] = 0x00;
968 sak = 0x28;
969 } break;
970 case 5: { // MIFARE TNP3XXX
971 // Says: I am a toy
972 response1[0] = 0x01;
973 response1[1] = 0x0f;
974 sak = 0x01;
975 } break;
976 default: {
977 Dbprintf("Error: unkown tagtype (%d)",tagType);
978 return;
979 } break;
980 }
981
982 // The second response contains the (mandatory) first 24 bits of the UID
983 uint8_t response2[5] = {0x00};
984
985 // Check if the uid uses the (optional) part
986 uint8_t response2a[5] = {0x00};
987
988 if (uid_2nd) {
989 response2[0] = 0x88;
990 num_to_bytes(uid_1st,3,response2+1);
991 num_to_bytes(uid_2nd,4,response2a);
992 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
993
994 // Configure the ATQA and SAK accordingly
995 response1[0] |= 0x40;
996 sak |= 0x04;
997 } else {
998 num_to_bytes(uid_1st,4,response2);
999 // Configure the ATQA and SAK accordingly
1000 response1[0] &= 0xBF;
1001 sak &= 0xFB;
1002 }
1003
1004 // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
1005 response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
1006
1007 // Prepare the mandatory SAK (for 4 and 7 byte UID)
1008 uint8_t response3[3] = {0x00};
1009 response3[0] = sak;
1010 ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
1011
1012 // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
1013 uint8_t response3a[3] = {0x00};
1014 response3a[0] = sak & 0xFB;
1015 ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
1016
1017 uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
1018 uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS:
1019 // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
1020 // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
1021 // 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)
1022 // TC(1) = 0x02: CID supported, NAD not supported
1023 ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
1024
1025 #define TAG_RESPONSE_COUNT 7
1026 tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
1027 { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type
1028 { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid
1029 { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked
1030 { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1
1031 { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2
1032 { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce)
1033 { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS
1034 };
1035
1036 // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
1037 // Such a response is less time critical, so we can prepare them on the fly
1038 #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
1039 #define DYNAMIC_MODULATION_BUFFER_SIZE 512
1040 uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
1041 uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
1042 tag_response_info_t dynamic_response_info = {
1043 .response = dynamic_response_buffer,
1044 .response_n = 0,
1045 .modulation = dynamic_modulation_buffer,
1046 .modulation_n = 0
1047 };
1048
1049 BigBuf_free_keep_EM();
1050
1051 // allocate buffers:
1052 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
1053 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
1054 free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
1055
1056 // clear trace
1057 clear_trace();
1058 set_tracing(TRUE);
1059
1060 // Prepare the responses of the anticollision phase
1061 // there will be not enough time to do this at the moment the reader sends it REQA
1062 for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
1063 prepare_allocated_tag_modulation(&responses[i]);
1064 }
1065
1066 int len = 0;
1067
1068 // To control where we are in the protocol
1069 int order = 0;
1070 int lastorder;
1071
1072 // Just to allow some checks
1073 int happened = 0;
1074 int happened2 = 0;
1075 int cmdsRecvd = 0;
1076
1077 // We need to listen to the high-frequency, peak-detected path.
1078 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1079
1080 cmdsRecvd = 0;
1081 tag_response_info_t* p_response;
1082
1083 LED_A_ON();
1084 for(;;) {
1085 // Clean receive command buffer
1086
1087 if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
1088 DbpString("Button press");
1089 break;
1090 }
1091
1092 p_response = NULL;
1093
1094 // Okay, look at the command now.
1095 lastorder = order;
1096 if(receivedCmd[0] == 0x26) { // Received a REQUEST
1097 p_response = &responses[0]; order = 1;
1098 } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
1099 p_response = &responses[0]; order = 6;
1100 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // Received request for UID (cascade 1)
1101 p_response = &responses[1]; order = 2;
1102 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2)
1103 p_response = &responses[2]; order = 20;
1104 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) { // Received a SELECT (cascade 1)
1105 p_response = &responses[3]; order = 3;
1106 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) { // Received a SELECT (cascade 2)
1107 p_response = &responses[4]; order = 30;
1108 } else if(receivedCmd[0] == 0x30) { // Received a (plain) READ
1109 EmSendCmdEx(data+(4*receivedCmd[1]),16,false);
1110 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1111 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1112 p_response = NULL;
1113 } else if(receivedCmd[0] == 0x50) { // Received a HALT
1114
1115 if (tracing) {
1116 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1117 }
1118 p_response = NULL;
1119 } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) { // Received an authentication request
1120 p_response = &responses[5]; order = 7;
1121 } else if(receivedCmd[0] == 0xE0) { // Received a RATS request
1122 if (tagType == 1 || tagType == 2) { // RATS not supported
1123 EmSend4bit(CARD_NACK_NA);
1124 p_response = NULL;
1125 } else {
1126 p_response = &responses[6]; order = 70;
1127 }
1128 } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
1129 if (tracing) {
1130 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1131 }
1132 uint32_t nr = bytes_to_num(receivedCmd,4);
1133 uint32_t ar = bytes_to_num(receivedCmd+4,4);
1134 Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar);
1135 } else {
1136 // Check for ISO 14443A-4 compliant commands, look at left nibble
1137 switch (receivedCmd[0]) {
1138
1139 case 0x0B:
1140 case 0x0A: { // IBlock (command)
1141 dynamic_response_info.response[0] = receivedCmd[0];
1142 dynamic_response_info.response[1] = 0x00;
1143 dynamic_response_info.response[2] = 0x90;
1144 dynamic_response_info.response[3] = 0x00;
1145 dynamic_response_info.response_n = 4;
1146 } break;
1147
1148 case 0x1A:
1149 case 0x1B: { // Chaining command
1150 dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1151 dynamic_response_info.response_n = 2;
1152 } break;
1153
1154 case 0xaa:
1155 case 0xbb: {
1156 dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1157 dynamic_response_info.response_n = 2;
1158 } break;
1159
1160 case 0xBA: { //
1161 memcpy(dynamic_response_info.response,"\xAB\x00",2);
1162 dynamic_response_info.response_n = 2;
1163 } break;
1164
1165 case 0xCA:
1166 case 0xC2: { // Readers sends deselect command
1167 memcpy(dynamic_response_info.response,"\xCA\x00",2);
1168 dynamic_response_info.response_n = 2;
1169 } break;
1170
1171 default: {
1172 // Never seen this command before
1173 if (tracing) {
1174 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1175 }
1176 Dbprintf("Received unknown command (len=%d):",len);
1177 Dbhexdump(len,receivedCmd,false);
1178 // Do not respond
1179 dynamic_response_info.response_n = 0;
1180 } break;
1181 }
1182
1183 if (dynamic_response_info.response_n > 0) {
1184 // Copy the CID from the reader query
1185 dynamic_response_info.response[1] = receivedCmd[1];
1186
1187 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1188 AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
1189 dynamic_response_info.response_n += 2;
1190
1191 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1192 Dbprintf("Error preparing tag response");
1193 if (tracing) {
1194 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1195 }
1196 break;
1197 }
1198 p_response = &dynamic_response_info;
1199 }
1200 }
1201
1202 // Count number of wakeups received after a halt
1203 if(order == 6 && lastorder == 5) { happened++; }
1204
1205 // Count number of other messages after a halt
1206 if(order != 6 && lastorder == 5) { happened2++; }
1207
1208 if(cmdsRecvd > 999) {
1209 DbpString("1000 commands later...");
1210 break;
1211 }
1212 cmdsRecvd++;
1213
1214 if (p_response != NULL) {
1215 EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1216 // do the tracing for the previous reader request and this tag answer:
1217 uint8_t par[MAX_PARITY_SIZE];
1218 GetParity(p_response->response, p_response->response_n, par);
1219
1220 EmLogTrace(Uart.output,
1221 Uart.len,
1222 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1223 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1224 Uart.parity,
1225 p_response->response,
1226 p_response->response_n,
1227 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1228 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1229 par);
1230 }
1231
1232 if (!tracing) {
1233 Dbprintf("Trace Full. Simulation stopped.");
1234 break;
1235 }
1236 }
1237
1238 Dbprintf("%x %x %x", happened, happened2, cmdsRecvd);
1239 LED_A_OFF();
1240 BigBuf_free_keep_EM();
1241 }
1242
1243
1244 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1245 // of bits specified in the delay parameter.
1246 void PrepareDelayedTransfer(uint16_t delay)
1247 {
1248 uint8_t bitmask = 0;
1249 uint8_t bits_to_shift = 0;
1250 uint8_t bits_shifted = 0;
1251
1252 delay &= 0x07;
1253 if (delay) {
1254 for (uint16_t i = 0; i < delay; i++) {
1255 bitmask |= (0x01 << i);
1256 }
1257 ToSend[ToSendMax++] = 0x00;
1258 for (uint16_t i = 0; i < ToSendMax; i++) {
1259 bits_to_shift = ToSend[i] & bitmask;
1260 ToSend[i] = ToSend[i] >> delay;
1261 ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1262 bits_shifted = bits_to_shift;
1263 }
1264 }
1265 }
1266
1267
1268 //-------------------------------------------------------------------------------------
1269 // Transmit the command (to the tag) that was placed in ToSend[].
1270 // Parameter timing:
1271 // if NULL: transfer at next possible time, taking into account
1272 // request guard time and frame delay time
1273 // if == 0: transfer immediately and return time of transfer
1274 // if != 0: delay transfer until time specified
1275 //-------------------------------------------------------------------------------------
1276 static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing)
1277 {
1278
1279 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1280
1281 uint32_t ThisTransferTime = 0;
1282
1283 if (timing) {
1284 if(*timing == 0) { // Measure time
1285 *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1286 } else {
1287 PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
1288 }
1289 if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
1290 while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
1291 LastTimeProxToAirStart = *timing;
1292 } else {
1293 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1294 while(GetCountSspClk() < ThisTransferTime);
1295 LastTimeProxToAirStart = ThisTransferTime;
1296 }
1297
1298 // clear TXRDY
1299 AT91C_BASE_SSC->SSC_THR = SEC_Y;
1300
1301 uint16_t c = 0;
1302 for(;;) {
1303 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1304 AT91C_BASE_SSC->SSC_THR = cmd[c];
1305 c++;
1306 if(c >= len) {
1307 break;
1308 }
1309 }
1310 }
1311
1312 NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1313 }
1314
1315
1316 //-----------------------------------------------------------------------------
1317 // Prepare reader command (in bits, support short frames) to send to FPGA
1318 //-----------------------------------------------------------------------------
1319 void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity)
1320 {
1321 int i, j;
1322 int last;
1323 uint8_t b;
1324
1325 ToSendReset();
1326
1327 // Start of Communication (Seq. Z)
1328 ToSend[++ToSendMax] = SEC_Z;
1329 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1330 last = 0;
1331
1332 size_t bytecount = nbytes(bits);
1333 // Generate send structure for the data bits
1334 for (i = 0; i < bytecount; i++) {
1335 // Get the current byte to send
1336 b = cmd[i];
1337 size_t bitsleft = MIN((bits-(i*8)),8);
1338
1339 for (j = 0; j < bitsleft; j++) {
1340 if (b & 1) {
1341 // Sequence X
1342 ToSend[++ToSendMax] = SEC_X;
1343 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1344 last = 1;
1345 } else {
1346 if (last == 0) {
1347 // Sequence Z
1348 ToSend[++ToSendMax] = SEC_Z;
1349 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1350 } else {
1351 // Sequence Y
1352 ToSend[++ToSendMax] = SEC_Y;
1353 last = 0;
1354 }
1355 }
1356 b >>= 1;
1357 }
1358
1359 // Only transmit parity bit if we transmitted a complete byte
1360 if (j == 8 && parity != NULL) {
1361 // Get the parity bit
1362 if (parity[i>>3] & (0x80 >> (i&0x0007))) {
1363 // Sequence X
1364 ToSend[++ToSendMax] = SEC_X;
1365 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1366 last = 1;
1367 } else {
1368 if (last == 0) {
1369 // Sequence Z
1370 ToSend[++ToSendMax] = SEC_Z;
1371 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1372 } else {
1373 // Sequence Y
1374 ToSend[++ToSendMax] = SEC_Y;
1375 last = 0;
1376 }
1377 }
1378 }
1379 }
1380
1381 // End of Communication: Logic 0 followed by Sequence Y
1382 if (last == 0) {
1383 // Sequence Z
1384 ToSend[++ToSendMax] = SEC_Z;
1385 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1386 } else {
1387 // Sequence Y
1388 ToSend[++ToSendMax] = SEC_Y;
1389 last = 0;
1390 }
1391 ToSend[++ToSendMax] = SEC_Y;
1392
1393 // Convert to length of command:
1394 ToSendMax++;
1395 }
1396
1397 //-----------------------------------------------------------------------------
1398 // Prepare reader command to send to FPGA
1399 //-----------------------------------------------------------------------------
1400 void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity)
1401 {
1402 CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
1403 }
1404
1405
1406 //-----------------------------------------------------------------------------
1407 // Wait for commands from reader
1408 // Stop when button is pressed (return 1) or field was gone (return 2)
1409 // Or return 0 when command is captured
1410 //-----------------------------------------------------------------------------
1411 static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity)
1412 {
1413 *len = 0;
1414
1415 uint32_t timer = 0, vtime = 0;
1416 int analogCnt = 0;
1417 int analogAVG = 0;
1418
1419 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1420 // only, since we are receiving, not transmitting).
1421 // Signal field is off with the appropriate LED
1422 LED_D_OFF();
1423 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1424
1425 // Set ADC to read field strength
1426 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1427 AT91C_BASE_ADC->ADC_MR =
1428 ADC_MODE_PRESCALE(63) |
1429 ADC_MODE_STARTUP_TIME(1) |
1430 ADC_MODE_SAMPLE_HOLD_TIME(15);
1431 AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1432 // start ADC
1433 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1434
1435 // Now run a 'software UART' on the stream of incoming samples.
1436 UartInit(received, parity);
1437
1438 // Clear RXRDY:
1439 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1440
1441 for(;;) {
1442 WDT_HIT();
1443
1444 if (BUTTON_PRESS()) return 1;
1445
1446 // test if the field exists
1447 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1448 analogCnt++;
1449 analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1450 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1451 if (analogCnt >= 32) {
1452 if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1453 vtime = GetTickCount();
1454 if (!timer) timer = vtime;
1455 // 50ms no field --> card to idle state
1456 if (vtime - timer > 50) return 2;
1457 } else
1458 if (timer) timer = 0;
1459 analogCnt = 0;
1460 analogAVG = 0;
1461 }
1462 }
1463
1464 // receive and test the miller decoding
1465 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1466 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1467 if(MillerDecoding(b, 0)) {
1468 *len = Uart.len;
1469 return 0;
1470 }
1471 }
1472
1473 }
1474 }
1475
1476
1477 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded)
1478 {
1479 uint8_t b;
1480 uint16_t i = 0;
1481 uint32_t ThisTransferTime;
1482
1483 // Modulate Manchester
1484 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1485
1486 // include correction bit if necessary
1487 if (Uart.parityBits & 0x01) {
1488 correctionNeeded = TRUE;
1489 }
1490 if(correctionNeeded) {
1491 // 1236, so correction bit needed
1492 i = 0;
1493 } else {
1494 i = 1;
1495 }
1496
1497 // clear receiving shift register and holding register
1498 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1499 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1500 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1501 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1502
1503 // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1504 for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never
1505 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1506 if (AT91C_BASE_SSC->SSC_RHR) break;
1507 }
1508
1509 while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1510
1511 // Clear TXRDY:
1512 AT91C_BASE_SSC->SSC_THR = SEC_F;
1513
1514 // send cycle
1515 for(; i < respLen; ) {
1516 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1517 AT91C_BASE_SSC->SSC_THR = resp[i++];
1518 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1519 }
1520
1521 if(BUTTON_PRESS()) {
1522 break;
1523 }
1524 }
1525
1526 // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1527 uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3;
1528 for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
1529 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1530 AT91C_BASE_SSC->SSC_THR = SEC_F;
1531 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1532 i++;
1533 }
1534 }
1535
1536 LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
1537
1538 return 0;
1539 }
1540
1541 int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
1542 Code4bitAnswerAsTag(resp);
1543 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1544 // do the tracing for the previous reader request and this tag answer:
1545 uint8_t par[1];
1546 GetParity(&resp, 1, par);
1547 EmLogTrace(Uart.output,
1548 Uart.len,
1549 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1550 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1551 Uart.parity,
1552 &resp,
1553 1,
1554 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1555 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1556 par);
1557 return res;
1558 }
1559
1560 int EmSend4bit(uint8_t resp){
1561 return EmSend4bitEx(resp, false);
1562 }
1563
1564 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){
1565 CodeIso14443aAsTagPar(resp, respLen, par);
1566 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1567 // do the tracing for the previous reader request and this tag answer:
1568 EmLogTrace(Uart.output,
1569 Uart.len,
1570 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1571 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1572 Uart.parity,
1573 resp,
1574 respLen,
1575 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1576 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1577 par);
1578 return res;
1579 }
1580
1581 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){
1582 uint8_t par[MAX_PARITY_SIZE];
1583 GetParity(resp, respLen, par);
1584 return EmSendCmdExPar(resp, respLen, correctionNeeded, par);
1585 }
1586
1587 int EmSendCmd(uint8_t *resp, uint16_t respLen){
1588 uint8_t par[MAX_PARITY_SIZE];
1589 GetParity(resp, respLen, par);
1590 return EmSendCmdExPar(resp, respLen, false, par);
1591 }
1592
1593 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
1594 return EmSendCmdExPar(resp, respLen, false, par);
1595 }
1596
1597 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
1598 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity)
1599 {
1600 if (tracing) {
1601 // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1602 // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1603 // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1604 uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1605 uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1606 uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1607 reader_EndTime = tag_StartTime - exact_fdt;
1608 reader_StartTime = reader_EndTime - reader_modlen;
1609 if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE)) {
1610 return FALSE;
1611 } else return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
1612 } else {
1613 return TRUE;
1614 }
1615 }
1616
1617 //-----------------------------------------------------------------------------
1618 // Wait a certain time for tag response
1619 // If a response is captured return TRUE
1620 // If it takes too long return FALSE
1621 //-----------------------------------------------------------------------------
1622 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset)
1623 {
1624 uint32_t c = 0x00;
1625
1626 // Set FPGA mode to "reader listen mode", no modulation (listen
1627 // only, since we are receiving, not transmitting).
1628 // Signal field is on with the appropriate LED
1629 LED_D_ON();
1630 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1631
1632 // Now get the answer from the card
1633 DemodInit(receivedResponse, receivedResponsePar);
1634
1635 // clear RXRDY:
1636 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1637
1638 for(;;) {
1639 WDT_HIT();
1640
1641 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1642 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1643 if(ManchesterDecoding(b, offset, 0)) {
1644 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1645 return TRUE;
1646 } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
1647 return FALSE;
1648 }
1649 }
1650 }
1651 }
1652
1653
1654 void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing)
1655 {
1656 CodeIso14443aBitsAsReaderPar(frame, bits, par);
1657
1658 // Send command to tag
1659 TransmitFor14443a(ToSend, ToSendMax, timing);
1660 if(trigger)
1661 LED_A_ON();
1662
1663 // Log reader command in trace buffer
1664 if (tracing) {
1665 LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
1666 }
1667 }
1668
1669
1670 void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing)
1671 {
1672 ReaderTransmitBitsPar(frame, len*8, par, timing);
1673 }
1674
1675
1676 void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing)
1677 {
1678 // Generate parity and redirect
1679 uint8_t par[MAX_PARITY_SIZE];
1680 GetParity(frame, len/8, par);
1681 ReaderTransmitBitsPar(frame, len, par, timing);
1682 }
1683
1684
1685 void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing)
1686 {
1687 // Generate parity and redirect
1688 uint8_t par[MAX_PARITY_SIZE];
1689 GetParity(frame, len, par);
1690 ReaderTransmitBitsPar(frame, len*8, par, timing);
1691 }
1692
1693 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity)
1694 {
1695 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset)) return FALSE;
1696 if (tracing) {
1697 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1698 }
1699 return Demod.len;
1700 }
1701
1702 int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
1703 {
1704 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0)) return FALSE;
1705 if (tracing) {
1706 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1707 }
1708 return Demod.len;
1709 }
1710
1711 /* performs iso14443a anticollision procedure
1712 * fills the uid pointer unless NULL
1713 * fills resp_data unless NULL */
1714 int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr) {
1715 uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP
1716 uint8_t sel_all[] = { 0x93,0x20 };
1717 uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1718 uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1719 uint8_t resp[MAX_FRAME_SIZE]; // theoretically. A usual RATS will be much smaller
1720 uint8_t resp_par[MAX_PARITY_SIZE];
1721 byte_t uid_resp[4];
1722 size_t uid_resp_len;
1723
1724 uint8_t sak = 0x04; // cascade uid
1725 int cascade_level = 0;
1726 int len;
1727
1728 // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1729 ReaderTransmitBitsPar(wupa,7,0, NULL);
1730
1731 // Receive the ATQA
1732 if(!ReaderReceive(resp, resp_par)) return 0;
1733
1734 if(p_hi14a_card) {
1735 memcpy(p_hi14a_card->atqa, resp, 2);
1736 p_hi14a_card->uidlen = 0;
1737 memset(p_hi14a_card->uid,0,10);
1738 }
1739
1740 // clear uid
1741 if (uid_ptr) {
1742 memset(uid_ptr,0,10);
1743 }
1744
1745 // check for proprietary anticollision:
1746 if ((resp[0] & 0x1F) == 0) {
1747 return 3;
1748 }
1749
1750 // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1751 // which case we need to make a cascade 2 request and select - this is a long UID
1752 // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1753 for(; sak & 0x04; cascade_level++) {
1754 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1755 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1756
1757 // SELECT_ALL
1758 ReaderTransmit(sel_all, sizeof(sel_all), NULL);
1759 if (!ReaderReceive(resp, resp_par)) return 0;
1760
1761 if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit
1762 memset(uid_resp, 0, 4);
1763 uint16_t uid_resp_bits = 0;
1764 uint16_t collision_answer_offset = 0;
1765 // anti-collision-loop:
1766 while (Demod.collisionPos) {
1767 Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1768 for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point
1769 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1770 uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8);
1771 }
1772 uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position
1773 uid_resp_bits++;
1774 // construct anticollosion command:
1775 sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits
1776 for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1777 sel_uid[2+i] = uid_resp[i];
1778 }
1779 collision_answer_offset = uid_resp_bits%8;
1780 ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1781 if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0;
1782 }
1783 // finally, add the last bits and BCC of the UID
1784 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1785 uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1786 uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1787 }
1788
1789 } else { // no collision, use the response to SELECT_ALL as current uid
1790 memcpy(uid_resp, resp, 4);
1791 }
1792 uid_resp_len = 4;
1793
1794 // calculate crypto UID. Always use last 4 Bytes.
1795 if(cuid_ptr) {
1796 *cuid_ptr = bytes_to_num(uid_resp, 4);
1797 }
1798
1799 // Construct SELECT UID command
1800 sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1801 memcpy(sel_uid+2, uid_resp, 4); // the UID
1802 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC
1803 AppendCrc14443a(sel_uid, 7); // calculate and add CRC
1804 ReaderTransmit(sel_uid, sizeof(sel_uid), NULL);
1805
1806 // Receive the SAK
1807 if (!ReaderReceive(resp, resp_par)) return 0;
1808 sak = resp[0];
1809
1810 // Test if more parts of the uid are coming
1811 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
1812 // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
1813 // http://www.nxp.com/documents/application_note/AN10927.pdf
1814 uid_resp[0] = uid_resp[1];
1815 uid_resp[1] = uid_resp[2];
1816 uid_resp[2] = uid_resp[3];
1817
1818 uid_resp_len = 3;
1819 }
1820
1821 if(uid_ptr) {
1822 memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
1823 }
1824
1825 if(p_hi14a_card) {
1826 memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
1827 p_hi14a_card->uidlen += uid_resp_len;
1828 }
1829 }
1830
1831 if(p_hi14a_card) {
1832 p_hi14a_card->sak = sak;
1833 p_hi14a_card->ats_len = 0;
1834 }
1835
1836 // non iso14443a compliant tag
1837 if( (sak & 0x20) == 0) return 2;
1838
1839 // Request for answer to select
1840 AppendCrc14443a(rats, 2);
1841 ReaderTransmit(rats, sizeof(rats), NULL);
1842
1843 if (!(len = ReaderReceive(resp, resp_par))) return 0;
1844
1845
1846 if(p_hi14a_card) {
1847 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
1848 p_hi14a_card->ats_len = len;
1849 }
1850
1851 // reset the PCB block number
1852 iso14_pcb_blocknum = 0;
1853
1854 // set default timeout based on ATS
1855 iso14a_set_ATS_timeout(resp);
1856
1857 return 1;
1858 }
1859
1860 void iso14443a_setup(uint8_t fpga_minor_mode) {
1861 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1862 // Set up the synchronous serial port
1863 FpgaSetupSsc();
1864 // connect Demodulated Signal to ADC:
1865 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1866
1867 // Signal field is on with the appropriate LED
1868 if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
1869 || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
1870 LED_D_ON();
1871 } else {
1872 LED_D_OFF();
1873 }
1874 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
1875
1876 // Start the timer
1877 StartCountSspClk();
1878
1879 DemodReset();
1880 UartReset();
1881 NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
1882 iso14a_set_timeout(10*106); // 10ms default
1883 }
1884
1885 int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
1886 uint8_t parity[MAX_PARITY_SIZE];
1887 uint8_t real_cmd[cmd_len+4];
1888 real_cmd[0] = 0x0a; //I-Block
1889 // put block number into the PCB
1890 real_cmd[0] |= iso14_pcb_blocknum;
1891 real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
1892 memcpy(real_cmd+2, cmd, cmd_len);
1893 AppendCrc14443a(real_cmd,cmd_len+2);
1894
1895 ReaderTransmit(real_cmd, cmd_len+4, NULL);
1896 size_t len = ReaderReceive(data, parity);
1897 uint8_t *data_bytes = (uint8_t *) data;
1898 if (!len)
1899 return 0; //DATA LINK ERROR
1900 // if we received an I- or R(ACK)-Block with a block number equal to the
1901 // current block number, toggle the current block number
1902 else if (len >= 4 // PCB+CID+CRC = 4 bytes
1903 && ((data_bytes[0] & 0xC0) == 0 // I-Block
1904 || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
1905 && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
1906 {
1907 iso14_pcb_blocknum ^= 1;
1908 }
1909
1910 return len;
1911 }
1912
1913 //-----------------------------------------------------------------------------
1914 // Read an ISO 14443a tag. Send out commands and store answers.
1915 //
1916 //-----------------------------------------------------------------------------
1917 void ReaderIso14443a(UsbCommand *c)
1918 {
1919 iso14a_command_t param = c->arg[0];
1920 uint8_t *cmd = c->d.asBytes;
1921 size_t len = c->arg[1] & 0xffff;
1922 size_t lenbits = c->arg[1] >> 16;
1923 uint32_t timeout = c->arg[2];
1924 uint32_t arg0 = 0;
1925 byte_t buf[USB_CMD_DATA_SIZE];
1926 uint8_t par[MAX_PARITY_SIZE];
1927
1928 if(param & ISO14A_CONNECT) {
1929 clear_trace();
1930 }
1931
1932 set_tracing(TRUE);
1933
1934 if(param & ISO14A_REQUEST_TRIGGER) {
1935 iso14a_set_trigger(TRUE);
1936 }
1937
1938 if(param & ISO14A_CONNECT) {
1939 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
1940 if(!(param & ISO14A_NO_SELECT)) {
1941 iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
1942 arg0 = iso14443a_select_card(NULL,card,NULL);
1943 cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
1944 }
1945 }
1946
1947 if(param & ISO14A_SET_TIMEOUT) {
1948 iso14a_set_timeout(timeout);
1949 }
1950
1951 if(param & ISO14A_APDU) {
1952 arg0 = iso14_apdu(cmd, len, buf);
1953 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
1954 }
1955
1956 if(param & ISO14A_RAW) {
1957 if(param & ISO14A_APPEND_CRC) {
1958 if(param & ISO14A_TOPAZMODE) {
1959 AppendCrc14443b(cmd,len);
1960 } else {
1961 AppendCrc14443a(cmd,len);
1962 }
1963 len += 2;
1964 if (lenbits) lenbits += 16;
1965 }
1966 if(lenbits>0) { // want to send a specific number of bits (e.g. short commands)
1967 if(param & ISO14A_TOPAZMODE) {
1968 int bits_to_send = lenbits;
1969 uint16_t i = 0;
1970 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL); // first byte is always short (7bits) and no parity
1971 bits_to_send -= 7;
1972 while (bits_to_send > 0) {
1973 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL); // following bytes are 8 bit and no parity
1974 bits_to_send -= 8;
1975 }
1976 } else {
1977 GetParity(cmd, lenbits/8, par);
1978 ReaderTransmitBitsPar(cmd, lenbits, par, NULL); // bytes are 8 bit with odd parity
1979 }
1980 } else { // want to send complete bytes only
1981 if(param & ISO14A_TOPAZMODE) {
1982 uint16_t i = 0;
1983 ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL); // first byte: 7 bits, no paritiy
1984 while (i < len) {
1985 ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL); // following bytes: 8 bits, no paritiy
1986 }
1987 } else {
1988 ReaderTransmit(cmd,len, NULL); // 8 bits, odd parity
1989 }
1990 }
1991 arg0 = ReaderReceive(buf, par);
1992 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
1993 }
1994
1995 if(param & ISO14A_REQUEST_TRIGGER) {
1996 iso14a_set_trigger(FALSE);
1997 }
1998
1999 if(param & ISO14A_NO_DISCONNECT) {
2000 return;
2001 }
2002
2003 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2004 LEDsoff();
2005 }
2006
2007
2008 // Determine the distance between two nonces.
2009 // Assume that the difference is small, but we don't know which is first.
2010 // Therefore try in alternating directions.
2011 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
2012
2013 uint16_t i;
2014 uint32_t nttmp1, nttmp2;
2015
2016 if (nt1 == nt2) return 0;
2017
2018 nttmp1 = nt1;
2019 nttmp2 = nt2;
2020
2021 for (i = 1; i < 32768; i++) {
2022 nttmp1 = prng_successor(nttmp1, 1);
2023 if (nttmp1 == nt2) return i;
2024 nttmp2 = prng_successor(nttmp2, 1);
2025 if (nttmp2 == nt1) return -i;
2026 }
2027
2028 return(-99999); // either nt1 or nt2 are invalid nonces
2029 }
2030
2031
2032 //-----------------------------------------------------------------------------
2033 // Recover several bits of the cypher stream. This implements (first stages of)
2034 // the algorithm described in "The Dark Side of Security by Obscurity and
2035 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
2036 // (article by Nicolas T. Courtois, 2009)
2037 //-----------------------------------------------------------------------------
2038 void ReaderMifare(bool first_try)
2039 {
2040 // Mifare AUTH
2041 uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b };
2042 uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
2043 static uint8_t mf_nr_ar3;
2044
2045 uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE];
2046 uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE];
2047
2048 // free eventually allocated BigBuf memory. We want all for tracing.
2049 BigBuf_free();
2050
2051 clear_trace();
2052 set_tracing(TRUE);
2053
2054 byte_t nt_diff = 0;
2055 uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
2056 static byte_t par_low = 0;
2057 bool led_on = TRUE;
2058 uint8_t uid[10] ={0};
2059 uint32_t cuid;
2060
2061 uint32_t nt = 0;
2062 uint32_t previous_nt = 0;
2063 static uint32_t nt_attacked = 0;
2064 byte_t par_list[8] = {0x00};
2065 byte_t ks_list[8] = {0x00};
2066
2067 static uint32_t sync_time;
2068 static uint32_t sync_cycles;
2069 int catch_up_cycles = 0;
2070 int last_catch_up = 0;
2071 uint16_t consecutive_resyncs = 0;
2072 int isOK = 0;
2073
2074 if (first_try) {
2075 mf_nr_ar3 = 0;
2076 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2077 sync_time = GetCountSspClk() & 0xfffffff8;
2078 sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
2079 nt_attacked = 0;
2080 nt = 0;
2081 par[0] = 0;
2082 }
2083 else {
2084 // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
2085 mf_nr_ar3++;
2086 mf_nr_ar[3] = mf_nr_ar3;
2087 par[0] = par_low;
2088 }
2089
2090 LED_A_ON();
2091 LED_B_OFF();
2092 LED_C_OFF();
2093
2094
2095 for(uint16_t i = 0; TRUE; i++) {
2096
2097 WDT_HIT();
2098
2099 // Test if the action was cancelled
2100 if(BUTTON_PRESS()) {
2101 break;
2102 }
2103
2104 LED_C_ON();
2105
2106 if(!iso14443a_select_card(uid, NULL, &cuid)) {
2107 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
2108 continue;
2109 }
2110
2111 sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
2112 catch_up_cycles = 0;
2113
2114 // if we missed the sync time already, advance to the next nonce repeat
2115 while(GetCountSspClk() > sync_time) {
2116 sync_time = (sync_time & 0xfffffff8) + sync_cycles;
2117 }
2118
2119 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2120 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2121
2122 // Receive the (4 Byte) "random" nonce
2123 if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2124 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce");
2125 continue;
2126 }
2127
2128 previous_nt = nt;
2129 nt = bytes_to_num(receivedAnswer, 4);
2130
2131 // Transmit reader nonce with fake par
2132 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2133
2134 if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
2135 int nt_distance = dist_nt(previous_nt, nt);
2136 if (nt_distance == 0) {
2137 nt_attacked = nt;
2138 }
2139 else {
2140 if (nt_distance == -99999) { // invalid nonce received, try again
2141 continue;
2142 }
2143 sync_cycles = (sync_cycles - nt_distance);
2144 if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
2145 continue;
2146 }
2147 }
2148
2149 if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
2150 catch_up_cycles = -dist_nt(nt_attacked, nt);
2151 if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one.
2152 catch_up_cycles = 0;
2153 continue;
2154 }
2155 if (catch_up_cycles == last_catch_up) {
2156 consecutive_resyncs++;
2157 }
2158 else {
2159 last_catch_up = catch_up_cycles;
2160 consecutive_resyncs = 0;
2161 }
2162 if (consecutive_resyncs < 3) {
2163 if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, -catch_up_cycles, consecutive_resyncs);
2164 }
2165 else {
2166 sync_cycles = sync_cycles + catch_up_cycles;
2167 if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d for the fourth time consecutively (nt_distance = %d). Adjusting sync_cycles to %d.\n", i, -catch_up_cycles, sync_cycles);
2168 }
2169 continue;
2170 }
2171
2172 consecutive_resyncs = 0;
2173
2174 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2175 if (ReaderReceive(receivedAnswer, receivedAnswerPar))
2176 {
2177 catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2178
2179 if (nt_diff == 0)
2180 {
2181 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
2182 }
2183
2184 led_on = !led_on;
2185 if(led_on) LED_B_ON(); else LED_B_OFF();
2186
2187 par_list[nt_diff] = SwapBits(par[0], 8);
2188 ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
2189
2190 // Test if the information is complete
2191 if (nt_diff == 0x07) {
2192 isOK = 1;
2193 break;
2194 }
2195
2196 nt_diff = (nt_diff + 1) & 0x07;
2197 mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2198 par[0] = par_low;
2199 } else {
2200 if (nt_diff == 0 && first_try)
2201 {
2202 par[0]++;
2203 } else {
2204 par[0] = ((par[0] & 0x1F) + 1) | par_low;
2205 }
2206 }
2207 }
2208
2209
2210 mf_nr_ar[3] &= 0x1F;
2211
2212 byte_t buf[28];
2213 memcpy(buf + 0, uid, 4);
2214 num_to_bytes(nt, 4, buf + 4);
2215 memcpy(buf + 8, par_list, 8);
2216 memcpy(buf + 16, ks_list, 8);
2217 memcpy(buf + 24, mf_nr_ar, 4);
2218
2219 cmd_send(CMD_ACK,isOK,0,0,buf,28);
2220
2221 // Thats it...
2222 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2223 LEDsoff();
2224
2225 set_tracing(FALSE);
2226 }
2227
2228 /**
2229 *MIFARE 1K simulate.
2230 *
2231 *@param flags :
2232 * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2233 * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
2234 * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
2235 * FLAG_NR_AR_ATTACK - means we should collect NR_AR responses for bruteforcing later
2236 *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2237 */
2238 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
2239 {
2240 int cardSTATE = MFEMUL_NOFIELD;
2241 int _7BUID = 0;
2242 int vHf = 0; // in mV
2243 int res;
2244 uint32_t selTimer = 0;
2245 uint32_t authTimer = 0;
2246 uint16_t len = 0;
2247 uint8_t cardWRBL = 0;
2248 uint8_t cardAUTHSC = 0;
2249 uint8_t cardAUTHKEY = 0xff; // no authentication
2250 uint32_t cardRr = 0;
2251 uint32_t cuid = 0;
2252 //uint32_t rn_enc = 0;
2253 uint32_t ans = 0;
2254 uint32_t cardINTREG = 0;
2255 uint8_t cardINTBLOCK = 0;
2256 struct Crypto1State mpcs = {0, 0};
2257 struct Crypto1State *pcs;
2258 pcs = &mpcs;
2259 uint32_t numReads = 0;//Counts numer of times reader read a block
2260 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
2261 uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE];
2262 uint8_t response[MAX_MIFARE_FRAME_SIZE];
2263 uint8_t response_par[MAX_MIFARE_PARITY_SIZE];
2264
2265 uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
2266 uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2267 uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
2268 uint8_t rSAK[] = {0x08, 0xb6, 0xdd};
2269 uint8_t rSAK1[] = {0x04, 0xda, 0x17};
2270
2271 uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04};
2272 uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2273
2274 //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
2275 // This can be used in a reader-only attack.
2276 // (it can also be retrieved via 'hf 14a list', but hey...
2277 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
2278 uint8_t ar_nr_collected = 0;
2279
2280 // free eventually allocated BigBuf memory but keep Emulator Memory
2281 BigBuf_free_keep_EM();
2282
2283 // clear trace
2284 clear_trace();
2285 set_tracing(TRUE);
2286
2287 // Authenticate response - nonce
2288 uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2289
2290 //-- Determine the UID
2291 // Can be set from emulator memory, incoming data
2292 // and can be 7 or 4 bytes long
2293 if (flags & FLAG_4B_UID_IN_DATA)
2294 {
2295 // 4B uid comes from data-portion of packet
2296 memcpy(rUIDBCC1,datain,4);
2297 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2298
2299 } else if (flags & FLAG_7B_UID_IN_DATA) {
2300 // 7B uid comes from data-portion of packet
2301 memcpy(&rUIDBCC1[1],datain,3);
2302 memcpy(rUIDBCC2, datain+3, 4);
2303 _7BUID = true;
2304 } else {
2305 // get UID from emul memory
2306 emlGetMemBt(receivedCmd, 7, 1);
2307 _7BUID = !(receivedCmd[0] == 0x00);
2308 if (!_7BUID) { // ---------- 4BUID
2309 emlGetMemBt(rUIDBCC1, 0, 4);
2310 } else { // ---------- 7BUID
2311 emlGetMemBt(&rUIDBCC1[1], 0, 3);
2312 emlGetMemBt(rUIDBCC2, 3, 4);
2313 }
2314 }
2315
2316 /*
2317 * Regardless of what method was used to set the UID, set fifth byte and modify
2318 * the ATQA for 4 or 7-byte UID
2319 */
2320 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2321 if (_7BUID) {
2322 rATQA[0] = 0x44;
2323 rUIDBCC1[0] = 0x88;
2324 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2325 }
2326
2327 // We need to listen to the high-frequency, peak-detected path.
2328 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2329
2330
2331 if (MF_DBGLEVEL >= 1) {
2332 if (!_7BUID) {
2333 Dbprintf("4B UID: %02x%02x%02x%02x",
2334 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3]);
2335 } else {
2336 Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",
2337 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3],
2338 rUIDBCC2[0], rUIDBCC2[1] ,rUIDBCC2[2], rUIDBCC2[3]);
2339 }
2340 }
2341
2342 bool finished = FALSE;
2343 while (!BUTTON_PRESS() && !finished) {
2344 WDT_HIT();
2345
2346 // find reader field
2347 if (cardSTATE == MFEMUL_NOFIELD) {
2348 vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
2349 if (vHf > MF_MINFIELDV) {
2350 cardSTATE_TO_IDLE();
2351 LED_A_ON();
2352 }
2353 }
2354 if(cardSTATE == MFEMUL_NOFIELD) continue;
2355
2356 //Now, get data
2357
2358 res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
2359 if (res == 2) { //Field is off!
2360 cardSTATE = MFEMUL_NOFIELD;
2361 LEDsoff();
2362 continue;
2363 } else if (res == 1) {
2364 break; //return value 1 means button press
2365 }
2366
2367 // REQ or WUP request in ANY state and WUP in HALTED state
2368 if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
2369 selTimer = GetTickCount();
2370 EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
2371 cardSTATE = MFEMUL_SELECT1;
2372
2373 // init crypto block
2374 LED_B_OFF();
2375 LED_C_OFF();
2376 crypto1_destroy(pcs);
2377 cardAUTHKEY = 0xff;
2378 continue;
2379 }
2380
2381 switch (cardSTATE) {
2382 case MFEMUL_NOFIELD:
2383 case MFEMUL_HALTED:
2384 case MFEMUL_IDLE:{
2385 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2386 break;
2387 }
2388 case MFEMUL_SELECT1:{
2389 // select all
2390 if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
2391 if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received");
2392 EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2393 break;
2394 }
2395
2396 if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
2397 {
2398 Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
2399 }
2400 // select card
2401 if (len == 9 &&
2402 (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2403 EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK));
2404 cuid = bytes_to_num(rUIDBCC1, 4);
2405 if (!_7BUID) {
2406 cardSTATE = MFEMUL_WORK;
2407 LED_B_ON();
2408 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2409 break;
2410 } else {
2411 cardSTATE = MFEMUL_SELECT2;
2412 }
2413 }
2414 break;
2415 }
2416 case MFEMUL_AUTH1:{
2417 if( len != 8)
2418 {
2419 cardSTATE_TO_IDLE();
2420 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2421 break;
2422 }
2423
2424 uint32_t ar = bytes_to_num(receivedCmd, 4);
2425 uint32_t nr = bytes_to_num(&receivedCmd[4], 4);
2426
2427 //Collect AR/NR
2428 if(ar_nr_collected < 2 && cardAUTHSC == 2){
2429 if(ar_nr_responses[2] != ar)
2430 {// Avoid duplicates... probably not necessary, ar should vary.
2431 ar_nr_responses[ar_nr_collected*4] = cuid;
2432 ar_nr_responses[ar_nr_collected*4+1] = nonce;
2433 ar_nr_responses[ar_nr_collected*4+2] = ar;
2434 ar_nr_responses[ar_nr_collected*4+3] = nr;
2435 ar_nr_collected++;
2436 }
2437 // Interactive mode flag, means we need to send ACK
2438 if(flags & FLAG_INTERACTIVE && ar_nr_collected == 2)
2439 {
2440 finished = true;
2441 }
2442 }
2443
2444 // --- crypto
2445 crypto1_word(pcs, ar , 1);
2446 cardRr = nr ^ crypto1_word(pcs, 0, 0);
2447
2448 // test if auth OK
2449 if (cardRr != prng_successor(nonce, 64)){
2450 if (MF_DBGLEVEL >= 2) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
2451 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2452 cardRr, prng_successor(nonce, 64));
2453 // Shouldn't we respond anything here?
2454 // Right now, we don't nack or anything, which causes the
2455 // reader to do a WUPA after a while. /Martin
2456 // -- which is the correct response. /piwi
2457 cardSTATE_TO_IDLE();
2458 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2459 break;
2460 }
2461
2462 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2463
2464 num_to_bytes(ans, 4, rAUTH_AT);
2465 // --- crypto
2466 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2467 LED_C_ON();
2468 cardSTATE = MFEMUL_WORK;
2469 if (MF_DBGLEVEL >= 4) Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2470 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2471 GetTickCount() - authTimer);
2472 break;
2473 }
2474 case MFEMUL_SELECT2:{
2475 if (!len) {
2476 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2477 break;
2478 }
2479 if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
2480 EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2481 break;
2482 }
2483
2484 // select 2 card
2485 if (len == 9 &&
2486 (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
2487 EmSendCmd(rSAK, sizeof(rSAK));
2488 cuid = bytes_to_num(rUIDBCC2, 4);
2489 cardSTATE = MFEMUL_WORK;
2490 LED_B_ON();
2491 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2492 break;
2493 }
2494
2495 // i guess there is a command). go into the work state.
2496 if (len != 4) {
2497 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2498 break;
2499 }
2500 cardSTATE = MFEMUL_WORK;
2501 //goto lbWORK;
2502 //intentional fall-through to the next case-stmt
2503 }
2504
2505 case MFEMUL_WORK:{
2506 if (len == 0) {
2507 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2508 break;
2509 }
2510
2511 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2512
2513 if(encrypted_data) {
2514 // decrypt seqence
2515 mf_crypto1_decrypt(pcs, receivedCmd, len);
2516 }
2517
2518 if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
2519 authTimer = GetTickCount();
2520 cardAUTHSC = receivedCmd[1] / 4; // received block num
2521 cardAUTHKEY = receivedCmd[0] - 0x60;
2522 crypto1_destroy(pcs);//Added by martin
2523 crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2524
2525 if (!encrypted_data) { // first authentication
2526 if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2527
2528 crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
2529 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2530 } else { // nested authentication
2531 if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2532 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2533 num_to_bytes(ans, 4, rAUTH_AT);
2534 }
2535
2536 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2537 //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
2538 cardSTATE = MFEMUL_AUTH1;
2539 break;
2540 }
2541
2542 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2543 // BUT... ACK --> NACK
2544 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2545 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2546 break;
2547 }
2548
2549 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2550 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2551 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2552 break;
2553 }
2554
2555 if(len != 4) {
2556 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2557 break;
2558 }
2559
2560 if(receivedCmd[0] == 0x30 // read block
2561 || receivedCmd[0] == 0xA0 // write block
2562 || receivedCmd[0] == 0xC0 // inc
2563 || receivedCmd[0] == 0xC1 // dec
2564 || receivedCmd[0] == 0xC2 // restore
2565 || receivedCmd[0] == 0xB0) { // transfer
2566 if (receivedCmd[1] >= 16 * 4) {
2567 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2568 if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2569 break;
2570 }
2571
2572 if (receivedCmd[1] / 4 != cardAUTHSC) {
2573 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2574 if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
2575 break;
2576 }
2577 }
2578 // read block
2579 if (receivedCmd[0] == 0x30) {
2580 if (MF_DBGLEVEL >= 4) {
2581 Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
2582 }
2583 emlGetMem(response, receivedCmd[1], 1);
2584 AppendCrc14443a(response, 16);
2585 mf_crypto1_encrypt(pcs, response, 18, response_par);
2586 EmSendCmdPar(response, 18, response_par);
2587 numReads++;
2588 if(exitAfterNReads > 0 && numReads >= exitAfterNReads) {
2589 Dbprintf("%d reads done, exiting", numReads);
2590 finished = true;
2591 }
2592 break;
2593 }
2594 // write block
2595 if (receivedCmd[0] == 0xA0) {
2596 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
2597 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2598 cardSTATE = MFEMUL_WRITEBL2;
2599 cardWRBL = receivedCmd[1];
2600 break;
2601 }
2602 // increment, decrement, restore
2603 if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
2604 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2605 if (emlCheckValBl(receivedCmd[1])) {
2606 if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2607 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2608 break;
2609 }
2610 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2611 if (receivedCmd[0] == 0xC1)
2612 cardSTATE = MFEMUL_INTREG_INC;
2613 if (receivedCmd[0] == 0xC0)
2614 cardSTATE = MFEMUL_INTREG_DEC;
2615 if (receivedCmd[0] == 0xC2)
2616 cardSTATE = MFEMUL_INTREG_REST;
2617 cardWRBL = receivedCmd[1];
2618 break;
2619 }
2620 // transfer
2621 if (receivedCmd[0] == 0xB0) {
2622 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2623 if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2624 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2625 else
2626 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2627 break;
2628 }
2629 // halt
2630 if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
2631 LED_B_OFF();
2632 LED_C_OFF();
2633 cardSTATE = MFEMUL_HALTED;
2634 if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer);
2635 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2636 break;
2637 }
2638 // RATS
2639 if (receivedCmd[0] == 0xe0) {//RATS
2640 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2641 break;
2642 }
2643 // command not allowed
2644 if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking");
2645 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2646 break;
2647 }
2648 case MFEMUL_WRITEBL2:{
2649 if (len == 18){
2650 mf_crypto1_decrypt(pcs, receivedCmd, len);
2651 emlSetMem(receivedCmd, cardWRBL, 1);
2652 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2653 cardSTATE = MFEMUL_WORK;
2654 } else {
2655 cardSTATE_TO_IDLE();
2656 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2657 }
2658 break;
2659 }
2660
2661 case MFEMUL_INTREG_INC:{
2662 mf_crypto1_decrypt(pcs, receivedCmd, len);
2663 memcpy(&ans, receivedCmd, 4);
2664 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2665 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2666 cardSTATE_TO_IDLE();
2667 break;
2668 }
2669 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2670 cardINTREG = cardINTREG + ans;
2671 cardSTATE = MFEMUL_WORK;
2672 break;
2673 }
2674 case MFEMUL_INTREG_DEC:{
2675 mf_crypto1_decrypt(pcs, receivedCmd, len);
2676 memcpy(&ans, receivedCmd, 4);
2677 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2678 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2679 cardSTATE_TO_IDLE();
2680 break;
2681 }
2682 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2683 cardINTREG = cardINTREG - ans;
2684 cardSTATE = MFEMUL_WORK;
2685 break;
2686 }
2687 case MFEMUL_INTREG_REST:{
2688 mf_crypto1_decrypt(pcs, receivedCmd, len);
2689 memcpy(&ans, receivedCmd, 4);
2690 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2691 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2692 cardSTATE_TO_IDLE();
2693 break;
2694 }
2695 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2696 cardSTATE = MFEMUL_WORK;
2697 break;
2698 }
2699 }
2700 }
2701
2702 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2703 LEDsoff();
2704
2705 if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
2706 {
2707 //May just aswell send the collected ar_nr in the response aswell
2708 cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,1,0,&ar_nr_responses,ar_nr_collected*4*4);
2709 }
2710
2711 if(flags & FLAG_NR_AR_ATTACK && MF_DBGLEVEL >= 1 )
2712 {
2713 if(ar_nr_collected > 1 ) {
2714 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
2715 Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
2716 ar_nr_responses[0], // UID
2717 ar_nr_responses[1], //NT
2718 ar_nr_responses[2], //AR1
2719 ar_nr_responses[3], //NR1
2720 ar_nr_responses[6], //AR2
2721 ar_nr_responses[7] //NR2
2722 );
2723 } else {
2724 Dbprintf("Failed to obtain two AR/NR pairs!");
2725 if(ar_nr_collected > 0 ) {
2726 Dbprintf("Only got these: UID=%08x, nonce=%08x, AR1=%08x, NR1=%08x",
2727 ar_nr_responses[0], // UID
2728 ar_nr_responses[1], //NT
2729 ar_nr_responses[2], //AR1
2730 ar_nr_responses[3] //NR1
2731 );
2732 }
2733 }
2734 }
2735 if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen());
2736
2737 }
2738
2739
2740
2741 //-----------------------------------------------------------------------------
2742 // MIFARE sniffer.
2743 //
2744 //-----------------------------------------------------------------------------
2745 void RAMFUNC SniffMifare(uint8_t param) {
2746 // param:
2747 // bit 0 - trigger from first card answer
2748 // bit 1 - trigger from first reader 7-bit request
2749
2750 // C(red) A(yellow) B(green)
2751 LEDsoff();
2752 // init trace buffer
2753 clear_trace();
2754 set_tracing(TRUE);
2755
2756 // The command (reader -> tag) that we're receiving.
2757 // The length of a received command will in most cases be no more than 18 bytes.
2758 // So 32 should be enough!
2759 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
2760 uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE];
2761 // The response (tag -> reader) that we're receiving.
2762 uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE];
2763 uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE];
2764
2765 // As we receive stuff, we copy it from receivedCmd or receivedResponse
2766 // into trace, along with its length and other annotations.
2767 //uint8_t *trace = (uint8_t *)BigBuf;
2768
2769 // free eventually allocated BigBuf memory
2770 BigBuf_free();
2771 // allocate the DMA buffer, used to stream samples from the FPGA
2772 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
2773 uint8_t *data = dmaBuf;
2774 uint8_t previous_data = 0;
2775 int maxDataLen = 0;
2776 int dataLen = 0;
2777 bool ReaderIsActive = FALSE;
2778 bool TagIsActive = FALSE;
2779
2780 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
2781
2782 // Set up the demodulator for tag -> reader responses.
2783 DemodInit(receivedResponse, receivedResponsePar);
2784
2785 // Set up the demodulator for the reader -> tag commands
2786 UartInit(receivedCmd, receivedCmdPar);
2787
2788 // Setup for the DMA.
2789 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2790
2791 LED_D_OFF();
2792
2793 // init sniffer
2794 MfSniffInit();
2795
2796 // And now we loop, receiving samples.
2797 for(uint32_t sniffCounter = 0; TRUE; ) {
2798
2799 if(BUTTON_PRESS()) {
2800 DbpString("cancelled by button");
2801 break;
2802 }
2803
2804 LED_A_ON();
2805 WDT_HIT();
2806
2807 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
2808 // check if a transaction is completed (timeout after 2000ms).
2809 // if yes, stop the DMA transfer and send what we have so far to the client
2810 if (MfSniffSend(2000)) {
2811 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
2812 sniffCounter = 0;
2813 data = dmaBuf;
2814 maxDataLen = 0;
2815 ReaderIsActive = FALSE;
2816 TagIsActive = FALSE;
2817 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2818 }
2819 }
2820
2821 int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
2822 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
2823 if (readBufDataP <= dmaBufDataP){ // we are processing the same block of data which is currently being transferred
2824 dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
2825 } else {
2826 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
2827 }
2828 // test for length of buffer
2829 if(dataLen > maxDataLen) { // we are more behind than ever...
2830 maxDataLen = dataLen;
2831 if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
2832 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
2833 break;
2834 }
2835 }
2836 if(dataLen < 1) continue;
2837
2838 // primary buffer was stopped ( <-- we lost data!
2839 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
2840 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
2841 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
2842 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
2843 }
2844 // secondary buffer sets as primary, secondary buffer was stopped
2845 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
2846 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
2847 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
2848 }
2849
2850 LED_A_OFF();
2851
2852 if (sniffCounter & 0x01) {
2853
2854 if(!TagIsActive) { // no need to try decoding tag data if the reader is sending
2855 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
2856 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
2857 LED_C_INV();
2858 if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
2859
2860 /* And ready to receive another command. */
2861 UartInit(receivedCmd, receivedCmdPar);
2862
2863 /* And also reset the demod code */
2864 DemodReset();
2865 }
2866 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
2867 }
2868
2869 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending
2870 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
2871 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
2872 LED_C_INV();
2873
2874 if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
2875
2876 // And ready to receive another response.
2877 DemodReset();
2878
2879 // And reset the Miller decoder including its (now outdated) input buffer
2880 UartInit(receivedCmd, receivedCmdPar);
2881 }
2882 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
2883 }
2884 }
2885
2886 previous_data = *data;
2887 sniffCounter++;
2888 data++;
2889 if(data == dmaBuf + DMA_BUFFER_SIZE) {
2890 data = dmaBuf;
2891 }
2892
2893 } // main cycle
2894
2895 DbpString("COMMAND FINISHED");
2896
2897 FpgaDisableSscDma();
2898 MfSniffEnd();
2899
2900 Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
2901 LEDsoff();
2902 }
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