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1 //-----------------------------------------------------------------------------
2 // Merlok - June 2011, 2012
3 // Gerhard de Koning Gans - May 2008
4 // Hagen Fritsch - June 2010
5 //
6 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
7 // at your option, any later version. See the LICENSE.txt file for the text of
8 // the license.
9 //-----------------------------------------------------------------------------
10 // Routines to support ISO 14443 type A.
11 //-----------------------------------------------------------------------------
12
13 #include "proxmark3.h"
14 #include "apps.h"
15 #include "util.h"
16 #include "string.h"
17 #include "cmd.h"
18 #include "iso14443crc.h"
19 #include "iso14443a.h"
20 #include "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 SniffIso14443a(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 //UartInit(receivedCmd, receivedCmdPar);
677 /* And also reset the demod code, which might have been */
678 /* false-triggered by the commands from the reader. */
679 DemodReset();
680 LED_B_OFF();
681 }
682 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
683 }
684
685 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time
686 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
687 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
688 LED_B_ON();
689
690 if (!LogTrace(receivedResponse,
691 Demod.len,
692 Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
693 Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
694 Demod.parity,
695 FALSE)) break;
696
697 if ((!triggered) && (param & 0x01)) triggered = TRUE;
698
699 // And ready to receive another response.
700 DemodReset();
701 // And reset the Miller decoder including itS (now outdated) input buffer
702 UartInit(receivedCmd, receivedCmdPar);
703
704 LED_C_OFF();
705 }
706 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
707 }
708 }
709
710 previous_data = *data;
711 rsamples++;
712 data++;
713 if(data == dmaBuf + DMA_BUFFER_SIZE) {
714 data = dmaBuf;
715 }
716 } // main cycle
717
718 DbpString("COMMAND FINISHED");
719
720 FpgaDisableSscDma();
721 Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
722 Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
723 LEDsoff();
724 }
725
726 //-----------------------------------------------------------------------------
727 // Prepare tag messages
728 //-----------------------------------------------------------------------------
729 static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity)
730 {
731 ToSendReset();
732
733 // Correction bit, might be removed when not needed
734 ToSendStuffBit(0);
735 ToSendStuffBit(0);
736 ToSendStuffBit(0);
737 ToSendStuffBit(0);
738 ToSendStuffBit(1); // 1
739 ToSendStuffBit(0);
740 ToSendStuffBit(0);
741 ToSendStuffBit(0);
742
743 // Send startbit
744 ToSend[++ToSendMax] = SEC_D;
745 LastProxToAirDuration = 8 * ToSendMax - 4;
746
747 for(uint16_t i = 0; i < len; i++) {
748 uint8_t b = cmd[i];
749
750 // Data bits
751 for(uint16_t j = 0; j < 8; j++) {
752 if(b & 1) {
753 ToSend[++ToSendMax] = SEC_D;
754 } else {
755 ToSend[++ToSendMax] = SEC_E;
756 }
757 b >>= 1;
758 }
759
760 // Get the parity bit
761 if (parity[i>>3] & (0x80>>(i&0x0007))) {
762 ToSend[++ToSendMax] = SEC_D;
763 LastProxToAirDuration = 8 * ToSendMax - 4;
764 } else {
765 ToSend[++ToSendMax] = SEC_E;
766 LastProxToAirDuration = 8 * ToSendMax;
767 }
768 }
769
770 // Send stopbit
771 ToSend[++ToSendMax] = SEC_F;
772
773 // Convert from last byte pos to length
774 ToSendMax++;
775 }
776
777 static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len)
778 {
779 uint8_t par[MAX_PARITY_SIZE];
780
781 GetParity(cmd, len, par);
782 CodeIso14443aAsTagPar(cmd, len, par);
783 }
784
785
786 static void Code4bitAnswerAsTag(uint8_t cmd)
787 {
788 int i;
789
790 ToSendReset();
791
792 // Correction bit, might be removed when not needed
793 ToSendStuffBit(0);
794 ToSendStuffBit(0);
795 ToSendStuffBit(0);
796 ToSendStuffBit(0);
797 ToSendStuffBit(1); // 1
798 ToSendStuffBit(0);
799 ToSendStuffBit(0);
800 ToSendStuffBit(0);
801
802 // Send startbit
803 ToSend[++ToSendMax] = SEC_D;
804
805 uint8_t b = cmd;
806 for(i = 0; i < 4; i++) {
807 if(b & 1) {
808 ToSend[++ToSendMax] = SEC_D;
809 LastProxToAirDuration = 8 * ToSendMax - 4;
810 } else {
811 ToSend[++ToSendMax] = SEC_E;
812 LastProxToAirDuration = 8 * ToSendMax;
813 }
814 b >>= 1;
815 }
816
817 // Send stopbit
818 ToSend[++ToSendMax] = SEC_F;
819
820 // Convert from last byte pos to length
821 ToSendMax++;
822 }
823
824 //-----------------------------------------------------------------------------
825 // Wait for commands from reader
826 // Stop when button is pressed
827 // Or return TRUE when command is captured
828 //-----------------------------------------------------------------------------
829 static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len)
830 {
831 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
832 // only, since we are receiving, not transmitting).
833 // Signal field is off with the appropriate LED
834 LED_D_OFF();
835 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
836
837 // Now run a `software UART' on the stream of incoming samples.
838 UartInit(received, parity);
839
840 // clear RXRDY:
841 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
842
843 for(;;) {
844 WDT_HIT();
845
846 if(BUTTON_PRESS()) return FALSE;
847
848 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
849 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
850 if(MillerDecoding(b, 0)) {
851 *len = Uart.len;
852 return TRUE;
853 }
854 }
855 }
856 }
857
858 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
859 int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
860 int EmSend4bit(uint8_t resp);
861 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par);
862 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
863 int EmSendCmd(uint8_t *resp, uint16_t respLen);
864 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par);
865 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
866 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity);
867
868 static uint8_t* free_buffer_pointer;
869
870 typedef struct {
871 uint8_t* response;
872 size_t response_n;
873 uint8_t* modulation;
874 size_t modulation_n;
875 uint32_t ProxToAirDuration;
876 } tag_response_info_t;
877
878 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
879 // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
880 // This will need the following byte array for a modulation sequence
881 // 144 data bits (18 * 8)
882 // 18 parity bits
883 // 2 Start and stop
884 // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA)
885 // 1 just for the case
886 // ----------- +
887 // 166 bytes, since every bit that needs to be send costs us a byte
888 //
889
890
891 // Prepare the tag modulation bits from the message
892 CodeIso14443aAsTag(response_info->response,response_info->response_n);
893
894 // Make sure we do not exceed the free buffer space
895 if (ToSendMax > max_buffer_size) {
896 Dbprintf("Out of memory, when modulating bits for tag answer:");
897 Dbhexdump(response_info->response_n,response_info->response,false);
898 return false;
899 }
900
901 // Copy the byte array, used for this modulation to the buffer position
902 memcpy(response_info->modulation,ToSend,ToSendMax);
903
904 // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
905 response_info->modulation_n = ToSendMax;
906 response_info->ProxToAirDuration = LastProxToAirDuration;
907
908 return true;
909 }
910
911
912 // "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit.
913 // Coded responses need one byte per bit to transfer (data, parity, start, stop, correction)
914 // 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits
915 // -> need 273 bytes buffer
916 #define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 273
917
918 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
919 // Retrieve and store the current buffer index
920 response_info->modulation = free_buffer_pointer;
921
922 // Determine the maximum size we can use from our buffer
923 size_t max_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE;
924
925 // Forward the prepare tag modulation function to the inner function
926 if (prepare_tag_modulation(response_info, max_buffer_size)) {
927 // Update the free buffer offset
928 free_buffer_pointer += ToSendMax;
929 return true;
930 } else {
931 return false;
932 }
933 }
934
935 //-----------------------------------------------------------------------------
936 // Main loop of simulated tag: receive commands from reader, decide what
937 // response to send, and send it.
938 //-----------------------------------------------------------------------------
939 void SimulateIso14443aTag(int tagType, int flags, int uid_2nd, byte_t* data)
940 {
941
942 //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
943 // This can be used in a reader-only attack.
944 // (it can also be retrieved via 'hf 14a list', but hey...
945 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0,0,0};
946 uint8_t ar_nr_collected = 0;
947
948 uint8_t sak;
949
950 // The first response contains the ATQA (note: bytes are transmitted in reverse order).
951 uint8_t response1[2];
952
953 switch (tagType) {
954 case 1: { // MIFARE Classic
955 // Says: I am Mifare 1k - original line
956 response1[0] = 0x04;
957 response1[1] = 0x00;
958 sak = 0x08;
959 } break;
960 case 2: { // MIFARE Ultralight
961 // Says: I am a stupid memory tag, no crypto
962 response1[0] = 0x04;
963 response1[1] = 0x00;
964 sak = 0x00;
965 } break;
966 case 3: { // MIFARE DESFire
967 // Says: I am a DESFire tag, ph33r me
968 response1[0] = 0x04;
969 response1[1] = 0x03;
970 sak = 0x20;
971 } break;
972 case 4: { // ISO/IEC 14443-4
973 // Says: I am a javacard (JCOP)
974 response1[0] = 0x04;
975 response1[1] = 0x00;
976 sak = 0x28;
977 } break;
978 case 5: { // MIFARE TNP3XXX
979 // Says: I am a toy
980 response1[0] = 0x01;
981 response1[1] = 0x0f;
982 sak = 0x01;
983 } break;
984 case 6: { // MIFARE Mini
985 // Says: I am a Mifare Mini, 320b
986 response1[0] = 0x44;
987 response1[1] = 0x00;
988 sak = 0x09;
989 } break;
990 default: {
991 Dbprintf("Error: unkown tagtype (%d)",tagType);
992 return;
993 } break;
994 }
995
996 // The second response contains the (mandatory) first 24 bits of the UID
997 uint8_t response2[5] = {0x00};
998
999 // Check if the uid uses the (optional) part
1000 uint8_t response2a[5] = {0x00};
1001
1002 if (flags & FLAG_7B_UID_IN_DATA) {
1003 response2[0] = 0x88;
1004 response2[1] = data[0];
1005 response2[2] = data[1];
1006 response2[3] = data[2];
1007
1008 response2a[0] = data[3];
1009 response2a[1] = data[4];
1010 response2a[2] = data[5];
1011 response2a[3] = data[6]; //??
1012 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
1013
1014 // Configure the ATQA and SAK accordingly
1015 response1[0] |= 0x40;
1016 sak |= 0x04;
1017 } else {
1018 memcpy(response2, data, 4);
1019 //num_to_bytes(uid_1st,4,response2);
1020 // Configure the ATQA and SAK accordingly
1021 response1[0] &= 0xBF;
1022 sak &= 0xFB;
1023 }
1024
1025 // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
1026 response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
1027
1028 // Prepare the mandatory SAK (for 4 and 7 byte UID)
1029 uint8_t response3[3] = {0x00};
1030 response3[0] = sak;
1031 ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
1032
1033 // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
1034 uint8_t response3a[3] = {0x00};
1035 response3a[0] = sak & 0xFB;
1036 ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
1037
1038 uint8_t response5[] = { 0x01, 0x01, 0x01, 0x01 }; // Very random tag nonce
1039 uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS:
1040 // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
1041 // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
1042 // 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)
1043 // TC(1) = 0x02: CID supported, NAD not supported
1044 ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
1045
1046 #define TAG_RESPONSE_COUNT 7
1047 tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
1048 { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type
1049 { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid
1050 { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked
1051 { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1
1052 { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2
1053 { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce)
1054 { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS
1055 };
1056
1057 // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
1058 // Such a response is less time critical, so we can prepare them on the fly
1059 #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
1060 #define DYNAMIC_MODULATION_BUFFER_SIZE 512
1061 uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
1062 uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
1063 tag_response_info_t dynamic_response_info = {
1064 .response = dynamic_response_buffer,
1065 .response_n = 0,
1066 .modulation = dynamic_modulation_buffer,
1067 .modulation_n = 0
1068 };
1069
1070 BigBuf_free_keep_EM();
1071
1072 // allocate buffers:
1073 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
1074 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
1075 free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
1076
1077 // clear trace
1078 clear_trace();
1079 set_tracing(TRUE);
1080
1081 // Prepare the responses of the anticollision phase
1082 // there will be not enough time to do this at the moment the reader sends it REQA
1083 for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
1084 prepare_allocated_tag_modulation(&responses[i]);
1085 }
1086
1087 int len = 0;
1088
1089 // To control where we are in the protocol
1090 int order = 0;
1091 int lastorder;
1092
1093 // Just to allow some checks
1094 int happened = 0;
1095 int happened2 = 0;
1096 int cmdsRecvd = 0;
1097
1098 // We need to listen to the high-frequency, peak-detected path.
1099 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1100
1101 cmdsRecvd = 0;
1102 tag_response_info_t* p_response;
1103
1104 LED_A_ON();
1105 for(;;) {
1106 // Clean receive command buffer
1107
1108 if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
1109 DbpString("Button press");
1110 break;
1111 }
1112
1113 p_response = NULL;
1114
1115 // Okay, look at the command now.
1116 lastorder = order;
1117 if(receivedCmd[0] == 0x26) { // Received a REQUEST
1118 p_response = &responses[0]; order = 1;
1119 } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
1120 p_response = &responses[0]; order = 6;
1121 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // Received request for UID (cascade 1)
1122 p_response = &responses[1]; order = 2;
1123 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2)
1124 p_response = &responses[2]; order = 20;
1125 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) { // Received a SELECT (cascade 1)
1126 p_response = &responses[3]; order = 3;
1127 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) { // Received a SELECT (cascade 2)
1128 p_response = &responses[4]; order = 30;
1129 } else if(receivedCmd[0] == 0x30) { // Received a (plain) READ
1130 EmSendCmdEx(data+(4*receivedCmd[1]),16,false);
1131 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1132 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1133 p_response = NULL;
1134 } else if(receivedCmd[0] == 0x50) { // Received a HALT
1135
1136 if (tracing) {
1137 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1138 }
1139 p_response = NULL;
1140 } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) { // Received an authentication request
1141 p_response = &responses[5]; order = 7;
1142 } else if(receivedCmd[0] == 0xE0) { // Received a RATS request
1143 if (tagType == 1 || tagType == 2) { // RATS not supported
1144 EmSend4bit(CARD_NACK_NA);
1145 p_response = NULL;
1146 } else {
1147 p_response = &responses[6]; order = 70;
1148 }
1149 } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
1150 if (tracing) {
1151 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1152 }
1153 uint32_t nonce = bytes_to_num(response5,4);
1154 uint32_t nr = bytes_to_num(receivedCmd,4);
1155 uint32_t ar = bytes_to_num(receivedCmd+4,4);
1156 //Dbprintf("Auth attempt {nonce}{nr}{ar}: %08x %08x %08x", nonce, nr, ar);
1157
1158 if(flags & FLAG_NR_AR_ATTACK )
1159 {
1160 if(ar_nr_collected < 2){
1161 // Avoid duplicates... probably not necessary, nr should vary.
1162 //if(ar_nr_responses[3] != nr){
1163 ar_nr_responses[ar_nr_collected*5] = 0;
1164 ar_nr_responses[ar_nr_collected*5+1] = 0;
1165 ar_nr_responses[ar_nr_collected*5+2] = nonce;
1166 ar_nr_responses[ar_nr_collected*5+3] = nr;
1167 ar_nr_responses[ar_nr_collected*5+4] = ar;
1168 ar_nr_collected++;
1169 //}
1170 }
1171
1172 if(ar_nr_collected > 1 ) {
1173
1174 if (MF_DBGLEVEL >= 2) {
1175 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
1176 Dbprintf("../tools/mfkey/mfkey32 %07x%08x %08x %08x %08x %08x %08x",
1177 ar_nr_responses[0], // UID1
1178 ar_nr_responses[1], // UID2
1179 ar_nr_responses[2], // NT
1180 ar_nr_responses[3], // AR1
1181 ar_nr_responses[4], // NR1
1182 ar_nr_responses[8], // AR2
1183 ar_nr_responses[9] // NR2
1184 );
1185 }
1186 uint8_t len = ar_nr_collected*5*4;
1187 cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,len,0,&ar_nr_responses,len);
1188 ar_nr_collected = 0;
1189 memset(ar_nr_responses, 0x00, len);
1190 }
1191 }
1192 } else {
1193 // Check for ISO 14443A-4 compliant commands, look at left nibble
1194 switch (receivedCmd[0]) {
1195
1196 case 0x0B:
1197 case 0x0A: { // IBlock (command)
1198 dynamic_response_info.response[0] = receivedCmd[0];
1199 dynamic_response_info.response[1] = 0x00;
1200 dynamic_response_info.response[2] = 0x90;
1201 dynamic_response_info.response[3] = 0x00;
1202 dynamic_response_info.response_n = 4;
1203 } break;
1204
1205 case 0x1A:
1206 case 0x1B: { // Chaining command
1207 dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1208 dynamic_response_info.response_n = 2;
1209 } break;
1210
1211 case 0xaa:
1212 case 0xbb: {
1213 dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1214 dynamic_response_info.response_n = 2;
1215 } break;
1216
1217 case 0xBA: { //
1218 memcpy(dynamic_response_info.response,"\xAB\x00",2);
1219 dynamic_response_info.response_n = 2;
1220 } break;
1221
1222 case 0xCA:
1223 case 0xC2: { // Readers sends deselect command
1224 memcpy(dynamic_response_info.response,"\xCA\x00",2);
1225 dynamic_response_info.response_n = 2;
1226 } break;
1227
1228 default: {
1229 // Never seen this command before
1230 if (tracing) {
1231 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1232 }
1233 Dbprintf("Received unknown command (len=%d):",len);
1234 Dbhexdump(len,receivedCmd,false);
1235 // Do not respond
1236 dynamic_response_info.response_n = 0;
1237 } break;
1238 }
1239
1240 if (dynamic_response_info.response_n > 0) {
1241 // Copy the CID from the reader query
1242 dynamic_response_info.response[1] = receivedCmd[1];
1243
1244 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1245 AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
1246 dynamic_response_info.response_n += 2;
1247
1248 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1249 Dbprintf("Error preparing tag response");
1250 if (tracing) {
1251 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1252 }
1253 break;
1254 }
1255 p_response = &dynamic_response_info;
1256 }
1257 }
1258
1259 // Count number of wakeups received after a halt
1260 if(order == 6 && lastorder == 5) { happened++; }
1261
1262 // Count number of other messages after a halt
1263 if(order != 6 && lastorder == 5) { happened2++; }
1264
1265 if(cmdsRecvd > 999) {
1266 DbpString("1000 commands later...");
1267 break;
1268 }
1269 cmdsRecvd++;
1270
1271 if (p_response != NULL) {
1272 EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1273 // do the tracing for the previous reader request and this tag answer:
1274 uint8_t par[MAX_PARITY_SIZE];
1275 GetParity(p_response->response, p_response->response_n, par);
1276
1277 EmLogTrace(Uart.output,
1278 Uart.len,
1279 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1280 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1281 Uart.parity,
1282 p_response->response,
1283 p_response->response_n,
1284 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1285 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1286 par);
1287 }
1288
1289 if (!tracing) {
1290 Dbprintf("Trace Full. Simulation stopped.");
1291 break;
1292 }
1293 }
1294
1295 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1296
1297 Dbprintf("%x %x %x", happened, happened2, cmdsRecvd);
1298 LED_A_OFF();
1299 BigBuf_free_keep_EM();
1300 }
1301
1302
1303 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1304 // of bits specified in the delay parameter.
1305 void PrepareDelayedTransfer(uint16_t delay)
1306 {
1307 uint8_t bitmask = 0;
1308 uint8_t bits_to_shift = 0;
1309 uint8_t bits_shifted = 0;
1310
1311 delay &= 0x07;
1312 if (delay) {
1313 for (uint16_t i = 0; i < delay; i++) {
1314 bitmask |= (0x01 << i);
1315 }
1316 ToSend[ToSendMax++] = 0x00;
1317 for (uint16_t i = 0; i < ToSendMax; i++) {
1318 bits_to_shift = ToSend[i] & bitmask;
1319 ToSend[i] = ToSend[i] >> delay;
1320 ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1321 bits_shifted = bits_to_shift;
1322 }
1323 }
1324 }
1325
1326
1327 //-------------------------------------------------------------------------------------
1328 // Transmit the command (to the tag) that was placed in ToSend[].
1329 // Parameter timing:
1330 // if NULL: transfer at next possible time, taking into account
1331 // request guard time and frame delay time
1332 // if == 0: transfer immediately and return time of transfer
1333 // if != 0: delay transfer until time specified
1334 //-------------------------------------------------------------------------------------
1335 static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing)
1336 {
1337
1338 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1339
1340 uint32_t ThisTransferTime = 0;
1341
1342 if (timing) {
1343 if(*timing == 0) { // Measure time
1344 *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1345 } else {
1346 PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
1347 }
1348 if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
1349 while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
1350 LastTimeProxToAirStart = *timing;
1351 } else {
1352 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1353 while(GetCountSspClk() < ThisTransferTime);
1354 LastTimeProxToAirStart = ThisTransferTime;
1355 }
1356
1357 // clear TXRDY
1358 AT91C_BASE_SSC->SSC_THR = SEC_Y;
1359
1360 uint16_t c = 0;
1361 for(;;) {
1362 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1363 AT91C_BASE_SSC->SSC_THR = cmd[c];
1364 c++;
1365 if(c >= len) {
1366 break;
1367 }
1368 }
1369 }
1370
1371 NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1372 }
1373
1374
1375 //-----------------------------------------------------------------------------
1376 // Prepare reader command (in bits, support short frames) to send to FPGA
1377 //-----------------------------------------------------------------------------
1378 void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity)
1379 {
1380 int i, j;
1381 int last;
1382 uint8_t b;
1383
1384 ToSendReset();
1385
1386 // Start of Communication (Seq. Z)
1387 ToSend[++ToSendMax] = SEC_Z;
1388 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1389 last = 0;
1390
1391 size_t bytecount = nbytes(bits);
1392 // Generate send structure for the data bits
1393 for (i = 0; i < bytecount; i++) {
1394 // Get the current byte to send
1395 b = cmd[i];
1396 size_t bitsleft = MIN((bits-(i*8)),8);
1397
1398 for (j = 0; j < bitsleft; j++) {
1399 if (b & 1) {
1400 // Sequence X
1401 ToSend[++ToSendMax] = SEC_X;
1402 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1403 last = 1;
1404 } else {
1405 if (last == 0) {
1406 // Sequence Z
1407 ToSend[++ToSendMax] = SEC_Z;
1408 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1409 } else {
1410 // Sequence Y
1411 ToSend[++ToSendMax] = SEC_Y;
1412 last = 0;
1413 }
1414 }
1415 b >>= 1;
1416 }
1417
1418 // Only transmit parity bit if we transmitted a complete byte
1419 if (j == 8 && parity != NULL) {
1420 // Get the parity bit
1421 if (parity[i>>3] & (0x80 >> (i&0x0007))) {
1422 // Sequence X
1423 ToSend[++ToSendMax] = SEC_X;
1424 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1425 last = 1;
1426 } else {
1427 if (last == 0) {
1428 // Sequence Z
1429 ToSend[++ToSendMax] = SEC_Z;
1430 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1431 } else {
1432 // Sequence Y
1433 ToSend[++ToSendMax] = SEC_Y;
1434 last = 0;
1435 }
1436 }
1437 }
1438 }
1439
1440 // End of Communication: Logic 0 followed by Sequence Y
1441 if (last == 0) {
1442 // Sequence Z
1443 ToSend[++ToSendMax] = SEC_Z;
1444 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1445 } else {
1446 // Sequence Y
1447 ToSend[++ToSendMax] = SEC_Y;
1448 last = 0;
1449 }
1450 ToSend[++ToSendMax] = SEC_Y;
1451
1452 // Convert to length of command:
1453 ToSendMax++;
1454 }
1455
1456 //-----------------------------------------------------------------------------
1457 // Prepare reader command to send to FPGA
1458 //-----------------------------------------------------------------------------
1459 void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity)
1460 {
1461 CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
1462 }
1463
1464
1465 //-----------------------------------------------------------------------------
1466 // Wait for commands from reader
1467 // Stop when button is pressed (return 1) or field was gone (return 2)
1468 // Or return 0 when command is captured
1469 //-----------------------------------------------------------------------------
1470 static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity)
1471 {
1472 *len = 0;
1473
1474 uint32_t timer = 0, vtime = 0;
1475 int analogCnt = 0;
1476 int analogAVG = 0;
1477
1478 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1479 // only, since we are receiving, not transmitting).
1480 // Signal field is off with the appropriate LED
1481 LED_D_OFF();
1482 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1483
1484 // Set ADC to read field strength
1485 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1486 AT91C_BASE_ADC->ADC_MR =
1487 ADC_MODE_PRESCALE(63) |
1488 ADC_MODE_STARTUP_TIME(1) |
1489 ADC_MODE_SAMPLE_HOLD_TIME(15);
1490 AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1491 // start ADC
1492 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1493
1494 // Now run a 'software UART' on the stream of incoming samples.
1495 UartInit(received, parity);
1496
1497 // Clear RXRDY:
1498 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1499
1500 for(;;) {
1501 WDT_HIT();
1502
1503 if (BUTTON_PRESS()) return 1;
1504
1505 // test if the field exists
1506 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1507 analogCnt++;
1508 analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1509 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1510 if (analogCnt >= 32) {
1511 if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1512 vtime = GetTickCount();
1513 if (!timer) timer = vtime;
1514 // 50ms no field --> card to idle state
1515 if (vtime - timer > 50) return 2;
1516 } else
1517 if (timer) timer = 0;
1518 analogCnt = 0;
1519 analogAVG = 0;
1520 }
1521 }
1522
1523 // receive and test the miller decoding
1524 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1525 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1526 if(MillerDecoding(b, 0)) {
1527 *len = Uart.len;
1528 return 0;
1529 }
1530 }
1531
1532 }
1533 }
1534
1535
1536 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded)
1537 {
1538 uint8_t b;
1539 uint16_t i = 0;
1540 uint32_t ThisTransferTime;
1541
1542 // Modulate Manchester
1543 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1544
1545 // include correction bit if necessary
1546 if (Uart.parityBits & 0x01) {
1547 correctionNeeded = TRUE;
1548 }
1549 if(correctionNeeded) {
1550 // 1236, so correction bit needed
1551 i = 0;
1552 } else {
1553 i = 1;
1554 }
1555
1556 // clear receiving shift register and holding register
1557 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1558 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1559 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1560 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1561
1562 // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1563 for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never
1564 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1565 if (AT91C_BASE_SSC->SSC_RHR) break;
1566 }
1567
1568 while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1569
1570 // Clear TXRDY:
1571 AT91C_BASE_SSC->SSC_THR = SEC_F;
1572
1573 // send cycle
1574 for(; i < respLen; ) {
1575 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1576 AT91C_BASE_SSC->SSC_THR = resp[i++];
1577 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1578 }
1579
1580 if(BUTTON_PRESS()) {
1581 break;
1582 }
1583 }
1584
1585 // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1586 uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3;
1587 for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
1588 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1589 AT91C_BASE_SSC->SSC_THR = SEC_F;
1590 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1591 i++;
1592 }
1593 }
1594
1595 LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
1596
1597 return 0;
1598 }
1599
1600 int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
1601 Code4bitAnswerAsTag(resp);
1602 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1603 // do the tracing for the previous reader request and this tag answer:
1604 uint8_t par[1];
1605 GetParity(&resp, 1, par);
1606 EmLogTrace(Uart.output,
1607 Uart.len,
1608 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1609 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1610 Uart.parity,
1611 &resp,
1612 1,
1613 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1614 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1615 par);
1616 return res;
1617 }
1618
1619 int EmSend4bit(uint8_t resp){
1620 return EmSend4bitEx(resp, false);
1621 }
1622
1623 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){
1624 CodeIso14443aAsTagPar(resp, respLen, par);
1625 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1626 // do the tracing for the previous reader request and this tag answer:
1627 EmLogTrace(Uart.output,
1628 Uart.len,
1629 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1630 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1631 Uart.parity,
1632 resp,
1633 respLen,
1634 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1635 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1636 par);
1637 return res;
1638 }
1639
1640 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){
1641 uint8_t par[MAX_PARITY_SIZE];
1642 GetParity(resp, respLen, par);
1643 return EmSendCmdExPar(resp, respLen, correctionNeeded, par);
1644 }
1645
1646 int EmSendCmd(uint8_t *resp, uint16_t respLen){
1647 uint8_t par[MAX_PARITY_SIZE];
1648 GetParity(resp, respLen, par);
1649 return EmSendCmdExPar(resp, respLen, false, par);
1650 }
1651
1652 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
1653 return EmSendCmdExPar(resp, respLen, false, par);
1654 }
1655
1656 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
1657 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity)
1658 {
1659 if (tracing) {
1660 // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1661 // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1662 // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1663 uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1664 uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1665 uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1666 reader_EndTime = tag_StartTime - exact_fdt;
1667 reader_StartTime = reader_EndTime - reader_modlen;
1668 if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE)) {
1669 return FALSE;
1670 } else return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
1671 } else {
1672 return TRUE;
1673 }
1674 }
1675
1676 //-----------------------------------------------------------------------------
1677 // Wait a certain time for tag response
1678 // If a response is captured return TRUE
1679 // If it takes too long return FALSE
1680 //-----------------------------------------------------------------------------
1681 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset)
1682 {
1683 uint32_t c = 0x00;
1684
1685 // Set FPGA mode to "reader listen mode", no modulation (listen
1686 // only, since we are receiving, not transmitting).
1687 // Signal field is on with the appropriate LED
1688 LED_D_ON();
1689 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1690
1691 // Now get the answer from the card
1692 DemodInit(receivedResponse, receivedResponsePar);
1693
1694 // clear RXRDY:
1695 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1696
1697 for(;;) {
1698 WDT_HIT();
1699
1700 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1701 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1702 if(ManchesterDecoding(b, offset, 0)) {
1703 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1704 return TRUE;
1705 } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
1706 return FALSE;
1707 }
1708 }
1709 }
1710 }
1711
1712
1713 void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing)
1714 {
1715 CodeIso14443aBitsAsReaderPar(frame, bits, par);
1716
1717 // Send command to tag
1718 TransmitFor14443a(ToSend, ToSendMax, timing);
1719 if(trigger)
1720 LED_A_ON();
1721
1722 // Log reader command in trace buffer
1723 if (tracing) {
1724 LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
1725 }
1726 }
1727
1728
1729 void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing)
1730 {
1731 ReaderTransmitBitsPar(frame, len*8, par, timing);
1732 }
1733
1734
1735 void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing)
1736 {
1737 // Generate parity and redirect
1738 uint8_t par[MAX_PARITY_SIZE];
1739 GetParity(frame, len/8, par);
1740 ReaderTransmitBitsPar(frame, len, par, timing);
1741 }
1742
1743
1744 void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing)
1745 {
1746 // Generate parity and redirect
1747 uint8_t par[MAX_PARITY_SIZE];
1748 GetParity(frame, len, par);
1749 ReaderTransmitBitsPar(frame, len*8, par, timing);
1750 }
1751
1752 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity)
1753 {
1754 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset)) return FALSE;
1755 if (tracing) {
1756 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1757 }
1758 return Demod.len;
1759 }
1760
1761 int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
1762 {
1763 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0)) return FALSE;
1764 if (tracing) {
1765 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1766 }
1767 return Demod.len;
1768 }
1769
1770 /* performs iso14443a anticollision procedure
1771 * fills the uid pointer unless NULL
1772 * fills resp_data unless NULL */
1773 int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr) {
1774 uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP
1775 uint8_t sel_all[] = { 0x93,0x20 };
1776 uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1777 uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1778 uint8_t resp[MAX_FRAME_SIZE]; // theoretically. A usual RATS will be much smaller
1779 uint8_t resp_par[MAX_PARITY_SIZE];
1780 byte_t uid_resp[4];
1781 size_t uid_resp_len;
1782
1783 uint8_t sak = 0x04; // cascade uid
1784 int cascade_level = 0;
1785 int len;
1786
1787 // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1788 ReaderTransmitBitsPar(wupa,7,0, NULL);
1789
1790 // Receive the ATQA
1791 if(!ReaderReceive(resp, resp_par)) return 0;
1792
1793 if(p_hi14a_card) {
1794 memcpy(p_hi14a_card->atqa, resp, 2);
1795 p_hi14a_card->uidlen = 0;
1796 memset(p_hi14a_card->uid,0,10);
1797 }
1798
1799 // clear uid
1800 if (uid_ptr) {
1801 memset(uid_ptr,0,10);
1802 }
1803
1804 // check for proprietary anticollision:
1805 if ((resp[0] & 0x1F) == 0) {
1806 return 3;
1807 }
1808
1809 // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1810 // which case we need to make a cascade 2 request and select - this is a long UID
1811 // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1812 for(; sak & 0x04; cascade_level++) {
1813 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1814 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1815
1816 // SELECT_ALL
1817 ReaderTransmit(sel_all, sizeof(sel_all), NULL);
1818 if (!ReaderReceive(resp, resp_par)) return 0;
1819
1820 if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit
1821 memset(uid_resp, 0, 4);
1822 uint16_t uid_resp_bits = 0;
1823 uint16_t collision_answer_offset = 0;
1824 // anti-collision-loop:
1825 while (Demod.collisionPos) {
1826 Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1827 for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point
1828 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1829 uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8);
1830 }
1831 uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position
1832 uid_resp_bits++;
1833 // construct anticollosion command:
1834 sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits
1835 for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1836 sel_uid[2+i] = uid_resp[i];
1837 }
1838 collision_answer_offset = uid_resp_bits%8;
1839 ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1840 if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0;
1841 }
1842 // finally, add the last bits and BCC of the UID
1843 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1844 uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1845 uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1846 }
1847
1848 } else { // no collision, use the response to SELECT_ALL as current uid
1849 memcpy(uid_resp, resp, 4);
1850 }
1851 uid_resp_len = 4;
1852
1853 // calculate crypto UID. Always use last 4 Bytes.
1854 if(cuid_ptr) {
1855 *cuid_ptr = bytes_to_num(uid_resp, 4);
1856 }
1857
1858 // Construct SELECT UID command
1859 sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1860 memcpy(sel_uid+2, uid_resp, 4); // the UID
1861 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC
1862 AppendCrc14443a(sel_uid, 7); // calculate and add CRC
1863 ReaderTransmit(sel_uid, sizeof(sel_uid), NULL);
1864
1865 // Receive the SAK
1866 if (!ReaderReceive(resp, resp_par)) return 0;
1867 sak = resp[0];
1868
1869 // Test if more parts of the uid are coming
1870 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
1871 // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
1872 // http://www.nxp.com/documents/application_note/AN10927.pdf
1873 uid_resp[0] = uid_resp[1];
1874 uid_resp[1] = uid_resp[2];
1875 uid_resp[2] = uid_resp[3];
1876
1877 uid_resp_len = 3;
1878 }
1879
1880 if(uid_ptr) {
1881 memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
1882 }
1883
1884 if(p_hi14a_card) {
1885 memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
1886 p_hi14a_card->uidlen += uid_resp_len;
1887 }
1888 }
1889
1890 if(p_hi14a_card) {
1891 p_hi14a_card->sak = sak;
1892 p_hi14a_card->ats_len = 0;
1893 }
1894
1895 // non iso14443a compliant tag
1896 if( (sak & 0x20) == 0) return 2;
1897
1898 // Request for answer to select
1899 AppendCrc14443a(rats, 2);
1900 ReaderTransmit(rats, sizeof(rats), NULL);
1901
1902 if (!(len = ReaderReceive(resp, resp_par))) return 0;
1903
1904
1905 if(p_hi14a_card) {
1906 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
1907 p_hi14a_card->ats_len = len;
1908 }
1909
1910 // reset the PCB block number
1911 iso14_pcb_blocknum = 0;
1912
1913 // set default timeout based on ATS
1914 iso14a_set_ATS_timeout(resp);
1915
1916 return 1;
1917 }
1918
1919 void iso14443a_setup(uint8_t fpga_minor_mode) {
1920 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1921 // Set up the synchronous serial port
1922 FpgaSetupSsc();
1923 // connect Demodulated Signal to ADC:
1924 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1925
1926 // Signal field is on with the appropriate LED
1927 if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
1928 || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
1929 LED_D_ON();
1930 } else {
1931 LED_D_OFF();
1932 }
1933 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
1934
1935 // Start the timer
1936 StartCountSspClk();
1937
1938 DemodReset();
1939 UartReset();
1940 NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
1941 iso14a_set_timeout(10*106); // 10ms default
1942 }
1943
1944 int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
1945 uint8_t parity[MAX_PARITY_SIZE];
1946 uint8_t real_cmd[cmd_len+4];
1947 real_cmd[0] = 0x0a; //I-Block
1948 // put block number into the PCB
1949 real_cmd[0] |= iso14_pcb_blocknum;
1950 real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
1951 memcpy(real_cmd+2, cmd, cmd_len);
1952 AppendCrc14443a(real_cmd,cmd_len+2);
1953
1954 ReaderTransmit(real_cmd, cmd_len+4, NULL);
1955 size_t len = ReaderReceive(data, parity);
1956 uint8_t *data_bytes = (uint8_t *) data;
1957 if (!len)
1958 return 0; //DATA LINK ERROR
1959 // if we received an I- or R(ACK)-Block with a block number equal to the
1960 // current block number, toggle the current block number
1961 else if (len >= 4 // PCB+CID+CRC = 4 bytes
1962 && ((data_bytes[0] & 0xC0) == 0 // I-Block
1963 || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
1964 && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
1965 {
1966 iso14_pcb_blocknum ^= 1;
1967 }
1968
1969 return len;
1970 }
1971
1972 //-----------------------------------------------------------------------------
1973 // Read an ISO 14443a tag. Send out commands and store answers.
1974 //
1975 //-----------------------------------------------------------------------------
1976 void ReaderIso14443a(UsbCommand *c)
1977 {
1978 iso14a_command_t param = c->arg[0];
1979 uint8_t *cmd = c->d.asBytes;
1980 size_t len = c->arg[1] & 0xffff;
1981 size_t lenbits = c->arg[1] >> 16;
1982 uint32_t timeout = c->arg[2];
1983 uint32_t arg0 = 0;
1984 byte_t buf[USB_CMD_DATA_SIZE];
1985 uint8_t par[MAX_PARITY_SIZE];
1986
1987 if(param & ISO14A_CONNECT) {
1988 clear_trace();
1989 }
1990
1991 set_tracing(TRUE);
1992
1993 if(param & ISO14A_REQUEST_TRIGGER) {
1994 iso14a_set_trigger(TRUE);
1995 }
1996
1997 if(param & ISO14A_CONNECT) {
1998 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
1999 if(!(param & ISO14A_NO_SELECT)) {
2000 iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
2001 arg0 = iso14443a_select_card(NULL,card,NULL);
2002 cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
2003 }
2004 }
2005
2006 if(param & ISO14A_SET_TIMEOUT) {
2007 iso14a_set_timeout(timeout);
2008 }
2009
2010 if(param & ISO14A_APDU) {
2011 arg0 = iso14_apdu(cmd, len, buf);
2012 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2013 }
2014
2015 if(param & ISO14A_RAW) {
2016 if(param & ISO14A_APPEND_CRC) {
2017 if(param & ISO14A_TOPAZMODE) {
2018 AppendCrc14443b(cmd,len);
2019 } else {
2020 AppendCrc14443a(cmd,len);
2021 }
2022 len += 2;
2023 if (lenbits) lenbits += 16;
2024 }
2025 if(lenbits>0) { // want to send a specific number of bits (e.g. short commands)
2026 if(param & ISO14A_TOPAZMODE) {
2027 int bits_to_send = lenbits;
2028 uint16_t i = 0;
2029 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL); // first byte is always short (7bits) and no parity
2030 bits_to_send -= 7;
2031 while (bits_to_send > 0) {
2032 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL); // following bytes are 8 bit and no parity
2033 bits_to_send -= 8;
2034 }
2035 } else {
2036 GetParity(cmd, lenbits/8, par);
2037 ReaderTransmitBitsPar(cmd, lenbits, par, NULL); // bytes are 8 bit with odd parity
2038 }
2039 } else { // want to send complete bytes only
2040 if(param & ISO14A_TOPAZMODE) {
2041 uint16_t i = 0;
2042 ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL); // first byte: 7 bits, no paritiy
2043 while (i < len) {
2044 ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL); // following bytes: 8 bits, no paritiy
2045 }
2046 } else {
2047 ReaderTransmit(cmd,len, NULL); // 8 bits, odd parity
2048 }
2049 }
2050 arg0 = ReaderReceive(buf, par);
2051 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2052 }
2053
2054 if(param & ISO14A_REQUEST_TRIGGER) {
2055 iso14a_set_trigger(FALSE);
2056 }
2057
2058 if(param & ISO14A_NO_DISCONNECT) {
2059 return;
2060 }
2061
2062 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2063 LEDsoff();
2064 }
2065
2066
2067 // Determine the distance between two nonces.
2068 // Assume that the difference is small, but we don't know which is first.
2069 // Therefore try in alternating directions.
2070 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
2071
2072 if (nt1 == nt2) return 0;
2073
2074 uint16_t i;
2075 uint32_t nttmp1 = nt1;
2076 uint32_t nttmp2 = nt2;
2077
2078 for (i = 1; i < 32768; i++) {
2079 nttmp1 = prng_successor(nttmp1, 1);
2080 if (nttmp1 == nt2) return i;
2081 nttmp2 = prng_successor(nttmp2, 1);
2082 if (nttmp2 == nt1) return -i;
2083 }
2084
2085 return(-99999); // either nt1 or nt2 are invalid nonces
2086 }
2087
2088
2089 //-----------------------------------------------------------------------------
2090 // Recover several bits of the cypher stream. This implements (first stages of)
2091 // the algorithm described in "The Dark Side of Security by Obscurity and
2092 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
2093 // (article by Nicolas T. Courtois, 2009)
2094 //-----------------------------------------------------------------------------
2095 void ReaderMifare(bool first_try) {
2096 // free eventually allocated BigBuf memory. We want all for tracing.
2097 BigBuf_free();
2098
2099 clear_trace();
2100 set_tracing(TRUE);
2101
2102 // Mifare AUTH
2103 uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b };
2104 uint8_t mf_nr_ar[8] = { 0x00 }; //{ 0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01 };
2105 static uint8_t mf_nr_ar3 = 0;
2106
2107 uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE] = { 0x00 };
2108 uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE] = { 0x00 };
2109
2110 byte_t nt_diff = 0;
2111 uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
2112 static byte_t par_low = 0;
2113 bool led_on = TRUE;
2114 uint8_t uid[10] = {0x00};
2115 //uint32_t cuid = 0x00;
2116
2117 uint32_t nt = 0;
2118 uint32_t previous_nt = 0;
2119 static uint32_t nt_attacked = 0;
2120 byte_t par_list[8] = {0x00};
2121 byte_t ks_list[8] = {0x00};
2122
2123 static uint32_t sync_time = 0;
2124 static uint32_t sync_cycles = 0;
2125 int catch_up_cycles = 0;
2126 int last_catch_up = 0;
2127 uint16_t consecutive_resyncs = 0;
2128 int isOK = 0;
2129
2130 int numWrongDistance = 0;
2131
2132 if (first_try) {
2133 mf_nr_ar3 = 0;
2134 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2135 sync_time = GetCountSspClk() & 0xfffffff8;
2136 sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
2137 nt_attacked = 0;
2138 nt = 0;
2139 par[0] = 0;
2140 }
2141 else {
2142 // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
2143 mf_nr_ar3++;
2144 mf_nr_ar[3] = mf_nr_ar3;
2145 par[0] = par_low;
2146 }
2147
2148 LED_A_ON();
2149 LED_B_OFF();
2150 LED_C_OFF();
2151 LED_C_ON();
2152
2153 for(uint16_t i = 0; TRUE; i++) {
2154
2155 WDT_HIT();
2156
2157 // Test if the action was cancelled
2158 if(BUTTON_PRESS()) break;
2159
2160 if (numWrongDistance > 1000) {
2161 isOK = 0;
2162 break;
2163 }
2164
2165 //if(!iso14443a_select_card(uid, NULL, &cuid)) {
2166 if(!iso14443a_select_card(uid, NULL, NULL)) {
2167 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
2168 continue;
2169 }
2170
2171 sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
2172 catch_up_cycles = 0;
2173
2174 // if we missed the sync time already, advance to the next nonce repeat
2175 while(GetCountSspClk() > sync_time) {
2176 sync_time = (sync_time & 0xfffffff8) + sync_cycles;
2177 }
2178
2179 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2180 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2181
2182 // Receive the (4 Byte) "random" nonce
2183 if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2184 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce");
2185 continue;
2186 }
2187
2188 previous_nt = nt;
2189 nt = bytes_to_num(receivedAnswer, 4);
2190
2191 // Transmit reader nonce with fake par
2192 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2193
2194 if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
2195 int nt_distance = dist_nt(previous_nt, nt);
2196 if (nt_distance == 0) {
2197 nt_attacked = nt;
2198 }
2199 else {
2200
2201 // invalid nonce received, try again
2202 if (nt_distance == -99999) {
2203 numWrongDistance++;
2204 if (MF_DBGLEVEL >= 3) Dbprintf("The two nonces has invalid distance, tag could have good PRNG\n");
2205 continue;
2206 }
2207
2208 sync_cycles = (sync_cycles - nt_distance);
2209 if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
2210 continue;
2211 }
2212 }
2213
2214 if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
2215 catch_up_cycles = -dist_nt(nt_attacked, nt);
2216 if (catch_up_cycles >= 99999) { // invalid nonce received. Don't resync on that one.
2217 catch_up_cycles = 0;
2218 continue;
2219 }
2220 if (catch_up_cycles == last_catch_up) {
2221 consecutive_resyncs++;
2222 }
2223 else {
2224 last_catch_up = catch_up_cycles;
2225 consecutive_resyncs = 0;
2226 }
2227 if (consecutive_resyncs < 3) {
2228 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);
2229 }
2230 else {
2231 sync_cycles = sync_cycles + catch_up_cycles;
2232 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);
2233 }
2234 continue;
2235 }
2236
2237 consecutive_resyncs = 0;
2238
2239 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2240 if (ReaderReceive(receivedAnswer, receivedAnswerPar))
2241 {
2242 catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2243
2244 if (nt_diff == 0)
2245 {
2246 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
2247 }
2248
2249 led_on = !led_on;
2250 if(led_on) LED_B_ON(); else LED_B_OFF();
2251
2252 par_list[nt_diff] = SwapBits(par[0], 8);
2253 ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
2254
2255 // Test if the information is complete
2256 if (nt_diff == 0x07) {
2257 isOK = 1;
2258 break;
2259 }
2260
2261 nt_diff = (nt_diff + 1) & 0x07;
2262 mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2263 par[0] = par_low;
2264 } else {
2265 if (nt_diff == 0 && first_try)
2266 {
2267 par[0]++;
2268 } else {
2269 par[0] = ((par[0] & 0x1F) + 1) | par_low;
2270 }
2271 }
2272 }
2273
2274 mf_nr_ar[3] &= 0x1F;
2275
2276 byte_t buf[28] = {0x00};
2277
2278 memcpy(buf + 0, uid, 4);
2279 num_to_bytes(nt, 4, buf + 4);
2280 memcpy(buf + 8, par_list, 8);
2281 memcpy(buf + 16, ks_list, 8);
2282 memcpy(buf + 24, mf_nr_ar, 4);
2283
2284 cmd_send(CMD_ACK,isOK,0,0,buf,28);
2285
2286 set_tracing(FALSE);
2287 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2288 LEDsoff();
2289 }
2290
2291
2292 /*
2293 *MIFARE 1K simulate.
2294 *
2295 *@param flags :
2296 * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2297 * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
2298 * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
2299 * FLAG_NR_AR_ATTACK - means we should collect NR_AR responses for bruteforcing later
2300 *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2301 */
2302 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
2303 {
2304 int cardSTATE = MFEMUL_NOFIELD;
2305 int _7BUID = 0;
2306 int vHf = 0; // in mV
2307 int res;
2308 uint32_t selTimer = 0;
2309 uint32_t authTimer = 0;
2310 uint16_t len = 0;
2311 uint8_t cardWRBL = 0;
2312 uint8_t cardAUTHSC = 0;
2313 uint8_t cardAUTHKEY = 0xff; // no authentication
2314 // uint32_t cardRr = 0;
2315 uint32_t cuid = 0;
2316 //uint32_t rn_enc = 0;
2317 uint32_t ans = 0;
2318 uint32_t cardINTREG = 0;
2319 uint8_t cardINTBLOCK = 0;
2320 struct Crypto1State mpcs = {0, 0};
2321 struct Crypto1State *pcs;
2322 pcs = &mpcs;
2323 uint32_t numReads = 0;//Counts numer of times reader read a block
2324 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
2325 uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE];
2326 uint8_t response[MAX_MIFARE_FRAME_SIZE];
2327 uint8_t response_par[MAX_MIFARE_PARITY_SIZE];
2328
2329 uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
2330 uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2331 uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
2332 //uint8_t rSAK[] = {0x08, 0xb6, 0xdd}; // Mifare Classic
2333 uint8_t rSAK[] = {0x09, 0x3f, 0xcc }; // Mifare Mini
2334 uint8_t rSAK1[] = {0x04, 0xda, 0x17};
2335
2336 uint8_t rAUTH_NT[] = {0x01, 0x01, 0x01, 0x01};
2337 uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2338
2339 //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
2340 // This can be used in a reader-only attack.
2341 // (it can also be retrieved via 'hf 14a list', but hey...
2342 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0,0,0};
2343 uint8_t ar_nr_collected = 0;
2344
2345 // free eventually allocated BigBuf memory but keep Emulator Memory
2346 BigBuf_free_keep_EM();
2347
2348 // clear trace
2349 clear_trace();
2350 set_tracing(TRUE);
2351
2352 // Authenticate response - nonce
2353 uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2354
2355 //-- Determine the UID
2356 // Can be set from emulator memory, incoming data
2357 // and can be 7 or 4 bytes long
2358 if (flags & FLAG_4B_UID_IN_DATA)
2359 {
2360 // 4B uid comes from data-portion of packet
2361 memcpy(rUIDBCC1,datain,4);
2362 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2363
2364 } else if (flags & FLAG_7B_UID_IN_DATA) {
2365 // 7B uid comes from data-portion of packet
2366 memcpy(&rUIDBCC1[1],datain,3);
2367 memcpy(rUIDBCC2, datain+3, 4);
2368 _7BUID = true;
2369 } else {
2370 // get UID from emul memory
2371 emlGetMemBt(receivedCmd, 7, 1);
2372 _7BUID = !(receivedCmd[0] == 0x00);
2373 if (!_7BUID) { // ---------- 4BUID
2374 emlGetMemBt(rUIDBCC1, 0, 4);
2375 } else { // ---------- 7BUID
2376 emlGetMemBt(&rUIDBCC1[1], 0, 3);
2377 emlGetMemBt(rUIDBCC2, 3, 4);
2378 }
2379 }
2380
2381 // save uid.
2382 ar_nr_responses[0*5] = bytes_to_num(rUIDBCC1+1, 3);
2383 if ( _7BUID )
2384 ar_nr_responses[0*5+1] = bytes_to_num(rUIDBCC2, 4);
2385
2386 /*
2387 * Regardless of what method was used to set the UID, set fifth byte and modify
2388 * the ATQA for 4 or 7-byte UID
2389 */
2390 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2391 if (_7BUID) {
2392 rATQA[0] = 0x44;
2393 rUIDBCC1[0] = 0x88;
2394 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2395 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2396 }
2397
2398 // We need to listen to the high-frequency, peak-detected path.
2399 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2400
2401
2402 if (MF_DBGLEVEL >= 1) {
2403 if (!_7BUID) {
2404 Dbprintf("4B UID: %02x%02x%02x%02x",
2405 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3]);
2406 } else {
2407 Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",
2408 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3],
2409 rUIDBCC2[0], rUIDBCC2[1] ,rUIDBCC2[2], rUIDBCC2[3]);
2410 }
2411 }
2412
2413 bool finished = FALSE;
2414 while (!BUTTON_PRESS() && !finished) {
2415 WDT_HIT();
2416
2417 // find reader field
2418 if (cardSTATE == MFEMUL_NOFIELD) {
2419 vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
2420 if (vHf > MF_MINFIELDV) {
2421 cardSTATE_TO_IDLE();
2422 LED_A_ON();
2423 }
2424 }
2425 if(cardSTATE == MFEMUL_NOFIELD) continue;
2426
2427 //Now, get data
2428 res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
2429 if (res == 2) { //Field is off!
2430 cardSTATE = MFEMUL_NOFIELD;
2431 LEDsoff();
2432 continue;
2433 } else if (res == 1) {
2434 break; //return value 1 means button press
2435 }
2436
2437 // REQ or WUP request in ANY state and WUP in HALTED state
2438 if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
2439 selTimer = GetTickCount();
2440 EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
2441 cardSTATE = MFEMUL_SELECT1;
2442
2443 // init crypto block
2444 LED_B_OFF();
2445 LED_C_OFF();
2446 crypto1_destroy(pcs);
2447 cardAUTHKEY = 0xff;
2448 continue;
2449 }
2450
2451 switch (cardSTATE) {
2452 case MFEMUL_NOFIELD:
2453 case MFEMUL_HALTED:
2454 case MFEMUL_IDLE:{
2455 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2456 break;
2457 }
2458 case MFEMUL_SELECT1:{
2459 // select all
2460 if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
2461 if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received");
2462 EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2463 break;
2464 }
2465
2466 if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
2467 {
2468 Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
2469 }
2470 // select card
2471 if (len == 9 &&
2472 (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2473 EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK));
2474 cuid = bytes_to_num(rUIDBCC1, 4);
2475 if (!_7BUID) {
2476 cardSTATE = MFEMUL_WORK;
2477 LED_B_ON();
2478 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2479 break;
2480 } else {
2481 cardSTATE = MFEMUL_SELECT2;
2482 }
2483 }
2484 break;
2485 }
2486 case MFEMUL_AUTH1:{
2487 if( len != 8)
2488 {
2489 cardSTATE_TO_IDLE();
2490 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2491 break;
2492 }
2493
2494 uint32_t ar = bytes_to_num(receivedCmd, 4);
2495 uint32_t nr = bytes_to_num(&receivedCmd[4], 4);
2496
2497 //Collect AR/NR
2498 //if(ar_nr_collected < 2 && cardAUTHSC == 2){
2499 if(ar_nr_collected < 2){
2500 if(ar_nr_responses[2] != ar)
2501 {// Avoid duplicates... probably not necessary, ar should vary.
2502 //ar_nr_responses[ar_nr_collected*5] = 0;
2503 //ar_nr_responses[ar_nr_collected*5+1] = 0;
2504 ar_nr_responses[ar_nr_collected*5+2] = nonce;
2505 ar_nr_responses[ar_nr_collected*5+3] = nr;
2506 ar_nr_responses[ar_nr_collected*5+4] = ar;
2507 ar_nr_collected++;
2508 }
2509 // Interactive mode flag, means we need to send ACK
2510 if(flags & FLAG_INTERACTIVE && ar_nr_collected == 2)
2511 {
2512 finished = true;
2513 }
2514 }
2515
2516 // --- crypto
2517 //crypto1_word(pcs, ar , 1);
2518 //cardRr = nr ^ crypto1_word(pcs, 0, 0);
2519
2520 //test if auth OK
2521 //if (cardRr != prng_successor(nonce, 64)){
2522
2523 //if (MF_DBGLEVEL >= 4) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
2524 // cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2525 // cardRr, prng_successor(nonce, 64));
2526 // Shouldn't we respond anything here?
2527 // Right now, we don't nack or anything, which causes the
2528 // reader to do a WUPA after a while. /Martin
2529 // -- which is the correct response. /piwi
2530 //cardSTATE_TO_IDLE();
2531 //LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2532 //break;
2533 //}
2534
2535 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2536
2537 num_to_bytes(ans, 4, rAUTH_AT);
2538 // --- crypto
2539 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2540 LED_C_ON();
2541 cardSTATE = MFEMUL_WORK;
2542 if (MF_DBGLEVEL >= 4) Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2543 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2544 GetTickCount() - authTimer);
2545 break;
2546 }
2547 case MFEMUL_SELECT2:{
2548 if (!len) {
2549 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2550 break;
2551 }
2552 if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
2553 EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2554 break;
2555 }
2556
2557 // select 2 card
2558 if (len == 9 &&
2559 (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
2560 EmSendCmd(rSAK, sizeof(rSAK));
2561 cuid = bytes_to_num(rUIDBCC2, 4);
2562 cardSTATE = MFEMUL_WORK;
2563 LED_B_ON();
2564 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2565 break;
2566 }
2567
2568 // i guess there is a command). go into the work state.
2569 if (len != 4) {
2570 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2571 break;
2572 }
2573 cardSTATE = MFEMUL_WORK;
2574 //goto lbWORK;
2575 //intentional fall-through to the next case-stmt
2576 }
2577
2578 case MFEMUL_WORK:{
2579 if (len == 0) {
2580 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2581 break;
2582 }
2583
2584 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2585
2586 if(encrypted_data) {
2587 // decrypt seqence
2588 mf_crypto1_decrypt(pcs, receivedCmd, len);
2589 }
2590
2591 if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
2592 authTimer = GetTickCount();
2593 cardAUTHSC = receivedCmd[1] / 4; // received block num
2594 cardAUTHKEY = receivedCmd[0] - 0x60;
2595 crypto1_destroy(pcs);//Added by martin
2596 crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2597
2598 if (!encrypted_data) { // first authentication
2599 if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2600
2601 crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
2602 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2603 } else { // nested authentication
2604 if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2605 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2606 num_to_bytes(ans, 4, rAUTH_AT);
2607 }
2608
2609 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2610 //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
2611 cardSTATE = MFEMUL_AUTH1;
2612 break;
2613 }
2614
2615 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2616 // BUT... ACK --> NACK
2617 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2618 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2619 break;
2620 }
2621
2622 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2623 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2624 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2625 break;
2626 }
2627
2628 if(len != 4) {
2629 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2630 break;
2631 }
2632
2633 if(receivedCmd[0] == 0x30 // read block
2634 || receivedCmd[0] == 0xA0 // write block
2635 || receivedCmd[0] == 0xC0 // inc
2636 || receivedCmd[0] == 0xC1 // dec
2637 || receivedCmd[0] == 0xC2 // restore
2638 || receivedCmd[0] == 0xB0) { // transfer
2639 if (receivedCmd[1] >= 16 * 4) {
2640 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2641 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate (0x%02) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2642 break;
2643 }
2644
2645 if (receivedCmd[1] / 4 != cardAUTHSC) {
2646 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2647 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate (0x%02) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
2648 break;
2649 }
2650 }
2651 // read block
2652 if (receivedCmd[0] == 0x30) {
2653 if (MF_DBGLEVEL >= 4) {
2654 Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
2655 }
2656 emlGetMem(response, receivedCmd[1], 1);
2657 AppendCrc14443a(response, 16);
2658 mf_crypto1_encrypt(pcs, response, 18, response_par);
2659 EmSendCmdPar(response, 18, response_par);
2660 numReads++;
2661 if(exitAfterNReads > 0 && numReads >= exitAfterNReads) {
2662 Dbprintf("%d reads done, exiting", numReads);
2663 finished = true;
2664 }
2665 break;
2666 }
2667 // write block
2668 if (receivedCmd[0] == 0xA0) {
2669 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
2670 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2671 cardSTATE = MFEMUL_WRITEBL2;
2672 cardWRBL = receivedCmd[1];
2673 break;
2674 }
2675 // increment, decrement, restore
2676 if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
2677 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2678 if (emlCheckValBl(receivedCmd[1])) {
2679 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2680 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2681 break;
2682 }
2683 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2684 if (receivedCmd[0] == 0xC1)
2685 cardSTATE = MFEMUL_INTREG_INC;
2686 if (receivedCmd[0] == 0xC0)
2687 cardSTATE = MFEMUL_INTREG_DEC;
2688 if (receivedCmd[0] == 0xC2)
2689 cardSTATE = MFEMUL_INTREG_REST;
2690 cardWRBL = receivedCmd[1];
2691 break;
2692 }
2693 // transfer
2694 if (receivedCmd[0] == 0xB0) {
2695 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2696 if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2697 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2698 else
2699 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2700 break;
2701 }
2702 // halt
2703 if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
2704 LED_B_OFF();
2705 LED_C_OFF();
2706 cardSTATE = MFEMUL_HALTED;
2707 if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer);
2708 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2709 break;
2710 }
2711 // RATS
2712 if (receivedCmd[0] == 0xe0) {//RATS
2713 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2714 break;
2715 }
2716 // command not allowed
2717 if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking");
2718 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2719 break;
2720 }
2721 case MFEMUL_WRITEBL2:{
2722 if (len == 18){
2723 mf_crypto1_decrypt(pcs, receivedCmd, len);
2724 emlSetMem(receivedCmd, cardWRBL, 1);
2725 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2726 cardSTATE = MFEMUL_WORK;
2727 } else {
2728 cardSTATE_TO_IDLE();
2729 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2730 }
2731 break;
2732 }
2733
2734 case MFEMUL_INTREG_INC:{
2735 mf_crypto1_decrypt(pcs, receivedCmd, len);
2736 memcpy(&ans, receivedCmd, 4);
2737 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2738 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2739 cardSTATE_TO_IDLE();
2740 break;
2741 }
2742 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2743 cardINTREG = cardINTREG + ans;
2744 cardSTATE = MFEMUL_WORK;
2745 break;
2746 }
2747 case MFEMUL_INTREG_DEC:{
2748 mf_crypto1_decrypt(pcs, receivedCmd, len);
2749 memcpy(&ans, receivedCmd, 4);
2750 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2751 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2752 cardSTATE_TO_IDLE();
2753 break;
2754 }
2755 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2756 cardINTREG = cardINTREG - ans;
2757 cardSTATE = MFEMUL_WORK;
2758 break;
2759 }
2760 case MFEMUL_INTREG_REST:{
2761 mf_crypto1_decrypt(pcs, receivedCmd, len);
2762 memcpy(&ans, receivedCmd, 4);
2763 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2764 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2765 cardSTATE_TO_IDLE();
2766 break;
2767 }
2768 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2769 cardSTATE = MFEMUL_WORK;
2770 break;
2771 }
2772 }
2773 }
2774
2775 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2776 LEDsoff();
2777
2778 if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
2779 {
2780 //May just aswell send the collected ar_nr in the response aswell
2781 uint8_t len = ar_nr_collected*5*4;
2782 cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, len, 0, &ar_nr_responses, len);
2783 }
2784
2785 if(flags & FLAG_NR_AR_ATTACK && MF_DBGLEVEL >= 1 )
2786 {
2787 if(ar_nr_collected > 1 ) {
2788 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
2789 Dbprintf("../tools/mfkey/mfkey32 %06x%08x %08x %08x %08x %08x %08x",
2790 ar_nr_responses[0], // UID1
2791 ar_nr_responses[1], // UID2
2792 ar_nr_responses[2], // NT
2793 ar_nr_responses[3], // AR1
2794 ar_nr_responses[4], // NR1
2795 ar_nr_responses[8], // AR2
2796 ar_nr_responses[9] // NR2
2797 );
2798 } else {
2799 Dbprintf("Failed to obtain two AR/NR pairs!");
2800 if(ar_nr_collected > 0 ) {
2801 Dbprintf("Only got these: UID=%07x%08x, nonce=%08x, AR1=%08x, NR1=%08x",
2802 ar_nr_responses[0], // UID1
2803 ar_nr_responses[1], // UID2
2804 ar_nr_responses[2], // NT
2805 ar_nr_responses[3], // AR1
2806 ar_nr_responses[4] // NR1
2807 );
2808 }
2809 }
2810 }
2811 if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen());
2812 }
2813
2814
2815 //-----------------------------------------------------------------------------
2816 // MIFARE sniffer.
2817 //
2818 //-----------------------------------------------------------------------------
2819 void RAMFUNC SniffMifare(uint8_t param) {
2820 // param:
2821 // bit 0 - trigger from first card answer
2822 // bit 1 - trigger from first reader 7-bit request
2823
2824 // free eventually allocated BigBuf memory
2825 BigBuf_free();
2826
2827 // C(red) A(yellow) B(green)
2828 LEDsoff();
2829 // init trace buffer
2830 clear_trace();
2831 set_tracing(TRUE);
2832
2833 // The command (reader -> tag) that we're receiving.
2834 // The length of a received command will in most cases be no more than 18 bytes.
2835 // So 32 should be enough!
2836 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
2837 uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE];
2838 // The response (tag -> reader) that we're receiving.
2839 uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE];
2840 uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE];
2841
2842 // allocate the DMA buffer, used to stream samples from the FPGA
2843 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
2844 uint8_t *data = dmaBuf;
2845 uint8_t previous_data = 0;
2846 int maxDataLen = 0;
2847 int dataLen = 0;
2848 bool ReaderIsActive = FALSE;
2849 bool TagIsActive = FALSE;
2850
2851 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
2852
2853 // Set up the demodulator for tag -> reader responses.
2854 DemodInit(receivedResponse, receivedResponsePar);
2855
2856 // Set up the demodulator for the reader -> tag commands
2857 UartInit(receivedCmd, receivedCmdPar);
2858
2859 // Setup for the DMA.
2860 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2861
2862 LED_D_OFF();
2863
2864 // init sniffer
2865 MfSniffInit();
2866
2867 // And now we loop, receiving samples.
2868 for(uint32_t sniffCounter = 0; TRUE; ) {
2869
2870 if(BUTTON_PRESS()) {
2871 DbpString("cancelled by button");
2872 break;
2873 }
2874
2875 LED_A_ON();
2876 WDT_HIT();
2877
2878 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
2879 // check if a transaction is completed (timeout after 2000ms).
2880 // if yes, stop the DMA transfer and send what we have so far to the client
2881 if (MfSniffSend(2000)) {
2882 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
2883 sniffCounter = 0;
2884 data = dmaBuf;
2885 maxDataLen = 0;
2886 ReaderIsActive = FALSE;
2887 TagIsActive = FALSE;
2888 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2889 }
2890 }
2891
2892 int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
2893 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
2894 if (readBufDataP <= dmaBufDataP){ // we are processing the same block of data which is currently being transferred
2895 dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
2896 } else {
2897 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
2898 }
2899 // test for length of buffer
2900 if(dataLen > maxDataLen) { // we are more behind than ever...
2901 maxDataLen = dataLen;
2902 if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
2903 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
2904 break;
2905 }
2906 }
2907 if(dataLen < 1) continue;
2908
2909 // primary buffer was stopped ( <-- we lost data!
2910 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
2911 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
2912 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
2913 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
2914 }
2915 // secondary buffer sets as primary, secondary buffer was stopped
2916 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
2917 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
2918 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
2919 }
2920
2921 LED_A_OFF();
2922
2923 if (sniffCounter & 0x01) {
2924
2925 if(!TagIsActive) { // no need to try decoding tag data if the reader is sending
2926 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
2927 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
2928 LED_C_INV();
2929 if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
2930
2931 /* And ready to receive another command. */
2932 //UartInit(receivedCmd, receivedCmdPar);
2933 UartReset();
2934
2935 /* And also reset the demod code */
2936 DemodReset();
2937 }
2938 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
2939 }
2940
2941 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending
2942 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
2943 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
2944 LED_C_INV();
2945
2946 if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
2947
2948 // And ready to receive another response.
2949 DemodReset();
2950
2951 // And reset the Miller decoder including its (now outdated) input buffer
2952 UartInit(receivedCmd, receivedCmdPar);
2953 }
2954 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
2955 }
2956 }
2957
2958 previous_data = *data;
2959 sniffCounter++;
2960 data++;
2961 if(data == dmaBuf + DMA_BUFFER_SIZE) {
2962 data = dmaBuf;
2963 }
2964
2965 } // main cycle
2966
2967 DbpString("COMMAND FINISHED");
2968
2969 FpgaDisableSscDma();
2970 MfSniffEnd();
2971
2972 Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
2973 LEDsoff();
2974 }
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