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iclass refactor/cleanup
[proxmark3-svn] / armsrc / iso14443a.c
1 //-----------------------------------------------------------------------------
2 // Merlok - June 2011, 2012
3 // Gerhard de Koning Gans - May 2008
4 // Hagen Fritsch - June 2010
5 //
6 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
7 // at your option, any later version. See the LICENSE.txt file for the text of
8 // the license.
9 //-----------------------------------------------------------------------------
10 // Routines to support ISO 14443 type A.
11 //-----------------------------------------------------------------------------
12
13 #include "proxmark3.h"
14 #include "apps.h"
15 #include "util.h"
16 #include "string.h"
17 #include "cmd.h"
18
19 #include "iso14443crc.h"
20 #include "iso14443a.h"
21 #include "crapto1.h"
22 #include "mifareutil.h"
23 #include "BigBuf.h"
24 static uint32_t iso14a_timeout;
25 int rsamples = 0;
26 uint8_t trigger = 0;
27 // the block number for the ISO14443-4 PCB
28 static uint8_t iso14_pcb_blocknum = 0;
29
30 //
31 // ISO14443 timing:
32 //
33 // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
34 #define REQUEST_GUARD_TIME (7000/16 + 1)
35 // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
36 #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
37 // bool LastCommandWasRequest = FALSE;
38
39 //
40 // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
41 //
42 // When the PM acts as reader and is receiving tag data, it takes
43 // 3 ticks delay in the AD converter
44 // 16 ticks until the modulation detector completes and sets curbit
45 // 8 ticks until bit_to_arm is assigned from curbit
46 // 8*16 ticks for the transfer from FPGA to ARM
47 // 4*16 ticks until we measure the time
48 // - 8*16 ticks because we measure the time of the previous transfer
49 #define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
50
51 // When the PM acts as a reader and is sending, it takes
52 // 4*16 ticks until we can write data to the sending hold register
53 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
54 // 8 ticks until the first transfer starts
55 // 8 ticks later the FPGA samples the data
56 // 1 tick to assign mod_sig_coil
57 #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
58
59 // When the PM acts as tag and is receiving it takes
60 // 2 ticks delay in the RF part (for the first falling edge),
61 // 3 ticks for the A/D conversion,
62 // 8 ticks on average until the start of the SSC transfer,
63 // 8 ticks until the SSC samples the first data
64 // 7*16 ticks to complete the transfer from FPGA to ARM
65 // 8 ticks until the next ssp_clk rising edge
66 // 4*16 ticks until we measure the time
67 // - 8*16 ticks because we measure the time of the previous transfer
68 #define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
69
70 // The FPGA will report its internal sending delay in
71 uint16_t FpgaSendQueueDelay;
72 // the 5 first bits are the number of bits buffered in mod_sig_buf
73 // the last three bits are the remaining ticks/2 after the mod_sig_buf shift
74 #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
75
76 // When the PM acts as tag and is sending, it takes
77 // 4*16 ticks until we can write data to the sending hold register
78 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
79 // 8 ticks until the first transfer starts
80 // 8 ticks later the FPGA samples the data
81 // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
82 // + 1 tick to assign mod_sig_coil
83 #define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
84
85 // When the PM acts as sniffer and is receiving tag data, it takes
86 // 3 ticks A/D conversion
87 // 14 ticks to complete the modulation detection
88 // 8 ticks (on average) until the result is stored in to_arm
89 // + the delays in transferring data - which is the same for
90 // sniffing reader and tag data and therefore not relevant
91 #define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
92
93 // When the PM acts as sniffer and is receiving reader data, it takes
94 // 2 ticks delay in analogue RF receiver (for the falling edge of the
95 // start bit, which marks the start of the communication)
96 // 3 ticks A/D conversion
97 // 8 ticks on average until the data is stored in to_arm.
98 // + the delays in transferring data - which is the same for
99 // sniffing reader and tag data and therefore not relevant
100 #define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
101
102 //variables used for timing purposes:
103 //these are in ssp_clk cycles:
104 static uint32_t NextTransferTime;
105 static uint32_t LastTimeProxToAirStart;
106 static uint32_t LastProxToAirDuration;
107
108
109
110 // CARD TO READER - manchester
111 // Sequence D: 11110000 modulation with subcarrier during first half
112 // Sequence E: 00001111 modulation with subcarrier during second half
113 // Sequence F: 00000000 no modulation with subcarrier
114 // READER TO CARD - miller
115 // Sequence X: 00001100 drop after half a period
116 // Sequence Y: 00000000 no drop
117 // Sequence Z: 11000000 drop at start
118 #define SEC_D 0xf0
119 #define SEC_E 0x0f
120 #define SEC_F 0x00
121 #define SEC_X 0x0c
122 #define SEC_Y 0x00
123 #define SEC_Z 0xc0
124
125 const uint8_t OddByteParity[256] = {
126 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
127 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
128 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
129 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
130 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
131 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
132 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
133 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
134 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
135 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
136 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
137 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
138 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
139 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
140 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
141 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1
142 };
143
144
145 void iso14a_set_trigger(bool enable) {
146 trigger = enable;
147 }
148
149
150 void iso14a_set_timeout(uint32_t timeout) {
151 iso14a_timeout = timeout;
152 if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
153 }
154
155
156 void iso14a_set_ATS_timeout(uint8_t *ats) {
157
158 uint8_t tb1;
159 uint8_t fwi;
160 uint32_t fwt;
161
162 if (ats[0] > 1) { // there is a format byte T0
163 if ((ats[1] & 0x20) == 0x20) { // there is an interface byte TB(1)
164 if ((ats[1] & 0x10) == 0x10) { // there is an interface byte TA(1) preceding TB(1)
165 tb1 = ats[3];
166 } else {
167 tb1 = ats[2];
168 }
169 fwi = (tb1 & 0xf0) >> 4; // frame waiting indicator (FWI)
170 fwt = 256 * 16 * (1 << fwi); // frame waiting time (FWT) in 1/fc
171
172 iso14a_set_timeout(fwt/(8*16));
173 }
174 }
175 }
176
177
178 //-----------------------------------------------------------------------------
179 // Generate the parity value for a byte sequence
180 //
181 //-----------------------------------------------------------------------------
182 byte_t oddparity (const byte_t bt)
183 {
184 return OddByteParity[bt];
185 }
186
187 void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par)
188 {
189 uint16_t paritybit_cnt = 0;
190 uint16_t paritybyte_cnt = 0;
191 uint8_t parityBits = 0;
192
193 for (uint16_t i = 0; i < iLen; i++) {
194 // Generate the parity bits
195 parityBits |= ((OddByteParity[pbtCmd[i]]) << (7-paritybit_cnt));
196 if (paritybit_cnt == 7) {
197 par[paritybyte_cnt] = parityBits; // save 8 Bits parity
198 parityBits = 0; // and advance to next Parity Byte
199 paritybyte_cnt++;
200 paritybit_cnt = 0;
201 } else {
202 paritybit_cnt++;
203 }
204 }
205
206 // save remaining parity bits
207 par[paritybyte_cnt] = parityBits;
208
209 }
210
211 void AppendCrc14443a(uint8_t* data, int len)
212 {
213 ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
214 }
215
216 //=============================================================================
217 // ISO 14443 Type A - Miller decoder
218 //=============================================================================
219 // Basics:
220 // This decoder is used when the PM3 acts as a tag.
221 // The reader will generate "pauses" by temporarily switching of the field.
222 // At the PM3 antenna we will therefore measure a modulated antenna voltage.
223 // The FPGA does a comparison with a threshold and would deliver e.g.:
224 // ........ 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 .......
225 // The Miller decoder needs to identify the following sequences:
226 // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0")
227 // 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information")
228 // 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1")
229 // Note 1: the bitstream may start at any time. We therefore need to sync.
230 // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
231 //-----------------------------------------------------------------------------
232 static tUart Uart;
233
234 // Lookup-Table to decide if 4 raw bits are a modulation.
235 // We accept two or three consecutive "0" in any position with the rest "1"
236 const bool Mod_Miller_LUT[] = {
237 TRUE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, FALSE,
238 TRUE, TRUE, FALSE, FALSE, TRUE, FALSE, FALSE, FALSE
239 };
240 #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x00F0) >> 4])
241 #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x000F)])
242
243 void UartReset()
244 {
245 Uart.state = STATE_UNSYNCD;
246 Uart.bitCount = 0;
247 Uart.len = 0; // number of decoded data bytes
248 Uart.parityLen = 0; // number of decoded parity bytes
249 Uart.shiftReg = 0; // shiftreg to hold decoded data bits
250 Uart.parityBits = 0; // holds 8 parity bits
251 Uart.twoBits = 0x0000; // buffer for 2 Bits
252 Uart.highCnt = 0;
253 Uart.startTime = 0;
254 Uart.endTime = 0;
255 }
256
257 void UartInit(uint8_t *data, uint8_t *parity)
258 {
259 Uart.output = data;
260 Uart.parity = parity;
261 UartReset();
262 }
263
264 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
265 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
266 {
267
268 Uart.twoBits = (Uart.twoBits << 8) | bit;
269
270 if (Uart.state == STATE_UNSYNCD) { // not yet synced
271
272 if (Uart.highCnt < 2) { // wait for a stable unmodulated signal
273 if (Uart.twoBits == 0xffff) {
274 Uart.highCnt++;
275 } else {
276 Uart.highCnt = 0;
277 }
278 } else {
279 Uart.syncBit = 0xFFFF; // not set
280 // we look for a ...1111111100x11111xxxxxx pattern (the start bit)
281 if ((Uart.twoBits & 0xDF00) == 0x1F00) Uart.syncBit = 8; // mask is 11x11111 xxxxxxxx,
282 // check for 00x11111 xxxxxxxx
283 else if ((Uart.twoBits & 0xEF80) == 0x8F80) Uart.syncBit = 7; // both masks shifted right one bit, left padded with '1'
284 else if ((Uart.twoBits & 0xF7C0) == 0xC7C0) Uart.syncBit = 6; // ...
285 else if ((Uart.twoBits & 0xFBE0) == 0xE3E0) Uart.syncBit = 5;
286 else if ((Uart.twoBits & 0xFDF0) == 0xF1F0) Uart.syncBit = 4;
287 else if ((Uart.twoBits & 0xFEF8) == 0xF8F8) Uart.syncBit = 3;
288 else if ((Uart.twoBits & 0xFF7C) == 0xFC7C) Uart.syncBit = 2;
289 else if ((Uart.twoBits & 0xFFBE) == 0xFE3E) Uart.syncBit = 1;
290 if (Uart.syncBit != 0xFFFF) { // found a sync bit
291 Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
292 Uart.startTime -= Uart.syncBit;
293 Uart.endTime = Uart.startTime;
294 Uart.state = STATE_START_OF_COMMUNICATION;
295 }
296 }
297
298 } else {
299
300 if (IsMillerModulationNibble1(Uart.twoBits >> Uart.syncBit)) {
301 if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation in both halves - error
302 UartReset();
303 } else { // Modulation in first half = Sequence Z = logic "0"
304 if (Uart.state == STATE_MILLER_X) { // error - must not follow after X
305 UartReset();
306 } else {
307 Uart.bitCount++;
308 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
309 Uart.state = STATE_MILLER_Z;
310 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
311 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
312 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
313 Uart.parityBits <<= 1; // make room for the parity bit
314 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
315 Uart.bitCount = 0;
316 Uart.shiftReg = 0;
317 if((Uart.len&0x0007) == 0) { // every 8 data bytes
318 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
319 Uart.parityBits = 0;
320 }
321 }
322 }
323 }
324 } else {
325 if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1"
326 Uart.bitCount++;
327 Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg
328 Uart.state = STATE_MILLER_X;
329 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
330 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
331 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
332 Uart.parityBits <<= 1; // make room for the new parity bit
333 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
334 Uart.bitCount = 0;
335 Uart.shiftReg = 0;
336 if ((Uart.len&0x0007) == 0) { // every 8 data bytes
337 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
338 Uart.parityBits = 0;
339 }
340 }
341 } else { // no modulation in both halves - Sequence Y
342 if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication
343 Uart.state = STATE_UNSYNCD;
344 Uart.bitCount--; // last "0" was part of EOC sequence
345 Uart.shiftReg <<= 1; // drop it
346 if(Uart.bitCount > 0) { // if we decoded some bits
347 Uart.shiftReg >>= (9 - Uart.bitCount); // right align them
348 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); // add last byte to the output
349 Uart.parityBits <<= 1; // add a (void) parity bit
350 Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align parity bits
351 Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store it
352 return TRUE;
353 } else if (Uart.len & 0x0007) { // there are some parity bits to store
354 Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align remaining parity bits
355 Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store them
356 }
357 if (Uart.len) {
358 return TRUE; // we are finished with decoding the raw data sequence
359 } else {
360 UartReset(); // Nothing received - start over
361 Uart.highCnt = 1;
362 }
363 }
364 if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC
365 UartReset();
366 Uart.highCnt = 1;
367 } else { // a logic "0"
368 Uart.bitCount++;
369 Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
370 Uart.state = STATE_MILLER_Y;
371 if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
372 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
373 Uart.parityBits <<= 1; // make room for the parity bit
374 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
375 Uart.bitCount = 0;
376 Uart.shiftReg = 0;
377 if ((Uart.len&0x0007) == 0) { // every 8 data bytes
378 Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
379 Uart.parityBits = 0;
380 }
381 }
382 }
383 }
384 }
385
386 }
387
388 return FALSE; // not finished yet, need more data
389 }
390
391
392
393 //=============================================================================
394 // ISO 14443 Type A - Manchester decoder
395 //=============================================================================
396 // Basics:
397 // This decoder is used when the PM3 acts as a reader.
398 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
399 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
400 // ........ 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 .......
401 // The Manchester decoder needs to identify the following sequences:
402 // 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication")
403 // 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0
404 // 8 ticks unmodulated: Sequence F = end of communication
405 // 8 ticks modulated: A collision. Save the collision position and treat as Sequence D
406 // Note 1: the bitstream may start at any time. We therefore need to sync.
407 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
408 static tDemod Demod;
409
410 // Lookup-Table to decide if 4 raw bits are a modulation.
411 // We accept three or four "1" in any position
412 const bool Mod_Manchester_LUT[] = {
413 FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
414 FALSE, FALSE, FALSE, TRUE, FALSE, TRUE, TRUE, TRUE
415 };
416
417 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
418 #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
419
420
421 void DemodReset()
422 {
423 Demod.state = DEMOD_UNSYNCD;
424 Demod.len = 0; // number of decoded data bytes
425 Demod.parityLen = 0;
426 Demod.shiftReg = 0; // shiftreg to hold decoded data bits
427 Demod.parityBits = 0; //
428 Demod.collisionPos = 0; // Position of collision bit
429 Demod.twoBits = 0xffff; // buffer for 2 Bits
430 Demod.highCnt = 0;
431 Demod.startTime = 0;
432 Demod.endTime = 0;
433 }
434
435 void DemodInit(uint8_t *data, uint8_t *parity)
436 {
437 Demod.output = data;
438 Demod.parity = parity;
439 DemodReset();
440 }
441
442 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
443 static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
444 {
445
446 Demod.twoBits = (Demod.twoBits << 8) | bit;
447
448 if (Demod.state == DEMOD_UNSYNCD) {
449
450 if (Demod.highCnt < 2) { // wait for a stable unmodulated signal
451 if (Demod.twoBits == 0x0000) {
452 Demod.highCnt++;
453 } else {
454 Demod.highCnt = 0;
455 }
456 } else {
457 Demod.syncBit = 0xFFFF; // not set
458 if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
459 else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
460 else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
461 else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
462 else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
463 else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
464 else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
465 else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
466 if (Demod.syncBit != 0xFFFF) {
467 Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
468 Demod.startTime -= Demod.syncBit;
469 Demod.bitCount = offset; // number of decoded data bits
470 Demod.state = DEMOD_MANCHESTER_DATA;
471 }
472 }
473
474 } else {
475
476 if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half
477 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... and in second half = collision
478 if (!Demod.collisionPos) {
479 Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
480 }
481 } // modulation in first half only - Sequence D = 1
482 Demod.bitCount++;
483 Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg
484 if(Demod.bitCount == 9) { // if we decoded a full byte (including parity)
485 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
486 Demod.parityBits <<= 1; // make room for the parity bit
487 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
488 Demod.bitCount = 0;
489 Demod.shiftReg = 0;
490 if((Demod.len&0x0007) == 0) { // every 8 data bytes
491 Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits
492 Demod.parityBits = 0;
493 }
494 }
495 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
496 } else { // no modulation in first half
497 if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // and modulation in second half = Sequence E = 0
498 Demod.bitCount++;
499 Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg
500 if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity)
501 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
502 Demod.parityBits <<= 1; // make room for the new parity bit
503 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
504 Demod.bitCount = 0;
505 Demod.shiftReg = 0;
506 if ((Demod.len&0x0007) == 0) { // every 8 data bytes
507 Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits1
508 Demod.parityBits = 0;
509 }
510 }
511 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
512 } else { // no modulation in both halves - End of communication
513 if(Demod.bitCount > 0) { // there are some remaining data bits
514 Demod.shiftReg >>= (9 - Demod.bitCount); // right align the decoded bits
515 Demod.output[Demod.len++] = Demod.shiftReg & 0xff; // and add them to the output
516 Demod.parityBits <<= 1; // add a (void) parity bit
517 Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
518 Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
519 return TRUE;
520 } else if (Demod.len & 0x0007) { // there are some parity bits to store
521 Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
522 Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
523 }
524 if (Demod.len) {
525 return TRUE; // we are finished with decoding the raw data sequence
526 } else { // nothing received. Start over
527 DemodReset();
528 }
529 }
530 }
531
532 }
533
534 return FALSE; // not finished yet, need more data
535 }
536
537 //=============================================================================
538 // Finally, a `sniffer' for ISO 14443 Type A
539 // Both sides of communication!
540 //=============================================================================
541
542 //-----------------------------------------------------------------------------
543 // Record the sequence of commands sent by the reader to the tag, with
544 // triggering so that we start recording at the point that the tag is moved
545 // near the reader.
546 //-----------------------------------------------------------------------------
547 void RAMFUNC SnoopIso14443a(uint8_t param) {
548 // param:
549 // bit 0 - trigger from first card answer
550 // bit 1 - trigger from first reader 7-bit request
551
552 LEDsoff();
553
554 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
555
556 // Allocate memory from BigBuf for some buffers
557 // free all previous allocations first
558 BigBuf_free();
559
560 // The command (reader -> tag) that we're receiving.
561 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
562 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
563
564 // The response (tag -> reader) that we're receiving.
565 uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
566 uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE);
567
568 // The DMA buffer, used to stream samples from the FPGA
569 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
570
571 // init trace buffer
572 clear_trace();
573 set_tracing(TRUE);
574
575 uint8_t *data = dmaBuf;
576 uint8_t previous_data = 0;
577 int maxDataLen = 0;
578 int dataLen = 0;
579 bool TagIsActive = FALSE;
580 bool ReaderIsActive = FALSE;
581
582 // Set up the demodulator for tag -> reader responses.
583 DemodInit(receivedResponse, receivedResponsePar);
584
585 // Set up the demodulator for the reader -> tag commands
586 UartInit(receivedCmd, receivedCmdPar);
587
588 // Setup and start DMA.
589 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
590
591 // We won't start recording the frames that we acquire until we trigger;
592 // a good trigger condition to get started is probably when we see a
593 // response from the tag.
594 // triggered == FALSE -- to wait first for card
595 bool triggered = !(param & 0x03);
596
597 // And now we loop, receiving samples.
598 for(uint32_t rsamples = 0; TRUE; ) {
599
600 if(BUTTON_PRESS()) {
601 DbpString("cancelled by button");
602 break;
603 }
604
605 LED_A_ON();
606 WDT_HIT();
607
608 int register readBufDataP = data - dmaBuf;
609 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
610 if (readBufDataP <= dmaBufDataP){
611 dataLen = dmaBufDataP - readBufDataP;
612 } else {
613 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
614 }
615 // test for length of buffer
616 if(dataLen > maxDataLen) {
617 maxDataLen = dataLen;
618 if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
619 Dbprintf("blew circular buffer! dataLen=%d", dataLen);
620 break;
621 }
622 }
623 if(dataLen < 1) continue;
624
625 // primary buffer was stopped( <-- we lost data!
626 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
627 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
628 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
629 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
630 }
631 // secondary buffer sets as primary, secondary buffer was stopped
632 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
633 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
634 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
635 }
636
637 LED_A_OFF();
638
639 if (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder
640
641 if(!TagIsActive) { // no need to try decoding reader data if the tag is sending
642 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
643 if (MillerDecoding(readerdata, (rsamples-1)*4)) {
644 LED_C_ON();
645
646 // check - if there is a short 7bit request from reader
647 if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
648
649 if(triggered) {
650 if (!LogTrace(receivedCmd,
651 Uart.len,
652 Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
653 Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
654 Uart.parity,
655 TRUE)) break;
656 }
657 /* And ready to receive another command. */
658 UartReset();
659 /* And also reset the demod code, which might have been */
660 /* false-triggered by the commands from the reader. */
661 DemodReset();
662 LED_B_OFF();
663 }
664 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
665 }
666
667 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time
668 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
669 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
670 LED_B_ON();
671
672 if (!LogTrace(receivedResponse,
673 Demod.len,
674 Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
675 Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
676 Demod.parity,
677 FALSE)) break;
678
679 if ((!triggered) && (param & 0x01)) triggered = TRUE;
680
681 // And ready to receive another response.
682 DemodReset();
683 LED_C_OFF();
684 }
685 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
686 }
687 }
688
689 previous_data = *data;
690 rsamples++;
691 data++;
692 if(data == dmaBuf + DMA_BUFFER_SIZE) {
693 data = dmaBuf;
694 }
695 } // main cycle
696
697 DbpString("COMMAND FINISHED");
698
699 FpgaDisableSscDma();
700 Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
701 Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
702 LEDsoff();
703 }
704
705 //-----------------------------------------------------------------------------
706 // Prepare tag messages
707 //-----------------------------------------------------------------------------
708 static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity)
709 {
710 ToSendReset();
711
712 // Correction bit, might be removed when not needed
713 ToSendStuffBit(0);
714 ToSendStuffBit(0);
715 ToSendStuffBit(0);
716 ToSendStuffBit(0);
717 ToSendStuffBit(1); // 1
718 ToSendStuffBit(0);
719 ToSendStuffBit(0);
720 ToSendStuffBit(0);
721
722 // Send startbit
723 ToSend[++ToSendMax] = SEC_D;
724 LastProxToAirDuration = 8 * ToSendMax - 4;
725
726 for(uint16_t i = 0; i < len; i++) {
727 uint8_t b = cmd[i];
728
729 // Data bits
730 for(uint16_t j = 0; j < 8; j++) {
731 if(b & 1) {
732 ToSend[++ToSendMax] = SEC_D;
733 } else {
734 ToSend[++ToSendMax] = SEC_E;
735 }
736 b >>= 1;
737 }
738
739 // Get the parity bit
740 if (parity[i>>3] & (0x80>>(i&0x0007))) {
741 ToSend[++ToSendMax] = SEC_D;
742 LastProxToAirDuration = 8 * ToSendMax - 4;
743 } else {
744 ToSend[++ToSendMax] = SEC_E;
745 LastProxToAirDuration = 8 * ToSendMax;
746 }
747 }
748
749 // Send stopbit
750 ToSend[++ToSendMax] = SEC_F;
751
752 // Convert from last byte pos to length
753 ToSendMax++;
754 }
755
756 static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len)
757 {
758 uint8_t par[MAX_PARITY_SIZE];
759
760 GetParity(cmd, len, par);
761 CodeIso14443aAsTagPar(cmd, len, par);
762 }
763
764
765 static void Code4bitAnswerAsTag(uint8_t cmd)
766 {
767 int i;
768
769 ToSendReset();
770
771 // Correction bit, might be removed when not needed
772 ToSendStuffBit(0);
773 ToSendStuffBit(0);
774 ToSendStuffBit(0);
775 ToSendStuffBit(0);
776 ToSendStuffBit(1); // 1
777 ToSendStuffBit(0);
778 ToSendStuffBit(0);
779 ToSendStuffBit(0);
780
781 // Send startbit
782 ToSend[++ToSendMax] = SEC_D;
783
784 uint8_t b = cmd;
785 for(i = 0; i < 4; i++) {
786 if(b & 1) {
787 ToSend[++ToSendMax] = SEC_D;
788 LastProxToAirDuration = 8 * ToSendMax - 4;
789 } else {
790 ToSend[++ToSendMax] = SEC_E;
791 LastProxToAirDuration = 8 * ToSendMax;
792 }
793 b >>= 1;
794 }
795
796 // Send stopbit
797 ToSend[++ToSendMax] = SEC_F;
798
799 // Convert from last byte pos to length
800 ToSendMax++;
801 }
802
803 //-----------------------------------------------------------------------------
804 // Wait for commands from reader
805 // Stop when button is pressed
806 // Or return TRUE when command is captured
807 //-----------------------------------------------------------------------------
808 static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len)
809 {
810 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
811 // only, since we are receiving, not transmitting).
812 // Signal field is off with the appropriate LED
813 LED_D_OFF();
814 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
815
816 // Now run a `software UART' on the stream of incoming samples.
817 UartInit(received, parity);
818
819 // clear RXRDY:
820 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
821
822 for(;;) {
823 WDT_HIT();
824
825 if(BUTTON_PRESS()) return FALSE;
826
827 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
828 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
829 if(MillerDecoding(b, 0)) {
830 *len = Uart.len;
831 return TRUE;
832 }
833 }
834 }
835 }
836
837 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
838 int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
839 int EmSend4bit(uint8_t resp);
840 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par);
841 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
842 int EmSendCmd(uint8_t *resp, uint16_t respLen);
843 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par);
844 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
845 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity);
846
847 static uint8_t* free_buffer_pointer;
848
849 typedef struct {
850 uint8_t* response;
851 size_t response_n;
852 uint8_t* modulation;
853 size_t modulation_n;
854 uint32_t ProxToAirDuration;
855 } tag_response_info_t;
856
857 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
858 // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
859 // This will need the following byte array for a modulation sequence
860 // 144 data bits (18 * 8)
861 // 18 parity bits
862 // 2 Start and stop
863 // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA)
864 // 1 just for the case
865 // ----------- +
866 // 166 bytes, since every bit that needs to be send costs us a byte
867 //
868
869
870 // Prepare the tag modulation bits from the message
871 CodeIso14443aAsTag(response_info->response,response_info->response_n);
872
873 // Make sure we do not exceed the free buffer space
874 if (ToSendMax > max_buffer_size) {
875 Dbprintf("Out of memory, when modulating bits for tag answer:");
876 Dbhexdump(response_info->response_n,response_info->response,false);
877 return false;
878 }
879
880 // Copy the byte array, used for this modulation to the buffer position
881 memcpy(response_info->modulation,ToSend,ToSendMax);
882
883 // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
884 response_info->modulation_n = ToSendMax;
885 response_info->ProxToAirDuration = LastProxToAirDuration;
886
887 return true;
888 }
889
890
891 // "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit.
892 // Coded responses need one byte per bit to transfer (data, parity, start, stop, correction)
893 // 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits
894 // -> need 273 bytes buffer
895 #define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 273
896
897 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
898 // Retrieve and store the current buffer index
899 response_info->modulation = free_buffer_pointer;
900
901 // Determine the maximum size we can use from our buffer
902 size_t max_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE;
903
904 // Forward the prepare tag modulation function to the inner function
905 if (prepare_tag_modulation(response_info, max_buffer_size)) {
906 // Update the free buffer offset
907 free_buffer_pointer += ToSendMax;
908 return true;
909 } else {
910 return false;
911 }
912 }
913
914 //-----------------------------------------------------------------------------
915 // Main loop of simulated tag: receive commands from reader, decide what
916 // response to send, and send it.
917 //-----------------------------------------------------------------------------
918 void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
919 {
920 uint8_t sak;
921
922 // The first response contains the ATQA (note: bytes are transmitted in reverse order).
923 uint8_t response1[2];
924
925 switch (tagType) {
926 case 1: { // MIFARE Classic
927 // Says: I am Mifare 1k - original line
928 response1[0] = 0x04;
929 response1[1] = 0x00;
930 sak = 0x08;
931 } break;
932 case 2: { // MIFARE Ultralight
933 // Says: I am a stupid memory tag, no crypto
934 response1[0] = 0x04;
935 response1[1] = 0x00;
936 sak = 0x00;
937 } break;
938 case 3: { // MIFARE DESFire
939 // Says: I am a DESFire tag, ph33r me
940 response1[0] = 0x04;
941 response1[1] = 0x03;
942 sak = 0x20;
943 } break;
944 case 4: { // ISO/IEC 14443-4
945 // Says: I am a javacard (JCOP)
946 response1[0] = 0x04;
947 response1[1] = 0x00;
948 sak = 0x28;
949 } break;
950 case 5: { // MIFARE TNP3XXX
951 // Says: I am a toy
952 response1[0] = 0x01;
953 response1[1] = 0x0f;
954 sak = 0x01;
955 } break;
956 default: {
957 Dbprintf("Error: unkown tagtype (%d)",tagType);
958 return;
959 } break;
960 }
961
962 // The second response contains the (mandatory) first 24 bits of the UID
963 uint8_t response2[5] = {0x00};
964
965 // Check if the uid uses the (optional) part
966 uint8_t response2a[5] = {0x00};
967
968 if (uid_2nd) {
969 response2[0] = 0x88;
970 num_to_bytes(uid_1st,3,response2+1);
971 num_to_bytes(uid_2nd,4,response2a);
972 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
973
974 // Configure the ATQA and SAK accordingly
975 response1[0] |= 0x40;
976 sak |= 0x04;
977 } else {
978 num_to_bytes(uid_1st,4,response2);
979 // Configure the ATQA and SAK accordingly
980 response1[0] &= 0xBF;
981 sak &= 0xFB;
982 }
983
984 // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
985 response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
986
987 // Prepare the mandatory SAK (for 4 and 7 byte UID)
988 uint8_t response3[3] = {0x00};
989 response3[0] = sak;
990 ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
991
992 // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
993 uint8_t response3a[3] = {0x00};
994 response3a[0] = sak & 0xFB;
995 ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
996
997 uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
998 uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS:
999 // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
1000 // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
1001 // 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)
1002 // TC(1) = 0x02: CID supported, NAD not supported
1003 ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
1004
1005 #define TAG_RESPONSE_COUNT 7
1006 tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
1007 { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type
1008 { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid
1009 { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked
1010 { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1
1011 { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2
1012 { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce)
1013 { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS
1014 };
1015
1016 // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
1017 // Such a response is less time critical, so we can prepare them on the fly
1018 #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
1019 #define DYNAMIC_MODULATION_BUFFER_SIZE 512
1020 uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
1021 uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
1022 tag_response_info_t dynamic_response_info = {
1023 .response = dynamic_response_buffer,
1024 .response_n = 0,
1025 .modulation = dynamic_modulation_buffer,
1026 .modulation_n = 0
1027 };
1028
1029 // We need to listen to the high-frequency, peak-detected path.
1030 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1031
1032 BigBuf_free_keep_EM();
1033
1034 // allocate buffers:
1035 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
1036 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
1037 free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
1038
1039 // clear trace
1040 clear_trace();
1041 set_tracing(TRUE);
1042
1043 // Prepare the responses of the anticollision phase
1044 // there will be not enough time to do this at the moment the reader sends it REQA
1045 for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
1046 prepare_allocated_tag_modulation(&responses[i]);
1047 }
1048
1049 int len = 0;
1050
1051 // To control where we are in the protocol
1052 int order = 0;
1053 int lastorder;
1054
1055 // Just to allow some checks
1056 int happened = 0;
1057 int happened2 = 0;
1058 int cmdsRecvd = 0;
1059
1060 cmdsRecvd = 0;
1061 tag_response_info_t* p_response;
1062
1063 LED_A_ON();
1064 for(;;) {
1065 // Clean receive command buffer
1066
1067 if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
1068 DbpString("Button press");
1069 break;
1070 }
1071
1072 p_response = NULL;
1073
1074 // Okay, look at the command now.
1075 lastorder = order;
1076 if(receivedCmd[0] == 0x26) { // Received a REQUEST
1077 p_response = &responses[0]; order = 1;
1078 } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
1079 p_response = &responses[0]; order = 6;
1080 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // Received request for UID (cascade 1)
1081 p_response = &responses[1]; order = 2;
1082 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2)
1083 p_response = &responses[2]; order = 20;
1084 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) { // Received a SELECT (cascade 1)
1085 p_response = &responses[3]; order = 3;
1086 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) { // Received a SELECT (cascade 2)
1087 p_response = &responses[4]; order = 30;
1088 } else if(receivedCmd[0] == 0x30) { // Received a (plain) READ
1089 EmSendCmdEx(data+(4*receivedCmd[1]),16,false);
1090 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1091 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1092 p_response = NULL;
1093 } else if(receivedCmd[0] == 0x50) { // Received a HALT
1094
1095 if (tracing) {
1096 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1097 }
1098 p_response = NULL;
1099 } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) { // Received an authentication request
1100 p_response = &responses[5]; order = 7;
1101 } else if(receivedCmd[0] == 0xE0) { // Received a RATS request
1102 if (tagType == 1 || tagType == 2) { // RATS not supported
1103 EmSend4bit(CARD_NACK_NA);
1104 p_response = NULL;
1105 } else {
1106 p_response = &responses[6]; order = 70;
1107 }
1108 } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
1109 if (tracing) {
1110 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1111 }
1112 uint32_t nr = bytes_to_num(receivedCmd,4);
1113 uint32_t ar = bytes_to_num(receivedCmd+4,4);
1114 Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar);
1115 } else {
1116 // Check for ISO 14443A-4 compliant commands, look at left nibble
1117 switch (receivedCmd[0]) {
1118
1119 case 0x0B:
1120 case 0x0A: { // IBlock (command)
1121 dynamic_response_info.response[0] = receivedCmd[0];
1122 dynamic_response_info.response[1] = 0x00;
1123 dynamic_response_info.response[2] = 0x90;
1124 dynamic_response_info.response[3] = 0x00;
1125 dynamic_response_info.response_n = 4;
1126 } break;
1127
1128 case 0x1A:
1129 case 0x1B: { // Chaining command
1130 dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1131 dynamic_response_info.response_n = 2;
1132 } break;
1133
1134 case 0xaa:
1135 case 0xbb: {
1136 dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1137 dynamic_response_info.response_n = 2;
1138 } break;
1139
1140 case 0xBA: { //
1141 memcpy(dynamic_response_info.response,"\xAB\x00",2);
1142 dynamic_response_info.response_n = 2;
1143 } break;
1144
1145 case 0xCA:
1146 case 0xC2: { // Readers sends deselect command
1147 memcpy(dynamic_response_info.response,"\xCA\x00",2);
1148 dynamic_response_info.response_n = 2;
1149 } break;
1150
1151 default: {
1152 // Never seen this command before
1153 if (tracing) {
1154 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1155 }
1156 Dbprintf("Received unknown command (len=%d):",len);
1157 Dbhexdump(len,receivedCmd,false);
1158 // Do not respond
1159 dynamic_response_info.response_n = 0;
1160 } break;
1161 }
1162
1163 if (dynamic_response_info.response_n > 0) {
1164 // Copy the CID from the reader query
1165 dynamic_response_info.response[1] = receivedCmd[1];
1166
1167 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1168 AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
1169 dynamic_response_info.response_n += 2;
1170
1171 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1172 Dbprintf("Error preparing tag response");
1173 if (tracing) {
1174 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1175 }
1176 break;
1177 }
1178 p_response = &dynamic_response_info;
1179 }
1180 }
1181
1182 // Count number of wakeups received after a halt
1183 if(order == 6 && lastorder == 5) { happened++; }
1184
1185 // Count number of other messages after a halt
1186 if(order != 6 && lastorder == 5) { happened2++; }
1187
1188 if(cmdsRecvd > 999) {
1189 DbpString("1000 commands later...");
1190 break;
1191 }
1192 cmdsRecvd++;
1193
1194 if (p_response != NULL) {
1195 EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1196 // do the tracing for the previous reader request and this tag answer:
1197 uint8_t par[MAX_PARITY_SIZE];
1198 GetParity(p_response->response, p_response->response_n, par);
1199
1200 EmLogTrace(Uart.output,
1201 Uart.len,
1202 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1203 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1204 Uart.parity,
1205 p_response->response,
1206 p_response->response_n,
1207 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1208 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1209 par);
1210 }
1211
1212 if (!tracing) {
1213 Dbprintf("Trace Full. Simulation stopped.");
1214 break;
1215 }
1216 }
1217
1218 Dbprintf("%x %x %x", happened, happened2, cmdsRecvd);
1219 LED_A_OFF();
1220 BigBuf_free_keep_EM();
1221 }
1222
1223
1224 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1225 // of bits specified in the delay parameter.
1226 void PrepareDelayedTransfer(uint16_t delay)
1227 {
1228 uint8_t bitmask = 0;
1229 uint8_t bits_to_shift = 0;
1230 uint8_t bits_shifted = 0;
1231
1232 delay &= 0x07;
1233 if (delay) {
1234 for (uint16_t i = 0; i < delay; i++) {
1235 bitmask |= (0x01 << i);
1236 }
1237 ToSend[ToSendMax++] = 0x00;
1238 for (uint16_t i = 0; i < ToSendMax; i++) {
1239 bits_to_shift = ToSend[i] & bitmask;
1240 ToSend[i] = ToSend[i] >> delay;
1241 ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1242 bits_shifted = bits_to_shift;
1243 }
1244 }
1245 }
1246
1247
1248 //-------------------------------------------------------------------------------------
1249 // Transmit the command (to the tag) that was placed in ToSend[].
1250 // Parameter timing:
1251 // if NULL: transfer at next possible time, taking into account
1252 // request guard time and frame delay time
1253 // if == 0: transfer immediately and return time of transfer
1254 // if != 0: delay transfer until time specified
1255 //-------------------------------------------------------------------------------------
1256 static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing)
1257 {
1258
1259 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1260
1261 uint32_t ThisTransferTime = 0;
1262
1263 if (timing) {
1264 if(*timing == 0) { // Measure time
1265 *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1266 } else {
1267 PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
1268 }
1269 if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
1270 while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
1271 LastTimeProxToAirStart = *timing;
1272 } else {
1273 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1274 while(GetCountSspClk() < ThisTransferTime);
1275 LastTimeProxToAirStart = ThisTransferTime;
1276 }
1277
1278 // clear TXRDY
1279 AT91C_BASE_SSC->SSC_THR = SEC_Y;
1280
1281 uint16_t c = 0;
1282 for(;;) {
1283 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1284 AT91C_BASE_SSC->SSC_THR = cmd[c];
1285 c++;
1286 if(c >= len) {
1287 break;
1288 }
1289 }
1290 }
1291
1292 NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1293 }
1294
1295
1296 //-----------------------------------------------------------------------------
1297 // Prepare reader command (in bits, support short frames) to send to FPGA
1298 //-----------------------------------------------------------------------------
1299 void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity)
1300 {
1301 int i, j;
1302 int last;
1303 uint8_t b;
1304
1305 ToSendReset();
1306
1307 // Start of Communication (Seq. Z)
1308 ToSend[++ToSendMax] = SEC_Z;
1309 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1310 last = 0;
1311
1312 size_t bytecount = nbytes(bits);
1313 // Generate send structure for the data bits
1314 for (i = 0; i < bytecount; i++) {
1315 // Get the current byte to send
1316 b = cmd[i];
1317 size_t bitsleft = MIN((bits-(i*8)),8);
1318
1319 for (j = 0; j < bitsleft; j++) {
1320 if (b & 1) {
1321 // Sequence X
1322 ToSend[++ToSendMax] = SEC_X;
1323 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1324 last = 1;
1325 } else {
1326 if (last == 0) {
1327 // Sequence Z
1328 ToSend[++ToSendMax] = SEC_Z;
1329 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1330 } else {
1331 // Sequence Y
1332 ToSend[++ToSendMax] = SEC_Y;
1333 last = 0;
1334 }
1335 }
1336 b >>= 1;
1337 }
1338
1339 // Only transmit parity bit if we transmitted a complete byte
1340 if (j == 8) {
1341 // Get the parity bit
1342 if (parity[i>>3] & (0x80 >> (i&0x0007))) {
1343 // Sequence X
1344 ToSend[++ToSendMax] = SEC_X;
1345 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1346 last = 1;
1347 } else {
1348 if (last == 0) {
1349 // Sequence Z
1350 ToSend[++ToSendMax] = SEC_Z;
1351 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1352 } else {
1353 // Sequence Y
1354 ToSend[++ToSendMax] = SEC_Y;
1355 last = 0;
1356 }
1357 }
1358 }
1359 }
1360
1361 // End of Communication: Logic 0 followed by Sequence Y
1362 if (last == 0) {
1363 // Sequence Z
1364 ToSend[++ToSendMax] = SEC_Z;
1365 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1366 } else {
1367 // Sequence Y
1368 ToSend[++ToSendMax] = SEC_Y;
1369 last = 0;
1370 }
1371 ToSend[++ToSendMax] = SEC_Y;
1372
1373 // Convert to length of command:
1374 ToSendMax++;
1375 }
1376
1377 //-----------------------------------------------------------------------------
1378 // Prepare reader command to send to FPGA
1379 //-----------------------------------------------------------------------------
1380 void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity)
1381 {
1382 CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
1383 }
1384
1385
1386 //-----------------------------------------------------------------------------
1387 // Wait for commands from reader
1388 // Stop when button is pressed (return 1) or field was gone (return 2)
1389 // Or return 0 when command is captured
1390 //-----------------------------------------------------------------------------
1391 static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity)
1392 {
1393 *len = 0;
1394
1395 uint32_t timer = 0, vtime = 0;
1396 int analogCnt = 0;
1397 int analogAVG = 0;
1398
1399 // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1400 // only, since we are receiving, not transmitting).
1401 // Signal field is off with the appropriate LED
1402 LED_D_OFF();
1403 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1404
1405 // Set ADC to read field strength
1406 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1407 AT91C_BASE_ADC->ADC_MR =
1408 ADC_MODE_PRESCALE(63) |
1409 ADC_MODE_STARTUP_TIME(1) |
1410 ADC_MODE_SAMPLE_HOLD_TIME(15);
1411 AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1412 // start ADC
1413 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1414
1415 // Now run a 'software UART' on the stream of incoming samples.
1416 UartInit(received, parity);
1417
1418 // Clear RXRDY:
1419 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1420
1421 for(;;) {
1422 WDT_HIT();
1423
1424 if (BUTTON_PRESS()) return 1;
1425
1426 // test if the field exists
1427 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1428 analogCnt++;
1429 analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1430 AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1431 if (analogCnt >= 32) {
1432 if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1433 vtime = GetTickCount();
1434 if (!timer) timer = vtime;
1435 // 50ms no field --> card to idle state
1436 if (vtime - timer > 50) return 2;
1437 } else
1438 if (timer) timer = 0;
1439 analogCnt = 0;
1440 analogAVG = 0;
1441 }
1442 }
1443
1444 // receive and test the miller decoding
1445 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1446 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1447 if(MillerDecoding(b, 0)) {
1448 *len = Uart.len;
1449 return 0;
1450 }
1451 }
1452
1453 }
1454 }
1455
1456
1457 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded)
1458 {
1459 uint8_t b;
1460 uint16_t i = 0;
1461 uint32_t ThisTransferTime;
1462
1463 // Modulate Manchester
1464 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1465
1466 // include correction bit if necessary
1467 if (Uart.parityBits & 0x01) {
1468 correctionNeeded = TRUE;
1469 }
1470 if(correctionNeeded) {
1471 // 1236, so correction bit needed
1472 i = 0;
1473 } else {
1474 i = 1;
1475 }
1476
1477 // clear receiving shift register and holding register
1478 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1479 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1480 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1481 b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1482
1483 // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1484 for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never
1485 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1486 if (AT91C_BASE_SSC->SSC_RHR) break;
1487 }
1488
1489 while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1490
1491 // Clear TXRDY:
1492 AT91C_BASE_SSC->SSC_THR = SEC_F;
1493
1494 // send cycle
1495 for(; i < respLen; ) {
1496 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1497 AT91C_BASE_SSC->SSC_THR = resp[i++];
1498 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1499 }
1500
1501 if(BUTTON_PRESS()) {
1502 break;
1503 }
1504 }
1505
1506 // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1507 uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3;
1508 for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
1509 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1510 AT91C_BASE_SSC->SSC_THR = SEC_F;
1511 FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1512 i++;
1513 }
1514 }
1515
1516 LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
1517
1518 return 0;
1519 }
1520
1521 int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
1522 Code4bitAnswerAsTag(resp);
1523 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1524 // do the tracing for the previous reader request and this tag answer:
1525 uint8_t par[1];
1526 GetParity(&resp, 1, par);
1527 EmLogTrace(Uart.output,
1528 Uart.len,
1529 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1530 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1531 Uart.parity,
1532 &resp,
1533 1,
1534 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1535 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1536 par);
1537 return res;
1538 }
1539
1540 int EmSend4bit(uint8_t resp){
1541 return EmSend4bitEx(resp, false);
1542 }
1543
1544 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){
1545 CodeIso14443aAsTagPar(resp, respLen, par);
1546 int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1547 // do the tracing for the previous reader request and this tag answer:
1548 EmLogTrace(Uart.output,
1549 Uart.len,
1550 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1551 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1552 Uart.parity,
1553 resp,
1554 respLen,
1555 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1556 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1557 par);
1558 return res;
1559 }
1560
1561 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){
1562 uint8_t par[MAX_PARITY_SIZE];
1563 GetParity(resp, respLen, par);
1564 return EmSendCmdExPar(resp, respLen, correctionNeeded, par);
1565 }
1566
1567 int EmSendCmd(uint8_t *resp, uint16_t respLen){
1568 uint8_t par[MAX_PARITY_SIZE];
1569 GetParity(resp, respLen, par);
1570 return EmSendCmdExPar(resp, respLen, false, par);
1571 }
1572
1573 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
1574 return EmSendCmdExPar(resp, respLen, false, par);
1575 }
1576
1577 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
1578 uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity)
1579 {
1580 if (tracing) {
1581 // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1582 // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1583 // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1584 uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1585 uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1586 uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1587 reader_EndTime = tag_StartTime - exact_fdt;
1588 reader_StartTime = reader_EndTime - reader_modlen;
1589 if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE)) {
1590 return FALSE;
1591 } else return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
1592 } else {
1593 return TRUE;
1594 }
1595 }
1596
1597 //-----------------------------------------------------------------------------
1598 // Wait a certain time for tag response
1599 // If a response is captured return TRUE
1600 // If it takes too long return FALSE
1601 //-----------------------------------------------------------------------------
1602 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset)
1603 {
1604 uint32_t c;
1605
1606 // Set FPGA mode to "reader listen mode", no modulation (listen
1607 // only, since we are receiving, not transmitting).
1608 // Signal field is on with the appropriate LED
1609 LED_D_ON();
1610 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1611
1612 // Now get the answer from the card
1613 DemodInit(receivedResponse, receivedResponsePar);
1614
1615 // clear RXRDY:
1616 uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1617
1618 c = 0;
1619 for(;;) {
1620 WDT_HIT();
1621
1622 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1623 b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1624 if(ManchesterDecoding(b, offset, 0)) {
1625 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1626 return TRUE;
1627 } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
1628 return FALSE;
1629 }
1630 }
1631 }
1632 }
1633
1634 void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing)
1635 {
1636 CodeIso14443aBitsAsReaderPar(frame, bits, par);
1637
1638 // Send command to tag
1639 TransmitFor14443a(ToSend, ToSendMax, timing);
1640 if(trigger)
1641 LED_A_ON();
1642
1643 // Log reader command in trace buffer
1644 if (tracing) {
1645 LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
1646 }
1647 }
1648
1649 void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing)
1650 {
1651 ReaderTransmitBitsPar(frame, len*8, par, timing);
1652 }
1653
1654 void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing)
1655 {
1656 // Generate parity and redirect
1657 uint8_t par[MAX_PARITY_SIZE];
1658 GetParity(frame, len/8, par);
1659 ReaderTransmitBitsPar(frame, len, par, timing);
1660 }
1661
1662 void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing)
1663 {
1664 // Generate parity and redirect
1665 uint8_t par[MAX_PARITY_SIZE];
1666 GetParity(frame, len, par);
1667 ReaderTransmitBitsPar(frame, len*8, par, timing);
1668 }
1669
1670 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity)
1671 {
1672 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset)) return FALSE;
1673 if (tracing) {
1674 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1675 }
1676 return Demod.len;
1677 }
1678
1679 int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
1680 {
1681 if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0)) return FALSE;
1682 if (tracing) {
1683 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1684 }
1685 return Demod.len;
1686 }
1687
1688 /* performs iso14443a anticollision procedure
1689 * fills the uid pointer unless NULL
1690 * fills resp_data unless NULL */
1691 int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr) {
1692 uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP
1693 uint8_t sel_all[] = { 0x93,0x20 };
1694 uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1695 uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1696 uint8_t resp[MAX_FRAME_SIZE]; // theoretically. A usual RATS will be much smaller
1697 uint8_t resp_par[MAX_PARITY_SIZE];
1698 byte_t uid_resp[4];
1699 size_t uid_resp_len;
1700
1701 uint8_t sak = 0x04; // cascade uid
1702 int cascade_level = 0;
1703 int len;
1704
1705 // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1706 ReaderTransmitBitsPar(wupa,7,0, NULL);
1707
1708 // Receive the ATQA
1709 if(!ReaderReceive(resp, resp_par)) return 0;
1710
1711 if(p_hi14a_card) {
1712 memcpy(p_hi14a_card->atqa, resp, 2);
1713 p_hi14a_card->uidlen = 0;
1714 memset(p_hi14a_card->uid,0,10);
1715 }
1716
1717 // clear uid
1718 if (uid_ptr) {
1719 memset(uid_ptr,0,10);
1720 }
1721
1722 // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1723 // which case we need to make a cascade 2 request and select - this is a long UID
1724 // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1725 for(; sak & 0x04; cascade_level++) {
1726 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1727 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1728
1729 // SELECT_ALL
1730 ReaderTransmit(sel_all, sizeof(sel_all), NULL);
1731 if (!ReaderReceive(resp, resp_par)) return 0;
1732
1733 if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit
1734 memset(uid_resp, 0, 4);
1735 uint16_t uid_resp_bits = 0;
1736 uint16_t collision_answer_offset = 0;
1737 // anti-collision-loop:
1738 while (Demod.collisionPos) {
1739 Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1740 for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point
1741 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1742 uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8);
1743 }
1744 uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position
1745 uid_resp_bits++;
1746 // construct anticollosion command:
1747 sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits
1748 for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1749 sel_uid[2+i] = uid_resp[i];
1750 }
1751 collision_answer_offset = uid_resp_bits%8;
1752 ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1753 if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0;
1754 }
1755 // finally, add the last bits and BCC of the UID
1756 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1757 uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1758 uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1759 }
1760
1761 } else { // no collision, use the response to SELECT_ALL as current uid
1762 memcpy(uid_resp, resp, 4);
1763 }
1764 uid_resp_len = 4;
1765
1766 // calculate crypto UID. Always use last 4 Bytes.
1767 if(cuid_ptr) {
1768 *cuid_ptr = bytes_to_num(uid_resp, 4);
1769 }
1770
1771 // Construct SELECT UID command
1772 sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1773 memcpy(sel_uid+2, uid_resp, 4); // the UID
1774 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC
1775 AppendCrc14443a(sel_uid, 7); // calculate and add CRC
1776 ReaderTransmit(sel_uid, sizeof(sel_uid), NULL);
1777
1778 // Receive the SAK
1779 if (!ReaderReceive(resp, resp_par)) return 0;
1780 sak = resp[0];
1781
1782 // Test if more parts of the uid are coming
1783 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
1784 // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
1785 // http://www.nxp.com/documents/application_note/AN10927.pdf
1786 uid_resp[0] = uid_resp[1];
1787 uid_resp[1] = uid_resp[2];
1788 uid_resp[2] = uid_resp[3];
1789
1790 uid_resp_len = 3;
1791 }
1792
1793 if(uid_ptr) {
1794 memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
1795 }
1796
1797 if(p_hi14a_card) {
1798 memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
1799 p_hi14a_card->uidlen += uid_resp_len;
1800 }
1801 }
1802
1803 if(p_hi14a_card) {
1804 p_hi14a_card->sak = sak;
1805 p_hi14a_card->ats_len = 0;
1806 }
1807
1808 // non iso14443a compliant tag
1809 if( (sak & 0x20) == 0) return 2;
1810
1811 // Request for answer to select
1812 AppendCrc14443a(rats, 2);
1813 ReaderTransmit(rats, sizeof(rats), NULL);
1814
1815 if (!(len = ReaderReceive(resp, resp_par))) return 0;
1816
1817
1818 if(p_hi14a_card) {
1819 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
1820 p_hi14a_card->ats_len = len;
1821 }
1822
1823 // reset the PCB block number
1824 iso14_pcb_blocknum = 0;
1825
1826 // set default timeout based on ATS
1827 iso14a_set_ATS_timeout(resp);
1828
1829 return 1;
1830 }
1831
1832 void iso14443a_setup(uint8_t fpga_minor_mode) {
1833 FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1834 // Set up the synchronous serial port
1835 FpgaSetupSsc();
1836 // connect Demodulated Signal to ADC:
1837 SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1838
1839 // Signal field is on with the appropriate LED
1840 if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
1841 || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
1842 LED_D_ON();
1843 } else {
1844 LED_D_OFF();
1845 }
1846 FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
1847
1848 // Start the timer
1849 StartCountSspClk();
1850
1851 DemodReset();
1852 UartReset();
1853 NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
1854 iso14a_set_timeout(1050); // 10ms default
1855 }
1856
1857 int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
1858 uint8_t parity[MAX_PARITY_SIZE];
1859 uint8_t real_cmd[cmd_len+4];
1860 real_cmd[0] = 0x0a; //I-Block
1861 // put block number into the PCB
1862 real_cmd[0] |= iso14_pcb_blocknum;
1863 real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
1864 memcpy(real_cmd+2, cmd, cmd_len);
1865 AppendCrc14443a(real_cmd,cmd_len+2);
1866
1867 ReaderTransmit(real_cmd, cmd_len+4, NULL);
1868 size_t len = ReaderReceive(data, parity);
1869 uint8_t *data_bytes = (uint8_t *) data;
1870 if (!len)
1871 return 0; //DATA LINK ERROR
1872 // if we received an I- or R(ACK)-Block with a block number equal to the
1873 // current block number, toggle the current block number
1874 else if (len >= 4 // PCB+CID+CRC = 4 bytes
1875 && ((data_bytes[0] & 0xC0) == 0 // I-Block
1876 || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
1877 && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
1878 {
1879 iso14_pcb_blocknum ^= 1;
1880 }
1881
1882 return len;
1883 }
1884
1885 //-----------------------------------------------------------------------------
1886 // Read an ISO 14443a tag. Send out commands and store answers.
1887 //
1888 //-----------------------------------------------------------------------------
1889 void ReaderIso14443a(UsbCommand *c)
1890 {
1891 iso14a_command_t param = c->arg[0];
1892 uint8_t *cmd = c->d.asBytes;
1893 size_t len = c->arg[1] & 0xffff;
1894 size_t lenbits = c->arg[1] >> 16;
1895 uint32_t timeout = c->arg[2];
1896 uint32_t arg0 = 0;
1897 byte_t buf[USB_CMD_DATA_SIZE];
1898 uint8_t par[MAX_PARITY_SIZE];
1899
1900 if(param & ISO14A_CONNECT) {
1901 clear_trace();
1902 }
1903
1904 set_tracing(TRUE);
1905
1906 if(param & ISO14A_REQUEST_TRIGGER) {
1907 iso14a_set_trigger(TRUE);
1908 }
1909
1910 if(param & ISO14A_CONNECT) {
1911 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
1912 if(!(param & ISO14A_NO_SELECT)) {
1913 iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
1914 arg0 = iso14443a_select_card(NULL,card,NULL);
1915 cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
1916 }
1917 }
1918
1919 if(param & ISO14A_SET_TIMEOUT) {
1920 iso14a_set_timeout(timeout);
1921 }
1922
1923 if(param & ISO14A_APDU) {
1924 arg0 = iso14_apdu(cmd, len, buf);
1925 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
1926 }
1927
1928 if(param & ISO14A_RAW) {
1929 if(param & ISO14A_APPEND_CRC) {
1930 AppendCrc14443a(cmd,len);
1931 len += 2;
1932 if (lenbits) lenbits += 16;
1933 }
1934 if(lenbits>0) {
1935 GetParity(cmd, lenbits/8, par);
1936 ReaderTransmitBitsPar(cmd, lenbits, par, NULL);
1937 } else {
1938 ReaderTransmit(cmd,len, NULL);
1939 }
1940 arg0 = ReaderReceive(buf, par);
1941 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
1942 }
1943
1944 if(param & ISO14A_REQUEST_TRIGGER) {
1945 iso14a_set_trigger(FALSE);
1946 }
1947
1948 if(param & ISO14A_NO_DISCONNECT) {
1949 return;
1950 }
1951
1952 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1953 LEDsoff();
1954 }
1955
1956
1957 // Determine the distance between two nonces.
1958 // Assume that the difference is small, but we don't know which is first.
1959 // Therefore try in alternating directions.
1960 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
1961
1962 uint16_t i;
1963 uint32_t nttmp1, nttmp2;
1964
1965 if (nt1 == nt2) return 0;
1966
1967 nttmp1 = nt1;
1968 nttmp2 = nt2;
1969
1970 for (i = 1; i < 32768; i++) {
1971 nttmp1 = prng_successor(nttmp1, 1);
1972 if (nttmp1 == nt2) return i;
1973 nttmp2 = prng_successor(nttmp2, 1);
1974 if (nttmp2 == nt1) return -i;
1975 }
1976
1977 return(-99999); // either nt1 or nt2 are invalid nonces
1978 }
1979
1980
1981 //-----------------------------------------------------------------------------
1982 // Recover several bits of the cypher stream. This implements (first stages of)
1983 // the algorithm described in "The Dark Side of Security by Obscurity and
1984 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
1985 // (article by Nicolas T. Courtois, 2009)
1986 //-----------------------------------------------------------------------------
1987 void ReaderMifare(bool first_try)
1988 {
1989 // Mifare AUTH
1990 uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b };
1991 uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
1992 static uint8_t mf_nr_ar3;
1993
1994 uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE];
1995 uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE];
1996
1997 if (first_try) {
1998 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
1999 }
2000
2001 // free eventually allocated BigBuf memory. We want all for tracing.
2002 BigBuf_free();
2003
2004 clear_trace();
2005 set_tracing(TRUE);
2006
2007 byte_t nt_diff = 0;
2008 uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
2009 static byte_t par_low = 0;
2010 bool led_on = TRUE;
2011 uint8_t uid[10] ={0};
2012 uint32_t cuid;
2013
2014 uint32_t nt = 0;
2015 uint32_t previous_nt = 0;
2016 static uint32_t nt_attacked = 0;
2017 byte_t par_list[8] = {0x00};
2018 byte_t ks_list[8] = {0x00};
2019
2020 static uint32_t sync_time;
2021 static uint32_t sync_cycles;
2022 int catch_up_cycles = 0;
2023 int last_catch_up = 0;
2024 uint16_t consecutive_resyncs = 0;
2025 int isOK = 0;
2026
2027 if (first_try) {
2028 mf_nr_ar3 = 0;
2029 sync_time = GetCountSspClk() & 0xfffffff8;
2030 sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
2031 nt_attacked = 0;
2032 nt = 0;
2033 par[0] = 0;
2034 }
2035 else {
2036 // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
2037 mf_nr_ar3++;
2038 mf_nr_ar[3] = mf_nr_ar3;
2039 par[0] = par_low;
2040 }
2041
2042 LED_A_ON();
2043 LED_B_OFF();
2044 LED_C_OFF();
2045
2046
2047 #define DARKSIDE_MAX_TRIES 32 // number of tries to sync on PRNG cycle. Then give up.
2048 uint16_t unsuccessfull_tries = 0;
2049
2050 for(uint16_t i = 0; TRUE; i++) {
2051
2052 LED_C_ON();
2053 WDT_HIT();
2054
2055 // Test if the action was cancelled
2056 if(BUTTON_PRESS()) {
2057 isOK = -1;
2058 break;
2059 }
2060
2061 if(!iso14443a_select_card(uid, NULL, &cuid)) {
2062 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
2063 continue;
2064 }
2065
2066 sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
2067 catch_up_cycles = 0;
2068
2069 // if we missed the sync time already, advance to the next nonce repeat
2070 while(GetCountSspClk() > sync_time) {
2071 sync_time = (sync_time & 0xfffffff8) + sync_cycles;
2072 }
2073
2074 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2075 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2076
2077 // Receive the (4 Byte) "random" nonce
2078 if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2079 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce");
2080 continue;
2081 }
2082
2083 previous_nt = nt;
2084 nt = bytes_to_num(receivedAnswer, 4);
2085
2086 // Transmit reader nonce with fake par
2087 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2088
2089 if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
2090 int nt_distance = dist_nt(previous_nt, nt);
2091 if (nt_distance == 0) {
2092 nt_attacked = nt;
2093 }
2094 else {
2095 if (nt_distance == -99999) { // invalid nonce received
2096 unsuccessfull_tries++;
2097 if (!nt_attacked && unsuccessfull_tries > DARKSIDE_MAX_TRIES) {
2098 isOK = -3; // Card has an unpredictable PRNG. Give up
2099 break;
2100 } else {
2101 continue; // continue trying...
2102 }
2103 }
2104 sync_cycles = (sync_cycles - nt_distance);
2105 if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
2106 continue;
2107 }
2108 }
2109
2110 if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
2111 catch_up_cycles = -dist_nt(nt_attacked, nt);
2112 if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one.
2113 catch_up_cycles = 0;
2114 continue;
2115 }
2116 if (catch_up_cycles == last_catch_up) {
2117 consecutive_resyncs++;
2118 }
2119 else {
2120 last_catch_up = catch_up_cycles;
2121 consecutive_resyncs = 0;
2122 }
2123 if (consecutive_resyncs < 3) {
2124 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);
2125 }
2126 else {
2127 sync_cycles = sync_cycles + catch_up_cycles;
2128 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);
2129 }
2130 continue;
2131 }
2132
2133 consecutive_resyncs = 0;
2134
2135 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2136 if (ReaderReceive(receivedAnswer, receivedAnswerPar))
2137 {
2138 catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2139
2140 if (nt_diff == 0)
2141 {
2142 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
2143 }
2144
2145 led_on = !led_on;
2146 if(led_on) LED_B_ON(); else LED_B_OFF();
2147
2148 par_list[nt_diff] = SwapBits(par[0], 8);
2149 ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
2150
2151 // Test if the information is complete
2152 if (nt_diff == 0x07) {
2153 isOK = 1;
2154 break;
2155 }
2156
2157 nt_diff = (nt_diff + 1) & 0x07;
2158 mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2159 par[0] = par_low;
2160 } else {
2161 if (nt_diff == 0 && first_try)
2162 {
2163 par[0]++;
2164 if (par[0] == 0x00) { // tried all 256 possible parities without success. Card doesn't send NACK.
2165 isOK = -2;
2166 break;
2167 }
2168 } else {
2169 par[0] = ((par[0] & 0x1F) + 1) | par_low;
2170 }
2171 }
2172 }
2173
2174
2175 mf_nr_ar[3] &= 0x1F;
2176
2177 byte_t buf[28];
2178 memcpy(buf + 0, uid, 4);
2179 num_to_bytes(nt, 4, buf + 4);
2180 memcpy(buf + 8, par_list, 8);
2181 memcpy(buf + 16, ks_list, 8);
2182 memcpy(buf + 24, mf_nr_ar, 4);
2183
2184 cmd_send(CMD_ACK, isOK, 0, 0, buf, 28);
2185
2186 // Thats it...
2187 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2188 LEDsoff();
2189
2190 set_tracing(FALSE);
2191 }
2192
2193 /**
2194 *MIFARE 1K simulate.
2195 *
2196 *@param flags :
2197 * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2198 * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
2199 * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
2200 * FLAG_NR_AR_ATTACK - means we should collect NR_AR responses for bruteforcing later
2201 *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2202 */
2203 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
2204 {
2205 int cardSTATE = MFEMUL_NOFIELD;
2206 int _7BUID = 0;
2207 int vHf = 0; // in mV
2208 int res;
2209 uint32_t selTimer = 0;
2210 uint32_t authTimer = 0;
2211 uint16_t len = 0;
2212 uint8_t cardWRBL = 0;
2213 uint8_t cardAUTHSC = 0;
2214 uint8_t cardAUTHKEY = 0xff; // no authentication
2215 uint32_t cardRr = 0;
2216 uint32_t cuid = 0;
2217 //uint32_t rn_enc = 0;
2218 uint32_t ans = 0;
2219 uint32_t cardINTREG = 0;
2220 uint8_t cardINTBLOCK = 0;
2221 struct Crypto1State mpcs = {0, 0};
2222 struct Crypto1State *pcs;
2223 pcs = &mpcs;
2224 uint32_t numReads = 0;//Counts numer of times reader read a block
2225 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
2226 uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE];
2227 uint8_t response[MAX_MIFARE_FRAME_SIZE];
2228 uint8_t response_par[MAX_MIFARE_PARITY_SIZE];
2229
2230 uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
2231 uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2232 uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
2233 uint8_t rSAK[] = {0x08, 0xb6, 0xdd};
2234 uint8_t rSAK1[] = {0x04, 0xda, 0x17};
2235
2236 uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04};
2237 uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2238
2239 //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
2240 // This can be used in a reader-only attack.
2241 // (it can also be retrieved via 'hf 14a list', but hey...
2242 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
2243 uint8_t ar_nr_collected = 0;
2244
2245 // Authenticate response - nonce
2246 uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2247
2248 //-- Determine the UID
2249 // Can be set from emulator memory, incoming data
2250 // and can be 7 or 4 bytes long
2251 if (flags & FLAG_4B_UID_IN_DATA)
2252 {
2253 // 4B uid comes from data-portion of packet
2254 memcpy(rUIDBCC1,datain,4);
2255 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2256
2257 } else if (flags & FLAG_7B_UID_IN_DATA) {
2258 // 7B uid comes from data-portion of packet
2259 memcpy(&rUIDBCC1[1],datain,3);
2260 memcpy(rUIDBCC2, datain+3, 4);
2261 _7BUID = true;
2262 } else {
2263 // get UID from emul memory
2264 emlGetMemBt(receivedCmd, 7, 1);
2265 _7BUID = !(receivedCmd[0] == 0x00);
2266 if (!_7BUID) { // ---------- 4BUID
2267 emlGetMemBt(rUIDBCC1, 0, 4);
2268 } else { // ---------- 7BUID
2269 emlGetMemBt(&rUIDBCC1[1], 0, 3);
2270 emlGetMemBt(rUIDBCC2, 3, 4);
2271 }
2272 }
2273
2274 /*
2275 * Regardless of what method was used to set the UID, set fifth byte and modify
2276 * the ATQA for 4 or 7-byte UID
2277 */
2278 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2279 if (_7BUID) {
2280 rATQA[0] = 0x44;
2281 rUIDBCC1[0] = 0x88;
2282 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2283 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2284 }
2285
2286 if (MF_DBGLEVEL >= 1) {
2287 if (!_7BUID) {
2288 Dbprintf("4B UID: %02x%02x%02x%02x",
2289 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3]);
2290 } else {
2291 Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",
2292 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3],
2293 rUIDBCC2[0], rUIDBCC2[1] ,rUIDBCC2[2], rUIDBCC2[3]);
2294 }
2295 }
2296
2297 // We need to listen to the high-frequency, peak-detected path.
2298 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2299
2300 // free eventually allocated BigBuf memory but keep Emulator Memory
2301 BigBuf_free_keep_EM();
2302
2303 // clear trace
2304 clear_trace();
2305 set_tracing(TRUE);
2306
2307
2308 bool finished = FALSE;
2309 while (!BUTTON_PRESS() && !finished) {
2310 WDT_HIT();
2311
2312 // find reader field
2313 if (cardSTATE == MFEMUL_NOFIELD) {
2314 vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
2315 if (vHf > MF_MINFIELDV) {
2316 cardSTATE_TO_IDLE();
2317 LED_A_ON();
2318 }
2319 }
2320 if(cardSTATE == MFEMUL_NOFIELD) continue;
2321
2322 //Now, get data
2323
2324 res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
2325 if (res == 2) { //Field is off!
2326 cardSTATE = MFEMUL_NOFIELD;
2327 LEDsoff();
2328 continue;
2329 } else if (res == 1) {
2330 break; //return value 1 means button press
2331 }
2332
2333 // REQ or WUP request in ANY state and WUP in HALTED state
2334 if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
2335 selTimer = GetTickCount();
2336 EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
2337 cardSTATE = MFEMUL_SELECT1;
2338
2339 // init crypto block
2340 LED_B_OFF();
2341 LED_C_OFF();
2342 crypto1_destroy(pcs);
2343 cardAUTHKEY = 0xff;
2344 continue;
2345 }
2346
2347 switch (cardSTATE) {
2348 case MFEMUL_NOFIELD:
2349 case MFEMUL_HALTED:
2350 case MFEMUL_IDLE:{
2351 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2352 break;
2353 }
2354 case MFEMUL_SELECT1:{
2355 // select all
2356 if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
2357 if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received");
2358 EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2359 break;
2360 }
2361
2362 if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
2363 {
2364 Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
2365 }
2366 // select card
2367 if (len == 9 &&
2368 (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2369 EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK));
2370 cuid = bytes_to_num(rUIDBCC1, 4);
2371 if (!_7BUID) {
2372 cardSTATE = MFEMUL_WORK;
2373 LED_B_ON();
2374 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2375 break;
2376 } else {
2377 cardSTATE = MFEMUL_SELECT2;
2378 }
2379 }
2380 break;
2381 }
2382 case MFEMUL_AUTH1:{
2383 if( len != 8)
2384 {
2385 cardSTATE_TO_IDLE();
2386 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2387 break;
2388 }
2389
2390 uint32_t ar = bytes_to_num(receivedCmd, 4);
2391 uint32_t nr = bytes_to_num(&receivedCmd[4], 4);
2392
2393 //Collect AR/NR
2394 if(ar_nr_collected < 2){
2395 if(ar_nr_responses[2] != ar)
2396 {// Avoid duplicates... probably not necessary, ar should vary.
2397 ar_nr_responses[ar_nr_collected*4] = cuid;
2398 ar_nr_responses[ar_nr_collected*4+1] = nonce;
2399 ar_nr_responses[ar_nr_collected*4+2] = ar;
2400 ar_nr_responses[ar_nr_collected*4+3] = nr;
2401 ar_nr_collected++;
2402 }
2403 }
2404
2405 // --- crypto
2406 crypto1_word(pcs, ar , 1);
2407 cardRr = nr ^ crypto1_word(pcs, 0, 0);
2408
2409 // test if auth OK
2410 if (cardRr != prng_successor(nonce, 64)){
2411 if (MF_DBGLEVEL >= 2) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
2412 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2413 cardRr, prng_successor(nonce, 64));
2414 // Shouldn't we respond anything here?
2415 // Right now, we don't nack or anything, which causes the
2416 // reader to do a WUPA after a while. /Martin
2417 // -- which is the correct response. /piwi
2418 cardSTATE_TO_IDLE();
2419 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2420 break;
2421 }
2422
2423 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2424
2425 num_to_bytes(ans, 4, rAUTH_AT);
2426 // --- crypto
2427 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2428 LED_C_ON();
2429 cardSTATE = MFEMUL_WORK;
2430 if (MF_DBGLEVEL >= 4) Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2431 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2432 GetTickCount() - authTimer);
2433 break;
2434 }
2435 case MFEMUL_SELECT2:{
2436 if (!len) {
2437 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2438 break;
2439 }
2440 if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
2441 EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2442 break;
2443 }
2444
2445 // select 2 card
2446 if (len == 9 &&
2447 (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
2448 EmSendCmd(rSAK, sizeof(rSAK));
2449 cuid = bytes_to_num(rUIDBCC2, 4);
2450 cardSTATE = MFEMUL_WORK;
2451 LED_B_ON();
2452 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2453 break;
2454 }
2455
2456 // i guess there is a command). go into the work state.
2457 if (len != 4) {
2458 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2459 break;
2460 }
2461 cardSTATE = MFEMUL_WORK;
2462 //goto lbWORK;
2463 //intentional fall-through to the next case-stmt
2464 }
2465
2466 case MFEMUL_WORK:{
2467 if (len == 0) {
2468 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2469 break;
2470 }
2471
2472 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2473
2474 if(encrypted_data) {
2475 // decrypt seqence
2476 mf_crypto1_decrypt(pcs, receivedCmd, len);
2477 }
2478
2479 if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
2480 authTimer = GetTickCount();
2481 cardAUTHSC = receivedCmd[1] / 4; // received block num
2482 cardAUTHKEY = receivedCmd[0] - 0x60;
2483 crypto1_destroy(pcs);//Added by martin
2484 crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2485
2486 if (!encrypted_data) { // first authentication
2487 if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2488
2489 crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
2490 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2491 } else { // nested authentication
2492 if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2493 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2494 num_to_bytes(ans, 4, rAUTH_AT);
2495 }
2496
2497 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2498 //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
2499 cardSTATE = MFEMUL_AUTH1;
2500 break;
2501 }
2502
2503 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2504 // BUT... ACK --> NACK
2505 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2506 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2507 break;
2508 }
2509
2510 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2511 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2512 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2513 break;
2514 }
2515
2516 if(len != 4) {
2517 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2518 break;
2519 }
2520
2521 if(receivedCmd[0] == 0x30 // read block
2522 || receivedCmd[0] == 0xA0 // write block
2523 || receivedCmd[0] == 0xC0 // inc
2524 || receivedCmd[0] == 0xC1 // dec
2525 || receivedCmd[0] == 0xC2 // restore
2526 || receivedCmd[0] == 0xB0) { // transfer
2527 if (receivedCmd[1] >= 16 * 4) {
2528 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2529 if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02x) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2530 break;
2531 }
2532
2533 if (receivedCmd[1] / 4 != cardAUTHSC) {
2534 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2535 if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02x) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
2536 break;
2537 }
2538 }
2539 // read block
2540 if (receivedCmd[0] == 0x30) {
2541 if (MF_DBGLEVEL >= 4) {
2542 Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
2543 }
2544 emlGetMem(response, receivedCmd[1], 1);
2545 AppendCrc14443a(response, 16);
2546 mf_crypto1_encrypt(pcs, response, 18, response_par);
2547 EmSendCmdPar(response, 18, response_par);
2548 numReads++;
2549 if(exitAfterNReads > 0 && numReads == exitAfterNReads) {
2550 Dbprintf("%d reads done, exiting", numReads);
2551 finished = true;
2552 }
2553 break;
2554 }
2555 // write block
2556 if (receivedCmd[0] == 0xA0) {
2557 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
2558 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2559 cardSTATE = MFEMUL_WRITEBL2;
2560 cardWRBL = receivedCmd[1];
2561 break;
2562 }
2563 // increment, decrement, restore
2564 if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
2565 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2566 if (emlCheckValBl(receivedCmd[1])) {
2567 if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2568 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2569 break;
2570 }
2571 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2572 if (receivedCmd[0] == 0xC1)
2573 cardSTATE = MFEMUL_INTREG_INC;
2574 if (receivedCmd[0] == 0xC0)
2575 cardSTATE = MFEMUL_INTREG_DEC;
2576 if (receivedCmd[0] == 0xC2)
2577 cardSTATE = MFEMUL_INTREG_REST;
2578 cardWRBL = receivedCmd[1];
2579 break;
2580 }
2581 // transfer
2582 if (receivedCmd[0] == 0xB0) {
2583 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2584 if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2585 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2586 else
2587 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2588 break;
2589 }
2590 // halt
2591 if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
2592 LED_B_OFF();
2593 LED_C_OFF();
2594 cardSTATE = MFEMUL_HALTED;
2595 if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer);
2596 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2597 break;
2598 }
2599 // RATS
2600 if (receivedCmd[0] == 0xe0) {//RATS
2601 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2602 break;
2603 }
2604 // command not allowed
2605 if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking");
2606 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2607 break;
2608 }
2609 case MFEMUL_WRITEBL2:{
2610 if (len == 18){
2611 mf_crypto1_decrypt(pcs, receivedCmd, len);
2612 emlSetMem(receivedCmd, cardWRBL, 1);
2613 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2614 cardSTATE = MFEMUL_WORK;
2615 } else {
2616 cardSTATE_TO_IDLE();
2617 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2618 }
2619 break;
2620 }
2621
2622 case MFEMUL_INTREG_INC:{
2623 mf_crypto1_decrypt(pcs, receivedCmd, len);
2624 memcpy(&ans, receivedCmd, 4);
2625 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2626 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2627 cardSTATE_TO_IDLE();
2628 break;
2629 }
2630 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2631 cardINTREG = cardINTREG + ans;
2632 cardSTATE = MFEMUL_WORK;
2633 break;
2634 }
2635 case MFEMUL_INTREG_DEC:{
2636 mf_crypto1_decrypt(pcs, receivedCmd, len);
2637 memcpy(&ans, receivedCmd, 4);
2638 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2639 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2640 cardSTATE_TO_IDLE();
2641 break;
2642 }
2643 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2644 cardINTREG = cardINTREG - ans;
2645 cardSTATE = MFEMUL_WORK;
2646 break;
2647 }
2648 case MFEMUL_INTREG_REST:{
2649 mf_crypto1_decrypt(pcs, receivedCmd, len);
2650 memcpy(&ans, receivedCmd, 4);
2651 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2652 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2653 cardSTATE_TO_IDLE();
2654 break;
2655 }
2656 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2657 cardSTATE = MFEMUL_WORK;
2658 break;
2659 }
2660 }
2661 }
2662
2663 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2664 LEDsoff();
2665
2666 if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
2667 {
2668 //May just aswell send the collected ar_nr in the response aswell
2669 cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_responses,ar_nr_collected*4*4);
2670 }
2671
2672 if(flags & FLAG_NR_AR_ATTACK)
2673 {
2674 if(ar_nr_collected > 1) {
2675 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
2676 Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
2677 ar_nr_responses[0], // UID
2678 ar_nr_responses[1], //NT
2679 ar_nr_responses[2], //AR1
2680 ar_nr_responses[3], //NR1
2681 ar_nr_responses[6], //AR2
2682 ar_nr_responses[7] //NR2
2683 );
2684 } else {
2685 Dbprintf("Failed to obtain two AR/NR pairs!");
2686 if(ar_nr_collected >0) {
2687 Dbprintf("Only got these: UID=%08x, nonce=%08x, AR1=%08x, NR1=%08x",
2688 ar_nr_responses[0], // UID
2689 ar_nr_responses[1], //NT
2690 ar_nr_responses[2], //AR1
2691 ar_nr_responses[3] //NR1
2692 );
2693 }
2694 }
2695 }
2696 if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen());
2697
2698 }
2699
2700
2701
2702 //-----------------------------------------------------------------------------
2703 // MIFARE sniffer.
2704 //
2705 //-----------------------------------------------------------------------------
2706 void RAMFUNC SniffMifare(uint8_t param) {
2707 // param:
2708 // bit 0 - trigger from first card answer
2709 // bit 1 - trigger from first reader 7-bit request
2710
2711 // C(red) A(yellow) B(green)
2712 LEDsoff();
2713 // init trace buffer
2714 clear_trace();
2715 set_tracing(TRUE);
2716
2717 // The command (reader -> tag) that we're receiving.
2718 // The length of a received command will in most cases be no more than 18 bytes.
2719 // So 32 should be enough!
2720 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
2721 uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE];
2722 // The response (tag -> reader) that we're receiving.
2723 uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE];
2724 uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE];
2725
2726 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
2727
2728 // free eventually allocated BigBuf memory
2729 BigBuf_free();
2730 // allocate the DMA buffer, used to stream samples from the FPGA
2731 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
2732 uint8_t *data = dmaBuf;
2733 uint8_t previous_data = 0;
2734 int maxDataLen = 0;
2735 int dataLen = 0;
2736 bool ReaderIsActive = FALSE;
2737 bool TagIsActive = FALSE;
2738
2739 // Set up the demodulator for tag -> reader responses.
2740 DemodInit(receivedResponse, receivedResponsePar);
2741
2742 // Set up the demodulator for the reader -> tag commands
2743 UartInit(receivedCmd, receivedCmdPar);
2744
2745 // Setup for the DMA.
2746 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2747
2748 LED_D_OFF();
2749
2750 // init sniffer
2751 MfSniffInit();
2752
2753 // And now we loop, receiving samples.
2754 for(uint32_t sniffCounter = 0; TRUE; ) {
2755
2756 if(BUTTON_PRESS()) {
2757 DbpString("cancelled by button");
2758 break;
2759 }
2760
2761 LED_A_ON();
2762 WDT_HIT();
2763
2764 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
2765 // check if a transaction is completed (timeout after 2000ms).
2766 // if yes, stop the DMA transfer and send what we have so far to the client
2767 if (MfSniffSend(2000)) {
2768 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
2769 sniffCounter = 0;
2770 data = dmaBuf;
2771 maxDataLen = 0;
2772 ReaderIsActive = FALSE;
2773 TagIsActive = FALSE;
2774 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2775 }
2776 }
2777
2778 int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
2779 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
2780 if (readBufDataP <= dmaBufDataP){ // we are processing the same block of data which is currently being transferred
2781 dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
2782 } else {
2783 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
2784 }
2785 // test for length of buffer
2786 if(dataLen > maxDataLen) { // we are more behind than ever...
2787 maxDataLen = dataLen;
2788 if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
2789 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
2790 break;
2791 }
2792 }
2793 if(dataLen < 1) continue;
2794
2795 // primary buffer was stopped ( <-- we lost data!
2796 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
2797 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
2798 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
2799 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
2800 }
2801 // secondary buffer sets as primary, secondary buffer was stopped
2802 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
2803 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
2804 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
2805 }
2806
2807 LED_A_OFF();
2808
2809 if (sniffCounter & 0x01) {
2810
2811 if(!TagIsActive) { // no need to try decoding tag data if the reader is sending
2812 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
2813 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
2814 LED_C_INV();
2815 if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
2816
2817 /* And ready to receive another command. */
2818 UartReset();
2819
2820 /* And also reset the demod code */
2821 DemodReset();
2822 }
2823 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
2824 }
2825
2826 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending
2827 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
2828 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
2829 LED_C_INV();
2830
2831 if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
2832
2833 // And ready to receive another response.
2834 DemodReset();
2835 }
2836 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
2837 }
2838 }
2839
2840 previous_data = *data;
2841 sniffCounter++;
2842 data++;
2843 if(data == dmaBuf + DMA_BUFFER_SIZE) {
2844 data = dmaBuf;
2845 }
2846
2847 } // main cycle
2848
2849 DbpString("COMMAND FINISHED");
2850
2851 FpgaDisableSscDma();
2852 MfSniffEnd();
2853
2854 Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
2855 LEDsoff();
2856 }
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