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Merge pull request #125 from pwpiwi/hf_mifare_fix
[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 // We won't start recording the frames that we acquire until we trigger;
555 // a good trigger condition to get started is probably when we see a
556 // response from the tag.
557 // triggered == FALSE -- to wait first for card
558 bool triggered = !(param & 0x03);
559
560 // Allocate memory from BigBuf for some buffers
561 // free all previous allocations first
562 BigBuf_free();
563
564 // The command (reader -> tag) that we're receiving.
565 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
566 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
567
568 // The response (tag -> reader) that we're receiving.
569 uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
570 uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE);
571
572 // The DMA buffer, used to stream samples from the FPGA
573 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
574
575 // init trace buffer
576 clear_trace();
577 set_tracing(TRUE);
578
579 uint8_t *data = dmaBuf;
580 uint8_t previous_data = 0;
581 int maxDataLen = 0;
582 int dataLen = 0;
583 bool TagIsActive = FALSE;
584 bool ReaderIsActive = FALSE;
585
586 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
587
588 // Set up the demodulator for tag -> reader responses.
589 DemodInit(receivedResponse, receivedResponsePar);
590
591 // Set up the demodulator for the reader -> tag commands
592 UartInit(receivedCmd, receivedCmdPar);
593
594 // Setup and start DMA.
595 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
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 BigBuf_free_keep_EM();
1030
1031 // allocate buffers:
1032 uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
1033 uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
1034 free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
1035
1036 // clear trace
1037 clear_trace();
1038 set_tracing(TRUE);
1039
1040 // Prepare the responses of the anticollision phase
1041 // there will be not enough time to do this at the moment the reader sends it REQA
1042 for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
1043 prepare_allocated_tag_modulation(&responses[i]);
1044 }
1045
1046 int len = 0;
1047
1048 // To control where we are in the protocol
1049 int order = 0;
1050 int lastorder;
1051
1052 // Just to allow some checks
1053 int happened = 0;
1054 int happened2 = 0;
1055 int cmdsRecvd = 0;
1056
1057 // We need to listen to the high-frequency, peak-detected path.
1058 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
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 // free eventually allocated BigBuf memory. We want all for tracing.
1998 BigBuf_free();
1999
2000 clear_trace();
2001 set_tracing(TRUE);
2002
2003 byte_t nt_diff = 0;
2004 uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
2005 static byte_t par_low = 0;
2006 bool led_on = TRUE;
2007 uint8_t uid[10] ={0};
2008 uint32_t cuid;
2009
2010 uint32_t nt = 0;
2011 uint32_t previous_nt = 0;
2012 static uint32_t nt_attacked = 0;
2013 byte_t par_list[8] = {0x00};
2014 byte_t ks_list[8] = {0x00};
2015
2016 static uint32_t sync_time;
2017 static uint32_t sync_cycles;
2018 int catch_up_cycles = 0;
2019 int last_catch_up = 0;
2020 uint16_t consecutive_resyncs = 0;
2021 int isOK = 0;
2022
2023 if (first_try) {
2024 mf_nr_ar3 = 0;
2025 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2026 sync_time = GetCountSspClk() & 0xfffffff8;
2027 sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
2028 nt_attacked = 0;
2029 nt = 0;
2030 par[0] = 0;
2031 }
2032 else {
2033 // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
2034 mf_nr_ar3++;
2035 mf_nr_ar[3] = mf_nr_ar3;
2036 par[0] = par_low;
2037 }
2038
2039 LED_A_ON();
2040 LED_B_OFF();
2041 LED_C_OFF();
2042
2043
2044 #define DARKSIDE_MAX_TRIES 32 // number of tries to sync on PRNG cycle. Then give up.
2045 uint16_t unsuccessfull_tries = 0;
2046
2047 for(uint16_t i = 0; TRUE; i++) {
2048
2049 LED_C_ON();
2050 WDT_HIT();
2051
2052 // Test if the action was cancelled
2053 if(BUTTON_PRESS()) {
2054 isOK = -1;
2055 break;
2056 }
2057
2058 if(!iso14443a_select_card(uid, NULL, &cuid)) {
2059 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
2060 continue;
2061 }
2062
2063 sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
2064 catch_up_cycles = 0;
2065
2066 // if we missed the sync time already, advance to the next nonce repeat
2067 while(GetCountSspClk() > sync_time) {
2068 sync_time = (sync_time & 0xfffffff8) + sync_cycles;
2069 }
2070
2071 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2072 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2073
2074 // Receive the (4 Byte) "random" nonce
2075 if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2076 if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce");
2077 continue;
2078 }
2079
2080 previous_nt = nt;
2081 nt = bytes_to_num(receivedAnswer, 4);
2082
2083 // Transmit reader nonce with fake par
2084 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2085
2086 if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
2087 int nt_distance = dist_nt(previous_nt, nt);
2088 if (nt_distance == 0) {
2089 nt_attacked = nt;
2090 }
2091 else {
2092 if (nt_distance == -99999) { // invalid nonce received
2093 unsuccessfull_tries++;
2094 if (!nt_attacked && unsuccessfull_tries > DARKSIDE_MAX_TRIES) {
2095 isOK = -3; // Card has an unpredictable PRNG. Give up
2096 break;
2097 } else {
2098 continue; // continue trying...
2099 }
2100 }
2101 sync_cycles = (sync_cycles - nt_distance);
2102 if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
2103 continue;
2104 }
2105 }
2106
2107 if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
2108 catch_up_cycles = -dist_nt(nt_attacked, nt);
2109 if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one.
2110 catch_up_cycles = 0;
2111 continue;
2112 }
2113 if (catch_up_cycles == last_catch_up) {
2114 consecutive_resyncs++;
2115 }
2116 else {
2117 last_catch_up = catch_up_cycles;
2118 consecutive_resyncs = 0;
2119 }
2120 if (consecutive_resyncs < 3) {
2121 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);
2122 }
2123 else {
2124 sync_cycles = sync_cycles + catch_up_cycles;
2125 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);
2126 }
2127 continue;
2128 }
2129
2130 consecutive_resyncs = 0;
2131
2132 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2133 if (ReaderReceive(receivedAnswer, receivedAnswerPar))
2134 {
2135 catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2136
2137 if (nt_diff == 0)
2138 {
2139 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
2140 }
2141
2142 led_on = !led_on;
2143 if(led_on) LED_B_ON(); else LED_B_OFF();
2144
2145 par_list[nt_diff] = SwapBits(par[0], 8);
2146 ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
2147
2148 // Test if the information is complete
2149 if (nt_diff == 0x07) {
2150 isOK = 1;
2151 break;
2152 }
2153
2154 nt_diff = (nt_diff + 1) & 0x07;
2155 mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2156 par[0] = par_low;
2157 } else {
2158 if (nt_diff == 0 && first_try)
2159 {
2160 par[0]++;
2161 if (par[0] == 0x00) { // tried all 256 possible parities without success. Card doesn't send NACK.
2162 isOK = -2;
2163 break;
2164 }
2165 } else {
2166 par[0] = ((par[0] & 0x1F) + 1) | par_low;
2167 }
2168 }
2169 }
2170
2171
2172 mf_nr_ar[3] &= 0x1F;
2173
2174 byte_t buf[28];
2175 memcpy(buf + 0, uid, 4);
2176 num_to_bytes(nt, 4, buf + 4);
2177 memcpy(buf + 8, par_list, 8);
2178 memcpy(buf + 16, ks_list, 8);
2179 memcpy(buf + 24, mf_nr_ar, 4);
2180
2181 cmd_send(CMD_ACK, isOK, 0, 0, buf, 28);
2182
2183 // Thats it...
2184 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2185 LEDsoff();
2186
2187 set_tracing(FALSE);
2188 }
2189
2190 /**
2191 *MIFARE 1K simulate.
2192 *
2193 *@param flags :
2194 * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2195 * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
2196 * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
2197 * FLAG_NR_AR_ATTACK - means we should collect NR_AR responses for bruteforcing later
2198 *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2199 */
2200 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
2201 {
2202 int cardSTATE = MFEMUL_NOFIELD;
2203 int _7BUID = 0;
2204 int vHf = 0; // in mV
2205 int res;
2206 uint32_t selTimer = 0;
2207 uint32_t authTimer = 0;
2208 uint16_t len = 0;
2209 uint8_t cardWRBL = 0;
2210 uint8_t cardAUTHSC = 0;
2211 uint8_t cardAUTHKEY = 0xff; // no authentication
2212 uint32_t cardRr = 0;
2213 uint32_t cuid = 0;
2214 //uint32_t rn_enc = 0;
2215 uint32_t ans = 0;
2216 uint32_t cardINTREG = 0;
2217 uint8_t cardINTBLOCK = 0;
2218 struct Crypto1State mpcs = {0, 0};
2219 struct Crypto1State *pcs;
2220 pcs = &mpcs;
2221 uint32_t numReads = 0;//Counts numer of times reader read a block
2222 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
2223 uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE];
2224 uint8_t response[MAX_MIFARE_FRAME_SIZE];
2225 uint8_t response_par[MAX_MIFARE_PARITY_SIZE];
2226
2227 uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
2228 uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2229 uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
2230 uint8_t rSAK[] = {0x08, 0xb6, 0xdd};
2231 uint8_t rSAK1[] = {0x04, 0xda, 0x17};
2232
2233 uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04};
2234 uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2235
2236 //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
2237 // This can be used in a reader-only attack.
2238 // (it can also be retrieved via 'hf 14a list', but hey...
2239 uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
2240 uint8_t ar_nr_collected = 0;
2241
2242 // free eventually allocated BigBuf memory but keep Emulator Memory
2243 BigBuf_free_keep_EM();
2244
2245 // clear trace
2246 clear_trace();
2247 set_tracing(TRUE);
2248
2249 // Authenticate response - nonce
2250 uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2251
2252 //-- Determine the UID
2253 // Can be set from emulator memory, incoming data
2254 // and can be 7 or 4 bytes long
2255 if (flags & FLAG_4B_UID_IN_DATA)
2256 {
2257 // 4B uid comes from data-portion of packet
2258 memcpy(rUIDBCC1,datain,4);
2259 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2260
2261 } else if (flags & FLAG_7B_UID_IN_DATA) {
2262 // 7B uid comes from data-portion of packet
2263 memcpy(&rUIDBCC1[1],datain,3);
2264 memcpy(rUIDBCC2, datain+3, 4);
2265 _7BUID = true;
2266 } else {
2267 // get UID from emul memory
2268 emlGetMemBt(receivedCmd, 7, 1);
2269 _7BUID = !(receivedCmd[0] == 0x00);
2270 if (!_7BUID) { // ---------- 4BUID
2271 emlGetMemBt(rUIDBCC1, 0, 4);
2272 } else { // ---------- 7BUID
2273 emlGetMemBt(&rUIDBCC1[1], 0, 3);
2274 emlGetMemBt(rUIDBCC2, 3, 4);
2275 }
2276 }
2277
2278 /*
2279 * Regardless of what method was used to set the UID, set fifth byte and modify
2280 * the ATQA for 4 or 7-byte UID
2281 */
2282 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2283 if (_7BUID) {
2284 rATQA[0] = 0x44;
2285 rUIDBCC1[0] = 0x88;
2286 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2287 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2288 }
2289
2290 // We need to listen to the high-frequency, peak-detected path.
2291 iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2292
2293
2294 if (MF_DBGLEVEL >= 1) {
2295 if (!_7BUID) {
2296 Dbprintf("4B UID: %02x%02x%02x%02x",
2297 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3]);
2298 } else {
2299 Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",
2300 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3],
2301 rUIDBCC2[0], rUIDBCC2[1] ,rUIDBCC2[2], rUIDBCC2[3]);
2302 }
2303 }
2304
2305 bool finished = FALSE;
2306 while (!BUTTON_PRESS() && !finished) {
2307 WDT_HIT();
2308
2309 // find reader field
2310 if (cardSTATE == MFEMUL_NOFIELD) {
2311 vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
2312 if (vHf > MF_MINFIELDV) {
2313 cardSTATE_TO_IDLE();
2314 LED_A_ON();
2315 }
2316 }
2317 if(cardSTATE == MFEMUL_NOFIELD) continue;
2318
2319 //Now, get data
2320
2321 res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
2322 if (res == 2) { //Field is off!
2323 cardSTATE = MFEMUL_NOFIELD;
2324 LEDsoff();
2325 continue;
2326 } else if (res == 1) {
2327 break; //return value 1 means button press
2328 }
2329
2330 // REQ or WUP request in ANY state and WUP in HALTED state
2331 if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
2332 selTimer = GetTickCount();
2333 EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
2334 cardSTATE = MFEMUL_SELECT1;
2335
2336 // init crypto block
2337 LED_B_OFF();
2338 LED_C_OFF();
2339 crypto1_destroy(pcs);
2340 cardAUTHKEY = 0xff;
2341 continue;
2342 }
2343
2344 switch (cardSTATE) {
2345 case MFEMUL_NOFIELD:
2346 case MFEMUL_HALTED:
2347 case MFEMUL_IDLE:{
2348 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2349 break;
2350 }
2351 case MFEMUL_SELECT1:{
2352 // select all
2353 if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
2354 if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received");
2355 EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2356 break;
2357 }
2358
2359 if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
2360 {
2361 Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
2362 }
2363 // select card
2364 if (len == 9 &&
2365 (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2366 EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK));
2367 cuid = bytes_to_num(rUIDBCC1, 4);
2368 if (!_7BUID) {
2369 cardSTATE = MFEMUL_WORK;
2370 LED_B_ON();
2371 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2372 break;
2373 } else {
2374 cardSTATE = MFEMUL_SELECT2;
2375 }
2376 }
2377 break;
2378 }
2379 case MFEMUL_AUTH1:{
2380 if( len != 8)
2381 {
2382 cardSTATE_TO_IDLE();
2383 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2384 break;
2385 }
2386
2387 uint32_t ar = bytes_to_num(receivedCmd, 4);
2388 uint32_t nr = bytes_to_num(&receivedCmd[4], 4);
2389
2390 //Collect AR/NR
2391 if(ar_nr_collected < 2){
2392 if(ar_nr_responses[2] != ar)
2393 {// Avoid duplicates... probably not necessary, ar should vary.
2394 ar_nr_responses[ar_nr_collected*4] = cuid;
2395 ar_nr_responses[ar_nr_collected*4+1] = nonce;
2396 ar_nr_responses[ar_nr_collected*4+2] = ar;
2397 ar_nr_responses[ar_nr_collected*4+3] = nr;
2398 ar_nr_collected++;
2399 }
2400 }
2401
2402 // --- crypto
2403 crypto1_word(pcs, ar , 1);
2404 cardRr = nr ^ crypto1_word(pcs, 0, 0);
2405
2406 // test if auth OK
2407 if (cardRr != prng_successor(nonce, 64)){
2408 if (MF_DBGLEVEL >= 2) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
2409 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2410 cardRr, prng_successor(nonce, 64));
2411 // Shouldn't we respond anything here?
2412 // Right now, we don't nack or anything, which causes the
2413 // reader to do a WUPA after a while. /Martin
2414 // -- which is the correct response. /piwi
2415 cardSTATE_TO_IDLE();
2416 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2417 break;
2418 }
2419
2420 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2421
2422 num_to_bytes(ans, 4, rAUTH_AT);
2423 // --- crypto
2424 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2425 LED_C_ON();
2426 cardSTATE = MFEMUL_WORK;
2427 if (MF_DBGLEVEL >= 4) Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2428 cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2429 GetTickCount() - authTimer);
2430 break;
2431 }
2432 case MFEMUL_SELECT2:{
2433 if (!len) {
2434 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2435 break;
2436 }
2437 if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
2438 EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2439 break;
2440 }
2441
2442 // select 2 card
2443 if (len == 9 &&
2444 (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
2445 EmSendCmd(rSAK, sizeof(rSAK));
2446 cuid = bytes_to_num(rUIDBCC2, 4);
2447 cardSTATE = MFEMUL_WORK;
2448 LED_B_ON();
2449 if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2450 break;
2451 }
2452
2453 // i guess there is a command). go into the work state.
2454 if (len != 4) {
2455 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2456 break;
2457 }
2458 cardSTATE = MFEMUL_WORK;
2459 //goto lbWORK;
2460 //intentional fall-through to the next case-stmt
2461 }
2462
2463 case MFEMUL_WORK:{
2464 if (len == 0) {
2465 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2466 break;
2467 }
2468
2469 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2470
2471 if(encrypted_data) {
2472 // decrypt seqence
2473 mf_crypto1_decrypt(pcs, receivedCmd, len);
2474 }
2475
2476 if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
2477 authTimer = GetTickCount();
2478 cardAUTHSC = receivedCmd[1] / 4; // received block num
2479 cardAUTHKEY = receivedCmd[0] - 0x60;
2480 crypto1_destroy(pcs);//Added by martin
2481 crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2482
2483 if (!encrypted_data) { // first authentication
2484 if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2485
2486 crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
2487 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2488 } else { // nested authentication
2489 if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2490 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2491 num_to_bytes(ans, 4, rAUTH_AT);
2492 }
2493
2494 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2495 //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
2496 cardSTATE = MFEMUL_AUTH1;
2497 break;
2498 }
2499
2500 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2501 // BUT... ACK --> NACK
2502 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2503 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2504 break;
2505 }
2506
2507 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2508 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2509 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2510 break;
2511 }
2512
2513 if(len != 4) {
2514 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2515 break;
2516 }
2517
2518 if(receivedCmd[0] == 0x30 // read block
2519 || receivedCmd[0] == 0xA0 // write block
2520 || receivedCmd[0] == 0xC0 // inc
2521 || receivedCmd[0] == 0xC1 // dec
2522 || receivedCmd[0] == 0xC2 // restore
2523 || receivedCmd[0] == 0xB0) { // transfer
2524 if (receivedCmd[1] >= 16 * 4) {
2525 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2526 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]);
2527 break;
2528 }
2529
2530 if (receivedCmd[1] / 4 != cardAUTHSC) {
2531 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2532 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);
2533 break;
2534 }
2535 }
2536 // read block
2537 if (receivedCmd[0] == 0x30) {
2538 if (MF_DBGLEVEL >= 4) {
2539 Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
2540 }
2541 emlGetMem(response, receivedCmd[1], 1);
2542 AppendCrc14443a(response, 16);
2543 mf_crypto1_encrypt(pcs, response, 18, response_par);
2544 EmSendCmdPar(response, 18, response_par);
2545 numReads++;
2546 if(exitAfterNReads > 0 && numReads == exitAfterNReads) {
2547 Dbprintf("%d reads done, exiting", numReads);
2548 finished = true;
2549 }
2550 break;
2551 }
2552 // write block
2553 if (receivedCmd[0] == 0xA0) {
2554 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
2555 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2556 cardSTATE = MFEMUL_WRITEBL2;
2557 cardWRBL = receivedCmd[1];
2558 break;
2559 }
2560 // increment, decrement, restore
2561 if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
2562 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2563 if (emlCheckValBl(receivedCmd[1])) {
2564 if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2565 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2566 break;
2567 }
2568 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2569 if (receivedCmd[0] == 0xC1)
2570 cardSTATE = MFEMUL_INTREG_INC;
2571 if (receivedCmd[0] == 0xC0)
2572 cardSTATE = MFEMUL_INTREG_DEC;
2573 if (receivedCmd[0] == 0xC2)
2574 cardSTATE = MFEMUL_INTREG_REST;
2575 cardWRBL = receivedCmd[1];
2576 break;
2577 }
2578 // transfer
2579 if (receivedCmd[0] == 0xB0) {
2580 if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2581 if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2582 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2583 else
2584 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2585 break;
2586 }
2587 // halt
2588 if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
2589 LED_B_OFF();
2590 LED_C_OFF();
2591 cardSTATE = MFEMUL_HALTED;
2592 if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer);
2593 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2594 break;
2595 }
2596 // RATS
2597 if (receivedCmd[0] == 0xe0) {//RATS
2598 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2599 break;
2600 }
2601 // command not allowed
2602 if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking");
2603 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2604 break;
2605 }
2606 case MFEMUL_WRITEBL2:{
2607 if (len == 18){
2608 mf_crypto1_decrypt(pcs, receivedCmd, len);
2609 emlSetMem(receivedCmd, cardWRBL, 1);
2610 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2611 cardSTATE = MFEMUL_WORK;
2612 } else {
2613 cardSTATE_TO_IDLE();
2614 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2615 }
2616 break;
2617 }
2618
2619 case MFEMUL_INTREG_INC:{
2620 mf_crypto1_decrypt(pcs, receivedCmd, len);
2621 memcpy(&ans, receivedCmd, 4);
2622 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2623 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2624 cardSTATE_TO_IDLE();
2625 break;
2626 }
2627 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2628 cardINTREG = cardINTREG + ans;
2629 cardSTATE = MFEMUL_WORK;
2630 break;
2631 }
2632 case MFEMUL_INTREG_DEC:{
2633 mf_crypto1_decrypt(pcs, receivedCmd, len);
2634 memcpy(&ans, receivedCmd, 4);
2635 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2636 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2637 cardSTATE_TO_IDLE();
2638 break;
2639 }
2640 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2641 cardINTREG = cardINTREG - ans;
2642 cardSTATE = MFEMUL_WORK;
2643 break;
2644 }
2645 case MFEMUL_INTREG_REST:{
2646 mf_crypto1_decrypt(pcs, receivedCmd, len);
2647 memcpy(&ans, receivedCmd, 4);
2648 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2649 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2650 cardSTATE_TO_IDLE();
2651 break;
2652 }
2653 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2654 cardSTATE = MFEMUL_WORK;
2655 break;
2656 }
2657 }
2658 }
2659
2660 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2661 LEDsoff();
2662
2663 if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
2664 {
2665 //May just aswell send the collected ar_nr in the response aswell
2666 cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_responses,ar_nr_collected*4*4);
2667 }
2668
2669 if(flags & FLAG_NR_AR_ATTACK)
2670 {
2671 if(ar_nr_collected > 1) {
2672 Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
2673 Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
2674 ar_nr_responses[0], // UID
2675 ar_nr_responses[1], //NT
2676 ar_nr_responses[2], //AR1
2677 ar_nr_responses[3], //NR1
2678 ar_nr_responses[6], //AR2
2679 ar_nr_responses[7] //NR2
2680 );
2681 } else {
2682 Dbprintf("Failed to obtain two AR/NR pairs!");
2683 if(ar_nr_collected >0) {
2684 Dbprintf("Only got these: UID=%08x, nonce=%08x, AR1=%08x, NR1=%08x",
2685 ar_nr_responses[0], // UID
2686 ar_nr_responses[1], //NT
2687 ar_nr_responses[2], //AR1
2688 ar_nr_responses[3] //NR1
2689 );
2690 }
2691 }
2692 }
2693 if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen());
2694
2695 }
2696
2697
2698
2699 //-----------------------------------------------------------------------------
2700 // MIFARE sniffer.
2701 //
2702 //-----------------------------------------------------------------------------
2703 void RAMFUNC SniffMifare(uint8_t param) {
2704 // param:
2705 // bit 0 - trigger from first card answer
2706 // bit 1 - trigger from first reader 7-bit request
2707
2708 // C(red) A(yellow) B(green)
2709 LEDsoff();
2710 // init trace buffer
2711 clear_trace();
2712 set_tracing(TRUE);
2713
2714 // The command (reader -> tag) that we're receiving.
2715 // The length of a received command will in most cases be no more than 18 bytes.
2716 // So 32 should be enough!
2717 uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
2718 uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE];
2719 // The response (tag -> reader) that we're receiving.
2720 uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE];
2721 uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE];
2722
2723 // As we receive stuff, we copy it from receivedCmd or receivedResponse
2724 // into trace, along with its length and other annotations.
2725 //uint8_t *trace = (uint8_t *)BigBuf;
2726
2727 // free eventually allocated BigBuf memory
2728 BigBuf_free();
2729 // allocate the DMA buffer, used to stream samples from the FPGA
2730 uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
2731 uint8_t *data = dmaBuf;
2732 uint8_t previous_data = 0;
2733 int maxDataLen = 0;
2734 int dataLen = 0;
2735 bool ReaderIsActive = FALSE;
2736 bool TagIsActive = FALSE;
2737
2738 iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
2739
2740 // Set up the demodulator for tag -> reader responses.
2741 DemodInit(receivedResponse, receivedResponsePar);
2742
2743 // Set up the demodulator for the reader -> tag commands
2744 UartInit(receivedCmd, receivedCmdPar);
2745
2746 // Setup for the DMA.
2747 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2748
2749 LED_D_OFF();
2750
2751 // init sniffer
2752 MfSniffInit();
2753
2754 // And now we loop, receiving samples.
2755 for(uint32_t sniffCounter = 0; TRUE; ) {
2756
2757 if(BUTTON_PRESS()) {
2758 DbpString("cancelled by button");
2759 break;
2760 }
2761
2762 LED_A_ON();
2763 WDT_HIT();
2764
2765 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
2766 // check if a transaction is completed (timeout after 2000ms).
2767 // if yes, stop the DMA transfer and send what we have so far to the client
2768 if (MfSniffSend(2000)) {
2769 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
2770 sniffCounter = 0;
2771 data = dmaBuf;
2772 maxDataLen = 0;
2773 ReaderIsActive = FALSE;
2774 TagIsActive = FALSE;
2775 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
2776 }
2777 }
2778
2779 int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
2780 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
2781 if (readBufDataP <= dmaBufDataP){ // we are processing the same block of data which is currently being transferred
2782 dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
2783 } else {
2784 dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
2785 }
2786 // test for length of buffer
2787 if(dataLen > maxDataLen) { // we are more behind than ever...
2788 maxDataLen = dataLen;
2789 if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
2790 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
2791 break;
2792 }
2793 }
2794 if(dataLen < 1) continue;
2795
2796 // primary buffer was stopped ( <-- we lost data!
2797 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
2798 AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
2799 AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
2800 Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
2801 }
2802 // secondary buffer sets as primary, secondary buffer was stopped
2803 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
2804 AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
2805 AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
2806 }
2807
2808 LED_A_OFF();
2809
2810 if (sniffCounter & 0x01) {
2811
2812 if(!TagIsActive) { // no need to try decoding tag data if the reader is sending
2813 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
2814 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
2815 LED_C_INV();
2816 if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
2817
2818 /* And ready to receive another command. */
2819 UartReset();
2820
2821 /* And also reset the demod code */
2822 DemodReset();
2823 }
2824 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
2825 }
2826
2827 if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending
2828 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
2829 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
2830 LED_C_INV();
2831
2832 if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
2833
2834 // And ready to receive another response.
2835 DemodReset();
2836 }
2837 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
2838 }
2839 }
2840
2841 previous_data = *data;
2842 sniffCounter++;
2843 data++;
2844 if(data == dmaBuf + DMA_BUFFER_SIZE) {
2845 data = dmaBuf;
2846 }
2847
2848 } // main cycle
2849
2850 DbpString("COMMAND FINISHED");
2851
2852 FpgaDisableSscDma();
2853 MfSniffEnd();
2854
2855 Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
2856 LEDsoff();
2857 }
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