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1 | //----------------------------------------------------------------------------- | |
2 | // Merlok - June 2011, 2012 | |
3 | // Gerhard de Koning Gans - May 2008 | |
4 | // Hagen Fritsch - June 2010 | |
5 | // | |
6 | // This code is licensed to you under the terms of the GNU GPL, version 2 or, | |
7 | // at your option, any later version. See the LICENSE.txt file for the text of | |
8 | // the license. | |
9 | //----------------------------------------------------------------------------- | |
10 | // Routines to support ISO 14443 type A. | |
11 | //----------------------------------------------------------------------------- | |
12 | ||
13 | #include "iso14443a.h" | |
14 | ||
15 | #include <stdio.h> | |
16 | #include <string.h> | |
17 | #include "proxmark3.h" | |
18 | #include "apps.h" | |
19 | #include "util.h" | |
20 | #include "cmd.h" | |
21 | #include "iso14443crc.h" | |
22 | #include "crapto1/crapto1.h" | |
23 | #include "mifareutil.h" | |
24 | #include "mifaresniff.h" | |
25 | #include "BigBuf.h" | |
26 | #include "protocols.h" | |
27 | #include "parity.h" | |
28 | #include "fpgaloader.h" | |
29 | ||
30 | typedef struct { | |
31 | enum { | |
32 | DEMOD_UNSYNCD, | |
33 | // DEMOD_HALF_SYNCD, | |
34 | // DEMOD_MOD_FIRST_HALF, | |
35 | // DEMOD_NOMOD_FIRST_HALF, | |
36 | DEMOD_MANCHESTER_DATA | |
37 | } state; | |
38 | uint16_t twoBits; | |
39 | uint16_t highCnt; | |
40 | uint16_t bitCount; | |
41 | uint16_t collisionPos; | |
42 | uint16_t syncBit; | |
43 | uint8_t parityBits; | |
44 | uint8_t parityLen; | |
45 | uint16_t shiftReg; | |
46 | uint16_t samples; | |
47 | uint16_t len; | |
48 | uint32_t startTime, endTime; | |
49 | uint8_t *output; | |
50 | uint8_t *parity; | |
51 | } tDemod; | |
52 | ||
53 | typedef enum { | |
54 | MOD_NOMOD = 0, | |
55 | MOD_SECOND_HALF, | |
56 | MOD_FIRST_HALF, | |
57 | MOD_BOTH_HALVES | |
58 | } Modulation_t; | |
59 | ||
60 | typedef struct { | |
61 | enum { | |
62 | STATE_UNSYNCD, | |
63 | STATE_START_OF_COMMUNICATION, | |
64 | STATE_MILLER_X, | |
65 | STATE_MILLER_Y, | |
66 | STATE_MILLER_Z, | |
67 | // DROP_NONE, | |
68 | // DROP_FIRST_HALF, | |
69 | } state; | |
70 | uint16_t shiftReg; | |
71 | int16_t bitCount; | |
72 | uint16_t len; | |
73 | uint16_t byteCntMax; | |
74 | uint16_t posCnt; | |
75 | uint16_t syncBit; | |
76 | uint8_t parityBits; | |
77 | uint8_t parityLen; | |
78 | uint32_t fourBits; | |
79 | uint32_t startTime, endTime; | |
80 | uint8_t *output; | |
81 | uint8_t *parity; | |
82 | } tUart; | |
83 | ||
84 | static uint32_t iso14a_timeout; | |
85 | #define MAX_ISO14A_TIMEOUT 524288 | |
86 | ||
87 | int rsamples = 0; | |
88 | uint8_t trigger = 0; | |
89 | // the block number for the ISO14443-4 PCB | |
90 | static uint8_t iso14_pcb_blocknum = 0; | |
91 | ||
92 | // | |
93 | // ISO14443 timing: | |
94 | // | |
95 | // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles | |
96 | #define REQUEST_GUARD_TIME (7000/16 + 1) | |
97 | // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles | |
98 | #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1) | |
99 | // bool LastCommandWasRequest = false; | |
100 | ||
101 | // | |
102 | // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz) | |
103 | // | |
104 | // When the PM acts as reader and is receiving tag data, it takes | |
105 | // 3 ticks delay in the AD converter | |
106 | // 16 ticks until the modulation detector completes and sets curbit | |
107 | // 8 ticks until bit_to_arm is assigned from curbit | |
108 | // 8*16 ticks for the transfer from FPGA to ARM | |
109 | // 4*16 ticks until we measure the time | |
110 | // - 8*16 ticks because we measure the time of the previous transfer | |
111 | #define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16) | |
112 | ||
113 | // When the PM acts as a reader and is sending, it takes | |
114 | // 4*16 ticks until we can write data to the sending hold register | |
115 | // 8*16 ticks until the SHR is transferred to the Sending Shift Register | |
116 | // 8 ticks until the first transfer starts | |
117 | // 8 ticks later the FPGA samples the data | |
118 | // 1 tick to assign mod_sig_coil | |
119 | #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1) | |
120 | ||
121 | // When the PM acts as tag and is receiving it takes | |
122 | // 2 ticks delay in the RF part (for the first falling edge), | |
123 | // 3 ticks for the A/D conversion, | |
124 | // 8 ticks on average until the start of the SSC transfer, | |
125 | // 8 ticks until the SSC samples the first data | |
126 | // 7*16 ticks to complete the transfer from FPGA to ARM | |
127 | // 8 ticks until the next ssp_clk rising edge | |
128 | // 4*16 ticks until we measure the time | |
129 | // - 8*16 ticks because we measure the time of the previous transfer | |
130 | #define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16) | |
131 | ||
132 | // The FPGA will report its internal sending delay in | |
133 | uint16_t FpgaSendQueueDelay; | |
134 | // the 5 first bits are the number of bits buffered in mod_sig_buf | |
135 | // the last three bits are the remaining ticks/2 after the mod_sig_buf shift | |
136 | #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1) | |
137 | ||
138 | // When the PM acts as tag and is sending, it takes | |
139 | // 4*16 + 8 ticks until we can write data to the sending hold register | |
140 | // 8*16 ticks until the SHR is transferred to the Sending Shift Register | |
141 | // 8 ticks later the FPGA samples the first data | |
142 | // + 16 ticks until assigned to mod_sig | |
143 | // + 1 tick to assign mod_sig_coil | |
144 | // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf) | |
145 | #define DELAY_ARM2AIR_AS_TAG (4*16 + 8 + 8*16 + 8 + 16 + 1 + DELAY_FPGA_QUEUE) | |
146 | ||
147 | // When the PM acts as sniffer and is receiving tag data, it takes | |
148 | // 3 ticks A/D conversion | |
149 | // 14 ticks to complete the modulation detection | |
150 | // 8 ticks (on average) until the result is stored in to_arm | |
151 | // + the delays in transferring data - which is the same for | |
152 | // sniffing reader and tag data and therefore not relevant | |
153 | #define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8) | |
154 | ||
155 | // When the PM acts as sniffer and is receiving reader data, it takes | |
156 | // 2 ticks delay in analogue RF receiver (for the falling edge of the | |
157 | // start bit, which marks the start of the communication) | |
158 | // 3 ticks A/D conversion | |
159 | // 8 ticks on average until the data is stored in to_arm. | |
160 | // + the delays in transferring data - which is the same for | |
161 | // sniffing reader and tag data and therefore not relevant | |
162 | #define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8) | |
163 | ||
164 | //variables used for timing purposes: | |
165 | //these are in ssp_clk cycles: | |
166 | static uint32_t NextTransferTime; | |
167 | static uint32_t LastTimeProxToAirStart; | |
168 | static uint32_t LastProxToAirDuration; | |
169 | ||
170 | ||
171 | ||
172 | // CARD TO READER - manchester | |
173 | // Sequence D: 11110000 modulation with subcarrier during first half | |
174 | // Sequence E: 00001111 modulation with subcarrier during second half | |
175 | // Sequence F: 00000000 no modulation with subcarrier | |
176 | // READER TO CARD - miller | |
177 | // Sequence X: 00001100 drop after half a period | |
178 | // Sequence Y: 00000000 no drop | |
179 | // Sequence Z: 11000000 drop at start | |
180 | #define SEC_D 0xf0 | |
181 | #define SEC_E 0x0f | |
182 | #define SEC_F 0x00 | |
183 | #define SEC_X 0x0c | |
184 | #define SEC_Y 0x00 | |
185 | #define SEC_Z 0xc0 | |
186 | ||
187 | void iso14a_set_trigger(bool enable) { | |
188 | trigger = enable; | |
189 | } | |
190 | ||
191 | ||
192 | void iso14a_set_timeout(uint32_t timeout) { | |
193 | // adjust timeout by FPGA delays and 2 additional ssp_frames to detect SOF | |
194 | iso14a_timeout = timeout + (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/(16*8) + 2; | |
195 | if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", timeout, timeout / 106); | |
196 | } | |
197 | ||
198 | ||
199 | uint32_t iso14a_get_timeout(void) { | |
200 | return iso14a_timeout - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/(16*8) - 2; | |
201 | } | |
202 | ||
203 | //----------------------------------------------------------------------------- | |
204 | // Generate the parity value for a byte sequence | |
205 | // | |
206 | //----------------------------------------------------------------------------- | |
207 | void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par) | |
208 | { | |
209 | uint16_t paritybit_cnt = 0; | |
210 | uint16_t paritybyte_cnt = 0; | |
211 | uint8_t parityBits = 0; | |
212 | ||
213 | for (uint16_t i = 0; i < iLen; i++) { | |
214 | // Generate the parity bits | |
215 | parityBits |= ((oddparity8(pbtCmd[i])) << (7-paritybit_cnt)); | |
216 | if (paritybit_cnt == 7) { | |
217 | par[paritybyte_cnt] = parityBits; // save 8 Bits parity | |
218 | parityBits = 0; // and advance to next Parity Byte | |
219 | paritybyte_cnt++; | |
220 | paritybit_cnt = 0; | |
221 | } else { | |
222 | paritybit_cnt++; | |
223 | } | |
224 | } | |
225 | ||
226 | // save remaining parity bits | |
227 | par[paritybyte_cnt] = parityBits; | |
228 | ||
229 | } | |
230 | ||
231 | void AppendCrc14443a(uint8_t* data, int len) | |
232 | { | |
233 | ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1); | |
234 | } | |
235 | ||
236 | static void AppendCrc14443b(uint8_t* data, int len) | |
237 | { | |
238 | ComputeCrc14443(CRC_14443_B,data,len,data+len,data+len+1); | |
239 | } | |
240 | ||
241 | ||
242 | //============================================================================= | |
243 | // ISO 14443 Type A - Miller decoder | |
244 | //============================================================================= | |
245 | // Basics: | |
246 | // This decoder is used when the PM3 acts as a tag. | |
247 | // The reader will generate "pauses" by temporarily switching of the field. | |
248 | // At the PM3 antenna we will therefore measure a modulated antenna voltage. | |
249 | // The FPGA does a comparison with a threshold and would deliver e.g.: | |
250 | // ........ 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 ....... | |
251 | // The Miller decoder needs to identify the following sequences: | |
252 | // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0") | |
253 | // 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information") | |
254 | // 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1") | |
255 | // Note 1: the bitstream may start at any time. We therefore need to sync. | |
256 | // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence. | |
257 | //----------------------------------------------------------------------------- | |
258 | static tUart Uart; | |
259 | ||
260 | // Lookup-Table to decide if 4 raw bits are a modulation. | |
261 | // We accept the following: | |
262 | // 0001 - a 3 tick wide pause | |
263 | // 0011 - a 2 tick wide pause, or a three tick wide pause shifted left | |
264 | // 0111 - a 2 tick wide pause shifted left | |
265 | // 1001 - a 2 tick wide pause shifted right | |
266 | const bool Mod_Miller_LUT[] = { | |
267 | false, true, false, true, false, false, false, true, | |
268 | false, true, false, false, false, false, false, false | |
269 | }; | |
270 | #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4]) | |
271 | #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)]) | |
272 | ||
273 | static void UartReset() | |
274 | { | |
275 | Uart.state = STATE_UNSYNCD; | |
276 | Uart.bitCount = 0; | |
277 | Uart.len = 0; // number of decoded data bytes | |
278 | Uart.parityLen = 0; // number of decoded parity bytes | |
279 | Uart.shiftReg = 0; // shiftreg to hold decoded data bits | |
280 | Uart.parityBits = 0; // holds 8 parity bits | |
281 | Uart.startTime = 0; | |
282 | Uart.endTime = 0; | |
283 | } | |
284 | ||
285 | static void UartInit(uint8_t *data, uint8_t *parity) | |
286 | { | |
287 | Uart.output = data; | |
288 | Uart.parity = parity; | |
289 | Uart.fourBits = 0x00000000; // clear the buffer for 4 Bits | |
290 | UartReset(); | |
291 | } | |
292 | ||
293 | // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time | |
294 | static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time) | |
295 | { | |
296 | ||
297 | Uart.fourBits = (Uart.fourBits << 8) | bit; | |
298 | ||
299 | if (Uart.state == STATE_UNSYNCD) { // not yet synced | |
300 | ||
301 | Uart.syncBit = 9999; // not set | |
302 | // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from | |
303 | // Sequence X followed by Sequence Y followed by Sequence Z (111100x1 11111111 00x11111) | |
304 | // we therefore look for a ...xx11111111111100x11111xxxxxx... pattern | |
305 | // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's) | |
306 | #define ISO14443A_STARTBIT_MASK 0x07FFEF80 // mask is 00000111 11111111 11101111 10000000 | |
307 | #define ISO14443A_STARTBIT_PATTERN 0x07FF8F80 // pattern is 00000111 11111111 10001111 10000000 | |
308 | if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7; | |
309 | else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6; | |
310 | else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5; | |
311 | else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4; | |
312 | else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3; | |
313 | else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2; | |
314 | else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1; | |
315 | else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0; | |
316 | ||
317 | if (Uart.syncBit != 9999) { // found a sync bit | |
318 | Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8); | |
319 | Uart.startTime -= Uart.syncBit; | |
320 | Uart.endTime = Uart.startTime; | |
321 | Uart.state = STATE_START_OF_COMMUNICATION; | |
322 | } | |
323 | ||
324 | } else { | |
325 | ||
326 | if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) { | |
327 | if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation in both halves - error | |
328 | UartReset(); | |
329 | } else { // Modulation in first half = Sequence Z = logic "0" | |
330 | if (Uart.state == STATE_MILLER_X) { // error - must not follow after X | |
331 | UartReset(); | |
332 | } else { | |
333 | Uart.bitCount++; | |
334 | Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg | |
335 | Uart.state = STATE_MILLER_Z; | |
336 | Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6; | |
337 | if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity) | |
338 | Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); | |
339 | Uart.parityBits <<= 1; // make room for the parity bit | |
340 | Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit | |
341 | Uart.bitCount = 0; | |
342 | Uart.shiftReg = 0; | |
343 | if((Uart.len&0x0007) == 0) { // every 8 data bytes | |
344 | Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits | |
345 | Uart.parityBits = 0; | |
346 | } | |
347 | } | |
348 | } | |
349 | } | |
350 | } else { | |
351 | if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1" | |
352 | Uart.bitCount++; | |
353 | Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg | |
354 | Uart.state = STATE_MILLER_X; | |
355 | Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2; | |
356 | if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity) | |
357 | Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); | |
358 | Uart.parityBits <<= 1; // make room for the new parity bit | |
359 | Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit | |
360 | Uart.bitCount = 0; | |
361 | Uart.shiftReg = 0; | |
362 | if ((Uart.len&0x0007) == 0) { // every 8 data bytes | |
363 | Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits | |
364 | Uart.parityBits = 0; | |
365 | } | |
366 | } | |
367 | } else { // no modulation in both halves - Sequence Y | |
368 | if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication | |
369 | Uart.state = STATE_UNSYNCD; | |
370 | Uart.bitCount--; // last "0" was part of EOC sequence | |
371 | Uart.shiftReg <<= 1; // drop it | |
372 | if(Uart.bitCount > 0) { // if we decoded some bits | |
373 | Uart.shiftReg >>= (9 - Uart.bitCount); // right align them | |
374 | Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); // add last byte to the output | |
375 | Uart.parityBits <<= 1; // add a (void) parity bit | |
376 | Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align parity bits | |
377 | Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store it | |
378 | return true; | |
379 | } else if (Uart.len & 0x0007) { // there are some parity bits to store | |
380 | Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align remaining parity bits | |
381 | Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store them | |
382 | } | |
383 | if (Uart.len) { | |
384 | return true; // we are finished with decoding the raw data sequence | |
385 | } else { | |
386 | UartReset(); // Nothing received - start over | |
387 | } | |
388 | } | |
389 | if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC | |
390 | UartReset(); | |
391 | } else { // a logic "0" | |
392 | Uart.bitCount++; | |
393 | Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg | |
394 | Uart.state = STATE_MILLER_Y; | |
395 | if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity) | |
396 | Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); | |
397 | Uart.parityBits <<= 1; // make room for the parity bit | |
398 | Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit | |
399 | Uart.bitCount = 0; | |
400 | Uart.shiftReg = 0; | |
401 | if ((Uart.len&0x0007) == 0) { // every 8 data bytes | |
402 | Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits | |
403 | Uart.parityBits = 0; | |
404 | } | |
405 | } | |
406 | } | |
407 | } | |
408 | } | |
409 | ||
410 | } | |
411 | ||
412 | return false; // not finished yet, need more data | |
413 | } | |
414 | ||
415 | ||
416 | ||
417 | //============================================================================= | |
418 | // ISO 14443 Type A - Manchester decoder | |
419 | //============================================================================= | |
420 | // Basics: | |
421 | // This decoder is used when the PM3 acts as a reader. | |
422 | // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage | |
423 | // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following: | |
424 | // ........ 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 ....... | |
425 | // The Manchester decoder needs to identify the following sequences: | |
426 | // 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication") | |
427 | // 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0 | |
428 | // 8 ticks unmodulated: Sequence F = end of communication | |
429 | // 8 ticks modulated: A collision. Save the collision position and treat as Sequence D | |
430 | // Note 1: the bitstream may start at any time. We therefore need to sync. | |
431 | // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only) | |
432 | static tDemod Demod; | |
433 | ||
434 | // Lookup-Table to decide if 4 raw bits are a modulation. | |
435 | // We accept three or four "1" in any position | |
436 | const bool Mod_Manchester_LUT[] = { | |
437 | false, false, false, false, false, false, false, true, | |
438 | false, false, false, true, false, true, true, true | |
439 | }; | |
440 | ||
441 | #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4]) | |
442 | #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)]) | |
443 | ||
444 | ||
445 | static void DemodReset() | |
446 | { | |
447 | Demod.state = DEMOD_UNSYNCD; | |
448 | Demod.len = 0; // number of decoded data bytes | |
449 | Demod.parityLen = 0; | |
450 | Demod.shiftReg = 0; // shiftreg to hold decoded data bits | |
451 | Demod.parityBits = 0; // | |
452 | Demod.collisionPos = 0; // Position of collision bit | |
453 | Demod.twoBits = 0xffff; // buffer for 2 Bits | |
454 | Demod.highCnt = 0; | |
455 | Demod.startTime = 0; | |
456 | Demod.endTime = 0; | |
457 | } | |
458 | ||
459 | static void DemodInit(uint8_t *data, uint8_t *parity) | |
460 | { | |
461 | Demod.output = data; | |
462 | Demod.parity = parity; | |
463 | DemodReset(); | |
464 | } | |
465 | ||
466 | // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time | |
467 | static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time) | |
468 | { | |
469 | ||
470 | Demod.twoBits = (Demod.twoBits << 8) | bit; | |
471 | ||
472 | if (Demod.state == DEMOD_UNSYNCD) { | |
473 | ||
474 | if (Demod.highCnt < 2) { // wait for a stable unmodulated signal | |
475 | if (Demod.twoBits == 0x0000) { | |
476 | Demod.highCnt++; | |
477 | } else { | |
478 | Demod.highCnt = 0; | |
479 | } | |
480 | } else { | |
481 | Demod.syncBit = 0xFFFF; // not set | |
482 | if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7; | |
483 | else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6; | |
484 | else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5; | |
485 | else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4; | |
486 | else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3; | |
487 | else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2; | |
488 | else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1; | |
489 | else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0; | |
490 | if (Demod.syncBit != 0xFFFF) { | |
491 | Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8); | |
492 | Demod.startTime -= Demod.syncBit; | |
493 | Demod.bitCount = offset; // number of decoded data bits | |
494 | Demod.state = DEMOD_MANCHESTER_DATA; | |
495 | } | |
496 | } | |
497 | ||
498 | } else { | |
499 | ||
500 | if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half | |
501 | if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... and in second half = collision | |
502 | if (!Demod.collisionPos) { | |
503 | Demod.collisionPos = (Demod.len << 3) + Demod.bitCount; | |
504 | } | |
505 | } // modulation in first half only - Sequence D = 1 | |
506 | Demod.bitCount++; | |
507 | Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg | |
508 | if(Demod.bitCount == 9) { // if we decoded a full byte (including parity) | |
509 | Demod.output[Demod.len++] = (Demod.shiftReg & 0xff); | |
510 | Demod.parityBits <<= 1; // make room for the parity bit | |
511 | Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit | |
512 | Demod.bitCount = 0; | |
513 | Demod.shiftReg = 0; | |
514 | if((Demod.len&0x0007) == 0) { // every 8 data bytes | |
515 | Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits | |
516 | Demod.parityBits = 0; | |
517 | } | |
518 | } | |
519 | Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4; | |
520 | } else { // no modulation in first half | |
521 | if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // and modulation in second half = Sequence E = 0 | |
522 | Demod.bitCount++; | |
523 | Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg | |
524 | if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity) | |
525 | Demod.output[Demod.len++] = (Demod.shiftReg & 0xff); | |
526 | Demod.parityBits <<= 1; // make room for the new parity bit | |
527 | Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit | |
528 | Demod.bitCount = 0; | |
529 | Demod.shiftReg = 0; | |
530 | if ((Demod.len&0x0007) == 0) { // every 8 data bytes | |
531 | Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits1 | |
532 | Demod.parityBits = 0; | |
533 | } | |
534 | } | |
535 | Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1); | |
536 | } else { // no modulation in both halves - End of communication | |
537 | if(Demod.bitCount > 0) { // there are some remaining data bits | |
538 | Demod.shiftReg >>= (9 - Demod.bitCount); // right align the decoded bits | |
539 | Demod.output[Demod.len++] = Demod.shiftReg & 0xff; // and add them to the output | |
540 | Demod.parityBits <<= 1; // add a (void) parity bit | |
541 | Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits | |
542 | Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them | |
543 | return true; | |
544 | } else if (Demod.len & 0x0007) { // there are some parity bits to store | |
545 | Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits | |
546 | Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them | |
547 | } | |
548 | if (Demod.len) { | |
549 | return true; // we are finished with decoding the raw data sequence | |
550 | } else { // nothing received. Start over | |
551 | DemodReset(); | |
552 | } | |
553 | } | |
554 | } | |
555 | ||
556 | } | |
557 | ||
558 | return false; // not finished yet, need more data | |
559 | } | |
560 | ||
561 | //============================================================================= | |
562 | // Finally, a `sniffer' for ISO 14443 Type A | |
563 | // Both sides of communication! | |
564 | //============================================================================= | |
565 | ||
566 | //----------------------------------------------------------------------------- | |
567 | // Record the sequence of commands sent by the reader to the tag, with | |
568 | // triggering so that we start recording at the point that the tag is moved | |
569 | // near the reader. | |
570 | //----------------------------------------------------------------------------- | |
571 | void RAMFUNC SnoopIso14443a(uint8_t param) { | |
572 | // param: | |
573 | // bit 0 - trigger from first card answer | |
574 | // bit 1 - trigger from first reader 7-bit request | |
575 | ||
576 | LEDsoff(); | |
577 | ||
578 | iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER); | |
579 | ||
580 | // Allocate memory from BigBuf for some buffers | |
581 | // free all previous allocations first | |
582 | BigBuf_free(); | |
583 | ||
584 | // The command (reader -> tag) that we're receiving. | |
585 | uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE); | |
586 | uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE); | |
587 | ||
588 | // The response (tag -> reader) that we're receiving. | |
589 | uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE); | |
590 | uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE); | |
591 | ||
592 | // The DMA buffer, used to stream samples from the FPGA | |
593 | uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE); | |
594 | ||
595 | // init trace buffer | |
596 | clear_trace(); | |
597 | set_tracing(true); | |
598 | ||
599 | uint8_t *data = dmaBuf; | |
600 | uint8_t previous_data = 0; | |
601 | int maxDataLen = 0; | |
602 | int dataLen = 0; | |
603 | bool TagIsActive = false; | |
604 | bool ReaderIsActive = false; | |
605 | ||
606 | // Set up the demodulator for tag -> reader responses. | |
607 | DemodInit(receivedResponse, receivedResponsePar); | |
608 | ||
609 | // Set up the demodulator for the reader -> tag commands | |
610 | UartInit(receivedCmd, receivedCmdPar); | |
611 | ||
612 | // Setup and start DMA. | |
613 | FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); | |
614 | ||
615 | // We won't start recording the frames that we acquire until we trigger; | |
616 | // a good trigger condition to get started is probably when we see a | |
617 | // response from the tag. | |
618 | // triggered == false -- to wait first for card | |
619 | bool triggered = !(param & 0x03); | |
620 | ||
621 | // And now we loop, receiving samples. | |
622 | for(uint32_t rsamples = 0; true; ) { | |
623 | ||
624 | if(BUTTON_PRESS()) { | |
625 | DbpString("cancelled by button"); | |
626 | break; | |
627 | } | |
628 | ||
629 | LED_A_ON(); | |
630 | WDT_HIT(); | |
631 | ||
632 | int register readBufDataP = data - dmaBuf; | |
633 | int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; | |
634 | if (readBufDataP <= dmaBufDataP){ | |
635 | dataLen = dmaBufDataP - readBufDataP; | |
636 | } else { | |
637 | dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; | |
638 | } | |
639 | // test for length of buffer | |
640 | if(dataLen > maxDataLen) { | |
641 | maxDataLen = dataLen; | |
642 | if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) { | |
643 | Dbprintf("blew circular buffer! dataLen=%d", dataLen); | |
644 | break; | |
645 | } | |
646 | } | |
647 | if(dataLen < 1) continue; | |
648 | ||
649 | // primary buffer was stopped( <-- we lost data! | |
650 | if (!AT91C_BASE_PDC_SSC->PDC_RCR) { | |
651 | AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf; | |
652 | AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE; | |
653 | Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary | |
654 | } | |
655 | // secondary buffer sets as primary, secondary buffer was stopped | |
656 | if (!AT91C_BASE_PDC_SSC->PDC_RNCR) { | |
657 | AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; | |
658 | AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE; | |
659 | } | |
660 | ||
661 | LED_A_OFF(); | |
662 | ||
663 | if (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder | |
664 | ||
665 | if(!TagIsActive) { // no need to try decoding reader data if the tag is sending | |
666 | uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4); | |
667 | if (MillerDecoding(readerdata, (rsamples-1)*4)) { | |
668 | LED_C_ON(); | |
669 | ||
670 | // check - if there is a short 7bit request from reader | |
671 | if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = true; | |
672 | ||
673 | if(triggered) { | |
674 | if (!LogTrace(receivedCmd, | |
675 | Uart.len, | |
676 | Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, | |
677 | Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, | |
678 | Uart.parity, | |
679 | true)) break; | |
680 | } | |
681 | /* And ready to receive another command. */ | |
682 | UartReset(); | |
683 | /* And also reset the demod code, which might have been */ | |
684 | /* false-triggered by the commands from the reader. */ | |
685 | DemodReset(); | |
686 | LED_B_OFF(); | |
687 | } | |
688 | ReaderIsActive = (Uart.state != STATE_UNSYNCD); | |
689 | } | |
690 | ||
691 | if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time | |
692 | uint8_t tagdata = (previous_data << 4) | (*data & 0x0F); | |
693 | if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) { | |
694 | LED_B_ON(); | |
695 | ||
696 | if (!LogTrace(receivedResponse, | |
697 | Demod.len, | |
698 | Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, | |
699 | Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, | |
700 | Demod.parity, | |
701 | false)) break; | |
702 | ||
703 | if ((!triggered) && (param & 0x01)) triggered = true; | |
704 | ||
705 | // And ready to receive another response. | |
706 | DemodReset(); | |
707 | // And reset the Miller decoder including itS (now outdated) input buffer | |
708 | UartInit(receivedCmd, receivedCmdPar); | |
709 | ||
710 | LED_C_OFF(); | |
711 | } | |
712 | TagIsActive = (Demod.state != DEMOD_UNSYNCD); | |
713 | } | |
714 | } | |
715 | ||
716 | previous_data = *data; | |
717 | rsamples++; | |
718 | data++; | |
719 | if(data == dmaBuf + DMA_BUFFER_SIZE) { | |
720 | data = dmaBuf; | |
721 | } | |
722 | } // main cycle | |
723 | ||
724 | DbpString("COMMAND FINISHED"); | |
725 | ||
726 | FpgaDisableSscDma(); | |
727 | Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len); | |
728 | Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]); | |
729 | LEDsoff(); | |
730 | } | |
731 | ||
732 | //----------------------------------------------------------------------------- | |
733 | // Prepare tag messages | |
734 | //----------------------------------------------------------------------------- | |
735 | static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity) | |
736 | { | |
737 | ToSendReset(); | |
738 | ||
739 | // Correction bit, might be removed when not needed | |
740 | ToSendStuffBit(0); | |
741 | ToSendStuffBit(0); | |
742 | ToSendStuffBit(0); | |
743 | ToSendStuffBit(0); | |
744 | ToSendStuffBit(1); // 1 | |
745 | ToSendStuffBit(0); | |
746 | ToSendStuffBit(0); | |
747 | ToSendStuffBit(0); | |
748 | ||
749 | // Send startbit | |
750 | ToSend[++ToSendMax] = SEC_D; | |
751 | LastProxToAirDuration = 8 * ToSendMax - 4; | |
752 | ||
753 | for(uint16_t i = 0; i < len; i++) { | |
754 | uint8_t b = cmd[i]; | |
755 | ||
756 | // Data bits | |
757 | for(uint16_t j = 0; j < 8; j++) { | |
758 | if(b & 1) { | |
759 | ToSend[++ToSendMax] = SEC_D; | |
760 | } else { | |
761 | ToSend[++ToSendMax] = SEC_E; | |
762 | } | |
763 | b >>= 1; | |
764 | } | |
765 | ||
766 | // Get the parity bit | |
767 | if (parity[i>>3] & (0x80>>(i&0x0007))) { | |
768 | ToSend[++ToSendMax] = SEC_D; | |
769 | LastProxToAirDuration = 8 * ToSendMax - 4; | |
770 | } else { | |
771 | ToSend[++ToSendMax] = SEC_E; | |
772 | LastProxToAirDuration = 8 * ToSendMax; | |
773 | } | |
774 | } | |
775 | ||
776 | // Send stopbit | |
777 | ToSend[++ToSendMax] = SEC_F; | |
778 | ||
779 | // Convert from last byte pos to length | |
780 | ToSendMax++; | |
781 | } | |
782 | ||
783 | ||
784 | static void Code4bitAnswerAsTag(uint8_t cmd) | |
785 | { | |
786 | int i; | |
787 | ||
788 | ToSendReset(); | |
789 | ||
790 | // Correction bit, might be removed when not needed | |
791 | ToSendStuffBit(0); | |
792 | ToSendStuffBit(0); | |
793 | ToSendStuffBit(0); | |
794 | ToSendStuffBit(0); | |
795 | ToSendStuffBit(1); // 1 | |
796 | ToSendStuffBit(0); | |
797 | ToSendStuffBit(0); | |
798 | ToSendStuffBit(0); | |
799 | ||
800 | // Send startbit | |
801 | ToSend[++ToSendMax] = SEC_D; | |
802 | ||
803 | uint8_t b = cmd; | |
804 | for(i = 0; i < 4; i++) { | |
805 | if(b & 1) { | |
806 | ToSend[++ToSendMax] = SEC_D; | |
807 | LastProxToAirDuration = 8 * ToSendMax - 4; | |
808 | } else { | |
809 | ToSend[++ToSendMax] = SEC_E; | |
810 | LastProxToAirDuration = 8 * ToSendMax; | |
811 | } | |
812 | b >>= 1; | |
813 | } | |
814 | ||
815 | // Send stopbit | |
816 | ToSend[++ToSendMax] = SEC_F; | |
817 | ||
818 | // Convert from last byte pos to length | |
819 | ToSendMax++; | |
820 | } | |
821 | ||
822 | ||
823 | static uint8_t *LastReaderTraceTime = NULL; | |
824 | ||
825 | static void EmLogTraceReader(void) { | |
826 | // remember last reader trace start to fix timing info later | |
827 | LastReaderTraceTime = BigBuf_get_addr() + BigBuf_get_traceLen(); | |
828 | LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, true); | |
829 | } | |
830 | ||
831 | ||
832 | static void FixLastReaderTraceTime(uint32_t tag_StartTime) { | |
833 | uint32_t reader_EndTime = Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG; | |
834 | uint32_t reader_StartTime = Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG; | |
835 | uint16_t reader_modlen = reader_EndTime - reader_StartTime; | |
836 | uint16_t approx_fdt = tag_StartTime - reader_EndTime; | |
837 | uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20; | |
838 | reader_StartTime = tag_StartTime - exact_fdt - reader_modlen; | |
839 | LastReaderTraceTime[0] = (reader_StartTime >> 0) & 0xff; | |
840 | LastReaderTraceTime[1] = (reader_StartTime >> 8) & 0xff; | |
841 | LastReaderTraceTime[2] = (reader_StartTime >> 16) & 0xff; | |
842 | LastReaderTraceTime[3] = (reader_StartTime >> 24) & 0xff; | |
843 | } | |
844 | ||
845 | ||
846 | static void EmLogTraceTag(uint8_t *tag_data, uint16_t tag_len, uint8_t *tag_Parity, uint32_t ProxToAirDuration) { | |
847 | uint32_t tag_StartTime = LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG; | |
848 | uint32_t tag_EndTime = (LastTimeProxToAirStart + ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG; | |
849 | LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, false); | |
850 | FixLastReaderTraceTime(tag_StartTime); | |
851 | } | |
852 | ||
853 | ||
854 | //----------------------------------------------------------------------------- | |
855 | // Wait for commands from reader | |
856 | // Stop when button is pressed | |
857 | // Or return true when command is captured | |
858 | //----------------------------------------------------------------------------- | |
859 | static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len) | |
860 | { | |
861 | // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen | |
862 | // only, since we are receiving, not transmitting). | |
863 | // Signal field is off with the appropriate LED | |
864 | LED_D_OFF(); | |
865 | FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN); | |
866 | ||
867 | // Now run a `software UART' on the stream of incoming samples. | |
868 | UartInit(received, parity); | |
869 | ||
870 | // clear RXRDY: | |
871 | uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; | |
872 | ||
873 | for(;;) { | |
874 | WDT_HIT(); | |
875 | ||
876 | if(BUTTON_PRESS()) return false; | |
877 | ||
878 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { | |
879 | b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; | |
880 | if(MillerDecoding(b, 0)) { | |
881 | *len = Uart.len; | |
882 | EmLogTraceReader(); | |
883 | return true; | |
884 | } | |
885 | } | |
886 | } | |
887 | } | |
888 | ||
889 | ||
890 | static int EmSend4bitEx(uint8_t resp); | |
891 | int EmSend4bit(uint8_t resp); | |
892 | static int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, uint8_t *par); | |
893 | int EmSendCmdEx(uint8_t *resp, uint16_t respLen); | |
894 | int EmSendPrecompiledCmd(tag_response_info_t *response_info); | |
895 | ||
896 | ||
897 | static bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) { | |
898 | // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes | |
899 | // This will need the following byte array for a modulation sequence | |
900 | // 144 data bits (18 * 8) | |
901 | // 18 parity bits | |
902 | // 2 Start and stop | |
903 | // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA) | |
904 | // 1 just for the case | |
905 | // ----------- + | |
906 | // 166 bytes, since every bit that needs to be send costs us a byte | |
907 | // | |
908 | ||
909 | ||
910 | // Prepare the tag modulation bits from the message | |
911 | GetParity(response_info->response, response_info->response_n, &(response_info->par)); | |
912 | CodeIso14443aAsTagPar(response_info->response,response_info->response_n, &(response_info->par)); | |
913 | ||
914 | // Make sure we do not exceed the free buffer space | |
915 | if (ToSendMax > max_buffer_size) { | |
916 | Dbprintf("Out of memory, when modulating bits for tag answer:"); | |
917 | Dbhexdump(response_info->response_n, response_info->response, false); | |
918 | return false; | |
919 | } | |
920 | ||
921 | // Copy the byte array, used for this modulation to the buffer position | |
922 | memcpy(response_info->modulation, ToSend, ToSendMax); | |
923 | ||
924 | // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them | |
925 | response_info->modulation_n = ToSendMax; | |
926 | response_info->ProxToAirDuration = LastProxToAirDuration; | |
927 | ||
928 | return true; | |
929 | } | |
930 | ||
931 | ||
932 | // "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit. | |
933 | // Coded responses need one byte per bit to transfer (data, parity, start, stop, correction) | |
934 | // 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits for the modulation | |
935 | // -> need 273 bytes buffer | |
936 | #define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 273 | |
937 | ||
938 | bool prepare_allocated_tag_modulation(tag_response_info_t* response_info, uint8_t **buffer, size_t *max_buffer_size) { | |
939 | ||
940 | // Retrieve and store the current buffer index | |
941 | response_info->modulation = *buffer; | |
942 | ||
943 | // Forward the prepare tag modulation function to the inner function | |
944 | if (prepare_tag_modulation(response_info, *max_buffer_size)) { | |
945 | // Update the free buffer offset and the remaining buffer size | |
946 | *buffer += ToSendMax; | |
947 | *max_buffer_size -= ToSendMax; | |
948 | return true; | |
949 | } else { | |
950 | return false; | |
951 | } | |
952 | } | |
953 | ||
954 | //----------------------------------------------------------------------------- | |
955 | // Main loop of simulated tag: receive commands from reader, decide what | |
956 | // response to send, and send it. | |
957 | //----------------------------------------------------------------------------- | |
958 | void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data) | |
959 | { | |
960 | uint8_t sak; | |
961 | ||
962 | // The first response contains the ATQA (note: bytes are transmitted in reverse order). | |
963 | uint8_t response1[2]; | |
964 | ||
965 | switch (tagType) { | |
966 | case 1: { // MIFARE Classic | |
967 | // Says: I am Mifare 1k - original line | |
968 | response1[0] = 0x04; | |
969 | response1[1] = 0x00; | |
970 | sak = 0x08; | |
971 | } break; | |
972 | case 2: { // MIFARE Ultralight | |
973 | // Says: I am a stupid memory tag, no crypto | |
974 | response1[0] = 0x04; | |
975 | response1[1] = 0x00; | |
976 | sak = 0x00; | |
977 | } break; | |
978 | case 3: { // MIFARE DESFire | |
979 | // Says: I am a DESFire tag, ph33r me | |
980 | response1[0] = 0x04; | |
981 | response1[1] = 0x03; | |
982 | sak = 0x20; | |
983 | } break; | |
984 | case 4: { // ISO/IEC 14443-4 | |
985 | // Says: I am a javacard (JCOP) | |
986 | response1[0] = 0x04; | |
987 | response1[1] = 0x00; | |
988 | sak = 0x28; | |
989 | } break; | |
990 | case 5: { // MIFARE TNP3XXX | |
991 | // Says: I am a toy | |
992 | response1[0] = 0x01; | |
993 | response1[1] = 0x0f; | |
994 | sak = 0x01; | |
995 | } break; | |
996 | default: { | |
997 | Dbprintf("Error: unkown tagtype (%d)",tagType); | |
998 | return; | |
999 | } break; | |
1000 | } | |
1001 | ||
1002 | // The second response contains the (mandatory) first 24 bits of the UID | |
1003 | uint8_t response2[5] = {0x00}; | |
1004 | ||
1005 | // Check if the uid uses the (optional) part | |
1006 | uint8_t response2a[5] = {0x00}; | |
1007 | ||
1008 | if (uid_2nd) { | |
1009 | response2[0] = 0x88; | |
1010 | num_to_bytes(uid_1st,3,response2+1); | |
1011 | num_to_bytes(uid_2nd,4,response2a); | |
1012 | response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3]; | |
1013 | ||
1014 | // Configure the ATQA and SAK accordingly | |
1015 | response1[0] |= 0x40; | |
1016 | sak |= 0x04; | |
1017 | } else { | |
1018 | num_to_bytes(uid_1st,4,response2); | |
1019 | // Configure the ATQA and SAK accordingly | |
1020 | response1[0] &= 0xBF; | |
1021 | sak &= 0xFB; | |
1022 | } | |
1023 | ||
1024 | // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID. | |
1025 | response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3]; | |
1026 | ||
1027 | // Prepare the mandatory SAK (for 4 and 7 byte UID) | |
1028 | uint8_t response3[3] = {0x00}; | |
1029 | response3[0] = sak; | |
1030 | ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]); | |
1031 | ||
1032 | // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit | |
1033 | uint8_t response3a[3] = {0x00}; | |
1034 | response3a[0] = sak & 0xFB; | |
1035 | ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]); | |
1036 | ||
1037 | uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce | |
1038 | uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS: | |
1039 | // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present, | |
1040 | // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1 | |
1041 | // 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) | |
1042 | // TC(1) = 0x02: CID supported, NAD not supported | |
1043 | ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]); | |
1044 | ||
1045 | #define TAG_RESPONSE_COUNT 7 | |
1046 | tag_response_info_t responses[TAG_RESPONSE_COUNT] = { | |
1047 | { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type | |
1048 | { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid | |
1049 | { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked | |
1050 | { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1 | |
1051 | { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2 | |
1052 | { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce) | |
1053 | { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS | |
1054 | }; | |
1055 | ||
1056 | // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it | |
1057 | // Such a response is less time critical, so we can prepare them on the fly | |
1058 | #define DYNAMIC_RESPONSE_BUFFER_SIZE 64 | |
1059 | #define DYNAMIC_MODULATION_BUFFER_SIZE 512 | |
1060 | uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE]; | |
1061 | uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE]; | |
1062 | tag_response_info_t dynamic_response_info = { | |
1063 | .response = dynamic_response_buffer, | |
1064 | .response_n = 0, | |
1065 | .modulation = dynamic_modulation_buffer, | |
1066 | .modulation_n = 0 | |
1067 | }; | |
1068 | ||
1069 | // We need to listen to the high-frequency, peak-detected path. | |
1070 | iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN); | |
1071 | ||
1072 | BigBuf_free_keep_EM(); | |
1073 | ||
1074 | // allocate buffers: | |
1075 | uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE); | |
1076 | uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE); | |
1077 | uint8_t *free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE); | |
1078 | size_t free_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE; | |
1079 | // clear trace | |
1080 | clear_trace(); | |
1081 | set_tracing(true); | |
1082 | ||
1083 | // Prepare the responses of the anticollision phase | |
1084 | // there will be not enough time to do this at the moment the reader sends it REQA | |
1085 | for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) { | |
1086 | prepare_allocated_tag_modulation(&responses[i], &free_buffer_pointer, &free_buffer_size); | |
1087 | } | |
1088 | ||
1089 | int len = 0; | |
1090 | ||
1091 | // To control where we are in the protocol | |
1092 | int order = 0; | |
1093 | int lastorder; | |
1094 | ||
1095 | // Just to allow some checks | |
1096 | int happened = 0; | |
1097 | int happened2 = 0; | |
1098 | int cmdsRecvd = 0; | |
1099 | ||
1100 | cmdsRecvd = 0; | |
1101 | tag_response_info_t* p_response; | |
1102 | ||
1103 | LED_A_ON(); | |
1104 | for(;;) { | |
1105 | // Clean receive command buffer | |
1106 | if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) { | |
1107 | DbpString("Button press"); | |
1108 | break; | |
1109 | } | |
1110 | ||
1111 | p_response = NULL; | |
1112 | ||
1113 | // Okay, look at the command now. | |
1114 | lastorder = order; | |
1115 | if(receivedCmd[0] == 0x26) { // Received a REQUEST | |
1116 | p_response = &responses[0]; order = 1; | |
1117 | } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP | |
1118 | p_response = &responses[0]; order = 6; | |
1119 | } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // Received request for UID (cascade 1) | |
1120 | p_response = &responses[1]; order = 2; | |
1121 | } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2) | |
1122 | p_response = &responses[2]; order = 20; | |
1123 | } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) { // Received a SELECT (cascade 1) | |
1124 | p_response = &responses[3]; order = 3; | |
1125 | } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) { // Received a SELECT (cascade 2) | |
1126 | p_response = &responses[4]; order = 30; | |
1127 | } else if(receivedCmd[0] == 0x30) { // Received a (plain) READ | |
1128 | EmSendCmdEx(data+(4*receivedCmd[1]),16); | |
1129 | // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]); | |
1130 | // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below | |
1131 | p_response = NULL; | |
1132 | } else if(receivedCmd[0] == 0x50) { // Received a HALT | |
1133 | p_response = NULL; | |
1134 | } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) { // Received an authentication request | |
1135 | p_response = &responses[5]; order = 7; | |
1136 | } else if(receivedCmd[0] == 0xE0) { // Received a RATS request | |
1137 | if (tagType == 1 || tagType == 2) { // RATS not supported | |
1138 | EmSend4bit(CARD_NACK_NA); | |
1139 | p_response = NULL; | |
1140 | } else { | |
1141 | p_response = &responses[6]; order = 70; | |
1142 | } | |
1143 | } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication) | |
1144 | uint32_t nr = bytes_to_num(receivedCmd,4); | |
1145 | uint32_t ar = bytes_to_num(receivedCmd+4,4); | |
1146 | Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar); | |
1147 | } else { | |
1148 | // Check for ISO 14443A-4 compliant commands, look at left nibble | |
1149 | switch (receivedCmd[0]) { | |
1150 | ||
1151 | case 0x0B: | |
1152 | case 0x0A: { // IBlock (command) | |
1153 | dynamic_response_info.response[0] = receivedCmd[0]; | |
1154 | dynamic_response_info.response[1] = 0x00; | |
1155 | dynamic_response_info.response[2] = 0x90; | |
1156 | dynamic_response_info.response[3] = 0x00; | |
1157 | dynamic_response_info.response_n = 4; | |
1158 | } break; | |
1159 | ||
1160 | case 0x1A: | |
1161 | case 0x1B: { // Chaining command | |
1162 | dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1); | |
1163 | dynamic_response_info.response_n = 2; | |
1164 | } break; | |
1165 | ||
1166 | case 0xaa: | |
1167 | case 0xbb: { | |
1168 | dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11; | |
1169 | dynamic_response_info.response_n = 2; | |
1170 | } break; | |
1171 | ||
1172 | case 0xBA: { // | |
1173 | memcpy(dynamic_response_info.response,"\xAB\x00",2); | |
1174 | dynamic_response_info.response_n = 2; | |
1175 | } break; | |
1176 | ||
1177 | case 0xCA: | |
1178 | case 0xC2: { // Readers sends deselect command | |
1179 | memcpy(dynamic_response_info.response,"\xCA\x00",2); | |
1180 | dynamic_response_info.response_n = 2; | |
1181 | } break; | |
1182 | ||
1183 | default: { | |
1184 | // Never seen this command before | |
1185 | Dbprintf("Received unknown command (len=%d):",len); | |
1186 | Dbhexdump(len,receivedCmd,false); | |
1187 | // Do not respond | |
1188 | dynamic_response_info.response_n = 0; | |
1189 | } break; | |
1190 | } | |
1191 | ||
1192 | if (dynamic_response_info.response_n > 0) { | |
1193 | // Copy the CID from the reader query | |
1194 | dynamic_response_info.response[1] = receivedCmd[1]; | |
1195 | ||
1196 | // Add CRC bytes, always used in ISO 14443A-4 compliant cards | |
1197 | AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n); | |
1198 | dynamic_response_info.response_n += 2; | |
1199 | ||
1200 | if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) { | |
1201 | Dbprintf("Error preparing tag response"); | |
1202 | break; | |
1203 | } | |
1204 | p_response = &dynamic_response_info; | |
1205 | } | |
1206 | } | |
1207 | ||
1208 | // Count number of wakeups received after a halt | |
1209 | if(order == 6 && lastorder == 5) { happened++; } | |
1210 | ||
1211 | // Count number of other messages after a halt | |
1212 | if(order != 6 && lastorder == 5) { happened2++; } | |
1213 | ||
1214 | if(cmdsRecvd > 999) { | |
1215 | DbpString("1000 commands later..."); | |
1216 | break; | |
1217 | } | |
1218 | cmdsRecvd++; | |
1219 | ||
1220 | if (p_response != NULL) { | |
1221 | EmSendPrecompiledCmd(p_response); | |
1222 | } | |
1223 | ||
1224 | if (!get_tracing()) { | |
1225 | Dbprintf("Trace Full. Simulation stopped."); | |
1226 | break; | |
1227 | } | |
1228 | } | |
1229 | ||
1230 | Dbprintf("%x %x %x", happened, happened2, cmdsRecvd); | |
1231 | LED_A_OFF(); | |
1232 | BigBuf_free_keep_EM(); | |
1233 | } | |
1234 | ||
1235 | ||
1236 | // prepare a delayed transfer. This simply shifts ToSend[] by a number | |
1237 | // of bits specified in the delay parameter. | |
1238 | static void PrepareDelayedTransfer(uint16_t delay) | |
1239 | { | |
1240 | uint8_t bitmask = 0; | |
1241 | uint8_t bits_to_shift = 0; | |
1242 | uint8_t bits_shifted = 0; | |
1243 | ||
1244 | delay &= 0x07; | |
1245 | if (delay) { | |
1246 | for (uint16_t i = 0; i < delay; i++) { | |
1247 | bitmask |= (0x01 << i); | |
1248 | } | |
1249 | ToSend[ToSendMax++] = 0x00; | |
1250 | for (uint16_t i = 0; i < ToSendMax; i++) { | |
1251 | bits_to_shift = ToSend[i] & bitmask; | |
1252 | ToSend[i] = ToSend[i] >> delay; | |
1253 | ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay)); | |
1254 | bits_shifted = bits_to_shift; | |
1255 | } | |
1256 | } | |
1257 | } | |
1258 | ||
1259 | ||
1260 | //------------------------------------------------------------------------------------- | |
1261 | // Transmit the command (to the tag) that was placed in ToSend[]. | |
1262 | // Parameter timing: | |
1263 | // if NULL: transfer at next possible time, taking into account | |
1264 | // request guard time, startup frame guard time and frame delay time | |
1265 | // if == 0: transfer immediately and return time of transfer | |
1266 | // if != 0: delay transfer until time specified | |
1267 | //------------------------------------------------------------------------------------- | |
1268 | static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing) | |
1269 | { | |
1270 | ||
1271 | FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); | |
1272 | ||
1273 | uint32_t ThisTransferTime = 0; | |
1274 | ||
1275 | if (timing) { | |
1276 | if(*timing == 0) { // Measure time | |
1277 | *timing = (GetCountSspClk() + 8) & 0xfffffff8; | |
1278 | } else { | |
1279 | PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks) | |
1280 | } | |
1281 | if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing"); | |
1282 | while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks) | |
1283 | LastTimeProxToAirStart = *timing; | |
1284 | } else { | |
1285 | ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8); | |
1286 | while(GetCountSspClk() < ThisTransferTime); | |
1287 | LastTimeProxToAirStart = ThisTransferTime; | |
1288 | } | |
1289 | ||
1290 | // clear TXRDY | |
1291 | AT91C_BASE_SSC->SSC_THR = SEC_Y; | |
1292 | ||
1293 | uint16_t c = 0; | |
1294 | for(;;) { | |
1295 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
1296 | AT91C_BASE_SSC->SSC_THR = cmd[c]; | |
1297 | c++; | |
1298 | if(c >= len) { | |
1299 | break; | |
1300 | } | |
1301 | } | |
1302 | } | |
1303 | ||
1304 | NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME); | |
1305 | } | |
1306 | ||
1307 | ||
1308 | //----------------------------------------------------------------------------- | |
1309 | // Prepare reader command (in bits, support short frames) to send to FPGA | |
1310 | //----------------------------------------------------------------------------- | |
1311 | static void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity) | |
1312 | { | |
1313 | int i, j; | |
1314 | int last; | |
1315 | uint8_t b; | |
1316 | ||
1317 | ToSendReset(); | |
1318 | ||
1319 | // Start of Communication (Seq. Z) | |
1320 | ToSend[++ToSendMax] = SEC_Z; | |
1321 | LastProxToAirDuration = 8 * (ToSendMax+1) - 6; | |
1322 | last = 0; | |
1323 | ||
1324 | size_t bytecount = nbytes(bits); | |
1325 | // Generate send structure for the data bits | |
1326 | for (i = 0; i < bytecount; i++) { | |
1327 | // Get the current byte to send | |
1328 | b = cmd[i]; | |
1329 | size_t bitsleft = MIN((bits-(i*8)),8); | |
1330 | ||
1331 | for (j = 0; j < bitsleft; j++) { | |
1332 | if (b & 1) { | |
1333 | // Sequence X | |
1334 | ToSend[++ToSendMax] = SEC_X; | |
1335 | LastProxToAirDuration = 8 * (ToSendMax+1) - 2; | |
1336 | last = 1; | |
1337 | } else { | |
1338 | if (last == 0) { | |
1339 | // Sequence Z | |
1340 | ToSend[++ToSendMax] = SEC_Z; | |
1341 | LastProxToAirDuration = 8 * (ToSendMax+1) - 6; | |
1342 | } else { | |
1343 | // Sequence Y | |
1344 | ToSend[++ToSendMax] = SEC_Y; | |
1345 | last = 0; | |
1346 | } | |
1347 | } | |
1348 | b >>= 1; | |
1349 | } | |
1350 | ||
1351 | // Only transmit parity bit if we transmitted a complete byte | |
1352 | if (j == 8 && parity != NULL) { | |
1353 | // Get the parity bit | |
1354 | if (parity[i>>3] & (0x80 >> (i&0x0007))) { | |
1355 | // Sequence X | |
1356 | ToSend[++ToSendMax] = SEC_X; | |
1357 | LastProxToAirDuration = 8 * (ToSendMax+1) - 2; | |
1358 | last = 1; | |
1359 | } else { | |
1360 | if (last == 0) { | |
1361 | // Sequence Z | |
1362 | ToSend[++ToSendMax] = SEC_Z; | |
1363 | LastProxToAirDuration = 8 * (ToSendMax+1) - 6; | |
1364 | } else { | |
1365 | // Sequence Y | |
1366 | ToSend[++ToSendMax] = SEC_Y; | |
1367 | last = 0; | |
1368 | } | |
1369 | } | |
1370 | } | |
1371 | } | |
1372 | ||
1373 | // End of Communication: Logic 0 followed by Sequence Y | |
1374 | if (last == 0) { | |
1375 | // Sequence Z | |
1376 | ToSend[++ToSendMax] = SEC_Z; | |
1377 | LastProxToAirDuration = 8 * (ToSendMax+1) - 6; | |
1378 | } else { | |
1379 | // Sequence Y | |
1380 | ToSend[++ToSendMax] = SEC_Y; | |
1381 | last = 0; | |
1382 | } | |
1383 | ToSend[++ToSendMax] = SEC_Y; | |
1384 | ||
1385 | // Convert to length of command: | |
1386 | ToSendMax++; | |
1387 | } | |
1388 | ||
1389 | ||
1390 | //----------------------------------------------------------------------------- | |
1391 | // Wait for commands from reader | |
1392 | // Stop when button is pressed (return 1) or field was gone (return 2) | |
1393 | // Or return 0 when command is captured | |
1394 | //----------------------------------------------------------------------------- | |
1395 | int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity) | |
1396 | { | |
1397 | *len = 0; | |
1398 | ||
1399 | uint32_t timer = 0, vtime = 0; | |
1400 | int analogCnt = 0; | |
1401 | int analogAVG = 0; | |
1402 | ||
1403 | // Set ADC to read field strength | |
1404 | AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST; | |
1405 | AT91C_BASE_ADC->ADC_MR = | |
1406 | ADC_MODE_PRESCALE(63) | | |
1407 | ADC_MODE_STARTUP_TIME(1) | | |
1408 | ADC_MODE_SAMPLE_HOLD_TIME(15); | |
1409 | AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF_LOW); | |
1410 | // start ADC | |
1411 | AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START; | |
1412 | ||
1413 | // Run a 'software UART' on the stream of incoming samples. | |
1414 | UartInit(received, parity); | |
1415 | ||
1416 | // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN | |
1417 | do { | |
1418 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
1419 | AT91C_BASE_SSC->SSC_THR = SEC_F; | |
1420 | uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; (void) b; | |
1421 | } | |
1422 | } while (GetCountSspClk() < LastTimeProxToAirStart + LastProxToAirDuration + (FpgaSendQueueDelay>>3)); | |
1423 | ||
1424 | // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen | |
1425 | // only, since we are receiving, not transmitting). | |
1426 | // Signal field is off with the appropriate LED | |
1427 | LED_D_OFF(); | |
1428 | FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN); | |
1429 | ||
1430 | for(;;) { | |
1431 | WDT_HIT(); | |
1432 | ||
1433 | if (BUTTON_PRESS()) return 1; | |
1434 | ||
1435 | // test if the field exists | |
1436 | if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF_LOW)) { | |
1437 | analogCnt++; | |
1438 | analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF_LOW]; | |
1439 | AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START; | |
1440 | if (analogCnt >= 32) { | |
1441 | if ((MAX_ADC_HF_VOLTAGE_LOW * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) { | |
1442 | vtime = GetTickCount(); | |
1443 | if (!timer) timer = vtime; | |
1444 | // 50ms no field --> card to idle state | |
1445 | if (vtime - timer > 50) return 2; | |
1446 | } else | |
1447 | if (timer) timer = 0; | |
1448 | analogCnt = 0; | |
1449 | analogAVG = 0; | |
1450 | } | |
1451 | } | |
1452 | ||
1453 | // receive and test the miller decoding | |
1454 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { | |
1455 | uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; | |
1456 | if(MillerDecoding(b, 0)) { | |
1457 | *len = Uart.len; | |
1458 | EmLogTraceReader(); | |
1459 | return 0; | |
1460 | } | |
1461 | } | |
1462 | ||
1463 | } | |
1464 | } | |
1465 | ||
1466 | ||
1467 | static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen) | |
1468 | { | |
1469 | uint8_t b; | |
1470 | uint16_t i = 0; | |
1471 | bool correctionNeeded; | |
1472 | ||
1473 | // Modulate Manchester | |
1474 | FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD); | |
1475 | ||
1476 | // include correction bit if necessary | |
1477 | if (Uart.bitCount == 7) | |
1478 | { | |
1479 | // Short tags (7 bits) don't have parity, determine the correct value from MSB | |
1480 | correctionNeeded = Uart.output[0] & 0x40; | |
1481 | } | |
1482 | else | |
1483 | { | |
1484 | // Look at the last parity bit | |
1485 | correctionNeeded = Uart.parity[(Uart.len-1)/8] & (0x80 >> ((Uart.len-1) & 7)); | |
1486 | } | |
1487 | ||
1488 | if(correctionNeeded) { | |
1489 | // 1236, so correction bit needed | |
1490 | i = 0; | |
1491 | } else { | |
1492 | i = 1; | |
1493 | } | |
1494 | ||
1495 | // clear receiving shift register and holding register | |
1496 | while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)); | |
1497 | b = AT91C_BASE_SSC->SSC_RHR; (void) b; | |
1498 | while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)); | |
1499 | b = AT91C_BASE_SSC->SSC_RHR; (void) b; | |
1500 | ||
1501 | // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line) | |
1502 | for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never | |
1503 | while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)); | |
1504 | if (AT91C_BASE_SSC->SSC_RHR) break; | |
1505 | } | |
1506 | ||
1507 | LastTimeProxToAirStart = (GetCountSspClk() & 0xfffffff8) + (correctionNeeded?8:0); | |
1508 | ||
1509 | // send cycle | |
1510 | for(; i < respLen; ) { | |
1511 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { | |
1512 | AT91C_BASE_SSC->SSC_THR = resp[i++]; | |
1513 | FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR; | |
1514 | } | |
1515 | ||
1516 | if(BUTTON_PRESS()) { | |
1517 | break; | |
1518 | } | |
1519 | } | |
1520 | ||
1521 | return 0; | |
1522 | } | |
1523 | ||
1524 | ||
1525 | static int EmSend4bitEx(uint8_t resp){ | |
1526 | Code4bitAnswerAsTag(resp); | |
1527 | int res = EmSendCmd14443aRaw(ToSend, ToSendMax); | |
1528 | // do the tracing for the previous reader request and this tag answer: | |
1529 | EmLogTraceTag(&resp, 1, NULL, LastProxToAirDuration); | |
1530 | return res; | |
1531 | } | |
1532 | ||
1533 | ||
1534 | int EmSend4bit(uint8_t resp){ | |
1535 | return EmSend4bitEx(resp); | |
1536 | } | |
1537 | ||
1538 | ||
1539 | static int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, uint8_t *par){ | |
1540 | CodeIso14443aAsTagPar(resp, respLen, par); | |
1541 | int res = EmSendCmd14443aRaw(ToSend, ToSendMax); | |
1542 | // do the tracing for the previous reader request and this tag answer: | |
1543 | EmLogTraceTag(resp, respLen, par, LastProxToAirDuration); | |
1544 | return res; | |
1545 | } | |
1546 | ||
1547 | ||
1548 | int EmSendCmdEx(uint8_t *resp, uint16_t respLen){ | |
1549 | uint8_t par[MAX_PARITY_SIZE]; | |
1550 | GetParity(resp, respLen, par); | |
1551 | return EmSendCmdExPar(resp, respLen, par); | |
1552 | } | |
1553 | ||
1554 | ||
1555 | int EmSendCmd(uint8_t *resp, uint16_t respLen){ | |
1556 | uint8_t par[MAX_PARITY_SIZE]; | |
1557 | GetParity(resp, respLen, par); | |
1558 | return EmSendCmdExPar(resp, respLen, par); | |
1559 | } | |
1560 | ||
1561 | ||
1562 | int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){ | |
1563 | return EmSendCmdExPar(resp, respLen, par); | |
1564 | } | |
1565 | ||
1566 | ||
1567 | int EmSendPrecompiledCmd(tag_response_info_t *response_info) { | |
1568 | int ret = EmSendCmd14443aRaw(response_info->modulation, response_info->modulation_n); | |
1569 | // do the tracing for the previous reader request and this tag answer: | |
1570 | EmLogTraceTag(response_info->response, response_info->response_n, &(response_info->par), response_info->ProxToAirDuration); | |
1571 | return ret; | |
1572 | } | |
1573 | ||
1574 | ||
1575 | //----------------------------------------------------------------------------- | |
1576 | // Wait a certain time for tag response | |
1577 | // If a response is captured return true | |
1578 | // If it takes too long return false | |
1579 | //----------------------------------------------------------------------------- | |
1580 | static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset) | |
1581 | { | |
1582 | uint32_t c; | |
1583 | ||
1584 | // Set FPGA mode to "reader listen mode", no modulation (listen | |
1585 | // only, since we are receiving, not transmitting). | |
1586 | // Signal field is on with the appropriate LED | |
1587 | LED_D_ON(); | |
1588 | FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN); | |
1589 | ||
1590 | // Now get the answer from the card | |
1591 | DemodInit(receivedResponse, receivedResponsePar); | |
1592 | ||
1593 | // clear RXRDY: | |
1594 | uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; | |
1595 | ||
1596 | c = 0; | |
1597 | for(;;) { | |
1598 | WDT_HIT(); | |
1599 | ||
1600 | if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { | |
1601 | b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; | |
1602 | if(ManchesterDecoding(b, offset, 0)) { | |
1603 | NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD); | |
1604 | return true; | |
1605 | } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) { | |
1606 | return false; | |
1607 | } | |
1608 | } | |
1609 | } | |
1610 | } | |
1611 | ||
1612 | ||
1613 | void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing) | |
1614 | { | |
1615 | CodeIso14443aBitsAsReaderPar(frame, bits, par); | |
1616 | ||
1617 | // Send command to tag | |
1618 | TransmitFor14443a(ToSend, ToSendMax, timing); | |
1619 | if(trigger) | |
1620 | LED_A_ON(); | |
1621 | ||
1622 | // Log reader command in trace buffer | |
1623 | LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, true); | |
1624 | } | |
1625 | ||
1626 | ||
1627 | void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing) | |
1628 | { | |
1629 | ReaderTransmitBitsPar(frame, len*8, par, timing); | |
1630 | } | |
1631 | ||
1632 | ||
1633 | static void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing) | |
1634 | { | |
1635 | // Generate parity and redirect | |
1636 | uint8_t par[MAX_PARITY_SIZE]; | |
1637 | GetParity(frame, len/8, par); | |
1638 | ReaderTransmitBitsPar(frame, len, par, timing); | |
1639 | } | |
1640 | ||
1641 | ||
1642 | void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing) | |
1643 | { | |
1644 | // Generate parity and redirect | |
1645 | uint8_t par[MAX_PARITY_SIZE]; | |
1646 | GetParity(frame, len, par); | |
1647 | ReaderTransmitBitsPar(frame, len*8, par, timing); | |
1648 | } | |
1649 | ||
1650 | ||
1651 | static int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity) | |
1652 | { | |
1653 | if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset)) return false; | |
1654 | LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, false); | |
1655 | return Demod.len; | |
1656 | } | |
1657 | ||
1658 | ||
1659 | int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity) | |
1660 | { | |
1661 | if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0)) return false; | |
1662 | LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, false); | |
1663 | return Demod.len; | |
1664 | } | |
1665 | ||
1666 | ||
1667 | static void iso14a_set_ATS_times(uint8_t *ats) { | |
1668 | ||
1669 | uint8_t tb1; | |
1670 | uint8_t fwi, sfgi; | |
1671 | uint32_t fwt, sfgt; | |
1672 | ||
1673 | if (ats[0] > 1) { // there is a format byte T0 | |
1674 | if ((ats[1] & 0x20) == 0x20) { // there is an interface byte TB(1) | |
1675 | if ((ats[1] & 0x10) == 0x10) { // there is an interface byte TA(1) preceding TB(1) | |
1676 | tb1 = ats[3]; | |
1677 | } else { | |
1678 | tb1 = ats[2]; | |
1679 | } | |
1680 | fwi = (tb1 & 0xf0) >> 4; // frame waiting time integer (FWI) | |
1681 | if (fwi != 15) { | |
1682 | fwt = 256 * 16 * (1 << fwi); // frame waiting time (FWT) in 1/fc | |
1683 | iso14a_set_timeout(fwt/(8*16)); | |
1684 | } | |
1685 | sfgi = tb1 & 0x0f; // startup frame guard time integer (SFGI) | |
1686 | if (sfgi != 0 && sfgi != 15) { | |
1687 | sfgt = 256 * 16 * (1 << sfgi); // startup frame guard time (SFGT) in 1/fc | |
1688 | NextTransferTime = MAX(NextTransferTime, Demod.endTime + (sfgt - DELAY_AIR2ARM_AS_READER - DELAY_ARM2AIR_AS_READER)/16); | |
1689 | } | |
1690 | } | |
1691 | } | |
1692 | } | |
1693 | ||
1694 | ||
1695 | static int GetATQA(uint8_t *resp, uint8_t *resp_par) { | |
1696 | ||
1697 | #define WUPA_RETRY_TIMEOUT 10 // 10ms | |
1698 | uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP | |
1699 | ||
1700 | uint32_t save_iso14a_timeout = iso14a_get_timeout(); | |
1701 | iso14a_set_timeout(1236/(16*8)+1); // response to WUPA is expected at exactly 1236/fc. No need to wait longer. | |
1702 | ||
1703 | uint32_t start_time = GetTickCount(); | |
1704 | int len; | |
1705 | ||
1706 | // we may need several tries if we did send an unknown command or a wrong authentication before... | |
1707 | do { | |
1708 | // Broadcast for a card, WUPA (0x52) will force response from all cards in the field | |
1709 | ReaderTransmitBitsPar(wupa, 7, NULL, NULL); | |
1710 | // Receive the ATQA | |
1711 | len = ReaderReceive(resp, resp_par); | |
1712 | } while (len == 0 && GetTickCount() <= start_time + WUPA_RETRY_TIMEOUT); | |
1713 | ||
1714 | iso14a_set_timeout(save_iso14a_timeout); | |
1715 | return len; | |
1716 | } | |
1717 | ||
1718 | ||
1719 | // performs iso14443a anticollision (optional) and card select procedure | |
1720 | // fills the uid and cuid pointer unless NULL | |
1721 | // fills the card info record unless NULL | |
1722 | // if anticollision is false, then the UID must be provided in uid_ptr[] | |
1723 | // and num_cascades must be set (1: 4 Byte UID, 2: 7 Byte UID, 3: 10 Byte UID) | |
1724 | // requests ATS unless no_rats is true | |
1725 | int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr, bool anticollision, uint8_t num_cascades, bool no_rats) { | |
1726 | uint8_t sel_all[] = { 0x93,0x20 }; | |
1727 | uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00}; | |
1728 | uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0 | |
1729 | uint8_t resp[MAX_FRAME_SIZE]; // theoretically. A usual RATS will be much smaller | |
1730 | uint8_t resp_par[MAX_PARITY_SIZE]; | |
1731 | byte_t uid_resp[4]; | |
1732 | size_t uid_resp_len; | |
1733 | ||
1734 | uint8_t sak = 0x04; // cascade uid | |
1735 | int cascade_level = 0; | |
1736 | int len; | |
1737 | ||
1738 | // init card struct | |
1739 | if(p_hi14a_card) { | |
1740 | p_hi14a_card->uidlen = 0; | |
1741 | memset(p_hi14a_card->uid, 0, 10); | |
1742 | p_hi14a_card->ats_len = 0; | |
1743 | } | |
1744 | ||
1745 | if (!GetATQA(resp, resp_par)) { | |
1746 | return 0; | |
1747 | } | |
1748 | ||
1749 | if(p_hi14a_card) { | |
1750 | memcpy(p_hi14a_card->atqa, resp, 2); | |
1751 | } | |
1752 | ||
1753 | if (anticollision) { | |
1754 | // clear uid | |
1755 | if (uid_ptr) { | |
1756 | memset(uid_ptr,0,10); | |
1757 | } | |
1758 | } | |
1759 | ||
1760 | // check for proprietary anticollision: | |
1761 | if ((resp[0] & 0x1F) == 0) { | |
1762 | return 3; | |
1763 | } | |
1764 | ||
1765 | // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in | |
1766 | // which case we need to make a cascade 2 request and select - this is a long UID | |
1767 | // While the UID is not complete, the 3nd bit (from the right) is set in the SAK. | |
1768 | for(; sak & 0x04; cascade_level++) { | |
1769 | // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97) | |
1770 | sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2; | |
1771 | ||
1772 | if (anticollision) { | |
1773 | // SELECT_ALL | |
1774 | ReaderTransmit(sel_all, sizeof(sel_all), NULL); | |
1775 | if (!ReaderReceive(resp, resp_par)) { | |
1776 | return 0; | |
1777 | } | |
1778 | ||
1779 | if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit | |
1780 | memset(uid_resp, 0, 4); | |
1781 | uint16_t uid_resp_bits = 0; | |
1782 | uint16_t collision_answer_offset = 0; | |
1783 | // anti-collision-loop: | |
1784 | while (Demod.collisionPos) { | |
1785 | Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos); | |
1786 | for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point | |
1787 | uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01; | |
1788 | uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8); | |
1789 | } | |
1790 | uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position | |
1791 | uid_resp_bits++; | |
1792 | // construct anticollosion command: | |
1793 | sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits | |
1794 | for (uint16_t i = 0; i <= uid_resp_bits/8; i++) { | |
1795 | sel_uid[2+i] = uid_resp[i]; | |
1796 | } | |
1797 | collision_answer_offset = uid_resp_bits%8; | |
1798 | ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL); | |
1799 | if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) { | |
1800 | return 0; | |
1801 | } | |
1802 | } | |
1803 | // finally, add the last bits and BCC of the UID | |
1804 | for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) { | |
1805 | uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01; | |
1806 | uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8); | |
1807 | } | |
1808 | ||
1809 | } else { // no collision, use the response to SELECT_ALL as current uid | |
1810 | memcpy(uid_resp, resp, 4); | |
1811 | } | |
1812 | } else { | |
1813 | if (cascade_level < num_cascades - 1) { | |
1814 | uid_resp[0] = 0x88; | |
1815 | memcpy(uid_resp+1, uid_ptr+cascade_level*3, 3); | |
1816 | } else { | |
1817 | memcpy(uid_resp, uid_ptr+cascade_level*3, 4); | |
1818 | } | |
1819 | } | |
1820 | uid_resp_len = 4; | |
1821 | ||
1822 | // calculate crypto UID. Always use last 4 Bytes. | |
1823 | if(cuid_ptr) { | |
1824 | *cuid_ptr = bytes_to_num(uid_resp, 4); | |
1825 | } | |
1826 | ||
1827 | // Construct SELECT UID command | |
1828 | sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC) | |
1829 | memcpy(sel_uid+2, uid_resp, 4); // the UID received during anticollision, or the provided UID | |
1830 | sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC | |
1831 | AppendCrc14443a(sel_uid, 7); // calculate and add CRC | |
1832 | ReaderTransmit(sel_uid, sizeof(sel_uid), NULL); | |
1833 | ||
1834 | // Receive the SAK | |
1835 | if (!ReaderReceive(resp, resp_par)) { | |
1836 | return 0; | |
1837 | } | |
1838 | sak = resp[0]; | |
1839 | ||
1840 | // Test if more parts of the uid are coming | |
1841 | if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) { | |
1842 | // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of: | |
1843 | // http://www.nxp.com/documents/application_note/AN10927.pdf | |
1844 | uid_resp[0] = uid_resp[1]; | |
1845 | uid_resp[1] = uid_resp[2]; | |
1846 | uid_resp[2] = uid_resp[3]; | |
1847 | uid_resp_len = 3; | |
1848 | } | |
1849 | ||
1850 | if(uid_ptr && anticollision) { | |
1851 | memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len); | |
1852 | } | |
1853 | ||
1854 | if(p_hi14a_card) { | |
1855 | memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len); | |
1856 | p_hi14a_card->uidlen += uid_resp_len; | |
1857 | } | |
1858 | } | |
1859 | ||
1860 | if(p_hi14a_card) { | |
1861 | p_hi14a_card->sak = sak; | |
1862 | } | |
1863 | ||
1864 | // PICC compilant with iso14443a-4 ---> (SAK & 0x20 != 0) | |
1865 | if( (sak & 0x20) == 0) return 2; | |
1866 | ||
1867 | if (!no_rats) { | |
1868 | // Request for answer to select | |
1869 | AppendCrc14443a(rats, 2); | |
1870 | ReaderTransmit(rats, sizeof(rats), NULL); | |
1871 | ||
1872 | if (!(len = ReaderReceive(resp, resp_par))) { | |
1873 | return 0; | |
1874 | } | |
1875 | ||
1876 | if(p_hi14a_card) { | |
1877 | memcpy(p_hi14a_card->ats, resp, len); | |
1878 | p_hi14a_card->ats_len = len; | |
1879 | } | |
1880 | ||
1881 | // reset the PCB block number | |
1882 | iso14_pcb_blocknum = 0; | |
1883 | ||
1884 | // set default timeout and delay next transfer based on ATS | |
1885 | iso14a_set_ATS_times(resp); | |
1886 | ||
1887 | } | |
1888 | return 1; | |
1889 | } | |
1890 | ||
1891 | ||
1892 | void iso14443a_setup(uint8_t fpga_minor_mode) { | |
1893 | FpgaDownloadAndGo(FPGA_BITSTREAM_HF); | |
1894 | // Set up the synchronous serial port | |
1895 | FpgaSetupSsc(FPGA_MAJOR_MODE_HF_ISO14443A); | |
1896 | // connect Demodulated Signal to ADC: | |
1897 | SetAdcMuxFor(GPIO_MUXSEL_HIPKD); | |
1898 | ||
1899 | // Signal field is on with the appropriate LED | |
1900 | if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD | |
1901 | || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) { | |
1902 | LED_D_ON(); | |
1903 | } else { | |
1904 | LED_D_OFF(); | |
1905 | } | |
1906 | FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode); | |
1907 | ||
1908 | // Start the timer | |
1909 | StartCountSspClk(); | |
1910 | ||
1911 | DemodReset(); | |
1912 | UartReset(); | |
1913 | NextTransferTime = 2*DELAY_ARM2AIR_AS_READER; | |
1914 | iso14a_set_timeout(1060); // 10ms default | |
1915 | } | |
1916 | ||
1917 | /* Peter Fillmore 2015 | |
1918 | Added card id field to the function | |
1919 | info from ISO14443A standard | |
1920 | b1 = Block Number | |
1921 | b2 = RFU (always 1) | |
1922 | b3 = depends on block | |
1923 | b4 = Card ID following if set to 1 | |
1924 | b5 = depends on block type | |
1925 | b6 = depends on block type | |
1926 | b7,b8 = block type. | |
1927 | Coding of I-BLOCK: | |
1928 | b8 b7 b6 b5 b4 b3 b2 b1 | |
1929 | 0 0 0 x x x 1 x | |
1930 | b5 = chaining bit | |
1931 | Coding of R-block: | |
1932 | b8 b7 b6 b5 b4 b3 b2 b1 | |
1933 | 1 0 1 x x 0 1 x | |
1934 | b5 = ACK/NACK | |
1935 | Coding of S-block: | |
1936 | b8 b7 b6 b5 b4 b3 b2 b1 | |
1937 | 1 1 x x x 0 1 0 | |
1938 | b5,b6 = 00 - DESELECT | |
1939 | 11 - WTX | |
1940 | */ | |
1941 | int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data, uint8_t *res) { | |
1942 | uint8_t parity[MAX_PARITY_SIZE]; | |
1943 | uint8_t real_cmd[cmd_len + 4]; | |
1944 | ||
1945 | if (cmd_len) { | |
1946 | // ISO 14443 APDU frame: PCB [CID] [NAD] APDU CRC PCB=0x02 | |
1947 | real_cmd[0] = 0x02; // bnr,nad,cid,chn=0; i-block(0x00) | |
1948 | // put block number into the PCB | |
1949 | real_cmd[0] |= iso14_pcb_blocknum; | |
1950 | memcpy(real_cmd + 1, cmd, cmd_len); | |
1951 | } else { | |
1952 | // R-block. ACK | |
1953 | real_cmd[0] = 0xA2; // r-block + ACK | |
1954 | real_cmd[0] |= iso14_pcb_blocknum; | |
1955 | } | |
1956 | AppendCrc14443a(real_cmd, cmd_len + 1); | |
1957 | ||
1958 | ReaderTransmit(real_cmd, cmd_len + 3, NULL); | |
1959 | ||
1960 | size_t len = ReaderReceive(data, parity); | |
1961 | uint8_t *data_bytes = (uint8_t *) data; | |
1962 | ||
1963 | if (!len) { | |
1964 | return 0; //DATA LINK ERROR | |
1965 | } else{ | |
1966 | // S-Block WTX | |
1967 | while(len && ((data_bytes[0] & 0xF2) == 0xF2)) { | |
1968 | uint32_t save_iso14a_timeout = iso14a_get_timeout(); | |
1969 | // temporarily increase timeout | |
1970 | iso14a_set_timeout(MAX((data_bytes[1] & 0x3f) * save_iso14a_timeout, MAX_ISO14A_TIMEOUT)); | |
1971 | // Transmit WTX back | |
1972 | // byte1 - WTXM [1..59]. command FWT=FWT*WTXM | |
1973 | data_bytes[1] = data_bytes[1] & 0x3f; // 2 high bits mandatory set to 0b | |
1974 | // now need to fix CRC. | |
1975 | AppendCrc14443a(data_bytes, len - 2); | |
1976 | // transmit S-Block | |
1977 | ReaderTransmit(data_bytes, len, NULL); | |
1978 | // retrieve the result again (with increased timeout) | |
1979 | len = ReaderReceive(data, parity); | |
1980 | data_bytes = data; | |
1981 | // restore timeout | |
1982 | iso14a_set_timeout(save_iso14a_timeout); | |
1983 | } | |
1984 | ||
1985 | // if we received an I- or R(ACK)-Block with a block number equal to the | |
1986 | // current block number, toggle the current block number | |
1987 | if (len >= 3 // PCB+CRC = 3 bytes | |
1988 | && ((data_bytes[0] & 0xC0) == 0 // I-Block | |
1989 | || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0 | |
1990 | && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers | |
1991 | { | |
1992 | iso14_pcb_blocknum ^= 1; | |
1993 | } | |
1994 | ||
1995 | // if we received I-block with chaining we need to send ACK and receive another block of data | |
1996 | if (res) | |
1997 | *res = data_bytes[0]; | |
1998 | ||
1999 | // crc check | |
2000 | if (len >= 3 && !CheckCrc14443(CRC_14443_A, data_bytes, len)) { | |
2001 | return -1; | |
2002 | } | |
2003 | ||
2004 | } | |
2005 | ||
2006 | if (len) { | |
2007 | // cut frame byte | |
2008 | len -= 1; | |
2009 | // memmove(data_bytes, data_bytes + 1, len); | |
2010 | for (int i = 0; i < len; i++) | |
2011 | data_bytes[i] = data_bytes[i + 1]; | |
2012 | } | |
2013 | ||
2014 | return len; | |
2015 | } | |
2016 | ||
2017 | ||
2018 | //----------------------------------------------------------------------------- | |
2019 | // Read an ISO 14443a tag. Send out commands and store answers. | |
2020 | // | |
2021 | //----------------------------------------------------------------------------- | |
2022 | void ReaderIso14443a(UsbCommand *c) | |
2023 | { | |
2024 | iso14a_command_t param = c->arg[0]; | |
2025 | uint8_t *cmd = c->d.asBytes; | |
2026 | size_t len = c->arg[1] & 0xffff; | |
2027 | size_t lenbits = c->arg[1] >> 16; | |
2028 | uint32_t timeout = c->arg[2]; | |
2029 | uint32_t arg0 = 0; | |
2030 | byte_t buf[USB_CMD_DATA_SIZE] = {0}; | |
2031 | uint8_t par[MAX_PARITY_SIZE]; | |
2032 | bool cantSELECT = false; | |
2033 | ||
2034 | set_tracing(true); | |
2035 | ||
2036 | if(param & ISO14A_CLEAR_TRACE) { | |
2037 | clear_trace(); | |
2038 | } | |
2039 | ||
2040 | if(param & ISO14A_REQUEST_TRIGGER) { | |
2041 | iso14a_set_trigger(true); | |
2042 | } | |
2043 | ||
2044 | if(param & ISO14A_CONNECT) { | |
2045 | LED_A_ON(); | |
2046 | iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN); | |
2047 | if(!(param & ISO14A_NO_SELECT)) { | |
2048 | iso14a_card_select_t *card = (iso14a_card_select_t*)buf; | |
2049 | arg0 = iso14443a_select_card(NULL, card, NULL, true, 0, param & ISO14A_NO_RATS); | |
2050 | ||
2051 | // if we cant select then we cant send data | |
2052 | if (arg0 != 1 && arg0 != 2) { | |
2053 | // 1 - all is OK with ATS, 2 - without ATS | |
2054 | cantSELECT = true; | |
2055 | } | |
2056 | FpgaDisableTracing(); | |
2057 | LED_B_ON(); | |
2058 | cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t)); | |
2059 | LED_B_OFF(); | |
2060 | } | |
2061 | } | |
2062 | ||
2063 | if(param & ISO14A_SET_TIMEOUT) { | |
2064 | iso14a_set_timeout(timeout); | |
2065 | } | |
2066 | ||
2067 | if(param & ISO14A_APDU && !cantSELECT) { | |
2068 | uint8_t res; | |
2069 | arg0 = iso14_apdu(cmd, len, buf, &res); | |
2070 | FpgaDisableTracing(); | |
2071 | LED_B_ON(); | |
2072 | cmd_send(CMD_ACK, arg0, res, 0, buf, sizeof(buf)); | |
2073 | LED_B_OFF(); | |
2074 | } | |
2075 | ||
2076 | if(param & ISO14A_RAW && !cantSELECT) { | |
2077 | if(param & ISO14A_APPEND_CRC) { | |
2078 | if(param & ISO14A_TOPAZMODE) { | |
2079 | AppendCrc14443b(cmd,len); | |
2080 | } else { | |
2081 | AppendCrc14443a(cmd,len); | |
2082 | } | |
2083 | len += 2; | |
2084 | if (lenbits) lenbits += 16; | |
2085 | } | |
2086 | if(lenbits>0) { // want to send a specific number of bits (e.g. short commands) | |
2087 | if(param & ISO14A_TOPAZMODE) { | |
2088 | int bits_to_send = lenbits; | |
2089 | uint16_t i = 0; | |
2090 | ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL); // first byte is always short (7bits) and no parity | |
2091 | bits_to_send -= 7; | |
2092 | while (bits_to_send > 0) { | |
2093 | ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL); // following bytes are 8 bit and no parity | |
2094 | bits_to_send -= 8; | |
2095 | } | |
2096 | } else { | |
2097 | GetParity(cmd, lenbits/8, par); | |
2098 | ReaderTransmitBitsPar(cmd, lenbits, par, NULL); // bytes are 8 bit with odd parity | |
2099 | } | |
2100 | } else { // want to send complete bytes only | |
2101 | if(param & ISO14A_TOPAZMODE) { | |
2102 | uint16_t i = 0; | |
2103 | ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL); // first byte: 7 bits, no paritiy | |
2104 | while (i < len) { | |
2105 | ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL); // following bytes: 8 bits, no paritiy | |
2106 | } | |
2107 | } else { | |
2108 | ReaderTransmit(cmd,len, NULL); // 8 bits, odd parity | |
2109 | } | |
2110 | } | |
2111 | arg0 = ReaderReceive(buf, par); | |
2112 | FpgaDisableTracing(); | |
2113 | ||
2114 | LED_B_ON(); | |
2115 | cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf)); | |
2116 | LED_B_OFF(); | |
2117 | } | |
2118 | ||
2119 | if(param & ISO14A_REQUEST_TRIGGER) { | |
2120 | iso14a_set_trigger(false); | |
2121 | } | |
2122 | ||
2123 | if(param & ISO14A_NO_DISCONNECT) { | |
2124 | return; | |
2125 | } | |
2126 | ||
2127 | FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); | |
2128 | LEDsoff(); | |
2129 | } | |
2130 | ||
2131 | ||
2132 | // Determine the distance between two nonces. | |
2133 | // Assume that the difference is small, but we don't know which is first. | |
2134 | // Therefore try in alternating directions. | |
2135 | static int32_t dist_nt(uint32_t nt1, uint32_t nt2) { | |
2136 | ||
2137 | uint16_t i; | |
2138 | uint32_t nttmp1, nttmp2; | |
2139 | ||
2140 | if (nt1 == nt2) return 0; | |
2141 | ||
2142 | nttmp1 = nt1; | |
2143 | nttmp2 = nt2; | |
2144 | ||
2145 | for (i = 1; i < 32768; i++) { | |
2146 | nttmp1 = prng_successor(nttmp1, 1); | |
2147 | if (nttmp1 == nt2) return i; | |
2148 | nttmp2 = prng_successor(nttmp2, 1); | |
2149 | if (nttmp2 == nt1) return -i; | |
2150 | } | |
2151 | ||
2152 | return(-99999); // either nt1 or nt2 are invalid nonces | |
2153 | } | |
2154 | ||
2155 | ||
2156 | //----------------------------------------------------------------------------- | |
2157 | // Recover several bits of the cypher stream. This implements (first stages of) | |
2158 | // the algorithm described in "The Dark Side of Security by Obscurity and | |
2159 | // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime" | |
2160 | // (article by Nicolas T. Courtois, 2009) | |
2161 | //----------------------------------------------------------------------------- | |
2162 | void ReaderMifare(bool first_try) | |
2163 | { | |
2164 | // Mifare AUTH | |
2165 | uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b }; | |
2166 | uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }; | |
2167 | static uint8_t mf_nr_ar3; | |
2168 | ||
2169 | uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE]; | |
2170 | uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE]; | |
2171 | ||
2172 | iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD); | |
2173 | ||
2174 | // free eventually allocated BigBuf memory. We want all for tracing. | |
2175 | BigBuf_free(); | |
2176 | ||
2177 | clear_trace(); | |
2178 | set_tracing(true); | |
2179 | ||
2180 | uint8_t nt_diff = 0; | |
2181 | uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough | |
2182 | static uint8_t par_low = 0; | |
2183 | bool led_on = true; | |
2184 | uint8_t uid[10] ={0}; | |
2185 | uint32_t cuid; | |
2186 | ||
2187 | uint32_t nt = 0; | |
2188 | uint32_t previous_nt = 0; | |
2189 | static uint32_t nt_attacked = 0; | |
2190 | uint8_t par_list[8] = {0x00}; | |
2191 | uint8_t ks_list[8] = {0x00}; | |
2192 | ||
2193 | #define PRNG_SEQUENCE_LENGTH (1 << 16); | |
2194 | uint32_t sync_time = GetCountSspClk() & 0xfffffff8; | |
2195 | static int32_t sync_cycles; | |
2196 | int catch_up_cycles = 0; | |
2197 | int last_catch_up = 0; | |
2198 | uint16_t elapsed_prng_sequences; | |
2199 | uint16_t consecutive_resyncs = 0; | |
2200 | int isOK = 0; | |
2201 | ||
2202 | if (first_try) { | |
2203 | mf_nr_ar3 = 0; | |
2204 | par[0] = par_low = 0; | |
2205 | sync_cycles = PRNG_SEQUENCE_LENGTH; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the tag nonces). | |
2206 | nt_attacked = 0; | |
2207 | } | |
2208 | else { | |
2209 | // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same) | |
2210 | mf_nr_ar3++; | |
2211 | mf_nr_ar[3] = mf_nr_ar3; | |
2212 | par[0] = par_low; | |
2213 | } | |
2214 | ||
2215 | LED_A_ON(); | |
2216 | LED_B_OFF(); | |
2217 | LED_C_OFF(); | |
2218 | ||
2219 | ||
2220 | #define MAX_UNEXPECTED_RANDOM 4 // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up. | |
2221 | #define MAX_SYNC_TRIES 32 | |
2222 | #define SYNC_TIME_BUFFER 16 // if there is only SYNC_TIME_BUFFER left before next planned sync, wait for next PRNG cycle | |
2223 | #define NUM_DEBUG_INFOS 8 // per strategy | |
2224 | #define MAX_STRATEGY 3 | |
2225 | uint16_t unexpected_random = 0; | |
2226 | uint16_t sync_tries = 0; | |
2227 | int16_t debug_info_nr = -1; | |
2228 | uint16_t strategy = 0; | |
2229 | int32_t debug_info[MAX_STRATEGY][NUM_DEBUG_INFOS]; | |
2230 | uint32_t select_time; | |
2231 | uint32_t halt_time; | |
2232 | ||
2233 | for(uint16_t i = 0; true; i++) { | |
2234 | ||
2235 | LED_C_ON(); | |
2236 | WDT_HIT(); | |
2237 | ||
2238 | // Test if the action was cancelled | |
2239 | if(BUTTON_PRESS()) { | |
2240 | isOK = -1; | |
2241 | break; | |
2242 | } | |
2243 | ||
2244 | if (strategy == 2) { | |
2245 | // test with additional hlt command | |
2246 | halt_time = 0; | |
2247 | int len = mifare_sendcmd_short(NULL, false, 0x50, 0x00, receivedAnswer, receivedAnswerPar, &halt_time); | |
2248 | if (len && MF_DBGLEVEL >= 3) { | |
2249 | Dbprintf("Unexpected response of %d bytes to hlt command (additional debugging).", len); | |
2250 | } | |
2251 | } | |
2252 | ||
2253 | if (strategy == 3) { | |
2254 | // test with FPGA power off/on | |
2255 | FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); | |
2256 | SpinDelay(200); | |
2257 | iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD); | |
2258 | SpinDelay(100); | |
2259 | } | |
2260 | ||
2261 | if(!iso14443a_select_card(uid, NULL, &cuid, true, 0, true)) { | |
2262 | if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card"); | |
2263 | continue; | |
2264 | } | |
2265 | select_time = GetCountSspClk(); | |
2266 | ||
2267 | elapsed_prng_sequences = 1; | |
2268 | if (debug_info_nr == -1) { | |
2269 | sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles; | |
2270 | catch_up_cycles = 0; | |
2271 | ||
2272 | // if we missed the sync time already or are about to miss it, advance to the next nonce repeat | |
2273 | while(sync_time < GetCountSspClk() + SYNC_TIME_BUFFER) { | |
2274 | elapsed_prng_sequences++; | |
2275 | sync_time = (sync_time & 0xfffffff8) + sync_cycles; | |
2276 | } | |
2277 | ||
2278 | // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked) | |
2279 | ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time); | |
2280 | } else { | |
2281 | // collect some information on tag nonces for debugging: | |
2282 | #define DEBUG_FIXED_SYNC_CYCLES PRNG_SEQUENCE_LENGTH | |
2283 | if (strategy == 0) { | |
2284 | // nonce distances at fixed time after card select: | |
2285 | sync_time = select_time + DEBUG_FIXED_SYNC_CYCLES; | |
2286 | } else if (strategy == 1) { | |
2287 | // nonce distances at fixed time between authentications: | |
2288 | sync_time = sync_time + DEBUG_FIXED_SYNC_CYCLES; | |
2289 | } else if (strategy == 2) { | |
2290 | // nonce distances at fixed time after halt: | |
2291 | sync_time = halt_time + DEBUG_FIXED_SYNC_CYCLES; | |
2292 | } else { | |
2293 | // nonce_distances at fixed time after power on | |
2294 | sync_time = DEBUG_FIXED_SYNC_CYCLES; | |
2295 | } | |
2296 | ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time); | |
2297 | } | |
2298 | ||
2299 | // Receive the (4 Byte) "random" nonce | |
2300 | if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) { | |
2301 | if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce"); | |
2302 | continue; | |
2303 | } | |
2304 | ||
2305 | previous_nt = nt; | |
2306 | nt = bytes_to_num(receivedAnswer, 4); | |
2307 | ||
2308 | // Transmit reader nonce with fake par | |
2309 | ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL); | |
2310 | ||
2311 | if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet | |
2312 | int nt_distance = dist_nt(previous_nt, nt); | |
2313 | if (nt_distance == 0) { | |
2314 | nt_attacked = nt; | |
2315 | } else { | |
2316 | if (nt_distance == -99999) { // invalid nonce received | |
2317 | unexpected_random++; | |
2318 | if (unexpected_random > MAX_UNEXPECTED_RANDOM) { | |
2319 | isOK = -3; // Card has an unpredictable PRNG. Give up | |
2320 | break; | |
2321 | } else { | |
2322 | continue; // continue trying... | |
2323 | } | |
2324 | } | |
2325 | if (++sync_tries > MAX_SYNC_TRIES) { | |
2326 | if (strategy > MAX_STRATEGY || MF_DBGLEVEL < 3) { | |
2327 | isOK = -4; // Card's PRNG runs at an unexpected frequency or resets unexpectedly | |
2328 | break; | |
2329 | } else { // continue for a while, just to collect some debug info | |
2330 | debug_info[strategy][debug_info_nr] = nt_distance; | |
2331 | debug_info_nr++; | |
2332 | if (debug_info_nr == NUM_DEBUG_INFOS) { | |
2333 | strategy++; | |
2334 | debug_info_nr = 0; | |
2335 | } | |
2336 | continue; | |
2337 | } | |
2338 | } | |
2339 | sync_cycles = (sync_cycles - nt_distance/elapsed_prng_sequences); | |
2340 | if (sync_cycles <= 0) { | |
2341 | sync_cycles += PRNG_SEQUENCE_LENGTH; | |
2342 | } | |
2343 | if (MF_DBGLEVEL >= 3) { | |
2344 | Dbprintf("calibrating in cycle %d. nt_distance=%d, elapsed_prng_sequences=%d, new sync_cycles: %d\n", i, nt_distance, elapsed_prng_sequences, sync_cycles); | |
2345 | } | |
2346 | continue; | |
2347 | } | |
2348 | } | |
2349 | ||
2350 | if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again... | |
2351 | catch_up_cycles = -dist_nt(nt_attacked, nt); | |
2352 | if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one. | |
2353 | catch_up_cycles = 0; | |
2354 | continue; | |
2355 | } | |
2356 | catch_up_cycles /= elapsed_prng_sequences; | |
2357 | if (catch_up_cycles == last_catch_up) { | |
2358 | consecutive_resyncs++; | |
2359 | } | |
2360 | else { | |
2361 | last_catch_up = catch_up_cycles; | |
2362 | consecutive_resyncs = 0; | |
2363 | } | |
2364 | if (consecutive_resyncs < 3) { | |
2365 | 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); | |
2366 | } | |
2367 | else { | |
2368 | sync_cycles = sync_cycles + catch_up_cycles; | |
2369 | 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); | |
2370 | last_catch_up = 0; | |
2371 | catch_up_cycles = 0; | |
2372 | consecutive_resyncs = 0; | |
2373 | } | |
2374 | continue; | |
2375 | } | |
2376 | ||
2377 | consecutive_resyncs = 0; | |
2378 | ||
2379 | // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding | |
2380 | if (ReaderReceive(receivedAnswer, receivedAnswerPar)) { | |
2381 | catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer | |
2382 | ||
2383 | if (nt_diff == 0) { | |
2384 | 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 | |
2385 | } | |
2386 | ||
2387 | led_on = !led_on; | |
2388 | if(led_on) LED_B_ON(); else LED_B_OFF(); | |
2389 | ||
2390 | par_list[nt_diff] = SwapBits(par[0], 8); | |
2391 | ks_list[nt_diff] = receivedAnswer[0] ^ 0x05; | |
2392 | ||
2393 | // Test if the information is complete | |
2394 | if (nt_diff == 0x07) { | |
2395 | isOK = 1; | |
2396 | break; | |
2397 | } | |
2398 | ||
2399 | nt_diff = (nt_diff + 1) & 0x07; | |
2400 | mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5); | |
2401 | par[0] = par_low; | |
2402 | } else { | |
2403 | if (nt_diff == 0 && first_try) | |
2404 | { | |
2405 | par[0]++; | |
2406 | if (par[0] == 0x00) { // tried all 256 possible parities without success. Card doesn't send NACK. | |
2407 | isOK = -2; | |
2408 | break; | |
2409 | } | |
2410 | } else { | |
2411 | par[0] = ((par[0] & 0x1F) + 1) | par_low; | |
2412 | } | |
2413 | } | |
2414 | } | |
2415 | ||
2416 | ||
2417 | mf_nr_ar[3] &= 0x1F; | |
2418 | ||
2419 | if (isOK == -4) { | |
2420 | if (MF_DBGLEVEL >= 3) { | |
2421 | for (uint16_t i = 0; i <= MAX_STRATEGY; i++) { | |
2422 | for(uint16_t j = 0; j < NUM_DEBUG_INFOS; j++) { | |
2423 | Dbprintf("collected debug info[%d][%d] = %d", i, j, debug_info[i][j]); | |
2424 | } | |
2425 | } | |
2426 | } | |
2427 | } | |
2428 | ||
2429 | FpgaDisableTracing(); | |
2430 | ||
2431 | uint8_t buf[32]; | |
2432 | memcpy(buf + 0, uid, 4); | |
2433 | num_to_bytes(nt, 4, buf + 4); | |
2434 | memcpy(buf + 8, par_list, 8); | |
2435 | memcpy(buf + 16, ks_list, 8); | |
2436 | memcpy(buf + 24, mf_nr_ar, 8); | |
2437 | ||
2438 | cmd_send(CMD_ACK, isOK, 0, 0, buf, 32); | |
2439 | ||
2440 | // Thats it... | |
2441 | FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); | |
2442 | LEDsoff(); | |
2443 | ||
2444 | set_tracing(false); | |
2445 | } | |
2446 | ||
2447 | ||
2448 | //----------------------------------------------------------------------------- | |
2449 | // MIFARE sniffer. | |
2450 | // | |
2451 | //----------------------------------------------------------------------------- | |
2452 | void RAMFUNC SniffMifare(uint8_t param) { | |
2453 | // param: | |
2454 | // bit 0 - trigger from first card answer | |
2455 | // bit 1 - trigger from first reader 7-bit request | |
2456 | ||
2457 | // C(red) A(yellow) B(green) | |
2458 | LEDsoff(); | |
2459 | // init trace buffer | |
2460 | clear_trace(); | |
2461 | set_tracing(true); | |
2462 | ||
2463 | // The command (reader -> tag) that we're receiving. | |
2464 | // The length of a received command will in most cases be no more than 18 bytes. | |
2465 | // So 32 should be enough! | |
2466 | uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE]; | |
2467 | uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE]; | |
2468 | // The response (tag -> reader) that we're receiving. | |
2469 | uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE]; | |
2470 | uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE]; | |
2471 | ||
2472 | iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER); | |
2473 | ||
2474 | // free eventually allocated BigBuf memory | |
2475 | BigBuf_free(); | |
2476 | // allocate the DMA buffer, used to stream samples from the FPGA | |
2477 | uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE); | |
2478 | uint8_t *data = dmaBuf; | |
2479 | uint8_t previous_data = 0; | |
2480 | int maxDataLen = 0; | |
2481 | int dataLen = 0; | |
2482 | bool ReaderIsActive = false; | |
2483 | bool TagIsActive = false; | |
2484 | ||
2485 | // Set up the demodulator for tag -> reader responses. | |
2486 | DemodInit(receivedResponse, receivedResponsePar); | |
2487 | ||
2488 | // Set up the demodulator for the reader -> tag commands | |
2489 | UartInit(receivedCmd, receivedCmdPar); | |
2490 | ||
2491 | // Setup for the DMA. | |
2492 | FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer. | |
2493 | ||
2494 | LED_D_OFF(); | |
2495 | ||
2496 | // init sniffer | |
2497 | MfSniffInit(); | |
2498 | ||
2499 | // And now we loop, receiving samples. | |
2500 | for(uint32_t sniffCounter = 0; true; ) { | |
2501 | ||
2502 | if(BUTTON_PRESS()) { | |
2503 | DbpString("Canceled by button."); | |
2504 | break; | |
2505 | } | |
2506 | ||
2507 | LED_A_ON(); | |
2508 | WDT_HIT(); | |
2509 | ||
2510 | if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time | |
2511 | // check if a transaction is completed (timeout after 2000ms). | |
2512 | // if yes, stop the DMA transfer and send what we have so far to the client | |
2513 | if (MfSniffSend(2000)) { | |
2514 | // Reset everything - we missed some sniffed data anyway while the DMA was stopped | |
2515 | sniffCounter = 0; | |
2516 | data = dmaBuf; | |
2517 | maxDataLen = 0; | |
2518 | ReaderIsActive = false; | |
2519 | TagIsActive = false; | |
2520 | FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer. | |
2521 | } | |
2522 | } | |
2523 | ||
2524 | int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far | |
2525 | int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred | |
2526 | if (readBufDataP <= dmaBufDataP){ // we are processing the same block of data which is currently being transferred | |
2527 | dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed | |
2528 | } else { | |
2529 | dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed | |
2530 | } | |
2531 | // test for length of buffer | |
2532 | if(dataLen > maxDataLen) { // we are more behind than ever... | |
2533 | maxDataLen = dataLen; | |
2534 | if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) { | |
2535 | Dbprintf("blew circular buffer! dataLen=0x%x", dataLen); | |
2536 | break; | |
2537 | } | |
2538 | } | |
2539 | if(dataLen < 1) continue; | |
2540 | ||
2541 | // primary buffer was stopped ( <-- we lost data! | |
2542 | if (!AT91C_BASE_PDC_SSC->PDC_RCR) { | |
2543 | AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf; | |
2544 | AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE; | |
2545 | Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary | |
2546 | } | |
2547 | // secondary buffer sets as primary, secondary buffer was stopped | |
2548 | if (!AT91C_BASE_PDC_SSC->PDC_RNCR) { | |
2549 | AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; | |
2550 | AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE; | |
2551 | } | |
2552 | ||
2553 | LED_A_OFF(); | |
2554 | ||
2555 | if (sniffCounter & 0x01) { | |
2556 | ||
2557 | if(!TagIsActive) { // no need to try decoding tag data if the reader is sending | |
2558 | uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4); | |
2559 | if(MillerDecoding(readerdata, (sniffCounter-1)*4)) { | |
2560 | LED_B_ON(); | |
2561 | LED_C_OFF(); | |
2562 | ||
2563 | if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, true)) break; | |
2564 | ||
2565 | /* And ready to receive another command. */ | |
2566 | UartInit(receivedCmd, receivedCmdPar); | |
2567 | ||
2568 | /* And also reset the demod code */ | |
2569 | DemodReset(); | |
2570 | } | |
2571 | ReaderIsActive = (Uart.state != STATE_UNSYNCD); | |
2572 | } | |
2573 | ||
2574 | if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending | |
2575 | uint8_t tagdata = (previous_data << 4) | (*data & 0x0F); | |
2576 | if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) { | |
2577 | LED_B_OFF(); | |
2578 | LED_C_ON(); | |
2579 | ||
2580 | if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, false)) break; | |
2581 | ||
2582 | // And ready to receive another response. | |
2583 | DemodReset(); | |
2584 | // And reset the Miller decoder including its (now outdated) input buffer | |
2585 | UartInit(receivedCmd, receivedCmdPar); | |
2586 | } | |
2587 | TagIsActive = (Demod.state != DEMOD_UNSYNCD); | |
2588 | } | |
2589 | } | |
2590 | ||
2591 | previous_data = *data; | |
2592 | sniffCounter++; | |
2593 | data++; | |
2594 | if(data == dmaBuf + DMA_BUFFER_SIZE) { | |
2595 | data = dmaBuf; | |
2596 | } | |
2597 | ||
2598 | } // main cycle | |
2599 | ||
2600 | DbpString("COMMAND FINISHED."); | |
2601 | ||
2602 | FpgaDisableSscDma(); | |
2603 | FpgaDisableTracing(); | |
2604 | MfSniffEnd(); | |
2605 | ||
2606 | Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len); | |
2607 | LEDsoff(); | |
2608 | } |