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[proxmark3-svn] / armsrc / pcf7931.c
1 #include "proxmark3.h"
2 #include "apps.h"
3 #include "lfsampling.h"
4 #include "pcf7931.h"
5 #include "string.h"
6
7 #define T0_PCF 8 //period for the pcf7931 in us
8 #define ALLOC 16
9
10 int DemodPCF7931(uint8_t **outBlocks) {
11
12 uint8_t bits[256] = {0x00};
13 uint8_t blocks[8][16];
14 uint8_t *dest = BigBuf_get_addr();
15
16 int GraphTraceLen = BigBuf_max_traceLen();
17 if ( GraphTraceLen > 18000 )
18 GraphTraceLen = 18000;
19
20
21 int i, j, lastval, bitidx, half_switch;
22 int clock = 64;
23 int tolerance = clock / 8;
24 int pmc, block_done;
25 int lc, warnings = 0;
26 int num_blocks = 0;
27 int lmin=128, lmax=128;
28 uint8_t dir;
29 //clear read buffer
30 BigBuf_Clear_keep_EM();
31
32 LFSetupFPGAForADC(95, true);
33 DoAcquisition_default(0, true);
34
35 lmin = 64;
36 lmax = 192;
37
38 i = 2;
39
40 /* Find first local max/min */
41 if(dest[1] > dest[0]) {
42 while(i < GraphTraceLen) {
43 if( !(dest[i] > dest[i-1]) && dest[i] > lmax)
44 break;
45 i++;
46 }
47 dir = 0;
48 }
49 else {
50 while(i < GraphTraceLen) {
51 if( !(dest[i] < dest[i-1]) && dest[i] < lmin)
52 break;
53 i++;
54 }
55 dir = 1;
56 }
57
58 lastval = i++;
59 half_switch = 0;
60 pmc = 0;
61 block_done = 0;
62
63 for (bitidx = 0; i < GraphTraceLen; i++)
64 {
65 if ( (dest[i-1] > dest[i] && dir == 1 && dest[i] > lmax) || (dest[i-1] < dest[i] && dir == 0 && dest[i] < lmin))
66 {
67 lc = i - lastval;
68 lastval = i;
69
70 // Switch depending on lc length:
71 // Tolerance is 1/8 of clock rate (arbitrary)
72 if (ABS(lc-clock/4) < tolerance) {
73 // 16T0
74 if((i - pmc) == lc) { /* 16T0 was previous one */
75 /* It's a PMC ! */
76 i += (128+127+16+32+33+16)-1;
77 lastval = i;
78 pmc = 0;
79 block_done = 1;
80 }
81 else {
82 pmc = i;
83 }
84 } else if (ABS(lc-clock/2) < tolerance) {
85 // 32TO
86 if((i - pmc) == lc) { /* 16T0 was previous one */
87 /* It's a PMC ! */
88 i += (128+127+16+32+33)-1;
89 lastval = i;
90 pmc = 0;
91 block_done = 1;
92 }
93 else if(half_switch == 1) {
94 bits[bitidx++] = 0;
95 half_switch = 0;
96 }
97 else
98 half_switch++;
99 } else if (ABS(lc-clock) < tolerance) {
100 // 64TO
101 bits[bitidx++] = 1;
102 } else {
103 // Error
104 warnings++;
105 if (warnings > 10)
106 {
107 Dbprintf("Error: too many detection errors, aborting.");
108 return 0;
109 }
110 }
111
112 if(block_done == 1) {
113 if(bitidx == 128) {
114 for(j=0; j<16; j++) {
115 blocks[num_blocks][j] = 128*bits[j*8+7]+
116 64*bits[j*8+6]+
117 32*bits[j*8+5]+
118 16*bits[j*8+4]+
119 8*bits[j*8+3]+
120 4*bits[j*8+2]+
121 2*bits[j*8+1]+
122 bits[j*8];
123
124 }
125 num_blocks++;
126 }
127 bitidx = 0;
128 block_done = 0;
129 half_switch = 0;
130 }
131 if(i < GraphTraceLen)
132 dir =(dest[i-1] > dest[i]) ? 0 : 1;
133 }
134 if(bitidx==255)
135 bitidx=0;
136 warnings = 0;
137 if(num_blocks == 4) break;
138 }
139 memcpy(outBlocks, blocks, 16*num_blocks);
140 return num_blocks;
141 }
142
143 int IsBlock0PCF7931(uint8_t *Block) {
144 // Assume RFU means 0 :)
145 if((memcmp(Block, "\x00\x00\x00\x00\x00\x00\x00\x01", 8) == 0) && memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) // PAC enabled
146 return 1;
147 if((memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) && Block[7] == 0) // PAC disabled, can it *really* happen ?
148 return 1;
149 return 0;
150 }
151
152 int IsBlock1PCF7931(uint8_t *Block) {
153 // Assume RFU means 0 :)
154 if(Block[10] == 0 && Block[11] == 0 && Block[12] == 0 && Block[13] == 0)
155 if((Block[14] & 0x7f) <= 9 && Block[15] <= 9)
156 return 1;
157
158 return 0;
159 }
160
161 void ReadPCF7931() {
162 uint8_t Blocks[8][17];
163 uint8_t tmpBlocks[4][16];
164 int i, j, ind, ind2, n;
165 int num_blocks = 0;
166 int max_blocks = 8;
167 int ident = 0;
168 int error = 0;
169 int tries = 0;
170
171 memset(Blocks, 0, 8*17*sizeof(uint8_t));
172
173 do {
174 memset(tmpBlocks, 0, 4*16*sizeof(uint8_t));
175 n = DemodPCF7931((uint8_t**)tmpBlocks);
176 if(!n)
177 error++;
178 if(error==10 && num_blocks == 0) {
179 Dbprintf("Error, no tag or bad tag");
180 return;
181 }
182 else if (tries==20 || error==10) {
183 Dbprintf("Error reading the tag");
184 Dbprintf("Here is the partial content");
185 goto end;
186 }
187
188 for(i=0; i<n; i++)
189 Dbprintf("(dbg) %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
190 tmpBlocks[i][0], tmpBlocks[i][1], tmpBlocks[i][2], tmpBlocks[i][3], tmpBlocks[i][4], tmpBlocks[i][5], tmpBlocks[i][6], tmpBlocks[i][7],
191 tmpBlocks[i][8], tmpBlocks[i][9], tmpBlocks[i][10], tmpBlocks[i][11], tmpBlocks[i][12], tmpBlocks[i][13], tmpBlocks[i][14], tmpBlocks[i][15]);
192 if(!ident) {
193 for(i=0; i<n; i++) {
194 if(IsBlock0PCF7931(tmpBlocks[i])) {
195 // Found block 0 ?
196 if(i < n-1 && IsBlock1PCF7931(tmpBlocks[i+1])) {
197 // Found block 1!
198 // \o/
199 ident = 1;
200 memcpy(Blocks[0], tmpBlocks[i], 16);
201 Blocks[0][ALLOC] = 1;
202 memcpy(Blocks[1], tmpBlocks[i+1], 16);
203 Blocks[1][ALLOC] = 1;
204 max_blocks = MAX((Blocks[1][14] & 0x7f), Blocks[1][15]) + 1;
205 // Debug print
206 Dbprintf("(dbg) Max blocks: %d", max_blocks);
207 num_blocks = 2;
208 // Handle following blocks
209 for(j=i+2, ind2=2; j!=i; j++, ind2++, num_blocks++) {
210 if(j==n) j=0;
211 if(j==i) break;
212 memcpy(Blocks[ind2], tmpBlocks[j], 16);
213 Blocks[ind2][ALLOC] = 1;
214 }
215 break;
216 }
217 }
218 }
219 }
220 else {
221 for(i=0; i<n; i++) { // Look for identical block in known blocks
222 if(memcmp(tmpBlocks[i], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16)) { // Block is not full of 00
223 for(j=0; j<max_blocks; j++) {
224 if(Blocks[j][ALLOC] == 1 && !memcmp(tmpBlocks[i], Blocks[j], 16)) {
225 // Found an identical block
226 for(ind=i-1,ind2=j-1; ind >= 0; ind--,ind2--) {
227 if(ind2 < 0)
228 ind2 = max_blocks;
229 if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
230 // Dbprintf("Tmp %d -> Block %d", ind, ind2);
231 memcpy(Blocks[ind2], tmpBlocks[ind], 16);
232 Blocks[ind2][ALLOC] = 1;
233 num_blocks++;
234 if(num_blocks == max_blocks) goto end;
235 }
236 }
237 for(ind=i+1,ind2=j+1; ind < n; ind++,ind2++) {
238 if(ind2 > max_blocks)
239 ind2 = 0;
240 if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
241 // Dbprintf("Tmp %d -> Block %d", ind, ind2);
242 memcpy(Blocks[ind2], tmpBlocks[ind], 16);
243 Blocks[ind2][ALLOC] = 1;
244 num_blocks++;
245 if(num_blocks == max_blocks) goto end;
246 }
247 }
248 }
249 }
250 }
251 }
252 }
253 tries++;
254 if (BUTTON_PRESS()) return;
255 } while (num_blocks != max_blocks);
256 end:
257 Dbprintf("-----------------------------------------");
258 Dbprintf("Memory content:");
259 Dbprintf("-----------------------------------------");
260 for(i=0; i<max_blocks; i++) {
261 if(Blocks[i][ALLOC]==1)
262 Dbprintf("%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
263 Blocks[i][0], Blocks[i][1], Blocks[i][2], Blocks[i][3], Blocks[i][4], Blocks[i][5], Blocks[i][6], Blocks[i][7],
264 Blocks[i][8], Blocks[i][9], Blocks[i][10], Blocks[i][11], Blocks[i][12], Blocks[i][13], Blocks[i][14], Blocks[i][15]);
265 else
266 Dbprintf("<missing block %d>", i);
267 }
268 Dbprintf("-----------------------------------------");
269
270 cmd_send(CMD_ACK,0,0,0,0,0);
271 }
272
273
274 /* Write on a byte of a PCF7931 tag
275 * @param address : address of the block to write
276 @param byte : address of the byte to write
277 @param data : data to write
278 */
279 void WritePCF7931(uint8_t pass1, uint8_t pass2, uint8_t pass3, uint8_t pass4, uint8_t pass5, uint8_t pass6, uint8_t pass7, uint16_t init_delay, int32_t l, int32_t p, uint8_t address, uint8_t byte, uint8_t data)
280 {
281
282 uint32_t tab[1024]={0}; // data times frame
283 uint32_t u = 0;
284 uint8_t parity = 0;
285 bool comp = 0;
286
287 //BUILD OF THE DATA FRAME
288
289 //alimentation of the tag (time for initializing)
290 AddPatternPCF7931(init_delay, 0, 8192/2*T0_PCF, tab);
291
292 //PMC
293 Dbprintf("Initialization delay : %d us", init_delay);
294 AddPatternPCF7931(8192/2*T0_PCF + 319*T0_PCF+70, 3*T0_PCF, 29*T0_PCF, tab);
295
296 Dbprintf("Offsets : %d us on the low pulses width, %d us on the low pulses positions", l, p);
297
298 //password indication bit
299 AddBitPCF7931(1, tab, l, p);
300
301
302 //password (on 56 bits)
303 Dbprintf("Password (LSB first on each byte) : %02x %02x %02x %02x %02x %02x %02x", pass1,pass2,pass3,pass4,pass5,pass6,pass7);
304 AddBytePCF7931(pass1, tab, l, p);
305 AddBytePCF7931(pass2, tab, l, p);
306 AddBytePCF7931(pass3, tab, l, p);
307 AddBytePCF7931(pass4, tab, l, p);
308 AddBytePCF7931(pass5, tab, l, p);
309 AddBytePCF7931(pass6, tab, l, p);
310 AddBytePCF7931(pass7, tab, l, p);
311
312 //programming mode (0 or 1)
313 AddBitPCF7931(0, tab, l, p);
314
315 //block adress on 6 bits
316 Dbprintf("Block address : %02x", address);
317 for (u=0; u<6; u++)
318 {
319 if (address&(1<<u)) { // bit 1
320 parity++;
321 AddBitPCF7931(1, tab, l, p);
322 } else{ // bit 0
323 AddBitPCF7931(0, tab, l, p);
324 }
325 }
326
327 //byte address on 4 bits
328 Dbprintf("Byte address : %02x", byte);
329 for (u=0; u<4; u++)
330 {
331 if (byte&(1<<u)) { // bit 1
332 parity++;
333 AddBitPCF7931(1, tab, l, p);
334 } else{ // bit 0
335 AddBitPCF7931(0, tab, l, p);
336 }
337 }
338
339 //data on 8 bits
340 Dbprintf("Data : %02x", data);
341 for (u=0; u<8; u++)
342 {
343 if (data&(1<<u)) { // bit 1
344 parity++;
345 AddBitPCF7931(1, tab, l, p);
346 } else{ //bit 0
347 AddBitPCF7931(0, tab, l, p);
348 }
349 }
350
351
352 //parity bit
353 if((parity%2)==0){
354 AddBitPCF7931(0, tab, l, p); //even parity
355 }else{
356 AddBitPCF7931(1, tab, l, p);//odd parity
357 }
358
359 //time access memory
360 AddPatternPCF7931(5120+2680, 0, 0, tab);
361
362 //conversion of the scale time
363 for(u=0;u<500;u++){
364 tab[u]=(tab[u] * 3)/2;
365 }
366
367
368 //compennsation of the counter reload
369 while (!comp){
370 comp = 1;
371 for(u=0;tab[u]!=0;u++){
372 if(tab[u] > 0xFFFF){
373 tab[u] -= 0xFFFF;
374 comp = 0;
375 }
376 }
377 }
378
379 SendCmdPCF7931(tab);
380 }
381
382
383
384 /* Send a trame to a PCF7931 tags
385 * @param tab : array of the data frame
386 */
387
388 void SendCmdPCF7931(uint32_t * tab){
389 uint16_t u=0;
390 uint16_t tempo=0;
391
392 Dbprintf("SENDING DATA FRAME...");
393
394 FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
395
396 FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
397
398 FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU );
399
400 LED_A_ON();
401
402 // steal this pin from the SSP and use it to control the modulation
403 AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
404 AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
405
406 //initialization of the timer
407 AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14);
408 AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
409 AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
410 AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK; //clock at 48/32 MHz
411 AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN;
412 AT91C_BASE_TCB->TCB_BCR = 1;
413
414
415 tempo = AT91C_BASE_TC0->TC_CV;
416 for(u=0;tab[u]!= 0;u+=3){
417
418
419 // modulate antenna
420 HIGH(GPIO_SSC_DOUT);
421 while(tempo != tab[u]){
422 tempo = AT91C_BASE_TC0->TC_CV;
423 }
424
425 // stop modulating antenna
426 LOW(GPIO_SSC_DOUT);
427 while(tempo != tab[u+1]){
428 tempo = AT91C_BASE_TC0->TC_CV;
429 }
430
431
432 // modulate antenna
433 HIGH(GPIO_SSC_DOUT);
434 while(tempo != tab[u+2]){
435 tempo = AT91C_BASE_TC0->TC_CV;
436 }
437
438
439 }
440
441 LED_A_OFF();
442 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
443 SpinDelay(200);
444
445
446 AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
447 DbpString("FINISH !");
448 DbpString("(Could be usefull to send the same trame many times)");
449 LED(0xFFFF, 1000);
450 }
451
452
453 /* Add a byte for building the data frame of PCF7931 tags
454 * @param b : byte to add
455 * @param tab : array of the data frame
456 * @param l : offset on low pulse width
457 * @param p : offset on low pulse positioning
458 */
459
460 bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p){
461
462 uint32_t u;
463 for (u=0; u<8; u++)
464 {
465 if (byte&(1<<u)) { //bit à 1
466 if(AddBitPCF7931(1, tab, l, p)==1)return 1;
467 } else { //bit à 0
468 if(AddBitPCF7931(0, tab, l, p)==1)return 1;
469 }
470 }
471
472 return 0;
473 }
474
475 /* Add a bits for building the data frame of PCF7931 tags
476 * @param b : bit to add
477 * @param tab : array of the data frame
478 * @param l : offset on low pulse width
479 * @param p : offset on low pulse positioning
480 */
481 bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p){
482 uint8_t u = 0;
483
484 for(u=0;tab[u]!=0;u+=3){} //we put the cursor at the last value of the array
485
486
487 if(b==1){ //add a bit 1
488 if(u==0) tab[u] = 34*T0_PCF+p;
489 else tab[u] = 34*T0_PCF+tab[u-1]+p;
490
491 tab[u+1] = 6*T0_PCF+tab[u]+l;
492 tab[u+2] = 88*T0_PCF+tab[u+1]-l-p;
493 return 0;
494 }else{ //add a bit 0
495
496 if(u==0) tab[u] = 98*T0_PCF+p;
497 else tab[u] = 98*T0_PCF+tab[u-1]+p;
498
499 tab[u+1] = 6*T0_PCF+tab[u]+l;
500 tab[u+2] = 24*T0_PCF+tab[u+1]-l-p;
501 return 0;
502 }
503
504
505 return 1;
506 }
507
508 /* Add a custom pattern in the data frame
509 * @param a : delay of the first high pulse
510 * @param b : delay of the low pulse
511 * @param c : delay of the last high pulse
512 * @param tab : array of the data frame
513 */
514 bool AddPatternPCF7931(uint32_t a, uint32_t b, uint32_t c, uint32_t * tab){
515 uint32_t u = 0;
516 for(u=0;tab[u]!=0;u+=3){} //we put the cursor at the last value of the array
517
518 if(u==0) tab[u] = a;
519 else tab[u] = a + tab[u-1];
520
521 tab[u+1] = b+tab[u];
522 tab[u+2] = c+tab[u+1];
523
524 return 0;
525 }
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