]> cvs.zerfleddert.de Git - proxmark3-svn/blob - armsrc/pcf7931.c
projects / proxmark3-svn / blob
? search:


4d45a69cfe5e94fc721286f6e06cdaf2ebca5b5e
[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 #define abs(x) ( ((x)<0) ? -(x) : (x) )
11 #define max(x,y) ( x<y ? y:x)
12
13 int DemodPCF7931(uint8_t **outBlocks) {
14
15 uint8_t bits[256] = {0x00};
16 uint8_t blocks[8][16];
17 uint8_t *dest = BigBuf_get_addr();
18
19 int GraphTraceLen = BigBuf_max_traceLen();
20 if ( GraphTraceLen > 18000 )
21 GraphTraceLen = 18000;
22
23 int i, j, lastval, bitidx, half_switch;
24 int clock = 64;
25 int tolerance = clock / 8;
26 int pmc, block_done;
27 int lc, warnings = 0;
28 int num_blocks = 0;
29 int lmin=128, lmax=128;
30 uint8_t dir;
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 &&
155 Block[11] == 0 &&
156 Block[12] == 0 &&
157 Block[13] == 0)
158 if ( (Block[14] & 0x7f) <= 9 && Block[15] <= 9)
159 return 1;
160 return 0;
161 }
162
163 void ReadPCF7931() {
164 uint8_t Blocks[8][17];
165 uint8_t tmpBlocks[4][16];
166 int i, j, ind, ind2, n;
167 int num_blocks = 0;
168 int max_blocks = 8;
169 int ident = 0;
170 int error = 0;
171 int tries = 0;
172
173 memset(Blocks, 0, 8*17*sizeof(uint8_t));
174
175 do {
176 memset(tmpBlocks, 0, 4*16*sizeof(uint8_t));
177 n = DemodPCF7931((uint8_t**)tmpBlocks);
178 if(!n)
179 error++;
180 if(error==10 && num_blocks == 0) {
181 Dbprintf("Error, no tag or bad tag");
182 return;
183 }
184 else if (tries==20 || error==10) {
185 Dbprintf("Error reading the tag");
186 Dbprintf("Here is the partial content");
187 goto end;
188 }
189
190 for(i=0; i<n; i++)
191 Dbprintf("(dbg) %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
192 tmpBlocks[i][0], tmpBlocks[i][1], tmpBlocks[i][2], tmpBlocks[i][3], tmpBlocks[i][4], tmpBlocks[i][5], tmpBlocks[i][6], tmpBlocks[i][7],
193 tmpBlocks[i][8], tmpBlocks[i][9], tmpBlocks[i][10], tmpBlocks[i][11], tmpBlocks[i][12], tmpBlocks[i][13], tmpBlocks[i][14], tmpBlocks[i][15]);
194 if(!ident) {
195 for(i=0; i<n; i++) {
196 if(IsBlock0PCF7931(tmpBlocks[i])) {
197 // Found block 0 ?
198 if(i < n-1 && IsBlock1PCF7931(tmpBlocks[i+1])) {
199 // Found block 1!
200 // \o/
201 ident = 1;
202 memcpy(Blocks[0], tmpBlocks[i], 16);
203 Blocks[0][ALLOC] = 1;
204 memcpy(Blocks[1], tmpBlocks[i+1], 16);
205 Blocks[1][ALLOC] = 1;
206 max_blocks = max((Blocks[1][14] & 0x7f), Blocks[1][15]) + 1;
207 // Debug print
208 Dbprintf("(dbg) Max blocks: %d", max_blocks);
209 num_blocks = 2;
210 // Handle following blocks
211 for(j=i+2, ind2=2; j!=i; j++, ind2++, num_blocks++) {
212 if(j==n) j=0;
213 if(j==i) break;
214 memcpy(Blocks[ind2], tmpBlocks[j], 16);
215 Blocks[ind2][ALLOC] = 1;
216 }
217 break;
218 }
219 }
220 }
221 }
222 else {
223 for(i=0; i<n; i++) { // Look for identical block in known blocks
224 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
225 for(j=0; j<max_blocks; j++) {
226 if(Blocks[j][ALLOC] == 1 && !memcmp(tmpBlocks[i], Blocks[j], 16)) {
227 // Found an identical block
228 for(ind=i-1,ind2=j-1; ind >= 0; ind--,ind2--) {
229 if(ind2 < 0)
230 ind2 = max_blocks;
231 if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
232 // Dbprintf("Tmp %d -> Block %d", ind, ind2);
233 memcpy(Blocks[ind2], tmpBlocks[ind], 16);
234 Blocks[ind2][ALLOC] = 1;
235 num_blocks++;
236 if(num_blocks == max_blocks) goto end;
237 }
238 }
239 for(ind=i+1,ind2=j+1; ind < n; ind++,ind2++) {
240 if(ind2 > max_blocks)
241 ind2 = 0;
242 if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
243 // Dbprintf("Tmp %d -> Block %d", ind, ind2);
244 memcpy(Blocks[ind2], tmpBlocks[ind], 16);
245 Blocks[ind2][ALLOC] = 1;
246 num_blocks++;
247 if(num_blocks == max_blocks) goto end;
248 }
249 }
250 }
251 }
252 }
253 }
254 }
255 tries++;
256 if (BUTTON_PRESS()) return;
257 } while (num_blocks != max_blocks);
258 end:
259 Dbprintf("-----------------------------------------");
260 Dbprintf("Memory content:");
261 Dbprintf("-----------------------------------------");
262 for(i=0; i<max_blocks; i++) {
263 if(Blocks[i][ALLOC]==1)
264 Dbprintf("%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
265 Blocks[i][0], Blocks[i][1], Blocks[i][2], Blocks[i][3], Blocks[i][4], Blocks[i][5], Blocks[i][6], Blocks[i][7],
266 Blocks[i][8], Blocks[i][9], Blocks[i][10], Blocks[i][11], Blocks[i][12], Blocks[i][13], Blocks[i][14], Blocks[i][15]);
267 else
268 Dbprintf("<missing block %d>", i);
269 }
270 Dbprintf("-----------------------------------------");
271
272 cmd_send(CMD_ACK,0,0,0,0,0);
273 }
274
275
276 /* Write on a byte of a PCF7931 tag
277 * @param address : address of the block to write
278 @param byte : address of the byte to write
279 @param data : data to write
280 */
281 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)
282 {
283 uint32_t tab[1024] = {0}; // data times frame
284 uint32_t u = 0;
285 uint8_t parity = 0;
286 bool comp = 0;
287
288 //BUILD OF THE DATA FRAME
289
290 //alimentation of the tag (time for initializing)
291 AddPatternPCF7931(init_delay, 0, 8192/2*T0_PCF, tab);
292
293 //PMC
294 Dbprintf("Initialization delay : %d us", init_delay);
295 AddPatternPCF7931(8192/2*T0_PCF + 319*T0_PCF+70, 3*T0_PCF, 29*T0_PCF, tab);
296
297 Dbprintf("Offsets : %d us on the low pulses width, %d us on the low pulses positions", l, p);
298
299 //password indication bit
300 AddBitPCF7931(1, tab, l, p);
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
313 //programming mode (0 or 1)
314 AddBitPCF7931(0, tab, l, p);
315
316 //block adress on 6 bits
317 Dbprintf("Block address : %02x", address);
318 for (u=0; u<6; u++)
319 {
320 if (address&(1<<u)) { // bit 1
321 parity++;
322 AddBitPCF7931(1, tab, l, p);
323 } else{ // bit 0
324 AddBitPCF7931(0, tab, l, p);
325 }
326 }
327
328 //byte address on 4 bits
329 Dbprintf("Byte address : %02x", byte);
330 for (u=0; u<4; u++)
331 {
332 if (byte&(1<<u)) { // bit 1
333 parity++;
334 AddBitPCF7931(1, tab, l, p);
335 } else{ // bit 0
336 AddBitPCF7931(0, tab, l, p);
337 }
338 }
339
340 //data on 8 bits
341 Dbprintf("Data : %02x", data);
342 for (u=0; u<8; u++)
343 {
344 if (data&(1<<u)) { // bit 1
345 parity++;
346 AddBitPCF7931(1, tab, l, p);
347 } else{ //bit 0
348 AddBitPCF7931(0, tab, l, p);
349 }
350 }
351
352
353 //parity bit
354 if((parity%2)==0){
355 AddBitPCF7931(0, tab, l, p); //even parity
356 }else{
357 AddBitPCF7931(1, tab, l, p);//odd parity
358 }
359
360 //time access memory
361 AddPatternPCF7931(5120+2680, 0, 0, tab);
362
363 //conversion of the scale time
364 for(u=0;u<500;u++){
365 tab[u]=(tab[u] * 3)/2;
366 }
367
368 //compensation 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, tempo=0;
390
391 Dbprintf("Sending data frame...");
392
393 FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
394
395 FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
396
397 FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU );
398
399 LED_A_ON();
400
401 // steal this pin from the SSP and use it to control the modulation
402 AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
403 AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
404
405 //initialization of the timer
406 AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14);
407 AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
408 AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
409 AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK; //clock at 48/32 MHz
410 AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN;
411 AT91C_BASE_TCB->TCB_BCR = 1;
412
413
414 tempo = AT91C_BASE_TC0->TC_CV;
415 for( u = 0; tab[u] != 0; u += 3){
416
417 // modulate antenna
418 HIGH(GPIO_SSC_DOUT);
419 while(tempo != tab[u]) tempo = AT91C_BASE_TC0->TC_CV;
420
421 // stop modulating antenna
422 LOW(GPIO_SSC_DOUT);
423 while(tempo != tab[u+1]) tempo = AT91C_BASE_TC0->TC_CV;
424
425 // modulate antenna
426 HIGH(GPIO_SSC_DOUT);
427 while(tempo != tab[u+2]) tempo = AT91C_BASE_TC0->TC_CV;
428 }
429
430 LED_A_OFF();
431 FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
432 SpinDelay(200);
433
434 AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
435 LED(0xFFFF, 1000);
436 }
437
438
439 /* Add a byte for building the data frame of PCF7931 tags
440 * @param b : byte to add
441 * @param tab : array of the data frame
442 * @param l : offset on low pulse width
443 * @param p : offset on low pulse positioning
444 */
445
446 bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p){
447
448 uint32_t u;
449 for ( u=0; u<8; u++)
450 {
451 if (byte&(1<<u)) { //bit à 1
452 if( AddBitPCF7931(1, tab, l, p)==1) return 1;
453 } else { //bit à 0
454 if (AddBitPCF7931(0, tab, l, p)==1) return 1;
455 }
456 }
457 return 0;
458 }
459
460 /* Add a bits for building the data frame of PCF7931 tags
461 * @param b : bit to add
462 * @param tab : array of the data frame
463 * @param l : offset on low pulse width
464 * @param p : offset on low pulse positioning
465 */
466 bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p){
467 uint8_t u = 0;
468
469 //we put the cursor at the last value of the array
470 for ( u = 0; tab[u] != 0; u += 3 ) { }
471
472 if ( b == 1 ) { //add a bit 1
473 if ( u == 0 )
474 tab[u] = 34 * T0_PCF + p;
475 else
476 tab[u] = 34 * T0_PCF + tab[u-1] + p;
477
478 tab[u+1] = 6 * T0_PCF + tab[u] + l;
479 tab[u+2] = 88 * T0_PCF + tab[u+1] - l - p;
480 return 0;
481 } else { //add a bit 0
482
483 if ( u == 0 )
484 tab[u] = 98 * T0_PCF + p;
485 else
486 tab[u] = 98 * T0_PCF + tab[u-1] + p;
487
488 tab[u+1] = 6 * T0_PCF + tab[u] + l;
489 tab[u+2] = 24 * T0_PCF + tab[u+1] - l - p;
490 return 0;
491 }
492
493
494 return 1;
495 }
496
497 /* Add a custom pattern in the data frame
498 * @param a : delay of the first high pulse
499 * @param b : delay of the low pulse
500 * @param c : delay of the last high pulse
501 * @param tab : array of the data frame
502 */
503 bool AddPatternPCF7931(uint32_t a, uint32_t b, uint32_t c, uint32_t * tab){
504 uint32_t u = 0;
505 for(u = 0; tab[u] != 0; u += 3){} //we put the cursor at the last value of the array
506
507 tab[u] = (u == 0) ? a : a + tab[u-1];
508 tab[u+1] = b + tab[u];
509 tab[u+2] = c + tab[u+1];
510
511 return 0;
512 }
Proxmark3 GIT tracking
Impressum, Datenschutz