-
-#define abs(x) ( ((x)<0) ? -(x) : (x) )
-#define max(x,y) ( x<y ? y:x)
-
-int DemodPCF7931(uint8_t **outBlocks) {
- uint8_t BitStream[256];
- uint8_t Blocks[8][16];
- uint8_t *GraphBuffer = (uint8_t *)BigBuf;
- int GraphTraceLen = sizeof(BigBuf);
- int i, j, lastval, bitidx, half_switch;
- int clock = 64;
- int tolerance = clock / 8;
- int pmc, block_done;
- int lc, warnings = 0;
- int num_blocks = 0;
- int lmin=128, lmax=128;
- uint8_t dir;
-
- AcquireRawAdcSamples125k(0);
-
- lmin = 64;
- lmax = 192;
-
- i = 2;
-
- /* Find first local max/min */
- if(GraphBuffer[1] > GraphBuffer[0]) {
- while(i < GraphTraceLen) {
- if( !(GraphBuffer[i] > GraphBuffer[i-1]) && GraphBuffer[i] > lmax)
- break;
- i++;
- }
- dir = 0;
- }
- else {
- while(i < GraphTraceLen) {
- if( !(GraphBuffer[i] < GraphBuffer[i-1]) && GraphBuffer[i] < lmin)
- break;
- i++;
- }
- dir = 1;
- }
-
- lastval = i++;
- half_switch = 0;
- pmc = 0;
- block_done = 0;
-
- for (bitidx = 0; i < GraphTraceLen; i++)
- {
- if ( (GraphBuffer[i-1] > GraphBuffer[i] && dir == 1 && GraphBuffer[i] > lmax) || (GraphBuffer[i-1] < GraphBuffer[i] && dir == 0 && GraphBuffer[i] < lmin))
- {
- lc = i - lastval;
- lastval = i;
-
- // Switch depending on lc length:
- // Tolerance is 1/8 of clock rate (arbitrary)
- if (abs(lc-clock/4) < tolerance) {
- // 16T0
- if((i - pmc) == lc) { /* 16T0 was previous one */
- /* It's a PMC ! */
- i += (128+127+16+32+33+16)-1;
- lastval = i;
- pmc = 0;
- block_done = 1;
- }
- else {
- pmc = i;
- }
- } else if (abs(lc-clock/2) < tolerance) {
- // 32TO
- if((i - pmc) == lc) { /* 16T0 was previous one */
- /* It's a PMC ! */
- i += (128+127+16+32+33)-1;
- lastval = i;
- pmc = 0;
- block_done = 1;
- }
- else if(half_switch == 1) {
- BitStream[bitidx++] = 0;
- half_switch = 0;
- }
- else
- half_switch++;
- } else if (abs(lc-clock) < tolerance) {
- // 64TO
- BitStream[bitidx++] = 1;
- } else {
- // Error
- warnings++;
- if (warnings > 10)
- {
- Dbprintf("Error: too many detection errors, aborting.");
- return 0;
- }
- }
-
- if(block_done == 1) {
- if(bitidx == 128) {
- for(j=0; j<16; j++) {
- Blocks[num_blocks][j] = 128*BitStream[j*8+7]+
- 64*BitStream[j*8+6]+
- 32*BitStream[j*8+5]+
- 16*BitStream[j*8+4]+
- 8*BitStream[j*8+3]+
- 4*BitStream[j*8+2]+
- 2*BitStream[j*8+1]+
- BitStream[j*8];
- }
- num_blocks++;
- }
- bitidx = 0;
- block_done = 0;
- half_switch = 0;
- }
- if (GraphBuffer[i-1] > GraphBuffer[i]) dir=0;
- else dir = 1;
- }
- if(bitidx==255)
- bitidx=0;
- warnings = 0;
- if(num_blocks == 4) break;
- }
- memcpy(outBlocks, Blocks, 16*num_blocks);
- return num_blocks;
-}
-
-int IsBlock0PCF7931(uint8_t *Block) {
- // Assume RFU means 0 :)
- 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
- return 1;
- if((memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) && Block[7] == 0) // PAC disabled, can it *really* happen ?
- return 1;
- return 0;
-}
-
-int IsBlock1PCF7931(uint8_t *Block) {
- // Assume RFU means 0 :)
- if(Block[10] == 0 && Block[11] == 0 && Block[12] == 0 && Block[13] == 0)
- if((Block[14] & 0x7f) <= 9 && Block[15] <= 9)
- return 1;
-
- return 0;
-}
-
-#define ALLOC 16
-
-void ReadPCF7931() {
- uint8_t Blocks[8][17];
- uint8_t tmpBlocks[4][16];
- int i, j, ind, ind2, n;
- int num_blocks = 0;
- int max_blocks = 8;
- int ident = 0;
- int error = 0;
- int tries = 0;
-
- memset(Blocks, 0, 8*17*sizeof(uint8_t));
-
- do {
- memset(tmpBlocks, 0, 4*16*sizeof(uint8_t));
- n = DemodPCF7931((uint8_t**)tmpBlocks);
- if(!n)
- error++;
- if(error==10 && num_blocks == 0) {
- Dbprintf("Error, no tag or bad tag");
- return;
- }
- else if (tries==20 || error==10) {
- Dbprintf("Error reading the tag");
- Dbprintf("Here is the partial content");
- goto end;
- }
-
- for(i=0; i<n; i++)
- Dbprintf("(dbg) %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
- tmpBlocks[i][0], tmpBlocks[i][1], tmpBlocks[i][2], tmpBlocks[i][3], tmpBlocks[i][4], tmpBlocks[i][5], tmpBlocks[i][6], tmpBlocks[i][7],
- tmpBlocks[i][8], tmpBlocks[i][9], tmpBlocks[i][10], tmpBlocks[i][11], tmpBlocks[i][12], tmpBlocks[i][13], tmpBlocks[i][14], tmpBlocks[i][15]);
- if(!ident) {
- for(i=0; i<n; i++) {
- if(IsBlock0PCF7931(tmpBlocks[i])) {
- // Found block 0 ?
- if(i < n-1 && IsBlock1PCF7931(tmpBlocks[i+1])) {
- // Found block 1!
- // \o/
- ident = 1;
- memcpy(Blocks[0], tmpBlocks[i], 16);
- Blocks[0][ALLOC] = 1;
- memcpy(Blocks[1], tmpBlocks[i+1], 16);
- Blocks[1][ALLOC] = 1;
- max_blocks = max((Blocks[1][14] & 0x7f), Blocks[1][15]) + 1;
- // Debug print
- Dbprintf("(dbg) Max blocks: %d", max_blocks);
- num_blocks = 2;
- // Handle following blocks
- for(j=i+2, ind2=2; j!=i; j++, ind2++, num_blocks++) {
- if(j==n) j=0;
- if(j==i) break;
- memcpy(Blocks[ind2], tmpBlocks[j], 16);
- Blocks[ind2][ALLOC] = 1;
- }
- break;
- }
- }
- }
- }
- else {
- for(i=0; i<n; i++) { // Look for identical block in known blocks
- 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
- for(j=0; j<max_blocks; j++) {
- if(Blocks[j][ALLOC] == 1 && !memcmp(tmpBlocks[i], Blocks[j], 16)) {
- // Found an identical block
- for(ind=i-1,ind2=j-1; ind >= 0; ind--,ind2--) {
- if(ind2 < 0)
- ind2 = max_blocks;
- if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
- // Dbprintf("Tmp %d -> Block %d", ind, ind2);
- memcpy(Blocks[ind2], tmpBlocks[ind], 16);
- Blocks[ind2][ALLOC] = 1;
- num_blocks++;
- if(num_blocks == max_blocks) goto end;
- }
- }
- for(ind=i+1,ind2=j+1; ind < n; ind++,ind2++) {
- if(ind2 > max_blocks)
- ind2 = 0;
- if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
- // Dbprintf("Tmp %d -> Block %d", ind, ind2);
- memcpy(Blocks[ind2], tmpBlocks[ind], 16);
- Blocks[ind2][ALLOC] = 1;
- num_blocks++;
- if(num_blocks == max_blocks) goto end;
- }
- }
- }
- }
- }
- }
- }
- tries++;
- if (BUTTON_PRESS()) return;
- } while (num_blocks != max_blocks);
-end:
- Dbprintf("-----------------------------------------");
- Dbprintf("Memory content:");
- Dbprintf("-----------------------------------------");
- for(i=0; i<max_blocks; i++) {
- if(Blocks[i][ALLOC]==1)
- Dbprintf("%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
- Blocks[i][0], Blocks[i][1], Blocks[i][2], Blocks[i][3], Blocks[i][4], Blocks[i][5], Blocks[i][6], Blocks[i][7],
- Blocks[i][8], Blocks[i][9], Blocks[i][10], Blocks[i][11], Blocks[i][12], Blocks[i][13], Blocks[i][14], Blocks[i][15]);
- else
- Dbprintf("<missing block %d>", i);
- }
- Dbprintf("-----------------------------------------");
-
- return ;
-}
-
-
projects / proxmark3-svn / blobdiff