mirror of
https://github.com/RfidResearchGroup/proxmark3.git
synced 2024-11-14 13:44:49 +08:00
530 lines
No EOL
14 KiB
C
530 lines
No EOL
14 KiB
C
#include "pcf7931.h"
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#define T0_PCF 8 //period for the pcf7931 in us
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#define ALLOC 16
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size_t DemodPCF7931(uint8_t **outBlocks) {
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uint8_t bits[256] = {0x00};
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uint8_t blocks[8][16];
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uint8_t *dest = BigBuf_get_addr();
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int GraphTraceLen = BigBuf_max_traceLen();
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if ( GraphTraceLen > 18000 )
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GraphTraceLen = 18000;
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int i, j, lastval, bitidx, half_switch;
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int clock = 64;
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int tolerance = clock / 8;
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int pmc, block_done;
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int lc, warnings = 0;
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size_t num_blocks = 0;
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int lmin=128, lmax=128;
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uint8_t dir;
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//clear read buffer
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BigBuf_Clear_keep_EM();
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LFSetupFPGAForADC(95, true);
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DoAcquisition_default(0, true);
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lmin = 64;
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lmax = 192;
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i = 2;
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/* Find first local max/min */
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if(dest[1] > dest[0]) {
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while(i < GraphTraceLen) {
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if( !(dest[i] > dest[i-1]) && dest[i] > lmax)
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break;
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i++;
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}
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dir = 0;
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} else {
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while(i < GraphTraceLen) {
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if( !(dest[i] < dest[i-1]) && dest[i] < lmin)
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break;
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i++;
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}
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dir = 1;
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}
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lastval = i++;
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half_switch = 0;
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pmc = 0;
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block_done = 0;
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for (bitidx = 0; i < GraphTraceLen; i++) {
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if ((dest[i-1] > dest[i] && dir == 1 && dest[i] > lmax) || (dest[i-1] < dest[i] && dir == 0 && dest[i] < lmin)) {
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lc = i - lastval;
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lastval = i;
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// Switch depending on lc length:
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// Tolerance is 1/8 of clock rate (arbitrary)
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if (ABS(lc-clock/4) < tolerance) {
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// 16T0
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if((i - pmc) == lc) { /* 16T0 was previous one */
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/* It's a PMC ! */
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i += (128+127+16+32+33+16)-1;
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lastval = i;
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pmc = 0;
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block_done = 1;
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} else {
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pmc = i;
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}
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} else if (ABS(lc-clock/2) < tolerance) {
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// 32TO
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if((i - pmc) == lc) { /* 16T0 was previous one */
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/* It's a PMC ! */
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i += (128+127+16+32+33)-1;
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lastval = i;
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pmc = 0;
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block_done = 1;
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} else if(half_switch == 1) {
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bits[bitidx++] = 0;
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half_switch = 0;
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}
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else
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half_switch++;
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} else if (ABS(lc-clock) < tolerance) {
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// 64TO
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bits[bitidx++] = 1;
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} else {
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// Error
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if (++warnings > 10) {
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Dbprintf("Error: too many detection errors, aborting.");
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return 0;
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}
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}
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if(block_done == 1) {
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if(bitidx == 128) {
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for(j = 0; j < 16; ++j) {
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blocks[num_blocks][j] =
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128 * bits[j*8 + 7]+
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64*bits[j*8+6]+
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32*bits[j*8+5]+
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16*bits[j*8+4]+
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8*bits[j*8+3]+
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4*bits[j*8+2]+
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2*bits[j*8+1]+
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bits[j*8]
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;
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}
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num_blocks++;
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}
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bitidx = 0;
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block_done = 0;
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half_switch = 0;
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}
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if(i < GraphTraceLen)
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dir =(dest[i-1] > dest[i]) ? 0 : 1;
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}
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if(bitidx==255)
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bitidx=0;
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warnings = 0;
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if(num_blocks == 4) break;
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}
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memcpy(outBlocks, blocks, 16*num_blocks);
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return num_blocks;
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}
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bool IsBlock0PCF7931(uint8_t *block) {
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// assuming all RFU bits are set to 0
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// if PAC is enabled password is set to 0
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if (block[7] == 0x01)
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{
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if (!memcmp(block, "\x00\x00\x00\x00\x00\x00\x00", 7) && !memcmp(block+9, "\x00\x00\x00\x00\x00\x00\x00", 7))
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return true;
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}
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else if (block[7] == 0x00)
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{
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if (!memcmp(block+9, "\x00\x00\x00\x00\x00\x00\x00", 7))
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return true;
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}
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return false;
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}
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bool IsBlock1PCF7931(uint8_t *block) {
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// assuming all RFU bits are set to 0
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if (block[10] == 0 && block[11] == 0 && block[12] == 0 && block[13] == 0)
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if((block[14] & 0x7f) <= 9 && block[15] <= 9)
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return true;
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return false;
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}
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void ReadPCF7931() {
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int found_blocks = 0; // successfully read blocks
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int max_blocks = 8; // readable blocks
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uint8_t memory_blocks[8][17]; // PCF content
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uint8_t single_blocks[8][17]; // PFC blocks with unknown position
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int single_blocks_cnt = 0;
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size_t n = 0; // transmitted blocks
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uint8_t tmp_blocks[4][16]; // temporary read buffer
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uint8_t found_0_1 = 0; // flag: blocks 0 and 1 were found
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int errors = 0; // error counter
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int tries = 0; // tries counter
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memset(memory_blocks, 0, 8*17*sizeof(uint8_t));
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memset(single_blocks, 0, 8*17*sizeof(uint8_t));
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int i = 0, j = 0;
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do {
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i = 0;
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memset(tmp_blocks, 0, 4*16*sizeof(uint8_t));
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n = DemodPCF7931((uint8_t**)tmp_blocks);
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if(!n)
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++errors;
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// exit if no block is received
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if (errors >= 10 && found_blocks == 0 && single_blocks_cnt == 0) {
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Dbprintf("Error, no tag or bad tag");
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return;
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}
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// exit if too many errors during reading
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if (tries > 50 && (2*errors > tries)) {
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Dbprintf("Error reading the tag");
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Dbprintf("Here is the partial content");
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goto end;
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}
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// our logic breaks if we don't get at least two blocks
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if (n < 2) {
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if (n == 0 || !memcmp(tmp_blocks[0], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16))
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continue;
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if (single_blocks_cnt < max_blocks) {
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for (i = 0; i < single_blocks_cnt; ++i) {
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if (!memcmp(single_blocks[i], tmp_blocks[0], 16)) {
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j = 1;
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break;
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}
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}
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if (j != 1) {
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memcpy(single_blocks[single_blocks_cnt], tmp_blocks[0], 16);
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single_blocks_cnt++;
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}
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j = 0;
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}
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++tries;
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continue;
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}
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Dbprintf("(dbg) got %d blocks (%d/%d found) (%d tries, %d errors)", n, found_blocks, (max_blocks == 0 ? found_blocks : max_blocks), tries, errors);
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i = 0;
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if(!found_0_1) {
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while (i < n - 1) {
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if (IsBlock0PCF7931(tmp_blocks[i]) && IsBlock1PCF7931(tmp_blocks[i+1])) {
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found_0_1 = 1;
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memcpy(memory_blocks[0], tmp_blocks[i], 16);
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memcpy(memory_blocks[1], tmp_blocks[i+1], 16);
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memory_blocks[0][ALLOC] = memory_blocks[1][ALLOC] = 1;
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// block 1 tells how many blocks are going to be sent
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max_blocks = MAX((memory_blocks[1][14] & 0x7f), memory_blocks[1][15]) + 1;
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found_blocks = 2;
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Dbprintf("Found blocks 0 and 1. PCF is transmitting %d blocks.", max_blocks);
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// handle the following blocks
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for (j = i + 2; j < n; ++j) {
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memcpy(memory_blocks[found_blocks], tmp_blocks[j], 16);
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memory_blocks[found_blocks][ALLOC] = 1;
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++found_blocks;
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}
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break;
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}
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++i;
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}
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} else {
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// Trying to re-order blocks
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// Look for identical block in memory blocks
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while (i < n-1) {
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// skip all zeroes blocks
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if (memcmp(tmp_blocks[i], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16)) {
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for (j = 1; j < max_blocks - 1; ++j) {
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if (!memcmp(tmp_blocks[i], memory_blocks[j], 16) && !memory_blocks[j+1][ALLOC]) {
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memcpy(memory_blocks[j+1], tmp_blocks[i+1], 16);
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memory_blocks[j+1][ALLOC] = 1;
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if (++found_blocks >= max_blocks) goto end;
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}
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}
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}
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if (memcmp(tmp_blocks[i+1], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16)) {
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for (j = 0; j < max_blocks; ++j) {
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if (!memcmp(tmp_blocks[i+1], memory_blocks[j], 16) && !memory_blocks[(j == 0 ? max_blocks : j) -1][ALLOC]) {
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if (j == 0) {
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memcpy(memory_blocks[max_blocks - 1], tmp_blocks[i], 16);
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memory_blocks[max_blocks - 1][ALLOC] = 1;
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} else {
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memcpy(memory_blocks[j-1], tmp_blocks[i], 16);
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memory_blocks[j-1][ALLOC] = 1;
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}
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if (++found_blocks >= max_blocks) goto end;
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}
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}
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}
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++i;
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}
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}
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++tries;
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if (BUTTON_PRESS()) {
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Dbprintf("Button pressed, stopping.");
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goto end;
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}
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}
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while (found_blocks != max_blocks);
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end:
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Dbprintf("-----------------------------------------");
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Dbprintf("Memory content:");
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Dbprintf("-----------------------------------------");
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for (i = 0; i < max_blocks; ++i) {
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if (memory_blocks[i][ALLOC])
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print_result("Block", memory_blocks[i], 16);
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else
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Dbprintf("<missing block %d>", i);
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}
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Dbprintf("-----------------------------------------");
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if (found_blocks < max_blocks) {
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Dbprintf("-----------------------------------------");
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Dbprintf("Blocks with unknown position:");
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Dbprintf("-----------------------------------------");
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for (i = 0; i < single_blocks_cnt; ++i)
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print_result("Block", single_blocks[i], 16);
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Dbprintf("-----------------------------------------");
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}
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cmd_send(CMD_ACK,0,0,0,0,0);
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}
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static void RealWritePCF7931(uint8_t *pass, uint16_t init_delay, int32_t l, int32_t p, uint8_t address, uint8_t byte, uint8_t data) {
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uint32_t tab[1024] = {0}; // data times frame
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uint32_t u = 0;
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uint8_t parity = 0;
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bool comp = 0;
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//BUILD OF THE DATA FRAME
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//alimentation of the tag (time for initializing)
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AddPatternPCF7931(init_delay, 0, 8192/2*T0_PCF, tab);
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AddPatternPCF7931(8192/2*T0_PCF + 319*T0_PCF+70, 3*T0_PCF, 29*T0_PCF, tab);
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//password indication bit
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AddBitPCF7931(1, tab, l, p);
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//password (on 56 bits)
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AddBytePCF7931(pass[0], tab, l, p);
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AddBytePCF7931(pass[1], tab, l, p);
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AddBytePCF7931(pass[2], tab, l, p);
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AddBytePCF7931(pass[3], tab, l, p);
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AddBytePCF7931(pass[4], tab, l, p);
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AddBytePCF7931(pass[5], tab, l, p);
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AddBytePCF7931(pass[6], tab, l, p);
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//programming mode (0 or 1)
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AddBitPCF7931(0, tab, l, p);
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//block adress on 6 bits
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for (u = 0; u < 6; ++u) {
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if (address&(1<<u)) { // bit 1
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++parity;
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AddBitPCF7931(1, tab, l, p);
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} else{ // bit 0
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AddBitPCF7931(0, tab, l, p);
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}
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}
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//byte address on 4 bits
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for (u = 0; u < 4; ++u)
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{
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if (byte&(1<<u)) { // bit 1
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parity++;
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AddBitPCF7931(1, tab, l, p);
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}
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else // bit 0
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AddBitPCF7931(0, tab, l, p);
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}
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//data on 8 bits
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for (u=0; u<8; u++)
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{
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if (data&(1<<u)) { // bit 1
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parity++;
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AddBitPCF7931(1, tab, l, p);
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}
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else //bit 0
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AddBitPCF7931(0, tab, l, p);
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}
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//parity bit
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if ((parity % 2) == 0)
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AddBitPCF7931(0, tab, l, p); //even parity
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else
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AddBitPCF7931(1, tab, l, p);//odd parity
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//time access memory
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AddPatternPCF7931(5120+2680, 0, 0, tab);
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//conversion of the scale time
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for (u = 0; u < 500; ++u)
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tab[u]=(tab[u] * 3)/2;
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//compensation of the counter reload
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while (!comp){
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comp = 1;
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for (u = 0; tab[u] != 0; ++u)
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if(tab[u] > 0xFFFF){
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tab[u] -= 0xFFFF;
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comp = 0;
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}
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}
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SendCmdPCF7931(tab);
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}
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/* Write on a byte of a PCF7931 tag
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* @param address : address of the block to write
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@param byte : address of the byte to write
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@param data : data to write
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*/
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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) {
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Dbprintf("Initialization delay : %d us", init_delay);
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Dbprintf("Offsets : %d us on the low pulses width, %d us on the low pulses positions", l, p);
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Dbprintf("Password (LSB first on each byte): %02x %02x %02x %02x %02x %02x %02x", pass1, pass2, pass3, pass4, pass5, pass6, pass7);
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Dbprintf("Block address : %02x", address);
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Dbprintf("Byte address : %02x", byte);
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Dbprintf("Data : %02x", data);
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uint8_t password[7] = {pass1, pass2, pass3, pass4, pass5, pass6, pass7};
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RealWritePCF7931 (password, init_delay, l, p, address, byte, data);
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}
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/* Send a trame to a PCF7931 tags
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* @param tab : array of the data frame
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*/
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void SendCmdPCF7931(uint32_t * tab){
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uint16_t u=0, tempo=0;
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Dbprintf("Sending data frame...");
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FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
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FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
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FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU );
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LED_A_ON();
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// steal this pin from the SSP and use it to control the modulation
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AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
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AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
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//initialization of the timer
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AT91C_BASE_PMC->PMC_PCER |= (0x1 << AT91C_ID_TC0);
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AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
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AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
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AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK; //clock at 48/32 MHz
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AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN;
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AT91C_BASE_TCB->TCB_BCR = 1;
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tempo = AT91C_BASE_TC0->TC_CV;
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for( u = 0; tab[u] != 0; u += 3){
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// modulate antenna
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HIGH(GPIO_SSC_DOUT);
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while (tempo != tab[u])
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tempo = AT91C_BASE_TC0->TC_CV;
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// stop modulating antenna
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LOW(GPIO_SSC_DOUT);
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while (tempo != tab[u+1])
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tempo = AT91C_BASE_TC0->TC_CV;
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// modulate antenna
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HIGH(GPIO_SSC_DOUT);
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while (tempo != tab[u+2])
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tempo = AT91C_BASE_TC0->TC_CV;
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}
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LED_A_OFF();
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FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
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SpinDelay(200);
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AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
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LED(0xFFFF, 1000);
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}
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/* Add a byte for building the data frame of PCF7931 tags
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* @param b : byte to add
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* @param tab : array of the data frame
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* @param l : offset on low pulse width
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* @param p : offset on low pulse positioning
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*/
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bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p){
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uint32_t u;
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for (u = 0; u < 8; ++u) {
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if (byte & (1 << u)) { //bit is 1
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if( AddBitPCF7931(1, tab, l, p)==1) return 1;
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} else { //bit is 0
|
|
if (AddBitPCF7931(0, tab, l, p)==1) return 1;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Add a bits for building the data frame of PCF7931 tags
|
|
* @param b : bit to add
|
|
* @param tab : array of the data frame
|
|
* @param l : offset on low pulse width
|
|
* @param p : offset on low pulse positioning
|
|
*/
|
|
bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p){
|
|
uint8_t u = 0;
|
|
|
|
//we put the cursor at the last value of the array
|
|
for ( u = 0; tab[u] != 0; u += 3 ) { }
|
|
|
|
if ( b == 1 ) { //add a bit 1
|
|
if ( u == 0 )
|
|
tab[u] = 34 * T0_PCF + p;
|
|
else
|
|
tab[u] = 34 * T0_PCF + tab[u-1] + p;
|
|
|
|
tab[u+1] = 6 * T0_PCF + tab[u] + l;
|
|
tab[u+2] = 88 * T0_PCF + tab[u+1] - l - p;
|
|
return 0;
|
|
} else { //add a bit 0
|
|
|
|
if ( u == 0 )
|
|
tab[u] = 98 * T0_PCF + p;
|
|
else
|
|
tab[u] = 98 * T0_PCF + tab[u-1] + p;
|
|
|
|
tab[u+1] = 6 * T0_PCF + tab[u] + l;
|
|
tab[u+2] = 24 * T0_PCF + tab[u+1] - l - p;
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/* Add a custom pattern in the data frame
|
|
* @param a : delay of the first high pulse
|
|
* @param b : delay of the low pulse
|
|
* @param c : delay of the last high pulse
|
|
* @param tab : array of the data frame
|
|
*/
|
|
bool AddPatternPCF7931(uint32_t a, uint32_t b, uint32_t c, uint32_t * tab){
|
|
uint32_t u = 0;
|
|
for(u = 0; tab[u] != 0; u += 3){} //we put the cursor at the last value of the array
|
|
|
|
tab[u] = (u == 0) ? a : a + tab[u-1];
|
|
tab[u+1] = b + tab[u];
|
|
tab[u+2] = c + tab[u+1];
|
|
|
|
return 0;
|
|
} |