github/RRG-Proxmark3
1
0
Fork 0
mirror of https://github.com/RfidResearchGroup/proxmark3.git synced 2025-08-14 18:48:13 -07:00
Code Issues Projects Releases Packages Wiki Activity Actions

just in case psk get odd clocks in some old system

Browse source
This commit is contained in:
iceman1001 2023-07-22 23:27:30 +02:00
commit 8e38723149
1 changed files with 9 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

16
common/lfdemod.c
View file

@ -1118,10 +1118,12 @@ uint16_t countFC(const uint8_t *bits, size_t size, bool fskAdj) {
fcH = fcLens[best2];
fcL = fcLens[best1];
}
/*
if ((size - 180) / fcH / 3 > fcCnts[best1] + fcCnts[best2]) {
if (g_debugMode == 2) prnt("DEBUG countfc: fc is too large: %zu > %u. Not psk or fsk", (size - 180) / fcH / 3, fcCnts[best1] + fcCnts[best2]);
return 0; //lots of waves not psk or fsk
}
*/
// TODO: take top 3 answers and compare to known Field clocks to get top 2
uint16_t fcs = (((uint16_t)fcH) << 8) | fcL;
@ -1132,8 +1134,8 @@ uint16_t countFC(const uint8_t *bits, size_t size, bool fskAdj) {
// detect psk clock by reading each phase shift
// a phase shift is determined by measuring the sample length of each wave
int DetectPSKClock(uint8_t *dest, size_t size, int clock, size_t *firstPhaseShift, uint8_t *curPhase, uint8_t *fc) {
uint8_t clk[] = {255, 16, 32, 40, 50, 64, 100, 128, 255}; //255 is not a valid clock
uint16_t loopCnt = 4096; //don't need to loop through entire array...
uint16_t clk[] = {255, 16, 32, 40, 50, 64, 100, 128, 256, 272, 384}; // 255 is not a valid clock
uint16_t loopCnt = 4096; // don't need to loop through entire array...
if (size < 160 + 20) return 0;
// size must be larger than 20 here, and 160 later on.
@ -1154,8 +1156,8 @@ int DetectPSKClock(uint8_t *dest, size_t size, int clock, size_t *firstPhaseShif
uint8_t clkCnt;
uint16_t waveLenCnt, fullWaveLen = 0;
uint16_t bestErr[] = {1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000};
uint16_t peaksdet[] = {0, 0, 0, 0, 0, 0, 0, 0, 0};
uint16_t bestErr[] = {1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000, 1000};
uint16_t peaksdet[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
//find start of modulating data in trace
size_t i = findModStart(dest, size, *fc);
@ -1177,7 +1179,7 @@ int DetectPSKClock(uint8_t *dest, size_t size, int clock, size_t *firstPhaseShif
}
//test each valid clock from greatest to smallest to see which lines up
for (clkCnt = 7; clkCnt >= 1 ; clkCnt--) {
for (clkCnt = 9; clkCnt >= 1 ; clkCnt--) {
uint8_t tol = *fc / 2;
size_t lastClkBit = firstFullWave; //set end of wave as clock align
size_t waveStart = 0;
@ -1217,8 +1219,8 @@ int DetectPSKClock(uint8_t *dest, size_t size, int clock, size_t *firstPhaseShif
}
//all tested with errors
//return the highest clk with the most peaks found
uint8_t best = 7;
for (i = 7; i >= 1; i--) {
uint8_t best = 9;
for (i = 9; i >= 1; i--) {
if (peaksdet[i] > peaksdet[best])
best = i;