X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/56de46b4667c468fa751747b6d1346b5be6f5bd3..199c74a47f3d44b815650d7ce79023cdc75ca550:/common/lfdemod.c?ds=inline diff --git a/common/lfdemod.c b/common/lfdemod.c index 74e3e6b6..eb84203e 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -40,6 +40,8 @@ //---------------------------------Utilities Section-------------------------------------------- //********************************************************************************************** #define LOWEST_DEFAULT_CLOCK 32 +#define FSK_PSK_THRESHOLD 123 + //to allow debug print calls when used not on device void dummy(char *fmt, ...){} #ifndef ON_DEVICE @@ -53,11 +55,10 @@ void dummy(char *fmt, ...){} #endif uint8_t justNoise(uint8_t *BitStream, size_t size) { - static const uint8_t THRESHOLD = 123; //test samples are not just noise uint8_t justNoise1 = 1; for(size_t idx=0; idx < size && justNoise1 ;idx++){ - justNoise1 = BitStream[idx] < THRESHOLD; + justNoise1 = BitStream[idx] < FSK_PSK_THRESHOLD; } return justNoise1; } @@ -72,7 +73,7 @@ int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi if (BitStream[i] > *high) *high = BitStream[i]; if (BitStream[i] < *low) *low = BitStream[i]; } - if (*high < 123) return -1; // just noise + if (*high < FSK_PSK_THRESHOLD) return -1; // just noise *high = ((*high-128)*fuzzHi + 12800)/100; *low = ((*low-128)*fuzzLo + 12800)/100; return 1; @@ -197,18 +198,18 @@ uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_ } // find start of modulating data (for fsk and psk) in case of beginning noise or slow chip startup. -size_t findModStart(uint8_t dest[], size_t size, uint8_t threshold_value, uint8_t expWaveSize) { +size_t findModStart(uint8_t dest[], size_t size, uint8_t expWaveSize) { size_t i = 0; size_t waveSizeCnt = 0; uint8_t thresholdCnt = 0; - bool isAboveThreshold = dest[i++] >= threshold_value; + bool isAboveThreshold = dest[i++] >= FSK_PSK_THRESHOLD; for (; i < size-20; i++ ) { - if(dest[i] < threshold_value && isAboveThreshold) { + if(dest[i] < FSK_PSK_THRESHOLD && isAboveThreshold) { thresholdCnt++; if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break; isAboveThreshold = false; waveSizeCnt = 0; - } else if (dest[i] >= threshold_value && !isAboveThreshold) { + } else if (dest[i] >= FSK_PSK_THRESHOLD && !isAboveThreshold) { thresholdCnt++; if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break; isAboveThreshold = true; @@ -307,15 +308,17 @@ uint32_t manchesterEncode2Bytes(uint16_t datain) { //by marshmellow //encode binary data into binary manchester -//NOTE: BitStream must have double the size available in memory to do the swap +//NOTE: BitStream must have triple the size of "size" available in memory to do the swap int ManchesterEncode(uint8_t *BitStream, size_t size) { - size_t modIdx=size, i=0; - if (size>modIdx) return -1; + //allow up to 4K out (means BitStream must be at least 2048+4096 to handle the swap) + size = (size>2048) ? 2048 : size; + size_t modIdx = size; + size_t i; for (size_t idx=0; idx < size; idx++){ BitStream[idx+modIdx++] = BitStream[idx]; BitStream[idx+modIdx++] = BitStream[idx]^1; } - for (; i<(size*2); i++){ + for (i=0; i<(size*2); i++){ BitStream[i] = BitStream[i+size]; } return i; @@ -509,7 +512,7 @@ int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){ //by marshmellow //detect nrz clock by reading #peaks vs no peaks(or errors) -int DetectNRZClock_ext(uint8_t dest[], size_t size, int clock, size_t *clockStartIdx) { +int DetectNRZClock(uint8_t dest[], size_t size, int clock, size_t *clockStartIdx) { size_t i=0; uint8_t clk[]={8,16,32,40,50,64,100,128,255}; size_t loopCnt = 4096; //don't need to loop through entire array... @@ -625,11 +628,6 @@ int DetectNRZClock_ext(uint8_t dest[], size_t size, int clock, size_t *clockStar return clk[best]; } -int DetectNRZClock(uint8_t dest[], size_t size, int clock) { - size_t bestStart=0; - return DetectNRZClock_ext(dest, size, clock, &bestStart); -} - //by marshmellow //countFC is to detect the field clock lengths. //counts and returns the 2 most common wave lengths @@ -1334,9 +1332,10 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr // by marshmellow - demodulate NRZ wave - requires a read with strong signal // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak -int nrzRawDemod_ext(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx) { +int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx) { if (justNoise(dest, *size)) return -1; - *clk = DetectNRZClock(dest, *size, *clk); + size_t clkStartIdx = 0; + *clk = DetectNRZClock(dest, *size, *clk, &clkStartIdx); if (*clk==0) return -2; size_t i, gLen = 4096; if (gLen>*size) gLen = *size-20; @@ -1368,10 +1367,6 @@ int nrzRawDemod_ext(uint8_t *dest, size_t *size, int *clk, int *invert, int *sta *size = numBits; return 0; } -int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert) { - int startIdx = 0; - return nrzRawDemod_ext(dest, size, clk, invert, &startIdx); -} //translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq]) size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow, int *startIdx) { @@ -1380,16 +1375,15 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow if (fchigh==0) fchigh=10; if (fclow==0) fclow=8; //set the threshold close to 0 (graph) or 128 std to avoid static - uint8_t threshold_value = 123; size_t preLastSample = 0; size_t LastSample = 0; size_t currSample = 0; if ( size < 1024 ) return 0; // not enough samples //find start of modulating data in trace - idx = findModStart(dest, size, threshold_value, fchigh); + idx = findModStart(dest, size, fchigh); // Need to threshold first sample - if(dest[idx] < threshold_value) dest[0] = 0; + if(dest[idx] < FSK_PSK_THRESHOLD) dest[0] = 0; else dest[0] = 1; last_transition = idx; @@ -1401,7 +1395,7 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow // (could also be fc/5 && fc/7 for fsk1 = 4-9) for(; idx < size; idx++) { // threshold current value - if (dest[idx] < threshold_value) dest[idx] = 0; + if (dest[idx] < FSK_PSK_THRESHOLD) dest[idx] = 0; else dest[idx] = 1; // Check for 0->1 transition @@ -1531,54 +1525,55 @@ void psk2TOpsk1(uint8_t *BitStream, size_t size) { return; } +size_t pskFindFirstPhaseShift(uint8_t samples[], size_t size, uint8_t *curPhase, size_t waveStart, uint16_t fc, uint16_t *fullWaveLen) { + uint16_t loopCnt = (size+3 < 4096) ? size : 4096; //don't need to loop through entire array... + + uint16_t avgWaveVal=0, lastAvgWaveVal=0; + size_t i = waveStart, waveEnd, waveLenCnt, firstFullWave; + for (; i= samples[i+2]){ + waveEnd = i+1; + if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u", waveEnd, waveStart); + waveLenCnt = waveEnd-waveStart; + if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+8)){ //not first peak and is a large wave but not out of whack + lastAvgWaveVal = avgWaveVal/(waveLenCnt); + firstFullWave = waveStart; + *fullWaveLen = waveLenCnt; + //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting) + if (lastAvgWaveVal > FSK_PSK_THRESHOLD) *curPhase ^= 1; + return firstFullWave; + } + waveStart = i+1; + avgWaveVal = 0; + } + avgWaveVal += samples[i+2]; + } + return 0; +} + //by marshmellow - demodulate PSK1 wave //uses wave lengths (# Samples) int pskRawDemod_ext(uint8_t dest[], size_t *size, int *clock, int *invert, int *startIdx) { - if (size == 0) return -1; - uint16_t loopCnt = 4096; //don't need to loop through entire array... - if (*size> 8; - if (fc2 == 10) return -1; //fsk found - quit + if ((fc >> 8) == 10) return -1; //fsk found - quit fc = fc & 0xFF; if (fc!=2 && fc!=4 && fc!=8) return -1; - //PrintAndLog("DEBUG: FC: %d",fc); *clock = DetectPSKClock(dest, *size, *clock); if (*clock == 0) return -1; //find start of modulating data in trace - uint8_t threshold_value = 123; //-5 - i = findModStart(dest, *size, threshold_value, fc); + i = findModStart(dest, *size, fc); //find first phase shift - int avgWaveVal=0, lastAvgWaveVal=0; - waveStart = i; - for (; i= dest[i+2]){ - waveEnd = i+1; - if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u",waveEnd, waveStart); - waveLenCnt = waveEnd-waveStart; - if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+3)){ //not first peak and is a large wave but not out of whack - lastAvgWaveVal = avgWaveVal/(waveLenCnt); - firstFullWave = waveStart; - fullWaveLen=waveLenCnt; - //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting) - if (lastAvgWaveVal > threshold_value) curPhase ^= 1; - break; - } - - waveStart = i+1; - avgWaveVal = 0; - } - avgWaveVal += dest[i+2]; - } + firstFullWave = pskFindFirstPhaseShift(dest, *size, &curPhase, i, fc, &fullWaveLen); if (firstFullWave == 0) { // no phase shift detected - could be all 1's or 0's - doesn't matter where we start // so skip a little to ensure we are past any Start Signal @@ -1606,9 +1601,7 @@ int pskRawDemod_ext(uint8_t dest[], size_t *size, int *clock, int *invert, int * } else { //waveEnd waveEnd = i+1; waveLenCnt = waveEnd-waveStart; - lastAvgWaveVal = avgWaveVal/waveLenCnt; if (waveLenCnt > fc){ - //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal); //this wave is a phase shift //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc); if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit @@ -1710,6 +1703,8 @@ int FDXBdemodBI(uint8_t *dest, size_t *size) { uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); if (errChk == 0) return -2; //preamble not found + if (*size != 128) return -3; //wrong size for fdxb + //return start position return (int)startIdx; }