X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/39676885b4bbfcc6ab491ad988e0f64ba5898165..2147c307785639944f4843d7cf0d245778532ecf:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index 144cb327..46ac4924 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -55,7 +55,7 @@ uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) } //by marshmellow -//search for given preamble in given BitStream and return startIndex and length +//search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx) { uint8_t foundCnt=0; @@ -78,7 +78,7 @@ uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_ //by marshmellow //takes 1s and 0s and searches for EM410x format - output EM ID -uint64_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx) +uint64_t Em410xDecodeOld(uint8_t *BitStream, size_t *size, size_t *startIdx) { //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future // otherwise could be a void with no arguments @@ -120,6 +120,52 @@ uint64_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx) return 0; } +//by marshmellow +//takes 1s and 0s and searches for EM410x format - output EM ID +uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo) +{ + //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future + // otherwise could be a void with no arguments + //set defaults + uint32_t i = 0; + if (BitStream[1]>1){ //allow only 1s and 0s + // PrintAndLog("no data found"); + return 0; + } + // 111111111 bit pattern represent start of frame + uint8_t preamble[] = {1,1,1,1,1,1,1,1,1}; + uint32_t idx = 0; + uint32_t parityBits = 0; + uint8_t errChk = 0; + uint8_t FmtLen = 10; + *startIdx = 0; + for (uint8_t extraBitChk=0; extraBitChk<5; extraBitChk++){ + errChk = preambleSearch(BitStream+extraBitChk+*startIdx, preamble, sizeof(preamble), size, startIdx); + if (errChk == 0) return 0; + if (*size>64) FmtLen = 22; + idx = *startIdx + 9; + for (i=0; i> 63); + *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]); + } + } + if (errChk != 0) return 1; + //skip last 5 bit parity test for simplicity. + // *size = 64 | 128; + } + return 0; +} + //by marshmellow //takes 3 arguments - clock, invert, maxErr as integers //attempts to demodulate ask while decoding manchester @@ -151,6 +197,8 @@ int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int max int iii = 0; uint32_t gLen = *size; if (gLen > 3000) gLen=3000; + //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance + if (!maxErr) gLen=*clk*2; uint8_t errCnt =0; uint16_t MaxBits = 500; uint32_t bestStart = *size; @@ -305,16 +353,29 @@ int manrawdecode(uint8_t * BitStream, size_t *size) } //by marshmellow -//take 01 or 10 = 0 and 11 or 00 = 1 +//take 01 or 10 = 1 and 11 or 00 = 0 +//check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010 int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) { uint16_t bitnum=0; uint32_t errCnt =0; - uint32_t i; - uint16_t MaxBits=500; - i=offset; - if (size == 0) return -1; - for (;i<*size-2; i+=2){ + size_t i=offset; + uint16_t MaxBits=512; + //if not enough samples - error + if (*size < 51) return -1; + //check for phase change faults - skip one sample if faulty + uint8_t offsetA = 1, offsetB = 1; + for (; i<48; i+=2){ + if (BitStream[i+1]==BitStream[i+2]) offsetA=0; + if (BitStream[i+2]==BitStream[i+3]) offsetB=0; + } + if (!offsetA && offsetB) offset++; + for (i=offset; i<*size-3; i+=2){ + //check for phase error + if (i<*size-3 && BitStream[i+1]==BitStream[i+2]) { + BitStream[bitnum++]=77; + errCnt++; + } if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){ BitStream[bitnum++]=1^invert; } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){ @@ -381,6 +442,8 @@ int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int max uint32_t iii = 0; uint32_t gLen = *size; if (gLen > 500) gLen=500; + //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance + if (!maxErr) gLen=*clk*2; uint8_t errCnt =0; uint32_t bestStart = *size; uint32_t bestErrCnt = maxErr; //(*size/1000); @@ -1079,7 +1142,9 @@ void psk1TOpsk2(uint8_t *BitStream, size_t size) size_t i=1; uint8_t lastBit=BitStream[0]; for (; i= dest[i+2]){ - if (waveStart == 0) { - waveStart = i+1; - avgWaveVal=dest[i+1]; - //PrintAndLog("DEBUG: waveStart: %d",waveStart); - } else { - waveEnd = i+1; - //PrintAndLog("DEBUG: waveEnd: %d",waveEnd); - waveLenCnt = waveEnd-waveStart; - lastAvgWaveVal = avgWaveVal/waveLenCnt; - if (waveLenCnt > fc){ - firstFullWave = waveStart; - fullWaveLen=waveLenCnt; - //if average wave value is > graph 0 then it is an up wave or a 1 - if (lastAvgWaveVal > 128) curPhase^=1; - break; - } - waveStart=0; - avgWaveVal=0; - } + waveEnd = i+1; + //PrintAndLog("DEBUG: waveEnd: %d",waveEnd); + waveLenCnt = waveEnd-waveStart; + if (waveLenCnt > fc && waveStart > fc){ //not first peak and is a large wave + lastAvgWaveVal = avgWaveVal/(waveLenCnt); + firstFullWave = waveStart; + fullWaveLen=waveLenCnt; + //if average wave value is > graph 0 then it is an up wave or a 1 + if (lastAvgWaveVal > 123) curPhase^=1; //fudge graph 0 a little 123 vs 128 + break; + } + waveStart = i+1; + avgWaveVal = 0; } - avgWaveVal+=dest[i+1]; + avgWaveVal+=dest[i+2]; } //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen); lastClkBit = firstFullWave; //set start of wave as clock align + //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit); waveStart = 0; errCnt=0; size_t numBits=0; - //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit); - + //set skipped bits + memset(dest+numBits,curPhase^1,firstFullWave / *clock); + numBits += (firstFullWave / *clock); + dest[numBits++] = curPhase; //set first read bit for (i = firstFullWave+fullWaveLen-1; i < *size-3; i++){ //top edge of wave = start of new wave if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){ @@ -1643,26 +1703,23 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) waveEnd = i+1; waveLenCnt = waveEnd-waveStart; lastAvgWaveVal = avgWaveVal/waveLenCnt; - if (waveLenCnt > fc){ + if (waveLenCnt > fc){ //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal); //if 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 curPhase^=1; - dest[numBits] = curPhase; - numBits++; + dest[numBits++] = curPhase; lastClkBit += *clock; - } else if (i lastClkBit + *clock + tol + fc){ lastClkBit += *clock; //no phase shift but clock bit - dest[numBits] = curPhase; - numBits++; + dest[numBits++] = curPhase; } avgWaveVal=0; waveStart=i+1;