X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/c728b2b4cf2ce9fe4eebf0e46d74ef8542e56c16..d115f9a4542b2d24a7e8c7741dafaced0a64c9da:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index 862d05ba..8bbe5beb 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -81,10 +81,9 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p j--; // overwrite parity with next data // if parity fails then return 0 switch (pType) { - case 3: if (BitStream[j]==1) return 0; break; //should be 0 spacer bit - case 2: if (BitStream[j]==0) return 0; break; //should be 1 spacer bit - default: //test parity - if (parityTest(parityWd, pLen, pType) == 0) return 0; break; + case 3: if (BitStream[j]==1) { return 0; } break; //should be 0 spacer bit + case 2: if (BitStream[j]==0) { return 0; } break; //should be 1 spacer bit + default: if (parityTest(parityWd, pLen, pType) == 0) { return 0; } break; //test parity } bitCnt+=(pLen-1); parityWd = 0; @@ -148,8 +147,11 @@ uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits) //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; - for (int idx=0; idx < *size - pLen; idx++){ + // Sanity check. If preamble length is bigger than bitstream length. + if ( *size <= pLen ) return 0; + + uint8_t foundCnt = 0; + for (int idx = 0; idx < *size - pLen; idx++){ if (memcmp(BitStream+idx, preamble, pLen) == 0){ //first index found foundCnt++; @@ -167,13 +169,13 @@ 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 -uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo) +int 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) return 0; //allow only 1s and 0s + if (BitStream[1]>1) return -1; //allow only 1s and 0s // 111111111 bit pattern represent start of frame // include 0 in front to help get start pos @@ -184,14 +186,15 @@ uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_ uint8_t FmtLen = 10; *startIdx = 0; errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx); - if (errChk == 0 || *size < 64) return 0; + if (errChk == 0 ) return -4; + if (*size < 64) return -3; if (*size > 64) FmtLen = 22; *startIdx += 1; //get rid of 0 from preamble idx = *startIdx + 9; for (i=0; i> 63); @@ -259,13 +262,15 @@ int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int //by marshmellow void askAmp(uint8_t *BitStream, size_t size) { - for(size_t i = 1; i=30) //large jump up - BitStream[i]=127; - else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down - BitStream[i]=-127; + uint8_t last = 128; + for(size_t i = 1; i < size; ++i){ + if (BitStream[i]-BitStream[i-1] >= 30) //large jump up + last = 255; + else if(BitStream[i-1] - BitStream[i] >= 20) //large jump down + last = 0; + + BitStream[i] = last; } - return; } //by marshmellow @@ -463,10 +468,10 @@ int gProxII_Demod(uint8_t BitStream[], size_t *size) //return start position return (int) startIdx; } - return -5; + return -5; //spacer bits not found - not a valid gproxII } -//translate wave to 11111100000 (1 for each short wave 0 for each long wave) +//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) { size_t last_transition = 0; @@ -490,6 +495,7 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8) // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10 + // (could also be fc/5 && fc/7 for fsk1 = 4-9) for(idx = 161; idx < size-20; idx++) { // threshold current value @@ -497,23 +503,24 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow else dest[idx] = 1; // Check for 0->1 transition - if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition + if (dest[idx-1] < dest[idx]) { preLastSample = LastSample; LastSample = currSample; currSample = idx-last_transition; if (currSample < (fclow-2)){ //0-5 = garbage noise (or 0-3) //do nothing with extra garbage - } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves or 3-6 = 5 + } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves (or 3-6 = 5) + //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5) if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample == 0 )){ - dest[numBits-1]=1; //correct previous 9 wave surrounded by 8 waves + dest[numBits-1]=1; } dest[numBits++]=1; - } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = garbage + } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = unusable garbage //do nothing with beginning garbage - } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's + } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's (or 4 then a 6 should be two 5's) dest[numBits++]=1; - } else { //9+ = 10 sample waves + } else { //9+ = 10 sample waves (or 6+ = 7) dest[numBits++]=0; } last_transition = idx; @@ -523,6 +530,7 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow } //translate 11111100000 to 10 +//rfLen = clock, fchigh = larger field clock, fclow = smaller field clock size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow) { @@ -534,6 +542,7 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, n++; if (dest[idx]==lastval) continue; + //find out how many bits (n) we collected //if lastval was 1, we have a 1->0 crossing if (dest[idx-1]==1) { n = (n * fclow + rfLen/2) / rfLen; @@ -542,6 +551,7 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, } if (n == 0) n = 1; + //add to our destination the bits we collected memset(dest+numBits, dest[idx-1]^invert , n); numBits += n; n=0; @@ -575,7 +585,7 @@ int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32 { if (justNoise(dest, *size)) return -1; - size_t numStart=0, size2=*size, startIdx=0; + size_t numStart=0, size2 = *size, startIdx=0; // FSK demodulator *size = fskdemod(dest, size2,50,1,10,8); //fsk2a if (*size < 96*2) return -2; @@ -607,7 +617,7 @@ int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, ui { if (justNoise(dest, *size)) return -1; - size_t numStart=0, size2=*size, startIdx=0; + size_t numStart=0, size2 = *size, startIdx=0; // FSK demodulator *size = fskdemod(dest, size2,50,1,10,8); //fsk2a if (*size < 96) return -2; @@ -674,10 +684,15 @@ int VikingDemod_AM(uint8_t *dest, size_t *size) { uint8_t preamble[] = {1,1,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); if (errChk == 0) return -4; //preamble not found - uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8) - ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8) - ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8); - if ( checkCalc != 0xA8 ) return -5; + uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ + bytebits_to_byte(dest+startIdx+8,8) ^ + bytebits_to_byte(dest+startIdx+16,8) ^ + bytebits_to_byte(dest+startIdx+24,8) ^ + bytebits_to_byte(dest+startIdx+32,8) ^ + bytebits_to_byte(dest+startIdx+40,8) ^ + bytebits_to_byte(dest+startIdx+48,8) ^ + bytebits_to_byte(dest+startIdx+56,8); + if ( checkCalc != 0xA8 ) return -5; if (*size != 64) return -6; //return start position return (int) startIdx; @@ -696,7 +711,6 @@ int PrescoDemod(uint8_t *dest, size_t *size) { return (int) startIdx; } - // Ask/Biphase Demod then try to locate an ISO 11784/85 ID // BitStream must contain previously askrawdemod and biphasedemoded data int FDXBdemodBI(uint8_t *dest, size_t *size) @@ -712,6 +726,39 @@ int FDXBdemodBI(uint8_t *dest, size_t *size) return (int)startIdx; } +// ASK/Diphase fc/64 (inverted Biphase) +// Note: this i s not a demod, this is only a detection +// the parameter *dest needs to be demoded before call +int JablotronDemod(uint8_t *dest, size_t *size){ + //make sure buffer has enough data + if (*size < 64) return -1; + + size_t startIdx = 0; + // 0xFFFF preamble, 64bits + uint8_t preamble[] = { + 1,1,1,1, + 1,1,1,1, + 1,1,1,1, + 1,1,1,1, + 0 + }; + + uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); + if (errChk == 0) return -4; //preamble not found + if (*size != 64) return -3; + + uint8_t checkchksum = 0; + for (int i=16; i < 56; i += 8) { + checkchksum += bytebits_to_byte(dest+startIdx+i,8); + } + checkchksum ^= 0x3A; + + uint8_t crc = bytebits_to_byte(dest+startIdx+56, 8); + + if ( checkchksum != crc ) return -5; + return (int)startIdx; +} + // by marshmellow // FSK Demod then try to locate an AWID ID int AWIDdemodFSK(uint8_t *dest, size_t *size) @@ -755,6 +802,19 @@ int PyramiddemodFSK(uint8_t *dest, size_t *size) return (int)startIdx; } +// find nedap preamble in already demoded data +int NedapDemod(uint8_t *dest, size_t *size) { + //make sure buffer has data + if (*size < 128) return -3; + + size_t startIdx = 0; + //uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0,0,0,1}; + uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0}; + uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); + if (errChk == 0) return -4; //preamble not found + return (int) startIdx; +} + // by marshmellow // to detect a wave that has heavily clipped (clean) samples uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low) @@ -1495,8 +1555,8 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) numBits += (firstFullWave / *clock); //set start of wave as clock align lastClkBit = firstFullWave; - //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen); - //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit); + if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u",firstFullWave,fullWaveLen); + if (g_debugMode==2) prnt("DEBUG: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc); waveStart = 0; dest[numBits++] = curPhase; //set first read bit for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){ @@ -1679,7 +1739,7 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { i=0; // warning - overwriting buffer given with raw wave data with ST removed... while ( dataloc < bufsize-(clk/2) ) { - //compensate for long high at end of ST not being high... (we cut out the high part) + //compensate for long high at end of ST not being high due to signal loss... (and we cut out the start of wave high part) if (buffer[dataloc]low && buffer[dataloc+3]low) { for(i=0; i < clk/2-tol; ++i) { buffer[dataloc+i] = high+5; @@ -1694,7 +1754,7 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { } } newloc += i; - //skip next ST + //skip next ST - we just assume it will be there from now on... dataloc += clk*4; } *size = newloc;