X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/0d2c590974319db6fc54400ce153d86b68a09852..fd3be901ea022a368eddd3e08126f4d06f17d64a:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index edebe456..f27ffff3 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -68,7 +68,7 @@ uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType) //by marshmellow // takes a array of binary values, start position, length of bits per parity (includes parity bit), -// Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run) +// Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run) size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen) { uint32_t parityWd = 0; @@ -80,10 +80,11 @@ 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 - if (pType == 2) { // then marker bit which should be a 1 - if (!BitStream[j]) return 0; - } else { - if (parityTest(parityWd, pLen, pType) == 0) 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; } bitCnt+=(pLen-1); parityWd = 0; @@ -96,6 +97,7 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p // by marshmellow // takes a array of binary values, length of bits per parity (includes parity bit), // Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run) +// Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType) { uint32_t parityWd = 0; @@ -114,7 +116,6 @@ size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t p dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1; break; } - bitCnt += pLen; parityWd = 0; } @@ -260,9 +261,9 @@ void askAmp(uint8_t *BitStream, size_t size) { for(size_t i = 1; i=30) //large jump up - BitStream[i]=127; + BitStream[i]=255; else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down - BitStream[i]=-127; + BitStream[i]=0; } return; } @@ -462,10 +463,10 @@ 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; @@ -489,6 +490,7 @@ 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 @@ -496,23 +498,24 @@ 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; @@ -522,6 +525,7 @@ 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) { @@ -533,6 +537,7 @@ 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; @@ -541,6 +546,7 @@ 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; @@ -673,10 +679,15 @@ 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; @@ -695,7 +706,6 @@ 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) @@ -1494,8 +1504,8 @@ 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++){ @@ -1678,7 +1688,7 @@ 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; @@ -1693,7 +1703,7 @@ 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;