X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/d1869c3336e82b7f2eb68b7fa9a5bdb865ff6b23..cf194819cc71d7e0121e896e71989efc6dbfc280:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index 5ed2d16c..cf11b25b 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; @@ -95,7 +96,8 @@ 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), and binary Length (length to run) +// 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; @@ -106,10 +108,12 @@ size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t p dest[j++] = (BitSource[word+bit]); } // if parity fails then return 0 - if (pType == 2) { // then marker bit which should be a 1 - dest[j++]=1; - } else { - dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1; + switch (pType) { + case 3: dest[j++]=0; break; // marker bit which should be a 0 + case 2: dest[j++]=1; break; // marker bit which should be a 1 + default: + dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1; + break; } bitCnt += pLen; parityWd = 0; @@ -258,9 +262,9 @@ 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; } @@ -460,10 +464,10 @@ 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; @@ -485,8 +489,9 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow size_t numBits = 0; // 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 with anywhere + // 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 @@ -494,23 +499,24 @@ 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) + 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; @@ -520,6 +526,7 @@ 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) { @@ -529,8 +536,9 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint32_t n=1; for( idx=1; idx < size; idx++) { n++; - if (dest[idx]==lastval) continue; + if (dest[idx]==lastval) continue; //skip until we hit a transition + //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; @@ -539,6 +547,7 @@ 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; @@ -680,6 +689,19 @@ int VikingDemod_AM(uint8_t *dest, size_t *size) { return (int) startIdx; } +// find presco preamble 0x10D in already demoded data +int PrescoDemod(uint8_t *dest, size_t *size) { + //make sure buffer has data + if (*size < 64*2) return -2; + + size_t startIdx = 0; + uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0}; + uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx); + if (errChk == 0) return -4; //preamble not found + //return start position + 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) @@ -1478,8 +1500,8 @@ 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++){ @@ -1529,11 +1551,12 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { uint8_t fndClk[] = {8,16,32,40,50,64,128}; int clk = 0; int tol = 0; - int i, j, skip, start, end, low, high, minClk; + int i, j, skip, start, end, low, high, minClk, waveStart; bool complete = false; int tmpbuff[bufsize / 64]; + int waveLen[bufsize / 64]; size_t testsize = (bufsize < 512) ? bufsize : 512; - //int phaseoff = 0; + int phaseoff = 0; high = low = 128; memset(tmpbuff, 0, sizeof(tmpbuff)); @@ -1541,7 +1564,6 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting"); return false; //just noise } - i = 0; j = 0; minClk = 255; @@ -1560,11 +1582,14 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { start= i; while ((buffer[i] < high) && (i < bufsize)) ++i; + //first high point for this wave + waveStart = i; while ((buffer[i] > low) && (i < bufsize)) ++i; if (j >= (bufsize/64)) { break; } + waveLen[j] = i - waveStart; //first high to first low tmpbuff[j++] = i - start; if (i-start < minClk && i < bufsize) { minClk = i - start; @@ -1592,10 +1617,10 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { start = -1; for (i = 0; i < j - 4; ++i) { skip += tmpbuff[i]; - if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) { //1 to 2 clocks depending on 2 bits prior - if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol) { //2 clocks - if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol) { //1 1/2 to 2 clocks - if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= (clk*3)/2+tol) { //1 to 1 1/2 clocks for end of ST + first bit + if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior + if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2 + if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave + if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit start = i + 3; break; } @@ -1608,7 +1633,11 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting"); return false; } - + if (waveLen[i+2] > clk*1+tol) + phaseoff = 0; + else + phaseoff = clk/2; + // skip over the remainder of ST skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point @@ -1617,9 +1646,9 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { for (i += 3; i < j - 4; ++i) { end += tmpbuff[i]; if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) { //1 to 2 clocks depending on 2 bits prior - if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol) { //2 clocks - if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol) { //1 1/2 to 2 clocks - if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= (clk*3)/2+tol) { //1 to 1 1/2 clocks for end of ST + first bit + if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2 + if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave + if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit complete = true; break; } @@ -1627,12 +1656,13 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) { } } } + end -= phaseoff; //didn't find second ST - ERROR if (!complete) { if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting"); return false; } - if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d", skip, end, end-skip, clk, (end-skip)/clk); + if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d, phaseoff: %d", skip, end, end-skip, clk, (end-skip)/clk, phaseoff); //now begin to trim out ST so we can use normal demod cmds start = skip; size_t datalen = end - start; @@ -1654,7 +1684,7 @@ 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; @@ -1669,7 +1699,7 @@ 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;