uint8_t FmtLen = 10; // sets of 4 bits = end data
*startIdx = 0;
errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx);
- if (errChk == 0 || *size < 64) return 0;
- if (*size == 110) FmtLen = 22; // 22 sets of 4 bits
+ if ( errChk == 0 || (*size != 64 && *size != 128) ) return 0;
+ if (*size == 128) FmtLen = 22; // 22 sets of 4 bits
//skip last 4bit parity row for simplicity
*size = removeParity(BitStream, *startIdx + sizeof(preamble), 5, 0, FmtLen * 5);
//by marshmellow
//demodulates strong heavily clipped samples
-int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
+int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low, int *startIdx)
{
- size_t bitCnt=0, smplCnt=0, errCnt=0;
- uint8_t waveHigh = 0;
- for (size_t i=0; i < *size; i++){
+ *startIdx=0;
+ size_t bitCnt=0, smplCnt=1, errCnt=0;
+ bool waveHigh = (BinStream[0] >= high);
+ for (size_t i=1; i < *size; i++){
if (BinStream[i] >= high && waveHigh){
smplCnt++;
} else if (BinStream[i] <= low && !waveHigh){
if (smplCnt > clk + (clk/4)+1) { //too many samples
errCnt++;
if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
- BinStream[bitCnt++]=7;
+ BinStream[bitCnt++] = 7;
} else if (waveHigh) {
BinStream[bitCnt++] = invert;
BinStream[bitCnt++] = invert;
BinStream[bitCnt++] = invert ^ 1;
BinStream[bitCnt++] = invert ^ 1;
}
- waveHigh ^= 1;
+ if (*startIdx==0) *startIdx = i-clk;
+ waveHigh = !waveHigh;
smplCnt = 0;
- } else if (smplCnt > (clk/2) - (clk/4)-1) {
+ } else if (smplCnt > (clk/2) - (clk/4)-1) { //half clock
if (waveHigh) {
BinStream[bitCnt++] = invert;
} else if (!waveHigh) {
BinStream[bitCnt++] = invert ^ 1;
}
- waveHigh ^= 1;
+ if (*startIdx==0) *startIdx = i-(clk/2);
+ waveHigh = !waveHigh;
smplCnt = 0;
- } else if (!bitCnt) {
- //first bit
- waveHigh = (BinStream[i] >= high);
- smplCnt = 1;
} else {
smplCnt++;
//transition bit oops
//by marshmellow
//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
-int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType)
-{
+int askdemod_ext(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType, int *startIdx) {
if (*size==0) return -1;
int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
if (*clk==0 || start < 0) return -3;
if (amp==1) askAmp(BinStream, *size);
if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp);
+ //start pos from detect ask clock is 1/2 clock offset
+ // NOTE: can be negative (demod assumes rest of wave was there)
+ *startIdx = start - (*clk/2);
uint8_t initLoopMax = 255;
if (initLoopMax > *size) initLoopMax = *size;
// Detect high and lows
// if clean clipped waves detected run alternate demod
if (DetectCleanAskWave(BinStream, *size, high, low)) {
if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod");
- errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
- if (askType) //askman
- return manrawdecode(BinStream, size, 0);
- else //askraw
+ errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low, startIdx);
+ if (askType) { //askman
+ uint8_t alignPos = 0;
+ errCnt = manrawdecode(BinStream, size, 0, &alignPos);
+ *startIdx += *clk/2 * alignPos;
+ if (g_debugMode) prnt("DEBUG ASK CLEAN: startIdx %i, alignPos %u", *startIdx, alignPos);
+ return errCnt;
+ } else { //askraw
return errCnt;
+ }
}
+ if (g_debugMode) prnt("DEBUG ASK WEAK: startIdx %i", *startIdx);
if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod");
int lastBit; //set first clock check - can go negative
size_t i, bitnum = 0; //output counter
uint8_t midBit = 0;
- uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
+ uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
if (*clk <= 32) tol = 1; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
size_t MaxBits = 3072; //max bits to collect
lastBit = start - *clk;
return errCnt;
}
+int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) {
+ int start = 0;
+ return askdemod_ext(BinStream, size, clk, invert, maxErr, amp, askType, &start);
+}
//by marshmellow
//take 10 and 01 and manchester decode
//run through 2 times and take least errCnt
-int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert)
+int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert, uint8_t *alignPos)
{
uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
size_t i, ii;
}
errCnt=0;
}
+ *alignPos=bestRun;
//decode
for (i=bestRun; i < *size-3; i+=2){
if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
}
//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 fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow, int *startIdx)
{
size_t last_transition = 0;
size_t idx = 1;
//find start of modulating data in trace
idx = findModStart(dest, size, threshold_value, fchigh);
-
// Need to threshold first sample
if(dest[idx] < threshold_value) dest[0] = 0;
else dest[0] = 1;
- idx++;
+ last_transition = idx;
+ idx++;
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 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 < size-20; idx++) {
+ for(; idx < size; idx++) {
// threshold current value
-
if (dest[idx] < threshold_value) dest[idx] = 0;
else dest[idx] = 1;
//do nothing with extra garbage
} 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))){
+ if (numBits > 1 && LastSample > (fchigh-2) && (preLastSample < (fchigh-1))){
dest[numBits-1]=1;
}
dest[numBits++]=1;
-
+ if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow;
} else if (currSample > (fchigh+1) && numBits < 3) { //12 + and first two bit = unusable garbage
//do nothing with beginning garbage and reset.. should be rare..
numBits = 0;
} 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;
+ if (numBits > 0 && *startIdx==0) *startIdx = idx - fclow;
} else { //9+ = 10 sample waves (or 6+ = 7)
dest[numBits++]=0;
+ if (numBits > 0 && *startIdx==0) *startIdx = idx - fchigh;
}
last_transition = idx;
}
//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)
+ uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx)
{
uint8_t lastval=dest[0];
size_t idx=0;
n++;
if (dest[idx]==lastval) continue; //skip until we hit a transition
- //find out how many bits (n) we collected
+ //find out how many bits (n) we collected (use 1/2 clk tolerance)
//if lastval was 1, we have a 1->0 crossing
if (dest[idx-1]==1) {
n = (n * fclow + rfLen/2) / rfLen;
n = (n * fchigh + rfLen/2) / rfLen;
}
if (n == 0) n = 1;
+
+ //first transition - save startidx
+ if (numBits == 0) {
+ if (lastval == 1) { //high to low
+ *startIdx += (fclow * idx) - (n*rfLen);
+ if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fclow*idx %i, n*rflen %u", *startIdx, fclow*(idx), n*rfLen);
+ } else {
+ *startIdx += (fchigh * idx) - (n*rfLen);
+ if (g_debugMode==2) prnt("DEBUG FSK: startIdx %i, fchigh*idx %i, n*rflen %u", *startIdx, fchigh*(idx), n*rfLen);
+ }
+ }
//add to our destination the bits we collected
memset(dest+numBits, dest[idx-1]^invert , n);
//by marshmellow (from holiman's base)
// full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
-int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow)
-{
+int fskdemod_ext(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) {
// FSK demodulator
- size = fsk_wave_demod(dest, size, fchigh, fclow);
- size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow);
+ size = fsk_wave_demod(dest, size, fchigh, fclow, startIdx);
+ size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow, startIdx);
return size;
}
+int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow) {
+ int startIdx=0;
+ return fskdemod_ext(dest, size, rfLen, invert, fchigh, fclow, &startIdx);
+}
+
// loop to get raw HID waveform then FSK demodulate the TAG ID from it
int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
{
// by marshmellow
// to help detect clocks on heavily clipped samples
// based on count of low to low
-int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
-{
+int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low, int *clock) {
uint8_t fndClk[] = {8,16,32,40,50,64,128};
size_t startwave;
size_t i = 100;
size_t minClk = 255;
+ int shortestWaveIdx = 0;
// get to first full low to prime loop and skip incomplete first pulse
while ((dest[i] < high) && (i < size))
++i;
// measure from low to low
while ((dest[i] > low) && (i < size))
++i;
- startwave= i;
+ startwave = i;
while ((dest[i] < high) && (i < size))
++i;
while ((dest[i] > low) && (i < size))
++i;
//get minimum measured distance
- if (i-startwave < minClk && i < size)
+ if (i-startwave < minClk && i < size) {
minClk = i - startwave;
+ shortestWaveIdx = startwave;
+ }
}
// set clock
if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk);
for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
- if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1)
- return fndClk[clkCnt];
+ if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1) {
+ *clock = fndClk[clkCnt];
+ return shortestWaveIdx;
+ }
}
return 0;
}
//test for large clean peaks
if (!clockFnd){
if (DetectCleanAskWave(dest, size, peak, low)==1){
- int ans = DetectStrongAskClock(dest, size, peak, low);
- if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %d",ans);
- for (i=clkEnd-1; i>0; i--){
- if (clk[i] == ans) {
- *clock = ans;
- //clockFnd = i;
- return 0; // for strong waves i don't use the 'best start position' yet...
- //break; //clock found but continue to find best startpos [not yet]
- }
+ int ans = DetectStrongAskClock(dest, size, peak, low, clock);
+ if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %i, ShortestWave: %i",clock, ans);
+ if (ans > 0) {
+ return ans; //return shortest wave start position
}
}
}
//by marshmellow
//detect psk clock by reading each phase shift
// a phase shift is determined by measuring the sample length of each wave
-int DetectPSKClock(uint8_t dest[], size_t size, int clock)
-{
+int DetectPSKClock_ext(uint8_t dest[], size_t size, int clock, int *firstPhaseShift) {
uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
uint16_t loopCnt = 4096; //don't need to loop through entire array...
if (size == 0) return 0;
}
}
}
+ *firstPhaseShift = firstFullWave;
if (g_debugMode ==2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
-
//test each valid clock from greatest to smallest to see which lines up
for(clkCnt=7; clkCnt >= 1 ; clkCnt--){
lastClkBit = firstFullWave; //set end of wave as clock align
return clk[best];
}
+int DetectPSKClock(uint8_t dest[], size_t size, int clock) {
+ int firstPhaseShift = 0;
+ return DetectPSKClock_ext(dest, size, clock, &firstPhaseShift);
+}
+
int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){
//find shortest transition from high to low
size_t i = 0;
//by marshmellow
//detect nrz clock by reading #peaks vs no peaks(or errors)
-int DetectNRZClock(uint8_t dest[], size_t size, int clock)
-{
+int DetectNRZClock_ext(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...
uint8_t ignoreWindow = 4;
bool lastPeakHigh = 0;
int lastBit = 0;
+ size_t bestStart[]={0,0,0,0,0,0,0,0,0};
peakcnt=0;
//test each valid clock from smallest to greatest to see which lines up
for(clkCnt=0; clkCnt < 8; ++clkCnt){
}
}
if(peakcnt>peaksdet[clkCnt]) {
+ bestStart[clkCnt]=ii;
peaksdet[clkCnt]=peakcnt;
}
}
}
if (g_debugMode==2) prnt("DEBUG NRZ: Clk: %d, peaks: %d, maxPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],maxPeak, clk[best], lowestTransition);
}
-
+ *clockStartIdx = bestStart[best];
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
// convert psk1 demod to psk2 demod
// only transition waves are 1s
// 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(uint8_t *dest, size_t *size, int *clk, int *invert){
+int nrzRawDemod_ext(uint8_t *dest, size_t *size, int *clk, int *invert, int *startIdx) {
if (justNoise(dest, *size)) return -1;
*clk = DetectNRZClock(dest, *size, *clk);
if (*clk==0) return -2;
if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) {
memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk);
numBits += (i - lastBit + (*clk/4)) / *clk;
+ if (lastBit == 0) {
+ *startIdx = i - (numBits * *clk);
+ if (g_debugMode==2) prnt("DEBUG NRZ: startIdx %i", *startIdx);
+ }
lastBit = i-1;
}
}
*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);
+}
//by marshmellow
//detects the bit clock for FSK given the high and low Field Clocks
-uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow)
-{
+uint8_t detectFSKClk_ext(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow, int *firstClockEdge) {
uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
rfLens[rfLensFnd++] = rfCounter;
}
} else {
+ *firstClockEdge = i;
firstBitFnd++;
}
rfCounter=0;
return clk[ii];
}
+uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow) {
+ int firstClockEdge = 0;
+ return detectFSKClk_ext(BitStream, size, fcHigh, fcLow, &firstClockEdge);
+}
+
//by marshmellow
//countFC is to detect the field clock lengths.
//counts and returns the 2 most common wave lengths
//by marshmellow - demodulate PSK1 wave
//uses wave lengths (# Samples)
-int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
-{
+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<loopCnt) loopCnt = *size;
//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;
}
}
//advance bits
numBits += (firstFullWave / *clock);
+ *startIdx = firstFullWave - (*clock * numBits)+2;
//set start of wave as clock align
lastClkBit = firstFullWave;
- if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u",firstFullWave,fullWaveLen);
+ if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u, startIdx %i",firstFullWave,fullWaveLen, *startIdx);
if (g_debugMode==2) prnt("DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);
waveStart = 0;
dest[numBits++] = curPhase; //set first read bit
waveEnd = i+1;
waveLenCnt = waveEnd-waveStart;
lastAvgWaveVal = avgWaveVal/waveLenCnt;
- if (waveLenCnt > fc){
+ 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);
return errCnt;
}
+int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) {
+ int startIdx = 0;
+ return pskRawDemod_ext(dest, size, clock, invert, &startIdx);
+}
+
//by marshmellow
//attempt to identify a Sequence Terminator in ASK modulated raw wave
-bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
+bool DetectST_ext(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststart, size_t *stend) {
size_t bufsize = *size;
//need to loop through all samples and identify our clock, look for the ST pattern
uint8_t fndClk[] = {8,16,32,40,50,64,128};
size_t newloc = 0;
i=0;
if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen);
-
+ bool firstrun = true;
// 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 due to signal loss... (and we cut out the start of wave high part)
buffer[dataloc] = buffer[dataloc+2];
buffer[dataloc+1] = buffer[dataloc+2];
}
+ if (firstrun) {
+ *stend = dataloc;
+ *ststart = dataloc-(clk*4);
+ firstrun=false;
+ }
for (i=0; i<datalen; ++i) {
if (i+newloc < bufsize) {
if (i+newloc < dataloc)
*size = newloc;
return true;
}
+
+bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
+ size_t ststart = 0, stend = 0;
+ return DetectST_ext(buffer, size, foundclock, &ststart, &stend);
+}
+
+// by iceman
+// find Visa2000 preamble in already demoded data
+int Visa2kDemod_AM(uint8_t *dest, size_t *size) {
+ if (*size < 96) return -1; //make sure buffer has data
+ size_t startIdx = 0;
+ uint8_t preamble[] = {0,1,0,1,0,1,1,0,0,1,0,0,1,0,0,1,0,1,0,1,0,0,1,1,0,0,1,1,0,0,1,0};
+ if (preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx) == 0)
+ return -2; //preamble not found
+ if (*size != 96) return -3; //wrong demoded size
+ //return start position
+ return (int)startIdx;
+}
projects / proxmark3-svn / blobdiff