+ if (start == *size - 250 + 1) {
+ // did not find start sequence
+ return -1;
+ }
+ // Inverting signal if needed
+ if (first == 1) {
+ for (i = start; i < *size; i++) {
+ bitStream[i] = !bitStream[i];
+ }
+ *invert = 1;
+ }else *invert=0;
+
+ int iii;
+ //found start once now test length by finding next one
+ for (ii=start+29; ii <= *size - 250; ii++) {
+ first2 = bitStream[ii];
+ for (iii = ii; iii < ii + long_wait; iii++) {
+ if (bitStream[iii] != first2) {
+ break;
+ }
+ }
+ if (iii == (ii + long_wait)) {
+ break;
+ }
+ }
+ if (ii== *size - 250 + 1){
+ // did not find second start sequence
+ return -2;
+ }
+ bitCnt=ii-start;
+
+ // Dumping UID
+ i = start;
+ for (ii = 0; ii < bitCnt; ii++) {
+ bitStream[ii] = bitStream[i++];
+ }
+ *size=bitCnt;
+ return 1;
+}
+
+// by marshmellow - demodulate PSK1 wave or NRZ wave (both similar enough)
+// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
+int pskNRZrawDemod(uint8_t *dest, size_t *size, int *clk, int *invert)
+{
+ if (justNoise(dest, *size)) return -1;
+ pskCleanWave(dest,*size);
+ int clk2 = DetectpskNRZClock(dest, *size, *clk);
+ *clk=clk2;
+ uint32_t i;
+ int high, low, ans;
+ ans = getHiLo(dest, 1260, &high, &low, 75, 80); //25% fuzz on high 20% fuzz on low
+ if (ans<1) return -2; //just noise
+ uint32_t gLen = *size;
+ //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
+ int lastBit = 0; //set first clock check
+ uint32_t bitnum = 0; //output counter
+ uint8_t tol = 1; //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 = 2; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
+ uint32_t iii = 0;
+ uint8_t errCnt =0;
+ uint32_t bestStart = *size;
+ uint32_t maxErr = (*size/1000);
+ uint32_t bestErrCnt = maxErr;
+ uint8_t curBit=0;
+ uint8_t bitHigh=0;
+ uint8_t ignorewin=*clk/8;
+ //PrintAndLog("DEBUG - lastbit - %d",lastBit);
+ //loop to find first wave that works - align to clock
+ for (iii=0; iii < gLen; ++iii){
+ if ((dest[iii]>=high) || (dest[iii]<=low)){
+ lastBit=iii-*clk;
+ //loop through to see if this start location works
+ for (i = iii; i < *size; ++i) {
+ //if we found a high bar and we are at a clock bit
+ if ((dest[i]>=high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
+ bitHigh=1;
+ lastBit+=*clk;
+ ignorewin=*clk/8;
+ bitnum++;
+ //else if low bar found and we are at a clock point
+ }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
+ bitHigh=1;
+ lastBit+=*clk;
+ ignorewin=*clk/8;
+ bitnum++;
+ //else if no bars found
+ }else if(dest[i] < high && dest[i] > low) {
+ if (ignorewin==0){
+ bitHigh=0;
+ }else ignorewin--;
+ //if we are past a clock point
+ if (i >= lastBit+*clk+tol){ //clock val
+ lastBit+=*clk;
+ bitnum++;
+ }
+ //else if bar found but we are not at a clock bit and we did not just have a clock bit
+ }else if ((dest[i]>=high || dest[i]<=low) && (i<lastBit+*clk-tol || i>lastBit+*clk+tol) && (bitHigh==0)){
+ //error bar found no clock...
+ errCnt++;
+ }
+ if (bitnum>=1000) break;
+ }
+ //we got more than 64 good bits and not all errors
+ if ((bitnum > (64+errCnt)) && (errCnt < (maxErr))) {
+ //possible good read
+ if (errCnt == 0){
+ bestStart = iii;
+ bestErrCnt = errCnt;
+ break; //great read - finish
+ }
+ if (errCnt < bestErrCnt){ //set this as new best run
+ bestErrCnt = errCnt;
+ bestStart = iii;
+ }
+ }
+ }
+ }
+ if (bestErrCnt < maxErr){
+ //best run is good enough set to best run and set overwrite BinStream
+ iii=bestStart;
+ lastBit=bestStart-*clk;
+ bitnum=0;
+ for (i = iii; i < *size; ++i) {
+ //if we found a high bar and we are at a clock bit
+ if ((dest[i] >= high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
+ bitHigh=1;
+ lastBit+=*clk;
+ curBit=1-*invert;
+ dest[bitnum]=curBit;
+ ignorewin=*clk/8;
+ bitnum++;
+ //else if low bar found and we are at a clock point
+ }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
+ bitHigh=1;
+ lastBit+=*clk;
+ curBit=*invert;
+ dest[bitnum]=curBit;
+ ignorewin=*clk/8;
+ bitnum++;
+ //else if no bars found
+ }else if(dest[i]<high && dest[i]>low) {
+ if (ignorewin==0){
+ bitHigh=0;
+ }else ignorewin--;
+ //if we are past a clock point
+ if (i>=lastBit+*clk+tol){ //clock val
+ lastBit+=*clk;
+ dest[bitnum]=curBit;
+ bitnum++;
+ }
+ //else if bar found but we are not at a clock bit and we did not just have a clock bit
+ }else if ((dest[i]>=high || dest[i]<=low) && ((i<lastBit+*clk-tol) || (i>lastBit+*clk+tol)) && (bitHigh==0)){
+ //error bar found no clock...
+ bitHigh=1;
+ dest[bitnum]=77;
+ bitnum++;
+ errCnt++;
+ }
+ if (bitnum >=1000) break;
+ }
+ *size=bitnum;
+ } else{
+ *size=bitnum;
+ *clk=bestStart;
+ return -1;
+ }
+
+ if (bitnum>16){
+ *size=bitnum;
+ } else return -1;
+ return errCnt;
+}
+
+//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 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};
+ uint8_t rfLensFnd = 0;
+ uint8_t lastFCcnt=0;
+ uint32_t fcCounter = 0;
+ uint16_t rfCounter = 0;
+ uint8_t firstBitFnd = 0;
+ size_t i;
+
+ uint8_t fcTol = (uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
+ rfLensFnd=0;
+ fcCounter=0;
+ rfCounter=0;
+ firstBitFnd=0;
+ //PrintAndLog("DEBUG: fcTol: %d",fcTol);
+ // prime i to first up transition
+ for (i = 1; i < size-1; i++)
+ if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
+ break;
+
+ for (; i < size-1; i++){
+ if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]){
+ // new peak
+ fcCounter++;
+ rfCounter++;
+ // if we got less than the small fc + tolerance then set it to the small fc
+ if (fcCounter < fcLow+fcTol)
+ fcCounter = fcLow;
+ else //set it to the large fc
+ fcCounter = fcHigh;
+
+ //look for bit clock (rf/xx)
+ if ((fcCounter<lastFCcnt || fcCounter>lastFCcnt)){
+ //not the same size as the last wave - start of new bit sequence
+
+ if (firstBitFnd>1){ //skip first wave change - probably not a complete bit
+ for (int ii=0; ii<15; ii++){
+ if (rfLens[ii]==rfCounter){
+ rfCnts[ii]++;
+ rfCounter=0;
+ break;
+ }
+ }
+ if (rfCounter>0 && rfLensFnd<15){
+ //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
+ rfCnts[rfLensFnd]++;
+ rfLens[rfLensFnd++]=rfCounter;
+ }
+ } else {
+ firstBitFnd++;
+ }
+ rfCounter=0;
+ lastFCcnt=fcCounter;
+ }
+ fcCounter=0;
+ } else {
+ // count sample
+ fcCounter++;
+ rfCounter++;
+ }
+ }
+ uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
+
+ for (i=0; i<15; i++){
+ //PrintAndLog("DEBUG: RF %d, cnts %d",rfLens[i], rfCnts[i]);
+ //get highest 2 RF values (might need to get more values to compare or compare all?)
+ if (rfCnts[i]>rfCnts[rfHighest]){
+ rfHighest3=rfHighest2;
+ rfHighest2=rfHighest;
+ rfHighest=i;
+ } else if(rfCnts[i]>rfCnts[rfHighest2]){
+ rfHighest3=rfHighest2;
+ rfHighest2=i;
+ } else if(rfCnts[i]>rfCnts[rfHighest3]){
+ rfHighest3=i;
+ }
+ }
+ // set allowed clock remainder tolerance to be 1 large field clock length+1
+ // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
+ uint8_t tol1 = fcHigh+1;
+
+ //PrintAndLog("DEBUG: hightest: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
+
+ // loop to find the highest clock that has a remainder less than the tolerance
+ // compare samples counted divided by
+ int ii=7;
+ for (; ii>=0; ii--){
+ if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){
+ if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){
+ if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){
+ break;
+ }
+ }
+ }
+ }
+
+ if (ii<0) return 0; // oops we went too far
+
+ return clk[ii];
+}
+
+//by marshmellow
+//countFC is to detect the field clock lengths.
+//counts and returns the 2 most common wave lengths
+uint16_t countFC(uint8_t *BitStream, size_t size)
+{
+ uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0};
+ uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0};
+ uint8_t fcLensFnd = 0;
+ uint8_t lastFCcnt=0;
+ uint32_t fcCounter = 0;
+ size_t i;
+
+ // prime i to first up transition
+ for (i = 1; i < size-1; i++)
+ if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
+ break;
+
+ for (; i < size-1; i++){
+ if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
+ // new up transition
+ fcCounter++;
+
+ //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
+ if (lastFCcnt==5 && fcCounter==9) fcCounter--;
+ //if odd and not rc/5 add one (for when we get a fc 9 instead of 10)
+ if ((fcCounter==9 && fcCounter & 1) || fcCounter==4) fcCounter++;
+
+ // save last field clock count (fc/xx)
+ // find which fcLens to save it to:
+ for (int ii=0; ii<10; ii++){
+ if (fcLens[ii]==fcCounter){
+ fcCnts[ii]++;
+ fcCounter=0;
+ break;
+ }
+ }
+ if (fcCounter>0 && fcLensFnd<10){
+ //add new fc length
+ fcCnts[fcLensFnd]++;
+ fcLens[fcLensFnd++]=fcCounter;
+ }
+ fcCounter=0;
+ } else {
+ // count sample
+ fcCounter++;
+ }
+ }
+
+ uint8_t best1=9, best2=9, best3=9;
+ uint16_t maxCnt1=0;
+ // go through fclens and find which ones are bigest 2
+ for (i=0; i<10; i++){
+ // PrintAndLog("DEBUG: FC %d, Cnt %d, Errs %d",fcLens[i],fcCnts[i],errCnt);
+ // get the 3 best FC values
+ if (fcCnts[i]>maxCnt1) {
+ best3=best2;
+ best2=best1;
+ maxCnt1=fcCnts[i];
+ best1=i;
+ } else if(fcCnts[i]>fcCnts[best2]){
+ best3=best2;
+ best2=i;
+ } else if(fcCnts[i]>fcCnts[best3]){
+ best3=i;
+ }
+ }
+ uint8_t fcH=0, fcL=0;
+ if (fcLens[best1]>fcLens[best2]){
+ fcH=fcLens[best1];
+ fcL=fcLens[best2];
+ } else{
+ fcH=fcLens[best2];
+ fcL=fcLens[best1];
+ }
+
+ // TODO: take top 3 answers and compare to known Field clocks to get top 2
+
+ uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
+ // PrintAndLog("DEBUG: Best %d best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]);
+
+ return fcs;
projects / proxmark3-svn / blobdiff