+
+//by marshmellow
+//detect psk clock by reading #peaks vs no peaks(or errors)
+int DetectpskNRZClock(uint8_t dest[], size_t size, int clock)
+{
+ int i=0;
+ int peak=0;
+ int low=128;
+ int clk[]={16,32,40,50,64,100,128,256};
+ int loopCnt = 2048; //don't need to loop through entire array...
+ if (size<loopCnt) loopCnt = size;
+
+ //if we already have a valid clock quit
+ for (; i < 8; ++i)
+ if (clk[i] == clock) return clock;
+
+ //get high and low peak
+ for (i=0; i < loopCnt; ++i){
+ if(dest[i] > peak){
+ peak = dest[i];
+ }
+ if(dest[i] < low){
+ low = dest[i];
+ }
+ }
+ peak=(int)(((peak-128)*.90)+128);
+ low= (int)(((low-128)*.90)+128);
+ //PrintAndLog("DEBUG: peak: %d, low: %d",peak,low);
+ int ii;
+ uint8_t clkCnt;
+ uint8_t tol = 0;
+ int peakcnt=0;
+ int errCnt=0;
+ int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
+ int peaksdet[]={0,0,0,0,0,0,0,0,0};
+ //test each valid clock from smallest to greatest to see which lines up
+ for(clkCnt=0; clkCnt < 6; ++clkCnt){
+ if (clk[clkCnt] == 32){
+ tol=0;
+ }else{
+ tol=0;
+ }
+ //try lining up the peaks by moving starting point (try first 256)
+ for (ii=0; ii< loopCnt; ++ii){
+ if ((dest[ii] >= peak) || (dest[ii] <= low)){
+ errCnt=0;
+ peakcnt=0;
+ // now that we have the first one lined up test rest of wave array
+ for (i=0; i < ((int)(size/clk[clkCnt])-1); ++i){
+ if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
+ peakcnt++;
+ }else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){
+ peakcnt++;
+ }else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){
+ peakcnt++;
+ }else{ //error no peak detected
+ errCnt++;
+ }
+ }
+ if(peakcnt>peaksdet[clkCnt]) {
+ peaksdet[clkCnt]=peakcnt;
+ bestErr[clkCnt]=errCnt;
+ }
+ }
+ }
+ }
+ int iii=0;
+ int best=0;
+ //int ratio2; //debug
+ int ratio;
+ //int bits;
+ for (iii=0; iii < 7; ++iii){
+ ratio=1000;
+ //ratio2=1000; //debug
+ //bits=size/clk[iii]; //debug
+ if (peaksdet[iii] > 0){
+ ratio=bestErr[iii]/peaksdet[iii];
+ if (((bestErr[best]/peaksdet[best]) > (ratio)+1)){
+ best = iii;
+ }
+ //ratio2=bits/peaksdet[iii]; //debug
+ }
+ //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d, ratio: %d, bits: %d, peakbitr: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best],ratio, bits,ratio2);
+ }
+ return clk[best];
+}
+
+//by marshmellow (attempt to get rid of high immediately after a low)
+void pskCleanWave(uint8_t *bitStream, size_t size)
+{
+ int i;
+ int low=128;
+ int high=0;
+ int gap = 4;
+ // int loopMax = 2048;
+ int newLow=0;
+ int newHigh=0;
+ for (i=0; i < size; ++i){
+ if (bitStream[i] < low) low=bitStream[i];
+ if (bitStream[i] > high) high=bitStream[i];
+ }
+ high = (int)(((high-128)*.80)+128);
+ low = (int)(((low-128)*.90)+128);
+ //low = (uint8_t)(((int)(low)-128)*.80)+128;
+ for (i=0; i < size; ++i){
+ if (newLow == 1){
+ bitStream[i]=low+8;
+ gap--;
+ if (gap == 0){
+ newLow=0;
+ gap=4;
+ }
+ }else if (newHigh == 1){
+ bitStream[i]=high-8;
+ gap--;
+ if (gap == 0){
+ newHigh=0;
+ gap=4;
+ }
+ }
+ if (bitStream[i] <= low) newLow=1;
+ if (bitStream[i] >= high) newHigh=1;
+ }
+ return;
+}
+
+
+//redesigned by marshmellow adjusted from existing decode functions
+//indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
+int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
+{
+ //26 bit 40134 format (don't know other formats)
+ int i;
+ int long_wait;
+ long_wait = 29;//29 leading zeros in format
+ int start;
+ int first = 0;
+ int first2 = 0;
+ int bitCnt = 0;
+ int ii;
+ // Finding the start of a UID
+ for (start = 0; start <= *size - 250; start++) {
+ first = bitStream[start];
+ for (i = start; i < start + long_wait; i++) {
+ if (bitStream[i] != first) {
+ break;
+ }
+ }
+ if (i == (start + long_wait)) {
+ break;
+ }
+ }
+ if (start == *size - 250 + 1) {
+ // did not find start sequence
+ return -1;
+ }
+ //found start once now test length by finding next one
+ // Inverting signal if needed
+ if (first == 1) {
+ for (i = start; i < *size; i++) {
+ bitStream[i] = !bitStream[i];
+ }
+ *invert = 1;
+ }else *invert=0;
+
+ int iii;
+ 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 PSK wave or NRZ wave (both similar enough)
+//peaks switch 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)
+{
+ pskCleanWave(dest,*size);
+ int clk2 = DetectpskNRZClock(dest, *size, *clk);
+ *clk=clk2;
+ uint32_t i;
+ uint8_t high=0, low=128;
+ uint32_t gLen = *size;
+ if (gLen > 1280) gLen=1280;
+ // get high
+ for (i=0; i < gLen; ++i){
+ if (dest[i] > high) high = dest[i];
+ if (dest[i] < low) low = dest[i];
+ }
+ //fudge high/low bars by 25%
+ high = (uint8_t)((((int)(high)-128)*.75)+128);
+ low = (uint8_t)((((int)(low)-128)*.80)+128);
+
+ //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 = 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=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 midBit=0;
+ 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 (bestStart == iii) break; //if current run == bestErrCnt run (after exhausted testing) then 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;
+}
+
projects / proxmark3-svn / blobdiff