#include <string.h>
#include "lfdemod.h"
+
+uint8_t justNoise(uint8_t *BitStream, size_t size)
+{
+ static const uint8_t THRESHOLD = 123;
+ //test samples are not just noise
+ uint8_t justNoise1 = 1;
+ for(size_t idx=0; idx < size && justNoise1 ;idx++){
+ justNoise1 = BitStream[idx] < THRESHOLD;
+ }
+ return justNoise1;
+}
+
//by marshmellow
//get high and low with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise
int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo)
return 1;
}
+// by marshmellow
+// pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
+// returns 1 if passed
+uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
+{
+ uint8_t ans = 0;
+ for (uint8_t i = 0; i < bitLen; i++){
+ ans ^= ((bits >> i) & 1);
+ }
+ //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
+ return (ans == pType);
+}
+
+//by marshmellow
+//search for given preamble in given BitStream and return startIndex and length
+uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx)
+{
+ uint8_t foundCnt=0;
+ for (int idx=0; idx < *size - pLen; idx++){
+ if (memcmp(BitStream+idx, preamble, pLen) == 0){
+ //first index found
+ foundCnt++;
+ if (foundCnt == 1){
+ *startIdx = idx;
+ }
+ if (foundCnt == 2){
+ *size = idx - *startIdx;
+ return 1;
+ }
+ }
+ }
+ return 0;
+}
+
+
//by marshmellow
//takes 1s and 0s and searches for EM410x format - output EM ID
uint64_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx)
{
- //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
- // otherwise could be a void with no arguments
- //set defaults
- uint64_t lo=0;
- uint32_t i = 0;
- if (BitStream[10]>1){ //allow only 1s and 0s
- // PrintAndLog("no data found");
- return 0;
- }
- uint8_t parityTest=0;
- // 111111111 bit pattern represent start of frame
- uint8_t frame_marker_mask[] = {1,1,1,1,1,1,1,1,1};
- uint32_t idx = 0;
- uint32_t ii=0;
- uint8_t resetCnt = 0;
- while( (idx + 64) < *size) {
- restart:
- // search for a start of frame marker
- if ( memcmp(BitStream+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
- { // frame marker found
- *startIdx=idx;
- idx+=9;
- for (i=0; i<10;i++){
- for(ii=0; ii<5; ++ii){
- parityTest ^= BitStream[(i*5)+ii+idx];
- }
- if (!parityTest){ //even parity
- parityTest=0;
- for (ii=0; ii<4;++ii){
- lo=(lo<<1LL)|(BitStream[(i*5)+ii+idx]);
- }
- //PrintAndLog("DEBUG: EM parity passed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d,lo: %d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1],lo);
- }else {//parity failed
- //PrintAndLog("DEBUG: EM parity failed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1]);
- parityTest=0;
- idx-=8;
- if (resetCnt>5)return 0; //try 5 times
- resetCnt++;
- goto restart;//continue;
- }
- }
- //skip last 5 bit parity test for simplicity.
- *size = 64;
- return lo;
- }else{
- idx++;
- }
- }
- return 0;
+ //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
+ // otherwise could be a void with no arguments
+ //set defaults
+ uint64_t lo=0;
+ uint32_t i = 0;
+ if (BitStream[1]>1){ //allow only 1s and 0s
+ // PrintAndLog("no data found");
+ return 0;
+ }
+ // 111111111 bit pattern represent start of frame
+ uint8_t preamble[] = {1,1,1,1,1,1,1,1,1};
+ uint32_t idx = 0;
+ uint32_t parityBits = 0;
+ uint8_t errChk = 0;
+ *startIdx = 0;
+ for (uint8_t extraBitChk=0; extraBitChk<5; extraBitChk++){
+ errChk = preambleSearch(BitStream+extraBitChk+*startIdx, preamble, sizeof(preamble), size, startIdx);
+ if (errChk == 0) return 0;
+ idx = *startIdx + 9;
+ for (i=0; i<10;i++){ //loop through 10 sets of 5 bits (50-10p = 40 bits)
+ parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5);
+ //check even parity
+ if (parityTest(parityBits, 5, 0) == 0){
+ //parity failed try next bit (in the case of 1111111111) but last 9 = preamble
+ startIdx++;
+ errChk = 0;
+ break;
+ }
+ for (uint8_t ii=0; ii<4; ii++){
+ lo = (lo << 1LL) | (BitStream[(i*5)+ii+idx]);
+ }
+ }
+ if (errChk != 0) return lo;
+ //skip last 5 bit parity test for simplicity.
+ // *size = 64;
+ }
+ return 0;
}
//by marshmellow
for (i = iii; i < *size; ++i) {
if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
lastBit+=*clk;
- //BitStream[bitnum] = *invert;
- //bitnum++;
midBit=0;
} else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
//low found and we are expecting a bar
lastBit+=*clk;
- //BitStream[bitnum] = 1- *invert;
- //bitnum++;
midBit=0;
} else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
//mid bar?
midBit=1;
- //BitStream[bitnum]= 1- *invert;
- //bitnum++;
} else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
//mid bar?
midBit=1;
- //BitStream[bitnum]= *invert;
- //bitnum++;
} else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){
//no mid bar found
midBit=1;
- //BitStream[bitnum]= BitStream[bitnum-1];
- //bitnum++;
} else {
//mid value found or no bar supposed to be here
//should have hit a high or low based on clock!!
//debug
//PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
- //if (bitnum > 0){
- // BitStream[bitnum]=77;
- // bitnum++;
- //}
errCnt++;
lastBit+=*clk;//skip over until hit too many errors
if (errCnt > ((*size/1000))){ //allow 1 error for every 1000 samples else start over
errCnt=0;
- // bitnum=0;//start over
break;
}
}
size = aggregate_bits(dest, size, rfLen, 192, invert, fchigh, fclow);
return size;
}
+
// 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)
{
+ if (justNoise(dest, *size)) return -1;
- size_t idx=0, size2=*size, startIdx=0;
- // FSK demodulator
-
- *size = fskdemod(dest, size2,50,0,10,8);
-
- // final loop, go over previously decoded manchester data and decode into usable tag ID
- // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
- uint8_t frame_marker_mask[] = {1,1,1,0,0,0};
- int numshifts = 0;
- idx = 0;
- //one scan
- while( idx + sizeof(frame_marker_mask) < *size) {
- // search for a start of frame marker
- if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
- { // frame marker found
- startIdx=idx;
- idx+=sizeof(frame_marker_mask);
- while(dest[idx] != dest[idx+1] && idx < *size-2)
- {
- // Keep going until next frame marker (or error)
- // Shift in a bit. Start by shifting high registers
- *hi2 = (*hi2<<1)|(*hi>>31);
- *hi = (*hi<<1)|(*lo>>31);
- //Then, shift in a 0 or one into low
- if (dest[idx] && !dest[idx+1]) // 1 0
- *lo=(*lo<<1)|0;
- else // 0 1
- *lo=(*lo<<1)|1;
- numshifts++;
- idx += 2;
- }
- // Hopefully, we read a tag and hit upon the next frame marker
- if(idx + sizeof(frame_marker_mask) < *size)
- {
- if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
- {
- //good return
- *size=idx-startIdx;
- return startIdx;
- }
- }
- // reset
- *hi2 = *hi = *lo = 0;
- numshifts = 0;
- }else {
- idx++;
- }
- }
- return -1;
+ size_t numStart=0, size2=*size, startIdx=0;
+ // FSK demodulator
+ *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
+ if (*size < 96) return -2;
+ // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
+ uint8_t preamble[] = {0,0,0,1,1,1,0,1};
+ // find bitstring in array
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+ if (errChk == 0) return -3; //preamble not found
+
+ numStart = startIdx + sizeof(preamble);
+ // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
+ for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
+ if (dest[idx] == dest[idx+1]){
+ return -4; //not manchester data
+ }
+ *hi2 = (*hi2<<1)|(*hi>>31);
+ *hi = (*hi<<1)|(*lo>>31);
+ //Then, shift in a 0 or one into low
+ if (dest[idx] && !dest[idx+1]) // 1 0
+ *lo=(*lo<<1)|1;
+ else // 0 1
+ *lo=(*lo<<1)|0;
+ }
+ return (int)startIdx;
}
// loop to get raw paradox waveform then FSK demodulate the TAG ID from it
-size_t ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
+int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
{
-
- size_t idx=0, size2=*size;
+ if (justNoise(dest, *size)) return -1;
+
+ size_t numStart=0, size2=*size, startIdx=0;
// FSK demodulator
-
- *size = fskdemod(dest, size2,50,1,10,8);
-
- // final loop, go over previously decoded manchester data and decode into usable tag ID
- // 00001111 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
- uint8_t frame_marker_mask[] = {0,0,0,0,1,1,1,1};
- uint16_t numshifts = 0;
- idx = 0;
- //one scan
- while( idx + sizeof(frame_marker_mask) < *size) {
- // search for a start of frame marker
- if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
- { // frame marker found
- size2=idx;
- idx+=sizeof(frame_marker_mask);
- while(dest[idx] != dest[idx+1] && idx < *size-2)
- {
- // Keep going until next frame marker (or error)
- // Shift in a bit. Start by shifting high registers
- *hi2 = (*hi2<<1)|(*hi>>31);
- *hi = (*hi<<1)|(*lo>>31);
- //Then, shift in a 0 or one into low
- if (dest[idx] && !dest[idx+1]) // 1 0
- *lo=(*lo<<1)|1;
- else // 0 1
- *lo=(*lo<<1)|0;
- numshifts++;
- idx += 2;
- }
- // Hopefully, we read a tag and hit upon the next frame marker and got enough bits
- if(idx + sizeof(frame_marker_mask) < *size && numshifts > 40)
- {
- if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
- {
- //good return - return start grid position and bits found
- *size = ((numshifts*2)+8);
- return size2;
- }
- }
- // reset
- *hi2 = *hi = *lo = 0;
- numshifts = 0;
- }else {
- idx++;
- }
+ *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
+ if (*size < 96) return -2;
+
+ // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
+ uint8_t preamble[] = {0,0,0,0,1,1,1,1};
+
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+ if (errChk == 0) return -3; //preamble not found
+
+ numStart = startIdx + sizeof(preamble);
+ // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
+ for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
+ if (dest[idx] == dest[idx+1])
+ return -4; //not manchester data
+ *hi2 = (*hi2<<1)|(*hi>>31);
+ *hi = (*hi<<1)|(*lo>>31);
+ //Then, shift in a 0 or one into low
+ if (dest[idx] && !dest[idx+1]) // 1 0
+ *lo=(*lo<<1)|1;
+ else // 0 1
+ *lo=(*lo<<1)|0;
}
- return 0;
+ return (int)startIdx;
}
uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
int IOdemodFSK(uint8_t *dest, size_t size)
{
- static const uint8_t THRESHOLD = 129;
- uint32_t idx=0;
+ if (justNoise(dest, size)) return -1;
//make sure buffer has data
- if (size < 66) return -1;
- //test samples are not just noise
- uint8_t justNoise = 1;
- for(idx=0;idx< size && justNoise ;idx++){
- justNoise = dest[idx] < THRESHOLD;
- }
- if(justNoise) return 0;
-
+ if (size < 66*64) return -2;
// FSK demodulator
- size = fskdemod(dest, size, 64, 1, 10, 8); // RF/64 and invert
- if (size < 65) return -1; //did we get a good demod?
+ size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64
+ if (size < 65) return -3; //did we get a good demod?
//Index map
//0 10 20 30 40 50 60
//| | | | | | |
//
//XSF(version)facility:codeone+codetwo
//Handle the data
- uint8_t mask[] = {0,0,0,0,0,0,0,0,0,1};
- for( idx=0; idx < (size - 65); idx++) {
- if ( memcmp(dest + idx, mask, sizeof(mask))==0) {
- //frame marker found
- if (!dest[idx+8] && dest[idx+17]==1 && dest[idx+26]==1 && dest[idx+35]==1 && dest[idx+44]==1 && dest[idx+53]==1){
- //confirmed proper separator bits found
- //return start position
- return (int) idx;
- }
- }
+ size_t startIdx = 0;
+ uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1};
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx);
+ if (errChk == 0) return -4; //preamble not found
+
+ if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){
+ //confirmed proper separator bits found
+ //return start position
+ return (int) startIdx;
}
- return 0;
-}
-
-// by marshmellow
-// pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
-// returns 1 if passed
-uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
-{
- uint8_t ans = 0;
- for (uint8_t i = 0; i < bitLen; i++){
- ans ^= ((bits >> i) & 1);
- }
- //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
- return (ans == pType);
+ return -5;
}
// by marshmellow
// by marshmellow
// FSK Demod then try to locate an AWID ID
-int AWIDdemodFSK(uint8_t *dest, size_t size)
+int AWIDdemodFSK(uint8_t *dest, size_t *size)
{
- static const uint8_t THRESHOLD = 123;
- uint32_t idx=0, idx2=0;
- //make sure buffer has data
- if (size < 96*50) return -1;
- //test samples are not just noise
- uint8_t justNoise = 1;
- for(idx=0; idx < size && justNoise ;idx++){
- justNoise = dest[idx] < THRESHOLD;
- }
- if(justNoise) return -2;
+ //make sure buffer has enough data
+ if (*size < 96*50) return -1;
+
+ if (justNoise(dest, *size)) return -2;
// FSK demodulator
- size = fskdemod(dest, size, 50, 1, 10, 8); // RF/64 and invert
- if (size < 96) return -3; //did we get a good demod?
-
- uint8_t mask[] = {0,0,0,0,0,0,0,1};
- for( idx=0; idx < (size - 96); idx++) {
- if ( memcmp(dest + idx, mask, sizeof(mask))==0) {
- // frame marker found
- //return ID start index
- if (idx2 == 0) idx2=idx;
- else if(idx-idx2==96) return idx2;
- else return -5;
-
- // should always get 96 bits if it is awid
- }
- }
- //never found mask
- return -4;
+ *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
+ if (*size < 96) return -3; //did we get a good demod?
+
+ uint8_t preamble[] = {0,0,0,0,0,0,0,1};
+ size_t startIdx = 0;
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+ if (errChk == 0) return -4; //preamble not found
+ if (*size != 96) return -5;
+ return (int)startIdx;
}
// by marshmellow
// FSK Demod then try to locate an Farpointe Data (pyramid) ID
-int PyramiddemodFSK(uint8_t *dest, size_t size)
+int PyramiddemodFSK(uint8_t *dest, size_t *size)
{
- static const uint8_t THRESHOLD = 123;
- uint32_t idx=0, idx2=0;
- // size_t size2 = size;
//make sure buffer has data
- if (size < 128*50) return -5;
+ if (*size < 128*50) return -5;
+
//test samples are not just noise
- uint8_t justNoise = 1;
- for(idx=0; idx < size && justNoise ;idx++){
- justNoise = dest[idx] < THRESHOLD;
- }
- if(justNoise) return -1;
+ if (justNoise(dest, *size)) return -1;
// FSK demodulator
- size = fskdemod(dest, size, 50, 1, 10, 8); // RF/64 and invert
- if (size < 128) return -2; //did we get a good demod?
-
- uint8_t mask[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
- for( idx=0; idx < (size - 128); idx++) {
- if ( memcmp(dest + idx, mask, sizeof(mask))==0) {
- // frame marker found
- if (idx2==0) idx2=idx;
- else if (idx-idx2==128) return idx2;
- else return -3;
- }
- }
- //never found mask
- return -4;
+ *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
+ if (*size < 128) return -2; //did we get a good demod?
+
+ uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
+ size_t startIdx = 0;
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+ if (errChk == 0) return -4; //preamble not found
+ if (*size != 128) return -3;
+ return (int)startIdx;
}
-
// by marshmellow
// not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
// maybe somehow adjust peak trimming value based on samples to fix?
return clk[best];
}
-
//by marshmellow
//detect psk clock by reading #peaks vs no peaks(or errors)
int DetectpskNRZClock(uint8_t dest[], size_t size, int clock)
return clk[best];
}
-//by marshmellow (attempt to get rid of high immediately after a low)
+// by marshmellow (attempt to get rid of high immediately after a low)
void pskCleanWave(uint8_t *BitStream, size_t size)
{
int i;
return;
}
+// by marshmellow
+// convert psk1 demod to psk2 demod
+// only transition waves are 1s
+void psk1TOpsk2(uint8_t *BitStream, size_t size)
+{
+ size_t i=1;
+ uint8_t lastBit=BitStream[0];
+ for (; i<size; i++){
+ if (lastBit!=BitStream[i]){
+ lastBit=BitStream[i];
+ BitStream[i]=1;
+ } else {
+ BitStream[i]=0;
+ }
+ }
+ 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
+// 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)
return 1;
}
-
-//by marshmellow - demodulate PSK1 wave or NRZ wave (both similar enough)
-//peaks switch bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
+// 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 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;
return errCnt;
}
-
//by marshmellow
-//countFC is to detect the field clock and bit clock rates.
-//for fsk or ask not psk or nrz
-uint32_t countFC(uint8_t *BitStream, size_t size)
+//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)
{
- // get high/low thresholds
- int high, low;
- getHiLo(BitStream,10, &high, &low, 100, 100);
- // get zero crossing
- uint8_t zeroC = (high-low)/2+low;
- uint8_t clk[]={8,16,32,40,50,64,100,128};
- 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 rfLens[] = {0,0,0,0,0,0,0,0,0,0,0};
- // uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0};
- uint8_t fcLensFnd = 0;
+ 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 lastBit=0;
- uint8_t curBit=0;
uint8_t lastFCcnt=0;
- uint32_t errCnt=0;
uint32_t fcCounter = 0;
- uint32_t rfCounter = 0;
+ uint16_t rfCounter = 0;
uint8_t firstBitFnd = 0;
- int i;
-
+ 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; i++)
- if (BitStream[i]>=zeroC && BitStream[i-1]<zeroC)
+ for (i = 1; i < size-1; i++)
+ if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
break;
- for (; i < size; i++){
- curBit = BitStream[i];
- lastBit = BitStream[i-1];
- if (lastBit<zeroC && curBit >= zeroC){
- // new up transition
+ for (; i < size-1; i++){
+ if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]){
+ // new peak
fcCounter++;
rfCounter++;
- if (fcCounter > 3 && fcCounter < 256){
- //we've counted enough that it could be a valid field clock
-
- //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++;
+ // 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<10; ii++){
- if (rfLens[ii]==rfCounter){
- //rfCnts[ii]++;
- rfCounter=0;
- break;
- }
+ //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<10){
- //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
- //rfCnts[rfLensFnd]++;
- rfLens[rfLensFnd++]=rfCounter;
- }
- } else {
- //PrintAndLog("DEBUG i: %d",i);
- firstBitFnd++;
}
- rfCounter=0;
- lastFCcnt=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 (rfCounter>0 && rfLensFnd<15){
+ //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
+ rfCnts[rfLensFnd]++;
+ rfLens[rfLensFnd++]=rfCounter;
}
+ } else {
+ firstBitFnd++;
}
- if (fcCounter>0 && fcLensFnd<10){
- //add new fc length
- //PrintAndLog("FCCntr %d",fcCounter);
- fcCnts[fcLensFnd]++;
- fcLens[fcLensFnd++]=fcCounter;
- }
- } else{
- // hmmm this should not happen often - count them
- errCnt++;
+ rfCounter=0;
+ lastFCcnt=fcCounter;
}
- // reset counter
fcCounter=0;
} else {
// count sample
rfCounter++;
}
}
- // if too many errors return errors as negative number (IS THIS NEEDED?)
- if (errCnt>100) return -1*errCnt;
-
- uint8_t maxCnt1=0, best1=9, best2=9, best3=9, rfHighest=10, rfHighest2=10, rfHighest3=10;
+ uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
- // go through fclens and find which ones are bigest 2
- for (i=0; i<10; i++){
- // PrintAndLog("DEBUG: FC %d, Cnt %d, Errs %d, RF %d",fcLens[i],fcCnts[i],errCnt,rfLens[i]);
-
- // 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;
- }
+ 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 (rfLens[i]>rfLens[rfHighest]){
+ if (rfCnts[i]>rfCnts[rfHighest]){
rfHighest3=rfHighest2;
rfHighest2=rfHighest;
rfHighest=i;
- } else if(rfLens[i]>rfLens[rfHighest2]){
+ } else if(rfCnts[i]>rfCnts[rfHighest2]){
rfHighest3=rfHighest2;
rfHighest2=i;
- } else if(rfLens[i]>rfLens[rfHighest3]){
+ } else if(rfCnts[i]>rfCnts[rfHighest3]){
rfHighest3=i;
}
- }
-
- // set allowed clock remainder tolerance to be 1 large field clock length
- // we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
- int tol1 = (fcLens[best1]>fcLens[best2]) ? fcLens[best1] : fcLens[best2];
+ }
+ // 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
+ // 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 (ii<0) ii=7; // oops we went too far
+ if (ii<0) return 0; // oops we went too far
- // TODO: take top 3 answers and compare to known Field clocks to get top 2
+ return clk[ii];
+}
- uint32_t fcs=0;
- // PrintAndLog("DEBUG: Best %d best2 %d best3 %d, clk %d, clk2 %d",fcLens[best1],fcLens[best2],fcLens[best3],clk[i],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]){
- fcs = (((uint32_t)clk[ii])<<16) | (((uint32_t)fcLens[best1])<<8) | ((fcLens[best2]));
- } else {
- fcs = (((uint32_t)clk[ii])<<16) | (((uint32_t)fcLens[best2])<<8) | ((fcLens[best1]));
+ 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