X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/ec75f5c10a91211e50b74af181b827fc93a6dcd5..refs/heads/graphwork:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index 8f1a3764..88a250d8 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -12,6 +12,18 @@ #include #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) @@ -29,59 +41,82 @@ int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi 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 @@ -336,30 +371,20 @@ int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert) 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 @@ -367,16 +392,11 @@ int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert) //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; } } @@ -552,114 +572,69 @@ int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t 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) @@ -675,20 +650,12 @@ 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 //| | | | | | | @@ -698,31 +665,17 @@ int IOdemodFSK(uint8_t *dest, size_t size) // //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 @@ -750,73 +703,47 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p // 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? @@ -885,7 +812,6 @@ int DetectASKClock(uint8_t dest[], size_t size, int clock) 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) @@ -963,7 +889,7 @@ 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; @@ -999,9 +925,26 @@ void pskCleanWave(uint8_t *BitStream, size_t size) 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=zeroC && BitStream[i-1] BitStream[i-1] && BitStream[i]>=BitStream[i+1]) break; - for (; i < size; i++){ - curBit = BitStream[i]; - lastBit = BitStream[i-1]; - if (lastBit= 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 ((fcCounterlastFCcnt)){ - //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 ((fcCounterlastFCcnt)){ + //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 @@ -1297,46 +1206,30 @@ uint32_t countFC(uint8_t *BitStream, size_t size) 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){ @@ -1348,19 +1241,90 @@ uint32_t countFC(uint8_t *BitStream, size_t size) } } - 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; }