]> git.zerfleddert.de Git - proxmark3-svn/blobdiff - common/lfdemod.c
ADD: 'LF T55X7 WAKEUP' command. For tags with AOR bit set, send this command...
[proxmark3-svn] / common / lfdemod.c
index 5bbf8a669969ff24b5a46f2ce57c4a0c5930b89a..0f8dd4522c2127e56f493d8206b381a9f029e497 100644 (file)
@@ -112,7 +112,8 @@ uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_
        return 0;
 }
 
-// demodulates strong heavily clipped samples
+//by marshmellow
+//demodulates strong heavily clipped samples
 int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
 {
        size_t bitCnt=0, smplCnt=0, errCnt=0;
@@ -163,52 +164,81 @@ int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int
 }
 
 //by marshmellow
-//takes 3 arguments - clock, invert, maxErr as integers
-//attempts to demodulate ask while decoding manchester
-//prints binary found and saves in graphbuffer for further commands
-int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr)
+void askAmp(uint8_t *BitStream, size_t size)
 {
-       size_t i;
+       for(size_t i = 1; i<size; i++){
+               if (BitStream[i]-BitStream[i-1]>=30) //large jump up
+                       BitStream[i]=127;
+               else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down
+                       BitStream[i]=-127;
+       }
+       return;
+}
+
+//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)
+{
+       if (*size==0) return -1;
        int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
        if (*clk==0 || start < 0) return -3;
-       if (*invert != 1) *invert=0;
+       if (*invert != 1) *invert = 0;
+       if (amp==1) askAmp(BinStream, *size);
+
        uint8_t initLoopMax = 255;
        if (initLoopMax > *size) initLoopMax = *size;
        // Detect high and lows
-       // 25% fuzz in case highs and lows aren't clipped [marshmellow]
+       //25% clip in case highs and lows aren't clipped [marshmellow]
        int high, low;
-       if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) return -2; //just noise
+       if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) 
+               return -2; //just noise
 
+       size_t errCnt = 0;
        // if clean clipped waves detected run alternate demod
        if (DetectCleanAskWave(BinStream, *size, high, low)) {
-               cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
-               return manrawdecode(BinStream, size);   
+               errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
+               if (askType) //askman
+                       return manrawdecode(BinStream, size, 0);        
+               else //askraw
+                       return errCnt;
        }
 
-       // PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
-       int lastBit;  //set first clock check
-       uint16_t bitnum = 0;     //output counter
+       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
-       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
-       uint16_t errCnt = 0, MaxBits = 512;
+       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 = 1024;
        lastBit = start - *clk;
+
        for (i = start; i < *size; ++i) {
-               if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
-                       //high found and we are expecting a bar
-                       lastBit += *clk;
-                       BinStream[bitnum++] = *invert;
-               } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
-                       //low found and we are expecting a bar
+               if (i-lastBit >= *clk-tol){
+                       if (BinStream[i] >= high) {
+                               BinStream[bitnum++] = *invert;
+                       } else if (BinStream[i] <= low) {
+                               BinStream[bitnum++] = *invert ^ 1;
+                       } else if (i-lastBit >= *clk+tol) {
+                               if (bitnum > 0) {
+                                       BinStream[bitnum++]=7;
+                                       errCnt++;                                               
+                               } 
+                       } else { //in tolerance - looking for peak
+                               continue;
+                       }
+                       midBit = 0;
                        lastBit += *clk;
-                       BinStream[bitnum++] = *invert ^ 1;
-               } else if ((i-lastBit)>(*clk+tol)){
-                       //should have hit a high or low based on clock!!
-                       //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) {
-                               BinStream[bitnum++] = 7;
-                               errCnt++;
-                       }               
-                       lastBit += *clk;//skip over error
+               } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){
+                       if (BinStream[i] >= high) {
+                               BinStream[bitnum++] = *invert;
+                       } else if (BinStream[i] <= low) {
+                               BinStream[bitnum++] = *invert ^ 1;
+                       } else if (i-lastBit >= *clk/2+tol) {
+                               BinStream[bitnum] = BinStream[bitnum-1];
+                               bitnum++;
+                       } else { //in tolerance - looking for peak
+                               continue;
+                       }
+                       midBit = 1;
                }
                if (bitnum >= MaxBits) break;
        }
@@ -216,34 +246,18 @@ int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int max
        return errCnt;
 }
 
-//by marshmellow
-//encode binary data into binary manchester 
-int ManchesterEncode(uint8_t *BitStream, size_t size)
-{
-       size_t modIdx=20000, i=0;
-       if (size>modIdx) return -1;
-       for (size_t idx=0; idx < size; idx++){
-               BitStream[idx+modIdx++] = BitStream[idx];
-               BitStream[idx+modIdx++] = BitStream[idx]^1;
-       }
-       for (; i<(size*2); i++){
-               BitStream[i] = BitStream[i+20000];
-       }
-       return i;
-}
-
 //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)
+int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert)
 {
        uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
        size_t i, ii;
        uint16_t bestErr = 1000, bestRun = 0;
-       if (size == 0) return -1;
+       if (*size < 16) return -1;
        //find correct start position [alignment]
        for (ii=0;ii<2;++ii){
-               for (i=ii; i<*size-2; i+=2)
+               for (i=ii; i<*size-3; i+=2)
                        if (BitStream[i]==BitStream[i+1])
                                errCnt++;
 
@@ -254,11 +268,11 @@ int manrawdecode(uint8_t * BitStream, size_t *size)
                errCnt=0;
        }
        //decode
-       for (i=bestRun; i < *size-2; i+=2){
+       for (i=bestRun; i < *size-3; i+=2){
                if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
-                       BitStream[bitnum++]=0;
+                       BitStream[bitnum++]=invert;
                } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
-                       BitStream[bitnum++]=1;
+                       BitStream[bitnum++]=invert^1;
                } else {
                        BitStream[bitnum++]=7;
                }
@@ -268,6 +282,22 @@ int manrawdecode(uint8_t * BitStream, size_t *size)
        return bestErr;
 }
 
+//by marshmellow
+//encode binary data into binary manchester 
+int ManchesterEncode(uint8_t *BitStream, size_t size)
+{
+       size_t modIdx=20000, i=0;
+       if (size>modIdx) return -1;
+       for (size_t idx=0; idx < size; idx++){
+               BitStream[idx+modIdx++] = BitStream[idx];
+               BitStream[idx+modIdx++] = BitStream[idx]^1;
+       }
+       for (; i<(size*2); i++){
+               BitStream[i] = BitStream[i+20000];
+       }
+       return i;
+}
+
 //by marshmellow
 //take 01 or 10 = 1 and 11 or 00 = 0
 //check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
@@ -307,88 +337,7 @@ int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
        return errCnt;
 }
 
-//by marshmellow
-void askAmp(uint8_t *BitStream, size_t size)
-{
-       int shift = 127;
-       int shiftedVal=0;
-       for(size_t i = 1; i<size; i++){
-               if (BitStream[i]-BitStream[i-1]>=30) //large jump up
-                       shift=127;
-               else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down
-                       shift=-127;
-
-               shiftedVal=BitStream[i]+shift;
-
-               if (shiftedVal>255) 
-                       shiftedVal=255;
-               else if (shiftedVal<0) 
-                       shiftedVal=0;
-               BitStream[i-1] = shiftedVal;
-       }
-       return;
-}
-
-//by marshmellow
-//takes 3 arguments - clock, invert and maxErr as integers
-//attempts to demodulate ask only
-int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp)
-{
-       if (*size==0) return -1;
-       int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
-       if (*clk==0 || start < 0) return -1;
-       if (*invert != 1) *invert = 0;
-       if (amp==1) askAmp(BinStream, *size);
-
-       uint8_t initLoopMax = 255;
-       if (initLoopMax > *size) initLoopMax = *size;
-       // Detect high and lows
-       //25% clip in case highs and lows aren't clipped [marshmellow]
-       int high, low;
-       if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) 
-               return -1; //just noise
-
-       // if clean clipped waves detected run alternate demod
-       if (DetectCleanAskWave(BinStream, *size, high, low))
-               return cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
-
-       int lastBit;  //set first clock check - can go negative
-       size_t i, errCnt = 0, bitnum = 0;     //output counter
-       uint8_t midBit = 0;
-       size_t MaxBits = 1024;
-       lastBit = start - *clk;
-
-       for (i = start; i < *size; ++i) {
-               if (i - lastBit == *clk){
-                       if (BinStream[i] >= high) {
-                               BinStream[bitnum++] = *invert;
-                       } else if (BinStream[i] <= low) {
-                               BinStream[bitnum++] = *invert ^ 1;
-                       } else {
-                               if (bitnum > 0) {
-                                       BinStream[bitnum++]=7;
-                                       errCnt++;                                               
-                               } 
-                       }
-                       midBit = 0;
-                       lastBit += *clk;
-               } else if (i-lastBit == (*clk/2) && midBit == 0){
-                       if (BinStream[i] >= high) {
-                               BinStream[bitnum++] = *invert;
-                       } else if (BinStream[i] <= low) {
-                               BinStream[bitnum++] = *invert ^ 1;
-                       } else {
-                               BinStream[bitnum] = BinStream[bitnum-1];
-                               bitnum++;
-                       }
-                       midBit = 1;
-               }
-               if (bitnum >= MaxBits) break;
-       }
-       *size = bitnum;
-       return errCnt;
-}
-
+// by marshmellow
 // demod gProxIIDemod 
 // error returns as -x 
 // success returns start position in BitStream
@@ -420,7 +369,9 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
        if (fclow==0) fclow=8;
        //set the threshold close to 0 (graph) or 128 std to avoid static
        uint8_t threshold_value = 123; 
-
+       size_t preLastSample = 0;
+       size_t LastSample = 0;
+       size_t currSample = 0;
        // sync to first lo-hi transition, and threshold
 
        // Need to threshold first sample
@@ -440,13 +391,22 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
 
                // Check for 0->1 transition
                if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition
-                       if ((idx-last_transition)<(fclow-2)){            //0-5 = garbage noise
+                       preLastSample = LastSample;
+                       LastSample = currSample;
+                       currSample = idx-last_transition;
+                       if (currSample < (fclow-2)){            //0-5 = garbage noise
                                //do nothing with extra garbage
-                       } else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves
+                       } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves
+                               if (LastSample > (fchigh-2) && preLastSample < (fchigh-1)){
+                                       dest[numBits-1]=1;  //correct last 9 wave surrounded by 8 waves
+                               }
                                dest[numBits++]=1;
-                       } else if ((idx-last_transition) > (fchigh+1) && !numBits) { //12 + and first bit = garbage 
+
+                       } else if (currSample > (fchigh+1) && !numBits) { //12 + and first bit = garbage 
                                //do nothing with beginning garbage
-                       } else {                                         //9+ = 10 waves
+                       } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's
+                               dest[numBits++]=1;
+                       } else {                                         //9+ = 10 sample waves
                                dest[numBits++]=0;
                        }
                        last_transition = idx;
@@ -588,6 +548,17 @@ uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
        return num;
 }
 
+//least significant bit first
+uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits)
+{
+       uint32_t num = 0;
+       for(int i = 0 ; i < numbits ; i++)
+       {
+               num = (num << 1) | *(src + (numbits-(i+1)));
+       }
+       return num;
+}
+
 int IOdemodFSK(uint8_t *dest, size_t size)
 {
        if (justNoise(dest, size)) return -1;
@@ -620,7 +591,7 @@ int IOdemodFSK(uint8_t *dest, size_t size)
 
 // by marshmellow
 // takes a array of binary values, start position, length of bits per parity (includes parity bit),
-//   Parity Type (1 for odd 0 for even), and binary Length (length to run) 
+//   Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run) 
 size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen)
 {
        uint32_t parityWd = 0;
@@ -630,9 +601,13 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
                        parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
                        BitStream[j++] = (BitStream[startIdx+word+bit]);
                }
-               j--;
+               j--; // overwrite parity with next data
                // if parity fails then return 0
-               if (parityTest(parityWd, pLen, pType) == 0) return -1;
+               if (pType == 2) { // then marker bit which should be a 1
+                       if (!BitStream[j]) return 0;
+               } else {
+                       if (parityTest(parityWd, pLen, pType) == 0) return 0;                   
+               }
                bitCnt+=(pLen-1);
                parityWd = 0;
        }
@@ -641,6 +616,21 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
        return bitCnt;
 }
 
+// Ask/Biphase Demod then try to locate an ISO 11784/85 ID
+// BitStream must contain previously askrawdemod and biphasedemoded data
+int FDXBdemodBI(uint8_t *dest, size_t *size)
+{
+       //make sure buffer has enough data
+       if (*size < 128) return -1;
+
+       size_t startIdx = 0;
+       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};
+
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -2; //preamble not found
+       return (int)startIdx;
+}
+
 // by marshmellow
 // FSK Demod then try to locate an AWID ID
 int AWIDdemodFSK(uint8_t *dest, size_t *size)
@@ -684,7 +674,8 @@ int PyramiddemodFSK(uint8_t *dest, size_t *size)
        return (int)startIdx;
 }
 
-
+// by marshmellow
+// to detect a wave that has heavily clipped (clean) samples
 uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
 {
        uint16_t allPeaks=1;
@@ -792,7 +783,7 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
 
        //test each valid clock from smallest to greatest to see which lines up
        for(; clkCnt < clkEnd; clkCnt++){
-               if (clk[clkCnt] == 32){
+               if (clk[clkCnt] <= 32){
                        tol=1;
                }else{
                        tol=0;
@@ -1504,3 +1495,30 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
        *size = numBits;
        return errCnt;
 }
+// on successful return 1 otherwise return 0
+int VikingDecode(uint8_t *BitStream, 
+                                       size_t size,
+                                       size_t *startIdx,
+                                       uint8_t *id_bits,
+                                       size_t id_bits_size)
+{
+    //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
+    uint32_t i = 0;
+    uint32_t lastcheckindex = size - (id_bits_size * 2);
+    int found = 0;
+    while (i < lastcheckindex)
+    {
+        if (memcmp(BitStream + i,id_bits,id_bits_size) == 0)
+        {
+            *startIdx = i;
+            found = 1;
+            break;
+        }
+        i++;
+    }
+    return found;
+}
+
+
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