Merge pull request #119 from marshmellow42/pm3+reveng

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index d6c024fab9bfa872d9a210fa9dfb9334453e6aca..7d40df3a31abc88bab1f85400af47f707979b087 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -81,10 +81,9 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
                j--; // overwrite parity with next data
                // if parity fails then return 0
                switch (pType) {
                j--; // overwrite parity with next data
                // if parity fails then return 0
                switch (pType) {

-                       case 3: if (BitStream[j]==1) return 0; break; //should be 0 spacer bit
-                       case 2: if (BitStream[j]==0) return 0; break; //should be 1 spacer bit
-                       default: //test parity
-                               if (parityTest(parityWd, pLen, pType) == 0) return 0; break;
+                       case 3: if (BitStream[j]==1) {return 0;} break; //should be 0 spacer bit
+                       case 2: if (BitStream[j]==0) {return 0;} break; //should be 1 spacer bit
+                       default: if (parityTest(parityWd, pLen, pType) == 0) {return 0;} break; //test parity

                }
                bitCnt+=(pLen-1);
                parityWd = 0;
                }
                bitCnt+=(pLen-1);
                parityWd = 0;


@@ -260,11 +259,14 @@ int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int
 //by marshmellow
 void askAmp(uint8_t *BitStream, size_t size)
 {
 //by marshmellow
 void askAmp(uint8_t *BitStream, size_t size)
 {

+       uint8_t Last = 128;

        for(size_t i = 1; i<size; i++){
                if (BitStream[i]-BitStream[i-1]>=30) //large jump up
        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;
+                       Last = 255;
+               else if(BitStream[i-1]-BitStream[i]>=20) //large jump down
+                       Last = 0;
+
+               BitStream[i-1] = Last;

        }
        return;
 }
        }
        return;
 }


@@ -464,10 +466,10 @@ int gProxII_Demod(uint8_t BitStream[], size_t *size)
                //return start position
                return (int) startIdx;
        }
                //return start position
                return (int) startIdx;
        }

-       return -5;
+       return -5; //spacer bits not found - not a valid gproxII

 }
 
 }
 

-//translate wave to 11111100000 (1 for each short wave 0 for each long wave)
+//translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])

 size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
 {
        size_t last_transition = 0;
 size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
 {
        size_t last_transition = 0;


@@ -491,6 +493,7 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
        // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
        // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
        // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
        // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
        // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
        // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10

+       //  (could also be fc/5 && fc/7 for fsk1 = 4-9)

        for(idx = 161; idx < size-20; idx++) {
                // threshold current value
 
        for(idx = 161; idx < size-20; idx++) {
                // threshold current value
 


@@ -498,23 +501,24 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
                else dest[idx] = 1;
 
                // Check for 0->1 transition
                else dest[idx] = 1;
 
                // Check for 0->1 transition

-               if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition
+               if (dest[idx-1] < dest[idx]) {

                        preLastSample = LastSample;
                        LastSample = currSample;
                        currSample = idx-last_transition;
                        preLastSample = LastSample;
                        LastSample = currSample;
                        currSample = idx-last_transition;

-                       if (currSample < (fclow-2)){            //0-5 = garbage noise (or 0-3)
+                       if (currSample < (fclow-2)) {                   //0-5 = garbage noise (or 0-3)

                                //do nothing with extra garbage
                                //do nothing with extra garbage

-                       } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves  or 3-6 = 5
+                       } else if (currSample < (fchigh-1)) {           //6-8 = 8 sample waves  (or 3-6 = 5)
+                               //correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)

                                if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample     == 0 )){
                                if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample     == 0 )){

-                                       dest[numBits-1]=1;  //correct previous 9 wave surrounded by 8 waves
+                                       dest[numBits-1]=1;

                                }
                                dest[numBits++]=1;
 
                                }
                                dest[numBits++]=1;
 

-                       } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = garbage 
+                       } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = unusable garbage 

                                //do nothing with beginning garbage
                                //do nothing with beginning garbage

-                       } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's
+                       } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's (or 4 then a 6 should be two 5's)

                                dest[numBits++]=1;
                                dest[numBits++]=1;

-                       } else {                                         //9+ = 10 sample waves
+                       } else {                                        //9+ = 10 sample waves (or 6+ = 7)

                                dest[numBits++]=0;
                        }
                        last_transition = idx;
                                dest[numBits++]=0;
                        }
                        last_transition = idx;


@@ -524,6 +528,7 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
 }
 
 //translate 11111100000 to 10
 }
 
 //translate 11111100000 to 10

+//rfLen = clock, fchigh = larger field clock, fclow = smaller field clock

 size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
                uint8_t invert, uint8_t fchigh, uint8_t fclow)
 {
 size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
                uint8_t invert, uint8_t fchigh, uint8_t fclow)
 {


@@ -533,8 +538,9 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
        uint32_t n=1;
        for( idx=1; idx < size; idx++) {
                n++;
        uint32_t n=1;
        for( idx=1; idx < size; idx++) {
                n++;

-               if (dest[idx]==lastval) continue; 
+               if (dest[idx]==lastval) continue; //skip until we hit a transition

                
                

+               //find out how many bits (n) we collected

                //if lastval was 1, we have a 1->0 crossing
                if (dest[idx-1]==1) {
                        n = (n * fclow + rfLen/2) / rfLen;
                //if lastval was 1, we have a 1->0 crossing
                if (dest[idx-1]==1) {
                        n = (n * fclow + rfLen/2) / rfLen;


@@ -543,6 +549,7 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
                }
                if (n == 0) n = 1;
 
                }
                if (n == 0) n = 1;
 

+               //add to our destination the bits we collected          

                memset(dest+numBits, dest[idx-1]^invert , n);
                numBits += n;
                n=0;
                memset(dest+numBits, dest[idx-1]^invert , n);
                numBits += n;
                n=0;


@@ -1495,8 +1502,8 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
        numBits += (firstFullWave / *clock);
        //set start of wave as clock align
        lastClkBit = firstFullWave;
        numBits += (firstFullWave / *clock);
        //set start of wave as clock align
        lastClkBit = firstFullWave;

-       //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);  
-       //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit);
+       if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u",firstFullWave,fullWaveLen);  
+       if (g_debugMode==2) prnt("DEBUG: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);

        waveStart = 0;
        dest[numBits++] = curPhase; //set first read bit
        for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
        waveStart = 0;
        dest[numBits++] = curPhase; //set first read bit
        for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){


@@ -1679,7 +1686,7 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
        i=0;
        // warning - overwriting buffer given with raw wave data with ST removed...
        while ( dataloc < bufsize-(clk/2) ) {
        i=0;
        // warning - overwriting buffer given with raw wave data with ST removed...
        while ( dataloc < bufsize-(clk/2) ) {

-               //compensate for long high at end of ST not being high... (we cut out the high part)
+               //compensate for long high at end of ST not being high due to signal loss... (and we cut out the start of wave high part)

                if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+3]<high && buffer[dataloc+3]>low) {
                        for(i=0; i < clk/2-tol; ++i) {
                                buffer[dataloc+i] = high+5;
                if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+3]<high && buffer[dataloc+3]>low) {
                        for(i=0; i < clk/2-tol; ++i) {
                                buffer[dataloc+i] = high+5;


@@ -1694,7 +1701,7 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
                        }
                }
                newloc += i;
                        }
                }
                newloc += i;

-               //skip next ST
+               //skip next ST  -  we just assume it will be there from now on...

                dataloc += clk*4;
        }
        *size = newloc;
                dataloc += clk*4;
        }
        *size = newloc;