FIX: coverity scan error CID 121781, unused value. error 0x88 will be overritten...

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index c35ce561881757cc4b3d15c7114c3187f86acf0d..4cf22d8667359942c30980e8fa62f14699d204d1 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -218,11 +218,12 @@ int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int
                        smplCnt++;
                } else { //transition
                        if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){
                        smplCnt++;
                } else { //transition
                        if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){

+

                                if (smplCnt > clk-(clk/4)-1) { //full clock
                                if (smplCnt > clk-(clk/4)-1) { //full clock

-                                       if (smplCnt > clk + (clk/4)+1) { //too many samples
+                                       if (smplCnt > clk + (clk/4)+2) { //too many samples

                                                errCnt++;
                                                if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
                                                errCnt++;
                                                if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);

-                                               BinStream[bitCnt++]=7;
+                                               BinStream[bitCnt++] = 7;

                                        } else if (waveHigh) {
                                                BinStream[bitCnt++] = invert;
                                                BinStream[bitCnt++] = invert;
                                        } else if (waveHigh) {
                                                BinStream[bitCnt++] = invert;
                                                BinStream[bitCnt++] = invert;


@@ -280,7 +281,7 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr
        if (*clk==0 || start < 0) return -3;
        if (*invert != 1) *invert = 0;
        if (amp==1) askAmp(BinStream, *size);
        if (*clk==0 || start < 0) return -3;
        if (*invert != 1) *invert = 0;
        if (amp==1) askAmp(BinStream, *size);

-       if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d", *clk, start);
+       if (g_debugMode==2) prnt("DEBUG ASK: size %d, clk %d, beststart %d", *size, *clk, start);

 
        uint8_t initLoopMax = 255;
        if (initLoopMax > *size) initLoopMax = *size;
 
        uint8_t initLoopMax = 255;
        if (initLoopMax > *size) initLoopMax = *size;


@@ -297,8 +298,8 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr
                errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
                if (askType) //askman
                        return manrawdecode(BinStream, size, 0);        
                errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
                if (askType) //askman
                        return manrawdecode(BinStream, size, 0);        

-               else //askraw
-                       return errCnt;
+               //askraw
+               return errCnt;

        }
        if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod");
 
        }
        if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod");
 


@@ -345,38 +346,36 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr
        *size = bitnum;
        return errCnt;
 }
        *size = bitnum;
        return errCnt;
 }

-

 //by marshmellow
 //take 10 and 01 and manchester decode
 //run through 2 times and take least errCnt
 //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, uint8_t invert)
-{
-       uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
-       size_t i, ii;
+int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert){
+       uint16_t bitnum = 0, MaxBits = 512, errCnt = 0;
+       size_t i, k;

        uint16_t bestErr = 1000, bestRun = 0;
        if (*size < 16) return -1;
        //find correct start position [alignment]
        uint16_t bestErr = 1000, bestRun = 0;
        if (*size < 16) return -1;
        //find correct start position [alignment]

-       for (ii=0;ii<2;++ii){
-               for (i=ii; i<*size-3; i+=2)
-                       if (BitStream[i]==BitStream[i+1])
+       for (k=0; k < 2; ++k){
+               for (i=k; i<*size-3; i += 2)
+                       if (BitStream[i] == BitStream[i+1])

                                errCnt++;
 
                                errCnt++;
 

-               if (bestErr>errCnt){
-                       bestErr=errCnt;
-                       bestRun=ii;
+               if (bestErr > errCnt){
+                       bestErr = errCnt;
+                       bestRun = k;

                }
                errCnt=0;
        }
        //decode
                }
                errCnt=0;
        }
        //decode

-       for (i=bestRun; i < *size-3; i+=2){
-               if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
-                       BitStream[bitnum++]=invert;
-               } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
-                       BitStream[bitnum++]=invert^1;
+       for (i=bestRun; i < *size-3; i += 2){
+               if (BitStream[i] == 1 && (BitStream[i+1] == 0)){
+                       BitStream[bitnum++] = invert;
+               } else if ((BitStream[i] == 0) && BitStream[i+1] == 1){
+                       BitStream[bitnum++] = invert^1;

                } else {
                } else {

-                       BitStream[bitnum++]=7;
+                       BitStream[bitnum++] = 7;

                }
                }

-               if(bitnum>MaxBits) break;
+               if (bitnum>MaxBits) break;

        }
        *size=bitnum;
        return bestErr;
        }
        *size=bitnum;
        return bestErr;


@@ -602,10 +601,11 @@ int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32
                *hi2 = (*hi2<<1)|(*hi>>31);
                *hi = (*hi<<1)|(*lo>>31);
                //Then, shift in a 0 or one into low
                *hi2 = (*hi2<<1)|(*hi>>31);
                *hi = (*hi<<1)|(*lo>>31);
                //Then, shift in a 0 or one into low

+               *lo <<= 1;

                if (dest[idx] && !dest[idx+1])  // 1 0
                if (dest[idx] && !dest[idx+1])  // 1 0

-                       *lo=(*lo<<1)|1;
+                       *lo |= 1;

                else // 0 1
                else // 0 1

-                       *lo=(*lo<<1)|0;
+                       *lo |= 0;

        }
        return (int)startIdx;
 }
        }
        return (int)startIdx;
 }


@@ -822,6 +822,19 @@ int NedapDemod(uint8_t *dest, size_t *size) {
        return (int) startIdx;
 }
 
        return (int) startIdx;
 }
 

+// Find IDTEC PSK1, RF  Preamble == 0x4944544B, Demodsize 64bits
+// by iceman
+int IdteckDemodPSK(uint8_t *dest, size_t *size) {
+       //make sure buffer has data
+       if (*size < 64*2) return -1;    
+       size_t startIdx = 0;
+       uint8_t preamble[] = {0,1,0,0,1,0,0,1,0,1,0,0,0,1,0,0,0,1,0,1,0,1,0,0,0,1,0,0,1,0,1,1};
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -2; //preamble not found
+       if (*size != 64) return -3; // wrong demoded 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)
 // 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)


@@ -926,24 +939,28 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
        if (clockFnd>0) {
                clkCnt = clockFnd;
                clkEnd = clockFnd+1;
        if (clockFnd>0) {
                clkCnt = clockFnd;
                clkEnd = clockFnd+1;

+       } else {
+               clkCnt=1;

        }
        }

-       else clkCnt=1;

 
        //test each valid clock from smallest to greatest to see which lines up
 
        //test each valid clock from smallest to greatest to see which lines up

-       for(; clkCnt < clkEnd; clkCnt++){
-               if (clk[clkCnt] <= 32){
+       for(; clkCnt < clkEnd; clkCnt++) {
+               if (clk[clkCnt] <= 32) {

                        tol=1;
                        tol=1;

-               }else{
+               } else {

                        tol=0;
                }
                //if no errors allowed - keep start within the first clock
                        tol=0;
                }
                //if no errors allowed - keep start within the first clock

-               if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) loopCnt=clk[clkCnt]*2;
-               bestErr[clkCnt]=1000;
+               if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) 
+                       loopCnt = clk[clkCnt] * 2;
+
+               bestErr[clkCnt] = 1000;
+

                //try lining up the peaks by moving starting point (try first few clocks)
                for (ii=0; ii < loopCnt; ii++){
                        if (dest[ii] < peak && dest[ii] > low) continue;
 
                //try lining up the peaks by moving starting point (try first few clocks)
                for (ii=0; ii < loopCnt; ii++){
                        if (dest[ii] < peak && dest[ii] > low) continue;
 

-                       errCnt=0;
+                       errCnt = 0;

                        // now that we have the first one lined up test rest of wave array
                        loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1;
                        for (i=0; i < loopEnd; ++i){
                        // now that we have the first one lined up test rest of wave array
                        loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1;
                        for (i=0; i < loopEnd; ++i){


@@ -957,29 +974,29 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
                        }
                        //if we found no errors then we can stop here and a low clock (common clocks)
                        //  this is correct one - return this clock
                        }
                        //if we found no errors then we can stop here and a low clock (common clocks)
                        //  this is correct one - return this clock

-                       if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d",clk[clkCnt],errCnt,ii,i);
-                       if(errCnt==0 && clkCnt<7) { 
+                       if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d", clk[clkCnt], errCnt, ii, i);
+                       if (errCnt==0 && clkCnt<7) { 

                                if (!clockFnd) *clock = clk[clkCnt];
                                return ii;
                        }
                        //if we found errors see if it is lowest so far and save it as best run
                                if (!clockFnd) *clock = clk[clkCnt];
                                return ii;
                        }
                        //if we found errors see if it is lowest so far and save it as best run

-                       if(errCnt<bestErr[clkCnt]){
-                               bestErr[clkCnt]=errCnt;
-                               bestStart[clkCnt]=ii;
+                       if (errCnt < bestErr[clkCnt]) {
+                               bestErr[clkCnt] = errCnt;
+                               bestStart[clkCnt] = ii;

                        }
                }
        }
                        }
                }
        }

-       uint8_t iii;
-       uint8_t best=0;
-       for (iii=1; iii<clkEnd; ++iii){
-               if (bestErr[iii] < bestErr[best]){
-                       if (bestErr[iii] == 0) bestErr[iii]=1;
+       uint8_t k;
+       uint8_t best = 0;
+       for (k=1; k < clkEnd; ++k){
+               if (bestErr[k] < bestErr[best]){
+                       if (bestErr[k] == 0) bestErr[k]=1;

                        // current best bit to error ratio     vs  new bit to error ratio
                        // current best bit to error ratio     vs  new bit to error ratio

-                       if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){
-                               best = iii;
+                       if ( (size/clk[best])/bestErr[best] < (size/clk[k])/bestErr[k] ){
+                               best = k;

                        }
                }
                        }
                }

-               if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, # Errors %d, Current Best Clk %d, bestStart %d",clk[iii],bestErr[iii],clk[best],bestStart[best]);
+               if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, # Errors %d, Current Best Clk %d, bestStart %d", clk[k], bestErr[k], clk[best], bestStart[best]);

        }
        if (!clockFnd) *clock = clk[best];
        return bestStart[best];
        }
        if (!clockFnd) *clock = clk[best];
        return bestStart[best];