X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/051643995984009593bcb8180ff9f9d570af7df5..547595784facfc9565ca08af18d9bead6bfac31b:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index 306f3626..edebe456 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -95,7 +95,7 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p // by marshmellow // takes a array of binary values, length of bits per parity (includes parity bit), -// Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run) +// Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run) size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType) { uint32_t parityWd = 0; @@ -105,12 +105,16 @@ size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t p parityWd = (parityWd << 1) | BitSource[word+bit]; dest[j++] = (BitSource[word+bit]); } + // if parity fails then return 0 - if (pType == 2) { // then marker bit which should be a 1 - dest[j++]=1; - } else { - dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1; + switch (pType) { + case 3: dest[j++]=0; break; // marker bit which should be a 0 + case 2: dest[j++]=1; break; // marker bit which should be a 1 + default: + dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1; + break; } + bitCnt += pLen; parityWd = 0; } @@ -122,8 +126,7 @@ size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t p uint32_t bytebits_to_byte(uint8_t *src, size_t numbits) { uint32_t num = 0; - for(int i = 0 ; i < numbits ; i++) - { + for(int i = 0 ; i < numbits ; i++) { num = (num << 1) | (*src); src++; } @@ -484,7 +487,7 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow size_t numBits = 0; // 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 with anywhere + // 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 for(idx = 161; idx < size-20; idx++) { // threshold current value