ADD: using @holiman's "ubs_poll_validate_length() function in some device-side...

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 2c65014409eebcb09ca22ea6a85d79f9649b179f..94e08ffa7563ad3569f2473057b476bf041db6cb 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -537,6 +537,17 @@ 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;
@@ -569,7 +580,7 @@ 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 for just drop it), 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;
@@ -581,7 +592,9 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
                }
                j--;
                // if parity fails then return 0
+               if (pType != 2) {
                if (parityTest(parityWd, pLen, pType) == 0) return -1;
+               }
                bitCnt+=(pLen-1);
                parityWd = 0;
        }
@@ -589,23 +602,19 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
        //return ID start index and size
        return bitCnt;
 }
+
 // Ask/Biphase Demod then try to locate an ISO 11784/85 ID
-int ISO11784demodBI(uint8_t *dest, size_t *size)
+// 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*50) return -1;
+       if (*size < 128) return -1;
 
-       if (justNoise(dest, *size)) return -2;
-
-       // FSK demodulator
-       *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[] = {0,0,0,0,0,0,0,0,0,0,1};
        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 -4; //preamble not found
-       if (*size != 128) return -5;
+       if (errChk == 0) return -2; //preamble not found
        return (int)startIdx;
 }