Merge pull request #146 from dnet/patch-1

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 7d40d22e5aa44551835ae4ada1f69947f132e488..a3a7a50087727fc1f85a7a5a8df881537e21e04e 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -526,7 +526,7 @@ int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, ui
        return (int)startIdx;
 }
 
-uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
+uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
 {
        uint32_t num = 0;
        for(int i = 0 ; i < numbits ; i++)
@@ -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 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;
@@ -579,9 +590,13 @@ 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;
        }
@@ -590,6 +605,21 @@ 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)