X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/615f21dde29ed68c6b9dbb6c79c2a293751d777a..5ee53a0e75c48de359108f5d21d4b829ed504467:/common/lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 2c650144..71cbfea9 100644
--- 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 (justNoise(dest, *size)) return -2;
+	if (*size < 128) return -1;
 
-	// 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;
 }
 
@@ -1473,3 +1482,30 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
 	*size = numBits;
 	return errCnt;
 }
+// on successful return 1 otherwise return 0
+int VikingDecode(uint8_t *BitStream, 
+					size_t size,
+					size_t *startIdx,
+					uint8_t *id_bits,
+					size_t id_bits_size)
+{
+    //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
+    //  otherwise could be a void with no arguments
+    //set defaults
+    uint32_t i = 0;
+    uint32_t lastcheckindex = size - (id_bits_size * 2);
+    int found = 0;
+    while (i < lastcheckindex)
+    {
+        if (memcmp(BitStream + i,id_bits,id_bits_size) == 0)
+        {
+            *startIdx = i;
+            found = 1;
+            break;
+        }
+        i++;
+    }
+    return found;
+}
+
+