a couple em4x05 fixes.

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 8324c440f4c19f918159215ff6dc94b397596f80..f9f2d1f1ec3f782b34a7df1c662a54a8c7186041 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -148,6 +148,9 @@ uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits)
 //search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
 uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx)
 {
+       // Sanity check.  If preamble length is bigger than bitstream length.
+       if ( *size <= pLen ) return 0;
+
        uint8_t foundCnt=0;
        for (int idx=0; idx < *size - pLen; idx++){
                if (memcmp(BitStream+idx, preamble, pLen) == 0){
@@ -1372,10 +1375,10 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
        uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
        uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
        uint8_t fcLensFnd = 0;
-       uint8_t lastFCcnt=0;
+       uint8_t lastFCcnt = 0;
        uint8_t fcCounter = 0;
        size_t i;
-       if (size == 0) return 0;
+       if (size < 180) return 0;
 
        // prime i to first up transition
        for (i = 160; i < size-20; i++)