From c0afa86f7539fbf40f053cfc13041f5e1f245378 Mon Sep 17 00:00:00 2001
From: iceman1001 <iceman@iuse.se>
Date: Sun, 24 Apr 2016 21:41:45 +0200
Subject: [PATCH] FIX: this commit solves a sneaky bug in 'LF VIKING' commands.
  The getVikingBits dropped the highest byte in the uid while creating the
 datablocks for the clone. ADD:  added some extra message in debugmode when
 looking at viking tags.

---
 client/cmddata.c     |  2 +-
 client/cmdlfviking.c |  4 ++--
 common/lfdemod.c     | 13 +++++++++----
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/client/cmddata.c b/client/cmddata.c
index 55c2d195..2e363054 100644
--- a/client/cmddata.c
+++ b/client/cmddata.c
@@ -660,7 +660,7 @@ int CmdVikingDemod(const char *Cmd)
 	//call lfdemod.c demod for Viking
 	int ans = VikingDemod_AM(DemodBuffer, &size);
 	if (ans < 0) {
-		if (g_debugMode) PrintAndLog("Error Viking_Demod %d", ans);
+		if (g_debugMode) PrintAndLog("Error Viking_Demod %d %s", ans, (ans == -5)?"[chksum error]":"");
 		return 0;
 	}
 	//got a good demod
diff --git a/client/cmdlfviking.c b/client/cmdlfviking.c
index b91aced8..039e4ae6 100644
--- a/client/cmdlfviking.c
+++ b/client/cmdlfviking.c
@@ -47,9 +47,9 @@ int usage_lf_viking_sim(void) {
 
 // calc checksum
 uint64_t getVikingBits(uint32_t id) {
-	uint8_t checksum = (id>>24) ^ ((id>>16) & 0xFF) ^ ((id>>8) & 0xFF) ^ (id & 0xFF) ^ 0xF2 ^ 0xA8;
+	uint8_t checksum = ((id>>24) & 0xFF) ^ ((id>>16) & 0xFF) ^ ((id>>8) & 0xFF) ^ (id & 0xFF) ^ 0xF2 ^ 0xA8;
 	uint64_t ret = (uint64_t)0xF2 << 56;
-	ret |= (id << 8);
+	ret |= (uint64_t)id << 8;
 	ret	|= checksum;
 	return ret;
 }
diff --git a/common/lfdemod.c b/common/lfdemod.c
index cb3e9f0b..f27ffff3 100644
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -679,10 +679,15 @@ int VikingDemod_AM(uint8_t *dest, size_t *size) {
 	uint8_t preamble[] = {1,1,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
 	uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
 	if (errChk == 0) return -4; //preamble not found
-	uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8)
-	    ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8) 
-	    ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8);
-	if ( checkCalc != 0xA8 ) return -5;
+	uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ 
+						 bytebits_to_byte(dest+startIdx+8,8) ^ 
+						 bytebits_to_byte(dest+startIdx+16,8) ^ 
+						 bytebits_to_byte(dest+startIdx+24,8) ^ 
+						 bytebits_to_byte(dest+startIdx+32,8) ^ 
+						 bytebits_to_byte(dest+startIdx+40,8) ^ 
+						 bytebits_to_byte(dest+startIdx+48,8) ^ 
+						 bytebits_to_byte(dest+startIdx+56,8);
+	if ( checkCalc != 0xA8 ) return -5;	
 	if (*size != 64) return -6;
 	//return start position
 	return (int) startIdx;
-- 
2.39.2