diff --git a/client/cmdhfmfu.c b/client/cmdhfmfu.c
index e6f017763..85e73d034 100644
--- a/client/cmdhfmfu.c
+++ b/client/cmdhfmfu.c
@@ -322,6 +322,9 @@ static int ul_read(uint8_t page, uint8_t *response, uint16_t responseLength) {
 
 static int ul_comp_write(uint8_t page, uint8_t *data, uint8_t datalen) {
 
+    if (data == NULL) 
+        return -1;
+    
     uint8_t cmd[18];
     memset(cmd, 0x00, sizeof(cmd));
     datalen = (datalen > 16) ? 16 : datalen;
@@ -330,7 +333,7 @@ static int ul_comp_write(uint8_t page, uint8_t *data, uint8_t datalen) {
     cmd[1] = page;
     memcpy(cmd + 2, data, datalen);
 
-    uint8_t response[1] = {0xff};
+    uint8_t response[1] = {0xFF};
     ul_send_cmd_raw(cmd, 2 + datalen, response, sizeof(response));
     // ACK
     if (response[0] == 0x0a) return 0;
@@ -948,7 +951,7 @@ int CmdHF14AMfUInfo(const char *Cmd) {
     uint8_t pwd[4] = {0, 0, 0, 0};
     uint8_t *key = pwd;
     uint8_t pack[4] = {0, 0, 0, 0};
-    int len = 0;
+    int len;
     char tempStr[50];
 
     while (param_getchar(Cmd, cmdp) != 0x00 && !errors) {
diff --git a/client/cmdlft55xx.h b/client/cmdlft55xx.h
index f0a438ef5..25b8c7c17 100644
--- a/client/cmdlft55xx.h
+++ b/client/cmdlft55xx.h
@@ -26,7 +26,6 @@
 #include "lfdemod.h"
 #include "cmdhf14a.h" //for getTagInfo
 
-
 #define T55x7_CONFIGURATION_BLOCK 0x00
 #define T55x7_PAGE0 0x00
 #define T55x7_PAGE1 0x01
@@ -37,6 +36,7 @@
 #define T55X7_DEFAULT_CONFIG_BLOCK      0x000880E8  // ASK, compat mode, data rate 32, manchester, STT, 7 data blocks
 #define T55X7_RAW_CONFIG_BLOCK          0x000880E0  // ASK, compat mode, data rate 32, manchester, 7 data blocks
 #define T55X7_EM_UNIQUE_CONFIG_BLOCK    0x00148040  // ASK, emulate em4x02/unique - compat mode, manchester, data rate 64, 2 data blocks
+#define T55X7_EM_PAXTON_CONFIG_BLOCK    0x00148040  // ASK, emulate em4x02/paxton - compat mode, manchester, data rate 64, 2 data blocks
 // FDXB requires data inversion and BiPhase 57 is simply BiPhase 50 inverted, so we can either do it using the modulation scheme or the inversion flag
 // we've done both below to prove that it works either way, and the modulation value for BiPhase 50 in the Atmel data sheet of binary "10001" (17) is a typo,
 // and it should actually be "10000" (16)
@@ -53,6 +53,7 @@
 #define T55X7_PRESCO_CONFIG_BLOCK       0x00088088  // ASK, data rate 32, Manchester, 5 data blocks, STT
 #define T55X7_NEDAP_64_CONFIG_BLOCK     0x907f0042  // BiPhase,  data rate 64, 3 data blocks
 #define T55X7_NEDAP_128_CONFIG_BLOCK    0x907f0082  // BiPhase,  data rate 64, 5 data blocks
+
 #define T55X7_bin 0b0010
 
 #define T5555_DEFAULT_CONFIG_BLOCK      0x6001F004  // data rate 64 , ask, manchester, 2 data blocks?
diff --git a/client/loclass/cipher.c b/client/loclass/cipher.c
index da210d98f..2fe178829 100644
--- a/client/loclass/cipher.c
+++ b/client/loclass/cipher.c
@@ -87,9 +87,7 @@ bool B(State state) {
     bool x2 = state.b & 0x20;
     bool x3 = state.b & 0x10;
     bool x7 = state.b & 0x01;
-
     return x1 ^ x2 ^ x3 ^ x7;
-
 }
 
 
diff --git a/client/scripting.c b/client/scripting.c
index 82378bf76..e9ebe1dea 100644
--- a/client/scripting.c
+++ b/client/scripting.c
@@ -69,6 +69,13 @@ static int l_GetFromBigBuf(lua_State *L) {
         startindex = luaL_checknumber(L, 1);
         len = luaL_checknumber(L, 2);
     }
+    
+    if ( len == 0 ) {
+        //signal error by returning Nil, errorstring
+        lua_pushnil(L);
+        lua_pushstring(L, "You need to supply number of bytes larger than zero");
+        return 2; // two return values        
+    }
 
     uint8_t *data = calloc(len, sizeof(uint8_t));
     if (!data) {
@@ -118,6 +125,13 @@ static int l_GetFromFlashMem(lua_State *L) {
         startindex = luaL_checknumber(L, 1);
         len = luaL_checknumber(L, 2);
     }
+    
+    if ( len == 0 ) {
+        //signal error by returning Nil, errorstring
+        lua_pushnil(L);
+        lua_pushstring(L, "You need to supply number of bytes larger than zero");
+        return 2; // two return values        
+    }    
 
     uint8_t *data = calloc(len, sizeof(uint8_t));
     if (!data) {
@@ -627,7 +641,7 @@ static int l_hardnested(lua_State *L) {
 
     uint8_t key[6] = {0, 0, 0, 0, 0, 0};
     uint8_t trgkey[6] = {0, 0, 0, 0, 0, 0};
-    for (int i = 0; i < 32; i += 2) {
+    for (int i = 0; i < 12; i += 2) {
         sscanf(&p_key[i], "%02x", &tmp);
         key[i / 2] = tmp & 0xFF;
         if (haveTarget) {