ADD: added the crc8legic to Lua. call it with core.crc8legic

also a helper function to take a hexstring and calc the crc on it, was added inside utils.lua

   Call it inside a lua-script like this:

        local utils = require('utils')
        local data = '01020304'
	local crc = utils.Crc8Legic(data)
	print (uid,  ('%02x'):format(crc))

client/lualibs/utils.lua

@@ -82,6 +82,20 @@ local Utils =
 		return nil		
 	end,
 	
+	------------ CRC-16 ccitt checksums
+	-- Takes a hex string and calculates a crc16
+	Crc8Legic = function(s)
+		if s == nil then return nil end
+		if #s == 0 then return nil end
+		if  type(s) == 'string' then
+			local utils = require('utils')
+			local asc = utils.ConvertHexToAscii(s)
+			local hash = core.crc8legic(asc)
+			return hash
+		end
+		return nil
+	end,
+	
 	------------ CRC-16 ccitt checksums
 	-- Takes a hex string and calculates a crc16
 	Crc16 = function(s)
@@ -96,6 +110,7 @@ local Utils =
 		return nil
 	end,
 	
+	
 	------------ CRC-64 ecma checksums
 	-- Takes a hex string and calculates a crc64 ecma
 	Crc64 = function(s)

client/scripting.c

@@ -1,5 +1,6 @@
 //-----------------------------------------------------------------------------
 // Copyright (C) 2013 m h swende <martin at swende.se>
+// Modified 2015,2016, iceman 
 //
 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
 // at your option, any later version. See the LICENSE.txt file for the text of
@@ -7,23 +8,8 @@
 //-----------------------------------------------------------------------------
 // Some lua scripting glue to proxmark core.
 //-----------------------------------------------------------------------------
-
-#include <lua.h>
-#include <lualib.h>
-#include <lauxlib.h>
-#include "proxmark3.h"
-#include "usb_cmd.h"
-#include "cmdmain.h"
 #include "scripting.h"
-#include "util.h"
+
-#include "nonce2key/nonce2key.h"
-#include "../common/iso15693tools.h"
-#include "iso14443crc.h"
-#include "../common/crc16.h"
-#include "../common/crc64.h"
-#include "../common/sha1.h"
-#include "aes.h"
-#include "cmdcrc.h"
 /**
  * The following params expected:
  *  UsbCommand c
@@ -369,6 +355,16 @@ static int l_aes128encrypt_ecb(lua_State *L)
 	return 1;// return 1 to signal one return value
 }
 
+static int l_crc8legic(lua_State *L)
+{
+	size_t size;
+	const char *p_str = luaL_checklstring(L, 1, &size);
+
+	uint16_t retval = CRC8Legic( (uint8_t*) p_str, size);
+    lua_pushinteger(L, (int) retval);
+    return 1;
+}
+
 static int l_crc16(lua_State *L)
 {
 	size_t size;
@@ -510,6 +506,7 @@ int set_pm3_libraries(lua_State *L)
 		{"aes128_decrypt_ecb",          l_aes128decrypt_ecb},
 		{"aes128_encrypt",              l_aes128encrypt_cbc},		
 		{"aes128_encrypt_ecb",          l_aes128encrypt_ecb},
+		{"crc8legic",					l_crc8legic},
 		{"crc16",                       l_crc16},
 		{"crc64",                       l_crc64},
 		{"sha1",						l_sha1},

client/scripting.h

@@ -11,6 +11,21 @@
 #define SCRIPTING_H__
 
 #include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+#include "proxmark3.h"
+#include "usb_cmd.h"
+#include "cmdmain.h"
+#include "util.h"
+#include "nonce2key/nonce2key.h"
+#include "../common/iso15693tools.h"
+#include "iso14443crc.h"
+#include "../common/crc.h"
+#include "../common/crc16.h"
+#include "../common/crc64.h"
+#include "../common/sha1.h"
+#include "aes.h"
+#include "cmdcrc.h"
 
 /**
  * @brief set_libraries loads the core components of pm3 into the 'pm3'