X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/1eb874ee3f7690cc92a720c0636fbe100e82b1e5..12d708fec157dfde6f94d61e5fdc265713a71578:/client/lualibs/utils.lua

diff --git a/client/lualibs/utils.lua b/client/lualibs/utils.lua
index e84f70ad..f7749ca6 100644
--- a/client/lualibs/utils.lua
+++ b/client/lualibs/utils.lua
@@ -108,6 +108,24 @@ local Utils =
 		return retval
 	end,
 	
+	-- input parameter is a string
+	-- Swaps the endianess and returns a string,  
+	-- IE:  'cd7a' -> '7acd'  -> 0x7acd
+	SwapEndiannessStr = function(s, len)
+		if s == nil then return nil end
+		if #s == 0 then return '' end
+		if  type(s) ~= 'string' then return nil end
+		
+		local retval
+		if len == 16 then
+			retval = s:sub(3,4)..s:sub(1,2)
+		elseif len == 24 then
+			retval = s:sub(5,6)..s:sub(3,4)..s:sub(1,2)
+		elseif len == 32 then
+			retval = s:sub(7,8)..s:sub(5,6)..s:sub(3,4)..s:sub(1,2)
+		end
+		return retval
+	end,	
 	------------ CONVERSIONS
 	
 	--
@@ -116,8 +134,8 @@ local Utils =
 		local B,K,OUT,I,D=16,"0123456789ABCDEF","",0
 		while IN>0 do
 			I=I+1
-			IN,D=math.floor(IN/B),math.mod(IN,B)+1
-			OUT=string.sub(K,D,D)..OUT
+			IN , D = math.floor(IN/B), math.modf(IN,B)+1
+			OUT = string.sub(K,D,D)..OUT
 		end
 		return OUT
 	end,
@@ -129,7 +147,7 @@ local Utils =
 		end
 		local s={}
 		for i = 1, #(bytes) do
-			s[i] =   string.format("%02X",bytes[i]) 
+			s[i] = string.format("%02X",bytes[i]) 
 		end
 		return table.concat(s)
 	end,	
@@ -173,6 +191,30 @@ local Utils =
 		return  table.concat(t)	
 	end,
 	
+	Chars2num = function(s)
+        return (s:byte(1)*16777216)+(s:byte(2)*65536)+(s:byte(3)*256)+(s:byte(4))
+	end,
+	
+	-- use length of string to determine 8,16,32,64 bits
+	bytes_to_int = function(str,endian,signed) 
+		local t={str:byte(1,-1)}
+		if endian=="big" then --reverse bytes
+			local tt={}
+			for k=1,#t do
+				tt[#t-k+1]=t[k]
+			end
+			t=tt
+		end
+		local n=0
+		for k=1,#t do
+			n=n+t[k]*2^((k-1)*8)
+		end
+		if signed then
+			n = (n > 2^(#t*8-1) -1) and (n - 2^(#t*8)) or n -- if last bit set, negative.
+		end
+		return n
+	end,
+	
 	-- function convertStringToBytes(str)
 	-- local bytes = {}
 	-- local strLength = string.len(str)