Merge branch 'master' of https://github.com/Proxmark/proxmark3

[proxmark3-svn] / client / lualibs / utils.lua

diff --git a/client/lualibs/utils.lua b/client/lualibs/utils.lua
index e84f70ada526e99b36b69f5077f5be8208e2c587..f7749ca618be04e3ce25273541e65d17871c798e 100644 (file)
--- a/client/lualibs/utils.lua
+++ b/client/lualibs/utils.lua
@@ -108,6 +108,24 @@ local Utils =
                return retval\r
        end,\r
        \r
+       -- input parameter is a string\r
+       -- Swaps the endianess and returns a string,  \r
+       -- IE:  'cd7a' -> '7acd'  -> 0x7acd\r
+       SwapEndiannessStr = function(s, len)\r
+               if s == nil then return nil end\r
+               if #s == 0 then return '' end\r
+               if  type(s) ~= 'string' then return nil end\r
+               \r
+               local retval\r
+               if len == 16 then\r
+                       retval = s:sub(3,4)..s:sub(1,2)\r
+               elseif len == 24 then\r
+                       retval = s:sub(5,6)..s:sub(3,4)..s:sub(1,2)\r
+               elseif len == 32 then\r
+                       retval = s:sub(7,8)..s:sub(5,6)..s:sub(3,4)..s:sub(1,2)\r
+               end\r
+               return retval\r
+       end,    \r
        ------------ CONVERSIONS\r
        \r
        --\r
@@ -116,8 +134,8 @@ local Utils =
                local B,K,OUT,I,D=16,"0123456789ABCDEF","",0\r
                while IN>0 do\r
                        I=I+1\r
-                       IN,D=math.floor(IN/B),math.mod(IN,B)+1\r
-                       OUT=string.sub(K,D,D)..OUT\r
+                       IN , D = math.floor(IN/B), math.modf(IN,B)+1\r
+                       OUT = string.sub(K,D,D)..OUT\r
                end\r
                return OUT\r
        end,\r
@@ -129,7 +147,7 @@ local Utils =
                end\r
                local s={}\r
                for i = 1, #(bytes) do\r
-                       s[i] =   string.format("%02X",bytes[i]) \r
+                       s[i] = string.format("%02X",bytes[i]) \r
                end\r
                return table.concat(s)\r
        end,    \r
@@ -173,6 +191,30 @@ local Utils =
                return  table.concat(t) \r
        end,\r
        \r
+       Chars2num = function(s)\r
+        return (s:byte(1)*16777216)+(s:byte(2)*65536)+(s:byte(3)*256)+(s:byte(4))\r
+       end,\r
+       \r
+       -- use length of string to determine 8,16,32,64 bits\r
+       bytes_to_int = function(str,endian,signed) \r
+               local t={str:byte(1,-1)}\r
+               if endian=="big" then --reverse bytes\r
+                       local tt={}\r
+                       for k=1,#t do\r
+                               tt[#t-k+1]=t[k]\r
+                       end\r
+                       t=tt\r
+               end\r
+               local n=0\r
+               for k=1,#t do\r
+                       n=n+t[k]*2^((k-1)*8)\r
+               end\r
+               if signed then\r
+                       n = (n > 2^(#t*8-1) -1) and (n - 2^(#t*8)) or n -- if last bit set, negative.\r
+               end\r
+               return n\r
+       end,\r
+       \r
        -- function convertStringToBytes(str)\r
        -- local bytes = {}\r
        -- local strLength = string.len(str)\r