client/lualibs/precalc.lua

   1 --[[
   2         This is an experimental lib.
   3 --]]
   4 local utils = require('utils')
   5
   6 -- LOOKUP Tables
   7 local perm = {}
   8 perm [1]= { 0x0, 0x1, 0x3, 0x2, 0x7, 0x6, 0x4, 0x5, 0xF, 0xE, 0xC, 0xD, 0x8, 0x9, 0xB, 0xA }
   9 perm [2]= { 0x1, 0x0, 0x2, 0x3, 0x6, 0x7, 0x5, 0x4, 0xE, 0xF, 0xD, 0xC, 0x9, 0x8, 0xA, 0xB }
  10 perm [3]= { 0x2, 0x3, 0x1, 0x0, 0x5, 0x4, 0x6, 0x7, 0xD, 0xC, 0xE, 0xF, 0xA, 0xB, 0x9, 0x8 }
  11 perm [4]= { 0x3, 0x2, 0x0, 0x1, 0x4, 0x5, 0x7, 0x6, 0xC, 0xD, 0xF, 0xE, 0xB, 0xA, 0x8, 0x9 }
  12 perm [5]= { 0x4, 0x5, 0x7, 0x6, 0x3, 0x2, 0x0, 0x1, 0xB, 0xA, 0x8, 0x9, 0xC, 0xD, 0xF, 0xE }
  13 perm [6]= { 0x5, 0x4, 0x6, 0x7, 0x2, 0x3, 0x1, 0x0, 0xA, 0xB, 0x9, 0x8, 0xD, 0xC, 0xE, 0xF }
  14 perm [7]= { 0x6, 0x7, 0x5, 0x4, 0x1, 0x0, 0x2, 0x3, 0x9, 0x8, 0xA, 0xB, 0xE, 0xF, 0xD, 0xC }
  15 perm [8]= { 0x7, 0x6, 0x4, 0x5, 0x0, 0x1, 0x3, 0x2, 0x8, 0x9, 0xB, 0xA, 0xF, 0xE, 0xC, 0xD }
  16 perm [9]= { 0x8, 0x9, 0xB, 0xA, 0xF, 0xE, 0xC, 0xD, 0x7, 0x6, 0x4, 0x5, 0x0, 0x1, 0x3, 0x2 }
  17 perm [10]= { 0x9, 0x8, 0xA, 0xB, 0xE, 0xF, 0xD, 0xC, 0x6, 0x7, 0x5, 0x4, 0x1, 0x0, 0x2, 0x3 }
  18 perm [11]= { 0xA, 0xB, 0x9, 0x8, 0xD, 0xC, 0xE, 0xF, 0x5, 0x4, 0x6, 0x7, 0x2, 0x3, 0x1, 0x0 }
  19 perm [12]= { 0xB, 0xA, 0x8, 0x9, 0xC, 0xD, 0xF, 0xE, 0x4, 0x5, 0x7, 0x6, 0x3, 0x2, 0x0, 0x1 }
  20 perm [13]= { 0xC, 0xD, 0xF, 0xE, 0xB, 0xA, 0x8, 0x9, 0x3, 0x2, 0x0, 0x1, 0x4, 0x5, 0x7, 0x6 }
  21 perm [14]= { 0xD, 0xC, 0xE, 0xF, 0xA, 0xB, 0x9, 0x8, 0x2, 0x3, 0x1, 0x0, 0x5, 0x4, 0x6, 0x7 }
  22 perm [15]= { 0xE, 0xF, 0xD, 0xC, 0x9, 0x8, 0xA, 0xB, 0x1, 0x0, 0x2, 0x3, 0x6, 0x7, 0x5, 0x4 }
  23 perm [16]= { 0xF, 0xE, 0xC, 0xD, 0x8, 0x9, 0xB, 0xA, 0x0, 0x1, 0x3, 0x2, 0x7, 0x6, 0x4, 0x5 }
  24
  25 local shifts = {}
  26 shifts[1]= { 0x4, 0x5, 0x7, 0x6, 0x3, 0x2, 0x0, 0x1, 0xB, 0xA, 0x8, 0x9, 0xC, 0xD, 0xF, 0xE }
  27 shifts[2]= { 0x4, 0xB, 0xB, 0x4, 0xB, 0x4, 0x4, 0xB, 0xA, 0x5, 0x5, 0xA, 0x5, 0xA, 0xA, 0x5 }
  28 shifts[3]= { 0xB, 0x6, 0x0, 0xD, 0xD, 0x0, 0x6, 0xB, 0x6, 0xB, 0xD, 0x0, 0x0, 0xD, 0xB, 0x6 }
  29 shifts[4]= { 0xE, 0x5, 0x9, 0x2, 0x0, 0xB, 0x7, 0xC, 0x3, 0x8, 0x4, 0xF, 0xD, 0x6, 0xA, 0x1 }
  30 shifts[5]= { 0x4, 0xE, 0x1, 0xB, 0xF, 0x5, 0xA, 0x0, 0x3, 0x9, 0x6, 0xC, 0x8, 0x2, 0xD, 0x7 }
  31 shifts[6]= { 0xA, 0x4, 0x7, 0x9, 0x0, 0xE, 0xD, 0x3, 0xE, 0x0, 0x3, 0xD, 0x4, 0xA, 0x9, 0x7 }
  32 shifts[7]= { 0xE, 0x6, 0xE, 0x6, 0xF, 0x7, 0xF, 0x7, 0xD, 0x5, 0xD, 0x5, 0xC, 0x4, 0xC, 0x4 }
  33 shifts[8]= { 0x7, 0x1, 0xB, 0xD, 0xE, 0x8, 0x2, 0x4, 0x4, 0x2, 0x8, 0xE, 0xD, 0xB, 0x1, 0x7 }
  34 shifts[9]= { 0xD, 0xB, 0x0, 0x6, 0x6, 0x0, 0xB, 0xD, 0xA, 0xC, 0x7, 0x1, 0x1, 0x7, 0xC, 0xA }
  35 shifts[10]= { 0xe, 0x1, 0x1, 0xe, 0x1, 0xe, 0xe, 0x1, 0x1, 0xe, 0xe, 0x1, 0xe, 0x1, 0x1, 0xe }
  36
  37 local function ApplyPermutationAndShifts( pos, value, nibble)
  38         local shiftbytes = shifts[pos]
  39         local shiftElem = shiftbytes[nibble+1] --one indexed
  40         local shiftOne = shiftbytes[1]
  41         local rs = bit32.bxor(value, bit32.bxor(shiftOne, shiftElem))
  42         return rs
  43 end
  44
  45 local function GetOne( uid, block )
  46
  47         if uid == nil then return nil, 'empty uid string' end
  48         if #uid == 0 then return nil, 'empty uid string' end
  49         if #uid ~= 8 then return nil, 'uid wrong length. Should be 4 hex bytes' end
  50         if type(block) ~= 'number' then return nil, 'block is not number' end
  51         if  block > 16 or block < 0 then return nil, 'block is out-of-range' end
  52
  53         local s = ('%s%02X'):format(uid,block)
  54         local nibble1 = tonumber(s:sub(1,1),16) + 1
  55
  56         local permuted = ''
  57         for i = 1, #s do
  58                 local el_row = shifts[i]
  59                 local el_value = el_row[nibble1]
  60                 j = 1
  61                 while j <= i do
  62                         if  i-j > 0 then
  63                                 local nibble = tonumber(s:sub(j+1,j+1),16)
  64                                 el_value = ApplyPermutationAndShifts(i-j, el_value, nibble)
  65                         end
  66                         j = j+1
  67                 end
  68                 permuted =('%s%X'):format(permuted,el_value)
  69         end
  70
  71         permuted = 'C2'..permuted
  72         local crc64numStr = utils.Crc64(permuted)
  73         local keybytes = utils.ConvertAsciiToBytes(crc64numStr, true)
  74         local key = utils.ConvertBytesToHex(keybytes)
  75         return key:sub(1,12)
  76 end
  77
  78 local PreCalc =
  79 {
  80         GetAll = function(id)
  81                 if id == nil then return nil, 'empty string' end
  82                 if #id == 0 then return nil, 'empty string' end
  83                 if #id ~= 8 then return nil, 'wrong length. Should be 4 hex bytes' end
  84
  85                 local list = '4b0b20107ccb'
  86                 for i = 1,15 do
  87                         local key, err  = GetOne(id,i)
  88                         if not key then return oops(err) end
  89                         list = list..key
  90                 end
  91                 return list
  92         end,
  93 }
  94 return PreCalc