ComputerCraft relench

--[[
             relenc
 an "encryption" library for CCLua

 made by relative

 Credits:
   base64 - lua-users.org/wiki/BaseSixtyFour
--]]
--[[ BASE64 ]]--
local b='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
local function base64encode(data)
    return ((data:gsub('.', function(x)
      local r,b='',x:byte()
      for i=8,1,-1 do r=r..(b%2^i-b%2^(i-1)>0 and '1' or '0') end
      return r;
    end)..'0000'):gsub('%d%d%d?%d?%d?%d?', function(x)
      if(#x < 6) then return '' end
      local c=0
      for i=1,6 do c=c+(x:sub(i,i)=='1' and 2^(6-i) or 0) end
      return b:sub(c+1,c+1)
    end)..({'', '==', '='})[#data%3+1])
end
local function base64decode(data)
  data = string.gsub(data, '[^'..b..'=]', '')
  return (data:gsub('.', function(x)
    if (x=='=') then return '' end
    local r,f='',(b:find(x)-1)
    for i=6,1,-1 do r=r..(f%2^i-f%2^(i-1)>0 and '1' or '0') end
    return r;
  end):gsub('%d%d%d?%d?%d?%d?%d?%d?', function(x)
    if(#x ~= 8) then return '' end
    local c=0
    for i=1,8 do c=c+(x:sub(i,i)=='1' and 2^(8-i) or 0) end
    return string.char(c)
  end))
end
local ENCTESTP = "RU5DT0RFX1RFU1Q="
local ENCTESTS = base64encode("ENCODE_TEST")
local DECTESTP = "DECODE_TEST"
local DECTESTS = base64decode(base64encode(DECTESTP))
if ENCTESTP ~= ENCTESTS then
  error("Base64 encode test FAILED.")
end
if DECTESTP ~= DECTESTS then
  error("Base64 decode test FAILED.")
end

--[[ Encoding ]]--

function encode(str)
  return base64encode(str)
end

function decode(str)
  return base64decode(str)
end