1 --[[ builtin/base64.lua ]]--
3 -- Taken from: http://lua-users.org/wiki/BaseSixtyFour with minor modifications
5 -- Lua 5.1+ base64 v3.0 (c) 2009 by Alex Kloss <alexthkloss@web.de>
6 -- licensed under the terms of the LGPL2
9 package.loaded.base64 = base64
11 -- character table string
12 local b='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
15 function base64.encode(data)
16 return ((data:gsub('.', function(x)
18 for i=8,1,-1 do r=r..(b%2^i-b%2^(i-1)>0 and '1' or '0') end
20 end)..'0000'):gsub('%d%d%d?%d?%d?%d?', function(x)
21 if (#x < 6) then return '' end
23 for i=1,6 do c=c+(x:sub(i,i)=='1' and 2^(6-i) or 0) end
25 end)..({ '', '==', '=' })[#data%3+1])
29 function base64.decode(data)
30 data = string.gsub(data, '[^'..b..'=]', '')
31 return (data:gsub('.', function(x)
32 if (x == '=') then return '' end
33 local r,f='',(b:find(x)-1)
34 for i=6,1,-1 do r=r..(f%2^i-f%2^(i-1)>0 and '1' or '0') end
36 end):gsub('%d%d%d?%d?%d?%d?%d?%d?', function(x)
37 if (#x ~= 8) then return '' end
39 for i=1,8 do c=c+(x:sub(i,i)=='1' and 2^(8-i) or 0) end