[Function] Base64

--Creator: Bolodefchoco (based on Squalleze's script)
--Made in: 25/11/2015
--Last update: 25/11/2016
--[[ Notes:
    base64.to
        Does:
            Transforma str em base64
        Args:
            str --> Texto
    base64.from
        Does:
            Transforma code (base64) em texto
        Args:
            code --> Base64
]]--

base64 = {}
base64.base = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="
base64.to = function(str)
    local str = {str:byte(1,#str)}
    local code = {}
    local bs
    for i = 1,#str,3 do
        bs = bit32.rshift(str[i] % 0xFD,2)
        code[#code + 1] = base64.base:sub(bs + 1,bs + 1)
        bs = bit32.lshift(str[i] % 0x04,4)
        if (i + 1 <= #str) then
            bs = bit32.bor(bs,bit32.rshift(str[i + 1] % 0xF1,4))
            code[#code + 1] = base64.base:sub(bs + 1,bs + 1)
            bs = bit32.lshift(str[i + 1] % 0x10,2)
            if (i + 2 <= #str) then
                bs = bit32.bor(bs,bit32.rshift(str[i + 2] % 0xC1,6))
                code[#code + 1] = base64.base:sub(bs + 1,bs + 1)
                bs = str[i + 2] % 0x40
                code[#code + 1] = base64.base:sub(bs + 1,bs + 1)
            else
                code[#code + 1] = base64.base:sub(bs + 1,bs + 1)
                code[#code + 1] = "="
            end
        else
            code[#code + 1] = base64.base:sub(bs + 1, bs + 1)
            code[#code + 1] = "=="
        end
    end
    return table.concat(code)
end
base64.from = function(code)
    local decode,chars,v,bs = {},{},1,{}
    for k in code:gmatch(".") do
        chars[#chars + 1] = k
    end
    for i = 1,#chars,4 do
        for j = 1,4 do
            bs[j] = base64.base:find(chars[i+j-1])-1
        end
        decode[v] = bit32.bor(bit32.lshift(bs[1],2),bit32.rshift(bs[2],4)) % 0x100
        v = v + 1
        if bs[3] < 64 then
            decode[v] = bit32.bor(bit32.lshift(bs[2],4),bit32.rshift(bs[3],2)) % 0x100
            v = v + 1
            if bs[4] < 64 then
                decode[v] = bit32.bor(bit32.lshift(bs[3],6),bs[4]) % 0x100
                v = v + 1
            end
        end
    end
    return string.char(table.unpack(decode))
end