--Wraps all I/O using base64 encoding.

return {
  b = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/',

  base64enc = function (self, 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 self.b:sub(c + 1, c + 1)
      end) .. ({
      '',
      '==',
      '=',
    })[#data % 3 + 1])
  end,

  base64dec = function (self, data)
    data = string.gsub(data, '[^' .. self.b .. '=]', '')
    return (data:gsub('.', function (x)
        if x == '=' then
          return ''
        end
        local r, f = '', (self.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,

  recv = function (self)
    local line, err = self.super:recv()
    if line == nil then
      return line, err
    end
    return self:base64dec(line)
  end,

  send = function (self, data)
    return self.super:send(self:base64enc(data))
  end,
}