# File lib/openssl/buffering.rb, line 56
  def read(size=nil, buf=nil)
    if size == 0
      if buf
        buf.clear
      else
        buf = ""
      end
      return @eof ? nil : buf
    end
    until @eof
      break if size && size <= @rbuffer.size
      fill_rbuff
    end
    ret = consume_rbuff(size) || ""
    if buf
      buf.replace(ret)
      ret = buf
    end
    (size && ret.empty?) ? nil : ret
  end