In the first Harry Potter book there was a magical item known as the sorcerer's stone. It provided an elixir which would indefinitely extend the drinker's lifespan if it were drunk on a regular basis.
However, this stone, like so many other promises of eternal life, is not real.
Besides, life's beauty lies in it's brevity. An infinite existence would be dull and purposeless. Why would anyone ever desire to exist forever? Your mortality is not a curse, it is a gift. Embrace it! If you spend your finite life in search of infinite life, then it is a life wasted.