If no key is provided in the *acme.Client, one is generated, but it is not cached. This means that every restart of the server process will use a new account. This change caches the account key, if one is generated, so that restarts of the server process use the same key. Change-Id: I80f127b2cc79745a854b220b8918724ca228e87a Reviewed-on: https://go-review.googlesource.com/28980 Run-TryBot: Alex Vaghin <ddos@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Alex Vaghin <ddos@google.com>