If you are using a HSM your long-term authenticity key won't be in the memory space of the process with openssl inside it. So that should be OK. However, ever

If you are using a HSM your long-term authenticity key won't be in the memory space of the process with openssl inside it. So that should be OK. However, everything else in that process (like, all the traffic you were hoping to protect) is basically toast.