Binary package “lacme” in ubuntu eoan

ACME client written with process isolation and minimal privileges in mind

 lacme is divided into four components, each with its own executable:
  * A process to manage the account key and issue SHA-256 signatures needed for
    each ACME command. (This process binds to a UNIX-domain socket to reply to
    signature requests from the ACME client.) One can use the UNIX-domain
    socket forwarding facility of OpenSSH 6.7 and later to run this process on
    a different host.
  * A "master" process, which runs as root and is the only component
    with access to the private key material of the server keys. It is used to
    fork the ACME client (and optionally the ACME webserver) after dropping
    root privileges. For certificate issuances, it also generates Certificate
    Signing Requests, then verifies the validity of the issued certificate, and
    optionally reloads or restarts services.
  * An actual ACME client, which builds ACME commands and dialogues with
    the remote ACME server. Since ACME commands need to be signed with the
    account key, the "master" process passes the UNIX-domain socket of the
    account key manager to the ACME client: data signatures are requested by
    writing the data to be signed to the socket.
  * For certificate issuances, an optional webserver, which is spawned
    by the "master" process when no service is listening on the HTTP port.
    (The only challenge type currently supported is "http-01", which requires a
    webserver to answer challenges.) That webserver only processes GET and
    HEAD requests under the "/.well-known/acme-challenge/" URI. By default
    some iptables(8) rules are automatically installed to open the HTTP port,
    and removed afterwards.