Encrypted DNS: several host names, views per listen address, what named uses a certificate for

The setup takes several host names (one certificate for all; the health check says when the served certificate misses one), stored in the settings. Each listen address gets its own views for the host names' A/AAAA records (--address ADDR=VIEW,..., a view checkbox per address in the form), always local to the view, with a warning when a public view would get a private address; a view no longer given loses the address, other records of the names stay, and the form starts from where the records are now. Certificates (page and jarl cert show) say what named uses each for: DNS over TLS or HTTPS, on which addresses and ports.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/encdns/health.go

@@ -206,3 +206,40 @@ func describe(err error, e Endpoint) string {
 	}
 	return err.Error()
 }
+
+// RequireNames marks the probes whose certificate doesn't cover every host
+// name clients may use (the first is what the probe asked for).
+func (h *Health) RequireNames(hosts []string) {
+	for i := range h.Probes {
+		p := &h.Probes[i]
+		if p.Problem != "" || len(p.CertNames) == 0 {
+			continue
+		}
+		var missing []string
+		for _, host := range hosts {
+			if !nameCovered(p.CertNames, host) {
+				missing = append(missing, host)
+			}
+		}
+		if len(missing) > 0 {
+			p.OK = false
+			p.Problem = fmt.Sprintf("named serves a certificate for %s, which doesn't cover %s: clients using that name reject it", strings.Join(p.CertNames, ", "), strings.Join(missing, ", "))
+		}
+	}
+}
+
+func nameCovered(names []string, host string) bool {
+	host = strings.ToLower(strings.TrimSuffix(host, "."))
+	for _, n := range names {
+		n = strings.ToLower(strings.TrimSuffix(n, "."))
+		if n == host {
+			return true
+		}
+		if rest, ok := strings.CutPrefix(n, "*."); ok {
+			if _, parent, ok := strings.Cut(host, "."); ok && parent == rest {
+				return true
+			}
+		}
+	}
+	return false
+}