refining and adding tests

app.go

@@ -650,21 +650,11 @@ func (h *Headscale) getTLSSettings() (*tls.Config, error) {
 			log.Warn().Msg("Listening with TLS but ServerURL does not start with https://")
 		}
 
-		var clientAuthMode tls.ClientAuthType
+        clientAuthMode, err := h.GetClientAuthMode()
-		switch h.cfg.TLSClientAuthMode {
+
-		case DisabledClientAuth:
+        if err != nil {
-			// Client cert is _not_ required.
+            return nil, err
-			clientAuthMode = tls.NoClientCert
+        }
-		case RelaxedClientAuth:
-			// Client cert required, but _not verified_.
-			clientAuthMode = tls.RequireAnyClientCert
-		case EnforcedClientAuth:
-			// Client cert is _required and verified_.
-			clientAuthMode = tls.RequireAndVerifyClientCert
-		default:
-			return nil, Error("Invalid tls_client_auth_mode provided: " +
-				h.cfg.TLSClientAuthMode)
-		}
 
 		log.Info().Msg(fmt.Sprintf(
 			"Client authentication (mTLS) is \"%s\". See the docs to learn about configuring this setting.",
@@ -683,6 +673,27 @@ func (h *Headscale) getTLSSettings() (*tls.Config, error) {
 	}
 }
 
+// Look up the TLS constant relative to user-supplied TLS client
+// authentication mode.
+func (h *Headscale) GetClientAuthMode() (tls.ClientAuthType, error) {
+
+		switch h.cfg.TLSClientAuthMode {
+		case DisabledClientAuth:
+			// Client cert is _not_ required.
+			return tls.NoClientCert, nil
+		case RelaxedClientAuth:
+			// Client cert required, but _not verified_.
+			return tls.RequireAnyClientCert, nil
+		case EnforcedClientAuth:
+			// Client cert is _required and verified_.
+			return tls.RequireAndVerifyClientCert, nil
+		default:
+			return tls.NoClientCert, Error("Invalid tls_client_auth_mode provided: " +
+				h.cfg.TLSClientAuthMode)
+		}
+
+}
+
 func (h *Headscale) setLastStateChangeToNow(namespace string) {
 	now := time.Now().UTC()
 	lastStateUpdate.WithLabelValues("", "headscale").Set(float64(now.Unix()))

app_test.go

@@ -63,3 +63,25 @@ func (s *Suite) ResetDB(c *check.C) {
 	}
 	app.db = db
 }
+
+// Enusre an error is returned when an invalid auth mode
+// is supplied.
+func (s *Suite) TestInvalidClientAuthMode(c *check.C){
+    app.cfg.TLSClientAuthMode = "invalid"
+    _, err := app.GetClientAuthMode()
+    c.Assert(err, check.NotNil)
+}
+
+// Ensure that all client auth modes return a nil error
+func (s *Suite) TestAuthModes(c *check.C){
+
+    var modes = []string{"disabled", "relaxed", "enforced"}
+
+    for _, v := range modes {
+        app.cfg.TLSClientAuthMode = v
+        _, err := app.GetClientAuthMode()
+        c.Assert(err, check.IsNil)
+    }
+
+}
+