Add some protections against the incorrect cert type being used

ios/NebulaNetworkExtension/Site.swift

@@ -362,11 +362,7 @@ struct IncomingSite: Codable {
         }
         
         proto.providerConfiguration = ["config": rawConfig]
-
-        //TODO: proto is a subclass and we should probably set some settings on the parents
-        //TODO: set these to meaningful values, or not at all
-        proto.serverAddress = "TODO"
-        proto.username = "TEST USERNAME"
+        proto.serverAddress = "Nebula"
         
         // Finish up the manager, this is what stores everything at the system level
         manager.protocolConfiguration = proto

lib/components/SiteItem.dart

@@ -28,7 +28,7 @@ class SiteItem extends StatelessWidget {
   Widget _buildContent(BuildContext context) {
     final border = BorderSide(color: Utils.configSectionBorder(context));
     var ip = "Error";
-    if (site.cert != null) {
+    if (site.cert != null && site.cert.cert.details.ips.length > 0) {
       ip = site.cert.cert.details.ips[0];
     }
 

lib/screens/siteConfig/CAListScreen.dart

@@ -99,12 +99,22 @@ class _CAListScreenState extends State<CAListScreen> {
     //TODO: show an error popup
     try {
       var rawCerts = await platform.invokeMethod("nebula.parseCerts", <String, String>{"certs": ca});
+      var ignored = 0;
+
       List<dynamic> certs = jsonDecode(rawCerts);
       certs.forEach((rawCert) {
         final info = CertificateInfo.fromJson(rawCert);
+        if (!info.cert.details.isCa) {
+          ignored++;
+          return;
+        }
         cas[info.cert.fingerprint] = info;
       });
 
+      if (ignored > 0) {
+        error = 'One or more certificates were ignored because they were not certificate authorities.';
+      }
+
       changed = true;
     } on PlatformException catch (err) {
       //TODO: fix this message

lib/screens/siteConfig/CertificateScreen.dart

@@ -285,7 +285,12 @@ class _CertificateScreenState extends State<CertificateScreen> {
       var rawCerts = await platform.invokeMethod("nebula.parseCerts", <String, String>{"certs": rawCert});
       List<dynamic> certs = jsonDecode(rawCerts);
       if (certs.length > 0) {
-        cert = CertificateInfo.fromJson(certs.first);
+        var tryCert = CertificateInfo.fromJson(certs.first);
+        if (tryCert.cert.details.isCa) {
+          return callback('A certificate authority is not appropriate for a client certificate.');
+        }
+        //TODO: test that the pubkey matches the privkey
+        cert = tryCert;
       }
     } on PlatformException catch (err) {
       error = err.details ?? err.message;