Tweak which tests get run on .NET 6 Android

src/Couchbase.Lite.Shared/Sync/WebSocketWrapper.cs

@@ -36,7 +36,6 @@
 using Couchbase.Lite.Internal.Logging;
 using Couchbase.Lite.Support;
 using Couchbase.Lite.Util;
-
 using JetBrains.Annotations;
 
 using LiteCore.Interop;
@@ -927,6 +926,30 @@ private bool ValidateServerCert(object sender, X509Certificate certificate, X509
             #endif
 
             if (!onlySelfSigned && sslPolicyErrors != SslPolicyErrors.None) {
+#if NET6_0_OR_GREATER && __ANDROID__
+                // Workaround (part 1) for https://github.com/dotnet/runtime/issues/84202
+                WriteLog.To.Sync.I(Tag, "Checking system TrustManagerFactory");
+                var tmf = Javax.Net.Ssl.TrustManagerFactory.GetInstance(Javax.Net.Ssl.TrustManagerFactory.DefaultAlgorithm);
+                tmf.Init(default(Java.Security.KeyStore));
+                var cf = Java.Security.Cert.CertificateFactory.GetInstance("X.509");
+                foreach (var tm in tmf.GetTrustManagers()) {
+                    if(tm is Javax.Net.Ssl.IX509TrustManager x509tm) {
+                        var javaCert = cf.GenerateCertificate(new MemoryStream(cert2.GetRawCertData())) as Java.Security.Cert.X509Certificate;
+                        try { 
+                            x509tm.CheckServerTrusted(new[] { javaCert }, "RSA"); 
+                        } catch(Exception) {
+                            WriteLog.To.Sync.W(Tag, "TrustManager does not trust this server cert, moving to next one...");
+                            continue;
+                        }
+
+                        WriteLog.To.Sync.I(Tag, "TrustManager trusts this server cert");
+                        return true;
+                    }
+                }
+
+                WriteLog.To.Sync.W(Tag, "No more TrustManagers found, server cert is not trusted by system");
+#endif
+
                 WriteLog.To.Sync.W(Tag, $"Error validating TLS chain: {sslPolicyErrors}");
                 if (chain.ChainElements != null) {
                     foreach(var element in chain.ChainElements) {
@@ -956,6 +979,20 @@ private bool ValidateServerCert(object sender, X509Certificate certificate, X509
                     }
                 }
             } else if (onlySelfSigned) {
+#if NET6_0_OR_GREATER && __ANDROID__
+                // Workaround (part 2) for https://github.com/dotnet/runtime/issues/84202
+                if (chain.ChainElements.Count == 0) {
+                    WriteLog.To.Sync.I(Tag, "Working around weird behavior in .NET 6 Android (X509Chain empty...)");
+                    var isSelfSigned = cert2.IssuerName.Name == cert2.SubjectName.Name;
+                    if(!isSelfSigned) {
+                        WriteLog.To.Sync.E(Tag, "ValidateServerCert failed due to received lone cert not being self signed");
+                        _validationException = new TlsCertificateException("A non self-signed certificate was received in self-signed mode.",
+                        C4NetworkErrorCode.TLSCertUnknownRoot, X509ChainStatusFlags.ExplicitDistrust);
+                    }
+
+                    return isSelfSigned;
+                }
+#endif
                 if (chain.ChainElements.Count != 1) {
                     WriteLog.To.Sync.E(Tag, "ValidateServerCert failed due to cert chain ChainElements's Count != 1");
                     _validationException = new TlsCertificateException("A non self-signed certificate was received in self-signed mode.",

src/Couchbase.Lite.Tests.Shared/TLSIdentityTest.cs

@@ -77,7 +77,6 @@ public TLSIdentityTest()
         }
 
         #region TLSIdentity tests
-        #if !NET6_0_APPLE && !NET6_0_ANDROID
         [Fact]
         public void TestCreateGetDeleteServerIdentity() => CreateGetDeleteServerIdentity(true);
 
@@ -189,7 +188,6 @@ public void TestCertificateExpiration()
             // Delete 
             TLSIdentity.DeleteIdentity(_store, ServerCertLabel, null);
         }
-        #endif
         #endregion
 
         #region TLSIdentity tests helpers

src/Couchbase.Lite.Tests.Shared/URLEndpointListenerTest.cs

@@ -106,7 +106,6 @@ public URLEndpointListenerTest()
 
 
         #endregion
-        #if !NET6_0_APPLE && !NET6_0_ANDROID
         #region Public Methods
 
 
@@ -436,7 +435,10 @@ public void TestClientCertAuthenticatorRootCerts()
             TLSIdentity.DeleteIdentity(_store, ClientCertLabel, null);
             _listener.Stop();
         }
+#endif
 
+
+        #if !NET6_0_ANDROID
         [Fact]
         public void TestListenerWithImportIdentity()
         {
@@ -536,7 +538,7 @@ public void TestAcceptOnlySelfSignedCertMode()
                 false,//accept only self signed server cert
                 null,
                 //TODO: Need to handle Linux throwing different error TLSCertUntrusted (5008)
-                (int)CouchbaseLiteError.TLSCertUnknownRoot, //maui android 5006
+                (int)CouchbaseLiteError.TLSCertUnknownRoot,
                 CouchbaseLiteErrorType.CouchbaseLite
             );
 
@@ -812,14 +814,15 @@ public void TestMultipleReplicatorsOnReadOnlyListener()
 
         [Fact]//hang maui android
         public void TestDeleteWithActiveReplicationsAndURLEndpointListener() => WithActiveReplicationsAndURLEndpointListener(false);
-#endif
 
         [Fact]
         public void TestCloseWithActiveReplicatorAndURLEndpointListeners() => WithActiveReplicatorAndURLEndpointListeners(true);
 
         [Fact]
         public void TestDeleteWithActiveReplicatorAndURLEndpointListeners() => WithActiveReplicatorAndURLEndpointListeners(false);
 
+#endif
+
         [Fact]
         public void TestStopListener()
         {
@@ -911,7 +914,6 @@ public void TestCreateListenerConfigWithEmptyCollection()
         }
 
         #endregion
-        #endif
         #region Private Methods
 
         private void CollectionsPushPullReplication(bool continuous)
@@ -968,7 +970,24 @@ private void CollectionsPushPullReplication(bool continuous)
 
         private int GetEADDRINUSECode()
         {
-#if NET6_0_OR_GREATER || __MOBILE__
+#if NET6_0_OR_GREATER
+            if (OperatingSystem.IsAndroid() || OperatingSystem.IsLinux())
+            {
+                return 98;
+            }
+
+            if (OperatingSystem.IsIOS() || OperatingSystem.IsMacCatalyst() || OperatingSystem.IsMacOS())
+            {
+                return 48;
+            }
+
+            if (OperatingSystem.IsWindows())
+            {
+                return 100;
+            }
+
+            throw new PlatformNotSupportedException();
+#elif __MOBILE__
             if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
             {
                 return 100;