DTLS: Set server record layer version(s) earlier

- enable several DTLS tests that can now work cleanly

Author: peterdettman

tls/src/main/java/org/bouncycastle/tls/DTLSServerProtocol.java

@@ -117,9 +117,6 @@ protected DTLSTransport serverHandshake(ServerHandshakeState state, DTLSRequest
         {
             clientMessage = handshake.receiveMessage();
 
-            // NOTE: DTLSRecordLayer requires any DTLS version, we don't otherwise constrain this
-//            ProtocolVersion recordLayerVersion = recordLayer.getReadVersion();
-
             if (clientMessage.getType() == HandshakeType.client_hello)
             {
                 processClientHello(state, clientMessage.getBody());
@@ -141,13 +138,6 @@ protected DTLSTransport serverHandshake(ServerHandshakeState state, DTLSRequest
         {
             byte[] serverHelloBody = generateServerHello(state);
 
-            // TODO[dtls13] Ideally, move this into generateServerHello once legacy_record_version clarified
-            {
-                ProtocolVersion recordLayerVersion = serverContext.getServerVersion();
-                recordLayer.setReadVersion(recordLayerVersion);
-                recordLayer.setWriteVersion(recordLayerVersion);
-            }
-
             handshake.sendMessage(HandshakeType.server_hello, serverHelloBody);
         }
 
@@ -460,8 +450,6 @@ protected byte[] generateServerHello(ServerHandshakeState state)
         TlsServerContextImpl serverContext = state.serverContext;
         SecurityParameters securityParameters = serverContext.getSecurityParametersHandshake();
 
-        // TODO[dtls13] Negotiate cipher suite first?
-
         ProtocolVersion serverVersion;
 
         // NOT renegotiating
@@ -477,22 +465,24 @@ protected byte[] generateServerHello(ServerHandshakeState state)
 //                ? ProtocolVersion.DTLSv12
 //                : server_version;
 //
-//            recordLayer.setWriteVersion(legacy_record_version);
+//            state.recordLayer.setWriteVersion(legacy_record_version);
             securityParameters.negotiatedVersion = serverVersion;
         }
 
         // TODO[dtls13]
 //        if (ProtocolVersion.DTLSv13.isEqualOrEarlierVersionOf(serverVersion))
 //        {
 //            // See RFC 8446 D.4.
-//            recordStream.setIgnoreChangeCipherSpec(true);
+//            state.recordLayer.setIgnoreChangeCipherSpec(true);
 //
-//            recordStream.setWriteVersion(ProtocolVersion.DTLSv12);
+//            state.recordLayer.setReadVersion(ProtocolVersion.DTLSv12);
+//            state.recordLayer.setWriteVersion(ProtocolVersion.DTLSv12);
 //
 //            return generate13ServerHello(clientHello, clientHelloMessage, false);
 //        }
-//
-//        recordStream.setWriteVersion(serverVersion);
+
+        state.recordLayer.setReadVersion(serverVersion);
+        state.recordLayer.setWriteVersion(serverVersion);
 
         {
             boolean useGMTUnixTime = server.shouldUseGMTUnixTime();
@@ -845,6 +835,8 @@ protected void processClientHello(ServerHandshakeState state, byte[] body)
     protected void processClientHello(ServerHandshakeState state, ClientHello clientHello)
         throws IOException
     {
+        state.recordLayer.setWriteVersion(ProtocolVersion.DTLSv10);
+
         state.clientHello = clientHello;
 
         // TODO Read RFCs for guidance on the expected record layer version number

tls/src/test/java/org/bouncycastle/tls/test/DTLSRawKeysProtocolTest.java

@@ -3,6 +3,7 @@
 import java.security.SecureRandom;
 
 import org.bouncycastle.crypto.params.Ed25519PrivateKeyParameters;
+import org.bouncycastle.tls.AlertDescription;
 import org.bouncycastle.tls.CertificateType;
 import org.bouncycastle.tls.DTLSClientProtocol;
 import org.bouncycastle.tls.DTLSRequest;
@@ -13,6 +14,7 @@
 import org.bouncycastle.tls.ProtocolVersion;
 import org.bouncycastle.tls.TlsClient;
 import org.bouncycastle.tls.TlsExtensionsUtils;
+import org.bouncycastle.tls.TlsFatalAlertReceived;
 import org.bouncycastle.tls.TlsServer;
 import org.bouncycastle.tls.crypto.TlsCrypto;
 import org.bouncycastle.util.Arrays;
@@ -206,8 +208,6 @@ private void testServerUsesX509AndClientUsesRawKey(ProtocolVersion tlsVersion) t
         pumpData(client, server);
     }
 
-    // NOTE: Test disabled because of problems getting a clean exit of the DTLS server after a fatal alert.
-/*
     public void testClientSendsClientCertExtensionButServerHasNoCommonTypes() throws Exception
     {
         testClientSendsClientCertExtensionButServerHasNoCommonTypes(ProtocolVersion.DTLSv12);
@@ -244,10 +244,7 @@ private void testClientSendsClientCertExtensionButServerHasNoCommonTypes(Protoco
             assertEquals("Should have caused unsupported_certificate alert", alert.getAlertDescription(), AlertDescription.unsupported_certificate);
         }
     }
-*/
 
-    // NOTE: Test disabled because of problems getting a clean exit of the DTLS server after a fatal alert.
-/*
     public void testClientSendsServerCertExtensionButServerHasNoCommonTypes() throws Exception
     {
         testClientSendsServerCertExtensionButServerHasNoCommonTypes(ProtocolVersion.DTLSv12);
@@ -284,7 +281,6 @@ private void testClientSendsServerCertExtensionButServerHasNoCommonTypes(Protoco
             assertEquals("Should have caused unsupported_certificate alert", alert.getAlertDescription(), AlertDescription.unsupported_certificate);
         }
     }
-*/
 
     private Ed25519PrivateKeyParameters generateKeyPair()
     {

tls/src/test/java/org/bouncycastle/tls/test/DTLSTestSuite.java

@@ -43,20 +43,14 @@ private static void addFallbackTests(TestSuite testSuite)
             addTestCase(testSuite, c, "FallbackGood");
         }
 
-        /*
-         * NOTE: Temporarily disabled automatic test runs because of problems getting a clean exit
-         * of the DTLS server after a fatal alert. As of writing, manual runs show the correct
-         * alerts being raised
-         */
+        {
+            TlsTestConfig c = createDTLSTestConfig(ProtocolVersion.DTLSv12);
+            c.clientFallback = true;
+            c.clientSupportedVersions = ProtocolVersion.DTLSv10.only();
+            c.expectServerFatalAlert(AlertDescription.inappropriate_fallback);
 
-//        {
-//            TlsTestConfig c = createDTLSTestConfig(ProtocolVersion.DTLSv12);
-//            c.clientFallback = true;
-//            c.clientSupportedVersions = ProtocolVersion.DTLSv10.only();
-//            c.expectServerFatalAlert(AlertDescription.inappropriate_fallback);
-//
-//            addTestCase(testSuite, c, "FallbackBad");
-//        }
+            addTestCase(testSuite, c, "FallbackBad");
+        }
 
         {
             TlsTestConfig c = createDTLSTestConfig(ProtocolVersion.DTLSv12);