/*
 * JobServerAuthenticationTest
 *
 * v1.0
 *
 * May 21, 2019
 */

package JobServ;

import static org.junit.Assert.assertEquals;
import static org.mockito.AdditionalAnswers.delegatesTo;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;

import io.grpc.ManagedChannel;
import io.grpc.inprocess.InProcessChannelBuilder;
import io.grpc.inprocess.InProcessServerBuilder;
import io.grpc.stub.StreamObserver;
import io.grpc.testing.GrpcCleanupRule;
import io.grpc.netty.GrpcSslContexts;

import io.netty.handler.ssl.ClientAuth;
import io.netty.handler.ssl.SslContext;
import io.netty.handler.ssl.SslContextBuilder;
import io.netty.handler.ssl.SslProvider;

import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
import org.mockito.ArgumentCaptor;
import org.mockito.ArgumentMatchers;

/*
 * JobServerAuthenticationTest
 * Creates a client using authorized certs and another one using unauthorized certs
 * Ensures only the client with authorized certs can connect to the server.
 * For more information on the hardcoded paths check buildwrapper.sh
 */

@RunWith(JUnit4.class)
public class JobServerAuthorizationTest {

    // Authorized client key/cert/ca
    private final String clientCa = "resources/client/ca.crt";
    private final String clientKey = "resources/client/private.pem";
    private final String clientCert = "resources/client/client.crt";

    // Authorized server key/cert/ca
    private final String serverCa = "resources/server/ca.crt";
    private final String serverKey = "resources/server/private.pem";
    private final String serverCert = "resources/server/server.crt";

    // controlled failure key/cert/ca
    private final String badCa = "resources/test/ca.crt";
    private final String badKey = "resources/test/private.pem";
    private final String badCert = "resources/test/test.crt";

    // Automates (graceful) shutdown at end of tests
    @Rule
    public final GrpcCleanupRule grpcCleanup = newCleanupRule();

    private final ShellServerGrpc.ShellServerImplBase = mock(ShellServerGrpc.ShellServerImplBase.class,
					     delegatesTo(new ShellServerGrpc.ShellServerImplBase() {}));

    // badClient uses unauthorized certs
    private JobServClient goodClient;
    private JobServClient badClient;

    // was setUp able to use SSL Certs
    private Boolean serverSslInitialized;
    private Boolean clientSslInitialized;
    
    /*
     * setUp()
     * generates both clients and the server
     */
    @Before
    public void setUp() throws Exception {
	String serverName = InProcessServerBuilder.generateName();

	try {
	// generate SSL contexts
	SslContextBuilder serverContextBuilder = SslContextBuilder.forServer(new File(serverCert),
									     new File(serverKey));
	serverContextBuilder.trustManager(new File(clientCa));
	serverContextBuilder.clientAuth(ClientAuth.REQUIRE);

	grpcCleanup.register(InProcessServerBuilder.forName(serverName)
			     .sslContext(serverContextBuilder.build())
			     .directExecutor()
			     .addService(this.serviceImpl);
			     .build().start()); 
	
	this.serverSslInitialized = true;
	
	} catch (SSLException e) {
	    // One of the certs or keys was bad, ssl cannot be used
	    this.serverSslInitialized = false;
	    grpcCleanup.register(InProcessServerBuilder.forName(serverName)
				 .directExecutor()
				 .addService(this.serviceImpl).build().start());
	}

	// generate ssl for clients
        if (this.serverSslInitialized) {
	    try {
		SslContextBuilder goodClientBuilder = SslContextBuilder.forClient();
		goodClientBuilder.trustManager(new File(serverCa));
		goodClientBuilder.keyManager(new File(clientCert),  new File(clientKey));

		SslContextBuilder badClientBuilder = SslContextBuilder.forClient();
		badClientBuilder.trustManager(new File(serverCa));
		badClientBuilder.keyManager(new File(badCert), new File(badKey));

		ManagedChannel goodChannel = grpcCleanup.register(InProcessChannelBuilder.forName(serverName)
								  .sslContext(goodClientBuilder.build())
								  .directExecutor()
								  .build()); 

		ManagedChannel badChannel = grpcCleanup.register(InProcessChannelBuilder.forName(serverName)
								 .sslContext(badClientBuilder.build())
								 .directExecutor()
								 .build());
		
		goodClient = new JobServClient(goodChannel);
		badClient = new JobServClient(badChannel);
		this.clientSslInitialized = true;

	    } catch (SSLException e) {
		this.clientSslInitialized = false;
		ManagedChannel nonSslChannel = grpcCleanup.register(InProcessChannelBuilder.forName(serverName)
								    .directExecutor()
								    .build());
		goodClient = new JobServClient(nonSslChannel);
		badClient = null; // 
	    }
	}
    }

    /*
     * Server TLS Test
     * fails if server SslContext generation threw an SSLException
     */
    @Test
    public void serverTlsTest() {
	assertEquals(this.serverSslInitialized, true);
    }

    /*
     * Client TLS Test
     * fails if client SslContext generation threw an SSL Exception
     */
    @Test
    public void clientTlsTest() {
	assertEquals(this.clientSslInitialized, true);
    }

    /*
     * TLS Cert Auth Negative Test
     * fails if badClient can successfully make requests of the server
     */
    @Test
    public void certAuthNegTest() {
	assertEquals(clientSslInitialized, true);
	int result = badClient.sendNewJobMessage("test command");
	assertEquals(result, -2);
    }

    /*
     * TLS Cert Auth Positive Test
     * fails if goodClient cannot make requests of the server
     */
    @Test
    public void certAuthPosTest() {
	assertEquals(clientSslInitialized, true);
	int result = goodClient.sendNewJobMessage("test command");
	assertNotEquals(result, -2);
    }
}