Mockito.when(mockContext.getCredentials()).thenReturn(mockCredentials);

        // Mock CredentialsInternal for session tests
        jcifs.smb.CredentialsInternal mockCredentialsInternal = Mockito.mock(jcifs.smb.CredentialsInternal.class);
        Mockito.when(mockCredentials.unwrap(jcifs.smb.CredentialsInternal.class)).thenReturn(mockCredentialsInternal);

        // Act & Assert
        // unwrap to interface itself should return same instance
        CredentialsInternal unwrapped = creds.unwrap(CredentialsInternal.class);
        assertNotNull(unwrapped, "unwrap to CredentialsInternal returns instance");
        assertSame(creds, unwrapped, "unwrap returns the same object instance");

        // Context and credentials wiring - used by most tests
        when(cifsContext.getCredentials()).thenReturn(credentials);
        when(credentials.unwrap(CredentialsInternal.class)).thenReturn(credentialsInternal);
        when(credentialsInternal.clone()).thenReturn(credentialsInternal);

        // Transport wiring - used by most tests
        when(transport.acquire()).thenReturn(transport);

public class SmbSessionImplSecurityTest {

    private CIFSContext mockContext;
    private SmbTransportImpl mockTransport;
    private Configuration mockConfig;
    private Credentials mockCredentials;
    private CredentialsInternal mockCredentialsInternal;

    @BeforeEach
    public void setUp() {
        mockContext = Mockito.mock(CIFSContext.class);
        mockTransport = Mockito.mock(SmbTransportImpl.class);

    void getSmbSession_createAndReuse() {
        // Arrange: minimal credentials chain so SmbSessionImpl constructor succeeds
        CredentialsInternal creds = mock(CredentialsInternal.class);
        when(ctx.getCredentials()).thenReturn(creds);
        when(creds.unwrap(CredentialsInternal.class)).thenReturn(creds);
        when(creds.clone()).thenReturn(creds);

        assertEquals(0, transport.getNumSessions());

import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.mockito.Mock;
import org.mockito.MockedStatic;
import org.mockito.MockitoAnnotations;

import jcifs.Credentials;
import jcifs.smb.CredentialsInternal;
import jcifs.smb.NtlmAuthenticator;
import jcifs.smb.NtlmPasswordAuthenticator;
import jcifs.smb.SmbAuthException;
import jcifs.smb.SmbRenewableCredentials;

class CIFSContextCredentialWrapperTest {

        JAASAuthenticator auth = spy(new JAASAuthenticator());
        // Avoid real JAAS by stubbing getSubject
        doReturn(new Subject()).when(auth).getSubject();

        // Act
        CredentialsInternal result = auth.renew();

        // Assert interaction and return value
        assertSame(auth, result);
        verify(auth, times(1)).getSubject();
    }

 * when the "guest" username is supplied. Use {@link AuthenticationType} instead.
 *
 * @author mbechler
 */
public class NtlmPasswordAuthenticator implements Principal, CredentialsInternal, Serializable, AutoCloseable {

    /**
     *
     */
    private static final long serialVersionUID = -4090263879887877186L;

     *            the lifetime in seconds
     */
    public void setLifeTime(int time) {
        this.contextLifetime = time;
    }

    /**
     * {@inheritDoc}
     *
     * @see jcifs.smb.CredentialsInternal#isAnonymous()
     */
    @Override
    public boolean isAnonymous() {
        return this.getSubject() == null && super.isAnonymous();
    }

    /**
     * {@inheritDoc}
     *