verify(mockDeferredNdrBuffer, times(9)).enc_ndr_long(anyInt()); // 3 enc_ndr_long for each of 3 unicode strings
        verify(mockDeferredNdrBuffer, times(3)).enc_ndr_long(0);
        verify(mockDeferredNdrBuffer, times(3)).advance(anyInt());
        verify(mockDeferredNdrBuffer, times(4)).derive(anyInt()); // 3 for strings + 1 for guid

            // Given
            when(mockResource.openInputStream()).thenReturn(mockInputStream);
            when(mockResource.openInputStream(anyInt())).thenReturn(mockInputStream);
            when(mockResource.openInputStream(anyInt(), anyInt(), anyInt())).thenReturn(mockInputStream);

            // When
            InputStream is1 = mockResource.openInputStream();

        assertEquals("Invalid token", ex.getMessage());

        // Ensure mechContext was not engaged due to early failure
        verify(this.mechContext, never()).initSecContext(any(), anyInt(), anyInt());
    }

    @Test
    @DisplayName("initSecContext with null buffer and non-zero len throws NPE")
    void testInitSecContextNullBufferNonZeroLen() throws Exception {

        // Set the deferred field directly since it's a public field, not a method
        mockNdrBuffer.deferred = mockDeferredBuffer;
        lenient().when(mockNdrBuffer.derive(anyInt())).thenReturn(mockDeferredBuffer);
        lenient().when(mockDeferredBuffer.derive(anyInt())).thenReturn(mockDeferredBuffer);
    }

    @Test
    void testGetSyntax() {
        String syntax = srvsvc.getSyntax();

            response.setAsync(true);

            boolean result = response.verifySignature(buffer, 0, 100);

            assertTrue(result);
            verify(mockDigest, never()).verify(any(), anyInt(), anyInt(), anyInt(), any());
        }

        @Test
        @DisplayName("Should skip verification when digest is null")
        void testVerifySignatureNoDigest() {
            byte[] buffer = new byte[100];

import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyInt;
import static org.mockito.ArgumentMatchers.eq;
import static org.mockito.Mockito.inOrder;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.reset;

import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyInt;
import static org.mockito.Mockito.doAnswer;
import static org.mockito.Mockito.doReturn;
import static org.mockito.Mockito.doThrow;
import static org.mockito.Mockito.lenient;
import static org.mockito.Mockito.spy;

import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyInt;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import java.net.UnknownHostException;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyInt;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import java.lang.reflect.Field;

import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyInt;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import java.util.Properties;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;