assertTrue(result);
        verify(signingDigest).verify(testData, offset, length, extraPad, message);
    }

    @Test
    @DisplayName("Test sign method with null request and response")
    void testSignWithNullMessages() {
        // Arrange
        int offset = 0;
        int length = testData.length;

        // Act
        signingDigest.sign(testData, offset, length, null, null);

        // Assert