Mockito.when(mock.getLogonInfo()).thenReturn(mockLogonInfo);
            Mockito.when(mock.getServerSignature()).thenReturn(mockServerSig);
            Mockito.when(mock.getKdcSignature()).thenReturn(mockKdcSig);
        })) {

            // Create minimal PAC data
            byte[] pacData = createMinimalPacData();

            // Test constructor

            try {
                Pac pac = new Pac(pacData, keys);
                assertNotNull(pac.getServerSignature());
                assertNotNull(pac.getKdcSignature());
            } catch (PACDecodingException e) {
                // Expected due to invalid logon info structure
                assertNotNull(e.getMessage());
            }
        }
    }

        return this.serverSignature;
    }

    /**
     * Returns the KDC signature used to validate PAC authenticity.
     * @return the KDC signature
     */
    public PacSignature getKdcSignature() {
        return this.kdcSignature;
    }