SmbNegotiationResponse nego = mock(SmbNegotiationResponse.class);
        setField(transport, "negotiated", nego);
        when(nego.isSigningNegotiated()).thenReturn(true);
        when(nego.isSigningRequired()).thenReturn(false).thenReturn(true);

        assertTrue(transport.isSigningOptional());
        assertTrue(transport.isSigningEnforced());
    }

        if (cur != null) {
            return false;
        }
        if (this.transport.isSigningEnforced()) {
            return true;
        }
        return this.transport.getNegotiateResponse().isSigningNegotiated();
    }

    /**
     * @param digest
     *            the digest to set
     * @throws SmbException
     */
    private void setDigest(SMBSigningDigest digest) throws SmbException {

        if (this.signingEnforced) {
            return false;
        }
        final SmbNegotiationResponse nego = getNegotiateResponse();
        return nego.isSigningNegotiated() && !nego.isSigningRequired();
    }

    @Override
    public boolean isSigningEnforced() throws SmbException {
        if (this.signingEnforced) {
            return true;
        }