class InvalidInputs {
        @Test
        @DisplayName("getSigningKey throws when unavailable")
        void testGetSigningKeyThrows() {
            DummySSPContext ctx = new DummySSPContext(null, false, null, null, 0, false);
            CIFSException ex = assertThrows(CIFSException.class, ctx::getSigningKey);
            assertTrue(ex.getMessage().contains("signing key"));
        }

        @Test

	canonicalRequestBytes := sha256.Sum256([]byte(canonicalRequest))
	stringToSign += hex.EncodeToString(canonicalRequestBytes[:])
	return stringToSign
}

// getSigningKey hmac seed to calculate final signature.
func getSigningKey(secretKey string, t time.Time, region string, stype serviceType) []byte {
	date := sumHMAC([]byte("AWS4"+secretKey), []byte(t.Format(yyyymmdd)))
	regionBytes := sumHMAC(date, []byte(region))

    public String getNetbiosName() {
        return null;
    }

    /**
     * {@inheritDoc}
     *
     * @see jcifs.smb.SSPContext#getSigningKey()
     */
    @Override
    public byte[] getSigningKey() throws CIFSException {
        return this.mechContext.getSigningKey();
    }

    /**
     * Initialize the GSSContext to provide SPNEGO feature.
     *
     * @param inputBuf
     * @param offset

     */
    @Override
    public String getNetbiosName() {
        return null;
    }

    /**
     * {@inheritDoc}
     *
     * @see jcifs.smb.SSPContext#getSigningKey()
     */
    @Override
    public byte[] getSigningKey() throws SmbException {
        /*
         * The kerberos session key is not accessible via the JGSS API. IBM and
         * Oracle both implement a similar API to make an ExtendedGSSContext

		cr.seedDate.Format(iso8601Format) + "\n" +
		getScope(cr.seedDate, cr.region) + "\n" +
		cr.seedSignature + "\n" +
		emptySHA256 + "\n" +
		hashedChunk

	// Get hmac signing key.
	signingKey := getSigningKey(cr.cred.SecretKey, cr.seedDate, cr.region, serviceS3)

	// Calculate signature.
	newSignature := getSignature(signingKey, stringToSign)

	return newSignature
}

					fmt.Sprintf(credentialTemplate, accessKey, now.Format(yyyymmdd), globalMinioDefaultRegion),
				},
				"X-Amz-Date": []string{now.Format(iso8601Format)},
				"X-Amz-Signature": []string{
					getSignature(getSigningKey(globalActiveCred.SecretKey, now,
						globalMinioDefaultRegion, serviceS3), "policy"),
				},
				"Policy": []string{"policy"},
			},
			expected: ErrNone,
		},
	}

	// Run each test case individually.

    void getNetbiosName_null() {
        assertNull(ctx.getNetbiosName());
    }

    @Test
    @DisplayName("getSigningKey throws when ExtendedGSSContext not implemented")
    void getSigningKey_notImplementedByGSSContext() {
        SmbException ex = assertThrows(SmbException.class, () -> ctx.getSigningKey());
        assertTrue(ex.getMessage().contains("ExtendedGSSContext is not implemented"));
    }

    @Test

     * @return the server's challenge
     */
    public byte[] getServerChallenge() {
        return this.serverChallenge;
    }

    @Override
    public byte[] getSigningKey() {
        return this.masterKey;
    }

    @Override
    public String getNetbiosName() {
        return this.netbiosName;
    }

    /**

     * @param chlng the server challenge
     * @return the signing key
     * @throws SmbException if an SMB error occurs
     * @throws GeneralSecurityException if a security error occurs
     */
    public byte[] getSigningKey(CIFSContext tc, byte[] chlng) throws SmbException, GeneralSecurityException {
        switch (tc.getConfig().getLanManCompatibility()) {
        case 0:
        case 1:
        case 2:

     *
     * @param challenge the server challenge bytes
     * @return the signing key
     * @throws SmbException if an error occurs generating the signing key
     */
    public byte[] getSigningKey(final byte[] challenge) throws SmbException {
        switch (LM_COMPATIBILITY) {
        case 0:
        case 1:
        case 2:
            final byte[] signingKey = new byte[40];