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))

        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

            }

            if ( ctx.isEstablished() ) {
                log.debug("Context is established");
                setNetbiosName(ctx.getNetbiosName());
                byte[] sk = ctx.getSigningKey();
                if ( sk != null ) {
                    // session key is truncated to 16 bytes, right padded with 0 if shorter
                    byte[] key = new byte[16];

/**
 * @author mbechler
 *
 */
public interface SSPContext {

    /**
     * @return the signing key for the session
     * 
     * @throws CIFSException
     */
    byte[] getSigningKey () throws CIFSException;


    /**
     * @return whether the context is established
     */
    boolean isEstablished ();


    /**
     * @param token
     * @param off
     * @param len

                            } else {
                                byte[] signingKey = auth.getSigningKey(transport.server.encryptionKey);
                                request.digest = new SigningDigest(signingKey, false);
                            }
                        }
    

     */
    @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

        return ret;
    }

    public boolean isEstablished() {
        return isEstablished;
    }
    public byte[] getServerChallenge()
    {
        return serverChallenge;
    }
    public byte[] getSigningKey()
    {
        return signingKey;
    }
    public String getNetbiosName()
    {
        return netbiosName;
    }

    private String getNtlmsspListItem(byte[] type2token, int id0)
    {

		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.

        }
    }


    /**
     * @param tc
     * @param chlng
     * @return the signing key
     * @throws SmbException
     * @throws GeneralSecurityException
     */
    public byte[] getSigningKey ( CIFSContext tc, byte[] chlng ) throws SmbException, GeneralSecurityException {
        switch ( tc.getConfig().getLanManCompatibility() ) {
        case 0:
        case 1:
        case 2: