//     Input: ClientKey, bucket, object, metadata, object_data
//     -              IV := Random({0,1}²⁵⁶)
//     -       ObjectKey := SHA256(ClientKey || Random({0,1}²⁵⁶))
//     -       KeyEncKey := HMAC-SHA256(ClientKey, IV || 'SSE-C' || 'DAREv2-HMAC-SHA256' || bucket || '/' || object)
//     -       SealedKey := DAREv2_Enc(KeyEncKey, ObjectKey)
//     - enc_object_data := DAREv2_Enc(ObjectKey, object_data)
//     -        metadata <- IV

 * supporting various checksum algorithms including HMAC-MD5 and HMAC-SHA1 with AES.
 */
public class PacSignature {

    /**
     * Kerberos checksum type for HMAC-MD5 (ARCFOUR-HMAC).
     */
    public static final int KERB_CHECKSUM_HMAC_MD5 = 0xFFFFFF76;
    /**
     * Kerberos checksum type for HMAC-SHA1-96 with AES-128.
     */
    public static final int HMAC_SHA1_96_AES128 = 0x0000000F;

 * ARCFOUR-HMAC-MD5 and AES-based HMAC algorithms.
 */
public class PacMac {

    /**
     * Private constructor to prevent instantiation of utility class.
     */
    private PacMac() {
        // Utility class
    }

    /**
     *
     */
    private static final String HMAC_KEY = "HMAC";

//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package crypto

import (
	"bytes"
	"context"
	"crypto/hmac"
	"crypto/rand"
	"encoding/binary"
	"errors"
	"io"
	"path"

	"github.com/minio/minio/internal/hash/sha256"
	"github.com/minio/minio/internal/logger"
	"github.com/minio/sio"
)

            throw new IllegalStateException(ex.getMessage());
        }
        engineReset();
    }

    private HMACT64(final HMACT64 hmac) throws CloneNotSupportedException {
        super("HMACT64");
        this.ipad = hmac.ipad;
        this.opad = hmac.opad;
        this.md5 = (MessageDigest) hmac.md5.clone();
    }

    @Override
    public Object clone() {
        try {
            return new HMACT64(this);

        }

        this.md5 = Crypto.getMD5();
        engineReset();
    }

    private HMACT64(final HMACT64 hmac) throws CloneNotSupportedException {
        super("HMACT64");
        this.ipad = hmac.ipad;
        this.opad = hmac.opad;
        this.md5 = (MessageDigest) hmac.md5.clone();
    }

    @Override
    public Object clone() {
        try {
            return new HMACT64(this);

This is based on RFC 4253, section 6.4, but with hmac-md5 variants removed because they have 
reached the end of their useful life.

Valid values: 

```
hmac******@****.***
hmac******@****.***
hmac-sha2-256
hmac-sha2-512
hmac-sha1
hmac-sha1-96
```

### Certificate-based authentication

	if err != nil {
		return nil, ErrDecrypt
	}
	return plaintext, nil
}

// MAC generate hmac for the request
func (s secretKey) MAC(_ context.Context, req *MACRequest) ([]byte, error) {
	mac := hmac.New(sha256.New, s.key)
	mac.Write(req.Message)
	return mac.Sum(make([]byte, 0, mac.Size())), nil
}

// parseCiphertext parses and converts a ciphertext into

			"X-Minio-Internal-Server-Side-Encryption-Sealed-Key":     "IAAfAMBdYor5tf/UlVaQvwYlw5yKbPBeQqfygqsfHqhu1wHD9KDAP4bw38AhL12prFTS23JbbR9Re5Qv26ZnlQ==",
			"X-Minio-Internal-Server-Side-Encryption-Seal-Algorithm": "DAREv2-HMAC-SHA256",
			"X-Minio-Internal-Server-Side-Encryption-Iv":             "coVfGS3I/CTrqexX5vUN+PQPoP9aUFiPYYrSzqTWfBA=",
		},
		ExpectedErr: nil,
	},
	{ // 1 - Valid HTTP headers but invalid metadata entries for bucket/object2

    }

    @Test
    @DisplayName("Should calculate HMAC-T64 correctly")
    void testHMACT64() {
        // Given
        byte[] key = "secret".getBytes();
        byte[] data = "Hello World".getBytes();

        // When
        MessageDigest hmac = Crypto.getHMACT64(key);
        byte[] result = hmac.digest(data);

        // Then
        assertNotNull(result);