//
// All objects are encrypted with an unique and randomly generated 'ObjectKey'.
// The ObjectKey itself is never stored in plaintext. Instead it is only stored
// in a sealed from. The sealed 'ObjectKey' is created by encrypting the 'ObjectKey'
// with an unique key-encryption-key. Given the correct key-encryption-key the
// sealed 'ObjectKey' can be unsealed and the object can be decrypted.
//
// ## SSE-C
//

	"github.com/minio/sio"
)

// ObjectKey is a 256 bit secret key used to encrypt the object.
// It must never be stored in plaintext.
type ObjectKey [32]byte

// GenerateKey generates a unique ObjectKey from a 256 bit external key
// and a source of randomness. If random is nil the default PRNG of the
// system (crypto/rand) is used.
func GenerateKey(extKey []byte, random io.Reader) (key ObjectKey) {
	if random == nil {

				return crypto.ObjectKey{}, errKMSKeyNotFound
			}
			return crypto.ObjectKey{}, err
		}

		objectKey := crypto.GenerateKey(key.Plaintext, rand.Reader)
		sealedKey = objectKey.Seal(key.Plaintext, crypto.GenerateIV(rand.Reader), crypto.S3KMS.String(), bucket, object)
		crypto.S3KMS.CreateMetadata(metadata, key.KeyID, key.Ciphertext, sealedKey, cryptoCtx)
		return objectKey, nil
	case crypto.SSEC:

	if err != nil {
		return nil, err
	}
	var objectKey crypto.ObjectKey
	if err = objectKey.Unseal(extKey, sealedKey, crypto.S3.String(), bucket, ""); err != nil {
		return nil, err
	}

	outbuf := bytes.NewBuffer(nil)
	_, err = sio.Decrypt(outbuf, bytes.NewBuffer(input), sio.Config{Key: objectKey[:], MinVersion: sio.Version20, CipherSuites: fips.DARECiphers()})
	return outbuf.Bytes(), err

func EncryptMultiPart(r io.Reader, partID int, key ObjectKey) io.Reader {
	partKey := key.DerivePartKey(uint32(partID))
	return EncryptSinglePart(r, ObjectKey(partKey))
}

// DecryptSinglePart decrypts an io.Writer which must an object
// uploaded with the single-part PUT API. The offset and length
// specify the requested range.
func DecryptSinglePart(w io.Writer, offset, length int64, key ObjectKey) io.WriteCloser {

		if err != nil {
			return nil, err
		}
		keys := make([]ObjectKey, len(unsealKeys))
		for i := range keys {
			if err := keys[i].Unseal(unsealKeys[i], sealedKeys[i], s3.String(), buckets[i], objects[i]); err != nil {
				return nil, err
			}
		}
		return keys, nil
	}

	keys := make([]ObjectKey, 0, len(keyIDs))
	for i := range keyIDs {

	}
}

var decryptETagTests = []struct {
	ObjectKey  crypto.ObjectKey
	ObjectInfo ObjectInfo
	ShouldFail bool
	ETag       string
}{
	{
		ObjectKey:  [32]byte{},
		ObjectInfo: ObjectInfo{ETag: "20000f00f27834c9a2654927546df57f9e998187496394d4ee80f3d9978f85f3c7d81f72600cdbe03d80dc5a13d69354"},
		ETag:       "8ad3fe6b84bf38489e95c701c84355b6",
	},
	{
		ObjectKey:  [32]byte{},

func (i *Identifier) String() string {
	if i.Unquoted != nil {
		return *i.Unquoted
	}
	return string(*i.Quoted)
}

func (o *ObjectKey) String() string {
	if o.Lit != nil {
		return fmt.Sprintf("['%s']", string(*o.Lit))
	}
	return fmt.Sprintf(".%s", o.ID.String())
}

func (o *ObjectKey) keyString() string {
	if o.Lit != nil {
		return string(*o.Lit)
	}
	return o.ID.String()
}

	{PartID: 10000, PartKey: "f86e65c396ed52d204ee44bd1a0bbd86eb8b01b7354e67a3b3ae0e34dd5bd115"},
}

func TestDerivePartKey(t *testing.T) {
	var key ObjectKey
	for i, test := range derivePartKeyTest {
		expectedPartKey, err := hex.DecodeString(test.PartKey)
		if err != nil {
			t.Fatalf("Test %d failed to decode expected part-key: %v", i, err)
		}

	// Remove enclosing parenthesis.
	n := len(values[0])
	r := values[0][1 : n-1]
	// Translate doubled quotes
	*ls = LiteralList(strings.Split(r, ","))
	return nil
}

// ObjectKey is a type for parsed strings occurring in key paths
type ObjectKey struct {
	Lit *LiteralString `parser:" \"[\" @LitString \"]\""`
	ID  *Identifier    `parser:"| \".\" @@"`
}

// QuotedIdentifier is a type for parsed strings that are double
// quoted.