}

		start, length, err1 := rs.GetOffsetLength(objectSize)
		if err1 != nil {
			t.Fatalf("expected: <nil>, got: %s", err1)
		}

		if start != successCase.offsetBegin {
			t.Fatalf("expected: %d, got: %d", successCase.offsetBegin, start)
		}

		if start+length-1 != successCase.offsetEnd {
			t.Fatalf("expected: %d, got: %d", successCase.offsetEnd, start+length-1)
		}
	}

		s           string
		startIdx    int
		length      int
		resExpected string
		errExpected error
	}{
		{"abcd", 1, 1, "a", nil},
		{"abcd", -1, 1, "a", nil},
		{"abcd", 999, 999, "", nil},
		{"", 999, 999, "", nil},
		{"测试abc", 1, 1, "测", nil},
		{"测试abc", 5, 5, "c", nil},
	}

	for i, tc := range evalCases {
		res, err := evalSQLSubstring(tc.s, tc.startIdx, tc.length)
		if res != tc.resExpected || err != tc.errExpected {

	var n int
	switch {
	case f.Header.Length <= len7:
		bts[1] = byte(f.Header.Length)
		n = 2

	case f.Header.Length <= len16:
		bts[1] = 126
		binary.BigEndian.PutUint16(bts[2:4], uint16(f.Header.Length))
		n = 4

	case f.Header.Length <= len64:
		bts[1] = 127
		binary.BigEndian.PutUint64(bts[2:10], uint64(f.Header.Length))
		n = 10

	default:

	return ct.AutoIncrementValue.Bool, ct.AutoIncrementValue.Valid
}

// Length returns the column type length for variable length column types
func (ct ColumnType) Length() (length int64, ok bool) {
	if ct.LengthValue.Valid {
		return ct.LengthValue.Int64, true
	}
	return ct.SQLColumnType.Length()
}

// DecimalSize returns the scale and precision of a decimal type.

	for len(b) > 0 {
		t, n := binary.Uvarint(b)
		if n < 0 {
			break
		}
		b = b[n:]

		typ := ChecksumType(t)
		length := typ.RawByteLen()
		if length == 0 || len(b) < length {
			break
		}
		cs := base64.StdEncoding.EncodeToString(b[:length])
		b = b[length:]
		if typ.Is(ChecksumMultipart) {
			t, n := binary.Uvarint(b)
			if n < 0 {
				break
			}
			cs = fmt.Sprintf("%s-%d", cs, t)

// 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 {
	const PayloadSize = 1 << 16 // DARE 2.0
	w = ioutil.LimitedWriter(w, offset%PayloadSize, length)

	decWriter, err := sio.DecryptWriter(w, sio.Config{Key: key[:], CipherSuites: fips.DARECiphers()})

}

func evalSQLSubstring(s string, startIdx, length int) (res string, err error) {
	rs := []rune(s)

	// According to s3 document, if startIdx < 1, it is set to 1.
	if startIdx < 1 {
		startIdx = 1
	}

	if startIdx > len(rs) {
		startIdx = len(rs) + 1
	}

	// StartIdx is 1-based in the input
	startIdx--
	endIdx := len(rs)
	if length != -1 {
		if length < 0 {
			return "", errInvalidSubstringIndexLen

}

// FIXME: add support for remote version ID in Azure remote tier and remove
// this. Currently it's a no-op.

func (az *warmBackendAzure) Put(ctx context.Context, object string, r io.Reader, length int64) (remoteVersionID, error) {
	blobURL := az.serviceURL.NewContainerURL(az.Bucket).NewBlockBlobURL(az.getDest(object))
	// set tier if specified -
	if az.StorageClass != "" {

func GenerateKey(extKey []byte, random io.Reader) (key ObjectKey) {
	if random == nil {
		random = rand.Reader
	}
	if len(extKey) != 32 { // safety check
		logger.CriticalIf(context.Background(), errors.New("crypto: invalid key length"))
	}
	var nonce [32]byte
	if _, err := io.ReadFull(random, nonce[:]); err != nil {
		logger.CriticalIf(context.Background(), errOutOfEntropy)
	}

	const Context = "object-encryption-key generation"

		if name == s {
			return alg
		}
	}
	return
}

func newBitrotWriter(disk StorageAPI, origvolume, volume, filePath string, length int64, algo BitrotAlgorithm, shardSize int64) io.Writer {
	if algo == HighwayHash256S {
		return newStreamingBitrotWriter(disk, origvolume, volume, filePath, length, algo, shardSize)
	}
	return newWholeBitrotWriter(disk, volume, filePath, algo, shardSize)
}