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"
	mac := hmac.New(sha256.New, extKey)
	mac.Write([]byte(Context))

	if err != nil {
		return nil, nil, err
	}
	defer f.Close()

	st, err := f.Stat()
	if err != nil {
		return nil, nil, err
	}

	dst := make([]byte, st.Size())
	_, err = io.ReadFull(f, dst)
	return dst, st, err
}

// ReadFile reads the named file and returns the contents.
// A successful call returns err == nil, not err == EOF.

	writer := &parallelWriter{
		writers:     writers,
		writeQuorum: quorum,
		errs:        make([]error, len(writers)),
	}

	for {
		var blocks [][]byte
		n, err := io.ReadFull(src, buf)
		if err != nil {
			if !IsErrIgnored(err, []error{
				io.EOF,
				io.ErrUnexpectedEOF,
			}...) {
				return 0, err
			}
		}

		eof := err == io.EOF || err == io.ErrUnexpectedEOF

	if cap(dst) < skip {
		dst = make([]byte, 0, skip+1024)
	}
	dst = dst[:skip]
	if skip > 0 {
		n, err := io.ReadFull(r.buf, dst)
		if err != nil && err != io.ErrUnexpectedEOF {
			// If an EOF happens after reading some but not all the bytes,
			// ReadFull returns ErrUnexpectedEOF.
			return dst[:n], err
		}
		dst = dst[:n]
		if err == io.ErrUnexpectedEOF {
			return dst, io.EOF
		}
	}

		}
	}
	if offset != b.currOffset {
		// Can never happen unless there are programmer bugs
		return 0, errUnexpected
	}
	b.h.Reset()
	_, err = io.ReadFull(b.rc, b.hashBytes)
	if err != nil {
		return 0, err
	}
	_, err = io.ReadFull(b.rc, buf)
	if err != nil {
		return 0, err
	}
	b.h.Write(buf)
	if !bytes.Equal(b.h.Sum(nil), b.hashBytes) {
		return 0, errFileCorrupt
	}

			asyncWriters <- struct{}{}
			b := poolBuf128k.Get().([]byte)
			if cap(b) < int(header.Size) {
				b = make([]byte, smallFileThreshold)
			}
			b = b[:header.Size]
			if _, err := io.ReadFull(tarReader, b); err != nil {
				return err
			}
			wg.Add(1)
			go func(name string, fi fs.FileInfo, b []byte) {
				rc := disconnectReader{r: bytes.NewReader(b)}
				defer func() {
					rc.Close()

		if err != nil {
			t.Fatalf("Test %d: failed to create ErasureStorage: %v", i, err)
		}
		data := make([]byte, test.size)
		if _, err = io.ReadFull(rand.Reader, data); err != nil {
			t.Fatalf("Test %d: failed to create random test data: %v", i, err)
		}
		buffer := make([]byte, test.blocksize, 2*test.blocksize)
		writers := make([]io.Writer, len(disks))

		return errFileCorrupt
	}

	bufp := xioutil.ODirectPoolSmall.Get().(*[]byte)
	defer xioutil.ODirectPoolSmall.Put(bufp)

	for left > 0 {
		// Read expected hash...
		h.Reset()
		n, err := io.ReadFull(r, hashBuf)
		if err != nil {
			// Read's failed for object with right size, file is corrupt.
			return err
		}
		// Subtract hash length..
		left -= int64(n)
		if left < shardSize {
			shardSize = left