src := []byte("hello, world")
	dst := make([]byte, len(src))
	rb := bytes.NewBuffer(src)
	wb := new(bytes.Buffer)
	r := TeeReader(rb, wb)
	if n, err := ReadFull(r, dst); err != nil || n != len(src) {
		t.Fatalf("ReadFull(r, dst) = %d, %v; want %d, nil", n, err, len(src))
	}
	if !bytes.Equal(dst, src) {
		t.Errorf("bytes read = %q want %q", dst, src)
	}
	if !bytes.Equal(wb.Bytes(), src) {

	}
	if length <= 0 {
		length = accessKeyMaxLen
	}
	if length < accessKeyMinLen {
		return "", errors.New("auth: access key length is too short")
	}

	key := make([]byte, length)
	if _, err := io.ReadFull(random, key); err != nil {
		return "", err
	}
	for i := range key {
		key[i] = alphaNumericTable[key[i]%alphaNumericTableLen]
	}
	return string(key), nil
}

func (tr *Reader) readHeader() (*Header, *block, error) {
	// Two blocks of zero bytes marks the end of the archive.
	if _, err := io.ReadFull(tr.r, tr.blk[:]); err != nil {
		return nil, nil, err // EOF is okay here; exactly 0 bytes read
	}
	if bytes.Equal(tr.blk[:], zeroBlock[:]) {
		if _, err := io.ReadFull(tr.r, tr.blk[:]); err != nil {
			return nil, nil, err // EOF is okay here; exactly 1 block of zeros read
		}

	x = Element{1, 1, 1, 1, 1}
	x2.Multiply(&x, &x)
	x2sq.Square(&x)

	if x2 != x2sq {
		t.Fatalf("all ones failed\nmul: %x\nsqr: %x\n", x2, x2sq)
	}

	var bytes [32]byte

	_, err := io.ReadFull(rand.Reader, bytes[:])
	if err != nil {
		t.Fatal(err)
	}
	x.SetBytes(bytes[:])

	x2.Multiply(&x, &x)
	x2sq.Square(&x)

	if x2 != x2sq {

	}
	res, err := http.ReadResponse(bufio.NewReader(conn), req)
	if err != nil {
		t.Fatalf("ReadResponse: %v", err)
	}
	defer res.Body.Close()
	var buf [5000]byte
	n, err := io.ReadFull(res.Body, buf[:])
	if err != nil {
		t.Fatalf("ReadFull: %d bytes, %v", n, err)
	}

	if !handlerRunning() {
		t.Fatalf("pre-conn.Close, expected handler to still be running")
	}
	conn.Close()
	closed := time.Now()

	// indicates a possible race with someone editing the file, so we prefer to
	// stop to avoid corrupting it.)
	src := make([]byte, size+1)
	n, err := io.ReadFull(in, src)
	switch err {
	case nil, io.EOF, io.ErrUnexpectedEOF:
		// io.ReadFull returns io.EOF (for an empty file) or io.ErrUnexpectedEOF
		// (for a non-empty file) if the file was changed unexpectedly. Continue
		// with comparing file sizes in those cases.

	var wg sync.WaitGroup
	defer wg.Wait()

	pingPonger := func(c net.Conn) {
		defer wg.Done()
		buf := make([]byte, 8)
		var prev uint64
		for {
			if _, err := io.ReadFull(c, buf); err != nil {
				if err == io.EOF {
					break
				}
				t.Errorf("unexpected Read error: %v", err)
			}

			v := binary.LittleEndian.Uint64(buf)
			binary.LittleEndian.PutUint64(buf, v+1)

// nonZeroRandomBytes fills the given slice with non-zero random octets.
func nonZeroRandomBytes(s []byte, random io.Reader) (err error) {
	_, err = io.ReadFull(random, s)
	if err != nil {
		return
	}

	for i := 0; i < len(s); i++ {
		for s[i] == 0 {
			_, err = io.ReadFull(random, s[i:i+1])
			if err != nil {
				return
			}
			// In tests, the PRNG may return all zeros so we do
			// this to break the loop.

	return c.Reader.(WriterTo).WriteTo(w)
}

// ReadAll reads from r until an error or EOF and returns the data it read.
// A successful call returns err == nil, not err == EOF. Because ReadAll is
// defined to read from src until EOF, it does not treat an EOF from Read
// as an error to be reported.
func ReadAll(r Reader) ([]byte, error) {
	b := make([]byte, 0, 512)
	for {

		// we're attempting TLS 1.2.
		if maxVersion < VersionTLS12 && suite.flags&suiteTLS12 != 0 {
			continue
		}
		hello.cipherSuites = append(hello.cipherSuites, suiteId)
	}

	_, err := io.ReadFull(config.rand(), hello.random)
	if err != nil {
		return nil, nil, nil, errors.New("tls: short read from Rand: " + err.Error())
	}

	// A random session ID is used to detect when the server accepted a ticket