// (crypto/rand) is used.
func GenerateIV(random io.Reader) (iv [32]byte) {
	if random == nil {
		random = rand.Reader
	}
	if _, err := io.ReadFull(random, iv[:]); err != nil {
		logger.CriticalIf(context.Background(), errOutOfEntropy)
	}
	return iv
}

// SealedKey represents a sealed object key. It can be stored
// at an untrusted location.
type SealedKey struct {
	Key       [64]byte // The encrypted and authenticated object-key.

		}()
	}
	wg.Wait()
	return newDisks
}

func (er erasureObjects) getOnlineLocalDisks() (newDisks []StorageAPI) {
	disks := er.getOnlineDisks()

	// Based on the random shuffling return back randomized disks.
	r := rand.New(rand.NewSource(time.Now().UnixNano()))

	for _, i := range r.Perm(len(disks)) {
		if disks[i] != nil && disks[i].IsLocal() {
			newDisks = append(newDisks, disks[i])
		}
	}

	}{
		{"shastring", "", "shastring"},
		{emptySHA256, "", emptySHA256},
		{"", "", emptySHA256},
		{"", "X-Amz-Credential=random", unsignedPayload},
		{"", "X-Amz-Credential=random&X-Amz-Content-Sha256=" + unsignedPayload, unsignedPayload},
		{"", "X-Amz-Credential=random&X-Amz-Content-Sha256=shastring", "shastring"},
	}

	for i, testCase := range testCases {

	letterIdxMax  = 63 / letterIdxBits   // # of letter indices fitting in 63 bits
)

// Random number state.
// We generate random temporary file names so that there's a good
// chance the file doesn't exist yet.
var (
	randN  uint32
	randmu sync.Mutex
)

// Temp files created in default Tmp dir
var globalTestTmpDir = os.TempDir()

	if w == 0 {
		return true
	}

	return false
}

// mustGetUUID - get a random UUID.
func mustGetUUID() string {
	u, err := uuid.NewRandom()
	if err != nil {
		logger.CriticalIf(GlobalContext, err)
	}

	return u.String()
}

// mustGetUUIDBytes - get a random UUID as 16 bytes unencoded.
func mustGetUUIDBytes() []byte {
	u, err := uuid.NewRandom()
	if err != nil {

	// FileNameFunc must ensure collisions in filenames do not occur.
	// Do not rely on timestamps to be unique, high throughput writes
	// may fall on the same timestamp.
	// Eg.
	// 	2020-03-28_15-00-945-<random-hash>.log
	// When FileNameFunc is not specified, DefaultFilenameFunc will be used.
	FileNameFunc func() string

	// Compress specify if you want the logs to be compressed after rotation.
	Compress bool
}

	errInvalidInternalSealAlgorithm = Errorf("The internal seal algorithm is invalid and not supported")
)

// errOutOfEntropy indicates that the a source of randomness (PRNG) wasn't able
// to produce enough random data. This is fatal error and should cause a panic.

func exponentialBackoffWait(r *rand.Rand, unit, cap time.Duration) func(uint) time.Duration {
	if unit > time.Hour {
		// Protect against integer overflow
		panic("unit cannot exceed one hour")
	}
	return func(attempt uint) time.Duration {
		if attempt > 16 {
			// Protect against integer overflow
			attempt = 16
		}
		// sleep = random_between(unit, min(cap, base * 2 ** attempt))

func testPostPolicyBucketHandler(obj ObjectLayer, instanceType string, t TestErrHandler) {
	if err := newTestConfig(globalMinioDefaultRegion, obj); err != nil {
		t.Fatalf("Initializing config.json failed")
	}

	// get random bucket name.
	bucketName := getRandomBucketName()

	var opts ObjectOptions
	// Register the API end points with Erasure/FS object layer.
	apiRouter := initTestAPIEndPoints(obj, []string{"PostPolicy"})

// Trivial collisions are avoided, but this is by no means a strong hash.
func hashDeterministicString(m map[string]string) uint64 {
	// Seed (random)
	crc := uint64(0xc2b40bbac11a7295)
	// Xor each value to make order independent
	for k, v := range m {
		// Separate key and value with an individual xor with a random number.
		// Add values of each, so they cannot be trivially collided.