Vendor in latest containers/storage

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

vendor/github.com/containers/storage/pkg/stringid/stringid.go

@@ -12,6 +12,7 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 )
 
@@ -20,6 +21,9 @@ const shortLen = 12
 var (
 	validShortID = regexp.MustCompile("^[a-f0-9]{12}$")
 	validHex     = regexp.MustCompile(`^[a-f0-9]{64}$`)
+
+	rngLock sync.Mutex
+	rng     *rand.Rand // A RNG with seeding properties we control. It can only be accessed with randLock held.
 )
 
 // IsShortID determines if an arbitrary string *looks like* a short ID.
@@ -67,7 +71,9 @@ func GenerateRandomID() string {
 // secure sources of random.
 // It helps you to save entropy.
 func GenerateNonCryptoID() string {
-	return generateID(readerFunc(rand.Read))
+	rngLock.Lock()
+	defer rngLock.Unlock()
+	return generateID(readerFunc(rng.Read))
 }
 
 // ValidateID checks whether an ID string is a valid image ID.
@@ -79,7 +85,7 @@ func ValidateID(id string) error {
 }
 
 func init() {
-	// safely set the seed globally so we generate random ids. Tries to use a
+	// Initialize a private RNG so we generate random ids. Tries to use a
 	// crypto seed before falling back to time.
 	var seed int64
 	if cryptoseed, err := cryptorand.Int(cryptorand.Reader, big.NewInt(math.MaxInt64)); err != nil {
@@ -89,7 +95,7 @@ func init() {
 		seed = cryptoseed.Int64()
 	}
 
-	rand.Seed(seed)
+	rng = rand.New(rand.NewSource(seed))
 }
 
 type readerFunc func(p []byte) (int, error)