For regression test, add srs-bench to 3rdparty

trunk/3rdparty/srs-bench/vendor/github.com/pion/randutil/crypto.go

@@ -0,0 +1,30 @@
+package randutil
+
+import (
+	crand "crypto/rand"
+	"encoding/binary"
+	"math/big"
+)
+
+// GenerateCryptoRandomString generates a random string for cryptographic usage.
+func GenerateCryptoRandomString(n int, runes string) (string, error) {
+	letters := []rune(runes)
+	b := make([]rune, n)
+	for i := range b {
+		v, err := crand.Int(crand.Reader, big.NewInt(int64(len(letters))))
+		if err != nil {
+			return "", err
+		}
+		b[i] = letters[v.Int64()]
+	}
+	return string(b), nil
+}
+
+// CryptoUint64 returns cryptographic random uint64.
+func CryptoUint64() (uint64, error) {
+	var v uint64
+	if err := binary.Read(crand.Reader, binary.LittleEndian, &v); err != nil {
+		return 0, err
+	}
+	return v, nil
+}