pkg: move internal/ package to the root directory

This way we can use it in scripts and cli.

internal/random/random_util.go

@@ -0,0 +1,54 @@
+package random
+
+import (
+	"math/rand"
+	"time"
+
+	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+)
+
+// String returns a random string with the n as its length.
+func String(n int) string {
+	b := make([]byte, n)
+	for i := range b {
+		b[i] = byte(Int(65, 90))
+	}
+
+	return string(b)
+}
+
+// Bytes returns a random byte slice of specified length.
+func Bytes(n int) []byte {
+	b := make([]byte, n)
+	Fill(b)
+	return b
+}
+
+// Fill fills buffer with random bytes.
+func Fill(buf []byte) {
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	// Rand reader returns no errors
+	r.Read(buf)
+}
+
+// Int returns a random integer in [min,max).
+func Int(min, max int) int {
+	return min + rand.Intn(max-min)
+}
+
+// Uint256 returns a random Uint256.
+func Uint256() util.Uint256 {
+	str := String(20)
+	return hash.Sha256([]byte(str))
+}
+
+// Uint160 returns a random Uint160.
+func Uint160() util.Uint160 {
+	str := String(20)
+	return hash.RipeMD160([]byte(str))
+}
+
+func init() {
+	rand.Seed(time.Now().UTC().UnixNano())
+}