From d65c22fe116931bb231b4d13e18c1f451d6af7a1 Mon Sep 17 00:00:00 2001
From: Mattia Cabrini <dev@mattiacabrini.com>
Date: Wed, 23 Apr 2025 18:11:33 +0200
Subject: [PATCH] +RandString

---
 rand_string.go | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 rand_string.go

diff --git a/rand_string.go b/rand_string.go
new file mode 100644
index 0000000..597aaeb
--- /dev/null
+++ b/rand_string.go
@@ -0,0 +1,40 @@
+// Copyright (c) 2023 Mattia Cabrini
+// SPDX-License-Identifier: MIT
+
+package utility
+
+import (
+	"crypto/rand"
+	"fmt"
+)
+
+func RandString(n int) (string, error) {
+	if n <= 0 {
+		return "", fmt.Errorf("lunghezza non valida: %d", n)
+	}
+
+	const charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+	const mask = 63
+	const maxByte = 255 - (255 % len(charset))
+
+	b := make([]byte, n)
+	i := 0
+	for i < n {
+		buf := make([]byte, 1)
+		if _, err := rand.Read(buf); err != nil {
+			return "", AppendError(err)
+		}
+
+		if int(buf[0]) > maxByte {
+			continue
+		}
+
+		idx := int(buf[0] & mask)
+		if idx < len(charset) {
+			b[i] = charset[idx]
+			i++
+		}
+	}
+
+	return string(b), nil
+}
-- 
2.43.0