From be0b402a1fa276f9b614a394caa94c9010e04789 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zolt=C3=A1n=20M=C3=A1t=C3=A9?= <zoltan.mate@lombiq.com>
Date: Sun, 15 Oct 2023 23:37:34 +0200
Subject: [PATCH] Adding GenerateRandomPassword helper

---
 .../Users/PasswordHelper.cs                   | 40 +++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 Lombiq.HelpfulLibraries.OrchardCore/Users/PasswordHelper.cs

diff --git a/Lombiq.HelpfulLibraries.OrchardCore/Users/PasswordHelper.cs b/Lombiq.HelpfulLibraries.OrchardCore/Users/PasswordHelper.cs
new file mode 100644
index 00000000..ae03dd98
--- /dev/null
+++ b/Lombiq.HelpfulLibraries.OrchardCore/Users/PasswordHelper.cs
@@ -0,0 +1,40 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Security.Cryptography;
+
+namespace Lombiq.HelpfulLibraries.OrchardCore.Users;
+
+public static class PasswordHelper
+{
+    /// <summary>
+    /// Generates a <paramref name="minLength"/> long random password.
+    /// </summary>
+    public static string GenerateRandomPassword(int minLength)
+    {
+        const string validChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*()_+-="; // #spell-check-ignore-line
+
+        using var rng = RandomNumberGenerator.Create();
+        const string digits = "0123456789";
+        const string lowerChars = "abcdefghijklmnopqrstuvwxyz"; // #spell-check-ignore-line
+        const string upperChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; // #spell-check-ignore-line
+        const string specialChars = "!@#$%^&*()_+-=";
+
+        var passwordChars = new List<char>
+            {
+                digits[rng.Next(0, digits.Length)],
+                lowerChars[rng.Next(0, lowerChars.Length)],
+                upperChars[rng.Next(0, upperChars.Length)],
+                specialChars[rng.Next(0, specialChars.Length)],
+            };
+
+        while (passwordChars.Count < minLength)
+        {
+            passwordChars.Add(validChars[rng.Next(0, validChars.Length)]);
+        }
+
+        passwordChars = passwordChars.OrderBy(c => rng.Next(0, int.MaxValue)).ToList();
+        string password = new(passwordChars.ToArray());
+
+        return password;
+    }
+}