feat: add KeyGenerators class to enable users generate IV key and secret

Author: selfmadecode

src/Helpers/KeyGenerators.cs

@@ -0,0 +1,55 @@
+using System;
+using System.Collections.Generic;
+using System.Security.Cryptography;
+using System.Text;
+
+namespace SafeCrypt.src.Helpers
+{
+    public class KeyGenerators
+    {
+
+        /// <summary>
+        /// Generates an array of random bytes using a cryptographically secure random number generator.
+        /// </summary>
+        /// <param name="length">The length of the byte array to generate.</param>
+        /// <returns>An array of random bytes or the IV key</returns>
+        /// <remarks>
+        /// The method uses a cryptographically secure random number generator (RNGCryptoServiceProvider) to generate
+        /// a byte array with the specified length, providing a high level of randomness suitable for cryptographic use.
+        /// </remarks>
+        /// <param name="length">The desired length of the generated byte array.</param>
+        /// <returns>An array of random bytes with the specified length.</returns>
+        /// <exception cref="ArgumentException">
+        /// Thrown if the specified length is less than or equal to zero.
+        /// </exception>
+        public static byte[] GenerateRandomIVKeyAsBytes(int length)
+        {
+            byte[] randomBytes = new byte[length];
+            using (RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider())
+            {
+                rng.GetBytes(randomBytes);
+            }
+            return randomBytes;
+        }
+
+        /// <summary>
+        /// Generates a valid AES secret key with the specified key size.
+        /// </summary>
+        /// <param name="keySize">The desired key size (128, 192, or 256 bits).</param>
+        /// <returns>A valid AES secret key as a byte array.</returns>
+        public static string GenerateAesSecretKey(int keySize)
+        {
+            if (keySize != 128 && keySize != 192 && keySize != 256)
+            {
+                throw new ArgumentException("Invalid key size. Supported sizes are 128, 192, or 256 bits.", nameof(keySize));
+            }
+
+            using (Aes aesAlg = Aes.Create())
+            {
+                aesAlg.KeySize = keySize;
+                aesAlg.GenerateKey();
+                return Convert.ToBase64String(aesAlg.Key);
+            }
+        }
+    }
+}