add GenerateBase64IVKey method

Author: selfmadecode

src/SafeCrypt.Lib/Helpers/KeyGenerators.cs

@@ -42,12 +42,18 @@ public static byte[] GenerateRandomIVKeyAsBytes(int length)
         /// <see cref="BitConverter.ToString"/>. Any hyphens in the resulting string are removed
         /// using <see cref="string.Replace"/>.
         /// </remarks>
-        public static string GenerateRandomIVKeyAsString()
+        public static string GenerateHexadecimalIVKey()
         {
             byte[] randomBytes = GenerateRandomIVKeyAsBytes(16);            
             return BitConverter.ToString(randomBytes).Replace("-", "");
         }
 
+        public static string GenerateBase64IVKey()
+        {
+            byte[] randomBytes = GenerateRandomIVKeyAsBytes(16);
+            return Convert.ToBase64String(randomBytes);
+        }
+
         /// <summary>
         /// Generates a valid AES secret key with the specified key size.
         /// </summary>