1 files changed, 71 insertions, 0 deletions
diff --git a/src/Otp.NET/KeyGeneration.cs b/src/Otp.NET/KeyGeneration.cs
new file mode 100644
index 0000000..7e5b613
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+++ b/src/Otp.NET/KeyGeneration.cs
@@ -0,0 +1,71 @@
+/*
+Credits to Devin Martin and the original OtpSharp library:
+https://bitbucket.org/devinmartin/otp-sharp/overview 
+
+Copyright (C) 2012 Devin Martin
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
+*/
+
+namespace OtpNet
+{
+    /// <summary>
+    /// Helpers to work with keys
+    /// </summary>
+    public static class KeyGeneration
+    {
+        /// <summary>
+        /// Generates a random key in accordance with the RFC recommened length for each algorithm
+        /// </summary>
+        /// <param name="length">Key length</param>
+        /// <returns>The generated key</returns>
+        public static byte[] GenerateRandomKey(int length)
+        {
+            byte[] key = new byte[length];
+            using(var rnd = System.Security.Cryptography.RandomNumberGenerator.Create())
+            {
+                rnd.GetBytes(key);
+                return key;
+            }
+        }
+
+        /// <summary>
+        /// Generates a random key in accordance with the RFC recommened length for each algorithm
+        /// </summary>
+        /// <param name="mode">HashMode</param>
+        /// <returns>Key</returns>
+        public static byte[] GenerateRandomKey(OtpHashMode mode = OtpHashMode.Sha1)
+        {
+            return GenerateRandomKey(LengthForMode(mode));
+        }
+
+        private static int LengthForMode(OtpHashMode mode)
+        {
+            switch(mode)
+            {
+                case OtpHashMode.Sha256:
+                    return 32;
+                case OtpHashMode.Sha512:
+                    return 64;
+                default: //case OtpHashMode.Sha1:
+                    return 20;
+            }
+        }
+    }
+}
+\ No newline at end of file