Add user extensions and encryption modules.

MarketData/MarketDataLib/Extensions/UserExtensions.cs

@@ -0,0 +1,17 @@
+using MarketData.MarketDataModel.User;
+using MarketData.Security;
+
+namespace MarketData.Extensions
+{
+  public static class UserExtensions
+  {
+    public static bool Verify(this User user, string password)
+    {
+      if(null == user || null == user.Username || null == user.Salt || null==user.Hash)
+      {
+        return false;
+      }
+      return Encryption.VerifyPassword(password, user.Salt, user.Hash);
+    }    
+}
+}