docs/geode-native-docs/security/authentication.html.md.erb

---
title:  Authentication
---

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A client is authenticated when it connects, with valid credentials, to a <%=vars.product_name%> cache server that is configured with the client `Authenticator` callback.

Examples of various implementations can be found in the Native Client source distribution's `../templates/security`` directory.

An `AuthenticationRequiredException` is thrown when the server is configured with security and the
client does not present its credentials while attempting to connect.

The following excerpts are taken from the .NET example provided with your Native Client distribution in the `../examples/dotnet/AuthInitialize` directory.

```cs
using System;
using Apache.Geode.Client;

namespace Apache.Geode.Examples.AuthInitialize
{
  class Program
  {
    static void Main(string[] args)
    {
      var cacheFactory = new CacheFactory()
          .Set("log-level", "none")
          .SetAuthInitialize(new ExampleAuthInitialize());

      var cache = cacheFactory.Create();
      var poolFactory = cache.GetPoolFactory()
          .AddLocator("localhost", 10334);
      poolFactory.Create("pool");
      var regionFactory = cache.CreateRegionFactory(RegionShortcut.PROXY)
          .SetPoolName("pool");
      var region = regionFactory.Create<string, string>("region");

      region["a"] = "1";
      region["b"] = "2";

      var a = region["a"];
      var b = region["b"];

      Console.Out.WriteLine("a = " + a);
      Console.Out.WriteLine("b = " + b);

      cache.Close();
    }
  }

  class ExampleAuthInitialize : IAuthInitialize
  {
    public ExampleAuthInitialize()
    {
        // TODO initialize your resources here
        Console.Out.WriteLine("ExampleAuthInitialize::ExampleAuthInitialize called");
    }

    public void Close()
    {
        // TODO close your resources here
        Console.Out.WriteLine("ExampleAuthInitialize::Close called");
    }

    public Properties<string, object> GetCredentials(Properties<string, string> props, string server)
    {
        // TODO get your username and password
        Console.Out.WriteLine("ExampleAuthInitialize::GetCredentials called");

        var credentials = new Properties<string, object>();
        credentials.Insert("username", "john");
        credentials.Insert("password", "secret");
        return credentials;
    }
  }
}

```