/// <summary>
 /// Constructs AmazonSecurityTokenServiceClient with AWS Access Key ID, AWS Secret Key and an
 /// AmazonSecurityTokenServiceClient Configuration object. 
 /// </summary>
 /// <param name="awsAccessKeyId">AWS Access Key ID</param>
 /// <param name="awsSecretAccessKey">AWS Secret Access Key</param>
 /// <param name="awsSessionToken">AWS Session Token</param>
 /// <param name="clientConfig">The AmazonSecurityTokenServiceClient Configuration Object</param>
 public AmazonSecurityTokenServiceClient(string awsAccessKeyId, string awsSecretAccessKey, string awsSessionToken, AmazonSecurityTokenServiceConfig clientConfig)
     : base(awsAccessKeyId, awsSecretAccessKey, awsSessionToken, clientConfig)
 {
 }

 /// <summary>
 /// Create a client for the Amazon SecurityTokenService Service with the specified configuration
 /// </summary>
 /// <param name="awsAccessKey">The AWS Access Key associated with the account</param>
 /// <param name="awsSecretAccessKey">The AWS Secret Access Key associated with the account</param>
 /// <param name="config">Configuration options for the service like HTTP Proxy, # of connections, etc
 /// </param>
 /// <returns>An Amazon SecurityTokenService client</returns>
 /// <remarks>
 /// </remarks>
 public static IAmazonSecurityTokenService CreateAmazonSecurityTokenServiceClient(
     string awsAccessKey,
     string awsSecretAccessKey, AmazonSecurityTokenServiceConfig config
     )
 {
     return new AmazonSecurityTokenServiceClient(awsAccessKey, awsSecretAccessKey, config);
 }

 /// <summary>
 /// Constructs AmazonSecurityTokenServiceClient with the credentials defined in the App.config.
 /// 
 /// Example App.config with credentials set. 
 /// <code>
 /// &lt;?xml version="1.0" encoding="utf-8" ?&gt;
 /// &lt;configuration&gt;
 ///     &lt;appSettings&gt;
 ///         &lt;add key="AWSAccessKey" value="********************"/&gt;
 ///         &lt;add key="AWSSecretKey" value="****************************************"/&gt;
 ///     &lt;/appSettings&gt;
 /// &lt;/configuration&gt;
 /// </code>
 ///
 /// </summary>
 /// <param name="config">The AmazonSecurityTokenService Configuration Object</param>
 public AmazonSecurityTokenServiceClient(AmazonSecurityTokenServiceConfig config)
     : base(new EnvironmentAWSCredentials(), config, true, AuthenticationTypes.User)
 {
 }

 /// <summary>
 /// Create a client for the Amazon SecurityToken Service with the credentials loaded from the application's
 /// default configuration, and if unsuccessful from the Instance Profile service on an EC2 instance.
 /// 
 /// Example App.config with credentials set. 
 /// <code>
 /// &lt;?xml version="1.0" encoding="utf-8" ?&gt;
 /// &lt;configuration&gt;
 ///     &lt;appSettings&gt;
 ///         &lt;add key="AWSAccessKey" value="********************"/&gt;
 ///         &lt;add key="AWSSecretKey" value="****************************************"/&gt;
 ///     &lt;/appSettings&gt;
 /// &lt;/configuration&gt;
 /// </code>
 /// </summary>
 /// <param name="config">Configuration options for the service like HTTP Proxy, # of connections, etc</param>
 /// <returns>An Amazon SecurityTokenService client</returns>
 public static AmazonSecurityTokenService CreateAmazonSecurityTokenServiceClient(AmazonSecurityTokenServiceConfig config)
 {
     return new AmazonSecurityTokenServiceClient(config);
 }

 /// <summary>
 /// Constructs a RefreshingSessionAWSCredentials object.
 /// AccessKey and SecretKey are taken from the app.config for the application.
 /// 
 /// Example App.config with credentials set. 
 /// <code>
 /// &lt;?xml version="1.0" encoding="utf-8" ?&gt;
 /// &lt;configuration&gt;
 ///     &lt;appSettings&gt;
 ///         &lt;add key="AWSAccessKey" value="********************"/&gt;
 ///         &lt;add key="AWSSecretKey" value="****************************************"/&gt;
 ///     &lt;/appSettings&gt;
 /// &lt;/configuration&gt;
 /// </code>
 /// </summary>
 /// <param name="stsConfig">Config object used for the constructed AmazonSecurityTokenService.</param>
 public RefreshingSessionAWSCredentials(AmazonSecurityTokenServiceConfig stsConfig)
     : this(new EnvironmentAWSCredentials(), stsConfig)
 {
 }

        private static AmazonSecurityTokenService ConstructSTSClient(AWSCredentials credentials, AmazonSecurityTokenServiceConfig config)
        {
            using (ImmutableCredentials immmutableCredentials = credentials.GetCredentials())
            {
                if (immmutableCredentials.UseToken)
                    throw new ArgumentException("Session credentials cannot be used to create refreshing session credentials");

                AmazonSecurityTokenServiceClient stsClient;
                if (immmutableCredentials.UseSecureStringForSecretKey)
                {
                    stsClient = new AmazonSecurityTokenServiceClient(immmutableCredentials.AccessKey, GetClearSecretKey(immmutableCredentials.SecureSecretKey), config);
                }
                else
                {
                    stsClient = new AmazonSecurityTokenServiceClient(immmutableCredentials.AccessKey, immmutableCredentials.ClearSecretKey, config);
                }
                return stsClient;
            }
        }