using System;

using System.Xml;

public class Program

{

    public static void Main()

    {

        var doc = new XmlDocument();

        doc.LoadXml(YourXml);

        XmlNode extendedProtectionPolicy = doc.DocumentElement.SelectSingleNode("//binding[@name='TransportWithHeaderClientAuth']/security/transport[@clientCredentialType='Windows']/extendedProtectionPolicy");

        Console.WriteLine(extendedProtectionPolicy.Attributes["policyEnforcement"].Value);

    }

    private static string YourXml = @"<bindings>

    <wsHttpBinding>

        <binding name=""TransportWithHeaderClientAuth"">

            <security mode=""Transport"">

                <transport clientCredentialType=""Windows"">

                    <extendedProtectionPolicy policyEnforcement=""Always"" />

                </transport>

                <message clientCredentialType=""None"" establishSecurityContext=""false"" negotiateServiceCredential=""false"" />

            </security>

        </binding>

​

        <binding name=""TransportWithMessageClientAuthUserName"">

            <security mode=""TransportWithMessageCredential"">

                <transport clientCredentialType=""None""/>

                <message clientCredentialType=""UserName"" establishSecurityContext=""false"" negotiateServiceCredential=""false"" />

            </security>

        </binding>

​

        <binding name=""TransportWithCertificateClientAuth"">

            <security mode=""Transport"">

                <transport clientCredentialType=""Certificate""/>

                <message clientCredentialType=""None"" establishSecurityContext=""false"" negotiateServiceCredential=""false"" />

            </security>

        </binding>

    </wsHttpBinding>

</bindings>";

}

​

​