Windows Authentication in sharepoint 2013

Question

Hi,
I am trying to connect to a sharepoint site list and doing some operations on list Items. I did it successfully using the following code snippet. but by hard coding my userId and Password. Is there any way to achieve the same thing with out hard coding ?
I mean getting my windows credentials and pass them to sharepoint. 
               string url = "https://siteurl";
                using (ClientContext clientContext = new ClientContext(url))
                    SecureString passWord = new SecureString();
                    string userName = "[email protected]";
                    string passWord2 = "xxxxxxxx";
                    foreach (char c in passWord2.ToCharArray()) passWord.AppendChar(c);
                   clientContext.Credentials = new SharePointOnlineCredentials(userName, passWord);
                    CredentialCache obj = new CredentialCache();
                    var ob=obj.GetCredential(new Uri(url), "User");
                    Web web = clientContext.Web;
                    Microsoft.SharePoint.Client.List list = clientContext.Web.Lists.GetByTitle("List");
                    clientContext.Load(list.Fields);
                    clientContext.ExecuteQuery();
                    foreach (Microsoft.SharePoint.Client.Field field in list.Fields)
                        Console.WriteLine(field.InternalName);
            catch (Exception e)
                Console.WriteLine("Caught Exception....");
for the above code its working fine.  Looking for another which uses my windows credential for updating/deleting the list.
I tried using System.Net.CredentialCache.DefaultNetworkCredentials.
But It returning a null object.
Any help would be a great help. 
MANIKANTA

Answer 1

http://www.mavention.com/blog/inconvenient-excel-rest-services-anonymous-users
singSystem;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Runtime.InteropServices;
using System.Security;
using System.Web;
using Microsoft.BusinessData.Infrastructure.SecureStore;
using Microsoft.Office.SecureStoreService.Server;
using Microsoft.SharePoint;
namespace Mavention.AnonymousExcelRestServices {
    [Guid("51dfb6a4-1460-4641-9727-fc1ce0e7c742")]
    public class
Chart : IHttpHandler {
        string
worksheet;
        string
chart;
        string
multiplyBy;
        CookieContainer cookies;
        CredentialCache credentialCache;
        #region IHttpHandler Members
        public
bool IsReusable {
            get
{ return false; }
        public
void ProcessRequest(HttpContext context) {
            Authenticate(context);
        #endregion
        private
void Authenticate(HttpContext context) {
            cookies =
new CookieContainer();
            string
url = String.Format("{0}/_layouts/viewlsts.aspx",
                SPContext.Current.Site.Url.TrimEnd('/'));
            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
            request.Method =
"GET";
            request.Accept =
            request.CookieContainer = cookies;
            string
username = null;
            string
domain = null;
            string
password = null;
            GetCredentials(out
username, out domain, out
password);
            credentialCache =
new CredentialCache();
            credentialCache.Add(new
Uri(SPContext.Current.Site.Url), "NTLM", new
NetworkCredential(username, password, domain));
            request.Credentials = credentialCache;
            request.GetResponse();
            LoadChartImage();
        private
void LoadChartImage() {
            InitiateVariables(HttpContext.Current);
            string
url = String.Format("{0}/_vti_bin/ExcelRest.aspx/{1}/Model/Charts('{2}'){3}",
                SPContext.Current.Site.Url.TrimEnd('/'),
                worksheet,
                chart,
                !String.IsNullOrEmpty(multiplyBy) ? String.Format("?Ranges('MultiplyBy')={0}", multiplyBy) : String.Empty);
            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
            request.Method =
"GET";
            request.CookieContainer = cookies;
            request.Credentials = credentialCache;
            byte[] buffer =
null;
            byte[] file =
null;
            using
(HttpWebResponse chartResponse = (HttpWebResponse)request.GetResponse()) {
                using
(BinaryReader br = new BinaryReader(chartResponse.GetResponseStream())) {
                    using
(MemoryStream ms = new MemoryStream()) {
                        buffer = br.ReadBytes(1024);
                        while
(buffer.Length > 0) {
                            ms.Write(buffer, 0, buffer.Length);
                            buffer = br.ReadBytes(1024);
                        file =
new byte[(int)ms.Length];
                        ms.Position = 0;
                        ms.Read(file, 0, file.Length);
                        ms.Close();
                        br.Close();
                chartResponse.Close();
            HttpContext.Current.Response.ContentType =
"image/png";
            HttpContext.Current.Response.BinaryWrite(file);
        private
void InitiateVariables(HttpContext context) {
            worksheet = context.Request.QueryString["w"];
            chart = context.Request.QueryString["c"];
            multiplyBy = context.Request.QueryString["m"];
        private
static void GetCredentials(out
string username, out string
domain, out string password) {
            username =
"waldek";
            domain =
"win2008";
            password =
"pass@word1";
Or
http://sharepoint.stackexchange.com/questions/21947/how-to-fix-credential-issue
If you're going to specify the password, I believe it has to be a secure string:
$WS.Credentials = [System.Net.NetworkCredential]::("USERNAME", (ConvertTo-SecureString "PASSWORD" -AsPlainText -force))
If you're specifying a domain, I believe it needs to be as a parameter, not as a fully qualified username:
$WS.Credentials = [System.Net.NetworkCredential]::("USERNAME", (ConvertTo-SecureString "PASSWORD" -AsPlainText -force), "DOMAIN")
See MSDN:
http://msdn.microsoft.com/en-us/library/system.net.networkcredential.aspx
If this helped you resolve your issue, please mark it Answered