CSOM returns 403 Forbidden when checking site collection

Question

I am creating a console application to create Subsite's, lists, list items etc. I have a simple function that checks if a SiteCollection exists and am met with a 403 Forbidden error when calling the ClientContext.ExecuteQuery() function.

Example Code:

using (ClientContext ctx = new ClientContext(url))
{
     Web web = ctx.Web;
     ctx.Load(web);
     ctx.ExecuteQuery(); //403 Error
}

So I read this thread which detailed passing NetworkCredential object to the context. So I changed my code to:

using (ClientContext ctx = new ClientContext(url))
{
     Web web = ctx.Web;
     ctx.Load(web);
     ctx.Credentials = new NetworkCredential("MyUserName", "pass", "domain");
     ctx.ExecuteQuery(); //Still 403's
}

It still 403's and I have gone back to verify the accounts credentials and permissions across the site that I am attempting to access.

Is there an issue with my code or is it something else? Can CSOM go cross server?

UPDATE

The code above works on a server with Active Directory, but not a server utilizing ADFS. ADFS possibly blocking this call?

Answer 1

Just want to add this here. Unfortunately the suggested answers of adding NetworkCredential did not work. I instead switched from using Microsoft.SharePoint.Client dll to the Microsoft.SharePoint library. Everything works now except with the caveat of course that my application now has to be run on a SharePoint server.

Answer 2

Try setting ctx.Credentials before.

Other than that, double check your user/pwd/domain

using (ClientContext ctx = new ClientContext(url))
{
     ctx.Credentials = new NetworkCredential("MyUserName", "pass", "domain");
     Web web = ctx.Web;
     ctx.Load(web);
     ctx.ExecuteQuery(); //Still 403's
}

Answer 3

After struggling with the same issue, I looked at the SharePoint Office PNP core samples, and tried to login using the default browser login, you can try the below sample I got working

string myAdfsSharePoint= "https://abc.myTenant.com/sites/abc";
OfficeDevPnP.Core.AuthenticationManager am = new OfficeDevPnP.Core.AuthenticationManager();
SP.ClientContext ctx = am.GetWebLoginClientContext(myAdfsSharePoint);

Also, make sure to have the default browser signed in, Since I had to prepare an Offline utility for my Client, I was allowed to ! I had to include this DLL from Github OfficeCorePnp Samples