Changing the web.config file programmatically using WebService.ApplyWebConfigModifications() method is giving Error

Question

I have created the FBA site in SharePoint 2010 Farm. The site is allowing both the windows and FBA authentication. I have set the Server administrator (Member of Built in Administrator) as Application pool identity. The same account has sufficient permission in Sql server database for the site.

I have implemented one feature. The feature in turn is modifying the web.Config for the sites in farm. I have placed the code inside the SPSecurity.RunWithElevatedPrivileges block.

public override void FeatureActivated(SPFeatureReceiverProperties properties)
    {
            Guid siteGuid = ((SPWeb)properties.Feature.Parent).Site.ID;

            Guid webGuid = ((SPWeb)properties.Feature.Parent).ID;

            SPSecurity.RunWithElevatedPrivileges(delegate()
            {

                using (SPSite site = new SPSite(siteGuid))
                {
                    using (SPWeb web = site.OpenWeb(webGuid))
                    {
                        SPWebApplication webApp = web.Site.WebApplication;  
                        SPWebConfigModification myModification = new SPWebConfigModification("add[@name=\"assembly\"]", "/configuration/system.web/compilation/assemblies");
                        myModification.Value = "<add assembly=\"MyAssembly, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9e00227b2bfdcg7e\"/>";
                        myModification.Sequence = 0;
                        myModification.Type = SPWebConfigModification.SPWebConfigModificationType.EnsureChildNode;
                        myModification.Owner = typeof(<MyWebpartNameGoesHere>).FullName;
                        webApp.WebConfigModifications.Add(myModification);
                        webApp.WebService.ApplyWebConfigModifications();
                        webApp.Update();

                                                        }
                                               }
                                     });

}

The Code is running perfectly fine for any windows user. But when I enter the site as FBA user and try to activate the feature, I start getting the “Access denied.” error.

Error: System.Security.SecurityException: Access denied. at Microsoft.SharePoint.Administration.SPPersistedObject.BaseUpdate() at Microsoft.SharePoint.Administration.SPWebApplication.ApplyWebConfigModifications() at Microsoft.SharePoint.Administration.SPWebService.ApplyWebConfigModifications()

Can anyone help me to solve this problem?

Answer 1

You seriously have to consider if you want users to activate this code. Making web.config modifications is an administrators thing and not a users' thing.

Please read this: http://www.itidea.nl/index.php/access-denied-when-activating-a-feature/

Regards, Anita