Global Impersonation in SharePoint 2010

Question

I have a SharePoint site with anonymous access allowed.

I have a feature, that needs to access Shared Documents (both read and write) and hence when accessed it asks for login.

I want to implement global impersonation in a way that all users are auto-loggedin with a per-defined (preferably via Global.asax) account when they access the site so that they can perform what ever they want without having to login.

I don't care about the security issues as this is a test site I just want to make the user experience as simple as possible.

Once solution I already know is to share username and password on main page and let users use that to login. But I don't want users to perform an extra login step.

Urgent help is really appreciated.

Answer 1

please follow my explanation on this link:

SharePoint -access to path is denied

you dont need to change much and will grant the annoymous user access to any list/library without the need to login ;)

taken from the link above:

/// <summary>
/// get the system token from the list of users to elevate spsite
/// </summary>
/// <param name="spSite"></param>
/// <returns></returns>
protected static SPUserToken GetSystemToken(SPSite spSite) 
{     
    SPUserToken res = null;     
    bool oldCatchAccessDeniedException = spSite.CatchAccessDeniedException;
    try
    {
        spSite.CatchAccessDeniedException = false;
        res = spSite.SystemAccount.UserToken;
    }
    catch (UnauthorizedAccessException)
    {
        SPSecurity.RunWithElevatedPrivileges(delegate()
        {
            using (SPSite elevatedSPSite = new SPSite(spSite.ID))
                res = elevatedSPSite.SystemAccount.UserToken;
            // (***)         
        });
    }
    finally    
    {         
        spSite.CatchAccessDeniedException = oldCatchAccessDeniedException;     
    }     
    return res; 
}

to use that function:

        SPUserToken sysToken = null;
        using (SPSite spSite = new SPSite(SPContext.Current.Site.ID))
        {
            //get the system token from the method GetSystemToken and passing the spSite that you want to run under
            sysToken = GetSystemToken(spSite);

            using (SPSite impersonatedSite = new SPSite(siteUrl, sysToken))
            {
                //we are impersonating the [@"SHAREPOINT\SYSTEM"] account
                using (SPWeb web = impersonatedSite.OpenWeb())
                {
                     //do your code here as the impersonated account like updating a list
                }
            }
        }

for detailed explanation please refer to the link!