Claim Based, Seach and Custom Security Trimmer

Question

I'm facing a problem betweek "claim passage", "token" and Search. Looking online this is a well known bug that everybody solves creating a custom security trimmer...

My solution to the problem works like this:

• Search With Elevated Privileges
• Get the token for the user I want to act like
• Try to access the Url returned from search
• If ok => Return it
• If not ok => not return it

This works correctly but.... Is there any way MORE efficent? If I access to the Item with Elevated Privileges and Check security for the user I pass it is that more efficent?

The way I'm using is like that:

using (SPSite site = new SPSite(ItemURL, token))
            {
                using (SPWeb web = site.OpenWeb())
                {
                    bool security = SPSecurity.CatchAccessDeniedException;

                    SPSecurity.CatchAccessDeniedException = false;

                    try
                    {
                        Match m = Regex.Match(ItemURL, "ID=[0-9]+".ToLower()); //GET ID
                        int listItemID;
                        if (!int.TryParse(Regex.Match(m.Value, "[0-9]+".ToLower()).Value, out listItemID))
                        {
                            throw new Exception("Cannot access to the content: " + ItemURL + " ID: " + m.Value);
                        }
                        SPList list = web.Lists.TryGetList("Contenuti");
                        if (list != null)
                        {
                            SPListItem item = null;
                            try
                            {
                                item = list.Items.GetItemById(listItemID);
                                //OK CODE
                            }
                            catch (Exception exx)
                            {
                                //FAIL CODE
                            }

The other way I see is something like this:

 SPSecurity.RunWithElevatedPrivileges(delegate(){
 using (SPSite site = new SPSite(ItemURL))
            {
                using (SPWeb web = site.OpenWeb())
                {
                    try
                    {
                        Match m = Regex.Match(ItemURL, "ID=[0-9]+".ToLower()); //Prende l'ID
                        int listItemID;
                        if (!int.TryParse(Regex.Match(m.Value, "[0-9]+".ToLower()).Value, out listItemID))
                        {
                            throw new Exception("Cannot access: " + ItemURL + " ID: " + m.Value);
                        }
                        SPList list = web.Lists.TryGetList("Contenuti");
                        if (list != null)
                        {
                            SPListItem item = null;
                            item = list.Items.GetItemById(listItemID);
                            var permission = item.GetUserEffectivePermissions("Username");
                                if (permission >= SPBasePermissions.Open)
                                       //OK CODE
                                else
                                       //FAIL CODE

I think first way is more efficent for the access, but has worst performance caused by exception...

Any suggestion / alternative'?

Thank you!

Answer 1

The extract ID part should be something like:

Match m = Regex.Match(ItemURL, "id=(?<id>\d+)");
int listItemID;
if (!m.Success
 || !int.TryParse(m.Groups["id"].Value, out listItemID)
{
    throw new Exception("Cannot get ID from: " + ItemURL);     
}

The get ListItem part I'd code using list.GetItems with a SPQuery with the query:

<Where>
  <Eq>
    <FieldRef Name='ID'/>",
    <Value Type='Counter'>value from listItemID</Value>
  </Eq>
</Where>