How does one access a Security field programmatically?

Question

Back in Sitecore 5 there used to be a class, Sitecore.SecurityModel.SecurityField. Seems like this class was removed in later versions.

So, how does one access a Security field on an item now?

Clarification

What I'm looking for is the Field class to use when I'm reading a field of type Security on an item. For example, the Security Preset field on the item, /sitecore/system/Settings/Security/Presets/Require Login.

Answer 1

You can use item.Security to get an item security field. Return type is ItemSecurity class .

On ItemSecurity class you have few methods :

 public class ItemSecurity
 {
        protected ItemSecurity(Item item);

        public static ItemSecurity FromItem(Item item);
        public virtual bool CanAdmin(Account account);
        public virtual bool CanCreate(Account account);
        public virtual bool CanDelete(Account account);
        public virtual bool CanRead(Account account);
        public virtual bool CanRemoveVersion(Account account);
        public virtual bool CanRename(Account account);
        public virtual bool CanWrite(Account account);
        public virtual AccessRuleCollection GetAccessRules();
        public virtual string GetOwner();
        public virtual void SetAccessRules(AccessRuleCollection accessRules);
}

Answer 2

You should use the raw value of the field and parse it with *AccessRuleCollection

string serializedRules = item["Security Preset"];    
AccessRuleCollection accessRuleCollection = aAccessRuleCollection.FromString(serializedRules);

You can the run through the AccessRules (Sitecore use this in their item:securitypresent command):

foreach (AccessRule current in accessRuleCollection)
{
  accessRules.Helper.RemoveExactMatches(current.Account, current.AccessRight, current.PropagationType, current.PermissionType);
  accessRules.Add(current);
}