IntSecurity.cs

using System.IO;
using System.Security;
using System.Security.Permissions;

namespace System.ComponentModel
{
    [HostProtection(SecurityAction.LinkDemand, SharedState = true)]
    internal static class IntSecurity
    {
        public static readonly CodeAccessPermission UnmanagedCode = new SecurityPermission(SecurityPermissionFlag.UnmanagedCode);

        public static readonly CodeAccessPermission FullReflection = new ReflectionPermission(PermissionState.Unrestricted);

        public static string UnsafeGetFullPath(string fileName)
        {
            FileIOPermission fileIOPermission = new FileIOPermission(PermissionState.None);
            fileIOPermission.AllFiles = FileIOPermissionAccess.PathDiscovery;
            fileIOPermission.Assert();
            try
            {
                return Path.GetFullPath(fileName);
            }
            finally
            {
                CodeAccessPermission.RevertAssert();
            }
        }
    }
}