private void CheckAccessControl(AuthorizationRuleCollection authorizationRules, out Boolean canRead, out Boolean canWrite)
{
var rules = authorizationRules
.OfType<FileSystemAccessRule>()
.Where(x => User.IsInRole(x.IdentityReference as SecurityIdentifier) || x.IdentityReference == ((WindowsIdentity)User.Identity).User)
.ToList();
canRead = true;
canWrite = true;
canRead &= rules.Any(x => x.AccessControlType == AccessControlType.Allow &&
x.FileSystemRights.HasFlag(FileSystemRights.Read));
canWrite &= rules.Any(x => x.AccessControlType == AccessControlType.Allow &&
x.FileSystemRights.HasFlag(FileSystemRights.Write));
canRead &= !rules.Any(x => x.AccessControlType == AccessControlType.Deny &&
x.FileSystemRights.HasFlag(FileSystemRights.Read));
canWrite &= !rules.Any(x => x.AccessControlType == AccessControlType.Deny &&
x.FileSystemRights.HasFlag(FileSystemRights.Write));
}