How to custom CALayer using subclassing

Question

On UIView there are number of CALayers. Each CALayer consists of CAShapeLayers. CAShapeLayers' path property consists of UIBezierPath.

My objective is when i tap on CALayer i want to get points which i used in the drawing of UIBezierPath. For that i thought of subclassing CALayer which has NSMutableArray to store points. I will be saving points when i am drawing in particular CALayer. So whenever i tap on particular CALayer i will get points associated to that. Also i want to give tag to each CALayer. I do not know how to do this.

The second way is to use CALayer's inbuilt property which will give me points captured in CALayer. But i am not aware of this kind of property.

Please share your ideas how to accomplish this task?