please help me！how did I Get the unity shader sources？I will made a shadow for Sprite

Unity Engine
1

I read this（http://forum.unity3d.com/threads/why-cant-sprites-gameobjects-cast-shadows.215461/），But，I can’t find Sprite-diffuse.shader，What should I do？

2

Check the unity archive site.

3

I don’t understand，I only see some unity XX in “https://unity3d.com/get-unity/download/archive”

4

Actually try clicking the downloads button. Notice the arrow on it?

5

OH yeah ，THX ，：）