Image problem iPad Theme

[Ipheuria]

Can anyone figure out which image files would give me this image. On the lock screen when you enter a passcode the area the entries go into. I need to customize the theme on my iPad which has three boxes which don't fit the entries properly. I need to make it one solid box like in the example image.

 

[Ipheuria]

I found it they are:

UIPasscodeFieldBackground@2x.png
UIPasscodeFieldBackground_Opaque@2x.png

Now that I know I can do something custom but here is what I was trying to achieve.



If you look behind the paper like area you can see the edges of the three boxes.