Looking for Reverse Engineering Challenges

[NULLj0k3]

Some years ago (1-3) I got my hands on some reverse engineering challenges. 
They started simple, like "add a save option" on a text editor. 
I do not remember much about them, but I am trying to find them again. 
If anyone has any good reverse engineering "challenges" that are not entirelly "crack" based, and are focused more on the understanding of a programs flow, it would be a big help to me.
Not sure if this is the right section though.
Thank you in advance guys.

[rashash]

maybe u found ur challenge here

[Dreamer]

try this

http://flare-on.com/

[bolzano_1989]

Several reverse engineering challenges for you:

• http://www.reteam.org/challenges.html
  
• http://old.honeynet.org/reverse/
  
• https://www.honeynet.org/node/668
  
• https://ches15challenge.com/