Getting the redbrown calf or any other calf you want

Our research on Farmville is still going on. Today we are going to tell you something about the lonely animals links and how you can change them to get another rewards.

The links in Facebook have this format:

http://apps.facebook.com/onthefarm/track.php?creative&cat=lonely_cow&subcat=pink&key=&next=lonelycow.php%3Fowner_id%3D%26lonely_cow_id%3D%26animalType%3Dcow_pink%26lonely_cow_sig%3D&ref=nf

Interesting is, that the key is not needed and if you use farmville.com to play you will get another links like:

http://www.farmville.com/lonelycow.php?owner_id=1234&animalType=cow_pink&lonely_cow_id=123456456345&lonely_cow_sig=234523452345

Since the farmville.com URL is simpler, we concentrate on this.

Lets have a look at the variables.

owner_id = this is the facebook id of the user, who found the animal
animalType = this is the animal type like cow_pinkm calf_pink , ...
lonely_cow_id = this id is unique for every lost animal
lonely_cow_sig = this is a signature of the string

Zynga is using this signature to protect user changes in the url like changing the animalType to calf_redbrown.

Interesting is, that Zynga is only saving the cow_id on the serverside. The signature is calculated by the client.
What does this mean for us? We can generate our own links, just by using the cow_id.

Back to redbrown calf, this calf cannot be born, because the redbrown cow cannot be stored in the dairybarn. But it is a valid object in the gamedata and we can now convert every lonely cow link to a redbrown calf link.

As proof of concept we implemented this and testet it with some calfs, seems like you can generate every calf from any lonely cow link, even from deer bucks or horses.

Visit http://fvinternals.funpic.de/convert.php and test it with a valid lonely animal link.