5th Underhanded C Contest Now Open

Xcott Craver writes "The next Underhanded C Contest has begun, with a deadline of March 1st. The object of the contest is to write short, readable, clear and innocent C code that somehow commits an evil act. This year's challenge: write a luggage routing program that mysteriously misroutes a customer's bag if a check-in clerk places just the right kind of text in a comment field. The prize is a gift certificate to ThinkGeek.com."

Comments

Re:I'm really impressed

[troll8901]

Here's some points I'd like to highlight, from the 2008 Winners.

• Linus Akesson: The BYTESPERPIXEL macro "gives the false impression that the code intelligently supports higher bit widths" but actually "causes the 8-bit case to leak information into the file" (by exploiting a buffer overflow). ... (thus allowing wiped image data to be reconstructed.)
• Avinash Baliga: The ExpectTrue macro overwrites the image mask (by exploiting a buffer overflow), allowing two bits to survive the wiping, (thus allowing wiped image data to be reconstructed). Furthermore, the evil behavior is concealed in an innocent-looking error checking macro.
• John Meacham: (Winner) The code is "extremely simple, innocent, obvious" ... and devious. "Low-intensity pixels are replaced with a ‘0, and high-intensity pixels replaced with a ‘00 or a ‘000" ... (thus allowing wiped image data to be reconstructed.)

All I can say is, Wow.