The only real answer here is talk to an actual lawyer rather than a bunch of Joe Blows on the internet. Case in point: Laws will vary depending on country and you haven’t specified what country you’re in. The set of laws you’re subject to are possibly entirely different than the set of laws each commenter here is familiar with. Never take legal advice from the internet.
But if you’re only looking to publish the source code as a resume item, it’s not worth the legal exposure or time/money to talk to a lawyer. Find something else to write and put on your resume.
I suppose you could argue an “illegal number” is: https://en.wikipedia.org/wiki/Illegal_number.
For example, the HD DVD encryption key saga was originally fought via DMCA notices to Digg: https://en.wikipedia.org/wiki/AACS_encryption_key_controversy