I emailed Andres, the author, and he said "the code didn't have a license because I meant to put no restrictions on it...  The MIT license is fine with me.  In fact, I released the Hash Analysis Tool and Assessments under the MIT license already."

Then he asked a great question: "Let me know what you need and I'll put it in.  Or do you need that the book explicitly states the code mentioned therein is MIT?"

I've been contacting many people to declare code as MIT.  What "proof" is considered acceptable?  I've been announcing it on the mailing list, so anyone could search back, contact me, and I could send them the email I received from the author, but that requires remembering the post, finding it, etc.  What's the best way to go about this?  License gurus?

Sean