[tptacek]

Same difference. Golang provides cryptographic primitives but few fully-implemented constructions; for instance, if you use Golang's CBC, you have to implement your own padding.

Any Golang program that implements crypto will also need to implement an incomplete and poorly-specified version of NaCl.

(That's true of virtually every other programming language as well.)

[PuerkitoBio]

I agree to some extent, but I wanted to make clear that this book is not about implementing AES or SHA algorithms. It's about using them (the author actually makes that very clear, the algorithms are treated as black boxes).

Yes you can still use them wrong, and you're not much more advanced. But the original comment seemed to suggest it was about implementing the low-level algorithms.