[veqq]

[u/forgot-CLHS](https://www.reddit.com/r/lisp/comments/1ikrz1g/shout_out_to_...) notes that Common Lisp's defact standard cryptography library Ironclad's [implementation](https://github.com/sharplispers/ironclad/blob/master/src/kdf...) avoids such problems!

``` (defmethod derive-key ((kdf bcrypt) passphrase salt iteration-count key-length) (declare (type (simple-array (unsigned-byte 8) (*)) passphrase salt)) (unless (<= (length passphrase) 72) (error 'ironclad-error :format-control "PASSPHRASE must be at most 72 bytes long."))...) ```