Module password 

Excel-compatible password hashes for protection (ECMA-376 Part 1 §18.2.29 and §18.3.1.66 attribute sets): the legacy 16-bit hash (password="CC1A") and the iterated, salted hash (algorithmName, hashValue, saltValue, spinCount). Protection is a convenience, not security, but verification really checks the password: an unsupported variant is refused, never accepted.

Enums

PasswordHash

Constants

DEFAULT_SPIN_COUNT

Excel’s default spin count for new passwords.

MAX_SPIN_COUNT

Largest spin count accepted when verifying (the documented maximum); a file asking for more would only make verification hang.

Functions

legacy_hash

The legacy 16-bit password hash: each UTF-16 unit contributes its low byte (its high byte when the low one is zero), folded in from the last character with a 15-bit rotation, then the length and the constant 0xCE4B.

salt_from

A 16-byte salt derived from seed (callers mix in what varies: names, a counter, the clock).