# `Password`

A password as a person types it (NIST SP 800-63B): 8 to 256 characters, none a control character. Taken from an `Input`, hashed with `crypto.hash_password` and checked with `crypto.verify_password`; a secret value, never sent, logged, stored or shown.

[Security](types.md#security); not ordered; since Jadpo 0.1.0.

## Make one

It comes from outside your code, a secret value that never appears in it.

`text.parse(raw, as: Password)` reads one from its text; text that isn't one at all fails `malformed`, such as `Tr0ub4d`, `"tab\there!"` or `"two\nlines"`.

## Text, JSON and storage

`text.parse` reads one from its text, as it is typed. Nothing writes it: `text.from` and `text.format` don't take it, JSON writes it as `"<redacted Password>"`, and it is never stored.

## Shown to people

`text.format` doesn't take it: a `Password` is never shown.

## Operations

- `crypto.hash_password(password: Password) -> PasswordHash`: The password's Argon2id hash at the release's parameters (19 MiB, 2 passes, 1 lane), as a PHC string, with a fresh random salt.
- `crypto.verify_password(password: Password, hash: PasswordHash) -> PasswordCheck`: `correct`, `wrong`, or `correct_outdated` when the hash was made with older parameters and a fresh one should be stored; compared in constant time.

Like every standard type, it also has the contract's own operations: `text.parse`, `json.read`, `json.write` and `==`. It isn't ordered, so `<` and sorting don't take it. [Every standard type meets one contract](../topics/every-standard-type-meets-one-contract.md) says how they work.