protocol

# `http_digest_verifier_protocol`

Protocol for HTTP Digest authentication verifiers backed by stored HA1 values.

Availability:
`logtalk_load(http_digest(loader))`
Author: Paulo Moura
Version: 1:0:0
Date: 2026-05-29
Compilation flags:
`static`
Dependencies:
(none)
Remarks:
(none)
Inherited public predicates:
(none)

## Public predicates

### `ha1/4`

Returns the stored lowercase hexadecimal HA1 value for the given normalized digest algorithm family, realm, and username. Fails when the user is unknown for the realm.

Compilation flags:
`static`
Template:
`ha1(Algorithm,Realm,Username,HA1)`
Mode and number of proofs:
`ha1(+atom,++atom,++atom,-atom)` - `zero_or_one`

## Protected predicates

(none)

## Private predicates

(none)

## Operators

(none)