.. index:: single: hmac_protocol
.. _hmac_protocol/0:

.. rst-class:: right

**protocol**

``hmac_protocol``
=================

Protocol for one-shot HMAC digest computation using hash objects implementing ``hash_digest_protocol``.

| **Availability:** 
|    ``logtalk_load(hmac(loader))``

| **Author:** Paulo Moura
| **Version:** 1:0:0
| **Date:** 2026-04-16

| **Compilation flags:**
|    ``static``


| **Dependencies:**
|   (none)


| **Remarks:**
|    (none)

| **Inherited public predicates:**
|    (none)

.. contents::
   :local:
   :backlinks: top

Public predicates
-----------------

.. index:: digest/4
.. _hmac_protocol/0::digest/4:

``digest/4``
^^^^^^^^^^^^

Computes the full HMAC digest for a hash object, key bytes, and message bytes.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``digest(Hash,KeyBytes,MessageBytes,DigestBytes)``
| **Mode and number of proofs:**
|    ``digest(+object_identifier,+list(byte),+list(byte),--list(byte))`` - ``one``


------------

.. index:: hex_digest/4
.. _hmac_protocol/0::hex_digest/4:

``hex_digest/4``
^^^^^^^^^^^^^^^^

Computes the full HMAC digest for a hash object, key bytes, and message bytes, returning a lowercase hexadecimal atom.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``hex_digest(Hash,KeyBytes,MessageBytes,HexDigest)``
| **Mode and number of proofs:**
|    ``hex_digest(+object_identifier,+list(byte),+list(byte),--atom)`` - ``one``


------------

.. index:: digest/5
.. _hmac_protocol/0::digest/5:

``digest/5``
^^^^^^^^^^^^

Computes a truncated HMAC digest containing the requested number of leftmost bytes.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``digest(Hash,KeyBytes,MessageBytes,Length,DigestBytes)``
| **Mode and number of proofs:**
|    ``digest(+object_identifier,+list(byte),+list(byte),+integer,--list(byte))`` - ``one``


------------

.. index:: hex_digest/5
.. _hmac_protocol/0::hex_digest/5:

``hex_digest/5``
^^^^^^^^^^^^^^^^

Computes a truncated HMAC digest containing the requested number of leftmost bytes and returns it as a lowercase hexadecimal atom.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``hex_digest(Hash,KeyBytes,MessageBytes,Length,HexDigest)``
| **Mode and number of proofs:**
|    ``hex_digest(+object_identifier,+list(byte),+list(byte),+integer,--atom)`` - ``one``


------------

Protected predicates
--------------------

(none)

Private predicates
------------------

(none)

Operators
---------

(none)

.. seealso::

   :ref:`hash_digest_protocol <hash_digest_protocol/0>`