.. index:: single: http_websocket_handshake
.. _http_websocket_handshake/0:

.. rst-class:: right

**object**

``http_websocket_handshake``
============================

Shared helpers for WebSocket opening-handshake key generation and accept-value computation.

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

| **Author:** Paulo Moura
| **Version:** 1:0:0
| **Date:** 2026-06-11

| **Compilation flags:**
|    ``static, context_switching_calls``


| **Uses:**
|    :ref:`base64 <base64/0>`
|    :ref:`crypto <crypto/0>`
|    :ref:`hash_common_32 <hash_common_32/0>`
|    :ref:`list <list/0>`

| **Remarks:**
|    (none)

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

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

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

.. index:: websocket_opening_key/1
.. _http_websocket_handshake/0::websocket_opening_key/1:

``websocket_opening_key/1``
^^^^^^^^^^^^^^^^^^^^^^^^^^^

Generates a canonical base64-encoded 16-byte WebSocket opening key.

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

| **Template:**
|    ``websocket_opening_key(Key)``
| **Mode and number of proofs:**
|    ``websocket_opening_key(--atom)`` - ``one``


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

.. index:: websocket_accept/2
.. _http_websocket_handshake/0::websocket_accept/2:

``websocket_accept/2``
^^^^^^^^^^^^^^^^^^^^^^

Computes the canonical `Sec-WebSocket-Accept` value for a valid WebSocket opening key.

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

| **Template:**
|    ``websocket_accept(Key,Accept)``
| **Mode and number of proofs:**
|    ``websocket_accept(++term,--atom)`` - ``one_or_error``

| **Exceptions:**
|    ``Key`` is a variable:
|        ``instantiation_error``
|    ``Key`` is not a valid WebSocket opening key value:
|        ``domain_error(http_websocket_key,Key)``


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

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

(no local declarations; see entity ancestors if any)

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

(no local declarations; see entity ancestors if any)

Operators
---------

(none)