原型

hash_hmac( $algo,  $data,  $key,  $raw_output = false )

源文件

路径:wp-includes/compat.php

<?php
...
 * For $encoding === UTF-8, the `$str` input is expected to be a valid UTF-8 byte
 * sequence. The behavior of this function for invalid inputs is undefined.
 *
...
?>

其他

英文文档:https://developer.wordpress.org/reference/functions/hash_hmac/