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функция не описана

PasswordHash::gensalt_extended() public WP 1.0

Это метод класса: PasswordHash{}

Хуков нет.

Возвращает

Null. Ничего.

Использование

$PasswordHash = new PasswordHash();
$PasswordHash->gensalt_extended( $input );

Код PasswordHash::gensalt_extended() WP 5.5.1

wp-includes/class-phpass.php
<?php
function gensalt_extended($input)
{
	$count_log2 = min($this->iteration_count_log2 + 8, 24);
	# This should be odd to not reveal weak DES keys, and the
	# maximum valid value is (2**24 - 1) which is odd anyway.
	$count = (1 << $count_log2) - 1;

	$output = '_';
	$output .= $this->itoa64[$count & 0x3f];
	$output .= $this->itoa64[($count >> 6) & 0x3f];
	$output .= $this->itoa64[($count >> 12) & 0x3f];
	$output .= $this->itoa64[($count >> 18) & 0x3f];

	$output .= $this->encode64($input, 3);

	return $output;
}