utput );
	}
endif;

/**
 * Internal compat function to mimic hash_hmac().
 *
 * @ignore
 * @since 3.2.0
 *
 * @param string $algo       Hash algorithm. Accepts 'md5' or 'sha1'.
 * @param string $data       Data to be hashed.
 * @param string $key        Secret key to use for generating the hash.
 * @param bool   $raw_output Optional. Whether to output raw binary data (true),
 *                           or lowercase hexits (false). Default false.
 * @return string|false The hash in output determined by `$raw_output`. False if `$algo`
 *                      is unknown or invalid.
 */
function _hash_hmac( $algo, $data, $key, $raw_output = false ) {
	$packs = array(
		'md5'  => 'H32',
		'sha1' => 'H40',
	);

	if ( ! isset( $packs[ $algo ] ) ) {
		return false;
	}

	$pack = $packs[ $algo ];

	if ( strlen( $key ) > 64 ) {
		$key = pack( $pack, $algo( $key ) );
	}

	$key = str_pad( $key, 64, chr( 0 ) );

	$ipad = ( substr( $key, 0, 64 ) ^ str_repeat( chr( 0x36 ), 64 ) );
	$opad = ( substr( $key, 0, 64 ) ^ str_repeat( chr( 0x5C ), 64 ) );

	$hmac = $algo( $opad . pack( $pack, $algo( $ipad . $data ) ) );

	if ( $raw_output ) {
		return pack( $pack, $hmac );
	}
	return $hmac;
}

if ( ! function_exists( 'hash_equals' ) ) :
	/**
	 * Timing attack safe string comparison
	 *
	 * Compares two strings using the same time whether they're equal or not.
	 *
	 * Note: It can leak the length of a string when arguments of differing length are supplied.
	 *
	 * This function was added in PHP 5.6.
	 * However, the Hash extension may be explicitly disabled on select servers.
	 * As of PHP 7.4.0, the Hash extension is a core PHP extension and can no
	 * longer be disabled.
	 * I.e. when PHP 7.4.0 becomes the minimum requirement, this polyfill
	 * can be safely removed.
	 *
	 * @since 3.9.2
	 *
	 * @param string $a Expected string.
	 * @param string $b Actual, user supplied, string.
	 * @return bool Whether strings are equal.
	 */
	function hash_equals( $a, $b ) {
		$a_length = strlen( $a );
		if ( strlen( $b ) !== $a_length ) {
			return false;
		}
		$result = 0;

		// Do not attempt to "optimize" this.
		for ( $i = 0; $i < $a_length; $i++ ) {
			$result |= ord( $a[ $i ] ) ^ ord( $b[ $i ] );
		}

		return 0 === $result;
	}
endif;

// random_int() was introduced in PHP 7.0.
if ( ! function_exists( 'random_int' ) ) {
	require ABSPATH . WPINC . '/random_compat/random.php';
}
// sodium_crypto_box() was introduced in PHP 7.2.
if ( ! function_exists( 'sodium_crypto_box' ) ) {
	require ABSPATH . WPINC . '/sodium_compat/autoload.php';
}

if ( ! function_exists( 'is_countable' ) ) {
	/**
	 * Polyfill for is_countable() function added in PHP 7.3.
	 *
	 * Verify that the content of a variable is an array or an object
	 * implementing the Countable interface.
	 *
	 * @since 4.9.6
	 *
	 * @param mixed $var The value to check.
	 * @return bool True if `$var` is countable, false otherwise.
	 */
	function is_countable( $var ) {
		return ( is_array( $var )
			|| $var instanceof Countable
			|| $var instanceof SimpleXMLElement
			|| $var instanceof ResourceBundle
		);
	}
}

if ( ! function_exists( 'is_iterable' ) ) {
	/**
	 * Polyfill for is_iterable() function added in PHP 7.1.
	 *
	 * Verify that the content of a variable is an array or an object
	 * implementing the Traversable interface.
	 *
	 * @since 4.9.6
	 *
	 * @param mixed $var The value to check.
	 * @return bool True if `$var` is iterable, false otherwise.
	 */
	function is_iterable( $var ) {
		return ( is_array( $var ) || $var instanceof Traversable );
	}
}

if ( ! function_exists( 'str_starts_with' ) ) {
	/**
	 * Polyfill for `str_starts_with()` function added in PHP 8.0.
	 *
	 * Performs a case-sensitive check indicating if
	 * the haystack begins with needle.
	 *
	 * @since 5.9.0
	 *
	 * @param string $haystack The string to search in.
	 * @param string $needle   The substring to search for in the `$haystack`.
	 * @return bool True if `$haystack` starts with `$needle`, otherwise false.
	 */
	function str_starts_with( $haystack, $needle ) {
		if ( '' === $needle ) {
			return true;
		}

		return 0 === strpos( $haystack, $needle );
	}
}

if ( ! function_exists( 'str_ends_with' ) ) {
	/**
	 * Polyfill for `str_ends_with()` function added in PHP 8.0.
	 *
	 * Performs a case-sensitive check indicating if
	 * the haystack ends with needle.
	 *
	 * @since 5.9.0
	 *
	 * @param string $haystack The string to search in.
	 * @param string $needle   The substring to search for in the `$haystack`.
	 * @return bool True if `$haystack` ends with `$needle`, otherwise false.
	 */
	function str_ends_with( $haystack, $needle ) {
		if ( '' === $haystack ) {
			return '' === $needle;
		}

		$len = strlen( $needle );

		return substr( $haystack, -$len, $len ) === $needle;
	}
}

// IMAGETYPE_WEBP constant is only defined in PHP 7.1 or later.
if ( ! defined( 'IMAGETYPE_WEBP' ) ) {
	define( 'IMAGETYPE_WEBP', 18 );
}

// IMG_WEBP constant is only defined in PHP 7.0.10 or later.
if ( ! defined( 'IMG_WEBP' ) ) {
	define( 'IMG_WEBP', IMAGETYPE_WEBP ); // phpcs:ignore PHPCompatibility.Constants.NewConstants.imagetype_webpFound
}