<?php
/**
* Shared image fetcher.
*
* @package LiteSpeed
* @since 7.9.1
*/
namespace LiteSpeed;
defined( 'WPINC' ) || exit();
/**
* Fetch and stage verified image artifacts.
*
* @since 7.9.1
*/
class Img {
/**
* Maximum artifact size in bytes.
*
* @since 7.9.1
*/
const MAX_BYTES = File::REMOTE_MAX_BYTES;
/**
* Fetch failure codes.
*
* @since 7.9.1
*/
const E_NET = File::E_NET;
const E_HTTP = File::E_HTTP;
const E_DATA = File::E_DATA;
const E_FILE = File::E_FILE;
/**
* POSIX `stat()` mode bits: the file-type field and the regular-file value.
*
* @since 7.9.1
*/
const STAT_TYPE_MASK = 0170000;
const STAT_REGULAR = 0100000;
/**
* Normalize a QUIC.cloud artifact URL or origin.
*
* @since 7.9.1
*
* @param mixed $url Artifact URL or origin.
* @param bool $origin_only Whether paths and queries are forbidden.
* @return string|false
*/
public static function normalize_cloud_url( $url, $origin_only = false ) {
if ( ! is_string( $url ) || '' === $url || 2048 < strlen( $url ) || preg_match( '/[\x00-\x20\x7f]/', $url ) ) {
return false;
}
$parts = wp_parse_url( $url );
if (
! is_array( $parts ) || empty( $parts['scheme'] ) || 'https' !== strtolower( $parts['scheme'] ) || empty( $parts['host'] ) ||
isset( $parts['user'] ) || isset( $parts['pass'] ) || isset( $parts['fragment'] ) || ( isset( $parts['port'] ) && 443 !== (int) $parts['port'] ) ||
( $origin_only && ( isset( $parts['query'] ) || ( ! empty( $parts['path'] ) && '/' !== $parts['path'] ) ) )
) {
return false;
}
$host = strtolower( rtrim( $parts['host'], '.' ) );
if ( ! filter_var( $host, FILTER_VALIDATE_DOMAIN, FILTER_FLAG_HOSTNAME ) ) {
return false;
}
$valid_host =
( 11 < strlen( $host ) && '.quic.cloud' === substr( $host, -11 ) ) ||
( 15 < strlen( $host ) && '.quicserver.com' === substr( $host, -15 ) );
if ( ! $valid_host ) {
return false;
}
return $origin_only ? 'https://' . $host : $url;
}
/**
* Normalize a relative path returned by an image service.
*
* @since 7.9.1
*
* @param mixed $path Service-relative path.
* @return string|false
*/
public static function normalize_cloud_path( $path ) {
if ( ! is_string( $path ) || '' === $path || preg_match( '/[\x00-\x20\x7f]/', $path ) ) {
return false;
}
$decoded_path = rawurldecode( $path );
$relative_path = ltrim( $path, '/' );
if (
'' === $relative_path || preg_match( '/[\x00-\x1f\x7f]/', $decoded_path ) || '//' === substr( $decoded_path, 0, 2 ) ||
false !== strpos( $decoded_path, '\\' ) || false !== strpos( $decoded_path, '?' ) || false !== strpos( $decoded_path, '#' ) ||
preg_match( '#^[a-z][a-z0-9+.-]*://#i', $decoded_path ) || preg_match( '#(^|/)\.{1,2}(/|$)#', $decoded_path )
) {
return false;
}
return $relative_path;
}
/**
* Resolve a WordPress image target and bind its closest trusted root.
*
* @since 7.9.1
*
* @param mixed $file Local file path after `litespeed_realpath` filtering.
* @return array|false `[ resolved path, bound root ]`, or false.
*/
public static function local_file( $file ) {
if ( ! is_string( $file ) || '' === $file || false !== strpos( $file, "\0" ) || is_link( $file ) ) {
return false;
}
$file = wp_normalize_path( $file );
if ( ! in_array( strtolower( pathinfo( $file, PATHINFO_EXTENSION ) ), [ 'jpg', 'jpeg', 'png', 'gif' ], true ) ) {
return false;
}
if ( file_exists( $file ) ) {
$file = realpath( $file );
if ( ! $file || ! is_file( $file ) ) {
return false;
}
$file = wp_normalize_path( $file );
$probe = $file;
} else {
$parent = realpath( dirname( $file ) );
if ( ! $parent ) {
return false;
}
$file = trailingslashit( wp_normalize_path( $parent ) ) . basename( $file );
$probe = dirname( $file );
}
$upload_dir = wp_upload_dir();
$roots = ! empty( $upload_dir['basedir'] ) ? [ $upload_dir['basedir'] ] : [];
if ( defined( 'WP_CONTENT_DIR' ) ) {
$roots[] = constant( 'WP_CONTENT_DIR' );
}
$roots[] = ABSPATH;
foreach ( $roots as $root ) {
$bound = File::bind_root( $root );
if ( $bound && File::within( $probe, $bound ) ) {
return [ $file, $bound ];
}
}
return false;
}
/**
* Fetch and stage an image beside its destination.
*
* @param string $url Remote image URL.
* @param string $file Destination path.
* @param string $sum Expected checksum.
* @param string $algo Checksum algorithm.
* @param string $type Image type.
* @param string|array $root Directory the destination must still resolve inside; empty skips the check.
* @return string|\WP_Error Temporary file path or failure.
*/
public static function fetch( $url, $file, $sum, $algo, $type, $root = '' ) {
$tmp = File::download( $url, $file, 60, 0, $root );
if ( is_wp_error( $tmp ) ) {
return $tmp;
}
if ( ! self::_valid( $tmp, $sum, $algo, $type ) ) {
wp_delete_file( $tmp );
return new \WP_Error( self::E_DATA );
}
return $tmp;
}
/**
* Fetch and publish an image.
*
* @param string $url Remote image URL.
* @param string $file Destination path.
* @param string $sum Expected checksum.
* @param string $algo Checksum algorithm.
* @param string $type Image type.
* @param string|array $root Directory the destination must still resolve inside; empty skips the check.
* @param bool $preserve Whether to preserve an original-image backup.
* @return true|\WP_Error True on success, otherwise the failure.
*/
public static function save( $url, $file, $sum, $algo, $type, $root = '', $preserve = false ) {
if ( is_link( $file ) ) {
return new \WP_Error( self::E_FILE );
}
$tmp = self::fetch( $url, $file, $sum, $algo, $type, $root );
if ( is_wp_error( $tmp ) ) {
return $tmp;
}
if ( ! self::publish( $tmp, $file, $root, $preserve ) ) {
return new \WP_Error( self::E_FILE );
}
return true;
}
/**
* Atomically publish an image, preserving the original once when requested.
*
* @since 7.9.1
*
* @param string $staged Staged optimized image.
* @param string $target Destination image.
* @param string|array $root Bound destination root.
* @param bool $preserve Whether to preserve the current original.
* @return bool
*/
public static function publish( $staged, $target, $root = '', $preserve = false ) {
if ( $preserve && file_exists( $target ) ) {
$extension = pathinfo( $target, PATHINFO_EXTENSION );
$backup = $extension ? substr( $target, 0, -strlen( $extension ) ) . 'bk.' . $extension : '';
if ( ! $backup || ( file_exists( $backup ) && ( is_link( $backup ) || ! is_file( $backup ) ) ) ) {
wp_delete_file( $staged );
return false;
}
if ( ! file_exists( $backup ) ) {
$source = self::open_regular( $target, $root );
$stat = $source ? fstat( $source ) : false;
$tmp_backup = $stat ? File::temp_file( dirname( $target ), '.lscwp-bk-', $root ) : false;
$copied = $tmp_backup && self::copy_stream( $source, $tmp_backup, $stat['size'] );
if ( $source ) {
fclose( $source ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose
}
if ( ! $copied || ! File::publish_temp_file( $tmp_backup, $backup, $root ) ) {
if ( $tmp_backup ) {
wp_delete_file( $tmp_backup );
}
wp_delete_file( $staged );
return false;
}
}
}
return File::publish_temp_file( $staged, $target, $root );
}
/**
* Open a regular file and prove the handle is the inode the path named.
*
* Guards a check-then-use gap that spans a network round trip; see `__func.md`.
*
* @since 7.9.1
*
* @param string $file File path.
* @param string|array $root Directory the file must still resolve inside; empty skips the check.
* @return resource|false
*/
public static function open_regular( $file, $root = '' ) {
// phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
$before = @lstat( $file );
if ( ! $before || self::STAT_REGULAR !== ( $before['mode'] & self::STAT_TYPE_MASK ) ) {
return false;
}
// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fopen, WordPress.PHP.NoSilencedErrors.Discouraged
$handle = @fopen( $file, 'rb' );
if ( ! $handle ) {
return false;
}
$after = fstat( $handle );
// Identity alone is not containment: a swapped parent makes lstat and fstat agree on the wrong file.
if ( ! $after || $after['dev'] !== $before['dev'] || $after['ino'] !== $before['ino'] || self::STAT_REGULAR !== ( $after['mode'] & self::STAT_TYPE_MASK ) || ! File::within( $file, $root ) ) {
// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose
fclose( $handle );
return false;
}
return $handle;
}
/**
* Copy an open handle into a path, verifying the byte count.
*
* @since 7.9.1
*
* @param resource $source Open read handle.
* @param string $file Destination path.
* @param int $expected Expected byte count.
* @return bool
*/
public static function copy_stream( $source, $file, $expected ) {
// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fopen, WordPress.PHP.NoSilencedErrors.Discouraged
$dest = @fopen( $file, 'wb' );
if ( ! $dest ) {
return false;
}
$copied = stream_copy_to_stream( $source, $dest );
$ok = false !== $copied && $copied === $expected && fflush( $dest );
// phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose
fclose( $dest );
return $ok;
}
/**
* Validate a downloaded image file.
*
* @param string $file Temporary image file.
* @param string $sum Expected checksum.
* @param string $algo Checksum algorithm.
* @param string $type Image type.
* @return bool
*/
private static function _valid( $file, $sum, $algo, $type ) {
$size = is_string( $file ) && is_file( $file ) ? filesize( $file ) : false;
if ( ! $size || self::MAX_BYTES < $size || ! is_string( $sum ) ) {
return false;
}
if ( 'md5' === $algo ) {
$valid_sum = (bool) preg_match( '/^[a-f0-9]{32}$/iD', $sum );
} elseif ( 'sha256' === $algo ) {
$valid_sum = (bool) preg_match( '/^[a-f0-9]{64}$/iD', $sum );
} else {
return false;
}
$actual = hash_file( $algo, $file );
return $valid_sum && is_string( $actual ) && hash_equals( strtolower( $sum ), $actual ) && self::_is_img( $file, $type );
}
/**
* Validate image magic bytes.
*
* @param string $file Image file.
* @param string $type Image type.
* @return bool
*/
private static function _is_img( $file, $type ) {
// phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents, WordPress.PHP.NoSilencedErrors.Discouraged
$head = @file_get_contents( $file, false, null, 0, 32 );
if ( ! is_string( $head ) ) {
return false;
}
if ( 'webp' === $type ) {
return 12 <= strlen( $head ) && 'RIFF' === substr( $head, 0, 4 ) && 'WEBP' === substr( $head, 8, 4 );
}
if ( 'avif' === $type ) {
$brands = substr( $head, 4, 28 );
return 12 <= strlen( $head ) && 'ftyp' === substr( $head, 4, 4 ) && ( false !== strpos( $brands, 'avif' ) || false !== strpos( $brands, 'avis' ) );
}
return 'ori' === $type && false !== @getimagesize( $file ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
}
}