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Diffstat (limited to 'wp-includes/class-wp-http-encoding.php')
| -rw-r--r-- | wp-includes/class-wp-http-encoding.php | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/wp-includes/class-wp-http-encoding.php b/wp-includes/class-wp-http-encoding.php new file mode 100644 index 0000000..f2f82e3 --- /dev/null +++ b/wp-includes/class-wp-http-encoding.php @@ -0,0 +1,234 @@ +<?php +/** + * HTTP API: WP_Http_Encoding class + * + * @package WordPress + * @subpackage HTTP + * @since 4.4.0 + */ + +/** + * Core class used to implement deflate and gzip transfer encoding support for HTTP requests. + * + * Includes RFC 1950, RFC 1951, and RFC 1952. + * + * @since 2.8.0 + */ +#[AllowDynamicProperties] +class WP_Http_Encoding { + + /** + * Compress raw string using the deflate format. + * + * Supports the RFC 1951 standard. + * + * @since 2.8.0 + * + * @param string $raw String to compress. + * @param int $level Optional. Compression level, 9 is highest. Default 9. + * @param string $supports Optional, not used. When implemented it will choose + * the right compression based on what the server supports. + * @return string|false Compressed string on success, false on failure. + */ + public static function compress( $raw, $level = 9, $supports = null ) { + return gzdeflate( $raw, $level ); + } + + /** + * Decompression of deflated string. + * + * Will attempt to decompress using the RFC 1950 standard, and if that fails + * then the RFC 1951 standard deflate will be attempted. Finally, the RFC + * 1952 standard gzip decode will be attempted. If all fail, then the + * original compressed string will be returned. + * + * @since 2.8.0 + * + * @param string $compressed String to decompress. + * @param int $length The optional length of the compressed data. + * @return string|false Decompressed string on success, false on failure. + */ + public static function decompress( $compressed, $length = null ) { + + if ( empty( $compressed ) ) { + return $compressed; + } + + $decompressed = @gzinflate( $compressed ); + if ( false !== $decompressed ) { + return $decompressed; + } + + $decompressed = self::compatible_gzinflate( $compressed ); + if ( false !== $decompressed ) { + return $decompressed; + } + + $decompressed = @gzuncompress( $compressed ); + if ( false !== $decompressed ) { + return $decompressed; + } + + if ( function_exists( 'gzdecode' ) ) { + $decompressed = @gzdecode( $compressed ); + + if ( false !== $decompressed ) { + return $decompressed; + } + } + + return $compressed; + } + + /** + * Decompression of deflated string while staying compatible with the majority of servers. + * + * Certain Servers will return deflated data with headers which PHP's gzinflate() + * function cannot handle out of the box. The following function has been created from + * various snippets on the gzinflate() PHP documentation. + * + * Warning: Magic numbers within. Due to the potential different formats that the compressed + * data may be returned in, some "magic offsets" are needed to ensure proper decompression + * takes place. For a simple pragmatic way to determine the magic offset in use, see: + * https://core.trac.wordpress.org/ticket/18273 + * + * @since 2.8.1 + * + * @link https://core.trac.wordpress.org/ticket/18273 + * @link https://www.php.net/manual/en/function.gzinflate.php#70875 + * @link https://www.php.net/manual/en/function.gzinflate.php#77336 + * + * @param string $gz_data String to decompress. + * @return string|false Decompressed string on success, false on failure. + */ + public static function compatible_gzinflate( $gz_data ) { + + // Compressed data might contain a full header, if so strip it for gzinflate(). + if ( str_starts_with( $gz_data, "\x1f\x8b\x08" ) ) { + $i = 10; + $flg = ord( substr( $gz_data, 3, 1 ) ); + if ( $flg > 0 ) { + if ( $flg & 4 ) { + list($xlen) = unpack( 'v', substr( $gz_data, $i, 2 ) ); + $i = $i + 2 + $xlen; + } + if ( $flg & 8 ) { + $i = strpos( $gz_data, "\0", $i ) + 1; + } + if ( $flg & 16 ) { + $i = strpos( $gz_data, "\0", $i ) + 1; + } + if ( $flg & 2 ) { + $i = $i + 2; + } + } + $decompressed = @gzinflate( substr( $gz_data, $i, -8 ) ); + if ( false !== $decompressed ) { + return $decompressed; + } + } + + // Compressed data from java.util.zip.Deflater amongst others. + $decompressed = @gzinflate( substr( $gz_data, 2 ) ); + if ( false !== $decompressed ) { + return $decompressed; + } + + return false; + } + + /** + * What encoding types to accept and their priority values. + * + * @since 2.8.0 + * + * @param string $url + * @param array $args + * @return string Types of encoding to accept. + */ + public static function accept_encoding( $url, $args ) { + $type = array(); + $compression_enabled = self::is_available(); + + if ( ! $args['decompress'] ) { // Decompression specifically disabled. + $compression_enabled = false; + } elseif ( $args['stream'] ) { // Disable when streaming to file. + $compression_enabled = false; + } elseif ( isset( $args['limit_response_size'] ) ) { // If only partial content is being requested, we won't be able to decompress it. + $compression_enabled = false; + } + + if ( $compression_enabled ) { + if ( function_exists( 'gzinflate' ) ) { + $type[] = 'deflate;q=1.0'; + } + + if ( function_exists( 'gzuncompress' ) ) { + $type[] = 'compress;q=0.5'; + } + + if ( function_exists( 'gzdecode' ) ) { + $type[] = 'gzip;q=0.5'; + } + } + + /** + * Filters the allowed encoding types. + * + * @since 3.6.0 + * + * @param string[] $type Array of what encoding types to accept and their priority values. + * @param string $url URL of the HTTP request. + * @param array $args HTTP request arguments. + */ + $type = apply_filters( 'wp_http_accept_encoding', $type, $url, $args ); + + return implode( ', ', $type ); + } + + /** + * What encoding the content used when it was compressed to send in the headers. + * + * @since 2.8.0 + * + * @return string Content-Encoding string to send in the header. + */ + public static function content_encoding() { + return 'deflate'; + } + + /** + * Whether the content be decoded based on the headers. + * + * @since 2.8.0 + * + * @param array|string $headers All of the available headers. + * @return bool + */ + public static function should_decode( $headers ) { + if ( is_array( $headers ) ) { + if ( array_key_exists( 'content-encoding', $headers ) && ! empty( $headers['content-encoding'] ) ) { + return true; + } + } elseif ( is_string( $headers ) ) { + return ( stripos( $headers, 'content-encoding:' ) !== false ); + } + + return false; + } + + /** + * Whether decompression and compression are supported by the PHP version. + * + * Each function is tested instead of checking for the zlib extension, to + * ensure that the functions all exist in the PHP version and aren't + * disabled. + * + * @since 2.8.0 + * + * @return bool + */ + public static function is_available() { + return ( function_exists( 'gzuncompress' ) || function_exists( 'gzdeflate' ) || function_exists( 'gzinflate' ) ); + } +} |