Subresource Integrity

// 1. Hook เพื่อแทรก SRI ให้ Script และ Style
add_filter( 'script_loader_tag', 'auto_add_sri', 10, 2 );
add_filter( 'style_loader_tag', 'auto_add_sri', 10, 2 );

function auto_add_sri( $tag, $handle ) {
    if ( ! preg_match( '/\s(src|href)=[\x27\x22]([^\x27\x22]+)[\x27\x22]/i', $tag, $matches ) ) {
        return $tag;
    }
    
    $attr = $matches[1]; 
    $url  = $matches[2];

    $site_url = site_url();
    if ( strpos( $url, 'http' ) !== 0 || strpos( $url, $site_url ) === 0 ) {
        return $tag;
    }

    $hash_key = 'sri_hash_' . md5( $url );
    $hash = get_transient( $hash_key );

    if ( false === $hash ) {
        $response = wp_remote_get( $url, array( 'timeout' => 5 ) ); 
        
        if ( is_wp_error( $response ) || wp_remote_retrieve_response_code( $response ) != 200 ) {
            set_transient( $hash_key, 'failed', HOUR_IN_SECONDS );
            return $tag;
        }

        $content = wp_remote_retrieve_body( $response );
        $hash = 'sha384-' . base64_encode( hash( 'sha384', $content, true ) );
        
        set_transient( $hash_key, $hash, 12 * HOUR_IN_SECONDS );
    }

    if ( $hash && $hash !== 'failed' ) {
        $replace_target = ' ' . $attr . '=';
        $replace_with = ' integrity="' . $hash . '" crossorigin="anonymous" ' . $attr . '=';
        return str_replace( $replace_target, $replace_with, $tag );
    }

    return $tag;
}

// 1. Hook เพื่อแทรก SRI ให้ Script และ Style
add_filter( 'script_loader_tag', 'auto_add_sri', 10, 2 );
add_filter( 'style_loader_tag', 'auto_add_sri', 10, 2 );

function auto_add_sri( $tag, $handle ) {
    if ( ! preg_match( '/\s(src|href)=[\x27\x22]([^\x27\x22]+)[\x27\x22]/i', $tag, $matches ) ) {
        return $tag;
    }
    
    $attr = $matches[1]; 
    $url  = $matches[2];

    $site_url = site_url();
    if ( strpos( $url, 'http' ) !== 0 || strpos( $url, $site_url ) === 0 ) {
        return $tag;
    }

    $hash_key = 'sri_hash_' . md5( $url );
    $hash = get_transient( $hash_key );

    if ( false === $hash ) {
        $response = wp_remote_get( $url, array( 'timeout' => 5 ) ); 
        
        if ( is_wp_error( $response ) || wp_remote_retrieve_response_code( $response ) != 200 ) {
            set_transient( $hash_key, 'failed', HOUR_IN_SECONDS );
            return $tag;
        }

        $content = wp_remote_retrieve_body( $response );
        $hash = 'sha384-' . base64_encode( hash( 'sha384', $content, true ) );
        
        set_transient( $hash_key, $hash, 12 * HOUR_IN_SECONDS );
    }

    if ( $hash && $hash !== 'failed' ) {
        $replace_target = ' ' . $attr . '=';
        $replace_with = ' integrity="' . $hash . '" crossorigin="anonymous" ' . $attr . '=';
        return str_replace( $replace_target, $replace_with, $tag );
    }

    return $tag;
}