argus-wp-defence/includes/class-argus-quarantine.php

<?php

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class Argus_Quarantine {

	const STATUS_QUARANTINED = 'quarantined';
	const STATUS_RESTORED    = 'restored';
	const STATUS_DELETED     = 'deleted';

	const LOCKDOWN_STATUS_OPTION = 'argus_wpd_quarantine_lockdown_status';
	const HTACCESS_MARKER        = 'ARGUS WordPress Defence -- quarantine store, deny all direct access';

	public static function quarantine_dir() {
		$uploads = wp_get_upload_dir();
		return trailingslashit( $uploads['basedir'] ?? '' ) . 'argus-wpd-data/quarantine';
	}

	public static function ensure_quarantine_lockdown() {
		$dir = self::quarantine_dir();

		if ( ! is_dir( $dir ) && ! wp_mkdir_p( $dir ) ) {
			update_option( self::LOCKDOWN_STATUS_OPTION, 'failed_mkdir', false );
			return false;
		}
		if ( ! is_writable( $dir ) ) { // phpcs:ignore WordPress.WP.AlternativeFunctions
			update_option( self::LOCKDOWN_STATUS_OPTION, 'not_writable', false );
			return false;
		}

		$htaccess = trailingslashit( $dir ) . '.htaccess';
		$rule     = "# " . self::HTACCESS_MARKER . "\nRequire all denied\n";
		$existing = file_exists( $htaccess ) ? file_get_contents( $htaccess ) : false; // phpcs:ignore WordPress.WP.AlternativeFunctions

		if ( false === $existing || false === strpos( $existing, 'Require all denied' ) ) {
			$written = file_put_contents( $htaccess, $rule ); // phpcs:ignore WordPress.WP.AlternativeFunctions
			if ( false === $written ) {
				update_option( self::LOCKDOWN_STATUS_OPTION, 'failed_write', false );
				return false;
			}
		}

		$index = trailingslashit( $dir ) . 'index.php';
		if ( ! file_exists( $index ) ) {
			file_put_contents( $index, "<?php\n// Silence is golden.\n" ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		}

		update_option( self::LOCKDOWN_STATUS_OPTION, 'active', false );
		return true;
	}

	public static function lockdown_status() {
		return get_option( self::LOCKDOWN_STATUS_OPTION, 'unknown' );
	}

	public static function quarantine_file( $abs_path, $rel_path, array $detection ) {
		global $wpdb;

		if ( is_link( $abs_path ) ) {
			return false;
		}

		if ( ! self::ensure_quarantine_lockdown() ) {
			return false;
		}

		if ( ! is_readable( $abs_path ) ) {
			return false;
		}

		$hash  = hash_file( 'sha256', $abs_path );
		$size  = filesize( $abs_path );
		$mtime = gmdate( 'Y-m-d H:i:s', filemtime( $abs_path ) );
		$perms = substr( sprintf( '%o', fileperms( $abs_path ) ), -4 );

		$dir = self::quarantine_dir();
		do {
			$filename = 'q-' . wp_generate_password( 24, false, false ) . '.bin';
			$target   = trailingslashit( $dir ) . $filename;
		} while ( file_exists( $target ) );

		$moved = @rename( $abs_path, $target ); // phpcs:ignore WordPress.PHP.NoSilencedErrors
		if ( ! $moved ) {
			return false;
		}

		$now = current_time( 'mysql', true );

		$wpdb->insert(
			Argus_DB::table( 'quarantine' ),
			array(
				'original_path'       => $rel_path,
				'quarantine_filename' => $filename,
				'original_filename'   => basename( $rel_path ),
				'file_size'           => $size,
				'file_hash'           => $hash,
				'original_mtime'      => $mtime,
				'original_perms'      => $perms,
				'detection_engine'    => $detection['engine'],
				'detection_rule'      => $detection['rule'] ?? null,
				'detection_type'      => $detection['type'],
				'severity'            => $detection['severity'],
				'status'              => self::STATUS_QUARANTINED,
				'quarantined_at'      => $now,
			),
			array( '%s', '%s', '%s', '%d', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s' )
		);

		$id = (int) $wpdb->insert_id;

		Argus_Events::record(
			'quarantine_added',
			'high',
			sprintf( 'Quarantined %s (%s)', $rel_path, $detection['engine'] ),
			array( 'quarantine_id' => $id, 'original_path' => $rel_path, 'detection_type' => $detection['type'] )
		);

		return array( 'id' => $id, 'hash' => $hash, 'quarantine_filename' => $filename );
	}

	protected static function store_path( $row ) {
		return trailingslashit( self::quarantine_dir() ) . $row->quarantine_filename;
	}

	public static function restore( $id ) {
		$row = self::get( $id );
		if ( ! $row || self::STATUS_QUARANTINED !== $row->status ) {
			return array( 'success' => false, 'message' => __( 'That item is not currently quarantined.', 'argus-wordpress-defence' ) );
		}

		$store_path = self::store_path( $row );
		if ( ! file_exists( $store_path ) ) {
			return array( 'success' => false, 'message' => __( 'The quarantined file is missing from the quarantine store.', 'argus-wordpress-defence' ) );
		}

		$content = file_get_contents( $store_path ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		list( $score, $matched ) = Argus_Malware_Scanner::score_content( (string) $content );

		global $wpdb;

		if ( $score >= Argus_Malware_Scanner::THRESHOLD_MEDIUM ) {
			$wpdb->update(
				Argus_DB::table( 'quarantine' ),
				array( 'restore_attempts' => (int) $row->restore_attempts + 1 ),
				array( 'id' => $row->id ),
				array( '%d' ),
				array( '%d' )
			);
			return array(
				'success' => false,

				'message' => __( 'Restore cancelled -- the restored file still triggers the security engine.', 'argus-wordpress-defence' ),
			);
		}

		$abs_original = ABSPATH . ltrim( $row->original_path, '/' );
		if ( file_exists( $abs_original ) ) {
			return array( 'success' => false, 'message' => __( 'A file already exists at the original location.', 'argus-wordpress-defence' ) );
		}

		$moved = @rename( $store_path, $abs_original ); // phpcs:ignore WordPress.PHP.NoSilencedErrors
		if ( ! $moved ) {
			return array( 'success' => false, 'message' => __( 'Could not move the file back to its original location.', 'argus-wordpress-defence' ) );
		}

		if ( $row->original_perms ) {
			@chmod( $abs_original, octdec( $row->original_perms ) ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_chmod, WordPress.PHP.NoSilencedErrors
		}

		$now = current_time( 'mysql', true );
		$wpdb->update(
			Argus_DB::table( 'quarantine' ),
			array( 'status' => self::STATUS_RESTORED, 'resolved_at' => $now, 'restore_attempts' => (int) $row->restore_attempts + 1 ),
			array( 'id' => $row->id ),
			array( '%s', '%s', '%d' ),
			array( '%d' )
		);

		Argus_Malware_Scanner::mark_restored_trusted( $row->original_path, hash_file( 'sha256', $abs_original ) );

		if ( $row->finding_id ) {
			Argus_Findings::set_status( $row->finding_id, Argus_Findings::STATUS_RESOLVED );
		}

		Argus_Events::record(
			'quarantine_restored',
			'info',
			sprintf( 'Restored %s from quarantine', $row->original_path ),
			array( 'quarantine_id' => $row->id, 'original_path' => $row->original_path, 'score' => $score )
		);

		return array(
			'success' => true,

			'message' => __( 'Restored -- ARGUS\'s static-analysis engine found no suspicious patterns in the current content. This is not a guarantee the file is safe, only that it did not match ARGUS\'s known indicators.', 'argus-wordpress-defence' ),
		);
	}

	public static function delete( $id ) {
		global $wpdb;

		$row = self::get( $id );
		if ( ! $row || self::STATUS_QUARANTINED !== $row->status ) {
			return array( 'success' => false, 'message' => __( 'That item is not currently quarantined.', 'argus-wordpress-defence' ) );
		}

		$store_path = self::store_path( $row );
		if ( file_exists( $store_path ) && ! @unlink( $store_path ) ) { // phpcs:ignore WordPress.PHP.NoSilencedErrors
			return array( 'success' => false, 'message' => __( 'Could not delete the quarantined file.', 'argus-wordpress-defence' ) );
		}

		$now = current_time( 'mysql', true );
		$wpdb->update(
			Argus_DB::table( 'quarantine' ),
			array( 'status' => self::STATUS_DELETED, 'resolved_at' => $now ),
			array( 'id' => $row->id ),
			array( '%s', '%s' ),
			array( '%d' )
		);

		if ( $row->finding_id ) {
			Argus_Findings::set_status( $row->finding_id, Argus_Findings::STATUS_RESOLVED );
		}

		Argus_Events::record(
			'quarantine_deleted',
			'info',
			sprintf( 'Permanently deleted quarantined file: %s', $row->original_path ),
			array( 'quarantine_id' => $row->id, 'original_path' => $row->original_path )
		);

		return array( 'success' => true, 'message' => __( 'Permanently deleted.', 'argus-wordpress-defence' ) );
	}

	public static function analyse( $id ) {
		global $wpdb;

		$row = self::get( $id );
		if ( ! $row ) {
			return array( 'success' => false, 'message' => __( 'Quarantine item not found.', 'argus-wordpress-defence' ) );
		}

		$store_path = self::store_path( $row );
		if ( ! file_exists( $store_path ) ) {
			return array( 'success' => false, 'message' => __( 'The quarantined file is missing from the quarantine store.', 'argus-wordpress-defence' ) );
		}

		$content = file_get_contents( $store_path ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		list( $score, $matched ) = Argus_Malware_Scanner::score_content( (string) $content );

		$wpdb->update(
			Argus_DB::table( 'quarantine' ),
			array(
				'confidence_score' => $score,
				'matched_rules'    => wp_json_encode( wp_list_pluck( $matched, 'id' ) ),
				'analysed_at'      => current_time( 'mysql', true ),
			),
			array( 'id' => $row->id ),
			array( '%d', '%s', '%s' ),
			array( '%d' )
		);

		return array( 'success' => true, 'score' => $score, 'matched' => $matched );
	}

	public static function get( $id ) {
		global $wpdb;
		$table = Argus_DB::table( 'quarantine' );
		return $wpdb->get_row( $wpdb->prepare( "SELECT * FROM {$table} WHERE id = %d", $id ) ); // phpcs:ignore
	}

	const PER_PAGE = 10;

	public static function paginated( $page = 1, $status = null, $per_page = self::PER_PAGE ) {
		global $wpdb;
		$table  = Argus_DB::table( 'quarantine' );
		$page   = max( 1, (int) $page );
		$offset = ( $page - 1 ) * $per_page;

		if ( $status ) {
			$total = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM {$table} WHERE status = %s", $status ) ); // phpcs:ignore
			$rows  = $wpdb->get_results(
				$wpdb->prepare( "SELECT * FROM {$table} WHERE status = %s ORDER BY quarantined_at DESC LIMIT %d OFFSET %d", $status, $per_page, $offset ) // phpcs:ignore
			);
		} else {
			$total = (int) $wpdb->get_var( "SELECT COUNT(*) FROM {$table}" ); // phpcs:ignore
			$rows  = $wpdb->get_results(
				$wpdb->prepare( "SELECT * FROM {$table} ORDER BY quarantined_at DESC LIMIT %d OFFSET %d", $per_page, $offset ) // phpcs:ignore
			);
		}

		foreach ( $rows as &$row ) {
			$row->matched_rules = $row->matched_rules ? json_decode( $row->matched_rules, true ) : array();
		}

		return array(
			'rows'        => $rows,
			'total'       => $total,
			'total_pages' => max( 1, (int) ceil( $total / $per_page ) ),
			'page'        => $page,
		);
	}

	public static function count_open() {
		global $wpdb;
		$table = Argus_DB::table( 'quarantine' );
		return (int) $wpdb->get_var(
			$wpdb->prepare( "SELECT COUNT(*) FROM {$table} WHERE status = %s", self::STATUS_QUARANTINED ) // phpcs:ignore
		);
	}

	public static function counts_by_status() {
		global $wpdb;
		$table = Argus_DB::table( 'quarantine' );
		$rows  = $wpdb->get_results( "SELECT status, COUNT(*) AS cnt FROM {$table} GROUP BY status" ); // phpcs:ignore

		$out = array( self::STATUS_QUARANTINED => 0, self::STATUS_RESTORED => 0, self::STATUS_DELETED => 0 );
		foreach ( $rows as $row ) {
			if ( isset( $out[ $row->status ] ) ) {
				$out[ $row->status ] = (int) $row->cnt;
			}
		}
		return $out;
	}

	public static function legacy_count() {
		$uploads = wp_get_upload_dir();
		$dir     = $uploads['basedir'] ?? '';
		if ( ! $dir || ! is_dir( $dir ) ) {
			return 0;
		}

		$count    = 0;
		$suffix   = Argus_Malware_Scanner::QUARANTINE_SUFFIX;
		$iterator = new RecursiveIteratorIterator(
			new RecursiveDirectoryIterator( $dir, FilesystemIterator::SKIP_DOTS ),
			RecursiveIteratorIterator::LEAVES_ONLY
		);
		foreach ( $iterator as $file ) {
			if ( $file->isFile() && $suffix === substr( $file->getFilename(), -strlen( $suffix ) ) ) {
				$count++;
			}
		}
		return $count;
	}
}