I'm contemplating the construction of an interface for advanced or dedicated users of a database, with a text box in which they type their queries as XQuery modules. (Non-advanced and non-dedicated users will make do with a variety of pre-defined queries; this interface is intended to provide an open-ended query interface for the few users who will need it.)
One issue that arises is security: any use of an eval() function opens the door to code injection attacks. For now, I'm inclined to think that BaseX's rule that xquery:eval() does not accept updating expressions suffices to protect the database from harm. Parsing the query and declining potentially harmful queries is also a possibility, if I can persuade myself I can distinguish harmful from harmless queries. (Comments and advice on this topic welcome, even though it's not the focus of this question.) A second issue is resource usage. Imagine a hostile user who writes a query designed to tie up the server for a long time and consume a lot of memory. Or imagine a non-hostile but naive user who unintentionally concocts an extremely expensive query. Is there a way to put a call to eval() (or any call to the BaseX HTTP server) into some kind of box and specify limits on the amount of CPU time, the amount of clock time, and/or the amount of storage to be available for its evaluation? Michael -- **************************************************************** * C. M. Sperberg-McQueen, Black Mesa Technologies LLC * http://www.blackmesatech.com * http://cmsmcq.com/mib * http://balisage.net **************************************************************** _______________________________________________ BaseX-Talk mailing list BaseX-Talk@mailman.uni-konstanz.de https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk
