On Jan 24, 2011, at 6:54 PM, Kyle Sluder wrote: > On Jan 24, 2011, at 6:02 PM, Matt Neuburg <m...@tidbits.com> wrote: > >> >> (2) A common trick is make the text file a format string (i.e., containing a >> lot of %@) and just hand it to stringWithFormat along with all the >> substitutions. Badda bing badda boom. > > This is how security vulnerabilities are born. You are handing off formatting > strings to functions that trust you are supplying the correct number and type > of arguments to match, or else they will blithely access random chunks of > memory. > > If you are at all accepting arbitrary input files, you must not simply hand > the text over as a formatting specifier. Even if you're building an iOS app > and bundling all the possible files yourself, do yourself a favor and build a > more robust parser now. > > There's no sense in writing intentionally fragile code that will (not "may") > result in a crasher and irate customers sometime in the future when someone > accidentally puts one to many %@ sequences in the MadLib file. >
This is madlibs; the template string comes from him, the programmer. Only the words that go into the blanks come from the user. You'll need to prove to me that performing the substitution this way is any more dangerous than substituting words from the user into the template string some other way. m. -- matt neuburg, phd = m...@tidbits.com, http://www.tidbits.com/matt/ pantes anthropoi tou eidenai oregontai phusei Among the 2007 MacTech Top 25, http://tinyurl.com/2rh4pf AppleScript: the Definitive Guide, 2nd edition http://www.tidbits.com/matt/default.html#applescriptthings Take Control of Exploring & Customizing Snow Leopard http://tinyurl.com/kufyy8 RubyFrontier! http://www.apeth.com/RubyFrontierDocs/default.html TidBITS, Mac news and reviews since 1990, http://www.tidbits.com _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
