Re: Prevent caching of pdf files
[email protected] (Peter Gutmann)
| Newsgroups | gmane.comp.security.programming |
|---|---|
| Message-ID | <[email protected]> |
bsec <[email protected]> writes: >Currently on a secure Internet application we use the "Cache-Control: No >Cache" header to prevent information from caching on client machines. Cache-Control is an HTTP 1.1 (meaning it'll be ignored by HTTP 1.0) indication that the cache shouldn't return a cached response without revalidating with the origin server. That is, it's intended to prevent caches from returning stale responses for (presumably) mutable data. It does not have the semantics that you require of it. What you want is no-store. (Even then, relying on the browser to prevent users from saving copies of the file to disk is unsound. At most you're getting an advisory please-don't- store-this). >however, there is a known issue with accessing pdf files with IE Yeah, it tends to crash a lot when you do this :-). Peter.