- From: Adam Barth <w3c@adambarth.com>
- Date: Wed, 17 Oct 2012 09:17:35 -0700
- To: Fred Andrews <fredandw@live.com>
- Cc: Dan Veditz <dveditz@mozilla.com>, "public-webappsec@w3.org" <public-webappsec@w3.org>
What servers can depend on relates to what's implemented by popular user agents, not what the spec requires. Adam On Wed, Oct 17, 2012 at 3:49 AM, Fred Andrews <fredandw@live.com> wrote: > Hi Dan, > > Just to clarify, when reporting is required the server can depend on the > absence > of a report when it trips its own policy to signal that the UA has not > implemented > the policy. If reporting is opt-in the server can not depend on the > absence of > a report to signal that the UA has not implemented a policy - it could just > indicate > that the UA has decided not to send the report. > > cheers > Fred > >> Date: Tue, 16 Oct 2012 18:35:10 -0700 >> From: dveditz@mozilla.com >> To: fredandw@live.com >> CC: public-webappsec@w3.org >> Subject: Re: CSP 1.0: Are UAs permitted to implement reporting as opt-in? > >> >> On 10/16/12 3:36 PM, Fred Andrews wrote: >> > CSP 1.0 required a UA to submit a report when requested by the server >> > and thus that a server could depend on this. >> >> Servers can't rely on anything. The client might not support CSP at all. >> The client might partially support a non-standard predecessor of the >> approved CSP spec (e.g. Firefox 4). The user might have turned off CSP >> support. >> >> CSP cannot be relied on to turn an insecure site into a secure site; the >> site author still must strive to make their site secure. CSP provides a >> syntax by which a server can specify constraints it expects its content >> to follow so that a UA can provide some backup defense in depth in the >> face of bugs or attacks. But servers absolutely cannot rely on the >> client doing this. >> >> In the most trivial of examples: even if the client fully enforces the >> spec with no user modifications, if the content is not served over SSL >> the CSP policy itself might be stripped from the content before it >> reaches the client. The server should not rely on reports. >> >> -Dan Veditz >>
Received on Wednesday, 17 October 2012 16:18:37 UTC