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Re: Attempt to use CSP - Questions

From: Aymeric Vitte <vitteaymeric@gmail.com>
Date: Thu, 26 Sep 2013 12:22:50 +0200
Message-ID: <52440AFA.4010705@gmail.com>
To: David Bruant <bruant.d@gmail.com>
CC: public-webappsec@w3.org
Answered on es-discuss for the first part.

Did you read the rest of the thread? The example is showing that I am 
opening eval and inline to Google scripts.

The concept of unsafe-inline was for the worker example which I thought 
could be interpreted as inline, but it is not.

Regards

Aymeric

Le 26/09/2013 11:37, David Bruant a écrit :
> Le 20/09/2013 18:21, Aymeric Vitte a écrit :
>> I have some doubts while reading the CSP spec, so sorry if the 
>> remarks have already been discussed. You might object that I am doing 
>> strange things but there are very good reasons for that, for example 
>> I can not load directly script.js inside https://peersm.com because 
>> FF will refuse to create a non SSL/TLS WebSocket (see 
>> https://bugzilla.mozilla.org/show_bug.cgi?id=917829)
> Firefox blocks mixed content.
> See https://developer.mozilla.org/en-US/docs/Security/MixedContent
>
> The idea is that if you deliver an HTTPS page, you expect security 
> guarantees. You expect your users to expect them as well. If the 
> browser loads HTTP resources, these are subject to MITM attacks, thus 
> un-securing the secure channel you set up with HTTPS.
>
> So if you start with HTTPS, be secure all the way, otherwise, you're 
> giving to your users a false sense of security.
>
>> What I would think natural to have is something like:
>>
>> style-src ('unsafe-inline' only with http://peersm.com/) or 
>> 'nonce-random'
>> --> allow unsafe-inline only for a set of urls or use nonces
>> script-src ('unsafe-eval' only with https://peersm.com/script.js) 
>> ('unsafe-inline' only with workers) https://www.google.com 
>> https://ajax.googleapis.com (https://peersm.com/script.js or 
>> 'nonce-random')
>> --> allow unsafe-eval only for a set of urls, whitelist them 
>> explicitely or use nonces
>>
>> But as far as I understand the spec this is not possible, correct?
> I don't think it is, but I also don't think you need any of that. CSP 
> allows you to choose initial sources. Which authority you want to 
> provide afterwards (eval) is up to you. More precisely, it's up to the 
> policy your describe as code in the whitelisted sources.
>
> I don't understand the idea of per-domain unsafe-inline whitelists. If 
> something is inline (<style> <script>), it's in your HTML page, there 
> is no notion of domain.
>
> David

-- 
Peersm : http://www.peersm.com
node-Tor : https://www.github.com/Ayms/node-Tor
GitHub : https://www.github.com/Ayms
Received on Thursday, 26 September 2013 10:23:25 UTC

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