CSP nonces are a feature available with CSP v2. Basically instead of saying "JS resources from the same domain are ok to be served" we now say "Ressources from everywhere are allowed as long as they add a `nonce` attribute to the script tag with the right nonce.
At the moment the nonce is basically just a `<?php p(base64_encode($_['requesttoken'])) ?>`, we have to decode the requesttoken since `:` is not an allowed value in the nonce. So if somebody does on their own include JS files (instead of using the `addScript` public API, they now must also include that attribute.)
IE does currently not implement CSP v2, thus there is a whitelist included that delivers the new CSP v2 policy to newer browsers. Check http://caniuse.com/#feat=contentsecuritypolicy2 for the current browser support list. An alternative approach would be to just add `'unsafe-inline'` as well as `'unsafe-inline'` is ignored by CSPv2 when a nonce is set. But this would make this security feature unusable at all in IE. Not worth it at the moment IMO.
Implementing this offers the following advantages:
1. **Security:** As we host resources from the same domain by design we don't have to worry about 'self' anymore being in the whitelist
2. **Performance:** We can move oc.js again to inline JS. This makes the loading way quicker as we don't have to load on every load of a new web page a blocking dynamically non-cached JavaScript file.
If you want to toy with CSP see also https://csp-evaluator.withgoogle.com/
Signed-off-by: Lukas Reschke <lukas@statuscode.ch>
Moves the update notification code in a single app. This is required since we want to use SSO for the new updater and for this have some code running in ownCloud as well (and we don't want that in core neccessarily). This app can provide that in the future, right now it's only the update notification itself. Will continue working on the SSO right away but wanted to keep the PR small.
Furthermore also makes some more code unit-testable...
In case the update server may deliver malicious content this would allow an adversary to inject arbitrary HTML into the response. So very bad stuff.
While signing the response would be better and something we can also do in the future (considering the code signing work), this is already a good first start.
* instead of a static rendering inside PHP use the
JS OC.Notification.showTemporary to hide the
notification after 7 seconds automatically
* fixes#14811
