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From Chuck Lantz <cla...@microsoft.com>
Subject RE: Proposal for CSP support
Date Wed, 25 Feb 2015 01:01:05 GMT
Yeah that was what I was hoping as well.  Is there a specific reason why we wouldn't just map
the existing <access> element into the new plugin?  From what I can gather it would
cover both scenarios (nav+intent).  Basically you can then have the same config.xml contents
and installing "legacy-whitelist" results in the old behavior while "new-whitelist" (or whatever)
covers the new behavior.  Certainly makes things easier for situations where developers want
to simply take an existing app and make it more secure using CSP+new whitelist... particularly
if the legacy-whitelist gets dropped either now or sometime in the future.

-Chuck

-----Original Message-----
From: agrieve@google.com [mailto:agrieve@google.com] On Behalf Of Andrew Grieve
Sent: Tuesday, February 24, 2015 12:15 PM
To: dev
Subject: Re: Proposal for CSP support

Definitely hoping that we can have all platforms use the same primitives.
Ian's intent and navigation whitelists work on Android and iOS atm I believe.

On Tue, Feb 24, 2015 at 1:31 PM, Chuck Lantz <clantz@microsoft.com> wrote:

> I asked Kevin Hill from the Windows team working on the security model 
> for Windows apps in Windows 10 to take a look at the document 
> reference below for commentary given his experience in this area 
> (including W3C involvement).  He added a few comments to the doc.
>
> Andrew, is your proposal intended to be Android specific or are you 
> proposing that elements like allow-navigation be introduced for iOS 
> and other platforms as well?
>
> -Chuck
>
> -----Original Message-----
> From: agrieve@google.com [mailto:agrieve@google.com] On Behalf Of 
> Andrew Grieve
> Sent: Tuesday, February 24, 2015 7:59 AM
> To: dev
> Subject: Re: Proposal for CSP support
>
> I'm not sure allowing plugins to modify an apps security policy is a 
> good idea because CSP only really works when the dev understands it 
> and puts thought into it.
>
> A build step for CSP might be tricky because we don't actually know 
> which .html files might be navigated to (as opposed to XHR'ed for 
> templates). It could also be that some pages need different CSP than others.
>
> So, with Ian's whitelist changes
> - We disallow apps from navigating, openExteral, and XHR'ing by 
> default
> - If they want the <access> behaviour back, they can install the 
> legacy-whitelist plugin.
>
> Question is, what do we want them to actually do?
> Right now there's two new whitelist plugins:
>   - navigation-whitelist & intent-whitelist
>   - They look for <allow-navigation> and <allow-intent> respectively
>   - Neither of these actually open up all network access.
>
> I'd like to propose that for simplicity, we have only one "new" 
> whitelist plugin that:
>   - Does what navigation-whitelist & intent-whitelist do
>   - Opens up all network requests on the native side
>   - Has JS that runs on start-up that alert()s if no CSP meta tag is 
> present.
>       - It should recommend adding in the CSP that is used in the 
> default app template as a start
>
> This should cover 99% of use-cases (people shouldn't need to write 
> their own whitelist plugins), and (I hope) will be simple enough to 
> figure out without reading too much documentation.
>
>
>
>
> On Fri, Feb 20, 2015 at 5:12 PM, Jason Chase <chasej@chromium.org> wrote:
>
> > Chuck,
> >
> > Thanks for the feedback, it's good to know others are interested in CSP.
> >
> > I've created a doc to capture the proposal in a little more detail, 
> > and allow for more robust comments:
> >
> > https://docs.google.com/document/d/1sfFs6LB1_giodyR4QwBMQssLKP_UxACZ
> > if
> > k-VYVX2T8/edit?usp=sharing
> >
> > In that doc, I've attempted to address the questions/comments both 
> > from your email, as well as Michal's earlier response.  I'll let all 
> > interested parties continue the conversation in the doc.
> >
> > Thanks,
> > Jason
> >
> > On 20 February 2015 at 10:54, Chuck Lantz <clantz@microsoft.com> wrote:
> >
> > > Hey Jason - Glad to see this proposal!  A number of us at 
> > > Microsoft have been talking along these same lines actually. 
> > > Windows 10 apps will
> > include
> > > CSP support as the latest version of IE has support so I'd say 
> > > we're completely in support of moving Cordova apps down this path.  
> > > In fact I'd want to make sure that any CSP related metadata tag 
> > > injection also
> > applied
> > > to the Windows platform as well.
> > >
> > > A few of thoughts:
> > >
> > > 1. I definitely know there is quite a bit of interest still in 
> > > being able to enable hosted (https accessed and controlled by the
> > > developer) app content access Cordova device APIs (which is 
> > > currently a shortcoming of Windows 8.0/8.1 apps so we hear about 
> > > it quite a bit).  As a result,
> > we'll
> > > want to be sure Cordova doesn't inhibit this use case at a base level.
> > > That said, having a default CSP policy that restricts hosted in 
> > > the template is fine and would promote secure practices since you 
> > > need to exercise caution when mixing in any remote content even 
> > > when you control
> > it
> > > completely.  Also agree with inline being high risk.
> > >
> > > 2. Re: Long term, one thing that CSP doesn't cover well is which 
> > > URIs should be granted elevated device access. Given hosted 
> > > content with
> > plugin
> > > device API access is still a scenario we'll need to consider, 
> > > perhaps we should consider using the config.xml <access> element 
> > > to represent URIs that have device API access (beyond standard 
> > > browser access).  Otherwise
> > we
> > > get into a bit of an "all or nothing" situation as it pertains to 
> > > hosted app content which poses a larger security risk if you opt 
> > > to extend
> > device
> > > API access beyond local content. (It also strikes me this is a 
> > > general
> > gap
> > > in the web standard as a whole.)
> > >
> > > 3. Eval is actually a bit tougher - I know when we've look at this 
> > > in the past it impacted JS frameworks far more than inline did.
> > > (Ex: With
> > Angular
> > > you can stop using eval but you take a perf hit which is a bigger 
> > > deal on mobile than desktop.)  Definitely the most secure practice 
> > > - but it also could cause the default template to appear to "not 
> > > work."  If we omit the "unsafe-eval" directive in the CSP policy 
> > > in the template we'll want to
> > be
> > > crystal clear on how to alter it.  That could be solved with 
> > > proper documentation and blog posts though.
> > >
> > > 4. I'd suggest we also consider the new "browser" platform here 
> > > since Chrome/Firefox/IE (as of Win 10) have support. Should be 
> > > "free", but I'm guessing the metadata tag injection you mention is 
> > > something we could probably just do all-up rather than only for
> specific platforms.
> > >
> > > -Chuck
> > >
> > > -----Original Message-----
> > > From: mmocny@google.com [mailto:mmocny@google.com] On Behalf Of 
> > > Michal Mocny
> > > Sent: Thursday, February 19, 2015 2:25 PM
> > > To: dev
> > > Subject: Re: Proposal for CSP support
> > >
> > > Thanks for this clear outline.
> > >
> > > Jason, I know you've been working on the short-term items for a 
> > > while as part of your investigation, fixing things as you went -- 
> > > what is the current state of CSP support in platforms / plugins?
> > > What portion
> > already
> > > has fixes (or PR for them), what work is known but undone, and 
> > > what
> > hasn't
> > > been investigated much at all?
> > >
> > > -Michal
> > >
> > > On Thu, Feb 19, 2015 at 4:55 PM, Jason Chase <chasej@chromium.org>
> > wrote:
> > >
> > > > I'm interested in full-blown support for CSP (Content Security
> > > > Policy) in Cordova.  While we're close to having new and 
> > > > improved whitelist functionality, there are gaps in what the 
> > > > whitelist is able to protect against. In particular, inline 
> > > > script and eval() are higher risks that are not addressed by whitelists.
> > > >
> > > > Many Cordova apps may use only static content, or not include 
> > > > any third-party content.  However, there are certainly examples 
> > > > of apps that need to include user input/third-party content, 
> > > > mixed with the app's own HTML content.  In some cases, platforms 
> > > > may even restrict functionality (see [1]). I think CSP is a 
> > > > compelling answer for these scenarios, and for security in general for
apps.
> > > >
> > > > Assuming CSP support is valuable, the question is how to implement?
> > > > Support for CSP is not universal across platforms.  It is known 
> > > > to be supported on Android (KitKat and later), iOS (since 7.1), 
> > > > and
> Firefox.
> > > > Where supported, it is typically via a HTTP response header, or 
> > > > a META tag in the document.
> > > >
> > > > I've done some investigation into feasible approaches.  As a 
> > > > result, I'm proposing as below.
> > > >
> > > > Long term goal:
> > > > Cordova supports CSP in apps *and* plugins, and is 
> > > > enabled/secure by default.  Ideally, CSP rules can be 
> > > > configurable and automatically applied to all content (i.e. so 
> > > > developers can fall into the pit of
> > > > success)
> > > >
> > > > Achieving this goal will likely require incremental progress 
> > > > over a number of releases.  At a high level, first make changes 
> > > > so developers can manually apply CSP to their apps.  Longer 
> > > > term, add support for configurability and automatic application of CSP.
> > > >
> > > > Short term plan:
> > > > - Change new app template to contain CSP meta tag with a 
> > > > default, secure policy (i.e. no inline script, eval(), only 
> > > > local app
> > > > content)
> > > > - Remove any blockers to default policy from framework and core
> > plugins.
> > > > This would be a continuation of the work in CB-8210, applied to 
> > > > other platforms.  For example, this would fix any framework code 
> > > > that relies on sending javascript to be executed inline, from 
> > > > the native side
> > > > - Deprecate any framework APIs that allow less secure practices.
> > > > Many already are marked as deprecated (at least on Android)
> > > > - Update docs/samples to include CSP, and clearly state that use 
> > > > of inline javascript is deprecated
> > > >
> > > > Long term plan:
> > > > - In a future major release, remove the previously deprecated 
> > > > framework APIs
> > > > - Define/implement a configuration model for CSP rules
> > > > - Implement a build/package step to apply configured CSP rules 
> > > > to all content as meta tags.  Run-time support involves 
> > > > re-writing content, and/or intercepting resource requests.  The 
> > > > feasibility of intercepting requests is highly variable across 
> > > > platforms, at greater cost/complexity than build-time.
> > > >
> > > > I'm very interested in any comments on this proposal.  This 
> > > > includes questions around use cases (missing or otherwise), 
> > > > different requirements, technical concerns, .etc.
> > > >
> > > > Thanks,
> > > > Jason
> > > > Google Cordova Team
> > > >
> > > > [1] http://callback.markmail.org/thread/yxmmya2o2lc26tpi
> > > >
> > >
> >
>
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