Re: Formal objection to Encrypted Media Extensions progressing to Proposed Recommendation without greater user protection

On Tue, Aug 16, 2016 at 10:36 AM, Harry Halpin <hhalpin@w3.org> wrote:

>
>
> On 08/16/2016 07:28 PM, David Singer wrote:
> >> On Aug 16, 2016, at 10:22 , Harry Halpin <hhalpin@w3.org> wrote:
> >>
> >>
> >>
> >> On 08/16/2016 06:35 PM, David Singer wrote:
> >>> I think you’ll need to explain why the choice of how much, and how,
> the user is warned, needs to be made by you/us, and not by the browser
> maker.  You also haven’t given details of the ‘user harm’ you talk about
> for EME itself.
> >> The details of 'user harm' are adequately explained by the concerns over
> >> the DMCA and the use of DRM that have been well-documented elsewhere
> >> [1].
> > No, those criticisms were almost exclusively focused on the risk to
> security researchers. Not one of the sub-headings you link to appears to
> apply to users.  Current politics notwithstanding, repeatedly stating
> something doesn’t intrinsically make it true.
>
> I don't agree.  Insofar as security researchers cannot audit the
> security of DRM systems, then it is *users* who will face any harm due
> to the lack of security audits. That is a unique feature of DRM that EME
> enables. EME can also, due to clearkey, be considered a DMCA-compliant
> system itself (i.e. clearKey's Key System is equivalent to a CDM).
>
> >
> >> Any installation or use of software that is compliant with the DMCA
> >> can be considered a risk to users and security researchers as is noted
> >> on WIkipedia [1].
> > Users and security researchers are not the same people.
>
> See above.
>
> >
> >> Although the FO is filed as an individual, one task of W3C is to assure
> >> there is representation of the interest of users and to ensure the Web
> >> is secure.
> > Sure, but you need to say what the *user* harm is.
>
> If there is a part of a browser that makes security research difficult
> and possibly illegal,  then that part of the browser is rather
> self-evidently dangerous to end-users.


​Unless the browser implementor takes additional measures to compensate for
that difficulty / possible illegality.​


> While I appreciate the effort,
> sandboxing may help but there is no such thing as a perfect sandbox.
>

​There is no such thing as a perfect security audit either. We're talking
about different kinds of risk reduction.​


>
> >
> >> So, I think the decision should be made by the Working Group
> >> with the best interests of users in mind, not just the browser makers.
> >> While you can consider 'off by default' to be unreasonable, I think if
> >> one takes that this same approach has been adopted by similarly
> >> controversial APIs (Geolocation API), I think it's quite reasonable.
> >>
> >>   cheers,
> >>        harry
> >>
> >> [1]
> >> https://en.wikipedia.org/wiki/Digital_Millennium_Copyright_
> Act#Criticisms
> >>
> >>>
> >>>> On Aug 16, 2016, at 4:28 , Harry Halpin <hhalpin@w3.org> wrote:
> >>>>
> >>>>
> >>>>
> >>>> On 08/13/2016 05:05 PM, Paul Cotton wrote:
> >>>>> Note that I am responding to an email and proposal from Harry from
> earlier in this thread.
> >>>>> https://lists.w3.org/Archives/Public/public-html-media/
> 2016Aug/0005.html
> >>>>>
> >>>>>> The text I would add to the EME spec would be similar:
> >>>>>> "A conforming implementation of this specification MUST ensure that
> this
> >>>>>> API cannot be used without the user's express permission due to the
> >>>>>> inherent risks in the activation of a CDM in a user agent. The API
> MUST
> >>>>>> be disabled by default, and should only be activated when the user
> gives
> >>>>>> express consent and is fully informed on a per-origin basis."
> >>>>> This request would appear to be (at least partially) covered by the
> existing text in the EME CR:
> >>>>> http://www.w3.org/TR/encrypted-media/#navigator-extension-
> requestmediakeysystemaccess
> >>>>>
> >>>>> 3.1.1 Methods
> >>>>> requestMediaKeySystemAccess
> >>>>> Note
> >>>>>
> >>>>> Calling this method may have user-visible effects, including
> requests for user consent. This method should only be called when the
> author intends to create and use a MediaKeys object with the provided
> configuration.
> >>>>> Requests access to the specified Key System. When
> supportedConfigurations is specified, the configuration specified by at
> least one of its elements must be supported. The resulting
> MediaKeySystemAccess will correspond to the first such element.
> >>>>> Any permission checks or user interaction, such as a prompt, MUST be
> performed before resolving the promise.
> >>>>> Were you aware of this text in the EME specification?  Can you live
> with the current text since changing this text to be normative and changing
> it to a MUST (I believe) would be a “breaking change” and would require
> that we re-publish another EME CR?
> >>>>>
> >>>>> /paulc
> >>>>> HME WG Chair
> >>>> Paul,
> >>>>
> >>>> Thanks for noting 'use-visible effects' but it does not either
> explicitly 1) require a user-visible effect for fully informing the user"
> and "gaining their consent" as well "turning off EME by default". Simply
> put, the text you are noting says MAY have user-visible effects and as so
> is too weak to include in a test-suite or support EME being off by default.
> So, it does not cover my objection, which normatively requires much
> stronger text, including "off by default". So, no I can't live with that
> text and require the change (or a semantically equivalent one) that I
> suggest in the github repo and e-mail list:
> >>>>
> >>>> https://github.com/w3c/encrypted-media/issues/304
> >>>>
> >>>> Thus, my formal objection still stands.
> >>>>
> >>>>  cheers,
> >>>>      harry
> >>>>
> >>>>>
> >>>>> From: Harry Halpin [mailto:hhalpin@w3.org]
> >>>>> Sent: Tuesday, August 2, 2016 5:00 AM
> >>>>> To: public-html-media@w3.org
> >>>>> Subject: Re: Formal objection to Encrypted Media Extensions
> progressing to Proposed Recommendation without greater user protection
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>> On 08/02/2016 03:00 AM, Paul Cotton wrote:
> >>>>>> An individual who registers a Formal Objection should cite
> technical arguments and propose changes that would remove the Formal
> Objection;
> >>>>> http://www.w3.org/2015/Process-20150901/#WGArchiveMinorityViews
> >>>>>
> >>>>> Before I record your formal objection at [1] I would like to ensure
> that your “proposed change” for your objection is understood.
> >>>>>> There is prior art in HTML for similarly powerful and
> privacy-invasive features such as the Geolocation API [4]. Thus, there
> should be no procedural problem in requiring user consent and disabling EME
> by default in all browsers.
> >>>>> The reference you provide as a “prior art” precedent in [4] is in a
> non-normative section of Geolocation API and it does NOT disable the
> Geolocation API by default.  Can you explain why you think this reference
> is useful here?  Are you suggesting similar text be added to EME?  If so
> could you suggest exact text that would remove your formal objection?
> >>>>>
> >>>>> The exact phrasing is " A conforming implementation of this
> specification must provide a mechanism that protects the user's privacy and
> this mechanism should ensure that no location information is made available
> through this API without the user's express permission"
> >>>>>
> >>>>> To clarify, I agree that the spec should have used capitalization: "
> A conforming implementation of this specification MUST provide a mechanism
> that protects the user's privacy and this mechanism should ensure that no
> location information is made available through this API without the user's
> express permission."
> >>>>>
> >>>>> However, I do believe that all browsers *do* indeed ask for user
> consent before using the Geolocation API and that it is disabled by
> default, which is clear prior art for EME. This is indeed the case on the
> browsers I use, but if others activate Geolocation API without user
> consent, please do inform me, as I don't use Microsoft products.
> >>>>>
> >>>>> The text I would add to the EME spec would be similar:
> >>>>>
> >>>>> "A conforming implementation of this specification MUST ensure that
> this API cannot be used without the user's express permission due to the
> inherent risks in the activation of a CDM in a user agent. The API MUST be
> disabled by default, and should only be activated when the user gives
> express consent and is fully informed on a per-origin basis."
> >>>>>
> >>>>> Given there is already a place where user consent MUST be asked in
> the EME spec (" User agents must ensure that users are fully informed
> and/or give explicit consent before Distinctive Identifier(s) are exposed,
> such as in messages from the Key System implementation"), there is no
> reason why this MUST can't be broadened. I would also remove the "or." The
> user must be fully informed AND give explicit consent.
> >>>>>
> >>>>> Furthermore, given this normative, testing for express user consent
> on a per-origin basis should be part of the test-suite.
> >>>>>
> >>>>>       cheers,
> >>>>>               harry
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>> /paulc
> >>>>> HME WG Chair
> >>>>>
> >>>>> [1] https://dev.w3.org/html5/status/formal-objection-status.html
> >>>>>
> >>>>> From: Harry Halpin [mailto:hhalpin@w3.org]
> >>>>> Sent: Monday, August 1, 2016 6:42 PM
> >>>>> To: public-html-media@w3.org
> >>>>> Subject: Formal objection to Encrypted Media Extensions progressing
> to Proposed Recommendation without greater user protection
> >>>>>
> >>>>> [Note this is a formal objection as an individual in a private
> capacity, not on behalf of my organization]
> >>>>>
> >>>>> I'd like to fill a formal objection against Encrypted Media
> Extensions progressing to Proposed Recommendation status without adequate
> protection for users.
> >>>>>
> >>>>> I believe that this work is so problematic given the well-known and
> well-documented problems with DRM,  it should not happen as a standard at
> all at W3C. That being said, for reasons which I do not agree with and hope
> he reconsiders, the Director has approved both the scope of the charter and
> the move of the Working Draft to Candidate Recommendation.
> >>>>>
> >>>>> If it does happen, then it seems given the well-documented problems,
> some harm mitigation should be pursued. The security research community has
> broad support for the EFF covenant being a normative requirement [1].
> However, it appears consensus is not forthcoming on either EME itself or
> the EFF covenant, with the Technology and Policy IG also failing to gain
> any consensus for even further discussion (as it failed to even get
> chartered).
> >>>>>
> >>>>> To myself, the danger of EME is that over the last year suddenly
> over millions of people had a content decryption module installed without
> their explicit consent on their computer. For many users, such as those of
> Firefox, the DCM was installed via a silent update they had no control
> over. Such a content decryption module can serve as both a technical
> security risk, as it puts a highly privileged process in the user's
> computer outside their direct control by design, and as a legal risk
> subjects any inspection of the DRM-enabled system on their computer due to
> the anti-circumvention provision of the DMCA or local equivalent. Thus,
> regardless of whether or not one agrees with EME, it seems the *least* the
> W3C should do is warn the user about the installation and activation of a
> CDM on their machine - and that the CDM should not be installed and EME
> should not be activated without explicit user consent. Thus, in all
> configurations, EME should be *de-activated by default.*
> >>>>>
> >>>>> There is prior art in HTML for similarly powerful and
> privacy-invasive features such as the Geolocation API [4]. Thus, there
> should be no procedural problem in requiring user consent and disabling EME
> by default in all browsers.  While it can be argued many users will want to
> watch protected videos and will turn them on, just as many users will want
> to use Google Maps with Geolocation APIs, there does not seem to be a
> reasonable case for having such
> >>>>> powerful and possibly dangerous features enabled by default.
> >>>>>
> >>>>> Current language in the spec is so weak as it may not be enforced
> and so EME does not have to be disabled by default: " User Agents have some
> flexibility to determine whether consent is required for a specific
> configuration and whether such consent may also apply to other
> configurations. For example, consent to one configuration may also imply
> consent for less powerful, more restricted configurations. Equally, a
> denial of consent for one configuration may imply denial of consent for
> more powerful, less restricted configurations."
> >>>>>
> >>>>> The only place where the spec [5] makes normative statements around
> consent, but due to how DRM (i.e. Key Systems) are designed, it is unclear
> how the user agent should interpret these statements
> >>>>>
> >>>>> "If a user agent chooses to support a Key System implementation that
> cannot be sufficiently sandboxed or otherwise secured, the user agent
> should ensure that users are fully informed and/or give explicit consent
> before loading or invoking it."
> >>>>>
> >>>>> "User Agents should ensure that users are fully informed and/or give
> explicit consent before a Key System that presents security concerns that
> are greater than other user agent features (e.g. DOM content) may be
> accessed by an origin..."
> >>>>>
> >>>>> " User agents must ensure that users are fully informed and/or give
> explicit consent before Distinctive Identifier(s) are exposed, such as in
> messages from the Key System implementation."
> >>>>>
> >>>>> Although these statements show some progress towards trying to
> mitigate the dangers of DRM, given that DRM systems work in conjunction
> with anti-circumvention legislation that prevents a developer from knowing
> whether or not they can sufficiently sandboxed (or 'otherwise secured') and
> whether a Distinctive Identifier is used by the DRM system, so the use of
> EME will *always* present security concerns that are greater than the rest
> of the user agent features involving the Open Web Platform.
> >>>>>
> >>>>> Is the Working Group amendable to having EME and associated DRM
> systems (i.e. "Key Systems") *normatively* disabled by default in order to
> protect users?
> >>>>>
> >>>>>   cheers,
> >>>>>       harry
> >>>>>
> >>>>> [1] https://www.eff.org/deeplinks/2016/03/security-researchers-
> tell-w3c-protect-researchers-who-investigate-browsers
> >>>>> [2] https://en.wikipedia.org/wiki/Digital_rights_management#
> Opposition_to_DRM
> >>>>> [3] https://en.wikipedia.org/wiki/Digital_rights_management#
> Shortcomings
> >>>>> [4] https://www.w3.org/TR/geolocation-API/#
> implementation_considerations
> >>>>> [5] https://w3c.github.io/encrypted-media/
> >>>>>
> >>> David Singer
> >>> Manager, Software Standards, Apple Inc.
> >>>
> >>
> >>
> > David Singer
> > Manager, Software Standards, Apple Inc.
> >
>
>
>