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

On 08/16/2016 07:46 PM, Mark Watson wrote:
>
>
> On Tue, Aug 16, 2016 at 10:36 AM, Harry Halpin <hhalpin@w3.org
> <mailto: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
>     <mailto: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.​

I really do appreciate the work by this WG to compensate, but I do not
think they are sufficient without 'off by default.' We can agree to
disagree here, and let the WG make a decision and pass it to the
Director. In that case, the FO still stands.
>  
>
>     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.​
>  

Agreed. However, the DMCA provides a 'chilling effect' on security
audits and research on DRM systems in general, regardless of the
particular details of an audit or research.

>
>     >
>     >> 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
>     <https://en.wikipedia.org/wiki/Digital_Millennium_Copyright_Act#Criticisms>
>     >>
>     >>>
>     >>>> On Aug 16, 2016, at 4:28 , Harry Halpin <hhalpin@w3.org
>     <mailto: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
>     <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
>     <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
>     <https://github.com/w3c/encrypted-media/issues/304>
>     >>>>
>     >>>> Thus, my formal objection still stands.
>     >>>>
>     >>>>  cheers,
>     >>>>      harry
>     >>>>
>     >>>>>
>     >>>>> From: Harry Halpin [mailto:hhalpin@w3.org
>     <mailto:hhalpin@w3.org>]
>     >>>>> Sent: Tuesday, August 2, 2016 5:00 AM
>     >>>>> To: public-html-media@w3.org <mailto: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
>     <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
>     <https://dev.w3.org/html5/status/formal-objection-status.html>
>     >>>>>
>     >>>>> From: Harry Halpin [mailto:hhalpin@w3.org
>     <mailto:hhalpin@w3.org>]
>     >>>>> Sent: Monday, August 1, 2016 6:42 PM
>     >>>>> To: public-html-media@w3.org <mailto: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
>     <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
>     <https://en.wikipedia.org/wiki/Digital_rights_management#Opposition_to_DRM>
>     >>>>> [3]
>     https://en.wikipedia.org/wiki/Digital_rights_management#Shortcomings
>     <https://en.wikipedia.org/wiki/Digital_rights_management#Shortcomings>
>     >>>>> [4]
>     https://www.w3.org/TR/geolocation-API/#implementation_considerations
>     <https://www.w3.org/TR/geolocation-API/#implementation_considerations>
>     >>>>> [5] https://w3c.github.io/encrypted-media/
>     <https://w3c.github.io/encrypted-media/>
>     >>>>>
>     >>> David Singer
>     >>> Manager, Software Standards, Apple Inc.
>     >>>
>     >>
>     >>
>     > David Singer
>     > Manager, Software Standards, Apple Inc.
>     >
>
>
>

Received on Tuesday, 16 August 2016 17:50:33 UTC