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Re: Mandatory encryption

From: Mark Watson <watsonm@netflix.com>
Date: Wed, 18 Jul 2012 05:27:39 +0000
To: Phillip Hallam-Baker <hallam@gmail.com>
CC: Mike Belshe <mike@belshe.com>, Paul Hoffman <paul.hoffman@gmail.com>, "<grahame@healthintersections.com.au>" <grahame@healthintersections.com.au>, "ietf-http-wg@w3.org" <ietf-http-wg@w3.org>
Message-ID: <5EEB652E-FDA6-40B5-9FD2-D8B41664C300@netflix.com>
The problems with HTTP that HTTP/2.0 is intended to address seem to have nothing to do with security. Adding a requirement for use of TLS is unrelated to the purpose of the new protocol and will restrict its usage. See http://groups.csail.mit.edu/ana/Publications/PubPDFs/Tussle%20in%20Cyberspace%20Defining%20Tomorrows%20Internet%202005's%20Internet.pdf for why we should design protocols which flex along lines of controversy. This question of mandating TLS seems to go directly against that advice.

There are many services which make use of HTTP without TLS today that may find it more difficult to migrate to HTTP/2.0 if they also have to change their security approach as well. The benefits of HTTP/2,0, whilst they may be substantial, are likely not sufficient to be "worth the price" of such a change. As a specific example, Netflix ships quite a lot of traffic over HTTP without TLS, yet our service remains highly secure. Where we do use TLS we find significant problems with it - switching to TLS for all traffic would be an order-of-magnitude bigger deal (on the minus side) than the benefits of HTTP/2.0.

ůMark


On Jul 17, 2012, at 9:50 PM, Phillip Hallam-Baker wrote:

Perhaps you are not aware that I work for a CA and I have spent 20
years working on Web security, most of it developing the CA industry
and PKI infrastructure.

Maintaining the policies for accepting trust roots is essentially a
full time job for each of the parties doing it. It is not just a
matter of checking that a CA has a valid audit. The root manager has
to determine that the audit actually relates to the root of trust to
be included and that the practices adhered to meet the necessary
inclusion criteria.


Unlike a coding task, maintaining a root store is an ongoing
commitment. It is not something that you can do once and forget.



On Tue, Jul 17, 2012 at 11:51 PM, Mike Belshe <mike@belshe.com<mailto:mike@belshe.com>> wrote:


On Tue, Jul 17, 2012 at 8:32 PM, Phillip Hallam-Baker <hallam@gmail.com<mailto:hallam@gmail.com>>
wrote:

Umm pretty much every Web Server has SSL support, the issue is that
only about 2% of deployments turn it on. Or is the idea that we are
going to mandate turning it on? If so, who is going to define the
trust criteria for accepting certs?


Browsers already have well documented policies for this.  Major OSes also
have their own policies (MacOS, Windows).



I am a big supporter of TLS. I just don't see anything good coming
from a mandate that is superfluous.

As an example, we have had a mandate in PKIX to check CRLs and/or OCSP
for over a decade and to reject a certificate if the client cannot
perform validation. Most browsers try to check but accept the
certificate if there is no response to the OCSP request. So virtually
every deployed browser has been out of compliance with a fundamental
PKIX control for over a decade despite repeated attempts by the CAs to
persuade the providers to change this.

I can't see how DANE is going to solve anything either since DANE
poses an even more disruptive hard-fail criteria.

I don't want to tie an application layer protocol version to a
transport layer protocol version or vice versa. If you tie HTTP 2.0 to
TLS 1.2 then you are going to have to revise HTTP when you revise TLS.


This is not true.  HTTP did not change when we went from earlier versions of
TLS to the current versions.  Browsers do support older versions of TLS,
usually for older servers that haven't upgraded.  Even SSL3 - shudder.




I don't see any value in a Canute/sea act here.


What would be valuable is to have a suite of standards for a specific
application that could be identified as a set. Something like 'best
practices for Web server hosting, IPv6 +HTTP 2.0 + TLS 1.2 with
AES+SHA2 + DNSSEC'. It would also be nice to see a similar draft for
best practices for email clients and servers, and yes, support for
STARTTLS would be high on my list of requirements. A draft like that
would be very useful as a contract term for outsourcing Web hosting or
mail service.

But that is a totally different prospect to trying to tie HTTP to a
particular security solution.


Implementing TLS in a product is far from trivial. Getting the code is
easy, selecting trust anchors is not. Is the specification going to
mandate a particular choice of trust anchor? that is not going to
happen. Nor is defining a minimum Certification Policy or locking the
whole HTTP trust infrastructure to the ICANN PKI root by trying to
mandate DNSSEC and DANE as well as TLS.

TLS requires a PKI to work and every PKI comes with a set of policy
and legal questions that have to be understood if the scheme is going
to provide any security.


Users expect privacy and security.  We've all seen the legislation around
the globe for stronger security and privacy options.  SSL won't fix
everything, I know, but it is a solid step, and its the responsible step for
the protocol.  I don't understand how we can argue that HTTP/2.0 could be a
protocol for the next 20 years if it is sniffable over the wire.

Go talk to non-techie users about whether HTTP is secure.  They assume it
is.  Ask them if they would prefer a secure protocol or an insecure one.
Ask them if they think protocols should be eavesdroppable so that other
people in the cafe can see what they're doing, steal their passwords, and
more?  I have yet to find any of these users that want this flimsy level of
security.

So- the problem we're solving here is to make users safer and raise the bar
on web security globally.

Mike





On Tue, Jul 17, 2012 at 10:30 PM, Mike Belshe <mike@belshe.com<mailto:mike@belshe.com>> wrote:
Mandatory SSL is +1 and very forward thinking.

On Tue, Jul 17, 2012 at 6:22 PM, Phillip Hallam-Baker <hallam@gmail.com<mailto:hallam@gmail.com>>
wrote:

-1

I don't want to have a mandatory requirement unless it is going to
change behavior.


I don't think we can change behavior with protocols.  All we can do is
offer
new features.  If the features are compelling, people will upgrade.  If
the
features are not compelling, they won't.

People used to tell me SPDY would never get people to "upgrade".  Even
after
touching a half a billion users, people still tell me that.  I think the
evidence of adoption speaks for itself.



We already have ubiquitous deployment of TLS in browsers. The code is
freely available, everyone knows the benefit.

The only HTTP servers or clients I am aware of that don't have TLS
support are either toolsets that the provider expects to be used with
OpenSSL or the like and embedded systems.


I'll ask the google crawler guys to weigh in on this.  They have pretty
good
stats.  I believe your assertion is provably false.



Incidentally, suport for IPSEC is mandatory in IPv6 but that does not
seem to do any good either. It just means that IPv6 is harder to
deploy as implementations are required to support a security layer
almost nobody uses as TLS has proved better.


Making TLS a mandatory requirement seems like a feelgood approach to
security to me. Instead of doing something useful, we pass a
resolution telling people to do what they plan to do anyway.


You imply there is something else that would be useful - what would it
be?
(don't feel obliged to answer :-)

To me mandating security is a great first step.  Nobody should think
this
'fixes' security. But if we believe the net ever needs to be secure, we
need
to start taking steps toward that.

Mandating SSL is a simple step we can take which solves most of the
eavesdropping problem right now.  But more importantly, it poises us to
address the next set of security issues, including CA/verification
problems,
distribution of video over ssl, handshake latency, etc.  Until we start
trying to be secure, of course we'll never be secure.

Mike




On Tue, Jul 17, 2012 at 8:51 PM, Paul Hoffman <paul.hoffman@gmail.com<mailto:paul.hoffman@gmail.com>>
wrote:
+1 to what seems to be a lot of developers: make TLS mandatory.

so, even when used in an internal application protocol, it's going
to
be end to end
encrypted to make it super hard to debug?

In an internal application protocol, why would it be "super hard to
debug"? The client can do an HTTP dump before TLS, the server can do
an HTTP dump after TLS; either of the sides could debug the TLS.

http is about more than users using
web browsers.

Completely true, and not relevant. Insecure HTTP for non-browser
applications still has the same bad properties, no?




--
Website: http://hallambaker.com/





--
Website: http://hallambaker.com/





--
Website: http://hallambaker.com/
Received on Wednesday, 18 July 2012 05:28:10 GMT

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