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Re: Mandatory TLS == OpenSSL everywhere? !?!

From: Adrien de Croy <adrien@qbik.com>
Date: Thu, 14 Nov 2013 23:02:51 +0000
To: "Mike Belshe" <mike@belshe.com>, "Tao Effect" <contact@taoeffect.com>
Cc: "HTTP Working Group" <ietf-http-wg@w3.org>
Message-Id: <em5097f53d-2b0b-48bb-854c-c2588fd2dea7@bodybag>


------ Original Message ------
From: "Mike Belshe" <mike@belshe.com>
>One of the things that the IETF does with all new standards is to build 
>multiple, working implementations.  This was done as part of the TLS 
>development as well as HTTP.
So the IETF has built a new from-scratch TLS implementation that is 
freely usable?  What's it called? How can we predict how secure that 
will be?

>
>
>Rob T could comment further, but I don't believe the windows TLS stack 
>has much (any?) OpenSSL in it.
Sure, it's hard to tell whether Schannel is easier to use than OpenSSL 
or not though.  And a quick view through windows update history shows 
enough security patches related to schannel to bolster a complexity 
argument.

Glad to learn about NSS though.  We will look further into that.

Of the other implementations mentioned, only relatively few have a 
license that many commercial software companies could or would use.  
Unless people have previous negative experience with a free license 
implementation, they would probably choose it over a commercial license. 
  Lack of patronage of an implementation would lead to security concerns 
as well.
>
>It shouldn't be a surprise that there are fewer TLS implementations 
>than HTTP implementations - complexity aside, HTTP is much larger than 
>TLS today.  But, if HTTP uses it more, we should see that go up over 
>time.
I don't really understand what you mean here.  You mean HTTP is more 
used than TLS?  I'd agree with that.  You're saying you expect to see 
more implementations?  More heterogeneity is a good thing IMO.

At the moment though I do think OpenSSL would have enormous coverage, 
and changing out TLS library is unlikely to be a simple matter for 
existing OpenSSL users.  So there will be a lot of inertia, and a lot of 
continued use of OpenSSL, if only on the server-side.

>
>I disagree that we glossed over these issues.
I didn't see them discussed on list, but I may have missed it.

Adrien

>
>Mike
>
>
>
>On Thu, Nov 14, 2013 at 1:58 PM, Tao Effect <contact@taoeffect.com> 
>wrote:
>>Yeah... thanks for bringing that up.
>>
>>The sad thing is that OpenSSL is already basically everywhere (from 
>>what I can tell).
>>
>>I think it might be in all the major browsers, is that correct?
>>
>>And it's in Apache (via mod_ssl), and most of the other servers that 
>>exist, is that correct too?
>>
>>I'd like to see a pie chart of OpenSSL usage in the top used web 
>>servers and top used browsers. Anyone know of one?
>>
>>Then there's the "OpenSSL is written by monkeys" problem:
>>
>>http://www.peereboom.us/assl/assl/html/openssl.html
>>
>>The situation appears to be that we're using a crypto library, written 
>>(allegedly) by monkeys, in C, and only a handful of people and/or 
>>monkeys have actually looked at the code.
>>
>>Additionally, C, and just about all its variants, makes it remarkably 
>>easy to write insecure code (by accident), and easy to write malicious 
>>code that can sit right in the open and not be noticed those working 
>>with the code:
>>
>>https://en.wikipedia.org/wiki/Underhanded_C_Contest
>>
>>It's not a new problem though... it's been with us "since like 
>>forever." You've probably been pwn'd and haven't realized it. :-p
>>
>>- Greg
>>
>>--
>>Please do not email me anything that you are not comfortable also 
>>sharing with the NSA.
>>
>>On Nov 14, 2013, at 4:35 PM, Adrien de Croy <adrien@qbik.com> wrote:
>>
>>>Hi all
>>>
>>>one of the things that has been troubling me about the mandatory TLS 
>>>discussion, that I don't recall having seen discussed here is the 
>>>issue of the implicit assumption that it's free or low-cost to 
>>>include TLS into a product due to the availability of open source 
>>>implementations.
>>>
>>>I think that assumption needs looking into a bit further.
>>>
>>>I'm going to go out on a limb here, and speculate, that if TLS were 
>>>to become mandatory in HTTP/2 that the vast majority of implementers 
>>>would choose OpenSSL for the TLS implementation.
>>>
>>>That immediately raises a number of issues.
>>>
>>>1. Homogeneity and therefore susceptibility to exploits having 
>>>effectively global reach.
>>>2. Maintainability of the source
>>>
>>>A related issue is the complexity argument which I also haven't seen 
>>>put here.
>>>
>>>TLS is complex.  The crypto is complex.  Implementations of TLS with 
>>>the cipher suites contain at least many hundreds of thousands of 
>>>lines of code.  Most of it fairly impenetrable from what I've seen 
>>>sorry to say.
>>>
>>>Compared with an implementation of an HTTP stack, a TLS 
>>>implementation completely dwarfs it for complexity and amount of 
>>>code.   Since these things are not maintained by infallible aliens 
>>>but us mere mortals, there will be bugs.
>>>
>>>OpenSSL in my experience has had many troubles with vulnerabilities 
>>>and stability.  And it's an enormous undertaking for someone to 
>>>fathom the code to attempt any maintenance on it at all.
>>>
>>>Does this mean, that if we made TLS mandatory, that effectively we 
>>>would be placing the security of the web in the hands of the OpenSSL 
>>>contributors.  I think it effectively does.
>>>
>>>This is an EXTREMELY disturbing thought.   The security of the 
>>>systems associated with maintenance and deployment of OpenSSL are not 
>>>at a sufficient level to warrant this level of global reliance.  My 
>>>own experience with OpenSSL has not been without serious problems, 
>>>and in fact we've looked to ditch it many times and may still do.
>>>
>>>I don't think it is realistic to expect that http agent (server or 
>>>client) developers will put much effort at all into maintenance of 
>>>the TLS library.  So maintenance will remain the domain of the few 
>>>contributors.
>>>
>>>Too many eggs in too few baskets.
>>>
>>>Adrien
>>
>
Received on Thursday, 14 November 2013 23:02:48 UTC

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