On 2 Jan 2009, at 12:33, Joe Greco wrote:
We cannot continue to justify security failure on the basis that a significant percentage of the clients don't support it, or are broken in their support. That's an argument for fixing the clients.
At a more basic level, though, isn't failure guaranteed for these kind of clients (web browsers) so long as users are conditioned to click OK/ Continue for every SSL certificate failure that is reported to them?
Yes. This is a major problem.
If I was attempting a large-scale man-in-the-middle attack, perhaps I'd be happier to do no work and intercept 5% of sessions (those who click OK on a certificate that is clearly bogus) than I would to do an enormous amount of work and intercept 100% (those who would see no warnings). And surely 5% is a massive under-estimate.
Yet I do not particularly wish to ignore the problem, just because we do not have a completely comprehensive solution to the problem that solves every case and prevents every mistake. The Firefox changes to really draw attention to certificate issues is, regardless of what people have said about "usability" and "practicality," an important step. However, there's something else being highlighted here. SSL certificates have a major failing in that it is really spectacularly annoying and difficult for some people to acquire them, and/or the value in paying more than a trivial sum (or any sum) is hard to justify, etc. For example, I have absolutely no desire to pay even a modest $15/year per device to get all my various networking devices to have legitimate SSL certificates; instead, we run our own local CA and import our root CA cert into browsers. It's cheaper, *more* secure, etc. Nobody but us will be logging into our devices, and our browsers have the local root CA added. Now, many sites just don't see the need, and self-signed certs are the result. This would seem to point out some critical shortcomings in the current SSL system; these shortcomings are not necessarily technological, but rather social/psychological. We need the ability for Tom, Dick, or Harry to be able to crank out a SSL cert with a minimum of fuss or cost; having to learn the complexities of SSL is itself a "fuss" which has significantly and negatively impacted Internet security. Somehow, we managed to figure out how to do this with PGP and keysigning, but it all fell apart (I can hear the "it doesn't scale" already) with SSL. ... JG -- Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net "We call it the 'one bite at the apple' rule. Give me one chance [and] then I won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN) With 24 million small businesses in the US alone, that's way too many apples.