it relies on being able to statistically discern a few microsecond-level timing differences
which can be done on a 100base-T network. so if your client and server are on the same (fast) internal network, and nothing is adding any excessive jitter, it's feasible.
so internet? no. corporate network? maybe.
especially when you consider that a lot of high-end server gear will be sat on 1Gbase-T or even fibre channel.
@Polynomial how does chatting work on reddit? I can't see how reddit works at all, to be honest, as there appears to be no way to track items, search, or follow conversations. I tend to browse to it and follow some links to interesting things, but I know I'll never find them again unless I bookmark them...
@Tinned_Tuna Unlikely. If δt (small time delta) between padding failure and padding success is in the μs range, any jitter from the latent connection, i.e. Δt, would make it very difficult to discern.
think of it like a whisper at a concert. if you're stood next to the person and the band isn't playing right now, you can just about make it out. if you're far away from them or the band is playing, you've got no chance.
the small sound you're trying to identify is drowned out by the loud sounds in the room.
in fact, for any case where Δt > δt you're going to struggle, unless Δt is highly predictable (e.g. fixed)
essentially you want a case where ΔΔt < δt, i.e. the unpredictable change of latency in the network is lower than the measurable time delay caused by the padding failure.
@Tinned_Tuna For md5, it's not so much an "attack" but a collision, so you have two values a,b such that md5(a)=md5(b). The interesting part is finding those collisions. From an exploitation point of view, using that fact if you have a collision in say a hash of say a certificate using md5, you might be able to alter data under the signature. If you can find the right collision you can do so in a meaningful way, i.e. one that is actually useful for doing bad things.
md5's weakness is that it is no longer all that hard to find collisions.
All hash functions have this property, since you're always taking an infinite space and mapping it onto a finite space - see pigeonhole principle. However, hash functions have collision-resistance which basically means finding two such pairs should be hard.
@Polynomial There is more to it, actually. People talk about SSL but miss the big picture. If you can measure µs delays from the outside, then anything you do with some private data is susceptible to attacks. Cryptographers concentrate on the crypto layer and keys but the rest of the code which lies beyond the SSL is as attackable as the SSL layer itself.
SSL is already behind all the code for the ethernet driver and the TCP/IP stack, and yet this does not mask out the µs delays in the SSL layer. Simply think a bit farther up the stack: µs delays in the server code (e.g. the ones which access the database) will be equally deadly, perhaps even more so.
@Tinned_Tuna The existence of collisions is a mathematical necessity. Being able to actually show one, and, even more, being able to compute a new one every 14 seconds, is an attack.
last year's was utterly mental. open bar all night.
drank all the hotel's booze, then they took all the downstairs bar's booze, and we drank all that too. then they went across the road to a cafe/bar place and bought all their booze, and we drank all the beer and most of their rum. then we went to the pub.
@Tinned_Tuna It resulted in me and two other lads wandering round who-knows-where on the outskirts of London looking for a pizza place and trying to find our way home.
I always imagine that the infosec crowd drinks so much because we have to deal with the unrelenting retardedness of bad development and bad security practices.
either that or we drink to celebrate how fucking easy our job is :P
MS03 vulns unpatched on the DC? Right, well that's that done with then. Let's crack open a beer!
@AviD Hey I resemble that comment... :) though it all boils down to the fact that every developer assumes that every other developer is good and so that their code doesn't need to check its input variables. If you ever have access to the source code, the first thing anyone should do is a search for "assume" :)
haha, that was awesome. postman came to the door and I had Sekai de 2ban me ni Shiawase by USK playing (super happy/bouncy 8-bit) in the background, and he just gave me the weirdest look.
When calling from your cell phone, do you tell your operator about your number (to be shown on CallerID) or does the operator send that on their own to the call receiver?
Biggest problem in trust management is that it involves people who don't act like machines.
Public-Key Infrastructures can be seen as a big exercise in trust management. The two main deployed solutions, X.509 and OpenPGP, implement two strategies which can be described as "let's add all the need...
@Iszi I tried to improve it, and if there had been no answers I probably would have closed, but having a binding vote and there being a good answer already makes mods back off a bit :-)
@ScottPack You need an asterisk on there: "but make sure you use SSL3 or later, and don't use CBC, or compression, or MD5... or asymmetric keys below 2048 bits."
@CodesInChaos I'm not sure what's more impressive: The stupidity it took to even think that was a good idea, the balls (pun intended) to actually try, or the fact they managed to pull it off!
man, this upcoming gig is gonna be mental. DevilDriver and Cannibal Corpse as dual headliners, with Winds of Plague and Black Dahlia Murder supporting, plus a "special guest".
@CodesInChaos Nah, DevilDriver are more groove metal than angry sadism stuff. Cannibal Corpse could certainly be described as sadists. WoP / BDM are more metalcore than anything else, so borderline-emo lyrics with insane drums and heavily downtuned guitars / lots of breakdowns.
doors open at 5.30pm and it runs until 11pm, so it sounds like both headliners are doing a full set.
@TerryChia In 2003, for an business project, I wrote the spec (and implementation) for a kind-of-SSL which had the benefit of running over HTTP, rather than the reverse.
@Polynomial I'll have to have a look at their current playlists, but aside from Eilin's occasional dance stuff (she seems to like the current almost-parkour-like street dance stuff) they solely get their music from my rock and metal playlist
It so happens than when Gnome's web browser (called "Epiphany" or sometimes just "Web") is open on Sec.SE, it keeps the CPU running at 100% all the time.
How they manage to make that kind of bug is an open question.
@RoryAlsop I don't know. The site still works... my best guess is that there is some timer-based Javascript and the timer code is wrong, triggering the code immediately instead of (e.g.) once per minute.
I use Epiphany for Bear#2 posts during breakfast. This is on an old Mac (PowerPC) with Linux, making the choice of browsers kinda limited.
Apple is designed like a master architect / artiste - "*I* know what is best for you, you will take whatever I give you - *and like it*. Android is like a DIY shop - just gives you all the pieces, and you could put it together however you want. Windows Phone is like a professional architect, but not at the artiste level - designed around what *you* want, so that your kitchen puts everything right in reach where you expect it to be.
@RoryMcCune true. I too like the hugephone.
I almost bought the Titan last time around - I think it's 4.9 inch, when the next largest phone anywhere was 4.1.
@AviD Dunno if you'd call me a "diehard" tweaker, but I do like to be able to make things work the way I want them to. One particular thing that frustrates me about WP8 is that you can't arrange apps into folders.
@AviD Eventually I expect my home screen to look like my Desktop occasionally does - overloaded and cluttered.
Nice thing with the Desktop is, you can put stuff into folders. Or you can remove stuff entirely and get to them via the start menu - which is arranged in folders.
on desktop, you can zoom out to see just the group headers -ish, and you can place an app in a specific group, etc.
@Iszi well, there are groupings on WP too, just alphabetically.... ;-)
I'll be honest - it hasnt been an issue for me.
perhaps I dont use enough apps to hit that point, but most of what I use is either right there on homescreen (and I prefer a scroll + one click, than foldering through) or I just jump in the all apps list straight to it (either scroll, by letter, or by searching).
one of the reasons I'm planning on Android for my next phone is the more customizable piece definitely. Also has some nascent security tools which could be useful..
@RoryMcCune think it appeals more to the security tool devs - less hassle with getting apps approved etc. Yes, that has its downsides, but also aids development
