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How a Google Headhunter’s E-Mail Unraveled a Massive Net Security Hole
"Harris wasn’t interested in the job at Google, but he decided to crack the key and send an e-mail to Google founders Brin and Page, as each other, just to show them that he was onto their game."
- jfc 14y agoI hope this guy's inbox is full of job offers. That's a heck of a find.
- clicks 14y agohttp://www.linkedin.com/in/drzacharyharris http://www.linkedin.com/in/drzacharyharris Wow, the guy's a monster. Fluent in classical (and Levantine) Arabic, Chinese, Greek; Top Putnam score (twice), teacher, Christian missionary. Sounds like he's got drive.
- jnhnum1 14y agoNit-picky corrections: 1. Top Putnam score in Colorado. There's a pretty big difference between that, and say, top Putnam score in Massachusetts (which is more likely the same as top overall due to many Putnam Fellows coming from Harvard or MIT). 2. Elementary proficiency in Classical and Leventine Arabic, Mandarin Chinese, and Koine Greek
- Evbn 14y agoWow, #1 sets off my tryhard alarm. Especially at the college level where a huge portion of high Putnam scorers migrate to locations like Cambridge and California. top 50 or even 200 overall or whatever is far more impressive than #1 in a state that has no reputation for high scores.
- guylhem 14y agoMaybe he loves the place he lives in, he's quite happy doing the kind of work he does, and thus want to stay instead of moving to another place. The rat race is not for everyone.
- jacquesm 14y agoCan you beat any of it?
- jnhnum1 14y agoSure, I may have actually done better on the Putnam than he has. I've gotten top 100 and top 200 before... but that really wasn't the point I was trying to make. I was just making the correction because the original claim is, at least to me, much more impressive than what is actually stated on his resume.
- deleted 14y ago[deleted]
- enjo 14y agoIt's not like there aren't plenty of smart people in Colorado. http://www.colorado.edu/news/series/cu-boulder-nobel-laureates http://www.colorado.edu/news/series/cu-boulder-nobel-laureat... (add David Wineland to that list).
- pgsandstrom 14y agoDangerous move, other companies have would set the police on him for that stunt.
- deleted 14y ago[deleted]
- alexchamberlain 14y agoThere are a lot of stories of people getting jobs by disclosing security holes like this.
- jere 14y ago>But the government of Iran probably could, or a large group with sufficient computing resources could pull it off. Yes, I can see it now: Iran endures crushing sanctions in order to pursue spam email program.
- theycallmemorty 14y agoSPAM is not the only attack that can be carried out with this kind of exploit.
- jlgreco 14y agoThe rule of thumb that I have heard, and seen played out, is that there are basically 3 tiers of who can factor what. governments or government sized companies (upper millions, or billions sized budgets), modestly sized companies / research projects (millions), or hobbyists. Each can handle about 256 bits more than the next, and the time for one to reach the capabilities of the other is somewhere between 5 to 10 years. Hobbyists have been factoring 512bit keys on a whim for a few years now, so....
- Cogito 14y agoFull article: http://www.wired.com/threatlevel/2012/10/dkim-vulnerability-widespread/all/ http://www.wired.com/threatlevel/2012/10/dkim-vulnerability-...
- DanBC 14y ago> Harris thought there was no way Google would be so careless, so he concluded it must be a sly recruiting test to see if job applicants would spot the vulnerability. Perhaps the recruiter was in on the game; or perhaps it was set up by Google’s tech team behind the scenes, with recruiters as unwitting accomplices. Ha! That's optimistic.
- Xion 14y agoOr paranoid. Or naive. Or narcissistic. It might be somewhat feasible if they wanted him to be security engineer, not a devop. Still, he expected they have set up what essentially is an elaborate prank just to send a cold-call email to just one of probably numerous potential candidates. How likely this is? What would be the risk-to-reward ratio for doing that, considering that many of unsolicited recruiting mails are not even read? Isn't it more feasible for it to be a genuine mistake on their part? Google's not infallible, omnipotent being after all.
- spindritf 14y agoThey could send a large number of recruitment e-mails crafted like that at negligible cost, not specifically for that one guy, and see who catches it. A little far-fetched but within the realm of possibility with a company known for geeky stuff.
- rachelbythebay 14y agoBack when I believed the hype, I made the same mistake with materials from Google's recruiters. They gave me driving instructions from SJC which left me in the wrong part of the valley on a Friday night during rush hour (this was before smartphone navigation). I figured it was some kind of test. It wasn't. I called it my "cleverness attribution error" and wrote about it this summer: http://rachelbythebay.com/w/2012/06/19/attrib/ http://rachelbythebay.com/w/2012/06/19/attrib/ I've run into it in a few other places, too.
- seacond 14y ago"a _few_ other places" I think you are being very diplomatic. :) But seriously, this cleverness attribution error might be a big problem with large players like Google. Forum posters, blogs and the digital versions of mainstream media all seem convinced Google is somehow special. That they know what they are doing, at every turn. Assuming some silly mistakes is a "test". It's a potentially harmful meme: people assuming ideas like "genius" or "utmost comptetence" without requiring any proof. Blind faith followers take note, because here we have _proof_ that Google makes mistakes too. Silly ones at that.
- tptacek 14y agoDKIM is an anti-spam mechanism. It does not authenticate the sender of an email message; to do that, use something like PGP. This is an interesting story, but it's not a story about a "massive net security hole". Mail on the Internet has always been spoofable.
- Erwin 14y agoGmail (possibly Hotmail) put a little lock icon next to DKIM authenticated email from some senders, such as eBay & PayPal and outright reject unauthenticated emails from such domains. They've flaunted this feature in the past So if an authenticated PayPal email pops up in your Gmail inbox saying you must do this and that to unlock your account, you may be more likely to do so due to the legitimacy of DKIM.
- tptacek 14y agoThe reality is that people will act on "Paypal" mail that comes from "Payapal.ng". Let's not pretend that DKIM has much to do with that decision. I agree, though, that the little lock in the Gmail UI is misleading.
- borski 14y agoThat UI affordance is actually incredibly frustrating for us, because we get that question a lot. Tons of people get confused by it.
- deleted 14y ago[deleted]
- downandout 14y agoJust register serverX-paypal.com (where x is a number) ftw. People in general are stupid. When asked what browser they use, the overwhelming majority respond by saying "Google". That says all that needs to be said about the general public.
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- seanica 14y ago“A 384-bit key I can factor on my laptop in 24 hours,” he says. “The 512-bit keys I can factor in about 72 hours using Amazon Web Services for $75. And I did do a number of those. Then there are the 768-bit keys. Those are not factorable by a normal person like me with my resources alone. But the government of Iran probably could, or a large group with sufficient computing resources could pull it off.” "But the government of Iran probably could"...At this point I stopped reading, as this article became propaganda. Did you know this month is National Cyber Security Awareness Month, as advertized by the DHS? http://www.dhs.gov/national-cyber-security-awareness-month http://www.dhs.gov/national-cyber-security-awareness-month
- philh 14y ago> At this point I stopped reading, as this article became propaganda. Even if that was true (it's not), how could you know it without reading further?
- seanica 14y agoWhat's not true? (what's 'it' that you talk about)
- philh 14y agoThe article did not become propaganda.
- seanica 14y agoThe article up to that point was great. However, that sentence "But the government of Iran probably could" made the preceding paragraphs appear to be a vehicle to deliver a meme (like a shaggy-dog story). The rest of the article could have been great, I just stopped reading. The journalist could have made a neutral statement about what entities have the resources to crack a 768-bit key. But they or their editor chose not to. Instead, everyone that reads the article will go away with the meme "Iran, if they wanted to, could crack 768-bit keys". Which is, by common definition, propaganda. It might be unintentional, i.e. the journalist is riding a wave of popular opinion, which they should not do; or it might be an attempt to load the article with link bait.
- jgrahamc 14y agoSeriously old news... I attacked Facebook's 512 bit DKIM key back in 2010: http://blog.jgc.org/2010/06/facebooks-dkim-rsa-key-should-be.html http://blog.jgc.org/2010/06/facebooks-dkim-rsa-key-should-be...
- dredge 14y agoI was just writing that! It was on HN too, of course: http://news.ycombinator.com/item?id=1442385 http://news.ycombinator.com/item?id=1442385 I was surprised then that anyone would be using a 512-bit RSA key in the wild, let alone now.
- Evbn 14y agoSo this is one key, used for all a domain's email for a long time, right? How lazy must you be to use an under specced key?
- jrabone 14y agoPlenty of crappy DNS web admin "tools" limit the maximum length of a TXT record. Sometimes it's harder than just typing "1024" instead of "512"...
- tptacek 14y agoI'm curious to hear what you think about DKIM in general.
- jgrahamc 14y agoAt one time DKIM and SPF were good indicators that an email was spam because spammers adopted it so that their mail looked more legit. I never look at DKIM or SPF. If I really care about who a message comes from I use PGP. It's a handy input for learning spam filters that use it as one piece of information, but it has about a 10% failure rate (legit mail where the signature fails to verify because of message manipulation in transit). It's most useful if the domain it's matching against is also trusted in some way. For example, a good signature against google.com is likely to mean the mail is good; a good signature against frohfuwehfwo.biz is not very helpful unless we know that that domain always sends spam. Also, the most important piece of mail I ever received (from the Prime Minister's office) came without SPF or DKIM and I authenticated it by calling the office. In general, external authentication like that tends to reassure me.
- Sami_Lehtinen 14y agoWell, afaik key length isn't the problem. Weak algo is. I assume they use RSA, they should use ECC. 512 bits is more than enough. https://www.nsa.gov/business/programs/elliptic_curve.shtml https://www.nsa.gov/business/programs/elliptic_curve.shtml
- tptacek 14y agoYou can't use ECC for DKIM.
- mikeash 14y agoThat doesn't make much sense. There are key lengths for which RSA is strong, and key lengths for which ECC is weak. ECC keys may be stronger at shorter lengths, but that hardly means that key length isn't the problem. After all, using a longer key would fix this problem.
- dfox 14y agoUsing ECC would solve this particular problem, because in both DKIM and DNSSEC usage of key lengths of 512 to 768 bits and not more are motivated by what can fit into one UDP DNS reply packet. Also for RSA signature size is equal to key length, and not some small multiple of security parameter and you don't want to expand messages by including large signature that might well be larger than actual payload.
- mikeash 14y agoRight. Either expanding the key length or using ECC would fix it. So saying the problem isn't one of those, but is only the other, doesn't make much sense to me. ECC may even be a better solution, as you say, but that doesn't mean that the problem isn't also one of an insufficiently long key.
- Evbn 14y agoProps to Wired for disclosing that their silly phony photo setups are phony. I found that comforting. Props to Google for fixing the problem instantly. Weird that he thought the email was phony based on content. Who wouldn't want a computer savvy math genius on their team? Google has lots.
- meshko 14y agoGoogle very rarely hires pure mathematicians AFAIK.
- meshko 14y agoI find it cute how clueless mathematicians and physicists are about how clueless we (programmers) are. Weak crypto? Assume it is a puzzle!
- SparrowOS 14y agoNo abortion for rape victims. What about alien abductions? What about virgin births? God says... stand before thee, until thou have destroyed them. 7:25 The graven images of their gods shall ye burn with fire: thou shalt not desire the silver or gold that is on them, nor take it unto thee, lest thou be snared therin: for it is an abomination to the LORD thy God. 7:26 Neither shalt thou bring an abomination into thine house, lest thou be a cursed thing like it: but thou shalt utterly detest it, and thou shalt utterly abhor it; for it is a cursed thing. 8:1 All the commandments which I command thee this day shall ye observe to do, that ye may live, and multiply, and go in and possess the land which the LORD sware unto your fathers. 8:2 And thou shalt remember all the way which the LORD thy God led thee these forty years in the wilderness, to humble thee, and to prove thee, to know what was in thine heart, whether thou wouldest keep his commandments, or no. ---- God says... self-will incredibly Life Roman securely transmitted smoke flights profound upper promiseth brethren refrain regeneratedst hide unresolved seed enlarging dearer goest falsely hippy approveth eateth cursing Tomorrow I_didn't_see_that variety GET teaching perhaps Aristotle trouble founded justice quickened tax-deductible regardless invited well-being delivered Each valley certain cogitated favours Hortensius whirlpools feeds like requital bewail hedged prevails ---- What's Yer top ten hated topics? God says... 24:20 The womb shall forget him; the worm shall feed sweetly on him; he shall be no more remembered; and wickedness shall be broken as a tree. 24:21 He evil entreateth the barren that beareth not: and doeth not good to the widow. 24:22 He draweth also the mighty with his power: he riseth up, and no man is sure of life. 24:23 Though it be given him to be in safety, whereon he resteth; yet his eyes are upon their ways. 24:24 They are exalted for a little while, but are gone and brought low; they are taken out of the way as all other, and cut off as the tops of the ears of corn. 24:25 And if it be not so now, who will make me a liar, and make my speech nothing worth? 25:1 Then answered Bildad the Shuhite, and said, 25:2 Dominion and fear are with him, he maketh peace in his high places. ---- God once said He was not happy with women who don't have kids. ---- What are You going to be for Halloween, God? God says... ye were blind, ye should have no sin: but now ye say, We see; therefore your sin remaineth. 10:1 Verily, verily, I say unto you, He that entereth not by the door into the sheepfold, but climbeth up some other way, the same is a thief and a robber. 10:2 But he that entereth in by the door is the shepherd of the sheep. 10:3 To him the porter openeth; and the sheep hear his voice: and he calleth his own sheep by name, and leadeth them out. 10:4 And when he putteth forth his own sheep, he goeth before them, and the sheep follow him: for they know his voice. 10:5 And a stranger will they not follow, but will flee from him: for they know not the voice of strangers.
- tolos 14y agoWhat a happy ending, no threats of jail or lawsuits.
- scotty79 14y agoIt's still bit of a let down that they didn't contacted him in any way. They could at least track him and since he is a well meaning guy they could send him something funny.
- suyash 14y agoWhat is the Direct Link to this guy's website?
- eranation 14y agoOk, this got me scared, checked with Sendgrid support,of course they use 1024, back to breathing again.
- seacond 14y agoSeems to be some conflation in this thread. Are DKIM and authentication (PGP) really comparable in practice? Here's my take: DKIM is an attempt by _third parties_ (i.e. "email providers", not the author or the recipient of the message) to control who can send email (but guess what? anyone can send email, go figure). On the other hand, authentication (PGP) is an attempt to allow senders to sign messages and receivers to verify signatures (no third parties needed). Bob printed his PGP public key on a card and gave it to Alice when they had lunch. He then signed an email message the following week using PGP and sent it to Alice. But Bob's "email provider" decided to block Bob's message because Bob didn't pay money to someone for the use of a "domain name" and Bob's "email provider" thought his email was "spam" because he hadn't been "authorized" (by paying money for use of a domain name) to send email.
- snowwrestler 14y agoDKIM is not the only tool for catching spoofed emails; to my knowledge SPF is more widely used because it is much easier to set up. I'd be shocked if the little Larry/Sergei joke email made it to their inbox since it would fail the SPF lookup.
- samuellb 14y agoYes lots of sites have SPF, but what I've seen most sites set it to soft-fail mode. I think this is because SPF is still sometimes broken in practice. For example, it can fail when there are misconfigured e-mail forwarding (e.g. mail aliases) at _other_ peoples servers[1]. Or with web forms that set the envelope sender to the "From" field in web page... http://en.wikipedia.org/wiki/Email_forwarding#Forwarding_versus_remailing http://en.wikipedia.org/wiki/Email_forwarding#Forwarding_ver...
- Kliment 14y agoI got one of those emails too once. I still can't figure out why. I did post to LKML a couple times in the past, but I haven't done anything kernel in over a decade. And a random Google recruiter emails me to congratulate me on my experience and offer me an unspecified position as a SRE. Not only do I have zero experience or interest in sysadmin and large server type stuff, they don't even have any facilities within 400km of me. What the fuck, Google?
- HerraBRE 14y agoIn my experience (ex-Googler here), recruiters tend to be contractors who work off a script and get bonuses proportionate to how many people end up in the hiring pipeline. There are checks and balances to prevent outright spam, but the motivations are aligned in such a way that a pretty wide net is cast. Also, until you have interviewed, all positions are "unspecified". Many positions need to be filled and they don't pick one for you until they know what you can do. Geography is not really considered to be an issue. Once SRE finds someone they really want they will help with relocation.
- cyber 14y agoAlso an ex-Googler here, they cast the net far and wide trying to pick up SRE. When I was there they were offering significant bounties for submitting recommendations that only had to make it pass the resume screen. Want a brand new shiny PS3? Less than 10* that made it past the resume screen, and it was yours. I has additionally heard rumors that recruiters were so silo'ed that they would actually just throw away a resume rather than route it. Reason being that they were in a competition with all recruiters, and worst performers (based strictly on a numbers game) didn't get their contracts renewed. *May have been as low as less than 5, its been a few years, and I never really took to memorize what was posted on the wall while I was at the urinal.
- wia 14y agoSloppy work by affected companies since RFC was unambiguous. But why didn't RFC keep it consistent by requiring verifiers to only work with the same minimum key length? RFC 4871 (sorry for formatting but ipad issue) " signers MUST use RSA keys of at least 1024 bits for long-lived keys. Verifiers MUST be able to validate signatures with keys ranging from 512 bits to 2048 bits, and they MAY be able to validate signatures with larger keys. Verifier policies may use the length of the signing key as one metric for determining whether a signature is acceptable. Factors that should influence the key size choice include the following: o The practical constraint that large (e.g., 4096 bit) keys may not fit within a 512-byte DNS UDP response packet o The security constraint that keys smaller than 1024 bits are subjec to offline attacks..."