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McGill will double your password if you don’t do it first
- vitamen 12y agoIs this effective at stopping attacks (given that it is public knowledge), or is it mostly a measure to annoy users into updating their passwords to something less cumbersome?
- Cerium 12y agoI think this is to annoy the users.
- cannedbass 12y agoSeemed like a good idea until it dawned on me that this means the passwords are stored as plaintext.
- hga 12y agoThere are several ways this can be done without that. Easiest is if they store the date of the last password change or otherwise know you haven't changed it. If it's old enough, double the plaintext before handing it to the hashing function.
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- penguat 12y agocheck that it's a string of the right form (e.g. it repeats something exactly twice) and then derive the original password from that, before feeding it to your hashing function.
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- vertex-four 12y agoIf the database record says the user hasn't changed their password, split the given password in half, check that both halves are equal to each other, and check that one half matches the hash of the password.
- sehrope 12y ago>> Seemed like a good idea until it dawned on me that this means the passwords are stored as plaintext. >There are several ways this can be done without that. >Easiest is if they store the date of the last password change or otherwise know you haven't changed it. If it's old enough, double the plaintext before handing it to the hashing function. Not quite. What you'd need to do is halve the user's entered password if it's older than the cutoff date. If the user enters "foobarfoobar" then you'd halve it to "foobar" before hashing and comparing it to what's stored. If you only have the old hashed password stored then you don't have the hash of the doubled password, nor can you can infer it. This whole approach is silly of course. They should just force everybody to reset their passwords.
- fabulist 12y agoThis is interesting. If I was a McGill employee, I'd be getting ready to try "foobarAAAAAA" and "AAAAAAfoobar"....
- MrSourz 12y agoThe reason to inconvenience rather than force is users in a rush will pick the worst passwords, even as paid employees where their password is the thing between the outside world and highly confidential stuff.
- ossreality 12y agoDid you think this through the rest of the way? That isn't enough to make it work... you can't just "duplicate" the hash sitting in the database. What???
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- comboy 12y agoThis must be some security joke. I would worry more about passwords not being hashed than the fact that some users didn't change them.
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- Widdershin 12y agoSomeone else pointed out, if you just had a flag on each user to indicate if the password is doubled, you could just check the hash of the first half of the provided password when the user logs in.
- rspeer 12y agoThe fact that they're able to "double your password" is a bad sign. Here's what this implies to me: * McGill had a database of everyone's password in plaintext at the time of Heartbleed * McGill is concerned about mitigating possible security compromises due to Heartbleed, including these plaintext passwords, which if they were compromised were compromised all at once * Despite this concern, McGill still has a database of everyone's password in plaintext. Oh, and a large proportion of them are still the possibly-compromised ones. * They're comfortable announcing this fact to the Web, for some reason. I really hope the first thing they do after doubling the password is put it into a password-hashing function and throw away the plaintext, and then make those users change them anyway, because the doubled passwords are still compromised. It sounds unlikely.
- Nogwater 12y agoI don't think that's necessarily true. Let's say they have all of the passwords stored as bcrypt hashes, and they also know the last time you changed your password. They could just update the application logic to check that your password is of the form <pw><pw> if your last change date is before X. Then to check the password, they just take the first half and check that against the hash.
- pwr22 12y agoOh God...
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- Dylan16807 12y agoDoubling doesn't provide a benefit, no matter how well they hash or don't hash.
- Aldo_MX 12y agoWhether it provides a benefit or not is unrelated to the fact that they don't need to know your plaintext password to use something like the regex I wrote to detect a string duplicated twice and extract the first match prior to hashing/checking against the DB.
- wfjackson 12y ago>The need to change passwords arose in April, when the Heartbleed vulnerability was revealed. Heartbleed makes systems vulnerable to data theft since attackers can use it to gain access to systems and then proceed to access and steal information without leaving a trace. >Even though our central IT systems are protected against Heartbleed, any accounts that have already been stolen still pose a security risk. Almost 20,000 members of the McGill community did change their McGill Password, but thousands more did not, and so additional actions have become necessary. So, ff the people who got the passwords read this post then all they need to do is double the passwords they got with HeartBleed to gain access? Perhaps they should quadruple the password? /s
- pcthrowaway 12y agoThe point isn't to make their system more secure, it's to annoy the users into changing their password.
- Cerium 12y agoNo, It does not mean that the password is stored as plaintext. Simply keep a flag for "UpdatedRecently?", if the flag is false, then not only should the first half of the input correctly match the hash, but the first half the input should match the second half.
- ChristianBundy 12y agoHow is that helpful for mitigating security issues though?
- Aldo_MX 12y agoUnless you are being specifically targeted (ie. the attacker knows that you have to repeat the password twice), you mitigate the easiest possible attack: user/password combination from a stolen database. Although I suppose this was done to force the users to change their password.
- tempestn 12y agoBecause it annoys the holdout users into changing their passwords.
- oxryly1 12y agoBack in my day (old man grumble) the system would force you to change your password on next login. Simple, effective. This approach is just a dumb prank.
- jarek 12y agoI dislike being forced to change password without notice, I need some time to come up with a secure, typeable one. Change on next login just results in me reusing an old password or adding a "2" to the current one.
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- Nogwater 12y agoAfter all of this effort, they're still limiting passwords to 18 characters? Why would they do that?
- jasonj79 12y agoI't because they are still storing passwords in cleartext... If they were hashing passwords (which is the correct way to do it) there would be no limit.
- simlevesque 12y agoThat is simply not true. I used to think the same but real world experience showed me that a lot of websites hash the passwords but they still set a limit to password length. You should read this : https://www.reddit.com/r/gfycat/comments/2m7ddd/how_does_gfycat_stores_the_passwords_of_its_users/ https://www.reddit.com/r/gfycat/comments/2m7ddd/how_does_gfy...
- zackify 12y agowhat the actual fuck
- simlevesque 12y agothis is hilarious
- zackify 12y agoThis is the same thing as blackboard, they store every password in plain text, nobody seems to care. I've been trying to bring attention to it.
- okonomiyaki3000 12y agoRIP Security.
- btilly 12y agoDoubling the password is cute, but it would be even more effective to change the password for you by appending constant text to it. The only challenge then becomes what constant text to add. I would suggest something like, ishouldlistentosecurity. :-)
- smlacy 12y agoAlthough highly suspect and troubling, this does not necessarily require that they have all users original passwords stored in plain text. If they had originally used a hashing function that obeyed the following: Hash(pw) + Hash(pw) := Hash(pw + pw) (NB: Where '+' above is really just a stand-in for any pair of combining functions, not necessarily arithmetic addition or string concatenation.) But, I agree with many others here that the likelihood of stored plain text passwords is very high.
- geofft 12y agoI think that the goal here is not to increase password strength, but to make typing your old, short password so annoying that you pick a different one (that complies with the current password strength rules). That is, this isn't aimed at attackers; it's aimed at users. If so, it's pretty clever.
- abritishguy 12y agoThen why not just force them to change the password on login?
- geofft 12y agoOne possible answer: Because tenured faculty can call up the helpdesk and get policies reversed, because they're tenured and the helpdesk isn't. Another possible answer: Many systems can't prompt for password changes, and will just continue to log you in (because, especially for remote-access systems, that's better than denying access and hoping you find another way to get logged in). Probably the lazier of the users also don't use very many of the computing facilities, and may just use a few legacy systems.
- gohrt 12y agowhat's tenure got to do with it? if tenured dinosaur faculty leave, that's a huge win for the budget.
- abritishguy 12y agoThey need to hire some competent IT people
- eksith 12y agoThe McGill Password length has also been increased from exactly eight characters to a variable length of eight to 18 characters. So they're not using bcrypt (usable length 72). Even PBKDF2 would have been acceptable, but my guess is that they were sold a "layer over" on their stack with this. I can already tell this is a hacky patch. Every year, about 1,200 to 1,500 McGill accounts are compromised in one way or another. Phishing + guessing. I know someone who gets about 2-3 emails a week asking to enter their login info into some site in Brazil or the Czech Republic. If every site properly salted and hashed passwords, reuse isn't even a problem. But as we know : - Most people choose crappy passwords. - Most sites use crappy hashing schemes (if they hash at all) When other sites are compromised, there's an easy list of ready passwords to try against other potential targets. McGill's problem isn't Heartbleed.
- danudey 12y agoThey may be artificially limiting the password length because other services which authenticate (e.g. VPNs, mail systems, older UNIX logins, administrative software, payroll, etc.) may have limits on password input fields.
- eksith 12y agoThis is why PBKDF2 would have made more sense then. They can centrally authenticate, derive a secondary token from the original pass while specifying the max limit for each of those services. Best of all, this means the mail, UNIX login etc... need not have the same login token.
- fabulist 12y ago> Phishing + guessing. I know someone who gets about 2-3 emails a week asking to enter their login info into some site in Brazil or the Czech Republic. I think it probably has something to do with this. https://www.mcgill.ca/it/channels/news/email-subject-internal-only-contains-malware-attachment-240148 https://www.mcgill.ca/it/channels/news/email-subject-interna...
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- omgitstom 12y agoEveryone is guessing if they are storing in plaintext or not. But that isn't the actual issue to learn from their mistake. They have publicly asserted what they are doing (which is great information for a hacker), and chose a bad way to attempt to force users to reset their passwords because of a compromise. I would feel better if it was an email directly to mcgill faculty / staff. If you are building out a user management system, you need a way to disable accounts and force a password reset. You never want to convey any information about the usernames, password, or state of the account _ever_. This is true for error messages during login, but can be applied to any messaging.
- mazlix 12y agothis is in no way more secure.... there's a bijection... any password that an attack wants to try they just double so instead of bruteforcing [aab, aac,aad] just [aabaab, aacaac, aadaad] the only reason this makes sense to do is to annoy users into changing their password
- hackuser 12y agoI'm not sure it improves security significantly, but the weak link is using passwords as security in an environment like a university. Getting users to confirm to good password practices is nearly impossible when they are mature, paid employees with money and valuable IP on the line, and at organizations with legal/regulatory security requirements. Imagine accomplishing that with thousands of college students. (I'm not sure there's a good, cost-effective solution, other than to provide more secure options to users who want them.)
- scottydelta 12y agoHow can they double the password using the hashes? Are they storing password in plaintext? :O
- deckar01 12y agoThis strange rule could coexist with hashed passwords: if(hash(password) != passwordHash) return false; if(passwordUpdateTime < heartBleedTime) { changePasswordHash(hash(password + password)); return false; } return true;
- alfredxing 12y agoHere at UBC all accounts (students, faculty, staff) must have their passwords updated every year. They force you to do it with 3 "skips" available (for if you really don't have time).
- achille2 12y agoLooking at a (failed) login flow, it looks like they are using Oracle SSO Markers: * Cookie named site2pstoretoken * Http header: Oracle-Application-Server-10g/10.1.2.3.0 Oracle-HTTP-Server * Layouts are still done via <tables>
- cm2187 12y agoAm I the only one alarmed by the general inability of websites to protect sensitive information? There isn't almost a day without a major service leaking passwords or personal details. If we don't get a LOT better at this there will be some major reaction sooner or later, either legislative or in term of public behaviour. Like the government establishing a system of licenses to have the right to handle personal data, or with regular costly audit. But we can't continue at the current pace.
- yAnonymous 12y agoUnacceptable. They should have AT LEAST trippled the passwords.
- MrSourz 12y agoThat's maybe the next step to prompt the user to change! Or even better make it forwardssdrawrof though that feels a bit evil. (forwards then reverse)
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