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A comment on OVH Security Incident.

Re:OVH Security Incident by Robin_Message on Monday July 22, 2013 @11:02AM (#6084079)
If I was a customers, I'd be asking if "based on SHA-512" means some kind of iterated algorithm, or if have they lost my password?
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Re:OVH Security Incident by eli on Monday July 22, 2013 @11:25AM (#6084281)
It doesn't matter; you should assume your password is lost.

Follow their advice: "we advise you to change the password for your user name."

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Re:OVH Security Incident by Robin_Message on Monday July 22, 2013 @11:36AM (#6084378)
It matters a great deal (well, not to me, I don't use the service). Password reuse is common, and the way to fix that is good quality password hashing. If I used OVH, I'd need to change my password everywhere now.

If I used someone competent (i.e. they still have bugs but they use bcrypt), they'd have lost: $2a$10$NkYCXBjWeVP0rJUlfl0VL.d66EvJjbVUA/YEsmBSyTZOnbY0/anxa which is a bcrypt hash of my most secure password.

I'm happy to publish that. The salted SHA-512? Not so much!

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Re:OVH Security Incident by Tobu on Monday July 22, 2013 @11:53AM (#6084505)
Password reuse is still bad, your password doesn't have to be breached through a database dump. You could be accessing a compromised site, or get caught by any number of network attacks from stripping to mixed scripting to dumping a stream that doesn't have forward secrecy. https://www.imperialviolet.org/2012/07/19/hope9talk.html
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Re:OVH Security Incident by Robin_Message on Monday July 22, 2013 @12:11PM (#6084630)
My point was, if they hash properly, a simple db dump is not a big deal (although obviously considering the password compromised is sensible, and password reuse is a bad idea which is not a proof people don't do it).

I'm signing out of this thread as my point seems to have been lost somewhere. Thanks for the interesting link though.

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Re:OVH Security Incident by makira on Monday July 22, 2013 @11:45AM (#6084452)
Password reuse is a really bad idea, regardless of how the password is stored. Depending on how the server is comprised, your password could be intercepted before it is hashed. Don't reuse passwords for sensitive stuff.
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Re:OVH Security Incident by Robin_Message on Monday July 22, 2013 @11:51AM (#6084492)
And yet.
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Re:OVH Security Incident by eli on Monday July 22, 2013 @01:06PM (#6085013)
No, the password should now be considered compromised regardless of how it was hashed and regardless of how many other sites you used it on and how annoying it would be to change them all.
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Re:OVH Security Incident by agsamek on Monday July 22, 2013 @11:56AM (#6084525)
> I'm happy to publish that

foolhardiness is not bravery ;)

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Re:OVH Security Incident by pavs on Tuesday July 23, 2013 @01:06AM (#6088336)
$2a$10$NkYCXBjWeVP0rJUlfl0VL.d66EvJjbVUA/YEsmBSyTZOnbY0/anxa == hunter2
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Re:OVH Security Incident by w0rd-driven on Monday July 22, 2013 @02:35PM (#6085610)
"based on" could literally mean "some shit our lead developer cooked up that's like SHA but not really."

I would hope "based on" doesn't mean that but why use the phrasing at all? Either it's SHA-512 or it isn't and if it isn't, confidence is definitely not instilled.

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Re:OVH Security Incident by tommis on Monday July 22, 2013 @02:43PM (#6085675)
Not everyone is native english speaker. He means the password is salted and SHA-512 hashed...
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Re:OVH Security Incident by mikeash on Monday July 22, 2013 @11:12AM (#6084162)
That jumped out at me as well. People need to understand that even cryptographic hashes cannot be considered irreversible for short inputs, and that you need to use something specifically designed as a password hash to do it properly.
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Re:OVH Security Incident by hbbio on Monday July 22, 2013 @11:09AM (#6084141)
Maybe SHA-512, salted?
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Re:OVH Security Incident by tptacek on Monday July 22, 2013 @12:10PM (#6084623)
Salted SHAx passwords are basically the entire reason GPU John The Ripper and oclHashcat exist, although SHA2-512 is significantly slower than SHA2-256, so if you're going to use a terrible SHA-based password hash, SHA2-512 is your best bet.
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Re:OVH Security Incident by JshWright on Monday July 22, 2013 @02:35PM (#6085613)
SHA512 is slower on most (all?) current GPUs, but there is plenty of hardware on which it is faster than SHA256.
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Re:OVH Security Incident by tptacek on Monday July 22, 2013 @02:44PM (#6085680)
Hm. Example?
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Re:OVH Security Incident by JshWright on Tuesday July 23, 2013 @05:24AM (#6089006)
It'll (theoretically) be faster on any hardware that supports 64 bit operations, as SHA512 ends up doing fewer block operations.

This assumes you're hashing something at least 8 bytes long, and that your hash implementation is smart enough to use the 64 bit capabilities of your platform.

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Re:OVH Security Incident by epsylon on Monday July 22, 2013 @11:14AM (#6084184)
Yep, in the french version of the message they specify that it's salted.

http://travaux.ovh.net/?do=details&id=8998

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