Better Password Hashes

[A.J. Kehoe IV (Nanoman)]

Garance A Drosehn wrote:
>On 7/7/13 1:36 PM, A.J. Kehoe IV (Nanoman) wrote:
>> I commissioned Derek to come up with a solution by either updating
>> Steven's patch or by devising a new method. To paraphrase Derek's comments:
>>
>> -----BEGIN PARAPHRASIS-----
>> I did some research into what other *BSDs are doing. OpenBSD and NetBSD
>> use the algorithm name, a comma, and then the number of rounds:
>>
>> http://www.openbsd.org/cgi-bin/man.cgi?query=login.conf&sektion=5
>>
>> localcipher=blowfish,6
>>
>> http://netbsd.gw.com/cgi-bin/man-cgi?passwd.conf+5+NetBSD-current
>>
>> localcipher=blowfish,6
>>
>> To me, this isn't a good way to do it because we'd need special
>> rules to parse this extra field out of the previously unstructured
>> data.  This parsing would be algorithm dependant.
>
>To comment only on this point, I do not think it is a significant
>issue.  If OpenBSD and NetBSD are already doing this, then whatever
>parsing issues are already being addressed by users on those OS's.
>
>I think there is a significant advantage in using something that
>they are already using.  Now, if they say "Wow, was this a bad
>idea!", then obviously I wouldn't want to add it.  But if their
>security is better with this feature, and if *they* don't have
>major regrets with using it, then I think we should consider it.

I don't think the method used by OpenBSD and NetBSD is a bad idea, but there are a couple reasons why I prefer Derek's method:

1. Convention.  OpenBSD and NetBSD call it "blowfish", whereas FreeBSD calls it "blf", and others call it "bcrypt".  Modular Crypt Format, on the other hand, is pretty consistent across various operating systems, languages, et cetera.

2. Implementation.  Derek's method would be a relatively minimal change, whereas the other method would be a more invasive change with more things that could go wrong.

>I'd certainly want to consider other ideas too.  But I don't think
>we should cross this idea off the list just because it would be
>too much extra effort *if* we were the only OS which used it.  I
>run both FreeBSD and OpenBSD systems, and for people like me it
>will be more effort if different BSD's use incompatible methods
>to achieve better password security.  You won't be saving me any
>effort, you'll only be adding to the effort I already have.
>
>[admittedly that isn't much effort. :) ]

Maybe our OpenBSD and NetBSD colleagues will prefer Derek's idea too?  As Derek has demonstrated, it's fairly simple to implement while maintaining compatibility with the existing method.

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