MD5 considered harmful

Keegan Holley keegan.holley at
Fri Jan 27 23:35:00 UTC 2012

2012/1/27 Jared Mauch <jared at>:
> On Jan 27, 2012, at 3:52 PM, Patrick W. Gilmore wrote:
>> Your network, your decision.  On my network, we do not do MD5.  We do more traffic than anyone and have to be in the top 10 of total eBGP peering sessions on the planet.  Guess how many times we've seen anyone even attempt this attack?  If you guessed more than zero, guess again.
>> I am fully well aware saying this in a public place means someone, probably many someones, will try it now just to prove me wrong.  I still don't care.  What does that tell you?
> I would generally say: If you are on a p2p link or control the network, then yeah, you don't need md5.  If you are at a shared medium (e.g.: IX) I do recommend it there, as it will help mitigate cases where someone can hijack your session by putting your IP/ASN whatnot on the router.
> The threat (Attack) never became real and we've now had enough time that even the slowest carriers are running fixed code.
> - Jared

I kind of agree that there isn't much of a vector here, but I don't
agree that MD5 hurts if done correctly.  Is it really that hard to
find a semi-secure place to store passwords for an entire company?
There's also the question of engineering standards.  Is it an aging
practice? Probably... Is it worth spending time to update it and train
everyone not to use it?  Probably not.  I'll be happy when the world
realizes that it's ok to let gig-e auto-negotiate.  I've never really
seen MD5 cause issues.

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