On Wed, Feb 22, 2017 at 01:41:22PM +0100, Tomas Krizek wrote: > On 02/22/2017 12:28 AM, Fraser Tweedale wrote: > > On Tue, Feb 21, 2017 at 05:23:07PM +0100, Standa Laznicka wrote: > >> On 02/21/2017 04:24 PM, Tomas Krizek wrote: > >>> On 02/21/2017 03:23 PM, Rob Crittenden wrote: > >>>> Standa Laznicka wrote: > >>>>> Hello, > >>>>> > >>>>> Since we're trying to make FreeIPA work in FIPS we got to the point > >>>>> where we need to do something with MD5 fingerprints in the cert plugin. > >>>>> Eventually we came to a realization that it'd be best to get rid of them > >>>>> as a whole. These are counted by the framework and are not stored > >>>>> anywhere. Note that alongside with these fingerprints SHA1 fingerprints > >>>>> are also counted and those are there to stay. > >>>>> > >>>>> The question for this ML is, then - is it OK to remove these or would > >>>>> you rather have them replaced with SHA-256 alongside the SHA-1? MD5 is a > >>>>> grandpa and I think it should go. > >>>> I based the values displayed on what certutil displayed at the time (7 > >>>> years ago). I don't know that anyone uses these fingerprints. The > >>>> OpenSSL equivalent doesn't include them by default. > >>>> > >>>> You may be able to deprecate fingerprints altogether. > >>>> > >>>> rob > >>> I think it's useful to display the certificate's fingerprint. I'm in > >>> favor of removing md5 and adding sha256 instead. > >>> > >> Rob, thank you for sharing the information of where the cert fingerprints > >> are originated! `certutil` shipped with nss-3.27.0-1.3 currently displays > >> SHA-256 and SHA1 fingerprints for certificates so I propose going that way > >> too. > >> > > IMO we should remove MD5 and SHA-1, and add SHA-256. But we should > > also make no API stability guarantee w.r.t. the fingerprint > > attributes, i.e. to allow us to move to newer digests in future (and > > remove broken/no-longer-secure ones). We should advise that if a > > customer has a hard requirement on a particular digest that they > > should compute it themselves from the certificate. > > > > Cheers, > > Fraser > What is the motivation to remove SHA-1? Are there any attacks besides > theoretical ones on SHA-1? > > Do other libraries already deprecate SHA-1? > Come to think of it, I was thinking about SHA-1 signatures (which are completely forbidden in the public PKI nowadays). But for fingerprints it is not so bad (for now).
Thanks, Fraser -- Manage your subscription for the Freeipa-devel mailing list: https://www.redhat.com/mailman/listinfo/freeipa-devel Contribute to FreeIPA: http://www.freeipa.org/page/Contribute/Code
