- From: Serge Egelman <egelman@cs.cmu.edu>
- Date: Thu, 11 Oct 2007 20:16:02 -0400
- To: Ian Fette <ifette@google.com>
- CC: "Close, Tyler J." <tyler.close@hp.com>, public-wsc-wg@w3.org
...and in that case it's still accurate. serge Ian Fette wrote: > Well, it's still an attestation to some level. It's not an attestation > that you're talking with Google, but it is an attestation that you're > talking with google.com <http://google.com>. But beyond that I have no > good answer. > > On 10/11/07, *Serge Egelman* <egelman@cs.cmu.edu > <mailto:egelman@cs.cmu.edu>> wrote: > > Point taken. > > But what about certificates that are not attestations? E.g., anything > non-EV? > > serge > > Ian Fette wrote: > > The need to warn comes in around something like googlepages.com > <http://googlepages.com> > > <http://googlepages.com>. Right now, the management is all under > > pages.google.com <http://pages.google.com> < > http://pages.google.com> and we use a SSL cert for > > google.com <http://google.com> <http://google.com> for login etc. > But it is conceivable that > > at some point we might actually want to SSL enable > > https://www.googlepages.com for login, or who knows what. (This is > wild > > speculation, I don't work on the project, this is just an example). So > > we would then need a cert for googlepages.com > <http://googlepages.com> <http://googlepages.com>. > > But user content is located at username.googlepages.com > <http://username.googlepages.com> > > <http://username.googlepages.com>, and we really don't want to > attest to > > anything about the identity of whatever is found at those > locations. So > > when you try to load https://ifette.googlepages.com under this > scenario > > (where googlepages.com <http://googlepages.com> < > http://googlepages.com> is actually ssl enabled > > and serving up something), you had better get a warning. > > > > Subdomains are not *always* controlled (or rather, authored / attested > > to) by the owner of the higher-level domain, and it's not always a > safe > > assumption to make. You can make arguments about www being a special > > case, but beyond that... > > > > -Ian > > > > On 10/11/07, *Serge Egelman* <egelman@cs.cmu.edu > <mailto:egelman@cs.cmu.edu> > > <mailto:egelman@cs.cmu.edu <mailto:egelman@cs.cmu.edu>>> wrote: > > > > This is an error I'm trying to do some research on, maybe > someone can > > shed some light on it. There are thousands of legitimate > sites that > > have this problem, either because they don't use an alt-name, > or the > > certificate is being used on some other subdomain of their domain. > > > > In the case where one certificate is being used by another > host within > > the domain that it was legitimately issued for, I'm not > entirely sure > > what the threat model is. Sure, this is a great way for CAs > to make > > money (by either making a site buy a new certificate for every > host or > > making them buy a wildcard cert), but beyond this, what's the need > > to warn? > > > > Yes, the DNS can be hacked to add in a new hostname, but at > that point > > there are bigger problems. > > > > serge > > > > Ian Fette wrote: > > > bankofamerica.com <http://bankofamerica.com> > <http://bankofamerica.com> < > > http://bankofamerica.com> does not use an alt-name. > > > What's the point? (And for those of us who aren't using IE7, I'm > > > assuming you just get a common name mismatch error, or > what?) if eBay > > > uses it, then I think you need to be worried about breaking it. > > > > > > On 10/11/07, *Close, Tyler J.* <tyler.close@hp.com > <mailto:tyler.close@hp.com> > > <mailto: tyler.close@hp.com <mailto:tyler.close@hp.com>> > > > <mailto: tyler.close@hp.com <mailto:tyler.close@hp.com> > <mailto:tyler.close@hp.com <mailto:tyler.close@hp.com>>>> wrote: > > > > > > Perhaps there's some way to finesse this part of the > algorithm by > > > reference to RFC 2818. I'll work on it. > > > > > > Many sites don't seem to be using this cert feature. For > a fun > > > example, visit the following URL using IE7. > > > > > > https://bankofamerica.com/ > > > > > > --Tyler > > > > > > > > > ------------------------------------------------------------------------ > > > > > *From:* Ian Fette [mailto:ifette@google.com > <mailto:ifette@google.com> > > <mailto:ifette@google.com <mailto:ifette@google.com>> > > > <mailto:ifette@google.com <mailto:ifette@google.com> > <mailto: ifette@google.com <mailto:ifette@google.com>>>] > > > *Sent:* Thursday, October 11, 2007 12:48 PM > > > *To:* Close, Tyler J. > > > *Cc:* public-wsc-wg@w3.org > <mailto:public-wsc-wg@w3.org> <mailto:public-wsc-wg@w3.org > <mailto:public-wsc-wg@w3.org>> > > <mailto:public-wsc-wg@w3.org <mailto:public-wsc-wg@w3.org> > <mailto:public-wsc-wg@w3.org <mailto:public-wsc-wg@w3.org>>> > > > *Subject:* Re: clarifications needed re safe form > editor cert > > > matching algorithm > > > > > > It is in huge use. For example. if you go to > > > https://signin.ebay.com and look at the cert - the CN is > > > signin.ebay.com <http://signin.ebay.com> < > http://signin.ebay.com> > > <http://signin.ebay.com> but the certificate > > > subject alt name lists: > > > > > > Not Critical > > > DNS Name: signin.cafr.ebay.ca > <http://signin.cafr.ebay.ca> <http://signin.cafr.ebay.ca> > > < http://signin.cafr.ebay.ca> > > > DNS Name: signin.ebay.ca <http://signin.ebay.ca> > <http://signin.ebay.ca> > > < http://signin.ebay.ca> > > > DNS Name: signin.ebay.com.au > <http://signin.ebay.com.au> <http://signin.ebay.com.au> > > < http://signin.ebay.com.au <http://signin.ebay.com.au>> > > > DNS Name: signin.ebay.com.cn > <http://signin.ebay.com.cn> < http://signin.ebay.com.cn> > > <http://signin.ebay.com.cn> > > > DNS Name: signin.express.ebay.com > <http://signin.express.ebay.com> > > <http://signin.express.ebay.com> <http://signin.express.ebay.com> > > > DNS Name: signin.half.ebay.com > <http://signin.half.ebay.com> > > <http://signin.half.ebay.com> < http://signin.half.ebay.com> > > > DNS Name: signin.liveauctions.ebay.com > <http://signin.liveauctions.ebay.com> > > <http://signin.liveauctions.ebay.com> > > > < http://signin.liveauctions.ebay.com > > <http://signin.liveauctions.ebay.com>> > > > DNS Name: signin.shopping.ebay.com > <http://signin.shopping.ebay.com> > > <http://signin.shopping.ebay.com> > <http://signin.shopping.ebay.com> > > > DNS Name: signin.tw.ebay.com > <http://signin.tw.ebay.com> <http://signin.tw.ebay.com> > > <http://signin.tw.ebay.com> > > > DNS Name: signin.ebay.com <http://signin.ebay.com> > <http://signin.ebay.com> > > <http://signin.ebay.com <http://signin.ebay.com> > <http://signin.ebay.com>> > > > > > > and if you go to https://signin.ebay.de you again > get a cert > > > with CN= signin.ebay.com <http://signin.ebay.com> > <http://signin.ebay.com> < > > http://signin.ebay.com> but alt names of: > > > Not Critical > > > DNS Name: signin.befr.ebay.be > <http://signin.befr.ebay.be> <http://signin.befr.ebay.be> > > < http://signin.befr.ebay.be <http://signin.befr.ebay.be>> > > > DNS Name: signin.benl.ebay.be > <http://signin.benl.ebay.be> <http://signin.benl.ebay.be> > > <http://signin.benl.ebay.be> > > > DNS Name: signin.ebay.at <http://signin.ebay.at> > <http://signin.ebay.at> > > <http://signin.ebay.at> > > > DNS Name: signin.ebay.be <http://signin.ebay.be> > <http://signin.ebay.be> > > <http://signin.ebay.be > > > > DNS Name: signin.ebay.co.uk > <http://signin.ebay.co.uk> <http://signin.ebay.co.uk> > > <http://signin.ebay.co.uk> > > > DNS Name: signin.ebay.de <http://signin.ebay.de> > <http://signin.ebay.de> > > <http://signin.ebay.de> > > > DNS Name: signin.ebay.es <http://signin.ebay.es> > <http://signin.ebay.es> > > <http://signin.ebay.es> > > > DNS Name: signin.ebay.fr <http://signin.ebay.fr> > <http://signin.ebay.fr> > > <http://signin.ebay.fr> > > > DNS Name: signin.ebay.ie <http://signin.ebay.ie> > <http://signin.ebay.ie> < > > http://signin.ebay.ie> > > > DNS Name: signin.ebay.nl <http://signin.ebay.nl> > <http://signin.ebay.nl> > > <http://signin.ebay.nl> > > > DNS Name: signin.express.ebay.co.uk > <http://signin.express.ebay.co.uk> > > <http://signin.express.ebay.co.uk> > > > <http://signin.express.ebay.co.uk > <http://signin.express.ebay.co.uk>> > > > DNS Name: signin.ebay.com <http://signin.ebay.com> > <http://signin.ebay.com> < > > http://signin.ebay.com <http://signin.ebay.com>> > > > > > > > > > So yeah, it's important. > > > On 10/11/07, *Close, Tyler J.* <tyler.close@hp.com > <mailto:tyler.close@hp.com> > > <mailto: tyler.close@hp.com <mailto:tyler.close@hp.com>> > > > <mailto: tyler.close@hp.com > <mailto:tyler.close@hp.com> <mailto:tyler.close@hp.com > <mailto:tyler.close@hp.com>>>> > > wrote: > > > > > > > > > > > > > > > Thomas Roessler wrote: > > > > going through the matching algorithm while > folding > > it in... > > > > > > > > - The current language confuses attributes and > > fields. I > > > suspect > > > > that you mean the various attributes of the > Subject > > > certificate > > > > field. Please confirm. > > > > > > The CN, O, L, ST and C values I refer to are the > ones > > in the set > > > referred to by the Subject field in the end entity > > > certificate. Not sure > > > how to be any more specific about this in PKIXese. > > > > > > > - I notice that you have some rules that concern > > matching > > > the CN > > > > attribute, but none concerning > > subjectAltName. I'm happy to > > > > simply track this point as an issue. > > > > > > Could you point me to a document covering the > semantics of > > > subjectAltName? Is it in use in X.509 certs on > the Web? > > > > > > > Also, I'll open an issue to track the "PKI > orthodoxy" > > > remarks that > > > > Hal had made at the face-to-face, and will > link to that > > > issue from > > > > the draft. > > > > > > Thanks, > > > --Tyler > > > > > > > > > > > > > -- > > /* > > Serge Egelman > > > > PhD Candidate > > Vice President for External Affairs, Graduate Student Assembly > > Carnegie Mellon University > > > > Legislative Concerns Chair > > National Association of Graduate-Professional Students > > */ > > > > > > -- > /* > Serge Egelman > > PhD Candidate > Vice President for External Affairs, Graduate Student Assembly > Carnegie Mellon University > > Legislative Concerns Chair > National Association of Graduate-Professional Students > */ > > -- /* Serge Egelman PhD Candidate Vice President for External Affairs, Graduate Student Assembly Carnegie Mellon University Legislative Concerns Chair National Association of Graduate-Professional Students */
Received on Friday, 12 October 2007 00:16:44 UTC