Full Disclosure mailing list archives
Re: Expired certificate
From: Dan Kaminsky <dan () doxpara com>
Date: Sat, 17 Jul 2010 09:23:18 -0700
Junk, X.509 always has another way it falls over in the field. Expiration management is one of those ways. In theory, it's no big deal to swap out an expired cert for a valid one. In reality, it's a time bomb, of the sort that usually doesn't exist. Does the output of gcc have a 'run by' date? Will your Cisco router simply fail to move traffic six months from now? Perhaps the only thing vaguely akin to certificate failure is hard drive failure -- but imagine if drives *intentionally* committed suicide one day after warranty expire. People would go nuts! Somehow, this is all OK in X.509. Doing an emergency change to production machine is difficult in the best of times, when there's an actual outage and the clock is ticking. In this case, the outage is basically a policy outage. The box is up, it can receive traffic, it's just the other guy needs to handle the error differently. So, they're asking for that. If you're curious *why* it's such a pain in the ass to make unplanned changes, it's because of the following process, repeated over and over again: 1) Someone needs to make a small change 2) He decides to be a bad ass and just does it 3) There's an outage because the guy screwed up 4) So said guy can keep his job, the outage is blamed on policy that clearly needs to be made stronger Repeat until outage rate drops to accepable levels. On Jul 17, 2010, at 8:56 AM, Junk Meat <junkmeat () goshawn com> wrote:
What part of my thread suggests making unplanned changes in a live environment? All that was said was the re-issuance of a certificate and it's installation is a relatively simple process. So you believe its alright to let a certificate remain expired for two weeks? Don't worry about educating me, there is nothing you have said that I don't already know... it doesn't even sound like you have anything intelligent to articulate besides petty criticism and contemptuous remarks. On 7/16/2010 5:16 PM, bk wrote:So basically you advocate making unplanned changes whenever someone feels like it? The only problem here is that they let the cert expire. Being responsible about conducting maintenance, instead of having a knee- jerk reaction, isn't to be faulted. If you think you can write better secure file transfer software, no one is stopping you. You'll make a fortune. Just remember it has to support more than half a dozen different protocols, support dozens of nodes talking to the same storage backends, synchronize data across datacenters, support triggered actions at multiple places in the transaction across multiple protocols, support multiple payload encryption protocols, allow single-sign-on authentication with third-party vendors, etc, etc, etc. Oh yeah, it all has to pass independent code-review by external auditors. At that rate, supporting instant application of new certs in a multi-tiered environment with bi-directional trust is a cake-walk in comparison. Simple, right? I'm done educating you. I know the software and I know what I'm talking about; clearly you know neither. On Jul 16, 2010, at 12:49 PM, Junk Meat wrote:chort or whatever your name is, some of us know what we're doing and don't need to wait 2 weeks for a lousy ssl cert update much less a daemon restart... give me a break. Quit defending the State of California, if they were so up on security they shouldn't have passed SB1386 or any other legislation for that matter. Certificate authorities notify their customers well in advance of expiring certs, multiple times in fact, there's no excuse for that and then expecting your clients to violate best practice afterward. As far as change control and system complexity, wise organizations keep things simple not overly complex. Shawn Dermenjian On 7/16/2010 3:11 PM, bk wrote:Maybe you should know what you're talking about before you speculate. Most daemons require a restart when you change their cert. When you're talking about a service that has guaranteed up- time, it can only be taken down for scheduled maintenance. Changing production systems on a whim totally fails the 'A' in 'CIA' (and possibly the 'I' too). Wise organizations implement change-control policies to keep their critical systems from being run-amok by ad-hoc changes. I'm familiar with the software State of California is using for a lot of their secure file transfers and changing the certificate is not as simple as you think (although the software is extremely secure). There are several cross-certification trust relationships that need to be established for the software to continue working after replacing certs. The risk of connecting to a machine with an expired cert is that the cert may have been revoked. That's why there are expiration dates on certs. Even if you're using a CRL, you cannot have the CRL contain every cert that was revoked for all of eternity. The CRL only contains certs from when they were revoked until when they expire. That keeps CRLs slightly manageable (although OCSP is a much better solution). If you're still connecting to the same IP and getting the same cert (check the serial number and/or fingerprint), then at least you're sending data to where you always have in the past. What you want to be weary of is if the serial number and/or fingerprint change and the cert is still invalid (those will probably both change when the cert is re-issued, but then the cert chain and not-before/not-after dates should be legit). -- chort On Jul 16, 2010, at 11:31 AM, Junk Meat wrote:Your right Dan, encryption still does take place. However, its hard to understand why renewing a certificate would take so long. It should take no longer then 1/2 hour to receive a renewed ssl cert from a certificate authority in my opinion and maybe a few minutes to push it out depending on the device that is publishing the cert. You should tell them that your security policy prevents you from making a secure ftp transfer to a third party with an expired certificate that contains non-public information and see how fast they renew their certificate. Basically you are now taking responsibility for any breach in the slight chance that anything does happen (man-in-the-middle, or otherwise) because you now know about the problem. Have them acknowledge the expired ssl certificate on their end and sign- off on any potential litigation that may result if a breach does happen to occur. -Shawn Dermenjian On 7/16/2010 1:10 PM, Daniel Sichel wrote:OK, I am in the Golden state (California) where things are not so golden at the moment. I deal with a state agency and use their "secure" ftp site. Their certificate has expired and won't be renewed for a few weeks, but they want me to continue to ftp stuff Using their expired cert. So, as a relative n00b, what are the risks? Does it still encrypt even though, obviously, it can't be verified? My guess is that this still encrypts, but there is no authentication, possibly creating a man in the middle opportunity for some Nefarious person with evil intent (nobody I know, or who is on this list, of course). Anyway, any info would be welcome from the cognoscenti who subscribe here. Thanks, Dan Sichel _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/_______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/_______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
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Current thread:
- Re: Expired certificate, (continued)
- Re: Expired certificate Larry Seltzer (Jul 16)
- Re: Expired certificate Dimitry Andric (Jul 16)
- Re: Expired certificate Valdis . Kletnieks (Jul 16)
- Re: Expired certificate Jan Schejbal (Jul 21)
- Re: Expired certificate Ryan Castellucci (Jul 22)
- Re: Expired certificate Dimitry Andric (Jul 16)
- Re: Expired certificate Junk Meat (Jul 16)
- Re: Expired certificate bk (Jul 16)
- Re: Expired certificate Junk Meat (Jul 16)
- Re: Expired certificate bk (Jul 16)
- Re: Expired certificate Junk Meat (Jul 17)
- Re: Expired certificate Dan Kaminsky (Jul 17)
- Re: Expired certificate Pavel Kankovsky (Jul 18)
- Re: Expired certificate Marsh Ray (Jul 20)
- Re: Expired certificate Dan Kaminsky (Jul 22)
- Re: Expired certificate Marsh Ray (Jul 22)
- Re: Expired certificate Dan Kaminsky (Jul 22)
- Re: Expired certificate Marsh Ray (Jul 22)
- Re: Expired certificate bk (Jul 23)
- Re: Expired certificate bk (Jul 16)
- Re: Expired certificate Larry Seltzer (Jul 16)
- Re: Expired certificate Meadow (Jul 23)
- Re: Expired certificate Marsh Ray (Jul 24)
- Re: Expired certificate Pavel Kankovsky (Jul 24)