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from the honestly,-it's-for-your-own-good... dept.
Safari will, later this year, no longer accept new HTTPS certificates that expire more than 13 months from their creation date. That means websites using long-life SSL/TLS certs issued after the cut-off point will throw up privacy errors in Apple's browser.
The policy was unveiled by the iGiant at a Certification Authority Browser Forum (CA/Browser) meeting on Wednesday. Specifically, according to those present at the confab, from September 1, any new website cert valid for more than 398 days will not be trusted by the Safari browser and instead rejected. Older certs, issued prior to the deadline, are unaffected by this rule.
By implementing the policy in Safari, Apple will, by extension, enforce it on all iOS and macOS devices. This will put pressure on website admins and developers to make sure their certs meet Apple's requirements – or risk breaking pages on a billion-plus devices and computers.
[...] Shortening the lifespan of certificates does come with some drawbacks. It has been noted that by increasing the frequency of certificate replacements, Apple and others are also making life a little more complicated for site owners and businesses that have to manage the certificates and compliance.
"Companies need to look to automation to assist with certificate deployment, renewal, and lifecycle management to reduce human overhead and the risk of error as the frequency of certificate replacement increase," Callan told us.
We note Let's Encrypt issues free HTTPS certificates that expire after 90 days, and provides tools to automate renewals, so those will be just fine – and they are used all over the web now. El Reg's cert is a year-long affair so we'll be OK.
GitHub.com uses a two-year certificate, which would fall foul of Apple's rules though it was issued before the cut-off deadline. However, it is due to be renewed by June, so there's plenty of opportunity to sort that out. Apple's website has a year-long HTTPS cert that needs renewing in October.
Microsoft is an interesting one: its dot-com's cert is a two-year affair, which expires in October. If Redmond renews it for another two years, it'll trip up over Safari's policy.
(Score: 2, Informative) by Anonymous Coward on Monday February 24 2020, @09:52PM (15 children)
Are they really though? Certificate Authorities are only supposed to issue certificates with lifetimes shorter than ~27 months and the all the major engines reject ones longer than ~39 months. Chromium is already working to shorten it to 397 days in their next few releases and all browsers voted to support the proposal at the last meeting.
The real issue here is with accidental infrastructure abandonment and revocation. People already hijack neglected domain names that people forget to check up on. Big companies get hit by expiring certificates all the time. Letting servers just sit with no oversight for multiple years is just asking to get hijacked, exploited, etc.
Then you get to revocation. CRLSets are unwieldy and not complete by design. CRLs and OCSP are not checked by many browsers. Short of having a valid must-staple response, many browsers won't notice anything is wrong. With lifespans a little over two years (if the issuer is actually compliant with the best practice), your stolen/revoked certificate will continue to be a danger to everyone for years to come. For example, try https://revoked.badssl.com [badssl.com] or https://revoked.grc.com [grc.com] or https://www.digicert.com/digicert-root-certificates.htm [digicert.com] revoked demos to see how your browser handles it. There is a good chance that your browser will allow at least one and most versions of Chromium explicitly blacklist the badssl one in order to fool most people into thinking it's safe; otherwise it would allow ALL of them.
(Score: 5, Interesting) by sjames on Tuesday February 25 2020, @12:32AM (7 children)
If Apple and Google were actually serious about cert security, they would actually implement revocation.
(Score: 0) by Anonymous Coward on Tuesday February 25 2020, @03:11AM (6 children)
No argument there. But even so CRLs can be huge, as they need to contain every non-expired certificate that has been revoked, which can slow down browsers as they have to wait to download the whole thing. OCSP is also a privacy concern, as now the CAs know every time you check a website, and is subject to replay attacks. Both of them also suffer from what should happen if the CRL or OCSP server is unavailable and no cached copy exists.
Just like many standards, revocation fell to the side for many reasons, chief among them being the need for speed.
(Score: 3, Informative) by Pino P on Tuesday February 25 2020, @04:17AM (5 children)
Not if the web server checks the OCSP responder (say) once an hour, retrieves a response signed and timestamped by the CA, caches it, and includes it with the server's certificate whenever the client makes a connection. This is called OCSP stapling [cloudflare.com].
How so, given that responses are timestamped and expire promptly?
Likewise if the DNS server goes down or the origin web server goes down.
(Score: 0) by Anonymous Coward on Tuesday February 25 2020, @05:57AM (4 children)
You should check the stats for how many websites actually do OCSP stapling, it is the hundredths of a percent. Which means that if you do OCSP at all, you will be making the request yourself to the address in the certificate.
OCSP itself (including stapled ones) are vulnerable to replay attacks because the default OCSP interval for most providers is 7 days, with some going into multiple weeks (the last time I checked) and most web servers use the OCSP TTL for their cache length as well. For a non-stapled OCSP response, MITM only needs to get a single response, as the vast majority of CAs' servers do not honor the optional nonce value in the request and stapled responses don't use a per-client nonce anyway, which means everyone gets the same response. In addition, unless you "must-staple," it is a soft fail anyway.
And, unlike a DNS or web server problem, which admins are aware of and usually somewhat control themselves, CRL and OCSP servers are run by the CAs. You have no control over their availability or redundancy. If your DNS goes down, you can propagate changes over the NS network or have redundant providers in the first place. Your web server goes down, you can spin up a new one or have redundancy in the first place. Your CA has an outage, then there is literally nothing you can do about it. And that is if you are made aware of the problem at all.
(Score: 3, Interesting) by driverless on Tuesday February 25 2020, @10:56AM
CAs don't have redundancy, they have reduncandy. They're only as reliable as the least secure subsystem, and a failure in any of the many brittle parts will take you down with it.
(Score: 2) by driverless on Tuesday February 25 2020, @10:58AM
It's not the vast majority, per a survey carried out a few years ago no public CA honours the nonce. In other words every CA trusted by your browser is vulnerable to a replay attack because they completely ignore the nonce that's present to prevent the attack.
(Score: 2) by Pino P on Tuesday February 25 2020, @02:49PM (1 child)
Source please. The article I linked above ("High-reliability OCSP stapling and why it matters" by Nick Sullivan [cloudflare.com]) states that sites that use Cloudflare have been stapling since 2016 when Cloudflare introduced proactive fetching of OCSP responses as they near the typical 7-day expiration window.
What incidents have been reported of unexpired OCSP responses being used to forge connections on a recently revoked certificate?
Unless the VPS provider is having an outage. For example, an SSD outage on Google Compute Engine in December 2019 [google.com] brought down the Discord chat service [discordapp.com] among other sites.
(Score: 0) by Anonymous Coward on Tuesday February 25 2020, @10:58PM
https://www.ssllabs.com/ssl-pulse/ [ssllabs.com] shows that around 32.6% currently staple at all. According to censys, 190,921 certificates must-staple [censys.io] and 446,079,247 certificates don't [censys.io]. Even if the number were tilted so that the must-staple ones had 999 SANs and the "non-must-staple" had zero, then at best less than 30% of the domain names would be must-staple. A more reasonable number on either end of that for SANs just makes the percentage of must-staple sites worse.
It is a theoretical vulnerability, you asked how it was possible which two people explained. Even if there was an incident where it occurred, it may not be reported or widely publicized. But that doesn't change the fact that such a theoretical vulnerability exists, especially against those MITMed by someone or other situations.
And yes, lots of things can have outages, but an OCSP failure is not one of those you can plan for, work around, or have redundancy over (unlike your VPS example) without having multiple certificates from different providers spread around your infrastructure in advance or ready to go. And again, that is if you even notice the problem in the first place.
(Score: 4, Informative) by driverless on Tuesday February 25 2020, @03:35AM (6 children)
That assumes it's a public web site. A helluva lot of certs get used for things like SCADA/IoT/embedded, and they're on RFC 1918 addresses and the like and are self-signed, you typically provision the device once at built time and that's it. If there's a compromise, you take the device offline or reflash it with clean firmware, there's no need for revocation handling or all the other X.509 bollocks.
Except that now you can't any more because Apple has decided you need to rebuild/reprovision your device every twelve months for no reason whatsoever. In the case of SCADA gear that can never go down, it just means that you can't use Safari to talk to embedded systems any more, or at least not after the first twelve months' uptime.
(Score: 2) by All Your Lawn Are Belong To Us on Tuesday February 25 2020, @11:03AM (5 children)
I think you have that a little backwards, if I understand the summary. You can't use Safari to talk to embedded systems any more unless you're within 12 months of whatever expiration date they set, not within 12 months of start uptime.
Even then, if you can get dating on the cert maybe you could just edit your system time to link up with it? You wouldn't do that for the general web, but for a SCADA/IoT/embedded device maybe you would. That, and the earlier, is predicated on Apple looking at the expiration date of the cert only and comparing to today, not taking the issue date/expiration date and calculating the difference.
If it were universal that might even be a way to foil script-kiddie level hacks trying to use browsers for IoT stuff. Give your certs some ridiculous dating so no browser will recognize it unless your clock is changed to match. It's not really security but it is a layer of obfuscation.
This sig for rent.
(Score: 3, Interesting) by driverless on Tuesday February 25 2020, @11:11AM (4 children)
Doesn't work because it would break all Internet sites with correct times because cert, CRL, and OCSP times would be out. Another cool security feature, your clock is off so the CRL is future-dated so we'll assume the cert is invalid and won't let you connect. Or at least Firefox does that.
(Score: 2) by Pino P on Tuesday February 25 2020, @02:28PM (3 children)
Then use one clock setting to connect to SCADA and a different clock setting to connect to public websites.
(Score: 3, Informative) by tangomargarine on Tuesday February 25 2020, @03:43PM (2 children)
We're going off into the weeds here. The far simpler solution is for Safari to not be dumb.
"Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"
(Score: 2) by Pino P on Tuesday February 25 2020, @08:45PM (1 child)
"To not be dumb" is a tall task for Safari or any other proprietary or tivoized software.
(Score: 2) by driverless on Tuesday February 25 2020, @11:24PM
Or for security people in general. Security people are supposed to provide guide rails, but most of the time they just make a roadblock.