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Automatic HTTPS Enforcement for New Executive Branch .gov Domains (cio.gov)
88 points by konklone on Jan 19, 2017 | hide | past | favorite | 78 comments



This is fantastic news.

It wasn't that long ago that I tried to log into a government site via my SSN, and discovered that the page didn't even permit HTTPS. I was displeased, to say the least; logging in wasn't exactly optional, so it seemed much worse than a business offering poor security.

Permitting HTTPS is obviously the first step, but security shouldn't be limited to people with the expertise to seek it out. I'm really glad to see that something as inescapable as the .gov domain will be pursuing security-by-default.


Please name and shame the httpd that's asking for plaintext SSNs... That's newsworthy and I'm sure some tech journalists will pick it up on a slow day.


It was a state jobs site which has since updated to HTTPS. They still suck in a lot of ways - the required login is SSN, plus an 8-digit (numeric only) PIN. That's a laughably bad login scheme, but at least they aren't passing it in the clear.

If I do see it again, is there anything like a clearinghouse for this sort of complaint?


Co-author of the post here, happy to answer questions. =)

This is a GSA initiative, not an 18F initiative. But 18F has a recent post detailing executive branch progress on HTTPS that may also be relevant:

https://18f.gsa.gov/2017/01/04/tracking-the-us-governments-p...


The blog post is unclear. On a technical level (on the preload list), is the enforcement at the TLD level or is it just a legal requirement to submit all .gov domain names to the preload list? If the latter, any plan to move to the former?


Not quite either one -- it's technical enforcement by the TLD, but still done on a per-domain basis (this doesn't affect state/local .gov domains, or legislative/judicial .gov domains). The dotgov.gov program will forcibly preload new domains, but it's not feasible to just submit ".gov" to the preload list right now.


Any plans to force IPv6 adoption in the same manner?



Fantastic! Thanks!


IPv6 is pretty low priority compared to comprehensive HTTPS support.

Disclaimer: Not USDS/18F, just tech professional.


Oh I agree, but the two things can be done at the same time. Especially for new .gov sites.

It appears a lot of .gov sites already support IPv6 but I was wondering if it's an official policy or just at the discretion of the tech team.


Does this include DOD? I suspect DOD is probably already doing this, but just wonder if they fall under the umbrella.


DoD does have some .gov domains, so it would affect them in that way. But .mil is not affected.


The DoD has a massive PKI system already and makes the assumption users of its sites have the appropriate CAs installed. (Home access typically requires installing a set of them, typically bundled separately or in an installer)


DoD uses https and crypto at the transport layer in SIPR. Lots of "type 1" crypto as well, which is its own special thing with NSA issued hardware crypto keys.


If anyone works in the Canadian government and wants my input in getting the political support to make this happen in your department, I've been helping some departments understand the nature of the risks (some are even paying me as a consultant!) of MITM attacks. It's taking time, but I'm slowly seeing improvement. I can give you some tips as to how to properly communicate the importance of some of these and other measures (like getting monitors like Appcanary installed to watch for security vulnerabilities).

My email is in my profile :)


As a practical question: what is the expected capacity of the preload stores of browsers? Hundreds of thousands, millions or much more domains? Because at some point it seems like everyone with moderately high security requirements may want to have their certificates pinned / preloaded.


I think that's an open question. Right now, it's not the millions, that'd be too much to bundle with browsers. But browsers may well change their delivery mechanism for preload information to allow this to scale higher.

In any case, .gov won't add much to the load -- right now there are all of 5,500 .gov domains, and the rate of adding/removal is on the order of dozens every month at most.


> right now there are all of 5,500 .gov domains

Is that just domains from which web content is hosted, or just second level domains regardless of whether web content is hosted? Because I can't imagine that there are only 5,500 total .gov domains.


Second level domains. There are waayyyyy more subdomains, as you note. You can see some information and estimates on this here:

https://18f.gsa.gov/2017/01/04/tracking-the-us-governments-p...

We (18F, me) personally measured at least 26,000 (though some of these are used as redirects or are just error pages, etc.).


My browser's disk footprint is already over 100MB. What's another X MB?

The ironic thing is we're reinventing the CA system, only now each browser is its own authority, exactly the problem the CA system was trying to solve.


I wouldn't say this is reinventing the CA system. You don't need to trust any particular browser here. The effect is that web services must offer a secure HTTPS connection, using the existing CA system (or an enterprise CA, if their user base is truly all-enterprise), no matter what browser is being used.


> You don't need to trust any particular browser here.

You do need to trust that the particular browser you are using supports preloaded list, and is using the latest updated version of the list, and is not missing any entries!


What you're trusting the browser for there is the extra protection that preloading provides, but that's not the whole benefit here. The larger benefit is that it makes it infeasible for services to neglect to support HTTPS. So, even if your browser's preload list is busted, the site will be guaranteed to support HTTPS because of this effort, which you'll still benefit from.


Ah ok. I think I see what you are saying now. As long as a sizeable portion of browsers support a fresh version of the preloaded list, there is sufficient customer feedback to push the servers to only support https. Right?


Exactly.


> My browser's disk footprint is already over 100MB. What's another X MB?

Don't forget mobile and other platforms, where resources are more constrained.


Seems like you could use a bloom filter to store whether a domain has a pinned cert, and then use an api provided by the browser to remotely fetch the pinned cert. This has privacy implications, but does step around the storage. Chrome does something similar for CRL, but bloom filters fit that use case better.


IIRC DuckDuckGo might do something like that for search suggestions. For slightly improved privacy, lots of unrelated hosts can be grouped into blocks (maybe grouped by probability of access to make it harder to infer which domain from the block is the likely target).


I said something similar in a reply below, but I find it interesting that this amounts to a .Gov-wide decision that availability is always less important than confidentiality and integrity.

While that's probably valid in the main, is that always true? FEMA/NOAA spring to mind. As does IRS guidance, especially since those documents should have digital signatures themselves for an additional layer of integrity.

Was this idea part of the discussion?


Bear in mind that when it comes to plain HTTP, it's not just the system's confidentiality and integrity that you need to weigh: it's the user's confidentiality and integrity. That's a larger moral responsibility, in my opinion.

These issues were already worked through for the executive branch as part of the White House HTTPS policy published in June 2015:

https://https.cio.gov/

Some rationale for "Why everything?" can be found here:

https://https.cio.gov/everything/

Personally, I'd say that plain HTTP is insecure enough, and today's internet is hostile enough, that plain HTTP provides a very weak form of "availability". It's on site operators to ensure that when their services and information is available, that it's available in a manner that doesn't subject the user to risk.


How is the user's C/I adversely affected by allowing FEMA to have a non-https subdomain for emergency alerts? That's a super easy addition to the policy: HTTPS everywhere except for GET requests to alerts.fema.gov.

I assume you know, but in case you don't, hostnames are typically outside the envelope for HTTPS. So this hypothetical GET already leaks that it's going to alerts.fema.gov. Then realize that the HTTPS cipher suites positively identified the HTTPS library being used, and packet details + origin IP leak the OS.

Edit: I'll even do you one better. Have the policy be HTTPS everywhere and HSTS everywhere but alerts.fema.gov


Yes, I do know that hostnames are typically outside the HTTPS envelope. However, user-agent is not, and would be exposed (and could then possibly be correlated to other HTTPS traffic from the same IP address). Also, potentially cookies from a previous session -- even a previous HTTPS session -- could be exposed, depending on how careless the server operator is. (You can set flags to make sure cookies only go over HTTPS, but that doesn't always happen.)

From an integrity perspective, connecting to alerts.fema.gov over HTTP does potentially subject the user to code injection attacks. Those do happen:

* https://arxiv.org/abs/1602.07128

* https://citizenlab.org/2015/04/chinas-great-cannon/

* http://www.forbes.com/sites/kashmirhill/2014/10/28/find-out-...

Now, are any of these likely to happen on an arbitrary request to alerts.fema.gov? Maybe not. (Especially since Verizon has since been fined by the FCC.) But I'm trying to point out that it's not just the service owner whose safety has to be weighed in policies like this.

FWIW, the GSA plan announced in this post is intentionally crafted to be gradual and to avoid breaking things. It only affects future domains, not present ones, and so we'll have plenty of time to see whether being a total hardass about HSTS causes negative effects. Agencies can still do specialized services on their existing domains.

There's also going to have to be some carveout somewhere for specialized services like OCSP/CRL, which are already exempted from the policy mandate that came out in June 2015:

https://https.cio.gov/guide/#are-federally-operated-certific...

But in any case, the push should be, clearly and loudly, towards changing the defaults that browsers and users accept, and I think GSA's change weighs the tradeoffs appropriately in making such a push.


From what I gather, Let's Encrypt meets the guidelines to be considered acceptable, but is not really mentioned anywhere, neither in the linked page nor on https.cio.giv - is there any feeling one way or the other on the use of Let's Encrypt for .gov?

Certainly one of the biggest headaches of the classic approach is forgetting to renew your certificate on time, a situation which Let's Encrypt effectively avoids.


Let's Encrypt isn't specifically mentioned in the post, though the post hits the underlying point:

> GSA provides extensive guidance to agencies on HTTPS deployment at https.cio.gov, and encourages .gov domain owners to obtain low cost or free certificates, trusted by the general public. As a general matter, more expensive certificates do not offer more security value to service owners, and automatic deployment of free certificates can significantly improve service owners’ security posture.

This is also repeated here:

https://https.cio.gov/certificates/#what-kind-of-certificate...

Two GSA programs automate Let's Encrypt to deploy certificates on demand:

* https://www.digitalgov.gov/2016/09/07/lets-encrypt-those-cna...

* https://cloud.gov/docs/apps/custom-domains/#managed-service-...

There's also a USG amendment to the Let's Encrypt Terms of Service that GSA negotiated with them to make it easier for agencies to use it:

https://letsencrypt.org/documents/LE-US-State-Local-SA-Amend...


Unable to click through certificate warnings = completely inaccessible when there is an issue with certificate validation. Look at the shiny new attack surface!


If there's an issue with certificate validation, the attack surface is already open.


You've forgotten that security includes availability, in addition to confidentiality and integrity. Interesting design choice for the entity which runs the emergency broadcasting system.

You're saying you'd prefer for e.g. NOAA to not be able to issue tornado warnings in order to ensure nobody can fake a tornado warning.


I think what konklone was getting at is that any scenario that allows an attacker to trigger a certificate warning (and effectively taking down the service) would also allow them to take down the service through other means. Do you have a scenario in mind that doesn't require either a MitM (who could just as well block the service) or a compromised client/server (which would allow the attacker to block access either way)?


This response implies that it the reduced available need be malicious, it could be non-intentional as well.

ex:

During an emergency I connect to public wifi because mine is not working. That wifi has a MITM proxy installed by the owner (because they want to server ads over https, it's a developer's wifi and they were testing with something like charles proxy, etc). This page is now unavailable during an emergency. Thus lack of availability without malicious intent.

The general assumption for HSTS is that, in all cases, it's better to be unavailable than have the possibility of compromise. I'm unsure if that's the case for critical services in times of need.


Well, it doesn't have to be an attack per se. Maybe the client's clock is wrong, which actually happens a lot. Or admin error replacing the cert on the server. There are of course lots of ways admin error can take down a server, but https adds some fun possibilities that are easier to trigger and harder to recover from.


Bonus points for client clock error. If I had a nickel for every time...

The best is when it's a timezone issue and the distant end responds with "I have 0 drift, must be a problem on your end". Crypto is hard, time is hard. Crypto which relies on time...


I mean, sure, there's more things that can go wrong once you add TLS to the stack. At the same time, there are so many other guns to shoot yourself in the foot with, so why is that we should draw the complexity trade-off line between HTTP and HTTPS? HTTPS seems to be good enough for 50% of all page loads nowadays. There's no active attack scenario here (which I agree would be a concern for critical services!), and for every possible TLS server or client issue, there are a multitude of other server, network or browser issues that could have a similar effect.


The point of this thread has been that adding additional complexity, whatever its form, makes services more fragile. You might not be aware of this, but there was recently a Treasury CA delegated from the Federal Common Policy root CA whose cert expired. This caused every system downstream to have to go through and update their CA bundles. There was significant pain because systems with hsts enabled trying to connect to web services with the wrong cert bundle caused exactly the type of outage we've been discussing. This is not a hypothetical, there were systems with days/weeks of downtime caused by (mostly) human error. The fact that other things can go wrong too does not mean that things going wrong because of HTTPS isn't a problem. It's a trade-off, like everything in security.

Managing certs is work. People get it wrong sometimes. Mandatory hsts means no "just click allow" safety net. This decision takes away the ability to accept that risk for systems where availability is more important.


If I screw up max connections or keep alive or some such in nginx.conf I can revert that change with downtime limited to the duration of the bad change. Screw up HPKP with a bad cert roll and you can't just revert. Users will be bifurcated into before and after groups, and you can't fix that without waiting it out.


Very true. HPKP is not part of this change, and if you look at GSA's guidance on HPKP, it's cognizant of this risk:

https://https.cio.gov/certificates/#http-public-key-pinning


Oh, HPKP is definitely something you'll want to think about hard before committing to. Getting a publicly-trusted certificate from any of the myriad of CAs out there, on the other hand, is no rocket science.


You might want to re-read my post more carefully, there is not necessarily an attacker per-se in an availability incident (although there certainly could be. Depends on how evil one wants to think.).

Backhoe eats the fiber to the ocsp responder and CRL distribution point, CRLs timeout after 24 hours.

Boom, as the kids are saying.


> You might want to re-read my post more carefully, there is not necessarily an attacker per-se in an availability incident (although there certainly could be. Depends on how evil one wants to think.).

Well, that was the context of this thread. Both the OP and konklone are talking about attack surface. If you want to talk about how running a service via TLS and using HSTS makes HA harder, that's a different discussion.

> Backhoe eats the fiber to the ocsp responder and CRL distribution point, CRLs timeout after 24 hours.

OCSP and CRL is soft-fail by default in all browser I'm aware of. The server is also in control of it via OCSP Stapling, so it has all the tools it needs to keep the server available, assuming proper configuration and monitoring (which is true for a HTTP service as well).


Is the backhoe/squirrel/hurricane an attacker thus making this an "attack"? Semantics. Availability is part of the attack _surface_, which if we're being pedantic is what was being discussed. ("Look at the shiny new attack surface!")

> different discussion

My point is that, no, it's not. The three points of the triad are inextricably linked. More C and/or I means less A (and A tends to be sidelined in favor of C and I these days).

> OCSP and CRL is soft-fail by default in all browser I'm aware of.

Not on government systems they aren't (STIG id: v-44789). Also, if we're going all in on https we should go all in on https.

> ... Stapling

How is the server supposed to get a response to staple if the responder is unavailable?

Also, time. Also, client root of trust. Also, fat-fingering the hostname when the DNS gets updated. Also, public wifi which does mitm...

Bottom line: this is a decision which prioritizes confidentiality and integrity over availability for the entire .gov with (seemingly) no recourse.

Edit: quote from upstream, corrected STIG id


To quote my comment from above - bear in mind that when it comes to plain HTTP, it's not just the system's confidentiality and integrity that you need to weigh against availability: it's the user's confidentiality and integrity.

That's a larger moral responsibility, in my opinion. And consider that the fallback to prioritize availability in case of a non-attack cert error (e.g. revocation or expiration) is to ask the user to look at a certificate warning and make a personal trust decision about it. There are precious few users who can safely make that kind of a decision. And even if they "get it right" that time and click through and aren't attacked, you're training users to click through warnings, and helping them subject themselves to attacks in the future.

I would argue that that kind of "availability" is a very weak sort of availability. The government has enough problems with training people to click through certificate warnings (see: https://www.iad.gov) -- intentionally leaving that hole open seems unwise.


> Not on government systems they aren't (STIG id: v-44789). Also, if we're going all in on https we should go all in on https.

I found this description: "By setting this policy to true, the previous behavior is restored and online OCSP/CRL checks will be performed. If the policy is not set, or is set to false, then Chrome will not perform online revocation checks. [...]"

This seems to address the fact that Chrome does not perform OCSP queries at all, instead relying on its CRLSets. However, even back when Chrome did OCSP queries, it was soft-fail (as is every other browser). The "previous behavior" would thus be to query OCSP, but fail silently anyway.

> How is the server supposed to get a response to staple if the responder is unavailable?

OCSP responses from publicly-trusted CAs are typically valid for 10 days, and they're updated at least once every 4 days (IIRC). That'll leave 6 days for the responder to come back online in the worst case (or 6 days to tell everyone about "badidea" in case the CA is nuked from orbit, along with any other publicly-trusted CA the site might switch to). (Let's not forget it's soft-fail, so this is just a theoretical exercise).

> Bottom line: this is a decision which prioritizes confidentiality and integrity over availability for the entire .gov with (seemingly) no recourse.

I'll give you that. I just don't think the availability concerns are bad enough to outweigh the benefits, and they can be mitigated in just about any scenario.


What are the odds that the private keys for all of the .gov domains are also sent to the NSA? I guess if you are worried about another nation spying on your traffic you would be fine. I would expect that all of this traffic is decryptable by NSA though.


Gov employee here (18F).

If the operative word is "sent" and "all" the likelihood is zero, as I can assert I've never sent a private key to NSA, and I've made quite a few over the past few years.

That said, carlosdp makes a great point as to how one should behave. Even though not all private keys get shipped to NSA (can't make claims about other teams), the government is very public about other data sharing programs (see https://www.dhs.gov/sites/default/files/publications/privacy... for example).

Even though all government agencies must disclose these types of programs, they are so numerous and often so difficult to decipher, the only rational response is to assume everyone has everything or could have access in the future.

The only way to avoid this is to build zero-knowledge systems on the server side, something I hope you'll see more of in 2017.


I think we can pretty safely assume all information given to the government is in the hands of government agencies, one way or another.


Would you otherwise have an expectation that your data sent to the government would be kept secret from the NSA?


What are you getting at? As far as I know, OMB doesn't require key escrow, so it almost certainly doesn't happen at scale. I'd imagine that if an intelligence service asked an agency for keymat, they'd happily provide it. I know that I wouldn't have a problem with someone from old St. Elizabeths Hospital or Fort Meade or Crystal City asking me for stuff, especially since the order to co-ooperate with DHS or NSA or the Pentagon would come through the agency's chain of command.

That said, DHS runs an intrusion prevention system called EINSTEIN, whose mission is to protect all federal civilian computer networks:

https://en.wikipedia.org/wiki/Einstein_(US-CERT_program)

Using EINSTEIN _is_ mandated by OMB, so if you're worried about the U.S. federal government snooping on your communications with the U.S. federal government, I don't know what to tell you.


I think it's safe to assume that would be impossible to keep secret. The number of people that would need to be "in on it" is huge.

I can vouch personally that at least one civilian department doesn't do this.


Do you really have a policy that would survive an NSA-directed evil-sysadmin attack from any of the participants in your chain of trust? As a civilian branch of the government?

It's pretty hard to setup a system that would survive an powerful adversary who simply didn't know your passwords, have access to your safes, etc. But to then make that system hardened against a malicious insider with get-of-of-jail card?!


It would have to be one of the four people with root.

Multiply this by the number of groups that operate a .gov website (it's a lot) compounded by turnover (even more.) And account for the cat-herders needed to organize it and do it every time the private key rotates (no less than yearly for our internet-facing sites.)

There are a lot of ways you could do this on a small scale, but you really can't scale up this particular mechanism and keep it secret.


> It would have to be one of the four people with root.

Or anyone who'd ever gotten access to the computer, or installed a camera near it, etc.

The critical part of that answer though, is "one of the". The system fails if any of the individuals is be malicious. A more-robust system would require multiple malicious agents in various organizational silos (security, compliance, management) to fail.

> every time the private key rotates

Well, if I got in once it probably phones that home for me.

> you really can't scale up this particular mechanism and keep it secret

Well, it isn't secret. We know the NSA intercepts hardware to muck with it, when needed. Much easier even than planting something in your server room explicitly. Also, they wield NSLs compelling silence and cooperation. It's not like being discovered here or there would stop scare or stop them.

It would probably scale pretty well given that this is the extreme; most people just generate keys on the old debian box in the corner.


> A more-robust system would require multiple malicious agents in various organizational silos (security, compliance, management) to fail.

Yes, and at that point the name for it is "policy". These are our own keys after all- nobody would blink an eye if they were supposed to be collected.

They're not.


> They're not. [keys not collected by another agency]

Right. I think you're absolutely correct, now. And I fully expect (hope!) that the NSA will one-day come to you with some more-secure hardware and that you will gladly cooperate because as you say - we are all on the same team.

My point is that you can't say what you're saying now. You aren't secure, and you don't have the type of procedures that would ever let you get to more than a 4/10 or so. You don't even see having four independent points of failure as an issue, rather than a benefit.

By promising people that the NSA does not have your organization's keys you're providing the less technical with a false picture.

And maybe, one day, that might matter. You might trick the next leaker into trusting your org as a way to whistle-blow and cause them to be caught by the NSA before they reach the news.

> Yes, and at that point the name for it is "policy". [security procedures]

Yeah, and software is just automated policy. If this is a zero, and that's a zero, etc...

If the guard in the vault runs a non-exploitable policy (ie no "I'm the boss" backdoors) then you can greatly reduce evil-sysadmin attacks.


Sorry, I'm not going to continue arguing with you. It's clear you don't understand the scope of what you're proposing is happening.


I'm just saying you're making claims you cannot possibly verify. You say nobody is collecting your keys even though all you have is a lack of evidence either way. I also think you're probably, accidentally, right in this case. But only because I doubt you really have adversaries who care.

You're confusing being uninteresting with being safe. (Safety is numbers is irrelevant once you've been selected.)

> Sorry, I'm not going to continue arguing with you.

Stop clicking Reply.


Strangely, many tech folks seem to have normalized some very wild fantasies about what the NSA does.


I'm using the NSA as an example of a foe of sufficient capability, not saying that this is what they do (to our own agencies at any rate.) Someone who can trojan hardware, suborn any given person, etc.

I was hoping to use a very advanced force as an example to show that things that may sound secure aren't if your attacker has a certain level of resources.

Fwiw, most pen-testers would aso be able to bypass any such casually enacted system too, but that's less obvious so I had hoped to avoid that argument by going with an extreme example.


It should really be .gov.us rather than a top level domain.


.gov, .mil, and .edu predate the existence of country-code TLDs. They're a legacy of when the Internet was a US government funded research project.

You could argue that since the Internet has become a global commercial network, the US should no longer have these special, exclusive TLDs. But switching over would be a ton of work, and there really aren't enough downsides to the US having these domains to justify a change.

It's worth noting that .fed.us exists, although hardly any government sites us it. State/city governments often use .[state].us domains since .gov was originally restricted to the federal government, but that restriction was lifted and it's common to see .gov used for state/local governments now as well.


On the other hand, if we put in that effort now we won't have to listen to people who know nothing about how the internet came to be, and are indignant and shocked that the US government should have special treatment, for the next N decades. Seems almost worth it to me...


I think it is a nice little historical artifact. When someone asks why, then can tell the story of the internet's creation.


In fact, there are now way more state/local .gov domains (~4,000) than federal .gov domains (~1,300).


How has this been enforced? and what about sub-domains?


Subdomains generally get automatically included when a second-level domain is preloaded. So, for .gov domains that fall under scope here, their subdomains will all have HTTPS enforced by modern web browsers.

Web browsers enforce preloading by considering each domain as having HTTP Strict Transport Security (HSTS) set, and so it gets the strict treatment: only https:// connections, and no clicking through certificate warnings.

Some more detail on all this here: https://https.cio.gov/hsts/


I've contracted for a few of the larger agencies and that's just not true. Their DNS's can route sub-domains to several (hundreds) different sites/servers where there is no, and continues to be no, https


@prodtorok - This is one of the nice things about HSTS. The includeSubDomains directive can create automatic client enforcement for all subdomains. If some component of an agency ignores this and doesn't configure HTTPS, they'll find that users of modern browsers won't be able to access the site.

The one downside of includeSubDomains is that, with dynamic HSTS (without preloading), you have to get the user to visit https://agency.gov to "see" the HSTS header once to get that coverage. Visiting https://www.agency.gov or http://agency.gov won't do it.

So another benefit of preloading is that you remove that problem from the table -- browsers will enforce HTTPS for all subdomains, even if the user has never visited the root site. It's a powerful tool, and there is no analogue for other protocols (like IPv6 or DNSSEC) to set policies for an entire zone that you can expect most clients to enforce.


thanks, ill look into it!


HSTS preloading enforces "includeSubDomains" for all domains that are submitted[1]. It's certainly possible to use HSTS without includeSubDomains, but not preloaded HSTS, and since all new executive branch domains will be preloaded, that means all subdomains will have to support HTTPS as well.

[1]: https://hstspreload.org/




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