Amazon Joins Google In Making Censorship Easy, Threatens Signal For Circumventing Censorship Regimes

from the consequences dept

A couple weeks ago we wrote about the unfortunate decision by Google to stop enabling domain fronting on its AppEngine. As we explained at the time, this was an (accidental) way of hiding certain traffic by using the way certain large companies had set up their online services, such that censors in, say, Iran or China, couldn't distinguish which traffic was for an anti-censorship app, and which was for others. The two largest services that enabled this were Google and Amazon, and a variety of different anti-censorship tools made use of the ability to effectively "hide" within those sites such that an authoritarian government couldn't block their apps without blocking all of Google or Amazon or whatever. Some CDNs have admitted that they don't allow it out of a fear for how it could impact other users on the system, but on the whole it appeared to be a useful, if unintended, way for Google and Amazon to do good in the world.

However, when Google shut it down, the company just said that it was never supported, and the company had no plans to bring it back. Among the companies who relied on domain fronting is the popular encrypted communications app Signal. In a new blog post, Signal has explained why it believes Google suddenly decided to take action:

Direct access to Signal has also been blocked in Iran for the past 3+ years, but it was not possible to use the same domain fronting technique there. In an apparently unique interpretation of US sanction law, Google does not allow any requests from Iran to be processed by Google App Engine. Requests would get past Iranian censors, but then Google themselves would block them.

In early 2018, a number of policy organizations increased pressure on Google to change their position on how they were interpreting US sanction law so that domain fronting would be possible from Iran. Sadly, these lobbying efforts seem to have had the opposite effect. When Google’s leadership became more aware of domain fronting, it generated internal conversations about whether they wanted to put themselves in the situation of providing cover for sites that entire countries wished to block.

A month later, we received 30-day advance notice from Google that they would be making internal changes to stop domain fronting from working entirely.

That is... quite unfortunate. But, the story gets even worse. Because Signal then switched to Amazon, which resulted in the following chain of events:

With Google no longer an option, we decided to look for popular domains in censored regions that were on CloudFront instead. Nothing is anywhere near as popular as Google, but there were a few sites that used CloudFront in the Alexa top 50 or 100. We’re an open source project, so the commit switching from GAE to CloudFront was public. Someone saw the commit and submitted it to HN. That post became popular, and apparently people inside Amazon saw it too.

HN being Headline News. Amazon's response was even more stark than Google's. First, it sent Signal an email claiming that Signal was already violating its terms of service:

Yesterday AWS became aware of your Github and Hacker News/ycombinator posts describing how Signal plans to make its traffic look like traffic from another site, (popularly known as “domain fronting”) by using a domain owned by Amazon -- Souq.com. You do not have permission from Amazon to use Souq.com for any purpose. Any use of Souq.com or any other domain to masquerade as another entity without express permission of the domain owner is in clear violation of the AWS Service Terms (Amazon CloudFront, Sec. 2.1: “You must own or have all necessary rights to use any domain name or SSL certificate that you use in conjunction with Amazon CloudFront”). It is also a violation of our Acceptable Use Policy by falsifying the origin of traffic and the unauthorized use of a domain.

Signal points out, in response, that it's not actually violating Amazon's terms. It's not using security certificates from any other site, and it's not falsifying the origin of traffic when users get to Cloudfront (it's just tricking the censors in places like Iran). But, either way none of that matters much, because Amazon then announced that it was following Google's lead and killing domain fronting, claiming (again) that it doesn't want other Amazon cloud customers to find out that someone is effectively hiding behind their domain.

Signal admits that this more or less means the end of being able to use domain fronting to avoid censorship in heavily censored countries. It says it will look for alternative ideas, but in the meantime, this could do serious harm to people in those countries. There is, perhaps, a reasonable argument that we shouldn't have needed to rely on Google and Amazon as ways to hide traffic for important apps like Signal, but the fact that it was used for years this way really highlights how little damage domain fronting really seemed to do compared to the wider benefit.

With Google Cloud and AWS out of the picture, it seems that domain fronting as a censorship circumvention technique is now largely non-viable in the countries where Signal had enabled this feature. The idea behind domain fronting was that to block a single site, you’d have to block the rest of the internet as well. In the end, the rest of the internet didn’t like that plan.

We are considering ideas for a more robust system, but these ecosystem changes have happened very suddenly. Our team is only a few people, and developing new techniques will take time. Moreover, if recent changes by large cloud providers indicate a commitment to providing network-level visibility into the final destination of encrypted traffic flows, then the range of potential solutions becomes severely limited.

In short, this isn't a particularly good look. Google and Amazon made these moves so that people don't call them out for "protecting" apps like Signal by hiding their traffic behind the domains of totally uninvolved third-parties. Which certainly leaves both companies to being called out for favoring the interests of their customers over the interests of the public -- especially those in countries with authoritarian regimes. And, again, the "cost" to Google and Amazon was not high. No one was free riding, they were just doing a bit of misdirection to get around a censor's block. And now that's gone.

Filed Under: censorship, circumvention, domain fronting, signal
Companies: amazon, google, open whisper systems, signal

Feds Gagged Encrypted Communications Firm Open Whisper Systems Over Massively Overbroad Subpoena

from the and-then-backed-down dept

This morning the ACLU announced that it had convinced the government to remove a ridiculous gag order on a subpoena that had been sent to Open Whisper Systems, the makers of the popular Signal encrypted messaging app, and whose encrypted communication protocol is used by many others, including WhatsApp, Facebook and Google for their encrypted messaging offerings. It's not that surprising that a grand jury would issue a subpoena to Open Whisper Systems demanding "subscriber name, address, telephone numbers, email addresses, method of payment, IP registration, IP history logs and addresses, account history, toll records, upstream and downstream providers, any associated accounts acquired through cookie data, and any other contact information from inception to the present" for certain accounts being investigated. But, of course, Open Whisper Systems has basically none of that data. It "complied" with the subpoena to the extent that it could, which is basically that the only information it has is when the account was created and the last time it was accessed: As Marcy Wheeler rightly points out, the request itself is way too broad, covering information that the government is not allowed to ask for under ECPA (Electronic Communications Privacy Act). But, it's not like the government feels it needs to follow its own laws anyway...

The really concerning part about this, however, is that the subpoena came with an unnecessary and likely unconstitutional gag order. The gag order was, at least, bounded. After years of the DOJ issuing gag orders with no end date, at least this one was limited to one year. However, as the ACLU pointed out, a gag order needs to meet a pretty high bar to get over the fairly large First Amendment hurdle. And this one did not do that:

A magistrate judge signed the gag order, citing “reason to believe that notification of the existence of the . . . subpoena will seriously jeopardize the investigation [under prosecution by the grand jury], including by giving targets an opportunity to flee or continue flight from prosecution, destroy or tamper with evidence, change patterns of behavior, or notify confederates.”

Of course, those risks could be real, and the government’s need for secrecy in law enforcement investigations cannot be dismissed outright. But that general interest applies in virtually every criminal investigation, including those involving the public execution of search warrants. To meet the stringent First Amendment standard, any gag must be justified by something much greater. The First Amendment requires that to close courtrooms or seal evidence—and especially to prohibit a party from speaking publicly on a matter of public concern—the government demonstrate a compelling interest in secrecy, and it must apply that secrecy in the narrowest possible way. But instead, the government appears to seek blanket gag orders by default, without considering precisely what information can be disclosed without harm to its interests.

Open Whisper Systems went to the ACLU. The ACLU reached out to the government with a friendlier version of "WTF?" -- and the government basically backed down immediately, more or less admitting that the gag order was bogus:

To its credit, the government quickly agreed with us that most of the information under seal could be publicly disclosed. But the fact that the government didn't put up too much of a fight suggests that secrecy—and not transparency—has become a governmental default when it comes to demands for our electronic information, and critically, not everyone has the resources or the ability to work with the ACLU to challenge it.

OWS immediately recognized that even though the government required some secrecy over the subpoena, it did not need, nor could it justify, total secrecy. So OWS came to us, and we went to the government, which agreed to reverse its original demand for secrecy—and now OWS’s customers and the broader public can see for themselves just how wildly overbroad the government’s gag order was from the jump. And while this—the only one ever received by OWS—is now public, there are many more like it, hiding in the filing cabinets in the U.S. attorney’s offices across the country.

Of course, this leaves the big open question implied by the ACLU's statement above: how many other companies have also received unconstitutional gag orders, and simply complied? The larger tech companies have gotten much better (in the post-Snowden era) of pushing back against such gag orders, but for smaller companies it's likely that many are just complying, because they don't have either the resources or knowledge that this kind of thing is not actually allowed.

Filed Under: 1st amendment, encrypted communications, encryption, gag order, signal, subpoena
Companies: aclu, open whisper systems