x86 is a high-level language
Just so you know, x86 machine-code is now a "high-level" language. What instructions say, and what they do, are very different things.I mention this because of those commenting on this post on OpenSSL's "constant-time" calculations, designed to avoid revealing secrets due to variations in compute time. The major comment is that it's hard to do this perfectly in C. My response is that it's hard to do this even in x86 machine code.
Consider registers, for example. Everyone knows that the 32-bit x86 was limited to 8 registers, while 64-bit expanded that to 16 registers. This isn't actually true. The latest Intel processors have 168 registers. The name of the register in x86 code is really just a variable name, similar to how variables work in high-level languages.
So many registers are needed because the processor has 300 instructions "in flight" at any point in time in various stages of execution. It rearranges these instructions, executing them out-of-order. Everyone knows that processors can execute things slightly out-of-order, but that's understated. Today's processors are massively out-of-order.
Consider the traditional branch pair of a CMP (compare) followed by a JMPcc (conditional jump). While this is defined as two separate instructions as Continue reading
What ever it is, CISA isn’t cybersecurity
In the next couple months, Congress will likely pass CISA, the Cybersecurity Information Sharing Act. This is a bad police-state thing. It will do little to prevent attacks, but do a lot to increase mass surveillance.They did not consult us security experts when drafting this bill. If they had, we would have told them the idea doesn’t really work. Companies like IBM and Dell SecureWorks already have massive “cybersecurity information sharing” systems where they hoover up large quantities of threat information from their customers. This rarely allows them to prevent attacks as the CISA bill promises.
In other words, we’ve tried the CISA experiment, and we know it doesn’t really work.
While CISA won’t prevent attacks, it will cause mass surveillance. Most of the information produced by countermeasures is in fact false-positives, triggering on innocent anomalies rather than malicious hackers. Your normal day-to-day activities on the Internet occasionally trigger these false-positives. When this information gets forwarded to law enforcement, it puts everyone in legal jeopardy. It may trigger an investigation, or it may just become evidence about you, for example, showing which porn sites you surf. It’s mass surveillance through random sampling.
That such mass surveillance is the goal Continue reading
GitHub won because it’s social-media
Today Google shut down Google Code, because GitHub has taken over that market. GitHub won not because Git is a better version-control system, but because it became a social-media website like Facebook and Twitter. Geeks like me express ourselves through our code. My GitHub account contains my projects just like Blogger contains my blogs or Twitter contains my tweets.
To be sure, Git's features are important. The idea of forking a repo fundamentally changed who was in control. Previously, projects were run with tight control. Those in power either accepted or rejected changes made by others. If your changes were rejected, you could just fork the project, making it your own version, with your own changes. That's the beauty of open-source: by making their source open, the original writers lost the ability to stop you from making changes.
However, forking was discouraged by the community. That's because it split efforts. When forks became popular, some people would contribute to one fork, while others would contribute to the other. Drama was a constant factor in popular open-source projects over the evil people who "hurt" projects by forking them.
But with Git, forking is now encouraged. Indeed, that's now the first step Continue reading
No, the CIA isn’t stealing Apple’s secrets
The Intercept news site by Glenn Greenwald is activism rather than journalism. Their stories don't reference experts knowledgeable about subjects, but only activists who are concerned about the subjects. This was demonstrated yet against in their piece claiming "The CIA Campaign to Steal Apple's Secrets". Yes, the Snowden documents are real, but pretty much everything else is made up.Here's the deal. Terrorist leaders use iPhones. They are a status symbol, and status symbols are important to leaders. Moreover, since Apple's security is actually pretty good, terrorists use the phones for good reason (most Android devices suck at security, even the Blackphone).
When CIA drones bomb a terrorist compound, iPhones will be found among the bodies. Or, when there is a terrorist suspect coming out of a dance club in Karachi, a CIA agent may punch them in the face and run away with their phone. However, it happens, the CIA gets phones and wants to decrypt them.
Back in 2011 when this conference happened, the process of decrypting retrieved iPhones was time consuming (months), destructive, and didn't always work. The context of the presentation wasn't that they wanted to secretly spy on everyone's phones. The context was Continue reading
Some notes on DRAM (#rowhammer)
My twitter feed is full of comments about the "rowhammer" exploit. I thought I'd write some quick notes about DRAM. The TL;DR version is this: you probably don't need to worry about this, but we (the designers of security and of computer hardware/software) do.There are several technologies for computer memory. The densest, and hence cheapest-per-bit, is "DRAM". It consists of a small capacitor for each bit of memory. The thing about capacitors is that they lose their charge over time and must be refreshed. In the case of DRAM, every bit of memory must be read them re-written every 64-milliseconds or it becomes corrupt.
These tiny capacitors are prone to corruption from other sources. One common source of corruption is cosmic rays. Another source is small amounts of radioactive elements in the materials used to construct memory chips. So, chips must be built with radioactive-free materials. The banana you eat has more radioactive material inside it than your DRAM chips.
The upshot is that capacitors are unreliable (albeit extremely cheap) technology for memory which readily get corrupted for a lot of reasons. This "rowhammer" exploit works by corrupting the capacitors by overwriting adjacent rows hundreds of thousands Continue reading
Cliché: Safen Up!
RSA Conference is often a mockery of itself. Yesterday, they posted this tweet:
This is similar to the Simpsons episode where Germans buy the power plant. In fear for his job, Homer (the plant's Safety Inspector) starts going around telling people to "Stop being so unsafe!".
Security is not a platitude; insecurity is not a moral weakness. It's a complex set of tradeoffs. Going around telling people to "safen up" will not improve the situation, but will instead breed resentment. Infosec people are widely disliked because of their moralizing.
The only way to be perfectly secure is to cut the cables, turn off the machines, thermite the drives, and drop the remnants in a deep ocean trench. Anything less and you are insecure. Learn to deal with insecurity instead of blaming people for their moral weaknesses.
Exploiting the Superfish certificate
As discussed in my previous blogpost, it took about 3 hours to reverse engineer the Lenovo/Superfish certificate and crack the password. In this blog post, I described how I used that certificate in order to pwn victims using a rogue WiFi hotspot. This took me also about three hours.The hardware
The setup is shown above. You see the little Raspberry Pi 2 computer, with a power connection at the upper left, an Ethernet at the lower-left, and the WiFi to the right. I chose an "Alfa AWUS050NH" WiFi adapter, but a lot of different ones will work (not all, but most). You can probably find a good one at Newegg or Amazon for $10. Choose those with external antennas, though, for better signal strength. You can't really see it in this picture, but at Continue reading
Extracting the SuperFish certificate
I extracted the certificate from the SuperFish adware and cracked the password ("komodia") that encrypted it. I discuss how down below. The consequence is that I can intercept the encrypted communications of SuperFish's victims (people with Lenovo laptops) while hanging out near them at a cafe wifi hotspot. Note: this is probably trafficking in illegal access devices under the proposed revisions to the CFAA, so get it now before they change the law.I used simple reversing to find the certificate. As reported by others, program is packed and self-encrypted (like typical adware/malware). The proper way to reverse engineer this is to run the software in a debugger (or IDApro), setting break point right after it decrypts itself. The goal is to set the right break point before it actually infects your machine -- reversers have been known to infect themselves this way.
The ghetto way is to just to run this on a machine, infecting yourself, and run "procdump" (by @markrussinovich) in order to dump the process's memory. That's what I did, by running the following command:
procdump -ma VisualDiscovery.exe super.dmp
The proper reversing is to actually tear apart the memory structures, such Continue reading
Some notes on SuperFish
What's the big deal?
Lenovo, a huge maker of laptops, bundles software on laptops for the consumer market (it doesn't for business laptops). Much of this software is from vendors who pay Lenovo to be included. Such software is usually limited versions, hoping users will pay to upgrade. Other software is add supported. Some software, such as the notorious "Ask.com Toolbar", hijacks the browser to display advertisements.
Such software is usually bad, especially the ad-supported software, but the SuperFish software is particularly bad. It's designed to intercept all encrypted connections, things is shouldn't be able to see. It does this in a poor way that it leaves the system open to hackers or NSA-style spies.
Marc Rogers has a post where he points out that what the software does is hijack your connections, monitors them, collects personal information, injects advertising into legitimate pages, and causes popup advertisement.
Marc Rogers has a post where he points out that what the software does is hijack your connections, monitors them, collects personal information, injects advertising into legitimate pages, and causes popup advertisement.
What's the technical detail?
It does two things. The first is that SuperFish installs a transparent-proxy (MitM) service on the computer intercepting browser connections. I don't know the details of exactly how they do this, but Windows provides easy hooks for such interception.
But such interception still cannot decrypt SSL. Therefore, SuperFish Continue reading
Technical terms are not ambiguous
I see technical terms like "interference" and "authorization" in laws. As a technical person, this confuses me. I have a different understand of these terms than how the courts might interpret them. Courts insist that these words must be interpreted using their common everyday meanings, not their technical meanings. Yet, situations are inherently technical, so the common meanings are ambiguous.Take for example the law that forbids causing radio interference:
No person shall willfully or maliciously interfere with or cause interference to any radio communications of any station licensed or authorized by or under this chapter or operated by the United States Government.Interference seems like a common, non-technical term, but it's unlikely that's the meaning here. Interference has a very technical meaning, as demonstrated by this long Wikipedia article on "radio interference". There are entire books dedicated this this subject. It's a big technical deal, it's unreasonable to think the law means anythings else.
This is important when looking at the recent "Marriott WiFi Jamming" case, because Marriott did not cause "radio interference" or "jamming". Instead, what they did was send "deauth" packets. Using a real world analogy, jamming is like a locked door, blocking access against Continue reading
No, you can’t make things impossible to reverse-engineer
I keep seeing this Wired article about somebody announcing a trick to make software "nearly impossible" to reverse-engineer. It's hype. The technique's features are no better at stopping reverse-engineering than many existing techniques, but has an enormous cost on the system that makes it a lot worse.We already have deterrents to reverse-engineering. Take Apple iTunes, for example, which has successfully resisted reverse-engineering for years. I think the last upgrade to patch reverse-engineered details was in 2006. Its anti-reverse-engineering techniques aren't wonderful, but are instead simply "good enough". It does dynamic code generation, so I can't easily reverse engineer the static code in IDApro. It does anti-debugging tricks, so I can't attach a debugger to the running software. I'm sure if I spent more time at it, I could defeat these mechanisms, but I'm just a casual reverse-engineer who is unwilling to put in the time.
The technique described by Wired requires that the software install itself as a "hypervisor", virtualizing parts of the system. This is bad. This is unacceptable for most commercial software, like iTunes, because it would break a lot of computers. It might be acceptable for really high-end software that costs more than the computer, in Continue reading
Explaining the Game of Sony Attribation
Attribution is a blame game. It’s not about who did it, but who is best to blame. Ambulance chasing lawyers sue whoever has the most money, not who is most responsible. I point this out because while the U.S. “attributes” the Sony hack to North Korea, this doesn’t mean North Korea did the attack. Instead, it means that North Korea was involved enough to justify sanctions. It still leaves the question of “who did it” unresolved.The situation is comparable to the recent terrorist attack on Charlie Hebdo in France. Two brothers committed the crime, but “Al Qaeda of the Arabian Peninsula” (AQAP) claims credit. The precise facts are murky, but we have a good idea what happened. While AQAP probably provided some training, it appears the attack was conceived, planned, financed, and executed by the two brothers themselves without AQAP help. The brothers took out bank loans and purchased the weapons from the criminal (not terrorist) underground. They appear to have planned the attacks with a friend from ISIS (the Islamic “Caliphate”), an organization hostile to AQAP. It appears most of their training was in France rather than during their trip to AQAP camps in Yemen. AQAP waited Continue reading
A lesson in the corrupt press
In the last few days, both President Obama and Republican presidential candidate Chris Christie made similar statements about vaccination. They both said that parents should absolutely vaccinate their children, but that it's still ultimately the parent's choice (and not government's). While the statements were similar, the press reported these stories completely differently. They praised Obama for calling for vaccination, and lambasted Christie for siding with anti-vaxxers on parental choice.The White House's statement is the following:
The President certainly believes that these kinds of decisions are decisions that should be made by parents, because ultimately when we’re talking about vaccinations, we’re typically talking about vaccinations that are given to children. But the science on this, as our public health professionals I’m sure would be happy to tell you, the science on this is really clear.
Christie's statement is the following:
Mary Pat and I have had our children vaccinated and we think that it’s an important part of being sure we protect their health and the public health. I also understand that parents need to have some measure of choice in things as well, so that’s the balance that the government has to decide.
The thing is, not only is Continue reading
Nobody thought BlackPhone was secure — just securer
An exploitable bug was found in BlackPhone, a "secure" Android phone. This is wildly misinterpreted. BlackPhone isn't a totally secure phone, such a thing is impossible. Instead, it's a simply a more secure phone. I mention this because journalists can't tell the difference.
BlackPhone is simply a stock version of Android with the best settings and with secure apps installed. It's really nothing different than what you can do with your own phone. If you have the appropriate skill/knowledge, you can configure your own Android phone to be just like BlackPhone. It also comes with subscriptions to SilentCircle, a VPN service, and a cloud storage service, which may be cheaper as a bundle with installed separately on the phone.
BlackPhone does fork Android with their "PrivateOS", but such a fork is of limited utility. Google innovates faster than a company like BlackPhone can keep up, including security innovations. A true fork would quickly become out of date with Google's own patches, and hence be insecure. BlackPhone is still new, so I don't know how they plan on dealing with this. Continually forking the latest version of Android seems the most logical plan, if not convincing Android to accept their changes.
The Continue reading
Some notes on GHOST
I haven't seen anybody compile a list of key points about the GHOST bug, so I thought I'd write up some things. I get this from reading the code, but mostly from the advisory.Most things aren't vulnerable. Modern software uses getaddrinfo() instead. Software that uses gethostbyname() often does so in a way that can't be exploited, such as checking inet_addr() first. Therefore, even though software uses the vulnerable function doesn't mean it's actually vulnerable.
Most vulnerable things aren't exploitable. This bug is hard to exploit, only overwriting a few bytes. Most of the time, hackers will only be able to crash a program, not gain code execution.
Many exploits are local-only. It needs a domain-name of a thousand zeroes. The advisory identified many SUID programs (which give root when exploited) that accept such names on the command-line. However, it's really hard to generate such names remotely, especially for servers.
Is this another Heartbleed? Maybe, but even Heartbleed wasn't a Heartbleed. This class of bugs (Heartbleed, Shellshock, Ghost) are hard to exploit. The reason we care is because they are pervasive, in old software often going back for more than a decade, in components used by other software, and Continue reading
You shouldn’t be using gethostbyname() anyway
Today's GHOST vulnerability is in gethostbyname(), a Sockets API function from the early 1980s. That function has been obsolete for a decade. What you should be using is getaddrinfo() instead, a newer function that can also handle IPv6.The great thing about getaddrinfo() is the fact that it allows writing code that is agnostic to the IP version. You can see an example of this in my heartleech.c program.
x = getaddrinfo(hostname, port, 0, &addr);
fd = socket(addr->ai_family, SOCK_STREAM, 0);
x = connect(fd, addr->ai_addr, (int)addr->ai_addrlen);
What you see here is your normal call to socket() and connect() just use the address family returned by getaddrinfo(). It doesn't care if that is IPv4, IPv6, or IPv7.
The function actually returns a list of addresses, which may contain a mixture of IPv4 and IPv6 addresses. An example is when you lookup www.google.com:
[ ] resolving "www.google.com"
[+] 74.125.196.105:443
[+] 74.125.196.147:443
[+] 74.125.196.99:443
[+] 74.125.196.104:443
[+] 74.125.196.106:443
[+] 74.125.196.103:443
[+] [2607:f8b0:4002:801::1014]:443
My sample code just chooses the first one in the list, Continue reading
Needs more Hitler
Godwin's Law doesn't not apply to every mention of Hitler, as the Wikipedia page explains:
Godwin's law applies especially to inappropriate, inordinate, or hyperbolic comparisons with Nazis. The law would not apply to mainstays of Nazi Germany such as genocide, eugenics, racial superiority, or to a discussion of other totalitarian regimes, if that was the explicit topic of conversation, because a Nazi comparison in those circumstances may be appropriate.Last week, I wrote a piece about how President Obama's proposed cyber laws were creating a Cyber Police State. The explicit topic of my conversation is totalitarian regimes.
This week, during the State of the Union address, I compared the text of Mein Kampf to the text of President Obama's speech. Specifically, Mein Kampf said this:
The state must declare the child to be the most precious treasure of the people. As long as the government is perceived as working for the benefit of the children, the people will happily endure almost any curtailment of liberty and almost any deprivation.Obama's speech in support of his cyber legislation says this:
No foreign nation, no hacker, should be able to shut down our networks, steal our trade secrets, or Continue reading
Drums of cyberwar: North Korea’s cyber-WMDs
People ask me if today's NYTimes story changes my opinion that North Korea didn't do the Sony hack. Of course it doesn't. Any rational person can tell that the story is bogus. Indeed, such stories hint the government is hiding something.The story claims the NSA has thoroughly hacked North Korea since 2010, and that's what enabled the US government to tell who was responsible for the Sony hack. But if this were true, then we hacked first, and the Sony hack is retaliation -- meaning we had no justification for Obama's sanctions. But, if the story is false, then again sanctions against North Korea aren't justified, because we don't have the proof our government claims. True or false, this story means the U.S. sanctions against North Korea aren't justified.
The reason this story is nonsense is that it's not journalism. It relies almost entirely on anonymous sources in the government. These aren't anonymous whistle-blowers who fear retaliation, but government propagandists who don't want to be held accountable. The government exploits the New York Times, promising them exclusive breaking news in exchange for them publishing propaganda. This allows government to have a story that is simultaneous true and false, Continue reading
Notes on the CIA spying case
The CIA announced it wasn't going to punish those responsible for spying/hacking on Senate computers. Since journalists widely get this story wrong, I thought I'd write up some notes getting it right. That's because while the CIA organization is guilty of gross misconduct, it's actually likely that no individual employees did anything wrong. The organization is guilty, but (possibly) the people aren't.The first thing to note is that no hacking happened. These were CIA computers, at a CIA facility, managed by CIA sysadmins, who had the admin passwords.
That's the complicated bit. In 2009 when the Intelligence committee demanded to look at the torture/interrogation documents, the CIA balked about the security issues of staffers taking documents offsite. Therefore, they came to an agreement with the Senate: the CIA would set up a special secured network at their building, disconnected from the rest of the CIA network. The Senate staffers would go there to work. Documents would be transferred from the CIA's main network onto this special network by hand (probably USB flash drive or something).
The Senate committee didn't have to agree to this. By law, they have oversight, and can make decisions that screw the CIA. But the Continue reading
Obama’s War on Hackers
Ha ha. New York Times accidentally posted their employee database to their website: SSN, passwords, and salaries: https://t.co/1dLdUXG2tT
— Rob Graham (@ErrataRob) January 14, 2015In next week's State of the Union address, President Obama will propose new laws against hacking that could make either retweeting or clicking on the above link illegal. The new laws make it a felony to intentionally access unauthorized information even if it's been posted to a public website. The new laws make it a felony to traffic in information like passwords, where "trafficking" includes posting a link.
You might assume that things would never become that bad, but it’s already happening even with the current laws. Prosecutors went after Andrew “weev” Auernheimer for downloading a customer list AT&T negligently made public. They prosecuted Barret Brown for copying a URL to the Stratfor hack from one chatroom to another. A single click is all it takes. Prosecutors went after the PayPal-14 for clicking on a single link they knew would flood PayPal’s site with traffic.
Even if you don’t do any of this, you can still be guilty if you hang around with people who do. Obama proposes upgrading hacking to a “racketeering” offense, Continue reading