A Post-Mortem on ZDNet’s Smear Campaign

A few days after I gave a talk at the HOPE/X conference titled, “Identifying Backdoors, Attack Points, and Surveillance Mechanisms in iOS Devices”, ZDNet published what their senior editor has described privately to me as an opinion piece, however passed it off as a factual article in an attempt to make headlines at my expense. Now that things have had time to settle down, I’ve taken the time to calmly write up a post-mortem describing what actually happened as well as some behind-the-scenes details that may shed some light on the drama we’ve seen from ZDNet and one of its writers over the past couple of weeks. Let me say first that this is the last time I will address this matter, and have no desire to continue to discuss it, or engage with ZDNet or their writer. In fact, I haven’t engaged with either parties since this all transpired a week or so after my talk, in spite of repeated attempts to bait me with more personal attacks and false claims of harassment.

At HOPE/X, I gave a very carefully-worded talk describing a number of “high value forensic services” that had not been disclosed by Apple to the consumer (some not even to developers), such as the com.apple.mobile.file_relay service, which I admitted to the audience as having “no better word for” to describe than as a “backdoor” to bypass the consumer’s backup encryption on iOS devices; this doesn’t necessarily mean a nefarious backdoor, but can simply be an engineering backdoor, like how supervisor passwords or other mechanisms work – a simple bypass to make things convenient. A number of news agencies reached out to me, and I took time to explain to each journalist that this was nothing to panic about, as the threat models were very limited (specifically geared towards law enforcement forensics and potentially foreign espionage). Also, that I did not believe there was any conspiracy here by Apple. Reporters from ARS Technica, Reuters, The Register, Tom’s Guide, InfoSec Institute, and a number of others spoke to me and got all the time they wanted. You can see that these journalists each published relatively balanced and non-alarmist stories; even The Register, who prides themselves on outlandish headlines, if you read their story, was actually quite level headed about the matter. A number of other news agencies, who had not reached out to me, published sensationalist stories with crazy claims of an NSA conspiracy, secret backdoors, and other ridiculous nonsense. I tried very hard to throw cold water on those ideas both in my talk and in big letters on my first blog entry, with”DON’T PANIC” and instructions for journalists.

ZDNet was among the news agencies that had initially published a sensationalist story without approaching me first for questions.

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Apple is Making Progress

Apple’s new, relaxed NDA rules appear to allow me to talk about the iOS 8 betas. I will hold off on the deep technical details until the final release, as I see that Apple is striving to make a number of improvements to the overall security of their product. What I will say is that so far, things look quite promising. Shortly after my talk at HOPE/X, citing my paper, “Identifying Backdoors, Attack Points, and Surveillance Mechanisms in iOS Devices”, along with a proof of concept, Apple released Beta 5, and a number of the “high value forensic services” I’d outlined in my paper have now been disabled wirelessly, including the packet sniffer service that got many upset (note: we’ve known about the packet sniffer for years, but it was never disclosed to consumers that it was active outside of developer mode). Apple’s fixes are clearly still a work in progress, and not all of my security concerns have been addressed yet, but it does show that Apple does care about the security of their product, and likely wants to prevent their APIs from being abused by both malicious hackers and government. Given that a number of my threat models involved government spying, it feels good to know that Apple has taken my research seriously enough to address these concerns. Keep in mind, the threat model we’re dealing with also includes foreign governments, many of which have long histories of spying on our country’s diplomats. I’ve instructed a number of counter-forensics classes to diplomatic infosec personnel, and the threats of spying on data are very real for these people, to the degree that a lot of cloak-and-dagger goes into play on both sides, especially when visiting technologically hostile countries.

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Apple’s Authentication Scheme and “Backdoors” Discussion

I’ve heard a number of people make an argument about Apple’s authentication front-ending the services I’ve described in my paper, including the “file relay” service, which has opened up a discussion about the technical definition of a backdoor. The primary concern I’m hearing, including from Apple, is that the user has to authenticate before having access to this service, which one would normally expect would preclude a service from being a backdoor by some (but not all) definitions. This is a valid point, and in fact I acknowledge this thoroughly in my paper. Let me explain, however, why this argument about authentication is more complicated and subtle than it seems.

Most authentication schemes are encapsulated from weakest to strongest, and are also isolated from one another; certain credentials get you into certain systems, but not into others. You may have a separate password for Twitter, Facebook, or other accounts, and they only interoperate if you’re using a single sign-on mechanism (for example, OAuth) to use that same set of credentials on other sites. If one gets stolen, then, only the services that are associated with those credentials can be accessed. Those authentication mechanisms are often protected with even stronger authentication systems. For example, your password might be stored on Apple’s keychain, which is protected with an encryption that is tied directly to your desktop password. Your entire disk might also be encrypted using full disk encryption, which protects the keychain (and all of your other data) with yet another (usually stronger) password. So you end up with a hierarchy of authentication mechanisms that get protected by stronger authentication mechanisms, and sometimes even stronger ones on top of that. Apple’s authentication scheme for iOS, however, is the opposite of this, where the strongest forms of authentication are protected by the weakest – creating a significant security problem in their design. The way Apple has designed the iOS authentication scheme is that the weakest forms of authentication have complete control to bypass the stronger forms of authentication. This allows services like file relay, which bypasses backup encryption, to be accessed with the weakest authentication mechanisms (PIN or pair record), when end-users are relying on the stronger “backup encryption password” to protect them.

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Oxygen Forensics: Latest Forensics Tool to Exploit Apple’s “Diagnostic Service” to Bypass Encryption

While Apple’s claims may be that a key subject of my talk, “Identifying Backdoors, Attack Points, and Surveillance Mechanisms in iOS Devices” (com.apple.mobile.file_relay) is for diagnostics, a recent announcement from the makers of the fantastic Oxygen Forensics suite shows strong evidence that law enforcement forensics is continuing to take every legal technical option available to them to acquire data. Whether Apple really does use file relay for diagnostics or not, we may never know, but the service is most definitely being used for other purposes, many of which raise some serious privacy concerns.

To give you an idea of how this “diagnostic service” is being used to bypass security in iOS devices, have a look at their latest press release. At the very top, you will a see a service not unlike that of many other commercial forensics tools that have similar functionality:

Screen Shot 2014-07-31 at 3.42.43 PM

It’s very clear from reading this description that they’re describing the file_relay service here, which serves no end-user purpose, and was not disclosed by Apple in any way until after my talk. This key service, as I’ve explained, bypasses the backup encryption that end-users and large enterprises (via MDM’s “force encrypted backups” mechanism) can set to protect data from being dumped in clear text from their device. You can read my research for actual threat models and caveats to this, so as not to rush to panic.

Oxygen, just like many other forensics tools, is widely used by government, law enforcement, military, and intelligence communities. Certainly, nobody can fault any of these software manufacturers for taking advantage of such services to bypass security features in mobile devices like the iPhone. They’re not the only ones either; a number of other commercial vendors do the same thing, and will continue to until Apple closes off the hole.

If Apple was not aware that their self-dubbed “diagnostics service” was being exploited in this fashion, they are now. It is my hope that they will close their service off completely, or cause it to respect backup encryption in future versions of iOS.

Roundup of iOS Backdoor (AKA “Diagnostic Service”) Related Tech Articles

There are a lot of terrible news articles out there, and a lot of terrible “journalists” who have either over-hyped my research, or dismissed it entirely. After ZDNet’s utterly horrible diatribe about my research, I posted a proof-of-concept to help further clarify that was and wasn’t possible. Unfortunately, the FUD has continued, and so I thought it would make sense to help provide readers with some middle-of-the-road, and easy-to-understand technical links that would help make sense of everything.

End users rely on backup encryption to protect the data on their phone in the event that someone either obtains physical access to an unlocked phone, or access to their computer. Enterprises rely heavily on the “force encrypted backups” MDM policy Apple provides to protect corporate trade secrets and other confidential information stored on employee phones. Having a backdoor to bypass this encryption can be very dangerous for both individuals and businesses. Additionally, the wireless component of this allows for remote and persistent monitoring, making this a potentially long term and stealth threat.

Here’s a list of the technology articles I’ve found useful at explaining my talk and slides. While there may be a few slight technical inaccuracies here or there, these are all “good reads” that overall do a good job.

New Backdoors Discovered in iOS? An Interview With iOS Developet and Digital Forensics Expert Jonathan Zdziarski
Kim Crawley, InfoSec Institute

iOS Lockdown Diagnostic Services (TL;DR)
Dino Dai Zovi, Co-Author “iOS Hacker’s Handbook”

Surveillance Mechanisms in iOS Devices – Don’t Panic but… Do Read This
Elissa Shevinsky, CEO of Glimpse

Apple iPhones allow extraction of deep personal data, researcher finds
Reuters / Joseph Menn

Is Apple’s iOS Backdoor Not a Backdoor
Wall Street Cheat Sheet / Nathaniel Arnold

iOS slurp ware brouhaha: It’s for diagnostics, honest, says Apple
The Register / Iain Thomson

Apple Snuck Backdoor Surveillance Tools Into Their (i.e. Your) iOS*
Matthew Phelan, Gawker
* The headline is sensational, as per usual, but the article itself is quite balanced

I’ve also recently posted a pastebin dump of all the personal data I was able to wirelessly retrieve off of my personal iPhone running 7.1.2 using this service to bypass backup encryption, and with “iTunes Sync” turned off.

Dispelling Confusion and Myths: iOS Proof-of-Concept

Here’s my iOS Backdoor Proof-of-Concept:
http://youtu.be/z5ymf0UsEuw

When I originally gave my talk, it was to a small room of hackers at a hacker conference with a strong privacy theme. With two hours of content to fit into 45 minutes, I not only had no time to demo a POC, but felt that demonstrating a POC of the personal data you could extract from a locked iOS device might be construed as attempting to embarrass Apple or to be sensationalist. After the talk, I did ask a number of people that I know attended if they felt I was making any accusations or outrageous statements, and they told me no, that I presented the information and left it to the audience to draw conclusions. They also mentioned that I was very careful with my wording, so as not to attempt to alarm people. The paper itself was published in a reputable forensics journal, and was peer-reviewed, edited, and accepted as an academic paper. Both my paper and presentation made some very important security and privacy concerns known, and the last thing I wanted to do was to fuel the fire for conspiracy theorists who would interpret my talk as an accusation that Apple is working with NSA. The fact is, I’ve never said Apple was conspiring secretly with any government agency – that’s what some journalists have concluded, and with no evidence mind you. Apple might be, sure, but then again they also might not be. What I do know is that there are a number of laws requiring compliance with customer data, and that Apple has a very clearly defined public law enforcement process for extracting much the same data off of passcode-locked iPhones as the mechanisms I’ve discussed do. In this context, what I deem backdoors (which Apple claims are for their own use), attack points, and so on become – yes suspicious – but more importantly abuse-prone, and can and have been used by government agencies to acquire data from devices that they otherwise wouldn’t be able to access with forensics software. As this deals with our private data, this should all be very open to public scrutiny – but some of these mechanisms had never been disclosed by Apple until after my talk.

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Apple Confirms “Backdoors”; Downplays Their Severity

Apple responded to allegations of hidden services running on iOS devices with this knowledge base article. In it, they outlined three of the big services that I outlined in my talk. So again, Apple has, in a traditional sense, admitted to having backdoors on the device specifically for their own use.

A backdoor simply means that it’s an undisclosed mechanism that bypasses some of the front end security to make access easier for whoever it was designed for (OWASP has a great presentation on backdoors, where they are defined like this). It’s an engineering term, not a Hollywood term. In the case of file relay (the biggest undisclosed service I’ve been barking about), backup encryption is being bypassed, as well as basic file system and sandbox permissions, and a separate interface is there to simply copy a number of different classes of files off the device upon request; something that iTunes (and end users) never even touch. In other words, this is completely separate from the normal interfaces on the device that end users talk to through iTunes or even Xcode. Some of the data Apple can get is data the user can’t even get off the device, such as the user’s photo album that’s synced from a desktop, screenshots of the user’s activity, geolocation data, and other privileged personal information that the device even protects from its own users from accessing. This weakens privacy by completely bypassing the end user backup encryption that consumers rely on to protect their data, and also gives the customer a false sense of security, believing their personal data is going to be encrypted if it ever comes off the device.

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Apple Responds

In a response from Apple PR to journalists about my HOPE/X talk, it looks like Apple might have inadvertently admitted that, in the most widely accepted sense of the word, they do indeed have backdoors in iOS, however claim that the purpose is for “diagnostics” and “enterprise”.

IMG_0205

The problem with this is that these services dish out data (and bypass backup encryption) regardless of whether or not “Send Diagnostic Data to Apple” is turned on or off, and whether or not the device is managed by an enterprise policy of any kind. So if these services were intended for such purposes, you’d think they’d only work if the device was managed/supervised or if the user had enabled diagnostic mode. Unfortunately this isn’t the case and there is no way to disable these mechanisms. As a result, every single device has these features enabled and there’s no way to turn them off, nor are users prompted for consent to send this kind of personal data off the device.

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Slides from my HOPE/X Talk

Identifying Backdoors, Attack Points, and Surveillance Mechanisms in iOS Devices

In addition to the slides, you may be interested in the journal paper published in the International Journal of Digital Forensics and Incident Response. Please note: they charge a small fee for all copies of their journal papers; I don’t actually make anything off of that, but it does support the journal. I’ve had to TEMPORARILY MOVE MY PDF because it was getting nailed with requests. My apologies.

Mirror: https://pentest.com/ios_backdoors_attack_points_surveillance_mechanisms.pdf

DON’T PANIC

Before the journalists blow this way out of proportion, this was a talk I gave to a room full of hackers explaining that while we were sleeping, this is how some features in iOS have evolved over the PAST FEW YEARS, and of course a number of companies have taken advantage of some of the capabilities. I have NOT accused Apple of working with NSA, however I suspect (based on released documents) that some of these services MAY have been used by NSA to collect data on potential targets. I am not suggesting some grand conspiracy; there are, however, some services running in iOS that shouldn’t be there, that were intentionally added by Apple as part of the firmware, and that bypass backup encryption while copying more of your personal data than ever should come off the phone for the average consumer. I think at the very least, this warrants an explanation and disclosure to the some 600 million customers out there running iOS devices. At the same time, this is NOT a zero day and NOT some widespread security emergency. My paranoia level is tweaked, but not going crazy. My hope is that Apple will correct the problem. Nothing less, nothing more. I want these services off my phone. They don’t belong there.

With that said, enjoy the slides and the paper; I think it’s solid academic quality research.

My Talk at HOPE X

I’ll be speaking at the HOPE (Hackers on Planet Earth) big X conference this year, July 18-20 in NYC. Below is a summary of my talk. It’s based on this published journal paper. Hope to see you there!

Identifying Back Doors, Attack Points, and Surveillance Mechanisms in iOS Devices

The iOS operating system has long been a subject of interest among the forensics and law enforcement communities. With a large base of interest among consumers, it has become the target of many hackers and criminals alike, with many celebrity thefts of data raising awareness of personal privacy. Recent revelations exposed the use (or abuse) of operating system features in the surveillance of targeted individuals by the NSA, of whom some subjects appear to be American citizens. This talk identifies the most probable techniques that were used, based on the descriptions provided by the media, as well as today’s possible techniques that could be exploited in the future, based on what may be back doors, bypass switches, general weaknesses, or surveillance mechanisms intended for enterprise use in current release versions of iOS. More importantly, several services and mechanisms will be identified that can be abused by a government agency or malicious party to extract intelligence on a subject, including services that may, in fact, be back doors introduced by the manufacturer. A number of techniques will also be examined in order to harden the operating system against attempted espionage, including counter-forensics techniques.
Speakers: Jonathan Zdziarski

TrueCrypt.org May be Compromised

Today, a new version of TrueCrypt (7.2) was pushed to SourceForge, and the TrueCrypt.org website was replaced with an incredibly suspicious page recommending users cease all use of TrueCrypt and use tools such as Bitlocker. The TrueCrypt maintainers have not officially (as of the time of this writing) commented yet on whether the site is compromised, or whether they are (more unlikely) scuttling the project for reasons unknown.

There have been a number of conspiracy theories ranging from a warrant canary (someone tipping off the TrueCrypt team that a secret warrant was issued for information about them) to a massive website compromise, and finally to a terribly sloppy and unprofessional true exit from TrueCrypt.

My take? I don’t know, but most agree it is very suspicious that the TrueCrypt team would lead anyone to use private, proprietary software like BitLocker, when there are plenty of FOSS implementations out there that work well. Usually when someone is lying under duress (or even trolling), one natural way to tip everyone else off to that fact is to state something completely unbelievable that other people would see is completely unbelievable. The TC team recommending BitLocker fits that bill, and I think leaves a hint to the public to disregard everything they’re saying about TC. The whole thing smells suspicious, and at the very least, should be approached with caution.

One thing is for certain: You should not download or trust anything from TrueCrypt until this is all sorted out. That doesn’t mean, however, that you should stop using TrueCrypt if you already are.

Here are a few steps on what you should do, however, to protect your content:

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Journal Paper Published

The International Journal of Digital Forensics and Incident Response has formally accepted and published my paper titled Identifying Back Doors, Attack Points, and Surveillance Mechanisms in iOS Devices. This paper is a compendium of services and mechanisms used by many law enforcement agencies and in open source, of modern forensic techniques to create a forensic copy of personal data from iOS devices. It also covers existing mechanisms designed for enterprises, such as fingerprint and PIN bypasses, which could potentially be misappropriated for surveillance of a target, if provided with the right technical capabilities.

Note: I don’t make any money off of this paper; the journal itself charges for copies of all of its papers, but unless they haven’t told me something, the author doesn’t make any commission. I wrote this strictly for the endeavor of science and knowledge.

Thoughts on iMessage Integrity

Recently, Quarkslab exposed design flaws[1] in Apple’s iMessage protocol demonstrating that Apple does, despite its vehement denial, have the technical capability to intercept private iMessage traffic if they so desired, or were coerced to under a court order. The iMessage protocol is touted to use end-to-end encryption, however Quarkslab revealed in their research that the asymmetric keys generated to perform this encryption are exchanged through key directory servers centrally managed by Apple, which allow for substitute keys to be injected to allow eavesdropping to be performed. Similarly, the group revealed that certificate pinning, a very common and easy-to-implement certificate chain security mechanism, was not implemented in iMessage, potentially allowing malicious parties to perform MiTM attacks against iMessage in the same fashion. While the Quarkslab demonstration required physical access to the device in order to load a managed configuration, a MiTM is also theoretically possible by any party capable of either forging, or ordering the forgery of a certificate through one of the many certificate authorities built into the iOS TrustStore, either through a compromised certificate authority, or by court order. A number of such abuses have recently plagued the industry, and made national news[2, 3, 4].

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Fingerprint Reader / PIN Bypass for Enterprises Built Into iOS 7

With iOS 7 and the new 5s come a few new security mechanisms, including a snazzy fingerprint reader and a built-in “trust” mechanism to help prevent juice jacking. Most people aren’t aware, however, that with so much new consumer security also come new bypasses in order to give enterprises access to corporate devices. These are in your phone’s firmware, whether it’s company owned or not, and their security mechanisms are likely also within the reach of others, such as government agencies or malicious hackers. One particular bypass appears to bypass both the passcode lock screen as well as the fingerprint locking mechanism, to grant enterprises access to their devices while locked. But at what cost to the overall security of consumer devices?

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How Juice Jacking Works, and Why It’s a Threat

How ironic that only a week or two after writing an article about pair locking,  we would see this talk coming out of Black Hat 2013, demonstrating how juice jacking can be used to install malicious software. The talk is getting a lot of buzz with the media, but many security guys like myself are scratching our heads wondering why this is being considered “new” news. Granted, I can only make statements based on the abstract of the talk, but all signs seem to point to this as a regurgitation of the same type of juice jacking talks we saw at DefCon two years ago. Nevertheless, juice jacking is not only technically possible, but has been performed in the wild for a few years now. I have my own juice jacking rig, which I use for security research, and I have also retrofitted my iPad Mini with a custom forensics toolkit, capable of performing a number of similar attacks against iOS devices. Juice jacking may not be anything new, but it is definitely a serious consideration for potential high profile targets, as well as for those serious about data privacy.

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iOS Counter Forensics: Encrypting SMS and Other Crypto-Hardening

As I explained in a recent blog post, your iOS device isn’t as encrypted as you think. In fact, nearly everything except for your email database and keychain can (and often is) recovered by Apple under subpoena (your device is either sent to or flown to Cupertino, and a copy of its hard drive contents are provided to law enforcement). Depending on your device model, a number of existing forensic imaging tools can also be used to scrape data off of your device, some of which are pirated in the wild. Lastly, a number of jailbreak and hacking tools, and private exploits can get access to your device even if it is protected with a passcode or a PIN. The only thing protecting your data on the device is the tiny sliver of encryption that is applied to your email database and keychain. This encryption (unlike the encryption used on the rest of the file system) makes use of your PIN or passphrase to encrypt the data in such a way that it is not accessible until you first enter it upon a reboot. Because nearly every working forensics or hacking tool for iOS 6 requires a reboot in order to hijack the phone, your email database file and keychain are “reasonably” secure using this better form of encryption.

While I’ve made remarks in the past that Apple should incorporate a complex boot passphrase into their iOS full disk encryption, like they do with File Vault, it’s fallen on deaf ears, and we will just have to wait for Apple to add real security into their products. It’s also beyond me why Apple decided that your email was the only information a consumer should find “valuable” enough to encrypt. Well, since Apple doesn’t have your security in mind, I do… and I’ve put together something you can do to protect the remaining files on your device. This technique will let you turn on the same type of encryption used on your email index for other files on the device. The bad news is that you have to jailbreak your phone to do it, which reduces the overall security of the device. The good news is that the trade-off might be worth it. When you jailbreak, not only can unsigned code run on the device, but App Store applications running inside the sandbox will have access to much more personal data they previously didn’t have access to, due to certain sandbox patches that are required in order to make the jailbreak work. This makes me feel uneasy, given the amount of spyware that’s already been found in the App Store… so you’ll need to be careful what you install if you’re going to jailbreak. The upside is that , by protecting other files on your device with Data-Protection encryption, forensic recovery will be highly unlikely without knowledge of (or brute forcing) your passphrase. Files protected this way are married to your passphrase, and so even with physical possession of your device, it’s unlikely they’d be recoverable.

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Introduction to iOS Binary Patching (Part 1)

Part of my job as a forensic scientist is to hack applications. When working some high profile cases, it’s not always that simple to extract data right off of the file system; this is especially true if the data is encrypted or obfuscated in some way. In such cases, it’s sometimes easier to clone the file system of a device and perform what some would call “forensic hacking”; there are often many flaws within an application that can be exploited to convince the application to unroll its own data. We also perform a number of red-team pen-tests for financial/banking, government, and other customers working with sensitive data, where we (under contract) attack the application (and sometimes the servers) in an attempt to test the system’s overall security. More often than not, we find serious vulnerabilities in the applications we test. In the time I’ve spent doing this, I’ve seen a number of applications whose encryption implementations have been riddled with holes, allowing me to attack the implementation rather than the encryption itself (which is much harder).

There are a number of different ways to manipulate an iOS application. I wrote about some of them in my last book, Hacking and Securing iOS Applications . The most popular (and expedient) method involves using tools such as Cycript or a debugger to manipulate the Objective-C runtime, which I demonstrated in my talk at Black Hat 2012 (slides). This is very easy to do, as the entire runtime funnels through only a handful of runtime C functions. It’s quite simple to hijack an application’s program flow, create your own objects, or invoke methods within an application. Often times, tinkering with the runtime is more than enough to get what you want out of an application. The worst example of security I demonstrated in my book was one application that simply decrypted and loaded all of its data with a single call to an application’s login function, [ OneSafeAppDelegate userIsLogged: ]. Manipulating the runtime will only get you so far, though. Tools like Cycript only work well at a method level. If you’re trying to override some logic inside of a method, you’ll need to resort to a debugger. Debugging an application gives you more control, but is also an interactive process; you’ll need to repeat your process every time you want to manipulate the application (or write some fancy scripts to do it). Developers are also getting a little trickier today in implementing jailbreak detection and counter-debugging techniques, meaning you’ll have to fight through some additional layers just to get into the application.

This is where binary patching comes in handy. One of the benefits to binary patching is that the changes to the application logic can be made permanent within the binary. By changing the program code itself, you’re effectively rewriting the application. It also lets you get down to a machine instruction level and manipulate registers, arguments, comparison operations, and other granular logic. Binary patching has been used historically to break applications’ anti-piracy mechanisms, but is also quite useful in the fields of forensic research as well as penetration testing. If I can find a way to patch an application to give me access to certain evidence that it wouldn’t before, then I can copy that binary back to the original device (if necessary) to extract a copy of the evidence for a case, or provide the investigator with a device that has a permanently modified version of the application they can use for a specific purpose. For our pen-testing clients, I can provide a copy of their own modified binary, accompanied by a report demonstrating how their application was compromised, and how they can strengthen the security for what will hopefully be a more solid production release.

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On Expectation of Privacy

Many governments (including our own, here in the US) would have its citizens believe that privacy is a switch (that is, you either reasonably expect it, or you don’t). This has been demonstrated in many legal tests, and abused in many circumstances ranging from spying on electronic mail, to drones in our airspace monitoring the movements of private citizens. But privacy doesn’t work like a switch – at least it shouldn’t for a country that recognizes that privacy is an inherent right. In fact, privacy, like other components to security, works in layers. While the legal system might have us believe that privacy is switched off the moment we step outside, the intent of our Constitution’s Fourth Amendment (and our basic right, with or without it hard-coded into the Constitution) suggest otherwise; in fact, the Fourth Amendment was designed in part to protect the citizen in public. If our society can be convinced that privacy is a switch, however, then a government can make the case for flipping off that switch in any circumstance they want. Because no-one can ever practice perfect security, it’s easier for a government to simply draw a line at our front door. The right to privacy in public is one that is being very quickly stripped from our society by politicians and lawyers. Our current legal process for dealing with privacy misses one core component which adds dimension to privacy, and that is scope. Scope of privacy is present in many forms of logic that we naturally express as humans. Everything from computer programs to our natural technique for conveying third grade secrets (by cupping our hands over our mouth) demonstrates that we have a natural expectation of scope in privacy.

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Your iOS device isn’t as encrypted as you think

This should help clear up the common misconception that data is encrypted and secured in iOS. While it’s true that iOS does sport an encrypted file system, that file system is virtually always unlocked from the moment the operating system boots up, as the OS (and your applications) need access to it. Even when the device is locked with your PIN or passphrase, the encrypted file system is readable to the operating system – what this means is that your data is NOT encrypted using an encryption that depends on your password – at least for the most part. Apple adds a second layer of encryption on top of this file system called Data-Protection. Apple’s Data-Protection encryption has the ability to protect a file while the device is locked by encrypting it with a key that is only available when you’ve entered your PIN or passphrase. While a PIN can be brute forced, a passphrase is much stronger.

So what’s the problem? Well, as of even the latest versions of iOS, the only files protected with this secondary encryption is your mail index, the keychain itself, and third party application files specifically tagged (by the developer) as protected with Data-Protection. Virtually everything else (your contacts, SMS, spotlight cache, photos, and so on) remain unprotected. To demonstrate this, I’ve put together a small recipe you can run on your own jailbroken device to bypass the lock screen. You can then use the GUI to browse through all of the data on the device, without ever providing your PIN. The only thing you’ll not be able to access are the files I’ve just mentioned. This lock screen bypass isn’t really a vulnerability in and of itself; it’s just one of many ways I can demonstrate to you that you don’t need a passphrase to view a vast majority if the data on your phone.

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