DarthNull.org - David Schuetz Rambles about Stuff on Darth Null

About

Tue, 01 Apr 2014 02:09:18 -0400

… me

Hi. I’m David. I’m a security geek. Mostly. Well, that’s my job, anyway. In real life, I like to program, goof around with network stuff, watch movies, and other typical geek-like activities. Though I also have three kids, so really what I like most is making them laugh. Which is good, ‘cause that’s about all I have time for. Especially since my biggest extra-curricular activity for the last 4 or 5 years has been supporting Scouting America.

Job Hunt!

Mon, 01 Jan 0001 00:00:00 +0000

Publications

Mon, 01 Jan 0001 00:00:00 +0000

Somehow, calling this “Publications” feels a little pretentious, but I really wasn’t sure what else to use. Basically, I wanted to be sure there was a good way to share slides from the talks I’ve given, or papers I’ve written, etc.

I know I’ve had people ask me after a talk for copies of the slides, and I know there are many who I’ve forgotten to get in touch with later. For that, I apologize. This way, I can just say “It’ll be on my website later today.”

Topics

Mon, 01 Jan 0001 00:00:00 +0000

Here I should have a short list or index of the tags used. Ideally, this would be automatically generated based on all the topics currently being used. Or maybe just the top ten.

For now, here’s just a list of the top 5, in roughly decreasing order of how much I’ve babbled about each topic.

Lists

Lists of items on the site, mostly about references (but could include posts), and generally more about the “kind” of document than about content. For now, I just have a few lists:

Projects

Mon, 01 Jan 0001 00:00:00 +0000

Like any geek, I’ve got about a dozen things happening at once. Some of my bigger projects include:

KhanFu

In 2009, I got my first iPhone (a hand-me-down 1st generaton phone from my little brother, in fact). Three weeks later, I was heading to DEF CON, and I thought, I can put the DEF CON schedule on my phone! I built some simple HTML pages, using the iUI Framework, stuck them on my web server, and set it out there for people to use.

Dark Mode, and other site improvements

Wed, 23 Apr 2025 16:12:51 -0400

I’ve been listening to the Accidental Tech Podcast for years. They recently had a members-only special about the technology they use for their personal websites. Building customized, Rube Goldberg-esque systems for managing a website is a time-honored time sink for many, myself included. And since an earlier version of this site used a system developed by one of the podcast’s hosts (and inspired its look and feel), I was looking forward to the episode.

Latest news on Spotlight Knowledge Events

Fri, 18 Apr 2025 10:02:50 -0400

This is a quick update. Yes. I know I say that a lot (or at least, I certainly think it when I start a post). This one really will be quick.

First, background. My main computer, a 2018 Intel Mac Mini, has been having its internal drive fill up. Regularly. To the point that apps crash without warning overnight, backups fail, Mail stops working, etc. In February, I traced the main source of the problem to a folder called SpotlightKnowledgeEvents (I’m just gonna say SKE most of the time.) At the time, this folder had over 37 gigabytes of data in it.

Word Salad - Slicing and Dicing with awk and sort

Fri, 11 Apr 2025 09:39:45 -0400

A few days ago, as I write this, Kelly Guimont posted the following question:

Let’s say you have a data set made up of a selection of songs by one artist. Let’s also say you want to slice and dice information from said dataset like how many songs come from each album, or average song length.

As of now what I want to know is the easiest way to “ask” my data set for this information. Do I have to type everything in a spreadsheet and filter? Can I use this to learn a teeny bit of python or something?

Managing Sequoia Disk Space

Tue, 11 Mar 2025 18:02:00 -0400

Disk Usage Woes: Day…whatever. How long has it been since I installed macOS Sequoia?

I’ve been struggling with the disk constantly filling up on my Mac Mini. See my last two posts for a deep and wonky dive into the situation, and lots of data collection to confirm my suspicions (or not).

At this point, I’m still continuing to collect data, but it’s more in the realm of “just making more graphs for reference” than actually figuring anything out. I think the fix is pretty clear at this point: I need to delete extraneous data from time to time. I just now have a better idea where to find the best low-hanging fruit for deletion.

Update on Spotlight and Disk Space Woes

Thu, 27 Feb 2025 16:45:00 -0500

My main day-to-day machine is a 2018 Mac Mini. Over the last year, and especially the last 6 months, it’s been a struggle to keep adequate space free. About two weeks ago, I’d had enough, and went on a deep dive to figure out what was wrong. In my last post, I described the journey I took to identify the likely problem.

Simply identifying a “likely” culprit wasn’t enough, though. I needed to take a methodical approach to testing different settings and recording the results.

macOS Sequoia Disk Space...Vanishing!

Wed, 19 Feb 2025 17:36:38 -0500

My everyday desktop is a 2018 Mac Mini. Last summer, I started noticing that some apps would crash overnight, mostly Ivory (my Mastodon client).

I assumed it was a memory thing. My disk space wasn’t great, but I had like 5 gigabytes or so free on the 256 gig drive, and wasn’t seeing any “your disk is full” errors. I wasn’t getting crazy “Your system is out of memory!” errors, either, but memory pressure seemed like a good explanation. I tried a few lazy tricks to get some data, try to collect logs, etc., but got nowhere.

Replacing my Synology DS1515+

Tue, 28 Jan 2025 17:25:00 -0500

Nine years ago, I migrated all my local house storage from a massive Dell with Debian and software RAID, onto a tiny little Synology NAS. Well, not exactly tiny, but probably 1/3 of the volume of the Dell. It serves as a file server, Time Machine target, and destination for various rsync and other low-level backup tasks from the rest of the network. At other times, it’s run a Plex server, the Channels DVR, and…I honestly don’t remember what else I’ve experimented with here. It’s a pretty capable little box.

Update on August Ping Storms

Tue, 01 Oct 2024 13:44:14 -0400

A few days ago, I wrote about what GreyNoise have been calling “Noise Storms,” extended periods of high-volume ping traffic detected by many of their sensors, coming from…many different sources. The most intriguing of these were packets with the word “LOVE” in plaintext in the ping payload, and in my post, I offered a possible explanation of that traffic. At least, at a technical level – what they’re doing with those packets, well, that’s a different puzzle.

Ping Storms at GreyNoise

Fri, 27 Sep 2024 09:22:42 -0400

Earlier this month, I attended BSidesNoVA in Arlington, where the keynote was presented by Andrew Morris of GreyNoise. Using sensors distributed all over the world, GreyNoise collects…background noise…on the Internet. Basically, they watch and monitor activity that hits lots of hosts randomly – network mapping, port scanning, doorknob rattling. If you see someone trying to break into your SSH server, you can check GreyNoise to see if that person (well, their IP, anyway) has been seen doing such things in the past.

Funemployment, and Next Steps

Tue, 09 Jul 2024 19:16:26 -0400

Back in 2018, I was fortunate enough to join a company called Expel. It had a great culture, friendly management with a real desire to do what’s right for customers and employees, and a product that seemed to fill a real need – and to fill it well.

Being remote friendly even in 2018, we were ready when the pandemic hit, and it seemed like we made it out the other side unscathed. But then we hit some snags, and in June 2023, I got laid off, along with 10% of my co-workers.

Using an Adafruit NeoTrellis Keypad with MQTT

Mon, 26 Apr 2021 10:45:00 -0400

I’ve been building a light-up keypad for home automation devices (and Zoom sessions). Last time, I gave an overview of the project. This entry will detail the hardware itself, completing a basic remote-only setup, while the next post adds more advanced features and connects it to a server. You can browse the entire series from the link in the header, or by clicking here.

Building a remote-control home automation keypad

Sun, 25 Apr 2021 16:20:00 -0400

I use Zoom. A lot. Obviously, a whole lot more since we all started working from home. It’s not a big deal – I’ve gotten pretty used to it, and it’s a good system. So much better than the PictureTel VTCs I occasionally used in the early 90’s.

What’s annoying, though, is when someone asks a question and I’m on mute. Suddenly, there’s a scramble to figure out which monitor the mouse pointer is on…jiggle…jiggle…JIGGLE! Oh, there it is. Now, where’s the window? Over – no, wrong way. Over here. Hover. Up comes the control bar. Down to the left and click – shoot, missed. Hover again. Okay, NOW mute is off.

Codenames Board Generator

Thu, 11 Mar 2021 10:35:50 -0500

Codenames is a word game where players try to collect all of their team’s cards from a board, by having their Spymaster give one-word hints which describe one or more cards on the table. Which cards belong to which team is determined by a random draw of pre-printed game maps, showing which positions belong to Red, which to Blue, and which is the Assassin card (the black card – revealing this ends the game for both teams).

1Password - Full Trip from Unlock to Encryption

Mon, 12 Nov 2018 16:20:00 -0500

It occurred to me sometime after I’d finished my talk that I should have a single post that pulls all the elements together. So here’s a complete walkthrough from Master Password all the way to decrypted Vault Item.

If you’ve missed the first parts of the series, here’s a good starting point.

General Process

First, let’s review the overall sequence of events. It’s a little complicated at the beginning, depending on which client we’re using.

BSidesDE - A deep dive into 1Password Security

Fri, 09 Nov 2018 07:10:00 -0500

Thanks to BSides Delaware for the chance to go super-geeky about how 1Password works. Here are the slides from my talk, which give a basic introduction to how it all works. See this extended series for super-detailed technical information and examples.

Click on the link above to download a copy of the slides.

1Password - Wrapping up with a few quick topics

Fri, 09 Nov 2018 07:05:00 -0500

Thanks for reading! I hope you’ve enjoyed this deep dive into how 1Password works.

We’ve covered a lot:

Why I even went down this path
Unlocking macOS clients and the 2SKD process
Unlocking Windows clients
Decrypting data in the cloud-based vault system
Unlocking and decrypting local vaults

But there’s actually quite a bit I haven’t touched upon.

Password Strength

One thing I totally skipped over was the strength of the master password. There are actually several different password derivation steps in use by 1Password, all using PBKDF2:

1Password - Local Vaults

Fri, 09 Nov 2018 07:04:00 -0500

To conclude (for now) this extensive look at 1Password, we’ll go back a little to see how local private vaults work. Initially, local vaults were all you had (though they could be synced over Dropbox and other methods). These are documented separately from the cloud based “Teams” system. Now, local vaults are basically being discouraged in favor of the cloud system.

But you can still have a mix of local and loud vaults. So it’s worth seeing how those affect the way data is stored in 1Password.

1Password - Into the Vaults!

Fri, 09 Nov 2018 07:03:00 -0500

We’re back with part three of a close look at how 1Password works. So far we’ve seen how the Two-Secret Key Derivation (2SKD) process is used to unlock macOS clients, and how the Encrypted Master Key (EMK) does the same under Windows. In both cases, we end up with a decrypted master key, the “sym key” in the account’s first keyset. As I’ve said in both prior segments, this key then lets us descend into the vault and decrypt everything else.

1Password - Unlocking Windows Clients

Fri, 09 Nov 2018 07:02:00 -0500

I’m taking a detailed look at how 1Password works, originally to help examine potential risks when used in a corporate environment, and eventually because I’m just a nerd and love All Things Crypto. (See this page for an introduction and background).

Last time, I explained how the 1Password Two-Secret Key Derivation Process (2SKD) works. Briefly, it takes your email address, master password, and secret key, along with a couple other parameters, and derives a strong Master Unlock Key or MUK.

1Password - MUKing about on the Mac

Fri, 09 Nov 2018 07:01:00 -0500

We’ll start out by looking into how you unlock the client on macOS.

Introduction – Using 1Password on macOS

Let’s say you’ve been a long-time 1Password user. You have a couple of local vaults that sync over Dropbox between your Mac and iPhone. Then you open a Family account, and share a few vaults with your spouse. And then you join a company that uses 1Password internally, and now you’ve suddenly got three accounts – local, family, and work.

How 1Password Works - Getting under the hood

Fri, 09 Nov 2018 07:00:00 -0500

Earlier this year, I embarked on a deep dive into how 1Password works. In particular, I wanted to understand what could happen if an attacker managed to collect a user’s Master Password – how hard would it then be to get all their passwords?

As part of this quest, I’ve explored the 1Password vault structure, read their security white papers, asked for help from engineers in their support forum, and written multiple tools to Read All The Passwords.

Encrypting for Apple's Secure Enclave

Thu, 31 May 2018 08:30:00 -0400

Encryption, once you have a safe and well-implemented algorithm, is all about the keys. Lose control of your keys, and it’s “Game over, man!” What if we could put our keys somewhere completely out of reach, where even their owner can’t get to them? Yibikeys and HSMs can provide that security, but they’re external devices. However, recent iOS devices and MacBook Pros have something just as good: the Secure Enclave (SE).

Infosec Conference Badge Display

Tue, 17 Oct 2017 12:17:00 -0400

My first infosec con was the first ShmooCon, in 2005. Then I went to Black Hat and DEFCON. Then ShmooCon again. Then Vegas again. And before long, I had a whole lot of badges cluttering up drawers.

Probably a code violation. (Circuit breakers are behind these doors).

In 2010 I won, as part of the ShmooCon crypto contest, a stuffed moose head for the wall (“But not a real moose head, that’s cruel 🎶”). So I started hanging the badges from that, and it followed me from office to office for a while. By the time I moved into a home office, I had far too many badges to hang from the moose and so I moved them to nails on top of my circuit breaker doors. Which is probably a violation of several building and safety codes. So back in May of 2014, I decided to correct the situation.

Technology Sucks

Tue, 12 Sep 2017 07:15:00 -0400

Technology today is flat-out amazing. When I was a kid, walking uphill through the snow to get to school, cordless phones were massive (and amplitude modulated near the broadcast band), and video recorders had wired remotes. If you could quantify it, I’d venture that today’s capabilities are 3 or 4 orders of magnitude above what we had 30 years ago.

And at some point, almost without exception, I’ve hated every piece of technology I own.

Eclipse.

Thu, 24 Aug 2017 23:02:00 -0400

Scene: February, 1979. My fifth grade classroom. A large-for-the-time 17" or so black-and-white TV (the kind with a faint greenish tinge) sits on a cart. Everyone watching a total solar eclipse happening live in the Pacific Northwest. I don’t remember the mood in the room, but I suspect it was a mix of breathless, half-bored, and “meh.” I do remember, very clearly, learning that the next one was in 2017 and thinking how far away that seemed. And yet, resolving to see it.

iPhone Secure Enclave Firmware Key Found

Thu, 17 Aug 2017 23:20:00 -0400

Earlier today, it was reported that a hacker/researcher called “xerub” had released the encryption key, and tools to use it, for the firmware that runs the Secure Enclave Processor (SEP) on iPhone 5S. Reporting was…breathless. Stories suggested that this move was “destroying key piece of iOS mobile security,” and that we should “be on the lookout for Touch ID hacks” and “password harvesting scams.”

Is it really that bad? No, not really.

New Website Engine

Mon, 07 Aug 2017 21:16:00 -0400

A few years back, I moved from a fairly generic Wordpress-based blog to a statically-generated system based on secondcrack. It was a fairly simple system, that I immediately hacked up to add different post types, lists, and other taxonomy-like things. And I pretty much stole the look and feel of the primary site secondcrack was built for.

It worked out pretty well, overall, but I did notice at times that it was a little too bare-bones. Especially difficult was navigating past a really long post at the top of the page, to get to something shorter and totally different buried beneath it.

New Standing Desk

Thu, 03 Aug 2017 14:17:00 -0400

A few months ago, I set up my computer on a counter-level table in the home theater for a few days, to see what I thought of the idea of a standing desk. I liked it, but definitely didn’t want to be standing all the time. I needed something adjustable.

Then a couple months later, The Wirecutter posted a review of standing desks, and their top pick was the Fully Jarvis Bamboo desk. Unfortunately, that was a little too small for the large collection (2 monitors plus the laptop screen, plus various other stuff) I had on my IKEA Gallant corner desk. However, they sell an L-shaped version, the Jarvis J3. And it’s available as just the frame, so I can even keep my desktop.

ShmooCon 2017 Badge (and more) Contest - Solutions

Fri, 20 Jan 2017 10:24:36 -0500

Shall We Play A Game?

It’s been a long time since I did a big puzzle solution post, and even longer since I played a crypto contest at ShmooCon. That’s about to change. :)

After winning three years in a row, and running the ShmooCon contest for four years after that, I finally stepped away from the fray in 2016. But I did help out a little, commenting on the puzzles they were putting together and generally offering advice. This year, though, about 2 weeks before ShmooCon started, it dawned on me: I haven’t heard a single thing about the contest. I CAN PLAY!

ShmooCon 2017 Badge (and more) Contest - Challenges

Fri, 20 Jan 2017 10:16:21 -0500

Belay It

1: Total Control

Look Around

* pictures on con signs outside rooms *

2: Pseudo-random

/oneyamasoon

go to /oneymasoon, see text "Setec Astronomy".

3: Stonecutter

4: Scrapple

5: Who you gonna call?

whoyougonnacall.mp3

6: Boring Compound

114.81832.065231.03588140.11610215.9994
20.179740.07814.00674.00260239.948
88.9058515.9994238.028911.0079422739.0983

7: (Data, Points)

8: Screentest

(link to “loom”, which presented this ASCII image:)

  /--------------------------------------------------------------------------------
 / ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░
/  ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░
|  00000000000000000000000000000000000000000000000000000000000000000000000000000000
|  11111111111111111111111111111111111111111111111111111111111111111111111111111111
|  22222222222222222222222222222222222222222222222222222222222222222222222222222222
|  33333333333333333333333333333333333333333333333333333333333333333333333333333333
|  44444444444444444444444444444444444444444444444444444444444444444444444444444444
|  55555555555555555555555555555555555555555555555555555555555555555555555555555555
|  66666666666666666666666666666666666666666666666666666666666666666666666666666666
|  77777777777777777777777777777777777777777777777777777777777777777777777777777777
|  88888888888888888888888888888888888888888888888888888888888888888888888888888888
|  99999999999999999999999999999999999999999999999999999999999999999999999999999999

Also relevant was the result from solving #7:

BSidesROC - A (not so quick) Primer on iOS Encryption

Sat, 23 Apr 2016 01:35:10 -0400

Thanks so much to BSides Rochester for giving me a chance to talk about iOS encryption. I was happy to see such a good audience with plenty of very good questions. We discussed how the overall iOS encryption system works, how passcodes are used to secure it, and what attacks, limitations, and weaknesses still remain.

Click here or on the post title to download a copy of the slides.

Poem Codes - WWII Crypto Techniques

Sun, 27 Mar 2016 09:41:02 -0400

Introduction

A few years back, after I won my first crypto contest, the contest author, G. Mark Hardy, suggested I read Between Silk and Cyanide. Written by Leo Marks, it’s a first-person account of the difficulties managing cryptographic communications with field agents in Europe during World War II.

Much of the story centered on the “poem codes” used by the agents, but the technical details were kind of obscure and not clearly explained. So I thought I’d do my best to document how I think it worked. This probably isn’t the exact method they used, but hopefully it’ll be close enough that you can get the general idea, and understand some of the difficulties these agents faced.

Put away the tin-foil: The Apple unlock case is complicated enough

Fri, 19 Feb 2016 09:10:20 -0500

Apple and the FBI are fighting. The {twitter, blog, media}-‘verses have exploded. And FUD, confusion, and conspiracy theories have been given free reign.

Rather than going into deep technical detail, or pontificating over the moral, legal, and ethical issues at hand, I thought it may be useful to discuss some of the more persistent misinformation and misunderstandings I’ve seen over the last few days.

Background

On February 16, 2016, Apple posted A Message to Our Customers, a public response to a recent court order, in which the FBI demands that Apple take steps to help them break the passcode on an iPhone 5C used by one of the terrorists in the San Bernardino shooting last year.

Mobile App Authentication using TouchID and Tidas

Wed, 10 Feb 2016 10:50:19 -0500

Yesterday, the information security company Trail of Bits announced a new service, called Tidas. The service is intended to make it easy for developers to include a password-free authentication experience in mobile apps on the iOS platform. They’ve provided some sample code and a developer Guide / FAQ, and I’ve spent some time looking at it to try and understand how it works. Here are my first impressions.

NOTE: I haven’t actually looked at the full protocol running “in the wild” yet, so it’s quite possible I haven’t fully grokked the system. Take this with a grain of salt. I’ll try to update any egregious misunderstandings, as I become aware of them.

Blizzard of 2016 Time-lapse

Fri, 22 Jan 2016 02:30:45 -0500

For the last several years, we’ve tried to keep a big “snow stick” out on our deck to capture images of big snowfalls. In particular, the winter of 2009-2010 was exceptional for this, with no fewer than 3 very large storms in our area (including the crazy storm which happened at ShmooCon 2010). That storm dumped nearly 30" over two days at Dulles Airport, just a few miles away from our house.

ShmooCon - My Hash Is My Passport: Understanding Web and Mobile Authentication

Sun, 17 Jan 2016 01:04:42 -0500

I just finished presenting this at ShmooCon, and wanted to get the slides out quickly before it got shoved aside by the next crisis. :) I’ll replace this with a blog entry that’s actually useful later.

The short version is this:

I do a lot of application testing, for web and iOS / mobile apps
Many (most?) of those apps rely on some kind of authentcation to a back-end server
How that authentication is handled seems to be generally restricted to a handful of systems
It seemed to me that being able to understand how those systems work is important to being able to fully test such applications
So this talk explains how the systems work, what’s good, and bad, and why
There’s also a whitepaper (in final draft) that goes into even more detail and has extensive references. I’ll post that here as well when it’s released.

Here’s the abstract from the conference, which says all I just said but in fancier words:

DLP Considered Harmful - A Rant about Reliable Certificate Pinning

Tue, 24 Nov 2015 12:34:33 -0500

[Note: Yes, I understand the point of DLP. Yes, I’m being unrealistically idealistic. I still think this is wrong, and that we do ourselves a disservice to pretend otherwise.]

The Latest Craziness

It is happening again. A major computer manufacturer (this time, Dell, instead of Lenovo) shipped with a trusted root TLS CA certificate installed on the operating system. Again, the private key was included with the certificate. So now, anyone who wants to perform a man-in-the-middle attack against users of those devices can easily do so.

Thoughts on CyberUL and Infosec Research

Wed, 29 Jul 2015 11:05:14 -0400

For the past year or so, I’ve been thinking about the information security research space. Certainly, with the mega-proliferation of security conferences, research is Getting Done. But is it the right kind of research? And is it of the right quality?

This has recently become a hot topic, since .mudge tweeted on June 29:

Goodbye Google ATAP, it was a blast.

The White House asked if I would kindly create a #CyberUL, so here goes!

Salt as a Service: Interesting approach to hashing passwords

Tue, 21 Apr 2015 10:26:32 -0400

A new service was just announced at the RSA conference that takes an interesting approach to hashing passwords. Called “Blind Hashing,” from TapLink, the technology is fully buzzword-compliant, promising to “completely secure your passwords against offline attack.” Pretty grandiose claims, but from I’ve been able to see in their patent so far, it seems like it has some promise. With a few caveats.

Traditionally, passwords are hashed and stored in place. First we had the the Unix cyrpt() function, which, though it was specifically designed to be “slow” on systems at the time, is now hopelessly outdated and should be killed with fire at every opportunity. That gave way to unsalted MD5-based hashes (also a candidate for immediate incendiary measures), salted SHA hashes, and today’s state of the art functions bcrypt, scrypt, and PBKDF2. The common goal throughout this progression of algorithms has been to make the hashing function expensive, in either CPU time or memory requirements (or both), thus making a brute force attack to guess a user’s password prohibitive.

Nails in the Crypt - White Paper

Fri, 06 Mar 2015 10:28:30 -0500

A bit of a hack I did in 2010, tweaking some rainbow table tools to work with old-school UNIX password hashes. Includes very rough code samples.

Lenovo, CA Certs, and Trust

Fri, 20 Feb 2015 03:27:05 -0500

It’s been a fun week for information security:

@yawnbox - A Bad Week

Arguably one of the more interesting developments (aside from the SIM thing, which I’m not even going to touch) was the decision by Lenovo to pwn all of their customers with a TLS Man-In-The-Middle attack. The problem here was two-fold: That Lenovo was deliberately snooping on their customer’s traffic (even “benignly,” as I’m sure they’re claiming), and that the method used was trivial to put to malicious use.

ShmooCon - Knock Knock: A Survey of iOS Authentication Methods

Fri, 23 Jan 2015 08:45:55 -0500

Introduction

Last Saturday, I gave a talk at ShmooCon detailing the results of a short survey of iOS applications, and the way they handled (and secured) network-based authentication. For a quick summary of my talk, read on. If you’d like to follow along with the slides, they can be downloaded here. If you’d like a very detailed white paper explaining everything I said in the talk and more, well, you’ll have to wait a little longer. But I’m working on it.

DerbyCon 2013 - Apple TV and Raspberry Pi Slides

Tue, 18 Nov 2014 12:30:43 -0500

Slides from my DerbyCon 2013 talk about building a car media center on Raspberry Pi, and how to make that appear as a native application on Apple TV.

Unfortunately, the method I outlined here was blocked days later by Apple. Current Apple TV development requires specific configuration profiles signed by Apple.

Bypassing the lockout delay on iOS devices

Tue, 18 Nov 2014 04:13:27 -0500

Apple released iOS 8.1.1 yesterday, and with it, a small flurry of bugs were patched (including, predictably, most (all?) of the bugs used in the Pangu jailbreak). One bug fix in particular caught my eye:

Lock Screen

Available for: iPhone 4s and later, iPod touch (5th generation) and later, iPad 2 and later

Impact: An attacker in possession of a device may exceed the maximum number of failed passcode attempts

Why I hate voting.

Tue, 04 Nov 2014 08:49:00 -0500

I just voted, even though pundits and statisticians have proven fairly definitively that my particular vote won’t matter. My district has had a Republican congressman for 30 years and his hand-picked heir is likely to win, and I don’t live in one of the 6 states all the news organizations tell me will decide control of the Senate. I voted because it’s the right thing to do, and because if I don’t vote, I lose the moral right to complain about the idiots in power (and anyone who knows me knows I love to complain.)

What's the deal with keyless entry car thefts?

Tue, 28 Oct 2014 10:49:54 -0400

In June of 2013, a few videos started circulating showing people unlocking cars without authorization. Basically, people walking directly up to a car and just opening it, or walking by cars on the street. One of the more interesting videos (watch at about 30 seconds in) showed a thief walking along the street, grabbing a handle in passing, and stopping short when the car unlocked. (interestingly, all the videos I found this morning showed attackers reaching for the passenger side door, which may just be a coincidence…)

MCX - a lousy substitute for proven technology

Mon, 27 Oct 2014 11:00:02 -0400

Lots of discussion the last few days about Rite Aid and CVS (and possibly other merchants) actually disabling existing NFC point of sale functionality simply because they were suddenly getting used (by Apple Pay).

NFC payments are nothing new – Android has supported them for a couple years now (on select phones, though not without some complicated political shenanigans between manufacturers and carriers). Not a lot of places support such contactless payments, though I’ve certainly been seeing more and more POS terminals with NFC-looking logos lately. And I’ve seen a LOT of new POS terminals going in recently (at Panera and Target, in particular) which definitely support the upcoming EMV (“Chip and PIN”) cards, and I believe also support NFC.

iPhone SMS forwarding -- cool, but may be risky

Fri, 24 Oct 2014 06:02:46 -0400

The recent release of iOS 8 brought with it several cool new features, especially some which more tightly integrate the iOS world with the OS X desktop world. Some of these are limited by physical proximity (like handing off email drafts among devices), while others are require being on the same local subnet (forwarding phone calls to the desktop).

However, one feature apparently Just Works all the time, and that’s SMS message forwarding. If you have an iPhone, running iOS 8, then you can send and receive normal text messages (to your “Green bubble friends”) from your iPad or Yosemite desktop. Even if the phone is the next town over.

Rebutting FUD and privacy issues surrounding Yosemite Spotlight

Tue, 21 Oct 2014 09:37:22 -0400

Recent reports (and a slew of tweets) have circulated about the new Spotlight search on OS X Yosemite. Rene Ritchie at iMore explains the concerns, facts, and back-and-forth of the situation pretty well.

Especially damning was this lede from The Washington Post:

Apple has begun automatically collecting the locations of users and the queries they type when searching for files with the newest Mac operating system, a function that has provoked backlash for a company that portrays itself as a leader on privacy.

NoVA Hackers - iOS Cryptography Slides

Tue, 14 Oct 2014 09:40:04 -0400

I’m lucky to live near a really good information security group, NoVA Hackers. We meet once a month, and usually have 6-10 speakers of all levels, speaking on just about anything they’d like.

I thought this might be an audience who’d be interested in learning how the recent iOS security changes actually worked, and so threw together a quick talk based mostly on my blog post of a week before.

It was well received, and I had a lot of really good questions during and after the talk. One question I didn’t have the answer for at the time was:

Even more posts about iOS encryption

Wed, 08 Oct 2014 09:18:41 -0400

The assertion recently made by Apple that “it’s not technically feasible” to decrypt phones for law enforcement has really stirred up several pots.

Many in law enforcement are upset that Apple is “unilaterally” removing a key tool in their investigations (whether that tool has ever been truly “key” is another debate). Some privacy experts hail it as a great step forward. Others say “it’s about time.” And still others debate whether it’s quite as absolute a change as Apple’s making it sound.

A (not so) quick primer on iOS encryption

Mon, 06 Oct 2014 10:57:51 -0400

A few weeks ago, Apple published a message about Apple’s commitment to your privacy. In the section on Government Information Requests, Apple made the following somewhat startling statement:

On devices running iOS 8, your personal data such as photos, messages (including attachments), email, contacts, call history, iTunes content, notes, and reminders is placed under the protection of your passcode. Unlike our competitors, Apple cannot bypass your passcode and therefore cannot access this data. So it’s not technically feasible for us to respond to government warrants for the extraction of this data from devices in their possession running iOS 8.

Beacons being deployed in NYC phone booths

Mon, 06 Oct 2014 01:17:48 -0400

A story hit the press this morning about a comapny installing Bluetooth beacons (in the iOS world, known as “iBeacons”) on phone booths in New York City. The fear is that these could be used to track users and send unwanted advertisments to their phones.

This article on Forbes does a pretty good job of explaining the situation, far better than the lengthy blog post I tried to write this morning (one really long post from me in a day is probably more than enough).

Internet of SCADA, or, why does my HVAC blow?

Fri, 05 Sep 2014 01:21:22 -0400

We live in a house that was new-built, so it’s got all the modern trimmings. It’s also got all the modern cut corners, including an air conditioning system (two, actually) that even 12 years later we’re still struggling with. It seems that every year or two something else goes wrong, especially with the combined cooling / heat pump unit that handles the upstairs.

I’ve been thinking for a while that I should be able to build a temperature monitor to track how the system is running, to detect problems (loss of freon, etc.) early, and maybe even forestall costly repairs. Maybe. So I asked for some Arduino gear for Christmas, and earlier this summer, I finally started playing around with it.

Praetorian Crypto Challenge

Mon, 25 Aug 2014 09:34:48 -0400

Last Wednesday, the security company Praetorian released a new set of crypto challenges as a recruitment tool and fun challenge for the community.

I sprinted through the first 5 (of 8) levels in less than 24 hours, then got totally stuck on Level 6 for over two days. Finally, late Saturday night I managed the intuitive leap I was missing, and by early Sunday morning I’d finished level 6. Some hours later (after, you know, sleeping) I finished level 7, and level 8 fell in under 15 minutes, making me the first person to solve all 8 levels. (No prizes, but I enjoy the bragging rights, and, well, the pressure makes sure I actually try to finish them all….) Congratulations also to @TheJEversmann for “coming in a close second.”

Stealing user events from foreground apps on Android

Fri, 22 Aug 2014 10:14:11 -0400

This is a pretty scary attack, though I haven’t had the time to dig into the paper to see how widespread it may be (and my Android background probably isn’t deep enough to grasp all the implications). However, the demos are impressive.

Briefly, the attackers load an unprivileged application, which requests network access and nothing more. That application then exploits weaknesses in the operating system to collect data on the state of the user interface, from which they are able to actually extract sensitive information.

BSidesLV 2014 Badge Contest

Sun, 10 Aug 2014 01:49:30 -0400

BSidesLV 2014 Badge

I was in Las Vegas for another Security Summer Camp, and for the past 5 years a major part of that has been Security BSides, or BSidesLV. I checked in and only barely got a badge, as they had just run out (but while I was standing there looking sad, someone stepped up with an extra…crisis averted!)

It didn’t take long for me to notice a faint QR code on the back of the badge, but I didn’t bother to read where it led at this point. I hung out for a while, watched an interesting talk on PRNGs, and went back to my room at Black Hat to unwind after a long travel day.

BSidesLV 2014 Badge Contest - Challenges

Sun, 10 Aug 2014 01:44:36 -0400

Crack It

Easy Peasy (10 points)

MD5 7ea04a3b047bc6364839c2dd34eccbb7

Such Admin, Very Weak (20 points)

admin:$6$DwjR36pA$QskuzZ/K.4gF.mFmP2At3/QOC5I061AScmWzoqtGsyuLoKVx1j4DMY6esuoKjWDBimes9Qy1x4nBC/MTdeOrV/:16287:0:99999:7:::

LAme MAN…. (30 points)

LM F6853114CCD860A7823031F4926E4DEE

NyanNyan! (40 points)

NTLM E6E813370ACB92129BDA449EE25E0FA4

Don’t Eat That! (50 points)

Crack this admin's password:01c1fe5112f563e030f6aba0f51be085

Decipher It

Not Quite, Julius (10 points)

GSGHRRGUBUO
Clue: 0123456789....

WOPR With Cheese (20 points)

Something seems to be off with the WOPR today.

Knock Three Times If You’re There (30 points)

Uld0V1ExSkZTVlpXUkUwd1RWSlNSQT09

Under The Door (40 points)

Discovered this hidden message under my door....

BSLV 2014 - Breaking PRNGs

Wed, 06 Aug 2014 12:11:58 -0400

So I’m back in Las Vegas for another Hacker Summer Camp. After getting to town, checking in at Mandaly, and getting to BSidesLV, I hung out for a while and then decided I should check out a talk.

I didn’t have too much time that I could spend here, as I had to get back to BH for some volunteer duties, but I really was curious about the Mersenne Twister talk by Moloch and Dan Petro.

Duo Security Bypasses PayPal 2FA for Mobile Apps

Wed, 25 Jun 2014 10:52:31 -0400

A nice writeup and demonstration video from Duo Sec showing some problems with PayPal two-factor authentication.

We developed a proof-of-concept exploit to leverage this lack of 2FA enforcement, interfacing with the PayPal API directly and effectively mimicking the PayPal mobile app as though it were accessing a non-2FA account. The exploit communicates with two separate PayPal API services — one to authenticate (only with primary credentials), and another to transfer money to a destination account.

Early look at iOS 8 configuration profile changes

Wed, 18 Jun 2014 09:59:58 -0400

It seems Apple has made the prerelease Configuration Profile Key Reference available to the public. This the technical documentation for much of the iOS and Mac enterprise management capabilities Apple makes available via MDM vendors, Configurator, etc. (The other main document, the MDM Protocol Reference, remains behind the developer site authentication wall.)

Most of what we think of as “part of MDM” is really just the configuration settings that MDM can push out. This reference (expanded last year to include OS X) includes all the publicly known settings that can be configured via a profile. These profiles can then be installed on a device via USB, HTTP, or MDM.

More Mobile Malware Melodrama

Tue, 17 Jun 2014 01:46:11 -0400

A few days ago I commented on the iOS malware situation. One might sum it up as “fanboys smugly assert there is no iOS malware; anti-fanboys smugly point to this list as proof that the fanboys are idiots.”

Then not three days later, American Banker posted an article about Svpeng, an existing trojan that’s been making the rounds in Russia and is now hitting US users.

What I found most interesting about that article is this: Not once do they mention the platforms affected by the malware. Hell, even the Kaspersky press release is coy about it, only using the word “Android” once, and that in their formal name for the trojan (Trojan-Banker.AndroidOS.Svpeng.a). This trojan seems to have been out for almost a year, but now that it’s hitting US users, Kaspersky is putting on a full-court press in the…er…press… (I should really steer clear of sports analogies). Predictably, I’ve had customers anxiously asking about the trojan, and whether they or their customers should be concerned.

iOS Malware - Still FUDish, not quite a Real Problem (yet)

Tue, 10 Jun 2014 10:30:23 -0400

A short blog post is making the rounds on Twitter this morning, aiming to burst the myth that “malware for iOS doesn’t exist.”

With our FortiGuard Labs reporting that 96.5% of all mobile malware is Android based it would be easy to see why someone might opt for an iPhone. But, users beware. Don’t write off iOS as the secure alternative to Android just yet! Despite, Android malware being nearly an epidemic, or as Tim Cook referenced, “a toxic hellstew”, iOS is not immune.

Memory Pressure, Capacity Limits, and Ubiquitous Computing

Mon, 02 Jun 2014 09:51:54 -0400

One of the things I was most looking forward to with my new iPhone 5S was faster switching between applications. It seemed like my 4S always took 5-10 seconds to toggle between two programs, even simple apps. Jumping from Angry Birds to YouTube (to see what I’m doing wrong) and back again was agonizing.

Unfortunately, though the 5S is significantly faster, switching has in some ways become worse. The slowest reloads are faster, but I feel like I need full reloads more frequently. I’m convinced this is simply due to memory usage. Many applications (especially those with lots of full retina artwork) are taking the device to its RAM limits. No amount of new processor power can mask the fact that there’s just not enough memory in the device.

Making Tunnelblick + Google Authenticator Easier to Use

Fri, 30 May 2014 02:29:43 -0400

I’ve been occasionally using a VPN that requires a Google Authenticator code to connect. I say “occasionally” because it’s a pain to use – I have to launch Tunnelblick (the VPN client I’m using on my Mac), then get the VPN password out of my password manager and paste it in, then open my phone, launch Google Authenticator, and enter the displayed tokencode next to my password.

It’s not horrible – but it’s awkward enough that I find myself looking for ways to avoid using this particular connection. Then the other day, a co-worker suggested using a script to dump the credentials into the VPN config on the fly and re-launch. And so, my lunchtime project was decided for me.

Apple ID Compromise and Device Lockout

Tue, 27 May 2014 08:41:57 -0400

I’m seeing quite a few stories this morning (really, it started yesterday afternoon) about iOS users in Australia getting their devices locked out with a $100 ransom message.

It’s unclear at this point exactly how this is happening, but it seems evident that the affected users are having their Apple IDs hacked. Typically, such hacks involve things like weak passwords falling to brute force attacks by a botnet or falling for a phishing attack. That doesn’t really explain the fact that all the affected users appear to be located in Australia, however. Perhaps the most likely possibility is that an Australian e-mail provider has been hacked, giving hackers the ability to reset the password of weakly-protected Apple IDs associated with those e-mail addresses. Regardless of how it’s happening, though, those Apple IDs are being compromised.

iOS Backups are Still Broken

Mon, 19 May 2014 06:46:55 -0400

A quick take on some of the many issues backing up large, complicated iOS configurations to iCloud backup.

Apple needs to make some hefty changes to iCloud. It needs to allow you to backup and take advantage of the full size of your iPad (128GB max) inexpensively. In my case, since most of my data is strung between four cloud services (OneDrive, Dropbox, Google Drive, and iCloud), I didn’t need to back it all up. However, for a while I used iBooks to store my side-loaded ePubs and PDFs. In this case, I had to stop backing it up to iCloud because of space concerns. Loosing all of those in the case of a system failure led me to put my PDFs back on Dropbox and use Goodreader to access them. Being able to keep them all in iCloud (about 50g of data) would be very nice.

How much of your email goes through Google?

Mon, 12 May 2014 09:05:10 -0400

Nice bit of data (and a link to a script) that shows roughly how much of this person’s email ended up on a Google server at some point.

For almost 15 years, I have run my own email server which I use for all of my non-work correspondence. I do so to keep autonomy, control, and privacy over my email and so that no big company has copies of all of my personal email.

Inadvertent OS X Mail Loading of Images in SPAM

Thu, 08 May 2014 01:03:44 -0400

I just noticed an interesting bug. I got a SPAM email (which I fortunately get far fewer of today because of SpamHero). As I usually do when a SPAM leaks through, I forwarded it to SpamHero so they can use it to improve their filters.

Less than a minute after forwarding the email, I received another copy of virtually the same SPAM. Dutifully, I forwarded it again, but this time I noticed something strange: Though the Mail application identified the email as SPAM (and thus refused to load embedded images), the email as incorporated into the forwarding message window did load the images.

Dark Reading on the VZ DBIR puzzle

Tue, 06 May 2014 10:11:52 -0400

I haven’t yet written up this year’s DBIR puzzle, so here’s an article at Dark Reading that neatly summarizes it.

Verizon’s earlier contests were mainly cryptography challenges with blocks of cipher that contestants had to decrypt. But the contest has evolved over the years from a crypto focus to more of a mind-bending puzzler. “It’s less about someone being an expert in cryptography as it is for someone who is really good at troubleshooting and solving problems… and being really good at puzzles,” says Mark Spitler, co-author of the Verizon DBIR and the mastermind behind the cover challenge contest.

Referrer considered harmful: Leaking location of obscurely shared docs

Tue, 06 May 2014 01:14:57 -0400

Ha. From the “Shoulda seen this one coming” department: Sharing a file with another person (via Dropbox, Box, or any other hosting service) may not be as private as you think. Sure, you may have a completely random URL that nobody else will be able to predict. And, sure, you may rightfully trust the people with whom you share the link not to reveal it to anyone else. But if the file you’ve shared contains a link to a 3rd party site, watch out!

Apple ID Madness

Sun, 04 May 2014 12:58:04 -0400

One of the reasons I was so excited to get an iPhone a few years back was because of contact management. For years (from 1997 until about 2010) I carried around a Palm Pilot, which had reasonably good tools to synchronize data between the mobile device and my computer. Then I got a “modern” cell phone, which could do text messaging and everything, and setting up data syncing with that was….nearly impossible. But the iPhone, well, most of the time it works just fine.

It's time to (re)start.

Fri, 02 May 2014 04:16:18 -0400

Wow, I haven’t posted here in nearly a year. For a while last year, I was experimenting with a second blog where I could post quick little blurbs, links to interesting current events, but that never really took hold. I think part of it was it was just too much of a pain to post the little things. Plus, I don’t know, somehow I just got busy or somehting last summer.

BSidesROC 2014 - Crypto Puzzle

Sat, 05 Apr 2014 04:15:00 -0400

Walkthrough of my BSidesROC14 crypto puzzle.

Not delivered in person – slides sent to BSidesROC and Jason (presumably) presented them during closing ceremonies.

Sanitize your outputs: Apple ID Password Logfile Disclosure

Mon, 10 Mar 2014 03:23:00 -0400

In recent weeks, there have been quite a few security disclosures for Apple. Some of these have even been pretty significant. Not to pile on, but here’s some detail behind another security issue that I stumbled across last fall.

Apple had just restricted the availability of the Add Site feature on Apple TVs, and I was trying to determine whether alternate methods existed to enable the feature. If you couldn’t install the required configuration profile directly, maybe it’d work via MDM? Nope, that didn’t work. Wait, what about the Touch Setup feature? That’s obviously allowed to make changes to the Apple TV system.

CVE-2014-1279 - Password Disclosure via Apple TV Touch Setup

Mon, 10 Mar 2014 01:00:00 -0400

Intrepidus Group Security Advisory

http://www.intrepidusgroup.com

Title:              Apple TV Touch Setup Wi-Fi and iTunes Password Disclosure
Release Date:       10 March 2014
Discoverer:         David Schuetz <david.schuetz@intrepidusgroup.com>
Vendor:             Apple
Vendor Reference:   http://support.apple.com/kb/HT1222
CVE Reference:      CVE-2014-1279
Systems Affected:   Apple TV (3rd generation) running ATV 6.0 - 6.0.2 
Risk:               Medium
Status:             Published

Timeline

Discovered: 10 October 2013
Reported: 8 November 2013
Fixed: 10 March 2014
Published: 10 March 2014

Summary

The release of Apple TV version 6.0, based on iOS 7.0, introduced a new convenience feature for the setup of new Apple TV units, colloquially referred to as “Touch Setup.”

More Fun with Apple TV Hacking (and Manual RSA Signature Validation)

Fri, 21 Feb 2014 08:59:00 -0500

In my last post, I showed how the latest Apple TV system checks for an Apple-signed certificate before allowing changes to certain device settings. In particular, this prevents easily enabling the “Add Site” application, detailed in my 2013 DerbyCon talk. However, as I mentioned in the last post, it’s possible to load the profile on an Apple TV running 5.2 or 5.3, and then upgrade to 6.0, and retain access to Add Site. The problem then is that the system won’t actually permit adding any sites. What gives?

Apple TV Hacking, Counterattacks, and Certificate Pinning

Tue, 11 Feb 2014 04:03:00 -0500

A few months ago I presented a neat hack at DerbyCon that let you put your own apps on Apple TV. A few days afterwards, the hack stopped working. It’s time I had a follow-up to explain just what happened (and hopefully teach a little about certificate pinning in the process).

First, a quick review: The Apple TV OS has a feature called “Add Site,” through which a developer can add a pointer to a custom application, which will then appear on the Apple TV’s home screen. To enable this feature, a special configuration profile needs to be loaded. The fun part of my talk was showing how one could find exactly what’s needed to make this profile, through some simple disassembly of the Apple TV binary.

ShmooCon 2014 - Crypto Puzzle Slides

Sun, 19 Jan 2014 03:00:00 -0500

ShmooCon X Crypto Puzzle Contest - wrap-up slides from closing ceremonies.

Good fun with bad crypto

Wed, 15 Jan 2014 11:04:00 -0500

A few months back, one of the consultants here at Intrepidus ran across a strange password hash format:

OLEOIECBPAFFKGADMDGGLBBEMIGNIPCKOAEFIPCKOLEO

He did some digging, and eventually found an application which would not only create the hashes, it would decrypt them. So it’s not even a hash at all, just a really lousy encryption system. Well, not even encryption. Technically, it’s an encoding. “Citrix CTX1 Encoding”, to be exact. “How does this work?” I wondered. Unfortunately, the person who created the app we downloaded specifically declined to explain the algorithm, so we just moved on.

Raspberry Pi Media Center on AppleTV - No Jailbreak Required

Sun, 29 Sep 2013 04:04:00 -0400

A few months ago, I started looking into using a Raspberry Pi (I’m gonna call it rPI from now on) as an access point / media server for the car. It started off as a way to let my boys play Minecraft with each other during long car trips….and then kind of went a little over the top after that.

RPI in Car

In June, an interesting AppleTV hack called PlexConnect got some press, and I started thinking about trying to get videos from the rPI onto an AppleTV.

iStupid: the indescreet SSID tool

Wed, 19 Jun 2013 02:03:00 -0400

Sometimes, the names of past Wi-Fi networks your iOS device has used get broadcast to the world as the device tries to find someone to talk to, and this can (possibly) leak information about your favorite home or work networks. So it’s a good idea to delete these networks whenever you’re done using them. Unfortunately, here’s no way to remove Wi-Fi networks from the “Preferred Network List” (PNL) on iOS, unless you happen to be in range of that network at the time. Then, and only then, do you get the option to “Forget this Network.”

Hijacking accounts using unicode magic

Tue, 18 Jun 2013 01:57:00 -0400

A nice writeup on how canonical forms can cause problems when using extended UNICODE alphabets.

Not so good since the function apparently was not idempotent, but at least it provided insight into why the attack worked. When you registered an account ‘ᴮᴵᴳᴮᴵᴿᴰ’, canonical_username got applied once, and an account with canonical username ‘BIGBIRD’ got registered which was allowed since it did not collide with the existing account with canonical username ‘bigbird’. When resetting the password for ‘ᴮᴵᴳᴮᴵᴿᴰ’ canonical_username was applied once, so the email to send the password reset to got sent to the address associated with the newly created account with canonical username ‘BIGBIRD’. However, when the link was used, canonical_username was once again applied, yielding ‘bigbird’ so that the new password was instead set for the ‘bigbird’ account. We were relying on nodeprep.prepare being idempotent, and it wasn’t.

Apple's security strategy: make it invisible

Fri, 14 Jun 2013 12:18:00 -0400

Interesting piece from Rich Mogull about Apple and how the user interacts with security.

Apple is famously focused on design and human experience as their top guiding principles. When it comes to security, that focus created a conundrum. Security is all about placing obstacles in the way of attackers, but (despite the claims of security vendors) those same obstacles can get in the way of users, too.

[…]

While Apple hasn’t said so explicitly, it’s clear that one key principle guides them when it comes to security: The more you impede a user’s ability to do something, the more likely that user is to circumvent security measures.

A chameleon for your streams

Thu, 13 Jun 2013 08:21:00 -0400

This is awesome. A project to encrypt your data, and then reformat it to “look like” other data, like HTTP. Then deep packet inspection can’t recognize that it’s something else…like covert communication sneaking past the eyes of an oppressive regime…or, well, data being exfiltrated from a compromised corporate network.

More generally, we’re optimistic FTE has long-term potential as a tool to enable users to control how their traffic is classified by passive DPI systems. As one example, over the last month, we’ve successfully tunneled Tor through the Great Firewall of China, using FTE to make our traffic “look like” HTTP.

iOS 7 and Mavericks: New feature roundup from a security perspective – Intrepidus Group - Insight

Tue, 11 Jun 2013 10:47:00 -0400

A quick link to a piece I posted on the Intrepidus Group blog. Lots of cool features coming in iOS 7, and many of them will probably have “interesting” security implications.

iOS 7 and Mavericks: New feature roundup from a security perspective

Tue, 11 Jun 2013 10:46:00 -0400

Yesterday Apple unveiled the latest versions of OS X (code-named Mavericks) and iOS 7, at the annual World Wide Developer Conference (WWDC). The general focus was on end-user features and items of interest to developers, but several items appeared to have an impact on security in one way or another.

The beta versions of both operating systems were also released to developers yesterday, but I haven’t seen them yet (and once I do, I’d probably be bound by NDA to not talk much about them). So before I go that route (hopefully later this week!), I thought it would be useful to quickly review some of the items I found potentially significant. I’ll briefly describe the features, then summarize some of the security questions I have at the end. Also, whenever I talk about “Early Reports,” I’m referring to information not specifically announced by Apple, but which have leaked through screenshots and other reports.

Android Security Overview

Wed, 05 Jun 2013 11:12:00 -0400

I haven’t seen this before (being primarily focused on iOS), but this looks like a pretty good parallel to the Apple iOS Security whitepaper published last year.

Skout server leaked nearly-exact location information on users

Fri, 31 May 2013 11:32:00 -0400

Another scary privacy find from Aldo Cortesi:

The Skout mobile application talks to Skout’s servers through a simple API.

What’s returned is a blob of XML containing the user’s complete profile data. In fact, the profile data is too complete, including some bits of data information that is never actually used by the app. For example, we can see the user’s exact date of birth… but only the user’s age in years is actually displayed. Most serious, however, is the high-precision location information that is returned in the homeLocation and location tags.

Auto-updating iOS apps

Wed, 22 May 2013 10:06:00 -0400

Sen. McCain asked why we have to “keep updating apps” all the time:

McCain does have a point. It’s really annoying to pop open the App Store every time there’s a new update. We wish iPhones worked more like Android phones in that respect, letting you update apps automatically.

But is that really a good idea? I know there have been several times in the past year where an upgrade to an app broke things, and needed a subsequent “emergency” fix from the developer.

Two-factor authentication for Twitter: One account at a time

Wed, 22 May 2013 03:41:00 -0400

Just announced:

This is a form of two-factor authentication — when you sign in to twitter.com, there’s a second check to make sure it’s really you. After you enroll in login verification, you’ll be asked to enter a six-digit code that we send to your phone via SMS each time you sign in to twitter.com.

This is great, and has been an increasingly frequent request over the past couple of years. However, there’s one drawback: You can only use your phone number with one account.

Google Hangouts and XMPP

Fri, 17 May 2013 09:46:00 -0400

The announcement of the improved Google Hangouts the other day worried many of us who use Google Talk (through third-party clients like Adium). Were they completely killing Jabber/XMPP? I tested some this morning, and found that I can chat between Hangouts and Adium. Then I found this article, which explains in a little more detail what’s going on:

There’s some bad news that comes with the new Hangout architecture, at least for others who want to have interoperability with Google chat users on the server side via XMPP. Google will not allow server-to-server connections. Chee Chew said that “we haven’t seen significant uptake” in federation with Google Talk via server-to-server connections. The majority of the uptake Google did see was from organizations or individuals looking to bombard Google Talk users with chat spam, Chew said. As a result, server-to-server XMPP has been left out of the consolidated Hangout environment.

Recovering iPhone Restrictions Passcode

Thu, 16 May 2013 12:07:00 -0400

Interesting find.

Look for the file called com.apple.springboard.plist and open it in Property List Editor.

The file should have a key titled SBParentalControlsPin and the Value for this item is exactly what we were looking for. Our missing 4 digit Restrictions Passcode.

To carry off this hack, you need to be using unencrypted backups of the device (otherwise, you won’t be able to read the file). Or, naturally, it’s very easy if you have a jailbroken device.

Social Share Privacy

Thu, 16 May 2013 10:14:00 -0400

A nice way to take back some control over unintential browser history leakage:

More and more websites use like-buttons from Facebook, Google+ and Twitter. However, these buttons send information to these social networks even if the user doesn’t click them, but even if they are just present on a webpage. This way these networks are able to track which websites users are visiting and are able to build fairly complete browser histories of their users. Because this is neither what a user might expect nor what many website operators that embed like-buttons want, this alternative way of using these social services was developed.

How To Safely Store A Password

Thu, 16 May 2013 01:42:00 -0400

This is a few years old, but worth reposting, as the question comes up regularly (like it did a couple minutes ago in my Twitter stream). The goal, it reminds us, is to pick an algorithm that’s “slow as hell”:

So we’re talking about 5 or so orders of magnitude. Instead of cracking a password every 40 seconds, I’d be cracking them every 12 years or so.

Note also that scrypt and PBKDF2 are generally recognized as valid substitutes, as the basic logic of this post still applies to those algorithms.

Apple, Forensics, Law Enforcement, and FUD

Mon, 13 May 2013 10:32:00 -0400

Just like the perennial discussion on location-based services and Apple’s ability to track you, the question of accessing an iOS device’s data when the device is locked seems to come up every few months. This time around, the discussion was inspired by a CNET article, with the sensational title “Apple deluged by police demands to decrypt iPhones.”

The article seemed to be built around a single paragraph in a blurry copy of a search warrant affidavit from ATF, which stated that the writer “contacted Apple” and was told by “an employee […] who is part of their Apple Litigation Group” that Apple “has the capabilities to bypass the security software” on the iPhone.

iSniff your Wi-Fi and GPS your House

Fri, 10 May 2013 09:52:00 -0400

It’s been a while since I thought much about location-based services on iOS systems, in particular their privacy implications. Of course Locationgate happened back in March 2011, when researchers called public attention to a database of location points saved on iPhones. A year later, Mark Wuergler reported on a possible information leak where iOS devices disclosed the MAC addresses (more properly, BSSIDs) of the last few access points they’d linked to.

These two issues were brought together last summer, at the Black Hat Arsenal, when Hubert Seiwert (@hubert3) presented a tool called iSniff GPS. The tool was described in more detail at Syscan in Singapore just a couple of weeks ago, but finally came to my attention in a tweet Wednesday night pointing me to SC Magazine (Australia).

iSniff your WiFi - Archived Comments

Fri, 10 May 2013 01:02:00 -0400

hubert3

May 10, 2013 at 1:02 pm

Thanks for the writeup.

The ARPs which sometimes contain the BSSID information disclosure are actually targeting the MAC address of the DHCP server on a previously joined network. On most home/soho WiFi routers, the DHCP server MAC address is the same as the router’s WiFi BSSID (sometimes it’s the same except for the last octet).

This is often not the case on bigger corporate WiFi networks with multiple APs and separate DHCP servers, so the MAC address picked up may sometimes not be a WiFi BSSID at all and can’t be used for geolocation.

DBIR Cover Challenge 2013

Mon, 29 Apr 2013 12:46:00 -0400

It’s time for the 2013 edition of the Verizon Data Breach Investigation Report Cover Challenge! This year I didn’t win…but only just barely. It also felt like a bit of a different puzzle this year, not quite as much a series of challenges as just a scavenger hunt with only the barest minimum of breadcrumbs scattered to help us follow the path to victory.

With that in mind, I’ll focus less on the individual puzzle elements, and more on the challenge experience.

2013 DBIR Puzzle - Archived Comments

Mon, 29 Apr 2013 10:18:00 -0400

Ari E-B

April 29, 2013 at 10:18 pm

Some friends and I were also doing the puzzle and made it as far as the book cipher but didn’t recognize what it was. I also followed up on a few more dead end leads you might find interesting:

The good colonel appears to have a login for a dead website here: http://www.bugmenot.com/view/flinside.com – I don’t know if this was seeded by Verizon or if someone else decided to poison the well. flinside is a domain squatter, so I assumed he had used that password elsewhere (like the godaddy page) and tried using that. I also tried operating under the assumption that flinside was a typo and tried to figure out what else it could have meant.
I took the phone number from the cofthem.ca whois info and tried to track that down. Calling the number turned up a VZ employee who apparently worked on the puzzle, and I did spend some time cyber stalking him thinking it was part of the puzzle till I realized I had accidentally drifted across the line from “puzzle” to “real life” and backed off.
The address of cofthem.ca is a museum in Quebec. I spent time trying to find anything interesting there too.

Anyway, I enjoyed myself. Thanks for posting the solution so I can see the last step we missed.

iOS Configuration Profile Ransomware

Thu, 11 Apr 2013 11:40:00 -0400

A couple of months ago, at ShmooCon 2013, Tim Medin gave a great short talk titled “Apple iOS Certificate Tomfoolery.” One of the most interesting ideas I took away from this talk was the idea of ransomware delivered through a configuration profile. Briefly, configuration profiles can be used to control many aspects of an iOS device’s configruation. They can enable features, disable features, and even hide applications from the user.

This is the tricky bit: Create a configuration profile that disables Safari, disables installation of applications, even disables iCloud backups, and adds a “READ ME” web page to the user’s home screen. Put a password on the profile, so the user has to enter the password in order to remove it. Now, you just need to convince the user to install the profile, and you can do that simply through email or SMS phishing. Once they install it, half their expected functionality suddenly goes away, and if they tap on the “READ ME” page, they’ll see the instructions as to how to pay ransom to receive the password to remove the profile. Win! (well, not for the user).

ShmooCon 2013 - Crypto Puzzle Slides

Sun, 17 Feb 2013 03:15:00 -0500

The closing ceremonies presentation for the 2013 ShmooCon 9 crypto puzzle.

Getting ready for ShmooCon

Tue, 12 Feb 2013 01:20:00 -0500

It’s almost time for another ShmooCon, and as usual, we’ll be out in force for the conference. We won’t have a booth this year, but we will be milling about, attending talks, and even giving a couple presentations of our own. We might even have a little puzzle to share…just ask any one of us for details. (David might have a slightly more visible puzzle contest as well, but, well, there were secrecy oaths, threats of retribution, etc., so the less said about that, the better).

Evading evasi0n: iOS 6 Jailbreak Prevention

Tue, 05 Feb 2013 04:06:00 -0500

The latest iOS jailbreak was released yesterday. Called “evasi0n” it can be used to bypass most all protections in iOS 6.1 on any device that supports it. It’s quite cool, and was certainly something I was looking forward to (since much of my work is greatly aided by working on a jailbroken device).

However, another part of my work is ensuring that our customers’ devices are as secure as they can be. And having an available jailbreak kind of weakens those assurances. So it might be useful to find a way to prevent the jailbreak from working.

Tracking Down the UDID Source - Archived Comments

Mon, 10 Sep 2012 12:32:00 -0400

Mek0s

September 10, 2012 at 12:32 pm

            GJ on this guys&#8217;.  Much respect.

PhishMe

September 10, 2012 at 1:11 pm

            nice work!

mattjay

September 10, 2012 at 1:24 pm

Really great to see less echo chamber finger pointing and actual research. Great job!

@zcobb

September 10, 2012 at 2:14 pm

            Nice work Mr. Schuetz! I admit that I had started to look for patterns in the names (why do so many Dawn&#8217;s own iOS devices?) but you nailed it. Congrats on some inspired analysis!

ohgoodnesswhat

September 10, 2012 at 3:03 pm

            Horsepuckey.

And how much was BlueToad paid to be the alibi?

Fidelis Decode This 2012 - Archived Comments

Mon, 10 Sep 2012 12:00:00 -0400

Nate

September 10, 2012 at 10:43 pm

That must have felt great! Congrats. Great to read how you got there.

alexcohn

September 11, 2012 at 6:17 am

Actually the Fibonacci sequence is explicit in the drawing: the sizes of squares are:

1, 1, 2, …

Tracking Down the UDID Breach Source

Mon, 10 Sep 2012 12:00:00 -0400

I’d heard about the alleged FBI/Apple UDID leak shortly after arriving at work last Tuesday morning, and immediately downloaded and began reviewing the data. Less than an hour later, I’d surmised that comparing apps across multiple devices might help narrow down the source.

Several hours later, at 3:00, I saw a tweet from @Jack_Daniel suggesting that people checking their UDIDs in online forms only enter partial numbers . And that made me wonder: “How many digits is the minimum people need to enter in order to be guaranteed a unique result?” Sort to the rescue:

What the flagnog? The Apple / FBI UDID breach, simplified.

Wed, 05 Sep 2012 12:28:00 -0400

Early Tuesday, a file was released detailing the compromise of 1,000,001 records, supposedly from an FBI laptop. Reportedly, these represented only a small portion of a much larger breach – over 12 million records. It’s further claimed that the full breach includes personal information such as mailing addresses and telephone numbers, while the published data was limited to only a few specific fields.

That’s what we’ve been told. But what do we actually know?

Winning the Decode This! puzzle at Black Hat

Fri, 17 Aug 2012 10:44:00 -0400

Last year, I had a great time trying to solve the Fidelis Security Systems’ Decode This! puzzle at Black Hat. But I wasn’t fast enough to win. This year, I resolved to not make the same mistakes. And in the end, it paid off!

Much like last year’s puzzle, this one involved a block of Unicode text (filled with all kinds of unpronouncable glyphs), and several hints posted on Twitter. I played with the puzzle off and on before I left for the con, but didn’t really attack it full-bore until I got onto the plane for Vegas.

Fidelis Security Systems' Decode This 2012

Fri, 17 Aug 2012 10:28:00 -0400

Last year, I had a great time trying to solve the Fidelis Secuirty’s Decode This! puzzle at Black Hat. But I wasn’t fast enough (and I missed a couple of things that should have been obvious). This year, I resolved to not make the same mistakes. And in the end, it paid off! I was the first to solve, and won a $1000 prize! Read on to see how I did it.

FidSecSys Decode This 2012 Ciphertext and Hints

Fri, 17 Aug 2012 10:28:00 -0400

Ciphertext:

ɳd❤ĢɮjźѨȵ⁑ј✶◾ҌЋųɤ❤™Ɱ٪ɺѨ✵⁑јȶ◾ҌԋųѤդ
✢ⱮѪźѨеɑŘ6ǾΌЋɳ❤ѤԢ❮❪ɺŨ‵ёјĶþΌȋɳѤѤ"n❪
ɺѨ✵⁑Xȶ◾Όԋs❤դĢɮjźɨ✵QŘȶþʌԋsŤd"Ѯ❪zѨ5
⁑Xж◾ʌԋsɤѤĢ❮٪źѨ5❑⁘ĶþʌċųդdТnŪɺŨȵQ⁘ж
◾ƌԋɳɤɤТŮɪѺhĵQŘ✶Ǿ➌ȋųŤɤ"ɮŪźѨ✵⁑X‶◾ƌЋ
sɤŤ✢❮ɪźh✵ёXȶǾҌԋɳŤŤТ❮ɪźɨȵ❑ɘ✶þ➌ԋɳѤd
ԢⱮɪѺŨĵőŘ6ǾʌԋųɤɤĢŮ❪źhȵёX✶þ▌ȋųդѤĢⱮѪ
ɺh‵ɑX6þΌȋsŤdТɮ❪ɺŨȵ❑јĶ◾ΌԋųդѤТɮ❪ѺѨĵ
QŘȶþΌȋsŤդ™ⱮŪɺѨȵőXȶ◾ҌԋɳɤѤ™njzhеёXȶ
þҌȋɳdѤĢŮɪѺѨеёŘ✶ǾʌԋsѤѤԢѮjźŨĵ⁑⁘ĶǾƌЋ
ɳ❤ɤ™nѪɺѨеQ⁘Ķþ➌ԋɳɤѤТnjѺɨеQ❘‶Ǿ➌ċѳ❤Ť
ĢⱮjzɨȵ❑XĶ◾Όȋѳ❤dТ❮Ūzhĵ⁑ŘĶǾƌԋѳդդТŮɪ
zŨ5⁑❘✶Ǿ▌ċųŤѤ•ɮ٪zh5ёXĶ◾ΌԋsŤŤԢɮ❪zѨ5
ёј✶Ǿ▌ċɳѤɤĢ❮ɪɺѨĵQ⁘жþҌȋѳdd"n٪Ѻhȵ⁑ј‶
Ǿʌċѳ❤ɤԢnŪzh✵❑ј6þҌԋѳdŤ•❮ɪѺѨ✵ёXĶ◾Ҍԋ
ɳ❤ɤ"❮ѪѺhеő❘6ǾΌċѳdѤ™nŪѺŨ5⁑⁘✶Ǿ➌ȋѳ❤ɤ
✢n٪ɺѨ‵⁑јȶþҌċsɤ❤™❮٪Ѻhеёɘ‶ǾҌċѳդŤ™ɮ٪
źѨе❑❘жǾΌċѳdդԢ❮ѪɺŨ‵ɑј‶◾➌ԋѳɤŤԢɮ❪zѨ✵
ɑјжþ▌ЋsdѤТ❮ѪźѨеё❘ĶþƌċųѤ❤•n٪ɺhĵɑXȶ
ǾҌԋѳŤ❤ТŮ٪źɨ✵❑⁘Ķþ➌ЋųdɤĢnjzѨе⁑⁘6◾➌ȋ
ѳѤdТnŪѺɨе⁑⁘ȶþʌȋųddԢⱮ٪ɺŨ✵ő❘ж◾▌ċɳŤd
Ģ❮jѺѨ✵ё❘Ķþ▌ċsѤѤ•Ɱ٪zŨ‵őXĶ◾▌ċɳѤɤ"ѮѪ
źɨе⁑ј6Ǿ➌ȋųŤѤĢⱮɪɺѨеőŘ✶◾ʌċųɤd"Ѯ❪ѺѨ‵
ɑŘж◾➌ԋsŤŤ"ѮjɺhȵQɘȶþҌԋsɤդ™Ɱ٪źŨ✵őјȶ
◾ƌԋɳɤdԢnɪɺѨ✵⁑Řж◾➌ԋѳ❤d"ŮŪѺɨĵ⁑Ř‶þ▌ȋ
ɳɤɤ™nѪѺɨ5⁑❘‶þ▌ȋɳŤdĢ❮ѪzŨ5ɑ❘6Ǿʌċųդɤ
•❮٪ѺŨ5ɑ⁘6Ǿ▌ԋsѤ❤ТⱮɪɺŨеɑɘ6þ▌ԋѳŤ❤"nj
źѨȵɑјĶ◾ҌċɳդѤ✢nѪźѨ✵❑⁘ȶǾҌċɳd❤™❮ɪźhȵ
Qј✶Ǿʌȋɳ❤❤™njѺɨеőјȶ◾ƌċѳѤ❤™❮٪zŨ‵ɑŘȶ
ǾʌȋsդɤТŮjɺhĵ⁑❘жǾ➌ԋѳdd•ⱮѪɺѨе❑X6ǾΌȋ
ųդ❤✢ɮŪɺɨ‵őX‶ǾƌȋųŤɤԢɮɪѺhе❑X✶◾ƌЋsդɤ
•nɪѺŨ‵őX6◾▌ЋsѤդĢn٪źѨȵɑŘж◾ƌȋɳ❤դ•Ů❪
źѨ‵ёɘ6ǾƌȋɳɤŤ™ѮŪzɨ5ёŘȶ◾▌ȋų❤dТѮŪɺɨĵ
❑ŘжǾ▌ԋųդ❤ТⱮ٪źѨĵё⁘Ķ◾ƌЋsɤ❤"ⱮjzŨ✵QX‶
◾ʌЋsdɤ http://goo.gl/E6vX7 ɑŘжþҌċ
ѳ❤dТnŪɺɨȵ⁑⁘‶◾▌ԋsѤѤ•Ɱ❪Ѻɨ5❑⁘‶◾ʌЋųŤd

Hints from twitter:

Hint #1: RFC2781 from Planet Bigend

Hint #2: Grok the last one

Hint #3: It ain’t as long as it looks

Hint #4: 73 64 64 22

Apple's iOS Security Overview

Wed, 20 Jun 2012 01:18:00 -0400

In late May, Apple quietly published a document entitled, simply, iOS Security. This short whitepaper describes several aspects of security within their iPad, iPhone, and iPod touch ecosystem, providing a high-level introduction to certain features and some fairly deep technical information for others. The stated goal is to help security-minded customers to better understand the core security features present in iOS. It’s definitely worth a read, but for now, let’s talk about some of the more interesting highlights.

Apple Using Unsalted Hashes Too?

Thu, 07 Jun 2012 02:55:00 -0400

As the LinkedIn password leak continues to occupy the time and attention of password-crackers, I thought it might be worth mentioning another high-profile site which apparently uses unsalted hashes.

Two weeks ago, I discovered that Apple sends an unsalted SHA-256 hash as part of an AppleID authentication process. I was looking at traffic from my iPad using MITM Proxy, and came across the following interesting packet:

Redacted AppleID Authentication

[Note – I changed the AppleID and password hash fields, and also blocked out the exact host and URL].

Verizon 2012 DBIR Challenge

Wed, 28 Mar 2012 10:30:00 -0400

Every year, Verizon Business publishes the Data Breach Investigations Report (DBIR). This year’s report analyzes of a cross-section of “855 incidents, 174 million compromised records” that have occurred over the past year. This was actually the eighth year they’ve produced the report, and it’s well worth the read.

For me, it was especially worth the read this year. Every year since 2009, they’ve had a little cryptography puzzle embedded in the document. In 2009, it was a very simple cipher, hidden as a string of 1s and 0s in the background of the cover. The 2010 puzzle was quite a bit different, and significantly harder. Then, last year, the cover challenge got much more complicated (and, I think, quite a bit more interesting).

2012 DBIR Puzzle - Archived Comments

Wed, 28 Mar 2012 09:28:00 -0400

G Mark Hardy

March 28, 2012 at 9:28 pm

Wow! That’s an impressive puzzle and an even more impressive solution. I always worry about putting this much complexity into a Con badge puzzle or contest, because few have the insight and the perseverence to grind it out to the end. Hey, with DEFCON 20 coming up, maybe we can up the difficulty factor a bit — especially if I can get Jeff to spring for an iPad as a prize! Well done! — G. Mark

2012 Verizon DBIR Cover Challenge

Wed, 28 Mar 2012 08:46:00 -0400

DBIR Cover

Every year, the Verizon Business Risk Team publishes a Data Breach Investigations Report (DBIR), analyzing trends and other great statistical information gathered from working hundreds of different, well, data breaches. For the past few years, the report has included a puzzle / challenge / crypto contest. I heard about the 2009 puzzle too late to play, gave up in disgust trying the 2010 puzzle, and skipped the 2011 puzzle (‘cause I was actually working another puzzle at the time). This year’s report came out a few days ago, and I immediately launched into trying to solve it. It took a few days, but I managed to not only solve the challenge, but I came in first! Of course, as I’m prone to do, for every little step I took forward I first took about three giant steps sideways (often repeated in two or three different directions.)

Verizon 2012 DBIR Sources

Wed, 28 Mar 2012 08:42:00 -0400

This puzzle featured a large quantity of information from several locations on the net. It’d be impossible to fully replicate the experience of sifting through all those locations, so I’m simply going to copy a representative sampling, along with those items that are necessary to solve the puzzle.

I’ll separate each “stage” on this page to help, maybe, make it easier for you to try and focus on each part individually, without jumping ahead to the endgame.

Quick Look at Apple Configurator

Fri, 09 Mar 2012 01:08:00 -0500

Shortly after the iPad event on Wednesday, Apple released the free [Apple Configurator](http://itunes.apple.com/us/app/apple-configurator/id434433123?mt=12">Apple Configurator) application. It’s billed as a way to “set up new devices, and install enterprise apps,” but my main interest was in learning how it might interact with Mobile Device Management. So I upgraded my iTunes to 10.6, installed the application, and started poking around.

Essentially, Configurator allows you to maintain a fleet of identical iOS devices. With it, you can re-baseline up to 30 devices simultaneously, pre-installing applications and configuration profiles at the same time as wiping it clean and updating the OS version. The application allows you to create configuration profiles directly, or you may import profiles created in the [iPhone Configuration Utility](http://www.apple.com/support/iphone/enterprise/" (IPCU). [Aside – the IPCU was also updated on Wednesday, and both that and Configurator support some new features, including the ability to disable Siri when the device is locked. Interestingly, Configurator also includes the ability to enable a “Siri Profanity Filter” and to disable Location Services, neither of which I’ve been able to find in the new IPCU.] The Configurator doesn’t include the capability to create an MDM enrollment profile, but you can import one from IPCU and it works just fine.

MDM Hacks - Archived Comments

Mon, 27 Feb 2012 08:33:00 -0500

Alexander

February 27, 2012 at 8:33 am

Hello!

My question is not about this topic.

I’ve seen in some mdm companies apps function to gps-tracking (http://www.amtelnet.com/mdm/lost-device-gps-tracking.php, http://www.amtelnet.com/mdm/lost-device-gps-track, http://www.amtelnet.com/mdm/lost-device-gps-track)>…

Is it possible to do with just mdm? Or this tracking made by some kind of ip location service?

david_schuetz

February 27, 2012 at 10:16 am

Apple’s MDM system does not provide geolocation capability. This functionality can be provided by a 3rd party vendor through use of vendor-specific programs on the device, which might be able to periodically poll for position changes and send that information back to a central location, where the MDM console could then display and make use of it.

iOS MDM: Preventing Disassociation DOS and Potemkin Devices

Wed, 22 Feb 2012 04:10:00 -0500

I was thinking a couple of weeks ago about additional vulnerabilities in iOS Mobile Device Management, and noticed a couple of problems that I had not considered before.

It may be possible for a malicious individual, whether an outside attacker or inside troublemaker, to forge fake responses to the MDM server. They could, it seems:

Send the server fake TokenUpdate commands
Send the server fake responses to real commands

In both cases, the attacker would need to know the UDID of the device they’re trying to impersonate.

Verifying a Detached S/MIME Signature in Python

Tue, 21 Feb 2012 10:33:00 -0500

I was recently experimenting some more with my iOS MDM server, and found that I needed to verify inbound signatures on the messages the clients send to the server. It took some doing, but eventually I found the right way to handle it at the command line.

I had to take the signature (in this case, provided as a base-64 string in the HTTP header), decode it, and save it to a file. Then I needed a copy of the public key for the certificate used to sign the message, and finally, I had to copy the text of the message itself to another file. Once all that was done, it was something like this:

BSides Phoenix 2012 Badge Puzzle

Sun, 19 Feb 2012 11:44:00 -0500

Sitting at home yesterday morning, watching cartoons with the kids and checking my Twitter feed, I saw a tweet from Georgia Weidman with a picture of the badge from BSides Phoenix. It looked like an awesome badge, made out of hefty chrome and with an integrated bottle opener. It also had a puzzle on it. There goes the rest of my morning….

As always, if you’d like to try to solve this yourself, then STOP now, as the rest of this post is full of spoilers. If you’d like to see just the images needed to solve the puzzle, click here: BSidesPHX 2012 Images.

BSidesPHX 2012 Images

Sun, 19 Feb 2012 11:44:00 -0500

The badge (as tweeted by Georgia Weidman):

And, later, you’ll get this image (but don’t look too closely at it until you solve the first stage):

Changes to iOS 5.0 MDM - Archived Comments

Wed, 15 Feb 2012 07:22:00 -0500

Van

February 15, 2012 at 7:22 am

Hello.

First of all thank you for your work.

Now question:

I’m trying your sample with regular apple developer program.

server - MacOS

device - iPhone4 iOS 5.0.1

1 - Create new AppID that looks like “com.apple.mgmt.COMPANY.PRODUCT_NAME” (this is not very clear from README).

2 - Intall web.py (not easy step but this is general question, not mdm related)

3 - Perform other steps from README, server address is ip-address.

ShmooCon 2008 Puzzle - Archived Comments

Fri, 10 Feb 2012 12:24:00 -0500

G Mark Hardy

February 10, 2012 at 12:24 pm

Very impressive! This is the most complex badge puzzle I’ve seen for a hacker conference. Although it took nearly four years for a solution to be published, Darth is the guy I would have bet on to do it.

(Darth — Now you can turn your attention to my business card puzzle — it’s been unsolved for the same length of time :)

ShmooCon 2008 Badge Puzzle

Sat, 04 Feb 2012 10:20:00 -0500

Badge 6

I’ve been having a great time solving puzzles at security conferences. I think the first significant puzzle I’d seen was at ShmooCon 4, in 2008, but I didn’t even try to solve that, partially because the bug hadn’t yet bitten me, and partially because I didn’t have any computer with me at the time. So now, four years later, I figured it was time to finally complete this puzzle. They gave a rough outline of the solution at the closing ceremony, but for this puzzle the challenge was less of a mystery than an implementation problem.

ShmooCon 2012 Puzzle - Archived Comments

Sat, 04 Feb 2012 06:14:00 -0500

GMark Hardy (@g_mark)

February 4, 2012 at 6:14 pm

Another fun puzzle for Shmoocon fans. BTW, I included a more straightforward alternate way of ordering the badges if you couldn’t figure out the date sequence. As Darth said, you can do a frequency analysis or line up the last letter of each row. You could even brute-force all 7! permutations (5,040). But all of those are too much work, if you ask me. Just take the first letter of each badge text block (C – C – E – N – N – O – T), and solve that like a JUMBLE puzzle — only one seven letter word works — CONNECT. Now you’re down from 5,040 permutations to 4. Read column two, and if you get R – E – A – R – S – G – E, for example, you’ve got the C’s reversed (positions 1 and 6) — so swap those badges around and you get G – E – A – R – S – S – E in column two, and you’re onto the next stage with directions in hand. :) Congratulations to Darth for a great puzzle, and looking forward to more.

ShmooCon 2012 Badge Puzzle

Fri, 03 Feb 2012 11:06:00 -0500

Speaker badge

For three years running, I (or I with a co-worker) have been the first person to solve the ShmooCon Badge puzzle. (I’m also, I believe, the only outsider to have solved the 2008 badge puzzle, but that’s another post). Seems like it’s time for me to stop playing.

So I asked Heidi if I could do the puzzle this year, and she agreed. We went back and forth many times over a few weeks, and got a lot of advice and suggested changes from G. Mark Hardy (who’d written the last three puzzles). Finally, just a few days before everything had to go to the printers, we put a fork in it and decided the puzzle was “done.”

ShmooCon 2012 Puzzle Data

Fri, 03 Feb 2012 11:06:00 -0500

The badge contest for ShmooCon 8 included several components – seven badges, five auto repair slips, a gear machine, and a short ciphertext.

ShmooCon 2012 Puzzle Slides

Fri, 03 Feb 2012 11:06:00 -0500

My slides from closing ceremonies for ShmooCon 8 (January 29, 2012). A walkthrough of the badge puzzle.

Changes to Apple MDM for iOS 5.x

Tue, 31 Jan 2012 10:11:00 -0500

Last Saturday (January 28), I presented an updated talk on Apple’s iOS MDM system at ShmooCon 8. I had a great time, and really enjoyed all the questions and nice comments I received afterwards. I thought I’d mention a couple of the changes that iOS 5 provide.

First, the devices support some additional restrictions and controls. These controls should be available in most commercial MDM solutions, and can also be found in the iPhone Configuration Utility (IPCU). Among these new controls are the ability to:

ShmooCon 2012 - Apple MDM Slides

Sat, 28 Jan 2012 04:00:00 -0500

My slides from ShmooCon 8, August 4, 2011.

iOS MDM Command Reference

Thu, 26 Jan 2012 12:00:00 -0500

Extract from my iOS MDM paper, detailing just the MDM protocol commands and responses. Updated for iOS 5.

Finding Which Root CAs You Actually Use

Fri, 02 Sep 2011 10:23:00 -0400

With all the recent talk about fake SSL certs issued by root-level Certificate Authorities at Comodo and DigiNotar and so forth, I thought it’d be interesting to run a little experiment. One thing that these compromises have highlighted is the huge number of root certificate authorities in modern operating systems and browsers. But how many of those are actually in use? How many sites that I visit are certified by each of the roots?

BlackHat 2011 Fidelis Puzzle - Archived Comments

Tue, 30 Aug 2011 09:35:00 -0400

Will Irace (@spblat)

August 30, 2011 at 9:35 pm

I am so glad our puzzle grabbed your brain and wouldn’t let go. :-) Thanks for a killer writeup.

How to Lose $1000 in Vegas Without Even Gambling

Tue, 30 Aug 2011 09:04:00 -0400

On July 15, Fidelis Security Solutions announced that they’d be running a crypto puzzle at Black Hat. And that the prize would be $1000. So, naturally, I was quite interested. I went to their site, downloaded the puzzle, and set to work:

^
¥Ð§µ    
¶®Æä
æ©×ä
÷ĳŒĐ
ƆķėĲ
ŦůŶū
ƂƐƔƆ
ŦƉƶǴ
ƆƅƦƬ
ǆƹɇʃ

As always, if you’d like to try to solve this yourself, then STOP now, as the rest of this post is full of spoilers. The text above is all that you need to get started, or you can click here to see the ciphertext and the hints that were revealed during the conference.

Fidelis Security "Decode This" Black Hat Challenge

Tue, 30 Aug 2011 05:02:00 -0400

Ciphertext:

^
¥Ð§µ    
¶®Æä
æ©×ä
÷ĳŒĐ
ƆķėĲ
ŦůŶū
ƂƐƔƆ
ŦƉƶǴ
ƆƅƦƬ
ǆƹɇʃ

Hints (provided every few hours via Twitter):

line breaks for clarity, not part of puzzle. neither is ^.
the word “Fidelis” is part of the message
get to know xxd
“yen” and “mu” are the same [used actual chars]
There are 20 characters in the message.
‘C2A5’ =~ /.{3}(.)/
Take a nybble out of each sybble. All you need is $1
50 75 6E 64
[a perl script to decode the ciphertext]

First Anniversary

Tue, 23 Aug 2011 08:46:00 -0400

A year ago today, I left the comfortable confines of an 18-year career in big-name Government contracting, and joined a very small security startup called Intrepidus Group.

It’s been an interesting year.

One major change – I’ve really stepped up my blogging. I’ve posted detailed analysis on issues ranging from the RSA breach (including a theoretical attack on their SecurID tokens) to the question of whether iPhones were tracking your location (I still say “no.”)

BlackHat 2011 Preview - Archived Comments

Sun, 21 Aug 2011 06:49:00 -0400

Barry

August 21, 2012 at 6:49 pm

David, great presentation. I wasn’t there to see it but have read through your whitepaper. Do you ever get involved with Open Source projects? Would love to speak with you about an open source MDM project that I am working on.

Strengths and Weaknesses in Apple's MDM System

Fri, 05 Aug 2011 09:21:00 -0400

Yesterday, for the first time, I headlined a talk at a major security conference. It was quite the experience, and not nearly as nerve-wracking as I might’ve expected. Actually, it was pretty easy – I took the approach that “this is some cool stuff I found, let me tell you about it” and kept a conversational mindset. Don’t know if that’s what experienced presenters do, but it worked for me, and I think I pulled it off. Achievement: UNLOCKED.

BlackHat 2011 - Apple MDM Paper

Thu, 04 Aug 2011 01:45:00 -0400

A detailed description of the Apple iOS Mobile Device Management (MDM) protocol. Presented at Black Hat USA on August 4, 2011.

BlackHat 2011 - Apple MDM Slides

Thu, 04 Aug 2011 01:45:00 -0400

My slides from Black Hat USA, August 4, 2011.

CarolinaCon Flag Puzzle - Archived Comments

Thu, 28 Jul 2011 11:27:00 -0400

G. Mark

July 28, 2011 at 11:27 am

Interesting observation about “shifting” the keys for ciphertexts 2 and 3. That wasn’t necessary if you feed the ciphertext into a Vigenère three times with the three keys. The offset is zero for each, beginning with the start of the message, so that the transition from one key to the other is not dependent upon the ciphertext length. Again, simplify. :)

BTW, for the winner of the crypto contest (Joel Kerr), I sent an NSA challenge coin and an official NSA reproduction of a Civil War field cipher wheel that would have been used for encoding/decoding messages during the war. – G. Mark

DEF CON 16 Puzzle - Archived Comments

Thu, 28 Jul 2011 11:18:00 -0400

G. Mark

July 28, 2011 at 11:18 am

Well done! Congratulations on solving yet another G. Mark crypto puzzle (and thank you for taking the time to make such a detailed write-up.) – G. Mark

Inside Apple's MDM Black Box -- Black Hat USA 2011

Thu, 28 Jul 2011 09:14:00 -0400

Since joining Intrepidus Group, I’ve spent a good deal of time helping to assess risk and craft security guidelines for iOS devices in large enterprises. A major factor in securing iStuff in the enterprise relies upon the use of Mobile Device Management technology (MDM). MDM has been around for a while, especially for some of the older, more corporately-established mobile devices (like BlackBerry or Windows Mobile). Last summer, though, Apple jumped into the arena, adding support for their devices as part of iOS 4.0.

Great Googly Moogly! I'm speaking at Black Hat!

Thu, 28 Jul 2011 09:02:00 -0400

One week from today I’ll be presenting a talk at Black Hat. Black Hat! Wow. I’m still a little amazed at this turn of events, but am trying not to dwell on it for fear of slipping into a blind panic. :)

But I think I’m ready. I submitted a nice long white paper a couple of weeks ago, and sent in my presentation yesterday. I’m comfortable with the material. I (think) I’ll be able to intelligently field questions. I’m pretty sure I won’t be a complete, blithering idiot on stage. And to settle my nerves, I’ve put in an early order for a bottle of Drambuie. Though I think I’ll save that for the obligatory post-talk celebration.

DEF CON 16 Punch Card Puzzle

Wed, 27 Jul 2011 10:15:00 -0400

Back in 2008, at DEF CON 16, G. Mark Hardy presented his second crypto challenge. I didn’t go to DC16, so I didn’t see the challenge (and even if I had, I wasn’t really tracking these at the time). But in 2010, at ShmooCon, he dusted the challenge off and handed it out again, as nobody had solved it yet. I’d managed, with a buddy, to solve the ShmooCon badge puzzle that year, and after I got home I started on the DC16 puzzle. It took me a few days, but I managed to beat it.

Nails in the Crypt - Archvied Comments

Mon, 23 May 2011 10:40:00 -0400

Andy

May 23, 2011 at 10:40 pm

Why such short chain lengths? Can’t you decrease the rainbow table size with a linear increase in search time by simply moving from 10,000 entry chains to 100,000 entry chains? Since chaining is cheap even with an expensive hash, it seems like an obvious win.

david_schuetz

May 24, 2011 at 2:31 pm

I needed something to work with, and in testing, 10,000 seemed workable while 100,000 was pretty slow. Keep in mind that the DES routine is slower than the MD5 (about 9x), so having the chain lengths about 1/10 the size keeps the times similar.

CarolinaCon Flag Puzzle

Sun, 08 May 2011 11:04:00 -0400

About two weeks ago, G. Mark Hardy asked if I was planning to attend CarolinaCon at the end of April. He had a puzzle set to go and was even thinking of using me as a clue. I replied that I wouldn’t be at the con, but would love to see the puzzle. So he sent me a copy.

Here is what he sent me, which was printed on the conference badge:

Analysis of iOS Location Data from Multiple Devices

Mon, 25 Apr 2011 05:21:00 -0400

This “Your iPhone Is Tracking Your Every Move!!” craziness just won’t go away. I’ve been kind of disappointed by the lack of very detailed analysis of the data that’s actually being collected, so I spent some time collecting information of my own.

I have access to four iOS devices running 4.0 or better: my personal iPhone 3GS, a family iPad with 3G subscription, a company-owned iPad (whose 3G has never been activated), and just arrived an iPad 2 that belongs to a client. So I spent some time this weekend trying to better understand what the Core Location daemons are doing.

Is the iOS 4 location tracking privacy issue overblown?

Wed, 20 Apr 2011 04:20:00 -0400

Earlier today, a story broke about a database on the iPhone that appeared to track the user’s location. The implication was that anyone could discover where, and when, the device’s owner had been.

As far as I can see, this is only partially true. I looked at the database on my own phone, and could see places I’ve been, including my home and office. However, contrary to what the current buzz seems to be, it’s not a long-term breadcrumb trail of my activities.

The 2009 Verizon Data Breach Investigation Report

Tue, 12 Apr 2011 11:45:00 -0400

In 2009, the Verizon Business Risk Team released their first public Data Breach Investigations Report. I saw it reasonably soon after release, and noticed a whole bunch of binary numbers in the background on the cover. “Cool,” I thought, but I didn’t bother trying to decode it. A week or so later, I learned that there’d been a contest, and I missed out. :(

In 2010, I was ready, and tried to solve the puzzle, but failed. That story comes later.

2009 Verizon DBIR Ciphertext

Tue, 12 Apr 2011 10:38:00 -0400

Background image on the report cover page:

01000101010101100100111001010100010110000100100101000111010110010100100101001101010101110101001101001110010001010
10010000100010101001001010001010100011001001111010101000101100001000010010100110100001101010111010110010100100001
01001001010001010011010101011101000111010101010101101001000001010000100101011001011001010000110100001001000010010
00110010100100100010101011001010001100100001001010110010001010100010001001011010001010101011001001101010001100101
00100100100101000110010011100100011101000110010011100101001001000010010001100100011101010110010010110101001101000
11001010000010011100100001001010101010001100101101001001010010001110100001101000101010001010100010101010111010000
01010010110100100001010000010110000100010101000010010101000101101001001010010000110101101001001111010101110100011
10101010001000010010100110101000101000111010101000100110101001001010000010101100101000100010100000101100101000100
01010010010010010101001001011001010001010101010001001011010000110100101001010010010100000101100101001000010001010
10100000101011101001011010101010100111101000001010001010100101101001110010101100101010001010110010110100100100001
01001101001101010110100100111001010100010101000100100101010110010010010100101101001101010011010101001001011001010
10011010011100101010101001001010000010100101101000010010100100100101101010001010011010101001101010100010110010100
00110100011101000011010000110101001001001100010100100101001001001001010010010101001001000101010001100100011101011
00101010100010010100101010101000010010101010101100001001000010001010101100101010011010001110100110001000101010110
01010100100101011001001000010010010101100101011000010001000100010101011001010110100100001101001010010010110101011
00101010001001111010100110100111101001001010110000100101001000101010010000100111101011000010001010101011001001101
01010111010010100100001001001110010110100100110101010100010010110101011101011010010001010100011001001111010001100
10000110100111001000010010101110100111001000011010101010101011101001101010110010100011001001001010101010101011001
00001001001011010101110100111001010000010101110101010001011001010011110100010101011001010100010101010001001001010
10010010100100101100101010010010000110100110101001110010101100100011001010110010011000101001001010011010000100100
11100101010001010000010101110101000001000001010011110100001101011010010100000100010101001011010010000100110001000
11001000011010001010100010101010010010100100101011001010111010101100101010101011001010000100101011001001010010100
00010101010101011001010000010011110100000101011001010011010100100101001011010100010101000101001110010100110101011
10101101001000111010010000101101001001011010001000100011101011001010011000100000101000101010001110101011101010000
01001011010001010101001101000111010000110101100101011010010001100101011001001010010001000100110101000101010100000
10100010100101101010011010100110100110001001110010101100101001101010110010100000101010101010110010101100101001001
01011001011001010001010101001001001000010001000101010001010101010101000101100101011001010011010101000101000111010
00101010101100101011101010010010011010101000101010011010110100100011001001110010100000100111001010010010010100100
10010100011101000111010101110100000101001010010011100100111001001010010011000100101101001111010001010101000101001
00001001110010001010101010001010010010100000101010101010001010110010100010001000110010110100101011101000011010110
10010010110101011001001010010001010101100001001100010011010100001101001011010000110101001101001001010001100101010
00100001101010100010100110101010101010100010011000100010001010010010100100100110101001001010010110101000101010100
01001110010010010100111001010000010001110101001001010000010100010101000101011000010100000101010001011010010001000
10100000100000101001001010011110101010001000011010001010101010101000001010110100100011001000101010101110100010001
01000101001100010011000101000001011010010100100100100001011000010011000101100001010001010001110101001101001100010
10010010010100101010001000010010011000101101001010010010010010101001001010110010010010101001101001110010110100100
10010101011101001100010011010101011001011001010000010100010001010110010011110100100001000110010001010101011001001
11001000001010010110100101101000111010011110101001001010010010110000101001101011001010001110101100001010000010101
01010011010101011001000111010000100100111101001101010100100100101001001100010000110101001001000101010001100100001
10100110101010010010100010101011001011000010101000100110101001001010110010100110101001010010010100101011001001000
01011000010011100100001001010100010100110101101001001101010101000100101001000101010001100100101101000110010001110
10010110101010101010010010001100100110001001110010010000101100001010000010010110100001101010111010011000100010101
01100001001101010010010101100101001100010001110101100101001110010011100101001001010111010000010100101101010011010
00101010101110101010001001000010100000100101101000111010110100100101101001011010110000100011101000001010110100100
01010100110001001100010101010101010001000001010110010100001101001001010001010100101101010111010010010101001101001
00001010101010011100100010001001011010001010100101101010111010000010101001001000111010000100101100101011010010001
10010001110100101101000101010100000100101101010001010001110101101001011010010100110101001001001001010011010100011
00100110001000111010010110100000101010010010101000101010101010010010000010100100101001110010100110100111001000111
01000101010001010101010101001101010001010101100001010010010101100100010101000101010011000101101001011000010101000
10010010101001101010101010101110101011001011010010010110100111101011001010011000101010001010000010000100100100001
01101001010111010001010100111101010001010101110100111001011000010011100101000001011000010100000100101101010011010
10011010110000100101001001000010100000100000101001110010000110101011001000110010100000101001001011001010000010100
01000101001001001100010100100100111101000101010101110100010101000010010100010100010101010111010010000101101001010
010010001110100000101 0101000101101001000100 
010001110101010101000 0110100010101001011010
01100010001100101100101001000010110100100101001001110010011100101101001001001010010100101001001000111010011100101
10100101001001010110010000100100111101000011010000010101010101011001010001010101101001000111010010110101000001010
01101001010010110000100101001001001010000010101001101001101010101100100011001010100010001000101011101000110010110
00010000100100100101000100010010000101000101011010010001010101100101001011010001000101001001010100010001000101001
00100100101001111010100000101000001001011010010100101001001010000010010010101001101010011010010110100110101000011
01011010010010100100011001011010010101000100001001010110010000100100101001010101010001110100010101011001010000010
10011100100101001001001010001110100101001010100010001000100001101010000010101000101101001000100010001010100111101
00011101010101010101000100110001011010010100000100010101001011010010000101010001001110010010010100100001010100010
00111010001110101010101001101010101100100011101000010010011110100110101010010010010100100110001000011010100100100
010101000110010100110101011101000110010110100100111101000011010100100100111101001000010001010100000101010101

Footnote on page 48:

NoVAHackers - Nails in the Crypt slides

Mon, 11 Apr 2011 11:00:00 -0400

Slides for my Nails in the Crypt talk on Rainbow Tables and UNIX Crypt() password hashes. Originally the talk was submitted to ShmooCon, but instead of presenting this talk I was asked to be part of the con’s closing panel, so I only spoke briefly about my research and saved the slides for later.

Quantifying the Unknown: Measuring a Theoretical SecurID Attack

Tue, 22 Mar 2011 11:03:00 -0400

It’s been a few days since the attack on RSA / SecurID was made public. Last Friday, I considered potential risks the compromise may pose to RSA’s customers. Since then, the security world has been buzzing with analysis of risks, worst-case scenarios, and second-guessing of the offical RSA press releases.

Late yesterday, RSA released additional information via their SecureCare system. However, as this is only available to RSA customers, I haven’t been able to directly review it. Rich Mogull, at Securosis, has posted his take in an update last night, and includes some very good, specific recommended actions. I’d like to take a moment to present some back-of-the-envelope numbers relating to a theoretical attack scenario, especially in light of what (little) was just revealed by RSA.

The RSA/SecurID Compromise: What is my risk?

Fri, 18 Mar 2011 08:32:00 -0400

So yesterday, RSA, a security division within EMC and the folks responsible for SecurID, one of the most popular forms of two-factor authentication, announced that they’d been hacked.

What does this mean? Well, we don’t have many details, but the most troubling bit is that apparently the attackers acquired information “specifically related to RSA’s SecurID two-factor authentication products.” In particular, that “this information could potentially be used to reduce the effectiveness of a current two-factor authentication implementation as part of a broader attack.”

RSA/SecurID Compromise - Archived Comments

Fri, 18 Mar 2011 05:42:00 -0400

HEscalona

March 18, 2011 at 5:42 pm

I believe that exist other scenario that is related to attacker get access to the backdoor that RSA put for government access inside the products and algorithms and all the complete system can be in danger.

I still thinking that: If RSA accept a success attack (a company that is alive for security) the real impact must be bigger than the actual acceptation.

iOS Overlays - Archived Comments

Sat, 12 Mar 2011 11:33:00 -0500

Benson

March 12, 2011 at 11:33 pm

That would totally work, and using Union mounts (http://en.wikipedia.org/wiki/UnionFS), it would probably take very little time and effort to implement. All you’d have to do is figure out how to union mount an expanding-as-needed file over the top of /users and /apps (or whatever places need to handle changes), and everything would fall into place

VeriFone vs Square - A Draw?

Wed, 09 Mar 2011 01:31:00 -0500

There’s been a lot of talk this morning about an open letter from VeriFone regarding the Square iOS credit card system. They make some pretty heavy accusations about a security hole in the Square system:

The issue is that Square’s hardware is poorly constructed and lacks all ability to encrypt consumers’ data, creating a window for criminals to turn the device into a skimming machine in a matter of minutes.

and another straightforward condemnation:

Crazy idea for multi-user iPads

Fri, 25 Feb 2011 11:43:00 -0500

While lying on the couch last Friday, trying to decompress after a busy day and expecting an even more hectic weekend, I had a crazy idea for how Apple might implement multiple user accounts on iOS devices like the iPad.

File System Overlays.

Applications in iOS are all restricted to their own sandbox – that is, they can only access files and data within their own application bundle, and nothing else. So right off the bat, data’s pretty well segregated.

Simple Bypass of Safari Restrictions on iOS

Tue, 15 Feb 2011 05:04:00 -0500

Okay, so in iOS you can disable things. To protect the user, the device, the organization, from misuse, etc. One of the things you can do is disable Safari, so the end user can’t surf to anything bad. (I’m being a little snarky – there are some good cases where you’d want to prevent end-user web surfing: Gambling sites. Porn. Chat rooms. Competitors’ tip sites. Stuff like that). It’s very easy, and appears to be very complete.

Bypassing MDM Restrictions for Mobile Safari on iOS 4.2

Tue, 15 Feb 2011 01:53:00 -0500

When deploying iOS devices, such as the iPhone or iPad, to a corporate population, the security-minded may ask “how can we keep people from using this device for inappropriate web surfing?” The easy answer is to use the restrictions available via profiles. This can be readily accomplished through a configuration profile that disallows Safari. The profile is easiest to create using the iPhone Configuration Utility (IPCU). It can then be installed on the device via the IPCU directly (usingUSB) or through a Mobile Device Management (MDM) system. Disabling Safari is simple: Just remove the checkbox next to “Allow use of Safari” and push the configuration to the target devices.

ShmooCon 2011 Puzzle - Archived Comments

Wed, 09 Feb 2011 10:38:00 -0500

Gort

February 9, 2011 at 10:38 pm

I was wondering when this was going to come out. I had to watch from home when they were going over the solution, but I hope to make it to a future session. Good work. Thanks for putting the effort into sharing this.

Jolly

February 9, 2011 at 11:34 pm

Nicely done! (Even if you do keep managing to beat me in his challenges :P)

ShmooCon 2011 Badge Contest

Wed, 09 Feb 2011 09:39:00 -0500

Ah, ShmooCon 2011. This time we’re in a new building, The Washington Hilton, and a little earlier than usual: the last weekend of January. But aside from that, it’s still ShmooCon. And it wouldn’t be a ShmooCon without something fun on the badges. For the third year in a row, the puzzle came from the subtle and devious mind of G. Mark Hardy.

This time, I was actually helping out at the con. I’d been a little concerned about whether I’d be able to fairly compete for the puzzle, since I might get exposed to the badges, or programs, or other material, before anyone else is. Heidi did her best to ensure that I didn’t learn anything unfairly – to the point that the Wednesday before the con, when I was helping with some of the check-in code and at the bag stuffing party, she repeatedly told everyone that “David’s not allowed to see inside the programs!” She’s so helpful.

ShmooCon 7 Ciphertexts

Wed, 09 Feb 2011 03:45:00 -0500

Badge data. Morse code, two lines per badge.

..--- -.-- . ... - . .-. -.. .- -.-- 
...-- - . .-.. . --. .-. .- .--. .... 

----- -- --- --. .- -.. .. ... .... ..- 
.---- .- .-. -- .- -.. .. .-.. .-.. --- 

....- .... -.-- .--. -. --- - .. ... - 
..... . ..- -.-. .- .-.. -.-- .--. - .. 

---.. --- .-. .- -. --. . -.-. .- -... 
----. ... - .. -- ..- .-.. .- - . 

-.... -- .. -.-. .-. --- -... .-. . .-- 
--... --- -... .--- . -.-. - .. ...- .

Large letters, one per page, from the bottom of twenty pages in the program:

Breaking a 147-Year-Old Message

Thu, 30 Dec 2010 11:50:00 -0500

Last weekend, the Associated Press published a story about a Confederate Army message that was recently decrypted. It had been written on a small sheet of paper, rolled up tightly and placed in a glass vial with a bullet (probably so it could be sunk into a river in the event of imminent capture). The vial sat in The Museum of The Confederacy for years, until it was unrolled early in 2009. The article didn’t say when the message was decoded – presumably it sat untouched for a while and they only just sent it out to the experts (one at the CIA, one at the Navy).

Civil War Code Ciphertext

Thu, 30 Dec 2010 11:15:00 -0500

Here are three variations of the message I broke in my blog post about the recently-unrolled Civil War Code. First, the ciphertext as best I could transcribe from a high-resolution photograph:

SEAN WIEUIIUZH DTG CNP LBNXGK OZ BJQB FEQT XZBW JJOA
TK FHR TPZWK PBW RYSQ VOWPZXQQ OEPH EK WASFKIPW PLVO
JKZ HMN NVAEUD XYF DWRJ BOYPA SF MLV FYYRDE LVPL
MFYSIU XY FQEO NPK M OBPC FYXJFHOHT AS ETOV B OCAJOSVQU
M ZTZV TPIY DAW FQTI WTTJ J DQGOAIA FLWHTXTI QMTR
SEA LVLFLXFO

Now, that same text cleaned up, once I’d recovered the key and corrected all the encoding, transcription, and handwriting interpretation errors:

Civil War Ciphers Fall!

Thu, 30 Dec 2010 04:16:00 -0500

About a week ago, a story hit the wires about a recently-discovered coded message from the Civil War. It had been sealed in a vial, in The Museum of The Confederacy, for years, and was only recently unfolded and decoded. The story was relayed to me with the challenge “extract the key,” so I did.

Actually, it wasn’t quite that easy, but upon looking at the photograph of the message, I was quite surprised to see what I understood to be a major error: the writer of the message had left word breaks intact in the ciphertext. This gives me a significant leg up on trying to break the code.

Nails in the Crypt

Wed, 22 Dec 2010 11:19:00 -0500

Some time ago, I started wondering why I couldn’t find any Rainbow Tables for old-school Unix crypt(3) passwords. After some research, I learned that the salt was the culprit – that virtually anyone who’d asked about such tables went away chastised, told that the salt made it impossible to generate Rainbow Tables, unless you went through the trouble to create 4096 different tables (one for each salt). And who’s going to do that?

Rainbow Tables for Unix DES Crypt(3) Hashes

Mon, 20 Dec 2010 11:18:00 -0500

Some time ago, I started thinking about the possibility of using Rainbow Tables to crack old-school Unix crypt(3) passwords. Nobody had done this, and the reason most often cited was the presence of the two-character salt at the beginning of the hash.

This didn’t make a whole lot of sense to me. I mean, 2 characters? Isn’t that essentially like taking an 8-character password space and making it a 10-character space? People are already creating 10-character tables for other hash algorithms. Why can’t we do this for crypt(3)?

ToorCon 12 Puzzle - Archived Comments

Tue, 07 Dec 2010 05:18:00 -0500

kryptosfan

December 7, 2010 at 5:18 pm

Just out of professional curiosity – would you be willing to try your multi-skip detection program on K3 of Kryptos? My favorite method involves a skip step because it keeps the “?” in the final plaintext whereas the other two traditional methods exclude it to get a solution.

Darth Null

December 8, 2010 at 11:11 am

Interesting idea, but the reason my approach worked here is that there was a small message hidden within a large amount of noise. My script just separates the signal from the noise. In K3, it’s all signal, no noise. So even though K3 can be solved with a “skip” approach (wasn’t it like every 192nd character?), it’s not the same kind of approach as what we have here.

ToorCon 12 Badge Puzzle Ciphertexts

Mon, 06 Dec 2010 10:32:00 -0500

Here are all the parts you’ll need to know to try and complete the puzzle yourself. Included are a picture of the conference badge, some mysterious clocks scattered all throughout the program, a snippet of Morse code that was printed along the edge of the last page of the program, ciphertext from the back of the con T-shirt, and, finally, a page full of ciphertext from the back of the program.

ToorCon 12 Badge Puzzle

Mon, 06 Dec 2010 10:31:00 -0500

In the middle of October, G. Mark Hardy emailed to ask if I or my puzzle-busting buddy would be making it to ToorCon, in San Diego, as he had a puzzle on which he was putting the finishing touches. I told him no, but that I’d love to play along at home for “bragging rights instead of prizes.”

The weekend of the conference I was actually at a cousin’s wedding. So I didn’t expect to have much time to play. However, I did bring along some gear, and spent some time Friday night and Saturday afternoon playing with the little information that had leaked out from the Con.

THOTCON Pre-Sale Code Puzzle

Mon, 22 Nov 2010 02:55:00 -0500

THOTCON is an information security conference in Chicago. And they did a puzzle last year, that I solved, and got a really cool Sake decanter as a prize. The guy who did the puzzle, Sak3bomb, did another puzzle for the next THOTCON – this one for a pre-sale prize in advance of next spring’s conference.

Problem is, the puzzle came out while I was at the beach. When I was supposed to be resting. At 1:30 in the afternoon, on September 17th. Of course, I didn’t see it until about 9:00 in the evening. When I was supposed to be resting.

DEF CON 18 Crypto Challenge

Thu, 02 Sep 2010 11:11:00 -0400

DEF CON 18. July, 2010. Riviera Hotel, Las Vegas. G. Mark Hardy tells us that he’s just launched another crypto challenge, and the clues are all on the DEF CON CD. The game, as they say, is afoot.

So my buddy Дурак (gypak, Durok) and I start poking around to see what’s on the CD. We’re both using netbooks, so we have to wait until later to hook up the CD drive I remembered to bring, then copy the disc to both netbooks. And read through G. Mark’s presentation…

DEF CON 18 Crypto Challenge Ciphertexts

Thu, 02 Sep 2010 11:10:00 -0400

This is some of the source material for G. Mark Hardy’s DEF CON 18 Crypto Challenge. It’s obviously not possible to archive the contest exactly, so I’m just going to provide the pertinent ciphertexts and clues here. I’ll keep them hidden (blue on blue) so that you can’t accidentally see the next stage until you actively highlight the text.

Try not to look too far ahead, because even the intervening text may give too much away.

Puzzles and Contests

Sun, 29 Aug 2010 09:03:00 -0400

I’ve always liked puzzles. As kids, we were constantly working on jigsaw puzzles of ever increasing size and complexity. Whenever an article about Mensa appeared in the newspaper, my dad would give me the sample questions from it to figure out. And when I started Geocaching a few years back, that love for puzzles returned stronger than ever.

I currently work in the information security industry. The security community has many conferences throughout the year at which people gather to discuss research, reconnect with colleagues from across the country, and occasionally play some games.

ShmooCon 2010 Badge Puzzle Data

Sun, 29 Aug 2010 08:47:00 -0400

Here’s the raw data from the ShmooCon 2010 Badge Contest.

268	-28.09944	4995	140.196944	attendee badge
313	41.663679	3698	-1.011665	attendee badge
150	59.158051	2926	-2.641389	attendee badge
118	-0.413773	6187	35.251589	attendee badge
0	-4.674342	0	55.521839	security badge
42	49.971153	4584	-94.700518	speaker badge
114	17.205642	5251	-62.594003	safety brochure
345	-22.612239	3973	17.080442	program
122	29.95925	1281	-81.33975	schedule poster 1
166	40.137722	2473	26.426777	schedule poster 2
301	13.266669	5572	19.716677	schedule poster 3

ShmooCon 2010 Badge Contest

Sun, 29 Aug 2010 08:39:00 -0400

Every year, the Shmoo Group runs an information security conference in Washington called ShmooCon. I’ve been going every year, and it’s both a fantastic con and a great deal. The conference in 2010 was memorable because it coincided with the worst snowstorm Washington’s had in decades. It was also memorable for me as another victory in the badge puzzle contest.

ShmooCon 2010 Badge

Last year, my buddy Дурак (@gypak – more or less “Durak,” pronounced “doo-rock”) and I attacked the badge puzzle in parallel, working more-or-less independently but sharing progress, ideas, problems, etc. After a couple of weeks, he gave up, but I kept on for a few more days and ended up winning the contest (beating the next team by just over an hour). This year, Дурак and I worked as a team from the start, and again, were the first to solve the puzzle, landing us fabulous prizes and numerous bragging rights.

Quahogcon Flag Puzzle - Archived Comments

Tue, 24 Aug 2010 09:45:00 -0400

H3xan01c

August 24, 2010 at 9:45 pm

Finally I have some closure on this and a chance in upcoming contests. I attended Quahogcon. During the initial Friday nights sign in my wife and I went over the contest and she solved the sudoku while we had a drink. She went on her way as we had traveled 9 hrs from north of Toronto and she was in town to shop while I geeked out. I showed a few people I met her solution to side one of the puzzle and it seemed a good chuckle. I admit that after Hacker Jeopardy my beer intake never allowed me to get back to the puzzle. And I also admit that during closing ceremonies I was reluctant to offer up her solution to side one, my mistake and she never lets me forget it. I had attempted to solve it on and off for a few weeks after the con. I have pages of data shifting side 2 based on the side one sudoku resolution. I was fixated I guess on the 1-9 ordering and using that to re-arrange columns and/or rows of the 2nd side. It forced me to study up on many types of cipher so it was still a useful process.

QuahogCon Flag Puzzle

Thu, 20 May 2010 02:08:00 -0400

Shortly after completing the ShmooCon 2010 badge puzzle, G. Mark Hardy told me in that he’d be contributing a puzzle for QuahogCon, the last weekend of April. I knew I wouldn’t be attending, so I offered to proofread the puzzle before he published it. I never heard back, so a couple days before the con I asked if I could play along at home (provided, of course, it was okay with the conference organizers).

THOTCON 0x1 - Archived Comments

Tue, 11 May 2010 02:03:00 -0400

Jeff Jarmoc

May 11, 2010 at 2:03 pm

Nice write up! Thanks for sharing. I didn’t end up completing the whole thing, but enjoyed the parts I did complete.

One thing that could’ve saved you some time; if you run strings or hexdump on ironman.jpg, you’ll see ‘steg hide’ near the beginning. That happens to be the name of a tool that’ll decode the steg in AHH.jpg. :)

$ hexdump -C ironman.jpg | head -c 256
00000000 ff d8 ff e0 00 10 53 74 65 67 00 01 01 01 00 60 |……Steg…..`|
00000010 00 60 00 00 ff e1 00 16 68 69 64 65 00 00 49 49 |.`……hide..II|
00000020 2a 00 08 00 00 00 00 00 00 00 00 00 ff db 00 43 |*…………..C|

Darth Null

May 11, 2010 at 2:56 pm

That’s a huge D’Oh! on my part. Sakebomb just told me that offline, and I’ve updated my post. Yeah, seeing that would’ve saved me a LOT of time. :) And, my original post had the wrong tool name given…just misread my notes.

THOTCON 0x1 Puzzle

Tue, 11 May 2010 01:14:00 -0400

So on April 23rd, while I was waiting for the QuahogCon puzzle to post, over in Chicago THOTCON was starting. And a few days later, I saw a tweet from @sak3bomb saying:

I am sad that no one found any of the links I hid in the #thotcon program. Maybe next year...

My immediate response was to ask “There’s a puzzle?” He replied that he wanted to give the attendees from the conference a couple more days, then on April 30th, the program was posted to the THOTCON site. I kind of glanced at it, saw a few URLs hidden in the front page ASCII art, and forgot about it (as I had a trip coming up and had to prepare).

ShmooCon 2009 Badge Contest

Tue, 27 Apr 2010 11:15:00 -0400

ShmooCon is a great security conference, held early each year in Washington, D.C. They frequently feature a puzzle contest connected to the conference badges. In 2006, the badges were die-cut pieces of metal that could all fit together to create one large badge. Renderman figured that one out. In 2008, they had 16 different plastic badges that looked like punch cards, and somehow or other eventually gave you a PDP-8 program that would decrypt some text and, well, that one was a bit crazy and nobody solved it.

Crazy Security Con Weekend!

Fri, 23 Apr 2010 08:00:00 -0400

I don’t go to a lot of information security cons. I’ve been to all the ShmooCons (they’re local, after all), and to DEFCON 3 times (plus a couple of BlackHats back when the company was paying for the trip). So, really, like 2 a year. That was pretty much my world – and I knew there were a couple others, but didn’t really pay much attention.

Belief-vs-Skepticism - Archived Comments

Tue, 20 Apr 2010 03:09:00 -0400

Bryan Schuetz

April 20, 2010 at 3:09 pm

“”Would Gizmodo really have it in so bad for the entire community that they’d try to play everyone with an elaborate hoax? That too, seems unlikely.”"

Remember though that this is the same site that left the whole community agonizing over a long weekend back in 2006 by claiming they had the details on the new iPhone before it was launched. Come Monday and the big reveal, it just turned out to be a new product from Cisco. http://gigaom.com/2006/12/17/iphone-is-available-but-not-that-iphone/ I don’t think this was a hoax, but I do think they’ve got the all douche nozzle credentials that would be required for such an endeavor.

Blind Belief vs Excessive Skepticism

Tue, 20 Apr 2010 02:11:00 -0400

I’m going to go out on a limb and say that I’m still skeptical about the whole “Gizmodo’s got a 4th generation iPhone” story. Yes, it looks a lot like it could be real. And they’re saying all the right things. But the one thing that I can’t get over is this: they’re only saying those things.

There’s still no real proof. Everything we know about this comes from Gizmodo (other sites with pictures claim to have only received those photos, none of them have actually handled the unit).

Half-Baked Idea: Isolate Browser Security Contexts to Limit XSS Attacks

Wed, 14 Apr 2010 04:58:00 -0400

So I was reading yesterday about the Cross-Site Scripting [attack against apache.org](https://blogs.apache.org/infra/entry/apache_org_04_09_2010. And it struck me that there might be an easy way to reduce or eliminate a lot of these attacks, using better isolation within the browser.

Essentially, my thought boiled down to this: Why, when I load a page in the browser, should that page have access to cookies from another server?

“But it doesn’t,” you might say. “The same-origin policy on cookies prevents one page from accessing another server’s cookies!” True. But if the malicious page manages to convince your browser to load a page from the target server, with its own cookie-stealing XSS code injected, then that malicious page, indirectly, has access to those cookies.

It's Time To Start

Wed, 14 Apr 2010 04:56:00 -0400

I’ve got a blog on another site. Sort of. It’s never updated. It’s been over a year since the last posting, and, frankly, that’s embarrassing. However, I’m constantly thinking of things that I want to talk about, that won’t fit into the limitations of Twitter or Facebook status updates. But because I never post anything, I don’t post anything new, ‘cause then I’d look like an idiot who never posts anything.

Drafts Archive

Mon, 01 Jan 0001 00:00:00 +0000

InfoSec Archive

Mon, 01 Jan 0001 00:00:00 +0000

InfoSec Archive

Mon, 01 Jan 0001 00:00:00 +0000

misscellany Archive

Mon, 01 Jan 0001 00:00:00 +0000

Puzzles and Fun Archive

Mon, 01 Jan 0001 00:00:00 +0000

Site Archives

Mon, 01 Jan 0001 00:00:00 +0000

Talks and Presentations

Mon, 01 Jan 0001 00:00:00 +0000

A quick list of the talks and presentations I’ve given, and papers or other publications I’ve contributed to.

2011

ShmooCon: Closing panel - Past, Present, and Future of “Something you know”
NovaHackers: Nails in the Crypt
Black Hat USA: Inside Apple’s MDM
NovaHackers: The ShmooCon Ticket System

2012

ShmooCon, University of Wisconsin Lockdown: Inside Apple’s MDM (updated)
IntrepidCon: Solving the Verizon DBIR Puzzle
DerbyCon: Slow Down, Cowpoke - When enthusiasm outpaces common sense (importance of a methodical approach to Infosec testing)
TV appearance: NBC News interview - Solving the Apple / “FBI” UDID data breach (Today Show, September 11, 2012).
NovaHackers: Apple UDID Breach
Private seminar: Apple UDID Breach

2013

ShmooCon, Source Boston, University of Michigan SUMIT_13, seminar at Federal Government customer: Protecting sensitive information on iOS devices
DerbyCon: Raspberry Pi, Media Centers, and AppleTV

2015

ShmooCon: Knock Knock: A Survey of iOS Authentication Methods (also presented in 2015 at OWASP DC and OWASP NoVA)

2016

ShmooCon: My Hash Is My Passport: Understanding Web and Mobile Authentication
BSides Rochester and University of Connecticut TakeDownCon: A (not so quick) Primer on iOS Encryption

2018

NovaHackers, BSides Delaware: 1Password Internals

2019

Staying Secure At Home (Internal Expel talk)

2020

Introduction to Cryptography (Internal Expel talk)

Papers, Publications, and Training

Nails in the Crypt - Proof of concept demonstration of rainbow tables with salted UNIX crypt(3) password hashes
Co-author and initial co-presenter of SANS class “Secure Mobile Applications Development: iOS App Security”
Author and instructor of iOS half of 3-day application security testing course for private customer
Author of mobile platform security comparison chapter of NCC Group “End-to-End Mobile Security” whitepaper, released at Mobile World Congress 2013
Released research server for iOS Mobile Device Management
Released test and demonstration software for directly accessing 1Password vaults, with detailed blog post series to support talk and software
CVE-2014-1279: Disclosure of AppleID and Wi-Fi Passwords During Apple TV Touch Setup