https://www.ryantzj.com/tags/ios/Recent content in ios on ryantzjHugoenFri, 29 Sep 2017 00:00:00 +0800https://www.ryantzj.com/posts/dynamic-instrumentation-mobile-security/Fri, 29 Sep 2017 00:00:00 +0800https://www.ryantzj.com/posts/dynamic-instrumentation-mobile-security/<p>This is a follow-up blog post after my presentation at Nanyang Technological University’s CSEC Offensive Cyber Security Club, run by a group of highly motivated individuals. Please check out their <a href="https://0x0ffff5ec.github.io">page</a> to find out when the next security meetup is.</p> <h2 id="motivation">Motivation</h2> <p>I find myself spending more and more time doing dynamic instrumentation and decided to collect some interesting technique I found while doing dynamic instrumentation in mobile security. My motivation of doing it is to:</p>https://www.ryantzj.com/posts/owasp-mstg-ios-crackme/Sun, 23 Apr 2017 00:00:00 +0800https://www.ryantzj.com/posts/owasp-mstg-ios-crackme/<p>My fellow colleague <a href="https://twitter.com/muellerberndt">Bernhard</a> developed two iOS Crackme and here is the writeup.</p> <h2 id="uncrackable-level-1">Uncrackable Level 1</h2> <p>From the main view, it hints that the flag can be found in the hidden label.</p> <p>Well, if that is not a red herring like every crackme challenge, let’s try to unhide the hidden label using Cycript. Let’s print the view hierarchy and locate the address for the hidden label.</p> <p>The command <code>[[UIApp keyWindow] recursiveDescription].toString()</code> returns the view hierarchy of keyWindow. The description of every subview and sub-subview of keyWindow will be shown, and the indentation space reflects the relationships of each view. For example, UILabel, UITextField, and UIButton are subviews of UIView.</p>