The "iMAS Encrypted Code Modules" security control mitigates static attacks - allows section of source code to be encrypted into a .dylib at build time and decrypted at run-time. It protects the code against static analysis and forces an attacker to perform a dynamic attack. When used in concert with other iMAS security controls, ECMs will raise an applications security significantly.

1. Binary patching can lead to dangerous function being added and invoked

• CWE-676: Use of Potentially Dangerous Function
• CWE-494: Download of Code Without Integrity Check

• iOS Static App attacks are very common
• Code injection and binary patching can compromise app
• Application Integrity is critical to thwarting these techniques
• Implementing App Integrity is difficult
• iMAS introduces ECM

Below is a diagram showing the components for ECM

Download code, compile ECM Demo App last. Connect xcode to a iOS7 device and run.

• git pull encrypted_code_modules
• Make sure that each project is putting derived data relative to the project. This can be accomplished in XCode by going to File->Project Settings... and selecting "Project-relative" from the dropdown.
• Verify that an executable is set for ECM Build for the demo. To do do this go to Product->Scheme->Edit Scheme.. select Run imas_ecm_demo from the left panel, and then imas_ecm_demo_app.app in the Executable drop-down.
• Compile the ECM Demo App last. Make sure to use the ECM Build target.
• Ensure XCode scheme is set to ECM Demo App > < device only >
• Clean, run and explore

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