Control Flow Flattening¶
Introduction¶
Control flow flattening is a code obfuscation technique that operates on the control flow graph. Its basic idea is to reorganize the relationships between basic blocks in a function's control flow graph by inserting a "main dispatcher" to control the execution flow of basic blocks. For example, the following is a normal execution flow:
After control flow flattening, it becomes like this, with a "main dispatcher" responsible for controlling the program execution flow:
Through control flow flattening, the predecessor-successor relationships between basic blocks are obfuscated, thereby increasing the difficulty of reverse analysis. For more implementation details on control flow flattening, refer to this paper.
Using Symbolic Execution to Remove Control Flow Flattening¶
Under construction.
Reference¶
Tencent Security Response Center - Using Symbolic Execution to Remove Control Flow Flattening