Shadow Stack Security Mechanism (CFI)

This project implements a software-based Shadow Stack mechanism to ensure Control Flow Integrity (CFI) on x86-64 architectures. It protects function return addresses from buffer overflow attacks.

Project Structure

• main.c: Binary Search implementation with attack simulation.
• main_matrix.c: Matrix summation with nested function call tests.
• security_layer.h/c: Core Shadow Stack logic and macros.
• Makefile: Automated build and test script.

How to Build

To compile all versions (secured and non-secured), run:

• ./binary_with_security : This version demonstrates how the shadow stack detects a compromised return address
• perf stat ./binary_with_security / perf stat ./binary_no_security : To measure execution time and instruction overhead using perf
• ./matrix_with_security : To verify shadow stack stability during nested function calls

Implementation Details

The security layer uses SHADOW_PROLOGUE() and SHADOW_EPILOGUE() macros.

Prologue: Captures the return address using __builtin_return_address(0) and stores it in an isolated shadow stack.

Epilogue: Compares the hardware stack's return address with the shadow stack copy. If a mismatch is detected (Attack), the program terminates immediately.

##Performance Summary Execution Overhead: ~30.4%

Instruction Overhead: ~2.4 instructions per function call.

Detection Rate: 100% against simulated return address manipulation.