Evading AV/EDR: Shellcode Cryptography in Rust with XOR & AES-GCM

In this module, we bridge the gap between low-level security tradecraft and high-level Rust engineering. We build a production-grade CLI tool that automates the encryption and decryption of shellcode, moving from basic XOR obfuscation to authenticated AES-256-GCM encryption.
The goal of this project is twofold: understanding why modern EDRs signature simple XOR loops and mastering the advanced Rust patterns required to build a modular, memory-safe security tool.
Part 1: Advanced Rust Engineering
We don't just write code; we architect a system. This project serves as a deep dive into:
Abstraction with Traits & Dynamic Dispatch: Using Box dyn Trait to switch encryption engines at runtime.
The Type System: Leveraging Enums and Unit Structs to represent different cryptographic strategies.
Functional Programming: Using Iterators and the Map function for memory-efficient data transformations.
Metaprogramming: Using Derive Macros (Debug, Clone, Copy, PartialEq) to reduce boilerplate.
Error Handling: Using map_err to lift low-level library errors into readable CLI output.
Part 2: Security & Cryptography
We apply these Rust concepts to solve real-world security challenges:
XOR Obfuscation: Implementing bitwise transformation and discussing why it fails against heuristic EDR analysis.
AES-GCM Authenticated Encryption: Why Integrity matters. We explore how the Authentication Tag prevents shellcode tampering.
CLI Development: Building a functional interface to ingest raw .bin payloads and output encrypted buffers.
Memory Lifecycle: Preparing encrypted payloads for safe decryption in a loader environment.

Key Implementation Details:
Implementing the Encryptor Trait.
Handling the Nonce and Tag in AES-GCM.
Using std::io for robust terminal I/O (Flush, Read, Write).

Target Audience: This video is for developers who want to see Rust's high-level abstractions applied to low-level security problems, Red Teamers and Security Engineers who are interested in Rust programming