README

AES256 Lab (Pascal/Lazarus) — Educational, Transparent Implementation

⚠️ Educational project — NOT production-grade cryptography!

This repository implements AES-256 from scratch in Pascal/Lazarus, intentionally without external crypto units or packages. The goal is transparency and learning: every step is readable and discussable.

Do not use this code to protect real data. Real-world security requires much more than “AES works”:

• correct key derivation from passwords (KDFs like Argon2/PBKDF2 + salt + iterations)
• correct IV/nonce handling and safe defaults
• integrity & authenticity (AEAD / MAC) — not only confidentiality
• secure randomness (CSPRNG), key management, error handling
• side-channel considerations, secure wiping, extensive testing & review

If you need real encryption, use well-audited libraries (e.g. libsodium, OpenSSL, Botan, or platform crypto APIs).

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Documentation (German project language)

The main documentation is in German:

➡️ Main documentation (German): README.de.md

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Quick Start (Lazarus)

1. Open Lazarus
2. Load the project: src/aes_256.lpi
3. Build & Run
4. Use the GUI to try encryption/decryption and run tests (if available in the UI)

Tip: If you run into build output folders, they belong into lib/ and should be ignored by Git (see .gitignore).

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Screenshot

Learning Path (Docs)

This repo includes a step-by-step learning path in docs/:

• docs/00_Project_Map.md
• docs/10_AES_Introduction.md
• docs/20_AES_Key_Schedule.md
• docs/30_AES_Block_Operations.md
• docs/40_AES_Modes_ECB_CBC.md
• docs/50_Security_Notes.md

Additional references:

• docs/60_How_to_verify_with_test_vectors.md
• docs/70_Unit_Reference.md
• docs/80_Glossary.md

Project Structure

• src/ — Lazarus project + Pascal source code
  • aes_256.lpr / aes_256.lpi — project entry
  • aes_256_lab_main.* — GUI (main form)
  • uAES256*.pas — AES implementation and modes
  • uSHA256.pas — SHA-256 implementation (used for educational key derivation)
• docs/ — educational documentation
• .github/ — issue/PR templates

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License

Licensed under the GNU Affero General Public License v3.0 (AGPL-3.0).
See LICENSE.

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Contributing

Contributions are welcome — especially improvements to documentation, test vectors, and beginner-friendly explanations.

See CONTRIBUTING.md.

Author / Motivation

Created by Jörg Liebetanz as a transparent AES-256 learning project in Pascal/Lazarus (no external crypto packages), focused on readability and education.

If you use this for teaching or want to contribute improvements (docs/tests), feel free to open an issue or PR.