Kryptographie
Hauptthemen der Kryptographie für Pentester
1. Symmetrische Kryptographie
- AES (insb. AES-GCM & AES-CTR)
- Betriebsmodi (CBC, CTR, GCM)
- IV/Nonce-Handling
- MAC/HMAC
- Authenticated Encryption (AEAD)
2. Asymmetrische Kryptographie
- RSA (Verschlüsselung & Signaturen)
- ECC (ECDSA, ECDH)
- Diffie-Hellman (DH, ECDH)
- Key Exchange & Padding (PKCS#1, OAEP)
3. Hashfunktionen
- SHA-2 / SHA-3
- BLAKE2/BLAKE3
- Unsichere Hashes: MD5, SHA-1
- Kollisionen, Präbilder, Integrität
4. Passwort-Hashing & Cracking
- bcrypt, PBKDF2, scrypt, Argon2
- Salt, Pepper
- Offline-Cracking (hashcat, JtR)
- Hash-Misuse in Apps
5. Digitale Signaturen & PKI
- RSA-PSS, ECDSA, EdDSA
- X.509-Zertifikate
- TLS-Zertifikatsvalidierung
- Certificate Pinning (Web/Mobile)
6. TLS/SSL & SSH Kryptographie
- TLS 1.2/1.3 Handshake
- Cipher Suites
- Perfect Forward Secrecy
- SSH Key Exchange, Ciphers, MACs
- Häufige Fehlkonfigurationen
7. Krypto-Misuse in Anwendungen
- Hardcoded Keys
- Falsche Modi (z. B. ECB)
- Unsichere Randomness
- Nonce/IV Reuse
- Custom Crypto
- Fehlimplementierte JWT/Cookies
8. Krypto-Angriffe (praktisch für Pentester)
- Padding Oracle Attacks
- Bleichenbacher RSA
- Replay & Downgrade Attacks
- Weak Key/Short Key Attacks
- Timing Attacks (High-Level)
- JWT None-Exploit, Algorithm Switch
9. Token, API-Auth & Web-Kryptographie
- JWT (HS256/RS256, kid-Parameter, JWK)
- OAuth2/OIDC Signaturen
- HMAC-gesicherte API-Requests
- Signed Cookies
- CSRF-Tokens (kryptographisch)
10. Cryptographic Storage in Apps
- Secure Storage vs. Plaintext
- Mobile App KeyStore/KeyChain
- Datenbanken: TDE, Application-Level-Encryption
- Secret Management (Vault, KMS)
11. Key Management & Lifecycle
- Key-Generierung
- Key Rotation
- Secrets Management
- Cloud KMS / Vault
- Umgang mit kompromittierten Schlüsseln
12. Post-Quanten Kryptographie (nur Überblick)
- Kyber (KEM)
- Dilithium (Signatur)
- Relevanz für TLS/SSH
- Hybrid-Kex
AES, Cybersecurity, Digitale Signaturen, Hashing, IT-Sicherheit, Kryptographie, Public Key Infrastructure, RSA, Secure Communication, TLS, Verschlüsselung