Review cryptographic implementations for vulnerabilities including weak algorithms, timing attacks, and key management issues.
You are a cryptography security expert. Review the following cryptographic implementation for vulnerabilities. ## Review Target - **Code/System**: [CODE e.g. paste code or describe the system] - **Language**: [LANG e.g. Python / Java / Go / Rust / C++] - **Crypto Library**: [LIBRARY e.g. OpenSSL / libsodium / Bouncy Castle / cryptography.io] - **Use Cases**: [USES e.g. data encryption, digital signatures, password hashing, TLS, key exchange] ## Review Areas ### 1. Algorithm Selection - Check for deprecated algorithms: DES, 3DES, RC4, MD5, SHA1 - Verify key sizes: RSA ≥ 2048, AES ≥ 128, ECDSA ≥ P-256 - Recommend modern alternatives: ChaCha20-Poly1305, Ed25519, Argon2id - Assess algorithm suitability for [USES] - Check for quantum-resistant considerations (ML-KEM, ML-DSA) ### 2. Implementation Flaws - **Random number generation**: Verify use of CSPRNG, check seeding - **IV/Nonce handling**: Uniqueness verification, reuse detection - **Padding**: Check for padding oracle vulnerabilities (PKCS#7, OAEP) - **Mode of operation**: Verify appropriate mode (GCM for AEAD, not ECB) - **Timing attacks**: Constant-time comparison for MACs and signatures - **Error handling**: No information leakage in crypto error messages ### 3. Key Management - Key generation: sufficient entropy, proper derivation (HKDF, PBKDF2) - Key storage: not in source code, use key vault/HSM - Key rotation: mechanism exists, old keys handled properly - Key destruction: secure memory wiping after use - Key exchange: proper protocol (ECDHE, X25519), forward secrecy ### 4. Protocol Analysis - TLS configuration: minimum version (1.2+), cipher suite ordering - Certificate validation: hostname verification, chain validation, pinning - Custom protocols: replay protection, message ordering, freshness - Authentication binding: tokens tied to session keys ### 5. Data Protection - Encryption at rest: AES-256-GCM or XChaCha20-Poly1305 - Encryption in transit: TLS 1.3 preferred - Password hashing: Argon2id with proper parameters (memory, iterations, parallelism) - Envelope encryption for large data sets - Authenticated encryption (AEAD) usage verification ## Output For each finding: 1. **Severity**: Critical / High / Medium / Low 2. **Category**: Algorithm / Implementation / Key Management / Protocol 3. **Issue**: Description of the vulnerability 4. **Impact**: What an attacker could achieve 5. **Current Code**: The vulnerable implementation 6. **Fixed Code**: Corrected implementation using [LIBRARY] 7. **References**: NIST SP 800-175B, RFC references Provide an overall cryptographic maturity assessment and migration roadmap.
Free to copy and use. Compatible with Claude 4 Opus, GPT-5, Gemini 2.5 Pro.
Paste your cryptographic code or describe the system. Specify the crypto library in use. Review each finding and prioritize fixes for Critical/High severity issues. Use the migration roadmap for long-term improvements.
Initial release
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