0.2.0

[0.2.0] - 2026-04-11

• Argon2id password hashing - Replaced bcrypt (server-side) and PBKDF2 (client-side) with Argon2id for both. Argon2id is memory-hard and resistant to GPU/ASIC brute-force attacks.
• AES-256-GCM encryption - Replaced CryptoJS AES-CBC with Web Crypto API AES-256-GCM (authenticated encryption). Eliminates padding oracle attack surface.
• Rate limiting - Added Flask-Limiter (10 requests/minute per IP) on the secret retrieval endpoint to prevent brute-force attacks.
• Per-secret lockout - Secrets lock after 10 failed password attempts.
• One-time secret race condition fix - Atomic claim pattern prevents concurrent requests from both retrieving a one-time secret. Uses file rename (local), dict lock (memory), head+delete (S3), and generation-match delete (GCS).
• Security headers - Added Content-Security-Policy, X-Frame-Options (DENY), X-Content-Type-Options (nosniff), Referrer-Policy (no-referrer), and Permissions-Policy via nginx.
• Strict CSP - No 'unsafe-inline' in script-src. All inline scripts and event handlers moved to external JS files. All third-party scripts consolidated to a single CDN (jsdelivr). Inline styles replaced with the hidden HTML attribute where possible.
• Input validation - All POST endpoints validate JSON fields, types, and allowed values. Returns 400 on invalid input. Unsupported version values are strictly rejected (400).
• ProxyFix hardened - Changed from x_host=1 to x_for=1, x_proto=1, x_host=0 to prevent host header injection.
• Nginx body size - Reduced client_max_body_size from 1G to 2m to match application limits.
• Config key warning - Startup warning if secret_key appears to be a default or is too short.
• PBKDF2 iteration count - Increased client-side PBKDF2-SHA256 key derivation from 210,000 to 600,000 iterations per OWASP recommendations.
• Modulo bias fix - Random password generation now uses rejection sampling to eliminate bias.
• Password visibility toggle - Password fields default to hidden (type="password") with eye icon toggle on both create and retrieve pages.
• HSTS enabled by default in nginx config (2-year max-age, includeSubDomains, preload).
• Flask debug mode decoupled from LOG_LEVEL to prevent accidental Werkzeug debugger exposure in containers.