Core Code
Core Code Modern Dev Handbook
APPLICATION-SECURITY Contents
Security Foundations for Production Apps
Threat Modeling (Practical, Repeatable) OWASP Top 10 (Operator Lens) Defense in Depth (Layered Controls That Hold) Security Baselines and Checklists (What “Good” Looks Like) Secrets in Apps (Storage, Injection, Rotation) Logging Sensitive Data (Pitfalls and Redaction) Rate Limiting Patterns (Abuse and Resilience) Abuse Prevention (Bots, Fraud, Enumeration) HTTPS & TLS Realities (HSTS, Termination, Cert Ops) Secure Headers Baseline (Production Defaults)
Identity, Authentication, and Sessions
Sessions vs JWT (Production Tradeoffs) JWT Attack Patterns and Validation Pitfalls Password Hashing Ops (bcrypt/argon2 Parameters) OAuth2 Flows in Practice (Auth Code + PKCE) OIDC Internals (Discovery, JWKS, Claims) Token Revocation Strategies (What Actually Works) Refresh Token Abuse and Rotation Defenses API Key Management (Issuance, Rotation, Scoping) mTLS Basics (Service-to-Service Identity) Identity Boundary Design (Trust Zones)
Web Attacks and Practical Defenses
XSS in Production (Exploit Paths and CSP Hardening) CSRF (SameSite Reality vs Token Defenses) SSRF (Cloud Metadata Abuse and Egress Controls) Clickjacking (Frame Controls and UI Redress) SQL Injection (Production Defense Patterns) CORS Misconfigurations (Real-World Impact) CSP Practical Recipes (Deployable Policies) Secure Cookie Patterns (HttpOnly, Secure, SameSite) Request Validation Patterns (What to Validate Where) File Upload Hardening (Content Sniffing, AV, Storage)
Secure Delivery, Hardening, and Incident Response
Secure SDLC (Gates That Don’t Kill Delivery) Dependency Risks (Vulns, Updates, Policies) App Supply Chain (Lockfiles, Pinning, Review) Configuration Hardening (Safe Defaults Checklist) Security Monitoring Signals (Auth, Data, Network) Security Alert Design (Noise, Triage, Escalation) WAF Realities (What It Stops and What It Doesn’t) Credential Leak Runbook (Keys, Tokens, Passwords) Compromised Token Runbook (JWT/OAuth Sessions) Security Incident Response (Contain, Eradicate, Recover)

API Key Management (Issuance, Rotation, Scoping)

API key management that survives production: scoping, rotation, storage, leak detection, and an emergency revoke runbook.
On this page

API Key Rules

  • Never ship keys to browsers or mobile apps as a secret.
  • Scope keys (per service, per environment, per permission set).
  • Prefer short-lived tokens or mTLS for internal services.

Scoping Model

  • Read-only vs write separated.
  • Per-tenant keys where needed.
  • Explicit allowlist of endpoints/actions per key.

Rotation Strategy

Rotate key:
1) Create new key (keep old valid)
2) Deploy consumers with new key
3) Verify success rate and error rate
4) Revoke old key
5) Search logs for old key id usage

Leak Detection

  • Secret scanning in CI + repository hooks.
  • Alert on unusual key usage (new IP ranges, spike in calls, new user agent).

Emergency Revoke Runbook

  • Revoke key immediately.
  • Identify blast radius (which services/tenants used it).
  • Rotate dependent secrets if the key granted access to them.
  • Postmortem: add tests/controls to prevent repeat.
mTLS Basics (Service-to-Service Identity) →