Secure Coding Practices Across Languages Security works best when it travels across languages, not when it stops at a single stack. The same ideas apply whether you code in C, Java, Python, or JavaScript. By applying consistent habits, you reduce vulnerabilities and simplify audits.
Common principles across languages Defense in depth: combine validation, encoding, authentication, and logging. Fail closed and limit data exposure when errors happen. Use well-known libraries and avoid rolling your own crypto or crypto-like logic. Validation and encoding Validate input for type, length, range, and business rules. Encode output before rendering to prevent injection in every channel (web, logs, emails). Use prepared statements or parameterized queries to avoid SQL injection. Authentication and authorization Prefer established frameworks and tokens rather than custom auth code. Enforce least privilege and verify permissions at each boundary. Error handling and logging Do not leak internal traces to users; show friendly errors. Use structured logs and rotate them to avoid leaking secrets. Dependency management and secure configuration Lock dependencies, scan for known flaws, and update regularly. Store secrets in a vault or environment managers; never hard-code. Cross-language boundaries Define stable data formats (JSON, YAML) and validate them at the boundary. Apply the same encoding rules for all clients and services. Quick takeaways Build with security defaults and test early. Review code and dependencies with security in mind. Monitor and respond to incidents promptly. Key Takeaways Apply defense in depth and secure defaults across all languages. Use validated inputs, encoded outputs, and vetted libraries. Maintain secrets securely, scan dependencies, and practice threat modeling.