Guides tagged “Security”

Reviewed developer guides with worked examples, limitations and links to the standards or documentation behind the tools.

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Sep 3, 2026 · Maintained by WilliamCHMOD 755 vs 644 vs 600: Permissions Explained with ExamplesDecode common Unix permission modes, see why files and directories need different execute bits, and avoid insecure recursive chmod fixes.Sep 3, 2026 · Maintained by WilliamJWT Decoding vs Verification: The Difference That Prevents Security BugsDecoding a JWT only reveals its claims. Verification proves whether the token can be trusted. See the distinction with safe examples and production checks.Sep 3, 2026 · Maintained by WilliamJWT Claims Explained: exp, iat, nbf, iss, aud and subA practical reference for common JWT registered claims, with clock-skew notes, validation rules and examples that separate inspection from trust.Sep 3, 2026 · Maintained by WilliamCORS Preflight Requests Explained with Real OPTIONS ExamplesUnderstand when browsers send an OPTIONS preflight, what headers they ask for, and how a server should answer without weakening cross-origin policy.Sep 3, 2026 · Maintained by WilliamWhy Access-Control-Allow-Origin: * Fails with CredentialsWhy wildcard origins and credentialed browser requests do not mix, what to return instead, and how to avoid reflecting untrusted origins.Sep 3, 2026 · Maintained by WilliamHTTP Security Headers: What Each Header Actually DoesA practical map of HSTS, CSP, X-Content-Type-Options, Referrer-Policy, Permissions-Policy and legacy frame protections, with deployment caveats.Sep 3, 2026 · Maintained by WilliamContent-Security-Policy Explained: Start with a Safe BaselineBuild a CSP from default-src, script-src, object-src, base-uri and frame-ancestors, then tighten it with reporting instead of copying a header blindly.